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+publicationDate,title,abstract,id
+2012-12-14,Saturation of magnetic films with spin-polarized current in presence of magnetic field,"Influence of perpendicular magnetic field on the process of transversal
+saturation of ferromagnetic films with spin-polarized current is studied
+theoretically. It is shown that the saturation current $J_s$ is decreased
+(increased) in case of codirected (oppositely directed) magnetic field and
+current. There exists a critical current $J_c>J_s$ which provides ""rigid""
+saturation -- the saturated state is stable with respect to the transverse
+magnetic field of any amplitude and direction. Influence of the magnetic field
+on the vortex-antivortex crystals, which appear in pre-saturated regime, is
+studied numerically. All analytical results are verified using micromagnetic
+simulations.",1212.3578v1
+2009-04-20,Saturation of Magnetorotational Instability through Magnetic Field Generation,"The saturation mechanism of Magneto-Rotational Instability (MRI) is examined
+through analytical quasilinear theory and through nonlinear computation of a
+single mode in a rotating disk. We find that large-scale magnetic field is
+generated through the alpha effect (the correlated product of velocity and
+magnetic field fluctuations) and causes the MRI mode to saturate. If the
+large-scale plasma flow is allowed to evolve, the mode can also saturate
+through its flow relaxation. In astrophysical plasmas, for which the flow
+cannot relax because of gravitational constraints, the mode saturates through
+field generation only.",0904.2941v1
+2000-10-19,Magnetic Field Saturation in the Riga Dynamo Experiment,"After the dynamo experiment in November 1999 had shown magnetic field
+self-excitation in a spiraling liquid metal flow, in a second series of
+experiments emphasis was placed on the magnetic field saturation regime as the
+next principal step in the dynamo process. The dependence of the strength of
+the magnetic field on the rotation rate is studied. Various features of the
+saturated magnetic field are outlined and possible saturation mechanisms are
+discussed.",0010047v1
+2013-12-03,Dependence of the cross polar cap potential saturation on the type of solar wind streams,"We compare of the cross polar cap potential (CPCP) saturation during magnetic
+storms induced by various types of the solar wind drivers. By using the model
+of Siscoe-Hill
+\citep{Hilletal1976,Siscoeetal2002a,Siscoeetal2002b,Siscoeetal2004,Siscoe2011}
+we evaluate criteria of the CPCP saturation during the main phases of 257
+magnetic storms ($Dst_{min} \le -50$ nT) induced by the following types of the
+solar wind streams: magnetic clouds (MC), Ejecta, the compress region Sheath
+before MC ($Sh_{MC}$) and before Ejecta ($Sh_{E}$), corotating interaction
+regions (CIR) and indeterminate type (IND). Our analysis shows that occurrence
+rate of the CPCP saturation is higher for storms induced by ICME ($13.2%$) than
+for storms driven by CIR ($3.5%$) or by IND ($3.5%$).The CPCP saturation was
+obtained more often for storms initiated by MC ($25%$) than by Ejecta ($2.9%$);
+it was obtained for $8.6%$ of magnetic storms induced by sum of MC and Ejecta,
+and for $21.5%$ magnetic storms induced by Sheath before them (sum of $Sh_{MC}$
+and $Sh_{E}$). These results allow us to conclude that occurrence rate of the
+CPCP saturation at the main phase of magnetic storms depends on the type of the
+solar wind stream.",1312.0778v1
+2018-12-05,Quantum mechanics basis of quality control in hard metals,"Non-destructive and reliable quality control methods are a key aspect to
+designing, developing and manufacturing new materials for industrial
+applications and new technologies. The measurement of the magnetic saturation
+is one of such methods and it is conventionally employed in the cemented
+carbides industry. We present a general quantum mechanics based relation
+between the magnetic saturation and the components of the binder phase of
+cemented carbides, which can be directly employed as a quality control. To
+illustrate our results, we calculate the magnetic saturation of a binder phase,
+85Ni15Fe binary alloy, using ab-initio methods and compare the theoretical
+predictions to the magnetic saturation measurements. We also analyse interface
+and segregation effects on the magnetic saturation by studying the electronic
+structure of the binder phase. The excellent agreement between calculations and
+measurements demonstrates the applicability of our method to any binder phase.
+Since the magnetic saturation is employed to ensure the quality of cemented
+carbides, the present method allows us to explore new materials for alternative
+binder phases efficiently",1812.01960v1
+2005-01-20,Saturation mechanism of the Weibel instability in weakly magnetized plasmas,"The saturation mechanism of the Weibel instability is investigated
+theoretically by considering the evolution of currents in numerous cylindrical
+beams that are generated in the initial stage of the instability. Based on a
+physical model of the beams, it is shown that the magnetic field strength
+attains a maximum value when the currents in the beams evolve into the Alfven
+current and that there exist two saturation regimes. The theoretical prediction
+of the magnetic field strength at saturation is in good agreement with the
+results of two-dimensional particle-in-cell simulations for a wide range of
+initial anisotropy.",0501110v2
+2023-05-21,An Alternative Derivation of the Landau-Lifshitz-Gilbert Equation for Saturated Ferromagnets,"The Landau-Lifshitz-Gilbert equation for rigid and saturated ferromagnets is
+derived using a two-continuum model constructed by H.F. Tiersten for elastic
+and saturated ferromagnets. The relevant basic laws of physics are applied
+systematically to the two continua or their combination. The exchange
+interaction is introduced into the model through surface distributed magnetic
+couples. This leads to a continuum theory with magnetization gradients in the
+stored energy density. The saturation condition of the magnetization functions
+as constraints on the energy density and has implications in the constitutive
+relations.",2305.18232v1
+2012-07-24,Sensorless position estimation of Permanent-Magnet Synchronous Motors using a saturation model,"Sensorless control of Permanent-Magnet Synchronous Motors (PMSM) at low
+velocity remains a challenging task. A now well-established method consists in
+injecting a high-frequency signal and use the rotor saliency, both geometric
+and magnetic-saturation induced. This paper proposes a clear and original
+analysis based on second-order averaging of how to recover the position
+information from signal injection; this analysis blends well with a general
+model of magnetic saturation. It also proposes a simple parametric model of the
+saturated PMSM, based on an energy function which simply encompasses saturation
+and cross-saturation effects. Experimental results on a surface-mounted PMSM
+and an interior magnet PMSM illustrate the relevance of the approach.",1207.5743v1
+2020-09-08,Automatic Detection and Correction Algorithms for Magnetic Saturation in the SMFT/HSOS longitudinal Magnetograms,"longitudinal magnetic field often suffers the saturation effect in strong
+magnetic field region when the measurement performs in a single-wavelength
+point and linear calibration is adopted. In this study, we develop a method
+that can judge the threshold of saturation in Stokes $V/I$ observed by the
+Solar Magnetic Field Telescope (SMFT) and correct for it automatically. The
+procedure is that first perform the second-order polynomial fit to the Stokes
+$V/I$ \textit{vs} $I/I_{m}$ ($I_{m}$ is the maximum value of Stokes $I$) curve
+to estimate the threshold of saturation, then reconstruct Stokes $V/I$ in
+strong field region to correct for saturation. The algorithm is proved to be
+effective by comparing with the magnetograms obtained by the Helioseismic and
+Magnetic Imager (HMI). The accurate rate of detection and correction for
+saturation is $\sim$99.4\% and $\sim$88\% respectively among 175 active
+regions. The advantages and disadvantages of the algorithm are discussed.",2009.03597v1
+2016-03-24,Saturation properties of nuclear matter in the presence of strong magnetic field,"Different saturation properties of cold symmetric nuclear matter in the
+strong magnetic field have been considered. We have seen that for magnetic
+fields about $B> 3 \times 10 ^ {17}\ G$, {for both cases with and without
+nucleon anomalous magnetic moments}, the saturation density and saturation
+energy grow by increasing the magnetic field. It is indicated that the magnetic
+susceptibility of symmetric nuclear matter becomes negative showing the
+diamagnetic response especially at $B< 3 \times 10 ^ {17}\ G$. We have found
+that for the nuclear matter, the magnitude of orbital magnetization reaches the
+higher values comparing to the spin magnetization. Our results for the
+incompressibility show that at high enough magnetic fields, i.e. $B> 3 \times
+10 ^ {17}\ G$, {the softening of equation of state caused by Landau
+quantization is overwhelmed by stiffening due to the magnetization of nuclear
+matter.} We have shown that the effects of strong magnetic field on nuclear
+matter may affect the constraints on the equation of state of symmetric nuclear
+matter obtained applying the experimental observable.",1603.07561v1
+2013-04-30,Saturated symmetric nuclear matter in strong magnetic fields,"Strongly magnetized symmetric nuclear matter is investigated within the
+context of effective baryon-meson exchange models. The magnetic field is
+coupled to the charge as well as the dipole moment of the baryons by including
+the appropriate terms in the Lagrangian density. The saturation density of
+magnetized, symmetric nuclear matter was calculated for magnetic fields of the
+order of 10^17 gauss. For the calculated range of saturation densities the
+binding energy, symmetry energy coefficient and compressibility of nuclear
+matter were also calculated. It is found that with an increasing magnetic field
+the saturation density increases, while the system becomes less bound.
+Furthermore, the depopulation of proton Landau levels leaves a distinct
+fluctuating imprint on the symmetry energy coefficient and compressibility. The
+calculations were also performed for increased values of the baryon magnetic
+dipole moment. By increasing the dipole moment strength the saturation density
+is found to decrease, but the system becomes more tightly bound while the
+fluctuations in the symmetry energy coefficient and compressibility persist.",1304.7951v2
+2008-09-10,How do dynamos saturate?,"In order better to understand how dynamo systems saturate, we study the
+kinematic dynamo properties of velocity fields that arise from nonlinearly
+saturated dynamos. The technique is implemented by solving concurrently, in
+addition to the momentum equation, two induction equations, one for the actual
+magnetic field, and one for an independent passive field. We apply this
+technique to two illustrative examples: convectively driven turbulence, and
+turbulence represented by a shell model. In all cases we find that the velocity
+remains an efficient kinematic dynamo even after nonlinear saturation occurs.
+We discuss the implications to the process of dynamo saturation.",0809.1801v2
+2011-03-15,Estimation of Saturation of Permanent-Magnet Synchronous Motors Through an Energy-Based Model,"We propose a parametric model of the saturated Permanent-Magnet Synchronous
+Motor (PMSM) together with an estimation method of the magnetic parameters. The
+model is based on an energy function which simply encompasses the saturation
+effects. Injection of fast-varying pulsating voltages and measurements of the
+resulting current ripples then permit to identify the magnetic parameters by
+linear least squares. Experimental results on a surface-mounted PMSM and an
+interoir magnet PMSM illustrate the relevance of the approach.",1103.2923v1
+2012-06-13,Saturation Magnetization of Inorganic/polymer Nanocomposites Higher than That of Their Inorganic Magnetic Component,"Herein, some magnetic nanoparticles (MNP)/clay/polymer nanocomposites have
+been prepared, whose saturation magnetization is higher than that of pure oleic
+acid coated MNP component. The existence of unique 'nano-network' structure and
+tight three-phase nano-interface in the nanocomposites contribute to the
+surprising saturation magnetization.",1206.2805v1
+2007-02-13,Inverse cascades and alpha-effect at low magnetic Prandtl number,"Dynamo action in a fully helical Beltrami (ABC) flow is studied using both
+direct numerical simulations and subgrid modeling. Sufficient scale separation
+is given in order to allow for large-scale magnetic energy build-up. Growth of
+magnetic energy obtains down to a magnetic Prandtl number PM=RM/RV close to
+0.005, where RV and RM are the kinetic and magnetic Reynolds numbers. The
+critical magnetic Reynolds number for dynamo action RMc seems to saturate at
+values close to 20. Detailed studies of the dependence of the amplitude of the
+saturated magnetic energy with PM are presented. In order to decrease PM,
+numerical experiments are conducted with either RV or RM kept constant. In the
+former case, the ratio of magnetic to kinetic energy saturates to a value
+slightly below unity as PM decreases. Examination of energy spectra and
+structures in real space both reveal that quenching of the velocity by the
+large-scale magnetic field takes place, with an inverse cascade of magnetic
+helicity and a force-free field at large scale in the saturated regime.",0702109v1
+2015-04-23,The Tayler instability at low magnetic Prandtl numbers: between chiral symmetry breaking and helicity oscillations,"The Tayler instability is a kink-type, current driven instability that plays
+an important role in plasma physics but might also be relevant in liquid metal
+applications with high electrical currents. In the framework of the
+Tayler-Spruit dynamo model of stellar magnetic field generation, the question
+of spontaneous helical (chiral) symmetry breaking during the saturation of the
+Tayler instability has received considerable interest. Focusing on fluids with
+low magnetic Prandtl numbers, for which the quasistatic approximation can be
+applied, we utilize an integro-differential equation approach in order to
+investigate the saturation mechanism of the Tayler instability. Both the
+exponential growth phase and the saturated phase are analyzed in terms of the
+action of the alpha and beta effects of mean-field magnetohydrodynamics. In the
+exponential growth phase we always find a spontaneous chiral symmetry breaking
+which, however, disappears in the saturated phase. For higher degrees of
+supercriticality, we observe helicity oscillations in the saturated regime. For
+Lundquist numbers in the order of one we also obtain chiral symmetry breaking
+of the saturated magnetic field.",1504.06120v1
+2022-08-08,Study of Asymmetric Magnetization Reversal and Exchange Bias in FePt(L10)/FeCo/CoO/FeCo Magnetic Multilayer,"The effect of the saturation field on the magnetization reversal of
+FePt(L10)/FeCo/CoO/FeCo multilayer (ML) has been investigated to understand the
+origin of asymmetric magnetization reversal and its correlation with exchange
+bias (EB). In the ML structure, the bottom FeCo layer is coupled to the hard
+FePt(L10) layer, and the top FeCo layer is comparatively free due to the
+relatively more distance from it. The ML has been deposited under UHV
+conditions and characterized at each stage of growth using magneto-optical Kerr
+effect and x-ray reflectivity techniques. Magnetization reversal is further
+studied through domain imaging using the Kerr microscopy technique. The
+experimental findings reveal that ML exhibits asymmetrical magnetization
+reversal for a certain range of azimuthal angles for both 1.5kOe and 50kOe
+saturation fields; however, this angular range of asymmetry decreases with the
+increase in the saturation field. Furthermore, EB was absent at the low
+saturation field, whereas, EB, in addition to asymmetry, is observed at the
+large saturation field. The origin of asymmetry is attributed to
+non-collinearity between magnetic anisotropy axes of both FeCo layers. It
+results from the proximity effect through short-range Heisenberg exchange
+interaction via the CoO barrier layer. On the other hand, EB arises due to
+unidirectional anisotropy induced in the FePt layer due to the high saturation
+field. It is further proposed that asymmetry would disappear when
+unidirectional anisotropy is strong enough to align both the FeCo layers in the
+saturation direction leading to loss of the non-collinearity between them.",2208.04038v1
+2020-02-17,Enhancement of magnetization plateaus in low dimensional spin systems,"We study the low-energy properties and, in particular, the magnetization
+process of a spin-1/2 Heisenberg $J_1-J_2$ sawtooth and frustrated chain (also
+known as zig-zag ladder) with a spatially anisotropic $g$-factor. We treat the
+problem both analytically and numerically while keeping the $J_2/J_1$ ratio
+generic. Numerically, we use complete and Lanczos diagonalization as well as
+the infinite time-evolving block decimation (iTEBD) method. Analytically we
+employ (non-)Abelian bosonization. Additionally for the sawtooth chain, we
+provide an analytical description in terms of flat bands and localized magnons.
+By considering a specific pattern for the $g$-factor anisotropy for both
+models, we show that a small anisotropy significantly enhances a magnetization
+plateau at half saturation. For the magnetization of the frustrated chain, we
+show the destruction of the $1/3$ of the full saturation plateau in favor of
+the creation of a plateau at half-saturation. For large anisotropies, the
+existence of an additional plateau at zero magnetization is possible. Here and
+at higher magnetic fields, the system is locked in the half-saturation plateau,
+never reaching full saturation.",2002.07190v1
+2023-05-17,Role of magnetic pressure forces in fluctuation dynamo saturation,"Using magnetohydrodynamic simulations of fluctuation dynamos in turbulent
+flows with rms Mach numbers $\mathcal{M}_{\rm rms} = 0.2, 1.1$ and $3$, we show
+that magnetic pressure forces play a crucial role in dynamo saturation in
+supersonic flows. First, as expected when pressure forces oppose compression,
+an increase in anticorrelation between density and magnetic field strengths
+obtains even in subsonic flows with the anti-correlation arising from the
+intense but rarer magnetic structures. In supersonic flows, due to stronger
+compressive motions density and magnetic field strength continue to maintain a
+positive correlation. However, the degree of positive correlation decreases as
+the dynamo saturates. Secondly, we find that the unit vectors of $\nabla\rho$
+and $\nabla B^{2}$ are preferentially antiparallel to each other in subsonic
+flows. This is indicative of magnetic pressure opposing compression. This
+antiparallel alignment persists in transonic and supersonic flows at dynamo
+saturation. However, compressive motions also lead to the emergence of a
+parallel alignment in these flows. Finally, we consider the work done against
+the components of the Lorentz force and the different sources of magnetic
+energy growth and dissipation. We show that while in subsonic flows,
+suppression of field line stretching is dominant in saturating the dynamo, the
+picture is different in supersonic flows. Both field line stretching and
+compression initially amplifies the field. However, growing magnetic pressure
+opposes further compression of magnetic flux which tends to reduce the
+compressive motions. Simultaneously, field line stretching also reduces. But,
+suppression of compressive amplification dominates the saturation of the
+dynamo.",2305.09969v2
+2018-10-12,Gyrokinetic theory of the nonlinear saturation of toroidal Alfven eigenmode,"Nonlinear saturation of toroidal Alfven eigenmode (TAE) via ion induced
+scatterings is investigated in the short-wavelength gyrokinetic regime. It is
+found that the nonlinear evolution depends on the thermal ion \b{eta} value.
+Here, \b{eta} is the plasma thermal to magnetic pressure ratio. Both the
+saturation levels and associated energetic-particle transport coefficients are
+derived and estimated correspondingly.",1810.05295v1
+2001-01-06,Evidence for Adiabatic Magnetization of cold Dy_N Clusters,"Magnetic properties of Dy_N clusters in a molecular beam generated with a
+liquid helium cooled nozzle are investigated by Stern-Gerlach experiments. The
+cluster magnetizations \mu_z are measured as a function of magnetic field (B =
+0 - 1.6T) and cluster size (16 < N < 56). The most important observation is the
+saturation of the magnetization \mu_z(B) at large field strengths. The
+magnetization approaches saturation following the power law |\mu_z-\mu_0|
+proportional to 1/\sqrt{B}, where \mu_0 denotes the magnetic moment. This gives
+evidence for adiabatic magnetization.",0101075v1
+2014-01-28,Magnetic Field Amplification and Saturation in Turbulence Behind a Relativistic Shock,"We have investigated via two-dimensional relativistic MHD simulations the
+long-term evolution of turbulence created by a relativistic shock propagating
+through an inhomogeneous medium. In the postshock region, magnetic field is
+strongly amplified by turbulent motions triggered by preshock density
+inhomogeneities. Using a long-simulation box we have followed the
+magnetic-field amplification until it is fully developed and saturated. The
+turbulent velocity is sub-relativistic even for a strong shock. Magnetic-field
+amplification is controled by the turbulent motion and saturation occurs when
+the magnetic energy is comparable to the turbulent kinetic energy.
+Magnetic-field amplification and saturation depend on the initial strength and
+direction of the magnetic field in the preshock medium, and on the shock
+strength. If the initial magnetic field is perpendicular to the shock normal,
+the magnetic field is first compressed at the shock and then can be amplified
+by turbulent motion in the postshock region. Saturation occurs when the
+magnetic energy becomes comparable to the turbulent kinetic energy in the
+postshock region. If the initial magnetic field in the preshock medium is
+strong, the postshock region becomes turbulent but significant field
+amplification does not occur. If the magnetic energy after shock compression is
+larger than the turbulent kinetic energy in the postshock region, significant
+field amplification does not occur. We discuss possible applications of our
+results to gamma-ray bursts and active galactic nuclei.",1401.7080v1
+2009-09-24,Discovery of localized states of Fe 3d electrons in Fe16N2 and Fe8N films: an evidence of the existence of giant saturation magnetization,"The mystery of giant saturation magnetization of Fe16N2 has remained for 37
+years. In this letter, X-ray absorption spectroscopy (XAS) and magnetic
+circular dichroism (XMCD) are used to study the electron states of Fe atoms in
+Fe16N2 and Fe8N films. Localized Fe 3d electron states, which are not expected
+from current theories (models), are observed. The XMCD spectra and elemental
+hysteresis loops reveal the polarization of N atoms and the hybridization of N
+and Fe atoms. This discovery points to the origin of giant saturation
+magnetization in Fe16N2.",0909.4478v1
+2012-03-26,Signal injection and averaging for position estimation of Permanent-Magnet Synchronous Motors,"Sensorless control of Permanent-Magnet Synchronous Motors at low velocity
+remains a challenging task. A now well-established method consists in injecting
+a high-frequency signal and use the rotor saliency, both geometric and
+magnetic-saturation induced. This paper proposes a clear and original analysis
+based on second-order averaging of how to recover the position information from
+signal injection; this analysis blends well with a general model of magnetic
+saturation. It also experimentally demonstrates the relevance for position
+estimation of a simple parametric saturation model recently introduced by the
+authors.",1203.5672v1
+2020-03-18,On the saturation mechanism of the fluctuation dynamo at ${\text{Pr}_\mathrm{M}} \ge 1$,"The presence of magnetic fields in many astrophysical objects is due to
+dynamo action, whereby a part of the kinetic energy is converted into magnetic
+energy. A turbulent dynamo that produces magnetic field structures on the same
+scale as the turbulent flow is known as the fluctuation dynamo. We use
+numerical simulations to explore the nonlinear, statistically steady state of
+the fluctuation dynamo in driven turbulence. We demonstrate that as the
+magnetic field growth saturates, its amplification and diffusion are both
+affected by the back-reaction of the Lorentz force upon the flow. The
+amplification of the magnetic field is reduced due to stronger alignment
+between the velocity field, magnetic field, and electric current density.
+Furthermore, we confirm that the amplification decreases due to a weaker
+stretching of the magnetic field lines. The enhancement in diffusion relative
+to the field line stretching is quantified by a decrease in the computed local
+value of the magnetic Reynolds number. Using the Minkowski functionals, we
+quantify the shape of the magnetic structures produced by the dynamo as
+magnetic filaments and ribbons in both kinematic and saturated dynamos and
+derive the scalings of the typical length, width, and thickness of the magnetic
+structures with the magnetic Reynolds number. We show that all three of these
+magnetic length scales increase as the dynamo saturates. The magnetic
+intermittency, strong in the kinematic dynamo (where the magnetic field
+strength grows exponentially) persists in the statistically steady state, but
+intense magnetic filaments and ribbons are more volume-filling.",2003.07997v1
+2015-03-27,Dynamo Saturation in Rapidly Rotating Solar-Type Stars,"The magnetic activity of solar-type stars generally increases with stellar
+rotation rate. The increase, however, saturates for fast rotation. The
+Babcock-Leighton mechanism of stellar dynamos saturates as well when the mean
+tilt-angle of active regions approaches ninety degrees. Saturation of magnetic
+activity may be a consequence of this property of the Babcock-Leighton
+mechanism. Stellar dynamo models with a tilt-angle proportional to the rotation
+rate are constructed to probe this idea. Two versions of the model - treating
+the tilt-angles globally and using Joy's law for its latitude dependence - are
+considered. Both models show a saturation of dynamo-generated magnetic flux at
+high rotation rates. The model with latitude-dependent tilt-angles also shows a
+change in dynamo regime in the saturation region. The new regime combines a
+cyclic dynamo at low latitudes with an (almost) steady polar dynamo.",1503.07956v3
+2015-03-16,Dynamics of Current and Field Driven Domain Wall Motion under the Influence of Transverse Magnetic Field,"The dynamics of transverse Neel domain wall in a ferromagnetic nanostrip in
+the presence of driving field, current and transverse magnetic field is
+investigated by the Landau-Lifshitz-Gilbert(LLG) equation with the adiabatic
+and non-adiabatic spin-transfer torques both analytically and numerically. The
+analytical expressions for the velocity, width, excitation angle and
+displacement for the domain wall are obtained by using small angle
+approximation along with Walkers trial function. The results show that the
+initial velocity of the domain wall can be controlled by the adiabatic
+spin-transfer torque and the saturated velocity can be controlled by the
+non-adiabatic spin-transfer torque and driving field. The large increase in the
+saturated velocity of the domain wall driven by current and field due to the
+transverse magnetic field is identified through the presence of driving field.
+There is no impact in the saturated velocity of the domain wall driven by
+current from the transverse magnetic field. For the domain wall driven by the
+current in the presence of the transverse magnetic field, the saturated
+velocity remains constant. The transverse magnetic field along with current and
+driving field is more advantageous that the transverse magnetic field along
+with current for increasing the saturated velocity of the domain wall. The
+numerical results showed that the saturated velocity is increased by the
+transverse magnetic field with the irrespective of the directions of the
+driving field and current further it is higher and lower when the directions of
+driving field and current are antiparallel and parallel respectively. The
+obtained analytical solutions are closely coincided with the computed numerical
+results.",1503.04560v2
+2015-06-11,Dependence of the saturation level of magnetorotational instability on gas pressure and magnetic Prandtl number,"A large set of numerical simulations of magnetohydrodynamic (MHD) turbulence
+induced by the magnetorotational instability (MRI) is presented. Revisiting the
+previous survey conducted by Sano et al. (2004), we investigate the gas
+pressure dependence of the saturation level. In ideal MHD simulations, the gas
+pressure dependence is found to be very sensitive to the choice of a numerical
+scheme. This is because the numerical magnetic Prandtl number varies according
+to the scheme as well as the pressure, which considerably affects the results.
+The saturation level is more sensitive to the numerical magnetic Prandtl number
+than the pressure. In MHD simulations with explicit viscosity and resistivity,
+the saturation level increases with the physical magnetic Prandtl number, and
+it is almost independent of the gas pressure when the magnetic Prandtl number
+is constant. This is indicative of the incompressible turbulence saturated by
+the secondary tearing instability.",1506.03524v1
+2016-12-12,Electron Weibel Instability in Relativistic Counter-Streaming Plasmas with Flow-Aligned External Magnetic Fields,"The Weibel instability driven by two symmetric counter-streaming relativistic
+electron plasmas, also referred to as current-filamentation instability, is
+studied in a constant and uniform external magnetic field aligned with the
+plasma flows. Both the linear and non linear stages of the instability are
+investigated using analytical modeling and Particle-In-Cell (PIC) simulations.
+While previous studies have already described the stabilizing effect of the
+magnetic field, we show here that the saturation stage is only weakly affected.
+The different mechanisms responsible for the saturation are discussed in detail
+in the relativistic cold fluid framework considering a single unstable mode.
+The application of an external field leads to a slighlt increase of the
+saturation level for large wavelengths, while it does not affect the small
+wavelengths. Multi-mode and temperature effects are then investigated. While at
+large temperature the saturation level is independent of the external magnetic
+field, at small but finite temperature the competition between different modes
+in the presence of an external magnetic field leads to a saturation level lower
+with respect to the unmagnetized case.",1612.03934v1
+1993-12-21,Magnetic Properties of the Spin-1/2 Ferromagnetic-Ferromagnetic-Antiferromagnetic Trimerized Heisenberg Chain:,"The magnetic properties of the ferromagnetic-ferromagnetic-antiferromagnetic
+trimerized spin-1/2 Heisenberg chain are studied theoretically. The high
+temperature susceptibilty and the ground state saturation magnetic field are
+calculated and the exchange energies of the trimer compound 3CuCl${}_2\cdot$2dx
+are determined. The magnetization curve is obtained by numerical
+diagonalization of finite size systems. The result explains the low temperature
+magnetization data for 3CuCl${}_2\cdot$2dx with the exchange energies obtained
+as above. It is predicted that the magnetization curve has a plateau at 1/3 of
+the saturation magnetization if the ferromagnetic exchange energy is comparable
+to or smaller than the antiferromagnetic exchange energy.",9312084v1
+2004-11-10,Magnetotransport in inhomogeneous magnetic fields,"Quantum transport in inhomogeneous magnetic fields is investigated
+numerically in two-dimensional systems using the equation of motion method. In
+particular, the diffusion of electrons in random magnetic fields in the
+presence of additional weak uniform magnetic fields is examined. It is found
+that the conductivity is strongly suppressed by the additional uniform magnetic
+field and saturates when the uniform magnetic field becomes on the order of the
+fluctuation of the random magnetic field. The value of the conductivity at this
+saturation is found to be insensitive to the magnitude of the fluctuation of
+the random field. The effect of random potential on the magnetoconductance is
+also discussed.",0411248v1
+2017-05-22,Nonlinear saturation of the Weibel instability,"The growth and saturation of magnetic fields due to the Weibel instability
+(WI) have important implications for laboratory and astrophysical plasmas, and
+this has drawn significant interest recently. Since the WI can generate a large
+magnetic field from no initial field, the maximum magnitudes achieved can have
+significant consequences for a number of applications. Hence, an understanding
+of the detailed dynamics driving the nonlinear saturation of the WI is
+important. This work considers the nonlinear saturation of the WI when
+counter-streaming populations of initially unmagnetized electrons are perturbed
+by a magnetic field oriented perpendicular to the direction of streaming.
+Previous works have found magnetic trapping to be important and connected
+electron skin depth spatial scales to the nonlinear saturation of the WI. 2
+Results presented in this work are consistent with these findings for a
+high-temperature case. However, using a high-order continuum kinetic simulation
+tool, this work demonstrates that, when the electron populations are colder, a
+significant electrostatic potential develops that works with the magnetic field
+to create potential wells. The electrostatic field develops due to transverse
+flows induced by the WI, and in some cases is strengthened by a secondary
+instability. This field plays a key role in saturation of the WI for colder
+populations. The role of the electrostatic potential in Weibel instability
+saturation has not been studied in detail previously.",1705.07930v4
+2013-02-15,A novel magnetic phase prior to a saturation moment in frustrated spinel oxides in ultra-high magnetic fields,"We have investigated the magnetic-field induced phases of a typical
+three-dimensional frustrated magnet, CdCr$_2$O$_4$, in magnetic fields of up to
+120 T that is generated by the single-turn coil techniques. We focused on
+magnetic phase transitions in proximity of a saturated magnetization moment. We
+utilized both the electromagnetic induction method using magnetic pick-up coils
+and magneto-optical spectroscopies of the $d$-$d$ transitions and the
+exciton-magnon-phonon transitions to study the magnetic properties subjected to
+ultra-high magnetic fields. Anomalies were observed in magneto-optical
+absorption intensity as well as differential magnetization prior to a fully
+polarized magnetic phase (a vacuum state in the magnon picture), revealing a
+novel magnetic phase associated with changes in both crystal and magnetic
+structures accompanied by the first order phase transition. Magnetic superfluid
+state such as an umbrella-like magnetic structure or a spin nematic state, is
+proposed as a candidate for the novel magnetic phase, which is found universal
+in the series of chromium spinel oxides, $A$Cr$_2$O$_4$ ($A$ = Zn, Cd, Hg).",1302.3664v1
+2022-09-22,Growth or Decay -- I: universality of the turbulent dynamo saturation,"The turbulent small-scale dynamo (SSD) is likely to be responsible for the
+magnetisation of the interstellar medium (ISM) that we observe in the Universe
+today. The SSD efficiently converts kinetic energy $E_{\rm kin}$ into magnetic
+energy $E_{\rm mag} $, and is often used to explain how an initially weak
+magnetic field with $E_{\rm mag} \ll E_{\rm kin}$ is amplified, and then
+maintained at a level $E_{\rm mag} \lesssim E_{\rm kin}$. Usually, this process
+is studied by initialising a weak seed magnetic field and letting the
+turbulence grow it to saturation. However, in this Part I of the Growth or
+Decay series, using three-dimensional, visco-resistive magnetohydrodynamical
+turbulence simulations up to magnetic Reynolds numbers of 2000, we show that
+the same final state in the integral quantities, energy spectra, and
+characteristic scales of the magnetic field can also be achieved if initially
+$E_{\rm mag} \sim E_{\rm kin}$ or even if initially $E_{\rm mag} \gg E_{\rm
+kin}$. This suggests that the final saturated state of the turbulent dynamo is
+set by the turbulence and the material properties of the plasma, independent of
+the initial structure or amplitude of the magnetic field. We discuss the
+implications this has for the maintenance of magnetic fields in turbulent
+plasmas and future studies exploring the dynamo saturation.",2209.10749v2
+2015-06-06,Saturation of the Turbulent Dynamo,"The origin of strong magnetic fields in the Universe can be explained by
+amplifying weak seed fields via turbulent motions on small spatial scales and
+subsequently transporting the magnetic energy to larger scales. This process is
+known as the turbulent dynamo and depends on the properties of turbulence, i.e.
+on the hydrodynamical Reynolds number and the compressibility of the gas, and
+on the magnetic diffusivity. While we know the growth rate the magnetic energy
+in the linear regime, the saturation level, i.e. the ratio of magnetic energy
+to turbulent kinetic energy that can be reached, is not known from analytical
+calculations. In this paper we present the first scale-dependent saturation
+model based on an effective turbulent resistivity which is determined by the
+turnover timescale of turbulent eddies and the magnetic energy density. The
+magnetic resistivity increases compared to the Spitzer value and the effective
+scale on which the magnetic energy spectrum is at its maximum moves to larger
+spatial scales. This process ends when the peak reaches a characteristic
+wavenumber k* which is determined by the critical magnetic Reynolds number. The
+saturation level of the dynamo also depends on the type of turbulence and
+differs for the limits of large and small magnetic Prandtl numbers Pm. With our
+model we find saturation levels between 43.8% and 1.3% for Pm>>1 and between
+2.43% and 0.135% for Pm<<1, where the higher values refer to incompressible
+turbulence and the lower ones to highly compressible turbulence.",1506.02182v2
+2013-01-31,Asymptotic theory of magnetic island saturation in equilibria with a finite current gradient,"A novel asymptotic matching procedure is developed to revisit the problem of
+magnetic island saturation in case of a finite current gradient at the rational
+surface. Nonlinear dispersion relation is derived for saturated magnetic
+island. It is shown that arbitrary normalization factors that were present in
+previous theories are fully specified with the asymptotic matching.",1302.0024v2
+2023-07-18,"Propagation of Coupled Acoustic, Electromagnetic and Spin Waves in Saturated Ferromagnetoelastic Solids","We study the propagation of plane waves in an unbounded body of a saturated
+ferromagnetoelastic solid. The equations by Tiersten for small fields
+superposed on finite initial fields in a saturated ferromagnetoelastic material
+are employed, with their quasistatic magnetic field extended to dynamic
+electric and magnetic fields for electromagnetic waves. Dispersion relations of
+the plane waves are obtained. The cutoff frequencies and long wave
+approximation of the dispersion curves are determined. Results show that
+acoustic, electromagnetic and magnetic spin waves are coupled in such a
+material. For YIG which is a cubic crystal without piezoelectric coupling, the
+acoustic and electromagnetic waves are not directly coupled but they can still
+interact indirectly through spin waves.",2307.09171v1
+2014-05-14,Ferromagnetism and quantum anomalous Hall effect in one-side-saturated buckled honeycomb lattices,"The recently synthesized silicene as well as theoretically discussed
+germanene are examples of buckled honeycomb structures. The buckled structures
+allow one to manipulate asymmetry between two underlying sublattices of
+honeycomb structures. Here by taking germanene as a prototype of buckled
+honeycomb lattices, we explore magnetism induced by breaking sublattice
+symmetry through saturating chemical bonds on one-side of the buckled honeycomb
+lattice. It is shown that when fractions of chemical bonds on one-side are
+saturated, two narrow bands always exist at half filling. Furthermore, the
+narrow bands generally support flat band ferromagnetism in the presence of the
+Hubbard $U$ interaction. The induced magnetization is directly related to the
+saturation fraction and is thus controllable in magnitude through the
+saturation fraction. Most importantly, we find that depending on the saturation
+fraction, the ground state of an one-side saturated germanene may become a
+quantum anomalous Hall (QAH) insulator characterized by a Chern number that
+vanishes for larger magnetization. The non-vanishing Chern number for smaller
+magnetization implies that the associated quantum Hall effect tends to survive
+at high temperatures. Our findings provide a potential method to engineer
+buckled honeycomb structures into high-temperature QAH insulators.",1405.3349v1
+2022-09-28,Numerical Study of S=1/2 Heisenberg Antiferromagnet on the Floret Pentagonal Lattice,"The $S=1/2$ Heisenberg antiferromagnet on the floret-pentagonal lattice with
+two kinds of interaction strength is studied by the numerical-diagonalization
+method. It is known that, near the five-ninth of the saturation magnetization,
+this system shows a magnetization jump that is not accompanied by magnetization
+plateaux. We focus our attention on the behavior of this system around the
+five-ninth of the saturation magnetization; the changes of the magnetization
+jump and plateau at and around this magnetization are clarified from the
+diagonalization data for finite-size systems up to 45 sites.",2209.13887v1
+2017-12-11,Transition to turbulent dynamo saturation,"While the saturated magnetic energy is independent of viscosity in dynamo
+experiments, it remains viscosity-dependent in state-of-the-art 3D direct
+numerical simulations (DNS). Extrapolating such viscous scaling-laws to
+realistic parameter values leads to an underestimation of the magnetic energy
+by several orders of magnitude. The origin of this discrepancy is that fully 3D
+DNS cannot reach low enough values of the magnetic Prandtl number $Pm$. To
+bypass this limitation and investigate dynamo saturation at very low $Pm$, we
+focus on the vicinity of the dynamo threshold in a rapidly rotating flow: the
+velocity field then depends on two spatial coordinates only, while the magnetic
+field consists of a single Fourier mode in the third direction. We perform
+numerical simulations of the resulting set of reduced equations for $Pm$ down
+to $2\cdot 10^{-5}$. This parameter regime is currently out of reach to fully
+3D DNS. We show that the magnetic energy transitions from a high-$Pm$ viscous
+scaling regime to a low-$Pm$ turbulent scaling regime, the latter being
+independent of viscosity. The transition to the turbulent saturation regime
+occurs at a low value of the magnetic Prandtl number, $Pm \simeq 10^{-3}$,
+which explains why it has been overlooked by numerical studies so far.",1712.03787v1
+2018-02-24,Non-saturating Quantum Magnetization in Weyl semimetal TaAs,"Detecting the spectroscopic signatures of Dirac-like quasiparticles in
+emergent topological materials is crucial for searching their potential
+applications. Magnetometry is a powerful tool for fathoming electrons in
+solids, yet its ability for discerning Dirac-like quasiparticles has not been
+recognized. Adopting the probes of magnetic torque and parallel magnetization
+for the archetype Weyl semimetal TaAs in strong magnetic field, we observed a
+quasi-linear field dependent effective transverse magnetization and a strongly
+enhanced parallel magnetization when the system is in the quantum limit.
+Distinct from the saturating magnetic responses for massive carriers, the
+non-saturating signals of TaAs in strong field is consistent with our newly
+developed magnetization calculation for a Weyl fermion system in an arbitrary
+angle. Our results for the first time establish a thermodynamic criterion for
+detecting the unique magnetic response of 3D massless Weyl fermions in the
+quantum limit.",1802.08801v1
+2021-09-24,Saturation mechanism of the fluctuation dynamo in supersonic turbulent plasmas,"Magnetic fields in several astrophysical objects are amplified and maintained
+by a dynamo mechanism, which is the conversion of the turbulent kinetic energy
+to magnetic energy. A dynamo that amplifies magnetic fields at scales $<$ the
+driving scale of turbulence is known as the fluctuation dynamo. We study the
+properties of the fluctuation dynamo in supersonic turbulent plasmas, which is
+of relevance to the ISM, structure formation, and lab experiments of
+laser-plasma turbulence. Using simulations, we explore the properties of the
+exponentially growing and saturated state of the fluctuation dynamo for
+subsonic and supersonic turbulence. We confirm that the fluctuation dynamo
+efficiency decreases with compressibility. We show that the fluctuation dynamo
+generated magnetic fields are spatially intermittent and the level of
+intermittency decreases as the field saturates. We find a stronger back
+reaction of the magnetic field on the velocity for the subsonic case as
+compared to the supersonic case. Locally, we find that the level of alignment
+between vorticity and velocity, velocity and magnetic field, and current
+density and magnetic field in the saturated stage is enhanced in comparison to
+the exponentially growing phase for the subsonic case, but only the current
+density and magnetic field alignment is enhanced for the supersonic case. We
+show that both the magnetic field amplification (due to weaker stretching of
+field lines) and diffusion decreases when the field saturates, but the
+diffusion is enhanced relative to amplification. This occurs throughout the
+volume in the subsonic turbulence, but primarily in the strong-field regions
+for the supersonic case. This leads to the saturation of the fluctuation
+dynamo. Overall, both the amplification and diffusion of magnetic fields are
+affected and thus a drastic change in either of them is not required for the
+saturation. [Abstract abridged]",2109.11698v1
+2011-03-16,Magnetization Plateaus in the Spin-1/2 Kagome Antiferromagnets: Volborthite and Vesignieite,"The magnetization of two spin-1/2 kagome antiferromagnets, volborthite and
+vesignieite, has been measured in pulsed magnetic fields up to 68 T. A
+magnetization plateau is observed for each compound near the highest magnetic
+field. Magnetizations at saturation are approximately equal to 0.40Ms for both
+compounds, where Ms is the fully saturated magnetization, irrespective of a
+difference in the distortion of the kagome lattice between the two compounds.
+It should be noted that these values of magnetizations are significantly larger
+than Ms/3 predicted theoretically for the one-third magnetization plateau in
+the spin-1/2 kagome antiferromagnet. The excess magnetization over Ms/3 is
+nearly equal to the sum of the magnetizations gained at the second and third
+magnetization steps in volborthite, suggesting that there is a common origin
+for the excess magnetization and the magnetization steps.",1103.3116v1
+2005-06-23,"Magnetic phase diagram copper metaborate CuB_2O_4 in magnetic field parallel c-axis: resonant, magnetic and magnetoelastic investigations","The magnetic phase diagram in a single crystal of copper metaborate CuB_2O_4
+in a magnetic field parallel to a tetragonal axis $c$ has been investigated.
+  From the resonant, magnetic and magnetostrictive data the phase diagram of
+CuB_2O_4 on a plane ``temperature - magnetic field'' is constructed. The
+magnetic incommensurate-commensurate phase transition is caused by the
+saturation of weak subsystem of copper ions in the strong magnetic field
+$H\|c$.",0506596v1
+2014-06-08,Stability and magnetization curve of spin-nematic phase slightly below saturation field,"We discuss the magnetization process slightly below the saturation field in
+frustrated magnets. A condensation of bound magnons on the spin-polarized state
+induces either a spin nematic phase or a state with phase separation. The
+(effective) interaction between the bound magnon pairs not only is crucial to
+the stability of the nematic phase, but also determines the slope of the
+magnetization curve near saturation. We generally derive the expression of this
+interaction by using the perturbative scattering theory. By applying the method
+to coupled zigzag chains LiCuVO4, we find the positive pair-pair interaction
+implying the stability of the spin nematic phase. We also point out that the
+magnetization curve of LiCuVO4 is almost vertical (i.e. very large dM/dH) near
+the saturation exhibiting one-dimensional feature despite non-negligible
+interchain couplings.",1406.1960v1
+2011-08-10,A route towards finding large magnetic anisotropy in nano-composites: application to a W$_{1-x}$Re$_x$/Fe multilayer,"We suggest here a novel nano-laminate, 5[Fe]/2[W$_x$Re$_{1-x}$] (x=0.6-0.8),
+with enhanced magnetic hardness in combination with a large saturation moment.
+The calculated magnetic anisotropy of this material reaches values of 5.3-7.0
+MJ/m$^3$, depending on alloying conditions. We also propose a recipe in how to
+identify other novel magnetic materials, such as nano-laminates and
+multilayers, with large magnetic anisotropy in combination with a high
+saturation moment.",1108.2105v1
+2012-02-15,Magnetic field amplification during gravitational collapse - Influence of initial conditions on dynamo evolution and saturation,"We study the influence of initial conditions on the magnetic field
+amplification during the collapse of a magnetised gas cloud. We focus on the
+dependence of the growth and saturation level of the dynamo generated field on
+the turbulent properties of the collapsing cloud. In particular, we explore the
+effect of varying the initial strength and injection scale of turbulence and
+the initial uniform rotation of the collapsing magnetised cloud. In order to
+follow the evolution of the magnetic field in both the kinematic and the
+nonlinear regime, we choose an initial field strength of $\simeq 1\,\mkG$ with
+the magnetic to kinetic energy ratio, $E_{\rm m}/E_{\rm k} \sim 10^{-4}$. Both
+gravitational compression and the small-scale dynamo initially amplify the
+magnetic field. Further into the evolution, the dynamo-generated magnetic field
+saturates but the total magnetic field continues to grow because of
+compression. The saturation of the small-scale dynamo is marked by a change in
+the slope of $B/\rho^{2/3}$ and by a shift in the peak of the magnetic energy
+spectrum from small scales to larger scales. For the range of initial Mach
+numbers explored in this study, the dynamo growth rate increases as the Mach
+number increases from $v_{\rm rms}/c_{\rm s}\sim 0.2$ to 0.4 and then starts
+decreasing from $v_{\rm rms}/c_{\rm s}\sim 1.0$. We obtain saturation values of
+$E_{\rm m}/E_{\rm k} = 0.2 - 0.3$ for these runs. Simulations with different
+initial injection scales of turbulence also show saturation at similar levels.
+For runs with different initial rotation of the cloud, the magnetic energy
+saturates at $E_{\rm m}/E_{\rm k}\sim 0.2 - 0.4$ of the equipartition value.
+(Abridged)",1202.3206v1
+2015-10-14,Dynamo saturation in direct simulations of the multi-phase turbulent interstellar medium,"The ordered magnetic field observed via polarized synchrotron emission in
+nearby disc galaxies can be explained by a mean-field dynamo operating in the
+diffuse interstellar medium (ISM). Additionally, vertical-flux initial
+conditions are potentially able to influence this dynamo via the occurrence of
+the magneto-rotational instability (MRI). We aim to study the influence of
+various initial field configurations on the saturated state of the mean-field
+dynamo. This is motivated by the observation that different saturation behavior
+was previously obtained for different supernova rates. We perform direct
+numerical simulations (DNS) of three-dimensional local boxes of the vertically
+stratified, turbulent interstellar medium, employing shearing-periodic boundary
+conditions horizontally. Unlike in our previous work, we also impose a vertical
+seed magnetic field. We run the simulations until the growth of the magnetic
+energy becomes negligible. We furthermore perform simulations of equivalent 1D
+dynamo models, with an algebraic quenching mechanism for the dynamo
+coefficients. We compare the saturation of the magnetic field in the DNS with
+the algebraic quenching of a mean-field dynamo. The final magnetic field
+strength found in the direct simulation is in excellent agreement with a
+quenched $\alpha\Omega$~dynamo. For supernova rates representative of the Milky
+Way, field losses via a Galactic wind are likely responsible for saturation. We
+conclude that the relative strength of the turbulent and regular magnetic
+fields in spiral galaxies may depend on the galaxy's star formation rate. We
+propose that a mean field approach with algebraic quenching may serve as a
+simple sub-grid scale model for galaxy evolution simulations including a
+prescribed feedback from magnetic fields.",1510.04178v1
+2004-05-05,Radiation Chemistry of Organic Liquids: Saturated Hydrocarbons,"In this review (124 refs), several problems in radiolysis of saturated
+hydrocarbons are examined. Special attention is paid to the chemistry of
+radical cations, high-mobility holes, excited state and spur dynamics, magnetic
+field and spin effects, and optically detected magnetic resonance spectroscopy.",0405014v1
+2007-11-08,Phenomenology of turbulent dynamo growth and saturation,"With a non local shell model of magnetohydrodynamic turbulence we investigate
+numerically the turbulent dynamo action for low and high magnetic Prandtl
+numbers ($Pm$). The results obtained in the kinematic regime and along the way
+to dynamo saturation are understood in terms of a phenomenological approach
+based on the local ($Pm\ll 1$) or non local ($Pm\gg 1$) nature of the energy
+transfers. In both cases the magnetic energy grows at small scale and saturates
+as an inverse `` cascade ''.",0711.1237v1
+2022-04-29,Saturation of turbulent helical dynamos,"The presence of large scale magnetic fields in nature is often attributed to
+the inverse cascade of magnetic helicity driven by turbulent helical dynamos.
+In this work we show that in turbulent helical dynamos, the inverse flux of
+magnetic helicity towards the large scales $\Pi_{\mathcal{H}}$ is bounded by
+$|\Pi_{\mathcal{H}}|\le c \epsilon k_\eta^{-1}$, where $\epsilon$ is the energy
+injection rate, $k_\eta$ is the Kolmogorov magnetic dissipation wavenumber and
+$c$ an order one constant. Assuming the classical isotropic turbulence scaling,
+the inverse flux of magnetic helicity $\Pi_{\mathcal{H}}$ decreases at least as
+a $-3/4$ power-law with the magnetic Reynolds number $Rm$ : $|\Pi_{\mathcal{H}}
+| \le c \epsilon \ell_f Rm^{-3/4}\max[Pm,1]^{1/4}$, where $Pm$ the magnetic
+Prandtl number and $\ell_f$ the forcing lengthscale. We demonstrate this
+scaling with $Rm$ using direct numerical simulations of turbulent dynamos
+forced at intermediate scales. The results further indicate that nonlinear
+saturation is achieved by a balance between the inverse cascade and dissipation
+at domain size scales $L$ for which the saturation value of the magnetic energy
+is bounded by ${\mathcal{E}}_\text{m}\leq c L (\epsilon \ell_f)^{2/3}
+Rm^{1/4}\max[1,Pm]^{1/4}$. Numerical simulations also demonstrate this bound.",2204.14091v2
+2008-10-29,The saturation of the electron beam filamentation instability by the self-generated magnetic field and magnetic pressure gradient-driven electric field,"Two counter-propagating cool and equally dense electron beams are modelled
+with particle-in-cell (PIC) simulations. The electron beam filamentation
+instability is examined in one spatial dimension. The box length resolves one
+pair of current filaments. A small, a medium-sized and a large filament are
+considered and compared. The magnetic field amplitude at the saturation time of
+the filamentation instability is proportional to the filament size. It is
+demonstrated, that the force on the electrons imposed by the electrostatic
+field, which develops during the nonlinear stage of the instability, oscillates
+around a mean value that equals the magnetic pressure gradient force. The
+forces acting on the electrons due to the electrostatic and the magnetic field
+have a similar strength. The electrostatic field reduces the confining force
+close to the stable equilibrium of each filament and increases it farther away.
+The confining potential is not sinusoidal, as assumed by the magnetic trapping
+model, and it permits an overlap of current filaments (plasmons) with an
+opposite flow direction. The scaling of the saturation amplitude of the
+magnetic field with the filament size observed here thus differs from that
+expected from the magnetic trapping model. The latter nevertheless gives a good
+estimate for the magnetic saturation amplitude. The increase of the peak
+electrostatic and magnetic field amplitudes with the filament size implies,
+that the electrons heat up more and that the spatial modulation of their mean
+speed along the beam flow direction increases with the filament size.",0810.5267v1
+2015-11-22,Passively Q-switched EDFL using Fe3O4-nanoparticle saturable absorber,"We experimentally demonstrate a passively Q-switched erbium-doped fiber laser
+(EDFL) operation by using a saturable absorber based on Fe3O4 nanoparticles
+(FONP) in magnetic fluid (MF). As a kind of transition metal oxide, the FONP
+has a large nonlinear optical response with a fast response time for saturable
+absorber. By depositing MF at the end of optical fiber ferrule, we fabricated a
+FONP-based saturable absorber, which enables a strong light-matter interaction
+owing to the confined transmitted optical field within the single mode fiber.
+Because of large third-order optical nonlinearities of FONP-based saturable
+absorber, large modulation depth of 8.2% and non saturable absorption of 56.6%
+are demonstrated. As a result, stable passively Q-switched EDFL pulses with
+maximum output pulse energy of 23.76 nJ, repetition rate of 33.3 kHz, and pulse
+width of 3.2 {\mu}s are achieved when the input pump power is 110 mW at the
+wavelength of 980 nm. The laser features a low threshold pump power of ~15 mW.",1511.07016v1
+2021-05-10,Influence of grain morphology and orientation on saturation magnetostriction of polycrystalline Terfenol-D,"In this work we computationally study the effect of microstructure on
+saturation magnetostriction of Terfenol-D (Tb$_{0.27}$Dy$_{0.73}$Fe$_{2}$) by
+means of Finite Element Method. The model is based on the equilibrium
+magnetoelastic strain tensor at magnetic saturation, and shows that the crystal
+orientation might play a more significant role on saturation magnetostriction
+than the morphology of the grains. We also calculate the dependence of
+saturation magnetostriction on the dispersion angle of the distribution of
+grains in the oriented growth crystal directions $<011>$ and $<111>$, finding
+that not highly oriented grain distributions reduce saturation magnetostriction
+significantly. This result evinces the importance of high-quality control of
+grain orientation in the synthesis of grain-aligned polycrystalline Terfenol-D,
+and provides a quantitative estimation for the range of acceptable values for
+the dispersion angle of the distribution of the oriented grains.",2105.04315v4
+2021-04-30,Correction of FLASH-based MT saturation in human brain for residual bias of B1-inhomogeneity at 3T,"Background: Magnetization transfer (MT) saturation reflects the additional
+saturation of the MRI signal imposed by an MT pulse and is largely driven by
+the saturation of the bound pool. This reduction of the bound polarization by
+the MT pulse is less efficient than predicted by the differential B1-square law
+of absorption. Thus, B1 inhomogeneities lead to a residual bias in the MT
+saturation maps. We derive a heuristic correction to reduce this bias for a
+widely used multi-parameter mapping protocol at 3T. Methods: The amplitude of
+the MT pulse was varied via the nominal flip angle to mimic variations in B1.
+The MT saturation's dependence on the actual flip angle features a linear
+correction term, which was determined separately for gray and white matter.
+Results: The deviation of MT saturation from differential B1-square law is well
+described by a linear decrease with the actual flip angle of the MT pulse. This
+decrease showed no significant differences between gray and white matter. Thus,
+the post hoc correction does not need to take different tissue types into
+account. Bias-corrected MT saturation maps appeared more symmetric and
+highlighted highly myelinated tracts. Discussion: Our correction involves a
+calibration that is specific for the MT pulse. While it can also be used to
+rescale nominal flip angles, different MT pulses and/or protocols will require
+individual calibration. Conclusion: The suggested B1 correction of the MT maps
+can be applied post hoc using an independently acquired flip angle map.",2104.14878v1
+2008-10-28,Evidence for Magnetic Flux Saturation in Rapidly Rotating M Stars,"We present magnetic flux measurements in seven rapidly rotating M dwarfs. Our
+sample stars have X-ray and H-alpha emission indicative of saturated emission,
+i.e., emission at a high level independent of rotation rate. Our measurements
+are made using near-infrared FeH molecular spectra observed with HIRES at Keck.
+Because of their large convective overturn times, the rotation velocity of M
+stars with small Rossby numbers is relatively slow and does not hamper the
+measurement of Zeeman splitting. The Rossby numbers of our sample stars are as
+small as 0.01. All our sample stars exhibit magnetic flux of kilo-Gauss
+strength. We find that the magnetic flux saturates in the same regime as
+saturation of coronal and chromospheric emission, at a critical Rossby number
+of around 0.1. The filling factors of both field and emission are near unity by
+then. We conclude that the strength of surface magnetic fields remains
+independent of rotation rate below that; making the Rossby number yet smaller
+by a factor of ten has little effect. These saturated M-star dynamos generate
+an integrated magnetic flux of roughly 3 kG, with a scatter of about 1 kG. The
+relation between emission and flux also has substantial scatter.",0810.5139v1
+2014-05-28,"Electron Heating, Magnetic Field Amplification, and Cosmic Ray Precursor Length at Supernova Remnant Shocks","We investigate the observability, by direct and indirect means, of a shock
+precursor arising from magnetic field amplification by cosmic rays. We estimate
+the depth of such a precursor under conditions of nonresonant amplification,
+which can provide magnetic field strengths comparable to those inferred for
+supernova remnants. Magnetic field generation occurs as the streaming cosmic
+rays induce a plasma return current, and may be quenched either by nonresonant
+or resonant channels. In the case of nonresonant saturation, the cosmic rays
+become magnetized and amplification saturates at higher magnetic fields. The
+precursor can extend out to $10^{17} - 10^{18}$ cm and is potentially
+detectable. If resonant saturation occurs, the cosmic rays are scattered by
+turbulence and the precursor length will likely be much smaller.
+  The dependence of precursor length on shock velocity has implications for
+electron heating. In the case of resonant saturation, this dependence is
+similar to that in the more familiar resonantly generated shock precursor,
+which when expressed in terms of the cosmic ray diffusion coefficient
+$\varkappa $ and shock velocity $v_s$ is $\varkappa /v_s$. In the nonresonantly
+saturated case, the precursor length declines less quickly with increasing
+$v_s$. Where precursor length proportional to $1/v_s$ gives constant electron
+heating, this increased precursor length could be expected to lead to higher
+electron temperatures for nonresonant amplification. This should be expected at
+faster supernova remnant shocks than studied by previous works. Existing
+results and new data analysis of SN 1006 and Cas A suggest some observational
+support for this idea.",1405.7332v1
+2017-03-16,"3D magnetization currents, magnetization loop, and saturation field in superconducting rectangular prisms","Bulk superconductors are used in both many applications and material
+characterization experiments, being the bulk shape of rectangular prism very
+frequent. However the magnetization currents are still mostly unknown for this
+kind of three dimensional (3D) shape, specially below the saturation magnetic
+field. Knowledge of the magnetization currents in this kind of samples is
+needed to interpret the measurements and the development of bulk materials for
+applications. This article presents a systematic analysis of the magnetization
+currents in prisms of square base and several thicknesses. We make this study
+by numerical modeling using a variational principle that enables high number of
+degrees of freedom. We also compute the magnetization loops and the saturation
+magnetic field, using a definition that is more relevant for thin prisms than
+previous ones. The article presents a practical analytical fit for any aspect
+ratio. For applied fields below the saturation field, the current paths are not
+rectangular, presenting 3D bending. The thickness-average results are
+consistent with previous modeling and measurements for thin films. The 3D
+bending of the current lines indicates that there could be flux cutting effects
+in rectangular prisms. The component of the critical current density in the
+applied field direction may play a role, being the magnetization currents in a
+bulk and a stack of tapes not identical.",1703.05529v3
+2009-04-07,Saturated magnetic field amplification at supernova shocks,"Cosmic-ray streaming instabilities at supernova shocks are discussed in the
+quasilinear diffusion formalism which takes into account the feedback effect of
+wave growth on the cosmic ray streaming motion. In particular, the nonresonant
+instability that leads to magnetic field amplification in the short wavelength
+regime is considered. The linear growth rate is calculated using kinetic theory
+for a streaming distribution. We show that the nonresonant instability is
+actually driven by a compensating current in the background plasma. The
+nonresonant instability can develop into a nonlinear regime generating
+turbulence. The saturation of the amplified magnetic fields due to particle
+diffusion in the turbulence is derived analytically. It is shown that the
+evolution of parallel and perpendicular cosmic-ray pressures is predominantly
+determined by nonresonant diffusion. However, the saturation is determined by
+resonant diffusion which tends to reduce the streaming motion through pitch
+angle scattering. The saturated level can exceed the mean background magnetic
+field.",0904.1038v1
+2011-04-21,Edge Saturation effects on the magnetism and band gaps in multilayer graphene ribbons and flakes,"Using a density functional theory based electronic structure method and
+semi-local density approximation, we study the interplay of geometric
+confinement, magnetism and external electric fields on the electronic structure
+and the resulting band gaps of multilayer graphene ribbons whose edges are
+saturated with molecular hydrogen (H$_2$) or hydroxyl (OH) groups. We discuss
+the similarities and differences of computed features in comparison with the
+atomic hydrogen (or H-) saturated ribbons and flakes. For H$_2$
+edge-saturation, we find \emph{shifted} labeling of three armchair ribbon
+classes and magnetic to non-magnetic transition in narrow zigzag ribbons whose
+critical width changes with the number of layers. Other computed
+characteristics, such as the existence of a critical gap and external electric
+field behavior, layer dependent electronic structure, stacking-dependent band
+gap induction and the length confinement effects remain qualitatively same with
+those of H-saturated ribbons.",1104.4354v1
+2014-10-23,Magnetic phase diagram slightly below the saturation field in the stacked $J_1$-$J_2$ model in the square lattice with the $J_{\text{C}}$ interlayer coupling,"We study the effect of adding interlayer coupling to the square lattice,
+$J_1$-$J_2$ Heisenberg model in high external magnetic field. In particular, we
+consider a cubic lattice formed from stacked $J_1$-$J_2$ layers, with
+interlayer exchange coupling $J_{\text{C}}$. For the 2-dimensional model
+($J_{\text{C}}=0$) it has been shown that a spin-nematic phase appears close to
+the saturation magnetic field for the parameter range $-0.4 \lesssim J_2/J_1$
+and $J_2>0$. We determine the phase diagram for 3-dimensional model at high
+magnetic field by representing spin flips out of the saturated state as bosons,
+considering the dilute boson limit and using the Bethe-Salpeter equation to
+determine the first instability of the saturated paramagnet. Close to the
+highly frustrated point $J_2/J_1\sim0.5$, we find that the spin-nematic state
+is stable even for $|J_{\text{C}}/J_1|\sim 1$. For larger values of $J_2/J_1$,
+interlayer coupling favors a broad, phase-separated region. Further increase of
+$|J_{\text{C}}|$ stabilizes a collinear antiferromagnet, which is selected via
+the order-by-disorder mechanism.",1410.8094v3
+2020-04-15,Noise-Induced Magnetic Field Saturation in Kinetic Simulations,"Monte Carlo methods are often employed to numerically integrate kinetic
+equations, such as the particle-in-cell method for the plasma kinetic equation,
+but these methods suffer from the introduction of counting noise to the
+solution. We report on a cautionary tale of counting noise modifying the
+nonlinear saturation of kinetic instabilities driven by unstable beams of
+plasma. We find a saturated magnetic field in under-resolved particle-in-cell
+simulations due to the sampling error in the current density. The noise-induced
+magnetic field is anomalous, as the magnetic field damps away in continuum
+kinetic and increased particle count particle-in-cell simulations. This
+modification of the saturated state has implications for a broad array of
+astrophysical phenomena beyond the simple plasma system considered here, and it
+stresses the care that must be taken when using particle methods for kinetic
+equations.",2004.07255v2
+1994-09-12,New observational limits on dynamo saturation in young solar-type stars,"We present statistically robust observational evidence which imposes new
+limits on dynamo saturation in young solar-type stars. These are inferred from
+the increasing amplitude of the V-band optical flux with rotation, caused by
+the filling of the disc with surface spots in a non-axisymmetric pattern.
+Assuming spot coverage acts as a tracer of the total magnetic surface flux we
+find that the magnetic activity saturates at a level at least 6 -- 10 times
+greater than that inferred from chromospheric and transition line indicators.
+We suggest that these new limits imply a minimum rotation for saturation of the
+dynamo and that for high rotation rates starspot coverage acts as an
+alternative diagnostic for the stellar dynamo to the chromospheric and
+transition region line emission fluxes. The fact that the dynamo does not
+appear to saturate at the low rotation rates indicated by chromospheric
+indicators should assist evolutionary braking models that have to explain the
+sudden spin-down of young fast rotating G-dwarfs. ( + 3 figures, available on
+request) To appear in Astronomy and Astrophysics (A&A latex style file,
+laa.sty, included at beginning of file)",9409023v1
+2014-02-20,On the saturation of non-axisymmetric instabilites of magnetized spherical Couette flow,"We numerically investigate the saturation of the hydromagnetic instabilities
+of a magnetized spherical Couette flow. Previous simulations [Hollerbach, 2009]
+demonstrated region where the axisymmetric flow, calculated from a 2-D
+simulation, was linearly unstable to nonaxisymmetric perturbations. Full,
+nonlinear, 3d simulations [Hollerbach 2009, Travnikov 2011] showed that the
+saturated state would consist only of harmonics of one azimuthal wave number,
+though there were bifurcations and transitions as nondimensional parameters
+(Re, Ha) were varied. Here, the energy transfer between different aziumthal
+modes is formulated as a network. This demonstrates a mechanism or the
+saturation of one mode and for the suppression of other unstable modes. A given
+mode grows by extracting energy from the axisymmetric flow, and then saturates
+as the energy transfer to its second harmonic equals this inflow. At the same
+time, this mode suppresses other unstable modes by facilitating an energy
+transfer to linearly stable modes.",1402.5064v2
+2019-09-13,Modeling the Saturation of the Bell Instability Using Hybrid Simulations,"The nonresonant cosmic ray instability, predicted by Bell (2004), is thought
+to play an important role in the acceleration and confinement of cosmic rays
+(CRs) close to supernova remnants. Despite its importance, the exact mechanism
+responsible for the saturation of the instability has not been determined, and
+there is no first-principle prediction for the amplitude of the saturated
+magnetic field. Using a survey of self-consistent kinetic hybrid simulations
+(with kinetic ions and fluid electrons), we study the saturation of the
+non-resonant streaming instability as a function of the parameters of both the
+thermal background plasma and the CR population. The strength of the saturated
+magnetic field has important implications for both CR acceleration in supernova
+remnants and CR diffusion in the Galaxy.",1909.06481v1
+2012-08-19,Magnetization curve of the kagome-strip-lattice antiferromagnet,"We study the magnetization curve of the Heisenberg model on the
+quasi-one-dimensional kagome-strip lattice that shares the same lattice
+structure in the inner part with the two-dimensional kagome lattice. Our
+numerical calculations based on the density matrix renormalization group method
+reveal that the system shows several magnetization plateaus between zero
+magnetization and the saturated one; we find the presence of the magnetic
+plateaus with the n=7 height of the saturation for n =1,2,3,4,5 and 6 in the S
+=1/2 case, whereas we detect only the magnetic plateaus of n =1,3,5 and 6 in
+the S =1 case. In the cases of n =2,4 and 6 for the S=1/2 system, the
+Oshikawa-Yamanaka-Affleck condition suggests the occurrence of the
+translational symmetry breaking (TSB). We numerically confirm this non-trivial
+TSB in our results of local magnetizations. We have also found that the
+macroscopic jump appears near the saturation field irrespective of the spin
+amplitude as well as the two-dimensional kagome model.",1208.3825v1
+2019-09-29,Effect of Ge-substitution on Magnetic Properties in the Itinerant Chiral Magnet MnSi,"We have investigated the effect of Ge-substitution to the magnetic ordering
+in the B20 itinerant chiral magnet MnSi prepared by melting and annealing under
+ambient pressure. From metallurgical survey, the solubility limit of Ge was
+found to be $x=0.144(5)$ with annealing temperature $T_\mathrm{an} = 1073$ K.
+Magnetization measurements on MnSi$_{1-x}$Ge$_x$ samples show that the helical
+ordering temperature $T_{\mathrm{c}}$ increases rapidly in the low-$x$ range,
+whereas it becomes saturated at higher concentration $x>~0.1$. The Ge
+substitution also increases both the saturation magnetization $M_\mathrm{s}$
+and the critical field to the fully polarized state $H_\mathrm{c2}$. In
+contrast to the saturation behavior of $T_\mathrm{c}$, those parameters
+increase linearly up to the highest Ge concentration investigated. In the
+temperature-magnetic field phase diagram, we found enlargement of the skyrmion
+phase region for large $x$ samples. We, furthermore, observed the non-linear
+behavior of helical modulation vector $k$ as a function of Ge concentration,
+which can be described qualitatively using the mean field approximation.",1909.13246v1
+2023-03-26,The effect of the magnetically dead layer on the magnetization and the magnetic anisotropy of the dextran coated magnetite nanoparticles,"We present a study on the magnetic behavior of dextran-coated magnetite
+nanoparticles (DM NPs) with sizes between 3 and 19 nm, synthesized by
+hydrothermal-assisted co-precipitation method. The decrease of saturation
+magnetization ($M_s$) with decreasing particle size has been modeled by
+assuming the existence of a spin-disordered layer at the particle surface,
+which is magnetically dead. Based on this core-shell model and taking into
+account the weight contribution of the non-magnetic coating layer (dextran) to
+the whole magnetization, the dead layer thickness ($t$) and saturation
+magnetization $M_s$ of the magnetic cores in our samples were estimated to be
+$t = 6.8~\mathrm{\AA}$ and $M_s = 98.8~\mathrm{emu/g}$, respectively. The data
+of $M_s$ were analyzed using a law of approach to saturation, indicating an
+increase in effective magnetic anisotropy ($K_{eff}$) with decreasing particle
+size as expected from the increased surface/volume ratio in small MNPs. The
+obtained $K_{eff}$ values were successfully modeled by including an extra
+contribution of dipolar interactions due to the formation of chain-like
+clusters of MNPs. The surface magnetic anisotropy ($K_s$) was estimated to be
+about $K_s = 1.04\times10^5~\mathrm{J/m^3}$. Our method provides a simple and
+accurate way to obtain the $M_s$ core values in surface-disordered MNPs, a
+relevant parameter required for magnetic modeling in many applications.",2303.14654v1
+1997-07-09,Magnetization Curves of Antiferromagnetic Heisenberg Spin-1/2 Ladders,"Magnetization processes of spin-1/2 Heisenberg ladders are studied using
+strong-coupling expansions, numerical diagonalization of finite systems and a
+bosonization approach. We find that the magnetization exhibits plateaux as a
+function of the applied field at certain rational fractions of the saturation
+value. Our main focus are ladders with 3 legs where plateaux with magnetization
+one third of the saturation value are shown to exist.",9707090v2
+1998-05-04,Ladders in a magnetic field: a strong coupling approach,"We show that non-frustrated and frustrated ladders in a magnetic field can be
+systematically mapped onto an XXZ Heisenberg model in a longitudinal magnetic
+field in the limit where the rung coupling is the dominant one. This mapping is
+valid in the critical region where the magnetization goes from zero to
+saturation. It allows one to relate the properties of the critical phase
+($H_c^1$, $H_c^2$, the critical exponents) to the exchange integrals and
+provide quantitative estimates of the frustration needed to create a plateau at
+half the saturation value for different models of frustration.",9805029v2
+2002-09-24,Dephasing by extremely dilute magnetic impurities revealed by Aharonov-Bohm oscillations,"We have probed the magnetic field dependence of the electron phase coherence
+time $\tau_\phi$ by measuring the Aharonov-Bohm conductance oscillations of
+mesoscopic Cu rings. Whereas $\tau_\phi$ determined from the low-field
+magnetoresistance saturates below 1 K, the amplitude of Aharonov-Bohm $h/e$
+oscillations increases strongly on a magnetic field scale proportional to the
+temperature. This provides strong evidence that a likely explanation for the
+frequently observed saturation of $\tau_\phi$ at low temperature in weakly
+disordered metallic thin films is the presence of extremely dilute magnetic
+impurities.",0209562v1
+2007-10-02,Low temperature magnetization of the S=1/2 kagome antiferromagnet ZnCu_3(OH)_6Cl_2,"The dc-magnetization of the unique S=1/2 kagome antiferromagnet
+Herbertsmithite has been measured down to 0.1K. No sign of spin freezing is
+observed in agreement with former muSR and ac-susceptibility results. The low
+temperature magnetic response is dominated by a defect contribution which
+exhibits a new energy scale $\simeq 1$ K, likely reflecting the coupling of the
+defects. The defect component is saturated at low temperature by H>8T applied
+magnetic fields which enables us to estimate an upper bound for the non
+saturated intrinsic kagome susceptibility at T=1.7K.",0710.0451v1
+1999-11-23,Magnetization-plateau state of the S=3/2 spin chain with single ion anisotropy,"We reexamine the numerical study of the magnetized state of the S=3/2 spin
+chain with single ion anisotropy D(> 0) for the magnetization M=M_{S}/3, where
+M_{S} is the saturation magnetization. We find at this magnetization that for
+D<D_{c1}=0.387 the system is critical and the magnetization plateau does not
+appear. For D > D_{c1}, the parameter region is divided into two parts D_{c1} <
+D < D_{c2}=0.943 and D_{c2} < D. In each region, the system is gapful and the
+M=M_{S}/3 magnetization plateau appears in the magnetization process. From our
+numerical calculation, the intermediate region D_{c1} < D < D_{c2} should be
+characterized by a magnetized valence-bond-solid state.",9911364v1
+2003-09-11,Giant Keplerate molecule Fe30 - the first octopole magnet,"The multipole expansion technique is applied to one of the largest magnetic
+molecules, Fe30. The molecule's dipole, toroid and quadrupole magnetic moments
+are equal to zero (in the absence of magnetic field) so the multipole expansion
+starts from the octopole moment. Probably the Fe30 molecule is the most
+symmetrical magnetic body synthesized so far. The magnetization process is
+considered theoretically in different geometries. Some components of the
+octopole moment experience a jump while the magnetization rises linearly up to
+its saturation value. An elementary octopole moment consisting of four magnetic
+dipoles is proposed as a hint for designing of an experiment for measurement of
+octopole magnetic moment components.",0309282v1
+2009-09-25,Probing punctual magnetic singularities during magnetization process in FePd films,"We report the use of Lorentz microscopy to observe the domain wall structure
+during the magnetization process in FePd thin foils. We have focused on the
+magnetic structure of domain walls of bubble-shaped magnetic domains near
+saturation. Regions are found along the domain walls where the magnetization
+abruptly reverses. Multiscale magnetic simulations shown that these regions are
+vertical Bloch lines (VBL) and the different bubble shapes observed are then
+related to the inner structure of the VBLs. We were thus able to probe the
+presence of magnetic singularities as small as Bloch points in the inner
+magnetization of the domain walls.",0909.4645v1
+2010-04-20,Radiation stability of biocompatibile magnetic fluid,"The radiation stability of biocompatibile magnetic fluid used in nanomedicine
+after electron irradiation was studied. Two types of the water-based magnetic
+fluids were prepared. The first one was based on the magnetite nanoparticles
+stabilized by one surfactant natrium oleate. The second one was biocompatibile
+magnetic fluid stabilized with two surfactants, natrium oleate as a first
+surfactant and Poly(ethylene glycol) (PEG) as a second surfactant. The
+magnetization measurements showed that electron irradiation up to 1000Gy caused
+50% reduction of saturation magnetization in the case of the first sample with
+only one surfactant while in the case of the second biocompatibile magnetic
+fluid, only 25% reduction of saturation magnetization was observed. In the
+first magnetic fluid the radiation caused the higher sedimentation of the
+magnetic particles than in the second case, when magnetic particles are covered
+also with PEG. The obtained results show that PEG behave as a protective
+element.",1004.3448v2
+2019-12-02,Magnetic Inflation and Stellar Mass. V. Intensification and saturation of M dwarf absorption lines with Rossby number,"In young sun-like stars and field M dwarf stars, chromospheric and coronal
+magnetic activity indicators such as H$\alpha$, X-ray and radio emission are
+known to saturate with low Rossby number ($Ro \lesssim 0.1$), defined as the
+ratio of rotation period to convective turnover time. The mechanism for the
+saturation is unclear. In this paper, we use photospheric Ti I and Ca I
+absorption lines in $Y$ band to investigate magnetic field strength in M dwarfs
+for Rossby numbers between 0.01 and 1.0. The equivalent widths of the lines are
+magnetically enhanced by photospheric spots, a global field or a combination of
+the two. The equivalent widths behave qualitatively similar to the
+chromospheric and coronal indicators: we see increasing equivalent widths
+(increasing absorption) with decreasing $Ro$ and saturation of the equivalent
+widths for $Ro \lesssim 0.1$. The majority of M dwarfs in this study are fully
+convective. The results add to mounting evidence that the magnetic saturation
+mechanism occurs at or beneath the stellar photosphere.",1912.01004v1
+2022-01-16,Parallel transmit PUlse design for Saturation Homogeneity (PUSH) for Magnetization Transfer imaging at 7T,"Purpose: This work proposes a novel RF pulse design for parallel transmit
+(pTx) systems to obtain uniform saturation of semisolid magnetization for
+Magnetization Transfer (MT) contrast in the presence of transmit field
+($B_1^+$) inhomogeneities. The semisolid magnetization is usually modeled as
+being purely longitudinal, with the applied $B_1^+$ field saturating but not
+rotating its magnetization, thus standard pTx pulse design methods do not
+apply. Theory and Methods: Pulse design for Saturation Homogeneity (PUSH)
+optimizes pTx RF pulses by considering uniformity of root-mean squared $B_1^+$,
+$B_1^{rms}$, which relates to the rate of semisolid saturation. Here we
+considered designs consisting of a small number of spatially non-selective
+sub-pulses optimized over either a single 2D plane or 3D. Simulations and in
+vivo experiments on a 7T Terra system with an 8-TX Nova head coil in 5 subjects
+were carried out to study the homogenization of $B_1^{rms}$ and of the MT
+contrast by acquiring MT ratio maps. Results: Simulations and in vivo
+experiments showed up to 6 and 2 times more uniform $B_1^{rms}$ compared to
+circular polarized (CP) mode for 2D and 3D optimizations, respectively. This
+translated into 4 and 1.25 times more uniform MT contrast, consistently for all
+subjects, where 2 sub-pulses were enough for the implementation and coil used.
+Conclusion: The proposed PUSH method obtains more uniform and higher MT
+contrast than CP mode within the same SAR budget.",2201.06091v1
+2017-07-19,The Development of Magnetic Field Line Wander by Plasma Turbulence,"Plasma turbulence occurs ubiquitously in space and astrophysical plasmas,
+mediating the nonlinear transfer of energy from large-scale electromagnetic
+fields and plasma flows to small scales at which the energy may be ultimately
+converted to plasma heat. But plasma turbulence also generically leads to a
+tangling of the magnetic field that threads through the plasma. The resulting
+wander of the magnetic field lines may significantly impact a number of
+important physical processes, including the propagation of cosmic rays and
+energetic particles, confinement in magnetic fusion devices, and the
+fundamental processes of turbulence, magnetic reconnection, and particle
+acceleration. The various potential impacts of magnetic field line wander are
+reviewed in detail, and a number of important theoretical considerations are
+identified that may influence the development and saturation of magnetic field
+line wander in astrophysical plasma turbulence. The results of nonlinear
+gyrokinetic simulations of kinetic Alfven wave turbulence of sub-ion length
+scales are evaluated to understand the development and saturation of the
+turbulent magnetic energy spectrum and of the magnetic field line wander. It is
+found that turbulent space and astrophysical plasmas are generally expected to
+contain a stochastic magnetic field due to the tangling of the field by strong
+plasma turbulence. Future work will explore how the saturated magnetic field
+line wander varies as a function of the amplitude of the plasma turbulence and
+the ratio of the thermal to magnetic pressure, known as the plasma beta.",1707.06230v1
+2013-09-27,Structures and Lagrangian statistics of the Taylor-Green Dynamo,"The evolution of a Taylor-Green forced magnetohydrodynamic (MHD) system
+showing dynamo activity is analyzed via direct numerical simulations. The
+statistical properties of the velocity and magnetic field in Eulerian
+coordinates and along trajectories of fluid elements (Lagrangian coordinates)
+are found to change between the kinematic, non-linear and saturated regime.
+Fluid element (tracer) trajectories change from chaotic quasi-isotropic
+(kinematic phase) to mean magnetic field aligned (saturated phase). The
+probability density functions (PDFs) of the magnetic field change from strongly
+non-Gaussian in the kinematic to quasi-Gaussian PDFs in the saturated regime so
+that their flatness give a precise handle on the definition of the limiting
+points of the three regimes. Also the statistics of the fluctuations of the
+kinetic and magnetic energy along fluid trajectories change. All this goes
+along with a dramatic increase of the correlation time of velocity and magnetic
+field fluctuations experienced by tracers significantly exceeding one turbulent
+large-eddy turn-over time. A remarkable consequence is an intermittent scaling
+regime of the Lagrangian magnetic field structure functions at unusually long
+time scales.",1309.7975v2
+2022-06-17,Melting of magnetization plateaus for kagome and square-kagome lattice antiferromagnets,"Unconventional features of the magnetization curve at zero temperature such
+as plateaus or jumps are a hallmark of frustrated spin systems. Very little is
+known about their behavior at non-zero temperatures. Here we investigate the
+temperature dependence of the magnetization curve of the kagome lattice
+antiferromagnet in particular at 1/3 of the saturation magnetization for large
+lattice sizes of up to N=48 spins. We discuss the phenomenon of asymmetric
+melting and trace it back to a combined effect of unbalanced magnetization
+steps on either side of the investigated plateau as well as on the behavior of
+the density of states across the plateau. We compare our findings to the
+square-kagome lattice that behaves similarly at low temperatures at zero field,
+but as we will demonstrate differently at 1/3 of the saturation magnetization.
+Both systems possess a flat one-magnon band and therefore share with the class
+of flat-band systems the general property that the plateau that precedes the
+jump to saturation melts asymmetrically but now with a minimal susceptibility
+that bends towards lower fields with increasing temperature.",2206.08710v3
+2016-03-30,Distributed chaos and solitons at the edges of magnetically confined plasmas,"It is shown, using results of measurements of ion saturation current in the
+plasma edges of different magnetic fusion confinement devices (tokamaks and
+stellarators), that the plasma dynamics in the edges is dominated by
+distributed chaos with spontaneously broken translational symmetry at low
+magnetic field, and with spontaneously broken reflexional symmetry (by helical
+solitons) at high magnetic field.",1603.09186v2
+2013-06-26,Periodic magnetic structures generated by spin-polarized currents in nanostripes,"The influence of a spin-polarized current on long ferromagnetic nanostripes
+is studied numerically. The current flows perpendicularly to the stripe. The
+study is based on the Landau-Lifshitz phenomenological equation with the
+Slonczewski-Berger spin-torque term. The magnetization behavior is analyzed for
+all range of the applied currents, up to the saturation. It is shown that the
+saturation current is a nonmonotonic function of the stripe width. For a stripe
+width increasing it approaches the saturation value for an infinite film. A
+number of stable periodic magnetization structures are observed below the
+saturation. Type of the periodical structure depends on the stripe width.
+Besides the one-dimensional domain structure, typical for narrow wires, and the
+two-dimensional vortex-antivortex lattice, typical for wide films, a number of
+intermediate structures are observed, e.g. cross-tie and diamond state. For
+narrow stripes an analytical analysis is provided.",1306.6296v1
+2017-11-23,Physics of the saturation of particle acceleration in relativistic magnetic reconnection,"We investigate the saturation of particle acceleration in relativistic
+reconnection using two-dimensional particle-in-cell simulations at various
+magnetizations \sigma. We find that the particle energy spectrum produced in
+reconnection quickly saturates as a hard power law that cuts off at
+\gamma~4\sigma, confirming previous work. Using particle tracing, we find that
+particle acceleration by the reconnection electric field in X-points determines
+the shape of the particle energy spectrum. By analyzing the current sheet
+structure, we show that physical cause of saturation is the spontaneous
+formation of secondary magnetic islands that can disrupt particle acceleration.
+By comparing the size of acceleration regions to the typical distance between
+disruptive islands, we show that the maximum Lorentz factor produced in
+reconnection is \gamma ~ 5 \sigma, which is very close to what we find in our
+particle energy spectra. We also show that the dynamic range in Lorentz factor
+of the power law spectrum in reconnection is < 40. The hardness of the power
+law combined with its narrow dynamic range implies that relativistic
+reconnection is capable of producing the hard narrowband flares observed in the
+Crab Nebula but has difficulty producing the softer broadband prompt GRB
+emission.",1711.08701v1
+2009-08-13,Susceptibility at the edge points of magnetization plateau of 1D electron/spin systems,"We study the behavior of magnetization curve as a function of magnetic field
+in the immediate vicinity of the magnetization plateaus of 1D electron systems
+within the bosonization formalism. First we discuss the plateau that is formed
+at the saturation magnetization of 1D electron system. Interactions between
+electrons we treat in the lowest order of perturbation. We show that for
+isolated systems, where total number of electrons is not allowed to vary,
+magnetic susceptibility stays always finite away of half filling. Similar
+statement holds for many other magnetization plateaus supporting nonmagnetic
+gapless excitations encountered in 1D electron/spin systems in the absence of
+special symmetries or features responsible for the mode decoupling. We
+demonstrate it on example of the plateaus at irrational values of magnetization
+in doped modulated Hubbard chains. Finally we discuss the connection between
+the weak coupling description of saturation magnetization plateau and strong
+coupling description of zero magnetization plateau of attractively interacting
+electrons/ antiferromagnetically interacting spin 1 Bosons.",0908.1894v1
+2020-07-09,Shaping nanoscale magnetic domain memory in exchange-coupled ferromagnets by field cooling,"The advance of magnetic nanotechnologies relies on detailed understanding of
+nanoscale magnetic mechanisms in materials. Magnetic domain memory (MDM), i.e.,
+the tendency for magnetic domains to repeat the same pattern during
+field-cycling, is important to many technologies including magnetic recording
+developments. We show coherent x-ray magnetic scattering studies unveiling MDM
+in [Co/Pd]/IrMn films. When illuminated by coherent x-rays, the magnetic
+domains in the [Co/Pd] multilayer produce a speckle pattern unique to their
+specific nanoscale configuration. By cross-correlating such speckle patterns
+throughout the magnetization loop, we measure the MDM. When cooled below its
+blocking temperature, the film exhibits up to 100% MDM, induced by
+exchange-couplings with the IrMn layer. Furthermore, the degree of MDM
+drastically depends on cooling conditions. If the film is cooled under moderate
+fields, MDM is high throughout the entire magnetization loop. If the film is
+cooled under nearly saturating field, MDM vanishes, except at nucleation and
+saturation",2007.04930v1
+2023-05-17,Material Parameters for Faster Ballistic Switching of an In-plane Magnetized Nanomagnet,"High-speed magnetization switching of a nanomagnet is necessary for faster
+information processing. The ballistic switching by a pulsed magnetic filed is a
+promising candidate for the high-speed switching. It is known that the
+switching speed of the ballistic switching can be increased by increasing the
+magnitude of the pulsed magnetic field. However it is difficult to generate a
+strong and short magnetic field pulse in a small device. Here we explore
+another direction to achieve the high-speed ballistic switching by designing
+material parameters such as anisotropy constant, saturation magnetization, and
+the Gilbert damping constant. We perform the macrospin simulations for the
+ballistic switching of in-plane magnetized nano magnets with varying material
+parameters. The results are analyzed based on the switching dynamics on the
+energy density contour. We show that the pulse width required for the ballistic
+switching can be reduced by increasing the magnetic anisotropy constant or by
+decreasing the saturation magnetization. We also show that there exists an
+optimal value of the Gilbert damping constant that minimizes the pulse width
+required for the ballistic switching.",2305.10111v1
+2013-12-09,Magnetic fields in cosmological simulations of disk galaxies,"Observationally, magnetic fields reach equipartition with thermal energy and
+cosmic rays in the interstellar medium of disk galaxies such as the Milky Way.
+However, thus far cosmological simulations of the formation and evolution of
+galaxies have usually neglected magnetic fields. We employ the moving-mesh code
+\textsc{Arepo} to follow for the first time the formation and evolution of a
+Milky Way-like disk galaxy in its full cosmological context while taking into
+account magnetic fields. We find that a prescribed tiny magnetic seed field
+grows exponentially by a small-scale dynamo until it saturates around $z=4$
+with a magnetic energy of about $10\%$ of the kinetic energy in the center of
+the galaxy's main progenitor halo. By $z=2$, a well-defined gaseous disk forms
+in which the magnetic field is further amplified by differential rotation,
+until it saturates at an average field strength of $\sim 6 \mug$ in the disk
+plane. In this phase, the magnetic field is transformed from a chaotic
+small-scale field to an ordered large-scale field coherent on scales comparable
+to the disk radius. The final magnetic field strength, its radial profile and
+the stellar structure of the disk compare well with observational data. A minor
+merger temporarily increases the magnetic field strength by about a factor of
+two, before it quickly decays back to its saturation value. Our results are
+highly insensitive to the initial seed field strength and suggest that the
+large-scale magnetic field in spiral galaxies can be explained as a result of
+the cosmic structure formation process.",1312.2620v2
+2022-07-25,Insight into ground-state spin arrangement and bipartite entanglement of the polymeric coordination compound [Dy$_2$Cu$_2$]$_n$ through the symmetric spin-1/2 Ising-Heisenberg orthogonal-dimer chain,"The ground-state spin arrangement and the bipartite entanglement within
+Cu$^{2+}$-Cu$^{2+}$ dimers across the magnetization process of the 4f-3d
+heterometallic coordination polymer
+[{Dy(hfac)$_2$(CH$_3$OH)}$_2${Cu(dmg)(Hdmg)}$_2$]$_n$ (H$_2$dmg =
+dimethylglyoxime, Hhfac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione) are
+theoretically examined using the symmetric isotropic spin-$1/2$
+Ising-Heisenberg orthogonal-dimer chain. The numerical results point to five
+possible ground states of the compound with three different degrees of the
+quantum entanglement within Cu$^{2+}$-Cu$^{2+}$. Besides the standard
+ferrimagnetic and saturated phases without quantum entanglement of Cu$^{2+}$
+ions, which are manifested in low-temperature magnetization curve as wide
+plateaus at the non-saturated magnetization $16.26\mu_{\rm B}$ and at the
+saturation value $20.82\mu_{\rm B}$, respectively, one also finds an intriguing
+singlet-like phase with just partial entanglement within Cu$^{2+}$-Cu$^{2+}$
+and two singlet phases with fully entangled Cu$^{2+}$-Cu$^{2+}$ dimers. The
+former quantum phase can be identified in the low-temperature magnetization
+process as very narrow intermediate plateau at the magnetization $9.27\mu_{\rm
+B}$ per unit cell, while the latter ones as zero magnetization plateau and
+intermediate plateau at the magnetization $18.54\mu_{\rm B}$. Non-monotonous
+temperature variations of the concurrence, through which the entanglement
+within cooper dimers is quantified, point to the possible temporary thermal
+activation of the entangled states of Cu$^{2+}$-Cu$^{2+}$ also above
+non-entangled ferrimagnetic and saturated phases.",2207.11943v1
+1995-10-06,Magnetic excitations and effects of magnetic fields on the spin-Peierls transition in CuGeO$_3$,"We analyze the magnetic excitations of a spin-1/2 antiferromagnetic
+Heisenberg model with alternating nearest neighbor interactions and uniform
+second neighbor interactions recently proposed to describe the spin-Peierls
+transition in CuGeO$_3$. We show that there is good agreement between the
+calculated excitation dispersion relation and the experimental one. We have
+also shown that this model reproduces satisfactorily the experimental results
+for the magnetization vs. magnetic field curve and its saturation value. The
+model proposed also reproduces qualitatively some features of the magnetic
+phase diagram of this compound and the overall behavior of the magnetic
+specific heat in the presence of applied magnetic fields.",9509160v1
+2010-04-15,Magnetization Process of Kagome-Lattice Heisenberg Antiferromagnet,"The magnetization process of the isotropic Heisenberg antiferromagnet on the
+kagome lattice is studied. Data obtained from the numerical-diagonalization
+method are reexamined from the viewpoint of the derivative of the magnetization
+with respect to the magnetic field. We find that the behavior of the derivative
+at approximately one-third of the height of the magnetization saturation is
+markedly different from that for the cases of typical magnetization plateaux.
+The magnetization process of the kagome-lattice antiferromagnet reveals a new
+phenomenon, which we call the ""magnetization ramp"".",1004.2528v1
+2013-10-23,Magnetization Characteristic of Ferromagnetic Thin Strip by Measuring Anisotropic Magnetoresistance and Ferromagnetic Resonance,"The magnetization characteristic in a permalloy thin strip is investigated by
+electrically measuring the anisotropic magnetoresistance and ferromagnetic
+resonance in in-plane and out-of-plane configurations. Our results indicate
+that the magnetization vector can rotate in the film plane as well as out of
+the film plane by changing the intensity of external magnetic field of certain
+direction. The magnetization characteristic can be explained by considering
+demagnetization and magnetic anisotropy. Our method can be used to obtain the
+demagnetization factor, saturated magnetic moment and the magnetic anisotropy.",1310.6117v1
+2014-07-01,Explaining Mercury's Density through Magnetic Erosion,"In protoplanetary disks, dust grains rich in metallic iron can attract each
+other magnetically. If they are magnetized to values near saturation, the
+magnetically induced collision speeds are high enough to knock off the
+non-magnetized, loosely bound silicates. This process enriches the surviving
+portions of the dust grains in metallic iron, which further enhances the
+magnetically mediated collisions. The magnetic enhancement to the collisional
+cross-section between the iron rich dust results in rapid grain growth leading
+to planetesimal formation. While this process of knocking off silicates, which
+we term ""magnetic erosion"", occurs only in a very limited portion of a
+protoplanetary disk, it is a possible explanation for Mercury's
+disproportionately large iron core.",1407.0274v1
+2016-11-14,Magnetization process and magnetocaloric effect of the spin-1/2 XXZ Heisenberg cuboctahedron,"Magnetic properties of the spin-1/2 XXZ Heisenberg cuboctahedron are examined
+using exact numerical diagonalization depending on a relative strength of the
+exchange anisotropy. While the Ising cuboctahedron exhibits in a
+low-temperature magnetization curve only one-third magnetization plateau, the
+XXZ Heisenberg cuboctahedron displays another four intermediate plateaux at
+zero, one-sixth, one-half and two-thirds of the saturation magnetization. The
+novel magnetization plateaux generally extend over a wider range of magnetic
+fields with increasing of a quantum ($xy$) part of the XXZ exchange
+interaction. It is shown that the XXZ Heisenberg cuboctahedron exhibits in a
+vicinity of all magnetization jumps anomalous thermodynamic behavior
+accompanied with an enhanced magnetocaloric effect.",1611.04301v1
+2005-06-15,Saturated Ferromagnetism from Statistical Transmutation in Two Dimensions,"The total spin of the ground state is calculated in the U -> infinity Hubbard
+model with uniform magnetic flux perpendicular to a square lattice, in the
+absence of Zeeman coupling. It is found that the saturated ferromagnetism
+emerges in a rather wide region in the space of the flux density \phi and the
+electron density n_e. In particular, the saturated ferromagnetism at \phi = n_e
+is induced by the formation of a spin-1/2 boson, which is a composite of an
+electron and the unit flux quantum.",0506352v3
+2015-10-08,Nematic ordering in pyrochlore antiferromagnets: high-field phase of chromium spinel oxides,"Motivated by recent observation of a new high field phase near saturation in
+chromium spinels $A$Cr$_2$O$_4$ ($A=$ Zn, Cd, Hg), we study the $S = 3/2$
+pyrochlore Heisenberg antiferromagnet with biquadratic interactions. Magnon
+instability analysis at the saturation field reveals that a very small
+biquadratic interaction can induce magnon pairing in pyrochlore
+antiferromagnets, which leads to the emergence of a ferro-quadrupolar phase, or
+equivalently a spin nematic phase, below the saturation field. We present the
+magnetic phase diagram in an applied field, studying both $S=3/2$ and $S=1$
+spin systems. The relevance of our result to chromium spinels is discussed.",1510.02373v1
+2010-09-13,Can conduction induce convection? The non-linear saturation of buoyancy instabilities in dilute plasmas,"We study the effects of anisotropic thermal conduction on low-collisionality,
+astrophysical plasmas using two and three-dimensional magnetohydrodynamic
+simulations. For weak magnetic fields, dilute plasmas are buoyantly unstable
+for either sign of the temperature gradient: the heat-flux-driven buoyancy
+instability (HBI) operates when the temperature increases with radius while the
+magnetothermal instability (MTI) operates in the opposite limit. In contrast to
+previous results, we show that, in the presence of a sustained temperature
+gradient, the MTI drives strong turbulence and operates as an efficient
+magnetic dynamo (akin to standard, adiabatic convection). Together, the
+turbulent and magnetic energies contribute up to ~10% of the pressure support
+in the plasma. In addition, the MTI drives a large convective heat flux, ~1.5%
+of rho c_s^3. These findings are robust even in the presence of an external
+source of strong turbulence. Our results on the nonlinear saturation of the HBI
+are consistent with previous studies but we explain physically why the HBI
+saturates quiescently by re-orienting the magnetic field (suppressing the
+conductive heat flux through the plasma), while the MTI saturates by generating
+sustained turbulence. We also systematically study how an external source of
+turbulence affects the saturation of the HBI: such turbulence can disrupt the
+HBI only on scales where the shearing rate of the turbulence is faster than the
+growth rate of the HBI. In particular, our results provide a simple mapping
+between the level of turbulence in a plasma and the effective isotropic thermal
+conductivity. We discuss the astrophysical implications of these findings, with
+a particular focus on the intracluster medium of galaxy clusters.",1009.2498v1
+2004-09-08,Dynamo action in late-type giants,"Recent numerical MHD simulations suggest that magnetic activity may occur in
+late-type giants. A entire red supergiant with stellar parameters equal to
+Betelgeuse was modelled in 3d with the high-order ""Pencil Code"". Linear
+kinematic and non-linear saturated dynamo action are found and the non-linear
+magnetic field saturates at a super-equipartition value, while in the linear
+regime two different modes of dynamo action are found. Magnetic activity of
+late-type giants, if it exists, may influence dust and wind formation and
+possibly lead to the heating of the outer atmospheres of these stars.",0409192v1
+2004-06-07,Spin switch and spin amplifier: magnetic bipolar transistor in the saturation regime,"It is shown that magnetic bipolar transistors (MBT) can amplify currents even
+in the saturation regime, in which both the emitter-base and collector-base
+junctions are forward biased. The collector current and the current gain can
+change sign as they depend on the relative orientation of the equilibrium spin
+in the base and on the nonequilibrium spin in the emitter and collector. The
+predicted phenomena should be useful for electrical detection of nonequilibrium
+spins in semiconductors, as well as for magnetic control of current
+amplification and for current switching.",0406170v1
+2010-01-24,Stability problem in dynamo,"It is shown, that the saturated $\alpha$-effect taken from the nonlinear
+dynamo equations for the thin disk can still produce exponentially growing
+magnetic field in the case, when this field does not feed back on the $\alpha$.
+For negative dynamo number (stationary regime) stability is defined by the
+structure of the spectra of the linear problem for the positive dynamo numbers.
+Stability condition for the oscillatory solution (positive dynamo number) is
+also obtained and related to the phase shift of the original magnetic field,
+which produced saturated $\alpha$ and magnetic field in the kinematic regime.
+Results can be used for explanation of the similar effect observed in the shell
+models simulations as well in the 3D dynamo models in the plane layer and
+sphere.",1001.4234v1
+2011-01-25,Onset and saturation of ion heating by odd-parity rotating-magnetic-fields in a field-reversed configuration,"Heating of figure-8 ions by odd-parity rotating magnetic fields ($RMF_o$)
+applied to an elongated field-reversed configuration (FRC) is investigated. The
+largest energy gain occurs at resonances ($s \equiv \omega_R/ \omega$) of the
+$RMF_o$ frequency, $\omega_R$, with the figure-8 orbital frequency, $\omega$,
+and is proportional to $s^2$ for $s-even$ resonances and to $s$ for $s-odd$
+resonances. The threshold for the transition from regular to stochastic orbits
+explains both the onset and saturation of heating. The FRC magnetic geometry
+lowers the threshold for heating below that in the tokamak by an order of
+magnitude.",1101.4774v1
+2011-04-11,Hydrogen mediated ferromagnetism in ZnO single crystals,"We investigated the magnetic properties of hydrogen plasma treated ZnO single
+crystals by SQUID magnetometry. In agreement with the expected hydrogen
+penetration depth we found ferromagnetic behavior located at the first 20 nm of
+the H-treated surface of ZnO with magnetization at saturation up to 6 emu/g at
+300 K and Curie temperature T$_c$ $\gtrsim $ 400 K. In the ferromagnetic
+samples a hydrogen concentration of a few atomic percent in the first 20 nm
+surface layer was determined by nuclear reaction analysis. The saturation
+magnetization of H-treated ZnO increases with the concentration of hydrogen.",1104.1899v1
+2011-06-06,Rise and fall of defect induced ferromagnetism in SiC single crystals,"6H-SiC (silicon carbide) single crystals containing VSi-VC divacancies are
+investigated with respect to magnetic and structural properties. We found that
+an initial increase of structural disorder leads to pronounced ferromagnetic
+properties at room temperature. Further introduction of disorder lowers the
+saturation magnetization and is accompanied with the onset of lattice
+amorphization. Close to the threshold of full amorphization, also divacancy
+clusters are formed and the saturation magnetization nearly drops to zero.",1106.0966v1
+2019-10-09,Scattering of exchange spin waves from regions of modulated magnetization,"We investigate the reflection coefficient of spin waves propagating in an
+ultra-thin ferromagnetic film with regions where saturation magnetization is
+modulated. We find analytically and using micromagnetic simulations that there
+are transmission resonances that depend on the width of the regions and on the
+energy of excitation. Our results resemble the quantum mechanical
+Ramsauer-Townsend effect in which an electron with certain energies can
+propagate above a potential field without scattering. Our findings are useful
+for reconfigurable magnonic devices where the saturation magnetization can be
+dynamically controlled via a thermal landscape.",1910.04303v1
+2012-03-09,Exchange-dependent relaxation in the rotating frame for slow and intermediate exchange - modeling off-resonant spin-lock and chemical exchange saturation transfer,"Chemical exchange observed by NMR saturation transfer (CEST) and spin-lock
+(SL) experiments provide an MRI contrast by indirect detection of exchanging
+protons. The determination of the relative concentrations and exchange rates is
+commonly achieved by numerical integration of the Bloch-McConnell equations. We
+derive an analytical solution of the Bloch-McConnell equations that describes
+the magnetization of coupled spin populations under radiofrequency
+irradiation.As CEST and off-resonant SL are equivalent, their steady-state
+magnetization and dynamics can be predicted by the same single eigenvalue: the
+longitudinal relaxation rate in the rotating frame R1rho. For the case of
+slowly exchanging systems, e.g. amide protons, the saturation of the small
+proton pool is affected by transverse relaxation (R2b). It turns out, that R2b
+is also significant for intermediate exchange, such as amine- or
+hydroxyl-exchange or paramagnetic CEST agents, if pools are only partially
+saturated. We propose a solution for R1rho that includes R2 of the exchanging
+pool by extending existing approaches, and verify it by numerical simulations.
+With the appropriate projection factors, we obtain an analytical solution for
+CEST and SL for nonzero R2 of the exchanging pool, whilst considering the
+dilution by direct water saturation across the entire Z-spectra. This allows
+the optimization of irradiation parameters and the quantification of
+pH-dependent exchange rates and metabolite concentrations. In addition, we
+propose evaluation methods that correct for concomitant direct saturation
+effects. It is shown that existing theoretical treatments for CEST are special
+cases of this approach.",1203.2067v2
+2003-12-01,Simulations of small-scale turbulent dynamo,"We report an extensive numerical study of the small-scale turbulent dynamo at
+large magnetic Prandtl numbers Pm. A Pm scan is given for the model case of
+low-Reynolds-number turbulence. We concentrate on three topics: magnetic-energy
+spectra and saturation levels, the structure of the field lines, and the
+field-strength distribution. The main results are (1) the folded structure
+(direction reversals at the resistive scale, field lines curved at the scale of
+the flow) persists from the kinematic to the nonlinear regime; (2) the field
+distribution is self-similar and appears to be lognormal during the kinematic
+regime and exponential in the saturated state; and (3) the bulk of the magnetic
+energy is at the resistive scale in the kinematic regime and remains there
+after saturation, although the spectrum becomes much shallower. We propose an
+analytical model of saturation based on the idea of partial
+two-dimensionalization of the velocity gradients with respect to the local
+direction of the magnetic folds. The model-predicted spectra are in excellent
+agreement with numerical results. Comparisons with large-Re, moderate-Pm runs
+are carried out to confirm the relevance of these results. New features at
+large Re are elongation of the folds in the nonlinear regime from the viscous
+scale to the box scale and the presence of an intermediate nonlinear stage of
+slower-than-exponential magnetic-energy growth accompanied by an increase of
+the resistive scale and partial suppression of the kinetic-energy spectrum in
+the inertial range. Numerical results for the saturated state do not support
+scale-by-scale equipartition between magnetic and kinetic energies, with a
+definite excess of magnetic energy at small scales. A physical picture of the
+saturated state is proposed.",0312046v3
+1995-08-14,BPS Saturated and Non-Extreme States in Abelian Kaluza-Klein Theory and Effective N=4 Supersymmetric String Vacua,"We summarize results for all four-dimensional Bogomol'nyi-Sommerfield-Prasat
+(BPS) saturated and non-extreme solutions of the ($4+n$)-dimensional Abelian
+Kaluza-Klein theory. Within effective N=4 supersymmetric string vacua,
+parameterized in terms of fields of the heterotic string on a six-torus, we
+then present a class of BPS saturated states and the corresponding non-extreme
+solutions, specified by $O(6,22,Z)$ and $SL(2,Z)$ orbits of general dyonic
+charge configurations with zero axion. The BPS saturated states with
+non-negative $O(6,22,Z)$ norms for electric and magnetic charge vectors, along
+with the corresponding set of non-extreme solutions, are regular with non-zero
+masses. BPS saturated states with the negative charge norms are singular,
+unaccompanied by non-extreme solutions and become massless at particular points
+of the moduli space. The role that such massless states may play in the
+enhancement of non-Abelian gauge symmetry as well as local supersymmetry is
+addressed.",9508058v1
+2019-11-09,Tangency property and prior-saturation points in minimal time problems in the plane,"In this paper, we consider minimal time problems governed by
+control-affine-systems in the plane, and we focus on the synthesis problem in
+presence of a singular locus that involves a saturation point for the singular
+control. After giving sufficient conditions on the data ensuring occurence of a
+prior-saturation point and a switching curve, we show that the bridge (i.e.,
+the optimal bang arc issued from the singular locus at this point) is tangent
+to the switching curve at the prior-saturation point. This property is proved
+using the Pontryagin Maximum Principle that also provides a set of non-linear
+equations that can be used to compute the prior-saturation point. These issues
+are illustrated on a fed-batch model in bioprocesses and on a Magnetic
+Resonance Imaging (MRI) model for which minimal time syntheses for the
+point-to-point problem are discussed.",1911.03652v2
+2023-08-17,Comparison of saturation rules used for gyrokinetic quasilinear transport modeling,"Theory-based transport modeling has been widely successful and is built on
+the foundations of quasilinear theory. Specifically, the quasilinear expression
+of the flux can be used in combination with a saturation rule for the toroidal
+mode amplitude. Most transport models follow this approach. Saturation rules
+are heuristic and difficult to rigorously derive. We compare three common
+saturation rules using a fairly accurate quasilinear expression for the fluxes
+computed using local linear gyrokinetic simulation. We take plasma parameters
+from experimental H-mode profiles and magnetic equilibrium and include
+electrons, Deuterium, and Carbon species. We find that the various saturation
+rules give qualitatively similar behavior. This may help explain why the
+different theory-based transport models can all predict core tokamak profiles
+reasonably well. Comparisons with nonlinear local and global gyrokinetic
+simulations are also discussed.",2308.09181v1
+2001-10-05,Saturation and Thermalization of the Magnetorotational Instability: Recurrent Channel Flows and Reconnections,"The nonlinear evolution and the saturation mechanism of the magnetorotational
+instability (MRI) are investigated using three-dimensional resistive MHD
+simulations. A local shearing box is used for our numerical analysis and the
+simulations begin with a purely vertical magnetic field. We find that the
+magnetic stress in the nonlinear stage of the MRI is strongly fluctuating. The
+time evolution shows the quasi-periodic recurrence of spike-shape variations
+typically for a few orbits which correspond to the rapid amplification of the
+magnetic field by the nonlinear growth of a two-channel solution followed by
+the decay through magnetic reconnections. The increase rate of the total energy
+in the shearing box system is analytically related to the volume-averaged
+torque in the system. We find that at the saturated state this energy gain of
+the system is balanced with the increase of the thermal energy mostly due to
+the joule heating. The spike-shape time evolution is a general feature of the
+nonlinear evolution of the MRI in the disks threaded by vertical fields and can
+be seen if the effective magnetic Reynolds number is larger than about unity.",0110125v1
+2007-09-28,Electron coherence at low temperatures: The role of magnetic impurities,"We review recent experimental progress on the saturation problem in metallic
+quantum wires. In particular, we address the influence of magnetic impurities
+on the electron phase coherence time. We also present new measurements of the
+phase coherence time in ultra-clean gold and silver wires and analyse the
+saturation of \tauphi in these samples, cognizant of the role of magnetic
+scattering. For the cleanest samples, Kondo temperatures below 1 mK and
+extremely-small magnetic-impurity concentration levels of less than 0.08 ppm
+have to be assumed to attribute the observed saturation to the presence of
+magnetic impurities.",0709.4663v1
+2010-04-24,Domain structure of bulk ferromagnetic crystals in applied fields near saturation,"We investigate the ground state of a uniaxial ferromagnetic plate with
+perpendicular easy axis and subject to an applied magnetic field normal to the
+plate. Our interest is the asymptotic behavior of the energy in macroscopically
+large samples near the saturation field. We establish the scaling of the
+critical value of the applied field strength below saturation at which the
+ground state changes from the uniform to a branched domain magnetization
+pattern and the leading order scaling behavior of the minimal energy.
+Furthermore, we derive a reduced sharp-interface energy giving the precise
+asymptotic behavior of the minimal energy in macroscopically large plates under
+a physically reasonable assumption of small deviations of the magnetization
+from the easy axis away from domain walls. On the basis of the reduced energy,
+and by a formal asymptotic analysis near the transition, we derive the precise
+asymptotic values of the critical field strength at which non-trivial
+minimizers (either local or global) emerge. The non-trivial minimal energy
+scaling is achieved by magnetization patterns consisting of long slender
+needle-like domains of magnetization opposing the applied field",1004.4292v1
+2011-03-05,Transmission of Excitations in a Spin-1 Bose-Einstein Condensate through a Barrier,"We investigate tunneling of excitations across a potential barrier separating
+two spin-1 Bose-Einstein condensates. Using the mean-field theory at the
+absolute zero temperature, we determine transmission coefficients of
+excitations in the saturated magnetization state and unsaturated magnetization
+states. All excitations except the quadrupolar spin mode in the saturated
+magnetization state show the anomalous tunneling phenomenon characterized as
+perfect tunneling in the low momentum limit through a potential barrier. The
+quadrupolar spin mode in the saturated magnetization state, whose spectrum is
+massive, shows total reflection. We discuss properties common between
+excitations showing the anomalous tunneling phenomenon. Excitations showing
+perfect tunneling have gapless spectrum in the absence of the magnetic field,
+and their wave functions in the low energy limit are the same as the condensate
+wave function.",1103.1004v2
+2014-08-20,Anomalous Behavior of the Magnetization Process of the S = 1/2 Kagome-Lattice Heisenberg Antiferromagnet at One-Third Height of the Saturation,"The magnetization process of the S=1/2 Heisenberg antiferromagnet on the
+kagome lattice is studied by the numerical-diagonalization method. We
+successfully obtain a new result of the magnetization process of a 42-site
+cluster in the entire range. Our analysis clarifies that the critical behavior
+around one-third of the height of the saturation is different from the typical
+behavior of the well-known magnetization plateau in two-dimensional systems. We
+also examine the effect of the $\sqrt{3}\times\sqrt{3}$-type distortion added
+to the kagome lattice. We find at one-third of the height of the saturation in
+the magnetization process that the undistorted kagome point is just the
+boundary between two phases that show their own properties that are different
+from each other. Our results suggest a relationship between the anomalous
+critical behavior at the undistorted point and the fact that the undistorted
+point is the boundary.",1408.4538v1
+2019-01-04,How to accurately determine a saturation magnetization of the sample in a ferromagnetic resonance experiment?,"The phenomenon of ferromagnetic resonance (FMR) is still being exploited for
+determining the magnetocrystalline anisotropy constants of magnetic materials.
+We show that one can also determine accurately the saturation magnetization of
+the sample using results of FMR experiments after taking into account the
+relationship between resonance frequency and curvature of the spatial
+distribution of free energy at resonance. Specifically, three examples are
+given of calculating saturation magnetization from FMR data: we use historical
+Bickford's measurements from 1950 for bulk magnetite, Liu's measurements from
+2007 for a 500 mn thin film of a weak ferromagnet (Ga, Mn)As, and Wang's
+measurements from 2014 for an ultrathin film of YIG. In all three cases, the
+magnetization values we have determined are consistent with the results of
+measurements.",1901.01207v1
+2021-08-19,Saturation of large-scale dynamo in anisotropically forced turbulence,"Turbulent dynamo theories have faced difficulties in obtaining evolution of
+large-scale magnetic fields on short dynamical time-scales due to the
+constraint imposed by magnetic helicity balance. This has critical implications
+for understanding the large-scale magnetic field evolution in astrophysical
+systems like the Sun, stars and galaxies. Direct numerical simulations (DNS) in
+the past with isotropically forced helical turbulence have shown that
+large-scale dynamo saturation time-scales are dependent on the magnetic
+Reynolds number (Rm). In this work, we have carried out periodic box DNS of
+helically forced turbulence leading to a large-scale dynamo with two kinds of
+forcing function, an isotropic one based on that used in PENCIL-CODE and an
+anisotropic one based on Galloway-Proctor flows. We show that when the
+turbulence is forced anisotropically, the nonlinear (saturation) behaviour of
+the large-scale dynamo is only weakly dependent on Rm. In fact the magnetic
+helicity evolution on small and large scales in the anisotropic case is
+distinctly different from that in the isotropic case. This result possibly
+holds promise for the alleviation of important issues like catastrophic
+quenching.",2108.08740v2
+2007-07-24,Magnetic braking in young late-type stars: the effect of polar spots,"The concentration of magnetic flux near the poles of rapidly rotating cool
+stars has been recently proposed as an alternative mechanism to dynamo
+saturation in order to explain the saturation of angular momentum loss. In this
+work we study the effect of magnetic surface flux distribution on the coronal
+field topology and angular momentum loss rate. We investigate if magnetic flux
+concentration towards the pole is a reasonable alternative to dynamo
+saturation. We construct a 1D wind model and also apply a 2-D self-similar
+analytical model, to evaluate how the surface field distribution affects the
+angular momentum loss of the rotating star. From the 1D model we find that, in
+a magnetically dominated low corona, the concentrated polar surface field
+rapidly expands to regions of low magnetic pressure resulting in a coronal
+field with small latitudinal variation. We also find that the angular momentum
+loss rate due to a uniform field or a concentrated field with equal total
+magnetic flux is very similar. From the 2D wind model we show that there are
+several relevant factors to take into account when studying the angular
+momentum loss from a star. In particular, we show that the inclusion of force
+balance across the field in a wind model is fundamental if realistic
+conclusions are to be drawn from the effect of non-uniform surface field
+distribution on magnetic braking. This model predicts that a magnetic field
+concentrated at high latitudes leads to larger Alfven radii and larger braking
+rates than a smoother field distribution. From the results obtained, we argue
+that the magnetic surface field distribution towards the pole does not directly
+limit the braking efficiency of the wind.",0707.3588v1
+2010-05-28,Magnetic helicity fluxes in interface and flux transport dynamos,"Dynamos in the Sun and other bodies tend to produce magnetic fields that
+possess magnetic helicity of opposite sign at large and small scales,
+respectively. The build-up of magnetic helicity at small scales provides an
+important saturation mechanism. In order to understand the nature of the solar
+dynamo we need to understand the details of the saturation mechanism in
+spherical geometry. In particular, we want to understand the effects of
+magnetic helicity fluxes from turbulence and meridional circulation. We
+consider a model with just radial shear confined to a thin layer (tachocline)
+at the bottom of the convection zone. The kinetic alpha owing to helical
+turbulence is assumed to be localized in a region above the convection zone.
+The dynamical quenching formalism is used to describe the build-up of mean
+magnetic helicity in the model, which results in a magnetic alpha effect that
+feeds back on the kinetic alpha effect. In some cases we compare with results
+obtained using a simple algebraic alpha quenching formula. In agreement with
+earlier findings, the magnetic alpha effect in the dynamical alpha quenching
+formalism has the opposite sign compared with the kinetic alpha effect and
+leads to a catastrophic decrease of the saturation field strength with
+increasing magnetic Reynolds numbers. However, at high latitudes this quenching
+effect can lead to secondary dynamo waves that propagate poleward due to the
+opposite sign of alpha. Magnetic helicity fluxes both from turbulent mixing and
+from meridional circulation alleviate catastrophic quenching.",1005.5335v1
+2017-09-27,Magnetic properties of optimized cobalt nanospheres grown by Focused Electron Beam Induced Deposition (FEBID) on cantilever tips,"In this work, we present a detailed investigation of the magnetic properties
+of cobalt nanospheres grown on cantilever tips by Focused Electron Beam Induced
+Deposition (FEBID). The cantilevers are extremely soft and the cobalt
+nanospheres are optimized for Magnetic Resonance Force Microscopy (MRFM)
+experiments, which implies that the cobalt nanospheres must be as small as
+possible while bearing high saturation magnetization. It is found that the
+cobalt content and the corresponding saturation magnetization of the
+nanospheres decrease for nanosphere diameters below 300 nm. Electron holography
+measurements show the formation of a magnetic vortex state in remanence, which
+nicely agrees with magnetic hysteresis loops performed by local magnetometry
+showing negligible remanent magnetization. As investigated by local
+magnetometry, optimal behavior for high-resolution MRFM has been found for
+cobalt nanospheres with diameter of $\approx$ 200 nm, which present atomic
+cobalt content of $\approx$ 83 at% and saturation magnetization of 106 A/m,
+around 70% of the bulk value. These results represent the first comprehensive
+investigation of the magnetic properties of cobalt nanospheres grown by FEBID
+for application in MRFM.",1709.09374v1
+2010-11-01,Quantitative magnetic force microscopy on permalloy dots using an iron filled carbon nanotube probe,"We have characterized a new Magnetic Force Microscopy (MFM) probe based on an
+iron filled carbon nanotube (FeCNT) using MFM imaging on permalloy (Py) disks
+saturated in a high magnetic field perpendicular to the disk plane. The
+experimental data are accurately modeled by describing the FeCNT probe as
+having a single magnetic monopole at its tip whose effective magnetic charge is
+determined by the diameter of the iron wire enclosed in the carbon nanotube and
+its saturation magnetization 4 \pi M_s ~ 2.2 x 10^4 G. A magnetic monopole
+probe enables quantitative measurements of the magnetic field gradient close to
+the sample surface. The lateral resolution is defined by the diameter of the
+iron wire ~15 nm and the probe-sample separation. As a demonstration, the
+magnetic field gradients close to the surface of a Py dot in domain and vortex
+states were imaged.",1011.0389v1
+2015-12-02,Field-driven successive phase transitions in quasi-two-dimensional frustrated antiferromagnet Ba$_2$CoTeO$_6$ and highly degenerate classical ground states,"We report the results of magnetization and specific heat measurements of
+Ba$_2$CoTeO$_6$ composed of two subsystems A and B, which are magnetically
+described as an $S\,{=}\,1/2$ triangular-lattice Heisenberg-like
+antiferromagnet and a $J_1-J_2$ honeycomb-lattice Ising-like antiferromagnet,
+respectively. These two subsystems were found to be approximately decoupled.
+Ba$_2$CoTeO$_6$ undergoes magnetic phase transitions at $T_{\rm N1}\,{=}\,12.0$
+K and $T_{\rm N2}\,{=}\,3.0$ K, which can be interpreted as the orderings of
+subsystems B and A, respectively. Subsystem A exhibits a magnetization plateau
+at one-third of the saturation magnetization for the magnetic field $H$
+perpendicular to the $c$ axis owing to the quantum order-by-disorder, whereas
+for $H\,{\parallel}\,c$, subsystem B shows three-step metamagnetic transitions
+with magnetization plateaus at zero, one-third and one-half of the saturation
+magnetization. The analysis of the magnetization process for subsystem B shows
+that the classical ground states at these plateaus are infinitely degenerate
+within the Ising model.",1512.00693v1
+2017-02-15,Hot magnetized nuclear matter: Thermodynamic and Saturation Properties,"We have used a realistic nuclear potential, AV18, and a many body technique,
+the lowest order constraint variational (LOCV) approach, to calculate the
+properties of hot magnetized nuclear matter. By investigating the free energy,
+spin polarization parameter, and symmetry energy, we have studied the
+temperature and magnetic field dependence of the saturation properties of
+magnetized nuclear matter. In addition, we have calculated the equation of
+state of magnetized nuclear matter at different temperatures and magnetic
+fields. It was found that the flashing temperature of nuclear matter decreases
+by increasing the magnetic field. In addition, we have studied the effect of
+the magnetic field on liquid gas phase transition of nuclear matter. The liquid
+gas coexistence curves, the order parameter of the liquid gas phase transition,
+and the properties of critical point at different magnetic fields have been
+calculated.",1702.04765v1
+2019-09-28,Size-Dependent Structural and Magnetic Properties of Disordered Co2FeAl Heusler Alloy Nanoparticles,"Co2FeAl (CFA) nanoparticles (NPs) of different sizes were synthesized by
+chemical route. The effect of the size of NPs upon the structure and
+magnetization compared to its bulk counterpart was investigated. The structure
+and composition were determined from X-ray diffraction (XRD) and electron
+microscopy. XRD analysis shows that the samples are having single (A2-type)
+disordered phase. Magnetization measurements suggest that the samples are soft
+ferromagnetic in nature with very low coercivity. Enhanced magnetic properties
+like saturation magnetization, coercive force, retentivity, and
+Curie-temperature are observed with a decrease in particle size. The effect of
+particle size on hysteresis losses is also discussed. The smallest particles of
+size 16 nm exhibited the highest saturation magnetization and transition
+temperature of 180.73 emu/g and 1261 K, respectively. The origin of enhancement
+in the magnetization of Co2FeAl nano-alloy is attributed to the strong Co-Co
+exchange interaction due to disorder present in the systems.",1909.13088v1
+2010-02-08,The nonlinear saturation of the non-resonant kinetically driven streaming instability,"A non-resonant instability for the amplification of the interstellar magnetic
+field in young Supernova Remnant (SNR) shocks was predicted by Bell (2004), and
+is thought to be relevant for the acceleration of cosmic ray (CR) particles.
+For this instability, the CRs streaming ahead of SNR shock fronts drive
+electromagnetic waves with wavelengths much shorter than the typical CR Larmor
+radius, by inducing a current parallel to the background magnetic field. We
+explore the nonlinear regime of the non-resonant mode using Particle-in-Cell
+(PIC) hybrid simulations, with kinetic ions and fluid electrons, and analyze
+the saturation mechanism for realistic CR and background plasma parameters. In
+the linear regime, the observed growth rates and wavelengths match the
+theoretical predictions; the nonlinear stage of the instability shows a strong
+reaction of both the background plasma and the CR particles, with the
+saturation level of the magnetic field varying with the CR parameters. The
+simulations with CR-to-background density ratios of n_CR/n_b=10^(-5) reveal the
+highest magnetic field saturation levels, with energy also being transferred to
+the background plasma and to the perpendicular velocity components of the CR
+particles. The results show that amplification factors >10 for the magnetic
+field can be achieved, and suggest that this instability is important for the
+generation of magnetic field turbulence, and for the acceleration of CR
+particles.",1002.1701v1
+2018-10-22,Nonlinear Evolution of the Resonant Drag Instability in Magnetized Gas,"We investigate, for the first time, the nonlinear evolution of the magnetized
+""resonant drag instabilities"" (RDIs). We explore magnetohydrodynamic (MHD)
+simulations of gas mixed with (uniform) dust grains subject to Lorentz and drag
+forces, using the GIZMO code. The magnetized RDIs exhibit fundamentally
+different behaviour than the purely acoustic RDIs. The dust organizes into
+coherent structures and the system exhibits strong dust-gas separation. In the
+linear and early nonlinear regime, the growth rates agree with linear theory
+and the dust self-organizes into two-dimensional planes or ""sheets."" Eventually
+the gas develops fully nonlinear, saturated Alfv\'enic and compressible
+fast-mode turbulence, which fills the under-dense regions with a small amount
+of dust, and drives a dynamo which saturates at equipartition of kinetic and
+magnetic energy. The dust density fluctuations exhibit significant
+non-Gaussianity, and the power spectrum is strongly weighted towards the
+largest (box-scale) modes. The saturation level can be understood via
+quasi-linear theory, as the forcing and energy input via the instabilities
+becomes comparable to saturated tension forces and dissipation in turbulence.
+The magnetized simulation presented here is just one case; it is likely that
+the magnetic RDIs can take many forms in different parts of parameter space.",1810.09491v1
+2022-09-16,Unveiling new quantum phases in the Shastry-Sutherland compound SrCu2(BO3)2up to the saturation magnetic field,"Under magnetic fields, quantum magnets often undergo exotic phase transitions
+with various kinds of order. The discovery of a sequence of fractional
+magnetization plateaus in the Shastry-Sutherland compound SrCu2(BO3)2 has
+played a central role in the high-field research on quantum materials, but so
+far this system could only be probed up to half the saturation value of the
+magnetization. Here, we report the first experimental and theoretical
+investigation of this compound up to the saturation magnetic field of 140 T and
+beyond. Using ultrasound and magnetostriction techniques combined with
+extensive tensor-network calculations (iPEPS), several spin-supersolid phases
+are revealed between the 1/2 plateau and saturation (1/1 plateau). Quite
+remarkably, the sound velocity of the 1/2 plateau exhibits a drastic decrease
+of -50%, related to the tetragonal-to-orthorhombic instability of the
+checkerboard-type magnon crystal. The unveiled nature of this paradigmatic
+quantum system is a new milestone for exploring exotic quantum states of matter
+emerging in extreme conditions.",2209.07652v2
+2011-08-19,Magnetic field amplification and X-ray emission in galaxy minor mergers,"We investigate the magnetic field evolution in a series of galaxy minor
+mergers using the N-body/smoothed particle hydrodynamics (SPH) code
+\textsc{Gadget}. The simulations include the effects of radiative cooling, star
+formation and supernova feedback. Magnetohydrodynamics (MHD) is implemented
+using the SPH method. We present 32 simulations of binary mergers of disc
+galaxies with mass ratios of 2:1 up to 100:1, whereby we have additionally
+varied the initial magnetic field strengths, disc orientations and resolutions.
+We investigate the amplification of a given initial magnetic field within the
+galaxies and an ambient intergalactic medium (IGM) during the interaction. We
+find that the magnetic field strengths of merger remnants with mass ratios up
+to 10:1 saturate at a common value of several $\mu$G. For higher mass ratios,
+the field strength saturates at lower values. The saturation values correspond
+to the equipartition value of magnetic and turbulent energy density. The
+initial magnetization, disc orientation and numerical resolution show only
+minor effects on the saturation value of the magnetic field. We demonstrate
+that a higher impact energy of the progenitor galaxies leads to a more
+efficient magnetic field amplification. The magnetic and turbulent energy
+densities are higher for larger companion galaxies, consistent with the higher
+impact energy supplied to the system. We present a detailed study of the
+evolution of the temperature and the bolometric X-ray luminosity within the
+merging systems. Thereby we find that magnetic fields cause a more efficient
+increase of the IGM temperature and the corresponding IGM X-ray luminosity
+after the first encounter. However, the presence of magnetic fields does not
+enhance the total X-ray luminosity. Generally, the final value of the X-ray
+luminosity is even clearly lower for higher initial magnetic fields.",1108.4006v1
+2004-11-17,Magnetic helicity and cosmological magnetic field,"The magnetic helicity has paramount significance in nonlinear saturation of
+galactic dynamo. We argue that the magnetic helicity conservation is violated
+at the lepton stage in the evolution of early Universe. As a result, a
+cosmological magnetic field which can be a seed for the galactic dynamo obtains
+from the beginning a substantial magnetic helicity which has to be taken into
+account in the magnetic helicity balance at the later stage of galactic dynamo.",0411496v3
+1999-07-19,Doping Induced Magnetization Plateaus,"The low temperature magnetization process of antiferromagnetic spin-S chains
+doped with mobile spin-(S-1/2) carriers is studied in an exactly solvable
+model. For sufficiently high magnetic fields the system is in a metallic phase
+with a finite gap for magnetic excitations. In this phase which exists for a
+large range of carrier concentrations x the zero temperature magnetization is
+determined by x alone. This leads to plateaus in the magnetization curve at a
+tunable fraction of the saturation magnetization. The critical behaviour at the
+edges of these plateaus is studied in detail.",9907258v1
+2001-02-02,Singlet Ground State and Magnetization Plateaus in Ba$_3$Mn$_2$O$_8$,"Magnetic susceptibility and the magnetization process have been measured in
+\green polycrystal. In this compound, the magnetic manganese ion exists as
+Mn$^{5+}$ in a tetrahedral environment, and thus the magnetic interaction can
+be described by an S=1 Heisenberg model. The ground state was found to be a
+spin singlet with an excitation gap $\Delta/k_{\rm B}=11.2$ K. Magnetization
+plateaus were observed at zero and at half of the saturation magnetization.
+These results indicate that the present system can be represented by a coupled
+antiferromagnetic dimer model.",0102026v2
+2000-05-01,Magnetic Fractal Dimensionality of the Dielectric Breakdown Under Strong Magnetic Fields,"The formation of breakdown pattern on an insulating surface under the
+influence of a transverse magnetic field is theoretically investigated. We have
+generalized the Dielectric Breakdown Model (DBM) for the case of external
+magnetic field. Concept of the Magnetic Fractal Dimensionality (MFD) is
+introduced and its universality is demonstrated. It is shown that MFD saturates
+with magnetic fields. The magnetic field dependence of the streamer curvature
+is obtained. It is conjectured that nonlinear current interaction is
+responsible for the experimentally observed 'spider-legs' like streamer
+patterns.",0005002v1
+2011-03-02,Magnetic structure of azurite above the 1/3 magnetization plateau,"The transition from the 1/3 magnetization plateau towards the saturation
+magnetization in azurite has been studied by low-temperature,
+high-magnetic-field, high-frequency proton nuclear magnetic resonance (NMR).
+The observed symmetrical splitting of the NMR spectra is incompatible with the
+longitudinal incommensurate order appearing when the longitudinal correlation
+function becomes dominant over the transverse one, which is the expected
+framework for the existence of the 2/3 magnetization plateau. The spectra are
+rather interpreted in terms of a more standard transverse antiferromagnetic
+(canted) order.",1103.0376v1
+2018-12-26,Probing the Relationship between Anisotropic Magnetoresistance and Magnetization of ferromagnetic films,"The anisotropic magnetoresistance (AMR) in thin permalloy strips was
+calculated at each steps during magnetization by the finite element method. The
+magnetization at equilibrium under different external fields was obtained by
+micromagnetic simulations, while the resistance with different magnetization
+was obtained by solving the Poisson equations iteratively until
+self-consistence. We find that the relation between magnetization and AMR
+deviates from the Stoner-Wohlfarth prediction when the magnetization is reduced
+from saturation. The reason is that the demagnetization is not necessarily from
+coherent rotation of the magnetic moment. We conclude that it is necessary to
+use numeric simulations to optimize the responses of AMR sensors.",1812.10294v1
+2017-04-19,A small-scale dynamo in feedback-dominated galaxies - II. The saturation phase and the final magnetic configuration,"Magnetic fields in galaxies are believed to be the result of dynamo
+amplification of initially weak seed fields, reaching equipartition strength
+inside the interstellar medium. The small-scale dynamo appears to be a viable
+mechanism to explain observations of strong magnetic fields in present-day and
+high-redshift galaxies, considering the extreme weakness of seed fields
+predicted by battery mechanisms or primordial fields. Performing
+high-resolution adaptive mesh magneto-hydrodynamic simulations of a small mass,
+isolated cooling halo with an initial magnetic seed field strength well below
+equipartition, we follow the small-scale dynamo amplification from
+supernova-induced turbulence up to saturation of the field. We find that
+saturation occurs when the average magnetic pressure reaches only 3 % to 5 % of
+the turbulent pressure. The magnetic energy growth transitions from exponential
+to linear, and finally comes to halt. The saturation level increases slightly
+with grid resolution. These results are in good agreement with theoretical
+predictions for magnetic Prandtl numbers of order $\mathrm{Pr_M} \sim 1$ and
+turbulent Mach numbers of order $\mathrm{M} \sim 10$. When we suppress
+supernova feedback after our simulation has reached saturation, we find that
+turbulence decays and that the gas falls back onto a thin disk with the
+magnetic field in local equipartition.
+  We propose a scenario in which galactic magnetic fields are amplified from
+weak seed fields in the early stages of the Universe to sub-equipartition
+fields, owing to the turbulent environment of feedback-dominated galaxies at
+high redshift, and are evolved further in a later stage up to equipartition, as
+galaxies transformed into more quiescent, large spiral disks.",1704.05845v1
+2013-01-08,Magnetic energy cascade in spherical geometry: I. The stellar convective dynamo case,"We present a method to characterize the spectral transfers of magnetic energy
+between scales in simulations of stellar convective dynamos. The full triadic
+transfer functions are computed thanks to analytical coupling relations of
+spherical harmonics based on the Clebsch-Gordan coefficients. The method is
+applied to mean field $\alpha\Omega$ dynamo models as benchmark tests. From the
+physical standpoint, the decomposition of the dynamo field into primary and
+secondary dynamo families proves very instructive in the $\alpha\Omega$ case.
+The same method is then applied to a fully turbulent dynamo in a solar
+convection zone, modeled with the 3D MHD ASH code. The initial growth of the
+magnetic energy spectrum is shown to be non-local. It mainly reproduces the
+kinetic energy spectrum of convection at intermediate scales. During the
+saturation phase, two kinds of direct magnetic energy cascades are observed in
+regions encompassing the smallest scales involved in the simulation. The first
+cascade is obtained through the shearing of magnetic field by the large scale
+differential rotation that effectively cascades magnetic energy. The second is
+a generalized cascade that involves a range of local magnetic and velocity
+scales. Non-local transfers appear to be significant, such that the net
+transfers cannot be reduced to the dynamics of a small set of modes. The
+saturation of the large scale axisymmetric dipole and quadrupole are detailed.
+In particular, the dipole is saturated by a non-local interaction involving the
+most energetic scale of the magnetic energy spectrum, which points out the
+importance of the magnetic Prandtl number for large-scale dynamos.",1301.1606v1
+2018-01-25,Strong dipole magnetic fields in fast rotating fully convective stars,"M dwarfs are the most numerous stars in our Galaxy with masses between
+approximately 0.5 and 0.1 solar mass. Many of them show surface activity
+qualitatively similar to our Sun and generate flares, high X-ray fluxes, and
+large-scale magnetic fields. Such activity is driven by a dynamo powered by the
+convective motions in their interiors. Understanding properties of stellar
+magnetic fields in these stars finds a broad application in astrophysics,
+including, e.g., theory of stellar dynamos and environment conditions around
+planets that may be orbiting these stars. Most stars with convective envelopes
+follow a rotation-activity relationship where various activity indicators
+saturate in stars with rotation periods shorter than a few days. The activity
+gradually declines with rotation rate in stars rotating more slowly. It is
+thought that due to a tight empirical correlation between X-ray and magnetic
+flux, the stellar magnetic fields will also saturate, to values around ~4kG.
+Here we report the detection of magnetic fields above the presumed saturation
+limit in four fully convective M-dwarfs. By combining results from
+spectroscopic and polarimetric studies we explain our findings in terms of
+bistable dynamo models: stars with the strongest magnetic fields are those in a
+dipole dynamo state, while stars in a multipole state cannot generate fields
+stronger than about four kilogauss. Our study provides observational evidence
+that dynamo in fully convective M dwarfs generates magnetic fields that can
+differ not only in the geometry of their large scale component, but also in the
+total magnetic energy.",1801.08571v1
+2004-09-08,On the Saturation of Astrophysical Dynamos: Numerical Experiments with the No-cosines flow,"In the context of astrophysical dynamos we illustrate that the no-cosines
+flow, with zero mean helicity, can drive fast dynamo action and study the
+dynamo's mode of operation during both the linear and non-linear saturation
+regime: It turns out that in addition to a high growth rate in the linear
+regime, the dynamo saturates at a level significantly higher than normal
+turbulent dynamos, namely at exact equipartition when the magnetic Prandtl
+number is on the order of unity. Visualization of the magnetic and velocity
+fields at saturation will help us to understand some of the aspects of the
+non-linear dynamo problem.",0409193v1
+2007-02-28,On the nonlinear saturation of the magnetorotational instability near threshold in a thin-gap Taylor-Couette setup,"We study the saturation near threshold of the axisymmetric magnetorotational
+instability (MRI) of a viscous, resistive, incompressible fluid in a thin-gap
+Taylor-Couette configuration. A vertical magnetic field, Keplerian shear and
+no-slip, conducting radial boundary conditions are adopted. The weakly
+non-linear theory leads to a real Ginzburg-Landau equation for the disturbance
+amplitude, like in our previous idealized analysis. For small magnetic Prandtl
+number (P \ll 1), the saturation amplitude scales as P^{2/3} while the
+magnitude of angular momentum transport scales as P^{4/3}. The difference with
+the previous scalings (~P^{1/2} and P respectively) is attributed to the
+emergence of radial boundary layers. Away from those, steady-state non-linear
+saturation is achieved through a modest reduction in the destabilizing shear.
+These results will be useful to understand MRI laboratory experiments and
+associated numerical simulations.",0702747v2
+2006-10-28,Exact one- and two-particle excitation spectra of acute-angle helimagnets above their saturation magnetic field,"The two-magnon problem for the frustrated XXZ spin-1/2 Heisenberg Hamiltonian
+and external magnetic fields exceeding the saturation field Bs is considered.
+We show that the problem can be exactly mapped onto an effective tight-binding
+impurity problem. It allows to obtain explicit exact expressions for the
+two-magnon Green's functions for arbitrary dimension and number of
+interactions. We apply this theory to a quasi-one dimensional helimagnet with
+ferromagnetic nearest neighbor J1 < 0 and antiferromagnetic next-nearest
+neighbor J2 > 0 interactions. An outstanding feature of the excitation spectrum
+is the existence of two-magnon bound states. This leads to deviations of the
+saturation field Bs from its classical value Bs(classical) which coincides with
+the one-magnon instability. For the refined frustration ratio |J2/J1|> 0.374661
+the minimum of the two-magnon spectrum occurs at the boundary of the Brillouin
+zone. Based on the two-magnon approach, we propose general analytic expressions
+for the saturation field Bs, confirming known previous results for
+one-dimensional isotropic systems, but explore also the role of interchain and
+long-ranged intrachain interactions as well as of the exchange anisotropy.",0610801v1
+2022-03-23,A Kinetic Study of the Saturation of the Bell Instability,"The nonresonant cosmic ray instability, predicted by Bell (2004), is thought
+to play an important role in the acceleration and confinement of cosmic rays
+(CR) close to supernova remnants. Despite its importance, the exact mechanism
+responsible for the saturation of the instability has not been determined, and
+there is no first-principle prediction for the amplitude of the saturated
+magnetic field. Using a survey of self-consistent hybrid simulations (with
+kinetic ions and fluid electrons), we study the non-linear evolution of the
+Bell instability as a function of the parameters of the CR population. We find
+that saturation is achieved when the magnetic pressure in the amplified field
+is comparable to the initial CR momentum flux.",2203.12568v1
+2022-08-31,Modified Froelich's Equation for Modelling of a Three Phase Self-Excited Synchronous Generator,"With advancement in design and analysis of electro-mechanical and
+electromagnetic devices, the modelling of magnetic saturation of a synchronous
+generator has emerged to be a subject of interest in number of publications.
+Most of the existing electrical machine modelling methods does ignore the
+saturation effect for simplicity. On the other hand, who incorporate saturation
+effect, are dealing with complex computation of coefficients which involves
+tedious curve fitting techniques like non-linear regression, least-squares.
+This paper presents the novel method of modelling of the self-excited
+synchronous generator along with magnetizing characteristics with ease and good
+accuracy which is inspired from Froelichs equation. The proposed mathematical
+model is implemented in simulation environment and validated the results with a
+practical three phase self-excited synchronous generator in which saturation
+plays a vital role.",2208.14775v1
+2004-10-22,Magnetostriction in an array of spin chains under magnetic field,"We consider an array of XX spin-1/2 chains coupled to acoustic phonons and
+placed in a magnetic field. Treating the phonons in the mean field
+approximation, we show that this system presents a first order transition as a
+function of the magnetic field between a partially magnetized distorted state
+and the fully polarized undistorted state at low temperature. This behavior
+results from the magnetostriction of the coupled chain system. A dip in the
+elastic constant of the material near the saturation field along with an
+anomaly in the magnetic susceptibility is predicted. We also predict the
+contraction of the material as the magnetic field is reduced (positive
+magnetostriction) and the reciprocal effect i.e. a decrease of magnetization
+under applied pressure. At higher temperature, the first order transition is
+replaced by a crossover. However, the anomalies in the susceptibilities in the
+system near the saturation field are still present. We discuss the relevance of
+our analysis in relation to recent experiments on spin-1/2 chain and ladder
+materials in strong magnetic fields.",0410571v2
+2021-11-09,Oxygen Defect Engineered Magnetism of La2NiMnO6 Thin Films,"The double perovskite La2NiMnO6 (LNMO) exhibits complex magnetism due to the
+competition of magnetic interactions that are strongly affected by structural
+and magnetic inhomogeneities. In this work, we study the effect of oxygen
+annealing on the structure and magnetism of epitaxial thin films grown by
+pulsed laser deposition. The key observations are that a longer annealing time
+leads to a reduction of saturation magnetization and an enhancement in the
+ferromagnetic transition temperature. We explain these results based upon
+epitaxial strain and oxygen defect engineering. The oxygen enrichment by
+annealing caused a decrease in the volume of the perovskite lattice. This
+increased the epitaxial strain of the films that are in-plane locked to the
+SrTiO3 substrate. The enhanced strain caused a reduction in the saturation
+magnetization due to randomly distributed anti-site defects. The reduced oxygen
+defects concentration in the films due to the annealing in oxygen improved the
+ferromagnetic long-range interaction and caused an increase in the magnetic
+transition temperature.",2111.05037v1
+2023-07-03,Magnetic lump motion in saturated ferromagnetic films,"In this paper, we study in detail the nonlinear propagation of magnetic
+soliton in a ferromagnetic film. The sample is magnetized to saturation by an
+external field perpendicular to film plane. A new generalized (2+1)-dimensional
+short-wave asymptotic model is derived. The bilinear-like forms of this
+equation are constructed, and exact magnetic line soliton solutions are
+exhibited. It is observed that a series of stable lumps can be generated by an
+unstable magnetic soliton under Gaussian disturbance. Such magnetic lumps are
+highly stable and can maintain their shapes and velocities during evolution or
+collision. The interaction between lump and magnetic soliton, as well as
+interaction between two lumps, are numerically investigated. We further discuss
+the nonlinear motion of lumps in ferrites with Gilbert-damping and
+inhomogeneous exchange effects. The results show that the Gilbert-damping
+effects make the amplitude and velocity of the magnetic lump decay
+exponentially during propagation. And the shock waves are generated from a lump
+when quenching the strength of inhomogeneous exchange.",2307.00903v1
+2023-07-27,Generation of near-equipartition magnetic fields in turbulent collisionless plasmas,"The mechanisms that generate ""seed"" magnetic fields in our Universe and that
+amplify them throughout cosmic time remain poorly understood. By means of
+fully-kinetic particle-in-cell simulations of turbulent, initially unmagnetized
+plasmas, we study the genesis of magnetic fields via the Weibel instability and
+follow their dynamo growth up to near-equipartition levels. In the kinematic
+stage of the dynamo, we find that the rms magnetic field strength grows
+exponentially with rate $\gamma_B \simeq 0.4\,u_{\rm rms}/L$, where $L/2 \pi$
+is the driving scale and $u_{\rm rms}$ is the rms turbulent velocity. In the
+saturated stage, the magnetic field energy reaches about half of the turbulent
+kinetic energy. Here, magnetic field growth is balanced by dissipation via
+reconnection, as revealed by the appearance of plasmoid chains. At saturation,
+the integral-scale wavenumber of the magnetic spectrum approaches $k_{\rm
+int}\simeq 12\pi/L$. Our results show that turbulence -- induced by, e.g., the
+gravitational build-up of galaxies and galaxy clusters -- can magnetize
+collisionless plasmas with large-scale near-equipartition fields.",2307.15112v1
+2006-10-08,Relaxation oscillations of Zeeman and dipole magnetizations of a paramagnet under conditions of deep low-frequency modulation,"The relaxation oscillations of Zeeman and dipole magnetizaions in spin system
+of a solid paramagnet are theoretically analyzed under conditions of
+intermediate saturation of magnetic resonance and strong low-frequency
+modulation of the external magnetic field. Peculiarities of the relaxation
+oscillations in the synchronous detection regime are considered.",0610211v1
+2021-02-22,Robust skyrmion mediated reversal of ferromagnetic nanodots of 20 nm lateral dimension with high Ms and moderate DMI,"Implementation of skyrmion based energy efficient and high-density data
+storage devices requires aggressive scaling of skyrmion size. Ferrimagnetic
+materials are considered to be a suitable platform for this purpose due to
+their low saturation magnetization (i.e. smaller stray field). However, we show
+by performing rigorous micromagnetic simulation that such scaling of skyrmion
+size by lowering saturation magnetization while applicable in infinite films or
+where the skyrmion size is very small compared to the film's lateral dimension,
+does not hold in confined geometries. We also found in confined geometries,
+where skyrmion occupies the whole volume of a nanodot, high saturation
+magnetization helps form stable skyrmions. Specifically, such skyrmions can be
+formed in 20 nm lateral dimension nanodots with high saturation magnetization
+(1.6-1.71 MA/m) and moderate DMI (3 mJ/m2). This result could stimulate
+experiments on implementation of highly dense skyrmion devices. In particular,
+we show that Voltage Controlled Magnetic Anisotropy (VCMA) based switching
+mediated by an intermediate skyrmion state can be achieved in the soft layer of
+a ferromagnetic p-MTJ of lateral dimensions 20 nm with sub 1fJ/bit energy in
+the presence of room temperature thermal noise with reasonable DMI ~3 mJ/m2.",2102.10721v1
+2006-08-01,Understanding the saturation of proton-driven Weibel instabilities and implications for astrophysics,"The linear growth rate and saturation level of magnetic fields for Weibel
+instabilities driven by ion temperature anisotropy, defined as
+$\alpha=(T_\perp/T_\parallel)-1$ where $T_\perp$ and $T_\parallel$ are ion
+temperatures perpendicular and parallel to the wave vector, are derived in the
+small $\alpha$-limit. It is shown that the ratio of the saturated magnetic
+energy to the initial ion energy scales as the fourth power of the electron to
+ion mass ratio, $m/M$, for an initially unmagnetized plasma with $\alpha\leq
+M/m$. Particle-in-cell simulations confirm the mass scaling and also show that
+the electron energy gain is of the same order of magnitude as the magnetic
+field energy. This implies that the Weibel instabilities cannot provide a
+faster-than-Coulomb collisionless mechanism to equilibrate ion-electron plasmas
+with ions initially much hotter than electrons, a key component in
+low-luminosity astrophysical accretion flows. The results here also show that
+the large $\alpha$-limit formulae used in the study of magnetic field
+generation in collisionless shocks are only valid if $\alpha\geq M/m$.",0608041v2
+2012-11-02,Giant saturation magnetization effect in epitaxial Fe16N2 thin films grown on MgO (001) substrate,"Whether {\alpha}double prime-Fe16N2 possesses a giant saturation
+magnetization (Ms) has been a daunting problem among magnetic researchers for
+almost 40 years, mainly due to the unshakable faith of famous Slater-Pauling
+(SP) curve and poor consistency on evaluating its Ms. Here we demonstrate that,
+using epitaxy and mis-fit strain imposed by an underlying substrate, the
+in-plane lattice constant of Fe16N2 thin films can be fine tuned to create
+favorable conditions for exceptionally large saturation magnetization. Combined
+study using polarized neutron reflectometry and X-ray diffraction shows that
+with increasing strain at the interface the Ms of these film can be changed
+over a broad range, from ~2.1T (non-high Ms) up to ~3.1T (high Ms). We suggest
+that the equilibrium in-plane lattice constant of Fe16N2 sits in the vicinity
+of the spin crossover point, in which a transition between low spin to high
+spin configuration of Fe sites can be realized with sensitive adjustment of
+crystal structure.",1211.0555v1
+2014-12-11,High-field magnetic resonance of spinons and magnons in a triangular lattice S=1/2 antiferromagnet Cs2CuCl4,"The electron spin resonance doublet indicating the width of the two spinon
+continuum in a spin-1/2 triangular-lattice Heisenberg antiferromagnet Cs2CuCl4
+was studied in high magnetic field. The doublet was found to collapse in a
+magnetic field of a half of the saturation field. The collapse of the doublet
+occurs via vanishing of the high frequency component in a qualitative agreement
+with the theoretical prediction for the S=1/2 chain. The field of the collapse
+is, however, much lower than expected for the S=1/2 chain. This is proposed to
+be due to the destruction of frustration of interchain exchange bonds in a
+magnetic field, which restores the 2D character of this spin system. In the
+saturated phase the mode with the Larmor frequency and a much weaker mode
+downshifted for 119~GHz are observed. The weak mode is of exchange origin, it
+demonstrates a positive frequency shift at heating corresponding to the
+repulsion of magnons in the saturated phase.",1412.3776v1
+2015-08-23,A study of the physical properties of single crystalline Fe5B2P,"Single crystals of Fe5B2P were grown by self-flux growth technique.
+Structural and magnetic properties are studied. The Curie temperature of Fe5B2P
+is determined to be 655$pm$2K. The saturation magnetization is determined to be
+1.72 MuB/Fe at 2K. The temperature variation of the anisotropy constant K1 is
+determined for the first time, reaching ~0.50 MJ/m3 at 2K, and it is comparable
+to that of hard ferrites. The saturation magnetization is found to be larger
+than the hard ferrites. The first principle calculations of saturation
+magnetization and anisotropy constant are found to be consistent with the
+experimental results.",1508.05629v1
+2016-05-27,A comparison between grid and particle methods on the small-scale dynamo in magnetised supersonic turbulence,"We perform a comparison between the smoothed particle magnetohydrodynamics
+(SPMHD) code, Phantom, and the Eulerian grid-based code, Flash, on the
+small-scale turbulent dynamo in driven, Mach 10 turbulence. We show, for the
+first time, that the exponential growth and saturation of an initially weak
+magnetic field via the small-scale dynamo can be successfully reproduced with
+SPMHD. The two codes agree on the behaviour of the magnetic energy spectra, the
+saturation level of magnetic energy, and the distribution of magnetic field
+strengths during the growth and saturation phases. The main difference is that
+the dynamo growth rate, and its dependence on resolution, differs between the
+codes, caused by differences in the numerical dissipation and shock capturing
+schemes leading to differences in the effective Prandtl number in Phantom and
+Flash.",1605.08662v1
+2017-10-02,Magnetic phase transitions and unusual antiferromagnetic states in the Hubbard model,"Ground state magnetic phase diagrams of the square and simple cubic lattices
+are investigated for the narrow band Hubbard model within the slave-boson
+approach by Kotliar and Ruckenstein. The transitions between saturated
+(half-metallic) and non-saturated ferromagnetic phases as well as similar
+transition in antiferromagnetic (AFM) state are considered in the
+three-dimensional case. Two types of saturated antiferromagnetic state with
+different concentration dependences of sublattice magnetization are found in
+the two-dimensional case in the vicinity of half-filling: the state with a gap
+between AFM subbands and AFM state with large electron mass. The latter state
+is hidden by the phase separation in the finite-U case.",1710.00712v1
+2018-05-18,Magnetic Field Saturation of the Ion Weibel Instability in Interpenetrating Relativistic Plasmas,"The time evolution and saturation of the Weibel instability at the ion
+Alfv\'en current are presented by ab initio particle-in-cell simulations. We
+found that the ion Weibel current in 3D could evolve into the Alfv\'en current
+where the magnetic field energy is sustained at 1.5\% of the initial beam
+kinetic energy. The current filaments are no longer isolated at saturation, but
+rather connected to each other to form a network structure. Electrons are
+continuously heated during the coalescence of the filaments, which is crucial
+for obtaining sustained magnetic fields with much stronger levels than with 2D
+simulations. The results highlight again the importance of the Weibel
+instability in generating magnetic fields in laboratory, astrophysical, and
+cosmological situations.",1805.07188v1
+2019-02-21,Understanding quality control of hard metals in industry -- A quantum mechanics approach,"For many decades, the magnetic saturation of, e.g. hard metals (HM) such as
+WC-Co-based cemented carbides, has been used as process and quality control in
+industry to ensure consistency of product properties. In an urge of replacing
+cobalt as a binder phase, a demand on understanding the magnetic response as a
+function of composition on the atomic scale is growing. In this paper, a
+theoretical description of the measured weight specific magnetic saturation of
+hard metals as a function of the tungsten weight fraction present in the cobalt
+binder phase, based on first-principle calculations, has been established for
+standard WC-Co. The predicted magnetic saturation agrees well with the
+experimental one. Furthermore, it is proposed that the theoretical description
+can be extended to alternative and more complex binder phases which allows to
+transfer the production control to those hard metals.",1902.08193v1
+2020-11-23,Asymmetric spin wave dispersion due to a saturation magnetization gradient,"We demonstrate using micromagnetic simulations and a theoretical model that a
+gradient in the saturation magnetization ($M_s$) of a perpendicularly
+magnetized ferromagnetic film induces a non-reciprocal spin wave propagation
+and, consequently an asymmetric dispersion relation. The $M_s$ gradient adds a
+linear potential to the spin wave equation of motion consistent with the
+presence of a force. We consider a transformation from an inertial reference
+frame in which the $M_s$ is constant to an accelerated reference frame where
+the resulting inertial force corresponds to the force from the $M_s$ gradient.
+As in the Doppler effect, the frequency shift leads to an asymmetric dispersion
+relation. Additionally, we show that under certain circumstances,
+unidirectional propagation of spin waves can be achieved which is essential for
+the design of magnonic circuits. Our results become more relevant in light of
+recent experimental works in which a suitable thermal landscape is used to
+dynamically modulate the saturation magnetization.",2011.11148v2
+2023-11-25,Imaging a Semi-Analytical Jet model Generated by 3D GRMHD Simulation,"Employing 3D GRMHD simulation, we study the images of a geometrically thin
+jet, whose emissions concentrate on its surface, for accretion system
+surrounding a central spinning BH. By introducing a strong magnetic field, we
+observe three phases of BH accretion evolution: (a) initially, both the
+accretion rate and the magnetic flux on the horizon gradually increase; (b) at
+an intermediate stage, the magnetic flux approximately reaches saturation, and
+a jet forms via the Blandford-Znajek (BZ) mechanism; (c) ultimately, the entire
+system achieves a dynamic equilibrium, and a magnetically arrested disk (MAD)
+forms. We carefully study the jet images during the saturation and MAD regimes
+at various frequencies and from different observational angles. We reveal the
+presence of U-shaped brighter lines near the jet surface boundaries, which can
+be attributed to the photons whose trajectories skim over the jet surface. The
+existence of these brighter lines is a unique feature of a geometrically thin
+jet. Moreover, we notice that the jet images are relatively insensitive to the
+observed frequencies of interest. Additionally, we observe that the
+time-averaged images for the highly oscillating MAD regime show only slight
+differences from those of the saturation regime.",2311.14954v1
+2009-02-05,The Saturation Limit of the Magnetorotational Instability,"Simulations of the magnetorotational instability (MRI) in a homogeneous
+shearing box have shown that the asymptotic strength of the magnetic field
+declines steeply with increasing resolution. Here I model the MRI driven dynamo
+as a large scale dynamo driven by the vertical magnetic helicity flux. This
+growth is balanced by large scale mixing driven by a secondary instability. The
+saturated magnetic energy density depends almost linearly on the vertical
+height of the typical eddies. The MRI can drive eddies with arbitrarily large
+vertical wavenumber, so the eddy thickness is either set by diffusive effects,
+by the magnetic tension of a large scale vertical field component, or by
+magnetic buoyancy effects. In homogeneous, zero magnetic flux, simulations only
+the first effect applies and the saturated limit of the dynamo is determined by
+explicit or numerical diffusion. The exact result depends on the numerical
+details, but is consistent with previous work, including the claim that the
+saturated field energy scales as the gas pressure to the one quarter power
+(which we interpret as an artifact of numerical dissipation). The magnetic
+energy density in a homogeneous shearing box will tend to zero as the
+resolution of the simulation increases, but this has no consequences for the
+dynamo or for angular momentum transport in real accretion disks. The claim
+that the saturated state depends on the magnetic Prandtl number may also be an
+artifact of simulations in which microphysical transport coefficients set the
+MRI eddy thickness. Finally, the efficiency of the MRI dynamo is a function of
+the ratio of the Alfv\'en velocity to the product of the pressure scale height
+and the local shear. As this approaches unity from below the dynamo reaches
+maximum efficiency.",0902.0942v1
+2010-03-04,Small-scale dynamo action during the formation of the first stars and galaxies. I. The ideal MHD limit,"We explore the amplification of magnetic seed fields during the formation of
+the first stars and galaxies. During gravitational collapse, turbulence is
+created from accretion shocks, which may act to amplify weak magnetic fields in
+the protostellar cloud. Numerical simulations showed that such turbulence is
+sub-sonic in the first star-forming minihalos, and highly supersonic in the
+first galaxies with virial temperatures larger than 10^4 K. We investigate the
+magnetic field amplification during the collapse both for Kolmogorov and
+Burgers-type turbulence with a semi-analytic model that incorporates the
+effects of gravitational compression and small-scale dynamo amplification. We
+find that the magnetic field may be substantially amplified before the
+formation of a disk. On scales of 1/10 of the Jeans length, saturation occurs
+after ~10^8 yr. Although the saturation behaviour of the small-scale dynamo is
+still somewhat uncertain, we expect a saturation field strength of the order
+~10^{-7} n^{0.5} G in the first star-forming halos, with n the number density
+in cgs units. In the first galaxies with higher turbulent velocities, the
+magnetic field strength may be increased by an order of magnitude, and
+saturation may occur after 10^6 to 10^7 yr. In the Kolmogorov case, the
+magnetic field strength on the integral scale (i.e. the scale with most
+magnetic power) is higher due to the characteristic power-law indices, but the
+difference is less than a factor of 2 in the saturated phase. Our results thus
+indicate that the precise scaling of the turbulent velocity with length scale
+is of minor importance. They further imply that magnetic fields will be
+significantly enhanced before the formation of a protostellar disk, where they
+may change the fragmentation properties of the gas and the accretion rate.",1003.1135v2
+2013-05-29,Multiferroicity with coexisting isotropic and anisotropic spins in Ca$_{3}$Co$_{2-x}$Mn$_{x}$O$_{6}$,"We study magnetic and multiferroic behavior in Ca$_3$Co$_{2-x}$Mn$_{x}$O$_6$
+($x \sim$0.97) by high-field measurements of magnetization ($M$),
+magnetostriction ($L$($H$)/$L$), electric polarization ($P$), and
+magnetocaloric effect. This study also gives insight into the zero and low
+magnetic field magnetic structure and magnetoelectric coupling mechanisms. We
+measured $M$ and $\Delta$$L$/$L$ up to pulsed magnetic fields of 92 T, and
+determined the saturation moment and field. On the controversial topic of the
+spin states of Co$^{2+}$ and Mn$^{4+}$ ions, we find evidence for $S$ = 3/2
+spins for both ions with no magnetic field-induced spin-state crossovers. Our
+data also indicate that Mn$^{4+}$ spins are quasi-isotropic and develop
+components in the $ab$-plane in applied magnetic fields of 10 T. These spins
+cant until saturation at 85 T whereas the Ising Co$^{2+}$ spins saturate by 25
+T. Furthermore, our results imply that mechanism for suppression of electric
+polarization with magnetic fields near 10 T is flopping of the Mn$^{4+}$ spins
+into the $ab$-plane, indicating that appropriate models must include the
+coexistence of Ising and quasi-isotropic spins.",1305.6892v3
+2017-08-05,Modification of the Magnetic Properties of Co2Y Hexaferrites by Divalent and Trivalent Metal Substitutions,"The present study is concerned with the fabrication and characterization of
+Me2Y substituted hexaferrites, Ba2Me2Fe12-xTxO22 (Me = Co2+, Mg2+, and Cr2+,
+and T = Fe3+, and Ga3+). The samples were prepared by the conventional ball
+milling technique and sintering at 1200{\deg} C. The effect of the choices of
+Me and T ions on the structural and magnetic properties of the hexaferrites
+were investigated. XRD patterns, magnetic parameters, and M\""ossbauer spectra
+of the Co2Y were consistent with a single phase Y-type hexaferrite. However,
+the CoCr-Y sample was found to be dominated by the Y-type hexaferrite, and
+M-type and BaCrO4 minority phases were observed in the XRD pattern of the
+sample. The small increase in saturation magnetization from about 34 emu/g up
+to 37.5 emu/g was therefore attributed to the development of the M-type phase.
+On the other hand, XRD pattern of the Cr2Y sample indicated the dominance of
+the M-type phase in this sample. The high coercivity (1445 Oe) of this sample
+is evidence of the transformation of the material from a typically soft
+magnetic material (Y-type) to a hard magnet (M-type). The Ga-substitution for
+Fe in Co2Y did not affect the saturation magnetization significantly, but the
+coercivity was reduced. However, the sample Ba2CoMgFe11GaO22 exhibited a
+significant reduction of the saturation magnetization down to a value 26.6
+emu/g, which could be due to the attenuation of the super-exchange interactions
+induced by the Mg2+ substitution.",1708.01768v1
+2018-05-15,Non-linear Galactic Dynamos and the Magnetic Rädler Effect,"We show that the magnetic analogue of the R\""{a}dler effect of mean-field
+dynamo theory leads to a non-linear backreaction that quenches a large-scale
+galactic dynamo, and can result in saturation of the large-scale magnetic field
+at near-equipartition with turbulent kinetic energy density. In a rotating
+fluid containing small-scale magnetic fluctuations, anisotropic terms in the
+mean electromotive force are induced via the Coriolis effect and these terms
+lead to a reduction of the growth rate in a predominantly $\alpha\Omega$-type
+galactic dynamo (Chamandy & Singh 2017). By including the generation of
+small-scale magnetic fluctuations by turbulent tangling of the large-scale
+magnetic field, one obtains a negative feedback effect that quenches the dynamo
+and leads to the saturation of the large-scale field. This saturation mechanism
+is found to be competitive with the dynamical $\alpha$-quenching mechanism for
+realistic galactic parameter values. Furthermore, in the context of the
+dynamical $\alpha$-quenching model, a separate non-linear term is obtained
+which has the same form as the helicity flux term of Vishniac & Cho (2001), but
+which depends on the strength of small-scale magnetic fluctuations. We briefly
+discuss the observational implications of the magnetic R\""{a}dler effect for
+galaxies.",1805.05548v2
+2009-08-13,Angular Momentum Transport in Protoplanetary and Black-Hole Accretion Disks: The Role of Parasitic Modes in the Saturation of MHD Turbulence,"The magnetorotational instability (MRI) is considered a key process for
+driving efficient angular momentum transport in astrophysical disks.
+Understanding its non-linear saturation constitutes a fundamental problem in
+modern accretion disk theory. The large dynamical range in physical conditions
+in accretion disks makes it challenging to address this problem only with
+numerical simulations. We analyze the concept that (secondary) parasitic
+instabilities are responsible for the saturation of the MRI. Our approach
+enables us to explore dissipative regimes that are relevant to astrophysical
+and laboratory conditions that lie beyond the regime accessible to current
+numerical simulations. We calculate the spectrum and physical structure of
+parasitic modes that feed off the fastest, exact (primary) MRI mode when its
+amplitude is such that the fastest parasitic mode grows as fast as the MRI. We
+argue that this ""saturation"" amplitude provides an estimate of the magnetic
+field that can be generated by the MRI before the secondary instabilities
+suppress its growth significantly. Recent works suggest that the saturation
+amplitude of the MRI depends mainly on the magnetic Prandtl number. Our results
+suggest that, as long as viscous effects do not dominate the fluid dynamics,
+the saturation level of the MRI depends only on the Elsasser number
+$\Lambda_\eta$. We calculate the ratio between the stress and the magnetic
+energy density, $\alpha_{\rm sat}\beta_{\rm sat}$, associated with the primary
+MRI mode. We find that for $\Lambda_\eta >1$ Kelvin-Helmholtz modes are
+responsible for saturation and $\alpha_{\rm sat}\beta_{\rm sat} = 0.4$, while
+for $\Lambda_\eta < 1$ tearing modes prevail and $\alpha_{\rm sat}\beta_{\rm
+sat} \simeq 0.5 \, \Lambda_\eta$. Several features of MRI simulations in
+accretion disks surrounding young stars and compact objects can be interpreted
+in terms of our findings.",0908.1791v2
+2021-02-24,Phases saturation control on mixing driven reactions in 3D porous media,"Transported chemical reactions in unsaturated porous media are relevant
+across a range of environmental and industrial applications. Continuum scale
+dispersive models are often based on equivalent parameters derived from analogy
+with saturated conditions, and cannot appropriately account for processes such
+as incomplete mixing. It is also unclear how the third dimension controls
+mixing and reactions in unsaturated conditions. We obtain 3$D$ experimental
+images of the phases distribution and of transported chemical reaction by
+Magnetic Resonance Imaging (MRI) using an immiscible non-wetting liquid as a
+second phase and a fast irreversible bimolecular reaction. Keeping the P\'eclet
+number (Pe) constant, we study the impact of phases saturation on the dynamics
+of mixing and the reaction front. By measuring the local concentration of the
+reaction product, we quantify temporally resolved effective reaction rate
+($R$). We describe the temporal evolution of $R$ using the lamellar theory of
+mixing, which explains faster than Fickian ($t^{0.5}$) rate of product
+formation by accounting for the deformation of mixing interface between the two
+reacting fluids. For a given Pe, although stretching and folding of the
+reactive front are enhanced as saturation decreases, enhancing the product
+formation, this is larger as saturation increases, i.e., volume controlled.
+After breakthrough, the extinction of the reaction takes longer as saturation
+decreases because of the larger non-mixed volume behind the front. These
+results are the basis for a general model to better predict reactive transport
+in unsaturated porous media not achievable by the current continuum paradigm.",2102.12113v1
+2004-05-04,Oscillations of the Electric-Dipole Echo in Glasses in a Magnetic Field,"Using a simple diagram technique we derive the electric-dipole echo amplitude
+from two-level systems with a quadrupole nuclear moment in glasses in an
+external magnetic field. We show, that due to the quadrupole moment interaction
+of a tunneling particle with a gradient of an internal electric field, the echo
+amplitude experiences oscillations in rather weak magnetic fields. With an
+increase of the magnetic field, when the Zeeman energy becomes larger than the
+quadrupole energy splitting, the average echo amplitude increases and saturates
+(for high magnetic fields) at some level which is above the average level of
+echo oscillations for small magnetic fields.",0405058v1
+1994-07-22,Thermal Versus Vacuum Magnetization in QED,"The magnetized relativistic Fermi and Bose gases are studied at finite
+temperature and density.In the case of the Fermi gas, the contribution to the
+magnetization from the vacuum becomes dominant for high magnetic fields, when
+the thermal contribution saturates.
+  In the case of the charged Bose gas, the (paramagnetic) vacuum--magnetization
+becomes dominant when the gas changes from a diamagnetic to a paramagnetic
+behaviour. We furthermore find that the scalar--QED effective coupling constant
+for a weak non--zero external magnetic field is a decreasing function of the
+temperature.",9407356v1
+2010-01-11,Nonlocal effects on magnetism in the diluted magnetic semiconductor Ga_{1-x}Mn_{x}As,"The magnetic properties of the diluted magnetic semiconductor
+Ga_{1-x}Mn_{x}As are studied within the dynamical cluster approximation. We use
+the k-dot-p Hamiltonian to describe the electronic structure of GaAs with
+spin-orbit coupling and strain effects. We show that nonlocal effects are
+essential for explaining the experimentally observed transition temperature and
+saturation magnetization. We also demonstrate that the cluster anisotropy is
+very strong and induces rotational frustration and a cube-edge direction
+magnetic anisotropy at low temperature. With this, we explain the
+temperature-driven spin reorientation in this system.",1001.1716v1
+2011-02-17,Critical magnetization behaviors of the triangular and Kagome lattice quantum antiferromagnets,"We investigate the $S=1/2$ quantum spin antiferromagnets on the triangular
+and Kagome lattices in magnetic field, using the numerical exact
+diagonalization. Particularly we focus on an anomalous magnetization behavior
+of each system at 1/3 of the saturation magnetization. The critical exponent
+analyses suggest that it is a conventional magnetization plateau on the
+triangular lattice, while an unconventional phenomenon, called the
+magnetization ramp, on the Kagome lattice.",1102.3486v1
+2013-12-02,Critical Field of Spin Torque Oscillator with Perpendicularly Magnetized Free Layer,"The oscillation properties of a spin torque oscillator consisting of a
+perpendicularly magnetized free layer and an in-plane magnetized pinned layer
+are studied based on an analysis of the energy balance between spin torque and
+damping. The critical value of an external magnetic field applied normal to the
+film plane is found, below which the controllable range of the oscillation
+frequency by the current is suppressed. The value of the critical field depends
+on the magnetic anisotropy, the saturation magnetization, and the spin torque
+parameter.",1312.0300v1
+2020-10-12,Magnetization steps of $J_{1}$ quintets in the hcp lattice,"The magnetization steps of quintets, consisting of five identical magnetic
+ions coupled by isotropic nearest neighbors antiferromagnetic exchange
+interaction, in the hcp lattice, have been investigated. In that model there
+are 17 types of quintets. The values of the magnetic field of the magnetization
+steps of the quintets have been determined by numerical diagonalization of the
+spin Hamiltonian, which is composed by the isotropic exchange and the Zeeman
+interactions. The quintets are composed of individual spin $S$ = 1/2, 3/2 and
+5/2. The contribution of the quintets for the effective concentration (or
+technical saturation) as a function of the magnetic ions concentration was also
+calculated.",2010.06051v1
+2003-08-28,A Spontaneous Generation of the Magnetic Field and Suppression of the Heat Conduction in Cold Fronts,"We have determined the physical mechanism responsible for the plasma
+instabilities, which was first found by Ramani and Laval (1978), associated
+with anisotropic velocity distributions induced by the temperature gradient in
+which there are growing low frequency transverse magnetic waves, even in the
+absence of background magnetic fields. We have shown that the physical
+mechanism responsible for the growth of one of the modes is identical to the
+Weibel instability. The nonlinear saturation level of the instability is also
+provided by considering the wave-particle interactions. The non-linear
+evolutions of the magnetic fields after the saturation are speculated. The
+results are applied to the cold fronts which is one of the newly discovered
+structures in clusters of galaxies by the Chandra X-ray observatory. We predict
+the existence of the magnetic field of $\sim 10\mu$G tangential to the surface
+over the entire region of the cold front surface and that the heat conduction
+is significantly suppressed by the trapping of the electrons by the generated
+magnetic fields. The instability may provide a new possibility on the origin of
+cosmic magnetic field.",0308503v2
+2006-01-23,Magnetic helicity in primordial and dynamo scenarios of galaxies,"Some common properties of helical magnetic fields in decaying and driven
+turbulence are discussed. These include mainly the inverse cascade that
+produces fields on progressively larger scales. Magnetic helicity also
+restricts the evolution of the large scale field: the field decays less rapidly
+than a non-helical field, but it also saturates more slowly, i.e. on a
+resistive time scale if there are no magnetic helicity fluxes. The former
+effect is utilized in primordial field scenarios, while the latter is important
+for successfully explaining astrophysical dynamos that saturate faster than
+resistively. Dynamo action is argued to be important not only in the galactic
+dynamo, but also in accretion discs in active galactic nuclei and around
+protostars, both of which contribute to producing a strong enough seed magnetic
+field. Although primordial magnetic fields may be too weak to compete with
+these astrophysical mechanisms, such fields could perhaps still be important in
+producing polarization effects in the cosmic background radiation.",0601496v1
+2000-09-01,Lanczos Study of the S=1/2 Frustrated Square-Lattice Antiferromagnet in a Magnetic Field,"We study the zero-temperature phase diagram of the frustrated square-lattice
+S=1/2 antiferromagnet in an external magnetic field numerically with the
+Lanczos algorithm. For strong frustration, we find disordered phases at high
+(and low) magnetic fields. Between these two disordered phases we find a
+plateau in the magnetization curve at half of the saturation magnetization
+which corresponds to a state with up-up-up-down (uuud) spin order. This and
+other considerations [cond-mat/0003343] suggest an unusual ordering scenario:
+There are an ordered phase with a spin gap (the plateau) and disordered
+magnetically gapless phases above and below.
+  The transition to saturation is studied in further detail and problematic
+conclusions in earlier investigations of this region are pointed out.",0009006v1
+2008-02-28,Magnetic studies of multi-walled carbon nanotube mats: Evidence for the paramagnetic Meissner effect,"We report magnetic measurements up to 1200 K on multi-walled carbon nanotube
+mats using Quantum Design vibrating sample magnetometer. Extensive magnetic
+data consistently show two ferrromagnetic-like transitions at about 1000 K and
+1275 K, respectively. The lower transition at about 1000 K is associated with
+an Fe impurity phase and its saturation magnetization is in quantitative
+agreement with the Fe concentration measured by an inductively coupled plasma
+mass spectrometer. On the other hand, the saturation magnetization for the
+higher transition phase ($\geq$1.0 emu/g) is about four orders of magnitude
+larger than that expected from the measured concentration of Co or CoFe, which
+has a high enough Curie temperature to explain this high transition. We show
+that this transition at about 1275 K is not consistent with a magnetic
+proximity effect of Fe-carbon systems and ferromagnetism of any carbon-based
+materials or magnetic impurities but with the paramagnetic Meissner effect due
+to the existence of $\pi$ Josephson junctions in a granular superconductor.",0802.4108v2
+2011-07-27,The effects of plasma beta and anisotropy instabilities on the dynamics of reconnecting magnetic fields in the heliosheath,"The plasma {\beta} (the ratio of the plasma pressure to the magnetic
+pressure) of a system can have a large effect on its dynamics as high {\beta}
+enhances the effects of pressure anisotropies. We investigate the effects of
+{\beta} in a system of stacked current sheets that break up into magnetic
+islands due to magnetic reconnection. We find significant differences between
+{\beta} < 1 and {\beta} > 1. At low {\beta} growing magnetic islands are
+modestly elongated and become round as contraction releases magnetic stress and
+reduces magnetic energy. At high {\beta} the increase of the parallel pressure
+in contracting islands causes saturation of modestly elongated islands as
+island cores approach the marginal firehose condition. Only highly elongated
+islands reach finite size. The kinking associated with the Weibel and firehose
+instabilities prevents full contraction of these islands, leading to a final
+state of highly elongated islands in which further reconnection is suppressed.
+The results are directly relevant to reconnection in the sectored region of the
+heliosheath and possibly to saturation mechanisms of the magnetorotational
+instability in accretion flows.",1107.5558v2
+2012-01-25,Universal Magnetic Properties of sp$^3$-type Defects in Covalently Functionalized Graphene,"Using density-functional calculations, we study the effect of sp$^3$-type
+defects created by different covalent functionalizations on the electronic and
+magnetic properties of graphene. We find that the induced magnetic properties
+are {\it universal}, in the sense that they are largely independent on the
+particular adsorbates considered. When a weakly-polar single covalent bond is
+established with the layer, a local spin-moment of 1.0 $\mu_B$ always appears
+in graphene. This effect is similar to that of H adsorption, which saturates
+one $p_z$ orbital in the carbon layer. The magnetic couplings between the
+adsorbates show a strong dependence on the graphene sublattice of
+chemisorption. Molecules adsorbed at the same sublattice couple
+ferromagnetically, with an exchange interaction that decays very slowly with
+distance, while no magnetism is found for adsorbates at opposite sublattices.
+Similar magnetic properties are obtained if several $p_z$ orbitals are
+saturated simultaneously by the adsorption of a large molecule. These results
+might open new routes to engineer the magnetic properties of graphene
+derivatives by chemical means.",1201.5326v1
+2013-03-04,"Ground-state phase diagram and magnetization process of the exactly solved mixed spin-(1,1/2) Ising diamond chain","The ground state and magnetization process of the mixed spin-(1,1/2) Ising
+diamond chain is exactly solved by employing the generalized
+decoration-iteration mapping transformation and the transfer-matrix method. The
+decoration-iteration transformation is first used in order to establish a
+rigorous mapping equivalence with the corresponding spin-1
+Blume-Emery-Griffiths chain in a non-zero magnetic field, which is subsequently
+exactly treated within the framework of the transfer-matrix technique. It is
+shown that the ground-state phase diagram includes just four different ground
+states and the low-temperature magnetization curve may exhibit an intermediate
+plateau precisely at one half of the saturation magnetization. Our rigorous
+results disprove recent Monte Carlo simulations of Zihua Xin et al. [Z. Xin, S.
+Chen, C. Zhang, J. Magn. Magn. Mater. 324 (2012) 3704], which imply an
+existence of the other magnetization plateaus at 0.283 and 0.426 of the
+saturation magnetization.",1303.0636v1
+2019-07-16,Enhanced Magnetization from Proton Irradiated Bulk van der Waals Magnet CrSiTe3,"Van der Waals (vdWs) crystals have attracted a great deal of scientific
+attention due to their interesting physical properties and widespread practical
+applications. Among all, CrSiTe3 (CST) is a ferromagnetic semiconductor with
+the Curie temperature (TC) of ~32 K. In this letter, we study the magnetic
+properties of bulk CST single-crystal upon proton irradiation with the fluence
+of 1x1018 protons/cm2. Most significantly, we observed an enhancement (23%) in
+the saturation magnetization from 3.9 {\mu}B to 4.8 {\mu}B and is accompanied
+by an increase in the coercive field (465-542 Oe) upon proton irradiation.
+Temperature-dependent X-band electron paramagnetic resonance measurements show
+no additional magnetically active defects/vacancies that are generated upon
+proton irradiation. The findings from X-ray photoelectron spectroscopy and
+Raman measurements lead us to believe that modification in the spin-lattice
+coupling and introduction of disorder could cause enhancement in saturation
+magnetization. This work demonstrates that proton irradiation is a feasible
+method in modifying the magnetic properties of vdWs crystals, which represents
+a significant step forward in designing future spintronic and
+magneto-electronic applications.",1907.07222v2
+2005-02-06,Model for a Macroscopically Disordered Conductor with an Exactly Linear High-Field Magnetoresistance,"We calculate the effective resistivity of a macroscopically disordered two
+dimensional conductor consisting of two components in a perpendicular magnetic
+field. When two components have equal area fractions, we use a duality theorem
+to show that the magnetoresistance is non-saturating and at high fields varies
+exactly linearly with magnetic field. At other compositions, an effective
+medium calculation leads to a saturating magnetoresistance. We briefly discuss
+possible connections between these results and magnetoresistance measurements
+on heavily disordered chalconide semiconductors.",0502162v2
+2006-03-20,Influence of lattice distortions in classical spin systems,"We investigate a simple model of a frustrated classical spin chain coupled to
+adiabatic phonons under an external magnetic field. A thorough study of the
+magnetization properties is carried out both numerically and analytically. We
+show that already a moderate coupling with the lattice can stabilize a plateau
+at 1/3 of the saturation and discuss the deformation of the underlying lattice
+in this phase. We also study the transition to saturation where either a first
+or second order transition can occur, depending on the couplings strength.",0603514v2
+2006-01-26,Further Results on Active Magnetic Bearing Control with Input Saturation,"We study the low-bias stabilization of active magnetic bearings (AMBs)
+subject to voltage saturation based on a recently proposed model for the AMB
+switching mode of operation. Using a forwarding-like approach, we construct a
+stabilizing controller of arbitrarily small amplitude and a control-Lyapunov
+function for the AMB dynamics. We illustrate our construction using a numerical
+example.",0601650v1
+1996-12-31,Resonance Broadening Induced Nonlinear Saturation of Kinetic Alfven Turbulence in the Interplanetary Plasma,"The saturation of ion cyclotron Alfven turbulence excited by beam particles
+is investigated using resonance broadening theory. The stochastic scattering
+which decorrelates particles, includes both random acceleration by electric
+fields and a turbulent magnetic mirroring effect. Turbulent mirroring is shown
+to yield non-Gaussian corrections to the orbits even if the random electric and
+magnetic fields are Gaussian. The predicted steady-state turbulence level
+exhibits a peaked anglular distribution, with a maximum near Theta ~ 60
+degrees.",9612019v1
+2008-01-10,The magneto-rotational instability near threshold: spatio-temporal amplitude equation and saturation,"We show, by means of a perturbative weakly nonlinear analysis, that the
+axisymmetric magneto-rotational instability (MRI) in a magnetic Taylor-Couette
+(mTC) flow in a thin-gap gives rise, for very small magnetic Prandtl numbers
+(P_m), to a real Ginzburg-Landau equation for the disturbance amplitude. The
+saturation amplitude A_s is found to scale in this regime as P^\delta, with
+1/2<\delta<2/3 (depending on the boundary conditions adopted). The asymptotic
+results are shown to comply with numerical calculations performed by using a
+spectral code. They suggest that the transport due to the nonlinearly developed
+MRI may be vanishingly small for P_m << 1.",0801.1637v1
+2010-05-26,Ferromagnetism in the Highly-Correlated Hubbard Model,"The Hubbard model with strong correlations is treated in the many-electron
+representation of Hubbard's operators. The regions of stability of saturated
+and non-saturated ferromagnetism in the n-U plane for the square and simple
+cubic lattices are calculated. The role of the bare density of states
+singularities for the magnetic phase diagram is discussed. A comparison with
+the results of previous works is performed.",1005.4795v1
+2011-03-08,Saturation of a spin 1/2 particle by generalized Local control,"We show how to apply a generalization of Local control design to the problem
+of saturation of a spin 1/2 particle by magnetic fields in Nuclear Magnetic
+Resonance. The generalization of local or Lyapunov control arises from the fact
+that the derivative of the Lyapunov function does not depend explicitly on the
+control field. The second derivative is used to determine the local control
+field. We compare the efficiency of this approach with respect to the
+time-optimal solution which has been recently derived using geometric methods.",1103.1570v1
+2013-12-16,Physical properties of CeGe2-x (x = 0.24) single crystals,"We present data on the anisotropic magnetic properties, heat capacity and
+transport properties of CeGe2-x (x = 0.24) single crystals. The electronic
+coefficient of the heat capacity, gamma ~ 110 mJ/mol K^2, is enhanced; three
+magnetic transitions, with critical temperatures of ~ 7 K, ~ 5 K, and ~ 4 K are
+observed in thermodynamic and transport measurements. The ground state has a
+small ferromagnetic component along the c - axis. Small applied field, below 10
+kOe, is enough to bring the material to an apparent saturated paramagnetic
+state (with no further metamagnetic transitions up to 55 kOe) with a reduced,
+below 1 mu_B, saturated moment.",1312.4580v1
+2014-05-02,Dynamic nuclear polarization from current-induced electron spin polarization,"Current-induced electron spin polarization is shown to produce nuclear
+hyperpolarization through dynamic nuclear polarization. Saturated fields of
+several millitesla are generated upon the application of electric field over a
+timescale of a hundred seconds in InGaAs epilayers and measured using optical
+Larmor magnetometry. The dependence on temperature, external magnetic field,
+and applied voltage is investigated. We find an asymmetry in which the
+saturation nuclear field depends on the relative alignment of the electrically
+generated spin polarization and the external magnetic field, which we attribute
+to an interplay between various electron spin dynamical processes.",1405.0342v1
+2017-03-09,Distinct turbulence saturation regimes in stellarators,"In the complex 3D magnetic fields of stellarators, ion-temperature-gradient
+turbulence is shown to have two distinct saturation regimes, as revealed by
+petascale numerical simulations, and explained by a simple turbulence theory.
+The first regime is marked by strong zonal flows, and matches previous
+observations in tokamaks. The newly observed second regime, in contrast,
+exhibits small- scale quasi-two-dimensional turbulence, negligible zonal flows,
+and, surprisingly, a weaker heat flux scaling. Our findings suggest that key
+details of the magnetic geometry control turbulence in stellarators.",1703.03257v2
+2019-09-16,Experimental Confirmation of Quantum Hall Ferromagnetic State in an Organic Dirac Fermion System,"We have experimentally confirmed the quantum Hall ferromagnetic state with
+Chern number \nu=0, characterized by the helical edge state, in a layered
+organic Dirac fermion system \alpha-(BEDT-TTF)_2I_3. The interlayer resistance
+saturates at low temperatures and high magnetic fields. It does not scale with
+the sample cross-sectional area in the saturating region, and resonantly
+depends on the magnetic field direction. These results strongly suggest that
+the helical edge state dominates transport. This is the first observation of
+the topological phase in organic molecular crystals.",1909.07006v1
+2008-08-07,Large-scale dynamos at low magnetic Prandtl numbers,"Using direct simulations of hydromagnetic turbulence driven by random
+polarized waves it is shown that dynamo action is possible over a wide range of
+magnetic Prandtl numbers from 10^-3 to 1. Triply periodic boundary conditions
+are being used. In the final saturated state the resulting magnetic field has a
+large-scale component of Beltrami type. For the kinematic phase, growth rates
+have been determined for magnetic Prandtl numbers between 0.01 and 1, but only
+the case with the smallest magnetic Prandtl number shows large-scale magnetic
+fields. It is less organized than in the nonlinear stage. For small magnetic
+Prandtl numbers the growth rates are comparable to those calculated from an
+alpha squared mean-field dynamo. In the linear regime the magnetic helicity
+spectrum has a short inertial range compatible with a -5/3 power law, while in
+the nonlinear regime it is the current helicity whose spectrum may be
+compatible with such a law. In the saturated case, the spectral magnetic energy
+in the inertial range is in slight excess over the spectral kinetic energy,
+although for small magnetic Prandtl numbers the magnetic energy spectrum
+reaches its resistive cut off wavenumber more quickly. The viscous energy
+dissipation declines with the square root of the magnetic Prandtl number, which
+implies that most of the energy is dissipated via Joule heat.",0808.0961v2
+2014-11-03,"Anisotropic putative ""up-up-down"" magnetic structure in EuTAl$_4$Si$_2$ (T = Rh and Ir)","We present detailed investigations in single crystals of two recently
+reported quaternary intermetallic compounds EuRhAl$_4$Si$_2$ and
+EuIrAl$_4$Si$_2$ employing magnetization, electrical resistivity in zero and
+applied fields, heat capacity and $^{151}$Eu M\""{o}ssbauer spectroscopy
+measurements. The two compounds order antiferromagnetically at $T_{\rm N1}$ =
+11.7 and 14.7\,K, respectively, each undergoing two magnetic transitions: the
+first from paramagnetic to incommensurate modulated antiferromagnetic, the
+second at lower temperature to a commensurate antiferromagnetic phase as
+confirmed by heat capacity and M\""{o}ssbauer spectra. The magnetic properties
+in the ordered state present a large anisotropy despite Eu$^{2+}$ being an
+$S$-state ion for which the single-ion anisotropy is expected to be weak. Two
+features in the magnetization measured along the $c$-axis are prominent. At
+1.8\,K, a ferromagnetic-like jump occurs at very low field to a value one third
+of the saturation magnetization (1/3 M$_0$) followed by a wide plateau up to
+2\,T for T = Rh and 4\,T for T = Ir. At this field value, a sharp hysteretic
+spin-flop transition occurs to a fully saturated state (M$_0$). Surprisingly,
+the magnetization does not return to origin when the field is reduced to zero
+in the return cycle, as expected in an antiferromagnet. Instead, a remnant
+magnetization 1/3 M$_0$ is observed and the magnetic loop around the origin
+shows hysteresis. This suggests that the zero field magnetic structure has a
+ferromagnetic component, and we present a model with up to third neighbor
+exchange and dipolar interaction which reproduces the magnetization curves and
+hints to an ""up-up-down"" magnetic structure in zero field.",1411.0379v1
+2015-06-09,On the absence of actual plateaus in zero-temperature magnetization curves of quantum spin clusters and chains,"We examine the general features of the non-commutativity of the magnetization
+operator and Hamiltonian for the small quantum spin clusters. The source of
+this non-commutativity can be a difference in the Land\'{e} g-factors for
+different spins in the cluster, XY-anisotropy in the exchange interaction and
+the presence of the Dzyaloshinskii-Moriya term in the direction different for
+the direction of the magnetic field. As a result, a zero-temperature
+magnetization curve for the small spin clusters mimics that for the macroscopic
+systems with the band(s) of magnetic excitations, i.e. for the given eigenstate
+of the spin cluster the corresponding magnetic moment can be an explicit
+function of the external magnetic field yielding the non-constant (non-plateau)
+form of the magnetization curve within the given eigenstate. Also, the
+XY-anisotropy makes the saturated magnetization (the eigenstate when all spins
+in cluster are aligned along the magnetic field) inaccessible for finite
+magnetic field magnitude (asymptotical saturation). We demonstrate all these
+features on three examples: spin-1/2 dimer, mixed spin-(1/2,1) dimer, spin-1/2
+ring trimer. We consider the simplest Ising-Heisenberg chain, the XYZ-Ising
+diamond chain with four different g-factors as well. In the chain model the
+magnetization curve has more complicated and non trivial structure with than
+that for clusters.",1506.02933v2
+2016-01-19,Collective magnetic response of CeO2 nanoparticles,"The magnetism of nanoparticles and thin films of wide-bandgap oxides that
+include no magnetic cations is an unsolved puzzle. Progress has been hampered
+both by the irreproducibility of much of the experimental data, and the lack of
+any generally-accepted theoretical explanation. The characteristic signature is
+a virtually anhysteretic, temperature-independent magnetization curve which
+saturates in an applied field that is several orders of magnitude greater than
+the magnetization. It appears as if a tiny volume fraction, < 0.1%, of the
+samples is magnetic and that the energy scale of the problem is unusually high
+for spin magnetism. Here we investigate the effect of dispersing 4 nm CeO2
+nanoparticles with powders of gamma-Al2O3, sugar or latex microspheres. The
+saturation magnetization, Ms ~ 60 A/m for compact samples, is maximized by 1
+wt% lanthanum doping. Dispersing the CeO2 nanopowder reduces its magnetic
+moment by up to an order of magnitude. There is a characteristic length scale
+of order 100 nm for the magnetism to appear in CeO2 nanoparticle clusters. The
+phenomenon is explained in terms of a giant orbital paramagnetism that appears
+in coherent mesoscopic domains due to resonant interaction with zero-point
+fluctuations of the vacuum electromagnetic field. The theory explains the
+observed temperature-independent magnetization curve and its doping and
+dispersion dependence, based on a length scale of 300 nm that corresponds to
+the wavelength of a maximum in the UV absorption spectrum of the magnetic CeO2
+nanoparticles. The coherent domains occupy roughly ten percent of the sample
+volume.",1601.04933v1
+1999-01-13,Growth and saturation of the Kelvin-Helmholtz instability with parallel and anti-parallel magnetic fields,"We investigate the Kelvin-Helmholtz instability occuring at the interface of
+a shear flow configuration in 2D compressible magnetohydrodynamics (MHD). The
+linear growth and the subsequent non-linear saturation of the instability are
+studied numerically. We consider an initial magnetic field aligned with the
+shear flow, and analyze the differences between cases where the initial field
+is unidirectional everywhere (uniform case), and where the field changes sign
+at the interface (reversed case). We recover and extend known results for pure
+hydrodynamic and MHD cases with a discussion of the dependence of the
+non-linear saturation on the wavenumber, the sound Mach number, and the
+Alfvenic Mach number for the MHD case.
+  A reversed field acts to destabilize the linear phase of the Kelvin-Helmholtz
+instability compared to the pure hydrodynamic case, while a uniform field
+suppresses its growth. In resistive MHD, reconnection events almost instantly
+accelerate the buildup of a global plasma circulation. They play an important
+role throughout the further non-linear evolution as well, since the initial
+current sheet gets amplified by the vortex flow and can become unstable to
+tearing instabilities forming magnetic islands. As a result, the saturation
+behaviour and the overall evolution of the density and the magnetic field is
+markedly different for the uniform versus the reversed field case.",9901166v1
+2000-04-05,Ferromagnetism of quark liquid and magnetars,"Spontaneous magnetization of quark liquid is examined on the analogy with
+that in electron gas. It is pointed out that quark liquid has potential to be
+ferromagnetic at rather low densities, around nuclear saturation density. Somme
+comments are given as for implications on magnetars.",0004062v1
+2013-05-29,A Predictive Model of Geosynchronous Magnetopause Crossings,"We have developed a model predicting whether or not the magnetopause crosses
+geosynchronous orbit at given location for given solar wind pressure Psw, Bz
+component of interplanetary magnetic field (IMF) and geomagnetic conditions
+characterized by 1-min SYM-H index. The model is based on more than 300
+geosynchronous magnetopause crossings (GMCs) and about 6000 minutes when
+geosynchronous satellites of GOES and LANL series are located in the
+magnetosheath (so-called MSh intervals) in 1994 to 2001. Minimizing of the Psw
+required for GMCs and MSh intervals at various locations, Bz and SYM-H allows
+describing both an effect of magnetopause dawn-dusk asymmetry and saturation of
+Bz influence for very large southward IMF. The asymmetry is strong for large
+negative Bz and almost disappears when Bz is positive. We found that the larger
+amplitude of negative SYM-H the lower solar wind pressure is required for GMCs.
+We attribute this effect to a depletion of the dayside magnetic field by a
+storm-time intensification of the cross-tail current. It is also found that the
+magnitude of threshold for Bz saturation increases with SYM-H index such that
+for small negative and positive SYM-H the effect of saturation diminishes. This
+supports an idea that enhanced thermal pressure of the magnetospheric plasma
+and ring current particles during magnetic storms results in the saturation of
+magnetic effect of the IMF Bz at the dayside magnetopause. A noticeable
+advantage of the model prediction capabilities in comparison with other
+magnetopause models makes the model useful for space weather predictions.
+Supplement : a program-code of the GMC-model",1305.6707v1
+2023-11-07,Evidence for saturated and disrupted magnetic braking from samples of detached close binaries with M and K dwarfs,"Context. Recent observations of close detached eclipsing M and K dwarf
+binaries have provided substantial support for magnetic saturation when stars
+rotate sufficiently fast, leading to a magnetic braking (MB) torque
+proportional to the spin of the star.
+  Aims. We investigated here how strong MB torques need to be to reproduce the
+observationally-inferred relative numbers of white dwarf plus M dwarf
+post-common-envelope binaries under the assumption of magnetic saturation.
+  Methods. We carried out binary population simulations with the BSE code
+adopting empirically-derived inter-correlated main-sequence binary
+distributions as initial binary populations and compared the simulation
+outcomes with observations.
+  Results. We found that the dearth of extreme mass ratio binaries in the
+inter-correlated initial distributions is key to reproduce the large fraction
+of post-common-envelope binaries hosting low-mass M dwarfs (${\sim0.1-0.2}$
+M$_\odot$). In addition, orbital angular momentum loss rates due to MB should
+be high for M dwarfs with radiative cores and orders of magnitude smaller for
+fully convective stars to explain the observed dramatic change of the fraction
+of short-period binaries at the fully convective boundary.
+  Conclusions. We conclude that saturated but disrupted, that is, dropping
+drastically at the fully convective boundary, MB can explain the observations
+of both close main-sequence binaries containing M and K dwarfs and
+post-common-envelope binaries. Whether a similar prescription can explain the
+spin down rates of single stars and of binaries containing more massive stars
+needs to be tested.",2311.04309v1
+2003-12-18,Angular Momentum Transport by MHD Turbulence in Accretion Disks: Gas Pressure Dependence of the Saturation Level of the Magnetorotational Instability,"The saturation level of the magnetorotational instability (MRI) is
+investigated using three-dimensional MHD simulations. The shearing box
+approximation is adopted and the vertical component of gravity is ignored, so
+that the evolution of the MRI is followed in a small local part of the disk. We
+focus on the dependence of the saturation level of the stress on the gas
+pressure, which is a key assumption in the standard alpha disk model. From our
+numerical experiments it is found that there is a weak power-law relation
+between the saturation level of the Maxwell stress and the gas pressure in the
+nonlinear regime; the higher the gas pressure, the larger the stress. Although
+the power-law index depends slightly on the initial field geometry, the
+relationship between stress and gas pressure is independent of the initial
+field strength, and is unaffected by Ohmic dissipation if the magnetic Reynolds
+number is at least 10. The relationship is the same in adiabatic calculations,
+where pressure increases over time, and nearly-isothermal calculations, where
+pressure varies little with time. Our numerical results are qualitatively
+consistent with an idea that the saturation level of the MRI is determined by a
+balance between the growth of the MRI and the dissipation of the field through
+reconnection. The quantitative interpretation of the pressure-stress relation,
+however, may require advances in the theoretical understanding of non-steady
+magnetic reconnection.",0312480v1
+2004-03-16,Incommensurate state in a quasi-one-dimensional $S=1/2$ bond-alternating antiferromagnet with frustration in magnetic fields,"We investigate the critical properties of the $S=1/2$ bond-alternating spin
+chain with a next-nearest-neighbor interaction in magnetic fields. By the
+numerical calculation and the exact solution based on the effective
+Hamiltonian, we show that there is a parameter region where the longitudinal
+incommensurate spin correlation becomes dominant around the half-magnetization
+of the saturation. Possible interpretations of our results are discussed. We
+next investigate the effects of the interchain interaction ($J^{\prime}$). The
+staggered susceptibility and the uniform magnetization are calculated by
+combining the density-matrix renormalization group method with the interchain
+mean-field theory. For the parameters where the dominant longitudinal
+incommensurate spin correlation appears in the case $J^{\prime}=0$, the
+staggered long-range order does not emerge up to a certain critical value of
+$J^{\prime}$ around the half-magnetization of the saturation. We calculate the
+static structure factor in such a parameter region. The size dependence of the
+static structure factor at $k=2k_{\rm F}$ implies that the system has a
+tendency to form an incommensurate long-range order around the
+half-magnetization of the saturation. We discuss the recent experimental
+results for the NMR relaxation rate in magnetic fields performed for
+pentafluorophenyl nitronyl nitroxide.",0403404v3
+2010-03-31,Local simulations of the magnetized Kelvin-Helmholtz instability in neutron-star mergers,"Context. Global MHD simulations show Kelvin-Helmholtz (KH) instabilities at
+the contact surface of two merging neutron stars. That region has been
+identified as the site of efficient amplification of magnetic fields. However,
+these global simulations, due to numerical limitations, were unable to
+determine the saturation level of the field strength, and thus the possible
+back-reaction of the magnetic field onto the flow. Aims. We investigate the
+amplification of initially weak fields in KH unstable shear flows, and the
+back-reaction of the field onto the flow. Methods. We use a high-resolution
+ideal MHD code to perform 2D and 3D local simulations of shear flows. Results.
+In 2D, the magnetic field is amplified in less than 0.01ms until it reaches
+locally equipartition with the kinetic energy. Subsequently, it saturates due
+to resistive instabilities that disrupt the KH vortex and decelerate the shear
+flow on a secular time scale. We determine scaling laws of the field
+amplification with the initial field strength and the grid resolution. In 3D,
+this hydromagnetic mechanism may be dominated by purely hydrodynamic
+instabilities limiting the amplification. We find maximum magnetic fields of
+10^16 G locally, and r.m.s. maxima within the box of 10^15 G. However, such
+strong fields exist only for a short period. In the saturated state, the
+magnetic field is mainly oriented parallel to the shear flow for strong initial
+fields, while weaker initial fields tend to lead to a more balanced
+distribution of the field energy. In all models the flow shows small-scale
+features. The magnetic field is at most in equipartition with the decaying
+shear flow. (abridged)",1003.6031v1
+2020-12-18,Rare-earth-free ferrimagnetic Mn4N sub-20 nm thin films as high-temperature spintronic material,"Ferrimagnetic alloy thin films that exhibit perpendicular (out-of-plane)
+magnetic anisotropy (PMA) with low saturation magnetization, such as GdCo and
+Mn4N, were predicted to be favorable for hosting small Neel skyrmions for room
+temperature applications. Due to the exponential decay of interfacial
+Dzyaloshinskii-Moriya interaction (DMI) and the limited range of
+spin-orbit-torques, which can be used to drive skyrmion motion, the thickness
+of the ferrimagnetic layer has to be small, preferably under 20 nm. While there
+are examples of sub-20 nm, rare earth-transition metal (RE-TM), ferrimagnetic
+thin films fabricated by sputter deposition, to date rare-earth-free sub-20 nm
+Mn4N films with PMA have only been reported to be achieved by molecular beam
+epitaxy, which is not suitable for massive production. Here we report the
+successful thermal growth of sub-20 nm Mn4N films with PMA at 400-450 {\deg}C
+substrate temperatures on MgO substrates by reactive sputtering. The Mn4N films
+were achieved by reducing the surface roughness of MgO substrate through a
+high-temperature vacuum annealing process. The optimal films showed low
+saturation magnetization (Ms = 43 emu/cc), low magnetic anisotropy energy (0.7
+Merg/cc), and a remanent magnetization to saturation magnetization ratio
+(Mr/Ms) near 1 at room temperature. Preliminary ab-initio density functional
+theory (DFT) calculations have confirmed the ferrimagnetic ground state of Mn4N
+grown on MgO. The magnetic properties, along with the high thermal stability of
+Mn4N thin films in comparison with RE-TM thin films, provide the platform for
+future studies of practical skyrmion-based spintronic materials.",2012.10493v1
+2023-09-27,Magnetic flux plays an important role during a BHXRB outburst in radiative 2T GRMHD simulations,"Black hole (BH) X-ray binaries cycle through different spectral states of
+accretion over the course of months to years. Although fluctuations in the BH
+mass accretion rate are generally recognized as the most important component of
+state transitions, it is becoming increasingly evident that magnetic fields
+play a similarly important role. In this article, we present the first
+radiative two-temperature (2T) general relativistic magnetohydrodynamics
+(GRMHD) simulations in which an accretion disk transitions from a quiescent
+state at an accretion rate of $\dot{M} \sim 10^{-10} \dot{M}_{\rm Edd}$ to a
+hard-intermediate state at an accretion rate of $\dot{M} \sim 10^{-2}
+\dot{M}_{\rm Edd}$. This huge parameter space in mass accretion rate is bridged
+by artificially rescaling the gas density scale of the simulations. We present
+two jetted BH models with varying degrees of magnetic flux saturation. We
+demonstrate that in `Standard and Normal Evolution' models, which are
+unsaturated with magnetic flux, the hot torus collapses into a thin and cold
+accretion disk when $\dot{M} \gtrsim 5\times 10^{-3} \dot{M}_{\rm Edd}$. On the
+other hand, in `Magnetically Arrested Disk' models, which are fully saturated
+with vertical magnetic flux, the plasma remains mostly hot with substructures
+that condense into cold clumps of gas when $\dot{M} \gtrsim 1 \times 10^{-2}
+\dot{M}_{\rm Edd}$. This suggests that the spectral signatures observed during
+state transitions are closely tied to the level of magnetic flux saturation.",2309.15926v2
+2006-06-30,Finite-temperature order-disorder phase transition in a frustrated bilayer quantum Heisenberg antiferromagnet in strong magnetic fields,"We investigate the thermodynamic properties of the frustrated bilayer quantum
+Heisenberg antiferromagnet at low temperatures in the vicinity of the
+saturation magnetic field. The low-energy degrees of freedom of the spin model
+are mapped onto a hard-square gas on a square lattice. We use exact
+diagonalization data for finite spin systems to check the validity of such a
+description. Using a classical Monte Carlo method we give a quantitative
+description of the thermodynamics of the spin model at low temperatures around
+the saturation field. The main peculiarity of the considered two-dimensional
+Heisenberg antiferromagnet is related to a phase transition of the hard-square
+model on the square lattice, which belongs to the two-dimensional Ising model
+universality class. It manifests itself in a logarithmic (low-)temperature
+singularity of the specific heat of the spin system observed for magnetic
+fields just below the saturation field.",0606806v1
+2007-11-02,Dynamical feedback of the curvature drift instability on its saturation process,"We investigate the reconstruction of pulsar magnetospheres close to the light
+cylinder surface to study the curvature drift instability (CDI) responsible for
+the twisting of magnetic field lines in the mentioned zone. The influence of
+plasma dynamics on the saturation process of the CDI is studied. On the basis
+of the Euler, continuity, and induction equations, we derive the increment of
+the CDI and analyze parametrically excited drift modes. The dynamics of the
+reconstruction of the pulsar magnetosphere is studied analytically. We show
+that there is a possibility of a parametrically excited rotational-energy
+pumping-process in the drift modes. It is indicated by the generation of a
+toroidal component of the magnetic field that transforms the field lines into
+such a configuration, in which plasma particles do not experience any forces.
+At this stage, the instability process saturates and the further amplification
+of the toroidal component to the magnetic field lines is suspended.",0711.0295v8
+2009-10-01,The filamentation instability driven by warm electron beams: Statistics and electric field generation,"The filamentation instability of counterpropagating symmetric beams of
+electrons is examined with 1D and 2D particle-in-cell (PIC) simulations, which
+are oriented orthogonally to the beam velocity vector. The beams are uniform,
+warm and their relative speed is mildly relativistic. The dynamics of the
+filaments is examined in 2D and it is confirmed that their characteristic size
+increases linearly in time. Currents orthogonal to the beam velocity vector are
+driven through the magnetic and electric fields in the simulation plane. The
+fields are tied to the filament boundaries and the scale size of the
+flow-aligned and the perpendicular currents are thus equal. It is confirmed
+that the electrostatic and the magnetic forces are equally important, when the
+filamentation instability saturates in 1D. Their balance is apparently the
+saturation mechanism of the filamentation instability for our initial
+conditions. The electric force is relatively weaker but not negligible in the
+2D simulation, where the electron temperature is set higher to reduce the
+computational cost. The magnetic pressure gradient is the principal source of
+the electrostatic field, when and after the instability saturates in the 1D
+simulation and in the 2D simulation.",0910.0228v1
+2010-02-02,Low magnetic-Prandtl number flow configurations for cold astrophysical disk models: speculation and analysis,"Simulations of astrophysical disks in the shearing box that are subject to
+the magnetorotational instability (MRI) show that activity appears to be
+reduced as the magnetic Prandtl number (Pm) is lowered. On the other hand,
+calculations for laboratory experiments show that saturation is achieved
+through modification of the background shear for Pm << 1. Guided by the results
+of calculations appropriate for laboratory experiments when Pm is very low, the
+axisymmetric stability of inviscid disturbances in a shearing box model
+immersed in a constant vertical background magnetic field is considered under a
+variety of shear profiles and boundary conditions in order to evaluate the
+hypothesis that modifications of the shear bring about saturation of the
+instability. It is found that the emergence and stability of the MRI is
+sensitive to the boundary conditions adopted. Channel modes do not appear to be
+stabilized through any modification of the background shear whose average
+remains Keplerian. However, systems that have non-penetrative boundaries can
+saturate the MRI through modification of the background shear. Conceptually
+equating the qualitative results from laboratory experiments to the conditions
+in a disk may therefore be misleading.",1002.0506v1
+2011-12-24,Frustrated spin chains in strong magnetic field: dilute two-component Bose gas regime,"We study the ground state of frustrated spin-S chains in a strong magnetic
+field in the immediate vicinity of saturation. In strongly frustrated chains,
+the magnon dispersion has two degenerate minima at inequivalent momenta $\pm
+Q$, and just below the saturation field the system can be effectively
+represented as a dilute one-dimensional lattice gas of two species of bosons
+that correspond to magnons with momenta around $\pm Q$. We present a theory of
+effective interactions in such a dilute magnon gas that allows us to make
+quantitative predictions for arbitrary values of the spin. With the help of
+this method, we are able to establish the magnetic phase diagram of frustrated
+chains close to saturation and study phase transitions between several
+nontrivial states, including a two-component Luttinger liquid, a vector chiral
+phase, and phases with bound magnons. We study those phase transitions
+numerically and find a good agreement with our analytical predictions.",1112.5720v2
+2013-03-26,Double zigzag spin chain in strong magnetic field close to saturation,"We study the ground state phase diagram of a frustrated spin tube in a strong
+external magnetic field. This model can be viewed as two coupled zigzag spin
+chains, or as a two-leg spin ladder with frustrating next-nearest-neighbor
+couplings along the legs, and its study is motivated by the physics of such
+materials as Sulfolane-Cu_{2}Cl_{4} and BiCu_{2}PO_{6}. In magnetic fields
+right below the saturation, the system can be effectively represented as a
+dilute gas of two species of bosonic quasiparticles that correspond to magnons
+with inequivalent incommensurate momenta at two degenerate minima of the magnon
+dispersion. Using the method previously proposed and tested for frustrated spin
+chains, we calculate effective interactions in this two-component Bose gas. On
+this basis, we establish the phase diagram of nearly-saturated frustrated spin
+tube, which is shown to include the two-component Luttinger liquid, two types
+of vector chiral phases, and phases whose physics is determined by the presence
+of bound magnons. We study the phase diagram of the model numerically by means
+of the density matrix renormalization group technique, and find a good
+agreement with our analytical predictions.",1303.6662v1
+2015-09-23,Four-level N-scheme crossover resonances in Rb saturation spectroscopy in magnetic fields,"We perform saturated absorption spectroscopy on the D$\_2$ line for room
+temperature rubidium atoms immersed in magnetic fields within the 0.05-0.13 T
+range. At those medium-high field values the hyperfine structure in the excited
+state is broken by the Zeeman effect, while in the ground state hyperfine
+structure and Zeeman shifts are comparable. The observed spectra are composed
+by a large number of absorption lines. We identify them as saturated
+absorptions on two-level systems, on three-level systems in a V configuration
+and on four-level systems in a N or double-N configuration where two optical
+transitions not sharing a common level are coupled by spontaneous emission
+decays. We analyze the intensity of all those transitions within a unified
+simple theoretical model. We concentrate our attention on the double-N
+crossovers signals whose intensity is very large because of the symmetry in the
+branching ratios of the four levels. We point out that these structures,
+present in all alkali atoms at medium-high magnetic fields, have interesting
+properties for electromagnetically induced transparency and slow light
+applications.",1509.06978v1
+2016-12-22,Quasilinear quantum magnetoresistance in pressure-induced nonsymmorphic superconductor CrAs,"In conventional metals, modification of electron trajectories under magnetic
+field gives rise to a magnetoresistance that varies quadratically at low field,
+followed by a saturation at high field for closed orbits on the Fermi surface.
+Deviations from the conventional behaviour, e.g. the observation of a linear
+magnetoresistance, or a non-saturating magnetoresistance, have been attributed
+to exotic electron scattering mechanisms. Recently, linear magnetoresistance
+has been observed in many Dirac materials, in which the electron-electron
+correlation is relatively weak. The strongly correlated helimagnet CrAs
+undergoes a quantum phase transition to a nonmagnetic superconductor under
+pressure. Near the magnetic instability, we observe a large and non-saturating
+quasilinear magnetoresistance from the upper critical field to 14 T at low
+temperatures. We show that the quasilinear magnetoresistance arises from an
+intricate interplay between a nontrivial band crossing protected by
+nonsymmorphic crystal symmetry and strong magnetic fluctuations",1612.07480v1
+2018-04-17,Metamagnetism and zero-scale-factor universality in the two-dimensional $J$-$Q$ model,"Using a combination of quantum Monte Carlo and exact methods, we study the
+field-driven saturation transition of the two-dimensional $J$-$Q$ model, in
+which the antiferromagnetic Heisenberg exchange $(J)$ coupling competes with an
+additional four-spin interaction $(Q)$ that favors valence-bond solid order.
+For small values of $Q$, the saturation transition is continuous, and is
+expected to be governed by zero-scale-factor universality at its upper critical
+dimension, with a specific form of logarithmic corrections to scaling (first
+proposed by Sachdev \textit{et al.} [Phys. Rev. B \textbf{50}, 258 (1994)]).
+Our results conform to this expectation, but the logarithmic corrections to
+scaling do not match the form predicted by Sachdev \textit{et al.} We also show
+that the saturation transition becomes first order above a critical coupling
+ratio $(Q/J)_{\rm min}$ and is accompanied by magnetization
+jumps---metamagnetism. We obtain an exact solution for $(Q/J)_{\rm min}$ using
+a high magnetization expansion, and confirm the existence of the magnetization
+jumps beyond this value of coupling using quantum Monte Carlo simulations.",1804.06045v2
+2022-10-14,Modeling the Saturation of the Bell Instability using Hybrid Simulations,"The nonresonant streaming instability (Bell instability) plays a pivotal role
+in the acceleration and confinement of cosmic rays (CRs); yet, the exact
+mechanism responsible for its saturation and the magnitude of the final
+amplified magnetic field have not been assessed from first-principles. Using a
+survey of hybrid simulations (with kinetic ions and fluid electrons), we study
+the evolution of the Bell instability as a function of the parameters of the CR
+population. We find that, at saturation, the magnetic pressure in the amplified
+field is comparable with the initial CR anisotropic pressure, rather than with
+the CR energy flux as previously argued. These results provide a predictive
+prescription for the total magnetic field amplification expected in the many
+astrophysical environments where the Bell instability is important.",2210.08072v2
+2023-09-06,Magnetized Baryonic layer and a novel BPS bound in the gauged-Non-Linear-Sigma-Model-Maxwell theory in (3+1)-dimensions through Hamilton-Jacobi equation,"It is show that one can derive a novel BPS bound for the gauged
+Non-Linear-Sigma-Model (NLSM) Maxwell theory in (3+1) dimensions which can
+actually be saturated. Such novel bound is constructed using Hamilton-Jacobi
+equation from classical mechanics. The configurations saturating the bound
+represent Hadronic layers possessing both Baryonic charge and magnetic flux.
+However, unlike what happens in the more common situations, the topological
+charge which appears naturally in the BPS bound is a non-linear function of the
+Baryonic charge. This BPS bound can be saturated when the surface area of the
+layer is quantized. The far-reaching implications of these results are
+discussed. In particular, we determine the exact relation between the magnetic
+flux and the Baryonic charge as well as the critical value of the Baryonic
+chemical potential beyond which these configurations become thermodynamically
+unstable.",2309.03153v3
+2019-04-15,Improvements of the Longitudinal Magnetic Field Measurement from the Solar Magnetic Field Telescope at Huairou Solar Observing Station,"The weak-field approximation implying linear relationship between Stokes
+$V/I$ and longitudinal magnetic field, $B_{\Vert}$, often suffers from
+saturation observed in strong magnetic field regions such as sunspot umbra. In
+this work, we intend to improve the magnetic field observations carried out by
+the \textit{Solar Magnetic Field Telescope} (SMFT) at Huairou Solar Observing
+Station, China. We propose using non-linear relationship between Stokes $V/I$
+and $B_{\Vert}$ to derive the magnetic field. To determine the form of the
+relationship, we perform a cross-calibration of the observed SMFT data and
+magnetograms provided by the \textit{Helioseismic and Magnetic Imager} on board
+the \textit{Solar Dynamics Observatory}. The algorithm of the magnetic field
+derivation is described in details. We show that using non-linear relationship
+between Stokes $V/I$ and $B_{\Vert}$ allows us to eliminate magnetic field
+saturation inside sunspot umbra. The proposed technique enables one to enhance
+the reliability of the SMFT magnetic field data obtained even long before the
+space-based instrumentation era, since 1987.",1904.07081v7
+2022-07-02,Jets from accretion disk dynamos: consistent quenching modes for dynamo and resistivity,"Astrophysical jets are launched from strongly magnetized systems that host an
+accretion disk surrounding a central object. The origin of the magnetic field,
+which is a key component of the launching process, is still an open question.
+Here we address the question of how the magnetic field required for jet
+launching is generated and maintained by a dynamo process. By carrying out
+non-ideal MHD simulations (PLUTO code), we investigate how the feedback of the
+generated magnetic field on the mean-field dynamo affects the disk and jet
+properties. We find that a stronger quenching of the dynamo leads to a
+saturation of the magnetic field at a lower disk magnetization. Nevertheless,
+we find that, while applying different dynamo feedback models, the overall jet
+properties remain unaffected. We then investigate a feedback model which
+encompasses a quenching of the magnetic diffusivity. Our modeling considers a
+more consistent approach for mean-field dynamo modeling simulations, as the
+magnetic quenching of turbulence should be considered for both, a turbulent
+dynamo and turbulent magnetic diffusivity. We find that, after the magnetic
+field is saturated, the Blandford-Payne mechanism can work efficiently, leading
+to more collimated jets, that move, however, with slower speed. We find strong
+intermittent periods of flaring and knot ejection for low Coriolis numbers. In
+particular, flux ropes are built up and advected towards the inner disk thereby
+cutting off of the inner disk wind, leading to magnetic field reversals,
+reconnection and the emergence of intermittent flares.",2207.00811v1
+2014-10-30,Saturation of Zeldovich Stretch-Twist-Fold Map Dynamos,"Zeldovich's stretch-twist fold (STF) dynamo provided a breakthrough in
+conceptual understanding of fast dynamos, including fluctuation or small scale
+dynamos. We study the evolution and saturation behaviour of two types of
+Baker's map dynamos, which have been used to model Zeldovich's STF dynamo
+process. Using such maps allows one to analyze dynamos at much higher magnetic
+Reynolds numbers $R_M$ as compared to direct numerical simulations. In the
+2-strip map dynamo there is constant constructive folding while the 4-strip map
+dynamo also allows the possibility of field reversal. Incorporating a diffusive
+step parameterised by $R_M$, we find that the magnetic field $B(x)$ is
+amplified only above a critical $R_M=R_{crit} \sim 4$ for both types of
+dynamos. We explore the saturation of these dynamos in 3 ways; by a
+renormalized decrease of the effective $R_M$ (Case I) or due to a decrease in
+the efficiency of field amplification by stretching (Case II), or a combination
+of both effects (Case III). For Case I, we show that $B(x)$ in the saturated
+state, for both types of maps, goes back to the marginal eigenfunction, which
+is obtained for the critical $R_M=R_{crit}$. This is independent of the initial
+$R_M=R_{M0}$. On the other hand in Case II, for the 2-strip map, we show that
+$B(x)$ now saturates preserving the structure of the kinematic eigenfunction.
+Thus the energy is transferred to larger scales in Case I but remains at the
+smallest resistive scales in Case II. For the 4-strip map, the $B(x)$
+oscillates with time, although with a structure similar to the kinematic
+eigenfunction. Interestingly, the saturated state for Case III shows an
+intermediate behaviour, with $B(x)$ now similar to the kinematic eigenfunction
+for an intermediate $R_M=R_{sat}$, with $R_{M0}>R_{sat}>R_{crit}$. These
+saturation properties are akin to the ones discussed in the context of
+fluctuation dynamos.",1410.8455v3
+1999-02-11,A Comparative Study of the Magnetization Process of Two-Dimensional Antiferromagnets,"Plateaux in the magnetization curves of the square, triangular and hexagonal
+lattice spin-1/2 XXZ antiferromagnet are investigated. One finds a zero
+magnetization plateau (corresponding to a spin-gap) on the square and hexagonal
+lattice with Ising-like anisotropies, and a plateau with one third of the
+saturation magnetization on the triangular lattice which survives a small
+amount of easy-plane anisotropy. Here we start with transfer matrix
+computations for the Ising limit and continue with series in the XXZ-anisotropy
+for plateau-boundaries using the groundstates of the Ising limit. The main
+focus is then a numerical computation of the magnetization curves with
+anisotropies in the vicinity of the isotropic situation. Finally, we discuss
+the universality class associated to the asymptotic behaviour of the
+magnetization curve close to saturation, as observed numerically in two and
+higher dimensions.",9902163v1
+2001-08-08,Magnetic anisotropy of the spin ice compound Dy2Ti2O7,"We report magnetization and ac susceptibility of single crystals of the spin
+ice compound Dy2Ti2O7. Saturated moments at 1.8 K along the charasteristic axes
+[100] and [110] agree with the expected values for an effective ferromagnetic
+nearest-neighbor Ising pyrochlore with local <111> anisotropy, where each
+magnetic moment is constrained to obey the `ice-rule'. At high enough magnetic
+fields along the [111] axis, the saturated moment exhibits a beaking of the
+ice-rule; it agrees with the value expected for a three-in one-out spin
+configuration. Assuming the realistic magnetic interaction between Dy ions
+given by the dipolar spin ice model, we completely reproduce the results at 2 K
+by Monte Carlo calculations. However, down to at least 60 mK, we have not found
+any experimental evidence of the long-range magnetic ordering predicted by this
+model to occur at around 180 mK. Instead, we confirm the spin freezing of the
+system below 0.5 K.",0108129v1
+2002-09-04,Magnetization Plateaux in Random Frustrated S=1/2 Heisenberg Chains,"The $S=1/2$ frustrated Heisenberg chains with bond alternation is known to
+exhibit a magnetization plateau at half of the saturation magnetization $\Ms$
+accompanied by the spontanuous translational symmetry breakdown. The effect of
+randomness on the magnetization process of this model is investigated. First we
+consider the mixture of the two kinds of chains both of which possess the
+$\Ms/2$-plateau in the common interval of the magnetization field. The plateau
+at $\Ms/2$ is found to vanish immediately if the randomness is switched on in
+agreement with Totsuka's prediction. The small plateau also appears near the
+saturation field due to the localization of inverted spins around the minority
+bond. On the other hand, if the stronger bond is replaced by the ferromagnetic
+bonds randomly, the randomness induced fractional plateau appears as in the
+nonfrustrated case. The plateau at $\Ms/2$ does not simply vanish but shifts
+and splits into two smaller plateaux. The magnetization on this plateau varies
+nonlinearly with $1-p$. The physical origin of this behavior is explained based
+on the strong coupling picture.",0209074v2
+2003-09-11,Quantum phase diagram of an exactly solved mixed spin ladder,"We investigate the quantum phase diagram of the exactly solved mixed
+spin-(1/2,1) ladder via the thermodynamic Bethe ansatz (TBA). In the absence of
+a magnetic field the model exhibits three quantum phases associated with su(2),
+su(4) and su(6) symmetries. In the presence of a strong magnetic field, there
+is a third and full saturation magnetization plateaux within the strong
+antiferromagnetic rung coupling regime. Gapless and gapped phases appear in
+turn as the magnetic field increases. For weak rung coupling, the fractional
+magnetization plateau vanishs and exhibits new quantum phase transitions.
+However, in the ferromagnetic coupling regime, the system does not have a third
+saturation magnetization plat eau. The critical behaviour in the vicinity of
+the critical points is also derived systematically using the TBA.",0309267v1
+2003-09-18,Magnetization plateaus in frustrated antiferromagnetic quantum spin models,"Plateaus can be observed in the zero-temperature magnetization curve of
+quantum spin systems at rational values of the magnetization. In one dimension,
+the appearance of a plateau is controlled by a quantization condition for the
+magnetization which involves the length of the local spin and the volume of a
+translational unit cell of the ground state. We discuss examples of
+geometrically frustrated quantum spin systems with large (in general unbounded)
+periodicities of spontaneous breaking of translational symmetry in the ground
+state.
+  In two dimensions, we discuss the square, triangular and Kagome lattices
+using exact diagonalization (ED) for up to N=40 sites. For the spin-1/2 XXZ
+model on the triangular lattice we study the nature and stability region of a
+plateau at one third of the saturation magnetization. The Kagome lattice gives
+rise to particularly rich behaviour with several plateaus in the magnetization
+curve and a jump due to local magnon excitations just below saturation.",0309425v2
+2004-01-16,Observation of a Transient Magnetization Plateau in a Quantum Antiferromagnet on the Kagome Lattice,"The magnetization process of an S=1/2 antiferromagnet on the kagome lattice,
+[Cu_3(titmb)_2(OCOCH_3)_6]H_2O {titmb= 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6
+trimethylbenzene} has been measured at very low temperatures in both pulsed and
+steady fields. We have found a new dynamical behavior in the magnetization
+process: a plateau at one third of the saturation magnetization appears in the
+pulsed field experiments for intermediate sweep rates of the magnetic field and
+disappears in the steady field experiments. A theoretical analysis using exact
+diagonalization yields J_1=-19K and J_2=6K, for the nearest neighbor and second
+nearest neighbor interactions, respectively. This set of exchange parameters
+explains the very low saturation field and the absence of the plateau in the
+thermodynamic equilibrium as well as the two-peak feature in the magnetic heat
+capacity. Supported by numerical results we argue that a dynamical order by
+disorder phenomenon could explain the transient appearance of the 1/3 plateau
+in pulsed field experiments.",0401288v2
+2006-03-29,A new type of bound magnetic polaron state: the formation of long-range spin distortions,"The structure of bound magnetic polarons in an antiferromagnetic matrix is
+studied in the framework of two-dimensional (2D) and three-dimensional (3D)
+Kondo-lattice models in the double exchange limit (J_H >> t). The conduction
+electron is bound by a nonmagnetic donor impurity and forms a ferromagnetic
+core of the size about the electron localization length (bound magnetic
+polaron). We find that the magnetic polaron produces rather long-range extended
+spin distortions of the antiferromagnetic background around the core. In a wide
+range of distances, these distortions decay as 1/r^2 and 1/r^4 in 2D and 3D
+cases, respectively. In addition, the magnetization of the core is smaller than
+its saturation value. Such a magnetic polaron state is favorable in energy in
+comparison to usually considered one (saturated core without extended
+distortions).",0603798v2
+2007-01-12,Fully developed turbulent dynamo at low magnetic Prandtl numbers,"We investigate the dynamo problem in the limit of small magnetic Prandtl
+number ($\Pm$) using a shell model of magnetohydrodynamic turbulence. The model
+is designed to satisfy conservation laws of total energy, cross helicity and
+magnetic helicity in the limit of inviscid fluid and null magnetic diffusivity.
+The forcing is chosen to have a constant injection rate of energy and no
+injection of kinetic helicity nor cross helicity. We find that the value of the
+critical magnetic Reynolds number ($\Rm$) saturates in the limit of small
+$\Pm$. Above the dynamo threshold we study the saturated regime versus $\Rm$
+and $\Pm$. In the case of equipartition, we find Kolmogorov spectra for both
+kinetic and magnetic energy except for wave numbers just below the resistive
+scale. Finally the ratio of both dissipation scales (viscous to resistive)
+evolves as $\Pm^{-3/4}$ for $\Pm < 1$",0701152v1
+2012-07-24,Colossal non-saturating linear magnetoresistance in two-dimensional electron systems at a GaAs/AlGaAs heterointerface,"Engineering devices with a large electrical response to magnetic field is of
+fundamental importance for a range of applications such as magnetic field
+sensing and magnetic read-heads. We show that a colossal non-saturating linear
+magnetoresistance (NLMR) arises in two-dimensional electron systems hosted in a
+GaAs/AlGaAs heterostructure in the strongly insulating regime. When operated at
+high source-drain bias, the magnetoresistance of our devices increases almost
+linearly with magnetic field reaching nearly 10,000% at 8 Tesla, thus
+surpassing many known non-magnetic materials that exhibit giant NLMR. The
+temperature dependence and mobility analysis indicate that the NLMR has a
+purely classical origin, driven by nanoscale inhomogeneities. A large NLMR
+combined with small device dimensions makes these systems a new and attractive
+candidate for on-chip magnetic field sensing.",1207.5709v2
+2013-02-20,Periodic magnetization structures generated by transverse spin-current in magnetic nanowires,"Magnetization behavior of long nanowires with square cross-section under
+influence of strong perpendicular spin-polarized current is studied
+theoretically. The study is based on Landau-Lifshitz-Slonczewski phenomenology.
+In the no current case the wire is magnetized uniformly along its axis. For
+small currents the wire magnetization remains uniform but it inclines with
+respect to the wire axis within the plane perpendicular to the current
+direction. With the current increasing the inclination angle increases up to
+the maximum value $\pi/4$. Further current increase leads either to saturation
+or to stable periodic multidomain structure depending on the wire thickness.
+For thick wires a hysteresis is observed in the saturation process under the
+action of current. All critical parameters of the current induced magnetization
+behavior are determined theoretically. The study is carried out both
+analytically and using micromagnetic simulations.",1302.4899v1
+2013-06-18,"Modification in structural, dielectric and magnetic properties of La and Nd co-substituted epitaxial BiFeO3 thin films","The influence of La and Nd co-substitution on the structural and magnetic
+properties of BiFeO3 (BFO) thin films was examined. Epitaxial thin films of
+pure and, La and Nd co-doped BFO on the SrRuO3 buffered single crystal SrTiO3
+(001) substrate were deposited using pulsed laser deposition. The structural
+change in co doped La and Nd BFO thin films which was caused by the changes of
+force constant in the crystal lattice induced by ionic radii mismatch was
+investigated. Raman spectroscopy studies manifest the structural change in
+doped BFO films from rhombohedral to monoclinic distorted phase which is
+induced by the co substitution of La and Nd. Room temperature magnetic
+hysteresis curves indicated that saturation magnetization is enhanced in the
+doped film with saturation magnetization of ~20 emu/cm3. The dielectric and
+magnetic properties are effectively improved in BLNFO films compared to pure
+BFO thin films.",1306.4214v1
+2013-12-26,Where is magnetic anisotropy field pointing to?,"The desired result of magnetic anisotropy investigations is the determination
+of value(s) of various anisotropy constant(s). This is sometimes difficult,
+especially when the precise knowledge of saturation magnetization is required,
+as it happens in ferromagnetic resonance (FMR) studies. In such cases we
+usually resort to `trick' and fit our experimental data to the quantity called
+\emph{anisotropy field}, which is strictly proportional to the ratio of the
+searched anisotropy constant and saturation magnetization. Yet, this quantity
+is scalar, simply a number, and is therefore of little value for modeling or
+simulations of the magnetostatic or micromagnetic structures. Here we show how
+to `translate' the values of magnetic anisotropy constants into the complete
+vector of magnetic anisotropy field. Our derivation is rigorous and covers the
+most often encountered cases, from uniaxial to cubic anisotropy.",1312.7130v1
+2020-06-08,Pre-saturation phase in the frustrated ferro-antiferromagnet Pb$_2$VO(PO$_4$)$_2$,"Magnetization, magnetic torque, neutron diffraction and NMR experiments are
+used to map out the $H$$-$$T$ phase diagram of the prototypical
+quasi-two-dimensional ferro-antiferromagnet Pb$_2$VO(PO$_4$)$_2$ in magnetic
+fields up to 27 T. When the field is applied perpendicular to the axis of
+magnetic anisotropy, a new magnetic state emerges through a discontinuous
+transition and persists in a narrow field range just below saturation. The
+measured NMR spectra suggest a complex and possibly incommensurate magnetic
+order in that regime.",2006.04592v1
+2021-04-16,Magnetic field amplification by a nonlinear electron streaming instability,"Magnetic field amplification by relativistic streaming plasma instabilities
+is central to a wide variety of high-energy astrophysical environments as well
+as to laboratory scenarios associated with intense lasers and electron beams.
+We report on a new secondary nonlinear instability which arises for
+relativistic dilute electron beams after the saturation of the linear Weibel
+instability. This instability grows due to the transverse magnetic pressure
+associated with the beam current filaments, which cannot be quickly neutralized
+due to the inertia of background ions. We show that it can amplify the magnetic
+field strength and spatial scale by orders of magnitude, leading to large-scale
+plasma cavities with strong magnetic field and to very efficient conversion of
+the beam kinetic energy into magnetic energy. The instability growth rate,
+saturation level, and scale length are derived analytically and shown to be in
+good agreement with fully-kinetic simulations.",2104.08246v1
+2022-01-27,Simultaneous measurement of the exchange parameter and saturation magnetization using propagating spin waves,"The exchange interaction in ferromagnetic ultra-thin films is a critical
+parameter in magnetization-based storage and logic devices, yet the accurate
+measurement of it remains a challenge. While a variety of approaches are
+currently used to determine the exchange parameter, each has its limitations,
+and good agreement among them has not been achieved. To date, neutron
+scattering, magnetometry, Brillouin light scattering, spin-torque ferromagnetic
+resonance spectroscopy, and Kerr microscopy have all been used to determine the
+exchange parameter. Here we present a novel method that exploits the wavevector
+selectivity of Brillouin light scattering to measure the spin wave dispersion
+in both the backward volume and Damon-Eshbach orientations. The exchange,
+saturation magnetization, and magnetic thickness are then determined by a
+simultaneous fit of both dispersion branches with general spin wave theory
+without any prior knowledge of the thickness of a magnetic ""dead layer"". In
+this work, we demonstrate the strength of this technique for ultrathin metallic
+films, typical of those commonly used in industrial applications for magnetic
+random-access memory.",2201.11270v1
+2022-05-03,Robustness of binary stochastic neurons implemented with low barrier nanomagnets made of dilute magnetic semiconductors,"Binary stochastic neurons (BSNs) are excellent hardware accelerators for
+machine learning. A popular platform for implementing them are low- or
+zero-energy barrier nanomagnets possessing in-plane magnetic anisotropy (e.g.
+circular disks or quasi-elliptical disks with very small eccentricity).
+Unfortunately, small geometric variations in the lateral shapes of such
+nanomagnets can produce large changes in the BSN response times if the
+nanomagnets are made of common metallic ferromagnets (Co, Ni, Fe) with large
+saturation magnetization. Additionally, the response times are also very
+sensitive to initial conditions. Here, we show that if the nanomagnets are made
+of dilute magnetic semiconductors with much smaller saturation magnetization,
+then the variability in their response times (due to shape variations and
+variation in the initial condition) is drastically suppressed. This
+significantly reduces the device-to-device variation, which is a serious
+challenge for large scale neuromorphic systems.",2205.01793v1
+2022-08-19,Modulation of magnetic property of double-perovskite La2MnCoO6 films by controlling B-antisite disorder,"The predicted physical properties of double perovskites have usually been
+compromised by their intrinsic B-antisite (AS) disorder effect, but the
+relationship between them is still unclear for the La2MnCoO6 (LMCO) system.
+This study focuses on controlling the AS disorder and quantitatively reveals
+correlations with magnetic and electronic states in epitaxial LMCO films grown
+on (111) SrTiO3 substrates. The AS fraction was precisely controlled by tuning
+the growth conditions as evaluated from saturation magnetization and x-ray
+reflection profiles. The saturation magnetization at 5 K decreased linearly
+from 6 uB per formula unit by 50% as the AS fraction increased from 0
+(perfectly ordered) to 0.5 (fully disordered). The x-ray absorption
+spectroscopy revealed that valence states of Mn and Co were 4+ (3d^3) and 2+
+(3d^7), respectively, regardless of AS fraction. A local-spin-moment model is
+proposed to explain the net magnetizations with and without AS disorder and
+Mn/Co valence states, suggesting that only the rearrangement of local spin
+moment of Co at the antisite plays a key role in tuning the magnetism in this
+LMCO system.",2208.09166v1
+2023-07-10,Increasing Flips per Second and Speed of p-Computers by Using Dilute Magnetic Semiconductors to Implement Binary Stochastic Neurons,"Probabilistic computing with binary stochastic neurons (BSN) implemented with
+low- or zero-energy barrier nanoscale ferromagnets (LBMs) possessing in-plane
+magnetic anisotropy has emerged as an efficient paradigm for solving
+computationally hard problems. The fluctuating magnetization of an LBM at room
+temperature encodes a p-bit which is the building block of a BSN. Its only
+drawback is that the dynamics of common (transition metal) ferromagnets are
+relatively slow and hence the number of uncorrelated p-bits that can be
+generated per second - the so-called ""flips per second"" (fps) - is
+insufficient, leading to slow computational speed in autonomous co-processing
+with p-computers. Here, we show that a simple way to increase fps is to replace
+commonly used ferromagnets (e.g. Co, Fe, Ni), which have large saturation
+magnetization Ms, with a dilute magnetic semiconductor like GaMnAs with much
+smaller saturation magnetization. The smaller Ms reduces the energy barrier
+within the LBM and increases the fps significantly. It also offers other
+benefits such as increased packing density for increased parallelization and
+reduced device to device variation. This provides a way to realize the hardware
+acceleration and energy efficiency promise of p-computers.",2307.04663v1
+2023-08-15,"Reflective, polarizing, and magnetically soft amorphous Fe/Si multilayer neutron optics with isotope-enriched 11B4C inducing atomically flat interfaces","The utilization of polarized neutrons is of great importance in scientific
+disciplines spanning materials science, physics, biology, and chemistry.
+Polarization analysis offers insights into otherwise unattainable sample
+information such as magnetic domains and structures, protein crystallography,
+composition, orientation, ion-diffusion mechanisms, and relative location of
+molecules in multicomponent biological systems. State-of-the-art multilayer
+polarizing neutron optics have limitations, particularly low specular
+reflectivity and polarization at higher scattering vectors/angles, and the
+requirement of high external magnetic fields to saturate the polarizer
+magnetization. Here, we show that by incorporating 11B4C into Fe/Si
+multilayers, amorphization and smooth interfaces can be achieved, yielding
+higher neutron reflectivity, less diffuse scattering and higher polarization.
+Magnetic coercivity is eliminated, and magnetic saturation can be reached at
+low external fields (>2 mT). This approach offers prospects for significant
+improvement in polarizing neutron optics, enabling; nonintrusive positioning of
+the polarizer, enhanced flux, increased data accuracy, and further
+polarizing/analyzing methods at neutron scattering facilities.",2308.07630v1
+2023-11-13,Translational symmetry broken magnetization plateau of the S=1 antiferromagnetic Heisenberg chain with competing anisotropies,"We investigate the S=1 antiferromagnetic quantum spin chain with the exchange
+and single-ion anisotropies in a magnetic field, using the numerical exact
+diagonalization of finite-size clusters, the level spectroscopy analysis, and
+the density matrix renormalization group (DMRG) method. It is found that a
+translational symmetry broken magnetization plateau possibly appears at the
+half of the saturation magnetization, when the anisotropies compete with each
+other. The level spectroscopy analysis gives the phase diagram at half the
+saturation magnetization. The DMRG calculation presents the magnetization
+curves for some typical parameters and clarifies the spin structure in the
+plateau phase.",2311.07123v1
+2023-12-15,Hyperbolic Bloch points in ferrimagnetic exchange spring,"Bloch points in magnetic materials are attractive entities in view of
+magnetic information transport. Here, Bloch point configuration has been
+investigated and experimentally determined in a magnetic trilayer
+($Gd_{12}Co_{88}/Nd_{17}Co_{83}/Gd_{24}Co_{76}$) with carefully adjusted
+composition within the ferrimagnetic $Gd_{x}Co_{1-x}$ alloys in order to
+engineer saturation magnetization, exchange length, and interlayer couplings
+(ferromagnetic vs antiferromagnetic). X-ray vector magnetic tomography has
+allowed us to determine experimentally Bloch point polarity (related to
+topological charge) and Bloch point helicity ${\gamma}$ (determined by
+magnetostatic energy). At the bottom layer (close to the ferromagnetic
+interface), Bloch points adopt a standard circulating configuration with
+helicity ${\gamma}$ close to ${\pi}/2$. Within the top layer (with much lower
+saturation magnetization), Bloch points nucleate within a Neel-like exchange
+spring domain wall created by the antiferromagnetic coupling and adopt an
+uncommon hyperbolic configuration, characterized by much larger helicity
+angles. Our results indicate a path for Bloch point engineering in future
+applications adjusting material parameters and domain wall characteristics.",2312.09836v1
+2014-01-31,Understanding nonlinear saturation in zonal-flow-dominated ion temperature gradient turbulence,"We propose a quantitative model of ion temperature gradient driven turbulence
+in toroidal magnetized plasmas. In this model, the turbulence is regulated by
+zonal flows, i.e. mode saturation occurs by a zonal-flow-mediated energy
+cascade (""shearing""), and zonal flow amplitude is controlled by nonlinear
+decay. Our model is tested in detail against numerical simulations to confirm
+that both its assumptions and predictions are satisfied. Key results include
+(1) a sensitivity of the nonlinear zonal flow response to the energy content of
+the linear instability, (2) a persistence of zonal-flow-regulated saturation at
+high temperature gradients, (3) a physical explanation of the nonlinear
+saturation process in terms of secondary and tertiary instabilities, and (4)
+dependence of heat flux in terms of dimensionless parameters.",1401.8140v3
+2016-12-09,Bulk Saturable absorption in Topological Insulator thin Films,"We present nonlinear optical absorption properties of pulsed laser deposited
+thin films of topological insulator (TI), Bi2Se3 on quartz substrate, using
+open aperture Z - scan technique. The saturable intensity of as-deposited thin
+films has been found remarkably improved by an order of magnitude compared to
+the values reported earlier in the literature. Past results from the literature
+are inconclusive in establishing whether the saturable absorption is coming
+from surface states or the bulk. Specifically designed experiments with
+magnetically doped TI samples allow us to attribute the saturable absorption
+characteristic of TI to the bulk states. Detailed experimental procedures and
+possible explanation of observed results have been discussed.",1612.02977v1
+2017-07-17,Finite-temperature correlations in a quantum spin chain near saturation,"Inelastic neutron-scattering and finite-temperature density matrix
+renormalization group (DMRG) calculations are used to investigate the spin
+excitation spectrum of the $S=1/2$ Heisenberg spin chain compound
+K$_2$CuSO$_4$Cl$_2$ at several temperatures in a magnetic field near
+saturation. Critical correlations characteristic of the predicted $z=2$, $d=1$
+quantum phase transition occurring at saturation are shown to be consistent
+with the observed neutron spectra. The data is well described with a scaling
+function computed using a free fermion description of the spins, valid close to
+saturation, and the corresponding scaling limits. One of the most prominent
+non-universal spectral features of the data is a novel thermally activated
+longitudinal mode that remains underdamped across most of the Brillouin zone.",1707.05243v2
+2019-11-04,Effect of the electron redistribution on the nonlinear saturation of Alfvén eigenmodes and the excitation of zonal flows,"Numerical simulations of Alfv\'en modes (AM) driven by energetic particles
+are performed with the GK global PIC code ORB5. A reversed shear equilibrium
+magnetic field is adopted. A simplified configuration with circular flux
+surfaces and large aspect ratio is considered. The nonlinear saturation of
+beta-induced Alfv\'en eigenmodes (BAE) is investigated. The roles of the
+wave-particle nonlinearity of the different species, i.e. thermal ions,
+electrons, and energetic ions are described, in particular for their role in
+the saturation of the BAE and the generation of zonal flows. The nonlinear
+redistribution of the electron population is found to be important in
+increasing the BAE saturation level and the zonal flow amplitude.",1911.01243v1
+2022-12-13,Assessing the saturation of Krylov complexity as a measure of chaos,"Krylov complexity is a novel approach to study how an operator spreads over a
+specific basis. Recently, it has been stated that this quantity has a long-time
+saturation that depends on the amount of chaos in the system. Since this
+quantity not only depends on the Hamiltonian but also on the chosen operator,
+in this work we study the level of generality of this hypothesis by studying
+how the saturation value varies in the integrability to chaos transition when
+different operators are expanded. To do this, we work with an Ising chain with
+a transverse-longitudinal magnetic field and compare the saturation of the
+Krylov complexity with the standard spectral measure of quantum chaos. Our
+numerical results show that the usefulness of this quantity as a predictor of
+the chaoticity is strongly dependent on the chosen operator.",2212.06619v2
+2024-01-14,Axion Detection with Quantum Hall Effect,"Plateau-plateau transition in integer quantum Hall effect is a phase
+transition between metal and insulator. The behavior how the width $\Delta B$
+of the transition changes with temperature and frequency of radiations imposed
+has been explored extensively. It decreases with the decrease of temperature
+and frequency, but saturates at critical temperature or frequency. We have
+recently discussed the effect of axion dark matter on the saturation. The axion
+generates radiations under strong magnetic field in the experiment of quantum
+Hall effect. The radiations play a similar role to the one of radiations
+imposed externally. In this paper we discuss in detail how the width behaves in
+temperature and frequency under the effect of axion dark matter. We show that
+the axion effect can be observable in low temperature roughly below $100$mK.
+According to our detailed analysis of the saturation, we find that critical
+frequency of saturation observed in previous experiment strongly suggests axion
+mass $m_a=(0.95\sim 0.99)\times 10^{-5}$eV.",2401.07180v2
+1999-11-03,Magnetic properties of submicron Co islands and their use as artificial pinning centers,"We report on the magnetic properties of elongated submicron magnetic islands
+and their influence on a superconducting film. The magnetic properties were
+studied by magnetization hysteresis loop measurements and scanning-force
+microscopy. In the as-grown state, the islands have a magnetic structure
+consisting of two antiparallel domains. This stable domain configuration has
+been directly visualized as a 2x2-checkerboard pattern by magnetic-force
+microscopy. In the remanent state, after magnetic saturation along the easy
+axis, all islands have a single-domain structure with the magnetic moment
+oriented along the magnetizing field direction. Periodic lattices of these Co
+islands act as efficient artificial pinning arrays for the flux lines in a
+superconducting Pb film deposited on top of the Co islands. The influence of
+the magnetic state of the dots on their pinning efficiency is investigated in
+these films, before and after the Co dots are magnetized.",9911034v1
+2005-10-21,Magnetostrictive hysteresis of TbCo/CoFe multilayers and magnetic domains,"Magnetic and magnetostrictive hysteresis loops of TbCo/CoFe multilayers under
+field applied along the hard magnetization axis are studied using vectorial
+magnetization measurements, optical deflectometry and magneto optical Kerr
+microscopy. Even a very small angle misalignment between hard axis and magnetic
+field direction is shown to drastically change the shape of magnetization and
+magnetostrictive torsion hysteresis loops. Two kinds of magnetic domains are
+revealed during the magnetization: big regions with opposite rotation of
+spontaneous magnetization vector and spontaneous magnetic domains which appear
+in a narrow field interval and provide an inversion of this rotation.
+  We show that the details of the hysteresis loops of our exchange-coupled
+films can be described using the classical model of homogeneous magnetization
+rotation of single uniaxial films and the configuration of observed domains.
+The understanding of these features is crucial for applications (for MEMS or
+microactuators) which benefit from the greatly enhanced sensitivity near the
+point of magnetic saturation at the transverse applied field.",0510568v1
+2019-04-12,The magnetic structure factor of correlated moments in small-angle neutron scattering,"The interplay between structural and magnetic properties of nanostructured
+magnetic materials allows to realize unconventional magnetic effects, which
+results in a demand for experimental techniques to determine the magnetization
+profile with nanoscale resolution. Magnetic small-angle neutron scattering
+(SANS) probes both the chemical and magnetic nanostructure and is thus a
+powerful technique e.g. for the characterization of magnetic nanoparticles.
+Here, we show that the conventionally used particle-matrix approach to describe
+SANS of magnetic particle assemblies, however, leads to a flawed
+interpretation. As remedy, we provide general expressions for the
+field-dependent 2D magnetic SANS cross-section of correlated moments. It is
+shown that for structurally disordered ensembles the magnetic structure factor
+is in general, and contrary to common assumptions, (i) anisotropic also in zero
+field, and (ii) that even in saturation the magnetic structure factor deviates
+from the nuclear one. These theoretical predictions explain qualitatively the
+intriguing experimental, polarized SANS data of an ensemble of dipolar-coupled
+iron oxide nanoparticles.",1904.06243v3
+2021-08-26,Magnetic design study of coil-dominated superconducting quadrupole magnets based on racetrack coils,"Several coil structures have been used in accelerator superconducting
+quadrupole magnets, and cos2{\theta} quadrupole magnets are the most mature in
+theoretical research and engineering applications. However, the cos2{\theta}
+quadrupole magnet has a complicated coil structure, especially at the end of
+the coil, which makes it difficult to apply strain-sensitive high-temperature
+superconductors. Racetrack quadrupole magnets are friendly to high-temperature
+superconductors. Field strength of iron-dominated racetrack magnets is limited
+by the magnetic saturation of the iron poles. Therefore, coil-dominated
+racetrack quadrupole magnets with simple geometry have become the focus of our
+research. In this paper, analytical expressions of the magnetic field harmonics
+related to racetrack quadrupole coil parameters are obtained. These expressions
+are used to find the solution of coil geometry parameters with field harmonics
+on the order of 10-4. Then, examples are given to build ideal quadrupole model
+and verify the theoretical formulas. Next, the design and optimization of
+example racetrack quadrupole magnets are completed in ROXIE. Finally, the
+advantages and disadvantages of the racetrack coils and the cos2{\theta} coils
+are compared and discussed.",2108.11643v1
+2001-11-29,Magnetic helicity in stellar dynamos: new numerical experiments,"The theory of large scale dynamos is reviewed with particular emphasis on the
+magnetic helicity constraint in the presence of closed and open boundaries. In
+the presence of closed or periodic boundaries, helical dynamos respond to the
+helicity constraint by developing small scale separation in the kinematic
+regime, and by showing long time scales in the nonlinear regime where the scale
+separation has grown to the maximum possible value. A resistively limited
+evolution towards saturation is also found at intermediate scales before the
+largest scale of the system is reached. Larger aspect ratios can give rise to
+different structures of the mean field which are obtained at early times, but
+the final saturation field strength is still decreasing with decreasing
+resistivity. In the presence of shear, cyclic magnetic fields are found whose
+period is increasing with decreasing resistivity, but the saturation energy of
+the mean field is in strong super-equipartition with the turbulent energy. It
+is shown that artificially induced losses of small scale field of opposite sign
+of magnetic helicity as the large scale field can, at least in principle,
+accelerate the production of large scale (poloidal) field. Based on mean field
+models with an outer potential field boundary condition in spherical geometry,
+we verify that the sign of the magnetic helicity flux from the large scale
+field agrees with the sign of alpha. For solar parameters, typical magnetic
+helicity fluxes lie around 10^{47} Mx^2 per cycle.",0111567v3
+2003-01-22,Understanding Helical Magnetic Dynamo Spectra with a Nonlinear Four-Scale Theory,"Recent MHD dynamo simulations for magnetic Prandtl number $>1$ demonstrate
+that when MHD turbulence is forced with sufficient kinetic helicity, the
+saturated magnetic energy spectrum evolves from having a single peak below the
+forcing scale to become doubly peaked with one peak at the system (=largest)
+scale and one at the forcing scale. The system scale field growth is well
+modeled by a recent nonlinear two-scale nonlinear helical dynamo theory in
+which the system and forcing scales carry magnetic helicity of opposite sign.
+But a two-scale theory cannot model the shift of the small-scale peak toward
+the forcing scale. Here I develop a four-scale helical dynamo theory which
+shows that the small-scale helical magnetic energy first saturates at very
+small scales, but then successively saturates at larger values at larger
+scales, eventually becoming dominated by the forcing scale. The transfer of the
+small scale peak to the forcing scale is completed by the end of the kinematic
+growth regime of the large scale field, and does not depend on magnetic
+Reynolds number $R_M$ for large $R_M$. The four-scale and two-scale theories
+subsequently evolve almost identically, and both show significant field growth
+on the system and forcing scales that is independent of $R_M$. In the present
+approach, the helical and nonhelical parts of the spectrum are largely
+decoupled. Implications for fractionally helical turbulence are discussed.",0301432v2
+2010-10-04,Defects induced ferromagnetism in Mn doped ZnO,"Single phase Mn doped (2 at %) ZnO samples have been synthesized by
+solid-state reaction technique. Before the final sintering at 500 C, the mixed
+powders have been milled for different milling periods (6, 24, 48 and 96
+hours). The grain sizes of the samples are very close to each other (~ 32 \pm 4
+nm). However, the defective state of the samples is different from each other
+as manifested from the variation of magnetic properties and electrical
+resistivity with milling time. All the samples have been found to be
+ferromagnetic with clear hysteresis loops at room temperature. The maximum
+value for saturation magnetization (0.11 {\mu}_B / Mn atom) was achieved for 96
+hours milled sample. Electrical resistivity has been found to increase with
+increasing milling time. The most resistive sample bears the largest saturation
+magnetization. Variation of average positron lifetime with milling time bears a
+close similarity with that of the saturation magnetization. This indicates the
+key role played by open volume vacancy defects, presumably zinc vacancies near
+grain surfaces, in inducing ferromagnetic order in Mn doped ZnO. To attain
+optimum defect configuration favorable for ferromagnetism in this kind of
+samples proper choice of milling period and annealing conditions is required.",1010.0547v1
+2012-11-02,Direct Observation of Giant Saturation Magnetization in Fe16N2,"Magnetic materials with giant saturation magnetization have been a holy grail
+for magnetic researchers and condensed matter physicists for decades because of
+its great scientific and technological impacts. As described by the famous
+Slater-Pauling curve the material with highest Ms is the Fe65Co35 alloy. This
+was challenged in 1972 by a report on the compound Fe16N2 with Ms much higher
+than that of Fe65Co35. Following this claim, there have been enormous efforts
+to reproduce this result and to understand the magnetism of this compound.
+However, the reported Ms by different groups cover a broad range, mainly due to
+the unavailability of directly assessing Ms in Fe16N2. In this article, we
+report a direct observation of the giant saturation magnetization up to 2500
+emu/cm3 using polarized neutron reflectometry (PNR) in epitaxial constrained
+Fe16N2 thin films prepared using a low-energy and surface-plasma-free
+sputtering process. The observed giant Ms is corroborated by a previously
+proposed Cluster + Atom model, the characteristic feature of which, namely, the
+directional charge transfer is evidenced by polarization-dependent x-ray
+absorption near edge spectroscopy (XANES).",1211.0553v1
+2012-11-26,Nonlinear Evolution of the Radiation-Driven Magneto-Acoustic Instability (RMI),"We examine the nonlinear development of unstable magnetosonic waves driven by
+a background radiative flux -- the Radiation-Driven Magneto-Acoustic
+Instability (RMI, a.k.a. the ""photon bubble"" instability). The RMI may serve as
+a persistent source of density, radiative flux, and magnetic field fluctuations
+in stably-stratified, optically-thick media. The conditions for instability are
+present in a variety of astrophysical environments, and do not require the
+radiation pressure to dominate or the magnetic field to be strong. Here we
+numerically study the saturation properties of the RMI, covering three orders
+of magnitude in the relative strength of radiation, magnetic field, and gas
+energies. Two-dimensional, time-dependent radiation-MHD simulations of local,
+stably-stratified domains are conducted with Zeus-MP in the optically-thick,
+highly-conducting limit. Our results confirm the theoretical expectations of
+Blaes and Socrates (2003) in that the RMI operates even in gas
+pressure-dominated environments that are weakly magnetized. The saturation
+amplitude is a monotonically increasing function of the ratio of radiation to
+gas pressure. Keeping this ratio constant, we find that the saturation
+amplitude peaks when the magnetic pressure is comparable to the radiation
+pressure. We discuss the implications of our results for the dynamics of
+magnetized stellar envelopes, where the RMI should act as a source of
+sub-photospheric perturbations.",1211.6107v2
+2017-10-13,Possible quadrupolar nematic phase in the frustrated spin chain LiCuSbO$_4$: an NMR investigation,"The frustrated one-dimensional (1D) quantum magnet LiCuSbO$_4$ is one rare
+realization of the $J_1-J_2$ spin chain model with an easily accessible
+saturation field, formerly estimated to 12~T. Exotic multipolar nematic phases
+were theoretically predicted in such compounds just below the saturation field,
+but without unambiguous experimental observation so far. In this paper we
+present extensive experimental research of the compound in the wide temperature
+(30mK$-$300K) and field (0$-$13.3T) range by muon spin rotation ($\mu$SR),
+$^7$Li nuclear magnetic resonance (NMR) and magnetic susceptibility (SQUID).
+$\mu$SR experiments in zero magnetic field demonstrate the absence of long
+range 3D ordering down to 30mK. Together with former heat capacity data [S.E.
+Dutton \emph{et al}, Phys. Rev. Lett. 108, 187206 (2012)], magnetic
+susceptibility measurements suggest short range correlated vector chiral phase
+in the field range $0-4$T. In the intermediate field values (5$-$12T), the
+system enters in a 3D ordered spin density wave phase with 0.75$\mu_B$ per
+copper site at lowest temperatures (125mK), estimated by NMR. At still higher
+field, the magnetization is found to be saturated above 13T where the spin
+lattice $T_1^{-1}$ relaxation reveals a spin gap estimated to 3.2(2)K. We
+narrow down the possibility of observing a multipolar nematic phase to the
+range 12.5$-$13T.",1710.05004v1
+2018-06-14,Selection of axial dipole from a seed magnetic field in rapidly rotating dynamo models,"In this study, we investigate preferences of dipolar magnetic structure from
+a seed magnetic field in the rapidly rotating spherical shell dynamo models. In
+this study, we set up a realistic model to show the effect of the Lorentz force
+in the polarity selection. The important results that has come out from our
+study is that the magnetic field acts on the flow much before the saturation.
+Our study suggests that the growth of the magnetic field is not a kinematic
+effect as one might think off, rather a dynamic effect. This dynamic effect
+grows as the field generated with time and finally brings the saturation to the
+dynamo action. Previous studies show that Lorentz force effect the flow when
+Elsasser number more or less 1 and the studies were focused on the saturation
+by looking at the time-averaged quantities. However, in this study, we show a
+clear effect of the Lorentz force even at Elsasser number of $0.3-0.4$. To show
+the effect of the Lorentz force, we did two different simulations, one is a
+nonlinear model and another is kinematic model and shows that how a magnetic
+field can change the flow structure and by doing that the generated field
+changes, while this kind of behavior is not observed in kinematic dynamo
+models. This study shows a scale dependent behaviour of the kinetic helicity at
+two different spectral range.",1806.05368v1
+2018-12-21,Dynamo saturation down to vanishing viscosity: strong-field and inertial scaling regimes,"We present analytical examples of fluid dynamos that saturate through the
+action of the Coriolis and inertial terms of the Navier-Stokes equation. The
+flow is driven by a body force and is subject to global rotation and uniform
+sweeping velocity. The model can be studied down to arbitrarily low viscosity
+and naturally leads to the strong-field scaling regime for the magnetic energy
+produced above threshold: the magnetic energy is proportional to the global
+rotation rate and independent of the viscosity. Depending on the relative
+orientations of global rotation and large-scale sweeping, the dynamo
+bifurcation is either supercritical or subcritical. In the supercritical case,
+the magnetic energy follows the scaling-law for supercritical strong-field
+dynamos predicted on dimensional grounds by Petrelis & Fauve (2001). In the
+subcritical case, the system jumps to a finite-amplitude dynamo branch. The
+magnetic energy obeys a magneto-geostrophic scaling-law (Roberts & Soward
+1972), with a turbulent Elsasser number of the order of unity, where the
+magnetic diffusivity of the standard Elsasser number appears to be replaced by
+an eddy diffusivity. In the absence of global rotation, the dynamo bifurcation
+is subcritical and the saturated magnetic energy obeys the equipartition
+scaling regime. We consider both the vicinity of the dynamo threshold and the
+limit of large distance from threshold to put these various scaling behaviors
+on firm analytical ground.",1812.09166v1
+2021-07-23,Wrinkling of soft magneto-active plates,"Coupled magneto-mechanical wrinkling has appeared in many scenarios of
+engineering and biology. Hence, soft magneto-active (SMA) plates buckle when
+subject to critical uniform magnetic field normal to their wide surface. Here,
+we provide a systematic analysis of the wrinkling of SMA plates subject to an
+in-plane mechanical load and a transverse magnetic field?. We consider two
+loading modes: plane-strain loading and uni-axial loading, and two models of
+magneto-sensitive plates: the neo-Hookean ideal magneto-elastic model and the
+neo-Hookean magnetization saturation Langevin model. Our analysis relies on the
+theory of nonlinear magneto-elasticity and the associated linearized theory for
+superimposed perturbations. We derive the Stroh formulation of the governing
+equations of wrinkling, and combine it with the surface impedance method to
+obtain explicitly the bifurcation equations identifying the onset of symmetric
+and antisymmetric wrinkles. We also obtain analytical expressions of
+instability in the thin- and thick-plate limits. For thin plates, we make the
+link with classical Euler buckling solutions. We also perform an exhaustive
+numerical analysis to elucidate the effects of loading mode, load amplitude,
+and saturation magnetization on the nonlinear static response and bifurcation
+diagrams. We find that antisymmetric wrinkling modes always occur before
+symmetric modes. Increasing the pre-compression or heightening the magnetic
+field has a destabilizing effect for SMA plates, while the saturation
+magnetization enhances their stability. We show that the Euler buckling
+solutions are a good approximation to the exact bifurcation curves for thin
+plates.",2107.11093v1
+2021-10-28,On the Potential of Fourier-Encoded Saturation Transfers for Sensitizing Solid-State Magic-Angle Spinning NMR Experiments,"Chemical exchange saturation transfer (CEST) is widely used for enhancing the
+solution NMR signatures of magnetically-dilute spin pools; in particular
+species at low concentrations undergoing chemical exchanges with an abundant
+spin pool. CEST's main feature involves encoding and then detecting the weak
+NMR signals of the magnetically dilute spin pools on a magnetically abundant
+spin pool of much easier detection - for instance the protons of H2O. Inspired
+by this method, we propose and exemplify a methodology to enhance the
+sensitivity of magic-angle spinning (MAS) solid-state NMR spectra. Our proposal
+uses the abundant 1H reservoir arising in organic solids as the magnetically
+abundant spin pool, and relies on proton spin diffusion in lieu of chemical
+exchange to mediate polarization transfer between a magnetically dilute spin
+pool and this magnetically abundant spin reporter. As an initial test of this
+idea we target the spectroscopy of naturally-abundant 13C, and rely on a
+Fourier-encoded version of the CEST experiment for achieving broadbandness in
+coordination with both MAS and heteronuclear decoupling - features normally
+absent in CEST. Arbitrary evolutions of multiple 13C sites can thus be
+imprinted on the entire 1H reservoir, which is subsequently detected.
+Theoretical predictions suggest that orders-of-magnitude signal enhancements
+should be achievable in this manner - on the order of the ratio between the 13C
+and the 1H reservoirs' abundances. Experiments carried out under magic-angle
+spinning conditions evidenced ca. 5-10x enhancements. Further opportunities and
+challenges arising in this Fourier-Encoded Saturation Transfer (FEST) MAS NMR
+approach are briefly discussed.",2110.15451v1
+2001-11-01,The Nonlinear Turbulent Dynamo,"We simulate the evolution of an initially weak magnetic field in forced
+turbulence for a range of Prandtl numbers. The field grows exponentially with
+the Kulsrud-Anderson $k^{3/2}$ spectrum until the magnetic energy approaches
+the viscous-scale kinetic energy, where the magnetic forces then backreact on
+the velocity. Further growth proceeds more slowly until a saturated state is
+reached where the magnetic and kinetic energies are equal, and where the
+magnetic energy exists primarily at the resistive scale. We discuss the
+structure of this turbulence and the extrapolation of the results to
+astrophysically-large Prandtl numbers.",0111008v1
+2002-09-02,Pauli Paramagnetism of Neutron Star Matter and the Upper Limit for Neutron Star Magnetic Fields,"A relativistic version of Pauli paramagnetism for $n-p-e$ system inside a
+strongly magnetized neutron star has been developed. An analytical expressions
+for the saturation value of magnetic field strength for each of these
+constituents at which they are completely polarized have been obtained. From
+the fully polarized configuration of electronic component, an upper limit for
+neutron star magnetic field is predicted. It has been concluded that indeed,
+magnetars, as stronly magnetized young neutron stars can not exist if the
+constituents are electron, proton and neutron in $\beta$-equilibrium. An
+alternative model has been proposed.",0209015v1
+1999-08-17,Fluctuation-driven insulator-to-metal transition in an external magnetic field,"We consider a model for a metal-insulator transition of correlated electrons
+in an external magnetic field. We find a broad region in interaction and
+magnetic field where metallic and insulating (fully magnetized) solutions
+coexist and the system undergoes a first-order metal-insulator transition. A
+global instability of the magnetically saturated solution precedes the local
+ones and is caused by collective fluctuations due to poles in electron-hole
+vertex functions.",9908241v1
+2000-02-08,Magnetic properties of frustrated spin ladder,"The magnetic properties of the antiferromagnetic spin ladder with the
+next-nearest neighbor interaction, particularly under external field, are
+investigated by the exact diagonalization of the finite clusters and size
+scaling techniques. It is found that there exist two phases, the rung-dimer and
+rung-triplet phases, not only in the nonmagnetic ground state but also
+magnetized one, where the phase boundary has a small magnetization dependence.
+Only in the former phase, the magnetization curve is revealed to have a
+possible plateau at half the saturation moment, with a sufficient frustration.",0002113v1
+2001-05-07,Magnetoresistance of single-domain ferromagnetic particles,"We have performed magnetoresistance measurements on single-domain, submicron
+elliptical Ni particles using nonmagnetic probes in a four probe geometry at
+liquid helium temperatures. In the smallest particles, the magnetoresistance
+shows sharp jumps which are associated with the switching of individual
+domains. Using an anisotropic magnetoresistance model, we can reconstruct
+hysteresis loops of the normalized magnetization. The remanent magnetization in
+zero applied magnetic field is typically 15 percent less than the saturation
+magnetization. This relaxation of the magnetization may be due to surface
+effects or crystal grain structure in the particles.",0105144v1
+2001-08-31,Magnetization Plateau in the S=1 Spin Ladder with Competing Interactions,"Very recently a non-trivial magnetization plateau at 1/4 of the saturation
+magnetization was observed in the S=1 spin ladder BIP-TENO. In our previous
+work we proposed a possible mechanism of the plateau based on the second- and
+third-neighbor exchange couplings which lead to frustration. In order to
+confirm the realization of the mechanism, we compare the temperature dependence
+of the magnetic susceptibility and some critical magnetic fields obtained by
+the numerical calculation for the proposed model with the experimental results.",0108527v1
+2003-04-07,Magnetic excitations in the quantum spin system NH4CuCl3,"NH4CuCl3 has two magnetization plateaus at one-quarter and three-quarters of
+the saturation magnetization, irrespective of the external field direction.
+Magnetic excitations in NH4CuCl3 have been investigated by means of neutron
+inelastic scattering experiments. The constant-Q energy scan profiles were
+collected in a*-c* plane. Two well-defined magnetic excitations were observed.
+The dispersion relations along four different directions were determined. Both
+excitations are found weakly dispersive. The results were compared with those
+obtained from the ESR measurements.",0304172v1
+2003-04-24,Microscopic model for the magnetization plateaus in NH4CuCl3,"A simple model consisting of three distinct dimer sublattices is proposed to
+describe the magnetism of NH4CuCl3. It explains the occurrence of magnetization
+plateaus only at 1/4 and 3/4 of the saturation magnetization. The field
+dependence of the excitation modes observed by ESR measurements is also
+explained by the model. The model predicts that the magnetization plateaus
+should disappear under high pressure.",0304547v2
+2004-02-23,Dynamo mechanism: Effects of correlations and viscosities,"We analyze the effects of the background velocity and the initial magnetic
+field correlations, and viscosities on the turbulent dynamo and the
+\alpha-effect. We calculate the \alpha-coefficients for arbitrary magnetic and
+fluid viscosities, background velocity and the initial magnetic field
+correlations. We explicitly demonstrate that the general features of the
+initial growth and late-time saturation of the magnetic fields due to the
+non-linear feedback are qualitatively independent of these correlations. We
+also examine the hydrodynamic limit of the magnetic field growth in a
+renormalization group framework and discuss the possibilities of suppression of
+the dynamo growth below a critical rotation. We demonstrate that for
+Kolmogorov- (K41) type of spectra the Ekman number M >1/2 for dynamo growth to
+occur.",0402567v1
+2004-05-22,"Oxygen stoichiometry, crystal structure, and magnetism in La$_{0.5}$Sr$_{0.5}$CoO$_{3-δ}$","We have prepared a series of polycrystalline samples
+La$_{0.5}$Sr$_{0.5}$CoO$_{3-\delta}$} with $0 < \delta \le 0.21$ and
+characterized their oxygen content, crystal structure, and magnetic properties.
+While the fully oxygenated samples are good ferromagnets, samples with larger
+$\delta$ values display increasingly broad magnetic transitions. The saturation
+magnetization at 5 K falls rapidly as $\delta$ increases. First principles
+electronic structure calculations provide insights into the magnetic behavior
+of the fully oxygenated compound, and the manner in which ferromagnetic
+ordering is affected by increasing oxygen non-stoichiometry.",0405535v2
+2005-11-03,Step-like magnetization in a spin-chain system: Ca3Co2O6,"Due to a ferromagnetic in-chain coupling between Co$^{3+}$ ions at trigonal
+sites, chains Co$_2$O$_6$ are considered as large rigid spin moments. The
+antiferromagnetic Ising model on the triangular lattice is applied to describe
+an interchain ordering. An evolution of metastable states in a sweeping
+magnetic field is investigated by the single-flip technique. At the first
+approximation two steps in the magnetization curve and a plateau at 1/3 of the
+saturation magnetization are found. Four steps in magnetization are determined
+in high-order approximations in agreement with experimental results.",0511087v1
+2006-10-09,The Icosahedral Symmetry Antiferromagnetic Heisenberg Model,"The antiferromagnetic Heisenberg model on icosahedral symmetry $I_{h}$
+fullerene clusters exhibits unconventional magnetic properties, despite the
+lack of anisotropic interactions. At the classical level, and for number of
+sites $n \leq 720$, the magnetization has two discontinuities in an external
+magnetic field, except from the dodecahedron where it has three, emphasizing
+the role of frustration introduced by the pentagons in the unusual magnetic
+properties. For spin magnitudes $s_{i}={1/2}$ there is a discontinuity of
+quantum character close to saturation for $n \leq 80$. This common magnetic
+behavior indicates that it is a generic feature of $I_{h}$ fullerene clusters,
+irrespectively of $n$.",0610218v1
+2007-11-21,Anomalous Hall effect in a two dimensional electron gas with magnetic impurities,"Magnetic impurities play an important role in many spintronics-related
+materials. Motivated by this fact, we study the anomalous Hall effect in the
+presence of magnetic impurities, focusing on two-dimensional electron systems
+with Rashba spin-orbit coupling. We find a highly nonlinear dependence on the
+impurity polarization, including possible sign changes. At small impurity
+magnetizations, this is a consequence of the remarkable result that the linear
+term is independent of the spin-orbit coupling strength. Near saturation of the
+impurity spins, the anomalous Hall conductivity can be resonantly enhanced, due
+to interference between potential and magnetic scattering.",0711.3415v1
+2008-06-24,Reduction of velocity fluctuations in a turbulent flow of gallium by an external magnetic field,"The magnetic field of planets or stars is generated by the motion of a
+conducting fluid through a dynamo instability. The saturation of the magnetic
+field occurs through the reaction of the Lorentz force on the flow. In relation
+to this phenomenon, we study the effect of a magnetic field on a turbulent flow
+of liquid Gallium. The measurement of electric potential differences provides a
+signal related to the local velocity fluctuations. We observe a reduction of
+velocity fluctuations at all frequencies in the spectrum when the magnetic
+field is increased.",0806.3872v1
+2008-08-28,Inhomogeneous ferrimagnetic-like behavior in Gd2/3Ca1/3MnO3 single crystals,"We present a study of the magnetic properties of Gd2/3Ca1/3MnO3 single
+crystals at low temperatures. We show that this material behave as an
+inhomogeneous ferrimagnet. In addition to small saturation magnetization at 5
+K, we have found history dependent effects in the magnetization and the
+presence of exchange bias. These features are compatible with microscopic phase
+separation in the clean Gd2/3Ca1/3MnO3 system studied.",0808.3922v1
+2009-04-20,Magnetization of the Shastry-Sutherland antiferromagnet near the Ising limit,"Motivated by recent experiments on TmB4 (arXiv:0712.1537), we examine the
+phase diagram of the Shastry-Sutherland antiferromagnet in an applied magnetic
+field in the limit of strong Ising anisotropy. In classical Ising limit, we
+demonstrate that the only fractional magnetization plateau is at 1/3 of the
+saturated magnetization. We study the perturbative influence of transverse
+quantum spin fluctuations, and present evidence that they can stabilize a
+narrow 1/2 magnetization plateau.",0904.3018v1
+2009-10-19,Magnetic bubbles in FePd thin films near saturation,"The structure of domain walls delimiting magnetic bubbles in L10 FePd thin
+layers is described on the basis of Lorentz transmission electron microscopy
+(LTEM) and multiscale magnetic simulations. Images obtained by high resolution
+LTEM show the existence of magnetization reversal areas inside domain walls,
+called vertical Bloch lines (VBLs). Combining these observations and multiscale
+simulations on various geometries, we can identify the structure of these VBLs,
+notably the presence or not of magnetic singularities.",0910.3551v1
+2011-05-20,Quantum Magnetization Plateau in Spin-1 Triangular-Lattice Antiferromagnet Ba$_3$NiSb$_2$O$_9$,"We report the results of magnetization and specific heat measurements on
+Ba$_3$NiSb$_2$O$_9$, which is a quasi-two-dimensional spin-1 triangular-lattice
+antiferromagnet. We observed a nonclassical magnetization plateau at one-third
+of the saturation magnetization that is driven by spin frustration and quantum
+fluctuation. Exact diagonalization for a 21-site rhombic cluster was performed
+to analyze the magnetization process. Experimental and calculated results agree
+well.",1105.4046v2
+2011-06-10,Stress controlled magnetic properties of Cobalt nanowires,"We investigate the magnetic properties of a composite comprising of
+ferromagnetic Cobalt nanowires embedded in nanoporous anodized alumina
+template. We observe unusual increase in, the saturation magnetization and the
+coercive field, of the nanowires below 100 K. We also report the appearance of
+an unusual exchange bias effect in nanowires below 100 K. We argue our results
+can be understood on the basis of a competition between different magnetic
+energy scales induced by significant stresses acting on the nanowires at low
+temperatures. The composite behaves as an effective medium in which the
+magnetic anisotropy of nanowires can be conveniently controlled via stress on
+the nanowires.",1106.1965v1
+2011-10-10,Low-Temperature Magnetization Relaxation in Magnetic Molecular Solids,"The low temperature relaxation of the magnetization in magnetic molecular
+solids such as Fe$_8$ is studied using Monte Carlo simulations. A set of rate
+equations is developed to understand the simulations, and the results are
+compared. The simulations show that the magnetization of an initially saturated
+samples deviates as a square-root in time at short times, as observed
+experimentally, and this law is derived from the rate equations analytically.",1110.1899v1
+2012-12-17,Quantum Anomalous Hall Effect in Kagome Ice,"An anomalous Hall insulator without magnetic long-range ordering is
+theoretically reported in the absence of the relativistic spin-orbit coupling.
+It is realized in itinerant electrons coupled with the Ising spins on a <111>
+kagome plane of pyrochlore spin ice in applied magnetic field. We find that the
+kagome-ice type local spin correlation in the magnetization plateau state opens
+a charge gap without magnetic ordering, which results in quantization of the
+Hall conductivity. By Monte Carlo simulation, we identify the anomalous Hall
+insulating region in the magnetic phase diagram, in addition to another
+anomalous Hall insulator in a fully-saturated state.",1212.3855v1
+2013-10-01,Magnetization plateaus in generalized Shastry-Sutherland models,"We study an anisotropic Heisenberg antiferromagnet with ferromagnetic
+transverse spin exchange using exact quantum Monte Carlo methods. Such a model
+is relevant to a class of rare earth tetraboride materials that display a range
+of magnetization plateaus under applied magnetic field. The layered arrangement
+of magnetic ions in these materials is topologically equivalent to the
+Shastry-Sutherland lattice. In this frustrated geometry, we study the interplay
+of next-nearest neighbor interactions in stabilizing a plateau at half the
+saturation magnetization (or 1/2 plateau). We also show hysteresis-like
+behavior at the onset of the 1/3 plateau.",1310.0135v1
+2014-03-05,Magnetized strange quark matter in a mass-density-dependent model,"We investigate the properties of strange quark matter in a strong magnetic
+field with quark confinement by the density dependence of quark mass
+considering the total baryon number conservation, charge neutrality and
+chemical equilibrium. The strength of the magnetic field considered in this
+article is $10^{16} \sim 10^{20}$ G. It is found that an additional term should
+appear in the pressure expression to maintain thermodynamic consistency. At
+fixed density, the energy density of magnetized strange quark matter varies
+with the magnetic field strength. The exists a minimum with increasing the
+field strength, depending on the density. It is about $6\times10^{19}$ Gauss at
+two times the normal nuclear saturation density.",1403.1143v1
+2014-03-14,Magnetic Phases and Specific Heat of Ultra-Thin Holmium Films,"We report model calculations of the magnetic phases of very thin Ho films in
+the temperature interval between 20K and 132K, and show that slab size, surface
+effects and magnetic field due to spin ordering may impact significantly the
+magnetic phase diagram. There is a relevant reduction of the external field
+strength required to saturate the magnetization and for ultra-thin films the
+helical state does not form. We explore the heat capacity and the
+susceptibility as auxiliary tools to discuss the nature of the phase
+transitions.",1403.3589v1
+2014-06-04,Magnetization plateaus of an exactly solvable spin-1 Ising-Heisenberg diamond chain,"The spin-1 Ising-Heisenberg diamond chain in a magnetic field is exactly
+solved by a rigorous treatment based on the transfer-matrix method. An exact
+ground-state phase diagram includes in total three unconventional quantum
+ground states with a quantum entanglement of the decorating spin-1 Heisenberg
+dimers apart from two ground states with a classical spin arrangement. It is
+evidenced that all three values of the magnetization allowed for the spin-1
+diamond chain without translationally broken symmetry by the
+Oshikawa-Yamanaka-Affleck criterion can become evident in an outstanding
+stepwise magnetization curve with three intermediate plateaus at zero,
+one-third, and two-thirds of the saturation magnetization.",1406.0999v1
+2014-06-10,Spontaneous chiral symmetry breaking on a fully polarized frustrated magnet at finite temperature,"Frustration can introduce more-than-two minima in a spin dispersion relation
+even in a fully polarized magnet under high magnetic field. We generally
+discuss, on the fully polarized phase, the possibility of the chiral symmetry
+breaking where the number of magnons pumped by finite temperature deviates to
+one side of minima. We study this phase by constructing the Ginzburg-Landau
+energy which is controlled by the external magnetic field and interactions
+between magnons near the dispersion minima. This chirality breaking phase
+accompanies, not a magnetization perpendicular to the external field, but the
+vector chirality $S_m \times S_n$. We also discuss the possibility of the
+chirality breaking phase on LiCuVO4 slightly above the saturation field.",1406.2617v1
+2015-05-20,Dipolar spin-misalignment correlations in inhomogeneous magnets: comparison between neutron scattering and micromagnetic approaches,"In inhomogeneous bulk ferromagnets, the dominating sources of spin disorder
+are related to spatial variations of (i) the magnitude of the local saturation
+magnetization and of (ii) the magnitude and/or direction of the magnetic
+anisotropy field. For the particular example of a porous ferromagnet, where the
+magnetization inhomogeneity is at maximum, we demonstrate, by means of
+experimental neutron scattering data and micromagnetic simulations, the
+anisotropic character of magnetization fluctuations induced by the dipolar
+interaction.",1505.05337v1
+2016-02-26,Microscopic mechanism of the giant magnetocaloric effect in MnCoGe alloys probed by XMCD,"One important aspect of the magneto-structural transition in MnCoGe and
+related materials is the reduction in saturation magnetization from the
+orthorhombic to the hexagonal phase. Here, by combining an element specific
+magnetization probe such as x-ray magnetic circular dichroism and band
+structure calculations, we show that the magnetic moment instability between
+orthorhombic and hexagonal structures originates from a reduction in the Mn
+sub-lattice magnetization. The consequences of the moment instability for the
+magnetocaloric effect are discussed.",1602.08263v1
+2017-04-05,Magnetization process in a frustrated plaquette dimerized ladder,"The magnetic phase diagram of a plaquette dimerized antiferromagnetic system
+is studied by using a combination of numerical and analytical techniques. For
+the strongly frustrated regime, series expansions and bond operators techniques
+are employed to analyze zero magnetization plateau, whereas low energy
+effective models are used to study the complete magnetization process. The
+interplay between frustration and dimerization gives rise to a rich plateaus
+structure that is captured by effective models and corroborated by numerical
+density matrix renormalization group simulations, in particular the emergence
+of intermediate plateaus at M = 1/4 and 3/4 of saturation in the magnetization
+curve.",1704.01588v1
+2017-08-24,Magnetization Process of the Spin-1/2 Triangular-Lattice Heisenberg Antiferromagnet with Next-Nearest-Neighbor Interactions -- Plateau or Nonplateau,"An $S=1/2$ triangular-lattice Heisenberg antiferromagnet with
+next-nearest-neighbor interactions is investigated under a magnetic field by
+the numerical-diagonalization method. It is known that, in both cases of weak
+and strong next-nearest-neighbor interactions, this system reveals a
+magnetization plateau at one-third of the saturated magnetization. We examine
+the stability of this magnetization plateau when the amplitude of
+next-nearest-neighbor interactions is varied. We find that a nonplateau region
+appears between the plateau phases in the cases of weak and strong
+next-nearest-neighbor interactions.",1708.07248v1
+2019-02-01,Accurate Taylor transfer maps for large aperture iron dominated magnets used in charged particle separators and spectrometers,"For high-resolution separators like the projected Super-FRS at FAIR, an
+adapted and accurate ion-optical model considering realistic B-dependent magnet
+parameters is crucial in achieving the desired parameters (e.g. resolution) and
+to enable a fast optimization. Starting from the magnetic field measurements
+and simulations, rigidity-dependent Taylor transfer maps are generated for the
+Super-FRS preseparator dipole magnets. The effects of the magnetic saturation
+in the steel yoke on the image aberrations are analyzed.",1902.00464v1
+2020-01-31,Electric field control of interfacial Dzyaloshinskii-Moriya interaction in Pt/Co/AlO$_x$ thin films,"We studied electric field modification of magnetic properties in a
+Pt/Co/AlO$_x$ trilayer via magneto-optical Kerr microscopy. We observed the
+spontaneous formation of labyrinthine magnetic domain structure due to
+thermally activated domain nucleation and propagation under zero applied
+magnetic field. A variation of the period of the labyrinthine structure under
+electric field is observed as well as saturation magnetization and magnetic
+anisotropy variations. Using an analytical formula of the stripe equilibrium
+width we estimate the variation of the interfacial Dzyaloshinskii-Moriya
+interaction under electric field as function of the exchange stiffness
+constant.",2001.11982v1
+2020-12-13,Tunneling magnetoresistance in ensembles of ferromagnetic granules with exchange interaction and random easy axes of magnetic anisotropy,"We study the tunneling magnetoresistance in the ensembles of ferromagnetic
+granules with random easy axes of magnetic anisotropy taking into account the
+exchange interaction between granules. It is shown that due to the exchange
+interaction magnetoresistance is effectively decoupled from magnetization, i.e.
+the strongest negative magnetoresistance can be observed at the field where
+magnetization is almost saturated. Under some conditions, the sign of
+magnetoresistance can be reversed and tunneling magnetoresistance can become
+positive at certain magnetic fields. Our theory agrees with measurements of
+magnetoresistance in ensembles of Fe granules in SiCxNy matrix.",2012.07114v1
+2009-04-18,Quantum transport through a graphene nanoribbon-superconductor junction,"We study the electron transport through a graphene nanoribbon-superconductor
+junction. Both zigzag and armchair edge graphene nanoribbons are considered,
+and the effects of the magnetic field and disorder on the transport property
+are investigated. By using the tight-binding model and the non-equilibrium
+Green's function method, the expressions of the current, conductance, normal
+tunneling coefficient, and Andreev reflection coefficient are obtained. For a
+clean system and at zero magnetic field, the linear conductance increases
+approximatively in a linear fashion with the on-site energy. In the presence of
+a magnetic field and a moderate disorder, the linear conductance exhibits
+plateau structures for both armchair and zigzag edges. The plateau values
+increase with the width of the graphene ribbon. With a wide sample width, a
+saturated plateau value of $|\nu|e^2/h$ emerges at the filling factor $\nu$.
+For a small filling factor, the conductance can reach the saturated value at a
+small width, but for a high filling factor, it requires to have a quite wide
+sample width to reach the saturated value. In particular, the Andreev
+reflection coefficient is always at 0.5 after reaching the saturated value,
+independent of any system parameters. In addition, we also consider the finite
+bias case, in which the Andreev reflection coefficient and normal tunneling
+coefficient are studied.",0904.2838v1
+2018-05-22,Non-saturating large magnetoresistance in semimetals,"The rapidly expanding class of quantum materials known as {\emph{topological
+semimetals}} (TSM) display unique transport properties, including a striking
+dependence of resistivity on applied magnetic field, that are of great interest
+for both scientific and technological reasons. However, experimental signatures
+that can identify or discern the dominant mechanism and connect to available
+theories are scarce. Here we present the magnetic susceptibility ($\chi$), the
+tangent of the Hall angle ($\tan\theta_H$) along with magnetoresistance in four
+different non-magnetic semimetals with high mobilities, NbP, TaP, NbSb$_2$ and
+TaSb$_2$, all of which exhibit non-saturating large MR. We find that the
+distinctly different temperature dependences, $\chi(T)$ and the values of
+$\tan\theta_H$ in phosphides and antimonates serve as empirical criteria to
+sort the MR from different origins: NbP and TaP being uncompensated semimetals
+with linear dispersion, in which the non-saturating magnetoresistance arises
+due to guiding center motion, while NbSb$_2$ and TaSb$_2$ being {\it
+compensated} semimetals, with a magnetoresistance emerging from nearly perfect
+charge compensation of two quadratic bands. Our results illustrate how a
+combination of magnetotransport and susceptibility measurements may be used to
+categorize the increasingly ubiquitous non-saturating large magnetoresistance
+in TSMs.",1805.08797v2
+2021-11-08,Saturation of the asymmetric current filamentation instability under conditions relevant to relativistic shock precursors,"The current filamentation instability, which generically arises in the
+counterstreaming of supersonic plasma flows, is known for its ability to
+convert the free energy associated with anisotropic momentum distributions into
+kinetic-scale magnetic fields. The saturation of this instability has been
+extensively studied in symmetric configurations where the interpenetrating
+plasmas share the same properties (velocity, density, temperature). In many
+physical settings, however, the most common configuration is that of asymmetric
+plasma flows. For instance, the precursor of relativistic collisionless shock
+waves involves a hot, dilute beam of accelerated particles reflected at the
+shock front and a cold, dense inflowing background plasma. To determine the
+appropriate criterion for saturation in this case, we have performed
+large-scale 2D particle-in-cell simulations of counterstreaming
+electron-positron pair and electron-ion plasmas. We show that, in
+interpenetrating pair plasmas, the relevant criterion is that of magnetic
+trapping as applied to the component (beam or plasma) that carries the larger
+inertia of the two; namely, the instability growth suddenly slows down once the
+quiver frequency of those particles equals or exceeds the instability growth
+rate. We present theoretical approximations for the saturation level. These
+findings remain valid for electron-ion plasmas provided that electrons and ions
+are close to equipartition in the plasma flow of larger inertia. Our results
+can be directly applied to the physics of relativistic, weakly magnetized shock
+waves, but they can also be generalized to other cases of study.",2111.04651v1
+2016-10-10,Spintronics via non-axisymmetric chiral skyrmions,"Micromagnetic calculations demonstrate a peculiar evolution of
+non-axisymmetric skyrmions driven by an applied magnetic field in confined
+helimagnets with longitudinal modulations. We argue that these specific
+solitonic states can be employed in nanoelectronic devices as an effective
+alternative to the common axisymmetric skyrmions which occur in magnetically
+saturated states.",1610.02817v1
+2022-03-22,High-field magnetoresistance of microcrystalline and nanocrystalline Ni metal at 3 K and 300 K,"The magnetoresistance (MR) and the magnetization isotherms were studied up to
+high magnetic fields at T = 3 K and 300 K for a microcrystalline ($\mu$c) Ni
+foil corresponding to bulk Ni and for a nanocrystalline (nc) Ni foil. At T = 3
+K, for the $\mu$c-Ni sample with a residual resistivity ratio (RRR) of 331, the
+field dependence of the resistivity was similar to what was reported previously
+for high-purity ferromagnets whereas the MR(H) behavior for the nc-Ni sample
+with RRR = 9 resembled that what was observed at low temperatures for Ni-based
+alloys with low impurity concentration. In the magnetically saturated state,
+the resistivity increased with magnetic field for both samples at T = 3 K and
+the field dependence was dominated by the ordinary MR due to the Lorentz force
+acting on the electron trajectories. However, the MR(H) curves were found to be
+saturating for $\mu$c-Ni and non-saturating for nc-Ni, the difference arising
+from their very different electron mean free paths. At T = 300 K, the MR(H)
+curves of both Ni samples were very similar to those known for bulk Ni. After
+magnetic saturation, the resistivity decreased nearly linearly with magnetic
+field which behavior is due to the suppression of thermally-induced magnetic
+disorder with increasing magnetic field. The MR(H) data were analyzed at both
+temperatures with the help of Kohler plots from which the resistivity
+anisotropy splitting ($\Delta\rho_{AMR}$) and the anisotropic magnetoresistance
+(AMR) ratio were derived. It was demonstrated that at T = 300 K,
+$\rho(H\rightarrow 0)=\rho(B\rightarrow 0)$ due to the negligible contribution
+of the ordinary MR. The data for the two Ni samples at 3 K and 300 K were found
+to indicate an approximately linear scaling of $\Delta\rho_{AMR}$ with the
+zero-field resistivity. This implies that the AMR ratio does not vary
+significantly with temperature in either microstructural state of Ni.",2203.11568v1
+2006-04-07,New mechanism of generation of large-scale magnetic fields in merging protogalactic and protostellar clouds,"A new mechanism of generation of large-scale magnetic fields in colliding
+protogalactic clouds and merging protostellar clouds is discussed. Interaction
+of the colliding clouds produces large-scale shear motions which are
+superimposed on small-scale turbulence. Generation of the large-scale magnetic
+field is due to a ''shear-current"" effect (or ""vorticity-current"" effect), and
+the mean vorticity is caused by the large-scale shear motions of colliding
+clouds. This effect causes the generation of the mean magnetic field even in a
+nonrotating and nonhelical homogeneous turbulence. There is no quenching of the
+nonlinear shear-current effect contrary to the quenching of the nonlinear alpha
+effect, the nonlinear turbulent magnetic diffusion, etc. During the nonlinear
+growth of the mean magnetic field, the shear-current effect only changes its
+sign at some value of the mean magnetic field which determines the level of the
+saturated mean magnetic field. Numerical study shows that the saturated level
+of the mean magnetic field is of the order of the equipartition field
+determined by the turbulent kinetic energy. The estimated large-scale magnetic
+field for merging protogalactic clouds is about several microgauss, and for
+merging protostellar clouds is of the order of several tenth of microgauss.",0604170v1
+1998-06-09,Magnetization Properties of Some Quantum Spin Ladders,"The experimental realization of various spin ladder systems has prompted
+their detailed theoretical investigations. Here we study the evolution of
+ground state magnetization with an external magnetic field for two different
+antiferromagnetic systems: a three-legged spin-1/2 ladder, and a two-legged
+spin-1/2 ladder with an additional diagonal interaction. The finite system
+density-matrix renormalization group method is employed for numerical studies
+of the three-chain system, and an effective low-energy Hamiltonian is used in
+the limit of strong interchain coupling to study the two- and three-chain
+systems. The three-chain system has a magnetization plateau at one-third of the
+saturation magnetization. The two-chain system has a plateau at zero
+magnetization due to a gap above the singlet ground state. It also has a
+plateau at half of the saturation magnetization for a certain range of values
+of the couplings. We study the regions of transitions between plateaus
+numerically and analytically, and find that they are described, at first order
+in a strong-coupling expansion, by an XXZ spin-1/2 chain in a magnetic field;
+the second order terms give corrections to the XXZ model. We also study
+numerically some low-temperature properties of the three-chain system, such as
+the magnetization, magnetic susceptibility and specific heat.",9806111v2
+2012-01-04,Simulations of a Magnetic Fluctuation Driven Large Scale Dynamo and Comparison with a Two-scale Model,"Models of large scale (magnetohydrodynamic) dynamos (LSD) which couple large
+scale field growth to total magnetic helicity evolution best predict the
+saturation of LSDs seen in simulations. For the simplest so called ""{\alpha}2""
+LSDs in periodic boxes, the electromotive force driving LSD growth depends on
+the difference between the time-integrated kinetic and current helicity
+associated with fluctuations. When the system is helically kinetically forced
+(KF), the growth of the large scale helical field is accompanied by growth of
+small scale magnetic (and current) helicity which ultimately quench the LSD.
+Here, using both simulations and theory, we study the complementary
+magnetically forced(MF) case in which the system is forced with an electric
+field that supplies magnetic helicity. For this MF case, the kinetic helicity
+becomes the back-reactor that saturates the LSD. Simulations of both MF and KF
+cases can be approximately modeled with the same equations of magnetic helicity
+evolution, but with complementary initial conditions. A key difference between
+KF and MF cases is that the helical large scale field in the MF case grows with
+the same sign of injected magnetic helicity, whereas the large and small scale
+magnetic helicities grow with opposite sign for the KF case. The MF case can
+arise even when the thermal pressure is approximately smaller than the magnetic
+pressure, and requires only that helical small scale magnetic fluctuations
+dominate helical velocity fluctuations in LSD driving. We suggest that LSDs in
+accretion discs and Babcock models of the solar dynamo are actually MF LSDs.",1201.0800v2
+2013-09-27,Phonons correlation with magnetic excitations in weak ferromagnet YCrO3,"We report on the temperature dependent Raman spectroscopic studies of
+orthorombic distorted perovskite YCrO3 in the temperature range of 20-300K.
+Temperature dependence of DC-magnetization measurement under field cooled and
+zero field cooled modes confirmed the transition temperature (TN ~142K) and
+anomalous characteristic temperature (T* ~60K), above which magnetization tends
+to saturate. Magnetization isotherm recorded below TN at 125K shows clear loop
+opening without magnetization saturation up to 20kOe, indicating the
+coexistence of antiferromagnetic (AFM) interaction with weak ferromagnetic
+(WFM) phase. Mean field calculation for exchange constants further confirms the
+complex magnetic phase below TN. Temperature evolution of lineshape parameters
+of selected modes (associated with the octahedral rotation and A-shift in the
+unit cell) revealed anomalous phonon shift near Cr3+ magnetic ordering
+temperature (TN ~142K). Additional phonon anomaly was identified at T* ~60K in
+agreement with the magnetization results and reflects the change in spin
+dynamics, plausibly due to the change in Cr-spin configuration. Moreover, the
+positive and negative shift in Raman frequency below TN revel the existence of
+competing WFM and AFM exchanges. The phonon shift of B3g (3)-octahedral
+rotation mode fairly scaled with the square of sublattice magnetization from TN
+to T*, below which it start to depart from theconventional behaviour and need
+further attention. This correlation between magnetic and Raman data elucidate
+the spin-phonon coupling owing to the multiferroic phenomenon in YCrO3.",1309.7254v1
+2021-07-27,Dynamo instabilities in plasmas with inhomogeneous chiral chemical potential,"We study the dynamics of magnetic fields in chiral magnetohydrodynamics,
+which takes into account the effects of an additional electric current related
+to the chiral magnetic effect in high energy plasmas. We perform direct
+numerical simulations, considering weak seed magnetic fields and
+inhomogeneities of the chiral chemical potential mu_5 with a zero mean. We
+demonstrate that a small-scale chiral dynamo can occur in such plasmas if
+fluctuations of mu_5 are correlated on length scales that are much larger than
+the scale on which the dynamo growth rate reaches its maximum. Magnetic
+fluctuations grow by many orders of magnitude due to the small-scale chiral
+dynamo instability. Once the nonlinear backreaction of the generated magnetic
+field on fluctuations of mu_5 sets in, the ratio of these scales decreases and
+the dynamo saturates. When magnetic fluctuations grow sufficiently to drive
+turbulence via the Lorentz force before reaching maximum field strength, an
+additional mean-field dynamo phase is identified. The mean magnetic field grows
+on a scale that is larger than the integral scale of turbulence after the
+amplification of the fluctuating component saturates. The growth rate of the
+mean magnetic field is caused by a magnetic alpha effect that is proportional
+to the current helicity. With the onset of turbulence, the power spectrum of
+mu_5 develops a universal k^(-1) scaling independently of its initial shape,
+while the magnetic energy spectrum approaches a k^(-3) scaling.",2107.13028v3
+2013-10-02,Magnetic Field Amplification in Young Galaxies,"The Universe at present is highly magnetized, with fields of the order of a
+few 10^-5 G and coherence lengths larger than 10 kpc in typical galaxies like
+the Milky Way. We propose that the magnetic field was amplified to this values
+already during the formation and the early evolution of the galaxies.
+Turbulence in young galaxies is driven by accretion as well as by supernova
+(SN) explosions of the first generation of stars. The small-scale dynamo can
+convert the turbulent kinetic energy into magnetic energy and amplify very weak
+primordial magnetic seed fields on short timescales. The amplification takes
+place in two phases: in the kinematic phase the magnetic field grows
+exponentially, with the largest growth on the smallest non-resistive scale. In
+the following non-linear phase the magnetic energy is shifted towards larger
+scales until the dynamo saturates on the turbulent forcing scale. To describe
+the amplification of the magnetic field quantitatively we model the
+microphysics in the interstellar medium (ISM) of young galaxies and determine
+the growth rate of the small-scale dynamo. We estimate the resulting saturation
+field strengths and dynamo timescales for two turbulent forcing mechanisms:
+accretion-driven turbulence and SN-driven turbulence. We compare them to the
+field strength that is reached, when only stellar magnetic fields are
+distributed by SN explosions. We find that the small-scale dynamo is much more
+efficient in magnetizing the ISM of young galaxies. In the case of
+accretion-driven turbulence a magnetic field strength of the order of 10^-6 G
+is reached after a time of 24-270 Myr, while in SN-driven turbulence the dynamo
+saturates at field strengths of typically 10^-5 G after only 4-15 Myr. This is
+considerably shorter than the Hubble time. Our work can help to understand why
+present-day galaxies are highly magnetized.",1310.0853v2
+2023-11-30,Anomalous Hall effect with plateaus observed in a magnetic Weyl semimetal NdAlGe at low temperatures,"In the $R$Al(Si,Ge) ($R$: lanthanides) family, both spatial inversion and
+time-reversal symmetries are broken. This may offer opportunities to study
+Weyl-fermion physics in nontrivial spin structures emerging from a
+noncentrosymmetric crystal structure. In this study, we investigated the
+anomalous Hall effect (AHE) in NdAlGe via magnetotransport, magnetization, and
+magnetic torque measurements down to 40 mK (0.4 K for magnetization). The
+single crystals grown by a laser-heated floating-zone method exhibit a single
+magnetic phase transition at $T_{\rm M}$ = 13.5 K, where the $T_{\rm M}$ is the
+transition temperature. With the magnetic field parallel to the easy
+$\lbrack$001$\rbrack$ axis, the AHE gradually evolves as the temperature
+decreases below $T_{\rm M}$. The anomalous Hall conductivity (AHC) reaches
+$\sim$320 $\Omega^{-1}$cm$^{-1}$ at 40 mK in the magnetically saturated state.
+Except in low-temperature low-field plateau phases, the AHC and magnetization
+are proportional, and their ratio agrees with the ratios for conventional
+ferromagnets, suggesting that the intrinsic AHE occurs by the Karplus-Luttinger
+mechanism. Below $\sim$0.6 K, the curves of Hall resistivity against the field
+exhibit plateaus at low fields below $\sim$0.5 T, correlating with the plateaus
+in the magnetization curve. For the first plateau, the magnetization is one
+order of magnitude smaller than the magnetically saturated state, whereas the
+AHE is more than half that in the saturated state. This finding under well
+below $T_{\rm M}$ suggests that the AHE at the first plateau is not governed by
+the magnetization and may be interpreted based on a multipole or spin
+chirality.",2312.00222v2
+2002-05-21,Field-Induced Magnetic Ordering in the Quantum Spin System KCuCl$_3$,"KCuCl$_3$ is a three-dimensional coupled spin-dimer system and has a singlet
+ground state with an excitation gap ${\Delta}/k_{\rm B}=31$ K. High-field
+magnetization measurements for KCuCl$_3$ have been performed in static magnetic
+fields of up to 30 T and in pulsed magnetic fields of up to 60 T. The entire
+magnetization curve including the saturation region was obtained at $T=1.3$ K.
+  From the analysis of the magnetization curve, it was found that the exchange
+parameters determined from the dispersion relations of the magnetic excitations
+should be reduced, which suggests the importance of the renormalization effect
+in the magnetic excitations. The field-induced magnetic ordering accompanied by
+the cusplike minimum of the magnetization was observed as in the isomorphous
+compound TlCuCl$_3$. The phase boundary was almost independent of the field
+direction, and is represented by the power law. These results are consistent
+with the magnon Bose-Einstein condensation picture for field-induced magnetic
+ordering.",0205429v1
+2002-11-21,Temperature-dependent magnetization in diluted magnetic semiconductors,"We calculate magnetization in magnetically doped semiconductors assuming a
+local exchange model of carrier-mediated ferromagnetic mechanism and using a
+number of complementary theoretical approaches. In general, we find that the
+results of our mean-field calculations, particularly the dynamical mean field
+theory results, give excellent qualitative agreement with the experimentally
+observed magnetization in systems with itinerant charge carriers, such as
+Ga_{1-x}Mn_xAs with 0.03 < x < 0.07, whereas our percolation-theory-based
+calculations agree well with the existing data in strongly insulating
+materials, such as Ge_{1-x}Mn_x. We comment on the issue of non-mean-field like
+magnetization curves and on the observed incomplete saturation magnetization
+values in diluted magnetic semiconductors from our theoretical perspective. In
+agreement with experimental observations, we find the carrier density to be the
+crucial parameter determining the magnetization behavior. Our calculated
+dependence of magnetization on external magnetic field is also in excellent
+agreement with the existing experimental data.",0211496v1
+2004-03-09,Magnetization plateaux of S = 1/2 two-dimensional frustrated antiferromagnet Cs$_2$CuBr$_4$,"The field induced magnetic phase transitions of Cs$_2$CuBr$_4$ were
+investigated by means of magnetization process and neutron scattering
+experiments. This system undergoes magnetic phase transition at Ne\'{e}l
+temperature $T_\mathrm{N}=1.4$ K at zero field, and exhibits the magnetization
+plateau at approximately one third of the saturation magnetization for the
+field directions $H\parallel b$ and $H\parallel c$. In the present study,
+additional symptom of the two-third magnetization plateau was found in the
+field derivative of the magnetization process. The magnetic structure was found
+to be incommensurate with the ordering vector $\boldsymbol{Q}=(0, 0.575, 0)$ at
+zero field. With increasing magnetic field parallel to the c-axis, the ordering
+vector increases continuously and is locked at $\boldsymbol{Q}=(0, 0.662, 0)$
+in the plateau field range $13.1 \mathrm{T} < H < 14.4 \mathrm{T}$. This
+indicates that the collinear \textit{up-up-down} spin structure is stabilized
+by quantum fluctuation at the magnetization plateau.",0403234v1
+2008-09-09,Magnetic Properties of Ni-Fe Nanowire Arrays: Effect of Template Material and Deposition Conditions,"The objective of this work is to study the magnetic properties of arrays of
+Ni-Fe nanowires electrodeposited in different template materials such as porous
+silicon, polycarbonate and alumina. Magnetic properties were studied as a
+function of template material, applied magnetic field (parallel and
+perpendicular) during deposition, wire length, as well as magnetic field
+orientation during measurement. The results show that application of magnetic
+field during deposition strongly influences the c-axis preferred orientation
+growth of Ni-Fe nanowires. The samples with magnetic field perpendicular to
+template plane during deposition exhibits strong perpendicular anisotropy with
+greatly enhanced coercivity and squareness ratio, particularly in Ni-Fe
+nanowires deposited in polycarbonate templates. In case of polycarbonate
+template, as magnetic field during deposition increases, both coercivity and
+squareness ratio also increase. The wire length dependence was also measured
+for polycarbonate templates. As wire length increases, coercivity and
+squareness ratio decrease, but saturation field increases. Such magnetic
+behavior (dependence on template material, magnetic field, wire length) can be
+qualitatively explained by preferential growth phenomena, dipolar interactio",0809.1657v1
+2018-11-01,High-field Magnetism of the Honeycomb-lattice Antiferromagnet Cu$_2$(pymca)$_3$(ClO$_4$),"We report on the experimental results of magnetic susceptibility, specific
+heat, electron spin resonance (ESR), and high-field magnetization measurements
+on a polycrystalline sample of the spin-$1/2$ distorted honeycomb-lattice
+antiferromagnet Cu$_2$(pymca)$_3$(ClO$_4$). Magnetic susceptibility shows a
+broad peak at about 25~K, which is typical of a low dimensional
+antiferromagnet, and no long range magnetic order is observed down to 0.6~K in
+the specific heat measurements. Magnetization curve up to 70~T at 1.4~K shows
+triple stepwise jumps. Assuming three different exchange bonds $J_{\rm A}$,
+$J_{\rm B}$ and $J_{\rm C}$ from the structure, the calculated magnetization
+curve reproduces the observed one when $J_{\rm A}/k_{\rm B} = 43.7~{\rm K}$,
+$J_{\rm B}/J_{\rm A} = 1$ and $J_{\rm C}/J_{\rm A} = 0.2$ except the
+magnetization near 70~T, where the observed magnetization indicates another
+step while the calculated magnetization becomes saturated. The relationship
+between magnetization plateaus and exchange bonds is discussed based on the
+numerical calculations.",1811.00278v1
+2002-04-29,Dynamic nonlinearity in large scale dynamos with shear,"We supplement the mean field dynamo growth equation with the total magnetic
+helicity evolution equation. This provides an explicitly time dependent model
+for alpha quenching in dynamo theory. For dynamos without shear, this approach
+accounts for the observed large scale field growth and saturation in numerical
+simulations. After a significant kinematic phase, the dynamo is resistively
+quenched, i.e. the saturation time depends on the microscopic resistivity. This
+is independent of whether or not the turbulent diffusivity is resistively
+quenched. We find that the approach is also successful for dynamos that include
+shear and exhibit migratory waves (cycles). In this case however, whether or
+not the cycle period remains of the order of the dynamical time scale at large
+magnetic Reynolds numbers does depend how on how the turbulent magnetic
+diffusivity quenches. Since this is unconstrained by magnetic helicity
+conservation, the diffusivity is presently an input parameter. Comparison to
+current numerical experiments suggests a turbulent diffusivity that depends
+only weakly on the magnetic Reynolds number, but higher resolution simulations
+are needed.",0204497v2
+2004-12-02,Nonlinear behavior of a non-helical dynamo,"A three-dimensional numerical computation of magnetohydrodynamic dynamo
+behavior is described. The dynamo is mechanically forced with a driving term of
+the Taylor-Green type. The magnetic field development is followed from
+negligibly small levels to saturated values that occur at magnetic energies
+comparable to the kinetic energies. Though there is locally a helicity density,
+there is no overall integrated helicity in the system. Persistent oscillations
+are observed in the saturated state for not-too-large mechanical Reynolds
+numbers, oscillations in which the kinetic and magnetic energies vary out of
+phase but with no reversal of the magnetic field. The flow pattern exhibits
+considerable geometrical structure in this regime. As the Reynolds number is
+raised, the oscillations disappear and the energies become more nearly
+stationary, but retain some unsystematically fluctuating turbulent time
+dependence. The regular geometrical structure of the fields gives way to a more
+spatially disordered distribution. The injection and dissipation scales are
+identified and the different components of energy transfer in Fourier space are
+analyzed, in particular in the context of clarifying the role played by
+different flow scales in the amplification of the magnetic field.",0412071v1
+2004-01-31,Magnetic properties of amorphous Co$_x$Nb$_{100-x}$ alloys produced by mechanical alloying,"Three amorphous Co$_x$Nb$_{100-x}$ alloys, Co$_{25}$Nb$_{75}$,
+Co$_{57}$Nb$_{43}$ and Co$_{80}$Nb$_{20}$, were produced by Mechanical Alloying
+starting from the elemental powders. Their magnetic properties were determined
+using an alternating gradient force magnetometer (AGFM), and the remanent
+magnetizations, saturation fields and coercive fields were obtained from the
+hysteresis loop. The alloys have a relatively high saturation field, which
+decreases as the composition becomes richer in Co. The coercivity and remanent
+magnetization reach an optimal value around 57% at.Co, making {\em
+a}-Co$_{57}$Nb$_{43}$ the hardest magnetic material among the three alloys.
+Further addition of Co produces a soft alloy.",0402014v1
+2004-06-08,Magnetism and electron spin resonance in single crystalline beta-AgNpO2(SeO3),"We report magnetization, susceptibility, electrical transport, and electron
+spin resonance (ESR) studies of single crystals of beta-AgNpO2(SeO3). Here the
+valence of the Np sites is expected to be Np(V). We observe a magnetic
+transition below 8 K, where the transition temperature is dependent on the
+effective magnetic moment. Although the transition appears to be ferromagnetic,
+no hysteresis is seen in the magnetization, and the saturation moment above 0.1
+T is found to be about 60% of the free NpO2 ion moment. The decrease in the Np
+moments determined experimentally is thought to arise from crystal field and
+spin-orbit effects. Although Np(V) is expected to be ESR silent, we observe
+temperature dependent ESR spectra at ~44 GHz (for fields above the saturation
+field) that show slight shifts in the g-factor and line width at low
+temperatures. Our results provide evidence that both Np(V) and Np(IV) valences
+are present, where the latter may be a minority population. The crystals,
+although dark in appearance, are electrically insulating (rho > 10^10 Ohm-cm)
+at room temperature.",0406194v1
+2005-04-07,Observation of spin-wave characteristics in the two-dimensional ferromagnetic ordering of in-plane spins,"The role of dipolar interactions and anisotropy are important to obtain,
+otherwise forbidden, ferromagnetic ordering at finite temperature for ions
+arranged in two-dimensional (2D) arrays (monolayers). Here we demonstrate that
+conventional low temperature magnetometry and polarized neutron scattering
+measurements can be performed to study ferromagnetic ordering of in-plane spins
+in 2D systems using a multilayer stack of non-interacting monolayers of
+gadolinium ions. The spontaneous magnetization is absent in the heterogenous
+magnetic phase observed here and the saturation value of the net magnetization
+was found to depend on the applied magnetic field. The net magnetization rises
+exponentially with lowering temperature and then reaches saturation following a
+$T\ln(\beta T)$ dependence. These findings verify predictions of the spin-wave
+theory of 2D in-plane spin system with ferromagnetic interaction and will
+initiate further theoretical development.",0504155v1
+2008-01-17,Bose-Einstein condensation in antiferromagnets close to the saturation field,"At zero temperature and strong applied magnetic fields the ground sate of an
+anisotropic antiferromagnet is a saturated paramagnet with fully aligned spins.
+We study the quantum phase transition as the field is reduced below an upper
+critical $H_{c2}$ and the system enters a XY-antiferromagnetic phase. Using a
+bond operator representation we consider a model spin-1 Heisenberg
+antiferromagnetic with single-ion anisotropy in hyper-cubic lattices under
+strong magnetic fields. We show that the transition at $H_{c2}$ can be
+interpreted as a Bose-Einstein condensation (BEC) of magnons. The theoretical
+results are used to analyze our magnetization versus field data in the organic
+compound $NiCl_2$-$4SC(NH_2)_2$ (DTN) at very low temperatures. This is the
+ideal BEC system to study this transition since $H_{c2}$ is sufficiently low to
+be reached with static magnetic fields (as opposed to pulsed fields). The
+scaling of the magnetization as a function of field and temperature close to
+$H_{c2}$ shows excellent agreement with the theoretical predictions. It allows
+to obtain the quantum critical exponents and confirm the BEC nature of the
+transition at $H_{c2}$.",0801.2795v2
+2009-08-09,Synthetic antiferromagnet with Heusler alloy Co2FeAl ferromagnetic layers,"Heusler alloy Co2FeAl was employed as ferromagnetic layers in
+Co2FeAl/Ru/Co2FeAl synthetic antiferromagnet structures. The experimental
+results show that the structure with a Ru thickness of 0.45 nm takes on
+strongly antiferromagnetic coupling, which maintains up to 150 oC annealing for
+1 hour. The structure has a very low saturation magnetization Ms of 425 emu/cc,
+a low switching field Hsw of 4.3 Oe and a high saturation field Hs of 5257 Oe
+at room temperature, which are favorable for application in ultrahigh density
+magnetic read heads or other magnetic memory devices. XRD study testifies that
+the as-deposited Co2FeAl film is in B2 phase. Therefore Heusler alloys can be
+used to fabricate SyAF and it is possible to make ""all-Heusler"" spin-valves or
+magnetic tunneling junctions with better magnetic switching properties and high
+magnetoresistance.",0908.1215v1
+2012-04-24,Interstitial Transition Metal Doping in Hydrogen Saturated Silicon Nanowires,"We report a first principles systematic study of atomic, electronic, and
+magnetic properties of hydrogen saturated silicon nanowires (H-SiNW) which are
+doped by transition metal (TM) atoms placed at various interstitial sites. Our
+results obtained within the conventional GGA+U approach have been confirmed
+using an hybrid functional. In order to reveal the surface effects we examined
+three different possible facets of H-SiNW along [001] direction with a diameter
+of ~2nm. The energetics of doping and resulting electronic and magnetic
+properties are examined for all alternative configurations. We found that
+except Ti, the resulting systems have magnetic ground state with a varying
+magnetic moment. While H-SiNWs are initially non-magnetic semiconductor, they
+generally become ferromagnetic metal upon TM doping. Even they posses
+half-metallic behavior for specific cases. Our results suggest that H-SiNWs can
+be functionalized by TM impurities which would lead to new electronic and
+spintronic devices at nanoscale.",1204.5468v1
+2012-05-23,Two-step transition in a magnetoelectric ferrimagnet Cu2OSeO3,"We report a detailed single crystal investigation of a magnetoelectric
+ferrimagnet Cu2OSeO3 using dc magnetization and ac susceptibility along the
+three principal directions [100], [110] and [111]. We have observed that in
+small magnetic fields two magnetic transitions occur, one at Tc = 57 K and the
+second one at TN = 58 K. At Tc the non-linear susceptibility reveals the
+emergence of the ferromagnetic component and below Tc the magnetization
+measurements show the splitting between field-cooled and zero-field-cooled
+regimes. Above 1000 Oe the magnetization saturates and the system is in a
+single domain state. The temperature dependence of the saturation below Tc can
+be well described by m(T) = m(0)[1 - (T/Tc)^2]^{\beta}, with m(0) = 0.56
+(mu)B/Cu, corresponding to the 3-up-1-down configuration. The dielectric
+constant measured on a thin single crystal shows a systematic deviation below
+the transition, indicating an intrinsic magnetoelectric effect.",1205.5100v1
+2012-10-24,Coherent structures and the saturation of a nonlinear dynamo,"Eulerian and Lagrangian tools are used to detect coherent structures in the
+velocity and magnetic fields of a mean--field dynamo, produced by direct
+numerical simulations of the three--dimensional compressible
+magnetohydrodynamic equations with an isotropic helical forcing and moderate
+Reynolds number. Two distinct stages of the dynamo are studied, the kinematic
+stage, where a seed magnetic field undergoes exponential growth, and the
+saturated regime. It is shown that the Lagrangian analysis detects structures
+with greater detail, besides providing information on the chaotic mixing
+properties of the flow and the magnetic fields. The traditional way of
+detecting Lagrangian coherent structures using finite--time Lyapunov exponents
+is compared with a recently developed method called function M. The latter is
+shown to produce clearer pictures which readily permit the identification of
+hyperbolic regions in the magnetic field, where chaotic transport/dispersion of
+magnetic field lines is highly enhanced.",1210.6637v1
+2013-03-12,Global Simulations of Magnetorotational Instability in The Collapsed Core of A Massive Star,"We performed the first numerical simulations of magnetorotational instability
+from a sub-magnetar-class seed magnetic field in core collapse supernovae. As a
+result of axisymmetric ideal MHD simulations, we found that the magnetic field
+is greatly amplified to magnetar-class strength. In saturation phase, a
+substantial part of the core is dominated by turbulence, and the magnetic field
+possesses dominant large scale components, comparable to the size of the
+proto-neutron star. A pattern of coherent chanel flows, which generally appears
+during exponential growth phase in previous local simulations, is not observed
+in our global simulations. While the approximate convergence in the exponential
+growth rate is attained by increasing spatial resolution, that of the
+saturation magnetic field is not achieved due to still large numerical
+diffusion. Although the effect of magnetic field on the dynamics is found to be
+mild, a simulation with a high-enough resolution might result in a larger
+impact.",1303.2856v1
+2014-03-10,Effective anisotropy gradient in pressure graded [Co/Pd] multilayers,"A vertically graded anisotropy profile has been proposed as an optimized
+balance of low coercivity and thermal stability for multilayers used in
+magnetic media. Deposition pressure is known to have a profound effect on the
+magnetic reversal properties of Co/Pd multilayers, making it an attractive
+control parameter for achieving an anisotropy gradient. We have used polarized
+neutron reflectometry to study the depth-dependent reversal behavior of
+""pressure-graded"" Co/Pd, and observed pronounced gradients in the saturation
+magnetization and in the rate at which magnetization changes with field (the
+effective anisotropy). While the anisotropy gradient likely arises from a
+combination of factors intrinsic to deposition pressure, micromagnetic
+simulations indicate that the observed saturation magnetization gradient alone
+has a major effect on the resulting coercivity.",1403.2126v2
+2014-09-04,NaCuMoO_4(OH) as a Candidate Frustrated J_1-J_2 Chain Quantum Magnet,"In a frustrated J_1-J_2 chain with the nearest-neighbor ferromagnetic
+interaction J_1 and the next-nearest-neighbor antiferromagnetic interaction
+J_2, novel magnetic states such as a spin-nematic state are theoretically
+expected. However, they have been rarely examined in experiments because of the
+difficulty in obtaining suitable model compounds. We show here that the
+quasi-one-dimensional antiferromagnet NaCuMoO_4(OH), which comprises
+edge-sharing CuO_2 chains, is a good candidate J_1-J_2 chain antiferromagnet.
+The exchange interactions are estimated as J_1 = - 51 K and J_2 = 36 K by
+comparing the magnetic susceptibility, heat capacity, and magnetization data
+with the data obtained using calculations by the exact diagonalization method.
+High-field magnetization measurements at 1.3 K show a saturation above 26 T
+with little evidence of a spin nematic state expected just below the saturation
+field, which is probably due to smearing effects caused by thermal fluctuations
+and the polycrystalline nature of the sample.",1409.1310v1
+2015-07-17,First-order commensurate-incommensurate magnetic phase transition in the coupled FM spin-1/2 two-leg ladders,"We consider the spin-1/2 two-leg ladders with ferromagnetic (FM) interactions
+along legs and rungs. Using the stochastic series expansion QMC method, we
+study the low-temperature magnetic behavior of the system. An isolated spin-1/2
+FM two-leg ladder is in the gapped saturated FM phase at zero temperature. As
+soon as the spin-1/2 FM two-leg ladders are connected with antiferromagnetic
+(AFM) inter-ladder interaction, a first-order commensurate-incommensurate
+quantum phase transition occurs in the ground state magnetic phase diagram. In
+fact a jump in the magnetization curve is observed. We found that, coupled
+spin-1/2 FM two-leg ladders are in a nonmagnetic phase at zero temperature.
+Applying a magnetic field, the ground state of coupled spin-1/2 FM two-leg
+ladders remains in the nonmagnetic phase up to a quantum saturate critical
+field.",1507.04954v1
+2019-02-08,Magnetization beyond the Ising limit of Ho$_2$Ti$_2$O$_7$,"We report that the local Ising anisotropy in pyrochlore oxides - the crucial
+requirement for realizing the spin-ice state - can be broken by means of high
+magnetic fields. For the case of the well-established classical spin-ice
+compound Ho$_2$Ti$_2$O$_7$ the magnetization exceeds the angle-dependent
+saturation value of the Ising limit using ultra-high fields up to 120 T.
+However, even under such extreme magnetic fields full saturation cannot be
+achieved. Crystal-electric-field calculations reveal that a level crossing for
+two of the four ion positions leads to magnetization steps at 55 and 100 T. In
+addition, we show that by using a field sweep rate in the range of the
+spin-relaxation time the dynamics of the spin system can be probed. Exclusively
+at 25 ns/T a new peak of the susceptibility appears around 2 T. We argue, this
+signals the cross-over between spin-ice and polarized correlations.",1902.02990v1
+2020-10-16,Magnetoelastic study on the frustrated quasi-one-dimensional spin-1/2 magnet LiCuVO$_4$,"We investigated the magnetoelastic properties of the quasi-one-dimensional
+spin-1/2 frustrated magnet LiCuVO$_4$. Longitudinal-magnetostriction
+experiments were performed at 1.5 K in high magnetic fields of up to 60 T
+applied along the $b$ axis, i.e., the spin-chain direction. The
+magnetostriction data qualitatively resemble the magnetization results, and
+saturate at $H_{\text{sat}} \approx 54$ T, with a relative change in sample
+length of $\Delta L/L \approx 1.8\times10^{-4}$. Remarkably, both the
+magnetostriction and the magnetization evolve gradually between $H_{\text{c3}}
+\approx 48$ T and $H_{\text{sat}}$, indicating that the two quantities
+consistently detect the spin-nematic phase just below the saturation. Numerical
+analyses for a weakly coupled spin-chain model reveal that the observed
+magnetostriction can overall be understood within an exchange-striction
+mechanism. Small deviations found may indicate nontrivial changes in local
+correlations associated with the field-induced phase transitions.",2010.08396v1
+2020-12-09,Spin-lattice model for cubic crystals,"We present a methodology based on the N\'{e}el model to build a classical
+spin-lattice Hamiltonian for cubic crystals capable of describing magnetic
+properties induced by the spin-orbit coupling like magnetocrystalline
+anisotropy and anisotropic magnetostriction, as well as exchange
+magnetostriction. Taking advantage of the analytical solutions of the N\'{e}el
+model, we derive theoretical expressions for the parameterization of the
+exchange integrals and N\'{e}el dipole and quadrupole terms that link them to
+the magnetic properties of the material. This approach allows to build accurate
+spin-lattice models with the desire magnetoelastic properties. We also explore
+a possible way to model the volume dependence of magnetic moment based on the
+Landau energy. This new feature can allow to consider the effects of
+hydrostatic pressure on the saturation magnetization. We apply this method to
+develop a spin-lattice model for BCC Fe and FCC Ni, and we show that it
+accurately reproduces the experimental elastic tensor, magnetocrystalline
+anisotropy under pressure, anisotropic magnetostrictive coefficients, volume
+magnetostriction and saturation magnetization under pressure at
+zero-temperature. This work could constitute a step towards large-scale
+modeling of magnetoelastic phenomena.",2012.05076v3
+2021-10-04,Spontaneous magnetization of collisionless plasma through the action of a shear flow,"We study in a fully kinetic framework the generation of seed magnetic fields
+through the Weibel instability driven in an initially unmagnetized plasma by a
+large-scale shear force. We develop an analytical model that describes the
+development of thermal pressure anisotropy via phase mixing, the ensuing
+exponential growth of magnetic fields in the linear Weibel stage, and its
+saturation when the seed magnetic fields become strong enough to instigate
+gyromotion of particles and thereby inhibit their free-streaming. The predicted
+scaling dependencies of the saturated seed fields on key parameters (e.g.,
+ratio of system scale to electron skin depth, the forcing amplitude) are
+confirmed by 3D and 2D particle-in-cell simulations using an electron-positron
+plasma. This work demonstrates the spontaneous magnetization of a collisionless
+plasma through large-scale motions as simple as a shear flow, and therefore has
+important implications for magnetogenesis in dilute astrophysical systems.",2110.01134v1
+2022-07-06,Saturated absorption technique used in Potassium microcell for magnetic field sensing,"It is demonstrated that the use of a Micrometric Thin $^{39}$K vapor Cell
+(MTC) and Saturated Absorption spectroscopy (SA) allows to form narrow atomic
+lines in transmission spectrum without unwanted Cross-Over (CO) resonances.
+Another important feature is the small characteristic magnetic field value $B_0
+= A_{hf}/\mu_B$ of $^{39}$K, significantly smaller than for Rb and Cs. As a
+consequence, decoupling of $J$ and $I$ can be observed at relatively low
+magnetic fields $\sim$300 G, which results in the formation of two groups of
+four well-spectrally-resolved and equidistantly-positioned atomic transitions
+having the same amplitude (each group corresponds to a given circular
+polarization $\sigma^\pm$) which we record using a simple experimental setup
+with a linearly polarized tunable diode-laser and a longitudinal magnetic field
+obtained with two permanent magnets. Fabrication of a MTC is much easier than
+the fabrication of the $^{39}$K nanocells used in our previous works. A simple
+method to determine the magnitude of a wide range of B-fields with a spatial
+resolution of 30 $\mu$m is presented, which is intrinsically calibrated and
+does not require a frequency reference.",2207.02703v1
+2023-08-28,Spin-wave spectral analysis in crescent-shaped ferromagnetic nanorods,"The research on the properties of spin waves (SWs) in three-dimensional
+nanosystems is an innovative idea in the field of magnonics. Mastering and
+understanding the nature of magnetization dynamics and binding of SWs at
+surfaces, edges, and in-volume parts of three-dimensional magnetic systems
+enables the discovery of new phenomena and suggests new possibilities for their
+use in magnonic and spintronic devices. In this work, we use numerical methods
+to study the effect of geometry and external magnetic field manipulations on
+the localization and dynamics of SWs in crescent-shaped (CS) waveguides. It is
+shown that changing the magnetic field direction in these waveguides breaks the
+symmetry and affects the localization of eigenmodes with respect to the static
+demagnetizing field. This in turn has a direct effect on their frequency.
+Furthermore, CS structures were found to be characterized by significant
+saturation at certain field orientations, resulting in a cylindrical
+magnetization distribution. Thus, we present chirality-based nonreciprocal
+dispersion relations for high-frequency SWs, which can be controlled by the
+field direction (shape symmetry) and its amplitude (saturation).",2308.14678v1
+2024-03-11,Effect of Ir growth pressure on the domain wall dynamics in Ta/Pt/Co/Ir/Ta stacks,"The dynamical response of magnetic domain walls to external magnetic fields
+in ultra-thin multilayer magnetic films is determined not only by the
+composition and thickness of the layers but also by the growth conditions.
+Growth conditions can induce significant structural changes inside the layers
+and at the interfaces between them, affecting in particular the dynamics of
+domain walls, their mobility, elastic tension, and the pinning forces acting on
+them. In this work, we focus specifically on the effect of Ir layer growth
+pressure in Ta/Pt/Co/Ir/Ta ultra-thin multilayers films. Measurements of the DC
+magnetic properties, domain wall velocity and domain morphology in the creep
+regime for both constant and alternating field pulses, were performed for a
+batch of samples where the Ir layer was grown at different pressures. We find
+that the saturation magnetization, the effective anisotropy constant and the
+domain wall surface tension grow with increasing pressure and saturate at a
+threshold pressure, while the Dzyaloshinskii-Moriya field and the strength of
+the disorder remain practically unaltered over the range of pressures
+considered.",2403.07141v1
+2018-09-25,Frictionless Zonal Flow Saturation by Vorticity Mixing,"Consideration of wave--flow resonance addresses the long-standing problem of
+how zonal flows (ZF) saturate in the limit of weak or zero frictional drag, and
+also determines the ZF scale. For relevant magnetic geometries, the frequently
+quoted tertiary instability requires unphysical enhancement of ZF shear and
+thus is irrelevant to the near-marginal, frictionless regime. We show that
+resonant vorticity mixing, which conserves potential enstrophy, enables ZF
+saturation in the absence of drag, and so is effective in the Dimits up-shift
+regime. Vorticity mixing is incorporated as a nonlinear, self-regulation effect
+in an extended 0D predator--prey model of drift--ZF turbulence. This analysis
+determines the saturated ZF shear and shows that the mesoscopic ZF width scales
+as $L_{ZF}\sim f^{3/16} (1-f)^{1/8} \rho_s^{5/8} l_0^{3/8}$ in the relevant
+adiabatic limit (i.e., $\tau_{ck} k_\|^2 D_\| \gg 1$). $f$ is the fraction of
+turbulence energy coupled to ZF and $l_0$ is the mixing length absent ZF
+shears. We calculate and compare the stationary flow and turbulence level in
+frictionless, weakly frictional, and strongly frictional regimes. In the
+frictionless limit, the results differ significantly from conventionally quoted
+scalings derived for frictional regimes. The flow is independent of turbulence
+intensity. The turbulence level scales as $E \sim (\gamma_L/\varepsilon_c)^2$,
+which defines the extent of the ""near-marginal"" regime to be $\gamma_L <
+\varepsilon_c$, for the case of avalanche-induced profile variability. Here,
+$\varepsilon_c$ is the rate of dissipation of potential enstrophy and
+$\gamma_L$ is the characteristic linear growth rate of fluctuations. The
+implications for dynamics near marginality of the strong scaling of saturated
+$E$ with $\gamma_L$ are discussed.",1809.09589v1
+2006-12-07,Saturation of the Magnetothermal Instability in Three Dimensions,"In dilute astrophysical plasmas, thermal conduction is primarily along
+magnetic field lines, and therefore highly anisotropic. As a result, the usual
+convective stability criterion is modified from a condition on entropy to a
+condition on temperature. For small magnetic fields or small wavenumbers,
+instability occurs in any atmosphere where the temperature and pressure
+gradients point in the same direction. We refer to the resulting convective
+instability as the magnetothermal instability (MTI). We present fully
+three-dimensional simulations of the MTI and show that saturation results in an
+atmosphere with different vertical structure, dependent upon the boundary
+conditions. When the temperature at the boundary of the unstable layer is
+allowed to vary, the temperature gradient relaxes until the unstable region is
+almost isothermal. When the temperature at the boundary of the unstable region
+is fixed, the magnetic field is reoriented to an almost vertical geometry as a
+result of buoyant motions. This case exhibits more vigorous turbulence. In both
+cases the resulting saturated heat flux is almost one-half of the value
+expected if the conduction were purely isotropic. The action of the MTI results
+in dynamical processes that lead to significant transport perpendicular to the
+initial direction of the magnetic field. The resulting magnetoconvection in
+both cases amplifies the magnetic field until it is almost in equipartition
+with sustained subsonic turbulence. These results are relevant to understanding
+measurements of the temperature profiles of the intracluster medium of clusters
+of galaxies as well as the structure of radiatively inefficient accretion
+flows.",0612195v1
+2010-11-13,Fabrication and characterization of a Ni-Mn-Ga uniaxially textured freestanding film deposited by DC magnetron sputtering,"Homogeneous freestanding films have been obtained by the direct current (DC)
+magnetron sputtering technique using a sacrificial layer. After annealing, the
+films are crystallized with a strong out-of-plane texture along the (022)
+direction. The stoichiometry of the annealed films is close to the target
+composition and leads to a martensitic transformation around 255K. The annealed
+films demonstrate ferromagnetic behavior with a Curie temperature of about
+362K. The magnetization process has been studied on the both states and during
+the martensitic transition. The saturation magnetizations have been determined
+by fitting the experimental data with a saturation approach law in the range
+1-5T. Results show the saturation magnetization of the martensite is around 10%
+higher than that of the austenite. A model based on intrinsic magnetic
+properties of each state allowing the description of the magnetization M=f (H,
+T) of such polycrystalline films during the martensitic transformation is
+presented. The mass fraction of martensite inside the austenite phase can be
+determined using this model. The shape memory effect is analyzed both by
+scanning electron microscopy and by optical microscopy with in-situ measurement
+of the resistance temperature dependence.",1011.3109v1
+2016-06-13,Stellar wind-magnetosphere interaction at exoplanets: computations of auroral radio powers,"We present calculations of the auroral radio powers expected from exoplanets
+with magnetospheres driven by an Earth-like magnetospheric interaction with the
+solar wind. Specifically, we compute the twin cell-vortical ionospheric flows,
+currents, and resulting radio powers resulting from a Dungey cycle process
+driven by dayside and nightside magnetic reconnection, as a function of
+planetary orbital distance and magnetic field strength. We include saturation
+of the magnetospheric convection, as observed at the terrestrial magnetosphere,
+and we present power law approximations for the convection potentials, radio
+powers and spectral flux densities. We specifically consider a solar-age system
+and a young (1 Gyr) system. We show that the radio power increases with
+magnetic field strength for magnetospheres with saturated convection potential,
+and broadly decreases with increasing orbital distance. We show that the
+magnetospheric convection at hot Jupiters will be saturated, and thus unable to
+dissipate the full available incident Poynting flux, such that the magnetic
+Radiometric Bode's Law (RBL) presents a substantial overestimation of the radio
+powers for hot Jupiters. Our radio powers for hot Jupiters are $\sim$5-1300 TW
+for hot Jupiters with field strengths of 0.1-10 $B_J$ orbiting a Sun-like star,
+while we find that competing effects yield essentially identical powers for hot
+Jupiters orbiting a young Sun-like star. However, in particular for planets
+with weaker magnetic fields our powers are higher at larger orbital distances
+than given by the RBL, and there are many configurations of planet that are
+expected to be detectable using SKA.",1606.03997v1
+2024-01-08,Magnetic field amplification in massive primordial halos: Influence of Lyman-Werner radiation,"The potential importance of magnetic fields during structure formation and
+gravitational collapse in the early Universe has been shown in several studies.
+In particular, magnetic field amplification by the small-scale dynamo plays an
+important role in addition to the pure amplification expected from
+gravitational collapse. In this paper, we study the small-scale dynamo for
+halos of $\gtrsim10^7$ M$_\odot$ collapsing at $z\gtrsim12$, under different
+ambient conditions due to the strength of the Lyman-Werner background.
+Additionally, we estimate the approximate saturation level by varying the
+initial magnetic field strength. We performed cosmological
+magnetohydrodynamical simulations for three distinct halos of $\sim10^7$
+M$_{\odot}$ at $z\geq13$ by varying the Jeans resolution from $32-256$ cells
+and employed Lyman Werner background flux of strengths $10^2-10^5$ in units of
+$J_{21}$, where $J_{21}=10^{-21}$ erg$/$cm$^2/$sr$/$s$/$Hz. To follow the
+chemical and thermal evolution of the gas we made use of the KROME package. In
+addition to the compression by collapse, we find magnetic field amplification
+via the dynamo both in the regimes of atomic and molecular hydrogen cooling.
+Moreover, we find a lower saturation level in the molecular hydrogen cooling
+regime. This behaviour can be understood due to the generally reduced radial
+infall velocities and vorticities in this regime, as well as the higher Mach
+numbers of the gas, which give rise to a smaller saturation ratio. Our results
+overall suggest that the dynamo operates over a large range of conditions in
+the collapsing gas.",2401.04054v1
+2023-09-22,Magnetic field amplification in cosmological zoom simulations from dwarf galaxies to galaxy groups,"Magnetic fields are ubiquitous in the Universe. Recently, cosmological
+simulations of galaxies have successfully begun to incorporate magnetic fields
+and their evolution in galaxies and their haloes. However, so far they have
+mostly focused on Milky Way-like galaxies. Here we analyse a sample of high
+resolution cosmological zoom simulations of disc galaxies in haloes with mass
+$M_\mathrm{200c}$ from $10^{10}\,\mathrm{M}_\odot$ to
+$10^{13}\,\mathrm{M}_\odot$, simulated with the Auriga galaxy formation model.
+We show that with sufficient numerical resolution the magnetic field
+amplification and saturation is converged. The magnetic field strength reaches
+equipartition with turbulent energy density for galaxies in haloes with
+$M_\mathrm{200c}\gtrsim 10^{11.5}\,\mathrm{M_\odot}$. For galaxies in less
+massive haloes, the magnetic field strength saturates at a fraction of
+equipartition that decreases with decreasing halo mass. For our lowest mass
+haloes, the magnetic field saturates significantly below $10\%$ of
+equipartition. We quantify the resolution we need to obtain converged magnetic
+field strengths and discuss our resolution requirements also in the context of
+the IllustrisTNG cosmological box simulations. We show that, at $z=0$,
+rotation-dominated galaxies in our sample exhibit for the most part an ordered
+large scale magnetic field, with fewer field reversals in more massive
+galaxies. Finally, we compare the magnetic fields in our cosmological galaxies
+at $z=0$ with simulations of isolated galaxies in a collapsing halo setup. Our
+results pave the way for detailed studies of cosmic rays and other physical
+processes in similar cosmological galaxy simulations that crucially depend on
+the strength and structure of magnetic fields.",2309.13104v2
+2007-02-01,Saturated nucleate pool boiling of oxygen under magnetically-enhanced effective gravity,"We investigate the effect of enhancing gravity on saturated nucleate pool
+boiling of oxygen for effective gravities of 1g, 6.0g, and 16g (g=9.8 m/s^2) at
+a saturation pressure of 760 torr and for heat fluxes of 10 ~ 3000 W/m^2. The
+effective gravity on the oxygen is increased by applying a magnetic body force
+generated by a superconducting solenoid. We measure the heater temperature
+(expressed as a reduced superheat) as a function of heat flux and fit this data
+to a piecewise power-law/linear boiling curve. At low heat flux (<400 W/m^2)
+the superheat is proportional to the cube root of the heat flux. At higher heat
+fluxes, the superheat is a linear function of the heat flux. To within
+statistical uncertainties, which are limited by variations among experimental
+runs, we find no variation of the boiling curve over our applied gravity range.",0702012v1
+2011-11-14,Nematic phase and phase separation near saturation field in frustrated ferromagnets,"We study the effects of quantum fluctuations in magnetic properties of
+quantum frustrated ferromagnets in a magnetic field. It is shown that a
+non-classical phase or a phase separation appears due to quantum fluctuations
+below the saturation field in a parameter range close to the classical
+zero-field phase boundary between ferromagnetic and antiferromagnetic phases,
+for the case that the classical antiferromagnetic state is not an eigenstate of
+the quantum model. As an example to which this argument is applicable, we study
+the S=1/2 J1-J2 Heisenberg model with ferromagnetic J1 (J1<0) on the bcc
+lattice using a dilute Bose gas approach. For -1.50097 < J1/J2 < -1.389,
+magnons form f-wave two-magnon bound states, leading to a spin nematic phase,
+and for -1.389 < J1/J2 < -0.48 a canted coplanar antiferromagnetic phase
+appears accompanied with a phase separation below the saturation field.",1111.3184v3
+2012-06-25,Particle simulation study of electron heating by counterstreaming ion beams ahead of supernova remnant shocks,"The growth and saturation of Buneman-type instabilities is examined with a
+particle-in-cell (PIC) simulation for parameters that are representative for
+the foreshock region of fast supernova remnant (SNR) shocks. A dense ion beam
+and the electrons correspond to the upstream plasma and a fast ion beam to the
+shock-reflected ions. The purpose of the 2D simulation is to identify the
+nonlinear saturation mechanisms, the electron heating and potential secondary
+instabilities that arise from anisotropic electron heating and result in the
+growth of magnetic fields. We confirm that the instabilities between both ion
+beams and the electrons saturate by the formation of phase space holes by the
+beam-aligned modes. The slower oblique modes accelerate some electrons, but
+they can not heat up the electrons significantly before they are trapped by the
+faster beam-aligned modes. Two circular electron velocity distributions
+develop, which are centred around the velocity of each ion beam. They develop
+due to the scattering of the electrons by the electrostatic wave potentials.
+The growth of magnetic fields is observed, but their amplitude remains low.",1206.5713v1
+2014-06-05,Numerical comparison between a Gyrofluid and Gyrokinetic model investigating collisionless magnetic reconnection,"The first detailed comparison between gyrokinetic and gyrofluid simulations
+of collisionless magnetic reconnection has been carried out. Both the linear
+and nonlinear evolution of the collisionless tearing mode have been analyzed.
+In the linear regime, we have found a good agreement between the two approaches
+over the whole spectrum of linearly unstable wave numbers, both in the drift
+kinetic limit and for finite ion temperature. Nonlinearly, focusing on the
+small-$\Delta '$ regime, with $\Delta '$ indicating the standard tearing
+stability parameter, we have compared relevant observables such as the
+evolution and saturation of the island width, as well as the island oscillation
+frequency in the saturated phase.The results are basically the same, with small
+discrepancies only in the value of the saturated island width for moderately
+high values of $\Delta '$. Therefore, in the regimes investigated here, the
+gyrofluid approach can describe the collisionless reconnection process as well
+as the more complete gyrokinetic model.",1406.1334v1
+2016-01-27,Coherent population oscillation produced by saturating probe and pump fields on the intercombination Line,"We present a theoretical study of the experiments on coherent population
+oscillations and coher- ent population trapping on the intercombination line of
+174Y b. The transition involves a change of the spin and thus can not be
+interpreted in terms of an effective Lambda system. The reported experiments
+are done in the regime where both pump and probe fields can saturate the
+transition. We demonstrate by both numerical and analytical calculations the
+appearance of the interference minimum as both pump and probe start saturating
+the transition. We present an analytical result for the threshold probe power
+when the interference minimum can appear. We also present de- tailed study of
+the appearance of the interference minimum when magnetic fields are applied.
+The magnetic fields not only create Zeeman splittings but in addition make the
+system open because of the couplings to other levels. We show the possibility
+of interference minimum at the position of subharmonic resonances.",1601.07786v1
+2016-09-14,On the possibility of helicity oscillations in the saturation of the Tayler instability,"Recent numerical results of current-driven instabilities at low magnetic
+Prandtl number and high Hartmann number support the possibility of a saturation
+state characterized by helicity oscillations. We investigate the underlying
+mechanism by analyzing this possibility using an higher-order Landau-Ginzburg
+effective Lagrangian for the weakly non-linear amplitude dynamics, where the
+magnetic and velocity perturbations are linearly dependent. We find that, if
+the mirror symmetry between left- and right-handed modes is spontaneously
+broken, it is impossible to achieve an oscillating helical state. We argue that
+the result is likely to hold also adding higher-order terms and in the presence
+of an explicit symmetry breaking. We conclude that an oscillating saturating
+state for the Tayler instability is unlikely to depend on the interaction of
+chiral modes.",1610.00616v2
+2018-07-02,A-priori study of the subgrid energy transfers for small-scale dynamo in kinematic and saturation regimes,"The statistical properties of the subgrid energy transfers of homogeneous
+small-scale dynamo are investigated during the kinematic, nonlinear and
+statistically saturated stages. We carry out an a priori analysis of data
+obtained from an ensemble of direct numerical simulations on $512^3$ grid
+points and at unity magnetic Prandtl number. In order to provide guidance for
+subgrid-scale (SGS) modelling of different types of energy transfer that occur
+in magnetohydrodynamic dynamos, we consider the SGS stress tensors originating
+from inertial dynamics, Lorentz force and the magnetic induction separately. We
+find that all SGS energy transfers display some degree of intermittency as
+quantified by the scale-dependence of their respective probability density
+functions. Concerning the inertial dynamics, a depletion of intermittency
+occurs in presence of a saturated dynamo.",1807.00759v2
+2018-07-14,Thermally assisted skyrmions creation in Pt/Co/Ta multilayer films,"N\'eel-type magnetic skyrmions in multilayer films have attracted significant
+amount of attention recently for their stability at room temperature and
+capability of motion driven by a low-density electrical current, which can be
+potentially applied to spintronic devices. However, the thermal effect on the
+formation of the skyrmions and their behavior has rarely been studied. Here, we
+report a study on the creation of skyrmions in [Pt/Co/Ta]10 multilayer samples
+at different temperatures using an in-situ Lorentz transmission electron
+microscopy. By imaging the magnetization reversal process from positive
+(negative) saturation to negative (positive) saturation, we found that the
+skyrmions can be created by nucleation from ferromagnetic saturation state and
+by breaking the labyrinth domains under certain external fields. By tuning the
+external fields, a maximum density of skyrmions was reached at different
+temperatures. The key finding is that the creation of the skyrmions in the
+multilayers depends critically on the temperature and thermal history.",1807.05335v1
+2022-06-22,Accurate finite-difference micromagnetics of magnets including RKKY interaction -- analytical solution and comparison to standard micromagnetic codes,"Within this paper we show the importance of accurate implementations of the
+RKKY interactions for antiferromagnetically coupled ferromagnetic layers with
+thicknesses exceeding the exchange length. In order to evaluate the performance
+of different implementations of RKKY interaction, we develop a benchmark
+problem by deriving the analytical formula for the saturation field of two
+infinitely thick magnetic layers that are antiparallelly coupled. This
+benchmark problem shows that state-of-the-art implementations in commonly used
+finite-difference codes lead to errors of the saturation field that amount to
+more than 20% for mesh sizes of 2 nm which is well below the exchange length of
+the material. In order to improve the accuracy, we develop higher order cell
+based and nodal based finite-difference codes that significantly reduce the
+error compared to state-of-the-art implementations. For the second order cell
+based and first order nodal based finite element approach the error of the
+saturation field is reduced by about a factor of 10 (2% error) for the same
+mesh size of 2 nm.",2206.11063v1
+2022-09-16,Magnetohydrodynamic Simulations of the Tayler Instability in Rotating Stellar Interiors,"The Tayler instability is an important but poorly studied magnetohydrodynamic
+instability that likely operates in stellar interiors. The nonlinear saturation
+of the Tayler instability is poorly understood and has crucial consequences for
+dynamo action and angular momentum transport in radiative regions of stars. We
+perform three-dimensional MHD simulations of the Tayler instability in a
+cylindrical geometry, including strong buoyancy and Coriolis forces as
+appropriate for its operation in realistic rotating stars. The linear growth of
+the instability is characterized by a predominantly $m=1$ oscillation with
+growth rates roughly following analytical expectations. The non-linear
+saturation of the instability appears to be caused by secondary shear
+instabilities and is also accompanied by a morphological change of the flow. We
+argue, however, that non-linear saturation likely occurs via other mechanisms
+in real stars where the separation of scales is larger than those reached by
+our simulations. We also observe dynamo action via the amplification of the
+axisymmetric poloidal magnetic field, suggesting that Tayler instability could
+be important for magnetic field generation and angular momentum transport in
+the radiative regions of evolving stars.",2209.08104v2
+2024-01-10,Narrowly avoided spin-nematic phase in BaCdVO(PO$_4$)$_2$: NMR evidence,"We present a $^{31}$P nuclear magnetic resonance (NMR) investigation of
+BaCdVO(PO$_4$)$_2$ focusing on the nearly saturated regime between
+$\mu_0H_{c1}$ = 4.05 T and $\mu_0H_{c2}$ = 6.5 T, used to be considered as a
+promising candidate for a spin-nematic phase. NMR spectra establish the absence
+of any dipolar order there, whereas the weak field dependence of the
+magnetization above $H_{c1}$ is accounted for by Dzyaloshinskii-Moriya
+interaction terms. The low-energy spin dynamics (fluctuations), measured by
+nuclear spin-lattice relaxation rate ($T_1^{-1}$), confirms the continuity of
+this phase and the absence of any low-temperature phase transition.
+Unexpectedly, the spin dynamics above $H_{c1}$ is largely dominated by
+two-magnon processes, which is expected above the saturation field of a
+spin-nematic phase, but not inside. This shows that BaCdVO(PO$_4$)$_2$ is
+indeed close to a spin-nematic instability, however, this phase is not
+stabilized. We thus confirm recent theoretical predictions that the
+spin-nematic phase can be stabilized, at most, in an extremely narrow field
+range close to saturation or is rather narrowly avoided [Jiang et al., Phys.
+Rev. Lett. 130, 116701 (2023)].",2401.05269v1
+2017-07-28,Limits on Magnetic Field Amplification from the r-Mode Instability,"At second order in perturbation theory, the unstable r-mode of a rotating
+star includes growing differential rotation whose form and growth rate are
+determined by gravitational-radiation reaction. With no magnetic field, the
+angular velocity of a fluid element grows exponentially until the mode reaches
+its nonlinear saturation amplitude and remains nonzero after saturation. With a
+background magnetic field, the differential rotation winds up and amplifies the
+field, and previous work where large mode amplitudes were considered suggests
+that the amplification may damp out the instability. A background magnetic
+field, however, turns the saturated time-independent perturbations
+corresponding to adding differential rotation into perturbations whose
+characteristic frequencies are of order the Alfv\'en frequency. As found in
+previous studies, we argue that magnetic- field growth is sharply limited by
+the saturation amplitude of an unstable mode. In contrast to previous work,
+however, we show that if the amplitude is small, i.e., of order 10^(-4), then
+the limit on the magnetic-field growth is stringent enough to prevent the loss
+of energy to the magnetic field from damping or significantly altering an
+unstable r-mode in nascent neutron stars with normal interiors and in cold
+stars whose interiors are type II superconductors. We show this result first
+for a toy model, and we then obtain an analogous upper limit on magnetic field
+growth using a more realistic model of a rotating neutron star. Our analysis
+depends on the assumption that there are no marginally unstable perturbations,
+and this may not hold when differential rotation leads to a magnetorotational
+instability.",1707.09419v2
+2004-10-21,Novel magnetic behavior of single crystalline Er2PdSi3,"We report the results of ac and dc magnetic susceptibility (chi) and
+electrical resistivity (rho) measurements on the single crystals of Er2PdSi3,
+crystallizing in an AlB2-derived hexagonal structure, for two orientations
+H//[0001] and H//[2 -1 -1 0]. For H//[0001], there are apparently two magnetic
+transitions as revealed by the ac chi data, one close to 7 K attributable to
+antiferromagnetic ordering and the other around 2 K. However, for H // [2 -1 -1
+0], we observe additional features above 7 K (near 11 and 23 K) in the plot of
+low-field chi(T); also, there is no corresponding anomaly in the rho(T) plot.
+In this respect, the magnetic behavior of this compound is novel, particularly
+while compared with other members of this series. The features in ac chi
+respond differently to the application of a small dc magnetic field for the two
+directions. As far as low temperature (T= 1.8 and 5 K) isothermal magnetization
+(M) behaviour is concerned, it exhibits meta-magnetic-like features around 2
+kOe saturating at high fields for the former orientation, whereas for the
+latter, there is no saturation even at 120 kOe. The sign of paramagnetic Curie
+temperature is different for these two directions. Thus, there is a strong
+anisotropy in the magnetic behavior. However, interestingly, the rho(T) plots
+are found to be essentially isotropic, with the data revealing possible
+formation of magnetic superzone formation below 7 K.",0410532v1
+2009-02-15,Magnetic phase diagram of the dimerized spin $S=1/2$ ladder,"The ground-state magnetic phase diagram of a spin $S=1/2$ two-leg ladder with
+alternating rung exchange $J_{\perp}(n)=J_{\perp}[1 + (-1)^{n} \delta]$ is
+studied using the analytical and numerical approaches. In the limit where the
+rung exchange is dominant, we have mapped the model onto the effective quantum
+sine-Gordon model with topological term and identified two quantum phase
+transitions at magnetization equal to the half of saturation value from a
+gapped to the gapless regime. These quantum transitions belong to the
+universality class of the commensurate-incommensurate phase transition. We have
+also shown that the magnetization curve of the system exhibits a plateau at
+magnetization equal to the half of the saturation value. We also present a
+detailed numerical analysis of the low energy excitation spectrum and the
+ground state magnetic phase diagram of the ladder with rung-exchange
+alternation using Lanczos method of numerical diagonalizations for ladders with
+number of sites up to N=28. We have calculated numerically the magnetic field
+dependence of the low-energy excitation spectrum, magnetization and the on-rung
+spin-spin correlation function. We have also calculated the width of the
+magnetization plateau and show that it scales as $\delta^{\nu}$, where critical
+exponent varies from $\nu =0.87\pm0.01$ in the case of a ladder with isotropic
+antiferromagnetic legs to $\nu =1.82\pm0.01 $ in the case of ladder with
+ferromagnetic legs. Obtained numerical results are in an complete agreement
+with estimations made within the continuum-limit approach.",0902.2530v2
+2009-08-05,Characteristic Lengths of Magnetic Field in Magnetohydrodynamic Turbulence,"In the framework of turbulence dynamo, flow motions amplify a weak seed
+magnetic field through the stretching of field lines. Although the
+amplification process has been a topic of active research, less attention has
+been paid to the length scales of magnetic field. In this paper, we described a
+numerical study on characteristic lengths of magnetic field in
+magnetohydrodynamic turbulence. We considered the case of very weak or zero
+mean magnetic field, which is applicable to the turbulence in the intergalactic
+space. Our findings are as follows. (1) At saturation, the peak of magnetic
+field spectrum occurs at $\sim L_0/2$, where $L_0$ is the energy injection
+scale, while the most energy containing scale is $\sim L_0/5$. The peak scale
+of spectrum of projected, two-dimensional field is $\sim L_0$. (2) During the
+stage of magnetic field amplification, the energy equipartition scale shows a
+power-law increase of $\sim t^{1.5}$, while the integral and curvature scales
+show a linear increase. The equipartition, integral, and curvature scales
+saturate at $\sim L_0$, $\sim 0.3L_0$, and $\sim 0.15L_0$, respectively. (3)
+The coherence length of magnetic field defined in the Faraday rotation measure
+(RM) due to the intergalactic magnetic field (IGMF) is related to the integral
+scale. We presented a formula that expresses the standard deviation of RM,
+$\sigma_{RM}$, in terms of the integral scale and rms strength of the IGMF, and
+estimated that $\sigma_{RM}$ would be $\sim 100$ and $\sim$ a few rad m$^{-2}$
+for clusters and filaments, respectively.",0908.0610v2
+2014-10-21,Neutron Reflectometry Studies on Magnetic Stripe Domains in Permalloy/Superconductor bilayers,"We explored changes in magnetic domain structures in a magnetic layer due to
+the onset of the superconductivity of an adjacent superconductive layer using
+neutron reflectometry. Magnetic domain structures in 1~$\mu$m thick permalloy
+(Py) films were studied as functions of magnetic field, temperature and under
+the influence of the onset of superconductivity in a neighboring layer. Bragg
+peaks in the off-specular scattering were observed at low fields following
+saturation with an in-plane field, which are attributed to the quasi-parallel
+magnetic stripes along the field direction. During the magnetization reversal
+from saturation, the stripe pattern shows increases in the period, the
+transverse coherence length (\textit{i.e.}, perpendicular to the stripes) and
+the amplitude of the out-of-plane magnetization component. The coherence length
+of the magnetic stripes is anisotropic in the remnant state with the
+longitudinal coherence length (\textit{i.e.}, along the stripes) being larger
+than the transverse one. The stripe period shows a weak temperature dependence
+between 300~K and 3~K, but no abrupt change in the period is observed when the
+temperature crosses the superconducting critical temperature.",1410.5520v1
+2020-03-31,Magnetic properties of Co/Ni-based multilayers with Pd and Pt insertion layers,"In this study, the influence of Pd and Pt insertion layers in Co/Ni
+multilayers (MLs) on their magnetic properties, e.g. magnetic anisotropies,
+saturation magnetization, coercivity, magnetic domain size, and Curie
+temperature, is investigated. We compare three series of [Co/Ni/X]N ML systems
+(X = Pd, Pt, no insertion layer), varying the individual Co layer thickness as
+well as the repetition number N. All three systems behave very similarly for
+the different Co layer thicknesses. For all systems, a maximum effective
+magnetic anisotropy was achieved for MLs with a Co layer thickness between 0.15
+nm and 0.25 nm. The transition from an out-of-plane to an in-plane system
+occurs at about 0.4 nm of Co. While [Co(0.2 nm)/Ni(0.4 nm)]N MLs change their
+preferred easy magnetization axis from out-of-plane to in-plane after 6 bilayer
+repetitions, insertion of Pd and Pt results in an extension of this transition
+beyond 15 repetitions. The maximum effective magnetic anisotropy was more than
+doubled from 105 kJ/m3 for [Co/Ni]3 to 275 and 186 kJ/m3 for Pt and Pd,
+respectively. Furthermore, the insertion layers strongly reduce the initial
+saturation magnetization of 1100 kA/m of Co/Ni MLs and lower the Curie
+temperature from 720 to around 500 K",2003.14306v1
+2020-04-17,Reversible and magnetically unassisted voltage-driven switching of magnetization in FeRh/PMN-PT,"Reversible control of magnetization by electric fields without assistance
+from a subsidiary magnetic field or electric current could help reduce the
+power consumption in spintronic devices. When increasing temperature above room
+temperature, FeRh displays an uncommon antiferromagnetic to ferromagnetic phase
+transition linked to a unit cell volume expansion. Thus, using the strain
+exerted by an adjacent piezoelectric layer, the relative amount of
+antiferromagnetic and ferromagnetic regions can be tuned by an electric field
+applied to the piezoelectric material. Indeed, large variations in the
+saturation magnetization have been observed when straining FeRh films grown on
+suitable piezoelectric substrates. In view of its applications, the variations
+in the remanent magnetization rather than those of the saturation magnetization
+are the most relevant. Here, we show that in the absence of any bias external
+magnetic field, permanent and reversible magnetization changes as high as 34%
+can be induced by an electric field, which remain after this has been zeroed.
+Bulk and local magnetoelectric characterization reveals that the fundamental
+reason for the large magnetoelectric response observed at remanence is the
+expansion (rather than the nucleation) of ferromagnetic nanoregions.",2004.08087v1
+2020-08-12,Solar dynamo cycle variations with a rotational period,"Using the non-linear mean-field dynamo models we calculate the magnetic cycle
+parameters, like the dynamo cycle period, the amplitude of the total magnetic
+energy, and the Poynting flux luminosity from the surface for the solar analogs
+with rotation periods of range from 1 to 30 days. We do simulations both for
+the kinematic and non-kinematic dynamo models. The kinematic dynamo models,
+which take into account the non-linear $\alpha$-effect and the loss of the
+magnetic flux due to magnetic buoyancy, show a decrease of the magnetic cycle
+with the decrease of the stellar rotation period. The stars with a rotational
+period of less than 10 days show the non-stationary long-term variations of the
+magnetic activity. The non-kinematic dynamo models take into account the
+magnetic field feedback on the large-scale flow and heat transport inside the
+convection zone. They show the non-monotonic variation of the dynamo period
+with the rotation rate. The models for the rotational periods fewer than 10
+days show the non-stationary evolution with a slight increase in the primary
+dynamo period with the increase of the rotation rate. The non-kinematic models
+show the growth of the dynamo generated magnetic flux with the increase of the
+rotation rate. There is a dynamo saturation for the star rotating with a period
+of two days and less. The saturation of the magnetic activity parameters is
+accompanied by depression of the differential rotation.",2008.05083v3
+2022-10-19,Three-dimensional numerical simulations of ambipolar diffusion in NS cores in the one-fluid approximation: instability of poloidal magnetic field,"We numerically model evolution of magnetic fields inside a neutron star under
+the influence of ambipolar diffusion in the weak-coupling mode in the one-fluid
+MHD approximation. Our simulations are three-dimensional and performed in
+spherical coordinates. Our model covers the neutron star core and includes
+crust where the magnetic field decay is due to Ohmic decay. We discover an
+instability of poloidal magnetic field under the influence of ambipolar
+diffusion. This instability develops in the neutron star core and grows on a
+timescale of 0.2 dimensionless times, reaching saturation by 2 dimensionless
+times. The instability leads to formation of azimuthal magnetic field with
+azimuthal wavenumber $m=14$ (at the moment of saturation) which keeps merging
+and reaches $m=4$ by 16 dimensionless times. Over the course of our simulations
+(16 dimensionless times) the surface dipolar magnetic field decays, reaching 20
+percent of its original value and keeps decaying. The decay timescale for the
+total magnetic energy is six dimensionless times. The ambipolar diffusion
+induces electric currents in the crust where these currents dissipate
+efficiently. Strong electric currents in the crust lead to heating, which could
+correspond to luminosities of $\approx 10^{29}$ erg s$^{-1}$ during hundreds of
+Myrs for an initial magnetic field of $10^{14}$ G. Ambipolar diffusion leads to
+formation of small-scale magnetic fields at the neutron star surface.",2210.10869v1
+2023-09-18,Computational Exploration of Magnetic Saturation and Anisotropy Energy for Nonstoichiometric Ferrite Compositions,"A grand challenge in materials research is identifying the relationship
+between composition and performance. Herein, we explore this relationship for
+magnetic properties, specifically magnetic saturation (M$_s$) and magnetic
+anisotropy energy (MAE) of ferrites. Ferrites are materials derived from
+magnetite (which has the chemical formulae Fe$_3$O$_4$) that comprise metallic
+elements in some combination such as Fe, Mn, Ni, Co, Cu and Zn. They are used
+in a variety of applications such as electromagnetism, magnetic hyperthermia,
+and magnetic imaging. Experimentally, synthesis and characterization of
+magnetic materials is time consuming. In order to create insight to help guide
+synthesis, we compute the relationship between ferrite composition and magnetic
+properties using density functional theory (DFT). Specifically, we compute
+M$_s$ and MAE for 571 ferrite structures with the formulae
+M1$_x$M2$_y$Fe$_{3-x-y}$O$_4$, where M1 and M2 can be Mn, Ni, Co, Cu and/or Zn
+and 0 $\le$ x $\le$ 1 and y = 1 - x. By varying composition, we were able to
+vary calculated values of M$_s$ and MAE by up to 9.6$\times$10$^5$ A m$^{-1}$
+and 14.1$\times$10$^5$ J m$^{-3}$, respectively. Our results suggest that
+composition can be used to optimize magnetic properties for applications in
+heating, imaging, and recording. This is mainly achieved by varying M$_s$, as
+these applications are more sensitive to variation in M$_s$ than MAE.",2309.09754v1
+2024-01-18,Amplification and saturation of turbulent magnetic field in collapsing primordial gas clouds,"Recent numerical studies suggest that magnetic fields play an important role
+in primordial star formation in the early universe. However, the detailed
+evolution of the magnetic field in the collapse phase still has uncertainties
+because of the complicated physics associated with turbulence in a collapsing
+magnetized system. Here, we perform a suite of numerical MHD simulations that
+follow the collapse of magnetized, turbulent primordial gas clouds to
+investigate the evolution of the magnetic field associated with the turbulence,
+assuming a polytropic equation of state with exponent $\gamma_{\rm eff}$ and
+with various numerical resolutions. In addition, we generalize the analytic
+theory of magnetic field growth/saturation so that it can deal with various
+exponents $\gamma_{\rm eff}$ and turbulence energy spectra. We find that the
+numerical results are well reproduced by the theory for various $\gamma_{\rm
+eff}$ through the collapse phase during the formation of the first stars. The
+magnetic field is eventually amplified by a factor of $10^{12}$ -- $10^{15}$
+due to kinematic and non-linear turbulent dynamo effects and reaches 3% -- 100%
+of the equipartition level, depending on $\gamma_{\rm eff}$. We also find that
+the transition between the kinematic and non-linear stages can be analytically
+estimated. These results indicate that the strong magnetic field accompanied by
+supersonic turbulence is a general property and suggest that it can play a
+crucial role in the formation of the first stars.",2401.09739v1
+2020-07-26,Effect of the anomalous magnetic moment of quarks on magnetized QCD matter and meson spectra,"We systematically investigate the effect of the anomalous magnetic
+moment(AMM) of quarks on the magnetized QCD matter, including the magnetic
+susceptibility, the inverse magnetic catalysis around the critical temperature
+and the neutral/charged pion and rho meson spectra under magnetic fields. The
+dynamical AMM of quarks, its coupling with magnetic field causes Zeeman
+splitting of the dispersion relation of quarks thus changes the magnetism
+properties and meson mass spectra under magnetic fields. It is found that
+including the AMM of quarks cannot fully understand lattice results of the
+magnetized matter: The AMM of quarks reduces the dynamical quark mass thus
+causes the inverse magnetic catalysis around $T_c$. The neutral pion mass is
+very sensitive to the AMM, it decreases with magnetic field quickly, and the
+charged pion mass shows a nonlinear behavior, i.e., firstly linearly increases
+with the magnetic field and then saturates at strong magnetic field. For rho
+meson, it is observed that AMM reduces the mass of neutral rho meson mass with
+different $s_z$, and reduces the mass of $s_z=+1,0$ component charged rho meson
+mass but enhances the $s_z=-1$ component charged rho meson mass. The magnetic
+susceptibility at low temperature can be either positive or negative with
+different AMM.",2007.13122v3
+2024-03-23,Engineering the electronic and magnetic properties of monolayer TiS$_2$ through systematic transition-metal doping,"Layered materials that exhibit magnetic ordering in their pristine form are
+very rare. Several standard approaches, such as adsorption of atoms,
+introduction of point defects, and edge engineering, have been developed to
+induce magnetism in two-dimensional materials. In this way, we investigate the
+electronic and magnetic properties of monolayer TiS$_2$ doped with 3$d$
+transition metals (TMs) atoms in both octahedral 1T and trigonal prismatic 1H
+structures using first-principles calculations. In its pristine form, TiS$_2$
+is a non-magnetic semiconductor. The bands near the Fermi energy primarily
+exhibit $d$ orbital characters, and due to the presence of ideal octahedral and
+trigonal arrangements, they are well separated from other bands with $p$
+character. Upon substituting 3$d$-TM atoms in both structures, a variety of
+electronic and magnetic phases emerge, including magnetic semiconductor,
+magnetic half-metal, non-magnetic metal, and magnetic metal. Chromium exhibits
+the largest magnetic moment in both the 1T and 1H structures. The 1T structure
+shows a slightly higher magnetic moment of 3.419 $\mu_B$ compared to the 1H
+structure 3.138 $\mu_B$, attributed to the distorted octahedral structure of
+the 1T structure. Unlike pristine TiS$_2$, the deficiency in saturation of
+neighboring S atoms in the presence of impurities leads to the proximity of
+energy levels of $d$ and $p$ states, resulting in unexpectedly sizable magnetic
+moments. Another interesting case is Cobalt, which leads to a magnetic moment
+of approximately 0.805 $\mu_B$ in the 1H structure, while the Co exhibits a
+non-magnetic state in the 1H structure. These materials demonstrate a high
+degree of tunability and can be optimized for various magnetic applications.",2403.15850v1
+2002-06-16,Nonlinear Turbulent Magnetic Diffusion and Mean-Field Dynamo,"The nonlinear coefficients defining the mean electromotive force (i.e., the
+nonlinear turbulent magnetic diffusion, the nonlinear effective velocity, the
+nonlinear kappa-tensor, etc.) are calculated for an anisotropic turbulence. A
+particular case of an anisotropic background turbulence (i.e., the turbulence
+with zero mean magnetic field) with one preferential direction is considered.
+It is shown that the toroidal and poloidal magnetic fields have different
+nonlinear turbulent magnetic diffusion coefficients. It is demonstrated that
+even for a homogeneous turbulence there is a nonlinear effective velocity which
+exhibits diamagnetic or paramagnetic properties depending on anisotropy of
+turbulence and level of magnetic fluctuations in the background turbulence.
+Analysis shows that an anisotropy of turbulence strongly affects the nonlinear
+mean electromotive force. Two types of nonlinearities (algebraic and dynamic)
+are also discussed. The algebraic nonlinearity implies a nonlinear dependence
+of the mean electromotive force on the mean magnetic field. The dynamic
+nonlinearity is determined by a differential equation for the magnetic part of
+the alpha-effect. It is shown that for the alpha-Omega axisymmetric dynamo the
+algebraic nonlinearity alone cannot saturate the dynamo generated mean magnetic
+field while the combined effect of the algebraic and dynamic nonlinearities
+limits the mean magnetic field growth. Astrophysical applications of the
+obtained results are discussed.",0206261v1
+2006-11-04,Cotunneling and non-equilibrium magnetization in magnetic molecular monolayers,"Transport and non-equilibrium magnetization in monolayers of magnetic
+molecules subject to a bias voltage are considered. We apply a master-equation
+approach going beyond the sequential-tunneling approximation to study the
+Coulomb-blockade regime. While the current is very small in this case, the
+magnetization shows changes of the order of the saturation magnetization for
+small variations of the bias voltage. Inelastic cotunneling processes manifest
+themselves as differential-conductance steps, which are accompanied by much
+larger changes in the magnetization. In addition, the magnetization in the
+Coulomb-blockade regime exhibits strong signatures of sequential tunneling
+processes de-exciting molecular states populated by inelastic cotunneling. We
+also consider the case of a single molecule, finding that cotunneling processes
+lead to the occurrence of magnetic sidebands below the Coulomb-blockade
+threshold. In the context of molecular electronics, we study how additional
+spin relaxation suppresses the fine structure in transport and magnetization.",0611108v2
+2008-10-01,Lattice disorder and Ferromagnetism in La0.67Ca0.33MnO3 nanoparticle,"We study the ferromagnetism of La0.67Ca0.33MnO3 in bulk polycrystalline,
+nanocrystalline and amorphous phase. The structural change from crystalline
+phase to amorphous phase exhibited a systematic decrease of TC(paramagnetic to
+ferromagnetic transition temperature) and spontaneous magnetization (MS). The
+experimental results suggested few more features, e.g., appearance of large
+magnetic irreversibility in the temperature dependence of magnetization, lack
+of magnetic saturation at high magnetic field, blocking of magnetization below
+TB, and enhancement of coercivity. In addition, the magnetic phase transition
+near to TC has changed from first order character in bulk sample to second
+order character in nanocrystalline and amorphous samples. We understand the
+observed magnetic features as the effects of decreasing particle size and
+increasing magnetic (spin- lattice) disorder. We noted that magnetic dynamics
+of amorphous samples is distinctly different from the nanocrystalline samples.
+The ferromagnetism of amorphous samples are comparable with the properties of
+reported amorphous ferromagnetic nanoparticles. We also demonstrate the effect
+of disorder shell in controlling the dynamics of ferromagnetic cores.",0810.0090v1
+2012-08-08,Magnetic properties of charged spin-1 Bose gases with ferromagnetic coupling,"Magnetic properties of a charged spin-1 Bose gas with ferromagnetic
+interactions is investigated within mean-field theory. It is shown that a
+competition between paramagnetism, diamagnetism and ferromagnetism exists in
+this system. It is shown that diamagnetism, being concerned with spontaneous
+magnetization, cannot exceed ferromagnetism in very weak magnetic field. The
+critical value of reduced ferromagnetic coupling of paramagnetic phase to
+ferromagnetic phase transition $\bar I_{c}$ increases with increasing
+temperature. The Lande-factor $g$ is introduced to describe the strength of
+paramagnetic effect which comes from the spin degree of freedom. The
+magnetization density $\bar M$ increases monotonically with $g$ for fixed
+reduced ferromagnetic coupling $\bar I$ as $\bar I>\bar I_{c}$. In a weak
+magnetic field, ferromagnetism makes immense contribution to the magnetization
+density. While at a high magnetic field, the diamagnetism inclines to saturate.
+Evidence for condensation can be seen in the magnetization density at weak
+magnetic field.",1208.1580v1
+2013-04-11,Theory of magnetic small-angle neutron scattering of two-phase ferromagnets,"Based on micromagnetic theory we have derived analytical expressions for the
+magnetic small-angle neutron scattering (SANS) cross section of a two-phase
+particle-matrix-type ferromagnet. The approach---valid close to magnetic
+saturation---provides access to several features of the spin structure such as
+perturbing magnetic anisotropy and magnetostatic fields. Depending on the
+applied magnetic field and on the magnitude $H_p$ of the magnetic anisotropy
+field relative to the magnitude $\Delta M$ of the jump in the longitudinal
+magnetization at the particle-matrix interface, we observe a variety of angular
+anisotropies in the magnetic SANS cross section. In particular, the model
+explains the ""clover-leaf""-shaped angular anisotropy which was previously
+observed for several nanostructured magnetic materials, and it provides access
+to the magnetic interaction parameters such as the average exchange-stiffness
+constant. It is also shown that the ratio $H_p / \Delta M$ decisively
+determines the asymptotic power-law exponent and the range of spin-misalignment
+correlations.",1304.3214v1
+2013-04-23,Interfacial tuning of perpendicular magnetic anisotropy and spin magnetic moment in CoFe/Pd multilayers,"We report on a strong perpendicular magnetic anisotropy in [CoFe 0.4nm/Pd t]6
+(t = 1.0-2.0 nm) multilayers fabricated by DC sputtering in a ultrahigh vacuum
+chamber. Saturation magnetization, $M_s$, and uniaxial anisotropy, $K_u$, of
+the multilayers decrease with increasing the spacing thickness, with a $M_s$ of
+155 emu/cc and a $K_u$ of 1.14$\times 10^5$ J/m$^3$ at a spacing thickness of t
+= 2 nm. X-ray absorption spectroscopy and X-ray magnetic circular dichroism
+measurements reveal that spin and orbital magnetic moments of Co and Fe in CoFe
+film decrease as function of Pd thickness, indicating the major contribution of
+surface/interfacial magnetism to the magnetic properties of the film.",1304.6156v2
+2013-06-27,Amorphous GdFeCo Films Exhibiting Large and Tunable Perpendicular Magnetic Anisotropy,"We report the compositional and temperature dependence of magnetic
+compensation in amorphous GdFeCo films. Magnetic compensation is attributed to
+the competition between antiferromagnetic coupling of rare-earth with
+transition-metal (TM) ions and ferromagnetic interaction between the TM ions.
+The low-Gd region from 20 to 34 at. % was found to exhibit compensation
+phenomena characterized by a low saturation magnetization and perpendicular
+magnetic anisotropy (PMA) near the compensation temperature. Compensation
+temperature was not observed in previously unreported high-Gd region from 52 to
+59 at. %, in qualitative agreement with results from recent model calculations.
+However, low magnetization was achieved at room temperature, accompanied by a
+large PMA with coercivity reaching ~6.6 kOe. The observed perpendicular
+magnetic anisotropy of amorphous GdFeCo films probably has a structural origin
+consistent with certain aspects of the atomic-scale anisotropy. Our findings
+have broadened the composition range of transition metal-rare earth alloys for
+designing PMA films, making it attractive for tunable magnetic anisotropy in
+nanoscale devices.",1306.6451v1
+2014-05-22,Zero-Temperature Configurations of Short Odd-Numbered Classical Spin Chains with Bilinear and Biquadratic Exchange Interactions,"The lowest energy configurations of short odd open chains with classical
+spins are determined for antiferromagnetic bilinear and biquadratic
+nearest-neighbor exchange interactions. The zero field residual magnetization
+generates differences with the magnetic behavior of even chains, as the odd
+chain is like a small magnet for weak magnetic fields. The lowest energy
+configuration is calculated as a function of the total magnetization M, even
+for M less than the zero field residual magnetization. Analytic expressions and
+their proofs are provided for the threshold magnetic field needed to drive the
+system away from the antiferromagnetic configuration and the spin polar angles
+in its vicinity, when the biquadratic interaction is relatively weak. They are
+also given for the saturation magnetic field and the spin polar angles close to
+it. Finally, an analytic expression along with its proof is given for the
+maximum magnetization in zero magnetic field for stronger biquadratic
+interaction, where the lowest energy configuration is highly degenerate.",1405.5931v2
+2014-12-02,Third-order effect in magnetic small-angle neutron scattering by a spatially inhomogeneous medium,"Magnetic small-angle neutron scattering (SANS) is a powerful tool for
+investigating nonuniform magnetization structures inside magnetic materials.
+Here, considering a ferromagnetic medium with weakly inhomogeneous uniaxial
+magnetic anisotropy, saturation magnetization, and exchange stiffness, we
+derive the second-order (in the amplitude of the inhomogeneities) micromagnetic
+solutions for the equilibrium magnetization textures and compute the
+corresponding magnetic SANS cross sections up to the next, third order. We find
+that in the case of perpendicular scattering (the incident neutron beam is
+perpendicular to the applied magnetic field) if twice the cross section along
+the direction orthogonal to both the field and the neutron beam is subtracted
+from the cross section along the field direction, the result has only a
+third-order contribution (the lower-order terms are canceled). This difference
+does not depend on the amplitude of the exchange inhomogeneities and provides a
+separate gateway for a deeper analysis of the sample's magnetic structure. We
+derive and analyze analytical expressions for the dependence of this
+combination on the scattering-vector magnitude for the case of spherical
+Gaussian inhomogeneities.",1412.1059v1
+2015-10-15,Magnetization process of spin-1/2 Heisenberg antiferromagnets on a layered triangular lattice,"We study the magnetization process of the spin-1/2 antiferromagnetic
+Heisenberg model on a layered triangular lattice by means of a numerical
+cluster mean-field method with a scaling scheme (CMF+S). It has been known that
+antiferromagnetic spins on a two-dimensional (2D) triangular lattice with
+quantum fluctuations exhibit a one-third magnetization plateau in the
+magnetization curve under magnetic field. We demonstrate that the CMF+S
+quantitatively reproduces the magnetization curve including the stabilization
+of the plateau. {We also discuss the effects of a finite interlayer coupling,
+which is unavoidable in real quasi-2D materials. It has been recently argued
+for a model of the layered-triangular-lattice compound Ba3CoSb2O9 that such
+interlayer coupling can induce an additional first-order transition at a strong
+field. We present the detailed CMF+S results for the magnetization and
+susceptibility curves of the fundamental Heisenberg Hamiltonian in the presence
+of magnetic field and weak antiferromagnetic interlayer coupling. The extra
+first-order transition appears as a quite small jump in the magnetization curve
+and a divergence in the susceptibility at a strong magnetic field ~ 0.712 of
+the saturation field.",1510.04402v1
+2017-07-24,"Magnetic properties of monoclinic lanthanide metaborates, $Ln$(BO$_2$)$_3$, $Ln$ = Pr, Nd, Gd, Tb","The bulk magnetic properties of the lanthanide metaborates, $Ln$(BO$_2$)$_3$,
+$Ln$ = Pr, Nd, Gd, Tb are studied using magnetic susceptibility, heat capacity
+and isothermal magnetisation measurements. They crystallise in a monoclinic
+structure containing chains of magnetic $Ln^{3+}$ and could therefore exhibit
+features of low-dimensional magnetism and frustration. Pr(BO$_2$)$_3$ is found
+to have a non-magnetic singlet ground state. No magnetic ordering is observed
+down to 0.4 K for Nd(BO$_2$)$_3$. Gd(BO$_2$)$_3$ exhibits a sharp magnetic
+transition at 1.1 K, corresponding to three-dimensional magnetic ordering.
+Tb(BO$_2$)$_3$ shows two magnetic ordering features at 1.05 K and 1.95 K. A
+magnetisation plateau at a third of the saturation magnetisation is seen at 2 K
+for both Nd(BO$_2$)$_3$ and Tb(BO$_2$)$_3$ which persists in an applied field
+of 14 T. This is proposed to be a signature of quasi one-dimensional behaviour
+in Nd(BO$_2$)$_3$ and Tb(BO$_2$)$_3$.",1707.07485v1
+2017-11-08,Magnetization measurements on as prepared and annealed Fe3-xMnxSi alloys,"The magnetic properties of the alloy system Fe3-xMnxSi have been studied by
+measuring magnetization for samples with x = 0, 0.1, 0.25, 0.5, and by thermal
+scanning techniques for samples with x = 0, 0.1. The results reveal that the
+system is ferromagnetic in this composition range. Zero field cooling and field
+cooling magnetization measurements indicate a similar magnetic ordering and
+magnetic anisotropy in all samples. The saturation magnetization for the
+annealed samples was higher than that for as prepared samples. This is
+attributed to the reduction of magnetic domain boundaries rather than to
+improving magnetic order as a result of annealing. Further, TC values
+determined from thermal DSC measurements are in good agreement with previously
+reported results based on magnetic measurements.",1711.03052v1
+2018-01-10,Quantum Theory of Rare-Earth Magnets,"Strong permanent magnets mainly consist of rare earths ($R$) and transition
+metals ($T$). The main phase of the neodymium magnet, which is the strongest
+magnet, is Nd$_2$Fe$_{14}$B. Sm$_{2}$Fe$_{17}$N$_{3}$ is another magnet
+compound having excellent magnetic properties comparable to those of
+Nd$_{2}$Fe$_{14}$B. Their large saturation magnetization, strong
+magnetocrystalline anisotropy, and high Curie temperature originate from the
+interaction between the $T$-3d electrons and $R$-4f electrons. This article
+discusses the magnetism of rare-earth magnet compounds. The basic theory and
+first-principles calculation approaches for quantitative description of the
+magnetic properties are presented, together with applications to typical
+compounds such as Nd$_2$Fe$_{14}$B, Sm$_{2}$Fe$_{17}$N$_{3}$, and the recently
+synthesized NdFe$_{12}$N.",1801.03455v1
+2020-07-21,Nonlinear turbulent dynamo during gravitational collapse,"Via amplification by turbulent dynamo, magnetic fields can be potentially
+important for the formation of the first stars. To examine the dynamo behavior
+during the gravitational collapse of primordial gas, we extend the theory of
+nonlinear turbulent dynamo to include the effect of gravitational compression.
+The relative importance between dynamo and compression varies during
+contraction, with the transition from dynamo- to compression-dominated
+amplification of magnetic fields with the increase of density. In the nonlinear
+stage of magnetic field amplification with the scale-by-scale energy
+equipartition between turbulence and magnetic fields, reconnection diffusion of
+magnetic fields in ideal magnetohydrodynamic (MHD) turbulence becomes
+important. It causes the violation of flux-freezing condition and accounts for
+(a) the small growth rate of nonlinear dynamo, (b) the weak dependence of
+magnetic energy on density during contraction, (c) the saturated magnetic
+energy, and (d) the large correlation length of magnetic fields. The resulting
+magnetic field structure and the scaling of magnetic field strength with
+density are radically different from the expectations of flux-freezing.",2007.11004v1
+2021-11-23,Controlling magnetic configuration in soft-hard bilayers probed by polarized neutron reflectometry,"Hard/soft magnetic bilayer thin films have been widely used in data storage
+technologies and permanent magnet applications. The magnetic configuration and
+response to temperatures and magnetic fields in these heterostructures are
+considered to be highly dependent on the interfacial coupling. However, the
+intrinsic properties of each of the layers, such as the saturation
+magnetization and layer thickness, also strongly influence the magnetic
+configuration. Changing these parameters provides an effective method to tailor
+magnetic properties in composite magnets. Here, we use polarized neutron
+reflectometry (PNR) to experimentally probe the interfacial magnetic
+configurations in hard/soft bilayer thin films: L10-FePt/A1-FePt, [Co/Pd]
+/CoPd, [Co/Pt] /FeNi and L10-FePt/Fe, which all have a perpendicular magnetic
+anisotropy in the hard layer. These films were designed with different soft and
+hard layer thicknesses (t_soft and t_hard) and saturation magnetization
+(M_s^soft and M_s^hard), respectively. The influences of an in-plane magnetic
+field (H_ip) and temperature (T) are also studied using a L10 FePt/A1-FePt
+bilayer sample. Comparing the PNR results to micromagnetic simulations reveals
+that the interfacial magnetic configuration is highly dependent on t_soft,
+M_s^soft and the external factors (H_ip and T), and has a relatively weak
+dependence on t_hard and M_s^hard. Key among these results, for thin t_soft,
+the hard and soft layers are rigidly coupled in the out-of-plane direction,
+then undergo a transition to relax in-plane. This transition can be delayed to
+larger t_soft by decreasing M_s^soft. Understanding the influence of these
+parameters on the magnetic configuration is critical to designing functional
+composite magnets for applications.",2111.12191v1
+1995-05-31,On the Existence of States Saturating the Bogomol'nyi Bound in N=4 Supersymmetry,"We give an argument showing that in N=4 supersymmetric gauge theories there
+exists at least one bound state saturating the Bogomol'nyi bound with electric
+charge $p$ and magnetic charge $q$, for each $p$ and $q$ relatively prime, and
+we comment on the uniqueness of such state. This result is a necessary
+condition for the existence of an exact S-duality in N=4 supersymmetric
+theories.",9505187v3
+1998-03-16,3-String Junction and BPS Saturated Solutions in SU(3) Supersymmetric Yang-Mills Theory,"We construct BPS saturated regular configurations of N=4 SU(3) supersymmetric
+Yang-Mills theory carrying non-parallel electric and magnetic charges. These
+field theory BPS states correspond to the string theory BPS states of 3-string
+junctions connecting three different D3-branes by regarding the N=4
+supersymmetric Yang-Mills theory as an effective field theory on parallel
+D3-branes.",9803127v2
+2005-01-26,Perturbative approach to the nonlinear saturation of the tearing mode for any current gradient,"Within the traditional frame of reduced MHD, a new rigorous perturbation
+expansion provides the equation ruling the nonlinear growth and saturation of
+the tearing mode for any current gradient. The small parameter is the magnetic
+island width w. For the first time, the final equation displays at once terms
+of order w ln(1/w) and w which have the same magnitude for practical purposes;
+two new O(w) terms involve the current gradient. The technique is applicable to
+the case of an external forcing. The solution for a static forcing is computed
+explicitly and it exhibits three physical regimes.",0501136v1
+2013-02-06,p-wave superconductivity near a transverse saturation field,"We investigate reentrant superconductivity in an Ising ferromagnetic
+superconductor URhGe under a transverse magnetic field h_x. The superconducting
+transition temperature for p-wave order parameters T_{sc} is calculated and
+shows two domes as a function of h_x. We find strong enhancement of T_{sc} in
+the high-field dome near a saturation field h_s where the spins align in the
+transverse direction. Soft magnons generate strong attractive interactions
+there. Spin components of the pairing show a significant change between h_x<h_s
+and h_x>h_s. We also discuss the appearance of superconductivity with zero-spin
+pair due to cancellation between external and exchange fields.",1302.1364v1
+2013-09-30,Free convection over a non-isothermal axisymmetric body immersed in a porous medium saturated with an electrically conducting non-Newtonian fluid,"The study investigates the problem of magnetohydrodynamic (MHD) free
+convection over a non-isothermal axisymmetric body under the action of
+transverse magnetic field. The body is embedded in a porous medium saturated
+with electrically conducting non-Newtonian power law fluid. In order to obtain
+similarity solution, it is assumed that the viscosity of the fluid decays
+exponentially with temperature. The qualitative results are illustrated for a
+vertical flat plate, horizontal cylinder and sphere.",1309.7864v1
+2013-12-09,Pseudofermion ferromagnetism in the Kondo lattices: a mean-field approach,"Ground state ferromagnetism of the Kondo lattices is investigated within
+slave fermion approach by Coleman and Andrei within a mean-field approximation
+in the effective hybridization model. Conditions for formation of both
+saturated (half-metallic) and non-saturated magnetic state are obtained for
+various lattices. A description in terms of universal functions which depend
+only on bare electron density of states (DOS) is presented. A crucial role of
+the energy dependence of the bare DOS (especially, of DOS peaks) for the
+small-moment ferromagnetism formation is demonstrated.",1312.2438v2
+2013-12-20,Energy Efficient Control of an Induction Machine under Load Torque Step Change,"Optimal control of magnetizing current for minimizing induction motor power
+losses during load torque step change was developed. Obtained strategy has
+feedback form and is exactly optimal of ideal speed controller performance and
+absence of saturation in motor. The impact of limited bandwidth of real speed
+controller is analyzed. For case of main induction saturation the sub-optimal
+optimal control is suggested. Relative accuracy of sub-optimality is studied.
+Hardware implementation of optimal strategy and experimentation conducted with
+induction motors under vector control.",1312.6094v2
+2015-11-30,An analysis of the benefits of signal injection for low-speed sensorless control of induction motors,"We analyze why low-speed sensorless control of the IM is intrinsically
+difficult, and what is gained by signal injection. The explanation relies on
+the control-theoretic concept of observability applied to a general model of
+the saturated IM. We show that the IM is not observable when the stator speed
+is zero in the absence of signal injection, but that observability is restored
+thanks to signal injection and magnetic saturation. The analysis also reveals
+that existing sensorless algorithms based on signal injection may perform
+poorly for some IMs under particular operating conditions. The approach is
+illustrated by simulations and experimental data.",1511.09349v1
+2022-08-08,Measurement of hyperfine constants and the isotope shift of rubidium 5P$_{1/2}$ excited-state using Saturated Absorption Spectroscopy,"The Saturated Absorption Spectroscopy (SAS) was performed to measure the
+hyperfine energy splittings of rubidium 5P$_{1/2}$ excited state using a
+homemade external-cavity diode laser (ECDL) operating at 795 nm. Any
+nonlinearities associated with ECDL scans were removed by using a low-expansion
+confocal Fabry-Perot cavity and hence created a linearized frequency axis for
+the spectra collected in a fully automated fashion. We report our measurements
+for the magnetic dipole coupling constants 120.79(29) and 407.75(50) for
+$^{85}Rb$ and $^{87}Rb$ respectively.",2208.04244v1
+2023-06-08,A Macroscopic Theory of Saturated Ferromagnetic Conductors,"A phenomenological theory of rigid and saturated ferromagnetic conductors is
+constructed from a four-continuum model consisting of a rigid lattice
+continuum, a bound charge continuum for polarization, a circulating current
+continuum for magnetization, and a free charge continuum for electrical
+conduction. The basic laws of physics are applied to the four continua. Thermal
+couplings and the related dissipative effects are also included. The theory
+includes the Landau-Lifshitz-Gilbert equation as one of a system of
+simultaneous equations.",2306.11525v1
+2023-07-31,A Continuum Theory of Elastic-Ferromagnetic Conductors,"In this paper, a phenomenological theory of saturated ferromagnetoelastic
+conductors is established using a multi-continuum model and the classical laws
+of mechanics, thermodynamics and electromagnetics. The theory is nonlinear and
+is valid for large deformations and strong electromagnetic fields. The
+constitutive relations in the theory satisfy the saturation condition of the
+magnetization vector. The theory is with full electromagnetic couplings as
+governed by the equations of electrodynamics. It can describe the interactions
+of elastic, electromagnetic and spin waves. The theory can be reduced to
+various quasistatic theories with appropriate approximations of the
+electromagnetic fields. It is for anisotropic materials in general.",2307.16669v1
+2023-10-10,The saturation of the Bell instability and its implications for cosmic ray acceleration and transport,"The non-resonant (Bell) streaming instability driven by energetic particles
+is crucial for producing amplified magnetic fields that are key to the
+acceleration of cosmic rays (CRs) in supernova remnants, around Galactic and
+extra-galactic CR sources, and for the CR transport. We present a covariant
+theory for the saturation of the Bell instability, substantiated by
+self-consistent kinetic simulations, that can be applied to arbitrary CR
+distributions and discuss its implications in several heliospheric and
+astrophysical contexts.",2310.07038v1
+2015-12-03,Saturation of the magnetorotational instability in the unstratified shearing box with zero net flux: convergence in taller boxes,"Previous studies of the nonlinear regime of the magnetorotational instability
+in one particular type of shearing box model -- unstratified with no net
+magnetic flux -- find that without explicit dissipation (viscosity and
+resistivity) the saturation amplitude decreases with increasing numerical
+resolution. We show that this result is strongly dependent on the vertical
+aspect ratio of the computational domain $L_z/L_x$. When $L_z/L_x\lesssim 1$,
+we recover previous results. However, when the vertical domain is extended
+$L_z/L_x \gtrsim 2.5$, we find the saturation level of the stress is greatly
+increased (giving a ratio of stress to pressure $\alpha \gtrsim 0.1$), and
+moreover the results are independent of numerical resolution. Consistent with
+previous results, we find that saturation of the MRI in this regime is
+controlled by a cyclic dynamo which generates patches of strong toroidal field
+that switches sign on scales of $L_x$ in the vertical direction. We speculate
+that when $L_z/L_x\lesssim 1$, the dynamo is inhibited by the small size of the
+vertical domain, leading to the puzzling dependence of saturation amplitude on
+resolution. We show that previous toy models developed to explain the MRI
+dynamo are consistent with our results, and that the cyclic pattern of toroidal
+fields observed in stratified shearing box simulations (leading to the
+so-called butterfly diagram) may also be related. In tall boxes the saturation
+amplitude is insensitive to whether or not explicit dissipation is included in
+the calculations, at least for large magnetic Reynolds and Prandtl number.
+Finally, we show MRI turbulence in tall domains has a smaller critical
+$\rm{Pm}_c$, and an extended lifetime compared to $L_z/L_x\lesssim 1$ boxes.",1512.01106v1
+2000-09-21,Mean Field Dynamo Saturation: Toward Understanding Conflicting Results,"Mean field dynamos may explain the origin of large scale magnetic fields of
+galaxies, but controversy arises over the extent of dynamo quenching by the
+growing field. Here we explain how apparently conflicting results may be
+mutually consistent, by showing the role of magnetic helicity conservation and
+boundary terms usually neglected. We estimate the associated magnetic energy
+flowing out of the Galaxy but emphasize that the mechanism of field escape
+needs to be addressed.",0009355v1
+2000-12-03,Synthesis of Small and Large scale Dynamos,"Using a closure model for the evolution of magnetic correlations, we uncover
+an interesting plausible saturated state of the small-scale fluctuation dynamo
+(SSD) and a novel anology between quantum mechanical tunneling and the
+generation of large-scale fields. Large scale fields develop via the
+$\alpha$-effect, but as magnetic helicity can only change on a resistive
+timescale, the time it takes to organize the field into large scales increases
+with magnetic Reynolds number. This is very similar to the results which obtain
+from simulations using full MHD.",0012053v1
+2005-12-23,Galactic dynamo and helicity losses through fountain flow,"Nonlinear behaviour of galactic dynamos is studied, allowing for magnetic
+helicity removal by the galactic fountain flow. A suitable advection speed is
+estimated, and a one-dimensional mean-field dynamo model with dynamic
+alpha-effect is explored. It is shown that the galactic fountain flow is
+efficient in removing magnetic helicity from galactic discs. This alleviates
+the constraint on the galactic mean-field dynamo resulting from magnetic
+helicity conservation and thereby allows the mean magnetic field to saturate at
+a strength comparable to equipartition with the turbulent kinetic energy.",0512592v2
+1997-12-05,Spin flip scattering in magnetic junctions,"Processes which flip the spin of an electron tunneling in a junction made up
+of magnetic electrodes are studied. It is found that: i) Magnetic impurities
+give a contribution which increases the resistance and lowers the
+magnetoresistance, which saturates at low temperatures. The conductance
+increases at high fields. ii) Magnon assisted tunneling reduces the
+magnetoresistance as $T^{3/2}$, and leads to a non ohmic contribution to the
+resistance which goes as $V^{3/2}$, iii) Surface antiferromagnetic magnons,
+which may appear if the interface has different magnetic properties from the
+bulk, gives rise to $T^2$ and $V^2$ contributions to the magnetoresistance and
+resistance, respectively, and, iv) Coulomb blockade effects may enhance the
+magnetoresistance, when transport is dominated by cotunneling processes.",9712075v1
+1998-03-02,Field induced transition of the S=1 antiferromagnetic chain with anisotropy,"The ground state magnetization process of the S=1 antiferromagnetic chain
+with the easy-axis single-ion anisotropy described by negative $D$ is
+investigated. It is numerically found that a phase transition between two
+different gapless phases occurs at an intermediate magnetic field between the
+starting and saturation points of the magnetization for $-1.49<D<-0.35$. The
+transition is similar to the spin flopping, but it is second-order and not
+accompanied with any significant anomalous behaviors in the magnetization
+curve. We also present the phase diagrams in the m-D and H-D planes which
+reveal a possible re-entrant transition.",9803022v2
+1998-04-15,Quantum Antiferromagnets in a Magnetic Field,"Motivated by recent experiments on low-dimensional quantum magnets in applied
+magnetic fields, we present a theoretical analysis of their properties based on
+the nonlinear sigma model. The spin stiffness and a 1/N expansion are used to
+map the regimes of spin-gap behavior, predominantly linear magnetization, and
+spin saturation. A two-parameter renormalization-group study gives the
+characteristic properties over the entire parameter range. The model is
+relevant to many systems exhibiting Haldane physics, and is applied here to the
+two-chain spin ladder compound CuHpCl.",9804151v1
+1999-05-15,Critical Behavior of Anisotropic Heisenberg Mixed-Spin Chains in a Field,"We numerically investigate the critical behavior of the spin-(1,1/2)
+Heisenberg ferrimagnet with anisotropic exchange coupling in a magnetic field.
+A quantized magnetization plateau as a function of the field, appearing at a
+third of the saturated magnetization, is stable over whole the
+antiferromagnetic coupling region. The plateau vanishes in the ferromagnetic
+coupling region via the Kosterlitz-Thouless transition. Comparing the quantum
+and classical magnetization curves, we elucidate what are essential quantum
+effects.",9905224v1
+1999-12-14,Magnetization Plateau in the Frustrated Spin Ladder,"The magnetization process of the S=1/2 antiferromagnetic spin ladder at T=0
+is studied by the exact diagonalization of finite clusters and size scaling
+analyses. It is found that a magnetization plateau appears at half the
+saturation value (m=1/2) in the presence of a sufficiently large
+next-nearest-neighbor exchange interaction to yield the frustration, when the
+rung coupling is larger than the leg one. The phase diagram at m=1/2 is given
+by the analysis based on the conformal invariance. The magnetization curves are
+also presented in several cases.",9912234v2
+2000-03-29,Enhanced Pinning of Vortices in Thin Film Superconductors by Magnetic Dot Arrays,"We study the pinning of vortices in thin film superconductors by magnetic
+dots in the London approximation. A single dot is in general able to pin
+multiple field-induced vortices, up to a saturation number n_s, which can be
+much larger than one. However, the magnetic field of the dot also creates
+intrinsic vortices and anti-vortices, which must be accounted for. In a
+ferromagnetic dot array, the intrinsic anti-vortices are pinned only
+interstitially. Much stronger pinning effect is expected of an
+antiferromagnetic dot array. Possible realizations of various magnetic
+configurations are discussed.",0003462v1
+2003-07-01,Magnetic Properties of Fe75Cu4Ni4Mo2B15 Alloy,"The structural and magnetic properties of ball-milled Fe75Cu4Ni4Mo2B15 alloy
+have been investigated through powder X-ray diffraction studies, magnetization
+and magnetoimpedance measurements. The particle size decreased rapidly with
+ball-milling up to 165 hours and then remained as a constant with further hours
+of milling while, the lattice expanded with milling time up to 165 hours and
+contracted back with further milling. Saturation magnetization is found to
+decrease rapidly up to 165 hours of milling and then started decreasing slowly
+with further milling time. Magnetoimpedance studies were carried out in pellets
+and thin films of Fe75Cu4Ni4Mo2B15. Magnetoimpedance in pellet is observed to
+be ~2.5% at 5Hz whereas, in thin films, it is observed to be ~1.5% at 3 MHz.",0307019v1
+2003-12-04,Ground states of quantum kagome antiferromagnets in a magnetic field,"We study the ground state properties of a quantum antiferromagnet in the
+kagome lattice in the presence of a magnetic field, paying particular attention
+to the stability of the plateau at magnetization 1/3 of saturation. While the
+plateau is reinforced by certain deformations of the lattice, like the
+introduction of structural defect lines and against an Ising anisotropy, ground
+state correlations are seen to be quite different and the undistorted SU(2)
+case appears to be rather special.",0312119v1
+2006-08-04,Effective Hamiltonians for some highly frustrated magnets,"In prior work, the authors developed a method of degenerate perturbation
+theory about the Ising limit to derive an effective Hamiltonian describing
+quantum fluctuations in a half-polarized magnetization plateau on the
+pyrochlore lattice. Here, we extend this formulation to an arbitrary lattice of
+corner sharing simplexes of $q$ sites, at a fraction $(q-2k)/q$ of the
+saturation magnetization, with $0<k<q$. We present explicit effective
+Hamiltonians for the examples of the checkerboard, kagome, and pyrochlore
+lattices. The consequent ground states in these cases for $k=1$ are also
+discussed.",0608131v1
+2006-09-28,Derivation of effective parameters of magnetic metamaterials composed of passive resonant LC inclusions,"We determine rigorously the effective permeability of magnetic metamaterials
+composed of passive particles exhibiting magnetic resonances. The effective
+permeability is expressed in terms of circuit parameters characteristic to
+these particles (L, C, and R) and particle geometry. The derivation takes into
+account the magnetic coupling between particles. We show that a bigger
+concentration of particles leads to an improvement in the metamaterial
+performances (such as bandwidth or loss tangent), but this effect saturates as
+the particles are packed more tightly. The theory is validated through
+numerical simulations of physically realizable metamaterials.",0609745v1
+2007-02-24,Quantum spin tunneling of magnetization in small ferromagnetic particles,"A new quantum approach is presented that can account for the description of
+small ferromagnetic particles magnetization tunneling. An estimate of the
+saturation value of an external applied magnetic field along the easy axis is
+obtained. An analytic expression for the tunneling factor in the absence of an
+external magnetic field is deduced from the present approach that also allows
+to obtain the crossover temperature characterizing the regime where tunneling
+is dominated by the quantum effects.",0702572v1
+2004-12-03,Numerical solutions of the three-dimensional magnetohydrodynamic alpha-model,"We present direct numerical simulations and alpha-model simulations of four
+familiar three-dimensional magnetohydrodynamic (MHD) turbulence effects:
+selective decay, dynamic alignment, inverse cascade of magnetic helicity, and
+the helical dynamo effect. The MHD alpha-model is shown to capture the
+long-wavelength spectra in all these problems, allowing for a significant
+reduction of computer time and memory at the same kinetic and magnetic Reynolds
+numbers. In the helical dynamo, not only does the alpha-model correctly
+reproduce the growth rate of magnetic energy during the kinematic regime, but
+it also captures the nonlinear saturation level and the late generation of a
+large scale magnetic field by the helical turbulence.",0412025v1
+2005-05-26,Low magnetic Prandtl number dynamos with helical forcing,"We present direct numerical simulations of dynamo action in a forced Roberts
+flow. The behavior of the dynamo is followed as the mechanical Reynolds number
+is increased, starting from the laminar case until a turbulent regime is
+reached. The critical magnetic Reynolds for dynamo action is found, and in the
+turbulent flow it is observed to be nearly independent on the magnetic Prandtl
+number in the range from 0.3 to 0.1. Also the dependence of this threshold with
+the amount of mechanical helicity in the flow is studied. For the different
+regimes found, the configuration of the magnetic and velocity fields in the
+saturated steady state are discussed.",0505192v1
+2007-04-27,Nonfrustrated magnetoelectric with incommensurate magnetic order in magnetic field,"We discuss a model nonfrustrated magnetoelectric in which strong enough
+magnetoelectric coupling produces incommensurate magnetic order leading to
+ferroelectricity. Properties of the magnetoelectric in magnetic field directed
+perpendicular to wave vector describing the spin helix are considered in
+detail. Analysis of classical energy shows that in contrast to naive
+expectation the onset of ferroelectricity takes place at a field $H_{c1}$ that
+is lower than the saturation field $H_{c2}$. One has $H_{c1}=H_{c2}$ at strong
+enough magnetoelectric coupling. We show that at H=0 the ferroelectricity
+appears at $T=T_{FE}<T_N$. Qualitative discussion of phase diagram in $H-T$
+plane is presented within mean field approach.",0704.3660v1
+2008-12-02,Magnetization Plateau of Classical Ising Model on Shastry-Sutherland Lattice,"We study the magnetization for the classical antiferromagnetic Ising model on
+the Shastry-Sutherland lattice using the tensor renormalization group approach.
+With this method, one can probe large spin systems with little finite-size
+effect. For a range of temperature and coupling constant, a single
+magnetization plateau at one third of the saturation value is found. We
+investigate the dependence of the plateau width on temperature and on the
+strength of magnetic frustration. Furthermore, the spin configuration of the
+plateau state at zero temperature is determined.",0812.0402v1
+2008-12-10,Effect of oxygen concentration on the structural and magnetic properties of LaRh1/2Mn1/2O3 thin films,"Epitaxial LaRh1/2Mn1/2O3 thin films have been grown on (001)-oriented LaAlO3
+and SrTiO3 substrates using pulsed laser deposition. The optimized thin film
+samples are semiconducting and ferromagnetic with a Curie temperature close to
+100 K, a coercive field of 1200 Oe, and a saturation magnetization of 1.7muB
+per formula unit. The surface texture, structural, electrical, and magnetic
+properties of the LaRh1/2Mn1/2O3 films was examined as a function of the oxygen
+concentration during deposition. While an elevated oxygen concentration yields
+thin films with optimal magnetic properties, slightly lower oxygen
+concentrations result in films with improved texture and crystallinity.",0812.1852v1
+2009-01-14,Interface coupling properties and reflection of bulk spin waves from biaxial multilayer ferromagnetic media,"The reflection coefficient of bulk spin waves from multilayer ferromagnetic
+structure with periodically modulated parameters of exchange interaction,
+uniaxial and rhombic magnetic anisotropy and saturation magnetization is
+calculated with a non-ideal coupling between layers. The strong dependence of
+spin-wave reflection coefficient on frequency, magnetic field and parameter of
+interfacial coupling is revealed. It allows changing the reflection intensity
+from 0 to 1 by changing either only external magnetic field value or frequency.
+The proposed model of boundary conditions gives the opportunity to take into
+account the quality of interfaces when studying the reflection processes of
+spin waves in multilayer structures.",0901.2012v1
+2010-11-10,Repair of magnetism in oxidized graphene nanoribbons,"Novel route for the establishing of magnetism in realistic oxidized graphene
+nanoribbons is proposed. Modelling of the migration of hydroxyl groups from
+central part to the zig-zag edges of graphene nanoribbons passivated by oxygen
+are performed with using density functional theory. The presence of hydroxyl
+groups near the edges leads formation of dangling bonds there instead saturated
+due to oxidation and repairs of magnetism diminished by edges oxidation. The
+route of manufacturing and stability of new type of magnetic graphene
+nanoribbons are also discussed.",1011.2342v1
+2011-03-23,Nonlinear Dynamics of Magnetic Islands Imbedded in Small-Scale Turbulence,"The nonlinear dynamics of magnetic tearing islands imbedded in a pressure
+gradient driven turbulence is investigated numerically in a reduced
+magnetohydrodynamic model. The study reveals regimes where the linear and
+nonlinear phases of the tearing instability are controlled by the properties of
+the pressure gradient. In these regimes, the interplay between the pressure and
+the magnetic flux determines the dynamics of the saturated state. A secondary
+instability can occur and strongly modify the magnetic island dynamics by
+triggering a poloidal rotation. It is shown that the complex nonlinear
+interaction between the islands and turbulence is nonlocal and involves small
+scales.",1103.4443v1
+2013-01-14,A complete theory for the magnetism of an ideal gas of electrons,"We have explored Pauli paramagnetism, Landau diamagnetism and de Haas-van
+Alphen effect in a single framework, and unified these three effects for all
+temperatures as well as for all strengths of magnetic field. Our result goes
+beyond Pauli-Landau result on the magnetism of the 3-D ideal gas of electrons,
+and is able to describe crossover of the de Haas-van Alphen oscillation to the
+saturation of magnetization. We also have obtained a novel asymptotic series
+expansion for the low temperature properties of the system.",1301.3025v2
+2013-05-13,Magnetic screening in high-energy heavy-ion collisions,"We show that classical chromomagnetic fields produced coherently in the
+initial stage of a heavy-ion collision exhibit screening. From the two-point
+field strength correlator we determine the magnetic mass for SU(2) to be m ~ 5
+times the saturation scale. Magnetic screening leads to an intuitive
+understanding of the area law scaling of spatial Wilson loops observed
+previously. The presence of screening effects in the initial state provides a
+basis for defining kinetic processes in the early stage of heavy-ion
+collisions, with electric and magnetic masses of the same order.",1305.2780v1
+2013-05-29,Magnetization Process and Adiabatic Demagnetization of the Antiferromagnetic Spin-1/2 Heisenberg Cubic Cluster,"A full energy spectrum of the spin-1/2 Heisenberg cubic cluster is used to
+investigate a low-temperature magnetization process and adiabatic
+demagnetization of this zero-dimensional 2x2x2 quantum spin system. It is shown
+that the antiferromagnetic spin-1/2 Heisenberg cube exhibits at low enough
+temperatures a stepwise magnetization curve with four intermediate plateaux at
+zero, one quarter, one half, and three quarters of the saturation
+magnetization. We have also found the enhanced magnetocaloric effect close to
+level-crossing fields that determine transitions between the intermediate
+plateaux.",1305.6704v1
+2013-07-03,Numerical study of magnetization plateaux in the spin-1/2 kagome Heisenberg antiferromagnet,"We clarify the existence of several magnetization plateaux for the kagome
+$S=1/2$ antiferromagnetic Heisenberg model in a magnetic field. Using
+approximate or exact localized magnon eigenstates, we are able to describe in a
+similar manner the plateau states that occur for magnetization per site
+$m=1/3$, $5/9$, and $7/9$ of the saturation value. These results are confirmed
+using large-scale Exact Diagonalization on lattices up to 63 sites.",1307.0975v2
+2013-07-24,Measurement of magnetization using domain compressibility in CoFeB films with perpendicular anisotropy,"We present a method to map the saturation magnetization of soft ultrathin
+films with perpendicular anisotropy, and we illustrate it to assess the
+compositional dependence of the magnetization of CoFeB(1 nm)/MgO films. The
+method relies on the measurement of the dipolar repulsion of parallel domain
+walls that define a linear domain. The film magnetization is linked to the
+field compressibility of the domain. The method also yields the minimal
+distance between two walls before their merging, which sets a practical limit
+to the storage density in spintronic devices using domain walls as storage
+entities.",1307.6479v1
+2013-08-06,Broadband ferromagnetic resonance characterization of GaMnAs thin films,"The precessional magnetization dynamics of GaMnAs thin films are
+characterized by broadband network analyzer ferromagnetic resonance (FMR) in a
+coplanar geometry at cryogenic temperatures. The FMR frequencies are
+characterized as function of in-plane field angle and field amplitude. Using an
+extended Kittel model of the FMR dispersion the magnetic film parameters such
+as saturation magnetization and anisotropies are derived. The modification of
+the FMR behavior and of the magnetic parameters of the thin film upon annealing
+is analyzed.",1308.1232v1
+2014-01-14,Defects induced ferromagnetism in plasma-enabled graphene nanopetals,"Ferromagnetism in graphene is fascinating, but it is still a big challenge
+for practical applications due to the weak magnetization. In order to enhance
+the magnetization, here, we design plasma-enabled graphene nanopetals with
+ultra-long defective edges of up to 105 m/g, ultra-dense lattice vacancies and
+hydrogen chemisorptions. The designed graphene nanopetals display robust
+ferromagnetism with large saturation magnetization of up to 2 emu/g at 5 K and
+1.2 emu/g at room temperatures. This work identifies the plasma-enabled
+graphene nanopetals as a promising candidate for graphene-based magnetic
+devices.",1401.3060v1
+2015-05-19,Magnetization Process of the Spin-S Kagome-Lattice Heisenberg Antiferromagnet,"The magnetization process of the spin-S Heisenberg antiferromagnet on the
+kagome lattice is studied by the numerical-diagonalization method. Our
+numerical-diagonalization data for small finite-size clusters with S=1, 3/2, 2,
+and 5/2 suggest that a magnetization plateau appears at one-third of the height
+of the saturation in the magnetization process irrespective of S. We discuss
+the S dependences of the edge fields and the width of the plateau in comparison
+with recent results obtained by real-space perturbation theory.",1505.04853v1
+2016-02-06,Lieb-Mattis ferrimagnetism in diluted magnetic semiconductors,"We show the possibility of long-range ferrimagnetic ordering with a
+saturation magnetisation of the order of 1 Bohr magneton per spin for
+arbitrarily low concentration of magnetic impurities in semiconductors,
+provided that the impurities form a superstructure satisfying the conditions of
+the Lieb-Mattis theorem. Explicit examples of such superstructures are given
+for the wurtzite lattice, and the temperature of ferrimagnetic transition is
+estimated from a high-temperature expansion. Exact diagonalization studies show
+that small fragments of the structure exhibit enhanced magnetic response and
+isotropic superparamagnetism at low temperatures. A quantum transition in a
+high magnetic field is considered and similar superstructures in cubic
+semiconductors are discussed as well.",1602.02239v1
+2017-06-30,Switching of Magnetic Moments of Nanoparticles by Surface Acoustic Waves,"We report evidence of the magnetization reversal in nanoparticles by surface
+acoustic waves (SAWs). The experimental system consists of isolated magnetite
+nanoparticles dispersed on a piezoelectric substrate. Magnetic relaxation from
+a saturated state becomes significantly enhanced in the presence of the SAW at
+a constant temperature of the substrate. The dependence of the relaxation on
+SAW power and frequency has been investigated. The effect is explained by the
+effective ac magnetic field generated by the SAW in the nanoparticles.",1707.00045v1
+2017-07-11,Nature of Magnetoelectric coupling in corundum antiferromagnet Co4Ta2O9,"We study the magnetocapacitance (MC) effect and magnetoelectric (ME) coupling
+in spin-flop driven antiferromagnet Co4Ta2O9. The magnetocapacitance data at
+high magnetic fields are analyzed by phenomenological Ginzburg-landau theory of
+ferroelectromagnets and it is found that change in dielectric constant is
+proportional to the square of magnetization. The saturation polarization and
+magnetoelectric coupling are estimated to be 52microC/m2 and $\gamma$ = 1.4
+x10-3 (emu/g)-2 respectively at 6 Tesla. Electric polarization is achieved
+below Neel temperature only when the sample is cooled in the presence of
+magnetic field and it is established that the ground state is non-ferroelectric
+implying that magnetic lattice does not lead to spontaneous symmetry breaking
+in Co4Ta2O9.",1707.03127v1
+2017-07-23,Tuning the Magnetic Properties of M-type Hexaferrites,"In this article, common experimental techniques and preparation conditions
+adopted for the synthesis of M-type hexaferrites and their influence on the
+magnetic properties are briefly reviewed. The effects of various strategies of
+cationic substitutions on the properties of the hexaferrites are addressed.
+Further, our synthesis and findings on Co-Ti substituted hexaferrites are
+presented. It was found that Co-Ti substitution results in improving the
+saturation magnetization, and reducing the coercivity down to values favorable
+for high density magnetic recording. Also, evidence of inter-particle
+interactions in the particulate samples was observed.",1707.07243v1
+2018-06-21,"Magnetic Properties of Lithium-Containing Rare Earth Garnets Li3RE3Te2O12 (RE = Y, Pr, Nd, Sm-Lu)","The synthesis, structural description, temperature dependent magnetic
+susceptibilities and field dependent magnetizations of a series of rare earth
+garnets of the form Li3RE3Te2O12 (RE = Y, La, Pr, Nd, Sm-Lu) are reported. The
+structure of Li3Dy3Te2O12 is refined from powder X-ray diffraction data. The
+field dependent magnetizations saturate for some of the members by 9 Tesla at 2
+K. Of particular interest for further study in this family is the behavior of
+the Pr, Tb, Dy and Yb garnets.",1806.08399v1
+2018-07-24,Pushing the limits of magnetic anisotropy in the Sm-Co system,"Materials based on the Sm-Co system exhibit remarkable magnetic performance
+due to their high Curie temperature, large saturation magnetization, and strong
+magnetic anisotropy, which are the result of the electronic structure in Co and
+Sm and their arrangement in the hexagonal lattice. In this paper we show, using
+first-principles calculations, mean-field theory, and atomistic Monte Carlo
+simulations that slight modifications of the SmCo5 crystal structure, induced
+by strain or partial substitution of Sm by Ce, change the exchange interaction
+energy and increase the magnetocrystalline anisotropy energy drastically. This
+finding shows how small changes in local-structure environments lead to
+substantial changes in macroscopic properties and enables the optimization of
+high-performance materials at the atomic level.",1807.09257v1
+2020-01-18,Synthesis of Fe$_3$O$_4$ nanoparticles and their magnetic properties,"Fe$_3$O$_4$ magnetic nanoparticles (MNPs) were synthesized by a
+co-precipitation method using sodium citrate and oleic acid as modifiers. Phase
+composition and microstructure analysis indicate that the sodium citrate and
+oleic acid have been successfully grafted onto the surface of Fe$_3$O$_4$ MNPs.
+The magnetic behaviors reveal that the modification can decrease the saturation
+magnetization of Fe$_3$O$_4$ MNPs due to the surface effect. Fe$_3$O$_4$ MNPs
+modified by sodiumcitrate and oleic acid show excellent dispersion capability,
+which should be ascribed to the great reduction of high surface energy and
+dipolar attraction of the nanoparticles.",2001.06583v1
+2020-03-28,Magnon binding in BaCdVO(PO$_4$)$_2$,"The bond-nematic state has both long-range ordering of magnetic quadrupoles
+and the high entanglement typical of spin liquids, and as such can be thought
+of as a spin liquid crystal. One of the most promising materials in which to
+find such a state is BaCdVO(PO$_4$)$_2$, in which a magnetically silent phase
+has been found between a magnetically ordered low-field phase and the
+high-field polarised phase. Here I study the magnetic Hamiltonian of
+BaCdVO(PO$_4$)$_2$, and, for the Hamiltonian-parameters determined by fits to
+inelastic neutron scattering experiments, show that magnons condense out of the
+polarised state as bound pairs. This is direct theoretical support for the
+existence of a bond-nematic state just below the saturation field.",2003.12747v1
+2023-07-25,Effect of resonance magnetic perturbation on edge-core turbulence spreading in a tokamak plasma,"Turbulence spreading from edge to core region with resonance magnetic
+perturbation (RMP) is investigated using an electromagnetic Landau-fluid model
+in toroidal geometry. When RMP field with appropriate amplitude are employed in
+the simulation, long wavelength fluctuations around the resonance surface are
+excited due to the forced magnetic reconnection. Strong shear flow at the
+magnetic island separatrix are observed, and break the radial elongated vortex
+structures of the turbulent fluctuation. The inward flux could be blocked by
+this shear flow and the saturation level in the core region declines.",2307.13351v1
+2023-11-28,Origin of the classical magnetization discontinuities of the dodecahedron,"The classical antiferromagnetic Heisenberg model on the dodecahedron has been
+shown to have three magnetization discontinuities in an external field. Here it
+is shown that the highest-field discontinuity can be directly traced back to
+the strong magnetization jump leading to saturation at the Ising limit, which
+originates from the frustrated connectivity of the molecule. This discontinuity
+survives up to the $XY$ limit and disappears just before the ferromagnetic
+Ising interaction fully polarizes the spins. The two lower-field jumps of the
+model result from the competition of discontinuities that emerge from the
+magnetization plateau surviving away from the Ising limit.",2311.17205v1
+2024-01-31,Impurity effects in one dimensional spin nematic liquid,"We study impurity effects in the spin nematic phase of the $S=1/2$
+$J_1$-$J_2$ frustrated spin chain under an external magnetic field by using the
+infinite density matrix renormalization group and the bosonization. It is found
+that local magnetization almost saturates around the impurity and the
+entanglement entropy nearly vanishes at the corresponding bonds, not only when
+the magnetic interactions near the impurity are weakened but also when they are
+strengthened compared to those in the bulk. Then, we examine spin correlations
+and Friedel oscillations induced by the impurity. The bosonization provides a
+qualitative understanding of the characteristic behaviors of the magnetization.
+We also discuss impacts of the impurity on experiments by focusing on NMR
+spectra.",2401.17552v1
+2022-06-02,A new scenario for magnetar formation: Tayler-Spruit dynamo in a proto-neutron star spun up by fallback,"Magnetars are isolated young neutron stars characterized by the most intense
+magnetic fields known in the universe. The origin of their magnetic field is
+still a challenging question. In situ magnetic field amplification by dynamo
+action is a promising process to generate ultra-strong magnetic fields in
+fast-rotating progenitors. However, it is unclear whether the fraction of
+progenitors harboring fast core rotation is sufficient to explain the entire
+magnetar population. To address this point, we propose a new scenario for
+magnetar formation, in which a slow-rotating proto-neutron star is spun up by
+the supernova fallback. We argue that this can trigger the development of the
+Tayler-Spruit dynamo while other dynamo processes are disfavored. Using
+previous works done on this dynamo and simulations to characterize the
+fallback, we derive equations modelling the coupled evolution of the
+proto-neutron star rotation and magnetic field. Their time integration for
+different fallback masses is successfully compared with analytical estimates of
+the amplification timescales and saturation value of the magnetic field. We
+find that the magnetic field is amplified within $20$ to $40$s after the core
+bounce, and that the radial magnetic field saturates at intensities
+$10^{14}-10^{15}$G, therefore spanning the full range of magnetar's dipolar
+magnetic fields. We also compare predictions of two proposed saturation
+mechanisms showing that magnetar-like magnetic fields can be generated for
+neutron star spun up to rotation periods $\lesssim8$ms and $\lesssim28$ms,
+corresponding to fallback masses $\gtrsim4\times10^{-2}{\rm M}_{\odot}$ and
+$\gtrsim10^{-2}{\rm M}_{\odot}$. Thus, our results suggest that magnetars can
+be formed from slow-rotating progenitors for fallback masses compatible with
+recent supernova simulations and leading to plausible initial rotation periods
+of the proto-neutron star.",2206.01269v2
+2009-09-11,Saturation and time dependence of geodynamo models,"In this study we address the question under which conditions a saturated
+velocity field stemming from geodynamo simulations leads to an exponential
+growth of the magnetic field in a corresponding kinematic calculation. We
+perform global self-consistent geodynamo simulations and calculate the
+evolution of a kinematically advanced tracer field. The self-consistent
+velocity field enters the induction equation in each time step, but the tracer
+field does not contribute to the Lorentz force. This experiment has been
+performed by Cattaneo & Tobias (2009) and is closely related to the test field
+method by Schrinner et al. (2005, 2007). We find two dynamo regimes in which
+the tracer field either grows exponentially or approaches a state aligned with
+the actual self-consistent magnetic field after an initial transition period.
+Both regimes can be distinguished by the Rossby number and coincide with the
+dipolar and multipolar dynamo regimes identified by Christensen & Aubert
+(2006). Dipolar dynamos with low Rossby number are kinematically stable whereas
+the tracer field grows exponentially in the multipolar dynamo regime. This
+difference in the saturation process for dynamos in both regimes comes along
+with differences in their time variability. Within our sample of 20 models,
+solely kinematically unstable dynamos show dipole reversals and large
+excursions. The complicated time behaviour of these dynamos presumably relates
+to the alternating growth of several competing dynamo modes. On the other hand,
+dynamos in the low Rossby number regime exhibit a rather simple time dependence
+and their saturation merely results in a fluctuation of the fundamental dynamo
+mode about its critical state.",0909.2181v1
+2021-10-14,Superconductor-insulator transitions in three-dimensional indium-oxide at high pressures,"Experiments investigating magnetic-field-tuned superconductor-insulator
+transition (HSIT) mostly focus on two-dimensional material systems where the
+transition and its proximate ground-state phases, often exhibit features that
+are seemingly at odds with the expected behavior. Here we present a
+complementary study of a three-dimensional pressure-packed amorphous
+indium-oxide (InOx) powder where granularity controls the HSIT. Above a low
+threshold pressure of ~0.2 GPa, vestiges of superconductivity are detected,
+although neither a true superconducting transition nor insulating behavior are
+observed. Instead, a saturation at very high resistivity at low pressure is
+followed by saturation at very low resistivity at higher pressure. We identify
+both as different manifestations of anomalous metallic phases dominated by
+superconducting fluctuations. By analogy with previous identification of the
+low resistance saturation as a ""failed superconductor"", our data suggests that
+the very high resistance saturation is a manifestation of a ""failed insulator"".
+Above a threshold pressure of ~6 GPa, the sample becomes fully packed, and
+superconductivity is robust, with TC tunable with pressure. A quantum critical
+point at PC~25 GPa marks the complete suppression of superconductivity. For a
+finite pressure below PC, a magnetic field is shown to induce a HSIT from a
+true zero-resistance superconducting state to a weakly insulating behavior.
+Determining the critical field, HC, we show that similar to the 2D behavior,
+the insulating-like state maintains a superconducting character, which is
+quenched at higher field, above which the magnetoresistance decreases to its
+fermionic normal state value.",2110.07251v3
+2022-06-28,Turbulent magnetic helicity fluxes in solar convective zone,"Combined action of helical motions of plasma (the $\alpha$ effect) and
+non-uniform (differential) rotation is a key dynamo mechanism of solar and
+galactic large-scale magnetic fields. Dynamics of magnetic helicity of
+small-scale fields is a crucial mechanism in a nonlinear dynamo saturation
+where turbulent magnetic helicity fluxes allow to avoid catastrophic quenching
+of the $\alpha$ effect. The convective zone of the Sun and solar-like stars as
+well as galactic discs are the source for production of turbulent magnetic
+helicity fluxes. In the framework of the mean-field approach and the spectral
+$\tau$ approximation, we derive turbulent magnetic helicity fluxes using the
+Coulomb gauge in a density-stratified turbulence. The turbulent magnetic
+helicity fluxes include non-gradient and gradient contributions. The
+non-gradient magnetic helicity flux is proportional to a nonlinear effective
+velocity (which vanishes in the absence of the density stratification)
+multiplied by small-scale magnetic helicity, while the gradient contributions
+describe turbulent magnetic diffusion of the small-scale magnetic helicity. In
+addition, the turbulent magnetic helicity fluxes contain source terms
+proportional to the kinetic $\alpha$ effect or its gradients, and also
+contributions caused by the large-scale shear (solar differential rotation). We
+have demonstrated that the turbulent magnetic helicity fluxes due to the
+kinetic $\alpha$ effect and its radial derivative in combination with the
+nonlinear magnetic diffusion of the small-scale magnetic helicity are dominant
+in the solar convective zone.",2206.14152v2
+2015-11-18,"Minimalist coupled evolution model for stellar x-ray activity, rotation, mass loss, and magnetic field","Late-type main sequence stars exhibit an x-ray to bolometric flux ratio that
+depends on ${\tilde Ro}$, the ratio of rotation period to convective turnover
+time, as ${\tilde Ro}^{-\zeta}$ with $2\le \zeta \le 3$ for ${\tilde Ro}
+>0.13$, but saturates with $|\zeta| <0.2$ for ${\tilde Ro} < 0.13$. Saturated
+stars are younger than unsaturated stars and show a broader spread of rotation
+rates and x-ray activity. The unsaturated stars have magnetic fields and
+rotation speeds that scale roughly with the square root of their age, though
+possibly flattening for stars older than the sun. The connection between faster
+rotators, stronger fields, and higher activity has been established
+observationally, but a theory for the unified time-evolution of x-ray
+luminosity, rotation, magnetic field and mass loss that captures the above
+trends has been lacking. Here we derive a minimalist holistic framework for the
+time evolution of these quantities built from combining a Parker wind with new
+ingredients: (1) explicit sourcing of both the thermal energy launching the
+wind and the x-ray luminosity via dynamo produced magnetic fields; (2) explicit
+coupling of x-ray activity and mass loss saturation to dynamo saturation (via
+magnetic helicity build-up and convection eddy shredding); (3) use of coronal
+equilibrium to determine how magnetic energy is divided into wind and x-ray
+contributions. For solar-type stars younger than the sun, we infer conduction
+to be a subdominant power loss compared to x-rays and wind. For older stars,
+conduction is more important, possibly quenching the wind and reducing angular
+momentum loss. We focus on the time evolution for stars younger than the sun,
+highlighting what is possible for further generalizations. Overall, the
+approach shows promise toward a unified explanation of all of the
+aforementioned observational trends.",1511.05658v4
+1995-10-23,The MHD Kelvin-Helmholtz Instability: A Two-Dimensional Numerical Study,"Using a new numerical code we have carried out two-dimensional simulations of
+the nonlinear evolution of unstable sheared magnetohydrodynamic flows. We
+considered two cases: a strong magnetic field (Alfven Mach number, M_a = 2.5)
+and a weak field (M_a =5). Each flow rapidly evolves until it reaches a nearly
+steady condition, which is fundamentally different from the analogous
+gasdynamic state. Both MHD flows relax to a stable, laminar flow on timescales
+less than or of the order of 15 linear growth times, measured from saturation
+of the instability. That timescale is several orders of magnitude less than the
+nominal dissipation time for these simulated flows, so this condition
+represents an quasi-steady relaxed state. The strong magnetic field case
+reaches saturation as magnetic tension in the displaced flow boundary becomes
+sufficient to stabilize it. That flow then relaxes in a straightforward way to
+the steady, laminar flow condition. The weak magnetic field case, on the other
+hand, begins development of the vortex expected for gasdynamics, but that
+vortex is destroyed by magnetic stresses that locally become strong. Magnetic
+topologies lead to reconnection and dynamical alignment between magnetic and
+velocity fields. Together these processes produce a sequence of intermittent
+vortices and subsequent relaxation to a nearly laminar flow condition in which
+the magnetic cross helicity is nearly maximized. Remaining irregularities
+consist of a pair of flux tubes straddling the shear layer. Fluctuations within
+those features are closely aligned, representing Alfv\'en waves propagating
+locally downstream.",9510115v1
+2005-05-25,Magnetic turbulence in cool cores of galaxy clusters,"We argue that the recently reported Kolmogorov-like magnetic turbulence
+spectrum in the cool core of the Hydra A galaxy cluster can be understood by
+kinetic energy injection by active galaxies that drives a turbulent non-helical
+magnetic dynamo into its saturated state. Although dramatic differences exist
+between small-scale dynamo scenarios, their saturated state is expected to be
+similar, as we show for three scenarios: the flux rope dynamo, the fluctuation
+dynamo, and the explosive dynamo. Based on those scenarios, we develop an
+analytical model of the hydrodynamic and magnetic turbulence in cool cores. The
+model implies magnetic field strengths that fit well with Faraday rotation
+measurements and minimum energy estimates for the sample of cool core clusters
+having such data available. Predictions for magnetic fields in clusters for
+which the appropriate observational information is still missing, and for yet
+unobserved quantities like the hydrodynamical turbulence velocity and
+characteristic length-scale are provided. The underlying dynamo models suggest
+magnetic intermittency and possibly a large-scale hydrodynamic viscosity. We
+conclude that the success of the model to explain the field strength in cool
+core clusters indicates that in general cluster magnetic fields directly
+reflect hydrodynamical turbulence, also in clusters without cool cores.",0505517v3
+1999-10-21,A Spin-1/2 Model for CsCuCl_3 in an External Magnetic Field,"CsCuCl_3 is a ferromagnetically stacked triangular spin-1/2 antiferromagnet.
+We discuss models for its zero-temperature magnetization process. The models
+range from three antiferromagnetically coupled ferromagnetic chains to the full
+three-dimensional situation. The situation with spin-1/2 is treated by
+expansions around the Ising limit and exact diagonalization. Further,
+weak-coupling perturbation theory is used mainly for three coupled chains which
+are also investigated numerically using the density-matrix renormalization
+group technique. We find that already the three-chain model gives rise to the
+plateau-like feature at one third of the saturation magnetization which is
+observed in magnetization experiments on CsCuCl_3 for a magnetic field
+perpendicular to the crystal axis. For a magnetic field parallel to the crystal
+axis, a jump is observed in the experimental magnetization curve in the region
+of again about one third of the saturation magnetization. In contrast to
+earlier spinwave computations, we do not find any evidence for such a jump with
+the model in the appropriate parameter region.",9910318v2
+2008-08-03,Metamagnetic transition in EuFe$_2$As$_2$ single crystals,"We report the measurements of anisotropic magnetization and magnetoresistance
+on single crystals of EuFe$_2$As$_2$, a parent compound of ferro-arsenide
+high-temperature superconductor. Apart from the antiferromagnetic (AFM)
+spin-density-wave transition at 186 K associated with Fe moments, the compound
+undergoes another magnetic phase transition at 19 K due to AFM ordering of
+Eu$^{2+}$ spins ($J=S=7/2$). The latter AFM state exhibits metamagnetic
+transition under magnetic fields. Upon applying magnetic field with $H\parallel
+c$ at 2 K, the magnetization increases linearly to 7.0 $\mu_{B}$/f.u. at
+$\mu_{0}H$=1.7 T, then keeps at this value of saturated Eu$^{2+}$ moments under
+higher fields. In the case of $H\parallel ab$, the magnetization increases
+step-like to 6.6 $\mu_{B}$/f.u. with small magnetic hysteresis. A metamagnetic
+phase was identified with the saturated moments of 4.4 $\mu_{B}$/f.u. The
+metamagnetic transition accompanies with negative in-plane magnetoresistance,
+reflecting the influence of Eu$^{2+}$ moments ordering on the electrical
+conduction of FeAs layers. The results were explained in terms of
+spin-reorientation and spin-reversal based on an $A$-type AFM structure for
+Eu$^{2+}$ spins. The magnetic phase diagram has been established.",0808.0325v2
+2010-10-19,Numerical Simulations of Dynamos Generated in Spherical Couette Flows,"We numerically investigate the efficiency of a spherical Couette flow at
+generating a self-sustained magnetic field. No dynamo action occurs for
+axisymmetric flow while we always found a dynamo when non-axisymmetric
+hydrodynamical instabilities are excited. Without rotation of the outer sphere,
+typical critical magnetic Reynolds numbers $Rm_c$ are of the order of a few
+thousands. They increase as the mechanical forcing imposed by the inner core on
+the flow increases (Reynolds number $Re$). Namely, no dynamo is found if the
+magnetic Prandtl number $Pm=Rm/Re$ is less than a critical value $Pm_c\sim 1$.
+Oscillating quadrupolar dynamos are present in the vicinity of the dynamo
+onset. Saturated magnetic fields obtained in supercritical regimes (either
+$Re>2 Re_c$ or $Pm>2Pm_c$) correspond to the equipartition between magnetic and
+kinetic energies. A global rotation of the system (Ekman numbers $E=10^{-3},
+10^{-4}$) yields to a slight decrease (factor 2) of the critical magnetic
+Prandtl number, but we find a peculiar regime where dynamo action may be
+obtained for relatively low magnetic Reynolds numbers ($Rm_c\sim 300$). In this
+dynamical regime (Rossby number $Ro\sim -1$, spheres in opposite direction) at
+a moderate Ekman number ($E=10^{-3}$), a enhanced shear layer around the inner
+core might explain the decrease of the dynamo threshold. For lower $E$
+($E=10^{-4}$) this internal shear layer becomes unstable, leading to small
+scales fluctuations, and the favorable dynamo regime is lost. We also model the
+effect of ferromagnetic boundary conditions. Their presence have only a small
+impact on the dynamo onset but clearly enhance the saturated magnetic field in
+the ferromagnetic parts. Implications for experimental studies are discussed.",1010.3859v2
+2012-02-15,Origin of strong magnetic fields in Milky-Way like galactic haloes,"An analytical model predicting the growth rates, the absolute growth times
+and the saturation values of the magnetic field strength within galactic haloes
+is presented. The analytical results are compared to cosmological MHD
+simulations of Milky-Way like galactic halo formation performed with the N-body
+/ \textsc{Spmhd} code \textsc{Gadget}. The halo has a mass of
+$\approx{}3\cdot{}10^{12}$ $M_{\odot}$ and a virial radius of $\approx{}$270
+kpc. The simulations in a $\Lambda$CDM cosmology also include radiative
+cooling, star formation, supernova feedback and the description of non-ideal
+MHD. A primordial magnetic seed field ranging from $10^{-10}$ to $10^{-34}$ G
+in strength agglomerates together with the gas within filaments and
+protohaloes. There, it is amplified within a couple of hundred million years up
+to equipartition with the corresponding turbulent energy. The magnetic field
+strength increases by turbulent small-scale dynamo action. The turbulence is
+generated by the gravitational collapse and by supernova feedback.
+Subsequently, a series of halo mergers leads to shock waves and amplification
+processes magnetizing the surrounding gas within a few billion years. At first,
+the magnetic energy grows on small scales and then self-organizes to larger
+scales. Magnetic field strengths of $\approx{}10^{-6}$ G are reached in the
+center of the halo and drop to $\approx{}10^{-9}$ G in the IGM. Analyzing the
+saturation levels and growth rates, the model is able to describe the process
+of magnetic amplification notably well and confirms the results of the
+simulations.",1202.3349v1
+2013-10-11,Trace element content and magnetic properties of commercial HOPG samples studied by ion beam microscopy and SQUID magnetometry,"In this study, the impurity concentration and magnetic response of nine
+highly oriented pyrolytic graphite (HOPG) samples with different grades and
+from different providers were determined using ion beam microscopy and SQUID
+magnetometry. Apart from sideface contaminations in the as-received state, bulk
+contamination of the samples in most cases consists of disk-shaped micron-sized
+particles made of Ti and V with an additional Fe contamination around the grain
+perimeter. The saturation magnetization typically increases with Fe
+concentration, however, there is no simple correlation between Fe content and
+magnetic moment. The saturation magnetization of one, respectively six, out of
+nine samples clearly exceeds the maximum contribution from pure Fe or Fe3C. For
+most samples the temperature dependence of the remanence decreases linearly
+with T - a dependence found previously for defect-induced magnetism (DIM) in
+HOPG. We conclude that apart from magnetic impurities, additional contribution
+to the ferromagnetic magnetization exists in pristine HOPG in agreement with
+previous studies. A comparative study between the results of ion beam
+microscopy and the commonly used EDX analysis shows clearly that EDX is not a
+reliable method for quantitative trace elemental analysis in graphite,
+clarifying weaknesses and discrepancies in the element concentrations given in
+the recent literature.",1310.3056v2
+2014-02-05,Fieldlike and antidamping spin-orbit torques in as-grown and annealed Ta/CoFeB/MgO layers,"We present a comprehensive study of the current-induced spin-orbit torques in
+perpendicularly magnetized Ta/CoFeB/MgO layers. The samples were annealed in
+steps up to 300 degrees C and characterized using x-ray absorption
+spectroscopy, transmission electron microscopy, resistivity, and Hall effect
+measurements. By performing adiabatic harmonic Hall voltage measurements, we
+show that the transverse (field-like) and longitudinal (antidamping-like)
+spin-orbit torques are composed of constant and magnetization-dependent
+contributions, both of which vary strongly with annealing. Such variations
+correlate with changes of the saturation magnetization and magnetic anisotropy
+and are assigned to chemical and structural modifications of the layers. The
+relative variation of the constant and anisotropic torque terms as a function
+of annealing temperature is opposite for the field-like and antidamping
+torques. Measurements of the switching probability using sub-{\mu}s current
+pulses show that the critical current increases with the magnetic anisotropy of
+the layers, whereas the switching efficiency, measured as the ratio of magnetic
+anisotropy energy and pulse energy, decreases. The optimal annealing
+temperature to achieve maximum magnetic anisotropy, saturation magnetization,
+and switching efficiency is determined to be between 240 degrees and 270
+degrees C.",1402.0986v2
+2015-11-11,A global galactic dynamo with a corona constrained by relative helicity,"We present a model for a global axisymmetric turbulent dynamo operating in a
+galaxy with a corona which treats the supernovae (SNe) and magneto-rotational
+instability (MRI) driven turbulence parameters under a common formalism. The
+nonlinear quenching of the dynamo is alleviated by inclusion of small-scale
+advective and diffusive magnetic helicity fluxes, which allow the gauge
+invariant magnetic helicity to be transferred outside the disk and consequently
+build up a corona during the course of dynamo action. The time-dependent dynamo
+equations are expressed in a separable form and solved through an eigenvector
+expansion constructed using the steady-state solutions of the dynamo equation.
+The parametric evolution of the dynamo solution allows us to estimate the final
+structure of the global magnetic field and the saturated value of the
+turbulence parameter $\alpha_m$, even before solving the dynamical equations
+for evolution of magnetic fields in the disk and the corona, along with
+$\alpha$-quenching. We then solve these equations simultaneously to study the
+saturation of large-scale magnetic field, its dependence on the small-scale
+magnetic helicity fluxes and corresponding evolution of the force-free field in
+the corona. The quadrupolar large-scale magnetic field in the disk is found to
+reach equipartition strength within a timescale of 1 Gyr. The large-scale
+magnetic field in the corona obtained is much weaker in strength compared to
+the field inside the disk and has only a weak impact on the dynamo operation.",1511.03392v2
+2017-12-17,"Low temperature ferromagnetic properties, magnetic field induced spin order and random spin freezing effect in Ni1.5Fe1.5O4 ferrite; prepared at different pH values and annealing temperatures","We present the low temperature magnetic properties in Ni1.5Fe1.5O4 ferrite as
+the function of pH at which the material was prepared by chemical route and
+post annealing temperature. The material is a ferri or ferromagnet, but showed
+magnetic blocking and random spin freezing process on lowering the measurement
+temperature down to 5 K. The sample prepared at pH =12 and annealed at 800 ^C
+showed a sharp magnetization peak at 105 K, the superparamagnetic blocking
+temperature of the particles. The magnetization peak remained incomplete within
+measurement temperature up to 350 K for rest of the samples, although peak
+temperature was brought down by increasing applied dc field. The fitting of
+temperature dependence of coercivity data according to Kneller law suggested
+random orientation of ferromagnetic particles. The fitting of saturation
+magnetization according to Bloch law provided the exponent that largely
+deviated from 1.5, a typical value for long ranged ferromagnet. An abrupt
+increase of saturation magnetization below 50 K suggested the active role of
+frozen surface spins in low temperature magnetic properties. AC susceptibility
+data elucidated the low temperature spin freezing dynamics and exhibited the
+characters of cluster spin glass in the samples depending on pH value and
+annealing temperature.",1712.06114v1
+2019-09-16,Magnetic ground state of the frustrated spin-1/2 chain compound $β$-TeVO$_4$ at high magnetic fields,"Frustrated spin-1/2 chains, despite the apparent simplicity, exhibit
+remarkably rich phase diagram comprising vector-chiral (VC), spin-density-wave
+(SDW) and multipolar/spin-nematic phases as a function of the magnetic field.
+Here we report a study of $\beta$-TeVO$_4$, an archetype of such compounds,
+based on magnetization and neutron diffraction measurements up to 25 T. We find
+the transition from the helical VC ground state to the SDW state at $\sim$3 T
+for the magnetic field along the $a$ and $c$ crystal axes, and at $\sim$9 T for
+the field along the $b$ axis. The high-field (HF) state, existing above
+$\sim$18 T, i.e., above $\sim$1/2 of the saturated magnetization, is an
+incommensurate magnetically ordered state and not the spin-nematic state, as
+theoretically predicted for the isotropic frustrated spin-1/2 chain. The HF
+state is likely driven by sizable interchain interactions and symmetric
+intrachain anisotropies uncovered in previous studies. Consequently, the
+potential existence of the spin nematic phase in $\beta$-TeVO$_4$ is limited to
+a narrow field range, i.e., a few tenths of a tesla bellow the saturation of
+the magnetization, as also found in other frustrated spin-1/2 chain compounds.",1909.07085v1
+2020-10-06,Insights into nature of magnetization plateaus of a nickel complex [Ni4(CO3)2(aetpy)8](ClO4)4 from a spin-1 Heisenberg diamond cluster,"Magnetic and magnetocaloric properties of a spin-1 Heisenberg diamond cluster
+with two different coupling constants are investigated with the help of an
+exact diagonalization based on the Kambe's method, which employs a local
+conservation of composite spins formed by spin-1 entities located in opposite
+corners of a diamond spin cluster. It is shown that the spin-1 Heisenberg
+diamond cluster exhibits several intriguing quantum ground states, which are
+manifested in low-temperature magnetization curves as intermediate plateaus at
+1/4, 1/2 and 3/4 of the saturation magnetization. Besides, the spin-1
+Heisenberg diamond cluster may also exhibit an enhanced magnetocaloric effect,
+which may be relevant for a low-temperature refrigeration achieved through the
+adiabatic demagnetization. It is evidenced that the spin-1 Heisenberg diamond
+cluster with the antiferromagnetic coupling constants J1/kB = 41.4 K and J2/kB
+= 9.2 K satisfactorily reproduces a low-temperature magnetization curve
+recorded for the tetranuclear nickel complex [Ni4(CO3)2(aetpy)8](ClO4)4 (aetpy
+= 2-aminoethyl-pyridine) including a size and position of intermediate plateaus
+detected at 1/2 and 3/4 of the saturation magnetization. A microscopic nature
+of fractional magnetization plateaus observed experimentally is clarified and
+interpreted in terms of valence-bond crystal with either a single or double
+valence bond. It is suggested that this frustrated magnetic molecule can
+provide a prospective cryogenic coolant with the maximal isothermal entropy
+change - Delta S = 10.6 J/(K.kg) in a temperature range below 2.3 K.",2010.02535v1
+2020-08-10,"Rapid, $B_1$-insensitive, dual-band quasi-adiabatic saturation transfer with optimal control for complete quantification of myocardial ATP flux","Purpose: Phosphorus saturation-transfer experiments can quantify metabolic
+fluxes non-invasively. Typically, the forward flux through the creatine-kinase
+reaction is investigated by observing the decrease in phosphocreatine (PCr)
+after saturation of $\gamma$-ATP. The quantification of total ATP utilisation
+is currently under-explored, as it requires simultaneous saturation of
+inorganic phosphate (Pi) and PCr. This is challenging, as currently available
+saturation pulses reduce the already-low $\gamma$-ATP signal present.
+  Methods: Using a hybrid optimal-control and Shinnar-Le-Roux method, a
+quasi-adiabatic RF pulse was designed for the dual-saturation of PCr and Pi to
+enable determination of total ATP utilisation. The pulses were evaluated in
+Bloch equation simulations, compared with a conventional hard-cosine DANTE
+saturation sequence, before application to perfused rat hearts at 11.7 Tesla.
+  Results: The quasi-adiabatic pulse was insensitive to a $>2.5$-fold variation
+in $B_1$, producing equivalent saturation with a 53% reduction in delivered
+pulse power and a 33-fold reduction in spillover at the minimum effective
+$B_1$. This enabled the complete quantification of the synthesis and
+degradation fluxes for ATP in 30-45 minutes in the perfused rat heart. While
+the net synthesis flux ($4.24\pm0.8$ mM/s, SEM) was not significantly different
+from degradation flux ($6.88\pm2$ mM/s, $p=0.06$) and both measures are
+consistent with prior work, nonlinear error analysis highlights uncertainties
+in the Pi-to-ATP measurement that may explain a trend suggesting a possible
+imbalance.
+  Conclusion: This work demonstrates a novel quasi-adiabatic dual-saturation RF
+pulse with significantly improved performance that can be used to measure ATP
+turnover in the heart in vivo.",2008.04261v2
+2001-07-31,The Relationship Between the Circular Polarization and the Magnetic Field for Astrophysical Masers with Weak Zeeman Splitting,"The relationship between the magnetic field and the circular polarization of
+astrophysical maser radiation due to the Zeeman effect under idealized
+conditions is investigated when the Zeeman splitting is much smaller than the
+spectral linebreadth and when radiative saturation is significant. The
+description of the circular polarization, as well as inferences about the
+magnetic field from the observations, are clearest when the rate for stimulated
+emission is much less than the Zeeman splitting. The calculations here are
+performed in this regime, which is relevant for some (if not most) observations
+of astrophysical masers. We demonstrate that Stokes-$V$ is proportional to the
+Zeeman splitting and the fractional linear polarization is independent of the
+Zeeman splitting when the ratio of the Zeeman splitting to the spectral line
+breadth is small---less than about 0.1. In contrast to its behavior for
+ordinary spectral lines, the circular polarization for masers that are at least
+partially saturated does not decrease with increasing angle between the
+magnetic field and the line-of-sight until they are nearly perpendicular.",0107599v1
+2001-10-08,The effect of hyperdiffusivity on turbulent dynamos with helicity,"In numerical studies of turbulence, hyperviscosity is often used as a tool to
+extend the inertial subrange and to reduce the dissipative subrange. By
+analogy, hyperdiffusivity (or hyperresistivity) is sometimes used in
+magnetohydrodynamics. The underlying assumption is that only the small scales
+are affected by this manipulation. In the present paper, possible side effects
+on the evolution of the large scale magnetic field are investigated. It is
+found that for turbulent flows with helicity, hyperdiffusivity causes the
+dynamo-generated magnetic field to saturate at a higher level than normal
+diffusivity. This result is successfully interpreted in terms of magnetic
+helicity conservation, which also predicts that full saturation is only reached
+after a time comparable to the large scale magnetic (hyper)diffusion time.",0110171v1
+2003-08-14,Saturated State of the Nonlinear Small-Scale Dynamo,"We consider the problem of incompressible, forced, nonhelical, homogeneous
+and isotropic MHD turbulence with no mean magnetic field and large magnetic
+Prandtl number. This type of MHD turbulence is the end state of the turbulent
+dynamo, which generates folded fields with small-scale direction reversals. We
+propose a model in which saturation is achieved as a result of the velocity
+statistics becoming anisotropic with respect to the local direction of the
+magnetic folds. The model combines the effects of weakened stretching and
+quasi-two-dimensional mixing and produces magnetic-energy spectra in remarkable
+agreement with numerical results at least in the case of a one-scale flow. We
+conjecture that the statistics seen in numerical simulations could be explained
+as a superposition of these folded fields and Alfv\'en-like waves that
+propagate along the folds.",0308252v2
+2004-03-13,Magnetic activity in late-type giant stars: Numerical MHD simulations of non-linear dynamo action in Betelgeuse,"Evidence is presented from numerical magneto-hydrodynamical simulations for
+the existence of magnetic activity in late-type giant stars. A red supergiant
+with stellar parameters similar to that of Betelgeuse (alpha Orionis) is
+modeled as a ""star-in-a-box"" with the high-order ""Pencil Code"". Both linear
+kinematic and non-linear saturated dynamo action are found: the non-linear
+magnetic field saturates at a super-equipartition value (a factor two above
+equipartition yielding surface fields with strengths on the order of 500
+Gauss), while in the linear regime two different modes of dynamo action are
+found. It is speculated that magnetic activity of late-type giants may
+influence dust and wind formation and possibly lead to the heating of the outer
+atmospheres of these stars.",0403321v1
+2003-06-12,On Aharonov-Bohm oscillation in a ferromagnetic ring,"Aharonov-Bohm effect in a ferromagnetic thin ring in diffusive regime is
+theoretically studied by calculating the Cooperon and Diffuson. In addition to
+the spin-orbit interaction, we include the spin-wave excitation and the spin
+splitting, which are expected to be dominant sources of dephasing in
+ferromagnets at low temperatures. The spin splitting turns out to kill the
+spin-flip channel of Cooperon but leaves the spin-conserving channel untouched.
+For the experimental confirmation of interference effect (described by
+Cooperons) such as weak localization and Aharonov-Bohm oscillation with period
+$h/2e$, we need to suppress the dominant dephasing by orbital motion. To do
+this we propose experiments on a thin film or thin ring with magnetization and
+external field perpendicular to the film, in which case the effective field
+inside the sample is equal to the external field (magnetization does not add
+up). The field is first applied strong enough to saturate the magnetization and
+then carrying out the measurement down to zero field keeping the magnetization
+nearly saturated, in order to avoid domain formations (negative fields may also
+be investigated if the coercive field is large enough).",0306309v1
+2006-09-11,"$^{133}$Cs NMR investigation of 2D frustrated Heisenberg antiferromagnet, Cs$_2$CuCl$_4$","We report $^{133}$Cs nuclear magnetic resonance (NMR) measurements on the 2D
+frustrated Heisenberg antiferromagnet Cs$_2$CuCl$_4$ down to 2 K and up to 15
+T. We show that $^{133}$Cs NMR is a good probe of the magnetic degrees of
+freedom in this material. Cu spin degrees of freedom are sensed through a
+strong anisotropic hyperfine coupling. The spin excitation gap opens above the
+critical saturation field. The gap value was determined from the activation
+energy of the nuclear spin-lattice relaxation rate in a magnetic field applied
+parallel to the Cu chains (b axis). The values of the g-factor and the
+saturation field are consistent with the neutron-scattering and magnetization
+results. The measurements of the spin-spin relaxation time are exploited to
+show that no structural changes occur down to the lowest temperatures
+investigated.",0609256v1
+2008-02-22,Three-dimensional stability of magnetically confined mountains on accreting neutron stars,"We examine the hydromagnetic stability of magnetically confined mountains,
+which arise when material accumulates at the magnetic poles of an accreting
+neutron star. We extend a previous axisymmetric stability analysis by
+performing three-dimensional simulations using the ideal-magnetohydrodynamic
+(ideal-MHD) code \textsc{zeus-mp}, investigating the role played by boundary
+conditions, accreted mass, stellar curvature, and (briefly) toroidal magnetic
+field strength. We find that axisymmetric equilibria are susceptible to the
+undular sub-mode of the Parker instability but are not disrupted. The
+line-tying boundary condition at the stellar surface is crucial in stabilizing
+the mountain. The nonlinear three-dimensional saturation state of the
+instability is characterized by a small degree of nonaxisymmetry ($\la 0.1$ per
+cent) and a mass ellipticity of $\epsilon \sim 10^{-5}$ for an accreted mass of
+$M_a = 10^{-5} M_\odot$. Hence there is a good prospect of detecting
+gravitational waves from accreting millisecond pulsars with long-baseline
+interferometers such as Advanced LIGO. We also investigate the ideal-MHD
+spectrum of the system, finding that long-wavelength poloidal modes are
+suppressed in favour of toroidal modes in the nonaxisymmetric saturation state.",0802.3238v1
+2008-03-07,Nonlinear Saturation of the Weibel Instability in a Dense Fermi Plasma,"We present an investigation for the generation of intense magnetic fields in
+dense plasmas with an anisotropic electron Fermi-Dirac distribution. For this
+purpose, we use a new linear dispersion relation for transverse waves in the
+Wigner-Maxwell dense quantum plasma system. Numerical analysis of the
+dispersion relation reveals the scaling of the growth rate as a function of the
+Fermi energy and the temperature anisotropy. The nonlinear saturation level of
+the magnetic fields is found through fully kinetic simulations, which indicates
+that the final amplitudes of the magnetic fields are proportional to the linear
+growth rate of the instability. The present results are important for
+understanding the origin of intense magnetic fields in dense Fermionic plasmas,
+such as those in the next generation intense laser-solid density plasma
+experiments.",0803.1036v1
+2009-05-21,Long-range Ni/Mn structural order in epitaxial double perovskite La2NiMnO6 thin films,"We report and compare the structural, magnetic, and optical properties of
+ordered La2NiMnO6 thin films and its disordered LaNi0.5Mn0.5O3 counterpart. An
+x-ray diffraction study reveals that the B-site Ni/Mn ordering induces
+additional XRD reflections as the crystal symmetry is transformed from a
+pseudocubic perovskite unit cell in the disordered phase to a monoclinic form
+with larger lattice parameters for the ordered phase. Polarized Raman
+spectroscopy studies reveal that the ordered samples are characterized by
+additional phonon excitations that are absent in the disordered phase. The
+appearance of these additional phonon excitations is interpreted as the
+clearest signature of Brillouin zone folding as a result of the long-range
+Ni/Mn ordering in La2NiMnO6. Both ordered and disordered materials display a
+single ferromagnetic-to-paramagnetic transition. The ordered films display also
+a saturation magnetization close to 4.8 mB/f.u. and a transition temperature
+(FM-TC) around 270 K, while the disordered ones have only a 3.7 mB/f.u.
+saturation magnetization and a FM-TC around 138 K. The differences in their
+magnetic behaviours are understood based on the distinct local electronic
+configurations of their Ni/Mn cations.",0905.3550v1
+2009-08-24,The two-dimensional frustrated Heisenberg model on the orthorhombic lattice,"We discuss new high-field magnetization data recently obtained by Tsirlin et
+al. for layered vanadium phosphates in the framework of the square-lattice
+model. Our predictions for the saturation fields compare exceptionally well to
+the experimental findings, and the strong bending of the curves below
+saturation agrees very well with the experimental field dependence. Furthermore
+we discuss the remarkably good agreement of the frustrated Heisenberg model on
+the square lattice in spite of the fact that the compounds described with this
+model actually have a lower crystallographic symmetry. We present results from
+our calculations on the thermodynamics of the model on the orthorhombic (i.e.,
+rectangular) lattice, in particular the temperature dependence of the magnetic
+susceptibility. This analysis also sheds light on the discussion of magnetic
+frustration and anisotropy of a class of iron pnictide parent compounds, where
+several alternative suggestions for the magnetic exchange models were proposed.",0908.3442v1
+2011-02-03,Strongly enhanced magnetic moments in ferromagnetic FeMnP$_{0.50}$Si$_{0.50}$,"The compound FeMnP$_{0.50}$Si$_{0.50}$ has been studied by magnetic
+measurements, M\""ossbauer spectroscopy and electronic structure and total
+energy calculations. An unexpected high magnetic hyperfine field for Fe atoms
+located at the tetrahedral Me(1) site in the Fe$_2$P structure is found. The
+saturation moment derived from magnetic measurements corresponds to 4.4
+$\mu_B$/f.u. at low temperatures, a value substantially higher than previously
+reported, but in accord with the results from our electron structure
+calculations. This high saturation moment, a first order nature of the
+ferromagnetic transition and a tunable transition temperature make the
+Fe$_{2-x}$Mn$_{x}$P$_{1-y}$Si$y$ system promising for magnetocaloric
+applications.",1102.0636v1
+2011-07-02,Energy dissipation and switching delay in spin-transfer torque switching of nanomagnets with low-saturation magnetization in the presence of thermal fluctuations,"A common ploy to reduce the switching current and energy dissipation in
+spin-transfer-torque driven magnetization switching of shape-anisotropic
+single-domain nanomagnets is to employ magnets with low saturation
+magnetization $M_s$ and high shape-anisotropy. The high shape-anisotropy
+compensates for low $M_s$ to keep the static switching error rate constant.
+However, this ploy increases the switching delay, its variance in the presence
+of thermal noise, and the dynamic switching error rate. Using the stochastic
+Landau-Lifshitz-Gilbert equation with a random torque emulating thermal noise,
+we show that pumping some excess spin-polarized current into the nanomagnet
+during switching will keep the mean switching delay and its variance constant
+as we reduce $M_s$, while still reducing the energy dissipation significantly.",1107.0387v2
+2011-09-03,Atmospheres of Hot Super-Earths,"Hot super-Earths likely possess minimal atmospheres established through vapor
+saturation equilibrium with the ground. We solve the hydrodynamics of these
+tenuous atmospheres at the surface of Corot-7b, Kepler 10b and 55 Cnc-e,
+including idealized treatments of magnetic drag and ohmic dissipation. We find
+that atmospheric pressures remain close to their local saturation values in all
+cases. Despite the emergence of strongly supersonic winds which carry
+sublimating mass away from the substellar point, the atmospheres do not extend
+much beyond the day-night terminators. Ground temperatures, which determine the
+planetary thermal (infrared) signature, are largely unaffected by exchanges
+with the atmosphere and thus follow the effective irradiation pattern.
+Atmospheric temperatures, however, which control cloud condensation and thus
+albedo properties, can deviate substantially from the irradiation pattern.
+Magnetic drag and ohmic dissipation can also strongly impact the atmospheric
+behavior, depending on atmospheric composition and the planetary magnetic field
+strength. We conclude that hot super-Earths could exhibit interesting
+signatures in reflection (and possibly in emission) which would trace a
+combination of their ground, atmospheric and magnetic properties.",1109.0659v2
+2011-11-30,Radius Dependent Angular Momentum Evolution in Low-Mass Stars. I,"Angular momentum evolution in low-mass stars is determined by initial
+conditions during star formation, stellar structure evolution, and the
+behaviour of stellar magnetic fields. Here we show that the empirical picture
+of angular momentum evolution arises naturally if rotation is related to
+magnetic field strength instead of to magnetic flux, and formulate a corrected
+braking law based on this. Angular momentum evolution then becomes a strong
+function of stellar radius, explaining the main trends observed in open
+clusters and field stars at a few Gyr: the steep transition in rotation at the
+boundary to full convection arises primarily from the large change in radius
+across this boundary, and does not require changes in dynamo mode or field
+topology. Additionally, the data suggest transient core-envelope decoupling
+among solar-type stars, and field saturation at longer periods in very low-mass
+stars. For solar-type stars, our model is also in good agreement with the
+empirical Skumanich law. Finally, in further support of the theory, we show
+that the predicted age at which low-mass stars spin down from the saturated to
+unsaturated field regimes in our model corresponds remarkably well to the
+observed lifetime of magnetic activity in these stars.",1111.7071v1
+2012-12-07,The small scale dynamo and the amplification of magnetic fields in massive primordial haloes,"While present standard model of cosmology yields no clear prediction for the
+initial magnetic field strength, efficient dynamo action may compensate for
+initially weak seed fields via rapid amplification. In particular, the
+small-scale dynamo is expected to exponentially amplify any weak magnetic field
+in the presence of turbulence. We explore whether this scenario is viable using
+cosmological magneto-hydrodynamics simulations modeling the formation of the
+first galaxies, which are expected to form in so-called atomic cooling halos
+with virial temperatures $\rm T_{vir} \geq 10^{4}$ K. As previous calculations
+have shown that a high Jeans resolution is needed to resolve turbulent
+structures and dynamo effects, our calculations employ resolutions of up to 128
+cells per Jeans length. The presence of the dynamo can be clearly confirmed for
+resolutions of at least 64 cells per Jeans length, while saturation occurs at
+approximate equipartition with turbulent energy. As a result of the large
+Reynolds numbers in primordial galaxies, we expect saturation to occur at early
+stages, implying magnetic field strengths of \sim0.1 $\mu$G at densities of
+10^4 cm^{-3}.",1212.1619v2
+2013-01-09,High coercivity induced by mechanical milling in cobalt ferrite powders,"In this work we report a study of the magnetic behavior of ferrimagnetic
+oxide CoFe2O4 treated by mechanical milling with different grinding balls. The
+cobalt ferrite nanoparticles were prepared using a simple hydrothermal method
+and annealed at 500oC. The non-milled sample presented coercivity of about 1.9
+kOe, saturation magnetization of 69.5 emu/g, and a remanence ratio of 0.42.
+After milling, two samples attained coercivity of 4.2 and 4.1 kOe, and
+saturation magnetization of 67.0 and 71.4 emu/g respectively. The remanence
+ratio MR/MS for these samples increase to 0.49 and 0.51, respectively. To
+investigate the influence of the microstructure on the magnetic behavior of
+these samples, we used X-ray powder diffraction (XPD), transmission electron
+microscopy (TEM), and vibrating sample magnetometry (VSM). The XPD analysis by
+the Williamson-Hall plot was used to estimate the average crystallite size and
+strain induced by mechanical milling in the samples.",1301.1945v1
+2013-04-17,Turbulent amplification of magnetic field driven by dynamo effect at rippled shocks,"We derive analytically the vorticity generated downstream of a
+two-dimensional rippled hydromagnetic shock neglecting fluid viscosity and
+resistivity. The growth of the turbulent component of the downstream magnetic
+field is driven by the vortical eddies motion. We determine an analytic
+time-evolution of the magnetic field amplification at shocks, so far described
+only numerically, until saturation occurs due to seed-field reaction to field
+lines whirling. The explicit expression of the amplification growth rate and of
+the non-linear field back-reaction in terms of the parameters of shock and
+interstellar density fluctuations is derived from MHD jump conditions at
+rippled shocks. A magnetic field saturation up to the order of milligauss and a
+short-time variability in the $X$-ray observations of supernova remnants can be
+obtained by using reasonable parameters for the interstellar turbulence.",1304.4956v1
+2013-10-31,Exchange bias associated with phase separation in the Nd2/3Ca1/3MnO3 manganite,"The exchange bias (EB) phenomenon has been found in Nd2/3Ca1/3MnO3
+perovskite. The phenomenon manifests itself as a negative horizontal shift of
+magnetization hysteresis loops. The EB phenomenon is evident of an interface
+exchange coupling between coexisting antiferromagnetic (AFM) and ferromagnetic
+(FM) phases and confirms the phase separated state of the compound at low
+temperatures. The EB effect is found to be strongly dependent on the cooling
+magnetic field and the temperature, which is associated with the evolution of
+spontaneous AFM - FM phase separated state of the compound. Analysis of
+magnetic hysteresis loops has shown that ferromagnetic moment $M_{FM}$
+originating from the FM clusters saturates in a relatively low magnetic field
+about H ~ 0.4T. The obtained saturation value $M_{FM}$(1T) ~ 0.45$\mu_{B}$ is
+in a good agreement with our previous neutron diffraction data.",1310.8590v1
+2013-11-13,Fokker-Planck approach to the theory of magnon-driven spin Seebeck effect,"Following the theoretical approach by Xiao et al [Phys. Rev. B 81, 214418
+(2010)] to the spin Seebeck effect, we calculate the mean value of the total
+spin current flowing through a normalmetal/ ferromagnet interface. The spin
+current emitted from the ferromagnet to the normal metal is evaluated in the
+framework of the Fokker-Planck approach for the stochastic
+Landau-Lifshitz-Gilbert equation. We show that the total spin current depends
+not only on the temperature difference between the electron and the magnon
+baths, but also on the external magnetic field and magnetic anisotropy. Apart
+from this, the spin current is shown to saturate with increasing magnon
+temperature, and the saturation temperature increases with increasing magnetic
+field and/or magnetic anisotropy.",1311.3117v1
+2014-01-31,Firehose and Mirror Instabilities in a Collisionless Shearing Plasma,"Hybrid-kinetic numerical simulations of firehose and mirror instabilities in
+a collisionless plasma are performed in which pressure anisotropy is driven as
+the magnetic field is changed by a persistent linear shear $S$. For a
+decreasing field, it is found that mostly oblique firehose fluctuations grow at
+ion Larmor scales and saturate with energies $\sim$$S^{1/2}$; the pressure
+anisotropy is pinned at the stability threshold by particle scattering off
+microscale fluctuations. In contrast, nonlinear mirror fluctuations are large
+compared to the ion Larmor scale and grow secularly in time; marginality is
+maintained by an increasing population of resonant particles trapped in
+magnetic mirrors. After one shear time, saturated order-unity magnetic mirrors
+are formed and particles scatter off their sharp edges. Both instabilities
+drive sub-ion-Larmor--scale fluctuations, which appear to be
+kinetic-Alfv\'{e}n-wave turbulence. Our results impact theories of momentum and
+heat transport in astrophysical and space plasmas, in which the stretching of a
+magnetic field by shear is a generic process.",1402.0010v2
+2014-04-10,Thermal effect on magnetic parameters of high-coercivity cobalt ferrite,"We prepared very high-coercivity cobalt ferrite nanoparticles using
+short-time high-energy mechanical milling. After the milling process, the
+coercivity of the nanoparticles reached 3.75 kOe - a value almost five times
+higher than that obtained for the non-milled sample. We performed a thermal
+treatment on the milled sample at 300, 400, and 600 oC for 30 and 180 mins, and
+studied the changes in the magnetic parameters due to the thermal treatment
+using the hysteresis curves, Williamson-Hall analysis, and transmission
+electron microscopy. The thermal treatment at 600 oC causes a decrease in the
+microstructural strain and density of structural defects resulting in a
+significant decrease in coercivity. Furthermore, this thermal treatment
+increases the size of the nanoparticles and, as a consequence, there is a
+substantial increase in the saturation magnetization. The coercivity and the
+saturation magnetization are less affected by the thermal treatment at 300 and
+400 oC.",1404.2965v1
+2014-11-21,"Structural transitions, magnetic properties, and electronic structures of Co(Fe)-doped MnNiSi compounds","The structural transitions, magnetic properties, and electronic structures of
+Co(Fe)-doped MnNiSi compounds are investigated by x-ray powder diffraction
+(XRD), differential scanning calorimetry (DSC), magnetic measurements, and
+first-principles calculations. Results indicate that all samples undergo a
+martensitic transition from the Ni2In-type parent phase to TiNiSi-type
+orthorhombic phase at high temperatures. The substitution of Co(Fe) for Mn in
+Mn1-xCoxNiSi (x = 0.2, 0.3, 0.4) and Mn1-yFeyNiSi (y = 0.26, 0.30, 0.36, 0.46,
+0.55) samples decreases the structural transition temperature (Tt) and Curie
+temperature of martensite (TCM). The martensite phases show a typical
+ferromagnetic behavior with saturation field (HS) being basically unchanged
+with increasing Co(Fe) content, while the saturation magnetization (MS) shows a
+decreasing tendency. The theoretically calculated moments are in good agreement
+with the experimentally measured results. The orbital hybridizations between
+different 3d elements are analyzed from the distribution of density of states.",1411.5766v1
+2015-06-01,Evaluation of (BH)max and magnetic anisotropy of cobalt ferrite nanoparticles synthesized in gelatin,"CoFe2O4 nanoparticles were synthesized using gelatin as a polymerizing agent.
+Structural, morphological and magnetic properties of samples treated at
+different temperatures were investigated by X-ray diffraction, scanning
+electron microscopy, Mossbauer spectroscopy and magnetization measurements. Our
+results revealed that the samples annealed at 623 K and temperatures above 973
+K have a cation distributions given by (Co0.19Fe0.81)[Co0.81Fe1.19]O4 and
+(Co0.06Fe0.94)[Co0.94Fe1.06]O4, respectively. The particle sizes varied from 73
+to 296 nm and the magnetocrystalline anisotropy, K1, has values ranging from
+2.60x10^6 to 2.71x10^6 J/m3, as determined from the law of approach to
+saturation applied to the MxH data at high field. At 5 K, the saturation
+magnetization, coercive field and (BH)max varied from 76 to 95 Am2/kg, 479.9 to
+278.5 kA/m and 9.7 to 20.9 kJ/m3, respectively. The reported values are in good
+agreement with near-stoichiometric cobalt ferrite samples.",1506.00505v1
+2018-04-29,"The mirror mode: A ""superconducting'' space plasma analogue","We examine the physics of the magnetic mirror mode in its final state of
+saturation, the thermodynamic equilibrium, to demonstrate that the mirror mode
+is the analogue of a superconducting effect in a classical anisotropic-pressure
+space plasma. Two different spatial scales are identified which control the
+behaviour of its evolution. These are the ion inertial scale
+$\lambda_{im}(\tau)$ based on the excess density $N_m(\tau)$ generated in the
+mirror mode, and a correlation length. This can be either the Debye length, the
+ion gyro-radius, or a turbulent correlation length. The mirror mode equilibrium
+structure under saturation is determined by the Landau-Ginzburg ratio of these
+two length scales. Mirror modes then behave like type II superconductors,
+naturally giving rise to chains of local depletions of the magnetic field of
+the kind observed in the mirror mode, providing the plasma a short scale
+magnetic bubble texture. This might be important in the study of magnetic
+turbulence in plasmas.",1804.10900v2
+2019-08-21,One- and three-dimensional quantum phase transitions and anisotropy in Rb$_{2}$Cu$_{2}$Mo$_{3}$O$_{12}$,"Single crystal samples of the frustrated quasi one-dimensional quantum magnet
+Rb$_{2}$Cu$_{2}$Mo$_{3}$O$_{12}$ are investigated by magnetic, thermodynamic,
+and electron spin resonance (ESR) measurements. Quantum phase transitions
+between the gapped, magnetically ordered and fully saturated phases are
+observed. Surprisingly, the former has a distinctive three-dimensional
+character, while the latter is dominated by one-dimensional quantum spin
+fluctuations. The entire $H$-$T$ phase diagram is mapped out and found to be
+substantially anisotropic. In particular, the lower critical fields differ by
+over 50\% depending on the direction of applied field, while the upper ones are
+almost isotropic, as is the magnetization above saturation. The ESR spectra are
+strongly dependent on field orientation and point to a helical structure with a
+rigidly defined spin rotation plane.",1908.07739v3
+2019-11-18,Large Scale Dynamo in a Primordial Accretion Flow -- An Interpretation from Hydrodynamic Simulation,"Without an existing large scale coherent magnetic field in the early
+Universe, Population III (PopIII) stars would likely rotate at or near break-up
+speed. In this work, focusing on the accretion phase of PopIII stars, we
+investigate the possibility of generating a coherent magnetic field through
+large scale dynamo processes, as well as the corresponding field saturation
+level. Using results from hydrodynamic simulations, we demonstrate that
+primordial accretion disks are turbulent with a Shakura-Sunyaev disk parameter
+$\alpha_{ss} \gtrsim 10^{-3}$, and evidence helical turbulence with a dynamo
+number $\vert D_{\alpha \Omega} \vert \gg 10$. The presence of helical
+turbulence at these levels allows large scale dynamo modes to grow, and the
+saturation level is determined by the amount of net helicity remaining in the
+dynamo-active regions (a.k.a. the quenching problem). %We demonstrate that the
+magnetic field can reach approximate equipartition, with $B/B_{\rm eq} \sim 3$,
+indicating that the dynamo quenching problem could be alleviated through an
+accretion flow. We demonstrate that, if the accretion could successfully
+alleviate the quenching problem, the magnetic field can reach approximate
+equipartition with $B/B_{\rm eq} \sim 3$.",1911.07898v1
+2020-02-14,Two-channel anomalous Hall effect in SrRuO3,"The Hall effect in SrRuO$_3$ thin-films near the thickness limit for
+ferromagnetism shows an extra peak in addition to the ordinary and anomalous
+Hall effects. This extra peak has been attributed to a topological Hall effect
+due to two-dimensional skyrmions in the film around the coercive field;
+however, the sign of the anomalous Hall effect in SrRuO$_3$ can change as a
+function of saturation magnetization. Here we report Hall peaks in SrRuO$_3$ in
+which volumetric magnetometry measurements and magnetic force microscopy
+indicate that the peaks result from the superposition of two anomalous Hall
+channels with opposite sign. These channels likely form due to thickness
+variations in SrRuO$_3$, creating two spatially separated magnetic regions with
+different saturation magnetizations and coercive fields. The results are
+central to the development of strongly correlated materials for spintronics.",2002.06062v2
+2020-09-07,Magnetic Binary Supersaturated Solid Solutions Processed by Severe Plastic Deformation,"Samples consisting of one ferromagnetic and one diamagnetic component which
+are immiscible at the thermodynamic equilibrium (Co-Cu, Fe-Cu, Fe-Ag) are
+processed by high-pressure torsion at various compositions. The received
+microstructures are investigated by electron microscopy and synchrotron X-ray
+diffraction, showing a microstructural saturation. Results gained from
+microstructural investigations are correlated to magnetometry data. The Co-Cu
+samples show mainly ferromagnetic behavior and a decrease in coercivity with
+increasing Co-content. The saturation microstructure of Fe-Cu samples is found
+to be dual phase. Results of magnetic measurements also revealed the occurrence
+of two different magnetic phases in this system. For Fe-Ag, the microstructural
+and magnetic results indicate that no intermixing between the elemental phases
+takes place.",2009.02939v1
+2020-10-22,Pressure-tuned intralayer exchange in superlattice-like MnBi2Te4/(Bi2Te3)n topological insulators,"The magnetic structures of MnBi2Te4(Bi2Te3)n can be manipulated by tuning the
+interlayer coupling via the number of Bi2Te3 spacer layers n, while the
+intralayer ferromagnetic (FM) exchange coupling is considered too robust to
+control. By applying hydrostatic pressure up to 3.5 GPa, we discover opposite
+responses of magnetic properties for n = 1 and 2. MnBi4Te7 stays at A-type
+antiferromagnetic (AFM) phase with a decreasing N\'eel temperature and an
+increasing saturation field. In sharp contrast, MnBi6Te10 experiences a phase
+transition from A-type AFM to a quasi-two-dimensional FM state with a
+suppressed saturation field under pressure. First-principles calculations
+reveal the essential role of intralayer exchange coupling from lattice
+compression in determining these magnetic properties. Such magnetic phase
+transition is also observed in 20% Sb-doped MnBi6Te10 due to the in-plane
+lattice compression.",2010.11466v2
+2020-12-20,Reconstructing phase-resolved hysteresis loops from first-order reversal curves,"The first order reversal curve (FORC) method is a magnetometry based
+technique used to capture nanoscale magnetic phase separation and interactions
+with macroscopic measurements using minor hysteresis loop analysis. This makes
+the FORC technique a powerful tool in the analysis of complex systems which
+cannot be effectively probed using localized techniques. However, recovering
+quantitative details about the identified phases which can be compared to
+traditionally measured metrics remains an enigmatic challenge. We demonstrate a
+technique to reconstruct phase-resolved magnetic hysteresis loops by
+selectively integrating the measured FORC distribution. From these minor loops,
+the traditional metrics - including the coercivity and saturation field, and
+the remanent and saturation magnetization - can be determined. In order to
+perform this analysis, special consideration must be paid to the accurate
+quantitative management of the so-called reversible features. This technique is
+demonstrated on three representative materials systems, high anisotropy FeCuPt
+thin-films, Fe nanodots, and SmCo/Fe exchange spring magnet films, and shows
+excellent agreement with the direct measured major loop, as well as the phase
+separated loops.",2012.11041v1
+2023-07-10,Optical-power-dependent splitting of magnetic resonance in nitrogen-vacancy centers in diamond,"Nitrogen-vacancy (NV) centers in diamonds are a powerful tool for accurate
+magnetic field measurements. The key is precisely estimating the
+field-dependent splitting width of the optically detected magnetic resonance
+(ODMR) spectra of the NV centers. In this study, we investigate the optical
+power dependence of the ODMR spectra using NV ensemble in nanodiamonds (NDs)
+and a single-crystal bulk diamond. We find that the splitting width
+exponentially decays and is saturated as the optical power increases.
+Comparison between NDs and a bulk sample shows that while the decay amplitude
+is sample-dependent, the optical power at which the decay saturates is almost
+sample-independent. We propose that this unexpected phenomenon is an intrinsic
+property of the NV center due to non-axisymmetry deformation or impurities. Our
+finding indicates that diamonds with less deformation are advantageous for
+accurate magnetic field measurements.",2307.04414v1
+2023-09-19,Multiple Magnetoelectric Plateaux in Polar Magnet Fe$_2$Mo$_3$O$_8$,"The magnetization and electric polarization of a polar antiferromagnet
+Fe$_2$Mo$_3$O$_8$ are studied up to 66 T for spin-saturation magnetic fields
+applied along the polar axis. The magnetization process at 1.4 K exhibited
+multistep structures below the saturation field of 65 T. The electric
+polarization along the polar axis exhibits a similar multistep behavior with a
+total change of 1.2 $\rm{\mu}C/cm^{2}$. A combined triangular-lattice
+antiferromagnetic model with strong Ising-type spin anisotropy reproduces this
+multistep magnetoelectric (ME) effect. The exchange striction mechanism
+explains the remarkable ME response in the two sub-lattice type-I multiferroic
+materials. These results and interpretation demonstrate a method for realizing
+multistage magnetoelectric effects in hybrid spin systems.",2309.10583v1
+2004-10-20,Nonlinear saturation of magnetic curvature driven Rayleigh Taylor instability in three dimensions,"We present three dimensional fluid simulation results on the temporal
+evolution and nonlinear saturation of the magnetic curvature driven
+Rayleigh-Taylor (RT) instability. The model set of coupled nonlinear equations
+evolve the scalar electric field potential $\phi$, plasma density $n$ and the
+parallel component of the magnetic vector potential $\psi$. The simulations
+have been carried out in two limits, (i) a low resistivity case in which RT is
+the only linearly growing mode, and (ii) a high resistivity case where the
+drift wave is unstable and for which the magnetic curvature parameter is set to
+zero to ensure the absence of the RT growth. Our simulations show nonlinear
+stabilization in both these limits. The stabilization mechanism is similar to
+that observed in earlier two dimensional simulations, namely the generation of
+zonal shear flows which decorrelate the radially extended unstable modes.
+However the nature of the saturated nonlinear state in the 3d case differs from
+that of 2d in some important ways such as by having significant levels of power
+in short scales and by the presence of electromagnetic fluctuations. Though, in
+the linear regime the electromagnetic effects reduce the growth rates, in the
+nonlinear regime their presence hinders the process of stabilization by
+inhibiting the process of zonal flow formation. Thus the parameter regime for
+which nonlinear stabilization takes place is considerably reduced in three
+dimensions.",0410178v1
+2014-01-21,Exploring the magnetic field complexity in M dwarfs at the boundary to full convection,"Based on detailed spectral synthesis we carry out quantitative measurements
+of the strength and complexity of surface magnetic fields in the four
+well-known M-dwarfs GJ 388, GJ 729, GJ 285, and GJ 406 populating the mass
+regime around the boundary between partially and fully convective stars. Very
+high resolution R=100000, high signal-to-noise (up to 400) near-infrared Stokes
+I spectra were obtained with CRIRES at ESO's Very Large Telescope covering
+regions of the FeH Wing-Ford transitions at 1mum. The field distributions in
+all four stars are characterized by three distinct groups of field components,
+the data are neither consistent with a smooth distribution of different field
+strengths, nor with one average field strength covering the full star. We find
+evidence of a subtle difference in the field distribution of GJ 285 compared to
+the other three targets. GJ 285 also has the highest average field of 3.5kG and
+the strongest maximum field component of 7-7.5kG. The maximum local field
+strengths in our sample seem to be correlated with rotation rate. While the
+average field strength is saturated, the maximum local field strengths in our
+sample show no evidence for saturation. We find no difference between the field
+distributions of partially and fully convective stars. The one star with
+evidence for a field distribution different to the other three is the most
+active star (i.e. with largest x-ray luminosity and mean surface magnetic
+field) rotating relatively fast. A possible explanation is that rotation
+determines the distribution of surface magnetic fields, and that local field
+strengths grow with rotation even in stars in which the average field is
+already saturated.",1401.5250v1
+2015-01-16,Direct measurement of the magnetic anisotropy field in Mn--Ga and Mn--Co--Ga Heusler films,"The static and dynamic magnetic properties of tetragonally distorted Mn--Ga
+based alloys were investigated. Static properties are determined in magnetic
+fields up to 6.5~T using SQUID magnetometry. For the pure Mn$_{1.6}$Ga film,
+the saturation magnetisation is 0.36~MA/m and the coercivity is 0.29~T. Partial
+substitution of Mn by Co results in Mn$_{2.6}$Co$_{0.3}$Ga$_{1.1}$. The
+saturation magnetisation of those films drops to 0.2~MA/m and the coercivity is
+increased to 1~T.
+  Time-resolved magneto-optical Kerr effect (TR-MOKE) is used to probe the
+high-frequency dynamics of Mn--Ga. The ferromagnetic resonance frequency
+extrapolated to zero-field is found to be 125~GHz with a Gilbert damping,
+$\alpha$, of 0.019. The anisotropy field is determined from both SQUID and
+TR-MOKE to be 4.5~T, corresponding to an effective anisotropy density of
+0.81~MJ/m$^3$.
+  Given the large anisotropy field of the Mn$_{2.6}$Co$_{0.3}$Ga$_{1.1}$ film,
+pulsed magnetic fields up to 60~T are used to determine the field strength
+required to saturate the film in the plane. For this, the extraordinary Hall
+effect was employed as a probe of the local magnetisation. By integrating the
+reconstructed in--plane magnetisation curve, the effective anisotropy energy
+density for Mn$_{2.6}$Co$_{0.3}$Ga$_{1.1}$ is determined to be 1.23~MJ/m$^3$.",1501.03973v1
+2015-10-23,Quantum Critical Scaling for a Heisenberg Spin-$1/2$ Chain around Saturation,"We demonstrate quantum critical scaling for an $S=1/2$ Heisenberg
+antiferromagnetic chain compound CuPzN in a magnetic field around saturation,
+by analysing previously reported magnetization [Y. Kono {\it et al.}, Phys.
+Rev. Lett. {\bf 114}, 037202 (2015)], thermal expansion [J. Rohrkamp {\it et
+al.}, J. Phys.: Conf. Ser. {\bf 200}, 012169 (2010)] and NMR relaxation data
+[H. K\""uhne {\it et al.}, Phys. Rev. B {\bf 80}, 045110 (2009)]. The scaling of
+magnetization is demonstrated through collapsing the data for a range of both
+temperature and field onto a single curve without making any assumption for a
+theoretical form. The data collapse is subsequently shown to closely follow the
+theoretically-predicted scaling function without any adjustable parameters.
+Experimental boundaries for the quantum critical region could be drawn from the
+variable range beyond which the scaled data deviate from the theoretical
+function. Similarly to the magnetization, quantum critical scaling of the
+thermal expansion is also demonstrated. Further, the spin dynamics probed via
+NMR relaxation rate $1/T_1$ close to the saturation is shown to follow the
+theoretically-predicted quantum critical behavior as $1/T_1\propto T^{-0.5}$
+persisting up to temperatures as high as $k_\mathrm{B}T \simeq J$, where $J$ is
+the exchange coupling constant.",1510.07056v1
+2016-11-08,Kondo screening and beyond: an x-ray absorption and dichroism study of CePt$_5$/Pt(111),"We use x-ray absorption spectroscopy as well as its linear and circular
+magnetic dichroisms to characterize relevant interactions and energy scales in
+the surface intermetallic CePt$_5$/Pt(111). The experiments provide insight
+into crystal field splitting, effective paramagnetic moments, their Kondo
+screening and mutual interactions and thus into many aspects which typically
+determine the low temperature behavior of correlated rare earth compounds.
+Exploiting the tuneability of Ce valence through the thickness dependent
+epitaxial strain at the CePt$_5$/Pt(111) interface, we are able to
+systematically investigate the impact of hybridization strength on these
+interactions. Considerable Kondo screening is indeed observed at all CePt$_5$
+thicknesses, and found to be strongest in case of strongest hybridization.
+While the magnetic response is commensurate with an impurity Kondo scale of
+$T_K \gtrsim 10^2$ K for specimen temperatures $T \gtrsim 30$ K, this is no
+longer the case at lower temperature. Its detailed study by XMCD at one
+specific thickness of CePt$_5$ reveals an anomaly of the susceptibility at $T^*
+\approx 25$ K instead, which we tentatively associate with the onset of lattice
+coherence. At lowest temperature we observe paramagnetic saturation with a
+small Ce $4f$ saturation magnetization. Within the framework of itinerant $4f$
+electrons, saturation is due to a field induced Lifshitz transition involving a
+very heavy band with correspondingly small degeneracy temperature of $T_F
+\approx 7$ K. This small energy scale results in the persistence of Curie-Weiss
+behavior across the entire range of experimentally accessible temperatures ($T
+\gtrsim 2$ K). Our work highlights the potential of magnetic circular dichroism
+studies in particular for Kondo and heavy fermion materials, which so far has
+remained largely unexplored.",1611.02599v1
+2017-11-30,"Self-inhibiting thermal conduction in high-beta, whistler-unstable plasma","A heat flux in a high-$\beta$ plasma with low collisionality triggers the
+whistler instability. Quasilinear theory predicts saturation of the instability
+in a marginal state characterized by a heat flux that is fully controlled by
+electron scattering off magnetic perturbations. This marginal heat flux does
+not depend on the temperature gradient and scales as $1/\beta$. We confirm this
+theoretical prediction by performing numerical particle-in-cell simulations of
+the instability. We further calculate the saturation level of magnetic
+perturbations and the electron scattering rate as functions of $\beta$ and the
+temperature gradient to identify the saturation mechanism as quasilinear.
+Suppression of the heat flux is caused by oblique whistlers with
+magnetic-energy density distributed over a wide range of propagation angles.
+This result can be applied to high-$\beta$ astrophysical plasmas, such as the
+intracluster medium, where thermal conduction at sharp temperature gradients
+along magnetic-field lines can be significantly suppressed. We provide a
+convenient expression for the amount of suppression of the heat flux relative
+to the classical Spitzer value as a function of the temperature gradient and
+$\beta$. For a turbulent plasma, the additional independent suppression by the
+mirror instability is capable of producing large total suppression factors
+(several tens in galaxy clusters) in regions with strong temperature gradients.",1711.11462v3
+2019-02-26,Enhanced Gilbert Damping in Re doped FeCo Films: A Combined Experimental and Theoretical Study,"The effects of rhenium doping in the range 0 to 10 atomic percent on the
+static and dynamic magnetic properties of Fe65Co35 thin films have been studied
+experimentally as well as with first principles electronic structure
+calculations focusing on the change of the saturation magnetization and the
+Gilbert damping parameter. Both experimental and theoretical results show that
+the saturation magnetization decreases with increasing Re doping level, while
+at the same time Gilbert damping parameter increases. The experimental low
+temperature saturation magnetic induction exhibits a 29 percent decrease, from
+2.31 T to 1.64 T, in the investigated doping concentration range, which is more
+than predicted by the theoretical calculations. The room temperature value of
+the damping parameter obtained from ferromagnetic resonance measurements,
+correcting for extrinsic contributions to the damping, is for the undoped
+sample 0.0027, which is close to the theoretically calculated Gilbert damping
+parameter. With 10 atomic percent Re doping, the damping parameter increases to
+0.0090, which is in good agreement with the theoretical value of 0.0073. The
+increase in damping parameter with Re doping is explained by the increase in
+density of states at Fermi level, mostly contributed by the spin-up channel of
+Re. Moreover, both experimental and theoretical values for the damping
+parameter are observed to be weakly decreasing with decreasing temperature.",1902.09896v1
+2019-11-05,General relativistic magnetohydrodynamic dynamo in thick accretion disks: fully nonlinear simulations,"The recent imaging of the M87 black hole at millimeter wavelengths by the
+Event Horizon Telescope (EHT) collaboration has triggered a renewed interest in
+numerical models for the accretion of magnetized plasma in the regime of
+general relativistic magnetohydrodynamics (GRMHD). Here non-ideal simulations,
+including both the resistive effects and, above all, the mean-field dynamo
+action due to sub-scale, unresolved turbulence, are applied for the first time
+to such systems in the fully nonlinear regime. Combined with the differential
+rotation of the disk, the dynamo process is able to produce an exponential
+growth of any initial seed magnetic field up to the values required to explain
+the observations, when the instability tends to saturate even in the absence of
+artificial quenching effects. Before reaching the final saturation stage we
+observe a secondary regime of exponential growing, where the magnetic field
+increases more slowly due to accretion, which is modifying the underlying
+equilibrium. By varying the dynamo coefficient we obtain different growth
+rates, though the field seems to saturate at approximately the same level, at
+least for the limited range of parameters explored here, providing substantial
+values for the MAD parameter for magnetized accretion. For reasonable values of
+the central mass density and the commonly employed recipes for synchrotron
+emission by relativistically hot electrons, our model is able to reproduce
+naturally the observed flux of Sgr A*, the next target for EHT.",1911.01838v1
+2023-07-13,Black Hole Accretion with Saturated Magnetic Pressure and Disk Wind,"We construct an analytical black hole accretion disk model that incorporates
+both magnetic pressure and disk wind, which are found to be important from
+numerical simulations. A saturated magnetic pressure that relates the Alfven
+velocity with local Keplerian velocity and gas sound speed is assumed in
+addition to radiation and gas pressures. The mass accretion rate is assumed to
+have a power-law form in response to mass loss in the wind. We find three sets
+of self-consistent solutions that are thermally stable and satisfy the model
+assumptions. At high accretion rates, the disk is geometrically and optically
+thick, resembling the slim disk solution. At relatively low accretion rates,
+our model predicts an accretion flow consisting of a geometrically thin and
+optically thick outer disk (similar to the standard disk), and a geometrically
+thick and optically thin inner disk (similar to the advection-dominated
+accretion flow or ADAF). Thus, this is a natural solution for a truncated disk
+connected with an inner ADAF, which has been proposed to explain some
+observations. The magnetic pressure plays a more important role than the
+outflow in shaping the disk structure. The observed disk luminosity tends to
+saturate around 8 times the Eddington limit, suggesting that supercritical
+accretion onto black holes can be used for black hole mass estimate, or a
+standard candle with known black hole masses.",2307.06585v1
+2005-09-15,Polarization of Water Masers in the presence of Velocity and Magnetic Field Gradients,"Through polarization observations water masers are excellent probes of
+magnetic fields in the maser region. Magnetic field strengths, such as those in
+the water masers regions of the envelopes of late-type stars and star-forming
+regions, are typically determined using a direct relation between the field
+strength and the observed circular polarization. Here it is shown that velocity
+and magnetic field gradients along the maser have a significant effect on the
+field strengths obtained from circular polarization observations. Due to
+velocity gradients the actual magnetic field strength could be up to 100%
+higher than the field strength derived from the observations. Additionally,
+when a magnetic field gradient is present, the resulting circular polarization
+derived is caused predominantly by the average magnetic field in the
+unsaturated maser core. Measurements of the fractional linear polarization are
+not affected by velocity or magnetic field strength gradients, though changes
+in the magnetic field angle along the maser do quench the linear polarization
+intensity when the maser saturates.",0509435v1
+2002-04-05,Magnetic Phase Transition and Magnetization Plateau in Cs$_2$CuBr$_4$,"The crystal structure of Cs$_2$CuBr$_4$ is the same as that of
+Cs$_2$CuCl$_4$, which has been characterized as a spin-1/2
+quasi-two-dimensional frustrated system. The magnetic properties of
+Cs$_2$CuBr$_4$ were investigated by magnetization and specific heat
+measurements. The phase transition at zero magnetic field was detected at
+$T_{\rm N}=1.4$ K. It was observed that the magnetization curve has a plateau
+at about one-third of the saturation magnetization for magnetic field $H$
+parallel to the $b$- and $c$-axes, while no plateau was observed for
+$H\parallel a$. The field-induced phase transition to the plateau state appears
+to be of the first order. The mechanism leading to the magnetization plateau is
+discussed.",0204125v1
+2006-11-08,Anisotropic magnetic properties of CeAg$_2$Ge$_2$ single crystal,"In order to investigate the anisotropic magnetic properties of
+CeAg$_2$Ge$_2$, we have successfully grown the single crystals, for the first
+time, by high temperature solution growth (flux) method. We have performed a
+detailed study of the grown single crystals by measuring their electrical
+resistivity, magnetic susceptibility, magnetization, specific heat and
+magnetoresistance. A clear anisotropy and an antiferromagnetic transition at
+$T_{\rm N}$ = 4.6 K have been observed in the magnetic properties. The magnetic
+entropy reaches $R$ ln 4 at 20 K indicating that the ground state and the first
+excited state are very closely spaced (a quasi-quartet state). From the
+specific heat measurements and crystalline electric field (CEF) analysis of the
+magnetic susceptibility, we have found the level splitting energies as 5 K and
+130 K. The magnetization measurements reveal that the a-axis is the easy axis
+of magnetization and the saturation moment is $\mu_{\rm s}$ = 1.6 $\mu_{\rm
+B}$/Ce, corroborating the previous neutron diffraction measurements on a
+polycrystalline sample.",0611197v2
+2010-04-02,Structure and magnetic properties of nanocrystalline PrCo3,"The structure and magnetic properties of nanocrystalline PrCo$_3$ prepared by
+high-energy milling technique have been investigated by means of X-ray
+diffraction using the Rietveld method coupled to Curie temperature and magnetic
+measurements. The as-milled samples were subsequently annealed in temperature
+range from 750 to 1050 {\deg}C for 30 min to optimize the extrinsic properties.
+From x-ray studies of magnetic aligned samples, the magnetic anisotropy of this
+compounds is found uniaxial. The Curie temperature is 349 {\deg}K and no
+saturation reached at room temperature for applied field of 90 kOe. The
+coercive field of 55 kOe and 12 kOe measured at 10 and 293 K respectively is
+obtained after annealing at 750 {\deg}C for 30 min suggests that
+nanocrystalline PrCo$_3$ are interesting candidates in the field of permanent
+magnets. We have completed this experimental study by simulations in the
+micromagnetic framework in order to get a qualitative picture of the
+microstructure effect on the macroscopic magnetization curve. From this simple
+model calculation, we can suggest that the after annealing the system behaves
+as magnetically hard crystallites embedded in a weakly magnetized amorphous
+matrix. PACS : 75.50.Bb, 75.50.Tt, 76.80.+y",1004.0307v2
+2013-12-12,Influence of the structure defects on the magnetic properties of the FePt/Fe bilayer,"Thin magnetic multilayered films containing FePt have attracted a lot of
+attention recently due to their possible usage in ultra-high density magnetic
+storage. Although structure defects play a dramatic role in the magnetization
+process and influence magnetic properties in general this dependence haven't
+been studied thoroughly. The main aim of this work was to perform theoretical
+investigation of the magnetic properties of FePt and Fe/FePt thin films with
+high coercivity with respect to the structure defects such as anisotropy
+constant, magnetization saturation, exchange constant fluctuations and easy
+axis deviation. For selected defect patterns the coercive field dependence on
+layer thicknesses was analysed. Numerical study of the bilayer with hard
+magnetic layer having the planar anisotropy was carried on using micromagnetic
+calculations. Values of layers thickness have been found optimal for
+perspective applications, the dependence of the hysteresis loop shape upon the
+magnetization process has been shown and analysed.",1312.3541v1
+2014-03-25,Simulations of magnetic nanoparticle Brownian motion,"Magnetic nanoparticles are useful in many medical applications because they
+interact with biology on a cellular level thus allowing microenvironmental
+investigation. An enhanced understanding of the dynamics of magnetic particles
+may lead to advances in imaging directly in magnetic particle imaging (MPI) or
+through enhanced MRI contrast and is essential for nanoparticle sensing as in
+magnetic spectroscopy of Brownian motion (MSB). Moreover, therapeutic
+techniques like hyperthermia require information about particle dynamics for
+effective, safe, and reliable use in the clinic. To that end, we have developed
+and validated a stochastic dynamical model of rotating Brownian nanoparticles
+from a Langevin equation approach. With no field, the relaxation time toward
+equilibrium matches Einstein's model of Brownian motion. In a static field, the
+equilibrium magnetization agrees with the Langevin function. For high frequency
+or low amplitude driving fields, behavior characteristic of the linearized
+Debye approximation is reproduced. In a higher field regime where magnetic
+saturation occurs, the magnetization and its harmonics compare well with the
+effective field model. On another level, the model has been benchmarked against
+experimental results, successfully demonstrating that harmonics of the
+magnetization carry enough information to infer environmental parameters like
+viscosity and temperature.",1403.6427v1
+2016-03-27,High resolution Kerr microscopy study of exchange bias phenomena in FePt/Fe exchange spring magnets,"Magnetization and magnetic microstructure of top soft magnetic layer (Fe),
+which is exchange spring coupled to bottom hard magnetic layer ($L1_0$ FePt) is
+studied using high resolution Kerr microscopy. When the sample (FePt/Fe) is at
+remanent condition of hard magnetic layer, considerable shifting of Fe layer
+hysteresis loop from centre i.e., exchange bias phenomena is observed. It is
+observed that one can tune the magnitude of exchange bias shift by reaching the
+remanent state from different saturating fields ($H_{SAT}$) and also by varying
+the angle between measuring field and $H_{SAT}$. The M-H loops and domain
+images of top soft Fe layer demonstrates unambiguously that soft magnetic layer
+at remanent state in such exchange coupled system is having unidirectional
+anisotropy. An analogy is drawn and the observations are explained in terms of
+the mostly accepted models of exchange bias phenomena exhibited by bilayers
+consisting of ferromagnetic(FM) and anti-ferromagnetic (AFM) layers, when the
+AFM layer is field cooled across $N\acute{e}el$ transition temperature.",1603.08164v1
+2017-03-22,Magnetization process and magnetocaloric effect in geometrically frustrated Ising antiferromagnet and spin ice models on a `Star of David' nanocluster,"Magnetic and magnetocaloric properties of geometrically frustrated
+antiferromagnetic Ising (IA) and ferromagnetic spin ice (SI) models on a
+nanocluster with a `Star of David' topology, including next-nearest-neighbor
+(NNN) interactions, are studied by an exact enumeration. In an external field
+applied in characteristic directions of the respective models, depending on the
+NNN interaction sign and magnitude, the ground state magnetization of the IA
+model is found to display up to three intermediate plateaus at fractional
+values of the saturation magnetization, while the SI model shows only one
+zero-magnetization plateau and only for the antiferromagnetic NNN coupling. A
+giant magnetocaloric effect is revealed in the the IA model with the NNN
+interaction either absent or equal to the nearest-neighbor coupling. The latter
+is characterized by abrupt isothermal entropy changes at low temperatures and
+infinitely fast adiabatic temperature variations for specific entropy values in
+the processes when the magnetic field either vanishes or tends to the critical
+values related to the magnetization jumps.",1703.07756v1
+2017-10-20,Deterministic switching of perpendicularly magnetic layers by spin orbital torque through stray field engineering,"We proposed a novel multilayer structure to realize the deterministic
+switching of perpendicularly magnetized layers by spin orbital torque from the
+spin Hall effect through stray field engineering. In our design, a pinned
+magnetic layer is introduced under the heave metal separated by an insulator,
+generating an in-plane stray field in the perpendicularly magnetized layer. We
+have confirmed the deterministic switching of perpendicularly magnetized layers
+through micromagnetic simulation and theoretical analysis. The in-plane stray
+field accounts for the deterministic switching exhibited in the structure and
+the reversal ultimate state of the magnetic layer is predictable when the
+applied spin current density is above the critical spin current density.
+Moreover, the stray field is easily tunable in a wide range by adjusting the
+saturation magnetization and dimensions of the pinned layer, and can
+accommodate different perpendicularly magnetized materials without any external
+magnetic field.",1710.08282v1
+2018-04-02,Magnetism and high-magnetic field magnetization in alkali superoxide CsO2,"Alkali superoxide CsO2 is one of candidates for the spin-1/2 one-dimensional
+(1D) antiferromagnet, which may be sequentially caused by an ordering of the
+pi-orbital of O2- molecule below TS ~ 70 K. Here, we report on the magnetism in
+powder CsO2 and high-magnetic field magnetization measurements in
+pulsed-magnetic fields of up to 60 T. We obtained the low temperature phase
+diagram around the antiferromagnetic ordering temperature TN = 9.6 K under the
+magnetic field. At 1.3 K, remarkable up-turn curvature in the magnetization
+around a saturation field of ~ 60 T is found, which corresponds to the
+spin-1/2. We will compare it with the theoretical calculation.",1804.00377v1
+2019-08-18,Anomalous magnetic behavior and complex magnetic structure of proximate LaCrO3 LaFeO3 system,"We investigated complex magnetic properties of multifunctional LaCrO3-LaFeO3
+system. The magnetic measurements substantiate the presence of competing
+complex magnetic ordering against temperature, showing paramagnetic to
+ferrimagnetic transition at 300 K, followed by antiferromagnetic (AFM)
+transition near 250 K superimposed on ferrimagnetic phase. The onset of weak
+ferrimagnetic ordering is attributed to the competing complex interaction
+between two AFM LaCrO3-LaFeO3 sublattices. The low-temperature AFM ordering is
+also substantiated by temperature-dependent Raman measurements, where the
+intensity ratio of 700 cm-1 Raman active mode showed the clear enhancement with
+lowering the temperature. The non-saturating nature of magnetic moments in
+LaCrO3-LaFeO6 suggests the predominating AFM ordering in conjunction with
+ferrimagnetic ordering between 250 K to 300 K up to 5 T magnetic field. A
+complex magnetic structure of LaCrO3-LaFeO3 is constructed, emphasizing the
+metastable magnetic phase near room temperature and low temperature
+antiferromagnetic state.",1908.06450v1
+2019-08-22,Tunable Birefringence in Silica Mediated Magnetic Fluid,"The present study reports magnetic and optical properties of silica mediated
+lauric acid stabilized magnetic fluids. The tunable birefringence ({\Delta}n)
+and other properties are investigated as a function of (i) concentrations of
+silica suspension, and (ii) saturation magnetization (MS) 0.5099 kA/m (FN30)
+and 1.2855 kA/m (F30) of magnetite magnetic fluid (MF). The study reveals that
+{\Delta}n suppresses on addition of silica in FN30, whereas enhances (up to
+critical concentrations of silica) in F30. The magnetic field induced chain
+observed in the FN30 based fluids are long, thick and scattered, while short,
+thin and dense chains emerges in F30 based fluid. The magnetic field induced
+assembly and the magnetic parameters correlates with the results of {\Delta}n.
+The particle size analysis indicates increment of particle size on addition of
+silica nanoparticles. The thermogravimetry analysis confirms the direct
+interaction of silica nanoparticles and the lauric acid coated magnetite
+particles. This is the first report of direct interaction of silica - magnetite
+magnetic fluids, and its subsequent effect on tunable birefringence and other
+properties.",1908.08366v2
+2021-09-21,Effect of uniaxial single-ion anisotropy on a stability of intermediate magnetization plateaus of a spin-1 Heisenberg diamond cluster,"Ground-state phase diagrams and magnetization curves of a spin-1 Heisenberg
+diamond cluster with two different coupling constants and uniaxial single-ion
+anisotropy are investigated in a presence of the external magnetic field with
+the help of exact diagonalization methods. It is shown that the spin-1
+Heisenberg diamond cluster exhibits several remarkable quantum ground states,
+which are manifested in zero- and low-temperature magnetization curves as
+intermediate plateaus at one-quarter, one-half and three-quarters of the
+saturation magnetization. It is found that the width of the fractional
+magnetization plateaus depends basically on a relative strength of the coupling
+constants as well as uniaxial single-ion anisotropy, which may substantially
+shrink or even cause full breakdown of some intermediate magnetization
+plateaus. It is evidenced that a relatively weak uniaxial single-ion anisotropy
+of the easy-axis type considerably improves a theoretical fit of
+low-temperature magnetization curves of the tetranuclear nickel complex
+[Ni4(CO3)2(aetpy)8](ClO4)4 in a low-field region without spoiling the previous
+fit based on the fully isotropic Heisenberg model in a high-field region.",2109.10030v1
+2021-12-07,Magnetization process of the S=1/2 Heisenberg antiferromagnet on the floret pentagonal lattice,"We study the S=1/2 Heisenberg antiferromagnet on the floret pentagonal
+lattice by numerical diagonalization method. This system shows various
+behaviours that are different from that of the Cairo-pentagonal-lattice
+antiferromagnet. The ground-state energy without magnetic field and the
+magnetization process of this system are reported. Magnetization plateaux
+appear at one-ninth height of the saturation magnetization, at one-third
+height, and at seven-ninth height. The magnetization plateaux at one-third and
+seven-ninth heights come from interactions linking the sixfold-coordinated spin
+sites. A magnetization jump appears from the plateau at one-ninth height to the
+plateau at one-third height. Another magnetization jump is observed between the
+heights corresponding to the one-third and seven-ninth plateaux; however the
+jump is away from the two plateaux, namely, the jump is not accompanied with
+any magnetization plateaux. The jump is a peculiar phenomenon that has not been
+reported.",2112.03516v1
+2022-06-27,Field-Induced Magnetic States in the Metallic Rare-Earth Layered Triangular Antiferromagnet TbAuAl$_4$Ge$_2$,"Magnetic frustration in metallic rare earth lanthanides ($Ln$) with
+$4f$-electrons is crucial for producing interesting magnetic phases with high
+magnetic anisotropy where intertwined charge and spin degrees of freedom lead
+to novel phenomena. Here we report on the magnetic, thermodynamic, and
+electrical transport properties of TbAuAl$_4$Ge$_2$. Tb ions form 2-dimensional
+triangular lattice layers which stack along the crystalline $c$-axis. The
+magnetic phase diagram reveals multiple nearly degenerate ordered states upon
+applying field along the magnetically easy $ab$-plane before saturation. The
+magnetoresistance in this configuration exhibits intricate field dependence
+that closely follows that of the magnetization while the specific heat reveals
+a region of highly enhanced entropy, suggesting the possibility of a
+non-trivial spin textured phase. For fields applied along the $c$-axis (hard
+axis), we find linear magnetoresistance over a wide range of fields. We compare
+the magnetic properties and magnetoresistance with an isostructral
+GdAuAl$_4$Ge$_2$ single crystals. These results identify TbAuAl$_4$Ge$_2$ as an
+environment for complex quantum spin states and pave the way for further
+investigations of the broader $Ln$AuAl$_4$Ge$_2$ family of materials.",2206.13118v1
+2019-05-01,"Evolution of structural, magnetic and transport properties in MnBi2-xSbxTe4","Here we report the evolution of structural, magnetic and transport properties
+in MnBi$_{2-x}$Sb$_x$Te$_4$ (0$\leq x \leq$2) single crystals. MnSb$_2$Te$_4$,
+isostructural to MnBi$_2$Te$_4$, has the lattice parameters of
+\textit{a}=4.2445(3)$\AA$ and \textit{c}=40.869(5)$\AA$, respectively. With
+increasing Sb content in MnBi$_{2-x}$Sb$_x$Te$_4$, the \textit{a}-lattice
+decreases linearly following the Vegards law while the \textit{c}-lattice shows
+little compositional dependence. The \textit{a}-lattice contraction occurs by
+reducing Mn-Te-Mn bond angle while Mn-Te bond length remains nearly constant.
+The anisotropic magnetic properties suggest an antiferromagnetic order below
+T$_N$=19\,K for MnSb$_2$Te$_4$ with the magnetic moments aligned along the
+crystallographic \textit{c}-axis. The antiferromagnetic ordering temperature
+slightly decreases from 24\,K for MnBi$_2$Te$_4$ to 19\,K for MnSb$_2$Te$_4$.
+More dramatic change was observed for the critical magnetic fields required for
+the spin-flop transition and moment saturation. With increasing Sb content,
+both critical fields decrease and in MnSb$_2$Te$_4$ a small field of 3\,kOe is
+enough to saturate the moment. In high magnetic fields, the saturation moment
+shows significant suppression from 3.56$\mu_B$/Mn for MnBi$_2$Te$_4$ to
+1.57$\mu_B$/Mn for MnSb$_2$Te$_4$. Data analyses suggest that both the
+interlayer magnetic interaction and single ion anisotropy decrease with
+increasing Sb content. The partial substitution of Bi by Sb also dramatically
+affects the transport properties. A crossover from n-type to p-type conducting
+behavior is observed around x=0.63. Our results show close correlation between
+structural, magnetic and transport properties in MnBi$_{2-x}$Sb$_x$Te$_4$ and
+that partial substitution of Bi by Sb is an effective approach to fine tuning
+both the magnetism and transport properties of MnBi$_{2-x}$Sb$_x$Te$_4$.",1905.00400v2
+2022-11-19,Nonlinear evolution of magnetorotational instability in a magnetized Taylor-Couette flow: scaling properties and relation to upcoming DRESDYN-MRI experiment,"Magnetorotational instability (MRI) is the most likely mechanism driving
+angular momentum transport in astrophysical disks. However, despite many
+efforts, a conclusive experimental evidence of MRI is still missing. Recently,
+performing 1D linear analysis of the standard MRI (SMRI) in a cylindrical
+Taylor-Couette (TC) flow with an axial magnetic field, we showed that SMRI can
+be detected in the upcoming DRESDYN-MRI experiment based on a magnetized TC
+flow of liquid sodium. In this study, also related to DRESDYN-MRI experiments,
+we focused on the nonlinear evolution and saturation properties of SMRI and
+analyzed its scaling behavior with respect to the main parameters of the TC
+flow. We did a detailed analysis over the extensive ranges of magnetic Reynolds
+number $Rm\in [8.5, 37.1]$, Lundquist number $Lu\in[1.5, 15.5]$ and Reynolds
+number, $Re\in[10^3, 10^5]$. We considered small magnetic Prandtl numbers, $Pm
+\ll 1$, down to $Pm\sim 10^{-4}$, aiming at values typical of liquid sodium in
+the experiments. In the saturated state, the magnetic energy of SMRI and torque
+due to perturbations on the cylinders, which characterizes angular momentum
+transport, both increase with $Rm$ for fixed $(Lu, Re)$, while for fixed $(Lu,
+Rm)$, the magnetic energy decreases and torque increases with increasing $Re$.
+We studied the scaling of the magnetic energy and torque in the saturated state
+as a function of $Re$ and find a power law dependence $Re^{-0.6...-0.5}$ for
+the magnetic energy and $Re^{0.4...0.5}$ for the torque at all $(Lu, Rm)$ and
+high $Re\geq 4000$. We also explored the dependence on Lundquist number and
+angular velocity of the cylinders. These scaling laws will be instrumental in
+the subsequent analysis of more realistic finite-length TC flows and comparison
+of numerical results with those obtained from the DRESDYN-MRI experiments to
+unambiguously identify SMRI in laboratory.",2211.10811v3
+2018-11-29,"Effect of YIG Nanoparticle Size and Clustering in Proximity-Induced Magnetism in Graphene/YIG Composite Probed with Magnetoimpedance Sensors: Towards Improved Functionality, Sensitivity and Proximity Detection","Proximity-induced magnetism (PIM) in graphene (Gr) adjacent to magnetic
+specimen has raised great fundamental interests. The subject is under debate
+and yet no application is proposed and granted. In this paper, toward
+accomplishment of fundamental facts, we first explore the effect of particle
+size and clustering in the PIM in Gr nanoplates (GNPs)/yttrium iron garnet
+(YIG) magnetic nanoparticle (MNP) composite. Microscopic analyzes suggest that
+fine MNPs distributed uniformly on the GNPs have higher saturation
+magnetization due to the PIM in Gr. We propose that such magnetic plates can
+thus be used to shield the stray field generated on the surface of magnetic
+sensors and play a role as a magnetic lens to prevent the field emanating
+outside the body of magnetic specimen. The GNPs/YIG composites are coated on a
+magnetic ribbon and proposed for application in magneto-impedance (MI) sensors.
+We show that such planar magnetic flakes enhance the MI response against the
+external applied magnetic field significantly. The suggested application can be
+furthermore developed toward bio-sensing and magnetic shielding in different
+magnetic sensors and devices.",1811.12317v2
+2020-01-19,Impact of the magnetic proximity effect in Pt on the total magnetic moment of Pt/Co/Ta trilayers studied by x-ray resonant magnetic reflectivity,"In this work, we study the influence of the magnetic proximity effect (MPE)
+in Pt on the total magnetic moment of thin film trilayer systems consisting of
+the ferromagnet (FM) Co adjacent to the heavy metals (HMs) Pt and Ta. We
+investigate the trilayer systems HM1/FM/HM2 with different stacking order as
+well as a reference bilayer without any MPE. X-ray resonant magnetic
+reflectivity (XRMR) is a powerful tool to probe induced magnetism, especially
+when buried at interfaces in a multilayer. By using XRMR, we are able to obtain
+magnetic depth profiles of the structural, optical and magnetic parameters. By
+fitting the experimental data with a Gaussian-like magnetooptic profile taking
+the structural roughness at the interface into account, we can extract the
+magnetic moment of the spin-polarized layer. Comparing the obtained moments to
+the measured total moment of the sample, we can determine the impact of the MPE
+on the total magnetic moment of the system. Such information can be critical
+for analyzing spin transport experiments, including spin-orbit torque and spin
+Hall angle measurements, where the saturation magnetization $M_s$ has to be
+taken into account. Therefore, by combining magnetization measurements and XRMR
+methods we were able to get a complete picture of the magnetic moment
+distribution in these trilayer systems containing spin-polarized Pt.",2001.06857v1
+2021-06-09,Unraveling the role of the magnetic anisotropy on thermoelectric response: a theoretical and experimental approach,"Magnetic anisotropies have key role to taylor magnetic behavior in
+ferromagnetic systems. Further, they are also essential elements to manipulate
+the thermoelectric response in Anomalous Nernst (ANE) and Longitudinal Spin
+Seebeck systems (LSSE). We propose here a theoretical approach and explore the
+role of magnetic anisotropies on the magnetization and thermoelectric response
+of noninteracting multidomain ferromagnetic systems. The magnetic behavior and
+the thermoelectric curves are calculated from a modified Stoner Wohlfarth model
+for an isotropic system, a uniaxial magnetic one, as well as for a system
+having a mixture of uniaxial and cubic magnetocrystalline magnetic
+anisotropies. It is verified remarkable modifications of the magnetic behavior
+with the anisotropy and it is shown that the thermoelectric response is
+strongly affected by these changes. Further, the fingerprints of the energy
+contributions to the thermoelectric response are disclosed. To test the
+robustness of our theoretical approach, we engineer films having the specific
+magnetic properties and compare directly experimental data with theoretical
+results. Thus, experimental evidence is provided to confirm the validity of our
+theoretical approach. The results go beyond the traditional reports focusing on
+magnetically saturated films and show how the thermoelectric effect behaves
+during the whole magnetization curve. Our findings reveal a promising way to
+explore the ANE and LSSE effects as a powerful tool to study magnetic
+anisotropies, as well as to employ systems with magnetic anisotropy as sensing
+or elements in technological applications.",2106.05063v1
+2024-01-24,Magnetic nanoparticles: from the nanostructure to the physical properties,"Some of the synthesis methods and physical properties of iron-oxide based
+magnetic nanoparticles such as Fe3-xO4 and CoxFe3-xO4 are reviewed because of
+their interest in health, environmental applications, and ultra-high-density
+magnetic recording. Unlike high crystalline quality nanoparticles larger than a
+few nanometers that show bulk-like magnetic and electronic properties,
+nanostructures with increasing structural defects yield a progressive worsening
+of their general performance due to frozen magnetic disorder and local breaking
+of their crystalline symmetry. Thus, it is shown that single-crystal,
+monophasic nanoparticles do not exhibit significant surface or finite-size
+effects, such as spin canting, reduced saturation magnetization, high closure
+magnetic fields, hysteresis-loop shift or dead magnetic layer features which
+are mostly associated with crystallographic defective systems. Besides, the key
+role of the nanoparticle coating, surface anisotropy, and inter-particle
+interactions are discussed. Finally, the results of some single particle
+techniques -- magnetic force microscopy, X-ray photoemission electron
+microscopy, and electron magnetic chiral dichroism -- that allow studying
+individual nanoparticles down to sub-nanometer resolution with element, valence
+and magnetic selectivity, are presented. All in all, the intimate, fundamental
+correlation of the nanostructure (crystalline, chemical, magnetic) to the
+physical properties of the nanoparticles is ascertained.",2401.13422v1
+2024-02-26,"Magnetic filaments: formation, stability, and feedback","As well known, magnetic fields in space are distributed very inhomogeneously.
+Some-times field distributions have forms of filaments with high magnetic field
+values. As many ob-servations show, such a filamentation takes place in
+convective cells in the Sun and other astro-physical objects. This effect is
+associated with the frozenness of the magnetic field into a medium with high
+conductivity that leads to compression of magnetic field lines and forming
+magnetic filaments. We show analytically, based on the general analysis, that
+the magnetic field intensifies in the regions of downward flows in both
+two-dimensional and three-dimensional convective cells. These regions of the
+hyperbolic type for magnetic fields play a role of a specific attractor. This
+analysis was confirmed by numerical simulations for 2D convective cells of the
+roll-type. Without dissipation the magnetic field grows exponentially in time
+and does not depend on the aspect ratio between horizontal and vertical scale
+of the cell. An increase due to compression in the magnetic field in the high
+conductive plasma is saturated due to the natural limitation associated with
+dissipative effects when the maximum magnitude of the magnetic field is of the
+order of the root of the magnetic Reynolds number Rem. For the solar convective
+zone the mean kinetic energy density exceeds mean magnetic energy density at
+least for two orders of magnitude that allows one to use the kinematic
+approximation for the MHD induction equation. In this paper based on the
+stability analysis we explain why downward flows influence magnetic filaments
+from making them more flat with orientation along interfaces between convective
+cells.",2402.16989v1
+2002-07-23,A model of nonlinear evolution and saturation of the turbulent MHD dynamo,"The growth and saturation of magnetic field in conducting turbulent media
+with large magnetic Prandtl numbers are investigated. This regime is very
+common in low-density hot astrophysical plasmas. During the early (kinematic)
+stage, weak magnetic fluctuations grow exponentially and concentrate at the
+resistive scale, which lies far below the hydrodynamic viscous scale. The
+evolution becomes nonlinear when the magnetic energy is comparable to the
+kinetic energy of the viscous-scale eddies. A physical picture of the ensuing
+nonlinear evolution of the MHD dynamo is proposed. Phenomenological
+considerations are supplemented with a simple Fokker--Planck model of the
+nonlinear evolution of the magnetic-energy spectrum. It is found that, while
+the shift of the bulk of the magnetic energy from the subviscous scales to the
+velocity scales may be possible, it occurs very slowly -- at the resistive,
+rather than dynamical, time scale (for galaxies, this means that generation of
+large-scale magnetic fields cannot be explained by this mechanism). The role of
+Alfvenic motions and the implications for the fully developed isotropic MHD
+turbulence are discussed.",0207503v2
+2004-08-05,Angular dependent planar metamagnetism in the hexagonal compounds TbPtIn and TmAgGe,"Detailed magnetization measurements, M(T,H,theta), were performed on single
+crystals of TbPtIn and TmAgGe (both members of the hexagonal Fe_2P/ZrNiAl
+structure type), for the magnetic field H applied perpendicular to the
+crystallographic c axis. These data allowed us to identify, for each compound,
+the easy-axes for the magnetization, which coincided with high symmetry
+directions ([120] for TbPtIn and [110] for TmAgGe). For fixed orientations of
+the field along each of the two six-fold symmetry axes, a number of
+magnetically ordered phases is being revealed by M(H,T) measurements below T_N.
+Moreover, T ~ 2 K, M(H)|_theta measurements for both compounds (with H applied
+parallel to the basal plane), as well as T = 20 K data for TbPtIn, reveal five
+metamagnetic transitions with simple angular dependencies: H_{ci,j} ~
+1/cos(theta +/- phi), where phi = 0^0 or 60^0. The high field magnetization
+state varies with theta like 2/3*mu_{sat}(R^{3+})*cos(theta), and corresponds
+to a crystal field limited saturated paramagnetic, CL-SPM, state. Analysis of
+these data allowed us to model the angular dependence of the locally saturated
+magnetizations M_{sat} and critical fields H_c with a three coplanar Ising-like
+model, in which the magnetic moments are assumed to be parallel to three
+adjacent easy axes. Furthermore, net distributions of moments were inferred
+based on the measured data and the proposed model.",0408121v1
+2006-05-18,Mechanisms of degeneracy breaking in pyrochlore antiferromagnets,"Motivated by the low temperature magnetization curves of several spinel
+chromites, we theoretically study classical mechanisms of degeneracy lifting in
+pyrochlore antiferromagnets. Our main focus is on the coupling of spin exchange
+to lattice distortions. Prior work by Penc et al. (Phys. Rev. Lett. 93, 197203
+(2004)) has demonstrated that such coupling leads to a robust magnetization
+plateau at half the saturation moment per spin, in agreement with experiment.
+We show that a simple Einstein model incorporating local site distortions
+generates a ``universal'' magnetic order on the plateau, and highlight the
+distinct predictions of this model from that in Penc et al. (Phys. Rev. Lett.
+93, 197203 (2004)). We also consider the complementary degeneracy-lifting
+effects of further neighbor exchange interactions. We discuss the implications
+for transitions off the plateau at both the high field and low field end, as
+well as at fields close to the saturation value. We predict that under certain
+circumstances there is spontaneous {\sl uniform} XY magnetization (transverse
+to the field) for field values just above the plateau. These features may be
+tested in experiments. While selecting a unique magnetic order in the half
+magnetization plateau, at zero magnetic field the Einstein model retains an
+extensive degeneracy, though significantly reduced compared with the pure
+Heisenberg antiferromagnet.",0605467v1
+2007-05-30,Magnetic turbulence production by streaming cosmic rays upstream of SNR shocks,"We present preliminary results of Particle-In-Cell simulations of magnetic
+turbulence production by isotropic cosmic-ray ions streaming upstream of
+supernova remnant shocks. The studies aim at testing the MHD predictions by
+Bell (2004, 2005) of a strong amplification of short-wavelength nonresonant
+wave modes and at studying the subsequent evolution of the magnetic turbulence
+and its backreaction on cosmic ray trajectories. The detailed knowledge of the
+upstream turbulence properties is crucial to ascertain all aspects of the shock
+acceleration process - the transport properties of cosmic rays, the shock
+structure, thermal particle injection and heating processes. An amplification
+of magnetic field would also facilitate the acceleration of particles beyond
+the ""knee"" in the cosmic-ray spectrum. Our kinetic approach is particularly
+suited to address the backreaction on the cosmic rays, and it allows us to test
+Bell's prediction of the eventual formation of extended filamentary structure
+in the cosmic-ray distribution and also to arrive at a reliable estimate of the
+total saturation magnetic-field level. The parameters chosen for the
+simulations are favorable for the rapid excitation of purely growing modes. We
+confirm the generation of the turbulent magnetic field due to the drift of
+cosmic-ray ions in the upstream plasma, but show that the growth rate of the
+field perturbations is much slower than estimated using the MHD approach and
+the amplitude of the turbulence saturates at about dB/B~1. The magnetic field
+also remains below equipartition with the upstream plasma.",0705.4459v1
+2007-10-16,A generalization of Snoek's law to ferromagnetic films and composites,"The present paper establishes characteristics of the relative magnetic
+permeability spectrum $\mu$(f) of magnetic materials at microwave frequencies.
+The integral of the imaginary part of $\mu$(f) multiplied with the frequency f
+gives remarkable properties. A generalisation of Snoek's law consists in this
+quantity being bounded by the square of the saturation magnetization multiplied
+with a constant. While previous results have been obtained in the case of
+non-conductive materials, this work is a generalization to ferromagnetic
+materials and ferromagnetic-based composites with significant skin effect. The
+influence of truncating the summation to finite upper frequencies is
+investigated, and estimates associated to the finite summation are provided. It
+is established that, in practice, the integral does not depend on the damping
+model under consideration. Numerical experiments are performed in the exactly
+solvable case of ferromagnetic thin films with uniform magnetization, and these
+numerical experiments are found to confirm our theoretical results. Microwave
+permeability measurements on soft amorphous films are reported. The relation
+between the integral and the saturation magnetization is verified
+experimentally, and some practical applications of the theoretical results are
+introduced. The integral can be used to determine the average magnetization
+orientation in materials with complex configurations of the magnetization, and
+furthermore to demonstrate the accuracy of microwave measurement systems. For
+certain applications, such as electromagnetic compatibility or radar absorbing
+materials, the relations established herein provide useful indications for the
+design of efficient materials, and simple figures of merit to compare the
+properties measured on various materials.",0710.2980v2
+2008-12-16,Turbulent dynamos in spherical shell segments of varying geometrical extent,"We use three-dimensional direct numerical simulations of the helically forced
+magnetohydrodynamic equations in spherical shell segments in order to study the
+effects of changes in the geometrical shape and size of the domain on the
+growth and saturation of large-scale magnetic fields. We inject kinetic energy
+along with kinetic helicity in spherical domains via helical forcing using
+Chandrasekhar-Kendall functions. We take perfect conductor boundary conditions
+for the magnetic field to ensure that no magnetic helicity escapes the domain
+boundaries. We find dynamo action giving rise to magnetic fields at scales
+larger than the characteristic scale of the forcing. The magnetic energy
+exceeds the kinetic energy over dissipative time scales, similar to that seen
+earlier in Cartesian simulations in periodic boxes. As we increase the size of
+the domain in the azimuthal direction we find that the nonlinearly saturated
+magnetic field organizes itself in long-lived cellular structures with aspect
+ratios close to unity. These structures tile the domain along the azimuthal
+direction, thus resulting in very small longitudinally averaged magnetic fields
+for large domain sizes. The scales of these structures are determined by the
+smallest scales of the domain, which in our simulations is usually the radial
+scale. We also find that increasing the meridional extent of the domains
+produces little qualitative change, except a marginal increase in the
+large-scale field. We obtain qualitatively similar results in Cartesian domains
+with similar aspect ratios.",0812.3106v2
+2012-09-25,Strong magnetic field effect on above-barrier transport in Pb-p-HgCdTe Schottky barriers,"Due to large difference in effective masses of light and heavy holes it is
+usually supposed that the above-barrier current in Schottky barriers on p-type
+semiconductor is controlled only by the heavy holes. However, in real
+structures, there is an additional potential barrier caused by a oxide layer at
+interface. For typical values of thickness and height of a barrier its tunnel
+transparency for light holes can be higher by three order of magnitude than
+that for heavy holes. Due to such separative role of insulator layer one can
+expect that the current is manly a contribution of light holes. To clear up
+this problem the investigation of transport in a magnetic field is used as a
+key experiment in this work. The pronounced magnetic field effect for heavy
+holes in investigated Pb-p-HgCdTe Schottky barriers is expected only at
+extremely strong magnetic fields B>10 T within the framework of both diode and
+diffusion mechanism of transport. At the same time experimentally more than
+twofold decrease in saturation current is observed even at B=0.5 T at any
+orientation of magnetic field. The studies performed for HgCdTe with different
+Kane's gap and at different temperatures show that the magnitude of magnetic
+field effect is uniquely determined by the ratio of light hole cyclotron energy
+to a thermal energy. However the magnitude of effect exceeds considerably the
+prediction of the simple theory and the experimental magnetic field
+dependencies of a saturation current do not follow the simple exponential
+falling predicted for thermionic current. The reason of this discrepancy
+remains a mystery.",1209.5528v1
+2014-03-11,Non-linear galactic dynamos: A toolbox,"We compare various models and approximations for non-linear mean-field
+dynamos in disc galaxies to assess their applicability and accuracy, and thus
+to suggest a set of simple solutions suitable to model the large-scale galactic
+magnetic fields in various contexts. The dynamo saturation mechanisms
+considered are the magnetic helicity balance involving helicity fluxes (the
+dynamical $\alpha$-quenching) and an algebraic $\alpha$-quenching. The
+non-linear solutions are then compared with the marginal kinematic and
+asymptotic solutions. We also discuss the accuracy of the no-$z$ approximation.
+Although these tools are very different in the degree of approximation and
+hence complexity, they all lead to remarkably similar solutions for the mean
+magnetic field. In particular, we show that the algebraic $\alpha$-quenching
+non-linearity can be obtained from a more physical dynamical $\alpha$-quenching
+model in the limit of nearly azimuthal magnetic field. This suggests, for
+instance, that earlier results on galactic disc dynamos based on the simple
+algebraic non-linearity are likely to be reliable, and that estimates based on
+simple, even linear models are often a good starting point. We suggest improved
+no-$z$ and algebraic $\alpha$-quenching models, and also incorporate galactic
+outflows into a simple analytical dynamo model to show that the outflow can
+produce leading magnetic spirals near the disc surface. The simple dynamo
+models developed are applied to estimate the magnetic pitch angle and the
+arm-interarm contrast in the saturated magnetic field strength for realistic
+parameter values.",1403.2562v2
+2017-10-16,Stellar feedback strongly alters the amplification and morphology of galactic magnetic fields,"Using high-resolution magnetohydrodynamic simulations of idealized,
+non-cosmological galaxies, we investigate how cooling, star formation, and
+stellar feedback affect galactic magnetic fields. We find that the
+amplification histories, saturation values, and morphologies of the magnetic
+fields vary considerably depending on the baryonic physics employed, primarily
+because of differences in the gas density distribution. In particular,
+adiabatic runs and runs with a sub-grid (effective equation of state) stellar
+feedback model yield lower saturation values and morphologies that exhibit
+greater large-scale order compared with runs that adopt explicit stellar
+feedback and runs with cooling and star formation but no feedback. The
+discrepancies mostly lie in gas denser than the galactic average, which
+requires cooling and explicit fragmentation to capture. Independent of the
+baryonic physics included, the magnetic field strength scales with gas density
+as $B\propto n^{2/3}$, suggesting isotropic flux freezing or equipartition
+between the magnetic and gravitational energies during the field amplification.
+We conclude that accurate treatments of cooling, star formation, and stellar
+feedback are crucial for obtaining the correct magnetic field strength and
+morphology in dense gas, which, in turn, is essential for properly modeling
+other physical processes that depend on the magnetic field, such as cosmic ray
+feedback.",1710.05932v1
+2020-01-15,Generation of Solenoidal Modes and Magnetic Fields in Turbulence Driven by Compressive Driving,"We perform numerical simulations of hydrodynamic (HD) and magnetohydrodynamic
+(MHD) turbulence driven by compressive driving to study generation of
+solenoidal velocity component and small-scale magnetic field. We mainly focus
+on the effects of mean magnetic field ($B_0$) and the sonic Mach number
+($M_s$). We also consider two different driving schemes in terms of correlation
+timescale of forcing vectors: a finite-correlated driving and a
+delta-correlated driving. The former has a longer correlation timescale of
+forcing vectors, which is comparable to large-eddy turnover time, than the
+latter. Our findings are as follows. First, when we fix the value of $B_0$, the
+level of solenoidal velocity component after saturation increases as $M_s$
+increases. A similar trend is observed for generation of magnetic field when
+$B_0$ is small. Second, when we fix the value of $M_s$, HD and MHD simulations
+result in similar level of the solenoidal component when $B_0$ $\lesssim$ 0.2
+(or Alfven Mach number of $\sim$ 5). However, the level increases when $B_0$
+$\gtrsim$ 0.2. Roughly speaking, the magnetic energy density after saturation
+is a linearly increasing function of $B_0$ irrespective of $M_s$. Third,
+generation of solenoidal velocity component is not sensitive to numerical
+resolution, but that of magnetic energy density is mildly sensitive. Lastly,
+when initial conditions are same, the finite-correlated driving always produces
+more solenoidal velocity and small-scale magnetic field components than the
+delta-correlated driving. We additionally analyze the vorticity equation to
+understand why higher $M_s$ and $B_0$ yield larger quantity of the solenoidal
+velocity component.",2001.05154v1
+2002-05-22,The Effect of the Hall Term on the Nonlinear Evolution of the Magnetorotational Instability: II. Saturation Level and Critical Magnetic Reynolds Number,"The nonlinear evolution of the magnetorotational instability (MRI) in weakly
+ionized accretion disks, including the effect of the Hall term and ohmic
+dissipation, is investigated using local three-dimensional MHD simulations and
+various initial magnetic field geometries. When the magnetic Reynolds number,
+Re_M \equiv v_A^2 / \eta \Omega (where v_A is the Alfven speed, \eta the
+magnetic diffusivity, and \Omega the angular frequency), is initially larger
+than a critical value Re_{M, crit}, the MRI evolves into MHD turbulence in
+which angular momentum is transported efficiently by the Maxwell stress. If
+Re_M < Re_{M, crit}, however, ohmic dissipation suppresses the MRI, and the
+stress is reduced by several orders of magnitude. The critical value is in the
+range of 1 - 30 depending on the initial field configuration. The Hall effect
+does not modify the critical magnetic Reynolds number by much, but enhances the
+saturation level of the Maxwell stress by a factor of a few. We show that the
+saturation level of the MRI is characterized by v_{Az}^2 / \eta \Omega, where
+v_{Az} is the Alfven speed in the nonlinear regime along the vertical component
+of the field. The condition for turbulence and significant transport is given
+by v_{Az}^2 / \eta \Omega \gtrsim 1, and this critical value is independent of
+the strength and geometry of the magnetic field or the size of the Hall term.
+If the magnetic field strength in an accretion disk can be estimated
+observationally, and the magnetic Reynolds number v_A^2 / \eta \Omega is larger
+than about 30, this would imply the MRI is operating in the disk.",0205383v1
+2008-02-15,Production of Magnetic Turbulence by Cosmic Rays Drifting Upstream of Supernova Remnant Shocks,"We present results of 2D and 3D PIC simulations of magnetic turbulence
+production by isotropic cosmic-ray ions drifting upstream of SNR shocks. The
+studies aim at testing recent predictions of a strong amplification of short
+wavelength magnetic field and at studying the evolution of the magnetic
+turbulence and its backreaction on cosmic rays. We observe that an oblique
+filamentary mode grows more rapidly than the non-resonant parallel modes found
+in analytical theory, and the growth rate of the field perturbations is much
+slower than is estimated for the parallel plane-wave mode, possibly because in
+our simulations we cannot maintain omega << Omega_i, the ion gyrofrequency, to
+the degree required for the plane-wave mode to emerge. The evolved oblique
+filamentary mode was also observed in MHD simulations to dominate in the
+nonlinear phase. We thus confirm the generation of the turbulent magnetic field
+due to the drift of cosmic-ray ions in the upstream plasma, but as our main
+result find that the amplitude of the turbulence saturates at about dB/B~1. The
+backreaction of the turbulence on the particles leads to an alignment of the
+bulk-flow velocities of the cosmic rays and the background medium, which is an
+essential characteristic of cosmic-ray modified shocks. It accounts for the
+saturation of the instability at moderate field amplitudes. Previously
+published MHD simulations have assumed a constant cosmic-ray current and no
+energy or momentum flux in the cosmic rays, which excludes a backreaction of
+the generated magnetic field on cosmic rays, and thus the saturation of the
+field amplitude is artificially suppressed. This may explain the continued
+growth of the magnetic field in the MHD simulations. A strong magnetic field
+amplification to amplitudes dB >> B0 has not been demonstrated yet.",0802.2185v2
+2021-05-25,Simulating radio synchrotron emission in star-forming galaxies: small-scale magnetic dynamo and the origin of the far infrared-radio correlation,"In star-forming galaxies, the far-infrared (FIR) and radio-continuum
+luminosities obey a tight empirical relation over a large range of
+star-formation rates (SFR). We examine magneto-hydrodynamic galaxy simulations
+with cosmic rays (CRs), accounting for their advective and anisotropic
+diffusive transport. We show that gravitational collapse of the proto-galaxy
+generates a corrugated accretion shock, which injects turbulence and drives a
+small-scale magnetic dynamo. As the shock propagates outwards and the
+associated turbulence decays, the large velocity shear between the
+supersonically rotating cool disc with respect to the (partially)
+pressure-supported hot circumgalactic medium excites Kelvin-Helmholtz surface
+and body modes. Those inject turbulence and drive multiple small-scale dynamos,
+which exponentially amplify magnetic fields. They grow in scale to reach
+equipartition with thermal and CR energies in Milky Way-mass galaxies. In small
+galaxies, the magnetic energy saturates at the turbulent energy while it fails
+to reach equipartition with thermal and CR energies. We solve for steady-state
+spectra of CR protons, secondary electrons/positrons from hadronic CR-proton
+interactions with the interstellar medium, and primary shock-accelerated
+electrons at supernovae. The radio-synchrotron emission is dominated by primary
+electrons, irradiates the magnetised disc, bulge, and bubble-shaped
+magnetically-loaded outflows of our simulated Milky Way-mass galaxy. Our
+star-forming and star-bursting galaxies with saturated magnetic fields match
+the global FIR-radio correlation (FRC) across four orders of magnitude. Its
+intrinsic scatter arises due to (i) different magnetic saturation levels that
+result from different seed magnetic fields, (ii) different radio synchrotron
+luminosities for different specific SFRs at fixed SFR and (iii) a varying radio
+intensity with galactic inclination. (abridged)",2105.12132v3
+2016-01-27,Dynamic nuclear polarization in a magnetic resonance force microscope experiment,"We report achieving enhanced nuclear magnetization in a magnetic resonance
+force microscope experiment at 0.6 tesla and 4.2 kelvin using the dynamic
+nuclear polarization (DNP) effect. In our experiments a microwire coplanar
+waveguide delivered radiowaves to excite nuclear spins and microwaves to excite
+electron spins in a 250 nm thick nitroxide-doped polystyrene sample. Both
+electron and proton spin resonance were observed as a change in the mechanical
+resonance frequency of a nearby cantilever having a micron-scale nickel tip.
+NMR signal, not observable from Curie-law magnetization at 0.6 tesla, became
+observable when microwave irradiation was applied to saturate the electron
+spins. The resulting NMR signal's size, buildup time, dependence on microwave
+power, and dependence on irradiation frequency was consistent with a transfer
+of magnetization from electron spins to nuclear spins. Due to the presence of
+an inhomogenous magnetic field introduced by the cantilever's magnetic tip, the
+electron spins in the sample were saturated in a microwave-resonant slice 10's
+of nm thick. The spatial distribution of the nuclear polarization enhancement
+factor $\epsilon$ was mapped by varying the frequency of the applied
+radiowaves. The observed enhancement factor was zero for spins in the center of
+the resonant slice, was $\epsilon = +10$ to $+20$ for spins proximal to the
+magnet, and was $\epsilon = -10$ to $-20$ for spins distal to the magnet. We
+show that this bipolar nuclear magnetization profile is consistent with
+cross-effect DNP in a $\sim \! 10^{5} \: \mathrm{T} \: \mathrm{m}^{-1}$
+magnetic field gradient. Potential challenges associated with generating and
+using DNP-enhanced nuclear magnetization in a nanometer-resolution magnetic
+resonance imaging experiment are elucidated and discussed.",1601.07253v2
+2017-11-23,The evolution of surface magnetic fields in young solar-type stars II: The early main sequence (250-650 Myr),"There is a large change in surface rotation rates of sun-like stars on the
+pre-main sequence and early main sequence. Since these stars have dynamo driven
+magnetic fields, this implies a strong evolution of their magnetic properties
+over this time period. The spin-down of these stars is controlled by
+interactions between stellar winds and magnetic fields, thus magnetic evolution
+in turn plays an important role in rotational evolution. We present here the
+second part of a study investigating the evolution of large-scale surface
+magnetic fields in this critical time period. We observed stars in open
+clusters and stellar associations with known ages between 120 and 650 Myr, and
+used spectropolarimetry and Zeeman Doppler Imaging to characterize their
+large-scale magnetic field strength and geometry. We report 15 stars with
+magnetic detections here. These stars have masses from 0.8 to 0.95 Msun,
+rotation periods from 0.326 to 10.6 days, and we find large-scale magnetic
+field strengths from 8.5 to 195 G with a wide range of geometries. We find a
+clear trend towards decreasing magnetic field strength with age, and a
+power-law decrease in magnetic field strength with Rossby number. There is some
+tentative evidence for saturation of the large-scale magnetic field strength at
+Rossby numbers below 0.1, although the saturation point is not yet well
+defined. Comparing to younger classical T Tauri stars, we support the
+hypothesis that differences in internal structure produce large differences in
+observed magnetic fields, however for weak lined T Tauri stars this is less
+clear.",1711.08636v1
+2020-12-14,A nonlinear solar magnetic field calibration method for the filter-based magnetograph by the residual network,"The method of solar magnetic field calibration for the filter-based
+magnetograph is normally the linear calibration method under weak-field
+approximation that cannot generate the strong magnetic field region well due to
+the magnetic saturation effect. We try to provide a new method to carry out the
+nonlinear magnetic calibration with the help of neural networks to obtain more
+accurate magnetic fields. We employed the data from Hinode/SP to construct a
+training, validation and test dataset. The narrow-band Stokes I, Q, U, and V
+maps at one wavelength point were selected from all the 112 wavelength points
+observed by SP so as to simulate the single-wavelength observations of the
+filter-based magnetograph. We used the residual network to model the nonlinear
+relationship between the Stokes maps and the vector magnetic fields. After an
+extensive performance analysis, it is found that the trained models could infer
+the longitudinal magnetic flux density, the transverse magnetic flux density,
+and the azimuth angle from the narrow-band Stokes maps with a precision
+comparable to the inversion results using 112 wavelength points. Moreover, the
+maps that were produced are much cleaner than the inversion results. The method
+can effectively overcome the magnetic saturation effect and infer the strong
+magnetic region much better than the linear calibration method. The residual
+errors of test samples to standard data are mostly about 50 G for both the
+longitudinal and transverse magnetic flux density. The values are about 100 G
+with our previous method of multilayer perceptron, indicating that the new
+method is more accurate in magnetic calibration.",2012.07286v1
+2011-07-26,Magnetic Behaviour of Disordered Ising Ferrimagnet in High Magnetic Field,"The magnetic behaviour of a disordered ferrimagnetic system Ap B1-p where
+both A and B represent the magnetic atoms with respective spin SA = 1/2 and SB
+= 1 in presence of high magnetic field is treated theoretically.Assuming the
+magnetic interaction can be described through Ising Hamiltonian the approximate
+free energy is obtained using the cluster-variational method. The field
+dependence of the magnetization is then obtained for different concentration p
+and exchange parameters (JAA, JBB and JAB). For p = 0.5,the magnetization M in
+ferrimagnetic state and in absence of compensation temperature Tcm vanishes at
+TC.Field induced reversal of M is found at switching temperature TS (<TC) which
+is decreasing function of field H.A maximum in M is found above TS and the
+maximum value of M increases with field.In ferrimagnetic state M increases
+almost linearly at high H region. For system with large ferromagnetic JAA,the
+compensation temperature Tcm is increasing function of JBB and JAB .The
+decrease in compensation temperature is linear at small field and tends to
+saturate at higher field.The sharpness of the magnetization reversal is
+increased with H.For fully compensated state of the system with p = 2/3,the
+magnetization in presence of H also exhibits switching behaviour at TS .For p =
+0.2 the field induced reversal of magnetization occurs more sharply.The
+orientational switching of the sublattice magnetization MA and MB with field
+increases the Zeeman energy and is the origin of magnetization reversal at Ts",1107.5225v1
+2013-11-23,Universal Scaling Law to Predict the Efficiency of Magnetic Nanoparticles as MRI T2-Contrast Agents,"Magnetic particles are very efficient Magnetic Resonance Imaging (MRI)
+contrast agents. In the recent years, chemists have unleashed their imagination
+to design multi-functional nanoprobes for biomedical applications including MRI
+contrast enhancement. This study is focused on the direct relationship between
+the size and magnetization of the particles and their nuclear magnetic
+resonance relaxation properties, which condition their efficiency. Experimental
+relaxation results with maghemite particles exhibiting a wide range of sizes
+and magnetizations are compared to previously published data and to
+well-established relaxation theories with a good agreement. This allows
+deriving the experimental master curve of the transverse relaxivity versus
+particle size and to predict the MRI contrast efficiency of any type of
+magnetic nanoparticles. This prediction only requires the knowledge of the size
+of the particles impermeable to water protons and the saturation magnetization
+of the corresponding volume. To predict the T2 relaxation efficiency of
+magnetic single crystals, the crystal size and magnetization obtained through a
+single Langevin fit of a magnetization curve is the only information needed.
+For contrast agents made of several magnetic cores assembled into various
+geometries (dilute fractal aggregates, dense spherical clusters, core-shell
+micelles, hollow vesicles), one needs to know a third parameter, namely the
+intra-aggregate volume fraction occupied by the magnetic materials relatively
+to the whole (hydrodynamic) sphere. Finally a calculation of the maximum
+achievable relaxation effect and the size needed to reach this maximum is
+performed for different cases: maghemite single crystals and dense clusters,
+core-shell particles (oxide layer around a metallic core) and zinc manganese
+ferrite crystals.",1311.6022v1
+2013-12-09,High magnetic field evolution of ferroelectricity in CuCrO2,"CuCrO2 offers insights into the different types of spiral magnetic orderings
+that can form spontaneously due to frustration in triangular-lattice
+antiferromagnets. We explore the magnetic phase diagram up to 65 T along all
+the principle axes, and also use electric polarization to probe changes in the
+spiral order at high magnetic fields. It is known that at zero magnetic field a
+proper-screw spiral of the Cr S = 3/2 spins forms that in turn induces electric
+polarization with six possible orientations ab-plane. Applied magnetic fields
+in the (hard) ab-plane have been shown to induce a transition to cycloidal
+spiral magnetic order above 5.3 T in those domains that have spins
+perpendicular to the applied magnetic field. We show that the cycloidal order
+remains unchanged all the way up to 65 T, which is one quarter of the
+extrapolated saturation magnetization. On the other hand for magnetic fields
+along the (easy) c-axis, we observe a transition in the electric polarization
+near 45 T, and it is followed by a series of steps and/or oscillations in the
+electric polarization. The data is consistent with the a
+proper-screw-to-cycloidal transition that is pushed from 5.3 to 45 T by
+easy-axis anisotropy, and is in turn followed by stretching of the magnetic
+spiral through commensurate and incommensurate wave vectors. This work also
+highlights the ability of the magnetically-induced electric polarization to
+probe complex magnetic orders in regimes of phase space that are difficult to
+reach with neutron diffraction.",1312.2548v1
+2020-09-28,Magnetic domains and domain wall pinning in two-dimensional ferromagnets revealed by nanoscale imaging,"Magnetic-domain structure and dynamics play an important role in
+understanding and controlling the magnetic properties of two-dimensional
+magnets, which are of interest to both fundamental studies and
+applications[1-5]. However, the probe methods based on the spin-dependent
+optical permeability[1,2,6] and electrical conductivity[7-10] can neither
+provide quantitative information of the magnetization nor achieve nanoscale
+spatial resolution. These capabilities are essential to image and understand
+the rich properties of magnetic domains. Here, we employ cryogenic scanning
+magnetometry using a single-electron spin of a nitrogen-vacancy center in a
+diamond probe to unambiguously prove the existence of magnetic domains and
+study their dynamics in atomically thin CrBr$_3$. The high spatial resolution
+of this technique enables imaging of magnetic domains and allows to resolve
+domain walls pinned by defects. By controlling the magnetic domain evolution as
+a function of magnetic field, we find that the pinning effect is a dominant
+coercivity mechanism with a saturation magnetization of about 26~$\mu_B$/nm$^2$
+for bilayer CrBr$_3$. The magnetic-domain structure and pinning-effect
+dominated domain reversal process are verified by micromagnetic simulation. Our
+work highlights scanning nitrogen-vacancy center magnetometry as a quantitative
+probe to explore two-dimensional magnetism at the nanoscale.",2009.13440v1
+2022-05-02,Computational Study of Magnetic Switching Mechanism and Magnetoresistive Behaviour of Nanoscale Spin Valve Elements,"Investigation of the magnetic switching and magnetoresistive behaviour of
+nanoscale spin valve elements of different sizes, shapes and arrays is of vital
+importance for their application in future magnetic memory and storage devices.
+To this end, we have inspected the magnetic switching mechanism and
+magnetoresistive behaviour of nanoscale spin valve (Co/Cu/Ni80Fe20) elements of
+two different shapes with varying lateral aspect ratios (ARs) by computational
+micromagnetic simulation. Further, we have inspected the same for 2x2 and 3x3
+arrays of the elliptical elements with AR = 1.25 of varying interelement
+spacing. We have analysed how the shape of the hysteresis loop and its various
+parameters such as the coercive field, remanence, saturation field were altered
+by the variation in magnetic field. The magnetization reversal states were
+simulated to explore the spatial coherence of magnetization switching. We
+observe that the elements with higher AR show the Ni80Fe20 and Co layers
+forming antiparallel states in the plateau similar to synthetic
+antiferromagnets. As we reduce the AR, more complex quasi-uniform magnetic
+states are observed which are even more complicated for elliptical elements.
+The elliptical elements with the aspect ratio of 1.25 shows coherent and
+predictable switching behaviour, showing its suitability for the application in
+magnetic memory elements. We observe a gradual increase in magnetoresistance
+(MR%) with the increase in AR of the spin valve elements, and the decrease in
+interelement spacing between the spin valve elements in their arrays. The
+magnetic flux density decreases, as we increase the cell spacing between the
+elements. The magnetic hysteresis loops, magnetoresistance and spatial
+coherence of magnetic switching give a guiding principle for selection of
+geometric parameters of nanoscale spin valve arrays towards their application
+in magnetic memory devices.",2205.00739v1
+2023-03-01,Proton-fluence dependent magnetic properties of exfoliable quasi-2D van der Waals Cr2Si2Te6 magnet,"The discovery of long-range magnetic ordering in atomically thin materials
+catapulted the van der Waals (vdW) family of compounds into an unprecedented
+popularity. In particular, with a current push in space exploration, it is
+beneficial to study how the properties of such materials evolve under proton
+irradiation. Owing to their robust intra-layer stability and sensitivity to
+external perturbations, these materials provide excellent opportunities for
+studying proton irradiation as a non-destructive tool for controlling their
+magnetic properties. Specifically, the exfoliable Cr2Si2Te6 (CST) is a
+ferromagnetic semiconductor with the Curie temperature (TC) of ~32 K. Here, we
+have investigated the magnetic properties of CST upon proton irradiation as a
+function of fluence (1 x 1015, 5 x 1015, 1 x 1016, 5 x 1016, and 1 x 1018
+H+/cm2) by employing variable-temperature, variable-field magnetization
+measurements coupled with electron paramagnetic resonance (EPR) spectroscopy
+and detail how the magnetization, magnetic anisotropy and EPR spectral
+parameters vary as a function of proton fluence across the magnetic phase
+transition. While the TC remains constant as a function of proton fluence, we
+observed that the saturation magnetization and magnetic anisotropy diverge at
+the proton fluence of 5 x 1016 H+/cm2, which is prominent in the ferromagnetic
+phase, in particular. This work demonstrates that proton irradiation is a
+feasible method for modifying the magnetic properties and local magnetic
+interactions of vdWs crystals, which represents a significant step forward in
+the design of future spintronic and magneto-electronic applications.",2303.00824v1
+2023-12-14,Nanoscale magnetism and magnetic phase transitions in atomically thin CrSBr,"Since their first observation in 2017, atomically thin van der Waals (vdW)
+magnets have attracted significant fundamental, and application-driven
+attention. However, their low ordering temperatures, $T_c$, sensitivity to
+atmospheric conditions and difficulties in preparing clean large-area samples
+still present major limitations to further progress. The remarkably stable
+high-$T_c$ vdW magnet CrSBr has the potential to overcome these key
+shortcomings, but its nanoscale properties and rich magnetic phase diagram
+remain poorly understood. Here we use single spin magnetometry to
+quantitatively characterise saturation magnetization, magnetic anisotropy
+constants, and magnetic phase transitions in few-layer CrSBr by direct magnetic
+imaging. We show pristine magnetic phases, devoid of defects on micron
+length-scales, and demonstrate remarkable air-stability down the monolayer
+limit. We address the spin-flip transition in bilayer CrSBr by direct imaging
+of the emerging antiferromagnetic (AFM) to ferromagnetic (FM) phase wall and
+elucidate the magnetic properties of CrSBr around its ordering temperature. Our
+work will enable the engineering of exotic electronic and magnetic phases in
+CrSBr and the realisation of novel nanomagnetic devices based on this highly
+promising vdW magnet.",2312.09279v1
+2001-05-28,Nonlinear States of the Screw Dynamo,"The self-excitation of magnetic field by a spiral Couette flow between two
+coaxial cylinders is considered. We solve numerically the fully nonlinear,
+three-dimensional MHD equations for magnetic Prandtl numbers Pm (ratio of
+kinematic viscosity to magnetic diffusivity) between 0.14 and 10 and kinematic
+and magnetic Reynolds numbers up to about 2000. In the initial stage of
+exponential field growth (kinematic dynamo regime), we find that the dynamo
+switches from one distinct regime to another as the radial width \delta r_B$ of
+the magnetic field distribution becomes smaller than the separation of the
+field maximum from the flow boundary. The saturation of magnetic field growth
+is due to a reduction in the velocity shear resulting mainly from the
+azimuthally and axially averaged part of the Lorentz force, which agrees with
+an asymptotic result for the limit of Pm<<1. In the parameter regime
+considered, the magnetic energy decreases with kinematic Reynolds number as
+Re^{-0.84}, which is approximately as predicted by the nonlinear asymptotic
+theory (\sim Re^{-1}). However, when the velocity field is maintained by a
+volume force (rather than by viscous stress) the dependence of magnetic energy
+on the kinematic Reynolds number is much weaker.",0105484v2
+2002-02-01,Dipole coupling induced magnetic ordering in an ensemble of nanostructured islands,"The magnetic ordering due to the long range dipole coupling in an ensemble of
+magnetic islands is investigated. If the islands are large enough and closely
+separated, the average dipole energy per island can explain the magnitude of
+the observed ordering temperature of such an ensemble. The energetical
+degeneracy with respect to a continuous in-plane rotation of the magnetic
+moments in a periodic ensemble of islands is lifted in presence of an island
+size dispersion and an irregular island array. Many different (metastable)
+magnetic states are obtained, reminiscent of a spin-glass behavior. We obtain
+that the average magnetic binding energy per island due to the dipole coupling
+increases with increasing positional disorder. The island ensembles exhibit
+non-collinear magnetic structures, resulting in non-saturated ensemble
+magnetizations. The calculations are performed with a classical spin model for
+ensembles of islands in unit cells with periodic boundary conditions. The point
+dipole sums are augmented by an island areal correction.",0202013v1
+2002-10-11,Quasi two-dimensional antiferromagnet on a triangular lattice RbFe(MoO4)2,"RbFe(MoO4)2 is a rare example of a nearly two-dimensional Heisenberg
+antiferromagnet on a triangular lattice. Magnetic resonance spectra and
+magnetization curves reveal that the system has a layered spin structure with
+six magnetic sublattices. The sublattices within a layer are arranged in a
+triangular manner with the magnetization vectors 120 degree apart. The H-T
+phase diagram, containing at least five different magnetic phases is
+constructed. In zero field, RbFe(MoO4)2 undergoes a phase transition at T_N=3.8
+K into a non-collinear triangular spin structure with all the spins confined in
+the basal plane. The application of an in-plane magnetic field induces a
+collinear spin state between the fields H_c1=47 kOe and H_c2=71 kOe and
+produces a magnetization plateau at one-third of the saturation moment. Both
+the ESR and the magnetization measurements also clearly indicate an additional
+first-order phase transition in a field of 35 kOe. The exact nature of this
+phase transition is uncertain.",0210262v1
+2002-12-18,Coexistence of ferro- and antiferromagnetic order in Mn-doped Ni$_2$MnGa,"Ni-Mn-Ga is interesting as a prototype of a magnetic shape-memory alloy
+showing large magnetic field induced strains. We present here results for the
+magnetic ordering of Mn-rich Ni-Mn-Ga alloys based on both experiments and
+theory. Experimental trends for the composition dependence of the magnetization
+are measured by a vibrating sample magnetometer (VSM) in magnetic fields of up
+to several tesla and at low temperatures. The saturation magnetization has a
+maximum near the stoichiometric composition and it decreases with increasing Mn
+content. This unexpected behaviour is interpreted via first-principles
+calculations within the density-functional theory. We show that extra Mn atoms
+are antiferromagnetically aligned to the other moments, which explains the
+dependence of the magnetization on composition. In addition, the effect of Mn
+doping on the stabilization of the structural phases and on the magnetic
+anisotropy energy is demonstrated.",0212442v1
+2003-04-09,Field-induced magnetic anisotropy in La0.7Sr0.3CoO3,"Magnetic anisotropy has been measured for the ferromagnetic La0.7Sr0.3CoO3
+perovskite from an analysis of the high-field part of the magnetization vs.
+field curves, i.e., the magnetic saturation regime. These measurements give a
+magnetic anistropy one order of magnitude higher than that of reference
+manganites. Surprisingly, the values of the magnetic anisotropy calculated in
+this way do not coincide with those estimated from measurements of coercive
+fields which are one order of magnitude smaller. It is proposed that the reason
+of this anomalous behaviour is a transition of the trivalent Co ions under the
+external magnetic field from a low-spin to an intermediate-spin state. Such a
+transition converts the Co3+ ions into Jahn-Teller ions having an only
+partially quenched orbital angular momentum, which enhances the intra-atomic
+spin-orbit coupling and magnetic anisotropy.",0304211v1
+2006-03-22,"Out-of-plane magnetization reversal processes of (Ga,Mn)As with two different hole concentrations","We study magnetization reversal processes of in-plane magnetized (Ga,Mn)As
+epilayers with different hole concentrations in out-of-plane magnetic fields
+using magnetotransport measurements. A clear difference in the magnetization
+process is found in two separate samples with hole concentrations of 10^20
+cm^-3 and 10^21 cm^-3 as the magnetization rotates from the out-of-plane
+saturation to the in-plane remanence. Magnetization switching process from the
+in-plane remanence to the out-of-plane direction, on the other hand, shows no
+hole concentration dependence, where the switching process occurs via domain
+wall propagation. We show that the balance of <100> cubic magnetocrystalline
+anisotropy and uniaxial [110] anisotropy gives an understanding of the
+difference in the out-of-plane magnetization processes of (Ga,Mn)As epilayers.",0603568v1
+2009-12-17,How Gold nanoparticle acquires magnetism? - Formation of large orbital moment at the interface,"In this paper, we have tried to find out the origin of magnetism in Gold
+nanoparticles (Au- NPs). We observe that upon incorporating Gold nanoparticles
+(Au-NPs) in Fe3O4 nanoparticle medium the net magnetisation increases compared
+to the pure Fe3O4 nanoparticle medium. This increase of magnetization can be
+attributed to the large orbital magnetic moment formation at the Au/magnetic
+particle interface indicating that magnetism observed in Au-NPs is an
+interfacial effect. This interfacial effect has been supported by the
+observation of sudden transition from positive saturated magnetisation to a
+negative diamagnetic contribution as a function of magnetic field on citrate
+coated gold Au-NPs.",0912.3319v2
+2011-01-30,Titanium pyrochlore magnets: how much can be learned from magnetization measurements?,"We report magnetization data for several titanium pyrochlore systems measured
+down to 0.5 K. The measurements, performed on single crystal samples in fields
+of up to 7 T, have captured the essential elements of the previously reported
+phase transitions in these compounds and have also revealed additional
+important features overlooked previously either because of the insufficiently
+low temperatures used, or due to limitations imposed by polycrystalline
+samples. For the spin-ice pyrochlores Dy2Ti2O7 and Ho2Ti2O7, an unusually slow
+relaxation of the magnetization has been observed in lower fields, while the
+magnetization process in higher fields is essentially hysteresis-free and does
+not depend on sample history. For the XY pyrochlore Er2Ti2O7, the magnetic
+susceptibility shows nearly diverging behaviour on approach to a critical
+field, HC = 13.5 kOe, above which the magnetization does not saturate but
+continues to grow at a significant rate. For the Heisenberg pyrochlore
+Gd2Ti2O7, the magnetic susceptibility shows a pronounced change of slope at
+both transition temperatures, TN1 = 1.02 K and TN2 = 0.74 K, contrary to the
+earlier reports.",1101.5812v1
+2011-07-01,"Magnetic model for A2CuP2O7 (A = Na, Li) revisited: 1D versus 2D behavior","We report magnetization measurements, full-potential band structure
+calculations, and microscopic modeling for the spin-1/2 Heisenberg magnets
+A2CuP2O7 (A = Na, Li). Based on a quantitative evaluation of the leading
+exchange integrals and the subsequent quantum Monte-Carlo simulations, we
+propose a quasi-one-dimensional magnetic model for both compounds, in contrast
+to earlier studies that conjectured on the two-dimensional scenario. The
+one-dimensional nature of A2CuP2O7 is unambiguously verified by magnetization
+isotherms measured in fields up to 50 T. The saturation fields of about 40 T
+for both Li and Na compounds are in excellent agreement with the intrachain
+exchange J1 ~ 27 K extracted from the magnetic susceptibility data. The
+proposed magnetic structure entails spin chains with the dominating
+antiferromagnetic nearest-neighbor interaction J1 and two inequivalent,
+nonfrustrated antiferromagnetic interchain couplings of about 0.01*J1 each. A
+possible long-range magnetic ordering is discussed in comparison with the
+available experimental information.",1107.0250v3
+2012-06-25,Modification of structural and magnetic properties of Zn0.96 Mn0.04O samples by Li3+ ion irradiation,"Zn0.96Mn0.04O samples were synthesized by solid state reaction technique to
+explore their magnetic behavior. Structural, morphological and magnetic
+properties of the samples have been found to be modified by 50 MeV Li+3 ion
+beam irradiation. The samples exhibit impurity phase and upon irradiation it
+disappears. Rietveld refinement analysis indicates that substitutional
+incorporation of Mn in the host lattice increases with irradiation. Grain size
+decreases with irradiation. Field dependent magnetization (M-H) measurement
+explicitly indicates ferromagnetic (FM) nature. It has been established from
+temperature dependent magnetization (M-T) measurement (500 Oe) and ac
+susceptibility (\chi-T) measurement that ferromagnetism in the system seems to
+be mainly intrinsic; though superparamagnetic Mn nanoparticles also has a minor
+role. The analysis of M-T data at comparatively high field (5000-Oe) provides
+an estimation of antiferromagnetic (AFM) exchange, which acts as a reducing
+agent for observed magnetic moment. The value of saturation magnetization has
+been increased upon irradiation and is highly correlated with dissolution of
+impurity phase. Actually structural property has been modified with ion
+irradiation and this modification may cause some definite positive change in
+magnetic property.",1206.5619v1
+2012-07-12,Ground States of the Ising Model on the Shastry-Sutherland Lattice and the Origin of the Fractional Magnetization Plateaus in Rare-Earth Tetraborides,"A complete and exact solution of the ground-state problem for the Ising model
+on the Shastry-Sutherland lattice in the applied magnetic field is found. The
+magnetization plateau at the one third of the saturation value is shown to be
+the only possible fractional plateau in this model. However, stripe magnetic
+structures with magnetization 1/2 and $1/n$ ($n > 3$), observed in the
+rare-earth tetraborides RB$_4$, occur at the boundaries of the
+three-dimensional regions of the ground-state phase diagram. These structures
+give rise to new magnetization plateaus if interactions of longer ranges are
+taken into account. For instance, an additional third-neighbor interaction is
+shown to produce a 1/2 plateau. The results obtained significantly refine the
+understanding of the magnetization process in RB$_4$ compounds, especially in
+TmB$_4$ and ErB$_4$ which are strong Ising magnets.",1207.3030v1
+2013-03-21,Magnetization Process and Collective Excitations in the S=1/2 Triangular-Lattice Heisenberg Antiferromagnet Ba3CoSb2O9,"We have performed high-field magnetization and ESR measurements on
+Ba$_3$CoSb$_2$O$_9$ single crystals, as a representative two-dimensional
+spin-1/2 Heisenberg antiferromagnet on a uniform triangular lattice, and have
+determined all the magnetic parameters. For an applied magnetic field $H$
+parallel to the $ab$-plane, the entire magnetization curve including the
+plateau at one-third of the saturation magnetization ($M_\mathrm{s}$) is in
+excellent agreement with the results of theoretical calculations except an
+anomaly near $(3/5)M_\mathrm{s}$, indicative of an additional field-induced
+transition. However, for $H\,{\parallel}\,c$, the magnetization curve exhibits
+a cusp near $M_\mathrm{s}/3$. Paramagnetic resonance signals above the N\'eel
+temperature indicate the nearly isotropic $g$-factor. A detailed analysis of
+the collective ESR modes observed in the ordered state, combined with the
+magnetization process, provides evidence of the weak easy-plane anisotropy.",1303.5271v3
+2013-04-14,Influence of initial conditions on the large-scale dynamo growth rate,"To investigate the effect of energy and helicity on the growth of magnetic
+field, helical kinetic forcing was applied to the magnetohydrodynamic(MHD)
+system that had a specific distribution of energy and helicity as initial
+conditions. Simulation results show the saturation of a system is not
+influenced by the initial conditions, but the growth rate of large scale
+magnetic field is proportionally dependent on the initial large scale magnetic
+energy and helicity. It is already known that the helical component of small
+scale magnetic field(i.e., current helicity $<{\bf j}\cdot {\bf b}>$) quenches
+the growth of large scale magnetic field. However, $<{\bf j}\cdot {\bf b}>$ can
+also boost the growth of large scale magnetic field by changing its sign and
+magnitude. In addition, simulation shows the nonhelical magnetic field can
+suppress the velocity field through Lorentz force. Comparison of the profiles
+of evolving magnetic and kinetic energy indicates that kinetic energy migrates
+backward when the external energy flows into the three dimensional MHD system,
+which means the velocity field may play a preceding role in the very early MHD
+dynamo stage.",1304.3870v3
+2013-07-14,In-plane and out of plane magnetic properties in Ni46Co4Mn38Sb12 Heusler alloys ribbons,"Magnetic, magnetocaloric and exchange bias properties have been
+systematically investigated in Ni46Co4Mn38Sb12 ribbon by applying magnetic
+field along (IP) and perpendicular (OP) to the ribbon plane. From the
+thermo-magnetization curves, the sharpness of the martensitic transition is
+observed to be nearly the same for both IP and OP ribbons. The thermomagnetic
+irreversibility region is found to be larger in the OP ribbon at 500 Oe,
+indicating that the magnetic anisotropy is larger in this case. The OP ribbon
+shows the Hopkinson maximum at 500 Oe, both for the FCC and ZFC modes. The
+magnetization curve for IP ribbon shows a faster approach to saturation,
+compared to the OP ribbon. Isothermal magnetic entropy change at 50 kOe has
+been found to be nearly same for both the ribbons. At 5 K the coercivity and
+exchange bias values are larger for the OP ribbon. Crystallographic texturing
+of the ribbons and its effect in the easy magnetization direction are found to
+be the reason behind the differences between the two ribbons.",1307.3778v1
+2013-11-21,Magnetization Enhancement in Magnetite Nanoparticles Capped with Alginic Acid,"We report on the effect of organic acid capping on the behavior of magnetite
+nanoparticles. The nanoparticles of magnetite were obtained using microwave
+activated process, and the magnetic properties as well as the electron magnetic
+resonance behavior were studied for the Fe3O4 nanoparticles capped with alginic
+acid. The capped nanoparticles exhibit improved crystalline structure of the
+surface which leads to an enhanced magnetization. The saturation magnetization
+Ms increases to ~75% of the bulk magnetization. The improved structure also
+facilitates quantization of spin-wave spectrum in the finite size nanoparticles
+and this in turn is responsible for unconventional behavior at low
+temperatures. In magnetic resonance these anomalies are manifested as an
+unusual increase in the resonant field Hr(T) and also as a maximum of the
+spectroscopic splitting geff parameter at low temperatures. The unconventional
+behavior of the nanoparticles also leads to pronounced upturn of magnetization
+at low temperatures and a deviation from the Bloch law M(T) T^3/2.",1311.5379v1
+2014-02-27,Universal logarithmic temperature dependence of magnetic susceptibility of one-dimensional electrons at critical values of magnetic field,"We study the leading low temperature dependence of magnetic susceptibility of
+one-dimensional electrons with fixed total number of particles at the magnetic
+fields equal to zero temperature critical values where magnetic field induces
+commensurate-incommensurate quantum phase transitions. For free and repulsively
+interacting electrons there is only one such critical field corresponding to
+the transition to the fully polarized state. For attractively interacting
+electrons besides saturation field there is another critical field equal to the
+spin gap where zero temperature magnetization sets in. For all cases, except of
+the lattice models at half filling, the magnetic susceptibility at critical
+values of magnetic field has a universal logarithmic temperature
+dependence,x(T)=x(0)(1+2/Log(T)+...) for T -> 0.",1402.6801v1
+2014-04-29,Nanowire Spin Torque Oscillator Driven by Spin Orbit Torques,"Spin torque from spin current applied to a nanoscale region of a ferromagnet
+can act as negative magnetic damping and thereby excite self-oscillations of
+its magnetization. In contrast, spin torque uniformly applied to the
+magnetization of an extended ferromagnetic film does not generate
+self-oscillatory magnetic dynamics but leads to reduction of the saturation
+magnetization. Here we report studies of the effect of spin torque on a system
+of intermediate dimensionality - a ferromagnetic nanowire. We observe coherent
+self-oscillations of magnetization in a ferromagnetic nanowire serving as the
+active region of a spin torque oscillator driven by spin orbit torques. Our
+work demonstrates that magnetization self-oscillations can be excited in a
+one-dimensional magnetic system and that dimensions of the active region of
+spin torque oscillators can be extended beyond the nanometer length scale.",1404.7262v2
+2014-06-08,Perpendicular magnetic anisotropy and magnetization process in CoFeB/Pd multilayer films,"Perpendicular magnetic anisotropy (PMA) and dynamic magnetization reversal
+process in [CoFeB $t$ nm/Pd 1.0 nm]$_n$ ($t$ = 0.4, 0.6, 0.8, 1.0, and 1.2 nm;
+$n$ = 2 - 20) multilayer films have been studied by means of magnetic
+hysteresis and Kerr effect measurements. Strong and controllable PMA with an
+effective uniaxial anisotropy up to 7.7$\times$ 10$^6$ J.m$^{-3}$ and a
+saturation magnetization as low as 200 emu/cc are achieved. Surface/interfacial
+anisotropy of CoFeB/Pd interfaces, the main contribution to the PMA, is
+separated from the effective uniaxial anisotropy of the films, and appears to
+increase with the number of the CoFeB/Pd bilayers. Observation of the magnetic
+domains during a magnetization reversal process using polar magneto-optical
+Kerr microscopy shows the detailed behavior of nucleation and displacement of
+the domain walls.",1406.2028v1
+2016-01-06,Strain-assisted magnetization reversal in Co/Ni multilayers with perpendicular magnetic anisotropy,"Multifunctional materials composed of ultrathin magnetic films with
+perpendicular magnetic anisotropy combined with ferroelectric substrates
+represent a new approach toward low power, fast, high density spintronics. Here
+we demonstrate Co/Ni multilayered films with tunable saturation magnetization
+and perpendicular anisotropy grown directly on ferroelectric PZT
+[Pb(Zr_xTi_1-x)O_3] substrate plates. Electric fields up to +/- 2 MV/m expand
+the PZT by 0.1% and generate at least 0.02% in-plane compression in the Co/Ni
+multilayered film. Modifying the strain with a voltage can reduce the coercive
+field by over 30%. We also demonstrate that alternating in-plane tensile and
+compressive strains (less than 0.01%) can be used to propagate magnetic domain
+walls. This ability to manipulate high anisotropy magnetic thin films could
+prove useful for lowering the switching energy for magnetic elements in future
+voltage-controlled spintronic devices.",1601.01349v1
+2018-01-31,The Heisenberg spin-1/2 XXZ chain in the presence of electric and magnetic fields,"We study the interplay of electric and magnetic order in the one dimensional
+Heisenberg spin-1/2 XXZ chain with large Ising anisotropy in the presence of
+the Dzyaloshinskii-Moriya (D-M) interaction and with longitudinal and
+transverse magnetic fields, interpreting the D-M interaction as a coupling
+between the local electric polarization and an external electric field. We
+obtain the ground state phase diagram using the density matrix renormalization
+group method and compute various ground state quantities like the
+magnetization, staggered magnetization, electric polarization and spin
+correlation functions, etc. In the presence of both longitudinal and transverse
+magnetic fields, there are three different phases corresponding to a gapped
+N\'{e}el phase with antiferromagnetic (AF) order, gapped saturated phase and a
+critical incommensurate gapless phase. The external electric field modifies the
+phase boundaries but does not lead to any new phases. Both external magnetic
+fields and electric fields can be used to tune between the phases. We also show
+that the transverse magnetic field induces a vector chiral order in the
+N\'{e}el phase (even in the absence of an electric field) which can be
+interpreted as an electric polarization in a direction parallel to the AF
+order.",1801.10509v1
+2018-02-20,Controlling magnetism in 2D CrI3 by electrostatic doping,"The atomic thickness of two-dimensional (2D) materials provides a unique
+opportunity to control material properties and engineer new functionalities by
+electrostatic doping. Electrostatic doping has been demonstrated to tune the
+electrical and optical properties of 2D materials in a wide range, as well as
+to drive the electronic phase transitions. The recent discovery of atomically
+thin magnetic insulators has opened up the prospect of electrical control of
+magnetism and new devices with unprecedented performance. Here we demonstrate
+control of the magnetic properties of monolayer and bilayer CrI3 by
+electrostatic doping using a dual-gate field-effect device structure. In
+monolayer CrI3, doping significantly modifies the saturation magnetization,
+coercive force and Curie temperature, showing strengthened (weakened) magnetic
+order with hole (electron) doping. Remarkably, in bilayer CrI3 doping
+drastically changes the interlayer magnetic order, causing a transition from an
+antiferromagnetic ground state in the pristine form to a ferromagnetic ground
+state above a critical electron density. The result reveals a strongly
+doping-dependent interlayer exchange coupling, which enables robust switching
+of magnetization in bilayer CrI3 by small gate voltages.",1802.07355v1
+2018-11-29,Magnetic field effect on the chiral magnetism of noncentrosymmetric UPtGe: experiment and theory,"The effect of differently oriented magnetic field on chiral incommensurate
+helimagnet UPtGe is studied both experimentally and theoretically. The
+magnetization measurements up to the field above the saturation have revealed
+an isotropic magnetic response below 20 T and a remarkable nonmonotonic
+anisotropy in high fields. Moreover, the two principally different phase
+transitions from the noncollinear incommensurate to the field-induced
+ferromagnetic state have been observed. These properties are successfully
+explained by density-functional theory calculations taking into account the
+noncollinearity of the magnetic structures, arbitrary directed magnetic field,
+and relativistic effects. We also estimate the strength of different competing
+magnetic interactions and discuss possible scenarios of the field-induced phase
+transformations.",1811.11952v1
+2019-02-20,Interplay of magnetization dynamics with microwave waveguide at cryogenic temperatures,"In this work, magnetization dynamics is studied at low temperatures in a
+hybrid system that consists of thin epitaxial magnetic film coupled with
+superconducting planar microwave waveguide. The resonance spectrum was observed
+in a wide magnetic field range, including low fields below the saturation
+magnetization and both polarities. Analysis of the spectrum via a developed
+fitting routine allowed to derive all magnetic parameters of the film at
+cryogenic temperatures, to detect waveguide-induced uniaxial magnetic
+anisotropies of the first and the second order, and to uncover a minor
+misalignment of magnetic field. A substantial influence of the superconducting
+critical state on resonance spectrum is observed and discussed.",1902.07566v2
+2019-09-16,Flare Activity and Magnetic Feature Analysis of the Flare Stars,"We analyze the light curve of 1740 flare stars to study the relationship
+between the magnetic feature characteristics and the identified flare activity.
+Coverage and stability of magnetic features are inspired by rotational
+modulation of light curve variations and flare activity of stars are obtained
+using our automated flare detection algorithm. The results show that (i) Flare
+time occupation ratio (or flare frequency) and total power of flares increase
+by increasing relative magnetic feature coverage and contrast in F-M type stars
+(ii) Magnetic feature stability is highly correlated with the coverage and the
+contrast of the magnetic structures as this is the case for the Sun (iii)
+Stability, coverage and contrast of the magnetic features, time occupation
+ratio and total power of flares increases for G, K and M-type stars by
+decreasing Rossby number due to the excess of produced magnetic field from
+dynamo procedure until reaching to saturation level.",1909.07044v1
+2019-10-03,Magnetization process of the breathing pyrochlore magnet CuInCr$_4$S$_8$ in ultra-high magnetic fields up to 150 T,"The magnetization process of the breathing pyrochlore magnet CuInCr4S8 has
+been investigated in ultra-high magnetic fields up to 150 T. Successive phase
+transitions characterized with a substantially wide 1/2-plateau from 55 T to
+110 T are observed in this system, resembling those reported in chromium spinel
+oxides. In addition to the 1/2-plateau phase, the magnetization is found to
+exhibit two inherent behaviors: a slight change in the slope of the M-H curve
+at ~ 85 T and a shoulder-like shape at ~ 130 T prior to the saturation. Both of
+them are accompanied by a hysteresis, suggesting first-order transitions. The
+theoretical calculation applicable to CuInCr4S8 is also shown, based on the
+microscopic model with the spin-lattice coupling. The calculation fairly well
+reproduces the main features of the experimentally observed magnetization
+process, including a relatively wide cant 2:1:1 phase clearly observed in the
+previous work [Y. Okamoto et al., J. Phys. Soc. Jpn. 87, 034709 (2018)]. The
+robust 1/2-plateau on CuInCr4S8 seems to be originated from the dominant
+antiferromagnetic interactions and the strong spin-lattice coupling.",1910.01315v1
+2020-02-04,Accelerated design of Fe-based soft magnetic materials using machine learning and stochastic optimization,"Machine learning was utilized to efficiently boost the development of soft
+magnetic materials. The design process includes building a database composed of
+published experimental results, applying machine learning methods on the
+database, identifying the trends of magnetic properties in soft magnetic
+materials, and accelerating the design of next-generation soft magnetic
+nanocrystalline materials through the use of numerical optimization. Machine
+learning regression models were trained to predict magnetic saturation ($B_S$),
+coercivity ($H_C$) and magnetostriction ($\lambda$), with a stochastic
+optimization framework being used to further optimize the corresponding
+magnetic properties. To verify the feasibility of the machine learning model,
+several optimized soft magnetic materials -- specified in terms of compositions
+and thermomechanical treatments -- have been predicted and then prepared and
+tested, showing good agreement between predictions and experiments, proving the
+reliability of the designed model. Two rounds of optimization-testing
+iterations were conducted to search for better properties.",2002.05225v2
+2020-09-26,Magnetization Plateau Observed by Ultra-High Field Faraday Rotation in a Kagomé Antiferromagnet Herbertsmithite,"To capture the high-field magnetization process of herbertsmithite
+(ZnCu3(OH)6Cl2), Faraday rotation (FR) measurements were carried out on a
+single crystal in magnetic fields of up to 190 T. The magnetization data
+evaluated from the FR angle exhibited a saturation behavior above 150 T at low
+temperatures, which was attributed to the 1/3 magnetization plateau. The
+overall behavior of the magnetization process was reproduced by theoretical
+models based on the nearest-neighbor Heisenberg model. This suggests that
+herbertsmithite is a proximate kagome antiferromagnet hosting an ideal quantum
+spin liquid in the ground state. A distinguishing feature is the superlinear
+magnetization increase, which is in contrast to the Brillouin function-type
+increase observed by conventional magnetization measurements and indicates a
+reduced contribution from free spins located at the Zn sites to the FR signal.",2009.12476v1
+2021-06-17,Magnetization process and ordering of the $S=1/2$ pyrochlore magnet in a field,"We study the $S=1/2$ pyrochlore Heisenberg antiferromagnet in a magnetic
+field. Using large scale density-matrix renormalization group (DMRG)
+calculations for clusters up to $128$ spins, we find indications for a finite
+triplet gap, causing a threshold field to nonzero magnetization in the
+magnetization curve. We obtain a robust saturation field consistent with a
+magnon crystal, although the corresponding $5/6$ magnetization plateau is very
+slim and possibly unstable. Most remarkably, there is a pronounced and
+apparently robust $\frac 1 2$ magnetization plateau where the groundstate
+breaks (real-space) rotational symmetry, exhibiting oppositely polarised spins
+on alternating kagome and triangular planes. Reminiscent of the kagome ice
+plateau of the pyrochlore Ising magnet known as spin ice, it arises via a much
+more subtle `quantum order by disorder' mechanism.",2106.09722v2
+2022-01-10,Soft Magnetic Properties of Ultra-Strong and Nanocrystalline Pearlitic Wires,"The paper describes the capability of magnetic softening of a coarse grained
+bulk material by a severe deformation technique. Connecting the microstructure
+with magnetic properties, the coercive field decreases dramatically for grains
+smaller than the magnetic exchange length. This makes the investigation of soft
+magnetic properties of severely drawn pearlitic wires very interesting. With
+the help of the starting two phase microstructure, it is possible to
+substantially refine the material, which allows the investigation of magnetic
+properties for nanocrystalline bulk material. Compared to the coarse grained
+initial, pearlitic state, the coercivities of the highly deformed wires
+decrease while the saturation magnetization values increase, even beyond the
+value expectable from the individual constituents. The lowest coercivity in the
+drawn state is found to be 520 A m for a wire of 24 um thickness and an
+annealing treatment has a further positive effect on it. The decreasing
+coercivity is discussed in the framework of two opposing models: grain
+refinement on the one hand and dissolution of cementite on the other hand.
+Auxiliary measurements give a clear indication for the latter model, delivering
+a sufficient description of the observed evolution of magnetic properties.",2201.03302v1
+2022-01-18,In-situ alignment of anisotropic hard magnets of 3D printed magnets,"Within this work, we demonstrate in-situ easy-axis alignment of
+single-crystal magnetic particles inside a polymer matrix using fused filament
+fabrication. Two different magnetic materials are investigated: (i) Strontium
+hexaferrite inside a PA6 matrix, fill grade: 49 vol% and (ii) Samarium iron
+nitride inside a PA12 matrix, fill grade: 44 vol%. In the presence of the
+external alignment field, the strontium hexaferrite particles inside the PA6
+matrix can be well aligned with a ratio of remanent magnetization to saturation
+magnetization of 0.7. No significant alignment for samarium iron nitride could
+be achieved. The results show the feasibility to fabricate magnets with
+arbitrary and locally defined easy axis using fused filament fabrication since
+the permanent magnets used for the alignment (or alternatively an
+electromagnet) can be mounted on a rotatable platform.",2201.07111v1
+2022-02-02,Defect Controlled Ferromagnetic Ordering in Au Implanted TiSe$_2$ Nanocrystals,"Layered transition metal dichalcogenides (TMDs) are attracting increasing
+attention because they exhibit unconventional magnetic properties due to
+crystal imperfections in their usually non-magnetic 2D structure. This work
+aims to investigate the magnetic response of self-engineered Se deficient
+TiSe$_2$ thin films, synthesized using chemical vapour deposition. We
+demonstrate tunability of the ferromagnetic order with the introduction of Au
+atoms using low energy Au ion implantation, which works as a controlling knob
+to vary the stoichiometry of Se in TiSe$_{2-x}$. The corresponding isothermal
+field-magnetization curves fit well with a modified Brillouin J function with J
+value of 1.5 for Ti$^{3+}$, and 4 for Au$^{3+}$, accounting for the
+diamagnetism that arises from Au implantation. We propose a qualitative model
+for the experimentally observed magnetization as a function of ion fluence,
+corroborated with high-resolution transmission electron microscopy. Depending
+on the Au nanoparticle size in the implanted samples, magnetization saturates
+faster at a much lower applied magnetic field than the pristine sample. Our
+findings hold potential to expand the range of 2D ferromagnetic materials for
+spintronics and magnetic sensing applications.",2202.01152v1
+2023-04-28,Magnetic phase diagram in three-dimensional triangular-lattice antiferromagnet Sr$_3$CoTa$_2$O$_9$ with small easy-axis anisotropy,"We report the results of low-temperature magnetization and specific heat
+measurements of Sr$_3$CoTa$_2$O$_9$ powder, in which Co$^{2+}$ ions with
+effective spin-1/2 form a uniform triangular lattice in the $ab$ plane. It was
+found that Sr$_3$CoTa$_2$O$_9$ undergoes successive antiferromagnetic
+transitions at $T_{\rm N1}\,{=}\,0.97~{\rm K}$ and $T_{\rm N2}\,{=}\,0.79~{\rm
+K}$ at zero magnetic field. As the magnetic field increases, both $T_{\rm N1}$
+and $T_{\rm N2}$ decrease monotonically. The obtained magnetic field vs
+temperature phase diagram together with a sharp magnetization anomaly at a
+saturation field of ${\mu_0}H_{\rm s}\,{=}\,2.3~{\rm T}$ indicates that
+Sr$_3$CoTa$_2$O$_9$ is described as a spin-1/2 three-dimensional
+triangular-lattice antiferromagnet with a weak easy-axis anisotropy. We discuss
+the characteristics of the magnetic phase diagram, which approximates the phase
+diagram for the magnetic field perpendicular to the $c$ axis.",2304.14693v1
+2023-12-27,Global gyrokinetic simulation of magnetic island induced ion temperature gradient turbulence in toroidal plasma,"The characteristics of ion temperature gradient (ITG) turbulence in the
+presence of a magnetic island are numerically investigated using a gyrokinetic
+model. We observe that in the absence of the usual ITG drive gradient, a
+solitary magnetic island alone can drive ITG instability. The magnetic island
+not only drives high-n modes of ITG instability but also induces low-n modes of
+vortex flow. Moreover, as the magnetic island width increases, the width of the
+vortex flow also increases. This implies that wider islands may more easily
+induce vortex flows. The study further indicates that the saturated amplitude
+and transport level of MI-induced ITG turbulence vary with different magnetic
+island widths. In general, larger magnetic islands enhance both particle and
+heat transport. When the magnetic island is of the order of 21 times the ion
+gyroradius (21\{rho}_i), the turbulence-driven transport level can reach the
+same level in cases where ITG is driven by pressure gradients.",2312.16514v1
+2024-02-22,Barium hexaferrite-based nanocomposites as Random Magnets for microwave absorption H,"The present work reports experimental evidence of random magnetic behavior
+observed in modified barium hexagonal ferrites. A significant transition in the
+magnetic properties of this system is observed when divalent cations (Ni2+,
+Cu2+, Mn2+) are introduced in the structure and give rise to a magnetic
+nanocomposite. Such introduction takes place in a random manner throughout each
+sample and creates the conditions for such materials to behave as random
+magnets. We verify the occurrence of such behavior in our samples by fitting
+the magnetization in approaching saturation to the corresponding theoretical
+model. We therefore analyze the microwave absorption capacities of random
+magnets in the GHz range and predict large and broad absorption signals under
+certain conditions. The findings presented here postulate, for the first time,
+ceramic materials as promising random magnets and underline their potential as
+microwave absorbers, in good agreement with recent theoretical models.",2402.14324v1
+2024-02-24,A simple model of globally magnetized accretion discs,"We present an analytic, quasi-local dynamo model for accretion discs threaded
+by net, vertical magnetic flux. In a simple slab geometry and ignoring
+stochastic mean-field dynamo effects, we calculate the large-scale field
+resulting from the balance between kinematic field amplification and turbulent
+resistive diffusion. The ability of the disc to accumulate magnetic flux is
+sensitive to a single parameter dependent on the ratio of the vertical
+resistive diffusion time to the Alfv\'en crossing time, and we show how the
+saturation levels of magnetorotational and other instabilities can govern disc
+structure and evolution. Under wide-ranging conditions, inflow is governed by
+large-scale magnetic stresses rather than internal viscous stress. We present
+models of such ""magnetically boosted"" discs and show that they lack a radiation
+pressure-dominated zone. Our model can account for ""magnetically elevated""
+discs as well as instances of midplane outflow and field reversals with height
+that have been seen in some global simulations. Using the time-dependent
+features of our model, we find that the incorporation of dynamo effects into
+disc structure can lead to steady or episodic ""magnetically arrested discs""
+(MADs) that maximize the concentration of magnetic flux in their central
+regions.",2402.15657v1
+2003-03-02,"Hyperdiffusion in non-linear, large and small-scale turbulent dynamos","The generation of large-scale magnetic fields is generically accompanied by
+the more rapid growth of small-scale fields. The growing Lorentz force due to
+these fields back reacts on the turbulence to saturate the mean-field and
+small-scale dynamos. For the mean-field dynamo, in a quasi-linear treatment of
+this saturation, it is generally thought that, while the alpha-effect gets
+renormalised and suppressed by non-linear effects, the turbulent diffusion is
+left unchanged. We show here that this is not true and the effect of the
+Lorentz forces, is also to generate additional non-linear hyperdiffusion of the
+mean field. A combination of such non-linear hyperdiffusion with diffusion at
+small scales, also arises in a similar treatment of small-scale dynamos, and is
+crucial to understand its saturation.",0303015v2
+2003-02-13,Anisotropic Caging of Interstitial Vortices in Superconductors with a Square Array of Rectangular Antidots,"We investigate anisotropy in the vortex pinning in thin superconducting films
+with a square array of rectangular submicron holes (""antidots""). The size of
+the antidots is chosen in such a way that it corresponds to a saturation number
+n_s=1, i.e. each antidot can trap at most one flux quantum. Therefore,
+interstitial vortices, appearing when the magnetic field exceeds the first
+matching field, are ""caged"" at the interstitial positions by the repulsion from
+the saturated antidots. We observe an overall higher critical current Ic(H)
+when it is measured parallel to the long side of the antidots than the Ic(H)
+along the short side of the antidots. Although the pinning force, exerted by
+the empty antidot on the vortex, turns out to be isotropic, our I_c(H) data
+indicate that the caging force, experienced by the interstitial vortices and
+provided by the array of saturated antidots, is strongly anisotropic.",0302252v1
+2003-12-01,Non-saturating magnetoresistance in heavily disordered semiconductors,"The resistance of a homogeneous semiconductor increases quadratically with
+magnetic field at low fields and, except in very special cases, saturates at
+fields much larger than the inverse of the carrier mobility, a number typically
+of order 1 Tesla. Here, we argue that a macroscopically disordered and strongly
+inhomogeneous semiconductor will instead show a non-saturating
+magnetoresistance, with typically a quasi-linear behaviour up to very large
+fields, and possibly also extending down to very low fields, depending on the
+degree of inhomogeneity. We offer this as a possible explanation of the
+observed anomalously large magnetoresistance in doped silver chalcogenides.
+Furthermore, our model of an inhomogeneous semiconductor can be developed into
+magnetoresistive devices that possess a large, controllable, linear response.",0312020v1
+2004-04-08,Finite low-temperature entropy of some strongly frustrated quantum spin lattices in the vicinity of the saturation field,"For a class of highly frustrated antiferromagnetic quantum spin lattices the
+ground state exhibits a huge degeneracy in high magnetic fields due to the
+existence of localized magnon states. For some of these spin lattices (in
+particular, the 1D dimer-plaquette, sawtooth and kagom\'{e}-like chains as well
+as the 2D kagom\'{e} lattice) we calculate rigorously the ground-state entropy
+at the saturation field. We find that the ground-state entropy per site remains
+finite at saturation. This residual ground-state entropy produces a maximum in
+the field dependence of the isothermal entropy at low temperatures. By
+numerical calculation of the field dependence of the low-temperature entropy
+for the sawtooth chain we find that the enhancement of isothermal entropy is
+robust against small deviations in exchange constants. Moreover, the effect is
+most pronounced in the extreme quantum case of spin 1/2.",0404204v1
+2005-09-12,Two component butterfly hysteresis in Ru1222 ruthenocuprate,"We report detailed studies of the ac susceptibility butterfly hysteresis on
+the Ru1222 ruthenocuprate compounds. Two separate contributions to these
+hysteresis have been identified and studied. One contribution is
+ferromagnetic-like and is characterized by the coercive field maximum. Another
+contribution, represented by the so called inverted maximum, is related to the
+unusual inverted loops, unique feature of Ru1222 butterfly hysteresis. The
+different nature of the two identified magnetic contributions is proved by the
+different temperature dependences involved. By lowering the temperature the
+inverted peak gradually disappears while the coercive field slowly raises. If
+the maximum dc field for the hysteresis is increased, the size of the inverted
+part of the butterfly hysteresis monotonously grows while the position of the
+peak saturates. In reaching saturation exponential field dependence has been
+demonstrated to take place. At T = 78 K the saturation field is 42 Oe.",0509295v1
+2006-09-15,Surfactant effects in monodisperse magnetite nanoparticles of controlled size,"Monodisperse magnetite Fe3O4 nanoparticles of controlled size within 6 and 20
+nm in diameter were synthesized by thermal decomposition of an iron organic
+precursor in an organic medium. Particles were coated with oleic acid. For all
+samples studied, saturation magnetization Ms reaches the expected value for
+bulk magnetite, in contrast to results in small particle systems for which Ms
+is usually much smaller due to surface spin disorder. The coercive field for
+the 6 nm particles is also similar to that of bulk magnetite. Both results
+suggest that the oleic acid molecules covalently bonded to the nanoparticle
+surface yield a strong reduction in the surface spin disorder. However,
+although the saturated state may be similar, the approach to saturation is
+different and, in particular, the high-field differential susceptibility is one
+order of magnitude larger than in bulk materials. The relevance of these
+results in biomedical applications is discussed.",0609384v1
+2005-02-24,BPS saturation of the N=4 monopole by infinite composite-operator renormalization,"Quantum corrections to the magnetic central charge of the monopole in N=4
+supersymmetric Yang-Mills theory are free from the anomalous contributions that
+were crucial for BPS saturation of the two-dimensional supersymmetric kink and
+the N=2 monopole. However these quantum corrections are nontrivial and they
+require infinite renormalization of the supersymmetry current, central charges,
+and energy-momentum tensor, in contrast to N=2 and even though the N=4 theory
+is finite. Their composite-operator renormalization leads to counterterms which
+form a multiplet of improvement terms. Using on-shell renormalization
+conditions the quantum corrections to the mass and the central charge then
+vanish both, thus verifying quantum BPS saturation.",0502221v3
+2007-01-30,Saturable discrete vector solitons in one-dimensional photonic lattices,"Localized vectorial modes, with equal frequencies and mutually orthogonal
+polarizations, are investigated both analytically and experimentally in a
+one-dimensional photonic lattice with saturable nonlinearity. It is shown that
+these modes may span over many lattice elements and that energy transfer among
+the two components is both phase and intensity dependent. The transverse
+electrically polarized mode exhibits a single-hump structure and spreads in
+cascades in saturation, while the transverse magnetically polarized mode
+exhibits splitting into a two-hump structure. Experimentally such discrete
+vector solitons are observed in lithium niobate lattices for both coherent and
+mutually incoherent excitations.",0701060v1
+2006-03-24,Rigorous approach to the nonlinear saturation of the tearing mode in cylindrical and slab geometry,"The saturation of the tearing mode instability is described within the
+standard framework of reduced magnetohydrodynamics (RMHD) in the case of an
+$r$-dependent or of a uniform resistivity profile. Using the technique of
+matched asymptotic expansions, where the perturbation parameter is the island
+width $w$, the problem can be solved in two ways: with the so-called flux
+coordinate method, which is based on the fact that the current profile is a
+flux function, and with a new perturbative method that does not use this
+property. The latter is applicable to more general situations where an external
+forcing or a sheared velocity profile are involved. The calculation provides a
+new relationship between the saturated island width and the $\Delta '$
+stability parameter that involves a $\ln{w/w_{0}}$ term, where $w_{0}$ is a
+nonlinear scaling length that was missing in previous work. It also yields the
+modification of the equilibrium magnetic flux function.",0603204v1
+2007-09-07,Flux saturation number of superconducting rings,"The distributions of electrical current and magnetic field in a thin-film
+superconductor ring is calculated by solving the London equation. The maximum
+amount of flux trapped by the hole, the fluxoid saturation number, is obtained
+by limiting the current density by the depairing current. The results are
+compare it with similar results derived for the bulk case of a long hollow
+cylinder [Nordborg & Vinokur, Phys. Rev. B 62, 12408 (2000)]. In the limit of
+small holes our result reduces to the Pearl solution for an isolated vortex in
+a thin film. For large hole radius, the ratio between saturation numbers in
+bulk and film superconductors is proportional to the square root of the hole
+size.",0709.1086v3
+2010-07-27,Vertical Structure and Turbulent Saturation Level in Fully Radiative Protoplanetary Disc Models,"We investigate a massive ($\varSigma \sim 10000 g cm^{-2}$ at 1 AU)
+protoplanetary disc model by means of 3D radiation magnetohydrodynamics
+simulations. The vertical structure of the disc is determined self-consistently
+by a balance between turbulent heating caused by the MRI and radiative cooling.
+Concerning the vertical structure, two different regions can be distinguished:
+A gas-pressure dominated, optically thick midplane region where most of the
+dissipation takes place, and a magnetically dominated, optically thin corona
+which is dominated by strong shocks. At the location of the photosphere, the
+turbulence is supersonic ($M \sim 2$), which is consistent with previous
+results obtained from the fitting of spectra of YSOs. It is known that the
+turbulent saturation level in simulations of MRI-induced turbulence does depend
+on numerical factors such as the numerical resolution and the box size.
+However, by performing a suite of runs at different resolutions (using up to
+64x128x512 grid cells) and with varying box sizes (with up to 16 pressure
+scaleheights in the vertical direction), we find that both the saturation
+levels and the heating rates show a clear trend to converge once a sufficient
+resolution in the vertical direction has been achieved.",1007.4747v1
+2010-08-25,Alleviating alpha quenching by solar wind and meridional flow,"We study the ability of magnetic helicity expulsion to alleviate catastrophic
+$\alpha$-quenching in mean field dynamos in two--dimensional spherical wedge
+domains. Motivated by the physical state of the outer regions of the Sun, we
+consider $\alpha^2\Omega$ mean field models with a dynamical $\alpha$
+quenching. We include two mechanisms which have the potential to facilitate
+helicity expulsion, namely advection by a mean flow (""solar wind"") and
+meridional circulation. We find that a wind alone can prevent catastrophic
+quenching, with the field saturating at finite amplitude. In certain parameter
+ranges, the presence of a large-scale meridional circulation can reinforce this
+alleviation. However, the saturated field strengths are typically below the
+equipartition field strength. We discuss possible mechanisms that might
+increase the saturated field.",1008.4226v2
+2011-02-22,The effect of magnetic activity saturation in chromospheric flux-flux relationships,"We present a homogeneous study of chromospheric and coronal flux-flux
+relationships using a sample of 298 late-type dwarf active stars with spectral
+types F to M. The chromospheric lines were observed simultaneously in each star
+to avoid spread due to long term variability. Unlike other works, we subtract
+the basal chromospheric contribution in all the spectral lines studied. For the
+first time, we quantify the departure of dMe stars from the general relations.
+We show that dK and dKe stars also deviate from the general trend. Studying the
+flux-colour diagrams we demonstrate that the stars deviating from the general
+relations are those with saturated X-ray emission and that those stars also
+present saturation in the H$\alpha$ line. Using several age spectral
+indicators, we show that they are younger stars than those following the
+general relationships. The non-universality of flux-flux relationships found in
+this work should be taken into account when converting between fluxes in
+different chromospheric activity indicators.",1102.4506v1
+2012-10-19,Non-Dissipative Saturation of the Magnetorotational Instability in Thin Disks,"A new non-dissipative mechanism is proposed for the saturation of the
+axisymmetric magnetorotational (MRI) instability in thin Keplerian disks that
+are subject to an axial magnetic field. That mechanism relies on the energy
+transfer from the MRI to stable magnetosonic (MS) waves. Such mode interaction
+is enabled due to the vertical stratification of the disk that results in the
+discretization of its MRI spectrum, as well as by applying the appropriate
+boundary conditions. A second order Duffing-like amplitude equation for the
+initially unstable MRI modes is derived. The solutions of that equation exhibit
+bursty nonlinear oscillations with a constant amplitude that signifies the
+saturation level of the MRI. Those results are verified by a direct numerical
+solution of the full nonlinear reduced set of thin disk magnetohydrodynamics
+equations.",1210.5343v1
+2014-07-03,Theoretical aspect of enhancement and saturation in emission from laser produced plasma,"This paper presents a simplified theoretical model for the study of emission
+from laser produced plasma to better understand the processes and the factors
+involved in the onset of saturation in plasma emission as well as in increasing
+emission due to plasma confinement. This model considers that plasma emission
+is directly proportional to the square of plasma density, its volume and the
+fraction of laser pulse absorbed through inverse Bremsstrahlung in the
+pre-formed plasma plume produced by the initial part of the laser. This shows
+that plasma density and temperature decide the threshold for saturation in
+emission, which occurs for electron ion collision frequency more than 10E13 Hz,
+beyond which plasma shielding effects become dominant. Any decrease in plasma
+sound (expansion) velocity shows drastic enhancement in emission supporting the
+results obtained by magnetic as well as spatial confinement of laser produced
+plasma. The temporal evolution of plasma emission in the absence and presence
+of plasma confinement along with the effect of laser pulse duration are also
+discussed in the light of this model.",1407.0775v1
+2016-12-05,Numerical simulations of the Princeton magneto-rotational instability experiment with conducting axial boundaries,"We investigate numerically the Princeton magneto-rotational instability (MRI)
+experiment and the effect of conducting axial boundaries or endcaps. MRI is
+identified and found to reach a much higher saturation than for insulating
+endcaps. This is probably due to stronger driving of the base flow by the
+magnetically rather than viscously coupled boundaries. Although the
+computations are necessarily limited to lower Reynolds numbers ($\Re$) than
+their experimental counterparts, it appears that the saturation level becomes
+independent of $\Re$ when $\Re$ is sufficiently large, whereas it has been
+found previously to decrease roughly as $\Re^{-1/4}$ with insulating endcaps.
+The much higher saturation levels will allow for the first positive detection
+of MRI beyond its theoretical and numerical predictions.",1612.01224v1
+2019-06-08,Area Law Saturation of Entropy Bound from Perturbative Unitarity in Renormalizable Theories,"We study the quantum information storage capacity of solitons and baryons in
+renormalizable quantum field theories that do not include gravity. We observe
+that a 't Hooft-Polyakov magnetic monopole saturates the Bekenstein bound on
+information when the theory saturates the bound on perturbative unitarity. In
+this very limit the monopole entropy assumes the form of an area-law,
+strikingly similar to a black hole entropy in gravity. The phenomenon appears
+universal and takes place for other solitons and non-perturbative objects. We
+observe the same behaviour of entropy of a baryon in QCD with large number of
+colors. These observations indicate that the area-law form of the entropy bound
+extends beyond gravity and is deeply rooted in concepts of weak coupling and
+perturbative unitarity. One provoked idea is that confinement in QCD may be
+understood as a prevention mechanism against violation of Bekenstein entropy
+bound by colored states.",1906.03530v1
+2022-07-06,Evidence of decoupling of surface and bulk states in Dirac semimetal $Cd_{3}As_{2}$,"Dirac semimetals have attracted a great deal of current interest due to their
+potential applications in topological quantum computing, low-energy electronic
+applications, and single photon detection in the microwave frequency range.
+Herein are results from analyzing the low magnetic (B) field
+weak-antilocalization behaviors in a Dirac semimetal $Cd_{3}As_{2}$ thin flake
+device. At high temperatures, the phase coherence length $l_{\phi}$ first
+increases with decreasing temperature (T) and follows a power law dependence of
+$l_{\phi}\propto$ T$^{-0.4}$. Below ~ 3K, $l_{\phi}$ tends to saturate to a
+value of ~ 180 nm. Another fitting parameter $\alpha$, which is associated with
+independence transport channels, displays a logarithmic temperature dependence
+for T > 3K, but also tends to saturate below ~ 3K. The saturation value, ~
+1.45, is very close to 1.5, indicating three independent electron transport
+channels, which we interpret as due to decoupling of both the top and bottom
+surfaces as well as the bulk. This result, to our knowledge, provides first
+evidence that the surfaces and bulk states can become decoupled in electronic
+transport in Dirac semimetal $Cd_{3}As_{2}$.",2207.02461v1
+2023-06-26,A Way of Determination of Axion Mass with Quantum Hall Effect,"Axion dark matter is converted to electromagnetic radiations in the presence
+of strong magnetic field. The radiations possibly give rise to non trivial
+phenomena in condensed matter physics. Especially, we discuss that saturation
+of plateau-plateau transition width observed at low temperature in integer
+quantum Hall effect is caused by the axion. The radiations from axions are
+inevitably present in the experiment. Although the radiations generated by
+axion is extremely weak, Hall conductivity jumps up to next plateau even if
+only a single electron occupies an extended state; a localized electron is
+transited to the extended state by absorbing the radiation. According to our
+analysis, previous experiment\cite{sat6} of the saturation in detail suggests
+that the axion mass is in the range $10^{-5}\mbox{eV}\sim 10^{-6}$eV. We
+propose a way of the determination of the axion mass by imposing microwaves on
+Hall bar and also a way of the confirmation that the axion really causes the
+saturation of the width.",2306.14475v3
+1997-07-25,Can the turbulent galactic dynamo generate large-scale magnetic fields?,"Large-scale magnetic fields in galaxies are thought to be generated by a
+turbulent dynamo. However the same turbulence also leads to a small-scale
+dynamo which generates magnetic noise at a more rapid rate. The efficiency of
+the large-scale dynamo depends on how this noise saturates. We examine this
+issue taking into account ambipolar drift, which obtains in a galaxy with
+significant neutral gas. We argue that, (1) the small-scale dynamo generated
+field does not fill the volume, but is concentrated into intermittent rope like
+structures. The flux ropes are curved on the turbulent eddy scales. Their
+thickness is set by the diffusive scale determined by the effective ambipolar
+diffusion; (2) For a largely neutral galactic gas, the small-scale dynamo
+saturates, due to inefficient random stretching, when the peak field in a flux
+rope has grown to a few times the equipartition value; (3) The average energy
+density in the saturated small-scale field is sub equipartition, since it does
+not fill the volume; (4) Such fields neither drain significant energy from the
+turbulence nor convert eddy motion of the turbulence on the outer scale into
+wavelike motion. The diffusive effects needed for the large-scale dynamo
+operation are then preserved until the large-scale field itself grows to near
+equipartition levels.",9707280v1
+2003-02-12,Dephasing of Electrons in Mesoscopic Metal Wires,"We have extracted the phase coherence time $\tau_{\phi}$ of electronic
+quasiparticles from the low field magnetoresistance of weakly disordered wires
+made of silver, copper and gold. In samples fabricated using our purest silver
+and gold sources, $\tau_{\phi}$ increases as $T^{-2/3}$ when the temperature
+$T$ is reduced, as predicted by the theory of electron-electron interactions in
+diffusive wires. In contrast, samples made of a silver source material of
+lesser purity or of copper exhibit an apparent saturation of $\tau_{\phi}$
+starting between 0.1 and 1 K down to our base temperature of 40 mK. By
+implanting manganese impurities in silver wires, we show that even a minute
+concentration of magnetic impurities having a small Kondo temperature can lead
+to a quasi saturation of $\tau_{\phi}$ over a broad temperature range, while
+the resistance increase expected from the Kondo effect remains hidden by a
+large background. We also measured the conductance of Aharonov-Bohm rings
+fabricated using a very pure copper source and found that the amplitude of the
+$h/e$ conductance oscillations increases strongly with magnetic field. This set
+of experiments suggests that the frequently observed ``saturation'' of
+$\tau_{\phi}$ in weakly disordered metallic thin films can be attributed to
+spin-flip scattering from extremely dilute magnetic impurities, at a level
+undetectable by other means.",0302235v2
+2005-06-14,High field properties of geometrically frustrated magnets,"Above the saturation field, geometrically frustrated quantum antiferromagnets
+have dispersionless low-energy branches of excitations corresponding to
+localized spin-flip modes. Transition into a partially magnetized state occurs
+via condensation of an infinite number of degrees of freedom. The ground state
+below the phase transition is a magnon crystal, which breaks only translational
+symmetry and preserves spin-rotations about the field direction. We give a
+detailed review of recent works on physics of such phase transitions and
+present further theoretical developments. Specifically, the low-energy degrees
+of freedom of a spin-1/2 kagom\'e antiferromagnet are mapped to a hard hexagon
+gas on a triangular lattice. Such a mapping allows to obtain a quantitative
+description of the magnetothermodynamics of a quantum kagom\'e antiferromagnet
+from the exact solution for a hard hexagon gas. In particular, we find the
+exact critical behavior at the transition into a magnon crystal state, the
+universal value of the entropy at the saturation field, and the position of
+peaks in temperature- and field-dependence of the specific heat. Analogous
+mapping is presented for the sawtooth chain, which is mapped onto a model of
+classical hard dimers on a chain. The finite macroscopic entropies of
+geometrically frustrated magnets at the saturation field lead to a large
+magnetocaloric effect.",0506327v2
+2015-08-11,A unified large/small-scale dynamo in helical turbulence,"We use high resolution direct numerical simulations (DNS) to show that
+helical turbulence can generate significant large-scale fields even in the
+presence of strong small-scale dynamo action. During the kinematic stage, the
+unified large/small-scale dynamo grows fields with a shape-invariant
+eigenfunction, with most power peaked at small scales or large $k$, as in
+\citet{SB14}. Nevertheless, the large-scale field can be clearly detected as an
+excess power at small $k$ in the negatively polarized component of the energy
+spectrum for a forcing with positively polarized waves. Its strength $bar{B}$,
+relative to the total rms field $B_{rms}$, decreases with increasing magnetic
+Reynolds number, $R_m$. However, as the Lorentz force becomes important, the
+field generated by the unified dynamo orders itself by saturating on
+successively larger scales. The magnetic integral scale for the positively
+polarized waves, characterizing the small-scale field, increases significantly
+from the kinematic stage to saturation. This implies that the small-scale field
+becomes as coherent as possible for a given forcing scale, which averts the
+$R_m$-dependent quenching of $\bar{B}/B_rms$. These results are obtained for
+$1024^3$ DNS with magnetic Prandtl numbers of $P_m=0.1$ and $10$. For
+$P_m=0.1$, $\bar{B}/B_{rms}$ grows from about $0.04$ to about $0.4$ at
+saturation, aided in the final stages by helicity dissipation. For $P_m=10$,
+$\bar{B}/B_{rms}$ grows from much less than 0.01 to values of the order the
+$0.2$. Our results confirm that there is a unified large/small-scale dynamo in
+helical turbulence.",1508.02706v2
+2016-09-05,Inflows towards active regions and the modulation of the solar cycle: a parameter study,"Aims: We aim to investigate how converging flows towards active regions
+affect the surface transport of magnetic flux, as well as their impact on the
+generation of the Sun's poloidal field. The inflows constitute a potential
+non-linear mechanism for the saturation of the global dynamo and may contribute
+to the modulation of the solar cycle in the Babcock-Leighton framework.
+  Methods: We build a surface flux transport code incorporating a parametrized
+model of the inflows and run simulations spanning several cycles. We carry out
+a parameter study to assess how the strength and extension of the inflows
+affect the build-up of the global dipole field. We also perform simulations
+with different levels of activity to investigate the potential role of the
+inflows in the saturation of the global dynamo.
+  Results: We find that the interaction of neighbouring active regions can lead
+to the occasional formation of single-polarity magnetic flux clumps
+inconsistent with observations. We propose the darkening caused by pores in
+areas of high magnetic field strength as a plausible mechanism preventing this
+flux-clumping. We find that inflows decrease the amplitude of the axial dipole
+moment by a $\sim30\,\%$, relative to a no-inflows scenario. Stronger (weaker)
+inflows lead to larger (smaller) reductions of the axial dipole moment. The
+relative amplitude of the generated axial dipole is about $9\%$ larger after
+very weak cycles than after very strong cycles. This supports the inflows as a
+non-linear mechanism capable of saturating the global dynamo and contributing
+to the modulation of the solar cycle within the Babcock-Leighton framework.",1609.01199v1
+2022-06-30,Experimental Demonstration of a Spin-Wave Lens Designed with Machine Learning,"We present the design and experimental realization of a device that acts like
+a spin-wave lens i.e., it focuses spin waves to a specified location. The
+structure of the lens does not resemble any conventional lens design, it is a
+nonintuitive pattern produced by a machine learning algorithm. As a spin-wave
+design tool, we used our custom micromagnetic solver ""SpinTorch"" that has
+built-in automatic gradient calculation and can perform backpropagation through
+time for spin-wave propagation. The training itself is performed with the
+saturation magnetization of a YIG film as a variable parameter, with the goal
+to guide spin waves to a predefined location. We verified the operation of the
+device in the widely used mumax3 micromagnetic solver, and by experimental
+realization. For the experimental implementation, we developed a technique to
+create effective saturation-magnetization landscapes in YIG by direct
+focused-ion-beam irradiation. This allows us to rapidly transfer the nanoscale
+design patterns to the YIG medium, without patterning the material by etching.
+We measured the effective saturation magnetization corresponding to the FIB
+dose levels in advance and used this mapping to translate the designed
+scatterer to the required dose levels. Our demonstration serves as a proof of
+concept for a workflow that can be used to realize more sophisticated spin-wave
+devices with complex functionality, e.g., spin-wave signal processors, or
+neuromorphic devices.",2207.00055v1
+2023-02-26,How well can VMEC predict the initial saturation of external kink modes in near circular tokamaks and $l=2$ stellarators?,"The equilibrium code, VMEC, is used to study external kinks in low $\beta$
+tokamaks and $l=2$ stellarators. The applicability of the code when modelling
+nonlinear MHD effects is explored in an attempt to understand and predict how
+the initial saturation of the MHD mode depends on the external rotational
+transform. It is shown that helicity preserving, free boundary VMEC
+computations do not converge to a single perturbed solution with increasing
+spectral resolution. Additional constraints are therefore applied to narrow
+down the numerical resolution parameters appropriate for physical scans. The
+dependence of the modelled (4, 1) kink mode on the external rotational
+transform and field periodicity is then studied. While saturated states can be
+identified which decrease in amplitude with increasing external rotational
+transform, bifurcated states are found that contradict this trend. It was
+therefore not possible to use VMEC alone to identify the physical dependency of
+the nonlinear mode amplitude on the magnetic geometry. The accuracy of the VMEC
+solutions is nevertheless demonstrated by showing that the expected toroidal
+mode coupling is captured in the magnetic energy spectrum for stellarator
+cases. Comparing with the initial value code, JOREK, the predicted
+redistribution of poloidal magnetic energy from the vacuum to plasma region in
+VMEC is shown to be physical. This work is a first step towards using VMEC to
+study MHD modes in stellarator geometry.",2302.13291v2
+2023-07-17,Nonlinear mode coupling and energetics of driven magnetized shear-flow turbulence,"To comprehensively understand saturation of two-dimensional ($2$D) magnetized
+Kelvin-Helmholtz-instability-driven turbulence, energy transfer analysis is
+extended from the traditional interaction between scales to include eigenmode
+interactions, by using the nonlinear couplings of linear eigenmodes of the
+ideal instability. While both kinetic and magnetic energies cascade to small
+scales, a significant fraction of turbulent energy deposited by unstable modes
+in the fluctuation spectrum is shown to be re-routed to the conjugate-stable
+modes at the instability scale. They remove energy from the forward cascade at
+its inception. The remaining cascading energy flux is shown to attenuate
+exponentially at a small scale, dictated by the large-scale stable modes.
+Guided by a widely used instability-saturation assumption, a general
+quasilinear model of instability is tested by retaining all nonlinear
+interactions except those that couple to the large-scale stable modes. These
+complex interactions are analytically removed from the magnetohydrodynamic
+equations using a novel technique. Observations are: an explosive large-scale
+vortex separation instead of the well-known merger of $2$D, a dramatic
+enhancement in turbulence level and spectral energy fluxes, and a reduced
+small-scale dissipation length-scale. These show critical role of the stable
+modes in instability saturation. Possible reduced-order turbulence models are
+proposed for fusion and astrophysical plasmas, based on eigenmode-expanded
+energy transfer analyses.",2307.08895v1
+2000-12-01,Two-dimensional disk dynamos with vertical outflows into a halo,"We study the effects of vertical outflows on mean-field dynamos in disks.
+These outflows could be due to thermal winds or magnetic buoyancy. We analyse
+numerical solutions of the nonlinear mean-field dynamo equations using a
+two-dimensional finite-difference model. Contrary to expectations, a modest
+vertical velocity can enhance dynamo action. This can lead to super-exponential
+growth of the magnetic field and to higher magnetic energies at saturation in
+the nonlinear regime.",0012013v1
+2001-05-21,A Solvable Model for Nonlinear Mean Field Dynamo,"We formulate a solvable model that describes generation and saturation of
+mean magnetic field in a dynamo with kinetic helicity, in the limit of large
+magnetic Prandtl number. This model is based on the assumption that the
+stochastic part of the velocity field is Gaussian and white in time (the
+Kazantsev-Kraichnan ensemble), while the regular part describing the back
+reaction of the magnetic field is chosen from balancing the viscous and Lorentz
+stresses in the MHD Navier-Stokes equation. The model provides an analytical
+explanation for previously obtained numerical results.",0105354v1
+2002-07-25,A Taylor-Couette Dynamo,"Recent experiments have shown that it is possible to study a fundamental
+astrophysical process such as dynamo action in controlled laboratory conditions
+using simple MHD flows. In this paper we explore the possibility that
+Taylor-Couette flow, already proposed as a model of the magneto-rotational
+instability of accretion discs, can sustain generation of magnetic field.
+Firstly, by solving the kinematic dynamo problem, we identify the region of
+parameter space where the magnetic field's growth rate is higher. Secondly, by
+solving simultaneously the coupled nonlinear equations which govern velocity
+field and magnetic field, we find a self-consistent nonlinearly saturated
+dynamo.",0207566v1
+1998-09-09,Magnetization plateau and quantum phase transition of the S=1/2 trimerized XXZ spin chain,"We study the plateau of the magnetization curve at $M = M_{\rm s}/3$ ($M_{\rm
+s}$ is the saturation magnetization) of the $S=1/2$ trimerized $XXZ$ spin
+chain. By examining the level crossing of low-lying excitations obtained from
+the numerical diagonalization, we precisely determine the phase boundary
+between the plateau state and the no-plateau state on the $\Delta-t$ plane,
+where $\Delta$ denotes the $XXZ$ anisotropy and $t$ the magnitude of the
+trimerization. This quantum phase transition is of the
+Berezinskii-Kosterlitz-Thouless type.",9809138v1
+1998-09-22,Magnetization plateau in the spin ladder with the four-spin exchange,"The magnetization process of the $S$=1/2 antiferromagnetic spin ladder with
+the four-spin cyclic exchange interaction at T=0 is studied by the exact
+diagonalization of finite clusters and size scaling analyses. It is found that
+a magnetization plateau appears at half the saturation value if the ratio of
+the four- and two-spin exchange coupling constants $J_4$ is larger than the
+critical value $J_{4c}=0.05\pm$0.04. The phase transition with respect to $J_4$
+at $J_{4c}$ is revealed to be the Kosterlitz-Thouless-type.",9809291v1
+1999-04-05,Spin Degree of Freedom in a Two-Dimensional Electron Liquid,"We have investigated correlation between spin polarization and
+magnetotransport in a high mobility silicon inversion layer which shows the
+metal-insulator transition. Increase in the resistivity in a parallel magnetic
+field reaches saturation at the critical field for the full polarization
+evaluated from an analysis of low-field Shubnikov-de Haas oscillations. By
+rotating the sample at various total strength of the magnetic field, we found
+that the normal component of the magnetic field at minima in the diagonal
+resistivity increases linearly with the concentration of ``spin-up'' electrons.",9904058v1
+2000-08-30,Hall Coefficient of a Dilute 2D Electron System in Parallel Magnetic Field,"Measurements in magnetic fields applied at a small angle with respect to the
+2D plane of the electrons of a low-density silicon MOSFET indicate that the
+Hall coefficient is independent of parallel field from H=0 to $H>H_{sat}$, the
+field above which the longitudinal resistance saturates and the electrons have
+reached full spin-polarization. This implies that the mobilities of the spin-up
+and spin-down electrons remain comparable at all magnetic fields, and suggests
+there is strong mixing of spin-up and spin-down electron states.",0008456v1
+2000-11-02,Magnetization Plateau of an S=1 Frustrated Spin Ladder,"We study the magnetization plateau at 1/4 of the saturation magnetization of
+the S=1 antiferromagnetic spin ladder both analytically and numerically, with
+the aim of explaining recent experimental results on BIP-TENO by Goto et al. We
+propose two mechanisms for the plateau formation and clarify the plateau phase
+diagram on the plane of the coupling constants between spins.",0011034v1
+2001-07-30,Field induced transitions in a kagome antiferromagnet,"The thermal order by disorder effect in magnetic field is studied for a
+classical Heisenberg antiferromagnet on the kagome lattice. Using analytical
+arguments we predict a unique H-T phase diagram for this strongly frustrated
+magnet: states with a coplanar and a uniaxial triatic order parameters
+respectively at low and high magnetic fields and an incompressible collinear
+spin-liquid state at a one-third of the saturation field. We also present the
+Monte Carlo data which confirm existence of these phases.",0107608v3
+2001-09-03,Mechanisms for Non-Trivial Magnetization Plateaux of an S=1 Frustrated Spin Ladder,"We investigate the non-trivial magnetization plateau at 1/4 of the saturation
+magnetization of S=1 spin ladder, especially with reference to recent
+experimental results on a new organic tetraradical
+3,3',5,5'-tetrakis(N-tert-butylaminoxyl)biphenyl, abbreviated as BIP-TENO. We
+propose three mechanisms for the formation of the plateau; the Neel mechanism,
+the dimer mechanism and the spin-Peierls mechanism. We also discuss the effect
+of four-spin exchange interactions.",0109035v1
+2002-10-13,Enhanced magnetocaloric effect in frustrated magnets,"The magnetothermodynamics of strongly frustrated classical Heisenberg
+antiferromagnets on kagome, garnet, and pyrochlore lattices is examined. The
+field induced adiabatic temperature change (dT/dH)_S is significantly larger
+for such systems compared to ordinary non-frustrated magnets and also exceeds
+the cooling rate of an ideal paramagnet in a wide range of fields. An
+enhancement of the magnetocaloric effect is related to presence of a
+macroscopic number of soft modes in frustrated magnets below the saturation
+field. Theoretical predictions are confirmed with extensive Monte Carlo
+simulations.",0210288v1
+2003-10-06,"Ferromagnetism in (In,Mn)As alloy thin films grown by metalorganic vapor phase epitaxy","Ferromagnetic properties of In1-xMnxAs thin films were investigated. Room
+temperature ferromagnetic order was observed in nominally single-phase films
+with x = 0.01-0.10. Magnetization measurements indicated that these In1-xMnxAs
+samples had a Curie temperature of 333 K. The Curie temperature was independent
+of Mn concentration. The temperature dependent magnetization along with the
+magnitude of the saturation magnetization and microstructural data indicate
+that the source of the high-temperature ferromagnetism in single-phase films is
+not attributable to MnAs nanoprecipitates. The high transition temperature is
+attributed to the presence of near neighbor Mn pairs.",0310104v1
+2005-09-15,Reduction of the ordered magnetic moment in YMnO3 with hydrostatic pressure,"YMnO3 exhibits a ferroelectric transition at high temperature (~ 900 K) and
+magnetic ordering at T_N ~ 70 K where the dielectric constant shows an anomaly
+indicative of the magneto-dielectric effect. Here we report powder neutron
+diffraction experiments in this compound that show that the magnetic moment at
+saturation is reduced by application of hydrostatic pressure. Our results yield
+further insight about the nature of the spin-lattice interaction in ferroic
+materials.",0509413v1
+2005-10-21,Structural distortions of frustrated quantum spin lattices in high magnetic fields,"We study the stability of some strongly frustrated antiferromagnetic spin
+lattices in high magnetic fields against lattice distortions. In particular, we
+consider a spin-s anisotropic Heisenberg antiferromagnet on the
+square-kagom\'{e} and kagom\'{e} lattices. The independent localized magnons
+embedded in a ferromagnetic environment, which are the ground state at the
+saturation field, imply lattice instabilities for appropriate lattice
+distortions fitting to the structure of the localized magnons. We discuss in
+detail the scenario of this spin-Peierls instability in high magnetic fields
+which essentially depends on the values of the exchange interaction anisotropy
+\Delta and spin s.",0510582v1
+2006-03-24,Magnetic resonance in a pyrochlore antiferromagnet Gd2Ti2O7,"Electron spin resonance study of frustrated pyrochlore Gd2Ti2O7 is performed
+in a wide frequency band for a temperature range 0.4-30 K, which covers
+paramagnetic and magnetically ordered phases. The paramagnetic resonance
+reveals the spectroscopic g-factor about 2.0 and a temperature dependent
+linewidth. In ordered phases magnetic resonance spectra are distinctive for a
+nonplanar cubic (or tetrahedral) antiferromagnet with an isotropic
+susceptibility. In the high-field saturated phase, weakly-dispersive soft modes
+are observed and their field evolution is traced.",0603653v1
+2006-05-24,CVD of CrO2 Thin Films: Influence of the Deposition Parameters on their Structural and Magnetic Properties,"This work reports on the synthesis of CrO2 thin films by atmospheric pressure
+CVD using chromium trioxide (CrO3) and oxygen. Highly oriented (100) CrO2 films
+containing highly oriented (0001) Cr2O3 were grown onto Al2O3(0001) substrates.
+Films display a sharp magnetic transition at 375 K and a saturation
+magnetization of 1.92 Bohr magnetons per f.u., close to the bulk value of 2
+Bohr magnetons per f.u. for the CrO2.
+  Keywords: Chromium dioxide (CrO2), Atmospheric pressure CVD, Spintronics.",0605600v1
+2006-07-03,Orbital contribution to the magnetic properties of nanowires: Is the orbital polarization ansatz justified?,"We show that considerable orbital magnetic moments and magneto-crystalline
+anisotropy energies are obtained for a Fe monatomic wire described in a
+tight-binding method with intra-atomic electronic interactions treated in a
+full Hartree Fock (HF) decoupling scheme. Even-though the use of the orbital
+polarization ansatz with simplified Hamiltonians leads to fairly good results
+when the spin magnetization is saturated this is not the case of unsaturated
+systems. We conclude that the full HF scheme is necessary to investigate low
+dimensional systems.",0607047v2
+1998-02-13,Transverse quasilinear relaxation in inhomogeneous magnetic field,"Transverse quasilinear relaxation of the cyclotron-Cherenkov instability in
+the inhomogeneous magnetic field of pulsar magnetospheres is considered. We
+find quasilinear states in which the kinetic cyclotron-Cherenkov instability of
+a beam propagating through strongly magnetized pair plasma is saturated by the
+force arising in the inhomogeneous field due to the conservation of the
+adiabatic invariant. The resulting wave intensities generally have nonpower law
+frequency dependence, but in a broad frequency range can be well approximated
+by the power law with the spectral index -2. The emergent spectra and fluxes
+are consistent with the one observed from pulsars.",9802026v1
+2005-01-14,Unidirectional Magnetostatic Waves,"Dispersion characteristics of magnetostatic waves in tangentially magnetized
+to saturation ferrite film with a ""magnetic wall"" condition (tangential
+component of microwave magnetic field is equal to zero) on the one of the film
+surface were calculated. It is found, that unidirectional magnetostatic waves
+appear in this geometry: they can transfer energy only in one direction and
+fundamentally cannot transfer energy in an opposite direction.",0501074v2
+2006-12-28,"Helicity fluctuation, generation of linking number and effect on resistivity","The energy of the stochastic magnetic field is bounded from below by a
+topological quantity expressing the degree of linkage of the field lines. When
+the bound is saturated one can assume that the storage of a certain magnetic
+energy requires a minimal degree of topological complexity. It is then possible
+to infer a connection between the helicity content and the average curvature of
+the magnetic field lines. The random curvature induce random drifts leading to
+an additional dissipation and modified resistivity.",0612248v1
+2007-04-05,Correlation functions and excitation spectrum of the frustrated ferromagnetic spin-1/2 chain in an external magnetic field,"Magnetic field effects on the one-dimensional frustrated ferromagnetic chain
+are studied by means of effective field theory approaches in combination with
+numerical calculations utilizing Lanczos diagonalization and the density matrix
+renormalization group method. The nature of the ground state is shown to change
+from a spin-density-wave region to a nematic-like one upon approaching the
+saturation magnetization. The excitation spectrum is analyzed and the behavior
+of the single spin-flip excitation gap is studied in detail, including the
+emergent finite-size corrections.",0704.0764v2
+2007-05-15,Excitation of MHD waves in magnetized anisotropic cosmologies,"The excitation of cosmological perturbations in an anisotropic cosmological
+model and in the presence of a homogeneous magnetic field was studied, using
+the resistive magnetohydrodynamic (MHD) equations. We have shown that
+fast-magnetosonic modes, propagating normal to the magnetic field grow
+exponentially and saturated at high values, due to the resistivity. We also
+demonstrate that the jeans-like instabilities are enhanced inside a resistive
+and the formation of condensations formed within an anisotropic fluid influence
+the growing magnetosonic waves.",0705.2194v1
+2008-06-12,Magnetic behavior of nanocrystalline LaMn2Ge2,"The compound, LaMn2Ge2, crystallizing in ThCr2Si2-type tetragonal crystal
+structure, has been known to undergo ferromagnetic order below (T_C=) 326 K. In
+this article, we report the magnetic behavior of nanocrystalline form of this
+compound, obtained by high-energy ball-milling. T_C of this compound is reduced
+maginally for the nanoform, whereas there is a significant reduction of the
+magnitude of the saturation magnetic moment with increasing milling time. The
+coercive field however increases with decreasing particle size. Thus, this work
+provides a route to tune these parameters by reducing the particle size in this
+ternary family.",0806.2030v1
+2008-07-07,Effective Theory of Magnetization Plateaux in the Shastry-Sutherland Lattice,"We use the non-perturbative Contractor-Renormalization method (CORE) in order
+to derive an effective model for triplet excitations on the Shastry-Sutherland
+lattice. For strong enough magnetic fields, various magnetization plateaux are
+observed, e.g. at 1/8, 1/4, 1/3 of the saturation, as found experimentally in a
+related compound. Moreover, other stable plateaux are found at 1/9, 1/6 or 2/9.
+We give a critical review of previous works and try to resolve some apparent
+inconsistencies between various theoretical approaches.",0807.1071v2
+2008-07-27,Magnetic-dipolar and electromagnetic vortices in quasi-2D ferrite disks,"Magnetic-dipolar-mode (MDM) oscillations in a quasi-2D ferrite disk show
+unique dynamical symmetry properties resulting in appearance of topologically
+distinct structures. Based on the magnetostatic (MS) spectral problem
+solutions, in this paper we give an evidence for eigen MS power-flow-density
+vortices in a ferrite disk. Due to these circular eigen power flows, the MDMs
+are characterized by MS energy eigen states. It becomes evident that the reason
+of stability of the vortex configurations in saturated ferrite samples is
+completely different from the nature of stability in magnetically soft
+cylindrical dots. We found a clear correspondence between analytically derived
+MDM vortex states and numerically modeled electromagnetic vortices in quasi-2D
+ferrite disks.",0807.4281v1
+2008-08-01,Asymmetric Magnetization Reversal in a Single Exchange-Biased Micro Bar,"The asymmetric magnetization reversal is studied in a single exchange-biased
+microbar of 1.5 x 13 micrometer with anisotropic magnetoresistance and magnetic
+force microscopy. The particle has a moment of less than 10^-9 emu and is not
+accessible with standard magnetometry. The asymmetric hysteresis loop of
+CoFe/CrMnPt shows a repeatable rotation process, followed by an irreversible
+nucleation process that is marked by jumps in the magnetoresistance. The
+induced unidirectional anisotropy enhances the rotation process in one branch
+of the hysteresis loop, followed by a sped up nucleation process. Imprinted
+ferromagnetic domain patterns left behind by the antiferromagnet are observed
+after the nucleation process occurred but before complete saturation is
+reached.",0808.0057v1
+2009-01-19,The ground state magnetic phase diagram of the ferromagnetic Kondo-lattice model,"The magnetic ground state phase diagram of the ferromagnetic Kondo-lattice
+model is constructed by calculating internal energies of all possible bipartite
+magnetic configurations of the simple cubic lattice explicitly. This is done in
+one dimension (1D), 2D and 3D for a local moment of S = 3/2. By assuming
+saturation in the local moment system we are able to treat all appearing higher
+local correlation functions within an equation of motion approach exactly. A
+simple explanation for the obtained phase diagram in terms of bandwidth
+reduction is given. Regions of phase separation are determined from the
+internal energy curves by an explicit Maxwell construction.",0901.2855v1
+2009-02-14,Relaxation of hole spins in quantum dots via two-phonon processes,"We investigate theoretically spin relaxation in heavy hole quantum dots in
+low external magnetic fields. We demonstrate that two-phonon processes and
+spin-orbit interaction are experimentally relevant and provide an explanation
+for the recently observed saturation of the spin relaxation rate in heavy hole
+quantum dots with vanishing magnetic fields. We propose further experiments to
+identify the relevant spin relaxation mechanisms in low magnetic fields.",0902.2457v1
+2009-06-23,Resistance fluctuations and 1/f noise in single crystalline Ni nanowires,"We measured the low frequency (10mHz < f < 10Hz) resistance fluctuations
+(Noise) in single crystalline ferromagnetic Ni nanowires (diameter ~35nm) in
+the temperature range 80K-300K. The noise spectral power shows 1/f dependence.
+The nanowires in an applied magnetic field show negative magetoresistance that
+saturates for H <= HC. The noise spectral power shows a reduction in low
+applied field and becomes field independent for H >= HC. This indicates that a
+part of the observed 1/f noise arises from magnetic origin. The magnetic part
+is associated with thermally activated domain wall fluctuations that couples to
+the resistance fluctuations.",0906.4227v1
+2010-05-10,Direct and inverse cascades in the geodynamo,"The rapid rotation of planets causes cyclonic thermal turbulence in their
+cores which may generate the large-scale magnetic fields observed outside the
+planets. We consider the model which enables us reproduce the typical features
+of small-scale geostrophic flows in physical and wave spaces. We present
+estimates of kinetic and magnetic energy fluxes as a function of the wave
+number. The joint existence of forward and inverse cascades are demonstrated.
+We also consider the mechanism of magnetic field saturation at the end of the
+kinematic dynamo regime.",1005.1546v1
+2010-08-30,Towards a quantum theory of chiral magnetic effect,"We discuss three possible ways to address quantum physics behind chiral
+magnetic effect and electric charge fluctuation patterns in heavy ion
+collisions. The first one makes use of P-parity violation probed by local order
+parameters, the second considers CME in quantum measurement theory framework
+and the third way is to study P-odd * P-odd contributions to P-even
+observables. In the latter approach relevant form-factor is extracted and
+computed for weak magnetic field in confinement region and for free quarks in
+strong field regime. It is shown that the effect is negligible in the former
+case. We also discuss saturation effect - charge fluctuation asymmetry for free
+fermions reaches constant value at asymptotically large fields.",1008.4977v1
+2010-11-29,Upper Critical Field in the Molecular Organic Superconductor (DMET)2I3,"We report the temperature dependence of the upper critical magnetic field in
+the quasi-onedimensional molecular organic superconductor (DMET)2I3, for
+magnetic field applied along the intrachain, interchain, and interplane
+directions. The upper critical field tends to saturation at low temperature for
+field in all directions and does not exceed the Pauli paramagnetic limit.
+Superconductivity in (DMET)2I3 thus appears to be conventional spin singlet, in
+contrast to the status of the isostructural Bechgaard salts. We also discuss a
+magnetic field-induced dimensional crossover effect in the normal metallic
+state which had previously appeared to be associated with superconductivity.",1011.6230v1
+2010-12-02,Hybrid metal-dielectric ring resonators for optical magnetic metamaterials down to ultraviolet range,"In this paper, we derive a model from Maxwell equations for the magnetic
+resonance of split-ring resonators. Using this model we revisit the scaling of
+split-ring resonators. Inspired by our model, we propose a new type of
+split-hybrid metal-dielectric ring resonator, of which the ring is made
+composed of moderately high index dielectric material (e.g. SiC, TiO2, ZnS)
+(for the major portion), while and metal (e.g. Ag) fills the gap. Such a new
+magnetic metamaterial is able to overcome the saturation problem of split-ring
+resonatorssaturation-free and therefore is able to operate at short wavelength
+down to ultraviolet range.",1012.0400v2
+2012-04-05,The influence of individual lattice defects on the domain structure in magnetic antidot lattices,"We numerically and experimentally investigate the influence of single defects
+consisting of a missing antidot on the spin configurations in rectangular
+permalloy antidot lattices. The introduction of such lattice defects leads to
+the nucleation of complex domain structures after the decay of a saturating
+magnetic field. Micromagnetic simulations yield four typical domain
+configurations around the defect having distinct energy densities. The
+existence of the four spin configurations is confirmed by magnetic force
+microscopy on antidot lattices containing individual defects.",1204.1183v2
+2012-07-10,Magnetic field induced localization in 2D topological insulators,"Localization of the helical edge states in quantum spin Hall insulators
+requires breaking time reversal invariance. In experiments this is naturally
+implemented by applying a weak magnetic field B. We propse a model based on
+scattering theory that describes the localization of helical edge states due to
+coupling to random magnetic fluxes. We find that the localization length is
+proportional to B^{2} when B is small, and saturates to a constant when B is
+sufficiently large. We estimate especially the localization length for the
+HgTe/CdTe quantum wells with known experimental parameters.",1207.2400v1
+2012-09-26,Ferromagnetic InMnAs on InAs Prepared by Ion Implantation and Pulsed Laser Annealing,"Ferromagnetic InMnAs has been prepared by Mn ion implantation and pulsed
+laser annealing. The InMnAs layer reveals a saturated magnetization of 2.6
+mu_B/Mn at 5 K and a perpendicular magnetic anisotropy. The Curie temperature
+is determined to be 46 K, which is higher than those in previous reports with
+similar Mn concentrations. Ferromagnetism is further evidenced by the large
+magnetic circular dichroism.",1209.5865v1
+2012-11-01,Spin Seebeck effect in antiferromagnets and compensated ferrimagnets,"We theoretically investigate the spin Seebeck effect (SSE) in
+antiferromagnets and ferrimagnets, and show that the SSE vanishes in
+antiferromagnets but survives in ferrimagnets even at the magnetization
+compensation point despite the absence of its saturation magnetization. The
+non-vanishing SSE in ferrimagnets stems from two non-degenerate magnons. We
+demonstrate that the magnitude of the SSE in ferrimagnets is unchanged across
+the magnetization compensation point.",1211.0123v1
+2013-02-02,Ground states of an Ising model on an extended Shastry-Sutherland lattice and the 1/2-magnetization plateau in some rare-earth-metal tetraborides,"A complete solution of the ground-state problem for an Ising model on the
+Shastry-Sutherland lattice with an additional interaction along the diagonals
+of ""empty"" squares in an applied magnetic field is presented. A rigorous proof
+is given that this interaction gives rise to a plateau at one-half of the
+saturation magnetization. Such a fractional plateau has been observed in some
+rare-earth-metal tetraborides, in particular, in strong Ising magnets ErB4
+(where it is the only one) and TmB4 (where it is the broadest one), but its
+origin has remained unclear. Our study sheds new light on the solution of this
+problem.",1302.0377v1
+2013-03-27,Magnetism driven ferroelectricity above liquid nitrogen temperature in Y2CoMnO6,"We report multiferroic behavior in double perovskite Y2CoMnO6 with
+ferroelectric transition temperature Tc = 80K. The origin of ferroelectricity
+is associated with magnetic ordering of Co2+ and Mn4+ moments in a
+up-up-down-down arrangement. The saturation polarization and magnetization are
+estimated to be 65 uC/m2 and 6.2 Bohr magneton/f.u. respectively. The
+magnetoelectric coupling parameter, on the other hand, is small as a 5 Tesla
+field suppresses the electric polarization by only ~8%. This is corroborated
+with observed hysteretic behaviour at 5K that remains unsaturated even upto 7
+Tesla. A model based on exchange-striction is proposed to explain the observed
+high temperature ferroelectricity.",1303.6921v1
+2014-07-16,Averaged effective pinning potential in YBCO single crystals close to Tc,"In this paper we present our results on the low density magnetic flux pinning
+characteristics, obtained though HTSC samples magnetization relaxation
+measurements M(t) near the phase transition temperatures (0,8 < T/Tc > 0,99).As
+the main object of investigation we have chosen pure YBa2Cu3O7-x (YBCO) single
+crystal samples with optimal oxygen saturation. We note the presence of strong
+pinning in the system of unidirectional planar defects and a significant
+nonmonotonicity of the Up(T) dependence behavior for low density trapped
+magnetic flux.",1407.4304v1
+2016-11-15,Numerical study of magnetization plateaux in the spin-1/2 Heisenberg antiferromagnet on the checkerboard lattice,"We present numerical evidence that the spin-1/2 Heisenberg model on the
+two-dimensional checkerboard lattice exhibits several magnetization plateaux
+for m=0, 1/4, 1/2 and 3/4, where m is the magnetization normalized by its
+saturation value. These incompressible states correspond to somehow similar
+valence-bond crystal phases that break lattice symmetries, though they are
+different from the already established plaquette phase for m=0. Our results are
+based on Exact Diagonalization as well as Density Matrix Renormalization Group
+large-scale simulations, and interpreted in terms of simple trial
+wavefunctions.",1611.04873v2
+2017-06-21,Quantum Phase Transition in the Twisted Three-Leg Spin Tube,"We investigate the spin-1/2 twisted three-leg antiferromagnetic quantum spin
+tube in the presence of the easy-plane anisotropy, using the numerical
+diagonalization of finite-size clusters. And we observe cases of the existence
+and the absence of magnetization plateau at 1/3 height of saturation
+magnetization when the anisotropy is tuned. The
+phenomenological-renormalization analysis indicates a quantum phase transition
+between the 1/3 magnetization plateau phase and the plateauless one. The phase
+diagram is also presented.",1706.06947v1
+2017-08-28,Evidence for field induced proximity type behavior in ferromagnetic nanofluid,"We report some unusual magnetic properties observed in CoFe2O4 based
+ferrofluid (with an average particle size of D = 6 nm). More precisely, in
+addition to the low-field ferromagnetic (FM) phase transition with an intrinsic
+Curie temperature T_Cb=350K, a second phase transition with an extrinsic Curie
+temperature T_Cw = 266K emerges at higher (saturating) magnetic field. The
+transitions meet at the crossover point T_cr = 210 K. The origin of the second
+transition is attributed to magnetic field induced proximity type interaction
+between FM particles through non-FM layers.",1708.08373v1
+2018-04-27,Angular Dependent Magnetization Dynamics with Mirror-symmetric Excitations in Artificial Quasicrystalline Nanomagnet Lattices,"We report angle-dependent spin-wave spectroscopy on aperiodic
+quasicrystalline magnetic lattices, i.e., Ammann, Penrose P2 and P3 lattices
+made of large arrays of interconnected Ni$_{80}$Fe$_{20}$ nanobars. Spin-wave
+spectra obtained in the nearly saturated state contain distinct sets of
+resonances with characteristic angular dependencies for applied in-plane
+magnetic fields. Micromagnetic simulations allow us to attribute detected
+resonances to mode profiles with specific mirror symmetries. Spectra in the
+reversal regime show systematic emergence and disappearance of spin wave modes
+indicating reprogrammable magnonic characteristics.",1804.10630v1
+2018-06-04,Magnetic field-tuned superconductor/insulator transition in TiN nanostrips,"We have measured the electric transport properties of TiN nanostrips with
+different widths. At zero magnetic field the temperature dependent resistance
+R(T) saturates at a finite resistance towards low temperatures, which results
+from quantum phase slips in the narrower strips. We find that the
+current-voltage (I-V) characteristics of the narrowest strips are equivalent to
+those of small Josephson junctions. Applying a transverse magnetic field drives
+the devices into a reentrant insulating phase, with I-V-characteristics dual to
+those in the superconducting regime. The results evidence that our critically
+disordered superconducting nanostrips behave like small self-organized random
+Josephson networks.",1806.01335v1
+2018-06-18,Large anomalous Nernst effect across the magneto-structural transition in bulk Ni-Co-Mn-Sn full Heusler alloy,"We report on the observation of temperature and field dependent anomalous
+Nernst effect (ANE) in Ni-rich bulk Ni-Co-Mn-Sn full Heusler alloy. A large
+change in the transverse Nernst coefficient (N) is obtained across the first
+order magnetostructural transition from a tetragonal martensite to a cubic
+austenite phase. The saturation of ANE and magnetic data appear to depend
+largely on the magnetic anisotropy of the device. Such change in the Nernst
+co-efficient may prove to be useful for switching applications controlled by
+temperature and magnetic field changes.",1806.06675v1
+2018-07-04,Control of multiferroic order by magnetic field in frustrated helimagnet MnI$_2$. Theory,"We provide a theoretical description of frustrated multiferroic $\rm MnI_2$
+with a spiral magnetic ordering in magnetic field $\bf h$. We demonstrate that
+subtle interplay of exchange coupling, dipolar forces, hexagonal anisotropy,
+and the Zeeman energy account for the main experimental findings observed
+recently in this material (Kurumaji, et al., Phys.\ Rev.\ Lett.\ {\bf 106},
+167206 (2011)). We describe qualitatively the non-trivial evolution of electric
+polarization $\bf P$ upon $\bf h$ rotation, changing $\bf P$ direction upon $h$
+increasing, and disappearance of ferroelectricity at $h>h_c$, where $h_c$ is
+smaller than the saturation field.",1807.01693v2
+2020-04-22,Experimental realization of Lieb-Mattis plateau in a quantum spin chain,"We present a mixed spin-(1/2, 5/2) chain composed of a charge-transfer salt
+(4-Br-$o$-MePy-V)FeCl$_4$. We observe the entire magnetization curve up to
+saturation, which exhibits a clear Lieb-Mattis magnetization plateau and
+subsequent quantum phase transition towards the gapless Luttinger-liquid phase.
+The observed magnetic behavior is quantitatively explained by a mixed
+spin-(1/2, 5/2) chain model. The present results demonstrate a quantum
+many-body effect based on quantum topology and provide a new stage in the
+search for topological properties in condensed matter physics.",2004.10416v1
+2020-08-10,Phase competition in frustrated anisotropic antiferromagnet in strong magnetic field,"We discuss theoretically a frustrated Heisenberg antiferromagnet in magnetic
+field close to the saturation one. It is demonstrated that a small biaxial
+anisotropy and/or the magnetic dipolar interaction produce a delicate balance
+between phases with a commensurate canted, incommensurate helical (conical),
+and fan spin orderings. As a result, different sequences of phase transitions
+are realized depending on values of these small anisotropic interactions. We
+derive analytical expressions for critical fields and ground-state energies of
+the phases which are in a quantitative agreement with our and previous
+Monte-Carlo simulations.",2008.04234v1
+2020-10-20,On the growth of the thermally modified non-resonant streaming instability,"The cosmic rays non-resonant streaming instability is believed to be the
+source of substantial magnetic field amplification. In this work we investigate
+the effects of the ambient plasma temperature on the instability and derive
+analytical expressions of its growth rate in the hot, demagnetized regime of
+interaction. To study its non-linear evolution we perform hybrid-PIC
+simulations for a wide range of temperatures. We find that in the cold limit
+about two-thirds of the cosmic rays drift kinetic energy is converted into
+magnetic energy. Increasing the temperature of the ambient plasma can
+substantially reduce the growth rate and the magnitude of the saturated
+magnetic field.",2010.10237v1
+2020-11-14,Gated two-dimensional electron gas in magnetic field: nonlinear versus linear regimes,"We study the effect of magnetic field on the properties of a high mobility
+gated two-dimensional electron gas in a field effect transistor with the Hall
+bar geometry. When approaching the current saturation when the drain side of
+the channel becomes strongly depleted, we see a number of unusual effects
+related to the magnetic field induced re-distribution of the electron density
+in the conducting channel. The experimental results obtained in the non-linear
+regime have been interpreted based on the results obtained in the linear regime
+by a simple theoretical model, which describes quite well our observations.",2011.07292v1
+2021-11-04,Sequence of superconducting states in field cooled $FeCr_2S_4$,"In the present article we discuss theoretically the emergence of
+superconductivity in field cooled $FeCr_2S_4$. The chromium electrons form a
+triplet $t_{2g}$ states and due to antiferromagnetic exchange with the iron
+spins have Zeeman splitting. Applied, during preparation, magnetic field along
+the moment of iron ions, successively compensates the Zeeman splittings. The
+chromium electrons with zero Zeeman energy form Cooper pairs induced by iron
+magnons. In that way, we predict theoretically the existence of sequence of
+superconducting states in field cooled $FeCr_2S_4$. Actually there are three
+different superconductors prepared applying, during preparation, different
+magnetic fields. In these compounds superconductivity coexist with the
+saturated magnetism of iron ions.",2111.02765v1
+2022-05-14,Magnetization Plateau of the Distorted Diamond Spin Chain with Anisotropic Ferromagnetic Interaction,"The $S=1/2$ distorted diamond spin chain with the anisotropic ferromagnetic
+interaction is investigated using the numerical diagonalization and the level
+spectroscopy analysis. It is known that the system exhibits a plateau of the
+magnetization curve at the 1/3 of the saturation. The present study indicates
+that as the anisotropy is varied the quantum phase transition occurs between
+two different mechanisms of the 1/3 magnetization plateau. The phase diagram
+with respect to the anisotropy and the ferromagnetic coupling is also
+presented.",2205.07027v1
+2023-05-22,Skyrmions and antiskyrmions in monoaxial chiral magnets,"We show that competition between local interactions in monoaxial chiral
+magnets provides the stability of two-dimensional (2D) solitons with identical
+energies but opposite topological charges. These skyrmions and antiskyrmions
+represent metastable states in a wide range of parameters above the transition
+into the saturated ferromagnetic phase. The symmetry of the underlying
+micromagnetic functional gives rise to soliton zero modes allowing efficient
+control of their translational movement by the frequency of the circulating
+external magnetic field. We also discuss the role of demagnetizing fields in
+the energy balance between skyrmion and antiskyrmion and in their stability.",2305.13003v1
+2000-01-10,The Effect of Resistivity on the Nonlinear Stage of the Magnetorotational Instability in Accretion Disks,"We present three-dimensional magnetohydrodynamic simulations of the nonlinear
+evolution of the magnetorotational instability (MRI) with a non-zero Ohmic
+resistivity. The properties of the saturated state depend on the initial
+magnetic field configuration. In simulations with an initial uniform vertical
+field, the MRI is able to support angular momentum transport even for large
+resistivities through the quasi-periodic generation of axisymmetric radial
+channel solutions rather than through the maintenance of anisotropic
+turbulence. Simulations with zero net flux show that the angular momentum
+transport and the amplitude of magnetic energy after saturation are
+significantly reduced by finite resistivity, even at levels where the linear
+modes are only slightly affected. This occurs at magnetic Reynolds numbers
+expected in low, cool states of dwarf novae, these results suggest that finite
+resistivity may account for the low and high angular momentum transport rates
+inferred for these systems.",0001164v1
+1998-06-24,Magnetization plateaus in weakly coupled dimer spin system,"I study a spin system consisting of strongly coupled dimers which are in turn
+weakly coupled in a plane by zigzag interactions. The model can be viewed as
+the strong-coupling limit of a two-dimensional zigzag chain structure typical,
+e.g., for the $(ac)$-planes of KCuCl_3. It is shown that the magnetization
+curve in this model has plateaus at 1/3 and 2/3 of the saturation
+magnetization, and an additional plateau at 1/2 can appear in a certain range
+of the model parameters; the critical fields are calculated perturbatively. It
+is argued that for the three-dimensional lattice structure of the KCuCl_3
+family the plateaus at 1/4 and 3/4 of the saturation can be favored in a
+similar way, which might be relevant to the recent experiments on NH_4CuCl_3 by
+Shiramura et al., J. Phys. Soc. Jpn. {\bf 67}, 1548 (1998).",9806292v3
+2003-06-11,Electron Coherence in Mesoscopic Kondo Wires,"We present measurements of the magnetoresistance of long and narrow quasi
+one-dimensional gold wires containing magnetic iron impurities. The electron
+phase coherence time extracted from the weak antilocalisation shows a
+pronounced plateau in a temperature region of 300 mK - 800 mK, associated with
+the phase breaking due to the Kondo effect. Below the Kondo temperature, the
+phase coherence time increases, as expected in the framework of Kondo physics.
+At much lower temperatures, the phase coherence time saturates again, in
+contradiction with standard Fermi liquid theory. In the same temperature
+regime, the resistivity curve displays a characteristic maximum at zero
+magnetic field, associated with the formation of a spin glass state. We argue
+that the interactions between the magnetic moments are responsible for the low
+temperature saturation of the phase coherence time.",0306276v1
+2003-08-14,Low temperature dephasing saturation from elastic magnetic spin disorder and interactions,"We treat the question of the low temperature behavior of the dephasing rate
+of the electrons in the presence of elastic spin disorder scattering and
+interactions. In the frame of a self-consistent diagrammatic treatment, we
+obtain saturation of the dephasing rate in the limit of low temperature for
+magnetic scattering, in agreement with the non-interacting case. The magnitude
+of the dephasing rate is set by the strength of the magnetic scattering rate.
+We discuss the agreement of our results with relevant experiments.",0308300v7
+2003-11-13,"Structural, magnetic and transport properties of thin films of the Heusler alloy Co2MnSi","Thin films of Co2MnSi have been grown on a-plane sapphire substrates from
+three elemental targets by dc magnetron co-sputtering. These films are single
+phase, have a strong (110) texture and a saturation magnetization of 4.95
+uB/formula unit at 10 K. Films grown at the highest substrate temperature of
+715 K showed the lowest resistivity (47 uOhm cm at 4.2 K) and the lowest
+coercivity (18 Oe). The spin polarization of the transport current was found to
+be of the order of 54% as determined by point contact Andreev reflection
+spectroscopy. A decrease in saturation magnetization with decreasing film
+thickness and different transport behaviour in thinner films indicate a graded
+disorder in these films grown on non-lattice matched substrates.",0311316v1
+2003-12-02,Frustrated antiferromagnets at high fields: the Bose-Einstein condensation in degenerate spectra,"Quantum phase transition at the saturation field is studied for a class of
+frustrated quantum antiferromagnets. The considered models include (i) the
+$J_1$-$J_2$ frustrated square-lattice antiferromagnet with $J_2={1/2}J_1$ and
+(ii) the nearest-neighbor Heisenberg antiferromagnet on a face centered cubic
+lattice. In the fully saturated phase the magnon spectra for the two models
+have lines of degenerate minima. Transition into partially magnetized state is
+treated via a mapping to a dilute gas of hard core bosons and by complementary
+spin-wave calculations. Momentum dependence of the exact four-point boson
+vertex removes the degeneracy of the single-particle excitation spectra and
+selects the ordering wave-vectors at $(\pi,\pi)$ and $(\pi,0,0)$ for the two
+models. The asymptotic behavior of the magnetization curve differs
+significantly from that of conventional antiferromagnet in $d$-spatial
+dimensions. We predict a unique form for the magnetization curve $\Delta
+M=S-M\simeq \mu^{(d-1)/2}(\log\mu)^{(d-1)}$, where $\mu$ is a distance from the
+quantum critical point.",0312076v2
+2005-09-21,Bose-Einstein condensation of magnons in Cs$_{2}$CuCl$_{4}$: a dilute gas limit near the saturation magnetic field,"Based on a realistic spin Hamiltonian for a frustrated quasi-two dimensional
+spin-1/2 antiferromagnet Cs$_{2}$CuCl$_{4}$, a three-dimensional spin ordering
+in the applied magnetic field $B$ near the saturation value $B_{c}$ is studied
+within the magnon Bose-Einstein condensation (BEC) scenario. With the use of a
+hard-core boson formulation of the spin model, a strongly anysotropic magnon
+dispersion in Cs$_{2}$CuCl$_{4}$ is calculated. In the dilute magnon limit near
+$B_{c}$, the hard-core boson constraint is resulted in an effective magnon
+interaction which is treated in the Hartree-Fock approximation. The critical
+temperature $T_{c}$ is calculated as a function of a magnetic field $B$ and
+compared with the phase boundary $T_{c}(B) $ experimentally determined in
+Cs$_{2}$CuCl$_{4}$ [Phys. Rev. Lett. \textbf{95}, 127202 (2005)].",0509552v1
+2006-06-22,Enhanced low field magnetoresistance of Fe3O4 nano-sphere compact,"Unusually large low field magetoresistance (LFMR), ~ 10 %, at 300 K has been
+observed with the sample of mono-dispersed Fe3O4 magnetite nanospheres, ~ 200
+nm, compactly cold-pressed and sintered at 800 C. A detailed analysis on the
+transport and magnetic measurements indicates that the electron conduction is
+dominated by the spin-dependent scattering or tunneling at the grain
+boundaries. At low temperature, 140 K and 100 K near the Verwey transition, ~
+115 K, the LFMR (below 2 kOe) does not show any sign of dependence on the
+transition, and does not follow the variation of magnetization to reach the
+saturation region either. On the other hand, at 300 K, the MR saturates fast
+with the magnetization below 2 kOe. This temperature dependent property in LFMR
+is very likely attributed to the scattering or tunneling of the conduction
+electron passing through the grain boundary layer with spin disordered state.",0606565v1
+2007-05-22,Magnetocaloric effect in the frustrated square lattice J1-J2 model,"We investigate the magnetocaloric properties of the two-dimensional
+frustrated J1-J2 model on a square lattice. This model describes well the
+magnetic behavior of two classes of quasi-two-dimensional S = 1/2 vanadates,
+namely the Li2VOXO4 (X = Si, Ge) and AA'VO(PO4)2 (A, A' = Pb, Zn, Sr, Ba)
+compounds. The magnetocaloric effect (MCE) consists in the adiabatic
+temperature change upon changing the external magnetic field. In frustrated
+systems, the MCE can be enhanced close to the saturation field because of
+massive degeneracies among low lying excitations. We discuss results for the
+MCE in the two distinct antiferromagnetic regimes of the phase diagram.
+Numerical finite temperature Lanczos as well as analytical methods based on the
+spin wave expansion are employed and results are compared. We give explicit
+values for the saturation fields of the vanadium compounds. We predict that at
+subcritical fields there is first a (positive) maximum followed by sign change
+of the MCE, characteristic of all magnetically ordered phases.",0705.3094v2
+2008-11-12,Spin-Dynamics of the antiferromagnetic S=1/2-Chain at finite magnetic Fields and intermediate Temperatures,"We present a study of the dynamic structure factor of the antiferromagnetic
+spin-1/2 Heisenberg chain at finite temperatures and finite magnetic fields.
+Using Quantum-Monte-Carlo based on the stochastic series expansion and
+Maximum-Entropy methods we evaluate the longitudinal and the transverse dynamic
+structure factor from vanishing magnetic fields up to and above the threshold
+$B_c$ for ferromagnetic saturation, as well as for high and for intermediate
+temperatures. We study the field-induced redistribution of spectral weight
+contrasting longitudinal versus transverse excitations. At finite fields below
+saturation incommensurate low-energy modes are found consistent with zero
+temperature Bethe-Ansatz. The crossover between the field induced ferromagnet
+above $B_c$ and the Luttinger liquid below $B_c$ is analyzed in terms of the
+transverse spin-dynamics. Evaluating sum-rules we assess the quality of the
+analytic continuation and demonstrate excellent consistency of the
+Maximum-Entropy results.",0811.1956v2
+2009-03-13,Magnetoconductivity of low-dimensional disordered conductors at the onset of the superconducting transition,"Magnetoconductivity of the disordered two- and three-dimensional
+superconductors is addressed at the onset of superconducting transition. In
+this regime transport is dominated by the fluctuation effects and we account
+for the interaction corrections coming from the Cooper channel. In contrast to
+many previous studies we consider strong magnetic fields and various
+temperature regimes, which allow to resolve the existing discrepancies with the
+experiments. Specifically, we find saturation of the fluctuations induced
+magneto-conductivity for both two- and three-dimensional superconductors at
+already moderate magnetic fields and discuss possible dimensional crossover at
+the immediate vicinity of the critical temperature. The surprising observation
+is that closer to the transition temperature weaker magnetic field provides the
+saturation. It is remarkable also that interaction correction to
+magnetoconductivity coming from the Cooper channel, and specifically the so
+called Maki-Thompson contribution, remains to be important even away from the
+critical region.",0903.2467v2
+2009-04-18,From fibril to diffuse fields during dynamo saturation,"The degree of intermittency of the magnetic field of a large-scale dynamo is
+considered. Based on simulations it is argued that there is a tendency for the
+field to become more diffuse and non-intermittent as the dynamo saturates. The
+simulations are idealized in that the turbulence is strongly helical and shear
+is strong, so the tendency for the field to become more diffuse is somewhat
+exaggerated. Earlier results concerning the effects of magnetic buoyancy are
+discussed. It is emphasized that the resulting magnetic buoyancy is weak
+compared with the stronger effects of simultaneous downward pumping. These
+findings are used to support the notion that the solar dynamo might operate in
+a distributed fashion where the near-surface shear layer could play an
+important role.",0904.2842v1
+2009-05-14,PIC simulations of the Thermal Anisotropy-Driven Weibel Instability: Field growth and phase space evolution upon saturation,"The Weibel instability is investigated with PIC simulations of an initially
+unmagnetized and spatially uniform electron plasma. This instability, which is
+driven by the thermally anisotropic electron distribution, generates
+electromagnetic waves with wave vectors perpendicular to the direction of the
+higher temperature. Two simulations are performed: A 2D simulation, with a
+simulation plane that includes the direction of higher temperature,
+demonstrates that the wave spectrum is initially confined to one dimension. The
+electric field components in the simulation plane generated by the instability
+equalize at the end of the simulation through a secondary instability. A 1D PIC
+simulation with a high resolution, where the simulation box is aligned with the
+wave vectors of the growing waves, reveals details of the electron phase space
+distribution and permits a comparison of the magnetic and electric fields when
+the instability saturates. It is shown that the electrostatic field is driven
+by the magnetic pressure gradient and that it and the magnetic field
+redistribute the electrons in space.",0905.2282v1
+2009-12-01,Heavy Fermion-like metal alpha double prime-Fe16N2 with giant saturation magnetization,"A new model is proposed for the strong ferromagnetism associated with
+partially localized orbitals in the Fe16N2 metallic system which draws
+substantially from models of heavy fermion metals. We demonstrated that an
+unusual correlation effect is brought up within the Fe-N octahedral cluster
+region and the effective on-site 3d-3d Coulomb interaction increases due to a
+substantial 3d electrons charge density difference between the clusters and its
+surroundings, which leads to a partially localized high spin electron
+configuration with a long range ferromagnetic order. First principle
+calculation based on LDA+U method shows that giant magnetic moment can be
+achieved at sufficiently large Hubbard U value. The feature of the coexistence
+of the localized and itinerant electron states plays a key role on the
+formation of the giant saturation magnetization.",0912.0276v1
+2010-05-31,Can catastrophic quenching be alleviated by separating shear and alpha effect?,"The small-scale magnetic helicity produced as a by-product of the large-scale
+dynamo is believed to play a major role in dynamo saturation. In a mean-field
+model the generation of small-scale magnetic helicity can be modelled by using
+the dynamical quenching formalism. Catastrophic quenching refers to a decrease
+of the saturation field strength with increasing Reynolds number. It has been
+suggested that catastrophic quenching only affects the region of non-zero
+helical turbulence (i.e. where the kinematic alpha operates) and that it is
+possible to alleviate catastrophic quenching by separating the region of strong
+shear from the alpha layer. We perform a systematic study of a simple
+axisymmetric two-layer alpha-omega dynamo in a spherical shell for Reynolds
+numbers in the range 1 < Rm < 10^5. In the framework of dynamical quenching we
+show that this may not be the case, suggesting that magnetic helicity fluxes
+would be necessary.",1005.5708v1
+2010-10-09,The High Field Magnetization in the RF Sputter Deposited Copper Ferrite Thin Films,"Copper ferrite thin films were deposited on amorphous quartz substrates. The
+as deposited films were annealed in air and either quenched or slow cooled.
+Magnetization studies were carried out on the as deposited as well as annealed
+films using a SQUID magnetometer. The M-H curves were measured up to a field of
+7T, at temperatures varying from 5K to 300K. The magnetization in the films did
+not saturate, even at the highest field. The expression, M(H)= Q(1- a/H^n)
+fitted the approach to saturation best with n=1/2, for all films and at all
+temperatures. The coefficient a was the highest for the as deposited film and
+was the smallest for the quenched film. In the case of as deposited film, the
+value of coefficient a increased with increasing temperature, while for the
+annealed films, the value of a showed a decrease as temperature increases.",1010.1881v1
+2012-11-02,Polarized neutron reflectometry study of Fe16N2 with Giant Saturation Magnetization prepared by N Inter-diffusion in Annealed Fe-N Thin Films,"We report a synthesis route to grow iron nitride thin films with giant
+saturation magnetization (Ms) through an N inter-diffusion process. By post
+annealing Fe/Fe-N structured films grown on GaAs(001) substrates, nitrogen
+diffuses from the over-doped amorphous-like Fe-N layer into strained
+crystalline Fe layer and facilitates the development of metastable Fe16N2
+phase. As explored by polarized neutron reflectometry, the depth-dependent Ms
+profile can be well described by a model with the presence of a giant Ms up to
+2360 emu/cm3 at near-substrate interface, corresponding to the strained regions
+of these annealed films. This is much larger than the currently known limit
+(Fe65Co35 with Ms \sim 1900 emu/cm3). The present synthesis method can be used
+to develop writer materials for future magnetic recording application.",1211.0551v1
+2012-12-19,Realizing a High Magnetic Moment in Gd/Cr/FeCo: The Role of the Rare Earth,"The search for materials or systems exhibiting a high magnetic saturation has
+been of longstanding importance. It has been suggested that increased
+saturation could be achieved by coupling a transition metal via a spacer to a
+rare earth. We report Gd/Cr/Fe70Co30 multilayer stacks and find reduced yet
+modulating magnetic moment as a function of Cr thickness. Through a micro
+structural analysis the lowered moment is indicated by the nucleation of the
+ultrathin Gd films into an fcc phase. We discuss the possible solution in terms
+of quasi-perfect lattice match seed material to promote growth of hcp Gd.",1212.4859v1
+2013-05-28,Magnonic band gaps in waveguides with a periodic variation of the saturation magnetization,"We present a micromagnetic analysis of spin-wave propagation in a magnonic
+crystal realized as a permalloy spin-wave waveguide with a spatial periodical
+variation of its saturation magnetization. Frequency band gaps were clearly
+observed in the spin-wave transmission spectra and their origin is traced back
+to an overlap of individual band gaps of the fundamental and the higher order
+spin-wave width modes. The control of the depth, width and the position in
+frequency and space of the rejection band gaps by the width areas with a
+reduced magnetization and by the modulation level, are discussed in this study.",1305.6619v1
+2013-10-28,Temperature dependent weak value of dwell time for a two state particle tunneling through a thermal magnetic barrier,"Dwell time for a two state particle tunneling through a noisy thermal
+magnetic barrier has been calculated by studying the time evolution of the
+system. The effect of temperature has been included by averaging over the
+environmental magnetic modes. The time scale has been calculated in the
+framework of weak measurement. The dwell time initially increases with the rise
+of temperature and finally saturates. The increment of dwell time can be
+explained by the phenomena of quantum memory loss caused by efficient energy
+exchange with the environmental modes. The saturation region at higher
+temperature corresponds to the process of thermal hopping of the barrier.",1310.7338v2
+2014-01-23,Saturated-absorption spectroscopy revisited: atomic transitions in strong magnetic fields ($>$20 mT) with a micrometer-thin cell,"The existence of cross-over resonances makes saturated-absorption spectra
+very complicated when external magnetic field B is applied. It is demonstrated
+for the first time that the use of micrometric-thin cells (MTC,
+$L\approx40\,\mu$m) allows application of SA for quantitative studies of
+frequency splittings and shifts of the Rb atomic transitions in a wide range of
+external magnetic fields, from 0.2 up to 6 kG (20-600 mT). We compare the SA
+spectra obtained with the MTC with those obtained with other techniques, and
+present applications for optical magnetometry with micrometer spatial
+resolution and a broadly tunable optical frequency reference.",1401.6208v2
+2014-05-05,The change of GRB polarization angles in the magnetic-dominated jet model,"The polarimetric measurement on the prompt phase of GRB 100826A shows that
+the polarization angle changes $\sim 90^{\circ}$ between two adjacent time
+intervals. We will show that this phenomenon can be naturally interpreted in
+the framework of the magnetic-dominated jet (MDJ) model. The MDJ model suggests
+that the bulk Lorentz factor of the outflow increases as $\Gamma\propto
+r^{1/3}$, until reaching a saturated value $\Gamma_{\rm sat}$. Electrons move
+in the globally ordered magnetic field advected by the jet from the central
+engine and produce synchrotron photons. The polarized synchrotron photons
+travel alone the jet direction and then collide with the cold electrons at the
+front of the jet. After the Compton scattering process, these photons escape
+from the jet and are detected by the observer locating slightly off-axis. If
+photons are emitted before the bulk Lorentz factor saturates, the change of
+polarization angle is a natural result of the acceleration of the outflow.",1405.0844v2
+2015-09-07,Influence of spin dynamics of defects on weak localization in paramagnetic 2D metals,"Spin-flip scattering of charge carriers in metals with magnetic defects leads
+to the low-temperature saturation of the decoherence time, $\tau_\varphi$, of
+electrons at the value comparable to their spin relaxation time, $\tau_s$. In
+two-dimensional (2D) conductors such a saturation can be lifted by an in-plane
+magnetic field, $B_\parallel$, which polarizes spins of scatterers without
+affecting orbital motion of free carriers. Here, we show that in 2D conductors
+with substantially different values of the g-factors of electrons ($g_e$) and
+magnetic defects ($g_i$), the decoherence time $\tau_\varphi(B_\parallel)$
+(reflected by the curvature of magnetoconductance) displays an anomaly: it
+first gets shorter, decaying on the scale $B_\parallel\sim \hbar/|g_i-g_e|\mu_B
+\tau_s$, before becoming longer at higher values of $B_\parallel$.",1509.01955v2
+2015-10-07,"Tunable damping, saturation magnetization, and exchange stiffness of half-Heusler NiMnSb thin films","The half-metallic half-Heusler alloy NiMnSb is a promising candidate for
+applications in spintronic devices due to its low magnetic damping and its rich
+anisotropies. Here we use ferromagnetic resonance (FMR) measurements and
+calculations from first principles to investigate how the composition of the
+epitaxially grown NiMnSb influences the magnetodynamic properties of saturation
+magnetization $M_S$, Gilbert damping $\alpha$, and exchange stiffness $A$.
+$M_S$ and $A$ are shown to have a maximum for stoichiometric composition, while
+the Gilbert damping is minimum. We find excellent quantitative agreement
+between theory and experiment for $M_S$ and $\alpha$. The calculated $A$ shows
+the same trend as the experimental data, but has a larger magnitude.
+Additionally to the unique in-plane anisotropy of the material, these
+tunabilities of the magnetodynamic properties can be taken advantage of when
+employing NiMnSb films in magnonic devices.",1510.01894v1
+2016-02-19,Complete mapping of the spin-wave spectrum in vortex state nano-disk,"We report a study on the complete spin-wave spectrum inside a vortex state
+nano-disk. Transformation of this spectrum is continuously monitored as the
+nano-disk becomes gradually magnetized by a perpendicular magnetic field and
+encouters a second order phase transition to the uniformly magnetized state.
+This reveals the bijective relationship that exists between the eigen-modes in
+the vortex state with the ones in the saturated state. It is found that the
+gyrotropic mode can be continuously viewed as a uniform phase precession, which
+uniquely softens (its frequency vanishes) at the saturation field to transform
+above into the Kittel mode. By contrast the other spin-wave modes remain finite
+as a function of the applied field while their character is altered by level
+anti-crossing.",1602.06336v2
+2016-07-01,Saturation magnetization and band gap tuning in BiFeO$_3$ nanoparticles via co-substitution of Gd and Mn,"In this investigation, Gd and Mn co-doped
+Bi$_{0.85}$Gd$_{0.15}$Fe$_{1-x}$Mn$_x$O$_3$ (x=0.0-0.15) nanoparticles have
+been prepared to report the influence of co-substitution on their structural,
+optical, magnetic and electrical properties. Due to simultaneous substitution
+of Gd and Mn in BiFeO$_3$, the crystal structure has been modified from
+rhombohedral (R3c) to orthorhombic (Pn21a) and the Fe-O-Fe bond angle and Fe-O
+bond length have been changed. For Mn doping up to 10 % in
+Bi$_{0.85}$Gd$_{0.15}$Fe$_{1-x}$Mn$_x$O$_3$ nanoparticles, the saturation
+magnetization (Ms) has been enhanced significantly, however, for a further
+increase of doping up to 15 %, the Ms has started to reduce again. The
+co-substitution of Gd and Mn in BiFeO$_3$ nanoparticles also demonstrates a
+strong reduction in the optical band gap energy and electrical resistivity
+compared to that of undoped BiFeO$_3$.",1607.00158v1
+2017-05-18,Enhanced Ferromagnetism in Lacey Reduced Graphene Oxide Nano-ribbon,"Incorporation of magnetism in graphene based compounds holds great promise
+for potential spintronic applications. By optimizing point defects and high
+edge density of defects, we report many-fold increase in the ferromagnetic
+saturation moment in lacey reduced graphene oxide nanoribbons (LRGONR) as
+compared to other graphene derivatives. The samples were synthesized using
+chemical unzipping methodology. Detailed structural and morphological
+characterizations are discussed that include XRD, Raman, SEM, HRTEM and XPS
+measurements. Brilluoin function analysis to magnetization data reflects best
+fit for J = 7/2 with a saturation moment of 1.1 emu/g. The microscopic origin
+of magnetization in LRGONR is assigned to high edge defect density which has
+also been correlated to microstructure.",1705.06531v1
+2018-01-23,"Polyaniline (C_{3}N) nanoribbons: Magnetic metal, Semiconductor, and Half-Metal","Two-dimensional polyaniline sheet has been recently synthesized and found
+that it is a semiconductor with indirect band gap. Polyaniline nanoribbons
+decomposed from two-dimensional polyaniline sheet (C3N sheet) are investigated
+using density functional theory. The existence of nitrogen atoms in the edge of
+the ribbons increases stability and magnetization of the ribbons and make them
+different from graphene nanoribbons. Unsaturated nanoribbons are magnetic
+metals so that armchair C3N nanoribbons are gap-less spin semicon- ductors in
+the antiferromagnetic state and half-metals in the ferromagnetic state. A
+transition from metal to semiconductor is observed in the armchair C3N
+nanoribbons when the edge atoms are passivated by hy- drogen. The band gap of
+hydrogen saturated armchair C3N nanoribbons can be controlled using an external
+transverse electric field so that its magnitude is dependent on the direction
+of the electric field. Being metal or semiconductor in hydrogen saturated
+zigzag C3N nanoribbons is strongly dependent on the edge atoms so that just
+ribbons having nitrogen atoms in both edges are semiconductor. An external
+electric field cannot induce any spin polarization in the zigzag nanoribbons
+which is in contrast with what was observed in zigzag",1801.07540v2
+2018-09-19,Structure-property relationship of Co$_2$MnSi thin films in response to He$^+$ -irradiation,"We investigated the structure-property relationship of Co$_2$MnSi Heusler
+thin films upon the irradiation with He$^+$ ions. The variation of the crystal
+structure with increasing ion fluence has been probed using nuclear magnetic
+resonance (NMR) and transmission electron microscopy (TEM), and associated with
+the corresponding changes of the magnetic behavior. A decrease of both the
+structural order and the moment in saturation is observed. Specifically, we
+detect a direct transition from a highly $L2_1$-ordered to a fully
+$A2$-disordered structure type and quantify the evolution of the $A2$
+structural contribution as a function of ion fluence. Complementary TEM
+analysis reveals a spatially-resolved distribution of the $L2_1$ and $A2$
+phases showing that the $A2$ disorder starts at the upper part of the films.
+The structural degradation in turn leads to a decreasing magnetic moment in
+saturation in response to the increasing fluence.",1809.07097v1
+2018-11-06,Phase programming in coupled spintronic oscillators,"Neurons in the brain behave as a network of coupled nonlinear oscillators
+processing information by rhythmic activity and interaction. Several
+technological approaches have been proposed that might enable mimicking the
+complex information processing of neuromorphic computing, some of them relying
+on nanoscale oscillators. For example, spin torque oscillators are promising
+building blocks for the realization of artificial high-density, low-power
+oscillatory networks (ON) for neuromorphic computing. The local external
+control and synchronization of the phase relation of oscillatory networks are
+among the key challenges for implementation with nanotechnologies. Here we
+propose a new method of phase programming in ONs by manipulation of the
+saturation magnetization, and consequently the resonance frequency of a single
+oscillator via Joule heating by a simple DC voltage input. We experimentally
+demonstrate this method in a pair of stray field coupled magnetic vortex
+oscillators. Since this method only relies on the oscillatory behavior of
+coupled oscillators, and the temperature dependence of the saturation
+magnetization, it allows for variable phase programming in a wide range of
+geometries and applications that can help advance the efforts of high frequency
+neuromorphic spintronics up to the GHz regime.",1811.02154v1
+2019-10-08,Analytic solutions of the modified Langevin equation in a mean-field model,"Approximate analytical solutions of the modified Langevin equation are
+obtained. These solutions are relatively simple and enough accurate. They are
+illustrated by considering a mean-field model of a system with interacting
+superparamagnetic particles. Within the framework of this model system we
+derived analytical approximate formulas for the temperature dependencies of the
+saturation and remnant magnetization, coercive force, initial magnetic
+susceptibility as well as for the law of approach to saturation. We obtained
+also some exact analytical relationships for the coercive force. We found
+remarkable similarity between the approximate cubic equation, which is resulted
+from the modified Langevin equation, and the exact equation resulting from the
+divergence condition of a solution derivative. The analytical formulas obtained
+in this work can be used in various models (not only magnetic ones), where the
+modified Langevin equation is applied.",1910.08401v1
+2020-05-20,Correlating magnetic structure and magnetotransport in semimetal thin films of Eu$_{1-x}$Sm$_x$TiO$_3$,"We report on the evolution of the average and depth-dependent magnetic order
+in thin film samples of biaxially stressed and electron-doped EuTiO$_3$ for
+samples across a doping range $<$0.1 to 7.8 $\times 10^{20}$ cm$^{-3}$. Under
+an applied in-plane magnetic field, the G-type antiferromagnetic ground state
+undergoes a continuous spin-flop phase transition into in-plane,
+field-polarized ferromagnetism. The critical field for ferromagnetism slightly
+decreases with an increasing number of free carriers, yet the field evolution
+of the spin-flop transition is qualitatively similar across the doping range.
+Unexpectedly, we observe interfacial ferromagnetism with saturated Eu$^{2+}$
+moments at the substrate interface at low fields preceding ferromagnetic
+saturation throughout the bulk of the degenerate semiconductor film. We discuss
+the implications of these findings for the unusual magnetotransport properties
+of this compound.",2005.10339v1
+2020-07-23,Effect of external electromagnetic radiation on the anomalous metallic behaviors in Ta thin films,"We investigated transport characteristics of superconducting Ta thin films
+with three configurations in rf radiation filters; no filter, only
+room-temperature filters, and low-temperature filters in addition to
+room-temperature filters. The transport properties near the transition
+temperature are strongly dependent on whether the room-temperature filter is
+installed or not. The entire transition is shifted to higher temperature with
+loading layers of the room-temperature filters. Once the zero-resistance state
+is achieved at B=0, no strong radiation effect is observed even with
+low-temperature filters installed. When magnetic field is turned on, the
+nonzero-resistance saturation at low temperatures is revealed without
+low-temperature filters, which has been considered to be magnetic-field-induced
+quantum metallic phase. However, the insertion of the additional
+low-temperature filter weakens the saturation of the resistance, the signature
+of the metallic behavior. This observation suggests that the previously
+reported anomalous metallic state in Ta films is mainly induced by the
+unfiltered radiation and, thus, the intrinsic metallic ground state should be
+limited to the narrow range of magnetic fields near the critical point, if
+exists.",2007.11923v1
+2020-08-21,Robust anomalous metallic states and vestiges of self duality in two-dimensional granular In-InOx composites,"Many experiments investigating magnetic field tuned superconductor-insulator
+transition (H-SIT), often exhibit low-temperature resistance saturation, which
+is interpreted as an anomalous metallic phase emerging from a ""failed
+superconductor,"" thus challenging conventional theory. Here we study a random
+granular array of indium islands grown on a gateable layer of indium-oxide. By
+tuning the intergrain couplings, we reveal a wide range of magnetic fields
+where resistance saturation is observed, under conditions of careful
+electromagnetic filtering and within a wide range of linear response. Exposure
+to external broadband noise or microwave radiation is shown to strengthen the
+tendency of superconductivity, where at low field a global superconducting
+phase is restored. Increasing magnetic field unveils an ""avoided H-SIT,"" that
+exhibits granularity-induced logarithmic divergence of the
+resistance/conductance above/below that transition, pointing to possible
+vestiges of the original emergent duality observed in a true H-SIT. We conclude
+that anomalous metallic phase is intimately associated with inherent
+inhomogeneities, exhibiting robust behavior at attainable temperatures for
+strongly granular two-dimensional systems.",2008.09325v2
+2020-11-19,Measurements of the growth and saturation of electron Weibel instability in optical-field ionized plasmas,"The temporal evolution of the magnetic field associated with electron thermal
+Weibel instability in optical-field ionized plasmas is measured using
+ultrashort (1.8 ps), relativistic (45 MeV) electron bunches from a linear
+accelerator. The self-generated magnetic fields are found to self-organize into
+a quasi-static structure consistent with a helicoid topology within a few ps
+and such a structure lasts for tens of ps in underdense plasmas. The measured
+growth rate agrees well with that predicted by the kinetic theory of plasmas
+taking into account collisions. Magnetic trapping is identified as the dominant
+saturation mechanism.",2011.09979v1
+2022-06-03,Development of Ni doped SnO$_2$ Dilute magnetic oxides for electronics and spintronics applications,"We used a solid-state reaction method to prepare Sn$_{1-x}$Ni$_x$O$_2$ with
+$x$ = 0, 0.05, 0.1, 0.15 polycrystalline compounds. A rutile phase with
+tetragonal crystal structure was confirmed by X-ray diffraction. At room
+temperature, the magnetisation study shows that the saturation magnetization
+increases with Ni doping content whereas the coercive field decreases after
+$x$=0.1. The spin number increases as the Ni doping concentration increases,
+indicating that the incorporation of Ni into the Sn sites increases the number
+of spins interacting to improve the ferromagnetic phase , which is like
+saturation magnetization and coercive field.",2206.01525v1
+2022-12-26,Optimal design of nanomagnets for on-chip field gradients,"The generation of localized magnetic field gradients by on-chip nanomagnets
+is important for a variety of technological applications, in particular for
+spin qubits. To advance beyond the empirical design of these nanomagnets, we
+propose a systematic and general approach based on the micromagnetic
+formulation of an optimal field gradient source. We study the different field
+configurations that can be realized and find out quantitatively the most
+suitable ferromagnetic layer geometries. Using micromagnetic simulations, we
+then investigate the minimum requirements for reaching magnetic saturation in
+these nanomagnets. In terms of either longitudinal or transverse field
+gradient, the results provide an optimal solution for uniform, saturated
+nanomagnets, where the magnetic material can be selected according to the
+strength of the external fields that can be used.",2212.13156v1
+2023-05-04,Small-scale dynamos: From idealized models to solar and stellar applications,"In this article we review small-scale dynamo processes that are responsible
+for magnetic field generation on scales comparable to and smaller than the
+energy carrying scales of turbulence. We provide a review of critical
+observation of quiet Sun magnetism, which have provided strong support for the
+operation of a small-scale dynamo in the solar photosphere and convection zone.
+After a review of basic concepts we focus on numerical studies of kinematic
+growth and non-linear saturation in idealized setups, with special emphasis on
+the role of the magnetic Prandtl number for dynamo onset and saturation. Moving
+towards astrophysical applications we review convective dynamo setups that
+focus on the deep convection zone and the photospheres of solar-like stars. We
+review the critical ingredients for stellar convection setups and discuss their
+application to the Sun and solar-like stars including comparison against
+available observations.",2305.02787v1
+2015-05-18,Simulating Astrophysical Magnetic Fields with Smoothed Particle Magnetohydrodynamics,"Numerical methods to improve the treatment of magnetic fields in smoothed
+field magnetohydrodynamics (SPMHD) are developed and tested. Chapter 2 is a
+review of SPMHD. In Chapter 3, a mixed hyperbolic/parabolic scheme is developed
+which cleans divergence error from the magnetic field. Average divergence error
+is an order of magnitude lower for all test cases considered, and allows for
+the stable simulation of the gravitational collapse of magnetised molecular
+cloud cores. The effectiveness of the cleaning may be improved by explicitly
+increasing the hyperbolic wave speed or by cycling the cleaning equations
+between timesteps. In the latter, it is possible to achieve DivB=0. Chapter 4
+develops a switch to reduce dissipation of the magnetic field from artificial
+resistivity. Compared to the existing switch in the literature, this leads to
+sharper shock profiles in shocktube tests, lower overall dissipation of
+magnetic energy, and importantly, is able to capture magnetic shocks in the
+highly super-Alfvenic regime. Chapter 5 compares these numerical methods
+against grid-based MHD methods (using the Flash code) in simulations of the
+small-scale dynamo amplification of a magnetic field in driven, isothermal,
+supersonic turbulence. Both codes exponentially amplify the magnetic energy at
+a constant rate, though SPMHD shows a resolution dependence that arises from
+the scaling of the numerical dissipation terms. The time-averaged saturated
+magnetic spectra have similar shape, and both codes have PDFs of magnetic field
+strength that are log-normal, which become lopsided as the magnetic field
+saturates. We conclude that SPMHD is able to reliably simulate the small-scale
+dynamo amplification of magnetic fields. Chapter 6 concludes the thesis and
+presents some preliminary work demonstrating that SPMHD can activate the
+magneto-rotational instability in 2D shearing box tests.",1505.04494v1
+2018-06-28,"Fluctuation Dynamo in a Collisionless, Weakly Magnetized Plasma","Results from a numerical study of fluctuation dynamo in a collisionless,
+weakly magnetized plasma are presented. The key difference between this dynamo
+and its magnetohydrodynamic (MHD) counterpart is the adiabatic production of
+magnetic-field-aligned pressure anisotropy by the amplification of a weak seed
+field. This in turn drives kinetic instabilities on the ion-Larmor
+scale---namely, firehose and mirror---which sever the adiabatic link between
+the thermal and magnetic pressures, thereby allowing the dynamo to proceed.
+After an initial phase of rapid growth driven by these instabilities, the
+magnetic energy grows exponentially and exhibits a $k^{3/2}$ spectrum that
+peaks near the resistive scale, similar to the large-magnetic-Prandtl-number
+($\mathrm{Pm}\gg{1}$) MHD dynamo. The magnetic field self-organizes into a
+folded-sheet topology, with direction reversals at the resistive scale and
+field lines curved at the parallel scale of the flow. The effective
+$\mathrm{Pm}$ is determined by whether the ion-Larmor scale is above or below
+the field-reversing scale: in the former case, particles undergo Bohm-like
+diffusion; in the latter case, particles scatter primarily off firehose
+fluctuations residing at the ends of the magnetic folds, and the viscosity
+becomes anisotropic. The magnetic field ultimately saturates at dynamical
+strengths, with its spectral peak migrating towards larger scales. This
+feature, along with an anti-correlation of magnetic-field strength and
+field-line curvature and a gradual thinning of magnetic sheets into ribbons,
+resemble the saturated state of the large-$\mathrm{Pm}$ dynamo, the primary
+differences manifesting in firehose/mirror-unstable regions. These results have
+implications for magnetic-field growth in the weakly collisional intracluster
+medium of galaxy clusters.",1806.11162v3
+2023-10-03,The effect of surface oxidation and crystal thickness on magnetic properties and magnetic domain structures of Cr2Ge2Te6,"Van der Waals (vdW) magnetic materials such as Cr2Ge2Te6 (CGT) show promise
+for novel memory and logic applications. This is due to their broadly tunable
+magnetic properties and the presence of topological magnetic features such as
+skyrmionic bubbles. A systematic study of thickness and oxidation effects on
+magnetic domain structures is important for designing devices and vdW
+heterostructures for practical applications. Here, we investigate thickness
+effects on magnetic properties, magnetic domains, and bubbles in
+oxidation-controlled CGT crystals. We find that CGT exposed to ambient
+conditions for 5 days forms an oxide layer approximately 5 nm thick. This
+oxidation leads to a significant increase in the oxidation state of the Cr
+ions, indicating a change in local magnetic properties. This is supported by
+real space magnetic texture imaging through Lorentz transmission electron
+microscopy. By comparing the thickness dependent saturation field of oxidized
+and pristine crystals, we find that oxidation leads to a non-magnetic surface
+layer which is thicker than the oxide layer alone. We also find that the stripe
+domain width and skyrmionic bubble size are strongly affected by the crystal
+thickness in pristine crystals. These findings underscore the impact of
+thickness and surface oxidation on the properties of CGT such as saturation
+field and domain/skyrmionic bubble size and suggest a pathway for manipulating
+magnetic properties through a controlled oxidation process.",2310.02319v2
+2001-08-05,Low Energy Behaviour of XXZ Antiferromagnetic Spin Chain,"Zero temperature phase diagram of XXZ spin chain in external magnetic field
+is investigated at low energies using path integral approach.It has been shown
+by spin wave analysis and then by nonlinear sigma model transformation that
+below some critical field the system undergoes quantum Kosterlitz-Thouless
+phase transition.Above that critical field for low anisotropies the system is
+saturated while at strong anisotropy the system has Ising antiferromagnetic
+order.",0108086v1
+2007-09-03,On the magnetic fields generated by experimental dynamos,"We review the results obtained by three successful fluid dynamo experiments
+and discuss what has been learnt from them about the effect of turbulence on
+the dynamo threshold and saturation. We then discuss several questions that are
+still open and propose experiments that could be performed to answer some of
+them.",0709.0234v1
+2016-09-26,Energy-based Modeling of AC Motors,"We propose an approach to modeling of AC motors entirely based on analytical
+mechanics. Symmetry and connection constraints are moreover incorporated in the
+energy function from which the models are derived. The approach is especially
+suited to handle magnetic saturation, but also directly recovers the standard
+unsaturated models of the literature. The theory is illustrated by some
+experimental data.",1609.08050v1
+2017-04-25,Characterization of Zinc oxide & Aluminum Ferrite and Simulation studies of M-H plots of Cobalt/Cobaltoxide,"Zinc oxide and Aluminum Ferrite were prepared Chemical route. The samples
+were characterized by XRD and VSM. Simulation of M-H plots of Co/CoO thin films
+were performed. Effect of parameters was observed on saturation magnetization.",1705.00525v2
+2020-02-04,Amplitude of vortical turbulence in crossed fields in mass-separator at optimum parameters,"Properties and excitation of the vortical turbulence, excited in a
+cylindrical radially inhomogeneous plasma in crossed radial electric and
+longitudinal magnetic fields, are considered. The expression for the vortex
+amplitude of saturation has been derived.",2002.01280v1
+2006-01-11,"Turbulence, magnetic fields and plasma physics in clusters of galaxies","Observations of galaxy clusters show that the intracluster medium (ICM) is
+likely to be turbulent and is certainly magnetized. The properties of this
+magnetized turbulence are determined both by fundamental nonlinear
+magnetohydrodynamic interactions and by the plasma physics of the ICM, which
+has very low collisionality. Cluster plasma threaded by weak magnetic fields is
+subject to firehose and mirror instabilities. These saturate and produce
+fluctuations at the ion gyroscale, which can scatter particles, increasing the
+effective collision rate and, therefore, the effective Reynolds number of the
+ICM. A simple way to model this effect is proposed. The model yields a
+self-accelerating fluctuation dynamo whereby the field grows explosively fast,
+reaching the observed, dynamically important, field strength in a fraction of
+the cluster lifetime independent of the exact strength of the seed field. It is
+suggested that the saturated state of the cluster turbulence is a combination
+of the conventional isotropic magnetohydrodynamic turbulence, characterized by
+folded, direction-reversing magnetic fields and an Alfv\'en-wave cascade at
+collisionless scales. An argument is proposed to constrain the reversal scale
+of the folded field. The picture that emerges appears to be in qualitative
+agreement with observations of magnetic fields in clusters.",0601246v2
+2009-03-09,Interacting Superparamagnetism in La0.7Sr0.3MnO3 Nanoparticles,"The magnetic order of La0.7Sr0.3MnO3 nanoparticles (NPs) fabricated in a SPEX
+D8000 mill was systematically studied. The La0.7Sr0.3MnO3 nanocrystals grow
+from the milled constituent oxides during the milling processes. The
+magnetization data obtained by using a SQUID magnetometer show the NPs as a
+superparamagnet in terms of anhysteretic curves near room temperature.
+Unoverlaping of the scaled M(H-ext, T)/M-s vs. H-ext, T plots and the dc
+susceptibility obeying the Curie-Weiss behavior rather than the Curie law at
+high temperatures provide evidence that the NPs are interacting
+superparamagnetic ensembles. A mean-field correction to the Langevin function L
+([H-ext + alpha M]/k(B)T) worked well for the magnetic ordering of the NPs. By
+means of the Langevin fitting, the diameter of the NP was estimated to be lower
+than 15 nm, depending oil the milling time. The saturation magnetization of NPs
+varied from 48.5 em/g to 19 emu/g, with the higher value corresponding to a
+larger particle size. A core-shell structure of the NP was adopted, with the NP
+having the core-shell magnetically-effective mass density. This is applicable
+to the variation of the saturation magnetization with particle size.",0903.1565v1
+2009-05-03,Simulation study of the filamentation of counter-streaming beams of the electrons and positrons in plasmas,"The filamentation instability driven by two spatially uniform and
+counter-streaming beams of charged particles in plasmas is modelled by a
+particle-in-cell (PIC) simulation. Each beam consists of the electrons and
+positrons. The four species are equally dense and they have the same
+temperature. The one-dimensional simulation direction is orthogonal to the beam
+velocity vector. The magnetic field grows spontaneously and rearranges the
+particles in space, such that the distributions of the electrons of one beam
+and the positrons of the second beam match. The simulation demonstrates that as
+a result no electrostatic field is generated by the magnetic field through its
+magnetic pressure gradient prior to its saturation. This electrostatic field
+would be repulsive at the centres of the filaments and limit the maximum charge
+and current density. The filaments of electrons and positrons in this
+simulation reach higher charge and current densities than in one with no
+positrons. The oscillations of the magnetic field strength induced by the
+magnetically trapped particles result in an oscillatory magnetic pressure
+gradient force. The latter interplays with the statistical fluctuations in the
+particle density and it probably enforces a charge separation, by which
+electrostatic waves grow after the filamentation instability has saturated.",0905.0276v1
+2010-08-30,"Intriguing complex magnetism of Co in RECoAsO (RE=La, Nd and Sm)","We synthesized bulk polycrystalline samples of RECoAsO (RE=La, Nd and Sm) by
+solid state reaction route in an evacuated sealed quartz tube. All these
+compounds are crystallized in a tetragonal structure with space group P4/nmm.
+The Co, in these compounds is in itinerant ferromagnetic state with its
+paramagnetic moment above 1.5 microB and the same orders ferromagnetically (FM)
+with small saturation moment of around 0.20 microB below say 80K. This bulk
+intrinsic magnetism of Co changes dramatically when nonmagnetic La is changed
+by magnetic Sm and Nd. Although the itinerant ferromagnetism occurs below
+80-100K with small saturation moment, typical anti-ferromagnetic (AFM)
+transitions (TN1, TN2) are observed at 57K and 45K for Sm and at 69K and 14K
+for Nd. The transition of Co spins from FM to AFM, for magnetic Sm and Nd in
+RECoAsO is both field and temperature dependent. For applied fields below
+100Oe, both TN1 and TN2 are seen, with intermediate fields below 1-2kOe only
+TN1 and above say 5kOe the AFM transition is not observed. This is evidenced in
+isothermal magnetization (MH) plots as well. It is clear that Sm/Nd magnetic
+moments interact with the ordered Co spins in adjacent layer and thus
+transforms the FM ordering to AFM. All the studied compounds are metallic in
+nature, and their magneto-transport R(T)H follows the temperature and field
+dependent FM-AFM transition of ordered Co spins.",1008.4999v3
+2010-12-17,"Radially Extended, Stratified, Local Models of Isothermal Disks","We consider local, stratified, numerical models of isothermal accretion
+disks. The novel feature of our treatment is that radial extent L_x and
+azimuthal extent L_y satisfy H << L_x, L_y << R, where H is the scale height
+and R is the local radius. This enables us to probe mesoscale structure in
+stratified thin disks. We evolve the model at several resolutions, sizes, and
+initial magnetic field strengths. Consistent with earlier work, we find that
+the saturated, turbulent state consists of a weakly magnetized disk midplane
+coupled to a strongly magnetized corona, with a transition at |z| ~ 2H. The
+saturated \alpha ~ 0.01 - 0.02. A two-point correlation function analysis
+reveals that the central 4H of the disk is dominated by small scale turbulence
+that is statistically similar to unstratified disk models, while the coronal
+magnetic fields are correlated on scales ~ 10 H. Nevertheless angular momentum
+transport through the corona is small. A study of magnetic field loops in the
+corona reveals few open field lines and predominantly toroidal loops with a
+characteristic distance between footpoints that is ~ H. Finally we find
+quasi-periodic oscillations with characteristic timescale ~ 30 \Omega^{-1} in
+the magnetic field energy density. These oscillations are correlated with
+oscillations in the mean azimuthal field; we present a phenomenological,
+alpha-dynamo model that captures most aspects of the oscillations.",1012.3789v1
+2011-03-25,Numerical simulation of laminar plasma dynamos in a cylindrical von Kármán flow,"The results of a numerical study of the magnetic dynamo effect in cylindrical
+von K\'arm\'an plasma flow are presented with parameters relevant to the
+Madison Plasma Couette Experiment. This experiment is designed to investigate a
+broad class of phenomena in flowing plasmas. In a plasma, the magnetic Prandtl
+number Pm can be of order unity (i.e., the fluid Reynolds number Re is
+comparable to the magnetic Reynolds number Rm). This is in contrast to liquid
+metal experiments, where Pm is small (so, Re>>Rm) and the flows are always
+turbulent. We explore dynamo action through simulations using the extended
+magnetohydrodynamic NIMROD code for an isothermal and compressible plasma
+model.We also study two-fluid effects in simulations by including the Hall term
+in Ohm's law. We find that the counter-rotating von K\'arm\'an flow results in
+sustained dynamo action and the self-generation of magnetic field when the
+magnetic Reynolds number exceeds a critical value. For the plasma parameters of
+the experiment, this field saturates at an amplitude corresponding to a new
+stable equilibrium (a laminar dynamo). We show that compressibility in the
+plasma results in an increase of the critical magnetic Reynolds number, while
+inclusion of the Hall term in Ohm's law changes the amplitude of the saturated
+dynamo field but not the critical value for the onset of dynamo action.",1103.5041v1
+2011-10-03,Small-scale dynamo action in rotating compressible convection,"We study dynamo action in a convective layer of electrically-conducting,
+compressible fluid, rotating about the vertical axis. At the upper and lower
+bounding surfaces, perfectly-conducting boundary conditions are adopted for the
+magnetic field. Two different levels of thermal stratification are considered.
+If the magnetic diffusivity is sufficiently small, the convection acts as a
+small-scale dynamo. Using a definition for the magnetic Reynolds number $R_M$
+that is based upon the horizontal integral scale and the horizontally-averaged
+velocity at the mid-layer of the domain, we find that rotation tends to reduce
+the critical value of $R_M$ above which dynamo action is observed. Increasing
+the level of thermal stratification within the layer does not significantly
+alter the critical value of $R_M$ in the rotating calculations, but it does
+lead to a reduction in this critical value in the non-rotating cases. At the
+highest computationally-accessible values of the magnetic Reynolds number, the
+saturation levels of the dynamo are similar in all cases, with the mean
+magnetic energy density somewhere between 4 and 9% of the mean kinetic energy
+density. To gain further insights into the differences between rotating and
+non-rotating convection, we quantify the stretching properties of each flow by
+measuring Lyapunov exponents. Away from the boundaries, the rate of stretching
+due to the flow is much less dependent upon depth in the rotating cases than it
+is in the corresponding non-rotating calculations. It is also shown that the
+effects of rotation significantly reduce the magnetic energy dissipation in the
+lower part of the layer. We also investigate certain aspects of the saturation
+mechanism of the dynamo.",1110.0374v1
+2012-01-12,Local Simulations of Instabilities in Relativistic Jets I: Morphology and Energetics of the Current-Driven Instability,"We present the results of a numerical investigation of current-driven
+instability in magnetized jets. Utilizing the well-tested, relativistic
+magnetohydrodynamic code Athena, we construct an ensemble of local, co-moving
+plasma columns in which initial radial force balance is achieved through
+various combinations of magnetic, pressure, and rotational forces. We then
+examine the resulting flow morphologies and energetics to determine the degree
+to which these systems become disrupted, the amount of kinetic energy
+amplification attained, and the non-linear saturation behaviors. Our most
+significant finding is that the details of initial force balance have a
+pronounced effect on the resulting flow morphology. Models in which the initial
+magnetic field is force-free deform, but do not become disrupted. Systems that
+achieve initial equilibrium by balancing pressure gradients and/or rotation
+against magnetic forces, however, tend to shred, mix, and develop turbulence.
+In all cases, the linear growth of current-driven instabilities is
+well-represented by analytic models. CDI-driven kinetic energy amplification is
+slower and saturates at a lower value in force-free models than in those that
+feature pressure gradients and/or rotation. In rotating columns, we find that
+magnetized regions undergoing rotational shear are driven toward equipartition
+between kinetic and magnetic energies. We show that these results are
+applicable for a large variety of physical parameters, but we caution that
+algorithmic decisions (such as choice of Riemann solver) can affect the
+evolution of these systems more than physically motivated parameters.",1201.2681v2
+2012-04-03,The Small-Scale Dynamo and Non-Ideal MHD in Primordial Star Formation,"We study the amplification of magnetic fields during the formation of
+primordial halos. The turbulence generated by gravitational infall motions
+during the formation of the first stars and galaxies can amplify magnetic
+fields very efficiently and on short timescales up to dynamically significant
+values. Using the Kazantsev theory, which describes the so-called small-scale
+dynamo - a magnetohydrodynamical process converting kinetic energy from
+turbulence into magnetic energy - we can then calculate the growth rate of the
+small-scale magnetic field. Our calculations are based on a detailed chemical
+network and we include non-ideal magnetohydrodynamical effects such as
+ambipolar diffusion and Ohmic dissipation. We follow the evolution of the
+magnetic field up to larger scales until saturation occurs on the Jeans scale.
+Assuming a weak magnetic seed field generated by the Biermann battery process,
+both Burgers and Kolmogorov turbulence lead to saturation within a rather small
+density range. Such fields are likely to become relevant after the formation of
+a protostellar disk and, thus, could influence the formation of the first stars
+and galaxies in the Universe.",1204.0658v2
+2014-01-31,PIC Simulations of Continuously Driven Mirror and Ion Cyclotron Instabilities in High Beta Astrophysical and Heliospheric Plasmas,"We use particle-in-cell (PIC) simulations to study the nonlinear evolution of
+ion velocity space instabilities in an idealized problem in which a background
+velocity shear continuously amplifies the magnetic field. We simulate the
+astrophysically relevant regime where the shear timescale is long compared to
+the ion cyclotron period, and the plasma beta is ~ 1-100. The background field
+amplification in our calculation is meant to mimic processes such as turbulent
+fluctuations or MHD-scale instabilities. The field amplification continuously
+drives a pressure anisotropy with the perpendicular pressure larger than the
+parallel pressure, and the plasma becomes unstable to the mirror and ion
+cyclotron instabilities. In all cases, the nonlinear state is dominated by the
+mirror instability, not the ion cyclotron instability, and the plasma pressure
+anisotropy saturates near the threshold for the linear mirror instability. The
+magnetic field fluctuations initially undergo exponential growth but saturate
+in a secular phase in which the fluctuations grow on the same timescale as the
+background magnetic field (with \delta B ~ 0.3 <B> in the secular phase). At
+early times, the ion magnetic moment is well-conserved but once the fluctuation
+amplitudes exceed \delta B ~ 0.1 <B>, the magnetic moment is no longer
+conserved but instead changes on a timescale comparable to that of the mean
+magnetic field. We discuss the implications of our results for
+low-collisionality astrophysical plasmas, including the near-Earth solar wind
+and low-luminosity accretion disks around black holes.",1402.0014v2
+2017-04-20,Spectral Scaling Technique to Determine Extreme Carrington-level Geomagnetically Induced Currents Effects,"Space weather events produce variations in the electric current in the
+Earth's magnetosphere and ionosphere. From these high altitude atmospheric
+regions, resulting geomagnetically induced currents (GICs) can lead to
+fluctuations in ground currents that affect the electric power grid and
+potentially overload transformers during extreme storms. The most extreme
+geomagnetic storm on record, known as the 1859 Carrington event, was so intense
+that ground-based magnetometers were saturated at high magnetic latitudes. The
+most reliable, un-saturated observation is the hour-resolution data from the
+Colaba Magnetic Observatory in India. However, higher frequency components --
+fluctuations at second through minute time cadence -- to the magnetic field can
+play a significant role in GIC-related effects. We present a new method for
+scaling higher frequency observations to create a realistic Carrington-like
+event magnetic field model, using modern magnetometer observations. Using the
+magnetic field model and ground conductivity models, we produce an electric
+field model. This method can be applied to create similar magnetic and electric
+field models for studies of GIC effects on power-grids.",1705.05325v1
+2019-01-07,Field-induced phases in a heavy-fermion U(Ru$_{0.92}$Rh$_{0.08}$)$_{2}$Si$_{2}$ single crystal,"We report the high-field induced magnetic phases and phase diagram of a high
+quality \urxrs~single crystal prepared using a modified Czochralski method. Our
+study, that combines high-field magnetization and electrical resistivity
+measurements, shows for fields applied along the $c$-axis direction three
+field-induced magnetic phase transitions at $\mu_{0} H_{c1}$ = 21.60 T,
+$\mu_{0} H_{c2}$ = 37.90 T and $\mu_{0} H_{c3}$ = 38.25 T, respectively. In
+agreement with a microscopic up-up-down arrangement of the U magnetic moments
+the phase above $H_{c1}$ has a magnetization of about one third of the
+saturated value. In contrast the phase between $H_{c2}$ and $H_{c3}$ has a
+magnetization that is a factor of two lower than above the $H_{c3}$, where a
+polarized Fermi-liquid state with a saturated moment $M_{s}$ $\approx$ 2.1
+$\mu_{B}$/U is realized. Most of the respective transitions are reflected in
+the electrical resistivity as sudden drastic changes. Most notably, the phase
+between $H_{c1}$ and $H_{c2}$ exhibits substantially larger values. As the
+temperature increases, transitions smear out and disappear above $\approx$ 15
+K. However, a substantial magnetoresistance is observed even at temperatures as
+high as 80 K. Due to a strong uniaxial magnetocrystalline anisotropy a very
+small field effect is observed for fields apllied perpendicular to the $c$-axis
+direction.",1901.01750v1
+2019-06-13,Electrodynamic improvements to the theory of magnetostatic modes in ferrimagnetic spheres and their applications to saturation magnetization measurements,"Electrodynamic theory applied to the analysis of TEn0p mode resonances in
+ferromagnetic spheres placed either in metallic cavities or in the free space
+is compared with Walker-Fletcher's theory of so-called magnetostatic modes. The
+influence of the diameter of the sample, its permittivity and the permittivity
+of the surrounding media on the resonance frequencies of a few modes is
+analyzed. It is shown that the dominant resonances are essentially related
+either to negative values of the diagonal component of the permeability tensor
+or, for clockwise circularly polarized magnetic fields, to negative effective
+permeability. The electrodynamic theory is used to determine the saturation
+magnetization (Ms) from measured TEn01 frequency differences. Measurements on
+different samples confirmed that Ms can be determined using an electrodynamic
+approach with uncertainties of the order of 2% regardless of sample sizes,
+metal enclosures or static magnetic field values.",1906.05559v1
+2020-02-10,On the anisotropies of magnetization and electronic transport of magnetic Weyl semimetal Co3Sn2S2,"Co3Sn2S2, a quasi-two-dimensional system with kagome lattice, has been found
+as a magnetic Weyl semimetal recently. In this work, the anisotropies of
+magnetization and transport properties of Co3Sn2S2 were investigated. The high
+field measurements reveal a giant magnetocrystalline anisotropy with an
+out-of-plane saturation field of 0.9 kOe and an in-plane saturation field of
+230 kOe at 2 K, showing a magnetocrystalline anisotropy coefficient Ku up to
+8.3 * 10^5 J m-3, which indicates that it is extremely difficult to align the
+small moment of 0.29 {\mu}B/Co on the kagome lattice from c axis to ab plane.
+The out-of-plane angular dependences of Hall conductivity further reveal strong
+anisotropies in Berry curvature and ferromagnetism, and the vector directions
+of both are always parallel with each other. For in-plane situation, the
+longitudinal and transverse measurements for both I parallel a and I
+perpendicular a cases show that the transport on the kagome lattice is
+isotropic. These results provide essential understanding on the magnetization
+and transport behaviors for the magnetic Weyl semimetal Co3Sn2S2.",2002.03940v1
+2020-08-29,Characteristics of Pumping Current in a YBCO Coil by a Pulse-Type Magnetic Flux Pump,"2G high temperature superconducting (HTS) wires, YBCO coated conductors,
+perform a better carrying current capability, which is potentially applied in
+the manufacture of HTS magnets. This paper presents the experimental results of
+the pumping current for YBCO coils using a pulse-type magnetic flux pump in the
+conduction-cooling system and liquid nitrogen bath (LN2) cryogenic environment.
+Optimization of the flux pump used in the conduction-cooling system is that a
+constantan heater was added to keep the temperature of the pumping bridge at a
+certain value. Excitation effects of the YBCO coil at different temperatures
+were investigated in the conduction-cooling system. A fast-increasing of
+pumping current in the YBCO coil occurs when the temperature of the YBCO sheet
+(i.e., pumping bridge) is in the range of 50 K to 80 K. The relationships
+between saturated pumping current and input voltage, working frequency, numbers
+of magnetic poles were also studied. Using the seven-pole configuration, the
+saturated current can reach 155 A when the frequency is 20 Hz and the voltage
+is 6 V. The excitation characteristics of the flux pump in the LN2 cooling
+system show the possibility of the pulse-type magnetic flux pump for the
+practical application of HTS magnets.",2008.12941v2
+2020-09-21,Influence of ambipolar and Hall effects on vorticity in 3D simulations of magneto-convection,"This paper presents the results of the analysis of 3D simulations of solar
+magneto-convection that include the joint action of the ambipolar diffusion and
+the Hall effect. Three simulation-runs are compared: one including both
+ambipolar diffusion and Hall effect; one including only ambipolar diffusion;
+and one without any of these two effects. The magnetic field is amplified from
+initial field to saturation level by the action of turbulent local dynamo. In
+each of these cases, we study 2 hours of simulated solar time after the local
+dynamo reaches the saturation regime. We analyze the power spectra of
+vorticity, of magnetic field fluctuations and of the different components of
+the magnetic Poynting flux responsible for the transport of vertical or
+horizontal perturbations. Our preliminary results show that the ambipolar
+diffusion produces a strong reduction of vorticity in the upper chromospheric
+layers and that it dissipates the vortical perturbations converting them into
+thermal energy. The Hall effect acts in the opposite way, strongly enhancing
+the vorticity. When the Hall effect is included, the magnetic field in the
+simulations becomes, on average, more vertical and long-lived flux tube-like
+structures are produced. We trace a single magnetic structure to study its
+evolution pattern and the magnetic field intensification, and their possible
+relation to the Hall effect.",2009.09753v1
+2020-11-10,Saturation of Energy Levels of the Hydrogen Atom in Strong Magnetic Field,"We demonstrate that the finiteness of the limiting values of the lower energy
+levels of a hydrogen atom under an unrestricted growth of the magnetic field,
+into which this atom is embedded, is achieved already when the vacuum
+polarization (VP) is calculated in the magnetic field within the approximation
+of the local action of Euler--Heisenberg. We find that the mechanism for this
+saturation is different from the one acting, when VP is calculated via the
+Feynman diagram in the Furry picture. We study the effective potential that
+appears when the adiabatic (diagonal) approximation is exploited for solving
+the Schr\""{o}dinger equation for the longitudinal degree of freedom of the
+electron on the lowest Landau level in the atom. We find that the (effective)
+potential of a point-like charge remains nonsingular thanks to the growing
+screening provided by VP. The regularizing length turns out to be $\sqrt{\alpha
+/3\pi }\lambdabar_{\mathrm{C}}$, where $\lambdabar_{\mathrm{C}}$ is the
+electron Compton length. The family of effective potentials, labeled by growing
+values of the magnetic field condenses towards a certain limiting,
+magnetic-field-independent potential-distance curve. The~limiting values of
+even ground-state energies are determined for four magnetic quantum numbers
+using the Karnakov--Popov method.",2011.12422v1
+2021-07-24,Anomalous Nernst thermopower and giant magnetostriction in microwave synthesized La0.5Sr0.5CoO3,"Ferromagnetic metallic oxides have potential applications in spincaloric
+devices which utilize the spin property of charge carriers for interconversion
+of heat and electricity through the spin Seebeck or the anomalous Nernst effect
+or both. In this work, we synthesized polycrystalline La0.5S0.5CoO3 by
+microwave irradiation method and studied its transverse thermoelectric voltage
+(Nernst thermopower) and change in the linear dimension of the sample (Joule
+magnetostriction) in response to external magnetic fields. In addition,
+magnetization, temperature dependences of electrical resistivity, and
+longitudinal Seebeck coefficient (Sxx) in absence of an external magnetic field
+were also measured. The sample is ferromagnetic with a Curie temperature of TC
+= 247 K and shows a metal-like resistivity above and below TC with a negative
+sign of Sxx suggesting charge transport due to electrons. Magnetic field
+dependence of the Nernst thermopower (Sxy) at a fixed temperature shows a rapid
+increase at low fields and a tendency to saturate at high fields as like the
+magnetization. Anomalous contribution to Sxy was extracted from total Sxy
+measured and it exhibits a maximum value of ~ 0.21 microV/K at 180 K for H = 50
+kOe, which is comparable to the value found in a single crystal for a lower Sr
+content. The Joule magnetostriction is positive, i.e., the length of the sample
+expands along the direction of the magnetic field and it does not saturate even
+at 50 kOe. The magnetostriction increases with decreasing temperature below TC
+and reaches a maximum value of 500 ppm at T = 40 K and below. Coexistence of
+the anomalous Nernst thermopower and giant magnetostriction in a single
+compound has potential applications for thermal energy harvesting and
+low-temperature actuators, respectively.",2107.11535v1
+2022-10-10,The small-scale dynamo in a multiphase supernova-driven medium,"Magnetic fields grow quickly, even at early cosmological times, suggesting
+the action of a small-scale dynamo (SSD) in the interstellar medium (ISM) of
+galaxies. Many studies have focused on idealized, isotropic, homogeneous,
+turbulent driving of the SSD. Here we analyze more realistic simulations of
+supernova-driven turbulence to understand how it drives an SSD. We find that
+SSD growth rates are intermittently variable as a result of the evolving
+multiphase ISM structure. Rapid growth in the magnetic field typically occurs
+in hot gas, with the highest overall growth rates occurring when the fractional
+volume of hot gas is large. SSD growth rates correlate most strongly with
+vorticity and fluid Reynolds number, which also both correlate strongly with
+gas temperature. Rotational energy exceeds irrotational energy in all phases,
+but particularly in the hot phase while SSD growth is most rapid. Supernova
+(SN) rate does not significantly affect the ISM average kinetic energy density.
+Rather, higher temperatures associated with high SN rates tend to increase SSD
+growth rates. SSD saturates with total magnetic energy density around 5% of
+equipartition to kinetic energy density, increasing slightly with magnetic
+Prandtl number. While magnetic energy density in the hot gas can exceed that of
+the other phases when SSD grows most rapidly, it saturates below 5% of
+equipartition with kinetic energy in the hot gas, while in the cold gas it
+attains 100%. Fast, intermittent growth of the magnetic field appears to be a
+characteristic behavior of SN-driven, multiphase turbulence.",2210.04460v2
+2023-02-25,Effect of time-varying electromagnetic field on Wiedemann-Franz law in a hot hadronic matter,"We have estimated the electrical and thermal conductivity of a hadron
+resonance gas for a time-varying magnetic field, which is also compared with
+constant and zero magnetic field cases. Considering the exponential decay of
+electromagnetic fields with time, a kinetic theory framework can provide the
+microscopic expression of electrical and thermal conductivity in terms of
+relaxation and decay times. In the absence of the magnetic field, only a single
+time scale appears, and in the finite magnetic field case, their expressions
+carry two-time scales, relaxation time and cyclotron time period. Estimating
+the conductivities for HRG matter in three cases -- zero, constant, and
+time-varying magnetic fields, we have studied the validity of the
+Wiedemann-Franz law. We noticed that at a high-temperature domain, the ratio
+saturates at a particular value, which may be considered as Lorenz number of
+the hadron resonance gas. With respect to the saturation values, the deviation
+of the Wiedemann-Franz law has been quantified at the low-temperature domain.
+For the first time, the present work sketches this quantitative deviation of
+the Wiedemann-Franz law for hadron resonance gas at a constant and a
+time-varying magnetic field.",2302.13042v2
+2023-04-24,Magnetic plateaus and jumps in a spin-1/2 ladder with alternate Ising-Heisenberg rungs: a field dependent study,"We study a frustrated two-leg spin-1/2 ladder with alternate Ising and
+isotropic Heisenberg rung exchange interactions, whereas, interactions along
+legs and diagonals are Ising type. The ground-state (GS) of this model has four
+exotic phases: (i) the stripe-rung ferromagnet (SRFM), (ii) the anisotropic
+anti-ferromagnet (AAFM), (iii) the Dimer, and (iv) the stripe-leg ferromagnet
+(SLFM) in absence of any external magnetic field. In this work, the effect of
+externally applied longitudinal and transverse fields on quantum phases are
+studied. In both cases, we show that there exist two plateau phases at $1/4$,
+and $1/2$ of the saturation of magnetization. Due to the strong rung dimer
+formation, the system opens a finite spin gap for all the phases resulting in
+zero magnetization plateau in presence of a longitudinal field. The mechanism
+of plateau formation is analyzed using spin density, quantum fidelity, and
+quantum concurrence. In the (i) SRFM phase, Ising exchanges are dominant for
+all spins but the Heisenberg rungs are weak, and therefore, the magnetization
+shows a continuous transition as a function of transverse field. In the other
+three phases [(ii)-(iv)], Ising dimer rungs are weak and broken first to reach
+the plateau at $1/2$ of the saturation magnetization, having a large gap, which
+is closed by further application of the field. We use the exact diagonalization
+(ED) and the transfer matrix method (TM) to solve the Hamiltonian.",2304.12266v2
+2023-10-01,Inflows towards Bipolar Magnetic Active Regions and Their Nonlinear Impact on a Three-Dimensional Babcock-Leighton Solar Dynamo Model,"The changing magnetic fields of the Sun are generated and maintained by a
+solar dynamo, the exact nature of which remains an unsolved fundamental problem
+in solar physics. Our objective in this paper is to investigate the role and
+impact of converging flows toward Bipolar Magnetic Regions (BMR inflows) on the
+Sun's global solar dynamo. These flows are large scale physical phenomena that
+have been observed and so should be included in any comprehensive solar dynamo
+model. We have augmented the Surface flux Transport And Babcock LEighton
+(STABLE) dynamo model to study the nonlinear feedback effect of BMR inflows
+with magnitudes varying with surface magnetic fields. This fully 3D realistic
+dynamo model produces the sunspot butterfly diagram and allows a study of the
+relative roles of dynamo saturation mechanisms such as tilt angle quenching and
+BMR inflows. The results of our STABLE simulations show that magnetic field
+dependent BMR inflows significantly affect the evolution of the BMRs themselves
+and result in a reduced buildup of the global poloidal field due to local flux
+cancellation within the BMRs, to an extent that is sufficient to saturate the
+dynamo. As a consequence, for the first time, we have achieved fully 3D solar
+dynamo solutions in which BMR inflows alone regulate the amplitudes and periods
+of the magnetic cycles.",2310.00738v1
+2005-04-29,Saturated-State Turbulence and Structure from Thermal and Magnetorotational Instability in the ISM: Three-Dimensional Numerical Simulations,"This paper reports on 3D numerical simulations of dynamics and thermodynamics
+in the diffuse ISM. Our models are local, account for sheared galactic
+rotation, magnetic fields, and realistic cooling, and resolve scales ~1-200 pc.
+This combination permits the study of quasi-steady turbulence in a cloudy
+medium representing the warm/cold atomic ISM. Turbulence is driven by the
+magnetorotational instability (MRI); our models are the first to study the
+saturated state of MRI under strongly inhomogeneous conditions, with
+cloud/intercloud contrasts of about 100. For volume-averaged densities n=0.25 -
+4 cm^3, the saturated-state velocity dispersion ranges from 8-1 km/s, scaling
+as n^-0.77. The MRI is therefore likely quite important in driving turbulence
+in low-density ISM regions, both at high latitudes in the inner Galaxy,and
+throughout the far outer Galaxy. The MRI may be key to suppressing star
+formation at large radii in spiral galaxies, where without MRI-driven
+turbulence, a thin, cold layer could form and become gravitationally instable.
+Our presentation also includes analysis of thermal structure (temperature and
+density PDFs are broadened and include extreme departures from equilibrium, but
+retain the classical two-phase bimodal character); results on the distribution
+of clump masses (the mass spectrum peaks at about 100 solar masses);
+comparisons of saturated-state MRI scalings with single-phase simulation
+results (we find B^2 is independent of n); and examples of synthetic HI line
+profile maps (showing that physical clumps are not easily distinguished in
+velocity components, and vice versa).",0504669v1
+2016-11-09,Unusual non saturating Giant Magneto-resistance in single crystalline Bi2Te3 topological insulator,"We report synthesis, structural details and electrical transport properties
+of topological insulator Bi2Te3. The single crystalline specimens of Bi2Te3 are
+obtained from high temperature (950C) melt and slow cooling (2C/hour). The
+resultant crystals were shiny, one piece (few cm) and of bright silver color.
+The Bi2Te3 crystal is found to be perfect with clear [00l] alignment. The
+powder XRD pattern being carried out on crushed crystals showed that Bi2Te3
+crystallized in R3m symmetry with a = b = 4.3866(2) A, c = 30.4978(13) A and
+Gamma = 120degree. The Bi position is refined to (0, 0, 0.4038 (9)) at Wyckoff
+position 6c and of Te are (0, 0, 0) at Wyckoff position 3a and at (0, 0,
+0.2039(8)) at 6c. Ambient pressure and low temperature (down to 2K) electrical
+transport measurements revealed metallic behavior. Magneto transport
+measurements under magnetic field showed huge non saturating magneto resistance
+(MR) reaching up to 250% at 2.5K and under 50KOe field. Summarily, the short
+communication clearly demonstrates that Bi2Te3 topological insulator exhibit
+non-saturating large positive MR at low temperature of say below 10K. The non
+saturating MR is seen right up to room temperature albeit with much decreased
+magnitude. Worth mentioning is the fact that these crystals are bulk in nature
+and hence the anomalous MR is clearly an intrinsic property and not due to the
+size effect as reported for nano-wires or thin films of the same.",1611.02859v2
+2018-10-03,Evolution and characteristics of forced shear flows in polytropic atmospheres: Large and small Péclet number regimes,"Complex mixing and magnetic field generation occurs within stellar interiors
+particularly where there is a strong shear flow. To obtain a comprehensive
+understanding of these processes, it is necessary to study the complex dynamics
+of shear regions. Due to current observational limitations, it is necessary to
+investigate the inevitable small-scale dynamics via numerical calculations.
+Here, we examine direct numerical calculations of a local model of unstable
+shear flows in a compressible polytropic fluid primarily in a two-dimensional
+domain, where we focus on determining how key parameters affect the global
+properties and characteristics of the resulting saturated turbulent phase. We
+consider the effect of varying both the viscosity and the thermal diffusivity
+on the non-linear evolution. Moreover, our main focus is to understand the
+global properties of the saturated phase, in particular estimating for the
+first time the spread of the shear region from an initially hyperbolic tangent
+velocity profile. We find that the vertical extent of the mixing region in the
+saturated regime is generally determined by the initial Richardson number of
+the system. Further, the characteristic quantities of the turbulence, i.e.
+typical length-scale and the root-mean-square velocity are found to depend on
+both the Richardson number, and the thermal diffusivity. Finally, we present
+our findings of our investigation into saturated flows of a `secular' shear
+instability in the low P\'eclet number regime with large Richardson numbers.",1810.01706v1
+2021-03-23,Improving the Precision of Optical Metrology by Detecting Fewer Photons,"In optical metrological protocols to measure physical quantities, it is, in
+principle, always beneficial to increase photon number to improve measurement
+precision. However, practical constraints prevent arbitrary increase of n due
+to the imperfections of a practical detector, especially when the detector
+response is dominated by saturation effect. In this work, we show that a
+modified weak measurement protocol, namely, biased weak measurement
+significantly improves the precision of optical metrology in the presence of
+saturation effect. This method detects an ultra-small fraction of photons while
+maintains considerable amount of metrological information. The biased
+pre-coupling leads to an additional reduction of photons in the post-selection
+and generates an extinction point in the spectrum distribution, which is
+extremely sensitive to the estimated parameter and difficult to be saturated.
+Therefore, the Fisher information can be persistently enhanced by increasing
+the photon number. In our magnetic-sensing experiment, biased weak measurement
+achieves precision approximately one order of magnitude better than those of
+previously used methods. The proposed method can be applied in various optical
+measurement schemes to circumvent detector saturation effect with low-cost
+apparatuses.",2103.12373v1
+2022-03-13,"Comment on ""Resonance-induced growth of number entropy in strongly disordered systems""","We comment on the recent paper by Ghosh and \v{Z}nidari\v{c} (Phys. Rev. B
+105, 144203 (2022)) which studies the growth of the number entropy $S_N$ in the
+Heisenberg model with random magnetic fields after a quantum quench. The
+authors present arguments for an intermediate power-law growth in time $t$ and
+a sub-ergodic saturation value, claiming consistency of their results with
+many-body localization (MBL) for strong disorder. We show that these
+interpretations are inconsistent with other recent studies and discuss specific
+issues with the analysis of the numerical data. We point out, in particular,
+that (i) the saturation values $\widetilde{S}_N(L,W)$ for fixed length $L$ are
+only bounded from above by 'the ergodic value' and are already far below this
+value for $W\ll 1$. Furthermore, the saturation values can show non-monotonic
+scaling with $L$. (ii) Power-law fits $S_N(t)\sim 1/t^\alpha$ -- with
+$\alpha=1$ expected based on the resonance model described in the paper --
+yield a system-size dependent exponent $\alpha$ while fits $S_N\sim
+\frac{1}{W^3}\ln\ln t$ do hold independent of system size and over several
+orders of magnitude in time. (iii) We also argue that for the cases where the
+effective resonance model works best and predicts a saturation of the number
+entropy, the same applies to the von-Neumann entropy, i.e.~the dynamics at the
+considered scales is of single particle type and unrelated to MBL.",2203.06689v2
+2007-06-19,Synthesis and magnetic properties of NiFe_{2-x}Al_{x}O_{4} nanoparticles,"Nanocrystalline Al-doped nickel ferrite powders have been synthesized by
+sol-gel auto-ignition method and the effect of non-magnetic aluminum content on
+the structural and magnetic properties has been studied. The X-ray diffraction
+(XRD) revealed that the powders obtained are single phase with inverse spinel
+structure. The calculated grain sizes from XRD data have been verified using
+transmission electron microscopy (TEM). TEM photographs show that the powders
+consist of nanometer-sized grains. It was observed that the characteristic
+grain size decreases from 29 to 6 nm as the non-magnetic Al content increases,
+which was attributed to the influence of non-magnetic Al concentration on the
+grain size. Magnetic hysteresis loops were measured at room temperature with a
+maximum applied magnetic field of 1T. As aluminum content increases, the
+measured magnetic hysteresis curves become more and more narrow and the
+saturation magnetization and remanent magnetization both decreased. The
+reduction of agnetization compared to bulk is a consequence of spin
+non-collinearity. Further reduction of magnetization with increase of aluminum
+content is caused by non-magnetic Al^{3+} ions and weakened interaction between
+sublattices. This, as well as the decrease in hysteresis was understood in
+terms of the decrease in particle size.",0706.2794v1
+2014-05-29,Influence of small scale $E_M$ and $H_M$ on the growth of large scale magnetic field,"We investigated the influence of small scale magnetic energy ($E_M$) and
+magnetic helicity ($H_M$) on the growth rate ($\gamma$) of large scale magnetic
+field ($\overline{{\bf B}}$). $H_M$ that plays a key role in MHD dynamo is a
+topological concept describing the structural properties of magnetic fields.
+So, it is not possible to differentiate the intrinsic properties of $H_M$ from
+the influence of $E_M$, and vice versa. However, to understand MHD dynamo the
+features of helical and nonhelical magnetic field should be made clear. For
+this, we made a detour: we gave each simulation set its own initial condition
+($IC$, same $E_M$(0) and specific $H_M$(0) at $k_f=5$), and then drove the
+system with positive helical kinetic energy($k_f=5$). According to the
+simulation results, $E_M$(0), whether or not helical, increases the growth rate
+of $\overline{{\bf B}}$. The positive $H_M$(0) boosts the increased growth
+rate, but the negative $H_M$(0) decreases it. To explain these results two
+coupled equations of $H_M$ and $E_M$ were derived and solved using a simple
+approximate method. The equations imply that helical magnetic field generates
+the whole (helical and nonhelical) magnetic field but quenches itself.
+Nonhelical magnetic field also generates the whole magnetic field but quenches
+itself. The initially given $E_M$(0) modifies the electromotive force ($\langle
+{\bf v}{\bf \times} {\bf b}\rangle$, $EMF$) and generates new terms. The
+effects of these terms depend on the magnetic diffusivity $\eta$, position of
+initial conditions $k_f$, and time. But the influence disappears as time passes
+($\sim e^{-\eta k_f^2 t}$), so the saturated magnetic fields are independent of
+the initial conditions.",1405.7467v1
+2016-11-29,Calculation of Evaluation Variables for High Gradient Magnetic Separation with an Idealized Capture Model,"This paper regards feed mine as a mixture of intergrowths and pure
+non-magnetic mineral particles, presents a method to calculate the evaluation
+variables such as grade and recovery in high gradient magnetic separation
+(HGMS). A idealized capture model is constructed in which the interaction
+between particles is not taken into account and only for the initial
+aggregation condition that the separator has the highest capture efficiency. In
+the model we adopt the functions that use nominal particle radius and magnetic
+mineral content as independent variables to describe volume fraction
+distribution and capture efficiency of intergrowths respectively. Through
+adding multi-wire magnetic fields and setting periodic boundary conditions in
+flow field analysis, we modify the computational domain of the single-wire
+capture theory to a element domain that periodically appears in the multi-wire
+matrix. By means of finite element software, particle trajectories, flow field
+and magnetic field are clearly exhibited, and then capture efficiency function
+is obtained by interpolation method. The calculated evaluation variables
+theoretically represent the best performance of magnetic separator for a given
+feed. They can assist mineral engineers to evaluate or compare the effects of
+different magnetic separation systems in advance. We use removal of iron
+impurity from kaolin as an example to illustrate the presented calculation
+method. The results quantitatively compare the evaluation variables of the
+separation at different magnetic fields and show that the advantage of higher
+magnetic field in separation efficiency decreases with the increase of
+saturation magnetization of magnetic mineral.",1611.09481v1
+2017-12-26,Magnetic field amplification by the r-mode instability,"We discuss magnetic field enhancement by unstable r-modes (driven by the
+gravitational radiation reaction force) in rotating stars. In the absence of a
+magnetic field, gravitational radiation exponentially increases the r-mode
+amplitude $\alpha$, and accelerates differential rotation (secular motion of
+fluid elements). For a magnetized star, differential rotation enhances the
+magnetic field energy. Rezzolla et al. (2000--2001) argued that if the magnetic
+energy grows faster than the gravitational radiation reaction force pumps
+energy into the r-modes, then the r-mode instability is suppressed. Chugunov
+(2015) demonstrated that without gravitational radiation, differential rotation
+can be treated as a degree of freedom decoupled from the r-modes and controlled
+by the back reaction of the magnetic field. In particular, the magnetic field
+windup does not damp r-modes. Here we discuss the effect of the back reaction
+of the magnetic field on differential rotation of unstable r-modes, and show
+that it limits the generated magnetic field and the magnetic energy growth rate
+preventing suppression of the r-mode instability by magnetic windup at low
+saturation amplitudes, $\alpha \ll 1$, predicted by current models.",1712.09224v1
+2019-07-12,New method for characterization of magnetic nanoparticles by scanning magnetic microscopy,"In this paper, we present a new method for the magnetic characterization of
+bulk materials, microstructures, and nanostructures. We investigated the
+magnetic and morphological properties of two colloidal dispersions of iron
+oxide (Fe3O4) magnetic nanoparticles (MNPs), synthesized by chemical
+precipitation (co-precipitation) and pulsed laser ablation (PLA) in liquid, by
+scanning magnetic microscopy (SMM) applied to a small sample with mass on the
+order of tens of {\mu}g. We evaluated the performance of this technique by
+comparing magnetization curves and measurements obtained with commercial
+magnetometers, considered standard. The errors obtained for the saturation and
+remanent magnetization were approximately 0.18 Am2/kg and 0.6 Am2/kg,
+respectively. The average size distribution of the NPs estimated from the
+magnetization curve measurements is consistent with the results obtained by
+traditional transmission electron microscopy (TEM). The technique can be
+extended to measure and analyze magnetization curves (hysteresis loops), thus
+enabling an even more accurate estimation of overall NP sizes.",1907.05908v1
+2009-11-23,Open and closed boundaries in large-scale convective dynamos,"Context. Earlier work has suggested that large-scale dynamos can reach and
+maintain equipartition field strengths on a dynamical time scale only if
+magnetic helicity of the fluctuating field can be shed from the domain through
+open boundaries. Aims. Our aim is to test this scenario in convection-driven
+dynamos by comparing results for open and closed boundary conditions. Methods.
+Three-dimensional numerical simulations of turbulent compressible convection
+with shear and rotation are used to study the effects of boundary conditions on
+the excitation and saturation of large-scale dynamos. Open (vertical-field) and
+closed (perfect-conductor) boundary conditions are used for the magnetic field.
+The shear flow is such that the contours of shear are vertical, crossing the
+outer surface, and are thus ideally suited for driving a shear-induced magnetic
+helicity flux. Results. We find that for given shear and rotation rate, the
+growth rate of the magnetic field is larger if open boundary conditions are
+used. The growth rate first increases for small magnetic Reynolds number, Rm,
+but then levels off at an approximately constant value for intermediate values
+of Rm. For large enough Rm, a small-scale dynamo is excited and the growth rate
+of the field in this regime increases as Rm^(1/2). Regarding the nonlinear
+regime, the saturation level of the energy of the total magnetic field is
+independent of Rm when open boundaries are used. In the case of perfect
+conductor boundaries, the saturation level first increases as a function of Rm,
+but then decreases proportional to Rm^(-1) for Rm > 30, indicative of
+catastrophic quenching. These results suggest that the shear-induced magnetic
+helicity flux is efficient in alleviating catastrophic quenching when open
+boundaries are used. The horizontally averaged mean field is still weakly
+decreasing as a function of Rm even for open boundaries.",0911.4120v2
+2023-06-12,"Transition from small-scale to large-scale dynamo in a supernova-driven, multiphase medium","Magnetic fields are widely recognised as critical at many scales to galactic
+dynamics and structure, including multiphase pressure balance, dust processing,
+and star formation. Using imposed magnetic fields cannot reliably model the
+interstellar medium's (ISM) dynamical structure nor phase interactions. Dynamos
+must be modelled. ISM models exist of turbulent magnetic fields using
+small-scale dynamo (SSD). Others model the large-scale dynamo (LSD) organising
+magnetic fields at scale of the disc or spiral arms. Separately, neither can
+fully describe the galactic magnetic field dynamics nor topology. We model the
+LSD and SSD together at sufficient resolution to use the low explicit
+Lagrangian resistivity required. The galactic SSD saturates within 20 Myr. We
+show that the SSD is quite insensitive to the presence of an LSD and is even
+stronger in the presence of a large-scale shear flow. The LSD grows more slowly
+in the presence of SSD, saturating after 5 Gyr vs. 1--2 Gyr in studies where
+the SSD is weak or absent. The LSD primarily grows in warm gas in the galactic
+midplane. Saturation of the LSD occurs due to ${\alpha}$-quenching near the
+midplane as the growing mean field produces a magnetic ${\alpha}$ that opposes
+the kinetic ${\alpha}$. The magnetic energy in our models of the LSD shows
+slightly sublinear response to increasing resolution, indicating that we are
+converging towards the physical solution at 1 pc resolution. Clustering
+supernovae in OB associations increases the growth rates for both the SSD and
+the LSD, compared to a horizontally uniform supernova distribution.",2306.07051v3
+2007-02-26,A solar surface dynamo,"Context: Observations indicate that the `quiet' solar photosphere outside
+active regions contains considerable amounts of magnetic energy and magnetic
+flux, with mixed polarity on small scales. The origin of this flux is unclear.
+Aims: We test whether local dynamo action of the near-surface convection
+(granulation) can generate a significant contribution to the observed magnetic
+flux. Methods: We have carried out MHD simulations of solar surface convection,
+including the effects of strong stratification, compressibility, partial
+ionization, radiative transfer, as well as an open lower boundary. Results:
+Exponential growth of a weak magnetic seed field (with vanishing net flux
+through the computational box) is found in a simulation run with a magnetic
+Reynolds number of about 2600. The magnetic energy approaches saturation at a
+level of a few percent of the total kinetic energy of the convective motions.
+Near the visible solar surface, the (unsigned) magnetic flux density reaches at
+least a value of about 25 G. Conclusions: A realistic flow topology of
+stratified, compressible, non-helical surface convection without enforced
+recirculation is capable of turbulent local dynamo action near the solar
+surface.",0702681v1
+2002-05-28,"Ferromagnetism in (In,Mn)As Diluted Magnetic Semiconductor Thin Films Grown by Metalorganic Vapor Phase Epitaxy","In1-xMnxAs diluted magnetic semiconductor (DMS) thin films have been grown
+using metalorganic vapor phase epitaxy (MOVPE).
+Tricarbonyl(methylcyclopentadienyl)manganese was used as the Mn source.
+Nominally single-phase, epitaxial films were achieved with Mn content as high
+as x=0.14 using growth temperatures Tg>475 C. For lower growth temperatures and
+higher Mn concentrations, nanometer scale MnAs precipitates were detected
+within the In1-xMnxAs matrix. Magnetic properties of the films were
+investigated using a superconducting quantum interference device (SQUID)
+magnetometer. Room-temperature ferromagnetic order was observed in a sample
+with x=0.1. Magnetization measurements indicated a Curie temperature of 333 K
+and a room-temperature saturation magnetization of 49 emu/cm^3. The remnant
+magnetization and the coercive field were small, with values of 10 emu/cm^3 and
+400 Oe, respectively. A mechanism for this high-temperature ferromagnetism is
+discussed in light of the recent theory based on the formation of small
+clusters of a few magnetic atoms.",0205602v1
+2003-01-27,Specific Heat of the S=1/2 Two-Dimensional Shastry-Sutherland Antiferromagnet SrCu2(BO3)2 in High Magnetic Fields,"We characterize the field-induced magnetic phases of SrCu2(BO3)2, a
+frustrated spin-1/2 Heisenberg antiferromagnet in the two-dimensional
+Shastry-Sutherland lattice, using specific heat in magnetic fields up to 33 T.
+We find that the spin gap persists above the expected critical field Hc =
+Delta/g*mu_B of 21 T despite the appearance of magnetic moment in the ground
+state. At the magnetization plateau at 1/8 of the saturation, the Sz = +1
+triplets that carry the magnetization of the ground state are observed to form
+a two-dimensional spin gas of massive bosons. A spin gas consisting of the same
+number of massive particles continues to completely dominate the specific heat
+in the field region above the plateau, although the magnetization increases
+with increasing field. Ordering is observed at a temperature immediately below
+the spin-gas regime.",0301509v3
+2004-04-05,Distribution of the sheet current in a magnetically shielded superconducting filament,"The distribution of the transport current in a superconducting filament
+aligned parallel to the flat surface of a semi-infinite bulk magnet is studied
+theoretically. An integral equation governing the current distribution in the
+Meissner state of the filament is derived and solved numerically for various
+filament-magnet distances and different relative permeabilities. This reveals
+that the current is depressed on the side of the filament adjacent to the
+surface of the magnet and enhanced on the averted side. Substantial current
+redistributions in the filament can already occur for low values of the
+relative permeability of the magnet, when the distance between the filament and
+the magnet is short, with evidence of saturation at moderately high values of
+this quantity, similar to the findings for magnetically shielded strips.",0404094v1
+2004-04-13,Quantum kagome antiferromagnet in a magnetic field: Low-lying non-magnetic excitations versus valence-bond crystal order,"We study the ground state properties of a quantum antiferromagnet on the
+kagome lattice in the presence of a magnetic field, paying particular attention
+to the stability of the plateau at magnetization 1/3 of saturation and the
+nature of its ground state. We discuss fluctuations around classical ground
+states and argue that quantum and classical calculations at the harmonic level
+do not lead to the same result in contrast to the zero-field case. For spin
+S=1/2 we find a magnetic gap below which an exponential number of non-magnetic
+excitations are present. Moreover, such non-magnetic excitations also have a
+(much smaller) gap above the three-fold degenerate ground state. We provide
+evidence that the ground state has long-range order of valence-bond crystal
+type with nine spins in the unit cell.",0404279v2
+2004-05-07,Magnetic properties and magnetostructural phase transitions in Ni2+xMn1-xGa shape memory alloys,"A systematic study of magnetic properties of Ni2+xMn1-xGa (0 \le x \le 0.19)
+Heusler alloys undergoing structural martensite-austenite transformations while
+in ferromagnetic state has been performed. From measurements of spontaneous
+magnetization, Ms(T), jumps \Delta M at structural phase transitions were
+determined. Virtual Curie temperatures of the martensite were estimated from
+the comparison of magnetization in martensitic and austenitic phases. Both
+saturation magnetic moments in ferromagnetic state and effective magnetic
+moments in paramagnetic state of Mn and Ni atoms were estimated and the
+influence of delocalization effects on magnetism in these alloys was discussed.
+The experimental results obtained show that the shift of martensitic transition
+temperature depends weakly on composition. The values of this shift are in good
+correspondence with Clapeyron-Clausius formalism taking into account the
+experimental data on latent heat at martensite-austenite transformations.",0405134v1
+2005-05-30,Spin Disorder and Magnetic Anisotropy in Fe3O4 Nanoparticles,"We have studied the magnetic behavior of dextran-coated magnetite
+(Fe$_3$O$_4$) nanoparticles with median particle size $\left<d\right>=8$ $nm$.
+Magnetization curves and in-field M\""ossbauer spectroscopy measurements showed
+that the magnetic moment $M_S$ of the particles was much smaller than the bulk
+material. However, we found no evidence of magnetic irreversibility or
+non-saturating behavior at high fields, usually associated to spin canting. The
+values of magnetic anisotropy $K_{eff}$ from different techniques indicate that
+surface or shape contributions are negligible. It is proposed that these
+particles have bulk-like ferrimagnetic structure with ordered A and B
+sublattices, but nearly compensated magnetic moments. The dependence of the
+blocking temperature with frequency and applied fields, $T_B(H,\omega)$,
+suggests that the observed non-monotonic behavior is governed by the strength
+of interparticle interactions.",0505682v5
+2005-05-29,Dynamical Aspects of Photoinduced Magnetism and Spin-Crossover phenomena in Prussian Blue Analogs,"We present dynamical properties of spin crossover compounds with
+photomagnetization, proposing a new model in which the spin-crossover phenomena
+and magnetic ordering are incorporated in a unified way. By using this model,
+the novel characteristics observed in Prussian blue analogs are qualitatively
+well reproduced. We investigate the time evolution of the magnetization and
+high spin fraction taking into account multi-time scales in a master equation
+approach for the magnetic relaxation, the lattice (electronic) relaxation, and
+the photoexcitation process. In particular, processes with different
+temperature cycles starting from the photoinduced saturated magnetic state are
+studied including the effect of photoirradiation. In the temperature cycle in
+the low temperature region where the high spin state has a strong
+metastability, the magnetization almost exactly follows the quasi-static
+process. On the other hand, when the temperature is raised above the region,
+the dynamics of the spin state and the magnetization couple and exhibit various
+types of dynamical cooperative phenomena under time-dependent control of
+temperature and photoirradiation.",0505702v1
+2006-06-26,Epitaxial film growth and magnetic properties of Co_2FeSi,"We have grown thin films of the Heusler compound Co_2FeSi by RF magnetron
+sputtering. On (100)-oriented MgO substrates we find fully epitaxial
+(100)-oriented and L2_1 ordered growth. On Al_2O_3 (11-20) substrates, the film
+growth is (110)-oriented, and several in-plane epitaxial domains are observed.
+The temperature dependence of the electrical resistivity shows a power law with
+an exponent of 7/2 at low temperatures. Investigation of the bulk magnetic
+properties reveals an extrapolated saturation magnetization of 5.0 mu_B/fu at 0
+K. The films on Al_2O_3 show an in-plane uniaxial anisotropy, while the
+epitaxial films are magnetically isotropic in the plane. Measurements of the
+X-ray magnetic circular dichroism of the films allowed us to determine element
+specific magnetic moments. Finally we have measured the spin polarization at
+the surface region by spin-resolved near-threshold photoemission and found it
+strongly reduced in contrast to the expected bulk value of 100%. Possible
+reasons for the reduced magnetization are discussed.",0606666v2
+2006-10-19,Bose-Einstein condensation of magnons in magnets with predominant ferromagnetic interaction,"We discuss Bose-Einstein condensation of magnons (BEC) in magnets with
+predominant ferromagnetic (FM) interaction in magnetic field $H$ near
+saturation ($H_c$). Because $H_c$ is independent of FM couplings, magnetic
+materials of this type can have small $H_c$ that makes them promising
+candidates for experimental investigation of BEC. Ferromagnets with easy-plane
+anisotropy and antiferromagnets (AFs) containing weakly coupled FM planes or
+chains are discussed in detail. We observe small effective interaction between
+magnons near the QCP in such magnets, in contrast to AFs with strong AF
+coupling previously discussed. In particular, this smallness allows us to find
+crossovers in the critical temperature $T_c(H)\propto (H_c-H)^{1/\phi}$ from
+$\phi=3/2$ to $\phi=1$ in quasi-1D magnets, and from $\phi=3/2$ to
+$\phi\approx1$ ($T_c\ln T_c\propto H_c-H$) in quasi-2D ones.",0610536v4
+2007-07-23,"Magnetocrystalline anisotropy controlled local magnetic configurations in (Ga,Mn)As spin-transfer-torque microdevices","The large saturation magnetization in conventional dense moment ferromagnets
+offers flexible means of manipulating the ordered state through demagnetizing
+shape anisotropy fields but these dipolar fields, in turn, limit the
+integrability of magnetic elements in information storage devices. We show that
+in a (Ga,Mn)As dilute moment ferromagnet, with comparatively weaker magnetic
+dipole interactions, locally tunable magnetocrystalline anisotropy can take the
+role of the internal field which determines the magnetic configuration.
+Experiments and theoretical modeling are presented for lithographically
+patterned microchannels and the phenomenon is attributed to lattice relaxations
+across the channels. The utility of locally controlled magnetic anisotropies is
+demonstrated in current induced switching experiments. We report structure
+sensitive, current induced in-plane magnetization switchings well below the
+Curie temperature at critical current densities 10^5 Acm^-2. The observed
+phenomenology shows signatures of a contribution from domain-wall
+spin-transfer-torque effects.",0707.3329v1
+2007-12-04,Magnetic structure and phase diagram of TmB4,"Magnetic structure of single crystalline TmB4 has been studied by
+magnetization, magnetoresistivity and specific heat measurements. A complex
+phase diagram with different antiferromagnetic (AF) phases was observed below
+TN1 = 11.7 K. Besides the plateau at half-saturated magnetization (1/2 MS),
+also plateaus at 1/9, 1/8 and 1/7 of MS were observed as function of applied
+magnetic field B//c. From additional neutron scattering experiments on TmB4, we
+suppose that those plateaus arise from a stripe structure which appears to be
+coherent domain boundaries between AF ordered blocks of 7 or 9 lattice
+constants. The received results suggest that the frustration among the Tm3+
+magnetic ions, which maps to a geometrically frustrated Shastry-Sutherland
+lattice lead to strong competition between AF and ferromagnetic (FM) order.
+Thus, stripe structures in intermediate field appear to be the best way to
+minimize the magnetostatic energy against other magnetic interactions between
+the Tm ions combined with very strong Ising anisotropy.",0712.0519v1
+2007-12-13,Breakdown of an intermediate plateau in the magnetization process of anisotropic spin-1 Heisenberg dimer: theory vs. experiment,"The magnetization process of the spin-1 Heisenberg dimer model with axial and
+rhombic single-ion anisotropy terms is particularly investigated in connection
+with recent experimental high-field measurements performed on the
+single-crystal sample of the homodinuclear nickel(II) compound
+[Ni2(Medpt)2(ox)(H2O)2](ClO4)2.2H2O (Medpt=methyl-bis(3-aminopropyl)amine). The
+results obtained from the exact numerical diagonalization reveal a striking
+magnetization process with a marked spatial dependence on the applied magnetic
+field for arbitrary but non-zero single-ion anisotropy. It is demonstrated that
+the field range, which corresponds to an intermediate magnetization plateau
+emerging at a half of the saturation magnetization, basically depends on
+single-ion anisotropy terms as well as a spatial orientation of the applied
+field. The breakdown of the intermediate magnetization plateau is discussed at
+length in relation to the single-ion anisotropy strength.",0712.2109v2
+2008-06-06,Magnetic moment of hyperons in nuclear matter by using quark-meson coupling models,"We calculate the magnetic moments of hyperons in dense nuclear matter by
+using relativistic quark models. Hyperons are treated as MIT bags, and the
+interactions are considered to be mediated by the exchange of scalar and vector
+mesons which are approximated as mean fields. Model dependence is investigated
+by using the quark-meson coupling model and the modified quark-meson coupling
+model; in the former the bag constant is independent of density and in the
+latter it depends on density. Both models give us the magnitudes of the
+magnetic moments increasing with density for most octet baryons. But there is a
+considerable model dependence in the values of the magnetic moments in dense
+medium. The magnetic moments at the nuclear saturation density calculated by
+the quark meson coupling model are only a few percents larger than those in
+free space, but the magnetic moments from the modified quark meson coupling
+model increase more than 10% for most hyperons. The correlations between the
+bag radius of hyperons and the magnetic moments of hyperons in dense matter are
+discussed.",0806.1099v2
+2008-07-11,Magnetic interactions and high-field properties of Ag(2)VOP(2)O(7): frustrated alternating chain close to the dimer limit,"We report on high-field magnetic properties of the silver vanadium phosphate
+Ag(2)VOP(2)O(7). This compound has a layered crystal structure, but the
+specific topology of the V-P-O framework gives rise to a one-dimensional spin
+system, a frustrated alternating chain. Low-field magnetization measurements
+and band structure calculations show that Ag(2)VOP(2)O(7) is close to the dimer
+limit with the largest nearest-neighbor interaction of about 30 K. High-field
+magnetization data reveal the critical fields \mu_0H_{c1} of about 23 T
+(closing of the spin gap) and \mu_0H_{c2} of about 30 T (saturation by full
+alignment of the magnetic moments). From H_{c1} to H_{c2} the magnetization
+increases sharply similar to the system of isolated dimers. Thus, the magnetic
+frustration in Ag(2)VOP(2)O(7) bears little influence on the high-field
+properties of this compound.",0807.1849v1
+2008-08-20,Low-temperature magnetic ordering in SrEr$_2$O$_4$,"SrEr$_2$O$_4$ has been characterised by low-temperature powder neutron
+diffraction, as well as single crystal specific heat and magnetisation
+measurements. Magnetisation measurements show that the magnetic system is
+highly anisotropic at temperature above ordering. A magnetic field of 280 kOe
+applied at $T=1.6$ K does not overcome the anisotropic magnetisation and fails
+to fully saturate the system. Long range antiferromagnetic ordering develops
+below $T_N=0.75$ K, identified by magnetic Bragg reflections with propagation
+vector ${\bf k}=0$ and a lambda anomaly in the specific heat. The magnetic
+structure consists of ferromagnetic chains running along the \textit{c} axis,
+two adjacent chains being stacked antiferromagnetically. The moments point
+along the \textit{c} direction, but only one of the two crystallographically
+in-equivalent Er sites has a sizeable ordered magnetic moment, 4.5 $\rm \mu_B$
+at 0.55 K. The magnetic properties of SrEr$_2$O$_4$ are discussed in terms of
+the interplay between the low-dimensionality, competing exchange interactions,
+dipolar interactions and low lying crystal field levels.",0808.2675v1
+2008-11-21,Magnetic Domains and Surface Effects in Hollow Maghemite Nanoparticles,"In the present work, we investigate the magnetic properties of ferrimagnetic
+and noninteracting maghemite (g-Fe2O3) hollow nanoparticles obtained by the
+Kirkendall effect. From the experimental characterization of their magnetic
+behavior, we find that polycrystalline hollow maghemite nanoparticles are
+characterized by low superparamagnetic-to-ferromagnetic transition
+temperatures, small magnetic moments, significant coercivities and
+irreversibility fields, and no magnetic saturation on external magnetic fields
+up to 5 T. These results are interpreted in terms of the microstructural
+parameters characterizing the maghemite shells by means of an atomistic Monte
+Carlo simulation of an individual spherical shell model. The model comprises
+strongly interacting crystallographic domains arranged in a spherical shell
+with random orientations and anisotropy axis. The Monte Carlo simulation allows
+discernment between the influence of the structure polycrystalline and its
+hollow geometry, while revealing the magnetic domain arrangement in the
+different temperature regimes.",0811.3592v2
+2009-03-15,Direct Observation of Magnetic Gradient in Co/Pd Pressure-Graded Media,"Magnetometry and neutron scattering have been used to study the magnetic
+properties of pressure graded Co/Pd multilayers. The grading of the multilayer
+structure was done by varying the deposition pressure during sputtering of the
+samples. Magnetic depth profiling by polarized neutron reflectometry directly
+shows that for pressure-graded samples, the magnetization changes significantly
+from one pressure region to the next, while control samples sputtered at
+uniform pressure exhibit essentially uniform magnetic depth profiles.
+Complementary magnetometry results suggest that the observed graded magnetic
+profiles are due in part to a decrease in saturation magnetization for regions
+deposited at progressively higher pressure. Increased deposition pressure is
+shown to increase coercivity, and for graded samples, the absence of discrete
+steps in the hysteresis loops implies exchange coupling among regions deposited
+at different pressures.",0903.2650v1
+2009-08-15,Thermal-magnetic noise measurement of spin-torque effects on ferromagnetic resonance in MgO-based magnetic tunnel junctions,"Thermal-magnetic noise at ferromagnetic resonance (T-FMR) can be used to
+measure magnetic perpendicular anisotropy of nanoscale magnetic tunnel
+junctions (MTJs). For this purpose, T-FMR measurements were conducted with an
+external magnetic field up to 14 kOe applied perpendicular to the film surface
+of MgO-based MTJs under a dc bias. The observed frequency-field relationship
+suggests that a 20 A CoFeB free layer has an effective demagnetization field
+much smaller than the intrinsic bulk value of CoFeB, with 4PiMeff = (6.1 +/-
+0.3) kOe. This value is consistent with the saturation field obtained from
+magnetometry measurements on extended films of the same CoFeB thickness.
+In-plane T-FMR on the other hand shows less consistent results for the
+effective demagnetization field, presumably due to excitations of more complex
+modes. These experiments suggest that the perpendicular T-FMR is preferred for
+quantitative magnetic characterization of nanoscale MTJs.",0908.2164v1
+2009-09-24,The critical role of magnetic helicity in astrophysical large-scale dynamos,"The role of magnetic helicity in astrophysical large-scale dynamos is
+reviewed and compared with cases where there is no energy supply and an initial
+magnetic field can only decay. In both cases magnetic energy tends to get
+redistributed to larger scales. Depending on the efficiency of magnetic
+helicity fluxes, the decay of a helical field can speed up. Likewise, the
+saturation of a helical dynamo can speed up through magnetic helicity fluxes.
+The astrophysical importance of these processes is reviewed in the context of
+the solar dynamo and an estimated upper limit for the magnetic helicity flux of
+10^46 Mx^2/cycle is given.",0909.4377v1
+2010-01-02,Surface magnetic states of Ni nanochains modified by using different organic surfactants,"Three powder samples of Ni nanochains formed of polycrystalline Ni
+nanoparticles with an estimated diameter of about 30 nm have been synthesized
+by a wet chemical method using different organic surfactants. These samples,
+having magnetically/structurally core-shell structures, all with a
+ferromagnetic Ni core, are Ni@Ni3C nanochains, Ni@NiSG nanochains with a spin
+glass (SG) surface layer, and Ni@NiNM nanochains with a nonmagnetic (NM)
+surface layer. The average thickness of the shell for these three samples is
+determined as about 2 nm. Magnetic properties tailored by the different surface
+magnetism are studied. In particular, suppression in saturation magnetization
+usually observed with magnetic nanoparticles is revealed to arise from the
+surface magnetic states with the present samples.",1001.0298v1
+2010-04-13,Numerical study of magnetization processes in rare-earth tetraborides,"We present a simple model for a description of magnetization processes in
+rare-earth tetraborides. The model is based on the coexistence of two
+subsystems, and namely, the spin subsystem described by the Ising model and the
+electronic subsystem described by the Falicov-Kimball model on the
+Shastry-Sutherland lattice (SSL). Moreover, both subsystems are coupled by the
+anisotropic spin-dependent interaction of the Ising type. We have found, that
+the switching on the spin-dependent interaction ($J_z$) between the electron
+and spin subsystems and taking into account the electron hopping on the nearest
+($t$) and next-nearest ($t'$) lattice sites of the SSL leads to a stabilization
+of new magnetization plateaus. In addition, to the Ising magnetization plateau
+at $m^{sp}/m_s^{sp}=1/3$ we have found three new magnetization plateaus located
+at $m^{sp}/m_s^{sp}=1/2$, 1/5 and 1/7 of the saturated spin magnetization
+$m_s^{sp}$. The ground-states corresponding to magnetization plateaus have the
+same spin structure consisting of parallel antiferromagnetic bands separated by
+ferromagnetic stripes.",1004.2128v1
+2010-05-20,Metastable magnetization behavior in magnetocaloric R6Co1.67Si3 (R=Tb and Nd) compounds,"Magnetic field and time induced steps have been observed in the recently
+discovered ternary silicide R6Co1.67Si3. Huge relaxation steps are observed
+across different loops in the low temperature magnetization isotherms. Giant
+relaxation present in this system indicates the existence of incubation time to
+get the saturated moment at a certain field. Measurement protocol sensitive
+magnetization behavior observed in this system may arise from the strong
+magnetostructural coupling and/or magnetic frustration. Electrical resistivity
+and magnetoresistance also reflect the magnetic state of the compound.
+Magnetocaloric effect is found to be large at temperatures close to the
+magnetic transition temperature.",1005.3671v1
+2010-12-22,Magnetic Structure in Fe/Sm-Co Exchange Spring Bilayers with Intermixed Interfaces,"The depth profile of the intrinsic magnetic properties in an Fe/Sm-Co bilayer
+fabricated under nearly optimal spring-magnet conditions was determined by
+complementary studies of polarized neutron reflectometry and micromagnetic
+simulations. We found that at the Fe/Sm-Co interface the magnetic properties
+change gradually at the length scale of 8 nm. In this intermixed interfacial
+region, the saturation magnetization and magnetic anisotropy are lower and the
+exchange stiffness is higher than values estimated from the model based on a
+mixture of Fe and Sm-Co phases. Therefore, the intermixed interface yields
+superior exchange coupling between the Fe and Sm-Co layers, but at the cost of
+average magnetization.",1012.5086v1
+2011-03-30,Giant coercivity of dense nanostructured spark plasma sintered barium hexaferrite,"Due to the limited rare-earth elements resources, ferrite magnets need to be
+improved drastically. Ideally, for a true hard magnet, the coercive field
+should be larger than the saturation magnetization, which is not yet realized
+for ferrites. Thus, an alternative can be found in making very fine grain
+ferrite magnets, but it is usually impossible to get small grains and dense
+material together. In this paper, it is shown that the spark plasma sintering
+method is able to produce approximately 80% of dense material with crystallites
+smaller than 100 nm. The as-prepared bulk sintered anisotropic magnets exhibits
+coercive field of 0.5 T which is approximately 60% of the theoretical limit and
+only a few percentage below that of loose nanopowders. As a result, the magnets
+behave nearly ideal (-1.18 slope in the BH plane second quadrant) and the
+energy product reaches 8.8 kJ m-3, the highest value achieved in the isotropic
+ferrite magnet to our knowledge.",1103.5840v1
+2011-08-08,Dimensional crossover in spin-1 Heisenberg antiferromagnets: a quantum Monte Carlo study,"We present results of large scale simulations of the spin-1 Heisenberg
+antiferromagnet on a tetragonal lattice. The stochastic series expansion
+quantum Monte Carlo method is used to calculate equilibrium thermodynamic
+variables in the presence of an external magnetic field. In particular, the low
+temperature magnetization curve is investigated in the quasi-one-dimensional
+(Q1D), quasi-two-dimensional (Q2D), and three-dimensional (3D) limits. Starting
+from the 3D limit, the Q1D (Q2D) limit is achieved by reducing the in-plane
+(out-of-plane) spin coupling strength towards zero. In the Q1D limit, a Haldane
+gap appears in the magnetization curve at low magnetic field. Additionally,
+near the saturation field the slope of the magnetization curve increases
+substantially, approaching the infinite-slope behavior of a one-dimensional
+spin-1 chain. A similar (though less pronounced) effect is seen in the Q2D
+limit. We also study the effect of uniaxial single-ion anisotropy on the
+magnetization curve for Q1D and Q2D systems. Our results will be important in
+understanding the field-induced behavior of a class of low-dimensional Ni-based
+quantum magnets.",1108.1648v1
+2011-12-05,Magnetic field estimates for accreting neutron stars in massive binary systems and models of magnetic field decay,"Some modern models of neutron star evolution predict that initially large
+magnetic fields rapidly decay down to some saturation value $\sim {\rm
+few}\times 0^{13}$ G and weaker magnetic fields do not decay significantly
+(Pons). It is difficult to check the predictions of this model for initially
+highly magnetized objects on the time scale of a few million years. We propose
+to use Be/X-ray binaries for this purpose. We apply several methods to estimate
+magnetic fields of neutron stars in these accreting systems using the data
+obtained by the RXTE satellite (Galache). Only using the most modern approach
+for estimating the magnetic field strengths of long period NSs as proposed by
+Shakura we are able to obtain a field distribution compatible with predictions
+of the theoretical model of field decay of Pons.",1112.1123v2
+2012-06-22,How is the magnetic reconnection derived from magnetohydrodynamics equations?,"We clarify how magnetic reconnection can be derived from magnetohydrodynamics
+(MHD) equations in a way that is easily understandable to university students.
+The essential mechanism governing the time evolution of the magnetic field is
+diffusion dynamics. The magnetic field is represented by two components. It is
+clarified that the diffusion of a component causes a generation of another
+component that is initially zero and, accordingly, that the magnetic force
+lines are reconnected. For this reconnection to occur correctly, the initial
+magnetic field must be directed oppositely in the two regions, e.g., $y>0$ and
+$y<0$; must be concave (convex) for $y>0$ ($y<0$); and must be saturated for
+$y$ far from the x axis, which would indicate the existence of the current
+sheet. It will be clear that our comprehension based on diffusion runs parallel
+to the common qualitative explanation about the magnetic reconnection.",1206.5161v1
+2013-05-29,Enhanced interface perpendicular magnetic anisotropy in Ta|CoFeB|MgO using nitrogen doped Ta underlayers,"We show that the magnetic characteristics of Ta|CoFeB|MgO magnetic
+heterostructures are strongly influenced by doping the Ta underlayer with
+nitrogen. In particular, the saturation magnetization drops upon doping the Ta
+underlayer, suggesting that the doped underlayer acts as a boron diffusion
+barrier. In addition, the thickness of the magnetic dead layer decreases with
+increasing nitrogen doping. Surprisingly, the interface magnetic anisotropy
+increases to ~1.8 erg/cm2 when an optimum amount of nitrogen is introduced into
+the Ta underlayer. These results show that nitrogen doped Ta serves as a good
+underlayer for Spintronics applications including magnetic tunnel junctions and
+domain wall devices.",1305.6660v1
+2013-08-30,Magnetocapacitance as a sensitive probe of magnetostructural changes in NiCr$_2$O$_4$,"The spinel NiCr$_2$O$_4$ is characterized using dielectric and high magnetic
+field measurements. The trends in the magnetodielectric response fall into
+three clear temperature regimes corresponding to known magnetic and structural
+transitions. Above 65\,K, weak magnetic field dependence of the dielectric
+constant is observed with no hysteresis. When 30\,K\,$\leq\,T\,\leq$\,65\,K, a
+strong dependence of the dielectric constant on the magnetic field is observed
+and hysteresis develops resulting in so called butterfly loops. Below 30\,K,
+magnetodielectric hysteresis is enhanced. Magnetodielectric hysteresis mirrors
+magnetic hysteresis suggesting that spin-spin interactions are the mechanism
+for the magnetoelectric effect in NiCr$_2$O$_4$. At high fields however, the
+magnetization continues to increase while the dielectric constant saturates.
+Magnetodielectric measurements of NiCr$_2$O$_4$ suggest an additional,
+previously unobserved transition at 20\,K. Subtle changes in magnetism and
+structure suggest that this 20\,K anomaly corresponds to the completion of
+ferrimagnetic ordering and the spin driven structural distortion. We
+demonstrate that magnetocapacitance is a sensitive probe of magnetostructural
+distortion.",1309.0016v1
+2014-01-22,Cooling a magnetic nanoisland by spin-polarized currents,"We investigate cooling of a vibrational mode of a magnetic quantum dot by a
+spin-polarized tunneling charge current, exploiting the interaction between the
+magnetization and the vibration. The spin-polarized charge current polarizes
+the magnetic nanoisland, lowering its energy. Inevitable Ohmic energy losses
+due to the charge current flow will heat up the vibration. A small but finite
+coupling between the vibration and the local magnetic moment then permits an
+energy exchange, resulting in a lower energy, i.e., cooling, of the vibrational
+mode. We determine parameter regimes for the cooling of the vibration below
+$50\%$ of its initial value. Lowest final phonon temperature is observed for
+weak electron-phonon-coupling but similar magnetization-phonon coupling
+strength. The cooling rate, thereby, increases at first with the
+magnetization-phonon coupling and then saturates.",1401.5724v3
+2014-03-24,Magnetic structure and dynamics of a strongly one-dimensional cobalt$^{II}$ metal-organic framework,"We investigate the magnetism of the
+Co$^{II}_4$(OH)$_2$(C$_1$$_0$H$_1$$_6$O$_4$)$_3$ metal-organic framework which
+displays complex inorganic chains separated from each other by distances of 1
+to 2 nm, and which orders at ~5.4 K. The zero-field magnetic structure is
+determined using neutron powder diffraction: it is mainly antiferromagnetic but
+posseses a ferromagnetic component along the $\textbf{c}$-axis. This magnetic
+structure persists in presence of a magnetic field. Ac susceptibility
+measurements confirm the existence of a single thermally activated regime over
+7 decades in frequency ($E/k_B\approx64 K$) whereas time-dependent relaxation
+of the magnetization after saturation in an external field leads to a two times
+smaller energy barrier. These experiments probe the slow dynamics of domain
+walls within the chains: we propose that the ac measurements are sensitive to
+the motion of existing domain walls within the chains, while the magnetization
+measurements are governed by the creation of domain walls.",1403.5931v1
+2014-07-24,Successive magnetic transitions of Ca$_2$CoSi$_2$O$_7$ in high magnetic fields,"Magnetic and dielectric properties of \aa kermanite Ca$_2$CoSi$_2$O$_7$
+single crystals were investigated in pulsed high magnetic fields. In magnetic
+fields along the $c$ axis, this material shows a magnetization plateau in a
+wide range of field below the saturation. Magnetization processes for fields
+along the $a$ and $b$ axes show multiple anomalies but different traces to each
+other, indicating the breaking of four-fold symmetry. Measurements of the
+magnetoelectric effects exhibit the changes in electric polarization according
+to the changes in the spin system. The experimentally determined quadratic
+magnetoelectric tensor is consistent with that expected in the crystal symmetry
+of orthorhombic $P2_12_12$.",1407.6450v1
+2015-12-24,Spin frustration and magnetic ordering in triangular lattice antiferromagnet Ca$_3$CoNb$_2$O$_9$,"We synthesized a quasi-two-dimensional distorted triangular lattice
+antiferromagnet Ca$_3$CoNb$_2$O$_9$, in which the effective spin of Co$^{2+}$
+is 1/2 at low temperatures, whose magnetic properties were studied by dc
+susceptibility and magnetization techniques. The x-ray diffraction confirms the
+quality of our powder samples. The large Weiss constant $\theta_{CW}\sim$ $-55$
+K and the low Neel temperature($T_N\sim$ 1.45 K) give a frustration factor $f$
+($=\mid\theta_{CW}/T_N \mid$) $\approx$ 38, suggesting that Ca$_3$CoNb$_2$O$_9$
+resides in strong frustration regime. Slightly below $T_N$, deviation between
+the susceptibility data under zero-field cooling (ZFC) and field cooling (FC)
+is observed. A new magnetic state with 1/3 of the saturate magnetization $M_s$
+is suggested in the magnetization curve at 0.46 K. Our study indicates that
+Ca$_3$CoNb$_2$O$_9$ is an interesting material to investigate magnetism in
+triangular lattice antiferromagnets with weak anisotropy.",1512.07792v1
+2016-08-30,Multiple Magnetization Plateaus and the Magnetic Structures in $S=1/2$ Heisenberg Model on the Checkerboard Lattice,"We study the ground state of $S = 1/2$ Heisenberg model on the checkerboard
+lattice in a magnetic field by the density matrix renormalization group (DMRG)
+method with the sine-square deformation. We obtain magnetization plateaus at
+$M/M_{\rm sat}=$0, 1/4, 3/8, 1/2, and 3/4 where $M_{\rm sat}$ is the saturated
+magnetization. The obtained 3/4 plateau state is consistent with the exact
+result, and the 1/2 plateau is found to have a four-spin resonating loop
+structure similar to the six-spin loop structure of the 1/3 plateau of the
+kagome lattice. Different four-spin loop structures are obtained in the 1/4 and
+3/8 plateaus but no corresponding states exist in the kagome lattice. The 3/8
+plateau has a unique magnetic structure of three types of four-spin local
+quantum states in a $4\sqrt{2}\times2\sqrt{2}$ magnetic unit cell with a
+16-fold degeneracy.",1608.08327v1
+2016-10-13,Nanoscale distribution of magnetic anisotropies in bimagnetic soft core-hard shell MnFe$_2$O$_4$@CoFe$_2$O$_4$ nanoparticles,"The nanoscale distribution of magnetic anisotropies was measured in
+core@shell MnFe$_2$O$_4$@CoFe$_2$O$_4$ 7.0 nm particles using a combination of
+element selective magnetic spectroscopies with different probing depths. As
+this picture is not accessible by any other technique, emergent magnetic
+properties were revealed. The coercive field is not constant in a whole
+nanospinel. The very thin (0.5 nm) CoFe$_2$O$_4$ hard shell imposes a strong
+magnetic anisotropy to the otherwise very soft MnFe$_2$O$_4$ core: a large
+gradient in coercivity was measured inside the MnFe$_2$O$_4$ core with lower
+values close to the interface region, while the inner core presents a
+substantial coercive field (0.54 T) and a very high remnant magnetization (90%
+of the magnetization at saturation).",1610.04263v2
+2016-12-16,Macroscopic magnetic field generated in laser atom interaction,"We observe shift in the zero magnetic field resonance as the handedness of
+resonantly interacting circularly polarized light is changed. The
+characteristic of the shift resembles with the Zeeman light shift that arises
+due to interaction of non-resonant circularly polarized light with atom.
+However many attributes of our observed resonant phenomena like dependence on
+buffer gas, saturation of the shift with light intensity and involved time
+constant in evolution of the shift contradicts to the fictitious magnetic field
+model. We propose collective alignment of atomic magnetic moment giving rise to
+a real magnetic field as a possible mechanism behind the observed shift. The
+characteristic changes in the signal profile with respect to the three axis
+magnetic field have been established that can reveal many subtle issues
+pertaining to the phenomenon.",1612.05411v3
+2017-01-07,Magnetization and the Concurrence of the Spin-1/2 Ising-Heisenberg Pyrochlore Ladder,"We have established a quantum antiferromagnetic Heisenberg-Ising model on a
+spin-1/2 pyrochlore edge-shared ladder with Heisenberg intra-rung and Ising
+inter-rung interactions as a perspicuous candidate to exhibit magnetization mid
+and zero plateaus, characteristic peaks of magnetic susceptibility, and thermal
+entanglement mid plateau. The model is exactly solvable and thus, all the
+essential properties such as the thermal entanglement and the magnetic
+properties of the system can be exactly calculated. The calculations are done
+both through the transfer matrix technique and through the reduced density
+matrix. The magnetization plateaus are observed at zero and half the saturation
+value and the magnetic susceptibility exhibits a clear demonstration of the
+associated characteristic peaks. The model also displays the mid plateau of the
+thermal entanglement as a function of the external magnetic field at low
+temperatures.",1701.01880v1
+2017-01-09,"Magnetic properties of ultra-thin 3d transition-metal binary alloys I: spin and orbital moments, anisotropy, and confirmation of Slater-Pauling behavior","The structure and static magnetic properties - saturation magnetization,
+perpendicular anisotropy, spectroscopic g-factor, and orbital magnetization -
+of thin-film 3d transition metal alloys are determined over the full range of
+alloy compositions via X-ray diffraction, magnetometry, and ferromagnetic
+resonance measurements. We determine the interfacial perpendicular magnetic
+anisotropy by use of samples sets with varying thickness for specific alloy
+concentrations. The results agree with prior published data and theoretical
+predictions. They provide a comprehensive compilation of the magnetic
+properties of thin-film Ni-Co, Ni-Fe and Co-Fe alloys that goes well beyond the
+often-cited Slater-Pauling dependence of magnetic moment on alloy
+concentration.",1701.02177v1
+2017-01-10,Current-driven skyrmion expulsion from magnetic nanostrips,"We study the current-driven skyrmion expulsion from magnetic nanostrips using
+micromagnetic simulations and analytic calculations. We explore the threshold
+current density for the skyrmion expulsion, and show that this threshold is
+determined by the critical boundary force as well as the spin-torque
+parameters. We also find the dependence of the critical boundary force on the
+magnetic parameters; the critical boundary force decreases with increasing the
+exchange stiffness and perpendicular anisotropy constants, while it increases
+with increasing Dzyaloshinskii-Moriya interaction and saturation magnetization
+constants. Using a simple model describing the skyrmion and locally-tilted edge
+magnetization, we reveal the underlying physics of the dependence of the
+critical boundary force on the magnetic parameters based on the relation
+between the scaled Dzyaloshinskii-Moriya-interaction parameter and the critical
+boundary force. This work provides a fundamental understanding of the skyrmion
+expulsion and the interaction between the skymion and boundaries of devices and
+shows that the stability of the skyrmion in devices can be related to the
+scaled Dzyaloshinskii-Moriya-interaction parameter of magnetic materials.",1702.05672v2
+2017-03-13,Field dependence of the magnetic correlations of the frustrated magnet SrDy$_2$O$_4$,"The frustrated magnet SrDy$_2$O$_4$ exhibits a field-induced phase with a
+magnetization plateau at $1/3$ of the saturation value for magnetic fields
+applied along the $b$-axis. We report here a neutron scattering study of the
+nature and symmetry of the magnetic order in this field-induced phase. Below
+$T\approx 0.5$ K, there are strong hysteretic effects, and the order is short
+or long ranged for zero-field and field cooling, respectively. We find that the
+long-range ordered magnetic structure within the zig-zag chains is identical to
+that expected for the one-dimensional axial next-nearest neighbour Ising
+(ANNNI) model in longitudinal field. The long-range ordered structure in field
+contrasts with the short-range order found at zero field, and is probably
+reached through enhanced quantum fluctuations with increasing fields.",1703.04430v2
+2017-10-18,Magnetization plateau as a result of the uniform and gradual electron doping in a coupled spin-electron double-tetrahedral chain,"The double-tetrahedral chain in a longitudinal magnetic field, whose nodal
+lattice sites occupied by the localized Ising spins regularly alternate with
+triangular plaquettes with the dynamics described by the Hubbard model, is
+rigorously investigated. It is demonstrated that the uniform change of electron
+concentration controlled by the chemical potential in a combination with the
+competition between model parameters and the external magnetic field leads to
+the formation of one chiral and seven non-chiral phases at the absolute zero
+temperature. Rational plateaux at one-third and one-half of the saturation
+magnetization can also be identified in the low-temperature magnetization
+curves. On the other hand, the gradual electron doping results in eleven
+different ground-state regions which distinguish from each other by the
+evolution of the electron distribution during this process. Several
+doping-dependent magnetization plateaux are observed in the magnetization
+process as a result of the continuous change of electron content in the model.",1710.06822v1
+2017-10-20,Magnetic field amplification in supernova remnants,"Based on the new findings on the turbulent dynamo in \citet{XL16}, we examine
+the magnetic field amplification in the context of supernova remnants. Due to
+the strong ion-neutral collisional damping in the weakly-ionized interstellar
+medium, the dynamo in the preshock turbulence remains in the damping kinematic
+regime, which leads to {\it a linear-in-time growth of the magnetic field
+strength}. The resultant magnetic field structure enables effective diffusion
+upstream and shock acceleration of cosmic rays to energies above the ""knee"".
+Differently, the nonlinear dynamo in the postshock turbulence leads to {\it a
+linear-in-time growth of the magnetic energy} due to the turbulent magnetic
+diffusion. Given a weak initial field strength in the postshock region, the
+magnetic field saturates at a significant distance from the shock front as a
+result of the inefficiency of the nonlinear dynamo. This result is in a good
+agreement with existing numerical simulations and well explains the X-ray spots
+detected far behind the shock front.",1710.07717v1
+2019-09-23,Giant magnetocaloric effect in Co2FeAl Heusler alloy nanoparticles,"A giant magnetocaloric effect across the ferromagnetic (FM) to paramagnetic
+(PM) phase transition was observed in chemically synthesized Co2FeAl Heusler
+alloy nanoparticles with a mean diameter of 16 nm. In our previous report, we
+have observed a significant enhancement in its saturation magnetization (Ms)
+and Curie temperature (Tc) as compared with the bulk counterpart. Motivated
+from those results, here, we aim to explore its magnetocaloric properties near
+the Tc. The magnetic entropy change shows a positive anomaly at 1252 K.
+Magnetic entropy change increases linearly with the magnetic field, and a large
+value of ~15 J/Kg-K is detected under a moderate field of 14 kOe. It leads to a
+net relative cooling power of 89 J/Kg for the magnetic field change of 14 kOe.
+To confirm the nature of magnetic phase transition, a detailed study of its
+magnetization is performed. The Arrott plot and nature of the universal curve
+conclude that FM to PM phase transition in the present system is of
+second-order.",1909.10201v4
+2019-10-23,Computational screening of Fe-Ta hard magnetic phases,"In this work we perform a systematic calculation of the Fe-Ta phase diagram
+to discover novel hard magnetic phases. By using structure prediction methods
+based on evolutionary algorithms, we identify two new energetically stable
+magnetic structures: a tetragonal Fe$_3$Ta (space group 122) and cubic Fe$_5$Ta
+(space group 216) binary phases. The tetragonal structure is estimated to have
+both high saturation magnetization ($\mu_0$M$_s$=1.14 T) and magnetocrystalline
+anisotropy (K$_1$=2.17 MJ/m$^3$) suitable for permanent magnet applications.
+The high-throughput screening of magneto-crystalline anisotropy also reveals
+two low energy metastable hard magnetic phases: Fe$_5$Ta$_2$ (space group 156)
+and Fe$_{6}$Ta (space group 194), that may exhibit intrinsic magnetic
+properties comparable to SmCo$_5$ and Nd$_2$Fe$_{14}$B, respectively.",1910.10531v1
+2019-11-12,Two Coupled Chains are Simpler than One: Field-induced Chirality in a Frustrated Quantum Spin Ladder,"Although the frustrated spin chain (zigzag chain) is a Drosophila of
+frustrated magnetism, the understanding of a pair of coupled zigzag chains
+(frustrated spin ladder) in a magnetic field is incomplete. We address this
+problem through nuclear magnetic resonance (NMR) experiments on
+$\text{BiCu}_2\text{PO}_6$ in magnetic fields up to 45 T, revealing a
+field-induced spiral magnetic structure. Conjointly, we present advanced
+numerical calculations showing that even moderate rung coupling dramatically
+simplifies the phase diagram below half-saturation magnetization by stabilizing
+a field-induced chiral phase. Surprisingly for a one-dimensional model, this
+phase and its response to Dzyaloshinskii-Moriya (DM) interactions adhere to
+classical expectations. While explaining the behavior at the highest accessible
+magnetic fields, our results imply a different origin for the solitonic phases
+occurring at lower fields in $\text{BiCu}_2\text{PO}_6$. An exciting
+possibility is that the known, DM-mediated coupling between chirality and
+crystal lattice gives rise to a new kind of spin-Peierls instability.",1911.05011v1
+2020-01-07,Growth-sequence-dependent interface magnetism of SrIrO$_3$ - La$_{0.7}$Sr$_{0.3}$MnO$_3$ bilayers,"Bilayers of the oxide 3d ferromagnet La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ (LSMO) and
+the 5d paramagnet SrIrO$_{3}$ (SIO) with large spin-orbit coupling (SOC) have
+been investigated regarding the impact of interfacial SOC on magnetic order.
+For the growth sequence of LSMO on SIO, ferromagnetism is strongly altered and
+large out-of-plane-canted anisotropy associated with lacking magnetic
+saturation up to 4 T has been observed. Thin bilayer films have been grown
+coherently in both growth sequences on SrTiO$_3$ (001) by pulsed laser
+deposition and structurally characterized by scanning transmission electron
+microscopy (STEM) and x-ray diffraction (XRD). Measurements of magnetization
+and field-dependent Mn L$_{2,3}$ edge x-ray magnetic circular dichroism (XMCD)
+reveal changes of LSMO magnetic order which are strong in LSMO on SIO and weak
+in LSMO underneath of SIO. We attribute the impact of the growth sequence to
+the interfacial lattice structure/symmetry which is known to influence the
+interfacial magnetic coupling.",2001.02083v1
+2020-03-25,Two-photon driven magnon-pair resonance as a signature of spin-nematic order,"We theoretically study the nonlinear magnetic resonance driven by intense
+laser or electromagnetic wave in a fully polarized frustrated magnet near a
+less-visible spin-nematic ordered phase. In general, both magnons and magnon
+pairs (two-magnon bound state) appear as the low-energy excitation in the
+saturated state of spin-nematic magnets. Their excitation energies are usually
+in terahertz (THz) or gigahertz range. Magnon pairs with angular momentum
+2$\hbar$ can be excited by the simultaneous absorption of two photons, and such
+multi-photon processes occur if the applied THz laser is strong enough. We
+compute laser-driven magnetic dynamics of a frustrated four-spin system with
+both magnon ($\hbar$) and magnon-pair (2$\hbar$) like excitations which is
+analogous to a macroscopic frustrated magnet with a spin nematic phase. We
+estimate the required strength of magnetic field of laser for the realization
+of two photon absorption, taking into account dissipation effects with the
+Lindblad equation. We show that intense THz laser with ac magnetic field of
+0.1-1.0 Tesla is enough to observe magnon-pair resonance.",2003.11240v2
+2020-04-28,Chiral symmetry breaking for deterministic switching of perpendicular magnetization by spin-orbit torque,"Symmetry breaking is a characteristic to determine which branch of a
+bifurcation system follows upon crossing a critical point. Specifically, in
+spin-orbit torque (SOT) devices, a fundamental question arises: how to break
+the symmetry of the perpendicular magnetic moment by the in-plane spin
+polarization? Here, we show that the chiral symmetry breaking by the DMI can
+induce the deterministic SOT switching of the perpendicular magnetization. By
+introducing a gradient of saturation magnetization or magnetic anisotropy,
+non-collinear spin textures are formed by the gradient of effective SOT
+strength, and thus the chiral symmetry of the SOT-induced spin textures is
+broken by the DMI, resulting in the deterministic magnetization switching. We
+introduce a strategy to induce an out-of-plane (z) gradient of magnetic
+properties, as a practical solution for the wafer-scale manufacture of SOT
+devices.",2004.13872v1
+2020-06-29,Domain switching and exchange bias control by electric field in multiferroic conical magnet Mn$_2$GeO$_4$,"The electric field effect on magnetism was examined in the multiferroic
+conical magnet Mn$_2$GeO$_4$, which shows a strong coupling between
+ferromagnetic and ferroelectric order parameters. The systematic evaluation of
+the electric polarization in the multiferroic phase below 5.5 K under various
+field cooling conditions reveals that small magnetic fields of 0.1 T
+significantly reduce the required electric fields needed to reach saturation.
+By applying electric fields during magnetic field dependent hysteresis
+measurements of magnetization M and polarization P an electrically controllable
+exchange bias was observed, a phenomenon exceedingly rare in single phase
+multiferroics. Furthermore, non-reversible electric switching of P and M
+domains was achieved under specific magnetic field conditions.",2006.16080v1
+2020-08-12,Prediction on Properties of Rare-earth 2-17-X Magnets Ce2Fe17-xCoxCN : A Combined Machine-learning and Ab-initio Study,"We employ a combination of machine learning and first-principles calculations
+to predict magnetic properties of rare-earth lean magnets. For this purpose,
+based on training set constructed out of experimental data, the machine is
+trained to make predictions on magnetic transition temperature (Tc), largeness
+of saturation magnetization ({\mu}0Ms), and nature of the magnetocrystalline
+anisotropy (Ku). Subsequently, the quantitative values of {\mu}0Ms and Ku of
+the yet-to-be synthesized compounds, screened by machine learning, are
+calculated by first-principles density functional theory. The applicability of
+the proposed technique of combined machine learning and first-principles
+calculations is demonstrated on 2-17-X magnets, Ce2Fe17-xCoxCN. Further to this
+study, we explore stability of the proposed compounds by calculating vacancy
+formation energy of small atom interstitials (N/C). Our study indicates a
+number of compounds in the proposed family, offers the possibility to become
+solution of cheap, and efficient permanent magnet.",2008.05125v1
+2020-09-24,Phase diagram of multi-layer ferromagnet system with dipole-dipole interaction,"We investigate various magnetic configurations caused by the dipole-dipole
+interaction (DDI) in the thin-film magnet with the perpendicular anisotropy
+under the open boundary conditions. Two different approaches are simulated: one
+starts from a random magnetic configuration and decreases temperatures
+step-wisely; the other starts from the saturated out-of-plane ferromagnetic
+state to evaluate its metastability. As typical patterns of magnetic
+configuration, five typical configurations are found: an out-of-plane
+ferromagnetic, in-plane ferromagnetic, vortex, multi-domain, and canted
+multi-domain states. Notably, the canted multi-domain forms a concentric
+magnetic-domain-pattern with an in-plane vortex structure, resulting from the
+open boundary conditions. Concerning to the coercivity, a comparison of the
+magnetic configurations in both processes reveals that the out-of-plane
+ferromagnetic state exhibits metastability in the multi-domain state, while not
+in the vortex state. We also confirm that the so-called Neel-cap
+magnetic-domain-wall structure, which is originally discussed in the in-plane
+anisotropy system, appears at the multi-domain state.",2009.11574v1
+2021-02-11,Defect-driven ferrimagnetism and hidden magnetization in MnBi$_2$Te$_4$,"MnBi$_2$Te$_4$ (MBT) materials are promising antiferromagnetic topological
+insulators where field driven ferromagnetism is predicted to cause a transition
+between axion insulator and Weyl semimetallic states. However, the presence of
+antiferromagnetic coupling between Mn/Bi antisite defects and the main Mn layer
+can reduce the low-field magnetization, and it has been shown that such defects
+are more prevalent in the structurally identical trivial magnetic insulator
+MnSb$_2$Te$_4$ (MST). We use high-field magnetization measurements to show that
+the magnetization of MBT and MST occur in stages and full saturation requires
+fields of~$\sim$~60 Tesla. As a consequence, the low-field magnetization
+plateau state in MBT, where many determinations of quantum anomalous Hall state
+are studied, actually consists of ferrimagnetic septuple blocks containing both
+a uniform and staggered magnetization component.",2102.05797v2
+2021-03-04,Strange electrical transport: Colossal magnetoresistance via avoiding fully polarized magnetization in ferrimagnetic insulator Mn3Si2Te6,"Colossal magnetoresistance is of great fundamental and technological
+significance and exists mostly in the manganites and a few other materials.
+Here we report colossal magnetoresistance that is starkly different from that
+in all other materials. The stoichiometric Mn3Si2Te6 is an insulator featuring
+a ferrimagnetic transition at 78 K. The resistivity drops by 7 orders of
+magnitude with an applied magnetic field above 9 Tesla, leading to an
+insulator-metal transition at up to 130 K. However, the colossal
+magnetoresistance occurs only when the magnetic field is applied along the
+magnetic hard axis and is surprisingly absent when the magnetic field is
+applied along the magnetic easy axis where magnetization is fully saturated.
+The anisotropy field separating the easy and hard axes is 13 Tesla, unexpected
+for the Mn ions with nominally negligible orbital momentum and spin-orbit
+interactions. Double exchange and Jahn-Teller distortions that drive the
+hole-doped manganites do not exist in Mn3Si2Te6. The phenomena fit no existing
+models, suggesting a unique, intriguing type of electrical transport.",2103.02764v1
+2021-09-13,Gradient soft magnetic materials produced by additive manufacturing from non-magnetic powders,"Additive manufacturing (AM) allows printing parts of complex geometries that
+cannot be produced by standard technologies. Besides, AM provides the
+possibility to create gradient materials with different structural and physical
+properties. We, for the first time, printed gradient soft magnetic materials
+from paramagnetic powders (316L steel and Cu-12Al-2Fe (in wt.%) aluminium
+bronze)). The magnetic properties can be adjusted during the in-situ printing
+process. The saturated magnetization value of alloys reaches 49 emu g^{-1}. The
+changes in the magnetic properties have been attributed to the formation of the
+BCC phase after mixing two FCC-dominated powders. Moreover, the phase
+composition of the obtained gradient materials can be predicted with reasonable
+accuracy by the CALPHAD approach, thus providing efficient optimization of the
+performance. The obtained results provide new prospects for printing gradient
+magnetic alloys.",2109.05947v1
+2022-09-19,Dissipative magnetic structures and scales in small-scale dynamos,"Small-scale dynamos play important roles in modern astrophysics, especially
+on Galactic and extragalactic scales. Owing to dynamo action, purely
+hydrodynamic Kolmogorov turbulence hardly exists and is often replaced by
+hydromagnetic turbulence. Understanding the size of dissipative magnetic
+structures is important in estimating the time scale of Galactic scintillation
+and other observational and theoretical aspects of interstellar and
+intergalactic small-scale dynamos. Here we show that, during the kinematic
+phase of the small-scale dynamo, the cutoff wavenumber of the magnetic energy
+spectra scales as expected for large magnetic Prandtl numbers, but continues in
+the same way also for moderately small values - contrary to what is expected.
+For a critical magnetic Prandtl number of about 0.3, the dissipative and
+resistive cutoffs are found to occur at the same wavenumber. In the nonlinearly
+saturated regime, the critical magnetic Prandtl number becomes unity. The
+cutoff scale now has a shallower scaling with magnetic Prandtl number below a
+value of about three, and a steeper one otherwise compared to the kinematic
+regime.",2209.08717v2
+2022-12-22,Magnetic braking with MESA evolutionary models in the single star and LMXB regimes,"Magnetic braking has a prominent role in driving the evolution of close low
+mass binary systems and heavily influences the rotation rates of low mass F-
+and later type stars with convective envelopes. Several possible prescriptions
+that describe magnetic braking in the context of 1D stellar evolution models
+currently exist. We test four magnetic braking prescriptions against both low
+mass X-ray binary orbital periods from the Milky Way and single star rotation
+periods observed in open clusters. We find that data favors a magnetic braking
+prescription that follows a rapid transition from fast to slow rotation rates,
+exhibits saturated (inefficient) magnetic braking below a critical Rossby
+number, and that is sufficiently strong to reproduce ultra compact X-ray binary
+systems. Of the four prescriptions tested, these conditions are satisfied by a
+braking prescription that incorporates the effect of high order magnetic field
+topology on angular momentum loss. None of the braking prescriptions tested are
+able to replicate the stalled spin down observed in open cluster stars aged 700
+- 1000 Myr or so, with masses $\lesssim$ 0.8 $\rm M_{\odot}$.",2212.12037v3
+2024-01-31,Tailoring magnetic and hyperthermia properties of biphase iron oxide nanocubes through post-annealing,"Tailoring the magnetic properties of iron oxide nanosystems is essential to
+expand their biomedical applications. In this study, the 34 nm iron oxide
+nanocubes with two phases consisting of Fe3O4 and alpha-Fe2O3 were annealed for
+2 hours in the presence of O2, N2, He, and Ar to tune the respective phase
+volume fractions and control the magnetic properties. X-ray diffraction and
+magnetic measurements were carried out post-treatment to evaluate the changes
+of the treated samples compared to the as-prepared, which showed an enhancement
+of the alpha-Fe2O3 phase in the samples annealed with O2, while the others
+indicated Fe3O4 enhancement. Furthermore, the latter samples indicated
+enhancements in the crystallinity and saturation magnetization while coercivity
+enhancement was most significant in the samples annealed with O2, resulting in
+the highest specific absorption rates (up to 1000 W/g) in all the applied
+fields of 800, 600, and 400 Oe in agar during magnetic hyperthermia
+measurements. The general enhancement in the specific absorption rate
+post-annealing underscores the importance of the annealing atmosphere in the
+enhancement of the magnetic and structural properties of nanostructures.",2401.18009v1
+2024-02-05,Comprehensive study of magnetic field evolution in relativistic jets based on 2D simulations,"We use two-dimensional particle-in-cell simulations to investigate the
+generation and evolution of the magnetic field associated with the propagation
+of a jet for various initial conditions. We demonstrate that, in general, the
+magnetic field is initially grown by the Weibel and Mushroom instabilities.
+However, the field is saturated by the Alfv'en current limit. For initially
+non-magnetized plasma, we show that the growth of the magnetic field is delayed
+when the matter density of the jet environment is lower, which are in agreement
+with simple analytical predictions. We show that the higher Lorentz factor
+($\gtrsim 2$) prevents rapid growth of the magnetic fields. When the initial
+field is troidal, the position of the magnetic filaments moves away from the
+jet as the field strength increases. The axial initial field helps the jet
+maintain its shape more effectively than the troidal initial field.",2402.02737v1
+2022-12-07,Electronic and magnetic phase diagrams of Kitaev quantum spin liquid candidate Na$_2$Co$_2$TeO$_6$,"The 3$d^7$ Co$^{2+}$-based insulating magnet \NCTO{} has recently been
+reported to have strong Kitaev interactions on a honeycomb lattice, and is thus
+being considered as a Kitaev quantum spin liquid candidate. However, due to the
+existence of other types of interactions, a spontaneous long-range magnetic
+order occurs. This order is suppressed by applied magnetic fields leading to a
+succession of phases and ultimately saturation of the magnetic moments. The
+precise phase diagram, the nature of the phases, and the possibility that one
+of the field-induced phases is a Kitaev quantum spin liquid phase are still a
+matter of debate. Here we measured an extensive set of physical properties to
+build the complete temperature-field phase diagrams to magnetic saturation at
+10 T for magnetic fields along the $a$- and $a^*$-axes, and a partial phase
+diagram up to 60 T along $c$. We probe the phases using magnetization, specific
+heat, magnetocaloric effect, magnetostriction, dielectric constant, and
+electric polarization, which is a symmetry-sensitive probe. With these
+measurements we identify all the previously incomplete phase boundaries and
+find new high-field phase boundaries. We find strong magnetoelectric coupling
+in the dielectric constant and moderate magnetostrictive coupling at several
+phase boundaries. Furthermore, we detect the symmetry of the magnetic order
+using electrical polarization measurements under magnetic fields. Based on our
+analysis, the absence of electric polarization under zero or finite magnetic
+field in any of the phases or after...",2212.03849v3
+2009-12-16,Rocking ratchet induced by pure magnetic potentials with broken reflection symmetry,"A ratchet effect (the rectification of an ac injected current) which is
+purely magnetic in origin has been observed in a superconducting-magnetic
+nanostructure hybrid. The hybrid consists of a superconducting Nb film in
+contact with an array of nanoscale magnetic triangles, circular rings or
+elliptical rings. The arrays were placed into well-defined remanent magnetic
+states by application of different magnetic field cycles. The stray fields from
+these remanent states provide a magnetic landscape which influences the motion
+of superconducting vortices. We examined both randomly varying landscapes from
+demagnetized samples, and ordered landscapes from samples at remanence after
+saturation in which the magnetic rings form parallel onion states containing
+two domain walls. The ratchet effect is absent if the rings are in the
+demagnetized state or if the vortices propagate parallel to the magnetic
+reflection symmetry axis (perpendicular to the magnetic domain walls) in the
+ordered onion state. On the other hand, when the vortices move perpendicular to
+the magnetic reflection symmetry axis in the ordered onion state (parallel to
+the domain walls) a clear ratchet effect is observed. This behavior differs
+qualitatively from that observed in samples containing arrays of triangular Ni
+nanostructures, which show a ratchet of structural origin.",0912.3193v1
+2015-11-14,Magnetic field induced augmented thermal conduction phenomenon in magneto nanocolloids,"Magnetic field induced drastically augmented thermal conductivity of magneto
+nanocolloids involving magnetic oxide nanoparticles, viz. Fe2O3, Fe3O4, Nickel
+oxide (NiO), Cobalt oxide (Co3O4), dispersed in different base fluids (heat
+transfer oil, kerosene, and ethylene glycol) have been reported. Experiments
+reveal the augmented thermal transport under the external applied magnetic
+field, with kerosene based MNCs showing at relatively low magnetic field
+intensities as compared to the heat transfer oil and EG based MNCs. A maximum
+thermal conductivity enhancement of 114 % is attained at 7.0 vol. %
+concentration and 0.1 T field intensity for Fe3O4/EG magneto nanocolloid.
+However, a maximum of 82% thermal conductivity enhancement is observed for
+Fe3O4/Kerosene magneto nanocolloid for the same concentration but relatively at
+low magnetic field (600 G). Thereby, a strong effect of fluid as well as
+particle physical properties on the chain formation propensity, leading to
+enhanced conduction, in such systems is observed. Co3O4 nanoparticles show
+insignificant effect on the thermal conductivity enhancement of MNCs due to
+their minimal magnetic moment. An analytical approach has been proposed to
+understand the mechanism and physics behind the thermal conductivity
+enhancement under external applied magnetic field, in tune with near field
+magnetostatic interactions as well as Neel relaxivity of the magnetic
+nanoparticles. Furthermore, the analytical model is able to predict the
+phenomenon of enhanced thermal conductivity as a function of physical
+parameters such as chain length, size and types of nanoparticles, fluid
+characteristics, magnetic field intensity, saturation magnetic moment,
+nanoparticle concentration etc. and good agreement with the experimental
+results has been observed.",1511.04560v1
+2015-12-23,Magnetic Ordering and Crystal Field Effects in Quasi Caged Structure Compound PrFe$_2$Al$_8$,"The compound PrFe$_2$Al$_8$ possesses a three-dimensional network structure
+resulting from the packing of Al polyhedra centered at the transition metal
+element Fe and the rare earth Pr. Along the $c$-axis, Fe and Pr form {\em
+chains} which are separated from each other by the Al-network. In this paper,
+the magnetism and crystalline electric field effects in PrFe$_2$Al$_8$ are
+investigated through the analysis of magnetization and specific heat data. A
+magnetic phase transition in the Pr lattice is identified at
+$T^{Pr}_{N}\approx$ 4~K in dc magnetization and ac susceptibility data. At 2~K,
+the magnetization isotherm presents a ferromagnetic saturation, however,
+failing to reach full spin-only ferromagnetic moment of Pr$^{3+}$. Metamagnetic
+step-like low-field features are present in the magnetization curve at 2~K
+which is shown to shift upon field-cooling the material. Arrott plots centered
+around $T^{Pr}_{N}$ display ""S""-like features suggestive of an inhomogeneous
+magnetic state. The magnetic entropy, $S_m$, estimated from specific heat
+outputs a value of $R$ ln(2) at $T_{N2}$ suggesting a doublet state for
+Pr$^{3+}$. The magnetic specific heat is modeled by using a 9-level Schottky
+equation pertinent to the Pr$^{3+}$ ion with $J$ = 4. Given the crystalline
+electric field situation of Pr$^{3+}$, the inference of a doublet state from
+specific heat and consequent long-range magnetic order is an unexpected result.",1512.07488v1
+2018-06-02,Mechanically Induced Thermal Breakdown in Magnetic Shuttle Structures,"A theory of a thermally induced single-electron ""shuttling"" instability in a
+magnetic nanomechanical device subject to an external magnetic field is
+presented in the Coulomb blockade regime of electron transport. The model
+magnetic shuttle device considered comprises a movable metallic grain suspended
+between two magnetic leads, which are kept at different temperatures and
+assumed to be fully spin polarized with antiparallel magnetizations. For a
+given temperature difference shuttling is found to occur for a region of
+external magnetic fields between a lower and an upper critical field strength,
+which separate the shuttling regime from normal small-amplitude ""vibronic""
+regimes. We find that (i) the upper critical magnetic field saturates to a
+constant value in the high temperature limit and that the shuttle instability
+domain expands with a decrease of the temperature, (ii) the lower critical
+magnetic field depends not only on the temperature independent phenomenological
+friction coefficient used in the model but also on intrinsic friction (which
+vanishes in the high temperature limit) caused by magnetic exchange forces and
+electron tunneling between the quantum dot and the leads. The feasibility of
+using thermally driven magnetic shuttle systems to harvest thermal breakdown
+phenomena is discussed.",1806.00633v1
+2018-06-08,Real-Space Magnetic Imaging of the Multiferroic Spinels MnV2O4 and Mn3O4,"Controlling multiferroic behavior in materials will enable the development of
+a wide variety of technological applications. However, the exact mechanisms
+driving multiferroic behavior are not well understood in most materials. Two
+such materials are the spinels MnV2O4 and Mn3O4, where mechanical strain is
+thought to play a role in determining magnetic behavior. Bulk studies of MnV2O4
+have yielded conflicting and inconclusive results, due in part to the presence
+of mesoscale magnetic inhomogeneity, which complicates the interpretation of
+bulk measurements. To study the sub-micron-scale magnetic properties of
+Mn-based spinel materials, we performed magnetic force microscopy (MFM) on
+MnV2O4 samples subject to different levels of mechanical strain. We also used a
+crystal grain mapping technique to perform spatially registered MFM on Mn3O4.
+These local investigations revealed 100-nm-scale ""stripe"" modulations in the
+magnetic structure of both materials. In MnV2O4, the magnetization of these
+stripes is estimated to be Mz $\approx$ 105 A/m, which is on the order of the
+saturation magnetization reported previously. Cooling in a strong magnetic
+field eliminated the stripe patterning only in the low-strain sample of MnV2O4.
+The discovery of nanoscale magnetostructural inhomogeneity that is highly
+susceptible to magnetic field control in these materials necessitates both a
+revision of theoretical proposals and a reinterpretation of experimental data
+regarding the low-temperature phases and magnetic-field-tunable properties of
+these Mn-based spinels.",1806.03148v1
+2019-03-02,Microwave excitations and hysteretic magnetization dynamics of stripe domain films,"FeNi films with the stripe domain (SD) pattern are prepared by
+electrodeposition and sputtering methods. The magnetic domain, static magnetic
+parameters, and quality factor, as well as dynamic properties of the two films,
+are respectively performed. The results show the magnetizations of the film
+were dependent on the direction of SD, and the rotation of the SD is lagging
+behind the magnetization reversal. The microwave properties of the SD emerge
+dynamic hysteresis before the saturation magnetic field. These microwave
+properties are selectively excited with acoustic mode, optical mode, and
+spin-wave mode. The frequency and intensity of different resonance modes of
+stripe domain are determined by the local magnetization. The magnetization
+variations and the rotation of SD of different modes are further illuminated by
+the micromagnetic simulation. The magnetic anisotropy and the resonance
+intensity of permeability of different modes were finally described by the
+modified resonance equations.",1903.00656v2
+2019-04-09,On the origin of the magnetic energy in the quiet solar chromosphere,"The presence of magnetic field is crucial in the transport of energy through
+the solar atmosphere. Recent ground-based and space-borne observations of the
+quiet Sun have revealed that magnetic field accumulates at photospheric
+heights, via a local dynamo or from small-scale flux emergence events. However,
+most of this small-scale magnetic field may not expand into the chromosphere
+due to the entropy drop with height at the photosphere. Here we present a study
+that uses a high resolution 3D radiative MHD simulation of the solar atmosphere
+with non-grey and non-LTE radiative transfer and thermal conduction along the
+magnetic field to reveal that: 1) the net magnetic flux from the simulated
+quiet photosphere is not sufficient to maintain a chromospheric magnetic field
+(on average), 2) processes in the lower chromosphere, in the region dominated
+by magneto-acoustic shocks, are able to convert kinetic energy into magnetic
+energy, 3) the magnetic energy in the chromosphere increases linearly in time
+until the r.m.s. of the magnetic field strength saturates at roughly 4 to 30 G
+(horizontal average) due to conversion from kinetic energy, 4) and that the
+magnetic features formed in the chromosphere are localized to this region.",1904.04464v2
+2019-05-31,Magnetic Anisotropy and Low Field Magnetic Phase Diagram of Quasi Two-Dimensional Ferromagnet Cr$_2$Ge$_2$Te$_6$,"In this work we present a comprehensive investigation on magnetic and
+thermodynamic properties of the two-dimensional layered honeycomb system
+Cr$_2$Ge$_2$Te$_6$. Using magnetization and specific heat measurements under
+magnetic field applied along two crystallographic directions we obtain the
+magnetic phase diagram for both directions. Cr$_2$Ge$_2$Te$_6$ is a ferromagnet
+with a Curie temperature $T_C=65$ K and exhibits an easy magnetization axis
+perpendicular to the structural layers in the $ab$-plane. Under magnetic fields
+applied parallel to the hard plane $ab$ below the magnetic saturation, a
+downturn with an onset temperature $T\textrm{*}$ is observed in the temperature
+dependent magnetization curve. $T\textrm{*}$ shows a monotonous shift towards
+lower temperatures with increasing field. The nature of this anisotropic and
+specific behavior for fields in the hard plane is discussed as an interplay
+among field, temperature and effective magnetic anisotropy. Similarities to
+structurally related compounds such as CrX$_3$ (X = Br, I) hint towards a
+universality of this behavior in ferromagnetic quasi two-dimensional honeycomb
+materials.",1905.13609v2
+2019-07-04,Micromagnetic modelling of magnetic domain walls and domains in cylindrical nanowires,"Magnetic cylindrical nanowires are very fascinating objects where the curved
+geometry allows many novel magnetic effects and a variety of non-trivial
+magnetic structures. Micromagnetic modelling plays an important role in
+revealing the magnetization distribution in magnetic nanowires, often not
+accessible by imaging methods with sufficient details. Here we review the
+magnetic properties of the shape anisotropy-dominated nanowires and the
+nanowires with competing shape and magnetocrystalline anisotropies, as revealed
+by micromagnetic modelling. We discuss the variety of magnetic walls and
+magnetic domains reported by micromagnetic simulations in cylindrical
+nanowires. The most known domain walls types are the transverse and vortex
+(Bloch point) domain walls and the transition between them is materials and
+nanowire diameter dependent. Importantly, the field or current-driven domain
+walls in cylindrical nanowires can achieve very high velocities. In recent
+simulations of nanowires with larger diameter the skyrmion tubes are also
+reported. In nanowires with large saturation magnetization the core of these
+tubes may form a helicoidal ('corkscrew') structure. The topology of the
+skyrmion tubes play an important role in the pinning mechanism, discussed here
+on the example of FeCo modulated nanowires. Other discussed examples include
+the influence of antinotches ('bamboo' nanowires) on the remanent magnetization
+configurations for hcp Co and FeCo nanowires and Co-Ni multisegmented
+nanowires.",1907.02318v1
+2019-08-28,Non-monotonic response of a sheared magnetic liquid crystal to an external field,"Utilizing molecular dynamics simulations, we report a non-monotonic
+dependence of the shear stress on the strength of an external magnetic field
+($H$) in a liquid-crystalline mixture of magnetic and non-magnetic anisotropic
+particles. This non-monotonic behavior is in sharp contrast with the
+well-studied monotonic $H$-dependency of the shear stress in conventional
+ferrofluids, where the shear stress increases with $H$ until it reaches a
+saturation value. We relate the origin of this non-monotonicity to the
+competing effects of particle alignment along the shear-induced direction, on
+the one hand, and the magnetic field direction, on the other hand. To isolate
+the role of these competing effects, we consider a two-component mixture
+composed of particles with effectively identical steric interactions, where the
+orientations of a small fraction, i.e.\ the magnetic ones, are coupled to the
+external magnetic field. By increasing $H$ from zero, the orientations of the
+magnetic particles show a Fr\'{e}ederickz-like transition and eventually start
+deviating from the shear-induced orientation, leading to an increase in shear
+stress. Upon further increase of $H$, a demixing of the magnetic particles from
+the non-magnetic ones occurs which leads to a drop in shear stress, hence
+creating a non-monotonic response to $H$. Unlike the equilibrium demixing
+phenomena reported in previous studies, the demixing observed here is neither
+due to size-polydispersity nor due to a wall-induced nematic transition. Based
+on a simplified Onsager analysis, we rather argue that it occurs solely due to
+packing entropy of particles with different shear- or magnetic-field-induced
+orientations.",1908.10815v1
+2019-12-10,Magnetic properties of thin epitaxial Pd$_{1-x}$Fe$_x$ alloy films,"In the paper we present the results of extensive studies of palladium-rich
+Pd1-xFex alloy films epitaxially grown on MgO single-crystal substrate. In a
+composition range of x = 0.01-0.07 these materials are soft ferromagnets, the
+saturation magnetization and magnetic anisotropy of which can be tuned by its
+composition. Vibrating sample magnetometry was used to study temperature
+dependences of spontaneous magnetic moment and to establish the temperature of
+magnetic ordering (Curie temperature). Ferromagnetic resonance (FMR)
+measurements at low temperatures in the in-plane and out-of-plane geometries
+revealed the four-fold in-plane magnetic anisotropy with the easy directions
+along the <110> axes of the substrate. The modelling of the angular dependence
+of the field for resonance allowed to extract the cubic and tetragonal
+contributions to the magnetic anisotropy of the films and establish their
+dependence on the concentration of iron in the alloy. Experimental data are
+discussed in the framework of existing theories of dilute magnetic alloys.
+Using the anisotropy constants established from FMR, the magnetic hysteresis
+loops are reproduced utilizing the Stoner-Wohlfarth model thus indicating the
+predominant coherent magnetic moment rotation at low temperatures. The obtained
+results compile a database of magnetic properties of a palladium-iron alloy
+considered as a material for superconducting spintronics.",1912.04852v1
+2020-04-15,Synthesis optimization of Zn-Mn ferrites for magnetic fluid aplications,"Mn-Zn ferrite nanoparticles have been subject of increasing research due to
+their desired properties for a wide range of applications. These properties
+include nanometer particle size control, tunable magnetic properties and low
+toxicity, providing these ferrites with the necessary requirements for cancer
+treatment via magnetic hyperthermia. During this master thesis, powders of
+Mn1-xZnxFe2O4 (x=0; 0.5; 0.8; 1) were synthesized via the sol-gel
+autocombustion and hydrothermal methods, aiming to optimize their structural
+and magnetic properties for further application in a ferrofluid. Samples were
+characterized by XRD, SQUID, SEM, TEM and magnetic induction heating (MIH)
+techniques. The XRD diffractograms of hydrothermally produced samples present
+spinel crystal structure with high single-phase percentage (>88%). Rietveld
+refinement and Williamson-Hall analysis reveal a decrease of lattice constant
+and crystallite size with increase of Zn/Mn ratio. TEM images reveal narrow
+particle size distributions and decrease of the mean particle size with
+increase of Zn/Mn. SQUID results show that the increase of Zn results in a
+decrease of saturation magnetization and remnant magnetization. More
+noticeably, the M(T) curves present a shift in the samples magnetic ordering
+temperature towards lower temperatures with the increase of Zn content, from
+~556 to ~284 K. The MIH experiment also unveil a decrease in the heating rate
+with the increase of Zn. Nanocrystals of Mn-Zn ferrite produced by hydrothermal
+method present better crystallinity and magnetic properties than the sol-gel
+auto-combustion samples. The hydrothermally synthesized samples revealed
+dependence of its structural and magnetic properties with Mn/Zn ratio.The
+magnetic ordering temperature of these ferrites can be used as a
+self-controlled mechanism of heating, raising these ferrites to a class of
+smart materials.",2004.07006v2
+2021-04-08,Tailoring magnetization reversal of a single-domain bar nanomagnet via its end geometry,"Nanoscale single-domain bar magnets are building blocks for a variety of
+fundamental and applied mesoscopic magnetic systems, such as artificial spin
+ices, magnetic shape-morphing microbots as well as magnetic majority logic
+gates. The magnetization reversal switching field of the bar nanomagnets is a
+crucial parameter that determines the physical properties and functionalities
+of their constituted artificial systems. Previous methods on tuning the
+magnetization reversal switching field of a bar nanomagnet usually rely on
+modifying its aspect ratio, such as its length, width and/or thickness. Here,
+we show that the switching field of a bar nanomagnet saturates when extending
+its length beyond a certain value, preventing further tailoring of the
+magnetization reversal via aspect ratios. We showcase highly tunable switching
+field of a bar nanomagent by tailoring its end geometry without altering its
+size. This provides an easy method to control the magnetization reversal of a
+single-domain bar nanomagnet. It would enable new research and/or applications,
+such as designing artificial spin ices with additional tuning parameters,
+engineering magnetic microbots with more flexibility as well as developing
+magnetic quantum-dot cellular automata systems for low power computing.",2104.03517v1
+2021-08-05,Metamagnetic Transitions in Few-Layer CrOCl Controlled by Magnetic Anisotropy Flipping,"The pivotal role of magnetic anisotropy in stabilising two-dimensional (2D)
+magnetism has been widely accepted, however, direct correlation between
+magnetic anisotropy and long-range magnetic ordering in the 2D limit is yet to
+be explored. Here, using angle- and temperature-dependent tunnelling
+magnetoresistance, we report unprecedented metamagnetic phase transitions in
+atomically-thin CrOCl, triggered by magnetic easy-axis flipping instead of the
+conventional spin flop mechanism. Few-layer CrOCl tunnelling devices of various
+thicknesses consistently show an in-plane antiferromagnetic (AFM) ground state
+with the easy axis aligned along the Cr-O-Cr direction (b-axis). Strikingly,
+with the presence of a magnetic field perpendicular to the easy-axis (H||c),
+magnetization of CrOCl does not follow the prevalent spin rotation and
+saturation pattern, but rather exhibits an easy-axis flipping from the in-plane
+to out-of-plane directions. Such magnetic anisotropy controlled metamagnetic
+phase transitions are manifested by a drastic upturn in tun- nelling current,
+which shows anomalous shifts towards higher H when temperature increases. By 2D
+mapping of tunnelling currents as a function of both temperature and H, we
+determine a unique ferrimagnetic state with a superstructure periodicity of
+five unit cells after the field-induced metam- agnetic transitions. The
+feasibility to control 2D magnetism by manipulating magnetic anisotropy may
+open enormous opportunities in spin-based device applications.",2108.02825v1
+2021-10-05,Thermal transport of the frustrated spin-chain mineral linarite: Magnetic heat transport and strong spin-phonon scattering,"The mineral linarite (PbCuSO$_4$(OH)$_2$) forms a monoclinic structure where
+a sequence of Cu(OH)$_2$ units forms a spin-$\frac{1}{2}$ chain. Competing
+ferromagnetic nearest-neighbor ($J_1$) and antiferromagnetic
+next-nearest-neighbor interactions ($J_2$) in this quasi-one-dimensional spin
+structure imply magnetic frustration and lead to magnetic ordering below $T_N
+=$2.8 K in a mutliferroic elliptical spin-spiral ground state. Upon the
+application of a magnetic field along the spin-chain direction, distinct
+magnetically ordered phases can be induced. We studied the thermal conductivity
+$\kappa$ in this material across the magnetic phase diagram as well as in the
+paramagnetic regime in the temperature ranges 0.07-1 K and 9-300 K. We found
+that in linarite the heat is carried mainly by phonons but shows a peculiar
+non-monotonic behavior in field. In particular, $\kappa$ is highly suppressed
+at the magnetic phase boundaries, indicative of strong scattering of the
+phonons off critical magnetic fluctuations. Even at temperatures far above the
+magnetically ordered phases, the phononic thermal conductivity is reduced due
+to scattering off magnetic fluctuations. The mean free path due to spin-phonon
+scattering ($l_{\text{spin-phonon}}$) was determined as function of
+temperature. A power law behavior was observed mainly above 0.5 K indicating
+the thermal activation of spin fluctuations. In the critical regime close to
+the saturation field, $l_{\text{spin-phonon}}$ shows a $1/T$ dependence.
+Furthermore, a magnon thermal transport channel was verified in the helical
+magnetic phase. We estimate a magnon mean free path which corresponds to about
+1000 lattice spacings.",2110.01865v1
+2021-10-21,Shaping Magnetic Fields with Zero-Magnetic-Permeability Media,"Some of the most important technological challenges of today's society, such
+as fusion reactors for future clean unlimited energy or the next generation of
+medical imaging techniques, require precise spatial shapes of strong magnetic
+fields. Achieving these high fields is currently hindered by limitations such
+as large forces damaging the wires in coils or the saturation of ferromagnets
+at high fields. Here we demonstrate a novel paradigm for creating magnetic
+landscapes. By enclosing magnetic sources within zero-magnetic-permeability
+(ZMP) media, a set of novel properties is unveiled. The magnetic field shape
+directly results from the contour of the outer surface of the ZMP enclosure,
+which allows the realization of basically any imaginable field landscape. Also,
+currents embedded in ZMP media can be fully magnetically isolated, which
+eliminates the forces in the wires, one of the main factors that currently
+impedes achieving very high magnetic fields. We confirm these properties,
+rooted in fundamental laws of electromagnetism, by numerical simulations and by
+proof-of-principle experiments using conventional high-temperature
+superconductors as ZMP materials, which showcase the practical applicability of
+our ideas. The freedom in the design of magnetic fields provided by ZMP media
+enables to concentrate and homogenize magnetic fields with unprecedented
+precision, as needed in medical imaging techniques and particle-physics
+experiments, and to realize devices like perfect electromagnetic absorbers of
+mechanical vibrations.",2110.11257v1
+2022-07-15,Controlling polarization of spintronic THz emitter by remanent magnetization texture,"Terahertz (THz) sciences and technologies have contributed to a rapid
+development of a wide range of applications and expanded the frontiers in
+fundamental science. Spintronic terahertz emitters offer conceptual advantages
+since the spin orientation in the magnetic layer can be easily controlled
+either by the externally applied magnetic field or by the internal magnetic
+field distribution determined by the specific shape of the magnetic elements.
+Here, we report a switchable terahertz source based on micropatterned magnetic
+heterostructures driven by femtosecond laser pulses. We show that the precise
+tunability of the polarization state is facilitated by the underlying
+magnetization texture of the magnetic layer that is dictated by the shape of
+the microstructure. These results also reveal the underlying physical
+mechanisms of a nonuniform magnetization state on the generation of ultrafast
+spin currents in the magnetic heterostructures. Our findings indicate that the
+emission of the linearly polarized THz waves can be switched on and off by
+saturating the sample using a biasing magnetic field, opening fascinating
+perspectives for integrated on-chip THz devices with wide-ranging potential
+applications.",2207.07707v1
+2023-06-19,Transition between radial and toroidal orders in a trimer-based magnetic metasurface,"The change in the arrangement of magnetic dipole moments in a magnetic
+metasurface, due to the influence of an external static magnetic field, is
+discussed. Each meta-atom of the metasurface is composed of three identical
+disk-shaped resonators (trimer) made of magnetically saturated ferrite. To
+provide physical insight, full-wave numerical simulations of the near-fields
+and transmission characteristics of the metasurface are complemented by the
+theoretical description based on the multipole decomposition method. With these
+methods, the study of eigenmodes and scattering conditions of a single magnetic
+resonator, trimer, and their array forming the metasurface is performed. It is
+found that the magnetic dipole-based collective hybrid mode of the trimer can
+be gradually transformed from the radial (pseudomonopole) to azimuthal
+(toroidal) order and vice versa by varying the bias magnetic field strength.
+This is because the magnetic dipole moment of each individual disk constituting
+the trimer undergoes rotation as the bias magnetic field strength changes. This
+transition between two orders is accompanied by various patterns of
+localization of the electric field inside the meta-atoms. Due to the unique
+field configuration of these modes, the proposed metasurface can be considered
+for designing magnetic field sensors and nonreciprocal devices.",2306.10776v2
+2016-10-27,Magnetic activity in the HARPS M-dwarf sample. The rotation-activity relationship for very low-mass stars through R'HK,"Atmospheric magnetic fields in stars with convective envelopes heat stellar
+chromospheres. Starting with the historical Mount Wilson monitoring program,
+CaH&K lines have been widely used to trace stellar magnetic activity, and as a
+proxy for rotation period and consequently for stellar age. Monitoring stellar
+activity has also become essential in filtering out false-positives due to
+magnetic activity in extra-solar planet surveys. The Ca H&Kemission is
+traditionally quantified through the R'HK-index, which compares the
+chromospheric flux in the doublet to the overall bolometric flux of the star.
+Much work has been done to characterize this index for FGK-dwarfs, but M-dwarfs
+were left out of these analyses and no calibration of their Ca ii H&K emission
+to an R'HK exists to date. We set out to characterize the magnetic activity of
+the low and very low-mass stars by providing a calibration of the R'HK-index
+that extends to the realm of M-dwarfs, and by evaluating the relation between
+R'HK and the rotation period. We calibrated the bolometric and photospheric
+factors for M-dwarfs to properly transform the S-index into the R'HK. We
+monitored magnetic activity through the Ca ii H&K emission lines in the HARPS
+M-dwarf sample. The R'HK index, like the fractional X-ray luminosity L_X/Lbol,
+shows a saturated correlation with rotation, with saturation setting in around
+a ten days rotation period. Above that period, slower rotators show weaker Ca
+ii activity, as expected. Under that period, the R'HK index saturates to
+~10^-4. Stellar mass modulates the Ca ii activity, with R'HK showing a constant
+basal activity above 0.6Msun and then decreasing with mass between 0.6Msun and
+the fully-convective limit of 0.35Msun. Short-term variability of the activity
+correlates with its mean level, stars with higher R'HK index show larger R'HK
+variability, as previously observed for earlier spectral types.",1610.09007v2
+2023-04-14,Effect of magnetic fields on the dynamics and gravitational wave emission of PPI-saturated self-gravitating accretion disks: simulations in full GR,"We explore the effect magnetic fields have on self-gravitating accretion
+disks around spinning black holes via numerical evolutions in full dynamical
+magnetohydrodynamic spacetimes. The configurations we study are unstable to the
+Papaloizou-Pringle Instability (PPI). PPI-saturated accretion tori have been
+shown to produce gravitational waves, detectable to cosmological distances by
+third-generation gravitational wave (GW) observatories. While the PPI operates
+strongly for purely hydrodynamic disks, the situation can be different for
+disks hosting initially small magnetic fields. Evolutions of disks without
+self-gravity in fixed BH spacetimes have shown that small seed fields can
+initiate the rapid growth of the magneto-rotational instability (MRI), which
+then strongly suppresses the PPI. Since realistic astrophysical disks are
+expected to be magnetized, PPI-generated GW signals may be suppressed as well.
+However, it is unclear what happens when the disk self-gravity is restored.
+Here, we study the impact of magnetic fields on the PPI-saturated state of a
+self-gravitating accretion disk around a spinning BH ($\chi = 0.7$) aligned
+with the disk angular momentum, as well as one around a non-spinning BH. We
+find the MRI is effective at reducing the amplitude of PPI modes and their
+associated GWs, but the systems still generate GWs. Estimating the
+detectability of these systems accross a wide range of masses, we show that
+magnetic fields reduce the maximum detection distance by Cosmic Explorer from
+300Mpc (in the pure hydrodynamic case) to 45Mpc for a $10 M_{\odot}$ system, by
+LISA from 11500Mpc to 2700Mpc for a $2 \times 10^{5} M_{\odot}$ system, and by
+DECIGO from $z \approx 5$ down to $z \approx 2$ for a $1000 M_{\odot}$ system.",2304.07282v2
+2002-10-29,Evidence for the formation of magnetic moments in the cuprate superconductor Hg$_{0.8}$Cu$_{0.2}$Ba$_2$Ca$_2$Cu$_3$O$_{8+δ}$ below $T_c$ seen by NQR,"We report pure zero field nuclear magnetic resonance (NQR) measurements on
+the optimally doped three layer high-$ T_{c} $-compounds HgBaCaCuO and
+HgBaCaCuO(F) with $T_c$ 134 K. Above $ T_{c}$ two Cu NQR line pairs are
+observed in the spectra corresponding to the two inequivalent Cu lattice sites.
+Below $ T_{c}$ the Cu NQR spectra show additional lines leading to the extreme
+broadened Cu NQR spectra at 4.2 K well known for the HgBaCaCuO compounds. The
+spin-lattice relaxation curves follow a triple exponential function with
+coefficients depend onto the saturation time (number of saturation pulses),
+whereas the spin-spin relaxation curve is described by a single exponential
+function. From the spin-lattice relaxation we deduced a complete removal of the
+Kramers degeneracy of the Cu quadrupole indicating that the additional lines
+are due to a Zeemann splitting of the $^{63/65}$Cu lines due to the spontaneous
+formation of magnetic moments within the CuO layers. Below 140 K, the spectra
+are well fitted by a number of 6 $^{63/65}$Cu line pairs. From the number of
+the Cu lines, the position of the lines relative to each other and the complete
+removal of the Kramers degeneracy we deduced an orientation of the magnetic
+moments parallel to the symmetry axis of the electric field gradient tensor
+with magnitudes of the order of 1000 G. We also discuss the possible
+microscopic origin of the observed internal magnetic fields.",0210652v2
+2006-12-27,"Peculiarities of the transport properties of InMnAs layers, produced by the laser deposition, in strong magnetic fields","Magnetotransport properties of p-InMnAs layers are studied in pulsed magnetic
+fields up to 30 T. Samples were prepared by the laser deposition and annealed
+by ruby laser pulses. Well annealed samples show p-type conductivity while they
+were n-type before the annealing. Surprisingly the anomalous Hall effect
+resistance in paramagnetic state (T>40 K) and in strong magnetic fields (B > 20
+T) appears to be greater than that in ferromagnetic state (T <= 40 K), while
+the longitudinal resistance rises with the temperature decrease. The negative
+magnetoresistance saturates in magnetic fields higher then 10T at T near 4 K
+only, whereas the saturation fields of the anomalous Hall effect resistance are
+much less (around 2 T at 30K). The total reduction of resistance exceeds 10
+times in magnetic fields around of 10T. The obtained results are interpreted on
+the base of the assumptions of the non-uniform distribution of Mn atoms acting
+as acceptors, the local ferromagnetic transition and the percolation-like
+character of the film conductivity, which prevailed under conditions of the
+strong fluctuations of the exchange interaction. Characteristic scales of the
+magneto-electric nonuniformity are estimated using analysis of the mesoscopic
+fluctuations of the non-diagonal components of the magnetoresistivity tensor.",0612641v1
+2007-12-19,Nonlinear Simulations of the Heat Flux Driven Buoyancy Instability and its Implications for Galaxy Clusters,"In low collisionality plasmas heat flows almost exclusively along magnetic
+field lines, and the condition for stability to convection is modified from the
+standard Schwarzschild criterion. We present local two and three-dimensional
+simulations of a new heat flux driven buoyancy instability (the HBI) that
+occurs when the temperature in a plasma decreases in the direction of gravity.
+We find that the HBI drives a convective dynamo that amplifies an initially
+weak magnetic field by a factor of ~20. In simulations that begin with the
+magnetic field aligned with the temperature gradient, the HBI saturates by
+rearranging the magnetic field lines to be almost purely perpendicular to the
+initial temperature gradient. This magnetic field reorientation results in a
+net heat flux through the plasma that is less than 1% of the field-free
+(Spitzer) value. We show that the HBI is likely to be present in the cool cores
+of clusters of galaxies between ~0.1-100 kpc, where the temperature increases
+outwards. The saturated state of the HBI suggests that inward thermal
+conduction from large radii in clusters is unlikely to solve the cooling flow
+problem. Finally, we also suggest that the HBI may contribute to suppressing
+conduction across cold fronts in galaxy clusters.",0712.3048v1
+2012-10-01,Unconventional quantum ordered and disordered states in the highly frustrated spin-1/2 Ising-Heisenberg model on triangles-in-triangles lattices,"Ground state and thermodynamics of geometrically frustrated spin-1/2
+Ising-Heisenberg model on two different but topologically related
+triangles-in-triangles lattices is investigated in particular. A rigorous
+mapping based on generalized star-triangle transformations enables one to
+derive exact analytical results for the free and internal energy, spontaneous
+magnetization, entropy and specific heat from the known exact results for the
+corresponding spin-1/2 Ising model on a triangular lattice. It is demonstrated
+that several unconventional quantum ordered and disordered phases may become
+the ground state in addition to the classical ferromagnetic phase with a
+perfect alignment of all constituent spins. A mutual competition between the
+ferromagnetic Ising and XXZ Heisenberg interactions may lead to an appearance
+of a peculiar quantum ferromagnetic phase, in which the magnetic moment of the
+Heisenberg spins undergoes a quantum reduction to one third of the saturation
+value in contrast with the fully saturated magnetic moment of the classical
+Ising spins. In the highly frustrated regime, we have found either the
+disordered quantum paramagnetic phase with the substantial residual entropy or
+a similar but strikingly spontaneously long-range ordered phase, in which a
+quantum reduction of the magnetic moment of the Heisenberg spins causes a small
+quantum reduction of the magnetic moment of otherwise purely classical Ising
+spins. It is evidenced that the specific heat exhibits diverse thermal
+dependences with or without a logarithmic divergence superimposed either on one
+or two round Schottky-type maxima.",1210.0337v3
+2013-05-15,"Structural ordering driven anisotropic magnetoresistance, anomalous Hall resistance and its topological overtones in full-Heusler Co2MnSi thin films","We report the evolution of crystallographic structure, magnetic ordering and
+electronic transport in thin films of full-Heusler alloy Co$_2$MnSi deposited
+on (001) MgO with annealing temperatures ($T_A$). By increasing the $T_A$ from
+300$^\circ$C to 600$^\circ$C, the film goes from a disordered nanocrystalline
+phase to $B2$ ordered and finally to the $L2_1$ ordered alloy. The saturation
+magnetic moment improves with structural ordering and approaches the
+Slater-Pauling value of $\approx 5.0 \mu_B$ per formula unit for $T_A$ =
+600$^\circ$C. At this stage the films are soft magnets with coercive and
+saturation fields as low as $\approx$ 7 mT and 350 mT, respectively. Remarkable
+effects of improved structural order are also seen in longitudinal resistivity
+($\rho_{xx}$) and residual resistivity ratio. A model based upon electronic
+transparency of grain boundaries illucidates the transition from a state of
+negative $d\rho/dT$ to positive $d\rho/dT$ with improved structural order. The
+Hall resistivity ($\rho_{xy}$) derives contribution from the normal scattering
+of charge carriers in external magnetic field, the anomalous effect originating
+from built-in magnetization and a small but distinct topological Hall effect in
+the disordered phase. The carrier concentration ($n$) and mobility ($\mu$) have
+been extracted from the high field $\rho_{xy}$ data. The highly ordered films
+are characterized by $n$ and $\mu$ of 1.19$\times$ 10$^{29}$ m$^{-3}$ and 0.4
+cm$^2V^{-1}s^{-1}$ at room temperature. The dependence of $\rho_{xy}$ on
+$\rho_{xx}$ indicates the dominance of skew scattering in our films, which
+shows a monotonic drop on raising the $T_A$. The topological Hall effect is
+analyzed for the films annealed at 300$^\circ$C. ......",1305.3453v1
+2016-11-29,Critical quench dynamics of random quantum spin chains: Ultra-slow relaxation from initial order and delayed ordering from initial disorder,"By means of free fermionic techniques combined with multiple precision
+arithmetic we study the time evolution of the average magnetization,
+$\overline{m}(t)$, of the random transverse-field Ising chain after global
+quenches. We observe different relaxation behaviors for quenches starting from
+different initial states to the critical point. Starting from a fully ordered
+initial state, the relaxation is logarithmically slow described by
+$\overline{m}(t) \sim \ln^a t$, and in a finite sample of length $L$ the
+average magnetization saturates at a size-dependent plateau $\overline{m}_p(L)
+\sim L^{-b}$; here the two exponents satisfy the relation $b/a=\psi=1/2$.
+Starting from a fully disordered initial state, the magnetization stays at zero
+for a period of time until $t=t_d$ with $\ln t_d \sim L^{\psi}$ and then starts
+to increase until it saturates to an asymptotic value $\overline{m}_p(L) \sim
+L^{-b'}$, with $b'\approx 1.5$. For both quenching protocols, finite-size
+scaling is satisfied in terms of the scaled variable $\ln t/L^{\psi}$.
+Furthermore, the distribution of long-time limiting values of the magnetization
+shows that the typical and the average values scale differently and the average
+is governed by rare events. The non-equilibrium dynamical behavior of the
+magnetization is explained through semi-classical theory.",1611.09495v2
+2018-09-22,Large magnetic thermal conductivity induced by frustration in low-dimensional quantum magnets,"We study the magnetic field-dependence of the thermal conductivity due to
+magnetic excitations in frustrated spin-1/2 Heisenberg chains. Near the
+saturation field, the system is described by a dilute gas of weakly-interacting
+fermions (free-fermion fixed point). We show that in this regime the thermal
+conductivity exhibits a non-monotonic behavior as a function of the ratio
+$\alpha= J_2/J_1$ between second and first nearest-neighbor antiferromagnetic
+exchange interactions. This result is a direct consequence of the splitting of
+the single-particle dispersion minimum into two minima that takes place at the
+Lifshitz point $\alpha=1/4$. Upon increasing $\alpha$ from zero, the inverse
+mass vanishes at $\alpha=1/4$ and it increases monotonically from zero for
+$\alpha \geq 1/4$. By deriving an effective low-energy theory of the dilute gas
+of fermions, we demonstrate that the Drude weight $K_{\rm th}$ of the thermal
+conductivity exhibits a similar dependence on $\alpha$ near the saturation
+field. Moreover, this theory predicts a transition between a two-component
+Tomonaga-Luttinger liquid and a vector-chiral phase at a critical value
+$\alpha=\alpha_c$ that agrees very well with previous density matrix
+renormalization group results. We also show that the resulting curve $K_{\rm
+th}(\alpha)$ is in excellent agreement with exact diagonalization (ED) results.
+Our ED results also show that $K_{\rm th}(\alpha)$ has a pronounced minimum at
+$\alpha\simeq 0.7$ and it decreases for sufficiently large $\alpha$ at lower
+magnetic field values. We also demonstrate that the thermal conductivity is
+significantly affected by the presence of magnetothermal coupling.",1809.08429v1
+2018-11-29,"High Saturation Magnetization, Low Coercivity and Fine YIG Nanoparticles Prepared by Modifying Co-Precipitation Method","Nanoparticles with their specific properties newly have drawn a great deal of
+attention of researchers [1-3]Yttrium iron Garnet magnetic nanoparticles
+(YIG-NPs) are promising materials with novel applications in microwave,
+spintronics, magnonics, and magneto-optical devices. However, achieving stable
+and remarkable magnetic YIG-NPs has been remaining as a great challenge. In
+this paper, synthesized YIG-NPs by modifying co-precipitation (MCP) method is
+reported. Structural and magnetic properties of final products are compared to
+those of the materials prepared by citrate-nitrate (CN) method. Smaller
+crystals and particle size have been found by MCP method comparing to that of
+synthesized by CN method. Using a relatively low annealing temperatures for
+both sets of samples (~700 {\deg}C), the final YIG samples prepared by MCP
+method show more structural purity than those made by CN method. Higher
+saturation magnetization (Ms) and lower coercivity (Hc) are observed in MCP YIG
+sample (23.23 emu/g 36 and 30.1 Oe) than the CN prepared YIG sample (16.43
+emu/g and 44.95 Oe). The Curie temperature is measured to be 569 {\deg}C for
+the MCP YIG sample determined from set of Ms measurement at different
+temperatures ranging from 80-600 K. These findings lead to significant
+improvement in quality of synthesized (synthetic methods) of YIG-NPs.",1811.12511v1
+2018-11-29,Structural and Magnetic Study of Metallo-Organic YIG Powder Using 2-ethylhexanoate Carboxylate Based Precursors,"The crystallization and magnetic behavior of yttrium iron garnet (YIG)
+prepared by metallo-organic decomposition (MOD) method are discussed. The
+chemistry and physics related to synthesis of iron and yttrium carboxylates
+based on 2-ethylhexanoic acid (2EHA) are studied, since no literature was found
+which elucidates synthesis of metallo-organic precursor of YIG in spite of the
+literatures of doped YIG samples such as Bi-YIG. Typically, the metal
+carboxylates used in preparation of ceramic oxide materials are
+2-ethylhexanoate (2EH) solvents. Herein, the synthesis, thermal behavior and
+solubility of yttrium and iron 2EH used in synthesis of YIG powder by MOD are
+reported. The crystallization and magnetic parameters, including saturation
+magnetization and coercivity of these samples, smoothly change as a function of
+the annealing temperature. It is observed that high sintering temperature of
+1300 to 1400 {\deg}C promotes the diffraction peaks of YIG, therefore, we can
+conclude that the formation of YIG in MOD method increases the crystallization
+temperature. The maximum value of saturation magnetization and minimum value of
+coercivity and remanence are observed for the sample sintered at 1200{\deg}C
+which are 13.7 emu/g, 10.38 Oe and 1.5 emu/g, respectively. This study cites
+the drawbacks in chemical synthesis of metallo-organic based YIG production.",1811.12514v1
+2019-01-09,"The magnetic phase diagram of the frustrated spin chain compound linarite, PbCuSO$_4$(OH)$_2$, as seen by neutron diffraction and $^1$H-NMR","We report on a detailed neutron diffraction and $^1$H-NMR study on the
+frustrated spin-1/2 chain material linarite, PbCuSO$_4$(OH)$_2$, where
+competing ferromagnetic nearest neighbor and antiferromagnetic next-nearest
+neighbor interactions lead to frustration. From the magnetic Bragg peak
+intensity studied down to 60 mK, the magnetic moment per Cu atom is obtained
+within the whole magnetic phase diagram for $H \parallel b$ axis. Further, we
+establish the detailed configurations of the shift of the SDW propagation
+vector in phase V with field and temperature. Finally, combining our neutron
+diffraction results with those from a low-temperature/high-field NMR study we
+find an even more complex phase diagram close to the quasi-saturation field
+suggesting that bound two-magnon excitations are the lowest energy excitations
+close to and in the quasi-saturation regime. Qualitatively and
+semi-quantitatively, we relate such behavior to $XYZ$ exchange anisotropy and
+contributions from the Dzyaloshinsky-Moriya interaction to affect the magnetic
+properties of linarite.",1901.02842v1
+2019-06-02,"Structural and magnetic properties of $La_{0.67}Ca_{0.33}MnO_3$ (D = Ca, Sr, Ba) manganites prepared by Ball milling","In this research, we report on the synthesis and characterization of
+$La_{0.67}Ca_{0.33}MnO_3$ (LCMO), $La_{0.67}Ba_{0.33}MnO_3$ (LBMO), and
+$La_{0.67}Sr_{0.33}MnO_3$ (LSMO) perovskites. Precursor powders for the
+perovskite samples were prepared using ball mailing technique. The resulting
+powder was pressed into disks which were subsequently sintered at 1000 C for
+2h. The structural characteristics of the prepared samples were investigated
+using X-ray diffraction (XRD) and scanning electron microscope (SEM), and the
+magnetic properties were investigated using vibrating sample magnetometry
+(VSM). XRD pattern of LCMO sample revealed a pure perovskite phase with Pnma
+space group, while the pattern of LSMO sample revealed a pure perovskite with
+R3c$^-$ space group. XRD pattern of LBMO sample, however, demonstrated the
+presence of a major perovskite phase with R3c$^-$ symmetry, together with a
+secondary $BaMnO_3$ phase. This secondary phase disappeared upon sintering LBMO
+at a higher temperature of 1100 C. Isothermal magnetic measurements and
+thermomagnetic curves revealed that LCMO was paramagnetic at room temperature.
+However, LSMO exhibited soft ferromagnetic behavior at room temperature, with
+Tc = 380 K and Ms = 50.9 emu/g. Also, LBMO sample sintered at 1000 C exhibited
+soft ferromagnetic behavior at room temperature, with Curie temperature Tc =
+343 K and a rather low saturation magnetization of Ms = 30.7 emu/g. The higher
+sintering temperature of LBMO compound resulted in a significant increase of
+the saturation magnetization to 50.8 emu/g for the sample sintered at 1100 C.",1906.00407v1
+2020-02-06,"Effects of transition-metal spacers on the spin-orbit torques, spin Hall magnetoresistance, and magnetic anisotropy of Pt/Co bilayers","We studied the effect of inserting 0.5 nm-thick spacer layers (Ti, V, Cr, Mo,
+W) at the Pt/Co interface on the spin-orbit torques, Hall effect,
+magnetoresistance, saturation magnetization, and magnetic anisotropy. We find
+that the damping-like spin-orbit torque decreases substantially for all samples
+with a spacer layer compared to the reference Pt/Co bilayer, consistently with
+the opposite sign of the atomic spin-orbit coupling constant of the spacer
+elements relative to Pt. The reduction of the damping-like torque is monotonic
+with atomic number for the isoelectronic 3d, 4d, and 5d elements, with the
+exception of V that has a stronger effect than Cr. The field-like spin-orbit
+torque almost vanishes for all spacer layers irrespective of their composition,
+suggesting that this torque predominantly originates at the Pt/Co interface.
+The anomalous Hall effect, magnetoresistance, and saturation magnetization are
+also all reduced substantially, whereas the sheet resistance is increased in
+the presence of the spacer layer. Finally, we evidence a correlation between
+the amplitude of the spin-orbit torques, the spin Hall-like magnetoresistance,
+and the perpendicular magnetic anisotropy. These results highlight the
+significant influence of ultrathin spacer layers on the magnetotransport
+properties of heavy metal/ferromagnetic systems.",2002.02162v1
+2020-12-15,Induced anomalous Hall effect of massive Dirac fermions in ZrTe5 and HfTe5 thin flakes,"Researches on anomalous Hall effect (AHE) have been lasting for a century to
+make clear the underlying physical mechanism. Generally, the AHE appears in
+magnetic materials, in which extrinsic process related to scattering effects
+and intrinsic contribution connected with Berry curvature are crucial.
+Recently, AHE has been counterintuitively observed in non-magnetic topological
+materials and attributed to the existence of Weyl points. However, the Weyl
+point scenario would lead to unsaturated AHE even in large magnetic fields and
+contradicts the saturation of AHE in several tesla (T) in experiments. In this
+work, we investigate the Hall effect of ZrTe5 and HfTe5 thin flakes in static
+ultrahigh magnetic fields up to 33 T. We find the AHE saturates to 55 (70)
+Ohm^-1*cm^-1 for ZrTe5 (HfTe5) thin flakes above ~ 10 T. Combining detailed
+magnetotransport experiments and Berry curvature calculations, we clarify that
+the splitting of massive Dirac bands without Weyl points can be responsible for
+AHE in non-magnetic topological materials ZrTe5 and HfTe5 thin flakes. This
+model can identify our thin flake samples to be weak topological insulators and
+serve as a new tool to probe the band structure topology in topological
+materials.",2012.08188v1
+2021-09-15,Formation and evolution of protostellar accretion discs. II. From 3D simulation to a simple semi-analytic model of Class 0/I discs,"We use a 3D radiative non-ideal magnetohydrodynamic (MHD) simulation to
+investigate the formation and evolution of a young protostellar disc from a
+magnetized pre-stellar core. The simulation covers the first ${\sim}10~{\rm
+kyr}$ after protostar formation, and shows a massive, weakly magnetized disc
+with radius that initially grows and then saturates at ${\sim}30~{\rm au}$. The
+disc is gravitationally unstable with prominent large-amplitude spiral arms. We
+use our simulation results and a series of physical arguments to construct a
+predictive and quantitative physical picture of Class 0/I protostellar disc
+evolution from several aspects, including (i) the angular-momentum
+redistribution in the disc, self-regulated by gravitational instability to make
+most of the disc marginally unstable; (ii) the thermal profile of the disc,
+well-approximated by a balance between radiative cooling and accretion heating;
+and (iii) the magnetic-field strength and magnetic-braking rate inside the
+disc, regulated by non-ideal magnetic diffusion. Using these physical insights,
+we build a simple 1D semi-analytic model of disc evolution. We show that this
+1D model, when coupled to a computationally inexpensive simulation for the
+evolution of the surrounding pseudodisc, can be used reliably to predict disc
+evolution in the Class 0/I phase. The predicted long-term evolution of disc
+size, which saturates at ${\sim}30~{\rm au}$ and eventually shrinks, is
+consistent with a recent observational survey of Class 0/I discs. Such
+hierarchical modelling of disc evolution circumvents the computational
+difficulty of tracing disc evolution through Class 0/I phase with direct,
+numerically converged simulations.",2109.07535v1
+2023-09-01,Saturation of the anomalous Hall effect at high magnetic fields in altermagnetic RuO2,"Observations of the anomalous Hall effect in RuO$_2$ and MnTe have
+demonstrated unconventional time-reversal symmetry breaking in the electronic
+structure of a recently identified new class of compensated collinear magnets,
+dubbed altermagnets. While in MnTe the unconventional anomalous Hall signal
+accompanied by a vanishing magnetization is observable at remanence, the
+anomalous Hall effect in RuO$_2$ is excluded by symmetry for the N\'eel vector
+pointing along the zero-field [001] easy-axis. Guided by a symmetry analysis
+and ab initio calculations, a field-induced reorientation of the N\'eel vector
+from the easy-axis towards the [110] hard-axis was used to demonstrate the
+anomalous Hall signal in this altermagnet. We confirm the existence of an
+anomalous Hall effect in our RuO$_2$ thin-film samples whose set of magnetic
+and magneto-transport characteristics is consistent with the earlier report. By
+performing our measurements at extreme magnetic fields up to 68 T, we reach
+saturation of the anomalous Hall signal at a field $H_{\rm c} \simeq$ 55 T that
+was inaccessible in earlier studies, but is consistent with the expected
+N\'eel-vector reorientation field.",2309.00568v1
+2017-10-17,Rapid and Quantitative Chemical Exchange Saturation Transfer (CEST) Imaging with Magnetic Resonance Fingerprinting (MRF),"Purpose: To develop a fast magnetic resonance fingerprinting (MRF) method for
+quantitative chemical exchange saturation transfer (CEST) imaging.
+  Methods: We implemented a CEST-MRF method to quantify the chemical exchange
+rate and volume fraction of the N${\alpha}$-amine protons of L-arginine (L-Arg)
+phantoms and the amide and semi-solid exchangeable protons of in vivo rat brain
+tissue. L-Arg phantoms were made with different concentrations (25-100 mM) and
+pH (pH 4-6). The MRF acquisition schedule varied the saturation power randomly
+for 30 iterations (phantom: 0-6 ${\mu}$T; in vivo: 0-4 ${\mu}$T) with a total
+acquisition time of <=2 minutes. The signal trajectories were pattern-matched
+to a large dictionary of signal trajectories simulated using the
+Bloch-McConnell equations for different combinations of exchange rate,
+exchangeable proton volume fraction, and water T1 and T2* relaxation times.
+  Results: The chemical exchange rates of the N${\alpha}$-amine protons of
+L-Arg were significantly (p<0.0001) correlated with the rates measured with the
+Quantitation of Exchange using Saturation Power method. Similarly, the L-Arg
+concentrations determined using MRF were significantly (p<0.0001) correlated
+with the known concentrations. The pH dependence of the exchange rate was well
+fit (R2=0.9186) by a base catalyzed exchange model. The amide proton exchange
+rate measured in rat brain cortex (36.3+-12.9 Hz) was in good agreement with
+that measured previously with the Water Exchange spectroscopy method (28.6+-7.4
+Hz). The semi-solid proton volume fraction was elevated in white (11.2+-1.7%)
+compared to gray (7.6+-1.8%) matter brain regions in agreement with previous
+magnetization transfer studies.
+  Conclusion: CEST-MRF provides a method for fast, quantitative CEST imaging.",1710.06054v2
+2022-08-10,Magnetic braking saturates: evidence from the orbital period distribution of low-mass detached eclipsing binaries from ZTF,"We constrain the orbital period ($P_{\rm orb}$) distribution of low-mass
+detached main-sequence eclipsing binaries (EBs) with light curves from the
+Zwicky Transient Facility (ZTF), which provides a well-understood selection
+function and sensitivity to faint stars. At short periods ($P_{\rm orb}\lesssim
+2$ days), binaries are predicted to evolve significantly due to magnetic
+braking (MB), which shrinks orbits and ultimately brings detached binaries into
+contact. The period distribution is thus a sensitive probe of MB. We find that
+the intrinsic period distribution of low-mass ($0.1\lesssim M_1/M_{\odot} <
+0.9$) binaries is basically flat (${\rm d}N/{\rm d}P_{\rm orb} \propto P_{\rm
+orb}^0$), from $P_{\rm orb}=10$ days down to the contact limit. This is
+strongly inconsistent with predictions of classical MB models based on the
+Skumanich relation, which are widely used in binary evolution calculations and
+predict ${\rm d}N/{\rm d}P_{\rm orb} \propto P_{\rm orb}^{7/3}$ at short
+periods. The observed distributions are best reproduced by models in which the
+magnetic field saturates at short periods, with a MB torque that scales roughly
+as $\dot{J}\propto P_{\rm orb}^{-1}$, as opposed to $\dot{J} \propto P_{\rm
+orb}^{-3}$ in the standard Skumanich law. We also find no significant
+difference between the period distributions of binaries containing fully and
+partially convective stars. Our results confirm that a saturated MB law, which
+was previously found to describe the spin-down of rapidly rotating isolated M
+dwarfs, also operates in tidally locked binaries. We advocate using saturated
+MB models in binary evolution calculations. Our work supports previous
+suggestions that MB in cataclysmic variables (CVs) is much weaker than assumed
+in the standard evolutionary model, unless mass transfer leads to significant
+additional angular momentum loss in CVs.",2208.05488v2
+2017-01-24,Magnetic field formation in the Milky Way-like disk galaxies of the Auriga project,"The magnetic fields observed in the Milky~Way and nearby galaxies appear to
+be in equipartition with the turbulent, thermal, and cosmic ray energy
+densities, and hence are expected to be dynamically important. However, the
+origin of these strong magnetic fields is still unclear, and most previous
+attempts to simulate galaxy formation from cosmological initial conditions have
+ignored them altogether. Here, we analyse the magnetic fields predicted by the
+simulations of the Auriga Project, a set of 30 high-resolution cosmological
+zoom simulations of Milky~Way-like galaxies, carried out with a moving-mesh
+magneto-hydrodynamics code and a detailed galaxy formation physics model. We
+find that the magnetic fields grow exponentially at early times owing to a
+small-scale dynamo with an e-folding time of roughly $100\,\rm{Myr}$ in the
+center of halos until saturation occurs around $z=2-3$, when the magnetic
+energy density reaches about $10\%$ of the turbulent energy density with a
+typical strength of $10-50\,\rm{\mu G}$. In the galactic centers the ratio
+between magnetic and turbulent energy remains nearly constant until $z=0$. At
+larger radii, differential rotation in the disks leads to linear amplification
+that typically saturates around $z=0.5$ to $z=0$. The final radial and vertical
+variations of the magnetic field strength can be well described by two joint
+exponential profiles, and are in good agreement with observational constraints.
+Overall, the magnetic fields have only little effect on the global evolution of
+the galaxies as it takes too long to reach equipartition. We also demonstrate
+that our results are well converged with numerical resolution.",1701.07028v2
+2020-12-03,Magnetic fields in elliptical galaxies: an observational probe of the fluctuation dynamo action,"Fluctuation dynamos are thought to play an essential role in magnetized
+galaxy evolution, saturating within $\sim0.01~$Gyr and thus potentially acting
+as seeds for large-scale dynamos. However, unambiguous observational
+confirmation of the fluctuation dynamo action in a galactic environment is
+still missing. This is because, in spiral galaxies, it is difficult to
+differentiate between small-scale magnetic fields generated by a fluctuation
+dynamo and those due to the tangling of the large-scale field. We propose that
+observations of magnetic fields in elliptical galaxies would directly probe the
+fluctuation dynamo action. This is motivated by the fact that in ellipticals,
+due to their lack of significant rotation, the conventional large-scale dynamo
+is absent and the fluctuation dynamo is responsible for controlling the
+magnetic field strength and structure. By considering turbulence injected by
+Type Ia supernova explosions and possible magnetic field amplification by
+cooling flows, we estimate expected magnetic field strengths of $0.2~-~1
+\,\mu{\rm G}$ in quiescent elliptical galaxies. We use a semi-analytic model of
+galaxy formation to estimate the distribution and redshift evolution of field
+strengths, tentatively finding a decrease in magnetic field strength with
+decreasing redshift. We analyse a sample of radio sources that exhibit the
+Laing-Garrington (LG) effect (radio polarization asymmetry in jets) and infer
+magnetic field strengths between $0.14~-~1.33 \,\mu{\rm G}$ for a uniform
+thermal electron density and between $1.36~-~6.21\,\mu{\rm G}$ for the thermal
+electron density following the King profile. We examine observational
+techniques for measuring the magnetic field saturation state in elliptical
+galaxies, focusing on Faraday RM grids, the LG effect, synchrotron emission,
+and gravitational lensing, finding appealing prospects for future empirical
+analysis.",2012.02329v1
+2021-01-26,Data-driven design of a new class of rare-earth free permanent magnets,"A new class of rare-earth-free permanent magnets is proposed. The parent
+compound of this class is Co$_3$Mn$_2$Ge, and its discovery is the result of
+first principles theory combined with experimental synthesis and
+characterisation. The theory is based on a high-throughput/data-mining search
+among materials listed in the ICSD database. From ab-initio theory of the
+defect free material it is predicted that the saturation magnetization is 1.71
+T, the uniaxial magnetocrystalline anisotropy is 1.44 MJ/m$^3$, and the Curie
+temperature is 700 K. Co$_3$Mn$_2$Ge samples were then synthesized and
+characterised with respect to structure and magnetism. The crystal structure
+was found to be the MgZn$_2$-type, with partial disorder of Co and Ge on the
+crystallographic lattice sites. From magnetization measurements a saturation
+polarization of 0.86 T at 10 K was detected, together with a uniaxial
+magnetocrystalline anisotropy constant of 1.18 MJ/m$^3$, and the Curie
+temperature of $T_{\rm C}$ = 359 K. These magnetic properties make
+Co$_3$Mn$_2$Ge a very promising material as a rare-earth free permanent magnet,
+and since we can demonstrate that magnetism depends critically on the amount of
+disorder of the Co and Ge atoms, a further improvement of the magnetism is
+possible. From the theoretical works, a substitution of Ge by neighboring
+elements suggest two other promising materials - Co$_3$Mn$_2$Al and
+Co$_3$Mn$_2$Ga. We demonstrate here that the class of compounds based on
+$T_3$Mn$_2$X (T = Co or alloys between Fe and Ni; X=Ge, Al or Ga) in the
+MgZn$_2$ structure type, form a new class of rare-earth free permanent magnets
+with very promising performance.",2101.10773v1
+2021-09-06,"The planar triangular $S=3/2$ magnet AgCrSe$_2$: magnetic frustration, short range correlations, and field tuned anisotropic cycloidal magnetic order","Our studies evidence an anisotropic magnetic order below $T_N = 32$~K.
+Susceptibility data in small fields of about 1~T reveal an antiferromagnetic
+(AFM) order for $H \perp c$, whereas for $H \parallel c$ the data are
+reminiscent of a field-induced ferromagnetic (FM) structure. At low
+temperatures and for $H \perp c$, the field-dependent magnetization and AC
+susceptibility data evidence a metamagnetic transition at $H^+ = 5$~T, which is
+absent for $H \parallel c$. We assign this to a transition from a planar
+cycloidal spin structure at low fields to a planar fan-like arrangement above
+$H^+$. A fully FM polarized state is obtained above the saturation field of
+$H_{\perp S} = 23.7$~T at 2~K with a magnetization of $M_s = 2.8$~$\mu_{\rm
+B}{\rm /Cr}$. For $H \parallel c$, $M(H)$ monotonously increases and saturates
+at the same $M_s$ value at $H_{\parallel S} = 25.1$~T at 4.2~K. Above $T_N $,
+the magnetic susceptibility and specific heat indicate signatures of two
+dimensional (2D) frustration related to the presence of planar ferromagnetic
+and antiferromagnetic exchange interactions. We found a pronounced nearly
+isotropic maximum in both properties at about $T^* = 45$~K, which is a clear
+fingerprint of short-range correlations and emergent spin fluctuations.
+Calculations based on a planar 2D Heisenberg model support our experimental
+findings and suggest a predominant FM exchange among nearest and AFM exchange
+among third-nearest neighbors. Only a minor contribution might be assigned to
+the antisymmetric Dzyaloshinskii-Moriya interaction possible related to the
+non-centrosymmetric polar space group $R3m$. Due to these competing
+interactions, the magnetism in AgCrSe$_{2}$, in contrast to the oxygen based
+delafossites, can be tuned by relatively small, experimentally accessible,
+magnetic fields, allowing us to establish the complete anisotropic magnetic
+$H-T$ phase diagram in detail.",2109.02582v1
+2022-01-19,Tearing instability and current-sheet disruption in the turbulent dynamo,"Turbulence in a conducting plasma can amplify seed magnetic fields in what is
+known as the turbulent, or small-scale, dynamo. The associated growth rate and
+emergent magnetic-field geometry depend sensitively on the material properties
+of the plasma, in particular on the Reynolds number ${\rm Re}$, the magnetic
+Reynolds number ${\rm Rm}$, and their ratio ${\rm Pm}\equiv{\rm Rm}/{\rm Re}$.
+For ${\rm Pm} > 1$, the amplified magnetic field is gradually arranged into a
+folded structure, with direction reversals at the resistive scale and field
+lines curved at the larger scale of the flow. As the mean magnetic energy grows
+to come into approximate equipartition with the fluid motions, this folded
+structure is thought to persist. Using analytical theory and high-resolution
+MHD simulations with the Athena++ code, we show that these magnetic folds
+become unstable to tearing during the nonlinear stage of the dynamo for ${\rm
+Rm}\gtrsim 10^4$ and ${\rm Re}\gtrsim 10^3$. An ${\rm Rm}$- and ${\rm
+Pm}$-dependent tearing scale, at and below which folds are disrupted, is
+predicted theoretically and found to match well the characteristic
+field-reversal scale measured in the simulations. The disruption of folds by
+tearing increases the ratio of viscous-to-resistive dissipation. In the
+saturated state, the magnetic-energy spectrum exhibits a sub-tearing-scale
+steepening to a slope consistent with that predicted for tearing-mediated
+Alfv\'enic turbulence. Its spectral peak appears to be independent of the
+resistive scale and comparable to the driving scale of the flow, while the
+magnetic energy resides in a broad range of scales extending down to the
+field-reversal scale set by tearing. Emergence of a degree of large-scale
+magnetic coherence in the saturated state of the turbulent dynamo may be
+consistent with observations of magnetic-field fluctuations in galaxy clusters
+and recent laboratory experiments.",2201.07757v2
+1999-04-09,Electron-Cyclotron-Maser Observable Modes,"We investigated wave amplification through the Electron-Cyclotron-Maser
+mechanism.
+  We calculated absorption and emission coefficients without any
+approximations, also taking into account absorption by the ambient thermal
+plasma. A power-law energy distribution for the fast electrons was used, as is
+indicated by X-ray and microwave observations.
+  We developed a model for the saturation length and amplification ratio of the
+maser, scanned a large parameter space, and calculated the absorption and
+emission coefficients for every frequency and angle.
+  Previous studies concluded that the unobservable Z-mode dominates in the nu_p
+\~ nu_B region, and that millisecond spikes are produced in the region nu_p /
+nu_B<0.25. We find that the observable O-mode and X-mode can produce emission
+in the 0.8<nu_p / nu_B<2 region, which is expected at the footpoints of a
+flaring magnetic loop.
+  The important criterion for observability is the saturation length and not
+the growth rate, as was assumed previously, and even when the Z-mode is the
+most strongly amplified, less strongly amplified O-mode or X-mode are still
+intense enough to be observed.
+  The brightness temperature computed with our model for the saturation length
+is found to be of order 10^{16} K and higher. The emission is usually at a
+frequency of 2.06 nu_B, and at angles 30-60 degrees to the magnetic field. The
+rise time of the amplified emission to maximum is a few tenths of a millisecond
+to a few milliseconds, and the emission persists for as long as new fast
+electrons arrive into the maser region.",9904119v1
+2004-02-23,Stellar models of evolved secondaries in CVs,"In this paper we study the impact of chemically evolved secondaries on CV
+evolution. We find that when evolved secondaries are included a spread in the
+secondary mass-orbital period plane comparable to that seen in the data is
+produced for either the saturated prescription for magnetic braking or the
+unsaturated model commonly used for CVs. We argue that in order to explain this
+spread a considerable fraction of all CVs should have evolved stars as the
+secondaries. The evolved stars become fully convective at lower orbital
+periods. Therefore, even if there was an abrupt decrease in magnetic braking
+for fully convective stars (contrary to open cluster data) it would not be
+expected to produce a sharp break in the period distribution for CVs. We also
+explore recent proposed revisions to the angular momentum loss rate for single
+stars, and find that only modest increases over the saturated prescription are
+consistent with the overall observed spindown pattern. We compare predictions
+of our models with diagnostics of the mass accretion rate in WDs and find
+results intermediate between the saturated and the older braking prescription.
+Taken together these suggest that the angular momentum loss rate may be higher
+in CV secondaries than in single stars of the same rotation period, but is
+still significantly lower than in the traditional model. Alternative
+explanations for the CV period gap are discussed.",0402536v2
+1999-08-10,Existence of Saturated Ferromagnetic and Spiral States in 1D Lieb-Ferrimagnetic Models away from Half-Filling,"In order to study conditions for the appearance of ferromagnetism in a wide
+filling region, we investigate numerically three types of one-dimensional
+Lieb-ferrimagnetic Hubbard models: a periodic diamond (PD) chain, a periodic
+alternately-attached leg (PAAL) chain and an open diamond (OD) chain. All of
+these models have a flat band (or equivalently, degenerate single-electron
+eigenvalues). The PD and OD chains commonly have a local-loop structure.
+Nagaoka's theorem holds only in the PD chain. At half-filling, it have been
+rigorously proven that all of these models are ferrimagnet. Away from
+half-filling, however, quite different magnetic properties are found. In the
+fillings 1/3< rho_e <1/2, the ground state of the PD chain for a
+infinitely-large U is the extended ferromagnetic state, that is, the saturated
+ferromagnetic state or the spiral state for odd or even number of electrons,
+respectively. In the PAAL chain, on the other hand, there is no magnetic order.
+Thus, the flat band is found to be not a sufficient condition of the extended
+ferromagnetic state. We find, moreover, that the saturated ferromagnetism
+appears in the OD chain, although the Nagaoka theorem does not hold on this
+chain. This indicates that the local-loop structure plays an important role on
+the appearance of the extended ferromagnetic state.",9908144v1
+2013-09-26,Stellar Magnetic Dynamos and Activity Cycles,"Using a new uniform sample of 824 solar and late-type stars with measured
+X-ray luminosities and rotation periods we have studied the relationship
+between rotation and stellar activity that is believed to be a probe of the
+underlying stellar dynamo. Using an unbiased subset of the sample we calculate
+the power law slope of the unsaturated regime of the activity -- rotation
+relationship as $L_X/L_{bol}\propto Ro^\beta$, where $\beta=-2.70\pm0.13$. This
+is inconsistent with the canonical $\beta = -2$ slope to a confidence of
+5$\sigma$ and argues for an interface-type dynamo. We map out three regimes of
+coronal emission as a function of stellar mass and age, using the empirical
+saturation threshold and theoretical super-saturation thresholds. We find that
+the empirical saturation timescale is well correlated with the time at which
+stars transition from the rapidly rotating convective sequence to the slowly
+rotating interface sequence in stellar spin-down models. This may be hinting at
+fundamental changes in the underlying stellar dynamo or internal structure. We
+also present the first discovery of an X-ray unsaturated, fully convective M
+star, which may be hinting at an underlying rotation - activity relationship in
+fully convective stars hitherto not observed. Finally we present early results
+from a blind search for stellar X-ray cycles that can place valuable
+constraints on the underlying ubiquity of solar-like activity cycles.",1309.6970v1
+2016-10-05,The weakly nonlinear magnetorotational instability in a local geometry,"The magnetorotational instability (MRI) is a fundamental process of accretion
+disk physics, but its saturation mechanism remains poorly understood despite
+considerable theoretical and computational effort. We present a multiple scales
+analysis of the non-ideal MRI in the weakly nonlinear regime -- that is, when
+the most unstable MRI mode has a growth rate asymptotically approaching zero
+from above. Here, we develop our theory in a local, Cartesian channel. Our
+results confirm the finding by Umurhan et al. (2007) that the perturbation
+amplitude follows a Ginzburg-Landau equation. We further find that the
+Ginzburg-Landau equation will arise for the local MRI system with
+shear-periodic boundary conditions when the effects of ambipolar diffusion are
+considered. A detailed force balance for the saturated azimuthal velocity and
+vertical magnetic field demonstrates that even when diffusive effects are
+important, the bulk flow saturates via the combined processes of reducing the
+background shear and rearranging and strengthening the background vertical
+magnetic field. We directly simulate the Ginzburg-Landau amplitude evolution
+for our system and demonstrate the pattern formation our model predicts on long
+length and time scales. We compare the weakly nonlinear theory results to a
+direct numerical simulation of the MRI in a thin-gap Taylor Couette flow.",1610.01616v2
+2019-05-13,"Characterizing maser polarization: effects of saturation, anisotropic pumping and hyperfine structure","The polarization of masers contains information on the magnetic field
+strength and direction of the regions they occur in. Many maser polarization
+observations have been performed over the last 30 years. However, versatile
+maser polarization models that can aide in the interpretation of these
+observations are not available. We aim to develop a program suite that can
+compute the polarization by a magnetic field of any non-paramagnetic maser
+specie at arbitrarily high maser saturation. Furthermore, we aim to investigate
+the polarization of masers by non-Zeeman polarizing effects. We aim to present
+a general interpretive structure for maser polarization observations. We expand
+existing maser polarization theories of non-paramagnetic molecules and
+incorporate these in a numerical modeling program suite. We present a modeling
+program that CHAracterizes Maser Polarization (CHAMP) that can examine the
+polarization of masers of arbitrarily high maser saturation and high angular
+momentum. Also, hyperfine multiplicity of the maser-transition can be
+incorporated. The user is able to investigate non-Zeeman polarizing mechanisms
+such as anisotropic pumping and polarized incident seed radiation. We present
+an analysis of the polarization of v = 1 SiO masers and the 22 GHz water maser.
+We comment on the underlying polarization mechanisms, and also investigate
+non-Zeeman effects. We identify the regimes where different polarizing
+mechanisms will be dominant and present the polarization characteristics of the
+SiO and water masers. From the results of our calculations, we identify markers
+to recognize alternative polarization mechanisms.",1905.04868v1
+2020-12-22,A two-dimensional disordered magnetic metamaterial,"We study the effect of a resonant frequency disorder on the eigenstates and
+the transport of magnetic energy in a two-dimensional (square) array of
+split-ring resonators (SRRs). In the absence of disorder, we find the
+dispersion relation of magneto-inductive waves and the mean square displacement
+(MSD) in closed form, showing that at long times the MSD is ballistic. When
+disorder is present, we consider two types: the usual Anderson distribution
+(uncorrelated monomers) and $2 \times 2$ units assigned at random to lattice
+sites (correlated tetramers). This is a direct extension to two dimensions of
+the one-dimensional random dimer model (RDM). For the uncorrelated case, we see
+saturation of the MSD for all disorder widths, while for the correlated case we
+find a disorder window, inside which the MSD does not saturate at long times,
+with an asymptotic sub-diffusive behavior $MSD\sim t^{0.26}$. Outside this
+disorder window, the MSD shows the same kind of saturation as in the monomer
+case. We conjecture that the sub-diffusive behavior is a remanent of a weak
+resonant transmission of a 2D plane wave across a tetramer unit.",2012.12043v4
+2021-06-09,Scaling of Small-Scale Dynamo Properties in the Rayleigh-Taylor Instability,"We derive scaling relations based on free-fall and isotropy assumptions for
+the kinematic small-scale dynamo growth rate and amplification factor over the
+course of the mixing, saturation, and decay phases of the Rayleigh-Taylor
+instability (RTI) in a fully-ionized plasma. The scaling relations are tested
+using sets of three dimensional, visco-resistive MHD simulations of the RTI and
+found to hold in the saturation phase, but exhibit discrepancies during the
+mixing and decays phases, suggesting a need to relax either the free-fall or
+isotropy assumptions. Application of the scaling relations allows for
+quantitative prediction of the net amplification of magnetic energy in the
+kinematic dynamo phase and therefore a determination of whether the magnetic
+energy either remains sub-equipartition at all velocity scales or reaches
+equipartition with at least some scales of the turbulent kinetic energy in
+laboratory and astrophysical scenarios. As an example, we consider the dynamo
+in RTI-unstable regions of the outer envelope of a binary neutron star merger
+and predict that the kinematic regime of the small-scale dynamo ends on the
+time scale of nanoseconds and then reaches saturation on a timescale of
+microseconds, which are both fast compared to the millisecond relaxation time
+of the post-merger.",2106.04787v2
+2022-12-04,"Effects of geometry, boundary condition and dynamical rules on the magnetic relaxation of Ising ferromagnet","We have studied the magnetic relaxation behavior of a two-dimensional Ising
+ferromagnet by Monte Carlo simulation. Our primary goal is to investigate the
+effects of the system's geometry (area preserving) , boundary conditions, and
+dynamical rules on the relaxation behavior. The Glauber and Metropolis
+dynamical rules have been employed. The systems with periodic and open boundary
+conditions are studied. The major findings are the exponential relaxation and
+the dependence of relaxation time ($\tau$) on the aspect ratio $R$ (length over
+breadth having fixed area). A power law dependence ($\tau \sim R^{-s}$) has
+been observed for larger values of aspect ratio ($R$). The exponent ($s$) has
+been found to depend linearly ($s=aT+b$) on the system's temperature ($T$). The
+transient behaviours of the spin-flip density have been investigated for both
+surface and bulk/core. The size dependencies of saturated spin-flip density
+significantly differ for the surface and the bulk/core. Both the saturated
+bulk/core and saturated surface spin-flip density was found to follow the
+logarithmic dependence $f_d = a + b~log(L)$ with the system size. The faster
+relaxation was observed for open boundary condition with any kind
+(Metropolis/Glauber) of dynamical rule. Similarly, Metropolis algorithm yields
+faster relaxation for any kind (open/periodic) of boundary condition.",2212.01858v2
+2022-07-25,On the centeredness of saturated ideals,"We show that Kunen's saturated ideal over $\aleph_1$ is not centered. We also
+evaluate the extent of saturation of Laver's saturated ideal in terms of
+$(\kappa,\lambda,<\nu)$-saturation.",2207.11959v1
+2006-01-17,Global Three-Dimensional MHD Simulations of Galactic Gaseous Disks: I. Amplification of Mean Magnetic Fields in Axisymmetric Gravitational Potential,"We carried out global three-dimensional resistive magnetohydrodynamic
+simulations of galactic gaseous disks to investigate how the galactic magnetic
+fields are amplified and maintained. We adopt a steady axisymmetric
+gravitational potential given by \cite*{Miy80}. As the initial condition, we
+assume a warm ($T\sim10^{5} \mathrm{K}$) rotating gas torus centered at
+$\varpi=10 \mathrm{kpc}$ threaded by weak azimuthal magnetic fields. Numerical
+results indicate that in differentially rotating galactic gaseous disks,
+magnetic fields are amplified due to magneto-rotational instability and
+magnetic turbulence develops. After the amplification of magnetic energy
+saturates, the disk stays in a quasi-steady state. The mean azimuthal magnetic
+field increases with time and shows reversals with period of 1Gyr (2Gyr for a
+full cycle). The amplitude of $B_{\phi}$ near the equatorial plane is
+$B_{\phi}\sim1.5\mu \mathrm{G}$ at $\varpi=5 \mathrm{kpc}$. The magnetic fields
+show large fluctuations whose standard deviation is comparable to the mean
+field. The mean azimuthal magnetic field in the disk corona has direction
+opposite to the mean magnetic field inside the disk. The mass accretion rate
+driven by the Maxwell stress is $\sim10^{-3}M_{\odot}/ \mathrm{yr}$ at
+$\varpi=2.5 \mathrm{kpc}$ when the mass of the initial torus is
+$\sim5\times10^{8}M_{\odot}$.",0601358v2
+2006-09-10,Nonlinear shear-current dynamo and magnetic helicity transport in sheared turbulence,"The nonlinear mean-field dynamo due to a shear-current effect in a nonhelical
+homogeneous turbulence with a mean velocity shear is discussed. The transport
+of magnetic helicity as a dynamical nonlinearity is taken into account. The
+shear-current effect is associated with the ${\bf W} {\bf \times} {\bf J}$ term
+in the mean electromotive force, where ${\bf W}$ is the mean vorticity due to
+the large-scale shear motions and ${\bf J}$ is the mean electric current. This
+effect causes the generation of large-scale magnetic field in a turbulence with
+large hydrodynamic and magnetic Reynolds numbers. The dynamo action due to the
+shear-current effect depends on the spatial scaling of the correlation time
+$\tau(k)$ of the background turbulence, where $k$ is the wave number. For
+Kolmogorov scaling, $\tau(k) \propto k^{-2/3}$, the dynamo instability occurs,
+while when $\tau(k) \propto k^{-2}$ (small hydrodynamic and magnetic Reynolds
+numbers) there is no the dynamo action in a sheared nonhelical turbulence. The
+magnetic helicity flux strongly affects the magnetic field dynamics in the
+nonlinear stage of the dynamo action. Numerical solutions of the nonlinear
+mean-field dynamo equations which take into account the shear-current effect,
+show that if the magnetic helicity flux is not small, the saturated level of
+the mean magnetic field is of the order of the equipartition field determined
+by the turbulent kinetic energy. Turbulence with a large-scale velocity shear
+is a universal feature in astrophysics, and the obtained results can be
+important for elucidation of origin of the large-scale magnetic fields in
+astrophysical sheared turbulence.",0609256v1
+2006-07-12,Title Cluster-Variational Treatment of Disordered Mixed Spin Ising Model,"A disordered alloy Ap B1-p where both A and B represent the magnetic atoms
+with respective spin SA =1/2 and SB =1 and whose magnetic interaction can be
+described through Ising Hamiltonian is treated using the cluster-variational
+method. In this method it is assumed that the system is built out of building
+block which is embedded in an effective field. Taking building block as 4-atom
+cluster the approximate free energy of the alloy is then obtained by treating
+the interactions between spins within the cluster of all possible
+configurations in exact manner and the rest of the interaction by an effective
+variational field . The magnetization M and transition temperature Tc are then
+calculated for different concentration and exchange parameters (JAA, JBB and
+JAB). The magnetization M exhibits different kinds of ferrimagnetic behaviour
+depending on concentration and relative strength of intra- and inter-
+sub-network exchange interactions. For antiferromagnetic JAB, the sub-network
+magnetization saturates and aligned antiferromagnetically at low temperature.
+The existence of compensation temperature Tcm, where total magnetization
+reverses its direction, depends sensitively on relative values of JAA/ JAB and
+JBB/ JAB and p. For B (A)-rich alloy with small JAB, the direction of net
+magnetization remains same upto Tc and a maximum of M appears at intermediate T
+< Tc when JBB>> JAA (JBB<< JAA).When magnitude of JAB > JAA, JBB, Tc exhibits a
+maximum with p. The transition temperature is much less than the mean-field
+value for all cases. The magnetic susceptibility for diverges and is
+Curie-Wiess like at T >>Tc. The meta-magnetic behaviour at high magnetic field
+has been found. Some of these results are in tune with experimental observation
+in amorphous rare-earth-transition metal alloys.",0607299v1
+2006-02-17,"Numerical simulations of current generation and dynamo excitation in a mechanically-forced, turbulent flow","The role of turbulence in current generation and self-excitation of magnetic
+fields has been studied in the geometry of a mechanically driven, spherical
+dynamo experiment, using a three dimensional numerical computation. A simple
+impeller model drives a flow which can generate a growing magnetic field,
+depending upon the magnetic Reynolds number, Rm, and the fluid Reynolds number.
+When the flow is laminar, the dynamo transition is governed by a simple
+threshold in Rm, above which a growing magnetic eigenmode is observed. The
+eigenmode is primarily a dipole field tranverse to axis of symmetry of the
+flow. In saturation the Lorentz force slows the flow such that the magnetic
+eigenmode becomes marginally stable. For turbulent flow, the dynamo eigenmode
+is suppressed. The mechanism of suppression is due to a combination of a time
+varying large-scale field and the presence of fluctuation driven currents which
+effectively enhance the magnetic diffusivity. For higher Rm a dynamo reappears,
+however the structure of the magnetic field is often different from the laminar
+dynamo; it is dominated by a dipolar magnetic field which is aligned with the
+axis of symmetry of the mean-flow, apparently generated by fluctuation-driven
+currents. The fluctuation-driven currents have been studied by applying a weak
+magnetic field to laminar and turbulent flows. The magnetic fields generated by
+the fluctuations are significant: a dipole moment aligned with the symmetry
+axis of the mean-flow is generated similar to those observed in the experiment,
+and both toroidal and poloidal flux expulsion are observed.",0602126v2
+2007-10-21,New mechanism of generation of large-scale magnetic field in a sheared turbulent plasma,"A review of recent studies on a new mechanism of generation of large-scale
+magnetic field in a sheared turbulent plasma is presented. This mechanism is
+associated with the shear-current effect which is related to the W x J-term in
+the mean electromotive force. This effect causes the generation of the
+large-scale magnetic field even in a nonrotating and nonhelical homogeneous
+sheared turbulent convection whereby the alpha effect vanishes. It is found
+that turbulent convection promotes the shear-current dynamo instability, i.e.,
+the heat flux causes positive contribution to the shear-current effect.
+However, there is no dynamo action due to the shear-current effect for small
+hydrodynamic and magnetic Reynolds numbers even in a turbulent convection, if
+the spatial scaling for the turbulent correlation time is k^{-2}, where k is
+the small-scale wave number. We discuss here also the nonlinear mean-field
+dynamo due to the shear-current effect and take into account the transport of
+magnetic helicity as a dynamical nonlinearity. The magnetic helicity flux
+strongly affects the magnetic field dynamics in the nonlinear stage of the
+dynamo action. When the magnetic helicity flux is not small, the saturated
+level of the mean magnetic field is of the order of the equipartition field
+determined by the turbulent kinetic energy. The obtained results are important
+for elucidation of origin of the large-scale magnetic fields in astrophysical
+and cosmic sheared turbulent plasma.",0710.3934v1
+2008-12-11,Magnetic properties of undoped Cu2O fine powders with magnetic impurities and/or cation vacancies,"Fine powders of micron- and submicron-sized particles of undoped Cu2O
+semiconductor, with three different sizes and morphologies have been
+synthesized by different chemical processes. These samples include nanospheres
+200 nm in diameter, octahedra of size 1 micron, and polyhedra of size 800 nm.
+They exhibit a wide spectrum of magnetic properties. At low temperature, T = 5
+K, the octahedron sample is diamagnetic. The nanosphere is paramagnetic. The
+other two polyhedron samples synthesized in different runs by the same process
+are found to show different magnetic properties. One of them exhibits weak
+ferromagnetism with T_C = 455 K and saturation magnetization, M_S = 0.19 emu/g
+at T = 5 K, while the other is paramagnetic. The total magnetic moment
+estimated from the detected impurity concentration of Fe, Co, and Ni, is too
+small to account for the observed magnetism by one to two orders of magnitude.
+Calculations by the density functional theory (DFT) reveal that cation
+vacancies in the Cu2O lattice are one of the possible causes of induced
+magnetic moments. The results further predict that the defect-induced magnetic
+moments favour a ferromagnetically coupled ground state if the local
+concentration of cation vacancies, n_C, exceeds 12.5%. This offers a possible
+scenario to explain the observed magnetic properties. The limitations of the
+investigations in the present work, in particular in the theoretical
+calculations, are discussed and possible areas for further study are suggested.",0812.2079v1
+2012-01-30,High--field NMR of the quasi--1D antiferromagnet LiCuVO$_4$,"We report on NMR studies of the quasi one--dimensional (1D) antiferromagnetic
+$S=1/2$ chain cuprate LiCuVO$_4$ in magnetic fields $H$ up to $\mu_0H$ = 30 T
+($\approx 70$% of the saturation field $H_{\rm sat}$). NMR spectra in fields
+higher than $H_{\rm c2}$ ($\mu_0H_{\rm c2} \approx 7.5$ T) and temperatures
+$T<T_{\rm N}$ can be described within the model of a spin-modulated phase in
+which the magnetic moments are aligned parallel to the applied field $H$ and
+their values alternate sinusoidally along the magnetic chains. Based on
+theoretical concepts about magnetically frustrated 1D chains, the field
+dependence of the modulation strength of the magnetic structure is deduced from
+our experiments. Relaxation time $T_2$ measurements of the $^{51}$V nuclei show
+that $T_2$ depends on the particular position of the probing $^{51}$V nucleus
+with respect to the magnetic copper moments within the 1D chains: the largest
+$T_2$ value is observed for the vanadium nuclei which are very next to the
+magnetic Cu$^{2+}$ ion with largest ordered magnetic moment. This observation
+is in agreement with the expectation for the spin-modulated magnetic structure.
+The $(H,T)$ magnetic phase diagram of LiCuVO$_4$ is discussed.",1201.6182v1
+2014-03-28,Magnetization scaling in the paramagnetic phase of Mn1-xFexSi solid solutions,"The magnetization field and temperature dependences in the paramagnetic phase
+of Mn1-xFexSi solid solutions with x<0.3 are investigated in the range B<5 T
+and T<60 K. It is found that field dependences of the magnetization
+M(B,T=const) exhibit scaling behavior of the form B\partial M/\partial
+B-M=F(B/(T-Ts)), where Ts denotes an empirically determined temperature of the
+transition into the magnetic phase with fluctuation driven short-range magnetic
+order and F(\c{hi}) is a universal scaling function for given composition. The
+scaling relation allowed concluding that the magnetization in the paramagnetic
+phase of Mn1-xFexSi is represented by the sum of two terms. The first term is
+saturated by the scaling variable \c{hi}=B/(T-Ts), whereas the second is
+linearly dependent on the magnetic field. A simple analytical formula
+describing the magnetization is derived and applied to estimates of the
+parameters characterizing localized magnetic moments in the studied system. The
+obtained data may be qualitatively interpreted assuming magnetic inhomogeneity
+of the paramagnetic phase on the nanoscale.",1403.7332v2
+2014-10-11,Spin wave free spectrum and magnetic field gradient of nanopatterned planes of ferromagnetic cobalt nanoparticles: key properties for magnetic resonance based quantum computing,"We present a study by ferromagnetic resonance at microwave Q band of two
+sheets of cobalt nanoparticles obtained by annealing SiO2 layers implanted with
+cobalt ions. This ex- perimental study is performed as a function of the
+applied magnetic field orientation, tempera- ture, and dose of implanted cobalt
+ions. We demonstrate that each of those magnetic sheet of cobalt nanoparticles
+can be well modelled by a nearly two dimensional ferromagnetic sheet hav- ing a
+reduced effective saturation magnetization, compared to a regular thin film of
+cobalt. The nanoparticles are found superparamagnetic above around 210 K and
+ferromagnetic below this blocking temperature. Magnetostatic calculations show
+that a strong magnetic field gradient of around 0.1 G/nm could be produced by a
+ferromagnetic nanostripe patterned in such magnetic sheet of cobalt
+nanoparticles. Such a strong magnetic field gradient combined with electron
+para- magnetic resonance may be relevant for implementing an intermediate scale
+quantum computer based on arrays of coupled electron spins, as previously
+reported (Eur. Phys. J. B (2014) 87, 183). However, this new approach only
+works if no additional spin decoherence is introduced by the spin waves
+exitations of the ferromagnetic nanostructure. We thus suggest theoretically
+some possible magnetic anisotropy engineering of cobalt nanoparticles that
+could allow to suppress the spin qubit decoherence induced by the unwanted
+collective excitation of their spins.",1410.3005v1
+2015-04-12,Evolution of Kinetic and Magnetic Energy in Intra Cluster Media,"Intra Cluster Media (ICMs) located at galaxy clusters is in the state of hot,
+tenuous, magnetized, and highly ionized X-ray emitting plasmas. This overall
+collisionless, viscous, and conductive magnetohydrodynamic (MHD) turbulence in
+ICM is simulated using hyper and physical magnetic diffusivity. The results
+show that fluctuating random plasma motion amplifies the magnetic field, which
+cascades toward the diffusivity scale passing through the viscous scale. The
+kinetic eddies in the subviscous scale are driven and constrained by the
+magnetic tension which finally gets balanced with the highly damping effect of
+the kinetic eddies. However, the saturated kinetic energy spectrum is deeper
+than that of the incompressible or compressible hydrodynamics fluid. To explain
+this unusual field profile we set up two simultaneous differential equations
+for the kinetic and magnetic energy spectrum using an Eddy Damped Quasi Normal
+Markovianized (EDQNM) approximation. The analytic solution tells us that the
+magnetic energy in addition to the viscous damping effect constrains the plasma
+motion leading to the power spectra: kinetic energy spectrum $E_V^k\sim k^{-3}$
+and corresponding representative magnetic energy spectrum $E_M^k\sim k^{-1/2}$.
+Also the comparison of simulation results with different resolutions and
+magnetic diffusivities implies the role of small scale magnetic energy in
+dynamo.",1504.02940v3
+2016-05-03,Field-induced transition of the magnetic ground state from A-type antiferromagnetic to ferromagnetic order in CsCo2Se2,"We report on the magnetic properties of CsCo$_2$Se$_2$ with ThCr$_2$Si$_2$
+structure, which we have characterized through a series of magnetization and
+neutron diffraction measurements. We find that CsCo$_2$Se2$_2$ undergoes a
+phase transition to an antiferromagnetically ordered state with a N\'eel
+temperature of $T_{\rm N} \approx$ 66 K. The nearest neighbour interactions are
+ferromagnetic as observed by the positive Curie-Weiss temperature of $\Theta
+\approx$ 51.0 K. We find that the magnetic structure of CsCo$_2$Se$_2$ consists
+of ferromagnetic sheets, which are stacked antiferromagnetically along the
+tetragonal \textit{c}-axis, generally referred to as A-type antiferromagnetic
+order. The observed magnitude of the ordered magnetic moment at $T$ = 1.5 K is
+found to be only 0.20(1)$\mu_{\rm Bohr}$/Co. Already in comparably small
+magnetic fields of $\mu_0 H_{MM}$(5K) $\approx$ 0.3 T, we observe a
+metamagnetic transition that can be attributed to spin-rearrangements of
+CsCo$_2$Se$_2$, with the moments fully ferromagnetically saturated in a
+magnetic field of $\mu_0 H_{\rm FM}$(5K) $\approx$ 6.4 T. We discuss the entire
+experimentally deduced magnetic phase diagram for CsCo$_2$Se$_2$ with respect
+to its unconventionally weak magnetic coupling. Our study characterizes
+CsCo$_2$Se$_2$, which is chemically and electronically posed closely to the
+$A_xFe_{2-y}Se_2$ superconductors, as a host of versatile magnetic
+interactions.",1605.01113v1
+2016-09-20,Magnetic anisotropy and the phase diagram of chiral MnSb2O6,"The magnetic phase diagram and low-energy magnon excitations of structurally
+and magnetically chiral MnSb2O6 are reported. The specific heat and the static
+magnetization are investigated in magnetic fields up to 9 and 30 T,
+respectively, while the dynamicmagnetic properties are probed by X-band as well
+as tunable high-frequency electron spin-resonance spectroscopy. Below TN = 11.5
+K, we observe antiferromagnetic resonance modes which imply small but finite
+planar anisotropy showing up in a zero-field splitting of 20 GHz. The data are
+well described by means of an easy-plane two-sublattice model with the
+anisotropy field BA = 0.02 T. The exchange field BE = 13 T is obtained from the
+saturation field derived from the pulsed-field magnetization. A crucial role of
+the small anisotropy for the spin structure is reflected by competing
+antiferromagnetic phases appearing, at T = 2 K, in small magnetic fields at BC1
+$\approx$ 0.5 T and BC2 = 0.9 T. We discuss the results in terms of spin
+reorientation and of small magnetic fields favoring helical spin structure over
+the cycloidal ground state which, at B = 0, is stabilized by the planar
+anisotropy. Above TN, short-range magnetic correlations up to >=60 K and
+magnetic entropy changes well above TN reflect the frustrated triangular
+arrangement of Mn2+ ions in MnSb2O6.",1609.06105v1
+2017-04-13,Extreme Magnetoresistance in Magnetic Rare Earth Monopnictides,"The acute sensitivity of the electrical resistance of certain systems to
+magnetic fields known as extreme magnetoresistance (XMR) has recently been
+explored in a new materials context with topological semimetals. Exemplified by
+WTe$_{2}$ and rare earth monopnictide La(Sb,Bi), these systems tend to be
+non-magnetic, nearly compensated semimetals and represent a platform for large
+magnetoresistance driven by intrinsic electronic structure. Here we explore
+electronic transport in magnetic members of the latter family of semimetals and
+find that XMR is strongly modulated by magnetic order. In particular, CeSb
+exhibits XMR in excess of $1.6 \times 10^{6}$ % at fields of 9 T while the
+magnetoresistance itself is non-monotonic across the various magnetic phases
+and shows a transition from negative magnetoresistance to XMR with field above
+magnetic ordering temperature $T_{N}$. The magnitude of the XMR is larger than
+in other rare earth monopnictides including the non-magnetic members and
+follows an non-saturating power law to fields above 30 T. We show that the
+overall response can be understood as the modulation of conductivity by the Ce
+orbital state and for intermediate temperatures can be characterized by an
+effective medium model. Comparison to the orbitally quenched compound GdBi
+supports the correlation of XMR with the onset of magnetic ordering and
+compensation and highlights the unique combination of orbital inversion and
+type-I magnetic ordering in CeSb in determining its large response. These
+findings suggest a paradigm for magneto-orbital control of XMR and are relevant
+to the understanding of rare earth-based correlated topological materials.",1704.04226v1
+2017-07-30,Effect of magnetic field on the burning of a neutron star,"In this article, we present the effect of a strong magnetic field in the
+burning of a neutron star (NS). We have used relativistic magneto-hydrostatic
+(MHS) conservation equations for studying the PT from nuclear matter (NM) to
+quark matter (QM). We found that the shock-induced phase transition (PT) is
+likely if the density of the star core is more than three times nuclear
+saturation ($\rho_s$) density. The conversion process from NS to quark star
+(QS) is found to be an exothermic process beyond such densities. The burning
+process at the star center most likely starts as a deflagration process.
+However, there can be a small window at lower densities where the process can
+be a detonation one. At small enough infalling matter velocities the resultant
+magnetic field of the QS is lower than that of the NS. However, for a higher
+value of infalling matter velocities, the magnetic field of QM becomes larger.
+Therefore, depending on the initial density fluctuation and on whether the PT
+is a violent one or not the QS could be more magnetic or less magnetic. The PT
+also have a considerable effect on the tilt of the magnetic axis of the star.
+For smaller velocities and densities the magnetic angle are not affected much
+but for higher infalling velocities tilt of the magnetic axis changes suddenly.
+The magnetic field strength and the change in the tilt axis can have a
+significant effect on the observational aspect of the magnetars.",1707.09590v3
+2018-05-11,Anisotropic superconductivity and magnetism in single-crystal RbEuFe$_4$As$_4$,"We investigate the anisotropic superconducting and magnetic properties of
+single-crystal RbEuFe$_4$As$_4$ using magnetotransport and magnetization
+measurements. We determine a magnetic ordering temperature of the Eu-moments of
+$T_m$ = 15 K and a superconducting transition temperature of $T_c$ = 36.8 K.
+The superconducting phase diagram is characterized by high upper critical field
+slopes of -70 kG/K and -42 kG/K for in-plane and out-of-plane fields,
+respectively, and a surprisingly low superconducting anisotropy of $\Gamma$ =
+1.7. Ginzburg-Landau parameters of $\kappa_c \sim 67$ and $\kappa_{ab} \sim
+108$ indicate extreme type-II behavior. These superconducting properties are in
+line with those commonly seen in optimally doped Fe-based superconductors. In
+contrast, Eu-magnetism is quasi-two dimensional as evidenced by highly
+anisotropic in-plane and out-of-plane exchange constants of 0.6 K and $<$ 0.04
+K. A consequence of the quasi-2D nature of the Eu-magnetism are strong magnetic
+fluctuation effects, a large suppression of the magnetic ordering temperature
+as compared to the Curie-Weiss temperature, and a cusp-like anomaly in the
+specific heat devoid of any singularity. Magnetization curves reveal a clear
+magnetic easy-plane anisotropy with in-plane and out-of-plane saturation fields
+of 2 kG and 4 kG.",1805.04216v1
+2018-05-14,Magnetic heating across the cosmological recombination era: Results from 3D MHD simulations,"The origin of cosmic magnetic fields is an unsolved problem and
+magnetogenesis could have occurred in the early Universe. We study the
+evolution of such primordial magnetic fields across the cosmological
+recombination epoch via 3D magnetohydrodynamic numerical simulations. We
+compute the effective or net heating rate of baryons due to decaying magnetic
+fields and its dependence on the magnetic field strength and spectral index. In
+the drag-dominated regime ($z \gtrsim 1500$), prior to recombination, we find
+no real heating is produced. Our simulations allow us to smoothly trace a new
+transition regime ($600 \lesssim z \lesssim 1500$), where magnetic energy
+decays, at first, into the kinetic energy of baryons. A turbulent velocity
+field is built up until it saturates, as the net heating rate rises from a low
+value at recombination to its peak towards the end of the transition regime.
+This is followed by a turbulent decay regime ($z \lesssim 600$) where magnetic
+energy dissipates via turbulent decay of both magnetic and velocity fields
+while net heating remains appreciable and declines slowly. Both the peak of the
+net heating rate and the onset of turbulent decay are delayed significantly
+beyond recombination, by up to 0.5 Myr (until $z\simeq 600-700$), for
+scale-invariant magnetic fields. We provide analytic approximations and present
+numerical results for a range of field strengths and spectral indices,
+illustrating the redshift-dependence of dissipation and net heating rates.
+These can be used to study cosmic microwave background constraints on
+primordial magnetic fields.",1805.05315v1
+2018-06-19,"Magnetic, electronic and transport properties of high-pressure-synthesized chiralmagnets Mn$_{1-x}$Rh$_x$Ge (B20)","We report on structural, magnetic and transport properties of a new set of
+the high-pressuresynthesized compounds Mn$_{1-x}$Rh$x$Ge ($0 \leq x \leq 1$)
+with the chiral magnetic ordering. The magnetic and transport properties depend
+substantially on the concentration of rhodium (x) and the pressure. The
+saturation magnetic moment corresponds to a known high-spin value for pristine
+MnGe (x = 0) and decreases almost linearly with increasing concentration $x$.
+In addition, XMCD spectra taken at 10 K and 2 T indicate magnetic polarization
+of the Rh 4d electron states and Ge $4p$ states, which decreases with $x$, too.
+In rhodium rich compounds ($x \geq 0.5$) the temperature of the magnetic
+ordering increases significantly with pressure, whereas in manganese rich
+compounds ($x < 0.5$) the temperature decreases. Three different tendencies are
+also found for several structural and transport properties. In the intermediate
+range ($0.3 \leq x \leq 0.7$) samples are semiconducting in the paramagnetic
+phase, but become metallic in the magnetically ordered state. We carried out ab
+initio density-functional calculations of Mn$_{1-x}$Rh$_x$Ge at various
+concentrations $x$ and traced the evolution of electronic and magnetic
+properties. The calculation results are in good agreement with the measured
+magnetic moments and qualitatively explain the observed trends in transport
+properties.",1806.07165v1
+2018-09-20,Three-dimensional kinetic simulations of relativistic magnetostatic equilibria,"We present the results of three-dimensional kinetic particle-in-cell (PIC)
+simulations of isotropic periodic relativistically magnetized pair-plasma
+equilibria known as the ABC fields. We performed several simulations for
+initial wavenumbers k_ini = 2 or k_ini = 4, different efficiencies of radiative
+cooling (including radiation reaction from synchrotron and inverse Compton
+processes), and different mean magnetization values. These equilibria evolve by
+means of ideal coalescence instability, the saturation of which generates ab
+initio localized kinetically-thin current layers -- sites of magnetic
+reconnection and non-thermal particle acceleration -- eventually relaxing to a
+state of lower magnetic energy at conserved total magnetic helicity. We
+demonstrate that magnetic relaxation involves in addition localized collapses
+of magnetic minima and bulk mergers of current layer pairs, which represents a
+novel scenario of spontaneous magnetic dissipation with application to the
+rapid gamma-ray flares of blazars and of the Crab Nebula. Particle acceleration
+under strong radiative losses leads to formation of power-law indices N(gamma)
+~ gamma^(-p) up to p ~= -2.3 at mean hot magnetization values of <sigma_hot> ~
+6. Individual energetic particles can be accelerated within one light-crossing
+time by electric fields that are largely perpendicular to the local magnetic
+fields. The energetic particles are highly anisotropic due to the kinetic
+beaming effect, implying complex patterns of rapid variability. A significant
+fraction of the initial total energy can be radiated away in the overall
+process of magnetoluminescence.",1809.07773v1
+2018-10-02,Building traps for skyrmions by the incorporation of magnetic defects into nanomagnets: pinning and scattering traps by magnetic properties engineering,"In this work we have used micromagnetic simulations to report four ways to
+build traps for magnetic skyrmions. Magnetic defects have been modeled as local
+variations in the material parameters, such as the exchange stiffness,
+saturation magnetization, magnetocrystalline anisotropy and
+Dzyaloshinskii-Moriya constant. We observe both pinning (potential well) and
+scattering (potential barrier) traps when tuning either a local increase or a
+local reduction for each one of these magnetic properties. It is found that the
+skyrmion-defect aspect ratio is a crucial parameter to build traps for
+skyrmions. In particular, the efficiency of the trap is compromised if the
+defect size is smaller than the skyrmion size, because they interact weakly. On
+the other hand, if the defect size is larger than the skyrmion diameter, the
+skyrmion-defect interaction becomes evident. Thus, the strength of the
+skyrmion-defect interaction can be tuned by the modification of the magnetic
+properties within a region with suitable size. Furthermore, the basic physics
+behind the mechanisms for pinning and for scattering is discussed. In
+particular, we discover that skyrmions move towards the magnetic region which
+tends to maximize its diameter; it enables the magnetic system to minimize its
+energy. Thus, we are able to explain why skyrmions are either attracted or
+repelled by a region with modified magnetic properties. Results here presented
+are of utmost significance for the development and realization of future
+spintronic devices, in which skyrmions will work as information carriers.",1810.03754v2
+2019-01-16,"Magnetic properties of double perovskite $Ln_2$CoIrO$_6$ ($Ln$ = Eu, Tb, Ho): hetero-tri-spin $3d$-$5d$-$4f$ systems","The field of double perovskites is now advancing to three magnetic elements
+on the A, B and B$'$ sites. A series of iridium-based double perovskite
+compounds, $Ln_2$CoIrO$_6$ ($Ln$ = Eu, Tb, Ho) with three magnetic elements
+were synthesized as polycrystalline samples. The compounds crystalize in
+monoclinic structures with the space group $P2_1/n$. Magnetic properties of
+these hetero-tri-spin $3d$-$5d$-$4f$ systems were studied by magnetic
+susceptibility and field dependent magnetization in both DC and pulsed magnetic
+fields. All these compounds show ferrimagnetic transitions at temperatures
+$T_C$ above 100 K, which are attributable to antiferromagnetic coupling between
+Co$^{2+}$ and Ir$^{4+}$ spins. For Eu$_2$CoIrO$_6$, the magnetic properties are
+similar to those of La$_2$CoIrO$_6$. The Eu$^{3+}$ spins show Van Vleck
+paramagnetism that don't significantly interact with transition-metal cations.
+By contrast, Tb$_2$CoIrO$_6$ and Ho$_2$CoIrO$_6$ reveal a second transition to
+antiferromagnetic order below a lower temperature $T_N$. The
+temperature-induced ferrimagnetic-to-antiferromagnetic phase transition might
+be explained by a spin-reorientation transition. Moreover, a
+magnetic-field-induced spin-flop transition with a small hysteresis was
+observed below $T_N$ in these two compounds. The magnetic moment of all three
+compounds do not saturate up to 60 T at low temperatures. Moderate
+magnetocaloric effect was also observed in all three compounds. Our results
+should motivate further investigation of the spin configuration on single
+crystals of these iridium-based double perovskites.",1901.05412v1
+2019-05-14,Versatile Hall magnetometer with variable sensitivity assembly for characterization of the magnetic properties of nanoparticles,"A Hall magnetometer with variable sensitivity is constructed to measure the
+magnetic properties of magnetic nanoparticles manufactured by different
+methods. This novel magnetometer can also be used to measure bulk materials and
+samples in liquids. The magnetometer is constructed with two commercial
+Hall-effect sensors in an acrylic structure, which serves as the support for a
+micrometer and the circuit board with the sensors. For operation, the
+magnetometer it acquires a complete magnetization curve in a few minutes. If
+has a magnetic moment sensitivity of 1.3*10-9 Am2 to sensitivity of 493 mV/mT,
+the sensitivity can be adjustable in the range of 10 to 493 mV/mT. Its
+performance is tested with magnetic nanoparticles. As an application example,
+we estimate the mean diameter of the nanoparticles using the magnetic curves.
+The results are compared with those obtained by other techniques, such as
+transmission electron microscopy (TEM), X-ray diffraction (XRD) and dynamic
+light scattering (DLS). The magnetization results are also compared with those
+obtained by independent commercial magnetometers, which reveals errors of
+approximately 0.31 Am2/kg (i.e., 0.6%) in the saturation region.",1905.05741v2
+2019-10-15,Irregularly Shaped γ'-Fe4N Nanoparticles for Hyperthermia Treatment and T2 Contrast-Enhanced Magnetic Resonance Imaging with Minimum Dose,"Magnetic nanoparticles (MNPs) have been extensively used in drug/gene
+delivery, hyperthermia therapy, magnetic particle imaging (MPI), magnetic
+resonance imaging (MRI), magnetic bioassays, etc. With proper surface chemical
+modifications, physicochemically stable and non-toxic MNPs are emerging
+contrast agents and tracers for in vivo MRI and MPI applications. Herein, we
+report the high magnetic moment, irregularly shaped {\gamma}'-Fe4N
+nanoparticles for enhanced hyperthermia therapy and T2 contrast agent for MRI
+application. The static and dynamic magnetic properties of {\gamma}'-Fe4N
+nanoparticles are characterized by vibrating sample magnetometer (VSM) and
+magnetic particle spectroscopy (MPS) systems, respectively. Compared to the
+{\gamma}-Fe2O3 nanoparticles, {\gamma}'-Fe4N show at least 3 times higher
+saturation magnetization (in emu/g), which, as a result, gives rise to the
+stronger dynamic magnetic responses as proved in the MPS measurement results.
+In addition, {\gamma}'-Fe4N nanoparticles are functionalized with oleic acid
+layer by a wet mechanical milling process, the morphologies of as-milled
+nanoparticles are characterized by transmission electron microscopy (TEM),
+dynamic light scattering (DLS) and nanoparticle tracking analyzer (NTA). We
+report that with proper surface chemical modification and tuning on
+morphologies, {\gamma}'-Fe4N nanoparticles could be used as tiny heating
+sources for hyperthermia and contrast agents for MRI applications with minimum
+dose.",1910.06842v1
+2020-01-15,Meson masses in external magnetic fields with HISQ fermions,"We studied the temporal correlation function of mesons in the pseudo-scalar
+channel in (2+1)-flavor QCD in the presence of external magnetic fields at zero
+temperature. The simulations were performed on $32^3 \times 96$ lattices using
+the Highly Improved Staggered Quarks (HISQ) action with $m_{\pi} \approx $ 230
+MeV. The strength of magnetic fields $|eB|$ ranges from 0 to around 3.3 GeV$^2$
+($\sim 60 m_\pi^2$). We found that the masses of neutral pseudo-scalar
+particles, e.g. neutral pion and kaon, monotonouslly decrease as the magnetic
+field grows and then saturate at a nonzero value. It is observed that heavier
+neutral pseudo-scalars are less affected by magnetic fields. Moreover, we found
+a non-monotonous behavior of charged pion and kaon mass in magnetic field for
+the first time. In the case of small magnetic field (0 $\leq~|eB| \lesssim$ 0.3
+GeV$^2~\sim 6m_\pi^2$ ) the mass of charged pseudo-scalar grows with magnetic
+field and can be well described by the Lowest Landau Level approximation, while
+for $|eB|$ larger than 0.3 GeV$^2$ the mass starts to decrease. The possible
+connection between $|eB|$ dependences of neutral pion mass and the decreasing
+behavior of pseudo-critical temperature in magnetic field is discussed. Due to
+the nonzero value of neutral pion mass our simulation indicates that the
+superconducting phase of QCD does not exist in the current window of magnetic
+field.",2001.05322v1
+2020-02-18,Magnetic and all-optical switching properties of amorphous Tb$_x$Co$_{100-x}$ alloys,"Amorphous Tb$_{x}$Co$_{100-x}$ magnetic alloys exhibit a list of intriguing
+properties, such as perpendicular magnetic anisotropy, high magneto-optical
+activity and magnetization switching using ultrashort optical pulses. Varying
+the Tb:Co ratio in these alloys allows for tuning properties such as the
+saturation magnetic moment, coercive field and the performance of the
+light-induced magnetization switching. In this work, we investigate the
+magnetic, optical and magneto-optical properties of various
+Tb$_{x}$Co$_{100-x}$ thin film alloy compositions. We report on the effect the
+choice of different seeding layers has on the structural and magnetic
+properties of Tb$_{x}$Co$_{100-x}$ layers. We also demonstrate that for a range
+of alloys, deposited on fused silica substrates, with Tb content of 24-30
+at.$\%$, helicity dependent all-optical switching of magnetization can be
+achieved, albeit in a multi-shot framework. We explain this property to arise
+from the helicity-dependent laser induced magnetization on the Co sublattice
+due to the inverse Faraday effect. Our study provides an insight into material
+aspects for future potential hybrid magneto-plasmonic TbCo-based architectures.",2002.07544v3
+2020-07-06,Ferrimagnetism in EuFe4As12 revealed by 153Eu NMR and 75As NQR measurements,"Filled skutterudite compound EuFe$_4$As$_{12}$ shows the highest magnetic
+ordering temperature of $T_{\rm C}$ = 154 K among Eu-based skutterudite
+compounds, but its magnetic ground state has not been determined yet. Here, we
+performed $^{153}$Eu nuclear magnetic resonance (NMR) and $^{75}$As nuclear
+quadrupole resonance (NQR) measurements on EuFe$_4$As$_{12}$ to reveal its
+magnetic ground state as well as the physical properties from a microscopic
+point of view. From the temperature and magnetic field dependence of $^{153}$Eu
+NMR spectrum in the magnetically ordered state, we found that the Eu ions are
+in Eu$^{2+}$ state with a nearly 7 $\mu_{\rm B}$ corresponding to $S$ = 7/2
+spins. Combined with the magnetization measurements which show the reduced
+saturation moments of 4.5 $\mu_{\rm B}$/f.u., we determined the ground magnetic
+structure in EuFe$_4$As$_{12}$ to be ferrimagnetic where the Eu$^{2+}$ 4$f$ and
+the Fe 3$d$ ordered moments are ferromagnetically aligned in each sublattice
+but the moments between the sublattices are antiferromagnetically aligned. We
+also found the local distortion at the Eu site from the cubic symmetry in the
+magnetically ordered state. The relationship between the rattling motion of Eu
+atoms and the local symmetry of the Eu ions is discussed. From the $^{75}$As
+NQR nuclear spin-lattice relaxation time measurements as well as $^{153}$Eu NMR
+measurements, we found that the 4$f$ electrons of the Eu ions are well
+described by the local moment picture in both the magnetic and paramagnetic
+metallic states.",2007.02983v1
+2020-10-07,Magnetostriction in elastomers with mixtures of magnetically hard and soft microparticles: effects of non-linear magnetization and matrix rigidity,"In this contribution a magnetoactive elastomer (MAE) of mixed content, i.e.,
+a polymer matrix filled with a mixture of magnetically soft and magnetically
+hard spherical particles, is considered. The object we focus at is an
+elementary unit of this composite, for which we take a set consisting of a
+permanent spherical micromagnet surrounded by an elastomer layer filled with
+magnetically soft microparticles. We present a comparative treatment of this
+unit from two essentially different viewpoints. The first one is a
+coarse-grained molecular dynamics simulation model, which presents the
+composite as a bead-spring assembly and is able to deliver information of all
+the microstructural changes of the assembly. The second approach is entirely
+based on the continuum magnetomechanical description of the system, whose
+direct yield is the macroscopic field-induced response of the MAE to external
+field, as this model ignores all the microstructural details of the
+magnetization process. We find that, differing in certain details, both
+frameworks are coherent in predicting that a unit comprising magnetically soft
+and hard particles may display a non-trivial re-entrant
+(prolate/oblate/prolate) axial deformation under variation of the applied field
+strength.
+  The flexibility of the proposed combination of the two complementary
+frameworks enables us to look deeper into the manifestation of the magnetic
+response: with respect to the magnetically soft particles, we compare the
+linear regime of magnetization to that with saturation, which we describe by
+the Fr\""{o}hlich-Kennelly approximation; with respect to the polymer matrix, we
+analyze the dependence of the re-rentrant deformation on its rigidity.",2010.03684v1
+2021-05-18,Asteroid Magnetization from the Early Solar Wind,"Magnetic fields provide an important probe of the thermal, material, and
+structural history of planetary and sub-planetary bodies. Core dynamos are a
+potential source of magnetic fields for differentiated bodies, but evidence of
+magnetization in undifferentiated bodies requires a different mechanism. Here
+we study the amplified field provided by the stellar wind to an initially
+unmagnetized body using analytic theory and numerical simulations, employing
+the resistive MHD AstroBEAR adaptive mesh refinement (AMR) multiphysics code.
+We obtain a broadly applicable scaling relation for the peak magnetization
+achieved once a wind advects, piles-up, and drapes a body with magnetic field,
+reaching a quasi-steady state. We find that the dayside magnetic field for a
+sufficiently conductive body saturates when it balances the sum of incoming
+solar wind ram, magnetic, and thermal pressures. Stronger amplification results
+from pileup by denser and faster winds. Careful quantification of numerical
+diffusivity is required for accurately interpreting the peak magnetic field
+strength from simulations, and corroborating with theory. As specifically
+applied to the Solar System, we find that early solar wind-induced field
+amplification is a viable source of magnetization for observed paleointensities
+in meteorites from some undifferentiated bodies. This mechanism may also be
+applicable to other Solar System bodies, including metal-rich bodies to be
+visited in future space missions such as the asteroid (16) Psyche.",2105.08852v3
+2021-05-24,Magneto-rotational instability in magnetically polarized discs,"The magneto-rotational instability (MRI) is the most likely mechanism for
+transportation of angular momentum and dissipation of energy within hot,
+ionized accretion discs. This instability is produced through the interactions
+of a differentially rotating plasma with an embedded magnetic field. Like all
+substances in nature, the plasma in an accretion disc has the potential to
+become magnetically polarized when it interacts with the magnetic field. In
+this paper, we study the effect of this magnetic susceptibility, parameterized
+by $\chi_m$, on the MRI, specifically within the context of black hole
+accretion. We find from a linear analysis within the Newtonian limit that the
+minimum wavelength of the first unstable mode and the wavelength of the fastest
+growing mode are shorter in paramagnetic ($\chi_m>0$) than in diamagnetic
+($\chi_m<0$) discs, all other parameters being equal. Furthermore, the
+magnetization parameter (ratio of gas to magnetic pressure) in the saturated
+state should be smaller when the magnetic susceptibility is positive than when
+it is negative. We confirm this latter prediction through a set of numerical
+simulations of magnetically polarized black hole accretion discs. We
+additionally find that the vertically integrated stress and mass accretion rate
+are somewhat larger when the disc is paramagnetic than when it is diamagnetic.
+If astrophysical discs are able to become magnetically polarized to any
+significant degree, then our results would be relevant to properly interpreting
+observations.",2105.11329v1
+2021-12-15,Effect of magnetocrystalline anisotropy on magnetocaloric properties of AlFe$_{2}$B$_{2}$ compound,"It is well known that the temperature dependence of the effective
+magnetocrystalline anisotropy energy obeys the $l(l+1)/2$ power law of
+magnetization in the Callen-Callen theory. Therefore, according to the
+Callen-Callen theory, the magnetocrystalline anisotropy energy is assumed to be
+zero at the critical temperature where the magnetization is approximately zero.
+This study estimates the temperature dependence of the magnetocrystalline
+anisotropy energy by integrating the magnetization versus magnetic field
+($M$--$H$) curves, and found that the magnetocrystalline anisotropy is still
+finite even above the Curie temperature in the uniaxial anisotropy, whereas
+this does not appear in the cubic anisotropy case. The origin is the fast
+reduction of the anisotropy field, which is the magnetic field required to
+saturate the magnetization along the hard axis, in the case of cubic
+anisotropy. Therefore, the magnetization anisotropy and anisotropic magnetic
+susceptibility, those are the key factors of magnetic anisotropy, could not be
+established in the case of cubic anisotropy. In addition, the effect of
+magnetocrystalline anisotropy on magnetocaloric properties, as the difference
+between the entropy change curves of AlFe$_{2}$B$_{2}$ appears above the Curie
+temperature, which is in good agreement with a previous experimental study.
+This is proof of magnetic anisotropy at slightly above Curie temperature.",2112.08154v1
+2023-02-07,Masterthesis: Ab Initio Magnetic Properties of Rare-Earth Lean Nd-based Hard Magnets,"Due to the resource criticality of rare-earths (RE), an alternative to the
+well-known Nd$_2$Fe$_{14}$B magnets with a lower amount of critical elements is
+required. In this work, density functional theory (DFT) calculations to
+investigate the influence of partial Nd substitution with more abundant
+elements (X: Y and Ce) in ThMn$_{12}$-type (Nd,X)Fe$_{11}$Ti compounds were
+performed. In order to have a systematic understanding, the intrinsic magnetic
+properties such as the saturation magnetization $M_S$, Curie temperature $T_C$
+and magnetocrystalline anisotropy energy, are screened starting from binaries
+RFe$_{12}$ (R: Y, Ce and Nd), and only considering the spin magnetic
+contribution in case of the $f$ electrons. Ti is considered for the
+thermodynamic stabilization and different concentrations of Ti are taken into
+account for ternaries RFe$_{12-y}$Ti$_y$ and quaternaries
+(Nd,X)Fe$_{12-y}$Ti$_y$ (0.5$\le$ $y$ $\le$1). In addition, the effect of
+nitrogenation is examined for each considered compound. In case of
+(Nd,Y)Fe$_{11}$Ti, $|BH|$$_{max}$ is found to be 384 kJ/m$^3$ and $T_C$ is
+calculated to be 595 K. Similarly, $|BH|$$_{max}$ and $T_C$ are calculated to
+be 365 kJ/m$^3$ and 593 K for (Nd,Ce)Fe$_{11}$Ti magnet, respectively. Both 50
+% Nd-lean magnets exhibit higher $|BH|$$_{max}$ compared to Sm$_2$Co$_{17}$ and
+$T_C$ than Nd$_2$Fe$_{14}$B. For both cases, the theoretical magnetic hardness
+factor $\kappa$ is calculated to be 1.20, which qualifies them as good
+candidates for RE-lean permanent magnets.",2302.03417v1
+2023-02-21,Exploring the magnetic properties of individual barcode nanowires using wide-field diamond microscopy,"Barcode magnetic nanowires typically comprise a multilayer magnetic structure
+in a single body with more than one segment type. Interestingly, owing to
+selective functionalization and novel interactions between the layers, barcode
+magnetic nanowires have attracted significant attention, particularly in the
+field of bioengineering. However, an analysis of their magnetic properties at
+the individual nanowire level remains challenging. With this background,
+herein, we investigated the characterization of magnetic nanowires at room
+temperature under ambient conditions based on magnetic images obtained via
+wide-field quantum microscopy with nitrogen-vacancy centers in diamond.
+Consequently, we could extract critical magnetic properties, such as the
+saturation magnetization and coercivity, of single nanowires by comparing the
+experimental results with those of micromagnetic simulations. This study opens
+up the possibility for a versatile characterization method suited to individual
+magnetic nanowires.",2302.10547v1
+2023-12-07,Features of magnetization and spin reorientation in weak ferrimagnets of the YFe$_{1-x}$Cr$_x$O$_3$ type,"A brief critical review is given of the 50-year history of experimental and
+theoretical studies of the magnetic properties of a new promising class of weak
+ferrimagnets such as RFe$_{1-x}$Cr$_x$O$_3$ with a non-magnetic R-ion (R = La ,
+Y, Lu), i.e. systems with competing signs of the Dzyaloshinsky vectors Fe-Fe,
+Cr-Cr and Fe-Cr. The spin Hamiltonian of the system is considered taking into
+account isotropic exchange, antisymmetric Dzyaloshinsky-Moriya exchange, and
+second- and fourth-order single-ion anisotropy. Within the framework of the
+molecular field approximation, calculations were made of the Neel temperatures,
+the average magnetic moments of $3d$ ions, total and partial magnetizations,
+and effective anisotropy constants. The existence in the model system
+YFe$_{1-x}$Cr$_x$O$_3$ of two regions of negative magnetization $0.25 \leq
+x\leq 0.5$ and $x\approx 0.8$ with the corresponding magnetization reversal
+points reaching room temperature at $x\approx 0.45$. The phenomenon of spin
+reorientation observed for single-crystal samples in a wide range of
+concentrations is explained by a sharp decrease in the contribution of
+antisymmetric exchange to magnetic anisotropy with increasing deviation from
+the parent compositions and competition between the contributions of single-ion
+anisotropy of Fe and Cr ions. It has been suggested that the spatial
+orientation of the Neel ${\bf G}$ vector and the $G_{xyz}$ configuration are
+the reason for the small value of saturation magnetization observed
+experimentally for compositions inside or near the region of negative
+magnetization.",2312.04381v2
+2024-03-01,Spin current control of magnetism,"Exploring novel strategies to manipulate the order parameter of magnetic
+materials by electrical means is of great importance, not only for advancing
+our understanding of fundamental magnetism, but also for unlocking potential
+practical applications. A well-established concept to date uses gate voltages
+to control magnetic properties, such as saturation magnetization, magnetic
+anisotropies, coercive field, Curie temperature and Gilbert damping, by
+modulating the charge carrier population within a capacitor structure. Note
+that the induced carriers are non-spin-polarized, so the control via the
+electric-field is independent of the direction of the magnetization. Here, we
+show that the magnetocrystalline anisotropy (MCA) of ultrathin Fe films can be
+reversibly modified by a spin current generated in Pt by the spin Hall effect.
+The effect decreases with increasing Fe thickness, indicating that the origin
+of the modification can be traced back to the interface. Uniquely, the change
+in MCA due to the spin current depends not only on the polarity of the charge
+current but also on the direction of magnetization, i.e. the change in MCA has
+opposite sign when the direction of magnetization is reversed. The control of
+magnetism by the spin current results from the modified exchange splitting of
+majority- and minority-spin bands, and differs significantly from the
+manipulation by gate voltages via a capacitor structure, providing a
+functionality that was previously unavailable and could be useful in advanced
+spintronic devices.",2403.00709v1
+2002-10-18,Nonlinear Magnetic Diffusion and Magnetic Helicity Transport in Galactic Dynamos,"We have extended our previous mean-field galactic dynamo model which included
+algebraic and dynamic alpha nonlinearities (Kleeorin et al., A&A, v. 387, 453,
+2002), to include also a quenching of turbulent diffusivity. We readily obtain
+equilibrium states for the large-scale magnetic field in the local disc dynamo
+model, and these fields have strengths that are comparable to the equipartition
+field strength. We find that the algebraic nonlinearity alone (i.e. quenching
+of both the alpha effect and turbulent magnetic diffusion) cannot saturate the
+growth of the mean magnetic field; only the combined effect of algebraic and
+dynamic nonlinearities can limit the growth of the mean magnetic field.
+However, in contrast to our earlier work without quenching of the turbulent
+diffusivity, we cannot now find satisfactory solutions in the no-z
+approximation to the axisymmetric galactic dynamo problem.",0210430v1
+2005-04-15,On the Sr I 4607 A Hanle depolarization signals in the quiet Sun,"The Hanle depolarization signals of Sr 4607 A have been used to estimate the
+unsigned magnetic flux and magnetic energy existing in the quiet Sun
+photosphere. However, the Sr 4607 A Hanle signals are not sensitive to the
+unsigned flux and energy. They only bear information on the fraction of
+photosphere occupied by magnetic field strengths smaller than the Hanle
+saturation, which do not contribute to the unsigned flux and energy. We deduce
+an approximate expression for the relationship between magnetic fill factor and
+Hanle signal. When applied to existing Hanle depolarization measurements, it
+indicates that only 40% of the quiet Sun is filled by magnetic fields with a
+strength smaller than 60 G. The remaining 60% of the surface has field
+strengths above this limit. Such constraint will be needed to determine the
+distribution of magnetic field strengths existing in the quiet Sun.",0504339v1
+2005-07-16,Magnetohydrodynamics in full general relativity: Formulation and tests,"A new implementation for magnetohydrodynamics (MHD) simulations in full
+general relativity (involving dynamical spacetimes) is presented. In our
+implementation, Einstein's evolution equations are evolved by a BSSN formalism,
+MHD equations by a high-resolution central scheme, and induction equation by a
+constraint transport method. We perform numerical simulations for standard test
+problems in relativistic MHD, including special relativistic magnetized shocks,
+general relativistic magnetized Bondi flow in stationary spacetime, and a
+longterm evolution for self-gravitating system composed of a neutron star and a
+magnetized disk in full general relativity. In the final test, we illustrate
+that our implementation can follow winding-up of the magnetic field lines of
+magnetized and differentially rotating accretion disks around a compact object
+until saturation, after which magnetically driven wind and angular momentum
+transport inside the disk turn on.",0507383v1
+1996-11-19,Magnetic phase diagram and transport properties of FeGe_2,"We have used resistivity measurements to study the magnetic phase diagram of
+the itinerant antiferromagnet FeGe_2 in the temperature range from 0.3->300 K
+in magnetic fields up to 16 T. In contrast to theoretical predictions, the
+incommensurate spin density wave phase is found to be stable at least up to 16
+T, with an estimated critical field \mu _0H_c of ~ 30 T. We have also studied
+the low temperature magnetoresistance in the [100], [110], and [001]
+directions. The transverse magnetoresistance is well described by a power law
+for magnetic fields above 1 T with no saturation observed at high fields. We
+discuss our results in terms of the magnetic structure and the calculated
+electronic bandstructure of FeGe_2. We have also observed, for the first time
+in this compound, Shubnikov-de Haas oscillations in the transverse
+magnetoresistance with a frequency of 190 +- 10 T for a magnetic field along
+[001].",9611144v1
+2000-02-17,"Silence of magnetic layers to magnetoresistive process and electronic separation at low temperatures in (La, Sm)Mn$_2$Ge$_2$","A closer look at the temperature (T) dependence of magnetoresistance (MR) of
+two polycrystalline magnetic compounds, LaMn$_2$Ge$_2$ and SmMn$_2$Ge$_2$,
+previously reported by us, is made. A common feature for both these compounds
+is that the low temperature MR is positive (say, below, 30 K) in spite of the
+fact that both are ferromagnetic at such low temperatures; in addition, MR as a
+function of magnetic field (H) does not track magnetization (M) in the sense
+that M saturates at low fields, while MR varies linearly with H. These
+observations suggest that the magnetic layers interestingly do not dominate low
+temperature magnetotransport process. Interestingly enough, as the T is
+increased, say around 100 K, these magnetic layers dominate MR process as
+evidenced by the tracking of M and MR in SmMn$_2$Ge$_2$. These results tempts
+us to propose that there is an unusual ""electronic separation"" for MR process
+as the T is lowered in this class of compounds.",0002275v1
+2002-10-14,Magnetic Superstructure in the Two-Dimensional Quantum Antiferromagnet SrCu2(BO3)2,"We report the observation of magnetic superstructure in a magnetization
+plateau state of SrCu2(BO3)2, a frustrated quasi-two-dimensional quantum spin
+system. The Cu and B nuclear magnetic resonance (NMR) spectra at 35 mllikelvin
+indicate an apparently discontinuous phase transition from uniform
+magnetization to a modulated superstructure near 27 tesla, above which a
+magnetization plateau at 1/8 of the full saturation has been observed.
+Comparison of the Cu NMR spectrum and the theoretical analysis of a Heisenberg
+spin model demonstrates the crystallization of itinerant triplets in the
+plateau phase within a large rhomboid unit cell (16 spins per layer) showing
+oscillations of the spin polarization. Thus we are now in possession of an
+interesting model system to study a localization transition of strongly
+interacting quantum particles.",0210294v1
+2003-05-18,A disordered RKKY lattice mean field theory for ferromagnetism in diluted magnetic semiconductors,"We develop a lattice mean field theory for ferromagnetic ordering in diluted
+magnetic semiconductors by taking into account the spatial fluctuations
+associated with random disorder in the magnetic impurity locations and the
+finite mean free path associated with low carrier mobilities. Assuming a
+carrier-mediated indirect RKKY exchange interaction among the magnetic
+impurities, we find substantial deviation from the extensively used continuum
+Zener model Weiss mean-field predictions. Our theory allows accurate analytic
+predictions for Tc, and provides simple explanations for a number of observed
+anomalies including the non-Brillouin function magnetization curves, the
+suppressed low-temperature magnetization saturation, and the dependence of Tc
+on conductivity.",0305413v1
+2003-12-18,Current induced magnetization dynamics in current perpendicular to the plane spin valves,"We observe magnetization dynamics induced by spin momentum transfer in the
+noise spectra of current perpendicular to the plane giant magnetoresistance
+spin valves. The dynamics are observable only for those combinations of current
+direction and magnetic configuration in which spin transfer acts to reorient
+the free layer magnetization away from the direction set by the net magnetic
+field. Detailed measurements as a function of magnetic configuration reveal an
+evolution of the noise spectra, going from a spectrum with a well-defined noise
+peak when the free layer is roughly collinear with the pinned layer to a
+spectrum dominated by 1/f noise when the free layer is in an orthogonal
+configuration. Finally, the amplitude of the corresponding resistance noise
+increases rapidly with increasing current until it saturates at a value that is
+a substantial fraction of the magnetoresistance between parallel and
+antiparallel states.",0312504v2
+2004-04-18,Magnetization process of spin ice in a [111] magnetic field,"Spin ice in a magnetic field in the [111] direction displays two
+magnetization plateaux, one at saturation and an intermediate one with finite
+entropy. We study the crossovers between the different regimes from a point of
+view of (entropically) interacting defects. We develop an analytical theory for
+the nearest-neighbor spin ice model, which covers most of the magnetization
+curve. We find that the entropy is non-monotonic, exhibiting a giant spike
+between the two plateaux. This regime is described by a monomer-dimer model
+with tunable fugacities. At low fields, we develop an RG treatment for the
+extended string defects, and we compare our results to extensive Monte Carlo
+simulations. We address the implications of our results for cooling by
+adiabatic (de)magnetization.",0404417v2
+2004-08-06,Relevance of a magnetic moment distribution and scaling law methods to study the magnetic behavior of antiferromagnetic nanoparticles,"In antiferromagnetic nanoparticles magnetization the linear component,
+$\chi_{AF}$H superposed to the saturation one usually complicates the fit of
+experimental data. We present a method based on scaling laws to determine the
+variation of $\chi_{AF}$ with temperature and to find the temperature
+dependence of the average magnetic moment $<\mu>$, without any assumption on
+both the magnetization dependence on field or the moment distribution function,
+whose relevance can also be estimated. We have applied this method to ferritin
+and found that $<\mu>$ decreases with increasing temperature and that a
+distribution function cannot be ignored. The fit with Langevin magnetization
+law and lognormal moment distribution functions yielded parameters close to
+those estimated with the scaling method. We also show that in general if the
+distribution is ignored, and a single particle moment $\mu_p$ is used, $\mu_p$
+presents an artificial systematic increase with temperature. This calls the
+attention to the necessity of evaluating the effect of a size distribution
+before concluding about the physical nature of the parameters variation.",0408134v1
+2004-12-22,Ground state and low-lying excitations of the spin-1/2 XXZ model on the kagome lattice at magnetization 1/3,"We study the ground state and low-lying excitations of the S=1/2 XXZ
+antiferromagnet on the kagome lattice at magnetization one third of the
+saturation. An exponential number of non-magnetic states is found below a
+magnetic gap. The non-magnetic excitations also have a gap above the ground
+state, but it is much smaller than the magnetic gap. This ground state
+corresponds to an ordered pattern with resonances in one third of the hexagons.
+The spin-spin correlation function is short ranged, but there is long-range
+order of valence-bond crystal type.",0412608v1
+2005-07-05,Suppressed magnetization in La$_{0.7}$Ca$_{0.3}$MnO$_3$/YBa$_2$Cu$_3$O$_{7-δ}$ superlattices,"We studied the magnetic properties of La$_{0.7}$Ca$_{0.3}$MnO$_3$ /
+YBa$_2$Cu$_3$O$_{7-\delta}$ superlattices. Magnetometry showed that with
+increasing YBa$_2$Cu$_3$O$_{7-\delta}$ layer thickness the saturation
+magnetization per La$_{0.7}$Ca$_{0.3}$MnO$_3$ layer decreases. From polarized
+neutron reflectometry we determined that this magnetization reduction is due to
+an inhomogenous magnetization depth profile arising from the suppression of
+magnetization near the La$_{0.7}$Ca$_{0.3}$MnO$_3$ /
+YBa$_2$Cu$_3$O$_{7-\delta}$ interface. Electron energy loss spectroscopy
+indicates an increased 3d band occupation of the Mn atoms in the
+La$_{0.7}$Ca$_{0.3}$MnO$_3$ layers at the interface. Thus, the suppression of
+ferromagnetic order at the La$_{0.7}$Ca$_{0.3}$MnO$_3$ /
+YBa$_2$Cu$_3$O$_{7-\delta}$ interface is most likely due to charge transfer
+between the two materials.",0507123v2
+2005-09-07,Specific heat of the $S = 1$ spin-dimer antiferromagnet Ba$_3$Mn$_2$O$_8$ in high magnetic fields,"We have measured the specific heat of the coupled spin-dimer antiferromagnet
+Ba$_3$Mn$_2$O$_8$ to 50 mK in temperature and to 29 T in the magnetic field.
+The experiment extends to the midpoint of the field region (25.9 T $\leq H
+\leq$ 32.3 T) of the magnetization plateau at 1/2 of the saturation
+magnetization, and reveals the presence of three ordered phases in the field
+region between that of the magnetization plateau and the low-field spin-liquid
+region. The exponent of the phase boundary with the thermally disordered region
+is smaller than the theoretical value based on the Bose-Einstein condensation
+of spin triplets. At zero field and 29 T, the specific-heat data show gapped
+behaviors characteristic of spin liquids. The zero-field data indicate that the
+gapped triplet excitations form two levels whose energies differ by nearly a
+factor of two. At least the lower level is well localized. The data at 29 T
+reveal that the low-lying excitations at the magnetization plateau are weakly
+delocalized.",0509169v2
+2006-03-07,Magnetization plateau in the S=1/2 spin ladder with alternating rung exchange,"We have studied the ground state phase diagram of a spin ladder with
+alternating rung exchange $J^{n}_{\perp} = J_{\perp}[1 + (-1)^{n} \delta ]$ in
+a magnetic filed, in the limit where the rung coupling is dominant. In this
+limit the model is mapped onto an $XXZ$ Heisenberg chain in a uniform and
+staggered longitudinal magnetic fields, where the amplitude of the staggered
+field is $\sim \delta$. We have shown that the magnetization curve of the
+system exhibits a plateau at magnetization equal to the half of the saturation
+value. The width of a plateau scales as $\delta^{\nu}$, where $\nu =4/5$ in the
+case of ladder with isotropic antiferromagnetic legs and $\nu =2$ in the case
+of ladder with isotropic ferromagnetic legs. We have calculated four critical
+fields ($H^{\pm}_{c1}$ and $H^{\pm}_{c2}$) corresponding to transitions between
+different magnetic phases of the system. We have shown that these transitions
+belong to the universality class of the commensurate-incommensurate transition.",0603153v1
+2006-07-19,Magnetic-field dependence of valley splitting for Si quantum wells grown on tilted SiGe substrates,"The valley splitting of the first few Landau levels is calculated as a
+function of the magnetic field for electrons confined in a strained silicon
+quantum well grown on a tilted SiGe substrate, using a parameterized
+tight-binding method. For a zero substrate tilt angle, the valley splitting
+slightly decreases with increasing magnetic field. In contrast, the valley
+splitting for a finite substrate tilt angle exhibits a strong and
+non-monotonous dependence on the magnetic field strength. The valley splitting
+of the first Landau level shows an exponential increase followed by a slow
+saturation as the magnetic field strength increases. The valley splitting of
+the second and third Landau levels shows an oscillatory behavior. The
+non-monotonous dependence is explained by the phase variation of the Landau
+level wave function along the washboard-like interface between the tilted
+quantum well and the buffer material. The phase variation is the direct
+consequence of the misorientation between the crystal axis and the confinement
+direction of the quantum well. This result suggests that the magnitude of the
+valley splitting can be tuned by controlling the Landau-level filling factor
+through the magnetic field and the doping concentration.",0607462v1
+2006-08-01,Non-collinear long-range magnetic ordering in HgCr2S4,"The low-temperature magnetic structure of \HG has been studied by
+high-resolution powder neutron diffraction. Long-range incommensurate magnetic
+order sets in at T$_N\sim$22K with propagation vector
+\textbf{k}=(0,0,$\sim$0.18). On cooling below T$_N$, the propagation vector
+increases and saturates at the commensurate value \textbf{k}=(0,0,0.25). The
+magnetic structure below T$_N$ consists of ferromagnetic layers in the
+\textit{ab}-plane stacked in a spiral arrangement along the \textit{c}-axis.
+Symmetry analysis using corepresentations theory reveals a point group symmetry
+in the ordered magnetic phase of 422 (D$_4$), which is incompatible with
+macroscopic ferroelectricity. This finding indicates that the spontaneous
+electric polarization observed experimentally cannot be coupled to the magnetic
+order parameter.",0608031v2
+2006-08-14,Simultaneous Antiferromagnetic Fe3+ and Nd3+ Ordering in NdFe3(11BO3)4,"By means of magnetic susceptibility and specific heat measurements, x-ray and
+unpolarised neutron diffraction investigations on powder and single-crystal
+samples, simultaneous long-range antiferromagnetic Fe and Nd ordering in
+NdFe3(11BO3)4 with R 3 2 chemical structure has been found at temperatures
+below TN = 30.5(5) K down to 1.6 K. At temperatures down to 20 K to the
+propagation vector is khex = [0,0,3/2] and becomes slightly incommensurate at
+lower temperatures. Symmetry analysis yields magnetic spiral configurations
+with the magnetic moments oriented parallel to hexagonal basal plane according
+to the irreducible representations tau_3 in the commensurate case. This is in
+agreement with the easy directions of magnetisation perpendicular to the c-axis
+as determined by magnetic susceptibility measurements. At 1.6 K the magnetic Fe
+moment amounts to 4.9 muB close to the free ion moment of Fe3+. The magnetic
+Nd3+ moment saturates presumably due to crystal-field effects at 2.7 muB.",0608304v1
+2007-07-21,Toward Coupling Flow Driven and Magnetically Driven Dynamos,"Most large scale dynamo research for astrophysical rotators focuses on
+interior flow driven helical dynamos (FDHDs), but larger scale coronal fields
+most directly influence observations. It is thus important to understand the
+relationship between coronal and interior fields. Coronal field relaxation is
+actually a type of magnetically dominated helical dynamo (MDHD). MDHDs also
+occur in fusion plasma devices where they drive a system toward its relaxed
+state in response to magnetic helicity injection that otherwise drives the
+system away from this state. Global scale fields of astrophysical rotators and
+jets are thus plausibly produced by a direct coupling between an interior FDHD
+and a coronal MDHD, interfaced by magnetic helicity transport through their
+mutual boundary. Tracking the magnetic helicity also elucidates how both FDHD
+and MDHDs evolve and saturate. The utility of magnetic helicity is unhampered
+by its non-gauge invariance since physical fields can always be recovered.",0707.3191v2
+2008-02-18,Evolution of Unmagnetized and Magnetized Shear Layers,"We present numerical simulations of the growth and saturation of the
+Kelvin-Helmholtz instability in a compressible fluid layer with and without a
+weak magnetic field. In the absence of a magnetic field, the instability
+generates a single eddy which flattens the velocity profile, stabilizing it
+against further perturbations. Adding a weak magnetic field - weak in the sense
+that it has almost no effect on the linear instability - leads to a complex
+flow morphology driven by MHD forces and to enhanced broadening of the layer,
+due to Maxwell stresses. We corroborate earlier studies which showed that
+magnetic fields destroy the large scale eddy structure through periodic cycles
+of windup and resistive decay, but we show that the rate of decay decreases
+with decreasing plasma resistivity, at least within the range of resistivity
+accessible to our simulations. Magnetization increases the efficiency of
+momentum transport, and the transport increases with decreasing resistivity.",0802.2497v1
+2008-07-22,On Fermi acceleration and MHD-instabilities at ultra-relativistic magnetized shock waves,"Fermi acceleration can take place at ultra-relativistic shock waves if the
+upstream or downstream magnetic field has been remodeled so that most of the
+magnetic power lies on short spatial scales. The relevant conditions under
+which Fermi acceleration become efficient in the presence of both a coherent
+and a short scale turbulent magnetic field are addressed. Within the MHD
+approximation, this paper then studies the amplification of a pre-existing
+magnetic field through the streaming of cosmic rays upstream of a relativistic
+shock wave. The magnetic field is assumed to be perpendicular in the shock
+front frame, as generally expected in the limit of large shock Lorentz factor.
+In the MHD regime, compressive instabilities seeded by the net cosmic-ray
+charge in the shock precursor (as seen in the shock front frame) develop on the
+shortest spatial scales but saturate at a moderate level deltaB/B ~ 1, which is
+not sufficient for Fermi acceleration. As we argue, it is possible that other
+instabilities outside the MHD range provide enough amplification to allow
+successful Fermi acceleration.",0807.3459v3
+2009-02-08,Magnetic and magnetoelectric studies in pure and cation doped BiFeO3,"We report magnetic and magnetoelectric studies on BiFeO3 and divalent cation
+(A) suvtitute Bi0.7A0.3FeO3 (A = Sr,Ba, and Sr0.5Ba0.5). It is shown that the
+rapid increase of magnetization at the Neel temperature (TN = 642 K) is
+suppressed in the co-doped compound A = Sr0.5Ba0.5. All the divalent subtituted
+compounds show enhanced magnetization and hysteresis loop. Both longitudinal
+and transverse magnetoelectric coefficients were measured using the dynamical
+lock-in technique. The co-doped compound shows the highest magnetoelectric
+coefficient at room temperature although it is not the compound with the
+highest saturation magnetization. It is found that as the size of the A-site
+cation increses, the transverse magnetoelectric coeffient increases and exceeds
+the longitudinal magnetoelectric coefficient. It is suggested that changes in
+magnetic domain structure and magnetostriction are possible reasons for the
+observed changes in the magnetoelectric coefficients.",0902.1283v1
+2009-03-11,Magnetization plateaux in the classical Shastry-Sutherland lattice,"We investigated the classical Shastry-Sutherland lattice under an external
+magnetic field in order to understand the recently discovered magnetization
+plateaux in the rare-earth tetraborides compounds RB$_4$. A detailed study of
+the role of thermal fluctuations was carried out by mean of classical spin
+waves theory and Monte-Carlo simulations. Magnetization quasi-plateaux were
+observed at 1/3 of the saturation magnetization at non zero temperature. We
+showed that the existence of these quasi-plateaux is due to an entropic
+selection of a particular collinear state. We also obtained a phase diagram
+that shows the domains of existence of different spin configurations in the
+magnetic field versus temperature plane.",0903.1985v1
+2009-05-27,Transport and Magnetic properties of PrCoIn_5,"Structural, electrical and magnetic measurements of 115 single crystals of
+PrIn$_5$ are reported. It has a tetragonal structure and has slightly lower
+cell volume than its isomorphic counter part CeCoIn_5. The resistivity
+saturates for T\geq 10K. Analysis of the resistivity for 10K<T< 60K indicates a
+regular fermi liquid behavior. It does not exhibit superconductivity down to
+T\sim 1K. The magnetic susceptibility analysis yielded the moment to be
+4.00\mu_B indicating that the magnetism of PrCoIn_5 is dominated by Pr^{3+}
+free ions with some admixture of the magnetic moment of the Co sublattice. The
+paramagnetic Curie temperature \theta \sim-40K. At low temperatures the
+susceptibility follows a broad maximum around T_N \sim 14.5K, and increases as
+the temperature is lowered. The disappearance of superconductivity for T>1K is
+attributed to chemical pressure effects and magnetic pair breaking.",0905.4536v1
+2009-07-23,Large specific absorption rates in the magnetic hyperthermia properties of metallic iron nanocubes,"We report on the magnetic hyperthermia properties of chemically synthesized
+ferromagnetic 11 and 16 nm Fe(0) nanoparticles of cubic shape displaying the
+saturation magnetization of bulk iron. The specific absorption rate measured on
+16 nm nanocubes is 1690+-160 W/g at 300 kHz and 66 mT. This corresponds to
+specific losses-per-cycle of 5.6 mJ/g, largely exceeding the ones reported in
+other systems. A way to quantify the degree of optimization of any system with
+respect to hyperthermia applications is proposed. Applied here, this method
+shows that our nanoparticles are not fully optimized, probably due to the
+strong influence of magnetic interactions on their magnetic response. Once
+protected from oxidation and further optimized, such nano-objects could
+constitute efficient magnetic cores for biomedical applications requiring very
+large heating power.",0907.4063v3
+2009-08-26,Influence of an external magnetic field on forced turbulence in a swirling flow of liquid metal,"We report an experimental investigation on the influence of an external
+magnetic field on forced 3D turbulence of liquid gallium in a closed vessel. We
+observe an exponential damping of the turbulent velocity fluctuations as a
+function of the interaction parameter N (ratio of Lorentz force over inertial
+terms of the Navier-Stokes equation). The flow structures develop some
+anisotropy but do not become bidimensional. From a dynamical viewpoint, the
+damping first occurs homogeneously over the whole spectrum of frequencies. For
+larger values of N, a very strong additional damping occurs at the highest
+frequencies. However, the injected mechanical power remains independent of the
+applied magnetic field. The simultaneous measurement of induced magnetic field
+and electrical potential differences shows a very weak correlation between
+magnetic field and velocity fluctuations. The observed reduction of the
+fluctuations is in agreement with a previously proposed mechanism for the
+saturation of turbulent dynamos and with the order of magnitude of the Von
+Karman Sodium dynamo magnetic field.",0908.3821v1
+2010-01-07,Magnetic response of nanoscale left-handed metamaterials,"Using detailed simulations we investigate the magnetic response of
+metamaterials consisting of pairs of parallel slabs or combinations of slabs
+with wires (including the fishnet design) as the length-scale of the structures
+is reduced from mm to nm. We observe the expected saturation of the magnetic
+resonance frequency when the structure length-scale goes to the sub-micron
+regime, as well as weakening of the effective permeability resonance and
+reduction of the spectral width of the negative permeability region. All these
+results are explained by using an equivalent resistor-inductor-capacitor (RLC)
+circuit model, taking into account the current-connected kinetic energy of the
+electrons inside the metallic parts through an equivalent inductance, added to
+the magnetic field inductance in the unit-cell. Using this model we derive
+simple optimization rules for achieving optical negative permeability
+metamaterials of improved performance. Finally, we analyze the magnetic
+response of the fishnet design and we explain its superior performance
+regarding the high attainable magnetic resonance frequency, as well as its
+inferior performance regarding the width of the negative permeability region.",1001.1073v1
+2010-04-07,Magnetization plateau and incommensurate spin modulation in Ca3Co2O6,"The magnetic properties of a trigonal prism unit of the spin-2 frustrated
+compound Ca3Co2O6 are studied by means of the density-matrix renormalization
+group method. A magnetization plateau at $ms/3$ ($ms$ is the saturation
+magnetization) with ferrimagnetic structure is observed. By fitting the
+experimental data of magnetic curve, an estimation of the couplings gives
+J1=-26.84K, J_{2}=0.39K, and J_{3}=0.52K. The local magnetic moments are
+unveiled to exhibit an incommensurate sinusoidally modulation along the three
+chains of the trigonal prism, which gives a strong theoretical support to the
+experimentally observed incommensurate partially disordered antiferromagnetic
+state for Ca3Co2O6. The present result suggests that the modulation indeed
+originates from the competition of antiferromagnetic and ferromagnetic
+couplings.",1004.1031v1
+2010-09-20,Variations in magnetic properties of nanostructured nickel,"The magnetic properties of carbon nanotube encapsulated nickel nanowires
+(C.E. nanowires of diameter ~ 10 nm), and its comparison to other forms of Ni
+are carried out in this work. The saturation magnetization (M_s) and coercivity
+(H_c) for C.E. nanowires are 1.0 emu/g and 230 Oe. The temperature dependence
+of coercivity follows T^0.77 dependence indicating a superparamagnetic
+behavior. The field-cooled and zero-field-cooled plots indicate that the
+blocking temperature (T_B) ~ 300 K. These altered magnetic properties of C.E.
+nanowires are mainly due to the nanoscale confinement effect from carbon
+nanotube encapsulation. The shape and magnetic environment enhance the total
+magnetic anisotropy of C.E. nanowires by a factor of four.",1009.3761v1
+2011-01-13,Frustrated couplings between alternating spin-1/2 chains in AgVOAsO4,"We report on the crystal structure and magnetic behavior of the spin-1/2
+compound AgVOAsO4. Magnetic susceptibility, high-field magnetization, and
+electron spin resonance measurements identify AgVOAsO4 as a gapped quantum
+magnet with a spin gap Delta ~ 13 K and a saturation field H_s ~ 48.5 T.
+Extensive band structure calculations establish the microscopic magnetic model
+of spin chains with alternating exchange couplings J ~ 40 K and J' ~ 26 K.
+However, the precise evaluation of the spin gap emphasizes the role of
+interchain couplings which are frustrated due to the peculiar crystal structure
+of the compound. The unusual spin model and the low energy scale of the
+exchange couplings make AgVOAsO4 a promising candidate for an experimental
+investigation of Bose-Einstein condensation and other exotic ground states in
+high magnetic fields.",1101.2546v2
+2011-02-13,Magnetization and Lyapunov exponents on a kagome chain with multi-site exchange interaction,"The Ising approximation of the Heisenberg model in a strong magnetic field,
+with two, three and six spin exchange interactions is studied on a kagome
+chain. The kagome chain can be considered as an approximation of the third
+layer of 3He absorbed on the surface of graphite (kagome lattice). By using
+dynamical approach we have found one and multi-dimensional mappings (recursion
+relations) for the partition function. The magnetization diagrams are plotted
+and they show that the kagome chain is separating into four sublattices with
+different magnetizations. Magnetization curves of two sublattices exhibit
+plateaus at zero and 2/3 of the saturation field. The maximal Lyapunov exponent
+for multi-dimensional mapping is considered and it is shown that near the
+magnetization plateaus the maximal Lyapunov exponent also exhibits plateaus.",1102.2589v1
+2011-03-31,Bulk and Surface Magnetization of Co atoms in Rutile Ti_[1-x]Co_xO_[2-delta] Thin Films Revealed by X-Ray Magnetic Circular Dichroism,"We have studied magnetism in Ti_[1-x]Co_xO_[2-\delta] thin films with various
+x and \delta by soft x-ray magnetic circular dichroism (XMCD) measurements at
+the Co L_[2,3] absorption edges. The estimated ferromagnetic moment by XMCD was
+0.15-0.24 \mu\beta/Co in the surface, while in the bulk it was 0.82-2.25
+\mu\beta/Co, which is in the same range as the saturation magnetization of
+1.0-1.5 \mu\beta/Co. Theseresults suggest that the intrinsic origin of the
+erromagnetism. The smaller moment of Co atom at surface is an indication of a
+magnetically dead layer of a few nm thick at the surface of the thin films.",1103.6092v2
+2012-03-21,High-field magnetization and magnetoresistance of the $A$-site ordered perovskite oxide CaCu$_{3}$Ti$_{4-x}$Ru$_{x}$O$_{12}$~($0 \le x \le 4$),"We have measured high-field magnetization and magnetoresistance of
+polycrystalline samples of the A-site ordered perovskite CaCu3Ti4-xRuxO12 (x=0
+- 4) utilizing a non-destructive pulsed magnet. We find that the magnetization
+for x=0.5, 1.0 and 1.5 is nonlinear, and tends to saturate in high fields. This
+is highly nontrivial because the magnetization for x=0 and 4 is linear in
+external field up to the highest one. We have analyzed this field dependence
+based on the thermodynamics of magnetic materials, and propose that the
+external fields delocalize the holes on the Cu2+ ions in order to maximize the
+entropy. This scenario is qualitatively consistent with a large
+magnetoresistance of -70% observed at 4.2 K at 52 T for x=1.5.",1203.4660v1
+2012-04-11,Frustrated magnets and quantum paramagnetic phases at finite temperature,"We develop a general framework, which combines exact diagonalization in small
+clusters with a density matrix variational principle, to study frustrated
+magnets at finite temperature. This thermodynamic hierarchical mean-field
+technique is used to determine the phase diagram and magnetization process of
+the three-dimensional spin-1/2 $J_1$-$J_2$ antiferromagnet on a stacked square
+lattice. Its non-magnetic phase exhibits a thermal crossover from a quantum to
+a classical paramagnet at a temperature $T=T_0$ which can be extracted from
+thermodynamic measurements. At low temperature an applied magnetic field
+stabilizes, through order-by-disorder, a variety of phases with non-trivial
+spin textures and a magnetization plateau at half-saturation which continuously
+disappears at $T\sim T_0$. Our results are relevant for frustrated vanadium
+oxides.",1204.2559v2
+2012-06-02,Ferromagnetism of cobalt-doped anatase TiO$_2$ studied by bulk- and surface-sensitive soft x-ray magnetic circular dichroism,"We have studied magnetism in anatase Ti$_{1-x}$Co$_x$O$_{2-\delta}$ ({\it x}
+= 0.05) thin films with various electron carrier densities, by soft x-ray
+magnetic circular dichroism (XMCD) measurements at the Co $L_{2,3}$ absorption
+edges. For electrically conducting samples, the magnetic moment estimated by
+XMCD was $<$ 0.3 $\mu_B$/Co using the surface-sensitive total electron yield
+(TEY) mode, while it was 0.3-2.4 $\mu_B$/Co using the bulk-sensitive total
+fluorescence yield (TFY) mode. The latter value is in the same range as the
+saturation magnetization 0.6-2.1 $\mu_B$/Co deduced by SQUID measurement. The
+magnetization and the XMCD intensity increased with carrier density, consistent
+with the carrier-induced origin of the ferromagnetism.",1206.0339v1
+2012-06-12,A cascade of magnetic field induced spin transitions in LaCoO3,"We present magnetization and magnetostriction studies of the insulating
+perovskite LaCoO3 in magnetic fields approaching 100 T. In marked contrast with
+expectations from single-ion models, the data reveal two distinct first-order
+spin transitions and well-defined magnetization plateaux. The magnetization at
+the higher plateau is only about half the saturation value expected for spin-1
+Co3+ ions. These findings strongly suggest collective behavior induced by
+strong interactions between different electronic -- and therefore spin --
+configurations of Co3+ ions. We propose a model of these interactions that
+predicts crystalline spin textures and a cascade of four magnetic phase
+transitions at high fields, of which the first two account for the experimental
+data.",1206.2603v1
+2012-12-19,Spontaneous atomic ordering and magnetism in epitaxially stabilized double perovskites,"We have studied the atomic ordering of B-site transition metals and magnetic
+properties in the pulsed-laser deposited films of La2CrFeO6 (LCFO) and La2VMnO6
+(LVMO), whose bulk materials are known to be single perovskites with random
+distribution of the B-site cations. Despite similar ionic characters of
+constituent transition metals in each compound, the maximum B-site order
+attained was surprisingly high, ~90% for LCFO and ~80% for LVMO, suggesting a
+significant role of epitaxial stabilization in the spontaneous ordering
+process. Magnetization and valence state characterizations revealed that the
+magnetic ground state of both compounds was coincidently ferrimagnetic with
+saturation magnetization of ~2myuB per formula unit, unlike those predicted
+theoretically. In addition, they were found to be insulating with optical band
+gaps of 1.6 eV and 0.9 eV for LCFO and LVMO, respectively. Our results present
+a wide opportunity to explore novel magnetic properties of binary
+transition-metal perovskites upon epitaxial stabilization of the ordered phase.",1212.4622v1
+2013-03-21,Tuning magnetic anisotropy in (001) oriented L10 (Fe1-xCux)55Pt45 films,"We have achieved (001) oriented L10 (Fe1-xCux)55Pt45 thin films, with
+magnetic anisotropy up to 3.6x10^7 erg/cm^3, using atomic-scale multilayer
+sputtering and post annealing at 400 {\deg}C for 10 seconds. By fixing the Pt
+concentration, structure and magnetic properties are systematically tuned by
+the Cu addition. Increasing Cu content results in an increase in the tetragonal
+distortion of the L10 phase, significant changes to the film microstructure,
+and lowering of the saturation magnetization and anisotropy. The relatively
+convenient synthesis conditions, along with the tunable magnetic properties,
+make such materials highly desirable for future magnetic recording
+technologies.",1303.5208v1
+2013-04-08,Reentrant cluster glass behavior in La2CoMnO6 nanoparticles,"Magnetic study on La2CoMnO6 nanoparticles revealed multiple magnetic
+transitions at 218 K, 135 K and below 38 K and the nature of the low
+temperature transition was unclear [J Appl Phys 111, 024102 2012]. Presence of
+mixed valance states of Co and Mn has been confirmed from the XPS measurement
+and its presence along with antisite disorder affects in reducing the
+saturation magnetization of the nanoparticles. The zero field cooled and field
+cooled bifurcation in dc magnetization, relaxation in zero field cooled
+magnetization and large enhancement in coercive field below the glassy
+temperature has been discussed. Frequency dependence of ac susceptibility using
+power law has revealed cluster glass behavior. Further, the dc field
+superimposed on ac susceptibility and absence of memory effect in ac
+susceptibility has suggested the existence of non interacting clusters
+comprising of competing interactions below 38 K. Competing magnetic
+interactions due to the presence of mixed valances and antisite disorder found
+to establish a reentered cluster glassy state in the nanoparticles.",1304.2267v1
+2013-06-13,"Investigation of the quaternary Fe2-xCoxMnSi alloys by structural, magnetic, resistivity and spin polarization measurements","Effects of the Co substitution have been observed on the structural, magnetic
+and magneto-transport properties of Fe2-xCoxMnSi alloy. Curie temperature (TC)
+and saturation magnetization (MS) of these alloys increased linearly with the
+Co substitution. Competitive magnetic interaction between ferromagnetic (FM)
+and anti-ferromagnetic (AFM) phases exists in Fe2-xCoxMnSi for x less than 0.2,
+AFM phase is completely disappears for x greater than or equal to 0.2. The
+value of Rhodes-Wohlfarth ratio pc/ps is greater than one for these alloys
+which is the characteristics of iterant magnetism present in the system.
+M\""ossbauer spectroscopic measurements have been done to investigate the atomic
+disorder and local magnetic moment for some x values. Resistivity measurements
+also confirm the stability of ferromagnetism with the concentration of Co and
+also show a sign of half metallicity. Resistivity shows semiconducting
+behaviour for x = 0.4 which is interesting in view of spin gapless
+semiconductors.",1306.3086v3
+2013-07-18,Correlation between defect and magnetism of Ar9+ implanted and un-implanted Zn0.95Mn0.05O thin films suitable for electronic application,"Sol-gel derived thin films of Zn0.95Mn0.05O have been implanted with Ar9+
+ions with doses viz. 5x10e14 ions/cm2 (low), 1x10e15 ions/cm2 (intermediate)
+and 1x10e16 ions/cm2 (high). Structural, morphological, optical and magnetic
+properties of the films have been investigated. Structural study confirmed
+single phase, wurtzite structure of the films. The absence of impurity phase
+has been confirmed from several measurements. Ion implantation induces a large
+concentration of point defects into the films as identified from optical study.
+All films exhibit well above room temperature (RT) intrinsic ferromagnetism
+(FM) as evidenced from field and temperature dependent magnetization
+measurements. The magnetization attains the maximum value for high dose of Ar9+
+ion implanted film. It shows RT saturation magnetization (MS) value of
+0.69emu/gm. The observed FM has been correlated with proportion of intrinsic
+defects, such as, zinc and oxygen vacancies and the values of MS. Defect
+induced formation of bound magnetic polaron actually controls the FM. The
+utility of these films in transparent spin electronic device has also been
+exhibited.",1307.4895v1
+2013-10-24,Towards wafer scale inductive determination of magnetostatic and dynamic parameters of magnetic thin films and multilayers,"We investigate an inductive probe head suitable for non-invasive
+characterization of the magnetostatic and dynamic parameters of magnetic thin
+films and multilayers on the wafer scale. The probe is based on a planar
+waveguide with rearward high frequency connectors that can be brought in close
+contact to the wafer surface. Inductive characterization of the magnetic
+material is carried out by vector network analyzer ferromagnetic resonance.
+Analysis of the field dispersion of the resonance allows the determination of
+key material parameters such as the saturation magnetization MS or the
+effective damping parameter Meff. Three waveguide designs are tested. The
+broadband frequency response is characterized and the suitability for inductive
+determination of MS and Meff is compared. Integration of such probes in a wafer
+prober could in the future allow wafer scale in-line testing of magnetostatic
+and dynamic key material parameters of magnetic thin films and multilayers.",1310.6578v1
+2014-08-18,Magnetic Spiral Arms and Galactic Outflows,"Galactic magnetic arms have been observed between the gaseous arms of some
+spiral galaxies; their origin remains unclear. We suggest that magnetic spiral
+arms can be naturally generated in the interarm regions because the galactic
+fountain flow or wind is likely to be weaker there than in the arms. Galactic
+outflows lead to two countervailing effects: removal of small-scale magnetic
+helicity, which helps to avert catastrophic quenching of the dynamo, and
+advection of the large-scale magnetic field, which suppresses dynamo action.
+For realistic galactic parameters, the net consequence of outflows being
+stronger in the gaseous arms is higher saturation large-scale field strengths
+in the interarm regions as compared to in the arms. By incorporating rather
+realistic models of spiral structure and evolution into our dynamo models, an
+interlaced pattern of magnetic and gaseous arms can be produced.",1408.3937v2
+2014-09-02,Anisotropic magnetodielectric coupling behavior of Ca3Co1.4Rh0.6O6 due to geometrically frustrated magnetism,"We have investigated the magnetic, dielectric and magnetodielectric (MDE)
+behavior of a geometrically frustrated spin-chain system, Ca3Co1.4Rh0.6O6, in
+the single crystalline form for different orientations. The results bring out
+that the magnetic behavior of this compound is by itself interesting in the
+sense that this compound exhibits an anisotropic glassy-like magnetic behavior
+with a huge frequency dependence of ac susceptibility peak for an orientation
+along the spin-chain in the range 30-60 K; this behavior is robust to
+applications of large external magnetic fields (H) unlike in canonical
+spin-glasses. The temperature dependence of dielectric constant also shows
+strong frequency dependence with similar robustness to H. The isothermal
+H-dependent dielectric results at low temperatures establishes anisotropic MDE
+coupling. It is intriguing to note that there is a 'step' roughly at one-third
+of saturation values as in the case of isothermal magnetization curves for same
+temperatures (for orientation along spin-chain), a correlation hitherto
+unrealized for geometrically frustrated systems.",1409.0783v1
+2014-10-21,Investigation of Force-Freeness of Solar Emerging Magnetic Field via Application of the Virial Theorem to MHD Simulations,"Force-freeness of a solar magnetic field is a key to reconstructing invisible
+coronal magnetic structure of an emerging flux region on the Sun where active
+phenomena such as flares and coronal mass ejections frequently occur. We have
+performed magnetohydrodynamic (MHD) simulations which are adjusted to
+investigate force-freeness of an emerging magnetic field by using the virial
+theorem. Our focus is on how the force-free range of an emerging flux region
+develops and how it depends on the twist of a pre-emerged magnetic field. As an
+emerging flux region evolves, the upper limit of the force-free range
+continuously increases while the lower limit is asymptotically reduced to the
+order of a photospheric pressure scale height above the solar surface. As the
+twist becomes small the lower limit increases and then seems to be saturated.
+We also discuss the applicability of the virial theorem to an evolving magnetic
+structure on the Sun.",1410.5542v1
+2014-11-04,Magnetoimpedance effect at the high frequency range for the thin film geometry: Numerical calculation and experiment,"The magnetoimpedance effect is a versatile tool to investigate ferromagnetic
+materials, revealing aspects on the fundamental physics associated to
+magnetization dynamics, broadband magnetic properties, important issues for
+current and emerging technological applications for magnetic sensors, as well
+as insights on ferromagnetic resonance effect at non-saturated magnetic states.
+Here, we perform a theoretical and experimental investigation of the
+magnetoimpedance effect for the thin film geometry in a wide frequency range.
+We calculate the longitudinal magnetoimpedance for single layered, multilayered
+or exchange biased systems from an approach that considers a magnetic
+permeability model for planar geometry and the appropriate magnetic free energy
+density for each structure. From numerical calculations and experimental
+results found in literature, we analyze the magnetoimpedance behavior, and
+discuss the main features and advantages of each structure. To test the
+robustness of the approach, we directly compare theoretical results with
+experimental magnetoimpedance measurements obtained in a wide range of
+frequencies for an exchange biased multilayered film. Thus, we provide
+experimental evidence to confirm the validity of the theoretical approach
+employed to describe the magnetoimpedance in ferromagnetic films, revealed by
+the good agreement between numerical calculations and experimental results.",1411.0971v1
+2014-11-23,Studying the Magnetic Properties of CoSi Single Crystals,"The magnetic properties of CoSi single crystals have been measured in a range
+of temperatures $T = 5.5 - 450$ K and magnetic field strengths $H \leq 11$ kOe.
+A comparison of the results for crystals grown in various laboratories allowed
+the temperature dependence of magnetic susceptibility $\chi(T) = M(T)/H$ to be
+determined for a hypothetical ""ideal"" (free of magnetic impurities and defects)
+CoSi crystal. The susceptibility of this ideal crystal in the entire
+temperature range exhibits a diamagnetic character. The $\chi(T)$ value
+significantly increases in absolute value with decreasing temperature and
+exhibits saturation at the lowest temperatures studied. For real CoSi crystals
+of four types, paramagnetic contributions to the susceptibility have been
+evaluated and nonlinear (with respect to the field) contributions to the
+magnetization have been separated and taken into account in the calculations of
+$\chi(T)$.",1411.6242v1
+2014-12-15,High pressure neutron scattering of the magnetoelastic Ni-Cr Prussian blue analogue,"This paper summarizes 0 GPa to 0.6 GPa neutron diffraction measurements of a
+nickel hexacyanochromate coordination polymer (NiCrPB) that has the
+face-centered cubic, Prussian blue structure. Deuterated powders of NiCrPB
+contain ~100 nm sided cubic particles. The application of a large magnetic
+field shows the ambient pressure, saturated magnetic structure. Pressures of
+less than 1 GPa have previously been shown to decrease the magnetic
+susceptibility by as much as half, and we find modifications to the nuclear
+crystal structure at these pressures that we quantify. Bridging cyanide
+molecules isomerize their coordination direction under pressure to change the
+local ligand field and introduce inhomogeneities in the local (magnetic)
+anisotropy that act as pinning sites for magnetic domains, thereby reducing the
+low field magnetic susceptibility.",1412.4712v1
+2015-06-09,Spin dynamics in a Curie-switch,"Ferromagnetic resonance properties of F$_1$/f/F$_2$/AF multilayers, where
+weakly ferromagnetic spacer f is sandwiched between strongly ferromagnetic
+layers F$_1$ and F$_2$, with F$_1$ being magnetically soft and F$_2$ -
+magnetically hard due to exchange pinning to antiferromagnetic layer AF, are
+investigated. Spacer-mediated exchange coupling is shown to strongly affect the
+resonance fields of both F$_1$ and F$_2$ layers. Our theoretical calculations
+as well as measurements show that the key magnetic parameters of the spacer,
+which govern the ferromagnetic resonance in F$_1$/f/F$_2$/AF, are the magnetic
+exchange length ($\Lambda$), effective saturation magnetization at $T=0$
+$(m_0)$, and effective Curie temperature ($T_{\text{C}}^{\text{eff}}$). The
+values of these key parameters are deduced from the experimental data for
+multilayers with f = Ni$_x$Cu$_{100-x}$, for the key ranges in Ni-concentration
+($x=54\div70$ at. %) and spacer thickness ($d=3\div 6$ nm). The results
+obtained provide a deeper insight into thermally-controlled spin precession and
+switching in magnetic nanostructures, with potential applications in spin-based
+oscillators and memory devices.",1506.02928v1
+2015-07-02,Macroscopic Simulation of Isotropic Permanent Magnets,"Accurate simulations of isotropic permanent magnets require to take the
+magnetization process into account and consider the anisotropic, nonlinear, and
+hysteretic material behaviour near the saturation configuration. An efficient
+method for the solution of the magnetostatic Maxwell equations including the
+description of isotropic permanent magnets is presented. The algorithm can
+easily be implemented on top of existing finite element methods and does not
+require a full characterization of the hysteresis of the magnetic material.
+Strayfield measurements of an isotropic permanent magnet and simulation results
+are in good agreement and highlight the importance of a proper description of
+the isotropic material.",1507.00450v1
+2015-08-10,Field dependent magnetization of BiFeO3 in ultrathin La0.7Sr0.3MnO3/BiFeO3 superlattice,"We report the observation of field-induced magnetization of BiFeO3 (BFO) in
+an ultrathin BFO/La0.7Sr0.3MnO3 (LSMO) superlattice using polarized neutron
+reflectivity (PNR). Our PNR results indicate parallel alignment of
+magnetization across BFO/LSMO interfaces. The study showed an increase in
+average magnetization on increasing applied magnetic field at 10K. We observed
+a saturation magnetization of 110 \pm 15 kA/m (~0.8 {\mu}B/Fe) for ultrathin
+BFO layer (~2 unit cell) sandwiched between ultrathin LSMO layers (~ 2 unit
+cell), which is much higher than the canted moment (0.03 {\mu}B/Fe) in the bulk
+BFO. The macroscopic VSM results on superlattice clearly indicate
+superparamagnetic behavior typically observed in nanoparticles of manganites.",1508.02218v1
+2015-08-31,Surface functionalization enhanced magnetism in SnO_2 nanoparticles and its correlation to photoluminescence properties,"High value of magnetic moment 0.08 emu/g at room temperature for SnO_2
+nanoparticles (NPs) was observed. Surface functionalization with
+octadecyltrichlorosilane (OTS) enhanced the saturation magnetic moment of NPs
+to an anomalously high value of 0.187 emu/g by altering the electronic
+configuration on NPs surface. Surface functionalization also suppressed
+photoluminescence (PL) peaks arising from oxygen defects around 2 eV and caused
+an increase in the intensities of two peaks near violet region (2.6 - 3 eV). PL
+studies under uniform external magnetic field enriched understanding of the
+role of OTS. Both OTS and external magnetic field significantly modulated the
+luminescence spectra, by altering the surface electronic structure of NPs.
+Extra spins on the surface of SnO2 NPs created by the surface functionalization
+process and their influence on resultant magnetic moment and luminescence
+properties are discussed in details.",1508.07791v1
+2015-11-06,"Structural, magnetic and electrical properties of sputter deposited Mn-Fe-Ga thin films","We investigated structural, magnetic and electrical properties of sputter
+deposited Mn-Fe-Ga compounds. The crystallinity of the Mn-Fe-Ga thin films was
+confirmed using x-ray diffraction. X-ray reflection and atomic force microscopy
+measurements were utilized to investigate the surface properties, roughness,
+thickness and density of the deposited Mn-Fe-Ga. Depending on the
+stoichiometry, as well as the used substrates (SrTiO3 (001) and MgO (001)) or
+buffer layer (TiN) the Mn-Fe-Ga crystallizes in the cubic or the tetragonally
+distorted phase. Anomalous Hall effect and alternating gradient magnetometry
+measurements confirmed strong perpendicular magnetocrystalline anisotropy. Low
+saturation magnetization and hard magnetic behavior was reached by tuning the
+composition. Temperature dependent anomalous Hall effect measurements in a
+closed cycle He-cryostat showed a slight increase in coercivity with decreasing
+temperature (300K to 2K). TiN buffered Mn2.7Fe0.3Ga revealed sharper switching
+of the magnetization compared to the unbuffered layers.",1511.02097v2
+2016-04-18,Spontaneous Formation of Surface Magnetic Structure from Large-scale Dynamo in Strongly-stratified Convection,"We report the first successful simulation of spontaneous formation of surface
+magnetic structures from a large-scale dynamo by strongly-stratified thermal
+convection in Cartesian geometry. The large-scale dynamo observed in our
+strongly-stratified model has physical properties similar to those in earlier
+weakly-stratified convective dynamo simulations, indicating that the
+$\alpha^2$-type mechanism is responsible for it. Additionally to the
+large-scale dynamo, we find that large-scale structures of the vertical
+magnetic field are spontaneously formed in the convection zone surface only for
+the case of strongly-stratified atmosphere. The organization of the vertical
+magnetic field proceeds in the upper convection zone within tens of convective
+turn-over time and band-like bipolar structures are recurrently-appeared in the
+dynamo-saturated stage. We examine possibilities of several candidates as the
+origin of the surface magnetic structure formation, and then suggest the
+existence of an as-yet-unknown mechanism for the self-organization of the
+large-scale magnetic structure, which should be inherent in the
+strongly-stratified convective atmosphere.",1604.05374v1
+2016-07-13,"Breakdown of a Magnetization Plateau in Ferrimagnetic Mixed Spin-(1/2,S) Heisenberg Chains Due to a Quantum Phase Transition Towards the Luttinger Spin Liquid","Magnetization curves of the ferrimagnetic mixed spin-(1/2,S) Heisenberg
+chains are calculated with the help of density-matrix renormalization group
+method for several quantum spin numbers S=1, 3/2, 2 and 5/2. It is shown that
+the ferrimagnetic mixed spin-(1/2,S) Heisenberg chains exhibit irrespective of
+the spin value S exactly one intermediate magnetization plateau, which can be
+identified with the gapped Lieb-Mattis ferrimagnetic ground state. The
+magnetization plateau due to the Lieb-Mattis ferrimagnetism breaks down at a
+quantum phase transition towards the Luttinger spin liquid, which is
+characterized by a continuous change of the magnetization with the magnetic
+field until another quantum critical point is reached at the saturation field.",1607.03617v1
+2016-08-09,Infinitely Multiple Steps in Magnetization of Ferro- and Antiferromagnetic Ising Models with Frustration on a Diamond Hierarchical Lattice,"Magnetizations of ferro- and antiferromagnetic Ising models with frustration
+on diamond hierarchical lattices are exactly obtained at zero temperature. For
+the zero-field classical spin-liquid phase found in [Kobayashi {\it et al}, J.
+Phys. Soc. Jpn. 78, 074004 (2009) ], for which frustrating interactions play an
+important role, an infinitely small applied magnetic field can induce an
+infinitely small magnetization, despite classical Ising models that have
+discrete energy levels. In antiferromagnetic systems, the magnetization cannot
+saturate under finite magnetic fields owing to the competition between the
+unfrustrating antiferromagnetic interaction and the Zeeman interaction and an
+intrinsic long-range nature of hierarchical lattices.",1608.02865v1
+2016-08-09,Exact Solutions on the Ground States of Ising Models in Magnetic Fields with Frustration on a Diamond Hierarchical Lattice,"Magnetization processes of Ising models with frustration on diamond
+hierarchical lattices, which contain vertices with high coordination numbers,
+are exactly obtained at zero temperature. In antiferromagnetic systems, the
+magnetization cannot saturate under finite magnetic fields owing to the
+competition between the antiferromagnetic and Zeeman interactions and the
+intrinsic long-range nature of hierarchical lattices. For the zero-field
+classical spin-liquid phase found in [Kobayashi et al., J. Phys. Soc. Jpn. 78,
+074004 (2009)], an infinitely small applied magnetic field can induce an
+infinitely small magnetization, despite Ising models that have discrete energy
+levels. By examining the structure of the partition function, we obtain the
+ground state spin-configurations and clarify the mechanism of the ""gapless like
+behavior"".",1608.02878v1
+2016-10-21,Tailoring non-collinear magnetism by misfit dislocation lines,"The large epitaxial stress induced by the misfit between a triple atomic
+layer Fe film and an Ir(111) substrate is relieved by the formation of a dense
+dislocation line network. Spin-polarized scanning tunneling microscopy (SP-STM)
+investigations show that the strain is locally varying within the Fe film and
+that this variation affects the magnetic state of the system. Two types of
+dislocation line regions can be distinguished and both exhibit spin spirals
+with strain-dependent periods (ranging from 3 nm to 10 nm). Using a simple
+micromagnetic model, we attribute the changes of the period of the spin spirals
+to variations of the effective exchange coupling in the magnetic film. This
+assumption is supported by the observed dependence of the saturation magnetic
+field on the spin spiral period. Moreover, magnetic skyrmions appear in an
+external magnetic field only in one type of dislocation line area, which we
+impute to the different pinning properties of the dislocation lines.",1610.06785v1
+2016-11-09,Voltage control of magnetic anisotropy in epitaxial Ru/Co2FeAl/MgO heterostructures,"Voltage control of magnetic anisotropy (VCMA) in magnetic heterostructures is
+a key technology for achieving energy-efficiency electronic devices with
+ultralow power consumption. Here, we report the first demonstration of the VCMA
+effect in novel epitaxial Ru/Co2FeAl(CFA)/MgO heterostructures with interfacial
+perpendicular magnetic anisotropy (PMA). Perpendicularly magnetized tunnel
+junctions with the structure of Ru/CFA/MgO were fabricated and exhibited an
+effective voltage control on switching fields for the CFA free layer. A large
+VCMA coefficient of 108 (139) fJ/Vm for the CFA film was achieved at room
+temperature (4 K). The interfacial stability in the heterostructure was
+confirmed by repeating measurements. Temperature dependences of both the
+interfacial PMA and the VCMA effect were also investigated. It is found that
+the temperature dependences follow power laws of the saturation magnetization
+with an exponent of ~2. The significant VCMA effect observed in this work
+indicates that the Ru/CFA/MgO heterostructure could be one of the promising
+candidates for spintronic devices with voltage control.",1611.02827v1
+2016-12-30,Nuclear magnetic resonance signature of the spin-nematic phase in LiCuVO$_{4}$ at high magnetic fields,"We report a 51V nuclear magnetic resonance investigation of the frustrated
+spin-1/2 chain compound LiCuVO4, performed in pulsed magnetic fields and
+focused on high-field phases up to 55 T. For the crystal orientations H // c
+and H // b we find a narrow field region just below the magnetic saturation
+where the local magnetization remains uniform and homogeneous, while its value
+is field dependent. This behavior is the first microscopic signature of the
+spin-nematic state, breaking spin-rotation symmetry without generating any
+transverse dipolar order, and is consistent with theoretical predictions for
+the LiCuVO4 compound.",1612.09483v3
+2017-02-19,The population of highly magnetized neutron stars,"In this work, we study the effects of strong magnetic field configurations on
+the population of neutron stars. The stellar matter is described within a
+relativistic mean field formalism which considers many-body force contributions
+in the scalar couplings. We choose the parametrization of the model that
+reproduces nuclear matter properties at saturation and also describes massive
+hyperon stars. Hadronic matter is modeled at zero temperature, in
+beta-equilibrium, charge neutral and populated by the baryonic octet, electrons
+and muons. Magnetic effects are taken into account in the structure of stars by
+the solution of the Einstein-Maxwell equations with the assumption of a
+poloidal magnetic field distribution. Our results show that magnetic neutron
+stars are populated essencialy by nucleons and leptons, due to the fact that
+strong magnetic fields decrease the central density of stars and, hence,
+supress the appearance of exotic particles.",1702.05684v2
+2017-03-15,Anisotropic super-paramagnetism in cobalt implanted rutile-TiO2 single crystals,"We study the magnetic properties of single crystals of rutile TiO2 implanted
+with cobalt for various fluences. The temperature variation of zero field
+cooled(ZFC) and field cooled (FC) magnetization shows a much higher blocking
+temperature (TB) along [1-10]. Similarly the scaling of magnetization isotherms
+above TB is seen only when the field is parallel to [1-10] direction. With
+field along this direction, the magnetization shows near saturation at a much
+smaller field compared to that of[001] direction. The Co nanoclusters possess
+an ""easy"" and ""hard axis"" of magnetization coupled by the magneto crystalline
+anisotropy of secondary phases of cobalt with TiO2. In addition, at T=2 K we
+observe a crossover in the magnetization vs field isotherms between the two
+field directions in the samples which has been attributed to the anisotropic
+paramagnetism arising from cobalt present in 2+ ionic state with S = 3/2.",1703.04965v1
+2017-06-23,Detection of induced paramagnetic moments in Pt on Y$_3$Fe$_5$O$_{12}$ via x-ray magnetic circular dichroism,"Magnetic moments in an ultra-thin Pt film on a ferrimagnetic insulator
+Y$_3$Fe$_5$O$_{12}$ (YIG) have been investigated at high magnetic fields and
+low temperatures by means of X-ray magnetic circular dichroism (XMCD). We
+observed an XMCD signal due to the magnetic moments in a Pt film at the Pt
+$L_{3}$- and $L_{2}$-edges. By means of the element-specific magnetometry, we
+found that the XMCD signal at the Pt $L_{3}$-edge gradually increases with
+increasing the magnetic field even when the field is much greater than the
+saturation field of YIG. Importantly, the observed XMCD intensity was found to
+be much greater than the intensity expected from the Pauli paramagnetism of Pt
+when the Pt film is attached to YIG. These results imply the emergence of
+induced paramagnetic moments in Pt on YIG and explain the characteristics of
+the unconventional Hall effect in Pt/YIG systems.",1706.07559v1
+2017-09-07,Could the low braking index pulsar PSR J1734-3333 evolve into a magnetar?,"The low braking-index pulsar PSR J1734$-$3333 could be born with superhigh
+internal magnetic fields $B_{\rm in}\sim10^{15}-10^{16}$ G, and undergo a
+supercritical accretion soon after its formation in a supernova explosion. The
+buried multipole magnetic fields will merger into a dipole magnetic field.
+Since the magnetic flow transfers from the core to the crust of the pulsar, its
+surface dipole field grows quickly at a power-law form assumed until it
+saturates at the level of internal dipole field. The increase in surface dipole
+magnetic field results in the observed low braking index of $n=0.9(2)$. Keeping
+an average field growth index $\varepsilon=1.34(6)$, this pulsar will become a
+magnetar with surface dipole magnetic field at the equator $B_{\rm d}\sim
+2.6(1)\times 10^{14}$\,G and $\sim 5.3(2)\times 10^{14}$\,G after next 50\,kyrs
+and 100\,kys, respectively.",1709.02734v3
+2017-10-12,Frustrated two dimensional quantum magnets,"We overview physical effects of exchange frustration and quantum spin
+fluctuations in (quasi-) two dimensional (2D) quantum magnets ($S=1/2$) with
+square, rectangular and triangular structure. Our discussion is based on the
+$J_1$-$J_2$ type frustrated exchange model and its generalizations. These
+models are closely related and allow to tune between different phases,
+magnetically ordered as well as more exotic nonmagnetic quantum phases by
+changing only one or two control parameters. We survey ground state properties
+like magnetization, saturation fields, ordered moment and structure factor in
+the full phase diagram as obtained from numerical exact diagonalization
+computations and analytical linear spin wave theory. We also review finite
+temperature properties like susceptibility, specific heat and magnetocaloric
+effect using the finite temperature Lanczos method. This method is powerful to
+determine the exchange parameters and g-factors from experimental results. We
+focus mostly on the observable physical frustration effects in magnetic phases
+where plenty of quasi-2D material examples exist to identify the influence of
+quantum fluctuations on magnetism.",1710.04399v1
+2018-01-23,Correlation between Magnetic Properties and Depinning Field in Field-Driven Domain Wall Dynamics in GdFeCo Ferrimagnets,"The influence of temperature on the magnetic-field-driven domain wall (DW)
+motion is investigated in GdFeCo ferrimagnets with perpendicular magnetic
+anisotropy (PMA). We find that the depinning field strongly depends on
+temperature. Moreover, it is also found that the saturation magnetization
+exhibits a similar dependence on temperature to that of depinning field. From
+the creep-scaling criticality, a simple relation between the depinning field
+and the properties of PMA is clearly identified theoretically as well as
+experimentally. Our findings open a way for a better understanding how the
+magnetic properties influence on the depinning field in magnetic system and
+would be valuably extended to depinning studies in other system.",1801.07436v1
+2018-02-26,Small-scale dynamos in simulations of stratified turbulent convection,"Small-scale dynamo action is often held responsible for the generation of
+quiet-Sun magnetic fields. We aim to determine the excitation conditions and
+saturation level of small-scale dynamos in non-rotating turbulent convection at
+low magnetic Prandtl numbers. We use high resolution direct numerical
+simulations of weakly stratified turbulent convection. We find that the
+critical magnetic Reynolds number for dynamo excitation increases as the
+magnetic Prandtl number is decreased, which might suggest that small-scale
+dynamo action is not automatically evident in bodies with small magnetic
+Prandtl numbers as the Sun. As a function of the magnetic Reynolds number
+(${\rm Rm}$), the growth rate of the dynamo is consistent with an ${\rm
+Rm}^{1/2}$ scaling. No evidence for a logarithmic increase of the growth rate
+with ${\rm Rm}$ is found.",1802.09607v1
+2018-04-10,Force-detected high-frequency electron spin resonance spectroscopy using magnet-mounted nanomembrane: robust detection of thermal magnetization modulation,"In this study, we report a conceptually novel broadband high-frequency
+electron spin resonance (HFESR) spectroscopic technique. In contrast to the
+ordinary force-detected ESR technique, which detects the magnetization change
+due to the saturation effect, this method measures the magnetization change due
+to the change of the sample temperature at resonance. To demonstrate its
+principle, we developed a silicon nitride nanomembrane-based force-detected ESR
+spectrometer, which can be stably operated even at high magnetic fields. Test
+measurements were performed for samples with different spin relaxation times.
+We succeeded in obtaining a seamless ESR spectrum in magnetic fields of 15~T
+and frequencies of 636~GHz without significant spectral distortion. A high spin
+sensitivity of $10^{12}$~spins/G$\cdot$s was obtained, which was independent of
+the spin relaxation time. These results show that this technique can be used as
+a practical method in research fields where the HFESR technique is applicable.",1804.03345v3
+2018-07-05,Domain wall dynamics for an in-plane magnetized thin film with large perpendicular hard axis anisotropy including Dzyaloshinskii-Moriya interaction,"We consider a thin ferromagnetic layer to which an external field or a
+current are applied along an in plane easy axis. The perpendicular hard axis
+anisotropy constant is large so that the out of plane magnetization component
+is smaller than the in plane components. A perturbation approach is used to
+obtain the profile and velocity of the moving domain wall. The dynamics of the
+in plane components of the magnetization is governed by a reaction diffusion
+equation which determines the speed of the profile. We find a simple analytic
+expression for the out of plane magnetization showing a symmetric distortion
+due to the motion in addition to the asymmetric component due to the
+Dzyaloshinskii--Moriya interaction. The results obtained complement previous
+studies in which either the Dzyalozhinskii vector or the out of plane hard axis
+anisotropy were assumed small. In the regime studied the Walker breakdown is
+not observed but the reaction diffusion dynamics predicts a slowing down of the
+domain wall for sufficiently large magnetic field. The transition point depends
+on the applied field, saturation magnetization and easy axis anisotropy.",1807.02032v1
+2018-07-25,Thermodynamics of a frustrated quantum magnet on a square lattice,"We report the magnetic and calorimetric measurements in single crystal
+samples of the square lattice $J_{1}-J_{2}$ quantum antiferromagnet
+BaCdVO(PO$_4$)$_2$. An investigation of the scaling of magnetization reveals a
+""dimensionality reduction"" indicative of a strong degree of geometric
+frustration. Below a characteristic temperature of $T^{\ast}\simeq150$~mK we
+observe the emergence of an additional strongly fluctuating quantum phase close
+to full magnetic saturation. It is separated from the magnetically ordered
+state by first- and second-order phase transitions, depending on the
+orientation of the applied magnetic field. We suggest that this phase may
+indeed be related to the theoretically predicted spin-nematic state.",1807.09549v2
+2018-12-11,"Enhanced mixing in magnetized fingering convection, and implications for RGB stars","Double-diffusive convection has been well studied in geophysical contexts,
+but detailed investigations of the regimes characteristic of stellar or
+planetary interiors have only recently become feasible. Since most
+astrophysical fluids are electrically conducting, it is possible that magnetic
+fields play a role in either enhancing or suppressing double-diffusive
+convection, but to date there have been no numerical investigations of such
+possibilities. Here we study the effects of a vertical background magnetic
+field (aligned with the gravitational axis) on the linear stability and
+nonlinear saturation of fingering (thermohaline) convection, through a
+combination of theoretical work and direct numerical simulations (DNSs). We
+find that a vertical magnetic field rigidifies the fingers along the vertical
+direction which has the remarkable effect of enhancing vertical mixing. We
+propose a simple analytical model for mixing by magnetized fingering
+convection, and argue that magnetic effects may help explain discrepancies
+between theoretical and observed mixing rates in low-mass red giant branch
+(RGB) stars. Other implications of our findings are also discussed.",1812.04687v1
+2019-03-29,Putative spin-nematic phase in BaCdVO(PO$_{4}$)$_{2}$,"We report neutron scattering and AC magnetic susceptibility measurements of
+the 2D spin-1/2 frustrated magnet BaCdVO(PO$_{4}$)$_{2}$. At temperatures well
+below $T_{\sf N}\approx 1K$, we show that only 34 % of the spin moment orders
+in an up-up-down-down strip structure. Dominant magnetic diffuse scattering and
+comparison to published $\mu$sr measurements indicates that the remaining 66 %
+is fluctuating. This demonstrates the presence of strong frustration,
+associated with competing ferromagnetic and antiferromagnetic interactions, and
+points to a subtle ordering mechanism driven by magnon interactions. On
+applying magnetic field, we find that at $T=0.1$ K the magnetic order vanishes
+at 3.8 T, whereas magnetic saturation is reached only above 4.5 T. We argue
+that the putative high-field phase is a realization of the long-sought
+bond-spin-nematic state.",1903.12462v1
+2019-07-27,Magnetization plateau of the $S=2$ antiferromagnetic Heisenberg chain with anisotropies,"We investigate the $S=2$ antiferromagnetic quantum spin chain with the
+exchange and single-ion anisotropies in a magnetic field, using the numerical
+exact diagonalization of finite-size clusters and the level spectroscopy
+analysis. It is found that a magnetization plateau possibly appears at a half
+of the saturation magnetization for some suitable anisotropy parameters. The
+level spectroscopy analysis indicates that the 1/2 magnetization plateau is
+formed by two different mechanisms, depending on the anisotropy parameters. The
+phase diagram of the 1/2 plateau states and some typical magnetization curves
+are also presented. In addition the biquadratic interaction is revealed to
+enhance the plateau induced by the Haldane mechanism.",1907.11931v2
+2019-09-04,Density wave and topological reconstruction of an isotropic two-dimensional electron band in external magnetic field,"We predict a mechanism of spontaneous stabilization of a uniaxial density
+wave in a two-dimensional metal with an isotropic Fermi surface in the presence
+of external magnetic field. The topological transformation of a closed Fermi
+surface into an open one decreases the electron band energy due to
+delocalization of electrons initially localized by magnetic field, additionally
+affected by the magnetic breakdown effect. The driving mechanism of such
+reconstruction is a periodic potential due to the self-consistently formed
+electron density wave. It is accompanied with quantum oscillations periodic in
+inverse magnetic field, similar to the standard de Haas - van Alphen effect,
+due to Landau level filling. The phase transition appears as a quantum one at
+T=0, provided the relevant coupling constant is above the critical one. This
+critical value rapidly decreases, and finally saturates toward zero on the
+scale of tens of Tesla. Thus, a strong enough magnetic field can induce the
+density wave in the system in which it was absent in zero field.",1909.01781v1
+2019-11-18,Chemical synthesis and magnetic properties of monodisperse cobalt ferrite nanoparticles,"In this work, a successful synthesis of magnetic cobalt ferrite (CoFe2O4)
+nanoparticles is presented. The synthesized CoFe2O4 nanoparticles have a
+spherical shape and highly monodisperse in the selected solvent. The effect of
+different reaction conditions such as temperature, reaction time and varying
+capping agents on the phase and morphology is studied. Scanning transmission
+electron microscopy showed that the size of these nanoparticles can be
+controlled by varying reaction conditions. Both X-ray diffraction and energy
+dispersive X-ray spectroscopy corroborate the formation of CoFe2O4 spinel
+structure with cubic symmetry. Due to optimized reaction parameters, each
+nanoparticle was shown to be a single magnetic domain with diameter ranges from
+6 to 16 nm. Finally, the magnetic investigations showed that the obtained
+nanoparticles are superparamagnetic with a small coercivity value of about 315
+Oe and a saturation magnetization of 58 emu/g at room temperature. These
+results make the cobalt ferrite nanoparticles promising for advanced magnetic
+nanodevices and biomagnetic applications.",1911.07496v1
+2020-02-07,Half-magnetization plateau and the origin of threefold symmetry breaking in an electrically-switchable triangular antiferromagnet,"We perform high-field magnetization measurements on the triangular lattice
+antiferromagnet Fe$_{1/3}$NbS$_2$. We observe a plateau in the magnetization
+centered at approximately half the saturation magnetization over a wide range
+of temperature and magnetic field. From density functional theory calculations,
+we determine a likely set of magnetic exchange constants. Incorporating these
+constants into a minimal Hamiltonian model of our material, we find that the
+plateau and of the $Z_3$ symmetry breaking ground state both arise from
+interplane and intraplane antiferromagnetic interactions acting in competition.
+These findings are pertinent to the magneto-electric properties of
+Fe$_{1/3}$NbS$_2$, which allow electrical switching of antiferromagnetic
+textures at relatively low current densities.",2002.02960v2
+2020-04-09,Magnetic field-dependent resistance crossover and logarithmic to non-saturating magnetoresistance in topological insulator Bi$_2$Te$_3$,"We report a metal-insulator like transition in single crystalline 3D
+topological insulator Bi2Te3 at a temperature of 230K in presence of an
+external magnetic field applied normal to the surface. This transition becomes
+more prominent at larger magnetic field strength with the residual resistance
+value increasing linearly with the magnetic field. At low temperature, the
+magnetic field dependence of the magnetoresistance shows a transition from
+logarithmic to linear behavior and the onset magnetic field value for this
+transition decreases with increasing temperature. The logarithmic
+magnetoresistance indicates the weak anti-localization of the surface Dirac
+electrons while the high temperature behavior originates from the bulk carriers
+due to intrinsic impurities. At even higher temperatures beyond~230 K, a
+completely classical Lorentz model type quadratic behavior of the
+magnetoresistance is observed. We also show that the experimentally observed
+anomalies at ~230K in the magneto-transport properties do not originate from
+any stacking fault in Bi2Te3.",2004.04375v2
+2020-04-14,High-intensity pulsed ion beam treatment of amorphous iron-based metal alloy,"Abstract The results of intense pulsed ion beam (IPIB) treatment of the soft
+magnetic amorphous alloy of a FINEMET-type are presented. Foil produced from
+the alloy was irradiated with short (about 100 ns) pulses of carbon ions and
+protons with energy of up to 300 keV and an energy density of up to 7 J/cm2.
+X-ray diffraction, M\""ossbauer spectroscopy and magnetic measurements were used
+to investigate structural and magnetic properties of irradiated foils. It is
+shown that the foil remains intact after the treatment, and the crystal
+structure still amorphous. Spontaneous magnetization vector is found to lie
+almost along perpendicular to the foil plane after irradiation, whereas for the
+initial amorphous foil it belongs to the plane. The magnetic properties of the
+foil undergo changes: the coercive force decreases, the saturation induction
+increases slightly, and the magnetization curve has shallower slope.",2004.06410v1
+2021-02-04,Classical Spin Liquid State in the $S=\frac{5}{2}$ Heisenberg Kagomé Antiferromagnet Li$_9$Fe$_3$(P$_2$O$_7$)$_3$(PO$_4$)$_2$,"We investigate the low temperature magnetic properties of a $S=\frac{5}{2}$
+Heisenberg kagom\'e antiferromagnet, the layered monodiphosphate
+Li$_9$Fe$_3$(P$_2$O$_7$)$_3$(PO$_4$)$_2$, using magnetization measurements and
+$^{31}$P nuclear magnetic resonance. An antiferromagnetic-type order sets in at
+$T_{\rm N}=1.3$ K and a characteristic magnetization plateau is observed at 1/3
+of the saturation magnetization below $T^* \sim 5$ K. A moderate $^{31}$P NMR
+line broadening reveals the development of anisotropic short-range correlations
+within the plateau phase concomitantly with a gapless spin-lattice relaxation
+time $T_1 \sim k_B T / \hbar S$, which both point to the presence of a
+semiclassical nematic spin liquid state predicted for the Heisenberg kagom\'e
+antiferromagnetic model or to the persistence of the zero-energy modes of the
+kagome lattice under large magnetic fields.",2102.02882v2
+2021-03-26,Schwinger pair production of magnetic monopoles: momentum distribution for heavy-ion collisions,"Magnetic monopoles may be produced by the dual Schwinger effect in strong
+magnetic fields. Today, the strongest known magnetic fields in the universe are
+produced fleetingly in heavy-ion collisions. We use the complex worldline
+instanton method to calculate the momentum distribution of magnetic monopoles
+produced in heavy-ion collisions, in an approximation that includes the effect
+of the magnetic field to all orders but neglects monopole self-interactions.
+The result saturates the preparation time-energy uncertainty principle, and
+yields a necessary ingredient for experimental monopole searches in heavy-ion
+collisions.",2103.14454v2
+2021-04-05,Competing ferromagnetic and antiferromagnetic interactions drive the magnetocaloric tunability in Gd55Co30NixAl15-x microwires,"We have employed Gd55Co30NixAl15-x (x = 10, 5 and 0) amorphous microwires as
+a model system to unravel the impact of multiple magnetic interactions on the
+magnetism and the magnetocaloric behavior in Gd-alloy microwire systems. Our
+study shows that in addition to the RKKY ferromagnetic (FM) interaction
+(Gd-Gd), antiferromagnetic (AFM) interactions (Gd-Co, Gd-Ni) coexist and
+contribute to the magnetic and magnetocaloric response of the system. The
+dilution effect of Al element on the FM Gd-Gd interaction is responsible for
+the decrease of the Curie temperature (TC), whereas the increase of the
+saturation magnetization (MS) is originated from the reduced AFM Gd-Ni
+interaction. A thorough analysis of critical exponents suggests that the
+presence of the AFM interactions hinders the system to exhibit a long-range FM
+order below the TC. Adjusting these interactions is shown to preserve the large
+refrigerant capacity (RC) while tuning the TC over a wide temperature range,
+which is desirable for active magnetic refrigeration.",2104.01790v1
+2021-05-20,Rectangle-like hysteresis in a Dysprosium Metallacrown Magnet with Linear F-Dy-F Anisotropic Moiety,"Single-molecule magnets (SMMs) exhibiting open hysteresis loops may
+potentially apply to molecule-based information processing and storage.
+However, the capacity to retain magnetic memory is always limited by zero-field
+quantum tunneling of magnetization (QTM). Herein, a well-designed dysprosium
+metallacrown SMM, consisting of an endohedral approximate linear F-Dy-F strong
+anisotropic moiety in a peripheral [15-MCNi-5] metallacrown (MC), is reported
+with the largest reversal barrier of 1060 cm-1 among d-f SMMs. Rectangle-like
+hysteresis loops are observed with the huge squareness (remanence/saturation
+magnetization) up to 97% at 2 K. More importantly, zero-field QTM step is
+phenomenologically removed by minimizing the dipole coupling and hyperfine
+interactions. The results demonstrate for the first time that zero-field QTM
+step can be eliminated via manipulating the ligand field and vanishing the
+external magnetic perturbations, which illuminates a promising blueprint for
+developing high-performance SMMs.",2105.09586v1
+2021-09-03,Magnetization Plateaus of a Double Fullerene Core/Shell Like-Nanostructure in an External Magnetic Field: Monte Carlo Study,"This paper concerns the investigation of the critical (HC) and the saturation
+(HS) magnetic fields behavior of the studied system as a function of different
+physical parameters. The Monte Carlo method has been used to study the magnetic
+properties of a ferrimagnetic behavior of a double fullerene X60 core/shell
+like-nanostructure, where the symbol X can be assigned to any magnetic atom.
+Based on the Ising model, we focus our study on a system formed by a double
+sphere core/shell. The two spheres are containing the spins: $\sigma=\pm 1/2$
+in the core are surrounded by the spin $S=\pm 1, 0$ in the shell. Many types of
+magnetization curves have been found, depending on the competitions among the
+exchange couplings, the crystal fields and the temperature.",2109.01453v1
+2021-09-14,Quantum magnetism of ferromagnetic spin dimers in $α$-KVOPO$_4$,"Magnetism of the spin-$\frac12$ $\alpha$-KVOPO$_4$ is studied by
+thermodynamic measurements, $^{31}$P nuclear magnetic resonance (NMR), neutron
+diffraction, and density-functional band-structure calculations. Ferromagnetic
+Curie-Weiss temperature of $\theta_{\rm CW}\simeq 15.9$ K and the saturation
+field of $\mu_0H_s\simeq 11.3$ T suggest the predominant ferromagnetic coupling
+augmented by a weaker antiferromagnetic exchange that leads to a short-range
+order below 5 K and the long-range antiferromagnetic order below $T_{\rm
+N}\simeq 2.7$ K in zero field. Magnetic structure with the propagation vector
+$\mathbf k=(0,\frac12,0)$ and the ordered magnetic moment of 0.58 $\mu_B$ at
+1.5 K exposes a non-trivial spin lattice where strong ferromagnetic dimers are
+coupled antiferromagnetically. The reduction in the ordered magnetic moment
+with respect to the classical value (1 $\mu_{\rm B}$) indicates sizable quantum
+fluctuations in this setting, despite the predominance of ferromagnetic
+exchange. We interpret this tendency toward ferromagnetism as arising from the
+effective orbital order in the folded chains of the VO$_6$ octahedra.",2109.06840v1
+2021-09-15,Confining and chiral properties of QCD in extremely strong magnetic fields,"We investigate, by numerical lattice simulations, the static quark-antiquark
+potential, the flux tube properties and the chiral condensate for $N_f = 2+1$
+QCD with physical quark masses in the presence of strong magnetic fields, going
+up to $eB = 9$ GeV$^2$, with continuum extrapolated results. The string tension
+for quark-antiquark separations longitudinal to the magnetic field is
+suppressed by one order of magnitude at the largest explored magnetic field
+with respect to its value at zero magnetic background, but is still
+non-vanishing; in the transverse direction, instead, the string tension is
+enhanced but seems to reach a saturation at around 50 % of its value at $B =
+0$. The flux tube shows a consistent suppression/enhancement of the overall
+amplitude, with mild modifications of its profile. Finally, we observe magnetic
+catalysis in the whole range of explored fields with a behavior compatible with
+a lowest Landau level approximation, in particular with a linear dependence of
+the chiral condensate on $B$ which is in agreement, within errors, with that
+already observed for $eB \sim 1$ GeV$^2$.",2109.07456v2
+2021-11-29,Current driven kink instabilities in relativistic jets: dissipation properties,"We analyze the evolution of current driven kink instabilities of a highly
+magnetized relativistic plasma column, focusing in particular on its
+dissipation properties. The instability evolution leads to the formation of
+thin current sheets where the magnetic energy is dissipated. We find that the
+total amount of dissipated magnetic energy is independent of the dissipation
+properties. Dissipation occurs in two stages: a peak when the instability
+saturates, which is characterized by the formation of a helicoidal current
+sheet at the boundary of the deformed plasma column, followed by a weaker
+almost flat phase, in which turbulence develops. The detailed properties of
+these two phases depend on the equilibrium configuration and other parameters,
+in particular on the steepness of the pitch radial profile, on the presence of
+an external axial magnetic field and on the amount of magnetization. These
+results are relevant for high energy astrophysical sources, since current
+sheets can be the sites of magnetic reconnection where particles can be
+accelerated to relativistic energies and give rise to the observed radiation.",2111.14575v1
+2021-12-21,Magnetically tunable Shubnikov-de Hass oscillations in MnBi2Te4,"Shubnikov-de Hass oscillations are directly observed in undoped
+antiferromagnetic topological insulator MnBi2Te4. With increasing magnetic
+fields, the oscillation period decreases gradually in the magnetic transition
+from canted antiferromagnetism to ferromagnetism and then saturates in high
+magnetic fields, indicating the field-induced evolution of the band structure.
+From the analysis of the high-field oscillations, a nontrivial Berry phase and
+a small effective mass are extracted, in agreement with the predicted Weyl
+semimetal phase in ferromagnetic MnBi2Te4. Furthermore, rotating the
+magnetization of MnBi2Te4 can lead to a splitting of the high-field
+oscillations, which suggests the enhanced asymmetry of the Weyl cones in tilted
+fields. Therefore, the observation of these magnetically tunable quantum
+oscillations clearly demonstrates the indispensable role of field in tuning the
+band structure or physical properties of MnBi2Te4.",2112.10962v1
+2021-12-23,Control of site occupancy by variation of the Zn and Al content in NiZnAl ferrite epitaxial films with low magnetic damping,"The structural and magnetic properties of Zn/Al doped nickel ferrite thin
+films can be adjusted by changing the Zn and Al content. The films are
+epitaxially grown by reactive magnetron sputtering using a triple cluster
+system to sputter simultaneously from three different targets. Upon the
+variation of the Zn content the films remain fully strained with similar
+structural properties, while the magnetic properties are strongly affected. The
+saturation magnetization and coercivity as well as resonance position and
+linewidth from ferromagnetic resonance (FMR) measurements are altered depending
+on the Zn content in the material. The reason for these changes can be
+elucidated by investigation of the x-ray magnetic circular dichroism spectra to
+gain site and valence specific information with elemental specificity.
+Additionally, from a detailed investigation by broadband FMR a minimum in
+g-factor and linewidth could be found as a function of film thickness.
+Furthermore, the results from a variation of the Al content using the same set
+of measurement techniques is given. Other than for Zn, the variation of Al
+affects the strain and even more pronounced changes to the magnetic properties
+are apparent.",2112.12456v1
+2022-01-31,Anomalous Nernst effect in La0.5Ca0.5Coo3,"We report the occurrence of the anomalous Nernst effect (ANE) in
+polycrystalline perovskite La0.5Ca0.5CoO3. The sample is ferromagnetic below TC
+= 147 K and resistivity shows non-metallic behavior above and below the TC with
+only a small negative magnetoresistance (~2%) around TC. Field dependence of
+magnetization at 10 K shows large hysteresis with a coercive field of 6 kOe but
+a small magnetization ~ 0.64 Bohr magneton/Co even in a field of 50 kOe, which
+indicates the presence of magnetically heterogeneous ground state consisting of
+ferromagnetic and non-ferromagnetic phases. The field dependence of the Nernst
+thermopower (Sxy) at low temperatures shows complete saturation but the
+magnetization does not. This indicates that the ANE in La0.5Ca0.5CoO3 depends
+only on the transport properties of the ferromagnetic phase, while it is not
+affected by the non-ferromagnetic phase. Due to the higher value of remnant
+Sxy, the magnetized polycrystalline sample exhibits ANE in absence of an
+external magnetic field.",2201.12982v1
+2022-04-22,Resistive instabilities in sinusoidal shear flows with a streamwise magnetic field,"We investigate the linear stability of a sinusoidal shear flow with an
+initially uniform streamwise magnetic field in the framework of incompressible
+magnetohydrodynamics (MHD) with finite resistivity and viscosity. This flow is
+known to be unstable to the Kelvin-Helmholtz instability in the hydrodynamic
+case. The same is true in ideal MHD, where dissipation is neglected, provided
+the magnetic field strength does not exceed a critical threshold beyond which
+magnetic tension stabilizes the flow. Here, we demonstrate that including
+viscosity and resistivity introduces two new modes of instability. One of these
+modes, which we call a resistively-unstable Alfv\'en wave due to its connection
+to shear Alfv\'en waves, exists for any nonzero magnetic field strength as long
+as the magnetic Prandtl number $Pm < 1$. We present a reduced model for this
+instability that reveals its excitation mechanism to be the negative eddy
+viscosity of periodic shear flows described by Dubrulle & Frisch (1991).
+Finally, we demonstrate numerically that this mode saturates in a
+quasi-stationary state dominated by counter-propagating solitons.",2204.10875v1
+2022-06-23,Primordial magnetic fields in Population III star formation: a magnetised resolution study,"Population III stars form in groups due to the fragmentation of primordial
+gas. While uniform magnetic fields have been shown to support against
+fragmentation in present day star formation, it is unclear whether realistic
+k^3/2 primordial fields can have the same effect. We bypass the issues
+associated with simulating the turbulent dynamo by introducing a saturated
+magnetic field at equipartition with the velocity field when the central
+densities reaches 10-13 g cm-3. We test a range of sink particle creation
+densities from 10-10-10-8 g cm-3. Within the range tested, the fields did not
+suppress fragmentation of the gas and hence could not prevent the degree of
+fragmentation from increasing with increased resolution. The number of sink
+particles formed and total mass in sink particles was unaffected by the
+magnetic field across all seed fields and resolutions. The magnetic pressure
+remained sub-dominant to the gas pressure except in the highest density regions
+of the simulation box, where it became equal to but never exceeded gas
+pressure. Our results suggest that the inclusion of magnetic fields in
+numerical simulations of Pop III star formation is largely unimportant.",2206.11919v1
+2022-11-16,BPS solitons with internal structures in a restricted baby Skyrme-Maxwell theory in a magnetic medium,"We consider a restricted baby Skyrme-Maxwell scenario enlarged via the
+inclusion of a nontrivial magnetic permeability. We then proceed with the
+minimization of its total energy by means of the Bogomol'nyi-Prasad-Sommerfield
+(BPS) prescription, from which we get that the self-dual potential now depends
+on the magnetic permeability itself. As a result, we obtain not only the lower
+bound for the energy, but also the self-dual equations whose solutions saturate
+that bound. In such a context, we focus our attention on those time-independent
+gauged skyrmions with radial symmetry and no electric charge. We solve the
+effective self-dual equations numerically for different choices of the magnetic
+permeability, from which we obtain BPS magnetic fields whose internal
+structures form concentric rings. We also explain analytically the formation of
+these structures based on the values of a single real parameter which
+characterizes the respective magnetic permeabilities.",2211.09216v1
+2023-03-03,Magneto-optical sensing of the pressure driven magnetic ground states in bulk CrSBr,"Competition between exchange interactions and magnetocrystalline anisotropy
+may bring new magnetic states that are of great current interest. An applied
+hydrostatic pressure can further be used to tune their balance. In this work we
+investigate the magnetization process of a biaxial antiferromagnet in an
+external magnetic field applied along the easy axis. We find that the single
+metamagnetic transition of the Ising type observed in this material under
+ambient pressure transforms under hydrostatic pressure into two transitions, a
+first-order spin flop transition followed by a second order transition towards
+a polarized ferromagnetic state near saturation. This reversible tuning into a
+new magnetic phase is obtained in layered bulk CrSBr at low temperature by
+varying the interlayer distance using high hydrostatic pressure, which
+efficiently acts on the interlayer magnetic exchange, and is probed by
+magneto-optical spectroscopy.",2303.01823v2
+2023-06-01,Structural Trends and Itinerant Magnetism of the New Cage-structured Compound HfMn$_{2}$Zn$_{20}$,"A new cage-structured compound - HfMn$_{2}$Zn$_{20}$ - belonging to the
+AB$_{2}$C$_{20}$ (A, B = transition or rare earth metals, and C = Al, Zn, or
+Cd) family of structures has been synthesized via the self-flux method. The new
+compound crystallizes in the space group Fd-3m with lattice parameter a =
+14.0543(2) \r{A} (Z = 8) and exhibits non-stoichiometry due to Mn/Zn mixing on
+the Mn-site and an underoccupied Hf-site. The structure refines to
+Hf$_{0.93}$Mn$_{1.63}$Zn$_{20.37}$ and follows lattice size trends when
+compared to other HfM$_{2}$Zn$_{20}$ (M = Fe, Co, and Ni) structures. The
+magnetic measurements show that this compound displays a modified Curie-Weiss
+behavior with a transition temperature around 22 K. The magnetization shows no
+saturation, a small magnetic moment, and near negligible hysteresis, all signs
+of the itinerant magnetism. The Rhodes-Wohlfarth ratio and the spin fluctuation
+parameters ratio both confirm the itinerant nature of the magnetism in
+HfMn$_{2}$Zn$_{20}$.",2306.01146v3
+2023-10-16,Emergent spin-gapped magnetization plateaus in a spin-1/2 perfect kagome antiferromagnet,"The two-dimensional (2D) spin-1/2 kagome Heisenberg antiferromagnet is
+believed to host quantum spin liquid (QSL) states with no magnetic order, but
+its ground state remains largely elusive. An important outstanding question
+concerns the presence or absence of the 1/9 magnetization plateau, where exotic
+quantum states, including topological ones, are expected to emerge. Here we
+report the magnetization of a recently discovered kagome QSL candidate
+YCu$_3$(OH)$_{6.5}$Br$_{2.5}$ up to 57 T. Above 50 T, a clear magnetization
+plateau at 1/3 of the saturation moment of Cu$^{2+}$ ions is observed,
+supporting that this material provides an ideal platform for the kagome
+Heisenberg antiferromagnet. Remarkably, we found another magnetization plateau
+around 20 T, which is attributed to the 1/9 plateau. The temperature dependence
+of this plateau reveals the distinct spin gap, whose magnitude estimated by the
+plateau width is approximately 10% of the exchange interaction. The observation
+of 1/9 and 1/3 plateaus highlights the emergence of novel states in quantum
+spin systems.",2310.10069v1
+2005-08-24,Shearing Box Simulations of the MRI in a Collisionless Plasma,"We describe local shearing box simulations of turbulence driven by the
+magnetorotational instability (MRI) in a collisionless plasma. Collisionless
+effects may be important in radiatively inefficient accretion flows, such as
+near the black hole in the Galactic Center. The MHD version of ZEUS is modified
+to evolve an anisotropic pressure tensor. A fluid closure approximation is used
+to calculate heat conduction along magnetic field lines. The anisotropic
+pressure tensor provides a qualitatively new mechanism for transporting angular
+momentum in accretion flows (in addition to the Maxwell and Reynolds stresses).
+We estimate limits on the pressure anisotropy due to pitch angle scattering by
+kinetic instabilities. Such instabilities provide an effective ``collision''
+rate in a collisionless plasma and lead to more MHD-like dynamics. We find that
+the MRI leads to efficient growth of the magnetic field in a collisionless
+plasma, with saturation amplitudes comparable to those in MHD. In the saturated
+state, the anisotropic stress is comparable to the Maxwell stress, implying
+that the rate of angular momentum transport may be moderately enhanced in a
+collisionless plasma.",0508502v2
+2006-04-21,Flux-transport dynamos with Lorentz force feedback on differential rotation and meridional flow: Saturation mechanism and torsional oscillations,"In this paper we discuss a dynamic flux-transport dynamo model that includes
+the feedback of the induced magnetic field on differential rotation and
+meridional flow. We consider two different approaches for the feedback:
+meanfield Lorentz force and quenching of transport coefficients such as
+turbulent viscosity and heat conductivity. We find that even strong feedback on
+the meridional flow does not change the character of the flux-transport dynamo
+significantly; however it leads to a significant reduction of differential
+rotation. To a large degree independent from the dynamo parameters, the
+saturation takes place when the toroidal field at the base of the convection
+zone reaches between 1.2 an 1.5 T, the energy converted intomagnetic energy
+corresponds to about 0.1 to 0.2% of the solar luminosity. The torsional
+oscillations produced through Lorentz force feedback on differential rotation
+show a dominant poleward propagating branch with the correct phase relation to
+the magnetic cycle. We show that incorporating enhanced surface cooling of the
+active region belt (as proposed by Spruit) leads to an equatorward propagating
+branch in good agreement with observations.",0604446v2
+1999-08-31,NMR Detection of Temperature-Dependent Magnetic Inhomogeneities in URu2Si2,"We present 29Si-NMR relaxation and spectral data in URu2Si2. Our echo-decay
+experiments detect slowly fluctuating magnetic field gradients. In addition, we
+find that the echo-decay shape (time dependence) varies with temperature T and
+its rate behaves critically near the Neel temperature TN, indicating a
+correlation between the gradient fluctuations and the transition to
+small-moment order. T-dependent broadening contributions become visible below
+100 Kelvin and saturate somewhat above TN, remaining saturated at lower
+temperatures. Together, the line width and shift suggest partial lattice
+distortions below TN. We propose an intrinsic minority phase below $T_{\rm N}$
+and compare our results with one of the current theoretical models.",9908460v1
+2000-03-21,Field induced ordering in highly frustrated antiferromagnets,"We predict that an external field can induce a spin order in highly
+frustrated classical Heisenberg magnets. We find analytically stabilization of
+collinear states by thermal fluctuations at a one-third of the saturation field
+for kagome and garnet lattices and at a half of the saturation field for
+pyrochlore and frustrated square lattices. This effect is studied numerically
+for the frustrated square-lattice antiferromagnet by Monte Carlo simulations
+for classical spins and by exact diagonalization for $S=1/2$. The field induced
+collinear states have a spin gap and produce magnetization plateaus.",0003343v2
+2000-04-12,Weak anisotropy and disorder dependence of the in-plane magnetoresistance in high mobility (100) Si-inversion layers,"We report studies of the magnetoresistance (MR) in a two-dimensional electron
+system in (100) Si-inversion layers, for perpendicular and parallel
+orientations of the current with respect to the magnetic field in the 2D-plane.
+The magnetoresistance is almost isotropic; this result does not support the
+suggestion of the orbital origin of the MR in Si-inversion layer. In the
+hopping regime, however, the MR contains a weak anisotropic component that is
+non-monotonic in magnetic field. We found that the field, at which the MR
+saturates, for different samples varies by a factor of two, being lower or
+higher than the field of complete spin polarization of free carriers.
+Therefore, the saturation of the MR can not be identified with the spin
+polarization of free carriers.",0004206v3
+2000-06-22,Magnetoresistance of Three-Constituent Composites: Percolation Near a Critical Line,"Scaling theory, duality symmetry, and numerical simulations of a random
+network model are used to study the magnetoresistance of a
+metal/insulator/perfect conductor composite with a disordered columnar
+microstructure. The phase diagram is found to have a critical line which
+separates regions of saturating and non-saturating magnetoresistance. The
+percolation problem which describes this line is a generalization of
+anisotropic percolation. We locate the percolation threshold and determine the
+t = s = 1.30 +- 0.02, nu = 4/3 +- 0.02, which are the same as in
+two-constituent 2D isotropic percolation. We also determine the exponents which
+characterize the critical dependence on magnetic field, and confirm numerically
+that nu is independent of anisotropy. We propose and test a complete scaling
+description of the magnetoresistance in the vicinity of the critical line.",0006338v3
+2001-03-21,Magneto-transport Properties near the Superconductor-Insulator Transition in 2D,"We analyze here the behavior near the 2D insulator-superconductor quantum
+critical point in the presence of a perpendicular magnetic field. We show that
+with increasing field $H$, the quantum disordered and quantum critical regimes,
+in which vortex degrees of freedom are suppressed, crossover to a new
+magnetically activated (MA) regime, where the correlation length $\xi \sim
+1/\sqrt{H}$. In this regime, we show that the conductivity decreases
+monotonically as opposed to the anticipated saturation predicted from
+hyperuniversality arguments. This discrepancy arises from the lack of
+commutativity of the frequency and temperature tending to zero limits of the
+conductivity. In the low-field regime such that $\sqrt{H}\ll\Delta$, and in the
+absence of Ohmic dissipation, where $\Delta$ is a measure of the distance from
+the quantum critical point, the resistivity saturates to the Bose metal value
+found previously for Cooper pairs lacking phase coherence.",0103433v2
+2001-09-26,Ferromagnetic Domain Walls in finite systems: mean-field critical exponents and applications,"The distribution of magnetic moments in finite ferromagnetic bodies was first
+investigated by Landau and Lifshitz in a famous paper [\textit{Phys. Z. Soviet
+Union}, \textbf{8}, 153 (1935)], where they obtained the domain structure of a
+ferromagnetic crystal at low temperatures, in the regime of saturated
+magnetization. In this article, we investigate the general properties of
+ferromagnetic domain walls of uniaxial crystals from the view point of the
+Landau free energy. We present the basic ideas at an introductory level, for
+non-experts. Extending the formalism to the vicinity of the Curie temperature,
+where a general qualitative description by the Landau theory of phase
+transitions can be applied, we find that domain walls tend to suppress the
+layers, leading to a continuous vanishing of the domain structure with
+anomalous critical exponents. In the saturated regime, we discuss the role of
+domain walls in mesoscopic systems and ferromagnetic nanojunctions, relating
+the observed magnetoresistance with promising applications in the recent area
+of spintronics.",0109499v2
+2001-10-11,The Parallel Magnetoconductance of Interacting Electrons in a Two Dimensional Disordered System,"The transport properties of interacting electrons for which the spin degree
+of freedom is taken into account are numerically studied for small two
+dimensional diffusive clusters. On-site electron-electron interactions tend to
+delocalize the electrons, while long-range interactions enhance localization.
+On careful examination of the transport properties, we reach the conclusion
+that it does not show a two dimensional metal insulator transition driven by
+interactions. A parallel magnetic field leads to enhanced resistivity, which
+saturates once the electrons become fully spin polarized. The strength of the
+magnetic field for which the resistivity saturates decreases as electron
+density goes down. Thus, the numerical calculations capture some of the
+features seen in recent experimental measurements of parallel
+magnetoconductance.",0110235v1
+2003-05-08,Photoemission spectra of a two-dimensional S=1/2 quantum antiferromagnet in magnetic fields: a theoretical study,"We calculate the angular resolved photoemission spectra (ARPES) of a spin-1/2
+Heisenberg antiferromagnet as a function of magnetic fields using both the
+exact diagonalization method and self-consistent Born approximation. Below the
+saturation field $B_C$, strong scattering between spin waves and a hole,
+created by photoemission of an electron, significantly narrows the
+quasiparticle band that is characterized by the lowering of the quasiparticle
+energy at $(\pi,\pi)$ with increasing field. Accordingly, in ARPES the
+quasiparticle peak gets shaper near $(\pi,\pi)$ and broader elsewhere.
+Furthermore, we observe that an anomalous extended van Hove region (EVHR)
+around $(\pi,\pi)$ appears in a half saturation field, while EVHRs around
+$(\pi,0)$ and $(0,\pi)$ in zero field gradually disappear with increasing
+field.",0305174v1
+2004-04-22,Magnetocaloric effect in pyrochlore antiferromagnet Gd2Ti2O7,"An adiabatic demagnetization process is studied in Gd2Ti2O7, a geometrically
+frustrated antiferromagnet on a pyrochlore lattice. In contrast to conventional
+paramagnetic salts, this compound can exhibit a temperature decrease by a
+factor of ten in the temperature range below the Curie-Weiss constant. The most
+efficient cooling is observed in the field interval between 120 and 60 kOe
+corresponding to a crossover between saturated and spin-liquid phases. This
+phenomenon indicates that a considerable part of the magnetic entropy survives
+in the strongly correlated state. According to the theoretical model, this
+entropy is associated with a macroscopic number of local modes remaining
+gapless till the saturation field. Monte Carlo simulations on a classical spin
+model demonstrate good agreement with the experiment. The cooling power of the
+process is experimentally estimated with a view to possible technical
+applications. The results for Gd2Ti2O7 are compared to those for Gd3Ga5O12, a
+well-known material for low temperature magnetic refrigeration.",0404529v2
+2004-11-26,Metastable states and T=0 hysteresis in the random-field Ising model on random graphs,"We study the ferromagnetic random-field Ising model on random graphs of fixed
+connectivity z (Bethe lattice) in the presence of an external magnetic field
+$H$. We compute the number of single-spin-flip stable configurations with a
+given magnetization m and study the connection between the distribution of
+these metastable states in the H-m plane (focusing on the region where the
+number is exponentially large) and the shape of the saturation hysteresis loop
+obtained by cycling the field between $-\infty$ and $+\infty$ at T=0. The
+annealed complexity $\Sigma_A(m,H)$ is calculated for z=2,3,4 and the quenched
+complexity $\Sigma_Q(m,H)$ for z=2. We prove explicitly for z=2 that the
+contour $\Sigma_Q(m,H)=0$ coincides with the saturation loop. On the other
+hand, we show that $\Sigma_A(m,H)$ is irrelevant for describing, even
+qualitatively, the observable hysteresis properties of the system.",0411677v2
+2006-02-26,Strong temperature dependence of antiferromagnetic coupling in CoFeB/Ru/CoFeB,"The temperature dependence of saturation and spin-flop fields for artificial
+ferrimagnets (AFi) based on antiparallel coupled CoFeB/Ru/CoFeB trilayers has
+been investigated in a temperature range between 80K and 600K. The results
+presented in this paper are relevant for magnetic devices using this system,
+e.g. magnetic-random access memory based on spin-flop switching. In good
+accordance to the theory, the saturation field Hsat behaves like Hsat ~ H_0
+(T/T_0)/sinh(T/T_0) with a characteristic temperature of T_0 = 150K. Within
+this model, the Fermi velocity for the Ru layer is of the order of 10^5m/s,
+therefore, explaining the strong variation of the coupling strength with the
+temperature in Ru based AFi. Furthermore, a strong uniaxial anisotropy of K_u =
+2x10^3 J/m^3 with a small angular distribution of the anisotropy axes is
+observed for the AFi trilayers based on amorphous CoFeB alloys.",0602609v2
+1995-04-21,``GLUELUMP'' SPECTRUM AND ADJOINT SOURCE POTENTIAL IN LATTICE QCD$_3$,"We calculate the potential between ``quarks'' which are in the adjoint
+representation of SU(2) color in the three-dimensional lattice theory. We work
+in the scaling region of the theory and at large quark separations $R$. We also
+calculate the masses $M_{Qg}$ of color-singlet bound states formed by coupling
+an adjoint quark to adjoint glue (``gluelumps''). Good scaling behavior is
+found for the masses of both magnetic (angular momentum $J=0$) and electric
+($J=1$) gluelumps, and the magnetic gluelump is found to be the lowest-lying
+state. It is naively expected that the potential for adjoint quarks should
+saturate above a separation $R_{\rm scr}$ where it becomes energetically
+favorable to produce a pair of gluelumps. We obtain a good estimate of the
+naive screening distance $R_{\rm scr}$. However we find little evidence of
+saturation in the potential out to separations $R$ of about twice $R_{\rm
+scr}$.",9504015v1
+1994-02-01,Strong-Weak Coupling Duality in Four Dimensional String Theory,"We present several pieces of evidence for strong-weak coupling duality
+symmetry in the heterotic string theory, compactified on a six dimensional
+torus. These include symmetry of the 1) low energy effective action, 2) allowed
+spectrum of electric and magnetic charges in the theory, 3) allowed mass
+spectrum of particles saturating the Bogomol'nyi bound, and 4) Yukawa couplings
+between massless neutral particles and massive charged particles saturating the
+Bogomol'nyi bound. This duality transformation exchanges the electrically
+charged elementary string excitations with the magnetically charged soliton
+states in the theory. It is shown that the existence of a strong-weak coupling
+duality symmetry in four dimensional string theory makes definite prediction
+about the existence of new stable monopole and dyon states in the theory with
+specific degeneracies, including certain supersymmetric bound states of
+monopoles and dyons. The relationship between strong-weak coupling duality
+transformation in string theory and target space duality transformation in the
+five-brane theory is also discussed. (Based on a talk given at the workshop on
+Strings and Gravity, Madras, India.)",9402002v2
+2002-05-08,The alpha effect and its saturation in a turbulent swirling flow generated in the VKS experiment,"We report the experimental observation of the alpha-effect. It consists in
+the generation of a current parallel to a magnetic field B0 applied to a
+turbulent swirling flow of liquid sodium. At low magnetic Reynolds number, Rm,
+we show that the magnitude of the alpha-effect increases like Rm2 and that its
+sign is determined by the flow helicity. It saturates and then decreases at
+large Rm, primarily because of the expulsion of the applied field B0 from the
+bulk of the flow. We show how this expulsion is affected by the flow geometry
+by varying the relative amplitudes of the azimuthal and axial flows.",0205019v1
+2004-12-08,Zero-Temperature Theory of Collisionless Rapid Adiabatic Passage from a Fermi Degenerate Gas of Atoms to a Bose-Einstein Condensate of Molecules,"We theoretically examine a zero-temperature system of Fermi degenerate atoms
+coupled to bosonic molecules via collisionless rapid adiabatic passage across a
+Feshbach resonance, focusing on saturation of the molecular conversion
+efficiency at the slowest magnetic-field sweep rates. Borrowing a novel
+MANY-FERMION Fock-state theory, we find that a proper model of the
+magnetic-field sweep can systematically remove saturation. We also debunk the
+common misconception that many-body effects are responsible for molecules
+existing above the two-body threshold.",0412048v2
+2009-06-25,Frustration Driven Stripe Domain Formation in Co/Pt Multilayer Films,"We report microscopic mechanisms for an unusual magnetization reversal
+behavior in Co/Pt multilayers where some of the first-order reversal curves
+protrude outside of the major loop. Transmission x-ray microscopy reveals a
+fragmented stripe domain topography when the magnetic field is reversed prior
+to saturation, in contrast to an interconnected pattern when reversing from a
+saturated state. The different domain nucleation and propagation behaviors are
+due to unannihilated domains from the prior field sweep. These residual domains
+contribute to random dipole fields that impede the subsequent domain growth and
+prevent domains from growing as closely together as for the interconnected
+pattern.",0906.4744v1
+2009-07-02,Thermal expansion of the spin-1/2 Heisenberg-chain compound Cu(C$_4$H$_4$N$_2$)(NO$_3$)$_2$,"Compounds containing magnetic subsystems representing simple model spin
+systems with weak magnetic coupling constants are ideal candidates to test
+theoretical predictions for the generic behavior close to quantum phase
+transitions. We present measurements of the thermal expansion and
+magnetostriction of the spin-1/2-chain compound copper pyrazine dinitrate
+Cu(C$_4$H$_4$N$_2$)(NO$_3$)$_2$. Of particular interest is the low-temperature
+thermal expansion close to the saturation field $H_c \simeq 13.9 \mathrm{T}$,
+which defines a quantum phase transition from the gapless Luttinger liquid
+state to the fully saturated state with a finite excitation gap. We observe a
+sign change of the thermal expansion for the different ground states, and at
+the quantum critical point $H_c$ the low-temperature expansion approaches a
+$1/\sqrt{T}$ divergence. Thus, our data agree very well with the expected
+quantum critical behaviour.",0907.0400v1
+2009-07-08,On the theory of astronomical maser. II. Polarization of maser radiation,"In this paper we investigate the polarization property of the radiation
+amplified by astronomical masers in the presence of a strong magnetic field.
+Our model explicitly takes into account the broadband nature of the radiation
+field and the interaction of the radiation with the maser transition J=1--0.
+The amplification of different realisations of the background continuum
+radition by the maser is directly simulated and the Stokes parameters of the
+radiation field are then obtained by averaging over the ensemble of emerging
+maser radiation. For isotropic pumping and partially saturated masers we find
+that the maser radiation is linearly polarized in two representative cases
+where the magnetic field {\bf B} makes an angle $\theta$=30$^0$ and
+$\theta$=90$^0$ to the maser axis. The linear polarization for maser radiation
+obtained in our simulations for both cases are in agreement with the results of
+the standard model. Furthermore, no instability during amplification is seen in
+our simulations. Therefore, we conclude that there is no problem with the
+previous numerical investigations of maser polarization in the unsaturated and
+partially saturated regime.",0907.1327v1
+2010-01-05,Radiative Signatures of Relativistic Shocks,"(Abbreviated) Particle-in-cell simulations of relativistic, weakly magnetized
+collisionless shocks show that particles can gain energy by repeatedly crossing
+the shock front. This requires scattering off self-generated small length-scale
+magnetic fluctuations. The radiative signature of this first-order Fermi
+acceleration mechanism is important for models of both the prompt and afterglow
+emission in gamma-ray bursts and depends on the strength parameter ""a"" of the
+fluctuations. For electrons (and positrons), acceleration saturates when the
+radiative losses produced by the scattering cannot be compensated by the energy
+gained on crossing the shock. We show that this sets an upper limit on both the
+electron Lorentz factor and on the energy of the photons radiated during the
+scattering process. This rules out ""jitter"" radiation on self-excited
+fluctuations with a < 1 as a source of gamma-rays, although high-energy photons
+might still be produced when the jitter photons are upscattered in an analog of
+the synchrotron self-Compton process. In fluctuations with a > 1, radiation is
+generated by the standard synchrotron mechanism, and the maximum photon energy
+rises linearly with a, until saturating at approximately 70 MeV.",1001.0687v1
+2010-01-21,Control of the amplification process in baseline XFEL undulator with mechanical SASE switchers,"The magnetic gap of the baseline XFEL undulators can be varied mechanically
+for wavelength tuning. In particular, the wavelength range 0.1 nm - 0.4 nm can
+be covered by operating the European XFEL with the SASE2 undulator. The length
+of the SASE2 undulator (256.2 m) is sufficient to independently generate three
+pulses of different radiation wavelengths at saturation. Normally, if a SASE
+FEL operates in saturation, the quality of the electron beam is too bad for
+generation of SASE radiation in the subsequent part of undulator which is
+resonant at a few times longer wavelength. The new method of SASE
+undulator-switching based on the rapid switching of the FEL amplification
+process proposed in this paper is an attempt to get around this obstacle. Using
+mechanical SASE shutters installed within short magnetic chicanes in the
+baseline undulator, it is possible to rapidly switch the FEL photon beam from
+one wavelength to another, providing simultaneous multi-color capability.
+Combining this method with a photon-beam distribution system can provide an
+efficient way to generate a multi-user facility.",1001.3812v1
+2011-09-08,Mach Number Dependence of Turbulent Magnetic Field Amplification: Solenoidal versus Compressive Flows,"We study the growth rate and saturation level of the turbulent dynamo in
+magnetohydrodynamical simulations of turbulence, driven with solenoidal
+(divergence-free) or compressive (curl-free) forcing. For models with Mach
+numbers ranging from 0.02 to 20, we find significantly different magnetic field
+geometries, amplification rates, and saturation levels, decreasing strongly at
+the transition from subsonic to supersonic flows, due to the development of
+shocks. Both extreme types of turbulent forcing drive the dynamo, but
+solenoidal forcing is more efficient, because it produces more vorticity.",1109.1760v1
+2012-03-14,Oxygen vacancy enhanced room temperature ferromagnetism in Al-doped MgO nanoparticles,"We have investigated the room temperature ferromagnetic order that develops
+in Al-substituted magnesium oxide, Mg(Al)O, nanoparticles with Al fractions of
+up to 5 at.%. All samples, including undoped MgO nanoparticles, exhibit room
+temperature ferromagnetism, with the saturation magnetization reaching a
+maximum of 0.023 emu/g at 2 at.% of Al. X-ray photoelectron spectroscopy
+identifies the presence of oxygen vacancies in both doped and undoped MgO
+nanoparticles, with the vacancy concentration increasing upon vacuum annealing
+of Mg(Al)O, resulting in two-fold enhancement of the saturation magnetization
+for 2 at.% Al-doped MgO. Our results suggest that the oxygen vacancies are
+largely responsible for room temperature ferromagnetism in MgO.",1203.2991v3
+2013-02-15,Equatorial trench at the magnetopause under saturation,"Magnetic data from GOES geosynchronous satellites were applied for
+statistical study of the low-latitude dayside magnetopause under a strong
+interplanetary magnetic field of southward orientation when the reconnection at
+the magnetopause was saturated. From minimum variance analysis, we determined
+the magnetopause orientation and compared it with predictions of a reference
+model. The magnetopause shape was found to be substantially distorted by a
+duskward shifting such that the nose region appeared in the postnoon sector. At
+equatorial latitudes, the shape of magnetopause was characterized by a
+prominent bluntness and by a trench formed in the postnoon sector. The origin
+of distortions was regarded in the context of the storm-time magnetospheric
+currents and the large-scale quasi-state reconnection at the dayside
+magnetopause.",1302.3735v1
+2013-04-26,A micro-structured ion-implanted magnonic crystal,"We investigate spin-wave propagation in a microstructured magnonic-crystal
+waveguide fabricated by localized ion implantation. The irradiation caused a
+periodic variation in the saturation magnetization along the waveguide. As a
+consequence, the spin-wave transmission spectrum exhibits a set of frequency
+bands, where spin-wave propagation is suppressed. A weak modification of the
+saturation magnetization by 7% is sufficient to decrease the spin-wave
+transmission in the band gaps by a factor of 10. These results evidence the
+applicability of localized ion implantation for the fabrication of efficient
+micron- and nano-sized magnonic crystals for magnon spintronic applications.",1304.7122v1
+2016-09-08,On the Origin of Non-Saturating Linear Magnetoresistivity,"The observation of non-saturating classical linear magnetoresistivity has
+been an enigmatic phenomenon in solid state physics. We present a study of a
+two-dimensional ohmic conductor, including local Hall effect and a
+self-consistent consideration of the environment. An equivalent-circuit scheme
+delivers a simple and convincing argument why the magnetoresistivity is linear
+in strong magnetic field, provided that current and biasing electric field are
+misaligned by a nonlocal mechanism. A finite-element model of a two-dimensional
+conductor is suited to display the situations that create such deviating
+currents. Besides edge effects next to electrodes, charge carrier density
+fluctuations are efficiently generating this effect. However, mobility
+fluctuations that have frequently been related to linear magnetoresistivity are
+barely relevant. Despite its rare observation, linear magnetoresitivity is
+rather the rule than the exception in a regime of low charge carrier densities,
+misaligned current pathways and strong magnetic field.",1609.02418v1
+2016-11-21,Quantum phase transitions in Heisenberg $J_1-J_2$ triangular antiferromagnet in a magnetic field,"We present the zero temperature phase diagram of a Heisenberg antiferromagnet
+on a frustrated triangular lattice with nearest neighbor ($J_1$) and next
+nearest neighbor ($J_2$) interactions, in a magnetic field. We show that the
+classical model has an accidental degeneracy for all $J_2/J_1$ and all fields,
+but the degeneracy is lifted by quantum fluctuations. We show that at large
+$S$, for $J_2/J_1 <1/8$, quantum fluctuations select the same sequence of three
+sublattice co-planar states in a field as for $J_2 =0$, and for $1/8<J_2/J_1
+<1$ they select the canted stripe state for all non-zero fields. The transition
+between the two states is first order in all fields, with the hysteresis width
+set by quantum fluctuations. We study the model with arbitrary $S$, including
+$S=1/2$, near the saturation field by exploring the fact that near saturation
+the density of bosons is small for all $S$. We show that for $S >1$, the
+transition remains first order, with a finite hysteresis width, but for $S=1/2$
+and, possibly, $S=1$, there appears a new intermediate phase, likely without a
+spontaneous long-range order.",1611.06920v2
+2017-04-11,Long range interactions in antiferromagnetic quantum spin chains,"We study the role of long range dipolar interactions on antiferromagnetic
+spin chains, from the classical $S\to \infty$ limit to the deep quantum case
+$S=1/2$, including a transverse magnetic field. To this end, we combine
+different techniques such as classical energy minima, classical Monte Carlo,
+linear spin waves, bosonization and DMRG. We find a phase transition from the
+already reported dipolar ferromagnetic region to an antiferromagnetic region
+for high enough antiferromagnetic exchange. Thermal and quantum fluctuations
+destabilize the classical order before reaching magnetic saturation in both
+phases, and also close to zero field in the antiferromagnetic phase. In the
+extreme quantum limit $S=1/2$, extensive DMRG computations show that the main
+phases remain present with transition lines to saturation significatively
+shifted to lower fields, in agreement with the bosonization analysis. The
+overall picture keeps close analogy with the phase diagram of the anisotropic
+XXZ spin chain in a transverse field.",1704.03420v3
+2017-07-06,Switching from pyroelectric to ferroelectric order in Ni doped CaBaCo4O7,"We report ferroelectric ordering in Ni substituted CaBaCo4O7. Magnetization
+showed ferrimagnetic transition at 60 K and an additional transition is found ~
+82 K, further, enhanced antiferromagnetic interactions and decrease in
+saturation magnetization are noticed with Ni substitution. The dielectric and
+pyroelectric measurements illustrate a strong coupling between spin and charge
+degrees of freedom; ferroelectric behavior is confirmed with enhanced ordering
+temperature (~82 K) and saturation polarization (250 muC/m2. Neutron
+diffraction has revealed an increase in c-lattice parameter in Ni sample and
+all the Co/Ni moments are reoriented in a- direction; evidently a non-collinear
+ferrimagnetic to collinear ferrimagnetic spin order is observed. The coupling
+between the triangular and Kagome layers weakens and leads to up-up-down-down
+AFM ordering in the Kagoma layer. This can be viewed as a 2D-collinear layer
+with unequal bond distances and most likely responsible for the switching of
+electric polarization.",1707.01712v1
+2018-07-09,Magnetic quenching of the inverse cascade in rapidly rotating convective turbulence,"We present results from an asymptotic magnetohydrodynamic model that is
+suited for studying the rapidly rotating, low viscosity regime typical of the
+electrically conducting fluid interiors of planets and stars. We show that the
+presence of sufficiently strong magnetic fields prevents the formation of
+large-scale vortices and saturates the inverse cascade at a finite
+length-scale. This saturation corresponds to an equilibrated state in which the
+energetics of the depth-averaged flows are characterized by a balance of
+convective power input and ohmic dissipation. A quantitative criteria
+delineating the transition between finite-size flows and domain-filling
+(large-scale) vortices in electrically conducting fluids is found. By making
+use of the inferred and observed properties of planetary interiors, our results
+suggest that convection-driven large-scale vortices do not form in the
+electrically conducting regions of many bodies.",1807.03268v2
+2019-02-22,Temperature-dependent Saturation of Weibel-type Instabilities in Counter-streaming Plasmas,"We present the first 2X2V continuum Vlasov-Maxwell simulations of
+interpenetrating, unmagnetized plasmas to study the competition between
+two-stream, Oblique, and filamentation modes in the weakly relativistic regime.
+We find that after nonlinear saturation of the fastest-growing two-stream and
+Oblique modes, the effective temperature anisotropy, which drives current
+filament formation via the secular Weibel instability, has a strong dependence
+on the internal temperature of the counter-streaming plasmas. The effective
+temperature anisotropy is significantly more reduced in colder than in hotter
+plasmas, leading to orders of magnitude lower magnetization for colder plasmas.
+A strong dependence of the energy conversion efficiency of Weibel-type
+instabilities on internal beam temperature has implications for determining
+their contribution to the observed magnetization of many astrophysical and
+laboratory plasmas.",1902.08672v1
+2019-05-20,Efficient quasi-kinematic large-scale dynamo as the small-scale dynamo saturates,"Large-scale magnetic fields in stars and galaxies are thought to arise by
+mean-field dynamo action due to the combined influence of both helical
+turbulence and shear. Those systems are also highly conducting and the
+turbulence therein leads to a fluctuation (or small-scale) dynamo which more
+rapidly amplifies magnetic field fluctuations on the eddy scales and smaller.
+Will this then interfere with and suppress the mean (or large-scale) field
+growth? Using direct numerical simulations of helical turbulence (with and
+without shear), we identify a novel quasi-kinematic large-scale dynamo which
+operates as the small-scale dynamo saturates. Thus both dynamos operate
+efficiently, one after the other, and lead to the generation of significant
+large-scale fields.",1905.08278v1
+2019-08-23,A Correlation in the Waiting-time Distributions of Solar Flares,"In isolated solar active regions, we find that the waiting times between
+flares correlate with flare magnitudes as determined by the GOES soft X-ray
+fluxes. A ""build-up and release"" scenario (BUR) for magnetic energy storage in
+the solar corona suggests the existence of such a relationship, relating the
+slowly varying subphotospheric energy sources to the sudden coronal energy
+releases of flares and CMEs. Substantial amounts of research effort had not
+previously found any obvious observational evidence for such a BUR process.
+This has posed a puzzle since coronal magnetic energy storage represents the
+consensus view of the basic flare mechanism. We have revisited the GOES soft
+X-ray flare statistics for any evidence of correlations, using two isolated
+active regions, and have found significant evidence for a ""saturation""
+correlation. Rather than a ""reset"" form of this relaxation, in which the time
+\textit{before} a flare correlates with its magnitude, the ""saturation""
+relationship results in the time \textit{after} the flare showing the
+correlation. The observed correlation competes with the effect of reduced GOES
+sensitivity, in which weaker events can be under-reported systematically. This
+complicates the observed correlation, and we discuss several approaches to
+remedy this.",1908.08749v2
+2019-09-10,Transport properties of Keplerian flows in extended local domains with no imposed field,"We compare transport statistics of elongated incompressible shearing boxes
+for different Reynolds and magnetic Prandtl numbers, $Re$ and $Pm$, and aspect
+ratios, $L_z/L_x$. We find that at fixed aspect ratio $L_z/L_x=4$ and $Re =
+10,000$, the turbulent stresses for $Pm \lesssim 1$ do not show considerable
+variation and follow a power law $\sim Pm^{3/2}$ for $Pm > 1$. This is
+qualitatively consistent with previous results based on net imposed flux and
+small box $L_z/L_x \sim 1$ simulations but the power law exponent is different.
+The saturated level of stresses, the ratio of Maxwell stress to the magnetic
+energy and Reynolds to Maxwell stress ratio are roughly invariant as $L_z/L_x$
+is increased. For cases where the boxes are elongated in both the azimuth and
+vertical direction, the transport coefficient $\alpha \in [0.1,1.0]$ that is
+$10-100$ times larger than the case with $L_y/L_x = 2$ and large $L_z/L_x$.
+Overall, our results suggest that the saturated state of turbulence is
+sensitive to both dissipation coefficients and aspect ratio (both $L_z/L_x$,
+$L_y/L_x$) motivating further work on this problem.",1909.04290v1
+2022-01-21,Cavity Ferromagnetic Resonance Study of Acoustic and Optic excitations in Ru/Cr/Co and Ru/Co multilayers,"Two series of [Ru10/Cox)]12 and [Ru6/Cr3/Cox)]12 x=16-60 easy-plane
+anisotropy multilayers (all thicknesses in {\AA}), prepared by sputter
+deposition, are studied by cavity FMR. The acoustic modes are excited by
+setting the RF field perpendicular to the saturating in-plane field. Their
+resonance fields are in good agreement with the values predicted for acoustic
+modes by macrospin models, using the interlayer RKKY exchange and anisotropy
+fields derived by the magnetic measurements. The resonance fields of the modes
+excited by setting the RF field parallel to the saturating field, are lower
+than those expected for optical modes. This and could attributed to the
+existence of hybridized mixed modes, according to results of micromagnetic
+simulations which also show that the mode mixing is related to the
+inhomogeneous magnetization profile along the multilayer thickness.",2201.08630v1
+2022-09-29,"Magnetic properties, electrical resistivity, and hardness of high-entropy alloys FeCoNiPd and FeCoNiPt","We report the magnetic properties, electrical resistivity, and Vickers
+microhardness of as-cast and annealed high-entropy alloys (HEAs) FeCoNiPd and
+FeCoNiPt with the face-centered cubic structure. The heat treatment at 800
+$^{\circ}$C does not largely affect the physical properties in each HEA. The
+values of the Curie temperature and the saturation moment at 50 K are 955 K and
+1.458 $\mu_\mathrm{B}$/f.u. for the annealed FeCoNiPd, and 851 K and 1.456
+$\mu_\mathrm{B}$/f.u. for the annealed FeCoNiPt, respectively. Each HEA is a
+soft ferromagnet and shows metallic resistivity. The electronic structure
+calculations of both HEAs support the ferromagnetic ground states. The
+comparisons between experimental and theoretical values are made for the Curie
+temperature, the saturation moment, and the residual resistivity. The Vickers
+microhardness of annealed FeCoNiPd and FeCoNiPt are both 188 HV. The hardness
+vs. valence electron count (VEC) per atom plot of these HEAs does not largely
+deviate from an expected universal relation forming a broad peak at
+VEC$\sim$6.8. This study would give some hints on designing a soft
+ferromagnetic HEA with high hardness.",2209.14506v1
+2023-03-06,Neutron star mass-radius constraints using the high-frequency QPOs of GRB 200415A,"Quasi-periodic oscillations (QPOs) observed in a giant flare of a strongly
+magnetized neutron star (magnetar), are carrying crucial information for
+extracting the neutron star properties. The aim of the study is to constrain
+the mass and radius of the neutron star model for GRB 200415A, by identifying
+the observed QPOs with the crustal torsional oscillations together with the
+experimental constraints on the nuclear matter properties. The frequencies of
+the crustal torsional oscillations are determined by solving the eigenvalue
+problem with the Cowling approximation, assuming a magnetic field of about
+$10^{15}$G. We find that the observed QPOs can be identified with several
+overtones of crustal oscillations, for carefully selected combinations of the
+nuclear saturation parameters. Thus, we can inversely constrain the neutron
+star mass and radius for GRB 200415A by comparing them to the values of nuclear
+saturation parameters obtained from terrestrial experiments. We impose further
+constraints on the neutron star mass and radius while the candidate neutron
+star models are consistent with the constraints obtained from other available
+astronomical and experimental observations.",2303.03150v2
+2023-03-22,Role of alkaline metal in the rare-earth triangular antiferromagnet KYbO$_2$,"We report crystal structure and magnetic behavior of the triangular
+antiferromagnet KYbO$_2$, the A-site substituted version of the quantum spin
+liquid candidate NaYbO$_2$. The replacement of Na by K introduces an
+anisotropic tensile strain with 1.6% in-plane and 12.1% out-of-plane lattice
+expansion. Compared to NaYbO$_2$, both Curie-Weiss temperature and saturation
+field are reduced by about 20% as the result of the increased Yb--O--Yb angles,
+whereas the $g$-tensor of Yb$^{3+}$ becomes isotropic with $g=3.08(3)$.
+Field-dependent magnetization shows the plateau at 1/2 of the saturated value
+and suggests the formation of the up-up-up-down field-induced order in the
+triangular AYbO$_2$ oxides (A = alkali metal), in contrast to the isostructural
+selenides that exhibit the 1/3 plateau and the up-up-down field-induced order.",2303.12448v2
+2023-05-04,Dynamics of magnetoelastic robots in water-saturated granular beds,"We investigate the dynamics of a magnetoelastic robot with a dipolar magnetic
+head and a slender elastic body as it performs undulatory strokes and burrows
+through water-saturated granular beds. The robot is actuated by an oscillating
+magnetic field and moves forward when the stroke amplitude increases above a
+critical threshold. By visualizing the medium, we show that the undulating body
+fluidizes the bed, resulting in the appearance of a dynamic burrow, which
+rapidly closes in behind the moving robot as the medium loses energy. We
+investigate the applicability of Lighthill's elongated body theory of fish
+locomotion, and estimate the contribution of thrust generated by the undulating
+body and the drag incorporating the granular volume fraction-dependent
+effective viscosity of the medium. The projected speeds are found to be
+consistent with the measured speeds over a range of frequencies and amplitudes
+above the onset of forward motion. However, systematic deviations are found to
+grow with increasing driving, pointing to a need for further sophisticated
+modelling of the medium-structure interactions.",2305.02903v2
+2024-01-24,"Hybrid Dynamical Model for Reluctance Actuators Including Saturation, Hysteresis and Eddy Currents","A novel hybrid dynamical model for single-coil, short-stroke reluctance
+actuators is presented in this paper. The model, which is partially based on
+the principles of magnetic equivalent circuits, includes the magnetic phenomena
+of hysteresis and saturation by means of the generalized Preisach model. In
+addition, the eddy currents induced in the iron core are also considered, and
+the flux fringing effect in the air is incorporated by using results from
+finite element simulations. An explicit solution of the dynamics without need
+of inverting the Preisach model is derived, and the hybrid automaton that
+results from combining the electromagnetic and motion equations is presented
+and discussed. Finally, an identification method to determine the model
+parameters is proposed and experimentally illustrated on a real actuator. The
+results are presented and the advantages of our modeling method are emphasized.",2402.00049v1
+2011-08-01,The Radio Activity-Rotation Relation of Ultracool Dwarfs,"[Abridged] We present a new radio survey of about 100 late-M and L dwarfs
+undertaken with the VLA. The sample was chosen to explore the role of rotation
+in the radio activity of ultracool dwarfs. Combining the new sample with
+results from our previous studies and from the literature, we compile the
+largest sample to date of ultracool dwarfs with radio observations and measured
+rotation velocities (167 objects). In the spectral type range M0-M6 we find a
+radio activity-rotation relation, with saturation at log(L_rad/L_bol) 10^(-7.5)
+above vsini~5 km/s, similar to the relation in H-alpha and X-rays. However, at
+spectral types >M7 the ratio of radio to bolometric luminosity increases
+regardless of rotation velocity, and the scatter in radio luminosity increases.
+In particular, while the most rapid rotators (vsini>20 km/s) exhibit
+""super-saturation"" in X-rays and H-alpha, this effect is not seen in the radio.
+We also find that ultracool dwarfs with vsini>20 km/s have a higher radio
+detection fraction by about a factor of 3 compared to objects with vsini<10
+km/s. When measured in terms of the Rossby number (Ro), the radio
+activity-rotation relation follows a single trend and with no apparent
+saturation from G to L dwarfs and down to Ro~10^-3; in X-rays and H-alpha there
+is clear saturation at Ro<0.1, with super-saturation beyond M7. A similar trend
+is observed for the radio surface flux (L_rad/R^2) as a function of Ro. The
+continued role of rotation in the overall level of radio activity and in the
+fraction of active sources, and the single trend of L_rad/L_bol and L_rad/R^2
+as a function of Ro from G to L dwarfs indicates that rotation effects are
+important in regulating the topology or strength of magnetic fields in at least
+some fully-convective dwarfs. The fact that not all rapid rotators are detected
+in the radio provides additional support to the idea of dual dynamo states.",1108.0415v1
+2008-04-08,Spherical Accretion with Anisotropic Thermal Conduction,"We study the effects of anisotropic thermal conduction on magnetized
+spherical accretion flows using global axisymmetric MHD simulations. In low
+collisionality plasmas, the Bondi spherical accretion solution is unstable to
+the magnetothermal instability (MTI). The MTI grows rapidly at large radii
+where the inflow is subsonic. For a weak initial field, the MTI saturates by
+creating a primarily radial magnetic field, i.e., by aligning the field lines
+with the background temperature gradient. The saturation is quasilinear in the
+sense that the magnetic field is amplified by a factor of $\sim 10-30$
+independent of the initial field strength (for weak fields). In the saturated
+state, the conductive heat flux is much larger than the convective heat flux,
+and is comparable to the field-free (Spitzer) value (since the field lines are
+largely radial). The MTI by itself does not appreciably change the accretion
+rate $\dot M$ relative to the Bondi rate $\dot M_B$. However, the radial field
+lines created by the MTI are amplified by flux freezing as the plasma flows in
+to small radii. Oppositely directed field lines are brought together by the
+converging inflow, leading to significant resistive heating. When the magnetic
+energy density is comparable to the gravitational potential energy density, the
+plasma is heated to roughly the virial temperature; the mean inflow is highly
+subsonic; most of the energy released by accretion is transported to large
+radii by thermal conduction; and the accretion rate $\dot M \ll \dot M_B$. The
+predominantly radial magnetic field created by the MTI at large radii in
+spherical accretion flows may account for the stable Faraday rotation measure
+towards Sgr A* in the Galactic Center.",0804.1353v2
+2008-08-27,Epitaxial Zn(x)Fe(3-x)O(4) Thin Films: A Spintronic Material with Tunable Electrical and Magnetic Properties,"The ferrimagnetic spinel oxide Zn(x)Fe(3-x)O(4) combines high Curie
+temperature and spin polarization with tunable electrical and magnetic
+properties, making it a promising functional material for spintronic devices.
+We have grown epitaxial thin films with 0<=x<=0.9 on MgO(001) substrates with
+excellent structural properties both in pure Ar atmosphere and an Ar/O2 mixture
+by laser molecular beam epitaxy. We find that the electrical conductivity and
+the saturation magnetization can be tuned over a wide range during growth. Our
+extensive characterization of the films provides a clear picture of the
+underlying physics of this spinel ferrimagnet with antiparallel Fe moments on
+the A and B sublattice: (i) Zn substitution removes both Fe3+ moments from the
+A sublattice and itinerant charge carriers from the B sublattice, (ii) growth
+in finite oxygen partial pressure generates Fe vacancies on the B sublattice
+also removing itinerant charge carriers, and (iii) application of both Zn
+substitution and excess oxygen results in a compensation effect as Zn
+substitution partially removes the Fe vacancies. A decrease (increase) of
+charge carrier density results in a weakening (strengthening) of double
+exchange and thereby a decrease (increase) of conductivity and the saturation
+magnetization. This scenario is confirmed by the observation that the
+saturation magnetization scales with the longitudinal conductivity. The
+combination of tailored films with semiconductor materials such as ZnO in
+multi-functional heterostructures seems to be particularly appealing.",0808.3642v3
+2008-10-26,Non-linear Study of Bell's Cosmic Ray Current-driven Instability,"The cosmic ray current-driven (CRCD) instability, predicted by Bell (2004),
+consists of non-resonant, growing plasma waves driven by the electric current
+of cosmic rays (CRs) that stream along the magnetic field ahead of both
+relativistic and non-relativistic shocks. Combining an analytic, kinetic model
+with one-, two-, and three-dimensional particle-in-cell simulations, we confirm
+the existence of this instability in the kinetic regime and determine its
+saturation mechanisms. In the linear regime, we show that, if the background
+plasma is well magnetized, the CRCD waves grow exponentially at the rates and
+wavelengths predicted by the analytic dispersion relation. The magnetization
+condition implies that the growth rate of the instability is much smaller than
+the ion cyclotron frequency. As the instability becomes non-linear, significant
+turbulence forms in the plasma. This turbulence reduces the growth rate of the
+field and damps the shortest wavelength modes, making the dominant wavelength,
+\lambda_d, grow proportional to the square of the field. At constant CR
+current, we find that plasma acceleration along the motion of CRs saturates the
+instability at the magnetic field level such that v_A ~ v_{d,cr}, where v_A is
+the Alfven velocity in the amplified field, and v_{d,cr} is the drift velocity
+of CRs. The instability can also saturate earlier if CRs get strongly deflected
+by the amplified field, which happens when their Larmor radii get close to
+\lambda_d. We apply these results to the case of CRs in the upstream medium of
+supernova remnants. Considering only the most energetic CRs that escape from
+the shock, we obtain that the field amplification factor of ~10 can be reached.
+This confirms the CRCD instability as a potentially important component of
+magnetic amplification process in astrophysical shocks.",0810.4565v1
+2011-07-23,Dephasing and Hyperfine Interaction in Carbon Nanotubes Double Quantum Dots: The Clean Limit,"We consider theoretically ${}^{13}$C-hyperfine interaction induced dephasing
+in carbon nanotubes double quantum dots with curvature induced spin-orbit
+coupling. For two electrons initially occupying a single dot, we calculate the
+average return probability after separation into the two dots, which have
+random nuclear-spin configurations. We focus on the long time saturation value
+of the return probability, $P_\infty$. Because of the valley degree of freedom,
+the analysis is more complex than in, for example, GaAs quantum dots, which
+have two distinct $P_\infty$ values depending on the magnetic field. Here the
+prepared state and the measured state is non-unique because two electrons in
+the same dot are allowed in six different states. Moreover, for one electron in
+each dot sixteen states exist and therefore are available for being mixed by
+the hyperfine field. The return probability experiment is found to be strongly
+dependent on the prepared state, on the external magnetic field---both Zeeman
+and orbital effects - and on the spin-orbit splitting. The lowest saturation
+value, being $P_\infty$=1/3, occurs at zero magnetic field for nanotubes with
+spin-orbit coupling and the initial state being the groundstate, this situation
+is equivalent to double dots without the valley degree of freedom. In total, we
+report nine dynamically different situations that give $P_\infty$=1/3, 3/8,
+2/5, 1/2 and for valley anti-symmetric prepared states in an axial magnetic
+field, $P_\infty$=1. When the groundstate is prepared the ratio between the
+spin-orbit splitting and the Zeeman energy due to a perpendicular magnetic
+field can tune the effective hyperfine field continuously from being three
+dimensional to two dimensional giving saturation values from $P_\infty$=1/3 to
+3/8.",1107.4710v1
+2012-10-11,Fluctuation dynamos and their Faraday rotation signatures,"Turbulence is ubiquitous in many astrophysical systems like galaxies, galaxy
+clusters and possibly even the IGM filaments. We study fluctuation dynamo
+action in turbulent systems focusing on one observational signature; the
+Faraday rotation measure (RM) from background radio sources seen through the
+magnetic field generated by such a dynamo. We simulate the fluctuation dynamo
+(FD) in periodic boxes up to resolutions of 512^3, with varying fluid and
+magnetic Reynolds numbers, and measure the resulting random RMs. We show that,
+even though the magnetic field generated is intermittent, it still allows for
+contributions to the RM to be significant. When the dynamo saturates, it is of
+order 40%-50% of the value expected in a model where fields of strength B_rms
+uniformly fill cells of the largest turbulent eddy but are randomly oriented
+from one cell to another. This level of RM dispersion obtains across different
+values of magnetic Reynolds number and Prandtl number explored. We also use the
+random RMs to probe the structure of the generated fields to distinguish the
+contribution from intense and diffuse field regions. We find that the strong
+field regions (say with B > 2B_rms) contribute only of order 15%-20% to the RM.
+Thus rare structures do not dominate the RM; rather the general 'sea' of volume
+filling fluctuating fields are the dominant contributors. We also show that the
+magnetic integral scale, L_{int}, which is directly related to the RM
+dispersion, increases in all the runs, as Lorentz forces become important to
+saturate the dynamo. It appears that due to the ordering effect of the Lorentz
+forces, L_{int} of the saturated field tends to a modest fraction, 1/2-1/3 of
+the integral scale of the velocity field, for all our runs. These results are
+then applied to discuss the RM signatures of FD generated fields in young
+galaxies, galaxy clusters and intergalactic filaments.",1210.3243v2
+2020-02-06,A Non-Linear Magnetic Field Calibration Method for Filter-Based Magnetographs by Multilayer Perceptron,"For filter-based magnetographs, the linear calibration method under the
+weak-field assumption is usually adopted; this leads to magnetic saturation
+effect in the regions with strong magnetic field. This article explores a new
+method to overcome the above disadvantage using a multilayer perceptron
+network, which we call MagMLP, based on a back-propagation algorithm with one
+input layer, five hidden layers, and one output layer. We use the data from the
+\textit{Spectropolarimeter} (SP) on board \textit{Hinode} to simulate
+single-wavelength observations for the model training, and take into account
+the influence of the Doppler velocity field and the filling factor. The
+training results show that the linear fitting coefficient (LFC) of the
+transverse field reaches above 0.91, and that of the longitudinal field is
+above 0.98. The generalization of the models is good because the corresponding
+LFCs are above 0.9 for the test subsets. Compared with the linear calibration
+method, the MagMLP is much more effective on dealing with the magnetic
+saturation effect. Analyzing an active region, the results of the linear
+calibration present an evident magnetic saturation effect in the umbra regions;
+the corresponding systematic error reaches values greater than 1000 G in most
+areas, or even exceeds 2000 G at some pixels. However, the results of MagMLP at
+these locations are very close to the inversion results, and the systematic
+errors are basically within 300 G. In addition, we find that there are many
+""bright spots"" and ""dark spots"" on the inclination angle images from the
+inversion results of \textit{Hinode}/SP with values of 180 and 0 degrees,
+respectively, where the inversion is not reliable and does not produce a good
+result; the MagMLP handles these points well.",2002.02249v1
+2014-01-30,Mixing in Magnetized Turbulent Media,"Turbulent motions are essential to the mixing of entrained fluids and are
+also capable of amplifying weak initial magnetic fields by small-scale dynamo
+action. Here we perform a systematic study of turbulent mixing in magnetized
+media, using three-dimensional magnetohydrodynamic simulations that include a
+scalar concentration field. We focus on how mixing depends on the magnetic
+Prandtl number, Pm, from 1 to 4 and the Mach number, M}, from 0.3 to 2.4. For
+all subsonic flows, we find that the velocity power spectrum has a k^-5/3 slope
+in the early, kinematic phase, but steepens due to magnetic back reactions as
+the field saturates. The scalar power spectrum, on the other hand, flattens
+compared to k^-5/3 at late times, consistent with the Obukohov-Corrsin picture
+of mixing as a cascade process. At higher Mach numbers, the velocity power
+spectrum also steepens due to the presence of shocks, and the scalar power
+spectrum again flattens accordingly. Scalar structures are more intermittent
+than velocity structures in subsonic turbulence while for supersonic
+turbulence, velocity structures appear more intermittent than the scalars only
+in the kinematic phase. Independent of the Mach number of the flow, scalar
+structures are arranged in sheets in both the kinematic and saturated phases of
+the magnetic field evolution. For subsonic turbulence, scalar dissipation is
+hindered in the strong magnetic field regions, probably due to Lorentz forces
+suppressing the buildup of scalar gradients, while for supersonic turbulence,
+scalar dissipation increases monotonically with increasing magnetic field
+strength. At all Mach numbers, mixing is significantly slowed by the presence
+of dynamically-important small-scale magnetic fields, implying that mixing in
+the interstellar medium and in galaxy clusters is less efficient than modeled
+in hydrodynamic simulations.",1401.8001v2
+2015-12-25,Collective magnetic response of inhomogeneous nanoisland FeNi films around the percolation transition,"By using superconducting quantum interference device (SQUID) magnetometry we
+investigated anisotropic high-field (H < 7 T) low-temperature (10 K)
+magnetization response of inhomogeneous nanoisland FeNi films grown by rf
+sputtering deposition on Sitall (TiO2) glass substrates. In the grown FeNi
+films, the FeNi layer nominal thickness varied from 0.6 to 2.5 nm, across the
+percolation transition at the d_c=1.8 nm. We discovered that, beyond
+conventional spin-magnetism of Fe21Ni79 permalloy, the extracted out-of-plane
+magnetization response of the nanoisland FeNi films is not saturated in the
+range of investigated magnetic fields and exhibits paramagnetic-like behavior.
+We found that the anomalous out-of-plane magnetization response exhibits an
+escalating slope with increase in the nominal film thickness from 0.6 to 1.1
+nm, however, it decreases with further increase in the film thickness, and then
+practically vanishes on approaching the FeNi film percolation threshold. At the
+same time, the in-plane response demonstrates saturation behavior above 1.5-2
+T, competing with anomalously large diamagnetic-like response, which becomes
+pronounced at high magnetic fields. It is possible that the supported-metal
+interaction leads to the creation of a thin charge-transfer (CT) layer and a
+Schottky barrier at the FeNi film/Sitall (TiO2) interface. Then, in the system
+with nanoscale circular domains, the observed anomalous paramagnetic-like
+magnetization response can be associated with a large orbital moment of the
+localized electrons. The observed magnetization response is determined by the
+interplay between the paramagnetic- and diamagnetic-like contributions.",1512.07993v3
+2017-07-21,Magnetism out of disorder in a J=0 compound Ba2YIrO6,"We systematically investigate the magnetic properties and local structure of
+Ba2YIrO6 to demonstrate that Y and Ir lattice defects in the form of antiphase
+boundary or clusters of antisite disorder affect the magnetism observed in this
+$d^4$ compound. We compare the magnetic properties and atomic imaging of (1) a
+slow cooled crystal, (2) a crystal quenched from 900\degree C after growth, and
+(3) a crystal grown using a faster cooling rate than the slow cooled one.
+Atomic imaging by scanning transmission electron microscopy (STEM) shows that
+quenching from 900oC introduces antiphase boundary to the crystals, and a
+faster cooling rate during crystal growth leads to clusters of Y and Ir
+antisite disorder. STEM study suggests the antiphase boundary region is Ir-rich
+with a composition of Ba2YIrO6. The magnetic measurements show that Ba2YIrO6
+crystals with clusters of antisite defects have a larger effective moment and a
+larger saturation moment than the slow-cooled crystals. Quenched crystals with
+Ir-rich antiphase boundary shows a slightly suppressed saturation moment than
+the slow cooled crystals, and this seems to suggest that antiphase boundary is
+detrimental to the moment formation. Our DFT calculations suggest magnetic
+condensation is unlikely as the energy to be gained from superexchange is small
+compared to the spin-orbit gap. However, once Y is replaced by Ir in the
+antisite disordered region, the picture of local non-magnetic singlets breaks
+down and magnetism can be induced. This is because of (a) enhanced interactions
+due to increased overlap of orbitals between sites, and, (b) increased number
+of orbitals mediating the interactions. Our work highlights the importance of
+lattice defects in understanding the experimentally observed magnetism in
+Ba2YIrO6 and other J=0 systems.",1707.06980v1
+2022-04-01,"Magnetism, rotation, and nonthermal emission in cool stars -- Average magnetic field measurements in 292 M dwarfs","Stellar dynamos generate magnetic fields that are of fundamental importance
+to the variability and evolution of Sun-like and low-mass stars, and for the
+development of their planetary systems. We report measurements of
+surface-average magnetic fields in 292 M dwarfs from a comparison with
+radiative transfer calculations; for 260 of them, this is the first measurement
+of this kind. Our data were obtained from more than 15,000 high-resolution
+spectra taken during the CARMENES project. They reveal a relation between
+average field strength, <B>, and Rossby number, $Ro$, resembling the
+well-studied rotation-activity relation. Among the slowly rotating stars, we
+find that magnetic flux, $\Phi_\textrm{B}$, is proportional to rotation period,
+$P$, and among the rapidly rotating stars that average surface fields do not
+grow significantly beyond the level set by the available kinetic energy.
+Furthermore, we find close relations between nonthermal coronal X-ray emission,
+chromospheric H$\alpha$ and Ca H&K emission, and magnetic flux. Taken together,
+these relations demonstrate empirically that the rotation-activity relation can
+be traced back to a dependence of the magnetic dynamo on rotation. We advocate
+the picture that the magnetic dynamo generates magnetic flux on the stellar
+surface proportional to rotation rate with a saturation limit set by the
+available kinetic energy, and we provide relations for average field strengths
+and nonthermal emission that are independent of the choice of the convective
+turnover time. We also find that Ca H&K emission saturates at average field
+strengths of $\langle B \rangle \approx 800$ G while H$\alpha$ and X-ray
+emission grow further with stronger fields in the more rapidly rotating stars.
+This is in conflict with the coronal stripping scenario predicting that in the
+most rapidly rotating stars coronal plasma would be cooled to chromospheric
+temperatures.",2204.00342v1
+2023-07-03,Interplay between local moment and itinerant magnetism in the layered metallic antiferromagnet TaFe$_{1.14}$Te$_3$,"Two-dimensional (2D) antiferromagnets have garnered considerable interest for
+the next generation of functional spintronics. However, many available bulk
+materials from which 2D antiferromagnets are isolated are limited by their
+sensitivity to air, low ordering temperatures, and insulating transport
+properties. TaFe$_{1+y}$Te$_3$ offers unique opportunities to address these
+challenges with increased air stability, metallic transport properties, and
+robust antiferromagnetic order. Here, we synthesize TaFe$_{1+y}$Te$_3$ ($y$ =
+0.14), identify its structural, magnetic, and electronic properties, and
+elucidate the relationships between them. Axial-dependent high-field
+magnetization measurements on TaFe$_{1.14}$Te$_3$ reveal saturation magnetic
+fields ranging between 27-30 T with a saturation magnetic moment of 2.05-2.12
+$\mu_B$. Magnetotransport measurements confirm TaFe$_{1.14}$Te$_3$ is metallic
+with strong coupling between magnetic order and electronic transport.
+Angle-resolved photoemission spectroscopy measurements across the magnetic
+transition uncover a complex interplay between itinerant electrons and local
+magnetic moments that drives the magnetic transition. We further demonstrate
+the ability to isolate few-layer sheets of TaFe$_{1.14}$Te$_3$ through
+mechanical exfoliation, establishing TaFe$_{1.14}$Te$_3$ as a potential
+platform for 2D spintronics based on metallic layered antiferromagnets.",2307.01397v1
+2000-05-08,Particle Heating by Nonlinear Alfvenic Turbulence in ADAFs,"Particle heating in advection-dominated accretion flows (ADAFs) by nonlinear
+MHD (Alfvenic) turbulence is investigated. Such turbulence with
+highly-fluctuating magnetic fields, $\tilde B\sim B_0$, is believed to be
+naturally produced by the magnetic shearing instability near the nonlinear
+saturation. It is shown that the energy is dissipated in the parallel cascade,
+which occurs due to nonlinear compressibility of high-amplitude turbulence, and
+predominantly heats protons, but not electrons. The conservative limit on the
+electron--to--proton heating fraction is $\delta\lesssim{\rm
+few}\times10^{-2}$.",0005119v1
+2000-12-04,On the pre-RLO spin-orbit couplings in LMXBs,"We investigate the effect of orbital decay caused by nuclear expansion of a
+(sub)giant star in synchronous binary system. We compare this effect with the
+presence of a magnetic stellar wind and show that the additional transfer of
+orbital angular momentum into spin angular momentum is relatively important --
+especially since it has been shown that the effect of magnetic braking
+saturates at short orbital periods.",0012077v1
+2006-07-14,Intrinsic properties of the magnetically collimated water maser jet of W43A,"Water maser polarization observations in the precessing jet of W43A have
+revealed that it is magnetically collimated. Here we present a detailed
+description of the physical properties of the water maser environment in the
+jet. We discuss the maser saturation level and beaming angle as well as the
+intrinsic temperatures and densities. Additionally, we show that the
+polarization angle of the strongest red-shifted maser feature undergoes a fast
+rotation of 90 degrees across the maser. Along with the variation of linear
+polarization fraction, this strongly supports the current theoretical
+description of maser linear polarization.",0607337v1
+1993-03-25,Critical Exponents of the Three Dimensional Random Field Ising Model,"The phase transition of the three--dimensional random field Ising model with
+a discrete ($\pm h$) field distribution is investigated by extensive Monte
+Carlo simulations. Values of the critical exponents for the correlation length,
+specific heat, susceptibility, disconnected susceptibility and magnetization
+are determined simultaneously via finite size scaling. While the exponents for
+the magnetization and disconnected susceptibility are consistent with a first
+order transition, the specific heat appears to saturate indicating no latent
+heat. Sample to sample fluctuations of the susceptibilty are consistent with
+the droplet picture for the transition.",9303045v1
+1995-11-07,Influence of frustration on a d=3 diluted antiferromagnet: $Fe_{x}Zn_{1-x}F_{2}$,"The influence of a frustrated bond on the magnetic properties of a d=3
+uniaxial (Ising) b.c.c. diluted antiferromagnet, with emphasis in the compound
+$Fe_{x}Zn_{1-x}F_{2}$, is investigated by a local mean-field numerical
+simulation. In particular we find that the initial drop of the saturation
+staggered magnetization ($M_{S}$) with concentration follows a percolation-like
+phenomenon characterized by an exponent $\beta_{p}$. For the frustrated
+samples, however, this regime is followed by a second one identified by a
+``long tail"" effect such that $M_{S}$ is zero only at the percolation
+threshold. Our numerical data also confirms a spin-glass phase near this
+threshold.",9511036v1
+1997-12-08,A Theory of Magnets with Competing Double Exchange and Superexchange Interactions,"We study the competition between ferromagnetic double exchange (DE) and
+nearest-neighbour antiferromagnetic exchange in CMR materials. Towards this
+end, a single site mean field theory is proposed which emphasizes the
+hopping-mediated nature of the DE contribution. We find that the competition
+between these two exchange interactions leads to ferro- or antiferromagnetic
+order with incomplete saturation of the (sub)lattice magnetization. This
+conclusion is in contrast to previous results in the literature which find a
+canted spin arrangement under similar circumstances. We attribute this
+difference to the highly anisotropic exchange interactions used elsewhere. The
+associated experimental implications are discussed.",9712094v1
+1997-12-25,Interacting Boson Theory of the Magnetization Process of the Spin-1/2 Ferromagnetic-Antiferromagnetic Alternating Heisenberg Chain,"The low temperature magnetization process of the
+ferromagnetic-antiferromagnetic Heisenberg chain is studied using the
+interacting boson approximation. In the low field regime and near the
+saturation field, the spin wave excitations are approximated by the $\delta$
+function boson gas for which the Bethe ansatz solution is available. The finite
+temperature properties are calculated by solving the integral equation
+numerically. The comparison is made with Monte Carlo calculation and the limit
+of the applicability of the present approximation is discussed.",9712289v1
+1999-11-27,Coherent vs incoherent pairing in 2D systems near magnetic instability,"We study the superconductivity in 2D fermionic systems near antiferromagnetic
+instability, assuming that the pairing is mediated by spin fluctuations. This
+pairing involves fully incoherent fermions and diffusive spin excitations. We
+show that the competition between fermionic incoherence and strong pairing
+interaction yields the pairing instability temperature $T_{ins}$ which
+increases and saturates as the magnetic correlation length $\xi \to \infty$. We
+argue that in this quantum-critical regime the pairing problem is qualitatively
+different from the BCS one.",9911445v2
+2000-08-23,Field-Induced Gaps in the Frustrated Spin Ladder,"We study the magnetization process of the $S=1/2$ antiferromagnetic spin
+ladder in the presence of the second and the third-neighbor couplings which
+lead to frustration with the typical nearest-neighbor coupling. We use
+degenerate perturbation theory and level spectroscopy analysis of the numerical
+diagonalization data of the Hamiltonian for finite systems. We find two kinds
+of plateaux at half the saturation moment in the magnetization curve. One is
+mainly due to the second-neighbor couplings and the other to the third-neighbor
+couplings. The mechanisms of these two plateaux are quite different with each
+other.",0008328v1
+2001-01-12,Spin Polarization of Two-Dimensional Electrons Determined from Shubnikov-de Haas Oscillations as a Function of Angle,"Recent experiments in the two dimensional electron systems in silicon MOSFETs
+have shown that the in-plane magnetic field $H_{sat}$ required to saturate the
+conductivity to its high-field value and the magnetic field $H_s$ needed to
+completely align the spins of the electrons are comparable. By small-angle
+Shubnikov-de Haas oscillation measurements that allow separate determinations
+of the spin-up and spin-down subband populations, we show that $H_{sat}=H_s$ to
+an accuracy of 5% for electron densities $n_s > 3 \times 10^{11}$ cm$^{-2}$.",0101196v2
+2001-02-21,Magnetization plateaus of SrCu_2(BO_3)_2 from a Chern-Simons theory,"The antiferromagnetic Heisenberg model on the frustrated Shastry-Sutherland
+lattice is studied by a mapping onto spinless fermions carrying one quantum of
+statistical flux. Using a mean-field approximation these fermions populate the
+bands of a generalized Hofstadter problem. Their filling leads to the
+magnetization curve. For SrCu_2(BO_3)_2 we reproduce plateaus at 1/3 and 1/4 of
+the saturation moment and predict a new one at 1/2. Gaussian fluctuations are
+shown to be massive at these plateau values.",0102377v1
+2001-07-27,"Noncollinear Ferromagnetism in (III,Mn)V Semiconductors","We investigate the stability of the collinear ferromagnetic state in kinetic
+exchange models for (III,Mn)V semiconductors with randomly distributed Mn ions
+>. Our results suggest that {\em noncollinear ferromagnetism} is commom to
+these semiconductor systems. The instability of the collinear state is due to
+long-ranged fluctuations invloving a large fraction of the localized magnetic
+moments. We address conditions that favor the occurrence of noncollinear
+groundstates and discuss unusual behavior that we predict for the temperature
+and field dependence of its saturation magnetization.",0107573v2
+2001-10-30,Localization corrections and small-q phonon-mediated unconventional superconductivity in the cuprates,"Taking into account the first localization corrections in the
+electron-impurity self-energy we study the effect of non-magnetic impurities on
+unconventional superconductivity (SC) mediated by small-q electron-phonon
+scattering. We show that when van Hove singularities are close to the Fermi
+level making the electronic system anisotropic as in the high-$T_c$ oxides,
+both the d-wave and s-wave states are sensitive to non-magnetic impurities and
+beyond a critical impurity concentration SC disappears in {\it both gap
+symmetry channels}. Impurity doping may induce a first order transition from
+d-wave to s-wave SC, but no saturation of the impuruty effect is reported due
+to the intrinsically anisotropic character of the localization corrections in
+this context.",0110637v1
+2001-11-12,Itinerant-electron Ferromagnetism in W(Nb)O3-d,"The crystal structure and the magnetic properties of the W1-xNbxO3-d,
+(x<0.03) system have been investigated. In contrast to the orthorhombic
+diamagnetic WO3, the material with x=0.01 is paramagnetic down to 5 K.
+Introducing of 2.5 at. % of Nb into WO3 leads to a tetragonal structure and to
+a weak itinerant ferromagnetic ordering below TC= 225 K. The saturation
+magnetic moment at 5 K is 1.07*10-3 mB, whereas the paramagnetic effective
+moment is 0.06 mB per mole. This high ratio indicates itinerant ferromagnetism
+in W0.975Nb0.025O3-d.",0111210v1
+2001-12-11,Rayleigh loops in the random-field Ising model on the Bethe lattice,"We analyze the demagnetization properties of the random-field Ising model on
+the Bethe lattice focusing on the beahvior near the disorder induced phase
+transition. We derive an exact recursion relation for the magnetization and
+integrate it numerically. Our analysis shows that demagnetization is possible
+only in the continous high disorder phase, where at low field the loops are
+described by the Rayleigh law. In the low disorder phase, the saturation loop
+displays a discontinuity which is reflected by a non vanishing magnetization
+m_\infty after a series of nested loops. In this case, at low fields the loops
+are not symmetric and the Rayleigh law does not hold.",0112190v1
+2003-06-13,Scaling of the magnetic response in doped antiferromagnets,"A theory of the anomalous $\omega/T$ scaling of the dynamic magnetic response
+in cuprates at low doping is presented. It is based on the memory function
+representation of the dynamical spin suceptibility in a doped antiferromagnet
+where the damping of the collective mode is constant and large, whereas the
+equal-time spin correlations saturate at low $T$. Exact diagonalization results
+within the t-J model are shown to support assumptions. Consequences, both for
+the scaling function and the normalization amplitude, are well in agreement
+with neutron scattering results.",0306366v2
+2003-11-14,Dynamic roughening and fluctuations of dipolar chains,"Nonmagnetic particles in a carrier ferrofluid acquire an effective dipolar
+moment when placed in an external magnetic field. This fact leads them to form
+chains that will roughen due to Brownian motion when the magnetic field is
+decreased. We study this process through experiments, theory and simulations,
+three methods that agree on the scaling behavior over 5 orders of magnitude.
+The RMS width goes initially as $t^{1/2}$, then as $t^{1/4}$ before it
+saturates. We show how these results complement existing results on polymer
+chains, and how the chain dynamics may be described by a recent non-Markovian
+formulation of anomalous diffusion.",0311340v1
+2004-02-20,Low-frequency incommensurate magnetic response in strongly correlated systems,"It is shown that in the t-J model of Cu-O planes at low frequencies the
+dynamic spin structure factor is peaked at incommensurate wave vectors
+(1/2+-delta,1/2)$, (1/2,1/2+-delta). The incommensurability is connected with
+the momentum dependencies of the magnon frequency and damping near the
+antiferromagnetic wave vector. The behavior of the incommensurate peaks is
+similar to that observed in La_{2-x}(Ba,Sr)_xCuO_{4+y} and YBa_2Cu_3O_{7-y}:
+for hole concentrations 0.02<x<=0.12 we find that delta is nearly proportional
+to x, while for x>0.12 it tends to saturation. The incommensurability
+disappears with increasing temperature. Generally the incommensurate magnetic
+response is not accompanied by an inhomogeneity of the carrier density.",0402512v1
+2004-05-29,Optical Spectroscopy of the Hole Spin in GaMnAs Acceptors,"The spin state of holes bound to Mn acceptors in GaMnAs is investigated by
+optical spectroscopy. Concentrations of Mn from 10^17 to 10^19 cm^-3 were
+studied as a function of magnetic field and temperature. The photoluminescence
+from recombination of electrons with holes bound in the Mn-acceptor complex
+(MAC) displays multiple spectral peaks. The circular polarization rho of these
+peaks increases with increasing magnetic field and saturates at rho ~= 1/3.
+This value of polarization is expected from modeling the addition of spin
+angular momentum and interband optical transition matrix elements.",0405692v1
+2004-06-08,Properties of magnetite nanoparticles synthesized through a novel chemical route,"We have developed a simple precipitation route to synthesize magnetite
+(Fe3O4) nano-particles with controlled size without any requirement of
+calcination step at high temperatures. The study of these nano-particles
+indicates an enhancement in saturation magnetization with reduction in size
+down to ~10 nm beyond which the magnetization reduces. The latter is attributed
+to surface effects becoming predominant as surface to core volume ratio
+increases. From the view -point of applications, 10 nm size of magnetite
+particles seems to be the optimum.",0406184v1
+2004-07-27,Composition dependent magnetic properties of iron oxide - polyaniline nanoclusters,"Gamma - Iron Oxide prepared by sol -gel process was used to produce
+nanocomposites with polyaniline of varying aniline concentrations. TEM shows
+the presence of chain like structure for lower polyaniline concentration. The
+room temperature hysteresis curves show finite coercivity of 160 Oe for all the
+composites while the saturation magnetization was found to decrease with
+increasing polymer content. ZFC - FC magnetisation measurements indicate high
+blocking temperatures. It is believed that this indicates a strongly
+interacting system, which is also shown by our TEM results. Monte Carlo
+simulations performed on a random anisotropy model with dipolar and exchange
+inteactions match well with experimental results.",0407693v1
+2005-03-16,Nonuniqueness in spin-density-functional theory on lattices,"In electronic many-particle systems, the mapping between densities and spin
+magnetizations, {n(r), m(r)}, and potentials and magnetic fields, {v(r), B(r)},
+is known to be nonunique, which has fundamental and practical implications for
+spin-density-functional theory (SDFT). This paper studies the nonuniqueness
+(NU) in SDFT on arbitrary lattices. Two new, non-trivial cases are discovered,
+here called local saturation and global noncollinear NU, and their properties
+are discussed and illustrated. In the continuum limit, only some well-known
+special cases of NU survive.",0503384v1
+2005-09-05,CeMnNi4: A soft ferromagnet with a high degree of transport spin polarization,"In this letter we introduce a new soft ferromagnetic compound, i.e. CeMnNi4,
+which exhibits a large moment (~4.95mu_B/Mn) and high degree of spin
+polarization. The system has a ferromagnetic transition temperature of 148K.
+Isothermal magnetization measurements at 5K reveal that the material is a soft
+ferromagnet with a magnetization saturating at about 500Oe and a coercive field
+of < 5 Oe. We determine the transport spin polarization of this material from
+Point Contact Andreev Reflection measurements to be 66% thereby making this
+material potentially important for spintronic applications.",0509101v2
+2005-12-15,"Control of Coercivities in (Ga,Mn)As Thin Films by Small Concentrations of MnAs Nanoclusters","We demonstrate that low concentrations of a secondary magnetic phase in
+(Ga,Mn)As thin films can enhance the coercivity by factors up to ~100 without
+significantly degrading the Curie temperature or saturation magnetisation.
+Magnetic measurements indicate that the secondary phase consists of MnAs
+nanoclusters, of average size ~7nm. This approach to controlling the coercivity
+while maintaining high Curie temperature, may be important for realizing
+ferromagnetic semiconductor based devices.",0512353v1
+2006-03-03,Asymmetric Reversal in Inhomogeneous Magnetic Heterostructures,"Asymmetric magnetization reversal is an unusual phenomenon in antiferromagnet
+/ ferromagnet (AF/FM) exchange biased bilayers. We investigated this phenomenon
+in a simple model system experimentally and by simulation assuming
+inhomogeneously distributed interfacial AF moments. The results suggest that
+the observed asymmetry originates from the intrinsic broken symmetry of the
+system, which results in local incomplete domain walls parallel to the
+interface in reversal to negative saturation of the FM. Magneto-optic Kerr
+effect unambiguously confirms such an asymmetric reversal and a depth-dependent
+FM domain wall in accord with the magnetometry and simulations.",0603060v1
+2006-09-15,Two-dimensional frustrated spin systems in high magnetic fields,"We discuss our numerical results on the properties of the S = 1/2 frustrated
+J1-J2 Heisenberg model on a square lattice as a function of temperature and
+frustration angle phi = atan(J2/J1) in an applied magnetic field. We cover the
+full phase diagram of the model in the range -pi <= phi <= pi. The discussion
+includes the parameter dependence of the saturation field itself, and addresses
+the instabilities associated with it. We also discuss the magnetocaloric effect
+of the model and show how it can be used to uniquely determine the effective
+interaction constants of the compounds which were investigated experimentally.",0609381v1
+1993-04-13,Critical Exponents of the Three Dimensional Random Field Ising Model,"The phase transition of the three--dimensional random field Ising model with
+a discrete ($\pm h$) field distribution is investigated by extensive Monte
+Carlo simulations. Values of the critical exponents for the correlation length,
+specific heat, susceptibility, disconnected susceptibility and magnetization
+are determined simultaneously via finite size scaling. While the exponents for
+the magnetization and disconnected susceptibility are consistent with a first
+order transition, the specific heat appears to saturate indicating no latent
+heat. Sample to sample fluctuations of the susceptibilty are consistent with
+the droplet picture for the transition.",9304007v1
+2000-10-09,Origin of the Nucleon Electromagnetic Form Factors Dipole Formula,"Starting with the VMD parametrization of the electric and magnetic nucleon
+form factors, which are saturated just by the ground state vector-mesons rho,
+omega and phi, then aplying the strict OZI rule and the asymptotic behaviour of
+form factors as predicted by quark model of hadrons, the famous one parameter
+dipole formula is derived. By its comparison with space-like data up to t = -5
+GeV^2 the most optimal value of the parameter under consideration is
+determined. Finaly, charge and magnetization distributions in proton and
+neutron are predicted.",0010084v1
+1995-03-20,The Bogomol'nyi Bound of Lee-Weinberg Magnetic Monopoles,"The Lee-Weinberg $U(1)$ magnetic monopoles, which have been reinterpreted as
+topological solitons of a certain non-Abelian gauged Higgs model recently, are
+considered for some specific choice of Higgs couplings. The model under
+consideration is shown to admit a Bogomol'nyi-type bound which is saturated by
+the configurations satisfying the generalized BPS equations. We consider the
+spherically symmetric monopole solutions in some detail.",9503123v1
+1995-12-29,Solitonic Black Holes in Gauged N=2 Supergravity,"A sequence of zero-temperature black-hole spacetimes with angular momentum
+and electric and magnetic charges is shown to exist in gauged $N=2$
+supergravity. Stability of a subset of these spacetimes is demonstrated by
+saturation of the Bogomol'nyi bound arising from the supersymmetry algebra. The
+mass of the resulting solitonic black holes is given in terms of the
+cosmological constant and the angular momentum. We conjecture that at the
+quantum level these solitons are dyons with angular momentum determined by the
+electric and magnetic charges.",9512222v1
+1994-11-29,The Drell-Hearn-Gerasimov Sum Rule,"The Drell-Hearn-Gerasimov (DHG) sum rule relates the helicity structure of
+the photoabsorption cross section to the anomalous magnetic moment of the
+nucleon. It is based on Lorentz and gauge invariance, crossing symmetry,
+causality and unitarity. A generalized DHG sum rule my be derived for virtual
+photons. At low momentum transfer this generalized sum rule is saturated by the
+resonance region, at high momentum transfer it may be expressed by the parton
+spin distributions measured in deep inelastic scattering. The
+longitudinal-transverse interference determines the Cottingham sum rule, which
+is related to the electric and magnetic form factors over the whole range of
+momentum transfer.",9411034v1
+2000-01-07,New tests for a singularity of ideal MHD,"Analysis using new calculations with 3 times the resolution of the earlier
+linked magnetic flux tubes confirms the transition from singular to saturated
+growth rate reported by Grauer and Marliani \cite{GrauerMar99} for the
+incompressible cases is confirmed. However, all of the secondary tests point to
+a transition back to stronger growth rate at a different location at late
+times. Similar problems in ideal hydrodynamics are discussed, pointing out that
+initial negative results eventually led to better initial conditions that did
+show evidence for a singularity of Euler. Whether singular or near-singular
+growth in ideal MHD is eventually shown, this study could have bearing on fast
+magnetic reconnection, high energy particle production and coronal heating.",0001016v1
+2007-08-14,Formation of bulk ferromagnetic nanostructured Fe40Ni40P14B6 alloys by metastable liquid spinodal decomposition,"Nanostructured Fe40Ni40P14B6 alloys ingots of diameter 3~5 mm could be
+synthesised by a metastable liquid state spinodal decomposition method. The
+molten Fe40Ni40P14B6 alloy was purified by means of the fluxing technique and
+thus a large undercooling could be achieved. For undercooling Delta T > 260 K,
+the microstructure of the undercooled specimen had exhibited liquid state
+spinodal decomposition in the undercooled liquid state. The microstructure
+could be described as two intertwining networks with small grains dispersed in
+them. For undercooling Delta T > 290 K, the overall microstructure of the
+specimen changed into a granular morphology. The average grain sizes of the
+small and large grains are ~ 30 nm and ~ 80 nm, respectively. These prepared
+samples are soft magnets with saturation magnetization Bs ~0.744 T.",0708.1809v1
+2007-10-06,Spin Anisotropy in ZnCu_3(OH)_6Cl_2,"The spin anisotropic exchange interaction is suggested to contribute
+significantly to the abnormal upturn of the magnetic susceptibility in the
+ZnCu$_3$(OH)$_6$Cl$_2$. The saturation of the magnetic susceptibility below 300
+mK observed in the muon spin resonance ($\mu$SR) experiment is the quantum
+effect of the spin flipping process.",0710.1334v3
+2007-12-01,Solitons in isotropic antiferromagnets: beyond a sigma model,"Isotropic antiferromagnets shows a reach variety of magnetic solitons with
+non-trivial static and dynamic properties. One-dimensional soliton elementary
+excitations have a periodic dispersion law. For two-dimensional case, planar
+antiferromagnetic vortices having non-singular macroscopic core with the
+saturated magnetic moment are present. The dynamic properties of these planar
+antiferromagnetic vortex are characterized by presence of a gyroforce",0712.0073v1
+2008-04-22,Evolution of entanglement entropy following a quantum quench: Analytic results for the XY chain in a transverse magnetic field,"The non-equilibrium evolution of the block entanglement entropy is
+investigated in the XY chain in a transverse magnetic field after the
+Hamiltonian parameters are suddenly changed from and to arbitrary values. Using
+Toeplitz matrix representation and multidimensional phase methods, we provide
+analytic results for large blocks and for all times, showing explicitly the
+linear growth in time followed by saturation. The consequences of these
+analytic results are discussed and the effects of a finite block length is
+taken into account numerically.",0804.3559v1
+2008-06-10,Inelastic Scattering from Local Vibrational Modes,"We study a nonuniversal contribution to the dephasing rate of conduction
+electrons due to local vibrational modes. The inelastic scattering rate is
+strongly influenced by multiphonon excitations, exhibiting oscillatory
+behaviour. For higher frequencies, it saturates to a finite, coupling dependent
+value. In the strong coupling limit, the phonon is almost completely softened,
+and the inelastic cross section reaches its maximal value. This represents a
+magnetic field insensitive contribution to the dephasing time in mesoscopic
+systems, in addition to magnetic impurities.",0806.1680v1
+2008-12-15,Dynamically dominant excitations of string solutions in the spin-1/2 antiferromagnetic Heisenberg chain in magnetic fields,"Using Bethe-ansatz solutions, we uncover a well-defined continuum in
+dynamical structure factor $S^{+-}(k,\omega)$ of the spin-1/2 antiferromagnetic
+Heisenberg chain in magnetic fields. It comes from string solutions which
+continuously connect the mode of the lowest-energy excitations in the
+zero-field limit and that of bound states of overturned spins from the
+ferromagnetic state near the saturation field. We confirm the relevance to real
+materials through comparisons with experimental results.",0812.2707v1
+2009-05-13,Pair Creation of Massless Fermions in Electric Flux Tube,"Using chiral anomaly, we discuss the pair creation of massless fermions in an
+electric flux tube $\vec{E}$ under homogeneous magnetic field $\vec{B}$
+parallel to $\vec{E}$. The tube is axial symmetric and infinitely long in
+longitudinal direction. In the limit $B\gg E$, we can analytically obtain the
+spatial and temporal behaviors of the electric field and azimuthal magnetic
+field generated by the produced fermions. We find that the life time $t_c$ of
+the electric field is shorter as the width of the tube is narrower. Applying it
+to the glasma in high-energy heavy-ion collisions, we find that color electric
+field decays fast such as $t_c\simeq Q_s^{-1}$ with saturation momentum $Q_s$.",0905.2003v1
+2009-07-21,Magnetocaloric effect in quantum spin-s chains,"We compute the entropy of antiferromagnetic quantum spin-s chains in an
+external magnetic field using exact diagonalization and Quantum Monte Carlo
+simulations. The magnetocaloric effect, i.e., temperature variations during
+adiabatic field changes, can be derived from the isentropes. First, we focus on
+the example of the spin-s=1 chain and show that one can cool by closing the
+Haldane gap with a magnetic field. We then move to quantum spin-s chains and
+demonstrate linear scaling with $s$ close to the saturation field. In passing,
+we propose a new method to compute many low-lying excited states using the
+Lanczos recursion.",0907.3736v1
+2009-09-11,Resistive g-modes in a reversed field pinch plasma,"First direct experimental evidence of high frequency, high toroidal mode
+number (n>20), magnetic fluctuations due to unstable resistive interchange
+modes (g-modes) resonant in the edge region of a reversed field pinch (RFP)
+plasma is presented. Experimental characterization of time and space
+periodicities of the modes is provided by means of highly resolved in-vessel
+edge and insertable magnetic diagnostics. It is found that the spectral mode
+properties are in good agreement with the predictions of the theoretical linear
+resistive magnetohydrodynamic stability analysis. A simple model is proposed
+for the observed saturation levels of the modes.",0909.2153v1
+2010-06-03,Obtaining and Application of the Reduced Bloch Equations,"Well-known Bloch equations describe the spin systems (electronic and nuclear)
+for any scale of time, from transient processes to steady states. Usually in
+solids T_2 << T_1. The question arises: what are the approximations that should
+be made in order the ""roughen"" Bloch equations to describe the processes at the
+time T_2 < t < T_1? The answer to this question is given in this article. As an
+example, the saturation of magnetic resonance is considered under the
+conditions of harmonic modulation of a constant magnetic field.",1006.1143v1
+2011-04-12,Interactions and magnetic moments near vacancies and resonant impurities in graphene,"The effect of electronic interactions in graphene with vacancies or resonant
+scatterers is investigated. We apply dynamical mean-field theory in combination
+with quantum Monte Carlo simulations, which allow us to treat
+non-perturbatively quantum fluctuations beyond Hartree-Fock approximations. The
+interactions narrow the width of the resonance and induce a Curie magnetic
+susceptibility, signaling the formation of local moments. The absence of
+saturation of the susceptibility at low temperatures suggests that the coupling
+between the local moment and the conduction electrons is ferromagnetic.",1104.2207v1
+2011-05-20,"Magnetization Dissipation in the Ferromagnetic Semiconductor (Ga,Mn)As","We compute the Gilbert damping in (Ga,Mn)As based on the scattering theory of
+magnetization relaxation. The disorder scattering is included
+non-perturbatively. In the clean limit, the spin-pumping from the localized
+d-electrons to the itinerant holes dominates the relaxation processes. In the
+diffusive regime, the breathing Fermi-surface effect is balanced by the effects
+of interband scattering, which cause the Gilbert damping constant to saturate
+at around 0.005. In small samples, the system shape induces a large anisotropy
+in the Gilbert damping.",1105.4148v2
+2011-08-09,Evidence for spin memory in the electron phase coherence in graphene,"We measure the dependence of the conductivity of graphene as a function of
+magnetic field, temperature and carrier density and discover a saturation of
+the dephasing length at low temperatures that we ascribe to spin memory
+effects. Values of the spin coherence length up to eight microns are found to
+scale with the mean free path. We consider different origins of this effect and
+suggest that it is controlled by resonant states that act as magnetic-like
+defects. By varying the level of disorder, we demonstrate that the spin
+coherence length can be tuned over an order of magnitude.",1108.2067v1
+2012-01-08,Effect of mechanical stresses on the coercive force of the heterophase non-interacting nanoparticles,"The theoretical analysis of the effect of uniaxial stress on the
+magnetization of the system of noninteracting nanoparticles is done by an
+example of heterophase particles of maghemite, epitaxially coated with cobalt
+ferrite. It is shown that stretching leads to a decrease in the coercive force
+$H_c$, and compression leads to its growth. The residual saturation
+magnetization $I_{rs}$ of nanoparticles does not change. With increasing of
+interfacial exchange interaction, coercive force varies nonmonotonically",1201.1629v1
+2012-08-29,Exploring the physical limits of saturation contrast in Magnetic Resonance Imagign,"Magnetic Resonance Imaging has become nowadays an indispensable tool with
+applications ranging from medicine to material science. However, so far the
+physical limits of the maximum achievable experimental contrast were unknown.
+We introduce an approach based on principles of optimal control theory to
+explore these physical limits, providing a benchmark for numerically optimized
+robust pulse sequences which can take into account experimental imperfections.
+This approach is demonstrated experimentally using a model system of two
+spatially separated liquids corresponding to blood in its oxygenated and
+deoxygenated forms.",1208.5865v1
+2013-06-28,Particle Acceleration during Magnetorotational Instability in a Collisionless Accretion Disk,"Particle acceleration during the magnetorotational instability (MRI) in a
+collisionless accretion disk was investigated by using a particle-in-cell (PIC)
+simulation. We discuss the important role that magnetic reconnection plays not
+only on the saturation of MRI but also on the relativistic particle generation.
+The plasma pressure anisotropy of $p_{\perp} > p_{\para}$ induced by the action
+of MRI dynamo leads to rapid growth in magnetic reconnection, resulting in the
+fast generation of nonthermal particles with a hard power-law spectrum. This
+efficient particle acceleration mechanism involved in a collisionless accretion
+disk may be a possible model to explain the origin of high energy particles
+observed around massive black holes.",1306.6720v1
+2013-07-03,Low-temperature thermodynamics of spin-1/2 orthogonal-dimer chain with Ising and Heisenberg interactions,"We consider an exactly solvable version of the quantum spin-1/2
+orthogonal-dimer chain with the Heisenberg intra-dimer and Ising inter-dimer
+couplings. The investigated quantum spin system exhibits at zero temperature
+fractional plateaux at 1/4 and 1/2 of the saturation magnetization and it has a
+highly degenerate ground state at critical fields where the magnetization
+jumps. We study the field dependence of the specific heat at low temperature.
+The lattice-gas description is formulated in a vicinity of critical fields to
+explain the low-temperature behaviour of specific heat.",1307.1005v1
+2013-07-06,Iterative Deconvolution of Quadrupole Split NMR Spectra,"We propose a simple method to deconvolute NMR spectra of quadrupolar nuclei
+in order to separate the distribution of local magnetic hyperfine field from
+the quadrupole splitting. It is based on an iterative procedure which allows to
+express the intensity of a single NMR line directly as a linear combination of
+the intensities of the total experimental spectrum at a few related
+frequencies. This procedure is argued to be an interesting complement to
+Fourier transformation since it can lead to a significant noise reduction in
+some frequency ranges. This is demonstrated in the case of the 11B-NMR spectrum
+in SrCu2(BO3)2 at a field of 31.7 T, where a magnetization plateau at 1/6 of
+the saturation has been observed.",1307.1752v1
+2013-10-04,A Classical Nernst Engine,"We introduce a simple model for an engine based on the Nernst effect. In the
+presence of a magnetic field, a vertical heat current can drive a horizontal
+particle current against a chemical potential. For a microscopic model invoking
+classical particle trajectories subject to the Lorentz force, we prove a
+universal bound 3-2*sqrt(2) simeq 0.172 for the ratio between maximum
+efficiency and Carnot efficiency. This bound, as the slightly lower one 1/6 for
+efficiency at maximum power, can indeed be saturated for large magnetic field
+and small fugacity irrespective of the aspect ratio.",1310.1195v1
+2013-12-05,Magnetic properties of ferromagnetic Pu2Pt3Si5,"The structural, magnetic, and thermodynamic properties of a new plutonium
+based compound, Pu2Pt3Si5, are reported. Single crystals produced by a Sn-flux
+technique have been analyzed showing a ferromagnetic behavior at 58 K.
+Pu2Pt3Si5 crystallizes in the U2Co3Si5-type orthorhombic Iabm structure (72)
+with atomic parameters a = 9.9226(2) \AA, b = 11.4436(2) \AA and c = 6.0148(1)
+\AA. The effective (\mu_eff ~0.74 \mu_B) and saturated (\mu_sat ~0.32 B/Pu)
+moments as well as the Sommerfeld coefficient (\gamma_e ~2 mJ.mol-1.K-2/Pu)
+could point towards 5f localization in this material.",1312.1576v1
+2014-01-16,Low-temperature large-distance asymptotics of the transversal two-point functions of the XXZ chain,"We derive the low-temperature large-distance asymptotics of the transversal
+two-point functions of the XXZ chain by summing up the asymptotically dominant
+terms of their expansion into form factors of the quantum transfer matrix. Our
+asymptotic formulae are numerically efficient and match well with known results
+for vanishing magnetic field and for short distances and magnetic fields below
+the saturation field.",1401.4132v1
+2014-07-03,Inhomogeneous ordering in weakly coupled Heisenberg $S=1/2$ chains with random bonds,"Long range magnetic ordering in the quasi-one-dimensional random-bond
+antiferromagnet BaCu$_2$(Si$_{1-x}$Ge$_{x}$)$_2$O$_7$ is studied in $\mu$SR
+experiments as a function of disorder strength. Compared to the disorder-free
+parent materials, the saturation ordered moment is found to be considerably
+reduced. Moreover, even in weakly disordered species, the magnetically ordered
+state is shown to be highly inhomogeneous. The results are interpreted in terms
+of weakly coupled random spin chains, governed by the ``infinite randomness``
+fixed point.",1407.0813v2
+2014-07-18,Structural and electronic properties of epitaxial YBaCuO/LaCaMnO bilayers grown on SrTiO$_3$ (110) substrates,"Epitaxial bilayers of the high-temperature-superconductor YBa2Cu3O7-d (YBCO)
+and the ferromagnetic metal La0.67Ca0.33MnO3 (LCMO) were prepared by pulsed
+laser deposition on (110)-oriented SrTiO3 substrates, such that the CuO2 planes
+of YBCO are perpendicular to the YBCO-LCMO interface. X-ray diffraction and
+Raman scattering demonstrate complete (110) orientation of both YBCO and LCMO
+overlayers. The resistivity and magnetization of the bilayer films are highly
+anisotropic. The critical temperatures for superconductivity and ferromagnetism
+as well as the saturation magnetization exhibit modest reductions compared to
+corresponding bulk values.",1407.5049v1
+2016-01-14,Optimal Current Waveforms for Switched-Reluctance Motors,"In this paper, we address the problem of finding current waveforms for a
+switched reluctance motor that minimize a user-defined combination of torque
+ripple and RMS current. The motor model we use is fairly general, and includes
+magnetic saturation, voltage and current limits, and highly coupled magnetics
+(and therefore, unconventional geometries and winding patterns). We solve this
+problem by approximating it as a mixed-integer convex program, which we solve
+globally using branch and bound. We demonstrate our approach on an
+experimentally verified model of a fully pitched switched reluctance motor, for
+which we find the globally optimal waveforms, even for high rotor speeds.",1601.03768v1
+2016-02-02,Magnetization Dynamics of Topological Defects and the Spin Solid in Kagome Artificial Spin Ice,"We report broadband spin-wave spectroscopy on kagome artificial spin ice
+(ASI) made of large arrays of interconnected Ni$_{80}$Fe$_{20}$ nanobars.
+Spectra taken in saturated and disordered states exhibit a series of resonances
+with characteristic magnetic field dependencies. Making use of micromagnetic
+simulations, we identify resonances that reflect the spin-solid-state and
+monopole-antimonopole pairs on Dirac strings. The latter resonances allow for
+the generation of highly-charged vertices in ASIs via microwave assisted
+switching. Our findings open further perspectives for fundamental studies on
+ASIs and their usage in reprogrammable magnonics.",1602.00918v1
+2016-02-22,Exchange magnon induced resistance asymmetry in permalloy spin-Hall oscillators,"We investigate magnetization dynamics in a spin-Hall oscillator using a
+direct current measurement as well as conventional microwave spectrum analysis.
+When the current applies an anti-damping spin-transfer torque, we observe a
+change in resistance which we ascribe to the excitation of incoherent exchange
+magnons. A simple model is developed based on the reduction of the effective
+saturation magnetization, quantitatively explaining the data. The observed
+phenomena highlight the importance of exchange magnons on the operation of
+spin-Hall oscillators.",1602.06710v1
+2017-03-28,Gauged BPS baby Skyrmions with quantised magnetic flux,"A new type of gauged BPS baby Skyrme model is presented, where the derivative
+term is just the Schroers current (i.e., gauge invariant and conserved version
+of the topological current) squared. This class of models has a topological
+bound saturated for solutions of the pertinent Bogomolnyi equations
+supplemented by a so-called superpotential equation. In contrast to the gauged
+BPS baby Skyrme models considered previously, the superpotential equation is
+linear and, hence, completely solvable. Furthermore, the magnetic flux is
+quantized in units of $2\pi$, which allows, in principle, to define this theory
+on a compact manifold without boundary, unlike all gauged baby Skyrme models
+considered so far.",1703.09672v1
+2018-04-12,Peculiar magnetic properties of NC6 and NC12 layered compounds from first principles,"In the context of characterizing nitrogen poor carbo-nitrides for different
+applications, identification of an unusual onset of spin polarization of N(p)
+states has been shown. A full saturation up to 3 Bohr magnetons is demonstrated
+in extended two-dimensional carbon networks of C6N and C12N hexagonal
+structures refined based on density functional theory calculations. From
+establishing the energy-volume equations of states in both compounds assuming
+spin degenerate (non spin polarized) and spin-polarized configurations, the
+ground state is identified as ferromagnetic. The variation of magnetization
+with volume points to strongly ferromagnetic behavior",1804.04441v1
+2018-05-01,Optoelectronic spin memories of electrons in semiconductors,"We optically generate electron spins in semiconductors and apply an external
+magnetic field perpendicularly to them. Time-resolved photoluminescence
+measurements, pumped with a circularly polarized light, are performed to study
+the spin polarization and spin memory times in the semiconducting host. The
+measured spin polarization is found to be an exponential decay with the time
+delay of the probe. It is also found that the spin memory times, extracted from
+the polarization decays, enhance with the strength of the external magnetic
+field. However, at higher fields, the memory times get saturated to sub-{\mu}s
+because of the coupling for interacting electrons with the local nuclear field.",1805.00171v1
+2018-05-04,Modeling of graphene Hall effect sensors for microbead detection,"This paper deals with the modeling of sensitivity of epitaxial graphene Hall
+bars, from sub-micrometer to micrometer size, to the stray field generated by a
+magnetic microbead. To demonstrate experiment feasibility, the model is first
+validated by comparison to measurement results, considering an ac-dc detection
+scheme. Then, an exhaustive numerical analysis is performed to investigate
+signal detriment caused by material defects, saturation of bead magnetization
+at high fields, increment of bead distance from sensor surface and device width
+increase.",1805.01779v1
+2018-06-04,Dynamical quadrupole structure factor of frustrated ferromagnetic chain,"We investigate the dynamical quadrupole structure factor of a spin-1/2
+$J_{1}$-$J_{2}$ Heisenberg chain with competing ferromagnetic $J_{1}$ and
+antiferromagnetic $J_{2}$ in a magnetic field by exploiting density-matrix
+renormalization group techniques. In a field-induced spin nematic regime, we
+observe gapless excitations at $q=\pi$ according to quasi-long-range
+antiferro-quadrupole correlations. The gapless excitation mode has a quadratic
+form at the saturation, while it changes into a linear dispersion as the
+magnetization decreases.",1806.01434v1
+2019-05-19,Path-integral Monte Carlo study of electronic states in quantum dots in an external magnetic field,"We explore correlated electron states in harmonically confined few-electron
+quantum dots in an external magnetic field by the path-integral Monte Carlo
+method for a wide range of the field and the Coulomb interaction strength.
+Using the phase structure of a preceding unrestricted Hartree-Fock calculation
+for phase fixing, we find a rich variety of correlated states, often completely
+different from the prediction of mean-field theory. These are finite
+temperature results, but sometimes the correlations saturate with decreasing
+temperature, providing insight into the ground-state properties.",1905.07802v2
+2019-06-24,Graded index lenses for spin wave steering,"We use micromagnetic modelling to demonstrate the operation of graded index
+lenses designed to steer forward-volume magnetostatic spin waves by 90 and 180
+degrees. The graded index profiles require the refractive index to diverge in
+the lens center, which, for spin waves, can be achieved by modulating the
+saturation magnetization or external magnetic field in a ferromagnetic film by
+a small amount. We also show how the 90$^\circ$ lens may be used as a beam
+divider. Finally, we analyse the robustness of the lenses to deviations from
+their ideal profiles.",1906.09985v1
+2020-09-30,Exploring zonal flow mediated saturation on stellarators,"In stellarators, zonal flow activity depends sensitively on geometry of the
+three dimensional magnetic field, via an interplay of mechanisms that is not
+fully understood. In this work, we investigate this by studying three magnetic
+configurations of the Wendelstein 7-X stellarator. We find that variation in
+linear zonal flow damping is accompanied by variation in nonlinear drive, and
+identify key geometric features that control these effects. Understanding the
+resulting balance is important for the development of reduced models of
+turbulent transport.",2009.14750v1
+2022-04-19,Spin correlations in the frustrated ferro-antiferromagnet SrZnVO(PO4)2 near saturation,"Single crystal elastic and inelastic neutron scattering experiments are
+performed on the frustrated ferro-antiferromagnet SrZnVO(PO4)2 in high magnetic
+fields. The fully polarized state, the presaturation phase and the
+columnar-antiferromagnetic phase just bellow the presaturation phase were
+investigated. The observed renormalization of spin wave bandwidths,
+re-distribution of intensities between different branches and non-linearities
+in the magnetization curve are all indicative of strong deviations from
+classical spin wave theory. The previously observed presaturation transition is
+attributed to a staggered pattern of Dzyaloshinskii-Moriya interactions.",2204.08778v2
+2011-02-16,{Rearrangement of the antiferromagnetic ordering at high magnetic fields in SmFeAsO and SmFeAsO$_{0.9}$F$_{0.1}$ single crystals,"The low-temperature antiferromagnetic state of the Sm-ions in both
+nonsuperconducting SmFeAsO and superconducting SmFeAsO$_{0.9}$F$_{0.1}$ single
+crystals was studied by magnetic torque, magnetization, and magnetoresistance
+measurements in magnetic fields up to 60~T and temperatures down to 0.6~K. We
+uncover in both compounds a distinct rearrangement of the antiferromagnetically
+ordered Sm-moments near $35-40$~T. This is seen in both, static and pulsed
+magnetic fields, as a sharp change in the sign of the magnetic torque, which is
+sensitive to the magnetic anisotropy and hence to the magnetic moment in the
+$ab$-plane, ({\it i.e.} the FeAs-layers), and as a jump in the magnetization
+for magnetic fields perpendicular to the conducting planes. This rearrangement
+of magnetic ordering in $35-40$~T is essentially temperature independent and
+points towards a canted or a partially polarized magnetic state in high
+magnetic fields. However, the observed value for the saturation moment above
+this rearrangement, suggests that the complete suppression of the
+antiferromagnetism related to the Sm-moments would require fields in excess of
+60~T. Such a large field value is particularly remarkable when compared to the
+relatively small N\'{e}el temperature $T_{\rm N}\simeq5$~K, suggesting very
+anisotropic magnetic exchange couplings. At the transition, magnetoresistivity
+measurements show a crossover from positive to negative field-dependence,
+indicating that the charge carriers in the FeAs planes are sensitive to the
+magnetic configuration of the rare-earth elements. This is indicates a finite
+magnetic/electronic coupling between the SmO and the FeAs layers which are
+likely to mediate the exchange interactions leading to the long range
+antiferromagnetic order of the Sm ions.",1102.3312v1
+2006-09-27,Simulation of the Magnetothermal Instability,"In many magnetized, dilute astrophysical plasmas, thermal conduction occurs
+almost exclusively parallel to magnetic field lines. In this case, the usual
+stability criterion for convective stability, the Schwarzschild criterion,
+which depends on entropy gradients, is modified. In the magnetized long mean
+free path regime, instability occurs for small wavenumbers when (dP/dz)(dln
+T/dz) > 0, which we refer to as the Balbus criterion. We refer to the
+convective-type instability that results as the magnetothermal instability
+(MTI). We use the equations of MHD with anisotropic electron heat conduction to
+numerically simulate the linear growth and nonlinear saturation of the MTI in
+plane-parallel atmospheres that are unstable according to the Balbus criterion.
+The linear growth rates measured from the simulations are in excellent
+agreement with the weak field dispersion relation. The addition of isotropic
+conduction, e.g. radiation, or strong magnetic fields can damp the growth of
+the MTI and affect the nonlinear regime. The instability saturates when the
+atmosphere becomes isothermal as the source of free energy is exhausted. By
+maintaining a fixed temperature difference between the top and bottom
+boundaries of the simulation domain, sustained convective turbulence can be
+driven. MTI-stable layers introduced by isotropic conduction are used to
+prevent the formation of unresolved, thermal boundary layers. We find that the
+largest component of the time-averaged heat flux is due to advective motions as
+opposed to the actual thermal conduction itself. Finally, we explore the
+implications of this instability for a variety of astrophysical systems, such
+as neutron stars, the hot intracluster medium of galaxy clusters, and the
+structure of radiatively inefficient accretion flows.",0609732v1
+2005-09-04,Itinerant Ferromagnetism and Metamagnetism in Cr Doped Perovskite Ruthenates,"We report results of structural, magnetic and transport properties of single
+crystal CaRu1-xCrxO3 (0&#8804;x&#8804;0.36) and SrRu1-xCrxO3
+(0&#8804;x&#8804;0.30). Cr substitution as low as x=0.08 drives CaRu1-xCrxO3
+from the paramagnetic state to an itinerant ferromagnetic state with
+field-driven first-order metamagnetic transitions leading to a sizeable
+saturation moment (~0.4&#61549;B/f.u.within the ab plane). The ferromagnetism
+occurs abruptly and reaches as high as TC=123 K for x=0.22. The Cr-driven
+ferromagnetism is highly anisotropic, suggesting an important role for
+spin-orbit coupling. Lattice constant and magnetic measurements strongly
+support the valence of the Cr as tetravalent (Cr4+, 3d2 configuration). Cr
+substitution for Ru in SrRuO3 (TC=165 K) enhances the itinerant ferromagnetism,
+with TC reaching 290 K for x=0.30, consistent with Cr-induced ferromagnetism in
+paramagnetic CaRuO3. Preliminary pressure-dependent magnetization of
+CaRu0.85Cr0.15O3 shows strong enhancement of the saturation magnetization (25%
+for P~0.7 GPa). All results indicate a coupling of Ru 4d and Cr 3d electrons
+that is unexpectedly favorable for itinerant ferromagnetism which often exists
+delicately in the ruthenates.",0509084v1
+1995-07-31,Singular BPS Saturated States and Enhanced Symmetries of Four-Dimensional N=4 Supersymmetric String Vacua,"A class of supersymmetric (BPS saturated), static, spherically symmetric
+solutions of four-dimensional effective N=4 supersymmetric superstring vacua,
+which become massless at special points of moduli space, is studied in terms of
+the fields of the effective heterotic string theory compactified on a
+six-torus. Those are singular four-dimensional solutions corresponding to
+$O(6,22,Z)$ orbits of dyonic configurations (with zero axion), whose
+left-moving as well as right-moving electric and magnetic charges are
+orthogonal (light-like in the $O(6,22,Z)$ sense), while the $O(6,22,Z)$ norms
+of both the electric and magnetic charges are negative. Purely electric [or
+purely magnetic] and dyonic configurations preserve $1\over 2$ and $1\over 4$
+of N=4 supersymmetry, respectively, thus belonging to the vector and the
+highest spin $3\over 2$ supermultiplets, respectively. Purely electric [or
+purely magnetic] solutions (along with an infinite tower of $SL(2,Z)$
+transformed states) become massless at a point of the corresponding
+``one-torus'', thus may contribute to the enhancement of non-Abelian gauge
+symmetry, while dyonic solutions become simultaneously massless at a point of
+the corresponding two-torus, and thus may in addition contribute to the
+enhancement of the local supersymmetry there.",9507160v3
+2007-05-02,Angular Momentum Transport in Accretion Disks: Scaling Laws in MRI-driven Turbulence,"We present a scaling law that predicts the values of the stresses obtained in
+numerical simulations of saturated MRI-driven turbulence in non-stratified
+shearing boxes. It relates the turbulent stresses to the strength of the
+vertical magnetic field, the sound speed, the vertical size of the box, and the
+numerical resolution and predicts accurately the results of 35 numerical
+simulations performed for a wide variety of physical conditions. We use our
+result to show that the saturated stresses in simulations with zero net
+magnetic flux depend linearly on the numerical resolution and would become
+negligible if the resolution were set equal to the natural dissipation scale in
+astrophysical disks. We conclude that, in order for MRI-driven turbulent
+angular momentum transport to be able to account for the large value of the
+effective alpha viscosity inferred observationally, the disk must be threaded
+by a significant vertical magnetic field and the turbulent magnetic energy must
+be in near equipartition with the thermal energy. This result has important
+implications for the spectra of accretion disks and their stability.",0705.0352v2
+2008-01-08,"Nano granular metallic Fe - oxygen deficient TiO$_{2-δ}$ composite films: A room temperature, highly carrier polarized magnetic semiconductor","Nano granular metallic iron (Fe) and titanium dioxide (TiO$_{2-\delta}$) were
+co-deposited on (100) lanthanum aluminate (LaAlO$_3$) substrates in a low
+oxygen chamber pressure using a pulsed laser ablation deposition (PLD)
+technique. The co-deposition of Fe and TiO$_2$ resulted in $\approx$ 10 nm
+metallic Fe spherical grains suspended within a TiO$_{2-\delta}$ matrix. The
+films show ferromagnetic behavior with a saturation magnetization of 3100 Gauss
+at room temperature. Our estimate of the saturation magnetization based on the
+size and distribution of the Fe spheres agreed well with the measured value.
+The film composite structure was characterized as p-type magnetic semiconductor
+at 300 K with a carrier density of the order of $ 10^{22} /{\rm cm^3}$. The
+hole carriers were excited at the interface between the nano granular Fe and
+TiO$_{2-\delta}$ matrix similar to holes excited in the metal/n-type
+semiconductor interface commonly observed in Metal-Oxide-Semiconductor (MOS)
+devices. From the large anomalous Hall effect directly observed in these films
+it follows that the holes at the interface were strongly spin polarized.
+Structure and magneto transport properties suggested that these PLD films have
+potential nano spintronics applications.",0801.1285v1
+2009-01-28,Detailed Analysis of Filamentary Structure in the Weibel Instability,"We present results of a 2D3V kinetic Vlasov simulation of the Weibel
+instability. The kinetic Vlasov simulation allows us to investigate the
+velocity distribution of dilute plasmas, in which the effect of collisions
+between particles is negligible, and has the advantage that the accuracy of the
+calculated velocity distribution does not depend on the density of plasmas at
+each point in the physical space. We succeed in reproducing some features of
+the Weibel instability shown by other simulations, for example, the
+exponentially growing phase, the saturation of the magnetic field strength, the
+formation of filamentary structure, and the coalescence of the filaments.
+Especially, we concentrate on the behavior of the filaments after the
+saturation of the magnetic field strength and find that there is a kind of
+quasi-equilibrium states before the coalescence occurs. Furthermore, it is
+found that an analytical solution for stationary states of the 2D3V
+Vlasov-Maxwell system can reproduce some dominant features of the
+quasi-equilibrium, e.g, the configuration of the magnetic field and the
+velocity distribution at each point. The analytical expression could give a
+plausible model for the transition layer of a collisionless shock where a
+strong magnetic field generated by the Weibel instability provides an effective
+dissipation process instead of collisions between particles.",0901.4402v1
+2012-08-22,The kinetic helicity needed to drive large-scale dynamos,"Magnetic field generation on scales large compared with the scale of the
+turbulent eddies is known to be possible via the so-called $\alpha$ effect when
+the turbulence is helical and if the domain is large enough for the $\alpha$
+effect to dominate over turbulent diffusion. Using three-dimensional turbulence
+simulations, we show that the energy of the resulting mean magnetic field of
+the saturated state increases linearly with the product of normalized helicity
+and the ratio of domain scale to eddy scale, provided this product exceeds a
+critical value of around unity. This implies that large-scale dynamo action
+commences when the normalized helicity is larger than the inverse scale ratio.
+Our results show that the emergence of small-scale dynamo action does not have
+any noticeable effect on the large-scale dynamo. Recent findings by Pietarila
+Graham et al. (2012, Phys. Rev. E85, 066406) of a smaller minimal helicity may
+be an artifact due to the onset of small-scale dynamo action at large magnetic
+Reynolds numbers. However, the onset of large-scale dynamo action is difficult
+to establish when the kinetic helicity is small. Instead of random forcing,
+they used an ABC-flow with time-dependent phases. We show that such dynamos
+saturate prematurely in a way that is reminiscent of inhomogeneous dynamos with
+internal magnetic helicity fluxes. Furthermore, even for very low fractional
+helicities, such dynamos display large-scale fields that change direction,
+which is uncharacteristic of turbulent dynamos.",1208.4529v2
+2012-12-06,"Equilibrium disks, MRI mode excitation, and steady state turbulence in global accretion disk simulations","Global three dimensional magnetohydrodynamic (MHD) simulations of turbulent
+accretion disks are presented which start from fully equilibrium initial
+conditions in which the magnetic forces are accounted for and the induction
+equation is satisfied. The local linear theory of the magnetorotational
+instability (MRI) is used as a predictor of the growth of magnetic field
+perturbations in the global simulations. The linear growth estimates and global
+simulations diverge when non-linear motions - perhaps triggered by the onset of
+turbulence - upset the velocity perturbations used to excite the MRI. The
+saturated state is found to be independent of the initially excited MRI mode,
+showing that once the disk has expelled the initially net flux field and
+settled into quasi-periodic oscillations in the toroidal magnetic flux, the
+dynamo cycle regulates the global saturation stress level. Furthermore,
+time-averaged measures of converged turbulence, such as the ratio of magnetic
+energies, are found to be in agreement with previous works. In particular, the
+globally averaged stress normalized to the gas pressure, <\alpha_{\rm P}> =
+0.034, with notably higher values achieved for simulations with higher
+azimuthal resolution. Supplementary tests are performed using different
+numerical algorithms and resolutions. Convergence with resolution during the
+initial linear MRI growth phase is found for 23-35 cells per scaleheight (in
+the vertical direction).",1212.1306v1
+2013-08-28,Quantum phase diagram of the $S=1/2$ triangular-lattice antiferromagnet Ba$_3$CoSb$_2$O$_9$,"The magnetic phases of the ideal spin-1/2 triangular-lattice antiferromagnet
+Ba$_3$CoSb$_2$O$_9$ are identified and studied using $^{135,137}$Ba nuclear
+magnetic resonance (NMR) spectroscopy in magnetic fields ranging to 30T,
+oriented parallel and near perpendicular to the crystallographic $ab$-plane.
+For both directions, the saturation field is approximately 33T. Notably, the
+NMR spectra provide microscopic evidence for the stabilization of an up-up-down
+spin configuration for in-plane fields, giving rise to an one-third
+magnetization plateau ($M_\text{sat}/3$), as well as for a higher field phase
+transition near to $\sim (3/5)M_\text{sat}$ for both field orientations. Phase
+transitions are signaled by the evolution of the NMR spectra, and in some cases
+through spin-lattice relaxation measurements. The results are compared with
+expectations obtained from a semi-classical energy density modeling, in which
+quantum effects are incorporated by effective interactions extracted from the
+spin-wave analysis of the two-dimensional model. The interlayer coupling also
+plays a significant role in the outcome. Good agreement between the model and
+the experimental results is achieved, except for the case of fields approaching
+the saturation value applied along the c-axis.",1308.6331v2
+2015-07-17,Hard-core boson approach to the spin-1/2 triangular-lattice antiferromagnet Cs$_2$CuCl$_4$ at finite temperatures in magnetic fields higher than the saturation field,"We study the high magnetic field regime of the antiferromagnetic insulator
+Cs$_2$CuCl$_4$ by expressing the spin-1/2 operators in the relevant Heisenberg
+model in terms of hard-core bosons and implementing the hard-core constraint
+via an infinite on-site interaction. We focus on the case where the external
+magnetic field exceeds the saturation field $B_{c}\approx8.5\;\mathrm{T}$ and
+is oriented along the crystallographic $a$ axis perpendicular to the lattice
+plane. Because in this case the excited states are separated by an energy gap
+from the ground state, we may use the self-consistent ladder approximation to
+take the strong correlations due to the hard-core constraint into account. In
+Cs$_2$CuCl$_4$ there are additional interactions besides the hard-core
+interaction which we treat in self-consistent Hartree-Fock approximation. We
+calculate the spectral function of the hard-core bosons from which we obtain
+the in-plane components of the dynamic structure factor, the magnetic
+susceptibility, and the specific heat. Our results for the specific heat are in
+good agreement with the available experimental data. We conclude that the
+self-consistent ladder approximation in combination with a self-consistent
+Hartree-Fock decoupling of the non-hard-core interactions gives an accurate
+description of the physical properties of gapped hard-core bosons in two
+dimensions at finite temperatures.",1507.04957v2
+2019-04-05,"Cluster-based Haldane phases, bound magnon crystals and quantum spin liquids of a mixed spin-1 and spin-1/2 Heisenberg octahedral chain","The mixed spin-1 and spin-1/2 Heisenberg octahedral chain with regularly
+alternating monomeric spin-1 sites and square-plaquette spin-1/2 sites is
+investigated using variational technique, localized-magnon approach, exact
+diagonalization (ED) and density-matrix renormalization group (DMRG) method.
+The investigated model has in a magnetic field an extraordinarily rich
+ground-state phase diagram, which includes the uniform and cluster-based
+Haldane phases, two ferrimagnetic phases of Lieb-Mattis type, two quantum spin
+liquids and two bound magnon crystals in addition to the fully polarized
+ferromagnetic phase. The lowest-energy eigenstates in a highly-frustrated
+parameter region belong to flat bands and hence, low-temperature thermodynamics
+above the bound magnon-crystal ground states can be satisfactorily described
+within the localized-magnon approach. The variational method provides an exact
+evidence for the magnon-crystal phase with a character of the monomer-tetramer
+ground state at zero field, while another magnon-crystal phase with a single
+bound magnon at each square plaquette is found in a high-field region. A
+diversity of quantum ground states gives rise to manifold zero-temperature
+magnetization curves, which may involve up to four wide intermediate plateaus
+at zero, one-sixth, one-third and two-thirds of the saturation magnetization,
+two quantum spin-liquid regions and two tiny plateaus at one-ninth and
+one-twelfth of the saturation magnetization corresponding to the fragmentized
+cluster-based Haldane phases.",1904.02889v2
+2021-03-06,Exceptional spectrum and dynamic magnetization,"A macroscopic effect can be induced by a local non-Hermitian term in a
+many-body system, when it manifests simultaneously level coalescence of a full
+real degeneracy spectrum, leading to exceptional spectrum. In this paper, we
+propose a family of systems that support such an intriguing property. It is
+generally consisted of two arbitrary identical Hermitian sub-lattices in
+association with unidirectional couplings between them. We show exactly that
+all single-particle eigenstates coalesce in pairs even only single
+unidirectional coupling appears. It means that all possible initial states obey
+the exceptional dynamics, resulting in some macroscopic phenomena, which never
+appears in a Hermitian system. As an application, we study the dynamic
+magnetization induced by complex fields in an itinerant electron system. It
+shows that an initial saturated ferromagnetic state at half-filling can be
+driven into its opposite state according to the dynamics of high-order
+exceptional point. Any Hermitian quench term cannot realize a steady opposite
+saturated ferromagnetic state. Numerical simulations for the dynamical
+processes of magnetization are performed for several representative situations,
+including lattice dimensions, global random and local impurity distributions.
+It shows that the dynamic magnetization processes exhibit universal behavior.",2103.04109v2
+2021-03-29,Topological response of the anomalous Hall effect in MnBi2Te4 due to magnetic canting,"Three-dimensional (3D) compensated MnBi2Te4 is antiferromagnetic, but
+undergoes a spin-flop transition at intermediate fields, resulting in a canted
+phase before saturation. In this work, we experimentally show that the
+anomalous Hall effect (AHE) in MnBi2Te4 originates from a topological response
+that is sensitive to the perpendicular magnetic moment and to its canting
+angle. Synthesis by molecular beam epitaxy allows us to obtain a large-area
+quasi-3D 24-layer MnBi2Te4 with near-perfect compensation that hosts the phase
+diagram observed in bulk which we utilize to probe the AHE. This AHE is seen to
+exhibit an antiferromagnetic response at low magnetic fields, and a clear
+evolution at intermediate fields through surface and bulk spin-flop transitions
+into saturation. Throughout this evolution, the AHE is super-linear versus
+magnetization rather than the expected linear relationship. We reveal that this
+discrepancy is related to the canting angle, consistent with the symmetry of
+the crystal. Our findings suggests that novel topological responses may be
+found in non-collinear ferromagnetic, and antiferromagnetic phases.",2103.15801v3
+2021-10-26,Magneto-Thermal Instability In Galaxy Clusters I: Theory and Two-Dimensional Simulations,"Determining the origin of turbulence in galaxy clusters, and quantifying its
+transport of heat, is an outstanding problem, with implications for our
+understanding of their thermodynamic history and structure. As the dilute
+plasma of the intracluster medium (ICM) is magnetized, heat and momentum travel
+preferentially along magnetic field lines. This anisotropy triggers a class of
+buoyancy instabilities that destabilize the ICM, and whose turbulent motions
+can augment or impede heat transport. We focus on the magneto-thermal
+instability (MTI), which may be active in the periphery of galaxy clusters. We
+aim to take a fresh look at the problem and construct a general theory that
+explains the MTI saturation mechanism and provides scalings and estimates for
+the turbulent kinetic energy, magnetic energy, and heat flux. We simulate MTI
+turbulence with a Boussinesq code, SNOOPY, which, in contrast to previous work,
+allows us to perform an extensive sampling of the parameter space. In two
+dimensions the saturation mechanism involves an inverse cascade carrying
+kinetic energy from the short MTI injection scales to larger scales, where it
+is arrested by the stable entropy stratification; at a characteristic ""buoyancy
+scale"", the energy is dumped into large-scale g-modes, which subsequently
+dissipate. Consequently, the entropy stratification sets an upper limit on the
+size and strength of turbulent eddies. Meanwhile, the MTI conveys a substantial
+fraction of heat, despite the tangled geometry of the magnetic field. In a
+companion paper, these results are extended to three-dimensional flows, and
+compared to real cluster observations.",2110.13918v1
+2021-11-05,Interlayer exciton valley polarization dynamics in large magnetic fields,"In van der Waals heterostructures (HS) consisting of stacked MoSe$_2$ and
+WSe$_2$ monolayers, optically bright interlayer excitons (ILE) can be observed
+when the constituent layers are crystallographically aligned. The symmetry of
+the monolayers allows for two different types of alignment, in which the
+momentum-direct interlayer transitions are either valley-conserving (R-type
+alignment) or changing the valley index (H-type anti-alignment). Here, we study
+the valley polarization dynamics of ILE in magnetic fields up to 30~Tesla by
+time-resolved photoluminescence (PL). For all ILE types, we find a finite
+initial PL circular degree of polarization ($DoP$) after unpolarized excitation
+in applied magnetic fields. For ILE in H-type HS, we observe a systematic
+increase of the PL $DoP$ with time in applied magnetic fields, which saturates
+at values close to unity for the largest fields. By contrast, for ILE in R-type
+HS, the PL $DoP$ shows a decrease and a zero crossing before saturating with
+opposite polarization. This unintuitive behavior can be explained by a model
+considering the different ILE states in H- and R-type HS and their selection
+rules coupling PL helicity and valley polarization.",2111.03336v1
+2022-01-31,Magnetostriction in microwave synthesized La0.5Ba0.5CoO3,"A single-phase polycrystalline La0.5Ba0.5CoO3-d sample was synthesized by
+microwave irradiation within 20 minutes of processing time and its structural,
+magnetic, electrical, and magnetostrictive properties were investigated. While
+the temperature dependence of field-cooled magnetization (M) in a field of H =
+0.5 kOe indicates the onset of ferromagnetic transition at TC = 177 K,
+irreversibility between the zero field-cooled and field cooled M(T) persists
+even at H = 3 kOe. M(H) at 10 K does not saturate at the maximum available
+field and has a much smaller value (0.87 {\mu}B/Co in a field of 50 kOe) than
+1.9 {\mu}B/Co expected for spin-only contribution from intermediate Co3+ and
+Co4+ spins. The resistivity shows insulating behavior down to 10 K and only a
+small magnetoresistance (~ 2% for H = 70 kOe) occurs around TC. All these
+results suggest a magnetically heterogeneous ground state with weakly
+interacting ferromagnetic clusters coexisting with a non-ferromagnetic phase.
+The length of the sample expands in the direction of the applied magnetic field
+(positive magnetostriction) and does not show saturation even at 50 kOe. The
+magnetostriction has a maximum value (= 252 ppm) at 10 K and it decreases with
+increasing temperature. The smaller value of magnetostriction compared to the
+available data on La0.5Sr0.5CoO3 suggests that non-ferromagnetic matrix is most
+likely antiferromagnetic and it restrains the field-induced expansion of
+ferromagnetic clusters in the microwave synthesized La0.5Ba0.5CoO3-d sample.",2201.12979v1
+2022-03-22,Unconventional spin frustration due to two competing ferromagnetic interactions of a spin-1/2 Ising-Heisenberg model on martini and martini-diced lattice,"The spin-1/2 Ising-Heisenberg model on martini and martini-diced lattice is
+exactly solved using a star-triangle transformation, which affords an exact
+mapping correspondence to an effective spin-1/2 Ising model on a triangular
+lattice. The ground-state phase diagram of both investigated quantum spin
+models display two spontaneously ordered ferromagnetic phases and one
+macroscopically degenerate disordered phase. In contrast to a classical
+ferromagnetic phase where the spontaneous magnetization of the Ising as well as
+Heisenberg spins acquire fully saturated values the spontaneous magnetization
+of the Heisenberg spins is subject to a quantum reduction to one-third of its
+saturated value within a quantum ferromagnetic phase. The spontaneous
+magnetization and logarithmic divergence of the specific heat as the most
+essential features of both ferromagnetic phases disappear whenever the
+investigated quantum spin model is driven to the highly degenerate disordered
+phase. The disordered phase with nonzero residual entropy originates either
+from a geometric spin frustration caused by antiferromagnetic interactions or
+more strikingly it may also alternatively arise from a competition of the
+ferromagnetic Ising and Heisenberg interactions of easy-axis and easy-plane
+type, respectively. All three available ground states coexist together at a
+single triple point, around which anomalous magnetic and thermodynamic behavior
+can be detected.",2203.11582v1
+2022-05-04,Magnetized oscillatory double-diffusive convection,"We study the properties of oscillatory double-diffusive convection (ODDC) in
+the presence of a uniform vertical background magnetic field. ODDC takes place
+in stellar regions that are unstable according to the Schwarzschild criterion
+and stable according to the Ledoux criterion (sometimes called semiconvective
+regions), which are often predicted to reside just outside the core of
+intermediate-mass main sequence stars. Previous hydrodynamic studies of ODDC
+have shown that the basic instability saturates into a state of weak wave-like
+convection, but that a secondary instability can sometimes transform it into a
+state of layered convection, where layers then rapidly merge and grow until the
+entire region is fully convective. We find that magnetized ODDC has very
+similar properties overall, with some important quantitative differences. A
+linear stability analysis reveals that the fastest-growing modes are unaffected
+by the field, but that other modes are. Numerically, the magnetic field is seen
+to influence the saturation of the basic instability, overall reducing the
+turbulent fluxes of temperature and composition. This in turn affects layer
+formation, usually delaying it, and occasionally suppressing it entirely for
+sufficiently strong fields. Further work will be needed, however, to determine
+the field strength above which layer formation is actually suppressed in stars.
+Potential observational implications are briefly discussed.",2205.02251v2
+2022-11-17,Delayed Hopf bifurcation and control of a ferrofluid interface via a time-dependent magnetic field,"A ferrofluid droplet confined in a Hele-Shaw cell can be deformed into a
+stably spinning ``gear,'' using crossed magnetic fields. Previously, fully
+nonlinear simulation revealed that the spinning gear emerges as a stable
+traveling wave along the droplet's interface bifurcates from the trivial
+(equilibrium) shape. In this work, a center manifold reduction is applied to
+show the geometrical equivalence between a two-harmonic-mode coupled system of
+ordinary differential equations arising from a weakly nonlinear analysis of the
+interface shape and a Hopf bifurcation. The rotating complex amplitude of the
+fundamental mode saturates to a limit circle as the periodic traveling wave
+solution is obtained. An amplitude equation is derived from a
+multiple-time-scale expansion as a reduced model of the dynamics. Then,
+inspired by the well-known delay behavior of time-dependent Hopf bifurcations,
+we design a slowly time-varying magnetic field such that the timing and
+emergence of the interfacial traveling wave can be controlled. The proposed
+theory allows us to determine the time-dependent saturated state resulting from
+the dynamic bifurcation and delayed onset of instability. The amplitude
+equation also reveals hysteresis-like behavior upon time reversal of the
+magnetic field. The state obtained upon time reversal differs from the state
+obtained during the initial (forward-time) period, yet it can still be
+predicted by the proposed reduced-order theory.",2211.09758v3
+2004-06-14,"Nonlinear theory of a ""shear-current"" effect and mean-field magnetic dynamos","The nonlinear theory of a ""shear-current"" effect in a nonrotating and
+nonhelical homogeneous turbulence with an imposed mean velocity shear is
+developed. The ''shear-current"" effect is associated with the $\bar{\bf W} {\bf
+\times} \bar{\bf J}$-term in the mean electromotive force and causes the
+generation of the mean magnetic field even in a nonrotating and nonhelical
+homogeneous turbulence (where $\bar{\bf W}$ is the mean vorticity and $\bar{\bf
+J}$ is the mean electric current). It is found that there is no quenching of
+the nonlinear ""shear-current"" effect contrary to the quenching of the nonlinear
+$\alpha$-effect, the nonlinear turbulent magnetic diffusion, etc. During the
+nonlinear growth of the mean magnetic field, the ''shear-current"" effect only
+changes its sign at some value $\bar{\bf B}_\ast$ of the mean magnetic field.
+The magnitude $\bar{\bf B}_\ast$ determines the level of the saturated mean
+magnetic field which is less than the equipartition field. It is shown that the
+background magnetic fluctuations due to the small-scale dynamo enhance the
+""shear-current"" effect, and reduce the magnitude $\bar{\bf B}_\ast$. When the
+level of the background magnetic fluctuations is larger than 1/3 of the kinetic
+energy of the turbulence, the mean magnetic field can be generated due to the
+""shear-current"" effect for an arbitrary exponent of the energy spectrum of the
+velocity fluctuations.",0406328v2
+2002-09-19,"Magnetic Interactions and Transport in (Ga,Cr)As","The magnetic, transport, and structural properties of (Ga,Cr)As are reported.
+Zincblende Ga$_{1-x}$Cr$_{x}$As was grown by low-temperature molecular beam
+epitaxy (MBE). At low concentrations, x$\sim$0.1, the materials exhibit unusual
+magnetic properties associated with the random magnetism of the alloy. At low
+temperatures the magnetization M(B) increases rapidly with increasing field due
+to the alignment of ferromagnetic units (polarons or clusters) having large
+dipole moments of order 10-10$^2$$\mu_B$. A standard model of
+superparamagnetism is inadequate for describing both the field and temperature
+dependence of the magnetization M(B,T). In order to explain M(B) at low
+temperatures we employ a distributed magnetic moment (DMM) model in which
+polarons or clusters of ions have a distribution of moments. It is also found
+that the magnetic susceptibility increases for decreasing temperature but
+saturates below T=4 K. The inverse susceptibility follows a linear-T
+Curie-Weiss law and extrapolates to a magnetic transition temperature
+$\theta$=10 K. In magnetotransport measurements, a room temperature resistivity
+of $\rho$=0.1 $\Omega$cm and a hole concentration of $\sim10^{20}$ cm$^{-3}$
+are found, indicating that Cr can also act as a acceptor similar to Mn. The
+resistivity increases rapidly for decreasing temperature below room
+temperature, and becomes strongly insulating at low temperatures. The
+conductivity follows exp[-(T$_1$/T)$^{1/2}$] over a large range of
+conductivity, possible evidence of tunneling between polarons or clusters.",0209477v2
+2005-11-04,Magnetic Inhomogeneity and Magnetotransport in Electron-Doped Ca(1-x)La(x)MnO(3) (0<=x<=0.10),"The dc magnetization (M) and electrical resistivity (\rho) as functions of
+magnetic field and temperature are reported for a series of lightly electron
+dopedCa(1-x)La(x)MnO(3) (0<=x<=0.10) specimens for which magnetization [Phys.
+Rev. B {\bf 61}, 14319 (2000)] and scattering studies [Phys. Rev. B {\bf 68},
+134440 (2003)] indicate an inhomogeneous magnetic ground state composed of
+ferromagnetic (FM) droplets embedded in a G-type antiferromagnetic matrix. A
+change in the magnetic behavior near x=0.02 has been suggested to be the
+signature of a crossover to a long-ranged spin-canted phase. The data reported
+here provide further detail about this crossover in the magnetization, and
+additional insight into the origin of this phenomenon through its manifestation
+in the magnetotransport. In the paramagnetic phase (T>=125 K) we find a
+magnetoresistance =-C(M/M_S)^2 (M_S is the low-T saturation magnetization), as
+observed in many manganites in the ferromagnetic (FM), colossal
+magnetoresistance (CMR) region of the phase diagram, but with a value of C that
+is two orders of magnitude smaller than observed for CMR materials. The doping
+behavior C(x) follows that of M_S(x), indicating that electronic inhomogeneity
+associated with FM fluctuations occurs well above the magnetic ordering
+transition.",0511117v1
+2007-12-06,Magnetohydrodynamic Simulations of Disk Galaxy Formation: the Magnetization of The Cold and Warm Medium,"Using magnetohydrodynamic (MHD) adaptive mesh refinement simulations, we
+study the formation and early evolution of disk galaxies with a magnetized
+interstellar medium. For a $10^{10}$ \msun halo with initial NFW dark matter
+and gas profiles, we impose a uniform $10^{-9}$ G magnetic field and follow its
+collapse, disk formation and evolution up to 1 Gyr. Comparing to a purely
+hydrodynamic simulation with the same initial condition, we find that a
+protogalactic field of this strength does not significantly influence the
+global disk properties. At the same time, the initial magnetic fields are
+quickly amplified by the differentially rotating turbulent disk. After the
+initial rapid amplification lasting $\sim500$ Myr, subsequent field
+amplification appears self-regulated. As a result, highly magnetized material
+begin to form above and below the disk. Interestingly, the field strengths in
+the self-regulated regime agrees well with the observed fields in the Milky Way
+galaxy both in the warm and the cold HI phase and do not change appreciably
+with time. Most of the cold phase shows a dispersion of order ten in the
+magnetic field strength. The global azimuthal magnetic fields reverse at
+different radii and the amplitude declines as a function of radius of the disk.
+By comparing the estimated star formation rate (SFR) in hydrodynamic and MHD
+simulations, we find that after the magnetic field strength saturates, magnetic
+forces provide further support in the cold gas and lead to a decline of the
+SFR.",0712.0872v1
+2008-09-25,"Experimental magnetic form factors in Co3V2O8: A combined study of ab initio calculations, magnetic Compton scattering and polarized neutron diffraction","We present a combination of ab initio calculations, magnetic Compton
+scattering and polarized neutron experiments, which elucidate the density
+distribution of unpaired electrons in the kagome staircase system Co3V2O8. Ab
+initio wave functions were used to calculate the spin densities in real and
+momentum space, which show good agreement with the respective experiments. It
+has been found that the spin polarized orbitals are equally distributed between
+the t2g and the eg levels for the spine (s) Co ions, while the eg orbitals of
+the cross-tie (c) Co ions only represent 30% of the atomic spin density.
+Furthermore, the results reveal that the magnetic moments of the cross-tie Co
+ions, which are significantly smaller than those of the spine Co ions in the
+zero-field ferromagnetic structure, do not saturate by applying an external
+magnetic field of 2 T along the easy axis a, but that the increasing bulk
+magnetization originates from induced magnetic moments on the O and V sites.
+The refined individual magnetic moments are mu(Co_c)=1.54(4) mu_B,
+mu(Co_s)=2.87(3) mu_B, mu(V)=0.41(4) mu_B, mu(O1)=0.05(5) mu_B, mu(O2)=0.35(5)
+mu_B, and; mu(O3)=0.36(5) mu_B combining to the same macroscopic magnetization
+value, which was previously only attributed to the Co ions.",0809.4404v2
+2009-06-17,Interplay of frustration and magnetic field in the two-dimensional quantum antiferromagnet Cu(tn)Cl$_2$,"Specific heat and ac magnetic susceptibility measurements, spanning low
+temperatures ($T \geq 40$ mK) and high magnetic fields ($B \leq 14$ T), have
+been performed on a two-dimensional (2D) antiferromagnet Cu(tn)Cl$_{2}$ (tn =
+C$_{3}$H$_{10}$N$_{2}$). The compound represents an $S = 1/2$ spatially
+anisotropic triangular magnet realized by a square lattice with
+nearest-neighbor ($J/k_{B} = 3$ K), frustrating next-nearest-neighbor ($0 <
+J^{\prime}/J < 0.6$), and interlayer ($|J^{\prime \prime}/J| \approx 10^{-3}$)
+interactions. The absence of long-range magnetic order down to $T = $ 60 mK in
+$B = 0$ and the $T^{2}$ behavior of the specific heat for $T \leq 0.4$ K and $B
+\geq 0$ are considered evidence of high degree of 2D magnetic order. In fields
+lower than the saturation field, $B_{\text{sat}} = 6.6$ T, a specific heat
+anomaly, appearing near 0.8 K, is ascribed to bound vortex-antivortex pairs
+stabilized by the applied magnetic field. The resulting magnetic phase diagram
+is remarkably consistent with the one predicted for the ideal square lattice,
+except that $B_{\text{sat}}$ is shifted to values lower than expected.
+Potential explanations for this observation, as well as the possibility of a
+Berezinski-Kosterlitz-Thouless (BKT) phase transition in a spatially
+anisotropic triangular magnet with the N\'{e}el ground state, are discussed.",0906.3181v1
+2009-12-01,Aperiodic magnetic turbulence produced by relativistic ion beams,"Magnetic-field generation by a relativistic ion beam propagating through an
+electron-ion plasma along a homogeneous magnetic field is investigated with
+2.5D high-resolution particle-in-cell (PIC) simulations. The studies test
+predictions of a strong amplification of short-wavelength modes of magnetic
+turbulence upstream of nonrelativistic and relativistic parallel shocks
+associated with supernova remnants, jets of active galactic nuclei, and
+gamma-ray bursts. We find good agreement in the properties of the turbulence
+observed in our simulations compared with the dispersion relation calculated
+for linear waves with arbitrary orientation of ${\vec k}$. Depending on the
+parameters, the backreaction on the ion beam leads to filamentation of the
+ambient plasma and the beam, which in turn influences the properties of the
+magnetic turbulence. For mildly- and ultra-relativistic beams, the instability
+saturates at field amplitudes a few times larger than the homogeneous magnetic
+field strength. This result matches our recent studies of nonrelativistically
+drifting, hot cosmic-ray particles upstream of supernova-remnant shocks which
+indicated only a moderate magnetic-field amplification by nonresonant
+instabilities. We also demonstrate that the aperiodic turbulence generated by
+the beam can provide efficient particle scattering with a rate compatible with
+Bohm diffusion. Representing the ion beam as a constant external current, i.e.
+excluding a backreaction of the magnetic turbulence on the beam, we observe
+non-resonant parallel modes with wavelength and growth rate as predicted by
+analytic calculations. In this unrealistic setup the magnetic field is
+amplified to amplitudes far exceeding the homogeneous field, as observed in
+recent MHD and PIC simulations.",0912.0101v1
+2010-04-26,Magnetic helicity fluxes in an alpha-squared dynamo embedded in a halo,"We present the results of simulations of forced turbulence in a slab where
+the mean kinetic helicity has a maximum near the mid-plane, generating
+gradients of magnetic helicity of both large and small-scale fields. We also
+study systems that have poorly conducting buffer zones away from the midplane
+in order to assess the effects of boundaries. The dynamical alpha quenching
+phenomenology requires that the magnetic helicity in the small-scale fields
+approaches a nearly static, gauge independent state. To stress-test this steady
+state condition we choose a system with a uniform sign of kinetic helicity, so
+that the total magnetic helicity can reach a steady state value only through
+fluxes through the boundary, which are themselves suppressed by the velocity
+boundary conditions. Even with such a set up, the small-scale magnetic helicity
+is found to reach a steady state. In agreement with earlier work, the magnetic
+helicity fluxes of small-scale fields are found to be turbulently diffusive. By
+comparing results with and without halos, we show that artificial constraints
+on magnetic helicity at the boundary do not have a significant impact on the
+evolution of the magnetic helicity, except that ""softer"" (halo) boundary
+conditions give a lower energy of the saturated mean magnetic field.",1004.4591v1
+2011-04-13,The spin-half Heisenberg antiferromagnet on two Archimedian lattices: From the bounce lattice to the maple-leaf lattice and beyond,"We investigate the ground state of the two-dimensional Heisenberg
+antiferromagnet on two Archimedean lattices, namely, the maple-leaf and bounce
+lattices as well as a generalized $J$-$J'$ model interpolating between both
+systems by varying $J'/J$ from $J'/J=0$ (bounce limit) to $J'/J=1$ (maple-leaf
+limit) and beyond. We use the coupled cluster method to high orders of
+approximation and also exact diagonalization of finite-sized lattices to
+discuss the ground-state magnetic long-range order based on data for the
+ground-state energy, the magnetic order parameter, the spin-spin correlation
+functions as well as the pitch angle between neighboring spins. Our results
+indicate that the ""pure"" bounce ($J'/J=0$) and maple-leaf ($J'/J=1$) Heisenberg
+antiferromagnets are magnetically ordered, however, with a sublattice
+magnetization drastically reduced by frustration and quantum fluctuations. We
+found that magnetic long-range order is present in a wide parameter range $0
+\le J'/J \lesssim J'_c/J $ and that the magnetic order parameter varies only
+weakly with $J'/J$. At $J'_c \approx 1.45 J$ a direct first-order transition to
+a quantum orthogonal-dimer singlet ground state without magnetic long-range
+order takes place. The orthogonal-dimer state is the exact ground state in this
+large-$J'$ regime, and so our model has similarities to the Shastry-Sutherland
+model. Finally, we use the exact diagonalization to investigate the
+magnetization curve. We a find a 1/3 magnetization plateau for $J'/J \gtrsim
+1.07$ and another one at 2/3 of saturation emerging only at large $J'/J \gtrsim
+3$.",1104.2572v1
+2012-12-06,Simulations of magnetic fields in isolated disk galaxies,"Magnetic fields are known to be dynamically important in the interstellar
+medium of our own Galaxy, and they are ubiquitously observed in diffuse gas in
+the halos of galaxies and galaxy clusters. Yet, magnetic fields have typically
+been neglected in studies of the formation of galaxies, leaving their global
+influence on galaxy formation largely unclear. We extend our MHD implementation
+in the moving-mesh code Arepo to cosmological problems which include radiative
+cooling and the formation of stars. In particular, we replace our previously
+employed divergence cleaning approach with a Powell 8-wave scheme, which turns
+out to be significantly more stable, even in very dynamic environments. We
+verify the improved accuracy through simulations of the MRI in accretion disks,
+that reproduce its correct linear growth rate. Using this new MHD code, we
+simulate the formation of isolated disk galaxies similar to the Milky Way using
+idealized initial conditions with and without magnetic fields. We find that the
+magnetic field is quickly amplified in the initial starburst and the
+differential rotation of the forming disk until it eventually saturates when it
+becomes comparable to the thermal pressure. The additional pressure component
+leads to a lower star formation rate at late times compared to simulations
+without magnetic fields, and induces changes in the spiral arm structures of
+the gas disk. In addition, we observe highly magnetized fountain-like outflows
+from the disk. These results are robust with numerical resolution and are
+largely independent of the initial magnetic seed field assumed in the initial
+conditions, as the amplification process is rapid and self-regulated. Our
+findings suggest an important influence of magnetic fields on galaxy formation
+and evolution, cautioning against their neglect in theoretical models of
+structure formation.",1212.1452v1
+2014-01-10,Investigation of the strongly correlated one-dimensional magnetic behavior of NiTa2O6,"The magnetic properties of NiTa$_2$O$_6$ were investigated by magnetic
+susceptibility, specific heat, electron paramagnetic resonance, neutron powder
+diffraction and pulse field magnetization measurements. Accompanying \textit{ab
+initio} DFT calculations of the spin-exchange constants complemented and
+supported our experimental findings that NiTa$_2$O$_6$ must be described as a
+quasi-1D Heisenberg $S$ = 1 spin chain system with a nearest-neighbor only
+anti-ferromagnetic spin-exchange interaction of 18.92(2) K. Inter-chain
+coupling is by about two orders of magnitude smaller. Electron paramagnetic
+resonance measurements on Mg$_{1-x}$Ni$_x$Ta$_2$O$_6$ ($x \approx$ $1\%$)
+polycrystalline samples enabled us to estimate the single-ion zero-field
+splitting of the $S$ = 1 states which amounts to less than $4\%$ of the
+nearest-neighbor spin-exchange interaction. At 0 T NiTa$_2$O$_6$ undergoes
+long-range anti-ferromagnetic ordering at 10.3(1) K evidenced by a
+$\lambda$-type anomaly in the specific heat capacity. On application of a
+magnetic field the specific heat anomaly is smeared out. We confirmed the
+magnetic structure by neutron powder diffraction measurements and at 2.00(1) K
+refined a magnetic moment of 1.93(5) $\mu_{\rm{B}}$ per Ni$^{2+}$ ion.
+Additionally, we followed the magnetic order parameter as a function of
+temperature. Lastly we found saturation of the magnetic moment at 55.5(5) T
+with a $g$-factor of 2.14(1), with an additional high field phase above 12.8(1)
+T. The onset of the new high field phase is not greatly effected by
+temperature, but rather smears out as one approaches the long-range ordering
+temperature.",1401.2401v1
+2015-02-11,Anisotropic defect-induced ferromagnetism and transport in Gd-doped GaN two-dimensional electron gasses,"Here we report on the effect of rare earth Gd-doping on the magnetic
+properties and magnetotransport of GaN two-dimensional electron gasses (2DEGs).
+Samples are grown by plasma-assisted molecular beam epitaxy and consist of
+AlN/GaN heterostructures where Gd is delta-doped within a polarization-induced
+2DEG. Ferromagnetism is observed in these Gd-doped 2DEGs with a Curie
+temperature above room temperature and an anisotropic spontaneous magnetization
+preferring an out-of-plane (c-axis) orientation. At magnetic fields up to 50
+kOe, the magnetization remains smaller for in-plane configuration than for
+out-of-plane, which is indicative of exchange coupled spins locked along the
+polar c-axis. The sample with the lowest Gd concentration (2.3 $\times$
+$10^{14}$ cm$^{-2}$) exhibits a saturation magnetization of 41.1
+$\mu_B/Gd^{3+}$ at 5 K revealing that the Gd ion spins (7 ${\mu}_B$) alone do
+not account for the magnetization. Surprisingly, control samples grown without
+any Gd display inconsistent magnetic properties; in some control samples weak
+ferromagnetism is observed and in others paramagnetism. The ferromagnetic 2DEGs
+do not exhibit the anomalous Hall effect; the Hall resistance varies
+non-linearly with the magnetic field, but does not track the magnetization
+indicating the lack of coupling between the ferromagnetic phase and the
+conduction band electrons within the 2DEG.",1502.03478v2
+2015-10-05,Absence of magnetic proximity effects in magnetoresistive Pt/CoFe2O4 hybrid interfaces,"Ultra-thin Pt films grown on insulating ferrimagnetic CoFe2O4 (111) epitaxial
+films display a magnetoresistance upon rotating the magnetization of the
+magnetic layer. We report here X-ray magnetic circular dichroism (XMCD)
+recorded at Pt-L2,3 and Pt-M3 edges. The results indicate that the Pt magnetic
+moment, if any, is below the detection limit (< 0.001 {\mu}$_B$/Pt), thus
+strongly favoring the view that the presence of CoFe2O4 does not induce the
+formation of magnetic moments in Pt. Therefore, the observed magnetoresistance
+cannot be attributed to some sort of proximity-induced magnetic moments at Pt
+ions and subsequent magnetic-field dependent scattering. It thus follows that
+either bulk (spin Hall and Inverse spin Hall Effects) or interface (Rashba)
+spin-orbit related effects dominate the observed magnetoresistance.
+Furthermore, comparison of bulk magnetization and XMCD data at (Fe,Co)-L2,3
+edges suggests the presence of some spin disorder in the CoFe2O4 layer which
+may be relevant for the observed anomalous non-saturating field-dependence of
+spin Hall magnetoresistance.",1510.01080v4
+2015-12-14,The magnetic shear-current effect: generation of large-scale magnetic fields by the small-scale dynamo,"A novel large-scale dynamo mechanism, the magnetic shear-current effect, is
+discussed and explored. The effect relies on the interaction of magnetic
+fluctuations with a mean shear flow, meaning the saturated state of the
+small-scale dynamo can drive a large-scale dynamo -- in some sense the inverse
+of dynamo quenching. The dynamo is nonhelical, with the mean-field $\alpha$
+coefficient zero, and is caused by the interaction between an off-diagonal
+component of the turbulent resistivity and the stretching of the large-scale
+field by shear flow. Following up on previous numerical and analytic work, this
+paper presents further details of the numerical evidence for the effect, as
+well as an heuristic description of how magnetic fluctuations can interact with
+shear flow to produce the required electromotive force. The pressure response
+of the fluid is fundamental to this mechanism, which helps explain why the
+magnetic effect is stronger than its kinematic cousin, and the basic idea is
+related to the well-known lack of turbulent resistivity quenching by magnetic
+fluctuations. As well as being interesting for its applications to general high
+Reynolds number astrophysical turbulence, where strong small-scale magnetic
+fluctuations are expected to be prevalent, the magnetic shear-current effect is
+a likely candidate for large-scale dynamo in the unstratified regions of
+ionized accretion disks. Evidence for this is discussed, as well as future
+research directions and the challenges involved with understanding details of
+the effect in astrophysically relevant regimes.",1512.04511v2
+2016-12-17,Magnetic resonance study of bulk and thin film EuTiO3,"Magnetic resonance spectra of EuTiO3 in both bulk and thin film form were
+taken at temperatures from 3-350 K and microwave frequencies from 9.2-9.8 and
+34 GHz. In the paramagnetic phase, magnetic resonance spectra are determined by
+magnetic dipole and exchange interactions between Eu2+ spins. In the film, a
+large contribution arises from the demagnetization field. From detailed
+analysis of the linewidth and its temperature dependence, the parameters of
+spin-spin interactions were determined: the exchange frequency is 15-15.5 GHz
+and the estimated critical exponent of the spin correlation length is ~ 0.5. In
+the bulk samples, the spectra exhibited a distinct minimum in the linewidth at
+the N\'eel temperature, T_N = 5.5 K, while the resonance field practically does
+not change even on cooling below T_N. This is indicative of a small magnetic
+anisotropy ~ 320 G in the antiferromagnetic phase. In the film, the magnetic
+resonance spectrum is split below T_N into several components due to excitation
+of the magnetostatic modes, corresponding to a non-uniform precession of
+magnetization. Moreover, the film was observed to degrade over two years. This
+was manifested by an increase of defects and a change in the domain structure.
+The saturated magnetization in the film, estimated from the magnetic resonance
+spectrum, was about 900 emu/cm3 or 5.5 mu_B/unit cell at T = 3.5 K.",1612.05781v1
+2017-03-24,Electronic structure and direct observation of ferrimagnetism in multiferroic hexagonal YbFeO3,"The magnetic interaction between rare-earth and Fe ions in hexagonal
+rare-earth ferrites (h-REFeO3), may amplify the weak ferromagnetic moment on
+Fe, making these materials more appealing as multiferroics. To elucidate the
+interaction strength between the rare-earth and Fe ions as well as the magnetic
+moment of the rare-earth ions, element specific magnetic characterization is
+needed. Using X-ray magnetic circular dichroism, we have studied the
+ferrimagnetism in h-YbFeO3 by measuring the magnetization of Fe and Yb
+separately. The results directly show anti-alignment of magnetization of Yb and
+Fe ions in h-YbFeO3 at low temperature, with an exchange field on Yb of about
+17 kOe. The magnetic moment of Yb is about 1.6 \muB at low-temperature,
+significantly reduced compared with the 4.5 \muB moment of a free Yb3+. In
+addition, the saturation magnetization of Fe in h-YbFeO3 has a sizable
+enhancement compared with that in h-LuFeO3. These findings directly demonstrate
+that ferrimagnetic order exists in h-YbFeO3; they also account for the
+enhancement of magnetization and the reduction of coercivity in h-YbFeO3
+compared with those in h-LuFeO3 at low temperature, suggesting an important
+role for the rare-earth ions in tuning the multiferroic properties of h-REFeO3.",1703.08482v2
+2017-06-09,Negative spin Hall magnetoresistance of Pt on the bulk easy-plane antiferromagnet NiO,"We report on spin Hall magnetoresistance (SMR) measurements of Pt Hall bars
+on the antiferromagnetic NiO(111) single crystal. An SMR with a sign opposite
+of conventional SMR is observed over a wide range of temperatures as well as
+magnetic fields stronger than 0.25T. The negative sign of the SMR can be
+explained by the alignment of magnetic moments being almost perpendicular to
+the external magnetic field within the easy plane (111) of the antiferromagnet.
+This correlation of magnetic moment alignment and external magnetic field
+direction is realized just by the easy-plane nature of the material without the
+need of any exchange coupling to an additional ferromagnet. The SMR signal
+strength decreases with increasing temperature, primarily due to the decrease
+in N\'eel order by including fluctuations. An increasing magnetic field
+increases the SMR signal strength as there are less domains and the magnetic
+moments are more strongly manipulated at high magnetic fields. The SMR is
+saturated at an applied magnetic field of $6$~T resulting in a spin-mixing
+conductance of $\sim10^{18}~ \Omega^{-1}$m$^{-2}$, which is comparable to that
+of Pt on insulating ferrimagnets such as yttrium iron garnet. An argon plasma
+treatment doubles the spin-mixing conductance.",1706.03004v1
+2018-10-07,Spin dynamics and field-induced magnetic phase transition in the honeycomb Kitaev magnet $α$-Li$_2$IrO$_3$,"The layered honeycomb iridate $\alpha$-Li$_2$IrO$_3$ displays an
+incommensurate magnetic structure with counterrotating moments on
+nearest-neighbor sites, proposed to be stabilized by strongly-frustrated
+anisotropic Kitaev interactions between spin-orbit entangled Ir$^{4+}$ magnetic
+moments. Here we report powder inelastic neutron scattering measurements that
+observe sharply dispersive low-energy magnetic excitations centered at the
+magnetic ordering wavevector, attributed to Goldstone excitations of the
+incommensurate order, as well as an additional intense mode above a gap
+$\Delta\simeq2.3$ meV. Zero-field muon-spin relaxation measurements show clear
+oscillations in the muon polarization below the N\'{e}el temperature $T_{\rm
+N}\simeq15$ K with a time-dependent profile consistent with bulk incommensurate
+long-range magnetism. Pulsed field magnetization measurements observe that only
+about half the saturation magnetization value is reached at the maximum field
+of 64 T. A clear anomaly near 25 T indicates a transition to a phase with
+reduced susceptibility. The transition field has a Zeeman energy comparable to
+the zero-field gapped mode, suggesting gap suppression as a possible mechanism
+for the field-induced transition.",1810.03212v1
+2019-02-14,Calculating temperature-dependent properties of Nd$_2$Fe$_{14}$B permanent magnets by atomistic spin model simulations,"Temperature-dependent magnetic properties of Nd$_2$Fe$_{14}$B permanent
+magnets, i.e., saturation magnetization $M_\text{s}(T)$, effective magnetic
+anisotropy constants $K_i^\text{eff}(T)$ ($i=1,2,3$), domain wall width
+$\delta_w(T)$, and exchange stiffness constant $A_\text{e}(T)$, are calculated
+by using \textit{ab-initio} informed atomistic spin model simulations. We
+construct the atomistic spin model Hamiltonian for Nd$_2$Fe$_{14}$B by using
+the Heisenberg exchange of Fe$-$Fe and Fe$-$Nd atomic pairs, the uniaxial
+single-ion anisotropy of Fe atoms, and the crystal-field energy of Nd ions
+which is approximately expanded into an energy formula featured by second,
+fourth, and sixth-order phenomenological anisotropy constants. After applying a
+temperature rescaling strategy, we show that the calculated Curie temperature,
+spin-reorientation phenomenon, $M_\text{s}(T)$, $\delta_w(T)$, and
+$K_i^\text{eff}(T)$ agree well with the experimental results. $A_\text{e}(T)$
+is estimated through a general continuum description of the domain wall profile
+by mapping atomistic magnetic moments to the macroscopic magnetization.
+$A_\text{e}$ is found to decrease more slowly than $K_1^\text{eff}$ with
+increasing temperature, and approximately scale with normalized magnetization
+as $A_\text{e}(T) \sim m^{1.2}$. This work provokes a scale bridge between
+\textit{ab-initio} calculations and temperature-dependent micromagnetic
+simulations of Nd-Fe-B permanent magnets.",1902.05636v2
+2019-04-08,Magnetism study on a triangular lattice antiferromagnet Cu$_2$(OH)$_3$Br,"Magnetism of Cu$_2$(OH)$_3$Br single crystals based on a triangular lattice
+is studied by means of magnetic susceptibility, pulsed-field magnetization, and
+specific heat measurements. There are two inequivalent Cu$^{2+}$ sites in an
+asymmetric unit. Both Cu$^{2+}$ sublattices undergo a long-range
+antiferromagnetic (AFM) order at $T\rm_N$ = 9.3 K. Upon cooling, an anisotropy
+crossover from Heisenberg to $XY$ behavior is observed below 7.5 K from the
+anisotropic magnetic susceptibility. The magnetic field applied within the $XY$
+plane induces a spin-flop transition of Cu$^{2+}$ ions between 4.9 T and 5.3 T.
+With further increasing fields, the magnetic moment is gradually increased but
+is only about half of the saturation of a Cu$^{2+}$ ion even in 30 T. The
+individual reorientation of the inequivalent Cu$^{2+}$ spins under field is
+proposed to account for the magnetization behavior. The observed spin-flop
+transition is likely related to one Cu site, and the AFM coupling among the
+rest Cu spins is so strong that the 30-T field cannot overcome the anisotropy.
+The temperature dependence of the magnetic specific heat, which is well
+described by a sum of two gapped AFM contributions, is a further support for
+the proposed scenario.",1904.03798v1
+2019-05-09,Domain wall pinning and hard magnetic phase in Co-doped bulk single crystalline Fe3GeTe2,"We report the effects of cobalt doping on the magnetic properties of
+two-dimensional van der Waals ferromagnet Fe3GeTe2. Single crystals of
+(Fe{1-x}Cox)3GeTe2 with x=0-0.78 were successfully synthesized and
+characterized with x-ray diffraction, energy dispersive x-ray spectroscopy and
+magnetization measurements. Both the Curie-Weiss temperature and ferromagnetic
+(FM) ordered moment of Fe3GeTe2 are gradually suppressed upon Co doping. A kink
+in zero-field-cooling low field M(T) curve which is previously explained as an
+antiferromagnetic transition is observed for samples with x=0-0.58. Our
+detailed magnetization measurements and theoretical calculations strongly
+suggest that this kink is originated from the pinning of magnetic domain walls.
+The domain pinning effects are suddenly enhanced when the doping concentration
+of cobalt is around 50%, both the coercive field Hc and the magnetic remanence
+to saturated magnetization ratio MR/MS are largely improved and a hard magnetic
+phase emerges in bulk single crystal samples. The strong doping dependent
+magnetic properties suggest more spintronic applications of Fe3GeTe2.",1905.03458v1
+2019-11-27,Field-induced magnetic transition and spin fluctuation in quantum spin liquid candidate CsYbSe$_2$,"Two-dimensional triangular-lattice materials with spin-1/2 are perfect
+platforms for investigating quantum frustrated physics with spin fluctuations.
+Here we report the structure, magnetization, heat capacity and inelastic
+neutron scattering (INS) results on cesium ytterbium diselenide, CsYbSe$_2$.
+There is no long-range magnetic order down to 0.4 K at zero field. The
+temperature dependent magnetization, $M(T)$, reveals an easy-plane magnetic
+anisotropy. A maximum is found in $M(T)$ around \emph{T}$\sim$1.5 K when
+magnetic field $H$ is applied in the $ab$ plane, indicating the short-range
+interaction. The low-temperature isothermal magnetization $M(H)$ shows a
+one-third plateau of the estimated saturation moment, that is characteristic of
+a two-dimensional frustrated triangular lattice. Heat capacity shows
+field-induced long-range magnetic order for both $H||c$ and $H||ab$ directions.
+The broad peak in heat capacity and highly damped INS magnetic excitation at
+$T$=2 K suggests strong spin fluctuations. The dispersive in-plane INS,
+centered at the (1/3 1/3 0) point, and the absence of dispersion along $c$
+direction suggests 120$^{\circ}$ non-collinear 2D-like spin correlations. All
+these results indicate that the two-dimensional frustrated material CsYbSe$_2$
+can be in proximity to the triangular-lattice quantum spin liquid. We propose
+an experimental low-temperature $H$-$T$ phase diagram for CsYbSe$_2$.",1911.12286v1
+2020-05-01,Tunable Ferromagnetism and Thermally Induced Spin Flip in Vanadium-doped Tungsten Diselenide Monolayers at Room Temperature,"The outstanding optoelectronic and valleytronic properties of transition
+metal dichalcogenides (TMDs) have triggered intense research efforts by the
+scientific community. An alternative to induce long-range ferromagnetism (FM)
+in TMDs is by introducing magnetic dopants to form a dilute magnetic
+semiconductor. Enhancing ferromagnetism in these semiconductors not only
+represents a key step towards modern TMD-based spintronics, but also enables
+exploration of new and exciting dimensionality-driven magnetic phenomena. To
+this end, we show tunable ferromagnetism at room temperature and a thermally
+induced spin flip (TISF) in monolayers of V-doped WSe2. As vanadium
+concentrations increase within the WSe2 monolayers the saturation magnetization
+increases, and it is optimal at ~4at.% vanadium; the highest doping/alloying
+level ever achieved for V-doped WSe2 monolayers. The TISF occurs at ~175 K and
+becomes more pronounced upon increasing the temperature towards room
+temperature. We demonstrate that TISF can be manipulated by changing the
+vanadium concentration within the WSe2 monolayers. We attribute TISF to the
+magnetic field and temperature dependent flipping of the nearest W-site
+magnetic moments that are antiferromagnetically coupled to the V magnetic
+moments in the ground state. This is fully supported by a recent spin-polarized
+density functional theory calculation. Our findings pave the way for the
+development of novel spintronic and valleytronic nanodevices based on
+atomically thin magnetic semiconductors and stimulate further studies in this
+rapidly expanding research field of 2D magnetism.",2005.00493v1
+2020-10-07,Correlation of uniaxial magnetic anisotropy axes and principal resistivities in polycrystalline ferromagnetic films,"In the present study, we demonstrate the measurement of resistivity tensor
+($\rho$) along the magnetic axes of a polycrystalline film of ferromagnetic
+permalloy (Py). To this end, conventional Hall-bar and a more recent extended
+van der Pauw methods were utilized for determining 2D $\rho$ in the film plane.
+The samples were prepared by normal incidence sputter deposition within an
+in-situ magnetic field to induce in-plane uniaxial magnetic anisotropy in the
+film. Since $\rho$ might be affected by the internal magnetization of the film,
+we performed measurements by rotation of a saturating magnetic field in the
+film plane. Both methods indicate that the average resistivity is lower along
+the easy axis of the film compared to the hard axis. Since X-ray diffraction
+results indicated no dominating texture in the film, we concluded that there is
+a correlation between uniaxial magnetic axes and principal resistivity axes.
+This is an important finding that allows determining the direction of magnetic
+anisotropy axes without magnetometry. The results also verify atomic or pair
+ordering to be the origin of uniaxial magnetic anisotropy in the Py since
+resistivity is sensitive to the level of order in solids. The extended van der
+Pauw utilized here can be easily performed on the as-received samples which is
+of practical interest.",2010.03554v3
+2020-12-31,Neutron diffraction study of magnetism in van der Waals layered MnBi$_{2n}$Te$_{3n+1}$,"Two-dimensional van der Waals MnBi$_{2n}$Te$_{3n+1}$ (n = 1, 2, 3, 4)
+compounds have been recently found to be intrinsic magnetic topological
+insulators rendering quantum anomalous Hall effect and diverse topological
+states. Here, we summarize and compare the crystal and magnetic structures of
+this family, and discuss the effects of chemical composition on their
+magnetism. We found that a considerable fraction of Bi occupies at the Mn sites
+in MnBi$_{2n}$Te$_{3n+1}$ (n = 1, 2, 3, 4) while Mn is no detectable at the
+non-magnetic atomic sites within the resolution of neutron diffraction
+experiments. The occupancy of Mn monotonically decreases with the increase of
+n. The polarized neutron diffraction on the representative MnBi$_{4}$Te$_{7}$
+reveals that its magnetization density is exclusively accumulated at the Mn
+site, in good agreement with the results from the unpolarized neutron
+diffraction. The defects of Bi at the Mn site naturally explain the
+continuously reduced saturated magnetic moments from n = 1 to n = 4. The
+experimentally estimated critical exponents of all the compounds generally
+suggest a three-dimensional character of magnetism. Our work provides
+material-specified structural parameters that may be useful for band structure
+calculations to understand the observed topological surface states and for
+designing quantum magnetic materials through chemical doping.",2012.15415v2
+2021-02-22,"Structural, magnetic, and magnetocaloric properties of Fe2CoAl Heusler nanoalloy","Spherical nanoparticles (NPs) of size 14 nm, made of intermetallic Fe2CoAl
+(FCA) Heusler alloy, are synthesized via the co-precipitation and thermal
+deoxidization method. X-ray diffraction (XRD) and selected area electron
+diffraction (SAED) patterns confirm that the present nanoalloy is crystallized
+in A2-disordered cubic Heusler structure. Magnetic field (H) and temperature
+(T) dependent magnetization (M) results reveal that the NPs are soft
+ferromagnetic (FM) with high saturation magnetization (Ms) and Curie
+temperature (Tc). Fe2CoAl nanoalloy does not follow the Slater Pauling (SP)
+rule, possibly because of the disorder present in the system. We also
+investigate its magnetic phase transition (MPT) and magnetocaloric (MC)
+properties. The peak value of the magnetic entropy change vs T curve at a
+magnetic field change of 20 kOe corresponds to about 2.65 J/kg-K, and the
+observed value of refrigeration capacity (RCP) is as large as 44 J/kg,
+suggesting a large heat conversion in magnetic refrigeration cycle. The Arrott
+plot and the nature of the universal curve accomplish that the FM to
+paramagnetic (PM) phase transition in Fe2CoAl nanoalloy is of second-order. The
+present study suggests that the Fe2CoAl nanoscale system is proficient, useful
+and a good candidate for the spintronics application and opens up a window for
+further research on full-Heusler based magnetic refrigerants.",2102.11195v2
+2021-04-14,"On the complexity of spinels: Magnetic, electronic, and polar ground states","This review summarizes more than 100 years of research on spinel compounds,
+mainly focusing on the progress in understanding their magnetic, electronic,
+and polar properties during the last two decades. Many spinel compounds are
+magnetic insulators or semiconductors; however, a number of spinel-type metals
+exists including superconductors and some rare examples of d-derived
+heavy-fermion compounds. In the early days, they gained importance as
+ferrimagnetic or even ferromagnetic insulators with relatively high saturation
+magnetization and high ordering temperatures, with magnetite being the first
+magnetic mineral known to mankind. However, spinels played an outstanding role
+in the development of concepts of magnetism, in testing and verifying the
+fundamentals of magnetic exchange, in understanding orbital-ordering and
+charge-ordering phenomena. In addition, the A- site as well as the B-site
+cations in the spinel structure form lattices prone to strong frustration
+effects resulting in exotic ground-state properties. In case the A-site cation
+is Jahn-Teller active, additional entanglements of spin and orbital degrees of
+freedom appear, which can give rise to a spin-orbital liquid or an orbital
+glass state. The B-site cations form a pyrochlore lattice, one of the strongest
+contenders of frustration in three dimensions. In addition, in spinels with
+both cation lattices carrying magnetic moments, competing magnetic exchange
+interactions become important, yielding ground states like the time-honoured
+triangular Yafet-Kittel structure. Finally, yet importantly, there exists a
+long-standing dispute about the possibility of a polar ground state in spinels,
+despite their reported overall cubic symmetry. Indeed, over the years number of
+multiferroic spinels were identified.",2104.06889v1
+2021-05-29,Magnetic Field and Frequency Dependent AC Susceptibility of High-Tc YBCO Single Crystal,"The temperature dependence of AC susceptibility (ACS) has been measured for a
+very high-quality plate-like slightly overdoped YBCO single crystal for
+different frequencies and AC magnetic field amplitudes. Frequency dependence of
+the ACS is weak irrespective of the magnetic field orientation but significant
+effects of field orientation with respect to the CuO2 planes and field
+magnitude on real and imaginary components of fundamental ACS were observed.
+The height of the loss peak saturates as full penetration of magnetic field is
+achieved. The peak temperature, Tp, in \c{hi}"" shifts to lower temperatures
+with increasing magnetic field amplitude for both HIIc and HIIab. The value of
+Tp depends on the orientation of the magnetic field with respect to the
+crystallographic axes, illustrating the anisotropy in the magnetic flux
+dynamics. The superconducting transition width increases weakly with increasing
+magnetic field. The Cole-Cole plot [\c{hi}""(\c{hi}')] shows qualitatively and
+quantitatively identical features for HIIc and HIIab, independent of the
+orientation of the magnetic field with respect to the sample geometry and
+shielding current paths. The general features of \c{hi}""(\c{hi}') implies that,
+there is no flux creep for the range of frequencies and AC fields employed in
+this investigation. The maximum value of the loss peak and its position with
+respect to \c{hi}' in the Cole-Cole plot are largely consistent with the Bean
+critical state model. Slightly increased peak value in comparison to the
+predicted peak value within the Bean critical state model is probably due to a
+weak field dependence of Jc. The results obtained here are compared with
+various theoretical models and experimental findings. Prominent differences are
+noted and discussed in details in this study.",2105.14321v1
+2021-06-27,Relaxation in Ordered Assembly of Magnetic Nanoparticles,"We study the relaxation characteristics in the two-dimensional ($l^{}_x
+\times l^{}_y$) array of magnetic nanoparticles (MNPs) as a function of aspect
+ratio $A^{}_r=l^{}_y/l^{}_x$, dipolar interaction strength $h^{}_d$ and
+anisotropy axis orientation using computer simulation. The anisotropy axes of
+all the MNPs are assumed to have the same direction, $\alpha$ being the
+orientational angle. Irrespective of $\alpha$ and $A^{}_r$, the functional form
+of the magnetization-decay curve is perfectly exponentially decaying with
+$h^{}_d\leq0.2$. There exists a transition in relaxation behaviour at
+$h^{}_d\approx0.4$; magnetization relaxes slowly for $\alpha\leq45^\circ$; it
+relaxes rapildy with $\alpha>45^\circ$. Interestingly, it decays rapidly for
+$h^{}_d>0.6$, irrespective of $\alpha$. It is because the dipolar interaction
+promotes antiferromagnetic coupling in such cases. There is a strong effect of
+$\alpha$ on the magnetic relaxation in the highly anisotropic system
+($A^{}_r\geq25$). Interesting physics unfolds in the case of a huge aspect
+ratio $A^{}_r=400$. There is a rapid decay of magnetization with $\alpha$, even
+for weakly interacting MNPs. Remarkably, magnetization does not relax even with
+a moderate value of $h^{}_d=0.4$ and $\alpha=0^\circ$ because of ferromagnetic
+coupling dominance. Surprisingly, there is a complete magnetization reversal
+from saturation (+1) to $-1$ state with $\alpha>60^\circ$. The dipolar field
+and anisotropy axis tend to get aligned antiparallel to each other in such a
+case. The effective N\'eel relaxation time $\tau^{}_N$ depends weakly on
+$\alpha$ for small $h^{}_d$ and $A^{}_r\leq25.0$. For large $A^{}_r$, there is
+a rapid fall in $\tau^{}_N$ as $\alpha$ is incremented from 0 to $90^\circ$.
+These results benefit applications in data and energy storages where such
+controlled magnetization alignment and desired structural anisotropy are
+desirable.",2106.14271v1
+2022-01-25,Collinear antiferromagnetic order in spin-$\frac52$ triangle lattice antiferromagnet Na$_3$Fe(PO$_4$)$_2$,"We set forth the structural and magnetic properties of the frustrated
+spin-$5/2$ triangle lattice antiferromagnet Na$_3$Fe(PO$_4$)$_2$ examined via
+x-ray diffraction, magnetization, heat capacity, and neutron diffraction
+measurements on the polycrystalline sample. No structural distortion was
+detected from the temperature-dependant x-ray diffraction down to 12.5 K,
+except a systematic lattice contraction. The magnetic susceptibility at high
+temperatures agrees well with the high-temperature series expansion for a
+spin-$5/2$ isotropic triangular lattice antiferromagnet with an average
+exchange coupling of $J/k_{\rm B} \simeq 1.8$ K rather than a one-dimensional
+spin-$5/2$ chain model. This value of the exchange coupling is consistently
+reproduced by the saturation field of the pulse field magnetization data. It
+undergoes a magnetic long-range-order at $T_{\rm N} \simeq 10.4$ K. Neutron
+diffraction experiments elucidate a collinear antiferromagnetic ordering below
+$T_{\rm N}$ with the propagation vector $k = (1,0,0)$. An intermediate value of
+frustration ratio ($f \simeq 3.6$) reflects moderate frustration in the
+compound which is corroborated by a reduced ordered magnetic moment of $\sim
+1.52$ $\mu_{\rm B}$ at 1.6 K, compared to its classical value ($5 \mu_{\rm
+B}$). Magnetic isotherms exhibit a change of slope envisaging a field induced
+spin-flop transition at $H_{\rm SF}\simeq3.2$ T. The magnetic field vs
+temperature phase diagram clearly unfold three distinct phase regimes,
+reminiscent of a frustrated magnet with in-plane (XY-type) anisotropy.",2201.10467v1
+2023-02-01,Temperature-independent ferromagnetic resonance shift in Bi-doped YIG garnets through magnetic anisotropy tuning,"Thin garnet films are becoming central for magnon-spintronics and
+spin-orbitronics devices as they show versatile magnetic properties together
+with low magnetic losses. These fields would benefit from materials in which
+heat does not affect the magnetization dynamics, an effect known as the
+non-linear thermal frequency shift. In this study, low damping Bi substituted
+Iron garnet (Bi:YIG) ultra-thin films have been grown using Pulsed Laser
+Deposition. Through a fine tuning of the growth parameters, the precise control
+of the perpendicular magnetic anisotropy allows to achieve a full compensation
+of the dipolar magnetic anisotropy. Strikingly, once the growth conditions are
+optimized, varying the growth temperature from 405 {\deg}C to 475 {\deg}C as
+the only tuning parameter induces the easy-axis to go from out-of-plane to
+in-plane. For films that are close to the dipolar compensation, Ferromagnetic
+Resonance measurements yield an effective magnetization $\mu _{0}M_{eff} (T)$
+that has almost no temperature dependence over a large temperature range (260 K
+to 400 K) resulting in an anisotropy temperature exponent of 2. These findings
+put Bi:YIG system among the very few materials in which the temperature
+dependence of the magnetic anisotropy varies at the same rate than the
+saturation magnetization. This interesting behavior is ascribed
+phenomenologically to the sizable orbital moment of $Bi^{3+}$.",2302.00585v1
+2023-02-23,First-principles based Monte Carlo modeling of oxygen deficient Fe-substituted SrTiO$_3$ experimental magnetization,"Ferroics based on transition-metal (TM) substituted SrTiO$_{3}$ have called
+much attention as magnetism and/or ferroelectricity can be tuned by using
+cations substitution and defects, strain and/or oxygen deficiency. C. A. Ross
+et al. [Phys. Rev. Applied 7, 024006 (2017)] demonstrated the
+SrTi$_{1-x}$Fe$_{x}$O$_{3-\delta}$ (STF) magnetization behavior for different
+deposition oxygen-pressures, substrates and magnetic fields. The relation
+between oxygen deficiency and ferroic orders is yet to be well understood, for
+which the full potential of oxygen-stoichiometry engineered materials remain an
+open question. Here, we use hybrid-DFT to calculate different oxygen vacancy
+($v_{o}$) states in STF with a variety of TM distributions. The resulting
+cations' magnetic states and alignments associated to the $v_{o}$ ground-states
+for $x=\{0.125,0.25\}$ are used within a Monte Carlo scope for collinear
+magnetism to simulate the spontaneous magnetization. Our model captures several
+experimental STF features i.e., display a maximum of the magnetization at
+intermediate number of vacancies, a monotonous quenching from
+$\sim{0.35}\mu{_{B}}$ for small ${\delta}$, and a slower decreasing of such
+saturation for larger number of vacancies. Moreover, our approach gives a
+further insight into the relations between defects stabilization and
+magnetization, vacancy density and the oxygen pressure required to maximize
+such ferroic order, and sets guidelines for future Machine Learning based
+computational synthesis of multiferroic oxides.",2302.12174v1
+2023-04-16,Anomalous and Topological Hall Resistivity in Ta/CoFeB/MgO Magnetic Systems for Neuromorphic Computing Applications,"Topologically protected spin textures, such as magnetic skyrmions, have the
+potential for dense data storage as well as energy-efficient computing due to
+their small size and a low driving current. The evaluation of the writing and
+reading of the skyrmion's magnetic and electrical characteristics is a key step
+toward the implementation of these devices. In this paper, we present the
+magnetic heterostructure Hall bar device and study the anomalous Hall and
+topological Hall signals in the device. Using the combination of different
+measurements like magnetometry at different temperatures, Hall effect
+measurement from 2K to 300K, and magnetic force microscopy imaging, we
+investigate the magnetic and electrical characteristics of the magnetic
+structure. We measure the skyrmion topological resistivity at different
+temperatures as a function of the magnetic field. The topological resistivity
+is maximum around the zero magnetic field and it decreases to zero at the
+saturating field. This is further supported by MFM imaging. Interestingly the
+resistivity decreases linearly with the field, matching the behavior observed
+in the corresponding micromagnetic simulations. We combine the experimental
+results with micromagnetic simulations, thus propose a skyrmion-based synaptic
+device and show spin-orbit torque-controlled potentiation/depression in the
+device. The device performance as the synapse for neuromorphic computing is
+further evaluated in a convolutional neural network CNN. The neural network is
+trained and tested on the MNIST data set we show devices acting as synapses
+achieving a recognition accuracy close to 90%, on par with the ideal
+software-based weights which offer an accuracy of 92%.",2304.07742v1
+2023-08-09,1/3 plateau and 3/5 discontinuity in the magnetization and the magnetic phase diagram of hexagonal GdInO$_3$,"We report the high-pressure optical floating-zone growth of GdInO$_3$ single
+crystals and show its magnetic phase diagram down to the mK-regime as
+determined by magnetization measurements. The centered-honeycomb lattice
+structure shows considerable magnetic frustration ($\lvert\Theta\rvert /T_{\rm
+N}\simeq 5$) and develops long-range magnetic order below $T_{\rm N}$~=~2.1 K
+from a short-range ordered paramagnetic phase. Concomitantly, a small net
+magnetic moment evolves at $T_{\rm N}$ which points along the crystallographic
+$c$ direction. Upon cooling, the net moment reorients at $T^{**}\simeq 1.7$ K
+and $T^{*}\simeq 1$ K. A broad 1/3 plateau indicative of the up-up-down ($uud$)
+spin configuration appears for $B||c$ but is absent for $B||ab$, thereby
+suggesting easy axis anisotropy. At $T=0.4$ K, a jump in magnetization at
+$\simeq 3/5$ of the saturation magnetization signals a discontinuous transition
+to a high field phase and we find evidence for a possible tricritical point.
+Small energy and field scales in the accessible regimes render GdInO$_3$ a
+prime example to study the phase diagram of a semiclassical frustrated
+hexagonal lattice in the presence of weak easy axis anisotropy of mainly
+dipolar origin.",2308.04935v1
+2012-09-24,The evolution of the f-mode instability in neutron stars and gravitational wave detectability,"We study the dynamical evolution of the gravitational-wave driven instability
+of the f-mode in rapidly rotating relativistic stars. With an approach based on
+linear perturbation theory we describe the evolution of the mode amplitude and
+follow the trajectory of a newborn neutron star through its instability window.
+The influence on the f-mode instability of the magnetic field and the presence
+of an unstable r-mode is also considered. Two different configurations are
+studied in more detail; an N = 1 polytrope with a typical mass and radius and a
+more massive polytropic N = 0.62 model with gravitational mass M = 1.98 Msun.
+We study several evolutions with different initial rotation rates and
+temperature and determine the gravitational waves radiated during the
+instability. In more massive models, an unstable f-mode with a saturation
+energy of about 1e-6 Msun c^2 may generate a gravitational-wave signal which
+can be detected by the Advanced LIGO/Virgo detector from the Virgo cluster. The
+magnetic field affects the evolution and then the detectability of the
+gravitational radiation when its strength is higher than 1e12 G, while the
+effects of an unstable r-mode become dominant when this mode reaches the
+maximum saturation value allowed by non-linear mode couplings. However, the
+relative saturation amplitude of the f- and r-modes must be known more
+accurately in order to provide a definitive answer to this issue. From the
+thermal evolution we find also that the heat generated by shear viscosity
+during the saturation phase completely balances the neutrinos' cooling and
+prevents the star from entering the regime of mutual friction. The evolution
+time of the instability is therefore longer and the star loses significantly
+larger amounts of angular momentum via gravitational waves.",1209.5308v2
+2013-03-07,Saturation of the MRI in Strongly Radiation Dominated Accretion Disks,"The saturation level of the magneto-rotational instability (MRI) in a
+strongly radiation dominated accretion disk is studied using a new Godunov
+radiation MHD code in the unstratified shearing box approximation. Since
+vertical gravity is neglected in this work, our focus is on how the MRI
+saturates in the optically thick mid-plane of the disk. We confirm that
+turbulence generated by the MRI is very compressible in the radiation dominated
+regime, as found by previous calculations using the flux-limited diffusion
+approximation. We also find little difference in the saturation properties in
+calculations that use a larger horizontal domain (up to four times the vertical
+scale height in the radial direction). However, in strongly radiation pressure
+dominated disks (one in which the radiation energy density reaches 1% of the
+rest mass energy density of the gas), we find Maxwell stress from the MRI
+turbulence is larger than the value produced when radiation pressure is
+replaced with the same amount of gas pressure. At the same time, the ratio
+between Maxwell stress and Reynolds stress is increased by almost a factor of 8
+compared with the gas pressure dominated case. We suggest that this effect is
+caused by radiation drag, which acts like bulk viscosity and changes the
+effective magnetic Prandtl number of the fluid. Radiation viscosity
+significantly exceeds both the microscopic plasma viscosity and resistivity,
+ensuring that radiation dominated systems occupy the high magnetic Prandtl
+number regime. Nevertheless, we find radiative shear viscosity is negligible
+compared to the Maxwell and Reynolds stress in the flow. This may have
+important implications for the structure of radiation dominated accretion
+disks.",1303.1823v1
+2022-03-09,Modelling of saturated external MHD instabilities in tokamaks: a comparison of 3D free boundary equilibria and nonlinear stability calculations,"3D free boundary equilibrium computations have recently been used to model
+external kinks and edge harmonic oscillations (EHOs), comparing with linear MHD
+stability codes, and nonlinear analytic theory [Kleiner et al, PPCF 61 084005
+(2019)]. In this study, results of the VMEC equilibrium code are compared
+further with nonlinear reduced MHD simulations, using the JOREK code. The
+purpose of this investigation is to understand the extent to which the
+modelling approaches agree, and identify the important physical effects which
+can modify the dynamics. For the simulated external kink, which is dominated by
+a single toroidal harmonic, good agreement is found when a large Lundquist
+number is used in the JOREK simulation, such that resistive effects are
+sub-dominant. Modelling EHOs where multiple toroidal harmonics are linearly
+unstable, the saturated perturbation observed can differ in the dominant
+toroidal harmonic. On the ideal timescale, a n=2 EHO is observed in JOREK,
+while the saturated perturbation predicted by VMEC is a n=1 mode. Extending
+simulations into timescales where resistive effects can play a role, similar
+n=1 perturbations can be found. The coupling of different linearly unstable
+toroidal harmonics in the JOREK simulation broadens the magnetic energy
+spectrum and ergodises the plasma edge region, resulting in a more localised
+pressure perturbation. These effects are not observed in VMEC, because closed
+magnetic flux surfaces are enforced. Despite the sensitivity of JOREK results
+on the assumed resistivity, saturated states can be found using both approaches
+that are in reasonable agreement, even for this more advanced case.",2203.04772v2
+2005-10-18,"Domain imaging, MOKE and magnetoresistance studies of CoFeB films for MRAM applications","We present a detailed study on domain imaging, Kerr effect magnetometry
+(MOKE) and magnetoresistance (MR), for a series of 20 nm
+Co$_{73.8}$Fe$_{16.2}$B$_{10}$ thin films, both as-deposited (amorphous) and
+annealed (crystalline). By considering the two different (orthogonal) in-plane
+magnetization components, obtained by MOKE measurements, we were able to study
+the uniaxial anisotropy induced during CoFeB-deposition and to discriminate the
+magnetization processes under a magnetic field parallel and perpendicular to
+such axis. MOKE magnetic imaging enabled us to observe the dominant
+magnetization processes, namely domain wall motion and moment rotation. These
+processes were correlated with the behavior of the magnetoresistance, which
+depends both on short-range spin disorder electron scattering and on the angle
+between the electrical current and the spontaneous magnetization
+($\emph{\textbf{M}}_{S}$). A simple numerical treatment based on
+Stoner-Wolfarth model enables us to satisfactorily predict the magnetization
+behaviour observed in these films. A comparison between the results in
+Co$_{73.8}$Fe$_{16.2}$B$_{10}$ films and the previous ones obtained in annealed
+Co$_{80}$Fe$_{20}$ films, show that the introduction of boron in CoFe reduces
+significatively the coercive and saturation fields along the easy axis (e.g.
+$H_{c}$ from $\sim$ 2 down to $\sim$ 0.5 kAm$^{-1}$). Also, the magnetization
+along the hard axis saturates at lower fields. We conclude that amorphous and
+nanocrystalline CoFeB films show low coercive fields and abrupt switching, as
+well as absence of short range spin disorder effects after switching when
+compared with Co$_{80}$Fe$_{20}$.",0510479v2
+2011-02-10,Effects of hydrogen/deuterium absorption on the magnetic properties of Co/Pd multilayers,"The effects of hydrogen (H2) and deuterium (D2) absorption were studied in
+two Co/Pd multilayers with perpendicular magnetic anisotropy (PMA) using
+polarized neutron reflectivity (PNR). PNR was measured in an external magnetic
+field H applied in the plane of the sample with the magnetization M confined in
+the plane for {\mu}_o H= 6.0 T and partially out of plane at 0.65 T. Nominal
+thicknesses of the Co and Pd layers were 2.5 {\AA} and 21 {\AA}, respectively.
+Because of these small values, the actual layer chemical composition,
+thickness, and interface roughness parameters were determined from the nuclear
+scattering length density profile ({\rho}_n) and its derivative obtained from
+both x-ray reflectivity and PNR, and uncertainties were determined using Monte
+Carlo analysis. The PNR {\rho}_n showed that although D2 absorption occurred
+throughout the samples, absorption in the multilayer stack was modest (0.02 D
+per Pd atom) and thus did not expand. Direct magnetometry showed that H2
+absorption decreased the total M at saturation and increased the component of M
+in the plane of the sample when not at saturation. The PNR magnetic scattering
+length density ({\rho}_m) revealed that the Pd layers in the multilayer stack
+were magnetized and that their magnetization was preferentially modified upon
+D2 absorption. In one sample, a modulation of M with twice the multilayer
+period was observed at {\mu}_o H= 0.65 T, which increased upon D2 absorption.
+These results indicate that H2 or D2 absorption decreases both the PMA and
+total magnetization of the samples. The lack of measurable expansion during
+absorption indicates that these changes are primarily governed by modification
+of the electronic structure of the material.",1102.2260v1
+2016-09-12,"Magnetic, specific heat and electrical transport properties of Frank-Kasper cage compounds RTM$_2$Al$_{20}$ [R = Eu,Gd and La ; TM = V,Ti]","Single crystals of Frank-Kasper compounds RTM$_2$Al$_{20}$ (R = Eu, Gd and
+La; TM = V and Ti) were grown by self-flux method and their physical properties
+were investigated through magnetization ($M$), magnetic susceptibility
+($\chi$), specific heat ($C_P$) and electrical resistivity ($\rho$)
+measurements. Powder x-ray diffraction studies and structural analysis showed
+that these compounds crystallize in the cubic crystal structure with the space
+group $Fd\overline{3}m$. The magnetic susceptibility for the compounds
+EuTi$_2$Al$_{20}$ and GdTi$_2$Al$_{20}$ showed a sudden jump below the N{\'e}el
+temperature $T_N$ indicative of plausible double magnetic transition. Specific
+heat ($C_P$) and electrical resistivity ($\rho$) measurements also confirm the
+first-order magnetic transition (FOMT) and possible double magnetic
+transitions. Temperature variation of heat capacity showed a sharp phase
+transition and huge $C_P$ value for the (Eu/Gd)Ti$_2$Al$_{20}$ compounds Full
+width at half-maximum (FWHM) $<$ 0.2 K) which is reminiscent of a first-order
+phase transition and a unique attribute among RTM$_2$Al$_{20}$ compounds. We
+observed clear anomaly between heating and cooling cycle in temperature-time
+relaxation curve for the compounds GdTi$_2$Al$_{20}$ (2.38 $K$) and
+EuTi$_2$Al$_{20}$ (3.2 $K$) which is indicating a thermal arrest due to the
+latent heat. The temperature variation of $S_{mag}$ for GdTi$_2$Al$_{20}$
+saturates to a value $0.95R\ln8$ while the other magnetic systems exhibited
+still lower entropy saturation values in the high temperature limit.
+Resistivity measurements showed that all the samples behave as normal Fermi
+liquid type compounds and $\rho(T)$ due to electron-phonon scattering follows
+Bloch-Gr$\ddot{\textrm u}$neisen-Mott relation in the paramagnetic region.",1609.03458v1
+2022-03-21,Accurate Determination of the Electron Spin Polarization In Magnetized Iron and Nickel Foils for Møller Polarimetry,"The M{\o}ller polarimeter in Hall A at Jefferson Lab in Newport News, VA, has
+provided reliable measurements of electron beam polarization for the past two
+decades reaching the typically required $\pm$1\% level of absolute uncertainty.
+However, the upcoming proposed experimental program including MOLLER and SoLID
+have stringent requirements on beam polarimetry precision at the level of 0.4\%
+\cite{MOLLER2014, SoLID2019}, requiring a systematic re-examination of all the
+contributing uncertainties.
+  M{\o}ller polarimetry uses the double polarized scattering asymmetry of a
+polarized electron beam on a target with polarized atomic electrons. The target
+is a ferromagnetic material magnetized to align the spins in a given direction.
+In Hall A, the target is a pure iron foil aligned perpendicular to the beam and
+magnetized out of plane parallel or antiparallel to the beam direction. The
+acceptance of the detector is engineered to collect scattered electrons close
+to 90$^{\circ}$ in the center of mass frame where the analyzing power is a
+maximum (-7/9).
+  One of the leading systematic errors comes from determination of the target
+foil polarization. Polarization of a magnetically saturated target foil
+requires knowledge of both the saturation magnetization and $g^\prime$, the
+electron $g$-factor which includes components from both spin and orbital
+angular momentum from which the spin fraction of magnetization is determined.
+This paper utilizes the existing world data to provide a best estimate for
+target polarization for both nickel and iron foils including uncertainties in
+magnetization, high-field and temperature dependence, and fractional
+contribution to magnetization from orbital effects. We determine the foil
+electron spin polarization at 294~K to be 0.08020$\pm$0.00018 (@4~T applied
+field) for iron and 0.018845$\pm0.000053$ (@2~T applied field) for nickel.",2203.11238v2
+2024-01-15,Sensing magnetic flux of Langmuir-Blodgett films of a molecular magnetic system using superconducting films and nano-SQUID devices,"We report a study on the response of superconducitng micro-tracks and quantum
+interference devices (SQUIDs) to a proximal SMM film. As a test case,
+Langmuir-Blodgett $Mn_{12}$-ac SMM films have been grown on 2 $\mu$m wide Nb
+tracks and Nb nano-SQUIDs to observe the proximity effect of magnetic moment
+and magnetization tunneling, respectively. The superconducting critical
+temperature of thin Nb tracks (thinner than the coherence length of Nb) were
+found to decrease by the magnetic moment of $Mn_{12}$-ac SMM. Following the
+thermally activated flux flow (TAFF) model, we found an increase in the vortex
+unbinding energy of the SMM coated Nb tracks, near critical temperature. More
+importantly, the random alignment of moments of the $Mn_{12}$-ac molecules at
+low fields seemed to have the enhancing effect on vortex unbinding energy
+rather than the saturated state of $Mn_{12}$-ac molecules at high fields. In
+the fully superconducting state, on the other hand, the vortex pinning effects
+were found to be more effective in the saturated state of the $Mn_{12}$-ac
+molecules, as seen from magnetoresistance and field dependent critical current
+measurements. In a separate experiment, a Langmuir-Blodgett film of SMM was
+grown on a nano-SQUID to look for local changes in magnetization arising from
+magnetizatin tunnelling phenomenon in SMMs. Upon magnetizing the SMM (deposited
+on SQUIDs) at 2 K along the plane of the film and allowing it to relax, we
+found occasional jumps in the underlying SQUID voltage, unlike bare
+nano-SQUIDs, which did not show any such jumps over several hours. Therefore,
+we believe that the jumps in the SQUID voltage are the signatures of random
+tunneling of magnetization in the SMM layer.",2401.07566v2
+2014-05-05,Titanic Magnetoresistance in WTe2,"Magnetoresistance is the change of a material's electrical resistance in
+response to an applied magnetic field. In addition to its intrinsic scientific
+interest, it is a technologically important property, placing it in ""Pasteur's
+quadrant"" of research value: materials with large magnetorsistance have found
+use as magnetic sensors 1, in magnetic memory 2, hard drives 3, transistors 4,
+and are the subject of frequent study in the field of spintronics 5, 6. Here we
+report the observation of an extremely large one-dimensional positive
+magnetoresistance (XMR) in the layered transition metal dichalcogenide (TMD)
+WTe2; 452,700 percent at 4.5 Kelvin in a magnetic field of 14.7 Tesla, and 2.5
+million percent at 0.4 Kelvin in 45 Tesla, with no saturation. The XMR is
+highly anisotropic, maximized in the crystallographic direction where small
+pockets of holes and electrons are found in the electronic structure. The
+determination of the origin of this effect and the fabrication of
+nanostructures and devices based on the XMR of WTe2 will represent a
+significant new direction in the study and uses of magnetoresistivity.
+  *The published version of the paper includes co-authors Tian Liang and Max
+Hirschberger.
+  **This paper has been published with new MR data to 60T where the MR of WTe2
+reaches 13 million percent (at 0.5K) and still shows no signs of saturation. We
+also have new electron diffraction patterns to lower temperature (10K). We
+discuss the possible origin of the MR as coming from an electron-hole
+'resonance' condition established by a perfect n/p ratio of 1 (more details in
+a new ""extended data"" section). This makes WTe2, possibly, the first
+realization of a perfectly balanced semimetal.
+  ***The paper is published as ""Large non-saturating magnetoresistance in WTe2""
+in Nature (2014), DOI:10.1038/nature13763",1405.0973v3
+2001-01-22,Magnetically driven superluminal motion from rotating black holes,"We have investigated magnetically driven superluminal jets originating from
+rotating black holes. The stationary, general relativistic, magnetohydrodynamic
+wind equation along collimating magnetic flux surfaces has been solved
+numerically. In particular, we apply our results to the Galactic superluminal
+sources GRS 1915+105 and GRO 1655-40. Our results show that the observed speed
+of more than 0.9 c can be achieved in general by magnetohydrodynamic
+acceleration. The velocity distribution along the magnetic field has a
+saturating profile. Further, we find that highly relativistic speeds can be
+reached also for jets not emerging from a region close to the black hole, if
+the flow magnetization is sufficiently large. The plasma temperature rapidly
+decreases from about 10**10 K at the foot point of the jet to about 10**6 K at
+a distance of 5000 gravitational radii from the source. Temperature and the
+mass density follow a power law distribution with the radius.",0101373v1
+2003-06-03,Dynamo action in turbulent flows,"We present results from numerical simulations of nonlinear MHD dynamo action
+produced by three-dimensional flows that become turbulent for high values of
+the fluid Reynolds number. The magnitude of the forcing function driving the
+flow is allowed to evolve with time in such way as to maintain an approximately
+constant velocity amplitude (and average kinetic energy) when the flow becomes
+hydrodynamically unstable. It is found that the saturation level of the dynamo
+increases with the fluid Reynolds number (at constant magnetic Prandtl number),
+and that the average growth rate approaches an asymptotic value for high fluid
+Reynolds number. The generation and destruction of magnetic field is examined
+during the laminar and turbulent phase of the flow and it is found that in the
+neighborhood of strong magnetic ""flux cigars"" Joule dissipation is balanced by
+the work done against the Lorentz force, while the steady increase of magnetic
+energy occurs mainly through work done in the weak part of the magnetic field.",0306069v3
+2006-08-31,Nonlinear simulations of magnetic Taylor-Couette flow with current-free helical magnetic fields,"The magnetorotational instability (MRI) in cylindrical Taylor-Couette flow
+with external helical magnetic field is simulated for infinite and finite
+aspect ratios. We solve the MHD equations in their small Prandtl number limit
+and confirm with time-dependent nonlinear simulations that the additional
+toroidal component of the magnetic field reduces the critical Reynolds number
+from $O(10^6)$ (axial field only) to $O(10^3)$ for liquid metals with their
+small magnetic Prandtl number. Computing the saturated state we obtain velocity
+amplitudes which help designing proper experimental setups. Experiments with
+liquid gallium require axial field $\sim 50$ Gauss and axial current $\sim 4$
+kA for the toroidal field. It is sufficient that the vertical velocity $u_z$ of
+the flow can be measured with a precision of 0.1mm/s.
+  We also show that the endplates enclosing the cylinders do not destroy the
+traveling wave instability which can be observed as presented in earlier
+studies. For TC containers without and with endplates the angular momentum
+transport of the MRI instability is shown as to be outwards.",0608703v1
+1996-06-11,On Magnetic Impurities in Gapless Fermi Systems,"In ordinary metals, antiferromagnetic exchange between conduction electrons
+and a magnetic impurity leads to screening of the impurity spin below the Kondo
+temperature, $T_K$. In systems such as semimetals, small-gap semiconductors and
+unconventional superconductors, a reduction in available conduction states near
+the chemical potential can greatly depress $T_K$. The behavior of an Anderson
+impurity in a model with a power-law density of states, $N(\epsilon) \sim
+|\epsilon|^r$, $r>0$, for $|\epsilon| < \Delta$, where $\Delta \ll D$, is
+studied using the non-crossing approximation. The transition from the Kondo
+singlet to the magnetic ground state can be seen in the behavior of the
+impurity magnetic susceptibility $\chi$. The product $T\chi$ saturates at a
+finite value at low temperature for coupling smaller than the critical one. For
+sufficiently large coupling $T\chi \to 0$, as $T \to 0$, indicating complete
+screening of the impurity spin.",9606075v1
+1998-02-23,Magnetization under High Pressure in MnSi,"The magnetization M(H) has been measured in the weakly helimagnetic itinerant
+compound MnSi under high pressure up to 10.2 kbar and high magnetic field up to
+9 Tesla. We interpret the simultaneous decrease under pressure of the saturated
+magnetization, $p_s$, and the Curie temperature, $% T_c$ in the frame of the
+self-consistent renormalization theory (SCR) of spin fluctuations. From the
+analysis of the so-called Arrot-plot ($H/p [ H,T ] $ versus $p^2[ H,T ] $) and
+the respective volume dependence of $p_s$ and $T_c$, we estimate the evolution
+of the characteristic spin fluctuation temperatures, $T_0$ and $T_A$ when the
+system approaches its critical pressure, $P_c$=15 kbar, corresponding to the
+disappearance of the long range magnetic order at T=0.",9802238v1
+1998-08-27,Magnetization Plateaus in One Dimensional $Š=1/2$ Heisenberg Model with Dimerization and Quadrumerization,"The one dimensional $S=1/2$ Heisenberg model with dimerization ($1-j$) and
+quadrumerization ($\delta$) in the magnetic field is studied by means of the
+numerical exact diagonalization of finite size systems and the conformal field
+theory. It is found that the magnetization plateau at half of the saturation
+value exists for $\delta \neq 0$. For $\delta = 0$, this model is described by
+the conformal field theory with central charge $c=1$ at this value of
+magnetization. The critical exponent $\nu$ which characterizes the
+$\delta$-dependence of the width of the plateau is calculated using the level
+spectroscopy method. The $j$-dependence of the critical exponent $\nu$ is found
+to be non-monotonic and discontinuous at $j = 0$. The effective theory of the
+magnetization plateau is also presented for various limiting cases.",9808300v2
+1999-09-29,Magnetic Field Dependent Tunneling in Glasses,"We report on experiments giving evidence for quantum effects of
+electromagnetic flux in barium alumosilicate glass. In contrast to expectation,
+below 100 mK the dielectric response becomes sensitive to magnetic fields. The
+experimental findings include both, the complete lifting of the dielectric
+saturation by weak magnetic fields and oscillations of the dielectric response
+in the low temperature resonant regime. As origin of these effects we suggest
+that the magnetic induction field violates the time reversal invariance leading
+to a flux periodicity in the energy levels of tunneling systems. At low
+temperatures, this effect is strongly enhanced by the interaction between
+tunneling systems and thus becomes measurable.",9909425v1
+1999-10-26,Magnetotransport in nearly antiferromagnetic metals,"We present a theory of the magnetotransport in weakly disordered metals close
+to an antiferromagnetic quantum-critical point. The anisotropic scattering from
+critical spin fluctuations is strongly influenced by weak but isotropic
+scattering from small amounts of disorder. This leads to a large regime where
+the resistivity obeys a scaling form rho=rho_0+Delta rho = rho_0+T^{3/2}
+f(T/\rho_0,(p-p_c)/rho_0,B/rho_0^{3/2}), where rho_0 is the residual
+resistivity, B the magnetic field and p-p_c>0 measures the distance from the
+quantum-critical point on the paramagnetic side of the phase diagram. Orbital
+effects of the magnetic field are most pronounced in very clean samples for not
+too low temperatures, where the resistivity for increasing magnetic field
+crosses over from a linear temperature dependence Delta rho =T*sqrt{rho_0} to a
+resistivity linear in B and independent of T and rho_0. At higher magnetic
+fields Delta rho saturates at a value proportional to T^{1.5} or T^2/(p-p_c).
+Deviations from scaling, the interplay of orbital and spin contributions of the
+magnetic field and experimental test of the spin-fluctuation model are
+discussed in detail.",9910432v1
+2000-04-11,Antiferromagnetic Zigzag Spin Chain in Magnetic Fields at Finite Temperatures,"We study thermodynamic behaviors of the antiferromagnetic zigzag spin chain
+in magnetic fields, using the density-matrix renormalization group method for
+the quantum transfer matrix. We focus on the thermodynamics of the system near
+the critical fields in the ground-state magnetization process($M$-$H$ curve):
+the saturation field, the lower critical field associated with excitation gap,
+and the field at the middle-field cusp singularity. We calculate magnetization,
+susceptibility and specific heat of the zigzag chain in magnetic fields at
+finite temperatures, and then discuss how the calculated quantities reflect the
+low-lying excitations of the system related with the critical behaviors in the
+$M$-$H$ curve.",0004159v2
+2000-10-25,"Susceptibility, Magnetization Process and ESR Studies on the Helical Spin System RbCuCl$_{3}$","The static and dynamic magnetic properties of an $S=1/2$ stacked triangular
+antiferromagnet RbCuCl$_{3}$ with a helical spin structure due to lattice
+distortion were investigated by susceptibility, high-field magnetization
+process and ESR measurements. The susceptibilities were analyzed by
+high-temperature expansion approximation in terms of ferromagnetic intrachain
+coupling and the antiferromagnetic interchain coupling. The magnetization
+saturates at $H_{\rm s}\approx 66.8$ T at 1.5 K, the value of which is twice
+that of CsCuCl$_3$. A small magnetization jump indicative of a phase transition
+was observed at $H_{\rm c}=21.2$ T $\approx (1/3)H_{\rm s}$ for $H{\perp}c$.
+ESR modes observed for $H\parallel c$ are well described by the calculation
+based on the helical spin structure. From the present measurements, the
+ferromagnetic intrachain and two kinds of antiferromagnetic interchain exchange
+interactions, and the planar anisotropy energy were determined as $J_0/k_{\rm
+B}=25.7$ K, $J_1/k_{\rm B}=-10.6$ K, $J_1'/k_{\rm B}=-17.4$ K, and
+${\Delta}J_0/k_{\rm B}=-0.45$ K, respectively.",0010388v2
+2001-09-04,Magnetolocalization in disordered quantum wires,"The magnetic field dependent localization in a disordered quantum wire is
+considered nonperturbatively.
+  An increase of an averaged localization length with the magnetic field is
+found, saturating at twice its value without magnetic field.
+  The crossover behavior is shown to be governed both in the weak and strong
+localization regime by the magnetic diffusion length L_B. This function is
+derived analytically in closed form as a function of the ratio of the mean free
+path l, the wire thickness W, and the magnetic length l_B for a two-dimensional
+wire with specular boundary conditions, as well as for a parabolic wire. The
+applicability of the analytical formulas to resistance measurements in the
+strong localization regime is discussed. A comparison with recent experimental
+results on magnetolocalization is included.",0109060v1
+2001-11-28,Random Magnetism in $S=1/2$ Heisenberg Chains with Bond Alternation and Randomness on the Strong Bonds,"The $S=1/2$ Heisenberg chains with bond alternation and randomness on the
+strong bonds are studied by the density matrix renormalization group method. It
+is assumed that the odd-th bond is antiferromagnetic with strength $J$ and
+even-th bond can take the values $\JA$ and $\JF$ $ (\JA > J > 0 > \JF)$
+randomly. The ground state of this model interpolates between the Haldane and
+dimer phases via a randomness dominated intermediate phase. Based on the
+scaling of the low energy spectrum and mean field treatment of the interchain
+coupling, it is found that the magnetic long range order is induced by
+randomness in the intermediate regime. In the magnetization curves, there
+appears a plateau at the fractional value of the saturated magnetization. The
+fine structures of the magnetization curves and low energy spectrum are
+understood based on the cluster picture. The relation with the recent
+experiment for (CH$_3)_2$CHNH$_3$Cu(Cl$_x$Br$_{1-x})_3$ is discussed.",0111521v2
+2002-04-19,Optical and magnetic properties of Co-TiO2 sandwich Composite films grown by magnetron sputtering,"The transition metal ions doped with TiO2 films are of magnetic properties at
+room temperatures and have stimulated many scientists to study other
+properties. The Co-TiO2 sandwich composite films have been recently grown on
+glass and silicon substrates by using alternately radio frequency reactive and
+direct current magnetron sputtering. The microstructural properties of these
+films were characterized with Raman spectra and X-ray photoemission spectra
+(XPS). It shows an anatase TiO2 containing Co nano-layer. Optical absorption
+spectra have red shift with Co nano-layer increasing, which originated from the
+quantum confinement and tunnel effects. Magnetic properties show that the
+saturation magnetization, remanent magnetic induction and coercivity are about
+4.35 emu /g, 1.02 emu/g and 569.6 Oe respectively for 12 nm Co layer between
+the two TiO2 layers.",0204419v1
+2002-05-13,Direct visualization of iron sheath shielding effect in MgB_2 superconducting wires,"Local magneto-optical imaging and global magnetization measurement techniques
+were used in order to visualize shielding effects in the superconducting core
+of MgB_2 wires sheathed by ferromagnetic iron (Fe). The magnetic shielding can
+provide a Meissner-like state in the superconducting core in applied magnetic
+fields up to ~1T. The maximum shielding fields are shown to correlate with the
+saturation fields of magnetization in Fe-sheaths. The shielding has been found
+to facilitate the appearance of an overcritical state, which is capable of
+achieving a critical current density (J_c) in the core which is larger than J_c
+in the same wire without the sheath by a factor of ~2. Other effects caused by
+the magnetic interaction between the sheath and the superconducting core are
+discussed.",0205253v2
+2003-02-24,Magnetization study of RuSr2Y1.5Ce 0.5Cu2O10 (Ru-1222),"We have studied the magnetic properties of the non-superconducting
+RuSr2Ln1.5Ce0.5Cu2O10 (Ln=Y, Dy and Ho, Ru-1222) compounds synthesized under
+high pressure (6 Gpa) at elevated temperature. The materials become
+magnetically ordered at TM =152(2) K regardless of Ln. The wide
+ferromagnetic-like hysteresis loops which open at 5 K, close themselves around
+Tirr= 90-100 K and the remanent magnetizations (Mrem) and the coercive fields
+(HC) become zero. Surprisingly, at Tirr<T< TM a reappearance of the Mrem and HC
+(with a peak at 120-130 K) is observed for all three samples studied. For the
+non-magnetic Ln=Y compound, the extracted saturation moment at 5 K and the
+effective paramagnetic moment are is 0.75 and 2.05 mB /Ru, values which are
+close to the expected 1 mB and 1.73 mB respectively, for the low-spin state of
+Ru5+. We argue that the Ru-1222 system becomes (i) anti-ferromagnetically (AFM)
+ordered at TM. In this range a metamagnetic transition is induced by the
+applied field (ii). At Tirr < TM, weak-ferromagnetism (W-FM) is induced by the
+canting of the Ru moments.",0302475v1
+2004-04-27,Field-induced gap in ordered Heisenberg antiferromagnets,"Heisenberg antiferromagnets in a strong uniform magnetic field $H$ are
+expected to exhibit a gapless phase with a global O(2) symmetry. In many real
+magnets, a small energy gap is induced by additional interactions that can be
+viewed as a staggered transverse magnetic field $h = c H$, where $c$ is a small
+proportionality constant. We study the effects of such a perturbation,
+particularly for magnets with long-range order, by using several complimentary
+approaches: numerical diagonalizations of a model with long-range interactions,
+classical equations of motion, and scaling arguments. In an ordered state at
+zero temperature, the energy gap at first grows as $(cH)^{1/2}$ and then may
+dip to a smaller value, of order $(cH)^{2/3}$, at the quantum critical point
+separating the ``gapless'' phase from the gapped state with saturated
+magnetization. In one spatial dimension, the latter exponent changes to 4/5.",0404636v2
+2004-06-10,Influence of randomly distributed magnetic nanoparticles on surface superconductivity in Nb films,"We report on combined resistance and magnetic measurements in a hybrid
+structure (HS) of randomly distributed anisotropic CoPt magnetic nanoparticles
+(MN) embedded in a 160 nm Nb thick film. Our resistance measurements exhibited
+a sharp increase at the magnetically determined bulk upper-critical fields
+Hc2(T). Above these points the resistance curves are rounded, attaining the
+normal state value at much higher fields identified as the surface
+superconductivity fields Hc3(T). When plotted in reduced temperature units, the
+characteristic field lines Hc3(T) of the HS and of a pure Nb film, prepared at
+exactly the same conditions, coincide for H<10 kOe, while for fields H>10 kOe
+they strongly segregate. Interestingly, the characteristic value H=10 kOe is
+equal to the saturation field of the MN. The behavior mentioned above is
+observed only for the case where the field is normal to the HS, while is absent
+when the field is parallel to the film. Our experimental results suggest that
+the observed enhancement of surface superconductivity field Hc3(T) is possibly
+due to the not uniform local reduction of the external magnetic field by the
+dipolar fields of the MN.",0406235v1
+2004-12-09,Finite-Field Ground State of the S=1 Antiferromagnetic-Ferromagnetic Bond-Alternating Chain,"We investigate the finite-field ground state of the S=1
+antiferromagnetic-ferromagnetic bond-alternating chain described by the
+Hamiltonian
+${\calH}=\sum\nolimits_{\ell}\bigl\{\vecS_{2\ell-1}\cdot\vecS_{2\ell}
++J\vecS_{2\ell}\cdot\vecS_{2\ell+1}\bigr\} +D\sum\nolimits_{\ell}
+\bigl(S_{\ell}^z)^2 -H\textstyle\sum\nolimits_\ell S_\ell^z$, where
+\hbox{$J\leq0$} and \hbox{$-\infty<D<\infty$}. We find that two kinds of
+magnetization plateaux at a half of the saturation magnetization, the
+1/2-plateaux, appear in the ground-state magnetization curve; one of them is of
+the Haldane type and the other is of the large-$D$-type. We determine the
+1/2-plateau phase diagram on the $D$ versus $J$ plane, applying the
+twisted-boundary-condition level spectroscopy methods developed by Kitazawa and
+Nomura. We also calculate the ground-state magnetization curves and the
+magnetization phase diagrams by means of the density-matrix
+renormalization-group method.",0412234v1
+2005-10-07,The many-electron ground-state determines uniquely the potential in Spin-Density-Functional Theory for non-collinear magnetism,"Since Spin Density Functional Theory was first proposed, but also recently,
+examples were constructed to show that a spin-potential may share its ground
+state with other spin-potentials. In fact, for collinear magnetic fields and
+systems with fixed magnetization, the mapping between potentials and ground
+states is invertible, provided the magnetization is not saturated and that
+spin-potentials are determined within a spin-constant. We complete the proof
+that the mapping is invertible also for non-collinear magnetic fields and
+systems with more than one electron. We then discuss the non-collinear exchange
+and correlation energy functional and suggest improvements.",0510199v4
+2005-10-20,Current-driven magnetization switching in CoFeB/MgO/CoFeB magnetic tunnel junctions,"Current-driven magnetization switching in low-resistance
+Co40Fe40B20/MgO/Co40Fe40B20 magnetic tunnel junctions (MTJs) is reported. The
+critical-current densities Jc required for current-driven switching in samples
+annealed at 270C and 300C are found to be as low as 7.8 x 10^5 A/cm^2 and 8.8 x
+10^5 A/cm^2 with accompanying tunnel magnetoresistance (TMR) ratios of 49% and
+73 %, respectively. Further annealing of the samples at 350C increases TMR
+ratio to 160 %, while accompanying Jc increases to 2.5 x 10^6 A/cm^2. We
+attribute the low Jc to the high spin-polarization of tunnel current and small
+MsV product of the CoFeB single free layer, where Ms is the saturation
+magnetization and V the volume of the free layer.",0510538v1
+2006-04-05,Interparticle interaction and size effect in polymer coated magnetite nanoparticles,"Magnetization and Mossbauer studies have been performed on the polymer coated
+magnetite nanoparticles with particle size from 5.1 to 14.7 nm. The maximum in
+the temperature dependence of magnetization (TM) is found to be inconsistent
+with the particle size (DTEM). The effective magnetic anisotropy (Kan) is found
+to increase with the decrease of DTEM, which is attributed to the increase of
+surface anisotropy. The absence of coercivity and remanence of magnetization
+noticed well above TM indicates the superparamagnetic behaviour, which has also
+been observed in the temperature dependent Mossbauer results. The temperature
+dependence of hyperfine field is found to follow similar dependence of
+saturation magnetization for bulk magnetite.",0604119v2
+2006-12-06,Coexistence of vector chiral order and Tomonaga-Luttinger liquid in the frustrated three-leg spin tube in a magnetic field,"The frustrated three-leg antiferromagnetic spin-1/2 tube with a weak
+interchain coupling in a magnetic field is investigated by means of Abelian
+bosonization techniques. It is clearly shown that a vector chiral order and a
+one-component Tomonaga-Luttinger liquid coexist in a wide magnetic-field region
+from a state with a small magnetization to a nearly saturated one. The chiral
+order is predicted to still survive in the intermediate plateau state. We
+further predict that (even) when the strength of one bond in the three rung
+couplings is decreased (increased), an Ising type quantum phase transition
+takes place and the chirality vanishes (no singular phenomena occur and the
+chiral order is maintained). Even without magnetic fields, the chiral order
+would also be present, if the spin tube possess easy-plane anisotropy.",0612165v3
+2007-02-14,Vortices and chirality of magnetostatic modes in quasi-2D ferrite disk particles,"In this paper we show that the vortex states can be created not only in
+magnetically soft ""small"" (with the dipolar and exchange energy competition)
+cylindrical dots, but also in magnetically saturated ""big"" (when the exchange
+is neglected) cylindrical dots. A property associated with a vortex structure
+becomes evident from an analysis of confinement phenomena of magnetic
+oscillations in a ferrite disk with a dominating role of magnetic-dipolar
+(non-exchange-interaction) spectra. In this case the scalar
+(magnetostatic-potential) wave functions may have a phase singularity in a
+center of a dot. A non-zero azimuth component of the flow velocity demonstrates
+the vortex structure. The vortices are guaranteed by the chiral edge states of
+magnetic-dipolar modes in a quasi-2D ferrite disk.",0702327v1
+1992-09-26,Saddle point solutions in Yang-Mills-dilaton theory,"The coupling of a dilaton to the $SU(2)$-Yang-Mills field leads to
+interesting non-perturbative static spherically symmetric solutions which are
+studied by mixed analitical and numerical methods. In the abelian sector of the
+theory there are finite-energy magnetic and electric monopole solutions which
+saturate the Bogomol'nyi bound. In the nonabelian sector there exist a
+countable family of globally regular solutions which are purely magnetic but
+have zero Yang-Mills magnetic charge. Their discrete spectrum of energies is
+bounded from above by the energy of the abelian magnetic monopole with unit
+magnetic charge. The stability analysis demonstrates that the solutions are
+saddle points of the energy functional with increasing number of unstable
+modes. The existence and instability of these solutions are ""explained"" by the
+Morse-theory argument recently proposed by Sudarsky and Wald.",9209106v1
+2007-05-24,Magnetic helicity effects in astrophysical and laboratory dynamos,"Magnetic helicity effects are discussed in laboratory and astrophysical
+settings. First, dynamo action in Taylor-Green flows is discussed for different
+boundary conditions. However, because of the lack of scale separation with
+respect to the container, no large scale field is being produced and there is
+no resistively slow saturation phase as otherwise expected. Second, the
+build-up of a large scale field is demonstrated in a simulation where a
+localized magnetic eddy produces field on a larger scale if the eddy possesses
+a swirl. Such a set-up might be realizable experimentally through coils.
+Finally, new emerging issues regarding the connection between magnetic helicity
+and the solar dynamo are discussed. It is demonstrated that dynamos with a
+non-local (Babcock-Leighton type) alpha effect can also be catastrophically
+quenched, unless there are magnetic helicity fluxes.",0705.3507v1
+2007-06-19,Quenched magnetic moment in Mn-doped amorphous Si (\textit{a}-Mn$_{x}$Si$_{1-x}$) across the metal-insulator transition,"The magnetic and electrical transport properties of Mn-doped amorphous
+silicon (\textit{a-}Mn$_{x}$Si$_{1-x}$) thin films have been measured. The
+magnetic susceptibility obeys the Curie-Weiss law for a wide range of $x$
+(0.005-0.175) and the saturation moment is small. While all Mn atoms contribute
+to the electrical transport, only a small fraction (interstitial Mn$^{2+}$
+states with $J$=$S$=5/2) contribute to the magnetization. The majority of the
+Mn atoms do not possess any magnetic moment, contrary to what is predicted by
+the Ludwig-Woodbury model for Mn in crystalline silicon. Unlike
+\textit{a-}Gd$_{x}$Si$_{1-x}$ films which have an enormous \textit{negative}
+magnetoresistance, \textit{a-}Mn$_{x}$Si$_{1-x}$ films have only a small
+\textit{positive} magnetoresistance, which can be understood by this quenching
+of the Mn moment.",0706.2847v1
+2008-02-20,Magnetizing the universe,"The origin of cosmic magnetism is an issue of fundamental importance in
+astrophysics. We review here some of the ideas of how large scale magnetic
+fields in the universe, particularly in galaxies and galaxy clusters could
+arise. The popular paradigm involves the generation of a seed magnetic field
+followed by turbulent dynamo amplification of the seed field. We first outline
+various seed field generation mechanisms including Biermann batteries. These in
+general give a field much smaller than the observed field and so they require
+further amplification by dynamo action. The basic idea behind fluctuation
+dynamos, as applied to cluster magnetism and the mean-field helical dynamo as
+applied to disk galaxies, are outlined. Major difficulties with the dynamo
+paradigm are considered. It is particularly important to understand the
+nonlinear saturation of dynamos, and whether the fields produced are coherent
+enough on large-scales to explain the observed fields in galaxies and clusters.
+At the same time the alternative possibility of a primordial field lacks firm
+theoretical support but can have very interesting observational consequences.",0802.2804v1
+2008-03-25,Magnetic properties of BaCdVO(PO_4)_2: a strongly frustrated spin-1/2 square lattice close to the quantum critical regime,"We report magnetization and specific heat measurements on polycrystalline
+samples of BaCdVO(PO_4)_2 and show that this compound is a S=1/2 frustrated
+square lattice with ferromagnetic nearest-neighbor (J_1) and antiferromagnetic
+next-nearest-neighbor (J_2) interactions. The coupling constants J_1\simeq -3.6
+K and J_2\simeq 3.2 K are determined from a fitting of the susceptibility data
+and confirmed by an analysis of the saturation field (H_s=4.2 T), the specific
+heat, and the magnetic entropy. BaCdVO(PO_4)_2 undergoes magnetic ordering at
+about 1 K, likely towards a columnar antiferromagnetic state. We find that
+BaCdVO(PO_4)_2 with the frustration ratio \alpha=J_2/J_1\simeq -0.9 is closer
+to a critical (quantum spin liquid) region of the frustrated square lattice
+than any of the previously reported compounds. Positive curvature of the
+magnetization curve is observed in agreement with recent theoretical
+predictions for high-field properties of the frustrated square lattice close to
+the critical regime.",0803.3535v2
+2008-05-02,Commensurate Spin Density Wave in LaOFeAs: A Local Probe Study,"We present a detailed study on the magnetic order in the undoped mother
+compound LaOFeAs of the recently discovered Fe-based superconductor
+LaO$_{1-x}$F$_x$FeAs. In particular, we present local probe measurements of the
+magnetic properties of LaOFeAs by means of $^{57}$Fe M\""ossbauer spectroscopy
+and muon spin relaxation in zero external field along with magnetization and
+resistivity studies. These experiments prove a commensurate static magnetic
+order with a strongly reduced ordered moment of 0.25(5) $\mu_B$ at the iron
+site below T_N = 138 K, well separated from a structural phase transition at
+T_N = 156 K. The temperature dependence of the sublattice magnetization is
+determined and compared to theory. Using a four-band spin density wave model
+both, the size of the order parameter and the quick saturation below T_N are
+reproduced.",0805.0264v2
+2008-08-03,Magnetic and Transport Studies on Electron-doped CeFeAsO1-xFx Superconductor,"The magnetic and transport behaviors of cerium substituted iron oxy-arsenide
+superconductor with x = 0.1 to 0.4 fluoride (F) doping have been investigated
+in this report. Temperature dependent susceptibility and resistivity
+measurements showed the 0.1 F-doped sample (CeFeAsO0.9F0.1) has a
+superconducting transition temperature (Tc) of around 30 K. With increasing
+doping beyond x = 0.2 Tc saturates to around 40 K. Temperature dependent
+susceptibility measured in different magnetic fields for the under-doped sample
+showed Meissner effect in low field and the diamagnetism is still visible up to
+1 Tesla, with an obvious magnetic transition below 5 K, perhaps originating
+from magnetic ordering of the rare earth cerium. The corresponding field
+dependent resistance versus temperature measurements indicated a broadening of
+less than 3 K for Tc at mid-point by increasing the field to 5 Tesla indicating
+rather low anisotropy. An estimated upper critical field of more than 48 Tesla
+and accordingly an estimated maximum coherence length of 2.6 nm were obtained
+confirming the high upper critical field with a short coherence length for this
+superconductor.",0808.0296v1
+2008-08-07,The dual role of shear in large-scale dynamos,"The role of shear in alleviating catastrophic quenching by shedding
+small-scale magnetic helicity through fluxes along contours of constant shear
+is discussed. The level of quenching of the dynamo effect depends on the
+quenched value of the turbulent magnetic diffusivity. Earlier estimates that
+might have suffered from the force-free degeneracy of Beltrami fields are now
+confirmed for shear flows where this degeneracy is lifted. For a dynamo that is
+saturated near equipartition field strength those estimates result in a 5-fold
+decrease of the magnetic diffusivity as the magnetic Reynolds number based on
+the wavenumber of the energy-carrying eddies is increased from 2 to 600.
+Finally, the role of shear in driving turbulence and large-scale fields by the
+magneto-rotational instability is emphasized. New simulations are presented and
+the 3pi/4 phase shift between poloidal and toroidal fields is confirmed. It is
+suggested that this phase shift might be a useful diagnostic tool in
+identifying mean-field dynamo action in simulations and to distinguish this
+from other scenarios invoking magnetic buoyancy as a means to explain migration
+away from the midplane.",0808.0959v1
+2008-09-30,Magnetization Process of the Classical Heisenberg Model on the Shastry-Sutherland Lattice,"We investigate classical Heisenberg spins on the Shastry-Sutherland lattice
+and under an external magnetic field. A detailed study is carried out both
+analytically and numerically by means of classical Monte-Carlo simulations.
+Magnetization pseudo-plateaux are observed around 1/3 of the saturation
+magnetization for a range of values of the magnetic couplings. We show that the
+existence of the pseudo-plateau is due to an entropic selection of a particular
+collinear state. A phase diagram that shows the domains of existence of those
+pseudo-plateaux in the $(h, T)$ plane is obtained.",0809.5249v2
+2008-11-26,The Fate of the Sound and Diffusion in Holographic Magnetic Field,"It was shown in arXiv:0810.4094 [hep-th] that in the presence of the magnetic
+field the sound waves in (2+1) dimensional plasma disappear and are replaces by
+a diffusive mode. Similarly, the shear and charge diffusion fluctuations form a
+subdiffusive mode. However, since the limit of small magnetic field does not
+commute with the hydrodynamic limit it is not obvious whether or not these
+modes are stable under higher order corrections. Using AdS/CFT correspondence
+we show that in the case of M2-brane plasma these modes do exist as we find the
+corresponding supergravity solutions. This allowed us to compute the
+conductivity and the shear viscosity to all orders in magnetic field. We find
+that the viscosity to entropy ratio saturates the Kovtun-Son-Starinets bound.
+This extends the universality property of the shear viscosity to the case of
+the strongly coupled plasma in external magnetic field.",0811.4325v2
+2009-01-28,Epitaxial growth and magnetic properties of Sr2CrReO6 thin films,"The double perovskite Sr2CrReO6 is an interesting material for spintronics,
+showing ferrimagnetism up to 635 K with a predicted high spin polarization of
+about 86%. We fabricated Sr2CrReO6 epitaxial films by pulsed laser deposition
+on (001)-oriented SrTiO3 substrates. Phase-pure films with optimum
+crystallographic and magnetic properties were obtained by growing at a
+substrate temperature of 700 degree C in pure O2 of 6.6x10-4 mbar. The films
+are c-axis oriented, coherently strained, and show less than 20% anti-site
+defects. The magnetization curves reveal high saturation magnetization of 0.8
+muB per formula unit and high coercivity of 1.1 T, as well as a strong magnetic
+anisotropy.",0901.4499v1
+2009-01-30,Hysteresis and complexity in the zero-temperature mean-field RFIM: the soft-spin version,"We study the energy landscape of the soft-spin random field model in the
+mean-field limit and compute analytically the quenched complexity of the
+metastable states as a function of their magnetization and energy at a given
+external magnetic field. The shape of the domain within which the complexity is
+positive (and the number of typical metastable states grows exponentially with
+system size) changes with the amount of disorder and becomes non-convex and
+disconnected at low disorder. As a consequence, phase transitions occur both at
+equilibrium and out of equilibrium along the saturation hysteresis loop. We
+focus on the zero complexity curve in the field-magnetization plane and its
+relationship with the hysteresis loop. We also study the response of the system
+when the magnetization is externally controlled instead of the magnetic field.
+The main features of the model that should survive in finite dimensions are
+discussed.",0901.4852v1
+2009-04-27,Effect of resistance feedback on spin torque-induced switching of nanomagnets,"In large magnetoresistance devices spin torque-induced changes in resistance
+can produce GHz current and voltage oscillations which can affect magnetization
+reversal. In addition, capacitive shunting in large resistance devices can
+further reduce the current, adversely affecting spin torque switching. Here, we
+simultaneously solve the Landau-Lifshitz-Gilbert equation with spin torque and
+the transmission line telegrapher's equations to study the effects of
+resistance feedback and capacitance on magnetization reversal of both spin
+valves and magnetic tunnel junctions. While for spin valves parallel (P) to
+anti-parallel (AP) switching is adversely affected by the resistance feedback
+due to saturation of the spin torque, in low resistance magnetic tunnel
+junctions P-AP switching is enhanced. We study the effect of resistance
+feedback on the switching time of MTJ's, and show that magnetization switching
+is only affected by capacitive shunting in the pF range.",0904.4159v2
+2009-09-25,Effect of Fe substitution on magnetocaloric effect in La0.7Sr0.3Mn1-xFexO3 (x = 0 to 0.2),"We have studied the effect of Fe substitution on magnetic and magnetocaloric
+properties in La0.7Sr0.3Mn1-xFexO3 (x = 0.05, 0.07, 0.10, 0.15, and 0.20) over
+a wide temperature range (T = 10-400 K). It is shown that substitution by Fe
+gradually decreases the ferromagnetic Curie temperature (Tc) and saturation
+magnetization up to x = 0.15 but a dramatic change occurs for x = 0.2. The x =
+0.2 sample can be considered as a phase separated compound in which both
+short-range ordered ferromagnetic and antiferromagnetic phases coexist. The
+magnetic entropy change (DSm) was estimated from isothermal magnetization
+curves and it decreases with increase of Fe content from 4.4 J/KgK at 343 K (x
+= 0.05) to 1.3 J/KgK at 105 K (x = 0.2), under H = 5 T. The
+La0.7Sr0.3Mn0.93Fe0.07O3 sample shows negligible hysteresis loss, operating
+temperature over 60 K range around room temperature with refrigerant capacity
+of 225 J/Kg, and magnetic entropy of 4 J/kgK which will be an interesting
+compound for application in room temperature refrigeration.",0909.4619v1
+2009-10-21,Magnetic properties of the spin-1/2 XXZ model on the Shastry-Sutherland lattice: Effect of long-range interactions,"We study magnetic properties of the $S=1/2$ Ising-like XXZ model on the
+Shastry-Sutherland lattices with long-range interactions, using the quantum
+Monte Carlo method. This model shows magnetization plateau phases at one-half
+and one-third of the saturation magnetization when additional couplings are
+considered. We investigate the finite temperature transition to one-half and
+one-third plateau phases. The obtained results suggest that the former case is
+of the first order and the latter case is of the second order. We also find
+that the system undergoes two successive transitions with the 2D Ising model
+universality, although there is a single phase transition in the Ising limit
+case. Finally, we estimate the coupling ratio to explain the magnetization
+process observed in ${\rm TmB_4}$",0910.4162v1
+2010-01-21,Magnetic phase transitions in SmCoAsO,"Magnetization, x-ray diffraction and specific-heat measurements reveal that
+SmCoAsO undergoes three magnetic phase transitions. A ferromagnetic transition
+attributed to the Co ions, emerges at TC=57 K with a small saturation moment of
+0.15muB/Co. Reorientation of the Co moment to an antiferromagnetic state is
+obtained at TN2=45 K. The relative high paramagnetic effective moment Peff=1.57
+MuB/Co indicates an itinerant ferromagnetic state of the Co sublattice. The
+third magnetic transition at TN1=5 K is observed clearly in the specific-heat
+study only. Both magnetic and 57Fe Mossbauer studies show that substitution of
+small quantities of Fe for Co was unsuccessful.",1001.3719v3
+2010-04-14,Magnetorotational instability driven dynamos at low magnetic Prandtl numbers,"Numerical simulations of the magnetorotational instability (MRI) with zero
+initial net flux in a non-stratified isothermal cubic domain are used to
+demonstrate the importance of magnetic boundary conditions.In fully periodic
+systems the level of turbulence generated by the MRI strongly decreases as the
+magnetic Prandtl number (Pm), which is the ratio of kinematic viscosity and
+magnetic diffusion, is decreased. No MRI or dynamo action below Pm=1 is found,
+agreeing with earlier investigations. Using vertical field conditions, which
+allow the generation of a net toroidal flux and magnetic helicity fluxes out of
+the system, the MRI is found to be excited in the range 0.1 < Pm < 10, and that
+the saturation level is independent of Pm. In the vertical field runs strong
+mean-field dynamo develops and helps to sustain the MRI.",1004.2417v2
+2010-05-03,Giant magnetic moment enhancement of nickel nanoparticles embedded in multi-walled carbon nanotubes,"We report a giant magnetic moment enhancement of ferromagnetic nickel
+nanoparticles (11 nm) embedded in multi-walled carbon nanotubes. High-energy
+synchrotron x-ray diffraction experiment and chemical analysis are used to
+accurately determine the ferromagnetic nickel concentration. Magnetic
+measurements up to 900 K show an intriguing result-the saturation magnetization
+of the nickel nanoparticles embedded in the multi-walled carbon nanotubes is
+about 3.4 times as much as the value expected from the measured nickel
+concentration while the Curie temperature is the same as that of bulk nickel.
+The implication of this giant magnetic moment enhancement, whatever its origin,
+is likely to be far reaching-it opens a new avenue for implementing
+spin-electronics at the molecular level.",1005.0350v1
+2010-06-01,"Synthesis, structural and physical properties of $δ'$-FeSe$_{1-x}$","We report on synthesis, structural characterization, resistivity, magnetic
+and thermal expansion measurements on the as yet unexplored $\delta'$-phase of
+FeSe$_{1-x}$, here synthesized under ambient- (AP) and high-pressure (HP)
+conditions. We show that in contrast to $\beta$-FeSe$_{1-x}$, monophasic
+superconducting $\delta'$-FeSe$_{1-x}$ can be obtained in off-stoichiometric
+samples with excess Fe atoms preferentially residing in the van der Waals gap
+between the FeSe layers. The AP $\delta'$-FeSe$_{1-x}$ sample studied here
+($T_c$ $\simeq$ 8.5\,K) possesses an unprecedented residual resistivity ratio
+RRR $\simeq$ 16. Thermal expansion data reveal a small feature around
+$\sim$90\,K, which resembles the anomaly observed at the structural and
+magnetic transitions for other Fe-based superconductors, suggesting that some
+kind of ""magnetic state"" is formed also in FeSe. %indicative of a fluctuating
+magnetic ordering. For HP samples (RRR $\simeq$ 3), the disorder within the
+FeSe layers is enhanced through the introduction of vacancies, the saturated
+magnetic moment of Fe is reduced and only spurious superconductivity is
+observed.",1006.0073v2
+2010-06-08,Effect of pressure on magnetization and magnetostriction jumps in the manganite Eu$_{0.58}$Sr$_{0.42}$MnO$_{3}$,"We have demonstrated the effect of pressure on magnetization jump and its
+associated magnetostriction in Eu$_{0.58}$Sr$_{0.42}$MnO$_{3}$. The critical
+field lowered by the applied pressure is explained by a suppression of the
+metastable blocked state, which is inherent to the phase separated manganite
+system exhibiting the magnetic avalanche. To reduce a factor of the bad thermal
+coupling in the bulk sample, and to further examine the nature of the
+magnetization jump, we have performed the influence of pressure on the
+isothermal magnetization of the powder sample. There is no discrepancy in the
+critical field between the bulk and powder samples although the $MH$ curve of
+the latter is not saturated at high fields. These findings indicate a crucial
+role of the frozen phase separated state in the abrupt transition.",1006.1459v3
+2010-06-15,PIC Simulations of the Temperature Anisotropy-Driven Weibel Instability: Analyzing the perpendicular mode,"An instability driven by the thermal anisotropy of a single electron species
+is investigated in a 2D particle-in-cell (PIC) simulation. This instability is
+the one considered by Weibel and it differs from the beam driven filamentation
+instability. A comparison of the simulation results with analytic theory
+provides similar exponential growth rates of the magnetic field during the
+linear growth phase of the instability. We observe in accordance with previous
+works the growth of electric fields during the saturation phase of the
+instability. Some components of this electric field are not accounted for by
+the linearized theory. A single-fluid-based theory is used to determine the
+source of this nonlinear electric field. It is demonstrated that the magnetic
+stress tensor, which vanishes in a 1D geometry, is more important in this
+2-dimensional model used here. The electric field grows to an amplitude, which
+yields a force on the electrons that is comparable to the magnetic one. The
+peak energy density of each magnetic field component in the simulation plane
+agrees with previous estimates. Eddy currents develop, which let the amplitude
+of the third magnetic field component grow, which is not observed in a 1D
+simulation.",1006.3057v1
+2010-12-25,Magnetic Properties and Thermal Entanglement on a Triangulated Kagome Lattice,"The magnetic and entanglement thermal (equilibrium) properties in spin-1/2
+Ising-Heisenberg model on a triangulated Kagome lattice are analyzed by means
+of variational mean-field like treatment based on Gibbs-Bogoliubov inequality.
+Because of the separable character of Ising-type exchange interactions between
+the Heisenberg trimers the calculation of quantum entanglement in a
+self-consistent field can be performed for each of the trimers individually.
+The concurrence in terms of three qubit isotropic Heisenberg model in effective
+Ising field is non-zero even in the absence of a magnetic field. The magnetic
+and entanglement properties exhibit common (plateau and peak) features
+observable via (antferromagnetic) coupling constant and external magnetic
+field. The critical temperature for the phase transition and threshold
+temperature for concurrence coincide in the case of antiferromagnetic coupling
+between qubits. The existence of entangled and disentangled phases in saturated
+and frustrated phases is established.",1012.5478v1
+2011-03-22,Magnetic Interactions in Ball-Milled Spinel Ferrites,"Spinel Fe3O4 nanoparticles have been produced through ball milling in
+methyl-alcohol (CH3OH), aiming to obtain samples with similar average particle
+sizes <d> and different interparticle interactions. Three samples having
+Fe3O4/CH3(OH) mass ratios R of 3 %, 10 % and 50 % wt. were milled for several
+hours until particle size reached a steady value (<d> ~ 7-10 nm). A detailed
+study of static and dynamic magnetic properties has been undertaken by
+measuring magnetization, ac susceptibility and M\""ossbauer data. As expected
+for small particles, the Verwey transition was not observed, but instead
+superparamagnetic (SPM) behavior was found with transition to a blocked state
+at TB ~ 10-20 K. Spin disorder of the resulting particles, independent of its
+concentration, was inferred from the decrease of saturation magnetization MS at
+low temperatures. For samples having 3% wt. of magnetic particles, dynamic ac
+susceptibility measurements show a thermally activated Arrhenius dependence of
+the blocking temperature with applied frequency. This behaviour is found to
+change as interparticle interactions begin to rule the dynamics of the system,
+yielding a spin-glass-like state at low temperatures for R = 50 wt.% sample.",1103.4390v1
+2011-04-08,Magnetic nanocomposites at microwave frequencies,"Most conventional magnetic materials used in the electronic devices are
+ferrites, which are composed of micrometer-size grains. But ferrites have small
+saturation magnetization, therefore the performance at GHz frequencies is
+rather poor. That is why functionalized nanocomposites comprising magnetic
+nanoparticles (e.g. Fe, Co) with dimensions ranging from a few nm to 100 nm,
+and embedded in dielectric matrices (e.g. silicon oxide, aluminium oxide) have
+a significant potential for the electronics industry. When the size of the
+nanoparticles is smaller than the critical size for multidomain formation,
+these nanocomposites can be regarded as an ensemble of particles in
+single-domain states and the losses (due for example to eddy currents) are
+expected to be relatively small. Here we review the theory of magnetism in such
+materials, and we present a novel measurement method used for the
+characterization of the electromagnetic properties of composites with
+nanomagnetic insertions. We also present a few experimental results obtained on
+composites consisting of iron nanoparticles in a dielectric matrix.",1104.1535v1
+2011-07-01,Catastrophic quenching in alpha-Omega dynamos revisited,"At large magnetic Reynolds numbers, magnetic helicity evolution plays an
+important role in astrophysical large-scale dynamos. The recognition of this
+fact led to the development of the dynamical alpha quenching formalism, which
+predicts catastrophically low mean fields in open systems. Here we show that in
+oscillatory alpha-Omega dynamos this formalism predicts an unphysical magnetic
+helicity transfer between scales. An alternative technique is proposed where
+this artifact is removed by using the evolution equation for the magnetic
+helicity of the total field in the shearing--advective gauge. In the
+traditional dynamical alpha quenching formalism, this can be described as an
+additional magnetic helicity flux of small-scale fields that does not appear in
+homogeneous alpha-squared dynamos. In alpha-Omega dynamos, the alternative
+formalism is shown to lead to larger saturation fields than previously obtained
+with the traditional formalism.",1107.0238v2
+2011-08-31,Multicore magnetite nanoparticles prepared by glass crystallisation and their magnetic properties,"A potassium alumina borosilicate glass with the composition
+13K2O*13Al2O3*16B2O3*43SiO2*15Fe2O3-x was melted using Fe2O3 as raw material.
+The melt was dumped from a Pt-crucible with a downpipe in water which resulted
+in the formation of phase separated droplets with a size of around 100 - 150
+nm. In this droplets, magnetite crystals with a size of around 10-20 nm were
+observed. These magnetite nanoparticles with superparamagnetic behaviour are
+arranged to larger aggregates. This leads to a higher effective magnetic
+radius. According to magnetisation measurements the particles show hysteresis.
+The ratio of remanent vs. saturation magnetisation is not as high as it is
+necessary for uniaxial anisotropy. It is possible to elude the phase
+separations by cooking the pulverized glass in concentrated sodium hydroxide.
+Additional temperature dependent magnetorelaxometry (TMRX) measurements show in
+the distribution of the relaxation of magnetic moments over the course of
+temperature two peaks at 13 and 39 K. According to an interparticle distance
+smaller than 5 dC (the core diameter) could that be a result of strong magnetic
+interactions. Other magnetic relaxation processes also explain this measured
+effect.",1108.6201v1
+2011-09-19,Axial dipolar dynamo action in the Taylor-Green vortex,"We present a numerical study of the magnetic field generated by the
+Taylor-Green vortex. We show that periodic boundary conditions can be used to
+mimic realistic boundary conditions by prescribing the symmetries of the
+velocity and magnetic fields. This gives insight in some problems of central
+interest for dynamos: the possible effect of velocity fluctuations on the
+dynamo threshold, the role of boundary conditions on the threshold and on the
+geometry of the magnetic field generated by dynamo action. In particular, we
+show that an axial dipolar dynamo similar to the one observed in a recent
+experiment can be obtained with an appropriate choice of the symmetries of the
+magnetic field. The nonlinear saturation is studied and a simple model
+explaining the magnetic Prandtl number dependence of the super/sub critical
+nature of the dynamo transition is given.",1109.4063v2
+2011-11-04,Orthogonal spin arrangement as possible ground state of three - dimensional Shastry - Sutherland network in Ba3Cu3In4O12,"The Ba3Cu3In4O12 stands for unique topology of the magnetic subsystem. It
+consists of rotated by 90\Box$^b$ relative to each other ""paper-chain"" columns
+made of vertex-sharing CuIO4 and CuIIO4 planar units. The overall pattern of
+the copper ions is that of a three-dimensional Shastry-Sutherland network. At
+high temperatures, the magnetic susceptibility follows the Curie-Weiss law with
+positive Weiss temperature indicating strong predominance of ferromagnetic
+coupling. At low temperatures, however, this compound reaches the
+antiferromagnetically ordered state and experiences non-trivial succession of
+two spin-flop and two spin-flip transitions reaching full saturation in modest
+magnetic fields. Here we show that the possible ground state in Ba3Cu3In4O12
+can be three-dimensional orthogonal arrangement of the Cu2+ (S = 1/2) magnetic
+moments forming three virtually independent antiferromagnetic subsystems. In
+this arrangement, favored by anisotropic exchange interactions, the quantum
+fluctuations provide the coupling between three mutually orthogonal magnetic
+subsystems resulting in an impressive ""order by disorder"" effect.",1111.1186v1
+2011-12-13,Magnetic Phase transitions in Plasmas and Transport Barriers,"A model of magnetic phase transitions in plasmas is presented: plasma blobs
+with pressure excess or defect are dia- or para-magnets and move radially under
+the influence of the background plasma magnetisation. It is found that magnetic
+phase separation could be the underlying mechanism of L to H transitions and
+drive transport barrier formation. Magnetic phase separation and associated
+pedestal build up, as described here, can be explained by the well known
+interchange mechanism, now reinterpreted as a magnetisation interchange which
+remains relevant even when stable or saturated. A testable necessary criterion
+for the L to H transition is presented.",1112.2977v4
+2012-03-30,A correlator product state study of molecular magnetism in the giant Keplerate Mo72Fe30,"We have studied the properties of the giant Keplerate molecular magnet
+Mo72Fe30, as a function of applied magnetic field, using the correlator product
+state (CPS) tensor network ansatz. The magnet is modeled with an S = 5/2
+antiferromagnetic Heisenberg Hamiltonian on the 30-site icosidodecahedron
+lattice, a model for which exact diagonalization is infeasible. The CPS ansatz
+produces significant improvements in variational energies relative to previous
+studies using the density matrix renormalization group, a result of its
+superior ability to handle strong correlation in two dimensional spin systems.
+The CPS results reaffirm that the ground state energies adhere qualitatively to
+the parabolic progression of the rotational band model (RBM), but show
+important deviations near 1/3 of the saturation field. These deviations predict
+anomalous behavior in the differential magnetization and heat capacity that
+cannot be explained by the RBM alone. Finally, we show that these energetic
+deviations originate from a qualitative change in the ground state that
+resembles a finite size analogue of a phase transition.",1203.6883v1
+2012-04-04,Martensite-like transition and spin-glass behavior in nanocrystalline Pr0.5Ca0.5MnO3,"We report on isothermal pulsed (20 ms) field magnetization, temperature
+dependent AC - susceptibility, and the static low magnetic field measurements
+carried out on 10 nm sized Pr0.5Ca0.5MnO3 nanoparticles (PCMO10). The
+saturation field for the magnetization of PCMO10 (~ 250 kOe) is found to be
+reduced in comparison with that of bulk PCMO (~300 kOe). With increasing
+temperature, the critical magnetic field required to 'melt' the residual
+charge-ordered phase decays exponentially while the field transition range
+broadens, which is indicative of a Martensite-like transition. The AC -
+susceptibility data indicate the presence of a frequency-dependent freezing
+temperature, satisfying the conventional Vogel-Fulcher and power laws, pointing
+to the existence of a spin-glass-like disordered magnetic phase. The present
+results lead to a better understanding of manganite physics and might prove
+helpful for practical applications.",1204.1014v1
+2012-04-08,Two successive field-induced spin-flop transitions in single-crystalline CaCo$_{2}$As$_{2}$,"CaCo$_{2}$As$_{2}$, a ThCr$_{2}$Si$_{2}$-structure compound, undergoes an
+antiferromagnetic transition at \emph{T$_{N}$}=76K with the magnetic moments
+being aligned parallel to the \emph{c} axis. Electronic transport measurement
+reveals that the coupling between conducting carriers and magnetic order in
+CaCo$_{2}$As$_{2}$ is much weaker comparing to the parent compounds of iron
+pnictide. Applying magnetic field along \emph{c} axis induces two successive
+spin-flop transitions in its magnetic state. The magnetization saturation
+behaviors with \emph{\textbf{H}$\parallel$c} and \emph{\textbf{H}$\parallel$ab}
+at 10K indicate that the antiferromagnetic coupling along \emph{c} direction is
+very weak. The interlayer antiferromagntic coupling constant \emph{J$_{c}$} is
+estimated to be about 2 meV.",1204.1736v1
+2012-04-09,Evidence for spin-flip scattering and local moments in dilute fluorinated graphene,"The issue of whether local magnetic moments can be formed by introducing
+adatoms into graphene is of intense research interest because it opens the
+window to fundamental studies of magnetism in graphene, as well as of its
+potential spintronics applications. To investigate this question we measure, by
+exploiting the well-established weak localization physics, the phase coherence
+length L_phi in dilute fluorinated graphene. L_phi reveals an unusual
+saturation below ~ 10 K, which cannot be explained by non-magnetic origins. The
+corresponding phase breaking rate increases with decreasing carrier density and
+increases with increasing fluorine density. These results provide strong
+evidence for spin-flip scattering and points to the existence of adatom-induced
+local magnetic moment in fluorinated graphene. Our results will stimulate
+further investigations of magnetism and spintronics applications in
+adatom-engineered graphene.",1204.1775v1
+2012-05-17,Simulations of Magnetic Field Generation in Unmagnetized Plasmas via Beat Wave Current Drive,"This work describes the scientific basis and associated simulation results
+for the magnetization of an unmagnetized plasma via beat wave current drive.
+Two-dimensional electromagnetic particle-in-cell simulations have been
+performed for a variety of angles between the injected waves to demonstrate
+beat wave generation in agreement with theoretical predictions of the beat-wave
+wave vector and saturation time, revealing new 2D effects. The simulations
+clearly demonstrate electron acceleration by the beat waves and resultant
+current drive and magnetic field generation. The basic process depends entirely
+on the angle between the parent waves and the ratio of the beat-wave phase
+velocity to the electron thermal velocity. The wave to magnetic energy
+conversion efficiency of the cases examined is as high as 0.2%. The technique
+could enable novel plasma experiments in which the use of magnetic coils is
+infeasible.",1205.3920v2
+2012-09-01,Incomplete devil's staircase in the magnetization curve of SrCu2(BO3)2,"We report on NMR and torque measurements on the frustrated
+quasi-two-dimensional spin-dimer system SrCu2(BO3)2 in magnetic fields up to 34
+T that reveal a sequence of magnetization plateaus at 1/8, 2/15, 1/6, and 1/4
+of the saturation and two incommensurate phases below and above the 1/6
+plateau. The magnetic structures determined by NMR involve a stripe order of
+triplets in all plateaus, suggesting that the incommensurate phases originate
+from proliferation of domain walls. We propose that the magnetization process
+of SrCu2(BO3)2 is best described as an incomplete devil's staircase.",1209.0069v2
+2012-09-05,Magnetic Field Amplification Associated with the Richtmyer-Meshkov Instability,"The amplification of a magnetic field due to the Richtmyer-Meshkov
+instability (RMI) is investigated by two-dimensional MHD simulations.
+Single-mode analysis is adopted to reveal definite relation between the
+nonlinear evolution of RMI and the field enhancement. It is found that an
+ambient magnetic field is stretched by fluid motions associated with the RMI,
+and the strength is amplified significantly by more than two orders of
+magnitude. The saturation level of the field is determined by a balance between
+the amplified magnetic pressure and the thermal pressure after shock passage.
+This effective amplification can be achieved in a wide range of the conditions
+for the RMI such as the Mach number of an incident shock and the density ratio
+at a contact discontinuity. The results suggest that the RMI could be a robust
+mechanism of the amplification of interstellar magnetic fields and cause the
+origin of localized strong fields observed at the shock of supernova remnants.",1209.0961v1
+2012-09-25,Magnetization of 2.6T in gadolinium thin films,"There is renewed interest in rare-earth elements and gadolinium in particular
+for a range of studies in coupling physics and applications. However, it is
+still apparent that synthesis impacts understanding of the intrinsic magnetic
+properties of thin gadolinium films, particularly for thicknesses of
+topicality. We report studies on 50nm thick nanogranular polycrystalline
+gadolinium thin films on SiO2 wafers that demonstrate single-crystal like
+behavior. The maximum in-plane saturation magnetization at 4K was found to be
+4{\pi}MS4K = (2.61{\pm}0.26)T with a coercivity of HC4K = (160{\pm}5)Oe. A
+maximum Curie point of TC = (293{\pm}2)K was measured via zero-field-cooled -
+field- cooled magnetization measurements in close agreement with values
+reported in bulk single crystals. Our measurements revealed magnetic
+transitions at T1 = (12{\pm}2)K (as deposited samples) and T2 = (22{\pm}2)K
+(depositions on heated substrates) possibly arising from the interaction of
+paramagnetic fcc grains with their ferromagnetic hcp counterparts.",1209.5617v1
+2012-11-05,Exact asymptotic behavior of magnetic stripe domain arrays,"The classical problem of magnetic stripe domain behavior in films and plates
+with uniaxial magnetic anisotropy is treated. Exact analytical results are
+derived for the stripe domain widths as function of applied perpendicular
+field, $H$, in the regime where the domain period becomes large. The stripe
+period diverges as $(H_c-H)^{-1/2}$, where $H_c$ is the critical (infinite
+period) field, an exact result confirming a previous conjecture. The
+magnetization approaches saturation as $(H_c-H)^{1/2}$, a behavior which
+compares excellently with experimental data obtained for a $4 \mu$m thick
+ferrite garnet film. The exact analytical solution provides a new basis for
+precise characterization of uniaxial magnetic films and plates, illustrated by
+a simple way to measure the domain wall energy. The mathematical approach is
+applicable for similar analysis of a wide class of systems with competing
+interactions where a stripe domain phase is formed.",1211.1366v1
+2012-12-03,Successive magnetic phase transitions and multiferroicity in Spin-1 triangular lattice antiferromagnet Ba$_3$NiNb$_2$O$_9$,"We report the magnetic and electric properties of Ba$_3$NiNb$_2$O$_9$, which
+is a quasi-two-dimensional spin-1 triangular lattice antiferromagnet (TLAF)
+with trigonal structure. At low $T$ and with increasing magnetic field, the
+system evolves from a 120 degree magnetic ordering phase (A phase) to an
+up-up-down ($uud$) phase (B phase) with a change of slope at 1/3 of the
+saturation magnetization, and then to an ""oblique"" phase (C phase).
+Accordingly, the ferroelectricity switches on at each phase boundary with
+appearance of spontaneous polarization. Therefore, Ba$_3$NiNb$_2$O$_9$ is a
+unique TLAF exhibiting both $uud$ phase and multiferroicity.",1212.0485v1
+2012-12-04,Spinodal Decomposition of Magnetic Ions in Eu-Codoped Ge/1-x/Cr/x/Te,"We present the experimental evidence for the presence of spinodal
+decomposition of the magnetic ions in the Ge/1-x-y/Cr/x/Eu/y/Te samples with
+chemical composition varying in the range of 0.015 < x < 0.057 and 0.003 < y <
+0.042. The ferromagnetic transition at temperatures 50 < T < 57 K was observed,
+independent of the chemical composition. The long-range carrier mediated
+itinerant magnetic interactions seem to be responsible for the observed
+ferromagnetic order. The magnetic irreversibility with coercive field H/C/ =
+5?63 mT and the saturation magnetization M/S/ <? 2?6 emu/g are found to
+strongly depend on the chemical composition of the alloy.",1212.0666v1
+2012-12-11,Exact ground state of the Shastry-Sutherland lattice with classical Heisenberg spins,"An exact analytical solution of the ground state problem of the isotropic
+classical Heisenberg model on the Shastry-Sutherland lattice in external
+magnetic field $H$ is found for arbitrary ratio of diagonal to edge exchange
+constants $J_2/J_1$. The phase diagram of this model in the ($J_2/J_1, H/J_1$)
+plane is presented. It includes spin-flop, spin-flip and umbrella phases. The
+magnetization curves are found to be linear until saturation. It is shown
+numerically that the inclusion of the easy-axis anisotropy into the model leads
+to the appearance of the 1/3 magnetization plateau, corresponding to the
+collinear up-up-down spin structure. This explains the appearance of the 1/3
+magnetization plateau in rare earth tetraborides RB$_4$. In particular,
+magnetization curve of the compound HoB$_4$ is explained.",1212.2320v2
+2012-12-13,Material Targets for Scaling All Spin Logic,"All-spin logic devices are promising candidates to augment and complement
+beyond-CMOS integrated circuit computing due to non-volatility, ultra-low
+operating voltages, higher logical efficiency, and high density integration.
+However, the path to reach lower energy-delay product performance compared to
+CMOS transistors currently is not clear. We show that scaling and engineering
+the nanoscale magnetic materials and interfaces is the key to realizing spin
+logic devices that can surpass energy-delay performance of CMOS transistors.
+With validated stochastic nano-magnetic and vector spin transport numerical
+models, we derive the target material and interface properties for the
+nanomagnets and channels. We identified promising new directions for material
+engineering/discovery focusing on systematic scaling of magnetic anisotropy
+(Hk) with saturation magnetization (Ms), use of perpendicular magnetic
+anisotropy, and interface spin mixing conductance of ferromagnet/spin channel
+interface (Gmix). We provide systematic targets for scaling spin logic
+energy-delay product toward a 2 aJ.ns energy-delay product, comprehending the
+stochastic noise for nanomagnets.",1212.3362v1
+2012-12-25,"Magnetic properties, Lyapunov exponent and superstability of the spin-1/2 Ising-Heisenberg model on diamond chain","The exactly solvable spin-1/2 Ising-Heisenberg model on diamond chain has
+been considered. We have found the exact results for the magnetization by using
+recursion relation method. The existence of the magnetization plateau has been
+observed at one third of the saturation magnetization in the antiferromagnetic
+case. Some ground-state properties of the model are examined. At low
+temperatures, the system has two ferrimagnetic (FRI1 and FRI2) phases and one
+paramagnetic (PRM) phase. Lyapunov exponents for the various values of the
+exchange parameters and temperatures have been analyzed. It have also been
+shown that the maximal Lyapunov exponent exhibits plateau. Lyapunov exponents
+exhibit different behavior for two ferrimagnetic phases. We have found the
+existence of the supercritical point for the multi-dimensional rational mapping
+of the spin-1/2 Ising-Heisenberg model on diamond chain for the first time at
+absence of the external magnetic field and $T \rightarrow 0$ in the
+antiferromagnetic case.",1212.6008v1
+2012-12-31,Effects of lateral device size and material properties on the ferromagnetic resonance response of spinwave eigen-modes in magnetic devices,"We analyze the effects of lateral device size and magnetic material
+parameters on the ferromagnetic resonance (FMR) response. Results presented are
+directly relevant to widely used FMR experimental techniques for extracting
+magnetic parameters from thin films, the results of which are often assumed to
+carry over to corresponding nanometer-sized patterned devices. We show that
+there can be significant variation in the FMR response with device size, and
+that the extent of the variation depends on the magnetic material properties.
+This explains, for example, why different experiments along these lines have
+yielded different size-dependent trends from damping measurements. Observed
+trends with increasing size and different material parameters are explained
+through the evolution of three distinct eigen-modes, demonstrating the
+respective roles of demagnetization and exchange. It is also shown that there
+is a crossover of dominant eigen-modes in the response signal, accompanied by
+conjugating edge-type modes, leading to evident effects in measured linewidth
+and damping. Among the sizes considered, in higher saturation magnetization, we
+observe as much as a 40% increase in apparent damping, due solely to device
+size variation.",1212.6835v1
+2013-01-28,Structural and magnetic properties of Pr-alloyed MnBi nanostructures,"The structural and magnetic properties of Pr-alloyed MnBi (short MnBi-Pr)
+nanostructures with a range of Pr concentrations have been investigated. The
+nanostructures include thin films having Pr concentrations 0, 2, 3, 5 and 9
+atomic percent and melt-spun ribbons having Pr concentrations 0, 2, 4 and 6
+percent respectively. Addition of Pr into the MnBi lattice has produced a
+significant change in the magnetic properties of these nanostructures including
+an increase in coercivity and structural phase transition temperature, and a
+decrease in saturation magnetization and anisotropy energy. The highest value
+of coercivity measured in the films is 23 kOe and in the ribbons is 5.6 kOe.
+The observed magnetic properties are explained as the consequences of competing
+ferromagnetic and antiferromagnetic interactions.",1301.6782v1
+2013-02-08,Magnetic flux loop in high-energy heavy-ion collisions,"We consider the expectation value of a magnetic flux loop in the immediate
+forward light cone of collisions of heavy nuclei at high energies. Such
+collisions are characterized by a non-linear scale Q_s where color fields
+become strong. We find that loops of area greater than ~2/Q_s^2 exhibit area
+law behavior, which determines the scale of elementary flux excitations
+(""vortices""). We also estimate the magnetic string tension, sigma_M = 0.12
+Q_s^2. By the time t ~ 1/Q_s even small loops satisfy an area law. We describe
+corrections to the propagator of semi-hard gluons at very early times in the
+background of fluctuating magnetic fields.",1302.2064v4
+2013-02-27,Magnetic Hyperthermia with Fe3O4 nanoparticles: the Influence of Particle Size on Energy Absorption,"We have studied the magnetic and power absorption properties of a series of
+magnetic nanoparticles (MNPs) of Fe3O4 with average sizes <d> ranging from 3 to
+26 nm. Heating experiments as a function of particle size revealed a strong
+increase in the specific power absorption (SPA) values for particles with <d> =
+25-30 nm. On the other side saturation magnetization MS values of these MNPs
+remain essentially constant for particles with <d> above 10 nm, suggesting that
+the absorption mechanism is not determined by MS. The largest SPA value
+obtained was 130 W/g, corresponding to a bimodal particle distribution with
+average size values of 17 and 26 nm.",1302.6912v1
+2013-03-05,"Angle-Dependent Spin-Wave Resonance Spectroscopy of (Ga,Mn)As Films","A modeling approach for standing spin-wave resonances based on a
+finite-difference formulation of the Landau-Lifshitz-Gilbert equation is
+presented. In contrast to a previous study [Bihler et al., Phys. Rev. B 79,
+045205 (2009)], this formalism accounts for elliptical magnetization precession
+and magnetic properties arbitrarily varying across the layer thickness,
+including the magnetic anisotropy parameters, the exchange stiffness, the
+Gilbert damping, and the saturation magnetization. To demonstrate the
+usefulness of our modeling approach, we experimentally study a set of (Ga,Mn)As
+samples grown by low-temperature molecular-beam epitaxy by means of
+electrochemical capacitance-voltage measurements and angle-dependent standing
+spin-wave resonance spectroscopy. By applying our modeling approach, the angle
+dependence of the spin-wave resonance data can be reproduced in a simulation
+with one set of simulation parameters for all external field orientations. We
+find that the approximately linear gradient in the out-of-plane magnetic
+anisotropy is related to a linear gradient in the hole concentrations of the
+samples.",1303.1192v1
+2013-10-02,Coronal influence on dynamos,"We report on turbulent dynamo simulations in a spherical wedge with an outer
+coronal layer. We apply a two-layer model where the lower layer represents the
+convection zone and the upper layer the solar corona. This setup is used to
+study the coronal influence on the dynamo action beneath the surface.
+Increasing the radial coronal extent gradually to three times the solar radius
+and changing the magnetic Reynolds number, we find that dynamo action benefits
+from the additional coronal extent in terms of higher magnetic energy in the
+saturated stage. The flux of magnetic helicity can play an important role in
+this context.",1310.0787v1
+2013-11-05,Chiral skyrmions in cubic helimagnet films: the role of uniaxial anisotropy,"This paper reports on magnetometry and magnetoresistance measurements of MnSi
+epilayers performed in out-of-plane magnetic fields. We present a theoretical
+analysis of the chiral modulations that arise in confined cubic helimagnets
+where the uniaxial anisotropy axis and magnetic field are both out-of-plane. In
+contrast to in-plane field measurements (Wilson et al., Phys. Rev. B 86, 144420
+(2012)), the hard-axis uniaxial anisotropy in MnSi/Si(111) increases the energy
+of (111)-oriented skyrmions and in-plane helicoids relative to the cone phase,
+and makes the cone phase the only stable magnetic texture below the saturation
+field. While induced uniaxial anisotropy is important in stabilizing skyrmion
+lattices and helicoids in other confined cubic helimagnets, the particular
+anisotropy in MnSi/Si(111) entirely suppresses these states in an out-of-plane
+magnetic field. However, it is predicted that isolated skyrmions with enlarged
+sizes exist in MnSi/Si(111) epilayers in a broad range of out-of-plane magnetic
+fields.",1311.1191v2
+2013-11-26,Transition from insulating to metallic phase induced by in-plane magnetic field in HgTe quantum wells,"We report transport measurements in HgTe-based quantum wells with well width
+of 8 nm, corresponding to quantum spin Hall state, subject to in-plane magnetic
+field. In the absence of the magnetic field the local and nonlocal resistances
+behave very similar, which confirms the edge state transport in our system. In
+the magnetic field, we observe a monotonic decrease of the resistance with
+saturation of local resistance, while nonlocal resistance disappears
+completely, independent of the gate voltage. We believe that these evidences of
+metallic behavior indicate a transition to a gapless two-dimensional phase,
+according to theoretical predictions. The influence of disorder on resistivity
+properties of HgTe quantum wells under in-plane magnetic field is discussed.",1311.6775v1
+2013-12-12,Exact results for a generalized spin-1/2 Ising-Heisenberg diamond chain with the second-neighbor interaction between nodal spins,"The ground state and thermodynamics of a generalized spin-1/2
+Ising-Heisenberg diamond chain with the second-neighbor interaction between
+nodal spins are calculated exactly using the mapping method based on the
+decoration-iteration transformation. Rigorous results for the magnetization,
+susceptibility, and heat capacity are investigated in dependence on temperature
+and magnetic field for the frustrated diamond spin chain with the
+antiferromagnetic Ising and Heisenberg interactions. It is demonstrated that
+the second-neighbor interaction between nodal spins gives rise to a greater
+diversity of low-temperature magnetization curves, which may include an
+intermediate plateau at two-third of the saturation magnetization related to
+the classical ferrimagnetic (up-up-up-down-up-up-...) ground state with
+translationally broken symmetry besides an intermediate one-third magnetization
+plateau reflecting the translationally invariant quantum ferrimagnetic
+(monomer-dimer) spin arrangement.",1312.3439v1
+2014-02-11,Thermodynamic Properties of the Quantum Spin Liquid Candidate ZnCu$_{3}$(OH)$_{6}$Cl$_{2}$ in High Magnetic Fields,"We report measurements of the specific heat and magnetization of single
+crystal samples of the spin-1/2 kagome compound ZnCu$_{3}$(OH)$_{6}$Cl$_{2}$
+(herbertsmithite), a promising quantum spin-liquid candidate, in high magnetic
+fields and at low temperatures. The magnetization was measured up to $\mu_{0}H$
+= 55 T at $T$ = 0.4 K, showing a saturation of the weakly interacting impurity
+moments in fields above $\sim10$ T. The specific heat was measured down to $T <
+0.4$ K in magnetic fields up to 18 T, revealing $T$-linear and $T$-squared
+contributions. The $T$-linear contribution is surprisingly large and indicates
+the presence of gapless excitations in large applied fields. These results
+further highlight the unusual excitation spectrum of the spin liquid ground
+state of herbertsmithite.",1402.2693v1
+2014-03-26,Manipulation of the magnetic order parameter and the metal-insulator-transition of a manganite thin film with applied elastic stress,"We measured the temperature dependence of the saturation magnetization (Ms)
+of a (La1-xPrx)1-yCayMnO3 (x ~ 0.60, y ~ 0.33) film as a function of applied
+bending stress. Stress producing a compressive strain of -0.01% along the
+magnetic easy axis increased the Curie temperature by ~6 K and the
+metal-insulator-transition by ~4 K. Regardless of whether or not stress is
+applied to the film, magnetic ordering occurs at temperatures significantly
+higher than the metal-insulator-transition temperature. The magnetization of
+the sample at the temperature of the metal-insulator-transition is
+approximately the site percolation threshold for a two-dimensional spin
+lattice.",1403.6755v1
+2014-04-08,Almost Perfect Frustration in the Dimer Magnet Ba$_2$CoSi$_2$O$_6$Cl$_2$,"We determined the crystal structure of Ba$_2$CoSi$_2$O$_6$Cl$_2$, which was
+synthesized in this work, and investigated its quantum magnetic properties
+using single crystals. This compound should be described as a two-dimensionally
+coupled spin-1/2 XY-like spin dimer system. Ba$_2$CoSi$_2$O$_6$Cl$_2$ exhibits
+a stepwise magnetization process with a plateau at half of the saturation
+magnetization, irrespective of the field direction, although all the Co$^{2+}$
+sites are equivalent. This indicates that spin triplets are localized owing to
+the almost perfect frustration of interdimer exchange interactions. Thus, the
+spin states for the zero and 1/2 magnetization-plateau states are almost
+exactly given by the simple product of singlet dimers and the alternate product
+of singlet and triplet dimers, respectively.",1404.2033v2
+2014-05-03,Theory of field-induced quantum phase transition in spin dimer system Ba$_3$Cr$_2$O$_8$,"Motivated by recent experiments on Ba$_3$Cr$_2$O$_8$, we propose a theory
+describing low-temperature properties in magnetic field $h$ of dimer
+spin-$\frac12$ systems on a stacked triangular lattice with spatially
+anisotropic exchange interactions. Considering the interdimer interaction as a
+perturbation we derive in the second order the elementary excitations (triplon)
+spectrum and the effective interaction between triplons at the quantum critical
+point $h=h_c$ separating the paramagnetic phase ($h<h_c$) and a magnetically
+ordered one ($h_c<h<h_s$, where $h_s$ is the saturation field). Expressions are
+derived for $h_c(T)$ and the staggered magnetization $M_\perp(h)$ at $h$ close
+to $h_c$. We apply the theory to Ba$_3$Cr$_2$O$_8$ and determine exchange
+constants of the model by fitting the triplon spectrum obtained experimentally.
+It is demonstrated that in accordance with experimental data the system follows
+the 3D BEC scenario at $T<1$ K only due to a pronounced anisotropy of the
+spectrum near its minimum. Our expressions for $h_s$, $h_c(T)$ and $M_\perp(h)$
+fit well available experimental data.",1405.0564v1
+2014-10-27,Hysteretic Magnetotransport in SmB6 at Low Magnetic Fields,"Utilizing Corbino disc structures, we have examined the magnetic field
+response of resistivity for the surface states of SmB6 on different crystalline
+surfaces at low temperatures. Our results reveal a hysteretic behavior whose
+magnitude depends on the magnetic field sweep rate and temperature. Although
+this feature becomes smaller when the field sweep is slower, a complete
+elimination or saturation is not observed in our slowest sweep-rate
+measurements, which is much slower than a typical magnetotransport trace. These
+observations cannot be explained by quantum interference corrections such as
+weak anti-localization. Instead, they are consistent with behaviors of glassy
+surface magnetic ordering, whose magnetic origin is most likely from samarium
+oxide (Sm2O3) forming on the surface during exposure to ambient conditions.",1410.7430v1
+2014-11-27,"Magnetism of Hexagonal Mn1.5X0.5Sn (X = Cr, Mn, Fe, Co) Nanomaterials","Mn1.5X0.5Sn (X = Cr, Mn, Fe, Co) nanomaterials in the hexagonal Ni2In-type
+crystal structure have been prepared using arc-melting and melt spinning. All
+the rapidly quenched Mn1.5X0.5Sn alloys show moderate saturation magnetizations
+with the highest value of 458 emu/cm3 for Mn1.5Fe0.5Sn, but their Curie
+temperatures are less than 300 K. All samples except the Cr containing one show
+spin-glass-like behavior at low temperature. The magnetic anisotropy constants
+calculated from the high-field magnetization curves at 100 K are on the order
+of 1 Merg/cm3. The vacuum annealing of the ribbons at 550 oC significantly
+improved their magnetic properties with the Curie temperature increasing from
+206 K to 273 K for Mn1.5Fe0.5Sn.",1411.7689v1
+2014-12-09,Low-temperature ordered phases of the spin-$\frac{1}{2}$ XXZ chain system Cs$_2$CoCl$_4$,"In this study the magnetic order of the spin-1/2 XXZ chain system
+Cs$_2$CoCl$_4$ in a temperature range from 50 mK to 0.5 K and in applied
+magnetic fields up to 3.5 T is investigated by high-resolution measurements of
+the thermal expansion and the specific heat. Applying magnetic fields along a
+or c suppresses $T_\textrm{N}$ completely at about 2.1 T. In addition, we find
+an adjacent intermediate phase before the magnetization saturates close to 2.5
+T. For magnetic fields applied along b, a surprisingly rich phase diagram
+arises. Two additional transitions are observed at critical fields $\mu_0
+H_{SF1}\simeq 0.25$ T and $\mu_0 H_{SF2}\simeq 0.7$ T, which we propose to
+arise from a two-stage spin-flop transition.",1412.2988v1
+2014-12-17,Collinear order in a frustrated three-dimensional spin-$\frac12$ antiferromagnet Li$_2$CuW$_2$O$_8$,"Magnetic frustration in three dimensions (3D) manifests itself in the
+spin-$\frac12$ insulator Li$_2$CuW$_2$O$_8$. Density-functional band-structure
+calculations reveal a peculiar spin lattice built of triangular planes with
+frustrated interplane couplings. The saturation field of 29 T contrasts with
+the susceptibility maximum at 8.5 K and a relatively low N\'eel temperature
+$T_N\simeq 3.9$ K. Magnetic order below $T_N$ is collinear with the propagation
+vector $(0,\frac12,0)$ and an ordered moment of 0.65(4) $\mu_B$ according to
+neutron diffraction data. This reduced ordered moment together with the low
+maximum of the magnetic specific heat ($C^{\max}/R\simeq 0.35$) pinpoint strong
+magnetic frustration in 3D. Collinear magnetic order suggests that quantum
+fluctuations play crucial role in this system, where a non-collinear spiral
+state would be stabilized classically.",1412.5578v2
+2015-02-16,"Giant magnetocaloric effect, magnetization plateaux and jumps of the regular Ising polyhedra","Magnetization process and adiabatic demagnetization of the antiferromagnetic
+Ising spin clusters with the shape of regular polyhedra (Platonic solids) are
+exactly examined within the framework of a simple graph-theoretical approach.
+While the Ising cube as the only unfrustrated (bipartite) spin cluster shows
+just one trivial plateau at zero magnetization, the other regular Ising
+polyhedra (tetrahedron, octahedron, icosahedron and dodecahedron) additionally
+display either one or two intermediate plateaux at fractional values of the
+saturation magnetization. The nature of highly degenerate ground states
+emergent at intermediate plateaux owing to a geometric frustration is
+clarified. It is evidenced that the regular Ising polyhedra exhibit a giant
+magnetocaloric effect in a vicinity of magnetization jumps, whereas the Ising
+octahedron and dodecahedron belong to the most prominent geometrically
+frustrated spin clusters that enable an efficient low-temperature refrigeration
+by the process of adiabatic demagnetization.",1502.04449v1
+2015-02-27,Accurate calculation of the transverse anisotropy in perpendicularly magnetized multilayers,"The transverse anisotropy constant and the related D\""oring mass density are
+key parameters of the one-dimensional model to describe the motion of magnetic
+domain walls. So far, no general framework is available to determine these
+quantities from static characterizations such as magnetometry measurements.
+Here, we derive a universal analytical expression to calculate the transverse
+anisotropy constant for the important class of perpendicular magnetic
+multilayers. All the required input parameters of the model, such as the number
+of repeats, the thickness of a single magnetic layer, and the layer
+periodicity, as well as the effective perpendicular anisotropy, the saturation
+magnetization, and the static domain wall width are accessible by static sample
+characterizations. We apply our model to a widely used multilayer system and
+find that the effective transverse anisotropy constant is a factor 7 different
+from the when using the conventional approximations, showing the importance of
+using our analysis scheme.",1502.07937v1
+2015-03-11,Investigation of Magnetic Domain Structure in Bi0.7Dy0.3FeO3 thin films integrated with ZnO film,"The magnetic domain structure of the multiferroic Bi1-xDyxFeO3 (BDFO)
+deposited on ZnO at the macroscopic level has been demonstrated in this paper.
+Magnetic properties are observed by saturated magnetic and ferroelectric
+hysteresis loops at room temperature. The coupling behaviour and magnetic
+transition are verified using Multimode Atomic Force Microscope by applying
+bias between sample and MFM tip. ZnO thin film of 300 nm was deposited by
+dielectric sputtering using a ZnO target on Si p-type conducting (.0001-0005
+{\Omega} cm) substrate. BDFO thin films of 300 nm were deposited on Si/ZnO
+using PLD (Pulsed laser deposition) technique. It is observed that BDFO thin
+films integrated with ZnO film shows the coexistence of ferromagnetic and
+ferroelectric ordering with significant coupling at room temperature.
+Integration of BDFO films with ZnO piezoelectric thin film shows the potential
+in MEMS applications as well as in Memory devices and strong history dependent
+systems.",1503.03237v1
+2015-06-20,Effect of Sintering Temperature on Structural and Magnetic Properties of Ni0.6Zn0.4Fe2O4 Ferrite: Synthesized from Nanocrystalline Powders,"The effect of sintering temperatures (Ts) on the structural and magnetic
+properties of Ni0.6Zn0.4Fe2O4 (NZFO) ferrites synthesized by conventional
+double sintering method has been reported. The samples are sintered at 1200,
+1250 and 1300 {\deg}C. The X-ray diffraction (XRD) analysis reveals the
+formation of a single phase cubic spinel structure of the sample. The magnetic
+parameters such as saturation magnetization, Ms; coercive field, Hc; remanent
+magnetization, Mr and Bohr magneton, {\mu}B are determined and well compared
+with reported values. The obtained values are found to be 71.94 emu/gm and 1.2
+Oe for Ms and Hc, respectively at Ts=1300 oC. Curie temperature (Tc) at various
+Ts has also been calculated. It is noteworthy to note that the sample with a
+very low Hc could be used in transformer core and inductor applications.",1506.06280v2
+2015-06-27,Do Magnetic Fields Destroy Black Hole Accretion Disk g-Modes?,"Diskoseismology, the theoretical study of normal mode oscillations in
+geometrically thin, optically thick accretion disks, is a strong candidate to
+explain some QPOs in the power spectra of many black hole X-ray binary systems.
+The existence of g-modes, presumably the most robust and visible of the modes,
+depends on general relativistic gravitational trapping in the hottest part of
+the disk. As the existence of the required cavity in the presence of magnetic
+fields has been put into doubt by theoretical calculations, we will explore in
+greater generality what the inclusion of magnetic fields has to say on the
+existence of g-modes. We use an analytical perturbative approach on the
+equations of MHD to assess the impact of such effects. Our main conclusion is
+that there appears to be no compelling reason to discard g-modes. In
+particular, the inclusion of a non-zero {\it radial} component of the magnetic
+field enables a broader scenario for cavity non-destruction, especially taking
+into account recent simulations' saturation values for the magnetic field.",1506.08314v1
+2015-09-02,Magnetization Jump in the Magnetization Process of the spin-1/2 Heisenberg Antiferromagnet on a Distorted Square-Kagome Lattice,"We study the magnetization process of the spin-$1/2$ Heisenberg
+antiferromagnet on a distorted square-kagome lattice by the
+numerical-diagonalization method. The magnetization jump at one-third of the
+height of the saturation is examined in detail; we find that the jump becomes
+larger when a small distortion is switched on and that it is accompanied by an
+abrupt change in lines along microscopic spin directions. Our finite-size
+results successfully confirm that the magnetization jump in a spin-isotropic
+system is a macroscopic jump that survives in the thermodynamic limit and that
+the changes in spin directions are common to a spin-flop phenomenon observed in
+spin-anisotropic systems.",1509.00587v1
+2015-10-16,Effect of monomer-monomer interactions on the phase diagrams of the S=1/2 distorted diamond type quantum spin chain,"By use of mainly the exact diagonalization and the level spectroscopy method,
+we investigate the ground-state phase diagrams of the $S=1/2$ distorted diamond
+type quantum spin chain with the monomer-monomer interactions and/or
+ferromagnetic interactions for the zero magnetic field case, as well as the
+$M=M_{\rm s}/3$ case and the $M=(2/3)M_{\rm s}$ case, where $M$ is the total
+magnetization and $M_{\rm s}$ is the saturation magnetization. The
+magnetization plateau at $M=M_{\rm s}/3$ vanishes in the region where the
+ferromagnetic interaction is rather strong. The monomer-monomer interaction
+remarkably stabilizes the magnetization plateau at $M=(2/3)M_{\rm s}$.",1510.04913v1
+2015-11-05,Perpendicular standing spin wave and magnetic anisotropic study on amorphous FeTaC films,"Magnetic anisotropy, spin wave (SW) excitation and exchange stiffness
+constant of amorphous FeTaC ($d$ = 20-200 nm) films were studied as a function
+of thickness using micro-strip ferromagnetic resonance (MS-FMR) technique. The
+MS-FMR spectra for in-plane applied magnetic field show the presence of uniform
+precessional mode ($n$ = 0) along with first perpendicular standing spin wave
+(PSSW) mode ($n$ = 1) especially for $d$ = 50, 100 and 200 nm films. The
+angular ($\varphi_{H}$) dependence of resonance field ($H_{r}$) and magnetic
+field dependence of resonance frequencies ($f_{r}$) in planar configuration for
+the uniform and PSSW modes were modeled successfully by using dispersion
+relation which arises from a combination of exchange and dipolar interactions.
+The relevant parameters such as saturation magnetization ($4\pi M_{S}$),
+uniaxial anisotropic constant ($K_{u}$), $g$-factor, and exchange stiffness
+constants ($A_{ex}$) are estimated for different FeTaC film thickness. $A_{ex}$
+is found to increase from 1.52(4)$\times$10$^{-7}$ to 5.0(5)$\times$10$^{-6}$
+erg/cm as the thickness of film increases from 50 to 200 nm, possibly due to
+surface pinning effect or significant inhomogeneity especially at higher
+thickness films.",1511.01722v2
+2015-11-24,Ferromagnetic Resonance of a YIG film in the Low Frequency Regime,"An improved method for characterizing the magnetic anisotropy of films with
+cubic symmetry is described and is applied to an yttrium iron garnet (111)
+film. Analysis of the FMR spectra performed both in-plane and out-of-plane from
+0.7 to 8 GHz yielded the magnetic anisotropy constants as well as the
+saturation magnetization. The field at which FMR is observed turns out to be
+quite sensitive to anisotropy constants (by more than a factor ten) in the low
+frequency (< 2 GHz) regime and when the orientation of the magnetic field is
+nearly normal to the sample plane; the restoring force on the magnetization
+arising from the magnetocrystalline anisotropy fields is then comparable to
+that from the external field, thereby allowing the anisotropy constants to be
+determined with greater accuracy. In this region, unusual dynamical behaviors
+are observed such as multiple resonances and a switching of FMR resonance with
+only a 1 degree change in field orientation at 0.7 GHz.",1511.07892v1
+2015-12-16,The generation of magnetic fields by the Biermann battery and the interplay with the Weibel instability,"An investigation of magnetic fields generated in an expanding bubble of
+plasma with misaligned temperature and density gradients (driving the Biermann
+battery mechanism) is performed. With gradient scales $L$, large-scale magnetic
+fields are generated by the Biermann battery mechanism with plasma $\beta \sim
+1$, as long as $L$ is comparable to the ion inertial length $d_i$. For larger
+system sizes, $L/d_e > 100$ (where $d_e$ is the electron inertial length), the
+Weibel instability generates magnetic fields of similar magnitude but with
+wavenumber $k d_e \sim 0.2$. In both cases, the growth and saturation of these
+fields have a weak dependence on mass ratio $m_i/m_e$, indicating electron
+mediated physics. A scan in system size is performed at $m_i/m_e = 2000$,
+showing agreement with previous results with $m_i/m_e = 25$. In addition, the
+instability found at large system sizes is quantitatively demonstrated to be
+the Weibel instability. Furthermore, magnetic and electric energy spectra at
+scales below the electron Larmor radius are found to exhibit power law behavior
+with spectral indices $-16/3$ and $-7/3$, respectively.",1512.05158v2
+2016-01-04,Influence of magnetic quantum confined Stark effect on the spin lifetime of indirect excitons,"We report on the unusual and counter-intuitive behaviour of spin lifetime of
+excitons in coupled semiconductor quantum wells (CQWs) in the presence of
+in-plane magnetic field. Instead of conventional acceleration of spin
+relaxation due to the Larmor precession of electron and hole spins we observe a
+strong increase of the spin relaxation time at low magnetic fields followed by
+saturation and decrease at higher fields. We argue that this non-monotonic spin
+relaxation dynamics is a fingerprint of the magnetic quantum confined Stark
+effect. In the presence of electric field along the CQW growth axis, an applied
+magnetic field efficiently suppresses the exciton spin coherence, due to
+inhomogeneous broadening of the $g$-factor distribution.",1601.00427v1
+2016-02-08,Hysteretic magnetoresistance and unconventional anomalous Hall effect in the frustrated magnet TmB_4,"We study TmB_4, a frustrated magnet on the Archimedean Shastry-Sutherland
+lattice, through magnetization and transport experiments. The lack of
+anisotropy in resistivity shows that TmB_4 is an electronically
+three-dimensional system. The magnetoresistance (MR) is hysteretic at
+low-temperature even though a corresponding hysteresis in magnetization is
+absent. The Hall resistivity shows unconventional anomalous Hall effect (AHE)
+and is linear above saturation despite a large MR. We propose that complex
+structures at magnetic domain walls may be responsible for the hysteretic MR
+and may also lead to the AHE.",1602.02679v2
+2016-04-21,Achieving sub-shot-noise sensing at finite temperatures,"We investigate sensing of magnetic fields using quantum spin chains at finite
+temperature and exploit quantum phase crossovers to improve metrological bounds
+on the estimation of the chain parameters. In particular, we analyze the $ XX $
+spin chain and show that the magnetic sensitivity of this system is dictated by
+its adiabatic magnetic susceptibility, which scales extensively (linearly) in
+the number of spins $ N $. Next, we introduce an iterative feedforward protocol
+that actively exploits features of quantum phase crossovers to enable
+super-extensive scaling of the magnetic sensitivity. Moreover, we provide
+experimentally realistic observables to saturate the quantum metrological
+bounds. Finally, we also address magnetic sensing in the Heisenberg $ XY $ spin
+chain.",1604.06400v2
+2016-04-28,"Magnetization Saturation Process in the Magnonic Anti-dot Structures Based on (Ga,Mn)As: A Magnetometric Study","Applicability of dilute magnetic semiconductors (DMS) in electronic devices
+relies upon the understanding and control of their magnetic anisotropy. This
+paper explores one of the ways in engineering magnetic anisotropy in epitaxial
+layers of DMS by forming them into magnonic structures. For this purpose the
+canonical ferromagnetic DMS, namely (Ga,Mn)As, is employed. The anti-dot
+systems based on (Ga,Mn)As layers of various thicknesses are fabricated with
+focused ion beam apparatus and studied by means of microscopy as well as
+magnetometry. The magnetometric data - collected along two nonequivalent
+in-plane crystallographic directions of (Ga,Mn)As: [110] and [1-10] - shows the
+effect of structuring on high-field magnetization process, whereas no
+significant change of the width of hysteresis loop in anti-dot samples is
+observed.",1604.08607v1
+2016-05-09,Self-heating effects of the surface oxidized FeCo nanoparticles colloid under alternating magnetic field,"To evaluate the self-heating effects of FeCo magnetic nanoparticles, the
+surface oxidized FeCo nanoparticles were synthesized by co-precipitation method
+with the reduction reaction without any post treatments. As-synthesized FeCo
+nanoparticles exhibited the mean diameter of about 39 nm with the oxidized
+shell thickness of about 4-5 nm. The saturation magnetization and coercivity
+were obtained 172 emu/g and 268 Oe at 300 K, respectively. The heat elevation
+of the FeCo magnetic colloid was measured under alternating magnetic fields of
+76, 102, and 127 Oe with selectable frequencies of 190, 250 and 355 kHz. The
+heat temperature increased up to about 45 oC from initial temperature of 24 oC
+under 127 Oe and 355 kHz, which the specific absorption exhibited about 35.7
+W/g.",1605.02806v1
+2016-05-25,Effect of further-neighbor interactions on the magnetization behaviors of the Ising model on a triangular lattice,"In this work, we study the magnetization behaviors of the classical Ising
+model on the triangular lattice using Monte Carlo simulations, and pay
+particular attention to the effect of further-neighbor interactions. Several
+fascinating spin states are identified to be stabilized in certain magnetic
+field regions, respectively, resulting in the magnetization plateaus at 2/3,
+5/7, 7/9 and 5/6 of the saturation magnetization MS, in addition to the well
+known plateaus at 0, 1/3 and 1/2 of MS. The stabilization of these interesting
+orders can be understood as the consequence of the competition between Zeeman
+energy and exchange energy.",1605.07794v1
+2016-06-30,Magnetic flux stabilizing thin accretion disks,"We calculate the minimal amount of large-scale poloidal magnetic field that
+has to thread the inner, radiation-over-gas pressure dominated region of a thin
+disk for its thermal stability. Such a net field amplifies the magnetization of
+the saturated turbulent state and makes it locally stable. For a $10 M_\odot$
+black hole the minimal magnetic flux is $10^{24}(\dot M/\dot M_{\rm
+Edd})^{20/21}\,\rm G\cdot cm^{2}$. This amount is compared with the amount of
+uniform magnetic flux that can be provided by the companion star -- estimated
+to be in the range $10^{22}-10^{24}\,\rm G\cdot cm^2$. If accretion rate is
+large enough, the companion is not able to provide the required amount and such
+a system, if still sub-Eddington, must be thermally unstable. The peculiar
+variability of GRS 1915+105, an X-ray binary with the exceptionally high BH
+mass and near-Eddington luminosity, may result from the shortage of large scale
+poloidal field of uniform polarity.",1606.09566v1
+2016-07-25,Particles trajectories in Weibel magnetic filaments with a flow-aligned magnetic field,"For a Weibel shock to form, two plasma shells have to collide and trigger the
+Weibel instability. At saturation, this instability generates in the
+overlapping region magnetic filaments with peak field $B_f$. In the absence of
+an external guiding magnetic field, these filaments can block the incoming
+flow, initiating the shock formation, if their size is larger than the Larmor
+radius of the incoming particles in the peak field. Here we show that this
+results still holds in the presence of an external magnetic field $B_0$,
+provided it is not too high. Yet, for $B_0 \gtrsim B_f/2$, the filaments become
+unable to stop any particle, regardless of its initially velocity.",1607.07442v1
+2016-09-29,Magnetotransport properties and evidence of topological insulating state in LaSbTe,"In this report, we present the magnetotransport and magnetization properties
+of LaSbTe single crystals. Magnetic field-induced turn-on behavior and
+low-temperature resistivity plateau have been observed. By adopting both
+metal-semiconductor crossover and Kohler scaling analysis, we have discussed
+the possible origin of the temperature and magnetic field dependence of
+resistivity. At 5 K and 9 T, a large, non-saturating transverse
+magnetoresistance (MR) $\sim$ 5$\times$10$^{3}$ \% has been obtained. The MR
+shows considerable anisotropy, when the magnetic field is applied along
+different crystallographic directions. The non-linear field dependence of the
+Hall resistivity confirms the presence of two types of charge carriers. From
+the semiclassical two-band fitting of Hall conductivity and longitudinal
+conductivity, very high carrier mobilities and almost equal electron and hole
+densities have been deduced, which result in large MR. The Fermi surface
+properties have been analyzed from de Haas-van Alphen oscillation. From the
+magnetization measurement, the signature of non-trivial surface state has been
+detected, which confirms that LaSbTe is a topological insulator, consistent
+with the earlier first-principles calculations.",1609.09397v3
+2016-12-14,"Exactly solved mixed spin-(1,1/2) Ising-Heisenberg distorted diamond chain","The mixed spin-(1,1/2) Ising-Heisenberg model on a distorted diamond chain
+with the spin-1 nodal atoms and the spin-1/2 interstitial atoms is exactly
+solved by the transfer-matrix method. An influence of the geometric spin
+frustration and the parallelogram distortion on the ground state,
+magnetization, susceptibility and specific heat of the mixed-spin
+Ising-Heisenberg distorted diamond chain are investigated in detail. It is
+demonstrated that the zero-temperature magnetization curve may involve
+intermediate plateaus just at zero and one-half of the saturation
+magnetization. The temperature dependence of the specific heat may have up to
+three distinct peaks at zero magnetic field and up to four distinct peaks at a
+non-zero magnetic field. The origin of multipeak thermal behavior of the
+specific heat is comprehensively studied.",1612.04841v1
+2017-03-28,Temperature dependent magnetic damping of yttrium iron garnet spheres,"We investigate the temperature dependent microwave absorption spectrum of an
+yttrium iron garnet sphere as a function of temperature (5 K to 300 K) and
+frequency (3 GHz to 43.5 GHz). At temperatures above 100 K, the magnetic
+resonance linewidth increases linearly with temperature and shows a
+Gilbert-like linear frequency dependence. At lower temperatures, the
+temperature dependence of the resonance linewidth at constant external magnetic
+fields exhibits a characteristic peak which coincides with a non-Gilbert-like
+frequency dependence. The complete temperature and frequency evolution of the
+linewidth can be modeled by the phenomenology of slowly relaxing rare-earth
+impurities and either the Kasuya-LeCraw mechanism or the scattering with
+optical magnons. Furthermore, we extract the temperature dependence of the
+saturation magnetization, the magnetic anisotropy and the g-factor.",1703.09444v2
+2017-05-26,Static and Dynamic Magnetic Properties of FeMn/Pt Multilayers,"Recently we have demonstrated the presence of spin-orbit toque in FeMn/Pt
+multilayers which, in combination with the anisotropy field, is able to rotate
+its magnetization consecutively from 0o to 360o without any external field.
+Here, we report on an investigation of static and dynamic magnetic properties
+of FeMn/Pt multilayers using combined techniques of magnetometry, ferromagnetic
+resonance, inverse spin Hall effect and spin Hall magnetoresistance
+measurements. The FeMn/Pt multilayer was found to exhibit ferromagnetic
+properties, and its temperature dependence of saturation magnetization can be
+fitted well using a phenomenological model by including a finite distribution
+in Curie temperature due to subtle thickness variations across the multilayer
+samples. The non-uniformity in static magnetic properties is also manifested in
+the ferromagnetic resonance spectra, which typically exhibit a broad resonance
+peak. A damping parameter of around 0.106 is derived from the frequency
+dependence of ferromagnetic resonance linewidth, which is comparable to the
+reported values for other types of Pt-based multilayers. Clear inverse spin
+Hall signals and spin Hall magnetoresistance have been observed in all samples
+below the Curie temperature, which corroborate the strong spin-orbit torque
+effect observed previously.",1705.09423v1
+2017-05-30,Heteroepitaxial growth of tetragonal Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ (0 $\leqslant$ x $\leqslant$ 1.2) Heusler films with perpendicular magnetic anisotropy,"This work reports on the structural and magnetic properties of
+Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ Heusler films with different Fe content x (0
+$\leqslant$ x $\leqslant$ 1.2). The films were deposited heteroepitaxially on
+MgO single crystal substrates, by magnetron sputtering.
+Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ films with the thickness of 35 nm were
+crystallized in tetragonal D0$_{22}$ structure with (001) preferred
+orientation. Tunable magnetic properties were achieved by changing the Fe
+content x. Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ thins films exhibit high uniaxial
+anisotropy Ku $\geqslant$ 1.4 MJ/m3, coercivity from 0.95 to 0.3 T and
+saturation magnetization from 290 to 570 kA/m. The film with
+Mn$_{1.6}$Fe$_{1.1}$Ga$_{1.3}$ composition shows high Ku of 1.47 MJ/m3 and
+energy product ${(BH)_{max}}$ of 37 kJ/m3, at room temperature. These findings
+demonstrate that Mn$_{2.7-x}$Fe$_{x}$Ga$_{1.3}$ films have promising properties
+for mid-range permanent magnet and spintronic applications.",1705.10668v1
+2017-10-03,d-zero Magnetism in Nanoporous Amorphous Alumina Membranes,"Nanoporous alumina membranes produced by mild or hard anodisation in oxalic
+acid at potentials ranging from 5 - 140 V have a controllable pore surface area
+of up to 200 times the membrane area. They exhibit a saturating magnetic
+response that is temperature-independent and almost anhysteretic below room
+temperature. The magnetism cannot be explained by the ~1 ppm of
+transition-metal impurities present in the membranes. The magnetic moment
+increases with the area of the open nanopores, reaching values of 0.6 Bohr
+magnetons per square nanometer for mild anodisation and 8 muB/nm2 for hard
+anodisation where the growth rate is faster. Crystallization of the membrane or
+chemical treatment with salicylic acid reduces the effect by up to 90 %. The
+magnetism is therefore associated with the open pore surfaces of the amorphous
+Al2O3, and it is independent of the orientation of the applied field with
+respect to the membrane surface. Possible explanations in terms of electrons
+associated with oxygen vacancies (F or F+ centres) are discussed and it is
+concluded that the effect is due to giant orbital paramagnetism rather than
+collective ferromagnetic spin order.",1710.01232v2
+2017-11-19,Room-temperature observation and current control of skyrmions in Pt/Co/Os/Pt thin films,"We report the observation of room-temperature magnetic skyrmions in
+Pt/Co/Os/Pt thin-film heterostructures and their response to electric currents.
+The magnetic properties are extremely sensitive to inserting thin Os layers
+between the Co-Pt interface resulting in reduced saturation magnetization,
+magnetic anisotropy and Curie temperature. The observed skyrmions exist in a
+narrow temperature, applied-field and layer-thickness range near the
+spin-reorientation transition from perpendicular to in-plane magnetic
+anisotropy. The skyrmions have an average diameter of 2.3{\mu}m and transport
+measurements demonstrate these features can be displaced with current densities
+as low as J = 2x10^4 A/cm^2 and display a skyrmion Hall effect.",1711.07101v1
+2017-11-26,Magnetization and Thermal Entanglement of the Spin-1 Ising-Heisenberg Polymer Chain,"We establish a solvable Heisenberg-Ising model on a spin-1 Ni-containing
+polymer chain, $[Ni (NN'-dmen) (\mu-N_3)_2]$, with $NN'-dmen$ being
+$NN'-dimethylethylenediamine$, that fully covers the interaction
+characteristics of the material and by which, we can characterize all the
+peculiar magnetic features of the polymer, which has been partly studied in
+experiment. By purely analytical calculations, we can see that the
+magnetization exhibits three plateaus at zero, mid, and 3/4 of the saturation
+value at low temperatures below 2 K. The corresponding featuring peaks of
+magnetic susceptibility are clearly shown. The model also displays plateaus in
+thermal entanglement that captures the one-to-one correspondence between
+thermal entanglement plateaus and those of the magnetization. The calculations
+are done by the transfer matrix technique.",1711.09350v1
+2018-04-18,Large perpendicular magnetic anisotropy in epitaxial Fe/MgAl2O4(001) heterostructures,"We investigated perpendicular magnetic anisotropy (PMA) and related
+properties of epitaxial Fe (0.7 nm)/MgAl2O4(001) heterostructures prepared by
+electron-beam evaporation. Using an optimized structure, we obtained a large
+PMA energy ~1 MJ/m3 at room temperature, comparable to that in
+ultrathin-Fe/MgO(001) heterostructures. Both the PMA energy and saturation
+magnetization show weak temperature dependence, ensuring wide working
+temperature in application. The effective magnetic damping constant of the 0.7
+nm Fe layer was ~0.02 using time-resolved magneto-optical Kerr effect. This
+study demonstrates capability of the Fe/MgAl2O4 heterostructure for
+perpendicular magnetic tunnel junctions, as well as a good agreement with
+theoretical predictions.",1804.06526v2
+2018-06-18,Magnetic properties of cobalt doped ZrO$_2$ nanoparticles: Evidence of Co segregation,"We synthesized pure and Co-doped (6.25 12.5 at.) ZrO$_2$ nanopowders in order
+to study their magnetic properties.We analyzed magnetic behavior as a function
+of the amount of Co and the oxygenation, which was controlled by low pressure
+thermal treatments. As prepared pure and Co-doped samples are diamagnetic and
+paramagnetic respectively. Ferromagnetism can be induced by performing low
+pressure thermal treatments, which becomes stronger as the dwell time of the
+thermal treatment is increased. This behavior can be reversed, recovering the
+initial diamagnetic or paramagnetic behavior, by performing reoxidizing thermal
+treatments. Also, a cumulative increase can be observed in the saturation of
+the magnetization with the number of low pressure thermal treatments performed.
+We believe that this phenomenon indicates that cobalt segregation induced by
+the thermal treatments is the responsible for the magnetic properties of the
+ZrO$_2$ Co system.",1806.06839v1
+2018-07-23,Magnetization curves and low-temperature thermodynamics of two spin-1/2 Heisenberg edge-shared tetrahedra,"A full energy spectrum, magnetization and susceptibility of a spin-1/2
+Heisenberg model on two edge-shared tetrahedra are exactly calculated by
+assuming two different coupling constants. It is shown that a ground state in
+zero field is either a singlet or a triplet state depending on a relative
+strength of both coupling constants. Low-temperature magnetization curves may
+exhibit three different sequences of intermediate plateaux at the following
+fractional values of the saturation magnetization: 1/3-2/3-1, 0-1/3-2/3-1 or
+0-2/3-1. The inverse susceptibility displays a marked temperature dependence
+significantly influenced by a character of the zero-field ground state. The
+obtained theoretical results are confronted with recent high-field
+magnetization data of the mineral crystal fedotovite K2Cu3(SO4)3.",1807.08821v1
+2018-09-25,Feasibility of imaging using Boltzmann polarization in nuclear Magnetic Resonance Force Microscopy,"We report on Magnetic Resonance Force Microscopy measurements of the
+Boltzmann polarization of the nuclear spins in copper by detecting the
+frequency shift of a soft cantilever. We use the time-dependent solution of the
+Bloch equations to derive a concise equation describing the effect of rf
+magnetic fields on both on- and off-resonant spins in high magnetic field
+gradients. We then apply this theory to saturation experiments performed on a
+100 nm thick layer of copper, where we use the higher modes of the cantilever
+as source of the rf field. We demonstrate a detection volume sensitivity of
+only (40 nm)$^3$, corresponding to about 1.6$\cdot 10^4$ polarized copper
+nuclear spins. We propose an experiment on protons where, with the appropriate
+technical improvements, frequency-shift based magnetic resonance imaging with a
+resolution better than (10 nm)$^3$ could be possible. Achieving this resolution
+would make imaging based on the Boltzmann polarization competitive with the
+more traditional stochastic spin-fluctuation based imaging, with the
+possibility to work at milliKelvin temperatures.",1809.09351v1
+2018-11-03,Ferromagnetic resonance in the complex permeability of an Fe$_3$O$_4$ nanosuspension at radio and microwave frequencies,"The complex permeability of an iron-oxide nanosuspension has been measured as
+a function of magnetic field strength at RF and microwave frequencies using a
+loop-gap resonator. The particles were suspended in water and had an 8-nm
+diameter Fe$_3$O$_4$ core that was coated by Dextran. The real part of the
+permeability increased sharply beyond a frequency-dependent threshold value of
+the static magnetic field before saturating. Just beyond this threshold field,
+there was a peak in the imaginary part of the permeability. The permeability
+measurements, which exhibited features associated with ferromagnetic resonance,
+were used to determine the dependence of the microwave absorption on static
+magnetic field strength. Using the absorption data, the $g$-factor of the
+nanosuspension was found to be $1.86\pm 0.07$.",1811.01168v1
+2018-12-04,Optical excitation of single- and multi-mode magnetization precession in Galfenol nanolayers,"We demonstrate a variety of precessional responses of the magnetization to
+ultrafast optical excitation in nanolayers of Galfenol (Fe,Ga), which is a
+ferromagnetic material with large saturation magnetization and enhanced
+magnetostriction. The particular properties of Galfenol, including cubic
+magnetic anisotropy and weak damping, allow us to detect up to 6 magnon modes
+in a 120-nm layer, and a single mode with effective damping ${\alpha}_{eff}$ =
+0.005 and frequency up to 100 GHz in a 4-nm layer. This is the highest
+frequency observed to date in time-resolved experiments with metallic
+ferromagnets. We predict that detection of magnetization precession approaching
+THz frequencies should be possible with Galfenol nanolayers.",1812.01237v1
+2018-12-17,Magnetized Current Filaments as a Source of Circularly Polarized Light,"We show that the Weibel or currente filamentation instability can lead to the
+emission of circularly polarized radiation. Using particle-in-cell (PIC)
+simulations and a radiation post-processing numerical algorithm, we demonstrate
+that the level of circular polarization increases with the initial plasma
+magnetization, saturating at ~13% when the magnetization, given by the ratio of
+magnetic energy density to the electron kinetic energy density, is larger than
+0.05. Furthermore, we show that this effect requires an ion-electron mass ratio
+greater than unity. These findings, which could also be tested in currently
+available laboratory conditions, show that the recent observation of circular
+polarization in gamma ray burst afterglows could be attributed to the presence
+of magnetized current filaments driven by the Weibel or the current
+filamentation instability.",1812.06889v1
+2019-01-30,Spin freezing and Field induced transition in (Tb1-xEux)2Ti2O7 : A Magnetic Property study,"The structural, magnetic and Raman effect have been investigated on
+(Tb1-xEux)2Ti2O7. From structural study it is clear that Eu substitutes the Tb
+in Tb2Ti2O7. Raman effect study indicates the existence of hardening due to
+phonon-phonon anharmonic interaction. From dc-magnetic measurement it is
+observed that in Eu rich samples contribution of dipolar interaction is
+significant. From ac magnetic measurement of (Tb1-xEux)2Ti2O7 a new single ion
+weak spin freezing ~ 33K at zero magnetic field is observed. On applying a
+field of 1T, all the compounds show a field induced transition (T*) which
+shifts towards higher temperature with increase of Eu content. This field
+induced transition corresponds to single moment saturation.",1901.10899v1
+2019-06-18,Discovery of room temperature ferromagnetism in metal-free organic semiconductors,"Creating magnetic semiconductors that work at warm circumstance is still a
+great challenge in the physical sciences. Here, we report the discovery of
+ferromagnetism in the metal-free perylene diimide semiconductor, whose Curie
+temperature is higher than 400 Kelvin. A solvothermal approach is used to
+reduce and dissolve the rigid-backbone perylene diimide crystallites, and
+radical anion aggregates were fabricated by the subsequent self-assembly and
+oxidation process. Magnetic measurements exhibit the ferromagnetic ordering
+with the saturated magnetization of 0.48 $\mu_{\rm B}$ per molecule and the
+appreciable magnetic anisotropy. X-ray magnetic circular dichroism spectra
+suggest the ferromagnetism stems from $\pi$ orbitals of radicals. Our findings
+unambitiously demonstrate the long-range ferromagnetic ordering can survive at
+room temperature in organic semiconductors, although which are intuitively
+regarded to be nonmagnetic.",1906.07531v2
+2019-10-03,Shaping Magnetite Nanoparticles from First-principles,"Iron oxide magnetic nanoparticles (NPs) are stimuli-responsive materials at
+the forefront of nanomedicine. Their realistic finite temperature simulations
+are a formidable challenge for first-principles methods. Here, we use density
+functional tight binding to open up the required time and length scales and
+obtain global minimum structures of Fe3O4 NPs of realistic size (1400 atoms,
+2.5 nm) and of different shapes, which we then refine with hybrid density
+functional theory methods to accomplish proper electronic and magnetic
+properties, which have never been accurately described in simulations. On this
+basis, we develop a general empirical formula and prove its predictive power
+for the evaluation of the total magnetic moment of Fe3O4 NPs. By converting the
+total magnetic moment into the macroscopic saturation magnetization, we
+rationalize the experimentally observed dependence with shape. We also reveal
+interesting reconstruction mechanisms and unexpected patterns of charge
+ordering.",1910.01704v2
+2019-11-07,New neutron transmission supermirror remanent polarizer,"A new neutron transmission supermirror remanent polarizer is proposed. The
+polarizer is compact. It consists of two solid state polarizing parts. Parts of
+the polarizer have antiparallel magnetization of magnetic layers of supermirror
+structures. Both parts of the polarizer have magnetic remanence. This allows it
+to be used as a polarizer and analyzer in small magnetic fields. The polarizer
+can be used when working with beams of large cross-section and with a wide
+angular distribution. Assembly of the device is greatly simplified, because it
+is not required to bend a large stack of short plates along the radius, but
+only to compress of its. The width of the angular profile of the beam passed
+through the polarizer does not change! The polarizer has a high transmittance
+for the (-) spin component of the beam. The beam passed through the polarizer
+is highly polarized. Properties of neutron polarizing CoFe/TiZr and Fe/Si
+remanent supermirrors (m = 2.0 and 2.5) are discussed. A variant of effective
+use of the proposed polarizer with a spin-flipper for operation in saturating
+magnetic fields is proposed.",1911.02936v1
+2019-12-18,Magnetization and magneto-transport measurements on CeBi single crystals,"We report the synthesis of CeBi single crystals out of Bi self flux and a
+systematic study of the magnetic and transport properties with varying
+temperature and applied magnetic fields. From these $R(T,H)$ and $M(T,H)$ data
+we could assemble the field-temperature ($H-T$) phase diagram for CeBi and
+visualize the three dimensional $M-T-H$ surface. In the phase diagram, we
+identify regions with well defined magnetization values, and identify a new
+phase region. The magnetoresistance (MR) in the low temperature regime shows,
+above $6~$T a power-law, non-saturated behavior with large MR ($\sim
+3\times10^5 \%$ at $2~$K and $13.95~$T), along with Shubnikov-de Haas
+oscillations. With increasing temperatures, MR decreases, and then becomes
+negative for $T\gtrsim 10~$K. This crossover in MR seems to be unrelated to any
+specific magnetic or metamagnetic transitions, but rather is associated with
+changing from a low-temperature normal metal regime with little or no
+scattering from the Ce$^{3+}$ moments and an anomalously large MR, to an
+increased scattering from local Ce moments and a negative MR as temperature
+increases.",1912.08896v2
+2020-01-21,Huge linear magnetoresistance due to open orbits in $γ$-PtBi$_2$,"Some single-crystalline materials present an electrical resistivity which
+decreases between room temperature and low temperatures at zero magnetic field
+as in a good metal and switches to a nearly semiconductinglike behavior at low
+temperatures with the application of a magnetic field. Often, this is
+accompanied by a huge and nonsaturating linear magnetoresistance which remains
+difficult to explain. Here we present a systematic study of the
+magnetoresistance in single-crystal $\gamma$-PtBi$_2$. We observe that the
+angle between the magnetic field and the crystalline $c$ axis fundamentally
+changes the magnetoresistance, going from a saturating to a nonsaturating
+magnetic field dependence. In between, there is one specific angle where the
+magnetoresistance is perfectly linear with the magnetic field. We show that the
+linear dependence of the nonsaturating magnetoresistance is due to the
+formation of open orbits in the Fermi surface of $\gamma$-PtBi$_2$.",2001.07674v2
+2020-02-26,Enhanced Ferroelectricity and Spin Current Waves in M-Type Barium Hexaferrite,"The intrinsic ferroelectricity and related dielectric properties of M-type
+Barium Hexaferrite (BaFe12O19) with excellent magnetic performance are reported
+in this paper. A classic electric polarization (P-E) hysteresis loop with full
+saturation, together with two nonlinear reversal current peaks in the I-V curve
+and huge change of dielectric constant in the vicinity of Curie temperature,
+have all demonstrated themselves as sufficient experimental evidences to verify
+the ferroelectricity of BaFe12O19 ceramics. It holds a large remnant
+polarization at 108 uC/cm2 and a suitable coercive field at 117 kV/cm. Two
+peaks at 194C and 451C in the temperature-dependent dielectric spectrum of
+BaFe12O19 ceramics are considered to be the phase transition from ferro- to
+antiferro- and antiferro- to para-electric structures. A conventional strong
+magnetic hysteresis loop was also observed. The magnetically induced
+polarization upon the BaFe12O19 ceramics was achieved in the form of
+alternating spin current waves. A ME-coupling voltage with an amplitude of 23mV
+on an applied magnetic field at 500mT was achieved. These combined multiple
+functional responses of large ferroelectrics and strong ferromagnetism reveal
+the excellent multiferroic features of BaFe12O19, which would bring forth the
+great opportunity to create novel electric devices with active coupling effect
+between magnetic and electric orders.",2002.11412v1
+2020-03-31,Magnetic field evolution in solar-type stars,"We discuss selected aspects regarding the magnetic field evolution of
+solar-type stars. Most of the stars with activity cycles are in the range where
+the normalized chromospheric Calcium emission increases linearly with the
+inverse Rossby number. For Rossby numbers below about a quarter of the solar
+value, the activity saturates and no cycles have been found. For Rossby numbers
+above the solar value, again no activity cycles have been found, but now the
+activity goes up again for a major fraction of the stars. Rapidly rotating
+stars show nonaxisymmetric large-scale magnetic fields, but there is
+disagreement between models and observations regarding the actual value of the
+Rossby number where this happens. We also discuss the prospects of detecting
+the sign of magnetic helicity using various linear polarization techniques both
+at the stellar surface using the parity-odd contribution to linear polarization
+and above the surface using Faraday rotation.",2004.00439v1
+2020-06-12,"Enhanced magnetocaloric effect in a mixed spin-(1/2, 1) Ising-Heisenberg two-leg ladder with strong-rung interaction","The magnetic and magnetocaloric properties of the mixed spin-(1/2,1)
+Ising-Heisenberg model on a two-leg ladder with dimer-rung alternation are
+exactly examined under an adiabatic demagnetization process using the
+transfer-matrix formalism. We notify that the magnetization curve of the model
+exhibits plateaux as a function of the applied magnetic field and cyclic
+four-spin Ising interaction at certain rational fractions of the saturation
+value. We precisely investigate the ability of cooling/heating of the model
+nearby the critical points at which discontinuous ground-state phase transition
+occurs. It is evidenced that the model manifests an enhanced magnetocaloric
+effect in a proximity of the magnetization steps and jumps, accompanying with
+the plateaux and jumps of correlation function of the dimer spins. We conclude
+that not only the cooling/heating capability of the model could be pleasantly
+demonstrated by the applied magnetic field variations, but also a typical
+cyclic four-spin Ising interaction plays essential role to determine an
+efficiency of the magnetocaloric effect of the model.",2006.07208v2
+2020-08-02,Thermal stability for domain wall mediated magnetization reversal in perpendicular STT MRAM cells with W insertion layers,"We present an analytical model for calculating energy barrier for the
+magnetic field-driven domain wall-mediated magnetization reversal of a
+magneto-resistive random access memory (MRAM) cell and apply it to study
+thermal stability factor $\Delta$ for various thicknesses of W layers inserted
+into the free layer (FL) as a function of the cell size and temperature. We
+find that, by increasing W thickness, the effective perpendicular magnetic
+anisotropy (PMA) energy density of the FL film monotonically increases, but at
+the same time, $\Delta$ of the cell mainly decreases. Our analysis shows that,
+in addition to saturation magnetization $M_s$ and exchange stiffness constant
+$A_\mathrm{ex}$ of the FL film, the parameter that quantifies the $\Delta$ of
+the cell is its coercive field $H_c$, rather than the net PMA field $H_k$ of
+the FL film comprising the cell.",2008.00412v2
+2020-09-23,Effect of reduced local lattice disorder on the magnetic properties of B-site substituted La0.8Sr0.2MnO3,"Disorder induced by chemical inhomogeneity and Jahn-Teller (JT) distortions
+is often observed in mixed valence perovskite manganites. The main reasons for
+the evolution of this disorder are connected with the cationic size differences
+and the ratio between JT active and non-JT active ions. The quenched disorder
+leads to a spin-cluster state above the magnetic transition temperature. The
+effect of Cu, a B-site substitution in the La0.8Sr0.2MnO3 compound, on the
+disordered phase has been addressed here. X-ray powder diffraction reveals
+rhombohedral (R-3c) structures for the two compounds with negligible change of
+lattice volume. The chemical compositions of the two compounds were verified by
+ion beam analysis technique. With the change of electronic bandwidth, the
+magnetic phase transition temperature has been tuned towards room temperature
+(318 K), an important requirement for room temperature magnetic refrigeration.
+However, a small decrease of the isothermal entropy was observed with
+Cu-substitution, related to the decrease of the saturation magnetization.",2009.11157v2
+2020-10-30,Critical dielectric susceptibility at a magnetic BEC quantum critical point,"Magnetic-field-induced phase transitions are investigated in the frustrated
+gapped quantum paramagnet Rb$_{2}$Cu$_{2}$Mo$_3$O$_{12}$ through dielectric and
+calorimetric measurements on single-crystal samples. It is clarified that the
+previously reported dielectric anomaly at 8~K in powder samples is not due to a
+chiral spin liquid state as has been suggested, but rather to a tiny amount of
+a ferroelectric impurity phase. Two field-induced quantum phase transitions
+between paraelectric and paramagnetic and ferroelectric and magnetically
+ordered states are clearly observed. It is shown that the electric polarization
+is a secondary order parameter at the lower-field (gap closure) quantum
+critical point but a primary one at the saturation transition. Having clearly
+identified the magnetic Bose-Einstein condensation (BEC) nature of the latter,
+we use the dielectric channel to directly measure the critical divergence of
+BEC susceptibility. The observed power-law behavior is in very good agreement
+with theoretical expectations for three-dimensional BEC. Finally, dielectric
+data reveal magnetic presaturation phases in this compound that may feature
+exotic order with unconventional broken symmetries.",2011.00107v2
+2021-01-20,Efficient highly-subsonic turbulent dynamo and growth of primordial magnetic fields,"We present the first study on the amplification of magnetic fields by the
+turbulent dynamo in the highly subsonic regime, with Mach numbers ranging from
+$10^{-3}$ to $0.4$. We find that for the lower Mach numbers the saturation
+efficiency of the dynamo, $(E_{\mathrm{mag}}/E_{\mathrm{kin}})_{\mathrm{sat}}$,
+increases as the Mach number decreases. Even in the case when injection of
+energy is purely through longitudinal forcing modes,
+$(E_{\mathrm{mag}}/E_{\mathrm{kin}})_{\mathrm{sat}}$ $\gtrsim 10^{-2}$ at a
+Mach number of $10^{-3}$. We apply our results to magnetic field amplification
+in the early Universe and predict that a turbulent dynamo can amplify
+primordial magnetic fields to $\gtrsim$ $10^{-16}$ Gauss on scales up to 0.1 pc
+and $\gtrsim$ $10^{-13}$ Gauss on scales up to 100 pc. This produces fields
+compatible with lower limits of the intergalactic magnetic field inferred from
+blazar $\gamma$-ray observations.",2101.08256v1
+2021-04-14,Control of a polar order via magnetic field in a vector-chiral magnet,"Vector-chiral (VC) antiferromagnetism is a spiral-like ordering of spins
+which may allow ferroelectricity to occur due to loss of space inversion
+symmetry. In this paper we report direct experimental observation of
+ferroelectricity in the VC phase of $\beta$-TeVO$_4$, a frustrated spin chain
+system with pronounced magnetic anisotropy and a rich phase diagram. Saturation
+polarization is proportional to neutron scattering intensities that correspond
+to the VC magnetic reflection. This implies that inverse Dzyaloshinskii-Moriya
+mechanism is responsible for driving electric polarization. Linear
+magnetoelectric coupling is absent, however an unprecedented dependence of
+electric coercive field on applied magnetic field reveals a novel way of
+manipulating multiferroic information.",2104.06726v3
+2021-06-22,Incommensurate magnetic order in rare earth and transition metal compounds with local moments,"Within the framework of the $s$-$d(f)$ exchange model in the mean-field
+approximation for square, simple cubic, body-centered and face-centered cubic
+lattices, the formation of a ferromagnetic, spiral, and commensurate
+antiferromagnetic order is investigated. The possibility of the formation of
+inhomogeneous states (magnetic phase separation), which necessarily arises
+during first-order phase transitions in the electron filling parameter, is
+taken into account. The saturation of the antiferromagnetic and spiral states
+is studied depending on the parameters of the model. The results obtained
+include a rich variety of magnetic structures and phase transitions, allowing
+the interpretation of magnetic properties of semiconducting and metallic
+systems containing magnetic atoms.",2106.11697v2
+2021-09-02,Multifold enhancement in magnetization of atomically thin Cobalt Telluride,"Magnetism in semiconductor two-dimensional (2D) materials is gaining
+popularity due to its potential application in memory devices, sensors,
+spintronic and biomedical applications. Here, 2D Cobalt Telluride (CoTe) has
+been synthesized from its bulk crystals using a simple and scalable
+liquid-phase exfoliation method. The atomically thin CoTe shows over four
+hundred times enhancement in its magnetic saturation values compared to the
+bulk form. The UV-Vis absorption spectra reveal superior absorption in the high
+energy region, suggesting a semiconducting nature. Furthermore, we explain
+bandgap and origin of high magnetic behavior by density functional theory (DFT)
+calculations. The 2D CoTe shows a larger magnetism compared to bulk CoTe due to
+the reduced coordination number of the surface atoms, shape anisotropy and
+surface charge effect.",2109.02783v1
+2021-11-09,Quantum oscillations in Noncentrosymmetric Weyl semimetals RAlSi (R = Sm and Ce),"Weyl semimetal (WSM) as a new type of quantum state of matter hosting low
+energy relativistic quasiparticles, has attracted significant attention for
+both scientific community and potential quantum device applications. Here, we
+report a comprehensive investigation of the structural, magnetic and transport
+properties of noncentrosymmetric RAlSi (R = Sm, Ce), which have been predicted
+to be new magnetic WSM candidates. Both samples exhibit non-saturated
+magnetoresistance (MR), with ~ 900% for SmAlSi and 80% for CeAlSi at 1.8 K, 9
+T. The carrier densities of SmAlSi and CeAlSi display remarkable change around
+magnetic transition temperatures, signifying that the electronic states are
+sensitive to magnetic ordering of rare earth elements. At low temperatures,
+SmAlSi reveals prominent Shubnikov-de Haas (SdH) oscillations associated with
+the nontrivial Berry phase. High pressure experiments demonstrate that the
+magnetic order is robust and survival under high pressure. Our results would
+yield valuable insights of WSM physics and potentials in application to the
+next-generation spintronic devices in RAX family.",2111.05235v1
+2022-03-15,Magnetic field-controlled lattice thermal conductivity in MnBi2Te4,"Phonon properties and the lattice thermal conductivity are not generally
+understood to be sensitive to magnetic fields. Using an applied field to change
+MnBi2Te4 between antiferromagnetic (AFM), canted (CAFM) and ferromagnetic (FM)
+phases we discovered a new way to control the lattice thermal conductivity,
+generating both a positive and a negative magnetic field dependence. We report
+the field dependence of the thermal conductivity, k, in the in-plane direction
+under an applied magnetic field along the cross-plane direction in MnBi2Te4
+from 2K to 30K. k decreases with field in the AFM phase, saturates in the CAFM
+phase, and increases with field in the FM phase. We explain this in terms of
+the field-induced changes of the magnon gap which modifies which magnon-phonon
+scattering processes are allowed by energy conservation. We also report
+magneto-Seebeck coefficient, Nernst coefficient and thermal Hall data measured
+in the same configuration. This finding may open a way to design magnetically
+controlled heat switches.",2203.08032v2
+2022-03-18,Domain-knowledge-aided machine learning method for properties prediction of soft magnetic metallic glasses,"A machine learning (ML) method aided by domain knowledge was proposed to
+predict saturated magnetization (Bs) and critical diameter (Dmax) of soft
+magnetic metallic glass (MGs). Two datasets were established based on published
+experimental works about soft magnetic MGs. A general feature space was
+proposed and proved to be adaptive for ML model training for different
+prediction tasks. It was found that the predictive performance of ML models was
+better than traditional physical knowledge-based estimation methods. In
+addition, domain knowledge aided feature selection can greatly reduce the
+number of features without significantly reducing the prediction accuracy.
+Finally, binary classification of the critical size of soft magnetic metallic
+glass was studied.",2203.10951v1
+2022-06-08,SmI3: 4f5 honeycomb magnet with spin-orbital entangled Γ7 Kramers doublet,"We report magnetic properties of a 4f-honeycomb iodide SmI3 made up of
+edge-shared network of SmI6 octahedra. High temperature magnetic susceptibility
+indicates {\Gamma}7 Kramers doublet ground state of Sm3+ (4f5) ions stabilized
+by the spin-orbit coupling and octahedral crystal electric field, which
+interact with Sm-I-Sm bond angle nearly 90 degree. Magnetization measurements
+down to 0.1 K detected antiferromagnetic correlations and an anomaly in the
+magnetization curve before saturation without a sign of long-range order.
+Relevance between SmI3 and the antiferromagnetic Kitaev material proposed in
+the 4f-electron system is discussed.",2206.03628v1
+2022-08-23,Translational Symmetry Broken Magnetization Plateau of the $S=2$ Antiferromagnetic Chain with Anisotropies,"The magnetization plateau of the $S=2$ antiferromagnetic chain with
+interaction and single-ion anisotropies is investigated using the numerical
+diagonalization of finite-size clusters and some size scaling analyses. The
+previous level spectroscopy analysis indicated that two different magnetization
+plateau phases appear at half of the saturation magnetization. One is due to
+the large-$D$ mechanism and the other is due to the Haldane one. In the present
+study the phase diagram is extended to wider region of the anisotropies. As a
+result we find another half magnetization plateau phase, where the
+translational symmetry is spontaneously broken .",2208.10983v1
+2022-12-07,Acoustic Frequency Multiplication and Pure Second Harmonic Generation of Phonons by Magnetic Transducers,"We predict frequency multiplication of surface acoustic waves in dielectric
+substrates via the ferromagnetic resonance of adjacent magnetic transducers
+when driven by microwaves. We find pure second harmonic generation (SHG)
+without any linear and third harmonic components by a magnetic nanowire. The
+SHG and linear phonon pumping are switched by varying the saturated
+magnetization direction of the wire, or resolved directionally when pumped by
+magnetic nano-disc. We address the high efficiency of SHG with comparable
+magnitude to that of linear response, as well as unique non-reciprocal phonon
+transport that is remarkably distinct in different phonon harmonics. Such
+acoustic frequency comb driven by microwaves should bring unprecedented
+tunability for the miniaturized phononic and spintronic devices.",2212.03451v1
+2023-01-09,Long distance magnon transport in the van der Waals antiferromagnet CrPS$_4$,"We demonstrate the potential of van der Waals magnets for spintronic
+applications by reporting long-distance magnon spin transport in the
+electrically insulating antiferromagnet chromium thiophosphate (CrPS$_4$) with
+perpendicular magnetic anisotropy. We inject and detect magnon spins
+non-locally by Pt contacts and monitor the non-local resistance as a function
+of an in-plane magnetic field up to 7 Tesla. We observe a non-local resistance
+over distances up to at least a micron below the Neel temperature (T$_{\rm N}$
+= 38 Kelvin) close to magnetic field strengths that saturate the sublattice
+magnetizations.",2301.03268v1
+2023-02-20,Magnetic Breakdown and Chiral Magnetic Effect at Weyl-Semimetal Tunnel Junctions,"We investigate magnetotransport across an interface between two Weyl
+semimetals whose Weyl nodes project onto different interface momenta. Such an
+interface generically hosts Fermi arcs that connect Weyl nodes of identical
+chirality in different Weyl semimetals (homochiral connectivity) -- in contrast
+to surface Fermi arcs that connect opposite-chirality Weyl nodes within the
+same Weyl semimetal (heterochiral connectivity). We show that electron
+transport along the arcs with homochiral connectivity, in the presence of a
+longitudinal magnetic field, leads to a universal longitudinal
+magnetoconductance of $e^2/h$ per magnetic flux quantum. Furthermore, a weak
+tunnel coupling can result in a close encounter of two homochiral-connectivity
+Fermi arcs, enabling magnetic breakdown. Above the breakdown field the
+interface Fermi arc connectivity is effectively heterochiral, leading to a
+saturation of the conductance.",2302.09896v1
+2023-04-01,Pulsed $^{87}$Rb vector magnetometer using a fast rotating field,"There are diverse set approaches for vector magnetic field measurements
+involving condensed matter and atomic physics systems. However, they all suffer
+from various limitations, so the most widely used high-sensitivity vector
+magnetometers are fluxgates using soft magnetically-saturable materials. Here
+we describe a vector magnetometer by applying an external rotating magnetic
+field to a scalar atomic magnetometer. Such an approach provides simultaneous
+measurements of the total magnetic field and two polar angles relative to the
+plane of magnetic field rotation. Crucially, it avoids several metrological
+difficulties associated with vector magnetometers and gradiometers. We describe
+in detail the fundamental, systematic, and practical limits of such vector
+magnetometers. We use a field rotation rate faster than the spin relaxation
+rate. We show that it eliminates a class of systematic effects associated with
+heading errors in alkali-metal scalar magnetometers. We investigate several
+other systematic effects, such as Berry's phase frequency shift and the effects
+of eddy currents in nearby conductors. We also derive fundamental limits on the
+sensitivity of such sensors and show that the vector sensitivity can approach
+the sensitivity of scalar atomic magnetometers.",2304.00214v1
+2023-11-20,Surface spin polarization in the magnetic response of GeTe Rashba ferroelectric,"We experimentally investigate magnetization reversal curves for a GeTe
+topological semimetal. In addition to the known lattice diamagnetic response,
+we observe narrow magnetization loop in low fields, which should not be
+expected for non-magnetic GeTe. The hysteresis is unusual, so the saturation
+level is negative in positive fields, and the loop is passed clockwise, in
+contrast to standard ferromagnetic behavior. The experimental hysteresis curves
+can not be obtained from usual ferromagnetic ones by adding/subtracting of any
+linear dependence, or even by considering several interacting magnetic phases.
+The possibility of several phases is also eliminated by the remanence plots
+technique (Henkel or {\delta}M plots). We explain our results as a direct
+consequence of the correlation between ferroelectricity and spin-polarized
+surface states in GeTe, similarly to magnetoelectric structures.",2311.11831v1
+2023-11-30,Growth of high-quality CrI3 single crystals and engineering of its magnetic properties via V and Mn doping,"CrI3, as a soft van der Waals layered magnetic material, has been widely
+concerned and explored for its magnetic complexity and tunability. In this
+work, high quality and large size thin CrI3, V and Mn doped single crystals
+were prepared by chemical vapor transfer method. A remarkable irreversible
+Barkhausen effect was observed in CrI3 and CrMn0.06I3, which can be attributed
+to the low dislocation density that facilitates movement of the domain walls.
+In addition, the introduction of the doping element Mn allows higher saturation
+magnetization intensity. Cr0.5V0.5I3 exhibits substantially increased
+coercivity force and larger magnetocrystalline anisotropy compared to CrI3,
+while kept similar Curie temperature and good environmental stability. The
+first principles calculations suggest direct and narrowed band gaps in
+Cr0.5V0.5I3 and VI3 comparing to CrI3. The smaller band gaps and good hard
+magnetic property make Cr0.5V0.5I3 an alternative choice to future research of
+spintronic devices.",2311.18360v1
+2009-10-06,Diffusion of magnetic field and removal of magnetic flux from clouds via turbulent reconnection,"The diffusion of astrophysical magnetic fields in conducting fluids in the
+presence of turbulence depends on whether magnetic fields can change their
+topology via reconnection in highly conducting media. Recent progress in
+understanding fast magnetic reconnection in the presence of turbulence is
+reassuring that the magnetic field behavior in computer simulations and
+turbulent astrophysical environments is similar, as far as magnetic
+reconnection is concerned. Our studies of magnetic field diffusion in turbulent
+medium reveal interesting new phenomena. In the presence of gravity and
+turbulence, our 3D simulations show the decrease of the magnetic flux-to-mass
+ratio as the gaseous density at the center of the gravitational potential
+increases. We observe this effect both in the situations when we start with
+equilibrium distributions of gas and magnetic field and when we follow the
+evolution of collapsing dynamically unstable configurations. Thus the process
+of turbulent magnetic field removal should be applicable both to quasi-static
+subcritical molecular clouds and cores and violently collapsing supercritical
+entities. The increase of the gravitational potential as well as the
+magnetization of the gas increases the segregation of the mass and magnetic
+flux in the saturated final state of the simulations, supporting the notion
+that the reconnection-enabled diffusivity relaxes the magnetic field + gas
+system in the gravitational field to its minimal energy state. This effect is
+expected to play an important role in star formation, from its initial stages
+of concentrating interstellar gas to the final stages of the accretion to the
+forming protostar.",0910.1117v3
+2020-05-07,A global model of the magnetorotational instability in protoneutron stars,"Magnetars are highly magnetized neutron stars whose magnetic dipole ranges
+from $10^{14}$ to $10^{15}$ G. The MRI is considered to be a promising
+mechanism to amplify the magnetic field in fast-rotating protoneutron stars and
+form magnetars. This scenario is supported by many local studies showing that
+magnetic fields could be amplified by the MRI on small scales. However, the
+efficiency of the MRI at generating a dipole field is still unknown. To answer
+this question, we study the MRI dynamo in an idealized global model of a fast
+rotating protoneutron star with differential rotation. We perform 3D
+incompressible MHD simulations in spherical geometry with explicit
+diffusivities where the differential rotation is forced at the outer boundary.
+We vary the initial magnetic field and investigated different magnetic boundary
+conditions. These simulations were compared to local shearing box simulations.
+We obtain a self-sustained turbulent MRI-driven dynamo, whose saturated state
+is independent of the initial magnetic field. The MRI generates a strong
+turbulent magnetic field of $B \geq 2\times 10^{15}$ G and a non-dominant
+magnetic dipole, which represents systematically about $5\%$ of the averaged
+magnetic field strength. Interestingly, this dipole is tilted towards the
+equatorial plane. We find that local shearing box models can reproduce fairly
+well several characteristics of global MRI turbulence such as the kinetic and
+magnetic spectra. The turbulence is nonetheless more vigorous in the local
+models than in the global ones. Overall, our results support the ability of the
+MRI to form magnetar-like large-scale magnetic fields. They furthermore predict
+the presence of a stronger small-scale magnetic field. The resulting magnetic
+field could be important to power outstanding stellar explosions, such as
+superluminous supernovae and GRBs.",2005.03567v2
+2000-09-06,"Two-Dimensional MHD Numerical Simulations of Magnetic Reconnection Triggered by A Supernova Shock in Interstellar Medium, Generation of X-Ray Gas in Galaxy","We examine the magnetic reconnection triggered by a supernova (or a point
+explosion) in interstellar medium, by performing two-dimensional resistive
+magnetohydrodynamic (MHD) numerical simulations with high spatial resolution.
+We found that the magnetic reconnection starts long after a supernova shock
+(fast-mode MHD shock) passes a current sheet. The current sheet evolves as
+follows: (i) Tearing-mode instability is excited by the supernova shock, and
+the current sheet becomes thin in its nonlinear stage. (ii) The current-sheet
+thinning is saturated when the current-sheet thickness becomes comparable to
+that of Sweet-Parker current sheet. After that, Sweet-Parker type reconnection
+starts, and the current-sheet length increases. (iii) ``Secondary tearing-mode
+instability'' occurs in the thin Sweet-Parker current sheet. (iv) As a result,
+further current-sheet thinning occurs and anomalous resistivity sets in,
+because gas density decreases in the current sheet. Petschek type reconnection
+starts and heats interstellar gas. Magnetic energy is released quickly while
+magnetic islands are moving in the current sheet during Petschek type
+reconnection. The released magnetic energy is determined by the interstellar
+magnetic field strength, not energy of initial explosion nor distance to
+explosion. We suggest that magnetic reconnection is a possible mechanism to
+generate X-ray gas in Galaxy.",0009088v2
+1999-10-25,Finite-size versus Surface effects in nanoparticles,"We study the finite-size and surface effects on the thermal and spatial
+behaviors of the magnetisation of a small magnetic particle. We consider two
+systems: 1) A box-shaped isotropic particle of simple cubic structure with
+either periodic or free boundary conditions. This case is treated analytically
+using the isotropic model of D-component spin vectors in the limit $D\to
+\infty$, including the magnetic field. 2) A more realistic particle ($\gamma
+$-Fe$_{2}$O$_{3}$) of ellipsoidal (or spherical) shape with open boundaries.
+The magnetic state in this particle is described by the anisotropic classical
+Dirac-Heisenberg model including exchange and dipolar interactions, and bulk
+and surface anisotropy. This case is dealt with by the classical Monte Carlo
+technique. It is shown that in both systems finite-size effects yield a
+positive contribution to the magnetisation while surface effects render a
+larger and negative contribution, leading to a net decrease of the
+magnetisation of the small particle with respect to the bulk system. In the
+system 2) the difference between the two contributions is enhanced by surface
+anisotropy. The latter also leads to non saturation of the magnetisation at low
+temperatures, showing that the magnetic order in the core of the particle is
+perturbed by the magnetic disorder on the surface. This is confirmed by the
+profile of the magnetisation.",9910393v1
+2001-07-23,"New two dimensional S=1/2 Heisenberg antiferromagnets: synthesis, structure and magnetic properties","The magnetic susceptibility and magnetization of two new layered S=1/2
+Heisenberg antiferromagnets with moderate exchange are reported. The two
+isostructural compounds, (2-amino-5-chloropyridinium)2CuBr4 ((5CAP)2CuBr4) and
+(2-amino-5-methylpyridinium)2CuBr4 ((5MAP)2CuBr4), contain S=1/2, Cu(II) ions
+related by C-centering, yielding four equivalent nearest neighbors. The crystal
+structure of newly synthesized compound, (5CAP)2CuBr4, shows the existence of
+layers of distorted copper(II)-bromide tetrahedra parallel to the ab plane,
+separated by the organic cations along the c axis. Magnetic pathways are
+available through the bromide-bromide contacts within the layers and provide
+for moderate antiferromagnetic exchange. Susceptibility measurements indicate
+interaction strengths to be 8.5(1) K, and 6.5(1) K and ordering temperatures of
+5.1(2) K and 3.8(2) K for (5CAP)2CuBr4 and (5MAP)2CuBr4 respectively. High
+field magnetization experiments on both compounds show upward curvature of
+M(H,T). Magnetization measurements made at T = 1.3 K show saturation occurs in
+(5MAP)2CuBr4 at 18.8 T and in (5CAP)2CuBr4 at 24.1 T. The magnetization curves
+are consistent with recent theoretical predictions. Single crystal
+magnetization measured at 2.0 K indicate a spin flop transition at 0.38 T and
+0.63 T for (5CAP)2CuBr4 and (5MAP)2CuBr4 respectively.",0107483v3
+2003-05-13,Thermal Remagnetization in Polycrystalline Permanent Magnets,"The thermal remagnetization (TR), i.e. the reentrance of magnetization upon
+heating in a steady-field demagnetized sample, is a common feature to the four
+types of polycrystalline permanent magnets, mainly utilized for practical
+purposes, i.e. barium ferrites, SmCo5, Sm2Co17 and NdFeB magnets. The effect is
+small for pinning controlled and large for nucleation controlled magnets. The
+effect is strongly dependent on the demagnetization factor and may reach nearly
+100 per cent in SmCo5 samples measured in a closed circuit. The TR is very
+sensitive to a small superimposed steady field. The maximum effect and the
+position of the peak is dependent on the initial temperature. The direction of
+the TR is correlated with the temperature coefficient of the coercivity,
+resulting in a inverse TR in barium ferrite. The susceptibility of the
+thermally remagnetized samples is increased. Repeated cycles of steady-field
+demagnetization followed by heating result in the same TR. The phenomenology of
+TR and ITR is explained by means of a model taking into account both the
+internal field fluctuations due to grain interactions and the decay of single
+domain grains into multi-domain state. By taking the measured temperature
+dependencies of the coercivity and the saturation magnetization the theory is
+able to reproduce the experiments very well, allowing to determine the width of
+the field fluctuations, the width of the switching field distribution and an
+internal demagnetization factor as characteristics of the materials by fitting.",0305292v1
+2004-03-22,Magnetic properties of a helical spin chain with alternating isotropic and anisotropic spins: magnetization plateaus and finite entropy,"We study a model which could explain some of the unusual magnetic properties
+observed for the one-dimensional helical spin system Co(hfac)_2 NITPhOMe. One
+of the properties observed is that the magnetization shows plateaus near zero
+and near one-third of the saturation value if a magnetic field is applied along
+the helical axis, but not if the field is applied in the plane perpendicular to
+that axis. The system consists of a spin-1/2 chain in which cobalt ions (which
+are highly anisotropic with an easy axis e_i) and organic radicals (which are
+isotropic) alternate with each other. The easy axis of the cobalts e_i lie at
+an angle theta_i with respect to the helical axis, while the projection of
+e_{i+1} - e_i on the plane perpendicular to the helical axis is given by 2 pi
+/3. For temperatures and magnetic fields which are much smaller than the
+coupling between the nearest-neighbor cobalts and radicals, one can integrate
+out the radicals to obtain an Ising model for the cobalts; this enables one to
+compute the thermodynamic properties of the system using the transfer matrix
+approach. We consider a model in which the tilt angles theta_i are allowed to
+vary with i with period three; we find that for certain patterns of theta_i,
+the system shows the magnetization plateaus mentioned above. At the ends of the
+plateaus, the entropy is finite even at very low temperatures, while the
+magnetic susceptibility and specific heat also show some interesting features.",0403555v1
+2004-08-27,Spin reorientation and in-plane magnetoresistance of lightly doped La_{2-x}Sr_{x}CuO_{4} in magnetic fields up to 55 T,"The magnetoresistance (MR) in the in-plane resistivity is measured in
+magnetic fields up to 55 T in lightly doped La_{2-x}Sr_{x}CuO_{4} in the N\'eel
+state (x = 0.01) and in the spin-glass state (x = 0.03) using high-quality
+untwinned single crystals. In both cases, a large negative MR is observed to
+appear when the magnetic order is established. For x = 0.01, it is found that
+the MR is indicative of a one-step transition into a high-field
+weak-ferromagnetic state at around 20 T when the magnetic field is applied from
+the spin easy axis (b axis), which means that there is no spin-flop transition
+in the N\'eel state of this material; this is contrary to a previous report,
+but is natural in light of the peculiar in-plane magnetic susceptibility
+anisotropy recently found in this system. In the spin-glass state, we observe
+that the large (up to \sim20%) negative MR saturates at around 40 T, and this
+MR is found to be essentially isotropic when the magnetic field is rotated
+within the ab plane. Our data show that the large negative MR is inherent to
+LSCO in a magnetically ordered state, in which the weak-ferromagnetic (WF)
+moment becomes well-defined; we discuss that the observed MR is essentially due
+to the reorientation of the WF moments towards the magnetic field direction
+both in the N\'eel state and in the spin-glass state.",0408604v1
+2009-05-06,Formation of gaseous arms in barred galaxies with dynamically important magnetic field : 3D MHD simulations,"We present results of three-dimensional nonlinear MHD simulations of a
+large-scale magnetic field and its evolution inside a barred galaxy with the
+back reaction of the magnetic field on the gas. The model does not consider the
+dynamo process. To compare our modeling results with observations, we construct
+maps of the high-frequency (Faraday-rotation-free) polarized radio emission on
+the basis of simulated magnetic fields. The model accounts for the effects of
+projection and the limited resolution of real observations. We performed 3D MHD
+numerical simulations of barred galaxies and polarization maps. The main result
+is that the modeled magnetic field configurations resemble maps of the
+polarized intensity observed in barred galaxies. They exhibit polarization
+vectors along the bar and arms forming coherent structures similar to the
+observed ones. In the paper, we also explain the previously unsolved issue of
+discrepancy between the velocity and magnetic field configurations in this type
+of galaxies. The dynamical influence of the bar causes gas to form spiral waves
+that travel outwards. Each gaseous spiral arm is accompanied by a magnetic
+counterpart, which separates and survives in the inter-arm region. Because of a
+strong compression, shear of non-axisymmetric bar flows and differential
+rotation, the total energy of modeled magnetic field grows constantly, while
+the azimuthal flux grows slightly until $0.05\Gyr$ and then saturates.",0905.0845v1
+2009-10-19,Magnetic properties of EuPtSi$_3$ single crystals,"Single crystals of EuPtSi$_3$, which crystallize in the BaNiSn$_3$-type
+crystal structure, have been grown by high temperature solution growth method
+using molten Sn as the solvent. EuPtSi$_3$ which lacks the inversion symmetry
+and has only one Eu site in the unit cell is found to be an antiferromagnet
+with two successive magnetic transitions at $T_{\rm N1}$ = 17 K and $T_{\rm
+N2}$ = 16 K, as inferred from magnetic susceptibility, heat capacity and
+$^{151}$Eu M\""ossbauer measurements. The isothermal magnetization data for $H
+\parallel$ [001] reveal a metamagnetic transition at a critical field $H_{\rm
+c}$ = 1 T. The magnetization saturates to a moment value of 6.43 $\mu_{\rm
+B}$/Eu above 5.9 T (9.2 T) for $H \parallel $ [001] ([100]), indicating that
+these fields are spin-flip fields for the divalent Eu moments along the two
+axes. The origin of this anisotropic behaviour is discussed. A magnetic (H, T)
+phase diagram has been constructed from the temperature dependence of
+isothermal magnetization data. The reduced jump in the heat capacity at $T_{\rm
+N1}$ indicates a transition to an incommensurate, amplitude modulated
+antiferromagnetic structure. The shape of the hyperfine field split M\""ossbauer
+spectrum at $T_{\rm N1}$ provides additional support for the proposed nature of
+this magnetic transition.",0910.3517v2
+2011-10-20,Magnetic properties of the spin $S=1/2$ Heisenberg chain with hexamer modulation of exchange,"We consider the spin-1/2 Heisenberg chain with alternating spin exchange %on
+even and odd sites in the presence of additional modulation of exchange on odd
+bonds with period three. We study the ground state magnetic phase diagram of
+this hexamer spin chain in the limit of very strong antiferromagnetic (AF)
+exchange on odd bonds using the numerical Lanczos method and bosonization
+approach. In the limit of strong magnetic field commensurate with the
+dominating AF exchange, the model is mapped onto an effective $XXZ$ Heisenberg
+chain in the presence of uniform and spatially modulated fields, which is
+studied using the standard continuum-limit bosonization approach. In absence of
+additional hexamer modulation, the model undergoes a quantum phase transition
+from a gapped string order into the only one gapless L\""uttinger liquid (LL)
+phase by increasing the magnetic field. In the presence of hexamer modulation,
+two new gapped phases are identified in the ground state at magnetization equal
+to 1/3 and 2/3 of the saturation value. These phases reveal themselves also in
+magnetization curve as plateaus at corresponding values of magnetization. As
+the result, the magnetic phase diagram of the hexamer chain shows seven
+different quantum phases, four gapped and three gapless and the system is
+characterized by six critical fields which mark quantum phase transitions
+between the ordered gapped and the LL gapless phases.",1110.4467v3
+2013-05-23,Holographic Photon Production with Magnetic Field in Anisotropic Plasmas,"We investigate the thermal photon production from constant magnetic field in
+a strongly coupled and anisotropic plasma via the gauge/gravity duality. The
+dual geometry with pressure anisotropy is generated from the axion-dilaton
+gravity action introduced by Mateos and Trancancelli and the magnetic field is
+coupled to fundamental matters(quarks) through the D3/D7 embeddings. We find
+that the photon spectra with different quark mass are enhanced at large
+frequency when the photons are emitted parallel to the anisotropic direction
+with larger pressure or perpendicular to the magnetic field. However, in the
+opposite conditions for the emitted directions, the spectra approximately
+saturate isotropic results in the absence of magnetic field. On the other hand,
+a resonance emerges at moderate frequency for the photon spectrum with heavy
+quarks when the photons move perpendicular to the magnetic field. The resonance
+is more robust when the photons are polarized along the magnetic field. On the
+contrary, in the presence of pressure anisotropy, the resonance will be
+suppressed. There exist competing effects of magnetic field and pressure
+anisotropy on meson melting in the strongly coupled super Yang-Mills plasma,
+while we argue that the suppression led by anisotropy may not be applied to the
+quark gluon plasma.",1305.5509v3
+2013-08-01,Magnetostatic wave analog of integer quantum Hall state in patterned magnetic films,"A magnetostatic spin wave analog of integer quantum Hall (IQH) state is
+proposed in realistic patterned ferromagnetic thin films. Due to magnetic shape
+anisotropy, magnetic moments in a thin film lie within the plane, while all
+spin-wave excitations are fully gapped. Under an out-of-plane magnetic field,
+the film acquires a finite magnetization, where some of the gapped magnons
+become significantly softened near a saturation field. It is shown that, owing
+to a spin-orbit locking nature of the magnetic dipolar interaction, these soft
+spin-wave volume-mode bands become chiral volume-mode bands with finite
+topological Chern integers. A bulk-edge correspondence in IQH physics suggests
+that such volume-mode bands are accompanied by a chiral magnetostatic spin-wave
+edge mode. The existence of the edge mode is justified both by micromagnetic
+simulations and by band calculations based on a linearized Landau-Lifshitz
+equation. Employing intuitive physical arguments, we introduce proper
+tight-binding models for these soft volume-mode bands. Based on the
+tight-binding models, we further discuss possible applications to other systems
+such as magnetic ultrathin films with perpendicular magnetic anisotropy (PMA).",1308.0199v3
+2013-08-31,Nature of the magnetic ground state in the mixed valence compound CeRuSn: a single-crystal study,"We report on detailed low temperature measurements of the magnetization, the
+specific heat and the electrical resistivity on high quality CeRuSn single
+crystals. The compound orders antiferromagnetically at $T_{\rm N} = 2.8$ K with
+the Ce$^{3+}$ ions locked within the $a-c$ plane of the monoclinic structure.
+Magnetization shows that below $T_{\rm N}$ CeRuSn undergoes a metamagnetic
+transition when applying a magnetic field of 1.5 and 0.8 T along the $a$ and
+$c$--axis, respectively. This transition manifests in a tremendous negative
+jump of $\sim 25$% in the magnetoresistance. The value of the saturated
+magnetization along the easy magnetization direction ($c$--axis) and the
+magnetic entropy above $T_{\rm N}$ derived from specific heat data correspond
+to the scenario where only one third of the Ce ions in the compound being
+trivalent and carrying a stable Ce$^{3+}$ magnetic moment, whereas the other
+two thirds of the Ce ions are in a nonmagnetic tetravalent and/or mixed valence
+state. This is consistent with the low temperature CeRuSn crystal structure
+i.\,e.\,, a superstructure consisting of three unit cells of the CeCoAl-type
+piled up along the $c$--axis, and in which the Ce$^{3+}$ ions are characterized
+by large distances from the Ru ligands while the Ce-Ru distances of the other
+Ce ions are much shorter causing a strong 4{\it f}-ligand hybridization and
+hence leading to tetravalent and/or mixed valence Ce ions.",1309.0106v1
+2017-03-21,Microstrain induced deviation from Néel's 1/d behaviour: Size-dependent magnetization in Bi1-xCaxFe1-yTiyO3-delta nanoparticles,"Magnetization of antiferromagnetic nanoparticles is known to generally scale
+up inversely to their diameter (d) according to N\'eel's model. Here we report
+a deviation from this conventional linear 1/d dependence, altered significantly
+by the microstrain, in Ca and Ti substituted BiFeO3 nanoparticles. Magnetic
+properties of microstrain-controlled Bi1-xCaxFe1-yTiyO3-delta (y = 0 and x = y)
+nanoparticles are analyzed as a function of their size ranging from 18 nm to
+200 nm. A complex interdependence of doping concentration (x or y), annealing
+temperature (T), microstrain (epsilon) and particle size (d) is established.
+X-ray diffraction studies reveal a linear variation of microstrain with inverse
+particle size, 1/d nm-1 (i.e. epsilon.d = 16.5 nm.%). A rapid increase in the
+saturation magnetization below a critical size dc ~ 35 nm, exhibiting a
+(1/d)^alpha (alpha ~ 2.6) dependence, is attributed to the influence of
+microstrain. We propose an empirical formula M is proportional to
+(1/d)epsilon^beta (beta ~ 1.6) to highlight the contributions from both the
+size and microstrain towards the total magnetization in the doped systems. The
+magnetization observed in nanoparticles is thus, a result of competing magnetic
+contribution from the terminated spin cycloid on the surface and counteracting
+microstrain present at a given size. Large magnetodielectric response of ~ 9.5
+% is observed in spark plasma sintered pellets with optimal size and doping
+concentration, revealing a strong correlation between magnetic and
+ferroelectric order parameters.",1703.07190v1
+2017-06-06,Magnetic order and interactions in ferrimagnetic Mn3Si2Te6,"The magnetism in Mn$_3$Si$_2$Te$_6$ has been investigated using thermodynamic
+measurements, first principles calculations, neutron diffraction and diffuse
+neutron scattering on single crystals. These data confirm that
+Mn$_3$Si$_2$Te$_6$ is a ferrimagnet below a Curie temperature of $T_C$
+approximately 78K. The magnetism is anisotropic, with magnetization and neutron
+diffraction demonstrating that the moments lie within the basal plane of the
+trigonal structure. The saturation magnetization of approximately 1.6$\mu_B$/Mn
+at 5K originates from the different multiplicities of the two
+antiferromagnetically-aligned Mn sites. First principles calculations reveal
+antiferromagnetic exchange for the three nearest Mn-Mn pairs, which leads to a
+competition between the ferrimagnetic ground state and three other magnetic
+configurations. The ferrimagnetic state results from the energy associated with
+the third-nearest neighbor interaction, and thus long-range interactions are
+essential for the observed behavior. Diffuse magnetic scattering is observed
+around the 002 Bragg reflection at 120K, which indicates the presence of strong
+spin correlations well above $T_C$. These are promoted by the competing ground
+states that result in a relative suppression of $T_C$, and may be associated
+with a small ferromagnetic component that produces anisotropic magnetism below
+$\approx$330K.",1706.01925v1
+2017-06-13,Novel Exotic Magnetic Spin-order in Co5Ge3 Nano-size Materials,"The Cobalt-germanium (Co-Ge) is a fascinating complex alloy system that has
+unique structure and exhibit range of interesting magnetic properties which
+would change when reduce to nanoscale dimension. At this experimental work, the
+high-aspect-ratio Co5Ge3 nanoparticle with average size of 8nm was synthesized
+by gas aggregation-type cluster-deposition technology. The nanostructure
+morphology of the as-made binary Co5Ge3 nanoparticles demonstrate excellent
+single-crystalline hexagonal structure with mostly preferable growth along
+(110) and (102) directions. In contrast the bulk possess Pauli paramagnetic
+spin-order at all range of temperature, here we discover size-driven new
+magnetic ordering of as-synthesized Co5Ge3 nanoparticles exhibiting
+ferromagnetism at room temperature with saturation magnetization of Ms = 32.2
+emu/cm3. This is first report of observing such new magnetic spin ordering in
+this kind of material at nano-size which the magnetization has lower
+sensitivity to thermal energy fluctuation and exhibit high Curie temperature
+close to 850 K. This ferromagnetic behavior along with higher Curie temperature
+at Co5Ge3 nanoparticles are attributes to low-dimension and quantum-confinement
+effect which imposes strong spin coupling and provides a new set of size-driven
+spin structures in Co5Ge3 nanoparticle which no such magnetic behavior being
+present in the bulk of same material. This fundamental scientific study
+provides important insights into the formation, structural, and the magnetic
+property of sub 10nm Co5Ge3 nanostructure which shall lead to promising
+practical versatile applications for magneto- germanide based nano-devices.",1706.04271v2
+2017-09-04,Many-body forces in magnetic neutron stars,"In this work, we study in detail the effects of many-body forces on the
+equation of state and the structure of magnetic neutron stars. The stellar
+matter is described within a relativistic mean field formalism that takes into
+account many-body forces by means of a non-linear meson field dependence on the
+nuclear interaction coupling constants. We assume that matter is at zero
+temperature, charge neutral, in beta-equilibrium, and populated by the baryon
+octet, electrons, and muons. In order to study the effects of different degrees
+of stiffness in the equation of state, we explore the parameter space of the
+model, which reproduces nuclear matter properties at saturation, as well as
+massive neutron stars. Magnetic field effects are introduced both in the
+equation of state and in the macroscopic structure of stars by the
+self-consistent solution of the Einstein-Maxwell equations. In addition,
+effects of poloidal magnetic fields on the global properties of stars, as well
+as density and magnetic field profiles are investigated. We find that not only
+different macroscopic magnetic field distributions, but also different
+parameterizations of the model for a fixed magnetic field distribution impact
+the gravitational mass, deformation and internal density profiles of stars.
+Finally, we also show that strong magnetic fields affect significantly the
+particle populations of stars",1709.01017v1
+2018-05-19,Frustration of square cupola in Sr(TiO)Cu$_{4}$(PO$_{4}$)$_{4}$,"The structural and magnetic properties of the square-cupola antiferromagnet
+Sr(TiO)Cu$_{4}$(PO$_{4}$)$_{4}$ are investigated via x-ray diffraction,
+magnetization, heat capacity, and $^{31}$P nuclear magnetic resonance
+experiments on polycrystalline samples, as well as density-functional
+band-structure calculations. The temperature-dependent unit cell volume could
+be described well using the Debye approximation with the Debye temperature of
+$\theta_{\rm D} \simeq $ 550~K. Magnetic response reveals a pronounced
+two-dimensionality with a magnetic long-range-order below $T_{\rm N} \simeq
+6.2$~K. High-field magnetization exhibits a kink at $1/3$ of the saturation
+magnetization. Asymmetric $^{31}$P NMR spectra clearly suggest strong in-plane
+anisotropy in the magnetic susceptibility, as anticipated from the crystal
+structure. From the $^{31}$P NMR shift vs bulk susceptibility plot, the
+isotropic and axial parts of the hyperfine coupling between $^{31}$P nuclei and
+the Cu$^{2+}$ spins are calculated to be $A_{\rm hf}^{\rm iso} \simeq 6539$ and
+$A_{\rm hf}^{\rm ax} \simeq 952$~Oe/$\mu_{\rm B}$, respectively. The
+low-temperature and low-field $^{31}$P NMR spectra indicate a commensurate
+antiferromagnetic ordering. Frustrated nature of the compound is inferred from
+the temperature-dependent $^{31}$P NMR spin-lattice relaxation rate and
+confirmed by our microscopic analysis that reveals strong frustration of the
+square cupola by next-nearest-neighbor exchange couplings.",1805.07497v1
+2018-05-22,Small-scale dynamo simulations: Magnetic field amplification in exploding granules and the role of deep and shallow recirculation,"We analyze recent high resolution photospheric small-scale dynamo simulations
+that were computed with the MURaM radiative MHD code. We focus the analysis on
+newly forming downflow lanes in exploding granules since they show how weakly
+magnetized regions in the photosphere (center of granules) evolve into strongly
+magnetized regions (downflow lanes). We find that newly formed downflow lanes
+exhibit initially mostly a laminar converging flow that amplifies the vertical
+magnetic field embedded in the granule from a few 10 G to field strengths
+exceeding 800 G. This results in extended magnetic sheets that have a length
+comparable to granular scales. Field amplification by turbulent shear happens
+first a few 100 km beneath the visible layers of the photosphere. Shallow
+recirculation transports the resulting turbulent field into the photosphere
+within minutes, after which the newly formed downflow lane shows a mix of
+strong magnetic sheets and turbulent field components. We stress in particular
+the role of shallow and deep recirculation for the organization and strength of
+magnetic field in the photosphere and discuss the photospheric and
+sub-photospheric energy conversion associated with the small-scale dynamo
+process. While the energy conversion through the Lorentz force depends only
+weakly on the saturation field strength (and therefore deep or shallow
+recirculation), it is strongly dependent on the magnetic Prandtl number. We
+discuss the potential of these findings for further constraining small-scale
+dynamo models through high resolution observations.",1805.08390v1
+2019-01-28,Study of Dynamo Action in Three Dimensional Magnetohydrodynamic Plasma with Arnold-Beltrami-Childress Flow,"For a three dimensional magnetohydrodynamic (MHD) plasma the dynamo action
+with ABC flow as initial condition has been studied. The study delineates
+crucial parameter that gives a transition from coherent nonlinear oscillation
+to dynamo. Further, for both kinematic and dynamic models at magnetic Prandtl
+number equal to unity the dynamo action is studied for driven ABC flows. The
+magnetic resistivity has been chosen at a value where the fast dynamo occurs
+and the growth rate shows no further variation with the change of magnetic
+Reynold's number. The exponent of growth of magnetic energy increases,
+indicating a faster dynamo, if a higher wave number is excited compared to the
+one with a lower wave number. The result has been found to hold good for both
+kinematic and externally forced dynamic dynamos where the backreaction of
+magnetic field on the velocity field is no more negligible. In case of an
+externally forced dynamic dynamo, the super Alfvenic flows have been found to
+excite strong dynamos giving rise to the growth of magnetic energy of seven
+orders of magnitude. The back-reaction of magnetic field on the velocity field
+through Lorentz force term has been found to affect the dynamics of the
+velocity field and in turn the dynamics of magnetic field, leading to a
+saturation, when the dynamo action is very prominent.",1901.09610v1
+2019-02-11,"Magnetization process of the insulating ferromagnetic semiconductor (Al,Fe)Sb","We have studied the magnetization process of the new insulating ferromagnetic
+semiconductor (Al,Fe)Sb by means of x-ray magnetic circular dichroism. For an
+optimally doped sample with 10% Fe, a magnetization was found to rapidly
+increase at low magnetic fields and to saturate at high magnetic fields at room
+temperature, well above the Curie temperature of 40 K. We attribute this
+behavior to the existence of nanoscale Fe-rich ferromagnetic domains acting as
+superparamagnets. By fitting the magnetization curves using the Langevin
+function representing superparamagnetism plus the paramagnetic linear function,
+we estimated the average magnetic moment of the nanoscale ferromagnetic domain
+to be 300-400 $\mu_{B}$, and the fraction of Fe atoms participating in the
+nano-scale ferromagnetism to be $\sim$50%. Such behavior was also reported for
+(In,Fe)As:Be and Ge:Fe, and seems to be a universal characteristic of the
+Fe-doped ferromagnetic semiconductors. Further Fe doping up to 14% led to the
+weakening of the ferromagnetism probably because antiferromagnetic
+superexchange interaction between nearest-neighbor Fe-Fe pairs becomes
+dominant.",1902.03742v1
+2019-08-15,Breakdown of intermediate one-half magnetization plateau of spin-1/2 Ising-Heisenberg and Heisenberg branched chains at triple and Kosterlitz-Thouless critical points,"The spin-1/2 Ising-Heisenberg branched chain composed of regularly
+alternating Ising spins and Heisenberg dimers involving an additional side
+branching is rigorously solved in a magnetic field by the transfer-matrix
+approach. The ground-state phase diagram, the magnetization process and the
+concurrence measuring a degree of bipartite entanglement within the Heisenberg
+dimers are examined in detail. Three different ground states were found
+depending on a mutual interplay between the magnetic field and two different
+coupling constants: the modulated quantum antiferromagnetic phase, the quantum
+ferrimagnetic phase and the classical ferromagnetic phase. Two former quantum
+ground states are manifested in zero-temperature magnetization curves as
+intermediate plateaus at zero and one-half of the saturation magnetization,
+whereas the one-half plateau disappears at a triple point induced by a strong
+enough ferromagnetic Ising coupling. The ground-state phase diagram and
+zero-temperature magnetization curves of the analogous spin-1/2 Heisenberg
+branched chain were investigated using DMRG calculations. The latter fully
+quantum Heisenberg model involves, besides two gapful phases manifested as zero
+and one-half magnetization plateaus, gapless quantum spin-liquid phase. The
+intermediate one-half plateau of the spin-1/2 Heisenberg branched chain
+vanishes at Kosterlitz-Thouless quantum critical point between gapful and
+gapless quantum ground states unlike the triple point of the spin-1/2
+Ising-Heisenberg branched chain.",1908.05639v1
+2019-12-23,Fluctuation Dynamo in Collisionless and Weakly Collisional Magnetized Plasmas,"In weakly collisional astrophysical plasmas, such as the intracluster medium
+of galaxy clusters, the amplification of cosmic magnetic fields by chaotic
+fluid motions is hampered by the adiabatic production of magnetic-field-aligned
+pressure anisotropy. This anisotropy drives a viscous stress parallel to the
+field that inhibits the plasma's ability to stretch magnetic-field lines. I
+demonstrate through the use of kinetic simulations that in high-$\beta$
+plasmas, kinetic ion-Larmor scale instabilities sever the adiabatic link
+between the thermal and magnetic pressures, reducing this viscous stress and
+thereby allowing the dynamo to operate. Two distinct regimes of the fluctuation
+dynamo in a magnetized plasma are identified: one in which these instabilities
+efficiently regulate the pressure anisotropy and one in which this regulation
+is imperfect. I elucidate the role of these kinetic instabilities on the plasma
+viscosity and determine how the fields and flows self-organize to allow the
+dynamo to operate in the face of parallel viscous stresses. In the case of
+efficient pressure-anisotropy regulation, the plasma dynamo closely resembles
+its more traditional Pm ~ 1 MHD counterpart. When the regulation is imperfect,
+the dynamo exhibits characteristics remarkably similar to those found in the
+saturated state of the MHD dynamo. A novel set of microphysical closures for
+fluid simulations that bridges these two regimes are constructed, exhibiting
+explosive magnetic-field growth caused by a field-strength-dependent viscosity.
+The dynamos in both collisionless and weakly collisional plasmas are then
+closely compared to each other, revealing substantial differences in how
+sub-parallel viscous motions behave. The former (collisionless) scenario
+experiences a cascade of stretching motions to sub-Larmor scales that lead to
+increasingly fast dynamo as the magnetic Reynolds number is increased.",1912.11072v1
+2020-01-22,Generation of strong magnetic fields in a nascent neutron star accounting for the chiral magnetic effect,"We propose the mean field dynamo model for the generation of strongest
+magnetic fields, $B\sim 10^{15}\,{\rm G}$, in a neutron star (NS) accounting
+for the chiral magnetic effect (CME) driven by the shock in a supernova (SN)
+progenitor of that NS. The temperature jump at a narrow shock front, where an
+initial magnetic field existing in inflowing matter rises sharply, is the
+source of the CME that prevails significantly the erasure of the CME due to the
+spin-flip through Coulomb collisions in plasma. The growth of the magnetic
+field just behind the shock given by the instability term $\nabla\times (\alpha
+{\bf B})$ in induction equation, stops after a successful SN explosion that
+throws out the mantle of a protoneutron star. As a result, such an explosion
+interrupts the transfer of strongly magnetized plasma from the shock onto NS
+surface and leads to the saturation of the magnetic field. Assuming the rigid
+protostar rotation, we employ the mean field dynamo, which is similar to the
+$\alpha^2$-dynamo known in the standard magnetohydrodynamics (MHD). The novelty
+of our model is that $\alpha^2$-dynamo is based on concepts of particle
+physics, applied in MHD, rather than by a mirror asymmetry of convective
+vortices in the rotating convection.",2001.08139v1
+2020-06-05,Sgr A* near-infrared flares from reconnection events in a magnetically arrested disc,"Large-amplitude Sgr A* near-infrared flares result from energy injection into
+electrons near the black hole event horizon. Astrometry data show continuous
+rotation of the emission region during bright flares, and corresponding
+rotation of the linear polarization angle. One broad class of physical flare
+models invokes magnetic reconnection. Here we show that such a scenario can
+arise in a general relativistic magnetohydrodynamic simulation of a
+magnetically arrested disc. Saturation of magnetic flux triggers eruption
+events, where magnetically dominated plasma is expelled from near the horizon
+and forms a rotating, spiral structure. Dissipation occurs via reconnection at
+the interface of the magnetically dominated plasma and surrounding fluid. This
+dissipation is associated with large increases in near-infrared emission in
+models of Sgr A*, with durations and amplitudes consistent with the observed
+flares. Such events occur at roughly the timescale to re-accumulate the
+magnetic flux from the inner accretion disc, 10h for Sgr A*. We study
+near-infrared observables from one sample event to show that the emission
+morphology tracks the boundary of the magnetically dominated region. As the
+region rotates around the black hole, the near-infrared centroid and linear
+polarization angle both undergo continuous rotation, similar to the behavior
+seen in Sgr A* flares.",2006.03657v2
+2020-09-15,Dynamo saturation through the latitudinal variation of bipolar magnetic regions in the Sun,"Observations of the solar magnetic cycle showed that the amplitude of the
+cycle did not grow all the time in the past. Thus, there must be a mechanism to
+halt the growth of the magnetic field in the Sun. We demonstrate a recently
+proposed mechanism for this under the Babcock--Leighton dynamo framework, which
+is believed to be the most promising paradigm for the generation of the solar
+magnetic field at present. This mechanism is based on the observational fact
+that the stronger solar cycles produce bipolar magnetic regions (BMRs) at
+higher latitudes and thus have higher mean latitudes than the weaker ones. We
+capture this effect in our three-dimensional Babcock--Leighton solar dynamo
+model and show that when the toroidal magnetic field tries to grow, it produces
+BMRs at higher latitudes. The BMRs at higher latitudes generate a less poloidal
+field, which consequently limits the overall growth of the magnetic field in
+our model. Thus, our study suggests that the latitudinal variation of BMRs is a
+potential mechanism for limiting the magnetic field growth in the Sun.",2009.06969v2
+2020-12-02,"Synthesis, structure and magnetic properties of honeycomb-layered Li3Co2SbO6 with new data on its sodium precursor, Na3Co2SbO6","Li3Co2SbO6 is prepared by molten salt ion exchange and its structure refined
+by the Rietveld method confirming the honeycomb-type Co/Sb ordering of its Na
+precursor. Monoclinic rather than trigonal symmetry of Na3Co2SbO6 is directly
+demonstrated for the first time by peak splitting in the high-resolution
+synchrotron XRD pattern. The long-range antiferromagnetic order is established
+at TN about 6.7 K and 9.9 K in Na3Co2SbO6 and Li3Co2SbO6, respectively,
+confirmed by both the magnetic susceptibility and specific heat. Spin-wave
+analysis of specific heat data indicates the presence of 3D AFM magnons in
+Na3Co2SbO6 and 2D AFM magnons in Li3Co2SbO6. The field dependence of the
+magnetization almost reaches saturation in moderate magnetic fields up to 9 T
+and demonstrates characteristic features of magnetic field induced
+spin-reorientation transitions for both A3Co2SbO6 (A = Na, Li). Overall
+thermodynamic studies show that the magnetic properties of both compounds are
+very sensitive to an external magnetic field, thus predicting a non-trivial
+ground state with a rich magnetic phase diagram. The ground state spin
+configuration of Li3Co2SbO6 has been determined by low-temperature neutron
+powder diffraction. It represents a ferromagnetic arrangement of moments in the
+honeycomb layers with antiferromagnetic coupling between adjacent layers.",2012.01093v1
+2021-02-28,Flare Activity and Magnetic Feature Analysis of the Flare Stars II: Sub-Giant Branch,"We present an investigation of the magnetic activity and flare
+characteristics of the sub-giant stars mostly from F and G spectral types and
+compare the results with the main-sequence (MS) stars. The light curve of 352
+stars on the sub-giant branch (SGB) from the Kepler mission is analyzed in
+order to infer stability, relative coverage and contrast of the magnetic
+structures and also flare properties using three flare indexes. The results
+show that: (i) Relative coverage and contrast of the magnetic features along
+with rate, power and magnitude of flares increase on the SGB due to the
+deepening of the convective zone and more vigorous magnetic field production
+(ii) Magnetic activity of the F and G-type stars on the SGB does not show
+dependency to the rotation rate and does not obey the saturation regime. This
+is the opposite of what we saw for the main sequence, in which the G-, K- and
+M-type stars show clear dependency to the Rossby number; (iii) The positive
+relationship between the magnetic features stability and their relative
+coverage and contrast remains true on the SGB, though it has lower dependency
+coefficient in comparison with the MS; (iv) Magnetic proxies and flare indexes
+of the SGB stars increase with increasing the relative mass of the convective
+zone.",2103.00478v1
+2021-06-14,Yb delafossites: unique exchange frustration of 4f spin 1/2 moments on a perfect triangular lattice,"While the Heisenberg model for magnetic Mott insulators on planar lattice
+structures is comparatively well understood in the case of transition metal
+ions, the intrinsic spin-orbit entanglement of 4f magnetic ions on such
+lattices shows fascinating new physics largely due to corresponding strong
+anisotropies both in their single-ion and their exchange properties. We show
+here that the Yb delafossites, containing perfect magnetic Yb$^{3+}$ triangular
+lattice planes with pseudospin $s=1/2$ at low temperatures, are an ideal
+platform to study these new phenomena. Competing frustrated interactions may
+lead to an absence of magnetic order associated to a gapless spin liquid ground
+state with a huge linear specific heat exceeding that of many heavy fermions,
+whereas the application of a magnetic field induces anisotropic magnetic order
+with successive transitions into different long ranged ordered structures. In
+this comparative study, we discuss our experimental findings in terms of a
+unified crystal-field and exchange model. We combine electron paramagnetic
+resonance (EPR) experiments and results from neutron scattering with
+measurements of the magnetic susceptibility, isothermal magnetization up to
+full polarization, and specific heat to determine the relevant model
+parameters. The impact of the crystal field is discussed as well as the
+symmetry-compatible form of the exchange tensor, and we give explicit
+expressions for the anisotropic g factor, the temperature dependence of the
+susceptibility, the exchange-narrowed EPR linewidth and the saturation field.",2106.07576v1
+2021-07-23,Intermixing Induced Anisotropy Variations in CoB-based Chiral Multilayer Films,"We examine the atomic intermixing phenomenon in three distinct amorphous
+CoB-based multilayer thin film platforms - Pt/CoB/Ir, Ir/CoB/Pt and Pt/CoB/MgO
+- which are shown to stabilise room-temperature chiral magnetic textures.
+Intermixing occurs predominantly between adjacent metallic layers. Notably, it
+is stack-order dependent, and particularly extensive when Ir sits atop CoB.
+Intermixing induced variations in magnetic properties are ascribed to the
+formation of magnetic dead layer arising from CoIr alloying in the metallic
+stacks. It also produces systematic variations in saturation magnetization, by
+as much as 30%, across stacks. Crucially, the resulting crossover CoB thickness
+for the transition from perpendicular to in-plane magnetic anisotropy differs
+by more than 2x across the stacks. Finally, with thermal annealing treatment
+over moderate temperatures of 150-300 degree Celsius, the magnetic anisotropy
+increases monotonically across all stacks, coupled with discernibly larger Hc
+for the metallic stacks. These are attributed to thermally induced CoPt
+alloying and MgO crystallization in the metallic and oxide stacks,
+respectively. Remarkably, the CoB in the Pt/CoB/MgO stacks retains its
+amorphous nature after annealing. Our results set the stage for harnessing the
+collective attributes of amorphous CoB-based material platforms and associated
+annealing processes for modulating magnetic interactions, enabling the tuning
+of chiral magnetic texture properties in ambient conditions.",2107.11034v1
+2022-03-18,Structural and Magnetic Properties of Pt/Co/Mn-Based Multilayers,"Magnetic multilayers are a rich class of materials systems with numerous
+highly tunable physical parameters that determine both their magnetic and
+electronic properties. Here we present a comprehensive experimental study of a
+novel system, Pt/Co/Mn, which extends the group of Pt/Co/X ($\mathrm{X}=$
+metal) multilayers that have been investigated thus far. We demonstrate that an
+increasing Co layer thickness changes the magnetic anisotropy from out-of-plane
+to in-plane, whereas the deposition of thicker Mn layers leads to a decrease in
+the saturation magnetization. Temperature-dependent magnetometry measurements
+reinforce the hypothesis of antiferromagnetic coupling at the Co/Mn interfaces
+being responsible for the observed Mn thickness dependence of the magnetization
+reversal. Moreover, magneto-optical imaging experiments indicate systematic
+changes in magnetic domain patterns as a function of the Co and Mn layer
+thickness, suggesting the existence of bubble-like domains -- potentially even
+magnetic skyrmions -- in the case of sufficiently thick Mn layers, which are
+expected to contribute to a sizeable Dzyaloshinskii-Moriya interaction in the
+multilayer stacks. We identify Pt/Co/Mn as a highly complex multilayer system
+with strong potential for further fundamental studies and possible
+applications.",2203.10059v2
+2022-05-24,Competing magnetic phases in the frustrated spin-1/2 chain compound $β$-TeVO$_4$ probed by NMR,"In frustrated spin-1/2 chains the competition between the nearest- and
+next-nearest-neighbor exchange interactions leads to a rich phase diagram that
+becomes even richer in the presence of perturbations in their material
+realizations. These effects are still largely unexplored, so that new insight
+into static and dynamic magnetism, in particular by sensitive local probes, is
+highly desired. Here we present a comprehensive $^{17}$O nuclear magnetic
+resonance study of $\beta$-TeVO$_4$, where the anisotropy of the main exchange
+interactions and additional weak interchain exchange interactions complement
+the theoretical phase diagram. Our results confirm the dynamical nature of the
+intriguing spin-stripe phase that has been reported in previous studies. In
+addition, we find that the magnetic order in the high-field phase, which
+develops just below the magnetization saturation, is consistent with an unusual
+type of spin-density-wave (SDW) order with different alignments of the magnetic
+moments on the neighboring chains. This is reminiscent of the ordering in the
+SDW phase, realized in the absence of the magnetic field, and is thus most
+likely stabilized by magnetic anisotropy.",2205.11875v1
+2022-06-02,A mechanically strong and ductile soft magnet with extremely low coercivity,"Soft magnetic materials (SMMs) serve in electrical applications and
+sustainable energy supply, allowing magnetic flux variation in response to
+changes in applied magnetic field, at low energy loss1. The electrification of
+transport, households and manufacturing leads to an increase in energy
+consumption due to hysteresis losses2. Therefore, minimizing coercivity, which
+scales these losses, is crucial3. Yet, meeting this target alone is not enough:
+SMMs in electrical engines must withstand severe mechanical loads, i.e., the
+alloys need high strength and ductility4. This is a fundamental design
+challenge, as most methods that enhance strength introduce stress fields that
+can pin magnetic domains, thus increasing coercivity and hysteretic losses5.
+Here, we introduce an approach to overcome this dilemma. We have designed a
+Fe-Co-Ni-Ta-Al multicomponent alloy with ferromagnetic matrix and paramagnetic
+coherent nanoparticles (~91 nm size, ~55% volume fraction). They impede
+dislocation motion, enhancing strength and ductility. Their small size, low
+coherency and small magnetostatic energy create an interaction volume below the
+magnetic domain wall width, leading to minimal domain wall pinning, thus
+maintaining the soft magnetic properties. The alloy has a tensile strength of
+1336 MPa at 54% tensile elongation, extremely low coercivity of 78 A/m (<1 Oe),
+moderate saturation magnetization of 100 Am2/kg, and high electrical
+resistivity of 103 {\mu}{\Omega} u Ohm cm.",2207.05686v1
+2022-11-10,Field induced non-BEC transitions in frustrated magnets,"Frustrated spin-systems have traditionally proven challenging to understand,
+owing to a scarcity of controlled methods for their analyses. By contrast,
+under strong magnetic fields, certain aspects of spin systems admit simpler and
+universal description in terms of hardcore bosons. The bosonic formalism is
+anchored by the phenomenon of Bose-Einstein condensation (BEC), which has
+helped explain the behaviors of a wide range of magnetic compounds under
+applied magnetic fields. Here, we focus on the interplay between frustration
+and externally applied magnetic field to identify instances where the BEC
+paradigm is no longer applicable. As a representative example, we consider the
+antiferromagnetic $J_1 - J_2 - J_3$ model on the square lattice in the presence
+of a uniform external magnetic field, and demonstrate that the
+frustration-driven suppression of the N\'{e}el order leads to a Lifshitz
+transition for the hardcore bosons. In the vicinity of the Lifshitz point, the
+physics becomes unmoored from the BEC paradigm, and the behavior of the system,
+both at and below the saturation field, is controlled by a Lifshitz
+multicritical point. We obtain the resultant universal scaling behaviors, and
+provide strong evidence for the existence of a frustration and magnetic-field
+driven correlated bosonic liquid state along the entire phase boundary
+separating the N\'{e}el phase from other magnetically ordered states.",2211.05771v3
+2023-01-04,Magnetic properties of the layered heavy fermion antiferromagnet CePdGa$_6$,"We report the magnetic properties of the layered heavy fermion
+antiferromagnet CePdGa$_{6}$, and their evolution upon tuning with the
+application of magnetic field and pressure. CePdGa$_{6}$ orders
+antiferromagnetically below $T\rm_{N}$ = 5.2 K, where there is evidence for
+heavy fermion behavior from an enhanced Sommerfeld coefficient. Our results are
+best explained by a magnetic ground state of ferromagnetically coupled layers
+of Ce $4f$-moments orientated along the $c$-axis, with antiferromagnetic
+coupling between layers. At low temperatures we observe two metamagnetic
+transitions for fields applied along the $c$-axis corresponding to spin-flip
+transitions, where the lower transition is to a different magnetic phase with a
+magnetization one-third of the saturated value. From our analysis of the
+magnetic susceptibility, we propose a CEF level scheme which accounts for the
+Ising anisotropy at low temperatures, and we find that the evolution of the
+magnetic ground state can be explained considering both antiferromagnetic
+exchange between nearest neighbor and next nearest neighbor layers, indicating
+the influence of long-range interactions. Meanwhile we find little change of
+$T\rm_{N}$ upon applying hydrostatic pressures up to 2.2 GPa, suggesting that
+significantly higher pressures are required to examine for possible quantum
+critical behaviors.",2301.01444v1
+2023-03-03,Room-Temperature Magnetic Skyrmions in Pt/Co/Cu Multilayers,"Magnetic skyrmions are promising for next-generation information storage and
+processing owing to their potential advantages in data storage density,
+robustness, and energy efficiency. The magnetic multilayers consisting of Pt,
+Co, and a third metal element $X$ provide an ideal platform to study the
+skyrmions due to their highly tunable magnetic properties. Here, we report the
+observation of room-temperature bubble-like N\'eel skyrmions in epitaxial
+Pt/Co/Cu multilayers in samples with multidomain states in zero field. The
+magneto-optic Kerr effect (MOKE) and superconducting quantum interference
+device (SQUID) magnetometry are applied to investigate the shapes of the
+hysteresis loops, the magnetic anisotropy, and the saturation magnetization. By
+tuning the Co thickness and the number of periods, we achieve perpendicular and
+in-plane magnetized states and multidomain states that are identified by a
+wasp-waisted hysteresis loop. Skyrmions are directly imaged by magnetic force
+microscopy (MFM) and Lorentz transmission electron microscopy (LTEM). The
+development of room-temperature skyrmions in Pt/Co/Cu multilayers may lead to
+advances in skyrmion-related research and applications.",2303.02117v2
+2023-04-29,Evolution of medium-range order and its correlation with magnetic nanodomains in Fe-Dy-B-Nb bulk metallic glasses,"Fe-based metallic glasses are promising functional materials for advanced
+magnetism and sensor fields. Tailoring magnetic performance in amorphous
+materials requires a thorough knowledge of the correlation between structural
+disorder and magnetic order, which remains ambiguous. Two practical
+difficulties remain: the first is directly observing subtle magnetic structural
+changes on multiple scales, and the second is precisely regulating the various
+amorphous states. Here we propose a novel approach to tailor the amorphous
+structure through the liquid liquid phase transition. In-situ synchrotron
+diffraction has unraveled a medium-range ordering process dominated by
+edge-sharing cluster connectivity during the liquid-liquid phase transition.
+Moreover, nanodomains with topological order have been found to exist in
+composition with liquid-liquid phase transition, manifesting as hexagonal
+patterns in small-angle neutron scattering profiles. The liquid-liquid phase
+transition can induce the nanodomains to be more locally ordered, generating
+stronger exchange interactions due to the reduced Fe-Fe bond and the enhanced
+structural order, leading to the increment of saturation magnetization.
+Furthermore, the increased local heterogeneity in the medium range scale
+enhances the magnetic anisotropy, promoting the permeability response under
+applied stress and leading to a better stress-impedance effect. These
+experimental results pave the way to tailor the magnetic structure and
+performance through the liquid-liquid phase transition.",2305.00274v1
+2023-07-16,Long-term variations of the Sun's photospheric magnetic field,"Variations of the weak magnetic fields of the photosphere with periods of the
+order of the solar magnetic cycle were investigated. Synoptic maps of the
+photospheric magnetic field produced by NSO Kitt Peak for the period from 1978
+to 2016 were used as initial data. In order to study weak magnetic fields, the
+saturation threshold for synoptic maps was set at 5 G. On the base of
+transformed synoptic maps the time-latitude chart was built. 18 profiles of the
+magnetic field evenly distributed along the sine of latitude from the north to
+the south pole were selected in the diagram for the further analysis. Time
+dependencies were averaged by sliding smoothing over 21 Carrington rotations.
+The approximation of averaged time dependencies by the sinusoidal function made
+it possible to distinguish in weak magnetic fields a cyclic component with a
+period of about 22 years (the period of the Hale magnetic cycle). The
+dependence of 22-year variation on latitude was studied. In addition to the
+well-known 22-year change in the near-polar field, similar variations were
+found for the fields at all latitudes. The exception was latitudes $26^\circ$
+and $33^\circ$ in the northern and $26^\circ$ in the southern hemisphere. These
+mid-latitude intervals were characterized by a predominance of short-period
+variations. The amplitude of the long-term variation decreased from the poles
+to the equator, with the period of variation remaining almost constant (T =
+22.3 years).",2307.08009v1
+2023-08-28,Magnetic kagome materials RETi3Bi4 family with weak interlayer interactions,"Kagome materials have attracted a surge of research interest recently,
+especially for the ones combining with magnetism, and the ones with weak
+interlayer interactions which can fabricate thin devices. However, kagome
+materials combining both characters of magnetism and weak interlayer
+interactions are rare. Here we investigate a new family of titanium based
+kagome materials RETi3Bi4 (RE = Eu, Gd and Sm). The flakes of nanometer
+thickness of RETi3Bi4 can be obtained by exfoliation due to the weak interlayer
+interactions. According to magnetic measurements, out-of-plane ferromagnetism,
+out-of-plane anti-ferromagnetism, and in-plane ferromagnetism are formed for RE
+= Eu, Gd, and Sm respectively. The magnetic orders are simple and the
+saturation magnetizations can be relatively large since the rare earth elements
+solely provide the magnetic moments. Further by angle-resolved photoemission
+spectroscopy (ARPES) and first-principles calculations, the electronic
+structures of RETi3Bi4 are investigated. The ARPES results are consistent with
+the calculations, indicating the bands characteristic with kagome sublattice in
+RETi3Bi4. We expect these materials to be promising candidates for observation
+of the exotic magnetic topological phases and the related topological quantum
+transport studies.",2308.14509v1
+2023-12-01,Magnetic phase diagram and magneto-elastic coupling of NdB$_4$ studied by high-resolution capacitance dilatometry up to 35~T,"We report high-resolution dilatometry studies on single crystals of the
+Shastry-Sutherland-lattice magnet NdB$_4$ supported by specific heat and
+magnetometry data. Our dilatometric studies evidence pronounced anomalies at
+the phase boundaries which imply strong magneto-elastic coupling. The evolution
+of the three zero-field phase transitions separating distinct antiferromagnetic
+phases at $TN=17.2$~K, $TIT=6.8$~K and $TLT=4.8$~K can thus be traced in
+applied magnetic fields which provides the magnetic phase diagrams for
+$B\parallel c$ up to 15~T and for $B\parallel [110]$ up to 35~T. New in-field
+phases are discovered for both field directions and already known phases are
+confirmed. In particular, phase boundaries between different phases are
+unambiguously shown by sign changes of observed anomalies and corresponding
+changes in uniaxial pressure effects. For $B||c$, we find a 1/4-magnetization
+plateau in addition to a previously reported plateau at 1/5 of the saturation
+magnetization. TN increases for $B\parallel c$ in fields up to 15~T implying
+that magnetic moments of the all-in/all-out structure in the high temperature
+AFM ordered phase are driven towards the $c$ axis in high magnetic fields.
+Uniaxial pressure dependencies
+${\partial}T_{\mathrm{crit}}/{\partial}p_{\mathrm{c}}$ of the phase transition
+temperatures for magnetic fields and pressure applied along the $c$ axis are
+derived from the data.",2312.00715v1
+2024-03-25,Stellar Spin Down in Post-Mass Transfer Binary Systems,"Motivated by measurements of the rotation speed of accretor stars in
+post-mass-transfer (post-MT) systems, we investigate how magnetic braking
+affects the spin-down of individual stars during binary evolution with the
+\texttt{MESAbinary} module. Unlike the conventional assumption of tidal
+synchronization coupled with magnetic braking in binaries, we first calculate
+whether tides are strong enough to synchronize the orbit. Subsequently, this
+influences the spin-down of stars and the orbital separation. In this study, we
+apply four magnetic braking prescriptions to reduce the spin angular momentum
+of the two stars throughout the entire binary evolution simulation. Our
+findings reveal that despite magnetic braking causing continuous spin-down of
+the accretor, when the donor begins to transfer material onto the accretor, the
+accretor can rapidly spin up to its critical rotation rate. After MT, magnetic
+braking becomes more important in affecting the angular momentum evolution of
+the stars. Post-MT accretor stars thus serve as a valuable testbed for
+observing how the magnetic braking prescriptions operate in spinning down stars
+from their critical rotation, including the saturation regimes of the magnetic
+braking. The rotation rate of the accretor star, combined with its mass, could
+provide age information since the cessation of MT. By comparing the models
+against observation, the magnetic braking prescription by Garraffo et al.
+(2018b) is found to better align with the rotation data of post-MT accretors.",2403.17279v1
+2004-08-27,Progress in Anisotropic Plasma Physics,"In 1959 Weibel demonstrated that when a QED plasma has a temperature
+anisotropy there exist unstable transverse magnetic excitations which grow
+exponentially fast. In this paper we will review how to determine the growth
+rates for these unstable modes in the weak-coupling and ultrarelativistic
+limits in which the collective behavior is describable in terms are so-called
+""hard-loops"". We will show that in this limit QCD is subject to instabilities
+which are analogous to the Weibel instability in QED. The presence of such
+instabilities dominates the early time evolution of a highly anisotropic
+plasma; however, at longer times it is expected that these instabilities will
+saturate (condense). I will discuss how the presence of non-linear interactions
+between the gluons complicates the determination of the saturated state. In
+order to discuss this I present the generalization of the Braaten-Pisarski
+isotropic hard-thermal-loop effective action to a system with a temperature
+anisotropy in the parton distribution functions. The resulting hard-loop
+effective action can be used to determine the time and energy scales associated
+with the possible saturation (condensation) of the gluonic modes. We will also
+discuss the effects of anisotropies on observables, in particular on the heavy
+quark energy loss.",0408314v2
+2014-02-26,Anomalous temperature dependence of current induced torques in CoFeB|MgO heterostructures with Ta based underlayers,"We have studied the underlayer thickness and temperature dependences of the
+current induced effective field in CoFeB|MgO heterostructures with Ta based
+underlayers. The underlayer thickness at which the effective field saturates is
+found to be different between the two orthogonal components of the effective
+field, i.e. the damping-like term tends to saturate at smaller underlayer
+thickness than the field-like term. For large underlayer thickness films in
+which the effective field saturates, we find that the temperature significantly
+influences the size of the effective field. A striking difference is found in
+the temperature dependence of the two components: the damping-like term
+decreases whereas the field-like term increases with increasing temperature.
+Using a simple spin diffusion-spin transfer model, we find that all of these
+results can be accounted for provided the real and imaginary parts of an
+effective spin mixing conductance are negative. These results imply that either
+spin transport in this system is different from conventional metallic
+interfaces or effects other spin diffusion into the magnetic layer need to be
+taken account in order to model the system accurately.",1402.6388v1
+2017-03-07,MHD modeling of a DIII-D low-torque QH-mode discharge and comparison to observations,"Extended-MHD modeling of DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614
+(2002)] quiescent H-mode (QH-mode) discharges with nonlinear NIMROD [C. R.
+Sovinec et al., J. Comput. Phys. 195, 355 (2004)] simulations saturates into a
+turbulent state but does not saturate when the steady-state flow inferred from
+measurements is not included. This is consistent with the experimental
+observations of the quiescent regime on DIII-D. The simulation with flow
+develops into a saturated turbulent state where the n=1 and 2 toroidal modes
+become dominant through an inverse cascade. Each mode in the range of n=1-5 is
+dominant at a different time. Consistent with experimental observations during
+QH-mode, the simulated state leads to large particle transport relative to the
+thermal transport. Analysis shows that the amplitude and phase of the density
+and temperature perturbations differ resulting in greater fluctuation-induced
+convective particle transport relative to the convective thermal transport.
+Comparison to magnetic-coil measurements shows that rotation frequencies differ
+between the simulation and experiment, which indicates that more sophisticated
+extended-MHD two-fluid modeling is required.",1703.02584v1
+2018-03-30,Quasi-linear Transport in a Sheared Flow Field,"The evolution of a passive scalar field is considered for a slowly varying
+stratified medium, which is convected in an incompressible sheared flow with
+many overlapping static flux islands. Within the quasilinear/random phase
+approximation, a multiple scale expansion is made. Due to the rapid spatial
+variation of the temperature, the ""ensemble"" averaged/ slowly varying part of
+the solution is not described by the arithmetic average of the oscillatory
+evolution equation. The standard Markovian and continuum approximations are
+shown to be invalid. For times of order $N$, where there are $O(N^2)$ excited
+modes, most of the time dependent perturbation phase mixes away and the fluid
+reaches a new saturated state with small time oscillations about the
+temperature. This saturated state has smaller resonance layers, (corresponding
+to magnetic islands) than those that occur in the isolated resonant
+perturbation case. Thus the quasilinear response to the resonant interactions
+reduces the effective size of the perturbations. The temperature gradient of
+the saturated state vanishes at all the excited resonance surfaces but has a
+nonzero average. Thus either the quasi-linear approximation ceases to be valid
+on long time scales, or the fluid remains essentially in this modified
+equilibrium and does not evolve diffusively. Thus collisionless, driftless fast
+particles will not be lost rapidly in equilibria with many small islands.",1804.00042v1
+2018-04-13,Tuning Rashba Spin-Orbit Coupling in Gated Multilayer InSe,"Manipulating the electron spin with the aid of spin-orbit coupling (SOC) is
+an indispensable element of spintronics. Electrostatically gating a material
+with strong SOC results in an effective magnetic field which can in turn be
+used to govern the electron spin. In this work, we report the existence and
+electrostatic tunability of Rashba SOC in multilayer InSe. We observed a
+gate-voltage-tuned crossover from weak localization (WL) to weak
+antilocalization (WAL) effect in quantum transport studies of InSe, which
+suggests an increasing SOC strength. Quantitative analyses of magneto-transport
+studies and energy band diagram calculations provide strong evidence for the
+predominance of Rashba SOC in electrostatically gated InSe. Furthermore, we
+attribute the tendency of the SOC strength to saturate at high gate voltages to
+the increased electronic density of states-induced saturation of the electric
+field experienced by the electrons in the InSe layer. This explanation of
+nonlinear gate voltage control of Rashba SOC can be generalized to other
+electrostatically gated semiconductor nanomaterials in which a similar tendency
+of spin-orbit length saturation was observed (e.g. nanowire field effect
+transistors), and is thus of broad implications in spintronics. Identifying and
+controlling the Rashba SOC in InSe may serve pivotally in devising III-VI
+semiconductor-based spintronic devices in the future.",1804.04992v2
+2020-04-08,Zonally dominated dynamics and Dimits threshold in curvature-driven ITG turbulence,"The saturated state of turbulence driven by the ion-temperature-gradient
+instability is investigated using a two-dimensional long-wavelength fluid model
+that describes the perturbed electrostatic potential and perturbed ion
+temperature in a magnetic field with constant curvature (a $Z$-pinch) and an
+equilibrium temperature gradient. Numerical simulations reveal a well-defined
+transition between a finite-amplitude saturated state dominated by strong
+zonal-flow and zonal-temperature perturbations, and a blow-up state that fails
+to saturate on a box-independent scale. We argue that this transition is
+equivalent to the Dimits transition from a low-transport to a high-transport
+state seen in gyrokinetic numerical simulations. A quasi-static staircase-like
+structure of the temperature gradient intertwined with zonal flows, which have
+patch-wise constant shear, emerges near the Dimits threshold. The turbulent
+heat flux in the low-collisionality near-marginal state is dominated by
+turbulent bursts, triggered by coherent long-lived structures closely
+resembling those found in gyrokinetic simulations with imposed equilibrium flow
+shear. The break up of the low-transport Dimits regime is linked to a
+competition between the two different sources of poloidal momentum in the
+system -- the Reynolds stress and the advection of the diamagnetic flow by the
+$\boldsymbol{E}\times\boldsymbol{B}$ flow. By analysing the linear ITG modes,
+we obtain a semi-analytic model for the Dimits threshold at large
+collisionality.",2004.04047v2
+2021-12-18,Magnetograph Saturation and the Open Flux Problem,"Extrapolations of line-of-sight photospheric field measurements predict
+radial interplanetary magnetic field (IMF) strengths that are factors of ~2--4
+too low. To address this ""open flux problem,'' we reanalyze the magnetograph
+measurements from different observatories, with particular focus on those made
+in the saturation-prone Fe I 525.0 nm line by the Mount Wilson Observatory
+(MWO) and the Wilcox Solar Observatory (WSO). The total dipole strengths, which
+determine the total open flux, generally show large variations among
+observatories, even when their total photospheric fluxes are in agreement.
+However, the MWO and WSO dipole strengths, as well as their total fluxes, agree
+remarkably well with each other, suggesting that the two data sets require the
+same scaling factor. As shown earlier by Ulrich et al., the saturation
+correction $\delta^{-1}$ derived by comparing MWO measurements in the 525.0 nm
+line with those in the nonsaturating Fe I 523.3 nm line depends sensitively on
+where along the irregularly shaped 523.3 nm line wings the exit slits are
+placed. If the slits are positioned so that the 523.3 and 525.0 nm signals
+originate from the same height, $\delta^{-1}$ ~ 4.5 at disk center, falling to
+~2 near the limb. When this correction is applied to either the MWO or WSO
+maps, the derived open fluxes are consistent with the observed IMF magnitude.
+Other investigators obtained scaling factors only one-half as large because
+they sampled the 523.3 nm line farther out in the wings, where the shift
+between the right- and left-circularly polarized components is substantially
+smaller.",2112.09969v1
+2023-03-31,Particle-In-Cell Simulations of Sunward and Anti-sunward Whistler Waves in the Solar Wind,"Spacecraft observations showed that electron heat conduction in the solar
+wind is probably regulated by whistler waves, whose origin and efficiency in
+electron heat flux suppression is actively investigated. In this paper, we
+present Particle-In-Cell simulations of a combined whistler heat flux and
+temperature anisotropy instability that can operate in the solar wind. The
+simulations are performed in a uniform plasma and initialized with core and
+halo electron populations typical of the solar wind. We demonstrate that the
+instability produces whistler waves propagating both along (anti-sunward) and
+opposite (sunward) to the electron heat flux. The saturated amplitudes of both
+sunward and anti-sunward whistler waves are strongly correlated with their {\it
+initial} linear growth rates, $B_{w}/B_0\sim (\gamma/\omega_{ce})^{\nu}$, where
+for typical electron betas we have $0.6\lesssim \nu\lesssim 0.9$. The
+correlations of whistler wave amplitudes and spectral widths with plasma
+parameters (electron beta and temperature anisotropy) revealed in the
+simulations are consistent with those observed in the solar wind. The
+efficiency of electron heat flux suppression is positively correlated with the
+saturated amplitude of sunward whistler waves. The electron heat flux can be
+suppressed by 10--60% provided that the saturated amplitude of sunward whistler
+waves exceeds about 1% of background magnetic field. Other experimental
+applications of the presented results are discussed.",2303.18214v1
+2023-06-27,Gyrokinetic theory of toroidal Alfvén eigenmode saturation via nonlinear wave-wave coupling,"Nonlinear wave-wave coupling constitutes an important route for the
+turbulence spectrum evolution in both space and laboratory plasmas. For
+example, in a reactor relevant fusion plasma, a rich spectrum of symmetry
+breaking shear Alfv\'en wave (SAW) instabilities are expected to be excited by
+energetic fusion alpha particles, and self-consistently determine the anomalous
+alpha particle transport rate by the saturated electromagnetic perturbations.
+In this work, we will show that the nonlinear gyrokinetic theory is a necessary
+and powerful tool in qualitatively and quantitatively investigating the
+nonlinear wave-wave coupling processes. More specifically, one needs to employ
+the gyrokinetic approach in order to account for the breaking of the ``pure
+Alfv\'enic state"" in the short wavelength kinetic regime, due to the short
+wavelength structures associated with nonuniformity intrinsic to magnetically
+confined plasmas.
+  Using well-known toroidal Alfv\'en eigenmode (TAE) as a paradigm case, three
+nonlinear wave-wave coupling channels expected to significantly influence the
+TAE nonlinear dynamics are investigated to demonstrate the strength and
+necessity of nonlinear gyrokinetic theory in predicting crucial processes in a
+future reactor burning plasma. These are: 1. the nonlinear excitation of
+meso-scale zonal field structures via modulational instability and TAE
+scattering into short-wavelength stable domain; 2. the TAE frequency cascading
+due to nonlinear ion induced scattering and the resulting saturated TAE
+spectrum; and 3. the cross-scale coupling of TAE with micro-scale ambient drift
+wave turbulence and its effect on TAE regulation and anomalous electron
+heating.",2306.15579v1
+2024-01-05,Effects of multi-dimensionality and energy exchange on electrostatic current-driven plasma instabilities and turbulence,"Large-amplitude current-driven plasma instabilities, which can transition to
+the Buneman instability, were observed in one-dimensional (1D) simulations to
+generate high-energy backstreaming ions. We investigate the saturation of
+multi-dimensional plasma instabilities and its effects on energetic ion
+formation. Such ions directly impact spacecraft thruster lifetimes and are
+associated with magnetic reconnection and cosmic ray inception. An Eulerian
+Vlasov--Poisson solver employing the grid-based direct kinetic method is used
+to study the growth and saturation of 2D2V collisionless, electrostatic
+current-driven instabilities spanning two dimensions each in the configuration
+(D) and velocity (V) spaces supporting ion and electron phase-space transport.
+Four stages characterise the electric potential evolution in such
+instabilities: linear modal growth, harmonic growth, accelerated growth via
+quasi-linear mechanisms alongside non-linear fill-in, and saturated turbulence.
+Its transition and isotropisation process bears considerable similarities to
+the development of hydrodynamic turbulence. While a tendency to isotropy is
+observed in the plasma waves, followed by electron and then ion phase space
+after several ion-acoustic periods, the formation of energetic backstreaming
+ions is more limited in the 2D2V than in the 1D1V simulations. Plasma waves
+formed by two-dimensional electrostatic kinetic instabilities can propagate in
+the direction perpendicular to the net electron drift. Thus, large-amplitude
+multi-dimensional waves generate high-energy transverse-streaming ions and
+eventually limit energetic backward-streaming ions along the longitudinal
+direction. The multi-dimensional study sheds light on interactions between
+longitudinal and transverse electrostatic plasma instabilities, as well as
+fundamental characteristics of the inception and sustenance of unmagnetised
+plasma turbulence.",2401.05428v1
+2006-08-08,Comparison of Magnetic Field Structures on Different Scales in and around the Filamentary Dark Cloud GF 9,"New visible polarization data combined with existing IR and FIR polarization
+data are used to study how the magnetic field threading the filamentary
+molecular cloud GF 9 connects to larger structures in its general environment.
+We find that when both visible and NIR polarization data are plotted as a
+function of extinction, there is no evidence for a plateau or a saturation
+effect in the polarization at Av ~ 1.3 as seen in dark clouds in Taurus. This
+lack of saturation effect suggests that even in the denser parts of GF 9 we are
+still probing the magnetic field. The visible polarization is smooth and has a
+well-defined orientation. The IR data are also well defined but with a
+different direction, and the FIR data in the core region are well defined and
+with yet another direction, but are randomly distributed in the filament
+region. On the scale of a few times the mean radial dimension of the molecular
+cloud, it is as if the magnetic field were `blind' to the spatial distribution
+of the filaments while on smaller scales within the cloud, in the core region
+near the IRAS point source PSC 20503+6006, polarimetry shows a rotation of the
+magnetic field lines in these denser phases. Hence, in spite of the fact that
+the spatial resolution is not the same in the visible/NIR and in the FIR data,
+all the data put together indicate that the field direction changes with the
+spatial scale. Finally, the Chandrasekhar and Fermi method is used to evaluate
+the magnetic field strength, indicating that the core region is approximately
+magnetically critical. A global interpretation of the results is that in the
+core region an original poloidal field could have been twisted by a rotating
+elongated (core+envelope) structure. There is no evidence for turbulence and
+ambipolar diffusion does not seem to be effective at the present time.",0608188v1
+2008-06-03,Euler-Lagrange models with complex currents of three-phase electrical machines and observability issues,"A new Lagrangian formulation with complex currents is developed and yields a
+direct and simple method for modeling three-phase permanent-magnet and
+induction machines. The Lagrangian is the sum a mechanical one and of a
+magnetic one. This magnetic Lagrangian is expressed in terms of rotor angle,
+complex stator and rotor currents. A complexification procedure widely used in
+quantum electrodynamic is applied here in order to derive the Euler-Lagrange
+equations with complex stator and rotor currents. Such complexification process
+avoids the usual separation into real and imaginary parts and simplifies
+notably the calculations. Via simple modifications of such magnetic Lagrangians
+we derive new dynamical models describing permanent-magnet machines with both
+saturation and saliency, and induction machines with both magnetic saturation
+and space harmonics. For each model we also provide its Hamiltonian thus its
+magnetic energy. This energy is also expressed with complex currents and can be
+directly used in Lyapunov and/or passivity based control. Further, we briefly
+investigate the observability of this class of Euler-Lagrange models, in the
+so-called sensorless case when the measured output is the stator current and
+the load torque is constant but unknown. For all the dynamical models obtained
+via such variational principles, we prove that their linear tangent systems are
+unobservable around a one-dimensional family of steady-states attached to the
+same constant stator voltage and current. This negative result explains why
+sensorless control of three-phase electrical machines around zero stator
+frequency remains yet a difficult control problem.",0806.0387v4
+2012-10-24,Local Study of Accretion Disks with a Strong Vertical Magnetic Field: Magnetorotational Instability and Disk Outflow,"We perform 3D vertically-stratified local shearing-box ideal MHD simulations
+of the magnetorotational instability (MRI) that include a net vertical magnetic
+flux, which is characterized by beta_0 (ratio of gas pressure to magnetic
+pressure of the net vertical field at midplane). We have considered
+beta_0=10^2, 10^3 and 10^4 and in the first two cases the most unstable linear
+MRI modes are well resolved in the simulations. We find that the behavior of
+the MRI turbulence strongly depends on beta_0: The radial transport of angular
+momentum increases with net vertical flux, achieving alpha=0.08 for beta_0=10^4
+and alpha>1.0 for beta_0=100, where alpha is the Shakura-Sunyaev parameter. A
+critical value lies at beta_0=10^3: For beta_0>10^3, the disk consists of a gas
+pressure dominated midplane and a magnetically dominated corona. The turbulent
+strength increases with net flux, and angular momentum transport is dominated
+by turbulent fluctuations. The magnetic dynamo that leads to cyclic flips of
+large-scale fields still exists, but becomes more sporadic as net flux
+increases. For beta_0<10^3, the entire disk becomes magnetic dominated. The
+turbulent strength saturates, and the magnetic dynamo is quenched. Stronger
+large-scale fields are generated with increasing net flux, which dominates
+angular momentum transport. A strong outflow is launched from the disk by the
+magnetocentrifugal mechanism, and the mass flux increases linearly with net
+vertical flux and shows sign of saturation at beta_0=10^2. However, the outflow
+is unlikely to be directly connected to a global wind: for beta_0>10^3, the
+large-scale field has no permanent bending direction due to dynamo activities,
+while for beta_0<10^3, the outflows from the top and bottom sides of the disk
+bend towards opposite directions, inconsistent with a physical disk wind
+geometry. Global simulations are needed to address the fate of the outflow.",1210.6661v2
+2013-01-18,The small-scale dynamo: Breaking universality at high Mach numbers,"(Abridged) The small-scale dynamo may play a substantial role in magnetizing
+the Universe under a large range of conditions, including subsonic turbulence
+at low Mach numbers, highly supersonic turbulence at high Mach numbers and a
+large range of magnetic Prandtl numbers Pm, i.e. the ratio of kinetic viscosity
+to magnetic resistivity. Low Mach numbers may in particular lead to the
+well-known, incompressible Kolmogorov turbulence, while for high Mach numbers,
+we are in the highly compressible regime, thus close to Burgers turbulence. In
+this study, we explore whether in this large range of conditions, a universal
+behavior can be expected. Our starting point are previous investigations in the
+kinematic regime. Here, analytic studies based on the Kazantsev model have
+shown that the behavior of the dynamo depends significantly on Pm and the type
+of turbulence, and numerical simulations indicate a strong dependence of the
+growth rate on the Mach number of the flow. Once the magnetic field saturates
+on the current amplification scale, backreactions occur and the growth is
+shifted to the next-larger scale. We employ a Fokker-Planck model to calculate
+the magnetic field amplification during the non-linear regime, and find a
+resulting power-law growth that depends on the type of turbulence invoked. For
+Kolmogorov turbulence, we confirm previous results suggesting a linear growth
+of magnetic energy. For more general turbulent spectra, where the turbulent
+velocity v_t scales with the characteristic length scale as u_\ell\propto
+\ell^{\vartheta}, we find that the magnetic energy grows as
+(t/T_{ed})^{2\vartheta/(1-\vartheta)}, with t the time-coordinate and T_{ed}
+the eddy-turnover time on the forcing scale of turbulence. For Burgers
+turbulence, \vartheta=1/2, a quadratic rather than linear growth may thus be
+expected, and a larger timescale until saturation is reached.",1301.4371v1
+2014-10-01,Search for a spin-nematic phase in the quasi-one-dimensional frustrated magnet LiCuVO$_4$,"We have performed NMR experiments on the quasi one-dimensional frustrated
+spin-1/2 system LiCuVO$_4$ in magnetic fields $H$ applied along the c-axis up
+to field values near the saturation field $H_{\rm sat}$. For the field range
+$H_{\rm c2}<H<H_{\rm c3}$ ($\mu_0H_{\rm c2}\approx 7.5$T and $\mu_0H_{\rm c3} =
+[40.5 \pm 0.2]$T) the $^{51}$V NMR spectra at $T$ = 380mK exhibit a
+characteristic double-horn pattern, as expected for a spin-modulated phase in
+which the magnetic moments of Cu$^{2+}$ ions are aligned parallel to the
+applied field $H$ and their magnitudes change sinusoidally along the magnetic
+chains. For higher fields, the $^{51}$V NMR spectral shape changes from the
+double-horn pattern into a single Lorentzian line. For this Lorentzian line,
+the internal field at the $^{51}$V nuclei stays constant for $\mu_0 H > 41.4$T,
+indicating that the majority of magnetic moments in LiCuVO$_4$ are already
+saturated in this field range. This result is inconsistent with the previously
+observed linear field dependence of the magnetization $M(H)$ for $H_{\rm
+c3}<H<H_{\rm sat}$ with $\mu_0H_{\rm sat}=45$T [L. E. Svistov {\it et al}.,
+JETP Letters {\bf 93}, 21 (2011)]. We argue that the discrepancy is due to
+non-magnetic defects in the samples. The results of the spin-lattice relaxation
+rate of $^7$Li nuclei indicate an energy gap which grows with field twice as
+fast as the Zeeman energy of a single spin, therefore, suggesting that the
+two-magnon bound state is the lowest energy excitation. The energy gap tends to
+close at $\mu_0H \approx 41$T. Our results suggest that the theoretically
+predicted spin-nematic phase, if it exists in LiCuVO$_4$, can be established
+only within the narrow field range $40.5 < \mu_0 H < 41.4$T .",1410.0160v1
+2019-10-16,The rotation angle distribution underlying magnetic field fluctuations in the 1/f range of solar wind turbulent spectra,"We discuss properties of large amplitude magnetic field fluctuations during
+fast Alfvenic solar wind streams, focussing on the statistics of the rotation
+angle between consecutive magnetic field vector measurements for different
+scales in the plasma. Since in the fast solar wind fluctuations preserve the
+modulus of the magnetic field to a good approximation, the tip of the magnetic
+field vector is observed to move on a sphere of approximately constant radius
+|B|. We then compare statistics of solar wind measurements with that of a
+simple model of a random walk bounded on a spherical surface. The analogy
+consists in the fact that in both systems the geometrical constraint imposes a
+limiting amplitude at large separations and thus introduces a break scale in
+the power spectrum of the fluctuations, leading to a shallower slope for scales
+where the fluctuations amplitude becomes scale-independent. However, while in
+the case of the random walk the saturation of the fluctuations occurs when the
+pattern becomes uniform on the sphere (flat distribution of the cosine of the
+rotation angle), transitioning then to a white noise regime, in the solar wind
+magnetic field fluctuations saturate in amplitude maintaining a preferential
+direction. We suggest that this behaviour is due to the presence of the
+background interplanetary magnetic field, which keeps some long-range memory in
+the system also when the fluctuations becomes independent of the scale. This
+long-range correlation is a necessary ingredient in order to produce the 1/f
+spectrum observed at large scales in the solar wind.",1910.07285v1
+2020-03-21,Fluctuation dynamo in a weakly collisional plasma,"The turbulent amplification of cosmic magnetic fields depends upon the
+material properties of the host plasma. In many hot, dilute astrophysical
+systems, such as the intracluster medium (ICM) of galaxy clusters, the rarity
+of particle--particle collisions allows departures from local thermodynamic
+equilibrium. These departures exert anisotropic viscous stresses on the plasma
+motions that inhibit their ability to stretch magnetic-field lines. We present
+a numerical study of the fluctuation dynamo in a weakly collisional plasma
+using magnetohydrodynamic (MHD) equations endowed with a field-parallel viscous
+(Braginskii) stress. When the stress is limited to values consistent with a
+pressure anisotropy regulated by firehose and mirror instabilities, the
+Braginskii-MHD dynamo largely resembles its MHD counterpart. If instead the
+parallel viscous stress is left unabated -- a situation relevant to recent
+kinetic simulations of the fluctuation dynamo and to the early stages of the
+dynamo in a magnetized ICM -- the dynamo changes its character, amplifying the
+magnetic field while exhibiting many characteristics of the saturated state of
+the large-Prandtl-number (${\rm Pm}\gtrsim{1}$) MHD dynamo. We construct an
+analytic model for the Braginskii-MHD dynamo in this regime, which successfully
+matches magnetic-energy spectra. A prediction of this model, confirmed by our
+simulations, is that a Braginskii-MHD plasma without pressure-anisotropy
+limiters will not support a dynamo if the ratio of perpendicular and parallel
+viscosities is too small. This ratio reflects the relative allowed rates of
+field-line stretching and mixing, the latter of which promotes resistive
+dissipation of the magnetic field. In all cases that do exhibit a dynamo, the
+generated magnetic field is organized into folds that persist into the
+saturated state and bias the chaotic flow to acquire a scale-dependent spectral
+anisotropy.",2003.09760v2
+2023-04-24,Vorticity and magnetic dynamo from subsonic expansion waves,"This work concentrates on the effect of an irrotational forcing on a
+magnetized flow in the presence of rotation, baroclinicity, shear, or a
+combination of them. By including magnetic field in the model we can evaluate
+the occurrence of dynamo on both small and large scales. We aim at finding what
+are the minimum ingredients needed to trigger a dynamo instability and what is
+the relation between dynamo and the growth of vorticity.
+  We use the Pencil code to run resistive MHD direct numerical simulations. We
+report no dynamo in all cases where only rotation is included, regardless on
+the equation of state. Conversely, the inclusion of a background sinusoidal
+shearing profile leads to an hydrodynamic instability that produces an
+exponential growth of the vorticity at all scales, starting from small ones.
+This is know as vorticity dynamo. The onset of this instability occurs after a
+rather long temporal evolution of several thousand turbulent turnover times.
+The vorticity dynamo in turn drives an exponential growth of the magnetic
+field, first at small scales, then also at large one. The instability then
+saturates and the magnetic field approximately reaches equipartition with the
+turbulent kinetic energy. During the saturation phase we can observe a winding
+of the magnetic field in the direction of the shearing flow. By varying the
+intensity of the shear we see that the growth rates of this instability change.
+The inclusion of the baroclinic term delays the onset of the vorticity dynamo
+but leads to a more rapid growth.
+  We demonstrate how in the presence of shear, even a purely irrotational
+forcing amplifies the field to equipartition. At the same time, we confirm how
+this forcing alone does not lead to vorticity nor magnetic field growth, and
+this picture does not change in the presence of rotation or baroclinicity up to
+$256^3$ meshpoints.",2304.11929v2
+2003-08-20,Magnetic Braking Revisited,"We present a description for the angular momentum loss rate due to magnetic
+braking for late type stars taking into account recent observational data on
+the relationship between stellar activity and rotation. The analysis is based
+on an idealized two component coronal model subject to constraints imposed on
+the variation of the coronal gas density with rotation period inferred from the
+observed variation of X-ray luminosity, L_x, with rotation rate, Omega, (L_x
+\propto Omega^2) for single rotating dwarfs. An application of the model to
+high rotation rates leads to a gradual turnover of the X-ray luminosity which
+is similar to the saturation recently observed in rapidly rotating dwarfs. The
+resulting angular momentum loss rate, \dot J, depends on Omega in the form \dot
+J \propto Omega^beta where beta ~ 3 for slow rotators and ~ 1.3 for fast
+rotators. The relation at high rotation rates significantly differs from the
+power law exponent for slowly rotating stars, depressing the angular momentum
+loss rate without necessarily requiring the saturation of the magnetic field.
+The application of this model to the evolution of cataclysmic variable binary
+systems leads to mass transfer rates that are in approximate accord with those
+observed in comparison to rates based on either a Skumanich law or an empirical
+law based on beta=1.",0308361v1
+2005-08-30,A further 'degree of freedom' in the rotational evolution of stars,"Observational and theoretical investigations provide evidence for non-uniform
+spot and magnetic flux distributions on rapidly rotating stars, which have a
+significant impact on their angular momentum loss rate through magnetised
+winds. Supplementing the formalism of MacGregor & Brenner (1991) with a
+latitude-dependent magnetised wind model, we analyse the effect of analytically
+prescribed surface distributions of open magnetic flux with different shapes
+and degrees of non-uniformity on the rotational evolution of a solar-like star.
+The angular momentum redistribution inside the star is treated in a qualitative
+way, assuming an angular momentum transfer between the rigidly-rotating
+radiative and convective zones on a constant coupling timescale of 15 Myr; for
+the sake of simplicity we disregard interactions with circumstellar disks. We
+find that non-uniform flux distributions entail rotational histories which
+differ significantly from those of classical approaches, with differences
+cumulating up to 200% during the main sequence phase. Their impact is able to
+mimic deviations of the dynamo efficiency from linearity of up to 40% and
+nominal dynamo saturation limits at about 35 times the solar rotation rate.
+Concentrations of open magnetic flux at high latitudes thus assist in the
+formation of very rapidly rotating stars in young open clusters, and ease the
+necessity for a dynamo saturation at small rotation rates. However, since our
+results show that even minor amounts of open flux at intermediate latitudes, as
+observed with Zeeman-Doppler imaging techniques, are sufficient to moderate
+this reduction of the AM loss rate, we suggest that non-uniform flux
+distributions are a complementary rather than an alternative explanation for
+very rapid stellar rotation.",0508643v1
+2003-06-13,Structural and doping effects in the half-metallic double perovskite $A_2$CrWO$_6$,"he structural, transport, magnetic and optical properties of the double
+perovskite $A_2$CrWO$_6$ with $A=\text{Sr, Ba, Ca}$ have been studied. By
+varying the alkaline earth ion on the $A$ site, the influence of steric effects
+on the Curie temperature $T_C$ and the saturation magnetization has been
+determined. A maximum $T_C=458$ K was found for Sr$_2$CrWO$_6$ having an almost
+undistorted perovskite structure with a tolerance factor $f\simeq 1$. For
+Ca$_2$CrWO$_6$ and Ba$_2$CrWO$_6$ structural changes result in a strong
+reduction of $T_C$. Our study strongly suggests that for the double perovskites
+in general an optimum $T_C$ is achieved only for $f \simeq 1$, that is, for an
+undistorted perovskite structure. Electron doping in Sr$_2$CrWO$_6$ by a
+partial substitution of Sr$^{2+}$ by La$^{3+}$ was found to reduce both $T_C$
+and the saturation magnetization $M_s$. The reduction of $M_s$ could be
+attributed both to band structure effects and the Cr/W antisites induced by
+doping. Band structure calculations for Sr$_2$CrWO$_6$ predict an energy gap in
+the spin-up band, but a finite density of states for the spin-down band. The
+predictions of the band structure calculation are consistent with our optical
+measurements. Our experimental results support the presence of a kinetic energy
+driven mechanism in $A_2$CrWO$_6$, where ferromagnetism is stabilized by a
+hybridization of states of the nonmagnetic W-site positioned in between the
+high spin Cr-sites.",0306357v1
+2005-06-09,Magnetoresistance Anisotropy of Polycrystalline Cobalt Films: Geometrical-Size- and Domain-Effects,"The magnetoresistance (MR) of 10 nm to 200 nm thin polycrystalline Co-films,
+deposited on glass and insulating Si(100), is studied in fields up to 120 kOe,
+aligned along the three principal directions with respect to the current:
+longitudinal, transverse (in-plane), and polar (out-of-plane). At technical
+saturation, the anisotropic MR (AMR) in polar fields turns out to be up to
+twice as large as in transverse fields, which resembles the yet unexplained
+geometrical size-effect (GSE), previously reported for Ni- and Permalloy films.
+Upon increasing temperature, the polar and transverse AMR's are reduced by
+phonon-mediated sd-scattering, but their ratio, i.e. the GSE remains unchanged.
+Basing on Potters's theory [Phys.Rev.B 10, 4626(1974)], we associate the GSE
+with an anisotropic effect of the spin-orbit interaction on the sd-scattering
+of the minority spins due to a film texture. Below magnetic saturation, the
+magnitudes and signs of all three MR's depend significantly on the domain
+structures depicted by magnetic force microscopy. Based on hysteresis loops and
+taking into account the GSE within an effective medium approach, the three MR's
+are explained by the different magnetization processes in the domain states.
+These reveal the importance of in-plane uniaxial anisotropy and out-of-plane
+texture for the thinnest and thickest films, respectively.",0506232v1
+2007-03-02,Nuclear-induced time evolution of entanglement of two-electron spins in anisotropically coupled quantum dot,"We study the time evolution of entanglement of two spins in anisotropically
+coupled quantum dot interacting with the unpolarized nuclear spins environment.
+We assume that the exchange coupling strength in the z-direction $J_z$ is
+different from the lateral one $J_l$. We observe that the entanglement decays
+as a result of the coupling to the nuclear environment and reaches a saturation
+value, which depends on the value of the exchange interaction difference $J=\|
+J_l-J_z\|$ between the two spins and the strength of the applied external
+magnetic field. We find that the entanglement exhibits a critical behavior
+controlled by the competition between the exchange interaction $J$ and the
+external magnetic field. The entanglement shows a quasi-symmetric behavior
+above and below a critical value of the exchange interaction. It becomes more
+symmetric as the external magnetic field increases. The entanglement reaches a
+large saturation value, close to unity, when the exchange interaction is far
+above or below its critical value and a small one as it closely approaches the
+critical value. Furthermore, we find that the decay rate profile of
+entanglement is linear when the exchange interaction is much higher or lower
+than the critical value but converts to a power law and finally to a Gaussian
+as the critical value is approached from both directions. The dynamics of
+entanglement is found to be independent of the exchange interaction for
+isotropically coupled quantum dot.",0703054v3
+2011-03-07,Effect of Ambipolar Diffusion on the Non-linear Evolution of Magnetorotational Instability in Weakly Ionized Disks,"We study the role of ambipolar diffusion (AD) on the non-linear evolution of
+the MRI in protoplanetary disks using the strong coupling limit, which applies
+when the electron recombination time is much shorter than the orbital time. The
+effect of AD in this limit is characterized by the dimensionless number Am, the
+frequency of which neutral particles collide with ions normalized to the
+orbital frequency. We perform three-dimensional unstratified shearing-box
+simulations of the MRI over a wide range of Am as well as different magnetic
+field strengths and geometries. The saturation level of the MRI turbulence
+depends on the magnetic geometry and increases with the net magnetic flux.
+There is an upper limit to the net flux for sustained turbulence, corresponding
+to the requirement that the most unstable vertical wavelength be less than the
+disk scale height. Correspondingly, at a given Am, there exists a maximum value
+of the turbulent stress alpha_max. For Am<1, the largest stress is associated
+with a field geometry that has both net vertical and toroidal flux. In this
+case, we confirm the results of linear analyses that show the fastest growing
+mode has a non-zero radial wave number with growth rate exceeding the pure
+vertical field case. We find there is a very tight correlation between the
+turbulent stress (alpha) and the plasma beta=P_gas/P_mag~1/(2alpha) at the
+saturated state of the MRI turbulence regardless of field geometry, and
+alpha_max rapidly decreases with decreasing Am. In particular, we quote
+alpha_max~0.007 for Am=1 and alpha_max~0.0006 for Am=0.1.",1103.1380v1
+2014-01-27,Direct determination of exchange parameters in Cs2CuBr4 and Cs2CuCl4: high-field ESR studies,"Spin-1/2 Heisenberg antiferromagnets Cs$_2$CuCl$_4$ and Cs$_2$CuBr$_4$ with
+distorted triangular-lattice structures are studied by means of electron spin
+resonance spectroscopy in magnetic fields up to the saturation field and above.
+In the magnetically saturated phase, quantum fluctuations are fully suppressed,
+and the spin dynamics is defined by ordinary magnons. This allows us to
+accurately describe the magnetic excitation spectra in both materials and,
+using the harmonic spin-wave theory, to determine their exchange parameters.
+The viability of the proposed method was proven by applying it to
+Cs$_2$CuCl$_4$, yielding $J/k_B=4.7(2)$ K, $J'/k_B=1.42(7)$ K [$J'/J\simeq
+0.30$] and revealing good agreement with inelastic neutron-scattering results.
+For the isostructural Cs$_2$CuBr$_4$, we obtain $J/k_B=14.9(7)$ K,
+$J'/k_B=6.1(3)$ K, [$J'/J\simeq 0.41$], providing exact and conclusive
+information on the exchange couplings in this frustrated spin system.",1401.6793v2
+2014-10-01,Spin gapless semiconducting behavior in equiatomic quaternary CoFeMnSi Heusler alloy,"Spin gapless semiconductors (SGS) form a new class of magnetic
+semiconductors, which has a band gap for one spin sub band and zero band gap
+for the other, and thus are useful for tunable spin transport based
+applications. In this paper, we report the first experimental evidence for spin
+gapless semiconducting behavior in CoFeMnSi Heusler alloy. Such a behavior is
+also confirmed by first principles band structure calculations. The most stable
+configuration obtained by the theoretical calculation is verified by
+experiment. The alloy is found to crystallize in the cubic Heusler structure
+(LiMgPdSn type) with some amount of disorder and has a saturation magnetization
+of 3.7 Bohr's magneton/f.u.. and Curie temperature of 620 K. The saturation
+magnetization is found to follow the Slater-Pauling behavior, one of the
+prerequisites for SGS. Nearly temperature-independent carrier concentration and
+electrical conductivity is observed from 5 to 300 K. An anomalous Hall
+coefficient of 162 S/cm is obtained at 5 K. Point contact Andreev reflection
+data has yielded the current spin polarization value of 0.64, which is found to
+be robust against the structural disorder. All these properties are quite
+promising for the spintronic applications such as spin injection and can bridge
+a gap between the contrasting behavior of half-metallic ferromagnets and
+semiconductors.",1410.0177v1
+2015-07-19,Unsaturated both large positive and negative magnetoresistance in Weyl Semimetal TaP,"After growing successfully TaP single crystal, we measured its longitudinal
+resistivity (rhoxx) and Hall resistivity (rhoyx) at magnetic fields up to 9T in
+the temperature range of 2-300K. It was found that at 2K its magnetoresistivity
+(MR) reaches to 328000 percent, at 300K to 176 percent at 8T, and both do not
+appear saturation. We confirmed that TaP is indeed a low carrier concentration,
+hole-electron compensated semimetal, with a high mobility of hole muh=371000
+cm2V-1s-1, and found that a magnetic-field-induced metal-insulator transition
+occurs at room temperature. Remarkably, as a magnetic field (H) is applied in
+parallel to the electric field (E), the negative MR due to chiral anomaly is
+observed, and reaches to -3000 percent at 9T without any signature of
+saturation, too, which distinguishes with other Weyl semimetals (WSMs). The
+analysis on the Shubnikov-de Haas (SdH) oscillations superimposing on the MR
+reveals that a nontrivial Berry phase with strong offset of 0.3958 realizes in
+TaP, which is the characteristic feature of the charge carriers enclosing a
+Weyl nodes. These results indicate that TaP is a promising candidate not only
+for revealing fundamental physics of the WSM state but also for some novel
+applications.",1507.05246v1
+2016-08-29,Sub-micrometer yttrium iron garnet LPE films with low ferromagnetic resonance losses,"Using liquid phase epitaxy (LPE) technique (111) yttrium iron garnet (YIG)
+films with thicknesses of ~100 nm and surface roughnesses as low as 0.3 nm have
+been grown as a basic material for spin-wave propagation experiments in
+microstructured waveguides. The continuously strained films exhibit nearly
+perfect crystallinity without significant mosaicity and with effective lattice
+misfits of delta a(perpendicular)/a(substrate) ~10-4 and below. The
+film/substrate interface is extremely sharp without broad interdiffusion layer
+formation. All LPE films exhibit a nearly bulk-like saturation magnetization of
+(1800+-20) Gs and an `easy cone' anisotropy type with extremely small in-plane
+coercive fields <0.2 Oe. There is a rather weak in-plane magnetic anisotropy
+with a pronounced six-fold symmetry observed for saturation field <1.5 Oe. No
+significant out-of-plane anisotropy is observed, but a weak dependence of the
+effective magnetization on the lattice misfit is detected. The narrowest
+ferromagnetic resonance linewidth is determined to be 1.4 Oe @ 6.5 GHz which is
+the lowest value reported so far for YIG films of 100 nm thicknesses and below.
+The Gilbert damping coefficient for investigated LPE films is estimated to be
+close to 1 x 10-4.",1608.08043v1
+2017-08-24,Stochastic Electron Acceleration by the Whistler Instability in a Growing Magnetic Field,"We use 2D particle-in-cell (PIC) simulations to study the effect of the
+saturated whistler instability on the viscous heating and nonthermal
+acceleration of electrons in a shearing, collisionless plasma with a growing
+magnetic field, \textbf{B}. In this setup, an electron pressure anisotropy with
+$p_{\perp,e} > p_{||,e}$ naturally arises due to the adiabatic invariance of
+the electron magnetic moment ($p_{||,e}$ and $p_{\perp,e}$ are the pressures
+parallel and perpendicular to \textbf{B}). If the anisotropy is large enough,
+the whistler instability arises, efficiently scattering the electrons and
+limiting $\Delta p_e$ ($\equiv p_{\perp,e}-p_{||,e}$). In this context, $\Delta
+p_e$ taps into the plasma velocity shear, producing electron heating by the so
+called anisotropic viscosity. In our simulations, we permanently drive the
+growth of $|\textbf{B}|$ by externally imposing a plasma shear, allowing us to
+self-consistently capture the long-term, saturated whistler instability
+evolution. We find that besides the viscous heating, the scattering by whistler
+modes can stochastically accelerate electrons to nonthermal energies. This
+acceleration is most prominent when initially $\beta_e\sim 1$, gradually
+decreasing its efficiency for larger values of $\beta_e$ ($\equiv 8\pi
+p_e/|\textbf{B}|^2$). If initially $\beta_e \sim 1$, the final electron energy
+distribution can be approximately described by a thermal component, plus a
+power-law tail with spectral index $\sim 3.7$. In these cases, the nonthermal
+tail accounts for $\sim 5\%$ of the electrons, and for $\sim 15\%$ of their
+kinetic energy. We discuss the implications of our results for electron heating
+and acceleration in low-collisionality astrophysical environments, such as
+low-luminosity accretion flows.",1708.07254v2
+2019-03-02,"A spin dynamics study in layered van der Waals single crystal, Cr$_2$Ge$_2$Te$_6$","We study the magnetisation dynamics of a bulk single crystal
+Cr$_2$Ge$_2$Te$_6$ (CGT), by means of broadband ferromagnetic resonance (FMR),
+for temperatures from 60 K down to 2 K. We determine the Kittel relations of
+the fundamental FMR mode as a function of frequency and static magnetic field
+for the magnetocrystalline easy - and hard - axis. The uniaxial
+magnetocrystalline anisotropy constant is extracted and compared with the
+saturation magnetisation, when normalised with their low temperature values.
+The ratios show a clear temperature dependence when plotted in the logarithmic
+scale, which departs from the predicted Callen-Callen power law fit of a
+straight line, where the scaling exponent \textit{n}, $K_{u}(T) \propto
+[M_s(T)/M_s(2$ K$)]^n$, contradicts the expected value of 3 for uniaxial
+anisotropy. Additionally, the spectroscopic g-factor for both the magnetic easy
+- and hard - axis exhibits a temperature dependence, with an inversion between
+20 K and 30 K, suggesting an influence by orbital angular momentum. Finally, we
+qualitatively discuss the observation of multi-domain resonance phenomena in
+the FMR spectras, at magnetic fields below the saturation magnetisation.",1903.00584v2
+2021-03-26,Magnetization Reversal Signatures of Hybrid and Pure Néel Skyrmions in Thin Film Multilayers,"We report a study of the magnetization reversals and skyrmion configurations
+in two systems - Pt/Co/MgO and Ir/Fe/Co/Pt multilayers, where magnetic
+skyrmions are stabilized by a combination of dipolar and Dzyaloshinskii-Moriya
+interactions (DMI). First Order Reversal Curve (FORC) diagrams of low-DMI
+Pt/Co/MgO and high-DMI Ir/Fe/Co/Pt exhibit stark differences, which are
+identified by micromagnetic simulations to be indicative of hybrid and pure
+N\'eel skyrmions, respectively. Tracking the evolution of FORC features in
+multilayers with dipolar interactions and DMI, we find that the negative FORC
+valley, typically accompanying the positive FORC peak near saturation,
+disappears under both reduced dipolar interactions and enhanced DMI. As these
+conditions favor the formation of pure Neel skyrmions, we propose that the
+resultant FORC feature - a single positive FORC peak near saturation - can act
+as a fingerprint for pure N\'eel skyrmions in multilayers. Our study thus
+expands on the utility of FORC analysis as a tool for characterizing spin
+topology in multilayer thin films.",2103.14527v1
+2021-11-08,Magnetic properties of a capped kagome molecule with 60 quantum spins,"We compute ground-state properties of the isotropic, antiferromagnetic
+Heisenberg model on the sodalite cage geometry. This is a 60-spin spherical
+molecule with 24 vertex-sharing tetrahedra which can be regarded as a molecular
+analogue of a capped kagome lattice and which has been synthesized with
+high-spin rare-earth atoms. Here, we focus on the $S=1/2$ case where quantum
+effects are strongest. We employ the SU(2)-symmetric density-matrix
+renormalization group (DMRG).
+  We find a threefold degenerate ground state that breaks the spatial symmetry
+and that splits up the molecule into three large parts which are almost
+decoupled from each other. This stands in sharp contrast to the behaviour of
+most known spherical molecules. On a methodological level, the disconnection
+leads to ""glassy dynamics"" within the DMRG that cannot be targeted via standard
+techniques.
+  In the presence of finite magnetic fields, we find broad magnetization
+plateaus at 4/5, 3/5, and 1/5 of the saturation, which one can understand in
+terms of localized magnons, singlets, and doublets which are again nearly
+decoupled from each other. At the saturation field, the zero-point entropy is
+$S=\ln(182)\approx 5.2$ in units of the Boltzmann constant.",2111.04549v4
+2022-01-07,Nonlinear evolution of the magnetorotational instability in eccentric disks,"The magnetorotational instability (MRI) has been extensively studied in
+circular magnetized disks, and its ability to drive accretion has been
+demonstrated in a multitude of scenarios. There are reasons to expect eccentric
+magnetized disks to also exist, but the behavior of the MRI in these disks
+remains largely uncharted territory. Here we present the first simulations that
+follow the nonlinear development of the MRI in eccentric disks. We find that
+the MRI in eccentric disks resembles circular disks in two ways, in the overall
+level of saturation and in the dependence of the detailed saturated state on
+magnetic topology. However, in contrast with circular disks, the Maxwell stress
+in eccentric disks can be negative in some disk sectors, even though the
+integrated stress is always positive. The angular momentum flux raises the
+eccentricity of the inner parts of the disk and diminishes the same of the
+outer parts. Because material accreting onto a black hole from an eccentric
+orbit possesses more energy than material tracing the innermost stable circular
+orbit, the radiative efficiency of eccentric disks may be significantly lower
+than circular disks. This may resolve the ""inverse energy problem"" seen in many
+tidal disruption events.",2201.03728v2
+2022-07-06,Control of magnetoelastic coupling in Ni/Fe multilayers using He$^+$ ion irradiation,"This study reports the effects of post-growth He$^+$ irradiation on the
+magneto-elastic properties of a $Ni$ /$Fe$ multi-layered stack. The progressive
+intermixing caused by He$^+$ irradiation at the interfaces of the multilayer
+allows us to tune the saturation magnetostriction value with increasing He$^+$
+fluences, and even to induce a reversal of the sign of the magnetostrictive
+effect. Additionally, the critical fluence at which the absolute value of the
+magnetostriction is dramatically reduced is identified. Therefore insensitivity
+to strain of the magnetic stack is nearly reached, as required for many
+applications. All the above mentioned effects are attributed to the combination
+of the negative saturation magnetostriction of sputtered Ni, Fe layers and the
+positive magnetostriction of the Ni$_{x}$Fe$_{1-x}$ alloy at the intermixed
+interfaces, whose contribution is gradually increased with irradiation.
+Importantly the irradiation does not alter the layers polycrystalline
+structure, confirming that post-growth He$^+$ ion irradiation is an excellent
+tool to tune the magneto-elastic properties of magnetic samples. A new class of
+spintronic devices can be envisioned with a material treatment able to
+arbitrarily change the magnetostriction with ion-induced ""magnetic patterning"".",2207.02493v1
+2022-12-06,Steady states of the Parker instability,"We study the linear properties, nonlinear saturation and a steady, strongly
+nonlinear state of the Parker instability in galaxies. We consider magnetic
+buoyancy and its consequences with and without cosmic rays. Cosmic rays are
+described using the fluid approximation with anisotropic, non-Fickian
+diffusion. To avoid unphysical constraints on the instability (such as boundary
+conditions often used to specify an unstable background state), nonideal MHD
+equations are solved for deviations from a background state representing an
+unstable magnetohydrostatic equilibrium. We consider isothermal gas and neglect
+rotation. The linear evolution of the instability is in broad agreement with
+earlier analytical and numerical models; but we show that most of the
+simplifying assumptions of the earlier work do not hold, such that they provide
+only a qualitative rather than quantitative picture. In its nonlinear stage the
+instability has significantly altered the background state from its initial
+state. Vertical distributions of both magnetic field and cosmic rays are much
+wider, the gas layer is thinner, and the energy densities of both magnetic
+field and cosmic rays are much reduced. The spatial structure of the nonlinear
+state differs from that of any linear modes. A transient gas outflow is driven
+by the weakly nonlinear instability as it approaches saturation.",2212.03215v1
+2023-05-15,Influence of amorphous phase on coercivity in SmCo5-Cu nanocomposites,"Severe plastic deformation of powder blends consisting of SmCo5-Cu results in
+magnetically hardened nanocomposite bulk materials. The microstructure is
+continuously refined with increasing torsional deformation, yet, coercivity
+saturates at a certain level of strain. Transmission electron microscopy (TEM)
+investigation of the microstructure reveals a partial amorphization of the
+SmCo5 phase due to high-pressure torsion by 20 applied rotations. In this
+amorphous matrix nanocrystals are embedded. The effect of these experimentally
+observed microstructural features on the magnetic properties are investigated
+by micromagnetic simulations, which show that an increasing volume fraction of
+nanocrystals is beneficial for higher coercivities. For a fixed volume fraction
+of nanocrystals the simulations reveal an increasing coercivity with decreasing
+the size of the nanocrystals due to increasing number of interfaces acting as
+pinning sites. Furthermore, our micromagnetic simulations disclose the
+mechanisms of the saturation and decline of magnetic hardening due to the
+strain induced by high-pressure torsion. The calculated coercivity fits very
+well to the experimentally observed coercivity of Hc=1.34 T. The knowledge can
+also be used to develop and provide optimization strategies from the
+microstructure perspective.",2305.08948v1
+2023-09-27,Helical and nonhelical large-scale dynamos in thin accretion discs,"The dynamics of accreting and outgoing flows around compact objects depends
+crucially on the strengths and configurations of the magnetic fields therein,
+especially of the large-scale fields that remain coherent beyond turbulence
+scales. Possible origins of these large-scale magnetic fields include flux
+advection and disc dynamo actions. However, most numerical simulations have to
+adopt an initially strong large-scale field rather than allow them to be
+self-consistently advected or amplified, due to limited computational
+resources. The situation can be partially cured by using sub-grid models where
+dynamo actions only reachable at high resolutions are mimicked by artificial
+terms in low-resolution simulations. In this work, we couple thin-disc models
+with local shearing-box simulation results to facilitate more realistic
+sub-grid dynamo implementations. For helical dynamos, detailed spatial profiles
+of dynamo drivers inferred from local simulations are used, and the nonlinear
+quenching and saturation is constrained by magnetic helicity evolution. In the
+inner disc region, saturated fields have dipole configurations and the plasma
+$\beta$ reaches $\simeq 0.1$ to $100$, with correlation lengths $\simeq h$ in
+the vertical direction and $\simeq 10h$ in the radial direction, where $h$ is
+the disc scale height. The dynamo cycle period is $\simeq 40$ orbital time
+scale, compatible with previous global simulations. Additionally, we explore
+two dynamo mechanisms which do not require a net kinetic helicity and have only
+been studied in shearing-box setups. We show that such dynamos are possible in
+thin accretion discs, but produce field configurations that are incompatible
+with previous results. We discuss implications for future general-relativistic
+magnetohydrodynamics simulations.",2309.15565v2
+1996-07-28,The Protogalactic Origin for Cosmic Magnetic Fields,"It is demonstrated that strong magnetic fields are produced from a zero
+initial magnetic field during the pregalactic era, when galaxies are first
+forming. Their development proceeds in three phases. In the first phase, weak
+magnetic fields are created by the Biermann battery mechanism, acting in
+shocked parts of the intergalactic medium where caustics form and intersect. In
+the second phase, these weak magnetic fields are amplified to strong magnetic
+fields by the Kolmogoroff turbulence endemic to gravitational structure
+formation of galaxies. During this second phase, the magnetic fields reach
+saturation with the turbulent power, but they are coherent only on the scale of
+the smallest eddy. In the third phase, the magnetic field strength increases to
+equipartition with the turbulent energy, and the coherence length of the
+magnetic fields increases to the scale of the largest turbulent eddy,
+comparable to the scale of the entire galaxy. The resulting magnetic field
+represents a galactic magnetic field of primordial origin. No further dynamo
+action is necessary, after the galaxy forms, to explain the origin of magnetic
+fields. However, the magnetic field may be altered by dynamo action once the
+galaxy and the galactic disk have formed. It is first shown by direct numerical
+simulations, that thermoelectric currentsassociated with the Biermann battery,
+build the field up from zero to $10^{-21}$ G in the regions about to collapse
+into galaxies, by $z\sim3$. For weak fields, in the absence of dissipation, the
+cyclotron frequency ${\bf \omega_{cyc}}=e{\bf B } /m_H c $ and $ {\bf
+\omega}/(1+ \chi )$, where ${\bf \omega = \nabla \times v }$ is the vorticity
+and $\chi$ is the degree of ionization, satisfy the same equations, and initial
+conditions ${\bf \omega_{cyc}=\omega}=0$, so that, ${\bf \omega_{cyc}}({\bf",9607141v1
+2010-11-26,Galactic ménage à trois: Simulating magnetic fields in colliding galaxies,"We present high resolution simulations of a multiple merger of three disk
+galaxies including the evolution of magnetic fields performed with the
+N-body/SPH code Gadget. For the first time, we embed the galaxies in a
+magnetized, low-density medium, thus modeling an ambient IGM. The simulations
+include radiative cooling and a model for star formation and supernova
+feedback. The progenitor disks have initial magnetic seed fields in the range
+of 10e-9 to 10e-6 G and the IGM has initial fields of 10e-12 to 10e-9 G. The
+simulations are compared to a run excluding magnetic fields. We show that the
+propagation of interaction-driven shocks depends significantly on the initial
+magnetic field strength. The shocks propagate faster in simulations with
+stronger initial field, suggesting that the shocks are supported by magnetic
+pressure. The Mach numbers of the shocks range from approximately M=1.5 for the
+non-magnetized case up to M=6 for the highest initial magnetization, resulting
+in higher temperatures of the shock heated IGM gas. The magnetic field in the
+system saturates rapidly after the mergers at ~ 10e-6 G within the galaxies and
+~ 10e-8 G in the IGM independent of the initial value. These field strengths
+agree with observed values and correspond to the equipartition value of the
+magnetic pressure with the turbulent pressure in the system. We also present
+synthetic radio and polarization maps for different phases of the evolution
+showing that shocks driven by the interaction produce a high amount of
+polarized emission. These idealized simulations indicate that magnetic fields
+play an important role for the hydrodynamics of the IGM during galactic
+interactions. We also show that even weak seed fields are efficiently
+strengthened during multiple galactic mergers. This interaction driven
+amplification might have been a key process for the magnetization of the
+Universe.",1011.5735v2
+2018-03-16,Generation of Electron Whistler Waves at the Mirror Mode Magnetic Holes: MMS Observations and PIC Simulation,"The Magnetospheric Multiscale (MMS) mission has observed electron whistler
+waves at the center and at the edges of magnetic holes in the dayside
+magnetosheath. The magnetic holes are nonlinear mirror structures since their
+magnitude is anti-correlated with particle density. In this article, we examine
+the growth mechanisms of these whistler waves and their interaction with the
+host magnetic hole. In the observations, as magnetic holes develop and get
+deeper, an electron population gets trapped and develops a temperature
+anisotropy favorable for whistler waves to be generated. In addition, the
+decrease in magnetic field magnitude and the increase in density reduces the
+electron resonance energy, which promotes the electron cyclotron resonance. To
+investigate this process, we used an expanding box particle-in-cell simulations
+to produce the mirror instability, which then evolves into magnetic holes. The
+simulation shows that whistler waves can be generated at the center and edges
+of magnetic holes, which reproduces the primary features of the MMS
+observations. The simulation shows that the electron temperature anisotropy
+develops in the center of the magnetic hole once the mirror instability reaches
+its nonlinear stage of evolution. The plasma is then unstable to whistler waves
+at the minimum of the magnetic field structures. In the saturation regime of
+mirror instability, when magnetic holes are developed, the electron temperature
+anisotropy appears at the edges of the holes and electron distributions become
+more isotropic at the magnetic field minimum. At the edges, the expansion of
+magnetic holes decelerates the electrons which leads to temperature
+anisotropies.",1803.06399v1
+2023-03-21,Robust intralayer antiferromagnetism and tricriticality in a van der Waals compound: VBr3 case,"We studied magnetic states and phase transitions in the van der Waals
+antiferromagnet VBr3 by specific heat and magnetization measurements of single
+crystals in high magnetic fields and by ab initio density functional theory
+calculations focused on exchange interactions. The magnetization behavior
+resembles Ising antiferromagnets with magnetic moments kept in the out-of-plane
+direction by strong uniaxial magnetocrystalline anisotropy. The out-of-plane
+magnetic field induces a spin-flip metamagnetic transition, which is of
+first-order type at low temperatures while at higher temperatures the
+transition becomes continuous. The first-order and continuous transition
+segments in the field-temperature phase diagram meet at a tricritical point at
+= 12 K. The magnetization response to the in-plane field manifests a continuous
+spin-flop transition, which at 2 K terminates at a field mu0Hc = 27 T that can
+serve as an estimate of the anisotropy field in VBr3. The magnetization curves
+above the metamagnetic transition saturate at the same value of magnetic moment
+musat = 1.2 muB/f.u., which is much smaller than the spin-only (S = 1) moment
+of the V3+ ion. The reduced moment can be explained by the existence of a
+significant orbital magnetic moment antiparallel to the spin. The orbital
+moment is a key ingredient of a mechanism responsible for the observed large
+anisotropy. The exact energy evaluation of possible magnetic orders
+unambiguously shows that the magnetic ground state of VBr3 is the intralayer
+zigzag antiferromagnetic order that renders the antiferromagnetic ground state
+significantly more stable against the spin-flip transition than the other
+options. The calculations also predict that a minimal distortion of the Br ion
+sublattice causes a radical change of the orbital occupation in the ground
+state, connected with the formation of the orbital moment and the stability of
+magnetic order.",2303.11794v2
+2011-08-30,Comparison Between Turbulent Helical Dynamo Simulations and a Nonlinear Three-Scale Theory,"Progress toward understanding principles of nonlinear growth and saturation
+of large scale magnetic fields has emerged from comparison of theoretical
+models that incorporate the evolution of magnetic helicity with numerical
+simulations for problems that are more idealized than expected in astrophysical
+circumstances, but still fully non-linear. We carry out a new comparison of
+this sort for the magnetic field growth from forced isotropic helical
+turbulence in a periodic box. Previous comparisons be- tween analytic theory
+and simulations of this problem have shown that a two-scale model compares well
+with the simulations in agreeing that the driver of large scale field growth is
+the difference between kinetic and current helicities associated with the small
+scale field, and that the backreaction that slows the growth of the large scale
+field as the small scale current helicity grows. However, the two-scale model
+artificially re- stricts the small scale current helicity to reside at the same
+scale as the driving kinetic helicity. In addition, previous comparisons have
+focused on the late time saturation regime, and less on the early-time growth
+regime. Here we address these issues by comparing a three scale model to new
+simulations for both early and late time growth regimes. We find that the
+minimalist extension to three scales provides a better model for the field
+evolution than the two-scale model because the simulations show that the small
+scale current helicity does not reside at the same scale as that of the driving
+kinetic helicity. The simulations also show that the peak of the small scale
+current helicity migrates toward lower wave numbers as the growth evolves from
+the fast to saturated growth regimes.",1108.6079v2
+2012-01-03,The Effects of Anisotropic Viscosity on Turbulence and Heat Transport in the Intracluster Medium,"In the intracluster medium (ICM) of galaxy clusters, heat and momentum are
+transported almost entirely along (but not across) magnetic field lines. We
+perform the first fully self-consistent Braginskii-MHD simulations of galaxy
+clusters including both of these effects. Specifically, we perform local and
+global simulations of the magnetothermal instability (MTI) and the
+heat-flux-driven buoyancy instability (HBI) and assess the effects of viscosity
+on their saturation and astrophysical implications. We find that viscosity has
+only a modest effect on the saturation of the MTI. As in previous calculations,
+we find that the MTI can generate nearly sonic turbulent velocities in the
+outer parts of galaxy clusters, although viscosity somewhat suppresses the
+magnetic field amplification. At smaller radii in cool-core clusters, viscosity
+can decrease the linear growth rates of the HBI. However, it has less of an
+effect on the HBI's nonlinear saturation, in part because three-dimensional
+interchange motions (magnetic flux tubes slipping past each other) are not
+damped by anisotropic viscosity. In global simulations of cool core clusters,
+we show that the HBI robustly inhibits radial thermal conduction and thus
+precipitates a cooling catastrophe. The effects of viscosity are, however, more
+important for higher entropy clusters. We argue that viscosity can contribute
+to the global transition of cluster cores from cool-core to non cool-core
+states: additional sources of intracluster turbulence, such as can be produced
+by AGN feedback or galactic wakes, suppress the HBI, heating the cluster core
+by thermal conduction; this makes the ICM more viscous, which slows the growth
+of the HBI, allowing further conductive heating of the cluster core and a
+transition to a non cool-core state.",1201.0754v1
+2012-12-30,Saturation of Stellar Winds from Young Suns,"We investigate mass losses via stellar winds from sun-like main sequence
+stars with a wide range of activity levels. We perform forward-type
+magnetohydrodynamical numerical experiments for Alfven wave-driven stellar
+winds with a wide range of the input Poynting flux from the photosphere.
+Increasing the magnetic field strength and the turbulent velocity at the
+stellar photosphere from the current solar level, the mass loss rate rapidly
+increases at first owing to the suppression of the reflection of the Alfven
+waves. The surface materials are lifted up by the magnetic pressure associated
+with the Alfven waves, and the cool dense chromosphere is intermittently
+extended to 10 -- 20 % of the stellar radius. The dense atmospheres enhance the
+radiative losses and eventually most of the input Poynting energy from the
+stellar surface escapes by the radiation. As a result, there is no more
+sufficient energy remained for the kinetic energy of the wind; the stellar wind
+saturates in very active stars, as observed in Wood et al. The saturation level
+is positively correlated with B_{r,0}f_0, where B_{r,0} and f_0 are the
+magnetic field strength and the filling factor of open flux tubes at the
+photosphere. If B_{r,0}f_0 is relatively large >~ 5 G, the mass loss rate could
+be as high as 1000 times. If such a strong mass loss lasts for ~ 1 billion
+years, the stellar mass itself is affected, which could be a solution to the
+faint young sun paradox. We derive a Reimers-type scaling relation that
+estimates the mass loss rate from the energetics consideration of our
+simulations. Finally, we derive the evolution of the mass loss rates, \dot{M}
+t^{-1.23}, of our simulations, combining with an observed time evolution of
+X-ray flux from sun-like stars, which is shallower than \dot{M}
+t^{-2.33+/-0.55} in Wood et al.(2005).",1212.6713v4
+2000-12-22,Large scale dynamos with helicity loss through boundaries,"Dynamo action is investigated in simulations of locally isotropic and
+homogeneous turbulence in a slab between open boundaries. It is found that a
+`pseudo-vacuum' boundary condition (where the field is vertical) leads to
+strong helicity fluxes which significantly reduce the amplitude of the
+resulting large scale field. On the other hand, if there is a conducting halo
+outside the dynamo-active region the large scale field amplitude can reach
+larger values, but the time scale after which this field is reached increases
+linearly with the magnetic Reynolds number. In both cases most of the helicity
+flux is found to occur on large scales. From the variety of models considered
+we conclude that open boundaries tend to lower the saturation field strength
+compared to the case with periodic boundaries. The rate at which this lower
+saturation field strength is attained is roughly independent of the strength of
+the turbulence and of the boundary conditions. For dynamos with less helicity,
+however, significant field strengths could be reached in a shorter time.",0012472v2
+2005-03-24,Surface imaging of late-type contact binaries II: Halpha 6563 A emission in AE Phoenicis and YY Eridani,"We present and discuss the Halpha (6563 A) observations of the contact (W UMa
+type) binaries AE Phoenicis and YY Eridani, obtaineded in 1989, 1990 and 1995
+with the CAT/CES telescope of the Southern European Observatory (ESO). In
+particular, we compare the intrinsic equivalent widths of both components with
+the NextGen theoretical models and the saturation limit. We find that the
+average Halpha equivalent widths are close to the saturation border and that
+the primary components have excess Halpha-emission, indicating enhanced
+chromospheric activity. This is compatible with both theoretical and
+observational suggestions that the primary is the more magnetically active
+component and is filled with (mostly unresolvable) dark spots and associated
+chromospheric plages.",0503548v1
+1998-03-05,Decoherence and the Thouless Crossover in One-Dimensional Conductors,"The temperature and magnetic-field dependences of the resistance of
+one-dimensional (1D) conductors have been studied in the vicinity of the
+Thouless crossover. We find that on the weak localization (WL) side of the
+crossover, these dependences are consistent with the theory of quantum
+corrections to the resistance, and the phase breaking is due to the
+quasi-elastic electron-electron interactions (the Nyquist noise). The
+temperature dependence of the phase coherence time does not saturate, and the
+quasiparticle states remain well defined over the whole WL temperature range.
+This fact, as well as observation of the Thouless crossover in 1D samples,
+argues against the idea of intrinsic decoherence by zero-point fluctuations of
+the electrons (Mohanty et al., Phys.Rev.Lett. 78, 3366 (1997)). We believe that
+frequently observed saturation of the phase coherence time is caused by the
+external microwave noise.",9803067v2
+1999-02-11,Dephasing in Metals by Two-Level Systems in the 2-Channel-Kondo Regime,"We point out a novel, non-universal contribution to the dephasing rate
+1/\tau_\phi \equiv \gamma_\phi of conduction electrons in metallic systems:
+scattering off non-magnetic two-level systems (TLSs) having almost degenerate
+Kondo ground states. In the regime \Delta_{ren} < T < T_K (\Delta_{ren} =
+renormalized level splitting, T_K = Kondo temperature), such TLSs exhibit
+non-Fermi-liquid physics that can cause \gamma_\phi, which generally decreases
+with decreasing T, to seemingly saturate in a limited temperature range before
+vanishing for T \to 0. This could explain the saturation of dephasing recently
+observed in gold wires [Mohanty et al. Phys. Rev. Lett. 78, 3366 (1997)].",9902176v2
+2000-06-22,High field magnetotransport in composite conductors: the effective medium approximation revisited,"The self consistent effective medium approximation (SEMA) is used to study
+three-dimensional random conducting composites under the influence of a strong
+magnetic field {\bf B}, in the case where all constituents exhibit isotropic
+response. Asymptotic analysis is used to obtain almost closed form results for
+the strong field magnetoresistance and Hall resistance in various types of two-
+and three-constituent isotropic mixtures for the entire range of compositions.
+Numerical solutions of the SEMA equations are also obtained, in some cases, and
+compared with those results. In two-constituent
+free-electron-metal/perfect-insulator mixtures, the magnetoresistance is
+asymptotically proportional to $|{\bf B}|$ at {\em all concentrations above the
+percolation threshold}. In three-constituent metal/insulator/superconductor
+mixtures a line of critical points is found, where the strong field
+magnetoresistance switches abruptly from saturating to non-saturating
+dependence on $|{\bf B}|$, at a certain value of the
+insulator-to-superconductor concentration ratio. This transition appears to be
+related to the phenomenon of anisotropic percolation.",0006351v1
+2000-06-23,Critical point for the strong field magnetoresistance of a normal conductor/perfect insulator/perfect conductor composite with a random columnar microstructure,"A recently developed self-consistent effective medium approximation, for
+composites with a columnar microstructure, is applied to such a
+three-constituent mixture of isotropic normal conductor, perfect insulator, and
+perfect conductor, where a strong magnetic field {\bf B} is present in the
+plane perpendicular to the columnar axis. When the insulating and perfectly
+conducting constituents do not percolate in that plane, the
+microstructure-induced in-plane magnetoresistance is found to saturate for
+large {\bf B}, if the volume fraction of the perfect conductor $p_S$ is greater
+than that of the perfect insulator $p_I$. By contrast, if $p_S<p_I$, that
+magnetoresistance keeps increasing as ${\bf B}^2$ without ever saturating. This
+abrupt change in the macroscopic response, which occurs when $p_S=p_I$, is a
+critical point, with the associated critical exponents and scaling behavior
+that are characteristic of such points. The physical reasons for the singular
+behavior of the macroscopic response are discussed. A new type of percolation
+process is apparently involved in this phenomenon.",0006376v1
+2001-11-23,Possible Superconductivity at 37 K in Graphite-Sulfur Composite,"Sulfur intercalated graphite composites with diamagnetic transitions at 6.7 K
+and 37 K are prepared. The magnetization hysteresis loops (MHL), Xray
+diffraction patterns, and resistance were measured. From the MHL, a slight
+superconducting like penetration process is observed at 15 K in low field
+region. The XRD shows no big difference from the mixture of graphite and sulfur
+indicating that the volume of the superconducting phase (if any) is very small.
+The temperature dependence of resistance shows a typical semiconducting
+behavior with a saturation in low temperature region. This saturation is either
+induced by the de-localization of conducting electrons or by possible
+superconductivity in this system.",0111445v1
+2001-12-21,Effect of annealing on electron dephasing in three-dimensional polycrystalline metals,"We have studied the effect of thermal annealing on electron dephasing times
+$\tau_\phi$ in three-dimensional polycrystalline metals. Measurements are
+performed on as-sputtered and annealed AuPd and Sb thick films, using
+weak-localization method. In all samples, we find that $\tau_\phi$ possesses an
+extremely weak temperature dependence as $T \to 0$. Our results show that the
+effect of annealing is non-universal, and it depends strongly on the amount of
+disorder quenched in the microstructures during deposition. The observed
+""saturation"" behavior of $\tau_\phi$ cannot be easily explained by magnetic
+scattering. We suggest that the issue of saturation can be better addressed in
+three-dimensional, rather than lower-dimensional, structures.",0112421v1
+2003-02-20,Optimal Size of a Complex Network,"We investigate the response behavior of an Ising system, driven by an
+oscillating field, on a small-world network, with particular attention to the
+effects of the system size. The responses of the magnetization to the driving
+field are probed by means of Monte Carlo dynamic simulations with the rewiring
+probability varied. It is found that at low and high temperatures the occupancy
+ratio, measuring how many spins follow the driving field, behaves monotonically
+with the system size. At intermediate temperatures, on the other hand, the
+occupancy ratio first grows and then reduces as the size is increased,
+displaying a resonance-like peak at a finite value of the system size. In all
+cases, further increase of the size eventually leads to saturation to finite
+values; the size at which saturation emerges is observed to depend on the
+temperature, similarly to the correlation length of the system.",0302400v1
+2005-06-01,Spin polarization induced tenfold magneto-resistivity of highly metallic 2D holes in a narrow GaAs quantum well,"We observe that an in-plane magnetic field ($B_{||}$) can induce an order of
+magnitude enhancement in the low temperature ($T$) resistivity ($\rho$) of
+metallic 2D holes in a narrow (10nm) GaAs quantum well. Moreover, we show the
+first observation of saturating behavior of $\rho(B_{||})$ at high $B_{||}$ in
+GaAs system, which suggests our large positive $\rho(B_{||})$ is due to the
+spin polarization effect alone. We find that this tenfold increase in
+$\rho(B_{||})$ even persists deeply into the 2D metallic state with the high
+$B_{||}$ saturating values of $\rho$ lower than 0.1$\times$h/e$^2$. The
+dramatic effect of $B_{||}$ we observe on the highly conductive 2D holes (with
+$B$=0 conductivity as high as 75e$^2$/h) sets strong constraint on models for
+the spin dependent transport in dilute metallic 2D systems.",0506031v3
+2007-01-24,Berezinskii-Kosterlitz-Thouless transition in two-dimensional lattice gas models,"We have considered two classical lattice-gas models, consisting of particles
+that carry multicomponent magnetic momenta, and associated with a
+two-dimensional square lattices; each site can host one particle at most, thus
+implicitly allowing for hard-core repulsion; the pair interaction, restricted
+to nearest neighbors, is ferromagnetic and involves only two components. The
+case of zero chemical potential has been investigated by Grand--Canonical Monte
+Carlo simulations; the fluctuating occupation numbers now give rise to
+additional fluid-like observables in comparison with the usual
+saturated--lattice situation; these were investigated and their possible
+influence on the critical behaviour was discussed. Our results show that the
+present model supports a Berezinskii-Kosterlitz-Thouless phase transition with
+a transition temperature lower than that of the saturated lattice counterpart
+due to the presence of ``vacancies''; comparisons were also made with similar
+models studied in the literature.",0701584v1
+1997-03-28,Non-threshold D-brane bound states and black holes with non-zero entropy,"We start with BPS-saturated configurations of two (orthogonally) intersecting
+M-branes and use the electro-magnetic duality or dimensional reduction along a
+boost, in order to obtain new p-brane bound states. In the first case the
+resulting configurations are interpreted as BPS-saturated non-threshold bound
+states of intersecting p-branes, and in the second case as p-branes
+intersecting at angles and their duals. As a by-product we deduce the
+enhancement of supersymmetry as the angle approaches zero. We also comment on
+the D-brane theory describing these new bound states, and a connection between
+the angle and the world-volume gauge fields of the D-brane system. We use these
+configurations to find new embeddings of the four and five dimensional black
+holes with non-zero entropy, whose entropy now also depends on the angle and
+world-volume gauge fields. The corresponding D-brane configuration sheds light
+on the microscopic entropy of such black holes.",9703204v4
+2007-05-03,Non-saturating magnetoresistance of inhomogeneous conductors: comparison of experiment and simulation,"The silver chalcogenides provide a striking example of the benefits of
+imperfection. Nanothreads of excess silver cause distortions in the current
+flow that yield a linear and non-saturating transverse magnetoresistance (MR).
+Associated with the large and positive MR is a negative longitudinal MR. The
+longitudinal MR only occurs in the three-dimensional limit and thereby permits
+the determination of a characteristic length scale set by the spatial
+inhomogeneity. We find that this fundamental inhomogeneity length can be as
+large as ten microns. Systematic measurements of the diagonal and off-diagonal
+components of the resistivity tensor in various sample geometries show clear
+evidence of the distorted current paths posited in theoretical simulations. We
+use a random resistor network model to fit the linear MR, and expand it from
+two to three dimensions to depict current distortions in the third (thickness)
+dimension. When compared directly to experiments on Ag$_{2\pm\delta}$Se and
+Ag$_{2\pm\delta}$Te, in magnetic fields up to 55 T, the model identifies
+conductivity fluctuations due to macroscopic inhomogeneities as the underlying
+physical mechanism. It also accounts reasonably quantitatively for the various
+components of the resistivity tensor observed in the experiments.",0705.0393v1
+2007-11-11,Saturated absorption spectroscopy: elimination of crossover resonances by use of a nanocell,"It is demonstrated that velocity selective optical pumping/saturation
+resonances of reduced absorption in a Rb vapor nanocell with thickness
+\textit{L=} $\lambda $, 2$\lambda $, and 3$\lambda $ (resonant wavelength
+$\lambda $ = 780 nm) allow the complete elimination of crossover (CO)
+resonances. We observe well pronounced resonances corresponding to the
+F$_{g}=3$ $\to $ F$_{e}=2,3,4$ hyperfine transitions of the $^{85}$Rb D$_{2}$
+line with linewidths close to the natural width. A small CO resonance located
+midway between F$_{g}=3$ $\to $ F$_{e}=3$ and F$_{g}=3$ $\to$ F$_{e}=4$
+transitions appears only for \textit{L} = 4$\lambda $. The D$_{2}$ line
+($\lambda $ = 852 nm) in a Cs nanocell exhibits a similar behavior. From the
+amplitude ratio of the CO and VSOP resonances it is possible to determine the
+thickness of the column of alkali vapor in the range of 1 - 1000 $\mu $m. The
+absence of CO resonances for nanocells with $L \sim \lambda $ is attractive for
+frequency reference application and for studying transitions between Zeeman
+sublevels in external magnetic fields.",0711.1684v1
+2008-08-15,A growing dynamo from a saturated Roberts flow dynamo,"Using direct simulations, weakly nonlinear theory and nonlinear mean-field
+theory, it is shown that the quenched velocity field of a saturated nonlinear
+dynamo can itself act as a kinematic dynamo. The flow is driven by a forcing
+function that would produce a Roberts flow in the absence of a magnetic field.
+This result confirms an analogous finding by F. Cattaneo & S. M. Tobias
+(arXiv:0809.1801) for the more complicated case of turbulent convection,
+suggesting that this may be a common property of nonlinear dynamos; see also
+the talk given also online at the Kavli Institute for Theoretical Physics
+(http://online.kitp.ucsb.edu/online/dynamo_c08/cattaneo). It is argued that
+this property can be used to test nonlinear mean-field dynamo theories.",0808.2141v2
+2008-10-31,Diffusion-limited exciton-exciton annihilation in single-walled carbon nanotubes: A time-dependent analysis,"To provide physical insight into the recently observed photoluminescence
+saturation behaviors in single-walled carbon nanotubes implying the existence
+of an upper limit of exciton densities, we have performed a time-dependent
+theoretical study of diffusion-limited exciton-exciton annihilation in the
+general context of reaction-diffusion processes, for which exact treatments
+exist. By including the radiative recombination decay as a Poissonian process
+in the exactly-solvable problem of one-dimensional diffusion-driven
+two-particle annihilation, we were able to correctly model the dynamics of
+excitons as a function of time with different initial densities, which in turn
+allowed us to reproduce the experimentally observed photoluminescence
+saturation behavior at high exciton densities. We also performed Monte Carlo
+simulations of the purely stochastic, Brownian diffusive motion of
+one-dimensional excitons, which validated our analytical results. Finally, we
+consider the temperature-dependence of this diffusion-limited exciton-exciton
+annihilation and point out that high excitonic densities in SWNTs could be
+achieved at low temperature in an external magnetic field.",0810.5748v1
+2010-08-19,Precise measurement of hyperfine structure in the ${2P}_{1/2}$ state of $^{7}$Li using saturated-absorption spectroscopy,"We report a precise measurement of the hyperfine interval in the ${2P}_{1/2}$
+state of $^{7}$Li. The transition from the ground state ($D_1$ line) is
+accessed using a diode laser and the technique of saturated-absorption
+spectroscopy in hot Li vapor. The interval is measured by locking an
+acousto-optic modulator to the frequency difference between the two hyperfine
+peaks. The measured interval of 92.040(6)~MHz is consistent with an earlier
+measurement reported by us using an atomic-beam spectrometer [Das and
+Natarajan, J.\ Phys.\ B {\bf 41}, 035001 (2008)]. The interval yields the
+magnetic dipole constant in the $P_{1/2}$ state as $A=46.047(3)$, which is
+discrepant from theoretical calculations by $>80$~kHz.",1008.3228v1
+2011-05-11,Linear magnetoresistance in commercial n-type silicon due to inhomogeneous doping,"Free electron theory tells us that resistivity is independent of magnetic
+field. In fact, most observations match the semiclassical prediction of a
+magnetoresistance that is quadratic at low fields before saturating. However, a
+non-saturating linear magnetoresistance has been observed in exotic
+semiconductors such as silver chalcogenides, lightly-doped InSb, N-doped InAs,
+MnAs-GaAs composites, PrFeAsO, and epitaxial graphene. Here we report the
+observation of a large linear magnetoresistance in the ohmic regime in
+commonplace commercial n-type silicon wafer. It is well-described by a
+classical model of spatially fluctuating donor densities, and may be amplified
+by altering the aspect ratio of the sample to enhance current-jetting:
+increasing the width tenfold increased the magnetoresistance at 8 T from 445 %
+to 4707 % at 35 K. This physical picture may well offer insights into the large
+magnetoresistances recently observed in n-type and p-type Si in the non-ohmic
+regime.",1105.2174v1
+2011-10-31,Resistivity saturation in a weakly interacting 2D Fermi liquid at intermediate temperatures,"We report a highly unusual temperature dependence in the magnetoresistance of
+a weakly interacting high mobility 2D electron gas (2DEG) under a parallel
+magnetic field and when the current is perpendicular to the field. While the
+linear temperature dependence below 10 K and the exponential temperature
+dependence above 40 K agree with existing theory of electron-phonon scattering,
+a field induced resistivity saturation behaviour characterized by an almost
+complete suppression of the temperature dependence is observed from
+approximately 20 to 40 K, which is in sharp contrast to the phenomenology
+observed when the current is parallel to the field. Possible origins of this
+intriguing intermediate temperature phenomenon are discussed.",1111.0011v2
+2012-08-27,Anomalous Gluon Production and Condensation in Glasma,"The collinear color electric and magnetic fields have been discussed to be
+produced immediately after high energy heavy ion collisions. We discuss
+anomalous gluon production under the background gauge fields. The gluons are
+Nielsen-Olesen unstable modes. The production rate of the modes by Schwinger
+mechanism has recently been found to be anomalously larger than the rate of
+quarks or other stable gluons. Analyzing classical evolutions of the modes with
+initial conditions given by vacuum fluctuations, we find that their production
+makes the color electric field decay very rapidly. The life time of the field
+is approximately given by the inverse of saturation momentum in the collisions.
+We also show that the mode with zero momentum form a Bose condensate and its
+gluon number density grows up to be of the order of $1/\alpha_g$. After the
+saturation of the gluon number density, the condensate melts into quark gluon
+plasma owing to nonlinear interactions in QCD.",1208.5320v2
+2012-09-29,Realization of spin gapless semiconductors: the Heusler compound Mn2CoAl,"Recent studies have reported an interesting class of semiconductor materials
+that bridge the gap between semiconductors and halfmetallic ferromagnets. These
+materials, called spin gapless semiconductors, exhibit a bandgap in one of the
+spin channels and a zero bandgap in the other and thus allow for tunable spin
+transport. Here, a theoretical and experimental study of the spin gapless
+Heusler compound Mn2CoAl is presented. It turns out that Mn2CoAl is a very
+peculiar ferrimagnetic semiconductor with a magnetic moment of 2 {\mu}B and a
+high Curie temperature of 720 K. Below 300 K, the compound exhibits nearly
+temperature-independent conductivity, very low, temperature-independent carrier
+concentration, and a vanishing Seebeck coefficient. The magnetoresistance
+changes sign with temperature. In high fields, it is positive and
+non-saturating at low temperatures, but negative and saturating at high
+temperatures. The anomalous Hall effect is comparatively low, which is
+explained by the close antisymmetry of the Berry curvature for kz of opposite
+sign.",1210.0148v1
+2012-10-02,Amplification of a surface electromagnetic wave by running over plasma surface ultrarelativistic electron bunch as a new scheme for generation of Teraherz radiation,"The amplification of a surface electromagnetic wave by means of
+ultrarelativistic monoenergetic electron bunch running over the flat plasma
+surface in absence of a magnetic field is studied theoretically. It is shown
+that when the ratio of electron bunch number density to plasma electron number
+density multiplied by a powered to 5 relativity factor is much higher than 1,
+i.e $\gamma^5 n_b/n_p>> 1$, the saturation field of the surface electromagnetic
+wave induced by trapping of bunch electrons gains the magnitude:
+$E_x=B_y\approx 0.16 \frac{\omega_p m c}{e} (\frac{2n_b}{\gamma^2 n_p})^{1/7}$
+and does not approache the surface electromagnetic wave front breakdown
+threshold in plasma. The surface electromagnetic wave saturation energy density
+in plasma can exceed the electron bunch energy density. Here, we discuss the
+possibility of generation of superpower Teraherz radiation on a basis of such
+scheme.",1210.0610v2
+2012-10-11,Optical orientation of nuclei in nitrogen alloys GaAsN at room temperature,"The intensity and the giant circular polarization of edge luminescence in a
+longitudinal magnetic field have been measured in nitrogen alloys GaAsN under
+circularly polarized pumping. It has been found that these dependences are
+shifted with respect to zero field by a value Beff. The magnitude of the
+internal field Beff increases with increase in pumping intensity and reaches
+saturation (~250 Gauss) at great densities of excitation. The saturation of the
+Beff field with growth of pumping indicates that this is a field of nuclei,
+polarized dynamically due to hyperfine interaction with optically oriented deep
+paramagnetic centers, rather than a field of exchange interaction created on
+the center by spin-polarized photo-excited conduction electrons. The short time
+of nuclear polarization by electrons (<15 mks), measured under modulation of
+circular polarization of the exciting light with high frequency, points to a
+small number of nuclei undergoing hyperfine interaction with an electron
+localized at a center.",1210.3302v1
+2012-10-12,Organic magnetoresistance near saturation: mesoscopic effects in small devices,"In organic light emitting diodes with small area the current may be dominated
+by a finite number, N of sites in which the electron-hole recombination occurs.
+As a result, averaging over the hyperfine magnetic fields, b_h, that are
+generated in these sites by the environment nuclei is incomplete. This creates
+a random (mesoscopic) current component, {\Delta}I(B), at field B having
+relative magnitude ~ N^(-1/2). To quantify the statistical properties of
+{\Delta}I(B) we calculate the correlator K(B, {\Delta}B)= <{\delta}I(B -
+{\Delta}B/2){\delta}I(B + {\Delta}B/2)> for parallel and perpendicular
+orientations of {\Delta}B. We demonstrate that mesoscopic fluctuations develop
+at fields B>>b_h, where the average magnetoresistance is near saturation. These
+fluctuations originate from the slow beating between S and T_0 states of the
+recombining e-h spin pair-partners. We identify the most relevant processes
+responsible for the current fluctuations as due to anomalously slow beatings
+that develop in sparse e-h polaron pairs at sites for which the b_h projections
+on the external field direction almost coincide.",1210.3443v2
+2013-08-05,Implications of Resonant Inelastic X-ray Scattering Data for Theoretical Models of Cuprates,"There are two commonly discussed points of view in theoretical description of
+cuprate superconductors, (i) Cuprates can be described by the modified t-J
+model. (ii) Overdoped cuprates are close to the regime of normal Fermi liquid
+(NFL). We argue that recent resonant inelastic X-ray scattering data challenge
+both points. While the modified t-J model describes well the strongly
+underdoped regime, it fails to describe high energy magnetic excitations when
+approaching optimal doping. This probably indicates failure of the Zhang-Rice
+singlet picture. In the overdoped regime the momentum-integrated spin structure
+factor S(\omega) has the same intensity and energy distribution as that in an
+undoped parent compound. This implies that the entire spin spectral sum rule is
+saturated at \omega ~ 2J, while in a NFL the spectral weight should saturate
+only at the total bandwidth which is much larger than 2J.",1308.0987v1
+2014-01-11,Resonant instability of the nonlinearly-saturated magnetorotational mode in thin Keplerian discs,"The magneto-rotational decay instability (MRDI) of thin Keplerian discs
+threaded by poloidal magnetic fields is introduced and studied. The linear
+magnetohydrodynamic problem decouples into eigenvalue problems for in-plane
+slow- and fast- Alfv'een-Coriolis (AC), and vertical magnetosonic (MS)
+eigenmodes. The magnetorotational instability (MRI) is composed of a discrete
+number of unstable slow AC eigenmodes that is determined for each radius by the
+local beta. In the vicinity of the first beta threshold a parent MRI eigenmode
+together with a stable AC eigenmode (either slow or fast) and a stable MS
+eigenmode form a resonant triad. The three-wave MRDI relies on the nonlinear
+saturation of the parent MRI mode and the exponential growth of two daughter
+linearly stable waves, slow-AC and MS modes with an effective growth rate that
+is comparable to that of the parent MRI. If, however, the role of the AC
+daughter wave is played by a stable fast mode, all three modes remain bounded.",1401.2528v1
+2014-01-17,Computation of dynamical correlation functions of the spin-1 Babujan-Takhtajan chain,"The dynamical structure factor of the Babujan-Takhtajan antiferromagnetic
+spin-1 chain is computed numerically at zero temperature and zero magnetic
+field, using the higher-spin generalization of an Algebraic Bethe Ansatz-based
+method previously used for spin-1/2 integrable chains. This method, which
+consists in the explicit construction of eigenstates and the summation of the
+Lehmann representation of the correlator, is here particularly challenging to
+implement in view of the presence of strongly deviated string solutions to the
+Bethe equations. We show that a careful treatment of these deviations makes it
+possible to obtain perfect saturation of sum rules for small system sizes, and
+extremely good saturation for large system sizes where the dynamical structure
+factor is computed by including all two-spinon and four-spinon contributions.
+The real-space spin-spin correlation, obtained by Fourier transforming our
+results, displays asymptotics fitting predictions from conformal field theory.",1401.4450v1
+2014-04-03,Phases of triangular lattice antiferromagnet near saturation,"We consider 2D Heisenberg antiferromagnets on a triangular lattice with
+spatially anisotropic interactions in a high magnetic field close to the
+saturation. We show that this system possess rich phase diagram in
+field/anisotropy plane due to competition between classical and quantum orders:
+an incommensurate non-coplanar spiral state, which is favored classically, and
+a commensurate co-planar state, which is stabilized by quantum fluctuations. We
+show that the transformation between these two states is highly non-trivial and
+involves two intermediate phases -- the phase with co-planar incommensurate
+spin order and the one with non-coplanar double-${\bf Q}$ spiral order. The
+transition between the two co-planar states is of commensurate- incommensurate
+type, not accompanied by softening of spin-wave excitations. We show that a
+different sequence of transitions holds in triangular antiferromagnets with
+exchange anisotropy, such as Ba3CoSb2O9.",1404.1046v1
+2014-08-21,Anyonic Liquids in Nearly Saturated Spin Chains,"Most Heisenberg-like spin chains flow to a universal free-fermion fixed point
+near the magnetic-field induced saturation point. Here we show that an exotic
+fixed point, characterized by two species of low-energy excitations with mutual
+anyonic statistics, may also emerge in such spin chains if the dispersion
+relation has two minima. By using bosonization, two-magnon exact calculations,
+and numerical density-matrix-renormalization-group, we demonstrate the
+existence of this anyonic-liquid fixed point in an XXZ spin chain with up to
+second neighbor interactions. We also identify a range of microscopic
+parameters, which support this phase.",1408.5151v2
+2014-12-12,Linear magnetoresistance caused by mobility fluctuations in the n-doped Cd3As2,"Cd3As2 is a candidate three-dimensional Dirac semi-metal which has
+exceedingly high mobility and non-saturating linear magnetoresistance that may
+be relevant for future practical applications. We report magnetotransport and
+tunnel diode oscillation measurements on Cd3As2, in magnetic fields up to 65 T
+and temperatures between 1.5K to 300K. We find the non-saturating linear
+magnetoresistance persist up to 65T and it is likely caused by disorder effects
+as it scales with the high mobility, rather than directly linked to Fermi
+surface changes even when approaching the quantum limit. From the observed
+quantum oscillations, we determine the bulk three-dimensional Fermi surface
+having signatures of Dirac behaviour with non-trivial Berry's phase shift, very
+light effective quasiparticle masses and clear deviations from the
+band-structure predictions. In very high fields we also detect signatures of
+large Zeeman spin-splitting (g~16).",1412.4105v1
+2016-02-09,Mechanical energy fluxes associated with saturated coronal heating in M dwarfs: comparison with predictions of a turbulent dynamo,"Empirically, the X-ray luminosity LX from M dwarfs has been found to have an
+upper limit of about 0.2% of the bolometric flux Lbol. In the limit where
+magnetic fields in M dwarfs are generated in equipartition with convective
+motions, we use stellar models to calculate the energy flux of Alfven waves FA
+as a function of depth in the sub-surface convection zone. Since Alfven waves
+have the optimal opportunity for wave modes to reach the corona, we suggest
+that FA sets an upper limit on the mechanical flux Fmech which causes coronal
+heating. This suggestion accounts quantitatively for the saturated values of
+LX/Lbol which have been reported empirically for M dwarfs.",1602.03079v1
+2017-01-10,Saturation of resistivity and Kohler's rule in Ni-doped La$_{1.85}$Sr$_{0.15}$CuO$_{4}$ cuprate,"We present the results of electrical transport measurements of
+La$_{1.85}$Sr$_{0.15}$Cu$_{1-y}$Ni$_{y}$O$_{4}$ thin single-crystal films at
+magnetic fields up to 9 T. Adding Ni impurity with strong Coulomb scattering
+potential to slightly underdoped cuprate makes the signs of resistivity
+saturation at $\rho_{sat}$ visible in the measurement temperature window up to
+350 K. Employing the parallel-resistor formalism reveals that $\rho_{sat}$ is
+consistent with classical Ioffe-Regel-Mott limit and changes with carrier
+concentration $n$ as $\rho_{sat}\propto 1/\sqrt{n}$. Thermopower measurements
+show that Ni tends to localize mobile carriers, decreasing their effective
+concentration as $n\!\cong0.15\!-\!y$. The classical unmodified Kohler's rule
+is fulfilled for magnetoresistance in the nonsuperconducting part of the phase
+diagram when applied to the ideal branch in the parallel-resistor model.",1701.02568v1
+2017-08-21,Properties of $(TiZrNbCu)_{1-x}$$Ni_{x}$ Metallic Glasses,"Recent studies (J. Alloys Compd. 695 (2017) 2661) of the electronic structure
+and properties of $(TiZrNbCu)_{1-x}$$Ni_{x}$ (x$\leq$0.25) amorphous high
+entropy alloys (a-HEA) have been extended to x=0.5 in order to compare
+behaviours of a-HEA and conventional Ni-base metallic glasses (MG). The
+amorphous state of all samples was verified by thermal analysis and X-ray
+diffraction (XRD). XRD indicated a probable change in local atomic
+arrangements, i.e. short-range-order (SRO) for x$\geq$0.35. Simultaneously,
+thermal parameters, such as the first crystallization temperature $T_{x}$ and
+the liquidus temperature showed a tendency to saturate for x$\geq$0.35 . The
+same tendency also appeared in the magnetic susceptibility $\chi_{exp}$ and the
+linear term in the low temperature specific heat {\gamma}. The Debye
+temperatures and Youngs moduli also tend to saturate for x$\geq$0.35. These
+unusual changes in SRO and all properties within the amorphous phase seem
+correlated with the change of valence electron number (VEC) on increasing x.",1708.06171v2
+2017-12-04,Particle-hole symmetry reveals failed superconductivity in the metallic phase of two-dimensional superconducting films,"Electrons confined to two dimensions display an unexpected diversity of
+behaviors as they are cooled to absolute zero. Noninteracting electrons are
+predicted to eventually ""localize"" into an insulating ground state, and it has
+long been supposed that electron correlations stabilize only one other phase:
+superconductivity. However, many two-dimensional (2D) superconducting materials
+have shown surprising evidence for metallic behavior, where the electrical
+resistivity saturates in the zero-temperature limit, the nature of this
+unexpected metallic state remains under intense scrutiny. We report electrical
+transport properties for two disordered 2D superconductors, indium oxide and
+tantalum nitride, and observe a magnetic field-tuned transition from a true
+superconductor to a metallic phase with saturated resistivity. This metallic
+phase is characterized by a vanishing Hall resistivity, suggesting that it
+retains particle-hole symmetry from the disrupted superconducting state.",1712.00947v1
+2019-01-14,BPS soliton-impurity models and supersymmetry,"We find supersymmetric extensions of the half-BPS soliton-impurity models in
+(1+1) dimensions which preserve half of the $\mathcal{N}=1$ supersymmetry. This
+is related to the fact that in the bosonic sector (i.e., the half-BPS
+soliton-impurity model), only one soliton (for example, the kink) is a BPS
+configuration which solves the pertinent Bogomolnyi equation and saturates the
+topological energy bound. On the other hand, the topological charge conjugate
+state (the antikink) is not a BPS solution. This means that it obeys the full
+Euler-Lagrange equation and does not saturate the topological energy bound. The
+supersymmetric approach also allows us to construct half-BPS soliton-impurity
+models in (2+1) dimensions. Concretely, in the case of the $CP^1$ model, its
+BPS impurity generalisation preserves one-quarter of the $\mathcal{N}=2$ SUSY,
+while for the Abelian Higgs model at critical coupling both impurity
+generalisations preserving one-quarter (the case of a new, so-called Higgs
+impurity) as well as one-half of the $\mathcal{N}=2$ SUSY (the case of the
+previously known magnetic impurity) are possible. We also discuss a possible
+relation between the BPS $CP^1$-impurity model and the Dzyaloshinskii-Moriya
+interaction energy.",1901.04501v1
+2019-05-21,Boundary-limited and glassy-like phonon thermal conduction in EtMe$_3$Sb[Pd(dmit)$_2$]$_2$,"In molecular-based quantum-spin-liquid candidate EtMe$_3$Sb[Pd(dmit)$_2$]$_2$
+with two-dimensional $S$=1/2 triangular lattice, a finite residual linear term
+in the thermal conductivity, $\kappa_0/T\equiv\kappa/T (T \rightarrow 0)$, has
+been observed and attributed to the presence of itinerant gapless excitations.
+Here we show that the data of $\kappa$ measured in several single crystals are
+divided into two groups with and without the residual linear term. In the first
+group with finite $\kappa_0/T$, the phonon thermal conductivity $\kappa_{ph}$
+is comparable to that of other organic compounds. In these crystals, the phonon
+mean free path $\ell_{ph}$ saturates at low temperatures, being limited by
+sample size. On the other hand, in the second group with zero $\kappa_0/T$,
+$\kappa_{ph}$ is one order of magnitude smaller than that in the first group,
+comparable to that of amorphous solids. In contrast to the first group,
+$\ell_{ph}$ shows a glassy-like non-saturating behavior at low temperatures.
+These results suggest that the crystals with long $\ell_{ph}$ are required to
+discuss the magnetic excitations by thermal conductivity measurements.",1905.08420v1
+2020-01-29,Extremely slow non-equilibrium monopole dynamics in classical spin ice,"We report on the non-equilibrium monopole dynamics in the classical spin ice
+Dy$_2$Ti$_2$O$_7$ detected by means of high-resolution magnetostriction
+measurements. Significant lattice changes occur at the transition from the
+kagome-ice to the saturated-ice phase, visible in the longitudinal and
+transverse magnetostriction. A hysteresis opening at temperatures below 0.6 K
+suggests a first-order transition between the kagome and saturated state.
+Extremely slow lattice relaxations, triggered by changes of the magnetic field,
+were observed. These lattice-relaxation effects result from non-equilibrium
+monopole formation or annihilation processes. The relaxation times extracted
+from our experiment are in good agreement with theoretical predictions with
+decay constants of the order of $10{^4}$ s at 0.3 K.",2001.10844v1
+2020-05-11,Pressure tuning of the anomalous Hall effect in the chiral antiferromagnet Mn3Ge,"We report on the pressure evolution of the giant anomalous Hall effect (AHE)
+in the chiral antiferromagnet Mn$_3$Ge. The AHE originating from the
+non-vanishing Berry curvature in Mn$_3$Ge can be continuously tuned by
+application of hydrostatic pressure. At room temperature, the Hall signal
+changes sign as a function of pressure and vanishes completely at $p=1.53$ GPa.
+Even though the Hall conductivity changes sign upon increasing pressure, the
+room-temperature saturation value of 23 ${\rm \Omega^{-1}cm^{-1}}$ at 2.85 GPa
+is remarkably high and comparable to the saturation value at ambient pressure
+of about 40 ${\rm \Omega^{-1}cm^{-1}}$. The change in the Hall conductivity can
+be directly linked to a gradual change of the size of the in-plane components
+of the Mn moments in the non-collinear triangular magnetic structure. Our
+findings, therefore, provide a route for tuning of the AHE in the chiral
+antiferromagnetic Mn$_3$Ge.",2005.04967v1
+2020-06-05,Effect of Oxygen Saturation on AFM-WFM-HTSC Transition Temperatures in RuSr2(Eu1.5Ce0.5)Cu2O10-δ Ceramic Samples,"The effect of annealing in high pressure oxygen atmosphere on superconducting
+transition temperatures for ceramic samples of magnetic superconductor europium
+based 1222 ruthenocuprate was studied. It was shown that the properties of the
+samples are consistent with the behavior of granular superconducting system. As
+a result of oxygen saturation the superconducting transition temperatures
+become higher. Particularly, the shift of superconducting transition
+temperature for the intergranular medium is 9.2 K and for the matter within the
+granules 6.8 K. This difference is supposed due to the mechanism of oxygen
+diffusion along the grain boundaries. In the temperature range between 135 K
+and 350 K the behavior of resistance obeyed the Mott law of variable range
+hopping for three dimensional case.",2006.03436v1
+2020-11-27,PFG NMR time-dependent diffusion coefficient analysis of confined emulsion: post drainage phase conformation,"In this work, we present a characterization of phase configuration in
+water-saturated sintered glass bead samples after oil injection, through the
+analysis of time-dependent diffusion coefficients obtained from sets of
+one-dimensional pulsed field gradient nuclear magnetic resonance (PFG NMR)
+measurements, pre and post drainage. Estimates of samples surface-to-volume
+ratio and permeability from pre drainage PFG measurements in a water-saturated
+sample were compared with analytical and reported values, respectively, and a
+fair agreement was found in both cases. Short-time analysis of diffusion
+coefficients extracted from PFG measurements was used to quantify the increase
+in surface-to-volume ratio probed by the wetting phase after drainage. Analysis
+of water and oil diffusion coefficients from post drainage PFG experiments were
+carried out using a bi-Gaussian model, and two distinct scenarios were
+considered to describe fluids conformation within pores. For the case where
+non-wetting phase was considered to exhibit a poorly connected geometry, an
+analysis assuming the formation of oi-in-water droplets within pores was
+performed, and a Gaussian distribution of droplets radii was determined.",2011.13703v1
+2021-06-30,Temperature dependent equilibration of spin orthogonal quantum Hall edge modes,"Conductance of the edge modes as well as conductance across the
+co-propagating edge modes around the \nu = 4/3, 5/3 and 2 quantum Hall states
+are measured by individually exciting the modes. Temperature dependent
+equilibration rates of the outer unity conductance edge mode are presented for
+different filling fractions. We find that the equilibration rate of the outer
+unity conductance mode at \nu = 2 is higher and more temperature sensitive
+compared to the mode at fractional filling 5/3 and 4/3. At lowest temperature,
+equilibration length of the outer unity conductance mode tends to saturate with
+lowering filling fraction \nu by increasing magnetic field B. We speculate this
+saturating nature of equilibration length is arising from an interplay of
+Coulomb correlation and spin orthogonality.",2106.15848v1
+2021-10-17,Effective two-level approximation of a multi-level system driven by coherent and incoherent fields,"The numerical simulation of multiple scattering in dense ensembles is the
+mostly adopted solution to predict their complex optical response. While the
+scalar and vectorial light mediated interactions are accurately taken into
+account, the computational complexity still limits current simulations to the
+low saturation regime and ignores the internal structure of atoms. Here, we
+propose to go beyond these restrictions, at constant computational cost, by
+describing a multi-level system (MLS) by an effective two-level system (TLS)
+that best reproduces the coherent and total scattering properties in any
+saturation regime. The correspondence of our model is evaluated for different
+experimentally realistic conditions such as the modification of the driving
+field polarization, the presence of stray magnetic fields or an incoherent
+resonant electromagnetic field background. The trust interval of the model is
+quantified for the D2-line of 87Rb atoms but it could be generalized to any
+closed transition of a multi-level quantum system.",2110.08894v1
+2022-07-19,Microtearing turbulence saturation via electron temperature flattening at low-order rational surfaces,"Microtearing instability is one of the major sources of turbulent transport
+in high-$\beta$ tokamaks. These modes lead to very localized transport at
+low-order rational magnetic field lines, and we show that flattening of the
+local electron temperature gradient at these rational surfaces plays an
+important role in setting the saturated flux level in microtearing turbulence.
+This process depends crucially on the density of rational surfaces, and thus
+the system-size, and gives rise to a worse-than-gyro-Bohm transport scaling for
+system-sizes typical of existing tokamaks and simulations.",2207.09211v4
+2024-02-09,Simulation of ion temperature gradient driven modes with 6D kinetic Vlasov code,"With the increase in computational capabilities over the last years it
+becomes possible to simulate more and more complex and accurate physical
+models. Gyrokinetic theory has been introduced in the 1960s and 1970s in the
+need of describing a plasma with more accurate models than fluid equations, but
+eliminating the complexity of the fast gyration about the magnetic field lines.
+Although results from current gyrokinetic computer simulations are in fair
+agreement with experimental results in core physics, crucial assumptions made
+in the derivation make it unreliable in regimes of higher fluctuations and
+stronger gradient, such as the tokamak edge. With our novel optimized and
+scalable semi-Lagrangian solver we are able to simulate ion-temperature
+gradient modes with the 6D kinetic model including the turbulent saturation.
+After thoroughly testing our simulation code against analytical computations
+and gyrokinetic simulations (with the gyrokinetic code GYRO), it has been
+possible to show first plasma properties that go beyond standard gyrokinetic
+simulations. This includes the explicit description of the complete
+perpendicular energy fluxes and the excitation of high frequency waves (around
+the Larmor frequency) in the nonlinear saturation phase.",2402.06605v1
+2005-01-18,Plasma instabilities and magnetic-field growth in clusters of galaxies,"We show that under very general conditions, cluster plasmas threaded by weak
+magnetic fields are subject to very fast growing plasma instabilities driven by
+the anisotropy of the plasma pressure (viscous stress) with respect to the
+local direction of the magnetic field. Such an anisotropy will naturally arise
+in any weakly magnetized plasma that has low collisionality and is subject to
+stirring. The magnetic field must be sufficiently weak for the instabilities to
+occur, viz., beta>Re^{1/2}. The instabilities are captured by the extended MHD
+model with Braginskii viscosity. However, their growth rates are proportional
+to the wavenumber down to the ion gyroscale, so MHD equations with Braginskii
+viscosity are not well posed and a fully kinetic treatment is necessary. The
+instabilities can lead to magnetic fields in clusters being amplified from seed
+strength of ~10^{-18} G to dynamically important strengths of ~10 microG on
+cosmologically trivial time scales (~10^8 yr). The fields produced during the
+amplification stage are at scales much smaller than observed. Predicting the
+saturated field scale and structure will require a kinetic theory of magnetized
+cluster turbulence.",0501362v3
+2001-11-12,Magnetic-Superconducting phase-diagram of Eu2-xCexRuSr2Cu2O10,"Eu2-xCexRuSr2Cu2O10-d (Ru-2122) is the first Cu-O based system in which
+superconductivity (SC) in the CuO2 planes and weak-ferromagnetism (W-FM) in the
+Ru sub-lattice coexists. The hole doping in the CuO2 planes, is controlled by
+appropriate variation of the Ce concentration. SC occurs for Ce contents of
+0.4-0.8, with the highest TC=35 K for Ce=0.6. The as-prepared non-SC
+EuCeRuSr2Cu2O10 (x=1) sample exhibits magnetic irreversibility below Tirr=125 K
+and orders anti-ferromagnetically (AFM) at TM =165 K. The saturation moment at
+5 K is Msat=0.89 mB /Ru close to the expected 1 mB for the low-spin state of
+Ru5+. Annealing under oxygen pressures, does not affect these parameters,
+whereas depletion of oxygen shifts both Tirr and TM up to 169 and 215 K
+respectively. Systematic magnetic studies on Eu2-xCexRuSr2Cu2O10-d show that
+TM, Tirr and Msat decrease with x, and the Ce dependent magnetic-SC phase
+diagram is presented. A simple model for the SC state is proposed. We interpret
+the magnetic behavior in the framework of our ac and dc magnetic studies, and
+argue that: (i) the system becomes AFM ordered at TM; (b) at Tirr < TM, W-FM is
+induced by the canting of the Ru moments, and (c), at lower temperatures the
+appropriate samples become SC at TC. The magnetic features are not affected by
+the SC state, and the two states coexist.",0111217v1
+2003-05-03,Magnetic properties of the $S=1/2$ distorted diamond chain at T=0,"We explore, at T=0, the magnetic properties of the $S=1/2$ antiferromagnetic
+distorted diamond chain described by the Hamiltonian ${\cal H}
+  = \sum_{j=1}^{N/3}{J_1 ({\bi S}_{3j-1} \cdot {\bi S}_{3j}
+  + {\bi S}_{3j} \cdot {\bi S}_{3j+1})
+  + J_2 {\bi S}_{3j+1} \cdot {\bi S}_{3j+2}
+  + J_3 ({\bi S}_{3j-2} \cdot {\bi S}_{3j}
+  + {\bi S}_{3j} \cdot {\bi S}_{3j+2})}
+  \allowbreak - H \sum_{l=1}^{N} S_l^z $ with $J_1, J_2, J_3\ge0$, which well
+models ${\rm A_3 Cu_3 (PO_4)_4}$ with ${\rm A = Ca, Sr}$, ${\rm Bi_4 Cu_3 V_2
+O_{14}}$ and azurite $\rm Cu_3(OH)_2(CO_3)_2$. We employ the physical
+consideration, the degenerate perturbation theory, the level spectroscopy
+analysis of the numerical diagonalization data obtained by the Lanczos method
+and also the density matrix renormalization group (DMRG) method. We investigate
+the mechanisms of the magnetization plateaux at $M=M_s/3$ and $M=(2/3)M_s$, and
+also show the precise phase diagrams on the $(J_2/J_1, J_3/J_1)$ plane
+concerning with these magnetization plateaux, where $M=\sum_{l=1}^{N} S_l^z$
+and $M_s$ is the saturation magnetization. We also calculate the magnetization
+curves and the magnetization phase diagrams by means of the DMRG method.",0305057v1
+2003-09-26,Magnetic phases and reorientation transitions in antiferromagnetically coupled multilayers,"In antiferromagnetically coupled superlattices grown on (001) faces of cubic
+substrates, e.g. based on materials combinations as Co/Cu, Fe/Si, Co/Cr, or
+Fe/Cr, the magnetic states evolve under competing influence of bilinear and
+biquadratic exchange interactions, surface-enhanced four-fold in-plane
+anisotropy, and specific finite-size effects. Using phenomenological
+(micromagnetic) theory, a comprehensive survey of the magnetic states and
+reorientation transitions has been carried out for multilayer systems with even
+number of ferromagnetic sub-layers and magnetizations in the plane. In
+two-layer systems (N=2) the phase diagrams in dependence on components of the
+applied field in the plane include ``swallow-tail'' type regions of
+(metastable) multistate co-existence and a number of continuous and
+discontinuous reorientation transitions induced by radial and transversal
+components of the applied field. In multilayers (N \ge 4) noncollinear states
+are spatially inhomogeneous with magnetization varying across the multilayer
+stack. For weak four-fold anisotropy the magnetic states under influence of an
+applied field evolve by a complex continuous reorientation into the saturated
+state. At higher anisotropy they transform into various inhomogeneous and
+asymmetric structures. The discontinuous transitions between the magnetic
+states in these two-layers and multilayers are characterized by broad ranges of
+multi-phase coexistence of the (metastable) states and give rise to specific
+transitional domain structures.",0309621v1
+2005-08-17,Magnetic properties in a partially oxidized nanocomposite of Cu-CuCl,"Magnetism of a very thin antiferromagnetic (AFM) surface CuO has been
+investigated with the partially oxidized nanocomposites of Cu-CuCl, ~ 200 nm.
+The samples are characterized by X-ray diffraction, X-ray photoelectron
+spectroscopy, X-ray-excited Auger electron spectroscopy, transmission electron
+microscope and magnetic measurements. The characterizations indicate that the
+composites have a core-shell structure. Before the oxidation, it is
+(Cu)core/(CuCl)shell, and after the oxidation,
+(Cu)core/(Cu2O+CuCl+minuteCuO)shell. The magnetic measurements have revealed
+that a ferromagnetic (FM) like open hysteresis exists at the temperature below
+the freezing point, TF. In the high field region, a paramagnetic (PM) response
+appears without showing a sign of saturation. Also, the field dependent
+magnetization (M-H) measurement is PM-like at T > TF. These interesting
+magnetic properties are evident to arise from the AFM CuO on the outer surface.
+They are attributed to the uncompensated surface spins of Cu2+ and the effect
+of surface random potential. More interestingly, the magnetic susceptibility is
+greatly enhanced in the presence of Cl- anions at T < TF, according to the
+field-cooled/zero-field-cooled (FC/ZFC) measurements. This further supports the
+point that the disorder or frustration effect of the impurity would reduce the
+AFM ordering of CuO and increase the level of uncompensated spins.",0508387v2
+2005-08-29,"Magnetic Properties of J-J-J' Quantum Heisenberg Chains with Spin S=1/2, 1, 3/2 and 2 in a Magnetic Field","By means of the density matrix renormalization group (DMRG) method, the
+magnetic properties of the J-J-J$^{\prime}$ quantum Heisenberg chains with spin
+$S=1/2$, 1, 3/2 and 2 in the ground states are investigated in the presence of
+a magnetic field. Two different cases are considered: (a) when $J$ is
+antiferromagnetic and $J^{\prime}$ is ferromagnetic (i.e. the AF-AF-F chain),
+the system is a ferrimagnet. The plateaus of the magnetization are observed. It
+is found that the width of the plateaus decreases with increasing the
+ferromagnetic coupling, and disappears when $% J^{\prime}/J$ passes over a
+critical value. The saturated field is observed to be independent of the
+ferromagnetic coupling; (b) when $J$ is ferromagnetic and $J^{\prime}$ is
+antiferromagnetic (i.e. the F-F-AF chain), the system becomes an
+antiferromagnet. The plateaus of the magnetization are also seen. The width of
+the plateaus decreases with decreasing the antiferromagnetic coupling, and
+disappears when $J^{\prime}/J $ passes over a critical value. Though the ground
+state properties are quite different, the magnetization plateaus in both cases
+tend to disappear when the ferromagnetic coupling becomes more dominant.
+Besides, no fundamental difference between the systems with spin half-integer
+and integer has been found.",0508685v1
+2006-06-15,Exact eigenstates of highly frustrated spin lattices probed in high fields,"Strongly frustrated antiferromagnets such as the magnetic molecule
+{Mo72Fe30}, the kagome, or the pyrochlore lattice exhibit a variety of
+fascinating properties like low-lying singlets, magnetization plateaus as well
+as magnetization jumps. During recent years exact many-body eigenstates could
+be constructed for several of these spin systems. These states become ground
+states in high magnetic fields, and they also lead to exotic behavior. A key
+concept to an understanding of these properties is provided by independent
+localized magnons. The energy eigenvalue of these n-magnon states scales
+linearly with the number n of independent magnons and thus with the total
+magnetic quantum number M=Ns-n. In an applied field this results in a giant
+magnetization jump which constitutes a new macroscopic quantum effect. It will
+be demonstrated that this behavior is accompanied by a massive degeneracy, an
+extensive (T=0)-entropy, and thus a large magnetocaloric effect at the
+saturation field. The connection to flat band ferromagnetism will be outlined.",0606401v2
+2007-08-11,Relationship between macroscopic physical properties and local distortions of low doping La{1-x}Ca{x}MnO3: an EXAFS study,"A temperature-dependent EXAFS investigation of La{1-x}Ca{x}MnO3 is presented
+for the concentration range that spans the ferromagnetic-insulator (FMI) to
+ferromagnetic-metal (FMM) transition region, x = 0.16-0.22. The samples are
+insulating for x = 0.16-0.2 and show a metal/insulator transition for x = 0.22.
+All samples are ferromagnetic although the saturation magnetization for the 16%
+Ca sample is only ~ 70% of the expected value at 0.4T. We find that the FMI
+samples have similar correlations between changes in the local Mn-O distortions
+and the magnetization as observed previously for the colossal magnetoresistance
+(CMR) samples (0.2 < x < 0.5) - except that the FMI samples never become fully
+magnetized. The data show that there are at least two distinct types of
+distortions. The initial distortions removed as the insulating sample becomes
+magnetized are small and provides direct evidence that roughly 50% of the Mn
+sites have a small distortion/site and are magnetized first. The large
+remaining Mn-O distortions at low T are attributed to a small fraction of
+Jahn-Teller-distorted Mn sites that are either antiferromagnetically ordered or
+unmagnetized. Thus the insulating samples are very similar to the behavior of
+the CMR samples up to the point at which the M/I transition occurs for the CMR
+materials. The lack of metallic conductivity for x <= 0.2, when 50% or more of
+the sample is magnetic, implies that there must be preferred magnetized Mn
+sites and that such sites do not percolate at these concentrations.",0708.1546v1
+2008-03-24,Effect of static and dynamic disorder on electronic transport of $RCo_2$ compounds: a study of $Ho(Al_xCo_{1-x})_2$ alloys,"We present experimental results on thermoelectric power ({\em S}) and
+electrical resistivity ($\rho $) of pseudobinary alloys
+Ho(Al$_x$Co$_{1-x}$)$_2$ ($0 \leq x \leq 0.1 $), in the temperature range 4.2 K
+to 300 K. The work focuses on the effects of static (induced by alloying) and
+dynamic (induced by temperature) disorder on the magnetic state and electronic
+transport in a metallic system with itinerant metamagnetic instability. Spatial
+fluctuations of the local magnetic susceptibility in the alloys lead to a
+development of a partially ordered magnetic ground state of the itinerant 3d
+electron system. This results in a strong increase of the residual resistivity
+and a suppression of the temperature-dependent resistivity. Thermopower
+exhibits a complex temperature variation in both the magnetically ordered and
+in the paramagnetic state. This complex temperature variation is referred to
+the electronic density of states features in vicinity of Fermi energy and to
+the interplay of magnetic and impurity scattering. Our results indicate that
+the magnetic enhancement of the Co 3d-band in RCo$_{\rm 2}$--based alloys upon
+a substitution of Co by non-magnetic elements is mainly related to a
+progressive localization of the Co -- 3d electrons caused by disorder. We show
+that the magnitude of the resistivity jump at the Curie temperature for
+RCo$_{\rm 2}$ compounds exhibiting a first order phase transition is a
+non-monotonic function of the Curie temperature due to a saturation of the
+3d--band spin fluctuation magnitude at high temperatures.",0803.3380v3
+2008-06-03,Magnetic Anomalies in a New Manganocuprate Gd3Ba2Mn2Cu2O12,"The manganocuprate compound Gd3Ba2Mn2Cu2O12 (Gd-3222) has been synthesized by
+conventional solid state reaction method and its magnetic behavior has been
+studied by dc and ac magnetization (M) and heat capacity (C) measurements as a
+function of temperature (T). This compound crystallizes in a tetragonal
+structure (space group I4/mmm). We find that this compound exhibits three
+magnetic transitions, around 2.5, 4.8 and 9 K, as inferred from dc and ac
+magnetic susceptibility (chi) data. However, no evidence for a well-defined
+lambda-anomaly is found in C(T) above 1.8 K, though there is a gradual upturn
+below about 10 K. An application of a magnetic field results in a peak around
+5K, while ac chi appears to show a very weak frequency dependence below 9 K.
+Isothermal M curve at 1.8 K exhibits a weak hysteresis without any evidence for
+saturation even at fields as high as 120 kOe. These results imply that this
+compound undergoes a spin-glass-like freezing at low temperatures, though the
+exact nature of the magnetic transition at 10 K is not clear. The magnitude of
+the magnetocaloric effect, as inferred from M and C data, is quite large over a
+wide temperature range below 50 K peaking around 4 K.",0806.0456v1
+2008-10-14,Field induced magnetic order in the frustrated magnet Gadolinium Gallium Garnet,"Gd3Ga5O12, (GGG), has an extraordinary magnetic phase diagram, where no long
+range order is found down to 25 mK despite \Theta_CW \approx 2 K. However, long
+range order is induced by an applied field of around 1 T. Motivated by recent
+theoretical developments and the experimental results for a closely related
+hyperkagome system, we have performed neutron diffraction measurements on a
+single crystal sample of GGG in an applied magnetic field. The measurements
+reveal that the H-T phase diagram of GGG is much more complicated than
+previously assumed. The application of an external field at low T results in an
+intensity change for most of the magnetic peaks which can be divided into three
+distinct sets: ferromagnetic, commensurate antiferromagnetic, and
+incommensurate antiferromagnetic. The ferromagnetic peaks (e.g. (112), (440)
+and (220)) have intensities that increase with the field and saturate at high
+field. The antiferromagnetic reflections have intensities that grow in low
+fields, reach a maximum at an intermediate field (apart from the (002) peak
+which shows two local maxima) and then decrease and disappear above 2 T. These
+AFM peaks appear, disappear and reach maxima in different fields. We conclude
+that the competition between magnetic interactions and alternative ground
+states prevents GGG from ordering in zero field. It is, however, on the verge
+of ordering and an applied magnetic field can be used to crystallise ordered
+components. The range of ferromagnetic and antiferromagnetic propagation
+vectors found reflects the complex frustration in GGG.",0810.2410v1
+2009-10-28,Fluctuation dynamo based on magnetic reconnections,"We develop a new model of the fluctuation dynamo in which the magnetic field
+is confined to thin flux ropes advected by a multi-scale flow which models
+turbulence. Magnetic dissipation occurs only via reconnections of flux ropes.
+The model is particularly suitable for rarefied plasma, such as the Solar
+corona or galactic halos. We investigate the kinetic energy release into heat,
+mediated by dynamo action, both in our model and by solving the induction
+equation with the same flow. We find that the flux rope dynamo is more than an
+order of magnitude more efficient at converting mechanical energy into heat.
+The probability density of the magnetic energy released during reconnections
+has a power-law form with the slope -3, consistent with the Solar corona
+heating by nanoflares. We also present a nonlinear extension of the model. This
+shows that a plausible saturation mechanism of the fluctuation dynamo is the
+suppression of turbulent magnetic diffusivity, due to suppression of random
+stretching at the location of the flux ropes. We confirm that the probability
+distribution function of the magnetic line curvature has a power-law form
+suggested by (Schekochihin et al., 2002). We argue, however, using our results
+that this does not imply a persistent folded structure of magnetic field, at
+least in the nonlinear stage.",0910.5392v2
+2009-11-23,Magnetic anisotropy determination and magnetic hyperthermia properties of small Fe nanoparticles in the superparamagnetic regime,"We report on the magnetic and hyperthermia properties of iron nanoparticles
+synthesized by organometallic chemistry. They are 5.5 nm in diameter and
+display a saturation magnetization close to the bulk one. Magnetic properties
+are dominated by the contribution of aggregates of nanoparticles with respect
+to individual isolated nanoparticles. Alternative susceptibility measurements
+are been performed on a low interacting system obtained after eliminating the
+aggregates by centrifugation. A quantitative analysis using the Gittleman s
+model allow a determination of the effective anisotropy Keff = 1.3 * 10^5
+J.m^{-3}, more than two times the magnetocristalline value of bulk iron.
+Hyperthermia measurements are performed on agglomerates of nanoparticles at a
+magnetic field up to 66 mT and at frequencies in the range 5-300 kHz. Maximum
+measured SAR is 280 W/g at 300 kHz and 66 mT. Specific absorption rate (SAR)
+displays a square dependence with the magnetic field below 30 mT but deviates
+from this power law at higher value. SAR is linear with the applied frequency
+for mu_0H=19 mT. The deviations from the linear response theory are discussed.
+A refined estimation of the optimal size of iron nanoparticles for hyperthermia
+applications is provided using the determined effective anisotropy value.",0911.4413v1
+2010-02-02,"Magnetic anisotropy of epitaxial (Ga,Mn)As on (113)A GaAs","The temperature dependence of magnetic anisotropy in (113)A (Ga,Mn)As layers
+grown by molecular beam epitaxy is studied by means of superconducting quantum
+interference device (SQUID) magnetometry as well as by ferromagnetic resonance
+(FMR) and magnetooptical effects. Experimental results are described
+considering cubic and two kinds of uniaxial magnetic anisotropy. The magnitude
+of cubic and uniaxial anisotropy constants is found to be proportional to the
+fourth and second power of saturation magnetization, respectively. Similarly to
+the case of (001) samples, the spin reorientation transition from uniaxial
+anisotropy with the easy along the [-1, 1, 0] direction at high temperatures to
+the biaxial <100> anisotropy at low temperatures is observed around 25 K. The
+determined values of the anisotropy constants have been confirmed by FMR
+studies. As evidenced by investigations of the polar magnetooptical Kerr
+effect, the particular combination of magnetic anisotropies allows the
+out-of-plane component of magnetization to be reversed by an in-plane magnetic
+field. Theoretical calculations within the p-d Zener model explain the
+magnitude of the out-of-plane uniaxial anisotropy constant caused by epitaxial
+strain, but do not explain satisfactorily the cubic anisotropy constant. At the
+same time the findings point to the presence of an additional uniaxial
+anisotropy of unknown origin. Similarly to the case of (001) films, this
+additional anisotropy can be explained by assuming the existence of a shear
+strain. However, in contrast to the (001) samples, this additional strain has
+an out-of-the-(001)-plane character.",1002.0563v2
+2011-02-25,Dynamo in the Intra-Cluster Medium: Simulation of CGL-MHD Turbulent Dynamo,"The standard magnetohydrodynamic (MHD) description of the plasma in the hot,
+magnetized gas of the intra-cluster (ICM) medium is not adequate because it is
+weakly collisional. In such collisionless magnetized gas, the microscopic
+velocity distribution of the particles is not isotropic, giving rise to kinetic
+effects on the dynamical scales. These kinetic effects could be important in
+understanding the turbulence, as so as the amplification and maintenance of the
+magnetic fields in the ICM. It is possible to formulate fluid models for
+collisonless or weakly collisional gas by introducing modifications in the MHD
+equations. These models are often referred as kinetic MHD (KMHD). Using a KMHD
+model based on the CGL-closure, which allows the adiabatic evolution of the two
+components of the pressure tensor (the parallel and perpendicular components
+with respect to the local magnetic field), we performed 3D numerical
+simulations of forced turbulence in order to study the amplification of an
+initially weak seed magnetic field. We found that the growth rate of the
+magnetic energy is comparable to that of the ordinary MHD turbulent dynamo, but
+the magnetic energy saturates in a level smaller than of the MHD case. We also
+found that a necessary condition for the dynamo works is to impose limits to
+the anisotropy of the pressure.",1102.5139v1
+2011-12-20,The Ly-alpha Lines of H I and He II: A Differential Hanle Effect for Exploring the Magnetism of the Solar Transition Region,"The Ly-alpha line of He II at 304 \AA\ is one of the spectral lines of choice
+for EUV channels of narrow-band imagers on board space telescopes, which
+provide spectacular intensity images of the outer solar atmosphere. Since the
+magnetic field information is encoded in the polarization of the spectral line
+radiation, it is important to investigate whether the He II line radiation from
+the solar disk can be polarized, along with its magnetic sensitivity. Here we
+report some theoretical predictions concerning the linear polarization signals
+produced by scattering processes in this strong emission line of the solar
+transition region, taking into account radiative transfer and the Hanle effect
+caused by the presence of organized and random magnetic fields. We find that
+the fractional polarization amplitudes are significant (${\sim}1%$), even when
+considering the wavelength-integrated signals. Interestingly, the scattering
+polarization of the Ly-alpha line of He II starts to be sensitive to the Hanle
+effect for magnetic strengths B>100 G (i.e., for magnetic strengths of the
+order of and larger than the Hanle saturation field of the hydrogen Ly-alpha
+line at 1216 \AA). We therefore propose simultaneous observations of the
+scattering polarization in both Ly-alpha lines to facilitate magnetic field
+measurements in the upper solar chromosphere. Even the development of a
+narrow-band imaging polarimeter for the He II 304 \AA\ line alone would be
+already of great diagnostic value for probing the solar transition region.",1112.4746v1
+2012-01-13,Preisach images of a simple mechanical system,"This work is an an early stage of a larger project aiming at answering the
+question whether or not the Preisach map is really fingerprinting magnetic
+materials. More precisely, we are interested whether Preisach model of magnetic
+hysteresis indeed contains any physics or is just a convenient modeling tool.
+To this extent we study a very simple mechanical system, thus fully tractable,
+subjected to the external force. Despite of its simplicity, our model captures
+all the fundamental features of real magnetic materials, namely their
+hysteretic behavior, coercivity, remanent magnetization and saturation at high
+fields. Both the overall shape of major hysteresis loop as well as First Order
+Reversal Curves (FORC's) are reproduced quite correctly; they are very similar
+to those observed in magnetic materials. The model essentially consists of a
+single, spring loaded, rigid and rotative bar with non-zero friction torque.
+The length of a projection of this bar onto the direction of an external force
+is identified with magnetization. The friction torque and the spring constant
+are the only freely adjustable parameters of our model. Here we investigate,
+and present, their influence on the inferred Preisach maps.",1201.2811v1
+2012-07-09,Coronal Structure of Low-Mass Stars,"We investigate the change in stellar magnetic topology across the
+fully-convective boundary and its effects on coronal properties. We consider
+both the magnitude of the open flux that influences angular momentum loss in
+the stellar wind and X-ray emission measure. We use reconstructed maps of the
+radial magnetic field at the stellar surface and the potential-field source
+surface method to extrapolate a 3D coronal magnetic field for a sample of
+early-to-mid M dwarfs. During the magnetic reconstruction process it is
+possible to force a solution towards field geometries that are symmetric or
+antisymmetric about the equator but we demonstrate that this has only a modest
+impact on the coronal tracers mentioned above. We find that the dipole
+component of the field, which governs the large-scale structure, becomes
+increasingly strong as the stellar mass decreases, while the magnitude of the
+open (wind-bearing) magnetic flux is proportional to the magnitude of the
+reconstructed magnetic flux. By assuming a hydrostatic and isothermal corona we
+calculate X-ray emission measures (in magnitude and rotational modulation) for
+each star and, using observed stellar densities as a constraint, we reproduce
+the observed X-ray saturation at Ro < 0.1. We find that X-ray rotational
+modulation is not a good indicator of magnetic structure as it shows no trend
+with Rossby number but can be useful in discriminating between different
+assumptions on the field geometry.",1207.2165v1
+2012-12-12,Ferrimagnetism and spin canting of ZnFe2O4 nanoparticles embedded in ZnO matrix,"The structural and magnetic properties of ZnFe2O4 nanoparticles embedded in a
+non-magnetic ZnO matrix are presented. X-ray diffractograms and Transmission
+Electron Microscopy (TEM) images showed that the resulting samples are composed
+of crystalline ferrite nanoparticles with average crystallite size <D> =
+23.4(0.9) nm, uniformly dispersed within the ZnO matrix. Magnetization data
+indicated a superparamagnetic-like behavior from room temperature down to T_{M}
+~ 20 K, where a transition to a frozen state is observed. The M(H) curves
+displayed nearly zero coercive field down to TM, where a sharp increase in the
+H_C value is observed. The measured saturation magnetization M_S values at 200
+and 2 K were M_S = 0.028(3) and 0.134(7) muB/f.u. ZnFe2O4 respectively, showing
+the existence of small amounts of non compensated atomic moments. M\""ossbauer
+measurements at low temperatures confirmed the transition to a magnetically
+ordered state for T < 25 K, where two magnetically split sextets develop.
+Whereas these two sextets show strong overlap due to the similar hyperfine
+fields, in-field M\""ossbauer spectra clearly showed two different Fe3+ sites,
+demonstrating that the sample is ferrimagnetically ordered. The two spinel
+sites are found to behave differently under an external field of 12 T: whereas
+the moments located at A sites show a perfect alignment with the external
+field, spins at B sites are canted by an angle alpha_B = 49(2){\deg}. We
+discuss the significance of this particle structure for the observed magnetic
+behavior.",1212.2798v1
+2013-01-22,The Maximum Energy of Accelerated Particles in Relativistic Collisionless Shocks,"The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as
+synchrotron radiation from electrons accelerated at the GRB external shock,
+that propagates with relativistic velocities into the magnetized interstellar
+medium. By means of multi-dimensional particle-in-cell simulations, we
+investigate the acceleration performance of weakly magnetized relativistic
+shocks, in the magnetization range 0<sigma<1e-1. The pre-shock magnetic field
+is orthogonal to the flow, as generically expected for relativistic shocks. We
+find that relativistic perpendicular shocks propagating in electron-positron
+plasmas are efficient particle accelerators if the magnetization is sigma<1e-3.
+For electron-ion plasmas, the transition to efficient acceleration occurs for
+sigma<3e-5. Here, the acceleration process proceeds similarly for the two
+species, since the electrons enter the shock nearly in equipartition with the
+ions, as a result of strong pre-heating in the self-generated upstream
+turbulence. In both electron-positron and electron-ion shocks, we find that the
+maximum energy of the accelerated particles scales in time as t^(1/2). This
+scaling is shallower than the so-called (and commonly assumed) Bohm limit, and
+it naturally results from the small-scale nature of the Weibel turbulence
+generated in the shock layer. In magnetized plasmas, the energy of the
+accelerated particles increases until it reaches a saturation value that scales
+with the magnetization as sigma^(-1/4). Further energization is prevented by
+the fact that the self-generated turbulence is confined within a finite region
+of thickness proportional to sigma^(-1/2) around the shock. Our results can
+provide physically-grounded inputs for models of non-thermal emission from a
+variety of astrophysical sources, with particular relevance to GRB afterglows.",1301.5333v1
+2013-06-03,Exact solution for quantum spin-1/2 Ising-Heisenberg orthogonal-dimer chain with the Heisenberg intra-dimer and Ising inter-dimer interactions,"The quantum spin-1/2 orthogonal-dimer chain with the Heisenberg intra-dimer
+and Ising inter-dimer interactions in a magnetic field is considered by a
+rigorous approach. The model conserves the z-component of total spin on
+vertical Heisenberg bonds and this property is used to calculate exactly the
+partition function using the transfer-matrix method. We have found the
+ground-state phase diagram of the given model in a magnetic field as well as
+the macroscopic degeneracy along field-induced transitions accompanied with the
+magnetization jumps. The model exhibits two intermediate fractional plateaux at
+one-quarter and one-half of the saturation magnetization. We have examined the
+effect of the exchange anisotropy in the XXZ Heisenberg intra-dimer interaction
+on the ground state. It is shown that the one-quarter and one-half plateaux may
+disappear from the magnetization curve for the ferromagnetic Heisenberg
+intra-dimer interaction. We have also rigorously studied the effect of
+frustrated interactions on the thermodynamic and magnetic properties of the
+model and show how the macroscopic degeneracy of the ground state is reflected
+in the low-temperature behavior of the magnetization, entropy and specific
+heat. A possibility of observing enhanced magnetocaloric effect during the
+adiabatic demagnetization is discussed in detail.",1306.0487v2
+2013-12-20,Exciton spin dynamics of colloidal CdTe nanocrystals in magnetic field,"The recombination and spin dynamics of excitons in colloidal CdTe
+nanocrystals (NCs) are studied by time-resolved photoluminescence in high
+magnetic fields up to 15 T and at cryogenic temperatures. The recombination
+decay shows a nonexponential temporal behavior, with the longest component
+corresponding to the dark excitons having 260 ns decay time at zero magnetic
+field and 4.2 K temperature. This long component shortens to 150 ns at 15 T due
+to the magnetic-field-induced mixing of the bright and dark exciton states. The
+spin dynamics, assessed through the evolution of the magnetic-field-induced
+circular polarization degree of the photoluminescence, has a fast component
+shorter than 1 ns related to the bright excitons and a slow component of 5-10
+ns associated with the dark excitons. The latter shortens with increasing
+magnetic field, which is characteristic for a phonon-assisted spin relaxation
+mechanism. The relatively low saturation level of the associated
+magnetic-field-induced circular polarization degree of -30 % is explained by a
+model that suggests the CdTe NCs to constitute an ensemble of prolate and
+oblate NCs, both having a structural quantization axis. The exciton g-factor of
+2.4-2.9 evaluated from fitting the experimental data in the frame of the
+suggested approach is in good agreement with the expected value for the dark
+excitons in CdTe NCs.",1312.5929v1
+2014-06-23,Anisotropic shear viscosity of a strongly coupled non-Abelian plasma from magnetic branes,"Recent estimates for the electromagnetic fields produced in the early stages
+of non-central ultra-relativistic heavy ion collisions indicate the presence of
+magnetic fields $B\sim \mathcal{O}(0.1-15\,m_\pi^2)$, where $m_\pi$ is the pion
+mass. It is then of special interest to study the effects of strong (Abelian)
+magnetic fields on the transport coefficients of strongly coupled non-Abelian
+plasmas, such as the quark-gluon plasma formed in heavy ion collisions. In this
+work we study the anisotropy in the shear viscosity induced by an external
+magnetic field in a strongly coupled $\mathcal{N} = 4$ SYM plasma. Due to the
+spatial anisotropy created by the magnetic field, the most general viscosity
+tensor of a magnetized plasma has 5 shear viscosity coefficients and 2 bulk
+viscosities. We use the holographic correspondence to evaluate two of the shear
+viscosities, $\eta_{\perp} \equiv \eta_{xyxy}$ (perpendicular to the magnetic
+field) and $\eta_{\parallel} \equiv \eta_{xzxz}=\eta_{yzyz}$ (parallel to the
+field). When $B\neq 0$ the shear viscosity perpendicular to the field saturates
+the viscosity bound $\eta_{\perp}/s = 1/(4\pi)$ while in the direction parallel
+to the field the bound is violated since $\eta_{\parallel}/s < 1/(4\pi)$.
+However, the violation of the bound in the case of strongly coupled SYM is
+minimal even for the largest value of $B$ that can be reached in heavy ion
+collisions.",1406.6019v2
+2015-01-16,State of Co and Mn in half-metallic ferromagnet Co$_2$MnSi explored by magnetic circular dichroism in hard X-ray photoelectron emission and soft X-ray absorption spectroscopies,"The half-metallic Heusler compound Co$_2$MnSi is a very attractive material
+for spintronic devices because it exhibits very high tunnelling
+magnetoresistance ratios. This work reports on a spectroscopic investigation of
+thin Co$_2$MnSi films as they are used as electrodes in magnetic tunnel
+junctions. The investigated films exhibit a remanent in-plane magnetisation
+with a magnetic moment of about 5~$\mu_B$ when saturated, as expected. The low
+coercive field of only 4~mT indicates soft magnetic behaviour. Magnetic
+dichroism in emission and absorption was measured at the Co and Mn $2p$ core
+levels. The photoelectron spectra were excited by circularly polarised hard
+X-rays with an energy of of 6~keV and taken from the remanently magnetised
+film. The soft X-ray absorption spectra were taken in an induction field of
+4~T. Both methods yielded large dichroism effects. An analysis reveals the
+localised character of the electrons and magnetic moments attributed to the Mn
+atoms, whereas the electrons related to the Co atoms contribute an itinerant
+part to the total magnetic moment.",1501.03966v1
+2015-06-29,Frustrated magnetic planes with intricate interaction pathways in the mineral langite Cu$_4$(OH)$_6$SO$_4\cdot 2$H$_2$O,"Magnetic and crystallographic properties of the mineral langite
+Cu$_4$(OH)$_6$SO$_4\cdot 2$H$_2$O are reported. Its layered crystal structure
+features a peculiar spatial arrangement of spin-$\frac12$ Cu$^{2+}$ ions that
+arises from a combination of corner- and edge-sharing chains. Experimentally,
+langite orders antiferromagnetically at $T_N\simeq 5.7$ K as revealed by
+magnetization and specific heat measurements. Despite this very low energy
+scale of the magnetic transition, langite features significantly stronger
+couplings on the order of 50-70 K. Half of the Cu$^{2+}$ spins are weakly
+coupled and saturate around 12T, where the magnetization reaches 0.5$\mu_B$/Cu.
+These findings are rationalized by density-functional band-structure
+calculations suggesting a complex interplay of frustrated exchange couplings in
+the magnetic planes. A simplified model of coupled magnetic sublattices
+explains the experimental features qualitatively. To start from reliable
+structural data, the crystal structure of langite in the 100-280 K temperature
+range has been determined by single-crystal x-ray diffraction, and the hydrogen
+positions were refined computationally.",1506.08562v3
+2015-07-23,Negative Magnetoresistance in Dirac Semimetal Cd3As2,"A large negative magnetoresistance is anticipated in topological semimetals
+in the parallel magnetic and electric field configuration as a consequence of
+the nontrivial topological properties. The negative magnetoresistance is
+believed to demonstrate the chiral anomaly, a long-sought high-energy physics
+effect, in solid-state systems. Recent experiments reveal that Cd3As2, a Dirac
+topological semimetal, has the record-high mobility and exhibits positive
+linear magnetoresistance in the orthogonal magnetic and electric field
+configuration. However, the negative magnetoresistance in the parallel magnetic
+and electric field configuration remains unveiled. Here, we report the
+observation of the negative magnetoresistance in Cd3As2 microribbons in the
+parallel magnetic and electric field configuration as large as 66% at 50 K and
+even visible at room temperatures. The observed negative magnetoresistance is
+sensitive to the angle between magnetic and electrical field, robust against
+temperature, and dependent on the carrier density. We have found that carrier
+densities of our Cd3As2 samples obey an Arrhenius's law, decreasing from
+3.0x10^17 cm^-3 at 300 K to 2.2x10^16 cm^-3 below 50 K. The low carrier
+densities result in the large values of the negative magnetoresistance. We
+therefore attribute the observed negative magnetoresistance to the chiral
+anomaly. Furthermore, in the perpendicular magnetic and electric field
+configuration a positive non-saturating linear magnetoresistance up to 1670% at
+14 T and 2 K is also observed. This work demonstrates potential applications of
+topological semimetals in magnetic devices.",1507.06470v1
+2015-08-10,Efficiency of Super-Eddington Magnetically-Arrested Accretion,"The radiative efficiency of super-Eddington accreting black holes (BHs) is
+explored for magnetically-arrested disks (MADs), where magnetic flux builds-up
+to saturation near the BH. Our three-dimensional general relativistic radiation
+magnetohydrodynamic (GRRMHD) simulation of a spinning BH (spin $a/M=0.8$)
+accreting at $\sim 50$ times Eddington shows a total efficiency $\sim 50\%$
+when time-averaged and total efficiency $\gtrsim 100\%$ in moments. Magnetic
+compression by the magnetic flux near the rotating BH leads to a thin disk,
+whose radiation escapes via advection by a magnetized wind and via transport
+through a low-density channel created by a Blandford-Znajek (BZ) jet. The BZ
+efficiency is sub-optimal due to inertial loading of field lines by optically
+thick radiation, leading to BZ efficiency $\sim 40\%$ on the horizon and BZ
+efficiency $\sim 5\%$ by $r\sim 400r_g$ (gravitational radii) via absorption by
+the wind. Importantly, radiation escapes at $r\sim 400r_g$ with efficiency
+$\eta\approx 15\%$ (luminosity $L\sim 50L_{\rm Edd}$), similar to $\eta\approx
+12\%$ for a Novikov-Thorne thin disk and beyond $\eta\lesssim 1\%$ seen in
+prior GRRMHD simulations or slim disk theory. Our simulations show how BH spin,
+magnetic field, and jet mass-loading affect the radiative and jet efficiencies
+of super-Eddington accretion.",1508.02433v1
+2015-09-11,Theoretical investigation of the behavior of CuSe2O5 compound in high magnetic fields,"Based on analytical and numerical approaches, we investigate thermodynamic
+properties of CuSe2O5 at high magnetic fields which is a candidate for the
+strong intra-chain interaction in quasi one-dimensional (1D) quantum magnets.
+Magnetic behavior of the system can be described by the 1D spin-1/2 XXZ model
+in the presence of the Dzyaloshinskii-Moriya (DM) interaction. Un- der these
+circumstances, there is one quantum critical field in this compound. Below the
+quantum critical field the spin chain system is in the gapless Luttinger liquid
+(LL) regime, whereas above it one observes a crossover to the gapped saturation
+magnetic phase. Indications on the thermodynamic curves confirm the occurrence
+of such a phase transition. The main characteristics of the LL phase are
+gapless and spin-spin correlation functions decay algebraic. The effects of
+zero-temperature quantum phase transition are observed even at rather high
+temperatures in comparison with the counterpart compounds. In addition, we
+calculate the Wilson ratio in the model. The Wilson ratio at a fixed
+temperature remains almost independent of the field in the LL region. In the
+vicinity of the quantum critical field, the Wilson ratio increases and exhibits
+anomalous enhancement.",1509.03414v1
+2016-02-17,Modeling of screening currents in coated conductor magnets containing up to 40000 turns,"Screening currents caused by varying magnetic fields degrade the homogeneity
+and stability of the magnetic fields created by $RE$BCO coated conductor coils.
+They are responsible for the AC loss, which is also important for other power
+applications containing windings. Since real magnets contain coils exceeding
+10000 turns, accurate modeling tools for this number of turns are necessary for
+magnet design. This article presents a fast numerical method to model coils
+with no loss of accuracy. We model a 10400-turn coil for its real geometry and
+coils of up to 40000 turns with the continuous approximation, which we checked
+that introduces negligible errors. The screening currents, the Screening
+Current Induced Field (SCIF) and the AC loss is analyzed in detail. The SCIF is
+maximum at the remnant state with a considerably large value and decreases
+substantially after one day of relaxation. The instantaneous AC loss for an
+anisotropic magnetic-field dependent $J_c$ is qualitatively different than for
+a constant $J_c$, although the loss per cycle is similar. Saturation of the
+magnetization currents at the end pancakes causes that the maximum AC loss at
+the first ramp increases with $J_c$. The presented modeling tool can accurately
+calculate the SCIF and AC loss in practical computing times for coils with any
+number of turns used in real windings, enabling parameter optimization.",1602.05433v2
+2016-03-15,Instability of Non-uniform Toroidal Magnetic Fields in Accretion Disks,"A new type of instability that is expected to drive magnetohydrodynamic (MHD)
+turbulence from a purely toroidal magnetic field in an accretion disk is
+presented. It is already known that in a differentially rotating system, the
+uniform toroidal magnetic field is unstable due to a magnetorotational
+instability (MRI) under a non-axisymmetric and vertical perturbation, while it
+is stable under a purely vertical perturbation. Contrary to the previous study,
+this paper proposes an unstable mode completely confined to the equatorial
+plane, driven by the expansive nature of the magnetic pressure gradient force
+under a non-uniform toroidal field. The basic nature of this growing eigenmode,
+to which we give a name ""magneto-gradient driven instability"", is studied using
+linear analysis, and the corresponding nonlinear evolution is then investigated
+using two-dimensional ideal MHD simulations. Although a single localized
+magnetic field channel alone cannot provide sufficient Maxwell stress to
+contribute significantly to the angular momentum transport, we find that the
+mode coupling between neighboring toroidal fields under multiple localized
+magnetic field channels drastically generates a highly turbulent state and
+leads to the enhanced transport of angular momentum, comparable to the
+efficiency seen in previous studies on MRIs. This horizontally confined mode
+may play an important role in the saturation of an MRI through complementray
+growth with the toroidal MHDs and coupling with magnetic reconnection.",1603.04638v1
+2016-03-15,Kinetic simulations of the lowest-order unstable mode of relativistic magnetostatic equilibria,"We present the results of particle-in-cell numerical pair plasma simulations
+of relativistic 2D magnetostatic equilibria known as the 'ABC' fields. In
+particular, we focus on the lowest-order unstable configuration consisting of
+two minima and two maxima of the magnetic vector potential. Breaking of the
+initial symmetry leads to exponential growth of the electric energy and to the
+formation of two current layers, which is consistent with the picture of
+'X-point collapse' first described by Syrovatskii. Magnetic reconnection within
+the layers heats a fraction of particles to very high energies. After the
+saturation of the linear instability, the current layers are disrupted and the
+system evolves chaotically, diffusing the particle energies in a stochastic
+second-order Fermi process leading to the formation of power-law energy
+distributions. The power-law slopes harden with the increasing mean
+magnetization, but they are significantly softer than those produced in
+simulations initiated from Harris-type layers. The maximum particle energy is
+proportional to the mean magnetization, which is attributed partly to the
+increase of the effective electric field and partly to the increase of the
+acceleration time scale. We describe in detail the evolving structure of the
+dynamical current layers, and report on the conservation of magnetic helicity.
+These results can be applied to highly magnetized astrophysical environments,
+where ideal plasma instabilities trigger rapid magnetic dissipation with
+efficient particle acceleration and flares of high-energy radiation.",1603.04850v1
+2016-08-18,Turbulent dynamo in a conducting fluid and partially ionized gas,"By following the Kazantsev theory and taking into account both microscopic
+and turbulent diffusion of magnetic fields, we develop a unified treatment of
+the kinematic and nonlinear stages of turbulent dynamo, and study the dynamo
+process for a full range of magnetic Prandtl number Pm and ionization
+fractions. We find a striking similarity between the dependence of dynamo
+behavior on Pm in a conducting fluid and R (a function of ionization fraction)
+in partially ionized gas. In a weakly ionized medium, the kinematic stage is
+largely extended, including not only exponential growth but a new regime of
+dynamo characterized by linear-in-time growth of magnetic field strength, and
+the resulting magnetic energy is much higher than the kinetic energy carried by
+viscous-scale eddies. Unlike the kinematic stage, the subsequent nonlinear
+stage is unaffected by microscopic diffusion processes and has a universal
+linear-in-time growth of magnetic energy with the growth rate as a constant
+fraction $3/38$ of the turbulent energy transfer rate, showing good agreement
+with earlier numerical results. Applying the analysis to the first stars and
+galaxies, we find that the kinematic stage is able to generate a field strength
+only an order of magnitude smaller than the final saturation value. But the
+generation of large-scale magnetic fields can only be accounted for by the
+relatively inefficient nonlinear stage and requires longer time than the
+free-fall time. It suggests that magnetic fields may not have played a
+dynamically important role during the formation of the first stars.",1608.05161v2
+2016-09-06,Universal fluctuations in orbital diamagnetism: A surprise in theoretical physics,"Over the last century Bohr van Leuween theorem attracted the notice of
+physicists. The theorem states about the absence of magnetization in classical
+systems in thermal equilibrium. In this paper, we discuss about fluctuations of
+magnetic moment in classical systems. In recent years this topic has been
+investigated intensively and it is not free from controversy. We a have
+considered a system consisting of a single particle moving in a plane. A
+magnetic field is applied perpendicular to the plane. The system is in contact
+with a thermal bath. We have considered three cases: (a) particle moving in a
+homogeneous medium, (b) particle moving in a medium with space dependent
+friction and (c) particle moving in a medium with space dependent temperature.
+For all the three cases average magnetic moment and fluctuations in magnetic
+moment has been calculated. Average magnetic moment saturates to a finite value
+in case of free particle but goes to zero when the particle is confined by a
+2-D harmonic potential. Fluctuations in magnetic moment shows universal
+features in the presence of arbitrary friction inhomogeneity. For this case the
+system reaches equilibrium asymptotically. In case of space dependent
+temperature profile, the stationary distribution is non-Gibbsian and
+fluctuations deviate from universal value for the bounded system only.",1609.01603v1
+2017-04-11,Prediction of helium vapor quality in steady state Two-phase operation for SST-1 Toroidal field magnets,"Steady State Superconducting Tokamak (SST-1) at the Institute for Plasma
+Research (IPR) is an operational device and is the first superconducting
+Tokamak in India. Superconducting Magnets System (SCMS) in SST-1 comprises of
+sixteen Toroidal field (TF) magnets and nine Poloidal Field (PF) magnets
+manufactured using NbTi/Cu based cable-in-conduit-conductor (CICC) concept.
+SST-1, superconducting TF magnets are operated in a Cryo-stable manner being
+cooled with two-phase (TP) flow helium. The typical operating pressure of the
+TP helium is 1.6 bar (a) at corresponding saturation temperature. The SCMS has
+a typical cool-down time of about 14 days from 300 K down to 4.5 K using Helium
+plant of equivalent cooling capacity of 1350 W at 4.5 K. Using the onset of
+experimental data from the HRL, we estimated the vapor quality for the input
+heat load on to the TF magnets system. In this paper, we report the
+characteristics of two-phase flow for given thermo-hydraulic conditions during
+long steady state operation of the SST-1 TF magnets. Finally, the
+experimentally obtained results have been compared with the well-known
+correlations of two-phase flow.",1704.08107v2
+2017-04-27,Are chains of type I radio bursts generated by similar processes as drifting pulsation structures observed during solar flares?,"We present examples of the both types of bursts and show their similarities
+and differences. Then for chains of type I bursts a similar model as for
+drifting pulsation structures (DPSs) is proposed. We show that similarly as in
+the DPS, the chains of type I bursts can be generated by the fragmented
+magnetic reconnection associated with plasmoids interactions. To support this
+new model of chains of type I bursts, we present an effect of merging of two
+plasmoids to one larger plasmoid on the radio spectrum of DPS. This process can
+also explain the ""wavy"" appearance of some chains of type I bursts. Then we
+show that the chains of type I bursts with the ""wavy"" appearance can be used
+for estimation of the magnetic field strength in their sources. We think that
+differences of chains of type I bursts and DPSs are mainly owing to different
+regimes of the magnetic field reconnection. While in the case of chains of type
+I bursts the magnetic reconnection and plasmoid interactions are in the
+quasi-separatrix layer of the active region in more or less quasi-saturated
+regime, in the case of DPSs, observed in the impulsive phase of eruptive
+flares, the magnetic reconnection and plasmoids interactions are in the current
+sheet formed under the flare magnetic rope, which moves upwards and forces this
+magnetic reconnection.",1704.08532v1
+2017-06-16,"Magnetic order, hysteresis and phase coexistence in magnetoelectric LiCoPO$_4$","The magnetic phase diagram of magnetoelectric LiCoPO$_4$ is established using
+neutron diffraction and magnetometry in fields up to 25.9T applied along the
+crystallographic $b$-axis. For fields greater than 11.9T the magnetic unit cell
+triples in size with propagation vector Q = (0, 1/3, 0). A magnetized elliptic
+cycloid is formed with spins in the $(b,c)$-plane and the major axis oriented
+along $b$. Such a structure allows for the magnetoelectric effect with an
+electric polarization along $c$ induced by magnetic fields applied along $b$.
+Intriguingly, additional ordering vectors Q $\approx$ (0, 1/4, 0) and Q
+$\approx$ (0, 1/2, 0) appear for increasing fields in the hysteresis region
+below the transition field. Traces of this behavior are also observed in the
+magnetization. A simple model based on a mean-field approach is proposed to
+explain these additional ordering vectors. In the field interval 20.5-21.0T,
+the propagation vector Q = (0, 1/3, 0) remains but the spins orient differently
+compared to the cycloid phase. Above 21.0T and up until saturation a
+commensurate magnetic structure exists with a ferromagnetic component along $b$
+and an antiferromagnetic component along $c$.",1706.05203v2
+2017-10-27,"Near total magnetic moment compensation without reduction in T_C of Mn_2 V_0.5 Co_0.5 Z (Z=Ga,Al) Heusler compounds","Mn_2V_1-xCo_xZ (Z=Ga,Al and x=0, 0.25, 0.5, 0.75, 1) Heusler compounds have
+been synthesized to investigate the effect of Co substitution at the V site on
+the magnetic moment and Curie temperatures of half-metallic ferrimagnets
+Mn_2VGa and Mn_2VAl. The Co substituted compounds show a non linear decrease in
+lattice parameter without altering the crystal structure of the parent
+compounds. The end members Mn_2VGa and Mn_2CoGa have the saturation
+magnetization of 1.80 {\mu}_B/f.u and 2.05 {\mu}_B/f.u respectively whereas for
+the Mn_2V_0.5Co_0.5Ga compound, a near total magnetic moment compensation (0.10
+{\mu}_B/f.u) was observed due to the ferrimagnetic coupling of Mn with
+parallelly aligned V and Co. The Co substituted Mn_2VAl has also shown the
+similar trend with compensated magnetic moment value of 0.06 {\mu}_B/f.u for
+x=0.5. The Curie temperatures of the compounds including the x=0.5 composition
+are well above the room temperature (more than 700 K) which is in sharp
+contrast to the earlier reported values of 171 K for the (MnCo)VGa and 105 K
+for the (MnCo)VAl compounds (substitution at the Mn site). The magnetic moment
+compensation without significant reduction in T_C indicates that the V site
+substitution of Co does not weaken the magnetic interaction in Mn_2VZ (Z=Ga,
+Al) compounds which is in contrary to the earlier experimental reports on Mn
+site substitution.",1710.09971v1
+2018-05-29,Spin-Hall magnetoresistance in a low-dimensional magnetic insulator,"We observe an unusual behavior of the spin Hall magnetoresistance (SMR)
+measured in a Pt ultra-thin film deposited on a ferromagnetic insulator, which
+is a tensile-strained LaCoO3 (LCO) thin film with the Curie temperature Tc=85K.
+The SMR displays a strong magnetic-field dependence below Tc, with the SMR
+amplitude continuing to increase (linearly) with increasing the field far
+beyond the saturation value of the ferromagnet. The SMR amplitude decreases
+gradually with raising the temperature across Tc and remains measurable even
+above Tc. Moreover, no hysteresis is observed in the field dependence of the
+SMR. These results indicate that a novel low-dimensional magnetic system forms
+on the surface of LCO and that the Pt/LCO interface decouples magnetically from
+the rest of the LCO thin film. To explain the experiment, we revisit the
+derivation of the SMR corrections and relate the spin-mixing conductances to
+the microscopic quantities describing the magnetism at the interface. Our
+results can be used as a technique to probe quantum magnetism on the surface of
+a magnetic insulator.",1805.11225v2
+2019-03-12,High-magnetic field phase diagram and failure of magnetic Grüneisen scaling in LiFePO$_4$,"We report the magnetic phase diagram of single-crystalline LiFePO$_4$ in
+magnetic fields up to 58~T and present a detailed study of magneto-elastic
+coupling by means of high-resolution capacitance dilatometry. Large anomalies
+at \tn\ in the thermal expansion coefficient $\alpha$ imply pronounced
+magneto-elastic coupling. Quantitative analysis yields the magnetic Gr\""uneisen
+parameter $\gamma_{\rm mag}=6.7(5)\cdot 10^{-7}$~mol/J. The positive
+hydrostatic pressure dependence $dT_{\rm N}/dp = 1.46(11)$~K/GPa is dominated
+by uniaxial effects along the $a$-axis. Failure of Gr\""uneisen scaling below
+$\approx 40$~K, i.e., below the peak temperature in the magneto-electric
+coupling coefficient [\onlinecite{toft2015anomalous}], implies several
+competing degrees of freedom and indicates relevance of recently observed
+hybrid excitations~[\onlinecite{yiu2017hybrid}]. A broad and strongly
+magnetic-field-dependent anomaly in $\alpha$ in this temperature regime
+highlight the relevance of structure changes. Upon application of magnetic
+fields $B||b$-axis, a pronounced jump in the magnetisation implies
+spin-reorientation at $B_{\rm SF} = 32$~T as well as a precursing phase at 29~T
+and $T=1.5$~K. In a two-sublattice mean-field model, the saturation field
+$B_{\rm sat,b} = 64(2)$~T enables the determination of the effective
+antiferromagnetic exchange interaction $J_{\rm af} = 2.68(5)$~meV as well as
+the anisotropies $D_{\rm b} = -0.53(4)$~meV and $D_{\rm c} = 0.44(8)$~meV.",1903.05169v1
+2019-09-10,Magnetic phase diagram of a spin S=1/2 antiferromagnetic two-leg ladder in the presence of modulated along legs Dzyaloshinskii-Moriya interaction,"We study the ground-state magnetic phase diagram of a spin S=1/2
+antiferromagnetic two-leg ladder in the presence of period two lattice units
+modulated, Dzyaloshinskii-Moriya (DM) interaction along the legs. We consider
+the case of collinear DM vectors and strong rung exchange and magnetic field.
+In this limit we map the initial ladder model onto the effective spin
+$\sigma=1/2$ XXZ chain and study the latter using the continuum-limit
+bosonization approach. We identified four quantum phase transitions and
+corresponding critical magnetic fields, which mark transitions from the spin
+gapped regimes into the gapless quantum spin-liquid regimes. In the gapped
+phases the magnetization curve of the system shows plateaus at magnetisation
+M=0 and to its saturation value per rung M=1. We have shown that the very
+presence of alternating DM interaction leads to opening of a gap in the
+excitation spectrum at magnetization M=0.5. The width of the magnetization
+plateau at M=0.5, is determined by the associated with the dynamical generation
+of a gap in the spectrum is calculated and is shown that its length scales as
+$(D_{0}D_{1}/J^{2})^{\alpha}$ where $D_{0},D_{1}$ are uniform and staggered
+components of the DM term, $J$ is the intraleg exchange and $\alpha \leq 3/4$
+and weakly depends on the DM couplings.",1909.04618v1
+2019-12-11,Magnetic field effects on electron transport in nanoring with orbital Rashba coupling,"We study the effects of a Zeeman magnetic field on the electron transport of
+one-dimensional quantum rings which are marked by electronic states with
+$d-$orbital symmetry in the presence of spin-orbit and orbital Rashba
+couplings. By considering phase-coherent propagation, we analyse the geometric
+Aharonov-Anandan (AA) phase of the channels which is acquired in a closed path,
+by demonstrating that the orbital polarization can influence the electronic
+transport when amplitude and magnetic field directions are varied. We explore
+all the possible cases for the injection of electrons at various energies in
+the regime of low electron filling. The magnetic field can allow the selection
+of only one channel where the transmission is uniquely affected by the AA
+phase. Conversely, when more orbital channels are involved there is also a
+dynamical contribution that lead to oscillations in the transmission as the
+magnetic field is varied. In particular, the transmission is chiral when the
+energy states are close to the absolute minimum of the energy bands. Instead,
+when an interference between the channels occurs the orbital and spin
+contributions tend to balance each other with the increasing of the magnetic
+field amplitude resulting in a trivial AA phase. This saturation effect does
+not occur in the high magnetic field regime when orbital and spin properties of
+the channels exhibit sharp variations with direct consequences on the
+transport.",1912.05602v1
+2020-01-16,Random singlet state in Ba$_5$CuIr$_3$O$_{12}$ single crystals,"We study the thermodynamic and high-magnetic-field properties of the magnetic
+insulator Ba$_5$CuIr$_3$O$_{12}$, which shows no magnetic order down to 2 K
+consistent with a spin liquid ground state. While the temperature dependence of
+the magnetic susceptibility and the specific heat shows only weak
+antiferromagnetic correlations, we find that the magnetization does not
+saturate up to a field of 59 Tesla, leading to an apparent contradiction. We
+demonstrate that the paradox can be resolved, and all of the experimental data
+can be consistently described within the framework of random singlet states. We
+demonstrate a generic procedure to derive the exchange coupling distribution
+$P(J)$ from the magnetization measurements and use it to show that the
+experimental data is consistent with the power-law form $P(J)\sim J^{-\alpha}$
+with $\alpha \approx 0.6 $. Thus, we reveal that high-magnetic-field
+measurements can be essential to discern quantum spin liquid candidates from
+disorder dominated states that do not exhibit long-range order.",2001.06013v1
+2020-02-06,Temperature scaling of two-ion anisotropy in pure and mixed anisotropy systems,"Magnetic anisotropy plays an essential role in information technology
+applications of magnetic materials, providing a means to retain the long-term
+stability of a magnetic state in the presence of thermal fluctuations.
+Anisotropy consists of a single-ion contribution stemming from the crystal
+structure and two-ion terms attributed to the exchange interactions between
+magnetic atoms. A lack of robust theory crucially limits the understanding of
+the temperature dependence of the anisotropy in pure two-ion and mixed
+single-ion and two-ion systems. Here, we use Green's function theory and
+atomistic Monte Carlo simulations to determine the temperature scaling of the
+effective anisotropy in ferromagnets in these pure and mixed cases, from
+saturated to vanishing magnetization. At low temperature, we find that the pure
+two-ion anisotropy scales with the reduced magnetization as $k(m) \sim
+m^{2.28}$, while the mixed scenario describes the diversity of the temperature
+dependence of the anisotropy observed in real materials. The temperature
+dependence of the mixed anisotropy determined here is expected to considerably
+contribute to the understanding and the control of the thermal properties of
+magnetic materials.",2002.02548v2
+2020-02-25,Strain-Tuned Magnetic Anisotropy in Sputtered Thulium Iron Garnet Ultrathin Films and TIG/Au/TIG Valve Structures,"Defining the magnetic anisotropy for in-plane or out-of-plane easy axis in
+ferrimagnetic insulators films by controlling the strain, while maintaining
+high-quality surfaces, is desirable for spintronic and magnonic applications.
+We investigate ways to tune the anisotropy of amorphous sputtered ultrathin
+thulium iron garnet (TIG) films, and thus tailor their magnetic properties by
+the thickness (7.5 to 60 nm), substrate choice (GGG and SGGG), and
+crystallization process. We correlate morphological and structural properties
+with the magnetic anisotropy of post-growth annealed films. 30 nm thick films
+annealed at 600 {\deg}C show compressive strain favoring an in-plane magnetic
+anisotropy (IPMA), whereas films annealed above 800 {\deg}C are under a tensile
+strain leading to a perpendicular magnetic anisotropy (PMA). Air-annealed films
+present a high degree of crystallinity and magnetization saturation close to
+the bulk value. These results lead to successful fabrication of trilayers
+TIG/Au/TIG, with coupling between the TIG layers depending on Au thickness.
+These results will facilitate the use of TIG to create various in situ clean
+hybrid structures for fundamental interface exchange studies, and towards the
+development of complex devices. Moreover, the sputtering technique is
+advantageous as it can be easily scaled up for industrial applications.",2002.10608v2
+2020-02-28,Traps for pinning and scattering of antiferromagnetic skyrmions via magnetic properties engineering,"Micromagnetic simulations have been performed to investigate the
+controllability of the skyrmion position in antiferromagnetic nanotracks with
+their magnetic properties modified spatially. In this study we have modeled
+magnetic defects as local variations on the material parameters, such as the
+exchange stiffness, saturation magnetization, perpendicular magnetocrystalline
+anisotropy and Dzyaloshinskii-Moriya constant. Thus, we have observed not only
+pinning (potential well) but also scattering (potential barrier) of
+antiferromagnetic skyrmions, when adjusting either a local increase or a local
+reduction for each material parameter. In order to control of the skyrmion
+motion it is very important to impose certain positions along the nanotrack
+where the skyrmion can stop. Magnetic defects incorporated intentionally in
+antiferromagnetic racetracks can be useful for such purpose. In order to
+provide guidelines for experimental studies, we vary both material parameters
+and size of the modified region. The found results show that the efficiency of
+skyrmion trap depends on a suitable combination of magnetic defect parameters.
+Furthermore, we discuss the reason why skyrmions are either attracted or
+repelled by a region magnetically modified.",2003.00907v2
+2020-04-28,Crystal Growth and characterization of possible New Magnetic Topological Insulators FeBi2Te4,"Here we report successful single crystal growth of new possible magnetic
+topological insulator (MTI) FeBi2Te4 by self-flux method via vacuum
+encapsulation process. The detailed Rietveld analysis of Powder XRD data shows
+the as grown MTI crystal to be mainly dominated by FeBi2Te4 phase along with
+minority phases of Bi2Te3 and FeTe. Scanning electron microscope (SEM) image
+shows the morphology of as grown MTI single crystal to be of layered type
+laminar structure. Raman spectroscopy of the crystal exhibited three distinct
+phonon modes at 65, 110, and 132 cm-1 along with two split secondary modes at
+90, and 144cm-1. The secondary split modes are result of FeTe intercalation in
+Bi2Te3 unit cell. Magneto-resistance measurement has been performed at
+different temperatures i.e. 200K, 20K and 2K in applied magnetic fields up to
+12 Tesla, which showed very low MR in comparison to pure Bi2Te3 crystal.
+Temperature dependence of DC magnetization measurements show the FeBi2Te4
+crystal to be mainly of ferromagnetic (FM) or ferri-magnetic nature above 295
+K, albeit a secondary weak magnetic transition is seen at 54-46K as well.
+Detailed isothermal magnetization (MH) results showed that FM saturation moment
+at 295K is 0.00213emu/g, which is nearly invariant till 400 K. Summary, we had
+grown an MTI FeBi2Te4 single crystal, which may be a possible entrant for
+Quantum Anomalous Hall (QAH) effect at room temperature or above.",2004.13584v1
+2020-06-21,"Crystal Structure, Magnetism, and Electronic Properties of New Rare-Earth-Free Ferromagnetic MnPt5As","The design and synthesis of targeted functional materials have been a
+long-term goal for material scientists. Although a universal design strategy is
+difficult to generate for all types of materials, however, it is still helpful
+for a typical family of materials to have such design rules. Herein, we
+incorporated several significant chemical and physical factors regarding
+magnetism, such as structure type, atom distance, spin-orbit coupling, and
+successfully synthesized a new rare-earth-free ferromagnet, MnPt5As, for the
+first time. MnPt5As can be prepared by using high-temperature pellet methods.
+According to X-ray diffraction results, MnPt5As crystallizes in a tetragonal
+unit cell with the space group P4/mmm (Pearson symbol tP7). Magnetic
+measurements on MnPt5As confirm ferromagnetism in this phase with a Curie
+temperature of ~301 K and a saturated moment of 3.5 uB per formula. Evaluation
+by applying the Stoner Criterion also indicates that MnPt5As is susceptible to
+ferromagnetism. Electronic structure calculations using the WIEN2k program with
+local spin density approximation imply that the spontaneous magnetization of
+this phase arises primarily from the hybridization of d orbitals on both Mn and
+Pt atoms. The theoretical assessments are consistent with the experimental
+results. Moreover, the spin-orbit coupling effects heavily influence on
+magnetic moments in MnPt5As. MnPt5As is the first high-performance magnetic
+material in this structure type. The discovery of MnPt5As offers a platform to
+study the interplay between magnetism and structure.",2006.11897v1
+2020-07-22,Study of magnetization relaxation in molecular spin clusters using an innovative kinetic Monte Carlo method,"Modeling blocking temperature in molecular magnets has been a long standing
+problem in the field of molecular magnetism. We investigate this problem using
+a kinetic Monte Carlo (kMC) approach on an assembly of 100,000 short molecular
+magnetic chains (SMMCs), each of six identical spins with nearest neighbour
+anisotropic ferromagnetic exchange interactions. Each spin is also anisotropic
+with an uniaxial anisotropy. The site spin on these SMMCs take values $1$,
+$3/2$ or $2$. Using eigenstates of these SMMCs as the states of Markov chain,
+we carry out a kMC simulation starting with an initial state in which all SMMCs
+are completely spin polarized and assembled on a one-dimensional lattice so as
+to experience ferromagnetic spin-dipolar interaction with each other. From
+these simulations we obtain the relaxation time $\tau_r$ as a function of
+temperature and the associated blocking temperature. We study this for
+different exchange anisotropy, on-site anisotropy and strength of dipolar
+interactions. The magnetization relaxation times show non-Arrhenius behaviour
+for weak on-site interactions. The energy barrier to magnetization relaxation
+increases with increase in on-site anisotropy, exchange anisotropy and strength
+of spin dipolar interactions; more strongly on the last parameter. In all cases
+the barrier saturates at large on-site anisotropy. The barrier also increases
+with site spin. The large barrier observed in rare-earth single ion magnets can
+be attributed to large dipolar interactions due to short intermolecular
+distances, owing to their small size and large spin of the rare earth ion in
+the molecule.",2007.11342v4
+2020-09-29,Magnetic proximity effect on excitonic spin states in Mn-doped layered hybrid perovskites,"Materials combining the optoelectronic functionalities of semiconductors with
+control of the spin degree of freedom are highly sought after for the
+advancement of quantum technology devices. Here, we report the paramagnetic
+Ruddlesden-Popper hybrid perovskite Mn:(PEA)2PbI4 (PEA = phenethylammonium) in
+which the interaction of isolated Mn2+ ions with magnetically brightened
+excitons leads to circularly polarized photoluminescence. Using a combination
+of superconducting quantum interference device (SQUID) magnetometry and
+magneto-optical experiments, we find that the Brillouin-shaped polarization
+curve of the photoluminescence follows the magnetization of the material. This
+indicates coupling between localized manganese magnetic moments and exciton
+spins via a magnetic proximity effect. The saturation polarization of 15% at 4
+K and 6 T indicates a highly imbalanced spin population and demonstrates that
+manganese doping enables efficient control of excitonic spin states in
+Ruddlesden-Popper perovskites. Our finding constitutes the first example of
+polarization control in magnetically doped hybrid perovskites and will
+stimulate research on this highly tuneable material platform that promises
+tailored interactions between magnetic moments and electronic states.",2009.13867v1
+2021-01-28,Modified strong-coupling treatment of a spin-1/2 Heisenberg trimerized chain developed from the exactly solved Ising-Heisenberg diamond chain,"Quantum spin-1/2 antiferromagnetic Heisenberg trimerized chain with strong
+intradimer and weak monomer-dimer coupling constants is studied using the novel
+many-body perturbation expansion, which is developed from the exactly solved
+spin-1/2 Ising-Heisenberg diamond chain preserving correlations between all
+interacting spins of the trimerized chain unlike the standard perturbation
+scheme developed on the grounds of noninteracting spin monomers and dimers. The
+Heisenberg trimerized chain shows the intermediate one-third plateau, which was
+also observed in the magnetization curve of the polymeric compound
+Cu$_3$(P$_2$O$_6$OH)$_2$ affording its experimental realization. Within the
+modified strong-coupling method we have obtained the effective Hamiltonians for
+the magnetic-field range from zero to one-third plateau, and from one-third
+plateau to the saturation magnetization. The second-order perturbation theory
+shows reliable results even for the moderate ratio between weaker dimer-monomer
+and stronger intradimer coupling constants. We have also examined thermodynamic
+properties and recovered the low-temperature peak in the specific heat. The
+accuracy of the developed method is tested through a comparison with numerical
+density-matrix renormalization group and quantum Monte Carlo simulations. Using
+the results for the effective Hamiltonian we suggest straightforward procedure
+for finding the microscopic parameters of one-dimensional trimerized magnetic
+compounds with strong intradimer and weak monomer-dimer couplings. We found the
+refined values for the coupling constants of Cu$_3$(P$_2$O$_6$OH)$_2$ by
+matching the theoretical results with the available experimental data for the
+magnetization and magnetic susceptibility in a wide range of temperatures and
+magnetic fields.",2101.11926v3
+2021-02-19,Effects of Topological Defect on the Energy Spectra and Thermo-magnetic Properties of CO Diatomic Molecule,"Confinement effects of Aharonov-Bohm (AB) flux and magnetic fields with
+topological defect on CO diatomic molecule modeled by screened modified Kratzer
+potential is investigated in this paper. The all-encompassing effects of the
+fields and topological defect result in a strongly repulsive system. We
+discover that the collective effect of the fields and defect is intense than
+the lone and dual effect and consequently there is a substantial shift in the
+bound state energy of the system. We also find that to sustain a low-energy
+medium for the molecule modeled by SMKP, the topological defect and weak AB
+field are required, whereas the Magnetic field can be used as a control
+parameter or enhancer. The effects of the topological defect and magnetic and
+AB fields on the thermal and magnetic properties of the system are duly
+analyzed. We observe that the system tends to exhibit both a paramagnetic and
+diamagnetic behavior for weak and intense magnetic field respectively and some
+sort of saturation at large magnetic field. To further validate our findings,
+we map our result to 3D and a comparison of our results with what obtains in
+literature reveals an excellent agreement.",2102.09842v1
+2021-06-07,Crust-core transition of a neutron star: effect of the temperature under strong magnetic fields,"The effect of temperature on the crust-core transition of a magnetar is
+studied. The thermodynamical spinodals are used to calculate the transition
+region within a relativistic mean-field approach for the equation of state.
+Magnetic fields with intensities $5\times 10^{16}$ G and $5\times 10 ^{17}$ G
+are considered. It is shown that the effect on the extension of the crust-core
+transition is washed away for temperatures above $10^{9}$ K for magnetic field
+intensities $ \lesssim 5\times 10^{16}$ G but may still persist if a magnetic
+field as high as $5\times 10 ^{17}$G is considered. For temperatures below that
+value, the effect of the magnetic field on crust-core transition is noticeable
+and grows as the temperature decreases and, in particular, it is interesting to
+identify the existence of disconnected non-homogeneous matter above the $B=0$
+crust core transition density. Models with different symmetry energy slopes at
+saturation show quite different behaviors. In particular, a model with a large
+slope, as suggested by the recent results of PREX-2, predicts the existence of
+up to four disconnected regions of non-homogeneous matter above the zero
+magnetic field crust-core transition density.",2106.03590v2
+2021-08-26,Helical turbulent nonlinear dynamo at large magnetic Reynolds numbers,"The excitation and further sustenance of large-scale magnetic fields in
+rotating astrophysical systems, including planets, stars and galaxies, is
+generally thought to involve a fluid magnetic dynamo effect driven by helical
+magnetohydrodynamic turbulence. While this scenario is appealing on general
+grounds, it however currently remains largely unconstrained, notably because a
+fundamental understanding of the nonlinear asymptotic behaviour of large-scale
+fluid magnetism in the astrophysically-relevant but treacherous regime of large
+magnetic Reynolds number $Rm$ is still lacking. We explore this problem using
+local high-resolution simulations of turbulent magnetohydrodynamics driven by
+an inhomogeneous helical forcing generating a sinusoidal profile of kinetic
+helicity, mimicking the hemispheric distribution of kinetic helicity in
+rotating turbulent fluid bodies. We identify a transition at large $Rm$ to a
+nonlinear state, followed up to $Rm\simeq 3\times 10^3$, consisting of strong,
+saturated small-scale magnetohydrodynamic turbulence and a weaker, travelling
+coherent large-scale field oscillation. This state is characterized by an
+asymptotically small resistive dissipation of magnetic helicity, by its spatial
+redistribution across the equator through turbulent fluxes driven by the
+hemispheric distribution of kinetic helicity, and by the tentative presence in
+the tangled dynamical magnetic field of plasmoids typical of reconnection at
+large $Rm$.",2108.12037v2
+2021-09-10,Electrical spectroscopy of the spin-wave dispersion and bistability in gallium-doped yttrium iron garnet,"Yttrium iron garnet (YIG) is a magnetic insulator with record-low damping,
+allowing spin-wave transport over macroscopic distances. Doping YIG with
+gallium ions greatly reduces the demagnetizing field and introduces a
+perpendicular magnetic anisotropy, which leads to an isotropic spin-wave
+dispersion that facilitates spin-wave optics and spin-wave steering. Here, we
+characterize the dispersion of a gallium-doped YIG (Ga:YIG) thin film using
+electrical spectroscopy. We determine the magnetic anisotropy parameters from
+the ferromagnetic resonance frequency and use propagating spin wave
+spectroscopy in the Damon-Eshbach configuration to detect the small spin-wave
+magnetic fields of this ultrathin weak magnet over a wide range of wavevectors,
+enabling the extraction of the exchange constant $\alpha=1.3(2)\times10^{-12}$
+J/m. The frequencies of the spin waves shift with increasing drive power, which
+eventually leads to the foldover of the spin-wave modes. Our results shed light
+on isotropic spin-wave transport in Ga:YIG and highlight the potential of
+electrical spectroscopy to map out the dispersion and bistability of
+propagating spin waves in magnets with a low saturation magnetization.",2109.05045v1
+2022-02-19,Control and tunability of magnetic bubble states in multilayers with strong perpendicular magnetic anisotropy at ambient conditions,"The reversal of magnetic bubble helicity through topologically trivial
+transient states provides an additional degree of freedom that promises the
+development of multidimensional magnetic memories. A key requirement for this
+concept is the stabilization of bubble states at ambient conditions on
+application-compatible substrates. In the present work we demonstrate a
+stabilization routine for remanent bubble states in high perpendicular magnetic
+anisotropy [(Co(0.44\,nm)/Pt(0.7\,nm)]$_X$, X = 48, 100, 150 multilayers on
+Si/SiO$_2$ substrates by exploring the effect of external magnetic fields
+($H_\mathrm{m}$) of different strength and angles ($\theta$) with respect to
+the film surface normal. By systematic variation of these two parameters, we
+demonstrate that remanent bubble density and mean bubble diameter can be
+carefully tuned and optimized for each sample. Our protocol based on
+magnetometry only reveals the densest remanent bubble states at $H_\mathrm{m} =
+0.87 H_\mathrm{s}$ ($H_\mathrm{s}$ is the magnetic saturation field) and
+$\theta=60^\circ - 75^\circ$ for all $X$ with a maximum of 3736 domains/100
+$\mu$m$^2$ for the X = 48 sample. The experimental observations are supported
+by micromagnetic simulations taking into account the nanoscale lateral grain
+structure of multilayers synthesized by magnetron sputter deposition, and thus
+helping understand the different density of the bubble states found in these
+systems.",2202.09564v1
+2022-06-15,Deformed spin-$\frac12$ square lattice in antiferromagnetic NaZnVOPO$_4$(HPO$_4$),"We report the structural and magnetic properties of a new spin-$\frac12$
+antiferromagnet NaZnVOPO$_4$(HPO$_4$) studied via x-ray diffraction, magnetic
+susceptibility, high-field magnetization, specific heat, and $^{31}$P nuclear
+magnetic resonance (NMR) measurements, as well as density-functional
+band-structure calculations. While thermodynamic properties of this compound
+are well described by the $J_1-J_2$ square-lattice model, \textit{ab initio}
+calculations suggest a significant deformation of the spin lattice. From fits
+to the magnetic susceptibility we determine the averaged nearest-neighbor and
+second-neighbor exchange couplings of $\bar J_1\simeq -1.3$ K and $\bar
+J_2\simeq 5.6$ K, respectively. Experimental saturation field of 15.3\,T is
+consistent with these estimates if 20\% spatial anisotropy in $J_1$ is taken
+into account. Specific heat data signal the onset of a magnetic long-range
+order at $T_{\rm N} \simeq 2.1$ K, which is further supported by a sharp peak
+in the NMR spin-lattice relaxation rate. The NMR spectra mark the superposition
+of two P lines due to two noneqivalent P sites where the broad line with the
+strong hyperfine coupling and short $T_1$ is identified as the P(1) site
+located within the magnetic planes, while the narrow line with the weak
+hyperfine coupling and long $T_1$ is designated as the P(2) site located
+between the planes.",2206.07299v1
+2022-06-29,Inertial active Ornstein-Uhlenbeck particle in the presence of magnetic field,"We consider an inertial active Ornstein-Uhlenbeck particle in an athermal
+bath. The particle is charged, constrained to move in a two-dimensional
+harmonic trap, and a magnetic field is applied perpendicular to the plane of
+motion. The steady state correlations and the mean square displacement are
+studied when the particle is confined as well as when it is set free from the
+trap. With the help of both numerical simulation and analytical calculations,
+we observe that inertia plays a crucial role in the dynamics in the presence of
+a magnetic field. In a highly viscous medium where the inertial effects are
+negligible, the magnetic field has no influence on the correlated behaviour of
+position as well as velocity. In the time asymptotic limit, the overall
+displacement of the confined harmonic particle gets enhanced by the presence of
+magnetic field and saturates for a stronger magnetic field. On the other hand,
+when the particle is set free, the overall displacement gets suppressed and
+approaches zero when strength of the field is very high. Interestingly, it is
+seen that in the time asymptotic limit, the confined harmonic particle behaves
+like a passive particle and becomes independent of the activity, especially in
+the presence of a very strong magnetic field. Similarly, for a free particle
+the mean square displacement in the long time limit becomes independent of
+activity even for a longer persistence of noise correlation in the dynamics.",2206.14715v1
+2022-10-12,Current-induced switching of thin film $α$-Fe$_2$O$_3$ devices imaged using a scanning single-spin microscope,"Electrical switching of N\'eel order in an antiferromagnetic insulator is
+desirable as a basis for memory applications. Unlike electrically-driven
+switching of ferromagnetic order via spin-orbit torques, electrical switching
+of antiferromagnetic order remains poorly understood. Here we investigate the
+low-field magnetic properties of 30 nm thick, c-axis oriented
+$\alpha$-Fe$_2$O$_3$ Hall devices using a diamond nitrogen-vacancy (NV) center
+scanning microscope. Using the canted moment of $\alpha$-Fe$_2$O$_3$ as a
+magnetic handle on its N\'eel vector, we apply a saturating in-plane magnetic
+field to create a known initial state before letting the state relax in low
+field for magnetic imaging. We repeat this procedure for different in-plane
+orientations of the initialization field. We find that the magnetic field
+images are characterized by stronger magnetic textures for fields along
+$[\bar{1}\bar{1}20]$ and $[11\bar{2}0]$, suggesting that despite the expected
+3-fold magneto-crystalline anisotropy, our $\alpha$-Fe$_2$O$_3$ thin films have
+an overall in-plane uniaxial anisotropy. We also study current-induced
+switching of the magnetic order in $\alpha$-Fe$_2$O$_3$. We find that the
+fraction of the device that switches depends on the current pulse duration,
+amplitude and direction relative to the initialization field. Specifically, we
+find that switching is most efficient when current is applied along the
+direction of the initialization field.",2210.06233v1
+2022-10-14,Flux eruption events drive angular momentum transport in magnetically arrested accretion flows,"We evolve two high-resolution general relativistic magnetohydrodynamic
+(GRMHD) simulations of advection-dominated accretion flows around non-spinning
+black holes (BHs), each over a duration $\sim 3\times 10^5\,GM_{\rm BH}/c^3$.
+One model captures the evolution of a weakly magnetized (SANE) disk and the
+other a magnetically arrested disk (MAD). Magnetic flux eruptions in the MAD
+model push out gas from the disk and launch strong winds with outflow
+efficiencies at times reaching $10\%$ of the incoming accretion power. Despite
+the substantial power in these winds, average mass outflow rates remain small
+out to a radius $\sim100\,GM_{\rm BH}/c^2$, only reaching $\sim 60-80\%$ of the
+horizon accretion rate. The average outward angular momentum transport is
+primarily radial in both modes of accretion, but with a clear distinction:
+magnetic flux eruption-driven disk winds cause a strong vertical flow of
+angular momentum in the MAD model, while for the SANE model, the
+magnetorotational instability (MRI) moves angular momentum mostly equatorially
+through the disk. Further, we find that the MAD state is highly transitory and
+non-axisymmetric, with the accretion mode often changing to a SANE-like state
+following an eruption before reattaining magnetic flux saturation with time.
+The Reynolds stress changes direction during such transitions, with the MAD
+(SANE) state showing an inward (outward) stress, possibly pointing to
+intermittent MRI-driven accretion in MADs. Pinning down the nature of flux
+eruptions using next-generation telescopes will be crucial in understanding the
+flow of mass, magnetic flux and angular momentum in sub-Eddington accreting BHs
+like M87$^*$ and Sagittarius A$^*$.",2210.08045v1
+2022-11-07,Galactic Dynamos,"Spiral galaxies, including the Milky Way, have large-scale magnetic fields
+with significant energy densities. The dominant theory attributes these
+magnetic fields to a large-scale dynamo. We review the current status of dynamo
+theory and discuss various numerical simulations designed to explain either
+particular aspects of the problem or to reproduce galactic magnetic fields
+globally. Our main conclusions can be summarized as follows. Idealized direct
+numerical simulations produce mean magnetic fields, whose saturation energy
+density tends to decline with increasing magnetic Reynolds number. This is
+still an unsolved problem. Large-scale galactic magnetic fields of microgauss
+strengths can probably only be explained if helical magnetic fields of small or
+moderate length scales can rapidly be ejected or destroyed. Small-scale dynamos
+are important throughout a galaxy's life, and probably provide strong seed
+fields at early stages. The circumgalactic medium (CGM) may play an important
+role in driving dynamo action at small and large length scales. These
+interactions between the galactic disk and the CGM may provide important
+insights into our understanding of galactic dynamos. We expect future research
+in galactic dynamos to focus on the cosmological history of galaxies and the
+interaction with the CGM as means of replacing the idealized boundary
+conditions used in earlier work.",2211.03476v2
+2023-02-06,Large ordered moment with strong easy-plane anisotropy and vortex-domain pattern in the kagome ferromagnet Fe$_3$Sn,"We report the structural and magnetic properties of high-quality bulk single
+crystals of the kagome ferromagnet Fe$_3$Sn. The dependence of magnetisation on
+the magnitude and orientation of the external field reveals strong easy-plane
+type uniaxial magnetic anisotropy, which shows a monotonous increase from
+$K_1=-0.99\times 10^6 J/m^3$ at 300\,K to $-1.23\times10^6 J/m^3$ at 2\,K. Our
+\textit{ab initio} electronic structure calculations yield the value of total
+magnetic moment of about 6.9 $\mu_B$/f.u. and a magnetocrystalline anisotropy
+energy density of 0.406\,meV/f.u. ($1.16\times10^6 J/m^3$) both being in good
+agreement with the experimental values. The self-consistent DFT computations
+for the components of the spin/orbital moments indicate that the small
+difference between the saturation magnetisations measured along and
+perpendicular to the kagome layers results from the subtle balance between the
+Fe and Sn spin/orbital moments on the different sites. In zero field, magnetic
+force microscopy reveals micrometer-scale magnetic vortices with weakly pinned
+cores that vanish at $\sim$3\,T applied perpendicular to the kagome plane. Our
+micromagnetic simulations, using the experimentally determined value of
+anisotropy, well reproduce the observed vortex-domain structure. The present
+study, in comparison with the easy-axis ferromagnet Fe$_3$Sn$_2$, shows that
+varying the stacking of kagome layers provides an efficient control over
+magnetic anisotropy in this family of Fe-based kagome magnets.",2302.13810v1
+2023-03-07,Effects of Magnetic Fields on Gas Dynamics and Star Formation in Nuclear Rings,"Nuclear rings at the centers of barred galaxies are known to be strongly
+magnetized. To explore the effects of magnetic fields on star formation in
+these rings and nuclear gas flows, we run magnetohydrodynamic simulations in
+which there is a temporally-constant magnetized inflow to the ring,
+representing a bar-driven inflow. The mass inflow rate is
+$1\,M_\odot\,\mathrm{yr}^{-1}$, and we explore models with a range of field
+strength in the inflow. We adopt the TIGRESS framework developed by Kim &
+Ostriker to handle radiative heating and cooling, star formation, and resulting
+supernova (SN) feedback. We find that magnetic fields are efficiently amplified
+in the ring due to rotational shear and SN feedback. Within a few
+$100\,\mathrm{Myr}$, the turbulent component $B_\mathrm{trb}$ in the ring
+saturates at $\sim 35\,\mu\mathrm{G}$ (in rough equipartition with the
+turbulent kinetic energy density), while the regular component $B_\mathrm{reg}$
+exceeds $50\,\mu\mathrm{G}$. Expanding superbubbles created by clustered SN
+explosions vertically drag predominantly-toroidal fields from near the midplane
+to produce poloidal fields in high-altitude regions. The growth of magnetic
+fields greatly suppresses star formation at late times. Simultaneously, strong
+magnetic tension in the ring drives radially inward accretion flows from the
+ring to form a circumnuclear disk in the central region; this feature is absent
+in the unmagnetized model.",2303.04206v1
+2023-08-10,Budget equations and astrophysical nonlinear mean-field dynamos,"Solar, stellar and galactic large-scale magnetic fields are originated due to
+a combined action of non-uniform (differential) rotation and helical motions of
+plasma via mean-field dynamos. Usually, nonlinear mean-field dynamo theories
+take into account algebraic and dynamic quenching of alpha effect and algebraic
+quenching of turbulent magnetic diffusivity. However, the theories of the
+algebraic quenching do not take into account the effect of modification of the
+source of turbulence by the growing large-scale magnetic field. This phenomenon
+is due to the dissipation of the strong large-scale magnetic field resulting in
+an increase of the total turbulent energy. This effect has been studied using
+the budget equation for the total turbulent energy (which takes into account
+the feedback of the generated large-scale magnetic field on the background
+turbulence) for (i) a forced turbulence, (ii) a shear-produced turbulence and
+(iii) a convective turbulence. As the result of this effect, a nonlinear dynamo
+number decreases with increase of the large-scale magnetic field, so that that
+the mean-field $\alpha\Omega$, $\alpha^2$ and $\alpha^2\Omega$ dynamo
+instabilities are always saturated by the strong large-scale magnetic field.",2308.05590v3
+2023-09-11,Dynamics of photospheric magnetic flux distribution and variations in solar RVs -- a study using HARPS-N solar and SDO observations,"The distribution and evolution of photospheric magnetic field in sunspots,
+plages and network, and variations in their relative flux content, play key
+roles in radial velocity (RV) fluctuations observed in Sun-as-a-star spectra.
+Differentiating and disentangling such magnetic contributions to RVs help in
+building models to account for stellar activity signals in high precision RV
+exoplanet searches. In this work, as earlier authors, we employ high-resolution
+images of the solar magnetic field and continuum intensities from SDO/HMI to
+understand the activity contributions to RVs from HARPS-N solar observations.
+Using well observed physical relationships between strengths and fluxes of
+photospheric magnetic fields, we show that the strong fields (spots, plages and
+network) and the weak internetwork fields leave distinguishing features in
+their contributions to the RV variability. We also find that the fill-factors
+and average unsigned magnetic fluxes of different features correlate
+differently with the RVs and hence warrant care in employing either of them as
+a proxy for RV variations. In addition, we examine disk averaged UV intensities
+at 1600 \r{A} and 1700 \r{A} wavelength bands imaged by SDO/AIA and their
+performances as proxies for variations in different magnetic features. We find
+that the UV intensities provide a better measure of contributions of plage
+fields to RVs than the Ca II H-K emission indices, especially during high
+activity levels when the latter tend to saturate.",2309.05428v1
+2023-10-03,Complex magnetic interactions and critical behavior analysis in quaternary CoFeV$_{0.8}$Mn$_{0.2}$Si Heusler alloy,"We investigate the magnetic behavior and critical exponents of quaternary
+CoFeV$_{0.8}$Mn$_{0.2}$Si Heusler alloy to understand the interactions across
+the Curie temperature ($T_{\rm C}$). The Rietveld refinement of the x-ray
+diffraction pattern with the space group F$\bar{4}$3m confirms a single-phase
+cubic Y-type crystal structure. The magnetic susceptibility $\chi (T)$ data
+show a ferromagnetic nature with a second-order phase transition from
+paramagnetic to ferromagnetic at $446\pm1$~K. The saturation magnetization at
+5~K is determined to be 2.2~$\mu_B$/f.u., which found to be close to the
+Slater--Pauling rule and indicates its half-metallic nature. The values of
+asymptotic critical exponents ($\beta$, $\gamma$, and $\delta$) and the $T_{\rm
+C}$ are extracted through detailed analytical analysis including the Modified
+Arrott plot, the Kouvel-Fisher (K--F) method, and the Widom scaling relation.
+Interestingly, the estimated values of $\beta$ = 0.369 and $\gamma$ = 1.445
+closely approximate the theoretical values of the 3D Heisenberg model and
+second-order thermodynamic phase transition across the $T_{\rm C}$. The
+obtained exponents lead to the collapse of renormalized isotherms, represented
+by the relationship between the magnetization (m) and the applied magnetic
+field (h), into two distinct branches above and below the $T_{\rm C}$, which
+validates the reliability of the analysis. Furthermore, these exponents suggest
+that the spin interaction follows a decay pattern of $J(r) \sim r^{-4.99}$,
+indicating a short-range magnetic ordering, akin to the itinerant-electron 3D
+Heisenberg model.",2310.01790v1
+2024-01-08,Computational approaches to modeling dynamos in galaxies,"Galaxies are observed to host magnetic fields with a typical total strength
+of around 15microgauss. A coherent large-scale field constitutes up to a few
+microgauss of the total, while the rest is built from strong magnetic
+fluctuations over a wide range of spatial scales. This represents sufficient
+magnetic energy for it to be dynamically significant. Several questions
+immediately arise: What is the physical mechanism that gives rise to such
+magnetic fields? How do these magnetic fields affect the formation and
+evolution of galaxies? In which physical processes do magnetic fields play a
+role, and how can that role be characterized? Numerical modelling of magnetized
+flows in galaxies is playing an ever-increasing role in finding those answers.
+We review major techniques used for these models. Current results strongly
+support the conclusion that field growth occurs during the formation of the
+first galaxies on timescales shorter than their accretion timescales due to
+small-scale turbulent dynamos. The saturated small-scale dynamo maintains field
+strengths at a few percent of equipartition with turbulence. The subsequent
+action of large-scale dynamos in differentially rotating discs produces
+observed modern field strengths in equipartition with the turbulence and having
+power at large scales. The field structure resulting appears consistent with
+observations including Faraday rotation and polarisation from synchrotron and
+dust thermal emission. Major remaining challenges include scaling numerical
+models toward realistic scale separations and Prandtl and Reynolds numbers.",2401.04015v1
+2024-04-02,Isotropic to nematic transition in alcohol ferrofluids of barium hexaferrite nanoplatelets,"Alcohol ferrofluids made of ferrimagnetic barium hexaferrite (BHF)
+nanoplatelets (NPLs) form a unique example of a dipolar fluid - a liquid
+magnet. Its formation is induced at a high enough concentration of the NPLs.
+The key interactions between the NPLs are long-ranged dipolar magnetic and
+screened anisotropic electrostatic. Herein, we report the results on tuning the
+isotropic-nematic phase transition (i.e., the NPLs threshold concentration) in
+1-butanol ferrofluids of BHF NPLs by affecting the interactions in the
+ferrofluids. The threshold concentration was determined by polarizing optical
+microscopy (POM) combined with a system for magnetic field manipulation and was
+in the range between 4.6 and 6.6 \% (v/v) depending on the ferrofluid. We
+observed that the threshold concentration decreased for 0.6 \% (v/v) with a
+larger mean diameter of the NPLs, up to 0.6 \% (v/v) with increased ionic
+strength of the ferrofluid, and for $\sim$ 2 \% (v/v) with higher saturation
+magnetization of the NPLs. We showed that by tuning the parameters affecting
+the ferrofluid's interplatelet interactions, we can alter the threshold
+concentration for the liquid magnet formation. The results elucidate the
+importance of a delicate balance between the repulsive screened electrostatic
+and attractive dipolar magnetic interactions for the liquid magnet formation.",2404.01956v1
+1995-10-06,An Incoherent $α-Ω$ Dynamo in Accretion Disks,"We use the mean-field dynamo equations to show that an incoherent alpha
+effect in mirror-symmetric turbulence in a shearing flow can generate a large
+scale, coherent magnetic field. We illustrate this effect with simulations of a
+few simple systems. In accretion disks, this process can lead to axisymmetric
+magnetic domains whose radial and vertical dimensions will be comparable to the
+disk height. This process may be responsible for observations of dynamo
+activity seen in simulations of dynamo-generated turbulence involving, for
+example, the Balbus-Hawley instability. In this case the magnetic field
+strength will saturate at $\sim (h/r)^2$ times the ambient pressure in real
+accretion disks. The resultant dimensionless viscosity will be of the same
+order. In numerical simulations the azimuthal extent of the simulated annulus
+should be substituted for $r$. We compare the predictions of this model to
+numerical simulations previously reported by Brandenburg et al. (1995). In a
+radiation pressure dominated environment this estimate for viscosity should be
+reduced by a factor of $(P_{gas}/P_{radiation})^6$ due to magnetic buoyancy.",9510038v1
+2000-01-24,The Magnetic Fields of the Universe and Their Origin,"Recent rotation measure observations of a dozen or so galaxy clusters have
+revealed a surprisingly large amount of magnetic fields, whose estimated energy
+and flux are, on average, $\sim 10^{58}$ ergs and $\sim 10^{41}$ G cm$^2$,
+respectively. These quantities are so much larger than any coherent sums of
+individual galaxies within the cluster that an efficient galactic dynamo is
+required. We associate these fields with single AGNs within the cluster and
+therefore with all galaxies during their AGN phase. Only the central, massive
+black hole (BH) has the necessary binding energy, $\sim 10^{61}$ ergs. Only the
+accretion disk during the BH formation has the winding number, $\sim 10^{11}$
+turns, necessary to make the gain and magnetic flux. We present a model of the
+BH accretion disk dynamo that might create these magnetic fields, where the
+helicity of the $\alpha - \Omega$ dynamo is driven by star-disk collisions. The
+back reaction of the saturated dynamo forms a force-free field helix that
+carries the energy and flux of the dynamo and redistributes them within the
+clusters.",0001418v1
+2002-08-09,Circular Polarization of Water Masers in the Circumstellar Envelopes of Late Type Stars,"We present circular polarization measurements of circumstellar H_2O masers.
+The circular polarization detected in the (6_{16}-5_{23}) rotational transition
+of the H_{2}O maser can be attributed to Zeeman splitting in the intermediate
+temperature and density regime. The magnetic fields are derived using a
+general, LTE Zeeman analysis as well as a full radiative transfer method
+(non-LTE), which includes a treatment of all hyperfine components
+simultaneously as well as the effects of saturation and unequal populations of
+the magnetic substates. The differences and relevances of these interpretations
+are discussed extensively. The field strengths are compared with previous
+detections of the magnetic field on the SiO and OH masers. We show that the
+magnetic pressure dominates the thermal pressure by a factor of 20 or more.",0208197v1
+2004-05-04,Astrophysical magnetic fields and nonlinear dynamo theory,"The current understanding of astrophysical magnetic fields is reviewed,
+focusing on their generation and maintenance by turbulence. In the
+astrophysical context this generation is usually explained by a self-excited
+dynamo, which involves flows that can amplify a weak 'seed' magnetic field
+exponentially fast. Particular emphasis is placed on the nonlinear saturation
+of the dynamo. Analytic and numerical results are discussed both for small
+scale dynamos, which are completely isotropic, and for large scale dynamos,
+where some form of parity breaking is crucial. Central to the discussion of
+large scale dynamos is the so-called alpha effect which explains the generation
+of a mean field if the turbulence lacks mirror symmetry, i.e. if the flow has
+kinetic helicity. Large scale dynamos produce small scale helical fields as a
+waste product that quench the large scale dynamo and hence the alpha effect.
+With this in mind, the microscopic theory of the alpha effect is revisited in
+full detail and recent results for the loss of helical magnetic fields are
+reviewed.",0405052v2
+2006-10-30,Green Bank Telescope observations of the water masers of NGC 3079: accretion disk magnetic field and maser scintillation,"We present observations of the 22 GHz water megamasers in the circumnuclear
+disk of NGC 3079 obtained with the Green Bank Telescope. The data are analyzed
+for circular polarization due to the Zeeman-induced splitting of the water
+maser lines. No circular polarization is detected and we derive a 1 sigma upper
+limit of 11 mG for the toroidal magnetic field at ~0.64 pc from the central
+black hole. This is the tightest upper limit for the magnetic field around a
+black hole to date. We use the magnetic field limit to derive an estimate of
+the mass accretion onto the central black hole. In addition to the polarimetric
+results, we present an observation of rapid variability in the maser lines,
+which we explain as weak interstellar scintillation. From the scintillation
+parameters, we estimate an intrinsic size of the mostly saturated maser
+features of ~12 microarcseconds. This is consistent with models assuming a
+thick, clumpy accretion disk.",0610912v1
+1998-05-04,Phase diagram of the anti-ferromagnetic xxz model in the presence of an external magnetic field,"The anisotropic s=1/2 anti-ferromagnetic Heisenberg chain in the presence of
+an external magnetic field is studied by using the standard quantum
+renormalization group. We obtain the critical line of the transition from
+partially magnetized (PM) phase to the saturated ferromagnetic (SFM) phase. The
+crossover exponent between the PM phase and anti-ferromagnetic Ising (AFI)
+phase is evaluated. Our results show that the anisotropy($\d$) term is relevant
+and causes crossover. These results indicate that the standard RG approach
+yields fairly good values for the critical points and their exponents. The
+magnetization curve, correlation functions and the ground state energy per site
+are obtained and compared with the known exact results.",9805024v2
+1998-12-30,Giant transverse magnetoresistance in an asymmetric system of three GaAs/AlGaAs quantum wells in a strong magnetic field at room temperature,"The giant transverse magnetoresistance is observed in the case of
+photoinduced nonequilibrium carriers in an asymmetric undoped system of three
+GaAs/AlGaAs quantum wells at room temperature. In a magnetic field of 75 kOe,
+the resistance of nanostructure being studied increases by a factor of 1.85.
+The magnetoresistance depends quadratically on the magnetic field in low fields
+and tends to saturation in high fields. This phenomenon is attributed to the
+rearrangement of the electron wave function in magnetic field. Using the fact
+that the incoherent part of the scattering probability for electron scattering
+on impurities and bulk defects is proportional to the integral of the forth
+power of the envelope wave function, the calculated field dependence of the
+magnetoresistance is shown to be similar to that observed experimentally.",9812426v1
+1999-08-02,Breakdown of the magnetization plateau of the S=1/2 ferromagnetic-ferromagnetic-antiferromagnetic trimerized spin chain with anisotropy,"We study the breakdown of the magnetization plateau at the magnetization
+M=M_{S}/3 (M_{S} is the saturation magnetization) of the S=1/2 anisotropic spin
+chain with ferromagnetic-ferromagnetic-antiferromagnetic interactions. We
+consider the model with the isotropic ferromagnetic (trimer) coupling J_{F},
+and anisotropic antiferromagnetic coupling (J_{x}=J_{y}=J_{AF} and J_{z}=\Delta
+J_{AF}). For the limit of large \gamma\equiv J_{F}/J_{AF}, the model is
+equivalent to the S=3/2 XXZ chain with the exchange anisotropy \Delta. There is
+a phase transition between the plateau (small-\gamma) and the no-plateau
+(large-\gamma) regions. This phase transition is of the
+Berezinskii-Kosterlitz-Thouless type, and we determine the phase boundary from
+the numerical diagonalization data. For \Delta=1, in particular, the phase
+transition between the plateau and the no-plateau regions occurs at the point
+\gamma_{c}=15.4.",9908027v2
+1999-08-03,Spin Chains in an External Magnetic Field. Closure of the Haldane Gap and Effective Field Theories,"We investigate both numerically and analytically the behaviour of a spin-1
+antiferromagnetic (AFM) isotropic Heisenberg chain in an external magnetic
+field. Extensive DMRG studies of chains up to N=80 sites extend previous
+analyses and exhibit the well known phenomenon of the closure of the Haldane
+gap at a lower critical field H_c1. We obtain an estimate of the gap below
+H_c1. Above the lower critical field, when the correlation functions exhibit
+algebraic decay, we obtain the critical exponent as a function of the net
+magnetization as well as the magnetization curve up to the saturation (upper
+critical) field H_c2. We argue that, despite the fact that the SO(3) symmetry
+of the model is explicitly broken by the field, the Haldane phase of the model
+is still well described by an SO(3) nonlinear sigma-model. A mean-field theory
+is developed for the latter and its predictions are compared with those of the
+numerical analysis and with the existing literature.",9908044v1
+2000-04-13,NMR and Neutron Scattering Studies of Quasi One-Dimensional Magnet CuV_2O_6,"Magnetic properties of a quasi one-dimensional magnet CuV_2O_6 have been
+studied by means of susceptibility measurement, NMR and powder neutron
+diffraction. Cu^{2+} spins (S=1/2) order antiferromagnetically below 22.6 K,
+and the saturation moment is about 0.70 \mu_{B} at 0 K. The magnetic structure
+determined in the present study indicates that in CuV_2O_6 one-dimensional
+antiferromagnetic spin chains are along [110], suggesting a dominant
+antiferromagnetic exchange interaction between the next-nearest-neighbor spins
+rather than the nearest-neighbor ones.",0004213v2
+2001-03-19,Time decay of the remanent magnetization in the $\pm J$ spin glass model at T=0,"Using the zero-temperature Metropolis dynamics, the time decay of the
+remanent magnetization in the $\pm J$ Edward-Anderson spin glass model with a
+uniform random distribution of ferromagnetic and antiferromagnetic interactions
+has been investigated. Starting from the saturation, the magnetization per spin
+$m$ reveals a slow decrease with time, which can be approximated by a power
+law:$m(t)=m_{\infty}+ ({t\over a_{0}})^{a_{1}}$, $a_{1} < 0$. Moreover, its
+relaxation does not lead it into one of the ground states, and therefore the
+system is trapped in metastable isoenergetic microstates remaining magnetized.
+Such behaviour is discussed in terms of a random walk the system performs on
+its available configuration space.",0103382v4
+2001-07-03,"Sr$_3$CuIrO$_6$, a spin-chain compound with random ferromagnetic-antiferromagnetic interactions","Ac and dc magnetization and heat-capacity (C) measurements performed on the
+pseudo-one-dimensional compound Sr$_3$CuIrO$_6$ reveal a competition between
+antiferromagnetic (AF) and ferromagnetic (F) exchange couplings, as evidenced
+by frequency dependence of ac susceptibility and by the absence of a C anomaly
+at the magnetic transition. The value of the saturation moment (about 0.35
+$\mu_B$/formula unit) is much smaller than expected for ferromagnetism from the
+two S=1/2 ions (Cu and Ir). Thus, this compound is not a ferromagnet in zero
+magnetic field, in contrast to earlier beliefs. Of particular importance is the
+finding that the value of the magnetic ordering temperature is sample
+dependent, sensitive to synthetic conditions resulting from deviations in
+oxygen/Cu content. We propose that this compound serves as a unique model
+system to test theories on random AF-F interaction in a chain system,
+considering that this competition can be tuned without any chemical
+substitution.",0107069v1
+2001-11-08,Magnetic structures of RbCuCl_3 in a transverse field,"A recent high-field magnetization experiment found a phase transition of
+unknown character in the layered, frustrated antiferromagnet RbCuCl_3, in a
+transverse field (in the layers). Motivated by these results, we have examined
+the magnetic structures predicted by a model of RbCuCl_3, using the classical
+approximation. At small fields, we obtain the structure already known to be
+optimal, an incommensurate (IC) spiral with wave vector q in the layers. At
+higher fields, we find a staircase of long-period commensurate (C) phases
+(separated initially by the low-field IC phase), then two narrow IC phases,
+then a fourth IC phase (also with intermediate C phases), and finally the
+ferromagnetically aligned phase at the saturation field H_S. The
+three-sublattice C states familiar from the theory of the triangular
+antiferromagnet are never optimal. The C phases and the two intermediate IC
+phases were previously unknown in this context. The magnetization is
+discontinuous at a field \approx 0.4H_S, in qualitative agreement with
+experiment, though we find much fine structure not reported.",0111146v1
+2002-04-17,Quantum magnetization plateaux of an anisotropic ferrimagnetic spin chain,"The magnetization curve of the $(S,s)=(1,1/2)$ ferrimagnetic alternating spin
+chain with the single-ion anisotropy $D$ is investigated with the numerical
+exact diagonalization of finite clusters and size-scaling analyses. The system
+has a plateau at 1/3 of the saturation moment, which corresponds to the
+spontaneous magnetization for D=0. Varying $D$ in the 1/3-magnetized ground
+state under the external field along the axis of $D$, a quantum phase
+transition is revealed to occur at the critical value $D/J=1.114 \pm 0.001$
+where the plateau vanishes. Except for the critical point, the plateau is
+always opening, but the mechanism is different between $D<D_c$ and $D>D_c$. The
+change of mechanisms is an evidence to clarify that the plateau originates from
+the quantization of magnetization.",0204375v2
+2002-07-15,Low temperature annealing studies of Ga1-xMnxAs,"High- and low-field magneto-transport measurements, as well as SQUID
+measurements of magnetization, were carried out on Ga1-xMnxAs epilayers grown
+by low temperature molecular beam epitaxy, and subsequently annealed under
+various conditions. We observe a large enhancement of ferromagnetism when the
+samples are annealed at an optimal temperature, typically about 280 0C. Such
+optimal annealing leads to an increase of Curie temperature, accompanied by an
+increase of both the conductivity and the saturation magnetization. A decrease
+of the coercive field and of magnetoresistivity is also observed for Ga1-xMnxAs
+annealed at optimal conditions. We suggest that the experimental results
+reported in this paper are related to changes in the domain structure of
+Ga1-xMnxAs.",0207354v1
+2002-11-18,"Synthesis of RuSr2(Ln3/4Ce1/4)2Cu2O10 magneto-superconducting compounds with Ln = Ho, Y and Dy by high-pressure high-temperature (HPHT) technique","The samples of composition RuSr2(Ln3/4Ce1/4)2Cu2O10 with Ln = Ho, Y and Dy.
+being synthesized by high pressure high temperature (6Gpa, 1200 0C) solid state
+synthesis route do crystallize in space group I4/mmm. These samples exhibit
+magnetic transitions at ~150 K with significant branching of zfc
+(zero-field-cooled) and fc (field-cooled) magnetization and a sharp cusp in zfc
+at ~ 100 K, followed by a superconducting transition at lower temperatures. All
+the compounds show typical ferromagnetic hysteresis loops in magnetic moment
+(M) versus field (H) magnetization at 5 K. Near saturation of the moments at 5
+K is achieved in above 5 T (Tesla) applied fields with a value of ~ 0.80 muB.
+At low temperatures (5 K) these compounds exhibit both superconductivity and
+ferromagnetism. To our knowledge these are first successfully synthesized
+Ru-1222 compounds with various lanthanides including Y, Dy, and Ho. The results
+are compared with widely reported Gd/Ru-1222 compound.",0211359v1
+2002-12-11,Coercive Field and Magnetization Deficit in Ga(1-x)Mn(x)As Epilayers,"We have studied the field dependence of the magnetization in epilayers of the
+diluted magnetic semiconductor Ga(1-x)Mn(x)As for 0.0135 < x < 0.083.
+Measurements of the low temperature magnetization in fields up to 3 T show a
+significant deficit in the total moment below that expected for full saturation
+of all the Mn spins. These results suggest that the spin state of the
+non-ferromagnetic Mn spins is energetically well separated from the
+ferromagnetism of the bulk of the spins. We have also studied the coercive
+field (Hc) as a function of temperature and Mn concentration, finding that Hc
+decreases with increasing Mn concentration as predicted theoretically.",0212260v1
+2003-08-24,Anomalous magnetization process in frustrated spin ladders,"We study, at T=0, the anomalies in the magnetization curve of the S=1 two-leg
+ladder with frustrated interactions. We focus mainly on the existence of the
+$M=\Ms/2$ plateau, where $\Ms$ is the saturation magnetization. We use
+analytical methods (degenerate perturbation theory and non-Abelian
+bosonization) as well as numerical methods (level spectroscopy and density
+matrix renormalization group), which lead to the consistent conclusion with
+each other. We also touch on the $M=\Ms/4$ and $M=(3/4)\Ms$ plateaux and cusps.",0308473v2
+2003-09-19,Exact eigenstates and macroscopic magnetization jumps in strongly frustrated spin lattices,"For a class of frustrated spin lattices including e.g. the 1D sawtooth chain,
+the 2D kagom\'e and checkerboard, as well as the 3D pyrochlore lattices we
+construct exact product eigenstates consisting of several independent,
+localized one-magnon states in a ferromagnetic background. Important
+geometrical elements of the relevant lattices are triangles being attached to
+polygons or lines. Then the magnons can be trapped on these polygons/lines. If
+the concentration of localized magnons is small they can be distributed
+randomly over the lattice. Increasing the number of localized magnons their
+distribution over the lattice becomes more and more regular and finally the
+magnons condensate in a crystal-like state. The physical relevance of these
+eigenstates emerges in high magnetic fields where they become groundstates of
+the system. As a result a macroscopic magnetization jump appears in the
+zero-temperature magnetization curve just below the saturation field. The
+height of the jump decreases with increasing spin quantum number and vanishes
+in the classical limit. Thus it is a true macroscopic quantum effect.",0309455v1
+2003-10-31,Unconventional magnetism in all-carbon nanofoam,"We report production of nanostructured carbon foam by a high-repetition-rate,
+high-power laser ablation of glassy carbon in Ar atmosphere. A combination of
+characterization techniques revealed that the system contains both sp2 and sp3
+bonded carbon atoms. The material is a novel form of carbon in which
+graphite-like sheets fill space at very low density due to strong hyperbolic
+curvature, as proposed for ?schwarzite?. The foam exhibits ferromagnetic-like
+behaviour up to 90 K, with a narrow hysteresis curve and a high saturation
+magnetization. Such magnetic properties are very unusual for a carbon
+allotrope. Detailed analysis excludes impurities as the origin of the magnetic
+signal. We postulate that localized unpaired spins occur because of topological
+and bonding defects associated with the sheet curvature, and that these spins
+are stabilized due to the steric protection offered by the convoluted sheets.",0310751v1
+2004-11-26,The spin-half Heisenberg antiferromagnet on the square-kagomé lattice: Ground state and low-lying excitations,"We discuss the ground state and the low-lying excitations of the spin-half
+Heisenberg antiferromagnet on the two-dimensional square-kagome lattice. This
+magnetic system belongs to the class of highly frustrated spin systems with an
+infinite non-trivial degeneracy of the classical ground state as it is known
+also for the Heisenberg antiferromagnet on the kagome and on the star lattice.
+The quantum ground state of the spin-half system is a quantum paramagnet likely
+with a finite spin gap and with a large number of non-magnetic excitations
+within this gap. The magnetization versus field curve shows plateaux as well as
+a macroscopic magnetization jump to saturation due to independent localized
+magnon states.",0411673v1
+2004-11-26,Study of the magnetic penetration depth in RbOs_2O_6,"Measurements of the magnetic field penetration depth \lambda in the
+pyrochlore superconductor RbOs_2O_6 (T_c\simeq6.3 K) were carried out by means
+of the muon-spin-rotation (\muSR) technique. At low temperatures
+\lambda^{-2}(T) saturates and becomes constant below T\simeq 0.2T_c, in
+agreement with what is expected for weak-coupled s-wave BCS superconductors.
+The value of \lambda at T=0 was found to be in the range of 250 nm to 300 nm.
+\muSR and equilibrium magnetization measurements both reveal that at low
+temperatures $\lambda$ is almost (at the level of 10%) independent of the
+applied magnetic field. This result suggests that the superconducting energy
+gap in RbOs_2O_6 is isotropic.",0411674v1
+2004-12-22,Investigation of the growth and magnetic properties of highly oriented films of the Heusler alloy Co2MnSi on GaAs(001),"Highly (001) oriented thin films of Co2MnSi have been grown on lattice
+matched GaAs(001) without a buffer layer. Stoichiometric films exhibited a
+saturation magnetization slightly reduced from the bulk value and films grown
+at the highest substrate temperature of 689 K showed the lowest resistivity (33
+micro.ohm.cm at 4.2 K) and the lowest coercivity (14 Oe). The spin polarization
+of the transport current was found to be of the order of 55% as determined by
+point contact Andreev reflection spectroscopy. The reduced magnetization
+obtained was attributed to the antiferromagnetic Mn2As phase. Twofold in-plane
+magnetic anisotropy was observed due to the inequivalence of the <110>
+directions, and this was attributed to the nature of the bonding at the
+reconstructed GaAs surface.",0412636v1
+2005-01-14,Ground states of a frustrated spin-1/2 antifferomagnet: Cs_2CuCl_4 in a magnetic field,"We present detailed calculations of the magnetic ground state properties of
+Cs$_2$CuCl$_4$ in an applied magnetic field, and compare our results with
+recent experiments. The material is described by a spin Hamiltonian, determined
+with precision in high field measurements, in which the main interaction is
+antiferromagnetic Heisenberg exchange between neighboring spins on an
+anisotropic triangular lattice. An additional, weak Dzyaloshinkii-Moriya
+interaction introduces easy-plane anisotropy, so that behavior is different for
+transverse and longitudinal field directions. We determine the phase diagram as
+a function of field strength for both field directions at zero temperature,
+using a classical approximation as a first step. Building on this, we calculate
+the effect of quantum fluctuations on the ordering wavevector and components of
+the ordered moments, using both linear spinwave theory and a mapping to a Bose
+gas which gives exact results when the magnetization is almost saturated. Many
+aspects of the experimental data are well accounted for by this approach.",0501347v1
+2005-09-09,Magnetic Chains Created by Polymer-Induced Assembly of Hollow Cobalt Nanoparticles,"Magnetic chains of hollow cobalt nanoparticles (450-750 nm) have been
+synthesized by using poly(vinyl pyrrolidone) (PVP) as a template in an ethylene
+glycol solution. In this process, CoCl2.6H2O was reduced by N2H4.H2O in the
+presence of PVP. All of the Co nanoparticles are hollow with a shell of 40 nm
+and self-assembled into a chainlike structure that is as long as ~10 micron. At
+300 K, the branched hollow Co nanoparticle chains exhibit a saturation
+magnetization of 37.5 emu/g, a remnant magnetization of approximately 1.55
+emu/g, and a coercivity of about 66 Oe, which is more than an order of
+magnitude larger than that of the bulk",0509237v1
+2005-11-04,Low Temperature Thermodynamic Properties of the Heavy Fermion Compound YbAgGe Close to the Field-Induced Quantum Critical Point,"We present temperature and field dependent heat capacity and magnetization
+data taken at temperatures down to 50 mK and in an applied magnetic field up to
+11.5 Tesla for YbAgGe, a heavy-fermion compound with a field induced quantum
+critical point. These data clearly indicate that the same electronic degrees of
+freedom are responsible for the features seen in both specific heat and
+magnetization data. In addition, they further refine the different boundaries
+suggested for the H - T phase diagram of YbAgGe through previous,
+magneto-transport measurements, and allow for further understanding of
+different phases on the H - T phase diagram, in particular, clearly
+disconnecting the field-induced quantum critical point in YbAgGe from any sort
+of saturation of the Yb moment in higher applied magnetic field.",0511125v1
+2006-01-12,"Electronic structure, magnetic and optical properties of intermetallic compounds R2Fe17 (R=Pr,Gd)","In this paper we report comprehensive experimental and theoretical
+investigation of magnetic and electronic properties of the intermetallic
+compounds Pr2Fe17 and Gd2Fe17. For the first time electronic structure of these
+two systems was probed by optical measurements in the spectral range of 0.22-15
+micrometers. On top of that charge carriers parameters (plasma frequency and
+relaxation frequency) and optical conductivity s(w) were determined.
+Self-consistent spin-resolved bandstructure calculations within the
+conventional LSDA+U method were performed. Theoretical interpetation of the
+experimental s(w) dispersions indicates transitions between 3d and 4p states of
+Fe ions to be the biggest ones. Qualitatively the line shape of the theoretical
+optical conductivity coincides well with our experimental data. Calculated by
+LSDA+U method magnetic moments per formula unit are found to be in good
+agreement with observed experimental values of saturation magnetization.",0601247v1
+2006-01-12,Commensurate and incommensurate ground states of Cs_2CuCl_4 in a magnetic field,"We present calculations of the magnetic ground state of Cs_2CuCl_4 in an
+applied magnetic field, with the aim of understanding the commensurately
+ordered state that has been discovered in recent experiments. This layered
+material is a realization of a Heisenberg antiferromagnet on an anisotropic
+triangular lattice. Its behavior in a magnetic field depends on field
+orientation, because of weak Dzyaloshinskii-Moriya interactions.We study the
+system by mapping the spin-1/2 Heisenberg Hamiltonian onto a Bose gas with hard
+core repulsion. This Bose gas is dilute, and calculations are controlled, close
+to the saturation field. We find a zero-temperature transition between
+incommensurate and commensurate phases as longitudinal field strength is
+varied, but only incommensurate order in a transverse field. Results for both
+field orientations are consistent with experiment.",0601268v1
+2006-01-12,Magnetic phase transitions in the two-dimensional frustrated quantum antiferromagnet Cs2CuCl4,"We report magnetization and specific heat measurements in the 2D frustrated
+spin-1/2 Heisenberg antiferromagnet Cs2CuCl4 at temperatures down to 0.05 K and
+high magnetic fields up to 11.5 T applied along a, b and c-axes. The low-field
+susceptibility chi (T) M/B shows a broad maximum around 2.8 K characteristic of
+short-range antiferromagnetic correlations and the overall temperature
+dependence is well described by high temperature series expansion calculations
+for the partially frustrated triangular lattice with J=4.46 K and J'/J=1/3. At
+much lower temperatures (< 0.4 K) and in in-plane field (along b and c-axes)
+several new intermediate-field ordered phases are observed in-between the
+low-field incommensurate spiral and the high-field saturated ferromagnetic
+state. The ground state energy extracted from the magnetization curve shows
+strong zero-point quantum fluctuations in the ground state at low and
+intermediate fields.",0601272v2
+2006-02-23,Quantum Metallicity on the High-Field Side of the Superconductor-Insulator Transition,"We investigate ultrathin superconducting TiN films, which are very close to
+the localization threshold. Perpendicular magnetic field drives the films from
+the superconducting to an insulating state, with very high resistance. Further
+increase of the magnetic field leads to an exponential decay of the resistance
+towards a finite value. In the limit of low temperatures, the saturation value
+can be very accurately extrapolated to the universal quantum resistance h/e^2.
+Our analysis suggests that at high magnetic fields a new ground state, distinct
+from the normal metallic state occurring above the superconducting transition
+temperature, is formed. A comparison with other studies on different materials
+indicates that the quantum metallic phase following the magnetic-field-induced
+insulating phase is a generic property of systems close to the disorder-driven
+superconductor-insulator transition.",0602557v2
+2006-03-21,Excitations of a low-dimensional dimerized spin ladder under a magnetic field,"We study the dimerized spin ladder with nearest-neighbor ($J_1$) and
+next-nearest-neighbor ($J_2$) anti-ferromagnetic interaction under a magnetic
+field. We predict the existence of different magnetization plateaus for the
+presence of spin-Peierls interaction on both $J_1$ and $J_2$. Magnetization
+plateau at $m=0$ for $J_1$ dimerization is spontaneous due to XY interaction,
+but it is absent for $J_2$ dimerization, only intrinsic umklapp term leads to
+plateau (spin gap) state for some specific values of XXZ anisotropy ($\Delta$)
+and $J_2$. Here we predict a saturation plateau which is the classical phase of
+the system. There are some numerical support of our analytical approach already
+existing in the literature. The transition from commensurate gapped phase to
+incommensurate Luttinger liquid phase is the Mott-$\delta$ type of transition.",0603545v1
+2006-04-11,Antiferromagnetic coupling and enhanced magnetization in all-ferromagnetic superlattices,"The structural and magnetic properties of a series of superlattices
+consisting of two ferromagnetic metals La$_{0.7}$Sr$_{0.3}$MnO$_3$ (LSMO) and
+SrRuO$_3$ (SRO) grown on (001) oriented SrTiO$_3$ are studied. Superlattices
+with a fixed LSMO layer thickness of 20 unit cells (u.c.) and varying SRO layer
+thickness show a sudden drop in magnetization on cooling through temperature
+where both LSMO and SRO layers are ferromagnetic. This behavior suggests an
+antiferromagnetic coupling between the layers. In addition, the samples having
+thinner SRO layers (n \TEXTsymbol{<} 6) exhibit enhanced saturation
+magnetization at 10 K. These observations are attributed to the possible
+modification in the stereochemistry of the Ru and Mn ions in the interfacial
+region.",0604266v1
+2006-06-09,Magnetic resonance studies of the fundamental spin-wave modes in individual submicron Cu/NiFe/Cu perpendicularly magnetized disks,"Spin wave spectra of perpendicularly magnetized disks with trilayers
+consisting of a 100 nm permalloy (Py) layer sandwiched by two Cu layers of 30
+nm, are measured individually with a Magnetic Resonance Force Microscope
+(MRFM). It is demonstrated by 3D micromagnetic simulations that in disks having
+sub-micron size diameters, the lowest energy spin wave mode of the saturated
+state is not spatially uniform but rather is localized at the center of the
+Py/Cu interface in the region of a minimum demagnetizing field.",0606245v3
+2006-08-26,Ferrimagnetic States in S=1/2 Frustrated Heisenberg Chains with Period 3 Exchange Modulation,"Ground state properties of the S=1/2 frustrated Heisenberg chain with period
+3 exchange modulation are investigated using the numerical diagonalization and
+DMRG method. It is known that this model has a magnetization plateau at 1/3 of
+the saturation magnetization M_s. On the other hand, the ground state is
+ferrimagnetic even in the absence of frustration if one of the nearest
+neighbour bond is ferromagnetic and others are antiferromagnetic. In the
+present work, we show that this ferrimagnetic state continues to the region in
+which all bonds are antiferromagnetic if frustration is strong. This state
+further continues to the above mentioned 1/3-plateau state. In between, we also
+find the noncollinear ferrimagnetic phase in which the spontaneous
+magnetization is finite but less than M_s/3. The intuitive interpretation for
+the phase diagram is given and the physical properties of these phases are
+discussed.",0608582v1
+2006-10-05,Magnetic Domain Patterns Depending on the Sweeping Rate of Magnetic Fields,"The domain patterns in a thin ferromagnetic film are investigated in both
+experiments and numerical simulations. Magnetic domain patterns under a zero
+field are usually observed after an external magnetic field is removed. It is
+demonstrated that the characteristics of the domain patterns depend on the
+decreasing rate of the external field, although it can also depend on other
+factors. Our numerical simulations and experiments show the following
+properties of domain patterns: a sea-island structure appears when the field
+decreases rapidly from the saturating field to the zero field, while a
+labyrinth structure is observed for a slowly decreasing field. The mechanism of
+the dependence on the field sweeping rate is discussed in terms of the concepts
+of crystallization.",0610142v3
+2006-10-24,Ferrimagnetic and Long Period Antiferromagnetic Phases in High Spin Heisenberg Chains with D-Modulation,"The ground state properties of the high spin Heisenberg chains with
+alternating single site anisotropy are investigated by means of the numerical
+exact daigonaization and DMRG method. It is found that the ferrimagnetic state
+appears between the Haldane phase and period doubled N\'eel phase for the
+integer spin chains. On the other hand, the transition from the
+Tomonaga-Luttinger liquid state into the ferrimagnetic state takes place for
+the half-odd-integer spin chains. In the ferrimagnetic phase, the spontaneous
+magnetization varies continuously with the modulation amplitude of the single
+site anisotropy. Eventually, the magnetization is locked to fractional values
+of the saturated magnetization. These fractional values satisfy the
+Oshikawa-Yamanaka-Affleck condition. The local spin profile is calculated to
+reveal the physical nature of each state. In contrast to the case of
+frustration induced ferrimagnetism, no incommensurate magnetic superstructure
+is found.",0610660v1
+2006-10-30,"Nucleation of magnetisation reversal, from nanoparticles to bulk materials","We review models for the nucleation of magnetisation reversal, i.e. the
+formation of a region of reversed magnetisation in an initially magnetically
+saturated system. For small particles models for collective reversal, either
+uniform (Stoner-Wohlfarth model) or non-uniform like curling, provide good
+agreement between theory and experiment. For microscopic objects and thin
+films, we consider two models, uniform (Stoner-Wohlfarth) reversal inside a
+nucleation volume and a droplet model, where the free energy of an inverse
+bubble is calculated taking into account volume energy (Zeeman energy) and
+surface tension (domain wall energy). In macroscopic systems, inhomogeneities
+in magnetic properties cause a distribution of energy barriers for nucleation,
+which strongly influences effects of temperature and applied field on
+magnetisation reversal. For these systems, macroscopic material parameters like
+exchange interaction, spontaneous magnetisation and magnetic anisotropy can
+give an indication of the magnetic coercivity, but exact values for nucleation
+fields are, in general, hard to predict.",0610840v2
+2006-12-04,"Structural, magnetic, and transport properties of Co$_2$FeSi Heusler films","We report the deposition of thin Co$_2$FeSi films by RF magnetron sputtering.
+Epitaxial (100)-oriented and L2$_1$ ordered growth is observed for films grown
+on MgO(100) substrates. (110)-oriented films on Al$_2$O$_3$(110) show several
+epitaxial domains in the film plane. Investigation of the magnetic properties
+reveals a saturation magnetization of 5.0 $mu_B/f.u.$ at low temperatures. The
+temperature dependence of the resistivity $rho_{xx}(T)$ exhibits a crossover
+from a T^3.5 law at T<50K to a T^1.65 behaviour at elevated temperatures.
+$rho_{xx}(H)$ shows a small anisotropic magnetoresistive effect. A weak
+dependence of the normal Hall effect on the external magnetic field indicates
+the compensation of electron and hole like contributions at the Fermi surface.",0612073v1
+1998-11-19,Spectrum of Neutral Helium in Strong Magnetic Fields,"We present extensive and accurate calculations for the excited state spectrum
+of spin-polarized neutral helium in a range of magnetic field strengths up to
+$10^{12}$ G. Of considerable interest to models of magnetic white dwarf stellar
+atmospheres, we also present results for the dipole strengths of the low lying
+transitions among these states. Our methods rely on a systematically saturated
+basis set approach to solving the Hartree--Fock self-consistent field
+equations, combined with an ``exact'' stochastic method to estimate the
+residual basis set truncation error and electron correlation effects. We also
+discuss the applicability of the adiabatic approximation to strongly magnetized
+multi-electron atoms.",9811041v1
+2002-12-20,Orbital magnetism in axially deformed sodium clusters: From scissors mode to dia-para magnetic anisotropy,"Low-energy orbital magnetic dipole excitations, known as scissors mode (SM),
+are studied in alkali metal clusters. Subsequent dynamic and static effects are
+explored. The treatment is based on a self-consistent microscopic approach
+using the jellium approximation for the ionic background and the Kohn-Sham mean
+field for the electrons. The microscopic origin of SM and its main features
+(structure of the mode in light and medium clusters, separation into low- and
+high-energy plasmons, coupling high-energy M1 scissors and E2 quadrupole
+plasmons, contributions of shape isomers, etc) are discussed. The scissors M1
+strength acquires large values with increasing cluster size. The mode is
+responsible for the van Vleck paramagnetism of spin-saturated clusters. Quantum
+shell effects induce a fragile interplay between Langevin diamagnetism and van
+Vleck paramagnetism and lead to a remarkable dia-para anisotropy in magnetic
+susceptibility of particular light clusters. Finally, several routes for
+observing the SM experimentally are discussed.",0212084v1
+2004-10-07,Numerical study of dynamo action at low magnetic Prandtl numbers,"We present a three--pronged numerical approach to the dynamo problem at low
+magnetic Prandtl numbers $P_M$. The difficulty of resolving a large range of
+scales is circumvented by combining Direct Numerical Simulations, a
+Lagrangian-averaged model, and Large-Eddy Simulations (LES). The flow is
+generated by the Taylor-Green forcing; it combines a well defined structure at
+large scales and turbulent fluctuations at small scales. Our main findings are:
+(i) dynamos are observed from $P_M=1$ down to $P_M=10^{-2}$; (ii) the critical
+magnetic Reynolds number increases sharply with $P_M^{-1}$ as turbulence sets
+in and then saturates; (iii) in the linear growth phase, the most unstable
+magnetic modes move to small scales as $P_M$ is decreased and a Kazantsev
+$k^{3/2}$ spectrum develops; then the dynamo grows at large scales and modifies
+the turbulent velocity fluctuations.",0410046v1
+2005-09-08,On the inverse cascade of magnetic helicity,"We study the inverse cascade of magnetic helicity in conducting fluids by
+investigating the detailed transfer of helicity between different spherical
+shells in Fourier space in direct numerical simulations of three-dimensional
+magnetohydrodynamics (MHD). Two different numerical simulations are used, one
+where the system is forced with an electromotive force in the induction
+equation, and one in which the system is forced mechanically with an ABC flow
+and the magnetic field is solely sustained by a dynamo action. The magnetic
+helicity cascade at the initial stages of both simulations is observed to be
+inverse and local (in scale space) in the large scales, and direct and local in
+the small scales. When saturation is approached most of the helicity is
+concentrated in the large scales and the cascade is non-local. Helicity is
+transfered directly from the forced scales to the largest scales. At the same
+time, a smaller in amplitude direct cascade is observed from the largest scale
+to small scales.",0509069v1
+2007-04-02,Quasi-quartet crystal electric field ground state in a tetragonal CeAg$_2$Ge$_2$ single crystal,"We have successfully grown the single crystals of CeAg$_2$Ge$_2$, for the
+first time, by flux method and studied the anisotropic physical properties by
+measuring the electrical resistivity, magnetic susceptibility and specific
+heat. We found that CeAg$_2$Ge$_2$ undergoes an antiferromagnetic transition at
+$T_{\rm N}$ = 4.6 K. The electrical resistivity and susceptibility data reveal
+strong anisotropic magnetic properties. The magnetization measured at $T$ = 2 K
+exhibited two metamagnetic transitions at $H_{\rm m1}$ = 31 kOe and $H_{\rm
+m2}$ = 44.7 kOe, for $H \parallel$ [100] with a saturation magnetization of 1.6
+$\mu_{\rm B}$/Ce. The crystalline electric field (CEF) analysis of the inverse
+susceptibility data reveals that the ground state and the first excited states
+of CeAg$_2$Ge$_2$ are closely spaced indicating a quasi-quartet ground state.
+The specific heat data lend further support to the presence of closely spaced
+energy levels.",0704.0119v1
+2007-05-17,Ferromagnetism in nanoscale BiFeO3,"A remarkably high saturation magnetization of ~0.4mu_B/Fe along with room
+temperature ferromagnetic hysteresis loop has been observed in nanoscale (4-40
+nm) multiferroic BiFeO_3 which in bulk form exhibits weak magnetization
+(~0.02mu_B/Fe) and an antiferromagnetic order. The magnetic hysteresis loops,
+however, exhibit exchange bias as well as vertical asymmetry which could be
+because of spin pinning at the boundaries between ferromagnetic and
+antiferromagnetic domains. Interestingly, like in bulk BiFeO_3, both the
+calorimetric and dielectric permittivity data in nanoscale BiFeO_3 exhibit
+characteristic features at the magnetic transition point. These features
+establish formation of a true ferromagnetic-ferroelectric system with a
+coupling between the respective order parameters in nanoscale BiFeO_3.",0705.2498v1
+2007-08-23,Sharp Magnetic Field Dependence of the 2D Hall Coefficient Induced by Classical Memory Effects,"We show that a sharp dependence of the Hall coefficient $R$ on the magnetic
+field $B$ arises in two-dimensional electron systems with randomly located
+strong scatterers. The phenomenon is due to classical memory effects. We
+calculate analytically the dependence $R(B)$ for the case of scattering by hard
+disks of radius $a$, randomly distributed with concentration $n_0\ll1/a^2$. We
+demonstrate that in very weak magnetic fields ($\omega_c\tau \lesssim n_0a^2$)
+memory effects lead to a considerable renormalization of the Boltzmann value of
+the Hall coefficient: $\delta R / R \sim 1 .$ With increasing magnetic field,
+the relative correction to $R$ decreases, then changes sign, and saturates at
+the value $\delta R / R \sim -n_0a^2 .$ We also discuss the effect of the
+smooth disorder on the dependence of $R$ on $B$.",0708.3165v1
+2008-01-09,"Nanoscale spin-polarization in dilute magnetic semiconductor (In,Mn)Sb","Results of point contact Andreev reflection (PCAR) experiments on (In,Mn)Sb
+are presented and analyzed in terms of current models of charge conversion at a
+superconductor-ferromagnet interface. We investigate the influence of surface
+transparency, and study the crossover from ballistic to diffusive transport
+regime as contact size is varied. Application of a Nb tip to a (In,Mn)Sb sample
+with Curie temperature Tc of 5.4 K allowed the determination of
+spin-polarization when the ferromagnetic phase transition temperature is
+crossed. We find a striking difference between the temperature dependence of
+the local spin polarization and of the macroscopic magnetization, and
+demonstrate that nanoscale clusters with magnetization close to the saturated
+value are present even well above the magnetic phase transition temperature.",0801.1464v1
+2008-05-14,Persistent Spin Dynamics in the $S=1/2$ V$_{15}$ Molecular Nano-Magnet,"We present muon spin lattice relaxation measurements in the V15 spin 1/2
+molecular nano-magnet. We find that the relaxation rate in low magnetic fields
+(<5 kG) is temperature independent below ~10 K, implying that the molecular
+spin is dynamically fluctuating down to 12 mK. These measurements show that the
+fluctuation time increases as the temperature is decreased and saturates at a
+value of ~6 nsec at low temperatures. The fluctuations are attributed to V15
+molecular spin dynamics perpendicular to the applied magnetic field direction,
+induced by coupling between the molecular spin and nuclear spin bath in the
+system.",0805.2164v1
+2008-08-11,Monitoring of band gap and magnetic state of graphene nanoribbons through vacancies,"Using first-principles plane wave calculations we predict that electronic and
+magnetic properties of graphene nanoribbons can be affected by defect-induced
+itinerant states. The band gaps of armchair nanoribbons can be modified by
+hydrogen saturated holes. Defects due to periodically repeating vacancy or
+divacancies induce metallization, as well as magnetization in non-magnetic
+semiconducting nanoribbons due to the spin-polarization of local defect states.
+Antiferromagnetic ground state of semiconducting zigzag ribbons can change to
+ferrimagnetic state upon creation of vacancy defects, which reconstruct and
+interact with edge states. Even more remarkable is that all these effects of
+vacancy defects are found to depend on their geometry and position relative to
+edges. It is shown that these effects can, in fact, be realized without really
+creating defects.",0808.1468v1
+2008-08-15,19F nuclear spin relaxation and spin diffusion effects in the single ion magnet LiYF4:Ho3+,"Temperature and magnetic field dependences of the 19F nuclear spin-lattice
+relaxation in a single crystal of LiYF4 doped with holmium are described by an
+approach based on a detailed consideration of the magnetic dipole-dipole
+interactions between nuclei and impurity paramagnetic ions and nuclear spin
+diffusion processes. The observed non-exponential long time recovery of the
+nuclear magnetization after saturation at intermediate temperatures is in
+agreement with predictions of the spin-diffusion theory in a case of the
+diffusion limited relaxation. At avoided level crossings in the spectrum of
+electron-nuclear states of the Ho3+ ion, rates of nuclear spin-lattice
+relaxation increase due to quasi-resonant energy exchange between nuclei and
+paramagnetic ions, in contrast to the predominant role played by electronic
+cross-relaxation processes in the low-frequency ac-susceptibility.",0808.2137v1
+2008-09-23,Localized magnetorotational instability and its role in the accretion disc dynamo,"(Abriged) The magnetorotational instability (MRI) is believed to be an
+efficient way to transport angular momentum in accretion discs. It has also
+been suggested as a way to amplify magnetic fields in discs, the instability
+acting as a nonlinear dynamo. Recent numerical work has shown that a
+large-scale magnetic field, which is predominantly azimuthal, can be sustained
+by motions driven by the MRI of this same field. Following this idea, we
+present an analytical calculation of the MRI in the presence of an azimuthal
+field with a non-trivial vertical structure. We find that the mean radial EMF
+associated to MRI modes tends to reduce the magnetic energy, acting like a
+turbulent resistivity by mixing the non-uniform azimuthal field. Meanwhile, the
+azimuthal EMF generates a radial field that, in combination with the Keplerian
+shear, tends to amplify the azimuthal field and can therefore assist in the
+dynamo process. This effect, however, is reversed for sufficiently strong
+azimuthal fields, naturally leading to a saturation of the dynamo and possibly
+to a cyclic behaviour of the magnetic field, as found in previous numerical
+works.",0809.3871v1
+2008-10-11,The bifurcation periods in low-mass X-ray binaries: the effect of magnetic braking and mass loss,"The bifurcation period in low-mass X-ray binaries is the initial orbital pe-
+riod which separates the formation of converging systems (which evolve with
+decreasing orbital periods until the donor becomes degenerate) from the
+diverging systems (which evolve with increasing orbital periods until the donor
+star loses its envelope and a wide detached binary is formed). We calculate
+systematically the bifurcation periods of binary systems with a 1.4M_\sun
+neutron star and a 0.5-2M_\sun donor star, taking into account different kinds
+of magnetic braking and mass loss mechanisms. Our results show that the
+saturated magnetic braking can considerably decrease the values of bifurcation
+period compared to the traditional magnetic braking, while the influence of
+mass loss mechanisms on bifurcation periods is quite weak. We also develop a
+semi-analytical method to compute the bifurcation period, the result of which
+agrees well with the numerical method in the leading order.",0810.2009v2
+2008-10-14,Turbulent dynamos with shear and fractional helicity,"Dynamo action owing to helically forced turbulence and large-scale shear is
+studied using direct numerical simulations. The resulting magnetic field
+displays propagating wave-like behavior. This behavior can be modelled in terms
+of an \alpha\Omega dynamo. In most cases super-equipartition fields are
+generated. By varying the fraction of helicity of the turbulence the
+regeneration of poloidal fields via the helicity effect (corresponding to the
+\alpha-effect) is regulated. The saturation level of the magnetic field in the
+numerical models is consistent with a linear dependence on the ratio of the
+fractional helicities of the small and large-scale fields, as predicted by a
+simple nonlinear mean-field model. As the magnetic Reynolds number (Rm) based
+on the wavenumber of the energy-carrying eddies is increased from 1 to 180, the
+cycle frequency of the large-scale field is found to decrease by a factor of
+about 6 in cases where the turbulence is fully helical. This is interpreted in
+terms of the turbulent magnetic diffusivity, which is found to be only weakly
+dependent on Rm.",0810.2298v2
+2008-11-26,"Magnetic order in CaFe1-xCoxAsF (x = 0, 0.06, 0.12) superconductor compounds","A Neutron Powder Diffraction (NPD) experiment has been performed to
+investigate the structural phase transition and magnetic order in CaFe1-xCoxAsF
+superconductor compounds (x = 0, 0.06, 0.12). The parent compound CaFeAsF
+undergoes a tetragonal to orthorhombic phase transition at 134(3) K, while the
+magnetic order in form of a spin-density wave (SDW) sets in at 114(3) K. The
+antiferromagnetic structure of the parent compound has been determined with a
+unique propagation vector k = (1,0,1) and the Fe saturation moment of 0.49(5)uB
+aligned along the long a-axis. With increasing Co doping, the long range
+antiferromagnetic order has been observed to coexist with superconductivity in
+the orthorhombic phase of the underdoped CaFe0.94Co0.06AsF with a reduced Fe
+moment (0.15(5)uB). Magnetic order is completely suppressed in optimally doped
+CaFe0.88Co0.12AsF. We argue that the coexistence of SDW and superconductivity
+might be related to mesoscopic phase separation.",0811.4418v2
+2008-12-31,Cosmic-ray driven dynamo in galactic disks,"We present new developments on the Cosmic--Ray driven, galactic dynamo,
+modeled by means of direct, resistive CR--MHD simulations, performed with ZEUS
+and PIERNIK codes. The dynamo action, leading to the amplification of
+large--scale galactic magnetic fields on galactic rotation timescales, appears
+as a result of galactic differential rotation, buoyancy of the cosmic ray
+component and resistive dissipation of small--scale turbulent magnetic fields.
+Our new results include demonstration of the global--galactic dynamo action
+driven by Cosmic Rays supplied in supernova remnants. An essential outcome of
+the new series of global galactic dynamo models is the equipartition of the gas
+turbulent energy with magnetic field energy and cosmic ray energy, in saturated
+states of the dynamo on large galactic scales.",0901.0111v1
+2009-06-09,Partial ferromagnetic ordering and indirect exchange interaction in spatially anisotropic kagome antiferromagnet Cs_2Cu_3CeF_{12},"We report the crystal structure and unconventional magnetic ordering of
+Cs_2Cu_3CeF_{12}, which is composed of buckled kagome lattice of Cu^{2+} ions.
+The exchange network in the buckled kagome lattice is fairly anisotropic, so
+that the present spin system can be divided into two subsystems: alternating
+Heisenberg chains with strong antiferromagnetic exchange interactions and
+dangling spins. Although the direct exchange interactions between neighboring
+spins were found to be all antiferromagnetic, ferromagnetic magnetic ordering
+of the dangling spins was observed. Magnetization exhibits a plateau at
+one-third of the saturation magnetization. These observations can be understood
+in terms of the indirect interaction between dangling spins mediated by the
+chain spin.",0906.1628v2
+2009-06-11,Magnetization study on the field-induced quantum critical point in YbRh_2Si_2,"We study the field-induced quantum critical point (QCP) in YbRh$_2$Si$_2$ by
+low-temperature magnetization, $M(T)$, and magnetic Gr\""uneisen ratio,
+$\Gamma_{\rm mag}$, measurements and compare the results with previous thermal
+expansion, $\beta(T)$, and critical Gr\""uneisen ratio, $\Gamma^{cr}(T)$, data
+on YbRh$_2$(Si$_{0.95}$Ge$_{0.05}$)$_2$. In the latter case, a slightly
+negative chemical pressure has been used to tune the system towards its
+zero-field QCP. The magnetization derivative $-dM/dT$ is far more singular than
+thermal expansion, reflecting a strongly temperature dependent pressure
+derivative of the field at constant entropy, $(dH/dP)_S=V_m\beta/(dM/dT)$
+($V_m$: molar volume), which saturates at $(0.15\pm 0.04)$ T/GPa for $T\to 0$.
+The line $T^\star(H)$, previously observed in Hall- and thermodynamic
+measurements, separates regimes in $T$-$H$ phase space of stronger
+$(\epsilon>1$) and weaker $(\epsilon<1$) divergent $\Gamma_{\rm mag}(T)\propto
+T^{-\epsilon}$.",0906.2097v1
+2009-07-02,Exploring the spin-1/2 frustrated square lattice model with high-field magnetization measurements,"We report on high-field magnetization measurements for a number of layered
+vanadium phosphates that were recently recognized as spin-1/2 frustrated square
+lattice compounds with ferromagnetic nearest-neighbor couplings (J_1) and
+antiferromagnetic next-nearest-neighbor couplings (J_2). The saturation fields
+of the materials lie in the range from 4 to 24 T and show excellent agreement
+with the previous estimates of the exchange couplings deduced from low-field
+thermodynamic measurements. The consistency of the high-field data with the
+regular frustrated square lattice model provides experimental evidence for a
+weak impact of spatial anisotropy on the nearest-neighbor couplings in layered
+vanadium phosphates. The variation of the J_2/J_1 ratio within the compound
+family facilitates the experimental access to the evolution of the
+magnetization curve upon the change of the frustration magnitude. Our results
+support the recent theoretical prediction by Thalmeier et al. [Phys. Rev. B,
+77, 104441 (2008)] and give evidence for the enhanced bending of the
+magnetization curves due to the increasing frustration of the underlying spin
+system.",0907.0391v1
+2009-10-28,Novel electronic and magnetic properties of BN sheet decorated with hydrogen and fluorine,"First principles calculations based on density functional theory reveal some
+unusual properties of BN sheet functionalized with hydrogen and fluorine. These
+properties differ from those of similarly functionalized graphene even though
+both share the same honeycomb structure. (1) Unlike graphene which undergoes a
+metal to insulator transition when fully hydrogenated, the band gap of the BN
+sheet significantly narrows when fully saturated with hydrogen. Furthermore,
+the band gap of the BN sheet can be tuned from 4.7 eV to 0.6 eV and the system
+can be a direct or an indirect semiconductor or even a half-metal depending
+upon surface coverage. (2) Unlike graphene, BN sheet has hetero-atomic
+composition, when co-decorated with H and F, it can lead to anisotropic
+structures with rich electronic and magnetic properties. (3) Unlike graphene,
+BN sheets can be made ferromagnetic, antiferromagnetic, or magnetically
+degenerate depending upon how the surface is functionalized. (4) The stability
+of magnetic coupling of functionalized BN sheet can be further modulated by
+applying external strain. Our study highlights the potential of functionalized
+BN sheets for novel applications.",0910.5287v1
+2009-11-11,Dilute-Bose-Gas Approach to ground state phases of 3D quantum helimagnets under high magnetic field,"We study high-field phase diagram and low-energy excitations of
+three-dimensional quantum helimagnets. Slightly below the saturation field, the
+emergence of magnetic order may be mathematically viewed as Bose-Einstein
+condensation (BEC) of magnons. The method of dilute Bose gas enables an
+unbiased quantitative analysis of quantum effects in three-dimensional
+helimagnets and thereby three phases are found: cone, coplanar fan and an
+attraction-dominant one. To investigate the last phase, we extend the usual BEC
+approach so that we can handle 2-magnon bound states. In the case of 2-magnon
+BEC, the transverse magnetization vanishes and long-range order occurs in the
+quadrupolar channel (spin-nematic phase). As an application, we map out the
+phase diagram of a 3D helimagnet which consists of frustrated J1-J2 chains
+coupled by an interchain interaction J3.",0911.2186v2
+2009-11-22,Structural and magnetic study of a dilute magnetic semiconductor: Fe doped CeO2 nanoparticles,"This paper reports the effect of Fe doping on the structure and room
+temperature ferromagnetism of CeO2 nanoparticles. X-ray diffraction and
+selective area electron diffraction measurement reflects that Ce1-xFexO2 (x =
+0.0 - 0.07) nanoparticles exhibit single phase nature with cubic structure and
+none of the sample showed the presence of any secondary phase. The mean
+particle size calculated by using a transmission electron microscopy
+measurement was found to increase with increase in Fe content. DC magnetization
+measurements performed at room temperature indicates that all the samples
+exhibit ferromagnetism. The saturation magnetic moment has been found to
+increase with an increase in the Fe content.",0911.4225v1
+2009-11-24,Magnetic properties and atomic structure of La(2/3)Ca(1/3)MnO(3)-YBa(2)Cu(3)O(7) heterointerfaces,"A heterostructure comprised of a 2.7 nm (7 unit-cell) thick layer of the
+metallic ferromagnet La(2/3)Ca(1/3)MnO(3) and two 50 nm thick layers of the
+high-temperature superconductor YBa(2)Cu(3)O(7) epitaxially grown on (100)
+SrTiO3 by pulsed-laser deposition was characterized by magnetization
+measurements and spherical-aberration-corrected high-resolution transmission
+electron microscopy (HRTEM). The saturation magnetization is about half of that
+in bulk La(2/3)Ca(1/3)MnO(3). A massive reduction of the magnetization
+previously inferred from sputter-deposited La(2/3)Ca(1/3)MnO(3)-YBa(2)Cu(3)O(7)
+heterostructures can be ruled out. HRTEM image analysis, combined with image
+simulation and a focus series reconstruction, revealed atomically sharp
+epitaxial structures with stacking sequences -(La,Ca)O-CuO2- and -BaO-MnO- at
+the top and bottom interface.",0911.4606v1
+2009-12-21,Magnetic Phase Transitions in NdCoAsO,"Magnetization measurements reveal that NdCoAsO undergoes three magnetic phase
+transitions below room temperature. The crystal and magnetic structures of
+NdCoAsO have been determined by powder neutron diffraction, and the effects of
+the phase transitions on physical properties are reported. Near 69 K a
+ferromagnetic state emerges with a small saturation moment of about 0.2 Bohr
+magnetons, likely on Co atoms. At 14 K the material enters an antiferromagnetic
+state with propagation vector (0 0 1/2) and small ordered moments (~0.4 Bohr
+magnetons) on Co and Nd. Near 3.5 K a third transition is observed, and
+corresponds to the antiferromagnetic ordering, with the same propagation
+vector, of larger moments on Nd reaching 1.30(2) Bohr magnetons at 1.4 K. In
+addition, transport properties and heat capacity results are presented, and
+show anomalies at all three phase transitions.",0912.4237v2
+2010-02-12,The Parker Scenario for Coronal Heating as an MHD Turbulence Problem,"The Parker or field line tangling model of coronal heating is investigated
+through long-time high-resolution simulations of the dynamics of a coronal loop
+in cartesian geometry within the framework of reduced magnetohydrodynamics
+(RMHD). Slow photospheric motions induce a Poynting flux which saturates by
+driving an anisotropic turbulent cascade dominated by magnetic energy and
+characterized by current sheets elongated along the axial magnetic field.
+Increasing the value of the axial magnetic field different regimes of MHD
+turbulence develop with a bearing on coronal heating rates. In physical space
+magnetic field lines at the scale of convection cells appear only slightly
+bended in agreement with observations of large loops of current (E)UV and X-ray
+imagers.",1002.2631v1
+2010-03-11,Structural and Magnetic Properties of Nanosized Barium Hexaferrite Powders Obtained by Microemulsion Technique,"Thin hexagonal barium hexaferrite particles synthesized using the
+microemulsion technique were studied. A water-in-oil reverse microemulsion
+system with cetyltrimethylammonium bromide (CTAB) as a cationic surfactant,
+n-butanol as a co-surfactant, n-hexanol as a continuous oil phase, and an
+aqueous phase were used. The microstructural and magnetic properties were
+investigated. The particles obtained were mono-domain with average particle
+size 280 nm. The magnetic properties of the powder were investigated at 4.2 K
+and at room temperature. The saturation magnetization was 48.86 emu/g and the
+coercivity, 2.4 x 105 A/m at room temperature. The anisotropy field Ha and
+magneto-crystalline anisotropy K1 were 1.4 x 106 A/m and 2.37 x 105 J/m3,
+respectively.",1003.2276v1
+2010-05-31,Driven weak to strong pinning crossover in partially nanopatterned 2H-NbSe2 single crystal,"Investigations into the heterogeneous pinning properties of the vortex state
+created by partially nano-patterning single crystals of 2H-NbSe2 reveal an
+atypical magnetization response which is significantly drive dependent.
+Analysis of the magnetization response shows non-monotonic behavior of the
+magnetization relaxation rate with varying magnetic field sweep rate. With all
+the patterned pinning centers saturated with vortices, we find that the pinning
+force experienced by the vortices continues to increase with increasing drive.
+Our studies reveal an unconventional dynamic weak to strong pinning crossover
+where the flow of the vortex state appears to be hindered or jammed as it is
+driven harder through the interstitial voids in the patterned pinning lattice.",1005.5641v1
+2010-05-31,New high magnetic field phase of the frustrated $S=1/2$ chain compound LiCuVO$_4$,"Magnetization of the frustrated $S=1/2$ chain compound LiCuVO$_4$, focusing
+on high magnetic field phases, is reported. Besides a spin-flop transition and
+the transition from a planar spiral to a spin modulated structure observed
+recently, an additional transition was observed just below the saturation
+field. This newly observed magnetic phase is considered as a spin nematic
+phase, which was predicted theoretically but was not observed experimentally.
+The critical fields of this phase and its dM/dH curve are in good agreement
+with calculations performed in a microscopic model (M. E. Zhitomirsky and H.
+Tsunetsugu, preprint, arXiv:1003.4096v2).",1005.5668v2
+2010-06-08,Linear-Temperature Dependence of Static Magnetic Susceptibility in LaFeAsO from Dynamical Mean-Field Theory,"In this Letter we report the LDA+DMFT (method combining Local Density
+Approximation with Dynamical Mean-Field Theory) results for magnetic properties
+of parent superconductor LaFeAsO in paramagnetic phase. Calculated uniform
+magnetic susceptibility shows linear dependence at intermediate temperatures in
+agreement with experimental data. For high temperatures ($>$1000 K)
+calculations show saturation and then susceptibility decreases with
+temperature. Contributions to temperature dependence of the uniform
+susceptibility are strongly orbitally dependent. It is related to the form of
+the orbitally-resolved spectral functions near the Fermi energy with strong
+temperature dependent narrow peaks for some of the orbitals. Our results
+demonstrate that linear-temperature dependence of static magnetic
+susceptibility in pnictide superconductors can be reproduced without invoking
+antiferromagnetic fluctuations.",1006.1509v2
+2010-06-29,Magnetic properties of exchange biased and of unbiased oxide/permalloy thin layers: a ferromagnetic resonance and Brillouin scattering study,"Microstrip ferromagnetic resonance and Brillouin scattering are used to
+provide a comparative determination of the magnetic parameters of thin
+permalloy layers interfaced with a non-magnetic (Al2O3) or with an
+antiferromagnetic oxide (NiO). It is shown that the perpendicular anisotropy is
+monitored by an interfacial surface energy term which is practically
+independent of the nature of the interface. In the investigated interval of
+thicknesses (5-25 nm) the saturation magnetisation does not significantly
+differ from the reported one in bulk permalloy. In-plane uniaxial anisotropy
+and exchange-bias anisotropy are also derived from this study of the dynamic
+magnetic excitations and compared to our independent evaluations using
+conventional magnetometry",1006.5598v1
+2010-09-06,Energy oscillations and a possible route to chaos in a modified Riga dynamo,"Starting from the present version of the Riga dynamo experiment with its
+rotating magnetic eigenfield dominated by a single frequency we ask for those
+modifications of this set-up that would allow for a non-trivial magnetic field
+behaviour in the saturation regime. Assuming an increased ratio of azimuthal to
+axial flow velocity, we obtain energy oscillations with a frequency below the
+eigenfrequency of the magnetic field. These new oscillations are identified as
+magneto-inertial waves that result from a slight imbalance of Lorentz and
+inertial forces. Increasing the azimuthal velocity further, or increasing the
+total magnetic Reynolds number, we find transitions to a chaotic behaviour of
+the dynamo.",1009.1051v1
+2010-09-14,Uncompensated magnetization and exchange-bias field in La$_{0.7}$Sr$_{0.3}$MnO$_3$/YMnO$_3$ bilayers: The influence of the ferromagnetic layer,"We studied the magnetic behavior of bilayers of multiferroic and nominally
+antiferromagnetic o-YMnO$_3$ (375~nm thick) and ferromagnetic
+La$_{0.7}$Sr$_{0.3}$MnO$_3$ and La$_{0.67}$Ca$_{0.33}$MnO$_3$ ($8 \ldots
+225~$nm), in particular the vertical magnetization shift $M_E$ and exchange
+bias field $H_E$ for different thickness and magnetic dilution of the
+ferromagnetic layer at different temperatures and cooling fields. We have found
+very large $M_E$ shifts equivalent to up to 100\% of the saturation value of
+the o-YMO layer alone. The overall behavior indicates that the properties of
+the ferromagnetic layer contribute substantially to the $M_E$ shift and that
+this does not correlate straightforwardly with the measured exchange bias field
+$H_E$.",1009.2619v1
+2010-11-29,Lagrangian coherent structures in nonlinear dynamos,"Turbulence and chaos play a fundamental role in stellar convective zones
+through the transportof particles, energy and momentum, and in fast dynamos,
+through the stretching, twisting and folding of magnetic flux tubes. A
+particularly revealing way to describe turbulent motions is through the
+analysis of Lagrangian coherent structures (LCS), which are material lines or
+surfaces that act as transport barriers in the fluid. We report the detection
+of Lagrangian coherent structures in helical MHD dynamo simulations with scale
+separation. In an ABC--flow, two dynamo regimes, a propagating coherent
+mean--field regime and an intermittent regime, are identified as the magnetic
+diffusivity is varied. The sharp contrast between the chaotic tangle of
+attracting and repelling LCS in both regimes permits a unique analysis of the
+impact of the magnetic field on the velocity field. In a second example, LCS
+reveal the link between the level of chaotic mixing of the velocity field and
+the saturation of a large--scale dynamo when the magnetic field exceeds the
+equipartition value.",1011.6327v2
+2010-12-13,Three-Dimensional Relativistic Magnetohydrodynamic Simulations of Current-Driven Instability. II. Relaxation of Pulsar Wind Nebula,"We have investigated the relaxation of a hydrostatic hot plasma column
+containing toroidal magnetic field by the Current-Driven (CD) kink instability
+as a model of pulsar wind nebulae. In our simulations the CD kink instability
+is excited by a small initial velocity perturbation and develops turbulent
+structure inside the hot plasma column. We demonstrate that, as envisioned by
+Begelman, the hoop stress declines and the initial gas pressure excess near the
+axis decreases. The magnetization parameter \sigma, the ratio of the Poynting
+to the kinetic energy flux, declines from an initial value of 0.3 to about 0.01
+when the CD kink instability saturates. Our simulations demonstrate that
+axisymmetric models strongly overestimate the elongation of the pulsar wind
+nebulae. Therefore, the previous requirement for an extremely low pulsar wind
+magnetization can be abandoned. The observed structure of the pulsar wind
+nebulae do not contradict the natural assumption that the magnetic energy flux
+still remains a good fraction of the total energy flux after dissipation of
+alternating fields.",1012.2770v1
+2011-01-11,Solving relativistic hydrodynamic equation in presence of magnetic field for phase transition in a neutron star,"Hadronic to quark matter phase transition may occur inside neutron stars (NS)
+having central densities of the order of 3-10 times normal nuclear matter
+saturation density ($n_0$). The transition is expected to be a two-step
+process; transition from hadronic to 2-flavour matter and two-flavour to
+$\beta$ equilibrated charge neutral three-flavour matter. In this paper we
+concentrate on the first step process and solve the relativistic hydrodynamic
+equations for the conversion front in presence of high magnetic field. Lorentz
+force due to magnetic field is included in the energy momentum tensor by
+averaging over the polar angles. We find that for an initial dipole
+configuration of the magnetic field with a sufficiently high value at the
+surface, velocity of the front increases considerably.",1101.2030v3
+2011-02-13,Kagome Approximation for 3He on Husimi Lattice with Two- and Three-Site Exchange Interactions,"The Ising approximation of the Heisenberg model in a strong magnetic field,
+with two-, and three-spin exchange interactions are studied on a Husimi
+lattice. This model can be considered as an approximation of the third layer of
+3He absorbed on the surface of graphite (kagome lattice). Using dynamic
+approach we have found exact recursion relation for the partition function. For
+different values of exchange parameters and temperature the diagrams of
+magnetization are plotted and showed that magnetization properties of the model
+vary from ferromagnetic to antiferromagnetic depending from the value of model
+parameters. For antiferromagnetic case magnetization plateau at 1/3 of
+saturation field is obtained. Lyapunov exponent for recursion relation are
+considered and showed absents of bifurcation points in thermodynamic limit. The
+Yang-Lee zeros are analyzed in terms of neutral fixed points and showed that
+Yang-Lee zeros of the model are located on the arcs of the circle with the
+radius R=1.",1102.2607v1
+2011-04-28,Buneman instability in a magnetized current-carrying plasma with velocity shear,"Buneman instability is often driven in magnetic reconnection. Understanding
+how velocity shear in the beams driving the Buneman instability affects the
+growth and saturation of waves is relevant to turbulence, heating, and
+diffusion in magnetic reconnection. Using a Mathieu-equation analysis for weak
+cosine velocity shear together with Vlasov simulations, the effects of shear on
+the kinetic Buneman instability are studied in a plasma consisting of strongly
+magnetized electrons and cold unmagnetized ions. In the linearly unstable
+phase, shear enhances the coupling between oblique waves and the sheared
+electron beam, resulting in a wider range of unstable eigenmodes with common
+lower growth rates. The wave couplings generate new features of the electric
+fields in space, which can persist into the nonlinear phase when electron holes
+form. Lower hybrid instabilities simultaneously occur at
+$k_{\shortparallel}/k_{\perp} \sim \sqrt{m_e/m_i}$ with a much lower growth
+rate, and are not affected by the velocity shear.",1104.5283v2
+2011-06-07,Effect of Zn substitution on morphology and magnetic properties of copper ferrite nanofibers,"Spinel ferrite Cu1-xZnxFe2O4 nanofibers over a compositional range 0 < x < 1
+were prepared by electrospinning combined with sol-gel method. The influence of
+Zn2+ ions substitution on morphology, structure, and magnetic properties of
+copper ferrite has been investigated. The results show that surface of CuFe2O4
+nanofibers consists of small open porosity, while surface of doped nanofibers
+reveals smooth and densified nature. With increasing Zn substitution,
+saturation magnetization initially increases and then decreases with a maximum
+value of 58.4 emu/g at x = 0.4, coercivity and square ratio all decrease. The
+influence of substitution on magnetic properties is related with the cation
+distraction and exchange interactions between spinel lattices.",1106.1269v1
+2011-06-17,Magnetic susceptibility of Ce: an LDA+DMFT study,"The magnetic properties of Ce in the $\alpha$ and $\gamma$ phase are
+calculated within the LDA+DMFT approach. The magnetic susceptibility in these
+two phases shows a similar behavior over a wide temperature range: a
+Curie-Weiss law at high temperatures, indicating the presence of local moments,
+followed by a maximum in a crossover regime, and a saturation characteristic of
+a state with screened local moments at low temperature. The difference in
+experimentally observable magnetic properties is caused by the shift of the
+susceptibility to higher temperatures in the $\alpha-$phase compared to the
+$\gamma-$phase, due to the larger hybridization between localized $4f-$states
+and conductive $spd-$electrons.",1106.3470v2
+2011-06-24,Hydrogen-induced ferromagnetism in ZnO single crystals investigated by Magnetotransport,"We investigated the electrical and magnetic properties of low-energy
+hydrogen-implanted ZnO single crystals with hydrogen concentrations up to 3
+at.% in the first 20 nm surface layer between 10 K and 300 K. All samples
+showed clear ferromagnetic hysteresis loops at 300 K with a saturation
+magnetization up to 4 emu/g. The measured anomalous Hall effect agrees with the
+hysteresis loops measured by superconducting quantum interferometer device
+magnetometry. All the H-treated ZnO crystals exhibited a negative
+magnetoresistance up to the room temperature. The relative magnitude of the
+anisotropic magnetoresistance reaches 0.4 % at 250 K and 2 % at 10 K,
+exhibiting an anomalous, non-monotonous behavior and a change of sign below 100
+K. All the experimental data indicate that hydrogen atoms alone in a few
+percent range trigger a magnetic order in a ZnO crystalline state. Hydrogen
+implantation turns out to be a simpler and effective method to generate a
+magnetic order in ZnO, which provides interesting possibilities for future
+applications due to the strong reduction of the electrical resistance.",1106.4951v1
+2011-07-12,Magnetic and electric dipole moments of the $H\ {}^3Δ_1$ state in ThO,"The metastable $H \ {}^3\Delta_1$ state in the thorium monoxide (ThO)
+molecule is highly sensitive to the presence of a CP-violating permanent
+electric dipole moment of the electron (eEDM). The magnetic dipole moment
+$\mu_H$ and the molecule-fixed electric dipole moment $D_H$ of this state are
+measured in preparation for a search for the eEDM. The small magnetic moment
+$\mu_H = 8.5(5) \times 10^{-3} \ \mu_B$ displays the predicted cancellation of
+spin and orbital contributions in a ${}^3 \Delta_1$ paramagnetic molecular
+state, providing a significant advantage for the suppression of magnetic field
+noise and related systematic effects in the eEDM search. In addition, the
+induced electric dipole moment is shown to be fully saturated in very modest
+electric fields ($<$ 10 V/cm). This feature is favorable for the suppression of
+many other potential systematic errors in the ThO eEDM search experiment.",1107.2287v1
+2011-07-29,Ferrimagnetism and spontaneous ordering of transition-metals in La2CrFeO6 double-perovskite films,"We report on atomic ordering of B-site transition-metals and magnetic
+properties of epitaxial La2CrFeO6 double-perovskite films grown by pulsed-laser
+deposition under various conditions. The highest ordered sample exhibited a
+fraction of antisite-disorder of only 0.05 and a saturation magnetization of
+~2\mu_{B} per formula unit at 5 K. The result is consistent with the
+antiferromagnetic ordering of local spin moment
+(3d^{3}_{\downarrow}3d^{5}_{\uparrow}; S = -3/2+5/2 = 1). Therefore, the
+magnetic ground state of La2CrFeO6 double-perovskite that has been long debate
+is unambiguously revealed to be ferrimagnetic. Our results present a wide
+opportunity to explore novel magnetic properties of binary transition-metal
+perovskites upon epitaxial stabilization of the ordered phase.",1107.5891v1
+2011-09-14,Antiferromagnetic coupling across silicon regulated by tunneling currents,"We report on the enhancement of antiferromagnetic coupling in epitaxial
+Fe/Si/Fe structures by voltage-driven spin-polarized tunneling currents. Using
+the ballistic electron magnetic microscopy we established that the hot-electron
+collector current reflects magnetization alignment and the magnetocurrent
+exceeds 200% at room temperature. The saturation magnetic field for collector
+current corresponding to parallel alignment of magnetizations rises up with the
+tunneling current, thus demonstrating stabilization of the antiparallel
+alignment and increasing antiferromagnetic coupling. We connect the enhancement
+of antiferromagnetic coupling with local dynamic spin torques mediated by
+tunneling electrons",1109.3106v1
+2012-01-04,Quasiparticles of string solutions in the spin-1/2 antiferromagnetic Heisenberg chain in a magnetic field,"Spectral properties of the spin-1/2 antiferromagnetic Heisenberg chain in a
+magnetic field are investigated by using exact Bethe-ansatz solutions. We argue
+that not only quasiparticles called psinon and antipsinon but also a
+quasiparticle representing a 2-string in the Bethe ansatz plays an important
+role for dynamical properties in a magnetic field. Combined with psinon and
+antipsinon, the quasiparticle for a 2-string forms a continuum in the
+high-energy regime for transverse dynamical structure factor
+$S^{+-}(k,\omega)$. In the zero-field limit, the continuum is located on the
+mode of the lowest excited states in zero field called the des
+Cloizeaux-Pearson mode. In a magnetic field, the continuum separates from other
+low-energy continua, and reduces to the mode of bound states of overturned
+spins from the fully polarized state near the saturation field. We confirm the
+relevance through comparisons with available experimental results on the
+quasi-one-dimensional antiferromagnet CuCl$_2\cdot$2N(C$_5$D$_5$).",1201.0844v1
+2012-08-15,Current-induced synchronized switching of magnetization,"We investigate current-induced magnetization switching for a multilayer
+structure that allows a reduced switching current while maintaining high
+thermal stability of the magnetization. The structure consists of a
+perpendicular polarizer, a perpendicular free-layer, and an additional
+free-layer having in-plane magnetization. When the current runs perpendicular
+to the structure, the in-plane free-layer undergoes a precession and supplies
+an internal rf field to the perpendicular free-layer, resulting in a reduced
+switching current for one current polarity. For the other polarity, the
+in-plane free-layer almost saturates perpendicular to the plane and acts as
+another perpendicular polarizer, which also reduces the switching current.",1208.3050v1
+2012-09-12,Spin configurations in Co2FeAl0.4Si0.6 Heusler alloy thin film elements,"We determine experimentally the spin structure of half-metallic
+Co2FeAl0.4Si0.6 Heusler alloy elements using magnetic microscopy. Following
+magnetic saturation, the dominant magnetic states consist of quasi-uniform
+configurations, where a strong influence from the magnetocrystalline anisotropy
+is visible. Heating experiments show the stability of the spin configuration of
+domain walls in confined geometries up to 800 K. The switching temperature for
+the transition from transverse to vortex walls in ring elements is found to
+increase with ring width, an effect attributed to structural changes and
+consequent changes in magnetic anisotropy, which start to occur in the narrower
+elements at lower temperatures.",1209.2702v1
+2012-09-24,Theory of magnetic enhancement in strontium hexaferrite through Zn-Sn pair substitution,"We study the site occupancy and magnetic properties of Zn-Sn substituted
+M-type Sr-hexaferrite SrFe$_{12-x}$(Zn$_{0.5}$Sn$_{0.5}$)$_x$O$_{19}$ with x =
+1 using first-principles total-energy calculations. We find that in a
+ground-state configuration Zn-Sn ions preferentially occupy $4f_1$ and $4f_2$
+sites unlike the model previously suggested by Ghasemi et al. [J. Appl. Phys,
+\textbf{107}, 09A734 (2010)], where Zn$^{2+}$ and Sn$^{4+}$ ions occupy the
+$2b$ and $4f_2$ sites. Density-functional theory calculations show that our
+model has a lower total energy by more than 0.2 eV per unit cell compared to
+Ghasemi's model. More importantly, the latter does not show an increase in
+saturation magnetization ($M_s$) compared to the pure $M$-type Sr-hexaferrite,
+in disagreement with the experiment. On the other hand, our model correctly
+predicts a rapid increase in $M_s$ as well as a decrease in magnetic anisotropy
+compared to the pure $M$-type Sr-hexaferrite, consistent with experimental
+measurements.",1209.5143v2
+2012-10-16,High temperature magnetic insulating phase in ultrathin La0.67Sr0.33MnO3 films,"We present a study of the thickness dependence of magnetism and electrical
+conductivity in ultra thin La0.67Sr0.33MnO3 films grown on SrTiO3 (110)
+substrates. We found a critical thickness of 10 unit cells below which the
+conductivity of the films disappeared and simultaneously the Curie temperature
+(TC) increased, indicating a magnetic insulating phase at room temperature.
+These samples have a TC of about 560 K with a significant saturation
+magnetization of 1.2 +- 0.2 muB/Mn. The canted antiferromagnetic insulating
+phase in ultra thin films of n< 10 coincides with the occurrence of a higher
+symmetry structural phase with a different oxygen octahedra rotation pattern.
+Such a strain engineered phase is an interesting candidate for an insulating
+tunneling barrier in room temperature spin polarized tunneling devices.",1210.4435v1
+2012-11-11,Perpendicularly magnetized Mn-Co-Ga-based thin films with high coercive field,"Mn$_{3-x}$Co$_{x}$Ga epitaxial thin films were grown on MgO substrates by
+magnetron co-sputtering. Structures were tetragonal or cubic depending on Co
+content. Composition dependence of saturation magnetization and uniaxial
+magnetic anisotropy $K_u$ of the films were investigated. A high $K_u$ (1.2 MJ
+m$^{-3}$) was achieved for the Mn$_{2.6}$Co$_{0.3}$Ga$_{1.1}$ film with the
+magnetic moment 0.84$\mu_B$. Valence band spectra were obtained by hard X-ray
+photoelectron spectroscopy. Sharp peaks in the cubic case, which were absent in
+the tetragonal case, prove that a van Hove singularity causes a band
+Jahn-Teller effect with tetragonal distortion. Observations agree well with the
+first-principles calculations.",1211.2440v1
+2013-01-02,Fast collisionless reconnection and electron heating in strongly magnetized plasmas,"Magnetic reconnection in strongly magnetized (low-beta), weakly collisional
+plasmas is investigated using a novel fluid-kinetic model [Zocco &
+Schekochihin, Phys. Plasmas 18, 102309 (2011)] which retains non-isothermal
+electron kinetics. It is shown that electron heating via Landau damping (linear
+phase mixing) is the dominant dissipation mechanism. In time, electron heating
+occurs after the peak of the reconnection rate; in space, it is concentrated
+along the separatrices of the magnetic island. For sufficiently large systems,
+the peak reconnection rate is $cE_{max}\approx 0.2v_AB_{y,0}$, where $v_A$ is
+the Alfv\'en speed based on the reconnecting field $B_{y,0}$. The island
+saturation width is the same as in MHD models except for small systems, when it
+becomes comparable to the kinetic scales.",1301.0338v1
+2013-02-03,Effects of Strong Interactions in a Half Metallic Magnet: a Determinant Quantum Monte Carlo Study,"Understanding the effects of electron-electron interactions in half metallic
+magnets (HMs), which have band structures with one gapped spin channel and one
+metallic channel, poses fundamental theoretical issues as well as having
+importance for their potential applications. Here we use determinant quantum
+Monte Carlo to study the impacts of an on-site Hubbard interaction $U$, finite
+temperature, and an external (Zeeman) magnetic field on a bilayer tight-binding
+model which is a half-metal in the absence of interactions, by calculating the
+spectral density, conductivity, spin polarization of carriers, and local
+magnetic properties. We quantify the effect of $U$ on the degree of thermal
+depolarization, and follow relative band shifts and monitor when significant
+gap states appear, each of which can degrade the HM character. For this model,
+Zeeman coupling induces, at fixed particle number, two successive transitions:
+compensated half-metal with spin-down band gap $\rightarrow$ metallic
+ferromagnet $\rightarrow$ saturated ferromagnetic insulator. However, over much
+of the more relevant parameter regime, the half-metallic properties are rather
+robust to $U$.",1302.0550v1
+2013-02-26,R-M interactions in R2BaMO5 (R=Y or Gd and M=Cu or Zn),"R2BaMO5 (R = Gd, Y and M = Cu, Zn) oxides have been studied by specific heat,
+dc magnetic susceptibility, and electron paramagnetic resonance (EPR). For one
+member of the series without magnetic moment at M, namely Gd2BaZnO5,
+measurements reveal long range antiferromagnetic order at TN(Gd2BaZnO5) =
+2.3(0.1)K, much lower than the Curie Weiss temperature of {\Theta}=15.9(0.3)K.
+This indicates the existence of competing interactions that introduce a large
+degree of magnetic frustration in the system. For Y2BaCuO5 the Cu Cu
+interactions are responsible for the broad maximum in the magnetic contribution
+to the specific heat centered at 18.5(0.01)K that stretches beyond the
+instrumental limit of 25K. The strong Cu Cu interactions also present in
+Gd2BaCuO5, combined with the Gd-Cu interaction, polarize the Gd sublattice
+giving measurable contributions to the specific heat in the same temperature
+range. In addition, they broaden the Gd EPR line and saturate its integrated
+intensity. The ordering temperature of Gd ions is raised to
+TN(Gd2BaCuO5)=12.0(0.1)K.",1302.6327v1
+2013-05-03,Non-resonant magnetohydrodynamics streaming instability near magnetized relativistic shocks,"We present in this paper both a linear study and numerical relativistic MHD
+simulations of the non-resonant streaming instability occurring in the
+precursor of relativistic shocks. In the shock front restframe, we perform a
+linear analysis of this instability in a likely configuration for
+ultra-relativistic shock precursors. This considers magneto-acoustic waves
+having a wave vector perpendicular to the shock front and the large scale
+magnetic field. Our linear analysis is achieved without any assumption on the
+shock velocity and is thus valid for all velocity regimes. In order to check
+our calculation, we also perform relativistic MHD simulations describing the
+propagation of the aforementioned magneto-acoustic waves through the shock
+precursor. The numerical calculations confirm our linear analysis, which
+predicts that the growth rate of the instability is maximal for
+ultra-relativistic shocks and exhibits a wavenumber dependence $\propto
+k_x^{1/2}$. Our numerical simulations also depict the saturation regime of the
+instability where we show that the magnetic amplification is moderate but
+nevertheless significant ($\delta B/B\leq 10$). This latter fact may explain
+the presence of strong turbulence in the vicinity of relativistic magnetized
+shocks. Our numerical approach also introduces a convenient means to handle
+isothermal (ultra-)relativistic MHD conditions.",1305.0847v1
+2013-05-21,Contrasting behavior of the structural and magnetic properties in Mn- and Fe-doped In$_2$O$_3$ films,"We have observed room temperature ferromagnetism (FM) in In$_2$O$_3$ thin
+films doped with either 5 at.% Mn or Fe, prepared by pulsed laser deposition
+(PLD) at substrate temperatures ranging from 300 to 600$\,^{\circ}{\rm C}$. The
+dependence of saturation magnetization on grain size was investigated for both
+types of In$_2$O$_3$ films. It is revealed that, for the Mn-doped films, the
+magnetization was largest with small grains, indicating the importance of grain
+boundaries. In contrast, for Fe-doped films, the largest magnetization was
+observed with large grains.",1305.4831v1
+2013-10-04,Driven isotropic Heisenberg spin chain with arbitrary boundary twisting angle: exact results,"We consider an open isotropic Heisenberg quantum spin chain, coupled at the
+ends to boundary reservoirs polarized in different directions, which sets up a
+twisting gradient across the chain. Using a matrix product ansatz, we calculate
+the exact magnetization profiles and magnetization currents in the
+nonequilibrium steady steady state of a chain with N sites. The magnetization
+profiles are harmonic functions with a frequency proportional to the twisting
+angle {\theta}. The currents of the magnetization components lying in the
+twisting plane and in the orthogonal direction behave qualitatively
+differently: In-plane steady state currents scale as 1/N^2 for fixed and
+sufficiently large boundary coupling, and vanish as the coupling increases,
+while the transversal current increases with the coupling and saturates to
+2{\theta}/N.",1310.1315v2
+2014-02-18,Switching Properties in Magnetic Tunnel Junctions with Interfacial Perpendicular Anisotropy: Micromagnetic Study,"The role of universal memory can be successfully satisfied by magnetic tunnel
+junctions (MTJs) where the writing mechanism is based on spin-transfer torque
+(STT). An improvement in the switching properties (lower switching current
+density maintaining the thermal stability) has been achieved in MTJs with
+interfacial perpendicular anisotropy (IPA) at the interface between CoFeB and
+MgO. In this paper, micromagnetic simulations point out the influence of IPA
+and saturation magnetization (MS) on the properties of fast magnetization
+reversal achieved in 5, 10 and 20 ns. Both cases of in-plane and out-of-plane
+free layer are considered. In addition, the thermal effect is included for the
+in-plane switching at 20 ns and a complete analysis of energy dissipation
+during the switching is illustrated. This study can provide useful information
+for the design of STT-based memories.",1402.4352v1
+2014-03-20,Magnetization Process of the S=1/2 Heisenberg Antiferromagnet on the Cairo Pentagon Lattice,"We study the S=1/2 Heisenberg antiferromagnet on the Cairo pentagon lattice
+by the numerical-diagonalization method. We tune the ratio of two
+antiferromagnetic interactions coming from two kinds of inequivalent sites in
+this lattice, examining the magnetization process of the antiferromagnet;
+particular attention is given to one-third of the height of the saturation. We
+find that quantum phase transition occurs at a specific ratio and that a
+magnetization plateau appears in the vicinity of the transition. The plateau is
+accompanied by a magnetization jump on one side among the edges due to the
+spin-flop phenomenon. Which side the jump appears depends on the ratio.",1403.5008v1
+2014-04-02,Mechanical magnetometry of Cobalt nanospheres deposited by focused electron beam at the tip of ultra-soft cantilevers,"Using focused-electron-beam-induced deposition, Cobalt magnetic nanospheres
+with diameter ranging between 100 nm and 300 nm are grown at the tip of
+ultra-soft cantilevers. By monitoring the mechanical resonance frequency of the
+cantilever as a function of the applied magnetic field, the hysteresis curve of
+these individual nanospheres are measured. This enables to evaluate their
+saturation magnetization, found to be around 430 emu/cm^3 independently of the
+size of the particle, and to infer that the magnetic vortex state is the
+equilibrium configuration of these nanospheres at remanence.",1404.0492v1
+2014-04-03,Magnetic Field Tunable Small-scale Mechanical Properties of Nickel Single Crystals Measured by Nanoindentation Technique,"Nano- and micromagnetic materials have been extensively employed in
+micro-functional devices. However, measuring small-scale mechanical and
+magnetomechanical properties is challenging, which restricts the design of new
+products and the performance of smart devices. A new magnetomechanical
+nanoindentation technique is developed and tested on a nickel single crystal in
+the absence and presence of a saturated magnetic field. Small-scale parameters
+such as Young's modulus, indentation hardness, and plastic index are dependent
+on the applied magnetic field, which differ greatly from their macroscale
+counterparts. Possible mechanisms that induced 31% increase in modulus and 7%
+reduction in hardness (i.e., the flexomagnetic effect and the interaction
+between dislocations andmagnetic field, respectively) are analyzed and
+discussed. Results could be useful in the microminiaturization of applications,
+such as tunable mechanical resonators and magnetic field sensors.",1404.0884v1
+2014-07-05,Atomistic modeling of magnetization reversal modes in $L1_{0}$ FePt nanodots with magnetically soft edges,"Nanopatterned FePt nano-dots often exhibit low coercivity and a broad
+switching field distribution, which could arise due to edge damage during the
+patterning process causing a reduction in the $L1_{0}$ ordering required for a
+high magnetocrystalline anisotropy. Using an atomistic spin model, we study the
+magnetization reversal behavior of $L1_{0}$ FePt nanodots with soft magnetic
+edges. We show that reversal is initiated by nucleation for the whole range of
+edge widths studied. For narrow soft edges the individual nucleation events
+dominate reversal; for wider edges, multiple nucleation at the edge creates a
+circular domain wall at the interface which precedes complete reversal. Our
+simulations compare well with available analytical theories. The increased edge
+width further reduces and saturates the required nucleation field. The
+nucleation field and the activation volume manipulate the thermally induced
+switching field distribution. By control of the properties of dot edges using
+proper patterning methods, it should be possible to realize exchange spring bit
+patterned media without additional soft layers.",1407.1363v2
+2014-07-17,Nonlinear mirror instability,"Slow dynamical changes in magnetic-field strength and invariance of the
+particles' magnetic moments generate ubiquitous pressure anisotropies in weakly
+collisional, magnetized astrophysical plasmas. This renders them unstable to
+fast, small-scale mirror and firehose instabilities, which are capable of
+exerting feedback on the macroscale dynamics of the system. By way of a new
+asymptotic theory of the early nonlinear evolution of the mirror instability in
+a plasma subject to slow shearing or compression, we show that the instability
+does not saturate quasilinearly at a steady, low-amplitude level. Instead, the
+trapping of particles in small-scale mirrors leads to nonlinear secular growth
+of magnetic perturbations, $\delta B/B \propto t^{2/3}$. Our theory explains
+recent collisionless simulation results, provides a prediction of the mirror
+evolution in weakly collisional plasmas and establishes a foundation for a
+theory of nonlinear mirror dynamics with trapping, valid up to $\delta B/B
+=O(1)$.",1407.4707v1
+2014-07-23,Effect of Eu magnetism on the electronic properties of the candidate Dirac material EuMnBi2,"The crystal structure and physical properties of the layered material EuMnBi2
+have been characterized by measurements on single crystals. EuMnBi2 is
+isostructural with the Dirac material SrMnBi2 based on single crystal x-ray
+diffraction, crystallizing in the I4/mmm space group (No. 139). Magnetic
+susceptibility measurements suggest antiferromagnetic (AFM) ordering of moments
+on divalent Eu ions near T_N=22K. For low fields, the ordered Eu moments are
+aligned along the c-axis, and a spin-flop is observed near 5.4T at 5K. The
+moment is not saturated in an applied field of 13T at 5K, which is uncommon for
+compounds containing Eu^{2+}. The magnetic behavior suggests an anisotropy
+enhancement via interaction between Eu and the Mn moments that appear to be
+order antiferromagnetically below approximately 310K. A large increase in the
+magnetoresistance is observed across the spin-flop, with absolute
+magnetoresistance reaching approximately 650% at 5K and 12T. Hall effect
+measurements reveal a decrease in the carrier density below T_N, which implies
+a manipulation of the Fermi surface by magnetism on the sites surrounding the
+Bi square nets that lead to Dirac cones in this family of materials.",1407.6203v1
+2014-10-03,Unexpected impact of magnetic disorder on multiband superconductivity,"We analyze how the magnetic disorder affects the properties of the two-band
+$s_\pm$ and $s_{++}$ models, which are subject of hot discussions regarding
+iron-based superconductors and other multiband systems like MgB$_2$. We show
+that there are several cases when the transition temperature $T_c$ is not fully
+suppressed by magnetic impurities in contrast to the Abrikosov-Gor'kov theory,
+but a saturation of $T_c$ takes place in the regime of strong disorder. These
+cases are: (1) the purely interband impurity scattering, (2) the unitary
+scattering limit. We show that in the former case the $s_\pm$ gap is preserved,
+while the $s_{++}$ state transforms into the $s_\pm$ state with increasing
+magnetic disorder. For the case (2), the gap structure remains intact.",1410.0832v2
+2014-10-30,Magnetoresistance of layered conductors under conditions of topological phase transition,"The resistance of layered conductors with a multisheet Fermi surface (FS), in
+a high magnetic field, in the immediate vicinity of Lifshic's topological
+transition when the separate FS sheets are drown together by an external
+action, pressure in part (and eventual change of the FS connectivity) is
+studied theoretically. Analysis of magnetoresistance near topological
+transition is illustrated for the case of FS in the shape of lightly corrugated
+cylinder and two corrugated planes distributed with a repeated period in the
+pulse space. It yields, that as the FS plane sheets approach sufficiently the
+cylinder, the charge carriers produce a magnetic breakdown of one FS sheet to
+another, decreasing a sharp anisotropy of magnetoresistance to the in-plane
+current. Instead of square increase with a magnetic field, the slower
+resistance growth remains linear in the field within a broad magnetic-field
+range. In the intimate vicinity of topological transition, when the energy gap
+between FS layers is negligibly small, the resistance is saturated.",1410.8330v1
+2014-12-26,Topological Order Parameters of the Spin-1/2 Dimerized Heisenberg Ladder in Magnetic Field,"Topological properties of the spin-1/2 dimerized Heisenberg ladder are
+investigated focusing on the plateau phase in the magnetic field whose
+magnetization is half of the saturation value. Although the applied magnetic
+field removes most of the symmetries of the system, there is a symmetry
+protected topological phase supported by the spatial inversion symmetry. The
+Z_2 Berry phase associated with a symmetry respecting boundary and quantized
+into 0 and \pi is used as a symmetry protected topological order parameter.
+Edge states are also analyzed to confirm the bulk-edge correspondence. In
+addition, a symmetry breaking boundary is considered. Then, we observe a unique
+type of quantization of the Berry phase, a quantization into +-\pi/2 of the
+Berry phase. In this case, the bulk-edge correspondence is also unique, namely,
+there emerge ""polarized"" edge states for the case with +-\pi/2 quantization. We
+also evaluate the entanglement entropy by the infinite time-evolving block
+decimation (iTEBD) to complement the Berry phase based arguments. Further, a
+different type of the topological order parameter is extracted from the matrix
+product state representation of the ground state given by the iTEBD.",1412.7901v2
+2015-01-19,Direct measurements of the magnetocaloric effect in pulsed magnetic fields: The example of the Heusler alloy Ni$_{50}$Mn$_{35}$In$_{15}$,"We have studied the magnetocaloric effect (MCE) in the shape-memory Heusler
+alloy Ni$_{50}$Mn$_{35}$In$_{15}$ by direct measurements in pulsed magnetic
+fields up to 6 and 20 T. The results in 6 T are compared with data obtained
+from heat-capacity experiments. We find a saturation of the inverse MCE,
+related to the first-order martensitic transition, with a maximum adiabatic
+temperature change of $\Delta T_{ad} = -7$ K at 250 K and a conventional
+field-dependent MCE near the second-order ferromagnetic transition in the
+austenitic phase. The pulsed magnetic field data allow for an analysis of the
+temperature response of the sample to the magnetic field on a time scale of
+$\sim 10$ to 100 ms which is on the order of typical operation frequencies (10
+to 100 Hz) of magnetocaloric cooling devices. Our results disclose that in
+shape-memory alloys the different contributions to the MCE and hysteresis
+effects around the martensitic transition have to be carefully considered for
+future cooling applications.",1501.04430v1
+2015-02-20,Magnetic and Dielectric Properties of Multiferroic BiFeO3 Nanoparticles Synthesized by a Novel Citrate Combustion Method,"Single phase BiFeO3 nanoparticles have been successfully synthesized for the
+first time by a novel citrate combustion method without using any solvent. Well
+mixed metal nitrates along with citric acid which is used as fuel combust to
+give BiFeO3 nanoparticles after annealing. These particles are single phase in
+nature and crystallize in the rhombohedral distorted perovskite structure
+(space group-R3c) which has been confirmed by the Rietveld refinement of the
+room temperature powder x-ray diffraction data. Nearly spherical particles of
+average particle size 47 nm have been seen from transmission electron
+micrograph. Room temperature magnetic hysteresis measurement shows weak
+ferromagnetism though the magnetization does not saturate upto 1.75 T applied
+field. The coercive field value is calculated to be 180 Oe which is 3 times
+higher than that prepared by solvent free combustion method using Glycine. 57Fe
+M\""ossbauer spectrum can be fitted with a sextet corresponding to single
+magnetic state of hyperfine field about 49.5 T corresponding to Fe3+ state of
+the iron atom. The dielectric relaxation and ac conductivity as a function of
+frequency have been discussed. High dielectric permittivity has not been found
+in these nanoparticles like other reported BiFeO3 ceramics.",1502.05797v1
+2015-04-09,Low-field microwave absorption and magnetoresistance in iron nanostructures grown by electrodeposition on n-type lightly-doped silicon substrates,"In this study we investigate magnetic properties, surface morphology and
+crystal structure in iron nanoclusters electrodeposited on lightly-doped (100)
+n-type silicon substrates. Our goal is to investigate the spin injection and
+detection in the Fe/Si lateral structures. The samples obtained under electric
+percolation were characterized by magnetoresistive and magnetic resonance
+measurements with cycling the sweeping applied field in order to understand the
+spin dynamics in the as-produced samples. The observed hysteresis in the
+magnetic resonance spectra, plus the presence of a broad peak in the
+non-saturated regime confirming the low field microwave absorption (LFMA), were
+correlated to the peaks and slopes found in the magnetoresistance curves. The
+results suggest long range spin injection and detection in low resistive
+silicon and the magnetic resonance technique is herein introduced as a
+promising tool for analysis of electric contactless magnetoresistive samples.",1504.02508v1
+2015-05-28,Steady shear magnetorheology in Co0.9Ni0.1 nanocluster-based MR fluids at elevated temperatures,"In this paper, we present the study of magnetorheological properties of
+magnetic fluids containing Co0.9Ni0.1 nanocluster that have been measured as a
+function of both magnetic field and temperature. Co-rich nanoclusters were
+synthesized by conventional homogeneous nucleation in liquid polyol.
+Morphological characterization using FESEM revealed the non-aggregated nature
+of nanoclusters with an average diameter of 450 nm. Crystal structure and room
+temperature magnetization measurements were performed by powder XRD and
+vibrating sample magnetometry (VSM). Two MR samples of different particle
+volume fractions were prepared. Temperature-dependent steady shear MR
+characterizations for both the samples in the range of 250C-550C demonstrated
+systematic decline of MR parameters with increasing temperatures. The
+temperature-induced thinning of shear stress and viscosity was explained in
+terms of change in effective volume fraction and magnetic saturation. To
+analyze the measured variation in MR response with increasing temperature,
+suitable temperature-sensitive scaling parameters were also constructed.
+Finally to generalize the trend, rheological master curves were constructed by
+using time-temperature-field superposition method.",1505.07567v1
+2015-07-11,Coherent nonhelical shear dynamos driven by magnetic fluctuations at low Reynolds numbers,"Nonhelical shear dynamos are studied with a particular focus on the
+possibility of coherent dynamo action. The primary results -- serving as a
+follow up to the results of Squire & Bhattacharjee [arXiv:1506.04109 (2015)] --
+pertain to the ""magnetic shear-current effect"" as a viable mechanism to drive
+large-scale magnetic field generation. This effect raises the interesting
+possibility that the saturated state of the small-scale dynamo could drive
+large-scale dynamo action, and is likely to be important in the unstratified
+regions of accretion disk turbulence. In this paper, the effect is studied at
+low Reynolds numbers, removing the complications of small-scale dynamo
+excitation and aiding analysis by enabling the use of quasi-linear statistical
+simulation methods. In addition to the magnetically driven dynamo, new results
+on the kinematic nonhelical shear dynamo are presented. These illustrate the
+relationship between coherent and incoherent driving in such dynamos,
+demonstrating the importance of rotation in determining the relative dominance
+of each mechanism.",1507.03154v1
+2015-08-04,Acoustic signatures of the phases and phase transitions in Yb$_2$Ti$_2$O$_7$,"We report on measurements of the sound velocity and attenuation in a single
+crystal of the candidate quantum- spin-ice material Yb$_2$Ti$_2$O$_7$ as a
+function of temperature and magnetic field. The acoustic modes couple to the
+spins magneto-elastically and, hence, carry information about the spin
+correlations that sheds light on the intricate magnetic phase diagram of
+Yb$_2$Ti$_2$O$_7$ and the nature of spin dynamics in the material.
+Particularly, we find a pronounced thermal hysteresis in the acoustic data with
+a concomitant peak in the specific heat indicating a possible first-order phase
+transition at about $0.17$ K. At low temperatures, the acoustic response to
+magnetic field saturates hinting at the development of magnetic order.
+Furthermore, mean-field calculations suggest that Yb$_2$Ti$_2$O$_7$ undergoes a
+first-order phase transition from a cooperative paramagnetic phase to a
+ferromagnet below $T\approx 0.17$ K.",1508.00925v1
+2015-08-05,Inverse proximity effect at superconductor-ferromagnet interfaces: Evidence for induced triplet pairing in the superconductor,"Considerable evidence for proximity-induced triplet superconductivity on the
+ferromagnetic side of a superconductor-ferromagnet (S-F) interface now exists;
+however, the corresponding effect on the superconductor side has hardly been
+addressed. We have performed scanning tunneling spectroscopy measurements on
+NbN superconducting thin films proximity coupled to the half-metallic
+ferromagnet La2/3Ca1/3MnO3 (LCMO) as a function of magnetic field. We have
+found that at zero and low applied magnetic fields the tunneling spectra on NbN
+typically show an anomalous gap structure with suppressed coherence peaks and,
+in some cases, a zero-bias conductance peak. As the field increases to the
+magnetic saturation of LCMO where the magnetization is homogeneous, the spectra
+become more BCS-like and the critical temperature of the NbN increases,
+implying a reduced proximity effect. Our results therefore suggest that
+triplet-pairing correlations are also induced in the S side of an S-F bilayer.",1508.01070v1
+2015-08-28,Rigorous determination of the ground-state phases and thermodynamics in an Ising-type multiferroic Ca3CoMnO6 chain,"To understand the collinear-magnetism-driven ferroelectricity in multiferroic
+Ca3CoMnO6 compound, we have established an elastic diatomic Ising spin-chain
+model with axial-next-nearest-neighbor interaction to describe its
+magnetoelectric properties. By employing magneto-phonon decoupling and
+transfer-matrix method, the possible ground-state configurations and
+thermodynamic behaviors of the system have been exactly determined. From the
+perspective of the ground-state configuration, we analyze the computational
+results and make a detail comparison with experimental data. The parameter
+relation for the appearance of electric polarization has been discussed. Our
+data indicate that the magnetic coupling between nearest-neighbor spin pair is
+antiferromagnetic rather than ferromagnetic. The system under the driven of
+external magnetic field undergoes a different series of transitions from the
+up-up-down-down spin configuration to the up-down-up state with peculiar 1/3
+magnetization plateau, then to the up-up-up-down state, and finally saturated
+at up-up-up-up state.",1508.07072v1
+2015-09-02,Effect of Chemical Pressure on High Temperature Ferrimagnetic Double Perovskites Sr2CrOsO6 and Ca2CrOsO6,"The ordered double perovskites Sr2CrOsO6 and Ca2CrOsO6 have been synthesized
+and characterized with neutron powder diffraction, electrical transport
+measurements, and high field magnetization experiments. Sr2CrOsO6 and Ca2CrOsO6
+crystallize with R-3 and P21/n space group symmetry, respectively. Both
+materials are found to be ferrimagnetic insulators with saturation
+magnetizations near 0.2 {\mu}B. Sr2CrOsO6 orders at 660 K, showing
+non-monotonic magnetization temperature dependence, while Ca2CrOsO6 orders at
+490 K and does not show non-monotonic behavior. Evidence for a theoretically
+predicted canted magnetic structure in Sr2CrOsO6 is sought and not found.",1509.00901v1
+2015-09-13,Effects of Cr substitution on the magnetic and transport properties and electronic states of SrRuO3 epitaxial thin films,"The effect of Cr substitution in a SrRuO3 epitaxial thin film on SrTiO3
+substrate was investigated by measuring the magnetic and transport properties
+and the electronic states. The ferromagnetic transition temperature of the
+SrRu0.9Cr0.1O3 film (166 K) was higher than that of the SrRuO3 film (147 K).
+Resonant photoemission spectroscopy experimentally revealed that the Cr 3dt2g
+orbital is hybridized with the Ru 4dt2g orbital in the SrRu0.9Cr0.1O3 film,
+supporting the assumption that the enhancement of the ferromagnetic transition
+temperature through Cr substitution stems from the widening of energy bands due
+to the hybridization of Cr 3dt2g and Ru 4dt2g orbitals. Furthermore, we found
+that the Hall resistivity of the SrRu0.9Cr0.1O3 film at low temperature is not
+a linear function of magnetic field in the high-field region where the
+out-of-plane magnetization was saturated; this result suggests that the
+SrRu0.9Cr0.1O3 film undergoes a structural transition at low temperature
+accompanied with the modulation of the Fermi surface.",1509.03804v1
+2015-09-20,"Electronic structure, magnetism and antisite disorder in CoFeCrGe and CoMnCrAl quaternary Heusler alloys","We present a combined theoretical and experimental study of two quaternary
+Heusler alloys CoFeCrGe (CFCG) and CoMnCrAl (CMCA), promising candidates for
+spintronics applications. Magnetization measurement shows the saturation
+magnetization and transition temperature to be $3\; \mu_B$, $866$ K and $0.9 \;
+\mu_B$, $358$ K for CFCG and CMCA respectively. The magnetization values agree
+fairly well with our theoretical results and also obey the Slater-Pauling rule,
+a prerequisite for half metallicity. A striking difference between the two
+systems is their structure; CFCG crystallizes in fully ordered Y-type structure
+while CMCA has L2$_1$ disordered structure. The antisite disorder adds a
+somewhat unique property to the second compound, which arises due to the
+probabilistic mutual exchange of Al positions with Cr/Mn and such an effect is
+possibly expected due to comparable electronegativities of Al and Cr/Mn. {\it
+Ab-initio} simulation predicted a unique transition from half metallic
+ferromagnet to metallic antiferromagnet beyond a critical excess amount of Al
+in the alloy.",1509.05971v2
+2015-09-30,Efficient magnetic-field amplification due to the Kelvin-Helmholtz instability in binary neutron star mergers,"We explore magnetic-field amplification due to the Kelvin-Helmholtz
+instability during binary neutron star mergers. By performing high-resolution
+general relativistic magnetohydrodynamics simulations with a resolution of
+$17.5$ m for $4$--$5$ ms after the onset of the merger on the Japanese
+supercomputer ""K"", we find that an initial magnetic field of moderate maximum
+strength $10^{13}$ G is amplified at least by a factor of $\approx 10^3$. We
+also explore the saturation of the magnetic-field energy and our result shows
+that it is likely to be $\gtrsim 4 \times 10^{50}$ erg, which is $\gtrsim
+0.1\%$ of the bulk kinetic energy of the merging binary neutron stars.",1509.09205v2
+2016-02-26,Water dispersible CoFe2O4 nanoparticles with improved colloidal stability for biomedical applications,"Single phase cobalt ferrite (CoFe2O4, CFO) nanoparticles of a controlled size
+(~ 6 nm) exhibiting superparamagnetic properties have been synthesized by
+hydrothermal technique using oleic acid (OA) as surfactant. The oleic acid
+coated CFO nanoparticles are stable in non-polar organic media, such as hexane
+but are not well dispersible in water. The surface of these snanoparticles has
+been further modified by citric acid using ligand exchange process, which makes
+CFO nanoparticles more stable colloidal solution in water. Citric acid coated
+CFO nanoparticles exhibits high dispersibility in water, high zeta potential,
+very low coercivity and moderate saturation magnetization. Biocompatibility of
+these CFO nanoparticles is demonstrated through cytotoxicity test in L929 cell
+line.",1602.08415v1
+2016-03-15,Colossal Magnetocapacitance Effect and Multiferroism of Polycrystalline La0.2Pb0.7Fe12O19,"The mutual control of the electric and magnetic properties of a multiferroic
+solid is of fundamental and great technological importance. We report here on
+the colossal magnetoelectric coupling effect of polycrystalline
+La0.2Pb0.7Fe12O19. A large classic ferroelectric hysteresis loop with full
+saturation and a strong magnetic hysteresis loop were observed simultaneously
+in polycrystalline La0.2Pb0.7Fe12O19 due to the coexistence of an off-centered
+FeO6 octahedron in its unit cell and electron spins in the partially filled 3d
+orbits of the Fe3+ ions. The coupling voltage and capacity demonstrate giant
+oscillations, along with magnetic field; the maximum magnetocapacitance ratio
+exceeds 1.9E5 at 80 Hz. The substitution of La ions with Pb ions progressively
+stabilized the conical spin structure, which gave rise to the spin-current
+induced capacity oscillations upon magnetic field.",1603.04508v1
+2016-06-02,The small-scale turbulent dynamo in smoothed particle magnetohydrodynamics,"Supersonic turbulence is believed to be at the heart of star formation. We
+have performed smoothed particle magnetohydrodynamics (SPMHD) simulations of
+the small-scale dynamo amplification of magnetic fields in supersonic
+turbulence. The calculations use isothermal gas driven at rms velocity of Mach
+10 so that conditions are representative of star-forming molecular clouds in
+the Milky Way. The growth of magnetic energy is followed for 10 orders in
+magnitude until it reaches saturation, a few percent of the kinetic energy. The
+results of our dynamo calculations are compared with results from grid-based
+methods, finding excellent agreement on their statistics and their qualitative
+behaviour. The simulations utilise the latest algorithmic developments we have
+developed, in particular, a new divergence cleaning approach to maintain the
+solenoidal constraint on the magnetic field and a method to reduce the
+numerical dissipation of the magnetic shock capturing scheme. We demonstrate
+that our divergence cleaning method may be used to achieve $\nabla \cdot {\bf
+B}=0$ to machine precision, albeit at significant computational expense.",1606.00767v1
+2016-08-22,Optimization of infrared and magnetic shielding of superconducting TiN and Al coplanar microwave resonators,"We present a systematic study of the effects of shielding on the internal
+quality factors (Qi) of Al and TiN microwave resonators designed for use in
+quantum coherent circuits. Measurements were performed in an adiabatic
+demagnetization refrigerator, where typical magnetic fields of 200 {\mu}T are
+present at the unshielded sample stage. Radiation shielding consisted of 100 mK
+and 500 mK Cu cans coated with infrared absorbing epoxy. Magnetic shields
+consisted of Cryoperm 10 and Sn plating of the Cu cans. A 2.7 K radiation can
+and coaxial thermalization filters were present in all measurements. TiN
+samples with Qi = $1.3*10^6$ at 100 mK exhibited no significant variation in
+quality factor when tested with limited shielding. In contrast, Al resonators
+showed improved Qi with successive shielding, with the largest gains obtained
+from the addition of the first radiation and magnetic shields and saturating
+before the addition of Sn plating infrared absorbing epoxy.",1608.06273v1
+2016-09-20,A coupled spin-electron diamond chain with different Landé g-factors of localized Ising spins and mobile electrons,"A coupled spin-electron diamond chain with localized Ising spins placed on
+its nodal sites and mobile electrons delocalized over interstitial sites is
+explored in a magnetic field taking into account the difference between Land\'e
+g-factors of the localized spins and mobile electrons. The ground-state phase
+diagram is constituted by two classical ferrimagnetic phases, the quantum
+unsaturated paramagnetic phase and the saturated paramagnetic phase. Both
+classical ferrimagnetic phases as well as the unsaturated paramagnetic phase
+are reflected in a low-temperature magnetization curve as intermediate
+magnetization plateaus. The unsaturated paramagnetic phase is quantum in its
+character as evidenced by the fermionic concurrence calculated for a pair of
+the mobile electrons hopping in between the interstitial sites. It is shown
+that the magnetic field can under certain conditions induce a quantum
+entanglement above the disentangled ground state.",1609.06072v2
+2016-09-21,Evolution of the magnetorotational instability on initially tangled magnetic fields,"The initial magnetic field of previous magnetorotational instability (MRI)
+simulations has always included a significant system-scale component, even if
+stochastic. However, it is of conceptual and practical interest to assess
+whether the MRI can grow when the initial field is turbulent. The ubiquitous
+presence of turbulent or random flows in astrophysical plasmas generically
+leads to a small-scale dynamo (SSD), which would provide initial seed turbulent
+velocity and magnetic fields in the plasma that becomes an accretion disc. Can
+the MRI grow from these more realistic initial conditions? To address this we
+supply a standard shearing box with isotropically forced SSD generated magnetic
+and velocity fields as initial conditions, and remove the forcing. We find that
+if the initially supplied fields are too weak or too incoherent, they decay
+from the initial turbulent cascade faster than they can grow via the MRI. When
+the initially supplied fields are sufficient to allow MRI growth and
+sustenance, the saturated stresses, large-scale fields, and power spectra match
+those of the standard zero net flux MRI simulation with an initial large scale
+vertical field.",1609.06745v2
+2016-09-30,The Tricritical Point of the f-electron Antiferromagnet USb2 Driven by High Magnetic Fields,"In pulsed magnetic fields up to 65T and at temperatures below the N\'eel
+transition, our magnetization and magnetostriction measurements reveal a
+field-induced metamagnetic-like transition that is suggestive of an
+antiferromagnetic to polarized paramagnetic or ferrimagnetic ordering. Our data
+also suggests a change in the nature of this metamagnetic-like transition from
+second- to first-order-like near a tricritical point at T_{tc} ~145K and
+H_{c}~52T. At high fields for H>H_{c} we found a decreased magnetic moment
+roughly half of the moment reported in low field measurements. We propose that
+\mathit{f-p} hybridization effects and magnetoelastic interactions drive the
+decreased moment, lack of saturation at high fields, and the decreased phase
+boundary.",1609.09845v1
+2016-11-08,Thermal and Magnetic Properties of Nanostructured Ferrimagnetic Composites with Graphene - Graphite Fillers,"We report the results of an experimental study of thermal and magnetic
+properties of nanostructured ferrimagnetic iron oxide composites with graphene
+and graphite fillers synthesized via the current activated pressure assisted
+densification. The thermal conductivity was measured using the laser-flash and
+transient plane source techniques. It was demonstrated that addition of 5 wt. %
+of equal mixture of graphene and graphite flakes to the composite results in a
+factor of x2.6 enhancement of the thermal conductivity without significant
+degradation of the saturation magnetization. The microscopy and spectroscopic
+characterization reveal that sp2 carbon fillers preserve their crystal
+structure and morphology during the composite processing. The strong increase
+in the thermal conductivity was attributed to the excellent phonon heat
+conduction properties of graphene and graphite. The results are important for
+energy and electronic applications of the nanostructured permanent magnets.",1611.02359v1
+2017-01-16,Electric field modulation of the non-linear areal magnetic anisotropy energy,"We study the ferromagnetic layer thickness dependence of the
+voltage-controlled magnetic anisotropy (VCMA) in gated CoFeB/MgO
+heterostructures with heavy metal underlayers. When the effective CoFeB
+thickness is below ~1 nm, the VCMA efficiency of Ta/CoFeB/MgO heterostructures
+considerably decreases with decreasing CoFeB thickness. We find that a high
+order phenomenological term used to describe the thickness dependence of the
+areal magnetic anisotropy energy can also account for the change in the areal
+VCMA efficiency. In this structure, the higher order term competes against the
+common interfacial VCMA, thereby reducing the efficiency at lower CoFeB
+thickness. The areal VCMA efficiency does not saturate even when the effective
+CoFeB thickness exceeds ~1 nm. We consider the higher order term is related to
+the strain that develops at the CoFeB/MgO interface: as the average strain of
+the CoFeB layer changes with its thickness, the electronic structure of the
+CoFeB/MgO interface varies leading to changes in areal magnetic anisotropy
+energy and VCMA efficiency.",1701.04150v1
+2017-02-19,Highly magnetized neutron stars in a many-body forces formalism,"In this work, we study the effects of different magnetic field configurations
+in neutron stars described by a many-body forces formalism (MBF model). The MBF
+model is a relativistic mean field formalism that takes into account many-body
+forces by means of a meson field dependence of the nuclear interaction coupling
+constants. We choose the best parametrization of the model that reproduces
+nuclear matter properties at saturation and also describes massive neutron
+stars. We assume matter to be in beta-equilibrium, charge neutral and at zero
+temperature. Magnetic fields are taken into account both in the equation of
+state and in the structure of the stars by the self-consistent solution of the
+Einstein-Maxwell equations. We assume a poloidal magnetic field distribution
+and calculate its effects on neutron stars, showing its influence on the
+gravitational mass and deformation of the stars.",1702.05685v1
+2017-04-11,CoFeAlB alloy with low damping and low magnetization for spin transfer torque switching,"We investigate the effect of Al doping on the magnetic properties of the
+alloy CoFeB. Comparative measurements of the saturation magnetization, the
+Gilbert damping parameter $\alpha$ and the exchange constant as a function of
+the annealing temperature for CoFeB and CoFeAlB thin films are presented. Our
+results reveal a strong reduction of the magnetization for CoFeAlB in
+comparison to CoFeB. If the prepared CoFeAlB films are amorphous, the damping
+parameter $\alpha$ is unaffected by the Al doping in comparison to the CoFeB
+alloy. In contrast, in the case of a crystalline CoFeAlB film, $\alpha$ is
+found to be reduced. Furthermore, the x-ray characterization and the evolution
+of the exchange constant with the annealing temperature indicate a similar
+crystallization process in both alloys. The data proves the suitability of
+CoFeAlB for spin torque switching properties where a reduction of the switching
+current in comparison with CoFeB is expected.",1704.03326v1
+2017-05-29,"Contributions of Co and Fe orbitals to Perpendicular Magnetic Anisotropy of MgO/CoFeB Bilayers with Spin-Orbit-Torque-Related (Ta, W, IrMn, and Ti) Underlayers","We study the perpendicular magnetic anisotropy (PMA) of the CoFeB/MgO
+bilayers in contact with W, Ta, IrMn and Ti which has been suggested as the
+spin-orbit-torque-related underlayers. The saturation magnetization of the
+CoFeB depends on the underlayer materials due to formation of a dead-layer,
+affecting PMA strength of each film. The x-ray magnetic circular dichroism
+measurement reveals that the interfacial intermixing suppresses only the
+perpendicular orbital moment of Fe, while the intermixing simultaneously
+suppresses both the perpendicular and in-plane orbital moments of Co.",1705.10064v1
+2017-06-24,Magnetization process of the S = 1/2 two-leg organic spin-ladder compound BIP-BNO,"We have measured the magnetization of the organic compound BIP-BNO
+(3,5'-bis(N-tert-butylaminoxyl)-3',5-dibromobiphenyl) up to 76 T where the
+magnetization is saturated. The S = 1/2 antiferromagnetic Heisenberg two-leg
+spin-ladder model accounts for the obtained experimental data regarding the
+magnetization curve, which is clarified using the quantum Monte Carlo method.
+The exchange constants on the rung and the side rail of the ladder are
+estimated to be J(rung)/kB = 65.7 K and J(leg)/kB = 14.1 K, respectively,
+deeply in the strong coupling region: J(rung)/J(leg) > 1.",1706.08008v1
+2017-06-28,Monte Carlo study of magnetic nanoparticles adsorbed on halloysite $Al_2Si_2O_5(OH)_4$ nanotubes,"We study properties of magnetic nanoparticles adsorbed on the halloysite
+surface. For that a distinct magnetic Hamiltonian with random distribution of
+spins on a cylindrical surface was solved by using a nonequilibrium Monte Carlo
+method. The parameters for our simulations: anisotropy constant, nanoparticle
+size distribution, saturated magnetization and geometrical parameters of the
+halloysite template were taken from recent experiments. We calculate the
+hysteresis loops and temperature dependence of the zero field cooling (ZFC)
+susceptibility, which maximum determines the blocking temperature. It is shown
+that the dipole-dipole interaction between nanoparticles moderately increases
+the blocking temperature and weakly increases the coercive force. The obtained
+hysteresis loops (e.g., the value of the coercive force) for Ni nanoparticles
+are in reasonable agreement with the experimental data. We also discuss the
+sensitivity of the hysteresis loops and ZFC susceptibilities to the change of
+anisotropy and dipole-dipole interaction, as well as the 3d-shell occupation of
+the metallic nanoparticles; in particular we predict larger coercive force for
+Fe, than for Ni nanoparticles.",1706.09213v2
+2017-07-05,Indications of spin polarized transport in Ba$_2$FeMoO$_6$ thin films,"We have investigated the magnetic and magnetotransport properties of
+Ba$_2$FeMoO$_6$ thin films produced by pulsed laser deposition from optimized
+bulk material. The films are comprised of grains of crystalline Ba$_2$FeMoO$_6$
+with a disordered grain boundary region that lowers the net saturation
+magnetization of the film and prevents full magnetic alignment below a Curie
+temperature $T_C$$\sim$305 K. Magnetotransport measurements point to the
+Ba$_2$FeMoO$_6$ grains retaining the high spin polarization of a half-metal up
+to $T_C$, while the grain boundaries greatly reduce the spin polarization of
+the intergrain electrical current due to spin-flip scattering. Our results show
+that a strong spin polarization of the electronic charge carriers is present
+even in Ba$_2$FeMoO$_6$ films that do not show the ideal bulk magnetic
+character.",1707.01208v1
+2017-09-21,Tricritical point and phase diagram based on critical scaling in monoaxial chiral helimagnet Cr1/3NbS2,"In this work, the magnetism of the single crystal Cr$_{1/3}$NbS$_{2}$, which
+exhibits chiral magnetic soliton lattice (CSL) state, is investigated. The
+magnetization displays strong magnetic anisotropy when the field is applied
+perpendicularly and parallel to the $c$-axis in low field region ($H<H_{S}$,
+$H_{S}$ is the saturation field). The critical exponents of Cr$_{1/3}$NbS$_{2}$
+are obtained as $\beta=$ 0.370(4), $\gamma=$ 1.380(2), and $\delta=$ 4.853(6),
+which are close to the theoretical prediction of three-dimensional Heisenberg
+model. Based on the scaling equation and the critical exponents, the $H-T$
+phase diagram in the vicinity of the phase transition is constructed, where two
+critical points are determined. One is a tricritical point which locates at the
+intersection between the CSL, forced ferromagnetic (FFM), and paramagnetic (PM)
+states. The other one is a critical point situated at the boundaries between
+CSL, helimagnetic (HM), and PM states.",1709.07740v1
+2017-11-15,Structural and Magnetic Characterizations of Co2FeGa/SiO2 Nanoparticles Prepared via Chemical Route,"We report the synthesis of Co2FeGa/SiO2 nanoparticles by sol-gel method and
+characterization using x-ray diffraction (XRD), transmission electron
+microscopy (TEM) and magnetic measurements. The Rietveld refinements of XRD
+data with space group Fm-3m clearly show the formation of A2 disorder single
+phase and the lattice constant is found to be 5.738 {\AA}. The
+energy-dispersive x-ray spectroscopy (EDX) confirm the elemental composition
+close the desired values. The value of coercivity is found to be around 283 Oe
+and 126 Oe, measured at 10 K and 300 K, respectively. We observed the
+saturation magnetization significantly lower than expected from Slater-Pauling
+rule. This decrease in the magnetic moment might be due to the presence of
+amorphous SiO2 during the synthesis process. A large content of small size SiO2
+particles along with Co2FeGa nanoparticles are also found in TEM study.",1711.05404v1
+2017-11-23,"Structural and magnetic properties of (Mg,Co)2W hexaferrites","Precursor powders of BaMg2-xCoxFe16O27 with (x = 0.0, 1.0, and 2.0) were
+prepared using high-energy ball milling, and the effects of chemical
+composition and sintering temperature on the structural and magnetic properties
+were investigated using x-ray diffractometer (XRD), scanning electron
+microscopy (SEM), and vibrating sample magnetometry (VSM). XRD patterns of the
+prepared samples indicated that crystallization of pure BaW hexaferrite phase
+was achieved at sintering temperature of 1300{\deg} C, while BaM and cubic
+spinel phase intermediate phases were obtained at lower sintering temperatures
+of 1100{\deg} C and 1200{\deg} C. SEM images revealed improvement of the
+crystallization of the structural phases, and growth of the particle size with
+increasing the sintering temperature. The magnetic data of the samples sintered
+at 1300{\deg} C revealed an increase of the saturation magnetization from 59.44
+emu/g to 72.56 emu/g with increasing Co concentration (x) from 0.0 to 2.0. The
+coercive field Hc decreased from 0.07 kOe at x = 0.0, to 0.03 kOe at x = 1.0,
+and then increases to 0.09 kOe at x = 2.0. The thermomagnetic curves of the
+samples sintered at 1300{\deg} C confirmed the existence of the W-type phase,
+and revealed spin reorientation transitions above room temperature.",1711.08581v1
+2017-11-27,Extreme magnetoresistance induced by Zeeman effect-driven electron-hole compensation and topological protection in MoSi$_2$,"The magnetoresistance is the magnetic field induced change of electrical
+resistivity of a material. Recent studies have revealed extremely large
+magnetoresistance in several non-magnetic semimetals, which has been explained
+on the basis of either electron-hole compensation or the Fermi surface
+topology, or the combination of both. Here, we present a single crystal study
+on MoSi$_2$, which exhibits extremely large magnetoresistance, approaching
+almost 10$^7$ % at 2 K and 14 T magnetic field. It is found that the
+electron-hole compensation level in MoSi$_2$ evolves with magnetic field, which
+is resulted from strong Zeeman effect, and found beneficial in boosting the
+large non-saturating magnetoresistance. The non-trivial Berry phase in the de
+Haas-van Alphen oscillations and the moderate suppression of backward
+scattering of the charge carriers lend support for the topological nature of
+this semimetal. The ultra-large carrier mobility of the topologically protected
+charge carriers reinforces the magnetoresistance of MoSi2 to an unprecedented
+large value.",1711.09646v1
+2017-11-30,Prompt photon yield and $v_2$ coefficient from gluon fusion induced by magnetic field in heavy-ion collision,"We compute the production of prompt photons and the $v_2$ harmonic
+coefficient in relativistic heavy-ion collisions induced by gluon fusion in the
+presence of an intense magnetic field, during the early stages of the reaction.
+The calculations take into account several parameters which are relevant to the
+description of the experimental transverse momentum distribution, and elliptic
+flow for RHIC and LHC energies. The main imput is the strength of the magnetic
+field which varies in magnitude from 1 to 3 times the pion mass squared, and
+allows the gluon fusion that otherwise is forbidden in the absence of the
+field. The high gluon occupation number and the value of the saturation scale
+also play an important role in our calculation, as well as a flow velocity and
+geometrical factors. Our results support the idea that the origin of at least
+some of the photon excess observed in heavy-ion experiments may arise from
+magnetic field induced processes, and gives a good description of the
+experimental data.",1711.11163v1
+2017-12-13,Co$_{2}$PtGa: A promising magnetic shape memory alloy with high martensite transition temperature,"In the present work, a combined theoretical and experimental study on
+Co$_{2}$PtGa Heusler alloy shows that it exhibits a martensite transition
+around 1320 K with a small thermal hysteresis (10 K). Dynamical stability of
+Co$_2$PtGa in the tetragonal phase has been established by the theoretically
+calculated phonon dispersion curves. Magnetization measurements suggest that
+this alloy is a ferromagnetic material with a saturation magnetic moment of
+2.83 $\mu_B$/f.u. at 2 K, which is in excellent agreement with the value
+obtained from \textit{ab-initio} calculations (2.87 $\mu_B$/f.u.). Our present
+study demonstrates that Co$_{2}$PtGa is a promising material for high
+temperature magnetic shape memory application.",1712.04765v4
+2018-02-15,Damping's effect on the magnetodynamics of spin Hall nano-oscillators,"We study the impact of spin wave damping ($\alpha$) on the auto-oscillation
+properties of nano-constriction based spin Hall nano-oscillators (SHNOs). The
+SHNOs are based on a 5 nm Pt layer interfaced to a 5 nm
+Py$_{100-x-y}$Pt$_{x}$Ag$_{y}$ magnetic layer, where the Pt and Ag contents are
+co-varied to keep the saturation magnetization constant (within 10 %), while
+$\alpha$ varies close to a factor of three. We systematically investigate the
+influence of the Gilbert damping on the magnetodynamics of these SHNOs by means
+of electrical microwave measurements. Under the condition of a constant field,
+the threshold current scales with the damping in the magnetic layer. The
+threshold current as a function of field shows a parabolic-like behavior, which
+we attribute to the evolution of the spatial profile of the auto-oscillation
+mode. The signal linewidth is smaller for the high-damping materials in low
+magnetic fields, although the lowest observed linewidth was measured for the
+alloy with least damping.",1802.05548v1
+2018-05-16,Magnetic properties of single crystalline itinerant ferromagnet AlFe2B2,"Single crystals of AlFe$_{2}$B$_{2}$ have been grown using the self flux
+growth method and then measured the structural properties, temperature and
+field dependent magnetization, and temperature dependent electrical resistivity
+at ambient as well as high pressure. The Curie temperature of AlFe$_{2}$B$_{2}$
+is determined to be $274$~K. The measured saturation magnetization and the
+effective moment for paramagnetic Fe-ion indicate the itinerant nature of the
+magnetism with a Rhode-Wohlfarth ratio $ \frac{M_{C}}{M_{sat}}\approx 1.14$.
+Temperature dependent resistivity measurements under hydrostatic pressure shows
+that transition temperature \textit{T$_C$} is suppressed down to 255 K for $p =
+2.24$~GPa pressure with a suppression rate of $\sim -8.9$~K/GPa. The anisotropy
+fields and magnetocrystalline anisotropy constants are in reasonable agreement
+with density functional theory calculations.",1805.06373v1
+2018-06-06,Pressure Evolution of Magnetism in URhGa,"In this paper, we report the results of an ambient and high pressure study of
+a 5f-electron ferromagnet URhGa. The work is focused on measurements of
+magnetic and thermodynamic properties of a single crystal sample and on the
+construction of the p-T phase diagram. Diamond anvil cells were employed to
+measure the magnetization and electrical resistivity pressures up to ~ 9 GPa.
+At ambient pressure, URhGa exhibits collinear ferromagnetic ordering of uranium
+magnetic moments {\mu}U ~ 1.1 {\mu}B (at 2 K) aligned along the c-axis of the
+hexagonal crystal structure below the Curie temperature TC = 41K. With the
+application of pressure up to 5GPa the ordering temperature TC initially
+increases whereas the saturated moment slightly decreases. The rather
+unexpected evolution is put in the context of the UTX family of compounds.",1806.02686v1
+2018-07-31,Tunable Half-Metallicity and Edge Magnetism of H-saturated InSe Nanoribbons,"We report on a theoretical study of electronic and magnetic properties of
+hydrogen-saturated InSe nanoribbons (H-ZISNs). Based on hybrid-functional
+first-principles calculations, we find that H-ZISNs exhibit tunable
+half-metallicity and short-range ferromagnetic order. We first show that p-type
+doping turns narrow H-ZISNs from semimetal to half-metal with spin-polarization
+along In-terminated edge. This behavior is further analyzed in terms of a
+two-band tight-binding model, which provides a tractable description of the
+H-ZISN electronic structure, and serves as a starting point for the
+determination of magnetic interactions. The dominant exchange interaction
+determined within the Heisenberg model is found to be ferromagnetic
+independently of the ribbon width and charge doping. Short-range stability of
+magnetic order is assessed in terms of the zero-field spin correlation length,
+which is found to be about 1 nm at liquid nitrogen temperatures. Finally, by
+calculating spin-dependent transport properties, we find a doping regime in
+which strongly spin-selective electrical conductivities can be observed. Our
+findings suggest that H-ZISNs are appealing candidates for the realization of
+spintronic effects at the nanoscale.",1807.11715v2
+2018-09-06,Epitaxial growth and magnetic properties of NiMnAs film on GaAs substrate,"Single-phase Ni0.46Mn0.54As films with strained C1b symmetry have been
+successfully grown on GaAs (001) substrates by molecular-beam epitaxy. The
+epitaxial relationship between the film and the substrate has been studied
+using synchrotron radiation, and a preferred configuration of (110)-orientated
+Ni0.46Mn0.54As on (001)-orientated GaAs was revealed. In addition, the magnetic
+properties of the films were found to be significantly influenced by the growth
+temperature. The optimized growth temperature is determined to be ~370 degree
+Celsius , for which relatively high Curie temperature, large saturation
+magnetization and coercive field, as well as the pronounced in-plane magnetic
+anisotropy were obtained. According to the results of X-ray absorption
+spectroscopy, the above phenomenon can be attributed to the variation of the
+local electronic structure of the Mn atoms. Our work provides useful
+information for the further investigations of NiMnAs, which is theoretically
+predicted to host robust half-metallicity.",1809.01976v2
+2018-11-08,Sensitivity enhancement for a light axion dark matter search with magnetic material,"The sensitivity of experimental searches for axion dark matter coupled to
+photons is typically proportional to the strength of the applied static
+magnetic field. We demonstrate how a permeable material can be used to enhance
+the magnitude of this static magnetic field, and therefore improve the
+sensitivity of such searches in the low frequency lumped-circuit limit. Using
+gadolinium iron garnet toroids at temperature 4.2 K results in a factor of 4
+enhancement compared to an air-core toroidal design. The enhancement is limited
+by magnetic saturation. Correlation of signals from three such toroids allows
+efficient rejection of systematics due to electromagnetic interference. The
+sensitivity of a centimeter-scale axion dark matter search based on this
+approach is on the order of $g_{a\gamma\gamma}\approx10^{-9}$ GeV$^{-1}$ after
+8 hours of data collection for axion masses near $10^{-10}$ eV. This approach
+may substantially extend the sensitivity reach of large-volume lumped element
+axion dark matter searches.",1811.03231v1
+2019-02-21,Slowing the Spins of Stellar Cores,"The angular momentum (AM) evolution of stellar interiors, along with the
+resulting rotation rates of stellar remnants, remains poorly understood.
+Asteroseismic measurements of red giant stars reveal that their cores rotate
+much faster than their surfaces, but much slower than theoretically predicted,
+indicating an unidentified source of AM transport operates in their radiative
+cores. Motivated by this, we investigate the magnetic Tayler instability and
+argue that it saturates when turbulent dissipation of the perturbed magnetic
+field energy is equal to magnetic energy generation via winding. This leads to
+larger magnetic field amplitudes, more efficient AM transport, and smaller
+shears than predicted by the classic Tayler-Spruit dynamo. We provide
+prescriptions for the effective AM diffusivity and incorporate them into
+numerical stellar models, finding they largely reproduce (1) the nearly rigid
+rotation of the Sun and main sequence stars, (2) the core rotation rates of
+low-mass red giants during hydrogen shell and helium burning, and (3) the
+rotation rates of white dwarfs. We discuss implications for stellar rotational
+evolution, internal rotation profiles, rotational mixing, and the spins of
+compact objects.",1902.08227v2
+2019-03-14,Thermoelectric property of a one dimensional channel in the presence of a transverse magnetic field,"We studied the thermal conduction through a quantum point contact (QPC),
+defined in GaAs-AlGaAs heterostructure, in the presence of a transverse
+magnetic field. A shift in the position of thermo-voltage peak is observed with
+increasing field. The position of the thermo-voltage peak follows the
+Cutler-Mott relation in the small field regime (B < 0.5 T); it starts diverging
+from the Cutler-Mott relation in the moderate field regime, where a cubic
+magnetic field term dominates over the trivial quadratic term; eventually the
+shift saturates in the large field regime (B > 3.0 T). Our results suggest that
+additional calibration is necessary when using QPC as thermometry, especially
+when the transverse magnetic field is applied.",1903.06096v6
+2019-04-05,Centrality dependence of photon yield and elliptic flow from gluon fusion and splitting induced by magnetic fields in relativistic heavy-ion collisions,"We compute the photon yield and elliptic flow coefficient in relativistic
+heavy-ion collisions from gluon fusion and splitting processes induced by a
+magnetic field for different centralities. The calculation accounts for the
+intense magnetic field and the high gluon occupation number at early times. The
+photon production induced by these process represents an excess contribution
+over calculations without magnetic field effects. We compare this excess to the
+difference between PHENIX data and recent hydrodynamic calculations for the
+photon transverse momentum distribution and elliptic flow coefficient $v_2$.
+The time evolution of the field strength and reaction volume is computed using
+UrQMD. We show that with reasonable values for the saturation scale, the
+calculation helps to better describe the experimental results obtained at RHIC
+energies for the lowest part of the transverse photon momentum at different
+centralities.",1904.02938v2
+2019-05-27,Magnetocaloric properties of an Ising antiferromagnet on a kagome lattice,"Owing to a high degree of geometrical frustration an Ising antiferromagnet on
+a kagome lattice (IAKL) is known to exhibit no long-range ordering at any
+temperature, including the ground state. Nevertheless, at low temperatures it
+shows a strongly correlated, highly fluctuating regime known as a cooperative
+paramagnet or classical spin liquid. In the ground state it is characterized by
+a macroscopic degeneracy which translates to a relatively large value of the
+residual entropy. It has been shown that the presence of a macroscopic
+degeneracy associated with geometrical frustration below the saturation field
+can facilitate an enhanced magnetocaloric effect (MCE), which can exceed that
+of an ideal paramagnet with equivalent spin by more than an order of magnitude.
+In the present study we investigate magnetic and magnetocaloric properties of
+IAKL by Monte Carlo simulation. In particular, we calculate the entropy of the
+system using the thermodynamic integration method and evaluate quantities which
+characterize MCE, such as the isothermal entropy and adiabatic temperature
+changes in a varying magnetic field. It is found that IAKL shows the most
+interesting magnetocaloric properties at low temperatures and moderate magnetic
+fields, suggesting its potential to be used in technological applications for
+low-temperature magnetic refrigeration.",1905.11494v1
+2019-05-30,Predicting New Iron Garnet Thin Films with Perpendicular Magnetic Anisotropy,"Perpendicular magnetic anisotropy (PMA) is a necessary condition for many
+spintronic applications like spin-orbit torques switching, logic and memory
+devices. An important class of magnetic insulators with low Gilbert damping at
+room temperature are iron garnets, which only have a few PMA types such as
+terbium and samarium iron garnet. More and stable PMA garnet options are
+necessary for researchers to be able to investigate new spintronic phenomena.
+In this study, we predict 20 new substrate/magnetic iron garnet film pairs with
+stable PMA at room temperature. The effective anisotropy energies of 10
+different garnet films that are lattice-matched to 5 different commercially
+available garnet substrates have been calculated using shape, magnetoelastic
+and magnetocrystalline anisotropy terms. Strain type, tensile or compressive
+depending on substrate choice, as well as the sign and the magnitude of the
+magnetostriction constants of garnets determine if a garnet film may possess
+PMA. We show the conditions in which Samarium, Gadolinium, Terbium, Holmium,
+Dysprosium and Thulium garnets may possess PMA on the investigated garnet
+substrate types. Guidelines for obtaining garnet films with low damping are
+presented. New PMA garnet films with tunable saturation moment and field may
+improve spin-orbit torque memory and compensated magnonic thin film devices.",1905.13042v1
+2019-07-04,Dynamics of the magnetoelastic phase transition and adiabatic temperature change in Mn1.3Fe0.7P0.5Si0.55,"The adiabatic temperature change DTad of a Mn1.3Fe0.7P0.5Si0.55 Fe2P-type
+alloy was measured under different magnetic field-sweep rates from 0.93 Ts-1 to
+2870 Ts-1. We find a field-sweep-rate independent magnetocaloric effect due to
+a partial alignment of magnetic moments in the paramagnetic region overlapping
+with the magnetocaloric effect of the first-order phase transition.
+Additionally, the first-order phase transition is not completed even in fields
+up to 20 T leading to a non-saturating behavior of DTad. Measurements in
+different pulsed fields reveal that the first-order phase transition cannot
+follow the fast field changes as previously assumed, resulting in a distinct
+field-dependent hysteresis in DTad.",1907.02307v1
+2019-07-10,The superior role of the Gilbert damping on the signal-to-noise ratio in heat-assisted magnetic recording,"In magnetic recording the signal-to-noise ratio (SNR) is a good indicator for
+the quality of written bits. However, a priori it is not clear which parameters
+have the strongest influence on the SNR. In this work, we investigate the role
+of the Gilbert damping on the SNR. Grains consisting of FePt like hard magnetic
+material with two different grain sizes $d_1=5\,$nm and $d_2=7\,$nm are
+considered and simulations of heat-assisted magnetic recording (HAMR) are
+performed with the atomistic simulation program VAMPIRE. The simulations
+display that the SNR saturates for damping constants larger or equal than 0.1.
+Additionally, we can show that the Gilbert damping together with the bit length
+have a major effect on the SNR whereas other write head and material parameters
+only have a minor relevance on the SNR.",1907.04577v2
+2019-10-27,On a variational formulation of the weakly nonlinear magnetic Rayleigh--Taylor instability,"The magnetic-Rayleigh--Taylor (MRT) instability is a ubiquitous phenomenon
+that occurs in magnetically-driven Z-pinch implosions. It is important to
+understand this instability since it can decrease the performance of such
+implosions. In this work, I present a theoretical model for the weakly
+nonlinear MRT instability. I obtain such model by asymptotically expanding an
+action principle, whose Lagrangian leads to the fully nonlinear MRT equations.
+After introducing a suitable choice of coordinates, I show that the theory can
+be cast as a Hamiltonian system, whose Hamiltonian is calculated up to sixth
+order in a perturbation parameter. The resulting theory captures the harmonic
+generation of MRT modes. In particular, it is shown that the saturation
+amplitude of the linear MRT instability grows as the stabilization effect of
+the magnetic-field tension increases. Overall, the theory provides an intuitive
+interpretation of the weakly nonlinear MRT instability and provides a
+systematic approach for studying this instability in more complex settings.",1910.12167v1
+2020-02-24,Magnetic field configurations in neutron stars from MHD simulations,"We have studied numerically the evolution of magnetic fields in barotropic
+neutron stars, by performing nonlinear magnetohydrodynamical simulations with
+the code PLUTO. For both initially predominantly poloidal and toroidal fields,
+with varying strengths, we find that the field settles down to a mixed
+poloidal-toroidal configuration, where the toroidal component contributes
+between 10% and 20% of the total magnetic energy. This is, however, not a
+strict equilibrium, as the instability leads to the development of turbulence,
+which in turn gives rise to an inverse helicity cascade, which determines the
+final 'twisted torus' setup. The final field configuration is thus dictated by
+the non-linear saturation of the instability and is not stationary. The average
+energy of the poloidal and toroidal components, however, is approximately
+stable in our simulations, and a complex multipolar structure emerges at the
+surface, while the magnetic field is dipolar at the exterior boundary, outside
+the star.",2002.10357v2
+2020-03-17,Domain wall dynamics in stepped magnetic nanowire with perpendicular magnetic anisotropy,"Micromagnetic simulation is carried out to investigate the current-driven
+domain wall (DW) in a nanowire with perpendicular magnetic anisotropy (PMA). A
+stepped nanowire is proposed to pin DW and achieve high information storage
+capacity based on multi-bit per cell scheme. The DW speed is found to increase
+for thicker and narrower nanowires. For depinning DW from the stepped region,
+the current density Jdep is investigated with emphasis on device geometry and
+materials intrinsic properties. The Jdep could be analytically determined as a
+function of the nanocontriction dimension and the thickness of the nanowire.
+Furthermore, Jdep is found to exponential dependent on the anisotropy energy
+and saturation magnetization, offering thus more flexibility in adjusting the
+writing current for memory applications.",2003.07721v1
+2020-03-26,Bipolar spin Hall nano-oscillators,"We demonstrate a novel type of spin Hall nano-oscillator (SHNO) that allows
+for efficient tuning of magnetic auto-oscillations over an extended range of
+gigahertz frequencies, using bipolar direct currents at constant magnetic
+fields. This is achieved by stacking two distinct ferromagnetic layers with a
+platinum interlayer. In this device, the orientation of the spin polarised
+electrons accumulated at the top and bottom interfaces of the platinum layer is
+switched upon changing the polarity of the direct current. As a result, the
+effective anti-damping required to drive large amplitude auto-oscillations can
+appear either at the top or bottom magnetic layer. Tuning of the
+auto-oscillation frequencies by several gigahertz can be obtained by combining
+two materials with sufficiently different saturation magnetization. Here we
+show that the combination of NiFe and CoFeB can result in 3 GHz shifts in the
+auto-oscillation frequencies. Bipolar SHNOs as such may bring enhanced
+synchronisation capabilities to neuromorphic computing applications.",2003.11776v1
+2020-04-07,Quantum and Thermal Phase Transitions of the Triangular SU(3) Heisenberg Model under Magnetic Fields,"We study the quantum and thermal phase transition phenomena of the SU(3)
+Heisenberg model on triangular lattice in the presence of magnetic fields.
+Performing a scaling analysis on large-size cluster mean-field calculations
+endowed with a density-matrix-renormalization-group solver, we reveal the
+quantum phases selected by quantum fluctuations from the massively degenerate
+classical ground-state manifold. The magnetization process up to saturation
+reflects three different magnetic phases. The low- and high-field phases have
+strong nematic nature, and especially the latter is found only via a nontrivial
+reconstruction of symmetry generators from the standard spin and quadrupolar
+description. We also perform a semiclassical Monte Carlo simulations to show
+that thermal fluctuations prefer the same three phases as well. Moreover, we
+find that exotic topological phase transitions driven by the binding-unbinding
+of fractional (half-)vortices take place, due to the nematicity of the low- and
+high-field phases. Possible experimental realization with alkaline-earth-like
+cold atoms is also discussed.",2004.03250v2
+2020-04-22,Magnetic phase diagram of the linear quantum ferro-antiferromagnet Cs$_{2}$Cu$_{2}$Mo$_{3}$O$_{12}$,"A single-crystal sample of the frustrated quasi one-dimensional quantum
+magnet Cs$_{2}$Cu$_{2}$Mo$_{3}$O$_{12}$ is investigated by magnetic and
+thermodynamic measurements.A combination of specific heat and magnetic torque
+measurements maps out the entire $H$-$T$ phase diagram for three
+orientations.Remarkably, a new phase emerges below the saturation field,
+irrespective of the crystal orientation. It is suggested that the presaturation
+phase represents spin-nematic order or other multi-magnon condensate. The phase
+diagrams within the long-range ordered dome are qualitatively different for
+each geometry. In particular, multiple transitions are identified in the field
+along the chain direction.",2004.10636v3
+2020-05-15,Multiple magnon modes in spin-1/2 Heisenberg antiferromagnet on simple square lattice in strong magnetic field,"We discuss spin-$\frac12$ Heisenberg antiferromagnet on simple square lattice
+in magnetic field $H$ using recently proposed bond-operator technique. It is
+well known that magnetically ordered phases of quantum magnets are well
+described at least qualitatively by the conventional spin-wave theory that only
+introduces quantum corrections into the classical solution of the problem. We
+observe that quantum fluctuations change drastically dynamical properties of
+the considered model at $H$ close to its saturation value: the dynamical
+structure factor shows anomalies corresponding to Green's function poles which
+have no counterparts in the spin-wave theory. That is, quantum fluctuations
+produce multiple short-wavelength magnon modes not changing qualitatively the
+long-wavelength spin dynamics. Our results are in agreement with previous
+quantum Monte-Carlo simulations and exact diagonalization of finite clusters.",2005.07537v3
+2020-07-12,Three-Dimensional Chiral Magnetization Structures in FeGe Nanospheres,"Skyrmions, spin spirals, and other chiral magnetization structures developing
+in materials with intrinsic Dzyaloshinsky-Moriya Interaction display unique
+properties that have been the subject of intense research in thin-film
+geometries. Here we study the formation of three-dimensional chiral
+magnetization structures in FeGe nanospheres by means of micromagnetic
+finite-element simulations. In spite of the deep sub-micron particle size, we
+find a surprisingly large number of distinct equilibrium states, namely,
+helical, meron, skyrmion, chiral-bobber and quasi-saturation state. The
+distribution of these states is summarized in a phase diagram displaying the
+ground state as a function of the external field and particle radius. This
+unusual multiplicity of possible magnetization states in individual
+nanoparticles could be a useful feature for multi-state memory devices. We also
+show that the magneto-dipolar interaction is almost negligible in these
+systems, which suggests that the particles could be arranged at high density
+without experiencing unwanted coupling.",2007.05939v1
+2020-09-02,Non-local spin Seebeck effect in the bulk easy-plane antiferromagnet NiO,"We report the observation of magnon spin currents generated by the Spin
+Seebeck effect (SSE) in a bulk single crystal of the easy-plane antiferromagnet
+NiO. A magnetic field induces a non-degeneracy and thereby an imbalance in the
+population of magnon modes with opposite spin. A temperature gradient then
+gives rise to a non-zero magnon spin current. This SSE is measured both in a
+local and a non-local geometry at 5$\,$K in bulk NiO. The magnetic field
+dependence of the obtained signal is modelled by magnetic field splitting of
+the low energy magnon modes, affecting the spin Seebeck coefficient. The
+relevant magnon modes at this temperature are linked to cubic anisotropy and
+magnetic dipole-dipole interactions. The non-local signal deviates from the
+expected quadratic Joule heating by saturating at a current from around
+75$\,\mu A$ in the injector. The magnon chemical potential does not decay
+exponentially with distance and inhomogeneities may be the result of local
+magnon accumulations.",2009.01160v1
+2020-09-03,Thermal effects in spin torque switching of perpendicular magnetic tunnel junctions at cryogenic temperatures,"Temperature plays an important role in spin torque switching of magnetic
+tunnel junctions causing magnetization fluctuations that decrease the switching
+voltage but also introduce switching errors. Here we present a systematic study
+of the temperature dependence of the spin torque switching probability of
+state-of-the-art perpendicular magnetic tunnel junction nanopillars (40 to 60
+nm in diameter) from room temperature down to 4 K, sampling up to a million
+switching events. The junction temperature at the switching voltage---obtained
+from the thermally assisted spin torque switching model---saturates at
+temperatures below about 75 K, showing that junction heating is significant
+below this temperature and that spin torque switching remains highly stochastic
+down to 4 K. A model of heat flow in a nanopillar junction shows this effect is
+associated with the reduced thermal conductivity and heat capacity of the
+metals in the junction.",2009.01743v1
+2020-11-16,Electrically induced strong modulation of magnons transport in ultrathin magnetic insulator films,"Magnon transport through a magnetic insulator can be controlled by
+current-biased heavy-metal gates that modulate the magnon conductivity via the
+magnon density. Here, we report nonlinear modulation effects in 10$\,$nm thick
+yttrium iron garnet (YIG) films. The modulation efficiency is larger than
+40\%/mA. The spin transport signal at high DC current density (2.2$\times
+10^{11}\,$A/m$^{2}$) saturates for a 400$\,$nm wide Pt gate, which indicates
+that even at high current levels a magnetic instability cannot be reached in
+spite of the high magnetic quality of the films.",2011.07800v1
+2021-01-07,Quantum annealing simulation of out-of-equilibrium magnetization in a spin-chain compound,"Geometrically frustrated spin-chain compounds such as Ca3Co2O6 exhibit
+extremely slow relaxation under a changing magnetic field. Consequently, both
+low-temperature laboratory experiments and Monte Carlo simulations have shown
+peculiar out-of-equilibrium magnetization curves, which arise from trapping in
+metastable configurations. In this work we simulate this phenomenon in a
+superconducting quantum annealing processor, allowing us to probe the impact of
+quantum fluctuations on both equilibrium and dynamics of the system. Increasing
+the quantum fluctuations with a transverse field reduces the impact of
+metastable traps in out-of-equilibrium samples, and aids the development of
+three-sublattice ferrimagnetic (up-up-down) long-range order. At equilibrium we
+identify a finite-temperature shoulder in the 1/3-to-saturated phase
+transition, promoted by quantum fluctuations but with entropic origin. This
+work demonstrates the viability of dynamical as well as equilibrium studies of
+frustrated magnetism using large-scale programmable quantum systems, and is
+therefore an important step toward programmable simulation of dynamics in
+materials using quantum hardware.",2101.02769v1
+2021-01-26,Hydrodynamical study of Terahertz emission in magnetized graphene field-effect transistors,"Several hydrodynamic descriptions of charge transport in graphene have been
+presented in the late years. We discuss a general hydrodynamic model governing
+the dynamics of a two-dimensional electron gas in a magnetized field-effect
+transistor in the slow drift regime. The Dyakonov--Shur instability is
+investigated including the effect of weak magnetic fields (i.e. away from
+Landau levels). We show that the gap on the dispersion relation prevents the
+instability to reach the lower frequencies thus imposing a limit on the Mach
+number of the electronic flow. Furthermore, we discuss that the presence of the
+external magnetic field decreases the growth rate of the instability, as well
+as the saturation amplitude. The numerical results from our simulations and the
+presented higher order dynamic mode decomposition support such reasoning.",2101.10786v2
+2021-02-19,Critical Energy Dissipation in a Binary Superfluid Gas by a Moving Magnetic Obstacle,"We study the critical energy dissipation in an atomic superfluid gas with two
+symmetric spin components by an oscillating magnetic obstacle. Above a certain
+critical oscillation frequency, spin-wave excitations are generated by the
+magnetic obstacle, demonstrating the spin superfluid behavior of the system.
+When the obstacle is strong enough to cause density perturbations via local
+saturation of spin polarization, half-quantum vortices (HQVs) are created for
+higher oscillation frequencies, which reveals the characteristic evolution of
+critical dissipative dynamics from spin-wave emission to HQV shedding. Critical
+HQV shedding is further investigated using a pulsed linear motion of the
+obstacle, and we identify two critical velocities to create HQVs with different
+core magnetization.",2102.09826v2
+2021-02-24,Quantum paramagnetism and magnetization plateaus in a kagome-honeycomb Heisenberg antiferromagnet,"A spin-1/2 Heisenberg model on honeycomb lattice is investigated by doing
+triplon analysis and quantum Monte Carlo calculations. This model, inspired by
+Cu$_2$(pymca)$_3$(ClO$_4$), has three different antiferromagnetic exchange
+interactions ($J_A$, $J_B$, $J_C$) on three different sets of nearest-neighbour
+bonds which form a kagome superlattice. While the model is bipartite and
+unfrustrated, its quantum phase diagram is found to be dominated by a quantum
+paramagnetic phase that is best described as a spin-gapped hexagonal-singlet
+state. The N\'eel antiferromagnetic order survives only in a small region
+around $J_A=J_B=J_C$. The magnetization produced by external magnetic field is
+found to exhibit plateaus at 1/3 and 2/3 of the saturation value, or at 1/3
+alone, or no plateaus. Notably, the plateaus exist only inside a bounded region
+within the hexagonal-singlet phase. This study provides a clear understanding
+of the spin-gapped behaviour and magnetization plateaus observed in
+Cu$_2$(pymca)$_3$(ClO$_4$), and also predicts the possible disappearance of 2/3
+plateau under pressure.",2102.12291v2
+2021-03-24,Effective strain manipulation of the antiferromagnetic state of polycrystalline NiO,"As a candidate material for applications such as magnetic memory,
+polycrystalline antiferromagnets offer the same robustness to external magnetic
+fields, THz spin dynamics, and lack of stray field as their single crystalline
+counterparts, but without the limitation of epitaxial growth and lattice
+matched substrates. Here, we first report the detection of the average Neel
+vector orientiation in polycrystalline NiO via spin Hall magnetoresistance
+(SMR). Secondly, by applying strain through a piezo-electric substrate, we
+reduce the critical magnetic field required to reach a saturation of the SMR
+signal, indicating a change of the anisotropy. Our results are consistent with
+polycrystalline NiO exhibiting a positive sign of the in-plane
+magnetostriction. This method of anisotropy-tuning offers an energy efficient,
+on-chip alternative to manipulate a polycrystalline antiferromagnets magnetic
+state.",2103.13105v1
+2021-04-22,Impact of Fe$_{80}$B$_{20}$ insertion on the properties of dual-MgO perpendicular magnetic tunnel junctions,"We explore the impact of Fe80B20 inserted at both
+Co$_{20}$Fe$_{80}$B$_{20}$/MgO interfaces of dual-MgO free layers (FLs) in
+bottom-pinned magnetic tunnel junctions (MTJs). MTJ stacks are annealed for 30
+min at 350 $^\circ$C and 400 $^\circ$C in a vacuum after film deposition.
+Current-in-plane tunneling measurements are carried out to characterize
+magnetotransport properties of the MTJs. Conventional magnetometry measurements
+and ferromagnetic resonance are conducted to estimate the saturation
+magnetization, the effective perpendicular anisotropy field and the Gilbert
+damping of dual-MgO FLs as a function of the Fe$_{80}$B$_{20}$ thickness and
+annealing temperatures. With ultrathin Fe$_{80}$B$_{20}$ (0.2 - 0.4 nm)
+inserted, perpendicular magnetic anisotropy (PMA) of FLs increases with similar
+tunnel magneto-resistance (TMR) and low damping values. As Fe$_{80}$B$_{20}$
+layer thickness further increases (0.6 - 1.2 nm), both TMR and PMA degrade, and
+damping increases dramatically. This study demonstrates a novel approach to
+tune properties of MTJ stacks with dual-MgO FLs up to 400 $^\circ$C annealing,
+which enables MTJ stacks for various applications.",2104.10918v1
+2021-05-09,Planar topological Hall effect in a hexagonal ferromagnetic Fe5Sn3 single crystal,"The planar topological Hall effect (PTHE), appeared when the magnetic field
+tended to be along the current, is believed to result from the real-space Berry
+curvature of the spin spiral structure and has been experimentally observed in
+skyrmion-hosting materials. In this paper, we report an experimental
+observation of the PTHE in a hexagonal ferromagnetic Fe5Sn3 single crystal.
+With a current along the c axis of Fe5Sn3, the transverse resistivity curves
+exhibited obvious peaks near the saturation field as the magnetic field rotated
+to the current and appeared more obvious with increasing temperature, which was
+related to the noncoplanar spin structure in Fe5Sn3. This spin structure
+induced nonzero scalar spin chirality, which acted as fictitious magnetic
+fields to conduction electrons and contributed the additional transverse
+signal. These findings deepen the understanding of the interaction between
+conduction electrons and complex magnetic structures and are instructive for
+the design of next-generation spintronic devices.",2105.03898v1
+2021-05-10,Nonlinear MHD simulation of core plasma collapse events in stellarators,"The core collapse events observed in a stellarator experiment are studied by
+a three-dimensional nonlinear MHD simulations. In the low magnetic shear
+configuration like the Wendelstein 7-X, the rotational transform profile is
+very sensitive to the toroidal current density. The 3D equilibrium with
+localized toroidal current density is studied. If the toroidal current density
+follows locally in the middle of the plasma minor radius, the rotational
+transform is also changed locally. Sometimes, the magnetic topology changes due
+to appearing the magnetic island. The nonlinear behaviors of the MHD
+instability are studied by a full three-dimensional nonlinear MHD code. It was
+found that a following sequence. At first, the high-n ballooning-type mode
+structure appears in the plasma core, and then the mode linearly grows. The
+high-n ballooning modes nonlinearly couple and saturate. The mode structure
+changes to the low-n mode. In that phase, the magnetic field structure becomes
+strongly stochastic into the plasma core due to the nonlinear coupling.
+Finally, the plasma pressure diffuses along the stochastic field lines, and
+then the core plasma pressure drops. This is an important results to interpret
+the core collapse event by strong nonlinear coupling.",2105.04119v2
+2021-06-24,Low-dimensional antiferromagnetic fluctuations in the heavy-fermion paramagnetic ladder UTe$_2$,"Inelastic-neutron-scattering measurements were performed on a single crystal
+of the heavy-fermion paramagnet UTe$_2$ above its superconducting temperature.
+We confirm the presence of antiferromagnetic fluctuations with the
+incommensurate wavevector $\mathbf{k}_1=(0,0.57,0)$. A quasielastic signal is
+found, whose momentum-transfer dependence is compatible with fluctuations of
+magnetic moments $\mu\parallel\mathbf{a}$, with a sine-wave modulation of
+wavevector $\mathbf{k}_1$ and in-phase moments on the nearest U atoms. Low
+dimensionality of the magnetic fluctuations, consequence of the ladder
+structure, is indicated by weak correlations along the direction $\mathbf{c}$.
+These fluctuations saturate below the temperature $T_1^*\simeq15$~K, in
+possible relation with anomalies observed in thermodynamic,
+electrical-transport and nuclear-magnetic-resonance measurements. The absence
+or weakness of ferromagnetic fluctuations, in our data collected at
+temperatures down to 2.1 K and energy transfers from 0.6 to 7.5 meV, is
+emphasized. These results constitute constraints for models of
+magnetically-mediated superconductivity in UTe$_2$.",2106.13087v1
+2021-08-22,Chiral vortical catalysis,"Gluon interaction introduces remarkable corrections to the magnetic
+polarization effects on the chiral fermions, which is known as the inverse
+magnetic catalysis. It is a natural speculation that the vorticity, which has
+many similar properties as magnetic field, would bring non-negligible
+contribution to the chiral rotational suppression. Using the intuitive
+semi-classical background field method we studied the rotation dependence of
+the effective strong interaction coupling. Contrary to the magnetic field case
+the rotation increases the effective coupling which leads to slowing down the
+condensate melting procedure with temperature. This could be named as the
+chiral vortical catalysis or inverse rotation suppression. Imposing such
+dependence to the coupling in the NJL model, we numerically checked this
+analysis qualitatively. The pseudo critical temperature is shown to rise with
+the rotation and approach saturation eventually which may be induced by the
+model cutoff.",2108.09622v1
+2021-11-09,Design of soft magnetic materials,"We present a strategy for the design of ferromagnetic materials with
+exceptionally low magnetic hysteresis, quantified by coercivity. In this
+strategy, we use a micromagnetic algorithm that we have developed in previous
+research and which has been validated by its success in solving the ""Permalloy
+Problem"" -- the well-known difficulty of predicting the composition 78.5% Ni of
+lowest coercivity in the Fe-Ni system -- and by the insight, it provides into
+the ""Coercivity Paradox"" of W. F. Brown. Unexpectedly, the design strategy
+predicts that cubic materials with large saturation magnetization $m_s$ and
+large magnetocrystalline anisotropy constant $\kappa_1$ will have low
+coercivity on the order of that of Permalloy, as long as the magnetostriction
+constants $\lambda_{100}, \lambda_{111}$ are tuned to special values. The
+explicit prediction for a cubic material with low coercivity is the
+dimensionless number $(c_{11}-c_{12}) \lambda_{100}^2/\kappa_1 = 81$ for
+$\langle 100 \rangle$ easy axes. The results would seem to have a broad
+potential application, especially to magnetic materials of interest in energy
+research.",2111.05456v1
+2021-12-14,"Ground State, Magnetization Process and Bipartite Quantum Entanglement of a Spin-1/2 Ising-Heisenberg Model on Planar Lattices of Interconnected Trigonal Bipyramids","The ground state, magnetization scenario and the local bipartite quantum
+entanglement of a mixed spin-$1/2$ Ising--Heisenberg model in a magnetic field
+on planar lattices formed by identical corner-sharing bipyramidal plaquettes is
+examined by combining the exact analytical concept of generalized
+decoration-iteration mapping transformations with Monte Carlo simulations
+utilizing the Metropolis algorithm. The ground-state phase diagram of the model
+involves six different phases, namely, the standard ferrimagnetic phase, fully
+saturated phase, two unique quantum ferrimagnetic phases, and two
+macroscopically degenerate quantum ferrimagnetic phases with two chiral degrees
+of freedom of the Heisenberg triangular clusters. The diversity of ground-state
+spin arrangement is manifested themselves in seven different magnetization
+scenarios with one, two or three fractional plateaus whose values are
+determined by the number of corner-sharing plaquettes. The low-temperature
+values of the concurrence demonstrate that the bipartite quantum entanglement
+of the Heisenberg spins in quantum ferrimagnetic phases is field independent,
+but twice as strong if the Heisenberg spin arrangement is unique as it is
+two-fold degenerate.",2112.07233v1
+2022-03-09,The Ca II H&K Rotation-Activity Relation in 53 mid-to-late type M-Dwarfs,"In the canonical theory of stellar magnetic dynamo, the tachocline in
+partially convective stars serves to arrange small-scale fields, generated by
+stochastic movement of plasma into a coherent large-scale field. Mid-to-late
+M-dwarfs, which are fully convective, show more magnetic activity than
+classical magnetic dymano theory predicts. However, mid-to-late M-dwarfs show
+tight correlations between rotation and magnetic activity, consistent with
+elements of classical dynamo theory. We use data from Magellan Inamori Kyocera
+Echelle (MIKE) Spectrograph to detail the relation between Ca II H\&K flux and
+rotation period for these low-mass stars. We measure $R'_{HK}$ values for 53
+spectroscopically identified M-dwarfs selected from the MEarth survey; these
+stars span spectral classes from M5.0 to M3.5 and have rotation periods ranging
+from hours to months. We present the rotation--activity relationship as traced
+through these data. We find power law and saturated regimes consistent to
+within one sigma of previously published results and observe a mass dependence
+in $R'_{HK}$.",2203.04999v1
+2022-03-14,Magnetic-field and pressure phase diagram of the triangular lattice antiferromagnet CsCuCl$_3$ clarified by magnetic susceptibility measured with a proximity detector oscillator,"The effect of pressure ($P$) on magnetic susceptibility of CsCuCl$_3$ was
+examined in magnetic fields ($\rm \mu_0$$H$) of up to 51 T using a proximity
+detector oscillator (PDO), and the $H$-$P$ phase diagram of CsCuCl$_3$ was
+constructed over the saturation field ($H_{\rm sat}$). We found that, with
+increasing $P$, $H_{\rm sat}$ increases and the uud-phase that appeared at $P$
+= 0.7 GPa widened. Based on comparison between the experimental and calculated
+$H$-$P$ phase diagrams, the Y-phase was predicted to appear above 1.7 GPa. The
+interchain antiferromagnetic exchange interaction in the $ab$-plane was
+evaluated and found to increase with increasing $P$, which is consistent with a
+previous study under high pressure [D. Yamamoto {\it et al.}, Nat. Commun. {\bf
+12}, 4263 (2021).]. Moreover, an anomaly was observed below $P$ = 0.6 GPa just
+below $H_{\rm sat}$ and might be a new phase transition derived from nonlinear
+response caused by the PDO technique.",2203.06869v1
+2022-04-16,Entanglement and quantum correlations in the XX spin-$1/2$ honeycomb lattice,"The ground state phase diagram of the dimerized spin-1/2 XX honeycomb model
+in presence of a transverse magnetic field (TF) is known. With the absence of
+the magnetic field, two quantum phases, namely, the N\'eel and the dimerized
+phases have been identified. Moreover, canted N\'eel and the paramagnetic (PM)
+phases also emerge by applying the magnetic field. In this paper, using two
+complementary numerical exact techniques, Lanczos exact diagonalization, and
+Density matrix renormalization group (DMRG) methods, we study this model by
+focusing on the quantum correlations, the concurrence, and the quantum discord
+(QD) among nearest-neighbor spins. We show that the quantum correlations can
+capture the position of the quantum critical points in the whole range of the
+ground state phase diagram consistent with previous results. Although the
+concurrence and the QD are short-range, informative about long-ranged critical
+correlations. In addition, we address a ""magnetic-entanglement"" behavior that
+starts from an entangled field around the saturation field.",2204.07708v1
+2022-05-02,Novel quantum phase of the chromium spinel oxide HgCr$_{\rm 2}$O$_{\rm 4}$ in high magnetic fields,"In this study, we have performed the magnetocaloric effect and the specific
+heat measurements of chromium spinel oxide HgCr$_2$O$_4$, wherein the magnetic
+Cr$^{3+}$ ions form a highly frustrated pyrochlore lattice with significant
+spin-lattice coupling. In addition to the known magnetic-field-induced phases,
+our thermodynamic measurements detect a novel quantum phase just before the
+saturation of the magnetization, which has not been expected from the classical
+theories of the pyrochlore lattice antiferromagnet with spin-lattice coupling.
+Based on recent theoretical model calculation, we discuss the possibility of a
+spin nematic state appearing for this quantum phase.",2205.00810v1
+2022-07-28,Magnetic properties of CrSnS3: A new Van der Waals ferromagnet,"We report an experimental discovery of CrSnS3, a new Van der Waals
+ferromagnetic (FM) with Curie temperature TC ~119K. The Curie temperature is in
+qualitative agreement of Chittari et. al. DFT prediction (TC =112.3K) for an
+Ising model with the addition of Coulomb potential. The FM ordering temperature
+in CrSnS3 is the highest among Cr-based Van der Waals materials: CrI3, CrSiTe3
+and CrGeTe3. The dc-susceptibility revealed a sharp increase at Tc (~119K)
+indicative of a first order transition; then raises to a wide maximum at AFM
+Neel temperature TN~90K.The ac-susceptibility reveals the presence of two sharp
+peaks; one close to Tc (119K) and the other at TN~90K. Ac-susceptibility
+measurements in an applied dc-magnetic field indicates that CrSnS3 undergoes
+two successive phase transitions: a sharp increase in the susceptibility
+indicates a first order PM to FM at 119K, followed by more gradual decrease at
+the onset of AFM transition at TN~90K. The magnetization isotherms below 30K
+indicates that the materials orders in an AFM state; while the magnetic
+isotherms at T >30K rises sharply to its saturated values confirming the
+ferromagnetic state.",2207.14129v1
+2022-08-22,Nonlinear transport due to magnetic-field-induced flat bands in the nodal-line semimetal ZrTe5,"The Dirac material ZrTe$_5$ at very low carrier density was recently found to
+be a nodal-line semimetal, where ultra-flat bands are expected to emerge in
+magnetic fields parallel to the nodal-line plane. Here we report that in very
+low carrier-density samples of ZrTe$_5$, when the current and the magnetic
+field are both along the crystallographic $a$ axis, the current-voltage
+characteristics presents a pronounced nonlinearity which tends to saturate in
+the ultra quantum limit. The magnetic-field dependence of the nonlinear
+coefficient is well explained by the Boltzmann theory for flat-band transport,
+and we argue that this nonlinear transport is likely due to the combined effect
+of flat bands and charge puddles, the latter appear due to very low carrier
+densities.",2208.10314v3
+2022-09-02,Magnetic phase diagram and possible Kitaev-like behavior of honeycomb-lattice antimonate Na3Co2SbO6,"Recent theoretical studies have suggested that Kitaev physics and such
+effects as formation of a mysterious spin-liquid state can be expected not only
+in RuCl3 and iridates, but also in conventional $3d$ transition metal
+compounds. Using DC and AC magnetometry, thermodynamic and $^{23}$Na nuclear
+magnetic resonance measurements (NMR) we studied such a candidate material
+Na3Co2SbO6. A full phase diagram of Na3Co2SbO6 in a wide range of magnetic
+fields and temperatures is presented. The results demonstrate transformation of
+the antiferromagnetic structure under the external magnetic field, gradual
+development of the saturation phase, as well as evidence of gapped behavior in
+certain parts of the phase diagram",2209.00846v2
+2022-10-30,Evaporation of water in a microfluidic channel under magnetic field,"The evaporation of drops of water placed at the center of long poly(methyl
+methacrylate) microfluidic channels with a rectangular cross section of 0.38
+mm2 is studied by simultaneously monitoring the shapes of two samples, one is
+in a 300 mT magnetic field, the other is in no field. A magnetic enhancement of
+the evaporation rate of up to 140 % is observed, which can be understood by
+treating the ortho and para nuclear isomers of water vapor as quasi-independent
+gasses with an ortho:para ratio in fresh vapor close to 2:3. It would take much
+longer than the 2 - 4 h duration of an experiment in the channel, for the ratio
+to approach the 3:1 equilibrium value. Magnetic field influences evaporation
+rate by equalizing the isomeric populations in the vapor phase. The atmosphere
+in the channel is saturated with water vapor yet the evaporation rate far
+exceeds that in open beakers.",2210.16962v1
+2023-02-13,Helical dynamo growth at modest versus extreme magnetic Reynolds numbers,"Understanding large-scale magnetic field growth in astrophysical objects is a
+persistent challenge. We tackle the long-standing question of how much helical
+large-scale dynamo growth occurs independent of the magnetic Reynolds number
+(Rm) in a closed volume. From modest-Rm numerical simulations, we identify a
+pre-saturation regime when the large-scale field grows independently of Rm, but
+to an Rm-dependent magnitude. For plausible magnetic spectra however, the
+analysis predicts the magnitude to be Rm-independent and substantial as
+Rm$\to\infty$. This gives renewed optimism for the relevance of closed dynamos
+and pinpoints how modest Rm and hyper-diffusive simulations can cause
+misapprehension of the Rm$\to\infty$ behavior.",2302.06042v2
+2023-02-21,Aluminium substituted yttrium iron garnet thin films with reduced Curie temperature,"Magnetic garnets such as yttrium iron garnet (Y$_3$Fe$_5$O$_{12}$, YIG) are
+widely used in spintronic and magnonic devices. Their magnetic and
+magneto-optical properties can be modified over a wide range by tailoring their
+chemical composition. Here, we report the successful growth of Al-substituted
+yttrium iron garnet (YAlIG) thin films via radio frequency sputtering in
+combination with an ex situ annealing step. Upon selecting appropriate process
+parameters, we obtain highly crystalline YAlIG films with different Al$^{3+}$
+substitution levels on both, single crystalline Y$_3$Al$_5$O$_{12}$ (YAG) and
+Gd$_3$Ga$_5$O$_{12}$ (GGG) substrates. With increasing Al$^{3+}$ substitution
+levels, we observe a reduction of the saturation magnetisation as well as a
+systematic decrease of the magnetic ordering temperature to values well below
+room temperature. YAlIG thin films thus provide an interesting material
+platform for spintronic and magnonic experiments in different magnetic phases.",2302.10517v2
+2023-09-11,Experimental realization of a high Curie temperature CoFeRuSn quaternary Heusler alloy for spintronic applications,"We synthesize CoFeRuSn equiatomic quaternary Heusler alloy using arc-melt
+technique and investigate its structural, magnetic and transport properties.
+The room temperature powder X-ray diffraction analysis reveals that CoFeRuSn
+crystallizes in cubic crystal structure with small amount of DO3 - disorder.
+The field dependence of magnetization shows non-zero but small hysteresis and
+saturation behavior up to room temperature, indicating soft ferromagnetic
+nature of CoFeRuSn. The magnetic moment estimated from the magnetization data
+is found to be 4.15 {\mu}B / f.u., which is slightly less than the expected
+Slater-Pauling rule. The deviation in the value of experimentally observed
+moment from the theoretical value might be due to small disorder in the
+crystal. The low temperature fit to electrical resistivity data show absence of
+quadratic temperature dependence of resistivity, suggesting half-metallic
+behavior of CoFeRuSn. The high Curie temperature and possible half-metallic
+behavior of CoFeRuSn make it a highly promising candidate for room temperature
+spintronic applications.",2309.05493v1
+2023-11-24,Local temperature control of magnon frequency and direction of supercurrents in a magnon Bose-Einstein condensate,"The creation of temperature variations in magnetization, and hence in the
+frequencies of the magnon spectrum in laser-heated regions of magnetic films,
+is an important method for studying Bose-Einstein condensation of magnons,
+magnon supercurrents, Bogoliubov waves, and similar phenomena. In our study, we
+demonstrate analytically, numerically, and experimentally that, in addition to
+the magnetization variations, it is necessary to consider the connected
+variations of the demagnetizing field. In case of a heat induced local minimum
+of the saturation magnetization, the combination of these two effects results
+in a local increase in the minimum frequency value of the magnon dispersion at
+which the Bose-Einstein condensate emerges. As a result, a magnon supercurrent
+directed away from the hot region is formed.",2311.14476v1
+2023-11-30,Highly sensitive magnetic properties and large linear magnetoresistance in antiferromagnetic CrxSe(0.875\lex\le1)single crystals,"CrxSe (x\le1) is a class of quasi-layered binary compounds with potential
+applications in spintronics due to its intriguing antiferromagnetic properties.
+In this work, CrxSe single crystals with high Cr content (x=0.87, 0.91 and
+0.95) were grown, and their magnetic and transport properties were investigated
+in detail. It is found that with small increase of Cr content, the N\'eel
+temperature (TN) of the samples can dramatically increase from 147 K to 257 K,
+accompanied with obvious changes in the magnetic anisotropy and hysteresis. The
+phenomena of field-induced spin-flop transitions were unveiled in these alloys,
+indicating their comparatively low anisotropy. The magnetoresistance (MR) of
+the three compounds showed positive dependence at low temperatures and
+particularly, non-saturated linear positive MR was observed in Cr0.91Se and
+Cr0.95Se, with a large value of 16.2% achieved in Cr0.91Se (10K, 9T). The
+calculated Fermi surface and MR showed that the quasi-linear MR is a product of
+carrier compensation. Our work revealed highly sensitive magnetic and transport
+properties in the Cr-Se compounds, which can lay foundation when constructing
+further antiferromagnetic spintronic devices based on them.",2311.18349v1
+2024-03-15,Granular Aluminum Parametric Amplifier for Low-Noise Measurements in Tesla Fields,"Josephson junction parametric amplifiers have become essential tools for
+microwave quantum circuit readout with minimal added noise. Even after
+improving at an impressive rate in the last decade, they remain vulnerable to
+magnetic field, which limits their use in many applications such as spin
+qubits, Andreev and molecular magnet devices, dark matter searches, etc.
+Kinetic inductance materials, such as granular aluminum (grAl), offer an
+alternative source of non-linearity with innate magnetic field resilience. We
+present a non-degenerate amplifier made of two coupled grAl resonators
+resilient to in-plane magnetic field up to 1 T. It offers 20 dB of gain close
+to the quantum limit of added noise, with a gain-bandwidth product of 28 MHz
+and -110 dBm input saturation power.",2403.10669v2
+2011-06-20,Global Simulations of Accretion Disks I: Convergence and Comparisons with Local Models,"Grid-based magnetohydrodynamic (MHD) simulations have proven invaluable for
+the study of astrophysical accretion disks. However, the fact that angular
+momentum transport in disks is mediated by MHD turbulence (with structure down
+to very small scales) raises the concern that the properties of the modeled
+accretion disks are affected by the finite numerical resolution of the
+simulation. By implementing an orbital advection algorithm into the Athena code
+in cylindrical geometry, we have performed a set of global (but unstratified)
+Newtonian disk simulations extending up to resolutions previously unattained.
+We study the convergence of these models as a function of spatial resolution
+and initial magnetic field geometry. The usual viscosity parameter ($\alpha$)
+or the ratio of thermal-to-magnetic pressure ($\beta$) are found to be poor
+diagnostics of convergence, whereas the average tilt angle of the magnetic
+field in the $(r,\phi)$-plane is a very good diagnostic of convergence. We
+suggest that this is related to the saturation of the MHD turbulence via
+parasitic modes of the magnetorotational instability. Even in the case of
+zero-net magnetic flux, we conclude that our highest resolution simulations
+(with 32-zones and 64-zones per vertical scale height) have achieved
+convergence.
+  Our global simulations reach resolutions comparable to those used in local,
+shearing box models of MHD disk turbulence. We find that the saturation
+predictors derived from local simulations correspond well to the instantaneous
+correlations between local flux and stress found in our global simulations.
+However, the conservation of magnetic flux implicit in local models is not
+realized in our global disks. Thus, the magnetic connectivity of an accretion
+disk represents physics that is truly global and cannot be captured in any
+ab-initio local model.",1106.4019v1
+2012-12-17,"M dwarf companions to white dwarfs I: relating magnetic activity, rotation and age","We make use of the largest and most homogeneous sample of white dwarf/M dwarf
+(WD/dM) binaries from the Sloan Digital Sky Survey (SDSS DR7) to investigate
+relations between magnetic activity, rotation, magnetic braking and age in M
+stars. These relations are studied separately for close WD/dM binaries that
+underwent a common envelope phase and thus contain tidally locked and hence
+rapidly rotating M dwarfs, and for wide WD/dM binaries that never interacted.
+For the wide WD/dM binary sample we find that the M dwarf activity fractions
+are significantly higher than those measured in single M stars of spectral type
+M0 to M5. We attribute this effect as a consequence of M dwarfs in wide SDSS
+WD/dM binaries being, on average, significantly younger and hence more active
+than the field M dwarf population. The measured M dwarf activity fractions in
+wide WD/dM binaries show as well a significant increase from spectral types M3
+to M5, where these low-mass stars become fully convective. This provides
+additional observational evidence for magnetic braking being less efficient
+below the fully convective boundary, in agreement with the hypothesis of fully
+convective stars having considerably longer activity lifetimes than partially
+convective stars. The M dwarfs in all our close binaries are active,
+independently of the spectral type, giving robust observational evidence for
+magnetic activity being enhanced due to fast rotation. The rotational
+velocities of the M dwarfs in our close binary sample are significantly higher
+than seen among field M dwarfs, however the strength of magnetic activity
+remains saturated at log LHalpha/Lbol approximately -3.5. This unambiguously
+confirms the M dwarf saturation-type rotation-activity relation.",1212.4189v1
+2014-02-08,A dynamo model of magnetic activity in solar-like stars with different rotational velocities,"We attempt to provide a quantitative theoretical explanation for the
+observations that Ca II H/K emission and X-ray emission from solar-like stars
+increase with decreasing Rossby number (i.e., with faster rotation). Assuming
+that these emissions are caused by magnetic cycles similar to the sunspot
+cycle, we construct flux transport dynamo models of $1M_{\odot}$ stars rotating
+with different rotation periods. We first compute the differential rotation and
+the meridional circulation inside these stars from a mean-field hydrodynamics
+model. Then these are substituted in our dynamo code to produce periodic
+solutions. We find that the dimensionless amplitude $f_m$ of the toroidal flux
+through the star increases with decreasing rotation period. The observational
+data can be matched if we assume the emissions to go as the power 3-4 of $f_m$.
+Assuming that the Babcock-Leighton mechanism saturates with increasing
+rotation, we can provide an explanation for the observed saturation of emission
+at low Rossby numbers. The main failure of our model is that it predicts an
+increase of magnetic cycle period with increasing rotation rate, which is the
+opposite of what is found observationally. Much of our calculations are based
+on the assumption that the magnetic buoyancy makes the magnetic flux tubes to
+rise radially from the bottom of the convection zone. On taking account of the
+fact that the Coriolis force diverts the magnetic flux tubes to rise parallel
+to the rotation axis in rapidly rotating stars, the results do not change
+qualitatively.",1402.1874v3
+2014-07-10,"Magnetic hyperthermia properties of nanoparticles inside lysosomes using kinetic Monte-Carlo simulations : influence of key parameters, of dipolar interactions and spatial variation of heating power","Understanding the influence of dipolar interactions in magnetic hyperthermia
+(MH) experiments is of crucial importance for a fine optimization of
+nanoparticle (NP) heating power. In this study, we use a kinetic Monte-Carlo
+algorithm to calculate hysteresis loops, so both time and temperature are
+correctly taken into account. It is demonstrated that this algorithm correctly
+reproduces the high-frequency hysteresis loop of both superparamagnetic NPs and
+ferromagnetic ones without any ad-hoc parameters. The algorithm is easily
+parallelizable so calculation on several processors decreases considerably
+calculation time. The specific absorption rate (SAR) of NPs dispersed inside
+spherical lysosomes is studied as a function of several key parameters: volume
+concentration, applied magnetic field, lysosome size, NP diameter and
+anisotropy. The influence of these parameters is illustrated and
+comprehensively explained. In summary, the effect of magnetic interactions is
+to increase the coercive field, saturation field and hysteresis area of major
+loops. However, for small amplitude magnetic field such as the ones used in MH,
+the heating power as function of concentration can increase, decrease or
+display a bell shape, depending of the relationship between the applied
+magnetic field and the coercive/saturation fields of the NPs. The hysteresis
+area is found to be well correlated to the parallel or antiparallel nature of
+the dipolar field acting on each NP. It is shown that the heating power
+increases or decreases sharply in the vicinity of the lysosome membrane. The
+amplitude of variation reaches more than one order of magnitude in certain
+conditions. Finally, implications of these various findings are discussed in
+the framework of MH optimization. It is concluded that feedbacks on specific
+points from biology experiments are required for further advance on the
+optimization of NPs for MH.",1407.2737v2
+2017-08-13,PIC Simulations of Velocity-Space Instabilities in a Decreasing Magnetic Field: Viscosity and Thermal Conduction,"We use particle-in-cell (PIC) simulations of a collisionless, electron-ion
+plasma with a decreasing background magnetic field, $B$, to study the effect of
+velocity-space instabilities on the viscous heating and thermal conduction of
+the plasma. If $B$ decreases, the adiabatic invariance of the magnetic moment
+gives rise to pressure anisotropies with $p_{||,j} > p_{\perp,j}$ ($p_{||,j}$
+and $p_{\perp,j}$ represent the pressure of species $j$ ($=i$ or $e$) parallel
+and perpendicular to the magnetic field). Linear theory indicates that, for
+sufficiently large anisotropies, different velocity-space instabilities can be
+triggered. These instabilities, which grow on scales comparable to the electron
+and ion Larmor radii, in principle have the ability to pitch-angle scatter the
+particles, limiting the growth of the anisotropies. Our PIC simulations focus
+on the nonlinear, saturated regime of the instabilities. This is done through
+the permanent decrease of the magnetic field by an imposed shear in the plasma.
+Our results show that, in the regime $2 \lesssim \beta_j \lesssim 20$ ($\beta_j
+\equiv 8\pi p_j/B^2$), the saturated ion and electron pressure anisotropies are
+controlled by the combined effect of the oblique ion firehose (OIF) and the
+fast magnetosonic/whistler (FM/W) instabilities. These instabilities grow
+preferentially on the ion Larmor radius scale, and make the ion and electron
+pressure anisotropies nearly equal: $\Delta p_e/p_{||,e} \approx \Delta
+p_i/p_{||,i}$ (where $\Delta p_j=p_{\perp,j} - p_{||,j}$). We also quantify the
+thermal conduction of the plasma by directly calculating the mean free path of
+electrons along the mean magnetic field, which we find strongly depends on
+whether $B$ decreases or increases. Our results can be applied in studies of
+low collisionality plasmas such as the solar wind, the intracluster medium, and
+some accretion disks around black holes.",1708.03926v2
+2020-07-06,Spin-canting effects in GMR sensors with wide dynamic field range,"Magnetoresistive (xMR) sensors find extensive application in science and
+industry, replacing Hall sensors in various low field environments. While there
+have been some efforts in increasing the dynamic field range of xMR sensors,
+Hall sensors remain to dominate high field applications due to their wide
+linear range. Using a perpendicular magnetized reference system and an in-plane
+free layer allows us to overcome this disadvantage of xMR sensors, and,
+furthermore, investigate spin-canting effects in interlayer exchange coupled
+perpendicular synthetic antiferromagnets (p-SAF). We created p-SAFs with
+exchange coupling fields of up to 10 kOe, based on magnetic Co/Pt multilayer
+systems. The p-SAFs are either designed as ""single"" p-SAFs, where two Co/Pt
+multilayers are interlayer exchange coupled via a 4 {\AA} thick Ru spacer, or
+as ""double"" p-SAFs, where an additional Co layer is interlayer exchange coupled
+to the top multilayer. These p-SAFs are used for giant magnetoresistance (GMR)
+sensors with wide dynamic field range. By using a p-SAF as the reference system
+and employing an in-plane magnetic layer as the GMR's free layer, the linear
+range can be effectively increased limited only by the p-SAF's switching
+fields. Additionally, the magnetic anisotropy of the in-plane free layer is
+fully controlled, which allows saturation fields by design. Different
+configurations were investigated, ranging from free layer magnetic saturation
+at lower to far higher fields than the p-SAF's switching fields. We can show
+through micromagnetic simulations that certain GMR transfer curves are
+dominated by spin-canting effects in the interlayer exchange coupled reference
+system. Finally, our simulation results lay out the correlation of the p-SAF's
+design parameters and its magnetization reversal behavior.",2007.02640v1
+2021-08-27,"Jets in Magnetically Arrested Hot Accretion Flows: Geometry, Power and Black Hole Spindown","We present the results of nine simulations of radiatively-inefficient
+magnetically arrested disks (MADs) across different values of the black hole
+spin parameter $a_*$: $-0.9$, $-0.7$, $-0.5$, $-0.3$, 0, 0.3, 0.5, 0.7, and
+0.9. Each simulation was run up to $t \gtrsim 100,000\,GM/c^3$ to ensure disk
+inflow equilibrium out to large radii. We find that the saturated magnetic flux
+level, and consequently also jet power, of MAD disks depends strongly on the
+black hole spin, confirming previous results. Prograde disks saturate at a much
+higher relative magnetic flux and have more powerful jets than their retrograde
+counterparts. MADs with spinning black holes naturally launch jets with
+generalized parabolic profiles whose widths vary as a power of distance from
+the black hole. For distances up to $100\;GM/c^2$, the power-law index is $k
+\approx 0.27-0.42$. There is a strong correlation between the disk-jet geometry
+and the dimensionless magnetic flux, resulting in prograde systems displaying
+thinner equatorial accretion flows near the black hole and wider jets, compared
+to retrograde systems. Prograde and retrograde MADs also exhibit different
+trends in disk variability: accretion rate variability increases with
+increasing spin for $a_*>0$ and remains almost constant for $a_*\lesssim 0$,
+while magnetic flux variability shows the opposite trend. Jets in the MAD state
+remove more angular momentum from black holes than is accreted, effectively
+spinning down the black hole. If powerful jets from MAD systems in Nature are
+persistent, this loss of angular momentum will notably reduce the black hole
+spin over cosmic time.",2108.12380v2
+2023-06-26,Large saturation moment and high ferromagnetic transition temperature in a structurally disordered inverse Heusler alloy Fe2RuGe,"We report the successful synthesis of a new 4$d$ based polycrystalline
+inverse Heusler alloy Fe$_2$RuGe by an arc melting process and have studied in
+detail its structural, magnetic and transport properties complemented with
+first principle calculations. X-ray and neutron diffraction, Extended X-ray
+Absorption Fine Structure and $^{57}$Fe M\""{o}ssbauer spectroscopic studies
+confirm the single phase nature of the system where the Fe and Ru atoms are
+randomly distributed in the 4$c$ and 4$d$ Wyckoff positions in a ratio close to
+50:50. The formation of the disordered structure is also confirmed by the
+theoretical energy minimization calculation. Despite the random cross-site
+disorder of Fe and Ru atoms, magnetic measurements suggest not only a high
+Curie temperature of $\sim$860\,K, but also a large saturation magnetic moment
+$\sim$4.9\,$\mu_B$ per formula unit at 5\,K, considerably exceeding the
+theoretical limit (4\,$\mu_B$ per formula unit) predicted by the Slater-Pauling
+rule. Only a few Fe-based inverse Heusler alloys are known to exhibit such high
+Curie temperatures. Neutron diffraction analysis coupled with the isothermal
+magnetization value indicates that the magnetic moments in Fe$_2$RuGe are
+associated with Fe-atoms only, which is also confirmed by M\""ossbauer
+spectrometry. Interestingly, in comparison to the cubic or hexagonal phase of
+the parent compound, Fe$_3$Ge, the Curie temperature of Fe$_2$RuGe has
+increased significantly despite the substitution of the nonmagnetic, yet
+isoelectronic element Ru in this structurally disordered compound. Our
+theoretical calculation reveals that the large Fe moment ($\sim2.8\mu_B$/Fe) on
+the 4$b$ site can be attributed to a charge transfer from this Fe site towards
+its Ru neighbours. Such a substantial increase in magnetic moment due to
+electron charge transfer has not previously been reported in a Heusler alloy
+system.",2306.14831v1
+2023-08-25,High-susceptibility nanoparticles for micro-inductor core materials,"According to the laws of magnetism, the shape of magnetically soft objects
+limits the effective susceptibility. For example, spherical soft magnets cannot
+display an effective susceptibility larger than 3. Although true for
+macroscopic multi-domain magnetic materials, we show that magnetic
+nanoparticles in a single-domain state do not suffer from this limitation. This
+is a consequence of the particle moment being forced to saturation by the
+predominance of exchange forces, and only allowed to rotate coherently in
+response to thermal and/or applied fields. We apply statistical mechanics to
+determine the static and dynamic susceptibility of single-domain particles as a
+function of size, temperature and material parameters. Our calculations reveal
+that spherical single-domain particles with large saturation magnetisation and
+small magneto-crystalline anisotropy, e.g. FeNi particles, can have very a
+large susceptibility of 200 or more. We further show that susceptibility and
+losses can be tuned by particle easy axis alignment with the applied field in
+case of uniaxial anisotropy, but not for particles with cubic anisotropy. Our
+model is validated experimentally by comparison with measurements on
+nanocomposites containing spherical 11$\pm$3 nm $\gamma$-Fe$_2$O$_3$ particles
+up to 45 vol% finely dispersed in a polymer matrix. In agreement with the
+calculations for this specific material, the measured susceptibility of the
+composites is up to 17 ($\gg$3) and depends linearly on the volume fraction of
+particles. Based on these results, we predict that nanocomposites of 30 vol% of
+superparamagnetic FeNi particles in an insulating non-magnetic matrix can have
+a sufficiently large susceptibility to be used as micro-inductor core materials
+in the MHz frequency range, while maintaining losses below state-of-the-art
+ferrites.",2308.13407v2
+2006-12-13,X-ray Emission from T Tauri Stars and the Role of Accretion: Inferences from the XMM-Newton Extended Survey of the Taurus Molecular Cloud,"T Tau stars display different X-ray properties depending on whether they are
+accreting (classical T Tau stars; CTTS) or not (weak-line T Tau stars; WTTS).
+We use data from the XMM-Newton Extended Survey of the Taurus Molecular Cloud
+(XEST) to study differences in X-ray properties between CTTS and WTTS. We
+perform correlation and regression analysis between X-ray parameters and
+stellar properties. We confirm the existence of a X-ray luminosity (Lx) vs.
+mass (M) relation, Lx ~ M^(1.69 +/- 0.11), but this relation is a consequence
+of X-ray saturation and a mass vs. bolometric luminosity (L*) relation for the
+TTS with an average age of 2.4 Myr. X-ray saturation indicates Lx = const L*,
+although the constant is different for the two subsamples: const = 10^(-3.73
++/- 0.05) for CTTS and const = 10^(-3.39 +/- 0.06) for WTTS. Given a similar L*
+distribution of both samples, the X-ray luminosity function also reflects a
+real X-ray deficiency in CTTS, by a factor of ~ 2 compared to WTTS. The average
+electron temperatures Tav are correlated with Lx in WTTS but not in CTTS; CTTS
+sources are on average hotter than WTTS sources. The most fundamental
+properties are the two saturation laws, indicating suppressed Lx for CTTS. We
+speculate that some of the accreting material in CTTS is cooling active regions
+to temperatures that may not significantly emit in the X-ray band, and if they
+do, high-resolution spectroscopy may be required to identify lines formed in
+such plasma, while CCD cameras do not detect these components. The similarity
+of the Lx vs. Tav dependencies in WTTS and main-sequence stars as well as their
+similar X-ray saturation laws suggests similar physical processes for the hot
+plasma, i.e., heating and radiation of a magnetic corona.",0612338v1
+2022-05-26,X-ray emission of contact binary variables within 1 kpc,"By assembling the largest sample to date of X-ray emitting EW-type binaries
+(EWXs), we carried out correlation analyses for the X-ray luminosity
+log$L_{\textrm{X}}$, and X-ray activity level
+log($L_{\textrm{X}}$/$L_{\textrm{bol}}$) versus the orbital period $P$ and
+effective temperature $T_{\rm eff}$. We find strong $P$-log$L_{\textrm{X}}$ and
+$P$-log($L_{\textrm{X}}$/$L_{\textrm{bol}}$) correlations for EWXs with $P$ <
+0.44 days and we provide the linear parametrizations for these relations, on
+the basis of which the orbital period can be treated as a good predictor for
+log$L_{\textrm{X}}$ and log($L_{\textrm{X}}$/$L_{\textrm{bol}}$). The
+aforementioned binary stellar parameters are all correlated with
+log$L_{\textrm{X}}$, while only $T_{\rm eff}$ exhibits a strong correlation
+with log($L_{\textrm{X}}$/$L_{\textrm{bol}}$). Then, EWXs with higher
+temperature show lower X-ray activity level, which could indicate the thinning
+of the convective area related to the magnetic dynamo mechanism. The total
+X-ray luminosity of an EWX is essentially consistent with that of an X-ray
+saturated main sequence star with the same mass as its primary, which may imply
+that the primary star dominates the X-ray emission. The monotonically
+decreasing $P$-log($L_{\textrm{X}}$/$L_{\textrm{bol}}$) relation and the short
+orbital periods indicate that EWXs could all be in the X-ray saturated state,
+and they may inherit the changing trend of the saturated X-ray luminosities
+along with the mass shown by single stars. For EWXs, the orbital period, mass,
+and effective temperature increase in concordance. We demonstrate that the
+period $P=0.44$ days corresponds to the primary mass of $\sim1.1 \rm M_\odot$,
+beyond which the saturated X-ray luminosity of single stars will not continue
+to increase with mass. This explains the break in the positive
+$P$-log$L_{\textrm{X}}$ relation for EWXs with $P>0.44$ days.",2205.13210v1
+2006-10-27,Magnetorotational collapse of massive stellar cores to neutron stars: Simulations in full general relativity,"We study magnetohydrodynamic (MHD) effects arising in the collapse of
+magnetized, rotating, massive stellar cores to proto-neutron stars (PNSs). We
+perform axisymmetric numerical simulations in full general relativity with a
+hybrid equation of state. The formation and early evolution of a PNS are
+followed with a grid of 2500 x 2500 zones, which provides better resolution
+than in previous (Newtonian) studies. We confirm that significant differential
+rotation results even when the rotation of the progenitor is initially uniform.
+Consequently, the magnetic field is amplified both by magnetic winding and the
+magnetorotational instability (MRI). Even if the magnetic energy E_EM is much
+smaller than the rotational kinetic energy T_rot at the time of PNS formation,
+the ratio E_EM/T_rot increases to 0.1-0.2 by the magnetic winding. Following
+PNS formation, MHD outflows lead to losses of rest mass, energy, and angular
+momentum from the system. The earliest outflow is produced primarily by the
+increasing magnetic stress caused by magnetic winding. The MRI amplifies the
+poloidal field and increases the magnetic stress, causing further angular
+momentum transport and helping to drive the outflow. After the magnetic field
+saturates, a nearly stationary, collimated magnetic field forms near the
+rotation axis and a Blandford-Payne type outflow develops along the field
+lines. These outflows remove angular momentum from the PNS at a rate given by
+\dot{J} \sim \eta E_EM C_B, where \eta is a constant of order 0.1 and C_B is a
+typical ratio of poloidal to toroidal field strength. As a result, the rotation
+period quickly increases for a strongly magnetized PNS until the degree of
+differential rotation decreases. Our simulations suggest that rapidly rotating,
+magnetized PNSs may not give rise to rapidly rotating neutron stars.",0610840v1
+2014-02-05,Magnetic Helicity and Large Scale Magnetic Fields: A Primer,"Magnetic fields of laboratory, planetary, stellar, and galactic plasmas
+commonly exhibit significant order on large temporal or spatial scales compared
+to the otherwise random motions within the hosting system. Such ordered fields
+can be measured in the case of planets, stars, and galaxies, or inferred
+indirectly by the action of their dynamical influence, such as jets. Whether
+large scale fields are amplified in situ or a remnant from previous stages of
+an object's history is often debated for objects without a definitive magnetic
+activity cycle. Magnetic helicity, a measure of twist and linkage of magnetic
+field lines, is a unifying tool for understanding large scale field evolution
+for both mechanisms of origin. Its importance stems from its two basic
+properties: (1) magnetic helicity is typically better conserved than magnetic
+energy; and (2) the magnetic energy associated with a fixed amount of magnetic
+helicity is minimized when the system relaxes this helical structure to the
+largest scale available. Here I discuss how magnetic helicity has come to help
+us understand the saturation of and sustenance of large scale dynamos, the need
+for either local or global helicity fluxes to avoid dynamo quenching, and the
+associated observational consequences. I also discuss how magnetic helicity
+acts as a hindrance to turbulent diffusion of large scale fields, and thus a
+helper for fossil remnant large scale field origin models in some contexts. I
+briefly discuss the connection between large scale fields and accretion disk
+theory as well. The goal here is to provide a conceptual primer to help the
+reader efficiently penetrate the literature.",1402.0933v2
+2019-04-29,Magnetic fields in M dwarfs from the CARMENES survey,"M dwarfs are known to generate the strongest magnetic fields among
+main-sequence stars with convective envelopes, but the link between the
+magnetic fields and underlying dynamo mechanisms, rotation, and activity still
+lacks a consistent picture. In this work we measure magnetic fields from the
+high-resolution near-infrared spectra taken with the CARMENES radial-velocity
+planet survey in a sample of 29 active M dwarfs and compare our results against
+stellar parameters. We use the state-of-the-art radiative transfer code to
+measure total magnetic flux densities from the Zeeman broadening of spectral
+lines and filling factors. We detect strong kG magnetic fields in all our
+targets. In 16 stars the magnetic fields were measured for the first time. Our
+measurements are consistent with the magnetic field saturation in stars with
+rotation periods P<4d. The analysis of the magnetic filling factors reveal two
+different patterns of either very smooth distribution or a more patchy one,
+which can be connected to the dynamo state of the stars and/or stellar mass.
+Our measurements extend the list of M dwarfs with strong surface magnetic
+fields. They also allow us to better constrain the interplay between the
+magnetic energy, stellar rotation, and underlying dynamo action. The high
+spectral resolution and observations at near-infrared wavelengths are the
+beneficial capabilities of the CARMENES instrument that allow us to address
+important questions about the stellar magnetism.",1904.12762v1
+2021-11-23,Magnetism in Metastable and Annealed Compositionally Complex Alloys,"Compositionally complex materials (CCMs) present a potential paradigm shift
+in the design of magnetic materials. These alloys exhibit long-range structural
+order coupled with limited or no chemical order. As a result, extreme local
+environments exist with a large opposing magnetic energy term, which can
+manifest large changes in the magnetic behavior. In the current work, the
+magnetic properties of (Cr, Mn, Fe, Ni) alloys are presented. These materials
+were prepared by room-temperature combinatorial sputtering, resulting in a
+range of compositions with a single BCC structural phase and no chemical
+ordering. The combinatorial growth technique allows CCMs to be prepared outside
+of their thermodynamically stable phase, enabling the exploration of otherwise
+inaccessible order. The mixed ferromagnetic and antiferromagnetic interactions
+in these alloys causes frustrated magnetic behavior, which results in an
+extremely low coercivity (<1 mT), which increases rapidly at 50 K. At low
+temperatures, the coercivity achieves values of nearly 500 mT, which is
+comparable to some high-anisotropy magnetic materials. Commensurate with the
+divergent coercivity is an atypical drop in the temperature dependent
+magnetization. These effects are explained by a mixed magnetic phase model,
+consisting of ferro-, antiferro , and frustrated magnetic regions, and are
+rationalized by simulations. A machine-learning algorithm is employed to
+visualize the parameter space and inform the development of subsequent
+compositions. Annealing the samples at 600 {\deg}C orders the sample, more-than
+doubling the Curie temperature and increasing the saturation magnetization by
+as much as 5x. Simultaneously, the large coercivities are suppressed, resulting
+in magnetic behavior that is largely temperature independent over a range of
+350 K.",2111.12188v1
+2022-08-23,Nearby galaxies in the LOFAR Two-metre Sky Survey II. The magnetic field-gas relation,"Context. Magnetic fields are key to understand galaxy evolution, regulating
+stellar feedback and star formation in galaxies. Aims. We probe the origin of
+magnetic fields in late-type galaxies, measuring magnetic field strengths,
+exploring whether magnetic fields are only passive constituents of the
+interstellar medium, or whether they are active constituents being part of the
+local energy equilibrium. Methods. We measure equipartition magnetic field
+strengths in 39 galaxies from LoTSS-DR2 using LOFAR observations at 144 MHz
+with 6 arcsec angular resolution which (0.1-0.7 kpc). For a subset of 9
+galaxies, we obtain atomic and molecular mass surface densities using HI and
+CO(2-1) data, from the THINGS and HERACLES surveys, respectively. These data
+are at 13 arcsec angular resolution, which corresponds to 0.3-1.2 kpc at the
+distances of our galaxies. We measure kinetic energy densities using HI and CO
+velocity dispersions. Results. We found a mean magnetic field strength of
+3.6-12.5 $\mu$G with a mean of $7.9 \pm 2.0$ $\mu$G across the full sample. The
+magnetic field strength has the tightest and steepest relation with the total
+gas surface density with $B\propto \Sigma_{\rm HI+H2}^{0.309\pm0.006}$. The
+relation with the star-formation rate surface density and molecular gas surface
+density has significantly flatter slopes. After accounting for the influence of
+cosmic-ray transport, we found an even steeper relation of $B\propto
+\Sigma_{\rm HI+H2}^{0.393\pm0.009}$. Conclusions. These results suggest that
+the magnetic field is regulated by a $B$-$\rho$ relation, which has its origin
+in the saturation of the small-scale dynamo. This is borne out by an agreement
+of kinetic and magnetic energy densities although local deviations do exist in
+particular in areas of high kinetic energy densities where the magnetic field
+is sub-dominant.",2208.11068v1
+2010-04-13,Magnetic properties of Fe3O4 nanoparticles coated with oleic and dodecanoic acids,"Magnetic nanoparticles (NP) of magnetite (Fe3O4) coated with oleic acid (OA)
+and dodecanoic acid (DA) were synthesized and investigated through Transmission
+Electron Microscopy (TEM),magnetization M, and ac magnetic susceptibility
+measurements. The OA coated samples were produced with different magnetic
+concentrations (78, 76, and 65%) and the DA sample with 63% of Fe3O4. Images
+from TEM indicate that the NP have a nearly spherical geometry and mean
+diameter ~ 5.5 nm. Magnetization measurements, performed in zero field cooled
+(ZFC) and field cooled (FC) processes under different external magnetic fields
+H, exhibited a maximum at a given temperature TB in the ZFC curves, which
+depends on the NP coating (OA or DA), magnetite concentration, and H. The
+temperature TB decreases monotonically with increasing H and, for a given H,
+the increase in the magnetite concentration results in an increase of TB. The
+observed behavior is related to the dipolar interaction (DI) between NP which
+seems to be an important mechanism in all samples studied. This is supported by
+the results of the ac magnetic susceptibility Xac measurements, where the
+temperature in which X' peaks for different frequencies follows the
+Vogel-Fulcher model, a feature commonly found in systems with dipolar
+interactions. Curves of H vs. TB/TB(H=0) for samples with different coatings
+and magnetite concentrations collapse into a universal curve, indicating that
+the qualitative magnetic behavior of the samples may be described by the NP
+themselves, instead of the coating or the strength of the dipolar interaction.
+Below TB, M vs. H curves show a coercive field (HC) that increases
+monotonically with decreasing temperature. The saturation magnetization (MS)
+follows the Bloch's law and values of MS at room temperature as high as 78
+emu/g were estimated, a result corresponding to ~80% of the bulk value. The
+overlap of M/MS vs. H/T curves for a given sample and the low HC at high
+temperatures suggest superparamagnetic behavior in all samples studied. The
+overlap of M/MS vs. H curves at constant temperature for different samples
+indicates that the NP magnetization behavior is preserved, independently of the
+coating and magnetite concentration.",1004.2231v1
+2012-08-03,"Spin dynamics, short-range order and superparamagnetism in superconducting ferromagnet RuSr2Gd1.4Ce0.6Cu2O10-δ","We report structural, detailed DC and linear/non-linear AC, isothermal and
+thermoremanent magnetization study of the rutheno-cuprate superconducting
+ferromagnet RuSr2Gd1.4Ce0.6Cu2O10-{\delta} (GdRu-1222). Structural analysis, by
+employing Rietveld refinement of X-ray diffraction pattern, reveals that
+GdRu-1222 crystallizes in tetragonal phase with I4/mmm space group. GdRu-1222
+is a reported superconducting ferromagnet with Ru spins magnetic ordering at
+around 110 K and superconductivity below 40 K in Cu-O2 planes. Detailed
+linear/non-linear first and higher order harmonic of AC susceptibility studies
+unveiled the complex magnetism of GdRu-1222. A frequency dependent cusp is
+observed in AC susceptibility ({\chi}ac) vs. T measurements. The change in cusp
+position with applied frequency followed the well known Vogel-Fulcher law,
+which is a feature to describe a spin-glass (SG) system with possibility of
+embedded homogeneous/non-homogeneous magnetically interacting/non-interacting
+ferromagnetic clusters. Such an interpretation is also supported by
+thermoremanent magnetization (TRM) study at T = 60 K. Detailed interpretation
+of AC magnetization results revealed the formation of magnetic (ferromagnetic)
+homogenous/non-homogenous clusters of different sizes embedded in spin-glass
+(SG) matrix. The magnetization vs. applied field loops do not saturate, even at
+high applied fields (50 kOe), resulting in the short-range magnetic ordering in
+the system, which causes the formation of clusters that freeze at low
+temperatures. Temperature variation of first- and third-order susceptibility
+harmonics show good agreement with Wohlfarth's model (WM), leading to the
+superparamagnetism (SPM) state. Detailed magnetization (DC and AC both) results
+and their analysis helped in explaining the temperature dependent magnetism of
+the GdRu-1222 system.",1208.0760v2
+2015-11-11,Polarization of Magnetic Dipole Emission and Spinning Dust Emission from Magnetic Nanoparticles,"Magnetic dipole emission (MDE) from interstellar magnetic nanoparticles is an
+important Galactic foreground in the microwave frequencies, and its
+polarization level may pose great challenges for achieving reliable
+measurements of cosmic microwave background (CMB) B-mode signal. To obtain
+theoretical constraints on the polarization of MDE, we first compute the degree
+of alignment of big silicate grains incorporated with magnetic inclusions. We
+find that, in realistic conditions of the interstellar medium, thermally
+rotating big grains with magnetic inclusions are weakly aligned and achieve
+{\it alignment saturation} when the magnetic alignment rate becomes much faster
+than the rotational damping rate. We then compute the degree of alignment for
+free-flying magnetic nanoparticles, taking into account various interaction
+processes of grains with the ambient gas and radiation field, including neutral
+collisions, ion collisions, and infrared emission. We find that the rotational
+damping by infrared emission can significantly decrease the degree of alignment
+of small particles from the saturation level, whereas the excitation by ion
+collisions can enhance the alignment of ultrasmall particles. Using the
+computed degrees of alignment, we predict the polarization level of MDE from
+free-flying magnetic nanoparticles to be rather low. Such a polarization level
+is within the upper limits measured for anomalous microwave emission (AME),
+which indicates that MDE from free-flying iron particles may not be ruled out
+as a source of AME. We also quantify spinning dust emission from free-flying
+iron nanoparticles with permanent magnetic moments and find that its emissivity
+is one order of magnitude lower than that from spinning polycyclic aromatic
+hydrocarbons (PAHs). Finally, we compute the polarization spectra of spinning
+dust emission from PAHs for the different interstellar magnetic fields.",1511.03691v1
+2017-01-05,Effect of single-particle magnetostriction on the shear modulus of compliant magnetoactive elastomers,"The influence of an external magnetic field on the static shear strain and
+the effective shear modulus of a magnetoactive elastomer (MAE) is studied
+theoretically in the framework of a recently introduced approach to the
+single-particle magnetostriction mechanism [V. M. Kalita et al, Phys. Rev. E
+93, 062503 (2016)]. The planar problem of magnetostriction in an MAE with soft
+magnetic inclusions in the form of a thin disk (platelet) having the magnetic
+anisotropy in the plane of this disk is solved analytically. An external
+magnetic field acts with torques on magnetic filler particles, creates
+mechanical stresses in the vicinity of inclusions, induces shear strain and
+increases the effective shear modulus of these composite materials. It is shown
+that the largest effect of the magnetic field on the effective shear modulus
+should be expected in MAEs with soft elastomer matrices, where the shear
+modulus of the matrix is less than the magnetic anisotropy constant of
+inclusions. It is derived that the effective shear modulus is non-linearly
+dependent on the external magnetic field and approaches the saturation value in
+magnetic fields exceeding the field of particle anisotropy. It is shown that
+model calculations of the effective shear modulus correspond to a
+phenomenological definition of effective elastic moduli and magnetoelastic
+coupling constants. Obtained theoretical results compare well with known
+experimental data. Determination of effective elastic coefficients in MAEs and
+their dependence on magnetic field is discussed. The concentration dependence
+of the effective shear modulus at higher filler concentrations has been
+estimated using the method of Pad\'e approximants, which correctly predicts
+that both the absolute and relative changes of the magnetic-field dependent
+effective shear modulus will significantly increase with the growing
+concentration of filler particles.",1701.01305v1
+2021-09-29,The relationship between bipolar magnetic regions and their sunspots,"The relationship between bipolar magnetic regions (BMRs) and their sunspots
+is an important property of the solar magnetic field, but it is not well
+constrained. One consequence is that it is a challenge for surface flux
+transport models (SFTMs) based on sunspot observations to determine the details
+of BMR emergence, which they require as input, from such data. We aimed to
+establish the relationship between the amount of magnetic flux in newly emerged
+BMRs and the area of the enclosed sunspots. Earlier attempts to constrain BMR
+magnetic flux were hindered by the fact that there is no proper database of the
+magnetic and physical properties of newly emerged BMRs currently available. We
+made use of the empirical model of the relationship between the disc-integrated
+facular and network magnetic flux and the total surface coverage by sunspots
+reported in a recent study. The structure of the model is such that it enabled
+us to establish, from these disc-integrated quantities, an empirical
+relationship between the magnetic flux and sunspot area of individual newly
+emerged BMRs, circumventing the lack of any proper BMR database. Applying the
+constraint on BMR magnetic flux derived here to an established SFTM retained
+its ability to replicate various independent datasets and the correlation
+between the model output polar field at the end of each cycle and the observed
+strength of the following cycle. The SFTM output indicates that facular and
+network magnetic flux rises with increasing sunspot magnetic flux at a slowing
+rate such that it appears to gradually saturate, analogous to earlier studies.
+The activity dependence of the ratio of facular and network flux to sunspot
+flux is consistent with the findings of recent studies: although the Sun is
+faculae-dominated, it is only marginally so as facular and network brightening
+and sunspot darkening appear to be closely balanced.",2109.14313v1
+2022-01-12,Magneto-transport and magnetic textures in Ho/FeCoGd/β-W multilayers,"The enhancement of interfacial Dzyaloshinskii-Moriya Interaction (DMI) in
+magnetic multilayers results in the stabilization of topological spin textures
+like chiral domain walls and skyrmions. Here we report on the evaluation of
+interface-driven magnetic interactions in a uniquely designed multilayer where
+each magnetic layer of two AFM coupled sublattices of 3d and 4f moments is
+sandwiched between the layers of \beta-tungsten and holmium whose spin Hall
+angles are large but opposite in sign. The atomic and magnetic periodicity of
+these multilayers is established by polarized neutron reflectivity measurements
+and the presence of a labyrinth domain spin texture of zero remanence with
+x-ray photoelectron microscopy. Measurements of the Hall resistivity
+(\rho_{xy}(T, H)) together with static magnetization (M(T,H)) over a broad
+range of temperature (T) and magnetic field (H) indicate impending compensation
+between 3d and 4f sublattices at T>350 K. These multilayers are characterized
+by a small (0.04 %) but positive magnetoresistance indicative of interface
+enhance scattering and a large (40 n\Omega.m) and negative anomalous
+\rho_{xy}(T,H) which results from a parallel alignment of 4f moments with the
+external magnetic field. No distinct scaling is seen between \rho_{xy}(T,H),
+\rho_{xx}(T, H) and M(T,H) at temperatures above 200K where the magnetization
+develops out-of-plane anisotropy. The field scans of \rho_{xy} at T>200K show a
+distinct cusp in the vicinity of magnetic saturation. These Hall data have been
+analyzed in the framework of a model where a distinct topological contribution
+to \rho_{xy} rides over the anomalous Hall resistivities of the 3d and 4f
+magnetic sublattices. It is suggested that this apparent topological effect
+results from an interfacial DMI and dominates \rho_{xy}(T,H) in the temperature
+regime where the 3d and 4f lattices are nearly compensated.",2201.04696v1
+1998-02-13,Induced Raman Scattering in Pulsar Magnetospheres,"It is shown that induced Raman scattering of electromagnetic waves in the
+strongly magnetized electron-positron plasma of pulsar magnetosphere may be
+important for wave propagation and as an effective saturation mechanism for
+electromagnetic instabilities. The frequencies, at which strong Raman
+scattering occurs in the outer parts of magnetosphere, fall into the observed
+radio band. The typical threshold intensities for the strong Raman scattering
+are of the order of the observed intensities, implying that pulsar
+magnetosphere may be optically thick to Raman scattering of electromagnetic
+waves.",9802195v1
+1996-07-02,Phase separation in the one-dimensional Hubbard model,"The Hartree-Fock ground-state phase diagram of the one-dimensional Hubbard
+model is calculated in the $\mu-U$ plane, restricted to phases with no charge
+density modulation, extending the results presented in cond-mat/9511116. This
+allows antiferromagnetism, saturated ferromagnetism, spiral spin density waves
+and a collinear structure with unit cell $\uparrow \uparrow \downarrow
+\downarrow$. The spiral phase is unstable against phase separation near
+quarter-, half- and three-quarter-filling. For large $U$ this occurs at hole
+(or electron) doping of $(3t/\pi^{2}U)^{1/3}$ from half filling.",9607011v1
+1998-08-10,Instability of antiferromagnetic magnons in strong fields,"We predict that spin-waves in an ordered quantum antiferromagnet (AFM) in a
+strong magnetic field become unstable with respect to spontaneous two-magnon
+decays. At zero temperature, the instability occurs between the threshold field
+$H^*$ and the saturation field $H_c$. As an example, we investigate the
+high-field dynamics of a Heisenberg antiferromagnet on a square lattice and
+show that the single-magnon branch of the spectrum disappears in the most part
+of the Brillouin zone.",9808100v2
+1999-03-15,Giant Mutual Proximity Effects in Ferromagnetic/Superconducting Nanostructures,"A strong mutual influence of superconductors (S) and ferromagnetic (F)
+conductors in hybrid F/S (Ni/Al) nanostructures is observed. The magnitude of a
+proximity-induced conductance on the F-side is more than two orders larger than
+that predicted by theory. Re-entrance of the superconductors to the normal
+state reciprocated by changes on the F-side has been found in low applied
+magnetic fields with new peaks in the differential resistance as an effect of
+the saturation magnetisation. An analysis has been developed providing a base
+for a numerical description of the system. PACS numbers: 74.50.+r, 74.80.Fp,
+85.30St",9903237v1
+1999-05-08,H_c_3 for a thin-film superconductor with a ferromagnetic dot,"We investigate the effect of a ferromagnetic dot on a thin-film
+superconductor. We use a real-space method to solve the linearized
+Ginzburg-Landau equation in order to find the upper critical field, H_c_3. We
+show that H_c_3 is crucially dependent on dot composition and geometry, and may
+be significantly greater than H_c_2. H_c_3 is maximally enhanced when (1) the
+dot saturation magnetization is large, (2) the ratio of dot thickness to dot
+diameter is of order one, and (3) the dot thickness is large.",9905107v1
+2000-06-27,Energy separation of single-particle and continuum states in a S=1/2 weakly-coupled chains antiferromagnet,"Inelastic neutron scattering is used to study transverse-polarized magnetic
+excitations in the quasi-one-dimensional S=1/2 antiferromagnet BaCu_2Si_2O_7,
+where the saturation value for the N\'eel order parameter is $m_0=0.12 \mu_{\rm
+B}$ per spin. At low energies the spectrum is totally dominated by
+resolution-limited spin wave-like excitations. An excitation continuum sets in
+above a well-defined threshold frequency. Experimental results are discussed in
+the context of current theories for weakly-interacting quantum half-integer
+spin chains.",0006426v1
+2000-12-10,Out-of-Equilibrium Kondo Effect: Response to Pulsed Fields,"The current in response to a rectangular pulsed bias potential is calculated
+exactly for a special point in the parameter space of the nonequilibrium Kondo
+model. Our simple analytical solution shows the all essential features
+predicted by the noncrossing approximation, including a hierarchy of time
+scales for the rise, saturation, and fall-off of the current; current
+oscillations with a frequency of eV/hbar; and the instantaneous reversal of the
+fall-off current for certain pulse lengths. Rich interference patterns are
+found for a nonzero magnetic field (either dc or pulsed), with several
+underlying time scales. These features should be observable in ultra small
+quantum dots.",0012163v1
+2001-02-23,Pressure dependence of the spin dynamics around a quantum critical point : An inelastic neutron scattering study of Ce0.87La0.13Ru2Si2,"Inelastic neutron scattering experiments performed on a single crystal of the
+antiferromagnetic compound Ce$_{0.87}$La$_{0.13}$Ru$_{2}$Si$_{2}$ under applied
+pressures of up to 5 kbar are reported. A quantum critical point is reached at
+around 2.6 kbar where long-range magnetic order disappears. The variation of
+the characteristic energy scales with respect to temperature and pressure is
+followed and found to saturate in the ordered phase.",0102427v1
+2001-04-27,Realization of Bose-Einstein condensates in lower dimensions,"Bose-Einstein condensates of sodium atoms have been prepared in optical and
+magnetic traps in which the energy-level spacing in one or two dimensions
+exceeds the interaction energy between atoms, realizing condensates of lower
+dimensionality. The cross-over into two-dimensional and one-dimensional
+condensates was observed by a change in aspect ratio and saturation of the
+release energy when the number of trapped atoms was reduced.",0104549v1
+2001-06-22,(13)C NMR investigation of the superconductor MgCNi_3 up to 800K,"We report (13)C NMR characterization of the new superconductor MgCNi_3 (He et
+al., Nature (411), 54 (2001)). We found that both the uniform spin
+susceptibility and the spin fluctuations show a strong enhancement with
+decreasing temperature, and saturate below ~50K and ~20K respectively. The
+nuclear spin-lattice relaxation rate 1/(13)T_1T exhibits typical behaviour for
+isotropic s-wave superconductivity with a coherence peak below Tc=7.0K that
+grows with decreasing magnetic field.",0106476v3
+2002-03-14,Spin dynamics in a hole-doped S=1/2 Heisenberg antiferromagnet with a disordered ground state,"Only 3% hole doping by Li is sufficient to suppress the long-range
+antiferromagnetic order in La2CuO4. Spin dynamics in such a disordered state
+was investigated with measurements of the dynamic magnetic structure factor
+S(omega,q), using cold neutron spectroscopy, for La2(Cu0.94Li0.06)O4. The
+S(omega,q) is found to sharply peak at (pi,pi), and its dynamics to be
+relaxational. Confirming theoretical expectation for the quantum disordered 2D
+S=1/2 Heisenberg antiferromagnet, the energy scale saturates at a finite value
+at low temperatures. Possible connection to the ``pseudo spin gap'' phenomenon
+observed in the NMR/NQR studies on underdoped cuprates is discussed.",0203318v1
+2002-05-01,Barkhausen Noise and Critical Scaling in the Demagnetization Curve,"The demagnetization curve, or initial magnetization curve, is studied by
+examining the embedded Barkhausen noise using the non-equilibrium, zero
+temperature random-field Ising model. The demagnetization curve is found to
+reflect the critical point seen as the system's disorder is changed. Critical
+scaling is found for avalanche sizes and the size and number of spanning
+avalanches. The critical exponents are derived from those related to the
+saturation loop and subloops. Finally, the behavior in the presence of long
+range demagnetizing fields is discussed. Results are presented for simulations
+of up to one million spins.",0205021v1
+2002-08-21,A key to room-temperature ferromagnetism in Fe-doped ZnO: Cu,"Successful synthesis of room-temperature ferromagnetic semiconductors,
+Zn$_{1-x}$Fe$_{x}$O, is reported. The essential ingredient in achieving
+room-temperature ferromagnetism in bulk Zn$_{1-x}$Fe$_{x}$O was found to be
+additional Cu doping. A transition temperature as high as 550 K was obtained in
+Zn$_{0.94}$Fe$_{0.05}$Cu$_{0.01}$O; the saturation magnetization at room
+temperature reached a value of $0.75 \mu_{\rm B}$ per Fe. Large
+magnetoresistance was also observed below $100 $K.",0208399v1
+2002-10-14,Phase diagram and influence of defects in the double perovskites,"The phase diagram of the double perovskites of the type Sr_{2-x} La_x Fe Mo
+O_6 is analyzed, with and without disorder due to antisites. In addition to an
+homogeneous half metallic ferrimagnetic phase in the absence of doping and
+disorder, we find antiferromagnetic phases at large dopings, and other
+ferrimagnetic phases with lower saturation magnetization, in the presence of
+disorder.",0210303v2
+2002-11-14,Electron Spin Polarization in Resonant Interband Tunneling Devices,"We study spin-dependent interband resonant tunneling in double-barrier
+InAs/AlSb/ GaMnSb heterostructures. We demonstrate that these structures can be
+used as spin filters utilizing spin-selective tunneling of electrons through
+the light-hole resonant channel. High densities of the spin polarized electrons
+injected into bulk InAs make spin resonant tunneling devices a viable
+alternative for injecting spins into a semiconductor. Another striking feature
+of the proposed devices is the possibility of inducing additional resonant
+channels corresponding to the heavy holes. This can be implemented by
+saturating the in-plane magnetization in the quantum well.",0211300v1
+2003-07-04,Electronic and magnetic properties of GaMnAs: Annealing effects,"The effect of short-time and long-time annealing at 250C on the conductivity,
+hole density, and Curie temperature of GaMnAs single layers and GaMnAs/InGaMnAs
+heterostructures is studied by in-situ conductivity measurements as well as
+Raman and SQUID measurements before and after annealing. Whereas the
+conductivity monotonously increases with increasing annealing time, the hole
+density and the Curie temperature show a saturation after annealing for 30
+minutes. The incorporation of thin InGaMnAs layers drastically enhances the
+Curie temperature of the GaMnAs layers.",0307102v1
+2003-07-08,"Induced currents, frozen charges and the quantum Hall effect breakdown","Puzzling results obtained from torque magnetometry in the quantum Hall effect
+(QHE) regime are presented, and a theory is proposed for their explanation.
+Magnetic moment saturation, which is usually attributed to the QHE breakdown,
+is shown to be related to the charge redistribution across the sample.",0307180v2
+2003-12-02,The Efficiency of Defect Production in Planar Superconductors and Liquid Crystals,"A recent experiment that sees the spontaneous creation of magnetic flux on
+quenching high-$T_c$ films has shown that earlier null results were a
+consequence of the lack of saturation of the Zurek-Kibble causal bounds against
+which flux density was measured. In this letter we estimate how efficient the
+production of topological charge is in planar systems, both for the
+aforementioned experiment (when flux measures topological charge) and for an
+earlier experiment on planar liquid crystals. Agreement is good.",0312082v1
+2004-03-17,Hall effect in Fe$_3$O$_4$ epitaxial thin films,"Magnetite epitaxial thin films have been prepared by pulsed laser deposition
+at 340 C on MgO and Si substrates. One key result is that the thin film
+properties are almost identical to the properties of bulk material. For 40 - 50
+nm thick films, the saturation magnetization and conductivity are respectively
+453 emu/cm^3 and 225 1/(Ohm cm) at room temperature. The Verwey transition is
+at 117 K. The Hall effect indicates an electron concentration corresponding to
+0.22 electrons per formula unit at room temperature. Normal and anomalous Hall
+effect both have a negative sign.",0403422v2
+2004-04-19,High Curie temperatures in ferromagnetic Cr-doped AlN thin films,"Al1-xCrxN thin films with $0.02\le x \le 0.1$ were deposited by reactive
+co-sputtering onto c-plane (001) sapphire. Room-temperature ferromagnetism with
+a coercive field of 85 Oe was observed in samples with chromium contents as low
+as x = 0.027 (2.7%). With increasing Cr content the mean magnetic moment is
+strongly suppressed, with a maximum saturation moment of 0.62 and 0.71 $\mu_B$
+per Cr atom at 300 and 50 K respectively. We show that the Curie temperature of
+Al1-xCrxN for x = 0.027 is greater than 900 K.",0404436v1
+2004-05-13,Magnetization reduction induced by nonlinear effects,"This letter reports the first detailed measurement of $M_z$, the component
+parallel to the effective field direction, when ferromagnets are excited by
+microwave fields at high power levels. It is found that $M_z$ drops
+dramatically at the saturation of the main resonance. Simultaneous measurements
+of $M_z$ and absorption power show that this drop corresponds to a diminution
+of the spin-lattice relaxation rate. These changes are interpreted as
+reflecting the properties of longitudinal spinwaves excited above Suhl's
+instability. Similar behavior should be expected in spinwave emission by
+currents.",0405301v3
+2004-07-23,"High Pressure Effects on Superconductivity in the beta-pyrochlore Oxides AOs2O6 (A=K, Rb, Cs)","Recently new pyrochlore oxides superconductors AOs2O6 (A=K,Rb,Cs) were found
+and we measured the pressure dependence of magnetization up to 1.2 GPa in order
+to deduce the pressure effect of Tc in the three beta-pyrochlore oxides. It is
+found that the initial pressure dependence of Tc is positive for all the
+compounds. Only KOs2O6 exhibits a saturation in Tc at 0.56 GPa and the downturn
+at higher pressure",0407610v1
+2004-08-31,Current fluctuations of an interacting quantum dot,"We calculate the counting statistics of electron transfer through an open
+quantum dot with charging interaction. A dot that is connected to leads by two
+single-channel quantum point contacts in an in-plane magnetic field is
+described by a Luttinger liquid with impurity at the Toulouse point. We find
+that the fluctuations of the current through this conductor exhibit distinctive
+interaction effects. Fluctuations saturate at high voltages, while the mean
+current increases linearly with the bias voltage. All cumulants higher than the
+second one reach at large bias a temperature independent limit.",0408666v2
+2004-10-12,High-Tc Superconductors - based Nanocomposites with Improved Intergrain Coupling and Enhanced Bulk Pinning,"Heterogeneous sonochemical synthesis was used to modify superconducting
+properties of granular YBa2Ca3CuO7-y and Bi2Sr2CaCu2O8+x. Sonication of
+liquid-powder alkane slurries produces material with enhanced intergrain
+coupling and improved current-carrying capabilities. Co-sonication with metals
+and organometallics results in highly compact nanocomposites with increased
+magnetic irreversibility. Ultrasonic irradiation of YBa2Ca3CuO7-y carried under
+partial oxygen atmosphere produces similar morphological effects and increases
+superconducting transition temperature due to effective surface saturation with
+oxygen. Detailed chemical and physical characterization of sonochemically
+prepared high-Tc nanocomposites is presented.",0410267v1
+2005-02-15,Computation of dynamical correlation functions of Heisenberg chains in a field,"We compute the momentum- and frequency-dependent longitudinal spin structure
+factor for the one-dimensional spin-1/2 $XXZ$ Heisenberg spin chain in a
+magnetic field, using exact determinant representations for form factors on the
+lattice. Multiparticle contributions are computed numerically throughout the
+Brillouin zone, yielding saturation of the sum rule to high precision.",0502365v1
+2005-09-28,Magnetic properties of antiferromagnetically coupled CoFeB/Ru/CoFeB,"This work reports on the thermal stability of two amorphous CoFeB layers
+coupled antiferromagnetically via a thin Ru interlayer. The saturation field of
+the artificial ferrimagnet which is determined by the coupling, J, is almost
+independent on the annealing temperature up to more than 300 degree C. An
+annealing at more than 325 degree C significantly increases the coercivity, Hc,
+indicating the onset of crystallization.",0509753v1
+2005-11-29,Slow spin relaxation in a highly polarized cooperative paramagnet,"We report measurements of the ac susceptibility of the cooperative paramagnet
+Tb2Ti2O7 in a strong magnetic field. Our data show the expected saturation
+maximum in chi(T) and also an unexpected low frequency dependence (< 1 Hz) of
+this peak, suggesting very slow spin relaxations are occurring. Measurements on
+samples diluted with nonmagnetic Y3+ or Lu3+ and complementary measurements on
+pure and diluted Dy2Ti2O7 strongly suggest that the relaxation is associated
+with dipolar spin correlations, representing unusual cooperative behavior in a
+paramagnetic system.",0511716v1
+2007-01-12,Spectroscopy of the parametric magnons excited by 4-wave process,"Using a Magnetic Resonace Force Microscope, we have performed ferromagnetic
+resonance (FMR) spectroscopy on parametric magnons created by 4-wave process.
+This is achieved by measuring the differential response to a small source
+modulation superimposed to a constant excitation power that drives the dynamics
+in the saturation regime of the transverse component. By sweeping the applied
+field, we observe abrupt readjustement of the total number of magnons each time
+the excitation coincides with a parametric mode. This gives rise to
+ultra-narrow peaks whose linewith is lower than $5~10^{-6}$ of the applied
+field.",0701287v1
+2007-03-07,Theory of resonant spin Hall effect,"A biref review is presented on resonant spin Hall effect, where a tiny
+external electric field induces a saturated spin Hall current in a
+2-dimensional electron or hole gas in a perpendicular magnetic field. The
+phenomenon is attributted to the energy level crossing associated with the
+spin-orbit coupling and the Zeeman splitting. We summarize recent theoretical
+development of the effect in various systems and discuss possible experiments
+to observe the effect.",0703176v1
+1999-11-11,Inertial Control of the VIRGO Superattenuator,"The VIRGO superattenuator (SA) is effective in depressing the seismic noise
+below the thermal noise level above 4 Hz. On the other hand, the residual
+mirror motion associated to the SA normal modes can saturate the dynamics of
+the interferometer locking system. This motion is reduced implementing a
+wideband (DC-5 Hz) multidimensional control (the so called inertial damping)
+which makes use of both accelerometers and position sensors and of a DSP
+system. Feedback forces are exerted by coil-magnet actuators on the top of the
+inverted pendulum. The inertial damping is successful in reducing the mirror
+motion within the requirements. The results are presented.",9911044v1
+1996-02-28,Charged Pion Polarizabilities to two Loops,"We evaluate the electric and magnetic polarizabilities of charged pions in
+the framework of chiral perturbation theory at next-to-leading order. This
+requires a two-loop evaluation of the Compton amplitude near threshold. We
+estimate the two new low-energy constants which enter the chiral expansion at
+this order with resonance saturation. The numerical results are compared with
+presently available experimental information.",9602421v1
+1994-07-28,Spontaneous Breakdown of the Lorentz Invariance and the Nambu-Goldstone Theorem,"In a class of three-dimensional abelian gauge theory the Lorentz invariance
+is spontaneously broken by dynamical generation of a magnetic field. An
+originally topologically massive photon becomes gapless, i.e. p_0=0 at {\vec
+p}=0. Indeed, the photon is the Nambu-Goldstone boson associated with the
+spontaneous breaking of the Lorentz invariance. Although symmetry generated by
+two Lorentz boost generators is broken, there seems to appear only one physical
+Nambu-Goldstone boson, namely a photon. We argue that the Ward identities in
+the Nambu-Goldstone theorem are saturated by the photon pole.",9407188v1
+1995-10-18,Discontinuous BPS spectra in $N = 2$ gauge theory,"We consider the spectrum of BPS saturated states in $N = 2$ gauge theories in
+four dimensions. This spectrum may be discontinuous across real codimension one
+submanifolds of marginal stability in the moduli space of vacua. An example,
+which can be treated with semiclassical methods in the weak coupling limit, is
+the decay of quark-soliton bound states. For a quark and a soliton of
+electric-magnetic charge vectors $Q$ and $Q^\prime$ respectively, we find that
+as the manifold of marginal stability is crossed, the number of soliton states
+changes by a factor of $2^{Q \cdot Q^\prime}$, where the dot denotes the
+symplectic product.",9510138v1
+1996-06-02,More on Four-Dimensional Extremal Black Holes,"We consider an embedding of the extremal four-dimensional
+Reissner-Nordstr\""om black hole into type $IIB$ string theory. The equivalent
+type $IIB$ configuration, in the D-brane weak-coupling picture, is a bound
+state of D1- and D5-branes threaded by fundamental type $IIB$ strings. The
+bound state involves also a NSNS solitonic 5-brane, mimicking the role of the
+Kaluza-Klein magnetic monopole. The statistical entropy derived by counting the
+degeneracy of the BPS-saturated excitations of this bound state agrees
+perfectly with the (semiclassical) Bekenstein-Hawking formula.",9605236v1
+1997-03-27,Self-dual Chern-Simons Solitons in the Planar Ferromagnet,"We consider a uniaxial planar ferromagnet coupled minimally to an Abelian
+Chern-Simons gauge field and study self-dual solitons which saturate the
+Bogomol'nyi bound. We find a rich structure of rotationally symmetric static
+soliton solutions for various uniform background charge densities. For a given
+ferromagnet material, the properties of these solitons are controlled only by
+the external magnetic field and the background charge.",9703193v1
+1998-05-18,On N=2 MQCD,"We review M-theory description of 4d N=2 SQCD. Configurations of M-theory
+fivebranes relevant to describe the moduli spaces of the Coulomb and Higgs
+branches are studied using the Taub-NUT geometry. Minimal area membranes
+related with the BPS states of N=2 SQCD are given explicitly. They almost
+saturate the BPS bounds. The deviation from the bounds is due to their boundary
+condition constrained by the fivebrane. The electric-magnetic duality at the
+baryonic branch root is also examined from the M-theory viewpoint. In this
+course, novel concepts such as creation of brane and exchange of branes in Type
+II theory are explained in the framework of M-theory.",9805107v1
+2006-01-27,Signature of directed chaos in the conductance of a nanowire,"We study the conductance of chaotic or disordered wires in a situation where
+equilibrium transport decomposes into biased diffusion and a counter-moving
+regular current. A possible realization is a semiconductor nanostructure with
+transversal magnetic field and suitably patterned surfaces. We find a
+non-trivial dependence of the conductance on the wire length which differs
+qualitatively from Ohm's law by the existence of a characteristic length scale
+and a finite saturation value.",0601058v2
+2006-05-02,Isospin violation in the vector form factors of the nucleon,"A quantitative understanding of isospin violation is an increasingly
+important ingredient for the extraction of the nucleon's strange vector form
+factors from experimental data. We calculate the isospin violating electric and
+magnetic form factors in chiral perturbation theory to leading and
+next-to-leading order respectively, and we extract the low-energy constants
+from resonance saturation. Uncertainties are dominated largely by limitations
+in the current knowledge of some vector meson couplings. The resulting bounds
+on isospin violation are sufficiently precise to be of value to on-going
+experimental studies of the strange form factors.",0605006v1
+2007-04-25,Quantized spin excitations in a ferromagnetic microstrip from microwave photovoltage measurements,"Quantized spin excitations in a single ferromagnetic microstrip have been
+measured using the microwave photovoltage technique. Several kinds of spin wave
+modes due to different contributions of the dipole-dipole and the exchange
+interactions are observed. Among them are a series of distinct dipole-exchange
+spin wave modes, which allow us to determine precisely the subtle spin boundary
+condition. A comprehensive picture for quantized spin excitations in a
+ferromagnet with finite size is thereby established. The dispersions of the
+quantized spin wave modes have two different branches separated by the
+saturation magnetization.",0704.3397v1
+2007-04-26,Spin effects in single-electron transport through carbon nanotube quantum dots,"We investigate the total spin in an individual single-wall carbon nanotube
+quantum dot with various numbers of electrons in a shell by using the ratio of
+the saturation currents of the first steps of Coulomb staircases for positive
+and negative biases. The current ratio reflects the total-spin transition that
+is increased or decreased when the dot is connected to strongly asymmetric
+tunnel barriers. Our results indicate that total spin states with and without
+magnetic fields can be traced by this method.",0704.3505v2
+2007-06-19,Proximity effects induced by a gold layer on La0.67Sr0.33MnO3 thin films,"We report about La0.67Sr0.33MnO3 single crystal manganite thin films in
+interaction with a gold capping layer. With respect to uncoated manganite
+layers of the same thickness, Au-capped 4 nm-thick manganite films reveal a
+dramatic reduction (about 185 K) of the Curie temperature TC and a lower
+saturation low-temperature magnetization M0. A sizeable TC reduction (about 60
+K) is observed even when an inert SrTiO3 layer is inserted between the gold
+film and the 4 nm-thick manganite layer, suggesting that this effect might have
+an electrostatic origin.",0706.2688v1
+2007-08-06,Multi-magnon bound states in the frustrated ferromagnetic 1D chain,"We study a one-dimensional Heisenberg chain with competing ferromagnetic
+nearest-neighbor and antiferromagnetic next-nearest neighbor interactions in
+magnetic field. Starting from the fully polarized high-field state, we
+calculate the dispersions of the lowest-lying $n$-magnon excitations and the
+saturation field (n=2,3,4). We show that the lowest-lying excitations are
+always bound multi-magnon states with a total momentum of $\pi$ except for a
+small parameter range. We argue that bose condensation of the bound $n$ magnons
+leads to novel Tomonaga-Luttinger liquids with multi-polar correlations;
+nematic and triatic ordered liquids correspond to n=2 and n=3.",0708.0701v1
+2007-11-21,"Electron-electron interaction in 2D and 1D ferromagnetic (Ga,Mn)As","We investigated the magnetotransport in high quality ferromagnetic (Ga,Mn)As
+films and wires. At low temperature the conductivity decreases with decreasing
+temperature without saturation down to 20 mK. Here we show, that the
+conductivity decrease follows a ln($T/T_0$) dependency in 2D films and a
+$-1/\sqrt{T}$ dependency in 1D wires and is independent of an applied magnetic
+field. This behavior can be explained by the theory of electron-electron
+interaction.",0711.3278v2
+2008-03-05,Vanishing Hall Coefficient in the Extreme Quantum Limit in Photocarrier-Doped SrTiO3,"We have investigated the extreme quantum limit of photogenerated electrons in
+quantum paraelectric SrTiO3. This regime is distinct from conventional
+semiconductors, due to the large electron effective mass and large lattice
+dielectric constant. At low temperature, the magnetoresistance and Hall
+resistivity saturate at high magnetic field, deviating from conventional
+behavior. As a result, the Hall coefficient vanishes on the scale of the ratio
+of the Landau level splitting to the thermal energy, indicating the essential
+role of lowest Landau level occupancy, as limited by thermal broadening.",0803.0723v1
+2008-07-02,History and results of the Riga dynamo experiments,"On 11 November 1999, a self-exciting magnetic eigenfield was detected for the
+first time in the Riga liquid sodium dynamo experiment. We report on the long
+history leading to this event, and on the subsequent experimental campaigns
+which provided a wealth of data on the kinematic and the saturated regime of
+this dynamo. The present state of the theoretical understanding of both regimes
+is delineated, and some comparisons with other laboratory dynamo experiments
+are made.",0807.0305v1
+2008-07-25,Gluon Saturation and the Formation Stage of Heavy Ion Collisions,"The high energy limit of QCD is controlled by very high energy density
+gluonic matter, the Color Glass Condensate. In the first instants of the
+collisions of two sheets of Colored Glass Condensate, a Glasma is formed with
+longitudinal flux tubes of color electric and magnetic fields. These flux tubes
+decay and might form a turbulent liquid that eventually thermalizes into a
+Quark Gluon Plasma",0807.4095v1
+2009-02-09,Modulation-free pump-probe spectroscopy of strontium atoms,"We have performed polarization spectroscopy and sub-Doppler DAVLL on the
+(5s5s) 1^S_0 -> (5s5p) 1^P_1 transition of atomic strontium. Both techniques
+generated a dispersion-type lineshape suitable for laser stabilization, without
+the need for frequency modulation. In both cases the signal is generated
+primarily by saturation effects, rather than optical pumping. The dependence of
+the amplitude and gradient on intensity and magnetic field were also
+investigated.",0902.1430v1
+2009-04-09,Chiral Anomaly and Decay of Color Electric Field,"Using the formula of chiral anomaly, we discuss the pair production of quarks
+under color electric field $\vec{E}$ without addressing explicit formula of
+quark's wavefunctions. The production is assumed to occur under the effect of
+color magnetic field $\vec{B}$ as well as the color electric field. We obtain
+the life time $t_c$ of the color electric field in the limit of $B\gg E$.
+Applying it to the glasma in high-energy heavy-ion collisions, we find that
+$t_c\simeq 10Q_s^{-1}$ with saturation momentum $Q_s$.",0904.1449v2
+2009-05-01,Self-organization of dissipationless solitons in negative refractive index materials,"General nonlinear and nonparaxial dissipative complex Helmholtz equations for
+magnetic and electric fields propagating in negative refractive index materials
+(NIMs) are derived ab initio from Maxwell equations. In order to describe
+nonconservative soliton dynamics in NIMs, such coupled equations are reduced
+into generalized Ginzburg-Landau equation. Cross-compensation between the
+excess of saturating nonlinearity, losses, and gain renders these
+self-organized solitons dissipationless and exceptionally robust. The presence
+of such solitons makes NIMs effectively dissipationless.",0905.0037v1
+2010-03-14,Direct Measurement of Cyclotron Coherence Times of High-Mobility Two-Dimensional Electron Gases,"We have observed long-lived (~30 ps) coherent oscillations of charge carriers
+due to cyclotron resonance (CR) in high-mobility two-dimensional electrons in
+GaAs in perpendicular magnetic fields using time-domain terahertz spectroscopy.
+The observed coherent oscillations were fitted well by sinusoids with
+exponentially-decaying amplitudes, through which we were able to provide direct
+and precise measures for the decay times and oscillation frequencies
+simultaneously. This method thus overcomes the CR saturation effect, which is
+known to prevent determination of true CR linewidths in high-mobility electron
+systems using Fourier-transform infrared spectroscopy.",1003.2795v1
+2010-06-08,Possible evidence for two-gap superconductivity in TiSe_2Cu_x,"We report a comprehensive TF-muSR study of TiSe_2Cu_2. The magnetic
+penetration depth was found to saturate at low temperature as expected in an
+s-wave SC. As x is increased we find that the superfluid density increases and
+the size of the superconducting gap, calculated from the temperature dependence
+of the superfluid density, is approaching the BCS value. However, for low
+values of x, the gap is smaller than the weak-coupling BCS prediction
+suggesting that two superconducting gaps are present in the sample.",1006.1630v1
+2010-08-25,Colossal negative magnetoresistance in dilute fluorinated graphene,"Adatoms offer an effective route to modify and engineer the properties of
+graphene. In this work, we create dilute fluorinated graphene using a clean,
+controlled and reversible approach. At low carrier densities, the system is
+strongly localized and exhibits an unexpected, colossal negative
+magnetoresistance. The zero-field resistance is reduced by a factor of 40 at
+the highest field of 9 T and shows no sign of saturation. Unusual ""staircase""
+field dependence is observed below 5 K. The magnetoresistance is highly
+anisotropic. We discuss possible origins, considering quantum interference
+effects and adatom-induced magnetism in graphene.",1008.4387v1
+2010-10-23,High spin polarization in epitaxial films of ferrimagnetic Mn3Ga,"Ferrimagnetic Mn3Ga exhibits a unique combination of low saturation
+magnetization (Ms = 0.11 MA m-1) and high perpendicular anisotropy with a
+uniaxial anisotropy constant of Ku = 0.89 MJ m-3. Epitaxial c-axis films
+exhibit spin polarization as high as 58%, measured using point contact Andreev
+reflection. These epitaxial films will be able to support thermally stable
+sub-10 nm bits for spin transfer torque memories.",1010.4872v1
+2010-12-27,Disorder induced superconducting ratchet effect in nanowires,"A dc voltage drop develops along amorphous indium oxide nanowires that are
+exposed to an ac bias source. This voltage is anti-symmetric with magnetic
+field and is characterized by sample specific quasi-periodic magneto-voltage
+oscillations. The voltage magnitude increases with decreasing temperature below
+$T_{C}$ but saturates at low T. As the disorder of the sample is decreased, the
+dc voltage is suppressed. We suggest that this rectification is a manifestation
+of the superconducting ratchet effect in which disorder and geometrical
+confinement play the role of asymmetric pinning centers. This effect
+demonstrates the importance of inherent inhomogeneity and vortex motion in the
+superconductor-insulator transition of disordered superconductors.",1012.5609v1
+2011-03-25,Magnetic Neutron Scattering in Solid Oxygen and its Applications to Ultracold Neutron Production,"Using neutron scattering, we investigate the static and dynamic structure
+functions $S(Q,\omega)$ of 3 distinct solid phases (using powder average
+techniques), and characterize the corresponding modes of energy excitation,
+focusing primarily on the dynamics of spin interaction. With the $S(Q,\omega)$
+maps, we extract the temperature dependent production rate and upscattering
+cross section, that are relevant for understanding experimental data on
+ultracold neutron production in solid oxygen at the saturated vapor pressure.",1103.5091v1
+2011-07-31,Electrolyte gate-controlled Kondo effect in SrTiO3,"We report low-temperature, high-field magnetotransport measurements of SrTiO3
+gated by an ionic gel electrolyte. A saturating resistance upturn and negative
+magnetoresistance that signal the emergence of the Kondo effect appear for
+higher applied gate voltages. This observation, enabled by the wide tunability
+of the ionic gel-applied electric field, promotes the interpretation of the
+electric field-effect induced 2D electron system in SrTiO3 as an admixture of
+magnetic Ti3+ ions, i.e. localized and unpaired electrons, and delocalized
+electrons that partially fill the Ti 3d conduction band.",1108.0139v2
+2011-08-03,Parametric amplification of magnetoplasmons in semiconductor quantum dots,"We show that the magnetoplasmon collective modes in quasi-two-dimensional
+semiconductor quantum dots can be parametrically amplified by periodically
+modulating the magnetic field perpendicular to the nanostructure. The two
+magnetoplasmon modes are excited and amplified simultaneously, leading to an
+exponential growth of the number of bosonic excitations in the system. We
+further demonstrate that damping mechanisms as well as anharmonicities in the
+confinement of the quantum dot lead to a saturation of the parametric
+amplification. This work constitutes a first step towards parametric
+amplification of collective modes in many-body fermionic systems beyond one
+dimension.",1108.0891v3
+2011-10-11,Uncertainty relation for photons,"Uncertainty relation for photons that overcomes the difficulties caused by
+the nonexistence of the photon position operator is derived in quantum
+electrodynamics. The photon energy density plays the role of the probability
+density in configuration space. It is shown that the measure of the spatial
+extension based on the energy distribution in space combined with a measure of
+the spread in the photon momentum leads to an inequality that is a natural
+counterpart of the standard Heisenberg relation. Unexpectedly, the equation
+satisfied by the photon wave function in momentum space which saturates the
+uncertainty relations has the form of the Schr\""odinger equation in coordinate
+space in the presence of electric and magnetic charges.",1110.2415v2
+2011-11-22,z/-z Symmetry of spin-orbit coupling and weak localization in graphene,"We show that the influence of spin-orbit (SO) coupling on the weak
+localization effect for electrons in graphene depends on the lack or presence
+of z/-z symmetry in the system. While for z/-z asymmetric SO coupling,
+disordered graphene should display a weak anti-localization behavior at lowest
+temperature, z/-z symmetric coupling leads to an effective saturation of
+decoherence time which can be partially lifted by an in-plane magnetic field,
+thus, tending to restore the weak localization effect.",1111.5267v1
+2012-05-11,Magnetic penetration depth in the presence of a spin-density wave in multiband superconductors at zero temperature,"We present a theoretical description of the London penetration depth of a
+multi-band superconductor in the case when both superconducting and
+spin-density wave orders coexist. We focus on clean systems and zero
+temperature to emphasize the effect of the two competing orders. Our
+calculation shows that the supefluid density closely follows the evolution of
+the superconducting order parameter as doping is increased, saturating to a BCS
+value in the pure superconducting state. Furthermore, we predict a strong
+anisotropic in-pane penetration depth induced by the spin-density wave order.",1205.2564v1
+2012-07-05,Magnetoresistance from quenching of spin quantum correlation in organic semiconductors,"We present a theory of organic magnetoresistance (OMR) based on the quenching
+of the quantum correlation between the carrier's spin and its local environment
+when the incoherent hopping takes place. We prove that this process contributes
+a spin-dependent prefactor to the attempt-to-escape frequency in the hopping
+rate, with its value modulated by the magnetic field. The resulting OMR
+exhibits a positive Lorentzian saturation component and a negative small-field
+component, which are independent of model parameters. These behaviors, with
+their isotope effects, are in good agreement with experimental results.",1207.1152v2
+2012-07-24,Exact results on the Kondo-lattice magnetic polaron,"In this work we revise the theory of one electron in a ferromagnetically
+saturated local moment system interacting via a Kondo-like exchange
+interaction. The complete eigenstates for the finite lattice are derived. It is
+then shown, that parts of these states lose their norm in the limit of an
+infinite lattice. The correct (scattering) eigenstates are calculated in this
+limit. The time-dependent Schr\""odinger equation is solved for arbitrary
+initial conditions and the connection to the down-electron Green's function and
+the scattering states is worked out. A detailed analysis of the down-electron
+decay dynamics is given.",1207.5623v1
+2012-08-27,Linear magnetoresistance on the topological surface,"A positive, non-saturating and dominantly linear magnetoresistance is
+demonstrated to occur in the surface state of a topological insulator having a
+wavevector-linear energy dispersion together with a finite positive Zeeman
+energy splitting. This linear magnetoresistance shows up within quite wide
+magnetic-field range in a spatially homogenous system of high carrier density
+and low mobility in which the conduction electrons are in extended states and
+spread over many smeared Landau levels, and is robust against increasing
+temperature, in agreement with recent experimental findings in Bi$_2$Se$_3$
+nanoribbons.",1208.5351v1
+2014-03-14,Multiferroic Studies on La0.7Bi0.3CrO3 Perovskite,"Magnetic and dielectric properties on a polycrystalline La0.7Bi0.3CrO3 have
+been investigated. A canted antiferromagnetic (CAF) phase transition giving
+weak ferromagnetism at TN = 230K has been observed. M-H at 10K shows
+non-saturating trend, even up to 5T, confirms the CAF ordering. The
+permittivity ({\epsilon}')-vs-temperature (T) variation shows a relaxor
+ferroelectric (RFE) nature accompanied by a pronounced anomaly in {\epsilon}'-T
+at TN. The anomaly in {\epsilon}'-T at TN indicates the presence of
+magentoelectric (ME) coupling in this material.",1403.3520v1
+2014-03-26,Energy-based modeling of electric motors,"We propose a new approach to model electrical machines based on energy
+considerations and construction symmetries of the motor. We detail the approach
+on the Permanent-Magnet Synchronous Motor and show that it can be extended to
+Synchronous Reluctance Motor and Induction Motor. Thanks to this approach we
+recover the usual models without any tedious computation. We also consider
+effects due to non-sinusoidal windings or saturation and provide experimental
+data.",1403.6641v1
+2014-07-23,Organic magnetoresistance from deep traps,"We predict that singly-occupied carrier traps, produced by electrical stress
+or irradiation within organic semiconductors, can cause spin blockades and the
+large room-temperature magnetoresistance known as organic magnetoresistance.
+The blockade occurs because many singly-occupied traps can only become doubly
+occupied in a spin-singlet configuration. Magnetic-field effects on spin mixing
+during transport dramatically modify the effects of this blockade and produce
+magnetoresistance.We calculate the quantitative effects of these traps on
+organic magnetoresistance from percolation theory and find a dramatic nonlinear
+dependence of the saturated magnetoresistance on trap density, leading to
+values $\sim$ 20%, within the theory's range of validity.",1407.6277v1
+2014-08-19,Magnetoresistive property study of direct and indirect band gap thermoelectric Bi-Sb alloys,"We report magnetoresistive properties of direct and indirect band gap
+Bismuth-Antimony (Bi-Sb) alloys. Band gap increases with magnetic field. Large
+positive magnetoresistance (MR) approaching to 400 % is observed. Low field MR
+experiences quadratic growth and at high field it follows a nearly linear
+behavior without sign of saturation. Carrier mobility extracted from low field
+MR data, depicts remarkable high value. Correlation between MR and mobility is
+revealed. We demonstrate that the strong nearly linear MR at high field can be
+well understood by classical method, co-build by Parish and Littlewood.",1408.4305v1
+2014-09-16,Tuning ferromagnetism at interfaces between insulating perovskite oxides,"We use density functional theory calculations to show that the LaAlO3|SrTiO3
+interface between insulating perovskite oxides is borderline in satisfying the
+Stoner criterion for itinerant ferromagnetism and explore other oxide
+combinations with a view to satisfying it more amply. The larger lattice
+parameter of an LaScO3|BaTiO3 interface is found to be less favorable than the
+greater interface distortion of LaAlO3|CaTiO3. Compared to LaAlO3|SrTiO3, the
+latter is predicted to exhibit robust magnetism with a larger saturation moment
+and a higher Curie temperature. Our results provide support for a ""two phase""
+picture of coexistent superconductivity and ferromagnetism.",1409.4554v1
+2015-09-27,Exchange Bias following Kinetic Arrest,"Exchange bias is often observed when anti-ferromagnetic and ferromagnetic
+phases coexist. The coexistence of two competing magnetic phases can persist to
+the lowest temperatures if the disorder-broadened 1st order transition
+separating them is interrupted, as is proposed in the kinetic arrest
+phenomenon. The fractions of coexisting phases can, in this phenomenon, be
+tuned by following different cooling protocols. We discuss predicted behaviours
+of exchange bias resulting from the kinetic arrest phenomenon. Specifically,
+for appropriate values of cycling field Hmax and measuring temperature T0 there
+will be no exchange bias under cooling in zero field, while it will manifest
+with increasing cooling field, and then saturate.",1509.08052v1
+2016-01-05,Colloidal Microworms Propelling via a Cooperative Hydrodynamic Conveyor Belt,"We study propulsion arising from microscopic colloidal rotors dynamically
+assembled and driven in a viscous fluid upon application of an elliptically
+polarized rotating magnetic field. Close to a confining plate, the motion of
+this self-assembled microscopic worm results from the cooperative flow
+generated by the spinning particles which act as a hydrodynamic ""conveyor
+belt."" Chains of rotors propel faster than individual ones, until reaching a
+saturation speed at distances where induced-flow additivity vanishes. By
+combining experiments and theoretical arguments, we elucidate the mechanism of
+motion and fully characterize the propulsion speed in terms of the field
+parameters.",1601.00806v1
+2016-09-07,Magnetodielectric and spin-lattice coupling in quasi 1D Ising spin chain CoNb$_{2}$O$_{6}$,"We have studied magnetodielectric and spin-lattice coupling in
+CoNb$_{2}$O$_{6}$ single crystals. Magnetostriction and magnetodielectric
+experiments are performed at temperatures in and above antifferomagnetic phase
+of quasi 1D Ising spin chain CoNb$_{2}$O$_{6}$. Field induced magnetic
+transitions are clearly reflected in magnetodielectric measurement as well as
+magnetostriction measurement also. Two sharp anomalies are found around the
+critical fields of antiferromagnetic to ferrimagnetic transition and
+ferrimagnetic to saturated paramagnetic transition in both magnetodielectric
+and magnetostriction experiments. High field anomaly is more pronounced for
+magnetodielectric response and magnetostriction also. So, in CoNb$_{2}$O$_{6}$,
+spins are strongly coupled with lattice as well as charges also.",1609.02048v1
+2016-10-21,Electromotive forces generated in 3d-transition ferromagnetic metal films themselves under their ferromagnetic resonance,"We report the electromotive force (EMF) properties generated in 3d-transition
+ferromagnetic metal (FM = Fe, Co, and Ni80Fe20) films themselves under their
+ferromagnetic resonance (FMR). For Fe and Co films, the EMF due to the
+anomalous-Hall effect is dominantly generated under their FMR. Meanwhile, for a
+Ni80Fe20 film, the EMF due to the inverse spin-Hall effect in the Ni80Fe20 film
+itself under the FMR is mainly generated. This tendency is qualitatively
+explained with differences of the spin polarization, the spin Hall
+conductivity, the anomalous Hall conductivity, the magnetization saturation,
+and the resistivity of the FM films.",1610.06695v2
+2017-09-26,Three-dimensional Bose-Einstein Condensation in the Spin-1/2 Ferromagnetic-leg Ladder 3-Br-4-F-V,"The critical exponent of the phase boundary has been examined on the
+three-dimensional incommensurate ordering phase in the spin-1/2
+ferromagnetic-leg ladder 3-Br-4-F-V
+[=3-(3-bromo-4-fluorophenyl)-1,5-diphenylverdazyl]. Using the
+temperature-window fitting technique, we obtained the critical exponents which
+agreed with the three-dimensional (3D) Bose-Einstein condensation (BEC)
+universality class at both sides of the lower critical field and the saturation
+field. 3-Br-4-F-V thus becomes a new member of the quantum magnets which prove
+the universality of the 3D BEC exponent.",1709.08849v1
+2018-05-09,Crossover of skyrmion and helical modulations in noncentrosymmetric ferromagnets,"The coupling between angular (twisting) and longitudinal modulations arising
+near the ordering temperature of noncentrosymmetric ferromagnets strongly
+influences the structure of skyrmion states and their evolution in an applied
+magnetic field. In the precursor states of cubic helimagnets, a continuous
+transformation of skyrmion lattices into the saturated state is replaced by the
+first-order processes accompanied by the formation of multidomain states.
+Recently the effects imposed by dominant longitudinal modulations have been
+reported in bulk MnSi and FeGe. Similar phenomena can be observed in the
+precursor regions of cubic helimagnet epilayers and in easy-plane chiral
+ferromagnets (e.g. in the hexagonal helimagnet CrNb3S6).",1805.03360v1
+2018-07-17,A Luneburg lens for spin waves,"We report on the theory of a Luneburg lens for forward-volume magnetostatic
+spin waves, and verify its operation via micromagnetic modelling. The lens
+converts a plane wave to a point source (and vice versa) by a designed graded
+index, realised here by either modulating the thickness or the saturation
+magnetization in a circular region. We find that the lens enhances the wave
+amplitude by 5 times at the lens focus, and 47% of the incident energy arrives
+in the focus region. Furthermore, small deviations in the profile can still
+result in good focusing, if the lens index is graded smoothly.",1807.06705v1
+2018-11-14,On the background-gyroresonant character of the Bell instability,"We show that the Bell instability, which is widely considered potentially
+important for cosmic-ray acceleration, is the low-frequency limit of a
+gyroresonant interaction between the protons of the interstellar medium and
+shear-Alfv\'en waves. At large cosmic-ray current densities, its growth rate is
+therefore limited by the proton gyrofrequency, and two modes emerge from the
+cold-beam dispersion relation. A third mode driven by electron gyroresonance is
+only weakly unstable at low current densities. We discuss implications for
+magnetic-field amplification and its saturation in the vicinity of supernova
+remnants.",1811.05666v1
+2019-05-21,Absolute frequency measurement of rubidium 5S-6P transitions,"We report on measurements on the 5S-6P rubidium transition frequencies for
+rubidium isotopes with an absolute uncertainty of better than \SI{450}{kHz} for
+the 5S $\rightarrow$ 6P$_{1/2}$ transition and \SI{20}{kHz} for the 5S
+$\rightarrow$ 6P$_{3/2}$ transition, achieved by saturation absorption
+spectroscopy. From the results we derive the hyperfine splitting with an
+accuracy of \SI{460}{kHz} and \SI{30}{kHz}, respectively. We also verify the
+literature values for the isotope shifts as well as magnetic dipole constant
+and the electric quadrupole constant.",1905.08824v1
+2019-08-30,Late-time large-distance asymptotics of the transverse correlation functions of the XX chain in the space-like regime,"We derive an explicit expression for the leading term in the late-time,
+large-distance asymptotic expansion of a transverse dynamical two-point
+function of the XX chain in the spacelike regime. This expression is valid for
+all non-zero finite temperatures and for all magnetic fields below the
+saturation threshold. It is obtained here by means of a straightforward
+term-by-term analysis of a thermal form factor series, derived in previous
+work, and demonstrates the usefulness of the latter.",1908.11555v1
+2019-11-12,Pairwise entanglement in double-tetrahedral chain with different Landé g-factors of the Ising and Heisenberg spins,"The pairwise entanglement is exactly examined in the spin-1/2
+Ising-Heisenberg double-tetrahedral chain with different Land\'e g-factors of
+the Ising and Heisenberg spins at zero and finite temperatures. It is shown
+that the phenomenon present in quantum non-chiral ground states is twice as
+strong as in quantum chiral ground states and that it gradually diminishes with
+increasing temperature until it completely vanishes at a certain threshold
+temperature. It is also demonstrated that the strong magnetic field maintains a
+weak thermal entanglement quite far from the saturation field, although the
+ground state is non-entangled.",1911.04754v1
+2019-12-02,"Slice collective dynamics, projected emittance deterioration and Free Electron Laser performances detrimental effects","The dynamical effects inducing geometrical and phase space misalignment of
+bunch slice in X-ray operating Free Electron Lasers can be traced back to a
+plethora of phenomena, both in the linac accelerating section or inside the
+beam transport optic magnet. They are responsible for a spoiling of the beam
+projected qualities and induce, if not properly corrected, an increase of the
+saturation length and a decreasing of the output power. We discuss the
+inclusion of these effects in models employing scaling formulae.",1912.00906v1
+2020-03-03,Heat flux sensing by anomalous Nernst effect in Fe-Al thin films on a flexible substrate,"We performed a numerical analysis of the material parameters required for
+realizing a heat flux sensor exploiting the anomalous Nernst effect (ANE). The
+results showed the importance of high thermopower of ANE ($S_{\text{ANE}}$) and
+small saturation magnetization. This motivated us to investigate the effect of
+Al substitution of Fe on ANE and found $S_{\text{ANE}} =$ 3.4 $\mu$V/K in
+Fe$_{81}$Al$_{19}$ because of the dominant intrinsic mechanism. Using this
+material, we made a prototype ANE-based heat flux sensor on a thin flexible
+polyimide sheet and demonstrated accurate sensing with it. This study gives
+important information for enhancing sensor sensitivity.",2003.01459v1
+2020-05-21,Theory of ground states for classical Heisenberg spin systems VI,"We formulate part VI of a rigorous theory of ground states for classical,
+finite, Heisenberg spin systems. After recapitulating the central results of
+the parts I - V previously published we consider a magnetic field and
+analytically calculate the susceptibility at the saturation point. To this end
+we have to distinguish between parabolic and non-parabolic systems, and for the
+latter ones between two- and three-dimensional ground states. These results are
+checked for a couple of examples.",2005.10487v1
+2020-08-26,Quantum criticality in the 2d quasiperiodic Potts model,"Quantum critical points in quasiperiodic magnets can realize new universality
+classes, with critical properties distinct from those of clean or disordered
+systems. Here, we study quantum phase transitions separating ferromagnetic and
+paramagnetic phases in the quasiperiodic $q$-state Potts model in $2+1d$. Using
+a controlled real-space renormalization group approach, we find that the
+critical behavior is largely independent of $q$, and is controlled by an
+infinite-quasiperiodicity fixed point. The correlation length exponent is found
+to be $\nu=1$, saturating a modified version of the Harris-Luck criterion.",2008.11742v1
+2022-03-09,Vector cnoidal and solitary plasmon polariton waves in a planar waveguide,"The paper considers the dynamics of nonlinear surface plasmon polariton waves
+in a planar plasmon waveguide, which is a heterostructure of non-magnetic
+metallic and dielectric layers. The obtained in the work nonlinear equations
+and their analytical solutions describe the vector cnoidal and solitary plasmon
+polariton waves excited by single electromagnetic pulse at the waveguide.
+Nonlinear plasmon polariton waves arise under the influence of the Kerr
+nonlinearity of metal and the saturation of nonlinearity at the
+heterostructure. The period and profile of envelope of the excited nonlinear
+surface plasmon polariton wave vary depending on the conditions of excitation
+and the power of exciting electromagnetic pulse.",2203.05011v1
+2022-05-14,S=2 Quantum Spin Chain with the Biquadratic Exchange Interaction,"The $S=2$ quantum spin chain with the single-ion anisotropy $D$ and the
+biquadratic exchange interaction $J_{\rm BQ}$ is investigated using the
+numerical diagonalization of finite-size clusters and the level spectroscopy
+analysis. It is found that the intermediate-$D$ phase corresponding to the
+symmetry protected topological (SPT) phase appears in a wide region of the
+ground state phase diagram. We also obtain the phase diagram at the half of the
+saturation magnetization which includes the SPT plateau phase.",2205.07005v1
+2022-06-06,Parameter estimation with the steady states of non-Hermitian spin chains,"We propose a scheme for parameter estimation with the steady states of
+non-Hermitian spin chains. The parameters to be estimated are encoded in the
+system via the external magnetic field that imposed on the first site of the
+chain. We obtain the analytical spectrum for the spin chain of two sites. We
+find that the quantum Fisher information (QFI) about the amplitude of the
+imposing field diverges while the QFI about the azimuthal angle reaches to the
+maximum at exceptional points. Moreover, the QFI is enhanced as the system size
+increasing and saturates for sufficiently long spin chain because only
+short-range correlations are induced by the imposing field.",2206.02322v1
+2023-03-10,Weighted CLR type bounds in two dimensions,"We derive weighted versions of the Cwikel-Lieb-Rozenblum inequality for the
+Schr\""odinger operator in two dimensions with a nontrivial Aharonov-Bohm
+magnetic field. Our bounds capture the optimal dependence on the flux and we
+identify a class of long-range potentials that saturate our bounds in the
+strong coupling limit. We also extend our analysis to the two-dimensional
+Schr\""odinger operator acting on antisymmetric functions and obtain similar
+results.",2303.06104v1
+2023-07-28,Analysis of magneto-optical Kerr spectra of ferrimagnetic Mn$_4$N,"Simulations of magneto-optical Kerr effect in biaxially strained Mn$_4$N are
+performed using density functional theory and linear response theory. We
+consider three ferrimagnetic phases, two collinear and one noncollinear, which
+have been corroborated separately by earlier studies. The simulated spectra are
+compared to magneto-optical data available in recent literature. A collinear
+ferrimagnetic phase with a small saturation magentization, a large
+perpendicular anisotropy, and Curie temperature above 700~K is found to be
+consistent with the measured spectra. We hypothesise that an admixture of the
+noncollinear phase, which could explain the lower than predicted net moment and
+magnetic anisotropy observed experimentally, is also present.",2307.15246v1
+2023-12-28,Cosmic-Ray-modified and driven instabilities,"These lectures address the effects of Cosmic Rays over macro-instabilities
+which develop in the interstellar medium and the micro-instabilities the
+particles are able to trigger themselves. The lectures are centered on the
+derivation of linear growth rates but also discuss some numerical simulations
+addressing the issue of magnetic field saturation. A particular emphasis is
+made on the streaming instability, an instability driven by anisotropic
+cosmic-ray distributions.",2312.17134v1
+2024-03-18,"A new method to search for highly ionizing exotic particles, monopoles and beyond, using time projection chamber","Measuring the energy loss and mass of highly ionizing particles predicted by
+theories from beyond the Standard Model pose considerable challenges to
+conventional detection techniques. Such particles are predicted to experience
+energy loss to matter they pass through that exceeds the dynamic range
+specified for most readout chips, leading to saturation of the detectors'
+electronics. Consequently, achieving precise energy loss and mass measurements
+becomes unattainable. We present a new approach to detect such highly ionizing
+particles using time projection chambers that overcomes this limitation and
+provide a case study for triggering on magnetic monopoles.",2403.12299v1
+1997-04-14,Hydrogen Phases on the Surface of a Strongly Magnetized Neutron Star,"The outermost layers of some neutron stars are likely to be dominated by
+hydrogen, as a result of fast gravitational settling of heavier elements. These
+layers directly mediate thermal radiation from the stars, and determine the
+characteristics of X-ray/EUV spectra. For a neutron star with surface
+temperature $T\lo 10^6$ K and magnetic field $B\go 10^{12}$ G, various forms of
+hydrogen can be present in the envelope, including atom, poly-molecules, and
+condensed metal. We study the physical properties of different hydrogen phases
+on the surface of a strongly magnetized neutron star for a wide range of field
+strength $B$ and surface temperature $T$. Depending on the values of $B$ and
+$T$, the outer envelope can be either in a nondegenerate gaseous phase or in a
+degenerate metallic phase. For $T\go 10^5$ K and moderately strong magnetic
+field, $B\lo 10^{13}$ G, the envelope is nondegenerate and the surface material
+gradually transforms into a degenerate Coulomb plasma as density increases. For
+higher field strength, $B>> 10^{13}$ G, there exists a first-order phase
+transition from the nondegenerate gaseous phase to the condensed metallic
+phase. The column density of saturated vapor above the metallic hydrogen
+decreases rapidly as the magnetic field increases or/and temperature decreases.
+Thus the thermal radiation can directly emerge from the degenerate metallic
+hydrogen surface. The characteristics of surface X-ray/EUV emission for
+different phases are discussed. A separate study concerning the possibility of
+magnetic field induced nuclear fusion of hydrogen on the neutron star surface
+is also presented.",9704130v1
+1999-12-02,Magnetic history dependence of metastable states in systems with dipolar interactions,"We present the results of a Monte Carlo simulation of the ground state and
+magnetic relaxation of a model of a thin film consisting on a two-dimensional
+square lattice of Heisenberg spins with perpendicular anisotropy K, exchange J
+and long-range dipolar interactions g. We have studied the ground state
+configurations of this system for a wide range of the interaction parameters
+J/g, K/g by means of the simulated annealing procedure, showing that the model
+is able to reproduce the different magnetic configurations found in real
+samples. We have found the existence of a certain range of K/g, J/g values for
+which in-plane and out-of-plane configurations are quasi-degenerated in energy.
+We show that when a system in this region of parameters is perturbed by an
+external force that is subsequently removed different kinds of ordering may be
+induced depending on the followed procedure. In particular, simulations of
+relaxations from saturation under an a.c. demagnetizing field or in zero field
+are in qualitative agreement with recent experiments on epitaxial and granular
+alloy thin films, which show a wide variety of magnetic patterns depending on
+their magnetic history.",9912025v2
+2004-12-14,Current-induced magnetization changes in a spin valve due to incoherent emission of non-equilibrium magnons,"We describe spin transfer in a ferromagnet/normal metal/ferromagnet
+spin-valve point contact. Spin is transferred from the spin-polarized device
+current to the magnetization of the free layer by the mechanism of incoherent
+magnon emission by electrons. Our approach is based on the rate equation for
+the magnon occupation, using Fermi's golden rule for magnon emission and
+absorption and the non-equilibrium electron distribution for a biased spin
+valve. The magnon emission reduces the magnetization of the free layer. For
+anti-parallel alignment of the magnetizations of the layers and at a critical
+bias a magnon avalanche occurs, characterized by a diverging effective magnon
+temperature. This critical behavior can result in magnetization reversal and
+consequently to suppression of magnon emission. However, magnon-magnon
+scattering can lead to saturation of the magnon concentration at a large but
+finite value. The further behavior depends on the parameters of the system. In
+particular, gradual evolution of the magnon concentration followed by a
+magnetization reversal is possible. Another scenario corresponds to a step-like
+increase of the magnon concentration followed by a slow decrease. In the latter
+case a spike in the differential resistance is expected due to a contribution
+of electron-magnon scattering. A comparison of the obtained results to existing
+experimental data and theoretical approches is given.",0412348v1
+2005-03-27,Magnetic Vortex Resonance in Patterned Ferromagnetic Dots,"We report a high-resolution experimental detection of the resonant behavior
+of magnetic vortices confined in small disk-shaped ferromagnetic dots. The
+samples are magnetically soft Fe-Ni disks of diameter 1.1 and 2.2 um, and
+thickness 20 and 40 nm patterned via electron beam lithography onto microwave
+co-planar waveguides. The vortex excitation spectra were probed by a vector
+network analyzer operating in reflection mode, which records the derivative of
+the real and the imaginary impedance as a function of frequency. The spectra
+show well-defined resonance peaks in magnetic fields smaller than the
+characteristic vortex annihilation field. Resonances at 162 and 272 MHz were
+detected for 2.2 and 1.1 um disks with thickness 40 nm, respectively. A
+resonance peak at 83 MHz was detected for 20-nm thick, 2-um diameter disks. The
+resonance frequencies exhibit weak field dependence, and scale as a function of
+the dot geometrical aspect ratio. The measured frequencies are well described
+by micromagnetic and analytical calculations that rely only on known properties
+of the dots (such as the dot diameter, thickness, saturation magnetization, and
+exchange stiffness constant) without any adjustable parameters. We find that
+the observed resonance originates from the translational motion of the magnetic
+vortex core.",0503632v1
+2005-06-22,Spin configurations in circular and rectangular vertical quantum dots in a magnetic field: Three-dimensional self-consistent simulation,"The magnetic field dependence of the electronic properties of \textit{real}
+single vertical quantum dots in circular and rectangular mesas is investigated
+within a full three-dimensional multiscale self-consistent approach without any
+{\it \'a priori} assumptions about the shape and strength of the confinement
+potential. The calculated zero field electron addition energies are in good
+agreement with available experimental data for both mesa geometries. Charging
+diagrams in a magnetic field for number of electrons up to five are also
+computed. Consistent with the experimental data, we found that the charging
+curves for the rectangular mesa dot in a magnetic field are flatter and exhibit
+less features than for a circular mesa dot. Evolution of the singlet-triplet
+energy separation in the two electron system for both dot geometries in
+magnetic field was also investigated. In the limit of large field, beyond the
+singlet-triplet transition, the singlet-triplet energy difference continues to
+become more negative in a circular mesa dot without any saturation within the
+range of considered magnetic fields whilst it is predicted to asymptotically
+approach zero for the rectangular mesa dot. This different behavior is
+attributed to the symmetry ""breaking"" that occurs in the singlet wave-functions
+in the rectangular mesa dot but not in the circular one.",0506585v1
+2006-09-21,Universal emergence of the one-third plateau in the magnetization process of frustrated quantum spin chains,"We present a numerical study of the magnetization process of frustrated
+quantum spin-S chains with S=1, 3/2, 2 as well as the classical limit. Using
+the exact diagonalization and density-matrix renormalization techniques, we
+provide evidence that a plateau at one third of the saturation magnetization
+exists in the magnetization curve of frustrated spin-S chains with S>1/2.
+Similar to the case of S=1/2, this plateau state breaks the translational
+symmetry of the Hamiltonian and realizes an up-up-down pattern in the spin
+component parallel to the external field. Our study further shows that this
+plateau exists both in the cases of an isotropic exchange and in the easy-axis
+regime for spin-S=1, 3/2, and 2, but is absent in classical frustrated spin
+chains with isotropic interactions. We discuss the magnetic phase diagram of
+frustrated spin-1 and spin-3/2 chains as well as other emergent features of the
+magnetization process such as kink singularities, jumps, and even-odd effects.
+A quantitative comparison of the one-third plateau in the easy-axis regime
+between spin-1 and spin-3/2 chains on the one hand and the classical frustrated
+chain on the other hand indicates that the critical frustration and the phase
+boundaries of this state rapidly approach the classical result as the spin S
+increases.",0609555v1
+2007-03-22,Orbital contribution to the magnetic properties of iron as a function of dimensionality,"The orbital contribution to the magnetic properties of Fe in systems of
+decreasing dimensionality (bulk, surfaces, wire and free clusters) is
+investigated using a tight-binding hamiltonian in an $s, p,$ and $d$ atomic
+orbital basis set including spin-orbit coupling and intra-atomic electronic
+interactions in the full Hartree-Fock (HF) scheme, i.e., involving all the
+matrix elements of the Coulomb interaction with their exact orbital dependence.
+Spin and orbital magnetic moments and the magnetocrystalline anisotropy energy
+(MAE) are calculated for several orientations of the magnetization. The results
+are systematically compared with those of simplified hamiltonians which give
+results close to those obtained from the local spin density approximation. The
+full HF decoupling leads to much larger orbital moments and MAE which can reach
+values as large as 1$\mu_B$ and several tens of meV, respectively, in the
+monatomic wire at the equilibrium distance. The reliability of the results
+obtained by adding the so-called Orbital Polarization Ansatz (OPA) to the
+simplified hamiltonians is also discussed. It is found that when the spin
+magnetization is saturated the OPA results for the orbital moment are in
+qualitative agreement with those of the full HF model. However there are large
+discrepancies for the MAE, especially in clusters. Thus the full HF scheme must
+be used to investigate the orbital magnetism and MAE of low dimensional
+systems.",0703576v1
+2003-07-22,Interaction of Electromagnetic Radiation with Supercritical Magnetic Field,"It is pointed, that effects of refraction of electromagnetic radiation in the
+medium, formed by the magnetized vacuum, become essential already for
+relatively soft photons, not hard enough to create an electron-positron pair,
+including those belonging to soft gamma-, X-ray, optic and radio- range, if the
+magnetic field B exceeds the critical value of Bcr=m^2/e=4.4 10^13 Gauss. Three
+leading terms in the asymptotic expansion of the one-loop polarization operator
+in a constant magnetic field are found for B>>Bcr, and the corresponding
+refraction index is shown to depend only on the propagation direction of the
+photon relative to the external field. It is established, that the refraction
+index for one of polarization modes unlimitedly grows with the field, while the
+other is saturated at a moderate level. The photon capture effect is extended
+to soft photons. The results may be essential in studying reflection,
+refraction and splitting of X-rays, light and radio waves by magnetic fields of
+magnetars, as well as in considering emission of such waves by charged
+particles .",0307214v2
+2007-08-27,Strain-driven elastic and orbital-ordering effects on thickness-dependent properties of manganite thin films,"We report on the structural and magnetic characterization of (110) and (001)
+La2/3Ca1/3MnO3 (LCMO) epitaxial thin films simultaneously grown on (110) and
+(001)SrTiO3 substrates, with thicknesses t varying between 8 nm and 150 nm. It
+is found that while the in-plane interplanar distances of the (001) films are
+strongly clamped to those of the substrate and the films remain strained up to
+well above t=100 nm, the (110) films relax much earlier. Accurate determination
+of the in-plane and out-of-plane interplanar distances has allowed concluding
+that in all cases the unit cell volume of the manganite reduces gradually when
+increasing thickness, approaching the bulk value. It is observed that the
+magnetic properties (Curie temperature and saturation magnetization) of the
+(110) films are significantly improved compared to those of (001) films. These
+observations, combined with 55Mn-nuclear magnetic resonance data and X-ray
+photoemission spectroscopy, signal that the depression of the magnetic
+properties of the more strained (001)LCMO films is not caused by an elastic
+deformation of the perovskite lattice but rather due to the electronic and
+chemical phase separation caused by the substrate-induced strain. On the
+contrary, the thickness dependence of the magnetic properties of the less
+strained (110)LCMO films are simply described by the elastic deformation of the
+manganite lattice. We will argue that the different behavior of (001) and
+(110)LCMO films is a consequence of the dissimilar electronic structure of
+these interfaces.",0708.3602v1
+2008-05-15,Thickness dependent magnetic anisotropy of ultrathin LCMO epitaxial thin films,"The magnetic properties of La0.7Ca0.3MnO3 (LCMO) manganite thin films were
+studied with magnetometry and ferromagnetic resonance as a function of film
+thickness. They maintain the colossal magnetoresistance behavior with a
+pronounced metal-insulator transition around 150-200 K, except for the very
+thinnest films studied (3 nm). Nevertheless, LCMO films as thin as 3 nm remain
+ferromagnetic, without a decrease in saturation magnetization, indicating an
+absence of dead-layers, although below approx. 6 nm the films remain insulating
+at low temperature. Magnetization hysteresis loops reveal that the magnetic
+easy axes lie in the plane of the film for thicknesses in the range of 4-15 nm.
+Ferromagnetic resonance studies confirm that the easy axes are in-plane, and
+find a biaxial symmetry in-plane with two, perpendicular easy axes. The
+directions of the easy axes with respect to the crystallographic directions of
+the cubic SrTiO3 substrate differ by 45 degrees in 4 nm and 15 nm thick LCMO
+films.",0805.2336v1
+2008-07-05,Vector chiral and multipolar orders in the spin-1/2 frustrated ferromagnetic chain in magnetic field,"We study the one-dimensional spin-1/2 Heisenberg chain with competing
+ferromagnetic nearest-neighbor J_1 and antiferromagnetic next-nearest-neighbor
+J_2 exchange couplings in the presence of magnetic field. We use both numerical
+approaches (the density matrix renormalization group method and exact
+diagonalization) and effective field-theory approach, and obtain the
+ground-state phase diagram for wide parameter range of the coupling ratio
+J_1/J_2. The phase diagram is rich and has a variety of phases, including the
+vector chiral phase, the nematic phase, and other multipolar phases. In the
+vector chiral phase, which appears in relatively weak magnetic field, the
+ground state exhibits long-range order (LRO) of vector chirality which
+spontaneously breaks a parity symmetry. The nematic phase shows a quasi-LRO of
+antiferro-nematic spin correlation, and arises as a result of formation of
+two-magnon bound states in high magnetic fields. Similarly, the higher
+multipolar phases, such as triatic (p=3) and quartic (p=4) phases, are formed
+through binding of p magnons near the saturation fields, showing quasi-LRO of
+antiferro-multipolar spin correlations. The multipolar phases cross over to
+spin density wave phases as the magnetic field is decreased, before
+encountering a phase transition to the vector chiral phase at a lower field.
+The implications of our results to quasi-one-dimensional frustrated magnets
+(e.g., LiCuVO_4) are discussed.",0807.0858v2
+2008-11-26,Dirac equation description on the electronic states and magnetic properties of a square graphene quantum dot,"Electronic eigen-states of a square graphene quantum dot(GQD) terminated by
+both zigzag and armchair edges are derived in the theoretical framework of
+Dirac equation. We find that the Dirac equation can determine the eigen-energy
+spectrum of a GQD with high accuracy even if its size is reduced to a few
+nanometers. More importantly, from the Dirac equation description we can
+readily work out the number and energy gap of the conjugate surface states,
+which are intimately associated with the magnetic properties of the GQD. By
+using the Hartree-Fock mean field approach, we study the size dependence of the
+magnetic ordering formation in this square GQD. We find that there exists a
+critical size of the width between the two zigzag edges to indicate the onset
+of the stable magnetic ordering. On the other hand, when such a width increases
+further, the magnetic ground state energy of a charge neutral GQD tends to a
+saturated value. These results coincide with the previous results obtained from
+the first principle calculation. Then, based on the Dirac equation solution
+about the surface state, we establish a simple two-state model which can
+quantitatively explain the size dependence of the magnetic ordering in the
+square GQD.",0811.4312v1
+2009-06-29,A novel wear-resistant magnetic thin film material based on a $Ti_{1-x}Fe_xC_{1-y}$ nanocomposite alloy,"In this study we report on the film growth and characterization of thin
+(approximately 50 nm thick) Ti-Fe-C films deposited on amorphous quartz. The
+experimental studies have been complemented by first principles density
+functional theory (DFT) calculations. Upon annealing of as-prepared films, the
+composition of the metastable Ti-Fe-C film changes. An iron-rich phase is first
+formed close to the film surface, but with increasing annealing time this phase
+is gradually displaced toward the film-substrate interface where its position
+stabilizes. Both the magnetic ordering temperature and the saturation
+magnetization changes significantly upon annealing. The DFT calculations show
+that the critical temperature and the magnetic moment both increase with
+increasing Fe and C-vacancy concentration. The formation of the metastable
+iron-rich Ti-Fe-C compound is reflected in the strong increase of the magnetic
+ordering temperature. Eventually, after enough annealing time ($\geq 10$
+minutes), nano-crystalline $\alpha$-Fe starts to precipitate and the amount and
+size of these precipitates can be controlled by the annealing procedure; after
+20 minutes of annealing, the experimental results indicate a nano-crystalline
+iron-film embedded in a wear resistant TiC compound. This conclusion is further
+supported by transmission electron microscopy studies on epitaxial Ti-Fe-C
+films deposited on single crystalline MgO substrates where, upon annealing, an
+iron film embedded in TiC is formed. Our results suggest that annealing of
+metastable Ti-Fe-C films can be used as an efficient way of creating a
+wear-resistant magnetic thin film material.",0906.5386v1
+2009-11-18,Kelvin-Helmholtz Instability of the Magnetopause of Disc-Accreting Stars,"This work investigates the short wavelength stability of the magnetopause
+between a rapidly-rotating, supersonic, dense accretion disc and a
+slowly-rotating low-density magnetosphere of a magnetized star. The
+magnetopause is a strong shear layer with rapid changes in the azimuthal
+velocity, the density, and the magnetic field over a short radial distance and
+thus the Kelvin-Helmholtz (KH) instability may be important. The plasma
+dynamics is treated using non-relativistic, compressible (isentropic)
+magnetohydrodynamics. It is necessary to include the displacement current in
+order that plasma wave velocities remain less than the speed of light. We focus
+mainly on the case of a star with an aligned dipole magnetic field so that the
+magnetic field is axial in the disc midplane and perpendicular to the disc flow
+velocity. However, we also give results for cases where the magnetic field is
+at an arbitrary angle to the flow velocity. For the aligned dipole case the
+magnetopause is most unstable for KH waves propagating in the azimuthal
+direction perpendicular to the magnetic field which tends to stabilize waves
+propagating parallel to it. The wave phase velocity is that of the disc matter.
+A quasi-linear theory of the saturation of the instability leads to a
+wavenumber ($k$) power spectrum $\propto k^{-1}$ of the density and temperature
+fluctuations of the magnetopause, and it gives the mass accretion and angular
+momentum inflow rates across the magnetopause. For self-consistent conditions
+this mass accretion rate will be equal to the disc accretion rate at large
+distances from the magnetopause.",0911.3590v1
+2009-12-26,Magnetic Amplification by Magnetized Cosmic Rays in SNR Shocks,"(Abridged) X-ray observations of synchrotron rims in supernova remnant (SNR)
+shocks show evidence of strong magnetic field amplification (a factor of ~100
+between the upstream and downstream medium). This amplification may be due to
+plasma instabilities driven by shock-accelerated cosmic rays (CRs). One
+candidate is the cosmic ray current-driven (CRCD) instability (Bell 2004),
+caused by the electric current of large Larmor radii CRs propagating parallel
+to the upstream magnetic field. Particle-in-cell (PIC) simulations have shown
+that the back-reaction of the amplified field on CRs would limit the
+amplification factor of this instability to less than ~10 in galactic SNRs. In
+this paper, we study the possibility of further amplification driven near
+shocks by ""magnetized"" CRs, whose Larmor radii are smaller than the length
+scale of the field that was previously amplified by the CRCD instability. We
+find that additional amplification can occur due to a new instability, driven
+by the CR current perpendicular to the field, which we term the ""perpendicular
+current-driven instability"" (PCDI). We derive the growth rate of this
+instability, and, using PIC simulations, study its non-linear evolution and
+saturation. We find that PCDI increases the amplification of the field
+(amplification factor up to ~45, not including the shock compression) and
+discuss its observational signatures. Our results strengthen the idea of CRs
+driving a significant part of the magnetic field amplification observed in SNR
+shocks.",0912.4990v1
+2010-11-04,"Magnetic order, metamagnetic transitions, and low-temperature spin freezing in Ca3Co2O6: an NMR study","We report on a 59Co NMR investigation of the trigonal cobaltate Ca3Co2O6
+carried out on a single crystal, providing precise determinations of the
+electric field gradient and chemical shift tensors, and of the internal
+magnetic fields at the non-magnetic Co I sites, unavailable from former studies
+on powders. The magnetic field-induced ferri- and ferromagnetic phases at
+intermediate temperature (e.g. 10 K) are identified by distinct internal
+fields, well accounted for by purely dipolar interactions. The vanishing
+transferred hyperfine field at the Co I site indicates that the Co3+(I)
+orbitals do not participate in the intra-chain superexchange, in disagreement
+with a previous theoretical model. The strong Ising character of the system is
+confirmed experimentally by the field dependence of the resonance lines,
+indicating that local moments are saturated even at the phase boundaries. In
+the vicinity of the critical fields, nuclear spin-spin relaxations detect the
+spin reversal dynamics of large magnetic assemblies, either Ising chain
+fragments or finite size domains, which drive the metamagnetic transitions.
+Such collective excitations exhibit a glassy behavior, slowing down to
+subacoustic frequencies and freezing at low temperature. The relevance of such
+slow fluctuation modes for the low-temperature multi-step behavior reported in
+the magnetization is discussed.",1011.1142v2
+2011-02-17,Magnetic fields during primordial star formation,"Recent FERMI observations provide a lower limit of 10^{-15} G for the
+magnetic field strength in the intergalactic medium (IGM). This is consistent
+with theoretical expectations based on the Biermann battery effect, which
+predicts such IGM fields already at redshifts z~10. During gravitational
+collapse, such magnetic fields can be amplified by compression and by
+turbulence, giving rise to the small-scale dynamo. On scales below the Jeans
+length, the eddy turnover timescale is much shorter than the free-fall
+timescale, so that saturation can be reached during collapse. This scenario has
+been tested and confirmed with magneto-hydrodynamical simulations following the
+collapse of a turbulent, weakly magnetized cloud. Based on a spectral analysis,
+we confirm that turbulence is injected on the Jeans scale. For the power
+spectrum of the magnetic field, we obtain the Kazantsev slope which is
+characteristic for the small-scale dynamo. A calculation of the critical length
+scales for ambipolar diffusion and Ohmic dissipation shows that these scales
+are always small enough to allow significant amplification of the magnetic
+field by small-scale eddies. We discuss potential implications for the
+protostellar accretion disk, with particular focus on the magneto-rotational
+instability, which may change the morphology of the disk and reduce the
+accretion rate by a factor of a few.",1102.3558v1
+2011-03-15,Magnetohydrodynamic Simulations of Reconnection and Particle Acceleration: Three-Dimensional Effects,"The magnetic fields can change their topology through a process known as
+magnetic reconnection. This process in not only important for understanding the
+origin and evolution of the large-scale magnetic field, but is seen as a
+possibly efficient particle accelerator producing cosmic rays mainly through
+the first order Fermi process. In this work we study the properties of particle
+acceleration in reconnection zones and show that the velocity component
+parallel to the magnetic field of test particles inserted in nearly
+non-resistive magnetohydrodynamic (MHD) domains of reconnection without
+including kinetic effects, such as pressure anisotropy, the Hall term, or
+anomalous effects, increases exponentially. Also, the acceleration of the
+perpendicular component is always possible in such models. We have found that
+within contracting magnetic islands or current sheets the particles accelerate
+predominantly through the first order Fermi process, as previously described,
+while outside the current sheets and islands the particles experience mostly
+drift acceleration due to magnetic fields gradients. Considering two
+dimensional MHD models without a guide field, we find that the parallel
+acceleration stops at some level. This saturation effect is however removed in
+the presence of an out-of-plane guide field or in three dimensional models.
+Therefore, we stress the importance of the guide field and fully three
+dimensional studies for a complete understanding of the process of particle
+acceleration in astrophysical reconnection environments.",1103.2984v1
+2011-07-05,Spindown of Isolated Neutron Stars: Gravitational Waves or Magnetic Braking?,"We study the spindown of isolated neutron stars from initially rapid rotation
+rates, driven by two factors: (i) gravitational wave emission due to r-modes
+and (ii) magnetic braking. In the context of isolated neutron stars, we present
+the first study including self-consistently the magnetic damping of r-modes in
+the spin evolution. We track the spin evolution employing the RNS code, which
+accounts for the rotating structure of neutron stars for various equations of
+state. We find that, despite the strong damping due to the magnetic field,
+r-modes alter the braking rate from pure magnetic braking for B<10^{13}G. For
+realistic values of the saturation amplitude, the r-mode can also decrease the
+time to reach the threshold central density for quark deconfinement. Within a
+phenomenological model, we assess the gravitational waveform that would result
+from r-mode driven spindown of a magnetized neutron star. To contrast with the
+persistent signal during the spindown phase, we also present a preliminary
+estimate of the transient gravitational wave signal from an explosive
+quark-hadron phase transition, which can be a signal for the deconfinement of
+quarks inside neutron stars.",1107.1000v2
+2011-07-16,Magnetic effects in heavy-ion collisions at intermediate energies,"The time-evolution and space-distribution of internal electromagnetic fields
+in heavy-ion reactions at beam energies between 200 and 2000 MeV/nucleon are
+studied within an Isospin-dependent Boltzmann-Uhling-Uhlenbeck transport model
+IBUU11. While the magnetic field can reach about $7\times 10^{16}$ G which is
+significantly higher than the estimated surface magnetic field ($\sim 10^{15}$
+G) of magnetars, it has almost no effect on nucleon observables as the Lorentz
+force is normally much weaker than the nuclear force. Very interestingly,
+however, the magnetic field generated by the projectile-like (target-like)
+spectator has a strong focusing/diverging effect on positive/negative pions at
+forward (backward) rapidities. Consequently, the differential $\pi^-/\pi^+$
+ratio as a function of rapidity is significantly altered by the magnetic field
+while the total multiplicities of both positive and negative pions remain about
+the same. At beam energies above about 1 GeV/nucleon, while the integrated
+ratio of total $\pi^-$ to $\pi^+$ multiplicities is not, the differential
+$\pi^-/\pi^+$ ratio is sensitive to the density dependence of nuclear symmetry
+energy $E_{\rm{sym}}(\rho)$. Our findings suggest that magnetic effects should
+be carefully considered in future studies of using the differential
+$\pi^-/\pi^+$ ratio as a probe of the $E_{\rm{sym}}(\rho)$ at supra-saturation
+densities.",1107.3192v1
+2012-03-20,Ferromagnetism induced in anisotropic stacked kagome-lattice antiferromagnet Cs$_2$Cu$_3$CeF$_{12}$,"The magnetic properties of Cs$_2$Cu$_3$CeF$_{12}$ were investigated through
+magnetization and specific heat measurements. Cs$_2$Cu$_3$CeF$_{12}$ is
+composed of a buckled kagome lattice of Cu$^{2+}$, which is stacked along the b
+axis. The exchange network in the buckled kagome lattice is strongly
+anisotropic. Consequently, Cs$_2$Cu$_3$CeF$_{12}$ can be divided into two
+subsystems: alternating Heisenberg chains with strong antiferromagnetic
+exchange interactions and dangling spins. The dangling spins couple with one
+another via effective exchange interactions, which are mediated by chain spins.
+The dangling spins are further divided into two subsystems, DS1 and DS2. The
+dangling spins in DS1 undergo three-dimensional ferromagnetic ordering at 3.14
+K, while those in DS2 remain paramagnetic down to 0.35 K. The effective
+interaction between the DS1 spins is approximately expressed by the
+ferromagnetic $XXZ$ model with the $z$ direction parallel to the
+crystallographic c axis. A magnetic phase diagram for $H {\parallel} c$ was
+obtained and was analyzed within the framework of the molecular field
+approximation. With increasing magnetic field, the dangling spins are polarized
+and the magnetization curve exhibits a wide plateau at one-third of the
+saturation magnetization.",1203.4453v1
+2012-03-21,Magneto-thermal properties of the Heisenberg-Ising orthogonal-dimer chain with triangular XXZ-clusters,"We study a spin-1/2 model with triangular XXZ-clusters on the
+orthogonal-dimer chain in the presence of an external magnetic field. First, we
+discuss the case where the triangular clusters are coupled via intermediate
+""classical"" Ising spins. Diagonalization of the triangular XXZ-clusters yields
+the exact ground states; finite-temperature properties are computed exactly by
+an additional transfer-matrix step. A detailed analysis reveals a large variety
+of ground states at magnetization M equal to fractions 0, 1/4, and 1/2 of the
+saturation magnetization M=1. Some of these ground states break translational
+symmetry spontaneously and give rise to doubling of the unit cell. In a second
+part we present complementary numerical data for the spin-1/2 Heisenberg model
+on the orthogonal-dimer chain. We analyze several examples of T=0 magnetization
+curves, entropy as a function of temperature T and magnetic field, and the
+associated magnetic cooling rate. Comparison of the two models shows that in
+certain situations the simplified exactly solvable model yields a qualitatively
+or sometimes even quantitatively accurate description of the more challenging
+quantum model, including a case which may be relevant to experimental
+observations of an enhanced magnetocaloric effect in the two-dimensional
+compound SrCu2(BO3)2.",1203.4741v2
+2013-05-06,Study of Ni and Zn doped CeOFeAs: Effect on the structural transition and specific heat capacity,"We have systematically studied the substitution of nonmagnetic Zn and
+magnetic Ni at iron sites in Ce based oxypnictide. The parent compound
+(CeOFeAs) shows an anomaly in resistivity around 150 K due to structural
+transition from tetragonal (space group: P4/nmm) to orthorhombic structure
+(space group: Cmma). Substitution of Zn suppresses this anomaly to lower
+temperature (~130 K) but Ni substitution does not show any anomaly around this
+temperature and the compound behaves like a metal. Further, we find that non
+magnetic (Zn) doping leads to higher impurity scattering as compared to
+magnetic Ni doping. Similar to the resistivity measurement, the specific heat
+shows another jump near 4 K for CeOFeAs. This is attributed to the ordering of
+Ce3+ moments. This peak shifts to 3.8 K for Zn substituted compound and there
+is no change in the ordering temperature in the Ni substituted CeOFeAs. These
+peaks are broadened in applied magnetic field (5 T) and the calculated magnetic
+entropy tends to saturate at the same value for 0 T and 5 T external magnetic
+field.",1305.1088v2
+2013-05-29,Thermodynamic Properties of the Anisotropic Frustrated Spin-chain Compound Linarite PbCuSO$_4$(OH)$_2$,"We present a comprehensive macroscopic thermodynamic study of the
+quasi-one-dimensional (1D) $s = \tfrac{1}{2}$ frustrated spin-chain system
+linarite. Susceptibility, magnetization, specific heat, magnetocaloric effect,
+magnetostriction, and thermal-expansion measurements were performed to
+characterize the magnetic phase diagram. In particular, for magnetic fields
+along the b axis five different magnetic regions have been detected, some of
+them exhibiting short-range-order effects. The experimental magnetic entropy
+and magnetization are compared to a theoretical modelling of these quantities
+using DMRG and TMRG approaches. Within the framework of a purely 1D isotropic
+model Hamiltonian, only a qualitative agreement between theory and the
+experimental data can be achieved. Instead, it is demonstrated that a
+significant symmetric anisotropic exchange of about 10% is necessary to account
+for the basic experimental observations, including the 3D saturation field, and
+which in turn might stabilize a triatic (three-magnon) multipolar phase.",1305.6731v3
+2013-07-23,Study of the flux effect on nuclear pressure vessel steel by measurement of magnetic properties,"Since Reactor Pressure Vessel steels are ferromagnetic, they provide a
+convenient means to monitor changes in the mechanical properties of the
+material upon irradiation with high energy particles, by measuring their
+magnetic properties. Here, we discuss the correlation between these two
+properties (i.e. mechanical and magnetic properties) and microstructure, by
+studying the flux effect on the nuclear pressure vessel steel used in reactors
+currently under construction in Argentina. Charpy-V notched specimens of this
+steel were irradiated in the RA1 experimental reactor at 275{\deg}C with two
+lead factors (LFs), 93 and 183. The magnetic properties were studied by means
+of DC magnetometry and ferromagnetic resonance. The results show that the
+coercive field and magnetic anisotropy spatial distribution are sensitive to
+the LF and can be explained by taking into account the evolution of the
+microstructure with this parameter. The saturation magnetization shows a
+dominant dependence on the accumulated damage. Consequently, the mentioned
+techniques are suitable to estimate the degradation of the reactor vessel
+steel.",1307.6124v2
+2013-09-18,"Magnetization process, bipartite entanglement and enhanced magnetocaloric effect of the exactly solved spin-1/2 Ising-Heisenberg tetrahedral chain","The frustrated spin-1/2 Ising-Heisenberg ladder with Heisenberg intra-rung
+and Ising inter-rung interactions is exactly solved in a longitudinal magnetic
+field by taking advantage of the local conservation of the total spin on each
+rung and the transfer-matrix method. We have rigorously calculated the
+ground-state phase diagram, magnetization process, magnetocaloric effect and
+basic thermodynamic quantities for the model, which can be alternatively viewed
+as an Ising-Heisenberg tetrahedral chain. It is demonstrated that a stepwise
+magnetization curve with an intermediate plateau at a half of the saturation
+magnetization is also reflected in respective stepwise changes of the
+concurrence serving as a measure of bipartite entanglement. The ground-state
+phase diagram and zero-temperature magnetization curves of the Ising-Heisenberg
+tetrahedral chain are contrasted with the analogous results of the purely
+quantum Heisenberg tetrahedral chain, which have been obtained through
+density-matrix renormalization group (DMRG) calculations. While both
+ground-state phase diagrams fully coincide in the regime of weak inter-rung
+interaction, the purely quantum Heisenberg tetrahedral chain develops Luttinger
+spin-liquid and Haldane phases for strongly coupled rungs which are absent in
+the Ising-Heisenberg counterpart model.",1309.4603v2
+2014-03-18,Two-Fluid Description of Wave-Particle Interactions in Strong Buneman Turbulence,"To understand the nature of anomalous resistivity in magnetic reconnection,
+we investigate turbulence-induced momentum transport and energy dissipation
+while a plasma is unstable to the Buneman instability in force-free current
+sheets. Using 3D particle-in-cell simulations, we find that the macroscopic
+effects generated by wave-particle interactions in Buneman instability can be
+approximately described by a set of electron fluid equations. We show that both
+energy dissipation and momentum transport along electric current in the current
+layer are locally quasi-static, but globally dynamic and irreversible.
+Turbulent drag dissipates both the streaming energy of the current sheet and
+the associated magnetic energy. The net loss of streaming energy is converted
+into the electron component heat conduction parallel to the magnetic field and
+increases the electron Boltzmann entropy. The growth of self-sustained Buneman
+waves satisfies a Bernoulli-like equation that relates the turbulence-induced
+convective momentum transport and thermal momentum transport. Electron trapping
+and de-trapping drive local momentum transports, while phase mixing converts
+convective momentum into thermal momentum. The drag acts like a micro-macro
+link in the anomalous heating processes. The decrease of magnetic field
+maintains an inductive electric field that re-accelerates electrons, but most
+of the magnetic energy is dissipated and converted into the component heat of
+electrons perpendicular to the magnetic field. This heating process is
+decoupled from the heating of Buneman instability in the current sheets. Ion
+heating is weak but ions plays an important role in assisting energy exchanges
+between waves and electrons. Cold ion fluid equations together with our
+electron fluid equations form a complete set of equations that describes the
+occurrence, growth, saturation and decay of the Buneman instability.",1403.4552v2
+2014-09-30,Producing Magnetar Magnetic Fields in the Merger of Binary Neutron Stars,"The merger of binary neutron stars (BNSs) can lead to large amplifications of
+the magnetic field due to the development of turbulence and instabilities in
+the fluid, such as the Kelvin-Helmholtz shear instability, which drive
+small-scale dynamo activity. In order to properly resolve such instabilities
+and obtain the correct magnetic field amplification, one would need to employ
+resolutions that are currently unfeasible in global general relativistic
+magnetohydrodynamic (GRMHD) simulations of BNS mergers. Here, we present a
+subgrid model that allows global simulations to take into account the
+small-scale amplification of the magnetic field which is caused by the
+development of turbulence during BNS mergers. Assuming dynamo saturation, we
+show that magnetar-level fields ($\sim 10^{16}\,{\rm G}$) can be easily
+reached, and should therefore be expected from the merger of magnetized BNSs.
+The total magnetic energy can reach values up to $\sim 10^{51}\,{\rm erg}$ and
+the post-merger remnant can therefore emit strong electromagnetic signals and
+possibly produce short gamma-ray bursts.",1410.0013v2
+2014-11-18,The Turbulent Dynamo in Highly Compressible Supersonic Plasmas,"The turbulent dynamo may explain the origin of cosmic magnetism. While the
+exponential amplification of magnetic fields has been studied for
+incompressible gases, little is known about dynamo action in
+highly-compressible, supersonic plasmas, such as the interstellar medium of
+galaxies and the early Universe. Here we perform the first quantitative
+comparison of theoretical models of the dynamo growth rate and saturation level
+with three-dimensional magnetohydrodynamical simulations of supersonic
+turbulence with grid resolutions of up to 1024^3 cells. We obtain numerical
+convergence and find that dynamo action occurs for both low and high magnetic
+Prandtl numbers Pm = nu/eta = 0.1-10 (the ratio of viscous to magnetic
+dissipation), which had so far only been seen for Pm >= 1 in supersonic
+turbulence. We measure the critical magnetic Reynolds number, Rm_crit = 129
+(+43, -31), showing that the compressible dynamo is almost as efficient as in
+incompressible gas. Considering the physical conditions of the present and
+early Universe, we conclude that magnetic fields need to be taken into account
+during structure formation from the early to the present cosmic ages, because
+they suppress gas fragmentation and drive powerful jets and outflows, both
+greatly affecting the initial mass function of stars.",1411.4707v2
+2014-12-04,Cross-correlation Aided Transport in Stochastically Driven Accretion Flows,"Origin of linear instability resulting in rotating sheared accretion flows
+has remained a controversial subject for long. While some explanations of such
+non-normal transient growth of disturbances in the Rayleigh stable limit were
+available for magnetized accretion flows, similar instabilities in absence of
+magnetic perturbations remained unexplained. This dichotomy was resolved in two
+recent publications by Chattopadhyay, {\it et al} where it was shown that such
+instabilities, especially for non-magnetized accretion flows, were introduced
+through interaction of the inherent stochastic noise in the system (even a
+\enquote{cold} accretion flow at 3000K is too \enquote{hot} in the statistical
+parlance and is capable of inducing strong thermal modes) with the underlying
+Taylor-Couette flow profiles. Both studies, however, excluded the additional
+energy influx (or efflux) that could result from nonzero cross-correlation of a
+noise perturbing the velocity flow, say, with the noise that is driving the
+vorticity flow (or equivalently the magnetic field and magnetic vorticity flow
+dynamics). In this article we show that nonzero noise cross-correlations
+essentially renormalize the strength of temporal correlations. Apart from an
+overall boost in the energy rate (both for spatial and temporal correlations,
+and hence in the ensemble averaged energy spectra), this results in mutual
+competition in growth rates of affected variables often resulting in
+suppression of oscillating Alfven waves at small times while leading to faster
+saturations at relatively longer time scales. The effects are seen to be more
+pronounced with magnetic field fluxes where the noise cross-correlation
+magnifies the strength of the field concerned.",1412.1752v1
+2015-01-30,Stability of magnetized strange quark matter in the MIT bag model with the density dependent bag pressure,"The stability of magnetized strange quark matter (MSQM) is studied in the MIT
+bag model with the density dependent bag pressure. In the consistent
+thermodynamic description of MSQM, the quark chemical potentials, the total
+thermodynamic potential and the anisotropic pressure acquire the corresponding
+additional term proportional to the density derivative of the bag pressure. The
+model parameter space is determined, for which MSQM is absolutely stable, i.e.,
+its energy per baryon is less than that of the most stable $^{56}$Fe nucleus
+under the zero external pressure and vanishing temperature. It is shown that
+there exists the magnetic field strength $H_{u\,max}$ at which the upper bound
+$B_\infty^u$ on the asymptotic bag pressure $B_\infty\equiv B(\varrho_B\gg
+\varrho_0$) ($\varrho_0$ being the nuclear saturation density) from the
+absolute stability window vanishes. The value of this field,
+\hbox{$H_{u\,max}\sim$$(1$--$3)\cdot10^{18}$}~G, represents the upper bound on
+the magnetic field strength, which can be reached in a strongly magnetized
+strange quark star. It is clarified how the absolute stability window and upper
+bound on the magnetic field strength are affected by varying the parameters in
+the Gaussian parametrization for the density dependence of the bag pressure.",1501.07772v1
+2015-04-09,Site occupancy and magnetic properties of Al-substituted M-type strontium hexaferrite,"We use first-principles total-energy calculations based on density functional
+theory to study the site occupancy and magnetic properties of Al-substituted
+$M$-type strontium hexaferrite SrFe$_{12-x}$Al$_{x}$O$_{19}$ with $x=0.5$ and
+$x=1.0$. We find that the non-magnetic Al$^{3+}$ ions preferentially replace
+Fe$^{3+}$ ions at two of the majority spin sites, $2a$ and $12k$, eliminating
+their positive contribution to the total magnetization causing the saturation
+magnetization $M_s$ to be reduced as Al concentration $x$ is increased. Our
+formation probability analysis further provides the explanation for increased
+magnetic anisotropy field when the fraction of Al is increased. Although
+Al$^{3+}$ ions preferentially occupy the $2a$ sites at a low temperature, the
+occupation probability of the $12k$ site increases with the rise of the
+temperature. At a typical annealing temperature ($> 700\,^{\circ}{\rm C}$)
+Al$^{3+}$ ions are much more likely to occupy the $12k$ site than the $2a$
+site. Although this causes the magnetocrystalline anisotropy $K_1$ to be
+reduced slightly, the reduction in $M_s$ is much more significant. Their
+combined effect causes the anisotropy field $H_a$ to increase as the fraction
+of Al is increased, consistent with recent experimental measurements.",1504.02320v2
+2015-10-06,Spin Hall magnetoresistance as a probe for surface magnetization in Pt/CoFe$_2$O$_4$ bilayers,"We study the spin Hall magnetoresistance (SMR) in Pt grown $\textit{in situ}$
+on CoFe$_2$O$_4$ (CFO) ferrimagnetic insulating (FMI) films. A careful analysis
+of the angle-dependent and field-dependent longitudinal magnetoresistance
+indicates that the SMR contains a contribution that does not follow the bulk
+magnetization of CFO but it is a fingerprint of the complex magnetism at the
+surface of the CFO layer, thus signaling SMR as a tool for mapping surface
+magnetization. A systematic study of the SMR for different temperatures and CFO
+thicknesses gives us information impossible to obtain with any standard
+magnetometry technique. On one hand, surface magnetization behaves
+independently of the CFO thickness and does not saturate up to high fields,
+evidencing that the surface has its own anisotropy. On the other hand,
+characteristic zero-field magnetization steps are not present at the surface
+while they are relevant in the bulk, strongly suggesting that antiphase
+boundaries are the responsible of such intriguing features. In addition, a
+contribution from ordinary magnetoresistance of Pt is identified, which is only
+distinguishable due to the low resistivity of the $\textit{in-situ}$ grown Pt.",1510.01449v2
+2016-02-18,Spin Liquid State in the 3D Frustrated Antiferromagnet PbCuTe2O6: NMR and muSR Studies,"PbCuTe2O6 is a rare example of a spin liquid candidate featuring a three
+dimensional magnetic lattice. Strong geometric frustration arises from the
+dominant antiferromagnetic interaction which generates a hyperkagome network of
+Cu2+ ions although additional interactions enhance the magnetic lattice
+connectivity. Through a combination of magnetization measurements and local
+probe investigation by NMR and muSR down to 20 mK, we provide a robust evidence
+for the absence of magnetic freezing in the ground state. The local spin
+susceptibility probed by the NMR shift hardly deviates from the macroscopic one
+down to 1 K pointing to a homogeneous magnetic system with a low defect
+concentration. The saturation of the NMR shift and the sublinear power law
+temperature (T) evolution of the 1/T1 NMR relaxation rate at low T point to a
+non-singlet ground state favoring a gapless fermionic description of the
+magnetic excitations. Below 1 K a pronounced slowing down of the spin dynamics
+is witnessed, which may signal a reconstruction of spinon Fermi surface.
+Nonetheless, the compound remains in a fluctuating spin liquid state down to
+the lowest temperature of the present investigation.",1602.05818v1
+2016-04-06,Universal behavior of dense clusters of magnetic nanoparticles,"A detailed numerical simulation of quasistatic hysteresis loops of dense
+clusters of interacting magnetic nanoparticles is carried out. Both clusters of
+magnetically soft and magnetically hard nanoparticles are considered. The
+clusters are characterized by an average particle diameter D, the cluster
+radius Rc, the particle saturation magnetization Ms, and the uniaxial
+anisotropy constant K. The number of particles in the cluster varies between Np
+= 30 - 120. The particle centers are randomly distributed within the cluster,
+their easy anisotropy axes being randomly oriented. It is shown that a rare
+assembly of identical random clusters of magnetic nanoparticles can be
+characterized by two dimensionless parameters: 1) the relative strength of
+magneto-dipole interaction, K/Ms^2, and the average particle concentration
+within the cluster, {\eta} = VNp/Vc. Here V is the nanoparticle volume, and Vc
+is the volume of the cluster, respectively. In the strong interaction limit,
+Ms*{\eta}/Ha >> 1, where Ha = 2K/Ms is the anisotropy field, the ultimate
+hysteresis loops of dilute assemblies of clusters have been constructed. In the
+variables (M/Ms, H/Ms) these hysteresis loops depend only on the particle
+volume fraction {\eta}. In the weak interaction limit, Ms*{\eta}/Ha << 1, the
+assembly hysteresis loops in the variables (M/Ms, H/Ha) are close to the
+standard Stoner-Wohlfarth hysteresis loop.",1604.01705v1
+2016-06-30,Surface magnetism of strontium titanate,"SrTiO3 plays a central role in oxide electronics. It is the substrate of
+choice for functional oxide heterostructures based on perovskite-structure
+thin-film stacks, and its surface or interface with a polar oxide such as
+LaAlO3 can become a two-dimensional conductor because of electronic
+reconstruction or the presence of oxygen defects. Inconsistent reports of
+magnetic order in SrTiO3 abound in the literature. Here we report a systematic
+experimental study aimed at establishing how and when SrTiO3 can develop a
+magnetic moment at room temperature. Polished 100, 110 or 111 crystal slices
+from four different suppliers are characterized before and after vacuum
+annealing at 750 {\deg}C, both in single-crystal and powdered form. Impurity
+content is analysed at the surface and in the bulk. Besides the underlying
+intrinsic diamagnetism of SrTiO3, magnetic signals are of three types-a Curie
+law susceptibility due to dilute magnetic impurities at the ppm level, a
+hysteretic, temperature-dependent ferromagnetic impurity contribution, and a
+practically-anhysteretic, defect-related temperature-independent component that
+saturates in about 200 mT. The latter component is intrinsic. It is often the
+largest, reaching 10 Bohr magnetons per nm2 of surface area or more and
+dominating the magnetic response in low fields at room temperature. It is
+associated with defects near the surface, and can be destroyed by treatment
+with Tiron (C6H4Na2O8S2), an electron donor molecule that forms a strong
+complex with titanium at the surface. The origin of this unusual
+high-temperature ferromagnetic-like response is discussed.",1606.09422v1
+2016-07-04,First-principles investigations into the thermodynamics of cation disorder and it's impact on electronic structure and magnetic properties of spinel $Co\left(Cr_{1-x}Mn_{x} \right)_{2}O_{4}$,"Recent experiments on Mn doped multiferroic $CoCr_{2}O_{4}$ indicate that a
+possible distribution of Mn atoms among tetrahedrally and octahedrally
+coordinated sites in the spinel lattice give rise to different variations in
+the structural parameters and saturation magnetisations in different
+concentration regimes of Mn atoms substituting the Cr. A composition dependent
+magnetic compensation behaviour points to the role conversions of the magnetic
+constituents. In this work, we have investigated the thermodynamics of cation
+disorder in $Co\left(Cr_{1-x}Mn_{x}\right)_{2}O_{4}$ system and it's
+consequences on the structural, electronic and magnetic properties, using
+results from first-principles electronic structure calculations. We have
+computed the variations in the cation-disorder as a function of Mn
+concentration and the temperature and found that at the annealing temperature
+of the experiment many of the systems exhibit cation disorder. Our results
+support the interpretations of the experimental results regarding the
+qualitative variations in the sub-lattice occupancies and the associated
+magnetisation behaviour, with composition. We have analysed the variations in
+structural, magnetic and electronic properties of this system with variations
+in the compositions and the degree of cation disorder from the variations in
+their electronic structures and by using the ideas from crystal field theory.
+Our study provides a complete microscopic picture of the effects that are
+responsible for composition dependent behavioural differences of the properties
+of this system. This work lays down a general framework, based upon results
+from first-principles calculations, to understand and analyse the
+substitutional magnetic spinel oxides $A\left(B_{1-x}C_{x} \right)_{2}O_{4}$ in
+presence of cation disorder.",1607.00742v1
+2016-10-19,Surface tension of highly magnetized degenerate quark matter,"We study the surface tension of highly magnetized three flavor quark matter
+within the formalism of multiple reflection expansion (MRE). Quark matter is
+described as a mixture of free Fermi gases composed by quarks $u$, $d$, $s$ and
+electrons, in chemical equilibrium under weak interactions. Due to the presence
+of strong magnetic fields the particles' transverse motion is quantized into
+Landau levels, and the surface tension has a different value in the parallel
+and transverse directions with respect to the magnetic field.
+  We calculate the transverse and longitudinal surface tension for different
+values of the magnetic field and for quark matter drops with different sizes,
+from a few fm to the bulk limit. For baryon number densities between $2-10$
+times the nuclear saturation density, the surface tension falls in the range $2
+- 20$ MeV /fm$^{2}$. The largest contribution comes from strange quarks which
+have a surface tension an order of magnitude larger than the one for $u$ or $d$
+quarks and more than two orders of magnitude larger than for electrons. Our
+results show that the total surface tension is quite insensitive to the size of
+the drop. We also find that the surface tensions in the transverse and parallel
+directions are almost unaffected by the magnetic field if $eB$ is below $\sim 5
+\times 10^{-3} $ GeV$^2$. Nevertheless, for higher values of $eB$, there is a
+significant increase in the parallel surface tension and a significant decrease
+in the transverse one with respect to the unmagnetized case.",1610.05875v2
+2016-11-10,Pressure-induced quantum phase transition in the itinerant ferromagnet UCoGa,"In this paper, we report the results of a high pressure study of the
+itinerant 5f-electron ferromagnet UCoGa. The work is focused on probing the
+expected ferromagnet-to-paramagnet quantum phase transition induced by high
+pressure and on the general features of the P-T(-H) phase diagram. Diamond
+anvil cells were employed to measure the magnetization and electrical
+resistivity under pressures up to ~ 10 GPa.At ambient pressure, UCoGa exhibits
+collinear ferromagnetic ordering of uranium magnetic moments {\mu}U ~ 0.74
+{\mu}B (at 2 K) aligned along the c-axis of the hexagonal crystal structure
+below Curie temperature TC = 48K. With the application of pressure, gradual
+decrease of both, TC and the saturated magnetic moment, has been observed up to
+pressures ~ 6 GPa. This is followed by a sharp drop of magnetic moment and a
+sudden disappearance of the magnetic order at the pressure of 6.5 GPa,
+suggesting a first-order phase transition, as expected for a clean system. The
+low temperature power law dependence of the electrical resistivity shows
+distinct anomalies around the ~ 6 GPa, consistent with the pressure evolution
+of the magnetic moment and the ordering temperature. The tricritical point of
+the UCoGa phase diagram is located at approximately ~ 30 K and ~ 6 GPa.",1611.03276v1
+2017-04-08,Prompt photon yield and elliptic flow from gluon fusion induced by magnetic fields in relativistic heavy-ion collisions,"We compute photon production at early times in semi-central relativistic
+heavy-ion collisions from non-equilibrium gluon fusion induced by a magnetic
+field. The calculation accounts for the main features of the collision at these
+early times, namely, the intense magnetic field and the high gluon occupation
+number. The gluon fusion channel is made possible by the magnetic field and
+would otherwise be forbidden due to charge conjugation invariance. Thus, the
+photon yield from this process is an excess over calculations without magnetic
+field effects. We compare this excess to the difference between PHENIX data and
+recent hydrodynamic calculations for the photon transverse momentum
+distribution and elliptic flow coefficient $v_2$. We show that with reasonable
+values for the saturation scale and magnetic field strength, the calculation
+helps to better describe the experimental results obtained at RHIC energies for
+the lowest part of the transverse photon momentum.",1704.02433v4
+2017-05-02,Global MHD Simulations of Accretion Disks in Cataclysmic Variables (CVs): II The Relative Importance of MRI and Spiral Shocks,"We perform global three-dimensional MHD simulations of unstratified accretion
+disks in cataclysmic variables (CVs). By including mass inflow via an accretion
+stream, we are able to evolve the disk to a steady state. We investigate the
+relative importance of spiral shocks and the magnetorotational instability
+(MRI) in driving angular momentum transport and how each depend on the geometry
+and strength of seed magnetic field and the Mach number of the disk (where Mach
+number is ratio of the azimuthal velocity and the sound speed of gas). We use a
+locally isothermal equation of state and adopt temperature profiles that are
+consistent with CV disk observations. Our results indicate that the relative
+importance of spiral shocks and MRI in driving angular momentum transport is
+controlled by the gas Mach number and the seed magnetic field strength. MRI and
+spiral shocks provide comparable efficiency of angular momentum transport when
+the disk Mach number is around 10 and the seed magnetic field has plasma
+$\beta=400$ (where $\beta$ is ratio of gas pressure and magnetic pressure). The
+MRI dominates whenever the seed field strength, or the disk Mach number, is
+increased. Among all of our simulations, the effective viscosity parameter
+$\alpha_{eff} \sim 0.016-0.1$ after MRI saturates and the disk reaches steady
+state. Larger values of $\alpha_{eff}$ are favored when the seed magnetic field
+has vertical components or the flow has stronger magnetization ($1/\beta$). Our
+models all indicate that the role of MRI in driving angular momentum transport
+thus mass accretion in CV disks is indispensable, especially in cool disks with
+weak spiral shocks.",1705.00779v1
+2018-03-21,Sub-photospheric fluctuations in magnetized radiative envelopes: contribution from unstable magnetosonic waves,"We examine the excitation of unstable magnetosonic waves in the radiative
+envelopes of intermediate- and high-mass stars with a magnetic field of ~kG
+strength. Wind clumping close to the star and microturbulence can often be
+accounted for when including small-scale, sub-photospheric density or velocity
+perturbations. Compressional waves - with wavelengths comparable to or shorter
+than the gas pressure scale height - can be destabilized by the radiative flux
+in optically-thick media when a magnetic field is present, in a process called
+the Radiation-Driven Magneto-Acoustic Instability (RMI). The instability does
+not require radiation or magnetic pressure to dominate over gas pressure, and
+acts independently of sub-surface convection zones. Here we evaluate the
+conditions for the RMI to operate on a grid of stellar models covering a mass
+range $3-40M_\odot$ at solar metallicity. For a uniform 1kG magnetic field,
+fast magnetosonic modes are unstable down to an optical depth of a few tens,
+while unstable slow modes extend beyond the depth of the iron convection zone.
+The qualitative behavior is robust to magnetic field strength variations by a
+factor of a few. When combining our findings with previous results for the
+saturation amplitude of the RMI, we predict velocity fluctuations in the range
+~0.1-10 km/s. These amplitudes are a monotonically increasing function of the
+ratio of radiation to gas pressure, or alternatively, of the zero-age main
+sequence mass.",1803.08053v1
+2018-04-06,Effect of Substrate Temperature on Structural and Magnetic Properties of c-axis Ori-ented Spinel Ferrite Ni0.65Zn0.35Fe2O4 (NZFO) Thin Films,"Varying the substrate temperature changes structural and magnetic properties
+of spinel ferrite NZFO thin films. XRD of films grown at different temperature
+display only 004 reflections, without any secondary peaks, showing growth
+orientation along the c axis. We find an increase in crystalline quality of
+these thin films with the rise of substrate temperature. The surface topography
+of the thin films grown on various growth temperatures conditions reveal that
+these films are smooth with low roughness, however the thin films grown at 800
+C exhibit lowest average and rms roughness among all thin films. We find iron
+and nickel to be more oxidized i,e greater Fe and Ni content in films grown and
+annealed at 700 C and 800 C, compared to those grown at lower temperatures. The
+magnetic moment is observed to increase with an increase of substrate
+temperature and all thin films possess high saturation magnetization and low
+coercive field at room temperature. Films grown at 800 C exhibit a
+ferrimagnetic paramagnetic phase transition well above room temperature. The
+observed large magnetizations with soft magnetic behavior in NZFO thin films
+above room temperature suggest potential application in memory, spintronics,
+and multifunctional devices.",1804.02458v2
+2018-05-13,Pressure-induced spin reorientation transition in layered ferromagnetic insulator Cr2Ge2Te6,"Anisotropic magnetoresistance (AMR) of Cr2Ge2Te6 (CGT), a layered
+ferromagnetic insulator, is investigated under an applied hydrostatic pressure
+up to 2 GPa. The easy axis direction of the magnetization is inferred from the
+AMR saturation feature in the presence and absence of the applied pressure. At
+zero applied pressure, the easy axis is along the c-direction or perpendicular
+to the layer. Upon application of a hydrostatic pressure>1 GPa, the uniaxial
+anisotropy switches to easy-plane anisotropy which drives the equilibrium
+magnetization from the c-axis to the ab-plane at zero magnetic field, which
+amounts to a giant magnetic anisotropy energy change (>100%). As the
+temperature is increased across the Curie temperature, the characteristic AMR
+effect gradually decreases and disappears. Our first-principles calculations
+confirm the giant magnetic anisotropy energy change with moderate pressure and
+assign its origin to the increased off-site spin-orbit interaction of Te atoms
+due to a shorter Cr-Te distance. Such a pressure-induced spin reorientation
+transition is very rare in three-dimensional ferromagnets, but it may be common
+to other layered ferromagnets with similar crystal structures to CGT, and
+therefore offers a unique way to control magnetic anisotropy.",1805.04937v1
+2018-06-14,The specific heat and magnetic properties of a spin-1/2 ladder including butterfly-shaped unit blocks,"The specific heat, structural characterization, and magnetic property studies
+of a new spin ladder with the geometry of butterfly-shaped configuration are
+reported. The model introduced here is an infinite spin ladder-type including
+spin-1/2 particle for which unit blocks consist of two butterflies connected
+together through their bodies (Body-Body bridges). Localized spins on the wings
+of butterflies have XXZ Heisenberg interaction with two extra spin-1/2
+particles assumed in the center of each cage (unit block), while they have pure
+Ising-type interaction with those spins that are localized on the bodies.
+Hence, there are six interstitial spins and four nodal spins (Body-Body
+interaction) per block. To obtain the partition function of this model, we use
+the transfer matrix approach, then we examine the magnetization process, as
+well as, the specific heat of the model. Interestingly, we see a wide plateau
+at $\frac{5}{6}$ of the saturation magnetization that is strongly dependent on
+the magnetic field and anisotropy variations. Moreover, some unexpected
+phenomena are observed in the low-temperature limit, such as anomalous
+triple-peak in the specific heat function which gradually turns to a
+double-peak upon increasing the magnetic field and/or anisotropic Heisenberg
+coupling, due to the ferromagnetic phase predomination.",1806.05391v2
+2018-07-20,Ising versus Potts criticality in a low-temperature magnetothermodynamics of a frustrated spin-1/2 Heisenberg triangular bilayer,"Low-temperature magnetization curves and thermodynamics of a frustrated
+spin-1/2 Heisenberg triangular bilayer with the antiferromagnetic intradimer
+interaction and either ferromagnetic or antiferromagnetic interdimer
+interaction are investigated in a highly frustrated parameter region, where
+localized many-magnon eigenstates provide the most dominant contribution to
+magnetothermodynamics. Low-energy states of the highly frustrated spin-1/2
+Heisenberg triangular bilayer can be accordingly found from a mapping
+correspondence with an effective triangular-lattice spin-1/2 Ising model in a
+field. A description based on the effective Ising model implies that the
+frustrated Heisenberg triangular bilayer with the ferromagnetic interdimer
+coupling displays in a zero-temperature magnetization curve discontinuous
+magnetization jump, which is reduced upon increasing of temperature until a
+continuous field-driven phase transition from the Ising universality class is
+reached at a certain critical temperature. The frustrated Heisenberg triangular
+bilayer with the antiferromagnetic interdimer coupling contrarily exhibits
+multistep magnetization curve with intermediate plateaus at one-third and
+two-thirds of the saturation magnetization, whereas discontinuous magnetization
+jumps observable at zero temperature change to continuous field-driven phase
+transitions from the universality class of three-state Potts model at
+sufficiently low temperatures. Exact results and Monte Carlo simulations of the
+effective Ising model are confronted with full exact diagonalization data for
+the Heisenberg triangular bilayer in order to corroborate these findings.",1807.08042v2
+2018-08-10,Diamond magnetic microscopy of malarial hemozoin nanocrystals,"Magnetic microscopy of malarial hemozoin nanocrystals was performed using
+optically detected magnetic resonance imaging of near-surface diamond
+nitrogen-vacancy centers. Hemozoin crystals were extracted from
+$Plasmodium$-$falciparum$-infected human blood cells and studied alongside
+synthetic hemozoin crystals. The stray magnetic fields produced by individual
+crystals were imaged at room temperature as a function of applied field up to
+350 mT. More than 100 nanocrystals were analyzed, revealing the distribution of
+their magnetic properties. Most crystals ($96\%$) exhibit a linear dependence
+of stray field magnitude on applied field, confirming hemozoin's paramagnetic
+nature. A volume magnetic susceptibility $\chi=3.4\times10^{-4}$ is inferred
+using a magnetostatic model informed by correlated scanning electron microscopy
+measurements of crystal dimensions. A small fraction of nanoparticles (4/82 for
+$Plasmodium$-produced and 1/41 for synthetic) exhibit a saturation behavior
+consistent with superparamagnetism. Translation of this platform to the study
+of living malaria-infected cells may shed new light on hemozoin formation
+dynamics and their interaction with antimalarial drugs.",1808.03636v2
+2018-10-31,Transverse Magneto-Optical Kerr Effect at Narrow Optical Resonances,"Magneto-optical spectroscopy based on the transverse magneto-optical Kerr
+effect (TMOKE) is a sensitive method for investigation of magnetically-ordered
+media. However, in magnetic materials the optical transitions are usually
+characterized by spectrally broad resonances with widths considerably exceeding
+the Zeeman splitting in the magnetic field. Here we investigate experimentally
+and theoretically the TMOKE in the vicinity of relatively narrow optical
+resonances provided by confined quantum systems. For experimental demonstration
+we use the exciton resonance in a (Cd,Mn)Te diluted magnetic semiconductor
+quantum well, where the strong exchange interaction with magnetic ions enables
+the giant Zeeman splitting of exciton spin states $\Delta$ in magnetic fields
+of a few Tesla. In the weak coupling regime, when the splitting $\Delta$ is
+smaller than the spectral broadening of the optical transitions $\Gamma$, the
+TMOKE magnitude grows linearly with the increase of the Zeeman splitting and
+its spectrum has an S-shape, which remains virtually unchanged in this range.
+In the strong coupling regime ($\Delta>\Gamma$) the TMOKE magnitude saturates,
+while its spectrum is strongly modified resulting in the appearance of two
+separate peaks. The TMOKE is sensitive not only to the sample surface but can
+be used to probe the confined electronic states in depth if the upper layer is
+sufficiently transparent. Our results demonstrate that TMOKE of spectrally
+narrow resonances serves as a versatile tool for probing the charge and spin
+structure of electronic states in various confined quantum systems and can be
+used for spin tomography in combination with the conventional polar Kerr
+effect.",1810.13344v1
+2018-12-28,High-order two-fluid plasma solver for direct numerical simulations of plasma flows with full transport phenomena,"The two-fluid plasma equations for a single ion species, with full transport
+terms, including temperature and magnetic field dependent ion and electron
+viscous stresses and heat fluxes, frictional drag force, and ohmic heating term
+have been implemented in the CFDNS code and solved by using sixth-order
+non-dissipative compact finite differences for plasma flows in several
+different regimes. In order to be able to fully resolve all the dynamically
+relevant time and length scales, while maintaining computational feasibility,
+the assumptions of infinite speed of light and negligible electron inertia have
+been made. Non-dimensional analysis of the two-fluid plasma equations shows
+that, by varying the characteristic/background number density, length scale,
+temperature, and magnetic strength, the corresponding Hall, resistive, and
+ideal magnetohydrodynamics (MHD) equations can be recovered as limiting cases.
+The accuracy and robustness of this two-fluid plasma solver in handling plasma
+flows in different regimes have been validated against four canonical problems:
+Alfven and whistler dispersion relations, electromagnetic plasma shock, and
+magnetic reconnection. For all test cases, by using physical dissipation and
+diffusion, with negligible numerical dissipation/diffusion, fully converged
+Direct Numerical Simulations (DNS)-like solutions are obtained when the ion
+Reynolds number based on grid size is smaller than a threshold value which is
+about 2.3 in this study. For the magnetic reconnection problem, the results
+show that the magnetic flux saturation time and value converge when the ion and
+magnetic Reynolds numbers are large enough. Thus, the DNS-like results become
+relevant to practical problems with much larger Reynolds numbers.",1812.11237v1
+2019-03-27,Structural and magnetic properties of GdCo$_{5-x}$Ni$_x$,"GdCo$_5$ may be considered as two sublattices - one of Gd and one of Co -
+whose magnetizations are in antiparallel alignment, forming a ferrimagnet.
+Substitution of nickel in the cobalt sublattice of GdCo$_5$ has been
+investigated to gain insight into how the magnetic properties of this prototype
+rare-earth/transition-metal magnet are affected by changes in the transition
+metal sublattice. Polycrystalline samples of GdCo$_{5-x}$Ni$_x$ for 0 $ \leq x
+\leq $ 5 were synthesized by arc melting. Structural characterization was
+carried out by powder x-ray diffraction and optical and scanning electron
+microscope imaging of metallographic slides, the latter revealing a low
+concentration of Gd$_2$(Co, Ni)$_7$ lamellae for $x \leq 2.5$. Compensation -
+i.e. the cancellation of the opposing Gd and transition metal moments is
+observed for $1 \leq x \leq 3$ at a temperature which increases with Ni
+content; for larger $x$, no compensation is observed below 360 K. A peak in the
+coercivity is seen at $x \approx 1$ at 10K coinciding with a minimum in the
+saturation magnetization. Density-functional theory calculations within the
+disordered local moment picture reproduce the dependence of the magnetization
+on Ni content and temperature. The calculations also show a peak in the
+magnetocrystalline anisotropy at similar Ni concentrations to the
+experimentally observed coercivity maximum.",1903.11442v1
+2020-08-13,Half-metallic ferromagnetism in layered CdOHCl induced by hole doping,"Next-generation spintronic devices will benefit from low-dimensionality,
+ferromagnetism, and half-metallicity, possibly controlled by electric fields.
+We find these technologically-appealing features to be combined with an exotic
+microscopic origin of magnetism in doped CdOHCl, a van der Waals material from
+which 2D layers may be exfoliated. By means of first principles simulations, we
+predict homogeneous hole-doping to give rise to $p$-band magnetism in both the
+bulk and monolayer phases and interpret our findings in terms of Stoner
+instability: as the Fermi level is tuned via hole-doping through singularities
+in the 2D-like density of states, ferromagnetism develops with large saturation
+magnetization of 1 $\mu_B$ per hole, leading to a half-metallic behaviour for
+layer carrier densities of the order of 10$^{14}$ cm$^{-2}$. Furthermore, we
+put forward electrostatic doping as an additional handle to induce magnetism in
+monolayers and bilayers of CdOHCl. Upon application of critical electric fields
+perpendicular to atomically-thin-films (as low as 0.2 V/$A{\deg}$ and 0.5
+V/$A{\deg}$ in the bilayer and monolayer case, respectively), we envisage the
+emergence of a magnetic half-metallic state. The different behaviour of
+monolayer vs bilayer systems, as well as an observed asymmetric response to
+positive and negative electric fields in bilayers, are interpreted in terms of
+intrinsic polarity of CdOHCl atomic stacks, a distinctive feature of the
+material. In perspective, given the experimentally accessible magnitude of
+critical fields in bilayer of CdOHCl, one can envisage $p$ band magnetism to be
+exploited in miniaturized spintronic devices.",2008.05766v1
+2020-09-28,Nanoscale transient magnetization gratings excited and probed by femtosecond extreme ultraviolet pulses,"We utilize coherent femtosecond extreme ultraviolet (EUV) pulses derived from
+a free electron laser (FEL) to generate transient periodic magnetization
+patterns with periods as short as 44 nm. Combining spatially periodic
+excitation with resonant probing at the dichroic M-edge of cobalt allows us to
+create and probe transient gratings of electronic and magnetic excitations in a
+CoGd alloy. In a demagnetized sample, we observe an electronic excitation with
+50 fs rise time close to the FEL pulse duration and ~0.5 ps decay time within
+the range for the electron-phonon relaxation in metals. When the experiment is
+performed on a sample magnetized to saturation in an external field, we observe
+a magnetization grating, which appears on a sub-picosecond time scale as the
+sample is demagnetized at the maxima of the EUV intensity and then decays on
+the time scale of tens of picoseconds via thermal diffusion. The described
+approach opens prospects for studying dynamics of ultrafast magnetic phenomena
+on nanometer length scales.",2009.13330v1
+2021-01-01,3D Simulations of Oxygen Shell Burning with and without Magnetic Fields,"We present a first 3D magnetohydrodynamic (MHD) simulation of convective
+oxygen and neon shell burning in a non-rotating $18\, M_\odot$ star shortly
+before core collapse to study the generation of magnetic fields in supernova
+progenitors. We also run a purely hydrodynamic control simulation to gauge the
+impact of the magnetic fields on the convective flow and on convective boundary
+mixing. After about 17 convective turnover times, the magnetic field is
+approaching saturation levels in the oxygen shell with an average field
+strength of $\mathord{\sim}10^{10}\, \mathrm{G}$, and does not reach kinetic
+equipartition. The field remains dominated by small to medium scales, and the
+dipole field strength at the base of the oxygen shell is only $10^{9}\,
+\mathrm{G}$. The angle-averaged diagonal components of the Maxwell stress
+tensor mirror those of the Reynolds stress tensor, but are about one order of
+magnitude smaller. The shear flow at the oxygen-neon shell interface creates
+relatively strong fields parallel to the convective boundary, which noticeably
+inhibit the turbulent entrainment of neon into the oxygen shell. The reduced
+ingestion of neon lowers the nuclear energy generation rate in the oxygen shell
+and thereby slightly slows down the convective flow. Aside from this indirect
+effect, we find that magnetic fields do not appreciably alter the flow inside
+the oxygen shell. We discuss the implications of our results for the subsequent
+core-collapse supernova and stress the need for longer simulations, resolution
+studies, and an investigation of non-ideal effects for a better understanding
+of magnetic fields in supernova progenitors.",2101.00213v2
+2021-01-04,Influence of the martensitic transformation kinetics on the magnetocaloric effect in Ni-Mn-In,"The inverse magnetocaloric effect (MCE) in Ni-Mn-based Heusler compounds
+occurs during the magnetostructural transition between low-temperature,
+low-magnetization martensite and high-temperature, high-magnetization
+austenite. In this study, we analyze the metamagnetic transformation of a
+$Ni_{49.8}Mn_{35}In_{15.2}$ compound by simultaneous adiabatic temperature
+change and strain measurements in pulsed magnetic fields up to 10 T. We observe
+an adiabatic temperature change of -10 K and a strain of -0.22 % when the
+reverse martensitic transition is fully induced at a starting temperature of
+285 K. By a variation of the magnetic field-sweep rates between 316 Ts$^{-1}$,
+865 Ts$^{-1}$ and 1850 Ts$^{-1}$, the transitional dynamics of the reverse
+martensitic transformation have been investigated. Our experiments reveal an
+apparent delay upon the end of the reverse martensitic transformation at field
+rates exceeding 865 Ts$^{-1}$ which is related to the annihilation of retained
+martensite. As a consequence, the field hysteresis increases and higher fields
+are required to saturate the transition. In contrast, no time-dependent effects
+on the onset of the reverse martensitic transformation were observed in the
+studied field-sweep range. Our results demonstrate that kinetic effects in
+Heusler compounds strongly affect the magnetic cooling cycle, especially when
+utilising a multicaloric ""exploiting-hysteresis cycle"" where high magnetic
+field-sweep rates are employed.",2101.00840v1
+2021-01-11,Strain Induced Anisotropic Magnetic Behaviour and Exchange Coupling Effect in Fe-SmCo$_{5}$ Permanent Magnets Generated by High Pressure Torsion,"High-pressure torsion (HPT), a technique of severe plastic deformation (SPD),
+is shown as a promising processing method for exchange-spring magnetic
+materials in bulk form. Powder mixtures of Fe and SmCo$_{5}$ are consolidated
+and deformed by HPT exhibiting sample dimensions of several millimetres, being
+essential for bulky magnetic applications. The structural evolution during HPT
+deformation of Fe-SmCo$_{5}$ compounds at room- and elevated- temperatures of
+chemical compositions consisting of 87, 47, 24 and 10 wt.% Fe is studied and
+microstructurally analysed. Electron microscopy and synchrotron X-ray
+diffraction reveal a dual-phase nanostructured composite for the as-deformed
+samples with grain refinement after HPT deformation. SQUID magnetometry
+measurements show hysteresis curves of an exchange coupled nanocomposite at
+room temperature, while for low temperatures a decoupling of Fe and SmCo$_{5}$
+is observed. Furthermore, exchange interactions between the hard- and
+soft-magnetic phase can explain a shift of the hysteresis curve. Strong
+emphasis is devoted to the correlation between the magnetic properties and the
+evolving nano-structure during HPT deformation, which is conducted for a 1:1
+composition ratio of Fe to SmCo$_{5}$. SQUID magnetometry measurements show an
+increasing saturation magnetisation for increasing strain $\gamma$ and a
+maximum of the coercive field strength at a shear strain of $\gamma$ = 75.",2101.03900v2
+2021-01-13,Quasi-one-dimensional magnetism in the spin-$\frac12$ antiferromagnet BaNa$_{2}$Cu(VO$_{4}$)$_{2}$,"We report synthesis and magnetic properties of quasi-one-dimensional
+spin-$\frac{1}{2}$ Heisenberg antiferromagnetic chain compound
+BaNa$_2$Cu(VO$_4$)$_2$. This orthovanadate has a centrosymmetric crystal
+structure, $C2/c$, where the magnetic Cu$^{2+}$ ions form spin chains. These
+chains are arranged in layers, with the chain direction changing by 62$^0$
+between the two successive layers. Alternatively, the spin lattice can be
+viewed as anisotropic triangular layers upon taking the inter-chain
+interactions into consideration. Despite this potential structural complexity,
+temperature-dependent magnetic susceptibility, heat capacity, ESR intensity,
+and NMR shift agree well with the uniform spin-$1/2$ Heisenberg chain model
+with an intrachain coupling of $J/k_{\rm B} \simeq 5.6$ K. The saturation field
+obtained from the magnetic isotherm measurement consistently reproduces the
+value of $J/k_{\rm B}$. Further, the $^{51}$V NMR spin-lattice relaxation rate
+mimics the 1D character in the intermediate temperature range, whereas magnetic
+long-range order sets in below $T_{\rm N} \simeq 0.25$ K. The effective
+interchain coupling is estimated to be $J_{\perp}/k_{\rm B} \simeq 0.1$ K. The
+theoretical estimation of exchange couplings using band-structure calculations
+reciprocate our experimental findings and unambiguously establish the 1D
+character of the compound. Finally, the spin lattice of BaNa$_2$Cu(VO$_4$)$_2$
+is compared with the chemically similar but not isostructural compound
+BaAg$_2$Cu(VO$_4)_2$.",2101.05120v1
+2021-02-04,Evaluating the reliability of a simple method to map the magnetic field azimuth in the solar chromosphere,"The Zeeman effect is of limited utility for probing the magnetism of the
+quiet solar chromosphere. The Hanle effect in some spectral lines is sensitive
+to such magnetism, but the interpretation of the scattering polarization
+signals requires taking into account that the chromospheric plasma is highly
+inhomogeneous and dynamic (i.e., that the magnetic field is not the only cause
+of symmetry breaking). Here we investigate the reliability of a well-known
+formula for mapping the azimuth of chromospheric magnetic fields directly from
+the scattering polarization observed in the \ion{Ca}{2}~8542~\AA\, line, which
+is typically in the saturation regime of the Hanle effect. To this end, we use
+the Stokes profiles of the \ion{Ca}{2}~8542~\AA\, line computed with the PORTA
+radiative transfer code in a three-dimensional (3D) model of the solar
+chromosphere, degrading them to mimic spectropolarimetric observations for a
+range of telescope apertures and noise levels. The simulated observations are
+used to obtain the magnetic field azimuth at each point of the field of view,
+which we compare with the actual values within the 3D model. We show that,
+apart from intrinsic ambiguities, the method provides solid results. Their
+accuracy depends more on the noise level than on the telescope diameter.
+Large-aperture solar telescopes, like DKIST and EST, are needed to achieve the
+required noise-to-signal ratios using reasonable exposure times.",2102.02880v1
+2021-03-05,Ferromagnetic Composite Self-Arrangement in Iron-Implanted Epitaxial Palladium Thin Films,"We report on the formation of the dilute $Pd_{1-x}Fe_x$ compositions with
+tunable magnetic properties under an ion-beam implantation of epitaxial Pd thin
+films. Binary $Pd_{1-x}Fe_x$ alloys with a mean iron content $x$ of $0.025$,
+$0.035$ or $0.075$ were obtained by the implantation of $40 keV$ $Fe^+$ ions
+into the palladium films on MgO (001) substrate to the doses of
+$0.5\cdot10^{16}, 1.0\cdot10^{16}$ and $3.0\cdot10^{16}$ $ions/cm^2$,
+respectively. Structural and magnetic studies have shown that iron atoms occupy
+regular fcc-lattice Pd-sites without the formation of any secondary
+crystallographic phase. All the iron implanted Pd films reveal ferromagnetism
+at low temperatures (below $200 K$) with both the Curie temperature and
+saturation magnetization determined by the implanted iron dose. In contrast to
+the magnetic properties of the molecular beam epitaxy grown $Pd_{1-x}Fe_x$
+alloy films with the similar iron contents, the Fe-implanted Pd films possess
+weaker in-plane magnetocrystalline anisotropy, and, accordingly, a lower
+coercivity. The observed multiple ferromagnetic resonances in the implanted
+$Pd_{1-x}Fe_x$ films indicate a formation of a magnetically inhomogeneous state
+due to spinodal decomposition into regions, presumably layers, with identical
+crystal symmetry but different iron contents. The multiphase magnetic structure
+is robust with respect to the vacuum annealing at $770 K$, though develops
+towards well-defined local $Pd-Fe$ compositions.",2103.03562v1
+2021-05-20,Spin dynamics of the quantum dipolar magnet Yb$_3$Ga$_5$O$_{12}$ in an external field,"We investigate ytterbium gallium garnet Yb$_{3}$Ga$_{5}$O$_{12}$ in the
+paramagnetic phase above the supposed magnetic transition at $T_{\lambda}
+\approx 54$ mK. Our study combines susceptibility and specific heat
+measurements with neutron scattering experiments and theoretical calculations.
+Below 500 mK, the elastic neutron response is strongly peaked in the momentum
+space. Along with that the inelastic spectrum develops flat excitation modes.
+In magnetic field, the lowest energy branch follows a Zeeman shift in
+accordance with the field-dependent specific heat data. An intermediate state
+with spin canting away from the field direction is evidenced in small magnetic
+fields. In the field of 2 T, the total magnetization almost saturates and the
+measured excitation spectrum is well reproduced by the spin-wave calculations
+taking into account solely the dipole-dipole interactions. The small positive
+Curie-Weiss temperature derived from the susceptibility measurements is also
+accounted for by the dipole spin model. Altogether, our results suggest that
+Yb$_{3}$Ga$_{5}$O$_{12}$ is a quantum dipolar magnet.",2105.09817v1
+2021-07-09,Electric field driven flat bands: Enhanced magnetoelectric and electrocaloric effects in frustrated quantum magnets,"The $J_1$-$J_2$ quantum spin sawtooth chain is a paradigmatic one-dimensional
+frustrated quantum spin system exhibiting unconventional ground-state and
+finite-temperature properties. In particular, it exhibits a flat energy band of
+one-magnon excitations accompanied by an enhanced magnetocaloric effect for two
+singular ratios of the basal interactions $J_1$ and the zigzag interactions
+$J_2$. In our paper, we demonstrate that one can drive the spin system into a
+flat-band scenario by applying an appropriate electric field, thus overcoming
+the restriction of fine-tuned exchange couplings $J_1$ and $J_2$ and allowing
+one to tune more materials towards flat-band physics, that is to show a
+macroscopic magnetization jump when crossing the magnetic saturation field, a
+residual entropy at zero temperature as well as an enhanced magnetocaloric
+effect. While the magnetic field acts on the spin system via the ordinary
+Zeeman term, the coupling of an applied electric field with the spins is given
+by the sophisticated Katsura-Nagaosa-Balatsky (KNB) mechanism, where the
+electric field effectively acts as a Dzyaloshinskii-Moriya spin-spin
+interaction. The resulting novel features are corresponding reciprocal effects:
+We find a magnetization jump driven by the electric field as well as a jump of
+the electric polarization driven by the magnetic field, i.e.\ the system
+exhibits an extraordinarily strong magnetoelectric effect. Moreover, in analogy
+to the enhanced magnetocaloric effect the system shows an enhanced
+electrocaloric effect.",2107.04371v2
+2021-11-11,Tuning the Room Temperature Ferromagnetism in Fe5GeTe2 by Arsenic Substitution,"In order to tune the magnetic properties of the cleavable high-Curie
+temperature ferromagnet Fe$_{5-x}$GeTe$_2$, the effect of increasing the
+electron count through arsenic substitution has been investigated. Small
+additions of arsenic (2.5 and 5%) seemingly enhance ferromagnetic order in
+polycrystalline samples by quenching fluctuations on one of the three magnetic
+sublattices, whereas larger As concentrations decrease the ferromagnetic Curie
+temperature ($T_{\rm C}$) and saturation magnetization. This work also
+describes the growth and characterization of Fe$_{4.8}$AsTe$_2$ single crystals
+that are structurally analogous to Fe$_{5-x}$GeTe$_2$ but with some phase
+stability complications. Magnetization measurements reveal dominant
+antiferromagnetic behavior in Fe$_{4.8}$AsTe$_2$ with a N\'{e}el temperature of
+$T_{\rm N}$ $\approx$42K. A field-induced spin-flop below $T_{\rm N}$ results
+in a switch from negative to positive magnetoresistance, with significant
+hysteresis causing butterfly-shaped resistance loops. In addition to reporting
+the properties of Fe$_{4.8}$AsTe$_2$, this work shows the importance of
+manipulating the individual magnetic sublattices in Fe$_{5-x}$GeTe$_2$ and
+motivates further efforts to control the magnetic properties in related
+materials by fine tuning of the Fermi energy or crystal chemistry.",2111.06439v1
+2021-11-20,Exchange coupling in synthetic anion-engineered chromia heterostructures,"Control of magnetic states by external factors has garnered a mainstream
+status in spintronic research for designing low power consumption and
+fast-response information storage and processing devices. Previously,
+magnetic-cation substitution is the conventional means to induce ferromagnetism
+in an intrinsic antiferromagnet. Theoretically, the anion-doping is proposed to
+be another effect means to change magnetic ground states. Here we demonstrate
+the synthesis of high-quality single-phase chromium oxynitride thin films using
+in-situ nitrogen doping. Unlike antiferromagnetic monoanionic chromium oxide
+and nitride phases, chromium oxynitride exhibits a robust ferromagnetic and
+insulating state, as demonstrated by the combination of multiple magnetization
+probes and theoretical calculations. With increasing the nitrogen content, the
+crystal structure of chromium oxynitride transits from trigonal (R3c) to
+tetragonal (4mm) phase and its saturation magnetization reduces significantly.
+Furthermore, we achieve a large and controllable exchange bias field in the
+chromia heterostructures by synthetic anion engineering. This work reflects the
+anion engineering in functional oxides towards the potential applications in
+giant magnetoresistance and tunnelling junctions of modern magnetic sensors and
+read heads.",2111.10564v1
+2021-11-23,"TaCo$_{2}$Te$_{2}$: An air-stable, magnetic van der Waals material with high mobility","Van der Waals (vdW) materials are an indispensable part of functional device
+technology due to their versatile physical properties and ease of exfoliating
+to the low-dimensional limit. Among all the compounds investigated so far, the
+search for magnetic vdW materials has intensified in recent years, fueled by
+the realization of magnetism in two dimensions (2D). However, metallic magnetic
+vdW systems are still uncommon. In addition, they rarely host high-mobility
+charge carriers, which is an essential requirement for high-speed electronic
+applications. Another shortcoming of 2D magnets is that they are highly air
+sensitive. Using chemical reasoning, we introduce TaCo2Te2 as an air-stable,
+high-mobility, magnetic vdW material. It has a layered structure, which
+consists of Peierls distorted Co chains and a large vdW gap between the layers.
+We find that the bulk crystals can be easily exfoliated and the obtained thin
+flakes are robust to ambient conditions after four months of monitoring using
+an optical microscope. We also observe signatures of canted antiferromagntic
+behavior at low-temperature. TaCo2Te2 shows a metallic character and a large,
+non-saturating, anisotropic magnetoresistance. Furthermore, our Hall data and
+quantum oscillation measurements reveal the presence of both electron- and
+hole-type carriers and their high mobility.",2111.12079v1
+2021-12-01,Pressure dependent magnetic properties on bulk CrBr3 single crystals,"The van der Waals class of materials offer an approach to two-dimensional
+magnetism as their spin fluctuations can be tuned upon exfoliation of layers.
+Moreover, it has recently been shown that spin-lattice coupling and long-range
+magnetic ordering can be modified with pressure in van der Waals materials. In
+this work, the magnetic properties of quasi two-dimensional CrBr3 are reported
+applying hydrostatic pressure. The application of pressure (0 - 0.8 GPa) shows
+a 72 % decrease in saturation magnetization with small decrease in the Curie
+temperature from 33 to 29 K. Density functional theory calculations with
+pressure up to 1 GPa show a reduction in volume and interplanar distance as
+pressure increases. To further understand magnetic properties with applied
+pressure, the magnetocrystalline anisotropy energy (MAE) and exchange coupling
+parameter (J) are calculated. There is minimal decrease in MAE and the first
+nearest neighbor interaction (J1) (U = 2.7 eV and J = 0.7 eV), shows an
+increase in J1 with respect to pressure. Overall, CrBr3 displays ferromagnetic
+interlayer coupling and the calculated exchange coupling and MAE parameters
+match well with the observations from the experimental work.",2112.00233v1
+2022-01-27,Robust antiferromagnetism in Y$_2$Co$_3$,"We report on a solution-growth based method to synthesise single crystals of
+Y$_2$Co$_3$ and on its structural and magnetic properties. We find that
+Y$_2$Co$_3$ crystallizes in the La2Ni3-type orthorhombic structure with space
+group Cmce (No. 64), with Co forming distorted kagome lattices. Y$_2$Co$_3$
+orders antiferromagnetically below $T_N$ = 252 K. Magnetization measurements
+reveal that the moments are primarily aligned along the b axis with evidence
+for some canting. Band-structure calculations indicate that ferromagnetic and
+antiferromagnetic orders are nearly degenerate, at odds with experimental
+results. Magnetization measurements under pressure up to 1 GPa reveal that the
+N/'eel temperature decreases with the slope of -1.69 K/GPa. We observe a
+field-induced spin-flop transition in the magnetization measurements at 1.5 K
+and 21 T with magnetic field along the b direction. The magnetization is not
+saturated up to 35 T, indicating that the antiferromagnetic ordering in
+Y$_2$Co$_3$ is quite robust, which is surprising for such a Co-rich
+intermetallic.",2201.11778v1
+2022-03-03,On large-scale dynamos with stable stratification and the application to stellar radiative zones,"Our understanding of large-scale magnetic fields in stellar radiative zones
+remains fragmented and incomplete. Such magnetic fields, which must be produced
+by some form of dynamo mechanism, are thought to dominate angular-momentum
+transport, making them crucial to stellar evolution. A major difficulty is the
+effect of stable stratification, which generally suppresses dynamo action. We
+explore the effects of stable stratification on mean-field dynamo theory with a
+particular focus on a non-helical large-scale dynamo (LSD) mechanism known as
+the magnetic shear-current effect. We find that the mechanism is robust to
+increasing stable stratification as long as the original requirements for its
+operation are met: a source of shear and non-helical magnetic fluctuations
+(e.g. from a small-scale dynamo). Both are plausibly sourced in the presence of
+differential rotation. Our idealized direct numerical simulations, supported by
+mean-field theory, demonstrate the generation of near equipartition large-scale
+toroidal fields. Additionally, a scan over magnetic Reynolds number shows no
+change in the growth or saturation of the LSD, providing good numerical
+evidence of a dynamo mechanism resilient to catastrophic quenching, which has
+been an issue for helical dynamos. These properties -- the absence of
+catastrophic quenching and robustness to stable stratification -- make the
+mechanism a plausible candidate for generating in-situ large-scale magnetic
+fields in stellar radiative zones.",2203.01943v2
+2022-05-12,Magnetization of Zn1-xCoxO nanoparticles: single-ion anisotropy and spin clustering,"The magnetization of Zn1-xCoxO (0.0055 < x < 0.073) nanoparticles has been
+measured as a function of temperature T (1.7 K < T , 10 K) and for magnetic
+field up to 65 kOe using a SQUID magnetometer. Samples were synthesized by
+three different growth methods: microwave-assisted hydrothermal, combustion
+reaction and sol-gel. For all studied samples, the magnetic properties derive
+from the antiferromagnetic (AF) spin clustering due to the Co2+ nearest
+neighbors. At T >= 6 K, the magnetization of the Co2+ ions has a Brillouin-type
+behavior, but below 6 K, it shows a notable deviation. We have shown that the
+observed deviation may be derived from single-ion anisotropy (SIA) with
+uniaxial symmetry. Results of fits show that the axial-SIA parameter D
+(typically D = 4.4 K) is slightly larger that the bulk value D = 3.97 K. No
+significant change of D has been observed as a function of the Co concentration
+or the growth process. For each sample, the SIA fit gave also the effective
+concentration (x) corresponding to the technical saturation value of the
+magnetization. Comparison of the concentration dependence of x with predictions
+based on cluster models shows an enhancement of the AF spin clustering
+independent of the growth method. This is ascribed to a clamped non-random
+distribution of the cobalt ions in the nanoparticles. The approach of the local
+concentration (xL) has been used to quantify the observed deviation from
+randomicity. Assuming a ZnO core/ Zn1-xCoxO shell nanoparticle, the thickness
+of the shell has been determined from the ratio xL/x.",2205.06213v1
+2022-08-09,"Structural, magnetic and transport properties of Co$_2$CrAl epitaxial thin films","We report the physical properties of Co$_2$CrAl Heusler alloy epitaxial thin
+films grown on single crystalline MgO(001) substrate using pulsed laser
+deposition technique. The x-ray diffraction pattern in $\theta$-2$\theta$ mode
+showed the film growth in single phase B2-type ordered cubic structure with the
+presence of (002) and (004) peaks, and the film oriented along the MgO(001)
+direction. The $\phi$~scan along the (220) plane confirms the four-fold
+symmetry and the epitaxial growth relation found to be
+Co$_2$CrAl(001)[100]$\vert$$\vert$MgO(001)[110]. The thickness of about 12~nm
+is extracted through the analysis of x-ray reflectivity data. The isothermal
+magnetization (M--H) curves confirm the ferromagnetic (FM) nature of the thin
+film having significant hysteresis at 5 and 300~K. From the in-plane M--H
+curves, the saturation magnetization values are determined to be
+2.1~$\mu$$_{\rm B}$/f.u.~at 5~K and 1.6~$\mu$$_{\rm B}$/f.u. at 300~K, which
+suggests the soft FM behavior in the film having the coercive field $\approx$
+522~Oe at 5~K. The thermo-magnetization measurements at 500~Oe magnetic field
+show the bifurcation between field-cooled and zero-field-cooled curves below
+about 100~K. The normalized field-cooled magnetization curve follows the T$^2$
+dependency, and the analysis reveal the Curie temperature around 335$\pm$11~K.
+Moreover, the low-temperature resistivity indicates semiconducting behavior
+with the temperature, and we find a negative temperature coefficient of
+resistivity (5.2 $\times$ 10$^{-4}$ /K).",2208.04687v1
+2022-10-14,Linear colossal magnetoresistance driven by magnetic textures in LaTiO3 thin films on SrTiO3,"Linear magnetoresistance (LMR) is of particular interest for memory,
+electronics, and sensing applications, especially when it does not saturate
+over a wide range of magnetic fields. One of its principal origins is local
+mobility or density inhomogeneities, often structural, which in the
+Parish-Littlewood theory leads to an unsaturating LMR proportional to mobility.
+Structural disorder, however, also tends to limit the mobility and hence the
+overall LMR amplitude. An alternative route to achieve large LMR is via
+non-structural inhomogeneities which do not affect the zero field mobility,
+like magnetic domains. Here, linear positive magnetoresistance caused by
+magnetic texture is reported in \ch{LaTiO3}/\ch{SrTiO3} heterostructures. The
+LMR amplitude reaches up to 6500\% at 9T. This colossal value is understood by
+the unusual combination of a very high thin film mobility, up to 40 000
+cm$^2$/V.s, and a very large coverage of low-mobility regions. These regions
+correlate with a striped magnetic structure, compatible with a spiral magnetic
+texture in the \ch{LaTiO3} film, revealed by low temperature Lorentz
+transmission electron microscopy. These results provide a novel route for the
+engineering of large-LMR devices.",2210.07682v1
+2022-11-01,Magnetically Dominated Disks in Tidal Disruption Events and Quasi-Periodic Eruptions,"The classical radiation pressure instability has been a persistent
+theoretical feature of thin, radiatively efficient accretion disks with
+accretion rates 1 to 100 per cent of the Eddington rate. But there is only
+limited evidence of its occurrence in nature: rapid heartbeat oscillations of a
+few X-ray binaries and now, perhaps, the new class of hourly X-ray transients
+called quasi-periodic eruptions (QPEs). The accretion disks formed in tidal
+disruption events (TDEs) have been observed to peacefully trespass through the
+range of unstable accretion rates without exhibiting any clear sign of the
+instability. We try to explain the occurrence or otherwise of this instability
+in these systems, by constructing steady state 1D models of thin magnetic
+accretion disks. The local magnetic pressure in the disk is assumed to be
+dominated by toroidal fields arising from a dynamo sourced by
+magneto-rotational instability (MRI). We choose a physically motivated
+criterion of MRI saturation, validated by recent magnetohydrodynamic
+simulations, to determine the strength of magnetic pressure in the disk. The
+resulting magnetic pressure support efficiently shrinks: (1) the parameter
+space of unstable mass accretion rates, explaining the absence of instability
+in systems such as TDEs and (2) the range of unstable radii in the inner
+accretion disk, which can shorten the quasi-periods of instability limit-cycles
+by more than three orders of magnitude, explaining the observed periods ( a few
+hrs) of QPEs. In addition to examining stability properties of strongly
+magnetized disks, we predict other observational signatures such as spectral
+hardening factors and jet luminosities to test the compatibility of our disk
+models with observations of apparently stable TDE disks.",2211.00704v1
+2022-12-21,Charge transfer and disorder-induced spin relaxation in La2NiMnO6 crystallites,"Investigation of the electronic and spin structure in double perovskites is
+recently attracting significant attention, mainly driven by their unique
+multifunctional properties and other underlying charge and spin dynamics.
+Herein, using X-ray photoelectron spectroscopy (XPS), we explore the influence
+of variable fractions of Mn3+/Mn4+ cation in different crystallite sizes of
+La2NiMnO6 that control the various completing exchange interactions of Ni/Mn
+cations responsible for multiple magnetic transitions. The enhanced itinerant
+electron due to Mn4+ + Ni2+ to Mn3+ + Ni3+ charge transfer emerged as a
+shoulder like characteristics at the low binding energy in the Mn-2P core-level
+spectrum. The various approaches such as difference in saturation
+magnetization, presence of multiple charge valance, and magnetic entropy
+calculations confirm the presence of antisites disorder and it varies as a
+function of milling. As milling provides excess energy that helps with
+nucleation or cation ordering. Competing magnetic interactions driven by mixed
+valences and disorder were established across a cluster glassy phase in the
+crystallites. Electron spin resonance spectroscopy (ESR) was utilized to probe
+the temperature-driven ferromagnetic-cluster spin-glass transition with
+modified g-factor ranging from 2.050 to 2.037. The line width of the ESR
+signals increases across the ferromagnetic to cluster-glass phase transition
+due to spin freezing. This phase transition is further characterized by
+temperature-dependent ac-magnetic susceptibility measurements. Argand diagram
+for the ac-susceptibility of the interacting crystallites suggests a collective
+magnetization relaxation dynamic in the proximity of spin-glass freezing
+temperature of La2NiMnO6.",2212.10845v2
+2023-02-22,Magnetized fingering convection in stars,"Fingering convection (also known as thermohaline convection) is a process
+that drives the vertical transport of chemical elements in regions of stellar
+radiative zones where the mean molecular weight increases with radius.
+Recently, Harrington & Garaud (2019) used three-dimensional direct numerical
+simulations to show that a vertical magnetic field can dramatically enhance the
+rate of chemical mixing by fingering convection. Furthermore, they proposed a
+so-called ""parasitic saturation"" theory to model this process. Here, we test
+their model over a broad range of parameter space, using a suite of direct
+numerical simulations of magnetized fingering convection varying the magnetic
+Prandtl number, magnetic field strength, and composition gradient. We find that
+the rate of chemical mixing measured in the simulations is not always predicted
+accurately by their existing model, in particular when the magnetic diffusivity
+is large. We then present an extension of the Harrington & Garaud (2019) model
+which resolves this issue. When applied to stellar parameters, it recovers the
+results of Harrington & Garaud (2019) except in the limit where fingering
+convection becomes marginally stable, where the new model is preferred. We
+discuss the implications of our findings for stellar structure and evolution.",2302.11610v3
+2023-03-20,Constraining atmospheric parameters and surface magnetic fields with $\texttt{ZeeTurbo}$: an application to SPIRou spectra,"We report first results on a method aimed at simultaneously characterising
+atmospheric parameters and magnetic properties of M dwarfs from high-resolution
+nIR spectra recorded with SPIRou in the framework of the SPIRou Legacy Survey.
+Our analysis relies on fitting synthetic spectra computed from MARCS model
+atmospheres to selected spectral lines, both sensitive and insensitive to
+magnetic fields. We introduce a new code, $\texttt{ZeeTurbo}$, obtained by
+including the Zeeman effect and polarised radiative transfer capabilities to
+$\texttt{Turbospectrum}$. We compute a grid of synthetic spectra with
+$\texttt{ZeeTurbo}$ for different magnetic field strengths and develop a
+process to simultaneously constrain $T_{\rm eff}$, $\log{g}$, [M/H],
+[$\alpha$/Fe] and the average surface magnetic flux. In this paper, we present
+our approach and assess its performance using simulations, before applying it
+to six targets observed in the context of the SPIRou Legacy Survey (SLS),
+namely AU Mic, EV Lac, AD Leo, CN Leo, PM J18482+0741, and DS Leo. Our method
+allows us to retrieve atmospheric parameters in good agreement with the
+literature, and simultaneously yields surface magnetic fluxes in the range 2-4
+kG with a typical precision of 0.05 kG, in agreement with literature estimates,
+and consistent with the saturated dynamo regime in which most of these stars
+are.",2303.11241v1
+2023-06-21,"First-principles prediction of structural, magnetic properties of Cr-substituted strontium hexaferrite, and its site preference","To investigate the structural and magnetic properties of Cr-doped M-type
+strontium hexaferrite (SrFe$_{12}$O$_{19}$) with x = (0.0, 0.5, 1.0), we
+perform first-principles total-energy calculations relied on density functional
+theory. Based on the calculation of the substitution energy of Cr in strontium
+hexaferrite and formation probability analysis, we conclude that the doped Cr
+atoms prefer to occupy the 2a, 12k, and 4f$_{2}$ sites which is in good
+agreement with the experimental findings. Due to Cr$^{3+}$ ion moment, 3
+{$\mu_B$}, smaller than that of Fe$^{3+}$ ion, 5 {$\mu_B$}, saturation
+magnetization (M$_{s}$) reduce rapidly as the concentration of Cr increases in
+strontium hexaferrite. The magnetic anisotropic field $\left(H_{a}\right)$
+rises with an increasing fraction of Cr despite a significant reduction of
+magnetization and a slight increase of magnetocrystalline anisotropy
+$\left(K_{1}\right)$.The cause for the rise in magnetic anisotropy field
+$\left(H_{a}\right)$ with an increasing fraction of Cr is further emphasized by
+our formation probability study. Cr$^{3+}$ ions prefer to occupy the 2a sites
+at lower temperatures, but as the temperature rises, it is more likely that
+they will occupy the 12k site. Cr$^{3+}$ ions are more likely to occupy the 12k
+site than the 2a site at a specific annealing temperature (>700{\deg}C).",2306.11952v1
+2023-06-27,MHD Simulation in Galactic Center Region with Radiative Cooling and Heating,"We investigate the role of magnetic field on the gas dynamics in a galactic
+bulge region by three dimensional simulations with radiative cooling and
+heating. While high-temperature corona with $T>10^6\ {\rm K}$ is formed in the
+halo regions, the temperature near the mid-plane is $\lesssim 10^4\ {\rm K}$
+following the thermal equilibrium curve determined by the radiative cooling and
+heating. Although the thermal energy of the interstellar gas is lost by
+radiative cooling, the saturation level of the magnetic field strength does not
+significantly depend on the radiative cooling and heating. The magnetic field
+strength is amplified to $10\ {\rm \mu G}$ on average, and reaches several
+hundred ${\rm \mu G}$ locally. We find the formation of magnetically dominated
+regions at mid-latitudes in the case with the radiative cooling and heating,
+which is not seen in the case without radiative effect. The vertical thickness
+of the mid-latitude regions is $50-150\ {\rm pc}$ at the radial location of
+$0.4-0.8\ {\rm kpc}$ from the galactic center, which is comparable to the
+observed vertical distribution of neutral atomic gas. When we take the average
+of different components of energy density integrated over the galactic bulge
+region, the magnetic energy is comparable to the thermal energy. We conclude
+that the magnetic field plays a substantial role in controlling the dynamical
+and thermal properties of the galactic bulge region.",2306.15761v2
+2023-10-29,Bridging Scales in Black Hole Accretion and Feedback: Magnetized Bondi Accretion in 3D GRMHD,"Fueling and feedback couple supermassive black holes (SMBHs) to their host
+galaxies across many orders of magnitude in spatial and temporal scales, making
+this problem notoriously challenging to simulate. We use a multi-zone
+computational method based on the general relativistic magneto-hydrodynamic
+(GRMHD) code KHARMA that allows us to span $7$ orders of magnitude in spatial
+scale, to simulate accretion onto a non-spinning SMBH from an external medium
+with Bondi radius $R_B\approx 2\times 10^5 \,GM_\bullet/c^2$, where $M_\bullet$
+is the SMBH mass. For the classic idealized Bondi problem, spherical gas
+accretion without magnetic fields, our simulation results agree very well with
+the general relativistic analytic solution. Meanwhile, when the accreting gas
+is magnetized, the SMBH magnetosphere becomes saturated with a strong magnetic
+field. The density profile varies as $\sim r^{-1}$ rather than $r^{-3/2}$ and
+the accretion rate $\dot{M}$ is consequently suppressed by over 2 orders of
+magnitude below the Bondi rate $\dot{M}_B$. We find continuous energy feedback
+from the accretion flow to the external medium at a level of
+$\sim10^{-2}\dot{M}c^2 \sim 5\times 10^{-5} \dot{M}_B c^2$. Energy transport
+across these widely disparate scales occurs via turbulent convection triggered
+by magnetic field reconnection near the SMBH. Thus, strong magnetic fields that
+accumulate on horizon scales transform the flow dynamics far from the SMBH and
+naturally explain observed extremely low accretion rates compared to the Bondi
+rate, as well as at least part of the energy feedback.",2310.19135v2
+2023-11-30,Induced quantum magnetism in CEF singlet ground state models: Thermodynamics and excitations,"We present a comparative investigation of singlet ground state induced
+magnetism for singlet, doublet and triplet excited CEF states of non-Kramers
+f-electrons relevant primarily for Pr- and U- based compounds. This type of
+magnetic order is of intrinsic quantum nature because it requires the
+superposition of singlet ground state with excited states due to non-diagonal
+matrix elements of the effective intersite exchange to generate local moments.
+In contrast to conventional magnets the local moments and their ordering appear
+simultaneously at the transition temperature. It is finite only if the control
+parameter proportional to the ratio of exchange strength to level splitting
+exceeds a critical value marking the quantum critical point of the models. We
+determine the dependence of transition temperature, saturation moment,
+renormalised level splitting, specific heat jumps and low-temperature
+susceptibility as function of control parameter. Furthermore the temperature
+dependence of these quantities is calculated for control parameters above and
+below the quantum critical point and the distinction to conventional magnetism
+is discussed. In addition we investigate the dynamical properties of the three
+models, deriving the magnetic exciton dispersion and their critical behaviour.
+In particular the conditions for true and arrested soft-mode behaviour at the
+ordering wave vector are identified.",2311.18416v2
+2023-12-04,Survival of magnetic correlations above ordering temperature in a ferromagnetically ordered classical kagomé magnet: Li9Cr3(P2O7)3(PO4)2,"Motivated by the recent discovery of a semiclassical nematic spin liquid
+state in a Heisenberg kagom\'e antiferromagnet Li9Fe3(P2O7)3(PO4)2 (LFPO) with
+S=5/2 [Kermarrec et al. Phys. Rev. Lett. 127, 157202 (2021)], we now
+investigate the impact of spin quantum number S on the ground state properties
+by studying the isostructural kagom\'e magnet Li9Cr3(P2O7)3(PO4)2 (LCPO) with
+active t2g orbitals and S = 3/2. Thermodynamic measurements reveal that the
+ground state properties of LCPO is dominated by the ferromagnetic interactions
+with a mean-field temperature $\theta \sim$ 3 K (J < 1 K) and the ordering
+temperature, Tc ~ 2.7 K, and the size of the ordered moment $\sim 1.05 \pm 0.25
+$ ~${\mu}_B$ is significantly reduced from that of a fully ordered moment. The
+ab initio electronic structure calculations nicely corroborate the
+thermodynamic results and suggest the presence of additional in and
+out-of-plane further neighbor antiferromagnetic couplings, though significantly
+weaker in comparison to the dominant first-nearest neighbor ferromagnetic
+coupling. The spin-lattice relaxation rate measured with fields larger than the
+saturation field shows a magnetic field induced gap ($\Delta \propto B$) in the
+excitation spectrum, and in $B \rightarrow 0$ limit the gap has a finite
+intercept ~ 3 K, equivalent to the mean-field scale. We interpret the origin of
+this gap is associated with the magnetic interactions inherent to the material.
+With our experimental results, we establish the stabilization of a
+ferromagnetic like ground state and the persistence of magnetic-correlations
+above the ordering temperature in LCPO.",2312.01731v1
+2023-12-09,Bachelorthesis: Calculation of the magnetic properties of quarternary ThMn$_{12}$-type compounds with Zr as a substitution for Nd,"This research aims to identify an alternative solution for the
+Nd$_2$Fe$_{14}$B magnet in light of the scarcity of rare earth (RE) resources.
+The investigation uses density functional theory (DFT) calculations to assess
+the effect of partial substitution of Nd with the transition metal (TM) Zr
+within the ThMn$_{12}$ structure, focusing specifically on the
+(Zr$_{0.5}$Nd$_{0.5}$)Fe$_{11}$Ti compound. In order to gain a comprehensive
+understanding, an investigation of intrinsic and magnetic properties, including
+saturation magnetisation ($M_S$), Curie temperature ($T_C$) and magnetic
+anisotropy energy (MAE), is carried out on binary to quinary compounds
+RFe$_{11-y}$Ti$_{y}$ (R: Nd, Zr and Zr$_{0.5}$Nd$_{0.5}$, y: $0 \leq y \leq 1$)
+and (Zr$_{0.5}$Nd$_{0.5}$)Fe$_{10}$CoTi. The substitution of Ti at different
+concentrations for thermodynamic stabilisation is studied in ternary and
+quaternary compounds RFe$_{12-y}$Ti$_y$ ($0 \leq y \leq 1$). In addition, the
+influence of Co on phase stability and intrinsic magnetic properties is studied
+in the quinary compound (Zr$_{0.5}$Nd$_{0.5}$)Fe$_{10}$CoTi. Special attention
+is given to the treatment of the 4$f$-electrons of Nd and their interaction
+with the 3$d$-electrons. Theoretical results are compared with available
+experimental data, although the limited availability of data, especially for
+Zr-containing compounds, limits the scope of such comparisons. Based on the
+literature and the calculations of binary and ternary compounds, the
+calculations of quaternary and quinary compounds are encouraged. Promising
+magnetic properties of an Nd-lean quaternary compound suitable for engineering
+applications have been identified.",2312.14951v1
+2024-01-22,The polarization of the solar Ba II D1 line with partial frequency redistribution and its magnetic sensitivity,"We investigate the main physical mechanisms that shape the intensity and
+polarization of the Ba II D1 line at 4934 angstroms via radiative transfer
+numerical experiments. We focus especially on the scattering linear
+polarization arising from the spectral structure of the anisotropic radiation
+in the wavelength interval spanned by the line's hyperfine structure (HFS)
+components in the odd isotopes of barium. After verifying that the presence of
+the low-energy metastable levels only impacts the amplitude, but not the shape,
+of the D1 linear polarization, we relied on a two-term atomic model that
+neglects such metastable levels but includes HFS. The D1 fractional linear
+polarization shows a very small variation with the choice of atmospheric model,
+enhancing its suitability for solar magnetic field diagnostics. Tangled
+magnetic fields with strengths of tens of gauss reduce the linear polarization
+and saturation is reached at roughly 300 G. Deterministic inclined magnetic
+fields produce a U/I profile and, if they have a significant longitudinal
+component, a V/I profile, whose modeling requires accounting for HFS and the
+Paschen-Back effect. Because of the overlap between HFS components, the
+magnetograph formula cannot be applied to infer the longitudinal magnetic
+field. Accurately modeling the D1 intensity and polarization requires an atomic
+system that includes the metastable levels and the HFS, the detailed spectral
+structure of the radiation field, the incomplete Paschen-Back regime for
+magnetic fields, and an accurate treatment of collisions.",2401.12303v1
+2009-10-12,Frustrated square lattice with spatial anisotropy: crystal structure and magnetic properties of PbZnVO(PO4)2,"Crystal structure and magnetic properties of the layered vanadium phosphate
+PbZnVO(PO4)2 are studied using x-ray powder diffraction, magnetization and
+specific heat measurements, as well as band structure calculations. The
+compound resembles AA'VO(PO4)2 vanadium phosphates and fits to the extended
+frustrated square lattice model with the couplings J(1), J(1)' between
+nearest-neighbors and J(2), J(2)' between next-nearest-neighbors. The
+temperature dependence of the magnetization yields estimates of averaged
+nearest-neighbor and next-nearest-neighbor couplings, J(1) ~ -5.2 K and J(2) ~
+10.0 K, respectively. The effective frustration ratio alpha=J(2)/J(1) amounts
+to -1.9 and suggests columnar antiferromagnetic ordering in PbZnVO(PO4)2.
+Specific heat data support the estimates of J(1) and J(2) and indicate a likely
+magnetic ordering transition at 3.9 K. However, the averaged couplings
+underestimate the saturation field, thus pointing to the spatial anisotropy of
+the nearest-neighbor interactions. Band structure calculations confirm the
+identification of ferromagnetic J(1), J(1)' and antiferromagnetic J(2), J(2)'
+in PbZnVO(PO4)2 and yield J(1)'-J(1) ~ 1.1 K in excellent agreement with the
+experimental value of 1.1 K, deduced from the difference between the expected
+and experimentally measured saturation fields. Based on the comparison of
+layered vanadium phosphates with different metal cations, we show that a
+moderate spatial anisotropy of the frustrated square lattice has minor
+influence on the thermodynamic properties of the model. We discuss relevant
+geometrical parameters, controlling the exchange interactions in these
+compounds, and propose a new route towards strongly frustrated square lattice
+materials.",0910.2258v1
+2013-05-09,A study of large scale dynamo growth rates from numerical simulations and implications for mean field theories,"Understanding large scale magnetic field growth in turbulent plasmas in the
+magnetohydrodynamic limit is a goal of magnetic dynamo theory. In particular,
+assessing how well large scale helical field growth and saturation in
+simulations matches that predicted by existing theories is important for
+progress. Using numerical simulations of isotropically forced turbulence
+without large scale shear with the implications, we focus on several aspects of
+this comparison that have not been previously tested: (1) Leading mean field
+dynamo theories which break the field into large and small scales predict that
+large scale helical field growth rates are determined by the difference between
+kinetic helicity and current helicity with no dependence on the non-helical
+energy in small scale magnetic fields. Our simulations show that the growth
+rate of the large scale field from fully helical forcing is indeed unaffected
+by the presence or absence of small scale magnetic fields amplified in a
+precursor non-helical dynamo. However, because the precursor non helical dynamo
+in our simulations produced fields that were strongly sub-equipartition with
+respect to the kinetic energy, we cannot yet rule out the potential influence
+of stronger non- helical small scale fields. (2) We have identified two
+features in our simulations which cannot be explained by the most minimalist
+versions of two-scale mean field theory: (i) fully helical small scale forcing
+produces significant non-helical large scale magnetic energy and (ii) the
+saturation of the large scale field growth is time-delayed with respect to what
+minimalist theory predicts. We comment on desirable generalizations to the
+theory in this context and future desired work.",1305.2080v2
+2015-10-30,"Vertical Equilibrium, Energetics, and Star Formation Rates in Magnetized Galactic Disks Regulated by Momentum Feedback from Supernovae","Recent hydrodynamic (HD) simulations have shown that galactic disks evolve to
+reach well-defined statistical equilibrium states. The star formation rate
+(SFR) self-regulates until energy injection by star formation feedback balances
+dissipation and cooling in the interstellar medium (ISM), and provides vertical
+pressure support to balance gravity. In this paper, we extend our previous
+models to allow for a range of initial magnetic field strengths and
+configurations, utilizing three-dimensional, magnetohydrodynamic (MHD)
+simulations. We show that a quasi-steady equilibrium state is established as
+rapidly for MHD as for HD models unless the initial magnetic field is very
+strong or very weak, which requires more time to reach saturation. Remarkably,
+models with initial magnetic energy varying by two orders of magnitude approach
+the same asymptotic state. In the fully saturated state of the fiducial model,
+the integrated energy proportions E_kin:E_th:E_mag,t:E_mag,o are
+0.35:0.39:0.15:0.11, while the proportions of midplane support
+P_turb:P_th:\Pi_mag,t:\Pi_mag,o are 0.49:0.18:0.18:0.15. Vertical profiles of
+total effective pressure satisfy vertical dynamical equilibrium with the total
+gas weight at all heights. We measure the ""feedback yields""
+\eta_c=P_c/\Sigma_SFR (in suitable units) for each pressure component, finding
+that \eta_turb~4 and \eta_th~1 are the same for MHD as in previous HD
+simulations, and \eta_mag,t~1. These yields can be used to predict the
+equilibrium SFR for a local region in a galaxy based on its observed gas and
+stellar surface densities and velocity dispersions. As the ISM weight (or
+dynamical equilibrium pressure) is fixed, an increase in $\eta$ from turbulent
+magnetic fields reduces the predicted \Sigma_SFR by ~25% relative to the HD
+case.",1511.00010v1
+2016-08-05,Domain Wall Spin Structures in Mesoscopic Fe Rings probed by High Resolution SEMPA,"We present a combined theoretical and experimental study of the energetic
+stability and accessibility of different domain wall spin configurations in
+mesoscopic magnetic iron rings. The evolution is investigated as a function of
+the width and thickness in a regime of relevance to devices, while Fe is chosen
+as a material due to its simple growth in combination with attractive magnetic
+properties including high saturation magnetization and low intrinsic
+anisotropy. Micromagnetic simulations are performed to predict the lowest
+energy states of the domain walls, which can be either the transverse or vortex
+wall spin structure, in good agreement with analytical models, with simulations
+revealing the expected low temperature configurations observable on relaxation
+of the magnetic structure from saturation in an external field. In the latter
+case, following the domain wall nucleation process, transverse domain walls are
+found at larger widths and thicknesses than would be expected by comparing the
+competing energy terms demonstrating the importance of metastability of the
+states. The simulations are compared to high resolution experimental images of
+the magnetization using scanning electron microscopy with polarization analysis
+to provide a phase diagram of the various spin configurations. In addition to
+the vortex and simple symmetric transverse domain wall, a significant range of
+geometries are found to exhibit highly asymmetric transverse domain walls with
+properties distinct from the symmetric transverse wall. Simulations of the
+asymmetric walls reveal an evolution of the domain wall tilting angle with ring
+thickness. Analysis of all the data reveals that in addition to the geometry,
+the influence of materials properties, defects and thermal activation all need
+to be taken into account in order to understand and reliably control the
+experimentally accessible states, as needed for devices.",1608.01981v1
+2017-08-21,Quasi-two-dimensional nonlinear evolution of helical magnetorotational instability in a magnetized Taylor-Couette flow,"Magnetorotational instability (MRI) is one of the fundamental processes in
+astrophysics, driving angular momentum transport and mass accretion in a wide
+variety of cosmic objects. Despite much theoretical/numerical and experimental
+efforts over the last decades, its saturation mechanism and amplitude, which
+sets the angular momentum transport rate, remains not well understood,
+especially in the limit of high resistivity, or small magnetic Prandtl numbers
+typical to interiors (dead zones) of protoplanetary disks, liquid cores of
+planets and liquid metals in laboratory. Using direct numerical simulations, in
+this paper we investigate the nonlinear development and saturation properties
+of the helical magnetorotational instability (HMRI) -- a relative of the
+standard MRI -- in a magnetized Taylor-Couette flow at very low magnetic
+Prandtl number (correspondingly at low magnetic Reynolds number) relevant to
+liquid metals. For simplicity, the ratio of azimuthal field to axial field is
+kept fixed. From the linear theory of HMRI, it is known that the Elsasser
+number, or interaction parameter determines its growth rate and plays a special
+role in the dynamics. We show that this parameter is also important in the
+nonlinear problem. By increasing its value, a sudden transition from weakly
+nonlinear, where the system is slightly above the linear stability threshold,
+to strongly nonlinear, or turbulent regime occurs. We calculate the azimuthal
+and axial energy spectra corresponding to these two regimes and show that they
+differ qualitatively. Remarkably, the nonlinear state remains in all cases
+nearly axisymmetric suggesting that HMRI turbulence is quasi two-dimensional in
+nature. Although the contribution of non-axisymmetric modes increases
+moderately with the Elsasser number, their total energy remains much smaller
+than that of the axisymmetric ones.",1708.06148v2
+2021-12-20,One-dimensional magnetism in a facile spin 1/2 Heisenberg antiferromagnet with a low saturation field,"This work reports the synthesis, structure and magnetic properties of the
+single crystal of a facile spin 1/2 one dimensional Heisenberg antiferromagnet
+bis(4-aminopyridinium) bis(oxalato)cuprate(II) dihydrate, (C 5 H 7 N 2 ) 2
+[Cu(C 2 O 4 ) 2 ].2H 2 O. Single crystals of large sizes of the title compound
+were obtained using the technique of liquid-liquid diffusion or layer diffusion
+with 100 % yield. Single crystal X-ray diffraction measurements revealed a very
+good quality of the grown single crystals with small value of goodness of fit R
+obtained at 1.058. The structure comprises corner-sharing CuO 6 octahedra
+resulting in Cu-Cu chains in the a-direction that are very well isolated in the
+b and c directions. Density functional theory (DFT) with three different basis
+sets (B3LYP/6-311++G(d,p); B3LYP/LanL2DZ and B3LYP/6-311++G(d,p),
+B3LYP/LanL2DZ) generated the optimized geometry of a monomeric unit as well as
+its vibrational spectra. The vibrational frequency corresponding to the CuO 6
+octahedron was found in the experimentally obtained IR spectrum that matched
+very well with the theoretically obtained IR spectra incorporating the mixed
+basis. Temperature dependent dc magnetic susceptibility revealed a low
+temperature peak suggesting the presence of low dimensional magnetism in the
+system. Bonner-Fisher fit confirmed the one dimensional nature of the magnetic
+interaction with an exchange coupling constant of 1.23 K. Magnetisation
+measurements along with Quantum Monte Carlo simulations confirm this
+metal-organic crystal to be a very good spin-1/2 Heisenberg antiferromagnet
+with a low saturation field H s of 1.75 T.",2112.10639v2
+2022-08-05,Near-cancellation of up- and down-gradient momentum transport in forced magnetized shear-flow turbulence,"Visco-resistive magnetohydrodynamic turbulence, driven by a two-dimensional
+unstable shear layer that is maintained by an imposed body force, is examined
+by decomposing it into dissipationless linear eigenmodes of the initial
+profiles. The down-gradient momentum flux, as expected, originates from the
+large-scale instability. However, continual up-gradient momentum transport by
+large-scale linearly stable but nonlinearly excited eigenmodes is identified,
+and found to nearly cancel the down-gradient transport by unstable modes. The
+stable modes effectuate this by depleting the large-scale turbulent
+fluctuations via energy transfer to the mean flow. This establishes a physical
+mechanism underlying the long-known observation that coherent vortices formed
+from nonlinear saturation of the instability reduce turbulent transport and
+fluctuations, as such vortices are composed of both the stable and unstable
+modes, which are nearly equal in their amplitudes. The impact of magnetic
+fields on the nonlinearly excited stable modes is then quantified. Even when
+imposing a strong magnetic field that almost completely suppresses the
+instability, the up-gradient transport by the stable modes is at least
+two-thirds of the down-gradient transport by the unstable modes, whereas for
+weaker fields, this fraction reaches up to $98\%$. These effects are persistent
+with variations in magnetic Prandtl number and forcing strength. Finally,
+continuum modes are shown to be energetically less important, but essential for
+capturing the magnetic fluctuations and Maxwell stress. A simple analytical
+scaling law is derived for their saturated turbulent amplitudes. It predicts
+the fall-off rate as the inverse of the Fourier wavenumber, a property which is
+confirmed in numerical simulations.",2208.03342v1
+2022-10-10,Magnetic fields do not suppress global star formation in low metallicity dwarf galaxies,"Many studies concluded that magnetic fields suppress star formation in
+molecular clouds and Milky Way like galaxies. However, most of these studies
+are based on fully developed fields that have reached the saturation level,
+with little work on investigating how an initial weak primordial field affects
+star formation in low metallicity environments. In this paper, we investigate
+the impact of a weak initial field on low metallicity dwarf galaxies. We
+perform high-resolution AREPO simulations of five isolated dwarf galaxies. Two
+models are hydrodynamical, two start with a primordial magnetic field of
+10$^{-6} \mu$G and different sub-solar metallicities, and one starts with a
+saturated field of 10$^{-2} \mu$G. All models include a non-equilibrium,
+time-dependent chemical network that includes the effects of gas shielding from
+the ambient ultraviolet field. Sink particles form directly from the
+gravitational collapse of gas and are treated as star-forming clumps that can
+accrete gas. We vary the ambient uniform far ultraviolet field, and cosmic ray
+ionization rate between 1\% and 10\% of solar values. We find that the magnetic
+field has little impact on the global star formation rate, which is in tension
+with some previously published results. We further find that the initial field
+strength has little impact on the global star formation rate. We show that an
+increase in the mass fractions of both molecular hydrogen and cold gas, along
+with changes in the perpendicular gas velocity dispersion and the magnetic
+field acting in the weak-field model, overcome the expected suppression in star
+formation.",2210.04922v2
+2005-05-23,Strong mean field dynamos require supercritical helicity fluxes,"Several one and two dimensional mean field models are analyzed where the
+effects of current helicity fluxes and boundaries are included within the
+framework of the dynamical quenching model. In contrast to the case with
+periodic boundary conditions, the final saturation energy of the mean field
+decreases inversely proportional to the magnetic Reynolds number. If a
+nondimensional scaling factor in the current helicity flux exceeds a certain
+critical value, the dynamo can operate even without kinetic helicity, i.e. it
+is based only on shear and current helicity fluxes, as first suggested by
+Vishniac & Cho (2001, ApJ 550, 752). Only above this threshold is the current
+helicity flux also able to alleviate catastrophic quenching. The fact that
+certain turbulence simulations have now shown apparently non-resistively
+limited mean field saturation amplitudes may be suggestive of the current
+helicity flux having exceeded this critical value. Even below this critical
+value the field still reaches appreciable strength at the end of the kinematic
+phase, which is in qualitative agreement with dynamos in periodic domains.
+However, for large magnetic Reynolds numbers the field undergoes subsequent
+variations on a resistive time scale when, for long periods, the field can be
+extremely weak.",0505457v2
+2005-07-08,Nonlinear Evolution of the Magnetothermal Instability in Two Dimensions,"In weakly magnetized, dilute plasmas in which thermal conduction along
+magnetic field lines is important, the usual convective stability criterion is
+modified. Instead of depending on entropy gradients, instability occurs for
+small wavenumbers when (dP/dz)(dln T/dz) > 0, which we refer to as the Balbus
+criterion. We refer to the convective instability that results in this regime
+as the magnetothermal instability (MTI). We use numerical MHD simulations which
+include anisotropic electron heat conduction to follow the growth and
+saturation of the MTI in two-dimensional, plane parallel atmospheres that are
+unstable according to the Balbus criterion. The linear growth rates measured in
+the simulations agree with the weak field dispersion relation. We investigate
+the effect of strong fields and isotropic conduction on the linear properties
+and nonlinear regime of the MTI. In the nonlinear regime, the instability
+saturates and convection decays away, when the atmosphere becomes isothermal.
+Sustained convective turbulence can be driven if there is a fixed temperature
+difference between the top and bottom edges of the simulation domain, and if
+isotropic conduction is used to create convectively stable layers that prevent
+the formation of unresolved, thermal boundary layers. The largest component of
+the time-averaged heat flux is due to advective motions. These results have
+implications for a variety of astrophysical systems, such as the temperature
+profile of hot gas in galaxy clusters, and the structure of radiatively
+inefficient accretion flows.",0507212v2
+2005-10-04,Large-scale alpha^2-dynamo in low-mass stars and brown dwarfs,"We develop a model based on 3D mean-field MHD for the generation of large
+scale magnetic fields in fully convective objects like low-mass stars, brown
+dwarfs and possibly gaseous planets. The dynamo process is of alpha^2 type and
+thus differs from the shell-dynamo at work in more massive stars.The alpha^2
+dynamo becomes supercritical for Rossby numbers Ro\la 10. It generates a
+large-scale, non-axisymmetric, steady field that is symmetric with respect to
+the equatorial plane. Saturation of the alpha^2-generated field at the
+equipartition yields strengths of several kGauss, in agreement with
+observations of active M dwarfs, and provides a qualitative explanation for the
+observed activity saturation in late M stars. For brown dwarfs with a
+conductive core, as occurs at the center of the most massive and oldest of
+these objects, we have also studied an alpha^2-Omega dynamo, i.e. the effect of
+differential rotation. In this case the field is predominantly toroidal,
+axisymmetric and oscillatory, like the solar field. The topology of the field
+in the fully convective objects exhibits a high order multipole character that
+differs from the aligned dipole field generated by the alpha-Omega dynamo. The
+strong reduction of the dipolar component due to the field non-axisymmetry
+should considerably reduce the Alfven radius and thus the efficiency of
+magnetic braking, providing an appealing explanation for the decreasing angular
+momentum loss rate observed in low-mass stars and brown dwarfs. This may have
+also implications for cataclysmic variables below the period gap. In spite of
+this large-scale field, the decreasing conductivity in the dominantly neutral
+atmosphere of these objects prevents the current generation necessary to
+support a chromosphere and thus activity. (Abridged)",0510075v1
+2000-08-01,SDW and FISDW transition of (TMTSF)$_2$ClO$_4$ at high magnetic fields,"The magnetic field dependence of the SDW transition in (TMTSF)$_2$ClO$_4$ for
+various anion cooling rates has been measured, with the field up to 27T
+parallel to the lowest conductivity direction $c^{\ast}$. For quenched
+(TMTSF)$_2$ClO$_4$, the SDW transition temperature $T_{\rm {SDW}}$ increases
+from 4.5K in zero field up to 8.4K at 27T. A quadratic behavior is observed
+below 18T, followed by a saturation behavior. These results are consistent with
+the prediction of the mean-field theory. From these behaviors, $T_{\rm {SDW}}$
+is estimated as $T_{\rm {SDW_0}}$=13.5K for the perfect nesting case. This
+indicates that the SDW phase in quenched (TMTSF)$_2$ClO$_4$, where $T_{\rm
+{SDW}}$ is less than 6K, is strongly suppressed by the two-dimensionality of
+the system. In the intermediate cooled state in which the SDW phase does not
+appear in zero field, the transition temperature for the field-induced SDW
+shows a quadratic behavior above 12T and there is no saturation behavior even
+at 27T, in contrast to the FISDW phase in the relaxed state. This behavior can
+probably be attributed to the difference of the dimerized gap due to anion
+ordering.",0008011v1
+2004-11-20,Studies of DC biasing of internal ring on plasma rotation and transport in a toroidal geometry,"We report results from experiments performed to study how a DC bias with
+respect to the plasma potential is affecting the plasma states in the toroidal
+geometry of the Blaamann device in Tromso. In the experiments discussed here, a
+ring with smaller diameter than the limiter was centered inside the bulk of the
+plasma and its bias varied with respect to the plasma potential. In the
+electron saturation current regime of the ring, a significant reduction of the
+fluctuation levels was observed, and a shear in the poloidal velocity occurred
+at the low-field side of the ring. This shear was positioned at the same radial
+position as the maximum of the radial transport when the ring was left floating
+or biased in the ion saturation current regime. For the latter ring biases, the
+poloidal velocities had no shear on the low-field side of the ring. Without the
+velocity shear, the radial transport was similar to previous experiments
+without ring. With the velocity shear, the radial transport was destroyed. This
+plasma state, with very low radial transport and fluctuation levels as well as
+plasma densities around 1017 m-3, is believed to provide a suitable plasma for
+wave propagation studies in a magnetized plasma with curved magnetic field
+lines without end effects.",0411193v1
+2011-07-01,Faraday Rotation Measure due to the Intergalactic Magnetic Field II: the Cosmological Contribution,"We investigate the Faraday rotation measure (RM) due to the intergalactic
+magnetic field (IGMF) through the cosmic web up to cosmological distances,
+using a model IGMF based on turbulence dynamo in the large-scale structure of
+the universe. By stacking the IGMF and gas density data up to redshift $z=5$
+and taking account of the redshift distribution of polarized background radio
+sources against which the RM is measured, we simulate the sky map of the RM.
+The contribution from galaxy clusters is subtracted from the map, based on
+several different criteria of X-ray brightness and temperature. Our findings
+are as follows. The distribution of RM for radio sources of different redshifts
+shows that the root-mean-square (rms) value increases with redshift and
+saturates for $z \ga 1$. The saturated value is RM$_{\rm rms} \approx$ several
+${\rm rad m^{-2}}$. The probability distribution function of $|{\rm RM}|$
+follows the lognormal distribution. The power spectrum has a broad plateau over
+the angular scale of $\sim 1 - 0.1^\circ$ with a peak around $\sim 0.15^\circ$.
+The second-order structure function has a flat profile in the angular
+separation of $\ga 0.2^\circ$. Our results could provide useful insights for
+surveys to explore the IGMF with the Square Kilometer Array (SKA) and upcoming
+SKA pathfinders.",1107.0142v1
+2012-05-16,Constraining the Bulk Lorentz Factor of GRB Outflow in the Magnetic-dominated Jet Model,"Recent observations by the Fermi-LAT showed that there are delayed arrivals
+of GeV photons relative to the onset of MeV photons in some GRBs. In order to
+avoid a large optical depth, the minimal value of the Lorentz factor has been
+estimated to be higher than 1000 in some brightest bursts. In this paper, we
+present a detailed calculation of the time delay between the MeV and GeV
+photons in the framework of the magnetic-dominated jet model. We find that the
+time delay strongly depends on the saturated bulk Lorentz factor of the jet.
+Inspired by this fact, we use this model to calculate the Lorentz factors of
+the four brightest Fermi bursts. The results indicate that the Lorentz factors
+are much smaller than that obtained from the ""single-zone"" scenario. The short
+GRB 090510 has a minimal Lorentz factor 385, while the three long bursts GRB
+080916c, GRB090902b and GRB 090926 have almost the same Lorentz factors, with
+an average value near 260. Another interesting result is that, for long bursts,
+GeV photons are emitted after the bulk Lorentz factor saturates. For the short
+GRB, however, MeV and GeV photons are emitted at the same phase, i.e., either
+at the expansion phase or at the coast phase.",1205.3572v3
+2013-02-05,Implications of mass and energy loss due to coronal mass ejections on magnetically-active stars,"Analysis of a database of solar coronal mass ejections (CMEs) and associated
+flares over the period 1996-2007 finds well-behaved power law relationships
+between the 1-8 AA flare X-ray fluence and CME mass and kinetic energy. We
+extrapolate these relationships to lower and higher flare energies to estimate
+the mass and energy loss due to CMEs from stellar coronae, assuming that the
+observed X-ray emission of the latter is dominated by flares with a frequency
+as a function of energy dn/dE=kE^-alpha. For solar-like stars at saturated
+levels of X-ray activity, the implied losses depend fairly weakly on the
+assumed value of alpha and are very large: M_dot ~ 5x10^-10 M_sun/yr and E_dot
+~ 0.1L_sun. In order to avoid such large energy requirements, either the
+relationships between CME mass and speed and flare energy must flatten for
+X-ray fluence >~ 10^31 erg, or the flare-CME association must drop
+significantly below 1 for more energetic events. If active coronae are
+dominated by flares, then the total coronal energy budget is likely to be up to
+an order of magnitude larger than the canonical 10^-3 L_bol X-ray saturation
+threshold. This raises the question of what is the maximum energy a magnetic
+dynamo can extract from a star? For an energy budget of 1% of L_bol, the CME
+mass loss rate is about 5x10^-11 M_sun/yr.",1302.1136v1
+2014-02-25,Analysis of a drift-diffusion model with velocity saturation for spin-polarized transport in semiconductors,"A system of drift-diffusion equations with electric field under Dirichlet
+boundary conditions is analyzed. The system of strongly coupled parabolic
+equations for particle density and spin density vector describes the
+spin-polarized semi-classical electron transport in ferromagnetic
+semiconductors. The presence of a nonconstant and nonsmooth magnetization
+vector, solution of the Landau-Lifshitz equation, causes the diffusion matrix
+to be dependent from space and time and to have in general poor regularity
+properties, thus making the analysis challenging. To partially overcome the
+analytical difficulties the velocity saturation hypothesis is made, which
+results in a bounded drift velocity. The global-in-time existence and
+uniqueness of weak solutions is shown by means of a semi-discretization in
+time, which yields an elliptic semilinear problem, and a quadratic entropy
+inequality, which allow for the limit of vanishing time step size. The
+convergence of the weak solutions to the steady state, under some restrictions
+on the parameters and data, is shown. Finally the higher regularity of
+solutions for a smooth magnetization in two space dimensions is shown through a
+diagonalization argument, which allows to get rid of the cross diffusion terms
+in the fluid equations, and the iterative application of Gagliardo-Nirenberg
+inequalities and a generalized version of Aubin lemma.",1402.6230v1
+2015-04-09,Impurity coupled to an artificial magnetic field in a Fermi gas in a ring trap,"The dynamics of a single impurity interacting with a many particle background
+is one of the central problems of condensed matter physics. Recent progress in
+ultracold atom experiments makes it possible to control this dynamics by
+coupling an artificial gauge field specifically to the impurity. In this paper,
+we consider a narrow toroidal trap in which a Fermi gas is interacting with a
+single atom. We show that an external magnetic field coupled to the impurity is
+a versatile tool to probe the impurity dynamics. Using Bethe Ansatz (BA) we
+calculate the eigenstates and corresponding energies exactly as a function of
+the flux through the trap. Adiabatic change of flux connects the ground state
+to excited states due to flux quantization. For repulsive interactions, the
+impurity disturbs the Fermi sea by dragging the fermions whose momentum matches
+the flux. This drag transfers momentum from the impurity to the background and
+increases the effective mass. The effective mass saturates to the total mass of
+the system for infinitely repulsive interactions. For attractive interactions,
+the drag again increases the effective mass which quickly saturates to twice
+the mass of a single particle as a polaron of the impurity and one fermion is
+formed. For excited states with momentum comparable to number of particles,
+effective mass shows a resonant behavior. We argue that standard tools in cold
+atom experiments can be used to test these predictions.",1504.02210v2
+2015-06-10,Nonlinear Galactic Dynamos and the Magnetic Pitch Angle,"Pitch angles $p$ of the large-scale magnetic fields $\overline{\bf{\it{B}}}$
+of spiral galaxies have previously been inferred from observations to be
+systematically larger in magnitude than predicted by standard mean-field dynamo
+theory. This discrepancy is more pronounced if dynamo growth has saturated,
+which is reasonable to assume given that such fields are generally inferred to
+be close to energy equipartition with the interstellar turbulence. This 'pitch
+angle problem' is explored using local numerical mean-field dynamo solutions as
+well as asymptotic analytical solutions. It is first shown that solutions in
+the saturated or kinematic regimes depend on only five dynamo parameters, two
+of which are tightly constrained by observations of galaxy rotation curves. The
+remaining 3-dimensional (dimensionless) parameter space can be constrained to
+some extent using theoretical arguments. Predicted values of $|p|$ can be as
+large as $\sim40^\circ$, which is similar to the largest values inferred from
+observations, but only for a small and non-standard region of parameter space.
+We argue, based on independent evidence, that such non-standard parameter
+values are plausible. However, these values are located toward the boundary of
+the allowed parameter space, suggesting that additional physical effects may
+need to be incorporated. We therefore suggest possible directions for extending
+the basic model considered.",1506.03245v2
+2015-09-21,Magnetization of underdoped YBa$_2$Cu$_3$O$_{y}$ above the irreversibility field,"Torque magnetization measurements on YBa$_2$Cu$_3$O$_{y}$ (YBCO) at doping
+$y=6.67$($p=0.12$), in DC fields ($B$) up to 33 T and temperatures down to 4.5
+K, show that weak diamagnetism persists above the extrapolated irreversibility
+field $H_{\rm irr} (T=0) \approx 24$ T. The differential susceptibility
+$dM/dB$, however, is more rapidly suppressed for $B\gtrsim 16$ T than expected
+from the properties of the low field superconducting state, and saturates at a
+low value for fields $B \gtrsim 24$ T. In addition, torque measurements on a
+$p=0.11$ YBCO crystal in pulsed field up to 65 T and temperatures down to 8 K
+show similar behaviour, with no additional features at higher fields. We
+discuss several candidate scenarios to explain these observations: (a)
+superconductivity survives but is heavily suppressed at high field by
+competition with CDW order; (b) static superconductivity disappears near 24 T
+and is followed by a region of fluctuating superconductivity, which causes
+$dM/dB$ to saturate at high field; (c) the stronger 3D ordered CDW that sets in
+above 15 T may suppress the normal state spin susceptibility sufficiently to
+give an apparent diamagnetism of the magnitude observed.",1509.06206v1
+2016-04-14,Magnetotransport of single crystalline YSb,"We report magnetic field dependent transport measurements on a single crystal
+of cubic YSb together with first principles calculations of its electronic
+structure. The transverse magnetoresistance does not saturate up to 9 T and
+attains a value of 75,000 % at 1.8 K. The Hall coefficient is electron-like at
+high temperature, changes sign to hole-like between 110 and 50 K, and again
+becomes electron-like below 50 K. First principles calculations show that YSb
+is a compensated semimetal with a qualitatively similar electronic structure to
+that of isostructural LaSb and LaBi, but with larger Fermi surface volume. The
+measured electron carrier density and Hall mobility calculated at 1.8 K, based
+on a single band approximation, are 6.5$\times10^{20}/$cm$^{3}$ and
+6.2$\times10^{4}$cm$^{2}$/Vs, respectively. These values are comparable with
+those reported for LaBi and LaSb. Like LaBi and LaSb, YSb undergoes a magnetic
+field-induced metal-insulator-like transition below a characteristic
+temperature T$_{m}$, with resistivity saturation below 13 K. Thickness
+dependent electrical resistance measurements show a deviation of the resistance
+behavior from that expected for a normal metal; however, they do not
+unambiguously establish surface conduction as the mechanism for the resistivity
+plateau.",1604.04232v1
+2016-09-02,Influence of Cu deposition potential on the giant magnetoresistance and surface roughness of electrodeposited Ni-Co/Cu multilayers,"It has been shown previously for electrodeposited Co/Cu multilayers that the
+single-bath electrodeposition process can be optimized from an electrochemical
+point of view in order to avoid unwanted Co dissolution and incorporation of Co
+in the non-magnetic layer during the Cu deposition pulse. In the present work,
+electrodeposition of Ni-Co/Cu multilayers has been studied to clarify if the
+same optimization method is appropriate when two magnetic elements are present
+and if this potential results in the largest giant magnetoresistance (GMR) for
+the particular alloy system studied. For this purpose, several Ni-Co/Cu
+multilayers were prepared by varying the deposition potential of the Cu layer.
+The composition analysis of the deposits showed that the Ni:Co ratio exhibits a
+minimum as a function of the Cu deposition potential, which can be explained by
+considering both the dissolution of Co and the mass transport of the reactants.
+Both the saturation GMR value and the intensity of the satellite peaks in the
+X-ray diffractograms were highly correlated with the resulting surface
+roughness of the deposits which was strongly varying with the Cu deposition
+potential. Higher GMR values, lower saturation fields and more perfect
+multilayer structure were observed for sufficiently positive Cu deposition
+potentials only which enabled a partial Co dissolution resulting in a reduced
+surface roughness. The results draw attention to the complexity of the
+optimization procedure of the deposition of multilayers with several alloying
+components.",1609.00597v1
+2017-02-03,The Kinetically Dominated Quasar 3C~418,"The existence of quasars that are kinetically dominated, where the jet
+kinetic luminosity, $Q$, is larger than the total (IR to X-ray) thermal
+luminosity of the accretion flow, $L_{\rm{bol}}$, provides a strong constraint
+on the fundamental physics of relativistic jet formation. Since quasars have
+high values of $L_{\rm{bol}}$ by definition, only $\sim 10$ kinetically
+dominated quasars (with $\overline{Q}/L_{\rm{bol}}>1$) have been found, where
+$\overline{Q}$ is the long term time averaged jet power. We use low frequency
+(151 MHz$-$1.66 GHz) observations of the quasar 3C\,418 to determine
+$\overline{Q}\approx 5.5 \pm 1.3 \times 10^{46} \rm{ergs~s^{-1}}$. Analysis of
+the rest frame ultraviolet spectrum indicates that this equates to $0.57 \pm
+0.28$ times the Eddington luminosity of the central supermassive black hole and
+$\overline{Q}/L_{\rm{bol}} \approx 4.8 \pm 3.1$, making 3C\,418 one of the most
+kinetically dominated quasars found to date. It is shown that this maximal
+$\overline{Q}/L_{\rm{bol}}$ is consistent with models of magnetically arrested
+accretion of jet production in which the jet production reproduces the observed
+trend of a decrement in the extreme ultraviolet continuum as the jet power
+increases. This maximal condition corresponds to an almost complete saturation
+of the inner accretion flow with vertical large scale magnetic flux (maximum
+saturation).",1702.01157v1
+2017-09-15,Reentrant Metallic Behavior in the Weyl Semimetal NbP,"We report the occurrence of reentrant metallic behavior in the Weyl semimetal
+NbP. When the applied magnetic field $H$ is above a critical value $H_c$, a
+reentrance appears as a peak in the temperature dependent resistivity
+$\rho_{xx}(T)$ at $T$ = $T_p$, similar to that observed in graphite where it
+was attributed to local superconductivity. The $T_p(H)$ relationship follows a
+power-law dependence $T_p\sim(H-H_c)^{1/v}$ where $v$ can be derived from the
+temperature dependence of the zero-field resistivity $\rho_0(T) \sim T^v$. From
+concurrent measurements of the transverse $\rho_{xx}(T)$ and Hall
+$\rho_{xy}(T)$ magnetoresistivities, we reveal a clear correlation between the
+rapidly increasing $\rho_{xy}(T)$ and the occurrence of a peak in the
+$\rho_{xx}(T)$ curve. Quantitative analysis indicates that the reentrant
+metallic behavior arises from the competition of the magneto conductivity
+$\sigma_{xx}(T)$ with an additional component
+$\Delta\sigma_{xx}(T)=\kappa_H\sigma_{xx}(T)$ where
+$\kappa_H=[\rho_{xy}(T)/\rho_{xx}(T)]^2$ is the Hall factor. We find that the
+Hall factor ($\kappa_H \approx 0.4$) at peak temperature $T_p$ is nearly
+field-independent, leading to the observed $T_p(H)$ relationship. Furthermore,
+the reentrant metallic behavior in $\rho_{xx}(T)$ also is reflected in the
+behavior of $\rho_{xx}(H)$ that ranges from non-saturating at $T>70$ K to
+saturation at liquid helium temperatures. The latter can be explained with the
+magnetic field dependence of the Hall factor $\kappa_H(H)$. Our studies
+demonstrate that a semiclassical theory can account for the 'anomalies' in the
+magnetotransport phenomena of NbP without invoking an exotic mechanism.",1709.05041v1
+2018-11-13,Probing interacting two-level systems with rare-earth ions,"Two-level systems (TLS) in amorphous materials limit coherence times of a
+number of solid-state quantum devices. Interactions between TLS become
+prominent below 100 mK, but the coupling mechanism and statistical properties
+are still unclear. Here we determine the homogeneous linewidth of ytterbium
+ions (Yb$ ^{3+} $) in silica glass at 10-80 mK by using photon echo techniques
+as a probe of TLS. First, the homogeneous linewidth can be reduced by applying
+a magnetic field of 0.3 T. This effect is due to reduced magnetic interactions
+between adjacent Yb$ ^{3+} $. Secondly, we observe saturation of the linewidth
+below 50 mK to a level of approximately 30 kHz, which is much larger than the
+lifetime-limited value of 0.2 kHz. This saturation behavior is in conflict with
+the coupling to independent TLS. We show that this effect can be explained by
+coherently coupled TLS.",1811.05248v3
+2019-05-06,A van der Waals antiferromagnetic topological insulator with weak interlayer magnetic coupling,"Magnetic topological insulators (TI) provide an important material platform
+to explore quantum phenomena such as quantized anomalous Hall (QAH) effect and
+Majorana modes, etc. Their successful material realization is thus essential
+for our fundamental understanding and potential technical revolutions. By
+realizing a bulk van der Waals material MnBi4Te7 with alternating septuple
+[MnBi2Te4] and quintuple [Bi2Te3] layers, we show that it is ferromagnetic in
+plane but antiferromagnetic along the c axis with an out-of-plane saturation
+field of ~ 0.22 T at 2 K. Our angle-resolved photoemission spectroscopy
+measurements and first-principles calculations further demonstrate that
+MnBi4Te7 is a Z2 antiferromagnetic TI with two types of surface states
+associated with the [MnBi2Te4] or [Bi2Te3] termination, respectively.
+Additionally, its superlattice nature may make various heterostructures of
+[MnBi2Te4] and [Bi2Te3] layers possible by exfoliation. Therefore, the low
+saturation field and the superlattice nature of MnBi4Te7 make it an ideal
+system to investigate rich emergent phenomena.",1905.02154v2
+2020-01-28,Stimulated-emission based model of fast radio bursts,"Fast radio bursts (FRBs) are bright, short-duration radio transients with
+very high brightness temperatures implying highly coherent emission. We suggest
+that the FRBs are caused by the self-focusing of an electron beam interacting
+with an ambient plasma right beyond the light cylinder radius of a neutron
+star. The magnetic field at the light cylinder radius is relatively high which
+can accommodate both young Crab-like systems and old millisecond pulsars
+addressing the diverse environments of FRBs. At the first stage, the intense
+pulsed-beam passing through the background plasma causes instabilities such
+that the trapped particles in local Buneman-type cavitons saturate the local
+field. The beam is then radially self-focused due to the circular electric
+field developed by the two-stream instability which leads to Weibel instability
+in the transverse direction. Finally, the non-linear saturation of the Weibel
+instability results in the self-modulational formation of solitons due to
+plasmoid instability. The resonant solitary waves are the breather-type
+solitons hosting relativistic particles with self-excited oscillations. The
+analytical solutions obtained for non-linear dispersion and solitons suggest
+that, near the current sheets, the relativistic bunches are
+accelerated/amplified by klystron-like structures due to self-excited
+oscillations by the induced local electric field. Boosted coherent radio
+emission propagates through a narrow cone with strong focusing due to radial
+electric field and magnetic pinching. The non-linear evolution of solitons and
+the stimulated emission are associated with the Buneman instability and the
+possibility of the presence of nanosecond shots in FRBs are investigated.",2001.10454v2
+2020-06-30,Suppressed heat conductivity in the intracluster medium: implications for the magneto-thermal instability,"In the outskirts of the intracluster medium (ICM) in galaxy clusters, the
+temperature decreases with radius. Due to the weakly collisional nature of the
+plasma, these regions are susceptible to the magneto-thermal instability (MTI),
+which can sustain turbulence and provide turbulent pressure support in the ICM.
+This instability arises due to heat conduction directed along the magnetic
+field, with a heat conductivity which is normally assumed to be given by the
+Spitzer value. Recent numerical studies of the ion mirror and the electron
+whistler instability using particle-in-cell codes have shown that microscale
+instabilities can lead to a reduced value for the heat conductivity in the ICM.
+This could in turn influence the efficiency with which the MTI drives
+turbulence. In this paper we investigate the influence of reduced heat
+transport on the nonlinear evolution of the MTI. We study plane-parallel,
+initially static atmospheres and employ a subgrid model that mimics the
+influence of the mirror instability on the heat conductivity. We use this
+subgrid model to assess the effect of microscales on the large scale dynamics
+of the ICM. We find that the nonlinear saturation of the MTI is surprisingly
+robust in our simulations. Over a factor of $\sim 10^3$ in the
+thermal-to-magnetic pressure ratio and collisionality we find at most modest
+changes to the saturation of the MTI with respect to reference simulations
+where heat transport is unsuppressed.",2007.00018v2
+2020-08-24,Loop-gas description of the localized-magnon states on the kagome lattice with open boundary conditions,"The high-field regime of the spin-s XXZ antiferromagnet on the kagome lattice
+gives rise to macroscopically degenerate ground states thanks to a completely
+flat lowest single-magnon band. The corresponding excitations can be localized
+on loops in real space and have been coined ""localized magnons"". Thus, the
+description of the many-body ground states amounts to characterizing the
+allowed classical loop configurations and eliminating the quantum mechanical
+linear relations between them. Here, we investigate this loop-gas description
+on finite kagome lattices with open boundary conditions and compare the results
+with exact diagonalization for the spin-1/2 XY model on the same lattice. We
+find that the loop gas provides an exact account of the degenerate ground-state
+manifold while a hard-hexagon description misses contributions from nested loop
+configurations. The densest packing of the loops corresponds to a magnon
+crystal that according to the zero-temperature magnetization curve is a stable
+ground state of the spin-1/2 XY model in a window of magnetic fields of about
+4% of the saturation field just below this saturation field. We also present
+numerical results for the specific heat obtained by the related methods of
+thermal pure quantum (TPQ) states and the finite-temperature Lanczos method
+(FTLM). For a field in the stability range of the magnon crystal, one finds a
+low-temperature maximum of the specific heat that corresponds to a
+finite-temperature phase transition into the magnon crystal at low
+temperatures.",2008.10614v2
+2021-03-04,Nodal superconducting gap in LiFeP revealed by NMR: contrast with LiFeAs,"Identifying the uniqueness of FeP-based superconductors may shed new lights
+on the mechanism of superconductivity in iron-pnictides. Here, we report
+nuclear magnetic resonance(NMR) studies on LiFeP and LiFeAs which have the same
+crystal structure but different pnictogen atoms. The NMR spectrum is sensitive
+to inhomogeneous magnetic fields in the vortex state and can provide the
+information on the superconducting pairing symmetry through the temperature
+dependence of London penetration depth $\lambda_L$. We find that $\lambda_L$
+saturates below $T \sim 0.2$ $T_c$ in LiFeAs, where $T_c$ is the
+superconducting transition temperature, indicating nodeless superconducting
+gaps. Furthermore, by using a two-gaps model, we simulate the temperature
+dependence of $\lambda_L$ and obtain the superconducting gaps of LiFeAs, as
+$\Delta_1 = 1.2$ $k_B T_c$ and $\Delta_2 = 2.8$ $k_B T_c$, in agreement with
+previous result from spin-lattice relaxation. For LiFeP, in contrast, the
+London penetration depth $\lambda_L$ does not show any saturation down to $T
+\sim 0.03 $ $T_c$, indicating nodes in the superconducting energy gap function.
+Finally, we demonstrate that the strong spin fluctuations with diffusive
+characteristics exist in LiFeP, as in some cuprate high temperature
+superconductors.",2103.02991v1
+2021-11-27,Antiferromagnetism and large magnetoresistance in GdBi single crystal,"Single crystal of the binary equi-atomic compound GdBi crystallizing in the
+rock salt type cubic crystal structure with the space group $Fm\bar{3}m$ has
+been grown by flux method. The electrical and magnetic measurements have been
+performed on well oriented single crystals. The antiferromagnetic ordering of
+the Gd moments is confirmed at $T_{\rm N} = 27.5$~K. The magnetization
+measurement performed at $2$~K along the principal crystallographic direction
+[100] did not show any metamagnetic transition and no sign of saturation up to
+$7$~T. Zero field electrical resistivity reveals a sharp drop at $27.5$~K
+suggesting a reduction in the spin disorder scattering due to the
+antiferromagnetic alignment of the Gd moments. The residual resistivity at
+$2$~K is 390~n$\Omega$cm suggesting a good quality of the grown crystal. The
+magneto resistance attains a value of $1.0~\times~10^{4}\%$ with no sign of
+saturation, in a field of $14$~T, at $T = 2$~K. Shubnikov de Hass (SdH)
+oscillations have been observed in the high field range of the
+magnetoresistance with five different frequencies corresponding to the extremal
+areas of the Fermi surface. Analysis of the Hall data revealed a near
+compensation of the charge carriers accounting for the extremely large
+magnetoresistance.",2111.13836v1
+2022-02-03,Exceptionally high saturation magnetisation in Eu-doped magnetite stabilised by spin-orbit interaction,"The significance of the spin-orbit interaction is very well known in
+compounds containing heavier elements such as the rare-earth Eu ion. Here,
+through density functional calculations, we investigated the effect of the
+spin-orbit interaction on the magnetic ground state of Eu doped magnetite
+($\mathrm{Fe_3O_4:Eu_{Fe}}$). By examining all possible spin alignments between
+Eu and magnetite's Fe, we demonstrate that Eu, which is most stable when doped
+at the tetrahedral site, adapts a spin almost opposite the substituted Fe.
+Consequently, because of smaller spin cancellation between the cations on the
+tetrahedral site ($\mathrm{Fe_{Tet}}$ and $\mathrm{Eu_{Tet}}$) and the cations
+on the octahedral sites ($\mathrm{Fe_{Oct}}$), $\mathrm{Fe_3O_4:Eu_{Fe}}$
+exhibits a maximum saturation magnetisation of 9.451 $\mu_B/$f.u. which is
+significantly larger than that of undoped magnetite (calculated to be 3.929
+$\mu_B/$f.u.). We further show that this large magnetisation persists through
+additional electron doping. However, additional hole doping, which may
+unintentionally occur in Fe deficient magnetite, can reduce the magnetisation
+to values smaller than that of the undoped magnetite. The results presented
+here can aid in designing highly efficient magnetically recoverable catalysts
+for which both magnetite and rare earth dopants are common materials.",2202.01453v1
+2022-03-13,The distribution of B-site in the perovskite for a d5-d3 superexchange system studied with Molecular field theory and Monte Carlo simulation,"The B-site disorder in the d5 - d3 system of perovskites has been analyzed
+with molecular field theory and Monte Carlo method. The model is applicable to
+RFe1-pCrpO3 at any p value. When the saturation magnetization MS and phase
+transition temperature TP are known, a model can be built to calculate the
+order or disorder distribution of lattice B-sites. We analyze the case that the
+Fe-Cr superexchange is antiferromagnetic and ferromagnetic coupling
+respectively. The simulation result shows that the theoretical calculation
+formula is suitable for the calculation of different B-site distribution.
+Through the simulation, we find that when the x and y are large, the system
+will appear obvious long-range order. The DM interaction has a certain
+influence on the saturation magnetization. Via calculation, we found that the
+distribution states of Fe and Cr do not always conform to the uniform
+distribution but rather exhibit an effect that reduces the Fe-Fe clustering.
+The establishment of this model offers an explanation for several previously
+contentious issues, e.g., what is the phase transition temperature range of
+double perovskite, and why the different phase transition temperatures with the
+same doping proportion. It provides theoretical guidance for the design of
+functional materials with an arbitrary phase transition temperature.",2203.06599v1
+2022-10-25,Planar Thermal Hall Effects in Kitaev Spin Liquid Candidate Na2Co2TeO6,"We investigate both the longitudinal thermal conductivity ($\kappa_{xx}$) and
+the planar thermal Hall conductivity ($\kappa_{xy}$) in the Kitaev spin liquid
+candidate of Co-based honeycomb antiferromagnet Na$_2$Co$_2$TeO$_6$ in a
+magnetic field ($B$) applied along the $a$ and $a^*$ axes. A finite
+$\kappa_{xy}$ is resolved for both field directions in the antiferromagnetic
+(AFM) phase below the N\'eel temperature of 27 K. The temperature dependence of
+$\kappa_{xy}/T$ shows the emergence of topological bosonic excitations. In
+addition, the field dependence of $\kappa_{xy}$ shows sign reversals at the
+critical fields in the AFM phase, suggesting the changes in the Chern number
+distribution of the topological magnons. Remarkably, a finite $\kappa_{xy}$ is
+observed in $B \parallel a^*$ between the first-order transition field in the
+AFM phase and the saturation field, which is prohibited in a disordered state
+by the two-fold rotation symmetry around the $a^*$ axis of the honeycomb
+lattice, showing the presence of a magnetically ordered state that breaks the
+two-fold rotation symmetry. Our results demonstrate the presence of topological
+magnons in this compound in the whole field range below the saturation field.",2210.13798v1
+2023-07-05,Available energy of trapped electrons in Miller tokamak equilibria,"Available energy (\AE{}), which quantifies the maximum amount of thermal
+energy that may be liberated and converted into instabilities and turbulence,
+has shown to be a useful metric for predicting saturated energy fluxes in
+trapped-electron-mode-driven turbulence. Here, we calculate and investigate the
+\AE{} in the analytical tokamak equilibria introduced by
+\citet{Miller1998NoncircularModel}. The \AE{} of trapped electrons reproduces
+various trends also observed in experiments; negative shear, increasing
+Shafranov shift, vertical elongation, and negative triangularity can all be
+stabilising, as indicated by a reduction in \AE{}, although it is strongly
+dependent on the chosen equilibrium. Comparing \AE{} with saturated energy flux
+estimates from the \textsc{tglf} model, we find fairly good correspondence,
+showcasing that \AE{} can be useful to predict trends. We go on to investigate
+\AE{} and find that negative triangularity is especially beneficial in
+vertically elongated configurations with positive shear or low gradients. We
+furthermore extract a gradient threshold-like quantity from \AE{} and find that
+it behaves similarly to gyrokinetic gradient thresholds: it tends to increase
+linearly with magnetic shear, and negative triangularity leads to an especially
+high threshold. We next optimise the device geometry for minimal \AE{} and find
+that the optimum is strongly dependent on equilibrium parameters, e.g. magnetic
+shear or pressure gradient. Investigating the competing effects of increasing
+the density gradient, the pressure gradient, and decreasing the shear, we find
+regimes that have steep gradients yet low \AE{}, and that such a regime is
+inaccessible in negative-triangularity tokamaks.",2307.02304v2
+2023-10-13,Correcting for T1 bias in Magnetization Transfer Saturation (MTsat) Maps Using Sparse-MP2RAGE,"Purpose: Magnetization transfer saturation (MTsat) mapping is commonly used
+to examine the macromolecular content of brain tissue. This study compared
+variable flip angle (VFA) T1 mapping against compressed sensing (cs)MP2RAGE T1
+mapping for accelerating MTsat imaging. Methods: VFA, MP2RAGE and csMP2RAGE
+were compared against inversion recovery (IR) T1 in a phantom at 3 Tesla. The
+same 1 mm VFA, MP2RAGE and csMP2RAGE protocols were acquired in four healthy
+subjects to compare the resulting T1 and MTsat. Bloch-McConnell simulations
+were used to investigate differences between the phantom and in vivo T1
+results. Finally, ten healthy controls were imaged twice with the csMP2RAGE
+MTsat protocol to quantify repeatability. Results: The MP2RAGE and csMP2RAGE
+protocols were 13.7% and 32.4% faster than the VFA protocol, respectively. All
+approaches provided accurate T1 values (<5% difference) in the phantom, but the
+accuracy of the T1 times was more impacted by differences in T2 for VFA than
+for MP2RAGE. In vivo, VFA generated longer T1 times than MP2RAGE and csMP2RAGE.
+Simulations suggest that the bias in the T1 values between VFA and IR-based
+approaches (MP2RAGE and IR) could be explained by the MT-effects from the
+inversion pulse. In the test-retest experiment, we found that the csMP2RAGE has
+a minimum detectable change of 3% for T1 mapping and 7.9% for MTsat imaging.
+Conclusions: We demonstrated that csMP2RAGE can be used in place of VFA T1
+mapping in an MTsat protocol. Furthermore, a shorter scan time and high
+repeatability can be achieved using the csMP2RAGE sequence.",2310.09102v1
+2022-01-07,The extent of saturation of induced ideals,"We construct a model with a saturated ideal $I$ over
+$\mathcal{P}_{\kappa}\lambda$ and study the extent of saturation of $I$.",2201.02364v1
+2003-03-20,"Bulk viscosity, r-modes, and the early evolution of neutron stars","We discuss the effect of nonlinear bulk viscosity and the associated
+reheating on the evolution of newly born, rapidly rotating neutron stars with
+r-modes destabilized through the Chandrasekhar-Friedman-Schutz (CFS) mechanism.
+Bulk viscosity in these stars is due to the adjustment of the relative
+abundances of different particle species as the density of a fluid element is
+perturbed. It becomes nonlinear when the chemical potential difference
+$\delta\mu$, measuring the chemical imbalance in the fluid element, becomes
+larger than the temperature $T$, which is generally much smaller than the Fermi
+energy. From this scale on, the bulk viscosity increases much faster with
+$\delta\mu$ than predicted by the usual, linear approximation. This provides a
+potential saturation mechanism for stellar oscillation modes at a small to
+moderate amplitude. In addition, bulk viscosity dissipates energy, which can
+lead to neutrino emission, reheating of the star, or both. This is the first
+study to explicitly consider these effects in the evolution of the r-mode
+instability. For stars with little or no hyperon bulk viscosity, these effects
+are not strong enough to prevent the r-modes from growing to amplitudes
+$\alpha\sim 1$ or higher, so other saturation mechanisms will probably set in
+earlier. The reheating effect makes spin-down occur at a higher temperature
+than would otherwise be the case, in this way possibly avoiding complications
+associated with a solid crust or a core superfluid. On the other hand, stars
+with a substantial hyperon bulk viscosity and a moderate magnetic field
+saturate their mode amplitude at a low value, which makes them gravitational
+radiators for hundreds of years, while they lose angular momentum through
+gravitational waves and magnetic braking.",0303454v1
+2011-12-19,X-ray activity and rotation of the young stars in IC 348,"The physical origin of the strong magnetic activity in T Tauri stars and its
+relation to stellar rotation is not yet well understood. We investigate the
+relation between the X-ray activity, rotation, and Rossby number for a sample
+of 82 young stars in the ~3 Myr old cluster IC 348. We use the data of four
+Chandra observations of IC 348 to derive the X-ray luminosities of the young
+stars. The young stars in IC 348 show no correlation between X-ray activity and
+rotation period. Considering the Rossby numbers, nearly all IC 348 stars are in
+the saturated regime of the activity-rotation relation defined by main-sequence
+stars. Searching for possible super-saturation effects, we find a marginal (but
+statistically in-significant) trend that the stars with the smallest Rossby
+numbers show slightly lower X-ray activity levels. We compare the dispersion of
+fractional X-ray luminosities of the stars in the saturated rotation regime in
+IC 348 to that seen in younger and older stellar populations. The scatter seen
+in the ~3 Myr old IC 348 is considerably smaller than for the ~1 Myr old ONC,
+but, at the same time, considerably larger than the dispersion seen in the ~30
+Myr old cluster NGC 2547 and in main-sequence stars. The results of our X-ray
+analysis of IC 348 show that neither the rotation rates nor the
+presence/absence of circumstellar disks are of fundamental importance for
+determining the level of X-ray activity in TTS. Our results suggest that the
+scatter of X-ray activity levels shown by the fast-rotating members of young
+clusters decreases with the age of the stellar population. We interpret this as
+a signature of the changing interior structure of PMS stars and the consequent
+changes in the dynamo mechanisms that are responsible for the magnetic field
+generation.",1112.4290v2
+2023-02-14,Optimization of acquisition parameters for cortical inhomogeneous magnetization transfer (ihMT) imaging using a rapid gradient echo readout,"Purpose: Imaging biomarkers with increased myelin specificity are needed to
+better understand the complex progression of neurological disorders.
+Inhomogeneous magnetization transfer (ihMT) imaging is an emergent technique
+that has a high degree of specificity for myelin content but suffers from low
+signal-to-noise ratio (SNR). This study used simulations to determine optimal
+sequence parameters for ihMT imaging for use in high-resolution cortical
+mapping. Methods: MT-weighted cortical image intensity and ihMT SNR were
+simulated using modified Bloch equations for a range of sequence parameters.
+The acquisition time was limited to 4.5 min/volume. A custom MT-weighted RAGE
+sequence with center-out k-space encoding was used to enhance SNR at 3 Tesla.
+Pulsed MT imaging was studied over a range of saturation parameters and the
+impact of the turbo-factor on effective ihMT was investigated. 1 mm isotropic
+ihMTsat maps were generated in 25 healthy adults using an optimized protocol.
+Results: Greater SNR was observed for larger number of bursts consisting of 6-8
+saturation pulses each, combined with a high readout turbo-factor. However,
+that protocol suffered from a point spread function that was more than twice
+the nominal resolution. For high-resolution cortical imaging, we selected a
+protocol with a higher effective resolution at the cost of a lower SNR. We
+present the first group-average ihMTsat whole-brain map at 1 mm isotropic
+resolution. Conclusion: This study presents the impact of saturation and
+excitation parameters on ihMTsat SNR and resolution. We demonstrate the
+feasibility of high-resolution cortical myelin imaging using ihMTsat in less
+than 20 minutes.",2302.07297v2
+2023-07-30,Non-axisymmetric modes of magnetorotational and possible hydrodynamical instabilities in the upcoming DRESDYN-MRI experiments -- linear and nonlinear dynamics,"The quest for an unambiguous detection of magnetorotational instability (MRI)
+in experiments is still ongoing despite recent promising results. To
+conclusively identify MRI in the laboratory, a large cylindrical Taylor-Couette
+experiment with liquid sodium is under construction within the DRESDYN project.
+In this paper, we investigate the linear and nonlinear dynamics of
+non-axisymmetric MRI in the magnetized Taylor-Couette flow of liquid sodium,
+which is a model flow in this experiment. We show that the achievable highest
+Lundquist $Lu = 10$ and magnetic Reynolds $Rm = 40$ numbers in this experiment
+are large enough for the linear instability of non-axisymmetric modes with
+azimuthal wavenumber $|m|=1$, although the corresponding critical values of
+these numbers are usually higher than those for the axisymmetric mode. The
+structure of the ensuing nonlinear saturated state and its scaling properties
+with respect to Reynolds number $Re$ are analyzed, which are important for the
+DRESDYN-MRI experiment having very high $Re \gtrsim 10^6$. It is shown that for
+$Re \lesssim 4\times 10^4$, the non-axisymmetric MRI modes eventually decay,
+since the modified shear profile of the mean azimuthal velocity due to the
+nonlinear axisymmetric MRI appears to be stable against non-axisymmetric
+instabilities. By contrast, for larger $Re \gtrsim 4\times 10^4$, a rapid
+growth and saturation of the non-axisymmetric modes of nonmagnetic origin
+occurs, which are radially localized near the inner cylinder wall, forming a
+turbulent boundary layer. However, for all the parameters considered, the
+saturation amplitude of these non-axisymmetric modes is always a few orders
+smaller than that of the axisymmetric MRI mode. Therefore, the results of our
+previous axisymmetric study on the scaling properties of nonlinear MRI states
+also hold when non-axisymmetric modes are included.",2307.16295v2
+2007-03-13,Behavior of bulk high-temperature superconductors of finite thickness subjected to crossed magnetic fields,"Crossed magnetic field effects on bulk high-temperature superconductors have
+been studied both experimentally and numerically. The sample geometry
+investigated involves finite-size effects along both (crossed) magnetic field
+directions. The experiments were carried out on bulk melt-processed Y-Ba-Cu-O
+(YBCO) single domains that had been pre-magnetized with the applied field
+parallel to their shortest direction (i.e. the c-axis) and then subjected to
+several cycles of the application of a transverse magnetic field parallel to
+the sample ab plane. The magnetic properties were measured using orthogonal
+pick-up coils, a Hall probe placed against the sample surface and
+Magneto-Optical Imaging (MOI). We show that all principal features of the
+experimental data can be reproduced qualitatively using a two-dimensional
+finite-element numerical model based on an E-J power law and in which the
+current density flows perpendicularly to the plane within which the two
+components of magnetic field are varied. The results of this study suggest that
+the suppression of the magnetic moment under the action of a transverse field
+can be predicted successfully by ignoring the existence of flux-free
+configurations or flux-cutting effects. These investigations show that the
+observed decay in magnetization results from the intricate modification of
+current distribution within the sample cross-section. It is also shown that the
+model does not predict any saturation of the magnetic induction, even after a
+large number (~ 100) of transverse field cycles. These features are shown to be
+consistent with the experimental data.",0703330v2
+2014-02-01,Anisotropic magnetic properties and giant magnetocaloric effect of PrSi single crystal,"Single crystal of PrSi was grown by Czochralski method in a tetra-arc
+furnace. Powder x-ray diffraction of the as grown crystal revealed that PrSi
+crystallizes in FeB$-$type structure with space group $Pnma$ (no. 62). PrSi
+undergoes a ferromagnetic transition at 52 K with [010] direction as the easy
+axis of magnetization. Heat capacity data confirm the bulk nature of the
+transition at 52 K and exhibit a huge anomaly at the transition. A sharp rise
+in the low temperature heat capacity has been observed (below 5 K) which is
+attributed to the $^{141}$Pr nuclear Schottky heat capacity arising from the
+hyperfine field of the Pr moment. The estimated Pr magnetic moment 2.88
+$\mu_{\rm B}$/Pr from the hyperfine splitting is in agreement with the
+saturation magnetization value obtained from the magnetization data measured at
+2 K. From the crystal electric field (CEF) analysis of the magnetic
+susceptibility, magnetization and the heat capacity data it is found that the
+degenerate $J = 4$ Hund's rule derived state of Pr$^{3+}$-ion splits into nine
+singlets with an overall splitting of 284 K, the first excited singlet state
+separated by just 9 K from the ground state. The magnetic ordering in PrGe
+appears to be due to the exchange generated admixture of low lying crystal
+field levels. Magnetocaloric effect (MCE) has been investigated from
+magnetization data along all the three principal crystallographic directions.
+Large magnetic entropy change, $-\Delta S_M = $22.2 J/kg K, and the relative
+cooling power, RCP = $460$ J/kg, characteristic of giant magneto caloric effect
+are achieved near the transition temperature ($T_{\rm C}$ = 52 K) for $H =$~70
+kOe along $[010]$. Furthermore, the PrSi single crystal exhibits a giant MCE
+anisotropy.",1402.0095v1
+2014-10-17,Ferromagnetic resonance in $ε$-Co magnetic composites,"We investigate the electromagnetic properties of assemblies of nanoscale
+$\epsilon$-cobalt crystals with size range between 5 nm to 35 nm, embedded in a
+polystyrene (PS) matrix, at microwave (1-12 GHz) frequencies. We investigate
+the samples by transmission electron microscopy (TEM) imaging, demonstrating
+that the particles aggregate and form chains and clusters. By using a broadband
+coaxial-line method, we extract the magnetic permeability in the frequency
+range from 1 to 12 GHz, and we study the shift of the ferromagnetic resonance
+with respect to an externally applied magnetic field. We find that the
+zero-magnetic field ferromagnetic resonant peak shifts towards higher
+frequencies at finite magnetic fields, and the magnitude of complex
+permeability is reduced. At fields larger than 2.5 kOe the resonant frequency
+changes linearly with the applied magnetic field, demonstrating the transition
+to a state in which the nanoparticles become dynamically decoupled. In this
+regime, the particles inside clusters can be treated as non-interacting, and
+the peak position can be predicted from Kittel's ferromagnetic resonance theory
+for non-interacting uniaxial spherical particles combined with the
+Landau-Lifshitz-Gilbert (LLG) equation. In contrast, at low magnetic fields
+this magnetic order breaks down and the resonant frequency in zero magnetic
+field reaches a saturation value reflecting the interparticle interactions as
+resulting from aggregation. Our results show that the electromagnetic
+properties of these composite materials can be tuned by external magnetic
+fields and by changes in the aggregation structure.",1410.4789v2
+2017-11-15,Laminar and turbulent dynamos in chiral magnetohydrodynamics. II. Simulations,"Using direct numerical simulations (DNS), we study laminar and turbulent
+dynamos in chiral magnetohydrodynamics (MHD) with an extended set of equations
+that accounts for an additional contribution to the electric current due to the
+chiral magnetic effect (CME). This quantum phenomenon originates from an
+asymmetry between left- and right-handed relativistic fermions in the presence
+of a magnetic field and gives rise to a chiral dynamo. We show that the
+magnetic field evolution proceeds in three stages: (1) a small-scale chiral
+dynamo instability; (2) production of chiral magnetically driven turbulence and
+excitation of a large-scale dynamo instability due to a new chiral effect
+(alpha_mu effect); and (3) saturation of magnetic helicity and magnetic field
+growth controlled by a conservation law for the total chirality. The
+$\alpha_\mu$ effect becomes dominant at large fluid and magnetic Reynolds
+numbers and is not related to kinetic helicity. The growth rate of the
+large-scale magnetic field and its characteristic scale measured in the
+numerical simulations agree well with theoretical predictions based on
+mean-field theory. The previously discussed two-stage chiral magnetic scenario
+did not include stage (2) during which the characteristic scale of magnetic
+field variations can increase by many orders of magnitude. Based on the
+findings from numerical simulations, the relevance of the CME and the chiral
+effects revealed in the relativistic plasma of the early universe and of
+proto-neutron stars are discussed.",1711.09733v3
+2018-11-14,Intensity contrast of solar plage as a function of magnetic flux at high spatial resolution,"Magnetic elements have an intensity contrast that depends on the type of
+region they are located in (e.g. quiet Sun, or active region plage). Observed
+values also depend on the spatial resolution of the data. Here we investigate
+the contrast-magnetic field dependence in active region plage observed near
+disk center with Sunrise during its second flight in 2013. The wavelengths
+under study range from the visible at 525\,nm to the near ultraviolet (NUV) at
+300\,nm and 397\,nm. We use quasi-simultaneous spectropolarimetric and
+photometric data from the Imaging Magnetograph eXperiment (IMaX) and the
+Sunrise Filter Imager (SuFI), respectively. We find that in all wavelength
+bands, the contrast exhibits a qualitatively similar dependence on the
+line-of-sight magnetic field, $B_{\rm LOS}$, as found in the quiet Sun, with
+the exception of the continuum at 525\,nm. There, the contrast of plage
+magnetic elements peaks for intermediate values of $B_{\rm LOS}$ and decreases
+at higher field strengths. By comparison, the contrast of magnetic elements in
+the quiet Sun saturates at its maximum value at large $B_{\rm LOS}$. We find
+that the explanation of the turnover in contrast in terms of the effect of
+finite spatial resolution of the data is incorrect with the evidence provided
+by the high-spatial resolution Sunrise data, as the plage magnetic elements are
+larger than the quiet Sun magnetic elements and are well-resolved. The turnover
+comes from the fact that the core pixels of these larger magnetic elements are
+darker than the quiet Sun. We find that plages reach lower contrast than the
+quiet Sun at disk center at wavelength bands formed deep in the photosphere,
+such as the visible continuum and the 300\,nm band. This difference decreases
+with formation height and disappears in the Ca\,{\sc ii} H core, in agreement
+with empirical models of magnetic element atmospheres.",1811.05759v1
+2020-09-02,New highly-anisotropic Rh-based Heusler compound for magnetic recording,"The development of high-density magnetic recording media is limited by the
+superparamagnetism in very small ferromagnetic crystals. Hard magnetic
+materials with strong perpendicular anisotropy offer stability and high
+recording density. To overcome the difficulty of writing media with a large
+coercivity, heat assisted magnetic recording (HAMR) has been developed, rapidly
+heating the media to the Curie temperature Tc before writing, followed by rapid
+cooling. Requirements are a suitable Tc, coupled with anisotropic thermal
+conductivity and hard magnetic properties. Here we introduce Rh2CoSb as a new
+hard magnet with potential for thin film magnetic recording. A
+magnetocrystalline anisotropy of 3.6 MJm-3 is combined with a saturation
+magnetization of {\mu}0Ms = 0.52 T at 2 K (2.2 MJm-3 and 0.44 T at
+room-temperature). The magnetic hardness parameter of 3.7 at room temperature
+is the highest observed for any rare-earth free hard magnet. The anisotropy is
+related to an unquenched orbital moment of 0.42 {\mu}B on Co, which is
+hybridized with neighbouring Rh atoms with a large spin-orbit interaction.
+Moreover, the pronounced temperature-dependence of the anisotropy that follows
+from its Tc of 450 K, together with a high thermal conductivity of 20 Wm-1K-1,
+makes Rh2CoSb a candidate for development for heat assisted writing with a
+recording density in excess of 10 Tb/in2.",2009.01034v1
+2023-04-06,Microscopic characterization of the magnetic properties of the itinerant antiferromagnet La2Ni7 by 139La NMR/NQR measurements,"139La nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR)
+measurements have been performed to investigate the magnetic properties of the
+itinerant magnet La2Ni7 which shows a series of antiferromagnetic (AFM) phase
+transitions at $T_{N1}$=61 K, $T_{N2}$=56 K, and $T_{N3}$=42 K under zero
+magnetic field. Two distinct La NMR signals were observed due to the two
+crystallographically inequivalent La sites in La2Ni7 (La1 and La2 in the La2Ni4
+and the LaNi5 sub-units of the La2Ni7 unit cell, respectively). From the 139La
+NQR spectrum in the AFM state below $T_{N3}$, the AFM state was revealed to be
+a commensurate state where Ni ordered moments align along the crystalline c
+axis. Owing to the two different La sites, we were able to estimate the average
+values of the Ni ordered moments ($\sim$0.09-0.10 $\mu_{B}$/Ni and
+$\sim$0.17$\mu_{B}$/Ni around La1 and La2, respectively) from 139La NMR
+spectrum measurements in the AFM state below $T_{N3}$, suggesting a non-uniform
+distribution of the Ni-ordered moments in the AFM state. In contrast, a more
+uniform distribution of the Ni-ordered moments in the saturated paramagnetic
+state induced by the application of high magnetic fields is observed. The
+temperature dependence of the sublattice magnetization measured by the internal
+field at the La2 site in the AFM state was reproduced by a local moment model
+better than the self-consistent renormalization (SCR) theory for weak itinerant
+antiferromagnets. Given the small Ni-ordered moments in the magnetically
+ordered state, our results suggest that La2Ni7 has characteristics of both
+itinerant and localized natures in its magnetism. With this in mind, it is
+noteworthy that the temperature dependence of nuclear spin-relaxation rates in
+the paramagnetic state above $T_{N1}$ measured at zero magnetic field can be
+explained qualitatively by both the SCR theory and the local-moment model.",2304.03157v2
+2023-12-07,On the role of numerical diffusivity in MHD simulations of global accretion disc dynamos,"Observations, mainly of outbursts in dwarf novae, imply that the anomalous
+viscosity in highly ionized accretion discs is magnetic in origin, and requires
+that the plasma $\beta \sim 1$. Until now most simulations of the magnetic
+dynamo in accretion discs have used a local approximation (known as the
+shearing box). While these simulations demonstrate the possibility of a
+self-sustaining dynamo, the magnetic activity generated in these models
+saturates at $\beta \gg 1$. This long-standing discrepancy has previously been
+attributed to the local approximation itself. There have been recent attempts
+at simulating magnetic activity in global accretion discs with parameters
+relevant to the dwarf novae. These too find values of $\beta \gg 1$. We
+speculate that the tension between these models and the observations may be
+caused by numerical magnetic diffusivity. As a pedagogical example, we present
+exact time-dependent solutions for the evolution of weak magnetic fields in an
+incompressible fluid subject to linear shear and magnetic diffusivity. We find
+that the maximum factor by which the initial magnetic energy can be increased
+depends on the magnetic Reynolds number as ${\mathcal R}_{\rm m}^{2/3}$. We
+estimate that current global numerical simulations of dwarf nova discs have
+numerical magnetic Reynolds numbers around 6 orders of magnitude less than the
+physical value found in dwarf nova discs of ${\mathcal R}_{\rm m} \sim
+10^{10}$. We suggest that, given the current limitations on computing power,
+expecting to be able to compute realistic dynamo action in observable accretion
+discs using numerical MHD is, for the time being, a step too far.",2312.04400v1
+1998-05-11,Turbulence and angular momentum transport in a global accretion disk simulation,"The global development of magnetohydrodynamic turbulence in an accretion disk
+is studied within a simplified disk model that omits vertical stratification.
+Starting with a weak vertical seed field, a saturated state is obtained after a
+few tens of orbits in which the energy in the predominantly toroidal magnetic
+field is still subthermal. The efficiency of angular momentum transport,
+parameterized by the Shakura-Sunyaev alpha parameter, is of the order of 0.1.
+The dominant contribution to alpha comes from magnetic stresses, which are
+enhanced by the presence of weak net vertical fields. The power spectra of the
+magnetic fields are flat or decline only slowly towards the largest scales
+accessible in the calculation, suggesting that the viscosity arising from MHD
+turbulence may not be a locally determined quantity. I discuss how these
+results compare with observationally inferred values of alpha, and possible
+implications for models of jet formation.",9805133v1
+1999-01-27,Non-linear dynamics of Kelvin-Helmholtz unstable magnetized jets: three-dimensional effects,"A numerical study of the Kelvin-Helmholtz instability in compressible
+magnetohydrodynamics is presented. The three-dimensional simulations consider
+shear flow in a cylindrical jet configuration, embedded in a uniform magnetic
+field directed along the jet axis. The growth of linear perturbations at
+specified poloidal and axial mode numbers demonstrate intricate non-linear
+coupling effects. The physical mechanims leading to induced secondary
+Kelvin-Helmholtz instabilities at higher mode numbers are identified. The
+initially weak magnetic field becomes locally dominant in the non-linear
+dynamics before and during saturation. Thereby, it controls the jet deformation
+and eventual breakup. The results are obtained using the Versatile Advection
+Code [G. Toth, Astrophys. Lett. Comm. 34, 245 (1996)], a software package
+designed to solve general systems of conservation laws. An independent
+calculation of the same Kelvin-Helmholtz unstable jet configuration using a
+three-dimensional pseudo-spectral code gives important insights into the
+coupling and excitation events of the various linear mode numbers.",9901383v1
+1999-09-03,Effect of Expansion and Magnetic Field Configuration on Mass Entrainment of Jets,"We investigate the growth of jet plus entrained mass in simulations of
+supermagnetosonic cylindrical and expanding jets. The entrained mass spatially
+grows in three stages: from an initially slow spatial rate to a faster rate and
+finally at a flatter rate. These stages roughly coincide with the similar rates
+of expansion in simulated radio intensity maps, and also appear related to the
+growth of the Kelvin-Helmholtz instability through linear, nonlinear, and
+saturated regimes. In the supermagnetosonic cylindrical jets, we found that a
+jet with an embedded primarily toroidal magnetic field is more stable than a
+jet with a primarily axial magnetic field. Also, pressure-matched expanding
+jets are more stable and entrain less mass than cylindrical jets with
+equivalent inlet conditions.",9909077v1
+2000-12-11,Sheared helical turbulence and the helicity constraint in large-scale dynamos,"The effect of shear on the growth of large scale magnetic fields in helical
+turbulence is investigated. The resulting large-scale magnetic field is also
+helical and continues to evolve, after saturation of the small scale field, on
+a slow resistive time scale. This is a consequence of magnetic helicity
+conservation. Because of shear, the time scale needed to reach an
+equipartition-strength large scale field is shortened proportionally to the
+ratio of the resulting toroidal to poloidal large scale fields.",0012240v1
+2003-04-12,Magnetic Helicity Evolution During the Solar Activity Cycle: Observations and Dynamo Theory,"We study a simple model for the solar dynamo in the framework of the Parker
+migratory dynamo, with a nonlinear dynamo saturation mechanism based on
+magnetic helicity conservation arguments. We find a parameter range in which
+the model demonstrates a cyclic behaviour with properties similar to that of
+Parker dynamo with the simplest form of algebraic alpha-quenching. We compare
+the nonlinear current helicity evolution in this model with data for the
+current helicity evolution obtained during 10 years of observations at the
+Huairou Solar Station of China. On one hand, our simulated data demonstrate
+behaviour comparable with the observed phenomenology, provided that a suitable
+set of governing dynamo parameters is chosen. On the other hand, the
+observational data are shown to be rich enough to reject some other sets of
+governing parameters. We conclude that, in spite of the very preliminary state
+of the observations and the crude nature of the model, the idea of using
+observational data to constrain our ideas concerning magnetic field generation
+in the framework of the solar dynamo appears promising.",0304232v1
+2003-10-09,A Magnetic Betelgeuse? Numerical Simulations of Non-linear Dynamo Action,"Betelgeuse is an example of a cool super-giant displaying brightness
+fluctuations and irregular surface structures. Simulations by Freytag et al.
+(2002) of the convective envelope of the star have shown that the fluctuations
+in the star's luminosity may be caused by giant cell convection. A related
+question regarding the nature of Betelgeuse and supergiants in general is
+whether these stars may be magnetically active. If so, that may in turn also
+contribute to their variability. By performing detailed numerical simulations,
+I find that both linear kinematic and non-linear dynamo action are possible and
+that the non-linear magnetic field saturates at a value somewhat below
+equipartition: in the linear regime there are two modes of dynamo action.",0310279v1
+2006-03-17,Local Kelvin-Helmholtz instability and synchrotron modulation in Pulsar Wind Nebulae,"We present here a series of numerical simulations of the development of
+Kelvin-Helmholtz instability in a relativistically hot plasma. The physical
+parameters in the unperturbed state are chosen to be representative of local
+conditions encountered in Pulsar Wind Nebulae (PWNe), with a main magnetic
+field perpendicular to a mildly relativistic shear layers. By using a numerical
+code for Relativistic MHD, we investigate the effect of an additional magnetic
+field component aligned with the shear velocity, and we follow the evolution of
+the instability to the saturation and turbulent regimes. Based on the resulting
+flow structure, we then compute synchrotron maps in order to evaluate the
+signature of Kelvin-Helmholtz instability on the emission and we investigate
+how the time scale and the amplitude of the synchrotron modulations depend on
+shear velocity and magnetic field. Finally we compare our results to the
+observed variable features in the Crab Nebula. We show that the
+Kelvin-Helmholtz instability cannot account for the wisps variability, but it
+might be responsible for the time dependent filamentary structure observed in
+the main torus.",0603481v1
+1995-10-13,Plateau of the Magnetization Curve of the S=1/2 Ferromagnetic-Ferromagnetic-Antiferromagnetic Spin Chain,"I analytically study the plateau of the magnetization curve at $M/M_{\rm S} =
+1/3$ (where $M_{\rm S}$ is the saturation magnetization) of the one-dimensional
+$S=1/2$ trimerized Heisenberg spin system with ferromagnetic ($J_{\rm
+F}$)-ferromagnetic ($J_{\rm F}$)-antiferromagnetic ($J_{\rm A}$) interactions
+at $T=0$. I use the bosonization technique for the fermion representation of
+the spin Hamiltonian through the Jordan-Wigner transformation. The plateau
+appears when $\gamma \equiv J_{\rm F}/J_{\rm A} \allowbreak < \gamma_{\rm C}$,
+and vanishes when $\gamma > \gamma_{\rm C}$, where the critical value
+$\gamma_{\rm C}$ is estimated as $\gamma_{\rm C} = 5 \sim 6$. The behavior of
+the width of the plateau near $\gamma_{\rm C}$ is of the Kosterlitz-Thouless
+type. The present theory well explains the numerical result by Hida.",9510070v1
+1995-10-18,Metamagnetism and Fermi Surface in the Anderson Lattice Model,"We investigate magnetization as functions of external magnetic field $H$ in
+the $U$-infinite Anderson lattice model within the leading order approximation
+in the $1/N$-expansion. At $T=0$, at $H=H_M$ where the Zeeman energy is equal
+to a certain characteristic energy in the system, the magnetization curve has a
+kink and the differential susceptibility $dM/dH$ shows a jump. At finite
+temperature, $dM/dH$ shows a peak around $H_M$. Its maximum value increases
+with decreasing $T$ and saturates to a finite value at $T\to 0$. When $H<H_M$,
+the $f$ and the conduction electrons form the renormalized bands with a large
+Fermi surface determined by the Luttinger sum rule. On the other hand, when
+$H>H_M$, the bands reform themselves significantly free from the Luttinger sum
+rule, eventually leading to a small Fermi surface at $H \gg H_M$. The results
+are consistent with the metamagnetic properties observed in the heavy fermion
+CeRu$_2$Si$_2$.",9510095v1
+1996-09-20,High Temperature Thermopower in La_{2/3}Ca_{1/3}MnO_3 Films: Evidence for Polaronic Transport,"Thermoelectric power, electrical resistivity and magnetization experiments,
+performed in the paramagnetic phase of La_{2/3}Ca_{1/3}MnO_3, provide evidence
+for polaron-dominated conduction in CMR materials. At high temperatures, a
+large, nearly field-independent difference between the activation energies for
+resistivity (rho) and thermopower (S), a characteristic of Holstein Polarons,
+is observed, and ln(rho) ceases to scale with the magnetization. On approaching
+T_c, both energies become field-dependent, indicating that the polarons are
+magnetically polarized. Below T_c, the thermopower follows a law S(H) prop.
+1/rho (H) as in non saturated ferromagnetic metals.",9609212v1
+1997-05-30,Ferromagnetism in the Hubbard model: Influence of the lattice structure,"By use of the spectral density approach the influence of the lattice
+structure on the possibility of ferromagnetism in the single band Hubbard model
+is investigated. The d=\infty hypercubic lattice does not show magnetic phase
+transitions of second order irrespective of the strength of the Coulomb
+coupling. However, first order transitions to finite magnetic moments, not
+visible as singularities of the paramagnetic susceptibility, may appear in the
+very strong coupling regime. In d=3 second order transitions are found but only
+for very strong couplings, where the non-locality of the electronic self-energy
+acts in favour of the spontaneous magnetic moment. The influence of the
+non-local part of the self-energy is particularly strong for lattices with
+small coordination number. The non-bipartite fcc lattice exhibits saturated
+ferromagnetism for all band occupations $1\le n\le 2$ while for less than half
+filled bands ($0\le n\le 1$) the system remains in any case paramagnetic, and
+that for d=3 as well as d=\infty. The Curie temperature runs through a maximum
+at about $n=1.4$ and vanishes for $n\to 1$ and $n\to 2$.",9705305v1
+1998-05-19,On the Theory of Magnets with Competing Double Exchange and Superexchange Interactions,"In the CMR materials, ferromagnetic double exchange (DE) presumably coexists
+with a direct nearest-neighbour antiferromagnetic interaction. We construct a
+single-site mean field theory that explicitly takes into account the different
+nature of carrier-mediated ferromagnetism vs. Heisenberg-like superexchange. We
+find, in contrast to previous results in the literature, that the competition
+between these two exchange interactions leads to ferro- or antiferromagnetic
+order with incomplete saturation of the magnetization (or sublattice
+magnetization), rather than spin canting. The associated experimental
+implications are discussed.",9805238v3
+1998-10-19,Coupled Ladders in a Magnetic Field,"We investigate the phase transitions in two-leg ladders systems in the
+incommensurate phase, for which the gap is destroyed by a magnetic field
+($h_{c1}< h$) and the ladder is not yet totally saturated ($h < h_{c2}$). We
+compute quantitatively the correlation functions as a function of the magnetic
+field for an isolated strong coupling ladder $J_\perp \gg J_\parallel$ and use
+it to study the phase transition occuring in a three dimensional array of
+antiferromagnetically coupled ladders. The three dimensional ordering is in the
+universality class of Bose condensation of hard core bosons. We compute the
+critical temperature $T_c(h)$ as well as various physical quantities such as
+the NMR relaxations rate. $T_c$ has an unusual camel-like shape with a local
+minimum at $h=(h_{c1}+h_{c2})/2$ and behaves as $T_c \sim (h-h_{c1})^{2/3}$ for
+$h\sim h_{c1}$. We discuss the experimental consequences for compounds such as
+Cu_2(C_5H_{12}N_2)_2Cl_4",9810219v2
+1999-03-10,Response to Parallel Magnetic Field of a Dilute 2D Electron System across the Metal-Insulator Transition,"The response to a parallel magnetic field of the very dilute insulating
+two-dimensional system of electrons in silicon MOSFET's is dramatic and similar
+to that found on the conducting side of the metal-insulator transition: there
+is a large initial increase in resistivity with increasing field, followed by
+saturation to a value that is approximately constant above a characteristic
+magnetic field of about one Tesla. This is unexpected behavior in an insulator
+that exhibits Efros-Shklovskii variable-range hopping in zero field, and
+appears to be a general feature of very dilute electron systems.",9903179v3
+1999-06-15,Separation of quadrupolar and magnetic contributions to spin-lattice relaxation in the case of a single isotope,"We present a NMR pulse double-irradiation method which allows one to separate
+magnetic from quadrupolar contributions in the spin-lattice relaxation. The
+pulse sequence fully saturates one transition while another is observed. In the
+presence of a Delta m = 2 quadrupolar contribution, the intensity of the
+observed line is altered compared to a standard spin-echo experiment. We
+calculated analytically this intensity change for spins I=1, 3/2, 5/2, thus
+providing a quantitative analysis of the experimental results. Since the pulse
+sequence we used takes care of the absorbed radio-frequency power, no problems
+due to heating arise. The method is especially suited when only one NMR
+sensitive isotope is available. Different cross-checks were performed to prove
+the reliability of the obtained results. The applicability of this method is
+demonstrated by a study of the plane oxygen 17O (I = 5/2) in the
+high-temperature superconductor YBa_2Cu_4O_8: the 17O spin-lattice relaxation
+rate consists of magnetic as well as quadrupolar contributions.",9906216v1
+1999-07-30,Quantum Phase Transition of S=1/2 Trimerized XXZ Spin Chain in Magnetic Field,"We study the magnetization plateau at a third of the saturation magnetization
+of the S=1/2 trimerized XXZ spin chain at T=0. The appearance of the plateau
+depends on the values of the XXZ anisotropy and the magnitude of the
+trimerization. This plateauful-plateauless transition is a quantum phase
+transition of the Berezinskii-Kosterlitz-Thouless type, which is difficult to
+precisely detect from the numerical data. To determine the phase boundary line
+of this transition precisely, we use the level crossing of low-lying
+excitations obtained from the numerical diagonalization. We also discuss the
+S=1/2 ferromagnetic-ferromagnetic-antiferromagnetic chain.",9907481v1
+1999-12-10,Weak-localization corrections to the conductivity of double quantum wells,"The weak-localization contribution \delta\sigma(B) to the conductivity of a
+tunnel-coupled double-layer electron system is evaluated and its behavior in
+weak magnetic fields B perpendicular or parallel to the layers is examined. In
+a perpendicular field B, \delta \sigma(B) increases and remains dependent on
+tunneling as long as the magnetic field is smaller than \hbar/e D \tau_t, where
+D is the in-plane diffusion coefficient and \tau_t the interlayer tunneling
+time. If \tau_t is smaller than the inelastic scattering time, a parallel
+magnetic field also leads to a considerable increase of the concuctivity
+starting with a B**2 law and saturating at fields higher than \hbar/e Z (D
+\tau_t)**(1/2), where Z is the interlayer distance. In the limit of coherent
+tunneling, when \tau_t is comparable to elastic scattering time, \delta
+\sigma(B) differs from that of a single-layer system due to ensuing
+modifications of the diffusion coefficient. A possibility to probe the
+weak-localization effect in double-layer systems by the dependence of the
+conductivity on the gate-controlled level splitting is discussed.",9912169v1
+2000-04-20,Dynamical response of a pinned two-dimensional Wigner crystal,"We re-examine a long-standing problem of a finite-frequency conductivity of a
+weakly pinned two-dimensional classical Wigner crystal. In this system an
+inhomogeneously broadened absorption line (pinning mode) centered at disorder
+and magnetic field dependent frequency $\omega_p$ is known to appear. We show
+that the relative linewidth $\Delta \omega_p / \omega_p$ of the pinning mode is
+of the order of one in weak magnetic fields, exhibits a power-law decrease in
+intermediate fields, and eventually saturates at a small value in strong
+magnetic fields. The linewidth narrowing is due to a peculiar mechanism of
+mixing between the stiffer longitudinal and the softer transverse components of
+the collective excitations. The width of the high-field resonance proves to be
+related to the density of states in the low-frequency tail of the zero-field
+phonon spectrum. We find a qualitative agreement with recent experiments and
+point out differences from the previous theoretical work on the subject.",0004343v1
+2000-07-31,Carrier-induced ferromagnetism in p-Zn1-xMnxTe,"We present a systematic study of the ferromagnetic transition induced by the
+holes in nitrogen doped Zn1-xMnxTe epitaxial layers, with particular emphasis
+on the values of the Curie-Weiss temperature as a function of the carrier and
+spin concentrations. The data are obtained from thorough analyses of the
+results of magnetization, magnetoresistance and spin-dependent Hall effect
+measurements. The experimental findings compare favorably, without adjustable
+parameters, with the prediction of the Rudermann-Kittel-Kasuya-Yosida (RKKY)
+model or its continuous-medium limit, that is, the Zener model, provided that
+the presence of the competing antiferromagnetic spin-spin superexchange
+interaction is taken into account, and the complex structure of the valence
+band is properly incorporated into the calculation of the spin susceptibility
+of the hole liquid. In general terms, the findings demonstrate how the
+interplay between the ferromagnetic RKKY interaction, carrier localization, and
+intrinsic antiferromagnetic superexchange affects the ordering temperature and
+the saturation value of magnetization in magnetically and electrostatically
+disordered systems.",0007502v1
+2000-11-02,The Magnetic Spin Ladder (C_{5}H_{12}N)_{2}CuBr_{4}: High Field Magnetization and Scaling Near Quantum Criticality,"The magnetization, $M(H \leq 30$ T, 0.7 K $\leq T \leq 300$ K), from single
+crystals and powder samples of (C$_{5}$H$_{12}$N)$_{2}$CuBr$_{4}$ has been used
+to identify this system as an $S=1/2$ Heisenberg two-leg ladder in the strong
+coupling limit, $J_{\perp} = 13.3$ K and $J_{\parallel} = 3.8$ K, with $H_{c1}
+= 6.6$ T and $H_{c2} = 14.6$ T. An inflection point in $M(H, T = 0.7$ K) at
+half-saturation, $M_{s}/2$, is described by an effective \emph{XXZ} chain. The
+data exhibit universal scaling behavior in the vicinity of $H_{c1}$ and
+$H_{c2}$, indicating the system is near a quantum critical point.",0011052v2
+2000-12-09,"Staggered magnetization, critical behavior and weak ferromagnetic propert ies of LaMnO$_3$ by muon spin rotation","We present a study of a microtwinned single crystal of LaMnO$_3$ by means of
+implanted muons. Two muon stopping sites are identified from the symmetry of
+the internal field in the ordered phase. The temperature dependence of these
+fields yields the behavior of the staggered magnetization from which a static
+critical exponent ($\beta=0.36(2)$) is extracted and discussed. The muon
+spin-spin relaxation rate shows a critical slowing down (contrary to
+preliminary findings) with a critical exponent $n=0.7(1)$, witnessing the Ising
+nature of the dynamic fluctuations. The muon precession frequencies vs. applied
+magnetic field reveal the saturation of the weak ferromagnetic domain structure
+originated by the Dzialoshinski-Moriya antisymmetric exchange.",0012158v2
+2000-12-15,Alternating-Spin Ladders in a Magnetic Field: New Magnetization Plateaux,"We study numerically the formation of magnetization plateaux with the Lanczos
+method in 2-leg ladders with mixed spins of magnitudes $(S_1,S_2)=(1,1/2)$
+located at alternating positions along the ladder and with dimerization
+$\gamma$. For interchain coupling $J'>0$ and $\gamma=0$, we find normalized
+plateaux at $m=1/3$ starting at zero field and $m=1$ (saturation), while when
+$\gamma \ne 0$ is columnar, another extra plateau at $m=2/3$ shows up. For
+$J'<0$, when $\gamma<\gamma_c(J')$ we find no plateau while for
+$\gamma>\gamma_c(J')$ we find four plateaux at $m=0,1/3,2/3,1$. We also apply
+several approximate analytical methods (Spin Wave Theory, Low-Energy Effective
+Hamiltonians and Bosonization) to understand these findings and to conjeture
+the behaviour of ferrimagnetic ladders with a bigger number of legs.",0012278v1
+2001-01-12,Superfluid-spiral state of quantum ferrimagnets in magnetic field,"We study the phase diagram of one-dimensional quantum ferrimagnets by using a
+numerical exact diagonalization of a finite size system along with a
+field-theoretical non-linear $\sigma$ model of the quantum ferrimagnets at zero
+temperature and its effective description in the presence of the external
+magnetic field in terms of the quantum XY-model. The low- and the high-field
+phases correspond respectively to the classical N\'eel and the fully polarized
+ferromagnetic states where in the intermediate magnetic field ($h_{c1} < h <
+h_{c2}$), it is an XXZ+h model with easy plane anisotropy, which possess the
+spiral (superfluid) states that carry the dissipationless spin-supercurrent. We
+derive the critical exponents, and then will study the stability of the XY
+spiral state against these spin-supercurrents and the hard axis fluctuations.
+We will show a first order phase transition from the easy plane spiral state to
+a saturated ferromagnetic state occurs at $h=h_{c2}$ if the spin-supercurrent
+reaches to its critical value.",0101194v1
+2001-04-02,Antiferromagnetic vortex state in a high-temperature superconductor,"There is strong evidence that magnetic interactions play a crucial role in
+the mechanism driving high-temperature superconductivity in cuprate
+superconductors. To investigate this further we have done neutron scattering
+experiments on the simplest high-temperature superconductor La(2-x)Sr(x)CuO(4)
+(LSCO) in an applied magnetic field. Below the superconducting transition
+temperature (Tc), the field penetrates the material via an array of normal
+state inclusions or vortices while phase coherent superconductivity
+characterized by zero resistance is suppressed to the lower field-dependent
+irreversibility temperature. The measurements described here were performed on
+underdoped LSCO (x=0.10), which develops static incommensurate order below Tc
+in zero field. Our results show that application of a magnetic field enhances
+this response without changing the onset temperature. For H=5T the
+field-induced signal saturates to three times the zero-field signal and phase
+coherent superconductivity is established within the antiferromagnetic phase.",0104026v1
+2001-08-29,Macroscopic magnetization jumps due to independent magnons in frustrated quantum spin lattices,"For a class of frustrated spin lattices including the kagome lattice we
+construct exact eigenstates consisting of several independent, localized
+one-magnon states and argue that they are ground states for high magnetic
+fields. If the maximal number of local magnons scales with the number of spins
+in the system, which is the case for the kagome lattice, the effect persists in
+the thermodynamic limit and gives rise to a macroscopic jump in the
+zero-temperature magnetization curve just below the saturation field. The
+effect decreases with increasing spin quantum number and vanishes in the
+classical limit. Thus it is a true macroscopic quantum effect.",0108498v2
+2002-02-13,Field Suppression of the Density-of-States: A Mechanism for Large Linear Magnetoresistance,"Hall, resistivity, magnetization, and thermoelectric power measurements were
+performed on single crystals of the highly anisotropic layered metal LaSb2. A
+100-fold linear magnetoresistance (MR) was observed in fields up to 45 T, with
+no indication of saturation. We show that the MR is associated with a
+magnetic-field-dependent holelike carrier density, n(H) \propto 1/H. The effect
+is orbital, depending upon the component of the magnetic field normal to the
+layers. At low temperature, a field of 9 T reduces the carrier density by more
+than an order of magnitude.",0202220v1
+2002-08-12,"Fe/V and Fe/Co (001) superlattices: growth, anisotropy, magnetisation and magnetoresistance","Some physical properties of bcc Fe/V and Fe/Co (001) superlattices are
+reviewed. The dependence of the magnetic anisotropy on the in-plane strain
+introduced by the lattice mismatch between Fe and V is measured and compared to
+a theoretical derivation. The dependence of the magnetic anisotropy (and
+saturation magnetisation) on the layer thickness ratio Fe/Co is measured and a
+value for the anisotropy of bcc Co is derived from extrapolation. The
+interlayer exchange coupling of Fe/V superlattices is studied as a function of
+the layer thickness V (constant Fe thickness) and layer thickness of Fe
+(constant V thickness). A region of antiferromagnetic coupling and GMR is found
+for V thicknesses 12-14 monolayers. However, surprisingly, a 'cutoff' of the
+antiferromagnetic coupling and GMR is found when the iron layer thickness
+exceeds about 10 monolayers.",0208229v1
+2002-11-28,Magneto-superconductivity of 100-atm O2-annealed RuSr2Gd1.5Ce0.5Cu2O10,"Studied 100-atm O2-annealed RuSr2Gd1.5Ce0.5Cu2O10 (Ru-1222) compound
+crystallized in a tetragonal I4/mmm space group crystal structure.
+Thermo-gravemetric (TG) analysis of the compound showed the release of oxygen
+and breaking to metallic constituents in two distinct steps at around 350 and
+500 0C. The DC magnetization data (M vs. T) revealed magnetic transition at 100
+K followed by superconducting transition at 40 K. Low field M vs. H hysteresis
+loop showed a lower critical field (Hc1) value of around 25 Oe. Ferromagnetic
+component is evidenced at 5, 10, 20 and 40 K. Near saturation field of above 5
+Tesla is observed at 5 K. Zero-field returning moment (Mr) and zero-moment
+coercive field (Hc) values at 5 K are 0.35mB and 250 Oe. The resistance vs.
+temperature (R vs. T) behaviour of the sample confirmed superconductivity at
+around 43 K. Superconductivity transition (Tc) is broadened under magnetic
+field with strong granularity like steps.",0211644v1
+2003-02-25,Two-dimensional Induced Ferromagnetism,"Magnetic properties of materials confined to nanometer length scales are
+providing important information regarding low dimensional physics. Using
+gadolinium based Langmuir-Blodgett films, we demonstrate that two-dimensional
+ferromagnetic order can be induced by applying magnetic field along the
+in-plane (perpendicular to growth) direction. Field dependent exchange coupling
+is evident in the in-plane magnetization data that exhibit absence of
+hysteresis loop and show reduction in field required to obtain saturation in
+measured moment with decreasing temperature.",0302516v2
+2003-07-28,Low temperature spin fluctuations in geometrically frustrated Yb3Ga5O12,"In the garnet structure compound Yb3Ga5O12, the Yb3+ ions (ground state
+effective spin S' = 1/2) are situated on two interpenetrating corner sharing
+triangular sublattices such that frustrated magnetic interactions are possible.
+Previous specific heat measurements evidenced the development of short range
+magnetic correlations below 0.5K and a lambda-transition at 54mK (Filippi et
+al. J. Phys. C: Solid State Physics 13 (1980) 1277). From 170-Yb M""ossbauer
+spectroscopy measurements down to 36mK, we find there is no static magnetic
+order at temperatures below that of the lambda-transition. Below 0.3K, the
+fluctuation frequency of the short range correlated Yb3+ moments progressively
+slows down and as the temperature tends to 0, the frequency tends to a
+quasi-saturated value of 3 x 10^9 s^-1. We also examined the Yb3+ paramagnetic
+relaxation rates up to 300K using 172-Yb perturbed angular correlation
+measurements: they evidence phonon driven processes.",0307676v1
+2004-01-31,Bond Operator Mean Field Approach to the Magnetization Plateaux in Quantum Antiferromagnets -- Application to the S=1/2 Coupled Dimerized Zigzag Heisenberg Chains,"The magnetization plateaux in two dimensionally coupled S=1/2 dimerized
+zigzag Heisenberg chains are investigated by means of the bond operator mean
+field approximation. In the absence of the interchain coupling, this model is
+known to have a plateau at half of the saturation magnetization accompanied by
+the spontanuous translational symmetry breakdown. The parameter regime in which
+the plateau appears is reproduced well within the present approximation. In the
+presence of the interchain coupling, this plateau is shown to be suppressed.
+This result is also supported by the numerical diagonalization calculation.",0402008v2
+2004-06-04,Absence of magnetic order for the spin-half Heisenberg antiferromagnet on the star lattice,"We study the ground-state properties of the spin-half Heisenberg
+antiferromagnet on the two-dimensional star lattice by spin-wave theory, exact
+diagonalization and a variational mean-field approach. We find evidence that
+the star lattice is (besides the \kagome lattice) a second candidate among the
+11 uniform Archimedean lattices where quantum fluctuations in combination with
+frustration lead to a quantum paramagnetic ground state. Although the classical
+ground state of the Heisenberg antiferromagnet on the star exhibits a huge
+non-trivial degeneracy like on the \kagome lattice, its quantum ground state is
+most likely dimerized with a gap to all excitations. Finally, we find several
+candidates for plateaux in the magnetization curve as well as a macroscopic
+magnetization jump to saturation due to independent localized magnon states.",0406103v2
+2004-06-24,"Magneto-transport studies on (Pr1/3Sm2/3)2/3A1/3MnO3 (A = Ca, Sr and Ba) compounds","Magnetic and transport properties of (Pr1/3Sm2/3)2/3A1/3MnO3 (A = Ca, Sr and
+Ba) compounds, prepared by the citrate gel route, have been investigated. These
+compounds are found to crystallize in the orthorhombic structure. Charge
+ordering transport behavior is indicated only in Ca-substituted compound. The
+Sr- and Ba-substituted compounds show metal-insulator transition and
+semiconducting-like behavior, respectively. The magnetoresistance is highest in
+the Ba substituted compound. All the three samples show irreversibility in
+magnetization as a function of temperature in zero-field cooled (ZFC) and field
+cooled (FC) plots. The non-saturating magnetization, even at 5K and 4 Tesla
+field, are observed in Ca as well Ba-substituted compounds.",0406599v1
+2005-01-28,Quantum vs. Classical Magnetization Plateaus of S=1/2 Frustrated Heisenberg Chains,"The competition between quantum and classical magnetization plateaus of S=1/2
+frustrated Heisenberg chains with modified exchange couplings is investigated.
+The conventional S=1/2 frustrated Heisenberg chains is known to exhibit a
+3-fold degenerate udu-type classical plateau at 1/3 of the saturation
+magnetization accompanied by the spontaneous Z_3 translational symmetry
+breakdown. The stability of this plateau phase against period 3 exchange
+modulation which favors the 00u-type quantum plateau state (00= singlet dimer)
+is studied by bosonization, renormalization group and numerical diagonalization
+methods. The ground state phase diagram and the spin configuration in each
+phase are numerically determined. The translationally invariant Valence Bond
+Solid-type model with 4-spin and third neighbor interactions, which has the
+exact 00u-type quantum plateau state, is also presented. The phase transition
+to the classical udu-type ground state is also observed by varying the strength
+of 4-spin and third neighbor interactions. The relation between these two types
+of models with quantum plateau states is discussed.",0501697v2
+2005-07-08,Field-induced non-Fermi-liquid resistivity of stoichiometric YbAgGe single crystals,"We have investigated hexagonal YbAgGe down to 70 mK by measuring the
+magnetic-field and temperature dependence of the resistivity rho of single
+crystals in fields up to 14 T. Our results extend the H-T phase diagram to the
+lowest temperatures for H applied in the basal plane and along the c-axis. In
+particular, critical fields for the suppression of several magnetic phases are
+determined. The temperature dependence of rho(T) is unusual: whereas at low H,
+rho(T) reveals a temperature exponent n>=2, we find 1<=n<1.5 and strong
+enhancement of the temperature dependence of rho(T) close to and beyond the
+highest critical field for each field direction. For H applied in the basal
+plane, at high fields a conventional T^2 dependence of rho(T) is reached above
+10 T accompanied by an approach to saturation of a strong drop in the residual
+resistivity. YbAgGe appears to be one of few Yb-based stoichiometric systems,
+where quantum-critical behaviour may be induced by a magnetic field.",0507211v2
+2005-09-05,Unified description of bulk and interface-enhanced spin pumping,"The dynamics of non-equilibrium spin accumulation generated in metals or
+semiconductors by rf magnetic field pumping is treated within a diffusive
+picture. The dc spin accumulation produced in a uniform system by a rotating
+applied magnetic field or by a precessing magnetization of a weak ferromagnet
+is in general given by a (small) fraction of hbar omega, where omega is the
+rotation or precession frequency. With the addition of a neighboring,
+field-free region and allowing for the diffusion of spins, the spin
+accumulation is dramatically enhanced at the interface, saturating at the
+universal value hbar omega in the limit of long spin relaxation time. This
+effect can be maximized when the system dimensions are of the order of sqrt(2pi
+D omega), where D is the diffusion constant. We compare our results to the
+interface spin pumping theory of A. Brataas et al. [Phys. Rev. B 66, 060404(R)
+(2002)].",0509100v1
+2005-09-10,Theory of Magnetodynamics Induced by Spin Torque in Perpendicularly Magnetized Thin Films,"A nonlinear model of spin wave excitation using a point contact in a thin
+ferromagnetic film is introduced. Large-amplitude magnetic solitary waves are
+computed, which help explain recent spin-torque experiments. Numerical
+simulations of the fully nonlinear model predict excitation frequencies in
+excess of 0.2 THz for contact diameters smaller than 6 nm. Simulations also
+predict a saturation and red shift of the frequency at currents large enough to
+invert the magnetization under the point contact. The theory is approximated by
+a cubic complex Ginzburg-Landau type equation. The mode's nonlinear frequency
+shift is found by use of perturbation techniques, whose results agree with
+those of direct numerical simulations.",0509265v1
+2005-09-20,Magnetism and superconductivity of strongly correlated electrons on the triangular lattice,"We investigate the phase diagram of the \tj Model on a triangular lattice
+using a Variational Monte-Carlo approach. We use an extended set of Gutzwiller
+projected fermionic trial wave-functions allowing for simultaneous magnetic and
+superconducting order parameters. We obtain energies at zero doping for the
+spin-1/2 Heisenberg model in very good agreement with the best estimates. Upon
+electron doping (with a hopping integral $t<0$) this phase is surprisingly
+stable variationally up to $n\approx 1.4$, while the $d_{x^{2}-y^{2}}+i d_{xy}$
+order parameter is rather weak and disappears at $n\approx 1.1$. For hole
+doping however the coplanar magnetic state is almost immediately destroyed and
+$d_{x^{2}-y^{2}}+i d_{xy}$ superconductivity survives down to $n\approx 0.8$.
+For lower $n$, between 0.2 and 0.8, we find saturated ferromagnetism. Moreover,
+there is evidence for a narrow spin density wave phase around $n\approx 0.8$.
+Commensurate flux phases were also considered, but these turned out {\em not}
+to be competitive at finite doping.",0509520v2
+2006-03-10,A microspectroscopic study of the electronic homogeneity of ordered and disordered Sr2FeMoO6,"Besides a drastic reduction in saturation magnetization of disordered
+Sr2FeMoO6 compared to highly ordered samples, magnetizations as a function of
+the temperature for different disordered samples may also show qualitatively
+different behaviors. We investigate the origin of such diversity by performing
+spatially resolved photoemission spectroscopy on various disordered samples.
+Our results establish that extensive electronic inhomogeneity, arising most
+probably from an underlying chemical inhomogeneity in disordered samples is
+responsible for the observed magnetic inhomogeneity. It is further pointed out
+that these inhomogeneities are connected with composition fluctuations of the
+type Sr2Fe1+xMo1-xO6 with Fe-rich (x>0) and Mo-rich (x<0) regions.",0603291v1
+2006-04-15,Anisotropic Dependence of Giant Magneto-Impedance of Amorphous Ferromagnetic Ribbon on Biasing Field,"The magneto-impedance (MI) in amorphous ribbon of nominal composition
+Fe73.5Nb3Cu1Si13.5B9 has been measured at 1MHz and at room temperature for
+different configurations of exciting a.c and biasing d.c. fields. A large drop
+in both resistance and reactance is observed as a function of d.c magnetic
+field. When the d.c and a.c fields are parallel but normal to the axis of
+ribbon, smaller magnetic field is needed to reduce the impedance to its small
+saturated value compared to the situation when fields are along the axis of
+ribbon. Larger d.c. field is required to lower the impedance when the d.c field
+acts perpendicular to the plane of the ribbon. Such anisotropy in
+magneto-impedance is related to the anisotropic response of the magnetization
+of ribbon. The large change of impedance is attributed to large variation of
+a.c permeability on the direction and magnitude of the dc biasing field.",0604382v2
+2006-09-23,Epitaxial growth and the magnetic properties of orthorhombic YTiO3 thin films,"High-quality YTiO3 thin films were grown on LaAlO3 (110) substrates at low
+oxygen pressures (<10-8 Torr) using pulsed laser deposition. The in-plane
+asymmetric atomic arrangements at the substrate surface allowed us to grow
+epitaxial YTiO3 thin films, which have an orthorhombic crystal structure with
+quite different a- and b-axes lattice constants. The YTiO3 film exhibited a
+clear ferromagnetic transition at 30 K with a saturation magnetization of about
+0.7 uB/Ti. The magnetic easy axis was found to be along the [1-10] direction of
+the substrate, which differs from the single crystal easy axis direction, i.e.,
+[001].",0609602v1
+2006-10-04,Cu-NMR study on the disordered quantum spin magnet with the Bose-glass ground state,"Cu-NMR study has been performed on the disordered spin-gap system
+Tl1-xKxCuCl3 In the high-field H > HC=\Delta/\mu_B, where \Delta is the
+spin-gap, the hyperfine field becomes extremely inhomogeneous at low
+temperatures due to the field-induced magnetic order, indicating that the
+ordered spin state must be different from the pure TlCuCl3. In the low field H
+< HC, a saturating behavior in the longitudinal nuclear spin relaxation rate
+1/T1 was observed at low temperatures, indicating existence of the magnetic
+ground state proposed to be Bose-glass phase by Fisher.",0610101v1
+2006-10-11,Engineering Exchange Coupling in Double Elliptic Quantum Dots,"Coupled elliptic quantum dots with different aspect ratios containing up to
+two electrons are studied using a model confinement potential in the presence
+of magnetic fields. Single and two particle Schroedinger equations are solved
+using numerical exact diagonolization to obtain the exchange energy and
+chemical potentials. As the ratio between the confinement strengths in
+directions perpendicular and parallel to the coupling direction of the double
+dots increases, the exchange energy at zero magnetic field increases, while the
+magnetic field of the singlet-triplet transition decreases. By investigating
+the charge stability diagram, we find that as inter-dot detuning increases, the
+absolute value of the exchange energy increases superlinearly followed by
+saturation. This behavior is attributed to the electron density differences
+between the singlet and triplet states in the assymetric quantum dot systems.",0610281v1
+2006-10-11,Proton-induced magnetic order in carbon: SQUID measurements,"In this work we have studied systematically the changes in the magnetic
+behavior of highly oriented pyrolytic graphite (HOPG) samples after proton
+irradiation in the MeV energy range. Superconducting quantum interferometer
+device (SQUID) results obtained from samples with thousands of localized spots
+of micrometer size as well on samples irradiated with a broad beam confirm
+previously reported results. Both, the para- and ferromagnetic contributions
+depend strongly on the irradiation details. The results indicate that the
+magnetic moment at saturation of spots of micrometer size is of the order of
+$10^{-10}$ emu.",0610293v1
+2007-01-31,Nuclear Magnetic Resonance Study of Ultrananocrystalline Diamonds,"We report on a nuclear magnetic resonance (NMR) study of ultrananocrystalline
+diamond (UNCD) materials produced by detonation technique. Analysis of the 13C
+and 1H NMR spectra, spin-spin and spin-lattice relaxation times in purified
+UNCD samples is presented. Our measurements show that UNCD particles consist of
+a diamond core that is partially covered by a sp2-carbon fullerene-like shell.
+The uncovered part of outer diamond surface comprises a number of hydrocarbon
+groups that saturate the dangling bonds. Our findings are discussed along with
+recent calculations of the UNCD structure. Significant increase in the
+spin-lattice relaxation rate (in comparison with that of natural diamond), as
+well as stretched exponential character of the magnetization recovery, are
+attributed to the interaction of nuclear spins with paramagnetic centers which
+are likely fabrication-driven dangling bonds with unpaired electrons. We show
+that these centers are located mainly at the interface between the diamond core
+and shell.",0701771v1
+1992-08-31,Electric-Magnetic Duality and Supersymmetry in Stringy Black Holes,"We present a generalization of the $U(1)^{2}$ charged dilaton black holes
+family whose main feature is that both $U(1)$ fields have electric and magnetic
+charges, the axion field still being trivial. We show the supersymmetry of
+these solutions in the extreme case, in which the corresponding generalization
+of the Bogomolnyi bound is saturated and a naked singularity is on the verge of
+being visible to external observers. Then we study the action of a subset of
+the $SL(2,R)$ group of electric-magnetic duality rotations that generates a
+non-trivial axion field on those solutions. This group of transformations is an
+exact symmetry of the $N=4$ $d=4$ ungauged supergravity equations of motion. It
+has been argued recently that it could be an exact symmetry of the full
+effective string theory. The generalization of the Bogomolnyi bound is
+invariant under the full $SL(2,R)$ and the solutions explicitly rotated are
+shown to be supersymmetric if the originals are. We conjecture that any
+$SL(2,R)$ transformation will preserve supersymmetry.",9208078v1
+2000-07-11,Type-I strings on magnetised orbifolds and brane transmutation,"In the presence of internal magnetic fields, a D9 brane can acquire a D5 (or
+anti-D5) R-R charge, and can therefore contribute to the corresponding tadpole.
+In the resulting vacua, supersymmetry is generically broken and tachyonic
+instabilities are present. However, suitable choices for the magnetic fields,
+corresponding to self-dual configurations in the internal space, can yield new
+chiral supersymmetric vacua with gauge groups of reduced rank, where the
+magnetic energy saturates, partly or fully, the negative tension of the O5+
+planes. These models contain Green-Schwarz couplings to untwisted R-R forms not
+present in conventional orientifolds.",0007090v2
+2000-09-15,Exact time-correlation functions of quantum Ising chain in a kicking transversal magnetic field,"Spectral analysis of the {\em adjoint} propagator in a suitable Hilbert space
+(and Lie algebra) of quantum observables in Heisenberg picture is discussed as
+an alternative approach to characterize infinite temperature dynamics of
+non-linear quantum many-body systems or quantum fields, and to provide a bridge
+between ergodic properties of such systems and the results of classical ergodic
+theory. We begin by reviewing some recent analytic and numerical results along
+this lines. In some cases the Heisenberg dynamics inside the subalgebra of the
+relevant quantum observables can be mapped explicitly into the (conceptually
+much simpler) Schr\"" odinger dynamics of a single one-(or few)-dimensional
+quantum particle. The main body of the paper is concerned with an application
+of the proposed method in order to work out explicitly the general spectral
+measures and the time correlation functions in {\em a quantum Ising spin 1/2
+chain in a periodically kicking transversal magnetic field}, including the
+results for the simpler autonomous case of a static magnetic field in the
+appropriate limit. The main result, being a consequence of a purely continuous
+non-trivial part of the spectrum, is that the general time-correlation
+functions decay to their saturation values as $t^{-3/2}$.",0009031v1
+2003-06-28,Self-similar turbulent dynamo,"The amplification of magnetic fields in a highly conducting fluid is studied
+numerically. During growth, the magnetic field is spatially intermittent: it
+does not uniformly fill the volume, but is concentrated in long thin folded
+structures. Contrary to a commonly held view, intermittency of the folded field
+does not increase indefinitely throughout the growth stage if diffusion is
+present. Instead, as we show, the probability-density function (PDF) of the
+field strength becomes self-similar. The normalized moments increase with
+magnetic Prandtl number in a powerlike fashion. We argue that the
+self-similarity is to be expected with a finite flow scale and system size. In
+the nonlinear saturated state, intermittency is reduced and the PDF is
+exponential. Parallels are noted with self-similar behavior recently observed
+for passive-scalar mixing and for map dynamos.",0306059v3
+2007-04-29,Critical state analysis of orthogonal flux interactions in pinned superconductors,"We show that, based on the critical state model for flux-line pinning in hard
+superconductors, one can assess the magnetic moment relaxation induced by the
+oscillations of a perpendicular magnetic field. Our theory follows a recent
+proposal of using phenomenological 2D modeling for the description of crossed
+field dynamics in high-T$_c$ superconductors [{\tt arXiv:cond-mat/0703330}].
+  Stationary regimes with either saturation to metastable configurations, or
+complete decay to the thermodynamic equilibrium are obtained. The transition
+between both types of response is related to the disappearance of a flux free
+core within the sample. As a common feature, a step-like dependence in the time
+relaxation is predicted for both cases. The theory may be applied to long bars
+of arbitrary and non homogeneous cross section, under in-plane magnetic field
+processes.",0704.3830v1
+2007-05-24,Nonequilibrium Dynamics of Anisotropic Large Spins in the Kondo Regime: Time-Dependent Numerical Renormalization Group Analysis,"We investigate the time-dependent Kondo effect in a single-molecule magnet
+(SMM) strongly coupled to metallic electrodes. Describing the SMM by a Kondo
+model with large spin S > 1/2, we analyze the underscreening of the local
+moment and the effect of anisotropy terms on the relaxation dynamics of the
+magnetization. Underscreening by single-channel Kondo processes leads to a
+logarithmically slow relaxation, while finite uniaxial anisotropy causes a
+saturation of the SMM's magnetization. Additional transverse anisotropy terms
+induce quantum spin tunneling and a pseudospin-1/2 Kondo effect sensitive to
+the spin parity.",0705.3654v2
+2007-06-28,Coherent Magnetization Precession in GaMnAs induced by Ultrafast Optical Excitation,"We use femtosecond optical pulses to induce, control and monitor
+magnetization precession in ferromagnetic Ga0.965Mn0.035As. At temperatures
+below ~40 K we observe coherent oscillations of the local Mn spins, triggered
+by an ultrafast photoinduced reorientation of the in-plane easy axis. The
+amplitude saturation of the oscillations above a certain pump intensity
+indicates that the easy axis remains unchanged above ~TC/2. We find that the
+observed magnetization precession damping (Gilbert damping) is strongly
+dependent on pump laser intensity, but largely independent on ambient
+temperature. We provide a physical interpretation of the observed light-induced
+collective Mn-spin relaxation and precession.",0706.4270v2
+2007-07-21,Ferromagnetism as a universal feature of nanoparticles of the otherwise nonmagnetic oxides,"Room-temperature ferromagnetism has been observed in the nanoparticles (7 -
+30 nm dia) of nonmagnetic oxides such as CeO2, Al2O3, ZnO, In2O3 and SnO2. The
+saturated magnetic moments in CeO_2 and Al_2O_3 nanoparticles are comparable to
+those observed in transition metal doped wide band semiconducting oxides. The
+other oxide nanoparticles show somewhat lower values of magnetization but with
+a clear hysteretic behavior. Conversely, the bulk samples obtained by sintering
+the nanoparticles at high temperatures in air or oxygen became diamagnetic. As
+there were no magnetic impurities present, we assume that the origin of
+ferromagnetism may be due to the exchange interactions between localized
+electron spin moments resulting from oxygen vacancies at the surfaces of
+nanoparticles. We suggest that ferromagnetism may be a universal characteristic
+of nanopartilces of metal oxides",0707.3183v1
+2007-08-08,"Magnetic properties of Gd_xY_{1-x}Fe_2Zn_{20}: dilute, large, $\textbf {S}$ moments in a nearly ferromagnetic Fermi liquid","Single crystals of the dilute, rare earth bearing, pseudo-ternary series,
+Gd_xY_{1-x}Fe_2Zn_{20} were grown out of Zn-rich solution. Measurements of
+magnetization, resistivity and heat capacity on Gd_xY_{1-x}Fe_2Zn_{20} samples
+reveal ferromagnetic order of Gd^{3+} local moments across virtually the whole
+series ($x \geq 0.02$). The magnetic properties of this series, including the
+ferromagnetic ordering, the reduced saturated moments at base temperature, the
+deviation of the susceptibilities from Curie-Weiss law and the anomalies in the
+resistivity, are understood within the frame work of dilute, $\textbf {S}$
+moments (Gd^{3+}) embedded in a nearly ferromagnetic Fermi liquid
+(YFe_2Zn_{20}). The s-d model is employed to further explain the variation of
+$T_{\mathrm{C}}$ with x as well as the temperature dependences of of the
+susceptibilities.",0708.1170v1
+2007-08-15,"Effects of selective dilution on the magnetic properties of La_{0.7}Sr_{0.3}Mn_{1-x}M'_xO_3 (M' = Al, Ti)","The magnetic lattice of mixed-valence Mn ions in
+La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ is selectively diluted by partial substitution of
+Al or Ti for Mn. The ferromagnetic transition temperature $T_\mathrm{c}$ and
+the saturation magnetization $M_\mathrm{s}$ both decrease with substitution. By
+presenting the data in terms of selective dilution, $T_\mathrm{c}$ in the
+low-doping region is found to follow the relation
+$T_\mathrm{c}=T_\mathrm{c0}(1-n_\mathrm{p})$, where $T_\mathrm{c0}$ refers to
+the undiluted system and $n_\mathrm{p}$ is the dilution concentration defined
+as $n_\mathrm{p}=x/0.7$ or $n_\mathrm{p}=x/0.3$ for $M^\prime=$ Al or Ti,
+respectively. The scaling behavior of $T_\mathrm{c}(n_\mathrm{p})$ can be
+analyzed in the framework of the molecular-field theory and still valid when Mn
+is substituted by both Al and Ti. The results are discussed with respect to the
+contributions from ferromagnetic double exchange and other possible
+antiferromagnetic superexchange interactions coexisting in the material.",0708.2025v1
+2007-08-21,Magnetic and transport properties of the one-dimensional ferromagnetic Kondo lattice model with an impurity,"We have studied the ferromagnetic Kondo lattice model (FKLM) with an Anderson
+impurity on finite chains with numerical techniques. We are particularly
+interested in the metallic ferromagnetic phase of the FKLM. This model could
+describe either a quantum dot coupled to one-dimensional ferromagnetic leads
+made with manganites or a substitutional transition metal impurity in a MnO
+chain. We determined the region in parameter space where the impurity is empty,
+half-filled or doubly-occupied and hence where it is magnetic or nonmagnetic.
+The most important result is that we found, for a wide range of impurity
+parameters and electron densities where the impurity is magnetic, a singlet
+phase located between two saturated ferromagnetic phases which correspond
+approximately to the empty and double-occupied impurity states. Transport
+properties behave in general as expected as a function of the impurity
+occupancy and they provide a test for a recently developed numerical approach
+to compute the conductance. The results obtained could be in principle
+reproduced experimentally in already existent related nanoscopic devices or in
+impurity doped MnO nanotubes.",0708.2826v2
+2007-08-24,Influence of the L21 ordering degree on the magnetic properties in Co2MnSi Heusler films,"We report on the influence of the improved L21 ordering degree on the
+magnetic properties of Co2MnSi Heusler films. Different fractions of the L21
+phase are obtained by different post-growth annealing temperatures ranging from
+350 degC to 500 degC. Room temperature magneto-optical Kerr effect measurements
+reveal an increase of the coercivity at an intermediate annealing temperature
+of 425 degC, which is a fingerprint of an increased number of pinning centers
+at this temperature. Furthermore, Brillouin light scattering studies show that
+the improvement of the L21 order in the Co2MnSi films is correlated with a
+decrease of the saturation magnetization by about 9%. The exchange stiffness
+constant of Co2MnSi, however, increases by about 8% when the L21 order is
+improved. Moreover, we observe a drop of the cubic anisotropy constant K1 by a
+factor of 10 for an increasing amount of the L21 phase.",0708.3303v1
+2007-11-13,Magnetism of one-dimensional Wigner lattices and its impact on charge order,"The magnetic phase diagram of the quarter-filled generalized Wigner lattice
+with nearest- and next-nearest-neighbor hopping t_1 and t_2 is explored. We
+find a region at negative t_2 with fully saturated ferromagnetic ground states
+that we attribute to kinetic exchange. Such interaction disfavors
+antiferromagnetism at t_2 <0 and stems from virtual excitations across the
+charge gap of the Wigner lattice, which is much smaller than the Mott-Hubbard
+gap proportional to U. Remarkably, we find a strong dependence of the charge
+structure factor on magnetism even in the limit U to infinity, in contrast to
+the expectation that charge ordering in the Wigner lattice regime should be
+well described by spinless fermions. Our results, obtained using the
+density-matrix renormalization group and exact diagonalization, can be
+transparently explained by means of an effective low-energy Hamiltonian.",0711.1990v2
+2008-01-08,Tunneling anisotropic magnetoresistance in multilayer-(Co/Pt)/AlOx/Pt structures,"We report observations of tunneling anisotropic magnetoresitance (TAMR) in
+vertical tunnel devices with a ferromagnetic multilayer-(Co/Pt) electrode and a
+non-magnetic Pt counter-electrode separated by an AlOx barrier. In stacks with
+the ferromagnetic electrode terminated by a Co film the TAMR magnitude
+saturates at 0.15% beyond which it shows only weak dependence on the magnetic
+field strength, bias voltage, and temperature. For ferromagnetic electrodes
+terminated by two monolayers of Pt we observe order(s) of magnitude enhancement
+of the TAMR and a strong dependence on field, temperature and bias. Discussion
+of experiments is based on relativistic ab initio calculations of magnetization
+orientation dependent densities of states of Co and Co/Pt model systems.",0801.1192v1
+2008-03-04,Expanding color flux tubes and instabilities,"We present an analytic study of the physics of the glasma which is a strong
+classical gluon field created at early stage of high-energy heavy-ion
+collisions. Our analysis is based on the picture that the glasma just after the
+collision is made of color electric and magnetic flux tubes extending in the
+longitudinal direction with their diameters of the order of 1/Q_s (Q_s is the
+saturation scale of the colliding nuclei). We find that both the electric and
+magnetic flux tubes expand outwards and the field strength inside the flux tube
+decays rapidly in time. Next we investigate whether there exist instabilities
+against small rapidity-dependent perturbations for a fixed color configuration.
+We find that the magnetic background field exhibits an instability induced by
+the fluctuations in the lowest Landau level, and it grows in the time scale of
+1/Q_s. For the electric background field we find no apparent instability while
+the possible relation to the Schwinger mechanism for particle pair creations is
+suggested.",0803.0410v3
+2008-06-04,"Broadband electrical detection of spin excitations in (Ga,Mn)As using a photovoltage technique","We report on microwave photovoltage and simultaneous magnetotransport
+measurements in a (Ga,Mn)As film oriented normal to the magnetic field. We
+detect the ferromagnetic resonance over a broad frequency range of 2 GHz to
+18.5 GHz and determine the spectroscopic g-factor and separate the Gilbert from
+the inhomogeneous contribution to magnetization relaxation. Temperature
+dependent measurements below the saturation magnetization indicate that the
+photovoltage signal can serve as a sensitive tool to study the crystal
+anisotropy. We demonstrate that the combination of spin dynamics with charge
+transport is a promising tool to study microstructured ferromagnetic
+semiconductor samples.",0806.0785v1
+2008-07-09,Lattice and magnetic instabilities in CaFe2As2: A single crystal neutron diffraction study,"Neutron diffraction measurements of a high quality single crystal of CaFe2As2
+are reported. A sharp transition was observed between the high temperature
+tetragonal and low temperature orthorhombic structures at TS = 172.5K (on
+cooling) and 173.5K (on warming). Coincident with the structural transition we
+observe a rapid, but continuous, ordering of the Fe moments, in a commensurate
+antiferromagnetic structure is observed, with a saturated moment of
+0.80(5)muB/Fe directed along the orthorhombic a-axis. The hysteresis of the
+structural transition is 1K between cooling and warming and is consistent with
+previous thermodynamic, transport and single crystal x-ray studies. The
+temperature onset of magnetic ordering shifts rigidly with the structural
+transition providing the clearest evidence to date of the coupling between the
+structural and magnetic transitions in this material and the broader class of
+iron arsenides.",0807.1525v3
+2008-08-22,Phases and magnetization process of an anisotropic Shastry-Sutherland model,"We examine ground state properties of the spin-1/2 easy-axis Heisenberg model
+on the Shastry-Sutherland lattice with ferromagnetic transverse spin exchange
+using quantum Monte Carlo and degenerate perturbation theory. For vanishing
+transverse exchange, the model reduces to an antiferromagnetic Ising model that
+besides Neel order harbors regions of extensive ground state degeneracy. In the
+quantum regime, we find a dimerized phase of triplet states, separated from the
+Neel ordered phase by a superfluid. The quantum phase transitions between these
+phases are characterized. The magnetization process shows a magnetization
+plateau at 1/3 of the saturation value, that persists down to the Ising limit,
+and a further plateau at 1/2 only in the quantum regime. For both plateaus, we
+determine the crystalline patterns of the localized triplet excitations. No
+further plateaus nor supersolid phases are found in this model.",0808.3104v1
+2008-09-05,Carrier-mediated antiferromagnetic interlayer exchange coupling in diluted magnetic semiconductor multilayers Ga$_{1-x}$Mn$_x$As/GaAs:Be,"We use neutron reflectometry to investigate the interlayer exchange coupling
+between Ga$_{0.97}$Mn$_{0.03}$As ferromagnetic semiconductor layers separated
+by non-magnetic Be-doped GaAs spacers. Polarized neutron reflectivity measured
+below the Curie temperature of Ga$_{0.97}$Mn$_{0.03}$As reveals a
+characteristic splitting at the wave vector corresponding to twice the
+multilayer period, indicating that the coupling between the ferromagnetic
+layers are antiferromagnetic (AFM). When the applied field is increased to
+above the saturation field, this AFM coupling is suppressed. This behavior is
+not observed when the spacers are undoped, suggesting that the observed AFM
+coupling is mediated by charge carriers introduced via Be doping. The behavior
+of magnetization of the multilayers measured by DC magnetometry is consistent
+with the neutron reflectometry results.",0809.0955v1
+2008-09-22,The T=0 random-field Ising model on a Bethe lattice with large coordination number: hysteresis and metastable states,"In order to elucidate the relationship between rate-independent hysteresis
+and metastability in disordered systems driven by an external field, we study
+the Gaussian RFIM at T=0 on regular random graphs (Bethe lattice) of finite
+connectivity z and compute to O(1/z) (i.e. beyond mean-field) the quenched
+complexity associated with the one-spin-flip stable states with magnetization m
+as a function of the magnetic field H. When the saturation hysteresis loop is
+smooth in the thermodynamic limit, we find that it coincides with the envelope
+of the typical metastable states (the quenched complexity vanishes exactly
+along the loop and is positive everywhere inside). On the other hand, the
+occurence of a jump discontinuity in the loop (associated with an infinite
+avalanche) can be traced back to the existence of a gap in the magnetization of
+the metastable states for a range of applied field, and the envelope of the
+typical metastable states is then reentrant. These findings confirm and
+complete earlier analytical and numerical studies.",0809.3774v1
+2008-09-24,Probing multi-band superconductivity and magnetism in SmFeAsO$_{0.8}$F$_{0.2}$ single crystals by high-field vortex torque magnetometry,"To probe manifestations of multiband superconductivity in oxypnictides, we
+measured the angular dependence of magnetic torque $\tau(\theta)$ in the mixed
+state of SmO$_{0.8}$F$_{0.2}$FeAs single crystals as functions of temperature
+$T$ and high magnetic field $H$ up to 30 T. We show that the effective mass
+anisotropy parameter $\gamma$ extracted from $\tau(\theta)$, can be greatly
+overestimated if the strong paramagnetism of Sm or Fe ions is not properly
+taken into account. The correctly extracted $\gamma$ depends on both $T$ and
+$H$, saturating at $\gamma \simeq 9$ at lower temperatures. Neither the London
+penetration depth nor the superfluid density is affected by high fields fields
+up to the upper critical field. Our results indicate two strongly-coupled
+superconducting gaps of nearly equal magnitudes.",0809.4223v2
+2008-10-22,Magnetic hyperthermia in single-domain monodisperse FeCo nanoparticles: Evidences for Stoner-Wohlfarth behaviour and large losses,"We report on hyperthermia measurements on a colloidal solution of 15 nm
+monodisperse FeCo nanoparticles (NPs). Losses as a function of the magnetic
+field display a sharp increase followed by a plateau, which is what is expected
+for losses of ferromagnetic single-domain NPs. The frequency dependence of the
+coercive field is deduced from hyperthermia measurement and is in quantitative
+agreement with a simple model of non-interacting NPs. The measured losses (1.5
+mJ/g) compare to the highest of the literature, though the saturation
+magnetization of the NPs is well below the bulk one.",0810.4109v1
+2008-10-24,Hyperactivated resistance in TiN films on the insulating side of the disorder-driven superconductor-insulator transition,"We investigate the insulating phase that forms in a titanium nitride film in
+a close vicinity of the disorder-driven superconductor-insulator transition. In
+zero magnetic field the temperature dependence of the resistance reveals a
+sequence of distinct regimes upon decreasing temperature crossing over from
+logarithmic to activated behavior with the variable-range hopping squeezing in
+between. In perpendicular magnetic fields below 2 T, the thermally activated
+regime retains at intermediate temperatures, whereas at ultralow temperatures,
+the resistance increases faster than that of the thermally activated type. This
+indicates a change of the mechanism of the conductivity. We find that at higher
+magnetic fields the thermally activated behavior disappears and the
+magnetoresistive isotherms saturate towards the value close to quantum
+resistance h/e^2.",0810.4351v2
+2008-11-20,How the Kondo ground state avoids the orthogonality catastrophe,"In the presence of a magnetic impurity the spin-up and down band states are
+modified differently by the impurity. If the multi-electron scalar product
+(MESP) between the occupied spin-up and down states approaches zero then this
+defines an orthogonality catastrophe. In the present paper the MESP is
+investigated for the FAIR (Friedel Artificial Iserted Resonance) solution for a
+Friedel-Anderson impurity. A basis of Wilson states is used. The MESP is
+numerically determined for the (enforced) magnetic, the singlet, and the
+triplet states as a function of the number N of Wilson states. The magnetic and
+the triplet state show an exponentially decreasing MESP as a function of N.
+Surprisingly it is not the number of states which causes this decrease. It is
+instead the energy separation of the highest occupied state from the Fermi
+energy which determines the reduction of the MESP. In the singlet state the
+ground-state requires a finite MESP to optimize its energy. As a consequence
+there is no orthogonality catastrophe. The MESP approaches a saturation value
+as function of N.",0811.3259v1
+2008-12-04,"Two-Dimensional particle-in-cell simulations of the nonresonant, cosmic-ray driven instability in SNR shocks","In supernova remnants, the nonlinear amplification of magnetic fields
+upstream of collisionless shocks is essential for the acceleration of cosmic
+rays to the energy of the ""knee"" at 10^{15.5}eV. A nonresonant instability
+driven by the cosmic ray current is thought to be responsible for this effect.
+We perform two-dimensional, particle-in-cell simulations of this instability.
+We observe an initial growth of circularly polarized non-propagating magnetic
+waves as predicted in linear theory. It is demonstrated that in some cases the
+magnetic energy density in the growing waves, can grow to at least 10 times its
+initial value. We find no evidence of competing modes, nor of significant
+modification by thermal effects. At late times we observe saturation of the
+instability in the simulation, but the mechanism responsible is an artefact of
+the periodic boundary conditions and has no counterpart in the supernova-shock
+scenario.",0812.0901v2
+2008-12-11,Cascade of magnetic-field-induced quantum phase transitions in a spin $\bm{1/2}$ triangular-lattice antiferromagnet,"We report magnetocaloric and magnetic-torque evidence that in
+Cs$_{2}$CuBr$_{4}$ -- a geometrically frustrated Heisenberg $S=1/2$
+triangular-lattice antiferromagnet -- quantum fluctuations stabilize a series
+of spin states at simple increasing fractions of the saturation magnetization
+$M_{s}$. Only the first of these states -- at $M={1/3}M_{s}$ -- has been
+theoretically predicted. We discuss how the higher fraction quantum states
+might arise and propose model spin arrangements. We argue that the first-order
+nature of the transitions into those states is due to strong lowering of the
+energies by quantum fluctuations, with implications for the general character
+of quantum phase transitions in geometrically frustrated systems.",0812.2077v2
+2008-12-17,The antiferromagnetic spin-1/2 Heisenberg model on the square lattice in a magnetic field,"We study the field dependence of the antiferromagnetic spin-1/2 Heisenberg
+model on the square lattice by means of exact diagonalizations. In a first
+part, we calculate the spin-wave velocity, the spin-stiffness, and the magnetic
+susceptibility and thus determine the microscopic parameters of the low-energy
+long-wavelength description. In a second part, we present a comprehensive study
+of dynamical spin correlation functions for magnetic fields ranging from zero
+up to saturation. We find that at low fields, magnons are well defined in the
+whole Brillouin zone, but the dispersion is substantially modified by quantum
+fluctuations compared to the classical spectrum. At higher fields, decay
+channels open and magnons become unstable with respect to multi-magnon
+scattering. Our results directly apply to inelastic neutron scattering
+experiments.",0812.3420v3
+2009-03-02,Attenuation and damping of electromagnetic fields: Influence of inertia and displacement current,"New results for attenuation and damping of electromagnetic fields in rigid
+conducting media are derived under the conjugate influence of inertia due to
+charge carriers and displacement current. Inertial effects are described by a
+relaxation time for the current density in the realm of an extended Ohm's law.
+The classical notions of poor and good conductors are rediscussed on the basis
+of an effective electric conductivity, depending on both wave frequency and
+relaxation time. It is found that the attenuation for good conductors at high
+frequencies depends solely on the relaxation time. This means that the
+penetration depth saturates to a minimum value at sufficiently high
+frequencies. It is also shown that the actions of inertia and displacement
+current on damping of magnetic fields are opposite to each other. That could
+explain why the classical decay time of magnetic fields scales approximately as
+the diffusion time. At very small length scales, the decay time could be given
+either by the relaxation time or by a fraction of the diffusion time, depending
+whether inertia or displacement current, respectively, would prevail on
+magnetic diffusion.",0903.0210v1
+2009-04-15,"Unified description of pairing, trionic and quarteting states for one-dimensional SU(4) attractive fermions","Paired states, trions and quarteting states in one-dimensional SU(4)
+attractive fermions are investigated via exact Bethe ansatz calculations. In
+particular, quantum phase transitions are identified and calculated from the
+quarteting phase into normal Fermi liquid, trionic states and spin-2 paired
+states which belong to the universality class of linear field-dependent
+magnetization in the vicinity of critical points. Moreover, unified exact
+results for the ground state energy, chemical potentials and complete phase
+diagrams for isospin $S=1/2, 1, 3/2$ attractive fermions with external fields
+are presented. Also identified are the magnetization plateaux of $m^z=M_s/3$
+and $m^z=2M_s/3$, where $M_s$ is the magnetization saturation value. The
+universality of finite-size corrections and collective dispersion relations
+provides a further test ground for low energy effective field theory.",0904.2269v1
+2009-07-21,Incommensurate spin correlations induced by magnetic Fe ions substituted into overdoped Bi1.75Pb0.35Sr1.90CuO6+z,"Spin correlations in the overdoped region of Bi1.75Pb0.35Sr1.90CuO6+z have
+been explored with Fe-doped single crystals characterized by neutron
+scattering, muon-spin-rotation (muSR) spectroscopy, and magnetic susceptibility
+measurements. Static incommensurate spin correlations induced by the Fe spins
+are revealed by elastic neutron scattering. The resultant incommensurability
+delta is unexpectedly large (~0.2 r.l.u.), as compared with delta ~ 1/8 in
+overdoped superconductor La2-xSrxCuO4. Intriguingly, the large delta in this
+overdoped region is close to the hole concentration p. This result is
+reminiscent of the delta ~ p trend observed in underdoped La2-xSrxCuO4;
+however, it is inconsistent with the saturation of delta in the latter compound
+in the overdoped regime. While our findings in Fe-doped
+Bi1.75Pb0.35Sr1.90CuO6+z support the commonality of incommensurate spin
+correlations in high-Tc cuprate superconductors, they also suggest that the
+magnetic response might be dominated by a distinct mechanism in the overdoped
+region.",0907.3590v2
+2009-08-04,Simulating Supersonic Turbulence in Magnetized Molecular Clouds,"We present results of large-scale three-dimensional simulations of weakly
+magnetized supersonic turbulence at grid resolutions up to 1024^3 cells. Our
+numerical experiments are carried out with the Piecewise Parabolic Method on a
+Local Stencil and assume an isothermal equation of state. The turbulence is
+driven by a large-scale isotropic solenoidal force in a periodic computational
+domain and fully develops in a few flow crossing times. We then evolve the flow
+for a number of flow crossing times and analyze various statistical properties
+of the saturated turbulent state. We show that the energy transfer rate in the
+inertial range of scales is surprisingly close to a constant, indicating that
+Kolmogorov's phenomenology for incompressible turbulence can be extended to
+magnetized supersonic flows. We also discuss numerical dissipation effects and
+convergence of different turbulence diagnostics as grid resolution refines from
+256^3 to 1024^3 cells.",0908.0378v1
+2009-09-28,Kinetic simulations of turbulent magnetic-field growth by streaming cosmic rays,"Efficient acceleration of cosmic rays (via the mechanism of diffusive shock
+acceleration) requires turbulent, amplified magnetic fields in the shock's
+upstream region. We present results of multidimensional particle-in-cell
+simulations aimed at observing the magnetic field amplification that is
+expected to arise from the cosmic-ray current ahead of the shock, and the
+impact on the properties of the upstream interstellar medium. We find that the
+initial structure and peak strength of the amplified field is somewhat
+sensitive to the choice of parameters, but that the field growth saturates in a
+similar manner in all cases: the back-reaction on the cosmic rays leads to
+modification of their rest-frame distribution and also a net transfer of
+momentum to the interstellar medium, substantially weakening their relative
+drift while also implying the development of a modified shock. The upstream
+medium becomes turbulent, with significant spatial fluctuations in density and
+velocity, the latter in particular leading to moderate upstream heating; such
+fluctuations will also have a strong influence on the shock structure.",0909.5212v1
+2009-10-08,Solar Magnetic Field Signatures in Helioseismic Splitting Coefficients,"Normal modes of oscillation of the Sun are useful probes of the solar
+interior. In this work, we use the even-order splitting coefficients to study
+the evolution of magnetic fields in the convection zone over solar cycle 23,
+assuming that the frequency splitting is only due to rotation and a large scale
+magnetic field. We find that the data are best fit by a combination of a
+poloidal field and a double-peaked near-surface toroidal field. The toroidal
+fields are centered at r=0.999R_solar and r=0.996R_solar and are confined to
+the near-surface layers. The poloidal field is a dipole field. The peak
+strength of the poloidal field is 124 +/- 17G. The toroidal field peaks at 380
++/- 30G and 1.4 +/- 0.2kG for the shallower and deeper fields respectively. The
+field strengths are highly correlated with surface activity. The toroidal field
+strength shows a hysteresis-like effect when compared to the global 10.7 cm
+radio flux. The poloidal field strength shows evidence of saturation at high
+activity.",0910.1597v1
+2009-10-11,"Magnetic and electrical properties of RCo2Mn (R=Ho, Er) compounds","The RCo2Mn (R= Ho and Er) alloys, crystallizing in the cubic MgCu2-type
+structure, are isostructural to RCo2 compounds. The excess Mn occupies both the
+R and the Co atomic positions. Magnetic, electrical and heat capacity
+measurements have been done in these comounds. The Curie temperature is found
+to be 248 K and 222 K for HoCo2Mn and ErCo2Mn respectively, which are
+considerably higher than that of the corresponding RCo2 compounds. Saturation
+magnetization values calculated in these samples are less compared to that of
+the corresponding RCo2 compounds. Heat capacity data have been fitted with the
+nonmagnetic contribution with Debye temperature =250 K and electronic
+coefficient=26 mJ mol^-1K^-2.",0910.2001v1
+2009-11-11,Temperature dependent nucleation and annihilation of individual magnetic vortices,"We studied the temperature dependence of the magnetization reversal in
+individual submicron permalloy disks with micro-Hall and bend-resistance
+magnetometry. The nucleation field exhibits a nonmonotonic dependence with
+positive and negative slopes at low and high temperatures, respectively, while
+the annihilation field monotonically decreases with increasing temperature, but
+with distinctly different slopes at low and high temperatures. Our analysis
+suggests that at low temperatures vortex nucleation and annihilation proceeds
+via thermal activation over an energy barrier, while at high temperatures they
+are governed by a temperature dependence of the saturation magnetization.",0911.2267v1
+2009-12-05,Electrical and magnetic transport properties of Fe3O4 thin films on GaAs (100) substrate,"Thin films of magnetite (Fe3O4) are grown on single crystal GaAs (100)
+substrate by pulsed laser deposition. X ray diffraction (XRD) result shows the
+(111) preferred orientation of the Fe3O4 film and x-ray photoelectron
+spectroscopy confirm the presence of single phase Fe3O4 in the film. The
+electrical transport property of the film shows the characteristic Verwey
+transition at 122 K and below 110 K, the transport follows variable range
+hopping type conduction mechanism. The film shows room temperature
+magnetization hysteresis loop suggesting the ferrimagnetic behavior of the film
+with saturation magnetization value close to 470 emu/cc.",0912.0979v1
+2009-12-26,Theory of Combined Photoassociation and Feshbach Resonances in a Bose-Einstein Condensate,"We model combined photoassociation and Feshbach resonances in a Bose-Einstein
+condensate, where the shared dissociation continuum allows for quantum
+interference in losses from the condensate, as well as a dispersive-like shift
+of resonance. A simple analytical model, based on the limit of weakly bound
+molecules, agrees well with numerical experiments that explicitly include
+dissociation to noncondensate modes. For a resonant laser and an off-resonant
+magnetic field, constructive interference enables saturation of the
+photoassociation rate at user-friendly intensities, at a value set by the
+interparticle distance. This rate limit is larger for smaller condensate
+densities and, near the Feshbach resonance, approaches the rate limit for
+magnetoassociation alone. Also, we find agreement with the unitary limit--set
+by the condensate size--only for a limited range of near-resonant magnetic
+fields. Finally, for a resonant magnetic field and an off-resonant laser,
+magnetoassociation displays similar quantum interference and a dispersive-like
+shift. Unlike photoassociation, interference and the fieldshift in resonant
+magnetoassociation is tunable with both laser intensity and detuning. Also, the
+dispersive-like shift of the Feshbach resonance depends on the size of the
+Feshbach molecule, and is a signature of non-universal physics in a strongly
+interacting system.",0912.5035v1
+2009-12-30,Spin torque and critical currents for magnetic vortex nano-oscillator in nanopillars,"We calculated the main dynamic parameters of the spin polarized current
+induced magnetic vortex oscillations in nanopillars, such as the range of
+current density, where a vortex steady oscillations exist, the oscillation
+frequency and orbit radius. We accounted for both the non-linear vortex
+frequency and non-linear vortex damping. To describe the vortex excitations by
+the spin polarized current we used a generalized Thiele approach to motion of
+the vortex core as a collective coordinate. All the calculation results are
+represented via the free layer sizes, saturation magnetization, Gilbert damping
+and the degree of the spin polarization of the fixed layer. Predictions of the
+developed model can be checked experimentally.",0912.5521v1
+2010-01-06,Properties of Light Flavour Baryons in Hypercentral quark model,"The light flavour baryons are studied within the quark model using the hyper
+central description of the three-body system. The confinement potential is
+assumed as hypercentral coulomb plus power potential ($hCPP_\nu$) with power
+index $\nu$. The masses and magnetic moments of light flavour baryons are
+computed for different power index, $\nu$ starting from 0.5 to 1.5. The
+predicted masses and magnetic moments are found to attain a saturated value
+with respect to variation in $\nu$ beyond the power index $\nu>$ 1.0. Further
+we computed transition magnetic moments and radiative decay width of light
+flavour baryons. The results are in good agreement with known experimental as
+well as other theoretical models.",1001.0849v2
+2010-01-15,Pressure-induced new magnetic phase in Tl(Cu$_{0.985}$Mg$_{0.015}$)Cl$_3$ probed by muon spin rotation,"We carried out zero-field muon-spin-rotation (ZF-$\mu$SR) measurements in
+hydrostatic pressures in impurity-doped quantum spin gap system
+Tl(Cu$_{0.985}$Mg$_{0.015}$)Cl$_3$ to investigate microscopic magnetic
+properties of the pressure-induced phase. The spontaneous muon spin precession,
+which indicates the existence of a long-range coherent order, is observed in
+pressures. With decreasing temperature in 3.1 kbar, the internal static
+magnetic field at the muon sites {\it H}$_{\rm int}$ tends to saturate to 280
+Oe around 4 K, however, decreases to 240 Oe at 2.3 K. These results suggest a
+rearrangement of ordered spins, and we speculate that the oblique
+antiferromagnetic phase, which is observed in the pressure of 14 kbar on the
+pure TlCuCl$_3$, appears in the Mg-doped system in lower pressures.",1001.2601v1
+2010-02-09,Magnetic Effects on Dielectric and Polarization Behavior of Multiferroic Hetrostructures,"PbZr0.52Ti0.48O3/La0.67Sr0.33MnO3(PZT/LSMO) bilayer with surface roughness ~
+1.8 nm thin films have been grown by pulsed laser deposition on LaAlO3(LAO)
+substrates. High remnant polarization (30-54 micro C/cm2), dielectric
+constant(400-1700), and well saturated magnetization were observed depending
+upon the deposition temperature of the ferromagnetic layer and applied
+frequencies. Giant frequency-dependent change in dielectric constant and loss
+were observed above the ferromagnetic-paramagnetic temperature. The frequency
+dependent dielectric anomalies are attributed to the change in metallic and
+magnetic nature of LSMO and also the interfacial effect across the bilayer; an
+enhanced magnetoelectric interaction may be due to the Parish-Littlewood
+mechanism of inhomogeneity near the metal-dielectric interface.",1002.1988v1
+2010-02-15,Optical determination and magnetic manipulation of single nitrogen-vacancy color center in diamond nanocrystal,"The controlled and coherent manipulation of individual quantum systems is a
+fundamental key for the development of quantum information processing. The
+nitrogen-vacancy (NV) color center in diamond is a promising system since its
+photoluminescence is perfectly stable at room temperature and its electron spin
+can be optically read-out at the individual level. We review here the
+experiments currently realized in our laboratory, concerning the use of single
+NV color center as single photon source and the coherent magnetic manipulation
+of the electron spin associated to a single NV color center. Furthermore, we
+demonstrate a nanoscopy experiment based on saturation absorption effect, which
+allows to optically pin-point single NV color center at a sub-? resolution.
+This opens a possibility to independently address two or multiple
+magnetically-coupled single NV color centers, which is a necessary step toward
+the realization of a diamond-based quantum computer.",1002.2902v1
+2010-03-05,Finite size effects with variable range exchange coupling in thin-film Pd/Fe/Pd trilayers,"The magnetic properties of thin-film Pd/Fe/Pd trilayers in which an embedded
+~1.5 A-thick ultrathin layer of Fe induces ferromagnetism in the surrounding Pd
+have been investigated. The thickness of the ferromagnetic trilayer is
+controlled by varying the thickness of the top Pd layer over a range from 8 A
+to 56 A. As the thickness of the top Pd layer decreases, or equivalently as the
+embedded Fe layer moves closer to the top surface, the saturated magnetization
+normalized to area and the Curie temperature decrease whereas the coercivity
+increases. These thickness-dependent observations for proximity-polarized
+thin-film Pd are qualitatively consistent with finite size effects that are
+well known for regular thin-film ferromagnets. The critical exponent $\beta$ of
+the order parameter (magnetization) is found to approach the mean field value
+of 0.5 as the thickness of the top Pd layer increases. The functional forms for
+the thickness dependences, which are strongly modified by the nonuniform
+exchange interaction in the polarized Pd, provide important new insights to
+understanding nanomagnetism in two-dimensions.",1003.1305v1
+2010-03-23,Intrinsic Room Temperature Ferromagnetism in Boron-doped ZnO,"We report room temperature ferromagnetism in boron-doped ZnO both
+experimentally and theoretically. The single phase Zn1-xBxO films deposited
+under high oxygen pressure by pulsed-laser deposition show ferromagnetic
+behavior at room temperature. The saturation magnetization increases
+monotonously from 0 to 1.5 emu/cm3 with the increasing of B component x from 0
+to 6.8%. The first-principles calculations based on density functional theory
+demonstrate that the ferromagnetism in B-doped ZnO originates from the induced
+magnetic moments of oxygen atoms in the nearest neighbor sites to the B-Zn
+vacancy pair. The calculated total magnetic moment increasing tendency with B
+component is well consistent with experiments.",1003.4423v1
+2010-03-23,Low frequency spin dynamics in the quantum magnet copper pyrazine dinitrate,"The S=1/2 antiferromagnetic Heisenberg chain exhibits a magnetic field driven
+quantum critical point. We study the low frequency spin dynamics in copper
+pyrazine dinitrate (CuPzN), a realization of this model system of quantum
+magnetism, by means of $^{13}$C-NMR spectroscopy. Measurements of the nuclear
+spin-lattice relaxation rate $T_1^{-1}$ in the vicinity of the saturation field
+are compared with quantum Monte Carlo calculations of the dynamic structure
+factor. Both show a strong divergence of low energy excitations at temperatures
+in the quantum regime. The analysis of the anisotropic $T_1^{-1}$-rates and
+frequency shifts allows one to disentangle the contributions from transverse
+and longitudinal spin fluctuations for a selective study and to determine the
+transfer of delocalized spin moments from copper to the neighboring nitrogen
+atoms.",1003.4535v1
+2010-05-29,{\it Ab initio} calculations of magnetic structure and lattice dynamics of Fe/Pt multilayers,"The magnetization distribution, its energetic characterization by the
+interlayer coupling constants and lattice dynamics of (001)-oriented Fe/Pt
+multilayers are investigated using density functional theory combined with the
+direct method to determine phonon frequencies. It is found that ferromagnetic
+order between consecutive Fe layers is favoured, with the enhanced magnetic
+moments at the interface. The bilinear and biquadratic coupling coefficients
+between Fe layers are shown to saturate fast with increasing thickness of
+nonmagnetic Pt layers which separate them. The phonon calculations demonstrate
+a rather strong dependence of partial iron phonon densities of states on the
+actual position of Fe monolayer in the multilayer structure.",1005.5454v1
+2010-06-01,Magnetic and humidity sensing properties of nanostructured Cu[x]Co[1-x]Fe2O4 synthesized by auto combustion technique,"Magnetic nanomaterials (23-43 nm) of Cu$_x$Co$_{1-x}$Fe$_2$O$_4$\ (x = 0.0,
+0.5 and 1.0) were synthesized by auto combustion method. The crystallite sizes
+of these materials were calculated from X-ray diffraction peaks. The band
+observed in Fourier transform infrared spectrum near 575 cm$^{-1}$ in these
+samples confirm the presence of ferrite phase. Conductivity measurement shows
+the thermal hysteresis and demonstrates the knee points at 475$^o$C, 525$^o$C
+and 500$^o$C for copper ferrite, cobalt ferrite and copper-cobalt mixed ferrite
+respectively. The hystersis M-H loops for these materials were traced using the
+Vibrating Sample Magnetometer (VSM) and indicate a significant increase in the
+saturation magnetization (M$_s$) and remanence (M$_r$) due to the substitution
+of Cu$^{2+}$ ions in cobalt ferrite, while the intrinsic coercivity (H$_c$) was
+decreasing. Among these ferrites, copper ferrite exhibits highest sensitivity
+for humidity.",1006.0083v1
+2010-06-29,Revealing the Exciton Fine Structure in PbSe Nanocrystal Quantum Dots,"We measure the photoluminescence (PL) lifetime, $\tau$, of excitons in
+colloidal PbSe nanocrystals (NCs) at low temperatures to 270~mK and in high
+magnetic fields to 15~T. For all NCs (1.3-2.3~nm radii), $\tau$ increases
+sharply below 10~K but saturates by 500~mK. In contrast to the usual picture of
+well-separated ``bright"" and ``dark"" exciton states (found, e.g., in CdSe NCs),
+these dynamics fit remarkably well to a system having two exciton states with
+comparable - but small - oscillator strengths that are separated by only
+300-900 $\mu$eV. Importantly, magnetic fields reduce $\tau$ below 10~K,
+consistent with field-induced mixing between the two states. Magnetic circular
+dichroism studies reveal exciton g-factors from 2-5, and magneto-PL shows
+$>$10\% circularly polarized emission.",1006.5673v1
+2010-08-10,On the resistivity at low temperatures in electron-doped cuprate superconductors,"We measured the magnetoresistance as a function of temperature down to 20mK
+and magnetic field for a set of underdoped PrCeCuO (x=0.12) thin films with
+controlled oxygen content. This allows us to access the edge of the
+superconducting dome on the underdoped side. The sheet resistance increases
+with increasing oxygen content whereas the superconducting transition
+temperature is steadily decreasing down to zero. Upon applying various magnetic
+fields to suppress superconductivity we found that the sheet resistance
+increases when the temperature is lowered. It saturates at very low
+temperatures. These results, along with the magnetoresistance, cannot be
+described in the context of zero temperature two dimensional
+superconductor-to-insulator transition nor as a simple Kondo effect due to
+scattering off spins in the copper-oxide planes. We conjecture that due to the
+proximity to an antiferromagnetic phase magnetic droplets are induced. This
+results in negative magnetoresistance and in an upturn in the resistivity.",1008.1682v1
+2010-08-19,Josephson Coupling and Fiske Dynamics in Ferromagnetic Tunnel Junctions,"We report on the fabrication of Nb/AlO_x/Pd_{0.82}Ni_{0.18}/Nb
+superconductor/insulator/ferromagnetic metal/superconductor (SIFS) Josephson
+junctions with high critical current densities, large normal resistance times
+area products, high quality factors, and very good spatial uniformity. For
+these junctions a transition from 0- to \pi-coupling is observed for a
+thickness d_F ~ 6 nm of the ferromagnetic Pd_{0.82}Ni_{0.18} interlayer. The
+magnetic field dependence of the \pi-coupled junctions demonstrates good
+spatial homogeneity of the tunneling barrier and ferromagnetic interlayer.
+Magnetic characterization shows that the Pd_{0.82}Ni_{0.18} has an out-of-plane
+anisotropy and large saturation magnetization, indicating negligible dead
+layers at the interfaces. A careful analysis of Fiske modes provides
+information on the junction quality factor and the relevant damping mechanisms
+up to about 400 GHz. Whereas losses due to quasiparticle tunneling dominate at
+low frequencies, the damping is dominated by the finite surface resistance of
+the junction electrodes at high frequencies. High quality factors of up to 30
+around 200 GHz have been achieved. Our analysis shows that the fabricated
+junctions are promising for applications in superconducting quantum circuits or
+quantum tunneling experiments.",1008.3341v1
+2010-08-26,Modulation of the ferromagnetic insulating phase in Pr0.8Ca0.2MnO3 by Co substitution,"Ferromagnetic insulator Pr0.8Ca0.2Mn1-yCoyO3 (0 <= y <= 0.7) thin films were
+epitaxially grown on (LaAlO3)0.3-(SrAl0.5Ta0.5O3)0.7 (100) substrates by pulsed
+laser deposition. To probe the ferromagnetic insulator state of hole-doped
+manganites, the Co content dependences of the structural, magnetic, and
+transport properties were studied. Variation of lattice constant by the
+substitution of Co ions is well reproduced considering that divalent and
+trivalent Co ions substitute for Mn ions at the perovskite B-sites. For 0 <= y
+<= 0.3, the Curie temperature, saturation magnetization, and magnetoresistance
+increase with increasing Co content, retaining the insulating properties.
+Detailed analyses of transport and magnetic properties indicate the
+contribution of both double exchange and superexchange interactions to the
+appearance of the ferromagnetic insulating phase.",1009.1524v2
+2010-09-20,Emergent Ising degrees of freedom in frustrated two-leg ladder and bilayer $s=1/2$ Heisenberg antiferromagnets,"Based on exact diagonalization data for finite quantum Heisenberg
+antiferromagnets on two frustrated lattices (two-leg ladder and bilayer) and
+analytical arguments we map low-energy degrees of freedom of the spin models in
+a magnetic field on classical lattice-gas models. Further we use
+transfer-matrix calculations and classical Monte Carlo simulations to give a
+quantitative description of low-temperature thermodynamics of the quantum spin
+models. The classical lattice-gas model yields an excellent description of the
+quantum spin models up to quite large temperatures. The main peculiarity of the
+considered frustrated bilayer is a phase transition which occurs at low
+temperatures for a wide range of magnetic fields below the saturation magnetic
+field and belongs to the two-dimensional Ising model universality class.",1009.3828v1
+2010-10-09,Superparamagnetism in Nanocrystalline Copper Ferrite Thin Films,"The rf sputtered copper ferrite films contain nanocrystalline grains. In
+these films, the magnetization does not saturate even in high magnetic fields.
+This phenomenon of high field susceptibility is attributed to the defects
+and/or superparamagnetic grains in the films. A simple model is developed to
+describe the observed high field magnetization behavior of these films. The
+model is found to fit well to the high field part for all the studied films. An
+attempt is also made to explain the temperature variation of the ferrimagnetic
+contribution on the basis of reported exchange constants.",1010.1877v1
+2010-11-02,Upper-hybrid wave driven Alfvenic turbulence in magnetized dusty plasmas,"The nonlinear dynamics of coupled electrostatic upper-hybrid (UH) and Alfven
+waves (AWs) is revisited in a magnetized electron-ion plasma with charged dust
+impurities. A pair of nonlinear equations that describe the interaction of UH
+wave envelopes (including the relativistic electron mass increase) and the
+density as well as the compressional magnetic field perturbations associated
+with the AWs is solved numerically to show that many coherent solitary patterns
+can be excited and saturated due to modulational instability of unstable UH
+waves. The evolution of these solitary patterns is also shown to appear in the
+states of spatiotemporal coherence, temporal as well as spatiotemporal chaos
+due to collision and fusion among the patterns in stochastic motion.
+Furthermore, these spatiotemporal features are demonstrated by the analysis of
+wavelet power spectra. It is found that a redistribution of wave energy takes
+place to higher harmonic modes with small wavelengths which, in turn, results
+into the onset of Alfvenic turbulence in dusty magnetoplasmas. Such a scenario
+can occur in the vicinity of Saturn's magnetosphere as many electrostatic
+solitary structures have been observed there by the Cassini spacecraft.",1011.0540v2
+2010-11-11,"Anomalous galvanomagnetism, cyclotron resonance and microwave spectroscopy of topological insulators","The surface quantum Hall state, magneto-electric phenomena and their
+connection to axion electrodynamics have been studied intensively for
+topological insulators. One of the obstacles for observing such effects comes
+from nonzero conductivity of the bulk. To overcome this obstacle we propose to
+use an external magnetic field to suppress the conductivity of the bulk
+carriers. The magnetic field dependence of galvanomagnetic and electromagnetic
+responses of the whole system shows anomalies due to broken time-reversal
+symmetry of the surface quantum Hall state, which can be used for its
+detection. In particular, we find linear bulk dc magnetoresistivity and a
+quadratic field dependence of the Hall angle, shifted rf cyclotron resonance,
+nonanalytic microwave transmission coefficient and saturation of the Faraday
+rotation angle with increasing magnetic field or wave frequency.",1011.2756v4
+2010-12-08,Tailoring the magnetism of GaMnAs films by ion irradiation,"Ion irradiation of semiconductors is a well understood method to tune the
+carrier concentration in a controlled manner. We show that the ferromagnetism
+in GaMnAs films, known to be hole-mediated, can be modified by He ion
+irradiation. The coercivity can be increased by more than three times. The
+magnetization, Curie temperature and the saturation field along the
+out-of-plane hard axis all decrease as the fluence increases. The electrical
+and structural characterization of the irradiated GaMnAs layers indicates that
+the controlled tailoring of magnetism results from a compensation of holes by
+generated electrical defects.",1012.1678v1
+2011-01-07,NMR relaxation rate in the field-induced octupolar liquid phase of spin-1/2 J1-J2 frustrated chains,"In the spin-1/2 frustrated chain with nearest-neighbor ferromagnetic exchange
+J1 and next-nearest-neighbor antiferromagnetic exchange J2 under magnetic
+field, magnetic multipolar-liquid (quadrupolar, octupolar, and hexadecapolar)
+phases are widely expanded from the saturation down to a low-field regime.
+Recently, we have clarified characteristic temperature and field dependence of
+the NMR relaxation rate 1/T_1 in the quadrupolar phase. In this paper, we
+examine those of 1/T_1 in the octupolar phase combining field theoretical
+method with numerical data. The relevance of the results to quasi
+one-dimensional J1-J2 magnets such as PbCuSO4(OH)2, Rb2Cu2Mo3O12 and Li2ZrCuO4
+is shortly discussed.",1101.1375v2
+2011-03-02,Switching dynamics of a magnetostrictive single-domain nanomagnet subjected to stress,"The temporal evolution of the magnetization vector of a single-domain
+magnetostrictive nanomagnet, subjected to in-plane stress, is studied by
+solving the Landau-Lifshitz-Gilbert equation. The stress is ramped up linearly
+in time and the switching delay, which is the time it takes for the
+magnetization to flip, is computed as a function of the ramp rate. For high
+levels of stress, the delay exhibits a non-monotonic dependence on the ramp
+rate, indicating that there is an {\it optimum} ramp rate to achieve the
+shortest delay. For constant ramp rate, the delay initially decreases with
+increasing stress but then saturates showing that the trade-off between the
+delay and the stress (or the energy dissipated in switching) becomes less and
+less favorable with increasing stress. All of these features are due to a
+complex interplay between the in-plane and out-of-plane dynamics of the
+magnetization vector induced by stress.",1103.0352v1
+2011-03-07,Magnetic Susceptibility of the Quark Condensate and Polarization from Chiral Models,"We compute the magnetic susceptibility of the quark condensate and the
+polarization of quarks at zero temperature and in a uniform magnetic
+background. Our theoretical framework consists of two chiral models that allow
+to treat self-consistently the spontaneous breaking of chiral symmetry: the
+linear $\sigma-$model coupled to quarks, dubbed quark-meson model, and the
+Nambu-Jona-Lasinio model. We also perform analytic estimates of the same
+quantities within the renormalized quark-meson model, both in the regimes of
+weak and strong fields. Our numerical results are in agreement with the recent
+literature; moreover, we confirm previous Lattice findings, related to the
+saturation of the polarization at large fields.",1103.1194v1
+2011-03-24,Supernova remnants as cosmic ray factories,"In this work we investigate particle acceleration in supernova remnant shocks
+within a semi-analytical formalism which self-consistently accounts for
+particle acceleration, amplification of the magnetic field via streaming
+instability and back-reaction of both accelerated particles and magnetic
+turbulence on the shock dynamics. In particular, we study the interplay between
+particle injection and magnetic field amplification, showing how a
+phenomenological but reasonable saturation of the standard streaming
+instability may lead to quite steep spectra for the accelerated particles. We
+comment on the implications that such a scenario may have on the comprehension
+of the diffuse spectrum of Galactic cosmic rays and of gamma-ray observations
+of single remnants.",1103.4798v1
+2011-03-28,From convective to stellar dynamos,"Convectively driven dynamos with rotation generating magnetic fields on
+scales large compared with the scale of the turbulent eddies are being
+reviewed. It is argued that such fields can be understood as the result of an
+alpha effect. Simulations in Cartesian domains show that such large-scale
+magnetic fields saturate on a time scale compatible with the resistive one,
+suggesting that the magnitude of the alpha effect is here still constrained by
+approximate magnetic helicity conservation. It is argued that, in the absence
+of shear and/or any other known large-scale dynamo effects, these simulations
+prove the existence of turbulent alpha^2-type dynamos. Finally, recent results
+are discussed in the context of solar and stellar dynamos.",1103.5475v1
+2011-04-29,Upper critical magnetic field in Ba_0.68K_0.32Fe_2As_2 and Ba(Fe_0.93Co_0.07)_2As_2,"We report measurements of the temperature dependence of the radio-frequency
+magnetic penetration depth in Ba_0.68K_0.32Fe_2As_2 and
+Ba(Fe_0.93Co_0.07)_2As_2 single crystals in pulsed magnetic fields up to 60 T.
+From our data, we construct an H-T phase diagram for the inter-plane (H || c)
+and in-plane (H || ab) directions for both compounds. For both field
+orientations in Ba_0.68K_0.32Fe_2As_2, we find a concave curvature of the
+Hc2(T) lines with decreasing anisotropy and saturation towards lower
+temperature. Taking into account Pauli spin paramagnetism we can describe
+Hc2(T) and its anisotropy. In contrast, we find that Pauli paramagnetic pair
+breaking is not essential for Ba(Fe_0.93Co_0.07)_2As_2. For this electron-doped
+compound, the data support a Hc2(T) dependence that can be described by the
+Werthamer Helfand Hohenberg model for H || ab and a two-gap behavior for H ||
+c.",1104.5619v1
+2011-06-28,Nonlinear small-scale dynamos at low magnetic Prandtl numbers,"Saturated small-scale dynamo solutions driven by isotropic non-helical
+turbulence are presented at low magnetic Prandtl numbers Pm down to 0.01. For
+Pm < 0.1, most of the energy is dissipated via Joule heat and, in agreement
+with earlier results for helical large-scale dynamos, kinetic energy
+dissipation is shown to diminish proportional to Pm^{1/2} down to values of
+0.1. In agreement with earlier work, there is, in addition to a short Golitsyn
+k^{-11/3} spectrum near the resistive scale also some evidence for a short
+k^{-1} spectrum on larger scales. The rms magnetic field strength of the
+small-scale dynamo is found to depend only weakly on the value of Pm and
+decreases by about a factor of 2 as Pm is decreased from 1 to 0.01. The
+possibility of dynamo action at Pm=0.1 in the nonlinear regime is argued to be
+a consequence of a suppression of the bottleneck seen in the kinetic energy
+spectrum in the absence of a dynamo and, more generally, a suppression of
+kinetic energy near the dissipation wavenumber.",1106.5777v2
+2011-07-14,Anomalous Coexistence of Ferroelectric Phases ($P\parallel a$ and $P\parallel c$) in Orthorhombic Eu$_{1-y}$Y$_y$MnO$_3$ ($y>0.5$) Crystals,"We have investigated the magnetic and dielectric properties of orthorhombic
+Eu$_{1-y}$Y$_y$MnO$_3$ ($0\leq y\leq 0.6$) single crystals without the presence
+of the 4$f$ magnetic moments of the rare-earth ions. In $y\geq 0.2$, the
+magnetic-structure driven ferroelectricity is observed. The ferroelectric
+transition temperature is steeply reducing with increasing $y$. In $y\geq
+0.52$, two ferroelectric phases ($P\parallel a$ and $P\parallel c$) are
+coexistent at low temperatures. In these phases, ferroelectricity has different
+origin, which is evidenced by the distinctive poling-electric-field dependence
+of electric polarization. Namely, the electric polarization along the c axis
+($P_c$) is easily saturated by a poling electric field, therefore $P_c$ is
+caused by the $bc$ spiral antiferromagnetic order. On the other hand, the
+electric polarization along the a axis ($P_a$) is probably attributed to the
+collinear $E$-type antiferromagnetic order, because $P_a$ is unsaturated even
+in a poling field of $10^6$ V/m.",1107.2733v1
+2011-08-14,High pressure sequence of Ba_3NiSb_2O_9 structural phases: new $S = 1$ quantum spin-liquids based on Ni^{2+},"By using a high pressure, high temperature (HPHT) technique, the
+antiferromagnetically ordered ($T_N$ = 13.5 K) 6H-A phase of
+Ba$_3$NiSb$_2$O$_9$ was transformed into two new gapless quantum spin
+liquid(QSL) candidates with S=1 (Ni$^{2+}$) moments: the 6H-B phase with a
+Ni$^{2+}$-triangular lattice and the 3C-phase with a
+Ni$^{2+}$-three-dimensional (3D) edge-shared tetrahedral lattice. Both
+compounds show no magnetic order down to 0.35 K despite Curie-Weiss
+temperatures $\theta_{CW}$ of -75.5 K (6H-B) and -182.5 K (3C), respectively.
+Below $\sim 25$ K the magnetic susceptibility of the 6H-B phase saturates to a
+constant value $\chi_0 = 0.013 $ emu/mol which is followed below 7 K, by a
+linear-temperature dependent magnetic specific heat ($C_M$) displaying a giant
+coefficient $\gamma$ = 168 mJ/mol-K$^2$. Both observations suggest the
+development of a Fermi-liquid like ground state characterized by a Wilson ratio
+of 5.6 in this insulating material. For the 3C phase, the $C_M \propto T^2$
+behavior indicates a unique S=1, 3D QSL ground-state.",1108.2897v1
+2011-12-20,The Effect of Anisotropic Conduction on the Thermal Instability in the Interstellar Medium,"Thermal instability (TI) can strongly affect the structure and dynamics of
+the interstellar medium (ISM) in the Milky Way and other disk galaxies. Thermal
+conduction plays an important role in the TI by stabilizing small scales and
+limiting the size of the smallest condensates. In the magnetized ISM, however,
+heat is conducted anisotropically (primarily along magnetic field lines). We
+investigate the effects of anisotropic thermal conduction on the nonlinear
+regime of the TI by performing two-dimensional magnetohydrodynamic simulations.
+We present models with magnetic fields of different initial geometries and
+strengths, and compare them to hydrodynamic models with isotropic conduction.
+We find anisotropic conduction does not significantly alter the overall density
+and temperature statistics in the saturated state of the TI. However, it can
+strongly affect the shapes and sizes of cold clouds formed by the TI. For
+example, for uniform initial fields long filaments of cold gas are produced
+that are reminiscent of some observed HI clouds. For initially tangled fields,
+such filaments are not produced. We also show that anisotropic conduction
+suppresses turbulence generated by evaporative flows from the surfaces of cold
+blobs, which may have implications for mechanisms for driving turbulence in the
+ISM.",1112.4841v1
+2012-02-27,Exact ground state of a frustrated integer-spin modified Shastry-Sutherland model,"We consider a two-dimensional geometrically frustrated integer-spin
+Heisenberg system that admits an exact ground state. The system corresponds to
+a decorated square lattice with two coupling constants J1 and J2, and it can be
+understood as a generalized Shastry-Sutherland model. Main elements of the spin
+model are suitably coupled antiferromagnetic spin trimers with integer spin
+quantum numbers s and their ground state Phi will be the product state of the
+local singlet ground states of the trimers. We provide exact numerical data for
+finite lattices as well as analytical considerations to estimate the range of
+the existence in dependence on the ratio of the two couplings constants J2 and
+J1 and on the spin quantum number s. Moreover, we find that the magnetization
+curves as a function of the applied magnetic field shows plateaus and jumps. In
+the classical limit s \to \infty the model exhibits phases of three- and
+two-dimensional ground states separated by a one-dimensional (collinear)
+plateau state at 1/3 of the saturation magnetization.",1202.5854v1
+2012-03-17,Magnetic Phase Transition and Relaxation Effects in LiFePO4,"We report the observation of para - antiferromagnetic transition at ~ 50 K in
+lithium iron phosphate, LiFePO4 through DC magnetization and M\""ossbauer
+spectroscopy. The Ferrous ion Fe2+ (3d6, 5D) in LiFePO4 exhibits relaxation
+effects with a relaxation frequency ~1.076 \times 10(rise to 7) s-1 at 300 K.
+The temperature dependence of the frequency suggests the origin of the
+relaxation is spin-lattice type. The quadrupole splitting at low temperatures
+indicates the excited orbital states mix strongly to the orbital doublet ground
+state via spin-orbit coupling. Modified molecular field model analysis yields a
+saturation value for hyperfine field ~125 kOe. The anomaly in magnetization and
+M\""ossbauer parameters below 27 K may be ascribed to contribution of orbital
+angular momentum. The high value of the asymmetry parameter ({\eta} ~ 0.8) of
+the electric field gradient obtained in the antiferromagnetic regime indicates
+a strongly distorted octahedral oxygen neighbourhood for the ferrous sites.",1203.3863v2
+2012-04-15,Efect of magnetic Gd impurities on superconductivity in MoGe films with different thickness and morphology,"We studied the effect of magnetic doping with Gd atoms on the superconducting
+properties of amorphous Mo70Ge30 films. We observed that in uniform films
+deposited on amorphous Ge, the pair-breaking strength per impurity strongly
+decreases with film thickness initially and saturates at a finite value in
+films with thickness below the spin-orbit scattering length. The variation is
+likely caused by surface induced magnetic anisotropy and is consistent with the
+fermionic mechanism of superconductivity suppression. In thin films deposited
+on SiN the pair-breaking strength becomes zero. Possible reasons for this
+anomalous response are discussed. The morphological distinctions between the
+films of the two types were identified using atomic force microscopy with a
+carbon nanotube tip.",1204.3334v1
+2012-05-10,DC magnetic field generation in unmagnetized shear flows,"The generation of DC magnetic fields in unmagnetized plasmas with velocity
+shear is predicted for non relativistic and relativistic scenarios either due
+to thermal effects or due to the onset of the Kelvin-Helmholtz instability
+(KHI). A kinetic model describes the growth and the saturation of the DC field.
+The predictions of the theory are confirmed by multidimensional
+particle-in-cell simulations, demonstrating the formation of long lived
+magnetic fields ($t \sim 100s \omega_{pi}^{-1}$) along the full longitudinal
+extent of the shear layer, with transverse width on the electron length scale
+($\sqrt{\gamma_0}c/\omega_{pe}$), reaching magnitudes
+$eB_{\mathrm{DC}}/m_ec\omega_{pe}\sim \beta_0\sqrt{\gamma_0}$.",1205.2293v3
+2012-05-21,Cyclic magnetic activity due to turbulent convection in spherical wedge geometry,"We report on simulations of turbulent, rotating, stratified,
+magnetohydrodynamic convection in spherical wedge geometry. An initially
+small-scale, random, weak-amplitude magnetic field is amplified by several
+orders of magnitude in the course of the simulation to form oscillatory
+large-scale fields in the saturated state of the dynamo. The differential
+rotation is solar-like (fast equator), but neither coherent meridional poleward
+circulation nor near-surface shear layer develop in these runs. In addition to
+a poleward branch of magnetic activity beyond 50 degrees latitude, we find for
+the first time a pronounced equatorward branch at around 20 degrees latitude,
+reminiscent of the solar cycle.",1205.4719v2
+2012-07-16,Influence of the magnetic field on the plasmonic properties of transparent Ni anti-dot arrays,"Extraordinary optical transmission is observed due to the excitation of
+surface plasmon polaritons (SPPs) in 2-Dimensional hexagonal anti-dot patterns
+of pure Ni thin films, grown on sapphire substrates. A strong enhancement of
+the polar Kerr rotation is recorded at the surface plasmon related transmission
+maximum. Angular resolved reflectivity measurements under an applied field,
+reveal an enhancement and a shift of the normalized reflectivity difference
+upon reversal of the magnetic saturation (transverse magneto-optical Kerr
+effect-TMOKE). The change of the TMOKE signal clearly shows the magnetic field
+modulation of the dispersion relation of SPPs launched in a 2D patterned
+ferromagnetic Ni film.",1207.3697v1
+2012-07-20,Three-Dimensional Relativistic Magnetohydrodynamic Simulations of Current-Driven Instability. III. Rotating Relativistic Jets,"We have investigated the influence of jet rotation and differential motion on
+the linear and nonlinear development of the current-driven (CD) kink
+instability of force-free helical magnetic equilibria via three-dimensional
+relativistic magnetohydrodynamic simulations. In this study, we follow the
+temporal development within a periodic computational box. Displacement of the
+initial helical magnetic field leads to the growth of the CD kink instability.
+We find that, in accord with linear stability theory, the development of the
+instability depends on the lateral distribution of the poloidal magnetic field.
+If the poloidal field significantly decreases outwards from the axis, the
+initial small perturbations grow strongly, and if multiple wavelengths are
+excited non-linear interaction eventually disrupts the initial cylindrical
+configuration. When the profile of the poloidal field is shallow, the
+instability develops slowly and eventually saturates. We briefly discuss
+implications of our findings for Poynting dominated jets.",1207.4949v1
+2012-10-03,Torsional Oscillations in a Global Solar Dynamo,"We characterize and analyze rotational torsional oscillations developing in a
+large-eddy magnetohydrodynamical simulation of solar convection (Ghizaru,
+Charbonneau, and Smolarkiewicz, Astrophys. J. Lett., 715, L133 (2010); Racine
+et al., Astrophys. J., 735, 46 (2011)) producing an axisymmetric large-scale
+magnetic field undergoing periodic polarity reversals. Motivated by the many
+solar-like features exhibited by these oscillations, we carry out an analysis
+of the large-scale zonal dynamics. We demonstrate that simulated torsional
+oscillations are not driven primarily by the periodically-varying large-scale
+magnetic torque, as one might have expected, but rather via the magnetic
+modulation of angular-momentum transport by the large-scale meridional flow.
+This result is confirmed by a straightforward energy analysis. We also detect a
+fairly sharp transition in rotational dynamics taking place as one moves from
+the base of the convecting layers to the base of the thin tachocline-like shear
+layer formed in the stably stratified fluid layers immediately below. We
+conclude by discussing the implications of our analyses with regards to the
+mechanism of amplitude saturation in the global dynamo operating in the
+simulation, and speculate on the possible precursor value of torsional
+oscillations for the forecast of solar cycle characteristics.",1210.1209v1
+2012-10-08,Sputter gas pressure effects on the properties of Sm-Co thin films deposited from a single target,"We grow epitaxial Sm-Co thin films by sputter deposition from an alloy target
+with a nominal SmCo5 composition on Cr(100)-buffered MgO(100) single-crystal
+substrates. By varying the Ar gas pressure, we can change the composition of
+the film from a SmCo5-like to a Sm2Co7-like phase. The composition, crystal
+structure, morphology and magnetic properties of these films have been
+determined using Rutherford Backscattering, X-ray diffraction and magnetization
+measurements. We find that the various properties are sensitive to the sputter
+background pressure in different ways. In particular, the lattice parameter
+changes in a continuous way, the coercive fields vary continuously with a
+maximum value of 3.3 T, but the saturation magnetization peaks when the lattice
+parameter is close to that of Sm2Co7. Moreover, we find that the Sm content of
+the films is higher than expected from the expected stoichiometry.",1210.2240v1
+2012-10-17,Turbulence in weakly-ionized proto-planetary disks,"We investigate the characteristic properties of self-sustained MRI turbulence
+in low-ionized proto-planetary disks. We study the transition regime between
+active and dead-zone, performing 3D global non-ideal MHD simulations of
+stratified disk covering range of magnetic Reynolds number between 2700 < Rm <
+6600. We found converged and saturated MRI turbulence for Rm > 5000 with a
+strength of alpha ~ 0.01. Below Rm < 5000 the MRI starts to decay at the
+midplane, having Elsasser numbers below one. We find a transition regime
+between 3300 < Rm < 5000 where the MRI turbulence is still sustained but
+damped. At around Rm < 3000 the MRI turbulence decays but could reestablished
+due to the accumulation of toroidal magnetic field or the radial transport of
+magnetic field from the active region. Below Rm < 3000 the MRI cannot be
+sustained and is decaying. Here hydro-dynamical motions, like density waves
+dominate. We observe anti-cyclonic vortices in the transition between dead-zone
+and active zone.",1210.4669v1
+2012-11-12,Magnetic and transport properties of tetragonal- or cubic-Heusler-type Co-substituted Mn-Ga epitaxial thin films,"The composition dependence of the structural, magnetic, and transport
+properties of epitaxially grown Mn-Co-Ga films were investigated. The crystal
+structure was observed to change from tetragonal to cubic as the Co content was
+increased. In terms of the dependence of saturation magnetization on the Co
+content, relatively small value was obtained for the
+Mn$_{2.3}$Co$_{0.4}$Ga$_{1.3}$ film at a large {\it K}$_\textrm u$ value of 9.2
+Merg/cm$^3$. Electrical resistivity of Mn-Co-Ga films was larger than that of
+pure Mn-Ga film. The maximum value of the resistivity was 490 $\mu\Omega$cm for
+Mn$_{2.2}$Co$_{0.6}$Ga$_{1.2}$ film. The high resistivity of Mn-Co-Ga might be
+due to the presence of localized electron states in the films due to chemical
+disordering caused by the Co substitution.",1211.2524v1
+2012-11-20,Microscopic magnetic structuring of a spin-wave waveguide by ion implantation in a Ni(81)Fe(19) layer,"We investigate the spin-wave excitation in microscopic waveguides fabricated
+by localized Cr+ ion implantation in a ferromagnetic Ni(81)Fe(19) film. We
+demonstrate that spin-wave waveguides can be conveniently made by this
+technique. The magnetic patterning technique yields an increased damping and a
+reduction in saturation magnetization in the implanted regions that can be
+extracted from Brillouin light scattering measurements of the spin-wave
+excitation spectra. Furthermore, the waveguide performance as well as the
+internal field of the waveguide depend on the doping fluence. The results prove
+that localized ion implantation is a powerful tool for the patterning of magnon
+spintronic devices.",1211.4786v1
+2012-11-21,Spin-wave propagation and transformation in a thermal gradient,"The influence of a thermal gradient on the propagation properties of
+externally excited dipolar spin waves in a magnetic insulator waveguide is
+investigated. It is shown that spin waves propagating towards a colder region
+along the magnetization direction continuously reduce their wavelength. The
+wavelength increase of a wave propagating into a hotter region was utilized to
+realize its decomposition in the partial waveguide modes which are reflected at
+different locations. This influence of temperature on spin-wave properties is
+mainly caused by a change in the saturation magnetization and yields promising
+opportunities for the manipulation of spin waves in spin-caloritronic
+applications.",1211.5017v1
+2012-12-07,Current helicity constraints in solar dynamo models,"We investigate to what extent the current helicity distribution observed in
+solar active regions is compatible with solar dynamo models. We use an advanced
+2D mean-field dynamo model with dynamo action largely concentrated near the
+bottom of the convective zone, and dynamo saturation based on the evolution of
+the magnetic helicity and algebraic quenching. For comparison, we also studied
+a more basic 2D mean-field dynamo model with simple algebraic alpha quenching
+only. Using these numerical models we obtain butterfly diagrams for both the
+small-scale current helicity and the large-scale magnetic helicity, and compare
+them with the butterfly diagram for the current helicity in active regions
+obtained from observations. This comparison shows that the current helicity of
+active regions, as estimated by $-A \cdot B$ evaluated at the depth from which
+the active region arises, resembles the observational data much better than the
+small-scale current helicity calculated directly from the helicity evolution
+equation. Here $B$ and $A$ are respectively the dynamo generated mean magnetic
+field and its vector potential.",1212.1643v1
+2013-01-07,Quantum Hall Effect in Hydrogenated Graphene,"The quantum Hall effect is observed in a two-dimensional electron gas formed
+in millimeter-scale hydrogenated graphene, with a mobility less than 10
+$\mathrm{cm^{2}/V\cdot s}$ and corresponding Ioffe-Regel disorder parameter
+$(k_{F}\lambda)^{-1}\gg1$. In zero magnetic field and low temperatures, the
+hydrogenated graphene is insulating with a two-point resistance of order of
+$250 h/e^2$. Application of a strong magnetic field generates a negative
+colossal magnetoresistance, with the two-point resistance saturating within
+0.5% of $h/2e^{2}$ at 45T. Our observations are consistent with the opening of
+an impurity-induced gap in the density of states of graphene. The interplay
+between electron localization by defect scattering and magnetic confinement in
+two-dimensional atomic crystals is discussed.",1301.1257v1
+2013-01-18,Unusual persistence of superconductivity against high magnetic fields in the strongly-correlated iron-chalcogenide film FeTe:O$_{x}$,"We report an unusual persistence of superconductivity against high magnetic
+fields in the iron chalcogenide film FeTe:O$_{x}$ below ~ 2.5 K. Instead of
+saturating like a mean-field behavior with a single order parameter, the
+measured low-temperature upper critical field increases progressively,
+suggesting a large supply of superconducting states accessible via magnetic
+field or low-energy thermal fluctuations. We demonstrate that superconducting
+states of finite momenta can be realized within the conventional theory,
+despite its questionable applicability. Our findings reveal a fundamental
+characteristic of superconductivity and electronic structure in the
+strongly-correlated iron-based superconductors.",1301.4487v3
+2013-02-07,Three-dimensional artificial neural network model of the dayside magnetopause,"Artificial Neural Networks (ANN) from package NeuroShell 2 are applied for
+modeling of dayside magnetopause. The model data set is based on the
+magnetopause crossings and on the corresponding hour-averaged measurements of
+solar wind plasma and interplanetary magnetic field. ANN model represents 3D
+shape and size of the dayside magnetopause in dependence on solar wind dynamic
+pressure, Bz and By components of interplanetary magnetic field. The model
+permits firstly to describe dynamics of the magnetic cusp and global asymmetry
+of the dayside magnetopause under wide range of the external conditions.
+Slightly change of the magnetopause size with change of By absolute value is
+presented quantitatively in the form of analytical expression. ANN model shows
+three regimes of the magnetopause dynamics that controlled by Bz component:
+pressure balance regime (Bz>0 nT), reconnection regime (0>Bz>-10 nT) and regime
+of reconnection saturation (Bz<-10 nT). Three different regimes of magnetopause
+dynamics at the subsolar point are described by modified pressure balance
+equation obtained from ANN model.",1302.1704v1
+2013-03-01,Parallel pumping of magnetic vortex gyrations in spin-torque nano-oscillators,"We experimentally demonstrate that large magnetic vortex oscillations can be
+parametrically excited in a magnetic tunnel junction by the injection of
+radio-frequency (rf) currents at twice the natural frequency of the gyrotropic
+vortex core motion. The mechanism of excitation is based on the parallel
+pumping of vortex motion by the rf orthoradial field generated by the injected
+current. Theoretical analysis shows that experimental results can be
+interpreted as the manifestation of parametric amplification when rf current is
+small, and of parametric instability when rf current is above a certain
+threshold. By taking into account the energy nonlinearities, we succeed to
+describe the amplitude saturation of vortex oscillations as well as the
+coexistence of stable regimes.",1303.0225v1
+2013-03-08,Ultracold neutron accumulation in a superfluid-helium converter with magnetic multipole reflector,"We analyze accumulation of ultracold neutrons (UCN) in a superfluid-helium
+converter vessel surrounded by a magnetic multipole reflector. We solved the
+spin-dependent rate equation, employing formulas valid for adiabatic spin
+transport of trapped UCN in mechanical equilibrium. Results for saturation UCN
+densities are obtained in dependence of order and strength of the multipolar
+field. The addition of magnetic storage to neutron optical potentials can
+increase the density and energy of the low field seeking UCN produced and
+serves to mitigate the effects of wall losses on the source performance. It
+also can provide a highly polarized sample of UCN without need to polarize the
+neutron beam incident on the converter. This work was performed in preparation
+of the UCN source project SuperSUN at the ILL.",1303.1944v2
+2013-03-25,First Study of Intersubband Absorption in Electrons on Helium under Quantizing Magnetic Fields,"We present the first measurements of inter-subband absorption of microwaves
+in surface electrons on liquid helium subjected to perpendicular magnetic field
+B. In quantizing B, the power absorption shows intermittent regions of enhanced
+and suppressed absorption. This behavior is caused by strong variation of the
+excited-electron decay rate with B. Particularly, fast decay due to elastic
+scattering provides condition for strong absorption and overheating of the
+electron system, while slow decay due to inelastic scattering limits absorption
+and causes its saturation. An unexpected feature is the strong suppression of
+absorption at magnetic fields where the inter-subband energy splitting is a
+multiple number of the cyclotron energy.",1303.6044v1
+2013-04-09,Half-metallicity and anisotropy magnetoresistance properties of Heusler alloys Fe2Co1-xCrxSi,"In this paper, we investigate the half-metallicity of Heusler alloys
+Fe2Co1-xCrxSi by first principles calculations and anisotropy magnetoresistance
+measurements. It is found that, with the increase of Cr content x, the Fermi
+level of Fe2Co1-xCrxSi moves from the top of valence band to the bottom of
+conduction band, and a large half-metallic band gap of 0.75 eV is obtained for
+x=0.75. We then successfully synthesized a series Heusler Fe2Co1-xCrxSi
+polycrystalline ribbon samples. The results of X-ray diffraction indicate that
+the Fe2Co1-xCrxSi series of samples are pure phase with a high degree of order
+and the saturation magnetic moment follows half-metallic Slater-Pauling rule.
+Except for the two end members, Fe2CoSi and Fe2CrSi, the anisotropic
+magnetoresistance of Fe2Co1-xCrxSi (x=0.25, 0.5, 0.75) show a negative value
+suggesting they are stable half-metallic ferromagnets.",1304.2602v1
+2013-05-22,Field-induced spin-structural transition and giant magnetostriction in Ising chain $α$-CoV$_2$O$_6$,"We have investigated the temperature and magnetic field dependence of
+magnetization, specific heat ($C_p$), and relative sample length change
+($\Delta L/L_0$) for understanding the field-induced spin-structural change in
+quasi-one-dimensional spin chain $\alpha$-CoV$_2$O$_6$ which undergoes
+antiferromagnetic (AFM) transition below $T_N$$=$15 K. Analysis of $C_p$($T$)
+shows that an effective $S$$=$1/2 Ising state is realized below 20 K, though
+the magnetic fluctuations persist well above $T_N$. $C_p$ and the coefficient
+of linear thermal expansion ($\alpha$) exhibit strong $H$ dependence in the AFM
+state. We also observe a huge positive magnetostriction [$\Delta L$($H$)/$L_0$]
+below 20 K which does not show any tendency of saturation up to 9 T. With
+increasing field, a sharp and symmetric peak emerges below $T_N$ in both
+$C_p$($T$) and $\alpha$($T$) due to field-induced first order
+ferrimagnetic/ferromagnetic-paramagnetic transitions. The large value of
+magnetostriction below $T_N$ suggests strong spin-lattice coupling in
+$\alpha$-CoV$_2$O$_6$.",1305.5027v2
+2013-05-29,Exact Ground States of Frustrated Spin-1 Ising-Heisenberg and Heisenberg Ladders in a Magnetic Field,"Ground states of the frustrated spin-1 Ising-Heisenberg two-leg ladder with
+Heisenberg intra-rung coupling and only Ising interaction along legs and
+diagonals are rigorously found by taking advantage of local conservation of the
+total spin on each rung. The constructed ground-state phase diagram of the
+frustrated spin-1 Ising-Heisenberg ladder is then compared with the analogous
+phase diagram of the fully quantum spin-1 Heisenberg two-leg ladder obtained by
+density matrix renormalization group (DMRG) calculations. It is demonstrated
+that both investigated spin models exhibit quite similar magnetization
+scenarios, which involve intermediate plateaux at one-quarter, one-half and
+three-quarters of the saturation magnetization.",1305.6703v1
+2013-05-30,Suppression of ferromagnetism in the LaVxCr1-xGe3 system,"We report synthesis of hexagonal LaVxCr1-xGe3 (x = 0-0.21, 1.00) single
+crystals, and present a systematic study of this series by measurements of
+temperature and field dependent magnetic susceptibility, magnetization,
+resistivity, and specific heat. Ferromagnetism has been observed for x =
+0-0.21, and the system manifests a strong axial anisotropy in its ordered
+state. The decrease of the saturated moment and the effective moment per Cr
+with the increase of V-concentration suggests this is an itinerant
+ferromagnetic system. The Curie temperature declines monotonically as the
+V-concentration increases. Single crystalline samples could only be grown for
+x-values up to 0.21 for which the transition temperature was suppressed down to
+36 K. Although we could not fully suppress TC via V-substitution, for x = 0.16,
+we performed magnetization measurements under pressure. The ferromagnetic state
+is suppressed under pressure at an initial rate of dTC/dp = -11.7 K/GPa and
+vanishes by 3.3 GPa.",1305.7258v1
+2013-06-11,Magnetically Active Stars in Taurus-Auriga: Activity and Rotation,"A sample of 70 magnetically active stars toward the Taurus-Auriga
+star-forming region has been investigated. The positions of the sample stars on
+the Rossby diagram have been analyzed. All stars are shown to be in the regime
+of a saturated dynamo, where the X-ray luminosity reaches its maximum and does
+not depend on the Rossby number. A correlation has been found between the
+lithium line equivalent width and the age of a solar-mass (from 0.7 to 1.2
+Msun) pre-main-sequence star. The older the age, the smaller the Li line
+equivalent width. Analysis of the long-term photometric variability of these
+stars has shown that the photometric activity of the youngest stars is
+appreciably higher than that of the older objects from the sample. This result
+can be an indirect confirmation of the evolution of the magnetic field in
+pre-main-sequence stars from predominantly dipole and axisymmetric to multipole
+and nonaxisymmetric.",1306.2651v1
+2013-07-11,"Stable Spin State Analysis of Fe, Co, Ni-modified Graphene-ribbon","Magnetic graphene-ribbon is a candidate for realizing future ultra high
+density 100 tera bit/inch2 class data storage media. In order to increase the
+saturation magnetization, first principles DFT analysis was done for Fe, Co,
+Ni-modified zigzag edge graphene-ribbon. Typical unit cell is [C32H2Fe1],
+[C32H2Co1] and [C32H2Ni1] respectively. Most stable spin state was Sz=4/2 for
+Fe-modified case, whereas Sz=3/2 for Co-case and Sz=2/2 for Ni-case. Magnetic
+moment of Fe,Co, and Ni were 3.63, 2.49 and 1.26 {\mu}B, which can be explained
+by the Hund-rule considering charge donation to neighboring carbons. Band
+calculation shows half-metal like structure with a large band gap (in Co-case,
+0.55eV) for up-spin, whereas very small gap (0.05eV) for down-spin, which will
+be useful for many featured application like information storage, spin filter
+and magneto-resistance devices. Dual layer Fe-modified ribbon shows a tube like
+curved structure, which may suggest a carbon nanotube creation by Fe catalyst.",1307.2960v1
+2013-07-12,Singlet-triplet Crossover in the Two-dimensional Dimer Spin System YbAl3C3,"Low-temperature magnetization (M) measurements down to 0.1 K have been
+performed in magnetic fields up to 14.5 T for a single piece of a tiny
+single-crystalline sample (0.2 mg weight) of the spin-gap system YbAl3C3. At
+the base temperature of 0.1 K, several metamagnetic transitions were clearly
+observed for H // c in the range 6 T < H < 9 T whereas only two transitions
+were observed, one at 4.8 T and the other at 6.6 T, for H // a. At fields above
+9 T, the magnetization becomes almost saturated for both H // a and H // c. The
+present results indicate that a singlet-triplet crossover occurs in a
+relatively narrow field range, suggesting a rather weak interdimer interaction
+in spite of the nearly triangular lattice of Yb ions.",1307.3494v1
+2013-08-06,Ion irradiation of Fe-Fe oxide core-shell nanocluster films: Effect of interface on stability of magnetic properties,"A cluster deposition method was used to produce films of loosely aggregated
+nanoclusters (NC) of Fe core-Fe3O4 shell or fully oxidized Fe3O4. Films of
+these NC on Si(100) or MgO(100)/Fe3O4(100) were irradiated to 10^16 Si2+/cm2
+near room temperature using an ion accelerator. Ion irradiation creates
+structural change in the NC film with corresponding chemical and magnetic
+changes which depend on the initial oxidation state of the cluster. Films were
+characterized using magnetometry (hysteresis, first order reversal curves),
+microscopy (transmission electron, helium ion), and x-ray diffraction. In all
+cases, the particle sizes increased due to ion irradiation, and when a core of
+Fe is present, irradiation reduces the oxide shells to lower valent Fe species.
+These results show that ion irradiated behavior of the nanocluster films
+depends strongly on the initial nanostructure and chemistry, but in general
+saturation magnetization decreases slightly.",1308.1384v1
+2013-08-15,Magnetic field generation and amplification in an expanding plasma,"Particle-in-cell simulations are used to investigate the formation of
+magnetic fields, B, in plasmas with perpendicular electron density and
+temperature gradients. For system sizes, L, comparable to the ion skin depth,
+d_i, it is shown that B ~ d_i/L, consistent with the Biermann battery effect.
+However, for large L/d_i, it is found that the Weibel instability (due to
+electron temperature anisotropy) supersedes the Biermann battery as the main
+producer of B. The Weibel-produced fields saturate at a finite amplitude
+(plasma \beta \approx 100), independent of L. The magnetic energy spectra below
+the electron Larmor radius scale is well fitted by power law with slope -16/3,
+as predicted in Schekochihin et al., Astrophys. J. Suppl. Ser 182, 310 (2009).",1308.3421v2
+2014-01-15,Large enhancement of emergent magnetic fields in MnSi with impurities and pressure,"We report a study of the topological Hall effect (THE) in Fe-doped MnSi and
+compare with results from pure MnSi under pressure. We find that Fe doping
+increases the THE, indicating an enhancement of the magnitude of the emergent
+gauge field. This is consistent with the concurrent reduction in the length
+scale of the skyrmion lattice. For both pressurized and doped samples, we
+calculate the emergent magnetic field based on the size of the measured THE,
+and compare it with a theoretical upper-bound. We find that the ratio of these
+two remains more or less constant with pressure or Fe doping, but differs
+greatly from that of pure MnSi at ambient pressure. We discuss the implications
+of this ratio with respect to trends in the saturated magnetic moment and
+helical pitch length as T_C \rightarrow 0 via doping and pressure,
+respectively.",1401.3680v1
+2014-02-04,Observation of the Meissner effect with ultracold atoms in bosonic ladders,"We report on the observation of the Meissner effect in bosonic flux ladders
+of ultracold atoms. Using artificial gauge fields induced by laser-assisted
+tunneling, we realize arrays of decoupled ladder systems that are exposed to a
+uniform magnetic field. By suddenly decoupling the ladders and projecting into
+isolated double wells, we are able to measure the currents on each side of the
+ladder. For large coupling strengths along the rungs of the ladder, we find a
+saturated maximum chiral current corresponding to a full screening of the
+artificial magnetic field. For lower coupling strengths, the chiral current
+decreases in good agreement with expectations of a vortex lattice phase. Our
+work marks the first realization of a low-dimensional Meissner effect and,
+furthermore, it opens the path to exploring interacting particles in low
+dimensions exposed to a uniform magnetic field.",1402.0819v1
+2014-02-05,Innovation of Superparamagnetism in Lead Nanoparticles,"This work reports, some of the features related to the room temperature
+superparamagnetic behaviours of lead nanoparticles. Such behaviours have not
+been discussed elaborately, in any literatures, so far. It is obvious from our
+studies that the superparamagnetic behaviours of Pb nanoparticles are
+surprising behaviours, since bulk Pb has diamagnetic behaviours. Hysteresis
+curve from Vibrating Sample Magnetometer study of Pb nanopowder (metal) serves
+some new observations. The successful calculations of values like magnetic
+size, saturation magnetization, coercive field, and remanent magnetism confirm
+its superparamagnetic nature and explore its potential application in various
+industries. This work throws some light on and helps further research.",1402.1431v1
+2014-04-11,Intense bipolar structures from stratified helical dynamos,"We perform direct numerical simulations of the equations of
+magnetohydrodynamics with external random forcing and in the presence of
+gravity. The domain is divided into two parts: a lower layer where the forcing
+is helical and an upper layer where the helicity of the forcing is zero with a
+smooth transition in between. At early times, a large-scale helical dynamo
+develops in the bottom layer. At later times the dynamo saturates, but the
+vertical magnetic field continues to develop and rises to form dynamic bipolar
+structures at the top, which later disappear and reappear. Some of the
+structures look similar to $\delta$ spots observed in the Sun. This is the
+first example of magnetic flux concentrations, owing to strong density
+stratification, from self-consistent dynamo simulations that generate bipolar,
+super-equipartition strength, magnetic structures whose energy density can
+exceeds the turbulent kinetic energy by even a factor of ten.",1404.3194v2
+2014-04-28,Electronic structure and magnetic properties of L1_0 binary alloys,"We present a systematic study of the magnetic properties of L1$_0$ binary
+alloys FeNi, CoNi, MnAl and MnGa via two different density functional theory
+approaches. Our calculations show large magnetocrystalline anisotropies in the
+order $1~\text{MJ/m}^3$ or higher for CoNi, MnAl and MnGa while FeNi shows a
+somewhat lower value in the range $0.48 - 0.77 ~\text{MJ/m}^3$. Saturation
+magnetization values of $1.3~\text{MA/m}$, $1.0~\text{MA/m}$, $0.8~\text{MA/m}$
+and $0.9~\text{MA/m}$ are obtained for FeNi, CoNi, MnAl and MnGa respectively.
+Curie temperatures are evaluated via Monte Carlo simulations and show
+$T_\text{C}=916~\text{K}$ and $T_\text{C}=1130~\text{K}$ for FeNi and CoNi
+respectively. For Mn-based compounds Mn-rich off-stoichiometric compositions
+are found to be important for the stability of a ferro or ferrimagnetic ground
+state with $T_\text{C}$ greater than $600~\text{K}$. The effect of
+substitutional disorder is studied and found to decrease both
+magnetocrystalline anisotropies and Curie temperatures in FeNi and CoNi.",1404.7097v2
+2014-05-20,Magnetothermodynamics of BPS baby skyrmions,"The magnetothermodynamics of skyrmion type matter described by the gauged BPS
+baby Skyrme model at zero temperature is investigated. We prove that the BPS
+property of the model is preserved also for boundary conditions corresponding
+to an asymptotically constant magnetic field. The BPS bound and the
+corresponding BPS equations saturating the bound are found. Further, we show
+that one may introduce pressure in the gauged model by a redefinition of the
+superpotential. Interestingly, this is related to non-extremal type solutions
+in the so-called fake supersymmetry method. Finally, we compute the equation of
+state of magnetized BSP baby skyrmions inserted into an external constant
+magnetic field $H$ and under external pressure $P$, i.e., $V=V(P,H)$, where $V$
+is the ""volume"" (area) occupied by the skyrmions. We show that the BPS baby
+skyrmions form a ferromagnetic medium.",1405.5215v2
+2014-05-21,Surface twist instabilities and skyrmion states in chiral ferromagnets,"In epitaxial MnSi/Si(111) films, the in-plane magnetization saturation is
+never reached due to the formation of specific surface chiral modulations with
+the propagation direction perpendicular to the film surfaces [Wilson et al.
+Phys. Rev. B 88, 214420 (2013)]. In this paper we show that the occurrence of
+such chiral surface twists is a general effect attributed to all bulk and con-
+fined magnetic crystals lacking inversion symmetry. We present experimental
+investigations of this phenomenon in nanolayers of MnSi/Si(111) supported by
+detailed theoretical analysis within the standard phenomenological model. In
+magnetic nanolayers with intrinsic or induced chirality, such surface induced
+instabilities become sizeable effects and play a crucial role in the formation
+of skyrmion lattices and other nontrivial chiral modulations.",1405.5275v1
+2014-06-18,QCD sum rules for magnetically induced mixing between $η_c$ and $J/ψ$,"We investigate the properties of charmonia in strong magnetic fields by using
+QCD sum rules. We show how to implement the mixing effects between $\eta_c$ and
+$J/\psi$ on the basis of field-theoretical approaches, and then show that the
+sum rules are saturated by the mixing effects with phenomenologically
+determined parameters. Consequently, we find that the mixing effects are the
+dominant contribution to the mass shifts of the charmonia in strong magnetic
+fields.",1406.4586v2
+2014-06-19,Spin-Flop Phenomenon of Two-Dimensional Frustrated Antiferromagnets without Anisotropy in Spin Space,"Motivated by a recent finding of a spin-flop phenomenon in a system without
+anisotropy in spin space reported in the S=1/2 Heisenberg antiferromagnet on
+the square-kagome lattice, we study the S=1/2 Heisenberg antiferromagnets on
+two other lattices composed of vertex-sharing triangles by the numerical
+diagonalization method. One is a novel lattice including a shuriken shape with
+four teeth; the other is the kagome lattice with
+$\sqrt{3}\times\sqrt{3}$-structure distortion, which includes a shuriken shape
+with six teeth. We find in the magnetization processes of these systems that a
+magnetization jump accompanied by a spin-flop phenomenon occurs at the
+higher-field-side edge of the magnetization plateau at one-third the height of
+saturation. This finding indicates that the spin-flop phenomenon found in the
+isotropic system on the square-kagome lattice is not an exceptional case.",1406.4964v1
+2014-06-30,Effect of laser intensity and dynamics of plasma on laser induced breakdown spectroscopy,"Laser-induced breakdown spectroscopy (LIBS) show enhancement in its signal,
+when the laser-induced plasma is confined/decelerated under the effect of an
+external steady magnetic field or in a small cavity. An enhancement in LIBS
+signal has been observed ~2 times in the case of magnetic confinement.
+Combination of magnetic and spatial confinement provide enhancement by an order
+of magnitude. Theoretical analysis of the decelerated plasma has been found in
+agreement with the experimental observations. The enhancement in LIBS signal is
+found dependent on the efficiency of plasma confinement as well as on the time
+duration of laser. The saturation in LIBS signal at higher laser intensity is
+found correlated with electron-ion collision frequency as well as on the
+dynamics and instability of plasma plume. Possibility of further enhancement in
+emission has also been discussed.",1406.7703v1
+2014-07-31,Explaining the Observed Relation Between Stellar Activity and Rotation,"Observations of late-type main-sequence stars have revealed empirical
+scalings of coronal activity versus rotation period or Rossby number $Ro$ (a
+ratio of rotation period to convective turnover time) which has hitherto lacked
+explanation. For $Ro >> 1$, the activity observed as X-ray to bolometric flux
+varies as $Ro^{-q}$ with $2\le q \le 3$, whilst $|q| < 0.12$ for $Ro << 1$.
+Here we explain the transition between these two regimes and the power law in
+the $Ro >> 1$ regime by constructing an expression for the coronal luminosity
+based on dynamo magnetic field generation and magnetic buoyancy. We explain the
+$Ro<<1$ behavior from the inference that observed rotation is correlated with
+internal differential rotation and argue that once the shear time scale is
+shorter than the convective turnover time, eddies will be shredded on the shear
+time scale and so the eddy correlation time actually becomes the shear time and
+the convection time drops out of the equations. We explain the $Ro >> 1$
+behavior using a dynamo saturation theory based on magnetic helicity buildup
+and buoyant loss.",1407.8500v3
+2014-10-18,Magnetoresistance in two-component systems,"Two-component systems with equal concentrations of electrons and holes
+exhibit non-saturating, linear magnetoresistance in classically strong magnetic
+fields. The effect is predicted to occur in finite-size samples at charge
+neutrality in both disorder- and interaction-dominated regimes. The phenomenon
+originates in the excess quasiparticle density developing near the edges of the
+sample due to the compensated Hall effect. The size of the boundary region is
+of the order of the electron-hole recombination length that is inversely
+proportional to the magnetic field. In narrow samples and at strong enough
+magnetic fields, the boundary region dominates over the bulk leading to linear
+magnetoresistance. Our results are relevant for semimetals and narrow-band
+semiconductors including most of the topological insulators.",1410.4982v1
+2014-10-31,Enhanced ferrimagnetism in auxetic NiFe2O4 in the crossover to the ultrathin film limit,"We investigate the sensitive interplay between magnetic, electronic and
+structural properties in the ferrimagnetic oxide NiFe2O4. Emphasis is placed on
+the impact of reduced dimensionality in the crossover from bulk-like to
+ultrathin films. We observed an enhanced saturation magnetization $M_S$ for
+ultrathin NiFe2O4 films on Nb-SrTiO3 (001) substrates that co-occurs with a
+reduced out-of-plane lattice constant under compressive in-plane epitaxial
+strain. We found a bulk-like cationic coordination of the inverse spinel
+lattice independent of the NiFe2O4 film thickness -- thus ruling out a cationic
+inversion that nominally could account for an enhanced $M_S$. Our study instead
+uncovers a reduction of the unit cell volume, i.e. an auxetic behavior in
+ultrathin NiFe2O4 films, which may result in an enhanced magnetic exchange
+caused by an increased interatomic electronic localization.",1410.8782v1
+2014-11-16,Microscopic Model Calculations for the Magnetization Process of Layered Triangular-Lattice Quantum Antiferromagnets,"Magnetization processes of spin-1/2 layered triangular-lattice
+antiferromagnets (TLAFs) under a magnetic field H are studied by means of a
+numerical cluster mean-field method with a scaling scheme. We find that small
+antiferromagnetic couplings between the layers give rise to several types of
+extra quantum phase transitions among different high-field coplanar phases.
+Especially, a field-induced first-order transition is found to occur at
+H\approx 0.7 H_s, where H_s is the saturation field, as another common quantum
+effect of ideal TLAFs in addition to the well-established one-third plateau.
+Our microscopic model calculation with appropriate parameters show excellent
+agreement with experiments on Ba_3CoSb_2O_9 [T. Susuki et al., Phys. Rev. Lett.
+110, 267201 (2013)]. Given this fact, we suggest that the Co^{2+}-based
+compounds may allow for quantum simulations of intriguing properties of this
+simple frustrated model, such as quantum criticality and supersolid states.",1411.4233v2
+2014-12-22,Surface sensitivity of the spin Seebeck effect,"We have investigated the influence of the interface quality on the spin
+Seebeck effect (SSE) of the bilayer system yttrium iron garnet (YIG) - platinum
+(Pt). The magnitude and shape of the SSE is strongly influenced by mechanical
+treatment of the YIG single crystal surface. We observe that the saturation
+magnetic field H_{sat} for the SSE signal increases from 55.3 mT to 72.8 mT
+with mechanical treatment. The change in the magnitude of H_{sat} can be
+attributed to the presence of a perpendicular magnetic anisotropy due to the
+treatment induced surface strain or shape anisotropy in the Pt/YIG system. Our
+results show that the SSE is a powerful tool to investigate magnetic anisotropy
+at the interface.",1412.7712v1
+2015-01-06,Neutron Diffraction Studies on Chemical and Magnetic Structure of Multiferroic PbFe0.67W0.33O3,"We report on the single phase synthesis and room temperature structural
+characterization of PbFe0.67W0.33O3 (PFW) multiferroic. The PFW was synthesized
+by low temperature sintering, Columbite method. Analysis of powder XRD pattern
+exhibits single phase formation of PFW with no traces of pyrochlore phase.
+Detailed analysis of room temperature neutron diffraction (ND) reveals cubic
+phase at room temperature, space group Pm-3m. The ND pattern clearly reveals
+magnetic Bragg peak at 2theeta = 18.51 (Q = 1.36{\AA}-1). The refinement of
+magnetic structure reveals G-type antiferromagnetic structure in PFW at room
+temperature. The dielectric constant and loss tangent decreases with increasing
+frequency. The room temperature P-E measurements shows a non-linear slim
+hysteresis, typical nature of relaxor multiferroics, with saturation and
+remnant polarizations of Ps = 1.50 microC/cm2 and Pr = 0.40 microC/cm2,
+respectively.",1501.01103v1
+2015-01-14,Suppression of 3D-ordering by defects in the $S=1/2$ frustrated chain magnet LiCuVO$_4$,"We report on a heat capacity study of high quality single crystal samples of
+\lcvo\ -- a frustrated spin $S=1/2$ chain system -- in magnetic field amounting
+to 3/4 of the saturation field. At low fields up to about 7~T, a linear
+temperature dependence of the specific heat, $C_p\propto T$, resulting from 1D
+magnetic correlations in the spin chains is followed upon cooling by a sharp
+lambda anomaly of the transition into a 3D helical phase with $C_p\propto T^3$
+behavior at low temperature. The transition from a spin liquid into a
+spin-modulated (SM) phase at higher fields occurs via a hump-like anomaly
+which, as the temperature decreases further turns into a $C_p\propto T^2$ law
+distinctive for a quasi-2D system. We suggest an explanation for how
+nonmagnetic defects in the Cu$^{2+}$ chains can suppress 3D long-range ordering
+in the SM phase and leave it undisturbed in a helical phase.",1501.03226v1
+2015-02-20,Magnetization patterning induced by electrical spin-polarized current in nanostripes,"The combined action of a transverse spin-polarized current and the
+current-induced {\O}rsted field on long ferromagnetic nanostripes is studied
+numerically and analytically. The magnetization behavior is analyzed for
+stripes with various widths and for all range of the applied current density.
+It is established that {\O}rsted field does not destroy periodical
+magnetization structures induced by the spin-torque, e.g. vortex-antivortex
+crystal and cross-tie domain walls. However, the action of the {\O}rsted field
+disables the saturation state for the strong currents: a stationary state with
+a single longitudinal domain wall appears instead. Shape of this wall remains
+constant with the current increasing. The latter phenomenon is studied both
+numerically and analytically.",1502.05885v1
+2015-03-05,Feshbach molecule formation through an oscillating magnetic field: subharmonic resonances,"The conversion of ultracold atoms to molecules via a magnetic Feshbach
+resonance with a sinusoidal modulation of the field is studied. Different
+practical realizations of this method in Bose atomic gases are analyzed. Our
+model incorporates many-body effects through an effective reduction of the
+complete microscopic dynamics. Moreover, we simulate the experimental
+conditions corresponding to the preparation of the system as a thermal gas and
+as a condensate. Some of the experimental findings are clarified. The origin of
+the observed dependence of the production efficiency on the frequency,
+amplitude, and application time of the magnetic modulation is elucidated. Our
+results uncover also the role of the atomic density in the dynamics,
+specifically, in the observed saturation of the atom-molecule conversion
+process.",1503.01700v1
+2015-03-11,Evidence for Half-Metallicity in n-type HgCr2Se4,"High quality HgCr$_2$Se$_4$ single crystals have been investigated by
+magnetization, electron transport and Andreev reflection spectroscopy. In the
+ferromagnetic ground state, the saturation magnetic moment of each unit cell
+corresponds to an integer number of electron spins (3 $\mu_B$/Cr$^{3+}$), and
+the Hall effect measurements suggest n-type charge carriers. Spin polarizations
+as high as $97\%$ were obtained from fits of the differential conductance
+spectra of HgCr$_2$Se$_4$/Pb junctions with the modified
+Blonder-Tinkham-Klapwijk (BTK) theory. The temperature and bias-voltage
+dependencies of the sub-gap conductance are consistent with recent theoretical
+calculations based on spin active scatterings at a superconductor/half metal
+interface. Our results suggest that n-HgCr$_2$Se$_4$ is a half metal, in
+agreement with theoretical calculations that also predict undoped
+HgCr$_2$Se$_4$ is a magnetic Weyl semimetal.",1503.03190v3
+2015-03-12,"Shubnikov-de Haas oscillations, weak antilocalization effect and large linear magnetoresistance in the putative topological superconductor LuPdBi","We present electronic transport and magnetic properties of single crystals of
+semimetallic half-Heusler phase LuPdBi, having theoretically predicted band
+inversion requisite for nontrivial topological properties. The compound
+exhibits superconductivity below a critical temperature $T_{\rm c}=1.8\,$K,
+with a zero-temperature upper critical field $B_{\rm c2}\approx2.3\,$T.
+Although superconducting state is clearly reflected in the electrical
+resistivity and magnetic susceptibility data, no corresponding anomaly can be
+seen in the specific heat. Temperature dependence of the electrical resistivity
+suggests existence of two parallel conduction channels: metallic and
+semiconducting, with the latter making negligible contribution at low
+temperatures. The magnetoresistance is huge and clearly shows a weak
+antilocalization effect in small magnetic fields. Above about 1.5 T, the
+magnetoresistance becomes linear and does not saturate in fields up to 9 T. The
+linear magnetoresistance is observed up to room temperature. Below 10 K, it is
+accompanied by Shubnikov-de Haas oscillations. Their analysis reveals charge
+carriers with effective mass of $0.06\,m_e$ and a Berry phase very close to
+$\pi$, expected for Dirac-fermion surface states, thus corroborating
+topological nature of the material.",1503.03697v1
+2015-03-19,Anomalous magnetization of $S$=2 ferromagnetic-antiferromagnetic alternating chain with Ising anisotropy,"We present the first experimental realization of an $S=2$
+ferromagnetic-antiferromagnetic (F-AF) alternating chain in a new Mn-verdazyl
+complex [Mn(hfac)$_2$]$\cdot$($o$-Py-V)
+[hfac=1,1,1,5,5,5-hexafluoroacetylacetonate;
+$o$-Py-V=3-(2-pyridyl)-1,5-diphenylverdazyl]. Through the $ab$ $initio$
+molecular orbital calculation, magnetization, and ESR measurements, this
+compound is confirmed to form an $S=2$ F-AF alternating chain with Ising
+anisotropy below about 100 K. Furthermore, we find an anomalous change in
+magnetization at 1/4 of the saturation value, which is probably a manifestation
+of the quantum nature of the system.",1503.05633v1
+2015-05-20,Effect of Transverse Magnetic Field on Dynamics of Current Driven Domain Wall Motion in the Presence of Spin-Hall Effect,"Theoretically, we study the dynamics of a current induced domain wall in the
+bi-layer structure consists of a ferromagnetic layer and a non-magnetic metal
+layer with strong spin-orbit coupling in the presence of spin-Hall effect. The
+analytical expressions for the velocity and width of the domain wall interms of
+excitation angle are obtained by solving the Landau-Lifshitz-Gilbert equation
+with adiabatic, nonadiabatic and spin Hall effect-spin transfer torques using
+Schryers and Walker's method. Numerical results show that the occurance of
+polarity switching in the domain wall is observed only above the threshold
+current density. The presence of transverse magnetic field along with spin Hall
+effect-spin transfer torque enchances the value of the threshold current
+density, and the corresponding saturated velocity at the threshold current
+density is also increased.",1505.05249v1
+2015-06-05,Broad universal Feshbach resonances in the chaotic spectrum of Dysprosium atoms,"We report on the observation of weakly-bound dimers of bosonic Dysprosium
+with a strong universal s-wave halo character, associated with broad magnetic
+Feshbach resonances. These states surprisingly decouple from the chaotic
+backgound of narrow resonances, persisting across many such narrow resonances.
+In addition they show the highest reported magnetic moment
+$\mu\simeq20\,\mu_{\rm B}$ of any ultracold molecule. We analyze our findings
+using a coupled-channel theory taking into account the short range van der
+Waals interaction and a correction due to the strong dipole moment of
+Dysprosium. We are able to extract the scattering length as a function of
+magnetic field associated with these resonances and obtain a background
+scattering length $a_{\rm bg}=91(16)\,a_0$. These results offer prospects of a
+tunability of the interactions in Dysprosium, which we illustrate by observing
+the saturation of three-body losses.",1506.01875v2
+2015-06-16,Approaching magnetic ordering in graphene materials by FeCl$_3$ intercalation,"We show the successful intercalation of large area (1 cm$^2$) epitaxial
+few-layer graphene grown on 4H-SiC with FeCl$_3$. Upon intercalation the
+resistivity of this system drops from an average value of $\approx 200 \
+\Omega/sq$ to $\approx 16 \ \Omega/sq$ at room temperature. The
+magneto-conductance shows a weak localization feature with a temperature
+dependence typical of graphene Dirac fermions demonstrating the decoupling into
+parallel hole gases of each carbon layer composing the FeCl$_3$ intercalated
+structure. The phase coherence length ($\approx 1.2 \mu$m at 280 mK) decreases
+rapidly only for temperatures higher than the 2-D magnetic ordering in the
+intercalant layer while it tends to saturate for temperatures lower than the
+antiferromagnetic ordering between the planes of FeCl$_3$ molecules providing
+the first evidence for magnetic ordering in the extreme two-dimensional limit
+of graphene.",1506.04959v1
+2015-07-23,Theory of nuclear spin dephasing and relaxation by optically illuminated nitrogen-vancy center,"Dephasing and relaxation of the nuclear spins coupled to the nitrogen-vacancy
+(NV) center during optical initialization and readout is an important issue for
+various applications of this hybrid quantum register. Here we present both an
+analytical description and a numerical simulation for this process, which agree
+reasonably with the experimental measurements. For the NV center under cyclic
+optical transition, our analytical formula not only provide a clear physics
+picture, but also allows controlling the nuclear spin dissipation by tuning an
+external magnetic field. For more general optical pumping, our analytical
+formula reveals significant contribution to the nuclear spin dissipation due to
+electron random hopping into/out of the $m=0$ (or $m=\pm1$) subspace. This
+contribution is not suppressed even under saturated optical pumping and/or
+vanishing magnetic field, thus providing a possible solution to the puzzling
+observation of nuclear spin dephasing in zero perpendicular magnetic field [M.
+V. G. Dutt \textit{et al}., Science \textbf{316}, 1312 (2007)]. It also implies
+that enhancing the degree of spin polarization of the nitrogen-vacancy center
+can reduce the effect of optical induced nuclear spin dissipation.",1507.06385v1
+2015-07-30,Magnetic Field Amplification via Protostellar Disc Dynamos,"We numerically investigate the generation of a magnetic field in a
+protostellar disc via an $\alpha \Omega$-dynamo and the resulting
+magnetohydrodynamic (MHD) driven outflows. We find that for small values of the
+dimensionless dynamo parameter $\alpha_d$ the poloidal field grows
+exponentially at a rate $\sigma \propto \Omega_K \sqrt{\alpha_d}$, before
+saturating to a value $\propto \sqrt{\alpha_d}$. The dynamo excites dipole and
+octupole modes, but quadrupole modes are suppressed, because of the symmetries
+of the seed field. Initial seed fields too weak to launch MHD outflows are
+found to grow sufficiently to launch winds with observationally relevant mass
+fluxes of order $10^{-9} M_{\odot}/\rm{yr}$ for T Tauri stars. This suggests
+$\alpha \Omega$-dynamos may be responsible for generating magnetic fields
+strong enough to launch observed outflows.",1507.08702v2
+2015-11-05,Size effect on the hysteresis characteristics of a system of interacting core/shell nanoparticles,"We have developed a model for the interacting ore/shell nanoparticles, which
+we used to analyze the dependence of the coercive field Hc, the remanent
+saturation magnetization Mrs and the satu- ration magnetization Ms on the
+interfacial exchange interaction between the core and the shell, the size of
+the nanoparticles and their interaction for Fe/Fe3O4 nanoparticles have been
+carried out. It has been shown that the hysteresis characteristics increase
+together with the size of nanoparticles. Hc and Mrs are changing nonmonotonic
+when the constant interfacial exchange interaction changes from negative to
+positive values. In the system of core/shell nanoparticles, magnetic
+interaction results in Hc and Mrs dropping, which was conformed by experiments.
+Usage: Secondary publications and information retrieval purposes.",1511.01617v1
+2016-03-15,Highly Sensitive On-Chip Magnetometer with Saturable Absorbers in Two-Color Microcavities,"Interacting resonators can lead to strong non-linearities but the details can
+be complicated to predict. In this work, we study the non-linearities
+introduced by two nested microcavities that interact with nitrogen vacancy
+centers in a diamond waveguide. Each cavity has differently designed resonance;
+one in the green and one in the infrared. The magnetic-field dependence of the
+nitrogen vacancy center absorption rates on the green and the recently observed
+infrared transitions allows us to propose a scalable on-chip magnetometer that
+combines high magnetic-field sensitivity and micrometer spatial resolution. By
+investigating the system behaviors over several intrinsic and extrinsic
+parameters, we explain the main non-linearities induced by the NV centers and
+enhanced by the cavities. We finally show that the cavities can improve the
+magnetic-field sensitivity by up to two orders of magnitudes.",1603.04529v1
+2016-04-06,Numerical simulations of Kelvin-Helmholtz instability: a two-dimensional parametric study,"Using two-dimensional simulations, we numerically explore the dependences of
+Kelvin-Helmholtz instability upon various physical parameters, including
+viscosity, width of sheared layer, flow speed, and magnetic field strength. In
+most cases, a multi-vortex phase exists between the initial growth phase and
+final single-vortex phase. The parametric study shows that the evolutionary
+properties, such as phase duration and vortex dynamics, are generally sensitive
+to these parameters except in certain regimes. An interesting result is that
+for supersonic flows, the phase durations and saturation of velocity growth
+approach constant values asymptotically as the sonic Mach number increases. We
+confirm that the linear coupling between magnetic field and Kelvin-Helmholtz
+modes is negligible if the magnetic field is weak enough. The morphological
+behaviour suggests that the multi-vortex coalescence might be driven by the
+underlying wave-wave interaction. Based on these results, we make a preliminary
+discussion about several events observed in the solar corona. The numerical
+models need to be further improved to make a practical diagnostic of the
+coronal plasma properties.",1604.01546v1
+2016-05-01,Numerical study of the Transverse Diffusion coefficient for a one component model of a plasma,"We report the results of MD numerical simulations for a one component model
+of a plasma in the weakly coupled regime, at different values of temperature
+$T$ and applied magnetic field $\vec B$, in which the diffusion coefficient
+$D_{\perp}$ transverse to the field is estimated. We find that there exists a
+threshold in temperature, at which an inversion occurs, namely, for $T$ above
+the threshold the diffusion coefficient $D_{\perp}$ starts decreasing as $T$
+increases. This is at variance with the behavior predicted by the Bohm law
+$D_{\perp}\sim T/B$, which actually holds below the threshold. In addition we
+find that, for temperatures above such a threshold, another transition occurs,
+now with respect to the values of the magnetic field: for weak magnetic fields
+the diffusion coefficients scales as $1/B^2$, in agreement with the predictions
+of the standard kinetics theory, while it apparently saturates when the field
+strength is sufficiently increased.",1605.00235v1
+2016-05-03,T/B scaling without quasiparticle mass divergence: YbCo2Ge4,"YbCo$_2$Ge$_4$ is a clean paramagnetic Kondo lattice which displays non-Fermi
+liquid behavior. We report a detailed investigation of the specific heat,
+magnetic Gr\""uneisen parameter ($\Gamma_{\rm mag}$) and temperature derivative
+of the magnetization ($M$) on a high-quality single crystal at temperatures
+down to $0.1$~K and magnetic fields up to 7~T. $\Gamma_{\rm mag}$ and $dM/dT$
+display a divergence upon cooling and obey $T/B$ scaling. Similar behavior has
+previously been found in several other Yb-based Kondo lattices and related to a
+zero-field quantum critical point without fine tuning of pressure or
+composition. However, in the approach of $B\rightarrow 0$ the electronic heat
+capacity coefficient of YbCo$_2$Ge$_4$ saturates at low $T$, excluding
+ferromagnetic quantum criticality. This indicates that $T/B$ scaling is
+insufficient to prove a zero-field quantum critical point.",1605.00896v2
+2016-05-06,"Exchange-mediated, non-linear, out-of-plane magnetic field dependence of the ferromagnetic vortex gyrotropic mode frequency driven by core deformation","We have performed micromagnetic simulations of the vortex gyrotropic mode
+resonance in a range of disk geometries subject to spatially uniform
+out-of-plane magnetic fields. For disks of small lateral dimensions, we observe
+a drop-off in the mode's frequency for field amplitudes approaching the disk
+saturation field. This non-linear frequency response is shown to be associated
+with an increased vortex core deformation, which results from the demagnetizing
+field created when the core is shifted laterally. Such deformation results in
+an increase in the average out-of-plane magnetization of the displaced vortex
+state, which through an exchange contribution, leads to a sharp decrease in the
+vortex stiffness coefficient. It is this decrease in the vortex stiffness
+coefficient which leads to the non-linear field dependence of the gyrotropic
+mode frequency.",1605.01830v1
+2016-06-13,Electronic Transport on the Shastry-Sutherland Lattice in Ising-type Rare Earth Tetraborides,"In the presence of a magnetic field frustrated spin systems may exhibit
+plateaus at fractional values of saturation magnetization. Such plateau states
+are stabilized by classical and quantum mechanisms including order-by-disorder,
+triplon crystallization, and various competing order effects. In the case of
+electrically conducting systems, free electrons represent an incisive probe for
+the plateau states. Here we study the electrical transport of Ising-type rare
+earth tetraborides $R$B$_4$ ($R=$Er, Tm), a metallic Shastry-Sutherland lattice
+showing magnetization plateaus. We find that the longitudinal and transverse
+resistivities reflect scattering with both the static and dynamic plateau
+structure. We model these results consistently with the expected strong
+uniaxial anisotropy in a quantitative level, providing a framework for the
+study of plateau states in metallic frustrated systems.",1606.04003v2
+2016-08-03,An analytical dynamo solution for large-scale magnetic fields of galaxies,"We present an effectively global analytical asymptotic galactic dynamo
+solution for the regular magnetic field of an axisymmetric thin disc in the
+saturated state. This solution is constructed by combining two well-known types
+of local galactic dynamo solution, parameterized by the disc radius. Namely,
+the critical (zero growth) solution obtained by treating the dynamo equation as
+a perturbed diffusion equation is normalized using a non-linear solution that
+makes use of the `no-$z$' approximation and the dynamical $\alpha$-quenching
+non-linearity. This overall solution is found to be reasonably accurate when
+compared with detailed numerical solutions. It is thus potentially useful as a
+tool for predicting observational signatures of magnetic fields of galaxies. In
+particular, such solutions could be painted onto galaxies in cosmological
+simulations to enable the construction of synthetic polarized synchrotron and
+Faraday rotation measure (RM) datasets. Further, we explore the properties of
+our numerical solutions, and their dependence on certain parameter values. We
+illustrate and assess the degree to which numerical solutions based on various
+levels of approximation, common in the dynamo literature, agree with one
+another.",1608.01119v3
+2016-08-31,Stagnation of electron flow by a nonlinearly generated whistler wave,"Relativistic electron beam transport through a high-density, magnetized
+plasma is studied numerically and theoretically. An electron beam injected into
+a cold plasma excites Weibel and two-stream instabilities that heat the beam
+and saturate. In the absence of an applied magnetic field, the heated beam
+continues to propagate. However, when a magnetic field of particular strength
+is applied along the direction of beam propagation, a secondary instability of
+off-angle whistler modes is excited. These modes then couple nonlinearly
+creating a large amplitude parallel propagating whistler that stops the beam.
+In this letter, we will show the phenomena in detail and explain the mechanism
+of whistler mediated beam stagnation.",1608.08867v1
+2016-09-14,Rashba-Edelstein Magnetoresistance in Metallic Heterostructure,"We report the observation of magnetoresistance originating from Rashba
+spin-orbit coupling (SOC) in a metallic heterostructure: the Rashba-Edelstein
+(RE) magnetoresistance. We show that the simultaneous action of the direct and
+inverse RE effects in a Bi/Ag/CoFeB trilayer couples current-induced spin
+accumulation to the electric resistance. The electric resistance changes with
+the magnetic-field angle, reminiscent of the spin Hall magnetoresistance,
+despite the fact that bulk SOC is not responsible for the magnetoresistance. We
+further found that, even when the magnetization is saturated, the resistance
+increases with increasing the magnetic-field strength, which is attributed to
+the Hanle magnetoresistance in this system.",1609.04122v1
+2016-10-11,Semiclassical analysis of a magnetization plateau in a 2D frustrated ferrimagnet,"We use a semiclassical large-$S$ expansion to study a plateau at $1/3$
+saturation in the magnetization curve of a frustrated ferrimagnet on a
+spatially anisotropic kagom\'{e} lattice. The spins have both ferromagnetic and
+antiferromagnetic nearest-neighbor Heisenberg couplings, and a frustrating
+next-nearest-neighbor coupling in one lattice direction. The magnetization
+plateau appears at the classical level for a certain range of couplings, and
+quantum fluctuations significantly broaden it at both ends. Near the region of
+the phase diagram where the classical plateau destabilizes, we find an exotic
+""chiral liquid"" phase that preserves translational and $U(1)$ spin symmetry, in
+which bound pairs of magnons with opposite spins are condensed. We show how
+this state is obtained naturally from a relativistic field theory formulation.
+We comment on the relevance of the model to the material
+$\text{Cu}_3\text{V}_2\text{O}_7\text{(OH)}_2 \cdot 2\text{H}_2\text{O}$
+(volborthite).",1610.03135v3
+2016-11-01,Magnetoelectric Behavior from $S=1/2$ Asymmetric Square Cupolas,"Magnetoelectric properties are studied by a combined experimental and
+theoretical study of a quasi-two-dimensional material composed of square
+cupolas, Ba(TiO)Cu$_4$(PO$_4$)$_4$. The magnetization is measured up to above
+the saturation field, and several anomalies are observed depending on the field
+directions. We propose a $S$=1/2 spin model with Dzyaloshinskii-Moriya
+interactions, which well reproduces the full magnetization curves. Elaborating
+the phase diagram of the model, we show that the anomalies are explained by
+magnetoelectric phase transitions. Our theory also accounts for the scaling of
+the dielectric anomaly observed in experiments. The results elucidate the
+crucial role of the in-plane component of Dzyaloshinskii-Moriya interactions,
+which is induced by the noncoplanar buckling of square cupola. We also predict
+a `hidden' phase and another magnetoelectric response both of which appear in
+nonzero magnetic field.",1611.00086v1
+2016-12-13,Gyrofluid computation of magnetic perturbation effects on turbulence and edge localized bursts,"The effects of non-axisymmetric resonant magnetic perturbation fields (RMPs)
+on saturated drift-wave turbulence and on ballooning mode bursts in the edge
+pedestal of tokamak plasmas are investigated by numerical simulations with a
+nonlinear six-moment electromagnetic gyrofluid model including zonal profile
+evolution. The vacuum RMP fields are screened by plasma response currents, so
+that magnetic transport by perturbed parallel motion is not significantly
+changed. Radial transport of both particles and heat is dominated by turbulent
+convection even for large RMP amplitudes, where formation of stationary
+convective structures leads to edge profile degradation. Modelling of ideal
+ballooning mode unstable edge profiles for single bursts including RMP fields
+causes resonant mode locking and destabilization.",1612.04121v1
+2017-01-26,Frustrated honeycomb-lattice bilayer quantum antiferromagnet in a magnetic field: Unconventional phase transitions in a two-dimensional isotropic Heisenberg model,"We consider the spin-1/2 antiferromagnetic Heisenberg model on a bilayer
+honeycomb lattice including interlayer frustration in the presence of an
+external magnetic field. In the vicinity of the saturation field, we map the
+low-energy states of this quantum system onto the spatial configurations of
+hard hexagons on a honeycomb lattice. As a result, we can construct effective
+classical models (lattice-gas as well as Ising models) on the honeycomb lattice
+to calculate the properties of the frustrated quantum Heisenberg spin system in
+the low-temperature regime. We perform classical Monte Carlo simulations for a
+hard-hexagon model and adopt known results for an Ising model to discuss the
+finite-temperature order-disorder phase transition that is driven by a magnetic
+field at low temperatures. We also discuss an effective-model description
+around the ideal frustration case and find indications for a spin-flop like
+transition in the considered isotropic spin model.",1701.07876v1
+2017-01-27,A unified description of collective magnetic excitations,"In this work, we define a set of analytic tools to describe the dynamic
+response of the magnetization to small perturbations, which can be used on its
+own or in combination with micromagnetic simulations and does not require
+saturation. We present a general analytic description of the ferromagnetic high
+frequency susceptibility tensor to describe angular as well as frequency
+dependent ferromagnetic resonance spectra and account for asymmetries in the
+line shape. Furthermore, we expand this model to reciprocal space and show how
+it describes the magnon dispersion. Finally we suggest a trajectory dependent
+solving tool to describe the equilibrium states of the magnetization.",1701.09078v2
+2017-02-21,"Back hopping in spin-transfer-torque devices, possible origin and counter measures","The effect of undesirable high-frequency free-layer switching in magnetic
+multilayer systems, referred to as back hopping, is investigated by means of
+the spin-diffusion model. A possible origin of the back-hopping effect is found
+to be the destabilization of the pinned layer which leads to perpetual
+switching of both layers. The influence of different material parameters on the
+critical switching currents for the free and pinned layer is obtained by
+micromagnetic simulations. It is found that the choice of a free-layer material
+with low polarization $\beta$ and saturation magnetization $M_s$, and a
+pinned-layer material with high $\beta$ and $M_s$ leads to a low free-layer
+critical current and a high pinned-layer critical current and hence reduces the
+likelihood of back hopping. While back hopping was observed in various types of
+devices, there are only few experiments that exhibit this effect in
+perpendicularly magnetized systems. However, our simulations suggest, that this
+is likely to change due to loss of pinned-layer anisotropy when decreasing
+device sizes.",1702.06604v3
+2017-03-16,All-Angle Collimation for Spin Waves,"We studied the effect of collimation for monochromatic beams of spin waves,
+resulting from the refraction at the interface separating two magnetic
+half-planes. The collimation was observed in broad range of the angles of
+ncidence for homogenous Co and Py half-planes, due to significant intrinsic
+anisotropy of spin wave propagation in these materials. The effect exists for
+the sample saturated by in plane magnetic field tangential to the interface.
+The collimation for all possible angles of incidence was found in the system
+where the incident spin wave is refracted on the interface between homogeneous
+and periodically patterned layers of YIG. The refraction was investigated by
+the analysis of isofrequency dispersion contours of both pairs materials, i.e.,
+uniform YIG/patterned YIG and Co/Py, which are calculated with the aid of the
+plane wave method. Besides, the refraction in Co/Py system was studied using
+micromagnetic simulations.",1703.05548v1
+2017-03-16,"Magnetic properties, domain wall creep motion and the Dzyaloshinskii-Moriya interaction in Pt/Co/Ir thin films","We study the magnetic properties of perpendicularly magnetised Pt/Co/Ir thin
+films and investigate the domain wall creep method of determining the
+interfacial Dzyaloshinskii-Moriya (DM) interaction in ultra-thin films.
+Measurements of the Co layer thickness dependence of saturation magnetisation,
+perpendicular magnetic anisotropy, and symmetric and antisymmetric (i.e. DM)
+exchange energies in Pt/Co/Ir thin films have been made to determine the
+relationship between these properties. We discuss the measurement of the DM
+interaction by the expansion of a reverse domain in the domain wall creep
+regime. We show how the creep parameters behave as a function of in-plane bias
+field and discuss the effects of domain wall roughness on the measurement of
+the DM interaction by domain expansion. Whereas modifications to the creep law
+with DM field and in-plane bias fields have taken into account changes in the
+energy barrier scaling parameter $\alpha$, we find that both $\alpha$ and the
+velocity scaling parameter $v_{0}$ change as a function of in-plane bias field.",1703.05749v2
+2017-04-05,The interfacial nature of proximity induced magnetism and the Dzyaloshinskii-Moriya interaction at the Pt/Co interface,"The Dzyaloshinskii-Moriya interaction (DMI) has been shown to stabilise
+Ne\'{e}l domain walls in magnetic thin films, allowing high domain wall
+velocities driven by spin current effects. DMI occurs at the interface between
+ferromagnetic and heavy metal layers with strong spin-orbit coupling, but
+details of the interaction remain to be understood and the role of proximity
+induced magnetism (PIM) in the heavy metal is unknown. We report interfacial
+DMI and PIM in Pt determined as a function of Au and Ir spacer layers in
+Pt/Co/Au,Ir/Pt. The length-scale for both interactions is sensitive to
+sub-nanometre changes in the spacer thickness, and they correlate over sub
+mono-layer spacer thicknesses, but not for thicker spacers. The spacer layer
+thickness dependence of the Pt PIM for both Au and Ir shows a rapid monotonic
+decay, while the DMI changes rapidly but has a two-step approach to saturation
+and continues to change, even after the PIM is lost.",1704.01338v1
+2017-04-18,The electronic structure and magnetic phase transition of hexagonal FeSe thin films studied by photoemission spectroscopy,"Hexagonal FeSe thin films were grown on SrTiO3 substrates and the temperature
+and thickness dependence of their electronic structures were studied. The
+hexagonal FeSe is found to be metallic and electron doped, whose Fermi surface
+consists of six elliptical electron pockets. With decreased temperature, parts
+of the bands shift downward to high binding energy while some bands shift
+upwards to EF. The shifts of these bands begin around 300 K and saturate at low
+temperature, indicating a magnetic phase transition temperature of about 300 K.
+With increased film thickness, the Fermi surface topology and band structure
+show no obvious change except some minor quantum size effect. Our paper reports
+the first electronic structure of hexagonal FeSe, and shows that the possible
+magnetic transition is driven by large scale electronic structure
+reconstruction.",1704.05177v2
+2017-04-30,Angular Dependent Magnetization Dynamics of Kagome Artificial Spin Ice Incorporating Topological Defects,"We report angular-dependent spin-wave spectroscopy on kagome artificial spin
+ice made of large arrays of interconnected Ni80Fe20 nanobars. Spectra taken in
+saturated and disordered states exhibit a series of resonances with
+characteristic in-plane angular dependencies. Micromagnetic simulations allow
+us to interpret characteristic resonances of a two-step magnetization reversal
+of the nanomagnets. The dynamic properties are consistent with topological
+defects that are provoked via a magnetic field applied at specific angles.
+Simulations that we performed on previously investigated kagome artificial spin
+ice consisting of isolated nanobars show characteristic discrepancies in the
+spin wave modes which we explain by the absence of vertices.",1705.00270v1
+2017-05-02,Strongly interaction-enhanced valley magnetic response in monolayer WSe2,"Coulomb interaction between electrons lies at the heart of magnetism in
+solids. In contrast to conventional two-dimensional (2D) systems, electrons in
+monolayer transition metal dichalcogenides (TMDs) possess coupled spin and
+valley degrees of freedom by the spin-orbit interaction. The electrons are also
+strongly interacting even in the high-density regime because of the weak
+dielectric screening in two dimensions and a large band mass. The combination
+of these properties presents a unique platform for exploring spin and valley
+magnetism in 2D electron liquids. Here we report an observation by
+magneto-photoluminescence spectroscopy of a nonlinear valley Zeeman effect,
+correlated with an over fourfold enhancement in the exciton g-factor in
+monolayer WSe2. The effect occurs when the Fermi level crosses the spin-split
+upper conduction band, corresponding to a change of the spin-valley degeneracy
+from 2 to 4. The enhancement increases, shows no sign of saturation as the
+sample temperature decreases. Our result suggests the possibility of rich
+many-body ground states in monolayer TMDs with multiple internal degrees of
+freedom.",1705.01078v1
+2017-05-09,The relation between color spaces and compositional data analysis demonstrated with magnetic resonance image processing applications,"This paper presents a novel application of compositional data analysis
+methods in the context of color image processing. A vector decomposition method
+is proposed to reveal compositional components of any vector with positive
+components followed by compositional data analysis to demonstrate the relation
+between color space concepts such as hue and saturation to their compositional
+counterparts. The proposed methods are applied to a magnetic resonance imaging
+dataset acquired from a living human brain and a digital color photograph to
+perform image fusion. Potential future applications in magnetic resonance
+imaging are mentioned and the benefits/disadvantages of the proposed methods
+are discussed in terms of color image processing.",1705.03457v4
+2017-05-11,Itinerant G-type antiferromagnetic order in SrCr$_2$As$_2$,"Neutron diffraction and magnetic susceptibility studies of a polycrystalline
+SrCr$_2$As$_2$ sample reveal that this compound is an itinerant G-type
+antiferromagnet below the N${\rm \acute{e}}$el temperature $T_{\textrm N}$ =
+590(5) K with the Cr magnetic moments aligned along the tetragonal $c$ axis.
+The system remains tetragonal to the lowest measured temperature ($\sim$12 K).
+The lattice parameter ratio $c/a$ and the magnetic moment saturate at about the
+same temperature below $\sim$ 200 K, indicating a possible magnetoelastic
+coupling. The ordered moment, $\mu=1.9(1)~\mu_{\rm B}$/Cr, measured at $T = 12$
+K, is significantly reduced compared to its localized value ($4~\mu_{\rm
+B}$/Cr) due to the itinerant character brought about by the hybridization
+between the Cr $3d$ and As $4p$ orbitals.",1705.04246v1
+2017-06-19,"Large, nonsaturating thermopower in a quantizing magnetic field","The thermoelectric effect is the generation of an electrical voltage from a
+temperature gradient in a solid material due to the diffusion of free charge
+carriers from hot to cold. Identifying materials with large thermoelectric
+response is crucial for the development of novel electric generators and
+coolers. In this paper we consider theoretically the thermopower of Dirac/Weyl
+semimetals subjected to a quantizing magnetic field. We contrast their
+thermoelectric properties with those of traditional heavily-doped
+semiconductors and we show that, under a sufficiently large magnetic field, the
+thermopower of Dirac/Weyl semimetals grows linearly with the field without
+saturation and can reach extremely high values. Our results suggest an
+immediate pathway for achieving record-high thermopower and thermoelectric
+figure of merit, and they compare well with a recent experiment on
+Pb$_{1-x}$Sn$_x$Se.",1706.06117v2
+2017-07-06,Multi-Q mesoscale magnetism in CeAuSb$_2$,"We report the discovery of a field driven transition from a striped to woven
+Spin Density Wave (SDW) in the tetragonal heavy fermion compound CeAuSb$_2$.
+Polarized along $\bf c$, the sinusoidal SDW amplitude is 1.8(2) $\mu_B$/Ce for
+$T \ll T_N$=6.25(10) K with wavevector ${\bf q}_{1}=( \eta, \eta, \frac{1}{2}
+)$ ($\eta=0.136(2)$). For ${\bf H}\parallel{\bf c}$, harmonics appearing at
+$2{\bf q}_{1}$ evidence a striped magnetic texture below $\mu_\circ
+H_{c1}=2.78(1)$ T. Above $H_{c1}$, these are replaced by woven harmonics at
+${\bf q}_{1}+{\bf q}_2=(2\eta, 0, 0)+{\bf c}^*$ until $\mu_\circ
+H_{c2}=5.42(5)$ T, where satellites vanish and magnetization non-linearly
+approaches saturation at 1.64(2) $\mu_B$/Ce for $\mu_\circ H\approx 7$ T.",1707.01611v1
+2017-07-25,Linarite - a quasi-critical J$_1$-J$_2$ chain,"The mineral linarite, PbCuSO$_4$(OH)$_2$, is a spin 1/2 chain with
+frustrating nearest neighbor ferromagnetic and next-nearest neighbor
+antiferromagnetic exchange interactions. Our inelastic neutron scattering
+experiments performed above the saturation field establish that the ratio
+between these exchanges is such that linarite is extremely close to the quantum
+critical point between spin-multipolar phases and the ferromagnetic state.
+However, the measured complex magnetic phase diagram depends strongly on the
+magnetic field direction. The field-dependent phase sequence is explained by
+our classical simulations of a nearly critical model with tiny orthorhombic
+exchange anisotropy. The simulations also capture qualitatively the measured
+variations of the wave vector as well as the staggered and the uniform
+magnetizations in an applied field.",1707.08051v1
+2017-08-29,"Structural, magnetic, and electronic properties of GdTiO3 Mott insulator thin films grown by pulsed laser deposition","We report on the optimization process to synthesize epitaxial thin films of
+GdTiO3 on SrLaGaO4 substrates by pulsed laser deposition. Optimized films are
+free of impurity phases and are fully strained. They possess a magnetic Curie
+temperature TC = 31.8 K with a saturation magnetization of 4.2 muB per formula
+unit at 10 K. Transport measurements reveal an insulating response, as
+expected. Optical spectroscopy indicates a band gap of 0.7 eV, comparable to
+the bulk value. Our work adds ferrimagnetic orthotitanates to the palette of
+perovskite materials for the design of emergent strongly correlated states at
+oxide interfaces using a versatile growth technique such as pulsed laser
+deposition.",1708.08785v1
+2018-01-17,Hartman effect for spin waves in exchange regime,"Hartman effect for spin waves tunnelling through a barrier in a thin magnetic
+film is considered theoretically. The barrier is assumed to be created by a
+locally increased magnetic anisotropy field. The considerations are focused on
+a nanoscale system operating in the exchange-dominated regime. We derive the
+formula for group delay $\tau_{gr}$ of spin wave package and show that
+$\tau_{gr}$ saturates with increasing barrier width, which is a signature of
+the Hartman effect predicted earlier for photonic and electronic systems. In
+our calculations we consider the general boundary exchange conditions which
+take into account different strength of exchange coupling between the barrier
+and its surrounding. As a system suitable for experimental observation of the
+Hartman effect we propose a CoFeB layer with perpendicular magnetic anisotropy
+induced by a MgO overlayer.",1801.05876v3
+2018-05-24,Disruption of current filaments and isotropization of magnetic field in counter-streaming plasmas,"We study the stability of current filaments produced by the Weibel, or
+current filamentation, instability in weakly magnetized counter-streaming
+plasmas. It is shown that a resonance exists between the current-carrying ions
+and a longitudinal drift-kink mode that strongly deforms and eventually breaks
+the current filaments. Analytical estimates of the wavelength, growth rate and
+saturation level of the resonant mode are derived and validated by
+three-dimensional particle-in-cell simulations. Furthermore, self-consistent
+simulations of counter-streaming plasmas indicate that this drift-kink mode is
+dominant in the slow down of the flows and in the isotropization of the
+magnetic field, playing an important role in the formation of collisionless
+shocks.",1805.09814v1
+2018-08-17,Director switching dynamics of ferromagnetic nematic liquid crystals,"Successful realization of ferromagnetic nematic liquid crystals has opened up
+the possibility to experimentally study a completely new set of fundamental
+physical phenomena. In this contribution we present a detailed investigation of
+some aspects of the static response and the complex dynamics of ferromagnetic
+liquid crystals under the application of an external magnetic field.
+Experimental results are then compared with a macroscopic model. Dynamics of
+the director were measured by optical methods and analyzed in terms of a
+theoretical macroscopic model. A dissipative cross-coupling coefficient
+describing the dynamic coupling between the two system order parameters, the
+magnetization and the nematic director, is needed to explain the results. In
+this contribution we examine the dependency of this coefficient on material
+parameters and the saturation magnetization and the liquid crystal host.
+Despite the complexity of the system, the theoretical description allows for a
+proper interpretation of the results and is connected to several microscopic
+aspects of the colloidal suspension.",1808.05843v1
+2019-01-28,Magnetotransport properties and giant anomalous Hall angle in half-Heusler compound TbPtBi,"Magnetic lanthanide half-Heuslers ($R$PtBi; $R$ being the lanthanide)
+represent an attractive subgroup of the Heusler family and have been identified
+as ideal candidates for time reversal symmetry breaking topological Weyl
+semimetals. In this paper, we present the detailed analysis of the
+magnetotransport properties of frustrated antiferromagnet TbPtBi. This material
+shows large, non-saturating magnetoresistance (MR) with unusual magnetic field
+dependence. The MR of TbPtBi is significantly anisotropic with respect to the
+magnetic field, applied along different crystallographic directions and
+indicates the anisotropic nature of the Fermi surface. The chiral anomaly
+induced negative longitudinal magnetoresistance confirms the presence of Weyl
+fermions. At low temperature, Berry phase driven large anomalous Hall
+conductivity has been observed. The calculated anomalous Hall angle is the
+largest reported so far.",1901.09534v1
+2019-03-04,A Resolution Study of Magnetically Arrested Disks,"We investigate numerical convergence in simulations of magnetically arrested
+disks around spinning black holes. Using the general-relativistic
+magnetohydrodynamics code Athena++, we study the same system at four
+resolutions (up to an effective 512 by 256 by 512 cells) and with two different
+spatial reconstruction algorithms. The accretion rate and general large-scale
+structure of the flow agree across the simulations. This includes the amount of
+magnetic flux accumulated in the saturated state and the ensuing suppression of
+the magnetorotational instability from the strong field. The energy of the jet
+and the efficiency with which spin energy is extracted via the Blandford-Znajek
+process also show convergence. However the spatial structure of the jet shows
+variation across the set of grids employed, as do the Lorentz factors.
+Small-scale features of the turbulence, as measured by correlation lengths, are
+not fully converged. Despite convergence of a number of aspects of the flow,
+modeling of synchrotron emission shows that variability is not converged and
+decreases with increasing resolution even at our highest resolutions.",1903.01509v1
+2019-03-07,Flexible water excitation for fat-free MRI at 3 Tesla using lipid insensitive binomial off-resonant RF excitation (LIBRE) pulses,"Purpose: To develop a robust and flexible low power water excitation pulse
+that enables effective fat suppression at high magnetic field strength.
+Methods: A water excitation method that uses spatially non-selective pulses was
+optimized in numerical simulations, and implemented and tested in phantoms and
+healthy volunteers at 3T. The lipid insensitive binomial off-resonant
+excitation (LIBRE) pulse comprises two low power rectangular sub-pulses that
+have a variable frequency offset, phase offset and duration. The capability and
+extent of LIBRE fat suppression was quantitatively compared with conventional
+fat saturation (FS) and water excitation (WE) techniques. Results: LIBRE
+enables simultaneous water excitation and near complete fat suppression in
+large volumes at 3T as demonstrated by numerical simulations, and experiments.
+In phantoms and in human subjects, the frequency responses matched well with
+those from the numerical simulation. Comparing FS and WE, LIBRE demonstrated an
+improved robustness to magnetic field inhomogeneities, and a much more
+effectively suppressed fat signal. This applied for a range of pulse durations
+and pulses as short as 1.4 ms. Conclusion: A flexible water excitation method
+was developed that shows robust, near complete fat suppression at 3T.",1903.02901v1
+2019-04-26,Homogenous reduced moment in a gapful scalar chiral kagome antiferromagnet,"We present present a quantitative experimental investigation of the scalar
+chiral magnetic order with in $\rm{Nd_3Sb_3Mg_2O_{14}}$. Static magnetization
+reveals a net ferromagnetic ground state, and inelastic neutron scattering from
+the hyperfine coupled nuclear spin reveals a local ordered moment of 1.76(6)
+$\mu_B$, just 61(2)% of the saturated moment size. The experiments exclude
+static disorder as the source of the reduced moment. A 38(1) $\mu$eV gap in the
+magnetic excitation spectrum inferred from heat capacity rules out thermal
+fluctuations and suggests a multipolar explanation for the moment reduction. We
+compare $\rm{Nd_3Sb_3Mg_2O_{14}}$ to Nd pyrochlores and show that it is close
+to a moment fragmented state.",1904.11779v3
+2019-05-03,Field-induced incommensurate ordering in the Heisenberg chains coupled by Ising interaction: Model for the ytterbium aluminum perovskite YbAlO$_3$,"We study isotropic antiferromagnetic Heisenberg chains coupled by
+antiferromagnetic Ising interaction as an effective spin model for the
+ytterbium aluminum perovskite YbAlO$_3$. Using the density-matrix
+renormalization group (DMRG) method we calculate the magnetization curve, local
+spin, central charge, and dynamical spin structure factors in the presence of
+magnetic field. From the fitting of the experimental magnetization curve, the
+effective intrachain and interchain couplings are estimated as $J=2.3$K and
+$J_{\rm ic}=0.8$K, respectively. We can quantitatively explain the experimental
+observations: (i) phase transition from antiferromagnetic to incommensurate
+order at field 0.35T, and (ii) quantum critical behaviors at the saturation
+field of 1.21T. Furthermore, the low-energy excitations in the experimental
+inelastic neutron scattering spectra can be well described by our DMRG results
+of the dynamical structure factors.",1905.01204v1
+2019-05-14,Slow Vortex Creep Induced by Strong Grain Boundary Pinning in Advanced Ba122 Superconducting Tapes,"We report the temperature, magnetic field and time dependences of
+magnetization in advanced Ba122 superconducting tapes. The sample exhibits a
+peculiar vortex creep behavior. Below 10 K, the normalized magnetization
+relaxation rate S=dln(-M)/dln(t) shows a temperature insensitive plateau with a
+value comparable to that of the low temperature superconductors, which can be
+explained within the framework of the collective creep theory. It then enters
+into a second collective creep regime when the temperature increases.
+Interestingly, the relaxation rate below 20 K tends to saturate with the
+increasing field. However, it changes to a power law dependence on field at a
+higher temperature. A vortex phase diagram composed of the collective and the
+plastic creep regions is concluded. Benefit from the strong grain boundary
+pinning, the advanced Ba122 superconducting tape has promising potential to be
+applied not only in liquid helium but also in liquid hydrogen or at the
+temperature accessible with cryocoolers.",1905.05372v1
+2019-06-22,Observation of two-level critical state in the superconducting FeTe thin films,"FeTe, a non-superconducting parent compound in the iron-chalcogenide family,
+becomes superconducting after annealing in oxygen. Under the presence of
+magnetism, spin-orbit coupling, inhomogeneity and lattice distortion, the
+nature of its superconductivity is not well understood. Here, we combined
+mutual inductance technique with magneto transport to study the magnetization
+and superconductivity of FeTe thin films. We found that the films with the
+highest Tc showed non-saturating superfluid density and a strong magnetic
+hysteresis distinct from that in a homogeneous superconductor. Such hysteresis
+can be well explained by a two-level critical state model and suggested the
+importance of granularity to superconductivity in this compound.",1906.09418v1
+2019-07-16,"Magnetic, Structural and cation distribution studies on $FeO \cdot Fe_{(2-x)}Nd_{x}O_{3}$ ($x=0.00, 0.02, 0.04, 0.06 \text{ and } 0.1$) nanoparticles","We synthesized and characterized the colloidal suspensions of $FeO \cdot
+Fe_{(2-x)}Nd_{x}O_{3}$ nanoparticles with $x=0.00, 0.02, 0.04, 0.06 \text{ and
+}0.1.$ The effect of the $Fe^{3+}$ ion replacement by $Nd^{3+}$ on the crystal
+structure is in-depth studied, through X-ray diffraction (XRD) and the obtained
+cation distribution. The magnetic properties of the synthesized $FeO \cdot
+Fe_{(2-x)}Nd_{x}O_{3}$ nanoparticles also were investigated and corroborated by
+other physical methods. A remarkable saturation magnetization of 105
+$Am^{2}/kg$ was achieved for $x=0.06$.",1907.07183v1
+2019-07-30,Superconducting nanowires as high-rate photon detectors in strong magnetic fields,"Superconducting nanowire single photon detectors are capable of single-photon
+detection across a large spectral range, with near unity detection efficiency,
+picosecond timing jitter, and sub-10 $\mu$m position resolution at rates as
+high as 10$^{9}$ counts/s. In an effort to bring this technology into nuclear
+physics experiments, we fabricate Niobium Nitride nanowire detectors using ion
+beam assisted sputtering and test their performance in strong magnetic fields.
+We demonstrate that these devices are capable of detection of 400 nm wavelength
+photons with saturated internal quantum efficiency at temperatures of 3 K and
+in magnetic fields potentially up to 5 T at high rates and with nearly zero
+dark counts.",1907.13059v2
+2019-08-05,Presaturation phase with no dipolar order in a quantum ferro-antiferromagnet,"Magnetization, magnetocaloric, calorimetric, neutron and X-ray diffraction
+and inelastic neutron scattering measurements are performed on single crystals
+of BaCdVO(PO$_4$)$_2$. The low-temperature crystal structure is found to be of
+a lower symmetry than previously assumed. The result is a more complicated
+model spin Hamiltonian, which we infer from measurements of the spin wave
+dispersion spectrum. The main finding is a novel spin state which emerges in
+high magnetic fields after antiferromagnetic order is terminated at
+$H_{c1}\simeq 4.0$ T. It is a distinct thermodynamic phase with a well-defined
+phase boundary at $H_{c2}\simeq 6.5$ T and is clearly separate from the fully
+saturated phase. Yet, it shows no conventional (dipolar) magnetic long range
+order. We argue that it is fully consistent with the expectations for a quantum
+bond-nematic state.",1908.01734v3
+2019-09-13,Hidden spin-orbital order in the Kitaev hyperhoneycomb $β$-Li$_2$IrO$_3$,"We report the existence of a phase transition at high temperature in the 3D
+Kitaev candidate material, $\beta$-Li$_2$IrO$_3$. We show that the transition
+is bulk, intrinsic and orders a tiny magnetic moment with a spatially
+anisotropic saturation moment. We show that even though this transition is
+global, it does not freeze the local Ir moments, which order at much lower
+temperatures into an incommensurate state. Rather, the ordered moment has an
+orbital origin that is coupled to spin correlations, likely of a Kitaev origin.
+The separate ordering of spin-correlated orbital moments and of local Ir
+moments reveals a novel way in which magnetic frustration in Kitaev systems can
+lead to coexisting magnetic states.",1909.06355v1
+2019-10-22,Evidence of one-dimensional magnetic heat transport in the triangular-lattice antiferromagnet Cs$_2$CuCl$_4$,"We report on low-temperature heat-transport properties of the spin-1/2
+triangular-lattice antiferromagnet Cs$_2$CuCl$_4$. Broad maxima in the thermal
+conductivity along the three principal axes, observed at about 5 K, are
+interpreted in terms of the Debye model, including the phonon Umklapp
+scattering. For thermal transport along the $b$ axis, we observed a pronounced
+field-dependent anomaly, close to the transition into the three-dimensional
+long-range-ordered state. No such anomalies were found for the transport along
+the $a$ and $c$ directions. We argue that this anisotropic behavior is related
+to an additional heat-transport channel through magnetic excitations, that can
+best propagate along the direction of the largest exchange interaction.
+Besides, peculiarities of the heat transport of Cs$_2$CuCl$_4$ in magnetic
+fields up to the saturation field and above are discussed.",1910.09833v1
+2019-10-22,Disordered quantum spin state in the stripe lattice system consisting of triangular and square tilings,"Quantum fluctuations originating phase competition or geometrical frustration
+of spins lead to novel states such as a quantum critical point and a quantum
+spin liquid where the strong quantum fluctuations suppress any ordered states
+even at 0 K. Utilizing site-selective NMR for a quasi-two dimensional organic
+conductor $\lambda$-(STF)$_2$GaCl$_4$, we investigate the non-magnetic
+insulating phase of the stripe lattice system consisting of triangular and
+square tilings. We found development of AF spin fluctuations with decreasing
+temperature. Regardless of large enhancement of spin-lattice relaxation rate
+$1/T_1$ owing to critical slowing down below 10 K, no long-range magnetic
+ordering was observed down to 1.63 K two orders of magnitude less than the
+exchange interaction $J/k_{\rm B} \simeq$ 194 K. Moreover, $1/T_1$ saturated
+below 3.5 K. These results are in stark contrast to observed behaviors so far
+in other non-magnetic ground states discussed in terms of spin liquids,
+demonstrating realization of an exotic quantum state accompanying quantum
+criticality.",1910.09963v2
+2019-11-19,Magneto-structural correlations in a systematically disordered B2 lattice,"Ferromagnetism in certain B2 ordered alloys such as Fe$_{60}$Al$_{40}$ can be
+switched on, and tuned, via antisite disordering of the atomic arrangement. The
+disordering is accompanied by a $\sim$1 % increase in the lattice parameter.
+Here we performed a systematic disordering of B2 Fe$_{60}$Al$_{40}$ thin films,
+and obtained correlations between the order parameter ($S$), lattice parameter
+($a_0$), and the induced saturation magnetization ($M_{s}$). As the lattice is
+gradually disordered, a critical point occurs at 1-$S$=0.6 and $a_0$=291 pm,
+where a sharp increase of the $M_{s}$ is observed. DFT calculations suggest
+that below the critical point the system magnetically behaves as it would still
+be fully ordered, whereas above, it is largely the increase of $a_0$ in the
+disordered state that determines the $M_{s}$. The insights obtained here can be
+useful for achieving tailored magnetic properties in alloys through
+disordering.",1911.08404v1
+2019-12-10,Structural properties and magnetoresistance of La$_{1.952}$Sr$_{0.048}$CuO$_4$ thin films,"The evolution of the structural and transport properties of underdoped
+La$_{1.952}$Sr$_{0.048}$CuO$_4$ thin films under compressive epitaxial strain
+has been studied. The films of different thicknesses $d$ (from 26 nm to 120 nm)
+were deposited using an insulating target. The onset of superconductivity in
+the films is observed at temperatures as high as 26 K, while small residual
+resistance persists at low temperatures, indicating that superconductivity is
+inhomogeneous. The resistance measured under perpendicular magnetic field
+saturates below about 0.65 K, suggesting a possible existence of
+nonconventional metallic state. The magnetic-field-tuned
+superconductor-insulator transition is observed at magnetic field of about 32
+T.",1912.04594v2
+2019-12-18,Magnetic hysteresis behavior of granular manganite La$_{0.67}$Ca$_{0.33}$MnO$_3$ nanotubes,"A silicon micromechanical torsional oscillator is used to measure the
+hysteresis loops of two manganite La_0.67Ca_0.33MnO_3 nanotubes at different
+temperatures, applying an external field along its main axes. These structures
+are composed of nanograins with a ferromagnetic core surrounded by a dead
+layer. Micromagnetic calculations based on the stochastic
+Landau-Lifshitz-Gilbert equation, are performed to validate a simple model that
+allows for quantitatively describing the ferromagnetic behavior of the system.
+Further simulations are used to analyze the experimental data more in depth and
+to calculate the coercive field, the saturation and remanent magnetizations,
+and the effective magnetic volume for single nanotubes, over a wide temperature
+range.",1912.08844v2
+2020-01-10,Particle trajectories in Weibel filaments: influence of external field obliquity and chaos,"When two collisionless plasma shells collide, they interpenetrate and the
+overlapping region may turn Weibel unstable for some values of the collision
+parameters. This instability grows magnetic filaments which, at saturation,
+have to block the incoming flow if a Weibel shock is to form. In a recent paper
+[J. Plasma Phys. (2016), vol. 82, 905820403], it was found implementing a toy
+model for the incoming particles trajectories in the filaments, that a strong
+enough external magnetic field $\mathbf{B}_0$ can prevent the filaments to
+block the flow if it is aligned with. Denoting $B_f$ the peak value of the
+field in the magnetic filaments, all test particles stream through them if
+$\alpha=B_0/B_f > 1/2$. Here, this result is extended to the case of an oblique
+external field $B_0$ making an angle $\theta$ with the flow. The result,
+numerically found, is simply $\alpha > \kappa(\theta)/\cos\theta$, where
+$\kappa(\theta)$ is of order unity. Noteworthily, test particles exhibit
+chaotic trajectories.",2001.03473v1
+2020-02-25,Exceedingly Small Moment Itinerant Ferromagnetism of Single Crystalline La$_{5}$Co$_{2}$Ge$_{3}$,"Single crystals of monoclinic La$_{5}$Co$_{2}$Ge$_{3}$ were grown using a
+self-flux method and were characterized by room-temperature powder X-ray
+diffraction, anisotropic temperature and field dependent magnetization,
+temperature dependent resistivity, specific heat, and muon spin rotation.
+La$_{5}$Co$_{2}$Ge$_{3}$ has a Curie temperature ($T_\mathrm{C}$) of 3.8~K and
+clear signatures of ferromagnetism in magnetization and $\mu SR$ data, as well
+as a clear loss of spin disorder scattering in resistivity data and a sharp
+specific heat anomaly. The magnetism associated with La$_{5}$Co$_{2}$Ge$_{3}$
+is itinerant, has a change in the entropy at $T_\mathrm {C}$ of $\simeq$0.05 R
+ln2 per mol-Co, and has a low-field saturated moment of $\sim 0.1 \mu_\mathrm
+B$/Co, making it a rare, itinerant, small moment, low $T_\mathrm C$ compound.",2002.11050v1
+2020-03-11,SIMBA: A Skyrmionic In-Memory Binary Neural Network Accelerator,"Magnetic skyrmions are emerging as potential candidates for next generation
+non-volatile memories. In this paper, we propose an in-memory binary neural
+network (BNN) accelerator based on the non-volatile skyrmionic memory, which we
+call as SIMBA. SIMBA consumes 26.7 mJ of energy and 2.7 ms of latency when
+running an inference on a VGG-like BNN. Furthermore, we demonstrate
+improvements in the performance of SIMBA by optimizing material parameters such
+as saturation magnetization, anisotropic energy and damping ratio. Finally, we
+show that the inference accuracy of BNNs is robust against the possible
+stochastic behavior of SIMBA (88.5% +/- 1%).",2003.05132v1
+2020-04-10,Extremely Weakly Interacting $ΔS_z = 0$ and $ΔS_z = 1$ Excitations and Evidence for Fractional Quantization in a Magnetization Plateau: CeSb,"The plateau at 1/3 of the saturation magnetization, $M_s$, in the metamagnet
+CeSb is accompanied by a state of ferromagnetic layers of spins in an
+up-up-down sequence. We measured $M$ and the specific heat, $C$, in the
+plateau, spin wave analyses of which reveal two distinct branches of
+excitations. Those with $\Delta S_z = 1$ as measured by $M$, coexist with a
+much larger population of $\Delta S_z = 0$ excitations measured by $C$ but
+invisible to $M$. The large density of $\Delta S_z = 0$ excitations, their
+energy gap, and their seeming lack of interaction with $\Delta S_z = 1$
+excitations suggest an analogy with astrophysical dark matter. Additionally, in
+the middle of the plateau three sharp jumps in $M(H)$ are seen, the size of
+which, $0.15 $%$M_s$, is consistent with fractional quantization of
+magnetization-per-site in the down-spin layers.",2004.05236v3
+2020-05-10,Linear nonsaturating magnetoresistance in the Nowotny chimney ladder compound Ru$_2$Sn$_3$,"We present magnetoresistivity measurements in high-quality single crystals of
+the Nowotny chimney ladder compound Ru$_2$Sn$_3$. We find a linear and
+nonsaturating magnetoresistance up to 20 T. The magnetoresistance changes with
+the magnetic field orientation at small magnetic fields, from a positive to a
+negative curvature. Above 5 T, the magnetoresistance shows no sign of
+saturation up to 20 T for any measured angle. The shape of the anisotropy in
+the magnetoresistance remains when increasing temperature and Kohler's rule is
+obeyed. We associate the linear and nonsaturating magnetoresistance to a small
+Fermi surface with hot spots, possibly formed as a consequence of the
+structural transition. We discuss the relevance of electron-electron
+interactions under magnetic fields and aspects of the topologically nontrivial
+properties expected in Ru$_2$Sn$_3$.",2005.04632v1
+2020-06-01,Spin-wave spectroscopy of individual ferromagnetic nanodisks,"The increasing demand for ultrahigh data storage densities requires
+development of 3D magnetic nanostructures. In this regard, focused electron
+beam induced deposition (FEBID) is a technique of choice for direct-writing of
+various complex nano-architectures. However, intrinsic properties of
+nanomagnets are often poorly known and can hardly be assessed by local optical
+probe techniques. Here, we demonstrate spatially resolved spin-wave
+spectroscopy of individual circular magnetic elements with radii down to 100
+nm. The key component of the setup is a microwave antenna whose microsized
+central part is placed over a movable substrate with well-separated CoFe-FEBID
+nanodisks. The circular symmetry of the disks gives rise to standing spin-wave
+resonances and allows for the deduction of the saturation magnetization and the
+exchange stiffness of the material using an analytical theory. The presented
+approach is especially valuable for the characterization of direct-write
+elements opening new horizons for 3D nanomagnetism and magnonics.",2006.00763v1
+2020-06-02,Dynamic magnetization in non-Hermitian quantum spin system,"We report a global effect induced by the local complex field, associated with
+the spin-exchange interaction. High-order exceptional point up to ($N+1$)-level
+coalescence is created at the critical local complex field applied to the
+$N$-size quantum spin chain. The ($N+1$)-order coalescent level is a saturated
+ferromagnetic ground state in the isotropic spin system. Remarkably, the final
+state always approaches the ground state for an arbitrary initial state with
+any number of spin flips; even if the initial state is orthogonal to the ground
+state. Furthermore, the switch of macroscopic magnetization is solely driven by
+the time and forms a hysteresis loop in the time domain. The retentivity and
+coercivity of the hysteresis loop mainly rely on the non-Hermiticity. Our
+findings highlight the cooperation of non-Hermiticity and the interaction in
+quantum spin system, suggest a dynamical framework to realize magnetization,
+and thus pave the way for the non-Hermitian quantum spin system.",2006.01324v1
+2020-06-02,The magnetic helicity density patterns from non-axisymmetric solar dynamo,"In the paper we study the helicity density patterns which can result from the
+emerging bipolar regions. Using the relevant dynamo model and the magnetic
+helicity conservation law we find that the helicity density pattern around the
+bipolar regions depends on the configuration of the ambient large-scale
+magnetic field, and in general they show the quadrupole distribution. The
+position of this pattern relative to the equator can depend on the tilt of the
+bipolar region. We compute the time-latitude diagrams of the helicity density
+evolution. The longitudinally averaged effect of the bipolar regions show two
+bands of sign for the density distribution in each hemisphere. Similar helicity
+density patterns are provided by the helicity density flux from the emerging
+bipolar regions subjected to the surface differential rotation. Examining
+effect of helicity fluxes from the bipolar regions on the large-scale dynamo we
+find that its effect to the dynamo saturation is negligible.",2006.01982v3
+2020-07-08,Sign-reversal electron magnetization in Mn-doped semiconductor structures,"The diversity of various manganese types and its complexes in the Mn-doped
+${\rm A^{III}B^V}$ semiconductor structures leads to a number of intriguing
+phenomena. Here we show that the interplay between the ordinary substitutional
+Mn acceptors and interstitial Mn donors as well as donor-acceptor dimers could
+result in a reversal of electron magnetization. In our all-optical scheme the
+impurity-to-band excitation via the Mn dimers results in direct orientation of
+the ionized Mn-donor $d$ shell. A photoexcited electron is then captured by the
+interstitial Mn and the electron spin becomes parallel to the optically
+oriented $d$ shell. That produces, in the low excitation regime, the
+spin-reversal electron magnetization. As the excitation intensity increases the
+capture by donors is saturated and the polarization of delocalized electrons
+restores the normal average spin in accordance with the selection rules. A
+possibility of the experimental observation of the electron spin reversal by
+means of polarized photoluminescence is discussed.",2007.04098v1
+2020-09-17,Investigation of entanglement measures across the magnetization process of a highly frustrated spin-1/2 Heisenberg octahedral chain as a new paradigm of the localized-magnon approach,"The bipartite entanglement across the magnetization process of a highly
+frustrated spin-1/2 Heisenberg octahedral chain is examined within the concept
+of localized magnons, which enables a simple calculation of the concurrence
+measuring a strength of the pairwise entanglement between nearest-neighbor and
+next-nearest-neighbor spins from square plaquettes. A full exact
+diagonalization of the finite-size Heisenberg octahedral chain with up to 4
+unit cells (20 spins) evidences an extraordinary high precision of the
+localized-magnon theory in predicting measures of the bipartite entanglement at
+sufficiently low temperatures. While the monomer-tetramer phase emergent at low
+enough magnetic fields exhibits presence (absence) of the bipartite
+entanglement between the nearest-neighbor (next-nearest-neighbor) spins, the
+magnon-crystal phase emergent below the saturation field contrarily displays
+identical bipartite entanglement between the nearest-neighbor and
+next-nearest-neighbor spins. The presented results verify a new paradigm of the
+localized-magnon approach concerned with a simple calculation of entanglement
+measures.",2009.08504v1
+2020-09-25,Universal behavior of the bosonic metallic ground state in a two-dimensional superconductor,"Anomalous metallic behavior, marked by a saturating finite resistivity much
+lower than the Drude estimate, has been observed in a wide range of
+two-dimensional superconductors. Utilizing the electrostatically gated
+LaAlO3/SrTiO3 interface as a versatile platform for superconductor-metal
+quantum phase transitions, we probe variations in the gate, magnetic field, and
+temperature to construct a phase diagram crossing from superconductor,
+anomalous metal, vortex liquid, to Drude metal states, combining longitudinal
+and Hall resistivity measurements. We find that the anomalous metal phases
+induced by gating and magnetic field, although differing in symmetry, are
+connected in the phase diagram and exhibit similar magnetic field response
+approaching zero temperature. Namely, within a finite regime of the anomalous
+metal state, the longitudinal resistivity linearly depends on field while the
+Hall resistivity diminishes, indicating an emergent particle-hole symmetry. The
+universal behavior highlights the uniqueness of the quantum bosonic metallic
+state, distinct from bosonic insulators and vortex liquids.",2009.12403v2
+2020-11-11,Magnetic field decay in young radio pulsars,"The role of magnetic field decay in normal radio pulsars is still debated. In
+this paper we present results which demonstrate that an episode of magnetic
+field decay in hot young neutron stars can explain anomalous values of braking
+indices recently measured for more than a dozen of sources. It is enough to
+have few tens of per cent of such hot NSs in the total population to explain
+observables. Relatively rapid decay operates at ages
+$\lesssim$~few~$\times100$~kyrs with a characteristic timescale of a similar
+value. We speculate that this decay can be related to electron scattering off
+phonons in neutron star crusts. This type of decay saturates as a neutron star
+cools down. Later on, a much slower decay due to crustal impurities dominates.
+Finally, we demonstrate that this result is in agreement with our early
+studies.",2011.05778v1
+2020-11-24,Drive Dependence of the Hall Angle for a Sliding Wigner Crystal in a Magnetic Field,"We numerically examine the depinning and sliding dynamics of a Wigner crystal
+in the presence of quenched disorder and a magnetic field. In the disorder-free
+limit, the Wigner crystal Hall angle is independent of crystal velocity, but
+when disorder is present, we find that Hall angle starts near zero at the
+depinning threshold and increases linearly with increasing drive before
+reaching a saturation close to the disorder free value at the highest drives.
+The drive dependence is the result of a side jump effect produced when the
+charges move over pinning sites. The magnitude of the side jump is reduced at
+the higher velocities. The drive dependent Hall angle is robust for a wide
+range of disorder parameters and should be a generic feature of classical
+charges driven in the presence of quenched disorder and a magnetic field.",2011.11802v1
+2020-11-24,"Structural, dielectric and magnetic studies of (0-3) type multiferroic (1-x) BaTi0.8Sn0.2O3-(x) La0.5Ca0.5MnO3 (0 <x< 1) composite ceramics","Multiferroic composites with the composition (1-x) BaTi0.8Sn0.2O3 - (x)
+La0.5Ca0.5MnO3 (x =0, 0.3, 0.5, 0.7, 0.9 and 1) were prepared by sol-gel
+techniques. Rietveld refinements of the composites with 0-3 and 3-0 type
+connectivities exhibit the formation of pure phases and confirm the fraction of
+the composite samples. It was found that the composites grain size decreases
+slightly with increasing the La0.5Ca0.5MnO3 content. Magnetic measurements of
+the composite ceramics exhibit a gradual increase in saturation and remanent
+magnetization with increasing La0.5Ca0.5MnO3 content. Dielectric data
+demonstrate that the composite materials show high values of the dielectric
+constant in comparison with the parent compound BaTi0.8Sn0.2O3 (BTSO). In
+addition, an attempt is made to measure the magnetoelectric coupling
+coefficient and to explain the negative permittivity and losses occurring in
+these materials at a certain frequency and temperature conditions.",2011.12270v1
+2021-01-22,Quasi-isotropic orbital magnetoresistance in lightly doped SrTiO$_{3}$,"A magnetic field parallel to an electrical current does not produce a Lorentz
+force on the charge carriers. Therefore, orbital longitudinal magnetoresistance
+is unexpected. Here we report on the observation of a large and non saturating
+magnetoresistance in lightly doped SrTiO$_{3-x}$ independent of the relative
+orientation of current and magnetic field. We show that this quasi-isotropic
+magnetoresistance can be explained if the carrier mobility along all
+orientations smoothly decreases with magnetic field. This anomalous regime is
+restricted to low concentrations when the dipolar correlation length is longer
+than the distance between carriers. We identify cyclotron motion of electrons
+in a potential landscape tailored by polar domains as the cradle of
+quasi-isotropic orbital magnetoresistance. The result emerges as a challenge to
+theory and may be a generic feature of lightly-doped quantum paralectric
+materials.",2101.09062v1
+2021-01-26,Stabilizing current-driven steady flows of 180$^{\circ}$ domain walls in spin valves by interfacial Dzyaloshinskii-Moriya interaction,"Modulations of interfacial Dzyaloshinskii-Moriya interaction (iDMI) on
+current-driven dynamics of 180$^{\circ}$ domain walls (180DWs) in long and
+narrow spin valves (LNSVs) with heavy-metal caplayers are systematically
+investigated. We focus on LNSVs with in-plane magnetic anisotropy in their free
+layers. For planar-transverse polarizers (pinned layers of LNSVs), the Walker
+breakdown can be postponed considerably (practical infinity) by iDMI. More
+interestingly, the originally unstable traveling mode is also stabilized by
+iDMI with high saturation velocity thus serves as fast carrier of information.
+For parallel polarizers, the Walker limit is increased and the corresponding
+modifications of iDMI to wall velocity in both steady and precessional flows of
+180DWs are provided. For perpendicular polarizers, precessional flow of 180DWs
+is absent due to the stability of stationary mode beyond the modified Walker
+limit. For LNSVs with perpendicular magnetic anisotropy in their free layers,
+similar results are obtained. Our findings open new possibilities for
+developing magnetic nanodevices based on 180DW propagation with low energy
+consumption and high robustness.",2101.10590v1
+2021-03-16,A non-local fluid closure for modeling cyclotron resonance in collisionless magnetized plasmas,"A fluid description for collisionless magnetized plasmas that takes into
+account the effect of cyclotron resonance has been developed. Following the
+same approach as the Landau fluid closure, the heat flux components associated
+with transverse electromagnetic fluctuations are approximated by a linear
+combination of lower-order moments in wavenumber space. The closure
+successfully reproduces the linear cyclotron resonance for electromagnetic
+waves propagating parallel to the ambient magnetic field. In the presence of
+finite temperature anisotropy, the model gives approximately correct prediction
+for an instability destabilized via the cyclotron resonance. A nonlinear
+simulation demonstrates the wave growth consistent with the linear theory
+followed by the reduction of initial anisotropy, and finally, the saturation of
+the instability. The isotropization may be understood in terms of quasi-linear
+theory, which is developed within the framework of the fluid model but very
+similar to its fully kinetic counterpart. The result indicates that both linear
+and nonlinear collisionless plasma responses are approximately incorporated in
+the fluid model.",2103.08880v1
+2021-04-29,Integral Line-of-Sight Path Following Control of Magnetic Helical Microswimmers Subject to Step-Out Frequencies,"This paper investigates the problem of straight-line path following for
+magnetic helical microswimmers. The control objective is to make the helical
+microswimmer to converge to a straight line without violating the step-out
+frequency constraint. The proposed feedback control solution is based on an
+optimal decision strategy (ODS) that is cast as a trust-region subproblem
+(TRS), i.e., a quadratic program over a sphere. The ODS-based control strategy
+minimizes the difference between the microrobot velocity and an integral
+line-of-sight (ILOS)-based reference vector field while respecting the magnetic
+saturation constraints and ensuring the absolute continuity of the control
+input. Due to the embedded integral action in the reference vector field, the
+microswimmer will follow the desired straight line by compensating for the
+drift effect of the environmental disturbances as well as the microswimmer
+weight.",2104.14241v1
+2021-05-10,Role of higher-order effects in spin-misalignment small-angle neutron scattering of high-pressure torsion nickel,"Magnetic-field-dependent unpolarized small-angle neutron scattering (SANS)
+experiments demonstrate that high-pressure torsion (HPT) straining induces spin
+misalignments in pure Ni, which persist in magnetic fields up to 4 T. The
+spin-misalignment scattering patterns are elongated perpendicular to the
+applied magnetic field due to an unusual predominant longitudinal
+$sin^2(\theta)$-type angular anisotropy. Such a contribution cannot be
+explained by the conventional second order (in spin misalignment amplitude)
+micromagnetic SANS theory in the approach-to-saturation regime, nor can its
+magnitude relative to the other features of the cross sections by the third
+order micromagnetic SANS theory. This indicates that the high-density of
+crystal defects induced via HPT straining in Ni makes such higher-order effects
+in the micromagnetic SANS cross sections observable.",2105.04167v1
+2021-06-14,Lepton-driven Non-resonant Streaming Instability,"A strong super-Alfv\'{e}nic drift of energetic particles (or cosmic rays,
+CRs) in a magnetized plasma can amplify the magnetic field significantly
+through non-resonant streaming instability (NRSI). While the traditional
+analysis is done for an ion current, here we use kinetic particle-in-cell
+simulations to study how the NRSI behaves when it is driven by electrons or by
+a mixture of electrons and positrons. In particular, we characterize growth
+rate, spectrum, and helicity of the unstable modes, as well the level of
+magnetic field at saturation. Our results are potentially relevant for several
+space/astrophysical environments (e.g, electron strahl in the solar wind, at
+oblique non-relativistic shocks, around pulsar wind nebulae) and also in
+laboratory experiments.",2106.07672v1
+2021-09-05,Spin-current amplification by stimulated spin pumping,"Stimulated emission is a process during which an atomic system gives away
+energy to create a coherent photon. It is fundamental to the operation of the
+optical amplifier. Here we propose two mechanisms for amplifying AC spin
+currents in a solid-state magnetic medium by a stimulated spin pumping process.
+The first is synchronous and consists of phase-locked pulses that perturb a
+precessing magnetic moment. The second is asynchronous and is driven by DC spin
+currents. The amplification relies on a non-adiabatic interaction taking place
+in a ferromagnetic medium in which the magnetic moment emits spin angular
+momentum in the form of spin current before equilibrating with the environment.
+The pumped spin current amplifies or absorbs the injected AC spin current
+mimicking the operation of the optical gain medium as readily seen from the
+gain saturation profiles. The mechanisms we propose are a first step towards a
+realistic spin current amplifier.",2109.02078v1
+2021-10-05,Experimental study of transport properties of Weyl semimetal LaAlGe thin films grown by molecular beam epitaxy,"Rare earth compounds display diverse electronic, magnetic, and
+magneto-transport properties. Recently these compounds of the type RAlGe (R =
+La, Ce, Pr) have been shown to exhibit Weyl semimetallic behavior. In this
+work, we have investigated the crystal structure, electronic, and
+magneto-transport properties of the Weyl semimetal LaAlGe thin films grown by
+molecular beam epitaxy. The temperature dependence of longitudinal resistivity
+at different magnetic fields is discussed. Observations of magnetoresistances
+and Hall effect at different temperatures and their evolution with magnetic
+field up to 6 T are also discussed with relevant mechanisms. We have observed
+positive unsaturated magnetoresistances, with a small quadratic contribution at
+low temperatures, which tends to saturate at higher fields. The Hall
+measurements confirm the electron-dominated semimetallic conduction with an
+average charge carrier density of ~ 9.68*10^21 cm^(-3) at room temperature.",2110.02322v1
+2021-10-25,Spin dependent charge transfer in MoSe2/hBN/Ni hybrid structures,"We present magneto-photoluminescence measurements in a hybrid 2D
+semiconductor/ferromagnetic structure consisting of MoSe2/hBN/Ni. When the
+Nickel layer is magnetized, we observe circularly polarized photoluminescence
+of the trion peak in MoSe2 monolayer under linearly polarized excitation. This
+build-up of circular polarization can reach a measured value of about 4% when
+the magnetization of Ni is saturated perpendicularly to the sample plane, and
+changes its sign when the magnetization is reversed. The circular polarization
+decreases when the hBN barrier thickness increases. These results are
+interpreted in terms of a spin-dependent charge transfer between the MoSe2
+monolayer and the Nickel film. The build-up of circular polarization is
+observed up to 120 K, mainly limited by the trion emission that vanishes with
+temperature.",2110.13007v1
+2022-01-20,Small-angle neutron scattering by spatially inhomogeneous ferromagnets with a nonzero average uniaxial anisotropy,"Micromagnetic small-angle neutron scattering theory is well established for
+analyzing spin-misalignment scattering data of bulk ferromagnets. Here, this
+theory is extended to allow for a global uniaxial magnetic anisotropy (texture)
+of the material, in addition to the already included random zero-average local
+anisotropy. Macroscopic cross-sections and spin-misalignment response functions
+are computed analytically for several practically relevant mutual anisotropy
+and external magnetic field orientations in both parallel and perpendicular
+scattering geometries for field magnitudes both above and below the rotational
+saturation. Some of these expressions are tested on published experimental data
+of magnetic-field-annealed Vitroperm and plastically-deformed Ni, allowing to
+determine the corresponding global uniaxial anisotropy quality factors.",2201.08334v1
+2022-02-15,Analysis of the robustness and dynamics of spin-locking preparations for the detection of oscillatory magnetic fields,"Extracting quantitative information of neuronal signals by non-invasive
+imaging is an outstanding challenge for understanding brain function and
+pathology. However, state-of-the-art techniques offer low sensitivity to deep
+electrical sources. Stimulus induced rotary saturation (SIRS) is a recently
+proposed magnetic resonance imaging (MRI) sequence that detects oscillatory
+magnetic fields using a spin-lock preparation. Phantom experiments and
+simulations proved its efficiency and sensitivity, but the susceptibility of
+the method to field inhomogeneities is still not well understood. In this
+study, we simulated and analyzed the dynamic of three spin-lock preparations
+and their response to field inhomogeneities in the presence of a resonant
+oscillating field. We show that the composite spin-lock preparation is more
+robust against field variations within the double resonance effect. In
+addition, we tested the capability of the chosen composite spin-lock
+preparation to recover information about the spectral components of a composite
+signal. This study sets the bases to move one step further towards the clinical
+application of MR-based neuronal current imaging.",2202.07705v2
+2022-03-04,Simultaneous optical trapping and magnetic micromanipulation of ferromagnetic iron-doped upconversion microparticles in six degrees of freedom,"Optical trapping of magnetic Fe-oxide particles is notoriously difficult due
+to their high refractive indices, not to mention high absorptivity at the
+trapping infra-red wavelengths. We synthesize Fe co-doped NaYF4:Yb,Er
+ferromagnetic upconversion particles that not only have refractive indices
+conducive for optical trapping, but also heat less than Haematite particles at
+off-resonant wavelengths. These particles are hexagonal shaped with dimensions
+of the order of 3 micrometer and also bear high coercivity of 20 mT and
+saturation magnetisation of 1 Am^2/kg. This enables simultaneous use of optical
+trapping and magnetic forces to generate micro-manipulation in all the six
+degrees of freedom of a rigid body. We also show that these particles heat
+significantly when illuminated on absorption resonance at 975 nm while emitting
+visible light with possible implications for fluorescence microscopy and
+photothermal therapy of cancer cells.",2203.02152v2
+2022-03-05,Quasi-normal modes of dyonic black holes and magneto-hydrodynamics,"We revisit the magneto-hydrodynamics in (2+1) dimensions and confirm that it
+is consistent with the quasi-normal modes of the (3+1) dimensional dyonic black
+holes in the most general set-up with finite density, magnetic field and wave
+vector. We investigate all possible modes (sound, shear, diffusion, cyclotron
+etc.) and their interplay. For the magneto-hydrodynamics we perform a complete
+and detailed analysis correcting some prefactors in the literature, which is
+important for the comparison with quasi-normal modes. For the quasi-normal mode
+computations in holography we identify the independent fluctuation variables of
+the dyonic black holes, which is nontrivial at finite density and magnetic
+field. As an application of the quasi-normal modes of the dyonic black holes we
+investigate a transport property, the diffusion constant. We find that the
+diffusion constant at finite density and magnetic field saturates the lower
+bound at low temperature. We show that this bound can be understood from the
+pole-skipping point.",2203.02642v1
+2022-03-16,Quasistatic evolution in magnetoelasticity under subcritical coercivity assumptions,"We study a variational model of magnetoelasticity both in the static and in
+the quasistatic setting. The model features a mixed Eulerian-Lagrangian
+formulation, as magnetizations are defined on the deformed configuration in the
+actual space. The magnetic saturation constraint is formulated in the reference
+configuration and involves the Jacobian determinant of deformations. These
+belong to the class of possibility discontinuous deformations excluding
+cavitation introduced by Barchiesi, Henao and Mora-Corral. We establish a
+compactness result which, in particular, yields the convergence of the
+compositions of magnetizations with deformations. In the static setting, this
+enables us to prove the existence of minimizers by means of classical lower
+semicontinuity methods. Our compactness result also allows us to address the
+analysis in the quasistatic setting, where we examine rate-independent
+evolutions driven by applied loads and boundary conditions. In this case, we
+prove the existence of energetic solutions.",2203.08744v2
+2022-03-17,Mechanism-based Tuning of Room-temperature Ferromagnetism in Mn-doped \b{eta}-Ga2O3 by Annealing Atmospher,"Mn-doped \b{eta}-Ga2O3 (GMO) films with room-temperature ferromagnetism
+(RTFM) are synthesized by polymer-assisted deposition and the effects of
+annealing atmosphere (air or pure O2 gas) on their structures and physical
+properties are investigated. The characterizations show that the concentrations
+of vacancy defects and Mn dopants in various valence states and lattice
+constants of the samples are all modulated by the annealing atmosphere.
+Notably, the samples annealed in air (GMO-air) exhibit a saturation
+magnetization as strong as 170% times that of the samples annealed in pure O2
+gas (GMO-O2), which can be quantitatively explained by oxygen vacancy (VO)
+controlled ferromagnetism due to bound magnetic polarons established between
+delocalized hydrogenic electrons of VOs and local magnetic moments of Mn2+,
+Mn3+, and Mn4+ ions in the samples. Our results provide insights into
+mechanism-based tuning of RTFM in Ga2O3 and may be useful for design,
+fabrication, and application of related spintronic materials.",2203.09331v4
+2022-05-27,Nanocriticality in the magnetic phase transition of CoO nanoparticles,"The universal theory of critical phase transitions describes the critical
+behavior at second-order phase transitions in infinitely large systems. With
+the increased contemporary interest in nanoscale materials, we investigated CoO
+nanoparticles by means of neutron scattering and found how the theory of
+critical phenomena breaks down in the nanoscale regime. Using CoO as a model
+system, we have identified a size-dependent nanocritical temperature region
+close to the antiferromagnetic phase transition where the magnetic correlation
+length of the nanoparticles converges to a constant value, which is
+significantly smaller than that of the saturated state found at low
+temperatures. This is in clear contrast to the divergence around $T_{\rm N}$
+observed for bulk systems. Our findings of nanocriticality in the magnetic
+phase transition is of great importance for the understanding of phase
+transitions at the nanoscale.",2205.13975v2
+2022-06-05,Evidence of Magnon-Mediated Orbital Magnetism in a Quasi-2D Topological Magnon Insulator,"We explore spin dynamics in Cu(1,3-bdc), a quasi-2D topological magnon
+insulator. The results show that the thermal evolution of Land\'e $g$-factor
+($g$) is anisotropic: $g_\textrm{in-plane}$ reduces while
+$g_\textrm{out-plane}$ increases with increasing temperature $T$. Moreover, the
+anisotropy of the $g$-factor ($\Delta g$) and the anisotropy of saturation
+magnetization ($\Delta M_\textrm{s}$) are correlated below 4 K, but they
+diverge above 4 K. We show that the electronic orbital moment contributes to
+the $g$ anisotropy at lower $T$, while the topological orbital moment induced
+by thermally excited spin chirality dictates the $g$ anisotropy at higher $T$.
+Our work suggests an interplay among topology, spin chirality, and orbital
+magnetism in Cu(1,3-bdc).",2206.02191v1
+2022-07-13,Microwave-free J-driven DNP (MF-JDNP): A proposal for enhancing the sensitivity of solution-state NMR,"J-driven Dynamic Nuclear Polarization (JDNP) was recently proposed for
+enhancing the sensitivity of solution-state nuclear magnetic resonance (NMR),
+while bypassing the limitations faced by conventional (Overhauser) DNP at
+magnetic fields of interest in analytical applications. Like Overhauser DNP,
+JDNP also requires saturating the electronic polarization using high-frequency
+microwaves, known to have poor penetration and associated heating effects in
+most liquids. The present microwave-free JDNP (MF-JDNP) proposal seeks to
+enhance the sensitivity of the solution state NMR by shuttling the sample
+between higher and lower magnetic fields, with one of these fields providing an
+electron Larmor frequency that matches the inter-electron exchange coupling
+Jex. If spins cross this so-called JDNP condition sufficiently fast, we predict
+that a sizable nuclear polarization will be created without microwave
+irradiation. This MF-JDNP proposal requires radicals whose singlet/triplet
+self-relaxation rates are dominated by dipolar hyperfine relaxation, and
+shuttling times that can compete with these electron relaxation processes. This
+communication discusses the theory behind the MF-JDNP, as well as proposals for
+radicals and conditions that could enable this new approach to NMR sensitivity
+enhancement.",2207.05996v3
+2022-07-18,Study of Thin Iron Films for Polarization Analysis of Ultracold Neutrons,"The TUCAN (TRIUMF Ultra-Cold Advanced Neutron) collaboration aims to search
+for the neutron electric dipole moment (nEDM) with unprecedented precision. One
+of the essential elements for the nEDM measurement is a polarization analyzer
+of ultracold neutrons (UCNs), whose main component is a magnetized thin iron
+film. Several thin iron films were deposited on aluminum and silicon ubstrates
+and were characterized by vibrating sample magnetometry and cold-neutron
+reflectometry. A magnetic field required to saturate the iron film is $\sim$12
+kA/m for those on the aluminum substrates and 6.4 kA/m for the silicon
+substrates. The magnetic potential of the iron films on the Si substrate was
+estimated to be 2 T by the neutron reflectometry, which is sufficient
+performance for an UCN polarization analyzer of the nEDM measurement.",2207.08441v1
+2022-10-27,A theoretical model for tellurite-sulfates Na$_2$Cu$_5$(TeO$_3$)(SO$_4$)$_3$(OH)$_4$ and K$_2$Cu$_5$(TeO$_3$)(SO$_4$)$_3$(OH)$_4$,"A theoretical model for two new tellurite-sulfates, namely
+Na$_2$Cu$_5$(TeO$_3$)(SO$_4$)$_3$(OH)$_4$ and K$_2$Cu$_5$(TeO$_3$)(SO$_4$)$_3$
+(OH)$_4$ is determined to be compatible with ab-initio calculations. The
+results obtained in this work show that some previous speculations in the
+literature about the couplings are correct, obtaining a model with a mixture of
+ferromagnetic and antiferromagnetic couplings. We use a combination of
+numerical techniques to study the magnetic properties of the model. Our
+numerical calculations based on the density-matrix renormalization group method
+reveal that the system presents Ising-like magnetization plateaux at rational
+values of the saturation magnetization.",2210.15416v1
+2023-01-26,"Magnetic, Optoelectronic, and Rietveld refined structural properties of Al3+ substituted nanocrystalline Ni-Cu spinel ferrites: An experimental and DFT based study","The nanocrystalline Ni0.7Cu0.3AlxFe2-xO4 (x=0.00: 0.02: 0.10) is prepared
+through the sol-gel autocombustion route.Both XRD and Rietveld confirm the
+single-phase cubic spinel structure of the investigated materials.Other
+structural parameters refined by the Rietveld refinement analysis are
+corroborated to single-phase cubic spinel formation of the NPs.Leveraging a
+vibrating sample magnetometer (VSM) the consequence of Al3+ substitution on the
+magnetic parameters is studied.The saturation magnetization (MS) and Bohr
+magneton are found to decrease with Al3+ substitution.The Remanence ratio and
+coercivity (HC) are observed to be very low suggesting the materials are soft
+ferromagnetic.First-principle calculations were carried out using the density
+functional theory (DFT) to demonstrate the optoelectronic behavior of the
+materials.The electronic bandgap is found low as Eg=2.99eV for the explored
+materials with observing defect states at 0.62eV.The optoelectronic properties
+of Al3+ substituted Ni-Cu ferrite NPs have been characterized through the DFT
+simulation for the first time, demonstrating their potentiality for
+optoelectronic device applications.The materials' optical anisotropy is
+observed along the x-axis, which manifests their tunability through
+light-matter interaction.",2301.11373v1
+2023-03-01,Tailed skyrmions -- an obscure branch of magnetic solitons,"We report tailed skyrmions -- a new class of stable soliton solutions of the
+2D chiral magnet model. Tailed skyrmions have elongated shapes and emerge in a
+narrow range of fields near the transition between the spin spirals and the
+saturated state. We analyze the stability range of these solutions in terms of
+external magnetic field and magnetocrystalline anisotropy. Minimum energy paths
+and the homotopies (continuous transitions) between tailed skyrmions of the
+same topological charge have been calculated using the geodesic nudged elastic
+bands method. The discovery of tailed skyrmions extends the diversity of
+already-known solutions illustrated by complex morphology solitons, such as
+tailed skyrmion bags with and without chiral kinks.",2303.00347v1
+2023-03-03,Unusual coercivity and zero field stabilization of fully saturated magnetization in single crystals of LaCrGe$_3$,"LaCrGe$_3$ is an itinerant, metallic ferromagnet with a Curie temperature
+($T_C$) of $\sim$ 86 K. Whereas LaCrGe$_3$ has been studied extensively as a
+function of pressure as an example of avoided ferromagnetic quantum
+criticality, questions about its ambient pressure ordered state remain;
+specifically, whether there is a change in the nature of the ferromagnetically
+ordered state below $T_C$ $\sim$ 86 K. We present anisotropic $M$($H$)
+isotherms, coupled with anisotropic AC susceptibility data, and demonstrate
+that LaCrGe$_3$ has a remarkable, low temperature coercivity associated with
+exceptionally sharp, complete magnetization reversals to and from fully
+polarized states. This coercivity is temperature dependent, it drops to zero in
+the 40 - 55 K region and reappears in the 70 - 85 K regions. At low
+temperatures LaCrGe$_3$ has magnetization loops and behavior that has
+previously associated with micromagnetic/nanocrystalline materials, not bulk,
+macroscopic samples.",2303.02062v1
+2023-03-24,Observation of Colossal Terahertz Magnetoresistance and Magnetocapacitance in a Perovskite Manganite,"We have studied the terahertz response of a bulk single crystal of
+La$_{0.875}$Sr$_{0.125}$MnO$_3$ at around its Curie temperature, observing
+large changes in the real and imaginary parts of the optical conductivity as a
+function of magnetic field. The terahertz resistance and capacitance extracted
+from the optical conductivity rapidly increased with increasing magnetic field
+and did not show any sign of saturation up to 6 T, reaching 60% and 15%,
+respectively, at 180 K. The observed terahertz colossal magnetoresistance and
+magnetocapacitance effects can be qualitatively explained by using a
+two-component model that assumes the coexistence of two phases with vastly
+different conductivities. These results demonstrate the potential use of
+perovskite manganites for developing efficient terahertz devices based on
+magnetic modulations of the amplitude and phase of terahertz waves.",2303.13820v1
+2023-04-06,Magnetic Fields from Compensated Isocurvature Perturbations,"Compensated isocurvature perturbations (CIPs) are perturbations to the
+primordial baryon density that are accompanied by dark-matter-density
+perturbations so that the total matter density is unperturbed. Such CIPs, which
+may arise in some multi-field inflationary models, can be long-lived and only
+weakly constrained by current cosmological measurements. Here we show that the
+CIP-induced modulation of the electron number density interacts with the
+electron-temperature fluctuation associated with primordial adiabatic
+perturbations to produce, via the Biermann-battery mechanism, a magnetic field
+in the post-recombinaton Universe. Assuming the CIP amplitude saturates the
+current BBN bounds, this magnetic field can be stronger than
+$10^{-15}\,\mathrm{nG}$ at $z\simeq20$ and stronger by an order of magnitude
+than that (produced at second order in the adiabatic-perturbation amplitude) in
+the standard cosmological model, and thus can serve as a possible seed for
+galactic dynamos.",2304.03299v2
+2023-05-10,Double-layer Kagome Metals Pt3Tl2 and Pt3In2,"The connectivity and inherent frustration of the kagome lattice can produce
+interesting electronic structures and behaviors in compounds containing this
+structural motif. Here we report the properties of Pt3X2 (X = In and Tl) that
+adopt a double-layer kagome net structure related to that of the topologically
+nontrivial high temperature ferromagnet Fe3Sn2 and the density wave hosting
+compound V3Sb2. We examined the structural and physical properties of single
+crystal Pt3Tl2 and polycrystalline Pt3In2 using x-ray and neutron diffraction,
+magnetic susceptibility, heat capacity, and electrical transport measurements,
+along with density functional theory calculations of the electronic structure.
+Our calculations show that Fermi levels lie in pseudogaps in the densities of
+states with several bands contributing to transport, and this is consistent
+with our Hall effect, magnetic susceptibility, and heat capacity measurements.
+While electronic dispersions characteristic of simple kagome nets with
+nearest-neighbor hopping are not clearly seen, likely due to the extended
+nature of the Pt 5d states, we do observe moderately large and non-saturating
+magnetoresistance values and quantum oscillations in the magnetoresistance and
+magnetization associated with the kagome nets of Pt.",2305.06491v1
+2023-05-31,The Ferris ferromagnetic resonance technique: principles and applications,"Measurements of ferromagnetic resonance (FMR) are pivotal to modern magnetism
+and spintronics. Recently, we reported on the Ferris FMR technique, which
+relies on large-amplitude modulation of the externally applied magnetic field.
+It was shown to benefit from high sensitivity while being broadband. The Ferris
+FMR also expanded the resonance linewidth such that the sensitivity to spin
+currents was enhanced as well. Eventually, the spin Hall angle ({\theta}_SH)
+was measurable even in wafer-level measurements that require low current
+densities to reduce the Joule heating. Despite the various advantages, analysis
+of the Ferris FMR response is limited to numerical modeling where the linewidth
+depends on multiple factors such as the field modulation profile and the
+magnetization saturation. Here, we describe in detail the basic principles of
+operation of the Ferris FMR and discuss its applicability and engineering
+considerations. We demonstrated these principles in a measurement of the
+orbital Hall effect taking place in Cu, using an Au layer as the orbital to
+spin current converter. This illustrates the potential of the Ferris FMR for
+the future development of spintronics technology.",2306.01783v1
+2023-06-11,Scanning NV magnetometry of focused-electron-beam-deposited cobalt nanomagnets,"Focused-electron-beam-induced deposition is a promising technique for
+patterning nanomagnets for spin qubit control in a single step. We fabricate
+cobalt nanomagnets in such a process, obtaining cobalt contents and saturation
+magnetizations comparable to or higher than those typically obtained using
+electron-beam lithography. We characterize the nanomagnets using transmission
+electron microscopy and image their stray magnetic field using scanning NV
+magnetometry, finding good agreement with micromagnetic simulations. The
+magnetometry reveals the presence of magnetic domains and halo side-deposits,
+which are common for this fabrication technique. Finally, we estimate dephasing
+times for electron spin qubits in the presence of disordered stray fields due
+to these side-deposits.",2306.06650v2
+2023-07-10,Properties underlying the variation of the magnetic field spectral index in the inner solar wind,"Using data from orbits one to eleven of the Parker Solar Probe (PSP) mission,
+the magnetic field spectral index was measured across a range of heliocentric
+distances. The previously observed transition between a value of $-5/3$ far
+from the Sun and a value of $-3/2$ close to the Sun was recovered, with the
+transition occurring at around $50 \, R_{\odot}$ and the index saturating at
+$-3/2$ as the Sun is approached. A statistical analysis was performed to
+separate the variation of the index on distance from its dependence on other
+parameters of the solar wind that are plausibly responsible for the transition;
+including the cross helicity, residual energy, turbulence age and the magnitude
+of magnetic fluctuations. Of all parameters considered the cross helicity was
+found to be by far the strongest candidate for the underlying variable
+responsible. The velocity spectral index was also measured and found to be
+consistent with $-3/2$ over the range of values of cross helicity measured.
+Possible explanations for the behaviour of the indices are discussed, including
+the theorised different behaviour of imbalanced, compared to balanced,
+turbulence.",2307.04682v1
+2023-10-09,Magnetocaloric effect of nanostructured La0.6Sr0.4CoO3,"In this study, we investigate the magnetic and magnetocaloric properties of
+nanostructured La0.6Sr0.4CoO3 (LSC) samples synthesized under confinement
+conditions within porous templates. Using this method, we obtained
+de-agglomerated nanoparticles, which provide us with the feasibility of
+applying them in nanoparticle films that can be tailored to intricate
+geometries. We specifically explored the impact of pore size of the template on
+key parameters including saturation magnetization (MS), Curie temperature (TC),
+maximum entropy change ({\Delta}S), and relative cooling power (RCP). Our
+findings reveal enhancements in those quantities, that are likely to be related
+with the nanostructure of the samples, indicating the potential of
+nanostructured LSC as an active material for magnetic refrigeration devices.
+Our alternative approach of synthesizing magnetocaloric materials under
+confinement conditions presents an exciting prospect for future research and
+development in the field.",2310.05722v1
+2023-11-03,Massive neutron stars as mass gap candidates: Exploring equation of state and magnetic field,"The densities in the cores of the neutron stars (NSs) can reach several times
+that of the nuclear saturation density. The exact nature of matter at these
+densities is still virtually unknown. We consider a number of proposed,
+phenomenological relativistic mean-field equations of state to construct
+theoretical models of NSs. We find that, based on our selected set of models,
+the emergence of exotic matter at these high densities restricts the mass of
+NSs to $\simeq 2.2 M_\odot$. However, the presence of magnetic fields and a
+model anisotropy significantly increases the star's mass, placing it within the
+observational mass gap that separates the heaviest NSs from the lightest black
+holes. Therefore, we propose that gravitational wave observations, like
+GW190814, and other potential candidates within this mass gap, may actually
+represent massive, magnetized NSs.",2311.02169v2
+2024-01-15,The low-spin ground state of the giant Mn wheels,"The single-molecule magnets (SMMs) {Mn$_{70}$} and {Mn$_{84}$} are
+characterized by a 14-site unit cell with $S=2$ spin sites, arranged in a
+circular geometry. Experimentally, these SMMs exhibit a magnetic ground state
+with a notably low total spin, $S_{\text{tot}}=5-7$. This low-spin ground state
+has been up to now difficult to describe theoretically due to the complexity of
+the quantum Heisenberg model for this large system. In this work, we are in
+fact able to quantitatively reproduce the low-spin energy minimum by employing
+large-scale SU(2)-symmetric density-matrix renormalization group (DMRG)
+calculations using previously published exchange parameters obtained by
+density-functional theory. We do not find a low-spin state for the same
+parameters and $S=1$, which leads us to propose that frustrated systems with
+$S\geq2$ are inherently prone to weak ferromagnetic interactions. This could
+account for the prevalence of similar low-spin Mn-based SMMs. Finally, by
+computing the full magnetization curve, we find wide plateaus at 10/14, 11/14,
+12/14 and 13/14 of the saturation. This can be explained by independent 3-site
+clusters with broken inter-cluster bonds.",2401.07552v1
+2024-02-16,Theory of magnetic properties in QED environments: application to molecular aromaticity,"In this work, we present ab initio cavity QED methods which include
+interactions with a static magnetic field and nuclear spin degrees of freedom
+using different treatments of the quantum electromagnetic field. We derive
+explicit expressions for QED-HF magnetizability, nuclear shielding, and
+spin-spin coupling tensors. We apply this theory to explore the influence of
+the cavity field on the magnetizability of saturated, unsaturated, and aromatic
+hydrocarbons, showing the effects of different polarization orientations and
+coupling strengths. We also examine how the cavity affects aromaticity
+descriptors, such as the nucleus-independent chemical shift and magnetizability
+exaltation. We employ these descriptors to study the trimerization reaction of
+acetylene to benzene. We show how the optical cavity induces modifications in
+the aromatic character of the transition state leading to variations in the
+activation energy of the reaction. Our findings shed light on the effects
+induced by the cavity on magnetic properties, especially in the context of
+aromatic molecules, providing valuable insights into understanding the
+interplay between the quantum electromagnetic field and molecules.",2402.10599v1
+2001-05-22,"Amplification, Saturation, and Q Thresholds for Runaway: Growth of Self-Gravitating Structures in Models of Magnetized Galactic Gas Disks","We investigate the susceptibility of gaseous, magnetized galactic disks to
+formation of self-gravitating condensations using two-dimensional, local
+models. We focus on two issues: (1) determining the threshold condition for
+gravitational runaway, taking into account nonlinear effects, and (2)
+distinguishing the magneto-Jeans instability (MJI) that arises under
+inner-galaxy rotation curves from the modified swing amplification (MSA) that
+arises under outer-galaxy rotation curves. For axisymmetric density
+fluctuations, instability is known to require a Toomre parameter Q<1. For
+nonaxisymmetric fluctuations, any nonzero shear $q \equiv -d\ln \Omega /d \ln
+R$ winds up wavefronts such that in linear theory amplification saturates. Any
+Q threshold for nonaxisymmetric gravitational runaway must originate from
+nonlinear effects. We use numerical magnetohydrodynamic simulations to
+demonstrate the anticipated threshold phenomenon, to analyze the nonlinear
+processes involved, and to evaluate the critical value $Q_c$ for stabilization.
+We find $Q_c \sim 1.2-1.4$ for a wide variety of conditions, with the largest
+values corresponding to nonzero but subthermal mean magnetic fields. Our
+findings for $Q_c$ are similar to those inferred from thresholds for active
+star formation in the outer regions of spiral galaxies. MJI is distinct from
+MSA in that opposition to Coriolis forces by magnetic tension, rather than
+cooperation of epicyclic motion with kinematic shear, enables nonaxisymmetric
+density perturbations to grow. We suggest that under low-shear inner-disk
+conditions, $Q_c$ will be larger than that in outer disks by a factor $\sim
+(v_A/q c_s)^{1/2}$, where $v_A$ and $c_s$ are the respective Alfven and sound
+speeds.",0105375v1
+2003-09-02,Magnetorotationally-Driven Galactic Turbulence and the Formation of Giant Molecular Clouds,"Using local 3D MHD simulations, we investigate ways in which galactic
+turbulence associated with the magnetorotational instability (MRI) may
+influence the formation and properties of GMCs. Our disk models are vertically
+stratified and subject to uniform shear. Initial magnetic fields are weak and
+purely vertical. For simplicity, we adopt an isothermal equation of state. We
+find that MRI-driven turbulence develops rapidly, with the saturated-state
+Shakura & Sunyaev parameter alpha~(0.15-0.3) dominated by Maxwell stresses.
+Many of the dimensionless characteristics of the turbulence (e.g. the ratio of
+the Maxwell to Reynolds stresses) are similar to results from previous MRI
+studies of accretion disks, hence insensitive to the degree of vertical disk
+compression, shear rate, and the presence of self-gravity. The density-weighted
+velocity dispersions in non- or weakly self-gravitating disks are sigma_x ~
+sigma_y ~ (0.4-0.6)c_s and sigma_z~(0.2-0.3)c_s, suggesting that MRI can
+contribute significantly to the observed level of galactic turbulence. The
+saturated-state magnetic field strength B ~ 2 \mu G is similar to typical
+galactic values. When self-gravity is strong enough, MRI-driven high-amplitude
+density perturbations are swing-amplified to form Jeans-mass (~10^7 Msun) bound
+clouds. Compared to previous unmagnetized or strongly-magnetized disk models,
+the threshold for nonlinear instability in the present models occurs for
+surface densities at least 50% lower, corresponding to the Toomre parameter
+Q_th~1.6. We present evidence that self-gravitating clouds like GMCs formed
+under conditions similar to our models can lose much of their original spin
+angular momenta by magnetic braking, preferentially via fields threading
+near-perpendicularly to their spin axes.",0309080v1
+2002-02-19,Quantum Monte Carlo with Directed Loops,"We introduce the concept of directed loops in stochastic series expansion and
+path integral quantum Monte Carlo methods. Using the detailed balance rules for
+directed loops, we show that it is possible to smoothly connect generally
+applicable simulation schemes (in which it is necessary to include
+back-tracking processes in the loop construction) to more restricted loop
+algorithms that can be constructed only for a limited range of Hamiltonians
+(where back-tracking can be avoided). The ""algorithmic discontinuities"" between
+general and special points (or regions) in parameter space can hence be
+eliminated. As a specific example, we consider the anisotropic S=1/2 Heisenberg
+antiferromagnet in an external magnetic field. We show that directed loop
+simulations are very efficient for the full range of magnetic fields (zero to
+the saturation point) and anisotropies. In particular for weak fields and
+anisotropies, the autocorrelations are significantly reduced relative to those
+of previous approaches. The back-tracking probability vanishes continuously as
+the isotropic Heisenberg point is approached. For the XY-model, we show that
+back-tracking can be avoided for all fields extending up to the saturation
+field. The method is hence particularly efficient in this case. We use directed
+loop simulations to study the magnetization process in the 2D Heisenberg model
+at very low temperatures. For LxL lattices with L up to 64, we utilize the
+step-structure in the magnetization curve to extract gaps between different
+spin sectors. Finite-size scaling of the gaps gives an accurate estimate of the
+transverse susceptibility in the thermodynamic limit: chi_perp = 0.0659 +-
+0.0002.",0202316v2
+2010-06-24,Dynamics of an Alfven surface in core collapse supernovae,"We investigate the dynamics of an Alfven surface (where the Alfven speed
+equals the advection velocity) in the context of core collapse supernovae
+during the phase of accretion on the proto-neutron star. Such a surface should
+exist even for weak magnetic fields because the advection velocity decreases to
+zero at the center of the collapsing core. In this decelerated flow, Alfven
+waves created by the standing accretion shock instability (SASI) or convection
+accumulate and amplify while approaching the Alfven surface. We study this
+amplification using one dimensional MHD simulations with explicit physical
+dissipation. In the linear regime, the amplification continues until the Alfven
+wavelength becomes as small as the dissipative scale. A pressure feedback that
+increases the pressure in the upstream flow is created via a non linear
+coupling. We derive analytic formulae for the maximum amplification and the non
+linear coupling and check them with numerical simulations to a very good
+accuracy. We also characterize the non linear saturation of this amplification
+when compression effects become important, leading to either a change of the
+velocity gradient, or a steepening of the Alfven wave. Applying these results
+to core collapse supernovae shows that the amplification can be fast enough to
+affect the dynamics, if the magnetic field is strong enough for the Alfven
+surface to lie in the region of strong velocity gradient just above the
+neutrinosphere. This requires the presence of a strong magnetic field in the
+progenitor star, which would correspond to the formation of a magnetar under
+the assumption of magnetic flux conservation. An extrapolation of our analytic
+formula (taking into account the nonlinear saturation) suggests that the Alfven
+wave could reach an amplitude of B ~ 10^15 G, and that the pressure feedback
+could significantly contribute to the pressure below the shock.",1006.4697v2
+2013-10-24,Trends in Ultracool Dwarf Magnetism. II. The Inverse Correlation Between X-ray Activity and Rotation as Evidence for a Bimodal Dynamo,"Observations of magnetic activity indicators in solar-type stars exhibit a
+relationship with rotation with an increase until a ""saturation"" level and a
+moderate decrease in activity in the very fastest rotators (""supersaturation"").
+While X-ray data have suggested that this relationship is strongly violated in
+ultracool dwarfs (UCDs; spectral type >M7), the limited number of X-ray
+detections has prevented firm conclusions. In this paper, we analyze the X-ray
+activity-rotation relation in 38 ultracool dwarfs. Our sample represents the
+largest catalog of X-ray active ultracool dwarfs to date, including seven new
+and four previously-unpublished Chandra observations presented in a companion
+paper. We identify a substantial number of rapidly-rotating UCDs with X-ray
+activity extending two orders of magnitude below the expected saturation level
+and measure a ""supersaturation""-type anticorrelation between rotation and X-ray
+activity. The scatter in UCD X-ray activity at a fixed rotation is ~3 times
+larger than that in earlier-type stars. We discuss several mechanisms that have
+been proposed to explain the data, including centrifugal stripping of the
+corona, and find them to be inconsistent with the observed trends. Instead, we
+suggest that an additional parameter correlated with both X-ray activity and
+rotation is responsible for the observed effects. Building on the results of
+Zeeman-Doppler imaging of UCD magnetic fields and our companion study of
+radio/X-ray flux ratios, we argue that this parameter is the magnetic field
+topology, and that the large scatter in UCD X-ray fluxes reflects the presence
+of two dynamo modes that produce distinct topologies.",1310.6758v2
+2016-03-09,Local Simulations of Instabilities Driven by Composition Gradients in the ICM,"The distribution of Helium in the intracluster medium (ICM) permeating galaxy
+clusters is not well constrained due to the very high plasma temperature.
+Therefore, the plasma is often assumed to be homogeneous. A non-uniform Helium
+distribution can however lead to biases when measuring key cluster parameters.
+This has motivated one-dimensional models that evolve the ICM composition
+assuming that the effects of magnetic fields can be parameterized or ignored.
+Such models for non-isothermal clusters show that Helium can sediment in the
+cluster core leading to a peak in concentration offset from the cluster center.
+The resulting profiles have recently been shown to be linearly unstable when
+the weakly-collisional character of the magnetized plasma is considered. In
+this paper, we present a modified version of the MHD code Athena, which makes
+it possible to evolve a weakly-collisional plasma subject to a gravitational
+field and stratified in both temperature and composition. We thoroughly test
+our implementation and confirm excellent agreement against several analytical
+results. In order to isolate the effects of composition, in this initial study
+we focus our attention on isothermal plasmas. We show that plasma
+instabilities, feeding off gradients in composition, can induce turbulent
+mixing and saturate by re-arranging magnetic field lines and alleviating the
+composition gradient. Composition profiles that increase with radius lead to
+instabilities that saturate by driving the average magnetic field inclination
+to roughly $45^{\circ}$. We speculate that this effect may alleviate the core
+insulation observed in homogeneous settings, with potential consequences for
+the associated cooling flow problem.",1603.05508v2
+2017-06-14,Intrinsic suppression of turbulence in linear plasma devices,"Plasma turbulence is the dominant transport mechanism for heat and particles
+in magnetized plasmas in linear devices and tokamaks, so the study of
+turbulence is important in limiting and controlling this transport. Linear
+devices provide an axial magnetic field that serves to confine a plasma in
+cylindrical geometry as it travels along the magnetic field from the source to
+the strike point. Due to perpendicular transport, the plasma density and
+temperature have a roughly Gaussian radial profile with gradients that drive
+instabilities, such as resistive drift-waves and Kelvin-Helmholtz. If unstable,
+these instabilities cause perturbations to grow resulting in saturated
+turbulence, increasing the cross-field transport of heat and particles. When
+the plasma emerges from the source, there is a time, $\tau_{\parallel}$, that
+describes the lifetime of the plasma based on parallel velocity and length of
+the device. As the plasma moves down the device, it also moves azimuthally
+according to $E\times B$ and diamagnetic velocities. There is a balance point
+in these parallel and perpendicular times that sets the stabilisation
+threshold. We simulate plasmas with a variety of parallel lengths and magnetic
+fields to vary the parallel and perpendicular lifetimes, respectively, and find
+that there is a clear correlation between the saturated RMS density
+perturbation level and the balance between these lifetimes. The threshold of
+marginal stability is seen to exist where
+$\tau_{\parallel}\approx11\tau_{\perp}$. This is also associated with the
+product $\tau_{\parallel}\gamma_*$, where $\gamma_*$ is the drift-wave linear
+growth rate, indicating that the instability must exist for roughly 100 times
+the growth time for the instability to enter the non-linear growth phase. We
+explore the root of this correlation and the implications for linear device
+design.",1706.04550v1
+2019-04-23,Simulating the Diverse Instabilities of Dust in Magnetized Gas,"Recently Squire & Hopkins showed that charged dust grains moving through
+magnetized gas under the influence of any external force (e.g. radiation
+pressure, gravity) are subject to a spectrum of instabilities. Qualitatively
+distinct instability families are associated with different Alfvenic or
+magnetosonic waves and drift or gyro motion. We present a suite of simulations
+exploring these instabilities, for grains in a homogeneous medium subject to an
+external acceleration. We vary parameters such as the ratio of Lorentz-to-drag
+forces on dust, plasma $\beta$, size scale, and acceleration. All regimes
+studied drive turbulent motions and dust-to-gas fluctuations in the saturated
+state, can rapidly amplify magnetic fields into equipartition with velocity
+fluctuations, and produce instabilities that persist indefinitely (despite
+random grain motions). Different parameters produce diverse morphologies and
+qualitatively different features in dust, but the saturated gas state can be
+broadly characterized as anisotropic magnetosonic or Alfvenic turbulence.
+Quasi-linear theory can qualitatively predict the gas turbulent properties.
+Turbulence grows from small to large scales, and larger-scale modes usually
+drive more vigorous gas turbulence, but dust velocity and density fluctuations
+are more complicated. In many regimes, dust forms structures (clumps,
+filaments, sheets) that reach extreme over-densities (up to $\gg 10^{9}$ times
+mean), and exhibit substantial sub-structure even in nearly-incompressible gas.
+These can be even more prominent at lower dust-to-gas ratios. In other regimes,
+dust self-excites scattering via magnetic fluctuations that isotropize and
+amplify dust velocities, producing fast, diffusive dust motions.",1904.11494v2
+2000-06-13,The inverse cascade and nonlinear alpha-effect in simulations of isotropic helical hydromagnetic turbulence,"A numerical model of isotropic homogeneous turbulence with helical forcing is
+investigated. The resulting flow, which is essentially the prototype of the
+alpha^2 dynamo of mean-field dynamo theory, produces strong dynamo action with
+an additional large scale field on the scale of the box (at wavenumber k=1;
+forcing is at k=5). This large scale field is nearly force-free and exceeds the
+equipartition value. As the magnetic Reynolds number R_m increases, the
+saturation field strength and the growth rate of the dynamo increase. However,
+the time it takes to built up the large scale field from equipartition to its
+final super-equipartition value increases with magnetic Reynolds number. The
+large scale field generation can be identified as being due to nonlocal
+interactions originating from the forcing scale, which is characteristic of the
+alpha-effect. Both alpha and turbulent magnetic diffusivity eta_t are
+determined simultaneously using numerical experiments where the mean-field is
+modified artificially. Both quantities are quenched in a R_m-dependent fashion.
+The evolution of the energy of the mean field matches that predicted by an
+alpha^2 dynamo model with similar alpha and eta_t quenchings. For this model an
+analytic solution is given which matches the results of the simulations. The
+simulations are numerically robust in that the shape of the spectrum at large
+scales is unchanged when changing the resolution from 30^3 to 120^3 meshpoints,
+or when increasing the magnetic Prandtl number (viscosity/magnetic diffusivity)
+from 1 to 100. Increasing the forcing wavenumber to 30 (i.e. increasing the
+scale separation) makes the inverse cascade effect more pronounced, although it
+remains otherwise qualitatively unchanged.",0006186v2
+2001-04-17,Centaurus A as the Source of ultra-high energy cosmic rays?,"We present numerical simulations for energy spectra and angular distributions
+of nucleons above 10^{19} eV injected by the radio-galaxy Centaurus A at a
+distance 3.4 Mpc and propagating in extra-galactic magnetic fields in the
+sub-micro Gauss range. We show that field strengths B~0.3 micro Gauss, as
+proposed by Farrar and Piran, cannot provide sufficient angular deflection to
+explain the observational data. A magnetic field of intensity ~1 micro Gauss
+could reproduce the observed large-scale isotropy and could marginally explain
+the observed energy spectrum. However, it would not readily account for the
+E=320 plusminus 93 EeV Fly's Eye event that was detected at an angle 136
+degrees away from Cen-A. Such a strong magnetic field also saturates
+observational upper limits from Faraday rotation observations and X-ray
+bremsstrahlung emission from the ambient gas (assuming equipartition of
+energy). This scenario may already be tested by improving magnetic field limits
+with existing instruments. We also show that high energy cosmic ray experiments
+now under construction will be able to detect the level of anisotropy predicted
+by this scenario. We conclude that for magnetic fields B~0.1-0.5 micro Gauss,
+considered as more reasonable for the local Supercluster environment, in all
+likelihood at least a few sources within ~10 Mpc from the Earth should
+contribute to the observed ultra high energy cosmic ray flux.",0104289v1
+2003-01-25,Non-normal and Stochastic Amplification in Turbulent Dynamo: Subcritical Case,"Our attention focuses on the stochastic dynamo equation with non-normal
+operator that give an insight into the role of stochastics and non-normality in
+the galactic magnetic field generation. The main point of this Letter is a
+discussion of the generation of a large-scale magnetic field that cannot be
+explained by traditional linear eigenvalue analysis. We present a simple
+stochastic model for the thin-disk axisymmetric $\alpha \Omega $ dynamo
+involving three factors: (a) the non-normality generated by differential
+rotation, (b) the nonlinearity reflecting how the magnetic field affects the
+turbulent dynamo coefficients, and (c) stochastic perturbations. We show that
+even for \textit{subcritical case,} there are three possible mechanisms for the
+generation of magnetic field. The first mechanism is a deterministic one that
+describes an interplay between transient growth and nonlinear saturation of the
+turbulent $\alpha -$effect and diffusivity. It turns out that the trivial state
+is nonlinearity unstable to small but finite initial perturbations. The second
+and third are the stochastic mechanisms that account for the interaction of
+non-normal effect generated by differential rotation and random additive and
+multiplicative fluctuations. In particular, we show that in \textit{subcritical
+case}the average magnetic energy can grow exponentially with time due to the
+multiplicative noise associated with $\alpha -$effect.",0301517v2
+2004-03-04,The two-dimensional magnetohydrodynamic Kelvin-Helmholtz instability: compressibility and large-scale coalescence effects,"The Kelvin-Helmholtz (KH) instability occurring in a single shear flow
+configuration that is embedded in a uniform flow-aligned magnetic field, is
+revisited by means of high resolution two-dimensional (2D) magnetohydrodynamic
+(MHD) simulations. First, the calculations extend previous studies of
+magnetized shear flows to a higher compressibility regime. The nonlinear
+evolution of an isolated KH billow emerging from the fastest growing linear
+mode for a convective sonic Mach number $M_{cs}=0.7$ layer is in many respects
+similar to its less compressible counterpart (Mach $M_{cs}=0.5$). In
+particular, the disruptive regime where locally amplified, initially weak
+magnetic fields, control the nonlinear saturation process is found for Alfv\'en
+Mach numbers $4\simlt M_A \simlt 30$. The most notable difference between
+$M_{cs}=0.7$ versus $M_{cs}=0.5$ layers is that higher density contrasts and
+fast magnetosonic shocklet structures are observed. Second, the use of adaptive
+mesh refinement allows to parametrically explore much larger computational
+domains, including up to 22 wavelengths of the linearly dominant mode. A strong
+process of large-scale coalescence is found, whatever the magnetic field
+regime. It proceeds through continuous pairing/merging events between adjacent
+vortices up to the point where the final large-scale vortical structure reaches
+the domain dimensions. This pairing/merging process is attributed to the growth
+of subharmonic modes and is mainly controlled by relative phase differences
+between them. These grid-adaptive simulations demonstrate that even in very
+weak magnetic field regimes ($M_A \simeq 30$), the large-scale KH coalescence
+process can trigger tearing-type reconnection events previously identified in
+cospatial current-vortex sheets.",0403125v1
+2004-07-18,Effects of differential and uniform rotation on nonlinear electromotive force in a turbulent flow,"An effect of the differential rotation on the nonlinear electromotive force
+in MHD turbulence is found. It includes a nonhelical $\alpha$ effect which is
+caused by a differential rotation, and it is independent of a hydrodynamic
+helicity. There is no quenching of this effect contrary to the quenching of the
+usual $\alpha$ effect caused by a hydrodynamic helicity. The nonhelical
+$\alpha$ effect vanishes when the rotation is constant on the cylinders which
+are parallel to the rotation axis. The mean differential rotation creates also
+the shear-current effect which changes its sign with the nonlinear growth of
+the mean magnetic field. However, there is no quenching of this effect. These
+phenomena determine the nonlinear evolution of the mean magnetic field. An
+effect of a uniform rotation on the nonlinear electromotive force is also
+studied. A nonlinear theory of the ${\bf \Omega} {\bf \times} \bar{\bf J}$
+effect is developed, and the quenching of the hydrodynamic part of the usual
+$\alpha$ effect which is caused by a uniform rotation and inhomogeneity of
+turbulence, is found. Other contributions of a uniform rotation to the
+nonlinear electromotive force are also determined. All these effects are
+studied using the spectral $\tau$ approximation (the third-order closure
+procedure). An axisymmetric mean-field dynamo in the spherical and cylindrical
+geometries is considered. The nonlinear saturation mechanism based on the
+magnetic helicity evolution is discussed. It is shown that this universal
+mechanism is nearly independent of the form of the flux of magnetic helicity,
+and it requires only a nonzero flux of magnetic helicity. Astrophysical
+applications of these effects are discussed.",0407375v3
+2007-03-22,General relativistic simulations of pasive-magneto-rotational core collapse with microphysics,"This paper presents results from axisymmetric simulations of
+magneto-rotational stellar core collapse to neutron stars in general relativity
+using the passive field approximation for the magnetic field. These simulations
+are performed using a new general relativistic numerical code specifically
+designed to study this astrophysical scenario. The code is based on the
+conformally-flat approximation of Einstein's field equations and conservative
+formulations of the magneto-hydrodynamics equations. The code has been recently
+upgraded to incorporate a tabulated, microphysical equation of state and an
+approximate deleptonization scheme. This allows us to perform the most
+realistic simulations of magneto-rotational core collapse to date, which are
+compared with simulations employing a simplified (hybrid) equation of state,
+widely used in the relativistic core collapse community. Furthermore,
+state-of-the-art (unmagnetized) initial models from stellar evolution are used.
+In general, stellar evolution models predict weak magnetic fields in the
+progenitors, which justifies our simplification of performing the computations
+under the approach that we call the passive field approximation for the
+magnetic field. Our results show that for the core collapse models with
+microphysics the saturation of the magnetic field cannot be reached within
+dynamical time scales by winding up the poloidal magnetic field into a toroidal
+one. We estimate the effect of other amplification mechanisms including the
+magneto-rotational instability (MRI) and several types of dynamos.",0703597v2
+1998-09-07,Non-Dissipative Logic Device NOT Based on Two Coupled Quantum Dots,"Non-dissipative dynamics of interacting electrons in two tunnel-coupled
+quantum dots is studied theoretically within the framework of the Hubbard
+model. Various values of intra-dot Coulomb repulsion energy $U$ and inter-dot
+tunneling energy $V$ are considered, which correspond to various size of the
+dots and to various distance between them. In the ground state, the average
+value of the spin projection (magnetic moment) at each dot is zero. The input
+signal (the local external magnetic field $H$) applied to one of the dots at a
+time $t=0$ causes the electronic subsystem to evolve in such a way that
+magnetic moments of quantum dots become oriented in the opposite directions at
+any time $t>0$. For any set of $U$ and $V$, there exist optimal values of $H$
+and $t$ which maximize the absolute values of magnetic moments at both dots,
+and magnetic moments become almost saturated. Thus, the antiferromagnetic-like
+spin ordering can be realized at the stage of coherent temporal evolution, well
+before the relaxation to a new ground state at the sacrifice of inelastic
+processes. This effect (""dynamical antiferromagnetism"") may be used for
+implementation of a logic function NOT in an extremely short time. A
+possibility to use the arrays of quantum dots as high-speed single-electron
+devices of new generation is discussed.",9809112v1
+2003-02-25,Magnetic Phase Diagram of GdNi2B2C: Two-ion Magnetoelasticity and Anisotropic Exchange Couplings,"Extensive magnetization and magnetostriction measurements were carried out on
+a single crystal of GdNi2B2C along the main tetragonal axes. Within the
+paramagnetic phase, the magnetic and strain susceptibilities revealed a weak
+anisotropy in the exchange couplings and two-ion tetragonal-preserving
+alpha-strain modes. Within the ordered phase, magnetization and
+magnetostriction revealed a relatively strong orthorhombic distortion mode and
+rich field-temperature phase diagrams. For H//(100) phase diagram, three
+field-induced transformations were observed, namely, at: Hd(T), related to the
+domain alignment; Hr(T), associated with reorientation of the moment towards
+the c-axis; and Hs(T), defining the saturation process wherein the exchange
+field is completely counterbalanced. On the other hand, For H//(001) phase
+diagram, only two field-induced transformations were observed, namely at: Hr(T)
+and Hs(T). For both phase diagrams, Hs(T) follows the relation
+Hs[1-(T/Tn)^2]^(1/2)kOe with Hs(T-->0)=128.5(5) kOe and Tn(H=0)=19.5 K. In
+contrast, the thermal evolution of Hr(T) along the c-axis (much simpler than
+along the a-axis) follows the relation Hr[1-T/Tr]^(1/3) kOe where
+Hr(T-->0)=33.5(5) kOe and Tr(H=0)=13.5 K. It is emphasized that the
+magnetoelastic interaction and the anisotropic exchange coupling are important
+perturbations and therefore should be explicitly considered if a complete
+analysis of the magnetic properties of the borocarbides is desired.",0302521v1
+2003-10-14,"Exchange anisotropy, disorder and frustration in diluted, predominantly ferromagnetic, Heisenberg spin systems","Motivated by the recent suggestion of anisotropic effective exchange
+interactions between Mn spins in Ga$_{1-x}$Mn$_x$As (arising as a result of
+spin-orbit coupling), we study their effects in diluted Heisenberg spin
+systems. We perform Monte Carlo simulations on several phenomenological model
+spin Hamiltonians, and investigate the extent to which frustration induced by
+anisotropic exchanges can reduce the low temperature magnetization in these
+models and the interplay of this effect with disorder in the exchange. In a
+model with low coordination number and purely ferromagnetic (FM) exchanges, we
+find that the low temperature magnetization is gradually reduced as exchange
+anisotropy is turned on. However, as the connectivity of the model is
+increased, the effect of small-to-moderate anisotropy is suppressed, and the
+magnetization regains its maximum saturation value at low temperatures unless
+the distribution of exchanges is very wide. To obtain significant suppression
+of the low temperature magnetization in a model with high connectivity, as is
+found for long-range interactions, we find it necessary to have both
+ferromagnetic and antiferromagnetic (AFM) exchanges (e.g. as in the RKKY
+interaction). This implies that disorder in the sign of the exchange
+interaction is much more effective in suppressing magnetization at low
+temperatures than exchange anisotropy.",0310322v1
+2006-05-19,Spin-flop transition in antiferromagnetic multilayers,"A comprehensive theoretical investigation on the field-driven reorientation
+transitions in uniaxial multilayers with antiferromagnetic coupling is
+presented. It is based on a complete survey of the one-dimensional solutions
+for the basic phenomenological (micromagnetic) model that describes the
+magnetic properties of finite stacks made from ferromagnetic layers coupled
+antiferromagnetically through spacer layers. The general structure of the phase
+diagrams is analysed. At a high ratio of uniaxial anisotropy to
+antiferromagnetic interlayer exchange, only a succession of collinear magnetic
+states is possible. With increasing field first-order (metamagnetic)
+transitions occur from the antiferromagnetic ground-state to a set of
+degenerate ferrimagnetic states and to the saturated ferromagnetic state. At
+low anisotropies, a first-order transition from the antiferromagnetic
+ground-state to an inhomogeneous spin-flop state occurs. Between these two
+regions, transitional magnetic phases occupy the range of intermediate
+anisotropies. Detailed and quantitative phase diagrams are given for the basic
+model of antiferromagnetic multilayer systems with N = 2 to 16 layers. The
+connection of the phase diagrams with the spin-reorientation transitions in
+bulk antiferromagnets is discussed. The limits of low anisotropy and large
+numbers of layers are analysed by two different representations of the magnetic
+energy, namely, in terms of finite chains of staggered vectors and in a general
+continuum form. It is shown that the phenomena widely described as ``surface
+spin-flop'' are driven only by the cut exchange interactions and the
+non-compensated magnetic moment at the surface layers of a stacked
+antiferromagnetic system.",0605493v1
+2004-09-20,Spontaneous symmetry breaking and response functions,"We study the quantum phase transition occurring in an infinite homogeneous
+system of spin 1/2 fermions in a non-relativistic context. As an example we
+consider neutrons interacting through a simple spin-spin Heisenberg force. The
+two critical values of the coupling strength -- signaling the onset into the
+system of a finite magnetization and of the total magnetization, respectively
+-- are found and their dependence upon the range of the interaction is
+explored. The spin response function of the system in the region where the
+spin-rotational symmetry is spontaneously broken is also studied. For a
+ferromagnetic interaction the spin response along the direction of the
+spontaneous magnetization occurs in the particle-hole continuum and displays,
+for not too large momentum transfers, two distinct peaks. The response along
+the direction orthogonal to the spontaneous magnetization displays instead,
+beyond a softened and depleted particle-hole continuum, a collective mode to be
+identified with a Goldstone boson of type II. Notably, the random phase
+approximation on a Hartree-Fock basis accounts for it, in particular for its
+quadratic -- close to the origin -- dispersion relation. It is shown that the
+Goldstone boson contributes to the saturation of the energy-weighted sum rule
+for ~25% when the system becomes fully magnetized (that is in correspondence of
+the upper critical value of the interaction strength) and continues to grow as
+the interaction strength increases.",0409039v1
+2009-06-24,Turbulent resistivity driven by the magnetorotational instability,"We measure the turbulent resistivity in the nonlinear regime of the MRI, and
+evaluate the turbulent magnetic Prandtl number. We perform a set of numerical
+simulations with the Eulerian finite volume codes Athena and Ramses in the
+framework of the shearing box model. We consider models including explicit
+dissipation coefficients and magnetic field topologies such that the net
+magnetic flux threading the box in both the vertical and azimuthal directions
+vanishes. We first demonstrate good agreement between the two codes by
+comparing the properties of the turbulent states in simulations having
+identical microscopic diffusion coefficients (viscosity and resistivity). We
+find the properties of the turbulence do not change when the box size is
+increased in the radial direction, provided it is elongated in the azimuthal
+direction. To measure the turbulent resistivity in the disk, we impose a fixed
+electromotive force on the flow and measure the amplitude of the saturated
+magnetic field that results. We obtain a turbulent resistivity that is in rough
+agreement with mean field theories like the Second Order Smoothing
+Approximation. The numerical value translates into a turbulent magnetic Prandtl
+number Pm_t of order unity. Pm_t appears to be an increasing function of the
+forcing we impose. It also becomes smaller as the box size is increased in the
+radial direction, in good agreement with previous results obtained in very
+large boxes. Our results are in general agreement with other recently published
+papers studying the same problem but using different methodology. Thus, our
+conclusion that Pm_t is of order unity appears robust.",0906.4422v2
+2009-09-01,Turbulence and Mixing in the Intracluster Medium,"The intracluster medium (ICM) is stably stratified in the hydrodynamic sense
+with the entropy $s$ increasing outwards. However, thermal conduction along
+magnetic field lines fundamentally changes the stability of the ICM, leading to
+the ""heat-flux buoyancy instability"" when $dT/dr>0$ and the ""magnetothermal
+instability"" when $dT/dr<0$. The ICM is thus buoyantly unstable regardless of
+the signs of $dT/dr$ and $ds/dr$. On the other hand, these
+temperature-gradient-driven instabilities saturate by reorienting the magnetic
+field (perpendicular to $\hat{\bf r}$ when $dT/dr>0$ and parallel to $\hat{\bf
+r}$ when $dT/dr<0$), without generating sustained convection. We show that
+after an anisotropically conducting plasma reaches this nonlinearly stable
+magnetic configuration, it experiences a buoyant restoring force that resists
+further distortions of the magnetic field. This restoring force is analogous to
+the buoyant restoring force experienced by a stably stratified adiabatic
+plasma. We argue that in order for a driving mechanism (e.g, galaxy motions or
+cosmic-ray buoyancy) to overcome this restoring force and generate turbulence
+in the ICM, the strength of the driving must exceed a threshold, corresponding
+to turbulent velocities $\gtrsim 10 -100 {km/s}$. For weaker driving, the ICM
+remains in its nonlinearly stable magnetic configuration, and turbulent mixing
+is effectively absent. We discuss the implications of these findings for the
+turbulent diffusion of metals and heat in the ICM.",0909.0270v1
+2010-06-17,Magnetic helicity flux in the presence of shear,"Magnetic helicity has risen to be a major player in dynamo theory, with the
+helicity of the small-scale field being linked to the dynamo saturation process
+for the large-scale field. It is a nearly conserved quantity, which allows its
+evolution equation to be written in terms of production and flux terms. The
+flux term can be decomposed in a variety of fashions. One particular
+contribution that has been expected to play a significant role in dynamos in
+the presence of mean shear was isolated by Vishniac & Cho (2001, ApJ 550, 752).
+Magnetic helicity fluxes are explicitly gauge dependent however, and the
+correlations that have come to be called the Vishniac-Cho flux were determined
+in the Coulomb gauge, which turns out to be fraught with complications in
+shearing systems. While the fluxes of small-scale helicity are explicitly gauge
+dependent, their divergences can be gauge independent. We use this property to
+investigate magnetic helicity fluxes of small-scale field through direct
+numerical simulations in a shearing-box system and find that in a numerically
+usable gauge the divergence of the small-scale helicity flux vanishes, while
+the divergence of the Vishniac-Cho flux remains finite. We attribute this
+seeming contradiction to the existence of horizontal fluxes of small-scale
+magnetic helicity with finite divergences even in our shearing-periodic domain.",1006.3549v2
+2010-09-03,Magnetic and transport properties of the spin-state disordered oxide La0.8Sr0.2Co_{1-x}Rh_xO_{3-δ},"We report measurements and analysis of magnetization, resistivity and
+thermopower of polycrystalline samples of the perovskite-type Co/Rh oxide
+La$_{0.8}$Sr$_{0.2}$Co$_{1-x}$Rh$_x$O$_{3-\delta}$. This system constitutes a
+solid solution for a full range of $x$,in which the crystal structure changes
+from rhombohedral to orthorhombic symmetry with increasing Rh content $x$. The
+magnetization data reveal that the magnetic ground state immediately changes
+upon Rh substitution from ferromagnetic to paramagnetic with increasing $x$
+near 0.25, which is close to the structural phase boundary. We find that one
+substituted Rh ion diminishes the saturation moment by 9 $\mu_B$, which implies
+that one Rh$^{3+}$ ion makes a few magnetic Co$^{3+}$ ions nonmagnetic (the low
+spin state), and causes disorder in the spin state and the highest occupied
+orbital. In this disordered composition ($0.05\le x \le 0.75$), we find that
+the thermopower is anomalously enhanced below 50 K. In particular, the
+thermopower of $x$=0.5 is larger by a factor of 10 than those of $x$=0 and 1,
+and the temperature coefficient reaches 4 $\mu$V/K$^2$ which is as large as
+that of heavy-fermion materials such as CeRu$_2$Si$_2$.",1009.0728v2
+2011-08-09,H2O Maser Polarization of the Water Fountains IRAS 15445-5449 and IRAS 18043-2116,"We present the morphology and linear polarization of the 22-GHz H2O masers in
+the high-velocity outflow of two post-AGB sources, d46 (IRAS 15445-5449) and
+b292 (IRAS 18043-2116). The observations were performed using The Australia
+Telescope Compact Array. Different levels of saturated maser emission have been
+detected for both sources. We also present the mid-infrared image of d46
+overlaid with the distribution of the maser features that we have observed in
+the red-shifted lobe of the bipolar structure. The relative position of the
+observed masers and a previous radio continuum observation suggests that the
+continnum is produced along the blue-shifted lobe of the jet. It is likely due
+to synchrontron radiation, implying the presence of a strong magnetic field in
+the jet. The fractional polarization levels measured for the maser features of
+d46 indicate that the polarization vectors are tracing the poloidal component
+of the magnetic field in the emitting region. For the H2O masers of b292 we
+have measured low levels of fractional linear polarization. The linear
+polarization in the H2O maser region of this source likely indicates a dominant
+toroidal or poloidal magnetic field component. Since circular polarization was
+not detected it is not possible to determine the magnetic field strength.
+However, we present a 3-sigma evaluation of the upper limit intensity of the
+magnetic field in the maser emitting regions of both observed sources.",1108.1911v1
+2011-09-28,Numerical Simulations of Driven Supersonic Relativistic MHD Turbulence,"Models for GRB outflows invoke turbulence in relativistically hot magnetized
+fluids. In order to investigate these conditions we have performed
+high-resolution three-dimensional numerical simulations of relativistic
+magneto-hydrodynamical (RMHD) turbulence. We find that magnetic energy is
+amplified to several percent of the total energy density by turbulent twisting
+and folding of magnetic field lines. Values of epsilon_B near 1% are thus
+naturally expected. We study the dependence of saturated magnetic field energy
+fraction as a function of Mach number and relativistic temperature. We then
+present power spectra of the turbulent kinetic and magnetic energies. We also
+present solenoidal (curl-like) and dilatational (divergence-like) power spectra
+of kinetic energy. We propose that relativistic effects introduce novel
+couplings between these spectral components. The case we explore in most detail
+is for equal amounts of thermal and rest mass energy, corresponding to
+conditions after collisions of shells with relative Lorentz factors of several.
+These conditions are relevant in models for internal shocks, for the late
+afterglow phase, for cocoon material along the edge of a relativistic jet as it
+propagates through a star, as well neutron stars merging with each other and
+with black hole companions. We find that relativistic turbulence decays
+extremely quickly, on a sound crossing time of an eddy. Models invoking
+sustained relativistic turbulence to explain variability in GRB prompt emission
+are thus strongly disfavored unless a persistant driving of the turbulence is
+maintained for the duration of the prompt emission.",1109.6294v1
+2011-10-19,Current helicity of active regions as a tracer of large-scale solar magnetic helicity,"We demonstrate that the current helicity observed in solar active regions
+traces the magnetic helicity of the large-scale dynamo generated field. We use
+an advanced 2D mean-field dynamo model with dynamo saturation based on the
+evolution of the magnetic helicity and algebraic quenching. For comparison, we
+also studied a more basic 2D mean-field dynamo model with simple algebraic
+alpha quenching only. Using these numerical models we obtained butterfly
+diagrams both for the small-scale current helicity and also for the large-scale
+magnetic helicity, and compared them with the butterfly diagram for the current
+helicity in active regions obtained from observations. This comparison shows
+that the current helicity of active regions, as estimated by $-{\bf A \cdot B}$
+evaluated at the depth from which the active region arises, resembles the
+observational data much better than the small-scale current helicity calculated
+directly from the helicity evolution equation. Here ${\bf B}$ and ${\bf A}$ are
+respectively the dynamo generated mean magnetic field and its vector potential.
+A theoretical interpretation of these results is given.",1110.4387v2
+2011-12-12,Self-similar solutions of viscous and resistive ADAFs with thermal conduction,"We have studied the effects of thermal conduction on the structure of viscous
+and resistive advection-dominated accretion flows (ADAFs). The importance of
+thermal conduction on hot accretion flow is confirmed by observations of hot
+gas that surrounds Sgr A$^*$ and a few other nearby galactic nuclei. In this
+research, thermal conduction is studied by a saturated form of it, as is
+appropriated for weakly-collisional systems. It is assumed the viscosity and
+the magnetic diffusivity are due to turbulence and dissipation in the flow. The
+viscosity also is due to angular momentum transport. Here, the magnetic
+diffusivity and the kinematic viscosity are not constant and vary by position
+and $\alpha$-prescription is used for them. The govern equations on system have
+been solved by the steady self-similar method. The solutions show the radial
+velocity is highly subsonic and the rotational velocity behaves sub-Keplerian.
+The rotational velocity for a specific value of the thermal conduction
+coefficient becomes zero. This amount of conductivity strongly depends on
+magnetic pressure fraction, magnetic Prandtl number, and viscosity parameter.
+Comparison of energy transport by thermal conduction with the other energy
+mechanisms implies that thermal conduction can be a significant energy
+mechanism in resistive and magnetized ADAFs. This property is confirmed by
+non-ideal magnetohydrodynamics (MHD) simulations.",1112.2678v1
+2012-09-24,Diffusive shock acceleration with magnetic field amplification and Alfvenic drift,"We explore how wave-particle interactions affect diffusive shock acceleration
+(DSA) at astrophysical shocks by performing time-dependent kinetic simulations,
+in which phenomenological models for magnetic field amplification (MFA),
+Alfvenic drift, thermal leakage injection, Bohm-like diffusion, and a free
+escape boundary are implemented. If the injection fraction of cosmic-ray (CR)
+particles is greater than 2x10^{-4}, for the shock parameters relevant for
+young supernova remnants, DSA is efficient enough to develop a significant
+shock precursor due to CR feedback, and magnetic field can be amplified up to a
+factor of 20 via CR streaming instability in the upstream region. If scattering
+centers drift with Alfven speed in the amplified magnetic field, the CR energy
+spectrum can be steepened significantly and the acceleration efficiency is
+reduced. Nonlinear DSA with self-consistent MFA and Alfvenic drift predicts
+that the postshock CR pressure saturates roughly at 10 % of the shock ram
+pressure for strong shocks with a sonic Mach number ranging 20< M_s< 100. Since
+the amplified magnetic field follows the flow modification in the precursor,
+the low energy end of the particle spectrum is softened much more than the high
+energy end. As a result, the concave curvature in the energy spectra does not
+disappear entirely even with the help of Alfvenic drift. For shocks with a
+moderate Alfven Mach number (M_A<10), the accelerated CR spectrum can become as
+steep as E^{-2.1}-E^{-2.3}, which is more consistent with the observed CR
+spectrum and gamma-ray photon spectrum of several young supernova remnants.",1209.5203v1
+2012-12-05,Columnar antiferromagnetic order and spin supersolid phase on the extended Shastry-Sutherland lattice,"We use large scale quantum Monte Carlo simulations to study an extended
+version of the canonical Shastry-Sutherland model -- including additional
+interactions and exchange anisotropy -- over a wide range of interaction
+parameters and an applied magnetic field. The model is appropriate for
+describing the low energy properties of some members of the rare earth
+tetraborides. Working in the limit of large Ising-like exchange anisotropy, we
+demonstrate the stabilization of columnar antiferromagnetic order in the ground
+state at zero field and an extended magnetization plateau at 1/2 the saturation
+magnetization in the presence of an applied longitudinal magnetic field --
+qualitatively similar to experimentally observed low-temperature phases in
+ErB$_4$. Our results show that for an optimal range of exchange parameters, a
+spin supersolid ground state is realized over a finite range of applied field
+between the columnar antiferromagnetic phase and the magnetization plateau. The
+full momentum dependence of the longitudinal and transverse components of the
+static structure factor is calculated in the spin supersolid phase to
+demonstrate the simultaneous existence of diagonal and off-diagonal long-range
+order. Our results will provide crucial guidance in designing further
+experiments to search for the interesting spin supersolid phase in ErB$_4$.",1212.0926v2
+2013-04-17,Magnetic field amplification by the small-scale dynamo in the early Universe,"In this paper we show that the Universe is already strongly magnetized at
+very early epochs during cosmic evolution. Our calculations are based on the
+efficient amplification of weak magnetic seed fields, which are unavoidably
+present in the early Universe, by the turbulent small-scale dynamo. We identify
+two mechanisms for the generation of turbulence in the radiation dominated
+epoch where velocity fluctuations are produced by the primordial density
+perturbation and by possible first-order phase transitions at the electroweak
+or QCD scales. We show that all the necessities for the small-scale dynamo to
+work are fulfilled. Hence, this mechanism, operating due to primordial density
+perturbations, guarantees fields with comoving field strength
+$B_0\sim10^{-6}\varepsilon^{1/2}$ nG on scales up to $\lambda_c\sim0.1$ pc,
+where $\varepsilon$ is the saturation efficiency. The amplification of magnetic
+seed fields could be even larger if there are first-order phase transitions in
+the early Universe. Where, on scales up to $\lambda_c\sim100$ pc, the comoving
+field strength due to this mechanism will be $B_0\sim10^{-3}\varepsilon^{1/2}$
+nG at the present time. Such fields, albeit on small scales, can play an
+important role in structure formation and could provide an explanation to the
+apparently observed magnetic fields in the voids of the large-scale structure.",1304.4723v2
+2013-06-18,Magnetic anisotropy and lattice dynamics in FeAs studied by Mössbauer spectroscopy,"Iron mono-arsenide in the powder form has been investigated by transmission
+57Fe Moessbauer spectroscopy in the temperature range 4.2 - 1000 K. Additional
+spectra have been obtained at 20 K and 100 K applying external magnetic field
+of 7 T. It was found that the spin spiral propagating along the c-axis leads to
+the complex variation of the hyperfine magnetic field amplitude with the spin
+orientation varying in the a-b plane. The magnitude of the hyperfine field
+pointing in the direction of the local magnetic moment depends on the
+orientation of this moment in the a-b plane. Patterns are vastly different for
+iron located in the [0 k 0] positions and for iron in the [0 k+1/2 0] positions
+within the orthorhombic cell set to the Pnma symmetry. Lattice softens upon
+transition to the paramagnetic state at 69.2 K primarily in the a-c plane as
+seen by iron atoms. This effect is quite large considering lack of the
+structural transition. Two previously mentioned iron sites are discernible in
+the paramagnetic region till 300 K by different electron densities on the iron
+nuclei. The anisotropy of the iron vibrations developed at the transition to
+the paramagnetic state increases with the temperature in accordance with the
+harmonic approximation, albeit tends to saturation at high temperatures
+indicating gradual onset of the quasi-harmonic conditions. It seems that
+neither hyperfine fields nor magnetic moments are correct order parameters in
+light of the determined static critical exponents. Sample starts to loose
+arsenic at about 1000 K and under vacuum.",1306.4170v3
+2013-07-10,Magnetic field generation in a jet-sheath plasma via the kinetic Kelvin-Helmholtz instability,"We have investigated generation of magnetic fields associated with velocity
+shear between an unmagnetized relativistic jet and an unmagnetized sheath
+plasma. We have examined the strong magnetic fields generated by kinetic shear
+(Kelvin-Helmholtz) instabilities. Compared to the previous studies using
+counter-streaming performed by Alves et al. (2012), the structure of KKHI of
+our jet-sheath configuration is slightly different even for the global
+evolution of the strong transverse magnetic field. In our simulations the major
+components of growing modes are the electric field $E_{\rm z}$ and the magnetic
+field $B_{\rm y}$. After the $B_{\rm y}$ component is excited, an induced
+electric field $E_{\rm x}$ becomes significant. However, other field components
+remain small. We find that the structure and growth rate of KKHI with mass
+ratios $m_{\rm i}/m_{\rm e} = 1836$ and $m_{\rm i}/m_{\rm e} = 20$ are similar.
+In our simulations saturation in the nonlinear stage is not as clear as in
+counter-streaming cases. The growth rate for a mildly-relativistic jet case
+($\gamma_{\rm j} = 1.5$) is larger than for a relativistic jet case
+($\gamma_{\rm j} = 15$).",1307.2928v1
+2013-09-27,Structural and magnetic properties of Cr-diluted CoFeB,"The crystallization process and the magnetization of Cr diluted CoFeB was
+investigated in both ribbon samples and thin film samples with Cr content up to
+30 at. %. A primary crystallization of bcc phase from an amorphous precursor in
+ribbon samples was observed when the annealing temperature rose to between 421
+oC and 456 oC, followed by boron segregation at temperatures between 518 oC and
+573 oC. The two onset crystallization temperatures showed strong dependences on
+both Cr and B concentrations. The impact of Cr concentration on the magnetic
+properties including a reduced saturation magnetization and an enhanced
+coercive field was also observed. The magnetizations of both ribbon samples and
+thin film samples were well fitted using the generalized Slater-Pauling curve
+with modified moments for B (-0.94 {\mu}B) and Cr (-3.6 {\mu}B). Possible
+origins of the enhanced coercive field were also discussed. We also achieved a
+damping parameter in CoFeCrB thin films at the same level as Co40Fe40B20, much
+lower than the value reported for CoFeCrB films previously. The results suggest
+a possible advantage of CoFeCrB in reducing the critical switching current
+density in Spin Transfer Torque Random Access Memory (STT-RAM).",1309.7331v1
+2013-10-14,Magnetic fields during the formation of supermassive black holes,"Observations of quasars at $\rm z> 6$ report the existence of a billion solar
+mass black holes. Comprehending their formation in such a short time scale is a
+matter of ongoing research. One of the most promising scenarios to assemble
+supermassive black holes is a monolithic collapse of protogalactic gas clouds
+in atomic cooling halos with $\rm T_{vir} \geq 10^{4} K$. In this article, we
+study the amplification and impact of magnetic fields during the formation of
+seed black holes in massive primordial halos. We perform high resolution
+cosmological magnetohydrodynamics simulations for four distinct halos and
+follow their collapse for a few free-fall times until the simulations reach a
+peak density of $\rm 7 \times 10^{-10} g/cm^{3}$. Our findings show that
+irrespective of the initial seed field, the magnetic field strength reaches a
+saturated state in the presence of strong accretion shocks. Under such
+conditions, the growth time becomes very short and amplification occurs rapidly
+within a small fraction of the free-fall time. We find that the presence of
+such strong magnetic fields provides additional support against gravity and
+helps in suppressing fragmentation. Massive clumps of a few hundred solar
+masses are formed at the end of our simulations and high accretion rates of
+$\rm 1 M_{\odot}/yr$ are observed. We expect that in the presence of such
+accretion rates, the clumps will grow to form supermassive stars of $\rm \sim
+10^{5} M_{\odot}$. Overall, the role of the magnetic fields seems supportive
+for the formation of massive black holes.",1310.3680v2
+2013-12-11,Distinct magnetic phase transition at the surface of an antiferromagnet,"In the majority of magnetic systems the surface is required to order at the
+same temperature as the bulk. In the present study, we report a distinct and
+unexpected surface magnetic phase transition, uniquely at a lower temperature
+than the N\'eel temperature. Employing grazing incidence X-ray resonant
+magnetic scattering we have observed the near surface behavior of uranium
+dioxide. UO$_2$ is a non-collinear, triple-q, antiferromagnet with the U ions
+on an face-centered-cubic lattice. Theoretical investigations establish that at
+the surface the energy increase, due to the lost bonds, reduces when the spins
+near the surface rotate, gradually losing their normal to the surface
+component. At the surface the lowest-energy spin configuration has a double-q
+(planar) structure. With increasing temperature, thermal fluctuations saturate
+the in-plane crystal field anisotropy at the surface, leading to soft
+excitations that have ferromagnetic $XY$ character and are decoupled from the
+bulk. The structure factor of a finite two-dimensional $XY$ model, fits the
+experimental data well for several orders of magnitude of the scattered
+intensity. Our results support a distinct magnetic transition at the surface in
+the Kosterlitz-Thouless universality class.",1312.3136v2
+2014-08-07,Magnetic Torque of Microfabricated Elements and Magnetotactic Bacteria,"We present a thorough theoretical analysis of the magnetic torque on
+microfabricated elements with dimensions in the range of 100 to 500 {\mu}m and
+magneto-somes of magnetotactic bacteria of a few {\mu}m length. We derive
+simple equations for field dependent torque and magnetic shape anisotropy that
+can be readily used to replace the crude approximations commonly used. We
+illustrate and verify the theory on microfabricated elements and magnetotactic
+bacteria, by field depedent torque magnetometry and by observing their rotation
+in water under application of a rotating magnetic field. The maximum rotation
+frequency of the largest microfabricated elements agrees within error
+boundaries with theory. For smaller, and especially thinner, elements the
+measured frequencies are a factor of three to four too low. We suspect this is
+caused by incomplete saturation of the magnetisation in the elements, which is
+not incorporated in our model. The maximum rotation frequency of magnetotactic
+bacteria agrees with our model within error margins, which are however quite
+big due to the large spread in bacteria morphology. The model presented
+provides a solid basis for the analysis of experiments with magnetic objects in
+liquid, which is for instance the case in the field of medical microrobotics.",1408.1570v1
+2015-08-28,Spin-S Kagome quantum antiferromagnets in a field with tensor networks,"Spin-$S$ Heisenberg quantum antiferromagnets on the Kagome lattice offer,
+when placed in a magnetic field, a fantastic playground to observe exotic
+phases of matter with (magnetic analogs of) superfluid, charge, bond or nematic
+orders, or a coexistence of several of the latter. In this context, we have
+obtained the (zero temperature) phase diagrams up to $S=2$ directly in the
+thermodynamic limit thanks to infinite Projected Entangled Pair States (iPEPS),
+a tensor network numerical tool. We find incompressible phases characterized by
+a magnetization plateau vs field and stabilized by spontaneous breaking of
+point group or lattice translation symmetry(ies). The nature of such phases may
+be semi-classical, as the plateaus at $\frac{1}{3}$th, $(1-\frac{2}{9S})$th and
+$(1-\frac{1}{9S})$th of the saturated magnetization (the latter followed by a
+macroscopic magnetization jump), or fully quantum as the spin-$\frac{1}{2}$
+$\frac{1}{9}$-plateau exhibiting coexistence of charge and bond orders. Upon
+restoration of the spin rotation $U(1)$ symmetry a finite compressibility
+appears, although lattice symmetry breaking persists. For integer spin values
+we also identify spin gapped phases at low enough field, such as the $S=2$
+(topologically trivial) spin liquid with no symmetry breaking, neither spin nor
+lattice.",1508.07189v3
+2015-08-31,Growth and Characterization of Ce- Substituted Nd2Fe14B Single Crystals,"Single crystals of (Nd1-xCex)2Fe14B are grown out of Fe-(Nd,Ce) flux.
+Chemical and structural analysis of the crystals indicates that
+(Nd1-xCex)2Fe14B forms a solid solution until at least x = 0.38 with a
+Vegard-like variation of the lattice constants with x. Refinements of single
+crystal neutron diffraction data indicate that Ce has a slight site preference
+(7:3) for the 4g rare earth site over the 4f site. Magnetization measurements
+show that for x = 0.38 the saturation magnetization at 400 K, a temperature
+important to applications, falls from 29.8 for the parent Nd2Fe14B to 27.6
+(mu)B/f.u., the anisotropy field decreases from 5.5 T to 4.7 T, and the Curie
+temperature decreases from 586 to 543 K. First principles calculations carried
+out within density functional theory are used to explain the decrease in
+magnetic properties due to Ce substitution. Though the presence of the
+lower-cost and more abundant Ce slightly affects these important magnetic
+characteristics, this decrease is not large enough to affect a multitude of
+applications. Ce-substituted Nd2Fe14B is therefore a potential high-performance
+permanent magnet material with substantially reduced Nd content.",1508.07792v1
+2015-12-10,Investigation of magnetic characteristics of oxygen adsorbed YbFe2As2 single crystals,"Recent discovery of superconductivity in iron pnictides had attracted immense
+attention of the scientific community. The parent compounds were spin density
+wave (SDW) metals unlike the high-TC superconductors which were Mott
+insulators. In this present study, we synthesized single crystal of a new
+compound YbFe2As2 by using high temperature solution growth technique without
+flux. The YbFe2As2 single crystals had been systematically characterized by
+energy dispersive X-ray analysis (EDAX). The presence of oxygen was found by
+EDAX on the surfaces of grown YbFe2As2 single crystals which had been kept in
+air ambience for few months. The measurement of magnetization (M) versus
+temperature (T) using SQUID at constant magnetic field (H = 100 Oe) for
+YbFe2As2 had revealed an occurrence of sharp slope change around 140 K which
+was the known SDW transition temperature for the parent compound BaFe2As2. An
+additional slope change had been observed around 40 K. M vs T data at H= 10000
+Oe had exhibited paramagnetic behavior. Result of M versus H measurements for
+YbFe2As2 at 2 K had shown that the saturation had not been achieved at H =
+80000 Oe. We had carried out magnetization measurements for oxygen adsorbed
+YbFe2As2 (YbFe2As2 : O2 ) and BaFe2As2 (BaFe2As2 : O2) for comparative study
+also.",1512.03197v1
+2016-02-03,"Robust tunability of magnetorestance in Half-Heusler RPtBi (R = Gd, Dy, Tm, and Lu) compounds","We present the magnetic field dependencies of transport properties for
+$R$PtBi ($R$ = Gd, Dy, Tm, and Lu) half-Heusler compounds. Temperature and
+field dependent resistivity measurements of high quality $R$PtBi single
+crystals reveal an unusually large, non-saturating magnetoresistance (MR) up to
+300 K under a moderate magnetic field of $H$ = 140 kOe. At 300 K, the large MR
+effect decreases as the rare-earth is traversed from Gd to Lu and the magnetic
+field dependence of MR shows a deviation from the conventional $H^{2}$
+behavior. The Hall coefficient ($R_{H}$) for $R$ = Gd indicates a sign change
+around 120 K, whereas $R_{H}$ curves for $R$ = Dy, Tm, and Lu remain positive
+for all measured temperatures. At 300 K, the Hall resistivity reveals a
+deviation from the linear field dependence for all compounds. Thermoelectric
+power measurements on this family show strong temperature and magnetic field
+dependencies which are consistent with resistivity measurements. A highly
+enhanced thermoelectric power under applied magnetic field is observed as high
+as $\sim$100 $\mu$V/K at 140 kOe. Analysis of the transport data in this series
+reveals that the rare-earth-based Half-Husler compounds provide opportunities
+to tune MR effect through lanthanide contraction and to elucidate the mechanism
+of non-trivial MR.",1602.01194v1
+2016-07-01,Size dependent magnetic and electrical properties of Ba-doped nanocrystalline BiFeO$_3$,"Improvement in magnetic and electrical properties of multiferroic BiFeO$_3$
+in conjunction with their dependence on particle size is crucial due to its
+potential applications in multifunctional miniaturized devices. In this
+investigation, we report a study on particle size dependent structural,
+magnetic and electrical properties of sol-gel derived
+Bi$_{0.9}$Ba$_{0.1}$FeO$_3$ nanoparticles of different sizes ranging from
+$\sim$ 12 to 49 nm. The substitution of Bi by Ba significantly suppresses
+oxygen vacancies, reduces leakage current density and Fe$^{2+}$ state. An
+improvement in both magnetic and electrical properties is observed for 10 %
+Ba-doped BiFeO$_3$ nanoparticles compared to its undoped counterpart. The
+saturation magnetization of Bi$_{0.9}$Ba$_{0.1}$FeO$_3$ nanoparticles increase
+with reducing particle size in contrast with a decreasing trend of
+ferroelectric polarization. Moreover, a first order metamagnetic transition is
+noticed for $\sim$ 49 nm Bi$_{0.9}$Ba$_{0.1}$FeO$_3$ nanoparticles which
+disappeared with decreasing particle size. The observed strong size dependent
+multiferroic properties are attributed to the complex interaction between
+vacancy induced crystallographic defects, multiple valence states of Fe,
+uncompensated surface spins, crystallographic distortion and suppression of
+spiral spin cycloid of BiFeO$_3$.",1607.00169v1
+2016-10-13,Dynamic Domains of DTS: Simulations of a Spherical Magnetized Couette Flow,"The Derviche Tourneur Sodium experiment, a spherical Couette
+magnetohydrodynamics experiment with liquid sodium as the medium and a dipole
+magnetic field imposed from the inner sphere, recently underwent upgrades to
+its diagnostics to better characterize the flow and induced magnetic fields
+with global rotation. In tandem with the upgrades, a set of direct numerical
+simulations were run with the xshells code to give a more complete view of the
+fluid and magnetic dynamics at various rotation rates of the inner and outer
+spheres. These simulations reveal several dynamic regimes, determined by the
+Rossby number. At positive differential rotation there is a regime of
+quasigeostrophic flow, with low levels of fluctuations near the outer sphere.
+Negative differential rotation shows a regime of what appear to be saturated
+hydrodynamic instabilities at low negative differential rotation, followed by a
+regime where filamentary structures develop at low latitudes and persist over
+five to ten differential rotation periods as they drift poleward. We emphasize
+that all these coherent structures emerge from turbulent flows. At least some
+of them seem to be related to linear instabilities of the mean flow. The
+simulated flows can produce the same measurements as those that the physical
+experiment can take, with signatures akin to those found in the experiment.
+This paper discusses the relation between the internal velocity structures of
+the flow and their magnetic signatures at the surface.",1610.03964v4
+2017-03-27,Estimation of gradients in quantum metrology,"We develop a general theory to estimate magnetic field gradients in quantum
+metrology. We consider a system of $N$ particles distributed on a line whose
+internal degrees of freedom interact with a magnetic field. Usually gradient
+estimation is based on precise measurements of the magnetic field at two
+different locations, performed with two independent groups of particles. This
+approach, however, is sensitive to fluctuations of the off-set field
+determining the level-splitting of the particles and results in collective
+dephasing. In this work we use the framework of quantum metrology to assess the
+maximal accuracy for gradient estimation. For arbitrary positioning of
+particles, we identify optimal entangled and separable states allowing the
+estimation of gradients with the maximal accuracy, quantified by the quantum
+Fisher information. We also analyze the performance of states from the
+decoherence-free subspace (DFS), which are insensitive to the fluctuations of
+the magnetic offset field. We find that these states allow to measure a
+gradient directly, without the necessity of estimating the magnetic offset
+field. Moreover, we show that DFS states attain a precision for gradient
+estimation comparable to the optimal entangled states. Finally, for the above
+classes of states we find simple and feasible measurements saturating the
+quantum Cram\'er-Rao bound.",1703.09123v2
+2017-07-21,"Direct Evidence for the Source of Reported Magnetic Behavior in ""CoTe""","In order to unambiguously identify the source of magnetism reported in recent
+studies of the Co-Te system, two sets of high-quality, epitaxial CoTe$_x$ films
+(thickness $\simeq$ 300 nm) were prepared by pulse laser deposition (PLD).
+X-ray diffraction (XRD) shows that all of the films are epitaxial along the
+[001] direction and have the hexagonal NiAs structure. There is no indication
+of any second phase metallic Co peaks (either $fcc$ or $hcp$) in the XRD
+patterns. The two sets of CoTe$_x$ films were grown on various substrates with
+PLD targets having Co:Te in the atomic ratio of 50:50 and 35:65. From the
+measured lattice parameters $c = 5.396 \AA$ for the former and $c = 5.402\AA$
+for the latter, the compositions CoTe$_{1.71}$ (63.1% Te) and CoTe$_{1.76}$
+(63.8% Te), respectively, are assigned to the principal phase. Although XRD
+shows no trace of metallic Co second phase, the magnetic measurements do show a
+ferromagnetic contribution for both sets of films with the saturation
+magnetization values for the CoTe$_{1.71}$ films being approximately four times
+the values for the CoTe$_{1.76}$ films. $^{59}$Co spin-echo nuclear magnetic
+resonance (NMR) clearly shows the existence of metallic Co inclusions in the
+films. The source of weak ferromagnetism reported in several recent studies is
+due to the presence of metallic Co, since the stoichiometric composition ""CoTe""
+does not exist.",1707.06963v2
+2017-12-21,Exchange-torque-induced excitation of perpendicular standing spin waves in nanometer-thick YIG films,"Spin waves in ferrimagnetic yttrium iron garnet (YIG) films with ultralow
+magnetic damping are relevant for magnon-based spintronics and low-power
+wave-like computing. The excitation frequency of spin waves in YIG is rather
+low in weak external magnetic fields because of its small saturation
+magnetization, which limits the potential of YIG films for high-frequency
+applications. Here, we demonstrate how exchange-coupling to a CoFeB film
+enables efficient excitation of high-frequency perpendicular standing spin
+waves (PSSWs) in nanometer-thick (80 nm and 295 nm) YIG films using uniform
+microwave magnetic fields. In the 295-nm-thick YIG film, we measure intense
+PSSW modes up to 10th order. Strong hybridization between the PSSW modes and
+the ferromagnetic resonance mode of CoFeB leads to characteristic anti-crossing
+behavior in broadband spin-wave spectra. A dynamic exchange torque at the
+YIG/CoFeB interface explains the excitation of PSSWs. The localized torque
+originates from exchange coupling between two dissimilar magnetization
+precessions in the YIG and CoFeB layers. As a consequence, spin waves are
+emitted from the YIG/CoFeB interface and PSSWs form when their wave vector
+matches the perpendicular confinement condition. PSSWs are not excited when the
+exchange coupling between YIG and CoFeB is suppressed by a Ta spacer layer.
+Micromagnetic simulations confirm the exchange-torque mechanism.",1712.08204v1
+2018-01-16,Optical control of carrier wavefunction in magnetic quantum dots,"Spatially indirect Type-II band alignment in magnetically-doped quantum dot
+(QD) structures provides unexplored opportunities to control the magnetic
+interaction between carrier wavefunction in the QD and magnetic impurities.
+Unlike the extensively studied, spatially direct, QDs with Type-I band
+alignment where both electrons and holes are confined in the QD, in ZnTe QDs
+embedded in a (Zn,Mn)Se matrix only the holes are confined in the QDs.
+Photoexcitation with photon energy 3.06 eV (2.54 eV) generates electron-hole
+pairs predominantly in the (Zn,Mn)Se matrix (ZnTe QDs). The photoluminescence
+(PL) at 7 K in the presence of an external magnetic field exhibits an up to
+three-fold increase in the saturation red shift with the 2.54 eV excitation
+compared to the shift observed with 3.06 eV excitation. This unexpected result
+is attributed to multiple hole occupancy of the QD and the resulting increased
+penetration of the hole wavefunction tail further into the (Zn,Mn)Se matrix.
+The proposed model is supported by microscopic calculations which accurately
+include the role of hole-hole Coulomb interactions as well as the hole-Mn spin
+exchange interactions.",1801.05090v1
+2018-01-26,Fully kinetic large scale simulations of the collisionless Magnetorotational instability,"We present two-dimensional particle-in-cell (PIC) simulations of the fully
+kinetic collisionless magnetorotational instability (MRI) in weakly magnetized
+(high $\beta$) pair plasma. The central result of this numerical analysis is
+the emergence of a self-induced turbulent regime in the saturation state of the
+collisionless MRI, which can only be captured for large enough simulation
+domains. One of the underlying mechanisms for the development of this turbulent
+state is the drift-kink instability (DKI) of the current sheets resulting from
+the nonlinear evolution of the channel modes. The onset of the DKI can only be
+observed for simulation domain sizes exceeding several linear MRI wavelengths.
+The DKI, together with ensuing magnetic reconnection, activate the turbulent
+motion of the plasma in the late stage of the nonlinear evolution of the MRI.
+At steady state, the magnetic energy has an MHD-like spectrum with a slope of
+$k^{-5/3}$ for $k\rho<1$ and $k^{-3}$ for sub-Larmor scale ($k\rho>1$). We also
+examine the role of the collisionless MRI and associated magnetic reconnection
+in the development of pressure anisotropy. We study the stability of the system
+due to this pressure anisotropy, observing the development of mirror
+instability during the early-stage of the MRI. We further discuss the
+importance of magnetic reconnection for particle acceleration during the
+turbulence regime. In particular, consistent with reconnection studies, we show
+that at late times the kinetic energy presents a characteristic slope of
+$\epsilon^{-2}$ in the high-energy region.",1801.08657v2
+2018-02-22,Correlation of tunnel magnetoresistance with the magnetic properties in perpendicular CoFeB-based junctions with exchange bias,"We investigate the dependence of magnetic properties on the post-annealing
+temperature/time, the thickness of soft ferromagnetic electrode and Ta dusting
+layer in the pinned electrode as well as their correlation with the tunnel
+magnetoresistance ratio, in a series of perpendicular magnetic tunnel junctions
+of materials sequence
+Ta/Pd/IrMn/CoFe/Ta$(\textit{x})$/CoFeB/MgO$(\textit{y})$/CoFeB$(\textit{z})$/Ta/Pd.
+We obtain a large perpendicular exchange bias of 79.6$\,$kA/m for $x=0.3\,$nm.
+For stacks with $z=1.05\,$nm, the magnetic properties of the soft electrode
+resemble the characteristics of superparamagnetism. For stacks with
+$x=0.4\,$nm, $y=2\,$nm, and $z=1.20\,$nm, the exchange bias presents a
+significant decrease at post annealing temperature
+$T_\textrm{ann}=330\,^{\circ}$C for 60 min, while the interlayer exchange
+coupling and the saturation magnetization per unit area sharply decay at
+$T_\textrm{ann}=340\,^{\circ}$C for 60 min. Simultaneously, the tunnel
+magnetoresistance ratio shows a peak of $65.5\%$ after being annealed at
+$T_\textrm{ann}=300\,^{\circ}$C for 60 min, with a significant reduction down
+to $10\%$ for higher annealing temperatures
+($T_\textrm{ann}\geq330\,^{\circ}$C) and down to $14\%$ for longer annealing
+times ($T_\textrm{ann}=300\,^{\circ}$C for 90 min). We attribute the large
+decrease of tunnel magnetoresistance ratio to the loss of exchange bias in the
+pinned electrode.",1802.08002v2
+2018-05-07,Quantum Criticality of an Ising-like Spin-1/2 Antiferromagnetic Chain in Transverse Magnetic Field,"We report on magnetization, sound velocity, and magnetocaloric-effect
+measurements of the Ising-like spin-1/2 antiferromagnetic chain system
+BaCo$_2$V$_2$O$_8$ as a function of temperature down to 1.3 K and applied
+transverse magnetic field up to 60 T. While across the N\'{e}el temperature of
+$T_N\sim5$ K anomalies in magnetization and sound velocity confirm the
+antiferromagnetic ordering transition, at the lowest temperature the
+field-dependent measurements reveal a sharp softening of sound velocity $v(B)$
+and a clear minimum of temperature $T(B)$ at $B^{c,3D}_\perp=21.4$ T,
+indicating the suppression of the antiferromagnetic order. At higher fields,
+the $T(B)$ curve shows a broad minimum at $B^c_\perp = 40$ T, accompanied by a
+broad minimum in the sound velocity and a saturation-like magnetization. These
+features signal a quantum phase transition which is further characterized by
+the divergent behavior of the Gr\""{u}neisen parameter $\Gamma_B \propto
+(B-B^{c}_\perp)^{-1}$. By contrast, around the critical field, the
+Gr\""{u}neisen parameter converges as temperature decreases, pointing to a
+quantum critical point of the one-dimensional transverse-field Ising model.",1805.02392v1
+2018-08-07,Magnetoresistance in the in-plane magnetic field induced semi-metallic phase of inverted HgTe quantum wells,"In this study we have measured the magnetoresistance response of inverted
+HgTe quantum wells in the presence of a large parallel magnetic field up to 33
+T is applied. We show that in quantum wells with inverted band structure a
+monotonically decreasing magnetoresistance is observed when a magnetic field up
+to order 10 T is applied parallel to the quantum well plane. This feature is
+accompanied by a vanishing of non-locality and is consistent with a predicted
+modification of the energy spectrum that becomes gapless at a critical in-plane
+field $B_{c}$. Magnetic fields in excess of $B_c$ allow us to investigate the
+evolution of the magnetoresistance in this field-induced semi-metallic region
+beyond the known regime. After an initial saturation phase in the presumably
+gapless phase, we observe a strong upturn of the longitudinal resistance. A
+small residual Hall signal picked up in non-local measurements suggests that
+this feature is likely a bulk phenomenon and caused by the semi-metallicity of
+the sample. Theoretical calculations indeed support that the origin of these
+features is classical and a power law upturn of the resistance can be expected
+due to the specifics of two-carrier transport in thin (semi-)metallic samples
+subjected to large magnetic fields.",1808.02268v1
+2019-04-25,Correlations far from equilibrium in charged strongly coupled fluids subjected to a strong magnetic field,"Within a holographic model, we calculate the time evolution of 2-point and
+1-point correlation functions (of selected operators) within a charged strongly
+coupled system of many particles. That system is thermalizing from an
+anisotropic initial charged state far from equilibrium towards equilibrium
+while subjected to a constant external magnetic field. One main result is that
+thermalization times for 2-point functions are significantly (approximately
+three times) larger than those of 1-point functions. Magnetic field and charge
+amplify this difference, generally increasing thermalization times. However,
+there is also a competition of scales between charge density, magnetic field,
+and initial anisotropy, which leads to an array of qualitative changes on the
+2- and 1-point functions. There appears to be a strong effect of the medium on
+2-point functions at early times, but approximately none at later times. At
+strong magnetic fields, an apparently universal thermalization time emerges, at
+which all 2-point functions appear to thermalize regardless of any other scale
+in the system. Hence, this time scale is referred to as saturation time scale.
+As extremality is approached in the purely charged case, 2- and 1-point
+functions appear to equilibrate at infinitely late time. We also compute
+2-point functions of charged operators. Our results can be taken to model
+thermalization in heavy ion collisions, or thermalization in selected condensed
+matter systems.",1904.11507v2
+2019-05-10,Magnetic tunnel junctions with a B2-ordered CoFeCrAl equiatomic Heusler alloy,"The equiatomic quaternary Heusler alloy CoFeCrAl is a candidate material for
+spin-gapless semiconductors (SGSs). However, to date, there have been no
+experimental attempts at fabricating a junction device. This paper reports a
+fully epitaxial (001)-oriented MgO barrier magnetic tunnel junction (MTJ) with
+CoFeCrAl electrodes grown on a Cr buffer. X-ray and electron diffraction
+measurements show that the (001) CoFeCrAl electrode films with atomically flat
+surfaces have a $B2$-ordered phase. The saturation magnetization is 380
+emu/cm$^3$, almost the same as the value given by the Slater--Pauling--like
+rule, and the maximum tunnel magnetoresistance ratios at 300 K and 10 K are 87%
+and 165%, respectively. Cross-sectional electron diffraction analysis shows
+that the MTJs have MgO interfaces with fewer dislocations. The temperature- and
+bias-voltage-dependence of the transport measurements indicates magnon-induced
+inelastic electron tunneling overlapping with the coherent electron tunneling.
+X-ray magnetic circular dichroism (XMCD) measurements show a ferromagnetic
+arrangement of the Co and Fe magnetic moments of $B2$-ordered CoFeCrAl, in
+contrast to the ferrimagnetic arrangement predicted for the $Y$-ordered state
+possessing SGS characteristics. Ab-initio calculations taking account of the
+Cr-Fe swap disorder qualitatively explain the XMCD results. Finally, the effect
+of the Cr-Fe swap disorder on the ability for electronic states to allow
+coherent electron tunneling is discussed.",1905.04070v1
+2019-06-27,Complex magnetic phase diagram of metamagnetic MnPtSi,"The magnetic, thermal and transport properties as well as electronic band
+structure of MnPtSi are reported. MnPtSi is a metal that undergoes a
+ferromagnetic transition at $T_{\mathrm{C}}=340$(1) K and a spin-reorientation
+transition at $T_{\mathrm{N}}=326$(1) K to an antiferromagnetic phase.
+First-principles electronic structure calculations indicate a not-fully
+polarized spin state of Mn in a $d^5$ electron configuration with $J=S=3$/2, in
+agreement with the saturation magnetization of 3~$\mu_{\mathrm{B}}$ in the
+ordered state and the observed paramagnetic effective moment. A sizeable
+anomalous Hall effect in the antiferromagnetic phase alongside the
+computational study suggests that the antiferromagnetic structure is
+non-collinear. Based on thermodynamic and resistivity data we construct a
+magnetic phase diagram. Magnetization curves $M$($H$) at low temperatures
+reveal a metamagnetic transition of spin-flop type. The spin-flopped phase
+terminates at a critical point with $T_{\mathrm{cr}}\approx 300$ K and
+$H_{\mathrm{cr}}\approx 10$ kOe, near which a peak of the magnetocaloric
+entropy change is observed. Using Arrott plot analysis and magnetoresistivity
+data we argue that the metamagnetic transition is of a first-order type,
+whereas the strong field dependence of $T_{\mathrm{N}}$ and the linear
+relationship of the $T_{\mathrm{N}}$ with $M^2$ hint at its magnetoelastic
+nature.",1906.11864v1
+2019-09-17,Strong quantum fluctuations due to competition between magnetic phases in a pyrochlore iridate,"We report neutron diffraction measurements of the magnetic structures in two
+pyrochlore iridates, Yb2Ir2O7 and Lu2Ir2O7. Both samples exhibit the
+all-in-all-out magnetic structure on the Ir4+ sites below TN~ 150,K, with a low
+temperature moment of around 0.45 muB/Ir. Below 2\,K, the Yb moments in
+Yb2Ir2O7 begin to order ferromagnetically. However, even at 40 mK the ordered
+moment is only 0.57(3)muB/Yb, well below the saturated moment of the ground
+state doublet of Yb3+ (1.9 muB/Yb), deduced from magnetization measurements and
+from a refined model of the crystal field environment, and also significantly
+smaller than the ordered moment of Yb in Yb2Ti2O7 (0.9 muB/Yb). A mean-field
+analysis shows that the reduced moment on Yb is a consequence of enhanced phase
+competition caused by coupling to the all-in-all-out magnetic order on the Ir
+sublattice.",1909.07819v3
+2019-10-25,Interplay of Bound Magnetic Polaron and p-d exchange interaction in Co-doped 3C-SiC,"Bound Magnetic Polarons (BMP) have been proposed to play an important role in
+doped wide band gap semiconductors. We report the experimental evidence
+supporting polaronic magnetism and the role of defects on it. Temperature
+variation of electron paramagnetic resonance study reveals that the valence
+state of cobalt is 2+ and its nearest environment in the system is distorted
+tetrahedral in nature. Room temperature ferromagnetism have been found in all
+the doped [Co (1, 3, 5) % doped 3C-SiC] samples. The Curie temperature, TC of
+the samples have been found to be above 800 K. The isothermal magnetization
+plots, to determine the strength of domain wall pinning were analyzed using the
+Jiles-Atherton Model. The temperature variation of the anisotropic constant was
+determined using Law of Approach to saturation (LAS), which decreases with
+increase in temperature. Quantitative analysis of magnetic interaction has been
+carried out and the result is explained by using BMP Model, which probably
+arises out of the exchange interaction of Co2+ ions with related (Si, C)
+defects.",1910.11899v3
+2019-10-29,Adiabatic Quantum Estimation: A Numerical Study of the Heisenberg XX Model with Antisymmetric Exchange,"In this paper, we address the adiabatic technique for quantum estimation of
+the azimuthal orientation of a magnetic field. Exactly solving a model
+consisting of a two-qubit system, where one of which is driven by a static
+magnetic field while the other is coupled with the magnetic field rotating
+adiabatically, we obtain the analytical expression of the quantum Fisher
+information (QFI). We investigate how the two-qubit system can be used to probe
+the azimuthal direction of the field and analyze the roles of the intensities
+of the magnetic fields, Dzyaloshinskii-Moriya interaction, spin-spin coupling
+coefficient, and the polar orientation of the rotating field on the precision
+of the estimation. In particular, it is illustrated that the QFI trapping or
+saturation may occur if the qubit is subjected to a strong rotating field.
+Moreover, we discuss how the azimuthal direction of the rotating field can be
+estimated using only the qubit not affected by that field and investigate the
+conditions under which this strategy is more efficient than use of the qubit
+locally interacting with the adiabatically rotating field. Interestingly, in
+the one-qubit scenario, it was found that when the rotating field is weak, the
+best estimation is achieved by subjecting the probe to a static magnetic field.",1910.13478v4
+2019-11-25,Magnetising the circumgalactic medium of disk galaxies,"The circumgalactic medium (CGM) is one of the frontiers of galaxy formation
+and intimately connected to the galaxy via accretion of gas on to the galaxy
+and gaseous outflows from the galaxy. Here we analyse the magnetic field in the
+CGM of the Milky Way-like galaxies simulated as part of the \textsc{Auriga}
+project that constitutes a set of high resolution cosmological
+magnetohydrodynamical zoom simulations. We show that before $z=1$ the CGM
+becomes magnetised via galactic outflows that transport magnetised gas from the
+disk into the halo. At this time the magnetisation of the CGM closely follows
+its metal enrichment. We then show that at low redshift an in-situ turbulent
+dynamo that operates on a timescale of Gigayears further amplifies the magnetic
+field in the CGM and saturates before $z=0$. The magnetic field strength
+reaches a typical value of $0.1\,\mu G$ at the virial radius at $z=0$ and
+becomes mostly uniform within the virial radius. Its Faraday rotation signal is
+in excellent agreement with recent observations. For most of its evolution the
+magnetic field in the CGM is an unordered small scale field. Only strong
+coherent outflows at low redshift are able to order the magnetic field in parts
+of the CGM that are directly displaced by these outflows.",1911.11163v3
+2019-12-17,Antiferromagnetic CuMnAs: Ab initio description of finite temperature magnetism and resistivity,"Noncollinear magnetic moments in antiferromagnets (AFM) lead to a complex
+behavior of electrical transport, even to a decreasing resistivity due to an
+increasing temperature. Proper treatment of such phenomena is required for
+understanding AFM systems at finite temperatures; however first-principles
+description of these effects is complicated. With ab initio techniques, we
+investigate three models of spin fluctuations (magnons) influencing the
+transport in AFM CuMnAs; the models are numerically feasible and easily
+implementable to other studies. We numerically justified a fully relativistic
+collinear disordered local moment approach and we present its uncompensated
+generalization. A saturation or a decrease of resistivity caused by magnons,
+phonons, and their combination (above approx. 400 K) was observed and explained
+by changes in electronic structure. Within the coherent potential
+approximation, our finite-temperature approaches may be applied also to systems
+with impurities, which are found to have a large impact not only on residual
+resistivity, but also on canting of magnetic moments from the AFM to the
+ferromagnetic (FM) state.",1912.08025v4
+2020-01-23,Global simulations of self-gravitating magnetized protoplanetary disks,"In the early stages of a protoplanetary disk, when its mass is a significant
+fraction of its star's, turbulence generated by gravitational instability (GI)
+should feature significantly in the disk's evolution. At the same time, the
+disk may be sufficiently ionised for magnetic fields to play some role in the
+dynamics. Though usually neglected, the impact of magnetism on the GI may be
+critical, with consequences for several processes: the efficiency of accretion,
+spiral structure formation, fragmentation, and the dynamics of solids. In this
+paper, we report on global three-dimensional magnetohydrodynamical simulations
+of a self-gravitating protoplanetary disk using the meshless finite mass (MFM)
+Lagrangian technique. We confirm that GI spiral waves trigger a dynamo that
+amplifies an initial magnetic field to nearly thermal amplitudes (plasma beta <
+10), an order of magnitude greater than that generated by the
+magneto-rotational instability alone. We also determine the dynamo's nonlinear
+back reaction on the gravitoturbulent flow: the saturated state is
+substantially hotter, with an associated larger Toomre parameter and weaker,
+more 'flocculent' spirals. But perhaps of greater import is the dynamo's
+boosting of accretion via a significant Maxwell stress; mass accretion is
+enhanced by factors of several relative to either pure GI or pure MRI. Our
+simulations use ideal MHD, an admittedly poor approximation in protoplanetary
+disks, and thus future studies should explore the full gamut of non-ideal MHD.
+In preparation for that, we exhibit a small number of Ohmic runs that reveal
+that the dynamo, if anything, is stronger in a non-ideal environment. This work
+confirms that magnetic fields are a potentially critical ingredient in
+gravitoturbulent young disks, possibly controlling their evolution, especially
+via their enhancement of (potentially episodic) accretion.",2001.08693v1
+2020-01-31,Measuring stellar magnetic helicity density,"Helicity is a fundamental property of a magnetic field but to date it has
+only been possible to observe its evolution in one star - the Sun. In this
+paper we provide a simple technique for mapping the large-scale helicity
+density across the surface of any star using only observable quantities: the
+poloidal and toroidal magnetic field components (which can be determined from
+Zeeman-Doppler imaging) and the stellar radius. We use a sample of 51 stars
+across a mass range of 0.1-1.34 M$_\odot$ to show how the helicity density
+relates to stellar mass, Rossby number, magnetic energy and age. We find that
+the large-scale helicity density increases with decreasing Rossby number $R_o$,
+peaking at $R_o \simeq 0.1$, with a saturation or decrease below that. For both
+fully- and partially-convective stars we find that the mean absolute helicity
+density scales with the mean squared toroidal magnetic flux density according
+to the power law: $|\langle{h\,}\rangle|$ $\propto$
+$\langle{\rm{B_{tor}}^2_{}\,\rangle}^{0.86\,\pm\,0.04}$. The scatter in this
+relation is consistent with the variation across a solar cycle, which we
+compute using simulations and observations across solar cycles 23 and 24
+respectively. We find a significant decrease in helicity density with age.",2001.11749v1
+2020-05-23,"Structural, Electronic, and Magnetic Properties of HiPIMS Grown Co-N Thin Films","We studied the growth behavior, structural, electronic, and magnetic
+properties of cobalt nitride (Co-N) thin films deposited using direct current
+(dc) and high power impulse magnetron sputtering (HiPIMS) processes. The N$_2$
+partial gas flow (\pn) was varied in close intervals to achieve the optimum
+conditions for the growth of tetra cobalt nitride (\tcn) phase. We found that
+Co-N films grown using HiPIMS process adopt (111) orientation as compared to
+the growth taking place along the (100) direction in the dcMS process. It was
+observed that HiPIMS grown Co-N~films were superior in terms of crystallite
+size and uniform surface morphology. The local structure of films was
+investigated using x-ray absorption fine structure (XAFS) measurements. We
+found that the high energy of adatoms in the HiPIMS technique assisted in the
+greater stabilization of fcc-Co and novel \tcn~phase relative to the dcMS
+process. Magnetic properties of Co-N thin films were studied using
+magneto-optical Kerr effect, vibrating sample magnetometry and polarized
+neutron reflectivity. It was found that though the saturation magnetization
+remains almost similar in films grown by dcMS or HiPIMS processes, they differ
+in terms of their magnetic anisotropy. Such variation can be understood in
+terms of differences in the growth mechanisms in dcMS and HiPIMS processes
+affecting the local structure of resulting \tcn~phase.",2005.11584v1
+2020-05-28,Spin-Pumping-Induced Non-Linear Electric Current on the Surface of a Ferromagnetic Topological Insulator,"We investigate the spin-pumping-induced electric current on the surface of a
+three-dimensional topological insulator hybridized with a ferromagnet, namely,
+ferromagnetic topological insulator. In order to do this, we establish the
+microscopic formalism and construct the perturbation theory using a Keldysh
+Green's function approach. We analyze how this electric current is generated by
+an exchange interaction and an external ac magnetic field, which is the driving
+force of ferromagnetic resonance as well as the spin pumping. The mechanism is
+as follows. First, the ferromagnetic resonance is driven and a zero-momentum
+magnon emerges. It is the fluctuation from the saturation magnetization
+pointing parallel to the precession axis of the ferromagnetic resonance. After
+then, the spin pumping is generated with the zero-momentum magnon being the
+carrier of spin. The zero-momentum magnon and the topological insulator surface
+state couples through the exchange interaction and the spin carried by the
+magnon is transferred to it. Owing to the spin-momentum locking, the
+transferred spin is converted into the momentum of topological insulator
+surface state leading to the generation of electric current flowing
+perpendicular to the precession axis of the ferromagnetic resonance. It is
+quadratic in the amplitude of external ac magnetic field whereas it is linear
+to the strength of the exchange interaction. The associated electric voltage is
+described by the spectrum of zero-momentum magnon. The non-linearity of
+spin-pumping-induced electric current in the ac magnetic field as well as the
+linearity in the exchange-interaction strength reflects that the surface of
+ferromagnetic topological insulator has a high-performing functionality of
+generating the electric charge current by magnetic controlling.",2005.13850v1
+2020-05-28,Spectral signatures of the surface anomalous Hall effect in magnetic axion insulators,"The topological surface states of magnetic topological systems, such as Weyl
+semimetals and axion insulators, are associated with unconventional transport
+properties such as nonzero or half-quantized surface anomalous Hall effect.
+Here we study the surface anomalous Hall effect and its spectral signatures in
+different magnetic topological phases using both model Hamiltonian and
+first-principles calculations. We demonstrate that by tailoring the
+magnetization and interlayer electron hopping, a rich three-dimensional
+topological phase diagram can be established, including three types of
+topologically distinct insulating phases bridged by Weyl semimetals, and can be
+directly mapped to realistic materials such as MnBi2Te4/(Bi2Te3)n systems.
+Among them, we find that the surface anomalous Hall conductivity in the
+axion-insulator phase is a well-localized quantity either saturated at or
+oscillating around e2/2h, depending on the magnetic homogeneity. We also
+discuss the resultant chiral hinge modes embedded inside the side surface bands
+as the potential experimental signatures for transport measurements. Our study
+is a significant step forward towards the direct realization of long-sought
+axion insulators in realistic material systems.",2005.13943v4
+2020-06-26,Super-Necking Crystal Growth and Structural and Magnetic Properties of SrTb$_2$O$_4$ Single Crystals,"We report on single-crystal growths of the SrTb$_2$O$_4$ compound by a
+super-necking technique with a laser-floating-zone furnace and study the
+stoichiometry, growth mode, and structural and magnetic properties by scanning
+electronic microscopy, neutron Laue, X-ray powder diffraction, and the physical
+property measurement system. We optimized the growth parameters, mainly the
+growth speed, atmosphere, and the addition of a Tb$_4$O$_7$ raw material.
+Neutron Laue diffraction displays the characteristic feature of a single
+crystal. Our study reveals an atomic ratio of Sr:Tb $ = 0.97(2){:}2.00(1)$ and
+a possible layer by layer crystal growth mode. Our X-ray powder diffraction
+study determines the crystal structure, lattice constants and atomic positions.
+The paramagnetic (PM) Curie--Weiss (CW) temperature $\theta_{\texttt{CW}} =$
+5.00(4) K, and the effective PM moment $M^{\texttt{eff}}_{\texttt{mea}} =$
+10.97(1) $\mu_\texttt{B}$ per Tb$^{3+}$ ion. The data of magnetization versus
+temperature can be divided into three regimes, showing a coexistence of
+antiferromagnetic and ferromagnetic interactions. This probably leads to the
+magnetic frustration in the SrTb$_2$O$_4$ compound. The magnetization at 2 K
+and 14 T originates from both the Tb1 and Tb2 sites and is strongly frustrated
+with an expected saturation field at $\sim$41.5 T, displaying an intricate
+phase diagram with three ranges.",2006.14754v2
+2020-10-13,Dipolar-stabilized first and second-order antiskyrmions in ferrimagnetic multilayers,"Skyrmions and antiskyrmions are topologically protected spin structures with
+opposite topological charge. Particularly in coexisting phases, these two types
+of magnetic quasi-particles may show fascinating physics and potential for
+spintronic devices. While skyrmions are observed in a wide range of materials,
+until now antiskyrmions were exclusive to materials with D2d symmetry. In this
+work, we show first and second-order antiskyrmions stabilized by magnetic
+dipole-dipole interaction in Fe/Gd-based multilayers. We modify the magnetic
+properties of the multilayers by Ir insertion layers. Using Lorentz
+transmission electron microscopy imaging, we observe coexisting antiskyrmions,
+Bloch skyrmions, and type-2 bubbles and determine the range of material
+properties and magnetic fields where the different spin objects form and
+dissipate. We perform micromagnetic simulations to obtain more insight into the
+studied system and conclude that the reduction of saturation magnetization and
+uniaxial anisotropy leads to the existence of this zoo of different spin
+objects and that they are primarily stabilized by dipolar interaction.",2010.06555v3
+2020-12-04,Anomalous Hall and Nernst effects in ferrimagnetic Mn$_4$N films: possible interpretation and prospect for enhancement,"Ferrimagnetic Mn$_4$N is a promising material for heat flux sensors based on
+the anomalous Nernst effect (ANE) because of its sizable uniaxial magnetic
+anisotropy ($K_{\rm u}$) and low saturation magnetization ($M_{\rm s}$). We
+experimentally and theoretically investigated the ANE and anomalous Hall effect
+in sputter-deposited Mn$_4$N films. It was revealed that the observed negative
+anomalous Hall conductivity ($\sigma_{xy}$) could be explained by two different
+coexisting magnetic structures, that is, a dominant magnetic structure with
+high $K_{\rm u}$ contaminated by another structure with negligible $K_{\rm u}$
+owing to an imperfect degree of order of nitrogen. The observed transverse
+thermoelectric power ($S_{\rm ANE}$) of $+0.5\, \mu{\rm V/K}$ at $300\, {\rm
+K}$ gave a transverse thermoelectric coefficient ($\alpha_{xy}$) of $+0.34\,
+{\rm A/(m \cdot K)}$, which was smaller than the value predicted from
+first-principles calculation. The interpretation for $\alpha_{xy}$ based on the
+first-principles calculations led us to conclude that the realization of single
+magnetic structure with high $K_{\rm u}$ and optimal adjustment of the Fermi
+level are promising approaches to enhance $S_{\rm ANE}$ in Mn$_4$N through the
+sign reversal of $\sigma_{xy}$ and the enlargement of $\alpha_{xy}$ up to a
+theoretical value of $1.77\, {\rm A/(m \cdot K)}$.",2012.02510v2
+2021-04-18,Impact of particle size on the magnetic properties of highly crystalline Yb3+ substituted Ni-Zn nanoferrites,"Yb-substituted Ni-Zn ferrites have been synthesized using sol-gel auto
+combustion method. The structural characterization of the compositions has been
+performed by X-ray diffraction analysis, field emission scanning electron
+microscopy (FESEM), quantum design physical properties measurement system
+(PPMS). That ensured the formation of single phase cubic spinel structure.
+Crystallite and average grain size are calculated and found to decrease with
+increasing Yb3+ contents. Saturation magnetization and Bohr magnetic moment
+decrease while the coercivity increases with the increase in Yb3+ contents
+successfully explained by the Neels collinear two sub-lattice model and
+critical size effect, respectively. Critical particle size has been estimated
+at 6.4 nm, the transition point between single domain regime (below the
+critical size) and multi-domain regime (beyond the critical size). Curie
+temperature reduces due to the weakening of A-O-B super exchange interaction
+and redistribution of cations, confirmed by the M-T graph. The compositions
+retain ferromagnetic ordered structured below Curie temperature and above Curie
+temperature, it becomes paramagnetic, making them plausible candidates for high
+temperature magnetic device applications. The relative quality factor peak is
+obtained at a very high frequency, indicating the compositions could also be
+applicable for high frequency magnetic device applications.",2104.08694v1
+2021-06-01,Multiple field-induced phases in the frustrated triangular magnet Cs$_3$Fe$_2$Br$_9$,"The recently discovered material Cs$_3$Fe$_2$Br$_9$ contains Fe$_2$Br$_9$
+bi-octahedra forming triangular layers with hexagonal stacking along the $c$
+axis. In contrast to isostructural Cr-based compounds, the zero-field ground
+state is not a nonmagnetic $S=0$ singlet-dimer state. Instead, the Fe$_2$Br$_9$
+bi-octahedra host semiclassical $S=5/2$ Fe$^{3+}$ spins with a pronounced
+easy-axis anisotropy along $c$ and interestingly, the intra-dimer spins are
+ordered ferromagnetically. The high degree of magnetic frustration due to
+(various) competing intra- and inter-dimer couplings leads to a surprisingly
+rich magnetic phase diagram. Already the zero-field ground state is reached via
+an intermediate phase, and the high-field magnetization and thermal expansion
+data for $H\parallel c$ identify ten different ordered phases. Among them are
+phases with constant magnetization of 1/3, respectively 1/2 of the saturation
+value, and several transitions are strongly hysteretic with pronounced length
+changes reflecting strong magnetoelastic coupling.",2106.00440v3
+2021-09-08,Picosecond creation of switchable optomagnets with giant photoinduced Kerr rotations in polar antiferromagnetic (Fe$_{1-x}$Zn$_{x}$)$_{2}$Mo$_{3}$O$_{8}$,"On-demand spin orientation with long polarized lifetime and easily detectable
+signal is an ultimate goal for spintronics. However, there still exists a
+trade-off between controllability and stability of spin polarization, awaiting
+a significant breakthrough. Here, we demonstrate switchable optomagnet effects
+in (Fe$_{1-x}$Zn$_{x}$)$_{2}$Mo$_{3}$O$_{8}$, from which we can obtain tunable
+magnetization, spanning from -40$\%$ to 40$\%$ of a saturated magnetization
+that is created from zero magnetization in the antiferromagnetic state without
+magnetic fields. It is accomplishable via utilizing circularly-polarized laser
+pulses to excite spin-flip transitions in polar antiferromagnets that have no
+spin canting, traditionally hard to control without very strong magnetic
+fields. The spin controllability in (Fe$_{1-x}$Zn$_{x}$)$_{2}$Mo$_{3}$O$_{8}$
+originates from its polar structure that breaks the crystal inversion symmetry,
+allowing distinct on-site $d$-$d$ transitions for selective spin flip. By
+chemical doping, we exploit the phase competition between antiferromagnetic and
+ferrimagnetic states to enhance and stabilize the optomagnet effects, which
+result in long-lived photoinduced Kerr rotations. The present study, creating
+switchable giant optomagnet effects in polar antiferromagnets, sketches a new
+blueprint for the function of antiferromagnetic spintronics.",2109.03498v1
+2021-12-21,High-speed imaging of magnetized plasmas: when electron temperature matters,"High speed camera imaging is a powerful tool to probe the spatiotemporal
+features of unsteady processes in plasmas, usually assuming light fluctuations
+to be a proxy for the plasma density fluctuations. In this article, we
+systematically compare high speed camera imaging with simultaneous measurements
+of the plasma parameters -- plasma density, electron temperature, floating
+potential -- in a modestly magnetized Argon plasma column at low pressure (1
+mTorr, magnetic fields ranging from 160 to 640~G). The light emission was
+filtered around $488\pm5$~nm, $750\pm5$~nm, $810\pm5$~nm. We show that the
+light intensity cannot be interpreted as a proxy for the plasma density and
+that the electron temperature cannot be ignored when interpreting high speed
+imaging, both for the time-averaged profiles and for the fluctuations. The
+features of plasma parameter fluctuations are investigated, with a focus on ion
+acoustic waves (at frequency around 70 kHz) at low magnetic field and
+low-frequency azimuthal waves (around a few kHz) at larger magnetic fields. An
+excellent match is found between the high speed images fluctuations and an
+Arrhenius law functional form which incorporates fluctuations of the plasma
+density and of the electron temperature. These results explain the
+discrepancies between ion saturation current and narrow-band imaging
+measurements previously reported in the literature.",2112.11372v1
+2022-01-10,Magnetic field amplification by a plasma cavitation instability in relativistic shock precursors,"Plasma streaming instabilities play an important role in magnetic field
+amplification and particle acceleration in relativistic shocks and their
+environments. However, in the far shock precursor region where accelerated
+particles constitute a highly relativistic and dilute beam, streaming
+instabilities typically become inefficient and operate at very small scales
+when compared to the gyroradii of the beam particles. We report on a plasma
+cavitation instability that is driven by dilute relativistic beams and can
+increase both the magnetic field strength and coherence scale by orders of
+magnitude to reach near-equipartition values with the beam energy density. This
+instability grows after the development of the Weibel instability and is
+associated with the asymmetric response of background leptons and ions to the
+beam current. The resulting net inductive electric field drives a strong energy
+asymmetry between positively and negatively charged beam species. Large-scale
+particle-in-cell simulations are used to verify analytical predictions for the
+growth and saturation level of the instability and indicate that it is robust
+over a wide range of conditions, including those associated with pair-loaded
+plasmas. These results can have important implications for the magnetization
+and structure of shocks in gamma-ray bursts, and more generally for magnetic
+field amplification and asymmetric scattering of relativistic charged particles
+in plasma astrophysical environments.",2201.03547v1
+2022-02-03,Asymptotic behaviour of rotating convection-driven dynamos in the plane layer geometry,"Dynamos driven by rotating convection in the plane layer geometry are
+investigated numerically for a range of Ekman number ($E$), magnetic Prandtl
+number ($Pm$) and Rayleigh number ($Ra$). The primary purpose of the
+investigation is to compare results of the simulations with previously
+developed asymptotic theory that is applicable in the limit of rapid rotation.
+We find that all of the simulations are in the quasi-geostrophic regime in
+which the Coriolis and pressure gradient forces are approximately balanced at
+leading order, whereas all other forces, including the Lorentz force, act as
+perturbations. Agreement between simulation output and asymptotic scalings for
+the energetics, flow speeds, magnetic field amplitude and length scales is
+found. The transition from large scale dynamos to small scale dynamos is well
+described by the magnetic Reynolds number based on the small convective length
+scale, $\widetilde{Rm}$, with large scale dynamos preferred when
+$\widetilde{Rm} \lesssim O(1)$. The magnitude of the large scale magnetic field
+is observed to saturate and become approximately constant with increasing
+Rayleigh number. Energy spectra show that all length scales present in the flow
+field and the small-scale magnetic field are consistent with a scaling of
+$E^{1/3}$, even in the turbulent regime. For a fixed value of $E$, we find that
+the viscous dissipation length scale is approximately constant over a broad
+range of $Ra$; the ohmic dissipation length scale is approximately constant
+within the large scale dynamo regime, but transitions to a
+$\widetilde{Rm}^{-1/2}$ scaling in the small scale dynamo regime.",2202.01382v2
+2022-02-05,Cuprates phase diagram deduced from magnetic susceptibility: what is the `true' pseudogap line?,"Two contradictory phase diagrams have dominated the literature of high-$T_c$
+cuprate superconductors. Does the pseudogap line cross the superconducting
+$T_c$-dome or not? To answer, we have revisited the experimental magnetic
+susceptibility and knight shift of four different compounds,
+La$_{1-x}$Sr$_x$CuO$_4$, Bi$_2$Sr$_2$Ca$_{1-x}$Y$_x$Cu$_2$O$_8$,
+Bi$_2$Sr$_2$CaCu$_2$O$_{8+y}$, and YBa$_2$Cu$_3$O$_{6+y}$, as a function of
+temperature and doping. The susceptibility can be described by the same
+function for all materials, having a magnetic and an electronic contributions.
+The former is the 2D antiferromagnetic (AF) square lattice response, with a
+characteristic temperature of magnetic correlations $T_{max}$. The latter is
+the `Pauli' term, revealing the gap opening in the electronic density of states
+at the pseudogap temperature $T^*$.
+  From precise fits of the data, we find that $T_{max}(p)$ decreases linearly
+as a function of doping ($p$) over a wide range, but saturates abruptly in the
+overdoped regime. Concomitantly, $T^*(p)$ is {\it linear and tangent} to the
+dome, either crossing or approaching $T_{max}(p)$ at the top of the dome,
+indicating a qualitative change of behavior from underdoped to overdoped
+regimes.
+  Contrary to the idea that the pseudogap terminates just above optimal doping,
+our analysis suggests that the gap exists throughout the phase diagram. It is
+consistent with a pseudogap due to hole pairs, or `pairons', above $T_c$. We
+conclude that $T_{max}$, reflecting the AF magnetic correlations, has often
+been misinterpreted as the pseudogap temperature $T^*$.",2202.02589v1
+2022-03-05,Dimits transition in three-dimensional ion-temperature-gradient turbulence,"We extend our previous work on the 2D Dimits transition in ion-scale
+turbulence (Ivanov et al. 2020) to include variations along the magnetic field.
+We consider a three-field fluid model for the perturbations of electrostatic
+potential, ion temperature, and ion parallel flow in a
+constant-magnetic-curvature geometry without magnetic shear. It is derived in
+the cold-ion, long-wavelength asymptotic limit of the gyrokinetic theory. Just
+as in the 2D model, a low-transport (Dimits) regime exists and is found to be
+dominated by a quasi-static staircase-like arrangement of strong zonal flows
+and zonal temperature. This zonal staircase is formed and maintained by a
+negative turbulent viscosity for the zonal flows. Unlike the 2D model, the 3D
+one does not suffer from an unphysical blow up beyond the Dimits threshold
+where the staircase becomes nonlinearly unstable. Instead, a well-defined
+finite-amplitude saturated state is established. This qualitative difference
+between 2D and 3D is due to the appearance of small-scale `parasitic' modes
+that exist only if we allow perturbations to vary along the magnetic field
+lines. These modes extract energy from the large-scale perturbations and
+provide an effective enhancement of large-scale thermal diffusion, thus aiding
+the energy transfer from large injection scales to small dissipative ones. We
+show that in our model, the parasitic modes always favour a
+zonal-flow-dominated state. In fact, a Dimits state with a zonal staircase is
+achieved regardless of the strength of the linear drive provided the system is
+sufficiently extended along the magnetic field and sufficient parallel
+resolution is provided.",2203.02769v2
+2022-04-08,Electron Weibel instability induced magnetic fields in optical-field ionized plasmas,"Generation and amplification of magnetic fields in plasmas is a long-standing
+topic that is of great interest to both plasma and space physics. The electron
+Weibel instability is a well-known mechanism responsible for self-generating
+magnetic fields in plasmas with temperature anisotropy and has been extensively
+investigated in both theory and simulations, yet experimental verification of
+this instability has been challenging. Recently, we demonstrated a new
+experimental platform that enables the controlled initialization of highly
+nonthermal and/or anisotropic plasma electron velocity distributions via
+optical-field ionization. Using an external electron probe bunch from a linear
+accelerator, the onset, saturation and decay of the self-generated magnetic
+fields due to electron Weibel instability were measured for the first time to
+our knowledge. In this paper, we will first present experimental results on
+time-resolved measurements of the Weibel magnetic fields in non-relativistic
+plasmas produced by Ti:Sapphire laser pulses (0.8 $\mu m$) and then discuss the
+feasibility of extending the study to quasi-relativistic regime by using
+intense $\rm CO_2$ (e.g., 9.2 $\mu m$) lasers to produce much hotter plasmas.",2204.04262v1
+2022-04-20,Ferrimagnet GdFeCo characterization for spin-orbitronics: large field-like and damping-like torques,"Spintronics is showing promising results in the search for new materials and
+effects to reduce energy consumption in information technology. Among these
+materials, ferrimagnets are of special interest, since they can produce large
+spin currents that trigger the magnetization dynamics of adjacent layers or
+even their own magnetization. Here, we present a study of the generation of
+spin current by GdFeCo in a GdFeCo/Cu/NiFe trilayer where the FeCo sublattice
+magnetization is dominant at room temperature. Magnetic properties such as the
+saturation magnetization are deduced from magnetometry measurements while
+damping constant is estimated from spin-torque ferromagnetic resonance
+(ST-FMR). We show that the overall damping-like (DL) and field-like (FL)
+effective fields as well as the associated spin Hall angles can be reliably
+obtained by performing the dependence of ST-FMR by an added dc current. The sum
+of the spin Hall angles for both the spin Hall effect (SHE) and the spin
+anomalous Hall effect (SAHE) symmetries are: $\theta_{DL}^{SAHE} +
+\theta_{DL}^{SHE}=-0.15 \pm 0.05$ and $\theta_{FL}^{SAHE} +
+\theta_{FL}^{SHE}=0.026 \pm 0.005$. From the symmetry of ST-FMR signals we find
+that $\theta_{DL}^{SHE}$ is positive and dominated by the negative
+$\theta_{DL}^{SAHE}$. The present study paves the way for tuning the different
+symmetries in spin conversion in highly efficient ferrimagnetic systems.",2204.09776v1
+2022-04-28,"Low-energy spin excitations of the frustrated ferromagnetic $J_1$-$J_2$ chain material linarite, PbCuSO$_4$(OH)$_2$, in applied magnetic fields $\mathbf{H} \parallel b$ axis","We report a study of the spin dynamics of the frustrated ferromagnetic
+$J_1$-$J_2$ chain compound linarite, PbCuSO$_4$(OH)$_2$, in applied magnetic
+fields up to field polarization. By means of an extreme-environment inelastic
+neutron scattering experiment, we have measured the low-energy spin excitations
+of linarite in fields up to 8.8 T for $\mathbf{H} \parallel b$ axis. We have
+recorded the spin excitation spectra along $h$, $k$ and $l$ for the
+field-induced magnetic phases IV, V and the field polarized state close to
+saturation. By employing first-principles calculations, we estimate the leading
+magnetic exchanges out of the $bc$ plane and model the dispersion relations
+using linear spin-wave theory. In this way, we find evidence for a (very weak)
+residual magnetic exchange coupling out of the $bc$ plane. Together with the
+previously established dominant intrachain couplings $J_1$ and $J_2$ and the
+interchain coupling $J_3$, we derive an effective set of exchange couplings for
+a microscopic description of linarite. Further, we find that the peculiar
+character of phase V manifests itself in the measured spin dynamics.",2204.13482v2
+2022-06-03,Engineering the spin-orbit torque efficiency and magnetic properties of Tb/Co ferrimagnetic multilayers by stacking order,"We measured the spin-orbit torques (SOTs), current-induced switching, and
+domain wall (DW) motion in synthetic ferrimagnets consisting of Co/Tb layers
+with differing stacking order grown on a Pt underlayer. We find that the SOTs,
+magnetic anisotropy, compensation temperature and SOT-induced switching are
+highly sensitive to the stacking order of Co and Tb and to the element in
+contact with Pt. Our study further shows that Tb is an efficient SOT generator
+when in contact with Co, such that its position in the stack can be adjusted to
+generate torques additive to those generated by Pt. With optimal stacking and
+layer thickness, the dampinglike SOT efficiency reaches up to 0.3, which is
+more than twice that expected from the Pt/Co bilayer. Moreover, the
+magnetization can be easily switched by the injection of pulses with current
+density of about 0.5-2*107A/cm2 despite the extremely high perpendicular
+magnetic anisotropy barrier (up to 7.8 T). Efficient switching is due to the
+combination of large SOTs and low saturation magnetization owing to the
+ferrimagnetic character of the multilayers. We observed current-driven DW
+motion in the absence of any external field, which is indicative of homochiral
+N\'eel-type DWs stabilized by the interfacial Dzyaloshinkii-Moriya interaction.
+These results show that the stacking order in transition metal/rare-earth
+synthetic ferrimagnets plays a major role in determining the magnetotransport
+properties relevant for spintronic applications.",2206.01586v1
+2022-09-12,Emergent magnetic states and tunable exchange bias at all 3d nitride heterointerfaces,"Interfacial magnetism stimulates the discovery of giant magnetoresistance and
+spin-orbital coupling across the heterointerfaces, facilitating the intimate
+correlation between spin transport and complex magnetic structures. Over
+decades, functional heterointerfaces composed of nitrides are seldomly explored
+due to the difficulty in synthesizing high-quality and correct composition
+nitride films. Here we report the fabrication of single-crystalline
+ferromagnetic Fe3N thin films with precisely controlled thickness. As film
+thickness decreasing, the magnetization deteriorates dramatically, and
+electronic state transits from metallic to insulating. Strikingly, the
+high-temperature ferromagnetism maintains in a Fe3N layer with a thickness down
+to 2 u. c. (~ 8 {\AA}). The magnetoresistance exhibits a strong in-plane
+anisotropy and meanwhile the anomalous Hall resistance reserves its sign when
+Fe3N layer thickness exceeds 5 u. c. Furthermore, we observe a sizable exchange
+bias at the interfaces between a ferromagnetic Fe3N and an antiferromagnetic
+CrN. The exchange bias field and saturation moment strongly depend on the
+controllable bending curvature using cylinder diameter engineering (CDE)
+technique, implying the tunable magnetic states under lattice deformation. This
+work provides a guideline for exploring functional nitride films and applying
+their interfacial phenomena for innovative perspectives towards the practical
+applications.",2209.05209v1
+2022-10-07,Role of magnetic fields in the formation of direct collapse black holes,"Direct collapse black holes (DCBHs) are the leading candidates for the origin
+of the first supermassive black holes. However, the role of magnetic fields
+during their formation is still unclear as none of the previous studies has
+been evolved long enough to assess their impact during the accretion phase.
+Here, we report the results from a suite of 3D cosmological
+magneto-hydrodynamic (MHD) simulations which are evolved for 1.6 Myrs
+comparable to the expected lifetime of supermassive stars (SMSs). Our findings
+suggest that magnetic fields are rapidly amplified by strong accretion shocks
+irrespective of the initial magnetic field strength and reach the saturation
+state. They stabilize the accretion disks and significantly reduce
+fragmentation by enhancing the Jeans mass in comparison with pure
+hydrodynamical runs. Although the initial clump masses are larger in MHD runs,
+the rapid coalescence of clumps in non-MHD cases due to the higher degree of
+fragmentation results in similar masses. Overall, the central clumps have
+masses of $\rm 10^5~M_{\odot}$ and the mean mass accretion rates of $\rm \sim
+0.1 ~M_{\odot}/yr$ are similar in both MHD and non-MHD cases. The multiplicity
+of SMSs is significantly reduced in MHD simulations. Such strongly amplified
+magnetic fields are expected to launch Jets and outflows which may be detected
+with upcoming radio telescopes.",2210.05611v2
+2023-03-08,Spin-valve nature and giant coercivity of a ferrimagnetic spin semimetal Mn$_2$IrGa,"Spin semimetals are amongst the most recently discovered new class of
+spintronic materials, which exhibit a band gap in one spin channel and
+semimetallic feature in the other, thus facilitating tunable spin transport.
+Here, we report Mn$_2$IrGa to be a candidate material for spin semimetal along
+with giant coercivity and spin-valve characteristics using a combined
+experimental and theoretical study. The alloy crystallizes in an inverse
+Heusler structure (without any martensitic transition) with a para- to
+ferri-magnetic transition at $T_\mathrm{C} \sim$ 243 K. It shows a giant
+coercive field of about 8.5 kOe (at 2 K). The negative temperature coefficient,
+relatively low magnitude and weak temperture dependance of electrical
+resistivity suggest the semimetallic character of the alloy. This is further
+supported by our specific heat measurement. Magnetoresistance (MR) confirms an
+irreversible nature (with its magnitude $\sim$1\%) along with a change of sign
+across the magnetic transition indicating the potentiality of Mn$_2$IrGa in
+magnetic switching applications. In addition, asymmetric nature of MR in the
+positive and negative field cycles is indicative of spin-valve characteristics.
+Our ab-initio calculations confirm the inverse Heusler structure with
+ferrimagnetic ordering to be the lowest energy state, with a saturation
+magnetization of 2 $\mu_\mathrm{B}$. $<100>$ is found to be the easy magnetic
+axis with considerable magneto-crystalline anisotropy energy. A large positive
+Berry flux at/around $\Gamma$ point gives rise to an appreciable anomalous Hall
+conductivity ($\sim$-180 S/cm).",2303.04649v2
+2023-06-08,Epitaxial thin films of binary Eu-compounds close to a valence transition,"Intermetallic binary compounds of europium reveal a variety of interesting
+phenomena due to the interconnection between two different magnetic and 4f
+electronic (valence) states, which are particularly close in energy. The
+valence states or magnetic properties are thus particularly sensitive to
+strain-tuning in these materials. Consequently, we grew epitaxial EuPd$_2$
+(magnetic Eu$^{2+}$) and EuPd$_3$ (nonmagnetic Eu$^{3+}$) thin films on
+MgO(001) substrates using molecular beam epitaxy. Ambient X-ray diffraction
+confirms an epitaxial relationship of cubic Laves-type (C15) EuPd$_2$ with an
+(111)-out-of-plane orientation, whereby eight distinct in-plane
+crystallographic domains develop. For simple cubic EuPd$_3$ two different
+out-of-plane orientations can be obtained by changing the substrate annealing
+temperature under ultra-high vacuum conditions from 600 {\deg}C to 1000 {\deg}C
+for one hour. A small resistance minimum evolves for EuPd$_3$ thin films grown
+with low temperature substrate annealing, which was previously found even in
+single crystals of EuPd$_3$ and might be attributed to a Kondo or weak
+localization effect. Absence of influence of an applied magnetic fields and
+magnetotransport measurements suggest a nonmagnetic ground state for EuPd$_3$
+thin films, i. e., a purely trivalent Eu valence, as found in EuPd$_3$ single
+crystals. For EuPd$_2$ magnetic ordering below ~72 K is observed, quite similar
+to single crystal behavior. Field dependent measurements of the
+magnetoresistance and the Hall effect show hysteresis effects below ~0.4 T and
+an anomalous Hall effect below ~70 K, which saturates around 1.4 T, thus
+proving a ferromagnetic ground state of the divalent Eu.",2306.05355v2
+2023-07-14,Degaussing Procedure and Performance Enhancement by Low-Frequency Shaking of a 3-Layer Magnetically Shielded Room,"We report on the performance of a Magnetically Shielded Room (MSR) intended
+for next level $^3$He/$^{129}$Xe co-magnetometer experiments which require
+improved magnetic conditions. The MSR consists of three layers of Mu-metal with
+a thickness of 3 mm each, and one additional highly conductive copper-coated
+aluminum layer with a thickness of 10 mm. It has a cubical shape with an
+walk-in interior volume with an edge length of 2560 mm. An optimized degaussing
+(magnetic equilibration) procedure using a frequency sweep with constant
+amplitude followed by an exponential decay of the amplitude will be presented.
+The procedure for the whole MSR takes 21 minutes and measurements of the
+residual magnetic field at the center of the MSR show that $|B|<1$ nT can be
+reached reliably. The chosen degaussing procedure will be motivated by online
+hysteresis measurements of the assembled MSR and by Eddy current simulations
+showing that saturation at the center of the Mu-metal layer is reached.
+Shielding Factors can be improved by a factor $\approx 4$ in all directions by
+low frequency (0.2 Hz), low current (1 A) shaking of the outermost Mu-metal
+layer.",2307.07225v1
+2023-10-23,Regulating star formation in a magnetized disk galaxy,"We use high-resolution MHD simulations of isolated disk galaxies to
+investigate the co-evolution of magnetic fields with a self-regulated,
+star-forming interstellar medium (ISM). The simulations are conducted using the
+Ramses AMR code on the standard Agora initial condition, with gas cooling, star
+formation and feedback. We run galaxies with a variety of initial magnetic
+field strengths. The fields grow rapidly and achieve approximate saturation
+within 500 Myr, but at different levels. The galaxies reach a quasi-steady
+state, with slowly declining star formation due to both gas consumption and
+increases in the field strength at intermediate ISM densities. We connect this
+behaviour to differences in the gas properties and overall structure of the
+galaxies. In particular, strong fields limit feedback bubbles. Different cases
+support the ISM using varying combinations of magnetic pressure, turbulence and
+thermal energy. Magnetic support is closely linked to stellar feedback in the
+case of initially weak fields but not for initially strong fields. The spatial
+distribution of these supports is also different in each case, and this is
+reflected in the stability of the gas disk. We relate this back to the overall
+distribution of star formation in each case. We conclude that a weak initial
+field can grow to produce a realistic model of a local disk galaxy, but
+starting with typical field strengths will not.",2310.15244v1
+2024-01-08,Microwave-assisted synthesis of LaMnO3+d: Tuning physical properties with microwave power,"Synthesis of transition metal oxides by microwave irradiation is a faster and
+energy-saving method compared to conventional heating in an electrical furnace
+because microwave energy is directly converted into heat within precursors.
+However, not much is known about how the physical properties are modified by
+the power of microwaves. We synthesized LaMnO3+d by irradiating oxide
+precursors with microwaves and studied the impact of microwave power (P = 1000
+W, 1200 W, 1400 W and 1600 W) on magnetism, resistivity, magnetoresistance,
+thermopower, magnetic entropy change, magnetostriction, and electron spin
+resonance. It is found that paramagnetic to ferromagnetic transition becomes
+sharper, saturation magnetization increases, and electrical resistivity at low
+temperatures dramatically decreases as P increases. While the resistivity of
+samples irradiated with MW power of P less than or equal to 1400 W show
+insulating-like behavior down to 50 K, an insulator-metal transition occurs in
+the sample exposed to P = 1600 W and this sample also shows a maximum
+magnetoresistance (= -55%), magneto-thermopower (=-87%), magnetostriction (-180
+x10-6) for H = 50 kOe and magnetic entropy change of 4.78 J/kg. K for H = 30
+kOe around the Curie temperature. The intensity of electron spin resonance
+spectra at 300 K increases with P. We postulate that the much enhanced physical
+properties observed for the P = 1600 W sample arise from the creation of higher
+hole density, chemical homogeneity, and increased grain size. Our study shows
+that microwave power can be used as a knob to tune magnetism and other physical
+properties to our advantage.",2401.04087v1
+2024-02-21,Field-induced electric polarization and elastic softening caused by parity-mixed $d$-$p$ hybridized states with electric multipoles in Ba$_2$CuGe$_2$O$_7$,"We performed high-magnetic-field magnetization, polarization, and ultrasonic
+measurements in Ba$_2$CuGe$_2$O$_7$ to investigate field-induced multiferroic
+properties arising from a cross-correlation between electric dipoles and
+electric quadrupoles in addition to cross-correlation between magnetic dipoles
+and electric dipoles. Magnetization $M$ shows saturation behavior above 20 T
+for several magnetic field directions, however, electric polarization $P_c$
+exhibits an increase, and elastic constants show a softening above 20 T. Based
+on quantum states with a crystalline electric field for the $D_{2d}$ point
+group and $d$-$p$ hybridization between Cu-$3d$ and O-$2p$ electrons, we
+confirmed that the matrix of an electric dipole $P_z$ was proportional to that
+of an electric quadrupole $O_{xy}$. Furthermore, considering the spin-orbit
+coupling of $3d$ electrons and the Zeeman effect, we showed that $P_z$ and
+$O_{xy}$ simultaneously exhibited field-induced responses. These findings
+indicate that the orbital degrees of freedom, in addition to the spin degrees
+of freedom, contribute to the high-field multiferroicity in
+Ba$_2$CuGe$_2$O$_7$.",2402.13504v1
+2024-03-26,"Nanoparticles of NbC produced by laser ablation in liquid: a study of structural, magnetic and superconductivity properties","Niobium carbide (NbC) is a high-field Type II superconductor with a critical
+temperature ($T_C$) of 11.1 K, just above that of pure Nb ($T_C = 9$ K).
+Downsizing NbC to the nanoparticle scale introduces significant alterations in
+its critical field and/or the superconducting temperature. Here we report on
+superconducting NbC nanoparticles with $T_C \approx$ 10 K synthesized by laser
+ablation in acetone, using the lens-target distance (laser fluence) and
+centrifugation as control parameters of the particle size. X-ray diffraction
+analyses certified the cubic NbC phase and electron microscopy images revealed
+spherical particles with average size near 8 nm, with no apparent size
+dependence on fluence. Besides, magnetization curves exhibited magnetic loops
+featuring a saturation magnetization around $10^{-3} \mu_B$/molecule along with
+a small and typical superconducting loop for all investigated samples. We also
+observed a suppression of the diamagnetic behavior below $T_C$ upon decreasing
+laser fluence. Moreover, all samples exhibited a weak electron spin resonance
+(ESR) Curie-like signal at $g\approx2.0$ probably associated with localized
+defects in the particle's surface. The intriguing coexistence of
+superconductivity and magnetism in nanoparticles has recently garnered
+significant research attention. This complex scenario and unique properties are
+due to the substantial increase of surface-to-volume ratio in these
+superconducting NbC nanoparticles and further investigation would be crucial to
+unveil novel material properties and shed new light on our understanding of the
+superconducting phenomenon in this new morphology.",2403.18022v1
+2010-08-10,Bridging frustrated-spin-chain and spin-ladder physics: quasi-one-dimensional magnetism of BiCu2PO6,"We derive and investigate the microscopic model of the quantum magnet
+BiCu2PO6 using band structure calculations, magnetic susceptibility and
+high-field magnetization measurements, as well as ED and DMRG techniques. The
+resulting quasi-one-dimensional spin model is a two-leg AFM ladder with
+frustrating next-nearest-neighbor couplings along the legs. The individual
+couplings are estimated from band structure calculations and by fitting the
+magnetic susceptibility with theoretical predictions, obtained using ED. The
+nearest-neighbor leg coupling J1, the rung coupling J4, and one of the
+next-nearest-neighbor couplings J2 amount to 120-150 K, while the second
+next-nearest-neighbor coupling is J2'~J2/2. The spin ladders do not match the
+structural chains, and although the next-nearest-neighbor interactions J2 and
+J2' have very similar superexchange pathways, they differ substantially in
+magnitude due to a tiny difference in the O-O distances and in the arrangement
+of non-magnetic PO4 tetrahedra. An extensive ED study of the proposed model
+provides the low-energy excitation spectrum and shows that the system is in the
+strong rung coupling regime. The strong frustration by the
+next-nearest-neighbor couplings leads to a triplon branch with an
+incommensurate minimum. This is further corroborated by a strong-coupling
+expansion up to second order in the inter-rung coupling. Based on high-field
+magnetization measurements, we estimate the spin gap of 32 K and suggest the
+likely presence of antisymmetric DM anisotropy and inter-ladder coupling J3. We
+also provide a tentative description of the physics of BiCu2PO6 in magnetic
+field, in the light of the low-energy excitation spectra and numerical
+calculations based on ED and DMRG. In particular, we raise the possibility for
+a rich interplay between one- and two-component Luttinger liquid phases and a
+magnetization plateau at 1/2 of the saturation value.",1008.1771v2
+2011-10-03,Structural and magnetic characterization of the complete delafossite solid solution (CuAlO2){1-x}(CuCrO2){x},"We have prepared the complete delafossite solid solution series between
+diamagnetic CuAlO2 and the t2g^3 frustrated antiferromagnet CuCrO2. The
+evolution with composition x in CuAl(1-x)Cr(x)O2 of the crystal structure and
+magnetic properties has been studied and is reported here. The room-temperature
+unit cell parameters follow the Vegard law and increase with x as expected. The
+effective moment is equal to the Cr^3+ spin-only S = 3/2 value throughout the
+entire solid solution. Theta is negative, indicating that the dominant
+interactions are antiferromagnetic, and its magnitude increases with Cr
+substitution. For dilute Cr compositions, J_BB was estimated by mean-field
+theory to be 2.0 meV. Despite the sizable Theta, long-range antiferromagnetic
+order does not develop until very large x, and is preceeded by glassy behavior.
+Data presented here, and that on dilute Al-substitution from Okuda et al.,
+suggest that the reduction in magnetic frustration due to the presence of
+non-magnetic Al does not have as dominant an effect on magnetism as chemical
+disorder and dilution of the magnetic exchange. For all samples, the 5 K
+isothermal magnetization does not saturate in fields up to 5 T and minimal
+hysteresis is observed. The presence of antiferromagnetic interactions is
+clearly evident in the sub-Brillouin behavior with a reduced magnetization per
+Cr atom. An inspection of the scaled Curie plot reveals that significant
+short-range antiferromagnetic interactions occur in CuCrO2 above its Neel
+temperature, consistent with its magnetic frustration. Uncompensated
+short-range interactions are present in the Al-substituted samples and are
+likely a result of chemical disorder.",1110.0250v3
+2012-01-19,General Relativistic Magnetohydrodynamic Simulations of Magnetically Choked Accretion Flows around Black Holes,"Black hole (BH) accretion flows and jets are qualitatively affected by the
+presence of ordered magnetic fields. We study fully three-dimensional global
+general relativistic magnetohydrodynamic (MHD) simulations of radially extended
+and thick (height $H$ to cylindrical radius $R$ ratio of $|H/R|\sim 0.2--1$)
+accretion flows around BHs with various dimensionless spins ($a/M$, with BH
+mass $M$) and with initially toroidally-dominated ($\phi$-directed) and
+poloidally-dominated ($R-z$ directed) magnetic fields. Firstly, for toroidal
+field models and BHs with high enough $|a/M|$, coherent large-scale (i.e. $\gg
+H$) dipolar poloidal magnetic flux patches emerge, thread the BH, and generate
+transient relativistic jets. Secondly, for poloidal field models, poloidal
+magnetic flux readily accretes through the disk from large radii and builds-up
+to a natural saturation point near the BH. For sufficiently high $|a/M|$ or low
+$|H/R|$ the polar magnetic field compresses the inflow into a geometrically
+thin highly non-axisymmetric ""magnetically choked accretion flow"" (MCAF) within
+which the standard linear magneto-rotational instability is suppressed. The
+condition of a highly-magnetized state over most of the horizon is optimal for
+the Blandford-Znajek mechanism that generates persistent relativistic jets with
+$\gtrsim 100$% efficiency for $|a/M|\gtrsim 0.9$. A magnetic Rayleigh-Taylor
+and Kelvin-Helmholtz unstable magnetospheric interface forms between the
+compressed inflow and bulging jet magnetosphere, which drives a new jet-disk
+quasi-periodic oscillation (JD-QPO) mechanism. The high-frequency QPO has
+spherical harmonic $|m|=1$ mode period of $\tau\sim 70GM/c^3$ for $a/M\sim 0.9$
+with coherence quality factors $Q\gtrsim 10$. [abridged]",1201.4163v3
+2012-03-17,Electrical transport properties of nanostructured ferromagnetic perovskite oxides La_0.67Ca_0.33MnO_3 and La_0.5Sr_0.5CoO_3 at low temperatures (5 K > T >0.3 K) and high magnetic field,"We report a comprehensive study of the electrical and magneto-transport
+properties of nanocrystals of La_0.67Ca_0.33MnO_3 (LCMO) (with size down to 15
+nm) and La_0.5Sr_0.5CoO_3 (LSCO) (with size down to 35 nm) in the temperature
+range 0.3 K to 5 K and magnetic fields upto 14 T. The transport,
+magnetotransport and non-linear conduction (I-V curves) were analysed using the
+concept of Spin Polarized Tunnelling in the presence of Coulomb blockade. The
+activation energy of transport, \Delta, was used to estimate the tunnelling
+distances and the inverse decay length of the tunnelling wave function (\chi)
+and the height of the tunnelling barrier (\Phi_B). The magnetotransport data
+were used to find out the magnetic field dependences of these tunnelling
+parameters. The data taken over a large magnetic field range allowed us to
+separate out the MR contributions at low temperatures arising from tunnelling
+into two distinct contributions. In LCMO, at low magnetic field, the transport
+and the MR are dominated by the spin polarization, while at higher magnetic
+field the MR arises from the lowering of the tunnel barrier by the magnetic
+field leading to an MR that does not saturate even at 14 T. In contrast, in
+LSCO, which does not have substantial spin polarization, the first contribution
+at low field is absent, while the second contribution related to the barrier
+height persists. The idea of inter-grain tunnelling has been validated by
+direct measurements of the non-linear I-V data in this temperature range and
+the I-V data was found to be strongly dependent on magnetic field. We made the
+important observation that a gap like feature (with magnitude ~ E_C, the
+Coulomb charging energy) shows up in the conductance g(V) at low bias for the
+systems with smallest nanocrystal size at lowest temperatures (T < 0.7 K). The
+gap closes as the magnetic field and the temperature are increased.",1203.3873v1
+2013-10-30,Extraction of 3D field maps of magnetic multipoles from 2D surface measurements with applications to the optics calculations of the large-acceptance superconducting fragment separator BigRIPS,"The fringing fields of magnets with large apertures and short lengths greatly
+affect ion-optical calculations. In particular, for a high magnetic field where
+the iron core becomes saturated, the effective lengths and shapes of the field
+distribution must be considered because they change with the excitation
+current. Precise measurement of the three-dimensional magnetic fields and the
+correct application of parameters in the ion-optical calculations are
+necessary. First we present a practical numerical method of extracting full 3D
+magnetic field maps of magnetic multipoles from 2D field measurements of the
+surface of a cylinder. Using this novel method we extracted the distributions
+along the beam axis for the coefficient of the first-order quadrupole
+component, which is the leading term of the quadrupole components in the
+multipole expansion of magnetic fields and proportional to the distance from
+the axis. Higher order components of the 3D magnetic field can be extracted
+from the leading term via recursion relations. The measurements were done for
+many excitation current values for the large-aperture superconducting triplet
+quadrupole magnets (STQs) in the BigRIPS fragment separator at the RIKEN
+Nishina Center RI Beam Factory. These distributions were parameterized using
+the Enge functions to fit the fringe field shapes at all excitation current
+values, so that unmeasured values are interpolated. The extracted distributions
+depend only on the position along the beam axis, and thus the measured
+three-dimensional field can easily be parameterized for ion-optical
+calculations. We implemented these parameters in the ion-optical calculation
+code COSY INFINITY and realized a first-order calculation that incorporates the
+effect of large and varying fringe fields more accurately. We applied the
+calculation to determine the excitation current settings of the STQs...",1310.8336v1
+2013-12-09,Strong ferromagnetism at the surface of an antiferromagnet caused by buried magnetic moments,"Carrying a large, pure spin magnetic moment of 7 $\mu$bohr/atom in the
+half-filled 4f shell, divalent europium is an outstanding element for
+assembling novel magnetic devices in which a two-dimensional electron gas
+(2DEG) is polarized due to exchange interaction with an underlying
+magnetically-active Eu layer, even in the absence of a magnetic field. A
+natural example for such geometry is the intermetallic layered material
+EuRh$_2$Si$_2$, in which magnetically active layers of Eu are well separated
+from each other by non-magnetic Si-Rh-Si trilayers. Applying angle-resolved
+photoelectron spectroscopy (ARPES) to this system, we discovered a large spin
+splitting of a Shockley-type surface state formed by itinerant electrons of the
+Si-Rh-Si surface related trilayer. ARPES shows that the splitting sets in below
+approx. 32.5K and quickly saturates to around 150meV upon cooling.
+Interestingly, this temperature is substantially higher than the order
+temperature of the Eu 4f moments (approx. 24.5K) in the bulk. Our results
+clearly show that the magnetic exchange interaction between the surface state
+and the buried 4f moments in the 4th subsurface layer is the driving force for
+the formation of itinerant ferromagnetism at the surface. We demonstrate that
+the observed spin splitting of the surface state, reflecting properties of
+2DEG, is easily controlled by temperature. Such a splitting may also be induced
+into states of functional surface layers deposited onto the surface of
+EuRh$_2$Si$_2$ or similarly ordered magnetic materials with metallic or
+semiconducting properties.",1312.2508v1
+2014-03-18,Exploring high temperature magnetic order in CeTi_1-xSc_xGe,"Most of magnetic transitions related to Ce ordering are found below
+T_ord~12K. Among the few cases exceeding that temperature, two types of
+behaviors can be distinguished. One of them is related to the rare cases of Ce
+binary compounds formed in BCC structures, with a quartet ground state, whose
+degeneracy is reduced by undergoing different types of transitions mostly
+structural. The other group shows evidences of itinerant character with the
+outstanding example of CeRh_3B_2 showing the highest T_ord=115K. The second
+highest ordering temperature has been reported for CeScGe with T_ord=47K, but
+the nature of this magnetic state has not been investigated very deeply. In
+order to shed more light into this unusual high temperature ordering we studied
+the structural, magnetic, transport and thermal properties of CeTi_1-xSc_xGe
+alloys in the stability range of the CeScSi-type structure 0.25<x<1 This system
+presents a rich variety of magnetic behaviors along this concentration range,
+with the magnetic ordering growing from ferromagnetic (FM) T_C~7K up to an
+antiferromagnetic (AFM) transition at T_N=47K. The different regions show the
+following characteristics: i) on the Ti rich side (0.25<x<0.50) it exhibits a
+FM ground state (GS) with large saturation magnetization values M_sat up to
+~1.15 mu_B. ii) Around x=0.60, the first crystal electric field excited doublet
+starts to contribute to the GS magnetic properties. Furthermore an AFM
+component with a connected metamagnetic transition appears. iii) At x=0.65 a
+clear change in the GS nature is associated to a critical point above which the
+GS properties can be described like for an itinerant system (with decreasing
+M_sat) and an effective GS degeneracy N_eff=4. iv) For x>0.65, the magnetic
+phase boundary splits into two transitions, with an intermediate phase
+presenting incommensurate spin density waves features.",1403.4490v1
+2015-02-20,Magnetic properties of (Fe$_{1-x}$Co$_x$)$_2$B alloys and the effect of doping by 5$d$ elements,"We have explored, computationally and experimentally, the magnetic properties
+of \fecob{} alloys. Calculations provide a good agreement with experiment in
+terms of the saturation magnetization and the magnetocrystalline anisotropy
+energy with some difficulty in describing Co$_2$B, for which it is found that
+both full potential effects and electron correlations treated within dynamical
+mean field theory are of importance for a correct description. The material
+exhibits a uniaxial magnetic anisotropy for a range of cobalt concentrations
+between $x=0.1$ and $x=0.5$. A simple model for the temperature dependence of
+magnetic anisotropy suggests that the complicated non-monotonous temperature
+behaviour is mainly due to variations in the band structure as the exchange
+splitting is reduced by temperature. Using density functional theory based
+calculations we have explored the effect of substitutional doping the
+transition metal sublattice by the whole range of 5$d$ transition metals and
+found that doping by Re or W elements should significantly enhance the
+magnetocrystalline anisotropy energy. Experimentally, W doping did not succeed
+in enhancing the magnetic anisotropy due to formation of other phases. On the
+other hand, doping by Ir and Re was successful and resulted in magnetic
+anisotropies that are in agreement with theoretical predictions. In particular,
+doping by 2.5~at.\% of Re on the Fe/Co site shows a magnetocrystalline
+anisotropy energy which is increased by 50\% compared to its parent
+(Fe$_{0.7}$Co$_{0.3}$)$_2$B compound, making this system interesting, for
+example, in the context of permanent magnet replacement materials or in other
+areas where a large magnetic anisotropy is of importance.",1502.05916v3
+2016-06-07,A moving mesh unstaggered constrained transport scheme for magnetohydrodynamics,"We present a constrained transport (CT) algorithm for solving the 3D ideal
+magnetohydrodynamic (MHD) equations on a moving mesh, which maintains the
+divergence-free condition on the magnetic field to machine-precision. Our CT
+scheme uses an unstructured representation of the magnetic vector potential,
+making the numerical method simple and computationally efficient. The scheme is
+implemented in the moving mesh code Arepo. We demonstrate the performance of
+the approach with simulations of driven MHD turbulence, a magnetized disc
+galaxy, and a cosmological volume with primordial magnetic field. We compare
+the outcomes of these experiments to those obtained with a previously
+implemented Powell divergence-cleaning scheme. While CT and the Powell
+technique yield similar results in idealized test problems, some differences
+are seen in situations more representative of astrophysical flows. In the
+turbulence simulations, the Powell cleaning scheme artificially grows the mean
+magnetic field, while CT maintains this conserved quantity of ideal MHD. In the
+disc simulation, CT gives slower magnetic field growth rate and saturates to
+equipartition between the turbulent kinetic energy and magnetic energy, whereas
+Powell cleaning produces a dynamically dominant magnetic field. Such difference
+has been observed in adaptive-mesh refinement codes with CT and
+smoothed-particle hydrodynamics codes with divergence-cleaning. In the
+cosmological simulation, both approaches give similar magnetic amplification,
+but Powell exhibits more cell-level noise. CT methods in general are more
+accurate than divergence-cleaning techniques, and, when coupled to a moving
+mesh can exploit the advantages of automatic spatial/temporal adaptivity and
+reduced advection errors, allowing for improved astrophysical MHD simulations.",1606.02310v2
+2016-12-12,Hall-effect Mediated Magnetic Flux Transport in Protoplanetary Disks,"The global evolution of protoplanetary disks (PPDs) has recently been shown
+to be largely controlled by the amount of poloidal magnetic flux threading the
+disk, which is further controlled by the poorly understood process of magnetic
+flux transport. In weakly ionized gas as in PPDs, magnetic flux is largely
+frozen in the electron fluid, except when resistivity is large. When the disk
+is largely laminar, we show that the relative drift between the electrons and
+ions (the Hall-drift), and the ions and neutral fluids (ambipolar-drift) can
+play a dominant role on the transport of magnetic flux. Using two-dimensional
+simulations that incorporate the Hall effect and ambipolar diffusion (AD) with
+prescribed diffusivities, we show that when large-scale poloidal field is
+aligned with disk rotation, the Hall effect rapidly drags magnetic flux inward
+at the midplane region, while it slowly pushes flux outward above/below the
+midplane. This leads to a highly radially elongated field configuration as a
+global manifestation of the Hall-shear instability. This field configuration
+further promotes rapid outward flux transport by AD at the midplane, leading to
+instability saturation. In quasi-steady state, magnetic flux is transported
+outward at approximately the same rate at all heights, and the rate is
+comparable to the Hall-free case. For anti-aligned field polarity, the Hall
+effect consistently transports magnetic flux outward, leading to a largely
+vertical field configuration in the midplane region. The field lines in the
+upper layer first bend radially inward and then outward to launch a disk wind.
+Overall, the net rate of outward flux transport is about twice faster than the
+aligned case. In addition, the rate of flux transport increases with increasing
+disk magnetization. The absolute rate of transport is sensitive to disk
+microphysics which remains to be explored in future studies.",1612.03912v1
+2019-06-09,Spin dynamics and unconventional magnetism in insulating La$_{(1-2x)}$Sr$_{2x}$Co$_{(1-x)}$Nb$_{x}$O$_3$,"We study the structural, magnetic, transport and electronic properties of
+LaCoO$_3$ with Sr/Nb co-substitution, i.e.,
+La$_{(1-2x)}$Sr$_{2x}$Co$_{(1-x)}$Nb$_{x}$O$_3$ using x-ray and neutron
+diffraction, dc and ac-magnetization, neutron depolarization, dc-resistivity
+and photoemission measurements. The powder x-ray and neutron diffraction data
+were fitted well with the rhombohedral crystal symmetry (space group
+\textit{R$\bar{3}$c}) in Rietveld refinement analysis. The calculated effective
+magnetic moment ($\approx$3.85~$\mu_B$) and average spin ($\approx$1.5) of Co
+ions from the analysis of magnetic susceptibility data are consistent with 3+
+state of Co ions in intermediate-spin (IS) and high-spin (HS) states in the
+ratio of $\approx$50:50, i.e., spin-state of Co$^{3+}$ is preserved at least up
+to $x=$ 0.1 sample. Interestingly, the magnetization values were significantly
+increased with respect to the $x=$ 0 sample, and the M-H curves show
+non-saturated behavior up to an applied maximum magnetic field of $\pm$70 kOe.
+The ac-susceptibility data show a shift in the freezing temperature with
+excitation frequency and the detailed analysis confirm the slower dynamics and
+a non-zero value of the Vogel-Fulcher temperature T$_0$, which suggests for the
+cluster spin glass. The unusual magnetic behavior indicates the presence of
+complex magnetic interactions at low temperatures. The dc-resistivity
+measurements show the insulating nature in all the samples. However, relatively
+large density of states $\approx$10$^{22}$ eV$^{-1}$cm$^{-3}$ and low
+activation energy $\approx$130~meV are found in $x=$ 0.05 sample. Using x-ray
+photoemission spectroscopy, we study the core-level spectra of La 3$d$, Co
+2$p$, Sr 3$d$, and Nb 3$d$ to confirm the valence state.",1906.03659v1
+2019-09-18,Neutron diffraction and magnetic properties of Co$_2$Cr$_{1-x}$Ti$_x$Al Heusler alloys,"We report the structural, magnetic, and magnetocaloric properties of
+Co$_2$Cr$_{1-x}$Ti$_x$Al ($x=$ 0--0.5) Heusler alloys for spintronic and
+magnetic refrigerator applications. Room temperature X-ray diffraction and
+neutron diffraction patterns along with Rietveld refinements confirm that the
+samples are of single phase and possess a cubic structure. Interestingly,
+magnetic susceptibly measurements indicate a second order phase transition from
+paramagnetic to ferromagnetic where the Curie temperature (T$_{\rm C}$) of
+Co$_2$CrAl increases from 330~K to 445~K with Ti substitution. Neutron powder
+diffraction data of the $x=$ 0 sample across the magnetic phase transition
+taken in a large temperature range confirm the structural stability and exclude
+the possibility of antiferromagnetic ordering. The saturation magnetization of
+the $x=$ 0 sample is found to be 8000~emu/mol (1.45~$\mu_{\rm B}$/{\it f.u.})
+at 5~K, which is in good agreement with the value (1.35$\pm$0.05~$\mu_{\rm
+B}$/{\it f.u.}) obtained from the Rietveld analysis of the neutron powder
+diffraction pattern measured at temperature of 4~K. By analysing the
+temperature dependence of the neutron data of the $x=$ 0 sample, we find that
+the change in the intensity of the most intense Bragg peak (220) is consistent
+with the magnetization behavior with temperature. Furthermore, an enhancement
+of change in the magnetic entropy and relative cooling power values has been
+observed for the $x=$ 0.25 sample. Interestingly, the critical behavior
+analysis across the second order magnetic phase transition and extracted
+exponents ($\beta\approx$ 0.496, $\gamma\approx$ 1.348, and $\delta\approx$
+3.71 for the $x=$ 0.25 sample) suggest the presence of long-range ordering,
+which deviates towards 3D Heisenberg type interactions above T$_{\rm C}$,
+consistent with the interaction range value $\sigma$.",1909.08292v1
+2020-04-10,Ion beam modification of magnetic tunnel junctions,"The impact of 400 keV $Ar^+$ ion irradiation on the magnetic and electrical
+properties of in-plane magnetized magnetic tunnel junction (MTJ) stacks was
+investigated by ferromagnetic resonance, vibrating sample magnetometry and
+current-in-plane tunneling techniques. The irradiation-induced changes of the
+magnetic anisotropy, coupling energies and tunnel magnetoresistance (TMR)
+exhibited a correlated dependence on the ion fluence, which allowed us to
+distinguish between two irradiation regimes. In the low-fluence regime, ${\Phi}
+< 10^{14} cm^{-2}$, the parameters required for having a functioning MTJ were
+preserved: the anisotropy of the FeCoB free layer (FL) was weakly modulated
+following a small decrease in the saturation magnetization $M_S$; the TMR
+decreased continuously; the interlayer exchange coupling (IEC) and the exchange
+bias (EB) decreased slightly. In the high-fluence regime, ${\Phi} > 10^{14}
+cm^{-2}$, the MTJ was rendered inoperative: the modulation of the FL anisotropy
+was strong, caused by a strong decrease in $M_S$, ascribed to a high degree of
+interface intermixing between the FL and the Ta capping; the EB and IEC were
+also lost, likely due to intermixing of the layers composing the synthetic
+antiferromagnet; and the TMR vanished due to the irradiation-induced
+deterioration of the MgO barrier and MgO/FeCoB interfaces. We demonstrate that
+the layers surrounding the FL play a decisive role in determining the trend of
+the magnetic anisotropy evolution resulting from the irradiation, and that an
+ion-fluence window exists where such a modulation of magnetic anisotropy can
+occur, while not losing the TMR or the magnetic configuration of the MTJ.",2004.05025v1
+2020-07-18,Giant magneto-birefringence effect and tuneable colouration of 2D crystals' suspensions,"One of the long sought-after goals in manipulation of light through
+light-matter interactions is the realization of magnetic-field-tuneable
+colouration, so-called magneto-chromatic effect, which holds great promise for
+optical, biochemical and medical applications due to its contactless and
+non-invasive nature. This goal can be achieved by magnetic-field controlled
+birefringence, where colours are produced by the interference between
+phase-retarded components of transmitted polarised light. Thus far
+birefringence-tuneable coloration has been demonstrated using electric field,
+material chirality and mechanical strain but magnetic field control remained
+elusive due to either weak magneto-optical response of transparent media or low
+transmittance to visible light of magnetically responsive media, such as
+ferrofluids. Here we demonstrate magnetically tuneable colouration of aqueous
+suspensions of two-dimensional cobalt-doped titanium oxide which exhibit an
+anomalously large magneto-birefringence effect. The colour of the suspensions
+can be tuned over more than two wavelength cycles in the visible range by
+moderate magnetic fields below 0.8 T. We show that such giant magneto-chromatic
+response is due to particularly large phase retardation (>3 pi) of the
+polarised light, which in its turn is a combined result of a large
+Cotton-Mouton coefficient (three orders of magnitude larger than for known
+liquid crystals), relatively high saturation birefringence (delta n = 2 x
+10^-4) and high transparency of our suspensions to visible light. The work
+opens a new avenue to achieve tuneable colouration through engineered magnetic
+birefringence and can readily be extended to other magnetic 2D nanocrystals.
+The demonstrated effect can be used in a variety of magneto-optical
+applications, including magnetic field sensors, wavelength-tuneable optical
+filters and see-through printing.",2007.09388v1
+2022-11-28,Entropy engineering and tunable magnetic order in the spinel high entropy oxide,"Spinel oxides are an ideal setting to explore the interplay between
+configurational entropy, site selectivity, and magnetism in high entropy
+oxides. In this work we characterize the magnetic properties of the spinel
+(Cr,Mn,Fe,Co,Ni)$_3$O$_4$ and study the evolution of its magnetism as a
+function of non-magnetic gallium substitution. Across the range of compositions
+studied here, from 0% to 40% Ga, magnetic susceptibility and powder neutron
+diffraction measurements show that ferrimagnetic order is robust in the spinel
+HEO. However, we also find that the ferrimagnetic order is highly tunable, with
+the ordering temperature, saturated and sublattice moments, and magnetic
+hardness all varying significantly as a function of Ga concentration. Through
+x-ray absorption and magnetic circular dichroism, we are able to correlate this
+magnetic tunability with strong site selectivity between the various cations
+and the tetrahedral and octahedral sites in the spinel structure. In
+particular, we find that while Ni and Cr are largely unaffected by the
+substitution with Ga, the occupancies of Mn, Co, and Fe are each significantly
+redistributed. Ga substitution also requires an overall reduction in the
+transition metal valence, and this is entirely accommodated by Mn. Finally, we
+show that while site selectivity has an overall suppressing effect on the
+configurational entropy, over a certain range of compositions, Ga substitution
+yields a striking increase in the configurational entropy and may confer
+additional stabilization. Spinel oxides can be tuned seamlessly from the
+low-entropy to the high-entropy regime, making this an ideal platform for
+entropy engineering.",2211.15798v1
+2023-03-27,Magnetic properties of cobalt ultrathin film structures controlled by buffer layer roughness,"Growth optimization of multilayers is a topic of interest due to their unique
+physical properties. Systems containing magnetic materials, such as
+platinum-cobalt, have been studied because of their potential for technological
+applications, e.g. spintronics, magnetic storage and magnetic sensors. Since
+the magnetic properties of thin layers are strongly related to the growth
+parameters, the fine tuning of these parameters is necessary to produce
+multilayers with specific properties required in various applications. Here, an
+efficient approach to tune the coercive field of Co ultrathin films in the
+multilayer by varying the underlayer thickness is demonstrated. Using magnetron
+sputtering, we prepared multilayer systems of Au(x)/Pt(5nm)/Co(0.7nm)/Au(5nm)
+with various thicknesses of Au underlayer. The surface morphology of
+Au(x)/Pt(5nm) stack on which Co layer was deposited was studied by atomic force
+microscopy. We show the possibility to control the interfacial roughness by
+changing the Au underlayer thickness due to its island-like growth mechanism
+(Volmer-Weber mode). As the nominal thickness of Au increases, the islands grow
+in larger lateral size, resulting in a higher overall roughness of the layer
+surface. Magnetization measurements indicate a direct influence of the
+underlayer roughness on the coercivity of the multilayers by promoting
+additional magnetic anisotropy. With thickness of the Au layer up to 20 nm, we
+can change the coercive field in the range from ~200 Oe to ~1100 Oe, while
+remaining a nearly constant saturation magnetization. The use of Cu replacing
+Au underlayer in the same multilayers was also investigated, demonstrating the
+possibility of coercivity adjustment using different materials. The results are
+important for applications where the magnetic properties of multilayer
+structures based on Co thin films could be adjusted via buffer layer roughness
+engineering.",2303.15141v1
+2023-05-04,Influence of high pressure on the remarkable itinerant electron behaviour in Y$_{0.7}$Er$_{0.3}$Fe$_2$D$_{4.2}$ compounds,"Monoclinic Y$_{0.7}$Er$_{0.3}$Fe$_2$D$_{4.2}$ compound exhibits unusual
+magnetic properties with different field induced magnetic transitions. The
+deuteride is ferrimagnetic at low temperature and the Er and Fe sublattices
+present magnetic transitions at different temperatures. The Er moments are
+ordered below T$_{Er}$=55 K, whereas the Fe moments remain ferromagnetically
+coupled up to T$_{M0}$ = 66 K. At T$_{M0}$ the Fe moments display a sharp
+ferromagnetic-antiferromagnetic transition (FM-AFM) through an itinerant
+electron metamagnetic (IEM) behaviour very sensitive to any volume change.
+Y$_{0.7}$Er$_{0.3}$Fe$_2$D$_{4.2}$ becomes paramagnetic above T$_N$=125 K. The
+pressure dependence of T$_{Er}$ and T$_{M0}$ have been extracted from magnetic
+measurements under hydrostatic pressure up to 0.49 GPa. Both temperatures
+decrease linearly upon applied pressure with dT$_{Er}$/dP=-126 and dTM0/dP=-140
+K.GPa$^{-1}$ for a field of B=0.03 T. Both magnetic Er and ferromagnetic Fe
+order disappear at P=0.44(4) GPa. However, under a larger applied field B=5 T,
+dT$_{M0}$/dP=-156 K.GPa$^{-1}$ whereas dT$_{Er}$/dP=-134 K.GPa$^{-1}$ showing a
+weaker sensitivity to pressure and magnetic field. At 2 K the decrease of the
+saturation magnetization under pressure can be attributed to a reduction of the
+mean Er moment due to canting and/or crystal field effect. Above T$_{M0}$ the
+magnetization curves display a metamagnetic behaviour from AFM to FM state,
+which is also very sensitive to the applied pressure. The transition field
+B$_{trans}$, which increases linearly upon heating, is shifted to lower
+temperature upon applied pressure with dT=-17 K between 0 and 0.11 GPa. These
+results show a strong decoupling of the Er and Fe magnetic sublattices versus
+temperature, applied field and pressure.",2305.02698v1
+2023-05-23,Nano-Patterned Magnetic Edges in CrGeTe3 for Quasi 1-D Spintronic Devices,"The synthesis of two-dimensional van der Waals magnets has paved the way for
+both technological applications and fundamental research on magnetism confined
+to ultra-small length scales. Edge magnetic moments in ferromagnets are
+expected to be less magnetized than in the sample interior because of the
+reduced amount of neighboring ferromagnetic spins at the sample edge. We
+recently demonstrated that CrGeTe3 (CGT) flakes thinner than 10 nm are hard
+ferromagnets; i.e., they exhibit an open hysteresis loop. In contrast, thicker
+flakes exhibit zero net remnant field in the interior, with hard ferromagnetism
+present only at the cleaved edges. This experimental observation suggests that
+a nontrivial interaction exists between the sample edge and the interior. Here,
+we demonstrate that artificial edges fabricated by focus ion beam etching also
+display hard ferromagnetism. This enables us to write magnetic nanowires in CGT
+directly and use this method to characterize the magnetic interaction between
+the interior and edge. The results indicate that the interior saturation and
+depolarization fields depend on the lateral dimensions of the sample. Most
+notably, the interior region between the edges of a sample narrower than 300 nm
+becomes a hard ferromagnet, suggesting an enhancement of the magnetic exchange
+induced by the proximity of the edges. Last, we find that the CGT regions
+amorphized by the gallium beam are nonmagnetic, which introduces a novel method
+to tune the local magnetic properties of CGT films, potentially enabling
+integration into spintronic devices.",2305.14431v1
+2024-02-27,Modeling effects of starspots on stellar magnetic cycles,"Observations show that faster-rotating stars tend to have stronger magnetic
+activity and shorter magnetic cycles. The cyclical magnetic activity of the Sun
+and stars is believed to be driven by the dynamo process. The success of the
+Babcock-Leighton (BL) dynamo in understanding the solar cycle suggests an
+important role that starspots could play in stellar magnetic cycles. We aim at
+extending the BL mechanism to solar-mass stars with various rotation rates and
+explore the effects of emergence properties of starspots in latitudes and tilt
+angles on stellar magnetic cycles. We adopt a kinematic BL-type dynamo model
+operating in the bulk of the convection zone. The profiles of the large-scale
+flow fields are from the mean-field hydrodynamical model for various rotators.
+The BL source term in the model is constructed based on the rotation dependence
+of starspots emergence. That is, faster rotators have starspots at higher
+latitudes with larger tilt angles.Faster rotators have poloidal flux appearing
+closer to about $\pm55^\circ$ latitudes, where the toroidal field generation
+efficiency is the strongest because of the strongest latitudinal differential
+rotation there. It takes a shorter time for faster rotators to transport the
+surface poloidal field from their emergence latitude to the $\pm 55^\circ$
+latitudes of efficient $\Omega$-effect thus shortening their magnetic cycles.
+The faster rotators operate in a more supercritical regime due to a stronger BL
+$\alpha$-effect relating to the tilt angles, which leads to stronger saturated
+magnetic fields and a coupling of the poloidal field between two hemispheres
+more difficult. Thus the magnetic field parity shifts from the hemispherically
+asymmetric mixed mode to quadrupole, and further to dipole when a star spins
+down. The emergence of starspots plays an essential role in the large-scale
+stellar dynamo.",2402.17449v1
+2001-05-21,Saturation at low $x$,"This talk is an attempt to review all our knowledge on saturation at low $x$
+both theoretical and experimental, to stimulate a search for saturation effects
+at THERA. The main goals of this presentation are 1. To discuss an intuitive
+picture of the deep inelastic scattering that leads to the saturation of the
+parton densities;
+  2. To show that the saturation hypothesis has solid theoretical proof;
+  3. To report on the theoretical progress that has been made over the past two
+years in high parton density QCD, and on the property of the saturation phase
+that emerges from the theory that has been developed;
+  4. To collect all that we know theoretically and experimentally about the
+saturation scale $Q_s(x)$ .",0105205v1
+2010-03-09,Semiconductor saturable absorbers for ultrafast THz signals,"We demonstrate saturable absorber behavior of n-type semiconductors GaAs, GaP
+and Ge in THz frequency range at room temperature using nonlinear THz
+spectroscopy. The saturation mechanism is based on a decrease in electron
+conductivity of semiconductors at high electron momentum states, due to
+conduction band nonparabolicity and scattering into satellite valleys in strong
+THz fields. Saturable absorber parameters, such as linear and non-saturable
+transmission, and saturation fluence, are extracted by fits to a classic
+saturable absorber model. Further, we observe THz pulse shortening, and an
+increase of the group refractive index of the samples at higher THz pulse peak
+fields.",1003.1942v1
+2020-09-17,Exact saturation in pseudo-elementary classes for simple and stable theories,"We study PC-exact saturation for stable and simple theories. Among other
+results, we show that PC-exact saturation characterizes the stability cardinals
+of size at least continuum of a countable stable theory and, additionally, that
+simple unstable theories have PC-exact saturation at singular cardinals,
+satisfying mild set-theoretic hypotheses, which had previously been open even
+for the random graph. We characterize supersimplicity of countable theories in
+terms of having PC-exact saturation at singular cardinals of countable
+cofinality. We also consider the local analogue of PC-exact saturation, showing
+that local PC-exact saturation for singular cardinals of countable cofinality
+characterizes supershort theories.",2009.08365v2
+2005-10-07,Size-dependent magnetic properties of Nickel nano-chains,"Magnetic properties with 3 different sizes of Ni nanochains, synthesized by a
+technique of wet chemical solution, have been investigated experimentally. The
+sample sizes are 50 nm, 75 nm, and 150 nm with a typical length of a few
+microns. The characterizations by XRD and TEM reveal that the samples consist
+of Ni nano-particles forming one dimensional (1D) chain-like structure. The
+magnetic properties have been investigated by FC, ZFC measurements and M-H
+measurements. The results can be well explained within the context of
+core-shell model. First of all, the freezing of disordered spins in the shell
+layer have resulted in a peak-like structure on the ZFC curve. The peak
+position occurs around TF ~ 13 K. With the 50 nm sample, the field dependent
+behavior of TF(H) has been investigated in detail. It is well described by the
+de Almeida-Thouless (AT) equation for the surface spin glass state. Secondly,
+the shape anisotropy of 1D structure has caused a wide separation between the
+FC and ZFC curves. This is mainly attributed to the blocking of the core
+magnetism. Thirdly, by the M-H measurement in the low field region, the open
+hysteresis loop measured at 5 K < TF is significantly enlarged in comparison
+with that taken at T > TF. This indicates that a significant part of the
+contribution to the magnetic irreversibility at T < TF is coming from the
+disordered spins in the shell layer. Lastly, with reducing sample size, the
+coercivity, HC, increases, whereas the saturation magnetization goes down
+dramatically. These imply that, as the sample size reduces, the effect of shape
+anisotropy becomes larger in the magnetization reversal process and the
+contribution to the magnetism from the ferromagnetically ordered core becomes
+smaller.",0510168v2
+2012-02-22,Neutron Stars with Hyperons subject to Strong Magnetic Field,"Neutron stars are one of the most exotic objects in the universe and a unique
+laboratory to study the nuclear matter above the nuclear saturation density. In
+this work, we study the equation of state of the nuclear matter within a
+relativistic model subjected to a strong magnetic field. We then apply this EoS
+to study and describe some of the physical characteristics of neutron star,
+especially the mass-radius relation and chemical compositions. To study the
+influence of a the magnetic field and the hyperons in the stellar interior, we
+consider altogether four solutions: two different values of magnetic field to
+obtain a weak and a strong influence, and two configurations: a family of
+neutron stars formed only by protons, electrons and neutrons and a family
+formed by protons, electrons, neutrons, muons and hyperons. The limit and the
+validity of the results found are discussed with some care. In all cases the
+particles that constitute the neutron star are in $\beta$ equilibrium and zero
+total net charge. Our work indicates that the effect of a strong magnetic field
+has to be taken into account in the description of magnetars, mainly if we
+believe that there are hyperons in their interior, in which case, the influence
+of the magnetic field can increase the mass by more than 10%. We have also seen
+that although a magnetar can reach 2.48$M_{\odot}$, a natural explanation of
+why we do not know pulsars with masses above 2.0$M_{\odot}$ arises. We also
+discuss how the magnetic field affects the strangeness fraction in some
+standard neutron star masses and, to conclude our paper, we revisit the direct
+URCA process related to the cooling of the neutron stars and show how it is
+affected by the hyperons and the magnetic field.",1202.5016v2
+2016-05-23,Dynamical model for spindown of solar-type stars,"Since their formation, stars slow down their rotation rates by the removal of
+angular momentum from their surfaces, e.g. via stellar winds. Despite the
+complexity of the processes involved, a traditional model, where the removal of
+angular momentum loss by magnetic fields is prescribed, has provided a useful
+framework to understand observational relations between stellar rotation and
+age and magnetic field strength. Here, a spindown model is proposed where loss
+of angular momentum by magnetic fields is evolved dynamically, instead of being
+kinematically prescribed. To this end, we evolve the stellar rotation and
+magnetic field simultaneously over stellar evolution time by extending our
+previous work on a dynamo model which incorporates the nonlinear feedback
+mechanisms on rotation and magnetic fields. Our extended model reproduces key
+observations and explains the presence of the two branches of (fast and slow
+rotating) stars which have different relations between rotation rate $\Omega$
+vs. time (age), magnetic field strength $|B|$ vs. rotation rate, and frequency
+of magnetic field $\omega_{cyc}$ vs. rotation rate. For fast rotating stars we
+find: (i) an exponential spindown $\Omega \propto e^{-1.35t}$, with $t$
+measured in Gyrs, (ii) $|B|$ saturates for higher rotation rate, (iii)
+$\omega_{cyc} \propto \Omega^{0.85}$. For slow rotating stars we obtain: (i) a
+power law spindown $\Omega \propto t^{-0.52}$, (ii) $|B|$ scales almost
+linearly with rotation rate, (iii) $\omega_{cyc} \propto \Omega^{1.16}$. The
+results obtained are in good agreement with observations. The Vaughan-Preston
+gap is consistently explained in our model by the shortest spindown timescale
+in this transition from fast to slow rotators. Our results highlight the
+importance of self-regulation of magnetic fields and rotation by direct and
+indirect interactions involving nonlinear feedback in stellar evolution.",1605.07125v2
+2019-02-13,"Crystal growth, microstructure and physical properties of SrMnSb$_2$","We report on the crystal and magnetic structures, magnetic, and transport
+properties of SrMnSb$_2$ single crystals grown by the self-flux method.
+Magnetic susceptibility measurements reveal an antiferromagnetic (AFM)
+transition at $T_{\rm N} = 295(3)$ K. Above $T_{\rm N}$, the susceptibility
+slightly increases and forms a broad peak at $T \sim 420$ K, which is a typical
+feature of two-dimensional magnetic systems. Neutron diffraction measurements
+on single crystals confirm the previously reported C-type AFM structure below
+$T_{\rm N}$. Both de Haas-van Alphen (dHvA) and Shubnikov-de Haas (SdH) effects
+are observed in SrMnSb$_2$ single crystals. Analysis of the oscillatory
+component by a Fourier transform shows that the prominent frequencies obtained
+by the two different techniques are practically the same within error
+regardless of sample size or saturated magnetic moment. Transmission electron
+microscopy (TEM) reveals the existence of stacking faults in the crystals,
+which result from a horizontal shift of Sb atomic layers suggesting possible
+ordering of Sb vacancies in the crystals. Increase of temperature in
+susceptibility measurements leads to the formation of a strong peak at $T \sim
+{570}$ K that upon cooling under magnetic field the susceptibility shows a
+ferromagnetic transition at $T_{\rm C} \sim 580$ K. Neutron powder diffraction
+on crushed single-crystals does not support an FM phase above $T_{\rm N}$.
+Furthermore, X-ray magnetic circular dichroism (XMCD) measurements of a single
+crystal at the $L_{2,3}$ edge of Mn shows a signal due to induced canting of
+AFM moments by the applied magnetic field. All evidence strongly suggests that
+a chemical transformation at the surface of single crystals occurs above 500 K
+concurrently producing a minute amount of ferromagnetic impurity phase.",1902.04948v1
+2019-02-27,Fossil field decay due to nonlinear tides in massive binaries,"Surface magnetic fields have been detected in 5 to 10% of isolated massive
+stars, hosting outer radiative envelopes. They are often thought to have a
+fossil origin, resulting from the stellar formation phase. Yet, magnetic
+massive stars are scarcer in (close) short-period binaries, as reported by the
+BinaMIcS (Binarity and Magnetic Interaction in various classes of Stars)
+collaboration. Different physical conditions in the molecular clouds giving
+birth to isolated stars and binaries are commonly invoked. In addition, we
+propose that the observed lower magnetic incidence in close binaries may be due
+to nonlinear tides. Indeed, close binaries are probably prone to tidal
+instability, a fluid instability growing upon the equilibrium tidal flow via
+nonlinear effects. Yet, stratified effects have hitherto been largely
+overlooked. We theoretically and numerically investigate tidal instability in
+rapidly rotating, stably stratified fluids permeated by magnetic fields. We use
+the short-wavelength stability method to propose a comprehensive (local) theory
+of tidal instability at the linear onset, discussing damping effects. Then, we
+propose a mixing-length theory for the mixing generated by tidal instability in
+the nonlinear regime. We successfully assess our theoretical predictions
+against proof-of-concept, direct numerical simulations. Finally, we compare our
+predictions with the observations of short-period, double-lined spectroscopic
+binary systems. Using new analytical results, cross-validated by a direct
+integration of the stability equations, we show that tidal instability can be
+generated by nonlinear couplings of inertia-gravity waves with the equilibrium
+tidal flow in short-period massive binaries, even against the Joule diffusion.
+In the nonlinear regime, a fossil magnetic field can be dissipated by the
+turbulent magnetic diffusion induced by the saturated tidal flows. We predict
+that the turbulent Joule diffusion of fossil fields would occur in a few
+million years for several short-period massive binaries. Therefore, turbulent
+tidal flows could explain the observed dearth of some short-period magnetic
+binaries.",1902.10599v2
+2020-04-08,High-order crystal field and rare-earth magnetism in RECo5 intermetallics,"Crystal-field (CF) effects on the rare-earth (RE) ions in ferrimagnetic
+intermetallics NdCo$_5$ and TbCo$_5$ are evaluated using an ab initio density
+functional + dynamical mean-field theory approach in conjunction with a
+quasi-atomic approximation for on-site electronic correlations on the localized
+4$f$ shell. The study reveals an important role of the high-order sectoral
+harmonic component of the CF in the magnetism of RECo$_5$ intermetallics. An
+unexpectedly large value is computed in the both systems for the corresponding
+crystal-field parameter (CFP) $A_6^6 \langle r^6 \rangle$, far beyond what one
+would expect from only electrostatic contributions. It allows solving the
+enigma of the non-saturation of zero-temperature Nd magnetic moments in
+NdCo$_5$ along its easy axis in the Co exchange field. This unsaturated state
+had been previously found out from magnetization distribution probed by
+polarised neutron elastic scattering but had so far remained theoretically
+unexplained. The easy plane magnetic anisotropy of Nd in NdCo$_5$ is strongly
+enhanced by the large value of $A_6^6\langle r^6 \rangle$. Counter-intuitively,
+the polar dependence of anisotropy energy within the easy plane remains rather
+small. The easy plane magnetic anisotropy of Nd is reinforced up to high
+temperatures, which is explained through $J$-mixing effects. The calculated ab
+initio anisotropy constants of NdCo$_5$ and their temperature dependence are in
+quantitative agreement with experiment. Unlike NdCo$_5$, the $A_6^6 \langle r^6
+\rangle$ CFP has negligible effects on the Tb magnetism in TbCo$_5$ suggesting
+that its impact on the RE magnetism is ion-specific across the RECo$_5$ series.
+The origin of its large value is the hybridization of RE and Co states in a
+hexagonally coordinated local environment of the RE ion in RECo$_5$
+intermetallics.",2004.03945v1
+2020-04-25,"Effects of Oxidation of Top and Bottom Interfaces on the Electric, Magnetic, and Spin-Orbit Torque Properties of Pt/Co/AlOx Trilayers","Oxidation strongly influences the properties of magnetic layers employed in
+spintronic devices. We study the effect of oxidation on the structural,
+magnetic, and electrical properties as well as current-induced spin-orbit
+torques (SOTs) in Pt/Co/AlOx, Pt/CoOx/Co/AlOx, and PtOx/Co/AlOx layers. We show
+how the saturation magnetization, perpendicular magnetic anisotropy, anomalous
+Hall resistance, and SOT are systematically affected by the degree of oxidation
+of both the Pt/Co and Co/Al interfaces. Oxidation of the Co/Al interface
+results in a 21% and 42% variation of the dampinglike and fieldlike SOT
+efficiencies, which peak at 0.14 and 0.07, respectively. The insertion of a
+paramagnetic CoOx layer between Pt and Co maintains a very strong perpendicular
+magnetic anisotropy and improves the dampinglike and fieldlike SOT
+efficiencies, up to 0.26 and 0.20, respectively. In contrast with recent
+reports, we do not find that the oxidation of Pt leads to a significant
+enhancement of the torques. Rather, we find that oxygen migrates from Pt to the
+Co and Al layers, leading to a time-dependent oxidation profile and an
+effective spin Hall conductivity that decreases with increasing oxygen
+concentration. Finally, we study current-induced switching in Pt/Co/AlOx with
+different degrees of oxidation and find a linear relationship between the
+critical switching current and the effective magnetic anisotropy controlled by
+the oxidation of Al. These results highlight the importance of interfaces and
+oxidation effects on the SOT and magnetotransport properties of heavy
+metal/ferromagnet/oxide trilayers and provide information on how to improve the
+SOT efficiency and magnetization-switching characteristics of these systems.",2004.12115v1
+2021-05-13,Near-Room-Temperature Ferromagnetic Behavior of Single-Atom-Thick 2D Iron in Nanolaminated Ternary MAX Phases,"Two dimensional (2D) ferromagnetic materials have attracted much attention in
+the fields of condensed matter physics and materials science, but their
+synthesis is still a challenge given their limitations on structural stability
+and susceptibility to oxidization. MAX phases nanolaminated ternary carbides or
+nitrides possess a unique crystal structure in which single-atom-thick A
+sublayers are interleaved by two dimensional MX slabs, providing nanostructured
+templates for designing 2D ferromagnetic materials if the non-magnetic A
+sublayers can be substituted replaced by magnetic elements. Here, we report
+three new ternary magnetic MAX phases (Ta2FeC, Ti2FeN and Nb2FeC) with A
+sublayers of single-atom-thick 2D iron through an isomorphous replacement
+reaction of MAX precursors (Ta2AlC, Ti2AlN and Nb2AlC) with a Lewis acid salts
+(FeCl2). All these MAX phases exhibit ferromagnetic (FM) behavior. The Curie
+temperature (Tc) of Ta2FeC and Nb2FeC MAX phase are 281 K and 291 K,
+respectively, i.e. close to room temperature. The saturation magnetization of
+these ternary magnetic MAX phases is almost two orders of magnitude higher than
+that of V2(Sn,Fe)C MAX phase whose A-site is partial substituted by Fe.
+Theoretical calculations on magnetic orderings of spin moments of Fe atoms in
+these nanolaminated magnetic MAX phases reveal that the magnetism can be mainly
+ascribed to intralayer exchange interaction of the 2D Fe atomic layers. Owning
+to the richness in composition of MAX phases, there is a large compositional
+space for constructing functional single-atom-thick 2D layers in materials
+using these nanolaminated templates.",2105.06139v1
+2021-09-02,Phenomenological theory of magnetic 90$^{\circ}$ helical state,"We explore a phenomenological phase diagram for the magnetic helical state
+with 90$^{\circ}$ turn angle between neighboring spins in the external magnetic
+field. Such state is formed by the Eu spin layers in the superconducting iron
+arsenide RbEuFe$_{4}$As$_{4}$. The peculiarity of this spin configuration is
+that it is not realized in the standard Heisenberg model with bilinear exchange
+interactions. A minimum model allowing for such a state requires the
+biquadratic nearest-neighbor interaction term. In addition, in tetragonal
+materials the 90$^\circ$ helix state may be stabilized by the in-plane
+four-fold anisotropy term, which also fixes helix orientation with respect to
+the crystal lattice. Such a system has a very rich behavior in the external
+magnetic field. The magnetic field induces the metamagnetic transition to the
+double-periodic state with the moment angles ($\alpha$, $\alpha$, $-\alpha$,
+$-\alpha$) with respect to the field for the four subsequent spins. The
+transition field to this state from the deformed helix is determined by the
+strength of biquadratic interaction. The transition is second order for small
+biquadratic coupling and becomes first order when this coupling exceeds the
+critical value. On the other hand, the aligned state at high magnetic field
+becomes unstable with respect to formation of incommensurate fan state which
+transforms into the double-periodic state with decreasing magnetic field. The
+range of this incommensurate state near the saturation field is proportional to
+square of the biquadratic coupling. In addition, when the magnetic field is
+applied along one of four the equilibrium moment directions, the deformed helix
+state experience the first-order rotation transition at the field determined by
+the four-fold anisotropy. rotation transition at the field determined by the
+four-fold anisotropy.",2109.01096v2
+2022-02-24,Methodology for estimating the magnetic Prandtl number and application to solar surface small-scale dynamo simulations,"Context. A crucial step in the numerical investigation of small-scale dynamos
+in the solar atmosphere consists of an accurate determination of the magnetic
+Prandtl number, Prm, stemming from radiative magneto-hydrodynamic (MHD)
+simulations. Aims. The aims are to provide a reliable methodology for
+estimating the effective Reynolds and magnetic Reynolds numbers, Re and Rem,
+and their ratio Prm=Rem/Re (the magnetic Prandlt number), that characterise MHD
+simulations and to categorise small-scale dynamo simulations in terms of these
+dimensionless parameters. Methods. The methodology proposed for computing Re
+and Rem is based on the method of projection on proper elements and it relies
+on a post-processing step carried out using higher order accurate numerical
+operators than the ones in the simulation code. A number of radiative MHD
+simulations with different effective viscosities and plasma resistivities were
+carried out with the CO5BOLD code, and the resulting growth rate of the
+magnetic energy and saturated magnetic field strengths were characterised in
+terms of Re and Rem. Results. Overall, the proposed methodology provides a
+solid estimate of the dissipation coefficients affecting the momentum and
+induction equations of MHD simulation codes, and consequently also a reliable
+evaluation of the magnetic Prandtl number characterising the numerical results.
+Additionally, it is found that small-scale dynamos are active and can amplify a
+small seed magnetic field up to significant values in CO5BOLD simulations with
+a grid spacing smaller than h=12 km, even at Prm=0.65. However, it is also
+evident that it is difficult to categorise dynamo simulations in terms of Prm
+alone, because it is not only important to estimate the amplitude of the
+dissipation coefficients, but also at which scales energy dissipation takes
+place.",2202.12115v2
+2022-08-12,Weyl nodal ring states and Landau quantization with very large magnetoresistance in square-net magnet EuGa$_4$,"Magnetic topological semimetals (TSMs) allow for an effective control of the
+topological electronic states by tuning the spin configuration, and therefore
+are promising materials for next-generation electronic and spintronic
+applications. Of magnetic TSMs, Weyl nodal-line (NL) semimetals likely have the
+most tunability, and yet they are the least experimentally studied so far due
+to the scarcity of material candidates. Here, using a combination of
+angle-resolved photoemission spectroscopy and quantum oscillation measurements,
+together with density functional theory calculations, we identify the
+square-net compound EuGa4 as a new magnetic Weyl nodal ring (NR) semimetal, in
+which the line nodes form closed rings in the vicinity of the Fermi level.
+Remarkably, the Weyl NR states show distinct Landau quantization with clear
+spin splitting upon application of a magnetic field. At 2 K in a field of 14 T,
+the transverse magnetoresistance of EuGa4 exceeds 200,000%, which is more than
+two orders of magnitude larger than that of other known magnetic TSMs. High
+field magnetoresistance measurements indicate no saturation up to 40 T. Our
+theoretical model indicates that the nonsaturating MR naturally arises as a
+consequence of the Weyl NR state. Our work thus point to the realization of
+Weyl NR states in square-net magnetic materials, and opens new avenues for the
+design of magnetic TSMs with very large magnetoresistance.",2208.06407v2
+2022-11-18,Global simulations of Tayler instability in stellar interiors: a long-time multi-stage evolution of the magnetic field,"Magnetic fields have been observed in massive Ap/Bp stars and presumably are
+also present in the radiative zone of solar-like stars. Yet, to date there is
+no clear understanding of the dynamics of the magnetic field in stably
+stratified layers. A purely toroidal magnetic field configuration is known to
+be unstable, developing mainly non-axisymmetric modes. Rotation and a small
+poloidal field component may lead to a stable configuration. Here we perform
+global MHD simulations with the EULAG-MHD code to explore the evolution of a
+toroidal magnetic field located in a layer whose stratification resembles the
+solar tachocline. Our numerical experiments allow us to explore the initial
+unstable phase as well as the long-term evolution of the magnetic field. During
+the first Alfven cycles, we observe the development of the Tayler instability
+with the prominent longitudinal wavenumber, $m=1$. Rotation decreases the
+growth rate of the instability, and eventually suppresses it. However, after a
+stable phase, sudden energy surges lead to the development of higher order
+modes even for fast rotation. These modes extract energy from the initial
+toroidal field. Nevertheless, our results show that sufficiently fast rotation
+leads to a lower saturation energy of the unstable modes, resulting in a
+magnetic topology with only a small fraction of poloidal field which remains
+steady for several hundreds of Alfven travel times. At this stage, the system
+becomes turbulent and the field is prone to turbulent diffusion. The final
+toroidal-poloidal configuration of the magnetic field may represent an
+important aspect of the field generation and evolution in stably-stratified
+layers.",2211.10536v2
+2023-11-01,"Misaligned magnetized accretion flows onto spinning black holes: magneto-spin alignment, outflow power and intermittent jets","Magnetic fields regulate black hole (BH) accretion, governing both the inflow
+and outflow dynamics. When a BH becomes saturated with large-scale vertical
+magnetic flux, it enters a magnetically-arrested disk (MAD) state. The
+dynamically-important BH magnetic flux powers highly efficient relativistic
+outflows (or jets) and sporadically erupts from the BH into the disk midplane.
+Here we explore the evolution of MADs when the BH and gas angular momentum are
+misaligned, which is expected to be more common. Using numerical simulations,
+we find that jets from rapidly spinning, prograde BHs force the inner accretion
+flow into alignment with the BH spin via the magneto-spin alignment mechanism
+for disks initially misaligned at $\mathcal{T}\lesssim 60^{\circ}$. Extremely
+misaligned MAD disks, on the other hand, exhibit intermittent jets that blow
+out parts of the disk to $\approx 100$ gravitational radii before collapsing,
+leaving behind hot cavities and magnetized filaments. These intermittent jet
+mechanism forms a mini-feedback cycle and could explain some cases of X-ray and
+radio quasi-periodic eruptions observed in dim AGN. Further, we find that (i)
+for BHs with low power jets, the BH spin and initial disk tilt angle changes
+the amount of horizon magnetic flux, and (ii) geometrically-thick, misaligned
+accretion flows do not undergo sustained Lense-Thirring (LT) precession.
+Thereby, we suggest that low-luminosity accreting BHs ($\dot{M}\ll 10^{-3}
+\dot{M}_{\rm Edd}$) are not likely to exhibit quasi-periodic oscillations in
+lightcurves due to LT precession, in agreement with observations of BH X-ray
+binaries and AGN in the low-hard/quiescent state. Instead, we suggest that
+magnetic flux eruptions can mimic precession-like motion, such as observed in
+the M87 jet, by driving large-scale surface waves in the jets.",2311.00432v1
+1995-12-06,Solitonic Strings and BPS Saturated Dyonic Black Holes,"We consider a six-dimensional solitonic string solution described by a
+conformal chiral null model with non-trivial $N=4$ superconformal transverse
+part. It can be interpreted as a five-dimensional dyonic solitonic string wound
+around a compact fifth dimension. The conformal model is regular with the
+short-distance (`throat') region equivalent to a WZW theory. At distances
+larger than the compactification scale the solitonic string reduces to a dyonic
+static spherically-symmetric black hole of toroidally compactified heterotic
+string. The new four-dimensional solution is parameterised by five charges,
+saturates the Bogomol'nyi bound and has nontrivial dilaton-axion field and
+moduli fields of two-torus. When acted by combined T- and S-duality
+transformations it serves as a generating solution for all the static
+spherically-symmetric BPS-saturated configurations of the low-energy heterotic
+string theory compactified on six-torus. Solutions with regular horizons have
+the global space-time structure of extreme Reissner-Nordstrom black holes with
+the non-zero thermodynamic entropy which depends only on conserved (quantised)
+charge vectors. The independence of the thermodynamic entropy on moduli and
+axion-dilaton couplings strongly suggests that it should have a microscopic
+interpretation as counting degeneracy of underlying string configurations. This
+interpretation is supported by arguments based on the corresponding
+six-dimensional conformal field theory. The expression for the level of the WZW
+theory describing the throat region implies a renormalisation of the string
+tension by a product of magnetic charges, thus relating the entropy and the
+number of oscillations of the solitonic string in compact directions.",9512031v3
+2015-06-23,On the dependence of the X-ray continuum variations with luminosity in accreting X-ray pulsars,"Using RXTE/ASM archival data, we investigate the behaviour of the spectral
+hardness ratio as a function of X-ray luminosity in a sample of six transient
+X-ray pulsars (EXO 2030+375, GX 304-1, 4U 0115+63, V 0332+63, A 0535+26 and MXB
+0656-072). In all sources we find that the spectral hardness ratio defined as
+$F_{5-12\mathrm{keV}}/ F_{1.33-3\mathrm{keV}}$ increases with the ASM flux
+(1.33--12 keV) at low luminosities and then saturates or even slightly
+decreases above some critical X-ray luminosity falling into the range
+$\sim(3-7)\times10^{37}$~erg~s$^{-1}$. Two-dimensional structure of accretion
+columns in the radiation-diffusion limit is calculated for two possible
+geometries (filled and hollow cylinder) for mass accretion rates $\dot M$
+ranging from $10^{17}$ to 1.2$\times 10^{18}$~g s$^{-1}$. The observed spectral
+behaviour in the transient X-ray pulsars with increasing $\dot M$ can be
+reproduced by a Compton saturated sidewall emission from optically thick
+magnetized accretion columns with taking into account the emission reflected
+from the neutron star atmosphere. At $\dot M$ above some critical value $\dot
+M_{cr}\sim (6-8)\times 10^{17}$~g~s$^{-1}$, the hight of the column becomes
+such that the contribution of the reflected component to the total emission
+starts decreasing, which leads to the saturation and even slight decrease of
+the spectral hardness. Hollow-cylinder columns have a smaller height than the
+filled-cylinder ones, and the contribution of the reflected component in the
+total emission does not virtually change with $\dot M$ (and hence the hardness
+of the continuum monotonically increases) up to higher mass accretion rates
+than $\dot M_{cr}$ for the filled columns.",1506.07082v1
+2021-04-01,Improved Accuracy and Precision In Simultaneous Myocardial T1 and T2 mapping with Multi-Parametric SASHA (mSASHA),"Purpose: To develop and validate a multi-parametric SAturation-recovery
+single-SHot Acquisition (mSASHA) cardiac T1 and T2 mapping technique with high
+accuracy and precision in a single breath-hold.
+  Methods: The mSASHA acquisition consists of 9 images in an 11 heartbeat
+breath-hold -- the first without preparation, 6 images with saturation recovery
+preparation, and 2 images with both saturation recovery and T2-preparation. T1
+and T2 values were calculated using a 3-parameter model. mSASHA was validated
+in simulations and phantoms on a Siemens 3T Prisma scanner with comparison to a
+joint T1-T2 technique with a 4-parameter model. mSASHA values were compared to
+reference MOLLI, SASHA and T2p-bSSFP sequences in 10 healthy volunteers.
+  Results: mSASHA had high accuracy compared to reference spin-echo
+measurements, with an average of -0.7+/-0.4% T1 error and -1.3+/-1.3% T2 error.
+mSASHA coefficient of variation (CoV) in phantoms for T1 was lower than MOLLI
+(0.7+/-0.1% vs 0.9+/-0.2%, p<0.01) and similar to reference T2p-bSSFP for T2
+(1.4+/-0.6% vs 1.5+/-0.5%, p>0.05). In simulations, 3-parameter mSASHA fitting
+had higher precision than 4-parameter joint T1-T2 fitting for both T1 and T2.
+In-vivo myocardial mSASHA T1 was similar to conventional SASHA (1523+/-18 ms vs
+1520+/-18 ms, p>0.05) with similar CoV to both MOLLI and SASHA (3.3+/-0.6% vs
+3.1+/-0.6% and 3.3+/-0.5% respectively, p>0.05 for both). Myocardial mSASHA T2
+values were 37.1+/-1.1 ms with similar precision to T2p-bSSFP (6.7+/-1.7% vs
+6.0+/-1.6%, p>0.05).
+  Conclusion: mSASHA provides high accuracy cardiac T1 and T2 quantification in
+a single breath-hold, with similar precision to reference MOLLI and linear
+T2p-bSSFP reference techniques.",2104.00729v1
+2023-05-29,Entanglement entropy analysis of dyonic black holes using doubly holographic theory,"We investigate the entanglement between the eternal black hole and Hawking
+radiation. For this purpose, we utilize the doubly holographic theories and
+study the entanglement entropy of the radiation to find the Page curve
+consistent with the unitarity principle. Doubly holographic theories introduce
+two types of boundaries in the AdS bulk, namely the usual AdS boundary and the
+Planck brane. In such a setup, we calculate the entanglement entropy by
+examining two extremal surfaces: the Hartman-Maldacena (HM) surface and the
+island surface. The latter surface emerges when the island appears on the
+Planck brane. In this paper, we provide a detailed analysis of dyonic black
+holes with regard to the Page curve in the context of the doubly holographic
+setup. To begin with, we ascertain that the pertinent topological terms must be
+included in the Planck brane to describe the systems at finite density and
+magnetic field. Furthermore, we also develop a general numerical method to
+compute the time-dependent HM surface and achieve excellent agreement between
+the numerical results and analytical expressions. Utilizing numerical
+methodology, we find that the entanglement entropy of dyonic black holes
+exhibits unitary evolution over time, wherein it grows in early time and
+reaches saturation after the Page time. The initial growth can be explained by
+the HM surface, while the saturation is attributed to the island surface. In
+addition, using the holographic entanglement density, we also show that, for
+the first time, the saturated value of the entanglement entropy is twice the
+Bekenstein-Hawking entropy with the tensionless brane in double holography.",2305.18122v3
+2023-11-07,Effect of the neutral beam injector operational regime on the Alfven eigenmode saturation phase in DIII-D plasma,"The aim of this study is to analyze the effect of the neutral beam injector
+(NBI) operation regime on the saturation phase of the Alfven Eigenmodes (AEs)
+in DIII-D plasma. The analysis is done using the linear and nonlinear versions
+of the gyro-fluid code FAR3d. A set of parametric analyses are performed
+modifying the nonlinear simulation EP \b{eta} (NBI injection power), EP energy
+(NBI voltage) and the radial location of the EP density profile gradient (NBI
+radial deposition). The analysis indicates a transition from the soft (local
+plasma relaxation) to the hard MHD (global plasma relaxation) limit if the
+simulation EP \b{eta} >= 0.02, leading to bursting MHD activity caused by
+radial AEs overlapping. MHD bursts cause an enhancement of the EP transport
+showing ballistic-like features as avalanche-like events. Simulations in the
+soft MHD limit show an increment of the EP density gradient as the EP \b{eta}
+increases. On the other hand, there is a gradient upper limit in the hard MHD
+limit, consistent with the critical-gradient behavior. AEs induce shear flows
+and zonal current leading to the deformation of the flux surfaces and the
+safety factor profile, respectively, particularly strong for the simulation in
+the hard MHD limit. Simulations in the hard MHD regime show a decrease of the
+AE frequency in the saturation phase; this is caused by the destabilization of
+a transitional mode between a 9/3-10/3 TAE and a 9/3 RSAE that may explain the
+AE frequency down-sweeping observed in some DIII-D discharges. Reducing the EP
+energy in the nonlinear simulations leads to a weakening of the plasma
+perturbation. On the other hand, increasing the EP energy causes the opposite
+effect. Nonlinear simulations of off-axis NBI profiles indicate a lower plasma
+perturbation as the EP density gradient is located further away from the
+magnetic axis.",2311.03729v1
+2024-02-27,Ultraviolet and Chromospheric activity and Habitability of M stars,"M-type stars are crucial for stellar activity studies since they cover two
+types of magnetic dynamos and particularly intriguing for habitability studies
+due to their abundance and long lifespans during the main-sequence stage. In
+this paper, we used the LAMOST DR9 catalog and the GALEX UV archive data to
+investigate the chromospheric and UV activities of M-type stars. All the
+chromospheric and UV activity indices clearly show the saturated and
+unsaturated regimes and the well-known activity-rotation relation, consistent
+with previous studies. Both the FUV and NUV activity indices exhibit a
+single-peaked distribution, while the {\rm H$\alpha$} and \rm {Ca
+\scriptsize{\uppercase\expandafter{\romannumeral2}} \normalsize H$\&$K} indices
+show a distinct double-peaked distribution. The gap between these peaks
+suggests a rapid transition from a saturated population to an unsaturated one.
+The smoothly varying distributions of different subtypes suggest a
+rotation-dependent dynamo for both early-type (partly convective) to late-type
+(fully convective) M stars. We identified a group of stars with high UV
+activity above the saturation regime (log$R^{\prime}_{\rm NUV} > -2.5$) but low
+chromospheric activity, and the underlying reason is unknown. By calculating
+the continuously habitable zone and the UV habitable zone for each star, we
+found about 70\% stars in the total sample and 40\% stars within 100 pc are
+located in the overlapping region of these two habitable zones, indicating a
+number of M stars are potentially habitable. Finally, we examined the
+possibility of UV activity studies of M stars using the China Space Station
+Telescope.",2402.17384v2
+2001-07-31,A Weakly Nonlinear Alfvenic Pulse in a Transversely Inhomogeneous Medium,"The interaction of a weakly nonlinear Alfv\'enic pulse with an Alfv\'en speed
+inhomogeneity in the direction perpendicular to the magnetic field is
+investigated. Identically to the phase mixing experienced by a harmonic
+Alfv\'en wave, sharp transverse gradients are generated in the pulse by the
+inhomogeneity. In the initial stage of the evolution of an initially plane
+Alfv\'enic pulse, the transverse gradients efficiently generate transversely
+propagating fast magnetoacoustic waves. However, high resolution full MHD
+numerical simulations of the developed stage of the pulse evolution show that
+the generation saturates due to destructive wave interference. It is shown that
+the weakly non-linear description of the generated fast magnetoacoustic wave is
+well described by the driven wave equation proposed in Nakariakov, Roberts &
+Murawski (1997), and a simple numerical code (2D MacCromack), which solves it
+with minimal CPU resources produces identical results to those obtained from
+the full MHD code ({\it Lare2d}, Arber et al. 2001). A parametric study of the
+phenomenon is undertaken, showing that, contrary to one's expectations, steeper
+inhomogenities of the Alfv\'en speed do not produce higher saturation levels of
+the fast wave generation. There is a certain optimal gradient of the
+inhomogeneity that ensures the maximal efficiency of the fast wave generation.",0107580v1
+2002-08-06,The Magnetorotational Instability in Core Collapse Supernova Explosions,"We investigate the action of the magnetorotational instability (MRI) in the
+context of iron-core collapse. Exponential growth of the field on the rotation
+time scale by the MRI will dominate the linear growth process of field line
+""wrapping"" with the same characteristic time. We examine a variety of initial
+rotation states, with solid body rotation or a gradient in rotational velocity,
+that correspond to models in the literature. A relatively modest value of the
+initial rotation, a period of ~ 10 s, will give a very rapidly rotating PNS and
+hence strong differential rotation with respect to the infalling matter. We
+assume conservation of angular momentum on spherical shells. Results are
+discussed for two examples of saturation fields, a fiducial field that
+corresponds to Alfven velocity = rotational velocity and a field that
+corresponds to the maximum growing mode of the MRI. Modest initial rotation
+velocities of the iron core result in sub-Keplerian rotation and a
+sub-equipartition magnetic field that nevertheless produce substantial MHD
+luminosity and hoop stresses: saturation fields of order 10^{15} - 10^{16} G
+develop within 300 msec after bounce with an associated MHD luminosity of about
+10^{52} erg/s. Bi-polar flows driven by this MHD power can affect or even cause
+the explosions associated with core-collapse supernovae.",0208128v2
+2004-01-15,High Levels of Circularly Polarized Emission from the Radio Jet in NGC 1275 (3C 84),"We present multi-frequency, high resolution VLBA circular polarization images
+of the radio source 3C 84 in the center of NGC 1275. Our images reveal a
+complex distribution of circular polarization in the inner parsec of the radio
+jet, with local levels exceeding 3% polarization, the highest yet detected with
+VLBI techniques. The circular polarization changes sign along the jet, making
+3C 84 also the first radio jet to show both signs of circular polarization
+simultaneously. The spectrum and changing sign of the circular polarization
+indicate that it is unlikely to be purely intrinsic to the emitted synchrotron
+radiation. The Faraday conversion process makes a significant and perhaps
+dominant contribution to the circular polarization, and the observed spectrum
+suggests the conversion process is near saturation. The sign change in the
+circular polarization along the jet may result from this saturation or may be
+due to a change in magnetic field order after an apparent bend in the jet. From
+the small spatial scales probed here, ~ 0.15 pc, and the comparably high levels
+of circular polarization inferred for the intra-day variable source PKS
+1519-273, we suggest a connection between small spatial scales and efficient
+production of circular polarization.",0401319v1
+2005-02-16,GEOTAIL observation of the SGR1806-20 Giant Flare: The first 600 ms,"On December 27, 2004, plasma particle detectors on the GEOTAIL spacecraft
+detected an extremely strong signal of hard X-ray photons from the giant flare
+of SGR1806-20, a magnetar candidate. While practically all gamma-ray detectors
+on any satellites were saturated during the first ~500 ms interval after the
+onset, one of the particle detectors on GEOTAIL was not saturated and provided
+unique measurements of the hard X-ray intensity and the profile for the first
+600 ms interval with 5.48 ms time resolution. After ~50 ms from the initial
+rapid onset, the peak photon flux (integrated above ~50 keV) reached the order
+of 10^7 photons sec^{-1} cm^{-2}. Assuming a blackbody spectrum with kT=175
+keV, we estimate the peak energy flux to be 21 erg sec^{-1} cm^{-2} and the
+fluence (for 0-600 ms) to be 2.4 erg cm^{-2}. The implied energy release
+comparable to the magnetic energy stored in a magnetar (~10^{47} erg) suggests
+an extremely efficient energy release mechanism.",0502315v3
+2004-03-28,Fully polarized states and decoherence,"The aim of this review is to show how ``ferromagnetic'' states, that is,
+states having a fully polarization, can produce intrinsic decoherence by
+unitary evolution. This effect can give an understanding of recent experiments
+on mesoscopic devices as quantum point contacts showing the 0.7 conductance
+anomaly and the wide number of data about saturation of dephasing time observed
+at very low temperatures, as a fully polarized two dimensional electron gas.
+But similar effects can be seen in different area of physics as for example the
+Dicke model describing the interaction of two-level systems with a radiation
+mode. In this case one can show that decoherence is intrinsic and remove a
+Schr\""odinger cat state leaving a single coherent state, collapsing the wave
+function in the thermodynamic limit. So, saturation of dephasing time at low
+temperatures in mesoscopic devices can be understood by a fully polarized two
+dimensional electron gas that, by an exchange model, can be reduced to a
+generalized form of the Dicke Hamiltonian and where the quasiparticles are spin
+excitations interacting with magnons. In this way, one can see that several
+experiments on nanowires and quantum dots can be satisfactorily explained. The
+existence of intrinsic decoherence in the thermodynamic limit could have deep
+implications in fundamental problems like quantum measurement and
+irreversibility. Recent experiments with cavities with a large number of
+photons and with nuclear magnetic resonance in organic molecular crystals give
+a first strong support to this view.",0403678v1
+2005-05-19,"Impact of Zn substitution on phase formation and superconductivity of Bi1.6Pb0.4 Sr2Ca2Cu3-xZnxO10 with x = 0.0, 0.015, 0.03, 0.06, 0.09 and 0.12","Samples of series Bi1.6Pb0.4Sr2Ca2Cu3-xZnxO10 with x = 0.0, 0.015, 0.03,
+0.06, 0.09 and 0.12 are synthesized by solid-state reaction route. All the
+samples crystallize in tetragonal structure with majority (> 90%) of Bi-2223
+(Bi2Sr2Ca2Cu3O10) phase (c-lattice parameter ~ 36 A0). The proportion of
+Bi-2223 phase decreases slightly with an increase in x. The lattice parameters
+a and c of main phase (Bi-2223) do not change significantly with increasing x.
+Superconducting critical transition temperature (Tc) decreases with x as
+evidenced by both resistivity [(T)] and AC magnetic susceptibility [(T)]
+measurements. Interestingly the decrement of Tc is not monotonic and the same
+saturates at around 96 K for x > 0.06. In fact Tc decreases fast (~10K/at%) for
+x = 0.015 and 0.03 samples and later nearly saturates for higher x values.
+Present results of Zn doping in Bi-2223 system are compared with Zn doped other
+HTSC (High temperature superconducting) systems, namely the RE-123 (REBa2Cu3O7)
+and La-214 ((La,Sr)2CuO4).",0505461v1
+1995-10-15,General class of BPS saturated dyonic black holes as exact superstring solutions,"We show that a four-parameter generating solution for a general class of
+four-dimensional, spherically-symmetric, static, dyonic BPS saturated solutions
+of leading-order effective equations of toroidally compactified heterotic or
+type II superstring theory are exact string solutions. The corresponding
+ten-dimensional background defines a conformal sigma-model which is a
+particular case of a `chiral null model' with curved `transverse' part. The
+exact conformal invariance is a consequence of the chiral null structure of the
+`electric' part of the model and the N=4 world-sheet supersymmetry of its
+transverse `magnetic' part. The sigma-model action has a remarkable covariance
+under both target space and the electromagnetic $S$-duality transformations,
+and it illustrates the relation between string-string duality in six dimensions
+and $S$-duality in four dimensions. In general, there exists a large class of
+exact six-dimensional superstring solutions described by chiral null models
+with four-dimensional transverse parts represented by N=4 supersymmetric
+sigma-models with metrics conformal to hyper-Kahler ones.",9510097v4
+1998-11-22,Domain Walls in Supersymmetric Yang-Mills Theories,"We study BPS saturated domain walls in the supersymmetric SU(2) gauge theory.
+For a theory with a very light adjoint scalar (mass <~ Lambda/400) we use the
+perturbed N=2 Seiberg-Witten theory to calculate the actual field configuration
+of the domain wall. The wall has a sandwich-like five-layer structure of three
+distinct phases -- electric confinement, Coulomb and oblique confinement --
+separated by two separate transition regions. For larger scalar masses, the
+three-phase structure disappears and the Seiberg-Witten theory becomes
+inadequate because of two major problems: First, the higher-derivative
+interactions between the light fields become relevant and second, both the
+magnetic monopole condensate and the dyon condensate show up in the same region
+of space, a phenomenon indescribable in terms of a local field theory.
+Nevertheless, we argue that the BPS saturated domain wall continues to exist in
+this regime and give a qualitative description of the scalar and gaugino
+condensates. Finally, we discuss the domain walls in MQCD and translate the BPS
+conditions into coupled non-linear differential equations.",9811195v1
+2002-12-23,Domain Walls and Flux Tubes in N=2 SQCD: D-Brane Prototypes,"This paper could have been entitled ""D branes and strings from flesh and
+blood."" We study field theoretic prototypes of D branes/strings. To this end we
+consider (2+1)-dimensional domain walls in (3+1)-dimensional N=2 SQCD with
+SU(2) gauge group and two quark flavors in the fundamental representation. This
+theory is perturbed by a small mass term of the adjoint matter which, in the
+leading order in the mass parameter, does not break N=2 supersymmetry, and
+reduces to a (generalized) Fayet-Iliopoulos term in the effective low-energy
+N=2 SQED. We find 1/2 BPS-saturated domain wall solution interpolating between
+two quark vacua at weak coupling, and show that this domain wall localizes a
+U(1) gauge field. To make contact with the brane/string picture we consider the
+Abrikosov-Nielsen-Olesen magnetic flux tube in one of two quark vacua and
+demonstrate that it can end on the domain wall. We find an explicit 1/4
+BPS-saturated solution for the wall/flux tube junction. We verify that the end
+point of the flux tube on the wall plays the role of an electric charge in the
+dual (2+1)-dimensional SQED living on the wall. Flow to N=1 theory is
+discussed. Our results lead us to a conjecture regarding the notorious ""missing
+wall"" in the solution of Kaplunovsky et al.",0212293v2
+2006-06-07,Domain Lines as Fractional Strings,"We consider N=2 supersymmetric quantum electrodynamics (SQED) with 2 flavors,
+the Fayet--Iliopoulos parameter, and a mass term $\beta$ which breaks the
+extended supersymmetry down to N=1. The bulk theory has two vacua; at $\beta=0$
+the BPS-saturated domain wall interpolating between them has a moduli space
+parameterized by a U(1) phase $\sigma$ which can be promoted to a scalar field
+in the effective low-energy theory on the wall world-volume. At small
+nonvanishing $\beta$ this field gets a sine-Gordon potential. As a result, only
+two discrete degenerate BPS domain walls survive. We find an explicit solitonic
+solution for domain lines -- string-like objects living on the surface of the
+domain wall which separate wall I from wall II. The domain line is seen as a
+BPS kink in the world-volume effective theory. We expect that the wall with the
+domain line on it saturates both the $\{1,0\}$ and the $\{{1/2},{1/2}\}$b
+central charges of the bulk theory. The domain line carries the magnetic flux
+which is exactly 1/2 of the flux carried by the flux tube living in the bulk on
+each side of the wall. Thus, the domain lines on the wall confine charges
+living on the wall, resembling Polyakov's three-dimensional confinement.",0606060v2
+2008-02-09,Spin dynamics near the critical doping in weakly-superconducting underdoped YBa2Cu3O6.35 (Tc=18K),"Using neutron scattering we have determined the magnetic structure and
+fluctuations in the YBa2Cu3O6.35 superconductor (Tc=18 K). The long-range
+ordered collinear spins of the insulating antiferromagnet are replaced by a
+commensurate central mode arising from slow, isotropically polarized,
+short-range spin correlations. The inelastic spectrum up to 30 meV is broad in
+wave vector and commensurate. In contrast to the the resonance peak of higher
+Tc superconductors, the spins exhibit a single overdamped spectrum whose rate
+of relaxation decreases on cooling and saturates at 5 meV below 50 K. As the
+relaxation rate saturates the quasi-static spin correlations grow and become
+resolution limited in energy. The spin susceptibility at high temperatures
+illustrates that the dominant energy scale is set by the temperature. At low
+temperatures, the scale length is geometric and not linked by velocity to
+dynamic widths. There is no observable suppression of the spin fluctuations or
+central mode upon the onset of superconductivity. The spins respond not to
+coherent charge pairs but to hole doping allowing coexistence of glassy short
+range spin order with superconductivity. Since the physics of the weakly
+superconducting system YBCO6.35 must connect continuously with that in more
+strongly superconducting YBCO6.5, we find that neither incommensurate
+stripe-like spin modulations nor a well-defined neutron spin resonance are
+essential for the onset with doping of pairing in a high temperature cuprate
+superconductor.",0802.1252v1
+2009-07-02,The chromospheric emission of solar-type stars in the young open clusters IC 2391 and IC 2602,"In this paper we present chromospheric emission levels of the solar-type
+stars in the young open clusters IC 2391 and IC 2602. High resolution
+spectroscopic data were obtained for over 50 F, G, and K stars from these
+clusters over several observing campaigns using the University College London
+Echelle Spectrograph on the 3.9-m Anglo-Australian Telescope. Unlike older
+clusters, the majority (28/52) of the solar-type stars in the two clusters are
+rapid-rotators (vsini > 20 km/s) with five of the stars being classified as
+ultra-rapid rotators (vsini > 100 km/s). The emission levels in the Calcium
+infrared triplet lines were then used as a measure of the chromospheric
+activity of the stars. When plotted against Rossby number (NR) the star's
+chromospheric emission levels show a plateau in the emission for Log(NR) < -1.1
+indicating chromospheric saturation similar to the coronal saturation seen in
+previously observed X-ray emission from the same stars. However, unlike the
+coronal emission, the chromospheric emission of the stars show little evidence
+of a reduction in emission (i.e. supersaturation) for the ultra-rapid rotators
+in the clusters. Thus we believe that coronal supersaturation is not the result
+of an overall decrease in magnetic dynamo efficiency for ultra-rapid rotators.",0907.0286v1
+2010-01-28,A mean-field approach to the propagation of field patterns in stratified magneto rotational turbulence,"Local shearing box simulations of stratified magneto rotational turbulence
+invariably exhibit cyclic field patterns which propagate away from the disc
+midplane. A common explanation for this is magnetic buoyancy. The recent
+analysis by Shi et al. however shows that the flow is buoyantly stable below
+one disc scale height H, necessitating an alternative explanation in this
+region. We here conduct and analyse direct numerical simulations to explain the
+observed behaviour by means of a mean-field description. Apart from the mean
+radial and azimuthal field, we monitor the small-scale current helicity, which
+we propose as a key indicator for saturation. Reconstructing the horizontally
+averaged field, we demonstrate that the problem can be reduced to a
+one-dimensional induction equation. By means of the so-called test field
+method, we then determine the underlying closure parameters. Our analysis shows
+that, apart from a possible direct MRI dynamo, two distinct indirect dynamo
+mechanisms operate in the disc. This resolves the issue of the ""wrong"" sign of
+the MRI dynamo effect. Finally, we use the obtained closure parameters to run a
+dynamically quenched dynamo model. This model approximately recovers the
+observed field patterns in the mean fields. Moreover, the model reproduces the
+prevailing parity and the distinct phase pattern in the small-scale current
+helicity. The latter property might open a potential route to understand the
+saturation of MRI induced turbulence.",1001.5250v1
+2011-05-05,"Synthesis, magnetization and magneto transport study of RECoPO (RE = La, Nd & Sm)","We report the electrical, magneto transport and specific heat of the layered
+polycrystalline RECoPO (RE = La, Nd and Sm) samples. These compounds are
+iso-structural to recently discovered superconductor LaFeAs(O/F). Bulk
+polycrystalline samples are synthesized by solid state reaction route in an
+evacuated sealed quartz tube. All these compounds are crystallized in a
+tetragonal structure with space group P4/nmm. The Cobalt in these compounds is
+in itinerant state with its paramagnetic moment above 1.4\muB and the same
+orders ferromagnetically (FM) with saturation moment of around 0.20\muB below
+say 80K. Though, LaCoPO shows single paramagnetic (PM) to ferromagnetic (FM)
+transition near 35K, the NdCoPO and SmCoPO exhibit successive PM-FM-AFM
+transitions. Both FM and AFM transition temperatures vary with applied field.
+Although the itinerant ferromagnetism occurs with small saturation moment,
+typical anti-ferromagnetic (AFM) transitions (TN1, TN2) are observed at 69K and
+14K for Nd and 57K and 45K for Sm. This FM-AFM transition of Co spins in NdCoPO
+and SmCoPO is both field and temperature dependent. The Magneto-transport of
+NdCoPO and SmCoPO distinctly follows their successive PM-FM-AFM transitions. It
+is clear that Sm/Nd (4f) interacts with the Co (3d) in first time synthesized
+Sm/NdCoPO.",1105.0971v2
+2012-08-19,$β$ NMR study of Isolated $^8$Li in the enhanced paramagnet Platinum,"We report {\beta} detected nuclear magnetic resonance ({\beta}NMR)
+measurements of 8Li+ implanted into high purity Pt. The frequency of the 8Li
+{\beta}NMR resonance and the spin-lattice relaxation rates 1/T1 were measured
+at temperatures ranging from 3 to 300 K. Remarkably, both the spin-lattice
+relaxation rate and the Knight shift K depend linearly on temperature T
+although the bulk susceptibility does not. K is found to scale with the
+Curie-Weiss dependence of the Pt susceptibility extrapolated to low
+temperatures. This is attributed to a defect response of the enhanced
+paramagnetism of Pt, i.e. the presence of the interstitial Li+ locally relieves
+the tendency for the Curie-Weiss susceptibility to saturate at low T . We
+propose that the low temperature saturation in \c{hi} of Pt may be related to
+an interband coupling between the s and d bands that is disrupted locally by
+the presence of the Li+.",1208.3873v1
+2013-05-08,The Fate of Planetesimals in Turbulent Disks with Dead Zones. I. The Turbulent Stirring Recipe,"Turbulence in protoplanetary disks affects planet formation in many ways.
+While small dust particles are mainly affected by the aerodynamical coupling
+with turbulent gas velocity fields, planetesimals and larger bodies are more
+affected by gravitational interaction with gas density fluctuations. For the
+latter process, a number of numerical simulations have been performed in recent
+years, but a fully parameter-independent understanding has not been yet
+established. In this study, we present simple scaling relations for the
+planetesimal stirring rate in turbulence driven by magnetorotational
+instability (MRI), taking into account the stabilization of MRI due to Ohmic
+resistivity. We begin with order-of-magnitude estimates of the
+turbulence-induced gravitational force acting on solid bodies and associated
+diffusion coefficients for their orbital elements. We then test the predicted
+scaling relations using the results of recent Ohmic-resistive MHD simulations
+by Gressel et al. We find that these relations successfully explain the
+simulation results if we properly fix order-of-unity uncertainties within the
+estimates. We also update the saturation predictor for the density fluctuation
+amplitude in MRI-driven turbulence originally proposed by Okuzumi & Hirose.
+Combination of the scaling relations and saturation predictor allows to know
+how the turbulent stirring rate of planetesimals depends on disk parameters
+such as the gas column density, distance from the central star, vertical
+resistivity distribution, and net vertical magnetic flux. In Paper II, we apply
+our recipe to planetesimal accretion to discuss its viability in turbulent
+disks.",1305.1889v1
+2014-02-20,Synchronization and phase ordering in globally coupled chaotic maps,"We investigate the processes of synchronization and phase ordering in a
+system of globally coupled maps possessing bistable, chaotic local dynamics.
+The stability boundaries of the synchronized states are determined on the space
+of parameters of the system. The collective properties of the system are
+characterized by means of the persistence probability of equivalent spin
+variables that define two phases, and by a magnetization-like order parameter
+that measures the phase-ordering behavior. As a consequence of the global
+interaction, the persistence probability saturates for all values of the
+coupling parameter, in contrast to the transition observed in the temporal
+behavior of the persistence in coupled maps on regular lattices. A
+discontinuous transition from a non-ordered state to a collective phase-ordered
+state takes place at a critical value of the coupling. On an interval of the
+coupling parameter, we find three distinct realizations of the phase-ordered
+state, which can be discerned by the corresponding values of the saturation
+persistence. Thus, this statistical quantity can provide information about the
+transient behaviors that lead to the different phase configurations in the
+system. The appearance of disordered and phase-ordered states in the globally
+coupled system can be understood by calculating histograms and the time
+evolution of local map variables associated to the these collective states.",1402.4870v1
+2014-07-17,The Role of the Magnetorotational Instability in the Sun,"We calculate growth rates for nonaxisymmetric instabilities including the
+magnetorotational instability (MRI) throughout the Sun. We first derive a
+dispersion relation for nonaxisymmetric instability including the effects of
+shear, convective buoyancy, and three diffusivities (thermal conductivity,
+resistivity, and viscosity). We then use a solar model evolved with the stellar
+evolution code MESA and angular velocity profiles determined by Global
+Oscillations Network Group (GONG) helioseismology to determine the unstable
+modes present at each location in the Sun and the associated growth rates. The
+overall instability has unstable modes throughout the convection zone and also
+slightly below it at middle and high latitudes. It contains three classes of
+modes: large-scale hydrodynamic convective modes, large-scale hydrodynamic
+shear modes, and small-scale magnetohydrodynamic (MHD) shear modes, which may
+be properly called MRI modes. While large-scale convective modes are the most
+rapidly growing modes in most of the convective zone, MRI modes are important
+in both stably stratified and convectively unstable locations near the
+tachocline at colatitudes theta less than 53 degrees. Nonaxisymmetric MRI modes
+grow faster than the corresponding axisymmetric modes; for some poloidal
+magnetic fields, the nonaxisymmetric MRI growth rates are similar to the
+angular rotation frequency Omega, while axisymmetric modes are stabilized. We
+briefly discuss the saturation of the field produced by MRI modes, finding that
+the implied field at the base of the convective zone in the Sun is comparable
+to that derived based on dynamos active in the tachocline and that the
+saturation of field resulting from the MRI may be of importance even in the
+upper convection zone.",1407.4654v1
+2014-08-22,Composition-spread Growth and the Robust Topological Surface State of Kondo insulator SmB6 Thin Films,"Topological insulators are a class of materials with insulating bulk but
+protected conducting surfaces due to the combination of spin-orbit interactions
+and time-reversal symmetry. The surface states are topologically non-trivial
+and robust against non-magnetic backscattering, leading to interesting physics
+and potential quantum computing applications1, 2. Recently there has been a
+fast growing interest in samarium hexboride (SmB6), a Kondo insulator predicted
+to be the first example of a correlated topological insulator3, 4. Here we
+fabricated smooth thin films of nanocrystalline SmB6 films. Their transport
+behavior indeed shows that SmB6 is a bulk insulator with topological surface
+states. Upon decreasing the temperature, the resistivity \r{ho} of Sm0.14B0.86
+(SmB6) films display significant increase below 50 K due to hybridization gap
+formation, and it shows a saturation behavior below 10 K. The saturated
+resistance of our textured films is similar to that of the single crystals,
+suggesting that this conduction is from the surface and robust against grain
+boundary scatterings. Point contact spectroscopy (PCS) of the film using a
+superconducting tip displays both a Kondo Fano resonance and Andreev
+reflection, suggesting the existence of both an insulating Kondo lattice and
+metallic surface states.",1408.5413v1
+2015-01-16,A Multi-wavelength study of the M dwarf binary YY Geminorum,"We review the results of the 1988 multi-wavelength campaign on the late-type
+eclipsing binary YY Geminorum. Observations include: broad-band optical and
+near infra-red photometry, simultaneous optical and ultraviolet (IUE)
+spectroscopy, X-ray (Ginga) and radio (VLA) data. From models fitted to the
+optical light curves, fundamental physical parameters have been determined
+together with evidence for transient maculations (spots) located near
+quadrature longitudes and intermediate latitudes.
+  Eclipses were observed at optical, ultraviolet and radio wavelengths.
+Significant drops in 6cm radio emission near the phases of both primary and
+secondary eclipse indicate relatively compact radio emitting volumes that may
+lie between the binary components. IUE observations during secondary eclipse
+are indicative of a uniform chromosphere saturated with MgII plage-type
+emission and an extended volume of Ly$\alpha$ emission.
+  Profile fitting of high-dispersion H alpha spectra confirms the chromospheric
+saturation and indicates significant H$\alpha$ opacity to heights of a few
+percent of the photospheric radius. There is evidence for an enhanced H alpha
+emission region visible near phase 0.25-0.35 which may be associated with a
+large spot on the primary and with two small optical flares which were also
+observed at other wavelengths: one in microwave radiation and the other in
+X-rays. For both flares, L_X/L_opt is consistent with energy release in closed
+magnetic structures.",1501.03930v1
+2016-05-17,"Berry phase, entanglement entropy, and algebraic properties of ground states of BCS and BEC superfluids","By using Bogoliubov transformations to construct the ground states of
+fermionic Bardeen-Cooper-Schrieffer (BCS) superfluids and weakly-interacting
+Bose gases supporting Bose Einstein Condensation (BEC), their algebraic
+structures and implications can be analyzed in detail. Both ground states are
+generalized squeezed coherent states saturating a generalized Heisenberg
+uncertainty relation, and they acquire quantized Berry phases when the
+corresponding systems are transported along a closed path in their parameter
+spaces. While the Berry phase of the BCS ground state depends on the total
+particle number, the Berry phase of the BEC ground state depends only on the
+particles outside the BEC. The Berry phases are associated with magnetic
+monopoles in the parameter spaces and we found that the Dirac quantization
+condition is satisfied. Moreover, both ground states are entangled states of
+the fermion or boson quanta and we found the entanglement entropy quantifying
+the internal correlations. A fixed particle-number approach of fermionic
+superfluids does not saturate the generalized uncertainty relation, exhibits
+internal entanglement, and gives corresponding Berry phase. In addition, the
+algebraic structures of the ground states can be classified by the $q$-deformed
+Hopf algebra, $\bigoplus_{\mathbf{k}}h_{q_{\mathbf{k}}}(1)$ for bosons and
+$q$-deformed Hopf superalgebra $\bigoplus_{\mathbf{k}}h_{q_{\mathbf{k}}}(1|1)$
+for fermions, respectively.",1605.05213v3
+2016-09-07,Ferromagnetic layer thickness dependence of the Dzyaloshinskii-Moriya interaction and spin-orbit torques in Pt\Co\AlOx,"We report the thickness dependence of Dzyaloshinskii-Moriya interaction (DMI)
+and spin-orbit torques (SOTs) in Pt\Co(t)\AlOx, studied by current-induced
+domain wall (DW) motion and second-harmonic experiments. From the DW motion
+study, a monotonous decay of the effective DMI strength with an increasing Co
+thickness is observed, in agreement with a DMI originating at the Pt\Co
+interface. The study of the ferromagnetic thickness dependence of spin-orbit
+torques reveals a more complex behavior. The effective SOT-field driving the DW
+motion is found to initially increase and then saturate with an increasing
+ferromagnetic thickness, while the effective SOT-fields acting on a saturated
+magnetic state exhibit a non-monotonic behavior with increasing Co-thickness.
+The observed thickness dependence suggests the spin-Hall effect in Pt as the
+main origin of the SOTs, with the measured SOT amplitudes resulting from the
+interplay between the varying thickness and the transverse spin diffusion
+length of the Co layer.",1609.02078v1
+2017-02-13,The Evaporation and Survival of Cluster Galaxies' Coronae Part I: The Effectiveness of Isotropic Thermal Conduction Including Saturation,"We simulate the evolution of cluster galaxies' hot interstellar medium (ISM)
+gas due to ram pressure and thermal conduction in the intracluster medium
+(ICM). At the density and temperature of the ICM, the mean free paths of ICM
+electrons are comparable to the sizes of galaxies, therefore electrons can
+efficiently transport heat due to thermal conduction from the hot ICM to the
+cooler ISM. Galaxies consisting of dark matter halos and hot gas coronae are
+embedded in an ICM-like `wind tunnel' in our simulations. In this paper, we
+assume that thermal conduction is isotropic and include the effects of
+saturation. We find that as heat is transferred from the ICM to the ISM, the
+cooler denser ISM expands and evaporates. This process is significantly faster
+than gas loss due to ram pressure stripping; for our standard model galaxy the
+evaporation time is $160$ Myr while the ram pressure stripping timescale is
+$2.5$ Gyr. Thermal conduction also suppresses the formation of shear
+instabilities, and there are no stripped ISM tails since the ISM evaporates
+before tails can form. Observations of long-lived X-ray emitting coronae and
+ram pressure stripped X-ray tails in galaxies in group and cluster environments
+therefore require that thermal conduction is suppressed or offset by some
+additional physical process. The most likely process is anisotropic thermal
+conduction due to magnetic fields in the ISM and ICM, which we simulate and
+study in the next paper in this series.",1702.03971v2
+2017-04-02,Extremely large non-saturating magnetoresistance and ultrahigh mobility due to topological surface states in metallic Bi2Te3 topological insulator,"Weak antilocalization (WAL) effects in Bi2Te3 single crystals have been
+investigated at high and low bulk charge carrier concentrations. At low charge
+carrier density the WAL curves scale with the normal component of the magnetic
+field, demonstrating the dominance of topological surface states in
+magnetoconductivity. At high charge carrier density the WAL curves scale with
+neither the applied field nor its normal component, implying a mixture of bulk
+and surface conduction. WAL due to topological surface states shows no
+dependence on the nature (electrons or holes) of the bulk charge carriers. The
+observations of an extremely large, non-saturating magnetoresistance, and
+ultrahigh mobility in the samples with lower carrier density further support
+the presence of surface states. The physical parameters characterizing the WAL
+effects are calculated using the Hikami-Larkin-Nagaoka formula. At high charge
+carrier concentrations, there is a greater number of conduction channels and a
+decrease in the phase coherence length compared to low charge carrier
+concentrations. The extremely large magnetoresistance and high mobility of
+topological insulators have great technological value and can be exploited in
+magneto-electric sensors and memory devices.",1704.00339v2
+2017-06-05,Dynamics of an $n=1$ explosive instability and its role in high-$β$ disruptions,"Some low-$n$ kink-ballooning modes not far from marginal stability are shown
+to exhibit a bifurcation between two very distinct nonlinear paths that depends
+sensitively on the background transport levels and linear perturbation
+amplitudes. The particular instability studied in this work is an $n=1$ mode
+dominated by an $m/n=2/1$ component. It is driven by a large pressure gradient
+in weak magnetic shear and can appear in various high-$\beta,$ hybrid/advanced
+scenarios. Here it is investigated in reversed shear equilibria where the
+region around the safety-factor minimum provides favorable conditions. For a
+certain range of parameters, a relatively benign path results in a saturated
+""long-lived mode"" (LLM) that causes little confinement degradation. At the
+other extreme, the quadrupole geometry of the $2/1$ perturbed pressure field
+evolves into a ballooning finger that subsequently transitions from exponential
+to explosive growth. The finger eventually leads to a fast disruption with
+precursors too short for any mitigation effort. Interestingly, the saturated
+LLM state is found to be metastable, it also can be driven explosively unstable
+by finite-amplitude perturbations. Similarities to some high-$\beta$
+disruptions in reversed-shear discharges are discussed.",1706.01204v1
+2017-06-18,"Walls, Anomalies, and (De)Confinement in Quantum Anti-Ferromagnets","We consider the Abelian-Higgs model in 2+1 dimensions with instanton-monopole
+defects. This model is closely related to the phases of quantum
+anti-ferromagnets. In the presence of $\mathbb{Z}_2$ preserving monopole
+operators, there are two confining ground states in the monopole phase,
+corresponding to the Valence Bond Solid (VBS) phase of quantum magnets. We show
+that the domain-wall carries a 't Hooft anomaly in this case. The anomaly can
+be saturated by, e.g., charge-conjugation breaking on the wall or by the domain
+wall theory becoming gapless (a gapless model that saturates the anomaly is
+$SU(2)_1$ WZW). Either way the fundamental scalar particles (i.e. spinons)
+which are confined in the bulk are deconfined on the domain-wall. This
+$\mathbb{Z}_2$ phase can be realized either with spin-1/2 on a rectangular
+lattice, or spin-1 on a square lattice. In both cases the domain wall contains
+spin-1/2 particles (which are absent in the bulk). We discuss the possible
+relation to recent lattice simulations of domain walls in VBS. We further
+generalize the discussion to Abrikosov-Nielsen-Olsen (ANO) vortices in a dual
+superconductor of the Abelian-Higgs model in 3+1 dimensions, and to the
+easy-plane limit of anti-ferromagnets. In the latter case the wall can undergo
+a variant of the BKT transition (consistent with the anomalies) while the bulk
+is still gapped. The same is true for the easy-axis limit of anti-ferromagnets.
+We also touch upon some analogies to Yang-Mills theory.",1706.05731v2
+2017-07-17,Electrostatic and whistler instabilities excited by an electron beam,"The electron beam-plasma system is ubiquitous in the space plasma
+environment. Here, using a Darwin particle-in-cell method, the excitation of
+electrostatic and whistler instabilities by a gyrating electron beam is studied
+in support of recent laboratory experiments. It is assumed that the total
+plasma frequency $\omega_{pe}$ is larger than the electron cyclotron frequency
+$\Omega_e$. The fast-growing electrostatic beam-mode waves saturate in a few
+plasma oscillations by slowing down and relaxing the electron beam parallel to
+the background magnetic field. Upon their saturation, the finite amplitude
+electrostatic beam-mode waves can resonate with the tail of the background
+thermal electrons and accelerate them to the beam parallel velocity. The
+slower-growing whistler waves are excited in primarily two resonance modes: (a)
+through Landau resonance due to the inverted slope of the beam electrons in the
+parallel velocity; (b) through cyclotron resonance by scattering electrons to
+both lower pitch angles and smaller energies. It is demonstrated that, for a
+field-aligned beam, the whistler instability can be suppressed by the
+electrostatic instability due to a faster energy transfer rate between beam
+electrons and the electrostatic waves. Such a competition of growth between
+whistler and electrostatic waves depends on the ratio of
+$\omega_{pe}/\Omega_e$. In terms of wave propagation, beam-generated
+electrostatic waves are confined to the beam region whereas beam-generated
+whistler waves transport energy away from the beam.",1707.05346v1
+2017-11-13,KOI-256's Magnetic Activity under the Influence of the White Dwarf,"We present the findings about chromospheric activity nature of KOI-256
+obtained from the Kepler Mission data. Firstly, it was found that there are
+some sinusoidal variations out-of-eclipses due to cool spot activity. The
+sinusoidal variations modelled by the SPOTMODEL program indicate that the
+active component has two different active regions. Their longitudinal variation
+revealed that one of them has a migration period of 3.95 years, while the other
+has a migration period of 8.37 years. Secondly, 225 flares were detected from
+the short cadence data in total. The parameters, such as increase (Tr) and
+decay (Td) times, total flare time (Tt), equivalent durations (P), were
+calculated for each flare. The distribution of equivalent durations versus
+total flare times in logarithmic scale is modelled to find flare activity
+level. The Plateau value known as the saturation level of the active component
+was calculated to be 2.3121+-0.0964 s, and the Half-life value, which is
+required flare total time to reach the saturation, was computed to be 2233.6 s.
+In addition, the frequency of N1, which is the number of flares per an hour in
+the system, was found to be 0.05087 1/h, while the flare frequency N2 that the
+flare-equivalent duration emitting per an hour was found to be 0.00051.
+Contrary to the spot activity, it has been found that the flares are in tends
+to appear at specific phases due to the white dwarf component.",1711.04737v1
+2017-11-20,Vortices and the saturation of the vertical shear instability in protoplanetary disks,"If sufficiently irradiated by its central star, a protoplanetary disks falls
+into an equilibrium state exhibiting vertical shear. This state may be subject
+to a hydrodynamical instability, the `vertical shear instability' (VSI), whose
+breakdown into turbulence transports a moderate amount of angular momentum
+while also facilitating planet formation, possibly via the production of
+small-scale vortices. In this paper, we show that VSI modes (a) exhibit
+arbitrary spatial profiles and (b) remain nonlinear solutions to the
+incompressible local equations, no matter their amplitude. The modes are
+themselves subject to parasitic Kelvin-Helmholtz instability, though the disk
+rotation significantly impedes the parasites and permits the VSI to attain
+large amplitudes (fluid velocities < 10% the sound speed). This `delay' in
+saturation probably explains the prominence of the VSI linear modes in global
+simulations. More generally, the parasites may set the amplitude of VSI
+turbulence in strongly irradiated disks. They are also important in breaking
+the axisymmetry of the flow, via the unavoidable formation of vortices. The
+vortices, however, are not aligned with the orbital plane and thus express a
+pronounced $z$-dependence. We also briefly demonstrate that the vertical shear
+has little effect on the magnetorotational instability, whereas magnetic fields
+easily quench the VSI, a potential issue in the ionised surface regions of the
+disk and also at larger radii.",1711.07436v1
+2018-04-24,Fermi Surface and Carriers Compensation of pyrite-type PtBi$_{2}$ Revealed by Quantum Oscillations,"Large non-saturating magnetoresistance has been observed in various materials
+and electron-hole compensation has been regarded as one of the main mechanisms.
+Here we present a detailed study of the angle-dependent Shubnikov -de Haas
+effect on large magnetoresistance material pyrite-type PtBi$_{2}$, which allows
+us to experimentally reconstruct its Fermi-surface structure and extract the
+physical properties of each pocket. We find its Fermi surface contains four
+types of pockets in the Brillouin zone: three ellipsoid-like hole pockets
+$\alpha$ with C$_4$ symmetry located on the edges (M points), one intricate
+electron pocket $\beta$ merged from four ellipsoids along [111] located on the
+corners (R points), two smooth and cambered octahedrons $\gamma$ (electron) and
+$\delta$ (hole) on the center ($\Gamma$ point). The deduced carrier densities
+of electrons and holes from the volume of pockets prove carrier compensation.
+This compensation at low temperatures is also supported by fitting the field
+dependence of Hall and magnetoresistance at different temperatures. We conclude
+that the compensation is the main mechanism for the large non-saturating
+magnetoresistance in pyrite-type PtBi$_{2}$. We found the hole pockets {\alpha}
+may contribute major mobility because of their light masses and anisotropy to
+relatively avoid large-angle scattering at low temperature. This may be a
+common feature of semimetals with large magnetoresistance. The found
+sub-quadratic magnetoresistance in high field is probably due to
+field-dependent mobilities, another feature of semimetals under high magnetic
+fields.",1804.08795v2
+2018-10-09,Scrambling dynamics and many-body chaos in a random dipolar spin model,"Is there a quantum many-body system that scrambles information as fast as a
+black hole? The Sachev-Ye-Kitaev model can saturate the conjectured bound for
+chaos, but it requires random all-to-all couplings of Majorana fermions that
+are hard to realize in experiments. Here we examine a quantum spin model of
+randomly oriented dipoles where the spin exchange is governed by dipole-dipole
+interactions. The model is inspired by recent experiments on dipolar spin
+systems of magnetic atoms, dipolar molecules, and nitrogen-vacancy centers. We
+map out the phase diagram of this model by computing the energy level
+statistics, spectral form factor, and out-of-time-order correlation (OTOC)
+functions. We find a broad regime of many-body chaos where the energy levels
+obey Wigner-Dyson statistics and the OTOC shows distinctive behaviors at
+different times: Its early-time dynamics is characterized by an exponential
+growth, while the approach to its saturated value at late times obeys a power
+law. The temperature scaling of the Lyapunov exponent $\lambda_L$ shows that
+while it is well below the conjectured bound $2\pi T$ at high temperatures,
+$\lambda_L$ approaches the bound at low temperatures and for large number of
+spins.",1810.03815v2
+2018-10-12,Nonlinear dynamics of Shear Alfvén fluctuations in Divertor Tokamak Test facility plasmas,"Following the analysis on linear spectra of shear Alfv\'en fluctuations
+excited by energetic particles (EPs) in the Divertor Tokamak Test (DTT)
+facility plasmas [T. Wang et al., Phys. Plasmas 25, 062509 (2018)], in this
+work, nonlinear dynamics of the corresponding mode saturation and the
+fluctuation induced EP transport is studied by hybrid
+magnetohydrodynamic-gyrokinetic simulations. For the reversed shear Alfv\'en
+eigenmode driven by magnetically trapped EP precession resonance in the central
+core region of DTT plasmas, the saturation is mainly due to radial decoupling
+of resonant trapped EPs. Consistent with the wave-EP resonance structure, EP
+transport occurs in a similar scale to the mode width. On the other hand,
+passing EP transport is analyzed in detail for toroidal Alfv\'en eigenmode in
+the outer core region, with mode drive from both passing and trapped EPs. It is
+shown that passing EPs experience only weak redistributions in the weakly
+unstable case; and the transport extends to meso-scale diffusion in the
+strongly unstable case, due to orbit stochasticity induced by resonance
+overlap. Here, weakly/strongly unstable regime is determined by Chirikov
+condition for resonance overlap. This work then further illuminates rich and
+diverse nonlinear EP dynamics related to burning plasma studies, and the
+capability of DTT to address these key physics.",1810.05327v1
+2019-01-08,Quadratic to linear magnetoresistance tuning in TmB4,"The change of a material's electrical resistance (R) in response to an
+external magnetic field (B) provides subtle information for the
+characterization of its electronic properties and has found applications in
+sensor and storage related technologies. In good metals, Boltzmann's theory
+predicts a quadratic growth in magnetoresistance (MR) at low B, and saturation
+at high fields. On the other hand, a number of nonmagnetic materials with weak
+electronic correlation and low carrier concentration for metallicity, such as
+inhomogeneous conductors, semimetals, narrow gap semiconductors and topological
+insulators, two-dimensional electron gas (2DEG) show positive, non-saturating
+linear magnetoresistance (LMR). However, observation of LMR in single crystals
+of a good metal is rare. Here we present low-temperature, angle dependent
+magnetotransport in single crystals of the antiferromagnetic metal, TmB4. We
+observe large, positive and anisotropic MR(B), which can be tuned from
+quadratic to linear by changing the direction of the applied field. In view of
+the fact that isotropic, single crystalline metals with large Fermi surface
+(FS) are not expected to exhibit LMR, we attribute our observations to the
+anisotropic FS topology of TmB4. Furthermore, the linear MR is found to be
+temperature-independent, suggestive of quantum mechanical origin.",1901.02165v1
+2019-03-10,Magnons at low excitations: Observation of incoherent coupling to a bath of two-level-systems,"Collective magnetic excitation modes, magnons, can be coherently coupled to
+microwave photons in the single excitation limit. This allows for access to
+quantum properties of magnons and opens up a range of applications in quantum
+information processing, with the intrinsic magnon linewidth representing the
+coherence time of a quantum resonator. Our measurement system consists of a
+yttrium iron garnet (YIG) sphere and a three-dimensional (3D) microwave cavity
+at temperatures and excitation powers typical for superconducting quantum
+circuit experiments. We perform spectroscopic measurements to determine the
+limiting factor of magnon coherence at these experimental conditions. Using the
+input-output formalism, we extract the magnon linewidth $\kappa_\mathrm{m}$. We
+attribute the limitations of the coherence time at lowest temperatures and
+excitation powers to incoherent losses into a bath of near-resonance two-level
+systems (TLSs), a generic loss mechanism known from superconducting circuits
+under these experimental conditions. We find that the TLSs saturate when
+increasing the excitation power from quantum excitation to multi-photon
+excitation and their contribution to the linewidth vanishes. At higher
+temperatures, the TLSs saturate thermally and the magnon linewidth decreases as
+well.",1903.03981v3
+2019-05-14,Direct evidence for charge compensation induced large magnetoresistance in thin WTe2,"Since the discovery of extremely large non-saturating magnetoresistance (MR)
+in WTe2, much effort has been devoted to understanding the underlying
+mechanism, which is still under debate. Here, we explicitly identify the
+dominant physical origin of the large non-saturating MR through in-situ tuning
+of the magneto-transport properties in thin WTe2 film. With an electrostatic
+doping approach, we observed a non-monotonic gate dependence of the MR. The MR
+reaches a maximum (10600%) in thin WTe2 film at certain gate voltage where
+electron and hole concentrations are balanced, indicating that the charge
+compensation is the dominant mechanism of the observed large MR. Besides, we
+show that the temperature dependent magnetoresistance exhibits similar tendency
+with the carrier mobility when the charge compensation is retained, revealing
+that distinct scattering mechanisms may be at play for the temperature
+dependence of magneto-transport properties. Our work would be helpful for
+understanding mechanism of the large MR in other nonmagnetic materials and
+offers an avenue for achieving large MR in the non-magnetic materials with
+electron-hole pockets.",1905.05364v1
+2020-01-06,Highly efficient spin orbit torque in Pt/Co/Ir multilayers with antiferromagnetic interlayer exchange coupling,"We have studied the spin orbit torque (SOT) in Pt/Co/Ir multilayers with 3
+repeats of the unit structure. As the system exhibits oscillatory interlayer
+exchange coupling (IEC) with varying Ir layer thickness, we compare the SOT of
+films when the Co layers are coupled ferromagnetically and
+antiferromagnetically. SOT is evaluated using current induced shift of the
+anomalous Hall resistance hysteresis loops. A relatively thick Pt layer,
+serving as a seed layer to the multilayer, is used to generate spin current via
+the spin Hall effect. In the absence of antiferromagnetic coupling, the SOT is
+constant against the applied current density and the corresponding spin torque
+efficiency (i.e. the effective spin Hall angle) is $\sim$0.09, in agreement
+with previous reports. In contrast, for films with antiferromagnetic coupling,
+the SOT increases with the applied current density and eventually saturates.
+The SOT at saturation is a factor of $\sim$15 larger than that without the
+antiferromagnetic coupling. The spin torque efficiency is $\sim$5 times larger
+if we assume the net total magnetization is reduced by a factor of 3 due to the
+antiferromagnetic coupling. Model calculations based on the Landau Lifshitz
+Gilbert equation show that the presence of antiferromagnetic coupling can
+increase the SOT but the degree of enhancement is limited, in this case, to a
+factor of 1.2-1.4. We thus consider there are other sources of SOT, possibly at
+the interfaces, which may account for the highly efficient SOT in the
+uncompensated synthetic anti-ferromagnet (SAF) multilayers.",2001.01454v1
+2020-06-21,The role of parametric instabilities in turbulence generation and proton heating: Hybrid simulations of parallel propagating Alfvén waves,"Large amplitude Alfv\'en waves tend to be unstable to parametric
+instabilities which result in a decay process of the initial wave into
+different daughter waves depending upon the amplitude of the fluctuations and
+the plasma beta. The propagation angle with respect to the mean magnetic field
+of the daughter waves plays an important role in determining the type of decay.
+In this paper, we revisit this problem by means of multi-dimensional hybrid
+simulations. In particular, we study the decay and the subsequent nonlinear
+evolution of large-amplitude Alfv\'en waves by investigating the saturation
+mechanism of the instability and its final nonlinear state reached for
+different wave amplitudes and plasma beta conditions. As opposed to
+one-dimensional simulations where the Decay instability is suppressed for
+increasing plasma beta values, we find that the decay process in
+multi-dimensions persists at large values of the plasma beta via the
+filamentation/magnetosonic decay instabilities. In general, the decay process
+acts as a trigger both to develop a perpendicular turbulent cascade and to
+enhance mean field-aligned wave-particle interactions. We find indeed that the
+saturated state is characterized by a turbulent plasma displaying a
+field-aligned beam at the Alfv\'en speed and increased temperatures that we
+ascribe to the Landau resonance and pitch angle scattering in phase space.",2006.11839v2
+2020-08-24,Joint Design of RF and gradient waveforms via auto-differentiation for 3D tailored excitation in MRI,"This paper proposes a new method for joint design of radiofrequency (RF) and
+gradient waveforms in Magnetic Resonance Imaging (MRI), and applies it to the
+design of 3D spatially tailored saturation and inversion pulses. The joint
+design of both waveforms is characterized by the ODE Bloch equations, to which
+there is no known direct solution. Existing approaches therefore typically rely
+on simplified problem formulations based on, e.g., the small-tip approximation
+or constraining the gradient waveforms to particular shapes, and often apply
+only to specific objective functions for a narrow set of design goals (e.g.,
+ignoring hardware constraints). This paper develops and exploits an
+auto-differentiable Bloch simulator to directly compute Jacobians of the
+(Bloch-simulated) excitation pattern with respect to RF and gradient waveforms.
+This approach is compatible with \emph{arbitrary} sub-differentiable loss
+functions, and optimizes the RF and gradients directly without restricting the
+waveform shapes. For computational efficiency, we derive and implement explicit
+Bloch simulator Jacobians (approximately halving computation time and memory
+usage). To enforce hardware limits (peak RF, gradient, and slew rate), we use a
+change of variables that makes the 3D pulse design problem effectively
+unconstrained; we then optimize the resulting problem directly using the
+proposed auto-differentiation framework. We demonstrate our approach with two
+kinds of 3D excitation pulses that cannot be easily designed with conventional
+approaches: Outer-volume saturation (90{\deg} flip angle), and inner-volume
+inversion.",2008.10594v3
+2021-04-03,MR-Contrast-Aware Image-to-Image Translations with Generative Adversarial Networks,"Purpose
+  A Magnetic Resonance Imaging (MRI) exam typically consists of several
+sequences that yield different image contrasts. Each sequence is parameterized
+through multiple acquisition parameters that influence image contrast,
+signal-to-noise ratio, acquisition time, and/or resolution. Depending on the
+clinical indication, different contrasts are required by the radiologist to
+make a diagnosis. As MR sequence acquisition is time consuming and acquired
+images may be corrupted due to motion, a method to synthesize MR images with
+adjustable contrast properties is required.
+  Methods
+  Therefore, we trained an image-to-image generative adversarial network
+conditioned on the MR acquisition parameters repetition time and echo time. Our
+approach is motivated by style transfer networks, whereas the ""style"" for an
+image is explicitly given in our case, as it is determined by the MR
+acquisition parameters our network is conditioned on.
+  Results
+  This enables us to synthesize MR images with adjustable image contrast. We
+evaluated our approach on the fastMRI dataset, a large set of publicly
+available MR knee images, and show that our method outperforms a benchmark
+pix2pix approach in the translation of non-fat-saturated MR images to
+fat-saturated images. Our approach yields a peak signal-to-noise ratio and
+structural similarity of 24.48 and 0.66, surpassing the pix2pix benchmark model
+significantly.
+  Conclusion
+  Our model is the first that enables fine-tuned contrast synthesis, which can
+be used to synthesize missing MR contrasts or as a data augmentation technique
+for AI training in MRI.",2104.01449v1
+2022-01-03,Quantum electrodynamic effects on counter-streaming instabilities in the whole \textbf{k} space,"In a recent work [Bret, EPL \textbf{135} (2021) 35001], quantum
+electrodynamic (QED) effects were evaluated for the two-stream instability. It
+pertains to the growth of perturbations with a wave vector oriented along the
+flow in a collisionless counter-streaming system. Here, the analysis is
+extended to every possible orientation of the wave vector. The previous result
+for the two-stream instability is recovered, and it is proved that even within
+the framework of a 3D analysis, this instability remains fundamentally 1D even
+when accounting for QED effects. The filamentation instability, found for wave
+vectors normal to the flow, is weakly affected by QED corrections. As in the
+classical case, its growth rate saturates at large $k_\perp$. The saturation
+value is found independent of QED corrections. Also, the smallest unstable
+$k_\perp$ is independent of QED corrections. Surprisingly, unstable modes found
+for oblique wave vectors do \emph{not} follow the same pattern. For some, QED
+corrections do reduce the growth rate. But for others, the same corrections
+increase the growth rate instead. The possibility for QED effects to play a
+role in un-magnetized systems is evaluated. Pair production resulting from
+gamma emission by particles oscillating in the exponentially growing fields, is
+not accounting for.",2201.00499v1
+2022-02-04,Measurements of Chromospheric Mg I Emission Lines of Zero-Age Main-Sequence Stars,"The chromosphere is the active atmosphere in which energetic eruption events,
+such as flares, occur. Chromospheric activity is driven by the magnetic field
+generated by stellar rotation and convection. The relationship between
+chromospheric activity and the Rossby number, the ratio of the rotational
+period to the convective turnover time, has been extensively examined for many
+types of stars, by using narrow chromospheric emission lines, such as the Ca II
+lines and the Mg II h and k lines. However, the stars with small Rossby
+numbers, i.e., stars with rapid rotations and/or long convective turnover
+times, show constant strengths of such lines against the Rossby number. In this
+study, we investigate the infrared Mg I emission lines at 8807 A of 47 zero-age
+main-sequence (ZAMS) stars in IC 2391 and IC 2602 using the archive data of the
+Anglo-Australian Telescope at the University College London Echelle
+Spectrograph. After subtracting the photospheric absorption component, the Mg I
+line is detected as an emission line for 45 ZAMS stars, whose equivalent widths
+are between 0.02 A and 0.52 A. A total of 42 ZAMS stars show the narrower Mg I
+emission lines instead of the Ca II infrared triplet emission lines, suggesting
+that they are formed at different depths. The ZAMS stars with smaller Rossby
+numbers show stronger Mg I emission lines. The Mg I emission line is not
+saturated even in ""the saturated regime of the Ca II emission lines,"" i.e.,
+Rossby number < 10^(-1.1). The Mg I emission line is considered to be a good
+indicator of chromospheric activity, particularly for active objects.",2202.02065v1
+2022-04-13,Non-local spin entanglement in a fermionic chain,"An effective two-spin density matrix (TSDM) for a pair of spin-$1/2$ degree
+of freedom, residing at a distance of $R$ in a spinful Fermi sea, can be
+obtained from the two-electron density matrix following the framework
+prescribed in Phys. Rev. A 69, 054305 (2004). We note that the single spin
+density matrix (SSDM) obtained from this TSDM for generic spin-degenerate
+systems of free fermions is always pinned to the maximally mixed state $i.e.$
+$(1/2) \ \mathbb{I}$, independent of the distance $R$ while the TSDM confirms
+to the form for the set of maximally entangled mixed state (the so called
+""X-state"") at finite $R$. The X-state reduces to a pure state (a singlet) in
+the $R\rightarrow 0$ limit while it saturates to an X-state with largest
+allowed value of von-Neumann entropy of $2 \ln2$ as $R \rightarrow \infty$
+independent of the value of chemical potential. However, once an external
+magnetic field is applied to lift the spin-degeneracy, we find that the
+von-Neumann entropy of SSDM becomes a function of the distance $R$ between the
+two spins. We also show that the von-Neumann entropy of TSDM in the
+$R\rightarrow \infty$ limit becomes a function of the chemical potential and it
+saturate to $2 \ln2$ only when the band in completely filled unlike the
+spin-degenerate case. Finally we extend our study to include spin-orbit
+coupling and show that it does effect these asymptotic results. Our findings
+are in sharp contrast with previous works which were based on continuum models
+owing to physics which stem from the lattice model.",2204.06579v1
+2022-09-16,Supergravity and p-brane Ansatz,"This project explores the $D=11$ supergravity model and the properties of its
+p-brane ansatz. The initial field content (graviton, gravitino and the
+anti-symmetric tensor field) in the action of $D=11$ supergravity is explained
+in the context of supersymmetry. The action is then decomposed to the bosonic
+sector, which is compared with the $\sigma$-model in string theory at a low
+energy limit $\alpha'\xrightarrow{}0$. The dilaton in the $D=10$ string theory
+can be realised from the dimensional reduction of $D=11$ supergravity, which
+gives the scalar contribution in the action to form the single-charge action.
+The field equation of the single-charged action is then derived. An
+$SO(D-d)\times Poincare_{d}$ ansatz is introduced to simplify the field
+equation. The solution of the field equation bifurcates into the electric
+ansatz and the magnetic ansatz. These ansatzes are called p-branes which are
+string-like objects that exist in their p-dimensional world volume embedded in
+the ambient spacetime. The BPS bounds are saturated for these p-branes, and
+upon dimensional reduction, they are similar to extremal Riessner-Nordstrom
+black holes up to the scalar. The branic motion is then derived and a special
+case of parallel brane orbit is explored. Similar to the Riessner-Nordstrom
+black hole, the circular orbit is found to require a specific angular momentum
+that increases further from the central brane. The circular orbit always exists
+for the extremal case, but the black branes that do not saturate the BPS bound
+may not have a circular orbit below a threshold angular momentum.",2209.07730v2
+2022-09-21,Starspots and Magnetism: Testing the Activity Paradigm in the Pleiades and M67,"We measure starspot filling fractions for 240 stars in the Pleiades and M67
+open star clusters using APOGEE high-resolution H-band spectra. For this work
+we developed a modified spectroscopic pipeline which solves for starspot
+filling fraction and starspot temperature contrast. We exclude binary stars,
+finding that the large majority of binaries in these clusters (80%) can be
+identified from Gaia DR3 and APOGEE criteria -- important for field star
+applications. Our data agree well with independent activity proxies, indicating
+that this technique recovers real starspot signals. In the Pleiades, filling
+fractions saturate at a mean level of 0.248$\pm$0.005 for active stars with a
+decline at slower rotation; we present fitting functions as a function of
+Rossby number. In M67, we recover low mean filling fractions of 0.030$\pm$0.008
+and 0.003$\pm$0.002 for main sequence GK stars and evolved red giants
+respectively, confirming that the technique does not produce spurious spot
+signals in inactive stars. Starspots also modify the derived spectroscopic
+effective temperatures and convective overturn timescales. Effective
+temperatures for active stars are offset from inactive ones by -109$\pm$11 K,
+in agreement with the Pecaut & Mamajek empirical scale. Starspot filling
+fractions at the level measured in active stars changes their inferred overturn
+timescale, which biases the derived threshold for saturation. Finally, we
+identify a population of stars statistically discrepant from mean
+activity-Rossby relations and present evidence that these are genuine
+departures from a Rossby scaling. Our technique is applicable to the full
+APOGEE catalog, with broad applications to stellar, galactic, and exoplanetary
+astrophysics.",2209.10549v1
+2022-11-08,Quantum metallic state at the titanium sesquioxide heterointerface,"The emergence of the quantum metallic state marked by a saturating finite
+electrical resistance in the zero-temperature limit in a variety of
+two-dimensional superconductors injects an exciting momentum to the realm of
+unconventional superconductivity. Despite much research efforts over last few
+decades, there is not yet a general consensus on the nature of this unexpected
+quantum metal. Here, we report the observation of a unique quantum metallic
+state within the hallmark of Bose-metal characterized by a saturating
+resistance and a simultaneously vanishing Hall resistance in the titanium
+sesquioxide heterointerface superconductor Ti$_2$O$_3$/GaN. Remarkably, the
+quantum bosonic metallic state tuned by a magnetic field in the vicinity of the
+two-dimensional superconductivity-metal transition persists in the normal
+phase, suggesting the existence of composite bosons, formed by electron Cooper
+pairs, even in the normal phase. Our findings indicate the existence of
+preformed electron Cooper pairs in the normal phase of heterointerface
+superconductors, and shed new light on the pairing mechanism underlying
+unconventional superconductivity.",2211.04035v2
+2023-02-08,"Data-driven Protection of Transformers, Phase Angle Regulators, and Transmission Lines in Interconnected Power Systems","This dissertation highlights the growing interest in and adoption of machine
+learning (ML) approaches for fault detection in modern power grids. Once a
+fault has occurred, it must be identified quickly and preventative steps must
+be taken to remove or insulate it. As a result, detecting, locating, and
+classifying faults early and accurately can improve safety and dependability
+while reducing downtime and hardware damage. ML-based solutions and tools to
+carry out effective data processing and analysis to aid power system operations
+and decision-making are becoming preeminent with better system condition
+awareness and data availability. Power transformers, Phase Shift Transformers
+or Phase Angle Regulators, and transmission lines are critical components in
+power systems, and ensuring their safety is a primary issue. Differential
+relays are commonly employed to protect transformers, whereas distance relays
+are utilized to protect transmission lines. Magnetizing inrush, overexcitation,
+and current transformer saturation make transformer protection a challenge.
+Furthermore, non-standard phase shift, series core saturation, low
+turn-to-turn, and turn-to-ground fault currents are non-traditional problems
+associated with Phase Angle Regulators. Faults during symmetrical power swings
+and unstable power swings may cause mal-operation of distance relays and
+unintentional and uncontrolled islanding. The distance relays also mal-operate
+for transmission lines connected to type-3 wind farms. The conventional
+protection techniques would no longer be adequate to address the above
+challenges due to limitations in handling and analyzing massive amounts of
+data, limited generalizability, incapability to model non-linear systems, etc.
+These limitations of differential and distance protection methods bring forward
+the motivation of using ML in addressing various protection challenges.",2302.03826v1
+2023-10-23,Scaling and Universality at Ramped Quench Dynamical Quantum Phase Transition,"The nonequilibrium dynamics of a periodically driven extended XY model, in
+the presence of linear time dependent magnetic filed, is investigated using the
+notion of dynamical quantum phase transitions (DQPTs). Along the similar lines
+to the equilibrium phase transition, the main purpose of this work is to search
+the fundamental concepts such as scaling and universality at the ramped quench
+DQPTs. We have shown that the critical points of the model, where the gap
+closing occurs, can be moved by tuning the driven frequency and consequently
+the presence/absence of DQPTs can be flexibly controlled by adjusting the
+driven frequency. %Taking advantage of this property, We have uncovered that,
+for a ramp across the single quantum critical point, the critical mode at which
+DQPTs occur is classified into three regions: the Kibble-Zurek (KZ) region,
+where the critical mode scales linearly with the square root of the sweep
+velocity, pre-saturated (PS) region, and the saturated (S) region where the
+critical mode makes a plateau versus the sweep velocity. While for a ramp that
+crosses two critical points, the critical modes disclose just KZ and PS
+regions. On the basis of numerical simulations, we find that the dynamical free
+energy scales linerly with time, as approaches to DQPT time, with the exponent
+$\nu=1\pm 0.01$ for all sweep velocities and driven frequencies.",2310.15101v2
+2020-04-07,"Strong, Temperature-Dependent Spin-Orbit Torques in Heavy Fermion YbAl$_3$","The use of current-generated spin-orbit torques[1] to drive magnetization
+dynamics is under investigation to enable a new generation of non-volatile,
+low-power magnetic memory. Previous research has focused on spin-orbit torques
+generated by heavy metals[2-8], interfaces with strong Rashba
+interactions[9,10] and topological insulators [11-14]. These families of
+materials can all be well-described using models with noninteracting-electron
+bandstructures. Here, we show that electronic interactions within a strongly
+correlated heavy fermion material, the Kondo lattice system YbAl$_{3}$, can
+provide a large enhancement in spin-orbit torque. The spin-torque conductivity
+increases by approximately a factor of 4 as a function of decreasing
+temperature from room temperature to the coherence temperature of YbAl$_{3}$
+($T^* \approx 37$ K), with a saturation at lower temperatures, achieving a
+maximum value greater than any heavy metal element. This temperature dependence
+mimics the increase and saturation at $T^*$ of the density of states at the
+Fermi level arising from the ytterbium 4$f$-derived heavy bands in the Kondo
+regime, as measured by angle-resolved photoemission spectroscopy[15]. We
+therefore identify the many-body Kondo resonance as the source of the large
+enhancement of spin-orbit torque in YbAl$_{3}$. Our observation reveals new
+opportunities in spin-orbit torque manipulation of magnetic memories by
+engineering quantum many-body states.",2004.03678v2
+2023-05-18,Relaxation behaviours in ferromagnetic monolayers,"In this article, we briefly review the studies on magnetic relaxation
+behaviours. The theoretical as well as experimental investigations are reported
+briefly. A major part of this article is devoted to the recent Monte Carlo
+investigations into the roles of boundary conditions, dynamics and the
+Geometrical structures on the relaxation of magnetic monolayers modelled by
+two-dimensional Ising ferromagnet. We have studied all these effects for a two
+dimensional Ising system with two types of deformations, namely preserving and
+area non-preserving.The Glauber protocol and Metropolis dynamical rules are
+employed in our simulations and we investigated the systems with both periodic
+and open boundary conditions.
+  The major findings are the exponential relaxation and the dependence of
+relaxation time ($\tau$) on the aspect ratio $R$ (length over breadth). A power
+law dependence ($\tau \sim R^{-s}$) has been observed for larger values of
+aspect ratio ($R$). The linear thermal ($T$) dependence of exponent ($s$) has
+been noticed ($s = aT + b$). The transient behaviours of the spin-flip density
+have also been studied here for both surface and bulk/core. Both the saturated
+bulk/core and saturated surface spin-flip density are observed to follow the
+logarithmic dependence $f_{d} = a + b~\log(L)$ with the system size ($L$).
+  For open boundary condition with any kind (Metropolis/Glauber) of dynamical
+rule, the faster relaxation has been observed. Similarly, Metropolis algorithm
+yields faster relaxation for any kind (open/periodic) of boundary condition. We
+appeal to the experimentalists for experimental support which may be applied in
+judicious {\it magnetic coating} of the credit cards for quicker response.",2305.10765v3
+2023-06-16,Bose-Einstein condensation of a two-magnon bound state in a spin-one triangular lattice,"Interactions of collective excitations often lead to rich emergent phenomena
+in many-particle quantum systems. In ordered magnets, the elementary
+excitations are spin waves (magnons), which obey Bose-Einstein statistics.
+Similar to the Cooper pairs in superconductors, magnons can be paired into
+bound states under attractive interactions. Even more interestingly, the Zeeman
+coupling to a magnetic field acts as a chemical potential that can tune the
+particle density through a quantum critical point (QCP), beyond which a
+``hidden order'' is predicted to exist. However, experimental confirmation of
+this QCP and the associated new state of matter remain elusive. Here we report
+direct observation of the Bose-Einstein condensation (BEC) of the two-magnon
+bound state in Na$_2$BaNi(PO$_4$)$_2$. Comprehensive thermodynamic measurements
+confirmed the existence of a two-dimensional BEC-QCP at the saturation field.
+Inelastic neutron scattering experiments were performed to accurately establish
+the magnetic exchange model. An exact solution of the model found stable
+2-magnon bound states that were further confirmed by an electron spin resonance
+(ESR) experiment, demonstrating that the QCP is due to the pair condensation
+and the phase below saturation field is the long-sought-after spin nematic (SN)
+phase.",2306.09695v1
+1999-11-10,R-Mode Oscillations in Rotating Magnetic Neutron Stars,"We show that r-mode oscillations distort the magnetic fields of neutron stars
+and that their occurrence is likely to be limited by this interaction. If the
+field is gtrsim 10^{16} (Omega/Omega_B) G, where Omega and Omega_B are the
+angular velocities of the star and at which mass shedding occurs, r-mode
+oscillations cannot occur. Much weaker fields will prevent gravitational
+radiation from exciting r-mode oscillations or damp them on a relatively short
+timescale by extracting energy from the modes faster than gravitational wave
+emission can pump energy into them. For example, a 10^{10} G poloidal magnetic
+field that threads the star's superconducting core is likely to prevent the
+ell=2 mode from being excited unless Omega exceeds 0.35 Omega_B. If Omega is
+larger than 0.35 Omega_B initially, the ell=2 mode may be excited but is likely
+to decay rapidly once Omega falls below 0.35 Omega_B, which happens in lesssim
+15^d if the saturation amplitude is gtrsim 0.1. The r-mode oscillations may
+play an important role in determining the structure of neutron star magnetic
+fields.",9911188v2
+2001-10-04,High Resolution Simulations of the Plunging Region in a Pseudo-Newtonian Potential: Dependence on Numerical Resolution and Field Topology,"New three dimensional magnetohydrodynamic simulations of accretion disk
+dynamics in a pseudo-Newtonian Paczynski-Wiita potential are presented. These
+have finer resolution in the inner disk than any previously reported. Finer
+resolution leads to increased magnetic field strength, greater accretion rate,
+and greater fluctuations in the accretion rate. One simulation begins with a
+purely poloidal magnetic field, the other with a purely toroidal field.
+Compared to the poloidal initial field simulation, a purely toroidal initial
+field takes longer to reach saturation of the magnetorotational instability and
+produces less turbulence and weaker magnetic field energies. For both initial
+field configurations, magnetic stresses continue across the marginally stable
+orbit; measured in units corresponding to the Shakura-Sunyaev alpha parameter,
+the stress grows from ~0.1 in the disk body to as much as ~10 deep in the
+plunging region. Matter passing the inner boundary of the simulation has ~10%
+greater binding energy and ~10% smaller angular momentum than it did at the
+marginally stable orbit. Both the mass accretion rate and the integrated stress
+fluctuate widely on a broad range of timescales.",0110118v1
+2003-02-05,Beyond the standard accretion disc model: coupled magnetic disc--corona solutions with a physically motivated viscosity law,"We present a systematic, analytical study of geometrically thin, optically
+thick accretion disc solutions for magnetized turbulent flows, with an
+alpha-like viscosity prescription. Under the only assumptions that (1)
+Magneto-Rotational instability (MRI) generates the turbulence that produces the
+anomalous viscosity needed for accretion to proceed, and that (2) the magnetic
+field amplified by the instability saturates due to buoyant vertical escape, we
+are able to self-consistently solve the disc structure equations including the
+fraction of power, f, that is carried off by vertical Poynting flux (and likely
+dissipated outside the optically thick disc). For low-viscosity discs, we
+obtain stable high-f solutions at low accretion rates, when gas pressure
+dominates, and unstable, low-f, radiation pressure dominated solutions at high
+accretion rates. For high viscosity discs, instead, a new thermally and
+viscously stable, radiation pressure dominated solution is found, characterized
+by f~1 and appearing only above a critical accretion rate (of the order of few
+tenths of the Eddington one). We discuss the regimes of validity of our
+assumptions, and the astrophysical relevance of our solutions. We conclude that
+our newly discovered thin disc solutions, possibly accompanied by powerful,
+magnetically dominated coronae and outflows, should be seriously considered as
+models for black holes accreting at super-Eddington rates.",0302074v1
+2004-12-06,The Neutrino Bubble Instability: A Mechanism for Generating Pulsar Kicks,"An explanation for the large random velocities of pulsars is presented. Like
+many other models, we propose that the momentum imparted to the star is given
+at birth. The ultimate source of energy is provided by the intense optically
+thick neutrino flux that is responsible for radiating the proto-neutron star's
+gravitational binding energy during the Kelvin-Helmholtz phase. The central
+feature of the kick mechanism is a radiative-driven magnetoacoustic
+instability, which we refer to as ``neutrino bubbles.'' Identical in nature to
+the photon bubble instability, the neutrino bubble instability requires the
+presence of an equilibrium radiative flux as well as a coherent steady
+background magnetic field. Over regions of large magnetic flux densities, the
+neutrino bubble instability is allowed to grow on dynamical timescales ~ 1ms,
+potentially leading to large luminosity enhancements and density fluctuations.
+Local luminosity enhancements, which preferentially occur over regions of
+strong magnetic field, lead to a net global asymmetry in the neutrino emission
+and the young neutron star is propelled in the direction opposite to these
+regions. For favorable values of magnetic field structure, size, and strength
+as well as neutrino bubble saturation amplitude, momentum kicks in excess of
+1000 km/s can be achieved. Since the neutrino-powered kick is delivered over
+the duration of the Kelvin-Helmholtz time ~ a few seconds, one expects
+spin-kick alignment from this neutrino bubble powered model.",0412144v1
+2005-04-14,Protoneutron star dynamos and pulsar magnetism,"We have investigated the turbulent mean-field dynamo action in protoneutron
+stars that are subject to convective and neutron finger instabilities during
+the early evolutionary phase. While the first one develops mostly in the inner
+regions of the star, the second one is favored in the outer regions, where the
+Rossby number is much smaller and a mean-field dynamo action is more efficient.
+By solving the mean-field induction equation we have computed the critical spin
+period below which no dynamo action is possible and found it to be $\sim 1$ s
+for a wide range of stellar models and for both axisymmetric and
+non-axisymmetric magnetic fields. Because this critical period is substantially
+longer than the characteristic spin period of very young pulsars, we expect
+that a mean-field dynamo will be effective for most protoneutron stars. The
+saturation dipole field estimated by making use of the model of ``global''
+quenching fits well the pulsar magnetic fields inferred from the spin-down
+data. Apart from the large scale magnetic field, our model predicts also a
+generation of small scale fields which are typically stronger than the poloidal
+field and can survive during the lifetime of pulsars. Extremely rapidly
+rotating protoneutron stars ($P \sim 1$ ms) may have the dipole field $\sim
+(3-6) \times 10^{14}$ G.",0504328v1
+2005-08-22,Weibel Filament Decay and Thermalization in Collisionless Shocks and Gamma-Ray Burst Afterglows,"Models for the synchrotron emission of gamma-ray burst afterglows suggest
+that the magnetic field is generated in the shock wave that forms as
+relativistic ejecta plow through the circum-burst medium. Transverse Weibel
+instability efficiently generates magnetic fields near equipartition with the
+post-shock energy density. The detailed saturated state of the instability, as
+seen in particle-in-cell simulations, consists of magnetically self-pinched
+current filaments. The filaments are parallel to the direction of propagation
+of the shock and are about a plasma skin depth in radius, forming a
+quasi--two-dimensional structure. We use a rudimentary analytical model to
+argue that the Weibel filaments are unstable to a kink-like mode, which
+destroys their quasi--two-dimensional structure. For wavelengths longer than
+than the skin depth, the instability grows at the rate equal to the speed of
+light divided by the wavelength. We calculate the transport of collisionless
+test particles in the filaments experiencing the instability and show that the
+particles diffuse in energy. This diffusion marks the beginning of
+thermalization in the shock transition layer, and causes initial magnetic field
+decay as particles escape from the filaments. We discuss the implications of
+these results for the structure of the shock and the polarization of the
+afterglow.",0508464v1
+2005-08-31,Simulations of Magnetorotational Instability in a Magnetized Couette Flow,"In preparation for an experimental study of magnetorotational instability
+(MRI) in liquid metal, we present non-ideal two-dimensional magnetohydrodynamic
+simulations of the nonlinear evolution of MRI in the experimental geometry. The
+simulations adopt initially uniform vertical magnetic fields, conducting radial
+boundaries, and periodic vertical boundary conditions. No-slip conditions are
+imposed at the cylinders. Our linear growth rates compare well with existing
+local and global linear analyses. The MRI saturates nonlinearly with horizontal
+magnetic fields comparable to the initial axial field. The rate of angular
+momentum transport increases modestly but significantly over the initial state.
+For modest fluid and magnetic Reynolds numbers Re, Rm between 100 and 1000, the
+final state is laminar reduced mean shear except near the radial boundaries,
+and with poloidal circulation scaling as the square root of resistivity, in
+partial agreement with the analysis of Knobloch and Julien. A sequence of
+simulations at Rm=20 and 100 < Re < 25,600 enables extrapolation to the
+experimental regime (Rm ~ 20, Re ~ 10^7), albeit with unrealistic boundary
+conditions. MRI should increase the experimentally measured torque
+substantially over its initial purely hydrodynamic value.",0508665v4
+2006-11-06,"A Magnetic Alpha-Omega Dynamo in Active Galactic Nuclei Disks: II. Magnetic Field Generation, Theories and Simulations","It is shown that a dynamo can operate in an Active Galactic Nuclei accretion
+disk due to the Keplerian shear and due to the helical motions of expanding and
+twisting plumes of plasma heated by many star passages through the disk. Each
+plume rotates a fraction of the toroidal flux into poloidal flux, always in the
+same direction, through a finite angle, and proportional to its diameter. The
+predicted growth rate of poloidal magnetic flux, based upon two analytic
+approaches and numerical simulations, leads to a rapid exponentiation of a seed
+field, \sim 0.1 to \sim 0.01 per Keplerian period of the inner part of the
+disk. The initial value of the seed field may therefore be arbitrarily small
+yet reach, through dynamo gain, saturation very early in the disk history.
+Because of tidal disruption of stars close to the black hole, the maximum
+growth rate occurs at a radius of about 100 gravitational radii from the
+central object. The generated mean magnetic field, a quadrupole field, has
+predominantly even parity so that the radial component does not reverse sign
+across the midplane. The linear growth is predicted to be the same by each of
+the following three theoretical analyses: the flux conversion model, the mean
+field approach, and numerical modeling. The common feature is the conducting
+fluid flow, considered in companion Paper I (Pariev and Colgate 2006) where two
+coherent large scale flows occur naturally: the differential winding of
+Keplerian motion and differential rotation of expanding plumes.",0611188v1
+1998-10-17,Glassy nature of stripe ordering in La(1.6-x)Nd(0.4)Sr(x)CuO(4),"We present the results of neutron-scattering studies on various aspects of
+crystalline and magnetic structure in single crystals of
+La(1.6-x)Nd(0.4)Sr(x)CuO(4) with x=0.12 and 0.15. In particular, we have
+reexamined the degree of stripe order in an x=0.12 sample. Measurements of the
+width for an elastic magnetic peak show that it saturates at a finite value
+below 30 K, corresponding to a spin-spin correlation length of 200 A. A model
+calculation indicates that the differing widths of magnetic and (previously
+reported) charge-order peaks, together with the lack of commensurability, can
+be consistently explained by disorder in the stripe spacing. Above 30 K, the
+width of the nominally elastic signal begins to increase. Interpreting the
+signal as critical scattering from slowly fluctuating spins, the temperature
+dependence of the width is consistent with renormalized classical behavior of a
+2-dimensional anisotropic Heisenberg antiferromagnet. Inelastic scattering
+measurements show that incommensurate spin excitations survive at and above 50
+K, where the elastic signal is neglible. We also report several results related
+to the LTO-to-LTT transition.",9810212v2
+2001-10-08,Quantum rotational band model for the Heisenberg molecular magnet Mo72Fe30,"We derive the low temperature properties of the molecular magnet Mo72Fe30,
+where 30 Fe(3+) paramagnetic ions occupy the sites of an icosidodecahedron and
+interact via isotropic nearest-neighbour antiferromagnetic Heisenberg exchange.
+The key idea of our model (J.S. & M.L.) is that the low-lying excitations form
+a sequence of rotational bands, i.e., for each such band the excitation
+energies depend quadratically on the total spin quantum number. For
+temperatures below 50 mK we predict that the magnetisation is described by a
+staircase with 75 equidistant steps as the magnetic field is increased up to a
+critical value and saturated for higher fields. For higher temperatures thermal
+broadening effects wash out the staircase and yield a linear ramp below the
+critical field, and this has been confirmed by our measurements (R.M.). We
+demonstrate that the lowest two rotational bands are separated by an energy gap
+of 0.7 meV, and this could be tested by EPR and inelastic neutron scattering
+measurements. We also predict the occurrence of resonances at temperatures
+below 0.1 K in the proton NMR spin-lattice relaxation rate associated with
+level crossings. As rotational bands characterize the spectra of many magnetic
+molecules our method opens a new road towards a description of their
+low-temperature behaviour which is not otherwise accessible.",0110149v1
+2002-11-24,Coexistence of Superconductivity and Magnetism in R2-xcexrusr2cu 2o10-? (R=Eu and Gd),"R2-xCexRuSr2Cu2O10-d(Ru-2122) is the first Cu-O based system in which
+superconductivity (SC) in the CuO2 planes and weak-ferromagnetism (W-FM) in the
+Ru sublattice coexists. The hole doping in the CuO2 planes, is controlled by
+appropriate variation of the Ce concentration and/or increasing the oxygen
+concentration. In Eu2-xCexRuSr2Cu2O10, SC occurs for Ce contents of 0.4-0.8,
+with the highest TC=35 K for Ce=0.6. The as-prepared non-SC EuCeRuSr2Cu2O10
+sample exhibits magnetic irreversibility below Tirr=125 K and long range o
+anti-ferromagnetic (AFM) order at TM =165 K. The saturation moment at 5 K is
+Msat=0.89 mB /Ru. Annealing under oxygen pressures, does not affect these
+parameters, whereas depletion of oxygen shifts both Tirr and TM up to 169 and
+215 K respectively. TM, Tirr and Msat decrease with x, and the Ce dependent
+magnetic-SC phase diagram is presented. A simple model for the SC and the
+long-range W-FM states is proposed. We argue that: (i) the system becomes AFM
+ordered at TM; (b) at Tirr < TM, W-FM is induced by the canting of the Ru
+moments, and (c), at lower temperatures the appropriate samples become SC at
+TC. The magnetic features are not affected by the SC state, and the two states
+coexist.",0211533v1
+2003-11-15,A new quantum fluid at high magnetic fields in the marginal charge-density-wave system $α$-(BEDT-TTF)$_2M$Hg(SCN)$_4$ (where $M=$~K and Rb),"Single crystals of the organic charge-transfer salts
+$\alpha$-(BEDT-TTF)$_2M$Hg(SCN)$_4$ have been studied using Hall-potential
+measurements ($M=$K) and magnetization experiments ($M$ = K, Rb). The data show
+that two types of screening currents occur within the high-field,
+low-temperature CDW$_x$ phases of these salts in response to time-dependent
+magnetic fields. The first, which gives rise to the induced Hall potential, is
+a free current (${\bf j}_{\rm free}$), present at the surface of the sample.
+The time constant for the decay of these currents is much longer than that
+expected from the sample resistivity. The second component of the current
+appears to be magnetic (${\bf j}_{\rm mag}$), in that it is a microscopic,
+quasi-orbital effect; it is evenly distributed within the bulk of the sample
+upon saturation. To explain these data, we propose a simple model invoking a
+new type of quantum fluid comprising a CDW coexisting with a two-dimensional
+Fermi-surface pocket which describes the two types of current. The model and
+data are able to account for the body of previous experimental data which had
+generated apparently contradictory interpretations in terms of the quantum Hall
+effect or superconductivity.",0311362v1
+2004-05-08,Magnetic phases of $t-J$ model on triangular lattice,"We study the magnetic properties of the $t-J$ model on triangular lattice in
+light of the recently discovered superconductivity in Na$_{x}$CoO$_{2}$ system.
+  We formulate the problem in the Schwinger Boson - slave Fermion scheme and
+proposed a sound mean field ansatz(canting ansatz) for the RVB order
+parameters. Working with the canting ansatz, we map out the temperature-doping
+phase diagram of the model for both sign of the hopping term. We find the
+prediction of the $t-J$ model differ drastically from that of earlier LSDA
+calculation and there is large doping range in which the system show zero net
+magnetization, rather than saturated magnetization as predicted in the LSDA
+calculation. We show the result of LSDA is unreliable in the strong coupling
+regime due to its neglect of electron correlation. We find the spin Berry phase
+play a vital role in this geometrically frustrated system and the various
+states in the phases diagram are characterized(and distinguished) by their
+respective spin Berry phase, rather than any Landau-like order parameter
+related to broken symmetry. We find the spin Berry phase is responsible for the
+qualitative difference in the low energy excitation spectrum of the various
+states of the phase diagram. We argue the phase boundary in the mean field
+phase diagram may serve as the first explicit and realistic example for phase
+transition between states with different quantum orders which in our case is
+nothing but the spin Berry phase. We also find an exotic state with nonzero
+spin chirality but no spin ordering is stable in a large temperature and doping
+range and find.......",0405164v1
+2004-06-02,Orbital and magnetic transitions in geometrically-frustrated vanadium spinels -- Monte Carlo study of an effective spin-orbital-lattice coupled model --,"We present our theoretical and numerical results on thermodynamic properties
+and the microscopic mechanism of two successive transitions in vanadium spinel
+oxides $A$V$_2$O$_4$ ($A$=Zn, Mg, or Cd) obtained by Monte Carlo calculations
+of an effective spin-orbital-lattice model in the strong correlation limit.
+Geometrical frustration in the pyrochlore lattice structure of V cations
+suppresses development of spin and orbital correlations, however, we find that
+the model exhibits two transitions at low temperatures. First, a discontinuous
+transition occurs with an orbital ordering assisted by the tetragonal
+Jahn-Teller distortion. The orbital order reduces the frustration in spin
+exchange interactions, and induces antiferromagnetic correlations in
+one-dimensional chains lying in the perpendicular planes to the tetragonal
+distortion. Secondly, at a lower temperature, a three-dimensional
+antiferromagnetic order sets in continuously, which is stabilized by the
+third-neighbor interaction among the one-dimensional antiferromagnetic chains.
+Thermal fluctuations are crucial to stabilize the collinear magnetic state by
+the order-by-disorder mechanism. The results well reproduce the experimental
+data such as transition temperatures, temperature dependence of the magnetic
+susceptibility, changes of the entropy at the transitions, and the magnetic
+ordering structure at low temperatures. Quantum fluctuation effect is also
+examined by the linear spin wave theory at zero temperature. The staggered
+moment in the ground state is found to be considerably reduced from saturated
+value, and reasonably agrees with the experimental data.",0406039v1
+2004-12-23,Quantum magnetism in two dimensions: From semi-classical Néel order to magnetic disorder,"This is a review of ground-state features of the s=1/2 Heisenberg
+antiferromagnet on two-dimensional lattices. A central issue is the interplay
+of lattice topology (e.g. coordination number, non-equivalent nearest-neighbor
+bonds, geometric frustration) and quantum fluctuations and their impact on
+possible long-range order. This article presents a unified summary of all 11
+two-dimensional uniform Archimedean lattices which include e.g. the square,
+triangular and kagome lattice. We find that the ground state of the spin-1/2
+Heisenberg antiferromagnet is likely to be semi-classically ordered in most
+cases. However, the interplay of geometric frustration and quantum fluctuations
+gives rise to a quantum paramagnetic ground state without semi-classical
+long-range order on two lattices which are precisely those among the 11 uniform
+Archimedean lattices with a highly degenerate ground state in the classical
+limit. The first one is the famous kagome lattice where many low-lying singlet
+excitations are known to arise in the spin gap. The second lattice is called
+star lattice and has a clear gap to all excitations.
+  Modification of certain bonds leads to quantum phase transitions which are
+also discussed briefly. Furthermore, we discuss the magnetization process of
+the Heisenberg antiferromagnet on the 11 Archimedean lattices, focusing on
+anomalies like plateaus and a magnetization jump just below the saturation
+field. As an illustration we discuss the two-dimensional Shastry-Sutherland
+model which is used to describe SrCu2(BO3)2.",0412662v2
+2006-09-15,Magnetic properties of iron nanoparticles prepared by exploding wire technique,"Nanoparticles of iron were prepared in distilled water using very thin iron
+wires and sheets, by the electro-exploding wire technique. Transmission
+electron microscopy reveals the size of the nanoparticles to be in the range 10
+to 50 nm. However, particles of different sizes can be segregated by using
+ultrahigh centrifuge. X-ray diffraction studies confirm the presence of the
+cubic phase of iron. These iron nanoparticles were found to exhibit
+fluorescence in the visible region in contrast to the normal bulk material. The
+room temperature hysteresis measurements upto a field of 1.0 tesla were
+performed on a suspension of iron particles in the solution as well as in the
+powders obtained by filtration. The hysteresis loops indicate that the
+particles are superparamagnetic in nature. The saturation magnetizations was ~
+60 emu / gm. As these iron particles are very sensitive to oxygen a coating of
+non-magnetic iron oxide tends to form around the particles giving it a core -
+shell structure. The core particle size is estimated theoretically from the
+magnetization measurements. Suspensions of iron nanoparticles in water have
+been proposed to be used as an effective decontaminant for ground water.",0609370v1
+2007-02-10,Direct measurement of antiferromagnetic domain fluctuations,"Measurements of magnetic noise emanating from ferromagnets due to domain
+motion were first carried out nearly 100 years ago and have underpinned much
+science and technology. Antiferromagnets, which carry no net external magnetic
+dipole moment, yet have a periodic arrangement of the electron spins extending
+over macroscopic distances, should also display magnetic noise, but this must
+be sampled at spatial wavelengths of order several interatomic spacings, rather
+than the macroscopic scales characteristic of ferromagnets. Here we present the
+first direct measurement of the fluctuations in the nanometre-scale spin-
+(charge-) density wave superstructure associated with antiferromagnetism in
+elemental Chromium. The technique used is X-ray Photon Correlation
+Spectroscopy, where coherent x-ray diffraction produces a speckle pattern that
+serves as a ""fingerprint"" of a particular magnetic domain configuration. The
+temporal evolution of the patterns corresponds to domain walls advancing and
+retreating over micron distances. While the domain wall motion is thermally
+activated at temperatures above 100K, it is not so at lower temperatures, and
+indeed has a rate which saturates at a finite value - consistent with quantum
+fluctuations - on cooling below 40K. Our work is important because it provides
+an important new measurement tool for antiferromagnetic domain engineering as
+well as revealing a fundamental new fact about spin dynamics in the simplest
+antiferromagnet.",0702265v1
+2005-12-12,Multi-monopoles and Magnetic Bags,"By analogy with the multi-vortices, we show that also multi-monopoles become
+magnetic bags in the large n limit. This simplification allows us to compute
+the spectrum and the profile functions by requiring the minimization of the
+energy of the bag. We consider in detail the case of the magnetic bag in the
+limit of vanishing potential and we find that it saturates the Bogomol'nyi
+bound and there is an infinite set of different shapes of allowed bags. This is
+consistent with the existence of a moduli space of solutions for the BPS
+multi-monopoles. We discuss the string theory interpretation of our result and
+also the relation between the 't Hooft large n limit of certain supersymmetric
+gauge theories and the large n limit of multi-monopoles. We then consider
+multi-monopoles in the cosmological contest and provide a mechanism that could
+lead to their production.",0512133v3
+2005-09-14,Why dynamos are prone to reversals,"In a recent paper (Phys. Rev. Lett. 94 (2005), 184506; physics/0411050) it
+was shown that a simple mean-field dynamo model with a spherically symmetric
+helical turbulence parameter alpha can exhibit a number of features which are
+typical for Earth's magnetic field reversals. In particular, the model produces
+asymmetric reversals, a positive correlation of field strength and interval
+length, and a bimodal field distribution. All these features are attributable
+to the magnetic field dynamics in the vicinity of an exceptional point of the
+spectrum of the non-selfadjoint dynamo operator. The negative slope of the
+growth rate curve between the nearby local maximum and the exceptional point
+makes the system unstable and drives it to the exceptional point and beyond
+into the oscillatory branch where the sign change happens. A weakness of this
+reversal model is the apparent necessity to fine-tune the magnetic Reynolds
+number and/or the radial profile of alpha. In the present paper, it is shown
+that this fine-tuning is not necessary in the case of higher supercriticality
+of the dynamo. Numerical examples and physical arguments are compiled to show
+that, with increasing magnetic Reynolds number, there is strong tendency for
+the exceptional point and the associated local maximum to move close to the
+zero growth rate line. Although exemplified again by the spherically symmetric
+alpha^2 dynamo model, the main idea of this ''self-tuning'' mechanism of
+saturated dynamos into a reversal-prone state seems well transferable to other
+dynamos. As a consequence, reversing dynamos might be much more typical and may
+occur much more frequently in nature than what could be expected from a purely
+kinematic perspective.",0509118v1
+2007-11-04,Torque magnetometry study of metamagnetic transitions in single-crystal HoNi2B2C at T\approx 1.9 K,"Metamagnetic transitions in single-crystal rare-earth nickel borocarbide
+HoNi$_2$B$_2$C have been studied at T\approx 1.9 K with a Quantum Design torque
+magnetometer. This compound is highly anisotropic with a variety of
+metamagnetic states at low temperature which includes antiferromagnetic,
+ferrimagnetic, non-collinear and ferromagnetic-like (saturated paramagnet)
+states. The critical fields of the transitions depend crucially on the angle
+$\theta$ between applied field and the easy axis [110]. Measurements of torque
+along the c-axis have been made while changing the angular direction of the
+magnetic field (parallel to basal tetragonal $ab$-planes) and with changing
+field at fixed angle over a wide angular range. Two new phase boundaries in the
+region of the non-collinear phase have been observed, and the direction of the
+magnetization in this phase has been precisely determined. At low field the
+antiferromagnetic phase is observed to be multidomain. In the angular range
+very close to the hard axis [100] ($-6^{\circ} \lesssim\phi \lesssim
+6^{\circ}$, where $\phi$ is the angle between field and the hard axis) the
+magnetic behavior is found to be ``frustrated'' with a mixture of phases with
+different directions of the magnetization.",0711.0533v1
+2008-02-13,Magnetoresistance behavior of a ferromagnetic shape memory alloy: Ni_1.75Mn_1.25Ga,"A negative-positive-negative switching behavior of magnetoresistance (MR)
+with temperature is observed in a ferromagnetic shape memory alloy
+Ni_1.75Mn_1.25Ga. In the austenitic phase between 300 and 120 K, MR is negative
+due to s-d scattering. Curiously, below 120K MR is positive, while at still
+lower temperatures in the martensitic phase, MR is negative again. The positive
+MR cannot be explained by Lorentz contribution and is related to a magnetic
+transition. Evidence for this is obtained from ab initio density functional
+theory, a decrease in magnetization and resistivity upturn at 120 K. Theory
+shows that a ferrimagnetic state with anti-ferromagnetic alignment between the
+local magnetic moments of the Mn atoms is the energetically favoured ground
+state. In the martensitic phase, there are two competing factors that govern
+the MR behavior: a dominant negative trend up to the saturation field due to
+the decrease of electron scattering at twin and domain boundaries; and a weaker
+positive trend due to the ferrimagnetic nature of the magnetic state. MR
+exhibits a hysteresis between heating and cooling that is related to the first
+order nature of the martensitic phase transition.",0802.1801v2
+2008-04-23,Size induced change-over from first to second order magnetic phase transition in La0.67Ca0.33MnO3 nanoparticles,"In this report we show that in the perovskite manganite La_{1-x}Ca_{x}MnO_3
+for a fixed x \approx 0.33, the magnetic transition changes over from first
+order to second order on reducing the particle size to nearly few tens of a
+nanometer. The change-over is brought about only by reducing the size and with
+no change in the stoichiometry. The size reduction to an average size of about
+15 nm retains the ferromagnetic state albeit with somewhat smaller saturation
+magnetization and the ferromagnetic transition temperature T_{C} is suppressed
+by a small amount (4%). The magnetization of the nanoparticles near T_{C}
+follow the scaling equation $M/|\epsilon|^\beta =
+f_\pm(H/|\epsilon|^{\gamma+\beta})$, where, $\epsilon = |T-T_C|/T_C$. The
+critical exponents, associated with the transition have been obtained from
+modified Arrott plots and they are found to be $\beta=0.47\pm 0.01$ and
+$\gamma=1.06\pm 0.03$. From a plot of M vs H at T_{C} we find the exponent
+$\delta=3.10 \pm 0.13$. All the exponents are close to the mean field values.
+The change-over of the order of the transition has been attributed to a
+lowering of the value of the derivative dT_{C}/dP due to an increased pressure
+in the nanoparticles arising due to size reduction. This effect acts in tandem
+with the rounding off effect due to random strain in the nanoparticles.",0804.3641v1
+2008-04-26,Magnetic phases evolution in the LaMn1-xFexO3+y system,"We have investigated the crystal structure and magnetic properties for
+polycrystalline samples of LaMn1-xFexO3+y, in the whole range x=0.0 to x=1.0,
+prepared by solid state reaction in air. All samples show the ORT-2
+orthorhombic structure that suppresses the Jahn-Teller distortion, thus
+favoring a ferromagnetic (FM) superexchange (SE) interaction between
+Mn^{3+}-O-Mn^{3+}. For x=0.0 the oxygen excess (y ~ 0.09) produces vacancies in
+the La and Mn sites and generates a fraction around 18% of Mn^{4+} ions and 82%
+of the usual Mn^{3+} ions, with possible double exchange interaction between
+them. The Fe doping in this system is known to produce only stable Fe^{3+}
+ions. We find an evolution from a fairly strong FM phase with a Curie
+temperature T_{C} ~ 160 K, for x=0.0, to an antiferromagnetic (AFM) phase with
+T_{N} = 790 K, for x=1.0, accompanied by clear signatures of a cluster-glass
+behavior. For intermediate Fe contents a mixed-phase state occurs, with a
+gradual decrease (increase) of the FM (AFM) phase, accompanied by a systematic
+transition broadening for 0.2 < x < 0.7. A model based on the expected exchange
+interaction among the various magnetic-ion types, accounts very well for the
+saturation-magnetization dependence on Fe doping.",0804.4250v1
+2008-06-01,3-d resistive MHD simulations of magnetic reconnection and the tearing mode instability in current sheets,"Magnetic reconnection plays a critical role in many astrophysical processes
+where high energy emission is observed, e.g. particle acceleration,
+relativistic accretion powered outflows, pulsar winds and probably in
+dissipation of Poynting flux in GRBs. The magnetic field acts as a reservoir of
+energy and can dissipate its energy to thermal and kinetic energy via the
+tearing mode instability. We have performed 3d nonlinear MHD simulations of the
+tearing mode instability in a current sheet. Results from a temporal stability
+analysis in both the linear regime and weakly nonlinear (Rutherford) regime are
+compared to the numerical simulations. We observe magnetic island formation,
+island merging and oscillation once the instability has saturated. The growth
+in the linear regime is exponential in agreement with linear theory. In the
+second, Rutherford regime the island width grows linearly with time. We find
+that thermal energy produced in the current sheet strongly dominates the
+kinetic energy. Finally preliminary analysis indicates a P(k) 4.8 power law for
+the power spectral density which suggests that the tearing mode vortices play a
+role in setting up an energy cascade.",0806.0144v1
+2008-06-26,Ferromagnetic resonance force spectroscopy of individual sub-micron size samples,"We review how a magnetic resonance force microscope (MRFM) can be applied to
+perform ferromagnetic resonance (FMR) spectroscopy of \emph{individual}
+sub-micron size samples. We restrict our attention to a thorough study of the
+spin-wave eigen-modes excited in permalloy (Py) disks patterned out of the same
+43.3 nm thin film. The disks have a diameter of either 1.0 or $0.5 \mu$m and
+are quasi-saturated by a perpendicularly applied magnetic field. It is shown
+that \emph{quantitative} spectroscopic information can be extracted from the
+MRFM measurements. In particular, the data are extensively compared with
+complementary approximate models of the dynamical susceptibility: i) a 2D
+analytical model, which assumes an homogeneous magnetization dynamics along the
+thickness and ii) a full 3D micromagnetic simulation, which assumes an
+homogeneous magnetization dynamics below a characteristic length scale $c$ and
+which approximates the cylindrical sample volume by a discretized
+representation with regular cubic mesh of lateral size $c=3.9$ nm. In our
+analysis, the distortions due to a breaking of the axial symmetry are taken
+into account, both models incorporating the possibility of a small misalignment
+between the applied field and the normal of the disks.",0806.4244v1
+2008-07-22,"Microphysical dissipation, turbulence and magnetic fields in hyper-accreting discs","Hyper-accreting discs occur in compact-object mergers and collapsars, and may
+power gamma-ray bursts (GRBs). We calculate the microscopic viscosity and
+resistivity of plasma in these discs, and discuss the implications for their
+global structure and evolution. In the neutrino-cooled innermost regions, the
+viscosity is provided mainly by mildly degenerate electrons, while the
+resistivity is modified from the Spitzer value due to the effects of both
+relativity and degeneracy. The plasma behaves as an almost ideal MHD fluid.
+Among the non-ideal MHD effects the Hall term is relatively the most important,
+while the magnetic Prandtl number, Pr (the ratio of viscosity to resistivity),
+is typically larger than unity: 10 < Pr < 6000. The outer radiatively
+inefficient regions also display high Pr. Numerical simulations of the
+magneto-rotational instability indicate that the saturation level and angular
+momentum transport efficiency may be greatly enhanced at high Pr. If this
+behaviour persists in the presence of a strong Hall effect we would expect that
+hyper-accreting discs should be strongly magnetised and highly variable. The
+expulsion of magnetic field that cannot be dissipated at small scales may also
+favour a magnetic outflow. We note the similaries between the Prandtl number in
+hyper-accreting discs and X-ray binary discs, which suggests that a comparison
+between late-time activity in GRBs and X-ray binary accretion states may be
+fruitful. Our results imply that the behavior of high Prandtl number MHD flows
+needs to be considered in studies of hyper-accreting discs.",0807.3547v2
+2008-11-24,Three-Dimensional Relativistic MHD Simulations of the Kelvin-Helmholtz Instability: Magnetic Field Amplification by a Turbulent Dynamo,"Magnetic field strengths inferred for relativistic outflows including
+gamma-ray bursts (GRB) and active galactic nuclei (AGN) are larger than naively
+expected by orders of magnitude. We present three-dimensional relativistic
+magnetohydrodynamics (MHD) simulations demonstrating amplification and
+saturation of magnetic field by a macroscopic turbulent dynamo triggered by the
+Kelvin-Helmholtz shear instability. We find rapid growth of electromagnetic
+energy due to the stretching and folding of field lines in the turbulent
+velocity field resulting from non-linear development of the instability. Using
+conditions relevant for GRB internal shocks and late phases of GRB afterglow,
+we obtain amplification of the electromagnetic energy fraction to $\epsilon_B
+\sim 5 \times 10^{-3}$. This value decays slowly after the shear is dissipated
+and appears to be largely independent of the initial field strength. The
+conditions required for operation of the dynamo are the presence of velocity
+shear and some seed magnetization both of which are expected to be commonplace.
+We also find that the turbulent kinetic energy spectrum for the case studied
+obeys Kolmogorov's 5/3 law and that the electromagnetic energy spectrum is
+essentially flat with the bulk of the electromagnetic energy at small scales.",0811.3638v2
+2009-02-17,A Model for Emission from Jets in X-ray Binaries: Consequences of a Single Acceleration Episode,"There are strong evidence for powerful jets in the low/hard state of
+black-hole X-ray binaries (BHXRBs). Here, we present a model in which electrons
+are accelerated once at the base of the jet, and are cooled by synchrotron
+emission and possible adiabatic energy losses. The accelerated electrons assume
+a Maxwellian distribution at low energies and possible energetic power law
+tail. These assumptions yield to a wealth of spectra, which we study in
+details. We identify critical values of the magnetic field, and five transition
+frequencies in the spectra. In particular, we show that: (I) the decay of the
+magnetic field along the jet enables, for wide jets, production of flat radio
+spectra without the need for electrons re-acceleration along the jet. (II) An
+increase of the magnetic field above a critical value of ~10^5 G leads to a
+sharp decrease in the flux at the radio band, while the flux at higher
+frequencies saturates to a constant value. (III) For strong magnetic field, the
+flux decays in the optical/UV band as F_nu ~ nu^{-1/2}, irrespective of the
+electrons initial distribution. (IV) For B_0 ~ 10^4 G, the X-ray flux gradually
+steepens. (V) With adiabatic energy losses, flat spectrum can be obtained only
+at a limited frequency range, and under certain conditions (VI) For narrow
+jets, r(x) ~ x^{alpha} with alpha < 1/2, flat radio spectrum cannot be
+obtained. We provide full description of the spectrum in the different
+scenarios, and show that our model is consistent with the key observed
+properties of BHXRBs.",0902.2892v2
+2009-06-16,"The Meissner Effect and Vortex Expulsion in Color-Superconducting Quark stars, and its Role for Re-heating of Magnetars","Compact stars made of quark matter rather than confined hadronic matter, are
+expected to form a color superconductor. This superconductor ought to be
+threaded with rotational vortex lines, within which the star's interior
+magnetic field is at least partially confined. The vortices (and thus magnetic
+flux) would be expelled from the star during stellar spin-down, leading to
+magnetic reconnection at the surface of the star and the prolific production of
+thermal energy. In this paper, we show that this energy release can re-heat
+quark stars to exceptionally high temperatures, such as observed for Soft Gamma
+Repeaters (SGRs), Anomalous X-Ray pulsars (AXPs), and X-ray dim isolated
+neutron stars (XDINs). Moreover, our numerical investigations of the
+temperature evolution, spin-down rate, and magnetic field behavior of such
+superconducting quark stars suggest that SGRs, AXPs, and XDINs may be linked
+ancestrally. Finally, we discuss the possibility of a time delay before the
+star enters the color superconducting phase, which can be used to estimate the
+density at which quarks deconfine. From observations, we find this density to
+be of the order of five times that of nuclear saturation.",0906.3043v2
+2009-06-26,High-field magnetization of a two dimensional spin frustration system Ni$_{5}$(TeO$_{3}$)$_{4}$X$_{2}$ (X = Br and Cl),"High-field magnetization, M($H$), on Ni$_{5}$(TeO$_{3}$)$_{4}$X$_{2}$ (X = Br
+and Cl) were measured by using a pulse magnet. These compounds have a two
+dimensional crystal structure and a distorted kagome spin frustrated system
+which is builded by the Ni$^{2+}$ ions ($\textbf{S}$ = 1). The N\'eel
+transition temperatures are $T_{N} \sim$ 28 and 23 K for X = Br and Cl,
+respectively. When $T < T_{N}$, we observed a step-like transition at $H_{c}
+\sim$ 11 and 10 T for X = Br and Cl, respectively. On the other hand, at $T >
+T_{N}$, the field-dependent magnetization curves behaved like a monotonically
+increasing straight line up to 55 T. The $H_{c}$ value is close to those
+obtained by previous spin resonance studies in which a model of spin-flop
+scenario was proposed to explain the field-dependent resonance spectra. Their
+model predicts a further transition at around 23 T, however, our observations
+did not show any plateau behaviors, saturation or other anomalies up to 55 T,
+suggesting that the further transition possibly exists at a much higher field
+region.",0906.4856v1
+2009-07-12,Odd triplet superconductivity in clean and moderately disordered SFFS junctions,"We study the Josephson effect and pairing correlations in SFFS junctions that
+consist of conventional superconductors (S) connected through two metallic
+monodomain ferromagnets (F) with transparent and spin inactive interfaces. We
+solve the Eilenberger equations for arbitrary relative orientation of
+magnetizations of the two F layers in the clean limit and for moderate disorder
+in ferromagnets. Spatial variation of pair amplitudes, singlet $f_s$, and odd
+in frequency triplet $f_{t0}$ and $f_{t1}$, with 0 and $\pm1$ spin projections,
+as well as the Josephson current-phase relations are calculated for different
+values of the ferromagnetic layers thickness and angle $\alpha$ between
+in-plane magnetizations. In contrast to the dirty limit case, we find that for
+$0<\alpha<\pi$ both spin singlet and triplet pair amplitudes in F layers
+power-law decay in the same oscillatory manner with distance from the FS
+interfaces. This decay gets faster as the impurity-scattering rate in
+ferromagnets is increased. The computed triplet amplitude $f_{t1}$ has opposite
+signs in the two magnet regions, penetrates into the superconductors and
+monotonically decays over the same distance, which is the superconducting
+coherence length, as the singlet amplitude $f_s$ saturates to the bulk value.
+We point out that influence of misorientation of magnetizations on the
+Josephson current can not be attributed directly to the appearance of odd
+triplet correlations.",0907.2042v1
+2009-12-22,Impurity effects in coupled-ladder BiCu2PO6 studied by NMR and quantum Monte Carlo simulations,"We present a 31P NMR study of the coupled spin 1/2 ladder compound BiCu2PO6.
+In the pure material, intrinsic susceptibility and dynamics show a spin gap of
+about . Substitution of non magnetic Zn or magnetic Ni impurity at Cu site
+induces a staggered magnetization which results in a broadening of the 31P NMR
+line, while susceptibility far from the defects is unaffected. The effect of Ni
+on the NMR line broadening is twice that of Zn, which is consistent with
+Quantum Monte Carlo (QMC) calculations assuming that Ni couples
+ferromagnetically to its adjacent Cu. The induced moment follows a 1/T
+temperature dependence due to the Curie-like development of the moment
+amplitude while its extension saturates and does not depend on impurity content
+or nature. This allow us to verify the generically expected scenario for
+impurity doping and to extend it to magnetic impurity case: in an
+antiferromagnetically correlated low dimensional spin system with
+antiferromagnetic correlations, any type of impurity induces a staggered moment
+at low temperature, whose extension is not linked to the impurity nature but to
+the intrinsic physics at play in the undoped pure system, from 1D to 2D
+systems.",0912.4353v3
+2010-07-28,Vortex Dynamics in Color-Superconducting Quark stars: The Re-heating of Magnetars,"Compact stars made of quark matter rather than confined hadronic matter, are
+expected to form a color superconductor. This superconductor ought to be
+threaded with rotational vortex lines within which the star's interior magnetic
+field is confined. The vortices (and thus magnetic flux) would be expelled from
+the star during stellar spin-down, leading to magnetic reconnection at the
+surface of the star and the prolific production of thermal energy. In this
+Letter, we show that this energy release can re-heat quark stars to
+exceptionally high temperatures, such as observed for Soft Gamma Repeaters
+(SGRs), Anomalous X-Ray pulsars (AXPs), and X-ray dim isolated neutron stars
+(XDINs). Moreover, our numerical investigations of the temperature evolution,
+spin-down rate, and magnetic field behavior of such superconducting quark stars
+suggest that SGRs, AXPs, and XDINs may be linked ancestrally. Finally, we
+discuss the possibility of a time delay before the star enters the color
+superconducting phase, which can be used to estimate the density at which
+quarks deconfine. We find this density to be five times that of nuclear
+saturation.",1007.4860v1
+2010-08-07,T=0 phase diagram and nature of domains in ultrathin ferromagnetic films with perpendicular anisotropy,"We present the complete zero temperature phase diagram of a model for
+ultrathin films with perpendicular anisotropy. The whole parameter space of
+relevant coupling constants is studied in first order anisotropy approximation.
+Because the ground state is known to be formed by perpendicular stripes
+separated by Bloch walls, a standard variational approach is used, complemented
+with specially designed Monte Carlo simulations. We can distinguish four
+regimes according to the different nature of striped domains: a high anisotropy
+Ising regime with sharp domain walls, a saturated stripe regime with thicker
+walls inside which an in-plane component of the magnetization develops, a
+narrow canted-like regime, characterized by a sinusoidal variation of both the
+in-plane and the out of plane magnetization components, which upon further
+decrease of the anisotropy leads to an in-plane ferromagnetic state via a spin
+reorientation transition (SRT). The nature of domains and walls are described
+in some detail together with the variation of domain width with anisotropy, for
+any value of exchange and dipolar interactions. Our results, although strictly
+valid at $T=0$, can be valuable for interpreting data on the evolution of
+domain width at finite temperature, a still largely open problem.",1008.1353v1
+2010-11-02,Electron transport and anisotropy of the upper critical magnetic field in a Ba0.68K0.32Fe2As2 single crystals,"Early work on the iron-arsenide compounds supported the view, that a reduced
+dimensionality might be a necessary prerequisite for high-Tc superconductivity.
+Later, however, it was found that the zero-temperature upper critical magnetic
+field, Hc2(0), for the 122 iron pnictides is in fact rather isotropic. Here, we
+report measurements of the temperature dependence of the electrical
+resistivity, \Gamma(T), in Ba0.5K0.5Fe2As2 and Ba0.68K0.32Fe2As2 single
+crystals in zero magnetic field and for Ba0.68K0.32Fe2As2 as well in static and
+pulsed magnetic fields up to 60 T. We find that the resistivity of both
+compounds in zero field is well described by an exponential term due to
+inter-sheet umklapp electron-phonon scattering between light electrons around
+the M point to heavy hole sheets at the \Gamma point in reciprocal space. From
+our data, we construct an H-T phase diagram for the inter-plane (H || c) and
+in-plane (H || ab) directions for Ba0.68K0.32Fe2As2. Contrary to published data
+for underdoped 122 FeAs compounds, we find that Hc2(T) is in fact anisotropic
+in optimally doped samples down to low temperatures. The anisotropy parameter,
+{\gamma} = Habc2/Hcc2, is about 2.2 at Tc. For both field orientations we find
+a concave curvature of the Hc2 lines with decreasing anisotropy and saturation
+towards lower temperature. Taking into account Pauli spin paramagnetism we
+perfectly can describe Hc2(T) and its anisotropy.",1011.0698v1
+2011-03-11,Optimized fabrication of high quality La0.67Sr0.33MnO3 thin films considering all essential characteristics,"In this article, an overview of the fabrication and properties of high
+quality La0.67Sr0.33MnO3 (LSMO) thin films is given. A high quality LSMO film
+combines a smooth surface morphology with a large magnetization and a small
+residual resistivity, while avoiding precipitates and surface segregation. In
+literature, typically only a few of these issues are adressed. We therefore
+present a thorough characterization of our films, which were grown by pulsed
+laser deposition. The films were characterized with reflection high energy
+electron diffraction, atomic force microscopy, x-ray diffraction, magnetization
+and transport measurements, x-ray photoelectron spectroscopy and scanning
+transmission electron microscopy. The films have a saturation magnetization of
+4.0 {\mu}B/Mn, a Curie temperature of 350 K and a residual resistivity of 60
+{\mu}{\Omega}cm. These results indicate that high quality films, combining both
+large magnetization and small residual resistivity, were realized. A comparison
+between different samples presented in literature shows that focussing on a
+single property is insufficient for the optimization of the deposition process.
+For high quality films, all properties have to be adressed. For LSMO devices,
+the thin film quality is crucial for the device performance. Therefore, this
+research is important for the application of LSMO in devices.",1103.2267v1
+2011-08-09,Numerical Simulations of Driven Relativistic MHD Turbulence,"A wide variety of astrophysical phenomena involve the flow of turbulent
+magnetized gas with relativistic velocity or energy density. Examples include
+gamma-ray bursts, active galactic nuclei, pulsars, magnetars, micro-quasars,
+merging neutron stars, X-ray binaries, some supernovae, and the early universe.
+In order to elucidate the basic properties of the relativistic
+magnetohydrodynamical (RMHD) turbulence present in these systems, we present
+results from numerical simulations of fully developed driven turbulence in a
+relativistically warm, weakly magnetized and mildly compressible ideal fluid.
+We have evolved the RMHD equations for many dynamical times on a uniform grid
+with 1024^3 zones using a high order Godunov code. We observe the growth of
+magnetic energy from a seed field through saturation at about 1% of the total
+fluid energy. We compute the power spectrum of velocity and density-weighted
+velocity and conclude that the inertial scaling is consistent with a slope of
+-5/3. We compute the longitudinal and transverse velocity structure functions
+of order p up to 11, and discuss their possible deviation from the expected
+scaling for non-relativistic media. We also compute the scale-dependent
+distortion of coherent velocity structures with respect to the local magnetic
+field, finding a weaker scale dependence than is expected for incompressible
+non-relativistic flows with a strong mean field.",1108.1991v2
+2011-08-19,Structure and magnetic properties of nanostructured Pd-Fe thin films produced by pulse electrodeposition,"Nanostructured Pd-Fe thin films with varied Fe content were prepared by
+electrodeposition technique from organic electrolytes on Cu and brass
+substrates. The structure and the magnetic properties of the films were
+investigated prior to post-deposition annealing. The structure of the Pd1-xFex
+thin films with x = 0.14, 0.24, and 0.52 was determined by X-ray diffraction
+(XRD) and transmission electron microscopy (TEM) as a solid solution of iron in
+palladium face-centered cubic lattice with the (111) orientation of nanograins
+relatively to the substrate surface. The films with higher iron concentration,
+x = 0.74, 0.91, have structure of a solid solution based on the body-centered
+cubic lattice. The average grain size determined by the scanning electron
+microscopy (SEM) for the first two alloys is 7-10 nm, and for the latter ones
+it is about 120 nm. The saturation magnetization of the films has linear
+dependence on the iron content, but coercivity has non-monotonic dependence on
+x, i.e. the films with x = 0.68 show highest coercivity. The magnetic
+anisotropy of the samples is studied by ferromagnetic resonance (FMR)
+spectroscopy.",1108.3888v1
+2011-09-15,Surface impedance of superconductors with magnetic impurities,"Motivated by the problem of the residual surface resistance of the
+superconducting radio-frequency (SRF) cavities, we develop a microscopic theory
+of the surface impedance of s-wave superconductors with magnetic impurities. We
+analytically calculate the current response function and surface impedance for
+a sample with spatially uniform distribution of impurities, treating magnetic
+impurities in the framework of the Shiba theory. The obtained general
+expressions hold in a wide range of parameter values, such as temperature,
+frequency, mean free path, and exchange coupling strength. This generality, on
+the one hand, allows for direct numerical implementation of our results to
+describe experimental systems (SRF cavities, superconducting qubits) under
+various practically relevant conditions. On the other hand, explicit analytical
+expressions can be obtained in a number of limiting cases, which makes possible
+further theoretical investigation of certain regimes. As a feature of key
+relevance to SRF cavities, we show that in the regime of ""gapless
+superconductivity"" the surface resistance exhibits saturation at zero
+temperature. Our theory thus explicitly demonstrates that magnetic impurities,
+presumably contained in the oxide surface layer of the SRF cavities, provide a
+microscopic mechanism for the residual resistance.",1109.3395v2
+2011-10-03,Magnetic and density spikes in cosmic ray shock precursors,"In shock precursors populated by accelerated cosmic rays (CR), the CR return
+current instability is believed to significantly enhance the pre-shock
+perturbations of magnetic field. We have obtained fully-nonlinear exact ideal
+MHD solutions supported by the CR return current. The solutions occur as
+localized spikes of circularly polarized Alfven envelopes (solitons, or
+breathers). As the conventional (undriven) solitons, the obtained magnetic
+spikes propagate at a speed $C$ proportional to their amplitude,
+$C=C_{A}B_{{\rm max}}/\sqrt{2}B_{0}$. The sufficiently strong solitons run thus
+ahead of the main shock and stand in the precursor, being supported by the
+return current. This property of the nonlinear solutions is strikingly
+different from the linear theory that predicts non-propagating (that is,
+convected downstream) circularly polarized waves. The nonlinear solutions may
+come either in isolated pulses (solitons) or in soliton-trains (cnoidal waves).
+The morphological similarity of such quasi-periodic soliton chains with
+recently observed X-ray stripes in Tycho supernova remnant (SNR) is briefly
+discussed. The magnetic field amplification determined by the suggested
+saturation process is obtained as a function of decreasing SNR blast wave
+velocity during its evolution from the ejecta-dominated to the Sedov-Taylor
+stage.",1110.0257v1
+2011-12-19,Magnetic Fields in Population III Star Formation,"We study the buildup of magnetic fields during the formation of Population
+III star-forming regions, by conducting cosmological simulations from realistic
+initial conditions and varying the Jeans resolution. To investigate this in
+detail, we start simulations from identical initial conditions, mandating 16,
+32 and 64 zones per Jeans length, and studied the variation in their magnetic
+field amplification. We find that, while compression results in some
+amplification, turbulent velocity fluctuations driven by the collapse can
+further amplify an initially weak seed field via dynamo action, provided there
+is sufficient numerical resolution to capture vortical motions (we find this
+requirement to be 64 zones per Jeans length, slightly larger than, but
+consistent with previous work run with more idealized collapse scenarios). We
+explore saturation of amplification of the magnetic field, which could
+potentially become dynamically important in subsequent, fully-resolved
+calculations. We have also identified a relatively surprising phenomena that is
+purely hydrodynamic: the higher-resolved simulations possess substantially
+different characteristics, including higher infall-velocity, increased
+temperatures inside 1000 AU, and decreased molecular hydrogen content in the
+innermost region. Furthermore, we find that disk formation is suppressed in
+higher-resolution calculations, at least at the times that we can follow the
+calculation. We discuss the effect this may have on the buildup of disks over
+the accretion history of the first clump to form as well as the potential for
+gravitational instabilities to develop and induce fragmentation.",1112.4479v1
+2012-02-14,Influence of e-e scattering on the temperature dependence of the resistance of a classical ballistic point contact in a two-dimensional electron system,"We experimentally investigate the temperature (T) dependence of the
+resistance of a classical ballistic point contact (PC) in a two-dimensional
+electron system (2DES). The split-gate PC is realized in a high-quality
+AlGaAs/GaAs heterostructure. The PC resistance is found to drop by more than
+10% as T is raised from 0.5 K to 4.2 K. In the absence of a magnetic field, the
+T dependence is roughly linear below 2 K and tends to saturate at higher T.
+Perpendicular magnetic fields on the order of a few 10 mT suppress the
+T-dependent contribution dR. This effect is more pronounced at lower
+temperatures, causing a crossover to a nearly parabolic T dependence in a
+magnetic field. The normalized magnetic field dependencies dR(B) permit an
+empiric single parameter scaling in a wide range of PC gate voltages. These
+observations give strong evidence for the influence of electron-electron (e-e)
+scattering on the resistance of ballistic PCs. Our results are in qualitative
+agreement with a recent theory of the e-e scattering based T dependence of the
+conductance of classical ballistic PCs [ Phys. Rev. Lett. 101 216807 (2008) and
+Phys. Rev. B 81 125316 (2010)].",1202.2952v3
+2012-08-21,High temperature structural and magnetic properties of cobalt nanowires,"We present in this paper the structural and magnetic properties of high
+aspect ratio Co nanoparticles (~10) at high temperatures (up to 623 K) using in
+situ X ray diffraction (XRD) and SQUID characterizations. We show that the
+anisotropic shapes, the structural and texture properties are preserved up to
+500 K. The coercivity can be modelled by u0Hc=2(Kmc+Kshape)/Ms with Kmc the
+magnetocrystalline anisotropy constant, Kshape the shape anisotropy constant
+and Ms the saturation magnetization. Hc decreases linearly when the temperature
+is increased due to the loss of the Co magnetocrystalline anisotropy
+contribution. At 500K, 50% of the room temperature coercivity is preserved
+corresponding to the shape anisotropy contribution only. We show that the
+coercivity drop is reversible in the range 300 - 500 K in good agreement with
+the absence of particle alteration. Above 525 K, the magnetic properties are
+irreversibly altered either by sintering or by oxidation.",1208.4403v2
+2013-01-25,Magnetic penetration depth in single crystals of SrPd$_2$Ge$_2$ superconductor,"The in-plane magnetic penetration depth, $\lambda_m(T)$, was measured in
+single crystals of SrPd$_2$Ge$_2$ superconductor in a dilution refrigerator
+down to T=60 mK and in magnetic fields up to $H_{dc} = 1$ T by using a tunnel
+diode resonator. The London penetration depth, $\lambda$, saturates
+exponentially approaching $T\rightarrow 0$ indicating fully gapped
+superconductivity. The thermodynamic Rutgers formula was used to estimate
+$\lambda(0) = 426$ nm which was used to calculate the superfluid density,
+$\rho_s(T)=\lambda^2(0)/\lambda^2(T)$. Analysis of $\rho_s(T)$ in the full
+temperature range shows that it is best described by a single - gap behavior,
+perhaps with somewhat stronger coupling. In a magnetic field, the measured
+penetration depth is given by the Campbell penetration depth which was used to
+calculate the theoretical critical current density $j_c$. For $H \le 0.45$ T,
+the strongest pinning is achieved not at the lowest, but at some intermediate
+temperature, probably due to matching effect between temperature - dependent
+coherence length and relevant pinning lengthscale. Finally, we find a
+compelling evidence for surface superconductivity. Combining all measurements,
+the entire $H$-$T$ phase diagram of SrPd$_2$Ge$_2$ is constructed with an
+estimated $H_{c2}(0)=0.4817$ T.",1301.6054v2
+2013-01-28,Surfactant mediated growth of ferromagnetic Mn δ-doped Si,"We present an investigation of Mn {\delta}-doped layers in Si(001) grown by
+molecular beam epitaxy. We discovered that a Pb surfactant has significant
+effect on the structural and magnetic properties of the submonolayer of Mn,
+which depends on the Si capping layer growth temperature, T_Si, and the Mn
+coverage, {\theta}_Mn. The results presented in this paper identify three
+regions in the growth-phase-diagram characterized by distinct magnetic
+behaviors and crystal structures. In one region, X-ray absorption fine
+structure (XAFS) and transmission electron microscopy (TEM) experiments
+indicate that MnSi nanocrystallites form with B2-like crystal type structures.
+At the optimal growth conditions, T_Si = 200 C and {\theta}_Mn = 0.26
+monolayer, a ferromagnetic phase develops with a Curie temperature T_C > 400 K
+and a saturation moment m_sat = 1.56 {\mu}_B/Mn, whereas T_C drops to zero for
+a control sample prepared without Pb. For T_Si > 200 C, MnSi-B20 type
+precipitates form with a T_C ~ 170 K. Rutherford backscattering spectroscopy
+shows that the increase in the remanent magnetization in these two phases is
+possibly correlated with an increase in the Mn substitutional fraction, which
+suggests that a Si_{1-x}Mn_x dilute magnetic semiconductor may be forming in
+the matrix between the precipitates. Density functional calculations show that
+Pb changes the pathway by which the Mn atoms access the Si substitutional
+sites, Mn_Si. While the Pb increases the formation energy of Mn_Si at the Si
+surface, it enables substitutional incorporation by lowering the formation
+energy of Si vacancies by 0.92 eV.",1301.6651v1
+2013-07-27,Strain-induced effects on the magnetic and electronic properties of epitaxial Fe$_{1-x}$Co$_{x}$Si thin films,"We have investigated the Co-doping dependence of the structural, transport,
+and magnetic properties of \epsilon-FeCoSi epilayers grown by molecular beam
+epitaxy on silicon (111) substrates. Low energy electron diffraction, atomic
+force microscopy, X-ray diffraction, and high resolution transmission electron
+microscopy studies have confirmed the growth of phase-pure, defect-free
+\epsilon-FeCoSi epitaxial films with a surface roughness of ~1 nm. These
+epilayers are strained due to lattice mismatch with the substrate, deforming
+the cubic B20 lattice so that it becomes rhombohedral. The temperature
+dependence of the resistivity changes as the Co concentration is increased,
+being semiconducting-like for low $x$ and metallic-like for x \gtrsim 0.3. The
+films exhibit the positive linear magnetoresistance that is characteristic of
+\epsilon-FeCoSi below their magnetic ordering temperatures $T_\mathrm{ord}$, as
+well as the huge anomalous Hall effect of order several \mu\Omega cm. The
+ordering temperatures are higher than those observed in bulk, up to 77 K for x
+= 0.4. The saturation magnetic moment of the films varies as a function of Co
+doping, with a contribution of ~1 \mu_{B}/ Co atom for x \lesssim 0.25. When
+taken in combination with the carrier density derived from the ordinary Hall
+effect, this signifies a highly spin-polarised electron gas in the low x,
+semiconducting regime.",1307.7301v1
+2013-08-16,Theory of metallic double perovskites with spin orbit coupling and strong correlations; application to ferrimagnetic Ba2FeReO6,"We consider a model of the double perovskite Ba2FeReO6, a room temperature
+ferrimagnet with correlated and spin-orbit coupled Re t2g electrons moving in
+the background of Fe moments stabilized by Hund's coupling. We show that for
+such 3d/5d double perovskites, strong correlations on the 5d-element (Re) are
+essential in driving a half-metallic ground state. Incorporating both strong
+spin-orbit coupling and the Hubbard repulsion on Re leads to a band structure
+consistent with ab initio calculations. Using our model, we find a large spin
+polarization at the Fermi level, and obtain a semi-quantitative understanding
+of the saturation magnetization of Ba2FeReO6, as well as X-ray magnetic
+circular dichroism data indicating a significant orbital magnetization. Based
+on the orbital populations obtained in our theory, we predict a specific doping
+dependence to the tetragonal distortion accompanying ferrimagnetic order.
+Finally, the combination of a net magnetization and spin-orbit interactions is
+shown to induce Weyl nodes in the band structure, and we predict a significant
+intrinsic anomalous Hall effect in hole-doped Ba2FeReO6. The uncovered
+interplay of strong correlations and spin-orbit coupling lends partial support
+to our previous work, which used a local moment description to capture the spin
+wave dispersion found in neutron scattering measurements. Our work is of broad
+interest for understanding metallic 4d-based and 5d-based double perovskites
+which are of fundamental interest and of possible relevance to spintronic
+applications.",1308.3701v2
+2013-08-30,Spin-polarized electronic structure of the core-shell ZnO/ZnO:Mn nanowires probed by x-ray absorption and emission spectroscopy,"The combination of x-ray spectroscopy methods complemented with theoretical
+analysis unravels the coexistence of paramagnetic and antiferromagnetic phases
+in the Zn_0.9Mn_0.1O shell deposited onto array of wurtzite ZnO nanowires. The
+shell is crystalline with orientation toward the ZnO growth axis, as
+demonstrated by X-ray linear dichroism. EXAFS analysis confirmed that more than
+90% of Mn atoms substituted Zn in the shell while fraction of secondary phases
+was below 10%. The value of manganese spin magnetic moment was estimated from
+the Mn K{\beta} X-ray emission spectroscopy to be 4.3{\mu}B which is close to
+the theoretical value for substitutional Mn_Zn. However the analysis of L_2,3
+x-ray magnetic circular dichroism data showed paramagnetic behaviour with
+saturated spin magnetic moment value of 1.95{\mu}B as determined directly from
+the spin sum rule. After quantitative analysis employing atomic multiplet
+simulations such difference was explained by a coexistence of paramagnetic
+phase and local antiferromagnetic coupling of Mn magnetic moments. Finally,
+spin-polarized electron density of states was probed by the spin-resolved Mn
+K-edge XANES spectroscopy and consequently analyzed by band structure
+calculations.",1308.6654v1
+2013-10-25,Electronic properties of Co$_{2}$FeSi investigated by x-ray magnetic linear dichroism,"We present experimental XMLD spectra measured on epitaxial (001)-oriented
+thin Co$_{2}$FeSi films, which are rich in features and depend sensitively on
+the degree of atomic order and interdiffusion from capping layers. Al- and
+Cr-capped films with different degrees of atomic order were prepared by DC
+magnetron sputtering by varying the deposition temperatures. The local
+structural properties of the film samples were additionally investigated by
+nuclear magnetic resonance (NMR) measurements. The XMLD spectra of the
+different samples show clear and uniform trends at the $L_{3,2}$ edges. The
+Al-capped samples show similar behavior as previous measured XMLD spectra of
+Co$_2$FeSi$_{0.6}$Al$_{0.4}$. Thus, we assume that during deposition Al atoms
+are being implanted into the subsurface of Co$_{2}$FeSi. Such an interdiffusion
+is not observed for the corresponding Cr-capped films, which makes Cr the
+material of choice for capping Co$_{2}$FeSi films. We report stronger XMLD
+intensities at the $L_{3,2}$ Co and Fe egdes for films with a higher saturation
+magnetization. Additionally, we compare the spectra with \textit{ab initio}
+predictions and obtain a reasonably good agreement. Furthermore, we were able
+to detect an XMCD signal at the Si $L$-edge, indicating the presence of a
+magnetic moment at the Si atoms.",1310.6910v3
+2014-02-11,Spatial Growth of the Current-Driven Instability in Relativistic Jets,"We have investigated the influence of velocity shear and a radial density
+profile on the spatial development of the current driven kink instability along
+helically magnetized relativistic jets via three-dimensional relativistic
+magnetohydrodynamic simulations. In this study, we use a non-periodic
+computational box, the jet flow is initially established across the
+computational grid, and a precessional perturbation at the inlet triggers
+growth of the kink instability. If the velocity shear radius is located inside
+the characteristic radius of the helical magnetic field, a static
+non-propagating current driven kink is excited as the perturbation propagates
+down the jet. Temporal growth disrupts the initial flow across the
+computational grid not too far from the inlet. On the other hand, if the
+velocity shear radius is outside the characteristic radius of the helical
+magnetic field, the kink is advected with the flow and grows spatially down the
+jet. In this case flow is maintained to much larger distances from the inlet.
+The effect of different radial density profiles is more subtle. When the
+density increases with radius, the kink appears to saturate by the end of the
+simulation without apparent disruption of the helical twist. This behavior
+suggests that relativistic jets consisting of a tenuous spine surrounded by a
+denser medium with a velocity shear radius outside the radius of maximum
+toroidal magnetic field have a relatively stable configuration.",1402.2370v1
+2014-02-26,Mean-field dynamos: the old concept and some recent developments,"This article reproduces the Karl Schwarzschild lecture 2013. Some of the
+basic ideas of electrodynamics and magnetohydrodynamics of mean fields in
+turbulently moving conducting fluids are explained. It is stressed that the
+connection of the mean electromotive force with the mean magnetic field and its
+first spatial derivatives is in general neither local nor instantaneous and
+that quite a few claims concerning pretended failures of the mean-field concept
+result from ignoring this aspect. In addition to the mean-field dynamo
+mechanisms of $\alpha^2$ and $\alpha$ $\Omega$ type several others are
+considered. Much progress in mean-field electrodynamics and
+magnetohydrodynamics results from the test-field method for calculating the
+coefficients that determine the connection of the mean electromotive force with
+the mean magnetic field. As an important example the memory effect in
+homogeneous isotropic turbulence is explained. In magnetohydrodynamic
+turbulence there is the possibility of a mean electromotive force that is
+primarily independent of the mean magnetic field and labeled as Yoshizawa
+effect. Despite of many efforts there is so far no convincing comprehensive
+theory of $\alpha$ quenching, that is, the reduction of the $\alpha$ effect
+with growing mean magnetic field, and of the saturation of mean-field dynamos.
+Steps toward such a theory are explained. Finally, some remarks on laboratory
+experiments with dynamos are made.",1402.6557v1
+2014-07-08,Linear and nonlinear evolution of current-carrying highly magnetized jets,"We investigate the linear and nonlinear evolution of current-carrying jets in
+a periodic configuration by means of high resolution three-dimensional
+numerical simulations. The jets under consideration are strongly magnetized
+with a variable pitch profile and initially in equilibrium under the action of
+a force-free magnetic field. The growth of current-driven (CDI) and
+Kelvin-Helmholtz (KHI) instabilities is quantified using three selected cases
+corresponding to static, Alfvenic and super-Alfvenic jets.
+  During the early stages, we observe large-scale helical deformations of the
+jet corresponding to the growth of the initially excited CDI mode. A direct
+comparison between our simulation results and the analytical growth rates
+obtained from linear theory reveals good agreement on condition that
+high-resolution and accurate discretization algorithms are employed.
+  After the initial linear phase, the jet structure is significantly altered
+and, while slowly-moving jets show increasing helical deformations, larger
+velocity shear are violently disrupted on a few Alfven crossing time leaving a
+turbulent flow structure. Overall, kinetic and magnetic energies are quickly
+dissipated into heat and during the saturated regime the jet momentum is
+redistributed on a larger surface area with most of the jet mass travelling at
+smaller velocities. The effectiveness of this process is regulated by the onset
+of KHI instabilities taking place at the jet/ambient interface and can be held
+responsible for vigorous jet braking and entrainment.",1407.1962v1
+2014-08-04,Strong evidences for a nonextensive behavior of the rotation period in Open Clusters,"Time-dependent nonextensivity in a stellar astrophysical scenario combines
+nonextensive entropic indices $q_{K}$ derived from the modified Kawaler's
+parametrization, and $q$, obtained from rotational velocity distribution. These
+$q$'s are related through a heuristic single relation given by $q\approx
+q_{0}(1-\Delta t/q_{K})$, where $t$ is the cluster age. In a nonextensive
+scenario, these indices are quantities that measure the degree of
+nonextensivity present in the system. Recent studies reveal that the index $q$
+is correlated to the formation rate of high-energy tails present in the
+distribution of rotation velocity. On the other hand, the index $q_{K}$ is
+determined by the stellar rotation-age relationship. This depends on the
+magnetic field configuration through the expression $q_{K}=1+4aN/3$, where $a$
+and $N$ denote the saturation level of the star magnetic field and its
+topology, respectively. In the present study, we show that the connection
+$q-q_{K}$ is also consistent with 548 rotation period data for single
+main-sequence stars in 11 Open Clusters aged less than 1 Gyr. The value of
+$q_{K}\sim$ 2.5 from our unsaturated model shows that the mean magnetic field
+topology of these stars is slightly more complex than a purely radial field.
+Our results also suggest that stellar rotational braking behavior affects the
+degree of anti-correlation between $q$ and cluster age $t$. Finally, we suggest
+that stellar magnetic braking can be scaled by the entropic index $q$.",1408.0657v2
+2014-09-20,Large magnetoelectric coupling in nanoscale BiFeO$_3$ from direct electrical measurements,"We report the results of direct measurement of remanent hysteresis loops on
+nanochains of BiFeO$_3$ at room temperature under zero and $\sim$20 kOe
+magnetic field. We noticed a suppression of remanent polarization by nearly
+$\sim$40\% under the magnetic field. The powder neutron diffraction data reveal
+significant ion displacements under a magnetic field which seems to be the
+origin of the suppression of polarization. The isolated nanoparticles,
+comprising the chains, exhibit evolution of ferroelectric domains under dc
+electric field and complete 180$^o$ switching in switching-spectroscopy
+piezoresponse force microscopy. They also exhibit stronger ferromagnetism with
+nearly an order of magnitude higher saturation magnetization than that of the
+bulk sample. These results show that the nanoscale BiFeO$_3$ exhibits
+coexistence of ferroelectric and ferromagnetic order and a strong
+magnetoelectric multiferroic coupling at room temperature comparable to what
+some of the type-II multiferroics show at a very low temperature.",1409.5859v1
+2014-11-28,Crossover in the magnetic response of single-crystalline Ba$_{1-x}$K$_x$Fe$_2$As$_2$ and Lifshitz critical point evidenced by Hall effect measurements,"We report the doping evolution of magnetic susceptibility $\chi (T)$ and Hall
+coefficient $R_H$ in high quality Ba$_{1-x}$K$_x$Fe$_2$As$_2$ ($0.13 \leq x
+\leq 1$) single crystals. It is found that the normal-state magnetic
+susceptibility of Ba$_{1-x}$K$_x$Fe$_2$As$_2$ compounds undergoes a crossover
+from linear-$T$ dependence in the undoped and underdoped samples into
+KFe$_2$As$_2$-type magnetic response in the overdoped samples with increasing K
+content. Hall coefficient $R_H$ of underdoped sample $x$=0.22 shows a rapid
+increase above spin-density-wave transition temperature $T_{SDW}$. Below
+$T_{SDW}$, it increases slowly. $R_H$ of optimally doped and slightly overdoped
+samples ($0.34 \leq x \leq 0.65$) shows relative weak temperature dependence
+and saturation tendency below 150 K. However, $R_H$ of K heavily overdoped
+samples ($0.80 \leq x \leq 1$) increases rapidly below 150 K. Meanwhile, Hall
+angle $cot \theta _H$ displays a concave temperature dependence within the
+doping range $0.22 \leq x \leq 0.55$, whereas it changes to a convex
+temperature dependence within the doping range $0.65 \leq x \leq 1$. The
+dramatic change coincides with Lifshitz transition occurred around the critical
+doping $x$=0.80, where ARPES measurements had confirmed that electron pocket
+disappears with excess hole doping in Ba$_{1-x}$K$_x$Fe$_2$As$_2$ system. It is
+suggested that the characteristic temperature $T$* at around $120 \sim 150$ K
+observed in susceptibility and Hall coefficient, as well as previously reported
+resistivity data, may indicate an incoherence-coherence crossover in
+Ba$_{1-x}$K$_x$Fe$_2$As$_2$ system.",1411.7906v1
+2014-12-17,Chromospheric diagnosis with Ca II lines: forward modeling in forward scattering (I),"This paper shows the first synthetic tomography of the quiet solar
+chromosphere formed by spatial maps of scattering polarization. It has been
+calculated for the CaII 8498, 8542 and 3934 A lines by solving the NLTE
+(non-local thermodynamical equilibrium) RT (radiative transfer) problem of the
+second kind in a 3D atmosphere model obtained from realistic MHD
+(magneto-hydrodynamical) simulations. Maps of circular polarization were
+calculated neglecting atomic polarization. Our investigation focuses on the
+linear polarization signals induced by kinematics, radiation field anisotropy
+and Hanle effect in forward-scattering geometry. Thus, instead of considering
+slit profiles at the limb as normally done in the study of the second solar
+spectrum, we synthetize and analyze spatial maps of polarization at disk
+center. It allows us to understand the spatial signatures of dynamics and
+magnetic field in the linear polarization for discriminating them
+observationally. Our results suggest new ideas for chromospheric diagnosis that
+will be developed throughout a serie of papers. In particular, Hanle Polarity
+Inversion Lines and dynamic Hanle diagrams are two concepts introduced in the
+present work. We find that chromospheric dynamics and magnetic field topology
+create spatial fingerprints in the polarization maps that trace the dynamic
+situation of the plasma and the magnetic field. Based on such spatial features
+we reconstruct the magnetic field intensity in the middle chromosphere along
+grooves of null linear polarization. We finally address the problems of
+diagnosing Hanle saturation and kinematic amplification of scattering signals
+using Hanle diagrams.",1412.5386v1
+2015-11-23,On the Grain-Modified Magnetic Diffusivities in Protoplanetary Disks,"Weakly ionized protoplanetary disks (PPDs) are subject to
+non-ideal-magnetohydrodynamic (MHD) effects including Ohmic resistivity, the
+Hall effect and ambipolar diffusion (AD), and the resulting magnetic
+diffusivities ($\eta_O, \eta_H$ and $\eta_A$) largely control the disk gas
+dynamics. The presence of grains not only strongly reduces disk ionization
+fraction, but also modify the scalings of $\eta_H$ and $\eta_A$ with magnetic
+field strength. We derive analytically asymptotic expressions of $\eta_H$ and
+$\eta_A$ in both strong and weak field limits and show that towards strong
+field, $\eta_H$ can change sign (at a threshold field strength $B_{\rm th}$),
+mimicking a flip of field polarity, and AD is substantially reduced. Applying
+to PPDs, we find that when small $\sim0.1$ ($0.01$)$\mu$m grains are
+sufficiently abundant [mass ratio $\sim0.01$ ($10^{-4}$)], $\eta_H$ can change
+sign up to $\sim2-3$ scale heights above midplane at modest field strength
+(plasma $\beta\sim100$) over a wide range of disk radii. Reduction of AD is
+also substantial towards the AD dominated outer disk and may activate the
+magneto-rotational instability. We further perform local non-ideal MHD
+simulations of the inner disk (within 10 AU) and show that with sufficiently
+abundant small grains, magnetic field amplification due to the Hall-shear
+instability saturates at very low level near the threshold field strength
+$B_{\rm th}$. Together with previous studies, we conclude by discussing the
+grain-abundance-dependent phenomenology of PPD gas dynamics.",1511.07199v1
+2015-12-15,"Half-metallic, Co-based quaternary Heuslers for spintronics: defect- and pressure-induced transitions and properties","Heusler compounds offer potential as spintronic devices due to their
+spin-polarization and half-metallicity properties, where electron spin-majority
+(minority) manifold exhibits states (band gap) at the electronic chemical
+potential, yielding full spin-polarization in a single manifold. Yet, Heuslers
+often exhibit intrinsic disorder that degrades its half-metallicity and
+spin-polarization. Using density-functional theory, we analyze the electronic
+and magnetic properties of equiatomic Heusler ($L$2$_{1}$) CoMnCrAl and
+CoFeCrGe alloys for effects of hydrostatic pressure and intrinsic disorder
+(thermal antisites, binary swaps, and vacancies). Under pressure, CoMnCrAl
+undergoes a metallic transition, while half-metallicity in CoFeCrGe is retained
+for a limited range. Antisite disorder between Co-Al pairs in CoMnCrAl and
+Co-Ge pairs in CoFeCrGe is energetically the most favored, and retain
+half-metallic character in Co-excess samples. However, Co-deficient samples
+undergo a transition from half-metallic to metallic, with a discontinuity in
+the saturation magnetization. For binary swaps, configurations that compete
+with the ground state are identified and show no loss of half-metallicity;
+however, the minority-spin bandgap and magnetic moments vary depending on the
+atoms swapped. For single binary swaps, there is a significant energy cost in
+CoMnCrAl but with no loss of half metallicity. Although a few configurations in
+CoFeCrGe energetically compete with the ground statei, however the
+minority-spin bandgap and magnetic moments vary depending on the atoms swapped.
+These informations should help in controlling these potential spintronic
+materials.",1512.04805v2
+2016-01-17,Resistivity plateau and extremely large magnetoresistance in NbAs2 and TaAs2,"In topological insulators (TIs), metallic surface conductance saturates the
+insulating bulk resistance with de- creasing temperature, resulting in
+resistivity plateau at low temperatures as a transport signature originating
+from metallic surface modes protected by time reversal symmetry (TRS). Such
+characteristic has been found in several materials including Bi2Te2Se, SmB6
+etc. Recently, similar behavior has been observed in metallic com- pound LaSb,
+accompanying an extremely large magetoresistance (XMR). Shubnikov-de Hass (SdH)
+oscillation at low temperatures further confirms the metallic behavior of
+plateau region under magnetic fields. LaSb[1] has been proposed by the authors
+as a possible topological semimetal (TSM), while negative magnetoresistance is
+absent at this moment. Here, high quality single crystals of NbAs2/TaAs2 with
+inversion symmetry have been grown and the resistivity under magnetic field is
+systematically investigated. Both of them exhibit metallic behavior under zero
+magnetic field, and a metal-to-insulator transition occurs when a nonzero
+magnetic field is applied, resulting in XMR (1.0*105% for NbAs2 and 7.3*105%
+for TaAs2 at 2.5 K & 14 T). With tempera- ture decreased, a resistivity plateau
+emerges after the insulator-like regime and SdH oscillation has also been
+observed in NbAs2 and TaAs2.",1601.04239v1
+2016-07-20,Spatially inhomogeneous electron state deep in the extreme quantum limit of strontium titanate,"When an electronic system is subjected to a sufficiently strong magnetic
+field that the cyclotron energy is much larger than the Fermi energy, the
+system enters the ""extreme quantum limit"" (EQL) and becomes susceptible to a
+number of instabilities. Bringing a three-dimensional electronic system deeply
+into the EQL can be difficult, however, since it requires a small Fermi energy,
+large magnetic field, and low disorder. Here we present an experimental study
+of the EQL in lightly-doped single crystals of strontium titanate, which remain
+good bulk conductors down to very low temperatures and high magnetic fields.
+Our experiments probe deeply into the regime where theory has long predicted
+electron-electron interactions to drive the system into a charge density wave
+or Wigner crystal state. A number of interesting features arise in the
+transport in this regime, including a striking re-entrant nonlinearity in the
+current-voltage characteristics and a saturation of the quantum-limiting field
+at low carrier density. We discuss these features in the context of possible
+correlated electron states, and present an alternative picture based on
+magnetic-field induced puddling of electrons.",1607.06085v1
+2016-09-21,Age dependence of wind properties for solar type stars: a 3d study,"Young and rapidly rotating stars are known for intense, dynamo generated
+magnetic fields. Spectropolarimetric observations of those stars in precisely
+aged clusters are key input for gyrochronology and magnetochronology. We use
+ZDI maps of several young K-type stars of similar mass and radius but with
+various ages and rotational periods, to perform 3D numerical MHD simulations of
+their coronae and follow the evolution of their magnetic properties with age.
+Those simulations yield the coronal structure as well as the instant torque
+exerted by the magnetized, rotating wind on the star. As stars get older, we
+find that the angular momentum loss decreases with $\Omega^3$, which is the
+reason for the convergence on the Skumanich law. For the youngest stars of our
+sample, the angular momentum loss show signs of saturation around
+$8\Omega_{\odot}$, which is a common value used in spin evolution models for
+K-type stars. We compare these results to semi-analytical models and existing
+braking laws. We observe a complex wind speed distribution for the youngest
+stars with slow, intermediate and fast wind components, which are the result of
+the interaction with intense and non axisymmetric magnetic fields.
+Consequently, in our simulations, the stellar wind structure in the equatorial
+plane of young stars varies significantly from a solar configuration,
+delivering insight about the past of the solar system interplanetary medium.",1609.06602v2
+2016-10-07,On the Fast Magnetic Rotator Regime of Stellar Winds,"Aims: We study the acceleration of the stellar winds of rapidly rotating low
+mass stars and the transition between the slow magnetic rotator and fast
+magnetic rotator regimes. We aim to understand the properties of stellar winds
+in the fast magnetic rotator regime and the effects of magneto-centrifugal
+forces on wind speeds and mass loss rates.
+  Methods: We extend the solar wind model of Johnstone et al. (2015b) to 1D
+magnetohydrodynamic (MHD) simulations of the winds of rotating stars. We test
+two assumptions for how to scale the wind temperature to other stars and assume
+the mass loss rate scales as Mdot ~ Rstar^2 OmegaStar^1.33 Mstar^-3.36, in the
+unsaturated regime, as estimated by Johnstone et al. (2015a).
+  Results: For 1.0 Msun stars, the winds can be accelerated to several thousand
+km/s, and the effects of magneto-centrifugal forces are much weaker for lower
+mass stars. We find that the different assumptions for how to scale the wind
+temperature to other stars lead to significantly different mass loss rates for
+the rapid rotators. If we assume a constant temperature, the mass loss rates of
+solar mass stars do not saturate at rapid rotation, which we show to be
+inconsistent with observed rotational evolution. If we assume the wind
+temperatures scale positively with rotation, the mass loss rates are only
+influenced significantly at rotation rates above 75 OmegaSun. We suggest that
+models with increasing wind speed for more rapid rotators are preferable to
+those that assume a constant wind speed. If this conclusion is confirmed by
+more sophisticated wind modelling. it might provide an interesting
+observational constraint on the properties of stellar winds.",1610.02248v1
+2017-01-13,Nonmagnetic impurities and roughness effects on the finite temperature magnetic properties of core-shell spherical nanoparticles,"Being inspired by a recent study [V. Dimitriadis et al. Phys. Rev. B
+\textbf{92}, 064420 (2015)], we study the finite temperature magnetic
+properties of the spherical nanoparticles with core-shell structure including
+quenched (i) surface and (ii) interface nonmagnetic impurities (static holes)
+as well as (iii) roughened interface effects. The particle core is composed of
+ferromagnetic spins, and it is surrounded by a ferromagnetic shell. By means of
+Monte Carlo simulation based on an improved Metropolis algorithm, we implement
+the nanoparticles using classical Heisenberg Hamiltonians. Particular attention
+has also been devoted to elucidate the effects of the particle size on the
+thermal and magnetic phase transition features of these systems. For
+nanoparticles with imperfect surface layers, it is found that bigger particles
+exhibit lower compensation point which decreases gradually with increasing
+amount of vacancies, and vanishes at a critical value. In view of nanoparticles
+with diluted interface, our Monte Carlo simulation results suggest that there
+exists a region in the disorder spectrum where compensation temperature
+linearly decreases with decreasing dilution parameter. For nanoparticles with
+roughened interface, it is observed that the degree of roughness does not play
+any significant role on the variation of both the compensation point and
+critical temperature. However, the low temperature saturation magnetizations of
+the core and shell interface regions sensitively depend on the roughness
+parameter.",1701.03575v1
+2017-03-19,"Magnetic properties of Sn-substituted Ni-Zn ferrite:synthesized from nano-sized powders of NiO, ZnO, Fe2O3 and SnO2","A series of Ni0.6-x/2Zn0.4-x/2SnxFe2O4 (x = 0.0, 0.05, 0.1, 0.15, 0.2 and
+0.3) (NZSFO) ferrite composites have been synthesized from nano powders using
+standard solid state reaction technique. The spinel cubic structure of the
+investigated samples has been observed by the X-ray diffraction (XRD). The
+magnetic properties such as saturation magnetization (Ms), remanent
+magnetization (Mr), coercive field (Hc) and Bohr magneton (B) are calculated
+from the hysteresis loops. The value of Ms is found to decrease with increasing
+Sn content in the samples. This change has been successfully explained by the
+variation of A-B interaction strength due to Sn substitution in different
+sites. The compositional stability and quality of the prepared ferrite
+composites have also been endorsed by the fairly constant initial permeability
+(/) over a wide range of frequency region. The decreasing trend of / with
+increasing Sn content has been observed. Curie temperature (TC) has found to
+increase with the increase in Sn content. Wide spread frequency utility zone
+indicates that the NZSFO can be considered as a good candidate for use in
+broadband pulse transformer and wide band read-write heads for video recording.
+The abnormal behavior for x = 0.05 has been explained with existing theory.",1703.06385v1
+2017-09-20,Electron Heating and Saturation of Self-regulating Magnetorotational Instability in Protoplanetary Disks,"Magnetorotational instability (MRI) has a potential to generate the vigorous
+turbulence in protoplanetary disks, although its turbulence strength and
+accretion stress remains debatable because of the uncertainty of MRI with low
+ionization fraction. We focus on the heating of electrons by strong electric
+fields which amplifies nonideal magnetohydrodynamic effects. The heated
+electrons frequently collide with and stick to dust grains, which in turn
+decreases the ionization fraction and is expected to weaken the turbulent
+motion driven by MRI. In order to quantitatively investigate the nonlinear
+evolution of MRI including the electron heating, we perform
+magnetohydrodynamical simulation with the unstratified shearing box. We
+introduce a simple analytic resistivity model depending on the current density
+by mimicking resistivity given by the calculation of ionization. Our simulation
+confirms that the electron heating suppresses magnetic turbulence when the
+electron heating occurs with low current density. We find a clear correlation
+between magnetic stress and its current density, which means that the magnetic
+stress is proportional to the squared current density. When the turbulent
+motion is completely suppressed, laminar accretion flow is caused by ordered
+magnetic field. We give an analytical description of the laminar state by using
+a solution of linear perturbation equations with resistivity. We also propose a
+formula that successfully predicts the accretion stress in the presence of the
+electron heating.",1709.07026v1
+2017-10-06,Investigation of the interfacial Dzyaloshinskii-Moriya interaction sign in Ir/Co2FeAl systems by Brillouin light scattering,"Co2FeAl (CFA) ultrathin films, of various thicknesses (0.9 nm<tCFA<1.8 nm),
+have been grown by sputtering on Si substrates, using Ir as a buffer layer. The
+magnetic properties of the structures have been studied by vibrating sample
+magnetometry (VSM), miscrostrip ferromagnetic resonance (MS-FMR) and Brillouin
+light scattering (BLS) in the Damon-Eshbach geometry. VSM characterizations
+show that films are mostly in-plane magnetized and the perpendicular saturating
+field increases with decreasing CFA thickness suggesting the existence of
+interface anisotropy. The presence of magnetic dead layers of 0.44 nm has been
+detected by VSM. The MS-FMR with perpendicular applied magnetic field has been
+used to determine the gyromagnetic factor. The BLS measurements reveal a
+pronounced nonreciprocal spin waves propagation, due to the interfacial
+Dzyaloshinskii-Moriya interaction (DMI) induced by Ir interface with CFA, which
+increases with decreasing CFA thickness. The DMI sign has been found to be the
+same (negative) as that of Pt/Co, in contrast to the ab-initio calculation on
+Ir/Co. The thickness dependence of the effective DMI constant shows the
+existence of two regimes similarly to that of the perpendicular anisotropy
+constant. The DMI constant Ds was estimated to be -0.37 pJ/m for the thickest
+samples where a linear thickness dependence of the effective DMI constant has
+been observed.",1710.02433v1
+2018-04-26,Large voltage tuning of Dzyaloshinskii-Moriya Interaction: a route towards dynamic control of skyrmion chirality,"Electric control of magnetism is a prerequisite for efficient and low power
+spintronic devices. More specifically, in heavy metal/ ferromagnet/ insulator
+heterostructures, voltage gating has been shown to locally and dynamically tune
+magnetic properties like interface anisotropy and saturation magnetization.
+However, its effect on interfacial Dzyaloshinskii-Moriya Interaction (DMI),
+which is crucial for the stability of magnetic skyrmions, has been challenging
+to achieve and has not been reported yet for ultrathin films. Here, we
+demonstrate 130% variation of DMI with electric field in Ta/FeCoB/TaOx
+trilayers through Brillouin Light Spectroscopy (BLS). Using polar-
+Magneto-Optical-Kerr-Effect microscopy, we further show a monotonic variation
+of DMI and skyrmionic bubble size with electric field, with an unprecedented
+efficiency. We anticipate through our observations that a sign reversal of DMI
+with electric field is possible, leading to a chirality switch. This dynamic
+manipulation of DMI establishes an additional degree of control to engineer
+programmable skyrmion based memory or logic devices.",1804.09955v2
+2018-05-08,Analytical treatment for the development of electromagnetic cascades in intense magnetic fields,"In a strong magnetic field, a high-energy photon can be absorbed and then
+produce an electron-positron pair. The produced electron/positron will in turn
+radiate a high-energy photon via synchrotron radiation, which then initiates a
+cascade. We built a one-dimensional Monte-Carlo code to study the development
+of the cascade especially after it reaches the saturated status, when almost
+all the energy of the primary particles transfers to the photons. The photon
+spectrum in this status has a cut-off due to the absorption by magnetic fields,
+which is much sharper than the exponential one. Below the cut-off, the spectral
+energy distribution (SED) manifest itself as a broken power-law with a spectral
+index of $0.5$ and $0.125$, respectively, below and above the broken energy.
+The SED can be fitted by a simple analytical function, which is solely
+determined by the product of the cascade scale $R$ and the magnetic field
+perpendicular to the motion of the particle B_{\perp}, with an accuracy better
+than 96\%. The similarity of the spectrum to that from the cascade in an
+isotropic black-body photon field is also studied.",1805.03040v2
+2018-07-31,Nature of magnetism and transport in BxCyNz thin films: The intriguing role of nitrogen defects in the electronic structure,"Boron carbonitride (BxCyNz) represents an interesting family of materials
+containing all light elements and two dimensional graphene like hybrid layers.
+Although rich literature exists on this peculiar material in chemically
+processed form, there are relatively fewer reports on device application-worthy
+thin film form. This form also offers a natural platform for basic studies on
+important aspects such as magnetism and transport, which have attracted
+attention in the context of ferromagnetism in doped and defect carbon systems.
+Thus, in this work we have grown thin films of this compound using Pulsed Laser
+Deposition (PLD) method, and investigated their magnetic and transport
+properties in their entirety along with the detailed electronic structure using
+various spectroscopic techniques like X-ray photoelectron spectroscopy (XPS),
+Valence Band Spectroscopy (VBS) and X-ray absorption near edge spectroscopy
+(XANES). In depth analysis of the typical role of dopants and defects,
+especially the prevalent nitrogen defects, is elucidated using Density
+Functional Theory (DFT) calculations to understand the experimental
+observations. A dramatic crossover in the transport mechanism of charge
+carriers is observed in this system with the change in doping level of specific
+nitrogen defects. A robust and high saturation magnetization is achieved in BCN
+films which is higher by almost hundred times as compared to that in similarly
+grown undoped carbon film. An anomalous transition and increase in coercive
+field is also observed at low temperature. A careful analysis brings out the
+intriguing role of specific nitrogen defects in defining the peculiar nature
+and concentration dependence of the physical properties of this system.",1807.11667v1
+2018-08-02,The Steady Growth of the High-Energy Spectral Cutoff in Relativistic Magnetic Reconnection,"Magnetic reconnection is invoked as an efficient particle accelerator in a
+variety of astrophysical sources of non-thermal high-energy radiation. With
+large-scale two-dimensional particle-in-cell simulations of relativistic
+reconnection (i.e., with magnetization $\sigma\gg1$) in pair plasmas, we study
+the long-term evolution of the power-law slope and high-energy cutoff of the
+spectrum of accelerated particles. We find that the high-energy spectral cutoff
+does not saturate at $\gamma_{\rm cut}\sim 4\sigma$, as claimed by earlier
+studies, but it steadily grows with time as long as the reconnection process
+stays active. At late times, the cutoff scales approximately as $\gamma_{\rm
+cut}\propto \sqrt{t}$, regardless of the flow magnetization and initial
+temperature. We show that the particles dominating the high-energy spectral
+cutoff reside in plasmoids, and in particular in a strongly magnetised ring
+around the plasmoid core. The growth of their energy is driven by the increase
+in the local field strength, coupled with the conservation of the first
+adiabatic invariant. We also find that the power-law slope of the spectrum
+($p=-{\rm d}\log N/{\rm d}\log \gamma$) evolves with time. For
+$\sigma\gtrsim10$, the spectrum is hard at early times ($p\lesssim 2$), but it
+tends to asymptote to $p\sim 2$; the steepening of the power-law slope allows
+the spectral cutoff to extend to higher and higher energies, without violating
+the fixed energy budget of the system. Our results demonstrate that
+relativistic reconnection is a viable candidate for accelerating the
+high-energy particles emitting in relativistic astrophysical sources.",1808.00966v2
+2018-08-03,Creation of Magnetic Skyrmion Bubble Lattices by Ultrafast Laser in Ultrathin Films,"Magnetic skyrmions are topologically nontrivial spin textures which hold
+great promise as stable information carriers in spintronic devices at the
+nanoscale. One of the major challenges for developing novel skyrmion-based
+memory and logic devices is fast and controlled creation of magnetic skyrmions
+at ambient conditions. Here we demonstrate the single ultrafast (35-fs) laser
+pulse-induced generation of skyrmion bubbles and skyrmion bubble lattices from
+a ferromagnetic state in sputtered ultrathin magnetic films at room
+temperature. The skyrmion bubble density increases with the laser fluence in a
+controlled way, and it finally becomes saturated, forming disordered hexagonal
+lattices. Moreover, we present that the skyrmion bubble lattice configuration
+leads to enhanced topological stability as compared to isolated skyrmions,
+suggesting its promising use in data storage. Our findings shed light on the
+optical approach to the skyrmion bubble lattice in commonly accessible
+materials, paving the road toward the emerging skyrmion-based memory and
+synaptic devices.",1808.01385v2
+2018-08-17,Temperature Dependence of Magnetic Properties of an 18-nm-thick YIG Film Grown by Liquid Phase Epitaxy: Effect of a Pt Overlayer,"Liquid phase epitaxy of an 18 nm thick Yttrium Iron garnet (YIG) film is
+achieved. Its magnetic properties are investigated in the 100 -- 400 K
+temperature range, as well as the influence of a 3 nm thick Pt overlayer on
+them. The saturation magnetization and the magnetocrystalline cubic anisotropy
+of the bare YIG film behave similarly to bulk YIG. A damping parameter of only
+a few $10^{-4}$ is measured, together with a low inhomogeneous contribution to
+the ferromagnetic resonance linewidth. The magnetic relaxation increases upon
+decreasing temperature, which can be partly ascribed to impurity relaxation
+mechanisms. While it does not change its cubic anisotropy, the Pt capping
+strongly affects the uniaxial perpendicular anisotropy of the YIG film, in
+particular at low temperatures. The interfacial coupling in the YIG/Pt
+heterostructure is also revealed by an increase of the linewidth, which
+substantially grows by lowering the temperature.",1808.05785v2
+2018-09-10,The Effect of Nickel Substitution on Magnetism in the Layered van der Waals Ferromagnet Fe$_3$GeTe$_2$,"We have grown a series of nickel substituted single crystals of the layered
+ferromagnet (FM) Fe$_3$GeTe$_2$. The large single crystalline samples of
+(Fe$_{1-x}$Ni$_x$)$_3$GeTe$_2$ with $x = 0-0.84$ were characterized with single
+crystal X-ray diffraction, magnetic susceptibility, electrical resistance and
+muon spin spectroscopy. We find Fe can be continuously substituted with Ni with
+only minor structural variation. In addition, FM order is suppressed from
+$T_\mathrm{C}=212$~K for $x=0$ down to $T_\mathrm{C}=50$~K for $x=0.3$, which
+is accompanied with a strong suppression of saturated and effective moment, and
+Curie-Weiss temperature. Beyond $x=0.3$, the FM order is continuously smeared
+into a FM cluster glass phase, with a nearly full magnetic volume fraction. We
+attribute the observed change in the nature of magnetic order to the
+intrinsically disordered structure of Fe$_3$GeTe$_2$ and subsequent dilution
+effects from the Ni substitution.",1809.03429v2
+2018-10-17,"Investigation of the structural, electronic, transport and magnetic properties of Co$_2$FeGa Heusler alloy nanoparticles","We report the structural, transport, electronic, and magnetic properties of
+Co$_2$FeGa Heusler alloy nanoparticles. The Rietveld refinements of x-ray
+diffraction (XRD) data with the space group Fm$\bar {3}$m clearly demonstrates
+that the nanoparticles are of single phase. The particle size (D) decreases
+with increasing the SiO$_2$ concentration. The Bragg peak positions and the
+inter-planer spacing extracted from high-resolution transmission electron
+microscopy image and selected area electron diffraction are in well agreement
+with data obtained from XRD. The coercivity initially increases from 127~Oe to
+208~Oe between D = 8.5~nm and 12.5~nm, following the D$^{-3/2}$ dependence and
+then decreases with further increasing D up to 21.5~nm with a D$^{-1}$
+dependence, indicating the transition from single domain to multidomain regime.
+The effective magnetic anisotropic constant behaves similarly as coercivity,
+which confirms this transition. A complex scattering mechanisms have been
+fitted to explain the electronic transport properties of these nanoparticles.
+In addition we have studied core-level and valence band spectra using
+photoemission spectroscopy, which confirm the hybridization between $d$ states
+of Co/Fe. Further nanoparticle samples synthesized by co-precipitation method
+show higher saturation magnetization. The presence of Raman active modes can be
+associated with the high chemical ordering, which motivates for detailed
+temperature dependent structural investigation using synchrotron radiation and
+neutron sources.",1810.07660v1
+2018-11-02,Electron Strahl and Halo Formation in the Solar Wind,"We propose a kinetic model describing the formation of the strahl and halo
+electron populations in the solar wind. We demonstrate that the suprathermal
+electrons propagating from the sun along the Parker-spiral magnetic field lines
+are progressively focused into a narrow strahl at heliospheric distances
+$r\lesssim 1$ AU, while at $r\gtrsim 1$ AU the width of the strahl saturates
+due to Coulomb collisions and becomes independent of the distance. Our theory
+of the strahl broadening does not contain free parameters and it agrees with
+the Wind observations at 1 AU to within $15-20\%$. This indicates that Coulomb
+scattering, rather than anomalous turbulent diffusion, plays a dominant role in
+strahl formation in these observations. We further propose that the nearly
+isotropic halo electron population may be composed of electrons that ran away
+from the sun as an electron strahl, but later ended up on magnetic field lines
+leading them back to the sun. Through the effects of magnetic defocusing and
+Coulomb pitch-angle scattering, a narrow source distribution at large
+heliocentric distances appears nearly isotropic at distances $\sim$1 AU. The
+halo electrons are, therefore, not produced locally; rather, they are the fast
+electrons trapped by magnetic field lines on global heliospheric scales. At the
+electron energies $K \lesssim 200\,\, {\rm eV}$, our theory is quite
+insensitive to the particular mechanism that produces a population of
+sunward-streaming suprathermal particles. At larger energies, however, our
+theory indicates that the scattering provided by Coulomb collisions alone is
+not sufficient to isotropize a narrow sunward-propagating electron beam.",1811.01098v1
+2019-01-07,Maser and other instabilities in a weakly magnetized relativistic plasma: Theory and the astrophysical relevance of the maser,"A sufficient condition for maser instability in a weakly magnetized
+relativistic plasma with an isotropic particle distribution function is given.
+The maser growth rates and polarizations are computed starting from the exact
+dielectric permittivity tensor of a magnetized plasma. For very weak magnetic
+fields, our results confirm the approximate validity of the 'standard maser
+theory', which is based on the Einstein coefficients method, with one
+significant exception. For inclined propagation and realistic (small but
+finite) field, the growth rates of the two (nearly circular) polarizations
+differ significantly, while the standard theory predicts two (nearly circular)
+polarizations with similar growth rates. We show that this deviation is due to
+circularly polarized synchrotron emission, which is neglected in the standard
+theory.
+  The maser is shown to grow slower than Langmuir waves. Nevertheless,
+significant generation of EM waves is seen in (highly simplified) direct
+numerical simulations. We study the nonlinear saturation of the maser
+instability and find that it offers a mechanism for the conversion of a
+significant fraction of the plasma energy into radio waves. We briefly discuss
+the conditions under which the maser instability may operate in astrophysical
+sources, and provide rough estimates that may be used as a guidance when
+studying particular astrophysical sources/phenomena.",1901.01700v1
+2019-01-08,Ferromagnetic ordering along the hard axis in the Kondo lattice YbIr3Ge7,"Ferromagnetic Kondo lattice compounds are far less common than their
+antiferromagnetic analogs. In this work, we report the discovery of a new
+ferromagnetic Kondo lattice compound, YbIr3Ge7. Like almost all ferromagnetic
+Kondo lattice systems, YbIr3Ge7 shows magnetic order with moments aligned
+orthogonal to the crystal electric field (CEF) easy axis. YbIr3Ge7 is unique in
+that it is the only member of this class of compounds that crystallizes in a
+rhombohedral structure with a trigonal point symmetry of the magnetic site, and
+it lacks broken inversion symmetry at the local moment site. AC magnetic
+susceptibility, magnetization, and specific heat measurements show that
+YbIr3Ge7 has a Kondo temperature TK = 14 K and a Curie temperature TC = 2.4 K.
+Ferromagnetic order occurs along the crystallographic [100] hard CEF axis
+despite the large CEF anisotropy of the ground state Kramers doublet with a
+saturation moment along [001] almost four times larger than the one along
+[100]. This implies that a mechanism which considers the anisotropy in the
+exchange interaction to explain the hard axis ordering is unlikely. On the
+other hand, the broad second-order phase transition at TC favors a
+fluctuation-induced mechanism.",1901.02489v1
+2019-03-25,Octahedral tilting and emergence of ferrimagnetism in cobalt-ruthenium based double perovskites,"Rare earth based cobalt-ruthenium double perovskites A$_2$CoRuO$_6$ (A = La,
+Pr, Nd and Sm) were synthesized and investigated for their structural and
+magnetic properties. All the compounds crystallize in the monoclinic $P2_1/n$
+structure with the indication of antisite disorder between Co and Ru sites.
+While, La compound is already reported to have an antiferromagnetic state below
+27 K, the Pr, Nd and Sm systems are found to be ferrimagnetic below $T_c$ = 46,
+55 and 78 K respectively. Field dependent magnetization data indicate prominent
+hysteresis loop below $T_c$ in the samples containing magnetic rare-earth ions,
+however magnetization does not saturate even at the highest applied fields. Our
+structural analysis indicates strong distortion in the Co-O-Ru bond angle, as
+La$^{3+}$ is replaced by smaller rare-earth ions such as Pr$^{3+}$, Nd$^{3+}$
+and Sm$^{3+}$. The observed ferrimagnetism is possibly associated with the
+enhanced antiferromagnetic superexchange interaction in the Co-O-Ru pathway due
+to bond bending. The Pr, Nd and Sm samples also show small magnetocaloric
+effect with Nd sample showing highest value of magnitude $\sim$ 3
+Jkg$^{-1}$K$^{-1}$ at 50 kOe. The change in entropy below 20 K is found to be
+positive in the Sm sample as compared to the negative value in the Nd
+counterpart.",1903.10271v1
+2019-07-08,Bloch-to-Néel domain wall transition evinced through morphology of magnetic bubble expansion in Ta/CoFeB/MgO layers,"Ta/CoFeB/MgO trilayers with perpendicular magnetic anisotropy are often
+characterised by vanishing or modest values of interfacial
+Dzyaloshinskii-Moriya interaction (DMI), which results in purely Bloch or mixed
+Bloch-N\'eel domain walls (DWs). Here we investigate the creep evolution of the
+overall magnetic bubble morphology in these systems under the combined presence
+of in-plane and out-of-plane magnetic fields and we show that He$^+$ ion
+irradiation induces a transition of the internal DW structure towards a fully
+N\'eel spin texture. This transition can be correlated to a simultaneous
+increase in DMI strength and reduction in saturation magnetisation -- which are
+a direct consequence of the effects of ion irradiation on the bottom and top
+CoFeB interfaces, respectively. The threshold irradiation dose above which DWs
+acquire a pure N\'eel character is experimentally found to be between 12
+$\times$ 10$^{18}$ He$^+$/m$^2$ and 16 $\times$ 10$^{18}$ He$^+$/m$^2$,
+matching estimations from the one dimensional DW model based on material
+parameters. Our results indicate that evaluating the global bubble shape during
+its expansion can be an effective tool to sense the internal bubble DW
+structure. Furthermore, we show that ion irradiation can be used to achieve
+post-growth engineering of a desired DW spin texture.",1907.03708v1
+2019-09-05,On the Survival of Cool Clouds in the Circum-Galactic Medium,"We explore the survival of cool clouds in multi-phase circum-galactic media.
+We revisit the ""cloud crushing problem"" in a large survey of simulations
+including radiative cooling, self-shielding, self-gravity, magnetic fields, and
+anisotropic Braginskii conduction and viscosity (with saturation). We explore a
+wide range of parameters including cloud size, velocity, ambient temperature
+and density, as well as a variety of magnetic field configurations and cloud
+turbulence. We find that realistic magnetic fields and turbulence have weaker
+effects on cloud survival; the most important physics is radiative cooling and
+conduction. Self-gravity and self-shielding are important for clouds which are
+initially Jeans-unstable, but largely irrelevant otherwise.
+Non-self-gravitating, realistically magnetized clouds separate into four
+regimes: (1) At low column densities, clouds evaporate rapidly via conduction.
+(2) A ""failed pressure confinement"" regime, where the ambient hot gas cools too
+rapidly to provide pressure confinement for the cloud. (3) An ""infinitely
+long-lived"" regime, in which the cloud lifetime becomes longer than the cooling
+time of gas swept up in the leading bow shock, so the cloud begins to accrete
+and grow. (4) A ""classical cloud destruction"" regime, where clouds are
+eventually destroyed by instabilities. In the final regime, the cloud lifetime
+can exceed the naive cloud-crushing time owing to conduction-induced
+compression. However, small and/or slow-moving clouds can also evaporate more
+rapidly than the cloud-crushing time. We develop simple analytic models that
+explain the simulated cloud destruction times in this regime.",1909.02632v2
+2019-09-11,Giant pressure-enhancement of multiferroicity in CuBr2,"Type-II multiferroic materials, in which ferroelectric polarization is
+induced by inversion non-symmetric magnetic order, promise new and highly
+efficient multifunctional applications based on the mutual control of magnetic
+and electric properties. Although this phenomenon has to date been limited to
+low temperatures, here we report a giant pressure-dependence of the
+multiferroic critical temperature in CuBr$_2$. At 4.5 GPa, $T_\mathrm{C}$ is
+enhanced from 73.5 to 162 K, to our knowledge the highest value yet reported
+for a non-oxide type-II multiferroic. This growth shows no sign of saturating
+and the dielectric loss remains small under these high pressures. We establish
+the structure under pressure and demonstrate a 60\% increase in the two-magnon
+Raman energy scale up to 3.6 GPa. First-principles structural and magnetic
+energy calculations provide a quantitative explanation in terms of dramatically
+pressure-enhanced interactions between CuBr$_2$ chains. These large,
+pressure-tuned magnetic interactions motivate structural control in cuprous
+halides as a route to applied high-temperature multiferroicity.",1909.04989v2
+2019-11-19,Efficient Numerical Modeling of the Magnetization Loss on a Helically Wound Superconducting Tape in a Ramped Magnetic Field,"We investigate theoretically the dependence of magnetization loss of a
+helically wound superconducting tape on the round core radius $R$ and the
+helical conductor pitch in a ramped magnetic field. Using the thin-sheet
+approximation, we identify the two-dimensional equation that describes
+Faraday's law of induction on a helical tape surface in the steady state. Based
+on the obtained basic equation, we simulate numerically the current streamlines
+and the power loss $P$ per unit tape length on a helical tape. For $R \gtrsim
+w_0$ (where $w_0$ is the tape width), the simulated value of $P$ saturates
+close to the loss power $\sim(2/\pi)P_{\rm flat}$ (where $P_{\rm flat}$ is the
+loss power of a flat tape) for a loosely twisted tape. This is verified
+quantitatively by evaluating power loss analytically in the thin-filament limit
+of $w_0/R\rightarrow 0$. For $R \lesssim w_0$, upon thinning the round core,
+the helically wound tape behaves more like a cylindrical superconductor as
+verified by the formula in the cylinder limit of $w_0/R\rightarrow 2\pi$, and
+$P$ decreases further from the value for a loosely twisted tape, reaching $\sim
+(2/\pi)^2 P_{\rm flat}$.",1911.08170v1
+2019-12-06,Using the Stokes V widths of Fe I lines for diagnostics of the intrinsic solar photospheric magnetic field,"The goal of this study is to explore a novel method for the solar
+photospheric magnetic field diagnostics using Stokes V widths of different
+magnetosensitive Fe~I spectral lines. We calculate Stokes I and V profiles of
+several Fe I lines based on a one-dimensional photospheric model VAL C using
+the NICOLE radiative transfer code. These profiles are used to produce
+calibration curves linking the intrinsic magnetic field values with the widths
+of blue peaks of Stokes V profiles. The obtained calibration curves are then
+tested using the Stokes profiles calculated for more realistic photospheric
+models based on MHD models of magneto-convection. It is shown that the
+developed Stokes V widths (SVW) method can be used with various optical and
+near-infrared lines. Out of six lines considered in this study, FeI 6301 line
+appears to be the most effective: it is sensitive to fields over ~200G and does
+not show any saturation up to ~2kG. Other lines considered can also be used for
+the photospheric field diagnostics with this method, however, only in narrower
+field value ranges, typically from about 100G to 700-1000G. The developed
+method can be a useful alternative to the classical magnetic line ratio method,
+particularly when the choice of lines is limited.",1912.03340v1
+2019-12-23,Weibel instability drives large magnetic field generation in laser-driven single plume ablation,"First-principles kinetic simulations are used to investigate magnetic field
+generation processes in expanding ablated plasmas relevant to laser-driven
+foils and hohlraums. In addition to Biermann-battery-generated magnetic fields,
+strong filamentary magnetic filaments are found to grow in the corona of single
+expanding plasma plumes; such filaments are observed to dominate Biermann
+fields at sufficiently large focal radius, reaching saturation values of $\sim$
+100 T at National Ignition Facility-like drive conditions. The filamentary
+fields result from the ion Weibel instability driven by relative
+counterstreaming between the ablated ions and a sparse background population,
+which could be the result of a gas prefill in a hohlraum or laser pre-pulse.
+The ion-Weibel instability is robust with the inclusion of collisions and grows
+on a timescale of 100 ps, with a wavelength on the scale of 100-250 $\mu$m,
+over a wide range of background population densities; the instability also
+gives rise to coherent density oscillations. These results are of particular
+interest to inertial confinement fusion experiments, where such field and
+density perturbations can modify heat-transport as well as laser propagation
+and absorption.",1912.11120v1
+2019-12-27,Localized spin waves at low temperatures in a Cobalt Carbide nanocomposite,"We study magnetic, transport and thermal properties of Cobalt carbide
+nanocomposite with a mixture of Co2C and Co3C phases in 1:1 ratio, with an
+average particle diameter of 40$\pm 15$ nm. We show that the behavior of the
+nanocomposite is completely different from that of either Co3C or Co2C. We
+observed that with decreasing temperature the saturation magnetization MS(T)
+increases, however, below 100 K, there is a steep rise. A detail analysis shows
+the increase in MS(T) down to 100 K is explained via the surface spin freezing
+model. However, below 100 K the steep increase in MS(T) is explained by a
+finite size effect related to a confinement of spin waves within the nano
+particles. The measurement of heat capacity shows broad peak at 100 K along
+with presence of another anomaly at a lower temperature 43 K(=Tex). Resistance
+measurement in the nanocomposite shows metallic behavior at high T with an
+unusual anomaly appearing at Tex, which is near the T regime where MS(T) begins
+to increase steeply. A measurement of the temperature gradients across the
+sample thickness indicates an abrupt change in thermal conductivity at Tex
+which suggests a phase transition at Tex. Our results are explained in terms of
+a transformation from a magnetically coupled state with a continuous spectrum
+of spin waves into a magnetically decoupled state below 100 K with confined
+spin waves.",1912.12085v1
+2020-06-17,"Epitaxy, exfoliation, and strain-induced magnetism in rippled Heusler membranes","Single-crystalline membranes of functional materials enable the tuning of
+properties via extreme strain states; however, conventional routes for
+producing membranes require the use of sacrificial layers and chemical
+etchants, which can both damage the membrane and limit the ability to make them
+ultrathin. Here we demonstrate the epitaxial growth of the cubic Heusler
+compound GdPtSb on graphene-terminated Al$_2$O$_3$ substrates. Despite the
+presence of the graphene interlayer, the Heusler films have epitaxial registry
+to the underlying sapphire, as revealed by x-ray diffraction, reflection high
+energy electron diffraction, and transmission electron microscopy. The weak Van
+der Waals interactions of graphene enable mechanical exfoliation to yield
+free-standing GdPtSb membranes, which form ripples when transferred to a
+flexible polymer handle. Whereas unstrained GdPtSb is antiferromagnetic,
+measurements on rippled membranes show a spontaneous magnetic moment at room
+temperature, with a saturation magnetization of 5.2 bohr magneton per Gd.
+First-principles calculations show that the coupling to homogeneous strain is
+too small to induce ferromagnetism, suggesting a dominant role for strain
+gradients. Our membranes provide a novel platform for tuning the magnetic
+properties of intermetallic compounds via strain (piezomagnetixm and
+magnetostriction) and strain gradients (flexomagnetism).",2006.10100v3
+2020-06-25,Magnetic Fields in the Formation of the First Stars. I. Theory vs. Simulation,"While magnetic fields are important in contemporary star formation, their
+role in primordial star formation is unknown. Magnetic fields of order 10^-16 G
+are produced by the Biermann battery due to the curved shocks and turbulence
+associated with the infall of gas into the dark matter minihalos that are the
+sites of formation of the first stars. These fields are rapidly amplified by a
+small-scale dynamo until they saturate at or near equipartition with the
+turbulence in the central region of the gas. Analytic results are given for the
+outcome of the dynamo, including the effect of compression in the collapsing
+gas. The mass-to-flux ratio in this gas is 2-3 times the critical value,
+comparable to that in contemporary star formation. Predictions of the outcomes
+of simulations using smooth particle hydrodynamics (SPH) and grid-based
+adaptive mesh refinement (AMR) are given. Because the numerical viscosity and
+resistivity for the standard resolution of 64 cells per Jeans length are
+several orders of magnitude greater than the physical values, dynamically
+significant magnetic fields affect a much smaller fraction of the mass in
+simulations than in reality. An appendix gives an analytic treatment of
+free-fall collapse, including that in a constant density background. Another
+appendix presents a new method of estimating the numerical viscosity; results
+are given for both SPH and grid-based codes.",2006.14607v1
+2020-07-01,"Impact of V substitution on the physical properties of Ni-Zn-Co ferrites: structural, magnetic, dielectric and electrical properties","We have investigated the Vanadium- (V) substituted Ni-Zn-Co ferrites where
+the samples were prepared using solid-state reaction technique. The impact of
+V5+ substitution on the structural, magnetic, dielectric and electrical
+properties of Ni-Zn-Co ferrites has been studied. XRD analysis confirmed the
+formation of a single-phase cubic spinel structure. The lattice constants have
+been calculated both theoretically and experimentally along with other
+structural parameters such as bulk density, X-ray density and porosity. The
+FESEM images are taken to study the surface morphology. FTIR measurement is
+also performed which confirms spinel structure formation. The saturation
+magnetization (Ms), coercive field (Hc) and Bohr magneton (B) were calculated
+from the obtained M-H loops. The temperature dependent permeability is studied
+to obtain the Curie temperature. Frequency and composition dependence of
+permeability was also analyzed. Dielectric behavior and ac resistivity are also
+subjected to investigate the frequency dependency. An inverse relationship was
+observed between the composition dependence of dielectric constant and ac
+resistivity. The obtained results such as the electrical resistivity,
+dielectric constants and magnetic properties suggest the appropriateness of the
+studied ferrites in microwave device applications.",2007.00602v1
+2020-07-28,Defect Induced Room Temperature Ferromagnetism in High Quality Co-doped ZnO Bulk Samples,"The nature of the often reported room temperature ferromagnetism in
+transition metal doped oxides is still a matter of huge debate. Herein we
+report on room temperature ferromagnetism in high quality Co-doped ZnO
+(Zn1-xCoxO) bulk samples synthesized via standard solid-state reaction route.
+Reference paramagnetic Co-doped ZnO samples with low level of structural
+defects are subjected to heat treatments in a reductive atmosphere in order to
+introduce defects in the samples in a controlled way. A detailed structural
+analysis is carried out in order to characterize the induced defects and their
+concentration. The magnetometry revealed the coexistence of a paramagnetic and
+a ferromagnetic phase at room temperature in straight correlation with the
+structural properties. The saturation magnetization is found to increase with
+the intensification of the heat treatment, and, therefore, with the increase of
+the density of induced defects. The magnetic behavior is fully explained in
+terms of the bound magnetic polaron model. Based on the experimental findings,
+supported by theoretical calculations, we attribute the origin of the observed
+defect-induced-ferromagnetism to the ferromagnetic coupling between the Co ions
+mediated by magnetic polarons due to zinc interstitial defects.",2007.14140v1
+2020-11-08,Effect of Ti underlayer thickness on the magnetic anisotropy of TbFe thin films,"In this study, we address the impact of Ti underlayer thickness (UL: 0-40 nm)
+on the structural, magnetic, and microscopic properties of TbFe thin films. The
+structural analysis confirmed the intermixing at interfaces of the Ti and TbFe
+layer with the increment of UL thicknesses. Out-of-plane (OOP) coercivity (Hc),
+and saturation field (Hs) gradually increased with an increase in UL thickness
+regardless of interface mixing. For UL = 10 nm, the domain contrast and OOP
+stray field strength were enhanced, which may be due to the extent of d-d
+hybridization dominated over the influence of interfacial roughness. While for
+UL = 20, and 40 nm, the extent of interfacial roughness dominated the
+hybridization effects and as a result, stray fields deteriorated. By placing UL
+of 20 nm, Hc increased by nearly 6 times more than the bare TbFe system. So, we
+observe a state with high OOP Hc combined with nearly zero OOP stray fields
+that are found to co-exist in the sample. The magnetization reversal studies on
+a large area reveal domain nucleation followed by domain-wall motion in all the
+films. The idea of tuning magnetic properties by varying thicknesses of Ti UL
+may useful in spintronics applications.",2011.04068v1
+2020-11-17,Non-local magnon-based transport in yttrium iron garnet/platinum heterostructures at high temperatures,"The spin Hall effect in a heavy metal thin film allows to probe the magnetic
+properties of an adjacent magnetic insulator via magnetotransport measurements.
+Here, we investigate the magnetoresistive response of yttrium iron
+garnet/platinum heterostructures from room temperature to beyond the Curie
+temperature $T_\mathrm{C, YIG} \approx 560\,\mathrm{K}$ of the ferrimagnetic
+insulator. We find that the amplitude of the (local) spin Hall
+magnetoresistance decreases monotonically from $300\,\mathrm{K}$ towards
+$T_\mathrm{C}$, mimicking the evolution of the saturation magnetization of
+yttrium iron garnet. Interestingly, the spin Hall magnetoresistance vanishes
+around $500\,\mathrm{K}$, well below $T_\mathrm{C}$, which we attribute to the
+formation of a parasitic interface layer by interdiffusion. Around room
+temperature the non-local magnon-mediated magnetoresistance exhibits a power
+law scaling $T^{\alpha}$ with $\alpha = 3/2$, as already reported. The exponent
+decreases gradually to $\alpha \sim 1/2$ at around $420\,\mathrm{K}$, before
+the non-local magnetoresistance vanishes rapidly at a similar temperature as
+the spin Hall magnetoresistance. We attribute the reduced $\alpha$ at high
+temperatures to the increasing thermal magnon population which leads to
+enhanced scattering of the non-equilibrium magnon population and a reduced
+magnon diffusion length. Finally, we find a magnetic field independent offset
+voltage in the non-local signal for $T > 470\,\mathrm{K}$ which we associate
+with electronic leakage currents through the normally insulating yttrium iron
+garnet film. Indeed, this non-local offset voltage is thermally activated with
+an energy close to the band gap.",2011.08589v1
+2020-11-27,d0 Ferromagnetism in Li-doped ZnO Compounds,"Recently, d0 ferromagnetic materials have been projected as one of the
+promising novel materials for spintronics applications. In this work, we have
+studied Li-doped ZnO compounds, i.e. Zn1-xLixO (x=0, 0.02, 0.04, and 0.06)
+samples, prepared by the solid-state reaction route method. From the study of
+crystal structure using X-ray diffraction (XRD) patterns, it is evident that
+the prepared materials have been formed in a single-phase of the hexagonal
+wurtzite structure. The refinement of the XRD patterns suggests that there are
+very small changes in the lattice parameters upon Li-incorporation in ZnO. The
+average crystallite size (SC), estimated from XRD patterns was found to be in
+the range of 35-50 nm. The microstructural study by scanning electron
+microscope reveals the uniform morphology of the grains of the order of 50-70
+nm. The energy dispersive spectrum indicates that no unwanted ferromagnetic
+impurities have crept into the final prepared samples. The measurement of the
+temperature (T) variation of magnetization (M) with SQUID magnetometer
+indicates that undoped ZnO exhibits diamagnetic property but all Li-doped
+compounds exhibit room-temperature ferromagnetism and with a magnetic
+irreversibility behavior between zero-field cooled and field cooled M-T data.
+From the magnetization versus field measurements at 3 and 300 K, it is observed
+that Li-doped samples exhibit ferromagnetic loops with ultra-soft coercivity
+(~50 Oe) and with a maximum saturation magnetization of 0.10 emu/gm for x= 0.02
+sample, which decreases with the increase in Li concentration.",2011.13713v1
+2021-04-14,Solar large-scale magnetic field and cycle patterns in solar dynamo,"We compare spectra of the zonal harmonics of the large-scale magnetic field
+of the Sun using observation results and solar dynamo models. The main solar
+activity cycle as recorded in these tracers is a much more complicated
+phenomenon than the eigen solution of solar dynamo equations with the growth
+saturated by a back reaction of the dynamo-driven magnetic field on solar
+hydrodynamics. The nominal 11(22)-year cycle as recorded in each mode has a
+specific phase shift varying from cycle to cycle; the actual length of the
+cycle varies from one cycle to another and from tracer to tracer. Both the
+observation and the dynamo model show an exceptional role of the axisymmetric
+$\ell_{5}$ mode. Its origin seems to be readily connected with the formation
+and evolution of sunspots on the solar surface. The results of observations and
+dynamo models show a good agreement for the low $\ell_{1}$ and $\ell_{3}$
+modes. The results for these modes do not differ significantly for the
+axisymmetric and nonaxisymmetric models. Our findings support the idea that the
+sources of the solar dynamo arise as a result of both the distributed dynamo
+processes in the bulk of the convection zone and the surface magnetic activity.",2104.06808v2
+2021-06-04,Structural Monoclinicity and Its Coupling to Layered Magnetism in Few-Layer $\mathrm{CrI_{3}}$,"Using polarization-resolved Raman spectroscopy, we investigate layer number,
+temperature, and magnetic field dependence of Raman spectra in one- to
+four-layer $\mathrm{CrI_{3}}$. Layer-number-dependent Raman spectra show that
+in the paramagnetic phase a doubly degenerated $E_{g}$ mode of monolayer
+$\mathrm{CrI_{3}}$ splits into one $A_{g}$ and one $B_{g}$ mode in N-layer (N >
+1) $\mathrm{CrI_{3}}$ due to the monoclinic stacking. Their energy separation
+increases in thicker samples until an eventual saturation.
+Temperature-dependent measurements further show that the split modes tend to
+merge upon cooling but remain separated until 10 K, indicating a failed attempt
+of the monoclinic-to-rhombohedral structural phase transition that is present
+in the bulk crystal. Magnetic-field-dependent measurements reveal an additional
+monoclinic distortion across the magnetic-field-induced layered
+antiferromagnetism-to-ferromagnetism phase transition. We propose a structural
+change that consists of both a lateral sliding toward the rhombohedral stacking
+and a decrease in the interlayer distance to explain our experimental
+observations.",2106.02657v1
+2021-07-08,"Unconventional thermal and magnetic-field-driven changes of a bipartite entanglement of a mixed spin-(1/2,$S$) Heisenberg dimer with an uniaxial single-ion anisotropy","The concept of negativity is adapted in order to explore the quantum and
+thermal entanglement of the mixed spin-(1/2,$S$) Heisenberg dimers in presence
+of an external magnetic field. The mutual interplay between the spin size $S$,
+XXZ exchange and uniaxial single-ion anisotropy is thoroughly examined with a
+goal to tune the degree and thermal stability of the pairwise entanglement. It
+turns out that the antiferromagnetic spin-(1/2,$S$) Heisenberg dimers exhibit
+higher degree of entanglement and higher threshold temperature in comparison
+with their ferromagnetic counterparts when assuming the same set of model
+parameters. The increasing spin magnitude $S$ accompanied with an easy-plane
+uniaxial single-ion anisotropy can enhance not only the thermal stability but
+simultaneously the degree of entanglement. It is additionally shown that the
+further enhancement of a bipartite entanglement can be achieved in the mixed
+spin-(1/2,$S$) Heisenberg dimers, involving half-odd-integer spins $S$. Under
+this condition the thermal negativity saturates at low-enough temperatures in
+its maximal value regardless of the magnitude of half-odd-integer spin $S$. The
+magnetic field induces consecutive discontinuous phase transitions in the mixed
+spin-(1/2,$S$) Heisenberg dimers with $S\!>\!1$, which are manifested in a
+surprising oscillating magnetic-field dependence of the negativity observed at
+low enough temperature.",2107.05628v2
+2021-07-21,On the explosive phase of the tearing mode in double current sheet plasmas: effect of the equilibrium magnetic configuration on the onset threshold and growth rate,"Magnetic reconnection associated with the tearing instability occurring in
+double-current sheet systems is investigated within the framework of reduced
+resistive magnetohydrodynamics (MHD) in a two-dimensional Cartesian geometry.
+The explosive non linear phase is particularly explored using the adaptive
+finite-element FINMHD code. The critical aspect ratio, that is defined as the
+minimum $L/x_s$ ratio (with $L$ and $x_s$ being the periodic system length and
+half-distance between the two current layers respectively) necessary for non
+linear destabilization after the linear and early non linear saturation phases,
+is obtained. The latter threshold is independent of the details of the chosen
+initial equilibrium (double Harris-like magnetic profile) and of the
+resistivity. Its value is shown to be $4.7$, that is close and slightly smaller
+than the value of order $5$ deduced using a more particular equilibrium
+configuration in previous studies. The time dependence of the kinetic energy
+($E_K$) is shown to follow a double exponential law, $E_K \propto \exp \
+[e^{(\gamma^* t)} ]$, with a pseudo-growth rate $\gamma^* \simeq 0.1 \ t_A^
+{-1}$ ($t_A$ being the characteristic Alfv\'en time) that is again independent
+of the configuration and resistivity. The mechanism offers a possible
+explanation for the sudden onset of explosive magnetic energy release occurring
+on the fast Alfv\'en time scale in disruptive events of astrophysical plasmas
+with pre-existing double current sheets like in the solar corona.",2107.10069v2
+2021-08-16,Effects of spin-lattice coupling and a magnetic field in classical Heisenberg antiferromagnets on the breathing pyrochlore lattice,"We theoretically investigate spin-lattice coupling (SLC) effects on the
+in-field ordering properties of classical Heisenberg antiferromagnets on the
+breathing pyrochlore lattice. Here, we use the two possible simplified models
+describing the effect of local lattice distortions on the spin ordering via the
+SLC, the bond-phonon and site-phonon models. It is found by means of Monte
+Carlo simulations that in both models, the $\frac{1}{2}$ plateau shows up in
+the magnetization curve being relatively robust against the breathing
+bond-alternation, although magnetic long-range orders (LRO's) are realized only
+in the site-phonon model. In the bond-phonon model, additional further neighbor
+interactions are necessary to induce a magnetic LRO. In the site-phonon model,
+it is also found that in addition to the low-field, middle-field 1/2-plateau,
+and high-field phases appearing on both the uniform and breathing pyrochlore
+lattices, various types of unconventional phases which can be viewed as LRO's
+in units of tetrahedron are induced by the breathing bond-alternation just
+below the 1/2 plateau and the saturation field. The occurrence of these
+tetrahedron-based orders could be attributed to the nature characteristic of
+the breathing pyrochlore lattice, i.e., the existence of the nonequivalent
+small and large tetrahedra. Experimental implications of our result are also
+discussed.",2108.06961v2
+2021-11-07,"Sol-gel synthesized double perovskite Gd$_{2}$FeCrO$_{6}$ nanoparticles: Structural, magnetic and optical properties","Lead-free double perovskites are overtaking single perovskites as solar
+harvesting materials due to their superior stability, excellent catalytic
+efficiency and minimal toxicity. In this investigation, we have synthesized
+double perovskite Gd$_{2}$FeCrO$_{6}$ (GFCO) nanoparticles for the first time
+via a facile sol-gel technique to investigate their structural, magnetic and
+optical properties. The double perovskite GFCO crystallized in monoclinic
+structure with P2$_1$/n space group. The Fe/Cr-O bond length was calculated as
+$\sim$1.95 angstrom from the Raman spectrum which was consistent with the
+value, $\sim$1.99 angstrom obtained from X-ray diffraction analysis. The
+average size of the nanoparticles was determined to be $\sim$70 nm by both
+field emission scanning electron microscopy and transmission electron
+microscopy. The existence of mixed-valence states of Fe and Cr was confirmed by
+X-ray photoelectron spectroscopy. The zero-field cooled (ZFC) and field cooled
+(FC) curves largely diverged below 20 K. A downturn was observed in the ZFC
+curve at 15 K which corresponds to an antiferromagnetic, N\'eel transition. The
+narrow magnetic hysteresis loop recorded at 5 K was nearly saturated and
+demonstrated an asymmetric shift along the magnetic field axis indicating the
+concurrence of ferromagnetic and antiferromagnetic domains in GFCO
+nanoparticles. The UV-visible and photoluminescence spectroscopic analyses
+unveiled the semiconducting nature of nanostructured GFCO with an optical band
+gap of 2.0 eV. The as-synthesized thermally stable lead-free GFCO semiconductor
+might be a potential perovskite material to be employed in photocatalytic and
+related solar energy applications due to its ability to absorb the visible
+spectrum of the solar light efficiently",2111.04021v1
+2021-11-25,Tunable gigahertz dynamics of low-temperature skyrmion lattice in a chiral magnet,"Recently, it has been shown that the chiral magnetic insulator Cu$_2$OSeO$_3$
+hosts skyrmions in two separated pockets in temperature and magnetic field
+phase space. It has also been shown that the predominant stabilization
+mechanism for the low-temperature skyrmion (LTS) phase is via the crystalline
+anisotropy, opposed to temperature fluctuations that stabilize the
+well-established high-temperature skyrmion (HTS) phase. Here, we report on a
+detailed study of LTS generation by field cycling, probed by GHz spin dynamics
+in Cu$_2$OSeO$_3$. LTSs are populated via a field cycling protocol with the
+static magnetic field applied parallel to the $\langle{100}\rangle$ crystalline
+direction of plate and cuboid-shaped bulk crystals. By analyzing
+temperature-dependent broadband spectroscopy data, clear evidence of
+low-temperature skyrmion excitations with clockwise (CW), counterclockwise
+(CCW), and breathing mode (BR) character at temperatures below $T$ = 40 K are
+shown. We find that the mode intensities can be tuned with the number of
+field-cycles below the saturation field. By tracking the resonance frequencies,
+we are able to map out the field-cycle-generated LTS phase diagram, from which
+we conclude that the LTS phase is distinctly separated from the
+high-temperature counterpart. We also study the mode hybridization between the
+dark CW and the BR modes as a function of temperature. By using two
+Cu$_2$OSeO$_3$ crystals with different shapes and therefore different
+demagnetization factors, together with numerical calculations, we unambiguously
+show that the magnetocrystalline anisotropy plays a central role for the mode
+hybridization.",2111.13004v1
+2022-04-21,Magnetic phase transition induced ferroelectric polarization in BaFeF4 with room temperature weak ferromagnetism,"BaMF4 (M=Fe, Co, Ni and Mn) family are typical multiferroic materials, having
+antiferromagnetism at around liquid nitrogen temperature. In this work,
+polycrystalline BaFeF4 has been prepared by solid state reaction. The slight
+deficiency of Fe leads to the coexistence of valence states of +2 and +3,
+facilitating the electrons to hop between the neighboring Fe2+ and Fe3+ ions
+through the middle F- ion, leading to the strong double exchange interaction
+with weak ferromagnetism above room temperature. A bifurcation at about 170 K
+between the zero-field-cooled and field-cooled temperature dependent
+magnetization curves indicates the onset of 2-dimensional antiferromagnetism,
+which is completed at about 125 K with the sudden drop of magnetization.
+Despite the fact of type-I multiferroic, its magnetoelectricity can be
+evidenced by the pyroelectric current, which shows a peak starting at about 170
+K and finishing at about 125 K. The saturated ferroelectric polarization change
+of around 34 {\mu}C/m2 is observed, which is switchable by the reversed poling
+electric field and decreases to about 30 {\mu}C/m2 under a magnetic field of 90
+kOe. This magnetoelectricity can be qualitatively reproduced by
+first-principles calculations. Our results represent substantial progress to
+search for high-temperature multiferroics in ferroelectric fluorides.",2204.10052v1
+2022-05-17,MRI-driven dynamo at very high magnetic Prandtl numbers,"The dynamo driven by the magnetorotational instability (MRI) is believed to
+play an important role in the dynamics of accretion discs and may also explain
+the origin of the extreme magnetic fields present in magnetars. Its saturation
+level is an important open question known to be particularly sensitive to the
+diffusive processes through the magnetic Prandtl number Pm (the ratio of
+viscosity to resistivity). Despite its relevance to proto-neutron stars and
+neutron star merger remnants, the numerically challenging regime of high Pm is
+still largely unknown. Using zero-net flux shearing box simulations in the
+incompressible approximation, we studied MRI-driven dynamos at unprecedentedly
+high values of Pm reaching 256. The simulations show that the stress and
+turbulent energies are proportional to Pm up to moderately high values
+($\mathrm{Pm} \sim 50$). At higher Pm, they transition to a new regime
+consistent with a plateau independent of Pm for $\rm Pm \gtrsim 100$. This
+trend is independent of the Reynolds number, which may suggest an asymptotic
+regime where the energy injection and dissipation are independent of the
+diffusive processes. Interestingly, large values of Pm not only lead to intense
+small-scale magnetic fields but also to a more efficient dynamo at the largest
+scales of the box.",2205.08602v2
+2022-08-16,Numerical dependencies of the galactic dynamo in isolated galaxies with SPH,"Understanding the numerical dependencies that act on the galactic dynamo is a
+crucial step in determining what resolution and what conditions are required to
+properly capture the magnetic fields observed in galaxies. Here, we present an
+extensive study on the numerical dependencies of the galactic dynamo in
+isolated spiral galaxies using smoothed particle magnetohydrodynamics (SPMHD).
+We performed 53 isolated spiral galaxy simulations with different initial
+setups, feedback, resolution, Jeans floor and dissipation parameters. The
+results show a strong mean-field dynamo occurring in the spiral-arm region of
+the disk, likely produced by the classical alpha-omega dynamo or the recently
+described gravitational instability dynamo. The inclusion of feedback is seen
+to work in both a destructive and positive fashion for the amplification
+process. Destructive interference for the amplification occurs due to break
+down of filament structure in the disk, increase of turbulent diffusion and the
+ejection of magnetic flux from the central plane to the circumgalactic medium.
+The positive effect of feedback is the increase in vertical motions and the
+turbulent fountain flows that develop, showing a high dependence on the
+small-scale vertical structure and the numerical dissipation within the galaxy.
+Galaxies with an effective dynamo saturate their magnetic energy density at
+levels between 10-30% of the thermal energy density. The density averaged
+numerical Prandtl number is found to be below unity throughout the galaxy for
+all our simulations, with an increasing value with radius. Assuming a turbulent
+injection length of 1 kpc, the numerical magnetic Reynolds number are within
+the range of $Re_{mag}=10-400$, indicating that some regions are below the
+levels required for the small-scale dynamo ($Re_{mag,crit}=30-2700$) to be
+active.",2208.07889v1
+2022-11-04,Exchange energies in CoFeB/Ru/CoFeB Synthetic Antiferromagnets,"The interlayer exchange coupling confers specific properties to Synthetic
+Antiferromagnets that make them suitable for several applications of
+spintronics. The efficient use of this magnetic configuration requires an
+in-depth understanding of the magnetic properties and their correlation with
+the material structure. Here we establish a reliable procedure to quantify the
+interlayer exchange coupling and the intralayer exchange stiffness in synthetic
+antiferromagnets; we apply it to the ultrasmooth and amorphous
+Co$_{40}$Fe$_{40}$B$_{20}$ (5-40 nm)/Ru/ Co$_{40}$Fe$_{40}$B$_{20}$ material
+platform. The complex interplay between the two exchange interactions results
+in a gradient of the magnetization orientation across the thickness of the
+stack which alters the hysteresis and the spin wave eigenmodes of the stack in
+a non trivial way. We measured the field-dependence of the frequencies of the
+first four spin waves confined within the thickness of the stack. We modeled
+these frequencies and the corresponding thickness profiles of these spin waves
+using micromagnetic simulations. The comparison with the experimental results
+allows to deduce the magnetic parameters that best account for the sample
+behavior. The exchange stiffness is established to be 16 $\pm$ 2 pJ/m,
+independently of the Co$_{40}$Fe$_{40}$B$_{20}$ thickness. The interlayer
+exchange coupling starts from -1.7 mJ/m$^2$ for the thinnest layers and it can
+be maintained above -1.3 mJ/m$^2$ for CoFeB layers as thick as 40 nm. The
+comparison of our method with earlier characterizations using the sole
+saturation fields argues for a need to revisit the tabulated values of
+interlayer exchange coupling in thick synthetic antiferromagnets.",2211.02497v1
+2022-11-16,Saturation of the magnetorotational instability and the origin of magnetically elevated accretion discs,"We propose that the strength of angular momentum transport in accretion discs
+threaded by net vertical magnetic field is determined by a self-regulation
+mechanism: the magnetorotational instability (MRI) grows until its own
+turbulent resistivity damps the fastest growing mode on the scale of the disc
+thickness. Given weak assumptions as to the structure of MRI-derived
+turbulence, supported by prior simulation evidence, the proposed mechanism
+reproduces the known scaling of the viscous $\alpha$-parameter, $\alpha \propto
+\beta_z^{-1/2}$. Here, $\beta_z = 8\pi p_g/B_{z0}^2$ is the initial plasma
+$\beta$-parameter on the disc midplane, $B_{z0}$ is the net field, and $p_g $
+is the midplane gas pressure. We generalize the argument to discs with strong
+suprathermal toroidal magnetic fields, where the MRI growth rate is modified
+from the weak-field limit. Additional sources of turbulence are required if
+such discs are to become magnetically elevated, with the increased scale
+heights near the midplane that are seen in simulations. We speculate that
+tearing modes, associated with current sheets broadened by the effective
+resistivity, are a possible source of enhanced turbulence in elevated discs.",2211.09261v2
+2022-12-30,Boundary Quantum Phase Transitions in the Spin $\frac{1}{2}$ Heisenberg Chain with Boundary Magnetic Fields,"We consider the spin $\frac{1}{2}$ Heisenberg chain with boundary magnetic
+fields and analyze it using a combination of Bethe ansatz and density matrix
+renormalization group (DMRG) techniques. We show that the system exhibits
+several different ground states which depend on the orientation of the boundary
+magnetic fields. When both the boundary fields take equal values greater than a
+critical field strength, each edge in the ground state accumulates a fractional
+spin which saturates to spin $\frac{1}{4}$, which is similar to systems
+exhibiting symmetry protected topological phases (SPT). Unlike in SPT systems,
+the fractional boundary spin in the Heisenberg spin chain is not a genuine
+quantum number since the variance of the associated operator does not vanish,
+this is due to the absence of a bulk gap. The system exhibits high energy bound
+states when the boundary fields take values greater than the critical field.
+All the excitations in the system can be sorted out into towers whose number
+depends on the number of bound states exhibited by the system. As the boundary
+fields are varied, in addition to the ground state phase transition, we find
+that the system may undergo an eigenstate phase transition (EPT) where the
+number of towers of the Hilbert space changes. We further inquire how the EPT
+reflects itself on local ground state properties by computing the magnetization
+profile $\langle S^z_j \rangle$ using DMRG. We identify a clear qualitative
+change from low edge fields to high edge fields when crossing the critical
+field. We though are unable to conclude on the basis of our data that EPT
+corresponds to a genuine phase transition in the ground state.",2212.14832v1
+2023-03-22,Enhancing Spin Transfer Torque in Magnetic Tunnel Junction Devices: Exploring the Influence of Capping Layer Materials and Thickness on Device Characteristics,"We have developed and optimized two categories of spin transfer torque
+magnetic tunnel junctions (STT-MTJs) that exhibit a high tunnel
+magnetoresistance (TMR) ratio, low critical current, high outputpower in the
+micro watt range, and auto-oscillation behavior. These characteristics
+demonstrate the potential of STT-MTJs for low-power, high-speed, and reliable
+spintronic applications, including magnetic memory, logic, and signal
+processing. The only distinguishing factor between the two categories, denoted
+as A-MTJs and B-MTJs, is the composition of their free layers, 2 CoFeB/0.21
+Ta/6 CoFeSiB for A-MTJs and 2 CoFeB/0.21 Ta/7 NiFe for B-MTJs. Our study
+reveals that B-MTJs exhibit lower critical currents for auto-oscillation than
+A-MTJs. We found that both stacks have comparable saturation magnetization and
+anisotropy field, suggesting that the difference in auto-oscillation behavior
+is due to the higher damping of A-MTJs compared to B-MTJs. To verify this
+hypothesis, we employed the all-optical time-resolved magneto-optical Kerr
+effect (TRMOKE) technique, which confirmed that STT-MTJs with lower damping
+exhibited auto-oscillation at lower critical current values. Additionally, our
+study aimed to optimize the STT-MTJ performance by investigating the impact of
+the capping layer on the device's response to electronic and optical stimuli.",2303.12450v2
+2023-05-30,Dynamic and Rapid Deep Synthesis of Molecular MRI Signals,"Model-driven analysis of biophysical phenomena is gaining increased attention
+and utility for medical imaging applications. In magnetic resonance imaging
+(MRI), the availability of well-established models for describing the relations
+between the nuclear magnetization, tissue properties, and the externally
+applied magnetic fields has enabled the prediction of image contrast and served
+as a powerful tool for designing the imaging protocols that are now routinely
+used in the clinic. Recently, various advanced imaging techniques have relied
+on these models for image reconstruction, quantitative tissue parameter
+extraction, and automatic optimization of acquisition protocols. In molecular
+MRI, however, the increased complexity of the imaging scenario, where the
+signals from various chemical compounds and multiple proton pools must be
+accounted for, results in exceedingly long model simulation times, severely
+hindering the progress of this approach and its dissemination for various
+clinical applications. Here, we show that a deep-learning-based system can
+capture the nonlinear relations embedded in the molecular MRI Bloch-McConnell
+model, enabling a rapid and accurate generation of biologically realistic
+synthetic data. The applicability of this simulated data for in-silico,
+in-vitro, and in-vivo imaging applications is then demonstrated for chemical
+exchange saturation transfer (CEST) and semisolid macromolecule magnetization
+transfer (MT) analysis and quantification. The proposed approach yielded
+78%-99% acceleration in data synthesis time while retaining excellent agreement
+with the ground truth (Pearson's r$>$0.99, p$<$0.0001, normalized root mean
+square error $<$3%).",2305.19413v1
+2023-08-31,Flares in the Galactic Centre II: polarisation signatures of flares at mm-wavelengths,"Recent polarimetric mm-observations of the galactic centre by Wielgus et al.
+(2022a) showed sinusoidal loops in the Q-U plane with a duration of one hour.
+The loops coincide with a quasi-simultaneous X-ray flare. A promising mechanism
+to explain the flaring events are magnetic flux eruptions in magnetically
+arrested accretion flows (MAD). In our previous work (Porth et al. 2021), we
+studied the accretion flow dynamics during flux eruptions. Here, we extend our
+previous study by investigating whether polarization loops can be a signature
+produced by magnetic flux eruptions. We find that loops in the Q-U plane are
+robustly produced in MAD models as they lead to enhanced emissivity of
+compressed disk material due to orbiting flux bundles. A timing analysis of the
+synthetic polarized lightcurves demonstrate a polarized excess variability at
+timescales of ~ 1 hr. The polarization loops are also clearly imprinted on the
+cross-correlation of the Stokes parameters which allows to extract a typical
+periodicity of 30 min to 1 hr with some evidence for a spin dependence. These
+results are intrinsic to the MAD state and should thus hold for a wide range of
+astrophysical objects. A subset of GRMHD simulations without saturated magnetic
+flux (single temperature SANE models) also produces Q-U loops. However, in
+disagreement with the findings of Wielgus et al. (2022a), loops in these
+simulations are quasi-continuous with a low polarization excess",2308.16740v1
+2023-10-13,"Magnetic structure, excitations and field induced transitions in the honeycomb lattice $\rm{Er_2Si_2O_7}$","We investigate the magnetic properties of the monoclinic D-type
+$\rm{Er_2Si_2O_7}$ with a distorted honeycomb lattice using powder and single
+crystal neutron scattering techniques, as well as single crystal magnetisation
+measurements. The powder neutron diffraction shows that below the ordering
+temperature, $T_{\rm N}=1.85$ K, the compound forms a ${\bf q}=0$
+antiferromagnetic structure with four sublattices. For $H \! \parallel \! a$,
+magnetisation measurements reveal a narrow, but clearly visible plateau at one
+third of the magnetisation saturation value. The plateau's stabilisation is
+accompanied by a significant increase of the magnetic unit cell, as the
+magnetic peaks with fractional indices are observed in single crystal neutron
+diffraction experiments. At low-temperatures, the inelastic neutron scattering
+measurements reveal the presence of low-energy dispersionless excitations.
+Their spectrum is sensitive to the applied field, it significantly softens on
+the magnetisation plateau, and demonstrates the behaviour expected for a
+non-collinear Ising antiferromagnet away from the plateau.",2310.09268v3
+2023-11-13,Robust magnetic proximity induced anomalous Hall effect in a room temperature van der Waals ferromagnetic semiconductor based 2D heterostructure,"Developing novel high-temperature van der Waals ferromagnetic semiconductor
+materials and investigating their interface coupling effects with
+two-dimensional topological semimetals are pivotal for advancing
+next-generation spintronic and quantum devices. However, most van der Waals
+ferromagnetic semiconductors exhibit ferromagnetism only at low temperatures,
+limiting the proximity research on their interfaces with topological
+semimetals. Here, we report an intrinsic, van der Waals layered
+room-temperature ferromagnetic semiconductor crystal, FeCr0.5Ga1.5Se4 (FCGS),
+with a Curie temperature as high as 370 K, setting a new record for van der
+Waals ferromagnetic semiconductors. The saturation magnetization at low
+temperature (2 K) and room temperature (300 K) reaches 8.2 emu/g and 2.7 emu/g,
+respectively. Furthermore, FCGS possesses a bandgap of approximately 1.2 eV,
+which is comparable to the widely used commercial silicon. The FCGS/graphene
+heterostructure exhibits an impeccably smooth and gapless interface, thereby
+inducing a robust magnetic proximity coupling effect between FCGS and graphene.
+After the proximity coupling, graphene undergoes a charge carrier transition
+from electrons to holes, accompanied by a transition from non-magnetic to
+ferromagnetic transport behavior with robust anomalous Hall effect. Notably,
+the anomalous Hall effect remains robust even temperatures up to 400 K.",2311.07183v1
+2024-02-11,Probing Magnetic and Triplet Correlations in Spin-Split Superconductors with Magnetic Impurities,"A superconductor (SC) in proximity to a ferromagnetic insulator (FMI) is
+predicted to exhibit mixed singlet and triplet pair correlations. The magnetic
+proximity effect of FMI spin-splits the energy of Bogoliubov excitations and
+leads to a spin polarization at the surface for superconducting films thinner
+than the superconducting coherence length. In this work, we study
+manifestations of these phenomena in the properties of a magnetic impurity
+coupled via Kondo coupling to this FMI/SC system. Using the numerical
+renormalization group (NRG) method, we compute the properties of the ground
+state and low-lying excited states of a model that incorporates the Kondo
+interaction and a Ruderman-Kittel-Kasuya-Yosida (RKKY)-like interaction with
+the surface spin polarization. Our main finding is an energy splitting of the
+lowest even fermion-parity states caused by the proximity to the FMI. As the
+Kondo coupling increases, the splitting grows and saturates to a universal
+value equal to twice the exchange field of the FMI. We introduce a two-site
+model that can be solved analytically and provides a qualitative understanding
+of this and other NRG results. In addition, using perturbation theory we
+demonstrate that the mechanism behind the splitting involves the RKKY field and
+the triplet correlations of the spin-split superconductor. A scaling analysis
+combined with NRG shows that the splitting can be written as a single-parameter
+scaling function of the ratio of the Kondo temperature and the superconducting
+gap, which is also numerically obtained.",2402.07184v1
+2024-02-16,Live magnetic observation of parahydrogen hyperpolarization dynamics,"Nuclear spin hyperpolarization is used in physics, chemistry, and medicine to
+produce strong magnetization unachievable by equilibrium polarization
+techniques. Hyperpolarization enables magnetic resonance spectroscopy and
+imaging with minute samples, and is used to produce MRI spin-tracers and
+polarized physics targets. Although widely used, the dynamics of the
+hyperpolarization process have never been studied `live' due to the extremely
+low (Hz-band) frequencies involved, and/or detector saturation by the driving
+fields used. Here, we use an atomic magnetometer with sub-pT sensitivity to
+observe, in real time, the complex dynamics of hyperpolarization, without
+disturbing or disrupting the process. We start by examining
+parahydrogen-induced $^1$H and $^{13}$C magnetization build-up during adiabatic
+eigenbasis transformations in the $\mu$T-field avoided state crossings at the
+heart of the process; we see live hyperpolarization dynamics including coherent
+oscillations, leakage mechanisms and dipolar shifts that would be challenging
+or impossible to observe by post hoc measurement. We then extend the methods to
+observe the chemical-exchange-driven $^{13}$C hyperpolarization of
+[1-$^{13}$C]-pyruvate -- the most important spin tracer for clinical metabolic
+imaging. Beyond the interests of hyperpolarization, the observation of
+adiabatic transitions in real-time is a fundamentally new approach to NMR,
+reveals previously hidden nuclear spin dynamics and enables quantum control and
+live process optimization in a variety of chemical scenarios.",2402.10766v1
+2024-03-14,Inelastic neutron scattering and muon spin relaxation investigations of the deuterated Kondo lattices CeNiSnD$ _x $,"CeNiSn is a Kondo semimetal where a gap opens at low temperatures due to
+hybridization between 4$f$ and conduction electrons, but a full insulating
+state fails to develop. Upon the insertion of hydrogen, long range magnetic
+order is induced. Here we report zero-field muon-spin relaxation and inelastic
+neutron scattering measurements of polycrystalline samples of the deuterides
+CeNiSnD$_x$ ($x$=1.0, 1.8). The muon-spin relaxation results confirm magnetic
+ordering in the whole sample of CeNiSnD below around 4.7 K, while inelastic
+neutron scattering reveals two well-defined crystalline-electric field (CEF)
+excitations at around 13 meV and 34 meV in CeNiSnD, and 5 meV and 27 meV for
+CeNiSnD$_{1.8}$. These results suggest that hydrogenation leads to the
+localization of the Ce-4$f$ electrons, giving rise to long-range magnetic
+order. We propose CEF level schemes for both systems, which predict a ground
+state moment of 0.96$\mu_{\rm B}$/Ce within the $ab$-plane for CeNiSnD$_{1.8}$
+and a saturated moment of 1.26$\mu_{\rm B}$/Ce along the easy $c$ axis for
+CeNiSnD, that account for the observed magnetic properties.",2403.09424v1
+2019-07-12,On induced saturation for paths,"For a graph $H$, a graph $G$ is $H$-induced-saturated if $G$ does not contain
+an induced copy of $H$, but either removing an edge from $G$ or adding a
+non-edge to $G$ creates an induced copy of $H$. Depending on the graph $H$, an
+$H$-induced-saturated graph does not necessarily exist. In fact, Martin and
+Smith (2012) showed that $P_4$-induced-saturated graphs do not exist, where
+$P_k$ denotes a path on $k$ vertices. Axenovich and Csik\'{o}s (2019) asked the
+existence of $P_k$-induced-saturated graphs for $k \ge 5$; it is easy to
+construct such graphs when $k\in\{2, 3\}$. Recently, R\""{a}ty constructed a
+graph that is $P_6$-induced-saturated. In this paper, we show that there exists
+a $P_{k}$-induced-saturated graph for infinitely many values of $k$. To be
+precise, we find a $P_{3n}$-induced-saturated graph for every positive integer
+$n$. As a consequence, for each positive integer $n$, we construct infinitely
+many $P_{3n}$-induced-saturated graphs. We also show that the Kneser graph
+$K(n,2)$ is $P_6$-induced-saturated for every $n\ge 5$.",1907.05546v1
+2022-06-01,Defensive Design of Saturating Counters Based on Differential Privacy,"The saturating counter is the basic module of the dynamic branch predictor,
+which involves the core technique to improve instruction level parallelism
+performance in modern processors. However, most studies focus on the
+performance improvement and hardware consumption of saturating counters, while
+ignoring the security problems they may cause. In this paper, we creatively
+propose to study and design saturating counters from the defense perspective of
+differential privacy, so that attackers cannot distinguish the states that
+saturating counters are in and further infer sensitive information. To obtain
+theoretical guarantees, we use Markov chain to formalize the attack algorithm
+applied to the saturating counter, investigate into the optimal attack strategy
+and calculate the probability of successful attack. Furthermore, we find that
+the attacker is able to accurately guess the branch execution of the victim's
+process in the existing saturating counters. To avoid this, we design a new
+probabilistic saturating counter, which generalizes the existing conventional
+and probabilistic saturating counters. The guarantee of differential privacy is
+applied to deduce parameters of the new saturating counters so that the
+security requirement can be satisfied. We also theoretically calculate the
+misprediction rate when the saturating counter reaches the steady state. The
+experimental results on testing programs show that the calculated theoretical
+results agree with the experimental performances. Compared with the existing
+conventional and probabilistic saturating counters, when the parameters of our
+designed models are selected appropriately, the new saturating counters can not
+only ensure similar operational performance, but also establish strict security
+guarantee.",2206.00279v1
+1994-08-04,Gamma-Rays from the Funnels of Thick Accretion Disks Around Active Galactic Nuclei,"We analyse the propagation of particles in the narrow funnel of a thick
+accretion disk. It is assumed that: (1) the funnel walls emit black body
+radiation with temperature decreasing outwards; (2) the magnetic and electric
+fields are longitudinal in the funnel. Such a scenario is consistent with
+models in which a large potential drop is induced by a rotating massive black
+hole threaded by a magnetic field (Blandford & Znajek 1977, Macdonald & Thorne
+1982). The interaction of relativistic protons with thermal photons from the
+funnel results in direct production of pairs and/or pions. We discuss the
+relative importance of these processes for different conditions in the funnel
+(temperature and electric field profiles). Injected pairs interact with thermal
+photons in the Thomson or Klein-Nishina regime. Under some conditions, a pair
+avalanche results, which we assume saturates in the production of stable
+bunches, containing almost equal numbers of electrons and positrons. As a
+consequence, highly collimated gamma-ray photons are produced. We obtain
+gamma-ray spectra from our model in order to test its applicability to the
+gamma-ray emitting AGNs recently reported by EGRET.",9408013v1
+1996-09-18,The origin of large scale magnetic fields,"Magnetic fields correlated on several kiloparsec scales are seen in spiral
+galaxies. Their origin could be due to the winding up of a primordial
+cosmological field or due to amplification of a small seed field by a turbulent
+galactic dynamo. Both options have difficulties: There is no known battery
+mechanism for producing the required primordial field. Equally the turbulent
+dynamo may self destruct before being able to produce the large scale field,
+due to excess generation of small scale power. The current status of these
+difficulties is discussed. The resolution could depend on the nature of the
+saturated field produced by the small scale dynamo. We argue that the small
+scale fields do not fill most of the volume of the fluid and instead
+concentrate into intermittent ropes, with their peak value of order
+equipartition fields, and radii much smaller than their lengths. In this case
+these fields neither drain significant energy from the turbulence nor convert
+eddy motion of the turbulence on the outer scale to wave like motion. This
+preserves the diffusive effects needed for the large scale dynamo operation.",9609123v1
+1998-05-07,Angular Momentum Transport in the Central Region of the Galaxy,"We discuss mechanisms for angular momentum transport in the clumpy medium of
+the circumnuclear disk at the Galactic center. The viscosity due to clump-clump
+collisions is found to be less than some critical viscosity; this meets the
+conditions at which a collective mode of nonaxisymmetric shear perturbations in
+the disk is able to grow until going into the saturation regime where fully
+developed turbulence is established. We find that the angular momentum transfer
+due to this turbulent viscosity turns out to comparable to the transport due to
+magnetic torques. Taken together, the turbulent and magnetic transfer of
+angular momentum are able to provide the inflow of mass into the central parsec
+with a rate of about 10^{-2} M_{sun}/yr, consistent with the available data.",9805098v1
+1999-04-22,Monopole-antimonopole bound states as a source of ultra-high-energy cosmic rays,"The electromagnetic decay and final annihilation of magnetic
+monopole-antimonopole pairs formed in the early universe has been proposed as a
+possible mechanism to produce the highest energy cosmic rays. We show that for
+a monopole abundance saturating the Parker limit, the density of magnetic
+monopolonium formed is many orders of magnitude less than that required to
+explain the observed cosmic ray flux. We then propose a different scenario in
+which the monopoles and antimonopoles are connected by strings formed at a low
+energy phase transition (~ 100 GeV). The bound states decay by gravitational
+radiation, with lifetimes comparable with the age of the universe. This
+mechanism avoids the problems of the standard monopolonium scenario, since the
+binding of monopoles and antimonopoles is perfectly efficient.",9904315v1
+1999-08-25,A Unified treatment of small and large- scale dynamos in helical turbulence,"Helical turbulence is thought to provide the key to the generation of
+large-scale magnetic fields. Turbulence also generically leads to rapidly
+growing small-scale magnetic fields correlated on the turbulence scales. These
+two processes are usually studied separately. We give here a unified treatment
+of both processes, in the case of random fields, incorporating also a simple
+model non-linear drift. In the process we uncover an interesting plausible
+saturated state of the small-scale dynamo and a novel analogy between quantum
+mechanical (QM) tunneling and the generation of large scale fields. The steady
+state problem of the combined small/large scale dynamo, is mapped to a
+zero-energy, QM potential problem; but a potential which, for non-zero mean
+helicity, allows tunneling of bound states. A field generated by the
+small-scale dynamo, can 'tunnel' to produce large-scale correlations, which in
+steady state, correspond to a force-free 'mean' field.",9908280v1
+2001-06-15,Astrophysical significance of the anisotropic kinetic alpha effect,"The generation of large scale flows by the anisotropic kinetic alpha (AKA)
+effect is investigated in simulations with a suitable time-dependent space- and
+time-periodic anisotropic forcing lacking parity invariance. The forcing
+pattern moves relative to the fluid, which leads to a breaking of the Galilean
+invariance as required for the AKA effect to exist. The AKA effect is found to
+produce a clear large scale flow pattern when the Reynolds number, R, is small
+as only a few modes are excited in linear theory. In this case the
+non-vanishing components of the AKA tensor are dynamically independent of the
+Reynolds number. For larger values of R, many more modes are excited and the
+components of the AKA tensor are found to decrease rapidly with increasing
+value of R. However, once there is a magnetic field (imposed and of sufficient
+strength, or dynamo-generated and saturated) the field begins to suppress the
+AKA effect, regardless of the value of R. It is argued that the AKA effect is
+unlikely to be astrophysically significant unless the magnetic field is weak
+and R is small.",0106280v1
+2002-07-22,A New Dynamical Mean-Field Dynamo Theory and Closure Approach,"We develop a new nonlinear mean field dynamo theory that couples field growth
+to the time evolution of the magnetic helicity and the turbulent electromotive
+force, $\emfb$. We show that the difference between kinetic and current
+helicities emerges naturally as the growth driver when the time derivative of
+$\emfb$ is coupled into the theory. The solutions predict significant field
+growth in a kinematic phase and a saturation rate/strength that is magnetic
+Reynolds number dependent/independent in agreement with numerical simulations.
+The amplitude of early time oscillations provides a diagnostic for the closure.",0207435v3
+2004-10-27,Magnetic field generation in fully convective rotating spheres,"Magnetohydrodynamic simulations of fully convective, rotating spheres with
+volume heating near the center and cooling at the surface are presented. The
+dynamo-generated magnetic field saturates at equipartition field strength near
+the surface. In the interior, the field is dominated by small-scale structures,
+but outside the sphere by the global scale. Azimuthal averages of the field
+reveal a large-scale field of smaller amplitude also inside the star. The
+internal angular velocity shows some tendency to be constant along cylinders
+and is ``anti-solar'' (fastest at the poles and slowest at the equator).",0410645v2
+2005-01-21,Diffusion coefficient of a passive contaminant in a local MHD model of a turbulent accretion disc,"We calculate the radial diffusion coefficient for a passive contaminant in an
+accretion disc which is turbulent due to the action of the magnetorotational
+instability. Numerical MHD simulations are used to follow the evolution of a
+local patch of the disc using the shearing box formalism. A separate continuity
+equation for the mass fraction of contaminant is integrated along with the MHD
+system, and radial profiles of this fraction are obtained as a function of
+time. Solutions of a linear diffusion equation are fitted to the numerical
+measured profiles of the contaminant, treating the diffusion coefficient D as
+the fitting parameter. At early times, the value of D is found to vary, however
+once the contaminant is spread over scales comparable to the box size, it
+saturates at a steady value. The ratio of D to the transport coefficient of
+angular momentum due to shear stress is small. If D can be used as a proxy for
+the turbulent magnetic diffusivity, the effective magnetic Prandtl number
+P_eff=\nu/D (where \nu is the coefficient of ""efective viscosity"" associated
+with shear stress) would be large.",0501474v1
+2006-07-06,Empirical relation between angular momentum transport and thermal-to-magnetic pressure ratio in shearing box simulations,"By combining data from different published 3-D simulations of Keplerian
+shearing boxes unstable to the magnetorotational instability (MRI), we
+highlight tight anti-correlations between the total effective inferred angular
+momentum transport parameter, $\alpha_{tot}$, its separate Maxwell and Reynolds
+contributions $\alpha_{mag}$ and $\alpha_{kin}$, and the kinetic to magnetic
+pressure ratio $\beta$, defined with the initial or saturated (when available)
+thermal pressure.
+  Plots of $Log (\alpha_{kin}), Log (\alpha_{mag})$, and $Log (\alpha_{tot})$
+vs $Log (\beta)$ are well fit by straight lines even as $\alpha_{kin}$,
+$\alpha_{mag}$,and $\alpha_{tot}$ vary by four orders of magnitude over the
+simulations included. The ratio $\alpha_{kin}/\alpha_{mag}$ and the product
+$\alpha_{tot}\beta$ are quite constant and largely independent of the presence
+or absence of weak mean fields, the choice of initial and boundary conditions,
+and the resolution. In short, simulations have more strongly constrained the
+product $\alpha_{tot}\beta$ than $\alpha_{tot}$ itself.",0607119v4
+2006-12-27,"Spectral Methods for Time-Dependent Studies of Accretion Flows. III. Three-Dimensional, Self-gravitating, Magnetohydrodynamic Disks","Accretion disks are three-dimensional, turbulent, often self-gravitating,
+magnetohydrodynamic flows, which can be modeled in detail with numerical
+simulations. In this paper, we present a new algorithm that is based on a
+spectral decomposition method to simulate such flows. Because of the high order
+of the method, we can solve the induction equation in terms of the magnetic
+potential and, therefore, ensure trivially that the magnetic fields in the
+numerical solution are divergence free. The spectral method also suffers
+minimally from numerical dissipation and allows for an easy implementation of
+models for sub-grid physics. Both properties make our method ideal for studying
+MHD turbulent flows such as those found in accretion disks around compact
+objects. We verify our algorithm with a series of standard tests and use it to
+show the development of MHD turbulnce in a simulation of an accretion disk.
+Finally, we study the evolution and saturation of the power spectrum of MHD
+turbulence driven by the magnetorotational instability.",0612742v1
+1994-10-10,Monte Carlo Simulation of Ising Models with Dipole Interaction,"Recently, a new memory effect was found in the metamagnetic domain structure
+of the diluted Ising antiferromagnet $Fe_x Mg_{1-x} Cl_2$ by domain imaging
+with Faraday contrast. Essential for this effect is the dipole interaction. We
+simulate the low temperature behavior of diluted Ising-antiferromagnets by a
+Monte Carlo simulation considering long range interaction. The metamagnetic
+domain structure occurring due to the dipole interaction is investigated by
+graphical representation. In the model considered the antiferromagnetic state
+is stable for an external magnetic field smaller than a lower boundary $B_{c1}$
+while for fields larger than an upper boundary $B_{c2}$ the system is in the
+saturated paramagnetic phase, where the spins are ferromagnetically polarized.
+For magnetic fields in between these two boundaries a mixed phase occurs
+consisting of ferromagnetic domains in an antiferromagnetic background. The
+position of these ferromagnetic domains is stored in the system: after a cycle
+in which the field is first removed and afterwards applied again the domains
+reappear at their original positions. The reason for this effect can be found
+in the frozen antiferromagnetic domain state which occurs after removing the
+field.",9410028v1
+1998-07-03,Temperature dependence of the normal-state Hall coefficient of a quasi-one-dimensional metal,"We develop a systematic theory of the Hall effect in Q1D conductors in both
+weak and strong magnetic fields for a model where the electron relaxation time
+varies over the Fermi surface. At high temperatures, the Hall coefficient
+saturates at the value $-\beta/ecn$, where the dimensionless coefficient
+$\beta$ is determined by the curvature of the longitudinal dispersion law of
+electrons, $e$ the electron charge, $c$ is the speed of light, and $n$ is the
+hole concentration. At low temperatures, where a strong variation of the
+relaxation rate over the Fermi surface develops in the form of ``hot spots'',
+the Hall coefficient becomes temperature-dependent and may change sign for a
+particular choice of the transverse dispersion law parameters. In our model,
+the sign changes in a weak, but not in a strong magnetic field.",9807047v3
+1999-03-26,Resistive Transition and Upper Critical Field in Underdoped YBa_2Cu_3O_{6+x} Single Crystals,"A superconducting transition in the temperature dependence of the ab-plane
+resistivity of underdoped YBa_2Cu_3O_{6+x} crystals in the range T_c<30 K has
+been investigated. Unlike the case of samples with the optimal level of doping,
+the transition width increased insignificantly with magnetic field, and in the
+range T_c<13 K it decreased with increasing magnetic field. The transition
+point T_c(B) was determined by analyzing the fluctuation conductivity. The
+curves of B_{c2}(T) measured in the region T/T_c>0.1 did not show a tendency to
+saturation and had a positive second derivative everywhere, including the
+immediate neighborhood of T_c. The only difference among the curves of
+B_{c2}(T) for different crystal states is the scales of T and B, so they can be
+described in terms of a universal function, which fairly closely follows
+Alexandrov's model of boson superconductivity.",9903397v1
+1999-04-22,Magnetotransport in manganites and the role of quantal phases II: Experiment,"As in conventional ferromagnets, the Hall resistivity rho_xy of a
+La_{2/3}(Ca,Pb)_{1/3}MnO_3 single crystal exhibits both ordinary and anomalous
+contributions at low temperature. However, these contributions, unexpectedly,
+have opposite signs. Near Tc, the ordinary contribution is no longer evident
+and rho_xy is solely determined by the sample magnetization, reaching an
+extremum at approximately 40% of the saturated magnetization. A new model for
+the anomalous Hall effect, incorporating the quantal phase accumulated by
+double-exchange, three-site hopping reproduces this result. Below Tc, rho_xy
+reflects the competition between normal and anomalous Hall effects.",9904332v1
+1999-07-22,Charge carrier density collapse in La_0.67Ca_0.33MnO_3 and La_0.67Sr_0.33MnO_3 epitaxial thin films,"We measured the temperature dependence of the linear high field Hall
+resistivity of La_0.67Ca_0.33MnO_3 (T_C=232K) and La_0.67Sr_0.33MnO_3
+(T_C=345K) thin films in the temperature range from 4K up to 360K in magnetic
+fields up to 20T. At low temperatures we find a charge carrier density of 1.3
+and 1.4 holes per unit cell for the Ca- and Sr-doped compound, respectively. In
+this temperature range electron-magnon scattering contributes to the
+longitudinal resistivity. At the ferromagnetic transition temperature T_C a
+dramatic drop in the number of current carriers $n$ down to 0.6 holes per unit
+cell, accompanied by an increase in unit cell volume, is observed. Corrections
+of the Hall data due to a non saturated magnetic state will lead a more
+pronounced charge carrier density collapse.",9907346v1
+1999-09-07,Semiclassical Theory of Integrable and Rough Andreev Billiards,"We study the effect on the density of states in mesoscopic ballistic
+billiards to which a superconducting lead is attached. The expression for the
+density of states is derived in the semiclassical S-matrix formalism shedding
+insight into the origin of the differences between the semiclassical theory and
+the corresponding result derived from random matrix models. Applications to a
+square billiard geometry and billiards with boundary roughness are discussed.
+The saturation of the quasiparticle excitation spectrum is related to the
+classical dynamics of the billiard. The influence of weak magnetic fields on
+the proximity effect in rough Andreev billiards is discussed and an analytical
+formula is derived. The semiclassical theory provides an interpretation for the
+suppression of the proximity effect in the presence of magnetic fields as a
+coherence effect of time reversed trajectories, similar to the weak
+localisation correction of the magneto-resistance in chaotic mesoscopic
+systems. The semiclassical theory is shown to be in good agreement with quantum
+mechanical calculations.",9909100v2
+2000-04-12,Small Angle Shubnikov-de Haas Measurements in Silicon MOSFET's: the Effect of Strong In-Plane Magnetic Field,"Measurements in magnetic fields applied at small angles relative to the
+electron plane in silicon MOSFETs indicate a factor of two increase of the
+frequency of Shubnikov-de Haas oscillations at H>H_{sat}. This signals the
+onset of full spin polarization above H_{sat}, the parallel field above which
+the resistivity saturates to a constant value. For H<H_{sat}, the phase of the
+second harmonic of the oscillations relative to the first is consistent with
+scattering events that depend on the overlap instead of the sum of the spin-up
+and spin-down densities of states.",0004201v2
+2000-05-16,Magnetic fluctuations in 2D metals close to the Stoner instability,"We consider the effect of potential disorder on magnetic properties of a
+two-dimensional metallic system (with conductance $g\gg 1$) when interaction in
+the triplet channel is so strong that the system is close to the threshold of
+the Stoner instability. We show, that under these conditions there is an
+exponentially small probability for the system to form local spin droplets
+which are local regions with non zero spin density. Using a non-local version
+of the optimal fluctuation method we find analytically the probability
+distribution and the typical spin of a local spin droplet (LSD). In particular,
+we show that both the probability to form a LSD and its typical spin are
+independent of the size of the droplet (within the exponential accuracy). The
+LSDs manifest themselves in temperature dependence of observable quantities. We
+show, that below certain cross-over temperature the paramagnetic susceptibility
+acquires the Curie-like temperature dependence, while the dephasing time
+(extracted from magneto-resistance measurements) saturates.",0005267v1
+2000-06-30,Off equilibrium properties of vortex creep in superconductors,"We study a model for the dynamics of vortices in type II superconductors. In
+particular, we discuss glassy ``off equilibrium'' properties and ``aging'' in
+magnetic creep. At low temperatures a crossover point is found, Tg, where
+relaxation times seem to diverge a' la Vogel-Tamman-Fulcher. Magnetic creep
+changes by crossing Tg: above Tg power law creep is found asymptotically
+followed by stretched exponential saturation; below Tg the creep is logarithmic
+and vortex motion strongly subdiffusive. In this region violation of time
+translation invariance is found along with important dynamical scaling
+properties. A thermodynamic glassy transition point can be found at a lower
+temperature Tc.",0006491v2
+2000-07-14,Cationic ordering control of magnetization in Sr2FeMoO6 double perovskite,"The role of the synthesis conditions on the cationic Fe/Mo ordering in
+Sr2FeMoO6 double perovskite is addressed. It is shown that this ordering can be
+controlled and varied systematically. The Fe/Mo ordering has a profound impact
+on the saturation magnetization of the material. Using the appropriate
+synthesis protocol a record value of 3.7muB/f.u. has been obtained. Mossbauer
+analysis reveals the existence of two distinguishable Fe sites in agreement
+with the P4/mmm symmetry and a charge density at the Fe(m+) ions significantly
+larger than (+3) suggesting a Fe contribution to the spin-down conduction band.
+The implications of these findings for the synthesis of Sr2FeMoO6 having
+optimal magnetoresistance response are discussed.",0007248v1
+2001-08-19,Optical Pumping in Ferromagnet-Semiconductor Heterostructures: Magneto-optics and Spin Transport,"Epitaxial ferromagnetic metal - semiconductor heterostructures are
+investigated using polarization-dependent electroabsorption measurements on
+GaAs p-type and n-type Schottky diodes with embedded In1-xGaxAs quantum wells.
+We have conducted studies as a function of photon energy, bias voltage,
+magnetic field, and excitation geometry. For optical pumping with circularly
+polarized light at energies above the band edge of GaAs, photocurrents with
+spin polarizations on the order of 1 % flow from the semiconductor to the
+ferromagnet under reverse bias. For optical pumping at normal incidence, this
+polarization may be enhanced significantly by resonant excitation at the
+quantum well ground-state. Measurements in a side-pumping geometry, in which
+the ferromagnet can be saturated in very low magnetic fields, show hysteresis
+that is also consistent with spin-dependent transport. Magneto-optical effects
+that influence these measurements are discussed.",0108292v1
+2001-08-31,Inversion Phenomena of the Anisotropies of the Hamiltonian and the Wave-Function in the Distorted Diamond Type Spin Chain,"We investigate the ground-sate phase diagram of the XXZ version of the S=1/2
+distorted diamond chain by use of the degenerate perturbation theory near the
+truncation point. In case of the XY-like interaction anisotropy, the phase
+diagram consists of the Neel phase and the spin-fluid phase. For the Ising-like
+interaction anisotropy case, it consists of three phases: the ferrimagnetic
+phase, the Neel phase and the spin-fluid phase. The magnetization in the
+ferrimagnetic phase is 1/3 of the saturation magnetization. The remarkable
+nature of the phase diagram is the existence of the Neel phase, although the
+interaction anisotropy is XY-like. And also, the spin-fluid phase appears in
+spite of the Ising-like interaction anisotropy. We call these regions
+""inversion regions"".",0108528v1
+2001-11-27,Light and electric field control of ferromagnetism in magnetic quantum structures,"A strong influence of illumination and electric bias on the Curie temperature
+and saturation value of the magnetization is demonstrated for semiconductor
+structures containing a modulation-doped p-type Cd0.96Mn0.04Te quantum well
+placed in various built-in electric fields. It is shown that both light beam
+and bias voltage generate an isothermal and reversible cross-over between the
+paramagnetic and ferromagnetic phases, in the way that is predetermined by the
+structure design. The observed behavior is in quantitative agreement with the
+expectations for systems, in which ferromagnetic interactions are mediated by
+the weakly disordered two-dimensional hole liquid.",0111511v2
+2001-12-18,Effects of a Parallel Magnetic Field on the Metal-Insulator Transition in a Dilute Two-Dimensional Electron System,"The temperature dependence of conductivity $\sigma (T)$ of a two-dimensional
+electron system in silicon has been studied in parallel magnetic fields B. At
+B=0, the system displays a metal-insulator transition at a critical electron
+density $n_c(0)$, and $d\sigma/dT >0$ in the metallic phase. At low fields
+($B\lesssim 2$ T), $n_c$ increases as $n_c(B) - n_c(0) \propto B^{\beta}$
+($\beta\sim 1$), and the zero-temperature conductivity scales as $\sigma
+(n_s,B,T=0)/\sigma (n_s,0,0)=f(B^{\beta}/\delta_n)$ (where
+$\delta_n=(n_s-n_c(0))/n_c(0)$, and $n_s$ is electron density) as expected for
+a quantum phase transition. The metallic phase persists in fields of up to 18
+T, consistent with the saturation of $n_c$ at high fields.",0112344v2
+2001-12-27,The longitudinal spin relaxation of 2D electrons in Si/SiGe quantum wells in a magnetic field,"The longitudinal spin relaxation time, T1, in a Si/SiGe quantum well is
+determined from the saturation of the ESR signal. We find values of a few
+microseconds. Investigations of T1 as a function of Fermi energy, concentration
+of scattering centers and of the momentum scattering time lead to the
+conclusion that for high electron mobility the spin relaxation is ruled by the
+Dyakonov-Perel (DP) mechanism while for low mobility the Elliott-Yaffet
+mechanism dominates. The DP relaxation is caused by Bychkov-Rashba coupling.
+Evaluation of the DP mechanism shows that 1/T1 for high electron mobility can
+be effectively reduced by an external magnetic field. The effect of the
+degenerate Fermi-Dirac statistics on the DP process is discussed.",0112466v1
+2002-01-26,"Unconventional carrier-mediated ferromagnetism above room temperature in ion-implanted (Ga, Mn)P:C","Ion implantation of Mn ions into hole-doped GaP has been used to induce
+ferromagnetic behavior above room temperature for optimized Mn concentrations
+near 3 at.%. The magnetism is suppressed when the Mn dose is increased or
+decreased away from the 3 at.% value, or when n-type GaP substrates are used.
+At low temperatures the saturated moment is on the order of one Bohr magneton,
+and the spin wave stiffness inferred from the Bloch-law T^3/2 dependence of the
+magnetization provides an estimate Tc = 385K of the Curie temperature that
+exceeds the experimental value, Tc = 270K. The presence of ferromagnetic
+clusters and hysteresis to temperatures of at least 330K is attributed to
+disorder and proximity to a metal-insulating transition.",0201492v1
+2002-04-08,Phase diagram and critical properties of the frustrated Kondo necklace model in a magnetic field,"The critical properties of the frustrated Kondo necklace model with a half
+saturation magnetization ($m=1/2$) have been studied by means of an
+exact-diagonalization method. It is shown from bosonization technique that the
+model can be effectively expressed as a quantum sine-Gordom model. Thus it may
+show three (dimer plateau, N{\'e}el plateau and Tomonaga-Luttinger liquid)
+phases due to competitions among the Ising anisotropy $\Delta$, and the
+nearest- and next-nearest-neighbor exchange interactions $J_1$ and $J_2$. The
+boundary lines on the $\Delta-J_2/J_1$ phase diagram separating the three
+phases are determined by the method of level spectroscopy based on the
+conformal field theory.",0204174v3
+2002-04-11,"Saturated Ferromagnetism and Magnetization Deficit in Optimally Annealed (Ga,Mn)As Epilayers","We examine the Mn concentration dependence of the electronic and magnetic
+properties of optimally annealed Ga1-xMnxAs epilayers for 1.35% < x < 8.3%. The
+Curie temperature (Tc), conductivity, and exchange energy increase with Mn
+concentration up to x ~ 0.05, but are almost constant for larger x, with Tc ~
+110 K. The ferromagnetic moment per Mn ion decreases monotonically with
+increasing x, implying that an increasing fraction of the Mn spins do not
+participate in the ferromagnetism. By contrast, the derived domain wall
+thickness, an important parameter for device design, remains surprisingly
+constant.",0204250v1
+2002-04-16,Magnetic studies of Ca1-xMxRuO3 (M=La and Sr),"CaRuO3 is a perovskite with an orthorhombic distortion and shows the
+characteristics of spin-glass behavior below TC=87 K. The La3+ substitution for
+Ca2+ in Ca1-xLaxRuO3 samples, induces a disorder in the Ca site (the A site)
+and the system becomes antiferromagnetically (AFM) ordered with TN = 58 and 19
+K for x=0.1 x=0.5 respectively. In the Ca1-xSrxRuO3 system, the Ca0.8Sr0.2RuO3
+sample is canted-AFM ordered at 107 K. The compounds with higher Sr
+concentration display ferromagnetic behavior and the saturation moment
+increases with Sr. Huge magnetic hysteresis loops are obtained at low
+temperatures. The coercive field (HC) decreases with Sr. For x=0.4 HC =9.5 kOe
+(at 5 K) whereas for SrRuO3 HC =2.4 kOe. For x=0.4 and 0.6, HC decreases
+sharply with temperature and than increases again with a peak at 95 and 115 K,
+respectively. On the other hand, for SrRuO3, HC remains practically unchanged
+up to 50 K and shows a peak at 90 K and than decrease sharply up to TC =165 K.",0204341v1
+2002-05-12,Magnetic field - temperature phase diagram of quasi-two-dimensional organic superconductor lambda-(BETS)_2 GaCl_4 studied via thermal conductivity,"The thermal conductivity kappa of the quasi-two-dimensional (Q2D) organic
+superconductor lambda-(BETS)_2 GaCl_4 was studied in the magnetic field H
+applied parallel to the Q2D plane. The phase diagram determined from this bulk
+measurement shows notable dependence on the sample quality. In dirty samples
+the upper critical field H_{c2} is consistent with the Pauli paramagnetic
+limiting, and a sharp change is observed in kappa(H) at H_{c2 parallel}. In
+contrast in clean samples H_{c2}(T) shows no saturation towards low
+temperatures and the feature in kappa(H) is replaced by two slope changes
+reminiscent of second-order transitions. The peculiarity was observed below ~
+0.33T_c and disappeared on field inclination to the plane when the orbital
+suppression of superconductivity became dominant. This behavior is consistent
+with the formation of a superconducting state with spatially modulated order
+parameter in clean samples.",0205239v2
+2002-08-03,Formation of Co nanoclusters in epitaxial Ti_{0.96} Co_{0.04} O_2 thin films and their ferromagnetism,"Anatase Ti0.96Co0.04O2 films were grown epitaxially on SrTiO3 (001)
+substrates by using plused laser deposition with in-situ reflection high-energy
+electron diffraction. The oxygen partial pressure, PO2, during the growth was
+systematically varied. As PO2 decreased, the growth behavior was changed from a
+2-dimensional layer-by-layer-like growth to a 3-dimensional island-like one,
+which resulted in an increase in the saturation magnetization. These structural
+and magnetic changes were explained in terms of the formation of cobalt
+clusters whose existence was proved by transmission-electron-microscopie
+studies. Our work clearly indicates that the cobalt clustering will cause
+room-temperature ferromagnetism in the Co-doped TiO2 films.",0208055v1
+2002-08-30,Nickel Antidot Arrays on Anodic Alumina Substrates,"Large area nickel antidot arrays with density up to 10^10 /cm^2 have been
+fabricated by depositing nickel onto anodic aluminum oxide membranes that
+contain lattices of nanopores. Electron microscopy images show a high degree of
+order of the antidot arrays. Various sizes and shapes of the antidots were
+observed with increasing thickness of the deposited nickel. New features appear
+in the antidot arrays in both magnetization and transport measurements when the
+external magnetic field is parallel to the current direction, including an
+enhancement and a nonmonotonous field dependence of the magnetoresistance,
+larger values of the coercive field and remanence moment, and smaller
+saturation field.",0208608v2
+2002-11-14,"Preparation and structural properties of thin films and multilayers of the Heusler compounds Cu2MnAl, Co2MnSn, Co2MnSi and Co2MnGe","We report on the preparation of thin films and multilayers of the
+intermetallic Heusler compound CuMnAl, Co2MnSn, Co2MnSi and Co2MnGe by
+rf-sputtering on MgO and Al2O3 substrates. Cu2MnAl can be grown epitaxially
+with (100)-orientation on MgO (100) and in (110)-orientation on Al2O3 a-plane.
+The Co based Heusler alloys need metallic seedlayers to induce high quality
+textured growth. We also have prepared multilayers with smooth interfaces by
+combining the Heusler compounds with Au and V. An analysis of the ferromagnetic
+saturation magnetization of the films indicates that the Cu2MnAl-compound tends
+to grow in the disordered B2-type structure whereas the Co-based Heusler alloy
+thin films grow in the ordered L21 structure. All multilayers with thin layers
+of the Heusler compounds exhibit a definitely reduced ferromagnetic
+magnetization indicating substantial disorder and intermixing at the
+interfaces.",0211271v1
+2003-02-21,Field-induced XY behavior in the S=1/2 antiferromagnet on the square lattice,"Making use of the quantum Monte Carlo method based on the worm algorithm, we
+study the thermodynamic behavior of the S=1/2 isotropic Heisenberg
+antiferromagnet on the square lattice in a uniform magnetic field varying from
+very small values up to the saturation value. The field is found to induce a
+Berezinskii-Kosterlitz-Thouless transition at a finite temperature, above which
+a genuine XY behavior in an extended temperature range is observed. The phase
+diagram of the system is drawn, and the thermodynamic behavior of the specific
+heat and of the uniform and staggered magnetization is discussed in sight of an
+experimental investigation of the field-induced XY behavior.",0302440v1
+2003-06-04,Impurity Effects on the A_1-A_2 Splitting of Superfluid 3He in Aerogel,"When liquid 3He is impregnated into silica aerogel a solid-like layer of 3He
+atoms coats the silica structure. The surface 3He is in fast exchange with the
+liquid on NMR timescales. The exchange coupling of liquid 3He quasiparticles
+with the localized 3He spins modifies the scattering of 3He quasiparticles by
+the aerogel structure. In a magnetic field the polarization of the solid spins
+gives rise to a splitting of the scattering cross-section of for `up' vs.
+`down' spin quasiparticles, relative to the polarization of the solid 3He. We
+discuss this effect, as well as the effects of non-magnetic scattering, in the
+context of a possible splitting of the superfluid transition for
+$\uparrow\uparrow$ vs. $\downarrow\downarrow$ Cooper pairs for superfluid 3He
+in aerogel, analogous to the A_1-A_2 splitting in bulk 3He. Comparison with the
+existing measurements of T_c for B< 5 kG, which show no evidence of an A_1-A_2
+splitting, suggests a liquid-solid exchange coupling of order J = 0.1 mK.
+Measurements at higher fields, B > 20 kG, should saturate the polarization of
+the solid 3He and reveal the A_1-A_2 splitting.",0306099v1
+2003-07-21,Study of an Antiferromagnetic Sawtooth Chain with Spin-1/2 and Spin-1 sites,"We study the low-energy properties of a sawtooth chain with spin-1's at the
+bases of the triangles and spin-1/2's at the vertices of the triangles. The
+spins have Heisenberg antiferromagnetic interactions between nearest neighbors,
+with a coupling J_2 between a spin-1 and a spin-1/2, and a coupling J_1 = 1
+between two spin-1's. Analysis of the exact diagonalization data for periodic
+chains containing up to N=12 unit cells shows that the ground state is a
+singlet for exchange couplings up to approximately J_2 = 3.8, whereas for
+larger J_2, the system exhibits a ferrimagnetic ground state characterized by a
+net ferromagnetic moment per unit cell of 1/2. In the region of small
+interactions J_2, the mixed spin sawtooth chain maps on to an effective
+isotropic spin model representing two weakly interacting and frustrated
+spin-1/2 Heisenberg chains composed of spin-1/2 sites at odd and even vertices
+respectively. Finally, we study the phenomenon of a macroscopic magnetization
+jump which occurs if a magnetic field is applied with a value close to the
+saturation field for J_2 = 2.",0307492v1
+2004-01-03,History-Induced Critical Behavior in Disordered Systems,"Barkhausen noise as found in magnets is studied both with and without the
+presence of long-range (LR) demagnetizing fields using the non-equilibrium,
+zero-temperature random-field Ising model. Two distinct subloop behaviors arise
+and are shown to be in qualitative agreement with experiments on thin film
+magnets and soft ferromagnets. With LR fields present subloops resemble a
+self-organized critical system, while their absence results in subloops that
+reflect the critical point seen in the saturation loop as the system disorder
+is changed. In the former case, power law distributions of noise are found in
+subloops, while in the latter case history-induced critical scaling is studied
+in avalanche size distributions, spin-flip correlation functions, and
+finite-size scaling of the second moments of the size distributions. Results
+are presented for simulations of over 10^8 spins.",0401023v1
+2004-07-22,Levitation of the quantum Hall extended states in the $B\to$ 0 limit,"We investigate the fate of the quantum Hall extended states within a
+continuum model with spatially correlated disorder potentials. The model can be
+projected onto a couple of the lowest Landau bands. Levitation of the $n=0$
+critical states is observed if at least the two lowest Landau bands are
+considered. The dependence on the magnetic length $l_B=(\hbar/(eB))^{1/2}$ and
+on the correlation length of the disorder potential $\eta$ is combined into a
+single dimensionless parameter $\hat\eta=\eta/l_B$. This enables us to study
+the behavior of the critical states for vanishing magnetic field. In the two
+Landau band limit, we find a disorder dependent saturation of the critical
+states' levitation which is in contrast to earlier propositions, but in accord
+with some experiments.",0407584v2
+2004-11-26,Room-temperature ferromagnetism in Sr_(1-x)Y_xCoO_(3-delta) (0.2 < x < 0.25),"We have measured magnetic susceptibility and resistivity of
+Sr$_{1-x}$Y$_x$CoO$_{3-\delta}$ ($x=$ 0.1, 0.15, 0.2, 0.215, 0.225, 0.25, 0.3,
+and 0.4), and have found that Sr$_{1-x}$Y$_x$CoO$_{3-\delta}$ is a room
+temperature ferromagnet with a Curie temperature of 335 K in a narrow
+compositional range of 0.2 $\leq x\leq$ 0.25. This is the highest transition
+temperature among perovskite Co oxides. The saturation magnetization for $x=$
+0.225 is 0.25 $\mu_B$/Co at 10 K, which implies that the observed
+ferromagnetism is a bulk effect. We attribute this ferromagnetism to a peculiar
+Sr/Y ordering.",0411671v3
+2004-11-28,Disorder-induced microscopic magnetic memory,"Using coherent x-ray speckle metrology, we have measured the influence of
+disorder on major loop return point memory (RPM) and complementary point memory
+(CPM) for a series of perpendicular anisotropy Co/Pt multilayer films. In the
+low disorder limit, the domain structures show no memory with field cycling--no
+RPM and no CPM. With increasing disorder, we observe the onset and the
+saturation of both the RPM and the CPM. These results provide the first direct
+ensemble-sensitive experimental study of the effects of varying disorder on
+microscopic magnetic memory and are compared against the predictions of
+existing theories.",0411698v1
+2004-12-13,Quantum interference of electrons in Nb_{5-δ}Te_4 single crystals,"The compound $Nb_{5-\delta}Te_4$ ($\delta=0.23$) with quasi-one-dimensional
+crystal structure undergoes a transition to superconductivity at $T_c$=0.6--0.9
+K. Its electronic transport properties in the normal state are studied in the
+temperature range 1.3--270 K and in magnetic fields up to 11 T. The temperature
+variation of the resistivity is weak ($<2%$) in the investigated temperature
+range. Nonmonotonic behavior of the resistivity is observed which is
+characterized by two local maxima at $T\sim$2 K and $\sim$30 K. The temperature
+dependence of the resistivity is interpreted as an interplay of weak
+localization, weak antilocalization, and electron-electron interaction effects
+in the diffusion and the Cooper channel. The temperature dependence of the
+dephasing time $\tau_\phi$ extracted from the magnetoresistance data is
+determined by the electron-phonon interaction. The saturation of $\tau_\phi$ in
+the low-temperature limit correlates with $T_c$ of the individual crystal and
+is ascribed to the scattering on magnetic impurities.",0412315v1
+2005-04-22,Possible Localization Behavior of the Inherent Conducting Polymer (CH$_3$)$_{0.9}$ReO$_3$,"Polymeric methyltrioxorhenium (poly-MTO) represents the first example of an
+inherent conducting organometallic oxide. It adopts the structural motives and
+transport properties of some classical perovskites in two dimensions. In this
+study we present resistivity data down to 30 mK which exhibit a crossover from
+a metallic (d$\rho$/d$T >$ 0) to an insulating (d$\rho$/d$T <$ 0) behavior at
+about 30 K. Below 30 K an unusual resistivity behavior, similar to that of some
+doped cuprate systems, is observed: initially the resistivity increases
+approximately as $\rho \sim$ log$(1/T$) before it starts to saturate below 2 K.
+Furthermore, a linear positive magnetoresistance is found (up to 7 T).
+Temperature dependent magnetization and specific heat measurements in various
+magnetic fields indicate that the unusual resistivity behavior may be driven by
+spatial localization of the d$^1$ moments at the Re atoms.",0504585v1
+2005-04-27,Effect of toroidal moment on a macroscopic self-organization of electrons in the quantum Hall regime,"We have studied CR lineshape of terahertz-light-induced current in InAs
+quantum wells in tilted quantizing magnetic fields. We have observed dramatic
+modification of the lineshape with increasing of in-plane component of magnetic
+field as well as with increasing of transverse built-in electric field in the
+well. Scenario of the modification shows that the energy spectrum asymmetry is
+determined by so-called toroidal moment of the system and is a function of
+Landau quantum number. Macroscopic self-organization of electrons under the
+conditions of quantum Hall effect has also been directly demonstrated in both
+linear and saturation regimes of the light absorption.",0504720v1
+2005-07-30,Specific Heat Study on a Novel Spin-Gapped System : (CH_3)_2NH_2CuCl_3,"Specific heat measurements down to 120mK have been performed on a
+quasi-one-dimensional $S=1/2$ spin-gapped system (CH$_3$)$_2$NH$_2$CuCl$_3$ in
+a magnetic field up to 8 T. This compound has a characteristic magnetization
+curve which shows a gapless ground state and a plateau at 1/2 of the saturation
+value. We have observed a spontaneous antiferromagnetic ordering and a
+field-induced one below and above the 1/2 plateau field range, respectively.
+The field versus temperature phase diagram is quite unusual and completely
+different from those of the other quantum spin systems investigated so far. In
+the plateau field range, a double-structure in the specific heat is observed,
+reflecting the coexistence of ferromagnetic and antiferromagnetic excitations.
+These behaviors are discussed on the basis of a recently proposed novel quantum
+spin chain model consisting of weakly coupled ferromagnetic and
+antiferromagnetic dimers.",0508007v1
+2005-09-27,Antiferromagnetic ordering in heavy fermion system Ce2Au2Cd,"La2Au2Cd and Ce2Au2Cd were prepared from the elements by reactions in sealed
+tantalum tubes in a water-cooled sample chamber of an induction furnace. These
+intermetallics crystallize with the tetragonal Mo2FeB2 type, space group
+P4/mbm. While La2Au2Cd is Pauli paramagnetic, Ce2Au2Cd shows Curie-Weiss
+behaviour above 100 K with an experimental magnetic moment of 2.41(2) muB/Ce
+atom, indicating trivalent cerium. Antiferromagnetic ordering is detected for
+Ce2Au2Cd at 5.01(2) K and magnetization measurements reveal a metamagnetic
+transition at 3 K at a critical field of around 20 kOe with a saturation moment
+of 1.50(2)muB/Ce atom at 80 kOe. The low-temperature heat capacity properties
+characterize Ce2Au2Cd as a heavy fermion material with an electronic specific
+heat coefficient (gamma) = 807(5) mJ/mol K2 as compared to La2Au2Cd with gamma
+= 6(5) mJ/mol K2.",0509703v2
+2005-10-07,Quantum effects in a half-polarized pyrochlore antiferromagnet,"We study quantum effects in a spin-3/2 antiferromagnet on the pyrochlore
+lattice in an external magnetic field, focusing on the vicinity of a plateau in
+the magnetization at half the saturation value, observed in CdCr$_2$O$_4$, and
+HgCr$_2$O$_4$. Our theory, based on quantum fluctuations, predicts the
+existence of a symmetry-broken state on the plateau, even with only
+nearest-neighbor microscopic exchange. This symmetry broken state consists of a
+particular arrangement of spins polarized parallel and antiparallel to the
+field in a 3:1 ratio on each tetrahedron. It quadruples the lattice unit cell,
+and reduces the space group from $Fd\bar{3}m$ to $P4_332$. We also predict that
+for fields just above the plateau, the low temperature phase has transverse
+spin order, describable as a Bose-Einstein condensate of magnons. Other
+comparisons to and suggestions for experiments are discussed.",0510202v1
+2005-12-15,Nematic order in square lattice frustrated ferromagnets,"We present a new scenario for the breakdown of ferromagnetic order in a
+two-dimensional quantum magnet with competing ferromagnetic and
+antiferromagnetic interactions. In this, dynamical effects lead to the
+formation of two-magnon bound states, which undergo Bose-Einstein condensation,
+giving rise to bond-centered nematic order. This scenario is explored in some
+detail for an extended Heisenberg model on a square lattice. In particular, we
+present numerical evidence confirming the existence of a state with d-wave
+nematic correlations but no long range magnetic order, lying between the
+saturated ferromagnetic and collinear antiferromagnetic phases of the
+ferromagnetic J1-J2 model. We argue by continuity of spectra that this phase is
+also present in a model with 4-spin cyclic exchange.",0512349v1
+2006-01-16,"Selective dilution and magnetic properties of La_{0.7}Sr_{0.3}Mn_{1-x}M'_xO_3 (M' = Al, Ti)","The magnetic lattice of mixed-valence Mn ions in La$_{0.7}$Sr$_{0.3}$MnO$_3$
+is selectively diluted by partial substitution of Mn by Al or Ti. The
+ferromagnetic transition temperature and the saturation moment decreases with
+substitution in both series. The volume fraction of the non-ferromagnetic
+phases evolves non-linearly with the substitution concentration and faster than
+theoretically expected. By presenting the data in terms of selective dilutions,
+the reduction of $T_\mathrm{c}$ is found to be scaled by the relative ionic
+concentrations and is consistent with a prediction derived from molecular-field
+theory.",0601308v1
+2006-02-04,Compensation of Effective Field in the Field-Induced Superconductor k-(BETS)2FeBr4 Observed by 77Se NMR,"We report results of 77Se NMR frequency shift in the normal state of the
+organic charge-transfer-salt k-(BETS)2FeBr4 which shows magnetic field-induced
+superconductivity (FISC). From a simple mean field analysis, we determined the
+field and the temperature dependences of the magnetization m_{pi} of the \pi
+conduction electrons on BETS molecules. We found that the Fe spins are
+antiferromagnetically coupled to the pi electrons and determined the exchange
+field to be J = -2.3T/mu_B. The exchange field from the fully saturated Fe
+moments (5 mu_B) is compensated by an external field of 12T. This is close to
+the central field of the FISC phase, consistent with the Jaccarino-Peter local
+field-compensation mechanism for FISC (Phys. Rev. Lett. 9, 290 (1962)).",0602099v1
+2006-02-07,Field-Induced Ferromagnetic Order and Colossal Magnetoresistance in La_{1.2}Sr_{1.8}Mn_2O_7: a ^{139}La NMR study,"In order to gain insights into the origin of colossal magneto-resistance
+(CMR) in manganese oxides, we performed a ^{139}La NMR study in the
+double-layered compound La_{1.2}Sr_{1.8}Mn_2O_7. We find that above the Curie
+temperature T_C=126 K, applying a magnetic field induces a long-range
+ferromagnetic order that persists up to T=330 K. The critical field at which
+the induced magnetic moment is saturated coincides with the field at which the
+CMR effect reaches to a maximum. Our results therefore indicate that the CMR
+observed above T_C in this compound is due to the field-induced ferromagnetism
+that produces a metallic state via the double exchange interaction.",0602161v1
+2006-02-09,Anisotropic magnetoresistance and anisotropic tunneling magnetoresistance due to quantum interference in ferromagnetic metal break junctions,"We measure the low-temperature resistance of permalloy break junctions as a
+function of contact size and the magnetic field angle, in applied fields large
+enough to saturate the magnetization. For both nanometer-scale metallic
+contacts and tunneling devices we observe large changes in resistance with
+angle, as large as 25% in the tunneling regime. The pattern of
+magnetoresistance is sensitive to changes in bias on a scale of a few mV. We
+interpret the effect as a consequence of conductance fluctuations due to
+quantum interference.",0602251v2
+2006-04-07,Possibility of field-induced incommensurate order in quasi-one-dimensional frustrated spin system,"We study an incommensurate long-range order induced by an external magnetic
+field in a quasi-one-dimensional bond-alternating spin system, F5PNN, focusing
+on the role of the frustrating interaction which can be enhanced by a
+high-pressure effect. On the basis of the density matrix renormalization group
+analysis of a microscopic model for F5PNN, we present several H-T phase
+diagrams for typical parameters of the frustrating next-nearest-neighbour
+coupling and the interchain interaction, and then discuss how the field-induced
+incommensurate order develops by the frustration effect in such phase diagrams.
+A magnetization plateau at half the saturation moment is also mentioned.",0604194v1
+2006-05-21,High-temperature ferromagnetism of $sp$ electrons in narrow impurity bands: Application to CaB$_6$,"Ferromagnetism with high Curie temperature $T_c$, well above room
+temperature, and very small saturation moment has been reported in various
+carbon and boron systems. It is argued that the magnetization must be very
+inhomogeneous with only a small fraction of the sample ferromagnetically
+ordered. It is shown that a possible source of high $T_c$ within the
+ferromagnetic regions is itinerant electrons occupying a narrow impurity band.
+Correlation effects do not reduce the effective interaction which enters the
+Stoner criterion in the same way as in a bulk band. It is also shown how, in
+the impurity band case, spin wave excitations may not be effective in lowering
+$T_c$ below its value given by Stoner theory. These ideas are applied to
+CaB$_6$ and a thorough review of the experimental situation in this material is
+given. It is suggested that the intrinsic magnetism of the B$_2$ and O$_2$
+dimers might be exploited in suitable structures containing these elements.",0605495v1
+2006-06-13,Electron-Dephasing Time in A Two-Dimensional Spin-Polarized System with Rashba Spin-Orbit Interaction,"We calculate the dephasing time $\tau_{\phi}(B)$ of an electron in a
+two-dimensional quantum well with a Rashba spin-orbit interaction,
+spin-polarized by an arbitrarily large magnetic field parallel to the layer.
+$\tau_\phi (B)$ is estimated from the logarithmic corrections to the
+conductivity, within a perturbative approach, that assumes weak isotropic
+disorder scattering. Our result indicates that for any value of the magnetic
+field, the dephasing rate changes with respect to its unpolarized state value
+by a universal function whose parameter is the ratio of the Zeeman splitting
+energy $(E_Z)$ to the spin-orbit interaction $(E_{SOI})$, confirming the
+experimental report published in Phys. Rev. Lett. {\bf 94}, 186805 (2005) . In
+the high field limit, when $E_Z>>E_{SOI}$, the dephasing rate saturates and
+reaches asymptotically to a value equal to twice the spin relaxation rate.",0606328v2
+2006-06-21,Evidence of s-Wave Subdominant Order Parameter in YBCO from Break Junction Tunneling Spectra,"The tunneling spectra of YBa2Cu3O7 break-junctions have been investigated for
+the tunneling direction close to the node one. The zero-bias conductance peak
+(ZBCP) and Josephson current have been studied with temperature and magnetic
+field. The observed deep splitting of ZBCP which starts at Ts<20-30K is in
+agreement with the theory for the dx2-y2+-is order parameter [Y. Tanuma, Y.
+Tanaka, and S. Kashiwaya, Phys. Rev. B 64, 214519 (2001)]. The low (0.04T)
+magnetic field depresses significantly such splitting. The 1/T temperature
+dependence of maximum Josephson current goes to saturation at T<Ts also
+confirming the mixed order parameter formation.",0606552v2
+2006-08-07,"Growth, Structure and Properties of Epitaxial Thin Films of First Principles Predicted Multiferroic Bi2FeCrO6","We report the structural and physical properties of epitaxial Bi2FeCrO6 thin
+films on epitaxial SrRuO3 grown on (100)-oriented SrTiO3 substrates by pulsed
+laser ablation. The 300 nm thick films exhibit both ferroelectricity and
+magnetism at room temperature with a maximum dielectric polarization of 2.8
+microC/cm2 at Emax = 82 kV/cm and a saturated magnetization of 20 emu/cc
+(corresponding to ~ 0.26 Bohr magneton per rhombohedral unit cell), with
+coercive fields below 100 Oe. Our results confirm the predictions made using
+ab-initio calculations about the existence of multiferroic properties in
+Bi2FeCrO6.",0608178v1
+2006-08-14,Electronic and Magnetic Properties of Mn doped Ge Nanowires,"Using {\it ab initio} total energy density-functional theory calculations, we
+investigate the electronic, structural and magnetic properties of Manganese
+doped Germanium nanowires. The nanowires have been constructed along the [110]
+direction and the dangling bonds on the surface have been saturated by hydrogen
+atoms. We observed that the Mn has lower formation energy at the center of the
+wire when compared to regions close to the surface. The Mn-Mn coupling has
+lower energy for a high-spin configuration except when they are first nearest
+neighbors. These results show that Ge:Mn nanowires are potential candidates for
+ferromagnetic quasi-one dimentional systems.",0608315v2
+2006-11-09,New ultrasmall iron-oxide nanoparticles with high magnetisation as potential T1-MRI contrast agents for Molecular Imaging,"Here we report on the synthesis of very small gamma-Fe2O3 nanoparticles (5
+nm) presenting very narrow particle size distribution and exceptionally high
+saturation magnetisation. The synthesis has been carried out in an organic
+medium with subsequent transfer to an aqueous solution at physiological pH. The
+structural and magnetic properties were kept unaltered after the solvent
+exchange. NMR relaxometric measurements show the potential of these particles
+as specific reporters for magnetic resonance molecular imaging.",0611243v1
+2006-12-24,Structural and magnetic properties of Mn-implanted Si,"Structural and ferromagnetic properties in Mn implanted, p-type Si were
+investigated. High resolution structural analysis techniques like synchrotron
+X-ray diffraction revealed the formation of MnSi1.7 nanoparticles already in
+the as implanted samples. Depending on the Mn-fluence, the size increases from
+5 nm to 20 nm upon rapid thermal annealing. No significant evidence is found
+for Mn substituting Si sites either in the as-implanted or annealed samples.
+The observed ferromagnetism yields a saturation moment of 0.21 mu_B per
+implanted Mn at 10 K, which could be assigned to MnSi1.7 nanoparticles as
+revealed by a temperature dependent magnetization measurement.",0612612v1
+2007-03-19,Enhanced magnetocaloric effect in frustrated magnetic molecules with icosahedral symmetry,"We investigate the magnetocaloric properties of certain antiferromagnetic
+spin systems that have already been or very likely can be synthesized as
+magnetic molecules. It turns out that the special geometric frustration which
+is present in antiferromagnets that consist of corner-sharing triangles leads
+to an enhanced magnetocaloric effect with high cooling rates in the vicinity of
+the saturation field. These findings are compared with the behavior of a simple
+unfrustrated spin ring as well as with the properties of the icosahedron. To
+our surprise, also for the icosahedron large cooling rates can be achieved but
+due to a different kind of geometric frustration.",0703480v1
+2001-11-23,Dimming Supernovae without Cosmic Acceleration,"We present a simple model where photons propagating in extra-galactic
+magnetic fields can oscillate into very light axions. The oscillations may
+convert some of the photons departing a distant supernova into axions, making
+the supernova appear dimmer and hence more distant than it really is. Averaging
+over different configurations of the magnetic field we find that the dimming
+saturates at about 1/3 of the light from the supernovae at very large
+redshifts. This results in a luminosity-distance vs. redshift curve almost
+indistinguishable from that produced by the accelerating Universe, if the axion
+mass and coupling scale are m ~ 10^-16 eV, M ~ 4 10^11 GeV. This phenomenon may
+be an alternative to the accelerating Universe for explaining supernova
+observations.",0111311v2
+1995-02-16,STATIC FOUR-DIMENSIONAL ABELIAN BLACK HOLES IN KALUZA-KLEIN THEORY,"Static, four-dimensional (4-d) black holes (BH's) in ($4+n$)-d Kaluza-Klein
+(KK) theory with Abelian isometry and diagonal internal metric have at most one
+electric ($Q$) and one magnetic ($P$) charges, which can either come from the
+same $U(1)$-gauge field (corresponding to BH's in effective 5-d KK theory) or
+from different ones (corresponding to BH's with $U(1)_M\times U(1)_E$ isometry
+of an effective 6-d KK theory). In the latter case, explicit non-extreme
+solutions have the global space-time of Schwarzschild BH's, finite temperature,
+and non-zero entropy. In the extreme (supersymmetric) limit the singularity
+becomes null, the temperature saturates the upper bound
+$T_H=1/4\pi\sqrt{|QP|}$, and entropy is zero. A class of KK BH's with
+constrained charge configurations, exhibiting a continuous electric-magnetic
+duality, are generated by global $SO(n)$ transformations on the above classes
+of the solutions.",9502099v1
+1995-07-18,Dyonic BPS Saturated Black Holes of Heterotic String on a Six-Torus,"Within effective heterotic superstring theory compactified on a six-torus we
+derive minimum energy (supersymmetric), static, spherically symmetric
+solutions, which are manifestly invariant under the target space $O(6,22)$ and
+the strong-weak coupling $SL(2)$ duality symmetries with 28 electric and 28
+magnetic charges subject to one constraint. The class of solutions with a
+constant axion corresponds to dyonic configurations subject to two charge
+constraints, with purely electric [or purely magnetic] and dyonic
+configurations preserving ${1\over 2}$ and ${1\over 4}$ of $N=4$ supersymmetry,
+respectively. General dyonic configurations in this class have a space-time of
+extreme Reissner-Nordstr\"" om black holes while configurations with more
+constrained charges have a null or a naked singularity.",9507090v2
+1996-02-20,Macroscopic Entropy of $N=2$ Extremal Black Holes,"Extremal BPS-saturated black holes in $N=2$, $d=4$ supergravity can carry
+electric and magnetic charges $(q^\Lambda_{(m)},q_\Lambda^{(e)})$. It is shown
+that in smooth cases the moduli fields at the horizon take a fixed ""rational""
+value $X^\Lambda(q_{(m)},q^{(e)})$ which is determined by the charges and is
+independent of the asymptotic values of the moduli fields. A universal formula
+for the Bekenstein-Hawking entropy is derived in terms of the charges and the
+moduli space geometry at $X^\Lambda(q_{(m)},q^{(e)})$. This work extends
+previous results of Ferrara, Kallosh and the author for the pure magnetic case.",9602111v3
+1998-08-12,On Phases of Gauge Theories and the Role of Non-BPS Solitons in Field Theory,"As shown in hep-th/9709081, non-BPS saturated solitons play an important role
+in the duality transformations of N=1 supersymmetric gauge theories. In
+particular, a massive spinor in an SO(N) gauge theory with massless matter in
+the vector representation appears in the dual description as a magnetic
+monopole with a Z_2 charge. This claim is supported by numerous tests,
+including detailed matching of flavor quantum numbers. This fact makes it
+possible to test the phase of an SO(N) gauge theory using massive spinors as a
+probe. It is thereby shown explicitly that the free magnetic phase which
+appears in supersymmetric theories is a non-confining phase. A fully
+non-abelian version of the Dual Meissner effect is also exhibited, in which the
+monopoles are confined by non-BPS string solitons with Z_2 charges.",9808073v1
+2001-04-04,Wave particle duality: Merging de Broglie's ''double solution'' waves into (3+0)D electromagnetic solitons,"The well known light filaments, are obtained in various media whose index of
+refraction increases before a saturation with the electric field; adding a
+small perturbation which increases the index with the magnetic field, and
+neglecting the absorption, a filament curves and closes into a torus. This
+transformation of a (2+1)D soliton into a (3+0)D soliton shows the existence of
+those solitons, while a complete study, with a larger magnetic effect, would
+require numerical computations, the starting point being, possibly, the
+perturbed, curved filament.
+  The flux of energy in the regular filaments is nearly a ''critical flux'',
+depending slightly on the external fields, so that the energy of the (3+0)D
+soliton is quantified, but may be slightly changed by external interactions.
+  The creation of electron positron pairs in the vacuum by purely
+electromagnetic fields shows a nonlinearity of vacuum at high energies;
+supposing this nonlinearity convenient, elementary particles may be (3+0)D
+solitons.
+  Set that the nearly linear part of the soliton is the $\Psi$ wave while the
+remainder, (the torus) is the $u$ wave; if the torus is not absorbed by Young
+slits, it is guided by the transmitted, interfering remainder of the $\Psi$
+wave.",0104007v1
+2001-05-31,Description of collective magnetic states within a spherical single particle basis,"A many body Hamiltonian comprising pairing, quadrupole-quadrupole and
+spin-spin interaction is treated within a projected spherical basis with the
+aim of describing the detailed structure of the magnetic states of orbital and
+spin-flip nature in $^{144, 148-154}$Sm. The mean field for the single particle
+motion takes care of the volume conservation of a phenomenological core which
+results in having a complex dependence on deformation for single particle
+energies. Several experimental features like the total orbital and total spin
+strengths, the shape of the orbital strength distribution, the hump structure
+of the spin strength distribution, the quadratic dependence of the orbital
+strength on nuclear deformation, the saturation effect of the orbital strength
+with respect to the Casten's factor P are very well described within a
+quasiparticle random phase approximation formalism. Comparison of present
+results with those obtained in some previous treatments are also given.",0105078v1
+2003-09-29,An equilibrium model for RFP plasmas in the presence of resonant tearing modes with an application to particle and heat transport,"The equilibrium of a finite-beta cylindrical RFP plasma in the presence of
+saturated-amplitude tearing modes is investigated. The singularities arising
+from the perturbative analysis of the MHD force balance equation JxB=grad(p)
+are resolved through a proper regularization of the cylindrical symmetric
+component of the pressure and parallel current density profiles, by setting to
+zero their gradient at the modes rational surfaces. An equilibrium model, which
+satisfies the regularization rule at the various rational surfaces, is
+developed. The comparison with the experimental data from the Reversed Field
+eXperiment (RFX) gives encouraging results. The model provides an easy tool to
+extrapolate the magnetic data, ordinarily measured only at the plasma edge,
+inside the plasma. As an application, we present the computation of the
+particle and heat stochastic diffusion coefficient from the reconstructed
+magnetic field profile.",0309114v1
+2006-09-14,Comparison between resistive and collisionless double tearing modes for nearby resonant surfaces,"The linear instability and nonlinear dynamics of collisional (resistive) and
+collisionless (due to electron inertia) double tearing modes (DTMs) are
+compared with the use of a reduced cylindrical model of a tokamak plasma. We
+focus on cases where two q = 2 resonant surfaces are located a small distance
+apart. It is found that regardless of the magnetic reconnection mechanism,
+resistivity or electron inertia, the fastest growing linear eigenmodes may have
+high poloidal mode numbers m ~ 10. The spectrum of unstable modes tends to be
+broader in the collisionless case. In the nonlinear regime, it is shown that in
+both cases fast growing high-m DTMs lead to an annular collapse involving small
+magnetic island structures. In addition, collisionless DTMs exhibit multiple
+reconnection cycles due to reversibility of collisionless reconnection and
+strong ExB flows. Collisionless reconnection leads to a saturated stable state,
+while in the collisional case resistive decay keeps the system weakly dynamic
+by driving it back towards the unstable equilibrium maintained by a source
+term.",0609115v4
+2003-10-05,Local entanglement and quantum phase transition in the Hubbard model,"The local entanglement $E_v$ of the one-dimensional Hubbard model is studied
+on the basis of its Bethe-ansatz solution. The relationship between the local
+entanglement and the on-site Coulomb interaction $U$ is obtained. Our results
+show that $E_v$ is an even analytic function of $U$ at half-filling and it
+reaches a maximum at the critical point U=0. The variation of the local
+entanglement with the filling factor shows that the ground state with maximal
+symmetry possesses maximal entanglement. The magnetic field makes the local
+entanglement to decrease and approach to zero at saturated magnetization. The
+on-site Coulomb interaction always suppresses the local entanglement.",0310030v1
+2007-05-02,Effect of temperature-dependent shape anisotropy on coercivity with aligned Stoner-Wohlfarth soft ferromagnets,"The temperature variation effect of shape anisotropy on the coercivity,
+HC(T), for the aligned Stoner-Wohlfarth (SW) soft ferromagnets, such as fcc Ni,
+fcc Co and bcc Fe, are investigated within the framework of Neel-Brown (N-B)
+analysis. An extended N-B equation is thus proposed,by introducing a single
+dimensionless correction function, the reduced magnetization, m(\tao) =
+MS(T)/MS(0), in which \tao = T/TC is the reduced temperature, MS(T) is the
+saturation magnetization, and TC is the Curie temperature. The factor, m(\tao),
+accounts for the temperature-dependent effect of the shape anisotropy. The
+constants, H0 and E0, are for the switching field at zero temperature and the
+potential barrier at zero field, respectively. According to this newly derived
+equation, the blocking temperature above which the properties of
+superparamagnetism show up is described by the expression, TB =
+E0m^2(\tao)/[kBln(t/t0)], with the extra correction factor m^2(\tao). The
+possible effect on HC(T) and the blocking temperature, TB, attributed to the
+downshift of TC resulting from the finite size effect has been discussed also.",0705.0195v1
+2007-05-22,Effect of Mo doping for the Mn site in the ferromagnetic manganite La0.7Ca0.3MnO3,"The structure, electronic, and magnetic properties of the Mo-doped perovskite
+La0.7Ca0.3Mn1-xMoxO3 (x < 0.1) have been studied. A significant increase in
+resistivity and lattice parameters were observed with Mo doping. A marginal
+decrease in the Curie temperature Tc and the associated metal-insulator
+transition Tp were observed. Magnetization data reveal that long-range
+ferromagnetic ordering persists in all samples studied and the saturation
+moment decreases linearly as x increases. Enhancement in magnetoresistance at
+near Tc in the Mo-doped compounds with an optimum doping value x = 0.05 was
+observed. The overall experimental results can be explained by considering the
+induced Mn2+ ions with Mo6+ in the Mo-doped systems, with the strong FM
+coupling between Mn4+/2+- O - Mn3+.",0705.3080v1
+2007-05-22,Charge Transport and Inhomogeneity near the Charge Neutrality Point in Graphene,"The magnetic field-dependent longitudinal and Hall components of the
+resistivity rho_xx(H) and rho_xy(H) are measured in graphene on silicon dioxide
+substrates at temperatures from 1.6 K to room temperature. At charge densities
+near the charge-neutrality point rho_xx(H) is strongly enhanced and rho_xy(H)
+is suppressed, indicating nearly equal electron and hole contributions to the
+transport current. The data are inconsistent with uniformly distributed
+electron and hole concentrations (two-fluid model) but in excellent agreement
+with the recent theoretical prediction for inhomogeneously distributed electron
+and hole regions of equal mobility. At low temperatures and high magnetic
+fields rho_xx(H) saturates to a value ~h/e^2, with Hall conductivity << e^2/h,
+which may indicate a regime of localized v = 2 and v = -2 quantum Hall puddles.",0705.3239v2
+2007-07-24,Power Dependence of the Photocurrent Lineshape in a Semiconductor Quantum Dot,"We propose a kinetic theory to describe the power dependence, $I_{PC}(P)$, of
+the photocurrent (PC) lineshape in optically pumped quantum dots at low
+temperatures, in both zero and finite magnetic fields. We show that there is a
+crossover power $P_c$, determined by the electron and hole tunneling rates, at
+which the photocurrent spectra become strongly influenced by the dot kinetics,
+and no longer reflect the exciton lifetime in the dot. For $P>P_c$, we show
+that the photocurrent saturates due to the slow hole escape rate (in e.g.,
+InGaAs/GaAs dots), whereas the line-width increases with power: $\Gamma \propto
+\sqrt{P}$. We also analyze to what measure the spin-doublet lineshape of the
+photocurrent studied in a high magnetic field reflects the degree of circular
+polarization of the incident light.",0707.3555v1
+2007-08-03,Strong spin-orbit induced Gilbert damping and g-shift in iron-platinum nanoparticles,"The shape of ferromagnetic resonance spectra of highly dispersed, chemically
+disordered Fe_{0.2}Pt_{0.8} nanospheres is perfectly described by the solution
+of the Landau-Lifshitz-Gilbert (LLG) equation excluding effects by crystalline
+anisotropy and superparamagnetic fluctuations. Upon decreasing temperature, the
+LLG damping $\alpha(T)$ and a negative g-shift, g(T)-g_0, increase proportional
+to the particle magnetic moments determined from the Langevin analysis of the
+magnetization isotherms. These novel features are explained by the scattering
+of the $q \to 0$ magnon from an electron-hole (e/h) pair mediated by the
+spin-orbit coupling, while the sd-exchange can be ruled out. The large
+saturation values, $\alpha(0)=0.76$ and $g(0)/g_0-1=-0.37$, indicate the
+dominance of an overdamped 1 meV e/h-pair which seems to originate from the
+discrete levels of the itinerant electrons in the d_p=3 nm nanoparticles.",0708.0463v1
+2007-08-14,The zero-energy state in graphene in a high magnetic field,"The fate of the charge-neutral Dirac point in graphene in a high magnetic
+field $H$ has been investigated at low temperatures ($T\sim$ 0.3 K). In samples
+with small $V_0$ (the gate voltage needed to access the Dirac point), the
+resistance $R_0$ at the Dirac point diverges steeply with $H$, signalling a
+crossover to an insulating state in intense field. The approach to the
+insulating state is highly unusual. Despite the steep divergence in $R_0$, the
+profile of $R_0$ vs. $T$ in fixed $H$ saturates to a $T$-independent value
+below 2 K, consistent with charge carrying gapless excitations.",0708.1959v2
+2007-09-07,What is Minimal Model of 3He Adsorbed on Graphite? -Importance of Density Fluctuations in 4/7 Registered Solid -,"We show theoretically that the second layer of 3He adsorbed on graphite and
+solidified at 4/7 of the first-layer density is close to the fluid-solid
+boundary with substantial density fluctuations on the third layer. The solid
+shows a translational symmetry breaking as in charge-ordered insulators of
+electronic systems. We construct a minimal model beyond the multiple-exchange
+Heisenberg model. An unexpectedly large magnetic field required for the
+measured saturation of magnetization is well explained by the density
+fluctuations. The emergence of quantum spin liquid is understood from the same
+mechanism as in the Hubbard model and in \kappa-(ET)_2Cu_2(CN)_3 near the Mott
+transitions.",0709.1040v2
+2007-09-10,"Exact shering box solutions of MHD flows with resistivity, viscosity and cooling","Axisymmetric incompressible modes of the magneto-rotational instability (MRI)
+with a vertical wavenumber are exact solutions of the non-linear local
+equations of motion for a disk (shearing box). They are referred to as ""channel
+solutions"". Here, we generalize a class of these solutions to include energy
+losses, viscous, and resistive effects. In the limit of zero shear, we recover
+the result that torsional Alfv\'en waves are exact solutions of the non-linear
+equations. Our method allows the extension of these solutions into the
+dissipative regime.
+  These new solutions serve as benchmarks for simulations including dissipation
+and energy loss, and to calibrate numerical viscosity and resistivity in the
+Zeus3D code. We quantify the anisotropy of numerical dissipation and compute
+its scaling with time and space resolution. We find a strong dependence of the
+dissipation on the mean magnetic field that may affect the saturation state of
+the MRI as computed with Zeus3D. It is also shown that elongated grid cells
+generally preclude isotropic dissipation and that a Courant time step smaller
+than that which is commonly used should be taken to avoid spurious
+anti-diffusion of magnetic field.",0709.1388v1
+2007-10-19,"Disorder, Metal-Insulator crossover and Phase diagram in high-Tc cuprates","We have studied the influence of disorder induced by electron irradiation on
+the normal state resistivities $\rho(T)$ of optimally and underdoped YBa2CuOx
+single crystals, using pulsed magnetic fields up to 60T to completely restore
+the normal state. We evidence that point defect disorder induces low T upturns
+of rho(T) which saturate in some cases at low T in large applied fields as
+would be expected for a Kondo-like magnetic response. Moreover the magnitude of
+the upturns is related to the residual resistivity, that is to the
+concentration of defects and/or their nanoscale morphology. These upturns are
+found quantitatively identical to those reported in lower Tc cuprates, which
+establishes the importance of disorder in these supposedly pure compounds. We
+therefore propose a realistic phase diagram of the cuprates, including
+disorder, in which the superconducting state might reach the antiferromagnetic
+phase in the clean limit.",0710.3737v2
+2007-11-15,Enhancement in spin-torque efficiency by nonuniform spin current generated within a tapered nanopillar spin valve,"We examine the effect a spatially non-uniform spin current with a component
+polarized partially out of the plane has on a low saturation magnetization
+nanomagnet free layer. Micromagnetic simulations indicate that the spin torque
+efficiency acting upon the reversing nanomagnet can be enhanced through this
+process, resulting in faster switching with smaller currents. In doing so, we
+determine that micromagnetic structure within the nanomagnets can be beneficial
+for reversal processes. We verify this enhancement experimentally in devices
+with a tapered nanopillar geometry that generates a spin current polarized
+partly out of plane. Finally, to take even better advantage of these effects,
+we examine micromagnetically the benefits of a tapered three-magnetic-layer
+structure that further reduces reversal times while maintaining the thermal
+stability of the free layer.",0711.2479v1
+2008-03-07,Photoassociation of a Bose-Einstein Condensate near a Feshbach Resonance,"We measure the effect of a magnetic Feshbach resonance (FR) on the rate and
+light-induced frequency shift of a photoassociation resonance in ultracold
+$^7$Li. The photoassociation-induced loss rate coefficient, $K_p$, depends
+strongly on magnetic field, varying by more than a factor of 10$^4$ for fields
+near the FR. At sufficiently high laser intensities, $K_p$ for a thermal gas
+decreases with increasing intensity, while saturation is observed for the first
+time in a Bose-Einstein condensate. The frequency shift is also strongly
+field-dependent and exhibits an anomalous blue-shift for fields just below the
+FR.",0803.1167v2
+2008-04-29,Wang-Landau study of the random bond square Ising model with nearest- and next-nearest-neighbor interactions,"We report results of a Wang-Landau study of the random bond square Ising
+model with nearest- ($J_{nn}$) and next-nearest-neighbor ($J_{nnn}$)
+antiferromagnetic interactions. We consider the case $R=J_{nn}/J_{nnn}=1$ for
+which the competitive nature of interactions produces a sublattice ordering
+known as superantiferromagnetism and the pure system undergoes a second-order
+transition with a positive specific heat exponent $\alpha$. For a particular
+disorder strength we study the effects of bond randomness and we find that,
+while the critical exponents of the correlation length $\nu$, magnetization
+$\beta$, and magnetic susceptibility $\gamma$ increase when compared to the
+pure model, the ratios $\beta/\nu$ and $\gamma/\nu$ remain unchanged. Thus, the
+disordered system obeys weak universality and hyperscaling similarly to other
+two-dimensional disordered systems. However, the specific heat exhibits an
+unusually strong saturating behavior which distinguishes the present case of
+competing interactions from other two-dimensional random bond systems studied
+previously.",0804.4545v2
+2008-05-03,The Effects of Thermal Conduction on the ADAF with a Toroidal Magnetic Field,"The observation of the hot gas surrounding Sgr $A^*$ and a few other nearby
+galactic nuclei imply that electron and proton mean free paths are comparable
+to the gas capture radius. So, the hot accretion flows is likely to proceed
+under week-collision conditions. Hence, thermal conduction has been suggested
+as a possible mechanism by which the sufficient extra heating is provided in
+hot ADAF accretion disks. We consider the effects of thermal conduction in the
+presence of a toroidal magnetic field in an advection-dominated accretion flow
+around a compact object. For a steady-state structure of such accretion flows a
+set of self-similar solutions are presented. We find two types solutions which
+represent high and slow accretion rate. They have different behaviors with
+saturated thermal conduction parameter, $\phi$.",0805.0344v1
+2008-06-30,Novel Regime of Operation for Superconducting Quantum Interference Filters,"A new operating regime of the Superconducting Quantum Interference Filter
+(SQIF) is investigated. The voltage to magnetic field response function, V(H),
+is determined by a Fraunhofer dependence of the critical current and magnetic
+flux focusing effect in Josephson junctions (F-mode). For SQIF-arrays made of
+high-Tc superconducting bicrystal Josephson junctions the F-mode plays a
+predominant role in the voltage-field response V(H). The relatively large
+superconducting loops of the SQIF are used for inductive coupling to the
+external input circuit. It is shown that the output noise of a SQIF-array
+measured with a cooled amplifier in the 1-2 GHz range is determined by the
+slope of the V(H) characteristic. Power gain and saturation power were
+evaluated using low frequency SQIF parameters. Finally, we consider the
+influence of the spread in the parameters of Josephson junctions in the
+SQIF-array on the V(H) characteristic of the whole structure.",0806.4839v1
+2008-08-15,Collective excitations in two-dimensional antiferromagnet in strong magnetic field,"We discuss spin-$\frac12$ two-dimensional (2D) Heisenberg antiferromagnet
+(AF) on a square lattice at T=0 in strong magnetic field H near its saturation
+value $H_c$. A perturbation approach is proposed to obtain spectrum of magnons
+with momenta not very close to AF vector in the leading order in small
+parameter $(H_c-H)/H_c$. We find that magnons are well-defined quasi-particles
+at $H>0.9H_c$ although the damping is quite large near the zone boundary. A
+characteristic rotonlike local minimum in the spectrum is observed at ${\bf
+k}=(\pi,0)$ accompanied by decrease of the damping near $(\pi,0)$. The
+suggested approach can be used in discussion of short-wavelength excitations in
+other 2D Bose gases of particles or quasi-particles.",0808.2127v3
+2008-08-16,All Oxide Ferromagnet/Semiconductor Epitaxial Heterostructures,"Oxide based ferromagnet/semiconductor heterostructures offer substantial
+advantages for spin electronics. We have grown (111) oriented Fe3O4 thin films
+and Fe3O4/ZnO heterostructures on ZnO(0001) and Al2O3(0001) substrates by
+pulsed laser deposition. High quality crystalline films with mosaic spread as
+small as 0.03 degree, sharp interfaces, and rms surface roughness of 0.3 nm
+were achieved. Magnetization measurements show clear ferromagnetic behavior of
+the magnetite layers with a saturation magnetization of 3.2 muB/f.u. at 300 K.
+Our results demonstrate that the Fe3O4/ZnO system is an intriguing and
+promising candidate for the realization of multi-functional heterostructures.",0808.2245v1
+2008-08-21,Masses and Magnetic moments of Triply Heavy Flavour Baryons in Hypercentral Model,"Triply heavy flavour baryons are studied using the hyper central description
+of the three-body system. The confinement potential is assumed as hyper central
+coulomb plus power potential with power index $p$. The ground state
+($J^P={1/2}^+$ and ${3/2}^+$) masses of heavy flavour baryons are computed for
+different power index, $ p$ starting from 0.5 to 2.0. The predicted masses are
+found to attain a saturated value with respect to variation in $p$ beyond the
+power index $p>1.0$. Using the spin-flavour structure of the constituting
+quarks and by defining effective mass of the confined quarks within the
+baryons, the magnetic moments are computed with no additional free parameters.",0808.2880v1
+2008-09-10,Radiation-Dominated Disks Are Thermally Stable,"When the accretion rate is more than a small fraction of Eddington, the inner
+regions of accretion disks around black holes are expected to be
+radiation-dominated. However, in the alpha-model, these regions are also
+expected to be thermally unstable. In this paper, we report two 3-d radiation
+MHD simulations of a vertically-stratified shearing box in which the ratio of
+radiation to gas pressure is ~ 10, and yet no thermal runaway occurs over a
+timespan ~ 40 cooling times. Where the time-averaged dissipation rate is
+greater than the critical dissipation rate that creates hydrostatic equilibrium
+by diffusive radiation flux, the time-averaged radiation flux is held to the
+critical value, with the excess dissipated energy transported by radiative
+advection. Although the stress and total pressure are well-correlated as
+predicted by the alpha-model, we show that stress fluctuations precede pressure
+fluctuations, contrary to the usual supposition that the pressure controls the
+saturation level of the magnetic energy. This fact explains the thermal
+stability. Using a simple toy-model, we show that independently-generated
+magnetic fluctuations can drive radiation pressure fluctuations, creating a
+correlation between the two while maintaining thermal stability.",0809.1708v1
+2008-10-02,Renormalized theory of the ion cyclotron turbulence in magnetic field--aligned plasma shear flow,"The analytical treatment of nonlinear evolution of the shear-flow-modified
+current driven ion cyclotron instability and shear-flow-driven ion cyclotron
+kinetic instabilities of magnetic field--aligned plasma shear flow is
+presented. Analysis is performed on the base of the nonlinear dispersion
+equation, which accounts for a new combined effect of plasma turbulence and
+shear flow. It consists in turbulent scattering of ions across the shear flow
+with their convection by shear flow and results in enhanced nonlinear
+broadening of ion cyclotron resonances. This effect is found to lead to the
+saturation of ion cyclotron instabilities as well as to the development of
+nonlinear shear flow driven ion cyclotron instability. 52.35.Ra",0810.0362v1
+2008-10-07,Interface Ferromagnetism in (110)-Oriented La0.7Sr0.3MnO3/SrTiO3 Ultrathin Superlattices,"We explore manganite interface magnetism in epitaxially grown
+La0.7Sr0.3MnO3(LSMO)/SrTiO3 ultrathin superlattices (SL) along (110)
+orientation. we show that robust ferromagnetism persists down to four
+monolayers LSMO(MLs) (~1.1 nm in thickness), of which 50% Mn is at the
+interface state. Above eight MLs, the magnetic moment is nearly saturated to
+the theoretical value of 3.7u_B, with an estimated interface moment of 3.2u_B.
+In comparison to (100)-oriented SLs which were previously shown to have a spin
+canted ground state, (110)-oriented SLs exhibit stronger low-dimensional
+ferromagnetism and better metallicity, suggesting a ferromagnetic interface
+spin state well suited for all-oxide spintronic devices. The underlining
+mechanism is qualitatively discussed.",0810.1309v2
+2008-11-16,Evidence for Local Moment by Electron Spin Resonance Study on Polycrystalline LaFeAsO$_{1-x}$F$_x$ (x=0 and 0.13),"The temperature dependence of electron spin resonance (ESR) was studied in
+the oxypnictide superconductors LaFeAsO$_{1-x}$F$_x$ (x = 0.0 and 0.13). In the
+samples, the ESR signal indicates that the g factor and peak-to-peak linewidth
+strongly depend on temperature, especially at low temperatures. It indicates a
+strong coupling picture with existence of local moment. The dependence
+mentioned above gradually attenuates, and tends to saturation around
+room-temperature. This behavior could be ascribed to ""bottleneck"" effect due to
+coupling of local moment and itinerant electron. In addition, a Curie-Weiss
+like behavior is also observed in temperature dependent integral intensity for
+the two samples. Our results strongly support the existence of local moments in
+these materials while its origin is still unclear. The results also indicate
+strong magnetic frustration in this system, and magnetic fluctuation mechanism
+for superconductivity is suggested.",0811.2567v1
+2008-12-05,A First Look at Rotation in Inactive Late-Type M Dwarfs,"We have examined the relationship between rotation and activity in 14
+late-type (M6-M7) M dwarfs, using high resolution spectra taken at the W.M.
+Keck Observatory and flux-calibrated spectra from the Sloan Digital Sky Survey.
+Most were selected to be inactive at a spectral type where strong H-alpha
+emission is quite common. We used the cross-correlation technique to quantify
+the rotational broadening; six of the stars in our sample have vsini > 3.5
+km/s. Our most significant and perplexing result is that three of these stars
+do not exhibit H-alpha emission, despite rotating at velocities where previous
+work has observed strong levels of magnetic field and stellar activity. Our
+results suggest that rotation and activity in late-type M dwarfs may not always
+be linked, and open several additional possibilities including a
+rotationally-dependent activity threshold, or a possible dependence on stellar
+parameters of the Rossby number at which magnetic/activity ""saturation"" takes
+place in fully convective stars.",0812.1220v1
+2008-12-19,Direct Observation of Magnon Fractionalization in the Quantum Spin Ladder,"We measure by inelastic neutron scattering the spin excitation spectra as a
+function of applied magnetic field in the quantum spin-ladder material
+(C5H12N)2CuBr4. Discrete magnon modes at low fields in the quantum disordered
+phase and at high fields in the saturated phase contrast sharply with a spinon
+continuum at intermediate fields characteristic of the Luttinger-liquid phase.
+By tuning the magnetic field, we drive the fractionalization of magnons into
+spinons and, in this deconfined regime, observe both commensurate and
+incommensurate continua.",0812.3880v1
+2008-12-23,Two and One-dimensional Honeycomb Structure of Boron Nitride,"This paper presents a systematic study of two and one dimensional honeycomb
+structure of boron nitride (BN) using first-principles plane wave method.
+Two-dimensional (2D) graphene like BN is a wide band gap semiconductor with
+ionic bonding. Phonon dispersion curves demonstrate the stability of 2D BN
+flakes. Quasi 1D armchair BN nanoribbon are nonmagnetic semiconductors with
+edge states. Upon passivation of B and N with hydrogen atoms these edge states
+disappear and band gap increases. Bare zigzag BN nanoribbons are metallic, but
+become a ferromagnetic semiconductor when their both edges are passivated with
+hydrogen. However, their magnetic ground state, electronic band structure and
+band gap are found to be strongly dependent on whether B- or N-edge of the
+ribbon is saturated with hydrogen. Vacancy defects in armchair and zigzag
+nanoribbons affects also magnetic state and electronic structure. In order to
+reveal dimensionality effects these properties are contrasted with those of
+various 3D BN crystals and 1D BN atomic chain.",0812.4454v1
+2009-03-26,Simulations of the dynamic switching of vortex chirality in magnetic nanodisks by a uniform field pulse,"We present a possibility to switch the chirality of a spin vortex occurring
+in a magnetic nanodisk by applying a uniform in-plane field pulse, based on
+optimizing its strength and duration. The related spin-dynamical process,
+investigated by micromagnetic simulations, consists of several stages. After
+applying the field, the original vortex is expelled from the disk, after which
+two C-shaped states oscillate between each other. The essence of the method is
+based on turning the field off at a suitably chosen moment for which the
+orientation of the C-state will evolve into the nucleation of a vortex with the
+desirable chirality. This idea simply uses the information about the original
+chirality present inside the nanodisk during the dynamic process before losing
+it in saturation, and can thus be regarded as analogous to the recent studies
+on the polarity switching.",0903.4653v5
+2009-05-04,Magnon BEC and various phases of 3D quantum helimagnets under high magnetic field,"We study high-field phase diagram and low-energy excitations of
+three-dimensional quantum helimagnets. Slightly below the saturation field, the
+emergence of magnetic order may be viewed as Bose-Einstein condensation (BEC)
+of magnons. The method of dilute Bose gas enables a quantitative analysis of
+quantum effects in these helimagnets and thereby three phases are found: cone,
+coplanar fan and a phase-separated one. As an application, we map out the phase
+diagram of a 3D helimagnet which consists of frustrated J1-J2 chains as a
+function of frustration and an interchain coupling. Moreover, we also calculate
+the stability of the 2-magnon bound state to investigate the possibility of the
+bound-magnon BEC.",0905.0249v2
+2009-06-01,Non-Abelian Chern-Simons vortices with generic gauge groups,"We study non-Abelian Chern-Simon BPS-saturated vortices enjoying N=2
+supersymmetry in d=2+1 dimensions, with generic gauge groups of the form U(1) x
+G', with G' being a simple group, allowing for orientational modes in the
+solutions. We will keep the group as general as possible and utilizing the
+powerful moduli matrix formalism to provide the moduli spaces of vortices and
+derive the corresponding master equations. Furthermore, we study numerically
+the vortices applying a radial Ansatz to solve the obtained master equations
+and we find especially a splitting of the magnetic fields, when the coupling
+constants for the trace-part and the traceless part of the Chern-Simons term
+are varied, such that the Abelian magnetic field density can become negative
+near the origin of the vortex while the non-Abelian part stays positive, and
+vice versa.",0906.0021v1
+2009-06-08,Anomalous Pressure Dependence of the Superconducting Transition Temperature in FeSe1-x Studied by DC Magnetic Measurements,"The pressure dependence of superconducting transition temperature $T_{\rm c}$
+has been investigated through the DC magnetic measurements for FeSe$_{0.8}$ and
+FeSe$_{1.0}$. For both samples, with increasing pressure $P$, the $T_{\rm
+c}$$-$$P$ curve exhibits a two-step increase, showing a local maximum of
+$\sim$11 K at $P$$\sim$1.0 GPa and a rapid increase with an extremely large
+pressure coefficient for $P$$>$1.5 GPa. $T_{\rm c}$ saturates at $\sim$25 K (21
+K) in FeSe$_{1.0}$ (FeSe$_{0.8}$) for $P$$>$3 GPa. A rapid decrease in
+superconducting volume fraction is observed with an increase in $T_{\rm c}$
+above 1.5 GPa, suggesting the presence of electronic inhomogeneity.",0906.1534v3
+2009-08-04,Suppression of secondary phase formation in Fe implanted ZnO single crystals,"Unwanted secondary phases are one of the major problems in diluted magnetic
+semiconductor creation. Here, the authors show possibilities to avoid such
+phases in Fe implanted and postannealed ZnO(0001) single crystals. While -Fe
+nanoparticles are formed after such doping in as-polished crystals, high
+temperature (1273 K) annealing in O2 or high vacuum before implantation
+suppresses these phases. Thus, the residual saturation magnetization in the
+preannealed ZnO single crystals is about 20 times lower than for the
+as-polished ones and assigned to indirect coupling between isolated Fe ions
+rather than to clusters.",0908.0396v1
+2009-08-31,Pair Creation in Electric Flux Tube and Chiral Anomaly,"Using chiral anomaly, we discuss the pair creation of massless fermions under
+the effect of magnetic field $\vec{B}$ when an electric flux tube $\vec{E}$
+parallel to $\vec{B}$ is switched on. The tube is axial symmetric and
+infinitely long. In the limit $B\gg E$, we can analytically obtain the spatial
+and temporal behaviors of the number density of the fermions, the azimuthal
+magnetic field generated by the fermions etc.. We find that the life time $t_c$
+of the electric field is shorter as the width of the tube is narrower. Applying
+it to the glasma in high-energy heavy-ion collisions, we find that color
+electric field decays fast such as $t_c\simeq Q_s^{-1}$ with saturation
+momentum $Q_s$.",0908.4466v1
+2009-09-23,Quantum Hall effect of the surface states in topological insulator,"We study the quantum Hall effect in the surface states of topological
+insulator in the presence of a perpendicular magnetic field in the framework of
+edge states. Motion of Dirac fermions will form descrete Landau levels, among
+which a fully saturated zero mode will have different behaviors near the
+boundary according to the sign of the effective mass for Dirac fermions. The
+Hall conductance is quantized to be n (n is an integer) in the unit of e^2/h
+for a positive mass, n+1 for a negative mass, and n+1/2 for massless fermions.
+In topological insulator the massive term to the Dirac fermions can be the
+Zeeman coupling in a magnetic field or be induced by the finite-size effect in
+an ultrathin film. For example the g-factor of Bi_2Se_3 is positive and give
+rise to a positive mass term for Dirac fermions. We address experimental
+realization of the quantum Hall effect in topological insulators.",0909.4125v1
+2009-11-02,Giant anomalous Hall resistivity of the room temperature ferromagnet Fe3Sn2 - a frustrated metal with the kagome-bilayer structure,"We have investigated magnetic and transport properties of the {\it
+kagom\'{e}-bilayer} ferromagnet Fe$_{3}$Sn$_{2}$. A soft ferromagnetism and a
+large anomalous Hall effect are observed. The saturated Hall resistivity of
+Fe$_{3}$Sn$_{2}$ is 3.2 $\mu\Omega$cm at 300 K, which is almost 20 times higher
+than that of typical itinerant-ferromagnets such as Fe and Ni. The anomalous
+Hall coefficient $R_{{\rm s}}$ is 6.7$\times10^{-9}$ $\Omega$cm/G at 300 K,
+which is three orders of magnitude larger than that of pure Fe. $R_{{\rm s}}$
+obeys an unconventional scaling to the longitudinal resistivity, $\rho_{xx}$,
+of $R_{{\rm s}} \propto \rho_{xx}^{3.3}$. Such a relationship cannot be
+explained by the skew and/or side-jump mechanisms and indicates that the origin
+of the anomalous Hall effect in the frustrated magnet Fe$_{3}$Sn$_{2}$ is
+indeed extraordinary.",0911.0289v1
+2009-11-09,Electric field generation by the electron beam filamentation instability: Filament size effects,"The filamentation instability (FI) of counter-propagating beams of electrons
+is modelled with a particle-in-cell simulation in one spatial dimension and
+with a high statistical plasma representation. The simulation direction is
+orthogonal to the beam velocity vector. Both electron beams have initially
+equal densities, temperatures and moduli of their nonrelativistic mean
+velocities. The FI is electromagnetic in this case. A previous study of a small
+filament demonstrated, that the magnetic pressure gradient force (MPGF) results
+in a nonlinearly driven electrostatic field. The probably small contribution of
+the thermal pressure gradient to the force balance implied, that the
+electrostatic field performed undamped oscillations around a background
+electric field. Here we consider larger filaments, which reach a stronger
+electrostatic potential when they saturate. The electron heating is enhanced
+and electrostatic electron phase space holes form. The competition of several
+smaller filaments, which grow simultaneously with the large filament, also
+perturbs the balance between the electrostatic and magnetic fields. The
+oscillations are damped but the final electric field amplitude is still
+determined by the MPGF.",0911.1727v1
+2009-11-21,Comparison of Fluid Attenuated Inversion Recovery Sequence with Spin Echo T2-Weighted MRI for Characterization of Brain Pathology,"Twenty cases of different brain pathology have been studied via MRI using an
+open resistive magnet with magnetic field strength of 0.2 Tesla. The relative
+signal intensity with respect to the repetition time (TR) at fixed echo time
+(TE) 0.117 sec. has been studied. It was found that the signal intensity
+saturates for most lesions beyond a certain TR~6 sec in the T2 - weighted
+image. The signal intensity differs with respect to the inversion time (TI) for
+fat and cerebrospinal fluid (CSF). It was found that the intensity is nulled
+for CSF at TI ~1.5 sec. and for Fat at TI~0.10 sec in the FLAIR imaging
+sequence. Thus the intensity of the lesions is qualitatively different for the
+two sequences. From the radiological diagnostic point of view, it was concluded
+that the FLAIR sequence is more useful for the detection of lesions compared to
+T2 sequences.",0911.4159v2
+2009-12-15,Dimer mean-field model for the Ising spin glass,"A dimer mean-field model for the Ising spin-glass is presented. Despite its
+simplicity it captures some of the essential features of the spin-glass
+physics. The distribution of the single-spin magnetization is determined from a
+self-consistent integral equation. By solving the self-consistency condition
+numerically, we find that there are two temperature scales characterizing the
+glass transition. At the first, higher temperature, the glass order parameter
+becomes non-vanishing, and at the second, freezing temperature, it saturates to
+its maximal value. The effect of magnetic field and the existence of the
+Almeida-Thouless line are discussed. Finally, it is shown that the information
+compressibility, defined as the derivative of entropy with respect to energy,
+diverges at the freezing temperature. This indicates a zero internal
+temperature and true glassy dynamics with diverging relaxation times.",0912.2959v1
+2010-01-12,The magnetohydrodynamic instability of current-carrying jets,"Magnetohydrodynamic instabilities can be responsible for the formation of
+structures with various scales in astrophysical jets. We consider the stability
+properties of jets containing both the azimuthal and axial field of subthermal
+strength. A magnetic field with complex topology in jets is suggested by
+theoretical models and is consistent with recent observations. Stability is
+discussed by means of a linear analysis of the ideal magnetohydrodynamic
+equations. We argue that in azimuthal and axial magnetic fields the jet is
+always unstable to non-axisymmetric perturbations. Stabilization does not occur
+even if the strengths of these field components are comparable. If the axial
+field is weaker than the azimuthal one, instability occurs for perturbations
+with any azimuthal wave number $m$, and the growth rate reaches a saturation
+value for low values of $m$. If the axial field is stronger than the toroidal
+one, the instability shows for perturbations with relatively high $m$.",1001.1987v2
+2010-02-08,Processing and Characterization of Multiferroic Bi-relaxors,"We compare chemical solution deposition (CSD), and pulsed-laser-deposition
+(PLD), specimens of the new room-temperature, single-phase, multiferroic
+magnetoelectric, [PbFe2/3W1/3O3]x[PbZr0.53Ti0.47O3]1-x (PZTFWx ~ 0.40<x<0.20)
+with polarization, loss (<1%), and resistivity (typically 108 ohm.cm) equal to
+or superior to BiFeO3. Single phase polycrystalline multiferroics PZTFWx thin
+films were fabricated on platinized silicon substrate by CSD and as epitaxial
+single-crystal films on MgO substrate by PLD. High dielectric constants (1200-
+3000), high polarization (30 - 60 micro C/cm2), weak saturation magnetization
+(0.48 - 4.53 emu/cm3), a broad dielectric temperature peak, high-frequency
+dispersion, low dielectric loss and low leakage current were observed in these
+materials, suggesting the family as candidates for room-temperature
+multiferroic devices. The ferroelectric switching in these materials can be
+suppressed or quenched with applied magnetic field.",1002.1637v1
+2010-02-12,Instability of Magnons in Two-dimensional Antiferromagnet at High Magnetic Fields,"Spin dynamics of the square lattice Heisenberg antiferromagnet, \BaMnGeO, is
+studied by a combination of bulk measurements, neutron diffraction, and
+inelastic neutron scattering techniques. Easy plane type antiferromagnetic
+order is identified at $T \le 4.0$ K. The exchange interactions are estimated
+as $J_1$ = 27.8(3)${\mu}$eV and $J_2$ = 1.0(1) ${\mu}$eV, and the saturation
+field $H_{\rm C}$ is 9.75 T. Magnetic excitation measurements with high
+experimental resolution setup by triple axis neutron spectrometer reveals the
+instability of one magnon excitation in the field range of $0.7H_{\rm C}
+\lesssim H \lesssim 0.85H_{\rm C}$.",1002.2470v1
+2010-02-19,Resistive double-diffusive instability in the dead-zones of protostellar disks,"We outline a novel linear instability that may arise in the dead-zones of
+protostellar disks, and possibly the fluid interiors of planets and
+protoplanets. In essence it is an axisymmetric buoyancy instability, but one
+that would not be present in a purely hydrodynamical gas. The necessary
+ingredients for growth include a negative radial entropy gradient (of any
+magnitude), weak magnetic fields, and efficient resistive diffusion (in
+comparison with thermal diffusion). The character of the instability is local,
+axisymmetric, and double-diffusive, and it attacks lengths much shorter than
+the resistive scale. Like the axisymmetric convective instability, it draws its
+energy from the negative radial entropy gradient; but by utilising the
+diffusing magnetic field, it can negate the stabilising influence of rotation.
+Its nonlinear saturated state, while not transporting appreciable angular
+momentum, could drive radial and vertical mixing, which may influence the
+temperature structure of the disk, dust dynamics and, potentially, planet
+formation.",1002.3750v2
+2010-08-03,Transverse Thermoelectric Conductivity of Bilayer Graphene in Quantum Hall Regime,"We performed electric and thermoelectric transport measurements of bilayer
+graphene in a magnetic field up to 15 Tesla. The transverse thermoelectric
+conductivity $\rm\alpha_{xy}$, determined from four transport coefficients,
+attains a peak value of $\rm\alpha_{xy, peak}$ whenever chemical potential lies
+in the center of a Landau level. The temperature dependence of $\rm\alpha_{xy,
+peak}$ is dictated by the disorder width $\rm W_L$. For $\rm k_BT/W_L\leq$0.2,
+$\rm\alpha_{xy, peak}$ is nominally linear in temperature, which gives
+$\rm\alpha_{xy,peak}/T=0.19 \pm 0.03 n A/K^2$ independent of the magnetic
+field, temperature and Landau Level index. At $\rm k_BT/W_L\geq$0.5,
+$\rm\alpha_{xy, peak}$ saturates to a value close to the predicted universal
+value of $\rm 4\times(ln2)k_Be/h$ according to the theory of Girvin and Jonson.
+We remark that an anomaly is found in $\rm\alpha_{xy}$ near the charge neutral
+point, similar to that in single-layer graphene",1008.0442v2
+2010-09-13,Theromelectricity in Graphene: Effects of a gap and magnetic fields,"We calculate the thermopower of monolayer graphene in various circumstances.
+First we show that experiments on the thermopower of graphene can be understood
+quantitatively with a very simple model of screening in the semiclassical
+limit. We can calculate the energy dependent scattering time for this model
+exactly. We then consider acoustic phonon scattering which might be the
+operative scattering mechanism in free standing films, and predict that the
+thermopower will be linear in any induced gap in the system. Further, the
+thermopower peaks at the same value of chemical potential (tunable by gate
+voltage) independent of the gap. Finally, we show that in the semiclassical
+approximation, the thermopower in a magnetic field saturates at high field to a
+value which can be calculated exactly and is independent of the details of the
+scattering. This effect might be observable experimentally.",1009.2343v1
+2010-10-09,Temperature dependence of Magnetic properties in Nanocrystalline copper ferrite thin films,"The copper ferrite thin films have been deposited by RF sputtering at a 50W
+rf power. The As-deposited films are annealed in air at $800^{\circ}$C and then
+slow cooled. The As-deposited (AD) as well as slow cooled (SC) films are
+studied using a SQUID Magnetometer. The M Vs H curves have been recorded at
+various temperatures between 5K to 300K. The coercivities obtained from the MH
+curves are then plotted against temperature (T). The magnetization in the films
+does not saturate, even at the highest field of 7T. The high field part of the
+M Vs H curves is fitted using the H1/2 term of Chikazumi expression M(H)= Q*(1-
+a /Hn), with n=1/2. The variation of coefficient 'a' of H1/2 term has been
+observed with temperature (T). An attempt has been made to correlate this with
+the coercivity (Hc) in the case of annealed films.",1010.1882v1
+2010-10-15,Post-flare evolution of AR 10923 with Hinode/XRT,"Flares are dynamic events which involve rapid changes in coronal magnetic
+topology end energy release. Even if they may be localized phenomena, the
+magnetic disturbance at their origin may propagate and be effective in a larger
+part of the active region. We investigate the temporal evolution of a flaring
+active region with respect to the loops morphology, the temperature, and
+emission measure distributions. We consider $Hinode/XRT$ data of a the 2006
+November 12th C1.1 flare. We inspect the evolution of the morphology of the
+flaring region also with the aid of TRACE data. XRT filter ratios are used to
+derive temperature and emission measure maps and evolution. The analyzed flare
+includes several brightenings. We identify a coherent sequence of tangled and
+relaxed loop structures before, during, and after the brightenings. Although
+the thermal information is incomplete because of pixel saturation at the flare
+peak, thermal maps show fine, evolving spatial structuring. Temperature and
+emission measure variations show up in great detail, and we are able to detect
+a secondary heating of larger loops close to the proper flaring region. Finally
+we estimate the amount of energy released in these flaring loops during the
+flare decay.",1010.3124v1
+2010-10-29,Field-Induced Gap in a Quantum Spin-1/2 Chain in a Strong Magnetic Field,"Magnetic excitations in copper pyrimidine dinitrate, a spin-1/2
+antiferromagnetic chain with alternating $g$-tensor and Dzyaloshinskii-Moriya
+interactions that exhibits a field-induced spin gap, are probed by means of
+pulsed-field electron spin resonance spectroscopy. In particular, we report on
+a minimum of the gap in the vicinity of the saturation field $H_{sat}=48.5$ T
+associated with a transition from the sine-Gordon region (with soliton-breather
+elementary excitations) to a spin-polarized state (with magnon excitations).
+This interpretation is fully confirmed by the quantitative agreement over the
+entire field range of the experimental data with the DMRG investigation of the
+spin-1/2 Heisenberg chain with a staggered transverse field.",1010.6141v1
+2010-12-20,Particle size dependence of magnetization and non-centrosymmetry in nanoscale BiFeO3,"The saturation magnetization (M_s), antiferromagnetic transition point (T_N),
+and the off-center displacements of Bi and Fe ions have been measured as a
+function of particle size in nanoscale BiFeO3. T_N decreases down to ~550 K for
+particles of size ~5 nm from ~653 K in bulk while M_s rises by more than an
+order of magnitude. Analysis of crystallographic structure from Rietveld
+refinement of x-ray diffraction patterns shows significant rise in off-center
+displacements of Bi (del_Bi) and Fe (del_Fe) ions within a unit cell with the
+decrease in particle size. The net unit-cell polarization P_S too, is found to
+be larger in nanoscale regime.",1012.4288v1
+2011-01-14,Investigation of phonon behavior in Pr2NiMnO6 by micro-Raman spectroscopy,"The temperature dependence of phonon excitations and the presence of spin
+phonon coupling in polycrystalline Pr2NiMnO6 samples were studied using
+micro-Raman spectroscopy and magnetometry. Magnetic properties show a single
+ferromagnetic-to-paramagnetic transition at 228 K and a saturation
+magnetization close to 4.95 \muB/f.u.. Three distinct Raman modes at 657, 642,
+and 511 cm-1 are observed. The phonon excitations show a clear hardening due to
+anharmonicity from 300 K down to 10 K. Further, temperature dependence of the
+657 cm-1 mode shows only a small softening. This reflects the presence of a
+relatively weak spin-phonon coupling in Pr2NiMnO6 contrary to other double
+perovskites previously studied.",1101.2805v1
+2011-01-27,Asymmetric graphene model applied to graphite-like carbon-based ferromagnetism,"Several experiments have recently found room-temperature ferromagnetism in
+graphite-like carbon based materials. This paper offers a model explaining such
+ferromagnetism by using an asymmetric nano-graphene. Our first typical model is
+C48H24 graphene molecule, which has three dihydrogenated (-CH2) zigzag edges.
+There are several multiple spin states competing for stable minimum energy in
+the same atomic topology. Both molecular orbital and density function theory
+methods indicate that the quartet state(S=3/2) is more stable than that of
+doublet (S=1/2), which means that larger saturation magnetization will be
+achieved. We also enhanced this molecule to an infinite length ribbon having
+many (-CH2) edges. Similar results were obtained where the highest spin state
+was more stable than lower spin state. In contrast, a nitrogen substituted
+(-NH) molecule C45N3H21 demonstrated opposite results. that is, the lowest spin
+state(S=1/2) is more stable than that of highest one(S=3/2), which arises from
+the slight change in atom position.",1101.5209v1
+2011-02-19,Manganese valence and magnetotransport in ultrathin films of La$_{0.67}$Ca$_{0.33}$MnO$_3$,"We report a comparative study of the properties of very thin films of
+La$_{0.67}$Ca$_{0.33}$MnO$_3$ grown epitaxially under strain on flat SrTiO$_3$
+(STO), lattice matched on NdGaO$_3$ (NGO), and strained on $1^{\circ}$-miscut
+STO. We use transmission electron microscopy and electron energy loss
+spectroscopy to study the microstructure, composition, and Mn valence state.
+Near the interface we find no significant segregation, but a charge
+compensation layer where the valence is enhanced over the nominal value of
+3.3+, and a relaxation to this value over several nanometer. The transport
+properties show well-known behavior for the films on flat STO and NGO, namely
+values of the metal-insulator transition temperature which are strongly (STO)
+or only little (NGO) reduced with respect to the bulk value. The reduction in
+films on miscut STO however is less strong than in films on flat STO, even
+though they appear similar as to strain state and interface layer.
+Magnetically, we find reduced values of the saturation magnetization for the
+strained films with respect to the bulk value, which cannot only be ascribed to
+the interface layer.",1102.4004v1
+2011-05-05,Antiferromagnet with two coupled antiferromagnetic sublattices in a magnetic field,"We discuss the magnon spectrum of an antiferromagnet (AF) in a magnetic field
+$h$ consisting of two interpenetrating AF sublattices coupled by the exchange
+interaction at T=0. One-ion easy-plane anisotropy is also taken into account.
+We calculate using the 1/S expansion the gap in the spectrum which is a
+manifestation of the order-by-disorder effect in this system and the optical
+magnon mode splitting. Both of these phenomena originate from the
+inter-sublattice interaction. We calculate also the gap value at $h\approx h_c$
+in the leading order of the small parameter $(h_c-h)/h_c$ using the magnon
+Bose-Einstein condensation treatment, where $h_c$ is the saturation field. By
+comparing results obtained within these two approaches we conclude that the 1/S
+expansion gives a qualitatively correct result at $h\sim h_c$ even at large
+one-ion anisotropy but it overestimates the gap value. The application is
+discussed of these results to the actively studied AF of the considered type
+$\rm NiCl_2$-$\rm 4SC(NH_2)_2$ (DTN).",1105.1044v1
+2011-05-26,Schwinger Mechanism with Energy Dissipation in Glasma,"Initial states of glasma in high energy heavy ion collisions are longitudinal
+classical color electric and magnetic fields. Assuming finite color electric
+conductivity, we show that the color electric field decays by quark pair
+production with the life time of the order of $Q_s^{-1}$, i.e. the inverse of
+the saturation momentum. Quarks and anti-quarks created in the pair production
+are immediately thermalized as far as their temperature $\beta^{-1}$ is lower
+than $Q_s$. Namely, a relaxation time of the quarks to be thermalized is much
+shorter than $Q_s^{-1}$ when $\beta^{-1} \ll Q_s$. We also show that the quarks
+acquire longitudinal momentum of the order of $Q_s$ by the acceleration of the
+electric field. To discuss the quark pair production, we use chiral anomaly
+which has been shown to be very powerful tool in the presence of strong
+magnetic field.",1105.5188v2
+2011-06-07,Magnetoelastic effects in Jahn-Teller distorted CrF$_2$ and CuF$_2$ studied by neutron powder diffraction,"We have studied the temperature dependence of crystal and magnetic structures
+of the Jahn-Teller distorted transition metal difluorides CrF$_2$ and CuF$_2$
+by neutron powder diffraction in the temperature range 2-280 K. The lattice
+parameters and the unit cell volume show magnetoelastic effects below the
+N\'eel temperature. The lattice strain due to the magnetostriction effect
+couples with the square of the order parameter of the antiferromagnetic phase
+transition. We also investigated the temperature dependence of the Jahn-Teller
+distortion which does not show any significant effect at the antiferromagnetic
+phase transition but increases linearly with increasing temperature for CrF$_2$
+and remains almost independent of temperature in CuF$_2$. The magnitude of
+magnetovolume effect seems to increase with the low temperature saturated
+magnetic moment of the transition metal ions but the correlation is not at all
+perfect.",1106.1349v1
+2011-07-21,The Kelvin-Helmholtz instability in weakly ionised plasmas: Ambipolar dominated and Hall dominated flows,"The Kelvin-Helmholtz instability is well known to be capable of converting
+well-ordered flows into more disordered, even turbulent, flows. As such it
+could represent a path by which the energy in, for example, bowshocks from
+stellar jets could be converted into turbulent energy thereby driving molecular
+cloud turbulence. We present the results of a suite of fully multifluid
+magnetohydrodynamic simulations of this instability using the HYDRA code. We
+investigate the behaviour of the instability in a Hall dominated and an
+ambipolar diffusion dominated plasma as might be expected in certain regions of
+accretion disks and molecular clouds respectively.
+  We find that, while the linear growth rates of the instability are unaffected
+by multifluid effects, the non-linear behaviour is remarkably different with
+ambipolar diffusion removing large quantities of magnetic energy while the Hall
+effect, if strong enough, introduces a dynamo effect which leads to continuing
+strong growth of the magnetic field well into the non-linear regime and a lack
+of true saturation of the instability.",1107.4241v1
+2011-07-21,Approaching Quantum Criticality in ferromagnetic Ce_2 (Pd_1-x Rh_x)_2 In alloys,"Low temperature magnetic and thermal (C_m) properties of the ferromagnetic
+(FM) alloys Ce_2.15 (Pd_1-x Rh_x)_1.95 In_0.9 were investigated in order to
+explore the possibility for tuning a quantum critical point (QCP) by doping Pd
+with Rh. As expected, the magnetic transition observed at T = 4.1K in the
+parent alloy decreases with increasing Rh concentration. Nevertheless it splits
+into two transitions, the upper being antiferromagnetic (AF) whereas the lower
+FM. The AF phase boundary extrapolates to T_N = 0 for x_cr ~ 0.65 whereas the
+first order FM transition vanishes at x ~ 0.3. The QC character of the T_N => 0
+point arises from the divergent T dependence of the tail of C_m/T observed in
+the x = 0.5 and 0.55 alloys, and the tendency to saturation of the maximum of
+C_m(T_N)/T as observed in exemplary Ce compounds for T_N => 0. Beyond the
+critical concentration the unit cell volume deviates from the Vegard's law in
+coincidence with a strong increase of the Kondo temperature.",1107.4308v1
+2011-09-09,"Magnetisation Studies of Geometrically Frustrated Antiferromagnets SrLn2O4, with Ln = Er, Dy and Ho","We present the results of susceptibility \chi(T) and magnetisation M(H)
+measurements performed on single crystal samples of the rare-earth oxides
+SrLn2O4 (Ln = Er, Dy and Ho). The measurements reveal the presence of magnetic
+ordering transition in SrHo2O4 at 0.62 K and confirm that SrEr2O4 orders
+magnetically at 0.73 K, while in SrDy2O4 such a transition is absent down to at
+least 0.5 K. The observed ordering temperatures are significantly lower than
+the Curie-Weiss temperatures, \theta_{CW}, obtained from the high-temperature
+linear fits to the 1/\chi(T) curves, which implies that these materials are
+subject to geometric frustration. Strong anisotropy found in the \chi(T) curves
+for a field applied along the different crystallographic directions is also
+evident in the M(H) curves measured both above and below the ordering
+temperatures. For all three compounds the magnetisation plateaux at
+approximately one third of the magnetisation saturation values can be seen for
+certain directions of applied field, which is indicative of field-induced
+stabilisation of a collinear {\it two-up one-down} structure.",1109.2094v1
+2011-09-27,Field-dependent anisotropic magnetoresistance and planar Hall effect in epitaxial magnetite thin films,"A systematic study of the temperature and magnetic field dependence of the
+longitudinal and transverse resistivities of epitaxial thin films of magnetite
+(Fe3O4) is reported. The anisotropic magnetoresistance (AMR) and the planar
+Hall effect (PHE) are sensitive to the in-plane orientation of current and
+magnetization with respect to crystal axes in a way consistent with the cubic
+symmetry of the system. We also show that the AMR exhibit sign reversal as a
+function of temperature, and that it shows significant field dependence without
+saturation up to 9 T. Our results provide a unified description of the
+anisotropic magnetoresistance effects in epitaxial magnetite films and
+illustrate the need for a full determination of the resistivity tensor in
+crystalline systems.",1109.5828v1
+2011-10-24,CoB/Ni-Based Multilayer Nanowire with High-Speed Domain Wall Motion under Low Current Control,"The spin-transfer torque motion of magnetic domain walls (DWs) in a
+CoB/Ni-based nanowire driven by a low current density of
+(1.12\pm0.8)\times10^{11} A m^{-2} has been observed indirectly by
+magnetotransport measurements. A high DW velocity of 85\pm4 m/s at zero field
+was measured at the threshold current density. Upon increasing the current
+density to 2.6\times10^{11} A m^{-2}, the DW velocity increases to 197\pm16 m/s
+before decreasing quickly in the high-current-density regime attributed to
+nonadiabatic spin-transfer torque at a low damping factor and weak pinning. The
+addition of B atoms to the Co layers decreased the magnitude of saturation
+magnetization, Gilbert damping factor, and density of pinning sites, making the
+CoB/Ni multilayer nanowire favorable for practical applications.",1110.5112v3
+2011-11-28,Investigation of weak itinerant ferromagnetism and critical behavior of Y$_2$Ni$_7$,"The weak itinerant ferromagnetic behavior of Y$_2$Ni$_7$ is investigated
+through magnetic, transport and calorimetric measurements. The low value of
+saturation moment, large Rhodes-Wohlfarth ratio, large value of the linear term
+in heat capacity and Fermi liquid like resistivity behavior with enhanced
+electron-electron scattering contribution establish firmly the weak itinerant
+ferromagetic nature of the sample. The critical exponents associated with the
+paramagnetic to ferromagnetic transition are also investigated from
+magnetization isotherms using modified Arrott plot, Kouvel-Fisher plot and
+critical isotherm technique. The more accurate Kouvel-Fisher plot provides the
+critical exponents to be $\beta$ = 0.306, $\gamma$ = 1.401 and $\delta$ =
+5.578. These values are markedly different from the mean field values and
+correspond closely to the two dimensional Ising spin system with long range
+spin spin interaction.",1111.6343v1
+2012-01-27,Deconfinement in the presence of a strong magnetic background: an exercise within the MIT bag model,"We study the effect of a very strong homogeneous magnetic field B on the
+thermal deconfinement transition within the simplest phenomenological approach:
+the MIT bag pressure for the quark- gluon plasma and a gas of pions for the
+hadronic sector. Even though the model is known to be crude in numerical
+precision and misses the correct nature of the (crossover) transition, it
+provides a simple setup for the discussion of some subtleties of vacuum and
+thermal contributions in each phase, and should provide a reasonable
+qualitative description of the critical temperature in the presence of B. We
+find that the critical temperature decreases, saturating for very large fields.",1201.5881v3
+2012-03-01,Edge superconducting state in Nb thin film with rectangular arrays of antidots,"Superconducting Nb thin films with rectangular arrays of submicron antidots
+have been systemically investigated by transport measurements. In low fields,
+the magnetoresistance curves demonstrate well-defined dips at integral and
+rational numbers of flux quanta per unit cell, which corresponds to a
+superconducting wire network-like regime. When the magnetic field is higher
+than a saturation field, interstitial vortices interrupt the collective
+oscillation in low fields and form vortex sublattice, where a larger magnetic
+field interval is observed. In higher fields, a crossover behavior from the
+interstitial sublattice state to a single-loop-like state is observed,
+characterized by oscillations with a period of $\Phi_0/\pi r_{eff}^2$,
+originating from the existence of edge superconducting states with a size
+$r_{eff}$ around the antidots.",1203.0269v2
+2012-05-15,GaMnN epitaxial films with high magnetization,"We report on the fabrication of pseudomorphic wurtzite GaMnN grown on GaN
+with Mn concentrations up to 10% using molecular beam epitaxy. According to
+Rutherford backscattering the Mn ions are mainly at the Ga-substitutional
+positions, and they are homogeneously distributed according to depth-resolved
+Auger-electron spectroscopy and secondary-ion mass-spectroscopy measurements. A
+random Mn distribution is indicated by transmission electron microscopy, no
+Mn-rich clusters are present for optimized growth conditions. A linear increase
+of the c-lattice parameter with increasing Mn concentration is found using
+x-ray diffraction. The ferromagnetic behavior is confirmed by superconducting
+quantum-interference measurements showing saturation magnetizations of up to
+150 emu/cm^3.",1205.3475v2
+2012-05-30,Planetesimal Formation in Magnetorotationally Dead Zones: Critical Dependence on the Net Vertical Magnetic Flux,"Turbulence driven by magnetorotational instability (MRI) affects planetesimal
+formation by inducing diffusion and collisional fragmentation of dust
+particles. We examine conditions preferred for planetesimal formation in
+MRI-inactive ""dead zones"" using an analytic dead-zone model based on our recent
+resistive MHD simulations. We argue that successful planetesimal formation
+requires not only a sufficiently large dead zone (which can be produced by tiny
+dust grains) but also a sufficiently small net vertical magnetic flux (NVF).
+Although often ignored, the latter condition is indeed important since the NVF
+strength determines the saturation level of turbulence in MRI-active layers. We
+show that direct collisional formation of icy planetesimal across the
+fragmentation barrier is possible when the NVF strength is lower than 10 mG
+(for the minimum-mass solar nebula model). Formation of rocky planetesimals via
+the secular gravitational instability is also possible within a similar range
+of the NVF strength. Our results indicate that the fate of planet formation
+largely depends on how the NVF is radially transported in the initial disk
+formation and subsequent disk accretion processes.",1205.6754v1
+2012-06-04,The role of stepped surfaces on the magnetotransport in strained thin films of La0.67Ca0.33MnO3,"We report a comparative study of the properties of very thin films of
+La0.67Ca0.33MnO3 grown epitaxially under strain on flat SrTiO3 (STO) and on 1
+deg miscut STO. For the films on flat STO the transport properties show
+well-known behavior, namely values of the metal-insulator transition
+temperature which are strongly reduced with respect to the bulk value. The
+reduction in films on miscut STO is significantly less strong than in films on
+flat STO, even though they appear similar as to strain state. Moreover, the
+residual resistance at low temperatures is lower than for the case of flat
+films. Magnetically, we find reduced values of the saturation magnetization
+with respect to the bulk value, indicating the presence of a dead layer in both
+cases. We argue that the higher density of the step edges on the miscut
+substrates lead to strain relaxation in the form of point defects and an
+increased electronic bandwidth, which actually make the electronic properties
+more robust.",1206.0767v1
+2012-06-19,Magnetic vortex-antivortex crystals generated by spin-polarized current,"We study vortex pattern formation in thin ferromagnetic films under the
+action of strong spin-polarized currents. Considering the currents which are
+polarized along the normal of the film plane, we determine the critical current
+above which the film goes to a saturated state with all magnetic moments being
+perpendicular to the film plane. We show that stable square vortex-antivortex
+superlattices (\emph{vortex crystals}) appears slightly below the critical
+current. The melting of the vortex crystal occurs with current further
+decreasing. A mechanism of current-induced periodic vortex-antivortex lattice
+formation is proposed. Micromagnetic simulations confirm our analytical results
+with a high accuracy.",1206.4125v2
+2012-07-17,Friedel oscillations and horizon charge in 1D holographic liquids,"In many-body fermionic systems at finite density correlation functions of the
+density operator exhibit Friedel oscillations at a wavevector that is twice the
+Fermi momentum. We demonstrate the existence of such Friedel oscillations in a
+3d gravity dual to a compressible finite-density state in a (1+1) dimensional
+field theory. The bulk dynamics is provided by a Maxwell U(1) gauge theory and
+all the charge is behind a bulk horizon. The bulk gauge theory is compact and
+so there exist magnetic monopole tunneling events. We compute the effect of
+these monopoles on holographic density-density correlation functions and
+demonstrate that they cause Friedel oscillations at a wavevector that directly
+counts the charge behind the bulk horizon. If the magnetic monopoles are taken
+to saturate the bulk Dirac quantization condition then the observed Fermi
+momentum exactly agrees with that predicted by Luttinger's theorem, suggesting
+some Fermi surface structure associated with the charged horizon. The mechanism
+is generic and will apply to any charged horizon in three dimensions. Along the
+way we clarify some aspects of the holographic interpretation of Maxwell
+electromagnetism in three bulk dimensions and show that perturbations about the
+charged BTZ black hole exhibit a hydrodynamic sound mode at low temperature.",1207.4208v1
+2012-08-10,"Electronic structure, optical and magnetic properties of Co$_{2}$FeGe Heusler alloy films","Optical properties of ferromagnetic half-metallic full-Heusler Co$_{2}$FeGe
+alloy are investigated experimentally and theoretically. Co$_{2}$FeGe thin
+films were obtained by DC magnetron sputtering and show the saturation
+magnetization at $T$=10 K of $m\approx$5.6 $\mu_{B}$/f.u., close to the value
+predicted by the Slater-Pauling rule. First-principles calculations of the
+electronic structure and the dielectric tensor are performed using the
+full-potential linearized-augmented-plane-wave method in the generalized
+gradient (GGA) and GGA+U approximations. The measured interband optical
+conductivity spectrum for the alloy exhibits a strong absorption band in the 1
+- 4 eV energy range with pronounced fine structure, which agrees well with the
+calculated half-metallic spectrum of the system, suggesting a near perfect
+spin-polarization in the material.",1208.2193v1
+2012-08-31,Ordering in weakly coupled random singlet spin chains,"The influence of bond randomness on long range magnetic ordering in the
+weakly coupled S = 1/2 antiferromagnetic spin chain materials
+Cu(py)2(Cl1-xBrx)2 is studied by muon spin rotation and bulk measurements.
+Disorder is found to have a strong effect on the ordering temperature TN, and
+an even stronger one on the saturation magnetization m0, but considerably more
+so in the effectively lower-dimensional Br-rich materials. The observed
+behavior is attributed to Random Singlet ground states of individual spin
+chains, but remains in contradiction with chain mean field theory predictions.
+In this context, we discuss the possibility of a universal distribution of
+ordered moments in the weakly coupled Random Singlet chains model.",1208.6479v2
+2012-09-27,"Insulating behavior at the neutrality point in dual-gated, single-layer graphene","The fate of the low-temperature conductance at the charge-neutrality (Dirac)
+point in a single sheet of graphene is investigated down to 20 mK. As the
+temperature is lowered, the peak resistivity diverges with a power-law behavior
+and becomes as high as several Megohms per square at the lowest temperature, in
+contrast with the commonly observed saturation of the conductivity. As a
+perpendicular magnetic field is applied, our device remains insulating and
+directly transitions to the broken-valley-symmetry, nu=0 quantum Hall state,
+indicating that the insulating behavior we observe at zero magnetic field is a
+result of broken valley symmetry. Finally we discuss the possible origins of
+this effect.",1209.6364v2
+2012-10-12,Shearing box simulations of accretion disk winds,"The launching process of a magnetically driven outflow from an accretion disk
+is investigated in a local, shearing box model which allows a study of the
+feedback between accretion and angular momentum loss. The mass-flux instability
+found in previous linear analyses of this problem is recovered in a series of
+2D (axisymmetric) simulations in the MRI-stable (high magnetic field strength)
+regime. At low field strengths that are still sufficient to suppress MRI, the
+instability develops on a short radial length scale and saturates at a modest
+amplitude. At high field strengths, a long-wavelength ""clump"" instability of
+large amplitude is observed, with growth times of a few orbits. As speculated
+before, the unstable connection between disk and outflow may be relevant for
+the time dependence observed in jet-producing disks. The success of the
+simulations is due in a large part to the implementation of an effective
+wave-transmitting upper boundary condition.",1210.3574v1
+2012-10-26,Spin injection from a half-metal at finite temperatures,"Spin injection from a half-metallic electrode in the presence of thermal spin
+disorder is analyzed using a combination of random matrix theory,
+spin-diffusion theory, and explicit simulations for the tight-binding s-d
+model. It is shown that efficient spin injection from a half-metal is possible
+as long as the effective resistance of the normal metal does not exceed a
+characteristic value, which does not depend on the resistance of the
+half-metallic electrode, but is rather controlled by spin-flip scattering at
+the interface. This condition can be formulated as \alpha<(l/L)/T, where \alpha
+is the relative deviation of the magnetization from saturation, l and L the
+mean-free path and the spin-diffusion length in the non-magnetic channel, and T
+the transparency of the tunnel barrier at the interface (if present). The
+general conclusions are confirmed by tight-binding s-d model calculations. A
+rough estimate suggests that efficient spin injection from true half-metallic
+ferromagnets into silicon or copper may be possible at room temperature across
+a transparent interface.",1210.7194v2
+2012-12-23,Classical Model Predictive Control of a Permanent Magnet Synchronous Motor,"A model predictive control (MPC) scheme for a permanent-magnet synchronous
+motor (PMSM) is presented. The torque controller optimizes a quadratic cost
+consisting of control error and machine losses repeatedly, accounting the
+voltage and current limitations. The scheme extensively relies on optimization,
+to meet the runtime limitation, a suboptimal algorithm based on differential
+flatness, continuous parameterization and linear programming is introduced.
+  The multivariable controller exploits cross-coupling effects in the
+long-range constrained predictive control strategy. The optimization results in
+fast and smooth torque dynamics while inherently using field-weakening to
+improve the power efficiency and the current dynamics in high speed operation.
+As distinctive MPC feature, constraint handling is improved, instead of just
+saturating the control input, field weakening is applied dynamically to bypass
+the voltage limitation. The performance of the scheme is demonstrated by
+experimental and numerical results.",1212.5815v2
+2013-01-25,Upper critical field of isoelectron substituted SrFe$_2$(As$_{1-x}$P$_x$)$_2$,"The upper critical field $H_{c2}$ of optimally doped iron-based
+superconductor SrFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ ($x$ = 0.35, $T_c$ = 25 K)
+was measured as a function of temperature down to 1.6 K for two principal
+directions of magnetic field $H \parallel c$ and $H \parallel a$. Measurements
+were performed in pulsed magnetic fields up to 65 T using a tunnel-diode
+resonator technique on as-grown and heavy-ion irradiated single crystals, with
+columnar defect density corresponding to a matching field $B\phi$ = 25 T. The
+$H_{c2,c}(T)$ is close to $T$-linear, while clear saturation is observed for
+$H_{c2,a}(T)$, leading to a strongly temperature dependent anisotropy parameter
+$\gamma$. The linear shape of $H_{c2,c}(T)$ is very similar to that observed in
+nodal KFe$_2$As$_2$ but very different from full-gap LiFeAs. Irradiation does
+not introduce any additional features on $H_{c2}(T)$ line corresponding to the
+matching field. Instead, it suppresses uniformly both $T_c$ and $H_{c2}$,
+keeping their ratio constant.",1301.6142v1
+2013-02-24,Superparamagnetic Transition and Local Disorder in CuFe2O4 Nanoparticles,"We present X-ray diffraction (XRD), M\""ossbauer spectroscopy (MS) and d.c.
+magnetization measurements performed on ball-milled CuFe2O4 samples. The
+average particle size <d> was found to decrease to the nanometer range after
+t=15 min of milling. Room temperature M\""ossbauer data showed that the fraction
+of particles above the blocking temperature TB increases with milling time, and
+almost complete superparamagnetic samples are obtained for <d> = 7(2) nm.
+Magnetization measurements below TB suggest spin canting in milled samples. The
+values of saturation moment mu_S reveal that site populations are slightly
+affected by milling. M\""ossbauer resonant intensities are accounted for on the
+basis of local disorder of Fe3+ environments, and the development of sample
+inhomogeneities of CuxFe3-xO4 composition.",1302.5876v1
+2013-04-07,Critical Temperature Studies of the Anisotropic Bi- and Multilayer Heisenberg Ferromagnets in Pair Approximation,"The Pair Approximation method is applied to studies of the bilayer and
+multilayer magnetic systems with simple cubic structure. The method allows to
+take into account quantum effects related with non-Ising couplings. The paper
+adopts the anisotropic Heisenberg model for spin $S=1/2$ and considers the
+phase transition temperatures as a function of the exchange integrals strength
+in line with the role of intra- and interplanar anisotropic interactions in the
+onset of low-dimensional magnetism. The compensation effect for the Curie
+temperature is found for asymmetric interactions within the neighbouring planes
+of the bilayer system. The paper predicts the saturation of the Curie
+temperature for strong interplanar interactions. However, such an effect for
+the multilayer system occurs only when the interplanar interactions are of
+purely isotropic character.",1304.2029v1
+2013-05-15,Roles of oxygen vacancies on ferromagnetism in Ni doped In2O3: A hybrid functional study,"The roles of oxygen vacancies on the electronic and magnetic properties of Ni
+doped In$_2$O$_3$ have been studied by first-principles calculations based on
+hybrid functional theory. Our results predict that the Ni-doped In$_2$O$_3$
+system displays a ferromagnetic semiconducting character. However, the presence
+of oxygen vacancies results in antiferromagnetic coupling between the
+neighboring Ni pair bridged by an oxygen vacancy. The antiferromagnetic
+coupling is found to arise from the predominant role of superexchange due to
+the strong Ni 3d-O 2p hybridization. Consequently, the oxygen vacancies play a
+key role in the lower saturation magnetization of Ni:In$_2$O$_3$
+polycrystalline sample, as observed in experiments.",1305.3391v2
+2013-06-29,Strain-induced enhancement of coercivity in amorphous TbFeCo films,"We report a strong size dependence of coercivity in amorphous ferrimagnetic
+TbFeCo films. The as-deposited film exhibited a low saturation magnetization
+(Ms=100 emu/cc) and a high perpendicular anisotropy (Ku=10^6 erg/cc). Hall-bar
+devices were fabricated for characterizing the magneto-transport behaviors. A
+significant increase in coercivity (up to 300 %) was observed at room
+temperature as the width of Hall bar was reduced. The large coercivity
+enhancement was attributed to the relaxation of film stress. The effect of
+strain and dimensionality on the coercivity in TbFeCo makes it attractive for
+tunable coercivity and the magnetization reversal in future nanoscale devices.",1307.0057v1
+2013-07-07,Inverse effect of magnetostriction in magnetoelectric laminates,"We introduce the notion of inverse effect of magnetostriction for
+magnetostrictive/piezoelectric heterostructures and study this effect
+theoretically and experimentally. It is shown that the inverse effect of
+magnetostriction may crucially contribute to the mechanism of magnetoelectric
+coupling. It is shown that the studied effect essentially modifies the
+saturation magnetostriction of the whole structure as compared to its magnetic
+phase bulk and also induces an additional magnetic anisotropy. Our
+consideration provides useful insight into the fundamental issue of
+strain-mediated magnetoelectric coupling. Understanding this effect may lead to
+its utilization in original experimental concepts and the improvement of the ME
+coupling.",1307.1868v2
+2013-07-08,Spin thermopower in the overscreened Kondo model,"We study the spin thermopower in the two-channel spin-1/2 Kondo model which
+exhibits the phenomenon of impurity spin overscreening and non-Fermi-liquid
+properties. While magnetic field lower than the Kondo temperature does not
+strongly polarize the impurity spin, we show that it nevertheless strongly
+affects the low-energy part of the spectral function. In turn, this leads to
+characteristic saturation of the spin Seebeck coefficient at the value of
+0.388kB/|e| at T ~ T*, where T* ~ B^2/TK is the scale of the crossover between
+the intermediate-temperature non-Fermi-liquid regime and the low-temperature
+Fermi-liquid regime. We show that measuring the spin thermopower at low
+magnetic fields would provide a sensitive test for distinguishing regular Fermi
+liquid, singular Fermi liguid, and non-Fermi liquid behaviour in nanodevices.",1307.2273v1
+2013-07-15,Weak Antilocalization and Linear Magnetoresistance in The Surface State of SmB6,"Strongly correlated Kondo insulator SmB6 is known for its peculiar low
+temperature residual conduction, which has recently been demonstrated to arise
+from a robust metallic surface state, as predicted by the theory of topological
+Kondo insulator (TKI). Photoemission, quantum oscillation and magnetic doping
+experiments have provided evidence for the Dirac-like dispersion and
+topological protection. Questions arise as whether signatures of spin-momentum
+locking and electron interaction could be resolved in transport measurements.
+Here we report metallic conduction of surface state down to mK temperatures
+with saturation behaviors suggestive of Kondo effect. We observe in the surface
+state the weak-antilocalization (WAL) effect that is in agreement with a
+spin-momentum locked metallic surface. At larger perpendicular magnetic fields,
+the surface state exhibits an unusual linear magnetoresistance similar to those
+found in Bi-based topological insulators and in graphene. (Correspondence to:
+xia.jing@uci.edu)",1307.4133v1
+2013-08-30,Energy dissipation of moved magnetic vortices,"A two-dimensional easy-plane ferromagnetic substrate, interacting with a
+dipolar tip which is magnetised perpendicular with respect to the easy plane is
+studied numerically by solving the Landau-Lifshitz Gilbert equation. The
+dipolar tip stabilises a vortex structure which is dragged through the system
+and dissipates energy. An analytical expression for the friction force in the
+v$\rightarrow$0-limit based on the Thiele equation is presented. The
+limitations of this result which predicts a diverging friction force in the
+thermodynamic limit, are demonstrated by a study of the size dependence of the
+friction force. While for small system sizes the dissipation depends
+logarithmically on the system size, it saturates at a specific velocity
+dependent value. This size can be regarded as an effective vortex size and it
+is shown how this effective vortex size agrees with the infinite extension of a
+vortex in the thermodynamic limit. A magnetic friction number is defined which
+represents a general criterion for the validity of the Thiele equation and
+quantifies the degree of nonlinearity in the response of a driven spin
+configuration.",1308.6714v1
+2013-09-10,Magnetoresistance evidence on surface state and field-dependent bulk gap in Kondo insulator SmB6,"Recently, the resistance saturation at low temperature in Kondo insulator
+SmB6, a long-standing puzzle in condensed matter physics, was proposed to
+originate from topological surface state. Here,we systematically studied the
+magnetoresistance of SmB6 at low temperature up to 55 Tesla. Both temperature-
+and angular-dependent magnetoresistances show a similar crossover behavior
+below 5 K. Furthermore, the angular-dependent magnetoresistance on different
+crystal face confirms a two-dimensional surface state as the origin of
+magnetoresistances crossover below 5K. Based on two-channels model consisting
+of both surface and bulk states, the field-dependence of bulk gap with critical
+magnetic field (Hc) of 196 T is extracted from our temperature-dependent
+resistance under different magnetic fields. Our results give a consistent
+picture to understand the low-temperature transport behavior in SmB6,
+consistent with topological Kondo insulator scenario.",1309.2378v3
+2013-09-16,Epitaxial Growth of Spinel Cobalt Ferrite Films on MgAl$_2$O$_4$ Substrates by Direct Liquid Injection Chemical Vapor Deposition,"The direct liquid injection chemical vapor deposition (DLI-CVD) technique has
+been used for the growth of cobalt ferrite (CFO) films on (100)-oriented
+MgAl$_2$O$_4$ (MAO) substrates. Smooth and highly epitaxial cobalt ferrite thin
+films, with the epitaxial relationship $\mathrm{MAO} (100)\:[001] \parallel
+\mathrm{CFO} (100)\:[001]$, are obtained under optimized deposition conditions.
+The films exhibit bulk-like structural and magnetic properties with an
+out-of-plane lattice constant of $8.370\;\mathrm{\AA}$ and a saturation
+magnetization of $420\;\mathrm{kA/m}$ at room temperature. The Raman spectra of
+films on MgAl$_2$O$_4$ support the fact that the Fe$^{3+}$- and the
+Co$^{2+}$-ions are distributed in an ordered fashion on the B-site of the
+inverse spinel structure. The DLI-CVD technique has been extended for the
+growth of smooth and highly oriented cobalt ferrite thin films on a variety of
+other substrates, including MgO, and piezoelectric lead magnesium niobate-lead
+titanate and lead zinc niobate-lead titanate substrates.",1309.4031v1
+2013-10-18,Transverse Demagnetization Dynamics of a Unitary Fermi Gas,"Understanding the quantum dynamics of strongly interacting fermions is a
+problem relevant to diverse forms of matter, including high-temperature
+superconductors, neutron stars, and quark-gluon plasma. An appealing benchmark
+is offered by cold atomic gases in the unitary limit of strong interactions.
+Here we study the dynamics of a transversely magnetized unitary Fermi gas in an
+inhomogeneous magnetic field. We observe the demagnetization of the gas, caused
+by diffusive spin transport. At low temperatures, the diffusion constant
+saturates to the conjectured quantum-mechanical lower bound $\simeq \hbar/m$,
+where $m$ is the particle mass. The development of pair correlations,
+indicating the transformation of the initially non-interacting gas towards a
+unitary spin mixture, is observed by measuring Tan's contact parameter.",1310.5140v2
+2013-11-06,"The synthesis and characterization of 1111-type diluted magnetic semiconductors (La1-xSrx)(Zn1-xTMx)AsO (TM = Mn, Fe, Co)","The doping effect of Sr and transition metals Mn, Fe, Co into the direct-gap
+semiconductor LaZnAsO has been investigated. Our results indicate that the
+single phase ZrCuSiAs-type tetragonal crystal structure is preserved in
+(La1-xSrx)(Zn1-xTMx)AsO (TM = Mn, Fe, Co) with the doping level up to x = 0.1.
+While the system remains semiconducting, doping with Sr and Mn results in
+ferromagnetic order with TC ~ 30K, and doping with Sr and Fe results in a spin
+glass like state below ~6K with a saturation moment of ~0.02 muB/Fe, an order
+of magnitude smaller than the ~0.4 muB/Mn of Sr and Mn doped samples. The same
+type of magnetic state is observed neither for (Zn,Fe) substitution without
+carrier doping, nor for Sr and Co doped specimens.",1311.1304v1
+2013-11-12,Growth of (CH$_3$)$_2$NH$_2$CuCl$_3$ single crystals using evaporation method with different temperatures and solvents,"The bulk single crystals of of low-dimensional magnet
+(CH$_3$)$_2$NH$_2$CuCl$_3$ (DMACuCl$_3$ or MCCL) are grown by a slow
+evaporation method with different kinds of solvents, different degrees of
+super-saturation of solution and different temperatures of solution,
+respectively. Among three kinds of solvent, methanol, alcohol and water,
+alcohol is found to be the best one for growing MCCL crystals because of its
+structural similarity to the raw materials and suitable evaporation rate. The
+best growth temperature is in the vicinity of 35 $^{\circ}$C. The problem of
+the crystals deliquescing in air has been solved through recrystallization
+process. The crystals are characterized by means of x-ray diffraction, specific
+heat and magnetic susceptibility.",1311.2680v1
+2013-12-05,Vortex-crystal pattern in an anti-artificial spin ice system,"We have proposed in this work an original system composed by anti-dots
+nanopatterned in a ferromagnetic thin film, mimicking negatively the structure
+of an articial spin ice. In the hysteresis loop we notice the emergency of an
+anisotropy in the magnetization saturation and in the micromagnetic
+simulations, in the beginning of the hysteresis loop (relaxation), the
+formation of a vortex crystal array with vortices in diferent positions
+possessing random polarization and chirality. The crystal of vortices in this
+electrically connected sample could be most eficient than those observed in
+non-connected nanodiscs for current-driven or magnetic vortices switching by
+electric currents.",1312.1646v1
+2014-03-10,Microwave saturation spectroscopy of nitrogen-vacancy ensembles in diamond,"Negatively-charged nitrogen-vacancy (NV$^-$) centers in diamond have
+generated much recent interest for their use in sensing. The sensitivity
+improves when the NV ground-state microwave transitions are narrow, but these
+transitions suffer from inhomogeneous broadening, especially in high-density NV
+ensembles. To better understand and remove the sources of broadening, we
+demonstrate room-temperature spectral ""hole burning"" of the NV ground-state
+transitions. We find that hole burning removes the broadening caused by
+magnetic fields from $^{13}$C nuclei and demonstrate that it can be used for
+magnetic-field-insensitive thermometry.",1403.2119v1
+2014-03-25,The deceiving delta: on the equilibrium dependent dynamics of nonlinear magnetic islands,"The linear stability parameter delta is commonly used as a figure of merit
+for the nonlinear dynamics of the tearing mode. It is shown, through state of
+the art numerical simulations, that factors other than delta can play a very
+important role in determining the evolution of nonlinear magnetic islands. In
+particular, two different equilibria are analysed and it is shown that, once
+perturbed, they have a qualitatively and quantitatively different response
+despite the fact that they are characterised by the same delta. The different
+behaviour can still be associated with linear properties of the equilibrium. It
+is also studied how the nonlinear and saturation phase are affected by an
+increasing delta in the two equilibria. As the instability drive is increased,
+the systems move from a dynamics characterised by a ""universal"" generalised
+Rutherford equation to a Y-point configuration and then to a plasmoid unstable
+Y-point. Finally, for even larger delta the second harmonic overcomes the
+fundamental,leading to an interesting double island structure.",1403.6376v1
+2014-05-07,Anisotropic giant magnetoresistance in NbSb2,"The extremely large transverse magnetoreistance (the magnetoresistant ratio
+$\sim 1.3\times10^5\%$ in 2 K and 9 T field, and $4.3\times 10^6\%$ in 0.4 K
+and 32 T field, without saturation), and the metal-semiconductor crossover
+induced by magnetic field, are reported in NbSb$_2$ single crystal with
+electric current parallel to the $b$-axis. The metal-semiconductor crossover is
+preserved when the current is along the $ac$-plane but the magnetoresistant
+ratio is significantly suppressed. The sign reversal of the Hall resistivity in
+the field close to the crossover point, and the electronic structure
+calculation reveals the coexistence of a small number of holes with very high
+mobility and a large number of electrons with low mobility. These effects are
+attributed to the change of the Fermi surface induced by the magnetic field.",1405.1719v2
+2014-05-12,Characterization of spin-orbit interactions of GaAs heavy holes using a quantum point contact,"We present transport experiments performed in high quality quantum point
+contacts embedded in a GaAs two-dimensional hole gas. The strong spin-orbit
+interaction results in peculiar transport phenomena, including the previously
+observed anisotropic Zeeman splitting and level-dependent effective g-factors.
+Here we find additional effects, namely the crossing and the anti-crossing of
+spin-split levels depending on subband index and magnetic field direction. Our
+experimental observations are reconciled in an heavy hole effective spin-orbit
+Hamiltonian where cubic- and quadratic-in-momentum terms appear. The spin-orbit
+components, being of great importance for quantum computing applications, are
+characterized in terms of magnitude and spin structure. In the light of our
+results, we explain the level dependent effective g-factor in an in-plane
+field. Through a tilted magnetic field analysis, we show that the QPC
+out-of-plane g-factor saturates around the predicted 7.2 bulk value.",1405.2981v2
+2014-05-16,Quantum Otto heat engine based on a multiferroic chain working substance,"We study a quantum Otto engine operating on the basis of a helical spin- 1/2
+multiferroic chain with strongly coupled magnetic and ferroelectric order
+parameters. The presence of a finite spin chirality in the working substance
+enables steering of the cycle by an external electric field that couples to the
+electric polarization. We observe a direct connection between the chirality,
+the entanglement and the efficiency of the engine. An electric-field dependent
+threshold temperature is identified above which the pair correlations in the
+system, as quantified by the thermal entanglement, diminish. In contrast to the
+pair correlations, the collective many-body thermal entanglement is less
+sensitive to the electric field, and in the high temperature limit converges to
+a constant value. We also discuss the correlations between the threshold
+temperature of the pair entanglement, the spin chirality and the minimum of the
+fidelities in relation to the electric and magnetic fields. The efficiency of
+the quantum Otto cycle shows a saturation plateau with increasing electric
+field amplitude.",1405.4162v2
+2014-10-26,Dynamics of single-domain magnetic particles at elevated temperatures,"A stochastic differential equation that describes the dynamics of
+single-domain magnetic particles at any temperature is derived using a
+classical formalism. The deterministic terms recover existing theory and the
+stochastic process takes the form of a mean-reverting random walk. In the
+ferromagnetic state diffusion is predominantly angular and the relevant
+diffusion coefficient increases linearly with temperature before saturating at
+the Curie point ($T_c$). Diffusion in the macrospin magnitude, while
+vanishingly small at room temperature, increases sharply as the system
+approaches $T_c$. Beyond $T_c$, in the paramagnetic state, diffusion becomes
+isotropic and independent of temperature. The stochastic macrospin model agrees
+well with atomistic simulations.",1410.6980v4
+2014-11-14,Parametric instability of classical Yang-Mills fields in a color magnetic background,"We investigate instabilities of classical Yang-Mills fields in a
+time-dependent spatially homogeneous color magnetic background field in a
+non-expanding geometry for elucidating the earliest stage dynamics of
+ultra-relativistic heavy-ion collisions. The background gauge field
+configuration considered in this article is spatially homogeneous and
+temporally periodic, and is alluded by Berges-Scheffler-Schlichting-Sexty
+(BSSS). We discuss the whole structure of instability bands of fluctuations
+around the BSSS background gauge field on the basis of Floquet theory, which
+enables us to discuss the stability in a systematic way. We find various
+instability bands on the $(p_z, p_T)$-plane. These instability bands are caused
+by parametric resonance despite the fact that the momentum dependence of the
+growth rate for $|\mathbf{p}| \leq \sqrt{B}$ is similar to a Nielsen-Olesen
+instability. Moreover, some of instability bands are found to emerge not only
+in the low momentum but also in the high momentum region; typically of the
+order of the saturation momentum as $|\mathbf{p}| \sim \sqrt{B} \sim Q_{\rm
+s}$.",1411.3809v3
+2015-01-12,Nonlinear spin diffusion and spin rotation in a trapped Fermi gas,"Transverse spin diffusion in a polarized, interacting Fermi gas leads to the
+Leggett-Rice effect, where the spin current precesses around the local
+magnetization. With a spin-echo sequence both the transverse diffusivity and
+the spin-rotation parameter $\gamma$ are obtained; the sign of $\gamma$ reveals
+the repulsive or attractive character of the effective interaction. In a
+trapped Fermi gas the spin diffusion equations become nonlinear, and their
+numerical solution exhibits an inhomogeneous spin state even at the spin echo
+time. While the microscopic diffusivity and $\gamma$ increase at weak coupling,
+their apparent values inferred from the trap-averaged magnetization saturate in
+agreement with a recent experiment for a dilute ultracold Fermi gas.",1501.02677v2
+2015-01-13,Doping control of realization of an extended Nagaoka ferromagnetic state from the Mott state,"Inspired by the Nagaoka ferromagnetism, we propose an itinerant model to
+study the transition between the Mott singlet state and a ferromagnetic state
+by emulating a doping process in finite lattices. In the Nagaoka
+ferromagnetism, the total spin of the system takes the maximum value when an
+electron is removed from the half-filled system. To incorporate a procedure of
+the electron removal, our model contains extra sites as a reservoir of
+electrons, and the chemical potential of the reservoir controls the
+distribution of electrons. As a function of the chemical potential, the system
+exhibits ground-state phase transitions among various values of the total spin,
+including a saturated ferromagnetic state due to the Nagaoka mechanism at
+finite hole density. We discuss the nature of the ferromagnetism by measuring
+various physical quantities, such as the distribution of electrons, the spin
+correlation functions, the magnetization process in the magnetic field, and
+also the entanglement entropy.",1501.02899v1
+2015-02-09,Angular Momentum Transport and Particle Acceleration during Magnetorotational Instability in a Kinetic Accretion Disk,"Angular momentum transport and particle acceleration during the
+magnetorotational instability (MRI) in a collisionless accretion disk are
+investigated using three-dimensional particle-in-cell (PIC) simulation. We show
+that the kinetic MRI can provide not only high energy particle acceleration but
+also enhancement of angular momentum transport. We find that the plasma
+pressure anisotropy inside the channel flow with $p_{\|} > p_{\perp}$ induced
+by active magnetic reconnection suppresses the onset of subsequent
+reconnection, which in turn leads to high magnetic field saturation and
+enhancement of Maxwell stress tensor of angular momentum transport. Meanwhile,
+during the quiescent stage of reconnection the plasma isotropization progresses
+in the channel flow, and the anisotropic plasma with $p_{\perp} > p_{\|}$ due
+to the dynamo action of MRI outside the channel flow contributes to rapid
+reconnection and strong particle acceleration. This efficient particle
+acceleration and enhanced angular momentum transport in a collisionless
+accretion disk may explain the origin of high energy particles observed around
+massive black holes.",1502.02452v1
+2015-04-13,Spin-entropy contribution to thermopower in the [Ca$_2$CoO$_{3-t}$]$_{0.62}$(CoO$_2$) misfits,"Two samples of the [Ca$_2$CoO$_{3-t}$]$_{0.62}$(CoO$_2$) misfit cobaltate,
+often denoted as the Ca$_{3}$Co$_{3.93}$O$_{9}$ phase, were prepared from the
+same ceramic material by the oxygen and argon annealing, resulting in different
+carrier concentrations in the conducting CoO$_{2}$ layers, n=0.31 and 0.19
+hole/Co, respectively. Electrical and thermal transport properties were studied
+in dependence of magnetic field up to 140 kOe. The magnetothermopower data
+reveal an extra spin-entropy contribution to Seebeck coefficient that is not
+expected for carriers of Fermi liquid character. Its magnitude is
+unprecedentedly large and makes at zero field up to 50$\%$ of the theoretical
+limit k$_B$/$e$ ln2$ = 59 \mu VK^{-1}$. This spin-entropy contribution is
+gradually suppressed with increasing magnetic field, and the saturation is even
+observed when temperatures are low enough. To understand the results, the
+thermopower is treated in terms of purely thermodynamic Kelvin formula, and
+so-called Spin liquid model is evoked, providing a reason for the spin-entropy
+manifestation in the [Ca$_2$CoO$_{3-t}$]$_{0.62}$(CoO$_2$) misfits.",1504.03104v2
+2015-04-21,New memory devices based on the proton transfer process,"Memory devices operating due to the fast proton transfer (PT) process are
+proposed by means of the first-principles calculations. Writing an information
+is performed using the electrostatic potential of the scanning tunneling
+microscopy (STM). Reading an information is based on the effect of the local
+magnetization induced at the zigzag graphene nanoribbon (Z-GNR) edge -
+saturated with oxygen or the hydroxy group - and can be realized with the use
+of the giant magnetoresistance (GMR), magnetic tunnel junction (MTJ) or
+spin-transfer torque (STT) devices. The energetic barriers for the hop-forward
+and -backward processes can be tuned by the distance and potential of the STM
+tip. Thus, enabling to tailor the non-volatile logic states. The proposed
+system enables very dense packing of the logic cells and could be used in the
+random access and flash memory devices.",1504.05607v2
+2015-04-23,Three-Dimensional Crystallization of Vortex Strings in Frustrated Quantum Magnets,"We demonstrate that frustrated exchange interactions can produce exotic 3D
+crystals of vortex strings near the saturation field (H=Hsat) of body- and
+face-centered cubic Mott insulators. The combination of cubic symmetry and
+frustration leads to a magnon spectrum of the fully polarized spin state
+(H>Hsat) with degenerate minima at multiple noncoplanar Q vectors. This
+spectrum becomes gapless at the quantum critical point H=Hsat and the magnetic
+ordering below Hsat can be formally described as a condensate of a dilute gas
+of bosons. By expanding in the lattice gas parameter, we find that different
+vortex crystals span sizable regions of the phase diagrams for isotropic
+exchange and are further stabilized by symmetric exchange anisotropy.",1504.06270v2
+2015-06-23,Spin polarization studies in half-metallic Co2TiX (X = Ge and Sn) Heusler alloys,"In this paper, we investigated the Co2TiX (X = Ge, Sn) Heusler alloys by
+structural, magnetic and spin polarization measurements to probe the
+half-metallic nature. Alloys are synthesized using the arc melting technique,
+and found to exist in L21 crystal structure with Fm-3m space group. Curie
+temperature (TC) is found to be 384 and 371 K for Co2TiGe and Co2TiSn
+respectively. The saturation magnetization (MS) value of 1.8 and 2.0 Bohr
+magneton/f.u. are obtained at 5 K for for Co2TiGe and Co2TiSn respectively,
+compared to 2.0 Bohr magneton/f.u. calculated by Slater-Pauling rule. To obtain
+the spin polarization value, differential conductance curves are recorded at
+the ferromagnetic/superconducting point contact at 4.2 K. The current spin
+polarization (P) value of 0.63 and 0.64 are deduced for Co2TiGe and Co2TiSn
+respectively. Considering the high current spin polarization and TC, these
+materials appear to be promising for spintronic devices.",1506.07109v1
+2015-07-13,Majorana Fermi Sea in Insulating SmB6: A proposal and a Theory of Quantum Oscillations in Kondo Insulators,"In an exciting development, SmB6, a Kondo insulator has been shown to exhibit
+bulk quantum oscillations. We propose that SmB6 is a bulk scalar Majorana Fermi
+Liquid} (MFL) with a finite gap for charge and spin excitations. In their study
+of Kondo insulators in 1993, Coleman, Miranda and Tsvelik (CMT) envisaged such
+a remarkable possibility, using a mean field ansatz. We generalize CMT theory
+to non-zero magnetic fields and show a counter intuitive result that the scalar
+Majorana fermi liquid, while remaining electrically insulating, responds to
+external magnetic field and exhibits Landau diamagnetism and quantum
+oscillations. Physics of an emergent compactified 2-channel Kondo lattice
+physics that is behind formation of the novel scalar Majorana fermi liquid
+phase is discussed. It is also suggested that a known resistivity saturation in
+SmB6 as well as a new strong deviation of quantum oscillation amplitude from
+Lifshitz-Kosevich formula in SmB6 at low temperatures are due to a coherent
+fluctuation of charge of a neutral scalar Majorana fermion. Possible presence
+of 2-dimensional Majorana fermion excitations in surfaces of SmB6, and other
+Topological Kondo Insulators (TKI) is pointed out.",1507.03477v1
+2015-07-22,Magnetic field decay in normal radio pulsars,"We analyse the origin of the magnetic field decay in normal radio pulsars
+found by us in a recent study. This decay has a typical time scale $\sim 4
+\times 10^5$~yrs, and operates in the range $\sim 10^5$~--~few$\times
+10^5$~yrs. We demonstrate that this field evolution may be either due to the
+Ohmic decay related to the scattering from phonons, or due to the Hall cascade
+which reaches the Hall attractor. According to our analysis the first
+possibility seems to be more reliable. So, we attribute the discovered field
+decay mainly to the Ohmic decay on phonons which is saturated at the age
+few$\times 10^5$~yrs, when a NS cools down to the critical temperature below
+which the phonon scattering does not contribute much to the resistivity of the
+crust. Some role of the Hall effect and attractor is not excluded, and will be
+analysed in our further studies.",1507.07962v1
+2015-09-04,Spin frustration and fermionic entanglement in an exactly solved hybrid diamond chain with the localized Ising spins and mobile electrons,"The strongly correlated spin-electron system on a diamond chain containing
+localized Ising spins on its nodal lattice sites and mobile electrons on its
+interstitial sites is exactly solved in a magnetic field using the
+transfer-matrix method. We have investigated in detail all available ground
+states, the magnetization processes, the spin-spin correlation functions around
+an elementary plaquette, fermionic quantum concurrence and spin frustration. It
+is shown that the fermionic entanglement between mobile electrons hopping on
+interstitial sites and the kinetically-induced spin frustration are closely
+related yet independent phenomena. In the ground state, quantum entanglement
+only appears within a frustrated unsaturated paramagnetic phase, while thermal
+fluctuations can promote some degree of quantum entanglement above the
+non-frustrated ground states with saturated paramagnetic or classical
+ferrimagnetic spin arrangements.",1509.01639v1
+2015-09-07,Successively Thresholded Domain Boundary Roughening Driven by Pinning Centers and Missing Bonds: Hard-Spin Mean-Field Theory Applied to d=3 Ising Magnets,"Hard-spin mean-field theory has recently been applied to Ising magnets,
+correctly yielding the absence and presence of an interface roughening
+transition respectively in $d=2$ and $d=3$ dimensions and producing the
+ordering-roughening phase diagram for isotropic and anisotropic systems. The
+approach has now been extended to the effects of quenched random pinning
+centers and missing bonds on the interface of isotropic and anisotropic Ising
+models in $d=3$. We find that these frozen impurities cause domain boundary
+roughening that exhibits consecutive thresholding transitions as a function
+interaction of anisotropy. For both missing-bond and pinning-center impurities,
+for moderately large values the anisotropy, the systems saturate to the
+""solid-on-solid"" limit, exhibiting a single universal curve for the domain
+boundary width as a function of impurity concentration.",1509.01910v2
+2015-10-13,Nematic magnetoelastic effect contrasted between Ba(Fe$_{1-x}$Co$_{x}$)$_2$As$_2$ and FeSe,"To elucidate the origin of nematic order in Fe-based superconductors, we
+report a Raman scattering study of lattice dynamics, which quantify the extent
+of $C_4$-symmetry breaking, in BaFe$_2$As$_2$ and FeSe. FeSe possesses a
+nematic ordering temperature $T_\mathrm{s}$ and orbital-related band-energy
+split below $T_\mathrm{s}$ that are similar to those in BaFe$_2$As$_2$, but
+unlike BaFe$_2$As$_2$ it has no long-range magnetic order. We find that the
+$E_g$ phonon-energy split in FeSe sets in only well below $T_\mathrm{s}$, and
+its saturated value is substantially smaller than that in BaFe$_2$As$_2$.
+Together with reported results for the Ba(Fe$_{1-x}$Co$_{x}$)$_2$As$_2$ family,
+the data suggest that magnetism exerts a major influence on the lattice.",1510.03526v1
+2015-11-07,Production of Semi Quark Gluon Monopole Plasma by Glasma Decay,"Using the standard Lagrangian of gluons and a model of dual superconductor
+for magnetic monopoles, we calculate the number densities of the gluons and
+monopoles produced by the decay of background color electric $E$ and magnetic
+$B$ fields ( glasma ). We find that gluons are dominant decay products when the
+initial values of the gauge fields are large such that
+$gE=gB>(0.5\mbox{GeV})^2$, while they are suppressed and monopoles are dominant
+decay products when the initial values are small such that
+$gE=gB<(0.4\mbox{GeV})^2$. The feature of the gluon dominance at large $gE=gB$
+and the monopole dominance at small $gE=gB$ is similar to the one of
+thermalized quark gluon monopole plasmas proposed recently, if we identify
+$\sqrt{gE}=\sqrt{gB}$ as temperatures of the plasmas. Although the model of the
+monopoles is phenomenological, our analysis suggests that the monopoles play
+important roles in the decay of the glasmas with small saturation momenta, to
+which classical statistical field theories are not applicable.",1511.02271v2
+2015-11-15,Exotic Superconducting Properties in Topological Nodal Semimetal PbTaSe$_2$,"We report the electronic properties of superconductivity in the topological
+nodal-line semimetal PbTaSe$_2$. Angle-resolved photoemission measurements
+accompanied by band calculations confirmed the nodal-line band structure in the
+normal state of single crystalline PbTaSe$_2$. Resistivity,
+magnetic-susceptibility and specific heat measurements have also been performed
+on high-quality single crystals. We observed upward features and large
+anisotropy in upper critical field ($H_{c2}$) measured in-plane
+(H//\textbf{ab}) and out-plane (H//\textbf{c}), respectively. Especially,
+$H_{c2}$ measured in H//\textbf{ab} shows sudden upward features rather than a
+signal of saturation in ultralow temperatures. The specific heat measurements
+under magnetic field reveal a full superconducting gap with no gapless nodes.
+These behaviors in this clean noncentrosymmetric superconductor is possibly
+related to the underlying exotic physics, providing important clue for
+realization of topological superconductivity.",1511.04673v2
+2015-12-30,D mesons in a magnetic field,"We investigate the mass spectra of open heavy flavor mesons in an external
+constant magnetic field within QCD sum rules. Spectral ans\""atze on the
+phenomenological side are proposed in order to properly take into account
+mixing effects between the pseudoscalar and vector channels, and the Landau
+levels of charged mesons. The operator product expansion is implemented up to
+dimension-5 operators. As a result, we find for neutral D mesons a significant
+positive mass shift that goes beyond simple mixing effects. In contrast,
+charged D mesons are further subject to Landau level effects, which together
+with the mixing effects almost completely saturate the mass shifts obtained in
+our sum rule analysis.",1512.08864v2
+2016-01-10,"Interfacial Dzyaloshinskii-Moriya interaction, surface anisotropy energy,and spin pumping at spin orbit coupled Ir/Co interface","The interfacial Dzyaloshinskii-Moriya interaction (iDMI), surface anisotropy
+energy, and spin pumping at the Ir/Co interface are experimentally investigated
+by performing Brillouin light scattering. Contrary to previous reports, we
+suggest that the sign of the iDMI at the Ir/Co interface is the same as in the
+case of the Pt/Co interface. We also find that the magnitude of the iDMI energy
+density is relatively smaller than in the case of the Pt/Co interface, despite
+the large strong spin-orbit coupling (SOC) of Ir. The saturation magnetization
+and the perpendicular magnetic anisotropy (PMA) energy are significantly
+improved due to a strong SOC. Our findings suggest that an SOC in an Ir/Co
+system behaves in different ways for iDMI and PMA. Finally, we determine the
+spin pumping effect at the Ir/Co interface, and it increases the Gilbert
+damping constant from 0.012 to 0.024 for 1.5 nmthick Co.",1601.02210v3
+2016-01-14,P-shell carriers assisted dynamic nuclear spin polarization in single quantum dots at zero external magnetic field,"Repeated injection of spin polarized carriers in a quantum dot leads to the
+polarization of nuclear spins, a process known as dynamic nuclear spin
+polarization (DNP). Here, we report the first observation of p-shell carrier
+assisted DNP in single QDs at zero external magnetic field. The nuclear field -
+measured by using the Overhauser shift of the singly charged exciton state of
+the QDs - continues to increase, even after the carrier population in the
+s-shell saturates. This is also accompanied by an abrupt increase in nuclear
+spin buildup time as p-shell emission overtakes that of the s-shell. We
+attribute the observation to p-shell electrons strongly altering the nuclear
+spin dynamics in the QD, supported by numerical simulation results based on a
+rate equation model of coupling between electron and nuclear spin system. DNP
+with p-shell carriers could open up avenues for further control to increase the
+degree of nuclear spin polarization in QDs.",1601.03480v2
+2016-01-18,Large and exact quantum degeneracy in a Skyrmion magnet,"We identify a large family of ground states of a topological Skyrmion magnet
+whose classical degeneracy persists to all orders in a semiclassical expansion.
+This goes along with an exceptional robustness of the concomitant ground state
+configurations, which are not at all dressed by quantum fluctuations. We trace
+these twin observations back to a common root: this class of topological ground
+states saturates a Bogomolny inequality. A similar phenomenology occurs in
+high-energy physics for some field theories exhibiting supersymmetry. We
+propose quantum Hall ferromagnets, where these Skyrmions configurations arise
+naturally as ground states away from integer filling, as the best available
+laboratory realisations.",1601.04645v1
+2016-02-17,Fractional Spin Fluctuation as a Precursor of Quantum Spin Liquids: Majorana Dynamical Mean-Field Study for the Kitaev Model,"Experimental identification of quantum spin liquids remains a challenge, as
+the pristine nature is to be seen in asymptotically low temperatures. We here
+theoretically show that the precursor of quantum spin liquids appears in the
+spin dynamics in the paramagnetic state over a wide temperature range. Using
+the cluster dynamical mean-field theory and the continuous-time quantum Monte
+Carlo method, which are newly developed in the Majorana fermion representation,
+we calculate the dynamical spin structure factor, relaxation rate in nuclear
+magnetic resonance, and magnetic susceptibility for the honeycomb Kitaev model
+whose ground state is a canonical example of the quantum spin liquid. We find
+that dynamical spin correlations show peculiar temperature and frequency
+dependence even below the temperature where static correlations saturate. The
+results provide the experimentally-accessible symptoms of the fluctuating
+fractionalized spins evincing the quantum spin liquids.",1602.05253v2
+2016-03-15,"Footprints of hyperfine, spin-orbit, and decoherence effects in Pauli spin blockade","We detect in real time inter-dot tunneling events in a weakly coupled two
+electron double quantum dot in GaAs. At finite magnetic fields, we observe two
+characteristic tunneling times, T_d and T_b, belonging to, respectively, a
+direct and a blocked (spin-flip-assisted) tunneling. The latter corresponds to
+lifting of a Pauli spin blockade and the tunneling times ratio eta=T_b/T_d
+characterizes the blockade efficiency. We find pronounced changes in the
+behavior of eta upon increasing the magnetic field, with eta increasing,
+saturating and increasing again. We explain this behavior as due to the
+crossover of the dominant blockade lifting mechanism from the hyperfine to
+spin-orbit interactions and due to a change in the contribution of the charge
+decoherence.",1603.04861v1
+2016-03-17,Linear and nonlinear magneto-optical rotation on the narrow strontium intercombination line,"In the presence of an external static magnetic field, an atomic gas becomes
+optically active, showing magneto-optical rotation. In the saturated regime,
+the coherences among the excited substates give a nonlinear contribution to the
+rotation of the light polarization. In contrast with the linear magneto-optical
+rotation, the nonlinear counterpart is insensitive to Doppler broadening. By
+varying the temperature of a cold strontium gas, we observe both regimes by
+driving the $J=0\rightarrow J=1$ transition on the intercombination line. For
+this narrow transition, the sensitivity to the static magnetic field is
+typically three orders of magnitude larger than for a standard broad alkali
+transition.",1603.05425v1
+2016-04-29,Hydrostatic pressure tuned magneto-structural transition and occurrence of pressure induced exchange bias effect in Mn$_{0.85}$Fe$_{0.15}$NiGe alloy,"Magnetic and magneto-functional behavior of a Fe-doped MnNiGe alloy with
+nominal composition Mn$_{0.85}$Fe$_{0.15}$NiGe have been investigated in
+ambient as well as in high pressure condition. The alloy undergoes first order
+martensitic phase transition (MPT) around 200 K and also shows large
+conventional magnetocaloric effect (MCE) ($\Delta S$ $\sim$ -21 J/kg-K for
+magnetic field ($H$) changing from 0-50 kOe) around the transition in ambient
+condition. Application of external hydrostatic pressure ($P$) results a shift
+in MPT towards the lower temperature and a clear decrease in the saturation
+moment of the alloy at 5 K. The peak value of MCE is also found to decrease
+with increasing external $P$ ($\sim$ 18 J/kg-K decrease in $\Delta S$ has been
+observed for $P$ = 12.5 kbar). The most interesting observation is the
+occurance of exchange bias effect (EBE) on application of external $P$. The
+competing ferromagnetic and antiferromagnetic interaction in presence of
+external $P$ plays the pivotal role towards the observation of $P$ induced EBE.",1604.08761v1
+2016-05-20,High-frequency behavior of FeN thin films fabricated by reactive sputtering,"We investigated high-frequency behavior of FeN thin films prepared by
+reactive sputtering through ferromagnetic resonance (FMR) and its relationship
+with the static magnetic properties. The FMR was observed in the frequency
+range from 2 to 18 GHz in the FeN films fabricated at proper nitrogen flow rate
+(NFR). In those FeN thin films, a decrease of the saturation magnetization and
+the corresponding decrease of the FMR frequency were observed as NFR was
+increased during the deposition. The external field dependences of the FMR
+frequencies were well fit to the Kittel formula and the Land\'e g-factors
+determined from the fit were found to be very close to the free electron value.
+The high-field damping parameters were almost insensitive to the growth
+condition of NFR. However, the low-field damping parameters exhibited high
+sensitivity to NFR very similar to the dependence of the hard-axis coercivity
+on NFR, suggesting that extrinsic material properties such as impurities and
+defect structures could be important in deciding the low-field damping
+behavior.",1605.06179v1
+2016-06-08,A method to decrease the harmonic distortion in Mn-Zn ferrite/PZT and Ni-Zn ferrite/PZT layered composite rings exhibiting high magnetoelectric effects,"We have investigated the magnetoelectric (ME) effect in layered composite
+rings subjected to circumferential AC magnetic fields and DC magnetic fields in
+radial, axial or circumferential directions. Bilayer samples were obtained
+combining different grades of commercial Mn-Zn ferrites or Ni-Zn ferrites with
+commercial lead zirconate titanate (PZT). Mn-Zn ferrites with low
+magnetostriction saturation () and low magneto-crystalline anisotropy constants
+show high ME capabilities when associated with PZT in ring structures. In
+certain conditions, these ME effects are higher than those obtained with
+Terfenol-D/PZT composites in the same layered ring structure. Magnetostrictive
+and mechanical characterizations have given results that explain these high ME
+performances. Nevertheless, Mn-Zn ferrite/PZT composites exhibit voltages
+responses with low linearity especially at high signal level. Based on the
+particular structure of the ME device, a method to decrease the nonlinear
+harmonic distortion of the ME voltages is proposed. Harmonic distortion
+analysis of ME voltages measured in different configurations allows us to
+explain the phenomenon.",1606.02469v1
+2016-07-20,Landau quantization and neutron emissions by nuclei in the crust of a magnetar,"Magnetars are neutron stars endowed with surface magnetic fields of the order
+of $10^{14}-10^{15}$~G, and with presumably much stronger fields in their
+interior. As a result of Landau quantization of electron motion, the
+neutron-drip transition in the crust of a magnetar is shifted to either higher
+or lower densities depending on the magnetic field strength. The impact of
+nuclear uncertainties is explored considering the recent series of
+Brussels-Montreal microscopic nuclear mass models. All these models are based
+on the Hartree-Fock-Bogoliubov method with generalized Skyrme functionals. They
+differ in their predictions for the symmetry energy coefficient at saturation,
+and for the stiffness of the neutron-matter equation of state. For comparison,
+we have also considered the very accurate but more phenomenological model of
+Duflo and Zuker. Although the equilibrium composition of the crust of a
+magnetar and the onset of neutron emission are found to be model dependent, the
+quantum oscillations of the threshold density are essentially universal.",1607.05934v1
+2016-07-28,Study of CPO resonances on the intercombination line in $^{173}$Yb,"We study coherent population oscillations (CPO) in an odd isotope of the
+two-electron atom Yb. The experiments are done using magnetic sublevels of the
+$ F_g = 5/2 \rightarrow F_e = 3/2 $ hyperfine transition in $^{173}$Yb of the $
+{\rm {^1S_0} \rightarrow {^3P_1}} $ intercombination line. The experiments are
+done both with and without an appied magnetic field. In the absence of an
+applied field, the complicated sublevel structure along with the saturated
+fluorescence effect causes the linewidth to be larger than the 190 kHz natural
+linewidth of the transition. In the presence of a field (of magnitude 330 mG),
+a well-defined quantization axis is present which results in the formation of
+two M-type systems. The total fluorescence is then limited by spin coherence
+among the ground sublevels. In addition, the pump beam gets detuned from
+resonance which results in a reduced scattering rate from the $ {\rm ^3P_1} $
+state. Both of these effects result in a reduction of the linewidth to a
+subnatural value of about 100 kHz.",1607.08331v3
+2016-07-28,Fractional magnetization plateaux of the spin-1/2 Heisenberg orthogonal-dimer chain revisited: strong-coupling approach developed from the exactly solved Ising-Heisenberg model,"The spin-1/2 Heisenberg orthogonal-dimer chain is considered within the
+perturbative strong-coupling approach, which is developed from the exactly
+solved spin-1/2 Ising-Heisenberg orthogonal-dimer chain with the Heisenberg
+intradimer and the Ising interdimer couplings. Although the spin-1/2
+Ising-Heisenberg orthogonal-dimer chain exhibits just intermediate plateaux at
+zero, one-quarter and one-half of the saturation magnetization, the
+perturbative treatment up to second order stemming from this exactly solvable
+model additionally corroborates the fractional one-third plateau as well as the
+gapless Luttinger spin-liquid phase. It is evidenced that the approximate
+results obtained from the strong-coupling approach are in an excellent
+agreement with the state-of-the-art numerical data obtained for the spin-1/2
+Heisenberg orthogonal-dimer chain within the exact diagonalization and
+density-matrix renormalization group method. The nature of individual quantum
+ground states is comprehensively studied within the developed perturbation
+theory.",1607.08457v2
+2016-09-15,Magnetoelectric Response in Multiferroic SrFe12O19 Ceramics,"We report here the realization of ferroelectricity, ferromagnetism and
+magnetocapacitance effect in SrFe12O19 ceramics at room temperature. The
+ceramics demonstrate a saturated polarization hysteresis loop, two I-V peaks
+and large anomaly of dielectric constant near Curie temperature. These
+evidences confirmed the ferroelectricity of SrFe12O19 ceramics after annealing
+in O2 atmosphere. The remnant polarization of the SrFe12O19 ceramic is 103
+{\mu}C/cm2. The material also exhibits strong ferromagnetic characterization,
+the coercive field and remnant magnetic moment are 6192Oe and 35.8emu/g,
+respectively. Subsequent annealing SrFe12O19 ceramics in O2 not only reveals
+its innate ferroelectricity but also improves the ferromagnetic properties
+through transforming Fe2+ into Fe3+. By applying a magnetic field, the
+capacitance demonstrates remarkable change along with B field, the maximum
+relative change of dielectric constant is 1174%, which reflects a giant
+magnetocapacitance effect in SrFe12O19. These combined functional responses in
+SrFe12O19 ceramics opens substantial possibilities for applications in novel
+electric devices.",1609.04483v1
+2016-09-15,Low-damping sub-10-nm thin films of lutetium iron garnet grown by molecular-beam epitaxy,"We analyze the structural and magnetic characteristics of (111)-oriented
+lutetium iron garnet (Lu$_3$Fe$_5$O$_{12}$) films grown by molecular-beam
+epitaxy, for films as thin as 2.8 nm. Thickness-dependent measurements of the
+in- and out-of-plane ferromagnetic resonance allow us to quantify the effects
+of two-magnon scattering, along with the surface anisotropy and the saturation
+magnetization. We achieve effective damping coefficients of $11.1(9) \times
+10^{-4}$ for 5.3 nm films and $32(3) \times 10^{-4}$ for 2.8 nm films, among
+the lowest values reported to date for any insulating ferrimagnetic sample of
+comparable thickness.",1609.04753v1
+2016-09-30,Pair entanglement in dimerized spin-s chains,"We examine the pair entanglement in the ground state of finite dimerized
+spin-$s$ chains interacting through anisotropic $XY$ couplings immersed in a
+transverse magnetic field, by means of a self-consistent pair mean field
+approximation. The approach, which makes no a priori assumptions on the pair
+states, predicts, for sufficiently low coupling between pairs, $2s$ distinct
+dimerized phases for increasing fields below the pair factorizing field,
+separated by spin parity breaking phases. The dimerized phases lead to
+approximate magnetization and pair entanglement plateaus, while the parity
+breaking phases are characterized by weak pair entanglement but non-negligible
+entanglement of the pair with the rest of the system. These predictions are
+confirmed by the exact results obtained in finite $s=1$ and $s=3/2$ chains. It
+is also shown that for increasing values of the spin $s$, the entanglement of
+an isolated pair, as measured by the negativity, rapidly saturates in the
+anisotropic $XY$ case but increases as $s^{1/2}$ in the $XX$ case, reflecting a
+distinct single spin entanglement spectrum.",1610.00056v2
+2016-10-05,Universal front propagation in the quantum Ising chain with domain-wall initial states,"We study the melting of domain walls in the ferromagnetic phase of the
+transverse Ising chain, created by flipping the order-parameter spins along
+one-half of the chain. If the initial state is excited by a local operator in
+terms of Jordan-Wigner fermions, the resulting longitudinal magnetization
+profiles have a universal character. Namely, after proper rescalings, the
+profiles in the noncritical Ising chain become identical to those obtained for
+a critical free-fermion chain starting from a step-like initial state. The
+relation holds exactly in the entire ferromagnetic phase of the Ising chain and
+can even be extended to the zero-field XY model by a duality argument. In
+contrast, for domain-wall excitations that are highly non-local in the
+fermionic variables, the universality of the magnetization profiles is lost.
+Nevertheless, for both cases we observe that the entanglement entropy
+asymptotically saturates at the ground-state value, suggesting a simple form of
+the steady state.",1610.01540v3
+2016-10-06,Quantum Size Effect Exponential Heat Capacity in 4 nm Natural Nickel Nanolattice,"Quantum size effect-induced heat capacity of metal nanoparticles at low
+temperatures was predicted 79 years ago to be exponential. This, however, has
+not been reported until date. In defiance, we demonstrate here observation of
+exponentially decaying heat capacity, below 45.2 K, associated with quantum
+jumps, exceptionally in 4 nm naturally assembled hexagonal closed packed (hcp)
+lattice of nickel nanoparticles; high magnetic fields have negligible effect on
+these features. Magnetic susceptibilities in contrast reveal evolution of
+quantum size effects with decrease in particle size. They exhibit sharp rise
+below about 30 K and vestiges of saturations below 5 K. The former is explained
+by Curie-like characteristics of odd electrons while the latter tend towards
+the orthogonal even-like case. These characteristics, ascribed to the ensembles
+of Ni nanoparticles, will give a new direction in understanding this crucial
+thermodynamic phenome-non.",1610.01756v1
+2016-10-27,Giant variation of the perpendicular magnetic anisotropy at Fe/MgO interfaces by oxygen migration: a first-principles study,"A characteristic dependence of voltage control of perpendicular magnetic
+anisotropy (VCMA) on oxygen migration at Fe/MgO interfaces was revealed by
+performing systematic {\it ab initio} study of the energetics of the oxygen
+path around the interface. We find that the surface anisotropy energy exhibits
+a Boltzmann sigmoidal behavior as a function of the migrated O-atoms
+concentration. The obtained variation of the VCMA efficiency factor $\beta$
+reveals a saturation limit beyond a critical concentration of migrated O, about
+$54\%$, at which the anisotropy switches from perpendicular to in plane.
+Furthermore, depending on the range of variation of the applied voltage, two
+regimes associated with reversible or irreversible ions displacement are
+predicted to occur, yielding different VCMA response. According to our
+findings, one can distinguish from the order of magnitude of $\beta$ the VCMA
+driving mechanism: an effect of several tens of fJ/(V.m) is likely associated
+to charge-mediated effect combined with slight reversible oxygen displacements
+whereas an effect of the order of thousands of fJ/(V.m) is more likely
+associated with irreversible oxygen ionic migration.",1610.08859v2
+2016-11-07,Giant coronal loops dominate the quiescent X-ray emission in rapidly rotating M stars,"Observations indicate that magnetic fields in rapidly rotating stars are very
+strong, on both small and large scales. What is the nature of the resulting
+corona? Here we seek to shed some light on this question. We use the results of
+an anelastic dynamo simulation of a rapidly rotating fully-convective M-star to
+drive a physics-based model for the stellar corona. We find that due to the
+several kilo Gauss large-scale magnetic fields at high latitudes, the corona
+and its X-ray emission are dominated by star-size large hot loops, while the
+smaller, underlying colder loops are not visible much in the X-ray. Based on
+this result we propose that, in rapidly rotating stars, emission from such
+coronal structures dominates the quiescent, cooler but saturated X-ray
+emission.",1611.02141v1
+2017-01-03,Universal Absence of Walker Breakdown and Linear Current-Velocity Relation via Spin-Orbit Torques in Coupled and Single Domain Wall Motion,"We consider theoretically domain wall motion driven by spin-orbit and spin
+Hall torques. We find that it is possible to achieve universal absence of
+Walker breakdown for all spin-orbit torques using experimentally relevant
+spin-orbit coupling strengths. For spin-orbit torques other than the pure
+Rashba spin-orbit torque, this gives a linear current-velocity relation instead
+of a saturation of the velocity at high current densities. The effect is very
+robust and is found in both soft and hard magnetic materials, as well as in the
+presence of the Dzyaloshinskii-Moriya interaction and in coupled domain walls
+in synthetic antiferromagnets, where it leads to very high domain wall
+velocities. Moreover, recent experiments have demonstrated that the switching
+of a synthetic antiferromagnet does not obey the usual spin Hall
+angle-dependence, but that domain expansion and contraction can be selectively
+controlled toggling only the applied in-plane magnetic field magnitude and not
+its sign. We show for the first time that the combination of spin Hall torques
+and interlayer exchange coupling produces the necessary relative velocities for
+this switching to occur.",1701.00786v2
+2017-02-23,Diffusionless hydromagnetic modes in rotating ellipsoids: a road to weakly nonlinear models?,"We investigate free hydromagnetic eigenmodes of an incompressible, inviscid
+and ideal electrically conducting fluid in rotating triaxial ellipsoids. The
+container rotates with an angular velocity tilted from its figure. The magnetic
+base state is a uniform current density also tilted. Three-dimensional
+perturbations upon the base state are expanded onto a finite-dimensional
+polynomial basis. By combining symbolic and numerical computations, we are able
+to get the eigenmodes of high spatial complexity. Hydromagnetic modes of the
+sphere still exist in triaxial geometry. A plane-wave analysis is also carried
+on, explaining the dispersion relation observed in our model. Without magnetic
+field, the modes reduce to the inertial modes of the ellipsoids, which form a
+complete basis. We propose to use these modes to study the weakly nonlinear
+saturation of inertial instabilities, especially the elliptical one.",1702.07198v1
+2017-04-23,Direct Observation of Attractive Skyrmions and Skyrmion Clusters in the Cubic Helimagnet Cu$_2$OSeO$_3$,"We report the discovery of attractive magnetic skyrmions and their clusters
+in non-centrosymmetric ferromagnets. These three-dimensional solitons have been
+predicted to exist in the cone phase of chiral ferromagnets (J. Phys: Condens.
+Matter 28 (2016) 35LT01) and are fundamentally different from the more common
+repulsive axisymmetric skyrmions that occur in the magnetically saturated
+state. We present real-space images of these skyrmion clusters in thin (~70 nm)
+single-crystal samples of Cu$_2$OSeO$_3$ taken using transmission electron
+microscopy and develop a phenomenological theory describing this type of
+skyrmion.",1704.06876v2
+2017-06-04,Field- and temperature-modulated spin-diode effect in a GMR nanowire with dipolar coupling,"An analytical model of the spin-diode effect induced by resonant
+spin-transfer torque in a ferromagnetic bilayer with strong dipolar coupling
+provides the resonance frequencies and the lineshapes of the magnetic field
+spectra obtained under field or laser-light modulation. The effect of laser
+irradiation is accounted for by introducing the temperature dependence of the
+saturation magnetization and anisotropy, as well as thermal spin-transfer
+torques. The predictions of the model are compared with experimental data
+obtained with single Co/Cu/Co spin valves, embedded in nanowires and produced
+by electrodeposition. Temperature modulation provides excellent signal-to-noise
+ratio. High temperature-modulation frequency is possible because these
+nanostructures have a very small heat capacity and are only weakly heat-sunk.
+The two forms of modulation give rise to qualitative differences in the spectra
+that are accounted for by the model.",1706.01036v1
+2017-06-20,Magnetic flux pumping in 3D nonlinear magnetohydrodynamic simulations,"A self-regulating magnetic flux pumping mechanism in tokamaks that maintains
+the core safety factor at $q\approx 1$, thus preventing sawteeth, is analyzed
+in nonlinear 3D magnetohydrodynamic simulations using the M3D-C$^1$ code. In
+these simulations, the most important mechanism responsible for the flux
+pumping is that a saturated $(m=1,n=1)$ quasi-interchange instability generates
+an effective negative loop voltage in the plasma center via a dynamo effect. It
+is shown that sawtoothing is prevented in the simulations if $\beta$ is
+sufficiently high to provide the necessary drive for the $(m=1,n=1)$
+instability that generates the dynamo loop voltage. The necessary amount of
+dynamo loop voltage is determined by the tendency of the current density
+profile to centrally peak which, in our simulations, is controlled by the
+peakedness of the applied heat source profile.",1706.06672v1
+2017-07-19,Single-atom transistor as a precise magnetic field sensor,"Feshbach resonances, which allow for tuning the interactions of ultracold
+atoms with an external magnetic field, have been widely used to control the
+properties of quantum gases. We propose a~scheme for using scattering
+resonances as a probe for external fields, showing that by carefully tuning the
+parameters it is possible to reach a $10^{-5}$G (or nT) level of precision with
+a single pair of atoms. We show that for our collisional setup it is possible
+to saturate the quantum precision bound with a simple measurement protocol.",1707.06018v2
+2017-07-21,Mn$_2$VAl Heusler alloy thin films: Appearance of antiferromagnetism and an exchange bias in a layered structure with Fe,"Mn$_2$VAl Heusler alloy films were epitaxially grown on MgO(100) single
+crystal substrates by means of ultra-high-vacuum magnetron sputtering. A2 and
+L2$_1$ type Mn$_2$VAl order was controlled by the deposition temperatures.
+A2-type Mn$_2$VAl films showed no spontaneous magnetization and L2$_1$-type
+Mn$_2$VAl films showed ferrimagnetic behavior with a maximum saturation
+magnetization of 220 emu/cm$^3$ at room temperature. An antiferromagnetic
+reflection was observed with neutron diffraction at room temperature for an
+A2-type Mn$_2$VAl film deposited at 400$^\circ$C. A bilayer sample of the
+antiferromagnetic A2 Mn$_2$VAl and Fe showed an exchange bias of 120 Oe at 10
+K.",1707.06731v1
+2017-08-09,Enormous sample scale-up from nanoliter to microliter in high field liquid state dynamic nuclear polarization,"Dynamic nuclear polarization (DNP) enhances nuclear magnetic resonance (NMR)
+signals by transferring electron spin polarization to nuclei. As DNP requires
+microwave magnetic fields B1 strong enough to saturate electron spins,
+microwave resonators are generally used to achieve a sufficient B1, at the
+expense of restricting the sample size. Higher fields improve NMR sensitivity
+and resolution. However, resonators at 9 T for example can only hold
+nano-liters (nL). Larger volumes are possible by avoiding resonators, but the
+higher power needed to reach B1 is likely to evaporate the sample. Here, we
+demonstrate a breakthrough in liquid state DNP at 9 T, boosting the sample size
+to the microliter range. We could use high-power (70 W) microwaves thanks to a
+planar probe designed to alleviate dielectric heating. We enhanced the 1H NMR
+signal intensity of 2 uL of liquid water by a factor of 14, while maintaining
+the water temperature below 40 degree Celsius.",1708.02800v1
+2017-11-24,Faraday rotation signatures of fluctuation dynamos in young galaxies,"Observations of Faraday rotation through high-redshift galaxies have revealed
+that they host coherent magnetic fields that are of comparable strengths to
+those observed in nearby galaxies. These fields could be generated by
+fluctuation dynamos. We use idealized numerical simulations of such dynamos in
+forced compressible turbulence up to rms Mach number of 2.4 to probe the
+resulting rotation measure (RM) and the degree of coherence of the magnetic
+field. We obtain rms values of RM at dynamo saturation of the order of 45 - 55
+per cent of the value expected in a model where fields are assumed to be
+coherent on the forcing scale of turbulence. We show that the dominant
+contribution to the RM in subsonic and transonic cases comes from the general
+sea of volume filling fields, rather than from the rarer structures. However,
+in the supersonic case, strong field regions as well as moderately overdense
+regions contribute significantly. Our results can account for the observed RMs
+in young galaxies.",1711.08865v2
+2018-01-10,Skyrmion states in thin confined polygonal nanostructures,"Recent studies have demonstrated that skyrmionic states can be the ground
+state in thin-film FeGe disk nanostructures in the absence of a stabilising
+applied magnetic field. In this work, we advance this understanding by
+investigating to what extent this stabilisation of skyrmionic structures
+through confinement exists in geometries that do not match the cylindrical
+symmetry of the skyrmion -- such as as squares and triangles. Using simulation,
+we show that skyrmionic states can form the ground state for a range of system
+sizes in both triangular and square-shaped FeGe nanostructures of
+$10\,\text{nm}$ thickness in the absence of an applied field. We further
+provide data to assist in the experimental verification of our prediction; to
+imitate an experiment where the system is saturated with a strong applied field
+before the field is removed, we compute the time evolution and show the final
+equilibrium configuration of magnetization fields, starting from a uniform
+alignment.",1801.03275v1
+2018-01-16,Conformal Mapping Approach to Dipole Shim Design,"Passive shims are often used to reduce the size and cost of room-temperature
+magnetic dipoles. In this paper we revisit an analytic approach to the problem
+of optimum shim design, and we extend it by taking into consideration the
+effect of magnetic saturation. We derive an abacus curve to determine optimum
+shim dimensions as a function of the desired dipole nominal field. We show
+that, for nominal fields below 1.2 T, a pole with such shims can be made at
+least one half gap height narrower than a pole without. We discuss the range of
+validity of this approach and verify its predictions using 2 and 3-dimensional
+finite-element calculations.",1801.05470v2
+2018-01-24,Quantization of magnetoelectric fields,"The effect of quantum coherence involving macroscopic degree of freedom, and
+occurring in systems far larger than individual atoms are one of the topical
+fields in modern physics. Because of material dispersion, a phenomenological
+approach to macroscopic quantum electrodynamics, where no canonical formulation
+is attempted, is used. The problem becomes more complicated when geometrical
+forms of a material structure have to be taken into consideration. Magnetic
+dipolar mode (MDM) oscillations in a magnetically saturated quasi 2D ferrite
+disk are macroscopically quantized states. In this ferrimagnetic structure,
+long range dipole dipole correlation in positions of electron spins can be
+treated in terms of collective excitations of a system as a whole. The near
+fields in the proximity of a MDM ferrite disk have space and time symmetry
+breakings. Such MDM-originated fields, called magnetoelectric (ME) fields,carry
+both spin and orbital angular momentums. By virtue of unique topology, ME
+fields are different from free space electromagnetic (EM) fields. The ME fields
+are quantum fluctuations in vacuum. We call these quantized states ME photons.
+There are not virtual EM photons. We show that energy, spin and orbital angular
+momenta of MDM oscillations constitute the key physical quantities that
+characterize the ME field configurations. We show that vacuum can induce a
+Casimir torque between a MDM ferrite disk, metal walls, and dielectric samples.",1801.08042v1
+2018-04-23,Magnetic field-induced resistivity upturn and exceptional magneto-resistance in Weyl semimetal TaSb2,"We study magneto-transport properties in single crystals of TaSb_2, which is
+a recently discovered topological semimetal. In the presence of magnetic field,
+the electrical resistivity shows onset of insulating behaviour followed by
+plateau at low temperature. Such resistivity plateau is generally assigned to
+topological surface states. TaSb2 exhibits extremely high magneto-resistance
+with non-saturating field dependence. We find that aspects of extremely large
+magneto resistance and resistivity plateau are well accounted by classical
+Kohler scaling. Unambiguous evidence for anomalous Chiral transport is provided
+with observation of negative longitudinal magneto-resistance. Shubnikov-de Haas
+oscillations reveal two dominating frequencies, 201 T and 455 T. These aspects
+categorize TaSb2 as a Type-II Weyl semimetal. At low temperature, the field
+dependence of Hall resistivity shows non-linear behaviour that indicates the
+presence of two types of charge carriers in consonance with reported electronic
+band structure. Analysis of Hall resistivity imply very high electron
+mobilities.",1804.08434v1
+2018-05-14,Homogeneous and heterogeneous nucleation of skyrmions in thin layers of cubic helimagnets,"Formation of isolated chiral skyrmions by homogeneous and heterogeneous
+nucleation has been studied in thin layers of cubic helimagnets via elongation
+of torons and chiral bobbers, correspondingly. Both torons and bobbers are
+localized in three dimensions, contain singularities, and according to the
+theoretical analysis within the standard phenomenological models can exist as
+metastable states in saturated and modulated phases of noncentrosymmetric
+ferromagnets. Their elongation into the defect-free skyrmion filament is
+facilitated by small anisotropic contributions making skyrmion cores negative
+with respect to the surrounding parental state. We show that isolated magnetic
+torons pose the same problem of compatibility with a surrounding phase as the
+torons in confinement-frustrated chiral nematics [I. Smalyukh et al., Nature
+Mater 9, 139-145 (2010)]. We underline the distinct features of magnetic and
+liquid-crystals torons and calculate phase diagrams indicating their stability
+regions.",1805.04990v1
+2018-06-27,Photocatalytic activity enhancement by addition of lanthanum into the BiFeO3 structure and the effect of synthesis method,"In this paper, the photocatalytic activity of multiferroics BiFeO3 (BFO) and
+Bi0.8La0.2FeO3 (BLFO) nanocrystals with two different morphologies which were
+synthesized by two different sol-gel (SG) and hydrothermal (HT) methods have
+been studied. All the obtained samples were characterized using X-ray
+diffractometer, Fourier transform infrared spectroscopy, transmission electron
+microscopy, UV-vis spectroscopy and vibrating sample magnetometer. Differential
+thermal analysis (DTA) measurements were probed ferroelectric- paraelectric
+first-order phase transition (TC) for all samples. Addition of lanthanum
+decreases the electric phase transition. For photocatalyst application of
+bismuth ferrite, adsorption potential of nanoparticles for methylene blue (MB)
+organic dye was evaluated. The doping of La in the BFO structure enhanced the
+photocatalytic activity and about 71% degradation of MB dye was obtained under
+visible irradiation. The magnetic and ferroelectric properties of BLFO
+nanoparticles improve compared to the undoped BiFeO3 nanoparticles. The
+non-saturation at high applied magnetic field for as-prepared samples by HT is
+related to the size and shape of products. This work not only presents an
+effect of lanthanum substitution into the bismuth ferrite structure on the
+physical properties of BFO, but also compares the synthesis method and its
+influence on the photocatalytic activity and multiferroics properties of all
+nanopowders.",1807.03127v1
+2018-07-31,New room-temperature ferromagnet: B-added Pd0.75Mn0.25 alloy,"Mn-based room-temperature ferromagnets attract considerable attention due to
+their high ordered Mn moment. We have found that a Pd0.75Mn0.25 alloy with
+added B (Pd0.75Mn0.25Bx) shows room-temperature soft ferromagnetism, whereas
+the parent Pd0.75Mn0.25 alloy is a spin-glass system. The saturated Mn moment
+at room temperature systematically increases to 2.68\muB/Mn as x increases to
+0.125. The maximum Curie temperature of 390 K is also realized at an x of
+0.125. The experimental results suggest a tunable soft ferromagnetism, which is
+governed only by the boron concentration. Our results will pave the way in
+chemical control of room-temperature bulk ferromagnetism in Mn compounds based
+on the addition of an atom with a small atomic radius.",1807.11640v1
+2018-08-07,"Development of Ferromagnetic Fluctuations in Heavily Overdoped (Bi,Pb)_2_Sr_2_CuO_6+delta_ Copper Oxides","We demonstrate the presence of ferromagnetic (FM) fluctuations in the
+superconducting and non-superconducting heavily overdoped regimes of
+high-temperature superconducting copper oxides, using
+(Bi,Pb)_2_Sr_2_CuO_6+delta_ (Bi-2201) single crystals. Magnetization curves
+exhibit a tendency to be saturated in high magnetic fields at low temperatures
+in the heavily overdoped crystals, which is probably a precursor phenomenon of
+a FM transition at a lower temperature. Muon spin relaxation detects the
+enhancement of spin fluctuations at high temperatures below 200 K.
+Correspondingly, the ab-plane resistivity follows a 4/3 power law in a wide
+temperature range, which is characteristic of metals with two-dimensional FM
+fluctuations due to itinerant electrons. As the Wilson ratio evidences the
+enhancement of spin fluctuations with hole doping in the heavily overdoped
+regime, it is concluded that two-dimensional FM fluctuations reside in the
+heavily overdoped Bi-2201 cuprates, which is probably related to the decrease
+in the superconducting transition temperature in the heavily overdoped
+cuprates.",1808.02317v1
+2018-08-13,Nonlinear firehose relaxation and constant-B field fluctuations,"The nonlinear evolution of Alfv\'enic fluctuations in the firehose unstable
+regime is investigated numerically and theoretically for an anisotropic plasma
+described by the one-fluid double adiabatic equations. We revisit the
+traditional theory of the instability and examine the nonlinear saturation
+mechanism, showing that it corresponds to evolution towards states that
+minimize an appropriate energy functional. We demonstrate that such states
+correspond to broadband magnetic and velocity field fluctuations with an
+overall constant magnitude of the magnetic field. These nonlinear states
+provide a basin of attraction for the long-term nonlinear evolution of the
+instability, a self-organization process that may play a role in maintaining
+the constant-$B$ Alfv\'enic states seen in the solar wind in the high-$\beta$
+regime.",1808.04453v2
+2018-08-20,Electronic transport properties of Co cluster-decorated graphene,"Interactions of magnetic elements with graphene may lead to various
+electronic states that have potential applications. We report an in-situ
+experiment in which the quantum transport properties of graphene are measured
+with increasing cobalt coverage in continuous ultra-high vacuum environment.
+The results show that e-beam deposited cobalt forms clusters on the surface of
+graphene, even at low sample temperatures. Scattering of charge carriers by the
+absorbed cobalt clusters results in the disappearance of the Shubnikov-de Haas
+(SdH) oscillations and the appearance of negative magnetoresistance (MR) which
+shows no sign of saturation up to an applied magnetic field of 9 T. We propose
+that these observations could originate from quantum interference driven by
+cobalt disorder and can be explained by the weak localization theory.",1808.06331v1
+2018-12-12,Emergent prethermalization signatures in out-of-time ordered correlations,"How a many-body quantum system thermalizes --or fails to do so-- under its
+own interaction is a fundamental yet elusive concept. Here we demonstrate
+nuclear magnetic resonance observation of the emergence of prethermalization by
+measuring out-of-time ordered correlations. We exploit Hamiltonian engineering
+techniques to tune the strength of spin-spin interactions and of a transverse
+magnetic field in a spin chain system, as well as to invert the Hamiltonian
+sign to reveal out-of-time ordered correlations. At large fields, we observe an
+emergent conserved quantity due to prethermalization, which can be revealed by
+an early saturation of correlations. Our experiment not only demonstrates a new
+protocol to measure out-of-time ordered correlations, but also provides new
+insights in the study of quantum thermodynamics.",1812.04776v1
+2018-12-30,Dynamics of Magnetoelectric Reversal of Antiferromagnetic Domain,"When electric and magnetic fields are applied together on a magnetoelectric
+antiferromagnet, the domain state is subject to reversal. Although the initial
+and final conditions are saturated single-domain states, the process of
+reversal may decompose into local multi-domain switching events. In thin films
+of Cr2O3, the magnetoelectric coercivity and the switching speed found from
+experiments are considerably lower than expected from magnetic anisotropy,
+similar to Brown's paradox in ferromagnetic materials. Multi-domain effects
+originate because antiferromagnetic domain walls are metastably pinned by
+lattice defects, not due to reduction of magnetostatic energy, which is
+negligible. This paper theoretically analyzes domain reversal in thin-film
+magnetoelectric antiferromagnets in the form of nucleation, domain wall
+propagation, and coherent rotation. The timescales of reversal mechanisms are
+modeled as a function of applied magnetoelectric pressure. The theory is
+assessed with reference to latest experimental works on magnetoelectric
+switching of thin-film Cr2O3: domain wall propagation is found to be dominant
+and responsible for switching in the experiments. The results bear implications
+in the energy-delay performance of ME memory devices utilizing
+antiferromagnetic insulators, which are prospective for nonvolatile technology.",1812.11579v3
+2019-02-01,Non-linear modeling of the threshold between ELM mitigation and ELM suppression by Resonant Magnetic Perturbations in ASDEX Upgrade,"The interaction between Edge Localized Modes (ELMs) and Resonant Magnetic
+Perturbations (RMPs) is modeled with the magnetohydrodynamic code JOREK using
+experimental parameters from ASDEX Upgrade discharges. The ELM mitigation or
+suppression is optimal when the amplification of both tearing and peeling-kink
+responses result in a better RMP penetration. The ELM mitigation or suppression
+is not only due to the reduction of the pressure gradient, but predominantly
+arises from the toroidal coupling between the ELMs and the RMP-induced mode at
+the plasma edge, forcing the edge modes to saturate at a low level. The
+bifurcation from ELM mitigation to ELM suppression is observed when the RMP
+amplitude is increased. ELM mitigation is characterized by rotating modes at
+the edge, while the mode locking to RMPs is induced by the resonant braking of
+the electron perpendicular flow in the ELM suppression regime.",1902.00398v2
+2019-02-27,From kagome strip to kagome lattice: Realizations of frustrated S=1/2 antiferromagnets in Ti(III) fluorides,"We investigate the connection between highly frustrated kagome based
+Hamiltonians and a recently synthesized family of materials containing Ti3+
+S=1/2 ions. Employing a combination of all electron density functional theory
+and numerical diagonalization techniques, we establish the Heisenberg
+Hamiltonians for the distorted kagome antiferromagnets Rb2NaTi3F12, Cs2NaTi3F12
+and Cs2KTi3F12. We determine magnetization curves in excellent agreement with
+experimental observations. Our calculations successfully clarify the
+relationship between the experimental observations and the
+magnetization-plateau behavior at 1/3 height of the saturation and predict
+characteristic behaviors under fields that are higher than the experimentally
+measured region. We demonstrate that the studied Ti(III) family of materials
+interpolates between kagome strip and kagome lattice.",1902.10309v1
+2019-03-20,Electronic Structure Calculations of CeRh$_{3}$B$_{2}$,"The electronic structure of the ferromagnetic material CeRh$_{3}$B$_{2}$ is
+studied by means of first-principles calculations with an emphasis on the
+treatment of localized $4f$ states around Ce. Via the construction of an
+effective spin model from electronic structure calculations, we estimated the
+Curie temperature $T_{\rm C}$ of CeRh$_{3}$B$_{2}$ and found a specific
+configuration of the electronic structure which explains the exceptionally high
+measured value of $T_{\rm C} \sim 120$ K as well as the small saturation
+magnetization and the topology of the Fermi surface. Present advance in the
+understanding of the subtle nature of the $4f$-electron state in
+CeRh$_{3}$B$_{2}$ that brings about the exceptionally high $T_{\rm C}$ should
+be also of technological relevance to exploit the utility of Ce in rare-earth
+permanent magnets.",1903.08480v1
+2019-03-27,Nonlinear Evolution of Ion Kinetic Instabilities in the Solar Wind,"In-situ observations of the solar wind (SW) plasma from 0.29 to 1AU show that
+the protons and alpha particles are often non-Maxwellian, with evidence of
+kinetic instabilities, temperature anisotropies, differential ion streaming,
+and associated magnetic fluctuations spectra. The kinetic instabilities in the
+SW multi-ion plasma can lead to preferential heating of alpha particles and the
+dissipation of magnetic fluctuation energy, affecting the kinetic and global
+properties of the SW. Using for the first time a three-dimensional hybrid
+model, where ions are modeled as particle using the Particle-In-Cell (PIC)
+method and electrons are treated as fluid, we study the onset, nonlinear
+evolution and dissipation of ion kinetic instabilities. The
+Alfven/ion-cyclotron, and the ion drift instabilities are modeled in the region
+close to the Sun (~10R_s). Solar wind expansion is incorporated in the model.
+The model produces self-consistent non-Maxwellian velocity distribution
+functions (VDFs) of unstable ion populations, the associated temperature
+anisotropies, and wave spectra for several typical SW instability cases in the
+nonlinear growth and saturation stage of the instabilities. The 3D hybrid
+modeling of the multi-ion SW plasma could be used to study the SW acceleration
+region close to the Sun that will be explored by the Parker Solar Probe
+mission.",1903.11343v1
+2019-04-10,On the properties of a newborn magnetar powering the X-ray transient CDF-S XT2,"Very recently \citet{XueYQ2019} reported an important detection of the X-ray
+transient, CDF-S XT2, whose light curve is analogous to X-ray plateau features
+of gamma-ray burst afterglows. They suggested that this transient is powered by
+a remnant stable magnetar from a binary neutron star merger since several
+pieces of evidence (host galaxy, location, and event rate) all point toward
+such an assumption. In this paper, we revisit this scenario and confirm that
+this X-ray emission can be well explained by the internal gradual magnetic
+dissipation process in an ultra-relativistic wind of the newborn magnetar. We
+show that both the light curve and spectral evolution of CDF-S XT2 can be well
+fitted by such a model. Furthermore, we can probe some key properties of the
+central magnetar, such as its initial spin period, surface magnetic field
+strength and wind saturation Lorentz factor.",1904.05480v2
+2019-04-11,Study of soft/hard bimagnetic CoFe2/CoFe2O4 nanocomposite,"We report an experimental study of the bimagnetic nanocomposites
+CoFe2/CoFe2O4.The precursor material, CoFe2O4 was prepared using the
+conventional stoichiometric combustion method. The nanocomposite CoFe2/CoFe2O4
+was obtained by total reduction of CoFe2O4 using a thermal treatment at 350oC
+in H2 atmospheres following a partial oxidation in O2 atmospheres at 380oC
+during 120; 30; 15, 10, and 5 min. The X-ray diffraction and Mossbauer
+spectroscopy confirmed the formation the material CoFe2/CoFe2O4 The magnetic
+hysteresis with different saturation magnetization confirms the formation of
+the CoFe2/CoFe2O4 with different content of CoFe2O4. The high energy milling to
+the precursor material increase the coercivity from 1.0 to 3.3 kOe, however the
+same effect was not observed to the CoFe2/CoFe2O4 material.",1904.05984v1
+2019-04-23,Tailored tunnel magnetoresistance response in three ultrathin chromium trihalides,"Materials that demonstrate large magnetoresistance have attracted significant
+interest for many decades. Recently, extremely large tunnel magnetoresistance
+(TMR) has been reported by several groups across ultrathin CrI$_3$ by
+exploiting the weak antiferromagnetic coupling between adjacent layers. Here,
+we report a comparative study of TMR in all three chromium trihalides (CrX$_3$,
+X= Cl, Br, or I) in the two-dimensional limit. As the materials exhibit
+different transition temperatures and interlayer magnetic ordering in the
+ground state, tunneling measurements allow for an easy determination of the
+field-temperature phase diagram for the three systems. By changing sample
+thickness and biasing conditions, we then demonstrate how to maximize and
+further tailor the TMR response at different temperatures for each material. In
+particular, near the magnetic transition temperature, TMR is non-saturating up
+to the highest fields measured for all three compounds owing to the large,
+field-induced exchange coupling.",1904.10476v2
+2019-05-04,Identification and time-resolved study of YIG spin wave modes in a MW cavity in strong coupling regime,"Recently, the hybridization of microwave-frequency cavity modes with
+collective spin excitations attracted large interest for the implementation of
+quantum computation protocols, which exploit the transfer of information among
+these two physical systems. Here, we investigate the interaction among the
+magnetization precession modes of a small YIG sphere and the MW electromagnetic
+modes, resonating in a tridimensional aluminum cavity. In the strong coupling
+regime, anti-crossing features were observed in correspondence of various
+magnetostatic modes, which were excited in a magnetically saturated sample.
+Time-resolved studies show evidence of Rabi oscillations, demonstrating
+coherent exchange of energy among photons and magnons modes. To facilitate the
+analysis of the standing spin-wave patterns, we propose here a new procedure,
+based on the introduction of a novel functional variable. The resulting easier
+identification of magnetostatic modes can be exploited to investigate, control
+and compare many-levels hybrid systems in cavity- and opto-magnonics research.",1905.01522v2
+2019-07-03,"Rotational dynamics of planetary cores: instabilities driven by precession, libration and tides","In this chapter, we explore how gravitational interactions drive turbulent
+flows inside planetary cores and provide an interesting alternative to
+convection to explain dynamo action and magnetic fields around terrestrial
+bodies. In the first section, we introduce tidal interactions and their effects
+on the shape and rotation of astrophysical bodies. A method is given to derive
+the primary response of liquid interiors to these tidally-driven perturbations.
+In the second section, we detail the stability of this primary response and
+demonstrate that it is able to drive resonance of inertial waves. As the
+instability mechanism is introduced, we draw an analogy with the parametric
+amplification of a pendulum whose length is periodically varied. Lastly, we
+present recent results regarding this instability, in particular its non-linear
+saturation and its ability to drive dynamo action. We present how it has proved
+helpful to explain the magnetic field of the early Moon.",1907.02001v1
+2019-07-17,Multiple phase transitions and high-field quadrupolar order in a model for $β$-TeVO$_4$,"Motivated by the complex behavior of the frustrated magnet $\beta$-TeVO$_4$,
+we study an anisotropic Heisenberg model for coupled spin-$1/2$ zigzag chains.
+Using cluster mean field approach to capture quantum correlations we find, upon
+reducing temperature in the absence of applied field, (i) a partially ordered
+state, (ii) a collinear antiferromagnetic phase, and (iii) an elliptical spiral
+state characterized by finite vector chirality. For finite fields, we find
+metamagnetic response close to saturation magnetization. We show via explicit
+calculations that the quadrupolar order parameter is finite in the metamagnetic
+regime. The exchange parameters reported in the ab-initio study of
+$\beta$-TeVO$_4$ are used in our study. We compare our results with those
+reported in recent experiments on $\beta$-TeVO$_4$ and highlight similarities
+as well as differences between experimental results and our cluster mean field
+calculations.",1907.07354v2
+2019-07-31,Large spin Hall magnetoresistance in antiferromagnetic α-Fe2O3/Pt heterostructures,"We investigate the spin Hall magnetoresistance (SMR) at room temperature in
+thin film heterostructures of antiferromagnetic, insulating, (0001)-oriented
+alpha-Fe2O3 (hematite) and Pt. We measure their longitudinal and transverse
+resistivities while rotating an applied magnetic field of up to 17T in three
+orthogonal planes. For out-of-plane magnetotransport measurements, we find
+indications for a multidomain antiferromagnetic configuration whenever the
+field is aligned along the film normal. For in-plane field rotations, we
+clearly observe a sinusoidal resistivity oscillation characteristic for the SMR
+due to a coherent rotation of the Neel vector. The maximum SMR amplitude of
+0.25% is, surprisingly, twice as high as for prototypical ferrimagnetic
+Y3Fe5O12/Pt heterostructures. The SMR effect saturates at much smaller magnetic
+fields than in comparable antiferromagnets, making the alpha-Fe2O3/Pt system
+particularly interesting for room-temperature antiferromagnetic spintronic
+applications.",1907.13393v4
+2019-08-16,Emergent Snake Magnetic Domains in Canted Kagome Ice,"We study the two-dimensional kagome-ice model derived from a pyrochlore
+lattice with second- and third-neighbor interactions. The canted moments align
+along the local $\langle 111 \rangle$ axes of the pyrochlore and respond to
+both in-plane and out-of-plane external fields. We find that the combination of
+further-neighbor interactions together with the external fields introduces a
+rich phase diagram with different spin textures. Close to the phase boundaries,
+metastable $\textit{""snake""}$ domains emerge with extremely long relaxation
+time. Our kinetic Monte Carlo analysis of the magnetic-field quench process
+from saturated state shows unusually slow dynamics. Despite that the interior
+spins are almost frozen in snake domains, the spins on the edge are free to
+fluctuate locally, leading to frequent creation and annihilation of
+monopole-anti-monopole bound states. Once the domains are formed, these
+excitations are localized and can hardly propagate due to the energy barrier of
+snakes. The emergence of such snake domains may shed light on the experimental
+observation of dipolar spin ice under tilted fields, and provide a new strategy
+to manipulate both spin and charge textures in artificial spin ice.",1908.05872v1
+2019-08-22,Phase diagram and quantum criticality of Heisenberg spin chains with Ising-like interchain couplings -- Implication to YbAlO$_3$,"Motivated by recent progress on field-induced phase transitions in
+quasi-one-dimensional quantum antiferromagnets, we study the phase diagram of
+$S=1/2$ antiferromagnetic Heisenberg chains with Ising anisotropic interchain
+couplings under a longitudinal magnetic field via large-scale quantum Monte
+Carlo simulations. The interchain interactions is shown to enhance longitudinal
+spin correlations to stabilize an incommensurate longitudinal spin density wave
+order at low temperatures. With increasing field the ground state changes to a
+canted antiferromagnetic order until the magnetization fully saturates above a
+quantum critical point controlled by the $(3+2)$D XY universality. Increasing
+temperature in the quantum critical regime the system experiences a fascinating
+dimension crossover to a universal Tomonaga-Luttinger liquid. The calculated
+NMR relaxation rate $1/T_1$ indicates this Luttinger liquid behavior survives a
+broad field and temperature regime. Our results determine the global phase
+diagram and quantitative features of quantum criticality of a general model for
+quasi-one-dimensional spin chain compounds, and thus lay down a concrete ground
+to the study on these materials.",1908.08467v1
+2019-08-24,Emergent critical phenomenon in spin-1/2 ferromagnetic-leg ladders: Quasi-one-dimensional Bose--Einstein condensate,"We examine the magnetic-field-induced criticality of phase boundary near
+saturation field $H_{\mathrm{c}}$ in the spin-1/2 ferromagnetic (FM)-leg ladder
+3-Cl-4-F-V [=3-(3-chloro-4-fluorophenyl)-1,5-diphenylverdazyl], the predominant
+interactions of which arise from FM chains (strong-leg type). Critical
+temperatures were precisely determined through dc magnetization, specific heat,
+and magnetocaloric effect measurements. The criticality of 3-Cl-4-F-V is
+characterized by a linear phase boundary with respect to $H_{\mathrm{c}}-H$
+near $H\,=\,H_{\mathrm{c}}$. This behavior is similar to that of another
+strong-leg-type FM-leg ladder. The universal critical behavior in these
+strong-leg-type FM-leg ladders is expected to demonstrate the theoretically
+predicted quasi-one-dimensional Bose--Einstein condensation.",1908.09076v1
+2019-09-06,The interplay of large two-magnon ferromagnetic resonance linewidths and low Gilbert damping in Heusler thin films,"We report on broadband ferromagnetic resonance linewidth measurements
+performed on epitaxial Heusler thin films. A large and anisotropic two-magnon
+scattering linewidth broadening is observed for measurements with the
+magnetization lying in the film plane, while linewidth measurements with the
+magnetization saturated perpendicular to the sample plane reveal low Gilbert
+damping constants of $(1.5\pm0.1)\times 10^{-3}$, $(1.8\pm0.2)\times 10^{-3}$,
+and $<8\times 10^{-4}$ for Co$_2$MnSi/MgO, Co$_2$MnAl/MgO, and Co$_2$FeAl/MgO,
+respectively. The in-plane measurements are fit to a model combining Gilbert
+and two-magnon scattering contributions to the linewidth, revealing a
+characteristic disorder lengthscale of 10-100 nm.",1909.02738v2
+2019-10-17,Magneto-dielectric Effect in Relaxor Dipolar Glassy Tb2CoMnO6 Film,"We report magneto-dielectric properties of partially B-site ordered
+monoclinic Tb2CoMnO6 double perovskite thin film epitaxially grown by
+metalorganic aerosol deposition technique. Transmission electron microscopy and
+electron energy loss spectroscopy mapping shows the presence and distribution
+of both Co2+ and Co3+ ions in the film, evidencing a partial B-site disorder,
+which was further confirmed by the observation of reduced saturation
+magnetization at low temperatures. The ferromagnetic Curie temperature, TC=110
+K, is slightly higher as compared to the bulk value (100 K) probably due to an
+in plane tensile strain. Remarkably, a short range ordering of spins at T*~190
+K>>TC was established and assigned to the B-site disorder in the film. Two
+different dielectric relaxation peaks have been observed; they merge at the
+same temperature T* of short range spin correlations. Moreover, an unexpected
+high temperature dipolar relaxor-glass-like transition at T~T* was observed, at
+which a coupling to short range magnetic correlations results in a 4%
+magneto-dielectric coupling.",1910.07991v1
+2019-11-06,High spin mixing conductance and spin interface transparency at $Co_2Fe_{0.4}Mn_{0.6}Si$ Heusler alloy and Pt interface,"Ferromagnetic materials exhibiting low magnetic damping ($\alpha$) and
+moderately high saturation magnetization are required from the viewpoints of
+generation, transmission and detection of spin wave. Since spin-to-charge
+conversion efficiency is another important parameter, high spin mixing
+conductance ($g_{r}^{\uparrow \downarrow}$) is the key for efficient
+spin-to-charge conversion. Full Heusler alloys e.g. $Co_2Fe_{0.4}Mn_{0.6}Si$
+(CFMS), which are predicted to be 100$\%$ spin polarized, possess low $\alpha$.
+However, the $g_{r}^{\uparrow \downarrow}$ at the interface between CFMS and a
+paramagnet has not fully been understood. Here, we report the investigations of
+spin pumping and inverse spin Hall effect in $CFMS/Pt$ bilayers. Damping
+analysis indicates the presence of significant spin pumping at the interface of
+CFMS and Pt, which is also confirmed by the detection of inverse spin Hall
+voltage. We show that in CFMS/Pt the $g_{r}^{\uparrow \downarrow}$
+(1.77$\times$10$^{20}$m$^{-2}$) and interface transparency (84$\%$) are higher
+compared to values reported for other ferromagnet/heavy metal systems.",1911.02230v1
+2019-12-19,Gyrokinetic investigation of Alfvén instabilities in the presence of turbulence,"The global and electromagnetic gyrokinetic particle-in-cell code ORB5 is
+employed to investigate the self-consistent interactions between Alfv\'en modes
+(AM) and ion temperature gradient (ITG) turbulence in a magnetically confined
+plasma. Here, an axisymmetric magnetic equilibrium with reversed shear and
+large aspect ratio is considered. An AM with toroidal mode number n=5 is driven
+unstable by introducing a population of suprathermal ions. Once the AM
+saturates in the presence of the fully developed turbulence, the ion heat flux
+is dominated by the AM and its main harmonics. ITG-induced transport is found
+to also be enhanced in the presence of the unstable AM.",1912.09409v1
+2020-01-23,In-vivo Magnetic Resonance Imaging of GABA and Glutamate,"Chemical Exchange Saturation Transfer (CEST) Magnetic Resonance Imaging (MRI)
+is a molecular imaging methodology capable of mapping brain metabolites with
+relatively high spatial resolution. Specificity is the main goal of such
+experiments; yet CEST is confounded by spectral overlap between different
+molecular species. Here, we overcome this major limitation using a general
+framework termed overlap-resolved CEST (orCEST) - a kind of spectrally-edited
+experiment restoring specificity. First, we present evidence revealing that
+CEST experiments targeting the central nervous system's primary excitatory
+neurotransmitter, Glutamate (GluCEST) - is significantly contaminated by
+gamma-aminobutyric acid (GABA) - the primary inhibitory neurotransmitter in the
+CNS. Then, we harness the novel orCEST methodology to separate Glutamate and -
+for the first time - GABA signals, thus delivering the desired specificity.
+In-vivo orCEST experiments resolved the rat brain's primary neurotransmitters
+and revealed changes in Glutamate and GABA levels upon water deprivation in
+thirst-related areas. orCEST's features bode well for many applications in
+neuroscience and biomedicine.",2001.08515v1
+2020-01-30,An anomalous refraction of spin waves as a way to guide signals in curved magnonic multimode waveguides,"We present a method for efficient spin wave guiding within the magnonic
+nanostructures. Our technique is based on the anomalous refraction in the
+metamaterial flat slab. The gradual change of the material parameters
+(saturation magnetization or magnetic anisotropy) across the slab allows
+tilting the wavefronts of the transmitted spin waves and controlling the
+refraction. Numerical studies of the spin wave refraction are preceded by the
+analytical calculations of the phase shift acquired by the spin wave due to the
+change of material parameters in a confined area. We demonstrate that our
+findings can be used to guide the spin waves smoothly in curved waveguides,
+even through sharp bends, without reflection and scattering between different
+waveguide's modes, preserving the phase -- the quantity essential for wave
+computing.",2001.11356v1
+2020-02-26,Singlet state encoded magnetic resonance (SISTEM) spectroscopy,"Magnetic resonance spectroscopy (MRS) allows the analysis of biochemical
+processes non invasively and in vivo. Still, its application in clinical
+diagnostics is rare. Routine MRS is limited to spatial, chemical and temporal
+resolutions of cubic centimetres, mM and minutes. In fact, the signal of many
+metabolites is strong enough for detection, but the resonances significantly
+overlap, exacerbating identification and quantification. In addition, the
+signals of water and lipids are much stronger and dominate the entire spectrum.
+To suppress the background and isolate selected signals, usually, relaxation
+times, J-coupling and chemical shifts are used. Here, we propose methods to
+isolate the signals of selected molecular groups within endogenous metabolites
+by using long-lived spin states (LLS). We exemplify the method by preparing the
+LLSs of coupled protons in the endogenous molecules N-acetyl-L-aspartic acid
+(NAA). First, we store polarization in long-lived, double spin states and then
+apply saturation pulses and double quantum filters to suppress background
+signals. We show that LLS can be used to selectively prepare and measure the
+signals of chosen metabolites or drugs in the presence of water, inhomogeneous
+field and highly concentrated fatty solutions. The pH measurement presented
+here is one of the possible applications.",2002.11350v1
+2020-03-06,Epitaxial growth and orientation-dependent anomalous Hall effect of noncollinear antiferromagnetic Mn$_3$Ni$_{0.35}$Cu$_{0.65}$N films,"We report the growth of noncollinear antiferromagnetic (AFM)
+Mn$_3$Ni$_{0.35}$Cu$_{0.65}$N films and the orientation-dependent anomalous
+Hall effect (AHE) of (001) and (111) films due to nonzero Berry curvature. We
+found that post-annealing at 500$^\circ$C can significantly improve the AHE
+signals, though using the appropriate post-annealing conditions is important.
+The AHE and magnetization loops show sharp flipping at the coercive field in
+(111) films, while (001) films are hard to saturate by a magnetic field. The
+anomalous Hall conductivity of (111) films is an order of magnitude larger than
+that of (001) films. The present results provide not only a better
+understanding of the AHE in Mn$_3X$N systems but also further opportunities to
+study the unique phenomena related to noncollinear AFM.",2003.03031v1
+2020-03-09,The self-similar structure of advection-dominated discs with outflow and radial viscosity,"Observational evidence and theoretical arguments postulate that outflows may
+play a significant role in the advection-dominated accretion discs (ADAFs).
+While the azimuthal viscosity is the main focus of most previous studies in
+this context, recent studies indicated that disc structure can also be affected
+by the radial viscosity. In this work, we incorporate these physical
+ingredients and the toroidal component of the magnetic field to explore their
+roles in the steady-state structure of ADAFs. We thereby present a set of
+similarity solutions where outflows contribute to the mass loss, angular
+momentum removal, and the energy extraction. Our solutions indicate that the
+radial viscosity causes the disc to rotate with a slower rate, whereas the
+radial gas velocity increases. For strong winds, the infall velocity may be of
+order the Keplerian speed if the radial viscosity is considered and the
+saturated conduction parameter is high enough. We show that the strength of
+magnetic field and of wind can affect the effectiveness of radial viscosity.",2003.04752v1
+2020-03-14,Magnetar formation through a convective dynamo in protoneutron stars,"The release of spin-down energy by a magnetar is a promising scenario to
+power several classes of extreme explosive transients. However, it lacks a firm
+basis because magnetar formation still represents a theoretical challenge.
+Using the first three-dimensional simulations of a convective dynamo based on a
+protoneutron star interior model, we demonstrate that the required dipolar
+magnetic field can be consistently generated for sufficiently fast rotation
+rates. The dynamo instability saturates in the magnetostrophic regime with the
+magnetic energy exceeding the kinetic energy by a factor of up to 10. Our
+results are compatible with the observational constraints on galactic magnetar
+field strength and provide strong theoretical support for millisecond
+protomagnetar models of gamma-ray burst and superluminous supernova central
+engines.",2003.06662v1
+2020-03-18,A firehose-like aperiodic instability of the counter-beaming electron plasmas,"Depending on the physical conditions involved the beam plasma systems may
+reveal new unstable regimes triggered by the wave instabilities of different
+nature. We show through linear theory and numerical simulations the existence
+of an aperiodic electromagnetic instability which solely develops and control
+the stability of two symmetric plasma populations counter-moving along the
+regular magnetic field with a relative drift, $v_d$, small enough to not exceed
+the particle thermal speed, $\alpha_e$. Emerging at highly oblique angles this
+mode resembles properties of the aperiodic firehose instability driven by
+temperature anisotropy. The high growth rates achieved with increasing the
+relative drift or/and decreasing the plasma beta parameter lead to significant
+saturation levels of the fluctuating magnetic field power, which explain the
+relative fast relaxation of electrons. For $v_d>\alpha_e$ this instability can
+coexist with the electrostatic two-stream instability, dominating the long-term
+dynamics of the plasma as soon as $v_d$ has relaxed to values smaller than the
+thermal speed.",2003.08245v1
+2020-05-05,Study of single crystalline SrAgSb and SrAuSb semimetals,"Given renewed interest in the electronic properties of semimetallic compounds
+with varying degrees of spin orbit coupling we have grown single crystals of
+SrAgSb and SrAuSb, measured their temperature and field dependent electrical
+resistivity and magnetization and performed density functional theory (DFT)
+band structure calculations. Magnetization measurements are consistent with a
+diamagnetic host with a small amount of local moment bearing impurities.
+Although the residual resistivity ratio (RRR) for all samples studied was
+relatively low, ranging between 2.4 and 3.4, the compounds had non-saturating
+magnetoresistance (MR), reaching values of $\sim$ 17% and $\sim$ 70% at 4 K and
+9 T for SrAgSb and SrAuSb respectively. Band structure calculations, using the
+experimentally determined Wyckoff positions for the Sr, Ag/Au, and Sb atoms,
+show that whereas SrAgSb is a topologically trivial, but compensated,
+semimetal; SrAuSb is a topologically non-trivial, Dirac semimetal.",2005.02323v1
+2020-05-25,Dynamical signatures of quasiparticle interactions in quantum spin chains,"We study the transverse dynamical susceptibility of an antiferromagnetic
+spin$-1/2$ chain in presence of a longitudinal Zeeman field. In the low
+magnetization regime in the gapless phase, we show that the marginally
+irrelevant backscattering interaction between the spinons creates a non-zero
+gap between two branches of excitations at small momentum. We further
+demonstrate how this gap varies upon introducing a second neighbor
+antiferromagnetic interaction, vanishing in the limit of a non-interacting
+""spinon gas"". In the high magnetization regime, as the Zeeman field approaches
+the saturation value, we uncover the appearance of two-magnon bound states in
+the transverse susceptibility. This bound state feature generalizes the one
+arising from string states in the Bethe ansatz solution of the integrable case.
+Our results are based on numerically accurate, unbiased matrix-product-state
+techniques as well as analytic approximations.",2005.12399v1
+2020-06-17,Scaling the electrical current switching of exchange bias in fully-epitaxial antiferromagnet/ferromagnet bilayers,"While the electrical current manipulation of antiferromagnets (AFMs) has been
+demonstrated, the extent of the studied AFM materials has been limited with few
+systematic experiments and a poor understanding. We compare the electrical
+current switching of the exchange-bias field ($H_{ex}$) in
+AFM-Mn$_3A$N/ferromagnet-Co$_3$FeN bilayers. An applied pulse current can
+manipulate $H_{ex}$ with respect to the current density and FM layer
+magnetization, which shifts exponentially as a function of the current density.
+We found that the saturation current density and exponential decay constant
+$\tau$ increase with the local moment of AFM Mn atoms. Our results highlight
+the effect of the AFM local moment to electrical current switching of $H_{ex}$,
+although it has a near-zero net magnetization, and may provide a facile way to
+explore the electrical current manipulation of AFM materials.",2007.01070v1
+2020-07-21,New $τ$-based evaluation of the hadronic contribution to the vacuum polarization piece of the muon anomalous magnetic moment,"We revisit the isospin-breaking and electromagnetic corrections to the decay
+$\tau^-\to\pi^-\pi^0\nu_\tau$, which allow its use as input in the two-pion
+contribution to the (leading order) hadronic vacuum polarization part of the
+muon anomalous magnetic moment. We extend a previous resonance chiral
+Lagrangian analysis, which included those operators saturating the
+next-to-leading order chiral low energy constants, by including the
+contributions of the next subleading terms. As a result, we improve agreement
+between the two-pion tau decay and $e^+e^-$ data and reduce the discrepancy
+between experiment and the SM prediction of $a_\mu$ (using $\tau$ input).",2007.11019v3
+2020-08-04,Quantum correlations in the spin-1/2 Heisenberg XXZ chain with modulated Dzyaloshinskii-Moriya interaction,"We study a one-dimensional spin-1/2 XXZ Heisenberg model with alternating
+Dzyaloshinskii- Moriya interaction, using the numerical Lanczos method.
+Recently, the ground state (GS) phase diagram of this model has been
+established using the bosonization approach and extensive density matrix
+renormalization group computations. Four quantum phases - saturated
+ferromagnetic (FM), Luttinger liquid (LL), and two (C1 and C2) gapped phases
+with composite structure of GS order, characterized by the coexistence of
+long-range alternating dimer, chirality and antiferromagnetic order have been
+identified. Here we reexamine the same problem using the exact diagonalization
+Lanczos method for chains up to N = 26 sites and explicitly detect positions of
+quantum critical points (QCP) by investigating the quantum correlations as the
+entanglement and the quantum discord (QD). It is shown that the entanglement
+quantified by concurrence and the first derivative of the QD are able to reveal
+besides the standard FM QCP also the Berezinskii-Kosterlitz-Thouless (BKT)
+phase transition point between the LL and the gapped C1 phase and the Ising
+type critical point separating the C1 and C2 phases.",2008.01443v1
+2020-09-02,Giant inverse Faraday effect in Dirac semimetals,"We have studied helicity dependent photocurrent (HDP) in Bi-based Dirac
+semimetal thin films. HDP increases with film thickness before it saturates,
+changes its sign when the majority carrier type is changed from electrons to
+holes and takes a sharp peak when the Fermi level lies near the charge
+neutrality point. These results suggest that irradiation of circularly
+polarized light to Dirac semimetals induces an effective magnetic field that
+aligns the carrier spin along the light spin angular momentum and generates a
+spin current along the film normal. The effective magnetic field is estimated
+to be orders of magnitude larger than that caused by the inverse Faraday effect
+(IFE) in typical transition metals. We consider the small effective mass and
+the large $g$-factor, characteristics of Dirac semimetals with strong spin
+orbit coupling, are responsible for the giant IFE, opening pathways to develop
+systems with strong light-spin coupling.",2009.01388v1
+2020-09-07,Graded Index Confined Spin Waves in an Intermediate Domain Wall,"We propose a mathematical model for describing propagating confined modes in
+domain walls of intermediate angle between domains. The proposed model is
+derived from the linearised Bloch equations of motion and after reasonable
+assumptions, in the scenario of a thick enough magnetic patch, are accounted.
+The model shows that there is a clear dependence of the local wavenumber of the
+confined spin wave on the local angle of the wall and excitation frequency
+used, which leads to the definition of a local index of refraction in the wall
+as a function of such angle and frequency. Therefore, the model applies to 1-D
+propagating modes, although it also has physical implications for 2-D scenarios
+where a domain wall merges with a saturated magnetic region. Micromagnetic
+simulations are in good agreement with the predictions of the model and also
+give insight on the effects of curved finite structures may have on the
+propagating characteristics of spin waves in domain walls.",2009.03195v2
+2020-11-27,d0 Ferromagnetism in Ag-doped Monoclinic ZrO2 Compounds,"Recently d0 or intrinsic ferromagnetism was believed to provide an
+alternative pathway to transition metal induced ferromagnetism in oxide. In
+pursuit of augmenting the area of d0 ferromagnetism; we have undertaken to
+study the crystal structure and magnetic properties of Ag-doped ZrO2 compounds.
+Polycrystalline samples of Zr1-xAgxO2 (with x=0, 0.02, 0.04, 0.06 and 0.08)
+were prepared by solid-state reaction route. All the prepared compounds are
+found to crystallize in monoclinic symmetry of ZrO2. In our study, pure ZrO2
+compound exhibits paramagnetic behavior. However, the Ag-doped ZrO2 compounds
+exhibit ferromagnetic to paramagnetic transition. The Curie temperature was
+found to increase from 28.7 K for x=0.02 to 173.2 K for x= 0.08 doped ZrO2.
+Thus, the introduction of Ag in ZrO2 induces ferromagnetism with a large
+ThetaC. The measurements of hysteresis curves indicate that Ag doped ZrO2
+compounds exhibit hysteresis loops with a coercivity of around 1350 Oe.
+Moreover, increase in Ag concentration resulted increase in the value of
+saturation magnetization (MS); the maximum value of MS was recorded as 0.01
+{\mu}B/Ag ion for x= 0.06 sample. The sintering of sample at high temperature
+(13500C) diminishes the ferromagnetism and it leads to paramagnetic behaviour.",2011.13727v1
+2020-12-17,Electromagnetic ion cyclotron instability stimulated by the suprathermal ions in space plasmas: A quasi-linear approach,"In collision-poor space plasmas protons with an excess of kinetic energy or
+temperature in direction perpendicular to background magnetic field can excite
+the electromagnetic ion cyclotron (EMIC) instability. This instability is
+expected to be highly sensitive to suprathermal protons, which enhance the
+high-energy tails of the observed velocity distributions and are well
+reproduced by the (bi-)Kappa distribution functions. In this paper we present
+the results of a refined quasilinear (QL) approach, able to describe the
+effects of suprathermal protons on the extended temporal evolution of EMIC
+instability. It is thus shown that suprathermals have a systematic stimulating
+effect on the EMIC instability, enhancing not only the growth rates and the
+range of unstable wave-numbers, but also the magnetic fluctuating energy
+density reached at the saturation. In effect, the relaxation of anisotropic
+temperature becomes also more efficient, i.e., faster in time and closer to
+isotropy.",2012.09899v1
+2021-03-10,Crystal Growth of a New 8H Perovskite Sr8Os6.3O24 Exhibiting High TC Ferromagnetism,"Single crystals of a new twinned hexagonal perovskite compound Sr8Os6.3O24
+have been synthesized, and structural and magnetic properties have been
+determined. The compound crystallizes in a hexagonal cell with lattice
+parameters a = 9.6988(3) {\AA} and c = 18.1657(5) {\AA}. The structure is an
+eight-layered hexagonal B-site deficient perovskite with the layer sequence
+(ccch)2 and represents the first example of a hexagonal structure among 5d
+oxides adopting a twin option. The sample shows spontaneous ferromagnetic
+magnetization below 430 K with a small saturation moment of 0.11 {\mu}B/Os ion.
+This is the highest Curie temperature (TC) reported for any bulk perovskite
+containing only 5d ions at the B site.",2103.06305v1
+2021-04-30,Spin polarization and magnetotransport properties of systematically disordered $\mathrm{Fe}_{60}\mathrm{Al}_{40}$ thin films,"We investigate the evolution of spin polarization, spontaneous Hall angle
+(SHA), saturation magnetization and Curie temperature of $B2$-ordered
+Fe$_{60}$Al$_{40}$ thin films under varying antisite disorder, induced by
+Ne$^{+}$-ion irradiation. The spin polarization increases monotonically as a
+function of ion fluence. A relatively high polarization of 46 % and the SHA of
+3.1 % are achieved on 40 nm thick films irradiated with 2 $\cdot$ 10$^{16}$
+ions/cm$^2$ at 30 keV. An interesting divergence in the trends of the
+magnetization and SHA is observed for low disorder concentrations. The high
+spin polarization and its broad tunability range make ion-irradiated
+Fe$_{60}$Al$_{40}$ a promising material for application in spin electronic
+devices.",2104.14792v1
+2021-05-11,First-principles calculations and experimental studies on Co2FeGe Heusler alloy nanoparticles for spintronics applications,"Here, we report the synthesis and physical properties of Co2FeGe (CFG)
+Heusler alloy (HA) nanoparticles (NPs). The NPs of size 23 nm are prepared
+using the co-precipitation method. X-ray and selected area electron diffraction
+patterns have confirmed the cubic Heusler phase of the NPs with the
+A2-disorder. These NPs are soft ferromagnetic, and exhibit a high saturation
+magnetization (Ms) along with a very high Curie temperature (Tc) of 1060 K. The
+observed Tc value matches closely with the theoretically calculated one
+following a model provided by Wurmehl et al. [1]. The high Ms and Tc make the
+present system a potential candidate for magnetically activated nano-devices
+working at high temperatures. The near-integral value 5.9 mehoB/f.u. of Ms at
+low temperatures indicates that the half-metallic ferromagnetism is preserved
+even in the particles even on the 20 nm length scale. Additionally, we have
+facilitated the existing HA-NP preparation method, which can be used in
+synthesizing other HA-NPs. The first-principles density functional theory
+computations complement the experimental results.",2105.05200v1
+2021-06-14,Linear unsaturated magnetoresistance in YSi single crystal,"Linear magnetoresistance is a phenomenon that has been observed in a few
+topological compounds that originate from classical and quantum phenomena.
+Here, we performed electrical transport measurements, in zero and applied
+magnetic fields, on the YSi single crystal along all three principal
+crystallographic directions of the orthorhombic crystal structure. For
+$I~\parallel~[001]$ and $H~\parallel~[100]$ direction above $\approx 10$~T,
+mobility fluctuation driven linear magnetoresistance is observed without any
+sign of saturation up to $14$~T magnetic field. Anisotropy in the Fermi surface
+is immanent from the angular dependence of the magnetoresistance. Kohler rule
+violation is observed in this system and Hall data signifies multiple charge
+carriers in YSi.",2106.07264v1
+2021-06-16,"Unusual dynamic susceptibility arising from soft ferromagnetic domains in MnBi8Te13 and Sb-doped MnBi2nTe3n+1 (n=2, 3)","MnBi2nTe3n+1(MBT) is the first intrinsic magnetic topological insulator and
+is promising to hostemergent phenomena such as quantum anomalous Hall effect.
+They can be made ferromagnetic by having n >= 4 or with Sb doping. We studied
+the magnetic dynamics in a few selected ferromag-netic (FM) MBT compounds,
+including MnBi8Te13and Sb doped MnBi2nTe3n+1(n= 2,3) usingAC susceptibility and
+magneto-optical imaging. Slow relaxation behavior is observed in all
+threecompounds, suggesting its universality among FM MBT. We attribute the
+origin of the relaxationbehavior to the irreversible domain movements since
+they only appear below the saturation fieldswhen ferromagnetic domains form.
+The very soft ferromagnetic domain nature is revealed by thelow-field
+fine-structured domains and high-field sea-urchin-shaped remanent-state domains
+imagedvia our magneto-optical measurements. Finally, we ascribe the rare
+""double-peak"" behavior ob-served in the AC susceptibility under small DC bias
+fields to the very soft ferromagnetic domainformations.",2106.08969v1
+2021-07-13,Phase diagram and spin waves in the frustrated ferro-antiferromagnet SrZnVO(PO4)2,"Single crystals of the frustrated S=1/2 ferro-antiferromagnetic proximate
+square lattice material SrZnZnVO(PO$_4$)$_2$ are studied in magnetometric,
+calorimetric, neutron diffraction and inelastic neutron scattering experiments.
+The measured spin wave spectrum reveals a substantial degree of magnetic
+frustration and a large quantum renormalization of the exchange constants. The
+H-T magnetic phase diagram is established. It features a novel pre-saturation
+phase, which appears for only one particular field orientation. The results are
+discussed noting the similarities and differences with the previously studied
+and similarly structured Pb$_2$VO(PO$_4$)$_2$ compound.",2107.06114v1
+2021-09-04,"Anomalous Hall effect in ferrimagnetic metal RMn6Sn6 (R = Tb, Dy, Ho) with clean Mn kagome lattice","Kagome lattice, made of corner-sharing triangles, provides an excellent
+platform for hosting exotic topological quantum states. Here we systematically
+studied the magnetic and transport properties of RMn6Sn6 (R = Tb, Dy, Ho) with
+clean Mn kagome lattice. All the compounds have a collinear ferrimagnetic
+structure with different easy axis at low temperature. The low-temperature
+magnetoresistance (MR) is positive and has no tendency to saturate below 7 T,
+while the MR gradually declines and becomes negative with the increasing
+temperature. A large intrinsic anomalous Hall conductivity about 250
+{\Omega}-1cm-1, 40 {\Omega}-1cm-1, 95 {\Omega}-1cm-1 is observed for TbMn6Sn6,
+DyMn6Sn6, HoMn6Sn6, respectively. Our results imply that RMn6Sn6 system is an
+excellent platform to discover other intimately related topological or quantum
+phenomena and also tune the electronic and magnetic properties in future
+studies.",2109.01866v1
+2021-09-12,Modeling of A Realistic DC Source in A CVSR,"Continuously Variable Series Reactor (CVSR) can adjust the total reactance in
+an ac circuit using the saturation characteristic of the ferromagnetic core,
+shared by an ac and a dc winding. The bias magnetic flux produced by the dc
+winding can regulate the equivalent ac inductance in order to control power
+flow, damp oscillations, or limit fault currents. Gyrator-Capacitor approach is
+used to model the interface between the magnetic and the electric circuits. Two
+different dc control source models are considered: the usual ideal dc source
+and a realistic dc source composed of a power electronics-based converter and
+an ac voltage source. This paper investigates CVSR's behaviour in terms of
+induced voltage across ac winding, flux densities (B) throughout the CVSR core,
+and power interchange with the dc control circuit during normal conditions in
+both cases.",2109.05568v1
+2021-09-16,Large Magnetoresistance and Weak Antilocalization in V1-delta Sb2 Single Crystal,"The binary pnictide semimetals have attracted considerable attention due to
+their fantastic physical properties that include topological effects, negative
+magnetoresistance, Weyl fermions and large non-saturation magnetoresistance. In
+this paper, we have successfully grown the high-quality V1-deltaSb2 single
+crystals by Sb flux method and investigated their electronic transport
+properties. A large positive magnetoresistance that reaches 477% under a
+magnetic field of 12 T at T = 1.8 K was observed. Notably, the
+magnetoresistance showed a cusp-like feature at the low magnetic fields and
+such feature weakened gradually as the temperature increased, which indicated
+the presence of weak antilocalization effect (WAL). The angle-dependent
+magnetoconductance and the ultra-large prefactor alpha extracted from the
+Hikami-Larkin-Nagaoka equation revealed that the WAL effect is a 3D bulk effect
+originated from the three-dimensional bulk spin-orbital coupling.",2109.07736v1
+2021-10-09,Enhancement of spin-orbit coupling and magnetic scattering in hydrogenated graphene,"Spin-orbit coupling (SOC) can provide essential tools to manipulate electron
+spins in two-dimensional materials like graphene, which is of great interest
+for both fundamental physics and spintronics application. In this paper, we
+report the low-field magnetotransport of in situ hydrogenated graphene where
+hydrogen atoms are attached to the graphene surface in continuous low
+temperature and vacuum environment. Transition from weak localization to weak
+antilocalization with increasing hydrogen adatom density is observed,
+indicating enhancing Bychkov-Rashba-type SOC in a mirror symmetry broken
+system. From the low-temperature saturation of phase breaking scattering rate,
+the existence of spin-flip scattering is identified, which corroborates the
+existence of magnetic moments in hydrogenated graphene.",2110.04477v1
+2021-10-12,Large positive magnetoresistance in photocarrier doping potassium tantalites in the extreme quantum limit,"We report on a high-field magnetotransport study of KTaO3 single crystals.
+This material is a promising candidate to study in the extreme quantum limit
+(EQL). By photocarrier doping with 360 nm light, we have observed a significant
+positive, non-saturating, and linear magnetoresistance at low temperatures
+accompanied by a vanishing Hall coefficient. When cooled down to 10 K and
+subjected to a magnetic field of 12 T, the value of magnetoresistance of KTaO3
+(100) is increased by as much as 433%. Such behavior can be attributed to all
+electrons occupying only the lowest Landau level in the EQL. In this state, a
+quantum magnetoresistance is produced. This result provides novel insights into
+the next generation of magnetic devices based on complex materials and adds a
+new family of materials with positive magnetoresistance.",2110.05791v1
+2021-10-27,SN 2008iy circumstellar interaction: Bright and lesser light effect,"Optical photometry and spectra of the luminous type IIn supernova SN~2008iy
+are analysed in detail with implications for cosmic ray acceleration and the
+radio emission. The light curve and expansion velocities indicate ejecta with
+the kinetic energy of $3\times10^{51}$ erg to collide with the $\sim10$ Msun
+circumstellar envelope. The luminous Ha is explained as originated primarily
+from circumstellar clouds interacting with the forward shock. For the first
+time the fluorescent OI 8446A emission is used to demonstrate that the cloud
+fragmentation cascade spans a scale range > 2.3 dex. The narrow circumstellar
+Ha permitted us to estimate the acceleration efficiency of cosmic rays. The
+found value is close to the efficiency inferred in the same way for other two
+SNe~IIn, SN~1997eg and SN~2002ic. The efficiency of cosmic ray acceleration is
+utilized to reproduce the radio flux from SN~2008iy for the amplified magnetic
+field consistent with the saturated turbulent magnetic field in the diffusive
+shock acceleration mechanism.",2110.14409v1
+2021-11-12,The QCD Adler function and the muon $g-2$ anomaly from renormalons,"We describe the Adler function in Quantum Chromodynamics using a transseries
+representation within a resurgent framework. The approach is based on a
+Borel-Ecalle resummation of the infrared renormalons combined with an effective
+running for the strong coupling. The new approach is flexible enough to give
+values in agreement with the current Adler function determinations. We then
+apply our finding to the muon's anomalous magnetic moment studying the
+possibility of saturating, solely in terms of the vacuum polarization function,
+the current discrepancy between the best Standard Model value for the muon's
+anomalous magnetic moment and the experimental value obtained by the most
+recent muon g-2 collaboration. The latter shows that the Adler function's new
+representation can also be consistent with recent lattice determinations.",2111.06792v3
+2021-12-23,NMR evidence against a spin-nematic nature of the presaturation phase in the frustrated magnet SrZnVO(PO4)2,"Using $^{31}$P nuclear magnetic resonance (NMR) we investigate the recently
+discovered presaturation phase in the highly frustrated two-dimensional spin
+system SrZnVO(PO$_4$)$_2$ [F. Landolt et al., Phys. Rev. B 104, 224435 (2021)].
+Our data provide two pieces of evidence against the presumed spin-nematic
+character of this phase: i) NMR spectra reveal that it hosts a dipolar spin
+order and ii) the 1/$T_1$ relaxation rate data recorded above the saturation
+field can be fitted by the sum of a single-magnon term, exponential in the gap,
+and a critical second-order term, exponential in the triple gap, leaving no
+space for a nematic spin dynamics, characterized by a double-gap exponential.
+We explain the unexpectedly broad validity of the simple fit and the related
+critical spin dynamics.",2112.12603v2
+2022-02-01,Numerical Model Of Harmonic Hall Voltage Detection For Spintronic Devices,"We present a numerical macrospin model for harmonic voltage detection in
+multilayer spintronic devices. The core of the computational backend is based
+on the Landau-Lifshitz-Gilbert-Slonczewski equation, which combines high
+performance with satisfactory, for large-scale applications, agreement with the
+experimental results. We compare the simulations with the experimental findings
+in Ta/CoFeB bilayer system for angular- and magnetic field-dependent resistance
+measurements, electrically detected magnetisation dynamics, and harmonic Hall
+voltage detection. Using simulated scans of the selected system parameters such
+as the polar angle $\theta$, magnetisation saturation
+($\mu_\textrm{0}M_\textrm{s}$) or uniaxial magnetic anisotropy ($K_\textrm{u}$)
+we show the resultant changes in the harmonic Hall voltage, demonstrating the
+dominating influence of the $\mu_\textrm{0}M_\textrm{s}$ on the first and
+second harmonics. In the spin-diode ferromagnetic resonance (SD-FMR) technique
+resonance method the ($\mu_\textrm{0}M_\textrm{s}$, $K_\textrm{u}$) parameter
+space may be optimised numerically to obtain a set of viable curves that fit
+the experimental data.",2202.00364v1
+2022-02-17,The role of slow magnetostrophic waves in the formation of the axial dipole in planetary dynamos,"The preference for the axial dipole in planetary dynamos is investigated
+through the analysis of wave motions in spherical dynamo models. Our study
+focuses on the role of slow magnetostrophic waves, which are generated from
+localized balances between the Lorentz, Coriolis and buoyancy (MAC) forces.
+Since the slow waves are known to intensify with increasing field strength,
+simulations in which the field grows from a small seed towards saturation are
+useful in understanding the role of these waves in dynamo action. Axial group
+velocity measurements in the energy-containing scales show that fast inertial
+waves slightly modified by the magnetic field and buoyancy are dominant under
+weak fields. However, the dominance of the slow waves is evident for strong
+fields satisfying $|\omega_M/\omega_C| \sim $ 0.1, where $\omega_M$ and
+$\omega_C$ are the frequencies of the Alfv\'en and inertial waves respectively.
+A MAC wave window of azimuthal wavenumbers is identified wherein helicity
+generation by the slow waves strongly correlates with dipole generation.
+Analysis of the magnetic induction equation suggests a poloidal--poloidal field
+conversion in the formation of the dipole. Finally, the attenuation of slow
+waves may result in polarity reversals in a strongly driven Earth's core.",2202.08784v1
+2022-03-09,Exchange spin waves in thin films with gradient composition,"We report investigation of ferromagnetic resonance phenomenon in
+ferromagnetic thin films with essentially non-uniform composition. Epitaxial
+Pd-Fe thin film with linear distribution of Fe content across the thickness is
+used as the model material. Anomalous perpendicular standing spin waves are
+observed and quantified using the collective dynamic equation. Numerical
+analysis yields the exchange stiffness constant for diluted Pd-Fe alloy
+$D=2A/\mu_0M_s=15$~T$\cdot$nm$^2$ and the ratio of the effective magnetization
+to the saturation magnetization $M_{eff}/M_s=1.16$. It is demonstrated that,
+overall, engineering of thin films with non-uniform composition across the
+thickness can be used for high-frequency or low-field magnonic operations using
+exchange spin waves.",2203.05014v1
+2022-03-22,Nonlinear magnetoconductivity in Weyl and multi-Weyl semimetal in quantizing magnetic field,"Magnetotransport and magneto-optics experiments offer a very powerful probe
+for studying the physical properties of materials. Here, we investigate the
+second-order nonlinear magnetoconductivity of tilted type-I Weyl and multi-Weyl
+semimetal. In contrast to the presence of chiral anomaly in the linear response
+regime, we show that Weyl semimetal do not host chiral charge pumping in the
+nonlinear transport regime. We predict that an inversion symmetry broken and
+tilted Weyl semimetal can support finite longitudinal nonlinear
+magnetoconductivity, which is otherwise absent in untilted Weyl semimetal. The
+nonlinear magnetoconductivity vanishes in the ultra-quantum limit, oscillates
+in the intermediate magnetic field regime and saturates in the semiclassical
+limit. The nonlinear magnetoconductivity depends intricately on the tilt
+orientation, and it can be used to determine the tilt orientation in Weyl and
+multi-Weyl semimetals, via nonlinear magnetoresistivity or second harmonic
+generation experiments.",2203.11980v2
+2022-03-23,Topological Hybrids of Magnons and Magnon Bound Pairs,"We consider quantum condensed matter systems without particle-number
+conservation. Since the particle number is not a good quantum number, states
+belonging to different particle-number sectors can hybridize, which causes
+topological anticrossings in the spectrum. The resulting spectral gaps support
+chiral edge excitations whose wavefunction is a superposition of states in the
+two hybridized sectors. This situation is realized in fully saturated
+spin-anisotropic quantum magnets without spin conservation, in which single
+magnons hybridize with magnon bound pairs, i.e., two-magnon bound states. The
+resulting chiral edge excitations are exotic composites that carry mixed
+spin-multipolar character, inheriting spin-dipolar and spin-quadrupolar
+character from their single-particleness and two-particleness, respectively. In
+contrast to established topological magnons, the topological effects discussed
+here are of genuine quantum mechanical origin and vanish in the classical
+limit. We discuss implications for both intrinsic anomalous Hall-type transport
+and beyond-spintronics computation paradigms. We conclude that fully polarized
+quantum magnets are a promising platform for topology caused by hybridizations
+between particle-number sectors, complementing the field of ultracold atoms
+working with a conserved number of particles.",2203.12374v1
+2022-05-23,Linear Flavor-Wave Analysis of SU(4)-Symmetric Tetramer Model with Population Imbalance,"We study the quantum magnetism of the SU(4) Mott insulator in a square
+optical superlattice, in which atoms with four nuclear-spin components strongly
+interact with each other, in the presence of an external field that controls
+the imbalance between the population of two components and that of the other
+two. This is a natural extension of the physics of spin-dimer materials under
+strong magnetic field. We apply an extended linear flavor-wave theory based on
+four-site plaquettes and unveil the ground-state phase diagram and excitation
+spectra. When the population of the four components is balanced and the
+plaquesttes are weakly coupled, the ground state is approximately given by the
+direct product of local SU(4)-singlet states. In high-field, the system reaches
+a ""saturated state"" where only two components are present. Our main finding is
+a nontrivial intermediate phase, which has a checkerboard-like arrangement of
+the SU(4)-singlet and four-site resonating-valence-bond states.",2205.11155v1
+2022-06-14,Locked mode disruptions in DIII-D and application to ITER,"Disruptions are a serious problem in tokamaks, in which thermal and magnetic
+energy confinement is lost. This paper uses data from the DIII-D experiment,
+theory, and simulations to demonstrate that resistive wall tearing modes (RWTM)
+produce the thermal quench (TQ) in a typical locked mode shot. Analysis of the
+linear RWTM dispersion relation shows the parameter dependence of the growth
+rate, particularly on the resistive wall time. Linear simulations of the locked
+mode equilibrium show that it is unstable with a resistive wall, and stable
+with an ideally conducting wall. Nonlinear simulations demonstrate that the
+RWTM grows to sufficient amplitude to cause a complete thermal quench. The RWTM
+growth time is proportional to the thermal quench time. The nonlinearly
+saturated RWTM magnetic perturbation amplitude agrees with experimental
+measurements. The onset condition is that the q = 2 rational surface is
+sufficiently close to the resistive wall. Collectively, this identifies the
+RWTM as the cause of the TQ. In ITER, RWTMs will produce long TQ times compared
+to present-day experiments. ITER disruptions may be significantly more benign
+than previously predicted.",2206.06773v2
+2022-07-12,Photonic heat transport from weak to strong coupling,"Superconducting circuits provide a favorable platform for quantum
+thermodynamic experiments. An important component for such experiments is a
+heat valve, i.e. a device which allows one to control the heat power flowing
+through the system. Here we theoretically study the heat valve based on a
+superconducting quantum interference device (SQUID) coupled to two heat baths
+via two resonators. The heat current in such system can be tuned by magnetic
+flux. We investigate how does the heat current modulation depend on the
+coupling strength g between the SQUID and the resonators. In the weak coupling
+regime the heat current modulation grows as g2, but, surprisingly, at the
+intermediate coupling it can be strongly suppressed. This effect is linked to
+the resonant nature of the heat transport at weak coupling, where the heat
+current dependence on the magnetic flux is a periodic set of narrow peaks. At
+the intermediate coupling, the peaks become broader and overlap, thus reducing
+the heat modulation. At very strong coupling the heat modulation grows again
+and finally saturates at a constant value.",2207.05586v1
+2022-07-29,Three-Dimensional Neutron Far-Field Tomography of a Bulk Skyrmion Lattice,"Skyrmions are topologically-protected spin textures thought to nucleate and
+annihilate on points of vanishing magnetization, called Bloch points. However,
+owing to a lack of bulk techniques, experimental visualizations of skyrmion
+lattices and their stabilization through defects in three-dimensions remain
+elusive. Here, we present a tomographic algorithm applied to a
+Co$_8$Zn$_8$Mn$_4$ skyrmion lattice host, processing multi-projection small
+angle neutron scattering measurements to generate mean scattering feature
+reconstructions (MSFR) of the bulk spin textures. Digital phantoms validated
+the algorithm; reconstructions of the sample show a disordered skyrmion lattice
+with a topological saturation of 63~\%, exhibiting three-dimensional
+topological transitions through two different emergent (anti)monopole defect
+pathways with densities of 147~$\mu$m$^{-3}$ and 21~$\mu \mathrm{m}^{-3}$ for
+branching and segmentation events, respectively. Our techniques produce
+experimentally-informed visualizations of bulk skyrmion lattice structures and
+defects, enabling future bulk studies over a wide variety of sample shapes and
+chemistries, magnetic phases, and external parameters.",2208.00023v1
+2022-08-31,Possible origin of extremely large magnetoresistance in the topological insulator CaBi2 single crystal,"CaBi2 has been experimentally found to be a superconductor with a transition
+temperature of 2 K and identified as a topological insulator via spin- and
+angle-resolved photoemission spectroscopy, which makes it a possible platform
+to study the interplay between superconductivity and topology. But the detailed
+transport properties for CaBi2 single crystal remain unexplored in experiments.
+Here, we systematically studied the magneto-transport properties of CaBi2
+single crystal grown by a flux method. CaBi2 shows a magnetic-field-induced
+upturn behavior with a plateau in resistivity at low temperature. An extremely
+large and non-saturating magnetoresistance up to ~15000% at 3 K and 12 T was
+achieved. The possible reason for the magnetic field and temperature dependence
+of resistivity and extremely large magnetoresistance at low temperature was
+discussed by adopting the Kohler's scaling law, which can be understood by the
+compensation effect confirmed by the Hall Effect measurement.",2208.14595v1
+2022-11-08,Short-distance constraints on the hadronic light-by-light,"The muon anomalous magnetic moment continues to attract interest due to the
+potential tension between experimental measurement [1,2] and the Standard Model
+prediction [3]. The hadronic light-by-light contribution to the magnetic moment
+is one of the two diagrammatic topologies currently saturating the theoretical
+uncertainty. With the aim of improving precision on the hadronic light-by-light
+in a data-driven approach founded on dispersion theory [4,5], we derive various
+short-distance constraints of the underlying correlation function of four
+electromagnetic currents. Here, we present our previous progress in the purely
+short-distance regime and current efforts in the so-called Melnikov-Vainshtein
+limit.",2211.04068v1
+2022-11-20,Spin-wave spectra in antidot lattice with inhomogeneous perpendicular magnetocrystalline anisotropy,"Magnonic crystals are structures with periodically varied magnetic properties
+that are used to control collective spin-wave excitations. With micromagnetic
+simulations, we study spin-wave spectra in a 2D antidot lattice based on a
+multilayered thin film with perpendicular magnetic anisotropy (PMA). We show
+that the modification of the PMA near the antidot edges introduces interesting
+modifications to the spin-wave spectra, even in a fully saturated state. In
+particular, the spectra split in two types of excitations, bulk modes with
+amplitude concentrated in a homogeneous part of antidot lattice, and edge modes
+with an amplitude localized in the rims of reduced PMA at the antidot edges.
+Their dependence on the geometrical or material parameters is distinct but at
+resonance conditions fulfilled, we found strong hybridization between bulk and
+radial edge modes. Interestingly, the hybridization between the fundamental
+modes in bulk and rim is of magnetostatic origin but the exchange interactions
+determine the coupling between higher-order radial rim modes and the
+fundamental bulk mode of the antidot lattice.",2211.11002v1
+2022-12-05,Probing Accretion Turbulence in the Galactic Center with EHT Polarimetry,"Magnetic fields grown by instabilities driven by differential rotation are
+believed to be essential to accretion onto black holes. These instabilities
+saturate in a turbulent state; therefore, the spatial and temporal variability
+in the horizon-resolving images of Sagittarius A* (Sgr A*) will be able to
+empirically assess this critical aspect of accretion theory. However,
+interstellar scattering blurs high-frequency radio images from the Galactic
+center and introduces spurious small-scale structures, complicating the
+interpretation of spatial fluctuations in the image. We explore the impact of
+interstellar scattering on the polarized images of Sgr A* and demonstrate that
+for credible physical parameters, the intervening scattering is
+non-birefringent. Therefore, we construct a scattering mitigation scheme that
+exploits horizon-resolving polarized millimeter/submillimeter VLBI observations
+to generate statistical measures of the intrinsic spatial fluctuations and
+therefore the underlying accretion flow turbulence. An optimal polarization
+basis is identified, corresponding to measurements of the fluctuations in
+magnetic field orientation in three dimensions. We validate our mitigation
+scheme using simulated data sets and find that current and future ground-based
+experiments will readily be able to accurately measure the image-fluctuation
+power spectrum.",2212.02544v1
+2022-12-19,Towards an effective action for chiral magnetohydrodynamics,"We consider chiral magnetohydrodynamics, i.e. a finite-temperature system
+where an axial $U(1)$ current is not conserved due to an Adler-Bell-Jackiw
+anomaly saturated by the dynamical operator $F_{\mu\nu} \tilde{F}^{\mu\nu}$. We
+express this anomaly in terms of the 1-form symmetry associated with magnetic
+flux conservation and study its realization at finite temperature. We present
+Euclidean generating functional and dissipative action approaches to the
+dynamics and reproduce some aspects of chiral MHD phenomenology from an
+effective theory viewpoint, including the chiral separation and magnetic
+effects. We also discuss the construction of non-invertible axial symmetry
+defect operators in our formalism.",2212.09787v1
+2023-02-06,Interaction-induced Metal to Topological Insulator Transition,"By means of exact diagonalizations, the Bernevig-Hughes-Zhang model at
+quarter-filling in the limit of strong Hubbard on-site repulsion is
+investigated. We find that the non-interacting metallic state will be turned
+into a Chern insulator with saturated magnetization under strong correlations.
+That is, at such a metal-insulator transition, both the topological and the
+magnetic properties of the system are changed due to spontaneous breaking of
+time reversal symmetry in the ground states. According to our findings, this
+topological phase transition seems to be of first order. Our results illustrate
+the interesting physics in topological Mott transitions and provide guidance to
+the search of more interaction-induced topological phases in similar systems.",2302.02771v1
+2023-04-18,A Positive Energy Theorem for AdS Solitons,"The uncharged AdS$_4$ soliton has been recently shown to be continuously
+connected to a magnetic, supersymmetric AdS$_4$ soliton within $\mathcal{N}=8$
+gauged supergravity. By constructing the asymptotic superalgebra, we establish
+a positive energy theorem for the magnetic AdS$_4$ solitons admitting
+well-defined asymptotic Killing spinors, antiperiodic on a contractible $S^1$.
+We show that there exists only one discrete solution endowed with these
+boundary conditions satisfying the bound, the latter being saturated by the
+null energy supersymmetric configuration. Despite having negative energy, the
+uncharged AdS$_4$ soliton does not contradict the positive energy theorem, as
+it does not admit well-defined asymptotic Killing spinors.",2304.09201v2
+2023-05-06,Giant magnetostriction in La2CoMnO6 synthesized by microwave irradiation,"Polycrystalline insulating ferromagnetic double perovskite La2CoMnO6
+possessing monoclinic structure and a high ferromagnetic Curie temperature (TC
+= 222 K) was rapidly synthesized ( 30 min) by irradiating stoichiometric
+mixture of oxides with the microwave. The sample exhibits negative
+magnetostriction, i.e., contraction of length along the magnetic field
+direction in the ferromagnetic state. At 10 K, the parallel magnetostriction
+does not show saturation up to a magnetic field of 50 kOe where it reaches 610
+ppm which is one of the highest values of magnetostriction found so far among
+perovskite oxides with 3d ions. The magnitude of magnetostriction decreases
+monotonically as the temperature increases and becomes negligible above TC. The
+giant magnetostriction in this double perovskite is suggested to originate from
+large spin-orbit coupling associated with Co2+ (d7) cation. The obtained
+magnetostriction value is comparable to 630 ppm in an identical composition
+obtained through solid-state reaction over several days in a conventional
+furnace which indicates the advantages of microwave-assisted synthesis in
+saving reaction time and electric power without deteriorating physical
+properties.",2305.03886v1
+2023-05-22,Singlet quantum phases and magnetization of the frustrated spin-1/2 ladder with ferromagnetic (F) exchange in legs and alternating F-AF exchange in rungs,"The magnetization $M(h)$ is used to identify three singlet quantum phases of
+the ladder with isotropic exchange interactions. The Dimer phase with
+frustrated F exchanges in rungs and legs has a first-order $M(h)$ transition at
+$0$ K from singlet to ferromagnetic at the saturation field $h_s$. The
+Haldane-DAF phase with strong F exchange in rungs and net AF exchange between
+rungs has continuous $M(h)$ and is adiabatically connected to the $S = 1$
+Heisenberg AF chain. The AF phase with strong F exchange in legs and net AF
+exchange between legs has continuous $M(h)$ and is adiabatically connected to
+the spin-1/2 $J_1-J_2$ model with $J_1 > 0$ and $J_2 < 0$. All three singlet
+phases have finite gaps to the lowest triplet state.",2305.12884v1
+2023-06-20,Tayler-Spruit dynamos in simulated radiative stellar layers,"The Tayler-Spruit dynamo mechanism has been proposed two decades ago as a
+plausible mechanism to transport angular momentum in radiative stellar layers.
+Direct numerical simulations are still needed to understand its trigger
+conditions and the saturation mechanisms. The present study follows up on
+(Petitdemange et al. 2023), where we reported the first numerical simulations
+of a Tayler-Spruit dynamo cycle. Here we extend the explored parameter space to
+assess in particular the influence of stratification on the dynamo solutions.
+We also present numerical verification of theoretical assumptions made in
+(Spruit 2002), which are instrumental in deriving the classical prescription
+for angular momentum transport implemented in stellar evolution codes. A
+simplified radiative layer is modeled numerically by considering the dynamics
+of a stably-stratified, differentially rotating, magnetized fluid in a
+spherical shell. Our simulations display a diversity of magnetic field
+topologies and amplitudes depending on the flow parameters, including
+hemispherical solutions. The Tayler-Spruit dynamos reported here are found to
+satisfy magnetostrophic equilibrium and achieve efficient turbulent transport
+of angular momentum, following Spruit's heuristic prediction.",2306.11711v3
+2023-06-29,Zeeman field-induced two-dimensional Weyl semimetal phase in cadmium arsenide,"We report a topological phase transition in quantum-confined cadmium arsenide
+(Cd3As2) thin films under an in-plane Zeeman field when the Fermi level is
+tuned into the topological gap via an electric field. Symmetry considerations
+in this case predict the appearance of a two-dimensional Weyl semimetal (2D
+WSM), with a pair of Weyl nodes of opposite chirality at charge neutrality that
+are protected by space-time inversion (C2T) symmetry. We show that the 2D WSM
+phase displays unique transport signatures, including saturated resistivities
+on the order of h/e^2 that persist over a range of in-plane magnetic fields.
+Moreover, applying a small out-of-plane magnetic field, while keeping the
+in-plane field within the stability range of the 2D WSM phase, gives rise to a
+well-developed odd integer quantum Hall effect, characteristic of degenerate,
+massive Weyl fermions. A minimal four-band k.p model of Cd3As2, which
+incorporates first-principles effective g factors, qualitatively explains our
+findings.",2306.16794v1
+2023-07-04,Normal state magneto transport properties of FeSe$_{0.5}$Te$_{0.5}$ superconductor: The role of topological surface states,"Doped Iron Chalcogenide (FeCh) superconductors are extensively studied in the
+context of topological superconductivity. However, the evidence of topological
+surface states in electrical transport measurements of the doped FeCh system is
+yet warranted. In the present letter, we performed angle-dependent magneto
+transport measurements on a single crystal of a doped FeCh system, i.e.,
+FeSe$_{0.5}$Te$_{0.5}$. A non-saturating linear magnetoresistance (MR) has been
+observed under the magnetic field up to 14 T in the normal state of
+FeSe$_{0.5}$Te$_{0.5}$. The MR is shown to possess anisotropy, which indicates
+the presence of topological surface states in FeSe$_{0.5}$Te$_{0.5}$.
+Angle-dependent Magneto-conductivity (MC) at low magnetic fields has been
+modelled by Hikami Larkin Nagaoka (HLN) formalism, which shows the presence of
+weak antilocalization (WAL) effect in FeSe$_{0.5}$Te$_{0.5}$. The observed WAL
+effect is found to be 2D in nature through angle-dependent magneto transport
+measurements. Theoretical calculations based on Density Functional Theory (DFT)
+are also performed to get more confidence on the presence of topological
+surface states in FeSe$_{0.5}$Te$_{0.5}$.",2307.01476v1
+2023-09-06,Charge-transfer-driven enhanced room-temperature ferromagnetism in BiFeO$_3$/Ag nanocomposite,"We report observation of more than an order of magnitude jump in saturation
+magnetization in BiFeO$_3$/Ag nanocomposite at room temperature compared to
+what is observed in bare BiFeO$_3$ nanoparticles. Using transmission electron
+microscopy together with energy dispersive x-ray spectra (which maps the
+element concentration across the BiFeO$_3$/Ag interface) and x-ray
+photoelectron spectroscopy, we show that both the observed specific
+self-assembly pattern of BiFeO$_3$ and Ag nanoparticles and the charge transfer
+between Ag and O are responsible for such an enormous rise in room-temperature
+magnetization. The BiFeO$_3$/Ag nanocomposites, therefore, could prove to be
+extremely useful for a variety of applications including biomedical.",2309.02845v1
+2023-09-18,Large Nonreciprocity of Shear-Horizontal Surface Acoustic Waves induced by Magnetoelastic Bilayers,"We report large nonreciprocity in the transmission of shear-horizontal
+surface acoustic waves (SAWs) on LiTaO3 substrate coated with a FeCoSiB/NiFeCu
+magnetoelastic bilayer. The large difference in saturation magnetization of the
+two layers not only brings nonreciprocal spin waves (SWs), but also ensures the
+phonon-magnon (SAWs-SWs) coupling at relatively low wavenumbers. It is found
+that the angle between the magnetization and the wavevector play important
+roles in determining the strength of magnetoelastic coupling and
+nonreciprocity, simultaneously. A large nonreciprocal transmission of SAWs
+about 30 dB (i.e. 60 dB/mm) is demonstrated at 2.33 GHz. In addition, the
+dispersion relation between coupled SH-SAWs and nonreciprocal SWs is developed,
+which provide a good insight into the observed phenomena. Our results offer a
+convenient approach to implement nonreciprocal SAW isolators or circulators.",2309.09521v1
+2023-09-21,High-Field Optical Cesium Magnetometer for Magnetic Resonance Imaging,"We present a novel high-field optical quantum magnetometer based on saturated
+absorption spectroscopy on the extreme angular-momentum states of the cesium D2
+line. With key features including continuous readout, high sampling rate, and
+sensitivity and accuracy in the ppm-range, it represents a competitive
+alternative to conventional techniques for measuring magnetic fields of several
+teslas. The prototype has four small separate field probes, and all support
+electronics and optics are fitted into a single 19-inch rack to make it
+compact, mobile, and robust. The field probes are fiber coupled and made from
+non-metallic components, allowing them to be easily and safely positioned
+inside a 7 T MRI scanner. We demonstrate the capabilities of this magnetometer
+by measuring two different MRI sequences, and we show how it can be used to
+reveal imperfections in the gradient coil system, to highlight the potential
+applications in medical MRI. We propose the term EXAAQ (EXtreme
+Angular-momentum Absorption-spectroscopy Quantum) magnetometry, for this novel
+method.",2309.12006v2
+2023-10-09,Spatial asymmetry of optically excited spin waves in anisotropic ferromagnetic film,"We analytically discuss and micromagnetically prove the ways to tune the
+spatial asymmetry of the initial phase, amplitude, and wavevectors of
+magnetostatic waves driven by ultrafast laser excitation. We consider that the
+optical pulse heats a thin ferromagnetic metallic film and abruptly decreases
+the saturation magnetization and the parameter of uniaxial anisotropy. The two
+corresponding terms of laser-induced torque have different azimuthal
+symmetries, with the 4-fold symmetry of the demagnetization-related term, and
+the isotropic distribution of the anisotropy-related term. As a result, the
+initial phase and amplitude of excited magnetostatic waves have a non-trivial
+azimuthal distribution tunable with the angle between the external magnetic
+field and anisotropy axis, and the laser spot diameter. Moreover, the variation
+of these parameters tunes the distribution of wavevectors, resulting in
+additional asymmetry between the spectral components of the waves propagating
+in different directions.",2310.05895v1
+2023-10-10,Helically-trapped electron mode in optimized stellarator,"Global gyrokinetic simulations find a strong helically-trapped electron mode
+(HTEM) driven by density gradients in the optimized stellarator W7-X fusion
+experiment. The eigenmode structure localizes in the inner side of the torus
+with an unfavorable magnetic curvature and weak magnetic field, where there is
+a large fraction of helically-trapped electrons. The mode is excited mostly by
+the ion free energy and propagates in the ion direction with a linear frequency
+much smaller than the diamagnetic frequency. The instability saturates by
+nonlinear processes of turbulence spreading in the real space and spectral
+transfer from unstable to damped regions. The steady state HTEM turbulence
+drives a large particle flux that may have significant implications for the
+confinement of fusion fuel and removal of fusion ash in the stellarator
+reactor.",2310.06988v1
+2023-11-09,Squeezing Bose-Bose liquid drops,"We explore ultradilute Bose-Bose liquid droplets squeezed by an external
+harmonic potential in one spatial direction. Our theoretical study is based on
+a functional that is built using quantum Monte Carlo results of the bulk phase
+and incorporates finite-range effects. A characteristic feature of these drops
+is the existence of a critical atom number, that is the minimum number of
+particles to have a many-body bound state. We report results on the critical
+atom numbers for different magnetic fields and applying confinement strengths
+towards a quasi-two-dimensional setup. In the regime where the local density
+approximation is expected to be valid, we find that the critical atom number
+decreases linearly with the harmonic oscillator length of the confining
+potential. With the largest squeezing explored in our work, we predict stable
+drops at the level of one thousand atoms. Our functional reduces the critical
+numbers for any confinement and applied magnetic field with respect to the
+estimations based on the Lee-Huang-Yang model. We observe saturated drops when
+the number of atoms in the drop is much larger than the critical value, their
+central density being higher for the quantum Monte Carlo functional than for
+the Lee-Huang-Yang one.",2311.05244v1
+2023-11-23,Exciting high-frequency short-wavelength spin waves using high harmonics of a magnonic cavity mode,"Confined spin-wave modes are a promising object for studying nonlinear
+effects and future quantum technologies. Here, using micromagnetic simulations,
+we use a microwave magnetic field from a coplanar waveguide (CPW) to pump a
+standing spin-wave confined in the cavity of magnonic crystal. We find that the
+frequency of the fundamental cavity mode is equal to the ferromagnetic
+resonance frequency of the plane film and overlaps with the magnonic bandgap,
+allowing high magnetic field tunability. Multi-frequency harmonics of the
+cavity mode are generated once the microwave amplitude surpasses a certain
+threshold. Specifically, the second and third harmonics at 0.5 T equate to 48.6
+and 72.9 GHz with wavelengths of 44 and 22 nm respectively, which propagate
+into the crystal. This effect reaches saturation when the CPW covers the entire
+cavity, making the system feasible for realization. These processes show
+potential for the advancement of magnonics at high-frequencies and very
+short-wavelengths.",2311.14143v1
+2023-12-05,Miniaturized Double-Wing Delta-E Effect Sensors,"Magnetoelastic composites are integral elements of sensors and actuators
+utilizing magnetostriction for their functionality. Their sensitivity typically
+scales with the saturation magnetostriction and inversely with magnetic
+anisotropy. However, this makes the devices prone to minuscule residual
+anisotropic stress from the fabrication process, impairing their performance
+and reproducibility, hence limiting their suitability for arrays. This study
+presents a shadow mask deposition technology combined with a free-free
+magnetoelectric microresonator design intended to minimize residual stress and
+inhomogeneity in the magnetoelastic layer. Resonators are experimentally and
+theoretically analyzed regarding local stress anisotropy, magnetic anisotropy,
+and the {\Delta}E effect in several resonance modes. Further, the sensitivity
+is analyzed in the example of {\Delta}E-effect sensors. The results demonstrate
+a device-to-device variation of the resonance frequency < 0.2 % with
+sensitivities comparable with macroscopic {\Delta}E-effect sensors. The
+reproducibility is drastically improved over previous magnetoelastic device
+arrays. This development marks a step forward in the reproducibility and
+homogeneity of magnetoelastic resonators and contributes to the feasibility of
+large-scale, integrated sensor arrays.",2312.02903v1
+2024-01-26,Rotational evolution of young-to-old stars with data-driven three-dimensional wind models,"Solar-type stars form with a wide range of rotation rates. A wide range
+persists until a stellar age of 0.6 Gyr, after which solar-type stars exhibit
+Skumanich spin-down. Rotational evolution models incorporating polytropic
+stellar winds struggle to simultaneously reproduce these two regimes, namely
+the initially wide range and the Skumanich spin-down without imposing an
+a-priori cap on the wind mass-loss rate. We show that a three-dimensional wind
+model driven by Alfv\'en waves and observational data yields wind torques that
+agree with the observed age distribution of rotation rates. In our models of
+the Sun and twenty-seven open cluster stars aged from 0.04 to 0.6 Gyr that have
+observationally derived surface magnetic maps and rotation rates, we find
+evidence of exponential spin-down in young stars that are rapid rotators and
+Skumanich spin-down for slow rotators. The two spin-down regimes emerge
+naturally from our data-driven models. Our modelling suggests that the observed
+age distribution of stellar rotation rates arises as a consequence of magnetic
+field strength saturation in rapid rotators.",2401.14747v1
+2024-03-24,Axion-Polaritons in quark stars: a possible solution to the missing pulsar problem,"This paper proposes an alternative mechanism to solve the so-called missing
+pulsar problem, a standing paradox between the theoretical expectations about
+the number of pulsars that should exist in the galaxy center of the Milky Way
+and their absence in the observations. The mechanism is based on the
+transformation of incident $\gamma$ rays into hybridized modes, known as
+axion-polaritons, which can exist inside highly magnetized quark stars with a
+quark matter phase known as the magnetic dual chiral density wave phase. This
+phase, which is favored over several other dense matter phases candidates at
+densities a few times nuclear saturation density, has already passed several
+important astrophysical tests. In the proposed mechanism, the absence of young
+magnetars occurs because as electromagnetic waves inside the star can only
+propagate through the hybridized modes, incident photons coming from a
+$\gamma$-ray burst get transformed into massless and massive axion polaritons
+by the Primakoff effect. Once thermalized, the massive axion-polaritons can
+self-gravitate up to a situation where their total mass overpasses the
+Chandrasekhar limit for these bosons, producing a mini blackhole that collapses
+the star.",2403.17035v1
+2000-12-22,The Origin of the Magnetic Fields of the Universe: The Plasma Astrophysics of the Free Energy of the Universe,"(abridged) The interpretation of Faraday rotation measure maps of AGNs within
+galaxy clusters has revealed regions, $\sim 50-100$ kpc, that are populated
+with large, $\sim 30 \mu$ G magnetic fields. The magnetic energy of these
+coherent regions is $\sim 10^{59-60}$ ergs, and the total magnetic energy over
+the whole cluster ($\sim 1$ Mpc across) is expected to be even larger. A
+sequence of physical processes that are responsible for the production,
+redistribution and dissipation of these magnetic fields is proposed. These
+fields are associated with single AGNs within the cluster and therefore with
+all galaxies during their AGN phase, simply because only the central
+supermassive black holes ($\sim 10^8 M_{\odot}$) have an accessible energy,
+$\sim 10^{61}$ ergs. We propose an $\alpha-\Omega$ dynamo process in an
+accretion disk. The disk rotation naturally provides a large winding number,
+$\sim 10^{11}$ turns, sufficient to make both large gain and large flux. The
+helicity of the dynamo can be generated by the differential plume rotation
+derived from star-disk collisions. This helicity generation process has been
+demonstrated in the laboratory and the dynamo gain was simulated numerically. A
+liquid sodium analog of the dynamo is being built. Speculations are that the
+back reaction of the saturated dynamo will lead to the formation of a
+force-free magnetic helix, which will carry the energy and flux of the dynamo
+away from the accretion disk and redistribute the field within the clusters and
+galaxy walls. The magnetic reconnection of a small fraction of this energy
+logically is the source of the AGN luminosity, and the remainder of the field
+energy should then dominate the free energy of the present-day universe.",0012484v1
+2009-03-13,$^{63/65}$Cu- and $^{35/37}$Cl-NMR Studies of Triplet Localization in the Quantum Spin System NH$_4$CuCl$_3$,"$^{63/65}$Cu- and $^{35/37}$Cl-NMR experiments were performed to investigate
+triplet localization in the $S=1/2$ dimer compound NH$_4$CuCl$_3$, which shows
+magnetization plateaus at one-quarter and three-quarters of the saturation
+magnetization. In $^{63/65}$Cu-NMR experiments, signal from only the singlet Cu
+site was observed, because that from the triplet Cu site was invisible due to
+the strong spin fluctuation of onsite 3$d$-spins. We found that the temperature
+dependence of the shift of $^{63/65}$Cu-NMR spectra at the singlet Cu site
+deviated from that of macroscopic magnetization below T=6 K. This deviation is
+interpreted as the triplet localization in this system. From the
+$^{35/37}$Cl-NMR experiments at the 1/4-plateau phase, we found the two
+different temperature dependences of Cl-shift, namely the temperature
+dependence of one deviates below T=6 K from that of the macroscopic
+magnetization as observed in the $^{63/65}$Cu-NMR experiments, whereas the
+other corresponds well with that of the macroscopic magnetization in the entire
+experimental temperature region. We interpreted these dependences as reflecting
+the transferred hyperfine field at the Cl site located at a singlet site and at
+a triplet site, respectively. This result also indicates that the triplets are
+localized at low temperatures. $^{63/65}$Cu-NMR experiments performed at high
+magnetic fields between the one-quarter and three-quarters magnetization
+plateaus have revealed that the two differently oriented dimers in the unit
+cell are equally occupied by triplets, the fact of which limits the theoretical
+model on the periodic structure of the localized triplets.",0903.2312v2
+2010-12-21,Magnetocrystalline anisotropy and uniaxiality of MnAs/GaAs(100) films,"We present an investigation of the magnetic behavior of epitaxial MnAs films
+grown on GaAs(100). We address the dependence of the magnetic moment,
+ferromagnetic transition temperature ($T_c$) and magnetocrystalline anisotropy
+constants on epitaxial conditions. From thorough structural and magnetic
+investigations, our findings indicate a more complex relationship between
+strain and magnetic properties in MnAs films than a simple stretch/compression
+of the unit cell axes. While a small increase is seen in the anisotropy
+constants the enhancement of the magnetic moment at saturation is significant.
+X-ray magnetic circular dichroism results show a behavior of the spin- and
+orbital-moment which is consistent with a structural transition at $T_c$. In
+particular, we find that the ratio of the orbital to spin moment shows a marked
+increase in the coexistence region of the ferromagnetic $\alpha$- and
+paramagnetic $\beta$-phases, a result that is well in accord with the observed
+increase of the $c/a$-ratio in the same temperature region. The \textit{ab
+initio} density functional calculations reveal that the magnetic properties are
+more sensitive towards change in in-plane axis as compared to a change of the
+out-of-plane axis, which is explained by the analysis of band structures. The
+effects of electron correlation in MnAs using \textit{ab initio} dynamical mean
+field theory are also presented.",1012.4717v1
+2012-02-03,Dead zones as safe-havens for planetesimals: influence of disc mass and external magnetic field,"(Abridged) Planetesimals embedded in a protoplanetary disc are stirred by
+gravitational torques exerted by density fluctuations in the surrounding
+turbulence. In particular, planetesimals in a disc supporting fully developed
+magneto-rotational turbulence are readily excited to velocity dispersions above
+the threshold for catastrophic disruption, halting planet formation. We aim to
+examine the stirring of planetesimals lying instead in a magnetically-decoupled
+midplane dead zone, stirred only by spiral density waves propagating out of the
+disc's magnetically-coupled turbulent surface layers. We extend previous
+studies to include a wider range of disc models, and explore the effects of
+varying the disc column density and external magnetic field strength. [...] The
+strength of the stirring is found to be independent of the gas surface density,
+which is contrary to the increase with disc mass expected from a simple linear
+wave picture. The discrepancy arises from the shearing out of density waves as
+they propagate into the dead zone, resulting in density structures near the
+midplane that exert weaker stochastic torques on average. We provide a simple
+analytic fit to our numerically obtained torque amplitudes that accounts for
+this effect. The stirring on the other hand depends sensitively on the net
+vertical magnetic flux, up to a saturation level above which magnetic forces
+dominate in the turbulent layers. For the majority of our models, the
+equilibrium planetesimal velocity dispersions lie between the thresholds for
+disrupting strong and weak aggregates, suggesting that collision outcomes will
+depend on material properties. However, discs with relatively weak magnetic
+fields yield reduced stirring, and their dead zones provide safe-havens even
+for the weakest planetesimals against collisional destruction.",1202.0771v1
+2016-02-04,Magnetic anisotropy in the frustrated spin chain compound $β$-TeVO$_4$,"Isotropic and anisotropic magnetic behavior of the frustrated spin chain
+compound $\beta$-TeVO$_4$ is reported. Three magnetic transitions observed in
+zero magnetic field are tracked in fields applied along different
+crystallographic directions using magnetization, heat capacity, and
+magnetostriction measurements. Qualitatively different temperature-field
+diagrams are obtained below 10 T for the field applied along $a$ or $b$ and
+along $c$, respectively. In contrast, a nearly isotropic high-field phase
+emerges above 18 T and persists up to the saturation that occurs around 22.5 T.
+Upon cooling in low fields, the transitions at $T_{\rm N1}$ and $T_{\rm N2}$
+toward the spin-density-wave and stripe phases are of the second order, whereas
+the transition at $T_{\rm N3}$ toward the helical state is of the first order
+and entails a lattice component. Our microscopic analysis identifies frustrated
+$J_1-J_2$ spin chains with a sizable antiferromagnetic interchain coupling in
+the $bc$ plane and ferromagnetic couplings along the $a$ direction. The
+competition between these ferromagnetic interchain couplings and the helical
+order within the chain underlies the incommensurate order along the
+$a$-direction, as observed experimentally. Although a helical state is
+triggered by the competition between $J_1$ and $J_2$ within the chain, the
+plane of the helix is not uniquely defined because of competing magnetic
+anisotropies. Using high-resolution synchrotron diffraction and $^{125}$Te
+nuclear magnetic resonance, we also demonstrate that the crystal structure of
+$\beta$-TeVO$_4$ does not change down to 10 K, and the orbital state of
+V$^{4+}$ is preserved.",1602.01632v2
+2017-05-12,Spectral variability of photospheric radiation due to faculae I: The Sun and Sun-like stars,"Context. Stellar spectral variability on timescales of a day and longer,
+arising from magnetic surface features such as dark spots and bright faculae,
+is an important noise source when characterising extra-solar planets. Current
+1D models of faculae do not capture the geometric properties and fail to
+reproduce observed solar facular contrasts. Magnetoconvection simulations
+provide facular contrasts accounting for geometry. Aims. We calculate facular
+contrast spectra from magnetoconvection models of the solar photosphere with a
+view to improve (a) future parameter determinations for planets with early G
+type host stars and (b) reconstructions of solar spectral variability. Methods.
+Regions of a solar twin (G2, log g=4.44) atmosphere with a range of initial
+average vertical magnetic fields (100 to 500~G) were simulated using a 3D
+radiation-magnetohydrodynamics code, MURaM, and synthetic intensity spectra
+were calculated from the ultraviolet (149.5~nm) to the far infrared (160000~nm)
+with the ATLAS9 radiative transfer code. Nine viewing angles were investigated
+to account for facular positions across most of the stellar disc. Results.
+Contrasts of the radiation from simulation boxes with different levels of
+magnetic flux relative to an atmosphere with no magnetic field are a
+complicated function of position, wavelength and magnetic field strength that
+is not reproduced by 1D facular models. Generally, contrasts increase towards
+the limb, but at UV wavelengths a saturation and decrease are observed close to
+the limb. Contrasts also increase strongly from the visible to the UV; there is
+a rich spectral dependence, with marked peaks in molecular bands and strong
+spectral lines. At disc centre, a complex relationship with magnetic field was
+found and areas of strong magnetic field can appear either dark or bright,
+depending on wavelength...",1705.04455v1
+2017-11-14,"Growth, electrical, structural, and magnetic properties of half-Heusler CoTi$_{1-x}$Fe$_x$Sb","Epitaxial thin films of the substitutionally alloyed half-Heusler series
+CoTi$_{1-x}$Fe$_x$Sb were grown by molecular beam epitaxy on InAlAs/InP(001)
+substrates for concentrations 0.0$\leq$x$\leq$1.0. The influence of Fe on the
+structural, electronic, and magnetic properties was studied and compared to
+that expected from density functional theory. The films are epitaxial and
+single crystalline, as measured by reflection high-energy electron diffraction
+and X-ray diffraction. Using in-situ X-ray photoelectron spectroscopy, only
+small changes in the valence band are detected for x$\leq$0.5. For films with
+x$\geq$0.05, ferromagnetism is observed in SQUID magnetometry with a saturation
+magnetization that scales linearly with Fe content. A dramatic decrease in the
+magnetic moment per formula unit occurs when the Fe is substitutionally alloyed
+on the Co site indicating a strong dependence on the magnetic moment with site
+occupancy. A crossover from both in-plane and out-of-plane magnetic moments to
+only in-plane moment occurs for higher concentrations of Fe. Ferromagnetic
+resonance indicates a transition from weak to strong interaction with a
+reduction in inhomogeneous broadening as Fe content is increased.
+Temperature-dependent transport reveals a semiconductor to metal transition
+with thermally activated behavior for x$\leq$0.5. Anomalous Hall effect and
+large negative magnetoresistance (up to -18.5% at 100 kOe for x=0.3) are
+observed for higher Fe content films. Evidence of superparamagnetism for x=0.3
+and x=0.2 suggests for moderate levels of Fe, demixing of the
+CoTi$_{1-x}$Fe$_x$Sb films into Fe rich and Fe deficient regions may be
+present. Atom probe tomography is used to examine the Fe distribution in a
+x=0.3 film. Statistical analysis reveals a nonhomogeneous distribution of Fe
+atoms throughout the film, which is used to explain the observed magnetic and
+electrical behavior.",1711.05320v1
+2017-11-16,Pure phase BiFeO$_3$ thin films sputtered over Si: A new route towards high magnetization,"We have investigated the structural and magnetic properties of BiFeO$_3$
+(BFO) thin films grown over (100)-oriented Si substrates by rf magnetron
+sputtering in a new route under O$_2$ free low pressure Ar atmosphere.
+Single-phase BFO films were deposited in a heated substrate and post-annealed
+in situ. The new routed allows high deposition rate and produce polycrystalline
+BFO pure phase, confirmed by high resolution X-ray diffraction. Scanning
+electron and atomic force microscopy reveal very low surface roughness and mean
+particle size of 33 nm. The BFO phase and composition were confirmed by
+transmission electron microscopy and line scanning energy-dispersive X-ray
+spectroscopy in transmission electron microscopy mode. The surface chemistry of
+the thin film, analyzed by X-ray photoelectron spectroscopy, reveals the
+presence of Fe$^{3+}$ and Fe$^{2+}$ in a 2:1 ratio, a strong indication that
+the film contains oxygen vacancies. An hysteretic ferromagnetic behavior with
+room temperature high saturation magnetization $\sim 165 \times 10^3$ A/m was
+measured along the film perpendicular and parallel directions. Such high
+magnetization, deriving from this new route, is explained in the scope of
+oxygen vacancies, the break of the antiferromagnetic cycloidal order and the
+increase of spin canting by change in the surface/volume ratio. Understanding
+the magnetic behavior of a multiferroic thin films is a key for the development
+of heterogeneous layered structures and multilayered devices and the production
+of multiferroic materials over Si substrates opens new possibilities in the
+development of materials that can be directly integrated into the existent
+semiconductor and spintronic technologies.",1711.05873v3
+2018-02-22,Room Temperature Intrinsic Ferromagnetism in Epitaxial Manganese Selenide Films in the Monolayer Limit,"Monolayer van der Waals (vdW) magnets provide an exciting opportunity for
+exploring two-dimensional (2D) magnetism for scientific and technological
+advances, but the intrinsic ferromagnetism has only been observed at low
+temperatures. Here, we report the observation of room temperature
+ferromagnetism in manganese selenide (MnSe$_x$) films grown by molecular beam
+epitaxy (MBE). Magnetic and structural characterization provides strong
+evidence that in the monolayer limit, the ferromagnetism originates from a vdW
+manganese diselenide (MnSe$_2$) monolayer, while for thicker films it could
+originate from a combination of vdW MnSe$_2$ and/or interfacial magnetism of
+$\alpha$-MnSe(111). Magnetization measurements of monolayer MnSe$_x$ films on
+GaSe and SnSe$_2$ epilayers show ferromagnetic ordering with large saturation
+magnetization of ~ 4 Bohr magnetons per Mn, which is consistent with density
+functional theory calculations predicting ferromagnetism in monolayer
+1T-MnSe$_2$. Growing MnSe$_x$ films on GaSe up to high thickness (~ 40 nm)
+produces $\alpha$-MnSe(111), and an enhanced magnetic moment (~ 2x) compared to
+the monolayer MnSe$_x$ samples. Detailed structural characterization by
+scanning transmission electron microscopy (STEM), scanning tunneling microscopy
+(STM), and reflection high energy electron diffraction (RHEED) reveal an abrupt
+and clean interface between GaSe(0001) and $\alpha$-MnSe(111). In particular,
+the structure measured by STEM is consistent with the presence of a MnSe$_2$
+monolayer at the interface. These results hold promise for potential
+applications in energy efficient information storage and processing.",1802.08152v1
+2018-09-07,EPR measurements of Eu{+2} spins in metallic EuCo{2-y}As2 single crystals,"The Eu{+2} spins S = 7/2 in the metallic compound EuCo{2-y}As2 order into an
+antiferromagnetic helical structure below a Neel temperature TN = 40 to 45 K.
+The effective magnetic moment mu_eff of the Eu spins in the paramagnetic state
+from 100 to 300 K is found from static magnetic susceptibility measurements to
+be enhanced by about 7% compared to the value expected for spectroscopic
+splitting factor g = 2, and the saturation moment at high applied fields H and
+low temperatures T is also sometimes enhanced. Here
+electron-paramagnetic-resonance (CW EPR) measurements versus applied magnetic
+field H at fixed X-band rf (microwave) angular frequency omega were carried out
+using a linearly-polarized rf magnetic field oriented perpendicular to H to
+study the microscopic magnetic properties of the Eu spins. In order to analyze
+the data, the complex magnetic susceptibility chi(omega) at fixed H was used
+that was derived for linearly-polarized rf fields from the modified Bloch
+equations [M. A. Garstens and J. I. Kaplan, Phys. Rev. 99, 459 (1955)] (GK). It
+is shown that their formulation when applied to calculate the Dysonian
+absorptive susceptibility chi_D''(H) of local magnetic moments in metals yields
+a prediction that can be very different from the traditionally-used form of
+chi_D''(H). By fitting the derivative of the field-swept CW EPR data for
+EuCo{2-y}As2 by chi_D''(H) at fixed omega derived from the GK chi_D''(omega) at
+fixed H, the Eu spin spectroscopic splitting factor (g-factor) is found to be
+approximately 2.00 from 300 to ~125 K, and then to continuously increase to
+approximately 2.16 on further cooling to 50 K. We speculate that the
+enhancement of the Eu g-factor on cooling from 125 to 50 K arises from
+continuously-increasing local short-range ferromagnetic correlations between
+the Co 3d-band electrons and the Eu spins.",1809.02653v4
+2018-11-10,Non-Coplanar Model States in Quantum Magnetism Applications of the High-Order Coupled Cluster Method,"Coplanar model states for applications of the coupled cluster method (CCM) to
+problems in quantum magnetism are those in which all spins lie in a plane,
+whereas three-dimensional (3D) model states are, by contrast, non-coplanar ones
+in which all the spins do not lie in any single plane. Here we extend the CCM
+to non-coplanar / 3D model states and we present results for three cases: (a)
+the spin-half one-dimensional Ising ferromagnet in an applied transverse
+magnetic field (as an exactly solvable test model to use as a yardstick for the
+viability and accuracy of our new methodology); (b) the spin-half
+triangular-lattice Heisenberg antiferromagnet in the presence of an external
+magnetic field; and (c) the spin-$S$ triangular-lattice {\it XXZ}
+antiferromagnet in the presence of an external magnetic field, for the cases
+$\frac{1}{2} \leq S \leq5 $. For 3D model states the sets of algebraic CCM
+equations for the ket- and bra-state correlation coefficients become
+complex-valued, but ground-state expectation values of all physical observables
+are manifestly real numbers, as required. Excellent correspondence is seen with
+the results of other methods, where they exist, for these systems. CCM results
+demonstrate explicitly that coplanar ordering is favoured over non-coplanar
+ordering for the triangular-lattice spin-half Heisenberg antiferromagnet at all
+values of the applied external magnetic field, whereas for the anisotropic {\it
+XXZ} model non-coplanar ordering can be favoured in some regions of the
+parameter space. Specifically, we present a precise determination of the
+boundary (i.e., the critical value of the {\it XXZ} anisotropy parameter
+$\Delta$) between a 3D ground state and a coplanar ground state for the {\it
+XXZ} model for values for the external magnetic field near to saturation, for
+values of the spin quantum number $S \leq 5$.",1811.04228v1
+2019-03-13,Estimating magnetic filling factors from Zeeman-Doppler magnetograms,"Low-mass stars are known to have magnetic fields that are believed to be of
+dynamo origin. Two complementary techniques are principally used to
+characterise them. Zeeman-Doppler imaging (ZDI) can determine the geometry of
+the large-scale magnetic field while Zeeman broadening can assess the total
+unsigned flux including that associated with small-scale structures such as
+spots. In this work, we study a sample of stars that have been previously
+mapped with ZDI. We show that the average unsigned magnetic flux follows an
+activity-rotation relation separating into saturated and unsaturated regimes.
+We also compare the average photospheric magnetic flux recovered by ZDI,
+$\langle B_V\rangle$, with that recovered by Zeeman broadening studies,
+$\langle B_I\rangle$. In line with previous studies, $\langle B_V\rangle$
+ranges from a few % to $\sim$20% of $\langle B_I\rangle$. We show that a power
+law relationship between $\langle B_V\rangle$ and $\langle B_I\rangle$ exists
+and that ZDI recovers a larger fraction of the magnetic flux in more active
+stars. Using this relation, we improve on previous attempts to estimate filling
+factors, i.e. the fraction of the stellar surface covered with magnetic field,
+for stars mapped only with ZDI. Our estimated filling factors follow the
+well-known activity-rotation relation which is in agreement with filling
+factors obtained directly from Zeeman broadening studies. We discuss the
+possible implications of these results for flux tube expansion above the
+stellar surface and stellar wind models.",1903.05595v1
+2020-01-21,"Mechanical behavior, enhanced dc resistivity, energy band gap and high temperature magnetic properties of Y-substituted Mg-Zn ferrites","We report the synthesis of Y-substituted Mg-Zn ferrites using conventional
+standard ceramic technique. XRD patterns confirm the single phase cubic spinel
+structure up to x = 0.03 and appearance of a secondary phase of YFeO3for higher
+Y contents. FESEM images depict the distribution of grains and EDS spectra
+confirmed the absence of any unwanted element. Completion of solid state
+reaction and formation of spinel structure has been revealed from FTIR spectra.
+The FTIR data along with lattice constant, bulk density and porosity were
+further used to calculate the stiffness constant (Cij), elastic constant and
+Debye temperatures. Mechanical stability of all studied compositions is
+confirmed from Cij using Born stability conditions. Brittleness and isotropic
+nature are also confirmed using Poisson ratio and anisotropy constants,
+respectively. The enhancement of dc electrical resistivity with Y content is
+observed. The energy band gap (increased with Y contents) is found in good
+agreement with dc electrical resistivity. Ferrimagnetic to paramagnetic phase
+change has been observed from the field dependent high temperature
+magnetization curves. The magnetic moments and saturation magnetization were
+found to be decreased with increasing temperature. The Curie temperature (Tc)
+has been measured from temperature dependent magnetic moment (M-T) and initial
+permeability and found to be in good agreement with each other. Decrease in Tc
+with Y content is due to redistribution of cations and weakening of the
+exchange coupling constant. The magnetic phase transition has been analyzed by
+Arrott plot and found to have second order phase transition. The dc resistivity
+endorses the prepared ferrites are suitable for high frequency and high
+temperature magnetic device applications as well.",2001.07313v1
+2020-09-13,Mapping the magnetic state as a function of anti-site disorder in Sm$ _{2} $NiMnO$ _{6} $ double perovskite thin films,"The predictability of any characteristic functional aspect in a double
+perovskite system has always been compromised by its strong dependence over the
+inevitably present anti-site disorders (ASD). Here, we aim to precisely map the
+quantitative and qualitative nature of ASD with the corresponding modifications
+in observables describing the magnetic and electronic state in epitaxial Sm$
+_{2} $NiMnO$ _{6} $ (SNMO) double perovskite thin films. The concentration and
+distribution patterns of ASD are effectively controlled by optimizing growth
+conditions and estimated on both local and global scales utilizing extended
+X-ray absorption fine structure and bulk magnetometry. Depending upon the
+defect densities, the nature of disorder distribution can vary from homogeneous
+to partially segregated patches. Primarily, the effect of varying B-site
+cationic arrangement in SNMO is reflected as the competition of long range
+ferromagnetic (FM) and short scale antiferromagnetic (AFM) interactions
+originated from ordered Ni-O-Mn and disordered Ni-O-Ni or Mn-O-Mn bonds,
+respectively, which leads to systematic shift in magnetic transition
+temperature and drastic drop in saturation magnetization. In addition, we have
+observed that the gradual increment in density of ASD leads to significant
+deviation from uniaxial anisotropy character, reduction in anisotropy energy
+and enhancement of moment pinning efficiency. However, the observed signatures
+of $ Ni^{2+}+Mn^{4+} \longrightarrow Ni^{3+}+Mn^{3+} $ charge
+disproportionation is found to be independent of cation disorder densities.
+This work serves as a basic route-map to tune the characteristic magnetic
+anisotropy, magnetic phase transitions, and magnetization reversal mechanism by
+controlling ASD in a general double perovskite system.",2009.06020v3
+2021-03-14,Perpendicular magnetic anisotropy in ultra-thin Cu$_2$Sb-type (Mn-Cr)AlGe films onto thermally oxidized silicon substrates,"Perpendicularly magnetized films showing small saturation magnetization,
+$M_\mathrm{s}$, are essential for spin-transfer-torque writing type
+magnetoresistive random access memories, STT-MRAMs. An intermetallic compound,
+{(Mn-Cr)AlGe} of the Cu$_2$Sb-type crystal structure was investigated, in this
+study, as a material showing the low $M_\mathrm{s}$ ($\sim 300$ kA/m) and
+high-perpendicular magnetic anisotropy, $K_\mathrm{u}$. The layer thickness
+dependence of $K_\mathrm{u}$ and effects of Mg-insertion layers at top and
+bottom (Mn-Cr)AlGe$|$MgO interfaces were studied in film samples fabricated
+onto thermally oxidized silicon substrates to realize high-$K_\mathrm{u}$ in
+the thickness range of a few nanometer. Optimum Mg-insertion thicknesses were
+1.4 and 3.0 nm for the bottom and the top interfaces, respectively, which were
+relatively thick compared to results in similar insertion effect investigations
+on magnetic tunnel junctions reported in previous studies. The cross-sectional
+transmission electron microscope images revealed that the Mg-insertion layers
+acted as barriers to interdiffusion of Al-atoms as well as oxidization from the
+MgO layers. The values of $K_\mathrm{u}$ were about $7 \times 10^5$ and $2
+\times 10^5$ J/m$^3$ at room temperature for 5 and 3 nm-thick (Mn-Cr)AlGe
+films, respectively, with the optimum Mg-insertion thicknesses. The
+$K_\mathrm{u}$ at a few nanometer thicknesses is comparable or higher than
+those reported in perpendicularly magnetized CoFeB films which are
+conventionally used in MRAMs, while the $M_\mathrm{s}$ value is one third or
+less smaller than those of the CoFeB films. The developed (Mn-Cr)AlGe films are
+promising from the viewpoint of not only the magnetic properties, but also the
+compatibility to the silicon process in the film fabrication.",2103.07847v2
+2021-06-18,Magnetic field-induced non-trivial electronic topology in Fe3GeTe2,"The anomalous Hall, Nernst and thermal Hall coefficients of
+Fe$_{3-x}$GeTe$_2$ display several features upon cooling, like a reversal in
+the Nernst signal below $T = 50$ K pointing to a topological transition (TT)
+associated to the development of magnetic spin textures. Since the anomalous
+transport variables are related to the Berry curvature, a possible TT might
+imply deviations from the Wiedemann-Franz (WF) law. However, the anomalous Hall
+and thermal Hall coefficients of Fe$_{3-x}$GeTe$_2$ are found, within our
+experimental accuracy, to satisfy the WF law for magnetic-fields $\mu_0H$
+applied along its inter-layer direction. Surprisingly, large anomalous
+transport coefficients are also observed for $\mu_0H$ applied along the planar
+\emph{a}-axis as well as along the gradient of the chemical potential, a
+configuration that should not lead to their observation due to the absence of
+Lorentz force. However, as $\mu_0H$ $\|$ \emph{a}-axis is increased,
+magnetization and neutron scattering indicate just the progressive canting of
+the magnetic moments towards the planes followed by their saturation. These
+anomalous planar quantities are found to not scale with the component of the
+planar magnetization ($M_{\|}$), showing instead a sharp decrease beyond $\sim
+\mu_0 H_{\|} = $ 4 T which is the field required to align the magnetic moments
+along $\mu_0 H_{\|}$. We argue that locally chiral spin structures, such as
+skyrmions, and possibly skyrmion tubes, lead to a field dependent
+spin-chirality and hence to a novel type of topological anomalous transport.
+Locally chiral spin-structures are captured by our Monte-Carlo simulations
+incorporating small Dzyaloshinskii-Moriya and biquadratic exchange
+interactions.",2106.09861v2
+2021-12-15,Turbulent magnetic field amplification in binary neutron star mergers,"Magnetic fields are expected to play a key role in the dynamics and the
+ejection mechanisms that accompany the merger of two neutron stars. General
+relativistic magnetohydrodynamic (MHD) simulations offer a unique opportunity
+to unravel the details of the ongoing physical processes. Nevertheless, current
+numerical studies are severely limited by the fact that any affordable
+resolution remains insufficient to fully capture the small-scale dynamo,
+initially triggered by the Kelvin-Helmholtz instability, and later sourced by
+several MHD processes involving differential rotation. Here, we alleviate this
+limitation by using explicit large-eddy simulations, a technique where the
+unresolved dynamics occurring at the sub-grid scales (SGS) is modeled by extra
+terms, which are functions of the resolved fields and their derivatives. The
+combination of high-order numerical schemes, high resolutions, and the gradient
+SGS model allow us to capture the small-scale dynamos produced during the
+binary neutron star mergers. Here we follow the first 50 milliseconds after the
+merger and, for the first time, we find numerical convergence on the magnetic
+field amplification, in terms of integrated energy and spectral distribution
+over spatial scales. We also find that the average intensity of the magnetic
+field in the remnant saturates at $\sim 10^{16}$~G around $5$~ms after the
+merger. After $20-30$~ms, both toroidal and poloidal magnetic field components
+grow continuously, fed by the winding mechanism that provides a slow inverse
+cascade. We find no clear hints for magneto-rotational instabilities, and no
+significant impact of the magnetic field on the redistribution of angular
+momentum in the remnant in our simulations, probably due to the very turbulent
+and dynamical topology of the magnetic field at all stages, with small-scale
+components largely dominating over the large-scale ones.",2112.08413v2
+2022-02-16,"Spin Seebeck effect in iron oxide thin films: Effects of phase transition, phase coexistence, and surface magnetism","Understanding impacts of phase transition, phase coexistence, and surface
+magnetism on the longitudinal spin Seebeck effect (LSSE) in a magnetic system
+is essential to manipulate the spin to charge current conversion efficiency for
+spincaloritronic applications. We aim to elucidate these effects by performing
+a comprehensive study of the temperature dependence of LSSE in biphase iron
+oxide (BPIO = alpha-Fe2O3 + Fe3O4) thin films grown on Si (100) and Al2O3 (111)
+substrates. A combination of temperature-dependent anomalous Nernst effect
+(ANE) and electrical resistivity measurements show that the contribution of ANE
+from the BPIO layer is negligible compared to the intrinsic LSSE in the
+Si/BPIO/Pt heterostructure even at room temperature. Below the Verwey
+transition of the Fe3O4 phase, the total signal across BPIO/Pt is dominated by
+the LSSE. Noticeable changes in the intrinsic LSSE signal for both Si/BPIO/Pt
+and Al2O3/BPIO/Pt heterostructures around the Verwey transition of the Fe3O4
+phase and the antiferromagnetic (AFM) Morin transition of the alpha-Fe2O3 phase
+are observed. The LSSE signal for Si/BPIO/Pt is found to be almost two times
+greater than that for Al2O3/BPIO/Pt, an opposite trend is observed for the
+saturation magnetization though. Magnetic force microscopy reveals the higher
+density of surface magnetic moments of the Si/BPIO film compared to the
+Al2O3/BPIO film, which underscores a dominant role of interfacial magnetism on
+the LSSE signal and thereby explains the larger LSSE for Si/BPIO/Pt.",2202.07910v1
+2022-06-02,Magnetic dilution effect and topological phase transitions in (Mn$_{1-x}$Pb$_x$)Bi$_2$Te$_4$,"As the first intrinsic antiferromagnetic (AFM) topological insulator (TI),
+MnBi$_2$Te$_4$ has provided a material platform to realize various emergent
+phenomena arising from the interplay of magnetism and band topology. Here by
+investigating (Mn$_{1-x}$Pb$_x$)Bi$_2$Te$_4$ $(0\leq x \leq 0.82)$ single
+crystals via the x-ray, electrical transport, magnetometry and neutron
+measurements, chemical analysis, external pressure, and first-principles
+calculations, we reveal the magnetic dilution effect on the magnetism and band
+topology in MnBi$_2$Te$_4$. With increasing $x$, both lattice parameters $a$
+and $c$ expand linearly by around 2\%. All samples undergo the paramagnetic to
+A-type antiferromagnetic transition with the N$\acute{e}$el temperature
+decreasing lineally from 24 K at $x=0$ to 2 K at $x=0.82$. Our neutron data
+refinement of the $x=0.37$ sample indicates that the ordered moment is
+4.3(1)$\mu_B$/Mn at 4.85 K and the amount of the Mn$_{\rm{Bi}}$ antisites is
+negligible within the error bars. Isothermal magnetization data reveal a slight
+decrease of the interlayer plane-plane antiferromagnetic exchange interaction
+and a monotonic decrease of the magnetic anisotropy, due to diluting magnetic
+ions and enlarging the unit cell. For $x=0.37$, the application of external
+pressures enhances the interlayer antiferromagnetic coupling, boosting the
+N$\acute{e}$el temperature at a rate of 1.4 K/GPa and the saturation field at a
+rate of 1.8 T/GPa. Furthermore, our first-principles calculations reveal that
+the band inversion in the two end materials, MnBi$_2$Te$_4$ and PbBi$_2$Te$_4$,
+occurs at the $\Gamma$ and $Z$ point, respectively, while two gapless points
+appear at $x = $ 0.44 and $x = $ 0.66, suggesting possible topological phase
+transitions with doping.",2206.01324v1
+2022-10-07,"Magnetic induction processes in Hot Jupiters, application to KELT-9b","The small semi-major axes of Hot Jupiters lead to high atmospheric
+temperatures of up to several thousand Kelvin. Under these conditions,
+thermally ionised metals provide a rich source of charged particles and thus
+build up a sizeable electrical conductivity. Subsequent electromagnetic
+effects, such as the induction of electric currents, Ohmic heating, magnetic
+drag, or the weakening of zonal winds have thus far been considered mainly in
+the framework of a linear, steady-state model of induction. For Hot Jupiters
+with an equilibrium temperature $T_{eq} > 1500$ K, the induction of atmospheric
+magnetic fields is a runaway process that can only be stopped by non-linear
+feedback. For example, the back-reaction of the magnetic field onto the flow
+via the Lorentz force or the occurrence of magnetic instabilities. Moreover, we
+discuss the possibility of self-excited atmospheric dynamos. Our results
+suggest that the induced atmospheric magnetic fields and electric currents
+become independent of the electrical conductivity and the internal field, but
+instead are limited by the planetary rotation rate and wind speed. As an
+explicit example, we characterise the induction process for the hottest
+exoplanet, KELT-9b by calculating the electrical conductivity along atmospheric
+$P-T$-profiles for the day- and nightside. Despite the temperature varying
+between 3000 K and 4500 K, the resulting electrical conductivity attains an
+elevated value of roughly 1 S/m throughout the atmosphere. The induced magnetic
+fields are predominately horizontal and might reach up to a saturation field
+strength of 400 mT, exceeding the internal field by two orders of magnitude.",2210.03351v1
+2023-12-01,Magneto-transport in the monolayer MoS2 material system for high-performance field-effect transistor applications,"Electronic transport in monolayer MoS2 is significantly constrained by
+several extrinsic factors despite showing good prospects as a transistor
+channel material. Our paper aims to unveil the underlying mechanisms of the
+electrical and magneto-transport in monolayer MoS2. In order to quantitatively
+interpret the magneto-transport behavior of monolayer MoS2 on different
+substrate materials, identify the underlying bottlenecks, and provide
+guidelines for subsequent improvements, we present a deep analysis of the
+magneto-transport properties in the diffusive limit. Our calculations are
+performed on suspended monolayer MoS2 and MoS2 on different substrate materials
+taking into account remote impurity and the intrinsic and extrinsic phonon
+scattering mechanisms. We calculate the crucial transport parameters such as
+the Hall mobility, the conductivity tensor elements, the Hall factor, and the
+magnetoresistance over a wide range of temperatures, carrier concentrations,
+and magnetic fields. The Hall factor being a key quantity for calculating the
+carrier concentration and drift mobility, we show that for suspended monolayer
+MoS2 at room temperature, the Hall factor value is around 1.43 for magnetic
+fields ranging from 0.001 to 1 Tesla, which deviates significantly from the
+usual value of unity. In contrast, the Hall factor for various substrates
+approaches the ideal value of unity and remains stable in response to the
+magnetic field and temperature. We also show that the MoS2 over an Al2O3
+substrate is a good choice for the Hall effect detector. Moreover, the
+magnetoresistance increases with an increase in magnetic field strength for
+smaller magnetic fields before reaching saturation at higher magnetic fields.
+The presented theoretical model quantitatively captures the scaling of mobility
+and various magnetoresistance coefficients with temperature, carrier densities
+and magnetic fields.",2312.00378v1
+2011-07-15,The Expected Order of Saturated RNA Secondary Structures,"We show the expected order of RNA saturated secondary structures of size $n$
+is $\log_4n(1+O(\frac{\log_2n}{n}))$, if we select the saturated secondary
+structure uniformly at random. Furthermore, the order of saturated secondary
+structures is sharply concentrated around its mean. As a consequence saturated
+structures and structures in the traditional model behave the same with respect
+to the expected order. Thus we may conclude that the traditional model has
+already drawn the right picture and conclusions inferred from it with respect
+to the order (the overall shape) of a structure remain valid even if enforcing
+saturation (at least in expectation).",1107.3033v1
+2014-03-14,The Effect of Saturation on Belief Propagation Decoding of LDPC Codes,"We consider the effect of LLR saturation on belief propagation decoding of
+low-density parity-check codes. Saturation occurs universally in practice and
+is known to have a significant effect on error floor performance. Our focus is
+on threshold analysis and stability of density evolution.
+  We analyze the decoder for certain low-density parity-check code ensembles
+and show that belief propagation decoding generally degrades gracefully with
+saturation. Stability of density evolution is, on the other hand, rather
+strongly affected by saturation and the asymptotic qualitative effect of
+saturation is similar to reduction of variable node degree by one.",1403.3678v1
+2015-10-16,Looking for quark saturation in proton and nuclei,"The quark saturation behavior at low $Q^2$ is shown in a numeric solution of
+the DGLAP equation with parton recombination corrections, which resembles the
+widely discussed JIMWLK saturation of gluons. Our calculation suggests that the
+partonic saturation can be interpreted as a dynamical balance between the
+splitting and the fusion processes of partons, without any other condensation
+mechanisms added. The nuclear shadowing saturation at small $x$ resulted from
+the proposed quark saturation is also discussed.",1510.04787v2
+2023-12-22,Lipschitz saturation of complex algebraic varieties,"This paper is devoted to the study of Lipschitz Saturation of complex
+algebraic varieties. More precisely, we adapt classical results concerning the
+Lipschitz Saturation of analytic varieties to algebraic varieties using recent
+works about seminormalization and continuous rational functions. We investigate
+the concept of Lipschitz Saturation of a variety in another and we focus on the
+case where there is no finite morphism between the two varieties. This
+investigation leads us to answer, in the case of algebraic varieties, to an
+open question of Pham and Teissier concerning the finiteness of the Lipschitz
+Saturation of general algebras. Finally, we use the Lipschitz saturation to
+provide algebraic criteria for two algebraic varieties to be linked by a
+birational and locally biLipschitz homeomorphism.",2312.14517v1
+1999-08-29,Rigid aleph_epsilon-saturated models of superstable theories,"In a countable superstable NDOP theory, the existence of a rigid
+aleph_epsilon-saturated model implies the existence of 2^lambda rigid
+aleph_epsilon-saturated models of power lambda for every lambda>2^{aleph_0}.",9908158v1
+2009-04-30,Benchmark tests of slow light in saturable absorbers,"A series of benchmark tests of slow light in saturable absorbers is proposed.
+Stage I concerns experimental tests of saturable absorption, which can mimic
+slow light in saturable media. Stage II outlines the more demanding
+requirements for practical observation of spectral hole-burning in the
+absorption line, which is responsible for the reduction in group velocity.",0904.4780v1
+2011-08-19,On the existence of global saturation for spectral regularization methods with optimal qualification,"A family of real functions {g_\alpha} defining a spectral regularization
+method with optimal qualification is considered. Sufficient condition on the
+family and on the optimal qualification guaranteeing the existence of
+saturation are established. Appropriate characterizations of both the
+saturation function and the saturation set are found and some examples are
+provided.",1108.4072v1
+2014-09-30,Saturated free algebras revisited,"We give an exposition of results of Baldwin-Shelah on saturated free
+algebras, at the level of generality of complete first order theories $T$ with
+a saturated model $M$ which is in the algebraic closure of an indiscernible
+set. We then make some new observations when $M$ is a saturated free algebra,
+analogous to (more difficult) results for the free group, such as a description
+of forking.",1409.8604v1
+2015-10-09,Exact saturation in simple and NIP theories,"A theory $T$ is said to have exact saturation at a singular cardinal $\kappa$
+if it has a $\kappa$-saturated model which is not $\kappa^{+}$-saturated. We
+show, under some set-theoretic assumptions, that any simple theory has exact
+saturation. Also, an NIP theory has exact saturation if and only if it is not
+distal. This gives a new characterization of distality.",1510.02741v1
+2018-07-30,The saturation number of carbon nanocones and nanotubes,"The saturation number of a graph is the cardinality of a smallest maximal
+matching. This paper presents bounds for the saturation number of carbon
+nanocones which are asymptotically equal. The same techniques are applied for
+the saturation number of certain families of carbon nanotubes, which improve
+previous results and in one case, yields the exact value.",1807.11355v1
+2020-12-06,Saturation Numbers for Minors,"The saturation number $\text{sat}(n,\mathcal{F})$ is the minimum number of
+edges in any graph which does not contain a member of $\mathcal{F}$ as a
+subgraph, but will if any edge is added. We give a few upper and lower bounds
+for saturation numbers for minors. In particular, we shall show that certain
+Generalized Petersen Graphs are $K^r$-minor saturated for $6\le r\le 8$.",2012.03155v1
+2021-02-08,Reconstruction of Sparse Signals under Gaussian Noise and Saturation,"Most compressed sensing algorithms do not account for the effect of
+saturation in noisy compressed measurements, though saturation is an important
+consequence of the limited dynamic range of existing sensors. The few
+algorithms that handle saturation effects either simply discard saturated
+measurements, or impose additional constraints to ensure consistency of the
+estimated signal with the saturated measurements (based on a known saturation
+threshold) given uniform-bounded noise. In this paper, we instead propose a new
+data fidelity function which is directly based on ensuring a certain form of
+consistency between the signal and the saturated measurements, and can be
+expressed as the negative logarithm of a certain carefully designed likelihood
+function. Our estimator works even in the case of Gaussian noise (which is
+unbounded) in the measurements. We prove that our data fidelity function is
+convex. We moreover, show that it satisfies the condition of Restricted Strong
+Convexity and thereby derive an upper bound on the performance of the
+estimator. We also show that our technique experimentally yields results
+superior to the state of the art under a wide variety of experimental settings,
+for compressive signal recovery from noisy and saturated measurements.",2102.03975v1
+2021-05-17,Induction and Skolemization in saturation theorem proving,"We consider a typical integration of induction in saturation-based theorem
+provers and investigate the effects of Skolem symbols occurring in the
+induction formulas. In a practically relevant setting we establish a
+Skolem-free characterization of refutation in saturation-based proof systems
+with induction. Finally, we use this characterization to obtain unprovability
+results for a concrete saturation-based induction prover.",2105.07734v2
+2003-10-01,General Relativistic Magnetohydrodynamic Simulations of Collapsars,"We have performed 2.5-dimensional general relativistic magnetohydrodynamic
+(MHD) simulations of the gravitational collapse of a magnetized rotating
+massive star as a model of gamma ray bursts (GRBs). The current calculation
+focuses on general relativistic MHD with simplified microphysics (we ignore
+neutrino cooling, physical equation of state, and photodisintegration).
+Initially, we assume that the core collapse has failed in this star. A few
+$M_{\odot}$ black hole is inserted by hand into the calculation. The
+simulations presented in the paper follow the accretion of gas into a black
+hole that is assumed to have formed before the calculation begins.The
+simulation results show the formation of a disk-like structure and the
+generation of a jetlike outflow inside the shock wave launched at the core
+bounce. We have found that the jet is accelerated by the magnetic pressure and
+the centrifugal force and is collimated by the pinching force of the toroidal
+magnetic field amplified by the rotation and the effect of geometry of the
+poloidal magnetic field. The maximum velocity of the jet is mildly relativistic
+(0.3c). The velocity of the jet becomes larger as the initial rotational
+velocity of stellar matter gets faster. On the other hand, the dependence on
+the initial magnetic field strength is a bit more complicated: the velocity of
+the jet increases with the initial field strength in the weak field regime,
+then is saturated at some intermediate field strength, and decreases beyond the
+critical field strength. These results are related to the stored magnetic
+energy determined by the balance between the propagation time of the Alfven
+wave and the rotation time of the disk (or twisting time).",0310017v2
+2005-02-18,"The Magnetic Properties of an L Dwarf Derived from Simultaneous Radio, X-ray, and H-alpha Observations","We present the first simultaneous, multi-wavelength observations of an L
+dwarf, the L3.5 candidate brown dwarf 2MASS J00361617+1821104, conducted with
+the Very Large Array, the Chandra X-ray Observatory, and the Kitt Peak 4-m
+telescope. We detect strongly variable and periodic radio emission (P=3 hr)
+with a fraction of about 60% circular polarization. No X-ray emission is
+detected to a limit of L_X/L_{bol}<2e-5, several hundred times below the
+saturation level observed in early M dwarfs. Similarly, we do not detect
+H-alpha emission to a limit of L_{H-alpha}/L_{bol}<2e-7, the deepest for any L
+dwarf observed to date. The ratio of radio to X-ray luminosity is at least four
+orders of magnitude in excess of that observed in a wide range of active stars
+(including M dwarfs) providing the first direct confirmation that late-M and L
+dwarfs violate the radio/X-ray correlation. The radio emission is due to
+gyrosynchrotron radiation in a large-scale magnetic field of about 175 G, which
+is maintained on timescales longer than three years. The detected 3-hour period
+may be due to (i) the orbital motion of a companion at a separation of about
+five stellar radii, similar to the configuration of RS CVn systems, (ii) an
+equatorial rotation velocity of about 37 km/s and an anchored, long-lived
+magnetic field, or (iii) periodic release of magnetic stresses in the form of
+weak flares. In the case of orbital motion, the magnetic activity may be
+induced by the companion, possibly explaining the unusual pattern of activity
+and the long-lived signal. We conclude that fully convective stars can maintain
+a large-scale and stable magnetic field, but the lack of X-ray and H-alpha
+emission indicates that the atmospheric conditions are markedly different than
+in early-type stars and even M dwarfs. [abridged]",0502384v1
+2007-11-09,Magnetic field amplification in proto-neutron stars -- The role of the neutron-finger instability for dynamo excitation,"During the first 40 s after their birth, proto-neutron stars are expected to
+be subject to at least two types of instability: the convective instability and
+the neutron-finger one. Both instabilities involve convective motions and hence
+can trigger dynamo actions which may be responsible for the large magnetic
+fields in neutron stars and magnetars. We have solved the mean-field induction
+equation in a simplified one-dimensional model of both the convective and the
+neutron-finger instability zones. Although very idealized, the model includes
+the nonlinearities introduced by the feedback processes which tend to saturate
+the growth of the magnetic field (alpha-quenching) and suppress its turbulent
+diffusion (eta-quenching). The possibility of a dynamo action is studied within
+a dynamical model of turbulent diffusivity where the boundary of the unstable
+zone is allowed to move. We show that the dynamo action can be operative and
+that the amplification of the magnetic field can still be very effective.
+Furthermore, we confirm the existence of a critical spin-period, below which
+the dynamo is always excited independently of the degree of differential
+rotation, and whose value is related to the size of the neutron-finger
+instability zone. Finally we provide a relation for the intensity of the final
+field as a function of the spin of the star and of its differential rotation.
+Although they were obtained by using a toy model, we expect that our results
+are able to capture the qualitative and asymptotic behaviour of a mean-field
+dynamo action developing in the neutron-finger instability zone. Overall, we
+find that such a dynamo is very efficient in producing magnetic fields well
+above equipartition and thus that it could represent a possible explanation for
+the large surface magnetic fields observed in neutron stars.",0711.1498v3
+2011-11-23,Statistical analysis of the mass-to-flux ratio in turbulent cores: effects of magnetic field reversals and dynamo amplification,"We study the mass-to-flux ratio (M/\Phi) of clumps and cores in simulations
+of supersonic, magnetohydrodynamical turbulence for different initial magnetic
+field strengths. We investigate whether the (M/\Phi)-ratio of core and
+envelope, R = (M/\Phi)_{core}/(M/\Phi)_{envelope} can be used to distinguish
+between theories of ambipolar diffusion and turbulence-regulated star
+formation. We analyse R for different Lines-of-Sight (LoS) in various sub-cubes
+of our simulation box. We find that, 1) the average and median values of |R|
+for different times and initial magnetic field strengths are typically greater,
+but close to unity, 2) the average and median values of |R| saturate at average
+values of |R| ~ 1 for smaller magnetic fields, 3) values of |R| < 1 for small
+magnetic fields in the envelope are caused by field reversals when turbulence
+twists the field lines such that field components in different directions
+average out. Finally, we propose two mechanisms for generating values |R| ~< 1
+for the weak and strong magnetic field limit in the context of a turbulent
+model. First, in the weak field limit, the small-scale turbulent dynamo leads
+to a significantly increased flux in the core and we find |R| ~< 1. Second, in
+the strong field limit, field reversals in the envelope also lead to values |R|
+~< 1. These reversals are less likely to occur in the core region where the
+velocity field is more coherent and the internal velocity dispersion is
+typically subsonic.",1111.5539v2
+2014-05-09,Magnetic effects on the low-T/|W| instability in differentially rotating neutron stars,"Dynamical instabilities in protoneutron stars may produce gravitational waves
+whose observation could shed light on the physics of core-collapse supernovae.
+When born with sufficient differential rotation, these stars are susceptible to
+a shear instability (the ""low-T/|W| instability""), but such rotation can also
+amplify magnetic fields to strengths where they have a considerable impact on
+the dynamics of the stellar matter. Using a new magnetohydrodynamics module for
+the Spectral Einstein Code, we have simulated a differentially-rotating neutron
+star in full 3D to study the effects of magnetic fields on this instability.
+Though strong toroidal fields were predicted to suppress the low-T/|W|
+instability, we find that they do so only in a small range of field strengths.
+Below 4e13 G, poloidal seed fields do not wind up fast enough to have an effect
+before the instability saturates, while above 5e14 G, magnetic instabilities
+can actually amplify a global quadrupole mode (this threshold may be even lower
+in reality, as small-scale magnetic instabilities remain difficult to resolve
+numerically). Thus, the prospects for observing gravitational waves from such
+systems are not in fact diminished over most of the magnetic parameter space.
+  Additionally, we report that the detailed development of the low-T/|W|
+instability, including its growth rate, depends strongly on the particular
+numerical methods used. The high-order methods we employ suggest that growth
+might be considerably slower than found in some previous simulations.",1405.2144v1
+2014-06-18,Non-thermal Gamma-ray Emission from Delayed Pair Breakdown in a Magnetized and Photon-rich Outflow,"We consider delayed, volumetric heating in a magnetized outflow that has
+broken out of a confining medium and expanded to a high Lorentz factor ($\Gamma
+\sim 10^2-10^3$) and low optical depth to scattering ($\tau_{\rm T} \sim
+10^{-3}-10^{-2}$). The energy flux at breakout is dominated by the magnetic
+field, with a modest contribution from quasi-thermal gamma rays whose spectrum
+was calculated in Paper I. We focus on the case of extreme baryon depletion in
+the magnetized material, but allow for a separate baryonic component that is
+entrained from a confining medium. Dissipation is driven by relativistic motion
+between these two components, which develops once the photon compactness drops
+below $ 4\times 10^3(Y_e/0.5)^{-1}$. We first calculate the acceleration of the
+magnetized component following breakout, showing that embedded MHD turbulence
+provides significant inertia, the neglect of which leads to unrealistically
+high estimates of flow Lorentz factor. After re-heating begins, the pair and
+photon distributions are evolved self-consistently using a one-zone kinetic
+code that incorporates an exact treatment of Compton scattering, pair
+production and annihilation, and Coulomb scattering. Heating leads to a surge
+in pair creation, and the scattering depth saturates at $\tau_{\rm T} \sim$
+1-4. The plasma maintains a very low ratio of particle to magnetic pressure,
+and can support strong anisotropy in the charged particle distribution, with
+cooling dominated by Compton scattering. High-energy power-law spectra with
+photon indices in the range observed in GRBs ($-3 < \beta < -3/2$) are obtained
+by varying the ratio of heat input to the seed energy in quasi-thermal photons.
+We contrast our results with those for continuous heating across an expanding
+photosphere, and show that the latter model produces soft-hard evolution that
+is inconsistent with observations of GRBs.",1406.4774v1
+2015-08-03,Structural and ferromagnetic properties of an orthorhombic phase of MnBi stabilized with Rh additions,"The article addresses the possibility of alloy elements in MnBi which may
+modify the thermodynamic stability of the NiAs-type structure without
+significantly degrading the magnetic properties. The addition of small amounts
+of Rh and Mn provides an improvement in the thermal stability with some
+degradation of the magnetic properties. The small amounts of Rh and Mn
+additions in MnBi stabilize an orthorhombic phase whose structural and magnetic
+properties are closely related to the ones of the previously reported
+high-temperature phase of MnBi (HT~MnBi). To date, the properties of the
+HT~MnBi, which is stable between $613$ and $719$~K, have not been studied in
+detail because of its transformation to the stable low-temperature MnBi
+(LT~MnBi), making measurements near and below its Curie temperature difficult.
+The Rh-stabilized MnBi with chemical formula Mn$_{1.0625-x}$Rh$_{x}$Bi
+[$x=0.02(1)$] adopts a new superstructure of the NiAs/Ni$_2$In structure
+family. It is ferromagnetic below a Curie temperature of $416$~K. The critical
+exponents of the ferromagnetic transition are not of the mean-field type but
+are closer to those associated with the Ising model in three dimensions. The
+magnetic anisotropy is uniaxial; the anisotropy energy is rather large, and it
+does not increase when raising the temperature, contrary to what happens in
+LT~MnBi. The saturation magnetization is approximately $3$~$\mu_B$/f.u. at low
+temperatures. While this exact composition may not be application ready, it
+does show that alloying is a viable route to modifying the stability of this
+class of rare-earth-free magnet alloys.",1508.00473v1
+2015-09-09,The monoclinic crystal structure of $α$-RuCl$_3$ and the zigzag antiferromagnetic ground state,"The layered honeycomb magnet alpha-RuCl3 has been proposed as a candidate to
+realize a Kitaev spin model with strongly frustrated, bond-dependent,
+anisotropic interactions between spin-orbit entangled jeff=1/2 Ru4+ magnetic
+moments. Here we report a detailed study of the three-dimensional crystal
+structure using x-ray diffraction on untwinned crystals combined with
+structural relaxation calculations. We consider several models for the stacking
+of honeycomb layers and find evidence for a crystal structure with a monoclinic
+unit cell corresponding to a stacking of layers with a unidirectional in-plane
+offset, with occasional in-plane sliding stacking faults, in contrast with the
+currently-assumed trigonal 3-layer stacking periodicity. We report electronic
+band structure calculations for the monoclinic structure, which find support
+for the applicability of the jeff=1/2 picture once spin orbit coupling and
+electron correlations are included. We propose that differences in the
+magnitude of anisotropic exchange along symmetry inequivalent bonds in the
+monoclinic cell could provide a natural mechanism to explain the spin gap
+observed in powder inelastic neutron scattering, in contrast to spin models
+based on the three-fold symmetric trigonal structure, which predict a gapless
+spectrum within linear spin wave theory. Our susceptibility measurements on
+both powders and stacked crystals, as well as neutron powder diffraction show a
+single magnetic transition at TN ~ 13K. The analysis of the neutron data
+provides evidence for zigzag magnetic order in the honeycomb layers with an
+antiferromagnetic stacking between layers. Magnetization measurements on
+stacked single crystals in pulsed field up to 60T show a single transition
+around 8T for in-plane fields followed by a gradual, asymptotic approach to
+magnetization saturation, as characteristic of strongly anisotropic exchange
+interactions.",1509.02670v2
+2016-03-21,Magnetic Field Evolution in Giant Radio Relics using the example of CIZA J2242.8+5301,"Giant radio relics are the arc-shaped diffuse radio emission regions observed
+in the outskirts of some merging galaxy clusters. They are believed to trace
+shock-waves in the intra-cluster medium. Recent observations demonstrated that
+some prominent radio relics exhibit a steepening above 2 GHz in their radio
+spectrum. This challenges standard theoretical models because shock
+acceleration is expected to accelerate electrons to very high energies with a
+power-law distribution in momentum. In this work we attempt to reconcile these
+data with the shock-acceleration scenario. We propose that the spectral
+steepening may be caused by the highest energy electrons emitting
+preferentially in lower magnetic fields than the bulk of synchrotron bright
+electrons in relics. Here, we focus on a model with an increasing mag- netic
+field behind the shock front, which quickly saturates and then declines. We
+derive the time-evolution of cosmic-ray electron spectra in time variable
+magnetic fields and an expanding medium. We then apply the formalism on the
+large radio relic in the cluster CIZA J2242.8+5301 (the Sausage relic). We show
+that under favourable circumstances of magnetic field amplification downstream,
+our model can explain the observed radio spectrum, the brightness profile and
+the spectral index profile of the relic. A possible interpretation for the
+required amplification of the magnetic field downstream is a dynamo acting
+behind the shock with an injection scale of magnetic turbulence of about 10
+kpc. Our models require injection efficiencies of CRe - which are in tension
+with simple diffusive shock acceleration from the thermal pool. We show that
+this problem can likely be alleviated considering pre-existing CRe.",1603.06570v1
+2016-06-15,Modulated magnetism and anomalous electronic transport in $\rm Ce_3Cu_4As_4O_2$,"The complex magnetism and transport properties of tetragonal
+Ce$_3$Cu$_4$As$_4$O$_2$ were examined through neutron scattering and physical
+properties measurements on polycrystalline samples. The lamellar structure
+consists of alternating layers of $\rm CeCu_4As_4$ with a single square Ce
+lattice and oxygen-linked Ce bi-layer $\rm Ce_2O_2$. Extending along $\bf c$, a
+tube-like Fermi surface from DFT calculations points to a quasi-two-dimensional
+electronic system. Peaks in the specific heat at the Ne\'{e}l temperature
+$T_{N}=24$ $\rm K$, $T_{2}~=~16 $ $\rm K$ and $T_{3}~=~1.9$ $ \rm K$ indicate
+three magnetic phase transitions or distinct cross-over phenomena. For
+$T<T_{N}$ neutron diffraction indicates the development of ferromagnetic ab
+sheets for both Ce sites, with alternating polarization along $\bf{c}$, a wave
+vector ${\bf k}_{1}={\bf c}^*$. For $T<T_{2}$, quasi-two-dimensional low-energy
+spin fluctuations with ${\bf k}_{2}=\frac{1}{2}{\bf a}^*$ and polarized
+perpendicular to ${\bf k}_{2}$ are suppressed. The data are consistent with
+quasi-two-dimensional antiferromagnetic order in the $\rm CeCu_4As_4$ planes
+polarized along the ${\bf k}_{2}$ wave vector. $T_{3}$ marks a spin-flop
+transition where the ${\bf k}_{1}$ staggered magnetization switches to in-plane
+polarization. While the narrow 4f bands lie deep below the Fermi surface, there
+are significant transport anomalies associated with the transitions; in
+particular a substantial reduction in resistivity for $T<T_{N}$. At $T=100$ $
+\rm mK$ the ${\bf k}_1$ modulated staggered moment is $0.85~\mu_B$, which
+matches the $0.8~\mu_B$ saturation magnetization achieved for H $~=~7$ $ \rm T$
+at $T~=~2$ $ \rm K$. From low T Lorentzian fits the correlation length is in
+excess of 75 \AA. We argue the unusual sequence of magnetic transitions results
+from competing interactions and anisotropies for the two Ce sites.",1606.04937v1
+2016-11-02,The impact of magnetic fields on the chemical evolution of the supernova-driven ISM,"We present three-dimensional magneto-hydrodynamical simulations of the
+self-gravitating interstellar medium (ISM) in a periodic (256 pc)$^3$ box with
+a mean number density of 0.5 cm$^{-3}$. At a fixed supernova rate we
+investigate the multi-phase ISM structure, H$_{2}$ molecule formation and
+density-magnetic field scaling for varying initial magnetic field strengths (0,
+$6\times 10^{-3}$, 0.3, 3 $\mu$G). All magnetic runs saturate at mass weighted
+field strengths of $\sim$ 1 $-$ 3 $\mu$G but the ISM structure is notably
+different. With increasing initial field strengths (from $6\times 10^{-3}$ to 3
+$\mu$G) the simulations develop an ISM with a more homogeneous density and
+temperature structure, with increasing mass (from 5% to 85%) and volume filling
+fractions (from 4% to 85%) of warm (300 K $<$ T $<$ 8000 K) gas, with
+decreasing volume filling fractions (VFF) from $\sim$ 35% to $\sim$ 12% of hot
+gas (T $> 10^5$ K) and with a decreasing H$_{2}$ mass fraction (from 70% to $<$
+1%). Meanwhile the mass fraction of gas in which the magnetic pressure
+dominates over the thermal pressure increases by a factor of 10, from 0.07 for
+an initial field of $6\times 10^{-3}$ $\mu$G to 0.7 for a 3 $\mu$G initial
+field. In all but the simulations with the highest initial field strength
+self-gravity promotes the formation of dense gas and H$_{2}$, but does not
+change any other trends. We conclude that magnetic fields have a significant
+impact on the multi-phase, chemical and thermal structure of the ISM and
+discuss potential implications and limitations of the model.",1611.00585v1
+2017-05-31,The Evaporation and Survival of Cluster Galaxies' Coronae Part II: The Effectiveness of Anisotropic Thermal Conduction and Survival of Stripped Galactic Tails,"We simulate anisotropic thermal conduction between the intracluster medium
+(ICM) and the hot coronal interstellar medium (ISM) gas in cluster galaxies. In
+the earlier Paper I (Vijayaraghavan & Sarazin 2017a), we simulated the
+evaporation of the hot ISM due to isotropic (possibly saturated) conduction
+between the ISM and ICM. We found that hot coronae evaporate on $\sim 10^2$ Myr
+timescales, significantly shorter than the $\sim 10^3$ Myr gas loss times due
+to ram pressure stripping. No tails of stripped gas are formed. This is in
+tension with the observed ubiquity and implied longevity of compact X-ray
+coronae and stripped ISM tails, and requires the suppression of evaporation,
+possibly due to magnetic fields and anisotropic conduction. We perform a series
+of wind tunnel simulations similar to Paper I, now including ISM and ICM
+magnetic fields. We simulate the effect of anisotropic conduction for a range
+of extreme magnetic field configurations: parallel and perpendicular to the ICM
+wind, and continuous and completely disjoint between the ISM and ICM. We find
+that when conduction is anisotropic, gas loss due to evaporation is severely
+reduced; the overall gas loss rates with and without anisotropic conduction do
+not differ by more than $10 - 20\%$. Magnetic fields also prevent stripped
+tails from evaporating in the ICM by shielding, and providing few pathways for
+heat transport between the ICM and ISM. The morphology of stripped tails and
+magnetic fields in the tails and wakes of galaxies are sensitive to the initial
+magnetic field configuration.",1706.00021v2
+2017-08-21,Comment on `Oxygen vacancy-induced magnetic moment in edge-sharing CuO$_{2}$ chains of Li$_{2}$CuO$_{2}$',"In a recent work devoted to the magnetism of Li$_{2}$CuO$_{2}$, Shu et al.
+[New J. Phys. 19 (2017) 023026] have proposed a ""simplified"" unfrustrated
+microscopic model that differs considerably from the models refined through
+decades of prior work. We show that the proposed model is at odds with known
+experimental data, including the reported magnetic susceptibility $\chi(T)$
+data up to 550~K. Using an 8$^{\rm th}$ order high-temperature expansion for
+$\chi(T)$, we show that the experimental data for Li$_{2}$CuO$_{2}$ are
+consistent with the prior model derived from inelastic neutron scattering (INS)
+studies. We also establish the $T$-range of validity for a Curie-Weiss law for
+the real frustrated magnetic system. We argue that the knowledge of the
+long-range ordered magnetic structure for $T<T_N$ and of $\chi(T)$ in a
+restricted $T$-range provides insufficient information to extract all of the
+relevant couplings in frustrated magnets; the saturation field and INS data
+must also be used to determine several exchange couplings, including the weak
+but decisive frustrating antiferromagnetic (AFM) interchain couplings.",1708.06335v2
+2018-05-12,Coexistence of magnetic fluctuations and long-range orders in the one-dimensional $J_1-J_2$ zigzag chains materials BaDy$_2$O$_4$ and BaHo$_2$O$_4$,"The compounds BaDy$_2$O$_4$ and BaHo$_2$O$_4$ are part of a family of
+frustrated systems exhibiting interesting properties, including spin
+liquid-type ground states, magnetic field-induced phases, and the coexistence
+of short- and long-range magnetic orders, with dominant one-dimensional
+correlations, which can be described as Ising $J_1-J_2$ zigzag chains along the
+$c$-axis. We have investigated polycrystalline samples of BaDy$_2$O$_4$ and
+BaHo$_2$O$_4$ with both neutron diffraction and neutron spectroscopy, coupled
+to detailed crystalline electric field calculations. The latter points to
+site-dependent anisotropic magnetism in both materials, which is corroborated
+by the magnetic structures we determined. The two systems show the coexistence
+of two different long-range orders --- two double N\'eel
+$\uparrow\uparrow\downarrow\downarrow$ orders in the $ab$-plane with
+propagation vectors $\mathbf{k}_1$ = ($\frac{1}{2}$,0,$\frac{1}{2}$) and
+$\mathbf{k}_2$ = ($\frac{1}{2}$,$\frac{1}{2}$,$\frac{1}{2}$) for BaDy$_2$O$_4$,
+and two distinct arrangements of simple N\'eel
+$\uparrow\downarrow\uparrow\downarrow$ orders along the $c$-axis, both with the
+propagation vector $\mathbf{k}_0$ = (0,0,0) for BaHo$_2$O$_4$. The order for
+both wave vectors in BaDy$_2$O$_4$ occurs at $T_\mathrm{N}$ = 0.48 K, while in
+BaHo$_2$O$_4$, the first order sets in at $T_\mathrm{N}\sim$ 1.3 K and the
+second one has a lower ordering temperature of 0.84 K. Both compounds show
+extensive diffuse scattering which we successfully modeled with a
+one-dimensional axial next-nearest neighbor Ising (ANNNI) model. In both
+materials, strong diffusive scattering persists to temperatures well below
+where the magnetic order is fully saturated. The ANNNI model fits indicate the
+presence of sites which do not order with moments in the $ab$-plane.",1805.04694v1
+2019-03-19,Magnetic properties and domain structure of ultrathin yttrium iron garnet/Pt bilayers,"We report on the structure, magnetization, magnetic anisotropy, and domain
+morphology of ultrathin yttrium iron garnet (YIG)/Pt films with thickness
+ranging from 3 to 90 nm. We find that the saturation magnetization is close to
+the bulk value in the thickest films and decreases towards low thickness with a
+strong reduction below 10 nm. We characterize the magnetic anisotropy by
+measuring the transverse spin Hall magnetoresistance as a function of applied
+field. Our results reveal strong easy plane anisotropy fields of the order of
+50-100 mT, which add to the demagnetizing field, as well as weaker in-plane
+uniaxial anisotropy ranging from 10 to 100 $\mu$T. The in-plane easy axis
+direction changes with thickness, but presents also significant fluctuations
+among samples with the same thickness grown on the same substrate. X-ray
+photoelectron emission microscopy reveals the formation of zigzag magnetic
+domains in YIG films thicker than 10 nm, which have dimensions larger than
+several 100 $\mu$m and are separated by achiral N\'{e}el-type domain walls.
+Smaller domains characterized by interspersed elongated features are found in
+YIG films thinner than 10 nm.",1903.08285v1
+2019-04-23,First 100 ms of a long-lived magnetized neutron star formed in a binary neutron star merger,"The recent multimessenger observation of the short gamma-ray burst (SGRB) GRB
+170817A together with the gravitational wave (GW) event GW170817 provides
+evidence for the long-standing hypothesis associating SGRBs with binary neutron
+star (BNS) mergers. The nature of the remnant object powering the SGRB, which
+could have been either an accreting black hole (BH) or a long-lived magnetized
+neutron star (NS), is, however, still uncertain. General relativistic
+magnetohydrodynamic (GRMHD) simulations of the merger process represent a
+powerful tool to unravel the jet launching mechanism, but so far most
+simulations focused the attention on a BH as the central engine, while the
+long-lived NS scenario remains poorly investigated. Here, we explore the latter
+by performing a GRMHD BNS merger simulation extending up to ~100 ms after
+merger, much longer than any previous simulation of this kind. This allows us
+to (i) study the emerging structure and amplification of the magnetic field and
+observe a clear saturation at magnetic energy $E_\mathrm{mag} \sim 10^{51}$
+erg, (ii) follow the magnetically supported expansion of the outer layers of
+the remnant NS and its evolution into an ellipsoidal shape without any
+surrounding torus, and (iii) monitor density, magnetization, and velocity along
+the axis, observing no signs of jet formation. We also argue that the
+conditions at the end of the simulation disfavor later jet formation on
+subsecond timescales if no BH is formed. Furthermore, we examine the rotation
+profile of the remnant, the conversion of rotational energy associated with
+differential rotation, the overall energy budget of the system, and the
+evolution of the GW frequency spectrum. Finally, we perform an additional
+simulation where we induce the collapse to a BH ~70 ms after merger, in order
+to gain insights on the prospects for massive accretion tori in case of a late
+collapse. We find that...",1904.10222v2
+2019-06-27,The low-frequency break observed in the slow solar wind magnetic spectra,"Fluctuations of solar wind magnetic field and plasma parameters exhibit a
+typical turbulence power spectrum with a spectral index ranging between $\sim
+-5/3$ and $\sim -3/2$. In particular, at $1$ AU, the magnetic field spectrum,
+observed within fast corotating streams, also shows a clear steepening for
+frequencies higher than the typical proton scales, of the order of $\sim
+3\times10^{-1}$ Hz, and a flattening towards $1/f$ at frequencies lower than
+$\sim 10^{-3}$ Hz. However, the current literature reports observations of the
+low-frequency break only for fast streams. Slow streams, as observed to date,
+have not shown a clear break, and this has commonly been attributed to slow
+wind intervals not being long enough. Actually, because of the longer transit
+time from the Sun, slow wind turbulence would be older and the frequency break
+would be shifted to lower frequencies with respect to fast wind. Based on this
+hypothesis, we performed a careful search for long-lasting slow wind intervals
+throughout $12$ years of Wind satellite measurements. Our search, based on
+stringent requirements not only on wind speed but also on the level of magnetic
+compressibility and Alfv\'enicity of the turbulent fluctuations, yielded $48$
+slow wind streams lasting longer than $7$ days. This result allowed us to
+extend our study to frequencies sufficiently low and, for the first time in the
+literature, we are able to show that the $1/f$ magnetic spectral scaling is
+also present in the slow solar wind, provided the interval is long enough.
+However, this is not the case for the slow wind velocity spectrum, which keeps
+the typical Kolmogorov scaling throughout the analysed frequency range. After
+ruling out the possible role of compressibility and Alfv\'enicity for the 1/f
+scaling, a possible explanation in terms of magnetic amplitude saturation, as
+recently proposed in the literature, is suggested.",1906.11767v1
+2019-06-29,Terahertz Faraday and Kerr rotation spectroscopy of Bi$_{1-x}$Sb$_x$ films in high magnetic fields up to 30 Tesla,"We report results of terahertz Faraday and Kerr rotation spectroscopy
+measurements on thin films of $\text{Bi}_{1-x}\text{Sb}_{x}$, an alloy system
+that exhibits a semimetal-to-topological-insulator transition as the Sb
+composition $x$ increases. By using a single-shot time-domain terahertz
+spectroscopy setup combined with a table-top pulsed mini-coil magnet, we
+conducted measurements in magnetic fields up to 30~T, observing distinctly
+different behaviors between semimetallic ($x < 0.07$) and topological insulator
+($x > 0.07$) samples. Faraday and Kerr rotation spectra for the semimetallic
+films showed a pronounced dip that blue-shifted with the magnetic field,
+whereas spectra for the topological insulator films were positive and
+featureless, increasing in amplitude with increasing magnetic field and
+eventually saturating at high fields ($>$20~T). Ellipticity spectra for the
+semimetallic films showed resonances, whereas the topological insulator films
+showed no detectable ellipticity. To explain these observations, we developed a
+theoretical model based on realistic band parameters and the Kubo formula for
+calculating the optical conductivity of Landau-quantized charge carriers. Our
+calculations quantitatively reproduced all experimental features, establishing
+that the Faraday and Kerr signals in the semimetallic films predominantly arise
+from bulk hole cyclotron resonances while the signals in the topological
+insulator films represent combined effects of surface carriers originating from
+multiple electron and hole pockets. These results demonstrate that the use of
+high magnetic fields in terahertz magnetopolarimetry, combined with detailed
+electronic structure and conductivity calculations, allows us to unambiguously
+identify and quantitatively determine unique contributions from different
+species of carriers of topological and nontopological nature in
+Bi$_{1-x}$Sb$_x$.",1907.00137v1
+2020-05-19,The benefits of a Bayesian analysis for the characterization of magnetic nanoparticles,"Magnetic nanoparticles offer a unique potential for various biomedical
+applications, but prior to commercial usage a standardized characterization of
+their structural and magnetic properties is required. For a thorough
+characterization, the combination of conventional magnetometry and advanced
+scattering techniques has shown great potential. In the present work, we
+characterize a powder sample of high-quality iron oxide nanoparticles that are
+surrounded with a homogeneous thick silica shell by DC magnetometry and
+magnetic small-angle neutron scattering (SANS). To retrieve the particle
+parameters such as their size distribution and saturation magnetization from
+the data, we apply standard model fits of individual data sets as well as
+global fits of multiple curves, including a combination of the magnetometry and
+SANS measurements. We show that by combining a standard least-squares fit with
+a subsequent Bayesian approach for the data refinement, the probability
+distributions of the model parameters and their cross correlations can be
+readily extracted, which enables a direct visual feedback regarding the quality
+of the fit. This prevents an overfitting of data in case of highly correlated
+parameters and renders the Bayesian method as an ideal component for a
+standardized data analysis of magnetic nanoparticle samples.",2005.09325v3
+2020-08-02,Chiral properties of (2+1)-flavor QCD in strong magnetic fields at zero temperature,"We present lattice QCD results for masses and magnetic polarizabilities of
+light and strange pseudoscalar mesons, chiral condensates, decay constants of
+neutral pion, and neutral kaon in the presence of background magnetic fields
+with $eB$ ranging up to around 3.35 GeV$^2$ ($\sim70~M_\pi^2$) in the vacuum.
+The computations were carried out in (2+1)-flavor QCD mostly on $32^3 \times
+96$ lattices using the highly improved staggered quark action with $M_{\pi}
+\approx $ 220 MeV at zero temperature. We find that the masses of neutral
+pseudoscalar mesons monotonously decrease as the magnetic field strength grows
+and then saturate at a nonzero value, while there exists a nonmonotonous
+behavior of charged pion and kaon masses in the magnetic field. We observe a
+$qB$ scaling of the up and down quark flavor components of neutral pion mass,
+neutral pion decay constant as well as the quark chiral condensates at 0.05
+$\lesssim eB\lesssim$ 3.35 GeV$^2$. We show that the correction to the
+Gell-Mann-Oakes-Renner relation involving the neutral pion is less than 6% and
+the correction for the relation involving neutral kaon is less than 30% at
+$eB\lesssim$ 3.35 GeV$^2$. We also derive the Ward-Takahashi identities for QCD
+in the magnetic field in the continuum formulation including the relation
+between integrated neutral pseudoscalar meson correlators and chiral
+condensates.",2008.00493v4
+2021-05-24,Spin Canting in Exchange Coupled Bi-Magnetic Nanoparticles: Interfacial Effects and Hard / Soft Layer Ordering,"We investigate the spatial distribution of spin orientation in magnetic
+nanoparticles consisting of hard and soft magnetic layers. The nanoparticles
+are synthesized in a core / shell spherical morphology where the magnetically
+hard, high anisotropy layer is CoFe$_2$O$_4$ (CFO) while the lower anisotropy
+material is Fe$_3$O$_4$ (FO). The nanoparticles have a mean diameter of
+$\sim$9.2 - 9.6 nm and are synthesized as two variants: a conventional hard /
+soft core / shell structure with a CFO core / FO shell (CFO@FO) and the
+inverted structure FO core / CFO shell (FO@CFO). High resolution electron
+microscopy confirms the coherent spinel structure across the core / shell
+boundary in both variants while magnetometry indicates the nanoparticles are
+superparamagnetic at 300 K and develop a considerable anisotropy at reduced
+temperatures. Low temperature \textit{M vs. H} loops suggest a multi-step
+reversal process. Temperature dependent small angle neutron scattering (SANS)
+with full polarization analysis reveals a strong perpendicular plane alignment
+of the spins near zero field, indicative of spin canting, but the perpendicular
+alignment quickly disappears upon application of a weak field and little spin
+ordering parallel to the field until the coercive field is reached. Above the
+coercive field of the sample, spins orient predominantly along the field
+direction. At both zero field and near saturation, the parallel magnetic SANS
+peak coincides with the structural peak, indicating the magnetization is
+uniform throughout the nanoparticle volume, while near the coercive field the
+parallel scattering peak shifts to higher momentum transfer (Q), suggesting
+that the coherent scattering volume is smaller and likely originates in the
+softer Fe$_3$O$_4$ portion of the nanoparticle.",2105.11501v1
+2022-01-10,Formation of Magnetically Truncated Accretion Disks in 3D Radiation-Transport Two-Temperature GRMHD Simulations,"Multi-wavelength observations suggest that the accretion disk in the hard and
+intermediate states of X-ray binaries (XRBs) and active galactic nuclei (AGN)
+transitions from a cold, thin disk at large distances into a hot, thick flow
+close to the black hole. However, the formation, structure and dynamics of such
+truncated disks are poorly constrained due to the complexity of the
+thermodynamic, magnetic, and radiative processes involved. We present the first
+radiation-transport two-temperature general relativistic magnetohydrodynamic
+(GRMHD) simulations of truncated disks radiating at ~35% of the Eddington
+luminosity with and without large-scale poloidal magnetic flux. We demonstrate
+that when a geometrically-thin accretion disk is threaded by large-scale net
+poloidal magnetic flux, it self-consistently transitions at small radii into a
+two-phase medium of cold gas clumps floating through a hot, magnetically
+dominated corona. This transition occurs at a well-defined truncation radius
+determined by the distance out to which the disk is saturated with magnetic
+flux. The average ion and electron temperatures in the semi-opaque corona
+reach, respectively, T_i ~ 10^10K and T_e ~ 5 10^8K. The system produces
+radiation, powerful collimated jets and broader winds at the total energy
+efficiency exceeding ~90%, the highest ever energy extraction efficiency from a
+spinning black hole by a radiatively efficient flow in a GRMHD simulation. This
+is consistent with jetted ejections observed during XRB outbursts. The
+two-phase medium may naturally lead to broadened iron line emission observed in
+the hard state.",2201.03526v3
+2022-06-08,Gravitoturbulent dynamo in global simulations of gaseous disks,"The turbulence driven by gravitational instabilities (GIs) can amplify
+magnetic fields in massive gaseous disks. This GI dynamo may appear in young
+circumstellar disks, whose weak ionization challenges other amplification
+routes, as well as in active galactic nuclei. Although regarded as a
+large-scale dynamo, only local simulations have so far described its kinematic
+regime. We study the GI dynamo in global magnetohydrodynamic (MHD) models of
+accretion disks, focusing on its kinematic phase. We perform resistive MHD
+simulations with the Pluto code for different radiative cooling times and
+electrical resistivities. A weak magnetic field seeds the dynamo, and we adopt
+mean-field and heuristic models to capture its essence. We recover the same
+induction process leading to magnetic field amplification as previously
+identified in local simulations. The dynamo is, however, global in nature,
+connecting distant annuli of the disk via a large-scale dynamo mode of a fixed
+growth rate. This large-scale amplification can be described by a mean-field
+model that does not rely on conventional alpha-Omega effects. When varying the
+disk parameters we find an optimal resistivity that facilitates magnetic
+amplification, whose magnetic Reynolds number, Rm < 10, is substantially
+smaller than in local simulations. Unlike local simulations, we find an optimal
+cooling rate and the existence of global oscillating dynamo modes. The
+nonlinear saturation of the dynamo puts the disk in a strongly magnetized
+turbulent state on the margins of the effective range of GI. In our
+simulations, the accretion power eventually exceeds the threshold required by
+local thermal balance against cooling, leaving the long-term nonlinear outcome
+of the GI dynamo uncertain.",2206.03917v2
+2008-11-11,Semi-global simulations of the magneto-rotational instability in core collapse supernovae,"Possible effects of magnetic fields in core collapse supernovae rely on an
+efficient amplification of the weak pre-collapse fields. It has been suggested
+that the magneto-rotational instability (MRI) leads to rapid field growth.
+Although MRI studies exist for accretion discs, the application of their
+results to core collapse supernovae is inhibited as the physics of supernova
+cores is substantially different from that of accretion discs. We address the
+problem of growth and saturation of the MRI by means of semi-global
+simulations, which combine elements of global and local simulations by taking
+the presence of global background gradients into account and using a local
+computational grid. We analyze the dispersion relation of the MRI to identify
+different regimes of the instability. This analysis is complemented by
+simulations, where we consider a local computational box rotating at
+sub-Keplerian velocity, and where we allow for a radial entropy gradient. We
+identify six regimes of the MRI depending on the ratio of the entropy and
+angular velocity gradient. Our numerical models confirm the instability
+criteria and growth rates for all relevant regimes. The MRI grows exponentially
+within milliseconds the flow and magnetic field geometries being dominated by
+channel flows. The MRI growth ceases once the channels are disrupted by
+resistive instabilities (due to finite numerical conductivity), and MHD
+turbulence sets in. From an analysis of the growth rates of the resistive
+instabilities, we deduce scaling laws for the termination amplitude of the MRI
+which agree well with our numerical models. We determine the dependence of the
+development of coherent flow structures in the saturated state on the aspect
+ratio of the simulation boxes. [abridged]",0811.1652v2
+2011-11-29,Oscillatory large-scale dynamos from Cartesian convection simulations,"We present results from compressible Cartesian convection simulations with
+and without imposed shear. In the former case the dynamo is expected to be of
+$\alpha^2\varOmega$ type which is generally expected to be relevant for the
+Sun, whereas the latter case refers to $\alpha^2$ dynamos which are more likely
+to occur in more rapidly rotating stars whose differential rotation is small.
+We perform a parameter study where the shear flow and the rotational influence
+are varied to probe the relative importance of both types of dynamos.
+Oscillatory solutions are preferred both in the kinematic and saturated regimes
+when the negative ratio of shear to rotation rates, $q\equiv -S/\varOmega$, is
+between 1.5 and 2, i.e., when shear and rotation are of comparable strengths.
+Other regions of oscillatory solutions are found with small values of $q$,
+i.e., when shear is weak in comparison to rotation, and in the regime of large
+negative $q$s, when shear is very strong in comparison to rotation. However,
+exceptions to these rules also appear so that for a given ratio of shear to
+rotation, solutions are non-oscillatory for small and large shear, but
+oscillatory in the intermediate range. Changing the boundary conditions from
+vertical field to perfect conductor ones changes the dynamo mode from
+oscillatory to quasi-steady. Furthermore, in many cases an oscillatory solution
+exists only in the kinematic regime whereas in the nonlinear stage the mean
+fields are stationary. However, the cases with rotation and no shear are always
+oscillatory in the parameter range studied here and the dynamo mode does not
+depend on the magnetic boundary conditions. The strengths of total and
+large-scale components of the magnetic field in the saturated state, however,
+are sensitive to the chosen boundary conditions.",1111.6894v2
+2013-02-26,Inverse Z-spectrum analysis for MT- and spillover-corrected and T1-compensated steady-state pulsed CEST-MRI - application to pH-weighted MRI of acute stroke,"Endogenous chemical exchange saturation transfer (CEST) effects are always
+diluted by competing effects such as direct water proton saturation (spillover)
+and macromolecular magnetization transfer (MT). This leads to T2-and
+MT-shine-through effects in the actual biochemical contrast of CEST. Therefore,
+a simple evaluation algorithm which corrects the CEST signal was searched for.
+By employing a recent eigenspace theory valid for spinlock and continuous wave
+(cw) CEST we predict that the inverse Z-spectrum is beneficial to Z-spectrum
+itself. Based on this we propose a new spillover- and MT-corrected
+magnetization transfer ratio (MTRRex) yielding Rex, the exchange dependent
+relaxation rate in the rotating frame. For verification, the amine proton
+exchange of creatine in solutions with different agar concentration was studied
+experimentally at clinical field strength of 3T. In contrast to the compared
+standard evaluation for pulsed CEST experiments, MTRasym, our approach shows no
+T2 or MT shine through effect. We demonstrate that spillover can be corrected
+properly and also quantitative evaluation of pH and creatine concentration is
+possible which proves MTRRex as quantitative CEST-MRI method. A spillover
+correction is of special interest for clinical static field strengths and
+protons resonating near the water peak. This is the case for -OH-CEST effects
+like gagCEST or glucoCEST, but also amine exchange of creatine or glutamate
+which require high B1. Although, only showed for amine exchange, we propose our
+normalization to work generally for DIACEST, PARACEST in slow- and fast
+exchange regime not just as a correction, but also for quantitative CEST-MRI.
+Applied to acute stroke induced in rat brain, the corrected CEST signal shows
+significantly higher contrast between stroke area and normal tissue as well as
+less B1 dependency compared to conventional approaches.",1302.6605v2
+2014-01-13,Influence of La and Mn vacancies on the electronic and magnetic properties of LaMnO$_{3}$ thin films grown by pulsed laser deposition,"With pulsed laser deposition we have grown c-axis oriented thin films of the
+nominal composition LaMnO$_{3}$ (LMO) on LSAT(001) substrates. We find that,
+depending on the oxygen background pressure during growth, the LMO films
+contain sizeable amounts of La and/or Mn vacancies that strongly influence
+their electronic and magnetic properties. Specifically, we show that the Mn/La
+ratio can be systematically varied from 0.92 at 0.11 mbar to 1.09 at 0.30 mbar
+of oxygen. These cationic vacancies lead to markedly different disorder effects
+that become most pronounced once the samples are fully oxygenated and thus
+strongly hole doped. All as-grown and thus slightly oxygen deficient LMO films
+are ferromagnetic insulators with saturation moments in excess of 2.5 \mu
+$_{B}$ per Mn ion, their transport and optical properties that can be
+understood in terms of trapped ferromagnetic polarons. Upon oxygen annealing,
+the most La-deficient films develop a metallic response with an even larger
+ferromagnetic saturation moment of 3.8 \mu $_{B}$ per Mn ion. In contrast, in
+the oxygenated Mn-deficient films the ferromagnetic order is almost completely
+suppressed to less than 0.5 \mu $_{B}$ per Mn ion and the transport remains
+insulator-like. We compare our results with the ones that were previously
+obtained on bulk samples and present an interpretation in terms of the much
+stronger disorder potential of the Mn vacancies as compared to the La
+vacancies. We also discuss the implications for the growth of LMO thin films
+with well-defined physical properties that, for example, are a prerequisite for
+the study of interface effects in multilayers.",1401.2820v2
+2017-04-13,Exact diagonalization and cluster mean-field study of triangular-lattice XXZ antiferromagnets near saturation,"Quantum magnetic phases near the magnetic saturation of triangular-lattice
+antiferromagnets with XXZ anisotropy have been attracting renewed interest
+since it has been suggested that a nontrivial coplanar phase, called the
+$\pi$-coplanar or $\Psi$ phase, could be stabilized by quantum effects in a
+certain range of anisotropy parameter $J/J_z$ besides the well-known 0-coplanar
+(known also as $V$) and umbrella phases. Recently, Sellmann $et$ $al$. [Phys.
+Rev. B {\bf 91}, 081104(R) (2015)] claimed that the $\pi$-coplanar phase is
+absent for $S=1/2$ from an exact-diagonalization analysis in the sector of the
+Hilbert space with only three down-spins (three magnons). We first reconsider
+and improve this analysis by taking into account several low-lying eigenvalues
+and the associated eigenstates as a function of $J/J_z$ and by sensibly
+increasing the system sizes (up to 1296 spins). A careful identification
+analysis shows that the lowest eigenstate is a chirally antisymmetric
+combination of finite-size umbrella states for $J/J_z\gtrsim 2.218$ while it
+corresponds to a coplanar phase for $J/J_z\lesssim 2.218$. However, we
+demonstrate that the distinction between 0-coplanar and $\pi$-coplanar phases
+in the latter region is fundamentally impossible from the symmetry-preserving
+finite-size calculations with fixed magnon number.} Therefore, we also perform
+a cluster mean-field plus scaling analysis for small spins $S\leq 3/2$. The
+obtained results, together with the previous large-$S$ analysis, indicate that
+the $\pi$-coplanar phase exists for any $S$ except for the classical limit
+($S\rightarrow \infty$) and the existence range in $J/J_z$ is largest in the
+most quantum case of $S=1/2$.",1704.04024v2
+2018-12-18,Electronic properties of type-II Weyl semimetal WTe$_2$. A review perspective,"Currently, there is a flurry of research interest on materials with an
+unconventional electronic structure, and we have already seen significant
+progress in their understanding and engineering towards real-life applications.
+The interest erupted with the discovery of graphene and topological insulators
+in the previous decade. The electrons in graphene simulate massless Dirac
+Fermions with a linearly dispersing Dirac cone in their band structure, while
+in topological insulators, the electronic bands wind non-trivially in momentum
+space giving rise to gapless surface states and bulk bandgap. Weyl semimetals
+in condensed matter systems are the latest addition to this growing family of
+topological materials. Weyl Fermions are known in the context of high energy
+physics since almost the beginning of quantum mechanics. They apparently
+violate charge conservation rules, displaying the ""chiral anomaly"", with such
+remarkable properties recently theoretically predicted and experimentally
+verified to exist as low energy quasiparticle states in certain condensed
+matter systems. Not only are these new materials extremely important for our
+fundamental understanding of quantum phenomena, but also they exhibit
+completely different transport phenomena. For example, massless Fermions are
+susceptible to scattering from non-magnetic impurities. Dirac semimetals
+exhibit non-saturating extremely large magnetoresistance as a consequence of
+their robust electronic bands being protected by time reversal symmetry. These
+open up whole new possibilities for materials engineering and applications
+including quantum computing. In this review, we recapitulate some of the
+outstanding properties of WTe$_2$, namely, its non-saturating titanic
+magnetoresistance due to perfect electron and hole carrier balance up to a very
+high magnetic field observed for the very first time. (Continued. Please see
+the main article).",1812.07215v1
+2020-10-24,The Evolution of the Solar-Stellar Activity,"We present a brief review of observational results contributing to modern
+ideas on the evolution of stellar activity. Basic laws, derived for both
+rotation-age and activity-rotation relationships, allow us to trace how the
+activity of low-mass stars changes with age during their stay on the main
+sequence. We focus on the evaluation of the activity properties of stars that
+could be analogs of the young Sun. Our study includes joint consideration of
+different tracers of activity, rotation and magnetic fields of Sun-like stars
+of various ages. We identify rotation periods, when the saturated regime of
+activity changes to the unsaturated mode, when the solar-type activity is
+formed: for G- and K-type stars, they are 1.1 and 3.3 days, respectively. This
+corresponds to an age interval of about 0.2-0.6 Gyr, when regular sunspot cycle
+began to be established on the early Sun. We discuss properties of the coronal
+and chromospheric activity in young Suns. Our evaluation of the EUV-fluxes in
+the spectral range of 1350-1750 A shows that the far-UV radiation of the early
+Sun was a factor of 7 times more intense than that of the present-day Sun, and
+twice higher when the regular sunspot cycle was established. For the young Sun,
+we can estimate the possible mass loss rate associated with quasi-steady
+outflow as $10^{-12} M_\odot$/yr. The results of observations of the largest
+flares on solar-type stars are also discussed, leading to conclusion that the
+most powerful phenomena occur on the fast-rotating stars in the saturated
+activity regime. Our estimate of the stellar magnetic fields makes it possible
+to evaluate the maximal possible flare energy. This could help us better
+understand the origin of extreme events on the Sun in the past.",2010.12922v1
+2020-11-25,Supergap and subgap enhanced currents in asymmetric {S_1FS_2} Josephson junctions,"We have theoretically studied the supercurrent profiles in three-dimensional
+normal metal and ferromagnetic Josephson configurations, where the magnitude of
+the superconducting gaps in the superconducting leads are unequal, i.e.,
+$\Delta_1\neq \Delta_2$, creating asymmetric $S_1NS_2$ and $S_1FS_2$ systems.
+Our results reveal that by increasing the ratio of the superconducting gaps
+$\Delta_2/\Delta_1$, the critical supercurrent in a ballistic $S_1NS_2$ system
+can be enhanced by more than $100\%$, and reaches a saturation point, or decays
+away, depending on the junction thickness, magnetization strength, and chemical
+potential. The total critical current in a diffusive $S_1NS_2$ system was found
+to be enhanced by more than $50\%$ parabolically, and reaches saturation by
+increasing one of the superconducting gaps. In a uniform ferromagnetic
+junction, the supercurrent undergoes reversal by increasing
+$\Delta_2/\Delta_1>1$. Through decomposing the total supercurrent into its
+supergap and subgap components, our results illustrate their crucial relative
+contributions to the Josephson current flow. It was found that the competition
+of subgap and supergap currents in a $S_1FS_2$ junction results in the
+emergence of second harmonics in the current-phase relation. In contrast to a
+diffusive asymmetric Josephson configuration, the behavior of the supercurrent
+in a ballistic system with $\Delta_2/\Delta_1=1$ can be properly described by
+the subgap current component only, in a wide range of parameter sets, including
+Fermi level mismatch, magnetization strength, and junction thickness.
+Interestingly, when $\Delta_2/\Delta_1>1$, our results have found multiple
+parameter sets where the total supercurrent is driven by the supergap
+component. Therefore, our comprehensive study highlights the importance of
+subgap and supergap supercurrent components in both the ballistic and diffusive
+regimes.",2011.12967v2
+2023-09-26,Tensor-valued and frequency-dependent diffusion MRI and magnetization transfer saturation MRI evolution during adult mouse brain maturation,"Although rodent models are a predominant study model in neuroscience
+research, research investigating healthy rodent brain maturation remains
+limited. This motivates further study of normal brain maturation in rodents to
+exclude confounds of developmental changes from interpretations of disease
+mechanisms. 11 C57Bl/6 mice (6 males) were scanned longitudinally at 3, 4, 5,
+and 8 months of age using frequency-dependent and tensor-valued diffusion MRI
+(dMRI), and Magnetization Transfer saturation (MTsat) MRI. Total kurtosis
+showed significant increases over time in all regions, which was driven by
+increases in isotropic kurtosis while anisotropic kurtosis remained stable.
+Increases in total and isotropic kurtosis with age were matched with increases
+in MTsat. Quadratic fits revealed that most metrics show a maximum/minimum
+around 5-6 months of age. Most dMRI metrics revealed significantly different
+trajectories between males and females, while the MT metrics did not. Linear
+fits between kurtosis and MT metrics highlighted that changes in total kurtosis
+found throughout normal brain development are driven by isotropic kurtosis,
+while differences in total kurtosis between brain regions are driven by
+anisotropic kurtosis. Overall, the trends observed in conventional dMRI and MT
+metrics are comparable to previous studies on normal brain development, while
+the trajectories of our more advanced dMRI metrics provide novel insight. Based
+on the developmental trajectories of tensor-valued dMRI and MT metrics, our
+results suggest myelination during brain maturation is not a main contributor
+to microscopic diffusion anisotropy and anisotropic kurtosis in axons. For
+studies that only calculate total kurtosis, we suggest caution in attributing
+neurobiological changes to changes in total kurtosis as we show here constant
+anisotropic kurtosis in the presence of increasing myelin content.",2309.15202v1
+2024-01-08,Maser polarization through anisotropic pumping,"(Abridged) Polarized emission from masers is an excellent tool to study
+magnetic fields in maser sources. The linear polarization of most masers is
+understood as an interplay of maser saturation and anisotropic pumping.
+However, for the latter mechanism, no quantitative modeling has been presented
+yet. We present a comprehensive model of maser polarization, including
+quantitative modeling of both anisotropic pumping and the effects of maser
+saturation on the polarization of masers. We extend regular maser excitation
+modeling with a dimension that describes the molecular population alignments,
+as well as including the linear polarization dimension to the radiative
+transfer. The results of the excitation analysis yield the anisotropic pumping
+and decay parameters, that are subsequently used in one-dimensional proper
+maser polarization radiative transfer modeling. We present the anisotropic
+pumping parameters for a variety of transitions from class I CH$_3$OH masers,
+H$_2$O masers and SiO masers. SiO masers are highly anisotropically pumped due
+to them occurring in the vicinity of a late-type star, that irradiates the
+maser region with a strong directional radiation field. Class I CH$_3$OH masers
+and H$_2$O masers occur in association with shocks, and they are modestly
+anisotropically pumped due to the anisotropy of the excitation region. Our
+modeling constitutes the first quantitative constraints on the anisotropic
+pumping of masers. We find that anisotropic pumping can explain the high
+polarization yields of SiO masers, as well as the modest polarization of
+unsaturated class I CH$_3$OH masers. We predict that the $183$ GHz H$_2$O maser
+is strongly anisotropically pumped. Finally, we outline a mechanism through
+which non-Zeeman circular polarization is produced, when the magnetic field
+changes direction along the propagation through an anisotropically pumped
+maser.",2401.04185v1
+1998-02-17,Nonlinear Evolution of the Magnetorotational Instability in Ion-Neutral Disks,"We carry out three-dimensional magnetohydrodynamical simulations of the
+magnetorotational (Balbus-Hawley) instability in weakly-ionized plasmas. We
+adopt a formulation in which the ions and neutrals each are treated as separate
+fluids coupled only through a collisional drag term. Ionization and
+recombination processes are not considered. The linear stability of the
+ion-neutral system has been previously considered by Blaes and Balbus (1994).
+Here we extend their results into the nonlinear regime by computing the
+evolution of Keplerian angular momentum distribution in the local shearing box
+approximation. We find significant turbulence and angular momentum transport
+when the collisional frequency is on order 100 times the orbital frequency. At
+higher collision rates, the two-fluid system studied here behaves much like the
+fully ionized systems studied previously. At lower collision rates the
+evolution of the instability is determined primarily by the properties of the
+ions, with the neutrals acting as a sink for the turbulence. Since in this
+regime saturation occurs when the magnetic field is superthermal with respect
+to the ion pressure, we find the amplitude of the magnetic energy and the
+corresponding angular momentum transport rate is proportional to the ion
+density. Our calculations show the ions and neutrals are essentially decoupled
+when the collision frequency is less than 0.01 times the orbital frequency; in
+this case the ion fluid behaves as in the single fluid simulations and the
+neutrals remain quiescent. We find that purely toroidal initial magnetic field
+configurations are unstable to the magnetorotational instability across the
+range of coupling frequencies.",9802227v1
+1998-08-22,Three-Dimensional Evolution of the Parker Instability under a Uniform Gravity,"Using an isothermal MHD code, we have performed three-dimensional,
+high-resolution simulations of the Parker instability. The initial equilibrium
+system is composed of exponentially-decreasing isothermal gas and magnetic
+field (along the azimuthal direction) under a uniform gravity. The evolution of
+the instability can be divided into three phases: linear, nonlinear, and
+relaxed. During the linear phase, the perturbations grow exponentially with a
+preferred scale along the azimuthal direction but with smallest possible scale
+along the radial direction, as predicted from linear analyses. During the
+nonlinear phase, the growth of the instability is saturated and flow motion
+becomes chaotic. Magnetic reconnection occurs, which allows gas to cross field
+lines. This, in turn, results in the redistribution of gas and magnetic field.
+The system approaches a new equilibrium in the relaxed phase, which is
+different from the one seen in two-dimensional works. The structures formed
+during the evolution are sheet-like or filamentary, whose shortest dimension is
+radial. Their maximum density enhancement factor relative to the initial value
+is less than 2. Since the radial dimension is too small and the density
+enhancement is too low, it is difficult to regard the Parker instability alone
+as a viable mechanism for the formation of giant molecular clouds.",9808244v1
+1999-04-16,Battery and Dynamo theory in the Kerr metric,"The generation and evolution of magnetic fields in the plasma accreting into
+a rotating black hole is studied in the 3+1 split of the Kerr metric. Attention
+is focused on effects of the gravitomagnetic potential. The gravitomagnetic
+force appears as battery term in the generalized Ohm's law. The gravitomagnetic
+battery is likely to saturate at higher field strength than the classical
+Biermann battery.
+  The coupling of the gravitomagnetic potential with electric fields appears as
+gravitomagnetic current in Maxwell's equations. In the magnetohydrodynamic
+induction equation, this current re-appears as source term for the poloidal
+magnetic field, which can produce closed magnetic structures around an
+accreting black hole. In principle, even self-excited axisymmetric dynamo
+action is possible, which means that Cowling's anti-dynamo theorem does not
+hold in the Kerr metric.
+  Finally, simulations of the alpha-Omega dynamo in accretion flows into the
+hole are presented. I assume a simple expression of alpha in this relativistic
+context. The modes of the dynamo are oscillating for dynamo numbers which are
+typical for accretion disks. In a zero angular momentum flow into a Kerr black
+hole there is still shear, i.e. the angular velocity, Omega, of the plasma
+equals the angular velocity of space, omega, and it has been speculated (Meier
+1998) that even then a dynamo could operate. This is shown to be unlikely due
+to the rapid accretion.",9904215v1
+2000-06-07,The Effect of Expansion on Mass Entrainment and Stability of Super-Alfvénic Jets,"We extend investigations of mass entrainment by jets, which previously have
+focused on cylindrical supermagnetosonic jets and expanding trans-Alfv\'enic
+jets, to a set of expanding supermagnetosonic jets. We precess these jets at
+the origin to excite the helical mode of the Kelvin-Helmholtz (or KH)
+instability, in order to compare the results with predictions from linear
+stability analysis. We analyze this simulation set for the spatial development
+of magnetized mass, which we interpret as jet plus entrained, initially
+unmagnetized external mass. As with the previous simulation sets, we find that
+the growth of magnetized mass is associated with the growth of the KH
+instability through linear, nonlinear, and saturated stages and with the
+expansion of magnetized material in simulated observations of the jet. From
+comparison of measured wavelengths and wave speeds with the predictions from
+linear stability analysis, we see evidence that the KH instability is the
+primary cause for mass entrainment in these simulations, and that the expansion
+reduces the rate of mass entrainment. This reduced rate can be observed as a
+somewhat greater distance between the two transition points separating the
+three stages of expansion.",0006102v1
+2004-08-24,The polarization of mm methanol masers,"We present a survey of the polarization properties of mm-wavelength methanol
+masers, comprising both classes, and transitions from 84.5 to 157.0 GHz. Linear
+polarization is found in more than half of the observed objects, and circular
+polarization is tentatively detected in two sources. Class I and Class II
+CH_3OH masers show similar polarization properties.The largest linear
+polarization is found in the 133 GHz Class I maser towards L379 (39.5 %), and
+in the 157 GHz Class II maser towards G9.62+0.19 (36.7 %). The spectral
+profiles of the polarization angle of Class I masers are mostly flat, except
+for two sources showing a linear slope. Since the mm-line methanol masers are
+expected to be weakly (or not) saturated, we suggest that the stronger
+fractional polarizations found by us are enhanced by anisotropic pumping and
+radiative losses. In NGC 7538, we find, for both maser classes, a good
+agreement between our polarization angles, and those measured for the
+submillimeter dust continuum. This can be taken as evidence for magnetic
+alignment of dust grains. It is also possible that an unsaturated maser with
+equally populated magnetic substates simply amplifies polarized continuum seed
+radiation. For Class II masers, the polarization properties of the various
+velocity components towards a given source with detectable polarization are
+quite homogeneous. A possible explanation is discussed. Since methanol is
+non-paramagnetic, the circular polarization of the unsaturated maser emission
+can only be due to variations of the angle between the magnetic field and the
+line of sight along the maser propagation path.",0408446v1
+2005-10-31,A Qualitative Interpretation of the Second Solar Spectrum of Ce ll,"This is a theoretical investigation on the formation of the linearly
+polarized line spectrum of ionized cerium in the sun. We calculate the
+scattering line polarization pattern emergent from a plane-parallel layer of Ce
+{\sc ii} atoms illuminated from below by the photospheric radiation field,
+taking into account the differential pumping induced in the various magnetic
+sublevels by the anisotropic radiation field. We find that the line
+polarization pattern calculated with this simple model is in good qualitative
+agreement with reported observations. Interestingly, the agreement improves
+when some amount of atomic level depolarization is considered. We find that the
+best fit to the observations corresponds to the situation where the ground and
+metastable levels are depolarized to about one fifth of the corresponding value
+obtained in the absence of any depolarizing mechanism. One possibility to have
+this situation is that the depolarizing rate value of elastic collisions is
+exactly $D=10^6{\rm s}^{-1}$, which is rather unlikely. Therefore, we interpret
+that fact as} due to the presence of a turbulent magnetic field in the limit of
+saturated Hanle effect for the lower-levels. For this turbulent magnetic field
+we obtain a lower limit of 0.8 gauss and an upper limit of 200-300 gauss.",0511011v1
+1999-03-26,Surface effects in nanoparticles: application to maghemite $γ$-Fe_{2}O_{3},"We present a microscopic model for nanoparticles, of the maghemite ($\gamma
+$% -Fe$_{2}$O$_{3}$) type, and perform classical Monte Carlo simulations of
+their magnetic properties. On account of M\""{o}ssbauer spectroscopy and
+high-field magnetisation results, we consider a particle as composed of a core
+and a surface shell of constant thickness. The magnetic state in the particle
+is described by the anisotropic classical Dirac-Heisenberg model including
+exchange and dipolar interactions and bulk and surface anisotropy. We consider
+the case of ellipsoidal (or spherical) particles with free boundaries at the
+surface. Using a surface shell of constant thickness ($\sim 0.35$ nm) we vary
+the particle size and study the effect of surface magnetic disorder on the
+thermal and spatial behaviors of the net magnetisation of the particle. We
+study the shift in the surface ``critical region'' for different
+surface-to-core ratios of the exchange coupling constants. It is also shown
+that the profile of the local magnetisation exhibits strong temperature
+dependence, and that surface anisotropy is reponsible for the non saturation of
+the magnetisation at low temperatures.",9903398v5
+2001-05-16,"Correlation functions, free energies and magnetizations in the two-dimensional random-field Ising model","Transfer-matrix methods are used to calculate spin-spin correlation functions
+($G$), Helmholtz free energies ($f$) and magnetizations ($m$) in the
+two-dimensional random-field Ising model close to the zero-field bulk critical
+temperature $T_{c 0}$, on long strips of width $L = 3 - 18$ sites, for binary
+field distributions. Analysis of the probability distributions of $G$ for
+varying spin-spin distances $R$ shows that describing the decay of their
+averaged values by effective correlation lengths is a valid procedure only for
+not very large $R$. Connections between field-- and correlation function
+distributions at high temperatures are established, yielding approximate
+analytical expressions for the latter, which are used for computation of the
+corresponding structure factor. It is shown that, for fixed $R/L$, the
+fractional widths of correlation-function distributions saturate asymptotically
+with $L^{-2.2}$. Considering an added uniform applied field $h$, a connection
+between $f(h)$, $m(h)$, the Gibbs free energy $g(m)$ and the distribution
+function for the uniform magnetization in zero uniform field, $P_0(m)$, is
+derived and first illustrated for pure systems, and then applied for non-zero
+random field. From finite-size scaling and crossover arguments, coupled with
+numerical data, it is found that the width of $P_0(m)$ varies against
+(non-vanishing, but small) random-field intensity $H_0$ as $H_0^{-3/7}$.",0105326v1
+2002-03-04,Order to disorder transition in the XY-like quantum magnet Cs2CoCl4 induced by noncommuting applied fields,"We explore the effects of noncommuting applied fields on the ground-state
+ordering of the quasi-one-dimensional spin-1/2 XY-like antiferromagnet Cs2CoCl4
+using single-crystal neutron diffraction. In zero field interchain couplings
+cause long-range order below T_N=217(5) mK with chains ordered
+antiferromagnetically along their length and moments confined to the (b,c)
+plane. Magnetic fields applied at an angle to the XY planes are found to
+initially stabilize the order by promoting a spin-flop phase with an increased
+perpendicular antiferromagnetic moment. In higher fields the antiferromagnetic
+order becomes unstable and a transition occurs to a phase with no long-range
+order in the (b,c) plane, proposed to be a spin liquid phase that arises when
+the quantum fluctuations induced by the noncommuting field become strong enough
+to overcome ordering tendencies. Magnetization measurements confirm that
+saturation occurs at much higher fields and that the proposed spin-liquid state
+exists in the region 2.10 < H_SL < 2.52 T || a. The observed phase diagram is
+discussed in terms of known results on XY-like chains in coexisting
+longitudinal and transverse fields.",0203070v1
+2004-02-03,Observation of ferromagnetism above 900 K in Cr-GaN and Cr-AlN,"We report the observation of ferromagnetism at over 900K in Cr-GaN and Cr-AlN
+thin films. The saturation magnetization moments in our best films of Cr-GaN
+and Cr-AlN at low temperatures are 0.42 and 0.6 u_B/Cr atom, respectively,
+indicating that 14% and 20%, of the Cr atoms, respectively, are magnetically
+active. While Cr-AlN is highly resistive, Cr-GaN exhibits thermally activated
+conduction that follows the exponential law expected for variable range hopping
+between localized states. Hall measurements on a Cr-GaN sample indicate a
+mobility of 0.06 cm^2/V.s, which falls in the range characteristic of hopping
+conduction, and a free carrier density (1.4E20/cm^3), which is similar in
+magnitude to the measured magnetically-active Cr concentration (4.9E19/cm^3). A
+large negative magnetoresistance is attributed to scattering from loose spins
+associated with non-ferromagnetic impurities. The results indicate that
+ferromagnetism in Cr-GaN and Cr-AlN can be attributed to the double exchange
+mechanism as a result of hopping between near-midgap substitutional Cr impurity
+bands.",0402103v2
+2004-04-16,Non-Markovian Effects on the Two-Dimensional Magnetotransport: Low-field Anomaly in Magnetoresistance,"We discuss classical magnetotransport in a two-dimensional system with strong
+scatterers. Even in the limit of very low field, when $\omega_c \tau \ll 1$
+($\omega_c$ is the cyclotron frequency, $\tau$ is the scattering time) such a
+system demonstrates strong negative magnetoresistance caused by non-Markovian
+memory effects. A regular method for the calculation of non-Markovian
+corrections to the Drude conductivity is presented. A quantitative theory of
+the recently discovered anomalous low-field magnetoresistance is developed for
+the system of two-dimensional electrons scattered by hard disks of radius $a,$
+randomly distributed with concentration $n.$ For small magnetic fields the
+magentoresistance is found to be parabolic and inversely proportional to the
+gas parameter, $ \delta \rho_{xx}/\rho \sim - (\omega_c \tau)^2 / n a^2.$ In
+some interval of magnetic fields the magnetoresistance is shown to be linear
+$\delta \rho_{xx}/\rho \sim - \omega_c \tau $ in a good agreement with the
+experiment and numerical simulations. Magnetoresistance saturates for $\omega_c
+\tau \gg na^2$, when the anomalous memory effects are totally destroyed by the
+magnetic field. We also discuss magnetotransport at very low fields and show
+that at such fields magnetoresistance is determined by the trajectories having
+a long Lyapunov region.",0404397v2
+2004-07-28,Paramagnetic reentrance of the ac-screening: Evidence of vortex avalanches in Pb thin films,"We have studied the influence of a square array of pinning centers on the
+dynamics of vortex avalanches in Pb thin films by means of ac- and dc-
+magnetization measurements. Close to the superconducting transition Tc the
+commensurability between the vortex lattice and the pinning array leads to the
+well known local increments of the critical current. As temperature T
+decreases, matching features progressively fade out and eventually disappear.
+Further down in temperature vortex avalanches develop and dominate the magnetic
+response. These avalanches manifest themselves as jumps in the dc-magnetization
+and produce a lower ac-shielding giving rise to a paramagnetic reentrance in
+the ac-screening x'(T). Within the flux jump regime two subregimes can be
+identified. Close to the boundary where vortex avalanches develope, the field
+separation between consecutive jumps follow the periodicity of the pinning
+array and a field and temperature dependent screening is observed. In this
+regime, the response also depends on frequency f in agreement with theoretical
+models for magnetothermal instabilities. At low enough temperatures and fields,
+the screening saturates to a constant value independent of T, H, and f, where
+jumps are randomly distributed. We have also found that vortex instabilities
+occupy a larger portion of the H-T diagram in patterned samples than in films
+without nanoengineered pinning sites. Finally, we discuss the possible origin
+of the vortex avalanches and compare our results with previous experimental and
+theoretical studies.",0407737v1
+2005-01-21,The isotropic XY model on the inhomogeneous periodic chain,"The static and dynamic properties of the isotropic XY-model $(s=1/2)$ on the
+inhomogeneous periodic chain, composed of \emph{N} segments with \emph{n}
+different exchange interactions and magnetic moments, in a transverse field
+\emph{h} are obtained exactly at arbitrary temperatures. The properties are
+determined by introducing the generalized Jordan-Wigner transformation and by
+reducing the problem to a diagonalization of a finite matrix of \emph{n-th}
+order. The diagonalization procedure is discussed in detail and the critical
+behaviour induced by the transverse field, at T=0, is presented. The quantum
+transitions are determined by analyzing the behaviour of the induced
+magnetization, defined as $(1/n)\sum_{m=1}^{n}\mu_{m}<S_{j,m}^{z}>$ where
+$\mu_{m}$ is the magnetic moment at site \emph{m} within the segment \emph{j},
+as a function of the field, and the critical fields determined exactly. The
+dynamic correlations, $<S_{j,m}^{z}(t)S_{j^{'},m^{'}}^{z}(0)>$, and the dynamic
+susceptibility $\chi_{q}^{zz}(\omega)$ are also obtained at arbitrary
+temperatures. Explicit results are also presented in the limit T=0, where the
+critical behaviour occurs, for the static susceptibility $\chi_{q}^{zz}(0)$ as
+a function of the transverse field \emph{h}, and for the frequency dependency
+of dynamic susceptibility $\chi_{q}^{zz}(\omega)$. Also in this limit, the
+transverse time-correlation $<S_{j,m}^{x}(t)S_{j^{'},m^{'}}^{x}(0)>$, the
+dynamic and isothermal susceptibilities, $\chi_{q}^{xx}(\omega)$ and
+$\chi_{T}^{xx}$, are obtained for the transverse field greater or equal than
+the saturation field.",0501525v1
+2005-11-29,Lower critical field and intragrain critical current density in the ruthenate-cuprate RuSr$_{2}$Gd$_{1.5}$Ce$_{0.5}$Cu$_{2}$O$_{10}$,"The lower critical field of the grains, $H_{c1}$, and the intragrain critical
+current density, $J_{c}$, were determined for the superconducting
+ruthenate-cuprate RuSr$_{2}$Gd$_{1.5}$Ce$_{0.5}$Cu$_{2}$O$_{10-\delta}$
+[Ru-1222(Gd)] through a systematic study of the hysteresis in magnetoresistance
+loops. A reliable method, based on the effects of the magnetization of the
+grains on the net local field at the intergranular junctions is provided,
+circumventing the problem of the strong masking of the superconducting
+diamagnetic signal by the ferromagnetic background. The temperature dependency
+of $H_{c1}$ and $J_{c}$ both exhibit a smooth increase on cooling without
+saturation down to $T/T_{SC}$ $\cong $ 0.2. The obtained $H_{c1}$ values vary
+between 150 and 1500 Oe in the 0.2 $\leq $ $% T/T_{SC}$ $\leq $ 0.4 interval,
+for samples annealed in an oxygen flow; oxygenation under high pressure (50
+atm) leads to a further increase. These values are much larger than the
+previously reported rough assessments (25-50 Oe), using conventional
+magnetization measurements. High $J_{c}$ values of $% \sim $ 10$^{7}$
+A/cm$^{2}$, comparable to the high-T$_{c}$ cuprates, were obtained. The
+$H_{c1}(T)$ and $J_{c}(T)$ dependencies are explained in the context of a
+magnetic phase separation scenario.",0511718v1
+2006-04-11,A single layer of Mn in a GaAs quantum well: a ferromagnet with quantum fluctuations,"Some of the highest transition temperatures achieved for Mn-doped GaAs have
+been in delta-doped heterostructures with well-separated planes of Mn. But in
+the absence of magnetic anisotropy, the Mermin-Wagner theorem implies that a
+single plane of magnetic ions cannot be ferromagnetic. Using a Heisenberg
+model, we show that the same mechanism that produces magnetic frustration and
+suppresses the transition temperature in bulk Mn-doped GaAs, due to the
+difference between the light and heavy band masses, can stabilize ferromagnetic
+order for a single layer of Mn in a GaAs quantum well. This comes at the price
+of quantum fluctuations that suppress the ordered moment from that of a fully
+saturated ferromagnet. By comparing the predictions of Heisenberg and
+Kohn-Luttinger models, we conclude that the Heisenberg description of a
+Mn-doped GaAs quantum well breaks down when the Mn concentration becomes large,
+but works quite well in the weak-coupling limit of small Mn concentrations.
+This comparison allows us to estimate the size of the quantum fluctuations in
+the quantum well.",0604288v4
+2007-08-19,Incommensurate Spin Ordering and Fluctuations in underdoped La_{2-x}Ba_{x}CuO_{4},"Using neutron scattering techniques, we have studied incommensurate spin
+ordering as well as low energy spin dynamics in single crystal underdoped \LBCO
+with x$\sim$0.095 and 0.08; high temperature superconductors with T$_C \sim$ 27
+K and 29 K respectively. Static two dimensional incommensurate magnetic order
+appears below T$_N$=39.5 $\pm$ 0.3 K in \LBCO (x=0.095) and a similar
+temperature for x=0.08 within the low temperature tetragonal phase. The spin
+order is unaffected by either the onset of superconductivity or the application
+of magnetic fields of up to 7 Tesla applied along the c-axis in the x=0.095
+sample. Such magnetic field {\it independent} behaviour is in marked contrast
+with the field induced enhancement of the staggered magnetisation observed in
+the related \LSCO system, indicating this phenomenon is not a universal
+property of cuprate superconductors. Surprisingly, we find that
+incommensurability $\delta $ is only weakly dependent on doping relative to
+\LSCO. Dispersive excitations in \LBCO (x=0.095) at the same incommensurate
+wavevector persist up to at least 60 K. The dynamical spin susceptibility of
+the low energy spin excitations saturates below \tc, in a similar manner to
+that seen in the superconducting state of La$_2$CuO$_{4+y}$.",0708.2519v3
+2008-09-17,"Late stage, non-equilibrium dynamics in the dipolar Ising model","Magnetic domain structures are a fascinating area of study with interest
+deriving both from technological applications and fundamental scientific
+questions. The nature of the striped magnetic phases observed in ultra-thin
+films is one such intriguing system. The non-equilibrium dynamics of such
+systems as they evolve toward equilibrium has only recently become an area of
+interest and previous work on model systems showed evidence of complex, slow
+dynamics with glass-like properties as the stripes order mesoscopically. To aid
+in the characterization of the observed phases and the nature of the
+transitions observed in model systems we have developed an efficient method for
+identifying clusters or domains in the spin system, where the clusters are
+based on the stripe orientation. Thus we are able to track the growth and decay
+of such clusters of stripes in a Monte Carlo simulation and observe directly
+the nature of the slow dynamics. We have applied this method to consider the
+growth and decay of ordered domains after a quench from a saturated magnetic
+state to temperatures near and well below the critical temperature in the two
+dimensional dipolar Ising model. We discuss our method of identifying stripe
+domains or clusters of stripes within this model and present the results of our
+investigations.",0809.2808v1
+2009-01-21,Instability of the collinear phase in two-dimensional ferromagnet in strong in-plane magnetic field,"It is well-known that in thin ferromagnetic film with a net magnetization
+perpendicular to the film the collinear arrangement of spins is unstable in an
+in-plane field $H$ smaller than its saturation value $H_c$. Existence of a
+stripe phase was proposed with elongated domains of alternating direction of
+magnetization component perpendicular to the film. We consider in the present
+paper the strong-field regime $H<H_c$ and discuss the minimal microscopic model
+describing this phenomenon, two-dimensional Heisenberg ferromagnet with strong
+easy-axis anisotropy and dipolar forces. The noncollinear (stripe) phase is
+discussed using the technique of the Bose-Einstein condensation of magnons.
+Some previously unknown results are observed concerning the stripe phase.
+Evolution is established of the spin arrangement in the noncollinear phase upon
+the field rotation within the plane. We find a rapid decreasing of the period
+of the stripe structure as the field decreases. We demonstrate that spins
+components perpendicular to the film form a sinusoid in the noncollinear phase
+at $H\approx H_c$ that transforms to a step-like profile upon the field
+decreasing so that the domain wall density decreases from unity to a value much
+smaller than unity. The spin-wave spectrum in the noncollinear phase is
+discussed.",0901.3259v2
+2009-03-05,Altair - the 'hottest' magnetically active star in X-rays,"The A7 star Altair is one of the hottest magnetically active stars. Its
+proximity to the Sun allows a detailed investigation of a corona in X-rays for
+a star with a shallow convection zone. We used a deep XMM-Newton observation of
+Altair and analyzed X-ray light curves, spectra, and emission lines,
+investigated the temporal behavior and properties of the X-ray emitting plasma
+and studied the global coronal structure. We find that Altair's corona with an
+X-ray luminosity of L_X =1.4 x 10^27 erg/s and a very low activity level of log
+L_X/L_bol = -7.4, is located predominantly at low latitude regions. The X-ray
+emission is dominated by cool plasma (1-4 MK) at low density, and elemental
+abundances exhibit a solar-like FIP effect and Ne/O ratio. The X-ray brightness
+varies by 30 % over the observation, most likely due to rotational modulation
+and minor activity; in contrast, no strong flares or significant amounts of hot
+plasma were detected. The X-ray activity level of Altair is apparently close to
+the saturation level, which is reduced by roughly four orders of magnitude when
+compared to late-type stars. With its fast rotation, Altair provides an
+inefficient, but very stable dynamo that mainly operates in convective layers
+below its 'cooler' surface areas around the equator. This dynamo mechanism
+results in magnetic activity and leads to X-ray properties that are overall
+very similar to those of the quiescent Sun, despite very different underlying
+stars.",0903.0966v1
+2009-03-13,2D XY Behavior observed in quasi-2D quantum Heisenberg antiferromagnets,"The magnetic properties of a new family of molecular-based quasi-two
+dimension $S=1/2$ Heisenberg antiferromagnets are reported. Three compounds,
+($Cu(pz)_2(ClO_4)_2$, $Cu(pz)_2(BF_4)_2$, and $[Cu(pz)_2(NO_3)](PF_6)$) contain
+similar planes of Cu$^{2+}$ ions linked into magnetically square lattices by
+bridging pyrazine molecules (pz = $C_4H_4N_2$). The anions provide charge
+balance as well as isolation between the layers. Single crystal measurements of
+susceptibility and magnetization, as well as muon spin relaxation studies,
+reveal low ratios of N\'{e}el temperatures to exchange strengths ($4.25 / 17.5
+= 0.243$, $3.80/15.3=0.248$, and $3.05/10.8=0.282$, respectively) while the
+ratio of the anisotropy fields $H_A$ (kOe) to the saturation field
+$H_\mathrm{SAT}$ (kOe) are small ($2.6/490 = 5.3\times10^{-3}$,
+$2.4/430=5.5\times10^{-3}$, and $0.07/300=2.3\times10^{-4}$, respectively),
+demonstrating close approximations to a 2D Heisenberg model. The
+susceptibilities of ClO$_4$ and BF$_4$ show evidence of an exchange anisotropy
+crossover (Heisenberg to $XY$) at low temperatures; their ordering transitions
+are primarily driven by the $XY$ behavior with the ultimate 3D transition
+appearing parasitically. The PF$_6$ compound remains Heisenberg-like at all
+temperatures, with its transition to the N\'{e}el state due to the interlayer
+interactions. Effects of field-induced anisotropy have been observed.",0903.2470v1
+2009-04-08,Anisotropy of the upper critical field in a Co-doped BaFe2As2 single crystal,"The temperature dependence of the upper critical magnetic field (Hc2) in a
+BaFe1.84Co0.16As2 single crystal was determined via resistivity, for the
+inter-plane (H^ab) and in-plane (H//ab) directions in pulsed and static
+magnetic fields of up to 60 T. Suppressing superconductivity in a pulsed
+magnetic field at 3He temperatures permits us to construct an H-T phase diagram
+from quantitative Hc2(0) values and determine its behavior in low temperatures.
+Hc2(0) with H//ab (Hc2//(0)) and H^ab (Hc2^(0)) are ~ 55 T and 50 T
+respectively. These values are ~ 1.2 - 1.4 times larger than the weak-coupling
+Pauli paramagnetic limit (Hp = 1.84 Tc), indicating that enhanced paramagnetic
+limiting is essential and this superconductor is unconventional. While Hc2//ab
+is saturated at low temperature, Hc2 with H^ab (Hc2^) exhibits almost linear
+temperature dependence towards T = 0 K which results in reduced anisotropy of
+Hc2 in low temperature. The anisotropy of Hc2 was ~ 3.4 near Tc, and decreases
+rapidly with lower temperatures reaching ~ 1.1 at T = 0.7 K.",0904.1418v3
+2009-05-08,Magnetotransport in polycrystalline La$_{2/3}$Sr$_{1/3}$MnO$_{3}$ thin films of controlled granularity,"Polycrystalline La$_{2/3}$Sr$_{1/3}$MnO$_{3}$ (LSMO) thin films were
+synthesized by pulsed laser ablation on single crystal (100) yttria-stabilized
+zirconia (YSZ) substrates to investigate the mechanism of magneto-transport in
+a granular manganite. Different degrees of granularity is achieved by using the
+deposition temperature (T$_{D}$) of 700 and 800 $^{0}$C. Although no
+significant change in magnetic order temperature (T$_C$) and saturation
+magnetization is seen for these two types of films, the temperature and
+magnetic field dependence of their resistivity ($\rho$(T, H)) is strikingly
+dissimilar. While the $\rho$(T,H) of the 800 $^{0}$C film is comparable to that
+of epitaxial samples, the lower growth temperature leads to a material which
+undergoes insulator-to-metal transition at a temperature (T$_{P}$ $\approx$ 170
+K) much lower than T$_C$. At T $\ll$ T$_P$, the resistivity is characterized by
+a minimum followed by ln $\emph{T}$ divergence at still lower temperatures. The
+high negative magnetoresistance ($\approx$ 20$%$) and ln $\emph{T}$ dependence
+below the minimum are explained on the basis of Kondo-type scattering from
+blocked Mn-spins in the intergranular material. Further, a striking feature of
+the T$_D$ = 700 $^{0}$C film is its two orders of magnitude larger anisotropic
+magnetoresistance (AMR) as compared to the AMR of epitaxial films. We attribute
+it to unquenching of the orbital angular momentum of 3d electrons of Mn ions in
+the intergranular region where crystal field is poorly defined.",0905.1306v1
+2009-07-29,"Domain walls, canted states and stripe width variation in ultrathin magnetic films with perpendicular anisotropy","Stripe width variation in ultrathin magnetic films is a well known phenomenon
+still not well understood. We analyze this problem considering a 2D Heisenberg
+model with ferromagnetic exchange interactions, dipolar interactions and
+perpendicular anisotropy, relevant e.g. in Fe/Cu(001) films. By extending a
+classic result of Yafet & Gyorgy (YG) and using Monte Carlo simulations we
+calculate the complete zero temperature phase diagram of the model. Through
+this calculation we analyze the correlation between domain walls structure and
+stripe width variation, as the perpendicular anisotropy changes. In particular,
+we found evidences that the recently detected canted state becomes the ground
+state of the system close to the Spin Reorientation Transition (SRT) for any
+value of the exchange to dipolar couplings ratio. Far away of the SRT the
+canted ground state is replaced by a saturated stripes state, in which
+in--plane magnetization components are only present inside the walls. We find
+that the domain wall structure strongly depends on the perpendicular
+anisotropy: close to SRT it is well described by YG approximation, but a strong
+departure is observed in the large anisotropy limit. Moreover, we show that
+stripe width variation is directly related to domain wall width variation with
+the anisotropy.",0907.5153v1
+2009-12-08,"Anisotropy of upper critical field in one-dimensional organic system, (TMTTF)$_2$PF$_6$ under extremely high pressure","We have measured the temperature dependent resistivity of (TMTTF)$_2$PF$_6$
+to 7 GPa using a turnbuckle DAC (diamond anvil cell) and in magnetic field up
+to 5 T. Unlike many other organic conductors, a zero resistance was observed in
+the superconducting state even under high pressures. Superconductivity was
+observed over a range of $P$ = 4.18 GPa to 6.03 GPa and showed a peak $T_c$ of
+2.25 K at 4.58 GPa. The temperature dependence of the upper critical magnetic
+field $H_{c2}(T)$ was determined via resistivity at $P$ = 4.58 GPa, for the
+intrachain ($a$), interchain ($b'$), and interlayer ($c^*$) configurations and
+the $H_{c2}(T)$ displays positive curvature without saturation, which may be
+originated by a FFLO state, for magnetic field along a-axis and $b'$-axis in T
+$\ge$ 0.5 K for $P$ = 4.48 GPa. This feature is suppressed with increasing
+pressure and the orbital pair breaking mechanism becomes dominant. The values
+of the Ginzberg-Landau coherence length for three different axes obtained from
+this work shows that (TMTTF)$_2$PF$_6$ is an anisotropic three - dimensional
+superconductor.",0912.1391v1
+2009-12-09,X-ray emitting MHD accretion shocks in classical T Tauri stars. Case for moderate to high plasma-beta values,"AIMS. We investigate the stability and dynamics of accretion shocks in CTTSs,
+considering the case of beta >= 1 in the post-shock region. In these cases the
+1D approximation is not valid and a multi-dimensional MHD approach is
+necessary.
+  METHODS. We model an accretion stream propagating through the atmosphere of a
+CTTS and impacting onto its chromosphere, by performing 2D axisymmetric MHD
+simulations. The model takes into account the stellar magnetic field, the
+gravity, the radiative cooling, and the thermal conduction (including the
+effects of heat flux saturation).
+  RESULTS. The dynamics and stability of the accretion shock strongly depends
+on the plasma beta. In the case of shocks with beta > 10, violent outflows of
+shock-heated material (and possibly MHD waves) are generated at the base of the
+accretion column and strongly perturb the surrounding stellar atmosphere and
+the accretion column itself (modifying, therefore, the dynamics of the shock).
+In shocks with beta ~ 1, the post-shock region is efficiently confined by the
+magnetic field. The shock oscillations induced by cooling instability are
+strongly influenced by beta: for beta > 10, the oscillations may be rapidly
+dumped by the magnetic field, approaching a quasi-stationary state, or may be
+chaotic with no obvious periodicity due to perturbation of the stream induced
+by the post-shock plasma itself; for beta ~ 1 the oscillations are
+quasi-periodic, although their amplitude is smaller and the frequency higher
+than those predicted by 1D models.",0912.1799v1
+2010-03-01,"Optical initialization, readout and dynamics of a Mn spin in a quantum dot","We have investigated the spin preparation efficiency by optical pumping of
+individual Mn atoms embedded in CdTe/ZnTe quantum dots. Monitoring the time
+dependence of the intensity of the fluorescence during the resonant optical
+pumping process in individual quantum dots allows to directly probe the
+dynamics of the initialization of the Mn spin. This technique presents the
+convenience of including preparation and read-out of the Mn spin in the same
+step. Our measurements demonstrate that Mn spin initialization, at zero
+magnetic field, can reach an efficiency of 75% and occurs in the tens of
+\emph{ns} range when a laser resonantly drives at saturation one of the quantum
+dot transition. We observe that the efficiency of optical pumping changes from
+dot to dot and is affected by a magnetic field of a few tens of mT applied in
+Voigt or Faraday configuration. This is attributed to the local strain
+distribution at the Mn location which predominantly determines the dynamics of
+the Mn spin under weak magnetic field. The spectral distribution of the
+spin-flip scattered photons from quantum dots presenting a weak optical pumping
+efficiency reveals a significant spin relaxation for the exciton split in the
+exchange field of the Mn spin.",1003.0370v2
+2010-04-01,MRI channel flows in vertically-stratified models of accretion disks,"Simulations of the magnetorotational instability (MRI) in 'unstratified'
+shearing boxes exhibit powerful coherent flows, whereby the fluid vertically
+splits into countermoving planar jets or `channels'. Channel flows correspond
+to certain axisymmetric linear MRI modes, and their preponderance follows from
+the remarkable fact that they are approximate nonlinear solutions of the MHD
+equations in the limit of weak magnetic fields. We show in this paper,
+analytically and with one-dimensional numerical simulations, that this property
+is also shared by certain axisymmetric MRI modes in vertically-stratified
+shearing boxes. These channel flows rapidly capture significant amounts of
+magnetic and kinetic energy, and thus are vulnerable to secondary shear
+instabilities. We examine these parasites in the vertically stratified context,
+and estimate the maximum amplitudes that channels attain before they are
+destroyed. These estimates suggest that a dominant channel flow will usually
+drive the disk's magnetic field to thermal strengths. The prominence of these
+flows and their destruction place enormous demands on simulations, but channels
+in their initial stages also offer a useful check on numerical codes. These
+benchmarks are especially valuable given the increasing interest in the
+saturation of the stratified MRI. Lastly we speculate on the potential
+connection between 'run-away' channel flows and outburst behaviour in
+protostellar and dwarf nova disks.",1004.0109v1
+2010-05-09,Different response of the crystal structure to isoelectronic doping in BaFe2[As(1-x)P(x)]2 and [Ba(1-x)Sr(x)]Fe2As2,"Superconductivity up to 30 K in charge neutrally doped BaFe2[As(1-x)P(x)]2
+has been ascribed to chemical pressure, caused by the shrinking unit cell. But
+the latter induces no superconductivity in [Ba(1-x)Sr(x)]Fe2As2 in spite of the
+same volume range. We show that the spin-density-wave (SDW) state of BaFe2As2
+becomes suppressed in BaFe2[As(1-x)P(x)]2 by a subtle reorganization of the
+crystal structure, where arsenic and phosphorus are located at different
+coordinates z(As), z(P). High-resolution X-ray diffraction experiments with
+BaFe2[As(1-x)P(x)]2 single crystals reveal almost unchanged Fe-P bonds, but a
+contraction of the Fe-As bonds, which remain nearly unchanged in
+[Ba(1-x)Sr(x)]Fe2As2. Since the Fe-As bond length is a gauge for the magnetic
+moment, our results show why the SDW is suppressed by P-, but not by Sr-doping.
+Only the Fe-P interaction increases the width of the iron 3d bands, which
+destabilizes the magnetic SDW ground state. The simultaneous contraction of the
+Fe{As bonds is rather a consequence of the vanishing magnetism. Ordered
+structure models of BaFe2[As(1-x)P(x)]2 obtained by DFT calculations agree
+perfectly with the single-crystal X-ray structure determinations. The
+contraction of the Fe-As bonds saturates at doping levels above x = 0.3, which
+corrects the unreasonable linear decrease of the so-called pnictide height.",1005.1411v2
+2010-07-01,Exactly solvable mixed-spin Ising-Heisenberg diamond chain with the biquadratic interactions and single-ion anisotropy,"An exactly solvable variant of mixed spin-(1/2,1) Ising-Heisenberg diamond
+chain is considered. Vertical spin-1 dimers are taken as quantum ones with
+Heisenberg bilinear and biquadratic interactions and with single-ion
+anisotropy, while all interactions between spin-1 and spin-1/2 residing on the
+intermediate sites are taken in the Ising form. The detailed analysis of the
+$T=0$ ground state phase diagram is presented. The phase diagrams have shown to
+be rather rich, demonstrating large variety of ground states: saturated one,
+three ferrimagnetic with magnetization equal to 3/5 and another four
+ferrimagnetic ground states with magnetization equal to 1/5. There are also two
+frustrated macroscopically degenerated ground states which could exist at zero
+magnetic filed.
+  Solving the model exactly within classical transfer-matrix formalism we
+obtain an exact expressions for all thermodynamic function of the system. The
+thermodynamic properties of the model have been described exactly by exact
+calculation of partition function within the direct classical transfer-matrix
+formalism, the entries of transfer matrix, in their turn, contain the
+information about quantum states of vertical spin-1 XXZ dimer (eigenvalues of
+local hamiltonian for vertical link).",1007.0098v2
+2011-05-03,Universality of the Small-Scale Dynamo Mechanism,"We quantify possible differences between turbulent dynamo action in the Sun
+and the dynamo action studied in idealized simulations. For this purpose we
+compare Fourier-space shell-to-shell energy transfer rates of three
+incrementally more complex dynamo simulations: an incompressible, periodic
+simulation driven by random flow, a simulation of Boussinesq convection, and a
+simulation of fully compressible convection that includes physics relevant to
+the near-surface layers of the Sun. For each of the simulations studied, we
+find that the dynamo mechanism is universal in the kinematic regime because
+energy is transferred from the turbulent flow to the magnetic field from
+wavenumbers in the inertial range of the energy spectrum. The addition of
+physical effects relevant to the solar near-surface layers, including
+stratification, compressibility, partial ionization, and radiative energy
+transport, does not appear to affect the nature of the dynamo mechanism. The
+role of inertial-range shear stresses in magnetic field amplification is
+independent from outer-scale circumstances, including forcing and
+stratification. Although the shell-to-shell energy transfer functions have
+similar properties to those seen in mean-flow driven dynamos in each simulation
+studied, the saturated states of these simulations are not universal because
+the flow at the driving wavenumbers is a significant source of energy for the
+magnetic field.",1105.0546v1
+2011-06-17,Scaling the effect of the dipolar interactions on the ZFC/FC curves of random nanoparticle assemblies,"Zero Field Cooling (ZFC) and Field Cooling (FC) protocols are commonly used
+to investigate the properties of magnetic nanoparticle systems. For
+non-interacting conditions the particle properties are fairly well correlated
+with the shape of the ZFC/FC curves. However, that is not the case when
+significant dipolar interparticle interactions (DII) are present, what
+frequently occurs in experimental samples (e.g. aggregates in biological
+systems; or the dried powder often used for the ZFC/FC measurements). The
+purpose of this work is to show how the influence of the DII on the ZFC/FC
+curves, computed by the volume sample concentration c, can be described in a
+general way if scaled by the dimensionless parameter c_0 = 2K/M_S^2; where K
+and M_S are the anisotropy and saturation magnetization constants of the
+particles, respectively. This scaling parameter, which is straightforwardly
+derived from the energy equation governing the system, has an analogous meaning
+to the normalization of the external magnetic field H by the anisotropy field
+of the particles, H_A = 2K/M_S. We use a Monte Carlo technique to show how
+apparently different T_B vs. c curves of various particles types (where T_B is
+the blocking temperature), follow the same trend if scaling c/c_0.",1106.3403v2
+2011-07-13,Coils and transformers - often used but seldomly explained correctly,"The devices coil and transformer are subjects of interest in numerous
+schoolbooks, in introductory scientific textbooks of physics and engineering,
+and in laboratory courses at universities. Many descriptions, however, draw a
+somewhat distorted picture of the underlying physical mechanisms and provide
+half-knowledge or even clear misconceptions that should not be left uncommented
+and are therefore studied in detail:
+  (1) Primary and secondary voltage at a transformer have a different sign.
+  (2) Electromagnetic induction is the only mechanism of importance for coils
+and transformers.
+  (3) The terminal voltage at coils and transformers is compensated by the
+so-called ""induced voltage"" (emf), which explains why Kirchhoff's voltage law
+also applies to coils and transformers.
+  (4) The cores of coils and transformers are used for their ability to store
+energy. Energy is transported from the primary to the secondary coil within the
+magnetic core.
+  (5) The stray magnetic and electric fields are sencondary effects not having
+a major effect on energy transport.
+  (6) The higher the load current, the easier a transformer goes into
+saturation.
+  (7) The higher the number of turns at the primary coil, the larger the
+magnetic flux in the core.
+  (8) Transformers with cores having an air gap have a lower coupling factor,
+because the stray inductivity increases.
+  In the paper, the most important characteristics of coil and transformers are
+derived directly from Maxwell's equation for idealised conditions, and
+subsequently, the different misconceptions are discussed and corrected.",1107.2684v2
+2012-01-31,Local 2D Particle-in-cell simulations of the collisionless MRI,"The magnetorotational instability (MRI) is a crucial mechanism of angular
+momentum transport in a variety of astrophysical accretion disks. In systems
+accreting at well below the Eddington rate, such as the central black hole in
+the Milky Way (Sgr A*), the rate of Coulomb collisions between particles is
+very small, making the disk evolve essentially as a collisionless plasma. We
+present a nonlinear study of the collisionless MRI using first-principles
+particle-in-cell (PIC) plasma simulations. In this initial study we focus on
+local two-dimensional (axisymmetric) simulations, deferring more realistic
+three-dimensional simulations to future work. For simulations with net vertical
+magnetic flux, the MRI continuously amplifies the magnetic field until the
+Alfv\'en velocity, v_A, is comparable to the speed of light, c (independent of
+the initial value of v_A/c). This is consistent with the lack of saturation of
+MRI channel modes in analogous axisymmetric MHD simulations. The amplification
+of the magnetic field by the MRI generates a significant pressure anisotropy in
+the plasma (with the perpendicular pressure being larger than the parallel
+pressure). We find that this pressure anisotropy in turn excites mirror modes
+and that the volume averaged pressure anisotropy remains near the threshold for
+mirror mode excitation. Particle energization is due to both reconnection and
+viscous heating associated with the pressure anisotropy. Reconnection produces
+a distinctive power-law component in the energy distribution function of the
+particles, indicating the likelihood of non-thermal ion and electron
+acceleration in collisionless accretion disks. This has important implications
+for interpreting the observed emission -- from the radio to the gamma-rays --
+of systems such as Sgr A*.",1201.6407v1
+2012-11-15,Alignment of Magnetized Accretion Disks and Relativistic Jets with Spinning Black Holes,"Accreting black holes (BHs) produce intense radiation and powerful
+relativistic jets, which are affected by the BH's spin magnitude and direction.
+While thin disks might align with the BH spin axis via the Bardeen-Petterson
+effect, this does not apply to jet systems with thick disks. We used fully
+three-dimensional general relativistic magnetohydrodynamical simulations to
+study accreting BHs with various BH spin vectors and disk thicknesses with
+magnetic flux reaching saturation. Our simulations reveal a ""magneto-spin
+alignment"" mechanism that causes magnetized disks and jets to align with the BH
+spin near BHs and further away to reorient with the outer disk. This mechanism
+has implications for the evolution of BH mass and spin, BH feedback on host
+galaxies, and resolved BH images for SgrA* and M87.",1211.3651v1
+2012-12-13,Diffusive Shock Acceleration at Cosmological Shock Waves,"We reexamine nonlinear diffusive shock acceleration (DSA) at cosmological
+shocks in the large scale structure of the Universe, incorporating
+wave-particle interactions that are expected to operate in collisionless
+shocks. Adopting simple phenomenological models for magnetic field
+amplification (MFA) by cosmic-ray (CR) streaming instabilities and Alfv'enic
+drift, we perform kinetic DSA simulations for a wide range of sonic and
+Alfv'enic Mach numbers and evaluate the CR injection fraction and acceleration
+efficiency. In our DSA model the CR acceleration efficiency is determined
+mainly by the sonic Mach number Ms, while the MFA factor depends on the
+Alfv'enic Mach number and the degree of shock modification by CRs. We show that
+at strong CR modified shocks, if scattering centers drift with an effective
+Alfv'en speed in the amplified magnetic field, the CR energy spectrum is
+steepened and the acceleration efficiency is reduced significantly, compared to
+the cases without such effects. As a result, the postshock CR pressure
+saturates roughly at ~ 20 % of the shock ram pressure for strong shocks with
+Ms>~ 10. In the test-particle regime (Ms<~ 3), it is expected that the magnetic
+field is not amplified and the Alfv'enic drift effects are insignificant,
+although relevant plasma physical processes at low Mach number shocks remain
+largely uncertain.",1212.3246v1
+2013-02-06,Magnetic irreversibility in ultrafine ZnFe2O4 partices,"Pure ultrafine ZnFe2O4 particles have been obtained from mechanosynthesis of
+the ZnO and Fe2O3 oxides. The average grain diameter was estimated from x-ray
+diffraction to be <d> = 36(6) nm. Refinement of neutron diffraction (ND) data
+showed that the resulting cubic spinel structure is oxygen-deficient, with ~7%
+of Fe3+ ions occupying the tetrahedral A sites. Magnetization curves taken at
+4.2 K showed absence of saturation up to fields H = 9 Tesla, associated to a
+spin-canted produced by the milling process. Field-cooled (FC) and
+zero-field-cooled (ZFC) curves showed irreversible behavior extending well
+above room temperature, which is associated to spin disorder. Annealing samples
+at 300 {\deg}C yields an average grain size <d> = 50(6) nm, and ~16% of Fe3+
+ions at A sites. Partial oxygen recovery is also deduced from neutron data
+refinement in annealed samples. Concurrently, decrease of magnetic
+irreversibility is noticed, assigned to partial recovery of the collinear spin
+structure. Complex M\""ossbauer spectra were observed at room temperature and 80
+K, with broad hyperfine field distributions spanning from ~10 T to ~40 T. At T
+= 4.2 K, hyperfine field distributions indicate high disorder in Fe local
+environments. The above data suggest the existence of Fe-rich clusters,
+yielding strong superexchange interactions between Fe ions at A and B sites of
+the spinel structure.",1302.1276v1
+2013-06-25,Magnetic self-organisation in Hall-dominated magnetorotational turbulence,"The magnetorotational instability (MRI) is the most promising mechanism by
+which angular momentum is efficiently transported outwards in astrophysical
+discs. However, its application to protoplanetary discs remains problematic.
+These discs are so poorly ionised that they may not support magnetorotational
+turbulence in regions referred to as `dead zones'. It has recently been
+suggested that the Hall effect, a non-ideal magnetohydrodynamic (MHD) effect,
+could revive these dead zones by enhancing the magnetically active column
+density by an order of magnitude or more. We investigate this idea by
+performing local, three-dimensional, resistive Hall-MHD simulations of the MRI
+in situations where the Hall effect dominates over Ohmic dissipation. As
+expected from linear stability analysis, we find an exponentially growing
+instability in regimes otherwise linearly stable in resistive MHD. However,
+instead of vigorous and sustained magnetorotational turbulence, we find that
+the MRI saturates by producing large-scale, long-lived, axisymmetric structures
+in the magnetic and velocity fields. We refer to these structures as zonal
+fields and zonal flows, respectively. Their emergence causes a steep reduction
+in turbulent transport by at least two orders of magnitude from extrapolations
+based upon resistive MHD, a result that calls into question contemporary models
+of layered accretion. We construct a rigorous mean-field theory to explain this
+new behaviour and to predict when it should occur. Implications for
+protoplanetary disc structure and evolution, as well as for theories of planet
+formation, are briefly discussed.",1306.5887v1
+2013-07-05,The influence of Strong Magnetic Field in Hyperonic Neutron Stars,"The physics of neutron stars leads historically towards Landau's speculation.
+Even before the discovery of the neutron, he postulated the possible existence
+of stars more compact than white dwarfs, containing matter of the order of
+nuclear density. From a modern point of view neutron stars are compact objects
+maintained by the equilibrium between gravity and the degeneracy pressure of
+the fermions together with a strong nuclear repulsion force due to the high
+density reached in their interior. While the physics in the vicinity of nuclear
+saturation density is well know from phenomenology, the physics of ultra-dense
+nuclear matter is still an open puzzle. In this work we study dense nuclear
+matter within a relativistic model, allowing hyperons to be present through
+beta equilibrium. The presence of hyperons is justifiable since the
+constituents of neutron stars are fermions. So, according to the Pauli
+principle, as the baryon density increases, so do the Fermi momentum and the
+Fermi energy. On the other hand, this hyperonic matter softens the equation of
+state (EoS) and a recent measurement of pulsar PSR J1614-2230 implies that the
+EoS has to be stiff enough to produce a 2.0 $M_{\odot}$ pulsar. We also
+consider Duncan's magnetar ideas and study the influence of strong magnetic
+fields on the EoS. We see that a strong magnetic field produces very massive
+neutron stars, in agreement with the astronomical observations.",1307.1691v1
+2013-08-06,Electronic structure and magnetic properties of Gd-doped and Eu-rich EuO,"The effects of Gd doping and O vacancies on the magnetic interaction and
+Curie temperature of EuO are studied using first-principles calculations.
+Linear response calculations in the virtual crystal approximation show a broad
+maximum in the Curie temperature as a function of doping, which results from
+the combination of the saturating contribution from indirect exchange and a
+decreasing contribution from the f-d hopping mechanism. Non-Heisenberg
+interaction at low doping levels and its effect on the Curie temperature are
+examined. The electronic structure of a substitutional Gd and of an O vacancy
+in EuO are evaluated. When the 4f spins are disordered, the impurity state goes
+from single to double occupation, but correlated bound magnetic polarons are
+not ruled out. At higher vacancy concentrations typical for Eu-rich EuO films,
+the impurity states broaden into bands and remain partially filled. To go
+beyond the homogeneous doping picture, magnetostructural cluster expansions are
+constructed, which describe the modified exchange parameters near Gd dopants or
+O vacancies. Thermodynamic properties are studied using Monte Carlo
+simulations. The Curie temperature for Gd-doped EuO agrees with the results of
+the virtual crystal approximation and shows a maximum of about 150 K. At 3.125%
+vacancy concentration the Curie temperature increases to 120 K, consistent with
+experimental data for Eu-rich film samples.",1308.1223v1
+2013-11-27,"Hall Effect in Neutron Star Crusts: Evolution, Endpoint and Dependence on Initial Conditions","We present new simulations of the evolution of axially symmetric magnetic
+fields in neutron star crusts under the influence of the Hall effect and
+subdominant Ohmic dissipation. In the Hall effect, differential rotation of the
+electron fluid generates toroidal field by winding of the poloidal field. For
+this reason, we focus on the influence of the initial choice of the electron
+angular velocity profile on the subsequent and long term magnetic evolution.
+Whereas previous simulations have generally chosen angular velocities
+increasing outwards, corresponding to the lowest order Ohmic mode in the crust,
+a more realistic choice is an angular velocity decreasing outwards,
+corresponding to the MHD equilibrium field that is likely present at the time
+of crust formation. We find that the evolution passes through three basic
+phases. The early evolution is a response to the initial conditions. During the
+second phase the field consists of poloidal and toroidal components which
+eventually relax to an isorotation state in which the angular velocity of the
+electrons becomes constant along poloidal magnetic field lines, causing Hall
+evolution to saturate. In the third phase the field dissipates slowly while
+maintaining isorotation. We discuss the implications for the long term field
+structure and observable properties of isolated neutron stars.",1311.7004v1
+2013-11-28,Predictive Scaling Laws for Spherical Rotating Dynamos,"State of the art numerical models of the Geodynamo are still performed in a
+parameter regime extremely remote from the values relevant to the physics of
+the Earth's core. In order to establish a connection between dynamo modeling
+and the geophysical motivation, {it is necessary to use} scaling laws. Such
+scaling laws establish the dependence of essential quantities (such as the
+magnetic field strength) on measured or controlled quantities. They allow for a
+direct confrontation of advanced models with geophysical {constraints}.
+  (...)
+  We show that previous empirical scaling laws for the magnetic field strength
+essentially reflect the statistical balance between energy production and
+dissipation for saturated dynamos. Such power based scaling laws are thus
+necessarily valid for any dynamo in statistical equilibrium and applicable to
+any numerical model, irrespectively of the dynamo mechanism.
+  We show that direct numerical fits can provide contradictory results owing to
+biases in the parameters space covered in the numerics and to the role of a
+priori hypothesis on the fraction of ohmic dissipation.
+  We introduce predictive scaling laws, i.e. relations involving input
+parameters of the governing equations only. We guide our reasoning on physical
+considerations. We show that our predictive scaling laws can properly describe
+the numerical database and reflect the dominant forces balance at work in these
+numerical simulations. We highlight the dependence of the magnetic field
+strength on the rotation rate. Finally, our results stress that available
+numerical models operate in a viscous dynamical regime, which is not relevant
+to the Earth's core.",1311.7395v2
+2014-07-03,Hyperfine coupling and spin polarization in the bulk of the topological insulator Bi$_2$Se$_3$,"Nuclear magnetic resonance (NMR) and transport measurements have been
+performed at high magnetic fields and low temperatures in a series of $n$-type
+Bi$_{2}$Se$_{3}$ crystals. In low density samples, a complete spin polarization
+of the electronic system is achieved, as observed from the saturation of the
+isotropic component of the $^{209}$Bi NMR shift above a certain magnetic field.
+The corresponding spin splitting, defined in the phenomenological approach of a
+3D electron gas with a large (spin-orbit-induced) effective $g$-factor, scales
+as expected with the Fermi energy independently determined by simultaneous
+transport measurements. Both the effective electronic $g$-factor and the
+""contact"" hyperfine coupling constant are precisely determined. The magnitude
+of this latter reveals a non negligible $s$-character of the electronic wave
+function at the bottom of the conduction band. Our results show that the bulk
+electronic spin polarization can be directly probed via NMR and pave the way
+for future NMR investigations of the electronic states in Bi-based topological
+insulators.",1407.1040v2
+2014-07-30,Exact ground states of a spin-1/2 Ising-Heisenberg model on the Shastry-Sutherland lattice in a magnetic field,"Exact ground states of a spin-1/2 Ising-Heisenberg model on the
+Shastry-Sutherland lattice with Heisenberg intra-dimer and Ising inter-dimer
+couplings are found by two independent rigorous procedures. The first method
+uses a unitary transformation to establish a mapping correspondence with an
+effective classical spin model, while the second method relies on the
+derivation of an effective hard-core boson model by continuous unitary
+transformations. Both methods lead to equivalent effective Hamiltonians
+providing a convincing proof that the spin-1/2 Ising-Heisenberg model on the
+Shastry-Sutherland lattice exhibits a zero-temperature magnetization curve with
+just two intermediate plateaus at one-third and one-half of the saturation
+magnetization, which correspond to stripe and checkerboard orderings of
+singlets and polarized triplets, respectively. The nature of the remarkable
+stripe order relevant to the one-third plateau is thoroughly investigated with
+the help of the corresponding exact eigenvector. The rigorous results for the
+spin-1/2 Ising-Heisenberg model on the Shastry-Sutherland lattice are compared
+with the analogous results for the purely classical Ising and fully quantum
+Heisenberg models. Finally, we discuss to what extent the critical fields of
+SrCu2(BO3)2 and (CuCl)Ca2Nb3O10 can be described within the suggested
+Ising-Heisenberg model.",1407.8229v2
+2014-08-20,Spontaneous chiral symmetry breaking and the Chiral Magnetic Effect for interacting Dirac fermions with chiral imbalance,"We report on a mean-field study of spontaneous breaking of chiral symmetry
+for Dirac fermions with contact interactions in the presence of chiral
+imbalance, which is modelled by nonzero chiral chemical potential. We point out
+that chiral imbalance lowers the vacuum energy of Dirac fermions, which leads
+to the increase of the renormalized chiral chemical potential upon chiral
+symmetry breaking. The critical coupling strength for the transition to the
+broken phase is slightly lowered as the chiral chemical potential is increased,
+and the transition itself becomes milder. Furthermore, we study the chiral
+magnetic conductivity in different phases and find that it grows both in the
+perturbative weak-coupling regime and in the strongly coupled phase with broken
+chiral symmetry. In the strong coupling regime the chiral magnetic effect is
+saturated by vector-like bound states (vector mesons) with mixed transverse
+polarizations. General pattern of meson mixing in the presence of chiral
+imbalance is also considered. We discuss the relevance of our study for Weyl
+semimetals and strongly interacting QCD matter. Finally, we comment on the
+ambiguity of the regularization of the vacuum energy of Dirac fermions in the
+presence of chirality imbalance.",1408.4573v2
+2014-08-27,Dynamics of a mesoscopic nuclear spin ensemble interacting with an optically driven electron spin,"The ability to discriminate between simultaneously occurring noise sources in
+the local environment of semiconductor InGaAs quantum dots, such as electric
+and magnetic field fluctuations, is key to understanding their respective
+dynamics and their effect on quantum dot coherence properties. We present a
+discriminatory approach to all-optical sensing based on two-color resonance
+fluorescence of a quantum dot charged with a single electron. Our measurements
+show that local magnetic field fluctuations due to nuclear spins in the absence
+of an external magnetic field are described by two correlation times, both in
+the microsecond regime. The nuclear spin bath dynamics show a strong dependence
+on the strength of resonant probing, with correlation times increasing by a
+factor of four as the optical transition is saturated. We interpret the
+behavior as motional averaging of both the Knight field of the resident
+electron spin and the hyperfine-mediated nuclear spin-spin interaction due to
+optically-induced electron spin flips.",1408.6437v2
+2014-11-11,Relaxation mechanisms affecting magneto-optical resonances in an extremely thin cell: experiment and theory for the cesium D$_1$ line,"We have measured magneto-optical signals obtained by exciting the $D_1$ line
+of cesium atoms confined to an extremely thin cell (ETC), whose walls are
+separated by less than one micrometer, and developed an improved theoretical
+model to describe these signals with experimental precision. The theoretical
+model was based on the optical Bloch equations and included all neighboring
+hyperfine transitions, the mixing of the magnetic sublevels in an external
+magnetic field, and the Doppler effect, as in previous studies. However, in
+order to model the extreme conditions in the ETC more realistically, the model
+was extended to include a unified treatment of transit relaxation and wall
+collisions with relaxation rates that were obtained directly from the thermal
+velocities of the atoms and the length scales involved. Furthermore, the
+interaction of the atoms with different regions of the laser beam were modeled
+separately to account for the varying laser beam intensity over the beam
+profile as well as saturation effects that become important near the center of
+the beam at the relatively high laser intensities used during the experiments
+in order to obtain measurable signals. The model described the experimentally
+measured signals for laser intensities for magnetic fields up to 55~G and laser
+intensities up to 1~W/cm$^2$ with excellent agreement.",1411.2750v1
+2014-12-04,Acoustomagnetoelectric Effect in Graphene Nanoribbon in the Presence of External Electric and Magnetic Field,"The Acoustomagnetoelectric Effect (AME) in Graphene Nanoribbon (GNR) was
+theoretically studied using the Boltzmann kinetic equation. On open circuit,
+the general formular for Surface Acoustomagnetoelectric field
+($\vec{E}_{SAME}$) in GNR with energy dispersion $\varepsilon(p)$ near the
+Fermi point was calculated. The $E_{SAME}$ was found to depend on the magnetic
+strength ($\eta$), $\alpha$ = ${\hbar \omega_q}/{E_g}$ and the energy gap
+($E_g$). The expression for $\vec{E}_{SAME}$ was analyzed numerically for
+varying width of GNR, magnetic strength ($\eta$) and $\alpha$ at different
+sub-bands indices ($p_i$). It was noted that the dependence of $\vec{E}_{SAME}$
+on the width of GNR increased to a saturation point of approximately
+$15$Vcm$^{-1}$ and remained constant. For $E_{SAME}$ versus $\eta$, the
+$E_{SAME}$ increases rapidly to a maximum point and then decayed to a constant
+minimum value. The graph was modulated either by varying the width of GNR or
+the sub-band index $p_i$ with an inversion occurring at $p_i = 6$. The
+dependence of $E_{SAME}$ versus $\alpha$ was analyzed. The $E_{SAME}$ was
+constant up to a point and sharply increased asymptotically at approximately
+$\alpha = 1$. A $3$D graph of $\vec{E}_{SAME}$ with $\eta$ and width is also
+presented. This study is relevant for investigating the properties of GNR.",1412.1678v5
+2014-12-15,The Mass-Dependence of Angular Momentum Evolution in Sun-Like Stars,"To better understand the observed distributions of rotation rate and magnetic
+activity of sun-like and low-mass stars, we derive a physically motivated
+scaling for the dependence of the stellar-wind torque on Rossby number. The
+torque also contains an empirically-derived scaling with stellar mass (and
+radius), which provides new insight into the mass-dependence of stellar
+magnetic and wind properties. We demonstrate that this new formulation explains
+why the lowest mass stars are observed to maintain rapid rotation for much
+longer than solar-mass stars, and simultaneously, why older populations exhibit
+a sequence of slowly rotating stars, in which the low-mass stars rotate more
+slowly than solar-mass stars. The model also reproduces some previously
+unexplained features in the period-mass diagram for the Kepler field, notably:
+the particular shape of the ""upper envelope"" of the distribution, suggesting
+that ~95% of Kepler field stars with measured rotation periods are younger than
+~4 Gyr; and the shape of the ""lower envelope,"" corresponding to the location
+where stars transition between magnetically saturated and unsaturated regimes.",1412.4786v1
+2015-01-22,High spin polarization and large spin splitting in equiatomic quaternary CoFeCrAl Heusler alloy,"In this paper, we investigate CoFeCrAl alloy by means of various experimental
+techniques and ab-initio calculations to look for half-metallic nature. The
+alloy is found to exist in the cubic Heusler structure, with presence of B2
+ordering. Saturation magnetization (MS) value of about 2 Bohr magneton/f.u. is
+observed at 8 K under ambient pressure, which is in good agreement with the
+Slater-Pauling rule. MS values are found to be independent of pressure, which
+is a prerequisite for half-metals. The ab-initio electronic structure
+calculations predict half-metallic nature for the alloy with a spin slitting
+energy of 0.31 eV. Importantly, this system shows a high current spin
+polarization value of 0.67 [with error of 0.02], as deduced from the point
+contact Andreev reflection (PCAR) measurements. Linear dependence of electrical
+resistivity with temperature indicates the possibility of reasonably high spin
+polarization at elevated temperatures (~150 K) as well. All these suggest that
+CoFeCrAl is a promising material for the spintronic devices.",1501.05599v1
+2015-02-08,Tuning the scattering mechanism in three-dimensional Dirac semimetal Cd$_{3}$As$_{2}$,"To probe the charge scattering mechanism in Cd$_{3}$As$_{2}$ single crystal,
+we have analyzed the temperature and magnetic field dependence of the Seebeck
+coefficient ($S$). The large saturation value of $S$ at high field clearly
+demonstrates the linear energy dispersion of three-dimensional Dirac fermion. A
+wide tunability of the charge scattering mechanism has been realized by varying
+the strength of the magnetic field and carrier density via In doping. With the
+increase in magnetic field, the scattering time crosses over from being nearly
+energy independent to a regime of linear dependence. On the other hand, the
+scattering time enters into the inverse energy-dependent regime and the Fermi
+surface strongly modifies with 2\% In doping at Cd site. With further increase
+in In content from 2 to 4\%, we did not observe any Shubnikov-de Haas
+oscillation up to 9 T field, but the magnetoresistance is found to be quite
+large as in the case of undoped sample.",1502.02264v5
+2015-02-24,$S$ = 1/2 ferromagnetic-antiferromagnetic alternating Heisenberg chain in a zinc-verdazyl complex,"We successfully synthesized the zinc-verdazyl complex
+[Zn(hfac)$_2$]$\cdot$($o$-Py-V) [hfac = 1,1,1,5,5,5-hexafluoroacetylacetonate;
+$o$-Py-V = 3-(2-pyridyl)-1,5-diphenylverdazyl], which is an ideal model
+compound with an $S$ = 1/2 ferromagnetic-antiferromagnetic alternating
+Heisenberg chain (F-AF AHC). $Ab$ $initio$ molecular orbital (MO) calculations
+indicate that two dominant interactions $J_{\rm{F}}$ and $J_{\rm{AF}}$ form the
+$S=1/2$ F-AF AHC in this compound. The magnetic susceptibility and magnetic
+specific heat of the compound exhibit thermally activated behavior below
+approximately 1 K. Furthermore, its magnetization curve is observed up to the
+saturation field and directly indicates a zero-field excitation gap of 0.5 T.
+These experimental results provide evidence for the existence of a Haldane gap.
+We successfully explain the results in terms of the $S=1/2$ F-AF AHC through
+quantum Monte Carlo calculations with $|J_{\rm{AF}}/J_{\rm{F}}|$ = 0.22. The
+$ab$ $initio$ MO calculations also indicate a weak AF interchain interaction
+$J'$ and that the coupled F-AF AHCs form a honeycomb lattice. The $J'$
+dependence of the Haldane gap is calculated, and the actual value of $J'$ is
+determined to be less than 0.01$|J_{\rm{F}}|$.",1502.06804v1
+2015-05-07,Spin and charge density waves in the Lieb lattice,"We study the mean-field phase diagram of the two-dimensional (2D) Hubbard
+model in the Lieb lattice allowing for spin and charge density waves. Previous
+studies of this diagram have shown that the mean-field magnetization
+surprisingly deviates from the value predicted by Lieb's theorem
+\cite{Lieb1989} as the on-site repulsive Coulomb interaction ($U$) becomes
+smaller \cite{Gouveia2015}. Here, we show that in order for Lieb's theorem to
+be satisfied, a more complex mean-field approach should be followed in the case
+of bipartite lattices or other lattices whose unit cells contain more than two
+types of atoms. In the case of the Lieb lattice, we show that, by allowing the
+system to modulate the magnetization and charge density between sublattices,
+the difference in the absolute values of the magnetization of the sublattices,
+$m_{\text{Lieb}}$, at half-filling, saturates at the exact value $1/2$ for any
+value of $U$, as predicted by Lieb. Additionally, Lieb's relation,
+$m_{\text{Lieb}}=1/2$, is verified approximately for large $U$, in the $n \in
+[2/3,4/3]$ range. This range includes not only the ferromagnetic region of the
+phase diagram of the Lieb lattice (see Ref.~\onlinecite{Gouveia2015}), but also
+the adjacent spiral regions. In fact, in this lattice, below or at
+half-filling, $m_{\text{Lieb}}$ is simply the filling of the quasi-flat bands
+in the mean-field energy dispersion both for large and small $U$.",1505.01656v1
+2015-06-04,Manipulation of the spin helix in FeGe thin films and FeGe/Fe multilayers,"Magnetic materials without structural inversion symmetry can display the
+Dzyaloshinskii-Moriya interaction, which manifests itself as chiral magnetic
+ground states. These chiral states can interact in complex ways with applied
+fields and boundary conditions provided by finite sample sizes that are of the
+order of the lengthscale of the chiral states. Here we study epitaxial thin
+films of FeGe with a thickness close to the helix pitch of the helimagnetic
+ground state, which is about 70 nm, by conventional magnetometry and polarized
+neutron reflectometry. We show that the helix in an FeGe film reverses under
+the application of a field by deforming into a helicoidal form, with twists in
+the helicoid being forced out of the film surfaces on the way to saturation. An
+additional boundary condition was imposed by exchange coupling a ferromagnetic
+Fe layer to one of the interfaces of an FeGe layer. This forces the FeGe spins
+at the interface to point in the same direction as the Fe, preventing node
+expulsion and giving a handle by which the reversal of the helical magnet may
+be controlled.",1506.01575v1
+2015-08-04,An Extended Magnetohydrodynamics Model for Relativistic Weakly Collisional Plasmas,"Black holes that accrete far below the Eddington limit are believed to
+accrete through a geometrically thick, optically thin, rotationally supported
+plasma that we will refer to as a radiatively inefficient accretion flow
+(RIAF). RIAFs are typically collisionless in the sense that the Coulomb mean
+free path is large compared to $GM/c^2$, and relativistically hot near the
+event horizon. In this paper we develop a phenomenological model for the plasma
+in RIAFs, motivated by the application to sources such as Sgr A* and M87. The
+model is derived using Israel-Stewart theory, which considers deviations up to
+second order from thermal equilibrium, but modified for a magnetized plasma.
+This leads to thermal conduction along magnetic field lines and a difference in
+pressure, parallel and perpendicular to the field lines (which is equivalent to
+anisotrotropic viscosity). In the non-relativistic limit, our model reduces to
+the widely used Braginskii theory of magnetized, weakly collisional plasmas. We
+compare our model to the existing literature on dissipative relativistic
+fluids, describe the linear theory of the plasma, and elucidate the physical
+meaning of the free parameters in the model. We also describe limits of the
+model when the conduction is saturated and when the viscosity implies a large
+pressure anisotropy. In future work, the formalism developed in this paper will
+be used in numerical models of RIAFs to assess the importance of non-ideal
+processes for the dynamics and radiative properties of slowly accreting black
+holes.",1508.00878v1
+2015-08-06,The energy budget of stellar magnetic fields,"Spectropolarimetric observations have been used to map stellar magnetic
+fields, many of which display strong bands of azimuthal fields that are
+toroidal. A number of explanations have been proposed to explain how such
+fields might be generated though none are definitive. In this paper, we examine
+the toroidal fields of a sample of 55 stars with magnetic maps, with masses in
+the range 0.1-1.5$\,{\rm M}_\odot$. We find that the energy contained in
+toroidal fields has a power law dependence on the energy contained in poloidal
+fields. However the power index is not constant across our sample, with stars
+less and more massive than 0.5$\,{\rm M}_\odot$ having power indices of
+0.72$\pm$0.08 and 1.25$\pm$0.06 respectively. There is some evidence that these
+two power laws correspond to stars in the saturated and unsaturated regimes of
+the rotation-activity relation. Additionally, our sample shows that strong
+toroidal fields must be generated axisymmetrically. The latitudes at which
+these bands appear depend on the stellar rotation period with fast rotators
+displaying higher latitude bands than slow rotators. The results in this paper
+present new constraints for future dynamo studies.",1508.01403v1
+2015-10-30,"Feedback Regulated Turbulence, Magnetic Fields, and Star Formation Rates in Galactic Disks","We use three-dimensional magnetohydrodynamic (MHD) simulations to investigate
+the quasi-equilibrium states of galactic disks regulated by star formation
+feedback. We incorporate effects from massive-star feedback via time-varying
+heating rates and supernova (SN) explosions. We find that the disks in our
+simulations rapidly approach a quasi-steady state that satisfies vertical
+dynamical equilibrium. The star formation rate (SFR) surface density
+self-adjusts to provide the total momentum flux (pressure) in the vertical
+direction that matches the weight of the gas. We quantify feedback efficiency
+by measuring feedback yields, \eta_c\equiv P_c/\Sigma_SFR (in suitable units),
+for each pressure component. The turbulent and thermal feedback yields are the
+same for HD and MHD simulations, \eta_th~1 and \eta_ turb~4, consistent with
+the theoretical expectations. In MHD simulations, turbulent magnetic fields are
+rapidly generated by turbulence, and saturate at a level corresponding to
+\eta_mag,t~1. The presence of magnetic fields enhances the total feedback yield
+and therefore reduces the SFR, since the same vertical support can be supplied
+at a smaller SFR. We suggest further numerical calibrations and observational
+tests in terms of the feedback yields.",1511.00018v1
+2016-03-03,Classical impurities and boundary Majorana zero modes in quantum chains,"We study the response of classical impurities in quantum Ising chains. The Z2
+degeneracy they entail renders the existence of two decoupled Majorana modes at
+zero energy an exact property of a finite system at arbitrary values of its
+bulk parameters. We trace the evolution of these modes across the transition
+from the disordered phase to the ordered one and analyze the concomitant
+qualitative changes of local magnetic properties of an isolated impurity. In
+the disordered phase, the two ground states differ only close to the impurity,
+and they are related by the action of an explicitly constructed quasi-local
+operator. In this phase the local transverse spin susceptibility follows a
+Curie law. The critical response of a boundary impurity is logarithmically
+divergent and maps to the two-channel Kondo problem, while it saturates for
+critical bulk impurities, as well as in the ordered phase. The results for the
+Ising chain translate to the related problem of a resonant level coupled to a
+1d p-wave superconductor or a Peierls chain, whereby the magnetic order is
+mapped to topological order. We find that the topological phase always exhibits
+a continuous impurity response to local fields as a result of the level
+repulsion of local levels from the boundary Majorana zero mode. In contrast,
+the disordered phase generically features a discontinuous magnetization or
+charging response. This difference constitutes a general thermodynamic
+fingerprint of topological order in phases with a bulk gap.",1603.01037v1
+2016-06-23,Resistive properties and phase diagram of the organic antiferromagnetic metal $κ$-(BETS)$_2$FeCl$_4$,"The low-temperature electronic state of the layered organic charge-transfer
+salt $\kappa$-(BETS)$_2$FeCl$_4$ was probed by interlayer electrical resistance
+measurements under magnetic field. Both above and below
+$T_{\mathrm{N}}=0.47\,$K, the temperature of antiferromagnetic ordering of
+$3d$-electron spins of Fe$^{3+}$ localized in the insulating anion layers, a
+non-saturating linear $R(T)$ dependence has been observed. A weak
+superconducting signal has been detected in the antiferromagnetic state, at
+temperatures $\leq 0.2\,$K. Despite the very high crystal quality, only a tiny
+fraction of the sample appears to be superconducting. Besides a small kink
+feature in the resistivity, the impact of the antiferromagnetic ordering of
+localized Fe$^{3+}$ spins on the conduction $\pi$-electron system is clearly
+manifested in the Fermi surface reconstruction, as evidenced by Shubnikov-de
+Haas oscillations. The ""magnetic field -- temperature"" phase diagrams for the
+field directions parallel to each of the three principal crystal axes have been
+determined. For magnetic field along the easy axis a spin-flop transition has
+been found. Similarities and differences between the present material and the
+sister compound $\kappa$-(BETS)$_2$FeBr$_4$ are discussed.",1606.07331v3
+2016-06-23,A coupled $2\times2$D Babcock-Leighton solar dynamo model. II. Reference dynamo solutions,"In this paper we complete the presentation of a new hybrid $2\times2$D flux
+transport dynamo (FTD) model of the solar cycle based on the Babcock-Leighton
+mechanism of poloidal magnetic field regeneration via the surface decay of
+bipolar magnetic regions (BMRs). This hybrid model is constructed by allowing
+the surface flux transport (SFT) simulation described in Lemerle et al. 2015 to
+provide the poloidal source term to an axisymmetric FTD simulation defined in a
+meridional plane, which in turn generates the BMRs required by the SFT. A key
+aspect of this coupling is the definition of an emergence function describing
+the probability of BMR emergence as a function of the spatial distribution of
+the internal axisymmetric magnetic field. We use a genetic algorithm to
+calibrate this function, together with other model parameters, against observed
+cycle 21 emergence data. We present a reference dynamo solution reproducing
+many solar cycle characteristics, including good hemispheric coupling, phase
+relationship between the surface dipole and the BMR-generating internal field,
+and correlation between dipole strength at cycle maximum and peak amplitude of
+the next cycle. The saturation of the cycle amplitude takes place through the
+quenching of the BMR tilt as a function of the internal field. The observed
+statistical scatter about the mean BMR tilt, built into the model, acts as a
+source of stochasticity which dominates amplitude fluctuations. The model thus
+can produce Dalton-like epochs of strongly suppressed cycle amplitude lasting a
+few cycles and can even shut off entirely following an unfavorable sequence of
+emergence events.",1606.07375v3
+2016-09-15,Ferromagnetism and the Effect of Free Charge Carriers on Electric Polarization in Y_2NiMnO_6 Double Perovskite,"The double perovskite Y_2NiMnO_6 displays ferromagnetic transition at Tc = 81
+K. The ferromagnetic order at low temperature is confirmed by the saturation
+value of magnetization (M_s) and also, validated by the refined ordered
+magnetic moment values extracted from neutron powder diffraction data at 10 K.
+This way, the dominant Mn4+ and Ni2+ cationic ordering is confirmed. The
+cation-ordered P 21/n nuclear structure is revealed by neutron powder
+diffraction studies at 300 and 10 K. Analysis of frequency dependent dielectric
+constant and equivalent circuit analysis of impedance data takes into account
+the bulk contribution to total dielectric constant. This reveals an anomaly
+which coincides with the ferromagnetic transition temperature (T_c).
+Pyrocurrent measurements register a current flow with onset near Tc and a peak
+at 57 K that shifts with temperature ramp rate. The extrinsic nature of the
+observed pyrocurrent is established by employing a special protocol
+measurement. It is realized that the origin is due to re-orientation of
+electric dipoles created by the free charge carriers and not by spontaneous
+electric polarization at variance with recently reported magnetism-driven
+ferroelectricity in this material",1609.04511v1
+2016-12-20,Magnons in a two dimensional transverse field XXZ model,"The XXZ model on a square lattice in the presence of a transverse magnetic
+field is studied within the spin wave theory to investigate the resulting
+canted antiferromagnet. The small and large field regimes are probed separately
+both for easy-axis and easy-plane scenarios which reveal an unentangled
+factorized ground state at an intermediate value of the field. Goldstone modes
+are obtained for the field-free $XY$ antiferromagnet as well as for the
+isotropic antiferromagnet with field up to its saturation value. Moreover, for
+an easy-plane anisotropy, we find that there exists a non-zero field, where
+magnon degeneracy appears as a result of restoration of an U(1) sublattice
+symmetry and that, across that field, there occurs a magnon band crossing. For
+completeness, we then obtain the system phase diagram for $S=1/2$ via large
+scale quantum Monte Carlo simulations using the stochastic series expansion
+technique. Our numerical method is based on a quantization of spin along the
+direction of the applied magnetic field and does not suffer from a
+sign-problem, unlike comparable algorithms based on a spin quantization along
+the axis of anisotropy. With this formalism, we are also able to obtain powder
+averages of the transverse and longitudinal magnetizations, which may be useful
+for understanding experimental measurements on polycrystalline samples.",1612.06608v3
+2016-12-20,Magnetocrystalline anisotropy of Laves phase Fe$_2$Ta$_{1-x}$W$_x$ from first principles - the effect of 3d-5d hybridisation,"The magnetic properties of Fe$_2$Ta and Fe$_2$W in the hexagonal Laves phase
+are computed using density functional theory in the generalised gradient
+approximation, with the full potential linearised augmented plane wave method.
+The alloy Fe$_2$Ta$_{1-x}$W$_x$ is studied using the virtual crystal
+approximation to treat disorder. Fe$_2$Ta is found to be ferromagnetic with a
+saturation magnetization of $\mu_0 M_\text{s} = 0.66~\mathrm{T}$ while, in
+contrast to earlier computational work, Fe$_2$W is found to be ferrimagnetic
+with $\mu_0 M_\text{s} = 0.35~\mathrm{T}$. The transition from the ferri- to
+the ferromagnetic state occurs for $x \leq 0.1$. The magnetocrystalline
+anisotropy energy (MAE) is calculated to $1.25~\mathrm{MJ/m^3}$ for Fe$_2$Ta
+and $0.87~\mathrm{MJ/m^3}$ for Fe$_2$W. The MAE is found to be smaller for all
+values $x$ in Fe$_2$Ta$_{1-x}$W$_x$ than for the end compounds and it is
+negative (in-plane anisotropy) for $0.1 \leq x \leq 0.9$. The MAE is carefully
+analysed in terms of the electronic structure. Even though there are weak 5d
+contributions to the density of states at the Fermi energy in both end
+compounds, a reciprocal space analysis, using the magnetic force theorem,
+reveals that the MAE originates mainly from regions of the Brillouin zone with
+strong 3d-5d hybridisation near the Fermi energy. Perturbation theory and its
+applicability in relation to the MAE is discussed.",1612.06802v1
+2016-12-30,"Topological phase in $1D$ topological Kondo insulator: $Z_{2}$ topological insulator, Haldane-like phase and Kondo breakdown","We have simulated a half-filled $1D$ $p$-wave periodic Anderson model with
+numerically exact projector quantum Monte Carlo technique, and the system is
+indeed located in the Haldane-like state as detected in previous works on the
+$p$-wave Kondo lattice model, though the soluble non-interacting limit
+corresponds to the conventional $Z_{2}$ topological insulator. The
+site-resolved magnetization in an open boundary system and strange correlator
+for the periodic boundary have been used to identify the mentioned topological
+states. Interestingly, the edge magnetization in the Haldane-like state is not
+saturated to unit magnetic moment due to the intrinsic charge fluctuation in
+our periodic Anderson-like model, which is beyond the description of the Kondo
+lattice-like model in existing literature. The finding here underlies the
+correlation driven topological state in this prototypical interacting
+topological state of matter and naive use of non-interacting picture should be
+taken care. Moreover, no trace of the surface Kondo breakdown at zero
+temperature is observed and it is suspected that frustration-like interaction
+may be crucial in inducing such radical destruction of Kondo screening. The
+findings here may be relevant to our understanding of interacting topological
+materials like topological Kondo insulator candidate SmB$_{6}$.",1612.09376v3
+2017-02-12,Some consequences of shear on galactic dynamos with helicity fluxes,"Galactic dynamo models sustained by supernova (SN) driven turbulence and
+differential rotation have revealed that the sustenance of large scale fields
+requires a flux of small scale magnetic helicity to be viable. Here we
+generalize a minimalist analytic version of such galactic dynamos to explore
+some heretofore unincluded contributions from shear on the total turbulent
+energy and turbulent correlation time, with the helicity fluxes maintained by
+either winds, diffusion, or magnetic buoyancy. We construct an analytic
+framework for modeling the turbulent energy and correlation time as functions
+of SN rate and shear. We compare our prescription with previous approaches that
+only include rotation. The solutions depend separately on the rotation period
+and the eddy turnover time and not just on their ratio (the Rossby number). We
+consider models in which these two time scales are allowed to be independent
+and also a case in which they are mutually dependent on radius when a radial
+dependent SN rate model is invoked. For the case of a fixed rotation period (or
+fixed radius) we show that the influence of shear is dramatic for low Rossby
+numbers, reducing the correlation time of the turbulence, which in turn,
+strongly reduces the saturation value of the dynamo compared to the case when
+the shear is ignored. We also show that even in the absence of winds or
+diffusive fluxes, magnetic buoyancy may be able to sustain sufficient helicity
+fluxes to avoid quenching.",1702.03560v2
+2017-03-02,Diversity of quantum ground states and quantum phase transitions of a spin-1/2 Heisenberg octahedral chain,"The spin-1/2 Heisenberg octahedral chain with regularly alternating monomeric
+and square-plaquette sites is investigated using various analytical and
+numerical methods: variational technique, localized-magnon approach, exact
+diagonalization (ED) and density-matrix renormalization group (DMRG) method.
+The model belongs to the class of flat-band systems and it has a rich
+ground-state phase diagram including phases with spontaneously broken
+translational symmetry. Moreover, it exhibits an anomalous low-temperature
+thermodynamics close to continuous or discontinuous field-driven quantum phase
+transitions between three quantum ferrimagnetic phases, tetramer-hexamer phase,
+monomer-tetramer phase, localized-magnon phase and two different spin-liquid
+phases. If the intra-plaquette coupling is at least twice as strong as the
+monomer-plaquette coupling, the variational method furnishes a rigorous proof
+of the monomer-tetramer ground state in a low-field region and the
+localized-magnon approach provides an exact evidence of a single magnon trapped
+at each square plaquette in a high-field region. In the rest of parameter space
+we have numerically studied the ground-state phase diagram and magnetization
+process using DMRG and ED methods. It is shown that the zero-temperature
+magnetization curve may involve up to four intermediate plateaus at zero,
+one-fifth, two-fifth and three-fifth of the saturation magnetization, while the
+specific heat exhibits a striking low-temperature peak in a vicinity of
+discontinuous quantum phase transitions.",1703.00715v2
+2017-03-31,Gigantic negative magnetoresistance in a disordered topological insulator,"With the recent discovery of Weyl semimetals, the phenomenon of negative
+magnetoresistance (MR) is attracting renewed interest. While small negative MR
+can occur due to the suppression of spin scattering or weak localization, large
+negative MR is rare in materials, and when it happens, it is usually related to
+magnetism. The large negative MR in Weyl semimetals is peculiar in that it is
+unrelated to magnetism and comes from chiral anomaly. Here we report that there
+is a new mechanism for large negative MR which is not related to magnetism but
+is related to disorder. In the newly-synthesized bulk-insulating topological
+insulator TlBi$_{0.15}$Sb$_{0.85}$Te$_2$, we observed gigantic negative MR
+reaching 98% in 14 T at 10 K, which is unprecedented in a nonmagnetic system.
+Supported by numerical simulations, we argue that this phenomenon is likely due
+to the Zeeman effect on a barely percolating current path formed in the
+disordered bulk. Since disorder can also lead to non-saturating linear MR in
+Ag$_{2+\delta}$Se, the present finding suggests that disorder engineering in
+narrow-gap systems is useful for realizing gigantic MR in both positive and
+negative directions.",1703.10784v2
+2017-04-10,Large magnetoresistance and Fermi surface study of Sb$_2$Se$_2$Te single crystal,"We have studied the magnetotransport properties of a Sb$_2$Se$_2$Te single
+crystal. Magnetoresistance (MR) is maximum when the magnetic field is
+perpendicular to the sample surface and reaches to a value of 1100\% at $B$=31
+T with no sign of saturation. MR shows Shubnikov de Haas (SdH) oscillations
+above $B$=15 T. The frequency spectrum of SdH oscillations consists of three
+distinct peaks at $\alpha$=32 T, $\beta$=80 T and $\gamma$=117 T indicating the
+presence of three Fermi surface pockets. Among these frequencies, $\beta$ is
+the prominent peak in the frequency spectrum of SdH oscillations measured at
+different tilt angles of the sample with respect to the magnetic field. From
+the angle dependence $\beta$ and Berry phase calculations, we have confirmed
+the trivial topology of the $\beta$-pocket. The cyclotron masses of charge
+carriers, obtained by using the Lifshitz-Kosevich formula, are found to be
+$m^{*}_{\beta}=0.16m_o$ and $m^{*}_{\gamma}=0.63m_o$ for the $\beta$ and
+$\gamma$ bands respectively. Large MR of Sb$_2$Se$_2$Te is suitable for
+utilization in electronic instruments such as a computer hard disc, high field
+magnetic sensors, and memory devices.",1704.02682v3
+2017-04-23,Anomalous Transport Properties of Dense QCD in a Magnetic Field,"Despite recent advancements in the study and understanding of the phase
+diagram of strongly interacting matter, the region of high baryonic densities
+and low temperatures has remained difficult to reach in the lab. Things are
+expected to change with the planned HIC experiments at FAIR in Germany and NICA
+in Russia, which will open a window to the high-density-low-temperature segment
+of the QCD phase map, providing a unique opportunity to test the validity of
+model calculations that have predicted the formation of spatially inhomogeneous
+phases with broken chiral symmetry at intermediate-to-high densities. Such a
+density region is also especially relevant for the physics of neutron stars, as
+they have cores that can have several times the nuclear saturation density. On
+the other hand, strong magnetic fields, whose presence is fairly common in HIC
+and in neutron stars, can affect the properties of these exotic phases and lead
+to signatures potentially observable in these two settings. In this paper, I
+examine the anomalous transport properties produced by the spectral asymmetry
+of the lowest Landau level (LLL) in a QCD-inspired NJL model with a background
+magnetic field that exhibits chiral symmetry breaking at high density via the
+formation of a Dual Chiral Density Wave (DCDW) condensate. It turns out that in
+this model the electromagnetic interactions are described by the axion
+electrodynamics equations and there is a dissipationless Hall current.",1704.06991v1
+2017-05-18,Stratified Simulations of Collisionless Accretion Disks,"This paper presents a series of stratified shearing-box simulations of
+collisionless accretion disks in the recently developed framework of kinetic
+magnetohydrodynamics (MHD), which can handle finite non-gyrotropy of a pressure
+tensor. Although a fully kinetic simulation predicted a more efficient
+angular-momentum transport in collisionless disks than in the standard MHD
+regime, the enhanced transport has not been observed in past kinetic MHD
+approaches to gyrotropic pressure anisotropy. For the purpose of investigating
+this missing link between the fully kinetic and MHD treatments, this paper pays
+attention to the role of non-gyrotropic pressure, and makes a first attempt to
+incorporate certain collisionless effects into disk-scale, stratified disk
+simulations. When the timescale of gyrotropization was longer than, or
+comparable to, the disk rotation frequency of the orbit, we found that the
+finite non-gyrotropy selectively remaining in the vicinity of current sheets
+contributes to suppressing magnetic reconnection in the shearing-box system.
+This leads to increases both in the saturated amplitude of the MHD turbulence
+driven by magnetorotational instabilities and in the resultant efficiency of
+angular-momentum transport. Our results seem favorable for fast advection of
+magnetic fields toward the rotation axis of a central object, which is required
+to launch an ultra-relativistic jet from a black-hole accretion system in, for
+example, a magnetically arrested disk state.",1705.06507v1
+2017-05-23,Half-magnetization plateau in a Heisenberg antiferromagnet on a triangular lattice,"We present the phase diagram in a magnetic field of a 2D isotropic Heisenberg
+antiferromagnet on a triangular lattice. We consider spin-$S$ model with
+nearest-neighbor ($J_1$) and next-nearest-neighbor ($J_2$) interactions. We
+focus on the range of $1/8<J_2/J_1<1$, where the ordered states are different
+from those in the model with only nearest neighbor exchange. A classical ground
+state in this range has four sublattices and is infinitely degenerate in any
+field. The actual order is then determined by quantum fluctuations via ""order
+from disorder"" phenomenon. We argue that the phase diagram is rich due to
+competition between competing four-sublattice quantum states which break either
+$\mathbb{Z}_3$ orientational symmetry or $\mathbb{Z}_4$ sublattice symmetry. At
+small and high fields, the ground state is a $\mathbb{Z}_3$-breaking canted
+stripe state, but at intermediate fields the ordered states break
+$\mathbb{Z}_4$ sublattice symmetry. The most noticeable of such states is
+""three up, one down"" state in which spins in three sublattices are directed
+along the field and in one sublattice opposite to the field. Such a state
+breaks no continuous symmetry and has gapped excitations. As the consequence,
+magnetization has a plateau at exactly one half of the saturation value. We
+identify gapless states, which border the ""three up, one down"" state and
+discuss the transitions between these states and the canted stripe state.",1705.08515v1
+2017-06-13,Structural ordering of laser-processed FePdCu thin alloy films,"The Cu/Fe/Pd multilayers were transformed into L10-ordered FePdCu alloy by
+pulsed laser annealing. The initial multilayers were irradiated with 1, 10,
+100, and 1000 laser pulses with duration time of 10 ns and energy density of
+235 mJ/cm2. The gradual change of the number of laser pulses allowed to
+investigate the structural and magnetic properties at early stages of the
+transformation and L10-ordering processes. The measurements were carried out
+using X-Ray Diffraction, SQUID magnetometry, and Magnetic Force Microscopy. We
+found that L10 FePdCu (111)-oriented nanograins are formed by ordering of the
+coherent domains present in the as-deposited multilayer. The irradiation does
+not change the vertical size of the (111) crystallites. The L10 (002)-oriented
+grains appear at the later stages of the transformation and their size
+increases with the number of applied laser pulses. Additionally, the laser
+annealing induces the magnetic ordering of the irradiated material, which was
+observed as an increase of the saturation magnetisation and the Curie
+temperature with the rising number of pulses. We also observed, that
+irradiation with 1000 pulses leads to the loss of order, which is reflected in
+the drop of the Curie temperature.",1706.03918v1
+2017-06-24,Weak antilocalization effect due to topological surface states in Bi$_2$Se$_{2.1}$Te$_{0.9}$,"We have investigated the weak antilocalization (WAL) effect in the p-type
+Bi$_2$Se$_{2.1}$Te$_{0.9}$ topological system. The magnetoconductance shows a
+cusp-like feature at low magnetic fields, indicating the presence of the WAL
+effect. The WAL curves measured at different tilt angles merge together when
+they are plotted as a function of the normal field components, showing that
+surface states dominate the magnetoconductance in the
+Bi$_2$Se$_{2.1}$Te$_{0.9}$ crystal. We have calculated magnetoconductance per
+conduction channel and applied the Hikami-Larkin-Nagaoka formula to determine
+the physical parameters that characterize the WAL effect. The number of
+conduction channels and the phase coherence length do not change with
+temperature up to T=5 K. In addition, the sample shows a large positive
+magnetoresistance that reaches 1900% under a magnetic field of 35 T at T=0.33K
+with no sign of saturation. The magnetoresistance value decreases with both
+increasing temperature and tilt angle of the sample surface with respect to the
+magnetic field. The large magnetoresistance of topological insulators can be
+utilized in future technology such as sensors and memory devices.",1706.08006v2
+2017-07-11,Interface Dzyaloshinskii-Moriya interaction in the interlayer exchange antiferromagnetic coupled Pt/CoFeB/Ru/CoFeB systems,"Interfacial Dzyaloshinskii-Moriya interaction (iDMI) in interlayer exchange
+coupled (IEC) Pt/Co$_{20}$Fe$_{60}$B$_{20}$(1.12
+nm)/Ru/Co$_{20}$Fe$_{60}$B$_{20}$(1.12 nm) systems have been studied
+theoretically and experimentally. Vibrating sample magnetometer has been used
+to measure their magnetization at saturation and their interlayer exchange
+coupling constants. These latter are found to be of an antiferromagnetic nature
+for the investigated Ru range thickness (0.5-1 nm). Their dynamic magnetic
+properties were studied using Brillouin light scattering (BLS) technique. The
+BLS measurements reveal pronounced non-reciprocal spin waves propagation. In
+contrast to the calculations for symmetrical IEC CoFeB layers, this
+experimental nonreciprocity is Ru thickness and thus coupling strength
+dependent. Therefore, to explain the experimental behaviour, a theoretical
+model based on the perpendicular interface anisotropy difference between the
+bottom and top CoFeB layers has been developed. We show that the Ru thickness
+dependence of the spin wave non-reciprocity is well reproduced by considering a
+constant iDMI and different perpendicular interfacial anisotropy fields between
+the top and bottom CoFeB layers. This anisotropy difference has been confirmed
+by the investigation of the CoFeB thickness dependence of effective
+magnetization of Pt/CoFeB/Ru and Ru/CoFeB/MgO individual layers, where a linear
+behaviour has been observed.",1707.03427v1
+2017-09-18,Magnetic and magnetotransport properties of Bi$_2$Se$_3$ thin films doped by Eu,"Structural, magnetic and magnetotransport properties of
+(Bi$_{1-x}$Eu$_x$)$_2$Se$_3$ thin films have been studied experimentally as a
+function of Eu content. The films were synthesized by MBE. It is demonstrated
+that Eu distribution is not uniform, it enter quint-layers forming inside them
+plain (pancake-like) areas containing Eu atoms, which sizes and concentration
+increase with the growth of Eu content. Positive magnetoresistance related to
+the weak antilocalization was observed up to 15K. The antilocalization was not
+followed by weak localization as theory predicts for nontrivial topological
+states. Surprisingly, the features of antilocalization were seen even at Eu
+content $x$ $=$ 0.21. With the increase of Eu content the transition to
+ferromagnetic state occurs at $x$ about 0.1 and with the Curie temperature
+$\approx$ 8K, that rises up to 64K for $x$ $=$ 0.21. At temperatures above 1-2
+K, the dephasing length is proportional to $T^{-1/2}$ indicating the dominant
+contribution of inelastic $e-e$ scattering into electron phase breaking.
+However, at low temperatures the dephasing length saturates, that could be due
+to the scattering on magnetic ions.",1709.06200v1
+2017-10-01,Theory of ground states for classical Heisenberg spin systems IV,"We extend the theory of ground states of classical Heisenberg spin systems
+previously published to the case where the interaction with an external
+magnetic field is described by a Zeeman term. The ground state problem for the
+Heisenberg-Zeeman Hamiltonian can be reduced first to the relative ground state
+problem, and, in a second step, to the absolute ground state problem for pure
+Heisenberg Hamiltonians depending on an additional Lagrange parameter. We
+distinguish between continuous and discontinuous reduction. Moreover, there are
+various general statements about Heisenberg-Zeeman systems that will be proven
+under most general assumptions. One topic is the connection between the minimal
+energy functions $E_{min}$ for the Heisenberg energy and $H_{min}$ for the
+Heisenberg-Zeeman energy which turn out to be essentially mutual
+Legendre-Fenchel transforms. This generalization of the traditional Legendre
+transform is especially suited to cope with situations where the function
+$E_{min}$ is not convex and consequently there is a magnetization jump at a
+critical field. Another topic is magnetization and the occurrence of threshold
+fields $B_{thr}$ and saturation fields $B_{sat}$, where we provide a general
+formula for the latter. We suggest a distinction between ferromagnetic and
+anti-ferromagnetic systems based on the vanishing of $B_{sat}$ for the former
+ones. Parabolic systems are defined in such a way that $E_{min}$ and $H_{min}$
+have a particularly simple form and studied in detail. For a large class of
+parabolic systems the relative ground states can be constructed from the
+absolute ground state by means of a so-called umbrella family. Finally we
+provide a counter-example of a parabolic system where this construction is not
+possible.",1710.00318v1
+2018-04-03,"Electron mirror branch: Observational evidence from ""historical"" AMPTE-IRM and Equator-S measurements","Based on now historical magnetic and plasma data and available wave spectra
+from the AMPTE-IRM spacecraft, and on as well historical Equator-S high-cadence
+magnetic field observations of mirror modes in the magnetosheath near the
+dayside magnetopause, we present some observational evidence for a recent
+theoretical evaluation by Noreen et al. (2017) of the contribution of a global
+electron temperature anisotropy to the evolution of mirror modes in the
+high-temperature anisotropic collisionless plasma of the magnetosheath causing
+a separate electron mirror branch. These old data most probably indicate that
+signatures of this electron effect on mirror modes had indeed been observed
+already long ago in magnetic and wave data though had not been recognised as
+such. Unfortunately either poor time resolution or complete lack of plasma data
+would have inhibited the confirmation of the notoriously required pressure
+balance in the electron branch for unambiguous confirmation of a separate
+electron mirror mode. If confirmed by future high-resolution observations, in
+both cases the large mirror mode amplitudes suggest that mirror modes escape
+quasilinear saturation being in a state of weak kinetic plasma turbulence.",1804.01131v2
+2018-04-06,"Low mass planet migration in magnetically torqued dead zones - II. Flow-locked and runaway migration, and a torque prescription","We examine the migration of low mass planets in laminar protoplanetary discs,
+threaded by large scale magnetic fields in the dead zone that drive radial gas
+flows. As shown in Paper I, a dynamical corotation torque arises due to the
+flow-induced asymmetric distortion of the corotation region and the evolving
+vortensity contrast between the librating horseshoe material and background
+disc flow. Using simulations of laminar torqued discs containing migrating
+planets, we demonstrate the existence of the four distinct migration regimes
+predicted in Paper I. In two regimes, the migration is approximately locked to
+the inward or outward radial gas flow, and in the other regimes the planet
+undergoes outward runaway migration that eventually settles to fast steady
+migration. In addition, we demonstrate torque and migration reversals induced
+by midplane magnetic stresses, with a bifurcation dependent on the disc surface
+density. We develop a model for fast migration, and show why the outward
+runaway saturates to a steady speed, and examine phenomenologically its
+termination due to changing local disc conditions. We also develop an
+analytical model for the corotation torque at late times that includes
+viscosity, for application to discs that sustain modest turbulence. Finally, we
+use the simulation results to develop torque prescriptions for inclusion in
+population synthesis models of planet formation.",1804.02290v1
+2018-04-15,$\mathrm{Co_2Fe_{1-x}Cr_xSi}$ Heusler Alloys : A promising material for spintronics application,"In this article, we investigated the effect of Cr substitution in place of Fe
+on the structural, magnetic and transport properties of $\mathrm{Co_2FeSi}$
+alloy. A comprehensive structural analysis is done using X-ray diffraction
+(XRD) and extended X-ray absorption fine structure (EXAFS) spectroscopy.
+Quaternary Heusler compounds $\mathrm{Co_2Fe_{1-x}Cr_xSi}$ with Cr content (x =
+0.1, 0.3, 0.5) were found to crystallize in cubic structure. The synchrotron
+based EXAFS studies reveal that the anti-site disorder increases with the
+increase in Cr concentration. The saturation magnetization values in all the
+alloys are found to be less than those expected from the Slater-Pauling rule,
+which may be due to the some inherent disorder. A detailed resistivity analysis
+in the temperature range of 5-300 K is done, taking into account different
+scattering mechanisms. The residual resistivity ratio is found to decrease with
+increasing Cr concentration. A disorder induced resistivity minimum due to weak
+localization effect is seen for x = 0.5. The resistivity measurements also
+indicate that the half-metallic character survives upto 100 K for x = 0.1,
+whereas the alloys with x= 0.3 and 0.5 show signature of half- metallic nature
+even at higher temperatures. First principles calculation done with a more
+robust exchange correlation functional (namely HSE-06) confirms the half
+metallicity in the entire concentration range. Theoretically simulated band gap
+and magnetic moments compliment the experimental findings and are compared
+wherever possible. All these properties make $\mathrm{Co_2Fe_{1-x}Cr_xSi}$ a
+promising material for spintronics application.",1804.05321v1
+2018-06-07,High Performance Metallic Amorphous Magnetic Flake-based Magnetodielectric Inductors,"Flake-shaped FeSi-based metallic amorphous alloy particles, having an aspect
+ratio as high as 175 to 1, were prepared by ball milling gas atomized amorphous
+powders of an effective diameter of 20 micrometers. The starting powder had a
+saturation magnetic flux density, Bs, of 1.5 T and a coercivity, Hc, of 94 A/m.
+The aspect ratio of the flakes, as well as their magnetic properties, were
+controlled by milling process parameters, such as duration, speed, and the
+type, mass and diameter of the milling balls. To minimize the oxidation of the
+charge, the powders were handled in an argon gas-purged glove box, milled in
+toluene, and subsequently dried in vacuo. Subsequently, soft magnetodielectric
+composites were prepared by suspending and aligning the FeSi-based powders in
+paraffin wax or epoxy resin. The composites were then pressed into toroids for
+measurements of their high frequency complex permeability by a vector network
+analyzer. The influence of the flake aspect ratio and volume loading fraction
+on the permeability of the composites were investigated. Results indicate that
+the composite permeability increases with the flake aspect ratio. For example,
+for a given loading factor of 30 vol.%, the composite permeability at 0.1 GHz
+nearly tripled and approached the value of 10 by increasing the aspect ratio of
+the FeSi-based inclusions from 1 (spheres) to greater than 175 to 1 (flakes).",1806.02486v2
+2018-06-21,Unconventional critical state in YBa$_{2}$Cu$_{3}$O$_{7-δ}$ thin films with a vortex-pin lattice fabricated by masked He$^+$ ion beam irradiation,"Thin superconducting YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ films are patterned with
+a vortex-pin lattice consisting of columnar defect regions (CDs) with 180 nm
+diameter and 300 nm spacing. They are fabricated by irradiation with 75 keV
+He$^+$ ions through a stencil mask. Peaks of the critical current reveal the
+commensurate trapping of vortices in domains near the edges of the sample. Upon
+ramping an external magnetic field, the positions of the critical current peaks
+are shifted from their equilibrium values to lower magnetic fields in virgin
+and to higher fields in field-saturated down-sweep curves, respectively. Based
+on previous theoretical predictions, this irreversibility is interpreted as a
+nonuniform, terrace-like critical state, in which individual domains are
+occupied by a constant number of vortices per pinning site. The
+magnetoresistance, probed at low current densities, is hysteretic and angle
+dependent and exhibits minima that correspond to the peaks of the critical
+current. The minima's positions scale with the component of the magnetic field
+parallel to the axes of the CDs, as long as the tilted vortices can be
+accommodated within the CDs. This behavior, different from unirradiated films,
+confirms that the CDs dominate the pinning.",1806.08164v1
+2018-06-25,"3D global simulations of RIAFs: convergence, effects of azimuthal extent and dynamo","We study the long-term evolution of non-radiative geometrically thick
+($H/R\approx 0.5$) accretion flows using 3D global ideal MHD simulations and a
+pseudo-Newtonian gravity. We find that resolving the scale height with 42 grid
+points is adequate to obtain convergence with the product of quality factors
+$\langle \langle Q_{\theta} \rangle \rangle \langle \langle Q_{\phi} \rangle
+\rangle \geq 300$ and magnetic tilt angle $\theta_B \sim
+13^{\circ}-14^{\circ}$. Like previous global isothermal thin disk simulations,
+we find stronger mean magnetic fields for the restricted azimuthal domains.
+Imposing periodic boundary conditions with the azimuthal extent smaller than
+$2\pi$ make the turbulent field at low $m$ appear as a mean field in the runs
+with smaller azimuthal extent. But unlike previous works, we do not find a
+monotonic trend in turbulence with the azimuthal extent. We conclude that the
+minimum azimuthal extent should be $\geq \pi/2$ to capture the flow structure,
+but a full $2 \pi$ extent is necessary to study the dynamo. We find an
+intermittent dynamo cycle, with $\alpha$-quenching playing an important role in
+the nonlinear saturated state. Unlike previous local studies, we find almost
+similar values of kinetic and magnetic $\alpha$-s, giving rise to an irregular
+distribution of dynamo-$\alpha$. The effects of dynamical quenching are shown
+explicitly for the first time in global simulations of accretion flows.",1806.09629v3
+2018-08-03,Collapse of Kondo state and ferromagnetic quantum phase transition in YbFe$_2$Zn$_{20}$,"We present the electrical resistivity data under application of pressures up
+to $\sim$ 26 GPa and down to 50 mK temperatures on YbFe$_2$Zn$_{20}$. We find a
+pressure induced magnetic phase transition with an onset at $p_c$=18.2$\pm$0.8
+GPa. At ambient pressure, YbFe$_2$Zn$_{20}$ manifests a heavy fermion,
+nonmagnetic ground state and the Fermi liquid behavior at low temperatures. As
+pressure is increased, the power law exponent in resistivity, $n$, deviates
+significantly from Fermi liquid behavior and tends to saturate with $n$ = 1
+near $p_c$. A pronounced resistivity maximum, $T_\text{max}$, which scales with
+Kondo temperature is observed. $T_\text{max}$ decreases with increasing
+pressure and flattened out near $p_c$ indicating the suppression of Kondo
+exchange interaction. For $p>p_c$, $T_\text{max}$ shows a sudden upward shift,
+most likely becoming associated with crystal electric field scattering.
+Application of magnetic field for $p>p_c$ broadens the transition and shifts it
+toward the higher temperature, which is a typical behavior of the ferromagnetic
+transition. The magnetic transition appears to abruptly develop above $p_c$,
+suggesting probable first-order (with changing pressure) nature of the
+transition; once stabilized, the ordering temperature does not depend on
+pressure up to $\sim$ 26 GPa. Taken as a whole, these data suggest that
+YbFe$_2$Zn$_{20}$ has a quantum phase transition at $p_c$ = 18.2 GPa associated
+with the avoided quantum criticality in metallic ferromagnets.",1808.01367v1
+2018-11-12,Evidence for unconventional superconductivity in Half-Heusler YPdBi and TbPdBi compounds revealed by London penetration depth measurements,"The half-Heusler compounds YPdBi and TbPdBi, while having similar band
+structure, exhibit different magnetic properties. YPdBi is a diamagnet, while
+TbPdBi shows antiferromagnetic order below 5.5 K. Both are superconductors with
+T${_c}\approx$1 K for YPdBi and T${_c}\approx$1.75 K for TbPdBi. Such a
+contrast in properties between these two compounds opens a question about the
+effects of band structure or magnetic correlations on superconductivity. Using
+the combination of a tunnel diode oscillator (TDO) and a commercial dilution
+refrigerator, we measured temperature dependent magnetic penetration depth
+$\Delta\lambda(T)$ in single crystals of YPdBi and TbPdBi, down to temperatures
+as low as 0.1K. We found that penetration depths of both compounds do not show
+exponential temperature dependence and saturation at low temperatures, as
+expected for conventional BCS superconductors. Instead, in both compounds, the
+penetration depth can be described by a power law $\Delta\lambda(T) = A\times
+T^{n}$. The coefficient A was found to be about 50$\%$ smaller in TbPdBi, but
+the exponents are very similar, $n = 2.76\pm 0.04$ in YPdBi and $n = 2.6\pm
+0.3$ in TbPdBi, respectively. Our results suggest unconventional
+superconductivity in both YPdBi and TbPdBi.",1811.05045v1
+2019-03-26,Engineering of spin mixing conductance in Ru/FeCo/Ru interfaces: Effect of Re Doping,"We have deposited polycrystalline Re doped $(Fe_{65}Co_{35})_{100-x}Re_{x}$
+(0 $\leq$ x $\leq$ 12.6 at\%) thin films grown under identical conditions and
+sandwiched between thin layers of Ru in order to study the phenomenon of spin
+pumping as a function of Re concentration. In-plane and out-of-plane
+ferromagnetic resonance spectroscopy results show an enhancement of the Gilbert
+damping with an increase in Re doping. We found evidence of an increase in the
+real part of effective spin mixing conductance
+[Re($g^{\uparrow\downarrow}_{eff}$)] with the increase in Re doping of 6.6
+at\%, while a decrease is evident at higher Re doping. The increase in
+Re($g^{\uparrow\downarrow}_{eff}$) can be linked to the Re doping induced
+change of the interface electronic structure in the non-magnetic Ru layer and
+the effect interfacial spin-orbit coupling has on the effective spin-mixing
+conductance. The lowest and highest values of
+Re($g^{\uparrow\downarrow}_{eff}$) are found to be 9.883(02) $nm^{-2}$ and
+19.697(02) $nm^{-2}$ for 0 at\% and 6.6 at\% Re doping, respectively. The
+saturation magnetization decreases with increasing Re doping, from 2.362(13) T
+for the undoped film to 1.740(03) T for 12.6 at\% Re doping. This study opens a
+new direction of tuning the spin-mixing conductance in magnetic
+heterostructures by doping of the ferromagnetic layerr, which is essential for
+the realization of energy efficient operation of spintronic devices.",1903.10966v2
+2019-04-03,Study of the Effect of Annealing on the Properties of Mn2RuxGa Thin Films,"The effect of vacuum annealing thin films of the compensated ferrimagnetic
+half-metal Mn2RuxGa at temperatures from 250 to 400 degree Celsius is
+investigated. The 39.3 nm films deposited on (100) MgO substrates exhibit
+perpendicular magnetic anisotropy due to a small 1% tetragonal elongation
+induced by substrate strain. The main change on annealing is a modification in
+the compensation temperature, which first increases from 50 K for the
+as-deposited film to 185 K after annealing at 250 degree Celsius, and then
+falls to 140 K after annealing at 400 degree Celsius. There are minor changes
+in the atomic order, coercivity, resistivity and anomalous Hall effect (AHE),
+but the net magnetization measured by SQUID magnetometry with the field applied
+in-plane or perpendicular-to-the-plane changes more significantly. It saturates
+at 20 to 30 kA/m at room temperature, and a small soft component is seen in the
+perpendicular SQUID loops which is absent in the square AHE hysteresis loops.
+This is explained by the half-metallic nature of the compound; the AHE probes
+only the 4c Mn sublattice that provides the spin-polarized electrons at the
+Fermi level, whereas the SQUID measures the sum of the oppositely-aligned 4c
+and 4a sublattice magnetisations.",1904.01993v1
+2019-04-05,"Stoichiometry, Phase, and Texture Evolution in PLD-Grown Hexagonal Barium Ferrite Films as a Function of Laser Process Parameters","Barium hexaferrite (BaFe12O19 or BaM) films were grown on c-plane sapphire
+(0001) substrates by pulsed laser deposition (PLD) to evaluate the effects of
+the laser fluence on their composition, structure, and magnetic properties.
+Continuum's Surelite pulsed 266nm Nd:YAG laser was employed, and the laser
+fluence varied systemically between 1 and 5.7 [J/cm2]. Deviations from the
+stoichiometric transfer between the BaM targets and deposited thin films
+occurred as the laser fluence changed. The Fe to Ba ratio in the films
+increased with the laser fluence. The films deposited at the laser fluences
+below 4 J/cm2 showed undesirable 3-dimensional islands on the surface.
+Moreover, insufficient laser energy resulted in the deposition of some
+secondary phases, for example, barium monoferrite (BaFe2O4) and Magnetite
+(Fe3O4). On the other hand, laser fluences above 5 J/cm2 promoted resputtering
+and degraded the film quality, structure, and magnetic properties. BaM films
+deposited at 4.8 J/cm2 - the optimal laser fluence - showed excellent c-axis
+orientation perpendicular to the film plane with the anisotropy field of 16 kOe
+and saturation magnetization of 4.39 kOe. These results clearly demonstrate a
+strong influence of the laser parameters on the PLD-grown hexaferrite films and
+pave the path for the high-yield production using PLD systems.",1904.03157v2
+2019-07-10,Electronic Transport Evidence for Topological Nodal-Line Semimetals of ZrGeSe single crystals,"Although the band topology of ZrGeSe has been studied via magnetic torque
+technique, the electronic transport behaviors related to the relativistic
+Fermions in ZrGeSe are still unknown. Here, we first report systematic
+electronic transport properties of high-quality ZrGeSe single crystals under
+magnetic fields up to 14 T. Resistivity plateaus of temperature dependent
+resistivity curves both in the presence and absence of magnetic fields as well
+as large, non-saturating magnetoresistance in low-temperature region were
+observed. By analyzing the temperature- and angular-dependent Shubnikov-de Haas
+oscillations and fitting it via the Lifshitz-Kosevich (LK) formula with the
+Berry phase being taken into account, we proved that Dirac fermions dominate
+the electronic transport behaviors of ZrGeSe and the presence of non-trivial
+Berry phase. First principles calculations demonstrate that ZrGeSe possesses
+Dirac bands and normal bands near Fermi surface, resulting in the observed
+magnetotransport phenomena. These results demonstrate that ZrGeSe is a
+topological nodal-line semimetal, which provides a fundamentally important
+platform to study the quantum physics of topological semimetals.",1907.04762v1
+2019-08-05,Spin inertia and polarization recovery in quantum dots: Role of pumping strength and resonant spin amplification,"Spin inertia measurements are a novel experimental tool to study long-time
+spin relaxation processes in semiconductor nanostructures. We develop a theory
+of the spin inertia effect for resident electrons and holes localized in
+quantum dots. We consider the spin orientation by short optical pulses with
+arbitrary pulse area and detuning from the trion resonance. The interaction
+with an external longitudinal magnetic field and the hyperfine interaction with
+the nuclear spin bath is considered in both the ground and excited (trion)
+states of the quantum dots. We analyze how the spin inertia signal depends on
+the magnetic field (polarization recovery) and on the modulation frequency of
+the helicity of the pump pulses as well as on their power and detuning. In
+particular, we elaborate how approaching the saturation limit of the spin
+polarization influences the measurements. The quantitative description of spin
+inertia measurements will enable the determination of the parameters of spin
+dynamics such as the spin relaxation times in the ground and excited states and
+the parameters of the hyperfine interaction. Finally, we predict the emergence
+of resonant spin amplification due to the transverse components of the nuclear
+spin fluctuations, which manifests itself as oscillations of the spin
+polarization as a function of the longitudinal magnetic field.",1908.01531v3
+2019-09-04,Formation of Power-law Electron Energy Spectra in Three-dimensional Low-$β$ Magnetic Reconnection,"While observations have suggested that power-law electron energy spectra are
+a common outcome of strong energy release during magnetic reconnection, e.g.,
+in solar flares, kinetic simulations have not been able to provide definite
+evidence of power-laws in energy spectra of non-relativistic reconnection. By
+means of 3D large-scale fully kinetic simulations, we study the formation of
+power-law electron energy spectra in non-relativistic low-$\beta$ reconnection.
+We find that both the global spectrum integrated over the entire domain and
+local spectra within individual regions of the reconnection layer have
+power-law tails with a spectral index $p \sim 4$ in the 3D simulation, which
+persist throughout the non-linear reconnection phase until saturation. In
+contrast, the spectrum in the 2D simulation rapidly evolves and quickly becomes
+soft. We show that 3D effects such as self-generated turbulence and chaotic
+magnetic field lines enable the transport of high-energy electrons across the
+reconnection layer and allow them to access several main acceleration regions.
+This leads to a sustained and nearly constant acceleration rate for electrons
+at different energies. We construct a model that explains the observed
+power-law spectral index in terms of the dynamical balance between particle
+acceleration and escape from main acceleration regions, which are defined based
+upon a threshold for the curvature drift acceleration term. This result could
+be important for explaining the formation of power-law energy spectrum in solar
+flares.",1909.01911v1
+2019-09-21,Tailoring the optical and physical properties of La doped ZnO nanostructured thin films,"The modification and tailoring the characteristics of nanostructured
+materials are of great interest due to controllable and unusual inherent
+properties in such materials. A simple spray pyrolysis technique is used to
+prepare pure and La-doped ZnO films. The influence of La concentration (0,
+0.33, 0.45, 0.66, 0.92 and 1.04 at. %) on the structural, optical, and magnetic
+properties of ZnO was investigated. The exact nominal compositions of the
+prepared films were determined from the field emission scanning electron
+microscope occupied with EDX. X-ray diffraction confirmed that the samples
+possessed single-phase hexagonal wurtzite structure. The main crystal size was
+decreased from 315.50 {\AA} to 229.04 {\AA} depending on La dopant
+concentration. This decrease is due to the small ionic radius of Zn ions in
+compared to La ions. The band gap values were found to be depend strongly on
+La3+ ion content. Introducing La into ZnO induces a clear magnetic moment
+without any distortion in the geometrical symmetry, it also reveals the
+ferromagnetic coupling. The saturation magnetic moment of 1.04 at% La-doped ZnO
+shows the highest value of 0.014 emu, which is ~23 times higher than pure ZnO
+sample. The obtained results were discussed and compared with other literature
+data and showed an acceptable agreement.",1909.09869v1
+2019-09-23,Electron pairing in mirror modes: Surpassing the quasilinear limit,"The mirror mode evolving in collisionless magnetised high-temperature
+thermally anisotropic plasmas is shown to develop an interesting macro-state.
+Starting as a classical zero frequency ion fluid instability it saturates
+quasi-linearly at very low magnetic level, while forming elongated magnetic
+bubbles which trap the electron component to perform an adiabatic bounce motion
+along the magnetic field. {Further evolution of the mirror mode towards a
+stationary state is determined by the bouncing trapped electrons which interact
+with the thermal level of ion sound waves, generate attractive wake potentials
+which give rise to formation of electron pairs in the lowest-energy singlet
+state of two combined electrons. Pairing takes preferentially place near the
+bounce-mirror points where the pairs become spatially locked with all their
+energy in the gyration. The resulting large anisotropy of pairs enters the
+mirror growth rate in the quasi-linearly stable mirror mode. It breaks the
+quasilinear stability and causes further growth. Pressure balance is either
+restored by dissipation of the pairs and their anisotropy or inflow of plasma
+from the environment. In the first case new pairs will continuously form until
+equilibrium is reached. In the final state the fraction of pairs can be
+estimated. This process is open to experimental verification. To our knowledge
+it is the only process where in high temperature plasma pairing may occur and
+has an important observable macroscopic effect: breaking the quasilinear limit
+and generation of localised diamagnetism.}",1909.10163v1
+2019-10-11,Observation of Fano resonance in photoluminescence of a two-dimensional magnetic semiconductor,"Quantum interference gives rise to the asymmetric Fano resonance line shape
+when the final states of an electronic transition follows within a continuum of
+states and a discrete state, which has significant applications in optical
+switching and sensing. The resonant optical phenomena associated with Fano
+resonance have been observed by absorption spectra, Raman spectra, transmission
+spectra, etc., but have rarely been reported in photoluminescence (PL)
+spectroscopy. In this work, we performed spectroscopic studies on layered
+chromium thiophosphate (CrPS4), a promising ternary antiferromagnetic
+semiconductor with PL in near-infrared wavelength region and observed Fano
+resonance when CrPS4 experiences phase transition into the antiferromagnetic
+state below N\'eel temperature (38 K). The photoluminescence of the continuum
+states results from the d band transitions localized at Cr3+ ions, while the
+discrete state reaches saturation at high excitation power and can be enhanced
+by the external magnetic field, suggesting it is formed by an impurity level
+from extra atomic phosphorus. Our findings provide insights into the electronic
+transitions of CrPS4 and their connection to its intrinsic magnetic properties.",1910.05164v1
+2019-10-22,Magnetic topological insulator MnBi6Te10 with zero-field ferromagnetic state and gapped Dirac surface states,"Magnetic topological insulators (TIs) with nontrivial topological electronic
+structure and broken time-reversal symmetry exhibit various exotic topological
+quantum phenomena. The realization of such exotic phenomena at high temperature
+is one of central topics in this area. We reveal that MnBi6Te10 is a magnetic
+TI with an antiferromagnetic ground state below 10.8 K whose nontrivial
+topology is manifested by Dirac-like surface states. The ferromagnetic axion
+insulator state with Z4 = 2 emerges once spins polarized at field as low as 0.1
+T, accompanied with saturated anomalous Hall resistivity up to 10 K. Such a
+ferromagnetic state is preserved even external field down to zero at 2 K.
+Theoretical calculations indicate that the few-layer ferromagnetic MnBi6Te10 is
+also topologically nontrivial with a non-zero Chern number. Angle-resolved
+photoemission spectroscopy experiments further reveal three types of Dirac
+surface states arising from different terminations on the cleavage surfaces,
+one of which has insulating behavior with an energy gap of ~ 28 meV at the
+Dirac point. These outstanding features suggest that MnBi6Te10 is a promising
+system to realize various topological quantum effects at zero field and high
+temperature.",1910.10101v2
+2019-11-17,A Monte Carlo Study on the Variation of Residual Magnetisation with the Ratio of Coupling Strengths and Non-magnetic Impurities in an Ising Trilayer,"We have studied a spin-1/2, ABA, Ising trilayer system with two different
+types of interactions, in-plane ferromagnetic and out-of-plane
+anti-ferromagnetic, among the lattice sites, on different layers. In the pure
+case, devoid of any impurity, we employed Monte-Carlo method with single
+spin-flip Metropolis algorithm to find out the anti-ferromagnetic critical
+temperature (N\'eel temperature) and another lower temperature, called the
+compensation temperature, both with total magnetisation zero, in accordance
+with already established results for square lattice. Then non-magnetic
+impurities, (spin value= 0) were implanted on each layer at randomly picked
+sites and their concentration was increased in steps from 5% to 20%. The ratio
+of inter-planar anti-ferromagnetic to mid-layer ferromagnetic coupling strength
+as well as the ratio of top and bottom layer ferromagnetic to mid layer
+ferromagnetic coupling strength were also varied and N\'eel and compensation
+temperatures, both were observed shifting towards lower temperature values with
+increase in concentration of impurities in the lattice for any fixed ratio of
+different coupling strengths, in absence of any external magnetic field. In
+addition, the magnitude of the residual magnetisation i.e. the ratio of the
+peak value of the magnetisation in between N\'eel and compensation points and
+the saturated value of magnetisation, was also observed to vary with different
+values of controlling parameters.",1911.07261v2
+2019-11-19,Superconductivity below 2.5K in Nb0.25Bi2Se3 topological insulator single crystal,"We report crystal growth and below 2.5K superconductivity of Nb0.25Bi2Se3.
+These crystals are grown by self flux method. The X-ray diffraction (XRD)
+pattern of as grown crystal flake shows (00l) plane (c-orientation) growth. The
+Rietveld refinement of crushed crystal powder XRD (PXRD) pattern confirms the
+phase purity of the studied sample having R-3m space group of rhombohedral
+crystalline structure. The Raman spectrum of the studied Nb0.25Bi2Se3 crystal
+distinctly shows three well defined vibrational modes in terms of A11g, Eg2,
+A21g at around 72, 129 and 173cm-1, which are slightly shifted in comparison to
+pure Bi2Se3. Magnetization studies in terms of field cooled (FC) and Zero field
+cooled (ZFC) magnetic susceptibility measurements show the diamagnetic
+transition (Tconset) of the compound at around 2.5K and near saturation of the
+same below around 2.1K. The isothernal magnetization (MH) being taken at 2K,
+revealed the lower critical field (Hc1) of around 50Oe and the upper critical
+field (Hc2) of 900Oe. It is clear the studied Nb0.25Bi2Se3 is a bulk
+superconductor. The superconducting critical parameters thus calculated viz.
+the coherence length, upper and lower critical fields and superconducting
+transition temperature for as grown Nb0.25Bi2Se3 single crystal are reported
+here.",1911.08108v1
+2020-03-24,Anisotropic Physical Properties of the Kondo Semimetal CeCu$_{1.11}$As$_2$,"The recently proposed novel materials class called Weyl-Kondo semimetal
+(WKSM) is a time reversal invariant but inversion symmetry broken Kondo
+semimetal in which Weyl nodes are pushed to the Fermi level by the Kondo
+interaction. Here we explore whether CeCu$_{1+x}$As$_2$ may be a new WKSM
+candidate. We report on its single-crystal growth, structure determination and
+physical properties investigation. Previously published studies on
+polycrystalline samples suggest that it is indeed a Kondo semimetal, which is
+confirmed by our investigations on single crystals. X-ray diffraction reveals
+that CeCu$_{1+x}$As$_2$ crystallizes in a tetragonal centrosymmetric structure,
+although the inversion symmetry could still be broken locally due to partially
+occupied Cu sites. Chemical analysis results in an average occupation $x$ =
+0.11(1). The electrical resistivity increases logarithmically with decreasing
+temperature, and saturates below 10 K. A Kondo temperature $T_{\mathrm{K}}$
+$\approx$ 4 K is extracted from entropy, estimated from the specific heat
+measurements. From Hall effect experiments, a charge carrier density of $8.8
+\times 10^{20}$ cm$^{-3}$ is extracted, a value characteristic of a semimetal.
+The magnetization shows pronounced anisotropy, with no evidence of magnetic
+ordering down to 0.4 K. We thus classify CeCu$_{1.11}$As$_2$ as a tetragonal
+Kondo semimetal with anisotropic magnetic properties, with a possibly broken
+inversion symmetry, thus fulfilling the necessary conditions for a WKSM state.",2003.10794v1
+2020-03-30,Electric heating and angular momentum transport in laminar models of protoplanetary disks,"The vertical temperature structure of a protoplanetary disk bears on several
+processes relevant to planet formation, such as gas and dust grain chemistry,
+ice lines and convection. The temperature profile is controlled by irradiation
+from the central star and by any internal source of heat such as might arise
+from gas accretion. We investigate the heat and angular momentum transport
+generated by the resistive dissipation of magnetic fields in laminar disks. We
+use local one-dimensional simulations to obtain vertical temperature profiles
+for typical conditions in the inner disk (0.5 to 4 au). Using simple
+assumptions for the gas ionization and opacity, the heating and cooling rates
+are computed self-consistently in the framework of radiative non-ideal
+magnetohydrodynamics. We characterize steady solutions that are symmetric about
+the midplane and which may be associated with saturated Hall-shear unstable
+modes. We also examine the dissipation of electric currents driven by global
+accretion-ejection structures. In both cases we obtain significant heating for
+a sufficiently high opacity. Strong magnetic fields can induce an order-unity
+temperature increase in the disk midplane, a convectively unstable entropy
+profile, and a surface emissivity equivalent to a viscous heating of $\alpha
+\sim 10^{-2}$. These results show how magnetic fields may drive efficient
+accretion and heating in weakly ionized disks where turbulence might be
+inefficient, at least for a range of radii and ages of the disk.",2003.13263v2
+2020-07-09,Results of search for magnetized quark-nugget dark matter from radial impacts on Earth,"Magnetized Quark Nuggets (MQNs) are a recently proposed dark-matter candidate
+consistent with the Standard Model and with Tatsumi's theory of quark-nugget
+cores in magnetars. Previous publications have covered their formation in the
+early universe, aggregation into a broad mass distribution before they can
+decay by the weak force, interaction with normal matter through their
+magnetopause, and first observation consistent MQNs, i.e. a nearly tangential
+impact limiting their surface-magnetic-field parameter B_o from Tatsumi's
+values of 0.1 to 10.0 TT to new value of 1.65 TT +/- 21%. The MQN mass
+distribution and interaction cross section depend strongly on B_o. Their
+magnetopause is much larger than their geometric dimensions and can cause
+sufficient energy deposition to form non-meteorite craters, which are reported
+approximately annually. We report computer simulations of the MQN energy
+deposition in water-saturated peat, soft sediments, and granite and report
+results from excavating such a crater. Five points of agreement between
+observations and hydrodynamic simulations of an MQN impact support this second
+observation consistent with MQN dark matter and suggest a method for qualifying
+additional MQN events. The results also redundantly constrain B_o to greater
+than 0.4 TT.",2007.04826v3
+2020-07-14,Microtearing modes as the source of magnetic fluctuations in the JET pedestal,"We report on a detailed study of magnetic fluctuations in the JET pedestal,
+employing basic theoretical considerations, gyrokinetic simulations, and
+experimental fluctuation data, to establish the physical basis for their
+origin, role, and distinctive characteristics. We demonstrate quantitative
+agreement between gyrokinetic simulations of microtearing modes (MTMs) and two
+magnetic frequency bands with corresponding toroidal mode numbers n=4 and 8.
+Such disparate fluctuation scales, with substantial gaps between toroidal mode
+numbers, are commonly observed in pedestal fluctuations. Here we provide a
+clear explanation, namely the alignment of the relevant rational surfaces (and
+not others) with the peak in the omega star profile, which is localized in the
+steep gradient region of the pedestal. We demonstrate that a global treatment
+is required to capture this effect. Nonlinear simulations suggest that the MTM
+fluctuations produce experimentally-relevant transport levels and saturate by
+relaxing the background electron temperature gradient, slightly downshifting
+the fluctuation frequencies from the linear predictions. Scans in
+collisionality are compared with simple MTM dispersion relations. At the
+experimental points considered, MTM growth rates can either increase or
+decrease with collision frequency depending on the parameters thus defying any
+simple characterization of collisionality dependence.",2007.07332v1
+2020-08-04,Ultrathin perpendicular free layers for lowering the switching current in STT-MRAM,"The critical current density $J_{c0}$ required for switching the
+magnetization of the free layer (FL) in a spin-transfer torque magnetic random
+access memory (STT-MRAM) cell is proportional to the product of the damping
+parameter, saturation magnetization and thickness of the free layer, $\alpha
+M_S t_F$. Conventional FLs have the structure CoFeB/nonmagnetic spacer/CoFeB.
+By reducing the spacer thickness, W in our case, and also splitting the single
+W layer into two layers of sub-monolayer thickness, we have reduced $t_F$ while
+minimizing $\alpha$ and maximizing $M_S$, ultimately leading to lower $J_{c0}$
+while maintaining high thermal stability. Bottom-pinned MRAM cells with device
+diameter in the range of 55-130 nm were fabricated, and $J_{c0}$ is lowest for
+the thinnest (1.2 nm) FLs, down to 4 MA/cm$^2$ for 65 nm devices, $\sim$30%
+lower than 1.7 nm FLs. The thermal stability factor $\Delta_{\mathrm{dw}}$, as
+high as 150 for the smallest device size, was determined using a domain wall
+reversal model from field switching probability measurements. With high
+$\Delta_{\mathrm{dw}}$ and lowest $J_{c0}$, the thinnest FLs have the highest
+spin-transfer torque efficiency.",2008.01343v1
+2020-09-13,Topologically-Driven Linear Magnetoresistance in Helimagnetic FeP,"The helimagnet FeP is part of a family of binary pnictide materials with the
+MnP-type structure which share a nonsymmorphic crystal symmetry that preserves
+generic band structure characteristics through changes in elemental
+composition. It shows many similarities, including in its magnetic order, to
+isostructural CrAs and MnP, two compounds that are driven to superconductivity
+under applied pressure. Here we present a series of high magnetic field
+experiments on high quality single crystals of FeP, showing that the resistance
+not only increases without saturation by up to several hundred times its zero
+field value by 35 T, but that it also exhibits an anomalously linear field
+dependence over the entire field range when the field is aligned precisely
+along the crystallographic c-axis. A close comparison of quantum oscillation
+frequencies to electronic structure calculations links this orientation to a
+semi-Dirac point in the band structure which disperses linearly in a single
+direction in the plane perpendicular to field, a symmetry-protected feature of
+this entire material family. We show that the two striking features of MR-large
+amplitude and linear field dependence-arise separately in this system, with the
+latter likely due to a combination of ordered magnetism and topological band
+structure.",2009.05984v2
+2020-10-10,Collisionless Rayleigh-Taylor-like instability of the boundary between a hot pair plasma and an electron-proton plasma: the undular mode,"We study with a two-dimensional particle-in-cell simulation the stability of
+a discontinuity or piston, which separates an electron-positron cloud from a
+cooler electron-proton plasma. Such a piston might be present in the
+relativistic jets of accreting black holes separating the jet material from the
+surrounding ambient plasma and when pair clouds form during an X-ray flare and
+expand into the plasma of the accretion disk corona. We inject a pair plasma at
+a simulation boundary with a mildly relativistic temperature and mean speed. It
+flows across a spatially uniform electron-proton plasma, which is permeated by
+a background magnetic field. The magnetic field is aligned with one simulation
+direction and oriented orthogonally to the mean velocity vector of the pair
+cloud. The expanding pair cloud expels the magnetic field and piles it up at
+its front. It is amplified to a value large enough to trap ambient electrons.
+The current of the trapped electrons, which are carried with the expanding
+cloud front, drives an electric field that accelerates protons. A solitary wave
+grows and changes into a piston after it saturated. Our simulations show that
+this piston undergoes a collision-less instability similar to a Rayleigh-Taylor
+instability. The undular mode grows and we observe fingers in the proton
+density distribution. The effect of the instability is to deform the piston but
+it cannot destroy it.",2010.04981v1
+2020-10-17,Multiscale modelling of magnetostatic effects on magnetic nanoparticles with application to hyperthermia,"We extend a renormalization group-based course-graining method for
+micromagnetic simulations to include properly scaled magnetostatic
+interactions. We apply the method in simulations of dynamic hysteresis loops at
+clinically relevant sweep rates and at 310 K of iron oxide nanoparticles (NPs)
+of the kind that have been used in preclinical studies of magnetic
+hyperthermia. The coarse-graining method, along with a time scaling involving
+sweep rate and Gilbert damping parameter, allow us to span length scales from
+the unit cell to NPs approximately 50 nm in diameter with reasonable simulation
+times. For both NPs and the nanorods composing them, we report effective
+uniaxial anisotropy strengths and saturation magnetizations, which differ from
+those of the bulk materials magnetite and maghemite of which they are made, on
+account of the combined non-trivial effects of temperature, inter-rod exchange,
+magnetostatic interactions and the degree of orientational order within the
+nanorod composites. The effective parameters allow treating the NPs as single
+macrospins, and we find for the test case of calculating loops for two aligned
+NPs that using the dipole approximation is sufficient for distances beyond 1.5
+times the NP diameter. We also present a study on relating integration time
+step to micromagnetic cell size, finding that the optimal time step size scales
+approximately linearly with cell volume.",2010.08848v1
+2020-11-12,Topological Hall effect arising from the mesoscopic and microscopic non-coplanar magnetic structure in MnBi,"The topological Hall effect (THE), induced by the Berry curvature, which
+originates from non-zero scalar spin chirality, is an important feature for
+mesoscopic topological structures, such as skyrmions. However, the THE might
+also arise from other microscopic non-coplanar spin structures in the lattice.
+Thus, the origin of the THE inevitably needs to be determined to fully
+understand skyrmions and find new host materials. Here, we examine the Hall
+effect in both bulk- and micron-sized lamellar samples of MnBi. The sample size
+affects the temperature and field range in which the THE is detectable.
+Although bulk sample exhibits the THE only upon exposure to weak fields in the
+easy-cone state, in thin lamella the THE exists across a wide temperature range
+and occurs at fields near saturation. Our results show that both the
+non-coplanar spin structure in the lattice and topologically non-trivial
+skyrmion bubbles are responsible for the THE, and that the dominant mechanism
+depends on the sample size. Hence, the magnetic phase diagram for MnBi is
+strongly size-dependent. Our study provides an example in which the THE is
+simultaneously induced by two mechanisms, and builds a bridge between
+mesoscopic and microscopic magnetic structures.",2011.06340v1
+2021-02-26,Non-Uniform Hysteresis in Small Clusters of Magnetic Nanoparticles,"Using first-principle calculations and kinetic Monte Carlo simulation, we
+study the local and averaged hysteresis in tiny clusters of k magnetic
+nanoparticles (MNPs) or k-mers. We also analyze the variation of local dipolar
+field acting on the constituent nanoparticles as a function of the external
+magnetic field. The dipolar interaction is found to promote chain-like
+arrangement in such a cluster. Irrespective of cluster size, the local
+hysteresis response depends strongly on the corresponding dipolar field acted
+on a nanoparticle. In a small k-mer, there is a wide variation in local
+hysteresis as a function of nanoparticle position. On the other hand, the local
+hysteresis is more uniform for larger k-mer, except for MNPs at the boundary.
+In the case of superparamagnetic nanoparticle and weak dipolar interaction, the
+local hysteresis loop area Ai is minimal and depends weakly on the k-mer size.
+While for ferromagnetic counterpart, Ai is considerably large even for weakly
+interacting MNPs. The value of Ai is found to be directly proportional to the
+dipolar field acting on the nanoparticle. The dipolar interaction and k-mer
+size also enhances the coercivity and remanence. There is always an increase in
+Ai with clutser size and dipolar interaction strength. Similarly, the averaged
+hysteresis loop area A also depends strongly on the k-mer size, particle size
+and dipolar interaction strength. A and Ai always increase with k-mer size and
+dipolar interaction strength. Interestingly, the value of A saturates for k>=20
+and considerable dipolar interaction irrespective of particle size. We believe
+that the present work would help understand the intricate role of dipolar
+interaction on hysteresis and organizational structure of MNPs and their usage
+in drug delivery and hyperthermia applications.",2102.13440v1
+2021-03-03,Cosmic ray protons and electrons from supernova remnants,"The spectrum of cosmic ray protons and electrons released by supernova
+remnants throughout their evolution is poorly known, because of the difficulty
+in accounting for particle escape and confinement in the downstream of a shock
+front, where both adiabatic and radiative losses are present. Here we calculate
+the spectrum of cosmic ray protons released during the evolution of supernovae
+of different types, accounting for the escape from upstream and for adiabatic
+losses of particles advected downstream of the shock and liberated at later
+times. The same calculation is carried out for electrons. The magnetic field in
+the post-shock region is calculated by using an analytic treatment of the
+magnetic field amplification due to non--resonant and resonant streaming
+instability and their saturation. We find that when the field is the result of
+the growth of the cosmic-ray--driven non--resonant instability alone, the
+spectrum of electrons and protons released by a supernova remnant are indeed
+different, but such a difference becomes appreciable only at energies $\gtrsim
+100-1000$ GeV, while observations of the electron spectrum require such a
+difference to be present at energies as low as $\sim 10$ GeV. An effect at such
+low energies requires substantial magnetic field amplification in the late
+stages of the supernova remnant evolution (shock velocity $\ll 1000$ km/s),
+perhaps not due to streaming instability but hydrodynamical processes. We
+comment on the feasibility of such conditions and speculate on the possibility
+that the difference in spectral shape between electrons and protons may reflect
+either some unknown acceleration effect, or additional energy losses in cocoons
+around the sources.",2103.02375v1
+2021-05-05,Phenomenological model for the third-harmonic magnetic response of superconductors: application to Sr$_{2}$RuO$_{4}$,"We employ the phenomenological Lawrence-Doniach model to compute the
+contributions of the superconducting fluctuations to the third-harmonic
+magnetic response, denoted here by $\overline{M_{3}}$, which can be measured in
+a precise way using ac magnetic fields and lock-in techniques. We show that, in
+an intermediate temperature regime, this quantity behaves as the third-order
+nonlinear susceptibility, which shows a power-law dependence with the reduced
+temperature $\epsilon=\frac{T-T_{c}}{T_{c}}$ as $\epsilon^{-5/2}$. Very close
+to $T_{c}$, however, $\overline{M_{3}}$ saturates due to the nonzero amplitude
+of the ac field. We compare our theoretical results with experimental data for
+three conventional superconductors -- lead, niobium, and vanadium -- and for
+the unconventional superconductor Sr$_{2}$RuO$_{4}$ (SRO). We find good
+agreement between theory and experiment for the elemental superconductors,
+although the theoretical values for the critical field systematically deviate
+from the experimental ones. In the case of SRO, however, the phenomenological
+model completely fails to describe the data, as the third-harmonic response
+remains sizable over a much wider reduced temperature range compared to Pb, Nb,
+and V. We show that an inhomogeneous distribution of $T_{c}$ can partially
+account for this discrepancy, since regions with a locally higher $T_{c}$
+contribute to the fluctuation $\overline{M_{3}}$ significantly more than
+regions with the ""nominal"" $T_{c}$ of the clean system. However, the
+exponential temperature dependence of $\overline{M_{3}}$ first reported in Ref.
+[3] is not captured by the model with inhomogeneity. We conclude that, while
+inhomogeneity is an important ingredient to understand the superconducting
+fluctuations of SRO and other perovskite superconductors, additional effects
+may be at play, such as non-Gaussian fluctuations or rare-region effects.",2105.01813v1
+2021-08-02,Large-amplitude longitudinal oscillations in solar prominences simulated with different resolutions,"Large-amplitude longitudinal oscillations (LALOs) in solar prominences have
+been widely studied in the last decades. However, their damping and
+amplification mechanisms are not well understood. In this study, we investigate
+the attenuation and amplification of LALOs using high-resolution numerical
+simulations with progressively increasing spatial resolutions. We performed
+time-dependent numerical simulations of LALOs using the 2D magnetic
+configuration that contains a dipped region. After the prominence mass loading
+in the magnetic dips, we triggered LALOs by perturbing the prominence mass
+along the magnetic field. We performed the experiments with four values of
+spatial resolution. In the simulations with the highest resolution, the period
+shows a good agreement with the pendulum model. The convergence experiment
+revealed that the damping time saturates at the bottom prominence region with
+improving the resolution, indicating the existence of a physical reason for the
+damping of oscillations. At the prominence top, the oscillations are amplified
+during the first minutes and then are slowly attenuated. The characteristic
+time suggests more significant amplification in the experiments with the
+highest spatial resolution. The analysis revealed that the energy exchange
+between the bottom and top prominence regions is responsible for the
+attenuation and amplification of LALOs. The high-resolution experiments are
+crucial for the study of the periods and the damping mechanism of LALOs. The
+period agrees with the pendulum model only when using high enough spatial
+resolution. The results suggest that numerical diffusion in simulations with
+insufficient spatial resolution can hide important physical mechanisms, such as
+amplification of oscillations.",2108.01143v1
+2021-08-20,Spectropolarimeter on-board the Aditya-L1: Polarization Modulation and Demodulation,"One of the major science goals of the Visible Emission Line Coronagraph
+(VELC) payload aboard the Aditya-L1 mission is to map the coronal magnetic
+field topology and the quantitative estimation of longitudinal magnetic field
+on routine basis. The infrared (IR) channel of VELC is equipped with a
+polarimeter to carry out full Stokes spectropolarimetric observations in the Fe
+XIII line at 1074.7~nm. The polarimeter is in dual-beam setup with continuously
+rotating waveplate as the polarization modulator. Detection of circular
+polarization due to Zeeman effect and depolarization of linear polarization in
+the presence of magnetic field due to saturated Hanle effect in the Fe~{\sc
+xiii} line require high signal-to-noise ratio (SNR). Due to limited number of
+photons, long integration times are expected to build the required SNR. In
+other words signal from a large number of modulation cycles are to be averaged
+to achieve the required SNR. This poses several difficulties. One of them is
+the increase in data volume and the other one is the change in modulation
+matrix in successive modulation cycles. The latter effect arises due to a
+mismatch between the retarder's rotation period and the length of the signal
+detection time in the case of VELC spectropolarimeter (VELC/SP). It is shown in
+this paper that by appropriately choosing the number of samples per half
+rotation the data volume can be optimized. A potential solution is suggested to
+account for modulation matrix variation from one cycle to the other.",2108.08997v1
+2021-09-13,Evolution of switchbacks in the inner Heliosphere,"We analyze magnetic field data from the first six encounters of PSP, three
+Helios fast streams and two Ulysses south polar passes covering heliocentric
+distances $0.1\lesssim R\lesssim 3$ au. We use this data set to statistically
+determine the evolution of switchbacks of different periods and amplitudes with
+distance from the Sun. We compare the radial evolution of magnetic field
+variances with that of the mean square amplitudes of switchbacks, and quantify
+the radial evolution of the cumulative counts of switchbacks per km. We find
+that the amplitudes of switchbacks decrease faster than the overall turbulent
+fluctuations, in a way consistent with the radial decrease of the mean magnetic
+field. This could be the result of a saturation of amplitudes and may be a
+signature of decay processes of large amplitude Alfv\'enic fluctuations in the
+solar wind. We find that the evolution of switchback occurrence in the solar
+wind is scale-dependent: the fraction of longer duration switchbacks increases
+with radial distance whereas it decreases for shorter switchbacks. This implies
+that switchback dynamics is a complex process involving both decay and in-situ
+generation in the inner heliosphere. We confirm that switchbacks can be
+generated by the expansion although other type of switchbacks generated closer
+to the sun cannot be ruled out.",2109.06341v1
+2021-10-01,Gate-tunable Intrinsic Anomalous Hall Effect in Epitaxial MnBi2Te4 Films,"Anomalous Hall effect (AHE) is an important transport signature revealing
+topological properties of magnetic materials and their spin textures. Recently,
+antiferromagnetic MnBi2Te4 has been demonstrated to be an intrinsic magnetic
+topological insulator that exhibits quantum AHE in exfoliated nanoflakes.
+However, its complicated AHE behaviors may offer an opportunity for the
+unexplored correlation between magnetism and band structure. Here, we show the
+Berry curvature dominated intrinsic AHE in wafer-scale MnBi2Te4 thin films. By
+utilizing a high-dielectric SrTiO3 as the back-gate, we unveil an ambipolar
+conduction and electron-hole carrier (n-p) transition in ~7 septuple layer
+MnBi2Te4. A quadratic relation between the saturated AHE resistance and
+longitudinal resistance suggests its intrinsic AHE mechanism. For ~3 septuple
+layer MnBi2Te4, however, the AHE reverses its sign from pristine negative to
+positive under the electric-gating. The first-principles calculations
+demonstrate that such behavior is due to the competing Berry curvature between
+polarized spin-minority-dominated surface states and spin-majority-dominated
+inner-bands. Our results shed light on the physical mechanism of the
+gate-tunable intrinsic AHE in MnBi2Te4 thin films and provide a feasible
+approach to engineering its AHE.",2110.00540v1
+2021-10-03,Chiral transport of hot carriers in graphene in the quantum Hall regime,"Photocurrent (PC) measurements can reveal the relaxation dynamics of
+photo-excited hot carriers beyond the linear response of conventional transport
+experiments, a regime important for carrier multiplication. In graphene subject
+to a magnetic field, PC measurements are able to probe the existence of Landau
+levels with different edge chiralities which is exclusive to relativistic
+electron systems. Here, we report the accurate measurement of PC in graphene in
+the quantum Hall regime. Prominent PC oscillations as a function of gate
+voltage on samples' edges are observed. These oscillation amplitudes form an
+envelope which depends on the strength of the magnetic field, as does the PCs'
+power dependence and their saturation behavior. We explain these experimental
+observations through a model using optical Bloch equations, incorporating
+relaxations through acoustic-, optical- phonons and Coulomb interactions. The
+simulated PC agrees with our experimental results, leading to a unified
+understanding of the chiral PC in graphene at various magnetic field strengths,
+and providing hints for the occurrence of a sizable carrier multiplication.",2110.01079v1
+2021-10-20,"Manifestations of Spinodal Decomposition into Dilute Pd$_{1-x}$Fe$_{x}$ ""Phases"" in Iron-Implanted Palladium Films: FMR Study","Palladium-iron alloys produced by high-dose implantation of iron ions into
+epitaxial palladium films were investigated with the ferromagnetic resonance
+(FMR) and vibrating sample magnetometry (VSM) techniques. The samples reveal
+distinct multiple FMR responses depending on the dose of iron ion implantation.
+The post-implantation annealing at 770 K does not bring the implanted films to
+a homogeneous solid solution state, as might be expected from the Pd-Fe phase
+diagram. On the contrary, the system approaches a stable state composed of
+several magnetic phases. FMR spectra exhibit an angular behavior specific for a
+stack of interacting magnetic layers. This observation, correlated with the
+magnetometry data, indicates that the palladium-iron binary alloy has a
+previously unknown tendency towards spinodal decomposition into isostructural
+phases with well-defined iron concentrations and, accordingly, with different
+temperatures of ferromagnetic ordering and saturation magnetizations.",2110.10397v1
+2021-11-25,Colossal Anomalous Hall Conductivity and Topological Hall Effect in Ferromagnetic Kagome Metal Nd$_3$Al,"Historically, the genesis of anomalous Hall effect (AHE) in magnetic
+materials has always been a fascinating yet controversial topic in the solid
+state physics community. Recent progress on the understanding of this topic has
+revealed an intimate connection between the Berry curvature of occupied
+electronic states and the intrinsic AHE. Magnetic Weyl semimetals with broken
+time reversal symmetry is a classic example, which is expected to show large
+contributions to Berry curvature around the topological nodes and hence to the
+AHE. Here, we report a kagome metallic ferromagnet Nd$_3$Al, with a large
+unconventional positive magnetoresistance (~ 80 %) and colossal anomalous Hall
+conductivity of 1.8x10^5 S/cm (largest ever reported to the best of our
+knowledge). We also show that the magnetic state of this compound is quite
+different from its analogues in many respects. While the compound is
+predominantly an itinerant ferromagnet, its low temperature phase exhibits
+topological band structure, enhanced skew scattering as well as topological
+spin texture arising in the spin frustrated kagome lattice. Various
+experimental findings such as topological Hall effect, non-saturating positive
+magnetoresistance etc. give strong indication to this scenario. Ab-initio
+calculations broadly confirm the experimental findings by revealing the
+presence of flat bands and Weyl points originating from the itinerant Nd
+moments. The non-trivial band structure, enhanced skew scattering and the spin
+texture in a clean polycrystalline sample are found be responsible for the
+colossal Hall conductivity and topological Hall effect.",2111.12944v1
+2021-11-26,Optical Stabilization of Fluctuating High Temperature Ferromagnetism in YTiO$_3$,"In quantum materials, degeneracies and frustrated interactions can have a
+profound impact on the emergence of long-range order, often driving strong
+fluctuations that suppress functionally relevant electronic or magnetic phases.
+Engineering the atomic structure in the bulk or at heterointerfaces has been an
+important research strategy to lift these degeneracies, but these equilibrium
+methods are limited by thermodynamic, elastic, and chemical constraints. Here,
+we show that all-optical, mode-selective manipulation of the crystal lattice
+can be used to enhance and stabilize high-temperature ferromagnetism in
+YTiO$_3$, a material that exhibits only partial orbital polarization, an
+unsaturated low-temperature magnetic moment, and a suppressed Curie
+temperature, $T_c$ = 27 K. The enhancement is largest when exciting a 9 THz
+oxygen rotation mode, for which complete magnetic saturation is achieved at low
+temperatures and transient ferromagnetism is realized up to $T_{neq} >$ 80 K,
+nearly three times the thermodynamic transition temperature. First-principles
+and model calculations of the nonlinear phonon-orbital-spin coupling reveal
+that these effects originate from dynamical changes to the orbital polarization
+and the makeup of the lowest quasi-degenerate Ti $t_{2g}$ levels. Notably,
+light-induced high temperature ferromagnetism in YTiO$_3$ is found to be
+metastable over many nanoseconds, underscoring the ability to dynamically
+engineer practically useful non-equilibrium functionalities.",2111.13622v1
+2021-11-28,CoFeVSb: A Promising Candidate for Spin Valve and Thermoelectric Applications,"We report a combined theoretical and experimental study of a novel quaternary
+Heusler system CoFeVSb from the view point of room temperature spintronics and
+thermoelectric applications. It crystallizes in cubic structure with small
+DO$_3$-type disorder. The presence of disorder is confirmed by room temperature
+synchrotron X-ray diffraction(XRD) and extended X-ray absorption fine structure
+(EXAFS) measurements. Magnetization data reveal high ordering temperature with
+a saturation magnetization of 2.2 $\mu_B$/f.u. Resistivity measurements reflect
+half-metallic nature. Double hysteresis loop along with asymmetry in the
+magnetoresistance(MR) data reveals room temperature spin-valve feature, which
+remains stable even at 300 K. Hall measurements show anomalous behavior with
+significant contribution from intrinsic Berry phase. This compound also large
+room temperature power factor ($\sim0.62$ mWatt/m/K$^{2}$) and ultra low
+lattice thermal conductivity ($\sim0.4$ W/m/K), making it a promising candidate
+for thermoelectric application. Ab-initio calculations suggest weak
+half-metallic behavior and reduced magnetization (in agreement with experiment)
+in presence of DO$_3$ disorder. We have also found an energetically competing
+ferromagnetic FM)/antiferromagnetic (AFM) interface structure within an
+otherwise FM matrix: one of the prerequisites for spin valve behavior.
+Coexistence of so many promising features in a single system is rare, and hence
+CoFeVSb gives a fertile platform to explore numerous applications in future.",2111.14081v1
+2022-02-02,Universal Scaling Laws for Solar and Stellar Atmospheric Heating,"The Sun and sun-like stars commonly host the multi-million-Kelvin coronae and
+the 10,000-Kelvin chromospheres. These extremely hot gases generate X-ray and
+Extreme Ultraviolet emissions that may impact the erosion and chemistry of
+(exo)planetary atmospheres, influencing the climate and conditions of
+habitability. However, the mechanism of coronal and chromospheric heating is
+still poorly understood. While the magnetic field most probably plays a key
+role in driving and transporting energy from the stellar surface upwards, it is
+not clear if the atmospheric heating mechanisms of the Sun and active sun-like
+stars can be described in a unified manner. To this end, we report on a
+systematic survey of the responses of solar and stellar atmospheres to surface
+magnetic flux over a wide range of temperatures. By analyzing 10 years of
+multi-wavelength synoptic observations of the Sun, we reveal that the
+irradiance and magnetic flux show power-law relations with an exponent
+decreasing from above- to sub-unity as the temperature decreases from the
+corona to the chromosphere. Moreover, this trend indicating the efficiency of
+atmospheric heating can be extended to sun-like stars. We also discover that
+the power-law exponent has a solar cycle dependence, where it becomes smallest
+at activity maximum, probably due to the saturation of atmospheric heating. Our
+study provides observational evidence that the mechanism of atmospheric heating
+is universal among the Sun and sun-like stars, regardless of age or activity.",2202.01232v2
+2022-02-10,Landau parameters and entrainment matrix of cold stellar matter: effect of the symmetry energy and strong magnetic fields,"Nuclear matter properties based on a relativistic approach suitable for the
+description of multi-component systems are calculated. We use a set of nuclear
+relativistic mean-field models that satisfy acceptable nuclear matter
+properties and neutron star observations. The effects of the density dependence
+of the symmetry energy and of the Landau quantization due to the presence of a
+strong external magnetic field are discussed. Properties such as the proton
+fraction, the Landau mass, Landau parameters and entrainment matrix, the
+adiabatic index and speed of sound are calculated for cold $\beta$-equilibrium
+matter. A large dispersion on the calculated properties is obtained at two to
+three times saturation density $\rho_0 $. The proton Landau mass can be as low
+as one third of the vacuum nucleon mass at 2-3$~\rho_0 $. Similar effects are
+obtained for the Landau parameters, in particular, the ones involving protons,
+where the relative dispersion of $F^0_{pp}$ and $F^1_{pp}$ is as high as 30\%
+to 50\% at 2-3$~\rho_0 $. These parameters are particularly sensitive to the
+symmetry energy. The effect of the magnetic field on the nuclear properties is
+small for fields as high as 10$^{18}$G except for a small range of densities
+just above the crust-core transition. Tables with the EoS, and the parameters,
+are provided in the Supplementary Material section.",2202.05231v1
+2022-04-04,"Magnetocaloric properties of $R_3$Ga$_5$O$_{12}$ ($R$ = Tb,Gd,Nd,Dy)","We report the characteristic magnetic properties of several members of the
+rare-earth garnet family, Gd$_3$Ga$_5$O$_{12}$ (GGG), Dy$_3$Ga$_5$O$_{12}$
+(DGG), Tb$_3$Ga$_5$O$_{12}$ (TGG), and Nd$_3$Ga$_5$O$_{12}$ (NGG), and compare
+their relative potential utility for magnetocaloric cooling, including their
+minimal adiabatic demagnetization refrigeration (ADR) temperatures and relative
+cooling parameters. A main objective of this work concerns the identification
+of potential improvements over the magnetocaloric properties of GGG for use in
+low temperature ADR cryostats. Using Tb$^{+3}$ and Dy$^{+3}$ in the rare-earth
+site offers, in principle, a higher saturation magnetization and Nd$^{+3}$
+gives a lower de Gennes factor and therefore potentially reduced magnetic
+transition temperatures, limiting the useful temperature range. Our results
+show that Dy$_3$Ga$_5$O$_{12}$ yields an optimal relative cooling parameter
+($RCP$) at low applied fields and low limiting temperatures, which would allow
+for the design of more efficient ADR cryostats.",2204.01752v2
+2022-07-29,Precision Measurement of the Excited State Landé g-factor and Diamagnetic Shift of the Cesium D$_{2}$ Line,"We have performed saturated absorption spectroscopy on the cesium D$_{2}$
+line in 3 T and 7 T magnetic fields. By means of sideband spectroscopy on the
+extreme angular momentum states we have measured the linear magnetic frequency
+shift of the transition to be $\gamma_1 = 13.994\:301(11)$ GHz/T. This
+corresponds to an optical magnetic field measurement of better than 1 ppm
+accuracy. From this value we can calculate the fine structure Land\'e g-factor
+$g_J\left(6^2P_{3/2}\right) = 1.334\:087\:49(52)$. This is consistent with the
+previous best measurement, and improves the accuracy by more than two orders of
+magnitude. We have also measured, for the first time ever, the quadratic
+diamagnetic shift as $\gamma_2 = 0.4644(35)\:\mathrm{MHz/T^2}$. Our work opens
+up the field of accurate high field optical magnetometry using atomic cesium.
+These high accuracy measurements also allow for testing of advanced atomic
+structure models, as our results are incompatible with the Russel-Saunders
+coupling value, and the hydrogen-constant-core-model value, by 31 and 7
+standard deviations respectively.",2208.00077v1
+2022-12-20,Efficient and all-carbon electrical readout of a NV based quantum sensor,"The spin readout of an ensemble of nitrogen-vacancy (NV) centers in diamond
+can be realized by a photoconductive detection that is a complementary method
+to the optical detection of the NV electron spin magnetic resonance. Here, we
+implement the photoconductive detection through graphitic planar electrodes
+that collect the photocurrent. Graphitic electrodes are patterned using a xenon
+Focused-Ion Beam on an Optical-Grade quality diamond crystal containing a
+nitrogen concentration of ~1 ppm and a NV concentration of a few ppb.
+Resistance and current-voltage characteristics of the NV-doped diamond junction
+are investigated tuning the 532 nm pump beam intensity. The junction has an
+ohmic behavior and under a strong bias field, we observe velocity saturation of
+the optically-induced carriers in the diamond junction. We perform the
+photoconductive detection in continuous-wave regime of the magnetic resonance
+of the NV centers ensemble for a magnetic field applied along the <100> and the
+<111> direction with a magnitude above 100 mT. This technique enables the
+realization of all-carbon diamond quantum sensors integrating graphitic
+microstructures for the electrical readout.",2212.10349v1
+2023-04-26,Assessment of sol-gel derived iron oxide substituted 45S5 bioglass-ceramics for biomedical applications,"Magnetic bioactive glass ceramic (MGC) powders have been synthesized by sol
+gel route by systematically substituting silicon dioxide with iron oxide in the
+45S5 glass composition. Powder x-ray diffraction studies revealed a variation
+in the percentage of combeite (Ca$_2$Na$_2$Si$_3$O$_9$), magnetite
+(Fe$_3$O$_4$), and hematite (Fe$_2$O$_3$) nanocrystalline phases in MGC powders
+as a function of composition. Zeta potential measurements showed that MGC
+containing up to 10 wt.% iron oxide formed stable suspensions. Saturation
+magnetization and heat generation capacity of MGC fluids increased with
+increase in iron oxide content. Degradation of MGC powders was investigated in
+phosphate buffer saline (PBS). In vitro bioactivity of the MGC powders taken in
+pellet form was confirmed by observing the pH variation as well as
+hydroxyapatite layer (HAp) formation upon soaking in modified simulated body
+fluid. These studies showed a decrement in overall bioactivity in samples with
+high iron oxide content due to the proportional decrease in silanol group.
+Monitoring the proliferation of MG-63 osteoblast cell in Dulbecco's Modified
+Eagle Medium (DMEM) revealed that MGC with up to 10 wt.% iron oxide exhibited
+acceptable viability. The systematic study revealed that the MGC with 10 wt.%
+iron oxide exhibited optimal cell viability, magnetic properties and induction
+heating capacity which were better than those of FluidMag-CT, which is used for
+hyperthermia treatment.",2304.13437v1
+2023-06-28,Emergent criticality in fully frustrated quantum magnets,"Phase transitions in condensed matter are often linked to exotic emergent
+properties. We study the fully frustrated bilayer Heisenberg antiferromagnet to
+demonstrate that an applied magnetic field creates a novel emergent
+criticality. The quantum phase diagram contains four states, the DS (singlets
+on every interlayer dimer bond), DTAF (all triplets with antiferromagnetic
+order), TC (a singlet-triplet checkerboard) and FM (saturated ferromagnet). The
+thermal phase diagram is dominated by a wall of discontinuities extending from
+the zero-field DTAF-DS transition to a quantum critical endpoint where the
+field drives the DTAF and TC into the FM. This first-order wall is terminated
+at finite temperatures by a line of critical points, where the
+Berezinskii-Kosterlitz-Thouless (BKT) transition of the DTAF and the thermal
+Ising transition of the TC also terminate. We demonstrate by quantum Monte
+Carlo simulations that the BKT transition does not change the Ising nature of
+the DTAF-DS critical line. By contrast, the combination of symmetries merging
+on the multicritical DTAF-TC line leads to a 4-state Potts universality not
+contained in the microscopic Hamiltonian, which we associate with the
+Ashkin-Teller model. Our results represent a systematic step in understanding
+emergent phenomena in quantum magnetic materials including the
+``Shastry-Sutherland compound'' SrCu$_2$(BO$_3$)$_2$.",2306.16288v1
+2023-07-10,3D Simulations of Magnetoconvection in a Rapidly Rotating Supernova Progenitor,"We present a first 3D magnetohydrodynamic (MHD) simulation of oxygen, neon
+and carbon shell burning in a rapidly rotating 16 M_sun core-collapse supernova
+progenitor. We also run a purely hydrodynamic simulation for comparison. After
+180s (15 and 7 convective turnovers respectively), the magnetic fields in the
+oxygen and neon shells achieve saturation at 10^{11}G and 5 x 10^{10}G. The
+strong Maxwell stresses become comparable to the radial Reynolds stresses and
+eventually suppress convection. The suppression of mixing by convection and
+shear instabilities results in the depletion of fuel at the base of the burning
+regions, so that the burning shell eventually move outward to cooler regions,
+thus reducing the energy generation rate. The strong magnetic fields
+efficiently transport angular momentum outwards, quickly spinning down the
+rapidly rotating convective oxygen and neon shells and forcing them into rigid
+rotation. The hydrodynamic model shows complicated redistribution of angular
+momentum and develops regions of retrograde rotation at the base of the
+convective shells. We discuss implications of our results for stellar evolution
+and for the subsequent core-collapse supernova. The rapid redistribution of
+angular momentum in the MHD model casts some doubt on the possibility of
+retaining significant core angular momentum for explosions driven by
+millisecond magnetars. However, findings from multi-D models remain tentative
+until stellar evolution calculations can provide more consistent rotation
+profiles and estimates of magnetic field strengths to initialise multi-D
+simulations without substantial numerical transients. We also stress the need
+for longer simulations, resolution studies, and an investigation of non-ideal
+effects.",2307.04833v2
+2023-07-12,BMS$_{3}$ (Carrollian) field theories from a bound in the coupling of current-current deformations of CFT$_{2}$,"Two types of Carrollian field theories are shown to emerge from finite
+current-current deformations of toroidal CFT$_{2}$'s when the deformation
+coupling is precisely fixed, up to a sign. In both cases the energy and
+momentum densities fulfill the BMS$_{3}$ algebra. Applying these results to the
+bosonic string, one finds that the electric-like deformation (positive
+coupling) reduces to the standard tensionless string. The magnetic-like
+deformation (negative coupling) yields to a new theory, still being
+relativistic, devoid of tension and endowed with an ""inner Carrollian
+structure"". Classical solutions describe a sort of ""self-interacting null
+particle"" moving along generic null curves of the original background metric,
+not necessarily geodesics. This magnetic-like theory is also shown to be
+recovered from inequivalent limits in the tension of the bosonic string.
+Electric- and magnetic-like deformations of toroidal CFT$_{2}$'s can be seen to
+correspond to limiting cases of continuous exactly marginal (trivial)
+deformations spanned by an SO(1,1) automorphism of the current algebra. Thus,
+the absolute value of the current-current deformation coupling is shown to be
+bounded. When the bound saturates, the deformation ceases to be exactly
+marginal, but still retains the full conformal symmetry in two alternative
+ultrarelativistic regimes.",2307.06367v2
+2023-08-08,Ionically-Driven Synthesis and Exchange Bias in Mn$_{4}$N/MnN$_{x}$ Heterostructures,"Ferrimagnets have received renewed attention as a promising platform for
+spintronic applications. Of particular interest is the Mn4N from the
+${\epsilon}$-phase of the manganese nitride as an emergent rare-earth-free
+spintronic material due to its perpendicular magnetic anisotropy, small
+saturation magnetization, high thermal stability, and large domain wall
+velocity. We have achieved high-quality (001)-ordered Mn$_{4}$N thin film by
+sputtering Mn onto ${\eta}$-phase Mn$_{3}$N$_{2}$ seed layers on Si substrates.
+As the deposited Mn thickness varies, nitrogen ion migration across the
+Mn$_{3}$N$_{2}$/Mn layers leads to a continuous evolution of the layers to
+Mn$_{3}$N$_{2}$/Mn$_{2}$N/Mn$_{4}$N, Mn$_{2}$N/Mn$_{4}$N, and eventually
+Mn$_{4}$N alone. The ferrimagnetic Mn$_{4}$N indeed exhibits perpendicular
+magnetic anisotropy, and forms via a nucleation-and-growth mechanism. The
+nitrogen ion migration is also manifested in a significant exchange bias, up to
+0.3 T at 5 K, due to the interactions between ferrimagnetic Mn$_{4}$N and
+antiferromagnetic Mn$_{3}$N$_{2}$ and Mn$_{2}$N. These results demonstrate a
+promising all-nitride magneto-ionic platform with remarkable tunability for
+device applications.",2308.04274v2
+2023-08-25,Evidence of the Coulomb gap in the density of states of MoS$_2$,"$\mathrm{MoS_2}$ is an emergent van der Waals material that shows promising
+prospects in semiconductor industry and optoelectronic applications. However,
+its electronic properties are not yet fully understood. In particular, the
+nature of the insulating state at low carrier density deserves further
+investigation, as it is important for fundamental research and applications. In
+this study, we investigate the insulating state of a dual-gated exfoliated
+bilayer $\mathrm{MoS_2}$ field-effect transistor by performing magnetotransport
+experiments. We observe positive and non-saturating magnetoresistance, in a
+regime where only one band contributes to electron transport. At low electron
+density ($\sim 1.4\times 10^{12}~\mathrm{cm^{-2}}$) and a perpendicular
+magnetic field of 7 Tesla, the resistance exceeds by more than one order of
+magnitude the zero field resistance and exponentially drops with increasing
+temperature. We attribute this observation to strong electron localization.
+Both temperature and magnetic field dependence can, at least qualitatively, be
+described by the Efros-Shklovskii law, predicting the formation of a Coulomb
+gap in the density of states due to Coulomb interactions. However, the
+localization length obtained from fitting the temperature dependence exceeds by
+more than one order of magnitude the one obtained from the magnetic field
+dependence. We attribute this discrepancy to the presence of a nearby metallic
+gate, which provides electrostatic screening and thus reduces long-range
+Coulomb interactions. The result of our study suggests that the insulating
+state of $\mathrm{MoS_2}$ originates from a combination of disorder-driven
+electron localization and Coulomb interactions.",2308.13337v2
+2023-09-24,Novel one-pot sol-gel synthesis route of Fe3C/few-layered graphene core/shell nanoparticles embedded in a carbon matrix,"Fe3C/few-layered graphene core/shell nanoparticles embedded in a carbon
+matrix are synthesized by a novel two-step surfactant sol-gel strategy, where
+the processes of hydrolysis, polycondensation and drying take place in a
+one-pot. The present approach is based on the combined action of oleic acid and
+oleylamine, which act sterically on the precursor micelles when a densification
+temperature is performed in a reducing atmosphere. The structural and magnetic
+evolution of the formed compounds is investigated, ranging from iron oxides
+such as Fe3O4 and FeO, to the formation of pure Fe3C/C samples from 700 {\deg}C
+onwards. Interestingly, Fe3C nanoparticles with a size of ~20 nm crystallize
+immersed in the carbon matrix and the surrounding environment forms an oriented
+encapsulation built by few-layered graphene. The nanostructures show a
+saturation magnetization of ~43 emu/g and a moderate coercivity of ~500 Oe.
+Thereby, an innovative chemical route to produce single phase Fe3C
+nanoparticles is described, and an effective method of few-layered graphene
+passivation is proposed, yielding a product with a high magnetic response and
+high chemical stability against environmental corrosion.",2309.15858v1
+2023-11-10,Enhancement of optical absorption in multiferroic (1-x)PZT-xPFN thin films: Experiments and first-principles analysis,"Multiferroic compounds have gained research attention in the field of
+ferroelectric photovoltaics due to the presence of transition-metal d states
+from magnetic ions, which tend to reduce the bandgap value. In this work,
+0.5Pb(Zr0.52Ti0.48)O3 - 0.5Pb(Fe0.5Nb0.5)O3 PZTFN0.5 thin films were
+synthesized using a sol-gel route to investigate the effect of iron doping on
+optical and multiferroic properties. For comparative analysis, the end-member
+compositions, Pb(Zr0.52Ti0.48)O3 (PZT) and Pb(Fe0.5Nb0.5)O3 (PFN), were also
+synthesized under identical conditions. Our results revealed that the presence
+of Fe ions, besides inducing multiferroic behavior, effectively enhances the
+optical absorption of the material in the visible light region. Optical
+transitions at 3.0 eV (2.4 eV) and 2.7 eV (2.2 eV) for the direct (indirect)
+bandgap were determined for PZTFN0.5 and PFN, respectively, indicating that the
+absorption edges of the iron-containing films result more promising than PZT
+(Eg 3.6eV) for photovoltaic applications. Both PZTFN0.5 and PFN thin films
+exhibit multiferroic behavior at room temperature, with different electric and
+magnetic properties. While PZTFN0.5 presents saturated hysteresis loops with
+remanent polarization values around 10 uC/cm2 and magnetization of 1.6 emu/cm2,
+PFN displays significantly larger remanence (31 emu/cm2) but poorer
+ferroelectric properties due to the presence of leakage. Microscopic insights
+into the structural and electronic properties of the PZTFN0.5 solid solution
+were provided from first-principles calculations.",2311.05855v1
+2023-11-15,Growth and Characterization of $β$-Mn Structured CoZn Thin Films,"Thin films of polycrystalline $\beta$-Mn structure CoZn have been grown on
+thermally oxidized Si substrates by co-sputtering from elemental targets
+followed by annealing. A range of films grown with variable Co deposition power
+and fixed Zn deposition power were produced, so as to vary the proportions of
+the two elements reaching the substrate, which were annealed post-growth.
+Whilst all films exhibited a (211) $\beta$-Mn structure CoZn texture in X-ray
+diffraction, transmission electron microscopy showed that the composition with
+the highest integrated intensity for that Bragg peak contained large vacancies
+and was covered by a thick ZnO cap owing to being Co-deficient overall. CoZn
+films deposited at ratios tuned to give the optimal volume fraction of
+$\beta$-Mn were continuous, with crystallites up to 200~nm in size, with a much
+thinner ZnO cap layer. Magnetic measurements show that such optimal CoZn films
+have a Curie temperature $T_\mathrm{C} \sim 420$~K and saturation magnetization
+of 120~emu/cm$^3$, properties close to those reported for bulk crystals. The
+$\beta$-Mn structure is chiral (P4$_{1}$32/P4$_{3}$32 space group) and is known
+to give rise to a Dzyaloshinkii-Moriya interaction (DMI) that stabilizes
+room-temperature skyrmions in the bulk. Our thin films are thus a potential
+materials platform, compatible with planar processing technology, for magnetic
+skyrmions arising from a bulk DMI.",2311.08824v2
+2023-12-03,Experimental apparatus for non-contact resistivity measurements of the rock core plug based on magnetic induction,"A new apparatus has been developed to measure the conductivity of rock
+samples. The probe, which consists of multi-coil transmitters and receivers
+doesn't require physical contact with the samples. The measurement is based on
+the induction principle. The measurement system is validated by using saline
+solutions and water-saturated sands of known conductivity. This work presents
+details of the development of a system of magnetic resistivity measurements by
+magnetic induction for petrophysical applications. The first application
+consists of measuring the resistivity of the core plug which is 0.038 m in
+diameter. Currently the system is operating properly at a frequency of 50 kHz
+with a current of up to 500 mA at 20 {\deg}C. During the study two types of
+samples were investigated: aqueous solutions with conductivities between 1 to
+100 mS/cm and rocks. Several tests were carried out with the objective of
+investigating the performance of the instrument, such as the experiment to
+obtain sensitivity for the measurement system as a function of the current
+applied to the transmitter coil.",2312.01375v1
+2024-02-01,Quasi-perpendicular shocks of galaxy clusters in hybrid kinetic simulations: The structure of the shocks,"Context: Cosmic ray acceleration in galaxy clusters is still an ongoing
+puzzle, with relativistic electrons forming radio relics at merger shocks and
+emitting synchrotron radiation. In the present work we perform hybrid-kinetic
+simulations in a range of various quasi-perpendicular foreshock conditions,
+including plasma beta, magnetic obliquity, and the shock Mach number. Aims: We
+study the ion kinetic physics, responsible for the shock structure and wave
+turbulence, that in turn affects the particle acceleration processes. Methods:
+We apply a recently developed generalized fluid-particle hybrid numerical code
+that can combine fluid modeling for both kinetic ions and fluid electrons. The
+model utilizes the exact form of the generalized Ohm's law, allowing for
+arbitrary choice of mass and energy densities, as well as the charge-to-mass
+ratio of the kinetic species. Results: We show that the properties of
+ion-driven multi-scale magnetic turbulence in merger shocks are in agreement
+with the ion structures observed in PIC simulations. In typical shocks with the
+sonic Mach number $M_s=3$, the magnetic structures and shock front density
+ripples grow and saturate at wavelengths reaching approximately four ion Larmor
+radii. Finally, we note that the steady-state structure of $M_s=3$ shocks in
+high-beta plasmas shows evidence that there is little difference between 2D and
+3D simulations. The turbulence near the shock front seems to be a 2D-like
+structure in 3D simulations.",2402.00571v1
+2024-02-22,Revisiting thermoelectric effects in the crust of neutron stars,"Context. Large thermal variations have been observed in neutron stars that
+typically are not aligned with density gradients. Such terms may activate the
+Biermann battery effect, leading to thermo-electric interactions and the
+generation of electromotive force. Aims. We aim to identify the impact a
+temperature anisotropy on a neutron star's crust can have in the evolution of
+its magnetic field, through the thermo-electric terms. Methods. We consider a
+neutron star crust with large temperature gradients, associated with long-lived
+hot spots, described by a Gaussian-type function localized. We simulate the
+interplay between the battery term and the Hall and Ohmic evolution
+numerically, for axisymmetric systems. Results. The results indicate that for
+crust temperatures of $\sim$$10^9$ K the toroidal field can be amplified up to
+$\sim$$10^{14}$ - $10^{15}$ G near the points of maximum temperature gradients,
+and it locally changes the architecture of the poloidal field lines. For
+internal crustal temperatures around $\sim$$10^8$ K, the temperature gradient
+generates fields of about two orders of magnitude lower. In such cases,
+saturation is achieved after some hundred thousand years, after which the
+battery and Ohmic dissipation balance each other. Conclusions. We conclude that
+the thermoelectric effect can impact the overall magnetic field evolution,
+provided that the thermal gradient is maintained for a sufficiently long time.
+Neutron stars endowned with moderate strength magnetic fields may be affected
+by the thermoelectric effect if the hotspots survive for timescales of a few
+kiloyears.",2402.14911v1
+2020-10-16,Saturation problems about forbidden $0$-$1$ submatrices,"A $0$-$1$ matrix $M$ is saturating for a $0$-$1$ matrix $P$ if $M$ does not
+contain a submatrix that can be turned into $P$ by changing some $1$ entries to
+$0$ entries, and changing an arbitrary $0$ to $1$ in $M$ introduces such a
+submatrix in $M$. In saturation problems for $0$-$1$ matrices we are interested
+in estimating the minimum number of $1$ entries in an $m \times n$ matrix that
+is saturating for $P$, in terms of $m$ and $n$.
+  In other words, we wish to give good estimates for the saturation function of
+$P$. Recently, Brualdi and Cao initiated the study of saturation problems in
+the context of $0$-$1$ matrices.
+  We extend their work in several directions. We prove that every $0$-$1$
+forbidden matrix has its saturation function either in $\Theta(1)$ or
+$\Theta(n)$ in the case when we restrict ourselves to square saturating
+matrices. Then we give a partial answer to a question posed by Brualdi and Cao
+about the saturation function of $J_k$, which is obtained from the identity
+matrix $I_k$ by putting the first row after the last row. Furthermore, we
+exhibit a $5\times 5$ permutation matrix with the saturation function bounded
+from the above by a fixed constant. We complement this result by identifying
+large classes of $0$-$1$ matrices with linear saturation function. Finally, we
+completely resolve the related semisaturation problem as far as the constant
+vs. linear dichotomy is concerned.",2010.08256v2
+2002-11-04,X-rays in the Orion Nebula Cluster: Constraints on the origins of magnetic activity in pre-main sequence stars,"A recent Chandra/ACIS observation of the Orion Nebula Cluster detected 1075
+sources (Feigelson et al. 2002), providing a uniquely large and well-defined
+sample to study the dependence of magnetic activity on bulk properties for
+stars descending the Hayashi tracks. The following results are obtained: (1)
+X-ray luminosities L_t in the 0.5-8 keV band are strongly correlated with
+bolometric luminosity with <log L_t/L_bol> = -3.8 for stars with masses 0.7<M<2
+Mo, an order of magnitude below the main sequence saturation level; (2) the
+X-ray emission drops rapidly below this level in some or all stars with 2<M<3
+Mo; (3) the presence or absence of infrared circumstellar disks has no apparent
+relation to X-ray levels; and (4) X-ray luminosities exhibit a slight rise as
+rotational periods increase from 0.4 to 20 days. This last finding stands in
+dramatic contrast to the strong anticorrelation between X-rays and period seen
+in main sequence stars.
+  The absence of a strong X-ray/rotation relationship in PMS stars, and
+particularly the high X-ray values seen in some very slowly rotating stars, is
+a clear indication that the mechanisms of magnetic field generation differ from
+those operating in main sequence stars. The most promising possibility is a
+turbulent dynamo distributed throughout the deep convection zone, but other
+models such as alpha-Omega dynamo with `supersaturation' or relic core fields
+are not immediately excluded. The drop in magnetic activity in
+intermediate-mass stars may reflect the presence of a significant radiative
+core. The evidence does not support X-ray production in large-scale star-disk
+magnetic fields.",0211049v1
+2002-11-27,Asymmetric Explosions of Thermonuclear Supernovae,"A type Ia supernova explosion starts in a white dwarf as a laminar
+deflagration at the center of the star and soon several hydrodynamic
+instabilities (in particular, the Rayleigh-Taylor (R-T) instability) begin to
+act. In previous work (Ghezzi, de Gouveia Dal Pino, & Horvath 2001), we
+addressed the propagation of an initially laminar thermonuclear flame in
+presence of a magnetic field assumed to be dipolar. We were able to show that,
+within the framework of a fractal model for the flame velocity, the front is
+affected by the field through the quenching of the R-T instability growth in
+the direction perpendicular to the field lines. As a consequence, an asymmetry
+develops between the magnetic polar and the equatorial axis that gives a
+prolate shape to the burning front. We have here computed numerically the total
+integrated asymmetry as the flame front propagates outward through the
+expanding shells of decreasing density of the magnetized white dwarf
+progenitor, for several chemical compositions, and found that a total asymmetry
+of about 50 % is produced between the polar and equatorial directions for
+progenitors with a surface magnetic field B ~ 5 x 10^{7} G, and a composition
+C12 = 0.2 and O16 = 0.8 (in this case, the R-T instability saturates at scales
+\~ 20 times the width of the flame front). This asymmetry is in good agreement
+with the inferred asymmetries from spectropolarimetric observations of very
+young supernova remnants, which have recently revealed intrinsic linear
+polarization interpreted as evidence of an asymmetric explosion in several
+objects,such as SN1999by, SN1996X, and SN1997dt. Larger magnetic field
+strengths will produce even larger asymmetries. We have also found that for
+lighter progenitors the total asymmetry is larger.",0211605v2
+2007-06-13,Simulations of the Poynting--Robertson Cosmic Battery in Resistive Accretion Disks,"We describe the results of numerical ""2.5--dimensional"" MHD simulations of an
+initially unmagnetized disk model orbiting a central point--mass and responding
+to the continual generation of poloidal magnetic field due to a secular source
+that emulates the Poynting--Robertson (PR) drag on electrons in the vicinity of
+a luminous stellar or compact accreting object. The fluid in the disk and in
+the surrounding hotter atmosphere has finite electrical conductivity and allows
+for the magnetic field to diffuse freely out of the areas where it is
+generated, while at the same time, the differential rotation of the disk twists
+the poloidal field and quickly induces a substantial toroidal--field component.
+The secular PR term has dual purpose in these simulations as the source of the
+magnetic field and the trigger of a magnetorotational instability (MRI) in the
+disk. The MRI is especially mild and does not destroy the disk because a small
+amount of resistivity dampens the instability efficiently. In simulations with
+moderate resistivities (diffusion timescales up to $\sim$16 local dynamical
+times) and after $\sim$100 orbits, the MRI has managed to transfer outward
+substantial amounts of angular momentum and the inner edge of the disk, along
+with azimuthal magnetic flux, has flowed toward the central point--mass where a
+new, magnetized, nuclear disk has formed. The toroidal field in this nuclear
+disk is amplified by differential rotation and it cannot be contained; when it
+approaches equipartition, it unwinds vertically and produces episodic jet--like
+outflows. The poloidal field in the inner region cannot diffuse back out if the
+characteristic diffusion time is of the order of or larger than the dynamical
+time; it continues to grow linearly in time undisturbed and without saturation,
+as the outer sections of many poloidal loops are being drawn radially outward.",0706.3187v1
+2009-10-02,"On the room temperature multiferroic BiFeO3: Magnetic, dielectric and thermal properties","Magnetic dc susceptibility between 1.5 and 800 K, ac susceptibility and
+magnetization, thermodynamic properties, temperature dependence of radio and
+audio-wave dielectric constants and conductivity, contact-free dielectric
+constants at mm-wavelengths, as well as ferroelectric polarization are reported
+for single crystalline BiFeO3. A well developed anomaly in the magnetic
+susceptibility signals the onset of antiferromagnetic order close to 635 K.
+Beside this anomaly no further indications of phase or glass transitions are
+indicated in the magnetic dc and ac susceptibilities down to the lowest
+temperatures. The heat capacity has been measured from 2 K up to room
+temperature and significant contributions from magnon excitations have been
+detected. From the low-temperature heat capacity an anisotropy gap of the
+magnon modes of the order of 6 meV has been determined. The dielectric
+constants measured in standard two-point configuration are dominated by
+Maxwell-Wagner like effects for temperatures T > 300 K and frequencies below 1
+MHz. At lower temperatures the temperature dependence of the dielectric
+constant and loss reveals no anomalies outside the experimental errors,
+indicating neither phase transitions nor strong spin phonon coupling. The
+temperature dependence of the dielectric constant was measured contact free at
+microwave frequencies. At room temperature the dielectric constant has an
+intrinsic value of 53. The loss is substantial and strongly frequency dependent
+indicating the predominance of hopping conductivity. Finally, in small thin
+samples we were able to measure the ferroelectric polarization between 10 and
+200 K. The saturation polarization is of the order of 40 microC/cm^2,
+comparable to reports in literature.",0910.0385v2
+2011-05-09,Turbulence in Global Simulations of Magnetized Thin Accretion Disks,"We use a global magnetohydrodynamic simulation of a geometrically thin
+accretion disk to investigate the locality and detailed structure of turbulence
+driven by the magnetorotational instability (MRI). The model disk has an aspect
+ratio $H / R \simeq 0.07$, and is computed using a higher-order Godunov MHD
+scheme with accurate fluxes. We focus the analysis on late times after the
+system has lost direct memory of its initial magnetic flux state. The disk
+enters a saturated turbulent state in which the fastest growing modes of the
+MRI are well-resolved, with a relatively high efficiency of angular momentum
+transport $< < \alpha > > \approx 2.5 \times 10^{-2}$. The accretion stress
+peaks at the disk midplane, above and below which exists a moderately
+magnetized corona with patches of superthermal field. By analyzing the spatial
+and temporal correlations of the turbulent fields, we find that the spatial
+structure of the magnetic and kinetic energy is moderately well-localized (with
+correlation lengths along the major axis of $2.5H$ and $1.5H$ respectively),
+and generally consistent with that expected from homogenous incompressible
+turbulence. The density field, conversely, exhibits both a longer correlation
+length and a long correlation time, results which we ascribe to the importance
+of spiral density waves within the flow. Consistent with prior results, we show
+that the mean local stress displays a well-defined correlation with the local
+vertical flux, and that this relation is apparently causal (in the sense of the
+flux stimulating the stress) during portions of a global dynamo cycle. We argue
+that the observed flux-stress relation supports dynamo models in which the
+structure of coronal magnetic fields plays a central role in determining the
+dynamics of thin-disk accretion.",1105.1789v1
+2012-10-24,Local outflows from turbulent accretion disks,"The aim of this paper is to investigate the properties of accretion disks
+threaded by a weak vertical magnetic field, with a particular focus on the
+interplay between MHD turbulence driven by the magnetorotational instability
+(MRI) and outflows that might be launched from the disk. For that purpose, we
+use a set of numerical simulations performed with the MHD code RAMSES in the
+framework of the shearing box model. We concentrate on the case of a rather
+weak vertical magnetic field such that the initial ratio beta0 of the thermal
+and magnetic pressures in the disk midplane equals 10^4. As reported recently,
+we find that MHD turbulence drives an efficient outflow out of the
+computational box. We demonstrate a strong sensitivity of that result to the
+box size: enlargements in the radial and vertical directions lead to a
+reduction of up to an order of magnitude in the mass-loss rate. Such a
+dependence prevents any realistic estimates of disk mass-loss rates being
+derived using shearing-box simulations. We find however that the flow
+morphology is robust and independent of the numerical details of the
+simulations. Its properties display some features and approximate invariants
+that are reminiscent of the Blandford & Payne launching mechanism, but
+differences exist. For the magnetic field strength considered in this paper, we
+also find that angular momentum transport is most likely dominated by MHD
+turbulence, the saturation of which scales with the magnetic Prandtl number,
+the ratio of viscosity and resistivity, in a way that is in good agreement with
+expectations based on unstratified simulations. This paper thus demonstrates
+for the first time that accretion disks can simultaneously exhibit MRI-driven
+MHD turbulence along with magneto-centrifugally accelerated outflows.",1210.6664v2
+2012-11-07,Ground States of Spin-1/2 Triangular Antiferromagnets in a Magnetic Field,"We use a combination of density matrix renormalization group calculations and
+analytical approaches to study a simplified model for a spatially anisotropic
+spin-1/2 triangular lattice Heisenberg antiferromagnet: the three-leg
+triangular spin tube (TST). The model is described by three Heisenberg chains,
+with exchange constant J, coupled antiferromagnetically with exchange constant
+J' along the diagonals of the ladder system, with periodic boundary conditions
+in the shorter direction. We determine the full phase diagram of this model as
+a function of spatial anisotropy, J'/J, and magnetic field. We find a rich
+phase diagram, which is dominated by quantum states - phases corresponding to
+the classical ground state appears only in a small region. Among the dominant
+phases generated by quantum effects are commensurate and incommensurate
+coplanar quasi-ordered states, which appear in the vicinity of the isotropic
+region for most fields, and in the high field region for most anisotropies. The
+coplanar states, while not classical ground states, can be understood
+semiclassically. Even more strikingly, the largest region of phase space is
+occupied by a spin density wave phase, which has incommensurate collinear
+correlations along the field. This phase has no semiclassical analog, and may
+be ascribed to enhanced one-dimensional (1d) fluctuations due to frustration.
+Cutting across the phase diagram is a magnetization plateau, with a gap to all
+excitations and up up down spin order, with a quantized magnetization equal to
+1/3 of the saturation value. In the TST, this plateau extends almost but not
+quite to the decoupled chains limit. Most of the above features are expected to
+carry over to the two dimensional system, which we also discuss. At low field,
+a dimerized phase appears, which is particular to the 1d nature of the TST, and
+which can be understood from quantum Berry phase arguments.",1211.1676v2
+2015-02-24,Temperature- and Field Dependent Characterization of a Twisted Stacked-Tape Cable,"The Twisted Stacked-Tape Cable (TSTC) is one of the major high temperature
+superconductor cable concepts combining scalability, ease of fabrication and
+high current density making it a possible candidate as conductor for large
+scale magnets. To simulate the boundary conditions of such a magnets as well as
+the temperature dependence of Twisted Stacked-Tape Cables a 1.16 m long sample
+consisting of 40, 4 mm wide SuperPower REBCO tapes is characterized using the
+""FBI"" (force - field - current) superconductor test facility of the Institute
+for Technical Physics (ITEP) of the Karlsruhe Institute of Technology (KIT). In
+a first step, the magnetic background field is cycled while measuring the
+current carrying capabilities to determine the impact of Lorentz forces on the
+TSTC sample performance. In the first field cycle, the critical current of the
+TSTC sample is tested up to 12 T. A significant Lorentz force of up to 65.6
+kN/m at the maximal magnetic background field of 12 T result in a 11.8 %
+irreversible degradation of the current carrying capabilities. The degradation
+saturates (critical cable current of 5.46 kA at 4.2 K and 12 T background
+field) and does not increase in following field cycles. In a second step, the
+sample is characterized at different background fields (4-12 T) and surface
+temperatures (4.2-37.8 K) utilizing the variable temperature insert of the
+""FBI"" test facility. In a third step, the performance along the length of the
+sample is determined at 77 K, self-field. A 15 % degradation is obtained for
+the central part of the sample which was within the high field region of the
+magnet during the in-field measurements.",1502.06728v1
+2015-07-31,"Vorticity, Shocks and Magnetic Fields in Subsonic, ICM-like Turbulence","We analyze high resolution simulations of compressible, MHD turbulence with
+properties resembling conditions in galaxy clusters. The flow is driven to
+turbulence Mach number $\mathcal{M}_t \sim 1/2$ in an isothermal medium with an
+initially very weak, uniform seed magnetic field ($\beta = P_g/P_B = 10^6$).
+Since cluster turbulence is likely to result from a mix of sheared (solenoidal)
+and compressive forcing processes, we examine the distinct turbulence
+properties for both cases. In one set of simulations velocity forcing is
+entirely solenoidal ($\nabla\cdot \delta {\vec u} = 0$), while in the other it
+is entirely compressive ($\nabla\times \delta {\vec u} = 0$). Both cases
+develop a mixture of solenoidal and compressive turbulent motions, since each
+generates the other. The development of compressive turbulent motions leads to
+shocks, even when the turbulence is solenoidally forced and subsonic. Shocks,
+in turn, produce and amplify vorticity, which is especially important in
+compressively forced turbulence. To clarify those processes we include a pair
+of appendices that look in detail at vorticity evolution in association with
+shocks. From our simulation analyses we find that magnetic fields amplified to
+near saturation levels in predominantly solenoidal turbulence can actually
+enhance vorticity on small scales by concentrating and stabilizing shear. The
+properties, evolution rates and relative contributions of the kinetic and
+magnetic turbulent elements depend strongly on the character of the forcing.
+Specifically, shocks are stronger, but vorticity evolution and magnetic field
+amplification are slower and weaker when the turbulence is compressively
+forced. We identify a simple relation to estimate characteristic shock
+strengths in terms of the turbulence Mach number and the character of the
+forcing. Our results will be helpful in understanding flow motions in galaxy
+clusters.",1507.08737v1
+2016-02-11,Supersaturation and activity-rotation relation in PMS stars: the young Cluster h Per,"The magnetic activity of late-type MS stars is characterized by different
+regimes, and their activity levels are well described by Ro, the ratio between
+P_rot and the convective turnover time. Very young PMS stars show, similarly to
+MS stars, intense magnetic activity. However they do not show clear
+activity-rotation trends, and it still debated which stellar parameters
+determine their magnetic activity levels. To bridge the gap between MS and PMS
+stars, we studied the activity-rotation relation in the young cluster h Per, a
+~13 Myr old cluster, that contains both fast and slow rotators, whose members
+have ended their accretion phase and have already developed a radiative core.
+It offers us the opportunity to study the activity level of intermediate-age
+PMS stars with different rotational velocities, excluding any interactions with
+the circumstellar environment. We constrained the magnetic activity levels of h
+Per members measuring their X-ray emission from a Chandra observation, while
+P_rot were obtained by Moraux et al. (2013). We collected a final catalog of
+414 h Per members with known P_rot, T_eff, M_star, with 169 of them having also
+detected X-ray emission. We found that h Per members, with 1.0 M_sun < M_star <
+1.4 M_sun, display different activity regimes: fast rotators show
+supersaturation, while slower rotators have activity levels compatible to the
+non-saturated regime. At 13 Myr h Per is therefore the youngest cluster showing
+activity-rotation regimes analogous to that of MS stars, indicating that, at
+this age, magnetic field production is likely regulated by the alpha-Omega type
+dynamo. Moreover we observed that supersaturation is better described by P_rot
+than Ro, and that the observed patterns are compatible with the hypothesis of
+centrifugal stripping. In this scenario we inferred that coronae can produce
+structures as large as ~2 R_star above the stellar surface.",1602.03696v2
+2016-04-28,Temperature evolution of magnetic structure of HoFeO$_3$ by single crystal neutron diffraction,"We have investigated the temperature evolution of the magnetic structures of
+HoFeO$_3$ by single crystal neutron diffraction. The three different magnetic
+structures found as a function of temperature for \hfo\ are described by the
+magnetic groups Pb$'$n$'2_1$, Pbn$2_1$ and Pbn$'2_1'$ and are stable in the
+temperature ranges $\approx$ 600-55~K, 55-37~K and 35$>T>2$~K respectively. In
+all three the fundamental coupling between the Fe sub-lattices remains the same
+and only their orientation and the degree of canting away from the ideal axial
+direction varies. The magnetic polarisation of the Ho sub-lattices in these two
+higher temperature regions, in which the major components of the Fe moment lie
+along $x$ and $y$, is very small. The canting of the moments from the axial
+directions is attributed to the antisymmetric interactions allowed by the
+crystal symmetry. They include contributions from single ion anisotropy as well
+as the Dzyaloshinski antisymmetric exchange. In the low temperature phase two
+further structural transitions are apparent in which the spontaneous
+magnetisation changes sign with respect to the underlying antiferromagnetic
+configuration. In this temperature range the antisymmetric exchange energy
+varies rapidly as the the Ho sub-lattices begin to order. So long as the
+ordered Ho moments are small the antisymmetric exchange is due only to Fe-Fe
+interactions, but as the degree of Ho order increases the Fe-Ho interactions
+take over whilst at the lowest temperatures, when the Ho moments approach
+saturation the Ho-Ho interactions dominate. The reversals of the spontaneous
+magnetisation found in this study suggest that in \hfo\ the sums of the Fe-Fe
+and Ho-Ho antisymmetric interactions have the same sign as one another, but
+that of the Ho-Fe terms is opposite.",1604.08349v1
+2017-08-18,Low mass planet migration in magnetically torqued dead zones - I. Static migration torque,"Motivated by models suggesting that the inner planet forming regions of
+protoplanetary discs are predominantly lacking in viscosity-inducing
+turbulence, and are possibly threaded by Hall-effect generated large-scale
+horizontal magnetic fields, we examine the dynamics of the corotation region of
+a low-mass planet in such an environment. The corotation torque in an inviscid,
+isothermal, dead zone ought to saturate, with the libration region becoming
+both symmetrical and of a uniform vortensity, leading to fast inward migration
+driven by the Lindblad torques alone. However, in such a low viscosity
+situation, the material on librating streamlines essentially preserves its
+vortensity. If there is relative radial motion between the disc gas and the
+planet, the librating streamlines will no longer be symmetrical. Hence, if the
+gas is torqued by a large scale magnetic field so that it undergoes a net
+inflow or outflow past the planet, driving evolution of the vortensity and
+inducing asymmetry of the corotation region, the corotation torque can grow,
+leading to a positive torque. In this paper we treat this effect by applying a
+symmetry argument to the previously studied case of a migrating planet in an
+inviscid disc. Our results show that the corotation torque due to a laminar
+Hall-induced magnetic field in a dead zone behaves quite differently from that
+studied previously for a viscous disc. Furthermore, the magnetic field induced
+corotation torque and the dynamical corotation torque in a low viscosity disc
+can be regarded as one unified effect.",1708.05721v2
+2018-08-01,"Rare earth size dependence on structural, electronic and magnetic properties of R2NiMnO6 double perovskites","Rare earth Manganite Nickelite double perovskites are prepared by solgel
+assisted combustion route, where, R varies from La, Pr, Nd, Sm, Gd, Tb, Dy, Y,
+and Ho. The samples have been systematically investigated using powder xray
+diffraction, Raman spectroscopy, ultraviolet visible spectroscopy,
+magnetization, and synchrotron based xray absorption spectroscopy measurements.
+All compounds in the family crystallize in the monoclinic structure and the
+monoclinic distortion enhances with decreasing trivalent rare earth radii. The
+magnetic ordering temperature, Tc, decreases from 270 K for La to 80 K for Ho
+samples as the rare earth radii decrease from 0.116nm for La to 0.102nm in case
+of Ho. An additional anomaly is observed in samples containing Nd, Sm, Tb, and
+Dy at lower temperatures, which originates from the 3d to 4f coupling between
+Mn and Ni and Nd, Sm, Tb and Dy magnetic moments. Further, high saturation
+magnetization is achieved for all samples indicating that they are atomically
+ordered and have less anti site disorders. Upon decreasing the size of rare
+earth ions, the local structure shows an expansion of NiO6 octahedra and almost
+unchanged MnO6 octahedra. Xray absorption near edge spectroscopy reveals that
+majority of Ni and Mn ions are in positive 2 and positive 4 valence states in
+all the samples. Raman spectra of RNMO show a softening of phonon modes
+resulting in the elongation of Ni to O and Mn to O bond lengths. Finally, a
+correlation between lattice parameters, structural distortion, octahedral
+tilting, superexchange angle, and electronic band gap, Curie temperature, and
+the rare earth ionic radius is established.",1808.00170v1
+2019-03-04,Noncontrast free-breathing respiratory self-navigated coronary artery cardiovascular magnetic resonance angiography at 3 T using lipid insensitive binomial off-resonant excitation (LIBRE),"Robust and homogeneous lipid suppression is mandatory for coronary magnetic
+resonance angiography (MRA) since coronary arteries are commonly embedded in
+fat. However, effective large volume lipid suppression becomes challenging when
+performing radial whole-heart coronary MRA and the problem may even be
+exacerbated at increasing magnetic field strengths. Incomplete fat suppression
+also generates artifacts, and may affect advanced motion correction methods.
+The aim was to evaluate a recently reported lipid insensitive MRI method for
+self-navigated coronary MRA at 3T. Lipid insensitive binomial off resonant
+excitation (LIBRE) radiofrequency (RF) excitation pulses were included into a
+self-navigated 3D radial GRE coronary MRA sequence at 3T. LIBRE was compared
+against conventional fat saturation (FS) and binomial 1-180{\deg}-1 water
+excitation (WE). First, fat suppression of all techniques was numerically
+characterized using Matlab and experimentally validated in phantoms and in legs
+of human volunteers. Subsequently, free-breathing self-navigated coronary MRA
+was performed using the LIBRE pulse as well as FS and WE in ten volunteers.
+Results obtained in the simulations were confirmed by the experimental
+validations as LIBRE enabled near complete fat suppression for 3D radial
+imaging in vitro and in vivo. For self-navigated whole-heart coronary MRA at
+3T, fat SNR was significantly attenuated using LIBRE compared with conventional
+FS. LIBRE increased the RCA vessel sharpness significantly (37 +/- 9% (LIBRE)
+vs. 29 +/- 8% (FS) and 30 +/- 8% (WE), both p<0.05) and led to a significant
+increase in the measured RCA vessel length to (83 +/- 31 mm (LIBRE) vs. 56 +/-
+12 mm (FS) and 59 +/- 27 (WE) p<0.05). LIBRE enables robust large volume fat
+suppression and significantly improves coronary artery image quality at 3T
+compared to the use of conventional fat suppression and water excitation.",1903.01325v2
+2019-10-01,"Oxygen deficiency and migration mediated electric polarization in Fe,Co-substituted SrTiO$_{3-δ}$","We use density functional theory (DFT) calculations to show that oxygen
+vacancies ($v_\mathrm{O}$) and mobility induce noncentrosymmetric polar
+structures in SrTi$_{1-x-y}$Fe$_{x}$Co$_{y}$O$_{3-\delta}$ ($x=y=0.125$) with
+$\delta = \{0.125, 0.25\}$, enhance the saturation magnetization and give rise
+to large changes in the electric polarization $\vert\Delta P\vert$. We present
+an intuitive set of rules for SrTiFeCoO$_{3-\delta}$ (STFC), which are based on
+the interplay between (Co/Fe)-$v_\mathrm{O}$ defects, magnetic cations
+coordination and topological vacancy disorder. STFC structures convey layered
+crystals with sheets of linear organized O$_{4,5,6}$-coordinated Fe-Co pairs,
+sandwiched with layers of O$_{5}$-coordinated Ti. Co,Fe-$v_\mathrm{O}$ defects
+are the source of the crystal distortions, cations off-centering and bending of
+the oxygen octahedra, which added to the charge redistribution mediated by
+$v_\mathrm{O}$, the cations electronegativity and valence states trigger an
+effective electric polarization. Oxygen migrations for $\delta=0.125$ provides
+us with $\vert\Delta \mathbf{P}\vert$ $>\sim10 \mu$C/cm$^2$ due to a
+quantum-of-polarization differences between $\delta=0.125$ structures.
+Increasing the deficiency to $\delta=0.25$ yields $\vert\Delta \mathbf{P}\vert$
+whose O-migration resolved polarization for $\delta=0.25$ is $>\sim3
+\mu$C/cm$^2$ in the worst case scenario. Magnetism is dominated by the Fe,Co
+spin states for $\delta=0.125$ while there is a raid of Ti magnetic moments
+($\sim1\mu_{B}$) for $\delta=0.25$. Magnetic and electric order parameters
+change for variations of $\delta$ or oxygen migrations for a given deficiency.
+Our results capture characteristics observed in the end-members of the series
+SrTi(Co,Fe)O$_{3}$, and suggest the existence of a broader set of rules for
+oxygen deficient multiferroic oxides.",1910.00176v2
+2020-07-25,Time-resolved fast turbulent dynamo in a laser plasma,"Understanding magnetic-field generation and amplification in turbulent plasma
+is essential to account for observations of magnetic fields in the universe. A
+theoretical framework attributing the origin and sustainment of these fields to
+the so-called fluctuation dynamo was recently validated by experiments on laser
+facilities in low-magnetic-Prandtl-number plasmas ($\mathrm{Pm} < 1$). However,
+the same framework proposes that the fluctuation dynamo should operate
+differently when $\mathrm{Pm} \gtrsim 1$, the regime relevant to many
+astrophysical environments such as the intracluster medium of galaxy clusters.
+This paper reports a new experiment that creates a laboratory $\mathrm{Pm}
+\gtrsim 1$ plasma dynamo for the first time. We provide a time-resolved
+characterization of the plasma's evolution, measuring temperatures, densities,
+flow velocities and magnetic fields, which allows us to explore various stages
+of the fluctuation dynamo's operation. The magnetic energy in structures with
+characteristic scales close to the driving scale of the stochastic motions is
+found to increase by almost three orders of magnitude from its initial value
+and saturate dynamically. It is shown that the growth of these fields occurs
+exponentially at a rate that is much greater than the turnover rate of the
+driving-scale stochastic motions. Our results point to the possibility that
+plasma turbulence produced by strong shear can generate fields more efficiently
+at the driving scale than anticipated by idealized MHD simulations of the
+nonhelical fluctuation dynamo; this finding could help explain the large-scale
+fields inferred from observations of astrophysical systems.",2007.12837v1
+2020-09-08,Disorder and magnetic field induced Bose-metal state in two-dimensional Ta$_x$(SiO$_2$)$_{1-x}$ granular films,"The origin of the intermediate anomalous metallic state in two-dimensional
+superconductor materials remains enigmatic. In the present paper, we observe
+such a state in a series of $\sim$9.0 nm thick Ta$_x$(SiO$_2$)$_{1-x}$ ($x$
+being the volume fraction of Ta) nanogranular films. At zero field, the $x$
+$\gtrsim$ 0.75 films undergo a Berezinskii-Kosterlitz-Thouless transition as
+transform from normal to superconducing states upon cooling. For the $x$
+$\lesssim$ 0.71 films, the resistance increases with decreasing temperature
+from 2 K down to 40 mK. A normal state to anomalous metallic state transition
+is observed in the $x$ $\simeq$ 0.73 film, i.e., near the transition
+temperature, the resistance of the film decreases sharply upon cooling as if
+the system would cross over to superconducting state, but then saturates to a
+value far less than that in normal state. When a small magnetic field
+perpendicular to the film plane is applied, the anomalous metallic state occurs
+in the $x$ $\gtrsim$ 0.75 films. It is found that both disorder and magnetic
+field can induce the transition from superconductor to anomalous metal and
+their influences on the transition are similar. For the the magnetic field
+induced case, we find the sheet resistance $R_{\square}(T,H)$ ($T$ and $H$
+being the temperature and the magnitude of magnetic field) data near the
+crossover from the anomalous metal to superconductor and in the vicinity of the
+anomalous metal to insulator transition, respectively, obey unique scaling laws
+deduced from the Bose-metal model. Our results strongly suggest that the
+anomalous metallic state in the Ta$_x$(SiO$_2$)$_{1-x}$ granular films is
+bosonic and dynamical gauge field fluctuation resulting from superconducting
+quantum fluctuations plays a key role in its formation.",2009.03511v1
+2020-09-17,Particle acceleration by relativistic magnetic reconnection driven by kink instability turbulence in Poynting flux dominated jets,"Particle acceleration in magnetized relativistic jets still puzzles
+theorists, specially when one tries to explain the highly variable emission
+observed in blazar jets or gamma-ray bursts putting severe constraints on
+current models. In this work we investigate the acceleration of particles
+injected in a three-dimensional relativistic magnetohydrodynamical jet subject
+to current driven kink instability (CDKI), which drives turbulence and fast
+magnetic reconnection. Test protons injected in the nearly stationary snapshots
+of the jet, experience an exponential acceleration up to a maximum energy. For
+a background magnetic field of $B \sim 0.1$ G, this saturation energy is $\sim
+10^{16}$ eV, while for $B \sim 10$ G it is $\sim 10^{18}$ eV. The simulations
+also reveal a clear association of the accelerated particles with the regions
+of fast reconnection. In the early stages of the development of the non-linear
+growth of CDKI in the jet, when there are still no sites of fast reconnection,
+injected particles are also efficiently accelerated, but by magnetic curvature
+drift in the wiggling jet spine. However, they have to be injected with an
+initial energy much larger than that required for particles to accelerate in
+reconnection sites. Finally, we have also obtained from the simulations an
+acceleration time due to reconnection with a weak dependence on the particles
+energy $E$, $t_A \propto E^{0.1}$. The energy spectrum of the accelerated
+particles develops a high energy tail with a power law index $p \sim$ -1.2 in
+the beginning of the acceleration, in agreement with earlier works. Our results
+provide an appropriate multi-dimensional framework for exploring this process
+in real systems and explain their complex emission patterns, specially in the
+very high energy bands and the associated neutrino emission recently detected
+in some blazars.",2009.08516v5
+2020-10-21,The impact of magnetic fields on momentum transport and saturation of shear-flow instability by stable modes,"The Kelvin-Helmholtz (KH) instability of a shear layer with an
+initially-uniform magnetic field in the direction of flow is studied in the
+framework of 2D incompressible magnetohydrodynamics with finite resistivity and
+viscosity using direct numerical simulations. The shear layer evolves freely,
+with no external forcing, and thus broadens in time as turbulent stresses
+transport momentum across it. As with KH-unstable flows in hydrodynamics, the
+instability here features a conjugate stable mode for every unstable mode in
+the absence of dissipation. Stable modes are shown to transport momentum up its
+gradient, shrinking the layer width whenever they exceed unstable modes in
+amplitude. In simulations with weak magnetic fields, the linear instability is
+minimally affected by the magnetic field, but enhanced small-scale fluctuations
+relative to the hydrodynamic case are observed. These enhanced fluctuations
+coincide with increased energy dissipation and faster layer broadening, with
+these features more pronounced in simulations with stronger fields. These
+trends result from the magnetic field reducing the effects of stable modes
+relative to the transfer of energy to small scales. As field strength
+increases, stable modes become less excited and thus transport less momentum
+against its gradient. Furthermore, the energy that would otherwise transfer
+back to the driving shear due to stable modes is instead allowed to cascade to
+small scales, where it is lost to dissipation. Approximations of the turbulent
+state in terms of a reduced set of modes are explored. While the Reynolds
+stress is well-described using just two modes per wavenumber at large scales,
+the Maxwell stress is not.",2010.11198v1
+2020-12-09,Pressure control of the magnetic anisotropy of the quasi-two-dimensional van der Waals ferromagnet Cr$_2$Ge$_2$Te$_6$,"We report the results of the pressure-dependent measurements of the static
+magnetization and of the ferromagnetic resonance (FMR) of Cr$_2$Ge$_2$Te$_6$ to
+address the properties of the ferromagnetic phase of this quasi-two-dimensional
+van der Waals magnet. The static magnetic data at hydrostatic pressures up to
+3.4 GPa reveal a gradual suppression of ferromagnetism in terms of a reduction
+of the critical transition temperature, a broadening of the transition width
+and an increase of the field necessary to fully saturate the magnetization
+$M_{\rm s}$. The value of $M_{\rm s} \simeq 3\mu_{\rm B}$/Cr remains constant
+within the error bars up to a pressure of 2.8 GPa. The anisotropy of the FMR
+signal continuously diminishes in the studied hydrostatic pressure range up to
+2.39 GPa suggesting a reduction of the easy-axis type magnetocrystalline
+anisotropy energy (MAE). A quantitative analysis of the FMR data gives evidence
+that up to this pressure the MAE constant $K_{\rm U}$, although getting
+significantly smaller, still remains finite and positive, i.e. of the easy-axis
+type. Therefore, a recently discussed possibility of switching the sign of the
+magnetocrystalline anisotropy in Cr$_2$Ge$_2$Te$_6$ could only be expected at
+still higher pressures, if possible at all due to the observed weakening of the
+ferromagnetism under pressure. This circumstance may be of relevance for the
+design of strain-engineered functional heterostructures containing layers of
+Cr$_2$Ge$_2$Te$_6$.",2012.05193v2
+2021-04-28,Structural transformation and magnetic properties of (Fe$_{0.7}$Co$_{0.3}$)$_2$B alloys doped with 5$d$ elements: A combined first-principles and experimental study,"(Fe,Co)$_2$B-based compounds with specified 5$d$ substitutions are considered
+as promising materials for permanent magnets without rare-earth elements. We
+conducted a combined first-principles and experimental study focused on
+(Fe$_{0.7}$Co$_{0.3}$)$_2$B alloys doped with W and Re. First, we used
+full-potential local-orbital scheme to systematically investigate (Fe,Co)$_2$B
+alloys with 3$d$, 4$d$, and 5$d$ substitutions. Computational analyses showed a
+significant increase in magnetocrystalline anisotropy only for the Re doped
+sample. Simultaneously, the structural and magnetic properties of the
+(Fe$_{0.7-x}$Co$_{0.3-x}$M$_{2x}$)$_2$B ($M$ = W, Re; $x$ = 0, 0.025) alloys
+were investigated experimentally. The desired (Fe,Co)$_2$B tetragonal phase was
+synthesized by heat treatment of amorphous precursors. We observed that
+isothermal annealing increases the coercive field of all samples. However, the
+obtained values, without further optimization, are well below the threshold for
+permanent magnet applications. Nevertheless, annealing of substituted samples
+at 750$^o$C significantly improves saturation magnetization values.
+Furthermore, M\""{o}ssbauer spectroscopy revealed a reduction of the hyperfine
+field due to the presence of Co atoms in the (Fe,Co)$_2$B phase, where
+additional defect positions are formed by Re and W. Radio-frequency
+M\""{o}ssbauer studies showed that (Fe$_{0.7}$Co$_{0.3}$)$_2$B and the
+W-substituted sample began to crystallize when exposed to an radio frequency
+field of 12 Oe, indicating that the amorphous phase is stabilized by Re
+substitution. Improvement of thermal stability of
+(Fe$_{0.675}$Co$_{0.275}$Re$_{0.05}$)$_2$B alloy is consistent with the results
+of differential scanning calorimetry and thermomagnetic measurements.",2104.13724v2
+2021-10-27,A Subgrid Turbulent Mean Field Dynamo Model for Cosmological Galaxy Formation Simulations,"Magnetic fields have been included in cosmological simulations of galaxy
+formation only recently, due to advances in numerical techniques and a better
+understanding of the galaxy formation physics. In this paper, we develop a new
+subgrid model for the turbulent dynamo that takes place in the supersonic
+interstellar medium in star-forming galaxies. It is based on a mean-field
+approach that computes the turbulent kinetic energy at unresolved scales (the
+so-called subgrid scales) and modifies the induction equation to account for
+the corresponding $\alpha$ dynamo. Our subgrid model depends on one free
+parameter, the quenching parameter, that controls the saturation of the subgrid
+dynamo. Thanks to this mean-field approach, we can now model the fast
+amplification of the magnetic field inside turbulent star-forming galaxies,
+without relying on artificially strong initial fields or without using
+prohibitively expensive high-resolution simulations. We show that the evolution
+of the magnetic field in our zoom-in Milky Way-like galaxy is consistent with a
+simple picture, in which the field is in equipartition with the turbulent
+kinetic energy inside the star-forming disc, with a field strength around 10
+$\mu$G at low redshift, while at the same time strong galactic outflows fill
+the halo with a slightly weaker magnetic field, whose strength (10 nG) is
+consistent will the ideal MHD dilution factor. Our results are in good
+agreement with recent theoretical and numerical predictions. We also compare
+our simulation with Faraday depth observations at both low and high redshift,
+seeing overall good agreement with some caveats. Our model naturally predicts
+stronger magnetic fields at high redshift (around 100 $\mu$G in the galaxy and
+1 $\mu$G in the halo), but also stronger depolarisation effects due to stronger
+turbulence at early time.",2110.14246v2
+2022-06-24,Exploring the disk-jet connection in NGC 315,"Aims. Hot accretion flows are thought to be able to power the relativistic
+jets observed in Active Galactic Nuclei. They can present themselves as SANE
+(Standard And Normal Evolution) disks or MAD (Magnetically Arrested Disks), two
+states implying profound differences in the physical properties of the disks
+themselves and of the outflows they produce. Methods. In this paper we use a
+multi-frequency and multi-epoch data set to study the giant radio galaxy NGC
+315, with the goal to explore the properties of its accretion disk and
+sub-parsec jet. We analyze the source maps with a pixel-based analysis and we
+use theoretical models to link the observational properties of the jet to the
+physical state of the accretion disk. Results. We propose that the bulk flow in
+NGC 315 accelerates on sub-pc scales, concurrently with the parabolic
+expansion. We show that this fast acceleration can be theoretically reconciled
+with a magnetically driven acceleration. Along the acceleration and collimation
+zone, we observe an unexpected spectral behavior, with very steep spectral
+index values $\alpha \sim -1.5$ ($S_\nu \propto \nu^\alpha$) between 22 GHz and
+43 GHz. Based on the properties of this region, we predict the black hole of
+NGC 315 to be fast rotating and the magnetic flux threading the accretion disk
+to be in excellent agreement with that expected in the case of a MAD. Using a
+new formalism based on the core-shift effect, we model the magnetic field
+downstream a quasi-parabolic accelerating jet and we reconstruct it up to the
+event horizon radius. In the MAD scenario, we compare it with the expected
+magnetic saturation strengths in the disk, finding a good agreement.",2206.12193v1
+2022-11-25,Two-band conduction as a pathway to non-linear Hall effect and unsaturated negative magnetoresistance in the martensitic compound GdPd2Bi,"The present work aims to address the electronic and magnetic properties of
+the intermetallic compound GdPd$_2$Bi through a comprehensive study of the
+structural, magnetic, electrical and thermal transport on a polycrystalline
+sample, followed by theoretical calculations. Our findings indicate that the
+magnetic ground state is antiferromagnetic in nature. Magnetotransport data
+present prominent hysteresis loop hinting a structural transition with further
+support from specific heat and thermopower measurements, but no such signature
+is observed in the magnetization study. Temperature dependent powder x-ray
+diffraction measurements confirm martensitic transition from the
+high-temperature (HT) cubic Heusler $L2_1$ structure to the low-temperature
+(LT) orthorhombic $Pmma$ structure similar to many previously reported shape
+memory alloys. The HT to LT phase transition is characterized by a sharp
+increase in resistivity associated with prominent thermal hysteresis. Further,
+we observe robust Bain distortion between cubic and orthorhombic lattice
+parameters related by $a_{orth} = \sqrt{2}a_{cub}$, $b_{orth} = a_{cub}$ and
+$c_{orth} = a_{cub}/\sqrt{2}$, that occurs by contraction along $c$-axis and
+elongation along $a$-axis respectively. The sample shows an unusual
+`non-saturating' $H^2$-dependent negative magnetoresistance for magnetic field
+as high as 150 kOe. In addition, non-linear field dependence of Hall
+resistivity is observed below about 30 K, which coincides with the sign change
+of the Seebeck coefficient. The electronic structure calculations confirm
+robust metallic states both in the LT and HT phases. It indicates complex
+nature of the Fermi surface along with the existence of both electron and hole
+charge carriers. The anomalous transport behaviors can be related to the
+presence of both electron and hole pockets.",2211.13982v1
+2023-04-05,Understanding the Relationship between Solar Coronal Abundances and F10.7 cm Radio Emission,"Sun-as-a-star coronal plasma composition, derived from full-Sun spectra, and
+the F10.7 radio flux (2.8 GHz) have been shown to be highly correlated (r =
+0.88) during solar cycle 24. However, this correlation becomes nonlinear during
+increased solar magnetic activity. Here, we use co-temporal, high spatial
+resolution, multi-wavelength images of the Sun to investigate the underlying
+causes of the non-linearity between coronal composition (FIP bias) and F10.7
+solar index correlation. Using the Karl G. Jansky Very Large Array (JVLA),
+Hinode/EIS (EUV Imaging Spectrometer), and the Solar Dynamic Observatory (SDO),
+we observed a small active region, AR 12759, throughout the solar atmosphere
+from the photosphere to the corona. Results of this study show that the
+magnetic field strength (flux density) in active regions plays an important
+role in the variability of coronal abundances, and it is likely the main
+contributing factor to this non-linearity during increased solar activity.
+Coronal abundances above cool sunspots are lower than in dispersed magnetic
+plage regions. Strong magnetic concentrations are associated with stronger
+F10.7 cm gyroresonance emission. Considering that as the solar cycle moves from
+minimum to maximum, the size of sunspots and their field strength increase with
+gyroresonance component, the distinctly different tendencies of radio emission
+and coronal abundances in the vicinity of sunspots is the likely cause of
+saturation of Sun-as-a-star coronal abundances during solar maximum, while the
+F10.7 index remains well correlated with the sunspot number and other magnetic
+field proxies.",2304.02552v1
+2023-09-29,Turbulent dynamo action and its effects on the mixing at the convective boundary of an idealized oxygen-burning shell,"Convection is one of the most important mixing processes in stellar
+interiors. Hydrodynamic mass entrainment can bring fresh fuel from neighboring
+stable layers into a convection zone, modifying the structure and evolution of
+the star. Under some conditions, strong magnetic fields can be sustained by the
+action of a turbulent dynamo, adding another layer of complexity and possibly
+altering the dynamics in the convection zone and at its boundaries. In this
+study, we used our fully compressible Seven-League Hydro code to run detailed
+and highly resolved three-dimensional magnetohydrodynamic simulations of
+turbulent convection, dynamo amplification, and convective boundary mixing in a
+simplified setup whose stratification is similar to that of an oxygen-burning
+shell in a star with an initial mass of $25\ M_\odot$. We find that the random
+stretching of magnetic field lines by fluid motions in the inertial range of
+the turbulent spectrum (i.e., a small-scale dynamo) naturally amplifies the
+seed field by several orders of magnitude in a few convective turnover
+timescales. During the subsequent saturated regime, the magnetic-to-kinetic
+energy ratio inside the convective shell reaches values as high as $0.33$, and
+the average magnetic field strength is ${\sim}10^{10}\,\mathrm{G}$. Such strong
+fields efficiently suppress shear instabilities, which feed the turbulent
+cascade of kinetic energy, on a wide range of spatial scales. The resulting
+convective flows are characterized by thread-like structures that extend over a
+large fraction of the convective shell. The reduced flow speeds and the
+presence of magnetic fields with strengths up to $60\%$ of the equipartition
+value at the upper convective boundary diminish the rate of mass entrainment
+from the stable layer by ${\approx}\,20\%$ as compared to the purely
+hydrodynamic case.",2309.17225v1
+2024-02-19,Magnetic anisotropy and GGG substrate stray field in YIG films down to millikelvin temperatures,"Quantum magnonics investigates the quantum-mechanical properties of magnons
+such as quantum coherence or entanglement for solid-state quantum information
+technologies at the nanoscale. The most promising material for quantum
+magnonics is the ferrimagnetic yttrium iron garnet (YIG), which hosts magnons
+with the longest lifetimes. YIG films of the highest quality are grown on a
+paramagnetic gadolinium gallium garnet (GGG) substrate. The literature has
+reported that ferromagnetic resonance (FMR) frequencies of YIG/GGG decrease at
+temperatures below 50 K despite the increase in YIG magnetization. We
+investigated a 97 nm-thick YIG film grown on 500 $\mathrm{\mu}$m-thick GGG
+substrate through a series of experiments conducted at temperatures as low as
+30 mK, and using both analytical and numerical methods. Our findings suggest
+that the primary factor contributing to the FMR frequency shift is the stray
+magnetic field created by the partially magnetized GGG substrate. This stray
+field is antiparallel to the applied external field and is highly
+inhomogeneous, reaching up to 40 mT in the center of the sample. At
+temperatures below 500 mK, the GGG field exhibits a saturation that cannot be
+described by the standard Brillouin function for a paramagnet. Including the
+calculated GGG field in the analysis of the FMR frequency versus temperature
+dependence allowed the determination of the cubic and uniaxial anisotropies. We
+find that the total anisotropy increases more than three times with the
+decrease in temperature down to 2 K. Our findings enable accurate predictions
+of the YIG/GGG magnetic systems behavior at low and ultra-low millikelvin
+temperatures, crucial for developing quantum magnonic devices.",2402.12112v1
+2024-02-22,Shubnikov-de Haas oscillations of biaxial-strain-tuned superconductors in pulsed magnetic field up to 60 T,"Two-dimensional (2D) materials have gained increasing prominence not only in
+fundamental research but also in daily applications. However, to fully harness
+their potential, it is crucial to optimize their properties with an external
+parameter and track the electronic structure simultaneously. Magnetotransport
+over a wide magnetic field range is a powerful method to probe the electronic
+structure and, for metallic 2D materials, quantum oscillations superimposed on
+the transport signals encode Fermi surface parameters. In this manuscript, we
+utilize biaxial strain as an external tuning parameter and investigate the
+effects of strain on the electronic properties of two quasi-2D superconductors,
+MoTe$_2$ and RbV$_3$Sb$_5$, by measuring their magnetoresistance in pulsed
+magnetic fields up to 60 T. With a careful selection of insulating substrates,
+we demonstrate the possibility of both the compressive and tensile biaxial
+strain, imposed on MoTe$_2$ and RbV$_3$Sb$_5$, respectively. For both systems,
+the applied strain has led to superconducting critical temperature enhancement
+compared to their free-standing counterparts, proving the effectiveness of this
+biaxial strain method at cryogenic temperatures. Clear quantum oscillations in
+the magnetoresistance -- the Shubnikov-de Haas (SdH) effect -- are obtained in
+both samples. In strained MoTe$_2$, the magnetoresistance exhibits a nearly
+quadratic dependence on the magnetic field and remains non-saturating even at
+the highest field. Whereas in strained RbV$_3$Sb$_5$, two SdH frequencies
+showed a substantial enhancement in effective mass values, hinting at a
+possible enhancement of charge fluctuations. Our results demonstrate that
+combining biaxial strain and pulsed magnetic field paves the way for studying
+2D materials under unprecedented conditions.",2402.14534v1
+2003-04-10,Ground Canonicity,"We explore how different proof orderings induce different notions of
+saturation. We relate completion, paramodulation, saturation, redundancy
+elimination, and rewrite system reduction to proof orderings.",0304017v1
+2004-12-14,Saturation in DIS at low x,"Saturation at low x appears as an almost unaboidable consequence of the
+two-gluon excange generic structure.",0412174v1
+2010-03-02,More (\ell_r) saturated (\mathcal{L}_\infty) spaces,"We present some new examples of separable (\mathcal_\infty) spaces which are
+(\ell_r) saturated for some (1 < r < \infty).",1003.0579v1
+2018-01-12,Graph cover-saturation,"Graph $G$ is $F$-saturated if $G$ contains no copy of graph $F$ but any edge
+added to $G$ produces at least one copy of $F$. One common variant of
+saturation is to remove the former restriction: $G$ is $F$-semi-saturated if
+any edge added to $G$ produces at least one new copy of $F$. In this paper we
+take this idea one step further. Rather than just allowing edges of $G$ to be
+in a copy of $F$, we require it: $G$ is $F$-covered if every edge of $G$ is in
+a copy of $F$. It turns out that there is smooth interaction between coverage
+and semi-saturation, which opens for investigation a natural analogue to
+saturation numbers. Therefore we present preliminary cover-saturation theory
+and structural bounds for the cover-saturation numbers of graphs. We also
+establish asymptotic cover-saturation densities for cliques and paths, and
+upper and lower bounds (with small gaps) for cycles and stars.",1801.04250v2
+2019-10-07,Investigating saturation effects in ultraperipheral collisions at the LHC with the color dipole model,"We investigate saturation effects in $ep$ scattering as well as in
+ultraperipheral $p$A and AA collisions at small $x$ with four variants of the
+impact parameter dependent color dipole model: with and without gluon
+saturation and with and without a novel mechanism that suppresses unphysical
+dipole radii above the confinement scale, a problem not addressed by most
+implementations. We show that $ep$ scattering at HERA can be very well
+described by any of the four variants. When going from $ep$ to $e$A scattering,
+saturation effects are expected to increase as $\sim$A$^{1/3}$. In lieu of an
+electron-ion collider, we confront the different versions of the dipole model
+with data recorded in ultraperipheral collisions at the LHC in order to
+estimate the sensitivity of the data to gluon saturation in the target nuclei.
+We find that ultraperipheral PbPb collisions indicate strong saturation effects
+while $p$Pb collisions turn out to not have any discriminating power to
+distinguish saturation from non-saturation scenarios.",1910.02899v2
+2021-07-27,Saturation of Rota's basis conjecture,"We prove an asymptotic saturation-type version of Rota's basis conjecture. It
+relies on the connection of Tao's slice rank with unstable tensors from
+geometric invariant theory.",2107.12926v1
+2023-01-02,On the saturation stress of deformed metals,"Crystalline materials exhibit an hysteresis behaviour when deformed
+cyclically. The origins of this tension-compression asymmetry have been fully
+understood only recently as being caused by an asymmetry in the junction
+strength and a reduced mean free path of dislocations inherited from previous
+deformation stage. Here, we investigate the saturation stress in fcc single-
+and poly-crystals using a Crystal Plasticity framework derived from dislocation
+dynamics simulations. In the absence of plastic localization and damage
+mechanism, the single-crystal mechanical response eventually saturates. We show
+that the cyclic saturation stress converges asymptotically to the monotonic
+saturation stress as the cycle plastic increment increases, and this
+convergence can be observed for some experimental conditions. The analysis of
+the experimental literature suggests that the mechanisms controlling the
+saturation in single crystals are the same controlling the cyclic response of
+polycrystals with large grains. We propose also analytical and approximated
+models to predict the saturation stress over the considered loading conditions.
+The saturation stress appears as a fundamental property of dislocations,
+explaining the consistency observed in the experimental literature. This work
+provides a unified view on the monotonous and cyclic responses of fcc single
+and poly-crystals, which may help in interpreting experimental data.",2301.00625v1
+2023-01-11,Pragmatic Estimation of Sample Size for Number of Interviews for PRO development in the 2009 FDA PRO guidance,"PROs developed de novo, using the FDA guidance may involve structured patient
+interviews or focus groups. Qualitative Research is a methodology for eliciting
+and coding interviews and produces concepts or themes. These concepts are used
+to develop items in a PRO for use as an endpoint in Clinical trials. A
+convention in the field is that interviews and code/concept elicitation are
+considered complete when subsequent interviews produces ""no new concepts""
+-termed ""saturation"". FDA reviewers frequently challenge PRO developers whether
+there are sufficient patient interviews to confirm that saturation is achieved
+after occurrence of zero new concepts. Several authors have reported that
+concrete criteria are need for confirming that saturation is achieved (Francis
+2010, Mason 2010, Marshall 2013). I provide statistical methodology for
+confirming saturation, suitable for review by a regulatory authority. Type I
+error for saturation, may occur if further interviews elicited more concepts
+after first occurrence of saturation. I use published data set on code
+elicitation (Guest, 2006) to demonstrate that saturation may occur more than
+once in a sequence of interviews. I provide a statistical definition for
+saturation in qualitative research, that addresses regulatory concerns for
+PRO's developed for use as a clinical trial endpoint in a regulatory
+submission.",2301.04760v1
+2024-02-01,Saturated ideals from Laver collapses,"Addressing a question of Shioya, we show that two-step iterations of the
+Laver collapse can force saturated ideals and Chang conjectures.",2402.00527v1
+1997-09-18,Supersaturation in X-ray emission of clusters stars,"A population of cool dwarfs with extreme rotational velocities (v sini > 100
+km/sec) is present in young open clusters. ROSAT observations have shown that
+these very fast rotators exhibit a level of X-ray activity a factor of 3-5
+below the saturated level which is usually observed (both in X-rays and other
+magnetic activity indicators) for `normally' fast rotators. This phenomenon has
+been denominated ""Supersaturation"". W UMa contact binaries seem to be
+supersaturated as well, while the scatter in the rotation-activity relation for
+RS CVn and BY Dra binaries does not allow us to clearly discern whether they
+exhibit supersaturation or not. Supersaturation is not seen in Halpha for Alpha
+Per supersaturated stars. Two alternative lines of interpretation are
+discussed.",9709177v1
+2001-10-20,Chandra Observations of High Mass Young Stellar Objects in the Monoceros R2 molecular cloud,"We observed the Monoceros R2 molecular cloud with the ACIS-I array onboard
+the Chandra X-ray Observatory. From the central 3.2' x 3.2' region, we detect
+154 sources above the detection limit of ~5x10^-16 ergs s^-1 cm^-2 with a 100
+ks-exposure. About 85% of the X-ray sources are identified with an infrared
+counterpart, including four high mass stars in zero age main sequence (ZAMS)
+and/or pre main sequence (PMS) phase. The X-ray spectra of the high mass ZAMS
+and PMS stars are represented with a thin thermal plasma model of a temperature
+above 2 keV. The X-rays are time-variable and exhibit rapid flares. These high
+temperature plasma and flaring activity are similar to those seen in low mass
+PMS stars and contrary to the behavior observed in high mass main sequence
+stars. The X-ray luminosity increases as the intrinsic K-band flux increases.
+However, the X-ray luminosity saturates at a level of ~10^31 ergs s^-1. We
+conclude that high mass ZAMS and PMS emit X-rays, possibly due to the magnetic
+activity like those of low mass stars.",0110462v1
+2001-11-29,Numerical study of the magnetorotational instability in weakly magnetised accretion disks: Resolution dependence of the Shakura-Sunyaev alpha,"In this letter, we present numerical calculations made to investigate the
+possible resolution dependence of the Shakura & Sunyaev (1973) viscosity
+parameter alpha from local magnetohydrodynamic simulations of the
+magnetorotational instability (MRI). We find that the values of alpha do indeed
+depend significantly on the numerical resolution but also that when the highest
+resolutions attainable by the computational resources available are used, the
+growth of the alpha-parameter seems to saturate. The values of alpha are at
+most of the order of 10^(-3), which indicates that the sole presence of
+turbulence due to dynamo generated magnetic field in the disk is not enough to
+reproduce alphas of the order unity which could explain some observational
+results (e.g. Cannizzo 1993).",0111554v1
+2004-01-15,Conference Summary: Three Dimensional Explosions,"This is the text of a summary of the workshop on asymmetric explosions held
+in Austin in June, 2003. A brief review is given of the author's own interests
+in dynamo theory as it may apply in the core collapse ambience. Of particular
+interest are saturation fields for the cases with central neutron stars and
+black holes and the possibility of driving MHD jets with the resulting fields.
+Interesting physics that may arise with large fields such as effects on the
+equation of state to produce anisotropic pressure and effects on neutrino cross
+sections and transport are briefly outlined. A brief summary of the
+contributions to the workshop is then given with special credit to Scratchy
+Serapkin. Of special note were the summaries of the advances due to
+spectropolarimetry in revealing the asymmetric nature of supernovae. Major
+progress in understanding the binary progenitors and explosion physics of Type
+Ia was presented. Other talks entwined the nature of asymmetric core collapse,
+gamma-ray bursts and ""hypernovae."" My final charge to the attendees was ""Go
+thee forth and think about rotation and magnetic fields!""",0401323v1
+2005-01-25,"A New Godunov Scheme for MHD, with Application to the MRI in disks","We describe a new numerical scheme for MHD which combines a higher order
+Godunov method (PPM) with Constrained Transport. The results from a selection
+of multidimensional test problems are presented. The complete test suite used
+to validate the method, as well as implementations of the algorithm in both F90
+and C, are available from the web. A fully three-dimensional version of the
+algorithm has been developed, and is being applied to a variety of
+astrophysical problems including the decay of supersonic MHD turbulence, the
+nonlinear evolution of the MHD Rayleigh-Taylor instability, and the saturation
+of the magnetorotational instability in the shearing box. Our new simulations
+of the MRI represent the first time that a higher-order Godunov scheme has been
+applied to this problem, providing a quantitative check on the accuracy of
+previous results computed with ZEUS; the latter are found to be reliable.",0501547v1
+2005-06-07,Self-Sustained Ionization and Vanishing Dead Zones in Protoplanetary Disks,"We analyze the ionization state of the magnetohydrodynamically turbulent
+protoplanetary disks and propose a new mechanism of sustaining ionization.
+First, we show that in the quasi-steady state of turbulence driven by
+magnetorotational instability in a typical protoplanetary disk with dust
+grains, the amount of energy dissipation should be sufficient for providing the
+ionization energy that is required for activating magnetorotational
+instability. Second, we show that in the disk with dust grains the energetic
+electrons that compose electric currents in weakly ionized gas can provide
+collisional ionization, depending on the actual saturation state of
+magnetorotational turbulence. On the other hand, we show that in the
+protoplanetary disks with the reduced effect of dust grains, the turbulent
+motion can homogenize the ionization degree, leading to the activation of
+magnetorotational instability even in the absence of other ionization
+processes. The results in this Letter indicate that most of the regions in
+protoplanetary disks remain magnetically active, and we thus require a change
+in the theoretical modeling of planet formation.",0506131v2
+2006-02-13,Properties of localized protons in neutron star matter for realistic nuclear models,"We study the localization of protons in the core of neutron stars for ten
+realistic nuclear models that share a common behaviour of nuclear symmetry
+energy which saturates and eventually decreases at high densities. This results
+in the low proton fraction of beta-stable neutron star matter. Protons form a
+small admixture in the neutron star core, which is localized at sufficiently
+high densities. For every model we calculate the density $n_{loc}$ above which
+the localization effect is present. Our results indicate that localization
+occurs at densities above $0.5-1.0 fm^{-3}$. The phase with localized protons
+occupies a spherical shell or a core region inside neutron stars which contains
+significant fraction of all nucleons. Proton localization is of great
+importance for astrophysical properties of neutron stars as it strongly affects
+transport coefficients of neutron star matter and can produce spontaneous
+magnetization in neutron stars.",0602281v1
+2006-02-15,Phase speed of electrostatic waves: The critical parameter for efficient electron surfing acceleration,"Particle acceleration by means of non-linear plasma wave interactions is of
+great topical interest. Accordingly, in this paper we focus on the electron
+surfing process. Self-consistent kinetic simulations, using both relativistic
+Vlasov and PIC (Particle In Cell) approaches, show here that electrons can be
+accelerated to highly relativistic energies (up to 100 m_e c^2) if the phase
+speed of the electrostatic wave is mildly relativistic (0.6c to 0.9c for the
+magnetic field strengths considered). The acceleration is strong because of
+relativistic stabilisation of the nonlinearly saturated electrostatic wave,
+seen in both relativistic Vlasov and PIC simulations. An inverse power law
+momentum distribution can arise for the most strongly accelerated electrons.
+These results are of relevance to observed rapid changes in the radio
+synchrotron emission intensities from microquasars, gamma ray bursts and other
+astrophysical objects that require rapid acceleration mechanisms for electrons.",0602337v1
+2006-08-17,A weakly nonlinear analysis of the magnetorotational instability in a model channel flow,"We show by means of a perturbative weakly nonlinear analysis that the
+axisymmetric magnetorotational instability (MRI) of a viscous, resistive,
+incompressible rotating shear flow in a thin channel gives rise to a real
+Ginzburg-Landau equation for the disturbance amplitude. For small magnetic
+Prandtl number (${\cal P}_{\rm m}$), the saturation amplitude is $\propto
+\sqrt{{\cal P}_{\rm m}}$ and the resulting momentum transport scales as ${\cal
+R}^{-1}$, where $\cal R$ is the {\em hydrodynamic} Reynolds number. Simplifying
+assumptions, such as linear shear base flow, mathematically expedient boundary
+conditions and continuous spectrum of the vertical linear modes, are used to
+facilitate this analysis. The asymptotic results are shown to comply with
+numerical calculations using a spectral code. They suggest that the transport
+due to the nonlinearly developed MRI may be very small in experimental setups
+with ${\cal P}_{\rm m} \ll 1$.",0608374v3
+2006-11-24,An in-depth study of the pre-polar candidate WX LMi,"Optical photometry, spectroscopy and XMM-Newton ultraviolet and X-ray
+observations with full phase coverage are used for an in-depth study of WXLMi,
+a system formerly termed as a low-accretion rate polar. We find a constant low
+mass accretion rate, M_dot ~ 1.5e-13 M_sun/yr, a peculiar accretion geometry
+with one spot not being accessible via Roche-lobe overflow, a low temperature
+of the white dwarf, Teff < 8000 K and the secondary likely being Roche-lobe
+underfilling. All this lends further support to the changed view on WXLMi and
+related systems as detached binaries, i.e. magnetic post-common envelope
+binaries without significant Roche-lobe overflow in the past. The transfer rate
+determined here is compatible with accretion from a stellar wind. We use
+cyclotron spectroscopy to determine the accretion geometry and to constrain the
+plasma temperatures. Both, cyclotron spectroscopy and X-ray plasma diagnostics
+reveal low plasma temperatures below 3 keV on both accretion spots. For the low
+m_dot, high B plasma at the accretion spots in WXLMi, cyclotron cooling is
+dominating thermal plasma radiation in the optical. Optical spectroscopy and
+X-ray timing reveal atmospheric, chromospheric and coronal activity at the
+saturation level on the dM4.5 secondary star.",0611758v1
+2006-12-20,Hardness-Intensity Correlations in Magnetar Afterglows,"We explore the hardness-intensity correlations observed in several AXPs and
+SGRs within the framework of a thermally emitting magnetar model. Using our
+detailed atmosphere models and taking into account reprocessing of the surface
+emission by the magnetosphere, we show that the hardness of the surface spectra
+increases with increasing temperature and hence the changes in the effective
+temperatures of the outer layers of the star alone can account for the observed
+correlations. We conclude that the slow release of the heat deposited in the
+deep crust during a magnetar burst naturally accounts for the spectral changes
+during the afterglow. The correlations are further enhanced by changes in the
+structures of the magnetic currents during or following a burst. However, the
+additional hardening produced by scattering of the surface photons off the
+magnetospheric charges saturates at moderate values of the scattering optical
+depth.",0612561v1
+1993-04-16,Conductance statistics in small insulating GaAs:Si wires at low temperature. II. Experimental study,"We have observed reproducible conductance fluctuations at low temperature in
+a small GaAs:Si wire driven across the Anderson transition by the application
+of a gate voltage. We analyse quantitatively the log-normal conductance
+statistics in terms of truncated quantum fluctuations. Quantum fluctuations due
+to small changes of the electron energy (controlled by the gate voltage) cannot
+develop fully due to identified geometrical fluctuations of the resistor
+network describing the hopping through the sample.
+  The evolution of the fluctuations versus electron energy and magnetic field
+shows that the fluctuations are non-ergodic, except in the critical insulating
+region of the Anderson transition, where the localization length is larger than
+the distance between Si impurities.
+  The mean magnetoconductance is in good accordance with simulations based on
+the Forward-Directed-Paths analysis, i.e. it saturates to $ {\rm ln} (\sigma
+(H>1)/\sigma (0))\simeq 1, $ as $ \sigma (0) $ decreases over orders of
+magnitude in the strongly localized regime.",9304029v1
+1995-12-13,Quantum transport in a multiwalled carbon nanotube,"We report on electrical resistance measurements of an individual carbon
+nanotube down to a temperature T=20 mK. The conductance exhibits a ln T
+dependence and saturates at low temperature. A magnetic field applied
+perpendicular to the tube axis, increases the conductance and produces
+aperiodic fluctuations. The data find a global and coherent interpretation in
+terms of two-dimensional weak localization and universal conductance
+fluctuations in mesoscopic conductors. The dimensionality of the electronic
+system is discussed in terms of the peculiar structure of carbon nanotubes.",9512106v2
+1997-05-26,Tunneling into Current-Carrying Surface States of High T$_c$ Superconductors,"Theoretical results for the ab-plane tunneling conductance in the d-wave
+model for high Tc superconductors are presented. The d-wave model predicts
+surface bound states below the maximum gap. A sub-dominant order parameter,
+stabilized by the surface, leads to a splitting of the zero-bias conductance
+peak (ZBCP) in zero external field and to spontaneous surface currents. In a
+magnetic field screening currents shift the quasiparticle bound state spectrum
+and lead to a voltage splitting of the ZBCP that is linear in H at low fields,
+and saturates at a pairbreaking critical field of order 3 Tesla. Comparisons
+with recent experimental results on Cu/YBCO junctions are presented.",9705260v1
+1997-07-16,New Far Infrared Vibrational Mode in Zn Doped CuGeO3,"We report on far infrared measurements on Zn and Si doped crystals of the
+spin-Peierls compound CuGeO3. Zn doping has the effect of introducing several
+new absorption lines, polarized in the ab-plane, between 5 and 55 cm-1. The
+intensity of the absorption grows with Zn concentration but saturates above 2%
+Zn. One line at 10 cm-1 loses intensity above 4K, and a second line at 20 cm-1
+is absent at low temperatures but grows to peak at about 40K in agreement with
+a three level model with two excited states 10 and 30 cm-1 above the ground
+state. As the doping is increased these lines broaden, and a temperature
+independent absorption developes over the entire range from 5 to 55 cm-1. These
+features are magnetic field independent up to 16T and are absent in Si doped
+samples. We suggest the new absorption is due to localized lattice modes of the
+zinc ion and the surrounding GeO4 tetrahedra.",9707163v1
+1999-07-10,Universal conductance fluctuations in three dimensional metallic single crystals of Si,"In this paper we report the measurement of conductance fluctuations in single
+crystals of Si made metallic by heavy doping (n \approx 2-2.5n_c, n_c being
+critical composition at Metal-Insulator transition). Since all dimensions (L)
+of the samples are much larger than the electron phase coherent length L_\phi
+(L/L_\phi \sim 10^3), our system is truly three dimensional. Temperature and
+magnetic field dependence of noise strongly indicate the universal conductance
+fluctuations (UCF) as predominant source of the observed magnitude of noise.
+Conductance fluctuations within a single phase coherent region of L_\phi^3 was
+found to be saturated at <(\delta G_\phi)^2> \approx (e^2/h)^2. An accurate
+knowledge of the level of disorder, enables us to calculate the change in
+conductance \delta G_1 due to movement of a single scatterer as \delta G_1 \sim
+e^2/h, which is \sim 2 orders of magnitude higher than its theoretically
+expected value in 3D systems.",9907158v2
+1999-08-13,Resistive upper critical fields and irreversibility lines of optimally-doped high-T_c cuprates,"We present the resistively-determined upper critical field H^{\rho}_{c2}(T)
+and the irreversibility lines H^{\rho}_{irr}(T) of various high-T_c cuprates,
+deduced from measurements in 61-T pulsed magnetic fields applied parallel to
+the c-axis. The SHAPE of both H^{\rho}_{c2}(T) and H^{\rho}_{irr}(T) depends
+monotonically on the anisotropy of the material and none of the samples show
+saturation of H^{\rho}(T) at low temperatures. The anomalous positive
+curvature, d^2 H^{\rho}/dT^2 > 0, is the strongest in materials with the
+largest normal-state anisotropy, regardless of whether anisotropy is varied by
+changing the carrier concentration or by comparing a variety of optimally-doped
+compounds.",9908190v1
+1999-12-10,High-Field Quasiparticle Tunneling in Bi_2Sr_2CaCu_2O_8+delta: Negative Magnetoresistance in the Superconducting State,"We report on the c-axis resistivity rho_c(H) in Bi_2Sr_2CaCu_2O_{8+\delta}
+that peaks in quasi-static magnetic fields up to 60 T. By suppressing the
+Josephson part of the two-channel (Cooper pair/quasiparticle) conductivity
+\sigma_c (H), we find that the negative slope of \rho_c(H) above the peak is
+due to quasiparticle tunneling conductivity \sigma_q(H) across the CuO_2 layers
+below H_{c2}. At high fields (a) \sigma_q(H) grows linearly with H, and (b)
+\rho_c(T) tends to saturate (sigma_c \neq 0) as T->0, consistent with the
+scattering at the nodes of the d-gap. A superlinear sigma_q(H) marks the normal
+state above T_c.",9912194v1
+2000-09-08,Ferromagnetism in the Two-Dimensional Periodic Anderson Model,"Using the constrained-path Monte Carlo method, we studied the magnetic
+properties of the two-dimensional periodic Anderson model for electron fillings
+between 1/4 and 1/2. We also derived two effective low energy theories to
+assist in interpreting the numerical results. For 1/4 filling we found that the
+system can be a Mott or a charge transfer insulator, depending on the relative
+values of the Coulomb interaction and the charge transfer gap between the two
+non-interacting bands. The insulator may be a paramagnet or antiferromagnet. We
+concentrated on the effect of electron doping on these insulating phases. Upon
+doping we obtained a partially saturated ferromagnetic phase for low
+concentrations of conduction electrons. If the system were a charge transfer
+insulator, we would find that the ferromagnetism is induced by the well-known
+RKKY interaction. However, we found a novel correlated hopping mechanism
+inducing the ferromagnetism in the region where the non-doped system is a Mott
+insulator. Our regions of ferromagnetism spanned a much smaller doping range
+than suggested by recent slave boson and dynamical mean field theory
+calculations, but they were consistent with that obtained by density matrix
+renormalization group calculations of the one-dimensional periodic Anderson
+model.",0009128v1
+2000-11-06,Quantum Hall Ferromagnetism in a Two-Dimensional Electron System,"Experiments on a nearly spin degenerate two-dimensional electron system
+reveals unusual hysteretic and relaxational transport in the fractional quantum
+Hall effect regime. The transition between the spin-polarized (with fill
+fraction $\nu = 1/3$) and spin-unpolarized ($\nu = 2/5$) states is accompanied
+by a complicated series of hysteresis loops reminiscent of a classical
+ferromagnet. In correlation with the hysteresis, magnetoresistance can either
+grow or decay logarithmically in time with remarkable persistence and does not
+saturate. In contrast to the established models of relaxation, the relaxation
+rate exhibits an anomalous divergence as temperature is reduced. These results
+indicate the presence of novel two-dimensional ferromagnetism with a
+complicated magnetic domain dynamic.",0011081v1
+2000-11-29,Level and Eigenfunction Statistics in Billiards with Surface Scattering,"Statistical properties of billiards with diffusive boundary scattering are
+investigated by means of the supersymmetric sigma-model in a formulation
+appropriate for chaotic ballistic systems. We study level statistics,
+parametric level statistics, and properties of electron wavefunctions. In the
+universal regime, our results reproduce conclusions of the random matrix
+theory, while beyond this regime we obtain a variety of system-specific results
+determined by the classical dynamics in the billiard. Most notably, we find
+that level correlations do not vanish at arbitrary separation between energy
+levels, or if measured at arbitrarily large difference of magnetic fields.
+Saturation of the level number variance indicates strong rigidity of the
+spectrum. To study spatial correlations of wavefunction amplitudes, we
+reanalyze and refine derivation of the ballistic version of the sigma-model.
+This allows us to obtain a proper matching of universal short-scale
+correlations with system-specific ones.",0011498v2
+2001-06-28,Field-Induced gap due to four-spin exchange in a spin ladder,"The effect of the four-spin cyclic exchange interaction at each plaquette in
+the $S=1/2$ two-leg spin ladder is investigated at T=0, especially focusing on
+the field-induced gap. The strong rung coupling approximation suggests that it
+yields a plateau at half of the saturation moment ($m=1/2$) in the
+magnetization curve, which corresponds to a field-induced spin gap with a
+spontaneous breaking of the translational symmetry. A precise phase diagram at
+$m=1/2$ is also presented based on the level spectroscopy analysis of the
+numerical data obtained by Lanczos method. The boundary between the gapless and
+plateau phases is confirmed to be of the Kosterlitz-Thouless (KT) universality
+class.",0106584v1
+2001-12-07,Proton Spin Relaxation Induced by Quantum Tunneling in Fe8 Molecular Nanomagnet,"The spin-lattice relaxation rate $T_{1}^{-1}$ and NMR spectra of $^1$H in
+single crystal molecular magnets of Fe8 have been measured down to 15 mK. The
+relaxation rate $T_1^{-1}$ shows a strong temperature dependence down to 400
+mK. The relaxation is well explained in terms of the thermal transition of the
+iron state between the discreet energy levels of the total spin S=10. The
+relaxation time $T_1$ becomes temperature independent below 300 mK and is
+longer than 100 s. In this temperature region stepwise recovery of the
+$^1$H-NMR signal after saturation was observed depending on the return field of
+the sweep field. This phenomenon is attributed to resonant quantum tunneling at
+the fields where levels cross and is discussed in terms of the Landau-Zener
+transition.",0112111v1
+2002-02-07,Ferromagnetism in the Kondo-lattice model,"We propose a modified RKKY-technique to evaluate the magnetic properties of
+the ferromagnetic Kondo-lattice model. Together with a previously developed
+selfenergy approach to the conduction electron part of the model we get a
+closed system of equations which can be solved self-consistently.
+Ferromagnetism appears for relatively low electron (hole) densities, while it
+is excluded around half-filling ($n=1$). For small $J$ conventional RKKY ($\sim
+J^2$) is reproduced; however, with strong deviations already for very moderate
+exchange couplings. For not too small $n$ a critical $J_c$ is needed to produce
+ferromagnetism with a finite Curie temperature $T_{\textrm{C}}$, which
+increases with $J$, then running into a kind of saturation, in order to fall
+off again and disappearing above an upper critical exchange $J$.",0202114v3
+2003-01-08,Kondo effect in underdoped n-type superconductors,"We present high-field magnetotransport properties of high-quality
+single-crystalline thin films of heavily underdoped nonsuperconducting
+(La,Ce)2CuO4, (Pr,Ce)2CuO4, and (Nd,Ce)2CuO4. All three materials show
+identical behavior. They are metallic at high temperatures and show an
+insulating upturn at low temperatures. The insulating upturn has a log T
+dependence, but saturates toward the lowest temperatures. Notably, the
+insulating upturn tends to be suppressed by applying magnetic fields. This
+negative magnetoresistance has a log B dependence, and its anisotropy shows non
+simple behavior. We discuss these findings from the viewpoints of Kondo
+scattering and also two-dimensional weak localization, and demonstrate Kondo
+scattering as a more plausible explanation. The Kondo scatters are identified
+as Cu2+ spins in the CuO2 planes.",0301090v1
+2003-02-12,Measurement of positive and negative scattering lengths in a Fermi gas of atoms,"An exotic superfluid phase has been predicted for an ultracold gas of
+fermionic atoms. This phase requires strong attractive interactions in the gas,
+or correspondingly atoms with a large, negative s-wave scattering length. Here
+we report on progress toward realizing this predicted superfluid phase. We
+present measurements of both large positive and large negative scattering
+lengths in a quantum degenerate Fermi gas of atoms. Starting with a
+two-component gas that has been evaporatively cooled to quantum degeneracy, we
+create controllable, strong interactions between the atoms using a
+magnetic-field Feshbach resonance. We then employ a novel rf spectroscopy
+technique to directly measure the mean-field interaction energy, which is
+proportional to the s-wave scattering length. Near the peak of the resonance we
+observe a saturation of the interaction energy; it is in this strongly
+interacting regime that superfluidity is predicted to occur. We have also
+observed anisotropic expansion of the gas, which has recently been suggested as
+a signature of superfluidity. However, we find that this can be attributed to a
+purely collisional effect.",0302246v1
+2003-03-12,Fundamental Curie temperature limit in ferromagnetic GaMnAs,"We provide experimental evidence that the upper limit of ~110 K commonly
+observed for the Curie temperature T_C of Ga(1-x)Mn(x)As is caused by the
+Fermi-level-induced hole saturation. Ion channeling, electrical and
+magnetization measurements on a series of Ga(1-x-y)Mn(x)Be(y)As layers show a
+dramatic increase of the concentration of Mn interstitials accompanied by a
+reduction of T_C with increasing Be concentration, while the free hole
+concentration remains relatively constant at ~5x10^20 cm^-3. These results
+indicate that the concentrations of free holes and ferromagnetically active Mn
+spins are governed by the position of the Fermi level, which controls the
+formation energy of compensating interstitial Mn donors.",0303217v1
+2003-04-29,Investigation of the Jahn-Teller Transition in TiF3 using Density Functional Theory,"We use first principles density functional theory to calculate electronic and
+magnetic properties of TiF3 using the full potential linearized augmented plane
+wave method. The LDA approximation predicts a fully saturated ferromagnetic
+metal and finds degenerate energy minima for high and low symmetry structures.
+The experimentally observed Jahn-Teller phase transition at Tc=370K can not be
+driven by the electron-phonon interaction alone, which is usually described
+accurately by LDA.
+  Electron correlations beyond LDA are essential to lift the degeneracy of the
+singly occupied Ti t2g orbital. Although the on-site Coulomb correlations are
+important, the direction of the t2g-level splitting is determined by the
+dipole-dipole interactions. The LDA+U functional predicts an aniferromagnetic
+insulator with an orbitally ordered ground state. The input parameters U=8.1 eV
+and J=0.9 eV for the Ti 3d orbital were found by varying the total charge on
+the TiF$_6^{2-}$ ion using the molecular NRLMOL code. We estimate the
+Heisenberg exchange constant for spin-1/2 on a cubic lattice to be
+approximately 24 K. The symmetry lowering energy in LDA+U is about 900 K per
+TiF3 formula unit.",0304667v2
+2003-05-29,Stripes and the (Cu)13-BEC model,"The (Cu)13-BEC model of high-temperature superconductivity was previously
+shown to account for many of the principal thermodynamic and electronic
+properties of the superconducting cuprates. Here I show that this model is also
+able to account for many of the key characteristics of the coupled CDW and SDW
+orders in these compounds. These include the general coexistence of metallic
+parallel stripes with superconductivity, the well-known linear relationship
+between the incommensurability of the SDW-induced IC magnetic peaks and the
+dopant concentration, as well as the saturation of this incommensurabilty at a
+value of about 1/8 for doping greater than 1/8. The model also provides a
+natural explanation for the celebrated 1/8-anomaly in LSCO and LBCO. It is also
+able to account for the severe suppression of the superconductivity in LNSCO at
+all doping levels and for the variations in the properties of LBSCO, at a fixed
+hole doping of 1/8, as its crystal structure is changed. Furthermore, the
+(Cu)13-BEC model is also consistent with many of the characteristics of the SDW
+orders in Y123. Most importantly, scanning tunneling microscopy results on
+Bi2212 appear to provide a direct validation of the CDW order predicted by the
+model.",0305672v1
+2003-07-01,Effect of two bands on critical fields in MgB2 thin films with various resistivity values,"Upper critical fields of four MgB2 thin films were measured up to 28 Tesla at
+Grenoble High Magnetic Field Laboratory. The films were grown by Pulsed Laser
+Deposition and showed critical temperatures ranging between 29.5 and 38.8 K and
+resistivities at 40 K varying from 5 to 50 mWcm. The critical fields in the
+perpendicular direction turned out to be in the 13-24 T range while they were
+estimated to be in 42-57 T the range in ab-planes. In contrast to the
+prediction of the BCS theory, we did not observe any saturation at low
+temperatures: a linear temperature dependence is exhibited even at lowest
+temperatures at which we made the measurements. Moreover, the critical field
+values seemed not to depend on the normal state resistivity value. In this
+paper, we analyze these data considering the multiband nature of
+superconductivity in MgB2 We will show how the scattering mechanisms that
+determine critical fields and resistivity can be different.",0307013v2
+2004-01-07,Large positive magneto-resistance in high mobility 2D electron gas : interplay of short and long range disorder,"We have observed a large positive quasi-classical magneto-resistance (MR) in
+a high mobility 2D electron gas in AlGaAs/GaAs heterostructure. The
+magneto-resistance is non-saturating and increases with magnetic field as
+$\rho_{xx}\sim B^{\alpha} (\alpha=0.9-1.2)$. In antidot lattices a
+non-monotonic MR is observed. We show that in both cases this MR can be
+qualitatively described in terms of the theory recently advanced by Polyakov et
+al (PRB, 64, 205306 (2001)). Their prediction is that such behavior as we
+observe may be the consequence of a concurrent existence of short and long
+range scattering potentials.",0401085v2
+2004-04-08,"""Spin-Flop"" Transition and Anisotropic Magnetoresistance in Pr_{1.3-x}La_{0.7}Ce_{x}CuO_{4}: Unexpectedly Strong Spin-Charge Coupling in Electron-Doped Cuprates","We use transport and neutron-scattering measurements to show that a
+magnetic-field-induced transition from noncollinear to collinear spin
+arrangement in adjacent CuO_{2} planes of lightly electron-doped
+Pr_{1.3-x}La_{0.7}Ce_{x}CuO_{4} (x=0.01) crystals affects significantly both
+the in-plane and out-of-plane resistivity. In the high-field collinear state,
+the magnetoresistance (MR) does not saturate, but exhibits an intriguing
+four-fold-symmetric angular dependence, oscillating from being positive at
+B//[100] to being negative at B//[110]. The observed MR of more than 30% at low
+temperatures induced by a modest modification of the spin structure indicates
+an unexpectedly strong spin-charge coupling in electron-doped cuprates.",0404196v1
+2004-04-30,Metal-Insulator-Like Behavior in Semimetallic Bismuth and Graphite,"When high quality bismuth or graphite crystals are placed in a magnetic field
+directed along the c-axis (trigonal axis for bismuth) and the temperature is
+lowered, the resistance increases as it does in an insulator but then
+saturates. We show that the combination of unusual features specific to
+semimetals, i.e., low carrier density, small effective mass, high purity, and
+an equal number of electrons and holes (compensation), gives rise to a unique
+ordering and spacing of three characteristic energy scales, which not only is
+specific to semimetals but which concomitantly provides a wide window for the
+observation of apparent field induced metal-insulator behavior. Using
+magnetotransport and Hall measurements, the details of this unusual behavior
+are captured with a conventional multi-band model, thus confirming the
+occupation by semimetals of a unique niche between conventional metals and
+semiconductors.",0404725v2
+2004-05-26,Vortex in Maxwell-Chern-Simons models coupled to external backgrounds,"We consider Maxwell-Chern-Simons models involving different non-minimal
+coupling terms to a non relativistic massive scalar and further coupled to an
+external uniform background charge. We study how these models can be
+constrained to support static radially symmetric vortex configurations
+saturating the lower bound for the energy. Models involving Zeeman-type
+coupling support such vortices provided the potential has a ""symmetry breaking""
+form and a relation between parameters holds. In models where minimal coupling
+is supplemented by magnetic and electric field dependant coupling terms, non
+trivial vortex configurations minimizing the energy occur only when a non
+linear potential is introduced. The corresponding vortices are studied
+numerically",0405605v1
+2004-07-02,Spin Polarization Dependence of the Coulomb Drag at Large $r_{s}$,"We find that the temperature dependence of the drag resistivity ($\rho_{D}$)
+between two dilute two-dimensional hole systems exhibits an unusual dependence
+upon spin polarization. Near the apparent metal-insulator transition, the
+temperature dependence of the drag, given by $T^{\alpha}$, weakens with the
+application of a parallel magnetic field ($B_{||}$), with $\alpha$ saturating
+at half its zero field value for $B_{||} > B^{*}$, where $B^{*}$ is the
+polarization field. Furthermore, we find that $\alpha$ is roughly 2 at the
+parallel field induced metal-insulator transition, and that the temperature
+dependence of $\rho_{D}/T^{2}$ at different $B_{||}$ looks strikingly similar
+to that found in the single layer resistivity. In contrast, at higher
+densities, far from the zero field transition, the temperature dependence of
+the drag is roughly independent of spin polarization, with $\alpha$ remaining
+close to 2, as expected from a simple Fermi liquid picture.",0407049v1
+2004-11-08,Hysteresis in an Ising model with mobile bonds,"Hysteresis is studied in a disordered Ising model in which diffusion of
+antiferromagnetic bonds is allowed in addition to spin flips. Saturation
+behavior changes to a figure-eight loop when diffusion is introduced. The upper
+and lower fields delimiting the figure-eight are determined by the Hamiltonian,
+while its surface and the crossing point depend on the temperature and details
+of the dynamics. The main avalanche is associated with the disappearance of
+hidden order. Some experimental observations of figure-eight anomalies are
+discussed. It is argued they are a signal of a transient rearrangement of
+domain couplings, characteristic of amorphous and/or magnetically soft samples,
+and similar to evolution of kinetic glasses.",0411187v1
+2004-11-12,Hysteresis and avalanches in the T=0 random-field Ising model with 2-spin-flip dynamics,"We study the non-equilibrium behavior of the three-dimensional Gaussian
+random-field Ising model at T=0 in the presence of a uniform external field
+using a 2-spin-flip dynamics. The deterministic, history-dependent evolution of
+the system is compared with the one obtained with the standard 1-spin-flip
+dynamics used in previous studies of the model. The change in the dynamics
+yields a significant suppression of coercivity, but the distribution of
+avalanches (in number and size) stays remarkably similar, except for the
+largest ones that are responsible for the jump in the saturation magnetization
+curve at low disorder in the thermodynamic limit. By performing a finite-size
+scaling study, we find strong evidence that the change in the dynamics does not
+modify the universality class of the disorder-induced phase transition.",0411330v1
+2005-04-21,"Quantitative analysis of proximity effect in $Nb/Co_{60}Fe_{40}$, Nb/Ni, and $Nb/Cu_{40}Ni_{60}$ bilayers","We have studied the behavior of the superconducting critical temperature Tc
+in $Nb/Co_{60}Fe_{40}$, Nb/Ni, and $Nb/Cu_{40}Ni_{60}$ bilayers as a function
+of the thickness of each ferromagnetic metal layer. The Tc s of three sets of
+bilayers exhibit non-monotonic behavior as a function of each ferromagnetic
+metal thickness. Employing the quantitative analysis based on Usadel formalism
+of the effect of the exchange energy, we observed that the Tc behavior of
+$Nb/Co_{60}Fe_{40}$ bilayers is in good agreement with the theoretical values
+over the entire range of the data. On the other hand, the Tc s of Nb/Ni and
+$Nb/Cu_{40}Ni_{60}$ bilayers show a higher value in the small thickness regime
+than the theoretical prediction obtained from the calculation, which matches
+the dip position and the saturation value of Tc in the large thickness limit.
+This discrepancy is probably due to the weakened magnetic properties of Ni and
+$Cu_{40}Ni_{60}$ when they are thin. We discuss the values of our fitting
+parameters and its implication on the validity of the current Usadel formalism
+of the effect of the exchange energy.",0504543v1
+2005-05-02,"Influence of annealing parameters on the ferromagnetic properties of optimally passivated (Ga,Mn)As epilayers","The influence of annealing parameters - temperature and time - on the
+magnetic properties of As-capped (Ga,Mn)As epitaxial thin films have been
+investigated. The dependence of the transition temperature (Tc) on annealing
+time marks out two regions. The Tc peak behavior, characteristic of the first
+region, is more pronounced for thick samples, while for the second
+(`saturated') region the effect of the annealing time is more pronounced for
+thin samples. A right choice of the passivation medium, growth conditions along
+with optimal annealing parameters routinely yield Tc-values of ~ 150 K and
+above, regardless of the thickness of the epilayers.",0505040v1
+2005-06-03,Singlet-triplet decoherence due to nuclear spins in a double quantum dot,"We have evaluated hyperfine-induced electron spin dynamics for two electrons
+confined to a double quantum dot. Our quantum solution accounts for decay of a
+singlet-triplet correlator even in the presence of a fully static nuclear spin
+system, with no ensemble averaging over initial conditions. In contrast to an
+earlier semiclassical calculation, which neglects the exchange interaction, we
+find that the singlet-triplet correlator shows a long-time saturation value
+that differs from 1/2, even in the presence of a strong magnetic field.
+Furthermore, we find that the form of the long-time decay undergoes a
+transition from a rapid Gaussian to a slow power law ($\sim 1/t^{3/2}$) when
+the exchange interaction becomes nonzero and the singlet-triplet correlator
+acquires a phase shift given by a universal (parameter independent) value of
+$3\pi/4$ at long times. The oscillation frequency and time-dependent phase
+shift of the singlet-triplet correlator can be used to perform a precision
+measurement of the exchange interaction and Overhauser field fluctuations in an
+experimentally accessible system. We also address the effect of orbital
+dephasing on singlet-triplet decoherence, and find that there is an optimal
+operating point where orbital dephasing becomes negligible.",0506090v1
+2005-06-15,Sign change of the Grueneisen parameter and magnetocaloric effect near quantum critical points,"We consider the Grueneisen parameter and the magnetocaloric effect near a
+pressure and magnetic field controlled quantum critical point, respectively.
+Generically, the Grueneisen parameter (and the thermal expansion) displays a
+characteristic sign change close to the quantum-critical point signaling an
+accumulation of entropy. If the quantum critical point is the endpoint of a
+line of finite temperature phase transitions, T_c \propto (p_c-p)^Psi, then we
+obtain for p<p_c, (1) a characteristic increase \Gamma \sim T^{-1/(\nu z)} of
+the Grueneisen parameter Gamma for T>T_c, (2) a sign change in the Ginzburg
+regime of the classical transition, (3) possibly a peak at T_c, (4) a second
+increase Gamma \sim -T^{-1/(nu z)} below T_c for systems above the upper
+critical dimension and (5) a saturation of Gamma \propto 1/(p_c-p). We argue
+that due to the characteristic divergencies and sign changes the thermal
+expansion, the Grueneisen parameter and magnetocaloric effect are excellent
+tools to detect and identify putative quantum critical points.",0506336v2
+2005-06-27,Ferromagnetism of the Hubbard Model at Strong Coupling in the Hartree-Fock Approximation,"As a contribution to the study of Hartree-Fock theory we prove rigorously
+that the Hartree-Fock approximation to the ground state of the d-dimensional
+Hubbard model leads to saturated ferromagnetism when the particle density (more
+precisely, the chemical potential mu) is small and the coupling constant U is
+large, but finite. This ferromagnetism contradicts the known fact that there is
+no magnetization at low density, for any U, and thus shows that HF theory is
+wrong in this case. As in the usual Hartree-Fock theory we restrict attention
+to Slater determinants that are eigenvectors of the z-component of the total
+spin, {S}_z = sum_x n_{x,\uparrow} - n_{x,\downarrow}, and we find that the
+choice 2{S}_z = N = particle number gives the lowest energy at fixed 0 < mu <
+4d.",0506695v2
+2006-01-09,Muon-spin-rotation measurements of the penetration depth in Li_2Pd_3B,"Measurements of the magnetic field penetration depth $\lambda$ in the ternary
+boride superconductor Li$_2$Pd$_3$B ($T_c\simeq7.3$ K) have been carried out by
+means of muon-spin rotation ($\mu$SR). The absolute values of $\lambda$, the
+Ginzburg-Landau parameter $\kappa$, and the first $H_{c1}$ and the second
+$H_{c2}$ critical fields at T=0 obtained from $\mu$SR were found to be
+$\lambda(0)=252(2)$ nm, $\kappa(0)=27(1)$, $\mu_0H_{c1}(0)=9.5(1)$ mT, and
+$\mu_0H_{c2}(0)=3.66(8)$ T, respectively. The zero-temperature value of the
+superconducting gap $\Delta_0=$1.31(3) meV was found, corresponding to the
+ratio $2\Delta_0/k_BT_c=4.0(1)$. At low temperatures $\lambda(T)$ saturates and
+becomes constant below $T\simeq 0.2T_c$, in agreement with what is expected for
+s-wave BCS superconductors. Our results suggest that Li$_2$Pd$_3$B is a s-wave
+BCS superconductor with the only one isotropic energy gap.",0601156v2
+2006-04-28,Linear independence of localized magnon states,"At the magnetic saturation field, certain frustrated lattices have a class of
+states known as ""localized multi-magnon states"" as exact ground states. The
+number of these states scales exponentially with the number $N$ of spins and
+hence they have a finite entropy also in the thermodynamic limit $N\to \infty$
+provided they are sufficiently linearly independent. In this article we present
+rigorous results concerning the linear dependence or independence of localized
+magnon states and investigate special examples. For large classes of spin
+lattices including what we called the orthogonal type and the isolated type as
+well as the kagom\'{e}, the checkerboard and the star lattice we have proven
+linear independence of all localized multi-magnon states. On the other hand the
+pyrochlore lattice provides an example of a spin lattice having localized
+multi-magnon states with considerable linear dependence.",0604649v1
+2006-04-29,Electron and boson clusters in confined geometries: symmetry breaking in quantum dots and harmonic traps,"We discuss the formation of crystalline electron clusters in semiconductor
+quantum dots and of crystalline patterns of neutral bosons in harmonic traps.
+In a first example, we use calculations for two electrons in an elliptic
+quantum dot to show that the electrons can localize and form a molecular dimer.
+The calculated singlet-triplet splitting (J) as a function of the magnetic
+field (B) agrees with cotunneling measurements, with its behavior reflecting
+the effective dissociation of the dimer for large B. Knowledge of the dot shape
+and of J(B) allows determination of the degree of entanglement. In a second
+example, we study strongly repelling neutral bosons in two-dimensional harmonic
+traps. Going beyond the Gross-Pitaevskii (GP) mean-field approximation, we show
+that bosons can localize and form polygonal-ring-like crystalline patterns. The
+total energy of the crystalline phase saturates in contrast to the GP solution,
+and its spatial extent becomes smaller than that of the GP condensate.",0605012v1
+2006-05-17,Noninvasive measurements of gas exchange in a three-dimensional fluidized bed using hyperpolarized 129Xe NMR,"We present a novel NMR technique that provides a non-invasive, direct
+measurement of gas exchange in a three-dimensional gas-fluidized bed of solid
+particles. The NMR spectrum of hyperpolarized 129Xe gas in an Al2O3 particle
+bed displays three resolved peaks corresponding to xenon in bubbles, the
+interstitial spaces (emulsion), and adsorbed on particles. Modified NMR
+exchange and saturation-recovery sequences, together with data analysis based
+on an exchange-coupled set of Bloch equations, yield gas exchange rate
+constants between the emulsion and adsorbed phases, and between the bubble and
+emulsion phases. The results are in approximate agreement previously unverified
+predictions from well-known models of fluidized bed behavior. Incorporation of
+NMR imaging methodologies would straightforwardly allow similar measurements on
+a spatially-resolved basis.",0605436v1
+2006-06-18,In-plane hole density in Ca(0.1)La(0.9)Ba(1.65)La(0.35)Cu(3)O(y) ; nuclear resonance study over the full doping range,"We report in-plane Cu(63) Nuclear Magnetic Resonance measurements for a
+series of fully enriched Ca(0.1)La(0.9)Ba(1.65)La(0.35)Cu(3)O(y) powder
+samples, which belong to the YBCO family, but the doping could vary from very
+underdoped to extremely overdoped. From these measurements we determine the
+average nuclear quadrupole resonance frequency \nu_Q, and its second moment
+\Delta(\nu_Q), both set by the in-plane hole density, n, as a function of
+oxygen level, y. We find that in the overdoped side n is saturated, but
+\Delta(\nu_Q) rapidly increases with increasing y. The relevance of these
+results to the increasing penetration depth in overdoped cuprates is discussed.",0606475v1
+2006-10-23,Dynamical polarization of graphene at finite doping,"The polarization of graphene is calculated exactly within the random phase
+approximation for arbitrary frequency, wave vector, and doping. At finite
+doping, the static susceptibility saturates to a constant value for low
+momenta. At $q=2 k_{F}$ it has a discontinuity only in the second derivative.
+In the presence of a charged impurity this results in Friedel oscillations
+which decay with the same power law as the Thomas Fermi contribution, the
+latter being always dominant. The spin density oscillations in the presence of
+a magnetic impurity are also calculated. The dynamical polarization for low $q$
+and arbitrary $\omega $ is employed to calculate the dispersion relation and
+the decay rate of plasmons and acoustic phonons as a function of doping. The
+low screening of graphene, combined with the absence of a gap, leads to a
+significant stiffening of the longitudinal acoustic lattice vibrations.",0610630v2
+2006-12-19,Magnetothermal transport in the spin-1/2 chains of copper pyrazine dinitrate,"We present experiments on the thermal transport in the spin-1/2 chain
+compound copper pyrazine dinitrate Cu(C_4 H_4 N_2)(NO_3)_2. The heat
+conductivity shows a surprisingly strong dependence on the applied magnetic
+field B, characterized at low temperatures by two main features. The first one
+appearing at low B is a characteristic dip located at mu_B B ~ k_B T, that may
+arise from Umklapp scattering. The second one is a plateau-like feature in the
+quantum critical regime, mu_B |B-B_c| < k_B T, where B_c is the saturation
+field at T=0. The latter feature clearly points towards a momentum and field
+independent mean free path of the spin excitations, contrary to theoretical
+expectations.",0612486v2
+2007-01-01,Exact Thermodynamics of Pairing and Charge-spin Separation Crossovers in Small Hubbard Nanoclusters,"The exact numerical diagonalization and thermodynamics in an ensemble of
+small Hubbard clusters in the ground state and finite temperatures reveal
+intriguing insights into the nascent charge and spin pairings, Bose
+condensation and ferromagnetism in nanoclusters. The phase diagram off half
+filling strongly suggests the existence of subsequent transitions from electron
+pairing into unsaturated and saturated ferromagnetic Mott-Hubbard like
+insulators, driven by electron repulsion. Rigorous criteria for the existence
+of quantum critical points in the ground state and corresponding crossovers at
+finite temperatures are formulated. The phase diagram for 2x4-site clusters
+illustrates how these features are scaled with cluster size. The phase
+separation and electron pairing, monitored by a magnetic field and electron
+doping, surprisingly resemble phase diagrams in the family of doped high Tc
+cuprates.",0701022v1
+2001-02-28,Implications of the r-mode instability of rotating relativistic stars,"Several recent surprises appear dramatically to have improved the likelihood
+that the spin of rapidly rotating, newly formed neutron stars (and, possibly,
+of old stars spun up by accretion) is limited by a nonaxisymmetric instability
+driven by gravitational waves. Except for the earliest part of the spin-down,
+the axial l=m=2 mode (an r-mode) dominates the instability, and the emitted
+waves may be observable by detectors with the sensitivity of LIGO II. A review
+of these hopeful results is followed by a discussion of constraints on the
+instability set by dissipative mechanisms, including viscosity, nonlinear
+saturation, and energy loss to a magnetic field driven by differential
+rotation.",0102114v2
+1995-04-06,Static Quantities of the W bosons in the MSSM,"I discuss the static quantities of the W boson, magnetic dipole and electric
+quadrupole moments, in the context of the minimal supersymmetric standard
+model, in which supersymmetry is broken by soft terms $A_o,\, m_o,\, M_{1/2}$.
+Following a renormalization group analysis it is found that the supersymmetric
+values of $\Delta k_{\gamma}$ and $\Delta Q_{\gamma}$ can be largely different,
+in some cases, from the standard model predictions but of the same order of
+magnitude for values of \quad $A_0,m_0,M_{1/2} \leq {\cal O}(1 TeV) $.
+Therefore possible supersymmetric structure can be probed provided the accuracy
+of measurements for $\Delta k_{\gamma}$, $\Delta Q_{\gamma}$ reaches
+$10^{-2}-10^{-3}$ and hence hard to be detected at LEP2. In cases where
+$M_{1/2} \ll A_0,m_0 $, the charginos and neutralinos may give substantial
+contributions saturating the LEP2 sensitivity limits. This occurs when their
+masses $m_{\tilde C},m_{\tilde Z}$ turn out to be both light satisfying
+$m_{\tilde C}+m_{\tilde Z} \simeq M_W $. However these extreme cases are
+perturbatively untrustworthy and besides unnatural for they occupy a small
+region in the parameter space.",9504240v1
+2000-06-15,Deconfining by Winding: The Magnetic Monopole Vacua at High Temperatures,"Characterizing the vacuum of a thermalized SU(3) Yang-Mills theory in the
+dual Ginzburg-Landau description, the possibility of topologically nontrivial,
+classical monopole fields in the deconfining phase is explored. These fields
+are assumed to be Bogomoln'yi-Prasad-Sommerfield (BPS) saturated solutions
+along the compact, euclidean time dimension. A corresponding, gauge invariant
+monopole interaction is constructed. The model passes first tests. In
+particular, a reasonable value for the critical temperature is obtained, and
+the partial persistence of nonperturbative features in the deconfining phase of
+SU(3) Yang-Mills theory, as it is measured on the lattice, follows naturally.",0006163v3
+2001-04-19,Deconfining by Winding,"A model for the quantum effective description of the vacuum structure of
+thermalized SU(3) Yang-Mills theory is proposed. The model is based on Abelian
+projection leading to a Ginzburg-Landau theory for the magnetic sector. The
+possibility of topologically non-trivial, effective monopole fields in the
+deconfining phase is explored. These fields are assumed to be
+Bogomol'nyi-Prasad-Sommerfield saturated solutions along the compact, euclidean
+time dimension. Accordingly, a gauge invariant interaction for the monopole
+fields is constructed.
+  Motivated by the corresponding lattice results the vacuum dynamics is assumed
+to be dominated by the monopole fields. A reasonable value for the critical
+temperature is obtained, and the partial persistence of non-perturbative
+features in the deconfining phase of SU(3) Yang-Mills theory, as it is measured
+on the lattice, follows naturally.",0104188v2
+2005-05-02,VA\tilde V correlator within the instanton vacuum model,"The correlator of vector and nonsinglet axial-vector currents in the external
+electromagnetic field is calculated within the instanton liquid model of QCD
+vacuum. In general the correlator has two Lorentz structures: longitudinal w_L
+and transversal w_T with respect to axial-vector index. Within the instanton
+model the saturation of the anomalous w_L structure is demonstrated. It is
+known that in the chiral limit the transversal structure w_T is free from
+perturbative corrections. In this limit within the instanton model we calculate
+the transversal invariant function w_T at arbitrary momentum transfer, q, and
+show the absence of power corrections to this structure at large q^2. Instead
+there arise the exponential corrections to w_T at large q^2 reflecting nonlocal
+properties of QCD vacuum. The slope of w_T at zero virtuality, the QCD vacuum
+magnetic susceptibility of the quark condensate and its momentum dependence are
+estimated.",0505007v2
+2006-02-23,Implication of the B -> rho rho data on the B -> pi pi puzzle,"We point out that the B -> rho rho data have seriously constrained the
+possibility of resolving the B -> pi pi puzzle from the large observed B^0 ->
+pi^0 pi^0 branching ratio in the available theoretical approaches. The
+next-to-leading-order (NLO) contributions from the vertex corrections, the
+quark loops, and the magnetic penguin evaluated in the perturbative QCD (PQCD)
+approach have saturated the experimental upper bound of the B^0 -> rho^0 rho^0
+branching ratio, and do not help. The NLO PQCD predictions for the B^0 ->
+rho^\mp rho^\pm and B^\pm -> rho^\pm rho^0 branching ratios are consistent with
+the data. The inclusion of the NLO jet function from the soft-collinear
+effective theory into the QCD-improved factorization approach, though enhancing
+the B^0 -> pi^0 pi^0 branching ratio sufficiently, overshoots the bound of the
+B^0 -> rho^0 rho^0 branching ratio, and deteriorates the predictions for the
+B^\pm -> pi^0 K^\pm and B^0 -> pi^\mp K^\pm direct CP asymmetries.",0602214v3
+2006-05-05,Upper Bound on the Hadronic Light-by-Light Contribution to the Muon g-2,"There are indications that hadronic loops in some electroweak observables are
+almost saturated by parton level effects. Taking this as the hypothesis for
+this work, we propose a genuine parton level estimate of the hadronic
+light-by-light contribution to the anomalous magnetic moment of the muon, a_mu
+(LBL,had). Our quark mass definitions and values are motivated in detail, and
+the simplicity of our approach allows for a transparent error estimate. For
+infinitely heavy quarks our treatment is exact, while for asymptotically small
+quark masses a_mu (LBL,had) is overestimated. Interpolating, this suggests
+quoting an upper bound. We obtain a_mu (LBL,had) < 1.59 10^-9 (95% CL).",0605052v2
+1993-03-10,"Magnetic Monopoles, Bogomol'nyi Bound and SL(2,Z) Invariance in String Theory","We show that in heterotic string theory compactified on a six dimensional
+torus, the lower bound (Bogomol'nyi bound) on the dyon mass is invariant under
+the SL(2,Z) transformation that interchanges strong and weak coupling limits of
+the theory. Elementary string excitations are also shown to satisfy this lower
+bound. Finally, we identify specific monopole solutions that are related via
+the strong-weak coupling duality transformation to some of the elementary
+particles saturating the Bogomol'nyi bound, and these monopoles are shown to
+have the same mass and degeneracy of states as the corresponding elementary
+particles.",9303057v2
+1995-01-12,SEMILOCAL NONTOPOLOGICAL SOLITONS IN A CHERN-SIMONS THEORY.,"We show the existence of self-dual semilocal nontopological vortices in a
+$\Phi^2$ Chern-Simons (C-S) theory. The model of scalar and gauge fields with a
+$SU(2)_{global} \times U(1)_{local}$ symmetry includes both the C-S term and an
+anomalous magnetic contribution. It is demonstrated here, that the vortices are
+stable or unstable according to whether the vector topological mass $\kappa$ is
+less than or greater than the mass $m$ of the scalar field. At the boundary,
+$\kappa = m$, there is a two-parameter family of solutions all saturating the
+self-dual limit. The vortex solutions continuously interpolates between a ring
+shaped structure and a flux tube configuration.",9501041v1
+1995-12-20,Dyonic Black Hole in Heterotic String Theory,"We study some features of dyonic Black hole solution in heterotic string
+theory on a six torus. This solution has 58 parameters. Of these, 28 parameters
+denote the electric charge of the black hole, another 28 correspond to the
+magnetic charge, and the other two parameters being the mass and the angular
+momentum of the black hole. We discuss the extremal limit and show that in
+various limits, it reduces to the known black hole solutions. The solutions
+saturating the Bogomolnyi bound are identified. Explicit solution is presented
+for the non-rotating dyonic black hole.",9512157v3
+1996-02-01,Extreme dyonic black holes in string theory,"Supersymmetric extreme dyonic black holes of toroidally compactified
+heterotic or type II string theory can be viewed as lower-dimensional images of
+solitonic strings wound around a compact dimension. We consider conformal sigma
+models which describe string configurations corresponding to various extreme
+dyonic black holes in four and five dimensions. These conformal models have
+regular short-distance region equivalent to a WZW theory with level
+proportional to magnetic charges. Arguments are presented suggesting a
+universal relation between the black hole entropy (area) and the statistical
+entropy of BPS-saturated oscillation states of solitonic string.[Extended
+version of a talk at the Workshop ""Frontiers in Quantum Field Theory"", in honor
+of the 60th birthday of K. Kikkawa (Osaka, Japan, 14-17 December 1995)]",9601177v4
+1996-10-18,On the weak coupling spectrum of N=2 supersymmetric SU(n) gauge theory,"The weak coupling spectrum of BPS saturated states of pure $N=2$
+supersymmetric SU$(n)$ gauge theory is investigated. The method uses known
+results on the dyon spectrum of the analogous theory with $N=4$ supersymmetry,
+along with the action on these states of the semi-classical monodromy
+transformations. For dyons whose magnetic charge is not a simple root of the
+Lie algebra, it is found that the weak coupling region is divided into a series
+of domains, for which the dyons have different electric charge, separated by
+walls on which the dyons decay. The proposed spectrum is shown to be consistent
+with the exact solution of the theory at strong coupling in the sense that the
+states at weak coupling can account for the singularities at strong coupling.",9610142v1
+1997-01-26,Solitons in 1+1 Dimensional Gauged Sigma Models,"We study soliton solutions in 1+1 dimensional gauged sigma models, obtained
+by dimensional reduction from its 2+1 dimensional counterparts. We show that
+the Bogomol'nyi bound of these models can be expressed in terms of two
+conserved charges in a similar way to that of the BPS dyons in 3+1 dimensions.
+Purely magnetic vortices of the 2+1 dimensional completely gauged sigma model
+appear as charged solitons in the corresponding 1+1 dimensional theory. The
+scale invariance of these solitons is also broken because of the dimensional
+reduction. We obtain exact static soliton solutions of these models saturating
+the Bogomol'nyi bound.",9701132v2
+1997-08-27,Brane Dynamics From the Born-Infeld Action,"We use the abelian Born-Infeld action for the worldvolume gauge field and
+transverse displacement scalars to explore new aspects of D-brane structure and
+dynamics. We study several classic gauge field configurations, including point
+charges in any worldvolume dimension and vortices in two worldvolume
+dimensions, and show that, with an appropriate excitation of the transverse
+coordinate field, they are BPS-saturated solutions. The Coulomb point charge
+solutions turn out to represent, with considerable fidelity, fundamental
+strings attached to the brane (their magnetic counterparts describe D1-branes
+attached to D3-branes). We also show that S-matrix for small excitations
+propagating on the point charge solution is consistent with (and gives further
+illuminating information about) Polchinski's effective open string boundary
+condition.",9708147v3
+1999-06-02,Super 0-brane and GS Superstring Actions on AdS_2 \times S^2,"The super 0-brane and GS superstring actions on AdS$_2 \times S^2$ background
+with 2-form flux are constructed by supercoset approach. We find the super
+0-brane action contains two parameters which are interpreted as the electric
+and magnetic charges of the super 0-brane. The obtained super 0-brane action
+describes the BPS saturated dyonic superparticle moving on AdS$_2 \times S^2$
+background. The WZ action contains the required coupling with 2-form flux. For
+GS superstring, we find the string action on AdS$_2 \times S^2$ takes the same
+form as those in AdS$_3 \times S^3$ and AdS$_5 \times S^5$ with RR field
+background.",9906013v2
+2000-08-28,Exact Solutions of Multi-Vortices and False Vacuum Bubbles in Noncommutative Abelian-Higgs Theories,"We consider the noncommutative Abelian-Higgs theory and construct new types
+of exact multi-vortex solutions that solve the static equations of motion. They
+in general do not follow from the BPS equations; only for some specific values
+of parameters, they satisfy the BPS equations saturating the Bogomol'nyi bound.
+We further consider the Abelian-Higgs theory with more complicated scalar
+potential allowing unstable minima and construct exact solutions of
+noncommutative false vacuum bubble with integer magnetic flux. The classical
+stability of the solutions is discussed.",0008204v4
+2003-10-13,"S-Duality, Deconstruction and Confinement for a Marginal Deformation of N=4 SUSY Yang-Mills","We study an exactly marginal deformation of N=4 SUSY Yang-Mills with gauge
+group U(N) using field theory and string theory methods. The classical theory
+has a Higgs branch for rational values of the deformation parameter. We argue
+that the quantum theory also has an S-dual confining branch which cannot be
+seen classically. The low-energy effective theory on these branches is a
+six-dimensional non-commutative gauge theory with sixteen supercharges.
+Confinement of magnetic and electric charges, on the Higgs and confining
+branches respectively, occurs due to the formation of BPS-saturated strings in
+the low energy theory. The results also suggest a new way of deconstructing
+Little String Theory as a large-N limit of a confining gauge theory in four
+dimensions.",0310117v2
+2004-08-31,Non-Abelian Vortices in N=1* Gauge Theory,"We consider the N=1* supersymmetric SU(2) gauge theory and demonstrate that
+the Z_2 vortices in this theory acquire orientational zero modes, associated
+with the rotation of magnetic flux inside SU(2) group, and turn into the
+non-Abelian strings, when the masses of all chiral fields become equal. These
+non-Abelian strings are not BPS-saturated. We study the effective theory on the
+string world sheet and show that it is given by two-dimensional
+non-supersymmetric O(3) sigma model. The confined 't Hooft-Polyakov monopole is
+seen as a junction of the Z_2-string and anti-string, and as a kink in the
+effective world sheet sigma model. We calculate its mass and show that besides
+the four-dimensional confinement of monopoles, they are also confined in the
+two-dimensional theory: the monopoles stick to anti-monopoles to form the
+meson-like configurations on the strings they are attached to.",0408235v2
+2006-11-02,Integrable Vortex Dynamics in Anisotropic Planar Spin Liquid Model,"The problem of magnetic vortex dynamics in an anisotropic spin liquid model
+is considered. For incompressible flow the model admits reduction to saturating
+Bogomolny inequality analytic projections of spin variables, subject the linear
+holomorphic Schr\""odinger equation. It allows us to construct N vortex
+configurations in terms of the complex Hermite polynomials. Using complex
+Galilean boost transformations, the interaction of the vortices and the vortex
+chain lattices (vortex crystals) are studied. By the complexified Cole-Hopf
+transformation, integrable N vortex dynamics is described by the holomorphic
+Burgers equation. Mapping of the point vortex problem to N-particle problem,
+the complexified Calogero-Moser system, showing its integrability and the
+Hamiltonian structure, is given.",0611002v1
+2005-08-19,Quarks and Antiquarks in Nuclei,"The Chiral Quark-Soliton model provides the quark and antiquark substructure
+of the nucleon, which is embedded in nuclear matter. This provides a new way to
+asses the effects of the nuclear medium on the nucleon. We calculate nuclear
+binding and saturation, describe the European Muon Collaboration (EMC) effect
+consistently with Drell-Yan experiments, and predict modifications to the
+polarized parton distributions. We also calculate the electromagnetic form
+factors of a bound proton, and find significant modifications of the
+electromagnetic form factors in the nuclear environment. In every case, the
+properties of the sea of quark-antiquark pairs in the nucleon are very
+important, and serve to mitigate the valence quark effect. The changes in the
+sea quarks when the nucleon is immersed in the nuclear medium are the primary
+mode by which consistency is maintained with experimental constraints
+(Drell-Yan data, magnetic moment), while still maintaining a significant effect
+needed to explain the deep inelastic scattering and polarization transfer data.",0508036v1
+2001-03-26,An Atom Faucet,"We have constructed and modeled a simple and efficient source of slow atoms.
+  From a background vapour loaded magneto-optical trap, a thin laser beam
+extracts a continuous jet of cold rubidium atoms. In this setup, the extraction
+column that is typical to leaking MOT systems is created without any optical
+parts placed inside the vacuum chamber. For detailed analysis, we present a
+simple 3D numerical simulation of the atomic motion in the presence of multiple
+saturating laser fields combined with an inhomogeneous magnetic field. At a
+pressure of $P_{\rm Rb87}=1 \times 10^{-8}$ mbar, the moderate laser power of
+10 mW per beam generates a jet of flux $\Phi =1.3\times 10^8$ atoms/s with a
+mean velocity of 14 m/s and a divergence of $<20$ mrad.",0103085v1
+2002-06-03,An equilibrium model for RFP plasmas in the presence of resonant tearing modes,"The equilibrium of a finite-beta RFP plasma in the presence of
+saturated-amplitude tearing modes is investigated. The singularities of the MHD
+force balance equation JXB=grad(p) at the modes rational surfaces are resolved
+through a proper regularization of the zeroth-order (equilibrium) profiles, by
+setting to zero there the gradient of the pressure and parallel current
+density. An equilibrium model, which satisfies the regularization rule at the
+various rational surfaces, is developed. The comparison with the experimental
+data from the Reversed Field eXperiment (RFX) gives encouraging results. The
+model provides an easy tool for magnetic analysis: many aspects of the
+perturbations can be analyzed and reconstructed.",0206006v3
+2005-11-14,Nonlinear evolution of the m=1 internal kink mode in the presence of magnetohydrodynamic turbulence,"The nonlinear evolution of the m=1 internal kink mode is studied numerically
+in a setting where the tokamak core plasma is surrounded by a turbulent region
+with low magnetic shear. As a starting point we choose configurations with
+three nearby q=1 surfaces where triple tearing modes (TTMs) with high poloidal
+mode numbers m are unstable. While the amplitudes are still small, the fast
+growing high-m TTMs enhance the growth of the m=1 instability. This is
+interpreted as a fast sawtooth trigger mechanism. The TTMs lead to a partial
+collapse, leaving behind a turbulent belt with q ~= 1 around the unreconnected
+core plasma. Although, full reconnection can occur if the core displacement
+grows large enough, it is shown that the turbulence may actively prevent
+further reconnection. This is qualitatively similar to experimentally observed
+partial sawtooth crashes with post-cursor oscillations due to a saturated
+internal kink.",0511126v2
+2003-12-19,"Galilean Satellites as Sites for Incipient Life, and the Earth as its Shelter","Numerous problems connected with an assumption of the life origin on the
+Earth do not arise on Galilean satellites. Here, in presence of a practically
+non-salt water and of a great deal (~5-10%) of abiogenic organics, a great
+diversity of conditions, which are unthinkable for the Earth, were realized
+more than once. They were caused by global electrochemical processes in the
+magnetic field presence what could entail an absolute enantiomeric synthesis.
+The subsequent explosions of the satellites' icy envelopes saturated by the
+electrolysis products resulted in appearance of hot massive atmospheres and
+warm deep oceans and ejection of the dirty ice fragments (=comet nuclei), what
+led to the material exchange with other bodies, etc.",0312031v2
+2001-07-02,Comparative study of the transient evolution of Hanle EIT/EIA resonances,"The temporal evolutions of coherent resonances corresponding to
+electromagnetically induced transparency (EIT) and absorption (EIA) were
+observed in a Hanle absorption experiment carried on the $D_{2}$ lines of $%
+^{87}$Rb vapor by suddenly turning the magnetic field on or off. The main
+features of the experimental observations are well reproduced by a theoretical
+model based on Bloch equation where the atomic level degeneracy has been fully
+accounted for. Similar (opposite phase) evolutions were observed at low optical
+field intensities for Hanle/EIT or Hanle/EIA resonances. Unlike the Hanle/EIA\
+transients which are increasingly shorter for driving field intensities
+approaching saturation, the $B\neq 0$ transient of the Hanle/EIT signal at
+large driving field intensities present a long decay time approaching the
+atomic transit time. Such counterintuitive behavior is interpreted as a
+consequence of the Zeno effect.",0107007v1
+2007-04-14,Terahertz Time-Domain Magnetospectroscopy of a High-Mobility Two-Dimensional Electron Gas,"We have observed cyclotron resonance in a high-mobility GaAs/AlGaAs
+two-dimensional electron gas by using the techniques of terahertz time-domain
+spectroscopy combined with magnetic fields. From this, we calculate the real
+and imaginary parts of the diagonal elements of the magnetoconductivity tensor,
+which in turn allows us to extract the concentration, effective mass, and
+scattering time of the electrons in the sample. We demonstrate the utility of
+ultrafast terahertz spectroscopy, which can recover the true linewidth of
+cyclotron resonance in a high-mobility ($>{10}^{6} \mathrm{cm^{2} V^{-1}
+s^{-1}}$) sample without being affected by the saturation effect.",0704.1883v1
+2007-06-11,Absence of long-range Ni/Mn ordering in ferromagnetic La2NiMnO6 thin films,"Epitaxial La2NiMnO6 thin films have been grown on (001)-oriented SrTiO3 using
+the PLD technique. The thin films are semiconducting and FM with a TC close to
+270K, a coercive field of 920Oe, and a saturation magnetization of 5muB per
+f.u. TEM, conducted at RT, reveals a majority phase having ""I-centered""
+structure with a=c=1.4asub and b=2asub along with a minority phase-domains
+having ""P-type"" structure (asub being the lattice parameter of the perovskite
+structure). A discusion on the presence of Ni/Mn long-range ordering, in light
+of recent literature on double perovskites La2NiMnO6 is presented.",0706.1414v1
+2007-06-25,Calorimetric Evidence for a Fulde-Ferrell-Larkin-Ovchinnikov Superconducting State in the Layered Organic Superconductor κ$-(BEDT-TTF)$_2$Cu(NCS)$_2$,"The specific heat of the layered organic superconductor $\kappa$-%
+(BEDT-TTF)$_2$Cu(NCS)$_2$, where BEDT-TTF is bisethylenedithio-%
+tetrathiafulvalene, has been studied in magnetic fields up to 28 T applied
+perpendicular and parallel to the superconducting layers. In parallel fields
+above 21 T, the superconducting transition becomes first order, which signals
+that the Pauli-limiting field is reached. Instead of saturating at this field
+value, the upper critical field increases sharply and a second first-order
+transition line appears within the superconducting phase. Our results give
+strong evidence that the phase, which separates the homogeneous superconducting
+state from the normal state is a realization of a
+Fulde-Ferrell-Larkin-Ovchinnikov state.",0706.3584v2
+2007-07-24,Quantisation of Hopping Magnetoresistance Prefactor in Strongly Correlated Two-Dimensional Electron Systems,"We report an universal behaviour of hopping transport in strongly interacting
+mesoscopic two-dimensional electron systems (2DES). In a certain window of
+background disorder, the resistivity at low perpendicular magnetic fields
+follows the expected relation $\rho(B_\perp) = \rho_{\rm{B}}\exp(\alpha
+B_\perp^2)$. The prefactor $\rho_{\rm{B}}$ decreases exponentially with
+increasing electron density but saturates to a finite value at higher
+densities. Strikingly, this value is found to be universal when expressed in
+terms of absolute resistance and and shows quantisation at $R_{\rm{B}}\approx
+h/e^2$ and $R_{\rm{B}}\approx 1/2$ $ h/e^2$. We suggest a strongly correlated
+electronic phase as a possible explanation.",0707.3543v2
+2007-08-07,Spin-exchange relaxation free magnetometry with Cs vapor,"We describe a Cs atomic magnetometer operating in the spin-exchange
+relaxation-free (SERF) regime. With a vapor cell temperature of
+$103^\circ\rm{C}$ we achieve intrinsic magnetic resonance widths $\Delta B=17
+{\rm \mu G}$ corresponding to an electron spin-relaxation rate of $300 {\rm
+s^{-1}}$ when the spin-exchange rate is $\Gamma_{SE}=14000 {\rm s^{-1}}$. We
+also observe an interesting narrowing effect due to diffusion. Signal-to-noise
+measurements yield a sensitivity of about $400\thinspace{\rm pG/\sqrt{Hz}}$.
+Based on photon shot noise, we project a sensitivity of $40 {\rm
+pG/\sqrt{Hz}}$. A theoretical optimization of the magnetometer indicates
+sensitivities on the order of $2 {\rm pG/\sqrt{Hz}}$ should be achievable in a
+$1 {\rm cm^3}$ volume. Because Cs has a higher saturated vapor pressure than
+other alkali metals, SERF magnetometers using Cs atoms are particularly
+attractive in applications requiring lower temperatures.",0708.1012v1
+2007-08-16,On the possibility of a bimodal solar dynamo,"A simple way to couple an interface dynamo model to a fast tachocline model
+is presented, under the assumption that the dynamo saturation is due to a
+quadratic process and that the effect of finite shear layer thickness on the
+dynamo wave frequency is analoguous to the effect of finite water depth on
+surface gravity waves. The model contains one free parameter which is fixed by
+the requirement that a solution should reproduce the helioseismically
+determined thickness of the tachocline. In this case it is found that, in
+addition to this solution, another steady solution exists, characterized by a
+four times thicker tachocline and 4-5 times weaker magnetic fields. It is
+tempting to relate the existence of this second solution to the occurrence of
+grand minima in solar activity.",0708.2131v1
+2007-10-04,A Three Dimensional Kasteleyn Transition: Spin Ice in a [100] Field,"We examine the statistical mechanics of spin-ice materials with a [100]
+magnetic field. We show that the approach to saturated magnetisation is, in the
+low-temperature limit, an example of a 3D Kasteleyn transition, which is
+topological in the sense that magnetisation is changed only by excitations that
+span the entire system. We study the transition analytically and using a Monte
+Carlo cluster algorithm, and compare our results with recent data from
+experiments on Dy2Ti2O7.",0710.0976v3
+2007-10-25,Nucleon Form Factors and Hidden Symmetry in Holographic QCD,"The vector dominance of the electromagnetic form factors both for mesons and
+baryons arises naturally in holographic QCD, where both the number of colors
+and the 't Hooft coupling are taken to be very large, offering a bona-fide
+derivation of the notion of vector dominance. The crucial ingredient for this
+is the infinite tower of vector mesons in the approximations made which share
+features that are characteristic of the quenched approximation in lattice QCD.
+We approximate the infinite sum by contributions from the lowest four vector
+mesons of the tower which turn out to saturate the charge and magnetic moment
+sum rules within a few percent and compute them totally free of unknown
+parameters for momentum transfers Q^2 less than 1GeV^2. We identify certain
+observables that can be reliably computed within the approximations and others
+that are not, and discuss how the improvement of the latter can enable one to
+bring holographic QCD closer to QCD proper.",0710.4615v2
+2007-12-10,Quantum well states in Fe/Nb(001) multilayers: First principles study,"We present a first-principles study to understand the phenomena of interlayer
+exchange coupling in Fe/Nb multilayers using the linearized-muffin-tin-orbitals
+method within the generalized gradient approximation. We find that the exchange
+coupling oscillates with both short and long periodicities, which have been
+examined in terms of the Ruderman-Kittel-Kasuya-Yosida (RKKY) model as well as
+the quantum well (QW) model. We have investigated the behavior of the exchange
+coupling by artificially varying moments of Fe atoms in ferromagnetic layers.
+For a small moment of Fe, the coupling shows bilinearity in the magnetic
+moments, implying its RKKY character. However, at higher moments close to that
+of bulk Fe, the saturation of long-period oscillations is in accordance with
+the QW model. Quantum well dispersions around the Fermi level demonstrate that
+the majority-spin bands contribute largely to the formation of quantum well
+states, which we analyze quantitatively by making use of the phase accumulation
+model. Our analysis indicates that the quantum well model gives a better
+description of the oscillatory behavior of the exchange coupling in Fe/Nb
+multilayers.",0712.1432v1
+2008-01-14,A note on the extensivity of the holographic entanglement entropy,"We consider situations where the renormalized geometric entropy, as defined
+by the AdS/CFT ansatz of Ryu and Takayanagi, shows extensive behavior in the
+volume of the entangled region. In general, any holographic geometry that is
+`capped' in the infrared region is a candidate for extensivity provided the
+growth of minimal surfaces saturates at the capping region, and the induced
+metric at the `cap' is non-degenerate. Extensivity is well-known to occur for
+highly thermalized states. In this note, we show that the holographic ansatz
+predicts the persistence of the extensivity down to vanishing temperature, for
+the particular case of conformal field theories in 2+1 dimensions with a
+magnetic field and/or electric charge condensates.",0801.2153v3
+2008-02-08,"Superconducting Transition in the $β$-Pyrochlore AOs$_2$O$_6$ (A=Cs, Rb, K) under Pressure","Pressure dependence of superconducting transition temperature $T_{\rm c}$ has
+been determined through the DC magnetic measurements under pressure up to
+$P$=10 GPa for $\beta$-pyrochlore oxides AOs$_2$O$_6$ with A=Cs ($T_{\rm
+c}$=3.3 K), Rb (6.3 K) and K (9.6 K). Both for A=Rb and Cs, $T_{\rm c}$
+increases with increasing $P$ and shows a saturation at $T_{\rm cm}$$\sim$8.8
+K, which is considered as the upper limit of $T_{\rm c}$ inherent in
+AOs$_2$O$_6$. In contrast, the $T_{\rm c}-P$ curve for KOs$_2$O$_6$ shows a
+sharp maximum of $\sim$10 K at $P$$\sim$0.5 GPa, and $T_{\rm c}$ is higher than
+$T_{\rm cm}$ for 0$\leq$$P$$\leq$1.5GPa, suggesting the enhanced
+superconductivity due to the rattling of K ions.",0802.1179v1
+2008-05-22,Non-equilibrium of Ionization and the Detection of Hot Plasma in Nanoflare-heated Coronal Loops,"Impulsive nanoflares are expected to transiently heat the plasma confined in
+coronal loops to temperatures of the order of 10 MK. Such hot plasma is hardly
+detected in quiet and active regions, outside flares. During rapid and short
+heat pulses in rarified loops the plasma can be highly out of equilibrium of
+ionization. Here we investigate the effects of the non-equilibrium of
+ionization (NEI) on the detection of hot plasma in coronal loops.
+Time-dependent loop hydrodynamic simulations are specifically devoted to this
+task, including saturated thermal conduction, and coupled to the detailed
+solution of the equations of ionization rate for several abundant elements. In
+our simulations, initially cool and rarified magnetic flux tubes are heated to
+10 MK by nanoflares deposited either at the footpoints or at the loop apex. We
+test for different pulse durations, and find that, due to NEI effects, the loop
+plasma may never be detected at temperatures above ~5 MK for heat pulses
+shorter than about 1 min. We discuss some implications in the framework of
+multi-stranded nanoflare-heated coronal loops.",0805.3512v1
+2008-09-10,Investigating the high energy QCD approaches for prompt photon production at the LHC,"We investigate the rapidity and transverse momentum distributions of the
+prompt photon production at the CERN LHC energies considering the current
+perturbative QCD approaches for this scattering process. Namely, we compare the
+predictions from the usual NLO pQCD calculations to the the color dipole
+formalism, using distinct dipole cross sections. Special attention is paid to
+parton saturation models at high energies, which are expected to be important
+at the forward rapidities in pp collisions at the LHC.",0809.1884v1
+2008-09-24,Effect of Pt doping on the critical temperature and upper critical field in YNi2-xPtxB2C (x=0-0.2),"We investigate the evolution of superconducting properties by doping
+non-magnetic impurity in single crystals of YNi2-xPtxB2C (x=0-0.2). With
+increasing Pt doping the critical temperature (Tc) monotonically decreases from
+15.85K and saturates to a value ~13K for x>0.14. However, unlike conventional
+s-wave superconductors, the upper critical field (HC2) along both
+crystallographic directions a and c decreases with increasing Pt doping.
+Specific heat measurements show that the density of states (N(EF)) at the Fermi
+level (EF) and the Debye temperatures (Theta_D) in this series remains constant
+within the error bars of our measurement. We explain our results based on the
+increase in intraband scattering in the multiband superconductor YNi2B2C.",0809.4274v1
+2008-12-05,Generic susceptibilities of the half-filled Hubbard model in infinite dimensions,"Around a metal-to-insulator transition driven by repulsive interaction (Mott
+transition) the single particle excitations and the collective excitations are
+equally important. Here we present results for the generic susceptibilities at
+zero temperature in the half-filled Hubbard model in infinite dimensions.
+Profiting from the high resolution of dynamic density-matrix renormalization at
+all energies, results for the charge, spin and Cooper-pair susceptibilities in
+the metallic and the insulating phase are computed. In the insulating phase, an
+almost saturated local magnetic moment appears. In the metallic phase a
+pronounced low-energy peak is found in the spin response.",0812.1071v2
+2009-01-09,Electron-electron interaction effects in quantum point contacts,"We consider electron-electron interaction effects in quantum point contacts
+on the first quantization plateau, taking into account all scattering
+processes. We compute the low-temperature linear and nonlinear conductance,
+shot noise, and thermopower, by perturbation theory and a self-consistent
+nonperturbative method. On the conductance plateau, the low-temperature
+corrections are solely due to momentum-nonconserving processes that change the
+relative number of left- and right-moving electrons. This leads to a
+suppression of the conductance for increasing temperature or voltage. The size
+of the suppression is estimated for a realistic saddle-point potential, and is
+largest in the beginning of the conductance plateau. For large magnetic field,
+interaction effects are strongly suppressed by the Pauli principle, and hence
+the first spin-split conductance plateau has a much weaker interaction
+correction. For the nonperturbative calculations, we use a self-consistent
+nonequilibrium Green's function approach, which suggests that the conductance
+saturates at elevated temperatures. These results are consistent with many
+experimental observations related to the so-called 0.7 anomaly.",0901.1183v1
+2009-01-30,Line-of-sight statistical methods for turbulent medium: VCS for emission and absorption lines,"We present an overview of the Velocity Coordinate Spectrum (VCS), a new
+technique for studying astrophysical turbulence that utilizes the line-of-sight
+statistics of Doppler-broadened spectral lines. We consider the retrieval of
+turbulence spectra from emission intensity observations of both high and low
+spatial resolution and find that the VCS allows one to study turbulence even
+when the emitting turbulent volume is not spatially resolved. This opens
+interesting prospects for using the technique for extragalactic research. VCS
+developed for spectral emission lines is applicable to absorption lines as well
+if the optical depth is used instead of intensity. VCS for absorption lines in
+point-source spectra benefit from effectively narrow beam and does not require
+dense sky coverage by sampling directions. Even strongly saturated absorption
+lines still carry the information about the small scale turbulence, albeit
+limited to the wings of a line. Combining different absorption lines one can
+develop tomography of the turbulence in the interstellar gas in all its
+complexity.",0902.0011v1
+2009-02-05,Temperature dependence of antiferromagnetic susceptibility in ferritin,"We show that antiferromagnetic susceptibility in ferritin increases with
+temperature between 4.2 K and 180 K (i. e. below the N\'{e}el temperature) when
+taken as the derivative of the magnetization at high fields ($30\times10^4$
+Oe). This behavior contrasts with the decrease in temperature previously found,
+where the susceptibility was determined at lower fields ($5\times10^4$ Oe). At
+high fields (up to $50 \times10^4$ Oe) the temperature dependence of the
+antiferromagnetic susceptibility in ferritin nanoparticles approaches the
+normal behavior of bulk antiferromagnets and nanoparticles considering
+superantiferromagnetism, this latter leading to a better agreement at high
+field and low temperature. The contrast with the previous results is due to the
+insufficient field range used ($< 5 \times10^4$ Oe), not enough to saturate the
+ferritin uncompensated moment.",0902.0929v1
+2009-02-10,Constraints on Neutron Star Crusts From Oscillations in Giant Flares,"We show that the fundamental seismic shear mode, observed as a quasi-periodic
+oscillation in giant flares emitted by highly-magnetized neutron stars, is
+particularly sensitive to the nuclear physics of the crust. The identification
+of an oscillation at ~ 30 Hz as the fundamental crustal shear mode requires a
+nuclear symmetry energy that depends very weakly on density near saturation. If
+the nuclear symmetry energy varies more strongly with density, then lower
+frequency oscillations, previously identified as torsional Alfven modes of the
+fluid core, could instead be associated with the crust. If this is the case,
+then future observations of giant flares should detect oscillations at around
+18 Hz. An accurate measurement of the neutron skin thickness of lead will also
+constrain the frequencies predicted by the model.",0902.1683v2
+2009-02-18,Non-linear spectroscopy of rubidium: An undergraduate experiment,"In this paper, we describe two complementary non-linear spectroscopy methods
+which both allow to achieve Doppler-free spectra of atomic gases. First,
+saturated absorption spectroscopy is used to investigate the structure of the
+$5{\rm S}_{1/2}\to 5{\rm P}_{3/2}$ transition in rubidium. Using a slightly
+modified experimental setup, Doppler-free two-photon absorption spectroscopy is
+then performed on the $5{\rm S}_{1/2}\to 5{\rm D}_{5/2}$ transition in
+rubidium, leading to accurate measurements of the hyperfine structure of the
+$5{\rm D}_{5/2}$ energy level. In addition, electric dipole selection rules of
+the two-photon transition are investigated, first by modifying the polarization
+of the excitation laser, and then by measuring two-photon absorption spectra
+when a magnetic field is applied close to the rubidium vapor. All experiments
+are performed with the same grating-feedback laser diode, providing an
+opportunity to compare different high resolution spectroscopy methods using a
+single experimental setup. Such experiments may acquaint students with quantum
+mechanics selection rules, atomic spectra and Zeeman effect.",0902.3115v1
+2009-03-13,Operator Space Entanglement Entropy in XY Spin Chains,"The complexity of representation of operators in quantum mechanics can be
+characterized by the operator space entanglement entropy (OSEE). We show that
+in the homogeneous Heisenberg XY spin 1/2 chains the OSEE for initial local
+operators grows at most logarithmically with time. The prefactor in front of
+the logarithm generally depends only on the number of stationary points of the
+quasi-particle dispersion relation and for the XY model changes from 1/3 to 2/3
+exactly at the point of quantum phase transition to long-range magnetic
+correlations in the non-equilibrium steady state. In addition, we show that the
+presence of a small disorder triggers a saturation of the OSEE.",0903.2432v3
+2009-03-23,Entanglement entropy with localized and extended interface defects,"The quantum Ising chain of length, L, which is separated into two parts by
+localized or extended defects is considered at the critical point where scaling
+of the interface magnetization is non-universal. We measure the entanglement
+entropy between the two halves of the system in equilibrium, as well as after a
+quench, when the interaction at the interface is changed for time t>0. For the
+localized defect the increase of the entropy with log(L) or with log(t)
+involves the same effective central charge, which is a continuous function of
+the strength of the defect. On the contrary for the extended defect the
+equilibrium entropy is saturated, but the non-equilibrium entropy has a
+logarithmic time-dependence the prefactor of which depends on the strength of
+the defect.",0903.3740v1
+2009-05-12,Reconstructing the Neutron-Star Equation of State from Astrophysical Measurements,"The properties of matter at ultra-high densities, low temperatures, and with
+a significant asymmetry between protons and neutrons can be studied exclusively
+through astrophysical observations of neutron stars. We show that measurements
+of the masses and radii of neutron stars can lead to tight constraints on the
+pressure of matter at three fiducial densities, from 1.85 to 7.4 times the
+density of nuclear saturation, in a manner that is largely model-independent
+and that captures the key characteristics of the equation of state. We
+demonstrate that observations with 10% uncertainties of at least three neutron
+stars can lead to measurements of the pressure at these fiducial densities with
+an accuracy of 0.11 dex or ~ 30%. Observations of three neutron stars with 5%
+uncertainties are sufficient to distinguish at a better than 3-sigma confidence
+level between currently proposed equations of state. In the electromagnetic
+spectrum, such accurate measurements will become possible for weakly-magnetic
+neutron stars during thermonuclear flashes and in quiescence with future
+missions such as the International X-ray Observatory (IXO).",0905.1959v2
+2009-05-24,Muon-spin rotation measurements of the penetration depth of the Mo_3Sb_7 superconductor,"Measurements of the magnetic field penetration depth \lambda in
+superconductor Mo_3Sb_7 (T_c~2.1 K) were carried out by means of
+muon-spin-rotation. The absolute values of \lambda, the Ginzburg-Landau
+parameter \kappa, the first H_{c1} and the second H_{c2} critical fields at T=0
+are \lambda(0)=720(100)nm, \kappa(0)=55(9), \mu_0H_{c1}(0)=1.8(3)mT, and
+\mu_0H_{c2}(0)=1.9(2)T. The zero temperature value of the superconducting
+energy gap \Delta(0) was found to be 0.35(1)meV corresponding to the ratio
+2\Delta(0)/k_BT_c=3.83(10). At low temperatures \lambda^{-2}(T) saturates and
+becomes constant below T~0.3T_c, in agreement with what is expected for s-wave
+BCS superconductors. Our results suggest that Mo_3Sb_7 is a BCS superconductor
+with the isotropic energy gap",0905.3906v1
+2009-05-24,Frequency and temperature dependence of the anomalous Hall conductivity in a chiral px+ipy superconductor with impurities,"We calculate frequency and temperature dependence of the anomalous ac Hall
+conductivity induced by impurity scattering in a chiral px+ipy superconductor,
+such as Sr2RuO4, with spontaneous time-reversal-symmetry breaking in the
+absence of an external magnetic field. We consider two models of disorder,
+Gaussian and non-Gaussian, characterized by the second and third moments of the
+random impurity potential, respectively. Within both models, we find that the
+anomalous Hall conductivity has a finite real value at zero frequency, exhibits
+singularities at the threshold of photon absorption across the superconducting
+gap, and decays as some power of the high frequency \Omega. The Hall
+conductivity increases linearly with the decrease of temperature below the
+superconducting transition and saturates at zero temperature. Using our results
+for the high-frequency Hall conductivity, we estimate the polar Kerr angle for
+light reflection from the material and compare it with the experimental
+measurements in Sr2RuO4 by Xia et al., Phys. Rev. Lett. 97, 167002 (2006).",0905.3918v3
+2009-06-27,Negative and Positive Magnetoresistance in Bilayer Graphene: Effects of Weak Localization and Charge Inhomogeneity,"We report measurements of magnetoresistance in bilayer graphene as a function
+of gate voltage (carrier density) and temperature. We examine multiple
+contributions to the magnetoresistance, including those of weak localization
+(WL), universal conductance fluctuations (UCF), and inhomogeneous charge
+transport. A clear WL signal is evident at all measured gate voltages (in the
+hole doped regime) and temperature ranges (from 0.25 K to 4.3 K), and the phase
+coherence length extracted from WL data does not saturate at low temperatures.
+The WL data is fit to demonstrate that electron-electron Nyquist scattering is
+the major source of phase decoherence. A decrease in UCF amplitude with
+increasing gate voltage and temperature is shown to be consistent with a
+corresponding decrease in the phase coherence length. In addition, a weak
+positive magnetoresistance at higher magnetic fields is observed, and
+attributed to inhomogeneous charge transport.",0906.5090v2
+2009-07-07,On a stochastic model for the spin-down of solar type stars,"Modeling the rotation history of solar-type stars is still an unsolved
+problem in modern astrophysics. One of the main challenges is to explain the
+dispersion in the distribution of stellar rotation rate for young stars.
+Previous works have advocated dynamo saturation or magnetic field localization
+to explain the presence of fast rotators and star-disk coupling in pre-main
+sequence to account for the existence of slow rotators. Here, we present a new
+model that can account for the presence of both types of rotators by
+incorporating fluctuations in the solar wind. This renders the spin-down
+problem probabilistic in nature, some stars experiencing more braking on
+average than others. We show that random fluctuations in the loss of angular
+momentum enhance the population of both fast and slow rotators compared to the
+deterministic case. Furthermore, the distribution of rotational speed is
+severely skewed towards large values in agreement with observations.",0907.1226v1
+2009-07-21,Confinement of electrons in size modulated silicon nanowires,"Based on first-principles calculations we showed that superlattices of
+periodically repeated junctions of hydrogen saturated silicon nanowire segments
+having different lengths and diameters form multiple quantum well structures.
+The band gap of the superlattice is modulated in real space as its diameter
+does and results in a band gap in momentum space which is different from
+constituent nanowires. Specific electronic states can be confined in either
+narrow or wide regions of superlattice. The type of the band lineup and hence
+the offsets of valence and conduction bands depend on the orientation of the
+superlattice as well as on the diameters of the constituent segments. Effects
+of the SiH vacancy and substitutional impurities on the electronic and magnetic
+properties have been investigated by carrying out spin-polarized calculations.
+Substitutional impurities with localized states near band edges can make
+modulation doping possible. Stability of the superlattice structure was
+examined by ab initio molecular dynamics calculations at high temperatures.",0907.3591v1
+2009-09-30,Doppler-free laser spectroscopy of buffer gas cooled molecular radicals,"We demonstrate Doppler-free saturated absorption spectroscopy of cold
+molecular radicals formed by laser ablation inside a cryogenic buffer gas cell.
+By lowering the temperature, congested regions of the spectrum can be
+simplified, and by using different temperatures for different regions of the
+spectrum a wide range of rotational states can be studied optimally. We use the
+technique to study the optical spectrum of YbF radicals with a resolution of 30
+MHz, measuring the magnetic hyperfine parameters of the electronic ground
+state. The method is suitable for high resolution spectroscopy of a great
+variety of molecules at controlled temperature and pressure, and is
+particularly well-suited to those that are difficult to produce in the gas
+phase.",0909.5534v2
+2009-10-05,Isotope shifts and hyperfine structure of the Fe I 372 nm resonance line,"We report measurements of the isotope shifts of the $3d^64s^2 a ^5D_4 -
+3d^64s4p z ^5F_5^o$ Fe I resonance line at 372 nm between all four stable
+isotopes $^{54}$Fe, $^{56}$Fe, $^{57}$Fe, and $^{58}$Fe, as well as the
+complete hyperfine structure of that line for $^{57}$Fe, the only stable
+isotope having a non-zero nuclear spin. The field and specific mass shift
+coefficients of the transition have been derived from the data, as well as the
+experimental value for the hyperfine structure magnetic dipole coupling
+constant $A$ of the excited state of the transition in $^{57}$Fe: $A(3d^64s4p z
+^5F_5^o) = 81.69(86)$ MHz. The measurements were done by means of Doppler-free
+laser saturated-absorption spectroscopy in a Fe-Ar hollow cathode using both
+natural and enriched iron samples. The measured isotope shifts and hyperfine
+constants are reported with uncertainties at the percent level.",0910.0479v1
+2009-10-07,Entanglement in a spin system with inverse square statistical interaction,"We investigate the entanglement content of the ground state of a system
+characterized by effective elementary degrees of freedom with fractional
+statistics. To this end, we explicitly construct the ground state for a chain
+of $N$ spins with inverse square interaction (the Haldane-Shastry model) in the
+presence of an external uniform magnetic field. For such a system at zero
+temperature, we evaluate the entanglement in the ground state both at finite
+size and in the thermodynamic limit. We relate the behavior of the quantum
+correlations with the spinon condensation phenomenon occurring at the
+saturation field.",0910.1227v2
+2009-10-09,Dynamics of Fully Nonlinear Drift Wave-Zonal Flow Turbulence System in Plasmas,"We present numerical simulations of fully nonlinear drift wave-zonal flow
+(DW-ZF) turbulence systems in a nonuniform magnetoplasma. In our model, the
+drift wave (DW) dynamics is pseudo-three-dimensional (pseudo-3D) and accounts
+for self-interactions among finite amplitude DWs and their coupling to the
+two-dimensional (2D) large amplitude zonal flows (ZFs). The dynamics of the 2D
+ZFs in the presence of the Reynolds stress of the pseudo-3D DWs is governed by
+the driven Euler equation. Numerical simulations of the fully nonlinear coupled
+DW-ZF equations reveal that shortscale DW turbulence leads to nonlinear
+saturated dipolar vortices, whereas the ZF sets in spontaneously and is
+dominated by a monopolar vortex structure. The ZFs are found to suppress the
+cross-field turbulent particle transport. The present results provide a better
+model for understanding the coexistence of short- and large-scale coherent
+structures, as well as associated subdued cross-field particle transport in
+magnetically confined fusion plasmas.",0910.1635v2
+2009-12-08,Coupling Photosphere and Corona: Linear and Turbulent Regimes,"In a recent work Grappin et al. [1] have shown that low- frequency movements
+can be transmitted from one footpoint to the other along a magnetic loop, thus
+mimicking a friction effect of the corona on the photosphere, and invalidating
+the line-tying approximation. We consider here successively the effect of high
+frequencies and turbulent damping on the process. We use a very simple
+atmospheric model which allows to study analytically the laminar case, and to
+study the turbulent case both using simple phenomenological arguments and a
+more sophisticated turbulence model [2]. We find that, except when turbulent
+damping is such that all turbulence is damped during loop traversal, coupling
+still occurs between distant footpoints, and moreover the coronal field induced
+by photospheric movements saturates at finite values.",0912.1497v1
+2009-12-11,Direct observation of electronic inhomogeneities induced by point defect disorder in manganite films,"We have investigated the influence of point defect disorder in the electronic
+properties of manganite films. Real-time mapping of ion irradiated samples
+conductivity was performed though conductive atomic force microscopy (CAFM).
+CAFM images show electronic inhomogeneities in the samples with different
+physical properties due to spatial fluctuations in the point defect
+distribution. As disorder increases, the distance between conducting regions
+increases and the metal-insulator transition shifts to lower temperatures.
+Transport properties in these systems can be interpreted in terms of a
+percolative model. The samples saturation magnetization decreases as the
+irradiation dose increases whereas the Curie temperature remains unchanged.",0912.2233v1
+2010-01-11,Pauli-limited upper critical field in Fe1+yTe1-xSex,"In this work we investigated the temperature dependence of the upper critical
+field u0Hc2(T) of Fe1.02(3)Te0.61(4)Se0.39(4) and Fe1.05(3)Te0.89(2)Se0.11(2)
+single crystals by measuring the magnetotransport properties in stable dc
+magnetic fields up to 35 T. Both crystals show that u0Hc2(T) in the ab-plane
+and along the c-axis exhibit saturation at low temperatures. The anisotropy of
+u0Hc2(T) decreases with decreasing temperature, becoming nearly isotropic when
+the temperature T->0. Furthermore, u0Hc2(0) deviates from the conventional
+Werthamer-Helfand-Hohenberg (WHH) theoretical prediction values for both field
+directions. Our analysis indicates that the spin-paramagnetic pair-breaking
+effect is responsible for the temperature-dependent behavior of u0Hc2(T) in
+both field directions.",1001.1751v3
+2010-01-18,Density Effects on the Negative Refractive Index of a Split Ring Resonator Metamaterial,"Perfect lensing and cloaking based on complementary media are possible
+applications of negative refractive index materials. Metamaterials represent
+the natural candidates to realize such property by tailoring the effective
+dielectric permittiviy and magnetic permeability. The fine tuning of $n<0$ of
+metamaterials is limited by coarse grained inclusions which give discreteness
+to the electromagnetic parameters as a function of their density. We study the
+negative refractive index of a metamaterial as a function of the linear density
+of the lattice period at microwave frequency. The negative refractive index is
+obtained by a waveguide filled with a split ring resonator array in a frequency
+band below the cut off frequency of the waveguide. The special value of $n=-1$
+typical of perfect lensing is maintained by tuning the density on a bandwidth
+of 1 GHz. A cut-off density above which the metamaterial operates is observed.
+A second critical density above which the transmission saturates is found close
+to the Pendry limit. Such results on the density of negative refractive index
+metamaterials open new paths towards the fine tuning of constitutive parameters
+at wanted values by means of transformation optics.",1001.2976v2
+2010-03-10,Effects of excess Fe on upper critical field and magnetotransport in Fe1+y(Te1-xSx)z,"We have investigated the upper critical field anisotropy and magnetotransport
+properties of Fe1.14(1)Te0.91(2)S0.09(2) single crystals in stable magnetic
+fields up to 35 T. The results show that u0Hc2(T) along the c axis and in the
+ab-plane exhibit saturation at low temperatures. The anisotropy of u0Hc2(T)
+decreases with decreasing temperature, becoming nearly isotropic for T->0. Our
+analysis indicates that the spin-paramagnetic pair-breaking with spin-orbital
+scattering is responsible for the behavior of u0Hc2(T). Furthermore, from
+analysis of the normal state properties, we show evidence that the excess Fe
+acting as Kondo-type impurities is a key factor determining the normal and
+superconducting state physical properties.",1003.2209v1
+2010-05-28,Growth and characterization of multiferroic BiMnO$_3$ thin films,"We have grown epitaxial thin films of multiferroic BiMnO$_3$ using pulsed
+laser deposition. The films were grown on SrTiO$_3$ (001) substrates by
+ablating a Bi-rich target. Using x-ray diffraction we confirmed that the films
+were epitaxial and the stoichiometry of the films was confirmed using Auger
+electron spectroscopy. The films have a ferromagnetic Curie temperature ($T_C$)
+of 85$\pm$5 K and a saturation magnetization of 1 $\mu_B$/Mn. The electric
+polarization as a function of electric field ($P-E$) was measured using an
+interdigital capacitance geometry. The $P-E$ plot shows a clear hysteresis that
+confirms the multiferroic nature of the thin films.",1005.5404v1
+2010-05-30,Quasi-1d quantum helimagnets: The fate of multipolar phases,"Coupled frustrated spin-1/2 chains in high magnetic fields described within
+the ferro- antiferromagnetic J1-J2 Heisenberg model are studied by the DMRG,
+the hard core boson, and the spin wave theory approaches. Multipolar phases
+related to magnon bound states are destroyed (supported) by weak
+antiferromagnetic (ferromagnetic) interchain couplings Jic. We show that
+quantum spin nematics might be found for LiVCuO4 whereas for Li(Na)Cu2O2 it is
+prevented by a sizeable antiferromagnetic Jic. Also for Li2ZrCuO4 with a small
+antiferromagnetic Jic expected triatic or quartic phases are unlikely, too. The
+saturation field is found to be strongly affected even by a relatively small
+Jic.",1005.5500v2
+2010-07-13,Exact results on the quench dynamics of the entanglement entropy in the toric code,"We study quantum quenches in the two-dimensional Kitaev toric code model and
+compute exactly the time-dependent entanglement entropy of the non-equilibrium
+wave-function evolving from a paramagnetic initial state with the toric code
+Hamiltonian. We find that the area law survives at all times. Adding disorder
+to the toric code couplings makes the entanglement entropy per unit boundary
+length saturate to disorder-independent values at long times and in the
+thermodynamic limit. There are order-one corrections to the area law from the
+corners in the subsystem boundary but the topological entropy remains zero at
+all times. We argue that breaking the integrability with a small magnetic field
+could change the area law to a volume scaling as expected of thermalized states
+but is not sufficient for forming topological entanglement due to the presence
+of an excess energy and a finite density of defects.",1007.2014v3
+2010-08-06,Long ranged interactions in carbon atomic chains,"Based on first-principles calculations we revealed fundamental properties of
+infinite and finite size monatomic chains of carbon atoms in equilibrium and
+under an applied strain. Distributions of bond lengths and magnetic moments at
+atomic sites exhibit interesting even-odd disparity depending on the number of
+carbon atoms in the chain and on the type of saturation of carbon atoms at both
+ends. It was shown that, the $\pi$-bands of carbon atomic chains behave as a
+one dimensional free electron system. A local perturbation created by a small
+displacement of the single carbon atom at the center of a long chain induces
+oscillations of atomic forces and charge density, which are carried to long
+distances over the chain. These long ranged oscillations are identified as
+Friedel oscillations showing $1/r$ decay rate in one dimensional systems.",1008.1126v2
+2010-08-31,Quantitative atomic spectroscopy for primary thermometry,"Quantitative spectroscopy has been used to measure accurately the
+Doppler-broadening of atomic transitions in $^{85}$Rb vapor. By using a
+conventional platinum resistance thermometer and the Doppler thermometry
+technique, we were able to determine $k_B$ with a relative uncertainty of
+$4.1\times 10^{-4}$, and with a deviation of $2.7\times 10^{-4}$ from the
+expected value. Our experiment, using an effusive vapour, departs significantly
+from other Doppler-broadened thermometry (DBT) techniques, which rely on weakly
+absorbing molecules in a diffusive regime. In these circumstances, very
+different systematic effects such as magnetic sensitivity and optical pumping
+are dominant. Using the model developed recently by Stace and Luiten, we
+estimate the perturbation due to optical pumping of the measured $k_B$ value
+was less than $4\times 10^{-6}$. The effects of optical pumping on atomic and
+molecular DBT experiments is mapped over a wide range of beam size and
+saturation intensity, indicating possible avenues for improvement. We also
+compare the line-broadening mechanisms, windows of operation and detection
+limits of some recent DBT experiments.",1008.5229v3
+2010-09-02,Phase-space characterization of complexity in quantum many-body dynamics,"We propose a phase-space Wigner harmonics entropy measure for many-body
+quantum dynamical complexity. This measure, which reduces to the well known
+measure of complexity in classical systems and which is valid for both pure and
+mixed states in single-particle and many-body systems, takes into account the
+combined role of chaos and entanglement in the realm of quantum mechanics. The
+effectiveness of the measure is illustrated in the example of the Ising chain
+in a homogeneous tilted magnetic field. We provide numerical evidence that the
+multipartite entanglement generation leads to a linear increase of entropy
+until saturation in both integrable and chaotic regimes, so that in both cases
+the number of harmonics of the Wigner function grows exponentially with time.
+The entropy growth rate can be used to detect quantum phase transitions. The
+proposed entropy measure can also distinguish between integrable and chaotic
+many-body dynamics by means of the size of long term fluctuations which become
+smaller when quantum chaos sets in.",1009.0560v1
+2010-09-07,Mesoscopic transport in ultrathin films of La$_{0.67}$Ca$_{0.33}$MnO$_3$,"We investigate the electrical transport in mesoscopic structures of
+La$_{0.67}$Ca$_{0.33}$MnO$_3$ in the regime of the metal-insulator transition
+by fabricating microbridges from strained and unstrained thin films. We measure
+current-voltage characteristics as function of temperature and in high magnetic
+fields and with varying film thickness. For strained films, in warming from the
+metallic to the insulating state, we find non-linear effects in the steep part
+of the transition characterized by a differential resistance with a strong peak
+around zero applied current, and saturating at higher currents after resistance
+drops up to 60 %. We propose that this nonlinear behavior is associated with
+melting of the insulating state by injecting charge carriers, signalling the
+occurrence of an intervening phase which involves the formation of short range
+polaron correlations.",1009.1386v1
+2010-09-09,"Structure and stability of graphene nanoribbons in oxygen, carbon dioxide, water, and ammonia","We determine, by means of density functional theory, the stability and the
+structure of graphene nanoribbon (GNR) edges in presence of molecules such as
+oxygen, water, ammonia, and carbon dioxide. As in the case of
+hydrogen-terminated nanoribbons, we find that the most stable armchair and
+zigzag configurations are characterized by a non-metallic/non-magnetic nature,
+and are compatible with Clar's sextet rules, well known in organic chemistry.
+In particular, we predict that, at thermodynamic equilibrium, neutral GNRs in
+oxygen-rich atmosphere should preferentially be along the armchair direction,
+while water-saturated GNRs should present zigzag edges. Our results promise to
+be particularly useful to GNRs synthesis, since the most recent and advanced
+experimental routes are most effective in water and/or ammonia-containing
+solutions.",1009.1808v1
+2010-09-09,(Ir-)Reversibility and thermal equilibrium in magnetic domain pattern formation in ultra-thin ferromagnetic films,"We investigate the details of pattern formation and transitions between
+different modulated phases in ultra-thin Fe films on Cu(001). At high
+temperature, the transitions between the uniform saturated state, the bubble
+state and the striped state are completely reversible, while at low temperature
+the bubble phase is avoided. The observed non-equilibrium behavior can be
+qualitatively explained by considering the intrinsic energy barriers appearing
+in the system due to the competition between the short-ranged exchange and the
+long-ranged dipolar interactions. Our experiments suggest that the height of
+these energy barriers is related to the domain size and is therefore strongly
+temperature dependent.",1009.1815v1
+2010-09-20,Ultra-high energy nuclei source in the direction to Virgo cluster,"The significant anisotropy in the arrival directions of the 69 events with
+energy E> 55 EeV detected by Pierre Auger collaboration is located in the
+20-degree region centered near Cen A. Not only the 2-point, but also the
+3-point and 4-point autocorrelation functions are completely saturated by this
+region. Besides there is an deficit of events in the direction of Virgo
+cluster. If one assumes that the excess around Cen A is due to heavy nuclei
+shifted from Virgo, one can explain 20-degree scale of this anomaly. Also
+location of the highest energy event between the Cen A region and the Virgo
+cluster supports this idea. Magnitude and direction of the magnetic field is
+similar in this case to those expected for Galactic models. The existence of
+nuclei sources in the sky opens the road for a self-consistent description of
+Auger data.",1009.3879v1
+2010-11-01,On the Bogomol'nyi bound in Einstein-Maxwell-dilaton gravity,"It has been shown that the 4-dimensional Einstein-Maxwell-dilaton theory
+allows a Bogomol'nyi-type inequality for an arbitrary dilaton coupling constant
+$\alpha $, and that the bound is saturated if and only if the (asymptotically
+flat) spacetime admits a nontrivial spinor satisfying the gravitino and the
+dilatino Killing spinor equations. The present paper revisits this issue and
+argues that the dilatino equation fails to ensure the dilaton field equation
+unless the solution is purely electric/magnetic, or the dilaton coupling
+constant is given by $\alpha=0, \sqrt 3$, corresponding to the
+Brans-Dicke-Maxwell theory and the Kaluza-Klein reduction of 5-dimensional
+vacuum gravity, respectively. A systematic classification of the supersymmetric
+solutions reveals that the solution can be rotating if and only if the solution
+is dyonic or the coupling constant is given by $\alpha=0, \sqrt 3$. This
+implies that the theory with $\alpha \ne 0, \sqrt 3$ cannot be embedded into
+supergravity except for the static truncation. Physical properties of
+supersymmetric solutions are explored from various points of view.",1011.0261v2
+2011-01-05,Alfvén waves and ideal two-dimensional Galerkin truncated magnetohydrodynamics,"We investigate numerically the dynamics of two-dimensional Euler and ideal
+magnetohydrodynamics (MHD) flows in systems with a finite number of modes, up
+to $4096^2$, for which several quadratic invariants are preserved by the
+truncation and the statistical equilibria are known. Initial conditions are the
+Orszag-Tang vortex with a neutral X-point centered on a stagnation point of the
+velocity field in the large scales. In MHD, we observe that the total energy
+spectra at intermediate times and intermediate scales correspond to the
+interactions of eddies and waves, $E_T(k)\sim k^{-3/2}$. Moreover, no
+dissipative range is visible neither for Euler nor for MHD in two dimensions;
+in the former case, this may be linked to the existence of a vanishing
+turbulent viscosity whereas in MHD, the numerical resolution employed may be
+insufficient. When imposing a uniform magnetic field to the flow, we observe a
+lack of saturation of the formation of small scales together with a significant
+slowing-down of their equilibration, with however a cut-off independent partial
+thermalization being reached at intermediate scales.",1101.1078v1
+2011-03-31,High Q-factor Sapphire Whispering Gallery Mode Microwave Resonator at Single Photon Energies and milli-Kelvin Temperatures,"The microwave properties of a crystalline sapphire dielectric whispering
+gallery mode resonator have been measured at very low excitation strength
+(E/hf=1) and low temperatures (T = 30 mK). The measurements were sensitive
+enough to observe saturation due to a highly detuned electron spin resonance,
+which limited the loss tangent of the material to about 2e-8 measured at 13.868
+and 13.259 GHz. Small power dependent frequency shifts were also measured which
+correspond to an added magnetic susceptibility of order 1e-9. This work shows
+that quantum limited microwave resonators with Q-factors > 1e8 are possible
+with the implementation of a sapphire whispering gallery mode system.",1103.6094v2
+2011-04-13,Current induced vortex superlattices in nanomagnets,"Influence of the spin-transfer torque on the vortex state magnetic nanodisk
+is studied numerically via Slonczewski-Berger mechanism. The existence of a
+critical current is determined for the case of same-directed electrical
+current, its spin polarization and polarity of the vortex. The critical current
+separates two regimes: (i) deformed but static vortex state and (ii)
+essentially dynamic state under which the spatio-temporal periodic structures
+can appear. The structure is a stable vortex-antivortex lattice. Symmetry of
+the lattice depends on the applied current value and for high currents (close
+to saturation) only square lattices are observed. General relations for sizes
+of the stable lattice is obtained analytically.",1104.2483v1
+2011-05-04,"Diffusion of Mn interstitials in (Ga,Mn)As epitaxial layers","Magnetic properties of thin (Ga,Mn)As layers improve during annealing by
+out-diffusion of interstitial Mn ions to a free surface. Out-diffused Mn atoms
+participate in the growth of a Mn-rich surface layer and a saturation of this
+layer causes an inhibition of the out-diffusion. We combine high-resolution
+x-ray diffraction with x-ray absorption spectroscopy and a numerical solution
+of the diffusion problem for the study of the out-diffusion of Mn interstitials
+during a sequence of annealing steps. Our data demonstrate that the
+out-diffusion of the interstitials is substantially affected by the internal
+electric field caused by an inhomogeneous distribution of charges in the
+(Ga,Mn)As layer.",1105.0849v1
+2011-05-17,Superconductivity and ferromagnetism in EuFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$,"Superconductivity and ferromagnetism are two antagonistic cooperative
+phenomena, which makes it difficult for them to coexist. Here we demonstrate
+experimentally that they do coexist in EuFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ with
+$0.2\leq x\leq0.4$, in which superconductivity is associated with Fe-3$d$
+electrons and ferromagnetism comes from the long-range ordering of Eu-4$f$
+moments via Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions. The coexistence
+is featured by large saturated ferromagnetic moments, high and comparable
+superconducting and magnetic transition temperatures, and broad coexistence
+ranges in temperature and field. We ascribe this unusual phenomenon to the
+robustness of superconductivity as well as the multi-orbital characters of iron
+pnictides.",1105.3255v1
+2011-07-20,The Capabilities of a Perturbed Toric Code as a Quantum Memory,"We analyze the effect of typical, unknown perturbations on the 2D toric code
+when acting as a quantum memory, incorporating the effects of error correction
+on read-out. By transforming the system into a 1D transverse Ising model
+undergoing an instantaneous quench, and making extensive use of Lieb-Robinson
+bounds, we prove that for a large class of perturbations, the survival time of
+stored information grows at least logarithmically with the system size. A
+uniform magnetic field saturates this scaling behavior. We show that
+randomizing the stabilizer strengths gives a polynomial survival time with a
+degree that depends on the strength of the perturbation.",1107.3940v3
+2011-09-19,Quantum spin liquid in frustrated one dimensional LiCuSbO4,"A quantum magnet, LiCuSbO4, with chains of edge-sharing S = 1/2 CuO6
+octahedra is reported. While the Curie-Weiss constant is ferromagnetic, \theta
+= 30 K, no phase transition or spin freezing occurs down to 100 mK. Specific
+heat indicates a distinct high field phase near the 12 T saturation field.
+Neutron scattering shows incommensurate spin correlations with q =
+0.47\pm0.01{\pi}/a and places an upper limit of 70 \mueV on a potential spin
+gap. Exact diagonalization of easy plane S = 1/2 chains with competing ferro-
+and antiferromagnetic interactions (J1 = - 75 K, J2 = 34 K) accounts for the T
+> 2 K data.",1109.4061v4
+2011-11-08,"A mechanism giving a finite value to the speed of light, and some experimental consequences","We admit that the vacuum is not empty but is filled with continuously
+appearing and disappearing virtual fermion pairs. We show that if we simply
+model the propagation of the photon in vacuum as a series of transient captures
+within the virtual pairs, we can derive the finite light velocity $c$ as the
+average delay on the photon propagation. We then show that the vacuum
+permittivity $\epsilon_0$ and permeability $\mu_0$ originate from the
+polarization and the magnetization of the virtual fermions pairs. Since the
+transit time of a photon is a statistical process within this model, we expect
+it to be fluctuating. We discuss experimental tests of this prediction. We also
+study vacuum saturation effects under high photon density conditions.",1111.1847v1
+2011-12-06,Entanglement of two harmonic modes coupled by angular momentum,"We examine the entanglement induced by an angular momentum coupling between
+two harmonic systems. The Hamiltonian corresponds to that of a charged particle
+in a uniform magnetic field in an anisotropic quadratic potential, or
+equivalently, to that of a particle in a rotating quadratic potential. We
+analyze both the vacuum and thermal entanglement, obtaining analytic
+expressions for the entanglement entropy and negativity through the gaussian
+state formalism. It is shown that vacuum entanglement diverges at the edges of
+the dynamically stable sectors, increasing with the angular momentum and
+saturating for strong fields, whereas at finite temperature, entanglement is
+non-zero just within a finite field or frequency window and no longer diverges.
+Moreover, the limit temperature for entanglement is finite in the whole stable
+domain. The thermal behavior of the gaussian quantum discord and its difference
+with the negativity is also discussed.",1112.1441v1
+2011-12-27,Absorbing states of zero-temperature Glauber dynamics in random networks,"We study zero-temperature Glauber dynamics for Ising-like spin variable
+models in quenched random networks with random zero-magnetization initial
+conditions. In particular, we focus on the absorbing states of finite systems.
+While it has quite often been observed that Glauber dynamics lets the system be
+stuck into an absorbing state distinct from its ground state in the
+thermodynamic limit, very little is known about the likelihood of each
+absorbing state. In order to explore the variety of absorbing states, we
+investigate the probability distribution profile of the active link density
+after saturation as the system size $N$ and $<k >$ vary. As a result, we find
+that the distribution of absorbing states can be split into two self-averaging
+peaks whose positions are determined by $<k>$, one slightly above the ground
+state and the other farther away. Moreover, we suggest that the latter peak
+accounts for a non-vanishing portion of samples when $N$ goes to infinity while
+$<k >$ stays fixed. Finally, we discuss the possible implications of our
+results on opinion dynamics models.",1112.5927v2
+2012-01-09,The role of boundaries in the MagnetoRotational Instability,"In this paper, we investigate numerically the flow of an electrically
+conducting fluid in a cylindrical Taylor-Couette flow when an axial magnetic
+field is applied. To minimize Ekman recirculation due to vertical no-slip
+boundaries, two independently rotating rings are used at the vertical endcaps.
+This configuration reproduces setup used in laboratory experiments aiming to
+observe the MagnetoRotational Instability (MRI). Our 3D global simulations show
+that the nature of the bifurcation, the non-linear saturation, and the
+structure of axisymmetric MRI modes are significantly affected by the presence
+of boundaries. In addition, large scale non-axisymmetric modes are obtained
+when the applied field is sufficiently strong. We show that these modes are
+related to Kelvin-Helmoltz destabilization of a free Shercliff shear layer
+created by the combined action of the applied field and the rotating rings at
+the endcaps. Finally, we compare our numerical simulations to recent
+experimental results obtained in the Princeton MRI experiment.",1201.1853v1
+2012-01-13,Linear and Weakly Nonlinear Analysis of the Magneto-Rotational-Instability in Thin Keplerian Discs,"The linear instability of thin, vertically-isothermal Keplerian discs, under
+the influence of axial magnetic field is investigated. Solutions of the
+stability problem are found explicitly by asymptotic expansions in the small
+aspect ratio of the disc. It is shown that the perturbations are decoupled into
+in-plane and vertical modes. Exact expressions for the growth rates as well as
+the number of unstable modes are derived. Those are the discrete counterpart of
+the continuous infinite homogeneous cylinder magnetorotational (MRI) spectrum.
+In addition, a weakly nonlinear analysis of the MRI is performed. It is shown
+that near the instability threshold the latter is saturated by the stable
+magnetoacoustic modes.",1201.2847v1
+2012-01-27,Giant negative magnetoresistance in high-mobility 2D electron systems,"We report on a giant negative magnetoresistance in very high mobility
+GaAs/AlGaAs heterostructures and quantum wells. The effect is the strongest at
+$B \simeq 1$ kG, where the magnetoresistivity develops a minimum emerging at $T
+\lesssim 2$ K. Unlike the zero-field resistivity which saturates at $T \simeq 2
+$ K, the resistivity at this minimum continues to drop at an accelerated rate
+to much lower temperatures and becomes several times smaller than the
+zero-field resistivity. Unexpectedly, we also find that the effect is destroyed
+not only by increasing temperature but also by modest in-plane magnetic fields.
+The analysis shows that giant negative magnetoresistance cannot be explained by
+existing theories considering interaction-induced or disorder-induced
+corrections.",1201.5679v1
+2012-04-27,Observation of a Free-Shercliff-Layer Instability in Cylindrical Geometry,"We report on observations of a free-Shercliff-layer instability in a
+Taylor-Couette experiment using a liquid metal over a wide range of Reynolds
+numbers, $Re\sim 10^3-10^6$. The free Shercliff layer is formed by imposing a
+sufficiently strong axial magnetic field across a pair of differentially
+rotating axial endcap rings. This layer is destabilized by a hydrodynamic
+Kelvin-Helmholtz-type instability, characterized by velocity fluctuations in
+the $r-\theta$ plane. The instability appears with an Elsasser number above
+unity, and saturates with an azimuthal mode number $m$ which increases with the
+Elsasser number. Measurements of the structure agree well with 2D global linear
+mode analyses and 3D global nonlinear simulations. These observations have
+implications for a range of rotating MHD systems in which similar shear layers
+may be produced.",1204.6339v1
+2012-05-14,Isotope shifts and hyperfine structure of the Fe I 373.7 nm resonance line,"We report measurements of the isotope shifts of the 3d6 4s2 a 5D3 - 3d6 4s4p
+z 5F4o FeI resonance line at 373.7 nm between all four stable isotopes 54Fe,
+56Fe, 57Fe and 58Fe, as well as the complete hyperfine structure of that line
+for 57Fe, the only stable isotope having a non-zero nuclear spin. The field and
+specific mass shift coefficients of the transition have been derived from the
+data, as well as the experimental value for the hyperfine structure magnetic
+dipole coupling constant A of the excited state of the transition in 57Fe :
+A(3d6 4s4p z 5F4o) = 68.21(69) MHz. The measurements were carried out by means
+of high-resolution Doppler-free laser saturated absorption spectroscopy in a
+Fe-Ar hollow cathode discharge cell using both natural and enriched iron
+samples. The measured isotope shifts and hyperfine constants are reported with
+uncertainties at the percent level.",1205.3146v1
+2012-06-01,Deep Spin-Glass Hysteresis Area Collapse and Scaling in the $d=3$ $\pm J$ Ising Model,"We investigate the dissipative loss in the $\pm J$ Ising spin glass in three
+dimensions through the scaling of the hysteresis area, for a maximum magnetic
+field that is equal to the saturation field. We perform a systematic analysis
+for the whole range of the bond randomness as a function of the sweep rate, by
+means of frustration-preserving hard-spin mean field theory. Data collapse
+within the entirety of the spin-glass phase driven adiabatically (i.e.,
+infinitely-slow field variation) is found, revealing a power-law scaling of the
+hysteresis area as a function of the antiferromagnetic bond fraction and the
+temperature. Two dynamic regimes separated by a threshold frequency $\omega_c$
+characterize the dependence on the sweep rate of the oscillating field. For
+$\omega < \omega_c$, the hysteresis area is equal to its value in the adiabatic
+limit $\omega = 0$, while for $\omega > \omega_c$ it increases with the
+frequency through another randomness-dependent power law.",1206.0230v2
+2012-06-04,Coarse-grained spin density-functional theory: infinite-volume limit via the hyperfinite,"Coarse-grained spin density functional theory (SDFT) is a version of SDFT
+which works with number/spin densities specified to a limited resolution ---
+averages over cells of a regular spatial partition --- and external potentials
+constant on the cells. This coarse-grained setting facilitates a rigorous
+investigation of the mathematical foundations which goes well beyond what is
+currently possible in the conventional formualation. Problems of existence,
+uniqueness and regularity of representing potentials in the coarse-grained SDFT
+setting are here studied using techniques of (Robinsonian) nonstandard
+analysis. Every density which is nowhere spin-saturated is V-representable, and
+the set of representing potentials is the functional derivative, in an
+appropriate generalized sense, of the Lieb interal energy functional.
+Quasi-continuity and closure properties of the set-valued representing
+potentials map are also established. The extent of possible non-uniqueness is
+similar to that found in non-rigorous studies of the conventional theory,
+namely non-uniqueness can occur for states of collinear magnetization which are
+eigenstates of $S_z$.",1206.0769v2
+2012-07-19,Dipolar order by disorder in the classical Heisenberg antiferromagnet on the kagome lattice,"Ever since the experiments which founded the field of highly frustrated
+magnetism, the kagome Heisenberg antiferromagnet has been the archetypical
+setting for the study of fluctuation induced exotic ordering. To this day the
+nature of its classical low-temperature state has remained a mystery: the
+non-linear nature of the fluctuations around the exponentially numerous
+harmonically degenerate ground states has not permitted a controlled theory,
+while its complex energy landscape has precluded numerical simulations at low
+temperature. Here we present an efficient Monte Carlo algorithm which removes
+the latter obstacle. Our simulations detect a low-temperature regime in which
+correlations saturate at a remarkably small value. Feeding these results into
+an effective model and analyzing the results in the framework of an appropriate
+field theory implies the presence of long-range dipolar spin order with a
+tripled unit cell.",1207.4752v2
+2012-08-08,Evidence for two-gap superconductivity in the non-centrosymmetric compound LaNiC$_2$,"We study the superconducting properties of the non-centrosymmetric compound
+LaNiC$_2$ by measuring the London penetration depth $\Delta \lambda (T)$, the
+specific heat $C(T,B)$ and the electrical resistivity $\rho (T,B)$. Both
+$\Delta\lambda (T)$ and the electronic specific heat $C_e(T)$ exhibit
+exponential behavior at low temperatures and can be described in terms of a
+phenomenological two-gap BCS model. The residual Sommerfeld coefficient in the
+superconducting state, $\gamma_0(B)$, shows a fast increase at low fields and
+then an eventual saturation with increasing magnetic field. A pronounced upturn
+curvature is observed in the upper critical field $B_{c2}(T)$ near $T_{c}$. All
+the experimental observations support the existence of two-gap
+superconductivity in LaNiC$_2$.",1208.1596v1
+2012-09-29,Nonsaturating Dephasing Time at Low Temperature in an Open Quantum Dot,"We report measurements of the electron dephasing time extracted from the weak
+localization (WL) correction to the average conductance in an open AlGaAs/GaAs
+quantum dot from 1 K to 13 mK. In agreement with theoretical predictions but in
+contrast with previous measurements in quantum dots, the extracted dephasing
+time does not saturate at the lowest temperatures. We find that the dephasing
+time follows an inverse linear power law with temperature. We determine that
+the extraction of the dephasing time from WL is applicable down to our lowest
+temperatures, but extraction from finite magnetic field conductance
+fluctuations is complicated by charging effects below 13 mK.",1210.0087v1
+2012-10-02,Graphene as a reversible spin manipulator of molecular magnets,"One of the primary objectives in molecular nano-spintronics is to manipulate
+the spin states of organic molecules with a d-electron center, by suitable
+external means. In this letter, we demonstrate by first principles density
+functional calculations, as well as second order perturbation thoery, that a
+strain induced change of the spin state, from S=1 $\to$ S=2, takes place for an
+iron porphyrin (FeP) molecule deposited at a divacancy site in a graphene
+lattice. The process is reversible in a sense that the application of tensile
+or compressive strains in the graphene lattice can stabilize FeP in different
+spin states, each with a unique saturation moment and easy axis orientation.
+The effect is brought about by a change in Fe-N bond length in FeP, which
+influences the molecular level diagram as well as the interaction between the C
+atoms of the graphene layer and the molecular orbitals of FeP.",1210.0666v1
+2012-11-20,Bond Randomness Induced Magnon Decoherence in a Spin-1/2 Ladder Compound,"We have used a combination of neutron resonant spin-echo and triple-axis
+spectroscopies to determine the energy and linewidth of the magnon resonance in
+IPA-Cu(Cl$_{0.95}$Br$_{0.05}$)$_3$, a model spin-1/2 ladder antiferromagnet
+where Br substitution induces bond randomness. We find that the bond defects
+induce a blueshift, $\delta \Delta$, and broadening, $\delta \Gamma$, of the
+magnon gap excitation compared to the pure compound. At temperatures exceeding
+the energy scale of the inter-ladder exchange interactions, $\delta \Delta$ and
+$\delta \Gamma$ are temperature independent within the experimental error, in
+agreement with Matthiessen's rule according to which magnon-defect scattering
+yields a temperature independent contribution to the magnon mean free path.
+Upon cooling, $\delta \Delta$ and $\delta \Gamma$ become temperature dependent
+and saturate at values lower than those observed at higher temperature,
+consistent with the crossover from one-dimensional to two-dimensional spin
+correlations with decreasing temperature previously observed in pure
+IPA-CuCl$_3$. These results indicate limitations in the applicability of
+Matthiessen's rule for magnon scattering in low-dimensional magnets.",1211.4741v1
+2012-12-04,Three Dimensional Structure of Relativistic Jet Formation,"Using high resolution adaptive mesh refinement simulations in 3D, we
+investigate the formation of relativistic jets from rotating magnetospheres.
+Here, we focus on the development of non-axisymmetric modes due to internal and
+external perturbations to the jet. These originate either from injection of
+perturbations with the flow or from a clumpy external medium. In the helical
+field geometry of the accelerating jet, the m=1 to m=5 modes are analyzed and
+found to saturate at a height of \sim 20 inner disk radii. We also discuss a
+means to control artificial amplification of m = 4 noise in the cartesian
+simulation geometry. Strong perturbations due to an in-homogeneous ambient
+medium lead to flow configurations with increased magnetic pitch and thus
+indicate a self-stabilization of the jet formation mechanism.",1212.0676v1
+2012-12-18,Photoluminescence studies of Zeeman effect in type-II InSb/InAs nanostructures,"Electron spin polarization up to 100% has been observed in type-II narrow-gap
+heterostructures with ultrathin InSb insertions in an InAs matrix via
+investigation of circularly polarized photoluminescence in an external magnetic
+field applied in Faraday geometry. The polarization degree decreases
+drastically, changes its sign, and saturates finally at the value of 10% in the
+limit of either high temperature or strong excitation. The observed effect is
+explained in terms of strong Zeeman splitting of the electron conduction band
+in the InAs matrix and a heavy-hole state confined in the InSb insertion, due
+to a large intrinsic g-factor of both types of carriers. The hole ground state
+in a monolayer scale InSb/InAs quantum well, calculated using a tight-binding
+approach, fits well the observed emission wavelength. Temperature dependence of
+the emission polarization degree is in good agreement with its theoretical
+estimation performed in the framework of a proposed phenomenological model.",1212.4341v1
+2012-12-28,Magneto-resistance up to 60 Tesla in Topological Insulator Bi2Te3 Thin Films,"We report magneto-transport studies of topological insulator Bi_{2}Te_{3}
+thin films grown by pulsed laser deposition. A non-saturating linear-like
+magneto-resistance (MR) is observed at low temperatures in the magnetic field
+range from a few Tesla up to 60 Tesla. We demonstrate that the strong
+linear-like MR at high field can be well understood as the weak
+antilocalization phenomena described by Hikami-Larkin-Nagaoka theory. Our
+analysis suggests that in our system, a topological insulator, the elastic
+scattering time can be longer than the spin-orbit scattering time. We briefly
+discuss our results in the context of Dirac Fermion physics and 'quantum linear
+magnetoresistance'.",1212.6464v1
+2013-01-10,Evolution of solar-type stellar wind,"By extending our self-consistent MHD simulations for the solar wind, we study
+the evolution of stellar winds of solar-type stars from early main sequence
+stage to red giant phase. Young solar-type stars are active and the mass loss
+rates are larger by up to ~ 100 times than that of the present-day sun. We
+investigate how the stellar wind is affected when the magnetic field strength
+and fluctuation amplitude at the photosphere increase. While the mass loss rate
+sensitively depends on the input energy from the surface because of the global
+instability related to the reflection and nonlinear dissipation of Alfven
+waves, it saturates at ~ 100 times because most of the energy is used up for
+the radiative losses rather than the kinetic energy of the wind. After the end
+of the main sequence phase when the stellar radius expands by ~ 10 times, the
+steady hot corona with temperature $10^6$ K, suddenly disappears. Chromospheric
+materials, with hot bubbles embedded owing to thermal instability, directly
+stream out; the red giant wind is not a steady stream but structured outflow.",1301.2359v1
+2013-04-25,Universal corrections to the entanglement entropy in gapped quantum spin chains: a numerical study,"We carry out a numerical study of the bi-partite entanglement entropy in the
+gapped regime of two paradigmatic quantum spin chain models: the Ising chain in
+an external magnetic field and the anti-ferromagnetic XXZ model. The universal
+scaling limit of these models is described by the massive Ising field theory
+and the SU(2)-Thirring (sine-Gordon) model, respectively. We may therefore
+exploit quantum field theoretical results to predict the behaviour of the
+entropy. We numerically confirm that, in the scaling limit, corrections to the
+saturation of the entropy at large region size are proportional to the Bessel
+function K0(2mr) where m is a mass scale (the inverse correlation length) and r
+the length of the region under consideration. The proportionality constant is
+simply related to the number of particle types in the universal spectrum. This
+was originally predicted in publications involving two of the current authors
+for two-dimensional quantum field theories. Away from the universal region our
+numerics suggest an entropic behaviour following quite closely the quantum
+field theory prediction, except for extra dependencies on the correlation
+length.",1304.6874v1
+2013-05-07,Micromagnetic modelling of anisotropic damping in ferromagnet,"We report a numerical implementation of the Landau-Lifshitz-Baryakhtar
+theory, which dictates that the micromagnetic relaxation term obeys the
+symmetry of the magnetic crystal, i. e. replacing the single intrinsic damping
+constant with a tensor of corresponding symmetry. The effect of anisotropic
+relaxation is studied in thin saturated ferromagnetic disk and ellipse with and
+without uniaxial magneto-crystalline anisotropy. We investigate the angular
+dependency of the linewidth of magnonic resonances with respect to the given
+structure of the relaxation tensor. The simulations suggest that the anisotropy
+of the magnonic linewidth is determined by only two factors: the projection of
+the relaxation tensor onto the plane of precession and the ellipticity of the
+later.",1305.1641v2
+2013-05-15,Competing orders in the 2D half-filled SU(2N) Hubbard model through the pinning field quantum Monte-Carlo simulations,"We non-perturbatively investigate the ground state magnetic properties of the
+2D half-filled SU($2N$) Hubbard model in the square lattice by using the
+projector determinant quantum Monte Carlo simulations combined with the method
+of local pinning fields. Long-range Neel orders are found for both the SU(4)
+and SU(6) cases at small and intermediate values of $U$. In both cases, the
+long-range Neel moments exhibit non-monotonic behavior with respect to $U$,
+which first grow and then drop as $U$ increases. This result is fundamentally
+different from the SU(2) case in which the Neel moments increase monotonically
+and saturate. In the SU(6) case, a transition to the columnar dimer phase is
+found in the strong interaction regime.",1305.3571v3
+2013-05-25,On the definition and interpretation of a static quark anti-quark potential in the colour-adjoint channel,"We study possibilities to define a static quark anti-quark pair in a
+colour-adjoint orientation based on Wilson loops with generator insertions,
+using both lattice QCD and leading order perturbation theory in various gauges.
+Non-perturbatively, the only way to obtain non-zero results while maintaining
+positivity of the Hamiltonian is by some form of temporal gauge. In this case
+the correlator is equivalent to a gauge invariant correlation function of a
+static quark anti-quark pair and a static adjoint quark, the resulting
+three-point potential is attractive. Saturating open colour indices with colour
+magnetic fields instead also leads to a gauge invariant correlator. However
+this object is found to couple to the singlet sector only. There appears to be
+no lattice observable that reproduces the repulsive adjoint potential predicted
+by perturbation theory in Lorenz or Coulomb gauges.",1305.5957v1
+2013-06-18,Interaction of Ultra Relativistic e- e+ Fireball Beam with Plasma,"Ab initio simulations of the propagation in a plasma of a soon to be
+available relativistic electron-positron beam or fireball beam provide an
+effective mean for the study of microphysics relevant to astrophysical
+scenarios. We show that the current filamentation instability associated with
+some of these scenarios reaches saturation after only 10 cm of propagation in a
+typical laboratory plasma with a density 10^17/cc. The different regimes of the
+instability, from the purely transverse to the mixed mode filamentation, can be
+accessed by varying the background plasma density. The instability generates
+large local plasma gradients, intense transverse magnetic fields, and enhanced
+emission of radiation. We suggest that these effects may be observed
+experimentally for the first time.",1306.4380v2
+2013-07-11,Large Linear Magnetoresistance and Shubnikov-de Hass Oscillations in Single Crystals of YPdBi Heusler Topological Insulators,"We report the observation of a large linear magnetoresistance (MR) and
+Shubnikov-de Hass (SdH) quantum oscillations in single crystals of YPdBi
+Heusler topological insulators. Owning to the successfully obtained the
+high-quality YPdBi single crystals, large non-saturating linear MR of as high
+as 350% at 5K and over 120% at 300 K under a moderate magnetic field of 7 T is
+observed. In addition to the large, field-linear MR, the samples exhibit
+pronounced SdH quantum oscillations at low temperature. Analysis of the SdH
+data manifests that the high-mobility bulk electron carriers dominate the
+magnetotransport and are responsible for the observed large linear MR in YPdBi
+crystals. These findings imply that the Heusler-based topological insulators
+have superiorities for investigating the novel quantum transport properties and
+developing the potential applications.",1307.3022v1
+2013-07-23,Honeycomb Heisenberg Spin Ladder: Unusual Ground State and Thermodynamic Properties,"The unusual ground state and thermodynamic properties of spin-1/2 two-leg
+honeycomb (HC) spin ladder are systematically studied by jointly utilizing
+various analytical and numerical methods. The HC spin ladder is found to
+exhibit behaviors dramatically different from those of the conventional square
+spin ladder. A strong relevant term nJ and a half saturation magnetization
+plateau that can be attributed to the formation of diluted dimer states are
+observed in the HC ladder, both of which are absent in the square ladder. The
+ground state phase diagram of the HC spin ladder is identified, and the
+thermodynamic properties of the specific heat and susceptibility for different
+couplings are thoroughly explored, where two kinds of excitations are unveiled.
+The distinct Wilson ratios for both spin ladders at the lower critical fields
+are also obtained. Our calculated result is well fitted to the experimental
+data of the two-leg HC spin ladder compound [Cu2L1(N3)4]n.",1307.5945v1
+2013-09-03,Criticality and quenched disorder: rare regions vs. Harris criterion,"We employ scaling arguments and optimal fluctuation theory to establish a
+general relation between quantum Griffiths singularities and the Harris
+criterion for quantum phase transitions in disordered systems. If a clean
+critical point violates the Harris criterion, it is destabilized by weak
+disorder. At the same time, the Griffiths dynamical exponent $z'$ diverges upon
+approaching the transition, suggesting unconventional critical behavior. In
+contrast, if the Harris criterion is fulfilled, power-law Griffiths
+singularities can coexist with clean critical behavior but $z'$ saturates at a
+finite value. We present applications of our theory to a variety of systems
+including quantum spin chains, classical reaction-diffusion systems and
+metallic magnets; and we discuss modifications for transitions above the upper
+critical dimension. Based on these results we propose a unified classification
+of phase transitions in disordered systems.",1309.0753v2
+2013-09-17,Heteroepitaxial Growth and Multiferroic Properties of Mn-doped BiFeO3 films on SrTiO3 buffered III-V Semiconductor GaAs,"Epitaxial Mn-doped BiFeO3 (MBFO) thin films were grown on GaAs (001)
+substrate with SrTiO3 (STO) buffer layer by pulsed laser deposition. X-ray
+diffraction results demonstrate that the films show pure (00l) orientation, and
+MBFO(100)//STO(100), whereas STO (100)//GaAs (110). Piezoresponse force
+microscopy images and polarization versus electric field loops indicate that
+the MBFO films grown on GaAs have an effective ferroelectric switching. The
+MBFO films exhibit good ferroelectric behavior (2Pr ~ 92 {\mu}C/cm2 and 2EC ~
+372 kV/cm). Ferromagnetic property with saturated magnetization of 6.5 emu/cm3
+and coercive field of about 123 Oe is also found in the heterostructure at room
+temperature.",1309.4222v1
+2013-10-03,Exploiting neutron-rich radioactive ion beams to constrain the symmetry energy,"The Modular Neutron Array (MoNA) and 4 Tm Sweeper magnet were used to measure
+the free neutrons and heavy charged particles from the radioactive ion beam
+induced 32Mg + 9Be reaction. The fragmentation reaction was simulated with the
+Constrained Molecular Dynamics model(CoMD), which demonstrated that the <N/Z>
+of the heavy fragments and free neutron multiplicities were observables
+sensitive to the density dependence of the symmetry energy at sub-saturation
+densities. Through comparison of these simulations with the experimental data
+constraints on the density dependence of the symmetry energy were extracted.
+The advantage of radioactive ion beams as a probe of the symmetry energy is
+demonstrated through examination of CoMD calculations for stable and
+radioactive beam induced reactions.",1310.0990v1
+2013-10-24,Uncertainty relation for focal spots in light beams,"Uncertainty relations for light pulses found in [Phys. Rev. A {\bf 86},
+022118 (2012)] were derived in the three-dimensional case which emphasized the
+localization in a volume. Here we derive the uncertainty relation for light
+beams in the two-dimensional plane perpendicular to the direction of the beam
+propagation which is more interesting for realistic beams. This uncertainty
+relation connects the area of the focal spot with the spectrum of transverse
+photon momenta. The shape of the beam that saturates the uncertainty relation
+is very close to a Gaussian. The directions of the electric and magnetic field
+vectors are those of the circularly polarized plane wave. Our uncertainty
+relation for the focal spot is quite general but we were able to determine the
+value of the lower bound only for beams made of many photons.",1310.6570v1
+2013-11-18,Vortical field amplification and particle acceleration at rippled shocks,"Supernova Remnants (SNRs) shocks are believed to accelerate charged particles
+and to generate strong turbulence in the post-shock flow. From high-energy
+observations in the past decade, a magnetic field at SNR shocks largely
+exceeding the shock-compressed interstellar field has been inferred. We outline
+how such a field amplification results from a small-scale dynamo process
+downstream of the shock, providing an explicit expression for the turbulence
+back-reaction to the fluid whirling. The spatial scale of the $X-$ray rims and
+the short time-variability can be obtained by using reasonable parameters for
+the interstellar turbulence. We show that such a vortical field saturation is
+faster than the acceleration time of the synchrotron emitting energetic
+electrons.",1311.5207v1
+2013-11-25,Anomalous Viscosity of the Quark-Gluon Plasma,"The shear viscosity of the quark-gluon plasma is predicted to be lower than
+the collisional viscosity for weak coupling. The estimated ratio of the shear
+viscosity to entropy density is rather close to the ratio calculated by N = 4
+super Yang-Mills theory for strong coupling, which indicates that the
+quark-gluon plasma might be strongly coupled. However, in presence of momentum
+anisotropy, the Weibel instability can arise and drive the turbulent transport.
+Shear viscosity can be lowered by enhanced collisionality due to turbulence,
+but the decorrelation time and its relation to underlying dynamics and
+color-magnetic fields have not been calculated self-consistently. In this
+paper, we use resonance broadening theory for strong turbulence to calculate
+the anomalous viscosity of the quark-gluon plasma for nonequilibrium. For
+saturated Weibel instability, we estimate the scalings of the decorrelation
+rate and viscosity and compare these with collisional transport. This
+calculation yields an explicit connection between the underlying momentum space
+anisotropy and the viscosity anomaly.",1311.6347v2
+2014-01-16,Structure of longitudinal chromomagnetic fields in high energy collisions,"We compute expectation values of spatial Wilson loops in the forward light
+cone of high-energy collisions. We consider ensembles of gauge field
+configurations generated from a classical Gaussian effective action as well as
+solutions of high-energy renormalization group evolution with fixed and running
+coupling. The initial fields correspond to a color field condensate exhibiting
+domain-like structure over distance scales of order the saturation scale. At
+later times universal scaling emerges at large distances for all ensembles,
+with a nontrivial critical exponent. Finally, we compare the results for the
+Wilson loop to the two-point correlator of magnetic fields.",1401.4124v2
+2014-03-19,Low anisotropy of the upper critical field in a strongly anisotropic layered cuprate: Evidence for paramagnetically limited superconductivity,"We study angular-dependent magnetoresistance in a low $T_c$ layered cuprate
+Bi$_{2.15}$Sr$_{1.9}$CuO$_{6+\delta}$. The low $T_c$ ~ 4 K allows complete
+suppression of superconductivity by modest magnetic fields and facilitate
+accurate analysis of the upper critical field $H_{c2}$. We observe an universal
+exponential decay of fluctuation conductivity in a broad range of temperatures
+above $T_c$ and propose a new method for extraction of $H_{c2}(T)$ from the
+scaling analysis of the fluctuation conductivity at $T>T_c$. Our main result is
+observation of a surprisingly low $H_{c2}$ anisotropy ~ 2, which is much
+smaller than the effective mass anisotropy of the material ~ 300. We show that
+the anisotropy is decreasing with increasing field and saturates at a small
+value when the field reaches the paramagnetic limit. We argue that the dramatic
+discrepancy of high field and low field anisotropies is a clear evidence for
+paramagnetically limited superconductivity.",1403.4817v2
+2014-06-03,Muon spin rotation and relaxation in Pr$_{1-x}$Nd$_x$Os$_4$Sb$_{12}$: Paramagnetic states,"Positive-muon ($\mu^+$) Knight shifts have been measured in the paramagnetic
+states of Pr$_{1-x}$Nd$_x$Os$_4$Sb$_{12}$ alloys, where $x =$ 0, 0.25, 0.45,
+0.50, 0.55, 0.75, and 1.00. In Pr-substituted NdOs$_4$Sb$_{12}$ ($x \le$ 0.75),
+but not in NdOs$_4$Sb$_{12}$, Clogston-Jaccarino plots of $\mu^+$ Knight
+shift~$K$ versus magnetic susceptibility~$\chi$ exhibit an anomalous saturation
+of $K(\chi)$ at $\sim-$0.5% for large susceptibilities (low temperatures),
+indicating a reduction of the coupling strength between $\mu^+$ spins and $4f$
+paramagnetism for temperatures $\lesssim$ 15~K. We speculate that itinerant
+Pr$^{3+}$ quadrupolar excitations, invoked to mediate the superconducting
+Cooper-pair interaction, might modify the $\mu^+$-$4f$ ion indirect spin-spin
+interaction.",1406.0903v1
+2014-08-28,Statistical simulation of the magnetorotational dynamo,"Turbulence and dynamo induced by the magnetorotational instability (MRI) are
+analyzed using quasi-linear statistical simulation methods. It is found that
+homogenous turbulence is unstable to a large scale dynamo instability, which
+saturates to an inhomogenous equilibrium with a strong dependence on the
+magnetic Prandtl number (Pm). Despite its enormously reduced nonlinearity, the
+dependence of the angular momentum transport on Pm in the quasi-linear model is
+qualitatively similar to that of nonlinear MRI turbulence. This indicates that
+recent convergence problems may be related to large scale dynamo and suggests
+how dramatically simplified models may be used to gain insight into the
+astrophysically relevant regimes of very low or high Pm.",1408.6793v2
+2014-09-06,Crossover between Fermi liquid and non-Fermi liquid behavior in the non-centrosymmetric compound Yb$_2$Ni$_{12}$P$_7$,"A crossover from a non-Fermi liquid to a Fermi liquid phase in
+Yb$_2$Ni$_{12}$P$_7$ is observed by analyzing electrical resistivity $\rho(T)$,
+magnetic susceptibility $\chi(T)$, specific heat $C(T)$, and thermoelectric
+power $S(T)$ measurements. The electronic contribution to specific heat,
+$C_{e}(T)$, behaves as $C_{e}(T)/T \sim -\ln(T)$ for 5 K $< T <$ 15 K, which is
+consistent with non-Fermi liquid behavior. Below $T \sim$ 4 K, the upturn in
+$C_{e}(T)/T$ begins to saturate, suggesting that the system crosses over into a
+Fermi-liquid ground state. This is consistent with robust $\rho(T) - \rho_0 =
+AT^2$ behavior below $T \sim$ 4 K, with the power-law exponent becoming
+sub-quadratic for $T >$ 4 K. A crossover between Fermi-liquid and non-Fermi
+liquid behavior suggests that Yb$_2$Ni$_{12}$P$_7$ is in close proximity to a
+quantum critical point, in agreement with results from recent measurements of
+this compound under applied pressure.",1409.2066v1
+2014-10-15,Beam-beam effects in BEPCII,"We first introduce the design parameters of the Beijing Electron-Positron
+Collider II (BEPCII) and the simulation study of beam-beam effects during the
+design process of the machine. The main advances since 2007 are briefly
+introduced and reviewed. The longitudinal feedback system was installed to
+suppress the coupled bunch instability in January 2010. The horizontal tune
+decreased from 6.53 to 6.508 during the course of data taken in December, 2010.
+The saturation of the beam-beam parameter was found in 2011, and the vacuum
+chambers and magnets near the north crossing point were moved 15 cm in order to
+mitigate the long range beam-beam interaction. At the beginning of 2013, the
+beam-beam parameter achieved 0.04 with the new lower $\alpha_{p}$ lattice and
+the peak luminosity achieved 7 x 10$^{32}$ cm$^{-2}$ s$^{-1}$.",1410.4057v1
+2014-10-28,Universal Braess paradox in open quantum dots,"We present analytical and numerical results that demonstrate the presence of
+the Braess paradox in chaotic quantum dots. The paradox that we identify,
+originally perceived in classical networks, shows that the addition of more
+capacity to the network can suppress the current flow in the universal regime.
+We investigate the weak localization term, showing that it presents the paradox
+encoded in a saturation minimum of the conductance, under the presence of
+hyperflow in the external leads. In addition, we demonstrate that the weak
+localization suffers a transition signal depending on the overcapacity lead and
+presents an echo on the magnetic crossover before going to zero due to the full
+time-reversal symmetry breaking.We also show that the quantum interference
+contribution can dominate the Ohm term in the presence of constrictions and
+that the corresponding Fano factor engenders an anomalous behavior",1410.7750v1
+2014-10-31,Dissociative Adsorption of Molecules on Graphene and Silicene,"We study the interaction of H$_2$, O$_2$, CO, H$_2$O and OH molecules with
+the vacancy defects of graphene and silicene. Atoms around the bare vacancy
+reconstruct and specific chemically active sites are created. While H$_2$,
+O$_2$ and CO remain intact on both pristine graphene and silicene, these
+molecules can dissociate when they are placed at the close proximity of these
+chemically active sites and nucleate centers for the hydrogenation and
+oxygenation. Saturation of the dangling bonds at the defect sites by
+constituent atoms of dissociated molecules gives rise to significant
+modification of electronic and magnetic properties. We analyzed the mechanism
+of the dissociation and revealed a concerted action of surrounding host atoms
+together with dissociated molecules to lower the energy barrier needed for
+dissociation. The dissociations of H$_2$O and OH are hindered by high energy
+barriers. Our study suggests that graphene and silicene can be functionalized
+by creating meshes of single vacancy, where specific molecules can dissociate,
+while some other molecules can be pinned.",1410.8730v1
+2014-12-02,Dynamical quenching with non-local alpha and downward pumping,"In light of new results, the one-dimensional mean-field dynamo model of
+Brandenburg & Kapyla (2007) with dynamical quenching and a nonlocal
+Babcock-Leighton alpha effect is re-examined for the solar dynamo. We extend
+the one-dimensional model to include the effects of turbulent downward pumping
+(Kitchatinov & Olemskoy 2011), and to combine dynamical quenching with shear.
+We use both the conventional dynamical quenching model of Kleeorin & Ruzmaikin
+(1982) and the alternate one of Hubbard & Brandenburg (2011), and confirm that
+with varying levels of non-locality in the alpha effect, and possibly shear as
+well, the saturation field strength can be independent of the magnetic Reynolds
+number.",1412.0997v1
+2014-12-29,Perfect charge compensation in WTe2 for the extraordinary magnetoresistance: From bulk to monolayer,"The electronic structure of WTe2 bulk and layers are investigated by using
+the first principles calculations. The perfect electron-hole (n-p) charge
+compensation and high carrier mobilities are found in WTe2 bulk, which may
+result in the large and non-saturating magnetoresistance (MR) observed very
+recently in the experiment [Ali et al., Nature 514, 205 (2014)]. The monolayer
+and bilayer of WTe2 preserve the semimetallic property, with the equal hole and
+electron carrier concentrations. Moreover, the very high carrier mobilities are
+also found in WTe2 monolayer, indicating that the WTe2 monolayer would have the
+same extraordinary MR effect as the bulk, which could have promising
+applications in nanostructured magnetic devices.",1412.8335v1
+2015-01-29,Resolution of hyperfine transitions in metastable 83Kr using Electromagnetically Induced Transparency,"Narrow linewidth signals of Electromagnetically Induced Transparency (EIT) in
+the metastable 83Kr have been observed for the first time. Various hyperfine
+transitions in 4p55s[3/2]2 to 4p55p[5/2]3 manifolds of 83Kr have been
+identified through the experimentally observed EIT signals. Some unresolved or
+poorly resolved hyperfine transitions in saturated absorption spectroscopy
+(SAS) are clearly resolved in the present work. Using the spectral separation
+of these EIT identified hyperfine transitions, the magnetic hyperfine constant
+(A) and the electric quadrupole hyperfine constant (B) are determined with
+improved accuracy for 4p55s[3/2]2 and 4p55p[5/2]3 manifolds.",1501.07381v2
+2015-02-11,High Field Ultrasound Measurements in UPt3 and the Single Energy Scale Model of Metamagnetism,"We report longitudinal ultrasound velocity measurements for magnetic fields
+up to 33 T applied parallel to the a-axis of the heavy electron compound
+UPt$_{3}$. A characteristic dip in the sound velocity at the metamagnetic
+critical field, $H_{c}=20$ T, reported in earlier work is reproduced and shown
+to be independent of temperature at very low temperatures. We show that the
+single energy scale model (B.S. Shivaram et al., Phys. Rev. B89, 241107(R),
+2014) captures the observed key features of the field dependence in the sound
+velocity shift, $\delta v_{s}$. The shift $\delta v_{s}$ at $H_{c}$ is found to
+be inversely dependent on temperature above 3\thinspace K and assumes a fixed
+value at low T. This saturation in $\delta v_{s}$ below 3 K is accounted for by
+level broadening of the Uranium spin states.",1502.03412v1
+2015-02-16,Anisotropic Magnetotransport and Exotic Longitudinal Linear Magnetoresistance in WTe2 Crystals,"WTe2 semimetal, as a typical layered transition-metal dichalcogenide, has
+recently attracted much attention due to the extremely large, non-saturating
+parabolic magnetoresistance in perpendicular field. Here, we report a
+systematic study of the angular dependence of the magnetoresistance in WTe2
+single crystal. The violation of the Kohler rule and a significant anisotropic
+magnetotransport behavior in different magnetic field directions are observed.
+Surprisingly, when the applied field is parallel to the tungsten chains of
+WTe2, an exotic large longitudinal linear magnetoresistance as high as 1200% at
+15 T and 2 K is identified. Violation of the Kohler rule in transverse
+magnetoresistance can be understood based on a dual effect of the excitons
+formation and thermal activation, while large longitudinal linear
+magnetoresistance reflects perfectly the scattering and nesting of quasi-1D
+nature of this balanced hole-electron system. Our work will stimulate studies
+of such double-carrier correlated material and corresponding quantum physics.",1502.04465v1
+2015-03-25,Magnetotransport of single crystalline NbAs,"We report transport measurement in zero and applied magnetic field on a
+single crystal of NbAs. Transverse and longitudinal magnetoresistance in the
+plane of this tetragonal structure does not saturate up to 9 T. In the
+transverse configuration ($H \parallel c$, $I \perp c$) it is 230,000 \% at 2
+K. The Hall coefficient changes sign from hole-like at room temperature to
+electron-like below $\sim$ 150 K. The electron carrier density and mobility
+calculated at 2 K based on a single band approximation are 1.8 x 10$^{19}$
+cm$^{-3}$ and 3.5 x 10$^{5}$ cm$^2$/Vs, respectively. These values are similar
+to reported values for TaAs and NbP, and further emphasize that this class of
+noncentrosymmetric, transition-metal monopnictides is a promising family to
+explore the properties of Weyl semimetals and the consequences of their novel
+electronic structure.",1503.07571v1
+2015-03-27,Dynamic nuclear polarization and the paradox of Quantum Thermalization,"Dynamic Nuclear Polarization (DNP) is to date the most effective technique to
+increase the nuclear polarization up to a factor $100,000$ opening disruptive
+perspectives for medical applications. In DNP, the nuclear spins are driven to
+an - out of equilibrium - hyperpolarized state by microwave saturation of the
+electron spins in interaction with them. Here we show that the electron dipolar
+interactions compete with the local magnetic fields resulting in two distinct
+dynamical phases: for strong interactions the electron spins equilibrate to an
+extremely low effective temperature that boosts DNP efficiency. For weak
+interaction this spin temperature is not defined and the polarization profile
+has an 'hole burning' shape characteristic of the non interacting case. The
+study of the many-body eigenstates reveals that these two phases are intimately
+related to the problem of thermalization in closed quantum systems where
+breaking of ergodicity is expected varying the strength of the interactions.",1503.08181v2
+2015-04-07,Multiple Fermi pockets revealed by Shubnikov-de Haas oscillations in WTe2,"We use magneto-transport measurements to investigate the electronic structure
+of WTe2 single crystals. A non-saturating and parabolic magnetoresistance is
+observed in the temperature range between 2.5 to 200 K and magnetic fields up
+to 8 T. Shubnikov - de Haas oscillations with beating patterns are observed.
+The fast Fourier transform of the SdH oscillations reveals three oscillation
+frequencies, corresponding to three pairs of Fermi pockets with comparable
+effective masses , m* ~ 0.31 me. By fitting the Hall resistivity, we infer the
+presence of one pair of electron pockets and two pairs of hole pockets,
+together with nearly perfect compensation of the electron-hole carrier
+concentration. These magnetotransport measurements reveal the complex
+electronic structure in WTe2, explaining the nonsaturating magnetoresistance.",1504.01460v1
+2015-04-27,Fricke S-duality in CHL models,"We consider four dimensional CHL models with sixteen spacetime
+supersymmetries obtained from orbifolds of type IIA superstring on K3 x T^2 by
+a Z_N symmetry acting (possibly) non-geometrically on K3. We show that most of
+these models (in particular, for geometric symmetries) are self-dual under a
+weak-strong duality acting on the heterotic axio-dilaton modulus S by a ""Fricke
+involution"" S --> -1/NS. This is a novel symmetry of CHL models that lies
+outside of the standard SL(2,Z)-symmetry of the parent theory, heterotic
+strings on T^6. For self-dual models this implies that the lattice of purely
+electric charges is N-modular, i.e. isometric to its dual up to a rescaling of
+its quadratic form by N. We verify this prediction by determining the lattices
+of electric and magnetic charges in all relevant examples. We also calculate
+certain BPS-saturated couplings and verify that they are invariant under the
+Fricke S-duality. For CHL models that are not self-dual, the strong coupling
+limit is dual to type IIA compactified on T^6/Z_N, for some Z_N-symmetry
+preserving half of the spacetime supersymmetries.",1504.07260v3
+2015-06-18,Short-period stellar activity cycles with Kepler photometry,"We study the short-periodic component of stellar activity with a cycle
+periods Pcyc up to 1000 days using the Kepler mission photometry of
+fast-rotating (rotational periods from 1 to 4 days) stars with spectra of M4V
+to F3V. Applying the originally developed two non-spectral methods, we measured
+the effective period of stellar cycles in 462 objects. The obtained results are
+in accordance with previous measurements by Vida et al. (2014), do not seem to
+result from a beating effect. The performed measurements of Pcyc cluster in a
+specific branch which covers the previously unstudied region in the
+Saar-Brandenburg (1999) diagram, and connects the branch of inactive stars with
+the area populated by super-active objects. It is shown that the formation of
+the discovered branch is due to the alpha-quenching effect, which saturates the
+magnetic dynamo and decreases the cycle periods with the increase of inverted
+Rossby number. This finding is important in the context of the discussion on
+catastrophic quenching and other heuristic approximations of the non-linear
+alpha-effect.",1506.05725v1
+2015-07-16,Radiation Reaction Effect on Laser Driven Auto-Resonant Particle Acceleration,"The effects of radiation reaction force on laser driven auto-resonant
+particle acceleration scheme are studied using Landau-Lifshitz equation of
+motion. These studies are carried out for both linear as well as circularly
+polarized laser fields in the presence of static axial magnetic field. From the
+parametric study, a radiation reaction dominated region has been identified in
+which the particle dynamics is greatly effected by this force. In the radiation
+reaction dominated region the two significant effects on particle dynamics are
+seen viz., (1) saturation in energy gain by the initially resonant particle,
+(2) net energy gain by a initially non-resonant particle which is caused due to
+resonance broadening. It has been further shown that with the optimum choice of
+parameters this scheme can be efficiently used to produce electrons with
+energies in the range of hundreds of TeV. The quantum corrections to the
+Landu-Lifshitz equation of motion have also been taken into account. The
+difference in the energy gain estimates of the particle by the quantum
+corrected and classical Landu-Lifshitz equation are found to be insignificant
+for the present day as well as upcoming laser facilities.",1507.04446v1
+2015-07-16,Linear magnetoresistance in metals: guiding center diffusion in a smooth random potential,"We predict that guiding center (GC) diffusion yields a linear and
+non-saturating (transverse) magnetoresistance in 3D metals. Our theory is
+semi-classical and applies in the regime where the transport time is much
+greater than the cyclotron period, and for weak disorder potentials which are
+slowly varying on a length scale much greater than the cyclotron radius. Under
+these conditions, orbits with small momenta along magnetic field $B$ are
+squeezed and dominate the transverse conductivity. When disorder potentials are
+stronger than the Debye frequency, linear magnetoresistance is predicted to
+survive up to room temperature and beyond. We argue that magnetoresistance from
+GC diffusion explains the recently observed giant linear magnetoresistance in
+3D Dirac materials.",1507.04730v2
+2015-08-08,Effect of electron diamagnetic drifts on cylindrical double-tearing modes,"Double-tearing modes (DTMs) have been proposed as a driver of `off-axis
+sawtooth' crashes in reverse magnetic shear tokamak configurations. Recently
+differential rotation provided by equilibrium sheared flows has been shown
+capable of decoupling the two DTM resonant layers, slowing the growth the
+instability. In this work we instead supply this differential rotation using an
+electron diamagnetic drift, which emerges in the presence of an equilibrium
+pressure gradient and finite Larmor radius physics. Diamagnetic drifts have the
+additional benefit of stabilizing reconnection local to the two tearing layers.
+Conducting linear and nonlinear simulations with the extended MHD code MRC-3d,
+we consider an m=2, n=1 cylindrical double-tearing mode. We show that
+asymmetries between the resonant layers and the emergence of an ideal MHD
+instability cause the DTM evolution to be highly dependent on the location of
+the pressure gradient. By locating a strong drift near the outer, dominant
+resonant surface are we able to saturate the mode and preserve the annular
+current ring, suggesting that the appearance of DTM activity in advanced
+tokamaks depends strongly on the details of the plasma pressure profile.",1508.01959v1
+2015-09-14,Ground-state phases of rung-alternated spin-1/2 Heisenberg ladder,"The ground-state phase diagram of Heisenberg spin-1/2 system on a two-leg
+ladder with rung alternation is studied by combining analytical approaches with
+numerical simulations. For the case of ferromagnetic leg exchanges a unique
+ferrimagnetic ground state emerges, whereas for the case of antiferromagnetic
+leg exchanges several different ground states are stabilized depending on the
+ratio between exchanges along legs and rungs. For the more general case of a
+honeycomb-ladder model for the case of ferromagnetic leg exchanges besides
+usual rung-singlet and saturated ferromagnetic states we obtain a ferrimagnetic
+Luttinger liquid phase with both linear and quadratic low energy dispersions
+and ground state magnetization continuously changing with system parameters.
+For the case of antiferromagnetic exchanges along legs, different dimerized
+states including states with additional topological order are suggested to be
+realized.",1509.04062v1
+2015-09-15,Traveling Wave Parametric Amplifier based on a chain of Coupled Asymmetric SQUIDs,"A traveling wave parametric amplifier (TWPA) composed of a transmission line
+made up of a chain of coupled asymmetric superconducting quantum interference
+devices (SQUIDs) is proposed. The unique nature of this transmission line is
+that its nonlinearity can be tuned with an external magnetic flux and can even
+change sign. This feature of the transmission line can be used to perform phase
+matching in a degenerate four-wave mixing process which can be utilized for
+parametric amplification of a weak signal in the presence of a strong pump.
+Numerical simulations of the TWPA design have shown that with tuning, phase
+matching can be achieved and an exponential gain as a function of the
+transmission line length can be realized. The flexibility of the proposed
+design can realize: compact TWPAs with less than 211 unit cells, signal gains
+greater than 20 dB, 3 dB bandwidth greater than 5.4 GHz, and saturation powers
+up to -98 dBm. This amplifier design is well suited for multiplexed readout of
+quantum circuits or astronomical detectors in a compact configuration which can
+foster on-chip implementations.",1509.04573v1
+2015-09-25,Turbulent Reconnection in Relativistic Plasmas And Effects of Compressibility,"We report turbulence effects on magnetic reconnection in relativistic plasmas
+using 3-dimensional relativistic resistive magnetohydrodynamics simulations. We
+found reconnection rate became independent of the plasma resistivity due to
+turbulence effects similarly to non-relativistic cases. We also found
+compressible turbulence effects modified the turbulent reconnection rate
+predicted in non-relativistic incompressible plasmas; The reconnection rate
+saturates and even decays as the injected velocity approaches to the Alfv\'en
+velocity. Our results indicate the compressibility cannot be neglected when
+compressible component becomes about half of incompressible mode occurring when
+the Alfv\'en Mach number reaches about $0.3$. The obtained maximum reconnection
+rate is around $0.05$ to $0.1$, which will be able to reach around $0.1$ to
+$0.2$ if injection scales are comparable to the sheet length.",1509.07703v2
+2015-11-12,Adiabatic Mach-Zehnder interferometer in dipolar spin-1 condensate,"Mach-Zehnder interferometer, a powerful tool for a wide variety of
+measurements, has been realized with Bose-Einstein condensates in recent
+experiments. In this report, we propose and analyze a realizable scheme for
+performing a Heisenberg-limited Mach-Zehnder interferometry with dipolar spin-1
+condensate. Based upon adiabatic processes of sweeping the transverse magnetic
+field, we demonstrate a perfect phase transition, which accomplishes the beam
+splitter, phase shifter and recombiner as for a Mach-Zehnder interferometer.
+The attractive dipolar interaction ensures the existence of a path-entangled
+state which enhances the phase measurement precision to the Heisenberg limit.
+We also discuss the spin-$1$ squeezing induced in the adiabatic passage and
+show that the squeezing parameter attains its minimal value near the point of
+saturation field.",1511.03893v1
+2015-11-13,Cosmic ray transport and anisotropies to high energies,"A model is introduced, in which the irregularity spectrum of the Galactic
+magnetic field beyond the dissipation length scale is first a Kolmogorov
+spectrum $k^{-5/3}$ at small scales $\lambda \, = \, 2 \pi/k$ with $k$ the
+wave-number, then a saturation spectrum $k^{-1}$, and finally a shock-dominated
+spectrum $k^{-2}$ mostly in the halo/wind outside the Cosmic Ray disk. In an
+isotropic approximation such a model is consistent with the Interstellar Medium
+(ISM) data. With this model we discuss the Galactic Cosmic Ray (GCR) spectrum,
+as well as the extragalactic Ultra High Energy Cosmic Rays (UHECRs), their
+chemical abundances and anisotropies. UHECRs may include a proton component
+from many radio galaxies integrated over vast distances, visible already below
+3 EeV.",1511.04229v1
+2015-11-19,Nonlinear convection stagnation point heat transfer and MHD fluid flow in porous medium towards a permeable shrinking sheet,"This investigation deals with the analysis of stagnation point heat transfer
+and corresponding flow features of hydromagnetic viscous incompressible fluid
+over a vertical shrinking sheet. The considered sheet is assumed to be
+permeable and subject to addition of stagnation point to control the generated
+vorticity in the boundary layer. The sheet is placed on the right side of the
+fluid saturated porous medium which is having permeability of specified form.
+Nonlinear convection waves in the flow field are realized due to the envisaged
+nonlinear relation between density and temperature. The equations governing the
+nonlinear convection boundary layer flow are modeled and simplified using
+similarity transformations. The economized equations are solved for numerical
+solutions by employing the implicit finite difference scheme also known as
+Keller-box method. The influence of the associated parameters of the problem on
+velocity and temperature distributions, skin friction and rate of heat transfer
+are presented through graphs and tables, and qualitatively discussed. The study
+reveals that interaction among magnetic field, porous medium permeability and
+nonlinear convection parameters substantially enhance the solution range and
+thus endorse their control to sustain the boundary layer flow.",1511.06109v1
+2015-12-14,Influence of dephasing on many-body localization,"We study the effects of dephasing noise on a prototypical many-body localized
+system -- the XXZ spin 1/2 chain with a disordered magnetic field. At times
+longer than the inverse dephasing strength the dynamics of the system is
+described by a probabilistic Markov process on the space of diagonal density
+matrices, while all off-diagonal elements of the density matrix decay to zero.
+The generator of the Markovian process is a bond-disordered spin chain. The
+scaling variable is identified, and independence of relaxation on the
+interaction strength is demonstrated. We show that purity and von Neumann
+entropy are extensive, showing no signatures of localization, while the
+operator space entanglement entropy exhibits a logarithmic growth with time
+until the final saturation corresponding to localization breakdown, suggesting
+a many-body localized dynamics of the effective Markov process.",1512.04408v2
+2015-12-16,Observationally constraining gravitational wave emission from short gamma-ray burst remnants,"Observations of short gamma-ray bursts indicate ongoing energy injection
+following the prompt emission, with the most likely candidate being the birth
+of a rapidly rotating, highly magnetised neutron star. We utilise X-ray
+observations of the burst remnant to constrain properties of the nascent
+neutron star, including its magnetic field-induced ellipticity and the
+saturation amplitude of various oscillation modes. Moreover, we derive strict
+upper limits on the gravitational wave emission from these objects by looking
+only at the X-ray light curve, showing the burst remnants are unlikely to be
+detected in the near future using ground-based gravitational wave
+interferometers such as Advanced LIGO.",1512.05368v2
+2015-12-22,Spin torque study of the spin Hall conductivity and spin diffusion length in platinum thin films with varying resistivity,"We report measurements of the spin torque efficiencies in
+perpendicularly-magnetized Pt/Co bilayers where the Pt resistivity $\rho_{Pt}$
+is strongly dependent on thickness $t_{Pt}$ . The damping-like spin Hall torque
+efficiency per unit current density, $\xi^j_{DL}$ , varies significantly with
+$t_{Pt}$, exhibiting a peak value $\xi^j_{DL}=0.12$ at $t_{Pt} = 2.8 - 3.9$ nm.
+In contrast, $\xi^j_{DL}/\rho_{Pt}$ increases monotonically with $t_{Pt}$ and
+saturates for $t_{Pt} > 5$ nm, consistent with an intrinsic spin Hall effect
+mechanism, in which $\xi^j_{DL}$ is enhanced by an increase in $\rho_{Pt}$ .
+Assuming the Elliott-Yafet spin scattering mechanism dominates we estimate that
+the spin diffusion length $\lambda_s = (0.77 \pm 0.08) \times 10^{-15} \Omega
+m^2 /\rho_{Pt}$.",1512.06931v1
+2016-01-24,Inelastic electron scattering off a quantum dot in the cotunneling regime: the signature of mesoscopic Stoner instability,"We explore the inelastic electron scattering cross section off a quantum dot
+close to the Stoner instability. We focus on the regime of strong Coulomb
+blockade in which the scattering cross section is dominated by the cotunneling
+processes. For large enough exchange interaction the quantum dot acquires a
+finite total spin in the ground state. In this, so-called mesoscopic Stoner
+instability, regime we find that at low enough temperatures the inelastic
+scattering cross section (including the contribution due to an elastic electron
+spin-flip) for an electron with a low energy with respect to the chemical
+potential is different from the case of a magnetic impurity with the same spin.
+This difference stems from (i) presence of a low-lying many-body states of a
+quantum dot and (ii) the correlations of the tunneling amplitudes. Our results
+provide a possible explanation for absence of the dephasing rate saturation at
+low temperatures in recent experiment [N. Teneh, A. Yu. Kuntsevich, V. M.
+Pudalov, and M. Reznikov, Phys. Rev. Lett. 109, 226403 (2012)] in which
+existence of local spin droplets in disordered electron liquid has been
+unraveled.",1601.06381v1
+2016-01-25,Large Magnetoresistance in Compensated Semimetals TaAs$_2$ and NbAs$_2$,"We report large magnetoresistance (MR) at low temperatures in
+single-crystalline nonmagnetic compounds TaAs$_2$ and NbAs$_2$. Both compounds
+exhibit parabolic-field-dependent MR larger than $5\times10^3$ in a magnetic
+field of 9 Tesla at 2 K. The MR starts to deviate from parabolic dependence
+above 10 T and intends to be saturated in 45 T for TaAs$_2$ at 4.2 K. The Hall
+resistance measurements and band structural calculations reveal their
+compensated semimetal characteristics. The large MR at low temperatures is
+ascribed to a resonance effect of the balanced electrons and holes with large
+mobilities. We also discuss the relation of the MR and samples' quality for
+TaAs$_2$ and other semimetals. We found that the magnitudes of MR are strongly
+dependent on the samples' quality for different compounds.",1601.06482v1
+2016-02-16,Perfect charge compensation in extremely large magnetoresistance materials LaSb and LaBi revealed by the first-principles calculations,"By the first-principles electronic structure calculations, we have
+systematically studied the electronic structures of recently discovered
+extremely large magnetoresistance (XMR) materials LaSb and LaBi. We find that
+both LaSb and LaBi are semimetals with the electron and hole carriers in
+perfect balance. The calculated carrier densities in the order of $10^{20}$
+cm$^{-3}$ are in good agreement with the experimental values, implying long
+mean free time of carriers and thus high carrier mobilities. With a
+semiclassical two-band model, the perfect charge compensation and high carrier
+mobilities naturally explain (i) the XMR observed in LaSb and LaBi; (ii) the
+non-saturating quadratic dependence of XMR on external magnetic field; and
+(iii) the resistivity plateau in the turn-on temperature behavior at very low
+temperatures. The explanation of these features without resorting to the
+topological effect indicates that they should be the common characteristics of
+all perfectly electron-hole compensated semimetals.",1602.05061v1
+2016-02-28,Goldilocks Probes for Noisy Interferometry via Quantum Annealing to Criticality,"Quantum annealing is explored as a resource for quantum information beyond
+solution of classical combinatorial problems. Envisaged as a generator of
+robust interferometric probes, we examine a Hamiltonian of $N>> 1$
+uniformly-coupled spins subject to a transverse magnetic field. The discrete
+many-body problem is mapped onto dynamics of a single one-dimensional particle
+in a continuous potential. This reveals all the qualitative features of the
+ground state beyond typical mean-field or large classical spin models. It
+illustrates explicitly a graceful warping from an entangled unimodal to
+bi-modal ground state in the phase transition region. The transitional
+`Goldilocks' probe has a component distribution of width $N^{2/3}$ and exhibits
+characteristics for enhanced phase estimation in a decoherent environment. In
+the presence of realistic local noise and collective dephasing, we find this
+probe state asymptotically saturates ultimate precision bounds calculated
+previously. By reducing the transverse field adiabatically, the Goldilocks
+probe is prepared in advance of the minimum gap bottleneck, allowing the
+annealing schedule to be terminated `early'. Adiabatic time complexity of probe
+preparation is shown to be linear in $N$",1602.08752v1
+2016-05-11,Magnetotransport and de Haas-van Alphen measurements in the type-II Weyl semimetal TaIrTe$_4$,"The layered ternary compound TaIrTe$_4$ has been predicted to be a type-II
+Weyl semimetal with only four Weyl points just above the Fermi energy.
+Performing magnetotransport measurements on this material we find that the
+resistivity does not saturate for fields up to 70 T and follows a $ \rho \sim
+B^{1.5}$ dependence. Angular-dependent de Haas-van Alphen (dHvA) measurements
+reveal four distinct frequencies. Analyzing these magnetic quantum oscillations
+by use of density functional theory (DFT) calculations we establish that in
+TaIrTe$_4$ the Weyl points are located merely $\sim$ 40-50 meV above the
+chemical potential, suggesting that the chemical potential can be tuned into
+the four Weyl nodes by moderate chemistry or external pressure, maximizing
+their chiral effects on electronic and magnetotransport properties.",1605.03380v1
+2016-07-05,Inverse participation ratios in the XXZ spin chain,"We investigate numerically the inverse participation ratios in a spin-1/2 XXZ
+chain, computed in the ""Ising"" basis (i.e., eigenstates of $\sigma^z_i$). We
+consider in particular a quantity $T$, defined by summing the inverse
+participation ratios of all the eigenstates in the zero magnetization sector of
+a finite chain of length $N$, with open boundary conditions. From a dynamical
+point of view, $T$ is proportional to the stationary return probability to an
+initial basis state, averaged over all the basis states (initial conditions).
+We find that $T$ exhibits an exponential growth, $T\sim\exp(aN)$, in the gapped
+phase of the model and a linear scaling, $T\sim N$, in the gapless phase. These
+two different behaviors are analyzed in terms of the distribution of the
+participation ratios of individual eigenstates. We also investigate the effect
+of next-nearest-neighbor interactions, which break the integrability of the
+model. Although the massive phase of the non-integrable model also has
+$T\sim\exp(aN)$, in the gapless phase $T$ appears to saturate to a constant
+value.",1607.01300v2
+2016-07-10,Robust Topological Terahertz Circuits using Semiconductors,"Topological Insulator-based devices can transport electrons/photons at the
+surfaces of materials without any back reflections, even in the presence of
+obstacles. Topological properties have recently been studied using
+non-reciprocal materials such as gyromagnetics or using bianisotropy. However,
+these effects usually saturate at optical frequencies and limit our ability to
+scale down devices. In order to implement topological devices that we introduce
+in this paper for the terahertz range, we show that semiconductors can be
+utilized via their cyclotron resonance in combination with small magnetic
+fields. We propose novel terahertz operating devices such as the topological
+tunable power splitter and the topological circulator. This work opens new
+perspectives in the design of terahertz integrated devices and circuits with
+high functionality.",1607.02697v2
+2016-07-19,Interaction-Induced Weakening of Localization in Few-Particle Disordered Heisenberg Chains,"We investigate real-space localization in the few-particle regime of the XXZ
+spin-$1/2$ chain with a random magnetic field. Our investigation focuses on the
+time evolution of the spatial variance of non-equilibrium densities, as
+resulting for a specific class of initial states, namely, pure product states
+of densely packed particles. Varying the strength of both particle-particle
+interactions and disorder, we numerically calculate the long-time evolution of
+the spatial variance $\sigma(t)$. For the two-particle case, the saturation of
+this variance yields an increased but finite localization length, with a
+parameter scaling different to known results for bosons. We find that this
+interaction-induced increase is the stronger the more particles are taken into
+account in the initial condition. We further find that our non-equilibrium
+dynamics are clearly inconsistent with normal diffusion and instead point to
+subdiffusive dynamics with $\sigma(t) \propto t^{1/4}$.",1607.05664v3
+2016-08-26,Mass enhancement in multiple bands approaching optimal doping in a high-temperature superconductor,"Pnictides provide an opportunity to study the effects of quantum criticality
+in a multi-band high temperature superconductor. Quasiparticle mass divergence
+near optimal doping, observed in two major classes of high-temperature
+superconductors, pnictides and cuprates, is a direct experimental indicator of
+enhanced electronic interactions that accompany quantum criticality. Whether
+quasiparticles on all Fermi surface pockets in BaFe2(As1-xPx)2 are affected by
+quantum criticality is an open question, which specific heat measurements at
+high magnetic fields can directly address. Here we report specific heat
+measurements up to 35T in BaFe2(As1-xPx)2 over a broad doping range, 0.44 <= x
+<= 0.6. We observe saturation of C/T in the normal state at all dopings where
+superconductivity is fully suppressed. Our measurements demonstrate that
+quasiparticle mass increases towards optimal doping in multiple pockets, some
+of which exhibit even stronger mass enhancement than previously reported from
+quantum oscillations of a single pocket.",1608.07510v2
+2016-10-05,"The weakly nonlinear magnetorotational instability in a global, cylindrical Taylor-Couette flow","We conduct a global, weakly nonlinear analysis of the magnetorotational
+instability (MRI) in a Taylor-Couette flow. This is a multiscale perturbative
+treatment of the nonideal, axisymmetric MRI near threshold, subject to
+realistic radial boundary conditions and cylindrical geometry. We analyze both
+the standard MRI, initialized by a constant vertical background magnetic field,
+and the helical MRI, with an azimuthal background field component. This is the
+first weakly nonlinear analysis of the MRI in a global Taylor-Couette geometry,
+as well as the first weakly nonlinear analysis of the helical MRI. We find that
+the evolution of the amplitude of the standard MRI is described by a real
+Ginzburg-Landau equation (GLE), while the amplitude of the helical MRI takes
+the form of a complex GLE. This suggests that the saturated state of the
+helical MRI may itself be unstable on long spatial and temporal scales.",1610.01603v2
+2016-10-28,Dynamo-driven plasmoid formation from a current-sheet instability,"Axisymmetric current-carrying plasmoids are formed in the presence of
+nonaxisymmetric fluctuations during nonlinear three-dimensional resistive MHD
+simulations in a global toroidal geometry. We utilize the helicity injection
+technique to form an initial poloidal flux in the presence of a toroidal guide
+field. As helicity is injected, two types of current sheets are formed from 1)
+the oppositely directed field lines in the injector region (primary
+reconnecting current sheet), and 2) the poloidal flux compression near the
+plasma edge (edge current sheet). We first find that nonaxisymmetic
+fluctuations arising from the current-sheet instability isolated near the
+plasma edge have tearing parity but can nevertheless grow fast (on the poloidal
+Alfven time scale). These modes saturate by breaking up the current sheet.
+Second, for the first time a dynamo poloidal flux amplification is observed at
+the reconnetion site (in the region of the oppositely directed magnetic field).
+This fluctuation-induced flux amplification increases the local Lundquist
+number, which then triggers a plasmoid instability and breaks the primary
+current sheet at the reconnection site. The plasmoids formation driven by
+large-scale flux amplification, i.e. a large-scale dynamo, observed here has
+strong implications for astrophysical reconnection as well as fast reconnection
+events in laboratory plasmas.",1610.09050v1
+2016-10-28,FORC+: A method for separating reversible from irreversible behavior using first order reversal curves,"First Order Reversal Curves (FORCs) have been used for a number of years for
+the extraction of information from magnetization measurements. The results are
+most unambiguous for irreversible processes -- for a collection of Preisach
+hysterons, one gets a ""FORC distribution"" $\rho(H_{down},H_{up})$, the number
+of hysterons with given downward \& upward reversal fields. There have been
+many proposals for dealing with reversible behavior, usually involving
+inserting it somehow into the irreversible FORC distribution. Here we will try
+to do the opposite, to separate them into another function which we will call
+the (reversible) ""saturation field distribution"", which is identically zero for
+a completely irreversible system of hysterons, while the irreversible FORC
+distribution is identically zero for a reversible system. Thus in a system with
+both purely reversible and purely irreversible components, such as
+single-domain Stoner-Wohlfarth particles with hard or easy axis along the
+field, this approach cleanly separates them. For more complicated systems, as
+with conventional FORC distributions, it at least provides a ""signature"" making
+it possible to identify microscopic models that might give a particular pair of
+irreversible and reversible distributions.",1610.09199v1
+2016-11-14,Light-by-light scattering sum rules in light of new data,"We evaluate the light-quark meson contributions to three exact light-by-light
+scattering sum rules in light of new data by the Belle Collaboration, which
+recently has extracted the transition form factors of the tensor meson
+$f_2(1270)$ as well as of the scalar meson $f_0(980)$. We confirm a previous
+finding that the $\eta, \eta^\prime$ and helicity-2 $f_2(1270)$ contributions
+saturate one of these sum rules up to photon virtualities around 1 GeV$^2$. At
+larger virtualities, our sum rule analysis shows an important contribution of
+the $f_2(1565)$ meson and provides a first empirical extraction of its
+helicity-2 transition form factor. Two further sum rules allow us to predict
+the helicity-0 and helicity-1 transition form factors of the $f_2(1270)$ meson.
+Furthermore, our analysis also provides an update for the scalar and tensor
+meson hadronic light-by-light contributions to the muon's anomalous magnetic
+moment.",1611.04646v2
+2016-11-18,Temporal evolution of auto-oscillations in a YIG/Pt microdisc driven by pulsed spin Hall effect-induced spin-transfer torque,"The temporal evolution of pulsed Spin Hall Effect - Spin Transfer Torque
+(SHE-STT) driven auto-oscillations in a Yttrium Iron Garnet (YIG) / platinum
+(Pt) microdisc is studied experimentally using time-resolved Brillouin Light
+Scattering (BLS) spectroscopy. It is demonstrated that the frequency of the
+auto-oscillations is different in the center and at the edge of the
+investigated disc that is related to the simultaneous STT excitation of a
+bullet and a non-localized spin-wave mode. Furthermore, the magnetization
+precession intensity is found to saturate on a time scale of 20 ns or longer,
+depending on the current density. For this reason, our findings suggest that a
+proper ratio between the current and the pulse duration is of crucial
+importance for future STT-based devices.",1611.06054v1
+2016-11-26,Specific Heat of Spin Excitations Measured by FerromagneticResonance,"Using ferromagnetic-resonance spectroscopy (FMR), we investigate the
+anisotropic properties of epitaxial 3 nmPt/2 nmAg/10 nmFe/10 nmAg/GaAs(001)
+films in fully saturated meta-stable states at temperatures ranging from 70 K
+to 280 K. By comparison to spin-wave theory calculations, we identify the role
+of thermal fluctuation of magnons in overcoming the energy barrier associated
+with these meta-stable states. We show that the energy associated with the size
+of the barrier that bounds the meta-stable regime is proportional to the heat
+stored in the magnonic bath. Our findings offer the possibility to measure the
+magnonic contribution to the heat capacity by FMR, independent of other
+contributions at temperatures ranging from 0 K to ambient temperature and
+above. The only requirement being that the selected sample exhibits magnetic
+anisotropy, here, magnetocrystalline anisotropy.",1611.08713v2
+2016-12-15,Exploring Localization in Nuclear Spin Chains,"Characterizing out-of-equilibrium many-body dynamics is a complex but crucial
+task for quantum applications and the understanding of fundamental phenomena. A
+central question is the role of localization in quenching quantum
+thermalization, and whether localization survives in the presence of
+interactions. The localized phase of interacting systems (many-body
+localization, MBL) exhibits a long-time logarithmic growth in entanglement
+entropy that distinguishes it from the noninteracting Anderson localization
+(AL), but entanglement is difficult to measure experimentally. Here, we present
+a novel correlation metric, capable of distinguishing MBL from AL in
+high-temperature spin systems. We demonstrate the use of this metric to detect
+localization in a natural solidstate spin system using nuclear magnetic
+resonance (NMR). We engineer the natural Hamiltonian to controllably introduce
+disorder and interactions and observe the emergence of localization. In
+particular, while our correlation metric saturates for AL, it keeps increasing
+logarithmically for MBL, a behavior reminiscent of entanglement entropy, as we
+confirm by simulations. Our results show that our NMR techniques, akin to
+measuring out-of-time correlations, are well suited for studying localization
+in spin systems.",1612.05249v1
+2016-12-15,Giant Hall photoconductivity in narrow-gapped Dirac materials,"Carrier dynamics acquire a new character in the presence of Bloch-band Berry
+curvature, which naturally arises in gapped Dirac materials (GDMs). Here we
+argue that photoresponse in GDMs with small band gaps is dramatically enhanced
+by Berry curvature. This manifests in a giant and saturable Hall
+photoconductivity when illuminated by circularly polarized light. Unlike Hall
+motion arising from a Lorentz force in a magnetic field, which impedes
+longitudinal carrier motion, Hall photoconductivity arising from Berry
+curvature can boost longitudinal carrier transport. In GDMs, this results in a
+helicity-dependent photoresponse in the Hall regime, where photoconductivity is
+dominated by its Hall component. We find that the induced Hall conductivity per
+incident irradiance is enhanced by up to six orders of magnitude when moving
+from the visible regime (with corresponding band gaps) to the far infrared.
+These results suggest that narrow-gap GDMs are an ideal test-bed for the unique
+physics that arise in the presence of Berry curvature, and open a new avenue
+for infrared and terahertz optoelectronics.",1612.05269v1
+2017-02-03,Linear magnetoresistance and surface to bulk coupling in topological insulator thin films,"We explore the temperature dependent magnetoresistance of bulk insulating
+topological insulator thin films. Thin films of Bi2Se2Te and BiSbTeSe1.6 were
+grown using Pulsed Laser Deposition technique and subjected to transport
+measurements. Magnetotransport measurements indicate a non-saturating linear
+magnetoresistance (LMR) behavior at high magnetic field values. We present a
+careful analysis to explain the origin of LMR taking into consideration all the
+existing models of LMR. Here we consider that the bulk insulating states and
+the metallic surface states constitute two parallel conduction channels.
+Invoking this, we were able to explain linear magnetoresistance behavior as a
+competition between these parallel channels. We observe that the crossover
+field, where LMR sets in, decreases with increasing temperature. We propose
+that this cross over field can be used phenomenologically to estimate the
+strength of surface to bulk coupling.",1702.00950v1
+2017-02-26,Enhanced spin-orbit torques in MnAl/Ta films with improving chemical ordering,"We report the enhancement of spin-orbit torques in MnAl/Ta films with
+improving chemical ordering through annealing. The switching current density is
+increased due to enhanced saturation magnetization MS and effective anisotropy
+field HK after annealing. Both damplinglike effective field HD and fieldlike
+effective field HF have been increased in the temperature range of 50 to 300 K.
+HD varies inversely with MS in both of the films, while the HF becomes liner
+dependent on 1/MS in the annealed film. We infer that the improved chemical
+ordering has enhanced the interfacial spin transparency and the transmitting of
+the spin current in MnAl layer.",1702.07990v1
+2017-04-05,Robust odd-parity superconductivity in the doped topological insulator Nb$_x$Bi$_2$Se$_3$,"We present resistivity and magnetization measurements on proton-irradiated
+crystals demonstrating that the superconducting state in the doped topological
+superconductor Nb$_x$Bi$_2$Se$_3$ (x = 0.25) is surprisingly robust against
+disorder-induced electron scattering. The superconducting transition
+temperature $T_c$ decreases without indication of saturation with increasing
+defect concentration, and the corresponding scattering rates far surpass
+expectations based on conventional theory. The low-temperature variation of the
+London penetration depth $\Delta\lambda(T)$ follows a power law
+($\Delta\lambda(T)\sim T^2$) indicating the presence of symmetry-protected
+point nodes. Our results are consistent with the proposed robust nematic $E_u$
+pairing state in this material.",1704.01225v1
+2017-04-20,Ferrimagnetism in the Spin-1/2 Heisenberg Antiferromagnet on a Distorted Triangular Lattice,"The ground state of the spin-$1/2$ Heisenberg antiferromagnet on a distorted
+triangular lattice is studied using a numerical-diagonalization method. The
+network of interactions is the $\sqrt{3}\times\sqrt{3}$ type; the interactions
+are continuously controlled between the undistorted triangular lattice and the
+dice lattice. We find new states between the nonmagnetic 120-degree-structured
+state of the undistorted triangular case and the up-up-down state of the dice
+case. The intermediate states show spontaneous magnetizations that are smaller
+than one third of the saturated magntization corresponding to the up-up-down
+state.",1704.06013v2
+2017-04-28,The design and the performance of stratospheric mission in the search for the Schumann resonances,"The technical details of a balloon stratospheric mission that is aimed at
+measuring the Schumann resonances are described. The gondola is designed
+specifically for the measuring of faint effects of ELF (Extremely Low Frequency
+electromagnetic waves) phenomena. The prototype met the design requirements.
+The ELF measuring system worked properly for entire mission; however, the level
+of signal amplification that was chosen taking into account ground-level
+measurements was too high. Movement of the gondola in the Earth magnetic field
+induced the signal in the antenna that saturated the measuring system. This
+effect will be taken into account in the planning of future missions. A large
+telemetry dataset was gathered during the experiment and is currently under
+processing. The payload consists also of biological material as well as
+electronic equipment that was tested under extreme conditions.",1704.08930v2
+2017-06-21,Scaling of Majorana Zero-Bias Conductance Peaks,"We report an experimental study of the scaling of zero-bias conductance peaks
+compatible with Majorana zero modes as a function of magnetic field, tunnel
+coupling, and temperature in one-dimensional structures fabricated from an
+epitaxial semiconductor-superconductor heterostructure. Results are consistent
+with theory, including a peak conductance that is proportional to tunnel
+coupling, saturates at $2e^2/h$, decreases as expected with field-dependent
+gap, and collapses onto a simple scaling function in the dimensionless ratio of
+temperature and tunnel coupling.",1706.07033v2
+2017-06-29,Magnetotransport properties of MoP$_2$,"We report magnetotransport and de Haas-van Alphen (dHvA) effect studies on
+MoP$_2$ single crystals, predicted to be type-2 Weyl semimetal with four pairs
+of robust Weyl points located below the Fermi level and long Fermi arcs. The
+temperature dependence of resistivity shows a peak before saturation, which
+does not move with magnetic field. Large nonsaturating magnetoresistance (MR)
+was observed, and the field dependence of MR exhibits a crossover from
+semicalssical weak-field $B^2$ dependence to the high-field linear-field
+dependence, indicating the presence of Dirac linear energy dispersion. In
+addition, systematic violation of Kohler's rule was observed, consistent with
+multiband electronic transport. Strong spin-orbit coupling (SOC) splitting has
+an effect on dHvA measurements whereas the angular-dependent dHvA orbit
+frequencies agree well with the calculated Fermi surface. The cyclotron
+effective mass $\sim$ 1.6$m_e$ indicates the bands might be trivial, possibly
+since the Weyl points are located below the Fermi level. Interestingly,
+quasi-two dimensional(2D) band structure is observed even though the crystal
+structure of MoP$_2$ is not layered.",1706.09830v1
+2017-07-21,Modeling alignment enhancement for solid polarized targets,"A model of dynamic orientation using optimized radiofrequency (RF)
+irradiation produced perpendicular to the holding field is developed for the
+spin-1 system required for tensor-polarized fixed-target experiments. The
+derivation applies to RF produced close to the Larmor frequency of the nucleus
+and requires the electron spin-resonance linewidth to be much smaller than the
+nuclear magnetic resonance frequency. The rate equations are solved numerically
+to study a semi-saturated steady-state resulting from the two sources of
+irradiation: microwave from the DNP process and the additional RF used to
+manipulate the tensor polarization. The steady-state condition and
+continuous-wave NMR lineshape are found that optimize the spin-1 alignment in
+the polycrystalline materials used as solid polarized targets in charged-beam
+nuclear and particle physics experiments.",1707.07065v1
+2017-07-30,Incommensurate magnetism near quantum criticality in CeNiAsO,"Two phase transitions in the tetragonal strongly correlated electron system
+CeNiAsO were probed by neutron scattering and zero field muon spin rotation.
+For $T <T_{N1}$ = 8.7(3) K, a second order phase transition yields an
+incommensurate spin density wave with wave vector $\textbf{k} = (0.44(4), 0,
+0)$. For $T < T_{N2}$ = 7.6(3) K, we find co-planar commensurate order with a
+moment of $0.37(5)~\mu_B$, reduced to $30 \%$ of the saturation moment of the
+$|\pm\frac{1}{2}\rangle$ Kramers doublet ground state, which we establish by
+inelastic neutron scattering. Muon spin rotation in $\rm CeNiAs_{1-x}P_xO$
+shows the commensurate order only exists for x $\le$ 0.1 so the transition at
+$x_c$ = 0.4(1) is from an incommensurate longitudinal spin density wave to a
+paramagnetic Fermi liquid.",1707.09645v2
+2017-08-18,Strongly-coupled anisotropic gauge theories and holography,"We initiate a non-perturbative study of anisotropic, non-conformal and
+confining gauge theories that are holographically realized in gravity by
+generic Einstein-Axion-Dilaton systems. In the vacuum our solutions describe RG
+flows from a conformal field theory in the UV to generic scaling solutions in
+the IR with generic hyperscaling violation and dynamical exponents $\theta$ and
+$z$. We formulate a generalization of the holographic c-theorem to the
+anisotropic case. At finite temperature, we discover that the anisotropic
+deformation reduces the confinement-deconfinement phase transition temperature
+suggesting a possible alternative explanation of inverse magnetic catalysis
+solely based on anisotropy. We also study transport and diffusion properties in
+anisotropic theories and observe in particular that the butterfly velocity that
+characterizes both diffusion and growth of chaos transverse to the anisotropic
+direction, saturates a constant value in the IR which can exceed the bound
+given by the conformal value.",1708.05691v2
+2017-08-28,Dependence of Dzyaloshinskii-Moriya interaction on the oxygen coverage in Pt/Co/MOx trilayers,"We have studied the interfacial Dzyaloshinskii-Moriya interaction (DMI) in a
+series of Pt/Co/MOx (M=Al, Gd) trilayers in which the degree of oxidation of
+the top Co interface is varied. To access to reliable values of the DMI
+strength, we have used a method based on the measurement of the saturation
+velocity of field driven chiral N\'eel domain walls. We show that the effective
+DMI strength in the Pt/Co/MOx trilayers varies with the oxidation degree of the
+Co/MOx interface. This strongly suggests that the Co/MOx interface gives a
+distinct contribution to the total DMI, adding to that of the Pt/Co interface.
+The DMI presents a maximum for the oxygen coverage maximizing also the
+interface magnetic anisotropy energy Ks. This calls for common microscopic
+origins for the contributions of the Co/MOx interface to DMI and Ks.",1708.08516v1
+2017-09-14,Proximity Effect in Superconducting-Ferromagnetic Granular Structures,"We examined the proximity effect in granular films made of Pb, a
+superconductor, and Ni, a ferromagnet, with various compositions. Slow decay of
+the critical temperature as a function of the relative volume concentration of
+Ni per sample was demonstrated by our measurements, followed by a saturation of
+T$_c$. Using an approximate theoretical description of our granular system in
+terms of a layered one, we show that our data can only be reasonably fitted by
+a multilayer model. This indicates the importance of the interplay between
+different ferromagnetic grains; when non-collinearly magnetized they should
+lead to triplet Cooper pairing.",1709.04760v2
+2017-09-15,Impact and mitigation strategy for future solar flares,"It is widely established that extreme space weather events associated with
+solar flares are capable of causing widespread technological damage. We develop
+a simple mathematical model to assess the economic losses arising from these
+phenomena over time. We demonstrate that the economic damage is characterized
+by an initial period of power-law growth, followed by exponential amplification
+and eventual saturation. We outline a mitigation strategy to protect our planet
+by setting up a magnetic shield to deflect charged particles at the Lagrange
+point L$_1$, and demonstrate that this approach appears to be realizable in
+terms of its basic physical parameters. We conclude our analysis by arguing
+that shielding strategies adopted by advanced civilizations will lead to
+technosignatures that are detectable by upcoming missions.",1709.05348v2
+2017-10-30,Nontopological first-order vortices in a gauged $CP(2)$ model with a dielectric function,"We consider nontopological first-order solitons arising from a gauged $CP(2)$
+model in the presence of the Maxwell term multiplied by a nontrivial dielectric
+function. We implement the corresponding first-order scenario by proceeding the
+minimization of the total energy, this way introducing the corresponding energy
+lower-bound, such a construction being only possible due to a differential
+constraint including the dielectric function itself and the self-interacting
+potential defining the model. We saturate the aforementioned bound by focusing
+our attention on those solutions fulfilling a particular set of two coupled
+first-order differential equations. In the sequel, in order to solve these
+equations, we choose the dielectric function explicitly, also calculating the
+corresponding self-interacting potential. We impose appropriate boundary
+conditions supporting nontopological solitons, from which we verify that the
+energy of final structures is proportional to the magnetic flux they engender,
+both quantities being not quantized, as expected. We depict the new numerical
+solutions, whilst commenting on the main properties they present.",1710.11215v1
+2017-11-04,"Superconducting, Insulating, and Anomalous Metallic Regimes in a Gated Two-Dimensional Semiconductor-Superconductor Array","The superconductor-insulator transition in two dimensions has been widely
+investigated as a paradigmatic quantum phase transition. The topic remains
+controversial, however, because many experiments exhibit a metallic regime with
+saturating low-temperature resistance, at odds with conventional theory. Here,
+we explore this transition in a novel, highly controllable system, a
+semiconductor heterostructure with epitaxial Al, patterned to form a regular
+array of superconducting islands connected by a gateable quantum well. Spanning
+nine orders of magnitude in resistance, the system exhibits regimes of
+superconducting, metallic, and insulating behavior, along with signatures of
+flux commensurability and vortex penetration. An in-plane magnetic field
+eliminates the metallic regime, restoring the direct superconductor-insulator
+transition, and improves scaling, while strongly altering the scaling exponent.",1711.01451v2
+2017-12-05,The Weak Gravity Conjecture and Emergence from an Ultraviolet Cutoff,"We study ultraviolet cutoffs associated with the Weak Gravity Conjecture
+(WGC) and Sublattice Weak Gravity Conjecture (sLWGC). There is a magnetic WGC
+cutoff at the energy scale $e G_N^{-1/2}$ with an associated sLWGC tower of
+charged particles. A more fundamental cutoff is the scale at which gravity
+becomes strong and field theory breaks down entirely. By clarifying the nature
+of the sLWGC for nonabelian gauge groups we derive a parametric upper bound on
+this strong gravity scale for arbitrary gauge theories. Intriguingly, we show
+that in theories approximately saturating the sLWGC, the scales at which loop
+corrections from the tower of charged particles to the gauge boson and graviton
+propagators become important are parametrically identical. This suggests a
+picture in which gauge fields emerge from the quantum gravity scale by
+integrating out a tower of charged matter fields. We derive a converse
+statement: if a gauge theory becomes strongly coupled at or below the quantum
+gravity scale, the WGC follows. We sketch some phenomenological consequences of
+the UV cutoffs we derive.",1712.01868v2
+2017-12-05,Two-dimensional semimetal in HgTe quantum well under hydrostatic pressure,"We report results of systematic measurements of charge transport properties
+of the 20.5nm wide HgTe-based quantum well in perpendicular magnetic field,
+performed under hydrostatic pressures up to 15.1 kbar. At ambient pressure
+transport is well described by the two-band semiclassical model.In contrast, at
+elevated pressure, we observed non-monotonic pressure dependence of resistivity
+at CNP. For pressures lower than $\approx9$ kbar, resistivity grows with
+pressure, in accord with expectations from the band structure calculations and
+the model incorporating effects of disorder on transport in 2D semimetals with
+indirect band overlap. For higher pressures, the resistivity saturates and
+starts decreasing upon further increase of pressure. Above $\approx14$ kbar the
+resistance and hopping transport character sharply change, which may indicate
+formation of the excitonic insulator state. The data also reveals strong
+influence of disorder on transport in 2D electron-hole system with a small band
+overlap.",1712.01879v2
+2018-01-05,Self-excitation in a helical liquid metal flow: The Riga dynamo experiments,"The homogeneous dynamo effect is at the root of magnetic field generation in
+cosmic bodies, including planets, stars and galaxies. While the underlying
+theory had increasingly flourished since the middle of the 20th century,
+hydromagnetic dynamos were not realized in laboratory until 1999. On 11
+November 1999, this situation changed with the first observation of a kinematic
+dynamo in the Riga experiment. Since that time, a series of experimental
+campaigns has provided a wealth of data on the kinematic and the saturated
+regime. This paper is intended to give a comprehensive survey about these
+experiments, to summarize their main results and to compare them with numerical
+simulations.",1801.01749v1
+2018-01-22,Bootstrapping hypercubic and hypertetrahedral theories in three dimensions,"There are three generalizations of the Platonic solids that exist in all
+dimensions, namely the hypertetrahedron, the hypercube, and the
+hyperoctahedron, with the latter two being dual. Conformal field theories with
+the associated symmetry groups as global symmetries can be argued to exist in
+$d=3$ spacetime dimensions if the $\varepsilon=4-d$ expansion is valid when
+$\varepsilon\to1$. In this paper hypercubic and hypertetrahedral theories are
+studied with the non-perturbative numerical conformal bootstrap. In the $N=3$
+cubic case it is found that a bound with a kink is saturated by a solution with
+properties that cannot be reconciled with the $\varepsilon$ expansion of the
+cubic theory. Possible implications for cubic magnets and structural phase
+transitions are discussed. For the hypertetrahedral theory evidence is found
+that the non-conformal window that is seen with the $\varepsilon$ expansion
+exists in $d=3$ as well, and a rough estimate of its extent is given.",1801.07127v4
+2018-02-08,Ultraviolet laser spectroscopy of aluminum atoms in hollow-cathode lamp,"We report precision measurement of aluminum atoms
+${^{2}P_{1/2}}-{^{2}S_{1/2}}$ transition at 394 nm and
+${^{2}P_{3/2}}-{^{2}S_{1/2}}$ transition at 396 nm in a hollow-cathode lamp
+(HCL). Both absorption spectroscopy and saturated absorption spectroscopy (SAS)
+are performed. From the absorption spectroscopy the Doppler linewidth is
+estimated to be 2.6 GHz. The SAS spectroscopy is analyzed based on the
+velocity-changing-effect model. With a frequency comb calibrated wavemeter, the
+frequencies of ${^{2}P_{1/2}},{F=3}-{^{2}S_{1/2}},{F=2}$ transition and
+${^{2}P_{3/2}},{F=4}-{^{2}S_{1/2}},{F=3}$ transition are measured to be
+759.905401(10) THz and 756.547403(10) THz, respectively. The hyperfine
+structure constants of aluminum atoms are determined and compared with
+previously reported measurement results and theoretical calculation. Reasonable
+agreement is found for the magnetic dipole constant (A constant), while the
+electric quadrupole constant (B constant) has a large deviation.",1802.02749v1
+2018-03-08,Quantum Interactions of Topological Solitons from Electrodynamics,"The Casimir energy for the classically stable configurations of the
+topological solitons in 2D quantum antiferromagnets is studied by performing
+the path-integral over quantum fluctuations. The magnon fluctuation around the
+solitons saturating the Bogomol'nyi inequality may be viewed as a charged
+scalar field coupled with an effective magnetic field induced by the solitons.
+The magnon-soliton couping is closely related to the Pauli Hamiltonian, with
+which the effective action is calculated by adapting the worldline formulation
+of the derivative expansion for the 2+1d quantum electrodynamics in an external
+field. The resulting framework is more flexible than the conventional
+scattering analysis based on the Dashen-Hasslacher-Neveu formula. We obtain a
+short-range attractive well and a universal long-range $1/r$-type repulsive
+potential between two solitons.",1803.03181v5
+2018-04-18,Comparison of Sensitivity and Low Frequency Noise Contributions in GMR and TMR Spin Valve Sensors with a Vortex State Free Layer,"Magnetoresistive spin valve sensors based on the giant- (GMR) and tunnelling-
+(TMR) magnetoresisitve effect with a flux-closed vortex state free layer design
+are compared by means of sensitivity and low frequency noise. The vortex state
+free layer enables high saturation fields with negligible hysteresis, making it
+attractive for applications with a high dynamic range. The measured GMR devices
+comprise lower pink noise and better linearity in resistance but are less
+sensitive to external magnetic fields than TMR sensors. The results show a
+comparable detectivity at low frequencies and a better performance of the TMR
+minimum detectable field at frequencies in the white noise limit.",1804.06940v1
+2018-05-01,On The Design of a Novel Finite-Time Nonlinear Extended State Observer for Class of Nonlinear Systems with Mismatch Disturbances and Uncertainties,"In this paper, a novel finite - time Nonlinear Extended State Observer
+(NLESO) is proposed and employed in Active Disturbance Rejection Control (ADRC)
+to stabilize a nonlinear system against system's uncertainties and
+discontinuous disturbances using output feedback technique. The first task was
+to aggregate the uncertainties, disturbances, and any other undesired
+nonlinearities in the system into a single term called the ""generalized
+disturbance"". Consequently, the ESO estimates the generalized disturbance and
+cancel it from the input channel in an online fashion. A peaking phenomenon
+that existed in Linear ESO (LESO) has been reduced significantly by adopting a
+saturation - like nonlinear function in the proposed Nonlinear ESO (NLESO).
+Stability analysis of the NLEO is studied using finite - time Lyapunov theory,
+and the comparisons are presented over simulations on Permanent Magnet DC
+(PMDC) motor to confirm the effectiveness of the proposed observer concerning
+LESO.",1805.00257v4
+2018-05-25,Extreme magnetoresistance and Shubnikov-de Haas oscillations in ferromagnetic DySb,"The electronic structures of a representative rare earth monopnictide (i.e.,
+DySb) under high magnetic field (i.e., in the ferromagnetic state) are studied
+from both experimental and theoretical aspects. A non-saturated extremely large
+positive magnetoresistance (XMR) is observed (as large as 3.7*10^4% at 1.8 K
+and 38.7 T), along with the Shubnikov-de Haas oscillations that are well
+reproduced by our first principles calculations. Three possible origins of XMR
+are examined. Although a band inversion is found theoretically, suggesting that
+DySb might be topologically nontrivial, it is deeply underneath the Fermi
+level, which rules out a topological nature of the XMR. The total densities of
+electron-like and hole-like carriers are not fully compensated, showing that
+compensation is unlikely to account for the XMR. The XMR is eventually
+understood in terms of high mobility that is associated with the steep linear
+bands. This discovery is important to the intensive studies on the XMR of rare
+earth monopnictides.",1805.09998v2
+2018-06-08,Quantum dynamics of disordered spin chains with power-law interactions,"We use extensive numerical simulations based on matrix product state methods
+to study the quantum dynamics of spin chains with strong on-site disorder and
+power-law decaying ($1/r^\alpha$) interactions. We focus on two spin-$1/2$
+Hamiltonians featuring power-law interactions: Heisenberg and XY and
+characterize their corresponding long-time dynamics using three distinct
+diagnostics: decay of a staggered magnetization pattern $I(t)$, growth of
+entanglement entropy $S(t)$, and growth of quantum Fisher information $F_Q(t).$
+For sufficiently rapidly decaying interactions $\alpha>\alpha_c$ we find a
+many-body localized phase, in which $I(t)$ saturates to a non-zero value,
+entanglement entropy grows as $S(t)\propto t^{1/\alpha}$, and Fisher
+information grows logarithmically. Importantly, entanglement entropy and Fisher
+information do not scale the same way (unlike short range interacting models).
+The critical power $\alpha_c$ is smaller for the XY model than for the
+Heisenberg model.",1806.03339v1
+2018-06-21,Detection and characterization of Many-Body Localization in Central Spin Models,"We analyze a disordered central spin model, where a central spin interacts
+equally with each spin in a periodic one dimensional random-field Heisenberg
+chain. If the Heisenberg chain is initially in the many-body localized (MBL)
+phase, we find that the coupling to the central spin suffices to delocalize the
+chain for a substantial range of coupling strengths. We calculate the phase
+diagram of the model and identify the phase boundary between the MBL and
+ergodic phase. Within the localized phase, the central spin significantly
+enhances the rate of the logarithmic entanglement growth and its saturation
+value. We attribute the increase in entanglement entropy to a non-extensive
+enhancement of magnetization fluctuations induced by the central spin. Finally,
+we demonstrate that correlation functions of the central spin can be utilized
+to distinguish between MBL and ergodic phases of the 1D chain. Hence, we
+propose the use of a central spin as a possible experimental probe to identify
+the MBL phase.",1806.08316v1
+2018-06-22,Half moons are pinch points with dispersion,"""Pinch points,"" singular features observed in (quasi-)elastic neutron
+scattering, are a widely discussed hallmark of spin liquids with an emergent
+gauge symmetry. Much less attention has been paid to ""half moons,"" distinctive
+crescent patterns at finite energy, which have been observed in experiments on
+a number of pyrochlore magnets, and in a wide range of model calculations. Here
+we unify these two phenomena within a single framework, paying particular
+attention to the case of ordered, or field-saturated states, where pinch points
+and half moons can be found in bands of excitations above a gap. We find that
+half moons are nothing other than pinch points inscribed on a dispersing band.
+Molecular dynamics simulations of the kagome lattice antiferromagnet are used
+to explore how these bands evolve into the ground state and excitations of a
+classical spin liquid. We explicitly demonstrate that this theory can reproduce
+the pinch points and half moons observed in Nd$_2$Zr$_2$O$_7$.",1806.08520v2
+2018-07-30,Ultralow-temperature thermal conductivity of Pr2Ir2O7: a metallic spin-liquid candidate with quantum criticality,"The frustrated pyrochlore iridate Pr$_2$Ir$_2$O$_7$ was proposed as a
+metallic quantum spin liquid located at a zero-field quantum critical point.
+Here we present the ultralow-temperature thermal conductivity measurements on
+the Pr$_2$Ir$_2$O$_7$ single crystals to detect possible exotic excitations. In
+zero field, the thermal conductivity shows a dramatic suppression above a
+characteristic temperature $T_s \approx$ 0.12 K. With increasing field, $T_s$
+increases and the thermal conductivity tends to saturate above $H$ = 5 T. The
+Wiedemann-Franz law is verified at high fields and inferred at zero field. It
+suggests the normal behavior of electrons at the quantum critical point, and
+the absence of mobile fermionic magnetic excitations. The strong suppression of
+thermal conductivity is attributed to the scattering of phonons by the spin
+system, likely the fluctuating spins. These results shed new light on the
+microscopic description on this novel compound.",1807.11185v1
+2018-10-10,First-principles investigation of the effect of substitution and surface adsorption on magnetostrictive properties of Fe-Ga alloys,"Materials with large magnetostriction are widely used in sensors, actuators,
+micro electromechanical systems, and energy-harvesters. Binary Fe-Ga alloys
+(Galfenol) are the most promising rare-earth-free candidates combining numerous
+advantages such as low saturation magnetic field (~200 Oe), excellent ductility
+and low cost, while further improving their performance is imperative for
+practical applications. Using density functional theory calculation, we report
+results of the effect of substituting small amount of additional elements X
+(eg. X = Ag, Pd and Cu) on magnetostriction of Fe-Ga alloys, and find that it
+may double the magnetostriction with a substitutional percentage of only 1.6%.
+Moreover, adsorbents with high chemical activity (eg. O or Os atoms) may affect
+the surface energy of different face-orientations of Fe-Ga alloys, indicating
+proper surface treatments are necessary to tune the alignment of Fe-Ga grains
+to achieve better performance. These results may be helpful to further optimize
+the magnetostrictive properties of Fe-Ga alloys for device applications.",1810.04708v1
+2018-10-13,Noise in the helical edge channel anisotropically coupled to a local spin,"We calculate the frequency-dependent shot noise in the edge states of a
+two-dimensional topological insulator coupled to a magnetic impurity with spin
+$S=1/2$ of arbitrary anisotropy. If the anisotropy is absent, the noise is
+purely thermal at low frequencies, but tends to the Poissonian noise of the
+full current $I$ at high frequencies. If the interaction only flips the
+impurity spin but conserves those of electrons, the noise at high voltages
+$eV\gg T$ is frequency-independent. Both the noise and the backscattering
+current $I_{bs}$ saturate at voltage-independent values. Finally, if the
+Hamiltonian contains all types of non-spin-conserving scattering, the noise at
+high voltages becomes frequency-dependent again. At low frequencies, its ratio
+to $2eI_{bs}$ is larger than 1 and may reach 2 in the limit $I_{bs}\to 0$. At
+high frequencies it tends to 1.",1810.05831v1
+2018-12-03,The Landau-Lifshitz-Bloch equation for domain wall motion in antiferromagnets,"In this work, we derive the Landau-Lifshitz-Bloch equation accounting for the
+multi-domain antiferromagnetic (AFM) lattice at finite temperature, in order to
+investigate the domain wall (DW) motion, the core issue for AFM spintronics.
+The continuity equation of the staggered magnetization is obtained using the
+continuum approximation, allowing an analytical calculation on the domain wall
+dynamics. The influence of temperature on the static domain wall profile is
+investigated, and the analytical calculations reproduce well earlier numerical
+results on temperature gradient driven saturation velocity of the AFM domain
+wall, confirming the validity of this theory. Moreover, it is worth noting that
+this theory could be also applied to dynamics of various wall motions in an AFM
+system. The present theory represents a comprehensive approach to the domain
+wall dynamics in AFM materials, a crucial step toward the development of AFM
+spintronics.",1812.00759v2
+2018-12-06,Generic machine identification and maximum efficiency operation of induction machines,"This paper proposes an advanced machine identification method for inverter
+fed squirrel-cage induction machines, based on steady-state measurements in the
+rotor flux oriented dq-reference frame. The measured machine maps are used to
+extract maximum efficiency per torque (MEPT) look-up tables, which guarantee
+the maximum achievable efficiency in every operating point. Furthermore, it is
+shown, that comparable results can be achieved, even without a torque sensor.
+The main advantage of the described method is its generality, which implicitly
+covers magnetic saturation, iron losses and other nonlinear effects that are
+typically neglected or approximated by complex models. Finally, the
+efficiencies of V/Hz and field-oriented control (FOC) are calculated for
+different speeds and load torques, allowing for quantitative assessment and
+comparison of both methods.",1812.02431v1
+2018-12-10,Electromagnetic turbulence suppression by energetic particle driven modes,"In recent years, a strong reduction of plasma turbulence in the presence of
+energetic particles has been reported in a number of magnetic confinement
+experiments and corresponding gyrokinetic simulations. While highly relevant to
+performance predictions for burning plasmas, an explanation for this primarily
+nonlinear effect has remained elusive so far. A thorough analysis finds that
+linearly marginally stable energetic particle driven modes are excited
+nonlinearly, depleting the energy content of the turbulence and acting as an
+additional catalyst for energy transfer to zonal modes (the dominant turbulence
+saturation channel). Respective signatures are found in a number of simulations
+for different JET and ASDEX Upgrade discharges with reduced transport levels
+attributed to energetic ion effects.",1812.03755v1
+2018-12-12,Room-temperature ferromagnetic insulating state in highly cation-ordered epitaxial oxide double perovskite,"Ferromagnetic insulators (FMIs) are one of the most important components in
+developing dissipationless electronic and spintronic devices. However, since
+ferromagnetism generally accompanies metallicity, FMIs are innately rare to
+find in nature. Here, novel room-temperature FMI films are epitaxially
+synthesized by deliberate control of the ratio of two B-site cations in the
+double perovskite Sr2FeReO6. In contrast to the known ferromagnetic metallic
+phase in stoichiometric Sr2FeReO6, a FMI state with a high Curie temperature
+(Tc~400 K) and a large saturation magnetization (MS~1.8 {\mu}B/f.u.) is found
+in highly cation-ordered Fe-rich phases. The stabilization of the FMI state is
+attributed to the formation of extra Fe3+-Fe3+ and Fe3+-Re6+ bonding states,
+which originate from the excess Fe. The emerging FMI state by controlling
+cations in the epitaxial oxide perovskites opens the door to developing novel
+oxide quantum materials & heterostructures.",1812.04953v1
+2019-01-05,Nonlinear excitation of geodesic acoustic mode by toroidal Alfvén eigenmodes and impact on plasma performance,"Spontaneous nonlinear excitation of geodesic acoustic mode (GAM) by toroidal
+Alfv\'en eigenmode (TAE) is investigated using nonlinear gyrokinetic theory. It
+is found that, the nonlinear decay process depends on thermal ion \beta value.
+Here, \beta is the plasma thermal to magnetic pressure ratio. In the low-\beta
+limit, TAE decays into a GAM and a lower TAE sideband in the toroidicity
+induced shear Alfv\'en wave continuous spectrum gap; while in the high-\beta
+limit, TAE decays into a GAM and a propagating kinetic TAE in the continuum.
+Both cases are investigated for the spontaneous decay conditions. The nonlinear
+saturation levels of both GAM and daughter wave are derived. The corresponding
+power balance and wave particle power transfer to thermal plasma are computed.
+Implications on thermal plasma heating are also discussed.",1901.01366v1
+2019-01-08,Fabrication of yttrium-iron-garnet/Pt multilayers for the longitudinal spin Seebeck effect,"For longitudinal spin Seebeck effect (LSSE) devices, a multilayer structure
+comprising ferromagnetic and nonmagnetic layers is expected to improve their
+thermoelectric power. In this study, we developed the fabrication method for
+alternately stacked yttrium-iron-garnet (YIG)/Pt multilayer films on a
+gadolinium gallium garnet (GGG) (110) substrate, GGG/[YIG(49 nm)/Pt(4 nm)]$_n$
+($n =$ 1 - 5) based on room-temperature sputtering and $ex$-$situ$
+post-annealing method and we evaluated their structural and LSSE properties.
+The fabricated [YIG/Pt]$_n$ samples show flat YIG/Pt interfaces and almost
+identical saturation magnetization $M_{\rm s}$, although they contain
+polycrystalline YIG layers on Pt layers as well as single-crystalline YIG
+layers on GGG. In the samples, we observed clear LSSE signals and found that
+the LSSE thermoelectric power factor (PF) increases monotonically with
+increasing $n$; the PF of the [YIG/Pt]$_5$ sample is enhanced by a factor of
+$\sim 28$ compared to that of [YIG/Pt]$_1$. This work may provide a guideline
+for developing future multilayerbased LSSE devices.",1901.02129v1
+2019-02-20,Surface-induced positive planar Hall effect in topological Kondo insulator SmB6 microribbons,"Whether the surface states in SmB6 are topological is still a critical issue
+in the field of topological Kondo insulators. In the magneto-transport study of
+single crystalline SmB6 microribbons, we have revealed a positive planar Hall
+effect (PHE), the amplitude of which increases dramatically with decreasing
+temperatures but saturates below 5 K. This positive PHE is ascribed to the
+surface states of SmB6 and expected to arise from the anisotropy in lifting the
+topological protection from back-scattering by the in-plane magnetic field,
+thus suggesting the topological nature of surface states in SmB6. On the
+contrary, a negative PHE is observed for the bulk states at high temperatures,
+which is almost three orders of magnitudes weaker than the surface-induced
+positive PHE.",1902.07364v1
+2019-04-15,Evolution of three-dimensional Relativistic Ion Weibel Instability: Competition with Kink Instability,"In this paper, we report our recent findings on the relativistic Weibel
+instability and its nonlinear saturation by performing numerical simulations of
+collisionless plasmas. Analysis of the obtained numerical results revealed that
+the nonlinear phase of the Weibel instability can be described by
+characteristic phases based on the Weibel filaments' current density in terms
+of particle and Alfv\'en limit currents. We also analyzed the relativistic kink
+instability based on the energy principle in the magnetohydrodynamic (MHD)
+regime, and found that the Weibel filaments do not suffer from the kink-type
+instability in the MHD regime up to 1000 $\omega_{p,i}^{-1}$. This finding
+allowed a magnetic field to be sustained by relativistic Weibel instability
+that was stable enough to be a seed for MHD dynamos.",1904.07008v1
+2019-05-08,Charge density wave and large non-saturating magnetoresistance in YNiC$_2$ and LuNiC$_2$,"We report a study of physical properties of two quasi-low dimensional metals
+YNiC$_2$ and LuNiC$_2$ including the investigation of transport,
+magnetotransport, galvanomagnetic and specific heat properties. In YNiC$_2$ we
+reveal two subsequent transitions associated with the formation of weakly
+coupled charge density wave at $T_{CDW}$ = 318 K, and its locking in with the
+lattice at $T_1$ = 275 K. These characteristic temperatures follow the
+previously proposed linear scaling with the unit cell volume, demonstrating its
+validity extended beyond the lanthanide-based $R$NiC$_2$. We also find that, in
+the absence of magnetic ordering able to interrupt the development of charge
+density wave, the Fermi surface nesting leads to opening of small pockets,
+containing high mobility carriers. This effect gives rise to substantial
+enhancement of magnetoresistance, reaching 470 % for YNiC$_2$ and 50 % for
+LuNiC$_2$ at $T$ = 1.9 K and $B$ = 9 T.",1905.02919v1
+2019-05-27,Magnetohydrodynamics in graphene: shear and Hall viscosities,"Viscous phenomena are the hallmark of the hydrodynamic flow exhibited by
+Dirac fermions in clean graphene at high enough temperatures. We report a
+quantitative calculation of the electronic shear and Hall viscosities in
+graphene based on the kinetic theory combined with the renormalization group
+providing a unified description at arbitrary doping levels and non-quantizing
+magnetic fields. At charge neutrality, the Hall viscosity vanishes, while the
+field-dependent shear viscosity decays from its zero-field value saturating to
+a nonzero value in classically strong fields. Away from charge neutrality, the
+field-dependent viscosity coefficients tend to agree with the semiclassical
+expectation.",1905.11424v2
+2019-05-30,Possibility of $ρ$ Meson Condensation in Neutron Star: Unified Approach of Chiral SU(3) Model and QCD Sum Rules,"In the present work the conjunction of chiral SU(3) model with QCD sum rules
+is employed to explore the possibility of $\rho$ meson condensation in neutron
+stars. The quark and gluon condensates in terms of which the in-medium masses
+of $\rho$ mesons can be expressed are calculated using the chiral SU(3) model
+in the charge neutral matter which is relevant for neutron stars. It is
+observed that condition of $\rho$ meson condensation is satisfied for the
+density of about 7$\rho_{0}$, where $\rho_{0}$ is the nuclear saturation
+density. In the end, a brief qualitative discussion of the magnetic field is
+also involved to check out for the further possibility of $\rho$ meson
+condensation.",1905.13184v1
+2019-06-19,Bosonic topological insulator intermediate state in the superconductor-insulator transition,"A low-temperature intervening metallic regime arising in the two-dimensional
+superconductor-insulator transition challenges our understanding of electronic
+fluids. Here we develop a gauge theory revealing that this emergent anomalous
+metal is a bosonic topological insulator where bulk transport is suppressed by
+mutual statistics interactions between out-of-condensate Cooper pairs and
+vortices and the longitudinal conductivity is mediated by symmetry-protected
+gapless edge modes. We explore the magnetic-field-driven
+superconductor-insulator transition in a niobium titanium nitride device and
+find marked signatures of a bosonic topological insulator behavior of the
+intervening regime with the saturating resistance. The observed
+superconductor-anomalous metal and insulator-anomalous metal dual phase
+transitions exhibit quantum Berezinskii-Kosterlitz-Thouless criticality in
+accord with the gauge theory.",1906.07969v2
+2019-07-08,Knot spectrum of turbulence,"Streamlines, vortex lines and magnetic flux tubes in turbulent fluids and
+plasmas display a great amount of coiling, twisting and linking, raising the
+question as to whether their topological complexity (continually created and
+destroyed by reconnections) can be quantified. In superfluid helium, the
+discrete (quantized) nature of vorticity can be exploited to associate to each
+vortex loop a knot invariant called the Alexander polynomial whose degree
+characterizes the topology of that vortex loop. By numerically simulating the
+dynamics of a tangle of quantum vortex lines, we find that this quantum
+turbulence always contains vortex knots of very large degree which keep
+forming, vanishing and reforming, creating a distribution of topologies which
+we quantify in terms of a knot spectrum and its scaling law. We also find
+results analogous to those in the wider literature, demonstrating that the
+knotting probability of the vortex tangle grows with the vortex length, as for
+macromolecules, and saturates above a characteristic length, as found for
+tumbled strings.",1907.03420v1
+2019-08-03,Coherent control of Optical limiting in atomic systems,"Generation and control of the reverse saturable absorption (RSA) and optical
+limiting (OL) are investigated in a four-level Y-type quantum system. It is
+demonstrated that the applied laser fields induce the RSA and it can be
+coherently controlled by either intensity or frequency of the applied laser
+fields. The effect of the static magnetic field on the induced RSA is studied
+and we obtain that it has a constructive role in determining the intensity
+range in which the OL is established in the system. In addition, we find that
+the OL threshold can be decreased either by increasing the length of the medium
+or by getting the atomic system denser. Finally, Z-scan technique is presented
+to confirm our theoretical results. The proposed scheme can be used in
+designing the coherent optical limiters with controllable threshold and
+intensity range of OL.",1908.01186v1
+2019-08-21,Lyapunov growth in quantum spin chains,"The Ising spin chain with longitudinal and transverse magnetic fields is
+often used in studies of quantum chaos, displaying both chaotic and integrable
+regions in its parameter space. However, even at a strongly chaotic point this
+model does not exhibit Lyapunov growth of the commutator squared of spin
+operators, as this observable saturates before exponential growth can manifest
+itself (even in situations where a spatial suppression factor makes the initial
+commutator small). We extend this model from the spin 1/2 Ising model to higher
+spins, demonstrate numerically that a window of exponential growth opens up for
+sufficiently large spin, and extract a quantity which corresponds to a notion
+of a Lyapunov exponent. In the classical infinite-spin limit, we identify and
+compute the appropriate classical analogue of the commutator squared, and show
+that the corresponding exponent agrees with the infinite-spin limit extracted
+from the quantum spin chain.",1908.08059v3
+2019-09-10,Highly Mobile Carriers in a Candidate of Quasi-Two-Dimensional Topological Semimetal AuTe$_2$Br,"We report the crystal and electronic structures of a non-centrosymmetric
+quasi-two-dimensional (2D), candidate of topological semimetal AuTe2Br. The
+Fermi surface of this layered compound consists of 2D-like, topological trivial
+electron and non-trivial hole pockets which host a Dirac cone along the kz
+direction. Our transport measurements on the single crystals show highly
+anisotropic, compensated low-density electrons and holes, both of which exhibit
+ultrahigh mobility at a level of 10^5cm^2V^-1s^-1 at low temperature. The
+highly mobile, compensated carriers lead a non-saturated, parabolic
+magnetoresistance as large as 3*10^5 in single-crystalline AuTe2Br in a
+magnetic field up to 58 T.",1909.04296v1
+2019-10-01,Unique Dirac and Triple point fermiology in simple transition metals and their binary alloys,"Noble metal surfaces (Au, Ag and Cu etc.) have been extensively studied for
+the Shockley type surface states (SSs). Very recently, some of these Shockley
+SSs have been understood from the topological consideration, with the knowledge
+of global properties of electronic structure. In this letter, we show the
+existence of Dirac like excitations in the elemental noble metal Ru, Re and Os
+based on symmetry analysis and first principle calculations. The unique SSs
+driven Fermi arcs have been investigated in details for these metals. Our
+calculated SSs and Fermi arcs are consistent with the previous transport and
+photo-emission results. We attribute these Dirac excitation mediated Fermi arc
+topology to be the possible reasons behind several existing transport
+anomalies, such as large non-saturating magneto resistance, anomalous Nernst
+electromotive force and its giant oscillations, magnetic breakdown etc. We
+further show that the Dirac like excitations in these elemental metal can
+further be tuned to three component Fermionic excitations, using symmetry
+allowed alloy mechanism.",1910.00196v2
+2019-10-23,Magnon crystallization in the kagome lattice antiferromagnet,"We present numerical evidence for the crystallization of magnons below the
+saturation field at non-zero temperatures for the highly frustrated spin-half
+kagome Heisenberg antiferromagnet. This phenomenon can be traced back to the
+existence of independent localized magnons or equivalently flat-band
+multi-magnon states. We present a loop-gas description of these localized
+magnons and a phase diagram of this transition, thus providing information for
+which magnetic fields and temperatures magnon crystallization can be observed
+experimentally. The emergence of a finite-temperature continuous transition to
+a magnon-crystal is expected to be generic for spin models in dimension $D>1$
+where flat-band multi-magnon ground states break translational symmetry.",1910.10448v3
+2019-11-26,Pressure effect on multiferroic CuBr2,"The quasi-1D spin chain compound CuBr2 has been found to be multiferroic
+below TN (73.5K) under ambient pressure, in which the spontaneous electric
+polarization is induced by emerging spin spiral ordering propagating along
+b-axis. Herein we studied the hydrostatic pressure effect on the magnetic,
+dielectric and structural properties of CuBr2. The multiferroic transition
+temperature is greatly enhanced under hydrostatic pressure. From ambient to
+about 1 GPa (the limit of our homemade apparatus), TN increases unprecedentedly
+by more than 20K, and no sign of saturation is observed in our experiments.
+Meanwhile the corresponding dielectric loss keeps rather low (<<0.1). Further
+synchrotron-based high pressure X-ray diffraction measurements reveal that
+there is no pressure-induced structural phase transition in CuBr2 up to 10.2
+GPa. Upon increasing pressure, the b-axis (along the spin chain) just changes
+slowly while transverse a- and c- axis parameters shrink much more greatly.
+Pressure greatly reduces the separation between spin chains and enhance the
+inter-chain coupling interactions in CuBr2, which results in the giant increase
+of multiferroic critical temperate. Our finding suggests a new effective way to
+improve the known multiferroic systems towards practical high temperature
+multiferroicity.",1911.11453v1
+2020-01-03,Extremely large linear magnetoresistance in Antimony crystal,"In this letter we report the observation of extremely large non-saturating
+linear magnetoresistance (MR) in Antimony(Sb) crystal. An extremely large
+magnetoresistance (XMR) of 43000% at 2K and large unsaturating MR$\sim\ $70% at
+room temperature is observed at the magnetic field of 9T. Hall measurements
+reveal a very high mobility $\sim\ $3.8 x 10$^{4}$ cm$^{2}$/Vs of charge
+carriers and strong temperature dependence of carrier concentration and
+mobility. The respective scaling of MR and crossover field (B$_{c}$) from
+quadratic to linear MR with mobility and inverse of mobility describes the
+classical origin of large linear MR in this crystal as suggested by Parish and
+Littlewood (PL) model for disordered systems.",2001.00778v1
+2020-01-13,Spin-1/2 $XX$ chain in a transverse field with regularly alternating $g$-factors: Static and dynamic properties,"We consider the spin-1/2 isotropic $XY$ chain in an external magnetic field
+directed along $z$ axis with periodically varying $g$-factors. To reveal the
+effects of regularly alternating $g$-factors, we calculate various static and
+dynamic equilibrium quantities in the ground state and at finite temperatures.
+We demonstrate that because of the regularly alternating $g$-factors the
+saturation field may disappear and the field dependence of the susceptibility
+in the ground state has additional logarithmic singularity at zero field.
+Moreover, the zero-field susceptibility has a logarithmic singularity as $T\to
+0$. Furthermore, the dynamic structure factors exhibit much more structure in
+the ""wave vector -- frequency"" plane that can be traced out to modifications of
+the two-fermion excitation continua which exclusively determine
+$S_{zz}(\kappa,\omega)$ and dominate the properties of $S_{xx}(\kappa,\omega)$.
+We discuss what changes can be observed in dynamic experiments on the
+corresponding substances.",2001.04159v3
+2020-02-10,Structural and magneto-transport studies of iron intercalated Bi2Se3 single crystals,"A detailed investigation on the structural and magneto-transport properties
+of iron intercalated Bi2Se3 single crystals have been presented. The x-ray
+diffraction and Raman studies confirm the intercalation of Fe in the van der
+Waals gaps between the layers. The electrical resistivity of the compounds
+decreases upon intercalation, and Hall resistivity shows the enhancement of the
+charge carriers upon intercalation. The magnetoresistance shows the
+non-saturating linear behavior at higher magnetic field and low temperature.
+Intercalation of Fe increases the onset of the linear magnetoresistance
+behavior, indicating the reduction in quantum effects. The Kohler scaling
+employed on the magnetoresistance data indicates single scattering process for
+all these compounds in the measured temperature range of 3- 300 K.",2002.03609v2
+2020-03-30,Reduction of the sign problem near $T=0$ in quantum Monte Carlo simulations,"Building on a recent investigation of the Shastry-Sutherland model [S. Wessel
+et al., Phys. Rev. B 98, 174432 (2018)], we develop a general strategy to
+eliminate the Monte Carlo sign problem near the zero temperature limit in
+frustrated quantum spin models. If the Hamiltonian of interest and the
+sign-problem-free Hamiltonian---obtained by making all off-diagonal elements
+negative in a given basis---have the same ground state and this state is a
+member of the computational basis, then the average sign returns to one as the
+temperature goes to zero. We illustrate this technique by studying the
+triangular and kagome lattice Heisenberg antiferrromagnet in a magnetic field
+above saturation, as well as the Heisenberg antiferromagnet on a modified
+Husimi cactus in the dimer basis. We also provide detailed appendices on using
+linear programming techniques to automatically generate efficient directed loop
+updates in quantum Monte Carlo simulations.",2003.13356v1
+2020-04-02,Soft x-ray absorption of thin films detected using substrate luminescence: A performance analysis,"X-ray absorption spectroscopy of thin films is central to a broad range of
+scientific fields, and is typically detected using indirect techniques. X-ray
+excited optical luminescence (XEOL) from the sample's substrate is one such
+detection method, in which the luminescence signal acts as an effective
+transmission measurement through the film. This detection method has several
+advantages that make it versatile compared to others, in particular for
+insulating samples or when a probing depth larger than 10nm is required. In
+this work we present a systematic performance analysis of this method with the
+aim of providing guidelines for its advantages and pitfalls, enabling a wider
+use of this method by the thin film community. We compare and quantify the
+efficiency of XEOL from a range of commonly used substrates. Our measurements
+demonstrate the equivalence between XEOL and x-ray transmission measurements
+for thin films. Moreover, we show the applicability of XEOL to magnetic studies
+by employing XMCD sum rules with XEOL-generated data. Lastly, we demonstrate
+that above a certain thickness XEOL shows a saturation-like effect, which can
+be modelled and corrected for.",2004.01047v1
+2020-07-14,Nonlinear mechanisms that regulate the solar cycle amplitude,"The solar magnetic activity cycle has an amplitude that varies within a wide
+but limited range of values. This implies that there are nonlinear mechanisms
+that prevent runaway solutions. The purpose of this paper is to propose
+observable nonlinear mechanisms in the framework of the Babcock-Leighton-type
+dynamo. Sunspot emergences show systematic properties that strong cycles tend
+to have higher mean latitudes and lower tilt angle coefficients. We use the
+surface flux transport model to investigate the effect of these systematic
+properties on the expected final total dipolar moment, i.e. cancellation plus
+generation of dipole moment by a whole solar cycle. We demonstrate that the
+systematic change in latitude has similar nonlinear feedback on the solar cycle
+(latitudinal quenching) as tilt does (tilt quenching). Both forms of quenching
+lead to the expected final total dipolar moment being enhanced for weak cycles
+and being saturated to a nearly constant value for normal and strong cycles.
+This explains observed long-term solar cycle variability, e.g., the
+Gnevyshev-Ohl rule, which, in turn, justifies the nonlinear mechanisms inherent
+in the Babcock-Leighton-type dynamo.",2007.07069v2
+2020-07-29,Shape of solar cycles and mid-term solar activity oscillations,"The evolution of the solar activity comprises, apart from the well-known
+11-year cycle, various temporal scales ranging from months up to the secondary
+cycles known as mid-term oscillations. Its nature deserves a physical
+explanation. In this work, we consider the 5-to-6 year oscillations as derived
+both from sunspot and from solar magnetic dipole time series. Using the solar
+dynamo model, we deduced that these variations may be a manifestation of the
+dynamo nonlinearities and non-harmonic shape of the solar activity cycles. We
+conclude that the observed mid-term oscillations are related to the nonlinear
+saturation of the dynamo processes in the solar interior.",2007.14779v2
+2020-08-13,On the mechanism of polarised metrewave stellar emission,"Two coherent radio emission mechanisms operate in stellar coronae: plasma
+emission and cyclotron emission. They directly probe the electron density and
+magnetic field strength respectively. Most stellar radio detections have been
+made at cm-wavelengths where it is often not possible to uniquely identify the
+emission mechanism, hindering the utility of radio observations in probing
+coronal conditions. In anticipation of stellar observations from a suite of
+sensitive low-frequency ($\nu\sim 10^2\,{\rm MHz}$) radio telescopes, here I
+apply the general theory of coherent emission in non-relativistic plasma to the
+low-frequency case. I consider the recently reported low-frequency emission
+from dMe flare stars AD Leo and UV Ceti and the quiescent star GJ 1151 as test
+cases. My main conclusion is that unlike the cm-wave regime, for reasonable
+turbulence saturation regimes, the emission mechanism in metre-wave
+observations ($\nu\sim 10^2\,{\rm MHz}$) can often be identified based on the
+observed brightness temperature, emission duration and polarisation fraction. I
+arrive at the following heuristic: M-dwarf emission that is $\gtrsim
+\,$hour-long with $\gtrsim 50\%$ circular polarised fraction at brightness
+temperatures of $\gtrsim 10^{12}\,$K at $\sim 100\,{\rm MHz}$ in canonical
+M-dwarfs strongly favours a cyclotron maser interpretation.",2008.05707v1
+2020-09-13,Electric field control of disorder-tunable superconductivity and the emergence of quantum metal at an oxide interface,"We report on an extraordinary field effect of the superconducting
+LaAlO3/KTaO3(111) interface with Tc ~2 K. By applying a gate voltage (VG)
+across KTaO3, the interface can be continuously tuned from superconducting into
+insulating states, yielding a dome-shaped Tc-VG dependence. The electric gating
+has only a minor effect on carrier density as evidenced in the Hall-effect
+measurement, while it changes spatial profile of the carriers in the interface,
+hence the carrier's disorder level significantly. As temperature is decreased,
+the resistance saturates at lowest temperature in both superconducting and
+insulating sides, despite an initial dramatic dropping or increasing, which
+suggests an emergence of quantum metallic state associated with failed
+superconductor and/or fragile insulator. A VG-modulation of the
+magnetic-field-driven superconductor to insulator quantum phase transition
+reveals a non-universal criticality.",2009.05896v1
+2020-10-19,Gyrokinetic investigation of Alfvén instabilities in the presence of turbulence,"The nonlinear dynamics of beta-induced Alfv\'en Eigenmodes (BAE) driven by
+energetic particles (EP) in the presence of ion-temperature-gradient (ITG)
+turbulence is investigated, by means of selfconsistent global gyrokinetic
+simulations and analytical theory. A tokamak magnetic equilibrium with large
+aspect ratio and reversed shear is considered. A previous study of this
+configuration has shown that the electron species plays an important role in
+determining the nonlinear saturation level of a BAE in the absence of
+turbulence [A. Biancalani, et al., J. Plasma Phys. (2020)]. Here, we extend the
+study to a turbulent plasma. The EPs are found modify the heat fluxes by
+introducing energy at the large spatial scales, mainly at the toroidal mode
+number of the dominant BAE and its harmonics. In this regime, BAEs are found to
+carry a strong electron heat flux. The feed-back of the global relaxation of
+the temperature profiles induced by the BAE, and on the turbulence dynamics, is
+also discussed.",2010.09516v1
+2020-10-25,Criticality-enhanced quantum sensing in ferromagnetic Bose-Einstein condensates: role of readout measurement and detection noise,"We theoretically investigate estimation of the control parameter in a
+ferromagnetic Bose-Einstein condensate near second order quantum phase
+transitions. We quantify sensitivity by quantum and classical Fisher
+information and using the error-propagation formula. For these different
+metrics, we find the same, beyond-standard-quantum-limit (SQL) scaling with
+atom number near critical points, and SQL scaling away from critical points. We
+find that both depletion of the $m_f=0$ Zeeman sub-level and transverse
+magnetization provide signals of sufficient quality to saturate the sensitivity
+scaling. To explore the effect of experimental imperfections, we study the
+scaling around criticality at nonzero temperature and with nonzero detection
+noise. Our results suggest the feasibility of sub-SQL sensing in ferromagnetic
+condensates with current experimental capabilities.",2010.13133v1
+2020-11-12,Anomalous Hall effect and negative longitudinal magnetoresistance in half-Heusler topological semimetal candidates TbPtBi and HoPtBi,"Half-Heusler compounds have attracted significant attention because of their
+topologically non-trivial electronic structure, which leads to unusual electron
+transport properties. We thoroughly investigated the magnetotransport
+properties of high-quality single crystals of two half-Heusler phases, TbPtBi
+and HoPtBi, in pursuit of the characteristic features of topologically
+non-trivial electronic states. Both studied compounds are characterized by the
+giant values of transverse magnetoresistance with no sign of saturation in
+magnetic field up to 14 T. HoPtBi demonstrates the Shubnikov-de Haas effect
+with two principal frequencies, indicating a complex Fermi surface; the
+extracted values of carrier effective masses are rather small, $0.18\,m_e$ and
+$0.27\,m_e$. The investigated compounds exhibit negative longitudinal
+magnetoresistance and anomalous Hall effect, which likely arise from a nonzero
+Berry curvature. Both compounds show strongly anisotropic magnetoresistance,
+that in HoPtBi exhibits a butterfly-like behavior.",2011.06290v1
+2020-11-13,Interaction-induced topological superconductivity in antiferromagnet-superconductor junctions,"We predict that junctions between an antiferromagnetic insulator and a
+superconductor provide a robust platform to create a one-dimensional
+topological superconducting state. Its emergence does not require the presence
+of intrinsic spin-orbit coupling nor non-collinear magnetism, but arises solely
+from repulsive electronic interactions on interfacial solitonic states. We
+demonstrate that a topological superconducting state is generated by repulsive
+interactions at arbitrarily small coupling strength, and that the size of the
+topological gap rapidly saturates to the one of the parent trivial
+superconductor. Our results put forward antiferromagnetic insulators as a new
+platform for interaction-driven topological superconductivity.",2011.06990v3
+2020-11-27,Experimental Detection of the Correlation Rényi Entropy in the Central Spin Model,"We propose and experimentally measure an entropy that quantifies the volume
+of correlations among qubits. The experiment is carried out on a nearly
+isolated quantum system composed of a central spin coupled and initially
+uncorrelated with 15 other spins. Due to the spin-spin interactions,
+information flows from the central spin to the surrounding ones forming
+clusters of multi-spin correlations that grow in time. We design a nuclear
+magnetic resonance experiment that directly measures the amplitudes of the
+multi-spin correlations and use them to compute the evolution of what we call
+correlation R\'enyi entropy. This entropy keeps growing even after the
+equilibration of the entanglement entropy. We also analyze how the saturation
+point and the timescale for the equilibration of the correlation R\'enyi
+entropy depend on the system size.",2011.13948v1
+2020-12-11,Compositional effect on auto-oscillation behavior of Ni100-xFex/Pt spin Hall nano-oscillators,"We demonstrate the compositional effect on the magnetodynamic and
+auto-oscillations properties of Ni100-xFex/Pt (x= 10 to 40) nanoconstriction
+based spin Hall nano-oscillators. Using spin-torque ferromagnetic resonance
+(ST-FMR) performed on microstrips, we measure a significant reduction in both
+damping and spin Hall efficiency with increasing Fe content, which lowers the
+spin pumping contribution. The strong compositional effect on spin Hall
+efficiency is primarily attributed to the increased saturation magnetization in
+Fe-rich devices. As a direct consequence, higher current densities are required
+to drive spin-wave auto-oscillations at higher microwave frequencies in Fe-rich
+nano-constriction devices. Our results establish the critical role of the
+compositional effect in engineering the magnetodynamic and auto-oscillation
+properties of spin Hall devices for microwav eand magnonic applications.",2012.06121v2
+2021-01-11,Magnetotransport in overdoped La$_{2-x}$Sr$_x$CuO$_4$: a Fermi liquid approach,"Recently, several experiments on La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) challenged
+the Fermi liquid picture for overdoped cuprates, and stimulated intensive
+debates [1]. In this work, we study the magnetotransport phenomena in such
+systems based on the Fermi liquid assumption. The Hall coefficient $R_H$ and
+magnetoresistivity $\rho_{xx}$ are investigated near the van Hove singularity
+$x_{\tiny\text{VHS}}\approx0.2$ across which the Fermi surface topology changes
+from hole- to electron-like. Our main findings are: (1) $R_H$ depends on the
+magnetic field $B$ and drops from positive to negative values with increasing
+$B$ in the doping regime $x_{\tiny\text{VHS}}<x\lesssim0.3$; (2) $\rho_{xx}$
+grows up as $B^2$ at small $B$ and saturates at large $B$, while in the
+transition regime a ""nearly linear"" behavior shows up. Our results can be
+further tested by future magnetotransport experiments in the overdoped LSCO.",2101.03741v1
+2021-03-03,Near-Room Temperature Ferromagnetic Insulating State in Highly Distorted LaCoO2.5 with CoO5 Square Pyramids,"Dedicated control of oxygen vacancies is an important route to
+functionalizing complex oxide films. It is well-known that tensile strain
+significantly lowers the oxygen vacancy formation energy, whereas compressive
+strain plays a minor role. Thus, atomically reconstruction by extracting oxygen
+from a compressive-strained film is challenging. Here we report an unexpected
+LaCoO2.5 phase with a zigzag-like oxygen vacancy ordering through annealing a
+compressive-strained LaCoO3 in vacuum. The synergetic tilt and distortion of
+CoO5 square pyramids with large La and Co shifts are quantified using scanning
+transmission electron microscopy. The large in-plane expansion of CoO5 square
+pyramids weaken the crystal-field splitting and facilitated the ordered
+high-spin state of Co2+, which produces an insulating ferromagnetic state with
+a Curie temperature of ~284 K and a saturation magnetization of ~0.25
+{\mu}B/Co. These results demonstrate that extracting targeted oxygen from a
+compressive-strained oxide provides an opportunity for creating unexpected
+crystal structures and novel functionalities.",2103.02100v1
+2021-03-11,Spin Nernst Effect of Antiferromagnetic Magnons in the Presence of Spin Diffusion,"Magnon spin Nernst effect was recently proposed as an intrinsic effect in
+antiferromagnets, where spin diffusion and boundary spin transmission have been
+ignored. However, diffusion processes are essential to convert a bulk spin
+current into boundary spin accumulation, which determines the spin injection
+rate into detectors through imperfect transmission. We formulate a diffusive
+theory to describe the detection of magnon spin Nernst effect with boundary
+conditions reflecting real device geometry. Thanks to the spin diffusion
+effect, the output signals in both electronic and optical detection grow
+rapidly with an increasing system size in the transverse dimension, which
+eventually saturate. Counterintuitively, the measurable signals are even
+functions of magnetic field, yielding optical detection more favorable than
+electronic detection.",2103.06870v3
+2021-04-26,Insensitivity of the complexity rate of change to the conformal anomaly and Lloyd's bound as a possible renormalization condition,"We determine the effect on the computational complexity of a conformal
+anomaly using the Complexity=Action prescription of the gauge/gravity
+correspondence. To allow the involvement of said anomaly, we extend previous
+studies to include arbitrary values for the anisotropic parameter and the
+magnetic field respectively on the Mateos-Trancanelli and the D'Hoker-Kraus
+holographic models. Our main result is that the rate of change of the
+computational complexity is independent of the conformal anomaly in both cases.
+In addition, this allows us to also show that, if so desired, the saturation of
+Lloyd's bound at infinite time can be used as a renormalization condition.",2104.12796v2
+2021-05-14,An energy harvesting technology controlled by ferromagnetic resonance,"We have successfully demonstrated electrical charging using the electromotive
+force (EMF) generated in a ferromagnetic metal (FM) film under ferromagnetic
+resonance (FMR). In the case of Ni80Fe20 films, electrical charge due to the
+EMF generated under FMR can be accumulated in a capacitor; however, the amount
+of charge is saturated well below the charging limit of the capacitor.
+Meanwhile in the case of Co50Fe50, electrical charge generated under FMR can be
+accumulated in a capacitor and the amount of charge increases linearly with the
+FMR duration time. The difference between the Ni80Fe20 and Co50Fe50 films is
+due to the respective magnetic field ranges for the FMR excitation. When the FM
+films were in equivalent thermal states during FMR experiments, Co50Fe50 films
+could maintain FMR in a detuned condition, while Ni80Fe20 films were outside
+the FMR excitation range. The EMF generation phenomenon in an FM film under FMR
+can be used an energy harvesting technology by appropriately controlling the
+thermal conditions of the FM film.",2105.06606v1
+2021-05-24,A non-perturbative study of bulk photovoltaic effect enhanced by an optically induced phase transition,"Solid systems with strong correlations and interactions under light
+illumination have the potential for exhibiting interesting bulk photovoltaic
+behavior in the non-perturbative regime, which has remained largely unexplored
+in the past theoretical studies. We investigate the bulk photovoltaic response
+of a perovskite manganite with strongly coupled electron-spin-lattice dynamics,
+using real-time simulations performed with a tight-binding model. The transient
+changes in the band structure and the photoinduced phase transitions, emerging
+from spin and phonon dynamics, result in a nonlinear current versus intensity
+behavior beyond the perturbative limit. The current rises sharply across a
+photoinduced magnetic phase transition, which later saturates at higher light
+intensities due to excited phonon and spin modes. The predicted peak
+photoresponsivity is orders of magnitude higher than other known ferroelectric
+oxides such as BiFeO$_3$. We disentangle phonon-and spin-assisted components to
+the ballistic photocurrent, showing that they are comparable in magnitude. Our
+results illustrate a promising alternative way for controlling and optimizing
+the bulk photovoltaic response through the photoinduced phase transitions in
+strongly-correlated systems.",2105.11310v1
+2021-05-27,Integrable quantum many-body sensors for AC field sensing,"Quantum sensing is inevitably an elegant example of the supremacy of quantum
+technologies over their classical counterparts. One of the desired endeavors of
+quantum metrology is AC field sensing. Here, by means of analytical and
+numerical analysis, we show that integrable many-body systems can be exploited
+efficiently for detecting the amplitude of an AC field. Unlike the conventional
+strategies in using the ground states in critical many-body probes for
+parameter estimation, we only consider partial access to a subsystem. Due to
+the periodicity of the dynamics, any local block of the system saturates to a
+steady state which allows achieving sensing precision well beyond the classical
+limit, almost reaching the Heisenberg bound. We associate the enhanced quantum
+precision to closing of the Floquet gap, resembling the features of quantum
+sensing in the ground state of critical systems. We show that the proposed
+protocol can also be realized in near-term quantum simulators, e.g. ion-traps,
+with a limited number of qubits. We show that in such systems a simple block
+magnetization measurement and a Bayesian inference estimator can achieve very
+high precision AC field sensing.",2105.13507v2
+2021-06-16,Self-dual solitons in a Born-Infeld baby Skyrme model,"We show the existence of self-dual (topological) solitons in a gauged version
+of the baby Skyrme model in which the Born-Infeld term governs the gauge field
+dynamics. The successful implementation of the Bogomol'nyi-Prasad-Sommerfield
+formalism provides a lower bound for the energy and the respective self-dual
+equations whose solutions are the solitons saturating such a limit. The energy
+lower bound (Bogomol'nyi bound) is proportional to the topological charge of
+the Skyrme field and therefore quantized. In contrast, the total magnetic flux
+is a nonquantized quantity. Furthermore, the model supports three types of
+self-dual solitons profiles: the first describes compacton solitons, the second
+follows a Gaussian decay law, and the third portrays a power-law decay.
+Finally, we perform numerical solutions of the self-dual equations and depicted
+the soliton profiles for different values of the parameters controlling the
+nonlinearity of the model.",2106.08546v1
+2021-08-31,Slowdown of interpenetration of two counterpropagating plasma slab due to collective effects,"The nonlinear evolution of electromagnetic instabilities driven by the
+interpenetration of two $e^-\,e^+$ plasma clouds is explored using {\it ab
+initio} kinetic plasma simulations. We show that the plasma clouds slow down
+due to both oblique and Weibel generated electromagnetic fields, which deflect
+the particle trajectories, transferring bulk forward momentum into transverse
+momentum and thermal velocity spread. This process causes the flow velocity
+$v_{inst}$ to decrease approximately by a factor of $\sqrt{1/3}$ in a time
+interval $\Delta t_{\alpha B} \omega_p \sim c/(v_{fl}\sqrt{\alpha_B})$, where
+$\alpha_B$ is the magnetic equipartition parameter determined by the non-linear
+saturation of the instabilities, $v_{fl}$ is the initial flow speed, and
+$\omega_p$ is the plasma frequency. For the $\alpha_B$ measured in our
+simulations, $\Delta t_{\alpha B}$ is close to $10 \times$ the instability
+growth time. We show that as long as the plasma slab length $L > v_{fl} \Delta
+t_{\alpha B}$, the plasma flow is expected to slow down by a factor close to
+$1/\sqrt{3}$.",2109.00023v1
+2021-09-02,Force Correlations in Disordered Magnets,"We present a proof of principle for the validity of the functional
+renormalization group, by measuring the force correlations in Barkhausen-noise
+experiments. Our samples are soft ferromagnets in two distinct universality
+classes, differing in the range of spin interactions, and the effects of eddy
+currents. We show that the force correlations have a universal form predicted
+by the functional renormalization group, distinct for short-range and
+long-range elasticity, and mostly independent of eddy currents. In all cases
+correlations grow linearly at small distances, as in mean-field models, but in
+contrast to the latter are bounded at large distances. As a consequence,
+avalanches are anti-correlated. We derive bounds for these anti-correlations,
+which are saturated in the experiments, showing that the multiple domain walls
+in our samples effectively behave as a single wall.",2109.01197v3
+2021-10-26,Topological phase transitions in strongly correlated systems: application to Co$_3$Sn$_2$S$_2$,"The topological transition in the strongly correlated half-metallic
+ferromagnetic compound Co$_3$Sn$_2$S$_2$ from Weyl semimetal (including chiral
+massless fermions) to a non-magnetic state is treated. This transition goes
+with a change in topological invariant, and is accompanied by a non-topological
+transition from saturated ferromagnetic to paramagnetic state, the minority
+Fermi surface being transformed from ghost (hidden) to real. A corresponding
+description is given in terms of slave fermion representation for the effective
+narrow-band Hubbard model. The system Co$_3$Sn$_2$S$_2$ provides a bright
+example of coexistence of non-trivial topology and strong low-dimensional
+ferromagnetism. A comparison is performed with other compounds where
+frustrations result in formation of a correlated paramagnetic state.",2110.13709v1
+2021-11-05,Transverse momentum broadening in real-time lattice simulations of the glasma,"The study of jets in heavy-ion collisions provides important information
+about the interaction of partons with the medium that they traverse. The seeds
+of jets are highly energetic partons, which are produced from hard scatterings
+during the collision event. As such, they are affected by all different stages
+of the medium's time evolution, including the glasma, which is the
+pre-equilibrium precursor state of the quark-gluon plasma. Here we report on
+our numerical lattice simulations of partons traversing the boost-invariant,
+non-perturbative glasma as created at the early stages of collisions at RHIC
+and LHC. We find that partons quickly accumulate transverse momentum up to the
+saturation momentum during the glasma stage. Furthermore, we observe an
+interesting anisotropy in transverse momentum broadening of partons with larger
+broadening in the rapidity than in the azimuthal direction. Its origin can be
+related to correlations among the longitudinal color-electric and
+color-magnetic flux tubes in the initial state of the glasma. We compare these
+observations to the semi-analytic results obtained by a weak-field
+approximation, where we also find such an anisotropy in a parton's transverse
+momentum broadening.",2111.03400v1
+2021-11-26,Damping of Pseudo-Goldstone Fields,"Approximate symmetries abound in Nature. If these symmetries are also
+spontaneously broken, the would-be Goldstone modes acquire a small mass, or
+inverse correlation length, and are referred to as pseudo-Goldstones. At
+nonzero temperature, the effects of dissipation can be captured by
+hydrodynamics at sufficiently long scales compared to the local equilibrium.
+Here we show that in the limit of weak explicit breaking, locality of
+hydrodynamics implies that the damping of pseudo-Goldstones is completely
+determined by their mass and diffusive transport coefficients. We present many
+applications: superfluids, QCD in the chiral limit, Wigner crystal and density
+wave phases in the presence of an external magnetic field or not, nematic
+phases and (anti-)ferromagnets. For electronic density wave phases,
+pseudo-Goldstone damping generates a contribution to the resistivity
+independent of the strength of disorder, which can have a linear temperature
+dependence provided the associated diffusivity saturates a bound. This is
+reminiscent of the phenomenology of strange metal high $T_c$ superconductors,
+where charge density waves are observed across the phase diagram.",2111.13459v2
+2021-12-07,On transverse momentum broadening in real-time lattice simulations of the glasma and in the weak-field limit,"In these proceedings, we report on our numerical lattice simulations of
+partons traversing the boost-invariant, non-perturbative glasma as created at
+the early stages of collisions at RHIC and LHC. Since these highly energetic
+partons are produced from hard scatterings during heavy-ion collisions, they
+are already affected by the first stage of the medium's time evolution, the
+glasma, which is the pre-equilibrium precursor state of the quark-gluon plasma.
+We find that partons quickly accumulate transverse momentum up to the
+saturation momentum during the glasma stage. Moreover, we observe an
+interesting anisotropy in transverse momentum broadening of partons with larger
+broadening in the rapidity than in the azimuthal direction. Its origin can be
+related to correlations among the longitudinal color-electric and
+color-magnetic flux tubes in the initial state of the glasma. We compare these
+observations to the semi-analytic results obtained by a weak-field
+approximation, where we also find such an anisotropy in a parton's transverse
+momentum broadening.",2112.03883v1
+2021-12-30,Digital Rock Typing DRT Algorithm Formulation with Optimal Supervised Semantic Segmentation,"Each grid block in a 3D geological model requires a rock type that represents
+all physical and chemical properties of that block. The properties that
+classify rock types are lithology, permeability, and capillary pressure.
+Scientists and engineers determined these properties using conventional
+laboratory measurements, which embedded destructive methods to the sample or
+altered some of its properties (i.e., wettability, permeability, and porosity)
+because the measurements process includes sample crushing, fluid flow, or fluid
+saturation. Lately, Digital Rock Physics (DRT) has emerged to quantify these
+properties from micro-Computerized Tomography (uCT) and Magnetic Resonance
+Imaging (MRI) images. However, the literature did not attempt rock typing in a
+wholly digital context. We propose performing Digital Rock Typing (DRT) by: (1)
+integrating the latest DRP advances in a novel process that honors digital rock
+properties determination, while; (2) digitalizing the latest rock typing
+approaches in carbonate, and (3) introducing a novel carbonate rock typing
+process that utilizes computer vision capabilities to provide more insight
+about the heterogeneous carbonate rock texture.",2112.15068v2
+2022-01-21,"Anomalous metals: from ""failed superconductor"" to ""failed insulator""","Resistivity saturation is found on both superconducting and insulating sides
+of an ""avoided"" magnetic-field-tuned superconductor-to-insulator transition
+(H-SIT) in a two-dimensional In/InO$_x$ composite, where the anomalous metallic
+behaviors cut off conductivity or resistivity divergence in the
+zero-temperature limit. The granular morphology of the material implies a
+system of Josephson junctions (JJ) with a broad distribution of Josephson
+coupling E$_J$ and charging energy E$_C$ , with a H-SIT determined by the
+competition between E$_J$ and E$_C$ . By virtue of self-duality across the true
+H-SIT, we invoke macroscopic quantum tunneling effects to explain the
+temperature-independent resistance where the ""failed superconductor"" side is a
+consequence of phase fluctuations and the ""failed insulator"" side results from
+charge fluctuations. While true self-duality is lost in the avoided transition,
+its vestiges are argued to persist, owing to the incipient duality of the
+percolative nature of the dissipative path in the underlying random JJ system.",2201.08801v1
+2022-01-23,Differential configurational complexity and phase transitions of the BPS solutions in the O(3)-sigma model,"Using a spherically symmetric ansatz, we show that the Chern-Simons
+O(3)-sigma model with a logarithmic potential admits topological solutions.
+This result is quite interesting since the Gausson-type logarithmic potential
+only predicted topological solutions in $(1+1)$D models. To accomplish our
+goal, the Bogomol'nyi-Prasad-Sommerfield (BPS) method is used, to saturate the
+energy and obtain the BPS equations. Next, we show by the numerical method is
+the graphical results of the topological fields, as well as, the magnetic field
+behavior that generates a flux given by $\Phi_{flux}=-\mathcal{Q}/\kappa$ and
+the energy density of the structures of vortices. On the other hand, we
+evaluate the measure of the differential configurational complexity (DCC) of
+the topological structures, by considering the energy density of the vortex.
+This analysis is important because it will provide us with information about
+the possible phase transitions associated with the localized structures and it
+shows that our model only supports the one-phase transition.",2201.09303v2
+2022-01-26,Nonlinear magnon polaritons,"We experimentally and theoretically demonstrate that nonlinear spin-wave
+interactions suppress the hybrid magnon-photon quasiparticle or ""magnon
+polariton"" in microwave spectra of an yttrium iron garnet film detected by an
+on-chip split-ring resonator. We observe a strong coupling between the Kittel
+and microwave cavity modes in terms of an avoided crossing as a function of
+magnetic fields at low microwave input powers, but a complete closing of the
+gap at high powers. The experimental results are well explained by a
+theoretical model including the three-magnon decay of the Kittel magnon into
+spin waves. The gap closure originates from the saturation of the ferromagnetic
+resonance above the Suhl instability threshold by a coherent back reaction from
+the spin waves.",2201.10889v2
+2022-02-07,Wall Ion Loss Reduction by Acceleration Zone Shifting in Anode-Layer Hall Thruster,"In this study, wall ion loss and erosion rate are evaluated in the RAIJIN
+thruster. The novelty of this work is the detailed analysis of measured
+guard-ring (metallic channel wall) current, which enables a fast evaluation of
+the wall ion loss and erosion rate. The current-voltage characteristics of the
+guard-ring current indicate that the sheath on the guard rings is in the ion
+saturation regime and that the guard-ring current can be used as a wall ion
+flux indicator. The experimental results demonstrate that the wall ion loss can
+be significantly reduced in the magnetic configuration of RAIJIN thrusters with
+the acceleration zone shifting.",2202.02921v1
+2022-03-08,Interplay between nonlinear spectral shift and nonlinear damping of spin waves in ultrathin YIG waveguides,"We use the phase-resolved imaging to directly study the nonlinear
+modification of the wavelength of spin waves propagating in 100-nm thick,
+in-plane magnetized YIG waveguides. We show that, by using moderate microwave
+powers, one can realize spin waves with large amplitudes corresponding to
+precession angles in excess of 10 degrees and nonlinear wavelength variation of
+up to 18 percent in this system. We also find that, at large precession angles,
+the propagation of spin waves is strongly affected by the onset of nonlinear
+damping, which results in a strong spatial dependence of the wavelength. This
+effect leads to a spatially dependent controllability of the wavelength by the
+microwave power. Furthermore, it leads to the saturation of nonlinear spectral
+shift's effects several micrometers away from the excitation point. These
+findings are important for the development of nonlinear, integrated spin-wave
+signal processing devices and can be used to optimize their characteristics.",2203.04018v1
+2022-03-17,Multiparameter quantum metrology in the Heisenberg Limit regime: many repetition scenario vs. full optimization,"We discuss the Heisenberg limit in the multiparameter metrology within two
+different paradigms -- the one, where the measurement is repeated many times
+(so the Cram\'er-Rao bound is guaranteed to be asymptotically saturable) and
+the second one, where all the resources are allocated into one experimental
+realization (analyzed with the mimimax approach). We investigate the potential
+advantage of measuring all the parameter simultaneously compared to estimating
+them individually, while spending the same total amount of resources. We show
+that in general the existence of such an advantage, its magnitude and
+conditions under which it occurs depends on which of the two paradigms has been
+chosen. In particular, for the problem of magnetic field sensing using $N$
+entangled spin-$1/2$, we show that the predictions based purely on the
+Cram\'er-Rao formalism may be overly pessimistic in this matter -- the minimax
+approach reveals the superiority of measuring all the parameters jointly
+whereas the Cram\'er-Rao approach indicates lack of such an advantage.",2203.09541v3
+2022-04-06,Critical quantum thermometry and its feasibility in spin systems,"In this work, we study temperature sensing with finite-sized strongly
+correlated systems exhibiting quantum phase transitions. We use the quantum
+Fisher information (QFI) approach to quantify the sensitivity in the
+temperature estimation, and apply a finite-size scaling framework to link this
+sensitivity to critical exponents of the system around critical points. We
+numerically calculate the QFI around the critical points for two
+experimentally-realizable systems: the spin-1 Bose-Einstein condensate and the
+spin-chain Heisenberg XX model in the presence of an external magnetic field.
+Our results confirm finite-size scaling properties of the QFI. Furthermore, we
+discuss experimentally-accessible observables that (nearly) saturate the QFI at
+the critical points for these two systems.",2204.02734v2
+2022-04-13,Core localized alpha-channeling via low frequency Alfven mode generation in reversed shear scenarios,"A novel channel for fuel ions heating in tokamak core plasma is proposed and
+analyzed using nonlinear gyrokinetic theory. The channel is achieved via
+spontaneous decay of reversed shear Alfven eigenmode (RSAE) into low frequency
+Alfven modes (LFAM), which then heat fuel ions via collisionless ion Landau
+damping. The conditions for RSAE spontaneous decay are investigated, and the
+saturation level and the consequent fuel ion heating rate are also derived. The
+channel is expected to be crucial for future reactors operating under reversed
+shear configurations, where fusion alpha particles are generated in the tokamak
+core where the magnetic shear is typically reversed, and there is a dense RSAE
+spectrum due to the small alpha particle characteristic dimensionless orbits.",2204.06169v1
+2022-07-01,Pulse Frequency Fluctuations of Persistent Accretion Powered Pulsars,"In this study, we examine the long term torque noise fluctuations of
+persistent Xray binaries Her X-1, Vela X-1, GX 301-2, CEN X-3, 4U 1538-53, OAO
+1657-415 and 4U 1626-67 using the historical pulse frequency measurements
+provided by CGRO/BATSE and Fermi/GBM. We find that known disk-fed sources
+exhibit $1/\omega^{2}$ red noise component in their power density spectra which
+is saturated over long timescales. On the other hand, wind-fed sources form a
+clear white noise component and the wind-fed sources with occasional transient
+disk formation imprint $1/\omega$ type flicker noise. We discuss their
+long-term timing noise properties based on the models to describe the power
+density spectrum of pulse frequency derivative fluctuations in terms of
+monochromatic and colored noise processes. Furthermore, we investigate the
+relation between measured timing noise strengths and other independently
+measured physical parameters. Despite the low number of sample sources, we
+suggest that noise strengths of these sources are correlated with their
+luminosities and uncorrelated with their magnetic fields strengths, implying
+that the dominant noise generating mechanism is accretion",2207.00248v2
+2022-08-19,Triggering of tearing instability by impurity radiation through resistive interchange reversal in a tokamak,"Recent MHD simulations find that the reversal of the local resistive
+interchange parameter $D_R$ from negative to positive due to impurity radiation
+cooling is able to trigger the resistive tearing mode growth in a tokamak above
+a threshold in impurity level. A layer of perturbed Pfirsch-Schl\""{u}ter
+current density and resistivity are also induced by the impurity radiation,
+which further govern the tearing mode growth and saturation in the nonlinear
+stage. The impurity threshold and the tearing mode growth strongly depend on
+the parallel thermal conductivity, and such a dependence derives from the
+impact on $D_R$ of the fast parallel thermal equilibration along the helical
+magnetic field lines.",2208.09161v1
+2022-09-08,Dominance of Electron-Magnon Scattering in Itinerant Ferromagnet Fe3GeTe2,"Fe3GeTe2 is a 2-dimensional van der Waals material exhibiting itinerant
+ferromagnetism upto 230 K. Here, we study aspects of scattering mechanism in
+Fe3Ge2Te2 single crystals via resistivity, magneto-transport and Hall effect
+measurements. The quadratic temperature dependence of electrical resistivity
+below the Curie temperature hints towards the dominance of electron-magnon
+scattering. A non-saturating positive magnetoresistance (MR) is observed at low
+temperatures when the magnetic field is applied parallel to the sample plane.
+The linear negative MR at high fields for T < TC corroborates to the
+suppression in magnon population due to the damping of spin waves. In the high
+temperature regime T > TC,MR can be described by the scattering from spin
+fluctuations using the model described by Khosla and Fischer. Isothermal Hall
+resistivity curves unveil the presence of anomalous Hall resistivity.
+Correlation between MR and side jump mechanism further reveals that the
+electron-magnon scattering is responsible for the side jump contribution to the
+anomalous Hall effect. Our results provide a clear understanding of the role of
+electron-magnon scattering on anomalous Hall effect that rules out its origin
+to be the topological band structure.",2209.03555v1
+2022-09-13,Self-dual compact gauged baby skyrmions in a continuous medium,"We investigate the existence of self-dual configurations in the restricted
+gauged baby Skyrme model enlarged with a $Z_2$--symmetry, which introduces a
+real scalar field. For such a purpose, we implement the Bogomol'nyi procedure
+that provides a lower bound for the energy and the respective self-dual
+equations whose solutions saturate such a bound. Aiming to solve the self-dual
+equations, we specifically focused on a class of topological structures called
+compacton. We obtain the corresponding numerical solutions within two distinct
+scenarios, each defined by a scalar field, allowing us to describe different
+magnetic media. Finally, we analyze how the compacton profiles change when
+immersed in each medium.",2209.06309v2
+2022-10-24,Amorphous and polycrystalline routes towards a chiral spin liquid,"We show that a chiral spin liquid spontaneously emerges in partially
+amorphous, polycrystalline, or ion-irradiated Kitaev materials. In these
+systems, time-reversal symmetry is broken spontaneously due to a non-zero
+density of plaquettes with an odd number of edges, $n_{odd}$. This mechanism
+opens a sizeable gap, at small $n_{odd}$ compatible with that of typical
+amorphous materials and polycrystals, and which can alternatively be induced by
+ion-irradiation. We find that the gap is proportional to $n_{odd}$, saturating
+at $n_{odd}\sim 40\%$. Using exact diagonalization, we find that the chiral
+spin liquid is approximately as stable to Heisenberg interactions as Kitaev's
+honeycomb spin liquid model. Our results open up a significant number of
+non-crystalline systems where chiral spin liquids can emerge without external
+magnetic fields.",2210.13548v2
+2022-12-22,Magnetoelasticity-driven phase inversion of ultrafast spin precession in NixFe100-x thin films,"We present strong evidences for the deterministic role of magnetoelasticity
+in ultrafast spin dynamics of ferromagnetic NixFe100-x alloy films. Without a
+change in the crystal structure, we observed sudden Pi-phase inversion of the
+spin precession in the range of x = 87.0 - 97.5. In addition, it was found that
+the phase was continuously changed and reversed its sign by varying the pump
+fluence. These cannot be explained simply by temperature dependence of
+magnetocrystalline, demagnetizing, and Zeeman fields which have been
+conventionally considered so far in describing the spin dynamics. Through the
+temperature- and composition-dependent simulations adding the magnetoelastic
+field generated from the lattice thermal strain, we revealed that the
+conventional and magnetoelastic fields were competing around x = 95.3, where
+the spin dynamics showed the largest phase shift. For analytic understanding,
+we further show that the temperature-dependent interplay of the Curie
+temperature, saturation magnetization, and magnetostriction, which are
+demonstrated to be the most important macroscopic parameters, determines the
+ultrafast spin dynamics. Our extensive study emphasizes that magnetoelasticity
+is the key ingredient for fully understanding the driving mechanism of
+ultrafast spin dynamics.",2212.11852v1
+2022-12-25,Quantum Geometric Oscillations in Two-Dimensional Flat-Band Solids,"Two-dimensional van der Waals heterostructures can be engineered into
+artificial superlattices that host flat bands with significant Berry curvature
+and provide a favorable environment for the emergence of novel electron
+dynamics. In particular, the Berry curvature can induce an oscillating
+trajectory of an electron wave packet transverse to an applied static electric
+field. Though analogous to Bloch oscillations, this novel oscillatory behavior
+is driven entirely by quantum geometry in momentum space instead of band
+dispersion. While the orbits of Bloch oscillations can be localized by
+increasing field strength, the size of the geometric orbits saturates to a
+nonzero plateau in the strong-field limit. In non-magnetic materials, the
+geometric oscillations are even under inversion of the applied field, whereas
+the Bloch oscillations are odd, a property that can be used to distinguish
+these two co-existing effects.",2212.12852v2
+2023-01-24,Validation and traceability of miniaturized multi-parameter cluster of radiosondes used for atmospheric observations,"In this work we designed and developed a cluster of light expendable
+radiosondes that can float passively inside warm clouds to study their
+micro-physical processes. This involves the tracking of both saturated and
+unsaturated turbulent air parcels. The aim of this new kind of observation
+system is to obtain Lagrangian statistics of the intense turbulence inside warm
+clouds and of the lower intensity turbulence that is typical of the air
+surrounding such clouds. Each radiosonde in a cluster includes an electronic
+board, which is mounted onto a small, biodegradable balloon filled with a
+mixture of helium and air. The cluster is able to float inside clouds for a few
+hours and to measure air temperature, pressure, humidity and the associated
+position, velocity, acceleration and magnetic field readings of each radiosonde
+along their trajectory.",2301.09928v3
+2023-02-06,The out-of-plane magnetoresistance in a Van der Waals thin film of WTe2,"We report the magneto-transport measurements of thin film devices of the
+topological Weyl semimetal WTe2 with the applied current along and vertical to
+the in-plane directions. The device is composed of a Van der Waals thin film of
+WTe2 sandwiched between top and bottom Au electrodes.At low temperatures, we
+found a large unsaturated in-plane magnetoresistance and a saturated
+out-of-plane magnetoresistance when the external magnetic fields are applied
+perpendicular to the plane. By analysis of Shubnikov-de Haas oscillations, one
+oscillation peak is found in the out-of-plane magnetoresistance, in contrast to
+four oscillation peaks in the in-plane magnetoresistance.Our work provides new
+insight into the origin of the unsaturated magnetoresistance in WTe2 and may
+inspire non-planar engineering to reach higher integration in spintronics.",2302.02645v1
+2023-03-15,Rare observation of spin-gapless semiconducting characteristics and related band topology of quaternary Heusler alloy CoFeMnSn,"In this paper, we report the theoretical investigation and experimental
+realization of a new spin-gapless semiconductor (SGSs) compound CoFeMnSn
+belonging to the family of quaternary Heusler alloys. Through the use of
+several ground-state energy calculations, the most stable structure has been
+identified. Calculations of the spin-polarized band structure in optimized
+structure's reveals the SGS nature of the compound. The compound form in an
+ordered crystal structure and exhibit a high ferromagnetic transition
+temperature (T$_{\rm C}$ = 560 K), making the material excellent for room
+temperature applications. Adherence of saturation magnetization to the
+Slater-Pauling rule, together with the nearly temperature-independent
+resistivity, conductivity, and carrier concentration of the compound in the
+temperature regime 5$-$300 K along with the low value of anomalous Hall
+conductivity (AHC) further confirms the SGS nature. Theoretical calculations
+also reveal the robustness of the SGS state due to lattice contraction and one
+can obtain a high value of intrinsic AHC using hole doping. Combined SGS and
+topological properties of the compound make CoFeMnSn suitable for spintronics
+and magneto-electronics devices.",2303.08589v2
+2023-04-28,A numerical study of bounds in the correlations of fractional quantum Hall states,"We numerically compute the guiding center static structure factor $\bar S(\bf
+k)$ of various fractional quantum Hall (FQH) states to
+$\mathcal{O}\left((k\ell)^6\right)$ where $k$ is the wavenumber and $\ell$ is
+the magnetic length. Employing density matrix renormalization group on an
+infinite cylinder of circumference $L_y$, we study the two-dimensional limit
+using $L_y/\xi \gg 1$, where $\xi$ is the correlation length. The main findings
+of our work are: 1) the ground states that deviate away from the ideal
+conformal block wavefunctions, do not saturate the Haldane bound, and 2) the
+coefficient of $O\left((k\ell)^6\right)$ term appears to be bounded above by a
+value predicted by field theories proposed in the literature. The first finding
+implies that the graviton mode is not maximally chiral for experimentally
+relevant FQH states.",2304.14991v4
+2023-06-25,Photon echo and fractional excitation lensing of $S=1/2$ XY spin chain,"We study numerically the two-dimensional coherent spectrum (2DCS) of the
+Tomonaga-Luttinger liquid hosted by the $S=1/2$ XY spin chain. The 2DCS
+characterizes the system's third order nonlinear magnetic response triggered by
+three pulses, separated successively by the delay time and the waiting time. It
+exhibits a photon echo signal resulting from a lensing process of the
+fractional excitations: A pair of photon-excited fractional excitations,
+initially moving apart, reverse their direction of motion, and annihilate each
+other. In the XY chain, the nonlinearity in the dispersion relation of the
+Jordan-Wigner fermions leads to the dispersion of the fractional excitation
+wave packets and thereby suppresses lensing. The magnitude of the echo signal
+decreases exponentially with increasing delay time. The decay rate scales with
+the temperature $T$ as $T^n$ at low temperature, where $n$ is the leading order
+of the Jordan-Wigner fermion dispersion, and as $T$ at high temperature. By
+contrast, as the waiting time increases, the magnitude of the echo signal
+saturates, reflecting the integrability of the system. Our results illustrate
+the effectiveness of the 2DCS in detecting subtle dynamical properties of
+optical excitations in spin chains.",2306.14220v1
+2023-07-08,Superconducting Gap Structure of Filled Skutterudite LaOs$_4$As$_{12}$ Compound through $μ$SR Investigations,"Filled skutterudite compounds have gained attention recently as an innovative
+platforms for studying intriguing low-temperature superconducting properties.
+Regarding the symmetry of the superconducting gap, contradicting findings from
+several experiments have been made for LaRu$_{4}$As$_{12}$ and its
+isoelectronic counterpart, LaOs$_{4}$As$_{12}$. In this vein, we report
+comprehensive bulk and microscopic results on LaOs$_{4}$As$_{12}$ utilizing
+specific heat analysis and muon-spin rotation/relaxation ($\mu$SR)
+measurements. Bulk superconductivity with $T_C$ = 3.2 K was confirmed by heat
+capacity. The superconducting ground state of the filled-skutterudite
+LaOs$_{4}$As$_{12}$ compound is found to have two key characteristics:
+superfluid density exhibits saturation type behavior at low temperature, which
+points to a fully gapped superconductivity with gap value of $2\Delta/k_BT_C$ =
+3.26; additionally, the superconducting state does not show any sign of
+spontaneous magnetic field, supporting the preservation of time-reversal
+symmetry. These results open the door for the development of La-based
+skutterudites as special probes for examining the interplay of single- and
+multiband superconductivity in classical electron-phonon systems.",2307.03946v1
+2023-07-10,Core localized alpha-channeling via low frequency Alfven mode generation in reversed shear scenarios,"A novel channel for fuel ions heating in tokamak core plasma is proposed and
+analyzed using nonlinear gyrokinetic theory. The channel is achieved via
+spontaneous decay of reversed shear Alfv\'en eigenmode (RSAE) into low
+frequency Alfv\'en modes (LFAM), which then heat fuel ions via collisionless
+ion Landau damping. The conditions for RSAE spontaneous decay are investigated,
+and the saturation level and the consequent fuel ion heating rate are also
+derived. The channel is expected to be crucial for future reactors operating
+under reversed shear configurations, where fusion alpha particles are generated
+in the tokamak core where the magnetic shear is typically reversed, and there
+is a dense RSAE spectrum due to the small alpha particle characteristic
+dimensionless orbits.",2307.04388v1
+2023-07-21,Evidence for Pseudogap Phase in Cerium Superhydrides: CeH$_{10}$ and CeH$_9$,"Polyhydride superconductors have been shown to possess metallic properties
+with a Bardeen-Cooper-Schrieffer-type superconducting ground state. Here, we
+provide evidence for unconventional transport associated with a pseudogap phase
+in cubic cerium superhydride CeH$_{10}$ ($\textit{T}$$_C$ = 116 K) at pressure
+of 115-125 GPa. A large negative magnetoresistance in the non-superconducting
+state below 90 K, quasi $\textit{T}$-linear electrical resistance, and a
+sign-change of its temperature dependence mark the emergence of this phase. We
+studied the magnetic phase diagrams and the upper critical fields
+$\textit{B}$$_{C2}$(T) of CeH$_{10}$, CeH$_9$, and CeD$_9$ in pulsed fields up
+to 70 T. $\textit{B}$$_{C2}$(T) of CeH$_9$ and CeD$_9$ exhibits pronounced
+saturation at low temperatures in accordance with the
+Werthamer-Helfand-Hohenberg model, whereas CeH$_{10}$ stands out in particular,
+as it does not obey this model. Our observations, therefore, reveal the
+unconventional nature of non-superconducting state of cerium superhydride
+CeH$_{10}$.",2307.11742v2
+2023-08-21,Proximity-induced sequence of field transitions in Kitaev candidate BaCo$_2$(AsO$_4$)$_2$,"We study field-induced phase transitions of the minimal exchange model
+proposed earlier for BaCo$_2$(AsO$_4$)$_2$, a candidate for Kitaev honeycomb
+model, using numerical minimization of classical spin clusters. We show that
+experimentally observed sequence of step-like transitions in magnetic field is
+realized in the phase diagram of the minimal model. Surprisingly, intermediate
+up-up-down plateau phase is stabilized only in the proximity of a
+double-zigzag$-$zigzag phase boundary. We systematically map out the region of
+stability of experimentally observed cascade of transitions and argue that
+BaCo$_2$(AsO$_4$)$_2$ exchange parameters are close to a region of strong phase
+competition, which can explain suppressed saturation field.",2308.10672v2
+2023-08-30,Impact of epitaxial strain relaxation on ferromagnetism in a freestanding La2/3Sr1/3MnO3 membrane,"Manganite perovskites host emerging physical properties of
+strongly-correlated electrons with charge, spin, and lattice degrees of
+freedom. Using epitaxial lift-off technique, we report enhancement of
+saturation magnetization and ferromagnetic transition temperature of the
+freestanding La2/3Sr1/3MnO3 membrane compared with the as-grown film on SrTiO3
+substrate involving lateral tensile strain. Structural analysis reveals
+shrinkage of unit-cell volume by tensile strain relaxation in the freestanding
+membrane, which causes enhancement of the ferromagnetic interaction. The impact
+of the microscopic lattice deformation on the ferromagnetism of La2/3Sr1/3MnO3
+indicates a high potential of this material for flexible electronics
+application with intriguing functionalities in strongly-correlated electron
+systems.",2308.16045v1
+2023-09-05,Post disruption reconnection event driven by a runaway current,"The role of a runaway current in a post disruption plasma is investigated
+through numerical simulations in an asymmetric magnetic reconnection event.
+While the runaways do not alter the linear growth of the island, they lead to a
+rotation of the island in the poloidal direction as found in [C. Liu et al.
+Physics of Plasmas 27, 092507 (2020)]. The role of a microlayer smaller than
+the resistive one is thoroughly investigated. While the resistive layer
+controls the transition of the island from the linear to the nonlinear stage,
+the microlayer width causes the runaways to become nonlinear as soon as the
+size of the island exceeds it. Moreover, this transition of the runways
+electrons to the nonlinear phase is accompanied by a drastic redistribution of
+runaways within the island with respect to the symmetric case. The influence of
+the electron skin depth on the linear evolution is also taken into account.
+Finally, nonlinear simulations show that the rotation frequency tends toward
+zero when the island saturates.",2309.02549v1
+2023-10-09,Estimation theory of photon-magnon coupling strength in a driven-dissipative double-cavity-magnon system,"Cavity-magnon systems are emerging as a fruitful architecture for the
+integration of quantum technologies and spintronic technologies, where magnons
+are coupled to microwave photons via the magnetic-dipole interaction.
+Controllable the photon-magnon (P-M) couplings provide a powerful means of
+accessing and manipulating quantum states in such hybrid systems. Thus
+determining the relevant P-M couplings is a fundamental task. Here we address
+the quantum estimation problem for the P-M coupling strength in a
+double-cavity-magnon system with drive and dissipation. The effects of various
+physical factors on the estimation precision are investigated and the
+underlying physical mechanisms are discussed in detail. Considering that in
+practical experiments it is almost infeasible to perform measurements on the
+global quantum state of this composite system, we identify the optimal
+subsystem for performing measurements and estimations. Further, we evaluate the
+performance of different Gaussian measurements, indicating that optimal
+Gaussian measurement almost saturates the ultimate theoretical bound on the
+estimation precision given by the quantum Fisher information.",2310.05412v1
+2023-10-19,Quantum Octets in Air Stable High Mobility Two-Dimensional PdSe2,"Two-dimensional (2D) materials have drawn immense interest in scientific and
+technological communities, owing to their extraordinary properties that are
+profoundly altered from their bulk counterparts and their enriched tunability
+by gating, proximity, strain, and external fields. For digital applications, an
+ideal 2D material would have high mobility, air stability, sizable band gap,
+and be compatible with large-scale synthesis. Here we demonstrate air-stable
+field-effect transistors using atomically thin few-layer PdSe2 sheets that are
+sandwiched between hexagonal BN (hBN), with record high saturation current
+>350{\mu}A/{\mu}m, and field effect mobilities 700 and 10,000 cm2/Vs at 300K
+and 2K, respectively. At low temperatures, magnetotransport studies reveal
+unique octets in quantum oscillations, arising from 2-fold spin and 4-fold
+valley degeneracies, which can be broken by in-plane and out-of-plane magnetic
+fields toward quantum Hall spin and orbital ferromagnetism.",2310.13154v1
+2024-01-03,Light thermal dark matter via type-I seesaw portal,"We propose a minimal scenario for light thermal dark matter (DM) in sub-GeV
+to GeV ballpark by incorporating a scalar singlet DM in a type-I seesaw
+scenario extended by an additional Higgs doublet $\phi_2$. The latter permits
+efficient annihilation of light scalar DM into leptonic final states including
+right-handed neutrinos (RHN). While DM annihilation into charged lepton final
+states is kept either suppressed or in a kinematically forbidden ballpark to
+avoid cosmic microwave background (CMB) bounds, the RHN, active neutrino final
+states remain safe from such bounds even if they are allowed kinematically. We
+discuss the interplay of forbidden and non-forbidden channels in generating
+light thermal DM relic while incorporating constraints from cosmology as well
+as laboratory experiments. The model can also explain the anomalous magnetic
+moment of muon, W-mass anomaly and saturate experimental bounds on charged
+lepton flavour violation and DM direct detection while offering tantalising
+detection prospects of the lightest RHN, the mass of which is kept in the same
+ballpark as DM.",2401.01639v1
+2024-01-05,Resonant Decay of Kinetic Alfvén Waves and Implication on Spectral Cascading,"A general equation describing the resonant nonlinear mode-coupling among
+kinetic Alfv\'en waves (KAWs) is derived using nonlinear gyrokinetic theory,
+which can be applied to study the potentially strong spectral energy transfer
+of KAWs. As a first application, the parametric decay of a pump KAW into two
+sideband KAWs are studied, with particular emphasis on the cascading in
+perpendicular wavenumber. It is found that, for the ""co-propagating"" cases with
+all three KAWs propagating in the same direction along the equilibrium magnetic
+field line, it exhibits a dual cascading character in the perpendicular
+wavenumber space; while for the ""counter-propagating"" cases with one sideband
+propagating in the opposite direction with respect to the pump wave, it
+instead, can exhibit both dual and inverse cascading behaviors. The
+implications on SAW instability nonlinear saturation and charged particle
+transport in fusion plasmas is also discussed.",2401.02711v1
+2024-01-20,A review on the Vortex and Coherent Structures in Dusty Plasma Medium,"Dusty plasma which is nothing but an admixture of electrons, ions and massive
+charged solid particles of sub-micron to micron sized in the background of
+neutrals. The dust grain medium exhibits fluid as well as solid-like
+characteristics depending on the background medium conditions. It supports
+various self-sustained non-linear dynamical structures as a result of the
+saturation of instabilities. The vortical or vortex structure in the dusty
+plasma medium is one of self-sustained dynamical structures that are formed
+either by internal instabilities or external perturbation. In this review
+report, the author discusses the theoretical, experimental, and computational
+research works on vortical and coherent structures in unmagnetized as well as
+in magnetized dusty plasma. The sources of vortex formation such as obstacle,
+ion drag shear, dust charge gradient, RT and K-H instabilities are pointed out
+in detail. The studies on the evolution of vortices by researchers are also
+discussed.",2401.11209v1
+2024-02-12,Experimental roadmap for optimal state transfer and entanglement generation in power-law systems,"Experimental systems with power-law interactions have recently garnered
+interest as promising platforms for quantum information processing. Such
+systems are capable of spreading entanglement superballistically and achieving
+an asymptotic speed-up over locally interacting systems. Recently, protocols
+developed by Eldredge et al. [Phys. Rev. Lett. 119, 170503 (2017)] and Tran et
+al. [Phys. Rev. X 11, 031016 (2021)] for the task of transferring a quantum
+state between distant particles quickly were shown to be optimal and saturate
+theoretical bounds. However, the implementation of these protocols in physical
+systems with long-range interactions remains to be fully realized. In this
+work, we provide an experimental roadmap towards realizing fast state-transfer
+protocols in three classes of atomic and molecular systems with dipolar
+interactions: polar molecules composed of alkali-metal dimers, neutral atoms in
+excited Rydberg states, and atoms with strong magnetic moments (e.g.
+dysprosium). As a guide to near-term experimental implementation, we
+numerically evaluate the tradeoffs between the two protocols for small system
+sizes and develop methods to address potential crosstalk errors that may arise
+during the execution of the protocols.",2402.07974v1
+2024-03-28,Infrared Vertical External Cavity Surface Emitting Laser Threshold Magnetometer,"Nitrogen-vacancy (NV) centers have considerable promise as high sensitivity
+magnetometers, however are commonly limited by inefficient collection and low
+contrasts. Laser threshold magnetometry (LTM) enables efficient collection and
+high contrasts, providing a path towards higher sensitivity magnetometry. We
+demonstrate an infrared LTM using an ensemble of NV centers in a single crystal
+diamond plate integrated into a vertical external cavity surface emitting
+laser. The laser was tuned to the spin dependent absorption line of the NV
+centers, allowing for optical readout by monitoring the laser output power. We
+demonstrate a magnetic sensitivity of 7.5~nT/$\sqrt{\textit{Hz}}$ in the
+frequency range between 10 and 50 Hz. Furthermore, the contrast and the
+projected PSNL sensitivity are shown to improve significantly by operating
+close to the lasing threshold, achieving 18.4\% and
+26.6~pT/$\sqrt{\textit{Hz}}$ near threshold. What's more, an unexpected
+saturable absorption phenomenon was observed near threshold, which enhanced the
+contrast and projected PSNL sensitivity.",2403.19751v1
+2024-04-02,Robustness of high-$β$ W7-X plasmas against ideal ballooning instability,"To examine the robustness of the designed 5% $\beta$-limit for
+high-performance operation in the W7-X stellarator, we undertake nonlinear
+magnetohydrodynamic (MHD) simulations of pressure-driven instabilities using
+the M3D-$C^1$ code. Consistent with linear analyses, ideal ballooning
+instabilities occur as $\beta$ exceeds 5% in the standard configuration.
+Nonetheless, the modes saturate nonlinearly at relatively low levels without
+triggering large-scale crashes, even though confinement degradation worsens as
+$\beta$ increases. In contrast, in an alternative configuration with nearly
+zero magnetic shear, ideal interchange modes induce a pressure crash at $\beta=
+1\%$. These results suggest that the standard W7-X configuration might have a
+soft $\beta$-limit that is fairly immune to major MHD events, and that
+interchange instabilities tend to be more detrimental than ideal ballooning in
+stellarators.",2404.01966v1
+2001-06-20,Saturation of electrical resistivity in metals at large temperatures,"We present a microscopic model for systems showing resistivity saturation. An
+essentially exact quantum Monte-Carlo calculation demonstrates that the model
+describes saturation. We give a simple explanation for saturation, using charge
+conservation and considering the limit where thermally excited phonons have
+destroyed the periodicity. Crucial model features are phonons coupling to the
+hopping matrix elements and a unit cell with several atoms. We demonstrate the
+difference to a model of alkali-doped C60 with coupling to the level positions,
+for which there is no saturation.",0106397v2
+2005-10-15,Observation of Interband Two-Photon Absorption Saturation in CdS Nanocrystals,"We report the observation of interband two-photon absorption (TPA) saturation
+in cadmium sulfide nanocrystals (CdS NCs) under intense femtosecond laser
+excitation with 1.6-eV photon energy. The observation has been compared to
+interband TPA saturation in bulk CdS under the same experimental conditions. By
+using both Z-scan technique and transient absorption measurement, the
+saturation intensity has been determined to be 190 GW/cm^2 for CdS NCs of 4-nm
+diameter, which shows two orders of magnitude greater than that for CdS bulk
+crystal. The results are in agreement with an inhomogeneously-broadened,
+saturated TPA model.",0510402v1
+2002-12-23,Strangeness Saturation: Energy- and System-Size Dependence,"Relativistic heavy-ion collisions lead to a final state which has a higher
+degree of strangeness saturation than those of elementary collisions. A
+systematic analysis of this phenomenon, based on the strangeness saturation
+factor, is made for C+C, Si+Si and Pb+Pb collisions at the CERN SPS collider
+and for Au+Au collisions at RHIC energies. Strangeness saturation is shown to
+increase with the number of participants within a colliding system, at both
+CERN SPS and RHIC energies. The saturation observed in central collisions of
+lighter nuclei deviates from that seen in peripheral collisions of heavier
+nuclei with an equivalent participant number, which could be due to the
+difference in nuclear density.",0212335v1
+2003-08-31,Contributions of gluon recombination to saturation phenomena,"Parton distributions in the small $x$ region are numerically predicted by
+using a modified DGLAP equation with the GRV-like input distributions. We find
+that gluon recombination at twist-4 level obviously suppresses the rapid growth
+of parton densities with $x$ decrease. We show that before the saturation scale
+$Q^2_s$ is reached, saturation and partial saturation appear in the small $x$
+behavior of parton distributions in nucleus and free proton, respectively. The
+antishadowing contributions to the saturation phenomena are also discussed.",0309003v1
+2003-12-18,Saturation at Hadron Colliders,"We extend the saturation models a la Golec-Biernat and Wusthoff to
+cross-sections of hard processes initiated by virtual-gluon probes separated by
+large rapidity intervals at hadron colliders. We derive their analytic
+expressions and apply them to physical examples, such as saturation effects for
+Mueller-Navelet forward jets. By comparison to gamma*-gamma* cross-sections we
+find a more abrupt transition to saturation. We propose to study observables
+with a potentially clear saturation signal and to use heavy vector and flavored
+mesons as alternative hard probes to forward jets.",0312261v2
+2004-06-09,Saturation in two-hard-scale processes at hadron colliders,"A study of saturation effects in two-hard-scale hadronic processes such as
+Mueller-Navelet jets is presented. The cross-sections are expressed in the
+dipole framework while saturation is implemented via an extention of the
+Golec-Biernat and Wusthoff model. The transition to saturation is found to be
+more abrupt than in gamma*-gamma* cross-sections. Observables with a
+potentially clear saturation signal are proposed.",0406111v1
+1992-10-12,Saturation in the Nuclear Matter Problem,"Once density-dependent meson masses are introduced into the nuclear many-body
+problem, conventional mechanisms for saturation no longer operate. We suggest
+that a loop correction, essentially the introduction of the axial vector
+coupling $g_A(\rho,k)$ as function of density $\rho$ and momentum $k$, can
+bring about saturation, and present schematic calculations to illustrate this.
+We find that a very small density-dependence in $g_A$ gives rise to a very
+large saturating effect on nuclear matter. In fact, this new saturation
+mechanism turns out to be more powerful than any of the conventional
+mechanisms.",9210010v1
+2012-06-18,Saturated fractions of two-factor designs,"In this paper we study saturated fractions of a two-factor design under the
+simple effect model. In particular, we define a criterion to check whether a
+given fraction is saturated or not, and we compute the number of saturated
+fractions. All proofs are constructive and can be used as actual methods to
+build saturated fractions. Moreover, we show how the theory of Markov bases for
+contingency tables can be applied to two-factor designs for moving between the
+designs with given margins.",1206.3911v2
+2013-01-16,Saturating Auto-Encoders,"We introduce a simple new regularizer for auto-encoders whose hidden-unit
+activation functions contain at least one zero-gradient (saturated) region.
+This regularizer explicitly encourages activations in the saturated region(s)
+of the corresponding activation function. We call these Saturating
+Auto-Encoders (SATAE). We show that the saturation regularizer explicitly
+limits the SATAE's ability to reconstruct inputs which are not near the data
+manifold. Furthermore, we show that a wide variety of features can be learned
+when different activation functions are used. Finally, connections are
+established with the Contractive and Sparse Auto-Encoders.",1301.3577v3
+2015-05-11,Saturation and Geometrical Scaling: from Deep Inelastic ep Scattering to Heavy Ion Collisions,"Saturation of gluon distribution is a consequence of the non-linear evolution
+equations of QCD. Saturation implies the existence of so called saturation
+momentum which is defined as a gluon density per unit rapidity per transverse
+area. At large energies for certain kinematical domains saturation momentum is
+the only scale for physical processes. As a consequence different observables
+exhibit geometrical scaling (GS). We discuss a number of examples of GS in
+different reactions.",1505.02458v1
+2016-02-07,Phonon lasing as a likely mechanism for density-dependent velocity saturation in GaN transistors,"We show that density-dependent velocity saturation in a GaN High Electron
+Mobility Transistor (HEMT) can be related to the stimulated emission of
+longitudinal optical (LO) phonons. As the drift velocity of electrons
+increases, the drift of the Fermi distribution in reciprocal space produces
+population inversion and gain for the LO phonons. Once this gain reaches a
+threshold value, the avalanche-like increase of LO emission causes a rapid loss
+of electron energy and momentum and leads to drift velocity saturation. Our
+simple model correctly predicts both the general trend of the saturation
+velocity decreasing with increasing electron density and the values of
+saturation velocity measured in our experiments.",1602.02417v1
+2016-07-04,Unconventional double-bended saturation of optical transmission in graphene due to many-particle interactions,"We present a joint theory-experiment study on the transmission/absorption
+saturation after ultrafast pulse excitation in graphene. We reveal an
+unconventional double-bended saturation behavior: Both bendings separately
+follow the standard saturation model exhibiting two saturation fluences,
+however, the corresponding fluences differ by three orders of magnitude and
+have different physical origin. Our results reveal that this new and unexpected
+behavior can be ascribed to an interplay between fluence- and time-dependent
+many-particle scattering processes and phase-space filling effects.",1607.00870v1
+2016-10-07,"Transitively-Saturated Property, Banach Recurrence and Lyapunov Regularity","The topological entropy of various gap-sets on periodic-like recurrence and
+Birkhoff regularity were considered in [69] but some Banach recurrence and
+Lyapunov regularity are not considered.
+  In this paper we introduce five new levels on Banach recurrence and show they
+all carry full topological entropy, and simultaneously combine with Lyapunov
+regularity to get some refined theory on mixed multifractal analysis of [8,29].
+  In this process, we strengthen Pfister and Sullivan's result of [58] from
+saturated property to transitively-saturated property (and from
+single-saturated property to transitively-convex-saturated property).",1610.02166v2
+2018-06-18,Detour-saturated graphs of small girths,"A detour of a graph G is a longest path in G. The detour order of G is the
+number of vertices in a detour of G. A graph is said to be detour-saturated if
+the addition of any edge increases strictly the detour order. L.W. Beineke,
+J.E. Dunbar and M. Frick asked the following three questions in 2005. (1) What
+is the smallest order of a detour-saturated graph of girth 4? (2) Let Pr be the
+graph obtained from the Petersen graph by splitting one of its vertices into
+three leaves. Is Pr the smallest triangle-free detour-saturated graph? (3) Does
+there exist a detour-saturated graph with finite girth bigger than 5? We answer
+these questions.",1806.06564v1
+2019-01-28,Induced Saturation of $P_{6}$,"A graph $G$ is called $H$-induced-saturated if $G$ does not contain an
+induced copy of $H$, but removing any edge from $G$ creates an induced copy of
+$H$ and adding any edge of $G^{c}$ to $G$ creates an induced copy of $H$.
+Martin and Smith showed that there does not exist a $P_{4}$-induced-saturated
+graph, where $P_{4}$ is the path on 4 vertices. Axenovich and Csik\'os studied
+related questions, and asked if there exists a $P_{n}$-induced-saturated graph
+for any $n\geq5$. Our aim in this short note is to show that there exists a
+$P_{6}$-induced-saturated graph.",1901.09801v1
+2023-11-28,Finite-Time Computation of Polyhedral Input-Saturated Output-Admissible Sets,"The paper introduces a novel algorithm for computing the output admissible
+set of linear discrete-time systems subject to input saturation. The proposed
+method takes advantage of the piecewise-affine dynamics to propagate the output
+constraints within the non-saturated and saturated regions. The constraints are
+then shared between regions to ensure a proper transition from one region to
+another. The resulting algorithm generates a set that is proven to be
+polyhedral, safe, positively invariant, and finitely determined. Moreover, the
+set is also proven to be strictly larger than the maximal output admissible set
+that would be obtained by treating input saturation as a constraint.",2311.16427v1
+2024-01-29,Bandwidth-induced saturation in multimode fiber-based absorbers,"Multimode fiber-based saturable absorbers enable mode-locking in lasers,
+generating ultrafast pulses and providing an exceptional platform for
+investigating nonlinear phenomena. Previous analyses in the continuous wave
+(CW) limit showed that saturable absorption can be obtained due to nonlinear
+interactions between transverse modes. We find experimentally that saturable
+absorption can be achieved thanks to the interplay of single-mode fiber
+nonlinearity and the wavelength-dependent linear transmission of the multimode
+fiber, even with negligible intermodal nonlinearities. We further show that
+even when intermodal nonlinearities are significant, the CW analysis may not be
+sufficient for long multimode fibers. Understanding the underlying mechanisms
+of multimode fiber-based saturable absorbers opens new possibilities for
+developing programmable devices for ultrafast control.",2401.16121v1
+2020-03-09,Localized magnetic field structures and their boundaries in the near-Sun solar wind from Parker Solar Probe measurements,"One of the discoveries made by Parker Solar Probe during first encounters
+with the Sun is the ubiquitous presence of relatively small-scale structures
+standing out as sudden deflections of the magnetic field. They were called
+switchbacks as some of them show up the full reversal of the radial component
+of the magnetic field and then return to regular conditions. Analyzing the
+magnetic field and plasma perturbations associated with switchbacks we identify
+three types of structures with slightly different characteristics: 1. Alfvenic
+structures, where the variations of the magnetic field components take place
+while the magnitude of the field remains constant; 2. Compressional, the field
+magnitude varies together with changes of the components; 3. Structures
+manifesting full reversal of the magnetic field (extremal class of Alfvenic
+structures). Processing of structures boundaries and plasma bulk velocity
+perturbations lead to the conclusion that they represent localized magnetic
+field tubes with enhanced parallel plasma velocity and ion beta moving together
+with respect to surrounding plasma. The magnetic field deflections before and
+after the switchbacks reveal the existence of total axial current. The electric
+currents are concentrated on the relatively narrow boundary layers on the
+surface of the tubes and determine the magnetic field perturbations inside the
+tube. These currents are closed on the structure surface, and typically have
+comparable azimuthal and the axial components. The surface of the structure may
+also accommodate an electromagnetic wave, that assists to particles in carrying
+currents. We suggest that the two types of structures we analyzed here may
+represent the local manifestations of the tube deformations corresponding to a
+saturated stage of the Firehose instability development.",2003.05409v1
+2002-09-04,Electrical resistivity at large temperatures: Saturation and lack thereof,"Many transition metal compounds show saturation of the resistivity at high
+temperatures, T, while the alkali-doped fullerenes and the high-Tc cuprates are
+usually considered to show no saturation. We present a model of transition
+metal compounds, showing saturation, and a model of alkali-doped fullerenes,
+showing no saturation. To analyze the results we use the f-sum rule, which
+leads to an approximate upper limit for the resistivity at large T. For some
+systems and at low T, the resistivity increases so rapidly that this upper
+limit is approached for experimental T. The resistivity then saturates. For a
+model of transition metal compounds with weakly interacting electrons, the
+upper limit corresponds to a mean free path consistent with the Ioffe-Regel
+condition. For a model of the high Tc cuprates with strongly interacting
+electrons, however, the upper limit is much larger than the Ioffe-Regel
+condition suggests. Since this limit is not exceeded by experimental data, the
+data are consistent with saturation also for the cuprates. After ""saturation""
+the resistivity usually grows slowly. For the alkali-doped fullerenes,
+""saturation"" can be considered to have happened already for T=0, due to
+orientational disorder. For these systems, however, the resistivity grows so
+rapidly after ""saturation"" that this concept is meaningless. This is due to the
+small band width and to the coupling to the level energies of the important
+phonons.",0209099v1
+2010-06-22,Sustainable Throughput of Wireless LANs with Multi-Packet Reception Capability under Bounded Delay-Moment Requirements,"With the rapid proliferation of broadband wireless services, it is of
+paramount importance to understand how fast data can be sent through a wireless
+local area network (WLAN). Thanks to a large body of research following the
+seminal work of Bianchi, WLAN throughput under saturated traffic condition has
+been well understood. By contrast, prior investigations on throughput
+performance under unsaturated traffic condition was largely based on
+phenomenological observations, which lead to a common misconception that WLAN
+can support a traffic load as high as saturation throughput, if not higher,
+under non-saturation condition. In this paper, we show through rigorous
+analysis that this misconception may result in unacceptable quality of service:
+mean packet delay and delay jitter may approach infinity even when the traffic
+load is far below the saturation throughput. Hence, saturation throughput is
+not a sound measure of WLAN capacity under non-saturation condition. To bridge
+the gap, we define safe-bounded-mean-delay (SBMD) throughput and
+safe-bounded-delay-jitter (SBDJ) throughput that reflect the actual network
+capacity users can enjoy when they require finite mean delay and delay jitter,
+respectively.
+  Our earlier work proved that in a WLAN with multi-packet reception (MPR)
+capability, saturation throughput scales super-linearly with the MPR capability
+of the network. This paper extends the investigation to the non-saturation case
+and shows that super-linear scaling also holds for SBMD and SBDJ throughputs.
+Our results here complete the demonstration of MPR as a powerful
+capacity-enhancement technique for WLAN under both saturation and
+non-saturation conditions.",1006.4228v1
+2022-10-10,A hyperbolic-elliptic PDE model and conservative numerical method for gravity-dominated variably-saturated groundwater flow,"Richards equation is often used to represent two-phase fluid flow in an
+unsaturated porous medium when one phase is much heavier and more viscous than
+the other. However, it cannot describe the fully saturated flow due to
+degeneracy in the capillary pressure term. Mathematically, gravity-driven
+variably saturated flows are interesting because their governing partial
+differential equation switches from hyperbolic in the unsaturated region to
+elliptic in the saturated region. Moreover, the presence of wetting fronts
+introduces strong spatial gradients often leading to numerical instability. In
+this work, we develop a robust, multidimensional mathematical and computational
+model for such variably saturated flow in the limit of negligible capillary
+forces. The elliptic problem for saturated regions is built-in efficiently into
+our framework for a reduced system corresponding to the saturated cells, with
+the boundary condition of the fixed head at the unsaturated cells. In summary,
+this coupled hyperbolic-elliptic PDE framework provides an efficient,
+physics-based extension of the hyperbolic Richards equation to simulate fully
+saturated regions. Finally, we provide a suite of easy-to-implement yet
+challenging benchmark test problems involving saturated flows in one and two
+dimensions. These simple problems, accompanied by their corresponding
+analytical solutions, can prove to be pivotal for the code verification, model
+validation (V&V) and performance comparison of such simulators. Our numerical
+solutions show an excellent comparison with the analytical results for the
+proposed problems. The last test problem on two-dimensional infiltration in a
+stratified, heterogeneous soil shows the formation and evolution of multiple
+disconnected saturated regions.",2210.04724v1
+1998-10-21,Nonlinear Alpha Effect in Dynamo Theory,"We extend the standard two-scale theory of the turbulent dynamo coefficient
+$\alpha$ to include the nonlinear back reaction of the mean field $\bar B$ on
+the turbulence. We calculate the turbulent emf as a power series in $\bar B$,
+assuming that the base state of the turbulence ($\bar B=0$) is isotropic, and,
+for simplicity, that the magnetic diffusivity equals the kinematic viscosity.
+The power series converges for all $\bar B$, and for the special case that the
+spectrum of the turbulence is sharply peaked in $k$, our result is proportional
+to a tabulated function of the magnetic Reynolds number $R_M$ and the ratio
+$\beta$ of $\bar B$ (in velocity units) to the rms turbulent velocity $v_0$.
+For $\beta\to 0$ (linear regime) we recover the results of Steenbeck et al.
+(1966) as modified by Pouquet et al. (1976). For $R_M\gg 1$, the usual
+astrophysical case, $\alpha$ starts to decrease at $\beta \sim 1$, dropping
+like $\beta^{-2}$ as $\beta \to \infty$. Hence for large $R_M$, $\alpha$
+saturates at $\bar B\sim v_0$, as estimated by Kraichnan (1979), rather than at
+$\bar B\sim R^{-1/2}_Mv_0$, as inferred by Cattaneo and Hughes (1996) from
+their numerical simulations at $R_M$=100. We plan to carry out simulations with
+various values of $R_M$ to investigate the discrepency.",9810345v1
+2001-01-26,Global accretion disk simulations of magneto-rotational instability,"We perform global three-dimensional simulations of accretion disks
+integrating the compressible, non-viscous, but diffusive MHD equations. The
+disk is supposed to be isothermal. We make use of the ZEUS-3D code integrating
+the MHD equations and added magnetic diffusivity. We measure the efficiency of
+the angular-momentum transport. Various model simulations delivered transport
+parameters of alpha_SS=0.01 to 0.05 which are consistent with several local
+numerical investigations. Two of the models reach a highly turbulent state at
+which alpha_SS is of the order of 0.1. After a certain stage of saturating of
+the turbulence, Reynolds stress is found to be negative (inward transport) in
+many of the models, whereas Maxwell stresses dominate and deliver a positive
+(outward) total transport. Several of the models yield strongly fluctuating
+Reynolds stresses, while Maxwell stresses are smooth and always transport
+outwards.
+  Dynamo action is found in the accretion disk simulations. A positive
+dynamo-alpha is indicated in the northern hemisphere of the most prominent run,
+coming along with negative kinetic and current helicities (all having the
+opposite sign on the southern side). The dipolar structure of the magnetic
+field is maintained throughout the simulations, although indication for a decay
+of antisymmetry is found. The simulations covered relatively thick disks, and
+results of thin-disk dynamo models showing quadrupolar fields may not be
+compatible with the results presented here.",0101470v1
+2001-10-01,A variable efficiency for thin disk black hole accretion,"We explore the presence of torques at the inner edges of geometrically-thin
+black hole accretion disks using 3-dimensional magnetohydrodynamic (MHD)
+simulations in a pseudo-Newtonian potential. By varying the saturation level of
+the magnetorotational instability that leads to angular momentum transport, we
+show that the dynamics of gas inside the radius of marginal stability varies
+depending upon the magnetic field strength just outside that radius. Weak
+fields are unable to causally connect material within the plunging region to
+the rest of the disk, and zero torque is an approximately correct boundary
+condition at the radius of marginal stability. Stronger fields, which we obtain
+artificially but which may occur physically within more complete disk models,
+are able to couple at least some parts of the plunging region to the rest of
+the disk. In this case, angular momentum (and implicitly energy) is extracted
+from the material in the plunging region. Furthermore, the magnetic coupling to
+the plunging region can be highly time dependent with large fluctuations in the
+torque at the radius of marginal stability. This implies varying accretion
+efficiencies, both across systems and within a given system at different times.
+The results suggest a possible link between changes in X-ray and outflow
+activity, with both being driven by transitions between weak and strong field
+states.",0110028v1
+2002-03-02,The Magnetohydrodynamics of Convection-Dominated Accretion Flows,"Radiatively inefficient accretion flows onto black holes are unstable due to
+both an outwardly decreasing entropy (`convection') and an outwardly decreasing
+rotation rate (the `magnetorotational instability'; MRI). Using a linear
+magnetohydrodynamic stability analysis, we show that long-wavelength modes are
+primarily destabilized by the entropy gradient and that such `convective' modes
+transport angular momentum inwards. Moreover, the stability criteria for the
+convective modes are the standard Hoiland criteria of hydrodynamics. By
+contrast, shorter wavelength modes are primarily destabilized by magnetic
+tension and differential rotation. These `MRI' modes transport angular momentum
+outwards. The convection-dominated accretion flow (CDAF) model, which has been
+proposed for radiatively inefficient accretion onto a black hole, posits that
+inward angular momentum transport and outward energy transport by
+long-wavelength convective fluctuations are crucial for determining the
+structure of the accretion flow. Our analysis suggests that the CDAF model is
+applicable to a magnetohydrodynamic accretion flow provided the magnetic field
+saturates at a sufficiently sub-equipartition value (plasma beta >> 1), so that
+long-wavelength convective fluctuations can fit inside the accretion disk.
+Numerical magnetohydrodynamic simulations are required to determine whether
+such a sub-equipartition field is in fact obtained.",0203026v2
+2002-07-06,The nonlinear small-scale dynamo and isotropic MHD turbulence,"This is a brief review of the main results of our recent studies of the
+nonlinear evolution of the small-scale MHD dynamo in the high-Prandtl-number
+regime and of the structure of the resulting saturated state of the isotropic
+homogeneous MHD turbulence. It is emphasized that the MHD regime without a
+uniform mean field (as is the case in our studies) is fundamentally different
+from the one in which such a field is externally imposed. The ability of the
+turbulence to bend and fold the magnetic-field lines leads to the emergence of
+a distinctive small-scale structure. The fields are organized in folds of
+characteristic length comparable to the size of the largest turbulent eddies
+with spatial-direction reversals at the resistive scale. These folds are very
+hard to destroy. In the nonlinear regime, the folding structure coexists with
+Alfven waves propagating along the folds. The turbulent energy injected by the
+forcing is dissipated in part resistively via the small-scale magnetic fields,
+and in part viscously via the Alfven waves.",0207151v1
+2002-08-30,Compton Heated Outflow from CDAFs,"Convection-dominated accretion flows (CDAF) are expected to have a shallower
+density profile and a higher radiation efficiency as compared to
+advection-dominated accretion flows (ADAF). Both solutions have been developed
+to account for the observed properties of the low luminosity, high temperature
+X-ray sources believed to involve accretion onto massive black holes.
+Self-similar CDAFs also have steeper poloidal density gradients and
+temperatures close to the virial temperature. All these characteristics make
+CDAFs more capable of producing polar outflows driven by Compton heating as
+compared to other classical accretion disks. We investigate the conditions for
+producing such outflows in CDAFs and look for the mass accretion rate, or,
+equally, the luminosity of CDAFs for which such outflows will exist. When the
+electron temperature saturates around 10^11 K at the inner region, polar
+outflows are probable for 8x10^-7 <~ L/L_E <~ 4x10^-5, where L_E is the
+Eddington luminosity. Outflows are well collimated with small opening angles.
+The luminosity range for which outflow solutions exist is narrower for lower
+electron temperature flows and disappears completely for electron temperature
+<~ 6x10^9 K. When the magnetic field is present, we find that outflows are
+possible if the magnetic field is less than from 10% to 1% of the equipartition
+field. We also find that outflows are more likely to be produced when the
+viscosity parameter alpha is small. The tendency for jet-like collimated
+outflows for these solutions is presumably astrophysically relevant given the
+high frequency of jets from AGNs.",0208555v2
+2002-10-24,Local Magnetohydrodynamical Models of Layered Accretion Disks,"Using numerical MHD simulations, we have studied the evolution of the
+magnetorotational instability in stratified accretion disks in which the
+ionization fraction (and therefore resistivity) varies substantially with
+height. This model is appropriate to dense, cold disks around protostars or
+dwarf nova systems which are ionized by external irradiation of cosmic rays or
+high-energy photons. We find the growth and saturation of the MRI occurs only
+in the upper layers of the disk where the magnetic Reynolds number exceeds a
+critical value; in the midplane the disk remains queiscent. The vertical
+Poynting flux into the ""dead"", central zone is small, however velocity
+fluctuations in the dead zone driven by the turbulence in the active layers
+generate a significant Reynolds stress in the midplane. When normalized by the
+thermal pressure, the Reynolds stress in the midplane never drops below about
+10% of the value of the Maxwell stress in the active layers, even though the
+Maxwell stress in the dead zone may be orders of magnitude smaller than this.
+Significant mass mixing occurs between the dead zone and active layers.
+Fluctuations in the magnetic energy in the active layers can drive vertical
+oscillations of the disk in models where the ratio of the column density in the
+dead zone to that in the active layers is <10. These results have important
+implications for the global evolution of a layered disk, in particular there
+may be residual mass inflow in the dead layer. We discuss the effects that dust
+in the disk may have on our results.",0210541v1
+2002-11-20,Magnetic Field in Supernovae,"A relatively modest value of the initial rotation of the iron core, a period
+of ~ 6-31 s, will give a very rapidly rotating protoneutron star and hence
+strong differential rotation with respect to the infalling matter. Under these
+conditions, a seed field is expected to be amplified by the MRI and to grow
+exponentially. Exponential growth of the field on the time scale Omega^{-1} by
+the magnetorotational instability (MRI) will dominate the linear growth process
+of field line ""wrapping"" with the same characteristic time. The shear is
+strongest at the boundary of the newly formed protoneutron star. Modest initial
+rotation velocities of the iron core result in sub-Keplerian rotation and a
+sub-equipartition magnetic field that nevertheless produce substantial MHD
+luminosity and hoop stresses: saturation fields of order 10^{15} - 10^{16} G
+develop ~ 300 msec after bounce with an associated MHD luminosity of ~ 10^{49}
+- 10^{53} erg s^{-1}. Bi-polar flows driven by this MHD power can affect or
+even cause the explosions associated with core-collapse supernovae. If the
+initial rotation is too slow, then there will not be enough rotational energy
+to power the supernova despite the high luminosities. The MRI should be active
+and may qualitatively alter the flow if a black hole forms directly or after a
+fall-back delay.",0211458v1
+2003-05-26,Transition from collisionless to collisional MRI,"Recent calculations by Quataert et al. (2002) found that the growth rates of
+the magnetorotational instability (MRI) in a collisionless plasma can differ
+significantly from those calculated using MHD. This can be important in hot
+accretion flows around compact objects. In this paper we study the transition
+from the collisionless kinetic regime to the collisional MHD regime, mapping
+out the dependence of the MRI growth rate on collisionality. A kinetic closure
+scheme for a magnetized plasma is used that includes the effect of collisions
+via a BGK operator. The transition to MHD occurs as the mean free path becomes
+short compared to the parallel wavelength $2\pi/k_{\Par}$. In the weak magnetic
+field regime where the Alfv\'en and MRI frequencies $\omega$ are small compared
+to the sound wave frequency $k_{\Par} c_0$, the dynamics are still effectively
+collisionless even if $\omega \ll \nu$, so long as the collision frequency $\nu
+\ll k_{\Par} c_{0}$; for an accretion flow this requires $\nu \lsim \Omega
+\sqrt{\beta}$. The low collisionality regime not only modifies the MRI growth
+rate, but also introduces collisionless Landau or Barnes damping of long
+wavelength modes, which may be important for the nonlinear saturation of the
+MRI.",0305486v2
+2005-07-25,Steady-State Electrostatic Layers from Weibel Instability in Relativistic Collisionless Shocks,"It is generally accepted that magnetic fields generated in the nonlinear
+development of the transverse Weibel instability provide effective
+collisionality in unmagnetized collisionless shocks. Recently, extensive two
+and three dimensional simulations improved our understanding of the growth and
+saturation of the instability in colliding plasma shells. However, the
+steady-state structure of the shock wave transition layers remains poorly
+understood. We use basic physical considerations and order-of-magnitude
+arguments to study the steady state structure in relativistic unmagnetized
+collisionless shocks in pair plasmas. The shock contains an electrostatic layer
+resulting from the formation of stationary, magnetically-focused current
+filaments. The filaments form where the cold upstream plasma and the
+counterstreaming thermal plasma interpenetrate. The filaments are not entirely
+neutral and strong electrostatic fields are present. Most of the downstream
+particles cannot cross this layer into the upstream because they are trapped by
+the electrostatic field. We identify the critical location in the shock
+transition layer where the electromagnetic field ceases to be static. At this
+location, the degree of charge separation in the filaments reaches a maximum
+value, the current inside the filaments comes close to the Alfv\'en limit, and
+the phase space distribution function starts to isotropize. We argue that the
+radius of the current filaments upstream of the critical location is about
+twice the upstream plasma skin depth. Finally, we show that some downstream
+particles cross the electrostatic layer and run ahead of the shock into the
+preshock medium without causing instability. These particles may play an
+important role in particle acceleration.",0507553v1
+2006-03-28,Quark deconfinement in neutron star cores: The effects of spin-down,"We study the role of spin-down in driving quark deconfinement in the high
+density core of isolated neutron stars. Assuming spin-down to be solely due to
+magnetic braking, we obtain typical timescales to quark deconfinement for
+neutron stars that are born with Keplerian frequencies. Employing different
+equations of state (EOS), we determine the minimum and maximum neutron star
+masses that will allow for deconfinement via spin-down only. We find that the
+time to reach deconfinement is strongly dependent on the magnetic field and
+that this time is least for EOS that support the largest minimum mass at zero
+spin, unless rotational effects on stellar structure are large. For a fiducial
+critical density of $5\rho_0$ for the transition to the quark phase
+($\rho_0=2.5\times10^{14}$g/cm$^3$ is the saturation density of nuclear
+matter), we find that neutron stars lighter than $1.5M_{\odot}$ cannot reach a
+deconfined phase. Depending on the EOS, neutron stars of more than
+$1.5M_{\odot}$ can enter a quark phase only if they are spinning faster than
+about 3 milliseconds as observed now, whereas larger spin periods imply that
+they are either already quark stars or will never become one.",0603743v1
+1998-01-22,Density-matrix renormalization study of the Hubbard model on a Bethe lattice,"The half-filled Hubbard model on the Bethe lattice with coordination number
+$z=3$ is studied using the density-matrix renormalization group (DMRG) method.
+Ground-state properties such as the energy $E$, average local magnetization
+$<\hat S_z>$, its fluctuations $<\hat S_z^2 > - < \hat S_z>^2$ and various spin
+correlation functions $<\hat S_z(i) \hat S_z(j) > - < S_z(i)> < S_z(j)>$ are
+determined as a function of the Coulomb interaction strength $U/t$. The
+calculated local magnetic moments $<\hat S_z(i)>$ increase monotonically with
+increasing Coulomb repulsion $U/t$ forming an antiferromagnetic
+spin-density-wave state which matches the two sublattices of the bipartite
+Bethe lattice. At large $U/t$, $<\hat S_z(i)>$ is strongly reduced with respect
+to the saturation value 1/2 due to exchange fluctuations between nearest
+neighbors (NN) spins ($|< S_z(i)>|\simeq 0.35$ for $U/t\to +\infty$).
+$<S_z(i)^2> - < S_z(i)>^2$ shows a maximum for $U/t=2.4$--2.9 which results
+from the interplay between the usual increase of $<S_z(i)^2>$ with increasing
+$U/t$ and the formation of important permanent moments $<S_z(i)>$ at large
+$U/t$. NN sites show antiferromagnetic spin correlations which increase with
+increasing Coulomb repulsion. In contrast next NN sites are very weakly
+correlated over the whole range of $U/t$. The accuracy of the DMRG results is
+discussed by comparison with tight-binding exact results, independent DMRG
+calculations for the Heisenberg model and simple first-order perturbation
+estimates.",9801228v2
+1999-02-17,Quantum Monte Carlo Study of Weakly Coupled Spin Ladders,"We report a quantum Monte Carlo study of the thermodynamic properties of
+arrays of spin ladders with various widths ($n$), coupled via a weak
+inter-ladder exchange coupling $\alpha J$, where $J$ is the intra-ladder
+coupling both along and between the chains. This coupled ladder system serves
+as a simplified model for the magnetism of presumed ordered spin and charge
+stripes in the two-dimensional CuO$_2$ planes of hole-doped copper oxides. Our
+results for $n=3$ with weak inter-ladder coupling $\alpha=0.05$, estimated from
+the $t-t'-t''-J$ model, show good agreement with the ordering temperature of
+the recently observed spin density wave condensation in La$_2$CuO$_{4+y}$. We
+show that there exists a quantum critical point at $\alpha_c \simeq 0.07$ for
+$n=4$, and determine the phase diagram. Our data at this quantum critical point
+agree quantitatively with the universal scaling predicted by the quantum
+nonlinear $\sigma$ model. We also report results on random mixtures of $n=2$
+and $n=3$ ladders, which correspond to the doping region near but above 1/8.
+Our study on the magnetic static structure factor reveals a saturation of the
+incommensurability of the spin correlations around 1/8, while the
+incommensurability of the charge stripes grows linearly with hole
+concentration. The implications of this result for the interpretation of
+neutron scattering experiments on the dynamic spin fluctuations in
+La$_{2-x}$Sr$_x$CuO$_4$ are discussed.",9902248v1
+2000-08-24,Precursory Metal-Insulator transition in a small cluster of the `t-J' model: Exact analytic results,"We study the effect of hole hopping in a doped antiferromagnet described by
+the `t-J' model, using exact analytic solutions for small clusters. In spite of
+the small size, they reveal interesting details about the magnetic order, which
+are not apparent in Mean Field treatments or in numerical calculations. The
+4-site cluster with one hole yields the most interesting physics, displaying
+different behaviors for the ground state: i) an antiferromagnetic phase for
+t<<J, where the hole seems to be localized, not affecting the order of the
+Heisenberg spins; ii)another regime for t~J that presents mixed ferro and
+antiferro correlations and coexistence of metallic and insulating behaviors,
+with the presence of charge and spin density waves, in what may be the analog
+of the spiral phase obtained in Mean Field solutions; and finally iii)for t>>J,
+we obtain strong ferromagnetic correlations (maximum spin) and no density
+waves, with quantum fluctuations precluding the saturation of the magnetic
+moment. This behavior shows traces of a metal-insulator transition as the hole
+kinetic energy competes with the antiferromagnetic interactions.",0008373v1
+2001-11-06,Spin-dependent electrical transport in ion-beam sputter deposited Fe-Cr multilayers,"The temperature dependence of the electrical resistivity and
+magnetoresistance of Xe-ion beam sputtered Fe-Cr multilayers has been
+investigated. The electrical resistivity between 5 and 300 K in the fully
+ferromagnetic state, obtained by applying a field beyond the saturation field
+(H_sat) necessary for the antiferromagnetic(AF)-ferromagnetic(FM) field-induced
+transition, shows evidence of spin-disorder resistivity as in crystalline Fe
+and an s-d scattering contribution (as in 3d metals and alloys). The sublattice
+magnetization m(T) in these multilayers has been calculated in terms of the
+planar and interlayer exchange energies. The additional spin-dependent
+scattering \Delta \rho (T) = \rho(T,H=0)_AF - \rho(T,H=H_sat)_FM in the AF
+state over a wide range of temperature is found to be proportional to the
+sublattice magnetization, both \Delta \rho(T) and m(T) reducing along with the
+antiferromagnetic fraction. At intermediate fields, the spin-dependent part of
+the electrical resistivity (\rho_s (T)) fits well to the power law \rho_s (T) =
+b - cT^\alpha where c is a constant and b and \alpha are functions of H. At low
+fields \alpha \approx 2 and the intercept b decreases with H much the same way
+as the decrease of \Delta \rho (T) with T. A phase diagram (T vs. H_sat) is
+obtained for the field- induced AF to FM transition. Comparisons are made
+between the present investigation and similar studies using dc magnetron
+sputtered and molecular beam epitaxy (MBE) grown Fe-Cr multilayers.",0111084v1
+2001-11-20,The longitudinal dynamic correlation and dynamic susceptibility of the isotropic XY-model on the 1d alternating superlattice,"The dynamic susceptibility $\chi_{Q}^{zz}(\omega)$ of the isotropic XY-model
+(s=1/2) on the alternating superlattice (closed chain) in a transverse field
+$h$ is obtained exactly at arbitrary temperatures. It is determined from the
+results obtained for the dynamic correlations $<S_{jn}^{z}(t)S_{lm}^{z}(0)>$,
+which have been calculated by introducing the generalized Jordan-Wigner
+transformation, by using Wick's theorem and by reducing the problem to a
+diagonalization of a finite matrix. The static properties are also reobtained
+within this new formalism and all exact results are determined for arbitrary
+temperatures. Explicit results are obtained numerically in the limit T=0, where
+the critical behaviour occurs. A detailed analysis is presented for the
+behaviour of the static susceptibility $\chi_{Q}^{zz}(0)$, as a function of the
+transverse field h, and for the frequency dependency of the dynamic
+susceptibility $\chi_{Q}^{zz}(\omega)$. It is also shown, in this temperature
+limit, that within the magnetization plateaus which correspond to the different
+phases, even when the induced magnetization is not saturated, the effective
+dynamic correlation, $<\sum\limits_{n;m\in
+cell:\text{}j;l}S_{jn}^{z}(t)S_{lm}^{z}(0)>$, is time independent, which
+constitutes an unexpected result.",0111372v1
+2005-08-31,Spinel ferrites: old materials bring new opportunities for spintronics,"Over the past few years, intensive studies of ultrathin epitaxial films of
+perovskite oxides have often revealed exciting properties like giant
+magnetoresistive tunnelling and electric field effects. Spinel oxides appear as
+even more versatile due to their more complex structure and the resulting many
+degrees of freedom. Here we show that the epitaxial growth of nanometric
+NiFe2O4 films onto perovskite substrates allows the stabilization of novel
+ferrite phases with properties dramatically differing from bulk ones. Indeed,
+NiFe2O4 films few nanometres thick have a saturation magnetization at least
+twice that of the bulk compound and their resistivity can be tuned by orders of
+magnitude, depending on the growth conditions. By integrating such thin NiFe2O4
+layers into spin-dependent tunnelling heterostructures, we demonstrate that
+this versatile material can be useful for spintronics, either as a conductive
+electrode in magnetic tunnel junctions or as a spin-filtering insulating
+barrier in the little explored type of tunnel junction called spin-filter. Our
+findings are thus opening the way for the realisation of monolithic spintronics
+architectures integrating several layers of a single material, where the layers
+are functionalised in a controlled manner.",0508764v1
+2005-09-20,Formation of Mn2+ in La2/3Ca1/3MnO3 Thin Films due to Air Exposure,"We report on the chemical stability of La2/3Ca1/3MnO3 thin films. X-ray
+absorption spectroscopy at the Mn L-edge and O K-edge makes evident deviations
+from the nominally expected (2/3-1/3) Mn3+/Mn4+ ratio after the growth of thin
+films on LaAlO3 substrates. As-grown thin films, exhibiting Curie temperature,
+TC, well below that of the LCMO bulk material, develop an unexpected Mn2+
+contribution after a few days of air exposure which increases with time.
+Moreover, a reduction of the saturation magnetization, MS, is also detected.
+The similarity of the results obtained by electron yield and fluorescence yield
+demonstrates that the location of the Mn valence anomalies are not confined to
+a narrow surface region of the film but can extend throughout the film
+thickness in case of granular films. High temperature annealing not only
+improves the magnetic and transport properties of such as-grown films but also
+recovers the expected 2/3-1/3 Mn3+/Mn4+ ratio, which thereafter is stable to
+air exposure. Similar results on La2/3Ca1/3MnO3 films grown on SrTiO3 and
+NdGaO3 substrates demonstrate that there is no direct relation between the
+observed Mn valence instability and the strain state of the films due to their
+lattice mismatch with the substrate. A mechanism for the formation of Mn2+ ions
+formation is discussed.",0509513v1
+2006-09-29,Vortex configurations and critical parameters in superconducting thin films containing antidot arrays: Nonlinear Ginzburg-Landau theory,"Using the non-linear Ginzburg-Landau (GL) theory, we obtain the possible
+vortex configurations in superconducting thin films containing a square lattice
+of antidots. The equilibrium structural phase diagram is constructed which
+gives the different ground-state vortex configurations as function of the size
+and periodicity of the antidots for a given effective GL parameter
+$\kappa^{*}$. Giant-vortex states, combination of giant- and multi-vortex
+states, as well as symmetry imposed vortex-antivortex states are found to be
+the ground state for particular geometrical parameters of the sample. The
+antidot occupation number $n_o$ is calculated as a function of related
+parameters and comparison with existing expressions for the saturation number
+$n_s$ and with experimental results is given. For a small radius of antidots a
+triangular vortex lattice is obtained, where some of the vortices are pinned by
+the antidots and some of them are located between them. Transition between the
+square pinned and triangular vortex lattices is given for different values of
+the applied field. The enhanced critical current at integer and rational
+matching fields is found, where the level of enhancement at given magnetic
+field directly depends on the vortex-occupation number of the antidots. For
+certain parameters of the antidot lattice and/or temperature the critical
+current is found to be larger for higher magnetic fields.
+Superconducting/normal $H-T$ phase boundary exhibits different regimes as
+antidots are made larger, and we transit from a plain superconducting film to a
+thin-wire superconducting network. Presented results are in good agreement with
+available experiments and suggest possible new experiments.",0609772v1
+2006-10-24,"Synthesis, Structure, and Ferromagnetism of a New Oxygen Defect Pyrochlore System Lu2V2O_{7-x} (x = 0.40-0.65)","A new fcc oxygen defect pyrochlore structure system Lu2V2O_{7-x} with x =
+0.40 to 0.65 was synthesized from the known fcc ferromagnetic semiconductor
+pyrochlore compound Lu2V2O7 which can be written as Lu2V2O6O' with two
+inequivalent oxygen sites O and O'. Rietveld x-ray diffraction refinements
+showed significant Lu-V antisite disorder for x >= 0.5. The lattice parameter
+versus x (including x = 0) shows a distinct maximum at x ~ 0.4. We propose that
+these observations can be explained if the oxygen defects are on the O'
+sublattice of the structure. The magnetic susceptibility versus temperature
+exhibits Curie-Weiss behavior above 150 K for all x, with a Curie constant C
+that increases with x as expected in an ionic model. However, the magnetization
+measurements also show that the (ferromagnetic) Weiss temperature theta and the
+ferromagnetic ordering temperature T_C both strongly decrease with increasing x
+instead of increasing as expected from C(x). The T_C decreases from 73 K for x
+= 0 to 21 K for x = 0.65. Furthermore, the saturation moment at a field of 5.5
+T at 5 K is nearly independent of x, with the value expected for a fixed spin
+1/2 per V. The latter three observations suggest that Lu2V2O_{7-x} may contain
+localized spin 1/2 vanadium moments in a metallic background that is induced by
+oxygen defect doping, instead of being a semiconductor as suggested by the C(x)
+dependence.",0610680v1
+1994-09-20,Supersymmetric Dyonic Black Holes in Kaluza-Klein Theory,"We study supersymmetric, four-dimensional (4-d), Abelian charged black holes
+(BH's) arising in (4+n)-d (1 \le n \le 7) Kaluza-Klein (KK) theories. Such
+solutions, which satisfy supersymmetric Killing spinor equations (formally
+satisfied for any n) and saturate the corresponding Bogomol'nyi bounds, can be
+obtained if and only if the isometry group of the internal space is broken down
+to the U(1)_E \times U(1)_M gauge group; they correspond to dyonic BH's with
+electric Q and magnetic P charges associated with {\it different} U(1) factors.
+The internal metric of such configurations is diagonal with (n-2) internal
+radii constant, while the remaining two radii (associated with the respective
+electric and magnetic U(1) gauge fields) and the 4-d part of the metric turn
+out to be independent of n, i.e., solutions are effectively those of
+supersymmetric 4-d BH's of 6-d KK theory. For Q \ne 0 and P \ne 0, 4-d
+space-time has a null singularity, finite temperature (T_H \propto 1 /
+\sqrt{|QP|}) and zero entropy. Special cases with either Q=0 or P=0 correspond
+to the supersymmetric 4-d BH's of 5-d KK theory, first derived by Gibbons and
+Perry, which have a naked singularity and infinite temperature.",9409119v1
+2002-01-02,(3+0)D electromagnetic solitons and de Broglie's ''double solution'',"The well known light filaments are obtained in various media whose index of
+refraction increases before a saturation with the electric field; adding a
+small perturbation which increases the index with the magnetic field, and
+neglecting the absorption, a filament curves and closes into a torus. This
+transformation of a (2+1)D soliton into a (3+0)D soliton shows the existence of
+those solitons, while a complete study, with a larger magnetic effect, would
+require numerical computations, the starting point being, possibly, the
+perturbed, curved filament.
+  The flux of energy in the regular filaments is nearly a ''critical flux'',
+depending slightly on the external fields, so that the energy of the (3+0)D
+soliton is quantified, but may be slightly changed by external interactions.
+  The nearly linear part of the soliton, an evanescent wave, is partly
+transmitted by Young holes, making transmitted and reflected interference
+patterns, thus index variations which guide the remainder of the soliton, just
+as de Broglie's pilot waves.
+  The creation of electron positron pairs in the vacuum by purely
+electromagnetic fields shows a nonlinearity of vacuum at high energies;
+supposing this nonlinearity convenient, elementary particles may be (3+0)D
+solitons or light bullets, so that it may be a connection with the superstrings
+theory.",0201002v1
+2007-09-10,Hysteretic response of electron-nuclear spin system in single InAlAs quantum dots:Excitation power and polarization dependences,"We report the hysteresis of optically-pumped nuclear spin polarization and
+the degree of circular polarization of photoluminescence on the excitation
+power and electron spin polarization in single InAlAs quantum dots. By
+increasing (or decreasing) the excitation power at a particular excitation
+polarization, an abrupt rise (or drop) and a clear hysteretic behavior were
+observed in the Overhauser shift of the photoluminescence of the exciton and
+exciton complexes from the same single quantum dot under an external magnetic
+field of 5 T. However, the degree of circular polarization shows different
+behaviors between a positively charged exciton and a neutral exciton or
+biexciton; further, only positively charged exciton exhibits the precisely
+synchronized change and hysteretic behavior. It is suggested that the electron
+spin distribution is affected by the flip-flop of electron-nuclear spins.
+Further, the hysteresis is observed as a function of the degree of circular
+polarization of the excitation light and its dependence on the excitation power
+is studied. The saturation of the Overhauser shift after the abrupt rise
+indicates the almost complete cancellation of the external magnetic field by
+the nuclear field created within the width that is decided by the correlation
+time between the electron and the nuclei spin system.",0709.1382v1
+2007-10-04,A Defective Graphene Phase Predicted to be a Room Temperature Ferromagnetic Semiconductor,"Theoretical calculations, based on hybrid exchange density functional theory,
+are used to show that in graphene a periodic array of defects generates a
+ferromagnetic ground state at room temperature for unexpectedly large defect
+separations. This is demonstrated for defects that consist of a carbon vacancy
+in which two of the dangling bonds are saturated with H atoms. The magnetic
+coupling mechanism is analysed and found to be due to an instability in the
+$\pi$ electron system with respect to a long-range spin polarisation
+characterised by alternation in the spin direction between adjacent carbon
+atoms. The disruption of the $\pi$-bonding opens a semiconducting gap at the
+Fermi edge. The size of the energy gap and the magnetic coupling strength are
+strong functions of the defect separation and can thus be controlled by varying
+the defect concentration. The position of the semiconducting energy gap and the
+electron effective mass are strongly spin-dependent and this is expected to
+result in a spin asymmetry in the transport properties of the system. A
+defective graphene sheet is therefore a very promising material with an
+in-built mechanism for tailoring the properties of the spintronic devices of
+the future.",0710.0957v3
+2008-07-10,Modeling of Spin Metal-Oxide-Semiconductor Field-Effect-Transistor: A Non-Equilibrium Green's Function Approach with Spin Relaxation,"A spin metal-oxide-semiconductor field-effect-transistor (spin MOSFET), which
+combines a Schottky-barrier MOSFET with ferromagnetic source and drain
+contacts, is a promising device for spintronic logic. Previous simulation
+studies predict that this device should display a very high magnetoresistance
+(MR) ratio (between the cases of parallel and anti-parallel magnetizations) for
+the case of half-metal ferromagnets (HMF). We use the non-equilibrium Green's
+function (NEGF) formalism to describe tunneling and carrier transport in this
+device and to incorporate spin relaxation at the HMF-semiconductor interfaces.
+Spin relaxation at interfaces results in non-ideal spin injection. Minority
+spin currents arise and dominate the leakage current for anti-parallel
+magnetizations. This reduces the MR ratio and sets a practical limit for spin
+MOSFET performance. We found that MR saturates at a lower value for smaller
+source-to-drain bias. In addition, spin relaxation at the detector side is
+found to be more detrimental to MR than that at the injector side, for drain
+bias less than the energy difference of the minority spin edge and the Fermi
+level.",0807.1709v2
+2009-03-05,The theory of gyrokinetic turbulence: A multiple-scales approach,"Gyrokinetics is a rich and rewarding playground to study some of the
+mysteries of modern physics. In this thesis I present work, motivated by the
+quest for fusion energy, which seeks to uncover some of the inner workings of
+turbulence in magnetized plasmas.
+  I begin with the fundamental theory of gyrokinetics, and a novel formulation
+of its extension to the equations for mean-scale transport -- the equations
+which must be solved to determine the performance of magnetically confined
+fusion devices. The second project presents gyrokinetic secondary instability
+theory as a mechanism to bring about saturation of the basic instabilities that
+drive gyrokinetic turbulence. Emphasis is put on the ability for this analytic
+theory to predict basic properties of the nonlinear state, which can be applied
+to a mixing length phenomenology of transport. The final project is an
+application of the methods from inertial range understanding of fluid
+turbulence, to describe the stationary state of fully developed two-dimensional
+gyrokinetic turbulence. This work explores the relatively new idea of a
+phase-space cascade, whereby fine scales are nonlinearly generated in both
+position space and velocity space, and ultimately smoothed by collisional
+entropy production. This process constitutes the thermodynamic balance which
+occurs in the true steady state of a turbulent plasma, including those found in
+fusion devices.",0903.1091v2
+2009-03-13,"Epitaxial thin films of the multiferroic double perovskite Bi2FeCrO6 grown on (100)-oriented SrTiO3 substrates: Growth, characterization, and optimization","The influence of the deposition pressure PO2 and substrate temperature TS
+during the growth of Bi2FeCrO6 thin films grown by pulsed laser deposition has
+been investigated. It is found that the high volatility of Bi makes the
+deposition very difficult and that the growth of pure Bi2FeCrO6 thin films on
+SrTiO3 substrates is possible only in a narrow deposition parameter window. We
+find that the pure Bi2FeCrO6 phase is formed within a narrow window around an
+oxygen pressure PO2 =1.210-2 mbar and around a substrate temperature TS=680
+degC. At lower temperature or higher pressure, Bi7.38Cr0.62O12+x_also called
+(b*Bi2O3)and Bi2Fe4O9 /Bi2(Fe,Cr)4O9+x phases are detected, while at lower
+pressure or higher temperature a (Fe,Cr)3O4 phase forms. Some of these
+secondary phases are not well known and have not been previously studied. We
+previously reported Fe/Cr cation ordering as the probable origin of the tenfold
+improvement in magnetization at saturation of our Bi2FeCrO6 film, compared to
+BiFeO3. Here, we address the effect of the degree of cationic ordering on the
+magnetic properties of the Bi2FeCrO6 single phase. Polarization measurements at
+room temperature reveal that our Bi2FeCrO6 films have excellent ferroelectric
+properties with ferroelectric hysteresis loops exhibiting a remanent
+polarization as high as 55-60 miroC/cm2 along the pseudocubic (001) direction.",0903.2402v1
+2009-03-18,Superconductor-ferromagnet nanocomposites created by co-deposition of niobium and dysprosium,"We have created superconductor-ferromagnet composite films in order to test
+the enhancement of critical current density, Jc, due to magnetic pinning. We
+co-sputter the type-II superconductor niobium (Nb) and the low-temperature
+ferromagnet dysprosium (Dy) onto a heated substrate; the immiscibility of the
+two materials leads to a phase-separated composite of magnetic regions within a
+superconducting matrix. Over a range of compositions and substrate
+temperatures, we achieve phase separation on scales from 5 nm to 1 micron. The
+composite films exhibit simultaneous superconductivity and ferromagnetism.
+Transport measurements show that while the self-field Jc is reduced in the
+composites, the in-field Jc is greatly enhanced up to the 3 T saturation field
+of Dy. In one instance, the phase separation orders into stripes, leading to
+in-plane anisotropy in Jc.",0903.3142v2
+2009-04-07,Heat and Dust in Active Layers of Protostellar Disks,"Requirements for magnetic coupling and accretion in the active layer of a
+protostellar disk are re-examined, and some implications for thermal emission
+from the layer are discussed. The ionization and electrical conductivity are
+calculated following the general scheme of Ilgner and Nelson but with an
+updated UMIST database of chemical reactions and some improvements in the grain
+physics, and for the minimum-mass solar nebula rather than an alpha disk. The
+new limits on grain abundance are slightly more severe than theirs. Even for
+optimally sized grains, the layer should be at least marginally optically thin
+to its own thermal radiation, so that narrow, highly saturated emission lines
+of water and other molecular species would be expected if accretion is driven
+by turbulence and standard rates of ionization prevail. If the grain size
+distribution extends broadly from well below a micron to a millimeter or more,
+as suggested by observations, then the layer may be so optically thin that its
+cooling is dominated by molecular emission. Even under such conditions, it is
+difficult to have active layers of more than 10g/cm^2 near 1AU unless dust is
+entirely eliminated or greatly enhanced ionization rates are assumed.
+Equipartition-strength magnetic fields are then required in these regions of
+the disk if observed accretion rates are driven by magnetorotational
+turbulence. Wind-driven accretion might allow weaker fields and less massive
+active layers but would not heat the layer as much as turbulence and therefore
+might not produce emission lines.",0904.1240v2
+2009-08-26,On the strong impact of doping in the triangular antiferromagnet CuCrO2,"Electronic band structure calculations using the augmented spherical wave
+method have been performed for CuCrO2. For this antiferromagnetic (T_N = 24 K)
+semiconductor crystallizing in the delafossite structure, it is found that the
+valence band maximum is mainly due to the t_2g orbitals of Cr^3+ and that spin
+polarization is predicted with 3 mu_B per Cr^3+. The structural
+characterizations of CuCr1-xMgxO2 reveal a very limited range of Mg^2+
+substitution for Cr^3+ in this series. As soon as x = 0.02, a maximum of 1% Cr
+ions substituted by Mg site is measured in the sample. This result is also
+consistent with the detection of Mg spinel impurities from X-ray diffraction
+for x = 0.01. This explains the saturation of the Mg^2+ effect upon the
+electrical resistivity and thermoelectric power observed for x > 0.01. Such a
+very weak solubility limit could also be responsible for the discrepancies
+found in the literature. Furthermore, the measurements made under magnetic
+field (magnetic susceptibility, electrical resistivity and Seebeck coefficient)
+support that the Cr^4+ ""holes"", created by the Mg^2+ substitution, in the
+matrix of high spin Cr^3+ (S = 3/2) are responsible for the transport
+properties of these compounds.",0908.3828v1
+2009-09-16,Mn valence instability in La2/3Ca1/3MnO3 thin films,"A Mn valence instability on La2/3Ca1/3MnO3 thin films, grown on LaAlO3
+(001)substrates is observed by x-ray absorption spectroscopy at the Mn L-edge
+and O K-edge. As-grown samples, in situ annealed at 800 C in oxygen, exhibit a
+Curie temperature well below that of the bulk material. Upon air exposure a
+reduction of the saturation magnetization, MS, of the films is detected.
+Simultaneously a Mn2+ spectral signature develops, in addition to the expected
+Mn3+ and Mn4+ contributions, which increases with time. The similarity of the
+spectral results obtained by total electron yield and fluorescence yield
+spectroscopy indicates that the location of the Mn valence anomalies is not
+confined to a narrow surface region of the film, but can extend throughout the
+whole thickness of the sample. High temperature annealing at 1000 C in air,
+immediately after growth, improves the magnetic and transport properties of
+such films towards the bulk values and the Mn2+ signature in the spectra does
+not appear. The Mn valence is then stable even to prolonged air exposure. We
+propose a mechanism for the Mn2+ ions formation and discuss the importance of
+these observations with respect to previous findings and production of thin
+films devices.",0909.3037v1
+2010-01-12,Higher Winding Strings and Confined Monopoles in N=2 SQCD,"We consider composite string solutions in N=2 SQCD with the gauge group U(N),
+the Fayet--Iliopoulos term \xi \neq 0 and N (s)quark flavors. These bulk
+theories support non-Abelian strings and confined monopoles identified with
+kinks in the two-dimensional world-sheet theory. Similar and more complicated
+kinks (corresponding to composite confined monopoles) must exist in the
+world-sheet theories on composite strings. In a bid to detect them we analyze
+the Hanany--Tong (HT) model, focusing on a particular example of N=2. Unequal
+quark mass terms in the bulk theory result in the twisted masses in the N=(2,2)
+HT model. For spatially coinciding 2-strings, we find three distinct minima of
+potential energy, corresponding to three different 2-strings. Then we find
+BPS-saturated kinks interpolating between each pair of vacua. Two kinks can be
+called elementary. They emanate one unit of the magnetic flux and have the same
+mass as the conventional 't Hooft--Polyakov monopole on the Coulomb branch of
+the bulk theory (\xi =0). The third kink represents a composite bimonopole,
+with twice the minimal magnetic flux. Its mass is twice the mass of the
+elementary confined monopole. We find instantons in the HT model, and discuss
+quantum effects in composite strings at strong coupling. In addition, we study
+the renormalization group flow in this model.",1001.1903v1
+2010-04-23,Anisotropy of the in-plane angular magnetoresistance of electron-doed Sr1-xLaxCuO2 thin films,"Signatures of antiferromagnetism (AF) in the underdoped Ln2-xCexCuO4 (Ln =
+Nd, Pr,...) family are observed even for doping levels for which
+superconductivity exists. We have looked for a similar property in a different
+electron-doped cuprate family, Sr1-xLaxCuO2, which consists of CuO2 planes
+separated by Sr/La atoms, and is exempt of the possible influence of magnetic
+rare earth ions. We report in-plane magnetoresistance measurements in the
+normal state of underdoped, superconducting, c-axis oriented, epitaxial
+Sr1-xLaxCuO2 thin films. This probe is sensitive to spin arrangement and we
+find that the in-plane magnetoresistance, which is negative and does not
+saturate for T, exhibits an angular dependence when measured upon rotating a
+magnetic field within the CuO2 planes. The analysis reveals a superposition of
+fourfold and twofold angular oscillations. Both of these increase in amplitude
+with increasing field and decreasing and appear below a temperature, which gets
+higher with decreasing doping levels. Our results demonstrate that these
+magnetoresistance oscillations, also observed for the Ln2-xCexCuO4 (Ln = Nd,
+Pr,...) family and attributed to an AF signature, are, without ambiguity, a
+property of CuO2 planes. Besides, these oscillations vary with doping in an
+unusual way compared to previous results: fourfold oscillations are essentially
+present in the more underdoped samples while only twofold oscillations are
+visible in the less underdoped ones. This intriguing observation appears to be
+a consequence of spin dilution with increasing doping level.",1004.4163v1
+2010-09-03,Imaging Spectropolarimetry with IBIS II: on the fine structure of G-band bright features,"We present new results from first observations of the quiet solar photosphere
+performed through the Interferometric BIdimensional Spectrometer (IBIS) in
+spectropolarimetric mode. IBIS allowed us to measure the four Stokes parameters
+in the FeI 630.15 nm and FeI 630.25 nm lines with high spatial and spectral
+resolutions for 53 minutes; the polarimetric sensitivity achieved by the
+instrument is 0.003 the continuum intensity level. We focus on the correlation
+which emerges between G-band bright feature brightness and magnetic filling
+factor of ~ 1000 G (kG) fields derived by inverting Stokes I and V profiles.
+More in detail, we present the correlation first in a pixel-by-pixel study of
+an approximatively 3 arcsec wide bright feature (a small network patch) and
+then we show that such a result can be extended to all the bright features
+found in the dataset at any instant of the time sequence. The higher the kG
+filling factor associated to a feature the higher the brightness of the feature
+itself. Filling factors up to about 35 % are obtained for the brightest
+features. Considering the values of the filling factors derived from the
+inversion analysis of spectropolarimetric data and the brightness variation
+observed in G-band data we put forward an upper limit for the smallest scale
+over which magnetic flux concentrations in intergranular lanes produce a G-band
+brightness enhancement (~ 0.1''). Moreover, the brightness saturation observed
+for feature sizes comparable to the resolution of the observations is
+compatible with large G-band bright features being clusters of sub-arcsecond
+bright points. This conclusion deserves to be confirmed by forthcoming
+spectropolarimetric observations at higher spatial resolution.",1009.0721v1
+2011-02-16,Numerical Simulation of Current Sheet Formation in a Quasi-Separatrix Layer using Adaptive Mesh Refinement,"The formation of a thin current sheet in a magnetic quasi-separatrix layer
+(QSL) is investigated by means of numerical simulation using a simplified
+ideal, low-$\beta$, MHD model. The initial configuration and driving boundary
+conditions are relevant to phenomena observed in the solar corona and were
+studied earlier by Aulanier et al., A&A 444, 961 (2005). In extension to that
+work, we use the technique of adaptive mesh refinement (AMR) to significantly
+enhance the local spatial resolution of the current sheet during its formation,
+which enables us to follow the evolution into a later stage. Our simulations
+are in good agreement with the results of Aulanier et al. up to the calculated
+time in that work. In a later phase, we observe a basically unarrested collapse
+of the sheet to length scales that are more than one order of magnitude smaller
+than those reported earlier. The current density attains correspondingly larger
+maximum values within the sheet. During this thinning process, which is finally
+limited by lack of resolution even in the AMR studies, the current sheet moves
+upward, following a global expansion of the magnetic structure during the
+quasi-static evolution. The sheet is locally one-dimensional and the plasma
+flow in its vicinity, when transformed into a co-moving frame, qualitatively
+resembles a stagnation point flow. In conclusion, our simulations support the
+idea that extremely high current densities are generated in the vicinities of
+QSLs as a response to external perturbations, with no sign of saturation.",1102.3291v1
+2012-02-20,The contribution from blazar cascade emission to the extragalactic gamma-ray background: What a role does the extragalactic magnetic field play?,"We estimate the contribution to the extragalactic gamma-ray background (EGRB)
+from both intrinsic and cascade emissions produced by blazars using a simple
+semi- analysis method for two models of the blazar gamma-ray luminosity
+function (GLF). For the cascade emission, we consider two possible
+contributions: one is due to that the flux of the cascade emission is lower
+than the Fermi LAT sensitivity (case I), which is independent on the
+extragalactic magnetic field (EGMF), another is due to the fact that the flux
+of the cascade emission is larger than the Fermi LAT sensitivity but the
+emission angle is larger than LAT point-spread-function (PSF) angle (case II),
+which depends on the EGMF. Our results indicate that (1) blazar contribution to
+the EGRB is dominant although it depends on the GLF model and the EGMF; (2) the
+EGMF plays an important role in estimating the contribution from the cascade
+emission produced by blazars, the contribution from the cascade emission will
+significantly alter the EGRB spectrum when the strength of the EGMF is large
+enough (say BEGMF > 10-12 G); and (3) since the cascade emission in case II
+reaches a saturation when the strength of the EGMF is ? 10-11 G, it is very
+possible that the contribution from the cascade emission produced by blazars
+can be considered as another method to probe the upper limit of the strength of
+the EGMF.",1202.4250v1
+2012-04-04,Quantum phase transitions in the exactly solved spin-1/2 Heisenberg-Ising ladder,"Ground-state behaviour of the frustrated quantum spin-1/2 two-leg ladder with
+the Heisenberg intra-rung and Ising inter-rung interactions is examined in
+detail. The investigated model is transformed to the quantum Ising chain with
+composite spins in an effective transverse and longitudinal field by employing
+either the bond-state representation or the unitary transformation. It is shown
+that the ground state of the Heisenberg-Ising ladder can be descended from
+three exactly solvable models: the quantum Ising chain in a transverse field,
+the 'classical' Ising chain in a longitudinal field or the spin-chain model in
+a staggered longitudinal-transverse field. The last model serves in evidence of
+the staggered bond phase with alternating singlet and triplet bonds on the
+rungs of two-leg ladder, which appears at moderate values of the external
+magnetic field and consequently leads to a fractional plateau at a half of the
+saturation magnetization. The ground-state phase diagram totally consists of
+five ordered and one quantum disordered phase, which are separated from each
+other either by the lines of discontinuous or continuous quantum phase
+transitions. The order parameters are exactly calculated for all five ordered
+phases and the quantum disordered phase is characterized through different
+short-range spin-spin correlations.",1204.1008v2
+2012-05-01,A quasi-analytical model for energy-delay-reliability tradeoff studies during write operations in perpendicular STT-RAM cell,"One of the biggest challenges the current STT-RAM industry faces is
+maintaining a high thermal stability while trying to switch within a given
+voltage pulse and energy cost. In this paper, we present a physics based
+analytical model that uses a modified Simmons' tunneling expression to capture
+the spin dependent tunneling in a magnetic tunnel junction(MTJ). Coupled with
+an analytical derivation of the critical switching current based on the
+Landau-Lifshitz-Gilbert equation, and the write error rate derived from a
+solution to the Fokker-Planck equation, this model provides us a quick estimate
+of the energydelay- reliability tradeoffs in perpendicular STTRAMs due to
+thermal fluctuations. In other words, the model provides a simple way to
+calculate the energy consumed during a write operation that ensures a certain
+error rate and delay time, while being numerically far less intensive than a
+full-fledged stochastic calculation. We calculate the worst case energy
+consumption during anti-parallel (AP) to parallel (P) and P to AP switchings
+and quantify how increasing the anisotropy field HK and lowering the saturation
+magnetization MS, can significantly reduce the energy consumption. A case study
+on how manufacturing variations of the MTJ cell can affect the energy
+consumption and delay is also reported.",1205.0183v1
+2012-06-06,Cosmic-ray acceleration in supernova remnants: non-linear theory revised,"A rapidly growing amount of evidences, mostly coming from the recent
+gamma-ray observations of Galactic supernova remnants (SNRs), is seriously
+challenging our understanding of how particles are accelerated at fast shocks.
+The cosmic-ray (CR) spectra required to account for the observed phenomenology
+are in fact as steep as $E^{-2.2}--E^{-2.4}$, i.e., steeper than the
+test-particle prediction of first-order Fermi acceleration, and significantly
+steeper than what expected in a more refined non-linear theory of diffusive
+shock acceleration. By accounting for the dynamical back-reaction of the
+non-thermal particles, such a theory in fact predicts that the more efficient
+the particle acceleration, the flatter the CR spectrum. In this work we put
+forward a self-consistent scenario in which the account for the magnetic field
+amplification induced by CR streaming produces the conditions for reversing
+such a trend, allowing --- at the same time --- for rather steep spectra and CR
+acceleration efficiencies (about 20%) consistent with the hypothesis that SNRs
+are the sources of Galactic CRs. In particular, we quantitatively work out the
+details of instantaneous and cumulative CR spectra during the evolution of a
+typical SNR, also stressing the implications of the observed levels of
+magnetization on both the expected maximum energy and the predicted CR
+acceleration efficiency. The latter naturally turns out to saturate around
+10-30%, almost independently of the fraction of particles injected into the
+acceleration process as long as this fraction is larger than about $10^{-4}$.",1206.1360v1
+2012-06-07,Anisotropic magnetothermoelectric power of ferromagnetic thin films,"We compare the behavior of the magnetothermoelectric power (MTEP)in metallic
+ferromagnetic thin films of Ni80Fe20 (Permalloy; Py), Co and CrO2 at
+temperatures in the range of 100 K to 400 K. In 25 nm thick Py films and 50 nm
+thick Co films both the anisotropic magnetoresistance (AMR) and MTEP show a
+relative change in resistance and thermoelectric power (TEP) of the order of
+0.2% when the magnetic field is reversed, and in both cases there is no
+significant change in AMR or MTEP any more after the saturation field has been
+reached. Surprisingly, both Py and Co films have opposite MTEP behavior
+although both have the same sign for AMR and TEP. The data on 100 nm films of
+fully spin-polarized CrO2, grown both on TiO2 and on sapphire, show a different
+picture. The MTEP behavior at low fields shows peaks similar to the AMR in
+these films, with variations up to 1%. With increasing field both the MR and
+the MTEP variations keeps growing, with MTEP showing relative changes of 1.5%
+with the thermal gradient along the b-axis and even 20% with the gradient along
+the c-axis, with an intermediate value of 3% for the film on sapphire. It
+appears that the low-field effects are due to magnetic domain switching, while
+the high-field effects are intrinsic to the electronic structure of CrO2.",1206.1527v2
+2012-10-16,Interaction-induced charge and spin pumping through a quantum dot at finite bias,"We investigate charge and spin transport through an adiabatically driven,
+strongly interacting quantum dot weakly coupled to two metallic contacts with
+finite bias voltage. Within a kinetic equation approach, we identify
+coefficients of response to the time-dependent external driving and relate
+these to the concepts of charge and spin emissivities previously discussed
+within the time-dependent scattering matrix approach. Expressed in terms of
+auxiliary vector fields, the response coefficients allow for a straightforward
+analysis of recently predicted interaction-induced pumping under periodic
+modulation of the gate and bias voltage [Phys. Rev. Lett. 104, 226803 (2010)].
+We perform a detailed study of this effect and the related adiabatic Coulomb
+blockade spectroscopy, and, in particular, extend it to spin pumping. Analytic
+formulas for the pumped charge and spin in the regimes of small and large
+driving amplitude are provided for arbitrary bias. In the absence of a magnetic
+field, we obtain a striking, simple relation between the pumped charge at zero
+bias and at bias equal to the Coulomb charging energy. At finite magnetic
+field, there is a possibility to have interaction-induced pure spin pumping at
+this finite bias value, and generally, additional features appear in the pumped
+charge. For large-amplitude adiabatic driving, the magnitude of both the pumped
+charge and spin at the various resonances saturate at values which are
+independent of the specific shape of the pumping cycle. Each of these values
+provide an independent, quantitative measurement of the junction asymmetry.",1210.4452v1
+2012-12-10,Proton temperature anisotropy and magnetic reconnection in the solar wind: effects of kinetic instabilities on current sheet stability,"We investigate the role of kinetic instabilities driven by a proton
+anisotropy on the onset of magnetic reconnection by means of 2-D hybrid
+simulations. The collisionless tearing of a current sheet is studied in the
+presence of a proton temperature anisotropy in the surrounding plasma. Our
+results confirm that anisotropic protons within the current sheet region can
+significantly enhance/stabilize the tearing instability of the current.
+Moreover, fluctuations associated to linear instabilities excited by large
+proton temperature anisotropies can significantly influence the stability of
+the plasma and perturb the current sheets, triggering the tearing instability.
+We find that such a complex coupling leads to a faster tearing evolution in a
+regime with larger perpendicular temperature when an ion-cyclotron instability
+is generated by the anisotropic proton distribution functions. On the contrary,
+in the presence of the opposite anisotropy, fire hose fluctuations excited by
+the unstable background protons with larger parallel temperature are not able
+to efficiently destabilize the current sheets, which remain stable for a long
+time after fire hose saturation. We discuss possible influences of this novel
+coupling on the solar wind and heliospheric plasma dynamics.",1212.2101v1
+2013-04-18,"Magnetostructural transition, metamagnetism, and magnetic phase coexistence in Co10Ge3O16","Co10Ge3O16 crystallizes in an intergrowth structure featuring alternating
+layers of spinel and rock salt. Variable-temperature powder synchrotron X-ray
+and neutron diffraction, magnetometry, and heat capacity experiments reveal a
+magnetostructural transition at T_N = 203 K. This rhombohedral-to-monoclinic
+transition involves a slight elongation of the CoO6 octahedra along the apical
+axis. Below T_N, the application of a large magnetic field causes a
+reorientation of the Co^2+ Ising spins. This metamagnetic transition is
+first-order as evidenced by a latent heat observed in temperature-dependent
+measurements. This transition is initially seen at T = 180 K as a broad upturn
+in the M-H near H_C = 3.9 T. The upturn sharpens into a kink at T = 120 K and a
+""butterfly"" shape emerges, with the transition causing hysteresis at high
+fields while linear and reversible behavior persists at low fields. H_C
+decreases as temperature is lowered and the loops at positive and negative
+fields merge beneath T = 20 K. The antiferromagnetism is described by k_M = (00
+1/2) and below T = 20 K a small uncompensated component with k_M = (000)
+spontaneously emerges. Despite the Curie-Weiss analysis and ionic radius
+indicating the Co2+ is in its high-spin state, the low-temperature M-H trends
+toward saturation at M_S = 1.0 uB/Co. We conclude that the field-induced state
+is a ferrimagnet, rather than a S = 1/2 ferromagnet. The unusual H-T phase
+diagram is discussed with reference to other metamagnets and Co(II) systems.",1304.5000v3
+2013-05-14,Effects of local dissipation profiles on magnetized accretion disk spectra,"We present spectral calculations of non-LTE accretion disk models appropriate
+for high luminosity stellar mass black hole X-ray binary systems. We first use
+a dissipation profile based on scaling the results of shearing box simulations
+of Hirose et al. (2009) to a range of annuli parameters. We simultaneously
+scale the effective temperature, orbital frequency and surface density with
+luminosity and radius according to the standard \alpha-model (Shakura &
+Sunyaev, 1973). This naturally brings increased dissipation to the disk surface
+layers (around the photospheres) at small radii and high luminosities. We find
+that the local spectrum transitions directly from a modified black body to a
+saturated Compton scattering spectrum as we increase the effective temperature
+and orbital frequency while decreasing midplane surface density. Next, we
+construct annuli models based on the parameters of a L/L_Edd=0.8 disk orbiting
+a 6.62 solar mass black hole using two modified dissipation profiles that
+explicitly put more dissipation per unit mass near the disk surface. The new
+dissipation profiles are qualitatively similar to the one found by Hirose et
+al. (2009), but produce strong near power-law spectral tails. Our models also
+include physically motivated magnetic acceleration support based once again on
+scaling the Hirose et al. (2009) results. We present three full-disk spectra
+each based on one of the dissipation prescriptions. Our most aggressive
+dissipation profile results in a disk spectrum that is in approximate
+quantitative agreement with certain observations of the steep power law (SPL)
+spectral states from some black hole X-ray binaries.",1305.3320v1
+2013-07-23,Resistance asymmetry of a two-dimensional electron gas caused by an effective spin injection,"We have performed conductivity measurements on a Si-MOSFET sample with a slot
+in the upper gate, allowing for different electron densities n_1 and n_2 across
+the slot. Dynamic longitudinal resistance was measured by a standard lock-in
+technique, while maintaining a large DC current through the source-drain
+channel. We find that in a parallel magnetic field, the resistance of the
+sample, R(I_DC), is asymmetric with respect to the direction of the DC current.
+The asymmetry becomes stronger with an increase of either the magnetic field or
+the difference between n_1 and n_2. These observations are interpreted in terms
+of the effective spin injection: the degree of spin polarisation is different
+in the two parts of the sample, implying different magnitudes of spin current
+away from the slot. The carriers thus leave the excess spin (of the appropriate
+sign) in the region around the slot, leading to spin accumulation (or
+depletion) and to the spin drift-diffusion phenomena. Due to the positive
+magnetoresistance of the two-dimensional electron gas, this change in a local
+magnetisation affects the resistivity near the slot and the measured net
+resistance, giving rise to an asymmetric contribution. We further observe that
+the value of R(I_DC) saturates at large I_DC; we suggest that this is due to
+electron tunnelling from the two-dimensional n-type layer into the p-type
+silicon (or into another ""spin reservoir"") at the slot.",1307.6260v2
+2013-12-20,Magnon condensation with finite degeneracy on the triangular lattice,"We study the spin 1/2 triangular-lattice $J_1$-$J_2$-$J_3$ antiferromagnet
+close to the saturation field using the dilute Bose gas theory, where the
+magnetic structure is determined by the condensation of magnons. We focus on
+the case of ferromagnetic $J_1$ and antiferromagnetic $J_2,J_3$, that is
+particularly rich because frustration effects allow the single-magnon energy
+dispersion to have six-fold degenerate minima at incommensurate momenta. Our
+calculation also includes an interlayer coupling $J_0$, which covers both
+antiferromagnetic and ferromagnetic cases including negligibly small regime
+(two-dimensional case). Besides the spiral and fan phases, we find a new
+double-$q$ phase (superposition of two modes), dubbed ""${\bf Q}_0$-${\bf Q}_1$""
+(or simply ""01"") phase, that enjoys a new type of multiferroic character.
+Certain phase boundaries have a singular $J_0$ dependence for $J_0\to 0$,
+implying that even a very small interlayer coupling drastically changes the
+ground state. A mechanism for this singularity is presented. Moreover, in some
+regions of the parameter space, we show that a dilute gas of magnons can not be
+stable, and phase separation (corresponding to a magnetization jump) is
+expected. In the $J_1$-$J_2$ model ($J_3=0$), formation of two-magnon bound
+states is observed, which can lead to a quadrupolar (spin-nematic) ordered
+phase. Exact diagonalization analysis is also applied to the search of bound
+states.",1312.5935v2
+2014-02-06,Scattering mechanisms in textured FeGe thin films: magnetoresistance and the anomalous Hall effect,"A textured thin film of FeGe was grown by magnetron sputtering with a
+helimagnetic ordering temperature of TN = 276 +/- 2 K. From 5 K to room
+temperature a variety of scattering processes contribute towards the overall
+longitudinal and Hall resistivities. These were studied by combining
+magnetometry and magnetotransport measurements. The high-field
+magnetoresistance (MR) displays three clear temperature regimes: Lorentz force
+MR dominates at low temperatures, above T ~ 80 K scattering from spin-waves
+predominates, whilst finally for T > 200 K scattering from fluctuating local
+moments describes the MR. At low fields, where the magnetisation is no longer
+technically saturated, we find a scaling of magnetoresistance with the square
+of the magnetisation, indicating that the MR due to the unwinding of spins in
+the conical phase arises from a similar mechanism to that in magnetic domain
+walls. This MR is only visible up to a temperature of about 200 K. No features
+can be found in the temperature or field dependence of the longitudinal
+resistivity that belie the presence of the underlying magnetic phase transition
+at TN: the marked changes in behavior are at much lower temperatures. The
+anomalous Hall effect has a dramatic temperature dependence in which the
+anomalous Hall resistivity scales quadratically with the longitudinal
+resistivity: comparison with anomalous Hall scaling theory shows that our
+system is in the intrinsic 'moderately dirty' regime. Lastly, we find evidence
+of a topological Hall effect of size 100 ~Ohm cm.",1402.1276v2
+2014-06-14,MuSR Investigation and Suppression of TC by overdoped Li in Diluted Ferromagnetic Semiconductor Li1+y(Zn1-xMnx)P,"We use muon spin relaxation (muSR) to investigate the magnetic properties of
+a bulk form diluted ferromagnetic semiconductor (DFS) Li1.15(Zn0.9Mn0.1)P with
+T_C ~ 22 K. MuSR results confirm the gradual development of ferromagnetic
+ordering below T_C with a nearly 100% magnetic ordered volume. Despite its low
+carrier density, the relation between static internal field and Curie
+temperature observed for Li(Zn,Mn)P is consistent with the trend found in
+(Ga,Mn)As and other bulk DFSs, indicating these systems share a common
+mechanism for the ferromagnetic exchange interaction. Li1+y(Zn1-xMnx)P has the
+advantage of decoupled carrier and spin doping, where Mn2+ substitution for
+Zn2+ introduces spins and Li+ off-stoichiometry provides carriers. This
+advantage enables us to investigate the influence of overdoped Li on the
+ferromagnetic ordered state. Overdoping Li suppresses both T_C and saturation
+moments for a certain amount of spins, which indicates that more carriers are
+detrimental to the ferromagnetic exchange interaction, and that a delicate
+balance between charge and spin densities is required to achieve highest T_C.",1406.3744v1
+2014-08-26,Generalized investigation of the rotation-activity relation: Favouring rotation period instead of Rossby number,"Magnetic activity in Sun-like and low-mass stars causes X-ray coronal
+emission, which is stronger for more rapidly rotating stars. This relation is
+often interpreted in terms of the Rossby number, i.e., the ratio of rotation
+period to convective overturn time. We reconsider this interpretation on the
+basis of the observed X-ray emission and rotation periods of 821 stars with
+masses below 1.4 Msun. A generalized analysis of the relation between X-ray
+luminosity normalized by bolometric luminosity, L_X/L_bol, and combinations of
+rotational period, P, and stellar radius, R, shows that the Rossby formulation
+does not provide the solution with minimal scatter. Instead, we find that the
+relation L_X/L_bol ~ P^{-2}R^{-4} optimally describes the non-saturated
+fraction of the stars. This relation is equivalent to L_X ~ P^{-2}, indicating
+that the rotation period alone determines the total X-ray emission. Since L_X
+is directly related to the magnetic flux at the stellar surface, this means
+that the surface flux is determined solely by the star's rotation and is
+independent of other stellar parameters. While a formulation in terms of a
+Rossby number would be consistent with these results if the convective overturn
+time scales exactly as L_bol^{-1/2}, our generalized approach emphasizes the
+need to test a broader range of mechanisms for dynamo action in cool stars.",1408.6175v1
+2014-09-16,Interacting tilt and kink instabilities in repelling current channels,"We present a numerical study in resistive magnetohydrodynamics where the
+initial equilibrium configuration contains adjacent, oppositely directed,
+parallel current channels. Since oppositely directed current channels repel,
+the equilibrium is liable to an ideal magnetohydrodynamic tilt instability.
+This tilt evolution, previously studied in planar settings, involves two
+magnetic islands or fluxropes, which on Alfvenic timescales undergo a combined
+rotation and separation. This in turn leads to the creation of (near) singular
+current layers, posing severe challenges to numerical approaches. Using our
+open-source grid-adaptive MPI-AMRVAC software, we revisit the planar evolution
+case in compressible MHD, as well as its extension to 2.5D and full 3D
+scenarios. As long as the third dimension remains ignorable, pure tilt
+evolutions result which are hardly affected by out of plane magnetic field
+components. In all 2.5D runs, our simulations do show secondary tearing type
+disruptions throughout the near singular current sheets in the far nonlinear
+saturation regime. In full 3D, both current channels can be liable to
+additional ideal kink deformations. We discuss the effects of having both tilt
+and kink instabilities acting simultaneously in the violent, reconnection
+dominated evolution. In 3D, both the tilt and the kink instabilities can be
+stabilized by tension forces. As a concrete space plasma application, we argue
+that interacting tilt-kink instabilities in repelling current channels provide
+a novel route to initiate solar coronal mass ejections, distinctly different
+from currently favored pure kink or torus instability routes.",1409.4543v1
+2014-09-18,Permutation Entropy and Statistical Complexity Analysis of Turbulence in Laboratory Plasmas and the Solar Wind,"The Bandt-Pompe permutation entropy and the Jensen-Shannon statistical
+complexity are used to analyze fluctuating time series of three different
+plasmas: the magnetohydrodynamic (MHD) turbulence in the plasma wind tunnel of
+the Swarthmore Spheromak Experiment (SSX), drift-wave turbulence of ion
+saturation current fluctuations in the edge of the Large Plasma Device (LAPD)
+and fully-developed turbulent magnetic fluctuations of the solar wind taken
+from the WIND spacecraft. The entropy and complexity values are presented as
+coordinates on the CH plane for comparison among the different plasma
+environments and other fluctuation models. The solar wind is found to have the
+highest permutation entropy and lowest statistical complexity of the three data
+sets analyzed. Both laboratory data sets have larger values of statistical
+complexity, suggesting these systems have fewer degrees of freedom in their
+fluctuations, with SSX magnetic fluctuations having slightly less complexity
+than the LAPD edge fluctuations. The CH plane coordinates are compared to the
+shape and distribution of a spectral decomposition of the waveforms. These
+results suggest that fully developed turbulence (solar wind) occupies the
+lower-right region of the CH plane, and that other plasma systems considered to
+be turbulent have less permutation entropy and more statistical complexity.
+This paper presents the first use of this statistical analysis tool on solar
+wind plasma, as well as on an MHD turbulent experimental plasma.",1409.5455v1
+2014-11-21,A new spin gapless semiconductor: quaternary Heusler CoFeCrGa alloy,"Despite a plethora of materials suggested for spintronic applications, a new
+class of materials has emerged, namely spin gapless semiconductors (SGS), that
+offers potentially more advantageous properties than existing ones. These
+magnetic semiconductors exhibit a finite band gap for one spin channel and a
+closed gap for the other. Here, supported by the first-principles,
+electronic-structure calculations, we report the first experimental evidence of
+SGS behavior in equiatomic quaternary CoFeCrGa, having a cubic Heusler (L21)
+structure but exhibiting chemical disorder (DO3 structure). CoFeCrGa is found
+to transform from SGS to half-metallic phase under pressure, which is
+attributed to unique electronic-structure features. The saturation
+magnetization (MS) obtained at 8 K agrees with the Slater-Pauling rule and the
+Curie temperature (TC) is found to exceed 400 K. Carrier concentration (up to
+250 K) and electrical conductivity are observed to be nearly temperature
+independent, prerequisites for SGS. The anomalous Hall coefficient is estimated
+to be 185 S/cm at 5 K. Considering the SGS properties and high TC, this
+material appears to be promising for spintronic applications.",1411.5772v2
+2015-02-15,Extremely large magnetoresistance and ultrahigh mobility in the topological Weyl semimetal NbP,"Recent experiments have revealed spectacular transport properties of
+conceptually simple semimetals. For example, normal semimetals (e.g. WTe$_2$)
+have started a new trend to realize a large magnetoresistance, which is the
+change of electrical resistance by an external magnetic field. Weyl semimetal
+(WSM) is a topological semimetal with massless relativistic electrons as the
+three-dimensional analogue of graphene and promises exotic transport properties
+and surface states, which are different from those of the famous topological
+insulators (TIs). In this letter, we choose to utilize NbP in magneto-transport
+experiments because its band structure is on assembly of a WSM and a normal
+semimetal. Such a combination in NbP indeed leads to the observation of
+remarkable transport properties, an extremely large magnetoresistance of
+850,000 % at 1.85 K (250 % at room temperature) in a magnetic field of 9 T
+without any signs of saturation, and ultrahigh carrier mobility of
+5$\times$10$^6$ cm$^2$ V$^{-1}$ s$^{-1}$ accompanied by strong Shubnikov-de
+Hass (SdH) oscillations. NbP presents a unique example to consequent design the
+functionality of materials by combining the topological and conventional
+phases.",1502.04361v2
+2015-05-06,Role of spin-orbit coupling and evolution of the electronic structure of WTe$_2$ under an external magnetic field,"Here, we present a detailed study on the temperature and angular dependence
+of the Shubnikov-de-Haas (SdH) effect in the semi-metal WTe$_2$. This compound
+was recently shown to display a very large non-saturating magnetoresistance
+which was attributed to nearly perfectly compensated densities of electrons and
+holes. We observe four fundamental SdH frequencies and attribute them to
+spin-orbit split, electron- and hole-like, Fermi surface (FS) cross-sectional
+areas. Their angular dependence seems consistent with ellipsoidal FSs with
+volumes suggesting a modest excess in the density of electrons with respect to
+that of the holes. We show that density functional theory (DFT) calculations
+fail to correctly describe the FSs of WTe$_2$. When their cross-sectional areas
+are adjusted to reflect the experimental data, the resulting volumes of the
+electron/hole FSs obtained from the DFT calculations would imply a pronounced
+imbalance between the densities of electrons and holes. We find evidence for
+field-dependent Fermi surface cross-sectional areas by fitting the oscillatory
+component superimposed onto the magnetoresistivity signal to several
+Lifshitz-Kosevich components. We also observe a pronounced field-induced
+renormalization of the effective masses. Taken together, our observations
+suggest that the electronic structure of WTe$_2$ evolves with the magnetic
+field. This evolution might be a factor contributing to its pronounced
+magnetoresistivity.",1505.01242v2
+2016-03-01,Suppression of thermal conduction in a mirror-unstable plasma,"The ICM plasma is subject to firehose and mirror instabilities at scales of
+order the ion Larmor radius. The mirror instability generates fluctuations of
+magnetic-field strength $\delta B / B \sim 1$. These fluctuations act as
+magnetic traps for the heat-conducting electrons, suppressing their transport.
+We calculate the effective parallel thermal conductivity in the ICM in the
+presence of the mirror fluctuations for different stages of the evolution of
+the instability. The mirror fluctuations are limited in amplitude by the
+maximum and minimum values of the field strength, with no large deviations from
+the mean value. This key property leads to a finite suppression of thermal
+conduction at large scales. We find suppression down to $\approx 0.2$ of the
+Spitzer value for the secular phase of the perturbations' growth, and $\approx
+0.3$ for their saturated phase. The effect operates in addition to other
+suppression mechanisms and independently of them. Globally, fluctuations
+$\delta B / B \sim 1$ can be present on much larger scales, of the order of the
+scale of turbulent motions. However, we do not expect large suppression of
+thermal conduction by these, because their scale is considerably larger than
+the collisional mean free path of the ICM electrons. The obtained suppression
+of thermal conduction by a factor of $\sim 5$ appears to be characteristic and
+potentially universal for a weakly collisional mirror-unstable plasma.",1603.00524v3
+2016-03-23,Multi-photon transitions and Rabi resonance in continuous wave EPR,"The study of microwave and radiofrequency multi-photon transitions in
+continuous wave (CW) EPR spectroscopy is extended to a Rabi resonance
+condition, when the radio frequency of the magnetic-field modulation matches
+the Rabi frequency of a spin system in the microwave field. Using the
+non-secular perturbation theory based on the Bogoliubov averaging method, the
+analytical description of the response of the spin system is derived for all
+modulation frequency harmonics. When the modulation frequency exceeds the EPR
+linewidth, multi-photon transitions result in sidebands in absorption EPR
+spectra measured with phase-sensitive detection at any harmonic. The saturation
+of different-order multi-photon transitions is shown to be significantly
+different and to be sensitive to the Rabi resonance. The noticeable frequency
+shifts of sidebands are found to be the signatures of this resonance. The
+inversion of two-photon lines in some spectral intervals of the out-of-phase
+first-harmonic signal is predicted under passage through the Rabi resonance.
+The inversion indicates the transition from absorption to stimulated emission
+or vice versa, depending on the sideband. The manifestation of the primary and
+secondary Rabi resonance is also demonstrated in time-resolved steady-state EPR
+signals formed by all harmonics of the modulation frequency. Our results
+provide a theoretical framework for future developments in multi-photon CW EPR
+spectroscopy, which can be useful for samples with long spin relaxation times
+and extremely narrow EPR lines",1603.07228v1
+2016-05-11,Percolation via combined electrostatic and chemical doping in complex oxide films,"Stimulated by experimental advances in electrolyte gating methods, we
+investigate theoretically percolation in thin films of inhomogenous complex
+oxides, such as La$_{1-x}$Sr$_{x}$CoO$_{3}$ (LSCO), induced by a combination of
+bulk chemical and surface electrostatic doping. Using numerical and analytical
+methods, we identify two mechanisms that describe how bulk dopants reduce the
+amount of electrostatic surface charge required to reach percolation: (i)
+bulk-assisted surface percolation, and (ii) surface-assisted bulk percolation.
+We show that the critical surface charge strongly depends on the film thickness
+when the film is close to the chemical percolation threshold. In particular,
+thin films can be driven across the percolation transition by modest surface
+charge densities \emph{via} surface-assisted bulk percolation. If percolation
+is associated with the onset of ferromagnetism, as in LSCO, we further
+demonstrate that the presence of critical magnetic clusters extending from the
+film surface into the bulk results in considerable volume enhancement of the
+saturation magnetization, with pronounced experimental consequences. These
+results should significantly guide experimental work seeking to verify
+gate-induced percolation transitions in such materials.",1605.03463v1
+2016-05-12,Intertwined Lattice Deformation and Magnetism in Monovacancy Graphene,"Using density functional calculations we have investigated the local spin
+moment formation and lattice deformation in graphene when an isolated vacancy
+is created. We predict two competing equilibrium structures: a ground state
+planar configuration with a saturated local moment of 1.5 $\mu_B$, and a
+metastable non-planar configuration with a vanishing magnetic moment, at a
+modest energy expense of ~50 meV. Though non-planarity relieves the lattice of
+vacancy-induced strain, the planar state is energetically favored due to
+maximally localized defect states (v$\sigma$, v$\pi$). In the planar
+configuration, charge transfer from itinerant (Dirac) states weakens the
+spin-polarization of v$\pi$ yielding a fractional moment, which is aligned
+parallel to the unpaired v$\sigma$ electron through Hund's coupling. In the
+non-planar configuration, the absence of orthogonal symmetry allows interaction
+between v$\sigma$ and local d$\pi$ states, to form a hybridized
+v$\sigma^\prime$ state. The non-orthogonality also destabilizes the Hund's
+coupling, and an antiparallel alignment between v$\sigma$ and v$\pi$ lowers the
+energy. The gradual spin reversal of v$\pi$ with increasing non-planarity opens
+up the possibility of an intermediate structure with balanced v$\pi$ spin
+population. If such a structure is realized under external perturbations,
+diluted vacancy concentration may lead to v$\sigma$ based spin-1/2
+paramagnetism.",1605.03921v1
+2016-06-11,"Conetronics in 2D Metal-Organic Frameworks: Double Dirac Cones, Magnetic Half Dirac Cones and Quantum Anomalous Hall Effect","Based on recently synthesized Ni3C12S12 class 2D metal-organic frameworks, we
+predict electronic properties of M3C12S12 and M3C12O12, where M is Zn, Cd, Hg,
+Be, or Mg with no M orbital contributions to bands near Fermi level. For
+M3C12S12, their band structures exhibit double Dirac cones with different Fermi
+velocities that are n and p type, respectively, which are switchable by
+few-percent strain. The crossing of two cones are symmetry-protected to be
+non-hybridizing, leading to two independent channels in 2D node-line semimetals
+at the same k-point akin to spin-channels in spintronics, rendering conetronics
+device possible. The node line rings right at their crossing, which are both
+electron and hole pockets at the Fermi level, can give rise to
+magnetoresistance that will not saturate when the magnetic field is infinitely
+large, due to perfect n-p compensation. For M3C12O12, together with conjugated
+metal-tricatecholate polymers M3(HHTP)2, the spin-polarized slow Dirac cone
+center is pinned precisely at the Fermi level, making the systems conducting in
+only one spin or cone channel. Quantum anomalous Hall effect can arise in MOFs
+with non-negligible spin-orbit coupling like Cu3C12O12. Compounds of M3C12S12
+and M3C12O12 with different M, can be used to build spintronic and
+cone-selecting heterostructure devices, tunable by strain or electrostatic
+gating.",1606.04094v1
+2016-08-24,The Weak Gravity Conjecture and Effective Field Theory,"The Weak Gravity Conjecture (WGC) is a proposed constraint on theories with
+gauge fields and gravity, requiring the existence of light charged particles
+and/or imposing an upper bound on the field theory cutoff $\Lambda$. If taken
+as a consistency requirement for effective field theories (EFTs), it rules out
+possibilities for model-building including some models of inflation. I
+demonstrate simple models which satisfy all forms of the WGC, but which through
+Higgsing of the original gauge fields produce low-energy EFTs with gauge forces
+that badly violate the WGC. These models illustrate specific loopholes in
+arguments that motivate the WGC from a bottom-up perspective; for example the
+arguments based on magnetic monopoles are evaded when the magnetic confinement
+that occurs in a Higgs phase is accounted for. This indicates that the WGC
+should not be taken as a veto on EFTs, even if it turns out to be a robust
+property of UV quantum gravity theories. However, if the latter is true then
+parametric violation of the WGC at low energy comes at the cost of non-minimal
+field content in the UV. I propose that only a very weak constraint is
+applicable to EFTs, $\Lambda \lesssim \left(-\log g \right)^{-1/2} M_\text{pl}$
+where $g$ is the gauge coupling, motivated by entropy bounds. Remarkably, EFTs
+produced by Higgsing a theory that satisfies the WGC can saturate but not
+violate this bound.",1608.06951v2
+2016-09-30,Superconductivity mediated by quantum critical antiferromagnetic fluctuations: The rise and fall of hot spots,"In several unconventional superconductors, the highest superconducting
+transition temperature $T_{c}$ is found in a region of the phase diagram where
+the antiferromagnetic transition temperature extrapolates to zero, signaling a
+putative quantum critical point. The elucidation of the interplay between these
+two phenomena - high-$T_{c}$ superconductivity and magnetic quantum criticality
+- remains an important piece of the complex puzzle of unconventional
+superconductivity. In this paper, we combine sign-problem-free Quantum Monte
+Carlo simulations and field-theoretical analytical calculations to unveil the
+microscopic mechanism responsible for the superconducting instability of a
+general low-energy model, called spin-fermion model. In this approach,
+low-energy electronic states interact with each other via the exchange of
+quantum critical magnetic fluctuations. We find that even in the regime of
+moderately strong interactions, both the superconducting transition temperature
+and the pairing susceptibility are governed not by the properties of the entire
+Fermi surface, but instead by the properties of small portions of the Fermi
+surface called hot spots. Moreover, $T_{c}$ increases with increasing
+interaction strength, until it starts to saturate at the crossover from
+hot-spots dominated to Fermi-surface dominated pairing. Our work provides not
+only invaluable insights into the system parameters that most strongly affect
+$T_{c}$, but also important benchmarks to assess the origin of
+superconductivity in both microscopic models and actual materials.",1609.09568v2
+2016-10-04,Equation of State for Nucleonic and Hyperonic Neutron Stars with Mass and Radius Constraints,"We obtain a new equation of state for the nucleonic and hyperonic inner core
+of neutron stars that fulfills the 2$M_{\odot}$ observations as well as the
+recent determinations of stellar radii below 13 km. The nucleonic equation of
+state is obtained from a new parametrization of the FSU2 relativistic
+mean-field functional that satisfies these latest astrophysical constraints
+and, at the same time, reproduces the properties of nuclear matter and finite
+nuclei while fulfilling the restrictions on high-density matter deduced from
+heavy-ion collisions. On the one hand, the equation of state of neutron star
+matter is softened around saturation density, which increases the compactness
+of canonical neutron stars leading to stellar radii below 13 km. On the other
+hand, the equation of state is stiff enough at higher densities to fulfill the
+2$M_{\odot}$ limit. By a slight modification of the parametrization, we also
+find that the constraints of 2$M_{\odot}$ neutron stars with radii around 13 km
+are satisfied when hyperons are considered. The inclusion of the high magnetic
+fields present in magnetars further stiffens the equation of state. Hyperonic
+magnetars with magnetic fields in the surface of $ \sim 10^{15}$ G and with
+values of $\sim 10^{18}$ G in the interior can reach maximum masses of
+2$M_{\odot}$ with radii in the 12-13 km range.",1610.00919v2
+2016-12-17,"Upper critical field, pressure-dependent superconductivity and electronic anisotropy of Sm$_4$Fe$_2$As$_2$Te$_{1-x}$O$_{4-y}$F$y$","We present a detailed study of the electrical transport properties of a
+recently discovered iron-based superconductor:
+Sm$_4$Fe$_2$As$_2$Te$_{0.72}$O$_{2.8}$F$_{1.2}$. We followed the temperature
+dependence of the upper critical field by resistivity measurement of single
+crystals in magnetic fields up to 16 T, oriented along the two main
+crystallographic directions. This material exhibits a zero-temperature upper
+critical field of 90 T and 65 T parallel and perpendicular to the Fe$_2$As$_2$
+planes, respectively. An unprecedented superconducting magnetic anisotropy
+$\gamma_H=H_{c2}^{ab}/H_{c2}^c \sim 14$ is observed near Tc, and it decreases
+at lower temperatures as expected in multiband superconductors. Direct
+measurement of the electronic anisotropy was performed on microfabricated
+samples, showing a value of $\rho_c/\rho_{ab}(300K) \sim 5$ that raises up to
+19 near Tc. Finally, we have studied the pressure and temperature dependence of
+the in-plane resistivity. The critical temperature decreases linearly upon
+application of hydrostatic pressure (up to 2 GPa) similarly to overdoped
+cuprate superconductors. The resistivity shows saturation at high temperatures,
+suggesting that the material approaches the Mott-Ioffe-Regel limit for metallic
+conduction. Indeed, we have successfully modelled the resistivity in the normal
+state with a parallel resistor model that is widely accepted for this state.
+All the measured quantities suggest strong pressure dependence of the density
+of states.",1612.05792v1
+2016-12-20,Indirect Searches of the Degenerate MSSM,"A degenerate sfermionic particle spectrum can escape constraints from flavor
+physics, and at the same time evade the limits from the direct searches if the
+degeneracy extends to the gaugino-higgsino sector. Inspired by this, we
+consider a scenario where all the soft terms have an approximately common mass
+scale at $M_{\text{SUSY}}$, with splittings $\lesssim \mathcal{O}(10\%)$. As a
+result, the third generation sfermions have large to maximal (left-right)
+mixing, the same being the case with charginos and some sectors of the
+neutralino mass matrix. We study this scenario in the light of discovery of the
+Higgs boson with mass $\sim$ 125 GeV. We consider constraints from $B$-physics,
+the anomalous magnetic moment of the muon and the dark matter relic density. We
+find that a supersymmetric spectrum as light as 600 GeV could be consistent
+with all current data and also account for the observed anomalous magnetic
+moment of the muon within $2\sigma$. The neutralino relic density is generally
+too small to saturate the measured cold dark matter relic density. Direct
+detection limits from XENON100 and LUX put severe constraints on this scenario
+which will be conclusively probed by XENONnT experiment.",1612.06471v1
+2017-01-23,Crystal Growth and Magneto-transport of Bi2Se3 Single crystals,"In this letter, we report growth and characterization of bulk Bi2Se3 single
+crystals. The studied Bi2Se3 crystals are grown by self flux method through
+solid state reaction from high temperature (950C) melt of constituent elements
+and slow cooling (2C/hour). The resultant crystals are shiny and grown in [00l]
+direction, as evidenced from surface XRD. Detailed Reitveld analysis of PXRD
+(powder x-ray diffraction) of the crystals showed that these are crystallized
+in rhombohedral crystal structure with space group of R3m (D5) and the lattice
+parameters are a = 4.14(2)A, b = 4.14 (2) A and c = 28.7010(7) A. Temperature
+versus resistivity (R-T) plots revealed metallic conduction down to 2K, with
+typical room temperature resistivity (R300K) of around 0.53 mohm-cm and
+residual resistivity of 0.12 mohm-cm. Resistivity under magnetic field ]
+measurements exhibited large +Ve magneto resistance right from 2K to 200K.
+Isothermal magneto resistance [RH] measurements at 2K, 100K and 200K exhibited
+magneto resistance (MR) of up to 240, 130 and 60 percent respectively at 14
+Tesla. Further the MR plots are non saturating and linear with field at all
+temperature. At 2K the MR plots showed clear quantum oscillations at above say
+10 Tesla applied field. Also the Kohler plots i.e., were seen consolidating on
+one plot. Interestingly, the studied Bi2Se3 single crystal exhibited the
+Shubnikov-de Haas oscillations (SdH) at 2K under different applied magnetic
+fields ranging from 4Tesla to 14 Tesla",1701.06280v2
+2017-02-10,Mesoscopic transport in electrostatically-defined spin-full channels in quantum Hall ferromagnets,"In this work we use electrostatic control of quantum Hall ferromagnetic
+transitions in CdMnTe quantum wells to study electron transport through
+individual domain walls (DWs) induced at a specific location. These DWs are
+formed due to hybridization of two counter-propagating edge states with
+opposite spin polarization. Conduction through DWs is found to be symmetric
+under magnetic field direction reversal, consistent with the helical nature of
+these DWs. We observe that long domain walls are in the insulating regime with
+localization length 4 - 6~$\mu$m. In shorter DWs the resistance saturates to a
+non-zero value at low temperatures. Mesoscopic resistance fluctuations in a
+magnetic field are investigated. The theoretical model of transport through
+impurity states within the gap induced by spin-orbit interactions agrees well
+with the experimental data. Helical DWs have required symmetry for the
+formation of synthetic p-wave superconductors. Achieved electrostatic control
+of a single helical domain wall is a milestone on the path to their
+reconfigurable network and ultimately to a demonstration of braiding of
+non-Abelian excitations.",1702.03279v2
+2017-06-30,Dy doped BiFeO$_3$ : A Bulk Ceramic with Improved Multiferroic Properties Compared to Nano Counterparts,"The synthesis as well as structural, multiferroic and optical
+characterization of Dy doped BiFeO$_3$ multiferroic ceramic are presented. Bulk
+polycrystalline Bi$_{0.9}$Dy$_{0.1}$FeO$_3$ sample is synthesized by solid
+state reaction, while their nano counterparts are prepared using ultrasonic
+probe sonication technique. Significant improvement of phase purity in the as
+synthesized samples is observed after the doping of Dy both in bulk
+Bi$_{0.9}$Dy$_{0.1}$FeO$_3$ sample and corresponding nanoparticles as evidenced
+from Rietveld refinement. Magnetization measurements using SQUID magnetometer
+exhibit enhanced magnetic properties for Dy doped bulk
+Bi$_{0.9}$Dy$_{0.1}$FeO$_3$ ceramic compared to their nanostructured
+counterparts as well as undoped BiFeO$_3$. Within the applied field range,
+saturation polarization is observed for Bi$_{0.9}$Dy$_{0.1}$FeO$_3$ bulk
+ceramic only. As a result, intrinsic ferroelectric behavior is obtained just
+for this sample. Optical bandgap measurements reveal lower bandgap for Dy doped
+bulk Bi$_{0.9}$Dy$_{0.1}$FeO$_3$ ceramic compared to that of corresponding
+nanoparticles and undoped BiFeO$_3$. The outcome of this investigation
+demonstrates the potential of Dy as a doping element in BiFeO$_3$ that provides
+a bulk ceramic material with improved multiferroic and optical properties
+compared to those of corresponding nanoparticles which involve rigorous
+synthesis procedure.",1706.10226v1
+2017-07-07,Solar plasma radio emission in the presence of imbalanced turbulence of kinetic-scale Alfvén waves,"We study the influence of kinetic-scale Alfv\'enic turbulence on the
+generation of plasma radio emission in the solar coronal regions where the
+plasma/magnetic pressure ratio $\beta $ is smaller than the electron/ion mass
+ratio $m_{e}/m_{i}$. The present study is motivated by the phenomenon of solar
+type I radio storms associated with the strong magnetic field of active
+regions. The measured brightness temperature of the type I storms can be up to
+$10^{10}$ K for continuum emission, and can exceed $10^{11}$ K for type I
+bursts. At present, there is no generally accepted theory explaining such high
+brightness temperatures and some other properties of the type I storms. We
+propose the model with the imbalanced turbulence of kinetic-scale Alfv\'en
+waves producing an asymmetric quasilinear plateau on the upward half of the
+electron velocity distribution. The Landau damping of resonant Langmuir waves
+is suppressed and their amplitudes grow spontaneously above the thermal level.
+The estimated saturation level of Langmuir waves is high enough to generate
+observed type I radio emission at the fundamental plasma frequency. Harmonic
+emission does not appear in our model because the backward-propagating Langmuir
+waves undergo a strong Landau damping. Our model predicts $100\%$ polarization
+in the sense of the ordinary (o-) mode of type I emission.",1707.02295v1
+2017-07-27,Electron spin resonance for the detection of long-range spin nematic order,"In this paper we propose that electron spin resonance (ESR) measurements
+enable us to detect the long-range spin nematic order. We show that the
+frequency of the paramagnetic resonance peak in the ESR spectrum is shifted by
+the ferroquadrupolar order parameter together with other quantities. The
+ferroquadrupolar order parameter is extractable from the angular dependence of
+the frequency shift. In contrast, the antiferroquadrupolar order parameter is
+usually invisible in the frequency shift. Instead, the long-range
+antiferroquadrupolar order yields a characteristic resonance peak in the ESR
+spectrum, which we call a magnon-pair resonance peak. This resonance
+corresponds to the excitation of the bound magnon pair at the wave vector $\bm
+k={\bm 0}$. Reflecting the condensation of bound magnon pairs, the field
+dependence of the magnon-pair resonance frequency shows a singular upturn at
+the saturation field. Moreover, the intensity of the magnon-pair resonance peak
+shows a characteristic angular dependence and it vanishes when the magnetic
+field is parallel to one of the axes that diagonalize the weak anisotropic
+interactions. We confirm these general properties of the magnon-pair resonance
+peak in the spin nematic phase by studying an $S=1$ bilinear-biquadratic model
+on the square lattice in the linear flavor-wave approximation. In addition, we
+argue applications to the $S=1/2$ frustrated ferromagnets and also the $S=1/2$
+orthogonal dimer spin system SrCu$_2$(BO$_3$)$_2$, both of which are candidate
+materials of spin nematics. Our theory for the antiferroquadrupolar ordered
+phase is consistent with many features of the magnon-pair resonance peak
+experimentally observed in the low-magnetization regime of
+SrCu$_2$(BO$_3$)$_2$.",1707.08784v2
+2017-08-16,"Role of pinning mechanism in co-precipitation derived cobalt rich, cobalt ferrite nanoparticles","Cobalt ferrite nanoparticles have been synthesized using a co-precipitation
+approach. Co:Fe precursor ratio is varied over a certain window (1.05 to 1.2).
+It is observed that the 1.15:2 precursor ratio gives better phase control but
+poor coercivity. On the other hand, 1.05:2 precursor ratio results in
+substantially better coercivity values (274kA/m; almost 300% the value reported
+for co-precipitated cobalt ferrite by Praveena et al.), but moderate BH product
+maximum (2.25 kJ/m3; ~ comparable to many reports on cobalt ferrite
+nanoparticles so far). The nanoparticles with best coercivity are annealed at
+873K for varying durations (2, 4, 6, 12 hrs). It is observed that the
+coercivity drops drastically (almost by 80%) after annealing for 2 hours.
+However thereafter coercivity and saturation magnetization improves marginally
+with increasing duration of annealing. These studies, along with
+thermogravimetric analysis, and infrared spectroscopic results indicate that a
+hydroxide nanophase based flux pinning mechanism at the grain boundary plays an
+important role in explaining the observed magnetic property trends. It is
+believed that this result will be generically helpful in developing soft
+chemically derived ferrites with higher coercivity and moderate (BH)max.
+However to develop plausible applications using the reported ferrites that use
+nanophase flux pinning, soft materials and device processing methods will need
+to be explored.",1708.04839v1
+2017-09-04,Extended Phase Graph formalism for systems with Magnetization Transfer and Chemical Exchange,"An Extended Phase Graph framework for modelling systems with exchange or
+magnetization transfer (MT) is proposed. The framework, referred to as EPG-X,
+models coupled two-compartment systems by describing each compartment with
+separate phase graphs that exchange during evolution periods. There are two
+variants: EPG-X(BM) for systems governed by the Bloch-McConnell equations; and
+EPG-X(MT) for the pulsed MT formalism. For the MT case the ""bound"" protons have
+no transverse components so their phase graph consists only longitudinal
+states. EPG-X was used to model steady-state gradient echo imaging, MT effects
+in multislice Turbo Spin Echo imaging, multiecho CPMG for multicomponent T2
+relaxometry and transient variable flip angle gradient echo imaging of the type
+used for MR Fingerprinting. Experimental data were also collected for the final
+case. Steady-state predictions from EPG-X closely match directly derived
+steady-state solutions which differ substantially from classic ""single pool""
+EPG predictions. EPG-X(MT) predicts similar MT related levels of signal
+attenuation in white matter as have been reported elsewhere in the literature.
+Modelling of CPMG echo trains with EPG-X(BM) suggests that exchange processes
+can lead to an underestimate of the fraction of short T2 species. Modelling of
+transient gradient echo sequences with EPG-X(MT) suggests that measurable MT
+effects result from variable saturation of bound protons, particularly after
+inversion pulses. In conclusion, EPG-X can be used for modelling of the
+transient signal response of systems exhibiting chemical exchange or MT. This
+may be particularly beneficial for relaxometry approaches that rely on
+characterising transient rather than steady-state sequences.",1709.00832v1
+2017-09-30,Dimensional crossover and incipient quantum size effects in superconducting niobium nanofilms,"Superconducting and normal state properties of sputtered Niobium nanofilms
+have been systematically investigated, as a function of film thickness in a
+d=9-90 nm range, on different substrates. The width of the
+superconducting-to-normal transition for all films remained in few tens of mK,
+thus remarkably narrow, confirming their high quality. We found that the
+superconducting critical current density exhibits a pronounced maximum, three
+times larger than its bulk value, for film thickness around 25 nm, marking the
+3D-to-2D crossover. The extracted magnetic penetration depth shows a sizeable
+enhancement for the thinnest films, aside the usual demagnetization effects.
+Additional amplification effects of the superconducting properties have been
+obtained in the case of sapphire substrates or squeezing the lateral size of
+the nanofilms. For thickness close to 20 nm we also measured a doubled
+perpendicular critical magnetic field compared to its saturation value for d>33
+nm, indicating shortening of the correlation length and the formation of small
+Cooper pairs in the condensate. Our data analysis evidences an exciting
+interplay between quantum-size and proximity effects together with
+strong-coupling effects and importance of disorder in the thinnest films,
+locating the ones with optimally enhanced critical properties close to the
+BCS-BEC crossover regime.",1710.00265v1
+2017-10-06,3d Transition Metals and Oxides within Carbon Nanotubes by Co-Pyrolysis of Metallocene & Camphor: High Filling Efficiency and Self-Organized Structures,"We demonstrate that a single zone furnace with a modified synthesis chamber
+design is sufficient to obtain metal (Fe, Co or Ni) filled carbon nanotubes
+(CNT) with high filling efficiency and controlled morphology. Samples are
+formed by pyrolysis of metallocenes, a synthesis technique that otherwise
+requires a dual zone furnace. Respective metallocene in all three cases are
+sublimed in powder form, a crucial factor for obtaining high filling
+efficiency. While Fe@CNT is routinely produced using this technique,
+well-formed Ni@CNT or Co@CNT samples are reported for the first time. This is
+achieved by sublimation of nickelocene (or cobaltocene) in combination with
+'camphor'. These samples exhibit some of the highest saturation magnetization
+(Ms) values, at least an order of magnitude higher than that reported for Ni or
+Co filled CNT, by aerosol assisted pyrolysis. The results also elucidate on why
+Ni or Co@CNT are relatively difficult to obtain by pyrolyzing powder
+metallocene alone. Overall, a systematic variation of synthesis parameters
+provides insights for obtaining narrow length and diameter distribution and
+reduced residue particles outside filled CNT - factors which are important for
+device related applications. Finally, the utility of this technique is
+demonstrated by obtaining highly aligned forest of Fe2O3@CNT, wherein Fe2O3 is
+a functional magnetic oxide relevant to spintronics and battery applications.",1710.02413v1
+2017-12-24,The screening effects on field enhancement factor of zigzag graphene nanoribbon arrays: A first-principles study,"The field screening effect on the electronic and field-emission properties of
+zigzag graphene nanoribbons (ZGNRs) has been studied using first-principles
+calculations. We have systematically investigated the effect of inter-ribbon
+distance and ribbon width on the work function, field enhancement factor, band
+gap and edge magnetism of zigzag graphene nanoribbons (ZGNRs). It is found that
+the work function of ZGNRs increases rapidly as the inter-ribbon distance Dx
+increases, which is caused by the positive dipole at the edge of the ribbon.
+For a given Dx, the work function of ZGNRs decreases as the ribbon width W
+increases. The wider the width of ribbon, the stronger the effect of
+inter-ribbon distance on the work function. Using a simple linear interpolation
+model, we can obtain the work function of ZGNR of any ribbon-width. For the
+case of Dx < W, the field enhancement factor increases rapidly as the
+inter-ribbon distance increases. As we further increase Dx, the enhancement
+factor increases slowly and then tends toward saturation. The inter-ribbon
+distance of ZGNRs can modulate the magnitude of the band gap and edge
+magnetism. These observations above can all be explained by the screening
+effect.",1712.08935v1
+2018-02-02,Full- & Reduced-Order State-Space Modeling of Wind Turbine Systems with Permanent-Magnet Synchronous Generator,"Wind energy is an integral part of nowadays energy supply and one of the
+fastest growing sources of electricity in the world today. Accurate models for
+wind energy conversion systems (WECSs) are of key interest for the analysis and
+control design of present and future energy systems. Existing control-oriented
+WECSs models are subject to unstructured simplifications, which have not been
+discussed in literature so far. Thus, this technical note presents are thorough
+derivation of a physical state-space model for permanent magnet synchronous
+generator WECSs. The physical model considers all dynamic effects that
+significantly influence the system's power output, including the switching of
+the power electronics. Alternatively, the model is formulated in the $(a,b,c)$-
+and $(d,q)$-reference frame. Secondly, a complete control and operation
+management system for the wind regimes II and III and the transition between
+the regimes is presented. The control takes practical effects such as input
+saturation and integral windup into account. Thirdly, by a structured model
+reduction procedure, two state-space models of WECS with reduced complexity are
+derived: a non-switching model and a non-switching reduced-order model. The
+validity of the models is illustrated and compared through a numerical
+simulation study.",1802.00799v1
+2018-03-23,Dissipative structures in magnetorotational turbulence,"Via the process of accretion, magnetorotational turbulence removes energy
+from a disk's orbital motion and transforms it into heat. Turbulent heating is
+far from uniform and is usually concentrated in small regions of intense
+dissipation, characterised by abrupt magnetic reconnection and higher
+temperatures. These regions are of interest because they might generate
+non-thermal emission, in the form of flares and energetic particles, or
+thermally process solids in protoplanetary disks. Moreover, the nature of the
+dissipation bears on the fundamental dynamics of the magnetorotational
+instability (MRI) itself: local simulations indicate that the large-scale
+properties of the turbulence (e.g. saturation levels, the stress-pressure
+relationship) depend on the short dissipative scales. In this paper we
+undertake a numerical study of how the MRI dissipates and the small-scale
+dissipative structures it employs to do so. We use the Godunov code RAMSES and
+unstratified compressible shearing boxes. Our simulations reveal that
+dissipation is concentrated in ribbons of strong magnetic reconnection that are
+significantly elongated in azimuth, up to a scale height. Dissipative
+structures are hence meso-scale objects, and potentially provide a route by
+which large scales and small scales interact. We go on to show how these
+ribbons evolve over time --- forming, merging, breaking apart, and
+disappearing. Finally, we reveal important couplings between the large-scale
+density waves generated by the MRI and the small-scale structures, which may
+illuminate the stress-pressure relationship in MRI turbulence.",1803.08757v1
+2018-04-13,Tuning Spin Dynamics and Localization Near the Metal-Insulator Transition in Fe/GaAs heterostructures,"We present a simultaneous investigation of coherent spin dynamics in both
+localized and itinerant carriers in Fe/GaAs heterostructures using ultrafast
+and spin-resolved pump-probe spectroscopy. We find that for excitation
+densities that push the transient Fermi energy of photocarriers above the
+mobility edge there exist two distinct precession frequencies in the ob-served
+spin dynamics, allowing us to simultaneously monitor both localized and
+itinerant states. For low magnetic fields (below 3 T) the beat frequency
+between these two excitations evolves linearly, indicating that the nuclear
+polarization is saturated almost immediately and that the hyperfine coupling to
+these two states is comparable, despite the 100x enhancement in nuclear
+polarization provided by the presence of the Fe layer. At higher magnetic
+fields (above 3 T) the Zeeman energy drives reentrant localization of the
+photocarriers. Subtracting the constant hyperfine contribution from both sets
+of data allows us to extract the Lande g-factor for each state and estimate
+their energy relative to the bottom of the conduction band, yielding -2.16 meV
+and 17 meV for localized and itinerant states, respectively. This work advances
+our fundamental understanding of spin-spin interactions between electron and
+nuclear spin species, as well as between localized and itinerant electronics
+states, and therefore has implications for future work in both spintronics and
+quantum information/computation.",1804.04761v1
+2018-06-11,Electric-field quenching of optically detected magnetic resonance in a $π$-conjugated polymer,"Electric fields are central to the operation of optoelectronic devices based
+on conjugated polymers since they drive the recombination of electrons and
+holes to excitons in organic light-emitting diodes but are also responsible for
+the dissociation of excitons in solar cells. One way to track the microscopic
+effect of electric fields on charge carriers formed under illumination of a
+polymer film is to exploit the fluorescence arising from delayed recombination
+of carrier pairs, a process which is fundamentally spin dependent. Such
+spin-dependent recombination can be probed directly in fluorescence, by
+optically detected magnetic resonance (ODMR). Depending on the relative
+orientation, an electric field may either dissociate or stabilize an
+electron-hole carrier pair. We find that the ODMR signal in a polymer film is
+quenched in an electric field, but that, at fields exceeding 1 MV/cm, this
+quenching saturates. This finding contrasts the complete ODMR suppression that
+was previously observed in polymeric photodiodes, indicating that
+exciton-charge interactions---analogous to Auger recombination in crystalline
+semiconductors---may constitute the dominant carrier-pair dissociation process
+in organic electronics.",1806.03805v1
+2018-09-24,Simulations of radiative turbulent mixing layers,"Radiative turbulent mixing layers should be ubiquitous in multi-phase gas
+with shear flow. They are a potentially attractive explanation for the high
+ions such as OVI seen in high velocity clouds and the circumgalactic medium
+(CGM) of galaxies. We perform 3D MHD simulations with non-equilibrium (NEI) and
+photoionization modeling, with an eye towards testing simple analytic models.
+Even purely hydrodynamic collisional ionization equilibrium (CIE) calculations
+have column densities much lower than observations. Characteristic inflow and
+turbulent velocities are much less than the shear velocity, and the layer width
+$h \propto t_\mathrm{cool}^{1/2}$ rather than $h \propto t_\mathrm{cool}$.
+Column densities are not independent of density or metallicity as analytic
+scalings predict, and show surprisingly weak dependence on shear velocity and
+density contrast. Radiative cooling, rather than Kelvin-Helmholtz instability,
+appears paramount in determining the saturated state. Low pressure due to fast
+cooling both seeds turbulence and sets the entrainment rate of hot gas, whose
+enthalpy flux, along with turbulent dissipation, energizes the layer.
+Regardless of initial geometry, magnetic fields are amplified and stabilize the
+mixing layer via magnetic tension, producing almost laminar flow and depressing
+column densities. NEI effects can boost column densities by factors of a few.
+Suppression of cooling by NEI or photoionization can in principle also increase
+OVI column densities, but in practice is unimportant for CGM conditions. To
+explain observations, sightlines must pierce hundreds or thousands of mixing
+layers, which may be plausible if the CGM exists as a `fog' of tiny cloudlets.",1809.09101v2
+2018-09-24,"The failure of stellar feedback, magnetic fields, conduction, and morphological quenching in maintaining red galaxies","The quenching ""maintenance'"" and related ""cooling flow"" problems are
+important in galaxies from Milky Way mass through clusters. We investigate this
+in halos with masses $\sim 10^{12}-10^{14}\,{\rm M}_{\odot}$, using
+non-cosmological high-resolution hydrodynamic simulations with the FIRE-2
+(Feedback In Realistic Environments) stellar feedback model. We specifically
+focus on physics present without AGN, and show that various proposed ""non-AGN""
+solution mechanisms in the literature, including Type Ia supernovae, shocked
+AGB winds, other forms of stellar feedback (e.g. cosmic rays), magnetic fields,
+Spitzer-Braginskii conduction, or ""morphological quenching"" do not halt or
+substantially reduce cooling flows nor maintain ""quenched"" galaxies in this
+mass range. We show that stellar feedback (including cosmic rays from SNe)
+alters the balance of cold/warm gas and the rate at which the cooled gas within
+the galaxy turns into stars, but not the net baryonic inflow. If anything,
+outflowing metals and dense gas promote additional cooling. Conduction is
+important only in the most massive halos, as expected, but even at $\sim
+10^{14}\,{\rm M}_{\odot}$ reduces inflow only by a factor $\sim 2$ (owing to
+saturation effects and anisotropic suppression). Changing the morphology of the
+galaxies only slightly alters their Toomre-$Q$ parameter, and has no effect on
+cooling (as expected), so has essentially no effect on cooling flows or
+maintaining quenching. This all supports the idea that additional physics,
+e.g., AGN feedback, must be important in massive galaxies.",1809.09120v1
+2018-10-21,String orders in the Luttinger liquid phase of one-dimensional spin-1/2 systems,"Luttinger liquid (LL) phase refers to a quantum phase which emerges in the
+ground state phase diagram of quite often low-dimensional quantum magnets as
+spin-1/2 XX, XYY and frustrated chains. It is believed that the quasi
+long-range order exists between particles forming the system in the LL phase.
+Here, at the first step we concentrate on the study of correlated spin
+particles in the one-dimensional (1D) spin-1/2 XX model which is exactly
+solvable. We show that the spin-1/2 particles form string orders with an even
+number of spins in the LL phase of the 1D spin-1/2 XX model. As soon as the
+transverse magnetic field is applied to the system, string orders with an odd
+number of spins induce in the LL phase. All ordered strings of spin-1/2
+particles will be destroyed at the quantum critical transverse field, $h_c$. No
+strings exist in the saturated ferromagnetic phase. At the second step we focus
+on the LL phase in the ground state phase diagram of the 1D spin-1/2 XYY and
+frustrated ferromagnetic models. We show that the even-string orders exist in
+the LL phase of the 1D spin-1/2 XYY model but in the LL phase of the 1D
+spin-1/2 frustrated ferromagnetic model we found all kind of strings. In
+addition, the existence of a clear relation between the long-distance
+entanglement and string orders in the LL phase is shown. Also, the effect of
+the thermal fluctuations on the behavior of the string orders is studied.",1810.08903v1
+2018-11-05,"Avoiding the $H_c=0$ anomaly using FORC+ (expanded version of paper GG-05, MMM-Intermag 2019)","In conventional FORC (First Order Reversal Curve) analysis of a magnetic
+system, reversible and low-coercivity irreversible materials are treated as
+being qualitatively different: the FORC distribution shows low-coercivity
+materials but completely hides reversible (zero-coercivity) ones. This
+distinction is artificial -- as the coercivity approaches zero, the physical
+properties of an irreversible material change smoothly into those of a
+reversible material. We have developed a method (called FORC+, implemented in
+free software at http://MagVis.org) for displaying the reversible properties of
+a system (a reversible switching-field distribution, R-SFD) together with the
+irreversible ones (the usual FORC distribution), so that there is no sudden
+discontinuity in the display when the coercivity becomes zero. We will define a
+""FORC+ dataset"" to include the usual FORC distribution, the R-SFD, the
+saturation magnetization, and what we will call the ""lost hysteron
+distribution"" (LHD) such that no information is lost -- the original FORC
+curves can be exactly recovered from the FORC+ dataset. We also give some
+examples of the application of FORC+ to real data -- it uses a novel
+complementary-color display that minimizes the need for smoothing. In systems
+which switch suddenly (thus having sharp structures in the FORC distribution)
+direct display of un-smoothed raw data allows visualization of sharp structures
+that would be washed out in a conventional smoothed FORC display. This is an
+expanded version of paper GG-05, MMM-Intermag 2019, with a discrete derivation
+of the FORC distribution (Eq. 1) and an additional example (Fig. 7).",1811.02080v1
+2018-11-21,The Rotationally Modulated Polarization of $ξ$ Boo A,"We have observed the active star $\xi$ Boo A (HD 131156A) with high precision
+broadband linear polarimetry contemporaneously with circular
+spectropolarimetry. We find both signals are modulated by the 6.43 day rotation
+period of $\xi$ Boo A. The signals from the two techniques are 0.25 out of
+phase, consistent with the broadband linear polarization resulting from
+differential saturation of spectral lines in the global transverse magnetic
+field. The mean magnitude of the linear polarization signal is ~4 ppm/G but its
+structure is complex and the amplitude of the variations suppressed relative to
+the longitudinal magnetic field. The result has important implications for
+current attempts to detect polarized light from hot Jupiters orbiting active
+stars in the combined light of the star and planet. In such work stellar
+activity will manifest as noise, both on the time scale of stellar rotation,
+and on longer time scales - where changes in activity level will manifest as a
+baseline shift between observing runs.",1811.08534v2
+2018-12-16,Magnetic field effects on one-dimensional Anderson localization of light,"Transport of coherent waves in multiple-scattering media may exhibit
+fundamental, non intuitive phenomena such as halt of diffusion by disorder
+called Anderson localization. For electromagnetic waves, this phenomenon was
+observed only in one and two dimensions so far. However, none of these
+experiments studied the contribution of reciprocal paths nor their manipulation
+by external fields. In order to weaken the effect of reciprocity of coherent
+wave transport on Anderson localization in one dimension (1D), we studied light
+propagation through stacks of parallel Faraday-active glass slides exposed to
+magnetic fields up to 18 Tesla. Measurements of light transmission statistics
+are presented and compared to 1D transfer-matrix simulations. The latter
+reveals a self-organization of the polarization states in this system leading
+to a saturation of the Faraday rotation-induced reciprocity breaking, an
+increase of the localization length, and a decrease of transmission
+fluctuations when reciprocity is broken. This is confirmed experimentally for
+samples containing small numbers of slides while for larger samples a crossover
+from a 1D to a quasi-1D transport regime is found.",1812.06447v3
+2019-01-03,Self-dual solitons in a generalized Chern-Simons baby Skyrme model,"We have shown the existence of self-dual solitons in a type of generalized
+Chern-Simons baby Skyrme model where the generalized function (depending only
+in the Skyrme field) is coupled to the sigma-model term. The consistent
+implementation of the Bogomol'nyi-Prasad-Sommerfield (BPS) formalism requires
+the generalizing function becomes the superpotential defining properly the
+self-dual potential. Thus, we have obtained a topological energy lower-bound
+(Bogomol'nyi bound) and the self-dual equations satisfied by the fields
+saturating such a bound. The Bogomol'nyi bound being proportional to the
+topological charge of the Skyrme field is quantized whereas the total magnetic
+flux is not. Such as expected in a Chern-Simons model the total magnetic flux
+and the total electrical charge are proportional to each other. Thus, by
+considering the superpotential a well-behaved function in the whole target
+space we have shown the existence of three types of self-dual solutions:
+compacton solitons, soliton solutions whose tail decays following an
+exponential-law $e^{-\alpha r^{2}}$ ($\alpha>0$), and solitons having a
+power-law decay $r^{-\beta}$ ($\beta>0$). The profiles of the two last solitons
+can exhibit a compactonlike behavior. The self-dual equations have been solved
+numerically and we have depicted the soliton profiles, commenting on the main
+characteristics exhibited by them.",1901.00655v2
+2019-01-21,Dust Polarization Maps from TIGRESS: E/B power asymmetry and TE correlation,"We present the first large set of all-sky synthetic dust polarization maps
+derived directly from a self-consistent magnetohydrodynamics simulation using
+the TIGRESS framework. Turbulence in this simulation is predominantly driven by
+supernova explosions, with rates that are self-consistently regulated by
+feedback loops. The simulation covers both the outer scale and inertial range
+of turbulence with uniformly high resolution. The shearing-box utilized in the
+simulation in concert with resolved supernova-driven turbulence enables to
+capture the generation, growth, and saturation of both turbulent and mean
+magnetic fields. We construct polarization maps at 353 GHz as seen by observers
+inside a model of the multiphase, turbulent, magnetized interstellar medium
+(ISM). To fully sample the simulated ISM state, we use 350 snapshots spanning
+over ~350Myr (more than six feedback loops) and nine representative observers.
+The synthetic skies show a prevalent E/B power asymmetry (EE>BB) and positive
+TE correlation in broad agreement with observations by the Planck satellite.
+However, the ranges of EE/BB~1.4-1.7 and TE/(TT*EE)^{1/2}~0.2-0.3 are generally
+lower. We find large fluctuations of E/B asymmetry and TE correlation depending
+on the observer's position, and temporal fluctuations of interstellar medium
+properties due to bursts of star formation. The synthetic maps are made
+publicly available to provide novel models of the microwave sky.",1901.07079v2
+2019-03-05,Cubic symmetry and magnetic frustration on the $fcc$ spin lattice in K$_2$IrCl$_6$,"Cubic crystal structure and regular octahedral environment of Ir$^{4+}$
+render antifluorite-type K$_2$IrCl$_6$ a model fcc antiferromagnet with a
+combination of Heisenberg and Kitaev exchange interactions. High-resolution
+synchrotron powder diffraction confirms cubic symmetry down to at least 20 K,
+with a low-energy rotary mode gradually suppressed upon cooling. Using
+thermodynamic and transport measurements, we estimate the activation energy of
+$\Delta\simeq 0.7$ eV for charge transport, the antiferromagnetic Curie-Weiss
+temperature of $\theta_{\rm CW}\simeq -43$ K, and the extrapolated saturation
+field of $H_s\simeq 87$ T. All these parameters are well reproduced \textit{ab
+initio} using $U_{\rm eff}=2.2$ eV as the effective Coulomb repulsion
+parameter. The antiferromagnetic Kitaev exchange term of $K\simeq 5$ K is about
+one half of the Heisenberg term $J\simeq 13$ K. While this combination removes
+a large part of the classical ground-state degeneracy, the selection of the
+unique magnetic ground state additionally requires a weak second-neighbor
+exchange coupling $J_2\simeq 0.2$ K. Our results suggest that K$_2$IrCl$_6$ may
+offer the best possible cubic conditions for Ir$^{4+}$ and demonstrates the
+interplay of geometrical and exchange frustration in a high-symmetry setting.",1903.01660v2
+2019-03-22,Effects of post-deposition annealing on the structure and magnetization of PLD grown Yttrium Iron Garnet films,"We report on the recrystallization of 200 nm thick as-grown Yttrium Iron
+Garnet (Y_3.4 Fe_4.6 O_12) films on (111) face of Gadolinium Gallium Garnet
+(GGG) single crystals by post-deposition annealing. Epitaxial conversion of the
+as-grown microcrystalline YIG films was seen after annealing at 800oC for more
+than 30 minutes both in ambient oxygen as well as in air. The as-grown oxygen
+annealed samples at 800oC for 60 minutes crystallize epitaxially and show
+excellent figure-of-merit for saturation magnetization (MS = 3.3 {\mu}B/f.u.,
+comparable to bulk value) and coercivity (HC ~ 1.1 Oe). The ambient air
+annealing at 800oC with a very slow rate of cooling (2oC/min) results in a
+double layer structure with a thicker unstrained epitaxial top layer having the
+MS and HC of 2.9 {\mu}B/f.u. and 0.12 Oe respectively. The symmetric and
+asymmetric Reciprocal space maps of both the samples reveal a locking of the
+in-plane lattice of the film to the in-plane lattice of substrate, indicating a
+pseudomorphic growth. The residual stress calculated by sin^2 {\psi} technique
+is compressive in nature. The lower layer in air annealed sample is highly
+strained, whereas, the top layer has negligible compressive stress.",1903.09457v1
+2019-03-19,Two-dimensional Magnetization-Transfer - CPMG MRI reveals tract- specific signatures in fixed rat spinal cord,"Multiexponential T2 (MET2) Relaxometry and Magnetization Transfer (MT) are
+among the most promising MRI-derived techniques for white matter (WM)
+characterization. Both techniques are shown to have histologically correlated
+sensitivity to myelin, but these correlations are not fully understood.
+Furthermore, MET2 and MT reports on different features of WM, thus being
+specific to different (patho)physiological states. Two-dimensional studies,
+such as those commonly used in NMR, have been rarely performed in this context.
+Here, off-resonance irradiation effects on MET2 components were evaluated in
+fixed rat spinal cord white matter at 16.4T. These 2D MT-MET2 experiments
+reveal that MT affects both short and long T2 in a tract-specific fashion. The
+spatially distinct modulations enhanced contrast between
+microstructurally-distinct spinal cord tracts. Two hypotheses to explain these
+findings were proposed: either selective elimination of a short T2 component
+through pre-saturation is combined with intercompartmental water exchange
+effects that occur on the timescale of irradiation; or other macromolecular
+species that exist within the tissue - other than myelin - such as
+neurofilaments, may be involved in the apparent microstructural segregation of
+the spinal cord (SC) from MET2. Though further investigation is required to
+elucidate the underlying mechanism, this phenomenon adds a new dimension for WM
+characterization.",1903.10376v1
+2019-04-10,Magnetohydrodynamics in a Cylindrical Shearing Box,"We develop a framework for magnetohydrodynamical (MHD) simulations in a local
+cylindrical shearing box by extending the formulation of the Cartesian shearing
+box. We construct shearing-periodic conditions at the radial boundaries of a
+simulation box from the conservation relations of the basic MHD equations,
+taking into account the explicit radial dependence of physical quantities. We
+demonstrate quasi-steady mass accretion, which cannot be handled by the
+standard Cartesian shearing box model, with an ideal MHD simulation in a
+vertically unstratified cylindrical shearing box up to 200 rotations. In this
+demonstrative run we set up (i) net vertical magnetic flux, (ii) a locally
+isothermal equation of state, and (iii) a sub-Keplerian equilibrium rotation,
+whereas the sound velocity and the initial Alfven velocity have the same radial
+dependence as that of the Keplerian velocity. Inward mass accretion is induced
+to balance with the outward angular momentum flux of the MHD turbulence
+triggered by the magnetorotational instability in a self-consistent manner. We
+discuss detailed physical properties of the saturated magnetic field, in
+comparison to the results of a Cartesian shearing box simulation.",1904.05032v3
+2019-08-20,"Peculiarities in pseudo-transitions of a mixed spin-$(1/2,1)$ Ising-Heisenberg double-tetrahedral chain in an external magnetic field","Recently, it has been rigorously verified that several one-dimensional (1D)
+spin models may exhibit a peculiar pseudo-transition accompanied with anomalous
+response of thermodynamic quantities in a close vicinity of pseudo-critical
+temperature. In the present work we will introduce and exactly solve a mixed
+spin-(1/2,1) Ising-Heisenberg double-tetrahedral chain in an external magnetic
+field as another particular example of 1D lattice-statistical model with
+short-range interactions that displays a pseudo-transition of this type. The
+investigated model exhibits at zero temperature three ferrimagnetic phases,
+three frustrated phases, and one saturated paramagnetic phase. The ground-state
+phase diagram involves five unusual interfaces (phase boundaries), at which the
+residual entropy per site equals to a larger entropy of one of two coexisting
+phases. Four such interfaces are between a non-degenerate ferrimagnetic phase
+and a macroscopically degenerate frustrated phase, while one interface is
+between two non-degenerate ferrimagnetic phases. Though thermal excitations
+typically destroy all fingerprints of zero-temperature phase transitions of 1D
+lattice-statistical models with short-range forces, the mixed spin-(1/2,1)
+Ising-Heisenberg double-tetrahedral chain is quite robust with respect to
+thermal excitations and it displays peculiar pseudo-transitions close to all
+five aforementioned interfaces.",1908.07286v2
+2019-10-06,Self-dual solitons in a Maxwell-Chern-Simons baby Skyrme model,"We have studied the existence de self-dual solitons in a gauged version of
+the baby Skyrme model in which the gauge field dynamics is governed by the
+Maxwell-Chern-Simons action. For such a purpose, we have developed a detailed
+implementation of the Bogomol'nyi-Prasad-Sommerfield formalism providing the
+self-dual equations whose solutions saturate the energy lower bound. Such a
+bound related to the topological charge of the Skyrme field becomes quantized
+whereas both the total magnetic flux and the total electrical charge are not.
+We have found two types of self-dual Skyrme field profiles: the first is
+described by a solution which decays following an exponential-law ($e^{-\alpha
+r^2}$, $\alpha>0$); the second is portrayed by a solution having a power-law
+decay ($r^{-\beta}$, $\beta>0$). On other hand, in both cases the asymptotic
+behavior of the gauge field is similar to the one presented in the context of
+the Abelian Higgs models describing Abrikosov-Nielsen-Olesen charged vortices.
+Other interesting feature we highlight is the localized magnetic flux
+inversion, a property does not observed in others gauged baby Skyrme models
+already studied in literature. Numerical results are presented for rotationally
+symmetrical field configurations by remarking some of its essential features.",1910.02362v1
+2019-10-18,A substantial increase of Curie temperature in a new type of diluted magnetic semiconductors via effects of chemical pressure,"Chemical pressure is an effective method to tune physical properties,
+particularly for diluted magnetic semiconductors (DMS) of which ferromagnetic
+ordering is mediated by charge carriers. Via substitution of smaller Ca for
+larger Sr, we introduce chemical pressure on (Sr,Na)(Cd,Mn)2As2 to fabricate a
+new DMS material (Ca,Na)(Cd,Mn)2As2. Carriers and spins are introduced by
+substitutions of (Ca,Na) and (Cd,Mn) respectively. The unit cell volume reduces
+by 6.2% after complete substitution of Ca for Sr, suggesting a subsistent
+chemical pressure. Importantly the local geometry of [Cd/MnAs4] tetrahedron is
+optimized via chemical compression that increases the Mn-As hybridization
+leading to enhanced ferromagnetic interactions. As a result, the maximum Curie
+temperature (TC) is increased by about 50% while the the maximum saturation
+moment increases by over 100% from (Sr,Na)(Cd,Mn)2As2 to (Ca,Na)(Cd,Mn)2As2.
+The chemical pressure estimated from the equation of state is equal to an
+external physical pressure of 3.6 GPa.",1910.08305v2
+2019-11-27,Data-Driven Recursive Least Squares Estimation for Model Predictive Current Control of Permanent Magnet Synchronous Motors,"The performance of model predictive controllers (MPC) strongly depends on the
+model quality. In the field of electric drive control, white-box (WB) modeling
+approaches derived from first-order physical principles are most common. This
+procedure typically does not cover parasitic effects and parameter deviations
+are frequent. These issues are particularly crucial in the domain of
+self-commissioning drives when a hand-tailored, accurate WB plant model is not
+available. In order to compensate for such modeling errors and, therefore, to
+improve the control performance during transients and steady-state, this paper
+proposes a data-driven, real-time capable recursive least squares (RLS)
+estimation method for the current control of a permanent magnet synchronous
+motor (PMSM). The effect of the flux linkage and voltage harmonics due to the
+winding scheme can also be taken into account. Moreover, a compensating scheme
+for the interlocking time of the inverter is proposed. The proposed
+identification algorithm is investigated using the well-known
+finite-control-set MPC (FCS-MPC) in the rotor-oriented coordinate system. The
+extensive experimental results show the superior performance of the presented
+scheme compared to a FCS-MPC-based on a state-of-the-art WB motor model using
+look-up tables for adressing (cross-)saturation.",1911.12065v1
+2019-12-02,The Magnetorotational Instability Prefers Three Dimensions,"The magnetorotational instability (MRI) occurs when a weak magnetic field
+destabilises a rotating, electrically conducting fluid with inwardly increasing
+angular velocity. The MRI is essential to astrophysical disk theory where the
+shear is typically Keplerian. Internal shear layers in stars may also be MRI
+unstable, and they take a wide range of profiles, including near-critical. We
+show that the fastest growing modes of an ideal magnetofluid are
+three-dimensional provided the shear rate, $S$, is near the two-dimensional
+onset value, $S_c$. For a Keplerian shear, three-dimensional modes are unstable
+above $S\approx0.10S_c$, and dominate the two-dimensional modes until
+$S\approx2.05S_{c}$. These three-dimensional modes dominate for shear profiles
+relevant to stars and at magnetic Prandtl numbers relevant to liquid-metal
+laboratory experiments. Significant numbers of rapidly growing
+three-dimensional modes remain well past $2.05S_{c}$. These finding are
+significant in three ways. First, weakly nonlinear theory suggests that the MRI
+saturates by pushing the shear rate to its critical value. This can happen for
+systems, like stars and laboratory experiments, that can rearrange their
+angular velocity profiles. Second, the non-normal character and large transient
+growth of MRI modes should be important whenever three-dimensionality exists.
+Finally, three-dimensional growth suggests direct dynamo action driven from the
+linear instability.",1912.00972v1
+2019-12-10,F+ Center Exchange Mechanism and Magneto Crystalline Anisotropy in Ni doped 3C-SiC,"We report the experimental evidence in support of room temperature
+ferromagnetism in Ni doped 3C-SiC. Curie temperature is found to be > 350 K.
+Temperature dependent Electron paramagnetic resonance (EPR) study reveals that
+the valence state of Ni is 2+ and its environmental symmetry. A clear shift in
+both XRD and Raman peak confirms the incorporation of Ni in the host lattice.
+The variation in number of vacancies $V_{\mathrm{Si}}$, $V_{\mathrm{C}}$ and
+the number of free electron due to doping is consistent with the change in
+magnetization of the system. A direct correlation of ferromagnetic order (FM)
+with F+ centers exchange mechanism is established. The temperature variation of
+the anisotropic constant was determined using Law of Approach to Saturation
+(LAS). It was found that effective magnetic anisotropic constant decreases with
+increase in temperature. The EPR line width of the annealed sample increases
+with decrease in temperature, whereas the integrated intensity decreases with
+decrease in temperature. This could be due to incomplete quenching of orbital
+angular momentum in Si$_{x}$Ni$_{1-x}$C. In addition to this, the orbital
+degeneracy of fast relaxing impurity such as Ni in the cubic crystal field is
+not completely removed. This results in the line width decrease with increase
+in temperature.",1912.05921v2
+2020-01-03,Synthesis and characterization of Zn doped Mn ferrites nanostructures,"Zn doped Mn ferrites nanoparticles were fabricated by using Co-precipitation.
+Variation in structure, magnetic and optical properties of MnZn ferrites has
+been discussed. First of all, samples were synthesized, annealed at different
+temperatures and then characterized. The as-synthesized and annealed samples
+were investigated by X-ray diffraction (XRD), Scanning electron microscopy
+(SEM), Energy Dispersive spectroscopy (EDX), Ultra Violet visible spectrometry
+(Uv-Vis spectrometry) and Vibrating sample magnetometer (VSM). The average
+crystallite size of MnZn ferrites nanoparticles determined from XRD were in the
+range of 42 to 60 nm. These nanoparticles possess normal spinel structure. The
+SEM images showed the physical shape of the samples, which showed that the as
+prepared samples are more agglomerated and having flake like shape rather than
+annealed at 700C while the samples have longitudinal or rod like shape on
+annealing at 700C. The coercivity (Hc), saturation magnetization (Ms), and
+remanence (Mr) of Nps were also calculated. The (Ms) value is increasing from
+26 to 65 emu/g, the coercivity (Hc) is varying from 13 to 193 Oe and remanence
+(Mr) has also showing increasing trend although very less, from 0.031 to 0.798
+emu/g which are a little part of their bulk counter parts. The band gap energy
+of the samples was showing decreasing trend as with the increase of particle
+size which is of the order of 3.5 to 2.9 eV.",2001.00741v1
+2020-03-03,Parabolic diamond scanning probes for single spin magnetic field imaging,"Enhancing the measurement signal from solid state quantum sensors such as the
+nitrogen-vacancy (NV) center in diamond is an important problem for sensing and
+imaging of condensed matter systems. Here we engineer diamond scanning probes
+with a truncated parabolic profile that optimizes the photonic signal from
+single embedded NV centers, forming a high-sensitivity probe for nanoscale
+magnetic field imaging. We develop a scalable fabrication procedure based on
+dry etching with a flowable oxide mask to reliably produce a controlled tip
+curvature. The resulting parabolic tip shape yields a median saturation count
+rate of 2.1 $\pm$ 0.2 MHz, the highest reported for single NVs in scanning
+probes to date. Furthermore, the structures operate across the full NV
+photoluminescence spectrum, emitting into a numerical aperture of 0.46 and the
+end-facet of the truncated tip, located near the focus of the parabola, allows
+for small NV-sample spacings and nanoscale imaging. We demonstrate the
+excellent properties of these diamond scanning probes by imaging ferromagnetic
+stripes with a spatial resolution better than 50 nm. Our results mark a 5-fold
+improvement in measurement signal over the state-of-the art in scanning-probe
+based NV sensors.",2003.01733v1
+2020-03-19,Common dynamo scaling in slowly rotating young and evolved stars,"One interpretation of the activity and magnetism of late-type stars is that
+these both intensify with decreasing Rossby number up to a saturation level,
+suggesting that stellar dynamos depend on both rotation and convective
+turbulence. Some studies have claimed, however, that rotation alone suffices to
+parametrise this scaling adequately. Here, we tackle the question of the
+relevance of turbulence to stellar dynamos by including evolved, post main
+sequence stars in the analysis of the rotation-activity relation. These stars
+rotate very slowly compared with main sequence stars, but exhibit similar
+activity levels. We show that the two evolutionary stages fall together in the
+rotation-activity diagram and form a single sequence in the unsaturated regime
+in relation only to Rossby numbers derived from stellar models, confirming
+earlier preliminary results that relied on a more simplistic parametrisation of
+the convective turnover time. This mirrors recent results of fully convective M
+dwarfs, which likewise fall on the same rotation-activity sequence as partially
+convective solar-type stars. Our results demonstrate that turbulence plays a
+crucial role in driving stellar dynamos and suggest that there is a common
+turbulence-related dynamo mechanism explaining the magnetic activity of all
+late-type stars.",2003.08997v1
+2020-03-22,Magnetohydrodynamic modelling of star-planet interaction and associated auroral radio emission,"We present calculations of auroral radio powers of magnetised hot Jupiters
+orbiting Sun-like stars, computed using global magnetohydrodynamic (MHD)
+modelling of the magnetospheric and ionospheric convection arising from the
+interaction between the magnetosphere and the stellar wind. Exoplanetary
+auroral radio powers are traditionally estimated using empirical or
+analytically-derived relations, such as the Radiometric Bode's Law (RBL), which
+relates radio power to the magnetic or kinetic energy dissipated in the stellar
+wind-planet interaction. Such methods risk an oversimplification of the
+magnetospheric electrodynamics giving rise to radio emission. As the next step
+toward a self-consistent picture, we model the stellar
+wind-magnetosphere-ionosphere coupling currents using a 3D MHD model. We
+compute electron-cyclotron maser instability-driven emission from the
+calculated ionospheric field-aligned current density. We show that the auroral
+radio power is highly sensitive to interplanetary magnetic field (IMF)
+strength, and that the emission is saturated for plausible hot Jupiter Pedersen
+conductances, indicating that radio power may be largely independent of
+ionospheric conductance. We estimate peak radio powers of $10^{14}$ W from a
+planet exposed to an IMF strength of $10^3$ nT, implying flux densities at a
+distance of 15 pc from Earth potentially detectable with current and future
+radio telescopes. We also find a relation between radio power and planetary
+orbital distance that is broadly consistent with results from previous analytic
+models of magnetosphere-ionosphere coupling at hot Jupiters, and indicates that
+the RBL likely overestimates the radio powers by up to two orders of magnitude
+in the hot Jupiter regime",2003.09991v1
+2020-04-22,Simultaneous Nodal Superconductivity and Time-Reversal Symmetry Breaking in the Noncentrosymmetric Superconductor CaPtAs,"By employing a series of experimental techniques, we provide clear evidence
+that CaPtAs represents a rare example of a noncentrosymmetric superconductor
+which simultaneously exhibits nodes in the superconducting gap and broken
+time-reversal symmetry (TRS) in its superconducting state (below $T_c$
+$\approx$ 1.5 K). Unlike in fully-gapped superconductors, the magnetic
+penetration depth $\lambda(T)$ does not saturate at low temperatures, but
+instead it shows a $T^2$-dependence, characteristic of gap nodes. Both the
+superfluid density and the electronic specific heat are best described by a
+two-gap model comprising of a nodeless gap and a gap with nodes, rather than by
+single-band models. At the same time, zero-field muon-spin spectra exhibit
+increased relaxation rates below the onset of superconductivity, implying that
+TRS is broken in the superconducting state of CaPtAs, hence indicating its
+unconventional nature. Our observations suggest CaPtAs to be a new remarkable
+material which links two apparently disparate classes, that of TRS-breaking
+correlated magnetic superconductors with nodal gaps and the weakly-correlated
+noncentrosymmetric superconductors with broken TRS, normally exhibiting only a
+fully-gapped behavior.",2004.10425v1
+2020-05-27,Thermodynamic behaviour of magnetocaloric quantities in spin-1/2 Ising square trilayer,"A spin-1/2, Ising trilayered ferrimagnetic system on square Bravais lattice
+is studied, employing Monte-Carlo simulation with the single spin-flip
+Metropolis algorithm. The bulk of such a system is formed by three layers, each
+of which is composed entirely either by A or B type of atoms, resulting in two
+distinct compositions: ABA and AAB and two different types of magnetic
+interactions: ferromagnetic between like atoms and antiferromagnetic between
+unlike atoms. For such systems, Inverse Absolute of Reduced Residual
+Magnetisation is the absolute value of the ratio of the extremum of the
+magnetisation in between compensation and critical points and the saturation
+magnetisation. Variation of relative interaction strengths in the Hamiltonian,
+for a range of values, leads to the shift of compensation point and critical
+point and changes in the magnitude of Inverse absolute of Reduced Residual
+magnetisation. Probable mathematical forms of dependences of the Inverse
+absolute of Reduced Residual magnetisation and temperature interval between the
+compensation and critical points on controlling parameters were proposed in the
+absence of applied magnetic field and have obtained phase diagrams for both
+types of configurations from these relations. This alternative description of
+the simulated systems may help technologists design magnetocaloric materials
+according to desired characteristics.",2005.13509v6
+2020-06-25,Dynamics of reversed shear Alfvén eigenmode and energetic particles during current ramp-up,"Hybrid MHD-gyrokinetic code simulations are used to investigate the dynamics
+of frequency sweeping reversed shear Alfv\'en eigenmode (RSAE) strongly driven
+by energetic particles (EPs) during plasma current ramp-up in a conventional
+tokamak configuration. A series of weakly reversed shear equilibria
+representing time slices of long timescale MHD equilibrium evolution is
+considered, where the self-consistent RSAE-EP resonant interactions on the
+short timescale are analyzed in detail. Both linear and nonlinear RSAE dynamics
+are shown to be subject to the non-perturbative effect of EPs by maximizing
+wave-EP power transfer. In linear stage, EPs induce evident mode structure and
+frequency shifts; meanwhile, RSAE saturates by radial decoupling with resonant
+EPs due to weak magnetic shear, and gives rise to global EP convective
+transport and non-adiabatic frequency chirping. The spatiotemporal scales of
+phase space wave-EP interactions are characterized by the perpendicular
+wavelength and wave-particle trapping time. The simulations provide insights
+into general as well as specific features of RSAE spectra and EP transport from
+experimental observations, and illustrate the fundamental physics of wave-EP
+resonant interaction with the interplay of magnetic geometry, plasma
+non-uniformity and non-perturbative EPs.",2006.14242v1
+2020-07-14,Can we trust MHD jump conditions for collisionless shocks?,"When applied to compute the density jump of a shock, the standard
+magnetohydrodynamic (MHD) formalism assumes, 1) that all the upstream material
+passes downstream, together with the momentum and energy it carries, and 2)
+that pressures are isotropic. In a collisionless shock, shock accelerated
+particles going back and forth around the front can invalid the first
+assumption. In addition, an external magnetic field can sustain stable pressure
+anisotropies, invaliding the second assumption. It is therefore unclear whether
+the density jump of a collisionless shock fulfils the MHD jump or not.
+  Here we try to clarify this issue. A literature review is conducted on 68
+articles dealing with Particle-In-Cell simulations of collisionless shocks. We
+analyze the factors triggering departure from the MHD density jump and quantify
+their influence on $\Delta_{RH}$, the relative departure from the
+Rankine-Hugoniot jump. For small departures we propose $\Delta_{RH} = +
+\mathcal{O}(10^{-1-3.7\kappa})t^\kappa - \sigma \mathcal{O}(1)$ where $t$ is
+the timescale of the simulation, $\sigma$ the magnetization parameter and
+$\kappa$ a constant of order unity. The first term stems from the energy
+leakage into accelerated particle. The second term stems from the downstream
+anisotropy triggered by the field (assuming an isotropic upstream). This
+relation allows to assess to which extent a collisionless shock fulfils the RH
+density jump.
+  In the strong field limit and for parallel shocks, the departure caused by
+the field saturates at a finite, negative, value. For perpendicular shocks, the
+departure goes to zero at small and high $\sigma$'s so that we find here a
+departure window. The results obtained have to be checked against full 3D
+simulations.",2007.06906v1
+2020-08-03,Wind-MRI interactions in local models of protoplanetary discs: I. Ohmic resistivity,"A magnetic disc wind is an important mechanism that may be responsible for
+driving accretion and structure formation in protoplanetary discs. Recent
+numerical simulations have shown that these winds can take either the
+traditional `hourglass' symmetry about the mid-plane, or a `slanted' symmetry
+dominated by a mid-plane toroidal field of a single sign. The formation of this
+slanted symmetry state has not previously been explained. We use radially local
+1D vertical shearing box simulations to assess the importance of large-scale
+MRI channel modes in influencing the formation and morphologies of these wind
+solutions. We consider only Ohmic resistivity and explore the effect of
+different magnetisations, with the mid-plane $\beta$ parameter ranging from
+$10^5$ to $10^2$. We find that our magnetic winds go through three stages of
+development: cyclic, transitive and steady, with the steady wind taking a
+slanted symmetry profile similar to those observed in local and global
+simulations. We show that the cycles are driven by periodic excitation of the
+$n=2$ or $3$ MRI channel mode coupled with advective eviction, and that the
+transition to the steady wind is caused by a much more slowly growing $n=1$
+mode altering the wind structure. Saturation is achieved through a combination
+of advective damping from the strong wind, and suppression of the instability
+due to a strong toroidal field. A higher disc magnetisation leads to a greater
+tendency towards, and more rapid settling into the slanted symmetry steady
+wind, which may have important implications for mass and flux transport
+processes in protoplanetary discs.",2008.00906v1
+2020-10-08,The effects of rotation on the lithium depletion of G- and K-dwarfs in Messier 35,"New fibre spectroscopy and radial velocities from the WIYN telescope are used
+to measure photospheric lithium in 242 high-probability, zero-age-main-sequence
+(ZAMS) F- to K-type members of the rich cluster M35. Combining these with
+published rotation periods, the connection between lithium depletion and
+rotation is studied in unprecedented detail. At $T_{\rm eff}<5500$ K there is a
+strong relationship between faster rotation and less Li depletion, although
+with a dispersion larger than measurement uncertainties. Components of
+photometrically identified binary systems follow the same relationship. A
+correlation is also established between faster rotation rate (or smaller Rossby
+number), decreased Li depletion and larger stellar radius at a given $T_{\rm
+eff}$. These results support models where starspots and interior magnetic
+fields lead to inflated radii and reduced Li depletion during the pre main
+sequence (PMS) phase for the fastest rotators. However, the data are also
+consistent with the idea that all stars suffered lower levels of Li depletion
+than predicted by standard PMS models, perhaps because of deficiencies in those
+models or because saturated levels of magnetic activity suppress Li depletion
+equally in PMS stars of similar $T_{\rm eff}$ regardless of rotation rate, and
+that slower rotators subsequently experience more mixing and post-PMS Li
+depletion.",2010.04217v1
+2020-12-05,Levy noise-induced self-induced stochastic resonance in a memristive neuron,"Self-induced stochastic resonance (SISR) is a subtle resonance mechanism
+requiring a nontrivial scaling limit between the stochastic and the
+deterministic timescales of an excitable system, leading to the emergence of a
+limit cycle behavior which is absent without noise. All previous studies on
+SISR in neural systems have only considered the idealized Gaussian white noise.
+Moreover, these studies have ignored one electrophysiological aspect of the
+nerve cell: its memristive properties. In this paper, first, we show that in
+the excitable regime, the asymptotic matching of the Levy timescale (that
+follows a power law, unlike Gaussian noise that follows Kramers law) and the
+deterministic timescale (controlled by the singular parameter) can also induce
+a strong SISR. In addition, it is shown that the degree of SISR induced by Levy
+noise is not always higher than that of Gaussian noise. Second, we show that,
+for both types of noises, the two memristive properties of the neuron have
+opposite effects on the degree of SISR: the stronger the feedback gain
+parameter that controls the modulation of the membrane potential with the
+magnetic flux and the weaker the feedback gain parameter that controls the
+saturation of the magnetic flux, the higher the degree of SISR. Finally, we
+show that, for both types of noises, the degree of SISR in the memristive
+neuron is always higher than in the non-memristive neuron. Our results could
+find applications in designing neuromorphic circuits operating in noisy
+regimes.",2012.03032v3
+2021-01-18,Magnetoelastic properties of a spin-1/2 Ising-Heisenberg diamond chain in vicinity of a triple coexistence point,"We study magnetoelastic properties of a spin-1/2 Ising-Heisenberg diamond
+chain, whose elementary unit cell consists of two decorating Heisenberg spins
+and one nodal Ising spin. It is assumed that each couple of the decorating
+atoms including the Heisenberg spins harmonically vibrates perpendicularly to
+the chain axis, while the nodal atoms involving the Ising spins are placed at
+rigid positions when ignoring their lattice vibrations. An effect of the
+magnetoelastic coupling on a ground state and finite-temperature properties is
+particularly investigated close to a triple coexistence point depending on a
+spring-stiffness constant ascribed to the Heisenberg interaction. The
+magnetoelastic nature of the Heisenberg dimers is reflected through a non-null
+plateau of the entropy emergent in a low-temperature region, whereas the
+specific heat displays an anomalous peak slightly below the temperature region
+corresponding to the entropy plateau. The magnetization also exhibits a plateau
+in the same temperature region at almost saturated value before it gradually
+tends to zero upon increasing of temperature. The magnetic susceptibility
+displays within the plateau region an inverse temperature dependence, which
+slightly drops above this plateau, whereas an inverse temperature dependence is
+repeatedly recovered at high enough temperatures.",2101.07044v1
+2021-03-12,Data-driven low-fidelity models for multi-fidelity Monte Carlo sampling in plasma micro-turbulence analysis,"The linear micro-instabilities driving turbulent transport in magnetized
+fusion plasmas (as well as the respective nonlinear saturation mechanisms) are
+known to be sensitive with respect to various physical parameters
+characterizing the background plasma and the magnetic equilibrium. Therefore,
+uncertainty quantification is essential for achieving predictive numerical
+simulations of plasma turbulence. However, the high computational costs of the
+required gyrokinetic simulations and the large number of parameters render
+standard Monte Carlo techniques intractable. To address this problem, we
+propose a multi-fidelity Monte Carlo approach in which we employ data-driven
+low-fidelity models that exploit the structure of the underlying problem such
+as low intrinsic dimension and anisotropic coupling of the stochastic inputs.
+The low-fidelity models are efficiently constructed via sensitivity-driven
+dimension-adaptive sparse grid interpolation using both the full set of
+uncertain inputs and subsets comprising only selected, important parameters. We
+illustrate the power of this method by applying it to two plasma turbulence
+problems with up to $14$ stochastic parameters, demonstrating that it is up to
+four orders of magnitude more efficient than standard Monte Carlo methods
+measured in single-core performance, which translates into a runtime reduction
+from around eight days to one hour on 240 cores on parallel machines.",2103.07539v2
+2021-04-10,ODMR on Single TR12 Centers in Diamond,"Point defects in insulators are considered promising candidates for quantum
+technologies. In keeping with this, we present an extensive optically-detected
+magnetic resonance (ODMR) study at room-temperature on individual TR12 centers
+(ZPL at 471nm), which are known in the literature since 1956. In this work we
+found TR12 centers to show a strong ODMR signal under optical saturation. These
+observed defects were created in high-purity epitaxial layers of diamond by
+standard irradiation and annealing processes. From the analysis of the ODMR
+spectra along with antibunching measurements and coherent population trapping,
+we proposed the energy level structure of TR12 center, consisting of ground
+state and excited state singlets complemented by a metastable triplet in
+between. Mapping the fluorescence dependence of the center on an external
+magnetic field and on the polarization of laser excitation, allows us to
+identify twelve inequivalent orientations for TR12 centers. This includes the
+exact orientations of the dipole transition and the triplet axes in the diamond
+lattice in full agreement with the results of modeling based on the proposed
+level structure. Furthermore, a static Jahn-Teller effect was detected through
+fluorescence switching between two levels at low optical excitation power,
+directly observable in the real-time fluorescence signal for various
+polarization of laser excitation. Based on these results we discuss the
+prospects of the TR12 center in diamond for quantum sensing and quantum
+information processing.",2104.04746v1
+2021-05-06,Investigating lack of accretion disk eccentricity growth in a global 3D MHD simulation of a superhump system,"We present the results of a 3D global magnetohydrodynamic (MHD) simulation of
+an AM CVn system that was aimed at exploring eccentricity growth in the
+accretion disc self-consistently from a first principles treatment of the MHD
+turbulence. No significant eccentricity growth occurs in the simulation. In
+order to investigate the reasons why, we ran 2D alpha disc simulations with
+alpha values of 0.01, 0.1, and 0.2, and found that only the latter two exhibit
+significant eccentricity growth. We present an equation expressing global
+eccentricity evolution in terms of contributing forces and use it to analyze
+the simulations. As expected, we find that the dominant term contributing to
+the growth of eccentricity is the tidal gravity of the companion star. In the
+2D simulations, the alpha viscosity directly contributes to eccentricity
+growth. In contrast, the overall magnetic forces in the 3D simulation damp
+eccentricity. We also analyzed the mode-coupling mechanism of Lubow, and
+confirmed that the spiral wave excited by the 3:1 resonance was the dominant
+contributor to eccentricity growth in the 2D $\alpha=0.1$ simulations, but
+other waves also contribute significantly. We found that the $\alpha=0.1$ and
+0.2 simulations had more relative mass at larger radii compared to the
+$\alpha=0.01$ and 3D MHD simulation, which also had an effective $\alpha$ of
+0.01. This suggests that in 3D MHD simulations without sufficient poloidal
+magnetic flux, MRI turbulence does not saturate at a high enough $\alpha$ to
+spread the disc to large enough radii to reproduce the superhumps observed in
+real systems.",2105.02392v1
+2021-06-06,Particle Diffusion and Acceleration in Magnetorotational Instability Turbulence,"Hot accretion flows contain collisionless plasmas that are believed to be
+capable of accelerating particles to very high energies, as a result of
+turbulence generated by the magnetorotational instability (MRI). We conduct
+unstratified shearing-box simulations of the MRI turbulence in ideal
+magnetohydrodynamic (MHD), and inject energetic (relativistic) test particles
+in simulation snapshots to conduct a detailed investigation on particle
+diffusion and stochastic acceleration. We consider different amount of net
+vertical magnetic flux to achieve different disk magnetizations levels at
+saturated states, with sufficiently high resolution to resolve the gyro-radii
+($R_g$) of most particles. Particles with large $R_g$ ($\gtrsim0.03$ disk scale
+height $H$) show spatial diffusion coefficients of $\sim30$ and $\sim5$ times
+Bohm values in the azimuthal and poloidal directions, respectively. We further
+measure particle momentum diffusion coefficient $D(p)$ by applying the
+Fokker-Planck equation to particle momentum evolution. For these particles,
+contribution from turbulent fluctuations scales as $D(p)\propto p$, and shear
+acceleration takes over when $R_g\gtrsim0.1H$, characterized by $D(p)\propto
+p^3$. For particles with smaller $R_g$ ($\lesssim0.03H$), their spatial
+diffusion coefficients roughly scale as $\sim p^{-1}$, and show evidence of
+$D(p)\propto p^2$ scaling in momentum diffusion but with large uncertainties.
+We find that multiple effects contribute to stochastic
+acceleration/deceleration, and the process is also likely affected by
+intermittency in the MRI turbulence. We also discuss the potential of
+accelerating PeV cosmic-rays in hot accretion flows around supermassive black
+holes.",2106.03098v1
+2021-06-27,A new low-beta regime for unstable proton firehose modes in bi-Kappa distributed plasmas,"In the solar wind plasma an excess of kinetic temperature along the
+background magnetic field stimulates proton firehose modes to grow if the
+parallel plasma beta parameter is sufficiently high, i.e., $\beta_{p
+\parallel}\gtrsim 1$. This instability can prevent the expansion-driven
+anisotropy from increasing indefinitely, and explain the observations.
+Moreover, such kinetic instabilities are expected to be even more effective in
+the presence of suprathermal Kappa-distributed populations, which are
+ubiquitous in the solar wind, are less affected by collisions than the core
+population, but contribute with an additional free energy. In this work we use
+both linear and extended quasi-linear (QL) frameworks to characterize the
+unstable periodic proton firehose modes (propagating parallel to the magnetic
+field) under the influence of suprathermal protons. Linear theory predicts a
+systematic stimulation of the instability, suprathermals amplifying the growth
+rates and decreasing the instability thresholds to lower anisotropies and lower
+plasma betas ($\beta_{p \parallel}<1$). In perfect agreement with these
+results, the QL approach reveals a significant enhancement of the resulting
+electromagnetic fluctuations up to the saturation with a stronger back reaction
+on protons, leading also to a faster and more efficient relaxation of the
+temperature anisotropy.",2106.14291v1
+2021-06-27,Ferromagnetic Cr4PtGa17: A Novel Half-Heusler-Type Compound with a Breathing Pyrochlore Lattice,"We describe the crystal structure and elementary magnetic properties of a
+previously unreported ternary intermetallic compound, Cr4PtGa17, which
+crystallizes in a rhombohedral unit cell in the noncentrosymmetric space group
+R3m. The crystal structure is closely related to those of XYZ half-Heusler
+compounds, where X, Y and Z are reported to be single elements only, occupying
+three different face-centered cubic sublattices. The new material, Cr4PtGa17,
+can be most straightforwardly illustrated by writing the formula as
+(PtGa2)(Cr4Ga14)Ga (X=PtGa2, Y = Cr4Ga14, Z = Ga), that is, the X and Y sites
+are occupied by clusters instead of single elements. The magnetic Cr occupies a
+breathing pyrochlore lattice. Ferromagnetic ordering is found below TC ~61 K,
+by both neutron diffraction and magnetometer studies, with a small, saturated
+moment of ~0.25 muB/Cr observed at 2 K, making Cr4PtGa17 the first
+ferromagnetically ordered material with a breathing pyrochlore lattice. A
+magnetoresistance of ~140% was observed at 2 K. DFT calculations suggest that
+the material has a nearly-half-metallic electronic structure. The new material,
+Cr4PtGa17, the first realization of both a half-Heusler-type structure and a
+breathing pyrochlore lattice, might pave a new way to achieve novel types of
+half-Heusler compounds.",2106.14296v2
+2021-10-27,Magneto-Thermal Instability In Galaxy Clusters II: Three-Dimensional Simulations,"In the intracluster medium (ICM) of galaxies, exchanges of heat across
+magnetic field lines are strongly suppressed. This anisotropic heat conduction,
+in the presence of a large-scale temperature gradient, destabilizes the
+outskirts of galaxy clusters via the magneto-thermal instability (MTI), and
+thus supplies a source of observed ICM turbulence. In this paper we continue
+our investigation of the MTI with 3D simulations using the Boussinesq code
+SNOOPY. We redress two issues intrinsic to our previous 2D study: an inverse
+energy cascade and the impossibility of dynamo action. Contrary to 2D
+simulations, we find inconsequential transport of energy across scales (most
+energy is dissipated at the same scale as its injection), and that turbulent
+eddies are vertically elongated at or below the thermal conduction length, but
+relatively isotropic on larger scales. Similar to 2D, however, the saturated
+turbulent energy levels and the integral scale follow clear power-laws that
+depend on the thermal diffusivity, temperature gradient, and buoyancy
+frequency. We also show that the MTI amplifies magnetic fields, through a
+fluctuation dynamo, to equipartition strengths provided that the integral scale
+of MTI turbulence is larger than the viscous dissipation scale. Finally, we
+show that our scaling laws are consistent with extant observations of ICM
+turbulence if the thermal conductivity is reduced by a factor of $\sim 10$ from
+its Spitzer value, and that on global cluster scales the stable stratification
+significantly reduces the vertical elongation of MTI motions.",2110.14696v1
+2022-03-02,The Hardness-intensity Correlation of Photospheric Emission from a Structured Jet for Gamma-Ray Bursts,"For many gamma-ray bursts (GRBs), hardness-intensity correlation (HIC) can be
+described by a power-law function, $E_{\rm p}\propto F^{\kappa}$, where $E_{\rm
+p}$ is the peak energy of $\nu F_{\nu}$ spectrum, and $F$ is the instantaneous
+energy flux. In this paper, HIC of the non-dissipative photospheric emission
+from a structured jet is studied in different regimes. An intermediate
+photosphere, which contains both of unsaturated and saturated emissions is
+introduced, and we find positive $\kappa<1/4$ in this case. The same conclusion
+could be generalized to the photospheric emission from a hybrid jet without
+magnetic dissipations, or that with sub-photospheric magnetic dissipations and
+fully thermalized. This may imply that the contribution peaking at $\sim1/2$ in
+the distribution of observed $\kappa$ are mainly from the prompt emission of
+GRBs with synchrotron origin. Besides, emissions of the intermediate
+photosphere could give a smaller low-energy photon index $\alpha$ than that in
+the unsaturated regime, and naturally reproduce anti-correlation in
+$\alpha-E_{\rm p}$ in a GRB pulse.",2203.00882v6
+2022-05-20,Band Structure Driven Thermoelectric Response of Topological Semiconductor ZrTe$_5$,"We report a transport, thermodynamic, and spectroscopic study of the recently
+identified topological semiconductor ZrTe$_5$ with a focus on elucidating the
+connections between its band structure and unusual thermoelectric properties.
+Using time and angle resolved photoemission spectroscopy (tr-ARPES) we observe
+a small electronic band gap and temperature dependent Fermi level which
+traverses from a single valence to conduction band with lowering temperature,
+consistent with previous reports. This low temperature Fermi surface closely
+matches that derived from quantum oscillations, suggesting it is reflective of
+the bulk electronic structure. The Seebeck and low field Nernst response is
+characterized by an unusually large and non-monotonic temperature evolution. We
+find this can be quantitatively explained using a semiclassical model based on
+the observed band character and a linear temperature shifting of the Fermi
+level. Additionally, we observe a large, non-saturating enhancement of both
+thermoelectric coefficients in magnetic field. We show this can be captured by
+the Zeeman energy associated with a large effective $g$-factor of 25.8
+consistent with that derived from Lifshitz-Kosevich analysis of the quantum
+oscillations. Together these observations provide a comprehensive picture of
+ZrTe$_{5}$ as a model high mobility semiconductor and potential platform for
+significant magnetic field driven thermoelectricity.",2205.10394v1
+2022-06-17,Thermal conductivity of triangular-lattice antiferromagnet Na2BaCo(PO4)2: Absence of itinerant fermionic excitations,"We present the ultralow-temperature specific heat and thermal conductivity
+measurements on single crystals of triangular-lattice antiferromagnet
+Na$_2$BaCo(PO$_4$)$_2$, which was recently argued to host itinerant fermionic
+excitations, like a quantum spin liquid, above its antiferromagnetic phase
+transition temperature $T_{\rm N}$ = 0.148 K. In specific heat measurements, we
+confirm the peaks due to antiferromagnetic ordering when magnetic field $\mu_0
+H \leq$ 1 T, roughly consistent with previous work [N. Li $et$ $al.$, Nat.
+Commun. 11, 4216 (2020)]. However, in thermal conductivity measurements, we
+observe negligible residual linear term in zero and finite magnetic fields, in
+sharp contrast to previous report [N. Li $et$ $al.$, Nat. Commun. 11, 4216
+(2020)]. At 0.35 K, the thermal conductivity increases with field up to 3 T
+then saturates, similar to that of another triangular-lattice compound
+YbMgGaO$_4$, which further shows that the heat is conducted only by phonons
+with scattering from spins and boundary. Our results clearly demonstrate the
+absence of itinerant fermionic excitations in the disordered state above
+$T_{\rm N}$ in this frustrated antiferromagnet Na$_2$BaCo(PO$_4$)$_2$, thus
+such a state is not as exotic as previously reported.",2206.08866v1
+2022-08-01,Effect of magnetism and phonons on localized carriers in the ferrimagnetic kagome metals GdMn$_6$Sn$_6$ and TbMn$_6$Sn$_6$,"Kagome metals possess peculiar optical spectra consisting of contributions
+from free charge carriers in a Drude-type response, localized carriers seen as
+a strongly temperature-dependent localization peak, and, in some cases, phonons
+displaying strong anomalies. The rare-earth kagome metal series,
+$R$Mn$_6$Sn$_6$, provides a marvelous playground to study the electronic
+properties of kagome metals in the presence of variable magnetic order. Here,
+we report temperature-dependent reflectivity studies on two members of the
+$R$Mn$_6$Sn$_6$ family, GdMn$_6$Sn$_6$ (in-plane ferrimagnet) and
+TbMn$_6$Sn$_6$ (out-of-plane ferrimagnet), in a broad energy range (50 - 18000
+cm$^{-1}$, equivalent to 6.2 meV - 2.23 eV) down to 10 K. At high temperatures,
+a phonon mode at approximately 160 cm$^{-1}$ is observed, which becomes
+screened out in TbMn$_6$Sn$_6$ below $\sim$ 150 K as the localization peak
+linearly passes through the mode. In GdMn$_6$Sn$_6$, the disappearance of the
+phonon is accompanied by the onset of saturation of the peak position,
+suggesting an unusual interplay between the two features.",2208.00756v2
+2022-08-15,Valley-coherent quantum anomalous Hall state in AB-stacked MoTe2/WSe2 bilayers,"Moir\'e materials provide fertile ground for the correlated and topological
+quantum phenomena. Among them, the quantum anomalous Hall (QAH) effect, in
+which the Hall resistance is quantized even under zero magnetic field, is a
+direct manifestation of the intrinsic topological properties of a material and
+an appealing attribute for low-power electronics applications. The QAH effect
+has been observed in both graphene and transition metal dichalcogenide (TMD)
+moir\'e materials. It is thought to arise from the interaction-driven valley
+polarization of the narrow moir\'e bands. Here, we show surprisingly that the
+newly discovered QAH state in AB-stacked MoTe2/WSe2 moir\'e bilayers is not
+valley-polarized but valley-coherent. The layer- and helicity-resolved optical
+spectroscopy measurement reveals that the QAH ground state possesses
+spontaneous spin (valley) polarization aligned (anti-aligned) in two TMD
+layers. In addition, saturation of the out-of-plane spin polarization in both
+layers occurs only under high magnetic fields, supporting a canted spin
+texture. Our results call for a new mechanism for the QAH effect and highlight
+the potential of TMD moir\'e materials with strong electronic correlations and
+spin-orbit interactions for exotic topological states.",2208.07452v1
+2022-09-12,Recursive Prediction Error Gradient-Based Algorithms and Framework to Identify PMSM Parameters Online,"Real-time acquisition of accurate machine parameters is of significance to
+achieving high performance in electric drives, particularly targeted for
+mission-critical applications. Unlike the saturation effects, the temperature
+variations are difficult to predict, thus it is essential to track
+temperature-dependent parameters online. In this paper, a unified framework is
+developed for online parameter identification of rotating electric machines,
+premised on the Recursive Prediction Error Method (RPEM). Secondly, the
+prediction gradient ($\mathbf{\Psi}^T$)-based RPEM is adopted for
+identification of the temperature-sensitive parameters, i.e., the permanent
+magnet flux linkage ($\Psi_m$) and stator-winding resistance ($R_s$) of the
+Interior Permanent Magnet Synchronous Machine (IPMSM). Three algorithms,
+namely, Stochastic Gradient (SGA), Gauss-Newton (GNA), and physically
+interpretative method (PhyInt) are investigated for the estimation gains
+computation. A speed-dependent gain-scheduling scheme is used to decouple the
+inter-dependency of $\Psi_m$ and $R_s$. With the aid of offline simulation
+methods, the main elements of RPEM such as $\mathbf{\Psi}^T$ are analyzed. The
+concept validation and the choice of the optimal algorithm is made with the use
+of System-on-Chip (SoC) based Embedded Real-Time Simulator (ERTS).
+Subsequently, the selected algorithms are validated with the aid of a 3-kW,
+IPMSM drive where the control and estimation routines are implemented in the
+SoC-based industrial embedded control system. The experimental results reveal
+that $\mathbf{\Psi}^T$-based RPEM, in general, can be a versatile technique in
+temperature-sensitive parameter adaptation both online and offline.",2209.05094v1
+2022-10-10,Complete field-induced spectral response of the spin-1/2 triangular-lattice antiferromagnet CsYbSe$_2$,"Fifty years after Anderson's resonating valence-bond proposal, the spin-1/2
+triangular-lattice Heisenberg antiferromagnet (TLHAF) remains the ultimate
+platform to explore highly entangled quantum spin states in proximity to
+magnetic order. Yb-based delafossites are ideal candidate TLHAF materials,
+which allow experimental access to the full range of applied in-plane magnetic
+fields. We perform a systematic neutron scattering study of CsYbSe$_2$, first
+proving the Heisenberg character of the interactions and quantifying the
+second-neighbour coupling. We then measure the complex evolution of the
+excitation spectrum, finding extensive continuum features near the
+120$^{\circ}$-ordered state, throughout the 1/3-magnetization plateau and
+beyond this up to saturation. We perform cylinder matrix-product-state (MPS)
+calculations to obtain an unbiased numerical benchmark for the TLHAF and
+spectacular agreement with the experimental spectra. The measured and
+calculated longitudinal spectral functions reflect the role of multi-magnon
+bound and scattering states. These results provide valuable insight into
+unconventional field-induced spin excitations in frustrated quantum materials.",2210.04928v3
+2022-11-08,The Impact of Cosmic Ray Injection on Magnetic Flux Tubes in a Galactic Disk,"In galactic disks, the Parker instability results when non-thermal pressure
+support exceeds a certain threshold. The non-thermal pressures considered in
+the Parker instability are cosmic ray pressure and magnetic pressure. This
+instability takes a long time to saturate $(>500 \, \mathrm{Myr})$ and assumes
+a background with fixed cosmic ray pressure to gas pressure ratio. In reality,
+galactic cosmic rays are injected into localized regions $(< 100
+\,\mathrm{pc})$ by events like supernovae, increasing the cosmic ray pressure
+to gas pressure ratio. In this work, we examine the effect of such cosmic ray
+injection on large scales $ (\sim 1\,\mathrm{kpc})$ in cosmic ray
+magnetohydrodynamic simulations using the \texttt{Athena++} code. We vary the
+background properties, dominant cosmic ray transport mechanism, and injection
+characteristics between our simulation runs. We find the injection will disrupt
+the interstellar medium on shorter timescales than the Parker instability. If
+cosmic ray transport by advection is dominant, cosmic ray injection disrupts
+the disk on short time scales $(<100\,\mathrm{Myr})$. If cosmic ray transport
+by the streaming instability is dominant, the injection creates a buoyant flux
+tube long after the initial injection $(>150\,\mathrm{Myr})$. Finally, when
+cosmic ray transport by diffusion dominates, the injected cosmic rays make an
+entire flux tube over pressured in a short time $(\sim 10 \, \mathrm{Myr})$.
+This over pressure pushes gas off the tube and drives buoyant rise on time
+scales similar to the advection dominated case.",2211.04503v2
+2022-12-02,Polarized Maser Emission with In-Source Faraday Rotation,"We discuss studies of polarization in astrophysical masers with particular
+emphasis on the case where the Zeeman splitting is small compared to the
+Doppler profile, resulting in a blend of the transitions between magnetic
+substates. A semi-classical theory of the molecular response is derived, and
+coupled to radiative transfer solutions for 1 and 2-beam linear masers,
+resulting in a set of non-linear, algebraic equations for elements of the
+molecular density matrix. The new code, PRISM, implements numerical methods to
+compute these solutions. Using PRISM, we demonstrate a smooth transfer between
+this case and that of wider splitting. For a J=1-0 system, with parameters
+based on the $v=1, J=1-0$ transition of SiO, we investigate the behaviour of
+linear and circular polarization as a function of the angle between the
+propagation axis and the magnetic field, and with the optical depth, or
+saturation state, of the model. We demonstrate how solutions are modified by
+the presence of Faraday rotation, generated by various abundances of free
+electrons, and that strong Faraday rotation leads to additional angles where
+Stokes-Q changes sign. We compare our results to a number of previous models,
+from the analytical limits derived by Goldreich, Keeley and Kwan in 1973,
+through computational results by W. Watson and co-authors, to the recent work
+by Lankhaar and Vlemmings in 2019. We find that our results are generally
+consistent with those of other authors given the differences of approach and
+the approximations made.",2212.01410v1
+2023-04-06,How baryons appear in low-energy QCD: Domain-wall Skyrmion phase in strong magnetic fields,"Low-energy dynamics of QCD can be described by pion degrees of freedom in
+terms of the chiral perturbation theory(ChPT). A chiral soliton lattice(CSL),
+an array of solitons, is the ground state due to the chiral anomaly in the
+presence of a magnetic field larger than a certain critical value at finite
+density. Here, we show in a model-independent and fully analytic manner (at the
+leading order of ChPT) that the CSL phase transits to a {\it domain-wall
+Skyrmion phase} when the chemical potential is larger than the critical value
+$\mu_{\rm c} = 16\pi f_{\pi}^2/3m_{\pi} \sim 1.03 \;\; {\rm GeV}$ with the
+pion's decay constant $f_{\pi}$ and mass $m_{\pi}$, which can be regarded as
+the nuclear saturation density. There spontaneously appear stable
+two-dimensional Skyrmions or lumps on a soliton surface, which can be viewed as
+three-dimensional Skyrmions carrying even baryon numbers from the bulk despite
+no Skyrme term. They behave as superconducting rings with persistent currents
+due to a charged pion condensation, and areas of the rings' interiors are
+quantized. This phase is in scope of future heavy-ion collider experiments.",2304.02940v1
+2023-07-17,Slonczewski-spin-current driven dynamics of 180$^{\circ}$ domain walls in spin valves with interfacial Dzyaloshinskii-Moriya interaction,"Steady-flow dynamics of ferromagnetic 180$^{\circ}$ domain walls (180DWs) in
+long and narrow spin valves (LNSVs) with interfacial Dzyaloshinskii-Moriya
+interaction (IDMI) under spin currents with Slonczewski $g-$factor are
+examined. Depending on the magnetization orientation of polarizers (pinned
+layers of LNSVs), dynamics of 180DWs in free layers of LNSVs are subtly
+manipulated: (i) For parallel polarizers, stronger spin polarization leads to
+higher Walker limit thus ensures the longevity of faster steady flows.
+Meantime, IDMI induces both the stable-region flapping and its width
+enlargement. (ii) For perpendicular polarizers, a wandering of 180DWs between
+bi- and tri-stability persists with the criticality adjusted by the IDMI. (iii)
+For planar-transverse polarizers, IDMI makes the stable region of steady flows
+completely asymmetric and further imparts a high saturation wall velocity under
+large current density. Under the last two polarizers, the ultrahigh
+differential mobility of 180DWs survives. The combination of Slonczewski spin
+current and IDMI provides rich possibilities of fine controlling on 180DW
+dynamics, hence opens avenues for magnetic nanodevices with rich functionality
+and high robustness.",2307.08419v1
+2023-08-21,Unravelling the Period Gap using LAMOST Chromospheric Activity Indices,"In our recent catalogue of BY Draconis (BY Dra) variables based on Zwicky
+Transient Facility data, we found traces of a period gap in the period-colour
+diagram. We combined our BY Dra database with catalogues from the {\sl Kepler}
+and K2 surveys, revealing a prominent period gap. Here, we use this combined
+ZTF-{\sl Kepler}-K2 data set to investigate the origin of the period gap
+observed for BY Dra stars using chromospheric activity indices. We use low- and
+medium-resolution spectra from the LAMOST Data Release 7 to derive magnetic
+activity indices for the Ca {\sc ii} H and K and H$\alpha$ emission lines. We
+find a strong dependence of chromospheric activity on both stellar mass and
+rotation period. For partially convective K-M-type stars, the activity
+decreases steeply up to an age of $\sim$700-1000 Myr, subsequently evolving to
+the type of low-level saturation associated with spin-down stallation. In
+contrast, F-G-type stars with thinner convective envelopes exhibit constant
+activity with increasing age. We suspect that the observed steep decrease for
+partially convective stars is driven by core-envelope coupling. This mechanism
+reduces differential rotation at the core-envelope transition, hence leading to
+decreased magnetic activity. Moreover, we derive activity indices for
+previously known star clusters and find similar trends as regards their
+activity levels as a function of age. In particular, very low-level activity is
+observed around the location of the period gap. Therefore, we conclude that the
+period gap, defined by the non-detection of variable sources, is driven by a
+minimum in chromospheric activity.",2308.10539v1
+2023-09-14,Microscopic study of the impurity effect in the kagome superconductor La(Ru$_{1-x}$Fe$_{x}$)$_{3}$Si$_{2}$,"We report on the effect of magnetic impurities on the microscopic
+superconducting (SC) properties of the kagome-lattice superconductor
+La(Ru$_{1-x}$Fe$_{x}$)$_{3}$Si$_{2}$ using muon spin relaxation/rotation. A
+strong suppression of the superconducting critical temperature $T_{\rm c}$, the
+SC volume fraction, and the superfluid density was observed. We further find a
+correlation between the superfluid density and $T_{\rm c}$ which is considered
+a hallmark feature of unconventional superconductivity. Most remarkably,
+measurements of the temperature-dependent magnetic penetration depth
+${\lambda}$ reveal a change in the low-temperature behavior from exponential
+saturation to a linear increase, which indicates that Fe doping introduces
+nodes in the superconducting gap structure at concentrations as low as
+$x=$~0.015. Our results point to a rare example of unconventional
+superconductivity in the correlated kagome lattice and accessible tunability of
+the superconducting gap structure, offering new insights into the microscopic
+mechanisms involved in superconducting order.",2309.07827v2
+2023-11-14,"A cool, magnetic white dwarf accreting planetary debris","We present an analysis of spectroscopic data of the cool, highly magnetic and
+polluted white dwarf 2MASS J0916-4215. The atmosphere of the white dwarf is
+dominated by hydrogen, but numerous spectral lines of magnesium, calcium,
+titanium, chromium, iron, strontium, along with Li I, Na I, Al I, and K I
+lines, are found in the incomplete Paschen-Back regime, most visibly, in the
+case of Ca II lines. Extensive new calculations of the Paschen-Back effect in
+several spectral lines are presented and results of the calculations are
+tabulated for the Ca II H&K doublet. The abundance pattern shows a large
+lithium and strontium excess, which may be viewed as a signature of planetary
+debris akin to Earth's continental crust accreted onto the star, although the
+scarcity of silicon indicates possible dilution in bulk Earth material.
+Accurate abundance measurements proved sensitive to the value of the broadening
+parameter due to collisions with neutral hydrogen (Gamma_HI), particularly in
+saturated lines such as the resonance lines of Ca I and Ca II. We found that
+Gamma_HI if formulated with values from the literature could be overestimated
+by a factor of 10 in most resonance lines.",2311.07937v1
+2024-03-13,Chiral spin state and nematic ferromagnet in the spin-1 Kitaev-$Γ$ model,"The higher-spin Kitaev magnets, in which the Kitaev interaction and
+off-diagonal exchange couplings are overwhelmingly large, have emerged as a
+fertile avenue to explore exotic phases and unusual excitations. In this work,
+we study the quantum phase diagram of the spin-1 Kitaev-$\Gamma$ model on the
+honeycomb lattice using density-matrix renormalization group. It harbours six
+distinct phases and the intriguing findings are three magnetically ordered
+phases in which both time-reversal symmetry and lattice symmetry albeit of
+different sort are broken spontaneously. The chiral spin state originates from
+the order-by-disorder effect and exhibits an almost saturated scalar spin
+chirality at the quantum level. Depending on the relative strength of the two
+interactions, it also features columnar or plaquette valence-bond-solid-like
+pattern as a consequence of the translational symmetry breaking. In parallel,
+the nematic ferromagnets are situated at ferromagnetic Kitaev side and possess
+small but finite ferromagnetic ordering. The lattice-rotational symmetry
+breaking enforces nonequivalent bond energy along one of the three bonds.
+Although the intrinsic difference between the two nematic ferromagnets remains
+elusive, the discontinuities in the von Neumann entropy, hexagonal plaquette
+operator, and Wilson loop operator convincingly suggest that they are separated
+via a first-order phase transition.",2403.08382v1
+2004-09-27,Bunching instability of rotating relativistic electron layers and coherent synchrotron radiation,"We study the stability of a collisionless, relativistic, finite-strength,
+cylindrical layer of charged particles in free space by solving the linearized
+Vlasov-Maxwell equations and compute the power of the emitted electromagnetic
+waves. The layer is rotating in an external magnetic field parallel to the
+layer. This system is of interest to understanding the high brightness
+temperature of pulsars which cannot be explained by an incoherent radiation
+mechanism. Coherent synchrotron radiation has also been observed recently in
+bunch compressors used in particle accelerators. We consider equilibrium layers
+with a `thermal' energy spread and therefore a non-zero radial thickness. The
+particles interact with their retarded electromagnetic self-fields. The effect
+of the betatron oscillations is retained. A short azimuthal wavelength
+instability is found which causes a modulation of the charge and current
+densities. The growth rate is found to be an increasing function of the
+azimuthal wavenumber, a decreasing function of the Lorentz factor, and
+proportional to the square root of the total number of electrons. We argue that
+the growth of the unstable perturbation saturates when the trapping frequency
+of electrons in the wave becomes comparable to the growth rate. Owing to this
+saturation we can predict the radiation spectrum for a given set of parameters.
+Our predicted brightness temperatures are proportional to the square of the
+number of particles and scale by the inverse five-third power of the azimuthal
+wavenumber which is in rough accord with the observed spectra of radio pulsars.",0409645v2
+2005-06-22,The Origin of T Tauri X-ray Emission: New Insights from the Chandra Orion Ultradeep Project,"We use the data of the Chandra Orion Ultradeep Project (COUP) to study the
+nearly 600 X-ray sources that can be reliably identified with optically well
+characterized T Tauri stars (TTS) in the Orion Nebula Cluster. We detect X-ray
+emission from more than 97% of the optically visible late-type (spectral types
+F to M) cluster stars. This proofs that there is no ``X-ray quiet'' population
+of late-type stars with suppressed magnetic activity. All TTS with known
+rotation periods lie in the saturated or super-saturated regime of the relation
+between activity and Rossby numbers seen for main-sequence (MS) stars, but the
+TTS show a much larger scatter in X-ray activity than seen for the MS stars.
+Strong near-linear relations between X-ray luminosities, bolometric
+luminosities and mass are present. We also find that the fractional X-ray
+luminosity rises slowly with mass over the 0.1 - 2 M_sun range. The plasma
+temperatures determined from the X-ray spectra of the TTS are much hotter than
+in MS stars, but seem to follow a general solar-stellar correlation between
+plasma temperature and activity level. The large scatter about the relations
+between X-ray activity and stellar parameters seems to be related to the
+influence of accretion on the X-ray emission. While the X-ray activity of the
+non-accreting TTS is consistent with that of rapidly rotating MS stars, the
+accreting stars are less X-ray active (by a factor of ~2-3 on average) and
+produce much less well defined correlations than the non-accretors. We discuss
+possible reasons for the suppression of X-ray emission by accretion and the
+implications of our findings on long-standing questions related to the origin
+of the X-ray emission from young stars.",0506526v1
+2010-11-02,Discovery of a QPO in the X-ray pulsar 1A 1118-615: correlated spectral and aperiodic variability,"Our goal is to investigate the X-ray timing and spectral variability of the
+high-mass X-ray binary 1A 1118-615 during a type-II outburst. We performed a
+detailed color, spectral and timing analysis of a giant outburst from 1A
+1118-615, using RXTE data. Results. We report the discovery of a variable
+quasi-periodic oscillation (QPO) in the power spectral density of 1A 1118-615,
+with a centroid frequency of ~0.08 Hz. The centroid frequency of the QPO
+correlates with the X-ray flux, as expected according to the most accredited
+models for QPO production. For energies above ~4 keV, the QPO rms variability
+decreases as the energy increases. Pulse profiles display energy dependence,
+with a two-peak profile at lower energies, and a single peak at higher
+energies. From spectral analysis, we confirm the presence of a cyclotron
+absorption feature at ~60 keV, the highest value measured for an X-ray pulsar.
+We find that the spectral parameters (photon index, cutoff energy, iron
+fluorescence line strength) display a marked dependence with flux. We detect
+two different levels of neutral hydrogen column density, possibly due to the Be
+companion activity. We report for the first time a correlation between the
+timing and spectral parameters in an X-ray pulsar. All the correlations found
+between spectral/timing parameters and X-ray flux are present up to a flux of
+~6x10^-9 erg cm^-2 s^-1, when a saturation level is reached. We propose that
+the saturation observed corresponds to the minimum extent of the neutron star
+magnetosphere. We estimate the magnetic field of the neutron star from two
+independent ways, using results from spectral (cyclotron line energy) and
+timing (QPO frequency) analysis, obtaining consistent values, of ~7-8x10^12 G.
+Results from the comprehensive spectral and timing analysis are discussed in
+comparison with other X-ray pulsars.",1011.0564v2
+2011-09-29,Geosynchronous magnetopause crossings: necessary conditions,"The experimental data on GOES magnetic measurements and plasma measurements
+on LANL geosynchronous satellites is used for selection of 169 case events
+containing 638 geosynchronous magnetopause crossings (GMCs) in 1995 to 2001. We
+study the necessary conditions for the geosynchronous magnetopause crossings
+using scatter plot of the GMCs in the coordinate space of Psw versus Bz. In
+such representation the upstream solar wind conditions demonstrate sharp
+envelope boundary under which no GMCs are occurred. The boundary has two strait
+horizontal branches where Bz does not influence on the magnetopause location.
+The first branch is located in the range of Psw=21 nPa for large positive Bz
+and is associated with an asymptotic regime of the pressure balance. The second
+branch asymptotically approaches to the range of Psw=4.8 nPa under very strong
+negative Bz and it is associated with a regime of the Bz influence saturation.
+We suggest that the saturation is caused by relatively high contribution of the
+magnetosphere thermal pressure into the pressure balance on the magnetopause.
+The intermediate region of the boundary for the moderate negative and small
+positive IMF Bz can be well approximated by a hyperbolic tangent function. We
+interpret the envelope boundary as a range of necessary upstream solar wind
+conditions required for GMC in the point on the magnetopause located mostly
+close to the Earth (""perigee"" point). We obtain that the dipole tilt angle and
+dawn-dusk asymmetry influence on the ""perigee"" point location. We find that the
+aGSM latitude of this point depends linearly on the dipole tilt angle with the
+slope about -0.5. The aGSM longitude of the ""perigee"" point decreases with IMF
+Bz with a rate of about 2 angular minutes per 1 nT. An empirical model
+predicting the magnetopause crossing of the geosynchronous orbit in the
+""perigee"" point is proposed.",1109.6513v2
+2014-02-24,Time resolved spectroscopy of SGR J1550-5418 bursts detected with Fermi/GBM,"We report on time-resolved spectroscopy of the 63 brightest bursts of SGR
+J1550-5418, detected with Fermi/Gamma-ray Burst Monitor during its 2008-2009
+intense bursting episode. We performed spectral analysis down to 4 ms
+time-scales, to characterize the spectral evolution of the bursts. Using a
+Comptonized model, we find that the peak energy, E_peak, anti-correlates with
+flux, while the low-energy photon index remains constant at -0.8 up to a flux
+limit F~10^-5 erg s-1 cm-2. Above this flux value the E_peak-flux correlation
+changes sign, and the index positively correlates with flux reaching 1 at the
+highest fluxes. Using a two black-body model, we find that the areas and fluxes
+of the two emitting regions correlate positively. Further, we study here for
+the first time, the evolution of the temperatures and areas as a function of
+flux. We find that the area-kT relation follows lines of constant luminosity at
+the lowest fluxes, R^2 \propto kT^-4, with a break at higher fluxes ($F>10^-5.5
+erg s-1 cm-2). The area of the high-kT component increases with flux while its
+temperature decreases, which we interpret as due to an adiabatic cooling
+process. The area of the low-kT component, on the other hand, appears to
+saturate at the highest fluxes, towards R_max~30 km. Assuming that crust quakes
+are responsible for SGR bursts and considering R_max as the maximum radius of
+the emitting photon-pair plasma fireball, we relate this saturation radius to a
+minimum excitation radius of the magnetosphere, and put a lower limit on the
+internal magnetic field of SGR J1550-5418, B_int>~4.5x10^15 G.",1402.6015v1
+2014-07-07,Rossby and Drift Wave Turbulence and Zonal Flows: the Charney-Hasegawa-Mima model and its extensions,"A detailed study of the Charney-Hasegawa-Mima model and its extensions is
+presented. These simple nonlinear partial differential equations suggested for
+both Rossby waves in the atmosphere and also drift waves in a
+magnetically-confined plasma exhibit some remarkable and nontrivial properties,
+which in their qualitative form survive in more realistic and complicated
+models, and as such form a conceptual basis for understanding the turbulence
+and zonal flow dynamics in real plasma and geophysical systems. Two idealised
+scenarios of generation of zonal flows by small-scale turbulence are explored:
+a modulational instability and turbulent cascades.
+  A detailed study of the generation of zonal flows by the modulational
+instability reveals that the dynamics of this zonal flow generation mechanism
+differ widely depending on the initial degree of nonlinearity. A numerical
+proof is provided for the extra invariant in Rossby and drift wave turbulence
+-zonostrophy and the invariant cascades are shown to be characterised by the
+zonostrophy pushing the energy to the zonal scales.
+  A small scale instability forcing applied to the model demonstrates the
+well-known drift wave - zonal flow feedback loop in which the turbulence which
+initially leads to the zonal flow creation, is completely suppressed and the
+zonal flows saturate. The turbulence spectrum is shown to diffuse in a manner
+which has been mathematically predicted.
+  The insights gained from this simple model could provide a basis for
+equivalent studies in more sophisticated plasma and geophysical fluid dynamics
+models in an effort to fully understand the zonal flow generation, the
+turbulent transport suppression and the zonal flow saturation processes in both
+the plasma and geophysical contexts as well as other wave and turbulence
+systems where order evolves from chaos.",1407.1896v1
+2017-04-07,Simultaneous 183 GHz H2O Maser and SiO Observations Towards Evolved Stars Using APEX SEPIA Band 5,"We investigate the use of 183 GHz H2O masers for characterization of the
+physical conditions and mass loss process in the circumstellar envelopes of
+evolved stars. We used APEX SEPIA Band 5 to observe the 183 GHz H2O line
+towards 2 Red Supergiant and 3 Asymptotic Giant Branch stars. Simultaneously,
+we observed lines in 28SiO v0, 1, 2 and 3, and for 29SiO v0 and 1. We detected
+the 183 GHz H2O line towards all the stars with peak flux densities greater
+than 100 Jy, including a new detection from VY CMa. Towards all 5 targets, the
+water line had indications of being due to maser emission and had higher peak
+flux densities than for the SiO lines. The SiO lines appear to originate from
+both thermal and maser processes. Comparison with simulations and models
+indicate that 183 GHz maser emission is likely to extend to greater radii in
+the circumstellar envelopes than SiO maser emission and to similar or greater
+radii than water masers at 22, 321 and 325 GHz. We speculate that a prominent
+blue-shifted feature in the W Hya 183 GHz spectrum is amplifying the stellar
+continuum, and is located at a similar distance from the star as mainline OH
+maser emission. From a comparison of the individual polarizations, we find that
+the SiO maser linear polarization fraction of several features exceeds the
+maximum fraction allowed under standard maser assumptions and requires strong
+anisotropic pumping of the maser transition and strongly saturated maser
+emission. The low polarization fraction of the H2O maser however, fits with the
+expectation for a non-saturated maser. 183 GHz H2O masers can provide strong
+probes of the mass loss process of evolved stars. Higher angular resolution
+observations of this line using ALMA Band 5 will enable detailed investigation
+of the emission location in circumstellar envelopes and can also provide
+information on magnetic field strength and structure.",1704.02133v1
+2017-09-15,Pressure-anisotropy-induced nonlinearities in the kinetic magnetorotational instability,"In collisionless and weakly collisional plasmas, such as hot accretion flows
+onto compact objects, the magnetorotational instability (MRI) can differ
+significantly from the standard (collisional) MRI. In particular, pressure
+anisotropy with respect to the local magnetic-field direction can both change
+the linear MRI dispersion relation and cause nonlinear modifications to the
+mode structure and growth rate, even when the field and flow perturbations are
+small. This work studies these pressure-anisotropy-induced nonlinearities in
+the weakly nonlinear, high-ion-beta regime, before the MRI saturates into
+strong turbulence. Our goal is to better understand how the saturation of the
+MRI in a low collisionality plasma might differ from that in the collisional
+regime. We focus on two key effects: (i) the direct impact of self-induced
+pressure-anisotropy nonlinearities on the evolution of an MRI mode, and (ii)
+the influence of pressure anisotropy on the ""parasitic instabilities"" that are
+suspected to cause the mode to break up into turbulence. Our main conclusions
+are: (i) The mirror instability regulates the pressure anisotropy in such a way
+that the linear MRI in a collisionless plasma is an approximate nonlinear
+solution once the mode amplitude becomes larger than the background field (just
+as in MHD). This implies that differences between the collisionless and
+collisional MRI become unimportant at large amplitudes. (ii) The break up of
+large amplitude MRI modes into turbulence via parasitic instabilities is
+similar in collisionless and collisional plasmas. Together, these conclusions
+suggest that the route to magnetorotational turbulence in a collisionless
+plasma may well be similar to that in a collisional plasma, as suggested by
+recent kinetic simulations. As a supplement to these findings, we offer
+guidance for the design of future kinetic simulations of magnetorotational
+turbulence.",1709.05428v2
+2018-03-10,Quantum Dimensional Transition in Spin-$\frac{1}{2}$ Antiferromagnetic Heisenberg Model on A Square Lattice and Space Reduction in Matrix Product State,"We study the spin-$\frac{1}{2}$ antiferromagnetic Heisenberg model on an
+infinity-by-$N$ square lattice for even $N$'s up to $14$. Previously, the
+nonlinear sigma model perturbatively predicts that its spin rotational symmetry
+asymptotically breaks when $N\rightarrow \infty$, i.e., when it is
+two-dimensional (2D). However, we identified a critical width $N_c = 10$ for
+which this symmetry breaks spontaneously. It defines a dimensional transition
+from one-dimension (1D) including quasi-1D to 2D. The finite-size effect
+differs from that of the $N$-by-$N$ lattice. The ground state (GS) energy per
+site approaches the thermodynamic limit value, in agreement with the previously
+accepted value, by one order of $1/N$ faster than when using $N$-by-$N$
+lattices in the literature. We build and variationally solve a matrix product
+state (MPS) on a chain, converting the $N$ sites in the rung into an effective
+site. We show that the area law of entanglement entropy does not apply when $N$
+increases in our method, and show that the reduced density matrix of each
+effective site will have a saturating number of dominant diagonal elements with
+increasing $N$. These two characteristics make the MPS rank needed to obtain a
+demanded energy accuracy quickly saturate when $N$ is large, making our
+algorithm efficient for large $N$'s. And, the latter enables space reduction in
+MPS. Within the framework of MPS, we prove a theorem that the spin-spin
+correlation at infinite separation is the square of staggered magnetization and
+demonstrate that the eigenvalue structure of a building MPS unit of $\langle
+g\mid g\rangle$, $\mid g\rangle$ being the GS, is responsible for order,
+disorder and quasi-long-range order.",1803.03779v2
+2018-12-18,Two-dimensional Ca-Cl crystals under ambient conditions observed directly by cryo-electron microscopy,"Recently, we report the direct observation, under ambient conditions, of
+Na2Cl and Na3Cl as two-dimensional (2D) Na-Cl crystals, together with regular
+NaCl, on reduced graphene oxide membranes and on the surfaces of natural
+graphite powders from salt solutions far below the saturated concentration.
+However, what are these abnormal stoichiometries for high valence ions, such as
+calcium ions and copper ions still remain unknown. Here, using cryo-electron
+microscopy, we report the direct observation of two-dimensional (2D) Ca-Cl
+crystals on reduced graphene oxide (rGO) membranes, in which the calcium ions
+are only monovalent (i.e. +1). Remarkably, metallic properties rather than
+insulating are displayed by those CaCl crystals. We note that such CaCl
+crystals are obtained by simply incubating rGO membranes in salt solutions
+below the saturated concentration, under ambient conditions. Theoretical
+studies show that the formation of those abnormal crystals is attributed to the
+strong cation-pi interactions of the Ca2+ ions with the aromatic rings in the
+graphitic surfaces. Since strong cation-pi interactions also exist between
+other metal ions (such as Mg2+, Fe2+, Co2+, Cu2+, Cd2+, Cr2+ and Pb2+) and
+graphitic surfaces, similar 2D crystals with abnormal valence state of the
+metal cations and corresponding abnormal properties are highly expected. The 2D
+crystals with monovalent calcium ions show unusual electronic properties, and
+can be applicated in catalyzer, hydrogen storage, high-performance conducting
+electrodes and sensors. These findings also produce functionalized graphene
+including compact ""graphene-metallic CaCl-insulating CaCl2"" junction that can
+serve as transistors down to the atomic scale, and other devices for magnetic,
+optical and mechanical applications.",1812.07195v1
+2019-01-29,Higher superconducting transition temperature by breaking the universal pressure relation,"By investigating the bulk superconducting state via dc magnetization
+measurements, we have discovered a common resurgence of the superconductive
+transition temperatures (Tcs) of the monolayer Bi2Sr2CuO6+{\delta} (Bi2201) and
+bilayer Bi2Sr2CaCu2O8+{\delta} (Bi2212) to beyond the maximum Tcs (Tc-maxs)
+predicted by the universal relation between Tc and doping (p) or pressure (P)
+at higher pressures. The Tc of under-doped Bi2201 initially increases from 9.6
+K at ambient to a peak at ~ 23 K at ~ 26 GPa and then drops as expected from
+the universal Tc-P relation. However, at pressures above ~ 40 GPa, Tc rises
+rapidly without any sign of saturation up to ~ 30 K at ~ 51 GPa. Similarly, the
+Tc for the slightly overdoped Bi2212 increases after passing a broad valley
+between 20-36 GPa and reaches ~ 90 K without any sign of saturation at ~ 56
+GPa. We have therefore attributed this Tc-resurgence to a possible
+pressure-induced electronic transition in the cuprate compounds due to a charge
+transfer between the Cu 3d_(x^2-y^2 ) and the O 2p bands projected from a
+hybrid bonding state, leading to an increase of the density of states at the
+Fermi level, in agreement with our density functional theory calculations.
+Similar Tc-P behavior has also been reported in the trilayer
+Br2Sr2Ca2Cu3O10+{\delta} (Bi2223). These observations suggest that higher Tcs
+than those previously reported for the layered cuprate high temperature
+superconductors can be achieved by breaking away from the universal Tc-P
+relation through the application of higher pressures.",1901.10404v1
+2020-04-13,Discrimination of Internal Faults and Other Transients in an Interconnected System with Power Transformers and Phase Angle Regulators,"This study solves the problem of accurate detection of internal faults and
+classification of transients in a 5-bus interconnected system for Phase Angle
+Regulators (PAR) and Power Transformers. The analysis prevents mal-operation of
+differential relays in case of transients other than faults which include
+magnetizing inrush, sympathetic inrush, external faults with CT saturation,
+capacitor switching, non-linear load switching, and ferroresonance. A gradient
+boosting classifier (GBC) is used to distinguish the internal faults from the
+transient disturbances based on 1.5 cycles of 3-phase differential currents
+registered by a change detector. After the detection of an internal fault, GBCs
+are used to locate the faulty unit (Power Transformer, PAR series, or exciting
+unit) and identify the type of fault. In case a transient disturbance is
+detected, another GBC classifies them into the six transient disturbances. Five
+most relevant frequency and time domain features obtained using Information
+Gain are used to train and test the classifiers. The proposed algorithm
+distinguishes the internal faults from the other transients with a balanced
+accuracy of 99.95%. The faulty transformer unit is located with a balanced
+accuracy of 99.5% and the different transient disturbances are identified with
+a balanced accuracy of 99.3%. Moreover, the reliability of the scheme is
+verified for different rating and connection of the transformers involved, CT
+saturation, and noise levels in the signals. These GBC classifiers can work
+together with a conventional differential relay and offer a supervisory control
+over its operation. PSCAD/EMTDC software is used for simulation of the
+transients and to develop the two and three-winding transformer models for
+creating the internal faults including inter-turn and inter-winding faults.",2004.06003v2
+2020-07-31,Magnetohydrodynamics of protoplanetary discs,"Protoplanetary discs are made of gas and dust orbiting a young star. They are
+also the birth place of planetary systems, which motivates a large amount of
+observational and theoretical research.
+  In these lecture notes, I present a review of the magnetic mechanisms applied
+to the outer regions R>1 AU of these discs, which are the planet-formation
+regions. In contrast to usual astrophysical plasmas, the gas in these regions
+is noticeably cold (T<300 K) and dense, which implies a very low ionisation
+fraction close to the disc midplane. In these notes, I deliberately ignore the
+innermost R~0.1 AU region which is influenced by the star-disk interaction and
+various radiative effects.
+  I start by presenting a short overview of the observational evidence for the
+dynamics of these objects. I then introduce the methods and approximations used
+to model these plasmas, including non-ideal MHD, and the uncertainties
+associated with this approach. In this framework, I explain how the global
+dynamics of these discs is modelled, and I present a stability analysis of this
+plasma in the local approximation, introducing the non-ideal magneto-rotational
+instability. Following this mostly analytical part, I discuss numerical models
+which have been used to describe the saturation mechanisms of this instability,
+and the formation of large-scale structures by various saturation mechanisms.
+Finally, I show that local numerical models are insufficient since magnetised
+winds are also emitted from the surface of these objects. After a short
+introduction on winds physics, I present global models of protoplanetary discs,
+including both a large-scale wind and the non-ideal dynamics of the disc.",2007.15967v1
+2020-10-13,Hydrodynamical simulations of protoplanetary disks including irradiation of stellar photons. I. Resolution study for Vertical Shear Instability (VSI),"In recent years hydrodynamical (HD) models have become important to describe
+the gas kinematics in protoplanetary disks, especially in combination with
+models of photoevaporation and/or magnetic-driven winds. We focus on diagnosing
+the the vertical extent of the VSI at 203 cells per scale height and allude at
+what resolution per scale height we obtain convergence. Finally, we determine
+the regions where EUV, FUV and X-Rays are dominant in the disk. We perform
+global HD simulations using the PLUTO code. We adopt a global isothermal
+accretion disk setup, 2.5D (2 dimensions, 3 components) which covers a radial
+domain from 0.5 to 5.0 and an approximately full meridional extension. We
+determine the 50 cells per scale height to be the lower limit to resolve the
+VSI. For higher resolutions, greater than 50 cells per scale height, we observe
+the convergence for the saturation level of the kinetic energy. We are also
+able to identify the growth of the `body' modes, with higher growth rate for
+higher resolution. Full energy saturation and a turbulent steady state is
+reached after 70 local orbits. We determine the location of the EUV-heated
+region defined by the radial column density to be 10$^{19}$ cm$^{-2}$ located
+at $H_\mathrm{R}\sim9.7$, and the FUV/X-Rays-heated boundary layer defined by
+10$^{22}$ cm$^{-2}$ located at $H_\mathrm{R}\sim6.2$, making it necessary to
+introduce the need of a hot atmosphere. For the first time, we report the
+presence of small scale vortices in the r-Z plane, between the characteristic
+layers of large scale vertical velocity motions. Such vortices could lead to
+dust concentration, promoting grain growth. Our results highlight the
+importance to combine photoevaporation processes in the future high-resolution
+studies of the turbulence and accretion processes in disks.",2010.06711v1
+2021-04-11,"The effects of non-helical component of hypermagnetic field on the evolution of the matter-antimatter asymmetry, vorticity, and hypermagnetic field","We study the evolution of the matter-antimatter asymmetry ({\eta}), the
+vorticity, and the hypermagnetic field in the symmetric phase of the early
+Universe, and in the temperature range 100 GeV < T < 10 TeV. We assume a
+configuration for the hypermagnetic field which includes both helical and
+non-helical (Bz) components. Consequently, the hypermagnetic field and the
+fluid vorticity can directly affect each other, the manifestations of which we
+explore in three scenarios. In the first scenario, we show that in the presence
+of a small vorticity and a large {\eta}eR, helicity can be generated and
+amplified for an initially strong Bz. The generation of the helical seed is due
+to the chiral vortical effect (CVE) and/or the advection term, while its growth
+is mainly due to the chiral magnetic effect (CME) which leads to the production
+of the baryon asymmetry, as well. The vorticity saturates to a nonzero value
+which depends on Bz, even in the presence of the viscosity, due to the
+back-reaction of Bz on the plasma. Increasing the initial vorticity, makes the
+values of the helicity, {\eta}s, and vorticity reach their saturation curves
+sooner, but does not change their final values at the onset of the electroweak
+phase transition. The second scenario is similar to the first except we assume
+that all initial {\eta}s are zero. We find that much higher initial vorticity
+is required for the generation process. In the third scenario, we show that in
+the presence of only a strong hypermagnetic field, {\eta}s and vorticity can be
+generated and amplified. Increasing the initial helicity, increases the final
+{\eta}s and vorticity. We find that although the presence of a nonzero initial
+Bz is necessary in all three scenarios, its increase only increases the final
+values of vorticity.",2104.05013v1
+2022-08-10,"Starspots, chromospheric emission lines, and flares of zero-age main-sequence stars","Zero-age main-sequence (ZAMS) stars are considered to have enormous starspots
+and show strong chromospheric emission lines because of their strong surface
+magnetic field. We discuss the dynamo activities of ZAMS stars with respect to
+their periodic light variation caused by a starspot and with respect to the
+strength of the chromospheric emission lines. The light curves of $33$ ZAMS
+stars in IC 2391 and IC 2602 were obtained from \textit{TESS} photometric data.
+The light curves can be grouped into the following four categories: single
+frequency, possible shape changer, beater, and complex variability. The
+amplitudes of the light curves are $0.001-0.145\,\mathrm{mag}$, similar to
+those of ZAMS stars in Pleiades. The starspot coverages are $0.1-21\%$. We
+found that the light variations and Ca\,\emissiontype{II} emission line
+strength of ZAMS stars in IC 2391, IC 2602, and the Pleiades cluster are as
+large as those of the most active superflare stars and two orders larger than
+those of the Sun, and are located on the extensions of the superflare stars.
+These results suggest that superflare stars link the properties of the Sun to
+those of the ZAMS stars of ages between $30$ and $120\,\mathrm{Myr}$. ZAMS
+stars with a single frequency or possible shape change in the light curve tend
+to have both large light variation, indicating large spot coverage, and
+saturated Ca\,\emissiontype{II} emission line strength. ZAMS stars with beat or
+complex variability have small spot coverage and a faint Ca\,\emissiontype{II}
+emission line. We also detected $21$ flares in the \textit{TESS} light curves
+of $12$ ZAMS stars in IC 2391 and IC 2602, where most of these stars have
+saturated chromospheric Ca\,\emissiontype{II} emission lines. The energies of
+the flares are estimated to be $\sim 10^{33}-10^{35}\,\mathrm{erg}$, which is
+comparable with the energy of a superflare.",2208.05175v2
+2023-04-27,Heisenberg Limit beyond Quantum Fisher Information,"The Heisenberg limit provides a fundamental bound on the achievable
+estimation precision with a limited number of $N$ resources used (e.g., atoms,
+photons, etc.). Using entangled quantum states makes it possible to scale the
+precision with $N$ better than when resources would be used independently.
+Consequently, the optimal use of all resources involves accumulating them in a
+single execution of the experiment. Unfortunately, that implies that the most
+common theoretical tool used to analyze metrological protocols - quantum Fisher
+information (QFI) - does not allow for a reliable description of this problem,
+as it becomes operationally meaningful only with multiple repetitions of the
+experiment. In this thesis, using the formalism of Bayesian estimation and the
+minimax estimator, I derive asymptotically saturable bounds on the precision of
+the estimation for the case of noiseless unitary evolution. For the case where
+the number of resources $N$ is strictly constrained, I show that the final
+measurement uncertainty is $\pi$ times larger than would be implied by a naive
+use of QFI. I also analyze the case where a constraint is imposed only on the
+average amount of resources, the exact value of which may fluctuate (in which
+case QFI does not provide any universal bound for precision). In both cases, I
+study the asymptotic saturability and the rate of convergence of these bounds.
+In the following part, I analyze the problem of the Heisenberg limit when
+multiple parameters are measured simultaneously on the same physical system. In
+particular, I investigate the existence of a gain from measuring all parameters
+simultaneously compared to distributing the same amount of resources to measure
+them independently. I focus on two examples - the measurement of multiple phase
+shifts in a multi-arm interferometer and the measurement of three magnetic
+field components.",2304.14370v1
+2005-12-20,Integrable models and quantum spin ladders: comparison between theory and experiment for the strong coupling ladder compounds,"(abbreviated) This article considers recent advances in the investigation of
+the thermal and magnetic properties of integrable spin ladder models and their
+applicability to the physics of real compounds. The ground state properties of
+the integrable two-leg spin-1/2 and the mixed spin-(1/2,1) ladder models at
+zero temperature are analyzed by means of the Thermodynamic Bethe Ansatz.
+Solving the TBA equations yields exact results for the critical fields and
+critical behaviour. The thermal and magnetic properties of the models are
+investigated in terms of the recently introduced High Temperature Expansion
+method, which is discussed in detail. It is shown that in the strong coupling
+limit the integrable spin-1/2 ladder model exhibits three quantum phases: (i) a
+gapped phase in the regime $H<H_{c1}$, (ii) a fully polarised phase for
+$H>H_{c2}$, and (iii) a Luttinger liquid magnetic phase in the regime
+$H_{c1}<H<H_{c2}$. The critical behaviour in the vicinity of the critical
+points is of the Pokrovsky-Talapov type. The temperature-dependent thermal and
+magnetic properties are directly evaluated from the exact free energy
+expression and compared to known experimental results for a range of strong
+coupling ladder compounds. Similar analysis of the mixed spin-(1/2,1) ladder
+model reveals a rich phase diagram, with a 1/3 and a full saturation
+magnetisation plateau within the strong antiferromagnetic rung coupling regime.
+For weak rung coupling, the fractional magnetisation plateau is diminished and
+a new quantum phase transition occurs. The phase diagram can be directly
+deduced from the magnetisation curve obtained from the exact result derived
+from the HTE. The thermodynamics of the spin-orbital model with different
+single-ion anisotropies is also investigated.",0512489v3
+2006-05-19,"Magnetic state dynamics in itinerant paramagnet UM3B2 (M= Co, Ir) probed by 11B NMR","We have carried out the $^{11}$B NMR measurement on the itinerant
+paramagnetic systems U$M_{3}$B$_{2}$ ($M =$ Co, Ir) to investigate the
+low-dimensional characteristics of the $5f$-electrons due to the structural
+anisotropy. The recent X-ray analysis suggests that UIr$_3$B$_2$ has a
+different structure modulated from the ever-known superlattice. The azimuth
+angle variation of NMR spectrum within the $ab$-plane clarified that B atoms
+occupy the single site, and a certain ligands arrangement surrounding B atom
+turns to the same orientation as the another one through the three- or six-fold
+rotation around the c-axis. These results have been consistent with the X-ray
+proposition. To evaluate the temperature ($T$) development of general
+susceptibility ($\chi_{q,\omega}$), Knight shift and nuclear spin-lattice
+relaxation rates measurements were performed and the similar variations of
+$\chi_{q,\omega}$ were identified in both UCo$_{3}$B$_{2}$ and
+UIr$_{3}$B$_{2}$. Above a crossover point defined as $T^{*}\simeq50$ K, the
+evolution of $\chi_{q,\omega}$ is dominant at $q=0$, suggesting that
+ferromagnetic correlations develop in high-$T$ regimes; meanwhile, below
+$T^{*}$, the $q=0$ part in $\chi_{q,\omega}$ shows the saturation tendency, and
+a different class of dispersion at finite-$q$ suddenly emerges. This particular
+magnetic correlations are interpreted as the antiferromagnetic correlations,
+and notable feature of the magnetic state dynamics in low-$T$ regimes is that
+the antiferromagnetic correlations arise together with the ferromagnetic
+component at the same time. The unique magnetic correlations obtained from NMR
+experiment will be discussed by the possible low-dimensionality of
+U$M_{3}$B$_{2}$ lattice.",0605483v1
+2006-10-05,Fundamental Magnetic Properties and Structural Implications for Nanocrystalline Fe-Ti-N Thin Films,"The magnetization (M) as a function of temperature (T) from 2 to 300 K and
+in-plane field (H) up to 1 kOe, room temperature easy and hard direction
+in-plane field hysteresis loops for fields between -100 and +100 Oe, and 10 GHz
+ferromagnetic resonance (FMR) profiles have been measured for a series of
+soft-magnetic nano-crystalline 50 nm thick Fe-Ti-N films made by magnetron
+sputtering in an in-plane field. The nominal titanium concentration was 3 at. %
+and the nitrogen concentrations (xN) ranged from zero to 12.7 at. %. The
+saturation magnetization (Ms) vs. T data and the extracted exchange parameters
+as a function of xN are consistent with a lattice expansion due to the addition
+of interstitial nitrogen in the body-centered-cubic (bcc) lattice and a
+structural transition to body-centered-tetragonal (bct) in the 6-8 at. %
+nitrogen range. The hysteresis loop and FMR data show a consistent picture of
+the changes in both the uniaxial and cubic anisotropy as a function of xN.
+Films with xN > 1.9 at. % show an overall uniaxial anisotropy, with an
+anisotropy field parameter Hu that increases with xN. The corresponding
+dispersion averaged uniaxial anisotropy energy density parameter <Ku> = HuMs/2
+is a linear function of xN, with a rate of increase of 950 erg/cm3 per at. %
+nitrogen. The estimated uniaxial anisotropy energy per nitrogen atom is 30
+J/mol, a value consistent with other systems. For xN below 6 at. %, the scaling
+of coercive force Hc data with the sixth power of the grain size D indicate a
+grain averaged effective cubic anisotropy energy density parameter <K1> that is
+about an order of magnitude smaller that the nominal K1 values for iron, and
+give a quantitative <K1> vs. D response that matches predictions for exchange
+coupled random grains with cubic anisotropy.",0610160v1
+2002-06-01,The r-modes in accreting neutron stars with magneto-viscous boundary layers,"We explore the dynamics of the r-modes in accreting neutron stars in two
+ways. First, we explore how dissipation in the magneto-viscous boundary layer
+(MVBL) at the crust-core interface governs the damping of r-mode perturbations
+in the fluid interior. Two models are considered: one assuming an
+ordinary-fluid interior, the other taking the core to consist of superfluid
+neutrons, type II superconducting protons, and normal electrons. We show,
+within our approximations, that no solution to the magnetohydrodynamic
+equations exists in the superfluid model when both the neutron and proton
+vortices are pinned. However, if just one species of vortex is pinned, we can
+find solutions. When the neutron vortices are pinned and the proton vortices
+are unpinned there is much more dissipation than in the ordinary-fluid model,
+unless the pinning is weak. When the proton vortices are pinned and the neutron
+vortices are unpinned the dissipation is comparable or slightly less than that
+for the ordinary-fluid model, even when the pinning is strong. We also find in
+the superfluid model that relatively weak radial magnetic fields ~ 10^9 G (10^8
+K / T)^2 greatly affect the MVBL, though the effects of mutual friction tend to
+counteract the magnetic effects. Second, we evolve our two models in time,
+accounting for accretion, and explore how the magnetic field strength, the
+r-mode saturation amplitude, and the accretion rate affect the cyclic evolution
+of these stars. If the r-modes control the spin cycles of accreting neutron
+stars we find that magnetic fields can affect the clustering of the spin
+frequencies of low mass x-ray binaries (LMXBs) and the fraction of these that
+are currently emitting gravitational waves.",0206001v2
+1994-12-22,String Solitons,"We review the status of solitons in superstring theory, with a view to
+understanding the strong coupling regime. These {\it solitonic} solutions are
+non-singular field configurations which solve the empty-space low-energy field
+equations (generalized, whenever possible, to all orders in $\alpha'$), carry a
+non-vanishing topological ""magnetic"" charge and are stabilized by a topological
+conservation law. They are compared and contrasted with the {\it elementary}
+solutions which are singular solutions of the field equations with a
+$\sigma$-model source term and carry a non-vanishing Noether ""electric"" charge.
+In both cases, the solutions of most interest are those which preserve half the
+spacetime supersymmetries and saturate a Bogomol'nyi bound. They typically
+arise as the extreme mass=charge limit of more general two-parameter solutions
+with event horizons. We also describe the theory {\it dual} to the fundamental
+string for which the roles of elementary and soliton solutions are
+interchanged. In ten spacetime dimensions, this dual theory is a superfivebrane
+and this gives rise to a string/fivebrane duality conjecture according to which
+the fivebrane may be regarded as fundamental in its own right, with the
+strongly coupled string corresponding to the weakly coupled fivebrane and
+vice-versa. After compactification to four spacetime dimensions, the fivebrane
+appears as a magnetic monopole or a dual string according as it wraps around
+five or four of the compactified dimensions. This gives rise to a
+four-dimensional string/string duality conjecture which subsumes a
+Montonen-Olive type duality in that the magnetic monopoles of the fundamental
+string correspond to the electric winding states of the dual string. This leads
+to a {\it duality of dualities} whereby under string/string duality the the
+strong/weak coupling $S$-duality trades places with the minimum/maximum length
+$T$-duality. Since these magnetic monopoles are extreme black holes, a
+prediction of $S$-duality is that the corresponding electric massive states of
+the fundamental string are also extreme black holes.",9412184v1
+2007-05-24,MHD simulations of the magnetorotational instability in a shearing box with zero net flux. II. The effect of transport coefficients,"We study the influence of the choice of transport coefficients (viscosity and
+resistivity) on MHD turbulence driven by the magnetorotational instability
+(MRI) in accretion disks. We follow the methodology described in paper I: we
+adopt an unstratified shearing box model and focus on the case where the net
+vertical magnetic flux threading the box vanishes. For the most part we use the
+finite difference code ZEUS, including explicit transport coefficients in the
+calculations. However, we also compare our results with those obtained using
+other algorithms (NIRVANA, the PENCIL code and a spectral code) to demonstrate
+both the convergence of our results and their independence of the numerical
+scheme. We find that small scale dissipation affects the saturated state of MHD
+turbulence. In agreement with recent similar numerical simulations done in the
+presence of a net vertical magnetic flux, we find that turbulent activity
+(measured by the rate of angular momentum transport) is an increasing function
+of the magnetic Prandtl number Pm for all values of the Reynolds number Re that
+we investigated. We also found that turbulence disappears when the Prandtl
+number falls below a critical value Pm_c that is apparently a decreasing
+function of Re. For the limited region of parameter space that can be probed
+with current computational resources, we always obtained Pm_c>1. We conclude
+that the magnitudes of the transport coefficients are important in determining
+the properties of MHD turbulence in numerical simulations in the shearing box
+with zero net flux, at least for Reynolds numbers and magnetic Prandtl numbers
+that are such that transport is not dominated by numerical effects and thus can
+be probed using current computational resources.",0705.3622v2
+2007-09-24,Nonlinear Dynamics of the Parker Scenario for Coronal Heating,"The Parker or field line tangling model of coronal heating is studied
+comprehensively via long-time high-resolution simulations of the dynamics of a
+coronal loop in cartesian geometry within the framework of reduced
+magnetohydrodynamics (RMHD). Slow photospheric motions induce a Poynting flux
+which saturates by driving an anisotropic turbulent cascade dominated by
+magnetic energy. In physical space this corresponds to a magnetic topology
+where magnetic field lines are barely entangled, nevertheless current sheets
+(corresponding to the original tangential discontinuities hypothesized by
+Parker) are continuously formed and dissipated.
+  Current sheets are the result of the nonlinear cascade that transfers energy
+from the scale of convective motions ($\sim 1,000 km$) down to the dissipative
+scales, where it is finally converted to heat and/or particle acceleration.
+Current sheets constitute the dissipative structure of the system, and the
+associated magnetic reconnection gives rise to impulsive ``bursty'' heating
+events at the small scales. This picture is consistent with the slender loops
+observed by state-of-the-art (E)UV and X-ray imagers which, although apparently
+quiescent, shine bright in these wavelengths with little evidence of entangled
+features.
+  The different regimes of weak and strong MHD turbulence that develop, and
+their influence on coronal heating scalings, are shown to depend on the loop
+parameters, and this dependence is quantitatively characterized: weak
+turbulence regimes and steeper spectra occur in {\it stronger loop fields} and
+lead to {\it larger heating rates} than in weak field regions.",0709.3687v2
+2009-08-16,"Evolution of the bulk properties, structure, magnetic order, and superconductivity with Ni doping in CaFe2-xNixAs2","Magnetization, susceptibility, specific heat, resistivity, neutron and x-ray
+diffraction have been used to characterize the properties of single crystalline
+CaFe2-xNixAs2 as a function of Ni doping for x varying from 0 to 0.1. The
+combined first-order structural and magnetic phase transitions occur together
+in the undoped system at 172 K, with a small decrease in the area of the a-b
+plane along with an abrupt increase in the length of the c-axis in the
+orthorhombic phase. With increasing x the ordered moment and transition
+temperature decrease, but the transition remains sharp at modest doping while
+the area of the a-b plane quickly decreases and then saturates. Warming and
+cooling data in the resistivity and neutron diffraction indicate hysteresis of
+~2 K. At larger doping the transition is more rounded, and decreases to zero
+for x=0.06. The susceptibility is anisotropic for all values of x. Electrical
+resistivity for x = 0.053 and 0.06 shows a superconducting transition with an
+onset of nearly 15 K which is further corroborated by substantial diamagnetic
+susceptibility. For the fully superconducting sample there is no long range
+magnetic order and the structure remains tetragonal at all temperature, but
+there is an anomalous increase in the area of the a-b plane in going to low T.
+Heat capacity data show that the density of states at the Fermi level increases
+for x > 0.053 as inferred from the value of Sommerfeld coefficient. The regime
+of superconductivity is quite restrictive, with a maximum TC of 15 K and an
+upper critical field Hc2=14 T. Superconductivity disappears in the overdoped
+region.",0908.2255v2
+2010-11-02,The baroclinic instability in the context of layered accretion. Self-sustained vortices and their magnetic stability in local compressible unstratified models of protoplanetary disks,"Turbulence and angular momentum transport in accretion disks remains a topic
+of debate. With the realization that dead zones are robust features of
+protoplanetary disks, the search for hydrodynamical sources of turbulence
+continues. A possible source is the baroclinic instability (BI), which has been
+shown to exist in unmagnetized non-barotropic disks. We present shearing box
+simulations of baroclinicly unstable, magnetized, 3D disks, in order to assess
+the interplay between the BI and other instabilities, namely the
+magneto-rotational instability (MRI) and the magneto-elliptical instability. We
+find that the vortices generated and sustained by the baroclinic instability in
+the purely hydrodynamical regime do not survive when magnetic fields are
+included. The MRI by far supersedes the BI in growth rate and strength at
+saturation. The resulting turbulence is virtually identical to an MRI-only
+scenario. We measured the intrinsic vorticity profile of the vortex, finding
+little radial variation in the vortex core. Nevertheless, the core is disrupted
+by an MHD instability, which we identify with the magneto-elliptic instability.
+This instability has nearly the same range of unstable wavelengths as the MRI,
+but has higher growth rates. In fact, we identify the MRI as a limiting case of
+the magneto-elliptic instability, when the vortex aspect ratio tends to
+infinity (pure shear flow). We conclude that vortex excitation and
+self-sustenance by the baroclinic instability in protoplanetary disks is viable
+only in low ionization, i.e., the dead zone. Our results are thus in accordance
+with the layered accretion paradigm. A baroclinicly unstable dead zone should
+be characterized by the presence of large-scale vortices whose cores are
+elliptically unstable, yet sustained by the baroclinic feedback. As magnetic
+fields destroy the vortices and the MRI outweighs the BI, the active layers are
+unmodified.",1011.0497v3
+2011-04-27,Mass accretion to young stars triggered by flaring activity in circumstellar disks,"Young low-mass stars are characterized by ejection of collimated outflows and
+by circumstellar disks which they interact with through accretion of mass. The
+accretion builds up the star to its final mass and is also believed to power
+the mass outflows, which may in turn remove the excess angular momentum from
+the star-disk system. However, although the process of mass accretion is a
+critical aspect of star formation, some of its mechanisms are still to be fully
+understood. A point not considered to date and relevant for the accretion
+process is the evidence of very energetic and frequent flaring events in these
+stars. Flares may easily perturb the stability of the disks, thus influencing
+the transport of mass and angular momentum. Here we report on three-dimensional
+magnetohydrodynamic modeling of the evolution of a flare with an idealized
+non--equilibrium initial condition occurring near the disk around a rotating
+magnetized star. The model takes into account the stellar magnetic field, the
+gravitational force, the viscosity of the disk, the magnetic-field-oriented
+thermal conduction (including the effects of heat flux saturation), the
+radiative losses from optically thin plasma, and the coronal heating. We show
+that, during its first stage of evolution, the flare gives rise to a hot
+magnetic loop linking the disk to the star. The disk is strongly perturbed by
+the flare: disk material evaporates under the effect of the thermal conduction
+and an overpressure wave propagates through the disk. When the overpressure
+reaches the opposite side of the disk, a funnel flow starts to develop there,
+accreting substantial disk material onto the young star from the side of the
+disk opposite to the flare.",1104.5107v1
+2011-08-31,Gyrokinetic Equations for Strong-Gradient Regions,"A gyrokinetic theory is developed under a set of orderings applicable to the
+edge region of tokamaks and other magnetic confinement devices, as well as to
+internal transport barriers. The result is a practical set equations that is
+valid for large perturbation amplitudes [q{\delta}{\psi}/T = O(1), where
+{\delta}{\psi} = {\delta}{\phi} - v_par {\delta}A_par/c], which is
+straightforward to implement numerically, and which has straightforward
+expressions for its conservation properties. Here, q is the particle charge,
+{\delta}{\phi} and {\delta}A_par are the perturbed electrostatic and parallel
+magnetic potentials, v_par is the parallel velocity, c is the speed of light,
+and T is the temperature. The derivation is based on the quantity
+{\epsilon}:=({\rho}/{\lambda})q{\delta}{\psi}/T << 1 as the small expansion
+parameter, where {\rho} is the gyroradius and {\lambda} is the perpendicular
+wavelength. Physically, this ordering requires that the E\times B velocity and
+the component of the parallel velocity perpendicular to the equilibrium
+magnetic field are small compared to the thermal velocity. For nonlinear
+fluctuations saturated at ""mixing-length"" levels (i.e., at a level such that
+driving gradients in profile quantities are locally flattened), {\epsilon} is
+of order {\rho}/L, where L is the equilibrium profile scale length, for all
+scales {\lambda} ranging from {\rho} to L. This is true even though
+q{\delta}{\psi}/T = O(1) for {\lambda} ~ L. Significant additional
+simplifications result from ordering L/R =O({\epsilon}), where R is the spatial
+scale of variation of the magnetic field. We argue that these orderings are
+well satisfied in strong-gradient regions, such as edge and screapeoff layer
+regions and internal transport barriers in tokamaks, and anticipate that our
+equations will be useful as a basis for simulation models for these regions.",1108.6327v2
+2011-09-01,The Elemental Shear Dynamo,"A quasi-linear theory is presented for how randomly forced, barotropic
+velocity fluctuations cause an exponentially-growing, large-scale (mean)
+magnetic dynamo in the presence of a uniform shear flow, $\vec{U} = S x
+\vec{e}_y$. It is a ""kinematic"" theory for the growth of the mean magnetic
+energy from a small initial seed, neglecting the saturation effects of the
+Lorentz force. The quasi-linear approximation is most broadly justifiable by
+its correspondence with computational solutions of nonlinear
+magneto-hydrodynamics, and it is rigorously derived in the limit of large
+resistivity, $\eta \rightarrow \infty$. Dynamo action occurs even without mean
+helicity in the forcing or flow, but random helicity variance is then
+essential. In a sufficiently large domain and with small wavenumber $k_z$ in
+the direction perpendicular to the mean shearing plane, a positive exponential
+growth rate $\gamma$ can occur for arbitrary values of $\eta$, the viscosity
+$\nu$, and the random-forcing correlation time $t_f$ and phase angle $\theta_f$
+in the shearing plane. The value of $\gamma$ is independent of the domain size.
+The shear dynamo is ""fast"", with finite $\gamma > 0$ in the limit of $\eta
+\rightarrow 0$. Averaged over the random forcing ensemble, the mean magnetic
+field grows more slowly, if at all, compared to the r.m.s. field (or magnetic
+energy). In the limit of small Reynolds numbers ($\eta, \ \nu \rightarrow
+\infty$), the dynamo behavior is related to the well-known alpha--omega {\it
+ansatz} when the forcing is steady ($t_f \rightarrow \infty$) and to the
+""incoherent"" alpha--omega {\it ansatz} when the forcing is purely fluctuating.",1109.0289v2
+2011-09-29,Developing the Technique of Measurements of Magnetic Field in the CMS Steel Yoke Elements With Flux-Loops and Hall Probes,"Compact muon solenoid (CMS) is a general-purpose detector designed to run at
+the highest luminosity at the CERN large hadron collider (LHC). Its distinctive
+features include a 4 T superconducting solenoid with 6 m diameter by 12.5 m
+long free bore, enclosed inside a 10000-ton return yoke made of construction
+steel. Accurate characterization of the magnetic field everywhere in
+theCMSdetector, including the large ferromagnetic parts of the yoke, is
+required. To measure the field in and around ferromagnetic parts, a set of
+flux-loops and Hall probe sensors will be installed on several of the steel
+pieces. Fast discharges of the solenoid during system commissioning tests will
+be used to induce voltages in the flux-loops that can be integrated to measure
+the flux in the steel at full excitation of the solenoid. The Hall sensors will
+give supplementary information on the axial magnetic field and permit
+estimation of the remanent field in the steel after the fast discharge. An
+experimental R&D program has been undertaken, using a test flux-loop, two Hall
+sensors, and sample disks made from the same construction steel used for the
+CMS magnet yoke. A sample disc, assembled with the test flux-loop and the Hall
+sensors, was inserted between the pole tips of a dipole electromagnet equipped
+with a computer-controlled power supply to measure the excitation of the steel
+from full saturation to zero field. The results of the measurements are
+presented and discussed.",1109.6465v1
+2011-10-21,Magnetic properties and revisited exchange integrals of the frustrated chain cuprate PbCuSO$_4$(OH)$_2$ - linarite,"We present a detailed study in the paramagnetic regime of the frustrated $s$
+= 1/2 spin-compound linarite, PbCuSO$_4$(OH)$_2$, with competing ferromagnetic
+nearest-neighbor and antiferromagnetic next-nearest-neighbor exchange
+interactions. Our data reveal highly anisotropic values for the saturation
+field along the crystallographic main directions, with $\sim$ 7.6, $\sim$ 10.5
+and $\sim$ 8.5\,T for the $a$, $b$, and $c$ axes, respectively. In the
+paramagnetic regime, this behavior is explained mainly by the anisotropy of the
+\textit{g}-factor but leaving room for an easy-axis exchange anisotropy. Within
+the isotropic $J_1$-$J_2$ spin model our experimental data are described by
+various theoretical approaches yielding values for the exchange interactions
+$J_1$ $\sim$ -100\,K and $J_2$ $\sim$ 36\,K. These main intrachain exchange
+integrals are significantly larger as compared to the values derived in two
+previous studies in the literature and shift the frustration ratio $\alpha =
+J_2/|J_1|$ $\approx$ 0.36 of linarite closer to the 1D critical point at 0.25.
+Electron spin resonance (ESR) and nuclear magnetic resonance (NMR) measurements
+further prove that the static susceptibility is dominated by the intrinsic spin
+susceptibility. The Knight shift as well as the broadening of the linewidth in
+ESR and NMR at elevated temperatures indicate a highly frustrated system with
+the onset of magnetic correlations far above the magnetic ordering temperature
+$T_\mathrm{N}$ = 2.75(5)\,K, in agreement with the calculated exchange
+constants.",1110.4729v1
+2012-02-14,Dephasing and Hyperfine Interaction in Carbon Nanotubes Double Quantum Dots: Disordered Case,"We study theoretically the \emph{return probability experiment}, used to
+measure the dephasing time $T_2^*$, in a double quantum dot (DQD) in
+semiconducting carbon nanotubes (CNTs) with spin-orbit coupling and disorder
+induced valley mixing. Dephasing is due to hyperfine interaction with the spins
+of the ${}^{13}$C nuclei. Due to the valley and spin degrees of freedom four
+bounded states exist for any given longitudinal mode in the quantum dot. At
+zero magnetic field the spin-orbit coupling and the valley mixing split those
+four states into two Kramers doublets. The valley mixing term for a given dot
+is determined by the intra-dot disorder and therefore the states in the Kramers
+doublets belonging to different dots are different. We show how nonzero
+single-particle interdot tunneling amplitudes between states belonging to
+different doublets give rise to new avoided crossings, as a function of
+detuning, in the relevant two particle spectrum, crossing over from the two
+electrons in one dot states configuration, $(0,2)$, to the one electron in each
+dot configuration, $(1,1)$. In contrast to the clean system, multiple
+Landau-Zener processes affect the separation and the joining stages of each
+single-shot measurement and they affect the outcome of the measurement in a way
+that strongly depends on the initial state. We find that a well-defined return
+probability experiment is realized when, at each single-shot cycle, the (0,2)
+ground state is prepared. In this case, valley mixing increases the saturation
+value of the measured return probability, whereas the probability to return to
+the (0,2) ground state remains unchanged. Finally, we study the effect of the
+valley mixing in the high magnetic field limit; for a parallel magnetic field
+the predictions coincide with a clean nanotube, while the disorder effect is
+always relevant with a magnetic field perpendicular to the nanotube axis.",1202.2929v2
+2012-02-16,Solitary magnetic perturbations at the ELM onset,"Edge localised modes (ELMs) allow maintaining sufficient purity of tokamak
+H-mode plasmas and thus enable stationary H-mode. On the other hand in a future
+device ELMs may cause divertor power flux densities far in excess of tolerable
+material limits. The size of the energy loss per ELM is determined by
+saturation effects in the non-linear phase of the ELM, which at present is
+hardly understood. Solitary magnetic perturbations (SMPs) are identified as
+dominant features in the radial magnetic fluctuations below 100kHz. They are
+typically observed close (+-0.1ms) to the onset of pedestal erosion. SMPs are
+field aligned structures rotating in the electron diamagnetic drift direction
+with perpendicular velocities of about 10km/s. A comparison of perpendicular
+velocities suggests that the perturbation evoking SMPs is located at or inside
+the separatrix. Analysis of very pronounced examples showed that the number of
+peaks per toroidal turn is 1 or 2, which is clearly lower than corresponding
+numbers in linear stability calculations. In combination with strong peaking of
+the magnetic signals this results in a solitary appearance resembling modes
+like palm tree modes, edge snakes or outer modes. This behavior has been
+quantified as solitariness and correlated to main plasma parameters. SMPs may
+be considered as a signature of the non-linear ELM-phase originating at the
+separatrix or further inside. Thus they provide a handle to investigate the
+transition from linear to non-linear ELM phase. By comparison with data from
+gas puff imaging processes in the non-linear phase at or inside the separatrix
+and in the scrape-off-layer (SOL) can be correlated. A connection between the
+passing of an SMP and the onset of radial filament propagation has been found.
+Eventually the findings related to SMPs may contribute to a future quantitative
+understanding of the non-linear ELM evolution.",1202.3603v1
+2012-03-01,Emergent Mesoscale Phenomena in Magnetized Accretion Disc Turbulence,"We study how the structure and variability of magnetohydrodynamic (MHD)
+turbulence in accretion discs converge with domain size. Our results are based
+on a series of vertically stratified local simulations, computed using the
+Athena code, that have fixed spatial resolution, but varying radial and
+azimuthal extent (from \Delta R = 0.5H to 16H, where H is the vertical scale
+height). We show that elementary local diagnostics of the turbulence, including
+the Shakura-Sunyaev {\alpha} parameter, the ratio of Maxwell stress to magnetic
+energy, and the ratio of magnetic to fluid stresses, converge to within the
+precision of our measurements for spatial domains of radial size Lx \geq 2H. We
+obtain {\alpha} = 0.02-0.03, consistent with recent results. Very small domains
+(Lx = 0.5H) return anomalous results, independent of spatial resolution. The
+convergence with domain size is only valid for a limited set of diagnostics:
+larger spatial domains admit the emergence of dynamically important mesoscale
+structures. In our largest simulations, the Maxwell stress shows a significant
+large scale non-local component, while the density develops long-lived
+axisymmetric perturbations (zonal flows) at the 20% level. Most strikingly, the
+variability of the disc in fixed-sized patches decreases strongly as the
+simulation volume increases. We find generally good agreement between our
+largest local simulations and global simulations with comparable spatial
+resolution. There is no direct evidence that the presence of curvature terms or
+radial gradients in global calculations materially affect the turbulence,
+except to perhaps introduce an outer radial scale for mesoscale structures. The
+demonstrated importance of mean magnetic fields, seen in both large local and
+global simulations implies that the growth and saturation of these fields is
+likely of critical importance for the evolution of accretion discs. (abridged)",1203.0314v1
+2013-10-24,Trends in Ultracool Dwarf Magnetism. I. X-Ray Suppression and Radio Enhancement,"Although ultracool dwarfs (UCDs) are now known to generate and dissipate
+strong magnetic fields, a clear understanding of the underlying dynamo is still
+lacking. We have performed X-ray and radio observations of seven UCDs in a
+narrow range of spectral type (M6.5-M9.5) but spanning a wide range of
+projected rotational velocities (v sin i ~ 3-40 km/s). We have also analyzed
+unpublished archival Chandra observations of four additional objects. All of
+the newly-observed targets are detected in the X-ray, while only one is
+detected in the radio, with the remainder having sensitive upper limits. We
+present a database of UCDs with both radio and X-ray measurements and consider
+the data in light of the so-called G\""udel-Benz relation (GBR) between magnetic
+activity in these bands. Some UCDs have very bright radio emission and faint
+X-ray emission compared to what would be expected for rapid rotators, while
+others show opposite behavior. We show that UCDs would still be
+radio-over-luminous relative to the GBR even if their X-ray emission were at
+standard rapid-rotator ""saturation"" levels. Recent results from Zeeman-Doppler
+imaging and geodynamo simulations suggest that rapidly-rotating UCDs may harbor
+a bistable dynamo that supports either a stronger, axisymmetric magnetic field
+or a weaker, non-axisymmetric field. We suggest that the data can be explained
+in a scenario in which strong-field objects obey the GBR while weak-field
+objects are radio-over-luminous and X-ray-under-luminous, possibly because of a
+population of gyrosynchrotron-emitting coronal electrons that is continuously
+replenished by low-energy reconnection events.",1310.6757v2
+2014-01-05,Soft X-ray emission in kink-unstable coronal loops,"Solar flares are associated with intense soft X-ray emission generated by the
+hot flaring plasma. Kink unstable twisted flux-ropes provide a source of
+magnetic energy which can be released impulsively and account for the flare
+plasma heating. We compute the temporal evolution of the thermal X-ray emission
+in kink-unstable coronal loops using MHD simulations and discuss the results of
+with respect to solar flare observations. The model consists of a highly
+twisted loop embedded in a region of uniform and untwisted coronal magnetic
+field. We let the kink instability develop, compute the evolution of the plasma
+properties in the loop (density, temperature) without accounting for mass
+exchange with the chromosphere. We then deduce the X-ray emission properties of
+the plasma during the whole flaring episode. During the initial phase of the
+instability plasma heating is mostly adiabatic. Ohmic diffusion takes over as
+the instability saturates, leading to strong and impulsive heating (> 20 MK),
+to a quick enhancement of X-ray emission and to the hardening of the thermal
+X-ray spectrum. The temperature distribution of the plasma becomes broad, with
+the emission measure depending strongly on temperature. Significant emission
+measures arise for plasma at temperatures T > 9 MK. The magnetic flux-rope then
+relaxes progressively towards a lower energy state as it reconnects with the
+background flux. The loop plasma suffers smaller sporadic heating events but
+cools down conductively. The total thermal X-ray emission slowly fades away
+during this phase, and the high temperature component of emission measure
+distribution converges to the power-law distribution $EM\propto T^{-4.2}$. The
+amount of twist deduced directly from the X-ray emission patterns is
+considerably lower than the maximum magnetic twist in the simulated flux-ropes.",1401.0916v2
+2014-02-25,"Structural, magnetic and superconducting properties of pulsed-laser-deposition-grown $\rm{La_{1.85}Sr_{0.15}CuO_{4}/La_{2/3}Ca_{1/3}MnO_{3}}$ superlattices on $\rm{(001)}$-oriented $\rm{LaSrAlO_{4}}$ substrates","Epitaxial La1.85Sr0.15CuO4/La2/3Ca1/3MnO3 superlattices on (001)-oriented
+LaSrAlO4 substrates have been grown with pulsed laser deposition technique.
+Their structural, magnetic and superconducting properties have been determined
+with in-situ reflection high energy electron diffraction, x-ray diffraction,
+specular neutron reflectometry, scanning transmission electron microscopy,
+electric transport, and magnetization measurements. We find that despite the
+large mismatch between the in-plane lattice parameters of LSCO and LCMO these
+superlattices can be grown epitaxially and with a high crystalline quality.
+While the first LSCO layer remains clamped to the LSAO substrate, a sizeable
+strain relaxation occurs already in the first LCMO layer. The following LSCO
+and LCMO layers adopt a nearly balanced state in which the tensile and
+compressive strain effects yield alternating in-plane lattice parameters with
+an almost constant average value. No major defects are observed in the LSCO
+layers, while a significant number of vertical antiphase boundaries are found
+in the LCMO layers. The LSCO layers remain superconducting with a relatively
+high superconducting onset temperature of about 36 K. The macroscopic
+superconducting response is also evident in the magnetization data due to a
+weak diamagnetic signal below 10 K for H || ab and a sizeable paramagnetic
+shift for H || c that can be explained in terms of a vortex-pinning-induced
+flux compression. The LCMO layers maintain a strongly ferromagnetic state with
+a Curie temperature of about 190 K and a large low-temperature saturation
+moment of about 3.5(1) muB. These results suggest that the LSCO/LCMO
+superlattices can be used to study the interaction between the antagonistic
+ferromagnetic and superconducting orders and, in combination with previous
+studies on YBCO/LCMO superlattices, may allow one to identify the relevant
+mechanisms.",1402.6258v1
+2014-06-09,Competition between superconductivity and magnetic/nematic order as a source of anisotropic superconducting gap in underdoped Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$,"The in-plane London penetration depth, $\Delta\lambda(T)$, was measured using
+a tunnel diode resonator technique in single crystals of
+Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$ with doping levels $x$ ranging from heavily
+underdoped, $x$=0.16 ($T_{c}$=7~K) to nearly optimally doped, $x$= 0.34
+($T_{c}=$39 K). Exponential saturation of $\Delta\lambda(T)$ in the $T\to0$
+limit is found in optimally doped samples, with the superfluid density
+$\rho_{s}(T)\equiv(\lambda(0)/\lambda(T))^{2}$ quantitatively described by a
+self-consistent $\gamma$-model with two nodeless isotropic superconducting
+gaps. As the doping level is decreased towards the extreme end of the
+superconducting dome at $x$=0.16, the low-temperature behavior of
+$\Delta\lambda(T)$ becomes non-exponential and best described by the power-law
+$\Delta\lambda(T)\propto T^{2}$, characteristic of strongly anisotropic gaps.
+The change between the two regimes happens within the range of coexisting
+magnetic/nematic order and superconductivity, $x<0.25$, and is accompanied by a
+rapid rise in the absolute value of $\Delta\lambda(T)$ with underdoping. This
+effect, characteristic of the competition between superconductivity and other
+ordered states, is very similar to but of significantly smaller magnitude than
+what is observed in the electron-doped Ba(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$
+compounds. Our study suggests that the competition between superconductivity
+and magnetic/nematic order in hole-doped compounds is weaker than in
+electron-doped compounds, and that the anisotropy of the superconducting state
+in the underdoped iron pnictides is a consequence of the anisotropic changes in
+the pairing interaction and in the gap function promoted by both magnetic and
+nematic long-range order.",1406.2369v1
+2014-09-29,Magnetotransport Measurements of the Surface States of Samarium Hexaboride using Corbino Structures,"The recent conjecture of a topologically-protected surface state in SmB$_6$
+and the verification of robust surface conduction below 4 K have prompted a
+large effort to understand the surface states. Conventional Hall transport
+measurements allow current to flow on all surfaces of a topological insulator,
+so such measurements are influenced by contributions from multiple surfaces of
+varying transport character. Instead, we study magnetotransport of SmB$_6$
+using a Corbino geometry, which can directly measure the conductivity of a
+single, independent surface. Both (011) and (001) crystal surfaces show a
+strong negative magnetoresistance at all magnetic field angles measured. The
+(011) surface has a carrier mobility of $122\text{
+cm}^2/\text{V}\cdot\text{sec}$ with a carrier density of $2.5\times10^{13}
+\text{ cm}^{-2}$, which are significantly smaller than indicated by Hall
+transport studies. This mobility value can explain a failure so far to observe
+Shubnikov-de Haas oscillations. Analysis of the angle-dependence of
+conductivity on the (011) surface suggests a combination of a field-dependent
+enhancement of the carrier density and a suppression of Kondo scattering from
+native oxide layer magnetic moments as the likely origin of the negative
+magnetoresistance. Our results also reveal a hysteretic behavior whose
+magnitude depends on the magnetic field sweep rate and temperature. Although
+this feature becomes smaller when the field sweep is slower, does not disappear
+or saturate during our slowest sweep-rate measurements, which is much slower
+than a typical magnetotransport trace. These observations cannot be explained
+by quantum interference corrections such as weak anti-localization, but are
+more likely due to an extrinsic magnetic effect such as the magnetocaloric
+effect or glassy ordering.",1409.8199v2
+2015-01-30,Steady mirror structures in a plasma with pressure anisotropy,"In the first part we present a review of our results concerning the weakly
+nonlinear regime of the mirror instability in the framework of an asymptotic
+model. This model belongs to the class of gradient type systems for which the
+free energy can only decrease in time. It reveals a behavior typical for
+subcritical bifurcations: below the mirror instability threshold, all localized
+stationary structures are unstable, while above threshold, the system displays
+a blow-up behavior. It is shown that taking the electrons into account
+(non-zero temperature) does not change the structure of the asymptotic model.
+For bi-Maxwellian distribution functions for both electrons and ions, the model
+predicts the formation of magnetic holes. The second part contains original
+results concerning two-dimensional steady mirror structures which can form in
+the saturated regime. Based on Grad-Shafranov-like equations, a gyrotropic
+plasma, where the pressures in the static regime are only functions of the
+amplitude of the local magnetic field, is shown to be amenable to a variational
+principle with a free energy density given by the parallel tension. This
+approach is used to demonstrate that small-amplitude static holes constructed
+slightly below the mirror instability threshold identify with lump solitons of
+KPII equation and turn out to be unstable. It is also shown that regularizing
+effects such as finite Larmor radius corrections cannot be ignored in the
+description of large-amplitude mirror structures. Using the gradient method,
+which is based on a variational principle for anisotropic MHD taking into
+account ion finite Larmor radius effects, we found both one-dimensional
+magnetic structures in the form of stripes and two-dimensional bubbles when the
+magnetic field component transverse to the plane is increased. These structures
+realize minimum of the free energy.",1501.07702v1
+2015-05-21,Angular momentum transport and large eddy simulations in magnetorotational turbulence: the small Pm limit,"Angular momentum transport in accretion discs is often believed to be due to
+magnetohydrodynamic turbulence mediated by the magnetorotational instability.
+Despite an abundant literature on the MRI, the parameters governing the
+saturation amplitude of the turbulence are poorly understood and the existence
+of an asymptotic behavior in the Ohmic diffusion regime is not clearly
+established. We investigate the properties of the turbulent state in the small
+magnetic Prandtl number limit. Since this is extremely computationally
+expensive, we also study the relevance and range of applicability of the most
+common subgrid scale models for this problem. Unstratified shearing boxes
+simulations are performed both in the compressible and incompressible limits,
+with a resolution up to 800 cells per disc scale height. The latter constitutes
+the largest resolution ever attained for a simulation of MRI turbulence. In the
+presence of a mean magnetic field threading the domain, angular momentum
+transport converges to a finite value in the small Pm limit. When the mean
+vertical field amplitude is such that {\beta}, the ratio between the thermal
+and magnetic pressure, equals 1000, we find {\alpha}~0.032 when Pm approaches
+zero. In the case of a mean toroidal field for which {\beta}=100, we find
+{\alpha}~0.018 in the same limit. Both implicit LES and Chollet-Lesieur closure
+model reproduces these results for the {\alpha} parameter and the power
+spectra. A reduction in computational cost of a factor at least 16 (and up to
+256) is achieved when using such methods. MRI turbulence operates efficiently
+in the small Pm limit provided there is a mean magnetic field. Implicit LES
+offers a practical and efficient mean of investigation of this regime but
+should be used with care, particularly in the case of a vertical field.
+Chollet-Lesieur closure model is perfectly suited for simulations done with a
+spectral code.",1505.05661v1
+2015-11-16,Electric quadrupole interaction in cubic BCC alpha-Fe,"Moessbauer transmission spectra for the 14.41-keV resonant line in 57Fe have
+been collected at room temperature by using 57Co(Rh) commercial source and
+alpha-Fe strain-free single crystal as an absorber. The absorber was magnetized
+to saturation in the absorber plane perpendicular to the gamma-ray beam axis
+applying small external magnetic field. Spectra were collected for various
+orientations of the magnetizing field, the latter lying close to the [110]
+crystal plane. A positive electric quadrupole coupling constant was found
+practically independent on the field orientation. One obtains the following
+value Vzz=+1.61(4)x10^19 V/m^2 for the (average) principal component of the
+electric field gradient (EFG) tensor under assumption that the EFG tensor is
+axially symmetric and the principal axis is aligned with the magnetic hyperfine
+field acting on the 57Fe nucleus. The nuclear spectroscopic electric quadrupole
+moment for the first excited state of the 57Fe nucleus was adopted as +0.17 b.
+Similar measurement was performed at room temperature using as-rolled
+polycrystalline alpha-Fe foil of high purity in the zero external field.
+Corresponding value for the principal component of the EFG was found as
+Vzz=+1.92(4)x10^19 V/m^2. Hence, it seems that the origin of the EFG is
+primarily due to the local (atomic) electronic wave function distortion caused
+by the spin-orbit interaction between effective electronic spin S and
+incompletely quenched electronic angular momentum L. It seems as well that the
+lowest order term proportional to the product L.LAMBDA.S dominates, as no
+direction dependence of the EFG principal component is seen. The lowest order
+term is isotropic for a cubic symmetry as one has LAMBDA=lambda.1 for cubic
+systems with the symbol 1 denoting unit operator and lambda being the coupling
+parameter.",1511.04933v4
+2015-11-18,On the electron dynamics during island coalescence in asymmetric magnetic reconnection,"We present an analysis of the electron dynamics during rapid island merging
+in asymmetric magnetic reconnection. We consider a doubly periodic system with
+two asymmetric transitions. The upper layer is an asymmetric Harris sheet
+initially perturbed to promote a single reconnection site. The lower layer is a
+tangential discontinuity that promotes the formation of many X-points,
+separated by rapidly merging islands. Across both layers the magnetic field and
+the density have a strong jump, but the pressure is held constant. Our analysis
+focuses on the consequences of electron energization during island coalescence.
+We focus first on the parallel and perpendicular components of the electron
+temperature to establish the presence of possible anisotropies and
+non-gyrotropies. Thanks to the direct comparison between the two different
+layers simulated, we can distinguish three main types of behavior
+characteristic of three different regions of interest. The first type
+represents the regions where traditional asymmetric reconnections take place
+without involving island merging. The second type of regions instead show
+reconnection events between two merging islands. Finally, the third regions
+identifies the regions between two diverging island and where typical signature
+of reconnection is not observed. Electrons in these latter regions additionally
+show a flat-top distribution resulting from the saturation of a two-stream
+instability generated by the two interacting electron beams from the two
+nearest reconnection points. Finally, the analysis of agyrotropy shows the
+presence of a distinct double structure laying all over the lower side facing
+the higher magnetic field region. The distinguishing features found for the
+three types of regions investigated provide clear indicators to the recently
+launched MMS NASA mission for investigating magnetopause reconnection involving
+multiple islands.",1511.05693v1
+2016-02-08,PIC Simulations of the Effect of Velocity Space Instabilities on Electron Viscosity and Thermal Conduction,"In low-collisionality plasmas, velocity-space instabilities are a key
+mechanism providing an effective collisionality for the plasma. We use
+particle-in-cell (PIC) simulations to study the interplay between electron and
+ion-scale velocity-space instabilities and their effect on electron pressure
+anisotropy, viscous heating, and thermal conduction. The adiabatic invariance
+of the magnetic moment in low-collisionality plasmas leads to pressure
+anisotropy, $p_{\perp,j} > p_{||,j}$, if the magnetic field $\vec{B}$ is
+amplified ($p_{\perp,j}$ and $p_{||,j}$ denote the pressure of species $j$
+[electron, ion] perpendicular and parallel to $\vec{B}$). If the resulting
+anisotropy is large enough, it can in turn trigger small-scale plasma
+instabilities. Our PIC simulations explore the nonlinear regime of the mirror,
+ion-cyclotron, and electron whistler instabilities, through continuous
+amplification of the magnetic field $|\vec{B}|$ by an imposed shear in the
+plasma. In the regime $1 \lesssim \beta_j \lesssim 20$ ($\beta_j \equiv 8\pi
+p_j/|\vec{B}|^2$), the saturated electron pressure anisotropy, $\Delta
+p_e/p_{||,e}$, is determined mainly by the (electron-lengthscale) whistler
+marginal stability condition, with a modest factor of $\sim 1.5-2$ decrease due
+to the trapping of electrons by the mirrors. We explicitly calculate the mean
+free path of the electrons and ions along the mean magnetic field and provide a
+simple physical prescription for the mean free path and thermal conductivity in
+low-collisionality $\beta_j \gtrsim 1$ plasmas. Our results imply that
+velocity-space instabilities likely decrease the thermal conductivity of plasma
+in the outer parts of massive, hot, galaxy clusters. We also discuss the
+implications of our results for electron heating and thermal conduction in
+low-collisionality accretion flows onto black holes, including Sgr A* in the
+Galactic Center.",1602.03126v2
+2016-08-10,Non-Maxwellian electron distribution functions due to self-generated turbulence in collisionless guide-field reconnection,"Non-Maxwellian electron velocity space distribution functions (EVDF) are
+useful signatures of plasma conditions and non-local consequences of
+collisionless magnetic reconnection. In the past, EVDFs were obtained mainly
+for antiparallel reconnection and under the influence of weak guide-fields in
+the direction perpendicular to the reconnection plane. EVDFs are, however, not
+well known, yet, for oblique (or component-) reconnection in dependence on
+stronger guide-magnetic fields and for the exhaust (outflow) region of
+reconnection away from the diffusion region. In view of the multi-spacecraft
+Magnetospheric Multiscale Mission (MMS), we derived the non-Maxwellian EVDFs of
+collisionless magnetic reconnection in dependence on the guide-field strength
+$b_g$ from small ($b_g\approx0$) to very strong ($b_g=8$) guide-fields, taking
+into account the feedback of the self-generated turbulence. For this sake, we
+carried out 2.5D fully-kinetic Particle-in-Cell simulations using the ACRONYM
+code. We obtained anisotropic EVDFs and electron beams propagating along the
+separatrices as well as in the exhaust region of reconnection. The beams are
+anisotropic with a higher temperature in the direction perpendicular rather
+than parallel to the local magnetic field. The beams propagate in the direction
+opposite to the background electrons and cause instabilities. We also obtained
+the guide-field dependence of the relative electron-beam drift speed, threshold
+and properties of the resulting streaming instabilities including the strongly
+non-linear saturation of the self-generated plasma turbulence. This turbulence
+and its non-linear feedback cause non-adiabatic parallel electron acceleration
+and EVDFs well beyond the limits of the quasi-linear approximation, producing
+phase space holes and an isotropizing pitch-angle scattering.",1608.03110v2
+2016-12-22,Disruption of sheetlike structures in Alfvénic turbulence by magnetic reconnection,"We propose a mechanism whereby the intense, sheet-like structures naturally
+formed by dynamically aligning Alfv\'enic turbulence are destroyed by magnetic
+reconnection at a scale $\hat{\lambda}_{\rm D}$, larger than the dissipation
+scale predicted by models of intermittent, dynamically aligning turbulence. The
+reconnection process proceeds in several stages: first, a linear tearing mode
+with $N$ magnetic islands grows and saturates, and then the $X$-points between
+these islands collapse into secondary current sheets, which then reconnect
+until the original structure is destroyed. This effectively imposes an upper
+limit on the anisotropy of the structures within the perpendicular plane, which
+means that at scale $\hat{\lambda}_{\rm D}$ the turbulent dynamics change: at
+scales larger than $\hat{\lambda}_{\rm D}$, the turbulence exhibits
+scale-dependent dynamic alignment and a spectral index approximately equal to
+$-3/2$, while at scales smaller than $\hat{\lambda}_{\rm D}$, the turbulent
+structures undergo a succession of disruptions due to reconnection, limiting
+dynamic alignment, steepening the effective spectral index and changing the
+final dissipation scale. The scaling of $\hat{\lambda}_{\rm D}$ with the
+Lundquist (magnetic Reynolds) number $S_{L_\perp}$ depends on the order of the
+statistics being considered, and on the specific model of intermittency; the
+transition between the two regimes in the energy spectrum is predicted at
+approximately $\hat{\lambda}_{\rm D} \sim S_{L_\perp}^{-0.6}$. The spectral
+index below $\hat{\lambda}_{\rm D}$ is bounded between $-5/3$ and $-2.3$. The
+final dissipation scale is at $\hat{\lambda}_{\eta,\infty}\sim
+S_{L_\perp}^{-3/4}$, the same as the Kolmogorov scale arising in theories of
+turbulence that do not involve scale-dependent dynamic alignment.",1612.07604v3
+2017-01-11,Spontaneous flux concentrations from the negative effective magnetic pressure instability beneath a radiative stellar surface,"The formation of sunspots requires the concentration of magnetic flux near
+the surface. The negative magnetic pressure instability (NEMPI) might be a
+possible mechanism for accomplishing this, but it has mainly been studied in
+simple systems using an isothermal equation of state without a natural free
+surface. We study NEMPI in a stratified Cartesian mean-field model where
+turbulence effects are parameterized. We use an ideal equation of state and
+include radiation transport, which establishes selfconsistently a free surface.
+We use a Kramers-type opacity with adjustable exponents chosen such that the
+deeper layers are approximately isentropic. No convection is therefore possible
+in this model, allowing us to study NEMPI with radiation in isolation. We
+restrict ourselves to two-dimensional models. We use artificially enhanced
+mean-field coefficients to allow NEMPI to develop, making it therefore possible
+to study the reason why it is much harder to excite in the presence of
+radiation. NEMPI yields moderately strong magnetic flux concentrations a
+certain distance beneath the surface where optical depth is unity. The
+instability is oscillatory and in the form of upward travelling waves. This
+seems to be a new effect that has not been found in earlier models without
+radiative transport. The horizontal wavelength is about ten times smaller than
+what has been found previously in more idealized isothermal models. In our
+models, NEMPI saturates at field strengths too low to explain sunspots.
+Furthermore, the structures appear too narrow and too far beneath the surface
+to cause significant brightness variations at the radiative surface. We
+speculate that the failure to reproduce effects resembling sunspots may be
+related to the neglect of convection.",1701.03018v2
+2017-02-03,Giant magnetoresistance and structure of electrodeposited Co/Cu multilayers: the influence of layer thicknesses and Cu deposition potential,"The giant magnetoresistance (GMR) and structure was investigated for
+electrodeposited Co/Cu multilayers prepared by a conventional
+galvanostatic/potentiostatic pulse combination from a pure sulfate electrolyte
+with various layer thicknesses, total multilayer thickness and Cu deposition
+potential. X-ray diffraction (XRD) measurements revealed superlattice satellite
+reflections for many of the multilayers having sufficiently large thickness (at
+least 2 nm) of both constituent layers. The bilayer repeats derived from the
+positions of the visible superlattice reflections were typically 10-20% higher
+than the nominal values.The observed GMR was found to be dominated by the
+multilayer-like ferromagnetic (FM) contribution even for multilayers without
+visible superlattice satellites. There was always also a modest
+superparamagnetic (SPM) contribution to the GMR and this term was the largest
+for multilayers with very thin (0.5 nm) magnetic layers containg apparently a
+small amount of magnetically decoupled SPM regions. No oscillatory GMR behavior
+with spacer thickness was observed at any magnetic layer thickness. The
+saturation of the coercivity as measured by the peak position of the MR(H)
+curves indicated a complete decoupling of magnetic layers for large spacer
+thicknesses. The GMR increased with total multilayer thickness which could be
+ascribed to an increasing SPM contribution to the GMR due to an increasing
+surface roughness, also indicated by the increasing coercivity. For multilayers
+with Cu layers deposited at more and more positive potentials, the GMRFM term
+increased and the GMRSPM term decreased. At the same time, a corresponding
+reduction of surface roughness measured with atomic force microscopy indicated
+an improvement of the multilayer structural quality which was, however, not
+accompanied by an increase of the superlattice reflection intensities.",1702.01065v1
+2017-06-27,Solar Cycle Variability Induced by Tilt Angle Scatter in a Babcock--Leighton Solar Dynamo Model,"We present results from a three-dimensional Babcock--Leighton dynamo model
+that is sustained by the explicit emergence and dispersal of bipolar magnetic
+regions (BMRs). On average, each BMR has a systematic tilt given by Joy's law.
+Randomness and nonlinearity in the BMR emergence of our model produce variable
+magnetic cycles. However, when we allow for a random scatter in the tilt angle
+to mimic the observed departures from Joy's law, we find more variability in
+the magnetic cycles. We find that the observed standard deviation in Joy's law
+of $\sigma_\delta = 15^\circ$ produces a variability comparable to observed
+solar cycle variability of $\sim $ 32%, as quantified by the sunspot number
+maxima between 1755--2008. We also find that tilt angle scatter can promote
+grand minima and grand maxima. The time spent in grand minima for
+$\sigma_\delta = 15^\circ$ is somewhat less than that inferred for the Sun from
+cosmogenic isotopes (about 9% compared to 17%). However, when we double the
+tilt scatter to $\sigma_\delta = 30^\circ$, the simulation statistics are
+comparable to the Sun ($\sim $18% of the time in grand minima and $\sim 10$% in
+grand maxima). Though the Babcock--Leighton mechanism is the only source of
+poloidal field, we find that our simulations always maintain magnetic cycles
+even at large fluctuations in the tilt angle. We also demonstrate that tilt
+quenching is a viable and efficient mechanism for dynamo saturation; a
+suppression of the tilt by only 1-2$^\circ$ is sufficient to limit the dynamo
+growth. Thus, any potential observational signatures of tilt quenching in the
+Sun may be subtle.",1706.08933v2
+2017-09-06,Dispersion of the solar magnetic flux in undisturbed photosphere as derived from SDO/HMI data,"To explore the magnetic flux dispersion in the undisturbed solar photosphere,
+magnetograms acquired by Helioseismic and Magnetic Imager (HMI) onboard the
+Solar Dynamic Observatory (SDO) were utilized. Two areas, a coronal hole area
+(CH) and an area of super-granulation pattern, SG, were analyzed. We explored
+the displacement and separation spectra and the behavior of the turbulent
+diffusion coefficient, $K$. The displacement and separation spectra are very
+similar to each other. Small magnetic elements (of size 3-100 squared pixels
+and the detection threshold of 20 Mx sm$^{-2}$) in both CH and SG areas
+disperse in the same way and they are more mobile than the large elements (of
+size 20-400 squared pixels and the detection threshold of 130 Mx sm$^{-2}$).
+The regime of super-diffusivity is found for small elements ($\gamma \approx
+1.3 $ and $K$ growing from $\sim$100 to $\sim$ 300 km$^2$ s$^{-1}$). Large
+elements in the CH area are scanty and show super-diffusion with $\gamma
+\approx 1.2$ and $K$ = (62-96) km$^2$ s$^{-1}$ on rather narrow range of
+500-2200 km. Large elements in the SG area demonstrate two ranges of linearity
+and two diffusivity regimes: sub-diffusivity on scales (900-2500) km with
+$\gamma=0.88$ and $K$ decreasing from $\sim$130 to $\sim$100 km$^2$ s$^{-1}$,
+and super-diffusivity on scales (2500-4800) km with $\gamma \approx 1.3$ and
+$K$ growing from $\sim$140 to $\sim$200 km$^2$ s$^{-1}$. Comparison of our
+results with the previously published shows that there is a tendency of
+saturation of the diffusion coefficient on large scales, i.e., the turbulent
+regime of super-diffusivity is gradually replaced by normal diffusion.",1709.01724v1
+2017-11-21,Thickness-dependence of the Dzyaloshinskii-Moriya interaction in Co2FeAl ultrathin films: effects of the annealing temperature and the heavy metal material,"Interfacial Dzyaloshinskii-Moriya interaction (iDMI) has been investigated in
+Co2FeAl (CFA) ultrathin films of various thicknesses (0.8 nm<tCFA<2 nm) grown
+on Si substrates, using Pt, W, Ir and MgO buffer or/and capping layers.
+Vibrating sample magnetometry revealed that magnetization at saturation (Ms)
+for the Pt and Ir buffered films is higher than the usual Ms of CFA due to the
+proximity induced magnetization (PIM) in Ir and Pt, estimated to be 19% and
+27%, respectively. The presence of PIM in these materials is confirmed using
+x-ray resonant magnetic reflectivity. Moreover, while no PIM is induced in W,
+higher PIM is obtained with Pt when it is used as buffer layer rather than
+capping layer. Brillouin light scattering (BLS) in the Damon-Eshbach geometry
+has been used to investigate iDMI constants and the perpendicular anisotropy
+field versus the annealing temperature. The DMI sign has been found to be
+negative for Pt/CFA and Ir/CFA while it is positive for W/CFA. The thickness
+dependence of the effective iDMI constant for stacks involving Pt and W shows
+the existence of two regimes similarly to that of the perpendicular anisotropy
+constant due to the degradation of the interfaces as the CFA thickness
+approaches the nanometer. The surface iDMI and anisotropy constants of each
+stack have been determined for the thickest samples where a linear thickness
+dependence of the effective iDMI constant and the effective magnetization has
+been observed. The interface anisotropy and iDMI constants, investigated for
+Pt/CFA/MgO system, showed different trends with the annealing temperature. The
+decrease of iDMI constant with increasing annealing temperature is probably due
+to the electronic structure changes at the interfaces, while the increase of
+the interface anisotropy constant is coherent the interface quality and
+disorder enhancement.",1711.07776v1
+2018-05-17,Modification of Spin Ice Physics in Ho$_2$Ti$_2$O$_7$ Thin Films,"We present an extensive study on the effect of substrate orientation, strain,
+stoichiometry and defects on spin ice physics in Ho$_2$Ti$_2$O$_7$ thin films
+grown onto yttria-stabilized-zirconia substrates. We find that growth in
+different orientations produces different strain states in the films. All films
+exhibit similar c-axis lattice parameters for their relaxed portions, which are
+consistently larger than the bulk value of 10.10 \AA. Transmission electron
+microscopy reveals anti-site disorder and growth defects to be present in the
+films, but stuffing is not observed. The amount of disorder depends on the
+growth orientation, with the (110) film showing the least. Magnetization
+measurements at 1.8 K show the expected magnetic anisotropy and saturation
+magnetization values associated with a spin ice for all orientations; shape
+anisotropy is apparent when comparing in and out-of-plane directions.
+Significantly, only the (110) oriented films display the hallmark spin ice
+plateau state in magnetization, albeit less well-defined compared to the
+plateau observed in a single crystal. Neutron scattering maps on the more
+disordered (111) oriented films show the Q=0 phase previously observed in bulk
+materials, but the Q=X phase giving the plateau state remains elusive. We
+conclude that the spin ice physics in thin films is modified by defects and
+strain, leading to a reduction in the temperature at which correlations drive
+the system into the spin ice state.",1805.06565v2
+2018-07-31,High Resolution Imaging of the Magnetic Field in the central parsec of the Galaxy,"We discuss a high resolution (FWHM~ 0.45 arcsec) image of the emissive
+polarization from warm dust in the minispiral in the Galactic Centre and
+discuss the implications for the magnetic field in the dusty filaments. The
+image was obtained at a wavelength of 12.5 microns with the CanariCam multimode
+mid-infrared imager on the Gran Telescopio Canarias. It confirms the results
+obtained from previous observations but also reveals new details of the
+polarization structures. In particular, we identify regions of coherent
+magnetic field emission at position angles of ~45 deg to the predominantly
+north--south run of field lines in the Northern Arm which may be related to
+orbital motions inclined to the general flow of the Northern Arm. The luminous
+stars that have been identified as bow-shock sources in the Northern Arm do not
+disrupt or dilute the field but are linked by a coherent field structure,
+implying that the winds from these objects may push and compress the field but
+do not overwhelm it. The magnetic field in the the low surface brightness
+regions in the East-West Bar to the south of SgrA* lies along the Bar, but the
+brighter regions generally have different polarization position angles,
+suggesting that they are distinct structures. In the region of the Northern Arm
+sampled here, there is only a weak correlation between the intensity of the
+emission and the degree of polarization. This is consistent with saturated
+grain alignment where the degree of polarization depends on geometric effects,
+including the angle of inclination of the field to the line of sight and
+superposition of filaments with different field directions, rather than the
+alignment efficiency.",1807.11744v1
+2018-09-10,Magnetic properties and field-driven dynamics of chiral domain walls in epitaxial Pt/Co/Au$_x$Pt$_{1-x}$ trilayers,"Chiral domain walls in ultrathin perpendicularly magnetised layers have a
+N\'{e}el structure stabilised by a Dzyaloshinskii-Moriya interaction (DMI) that
+is generated at the interface between the ferromagnet and a heavy metal.
+Different heavy metals are required above and below a ferromagnetic film in
+order to generate the structural inversion asymmetry needed to ensure that the
+DMI arising at the two interfaces does not cancel. Here we report on the
+magnetic properties of epitaxial Pt/Co/Au$_x$Pt$_{1-x}$ trilayers grown by
+sputtering onto sapphire substrates with 0.6 nm thick Co. As $x$ rises from 0
+to 1 a structural inversion asymmetry is generated. We characterise the
+epilayer structure with x-ray diffraction and cross-sectional transmission
+electron microscopy, revealing (111) stacking. The saturation magnetization
+falls as the proximity magnetisation in Pt is reduced, whilst the perpendicular
+magnetic anisotropy $K_\mathrm{u}$ rises. The micromagnetic DMI strength $D$
+was determined using the bubble expansion technique and also rises from a
+negligible value when $x=0$ to $\sim 1$ mJ/m$^2$ for $x = 1$. The depinning
+field at which field-driven domain wall motion crosses from the creep to the
+depinning regime rises from $\sim 40$ to $\sim 70$ mT, attributed to greater
+spatial fluctuations of the domain wall energy with increasing Au
+concentration. Meanwhile, the increase in DMI causes the Walker field to rise
+from $\sim 10$ to $\sim 280$ mT, meaning that only in the $x = 1$ sample is the
+steady flow regime accessible. The full dependence of domain wall velocity on
+driving field bears little resemblance to the prediction of a simple
+one-dimensional model, but can be described very well using micromagnetic
+simulations with a realistic model of disorder. These reveal a rise in Gilbert
+damping as $x$ increases.",1809.03217v2
+2019-01-14,Finding pathways for stoichiometric Co4N thin films,"In this work, we studied the pathways for formation of stoichiometric
+\tcn~thin films. Polycrystalline and epitaxial \tcn~films were prepared using
+reactive direct current magnetron (dcMS) sputtering technique. A systematic
+variation in the substrate temperature (\Ts) during the dcMS process reveals
+that the lattice parameter (LP) decreases as \Ts~increases. We found that
+nearly stoichiometric \tcn~films can be obtained when \Ts~= 300\,K. However,
+they emerge from the transient state of Co target ($\phi$3\,inch). By reducing
+the target size to $\phi$1\,inch, now the \tcn~phase formation takes place from
+the metallic state of Co target. In this case, LP of \tcn~film comes out to be
+$\sim$99\p~of the value expected for \tcn. This is the largest value of LP
+found so far for \tcn. The pathways achieved for formation of polycrystalline
+\tcn~were adopted to grow an epitaxial \tcn~film, which shows four fold
+magnetic anisotropy in magneto-optic Kerr effect measurements. Detailed
+characterization using secondary ion mass spectroscopy indicates that N
+diffuses out when \Ts~is raised even to 400\,K. Measurement of electronic
+structure using x-ray photoelectron spectroscopy and x-ray absorption
+spectroscopy further confirms it. Magnetization measurements using bulk
+magnetization and polarized neutron reflectivity show that the saturation
+magnetization of stoichiometric \tcn~film is even larger than pure Co. Since
+all our measurements indicated that N could be diffusing out, when \tcn~films
+are grown at high \Ts, we did actual N self-diffusion measurements in a CoN
+sample and found that N self-diffusion was indeed substantially higher. The
+outcome of this work clearly shows that the \tcn~films grown prior to this work
+were always N deficient and the pathways for formation of a stoichiometric
+\tcn~have been achieved.",1901.04139v1
+2019-04-16,Numerical study of tearing mode seeding in tokamak X-point plasma,"A detailed understanding of island seeding is crucial to avoid (N)TMs and
+their negative consequences like confinement degradation and disruptions. In
+the present work, we investigate the growth of 2/1 islands in response to
+magnetic perturbations. Although we use externally applied perturbations
+produced by resonant magnetic perturbation (RMP) coils for this study, results
+are directly transferable to island seeding by other MHD instabilities creating
+a resonant magnetic field component at the rational surface. Experimental
+results for 2/1 island penetration from ASDEX Upgrade are presented extending
+previous studies. Simulations are based on an ASDEX Upgrade L-mode discharge
+with low collisionality and active RMP coils. Our numerical studies are
+performed with the 3D, two fluid, non-linear MHD code JOREK. All three phases
+of mode seeding observed in the experiment are also seen in the simulations:
+first a weak response phase characterized by large perpendicular electron flow
+velocities followed by a fast growth of the magnetic island size accompanied by
+a reduction of the perpendicular electron velocity, and finally the saturation
+to a fully formed island state with perpendicular electron velocity close to
+zero. Thresholds for mode penetration are observed in the plasma rotation as
+well as in the RMP coil current. A hysteresis of the island size and electron
+perpendicular velocity is observed between the ramping up and down of the RMP
+amplitude consistent with an analytically predicted bifurcation. The transition
+from dominant kink/bending to tearing parity during the penetration is
+investigated.",1904.07542v1
+2019-09-10,Contributions of magnetic structure and nitrogen to perpendicular magnetocrystalline anisotropy in antiperovskite $ε$-Mn$_4$N,"To study how nitrogen contributes to perpendicular magnetocrystalline
+anisotropy (PMA) in the ferrimagnetic antiperovskite Mn$_4$N, we examined both
+the fabrication of epitaxial Mn$_4$N films with various nitrogen contents and
+first-principles density-functional calculations. Saturation magnetization
+($M_{\rm s}$) peaks of 110 mT and uniaxial PMA energy densities ($K_{\rm u}$)
+of 0.1 MJ/m$^3$ were obtained for a N$_2$ gas flow ratio ($Q$) of $\sim 10 \%$
+during sputtering deposition, suggesting nearly single-phase crystalline
+$\epsilon$-Mn$_4$N. Segregation of $\alpha$-Mn and nitrogen-deficient Mn$_4$N
+grains was observed for $Q \approx 6\%$, which was responsible for a decrease
+in the $M_{\rm s}$ and $K_{\rm u}$. The first-principles calculations revealed
+that the magnetic structure of Mn$_4$N showing PMA was ""type-B"" having a
+collinear structure, whose magnetic moments couple parallel within the c-plane
+and alternating along the c-direction. In addition, the $K_{\rm u}$ calculated
+using Mn$_{32}$N$_x$ supercells showed a strong dependence on nitrogen
+deficiency, in qualitative agreement with the experimental results. The
+second-order perturbation analysis of $K_{\rm u}$ with respect to the
+spin-orbit interaction revealed that not only spin-conserving but also
+spin-flip processes contribute significantly to the PMA in Mn$_4$N. We also
+found that both contributions decreased with increasing nitrogen deficiency,
+resulting in the reduction of $K_{\rm u}$. It was noted that the decrease in
+the spin-flip contribution occurred at the Mn atoms in face-centered sites.
+This is one of the specific PMA characteristics we found for
+antiperovskite-type Mn$_4$N.",1909.04308v3
+2020-04-27,"Hadamard magnetization transfers achieve dramatic sensitivity enhancements in homonuclear multidimensional NMR correlations of labile sites in proteins, polysaccharides and nucleic acids","EXSY, TOCSY and NOESY lie at the foundation of homonuclear NMR experiments in
+organic and pharmaceutical chemistry, as well as in structural biology. Limited
+magnetization transfer efficiency is an intrinsic downside of these methods,
+particularly when targeting rapidly exchanging species such as labile protons
+ubiquitous in polysaccharides, sidechains and backbones of proteins, and in
+bases and sugars of nucleic acids: the fast decoherence imparted on these
+protons through solvent exchanges, greatly reduces their involvement in
+homonuclear correlation experiments. We have recently discussed how these
+decoherences can be visualized as an Anti-Zeno Effect, that can be harnessed to
+enhance the efficiency of homonuclear transfers within Looped PROjected
+SpectroscopY (L-PROSY) leading to 200-300% enhancements in NOESY and TOCSY
+cross-peaks for amide groups in biomolecules. This study demonstrates that even
+larger sensitivity gains per unit time, equivalent to reductions by several
+hundred-folds in the duration of experiments, can be achieved by looping
+inversion or using saturation procedures. In the ensuing experiments a priori
+selected frequencies are encoded according to Hadamard recipes, and
+subsequently resolved along the indirect dimension via linear combinations.
+Magnetization-transfer (MT) processes reminiscent of those occurring in CEST
+provide significant enhancements in the resulting cross-peaks, in only a
+fraction of acquisition time of a normal 2D experiment. The effectiveness of
+the ensuing three-way polarization transfer interplay between water, labile and
+non-labile protons was corroborated experimentally for proteins,
+homo-oligosaccharides and nucleic acids. In all cases, cross-peaks barely
+detectable in conventional 2D NMR counterparts, were measured ca. 10-fold
+faster and with 200-600% signal enhancements by the Hadamard MT counterparts.",2004.13063v1
+2020-05-20,Alfvén-wave driven magnetic rotator winds from low-mass stars I: rotation dependences of magnetic braking and mass-loss rate,"Observations of stellar rotation show that low-mass stars lose angular
+momentum during the main sequence. We simulate the winds of Sun-like stars with
+a range of rotation rates, covering the fast and slow magneto-rotator regimes,
+including the transition between the two. We generalize an Alfv\'en-wave driven
+solar wind model that builds on previous works by including the
+magneto-centrifugal force explicitly. In this model, the surface-averaged open
+magnetic flux is assumed to scale as $B_\ast f^{\rm open}_\ast \propto {\rm
+Ro}^{-1.2}$, where $f^{\rm open}_\ast$ and ${\rm Ro}$ are the surface open-flux
+filling factor and Rossby number, respectively. We find that, 1. the angular
+momentum loss rate (torque) of the wind is described as $\tau_w \approx 2.59
+\times 10^{30} {\rm \ erg} \ \left( \Omega_\ast / \Omega_\odot \right)^{2.82}$,
+yielding a spin-down law $\Omega_\ast \propto t^{-0.55}$. 2. the mass-loss rate
+saturates at $\dot{M}_w \sim 3.4 \times 10^{-14} M_\odot {\rm \ yr^{-1}}$, due
+to the strong reflection and dissipation of Alfv\'en waves in the chromosphere.
+This indicates that the chromosphere has a strong impact in connecting the
+stellar surface and stellar wind. Meanwhile, the wind ram pressure scales as
+$P_w \propto \Omega_\ast^{0.57}$, which is able to explain the lower-envelope
+of the observed stellar winds by Wood et al. 3. the location of the Alfv\'en
+radius is shown to scale in a way that is consistent with 1D analytic theory.
+Additionally, the precise scaling of the Alfv\'en radius matches previous works
+which used thermally-driven winds. Our results suggest that the Alfv\'en-wave
+driven magnetic rotator wind plays a dominant role in the stellar spin-down
+during the main-sequence.",2005.09817v2
+2020-08-13,On the detection of surface spin freezing in iron oxide nanoparticles and its long-term evolution under ambient oxidation,"Exchange bias effects linked to surface spin freezing (SSF) are commonly
+found in iron oxide nanoparticles, while signatures of SSF in low-field
+temperature-dependent magnetization curves have been much less frequently
+reported. Here, we present magnetic properties of dense assemblies of
+similar-sized (~ 8 nm diameter) particles synthesized by a magnetite (sample
+S1) and a maghemite (sample S2) method, and the influence of long-term (4-year)
+sample aging under ambient conditions on these properties. The size of the
+exchange bias field of the different sample (fresh or aged) states is found to
+correlate with (a) whether a low-temperature hump feature signaling the SSF
+transition is detected in out-of-phase ac susceptibility or zero-field-cooled
+(ZFC) dc magnetization recorded at low field and with (b) the prominence of
+irreversibility between FC and ZFC curves recorded at high field. Sample S1
+displays a lower magnetization than S2, and it is in S1 where the largest SSF
+effects are found. These effects are significantly weakened by aging but remain
+larger than the SSF effects in S2, where the influence of aging is considerably
+smaller. A non-saturating component due to spin disorder in S1 also weakens
+with aging, accompanied by, we infer, an increase in the superspin and the
+radius of the ordered nanoparticle cores. X-ray diffraction and M\""ossbauer
+spectroscopy provide indication of maghemite-like stoichiometry in both aged
+samples as well as thicker disordered particle shells in aged-S1 relative to
+aged-S2 (crystallographically-disordered and spin-disordered according to
+diffraction and M\""ossbauer, respectively). The pronounced diminution in SSF
+effects with aging in S1 is attributed to a (long-term) transition, caused by
+ambient oxidation, from magnetite-like to maghemite-like stoichiometry, and a
+concomitant softening of the spin-disordered shell anisotropy...",2008.05874v1
+2020-09-14,Shear-Driven Transition to Isotropically Turbulent Solar Wind Outside the Alfven Critical Zone,"Motivated by prior remote observations of a transition from striated solar
+coronal structures to more isotropic ``flocculated'' fluctuations, we propose
+that the dynamics of the inner solar wind just outside the Alfv\'en critical
+zone, and in the vicinity of the first $\beta=1$ surface, is powered by the
+relative velocities of adjacent coronal magnetic flux tubes. We suggest that
+large amplitude flow contrasts are magnetically constrained at lower altitude
+but shear-driven dynamics are triggered as such constraints are released above
+the Alfv\'en critical zone, as suggested by global magnetohydrodynamic (MHD)
+simulations that include self-consistent turbulence transport. We argue that
+this dynamical evolution accounts for features observed by {\it Parker Solar
+Probe} ({\it PSP}) near initial perihelia, including magnetic ``switchbacks'',
+and large transverse velocities that are partially corotational and saturate
+near the local Alfv\'en speed. Large-scale magnetic increments are more
+longitudinal than latitudinal, a state unlikely to originate in or below the
+lower corona. We attribute this to preferentially longitudinal velocity shear
+from varying degrees of corotation. Supporting evidence includes comparison
+with a high Mach number three-dimensional compressible MHD simulation of
+nonlinear shear-driven turbulence, reproducing several observed diagnostics,
+including characteristic distributions of fluctuations that are qualitatively
+similar to {\it PSP} observations near the first perihelion. The concurrence of
+evidence from remote sensing observations, {\it in situ} measurements, and both
+global and local simulations supports the idea that the dynamics just above the
+Alfv\'en critical zone boost low-frequency plasma turbulence to the level
+routinely observed throughout the explored solar system.",2009.06537v1
+2020-11-05,Polarized emission of CdSe nanocrystals in magnetic field: the role of phonon-assisted recombination of the dark exciton,"The recombination dynamics and spin polarization of excitons in CdSe
+nanocrystals synthesized in a glass matrix are investigated using polarized
+photoluminescence in high magnetic fields up to 30 Tesla. The dynamics are
+accelerated by increasing temperature and magnetic field, confirming the dark
+exciton nature of the low-temperature photoluminescence (PL). The circularly
+polarized PL in magnetic fields reveals several unusual appearances: (i) a
+spectral dependence of the polarization degree, (ii) its low saturation value,
+and (iii) a stronger intensity of the Zeeman component which is higher in
+energy. The latter feature is the most surprising being in contradiction with
+the thermal population of the exciton spin sublevels. The same contradiction
+was previously observed in the ensemble of wet-chemically synthesized CdSe
+nanocrystals, but was not understood. We present a theory which explains all
+the observed features and shows that the inverted ordering of the circular
+polarized PL maxima from the ensemble of nanocrystals is a result of
+competition between the zero phonon (ZPL) and one optical phonon (1PL) assisted
+emission of the dark excitons. The essential aspects of the theoretical model
+are different polarization properties of the dark exciton emission via ZPL and
+1PL recombination channels and the inhomogeneous broadening of the PL spectrum
+from the ensemble of nanocrystals exceeding the optical phonon energy.",2011.02786v1
+2021-11-14,"Structure, optical and magnetic properties of Fe doped, Fe+Cr co-doped ZnO nanoparticles","The study particularly focuses on the effect of the Cr co-doping on the
+structural, optical and magnetic properties of Zn0.99Fe0.01O.
+Zn0.99-xFe0.01CrxO (x =0, 0.01, 0.03 and 0.05) nanoparticles. Powder x-ray
+diffraction (XRD) analysis confirms all the samples have hexagonal wurtzite
+structures. The average crystallite size (D) and microstrain of the samples
+were calculated using the Williamson-Hall relation and D was found to be 13 +-
+1 nm for Zn0.99Fe0.01O. In Cr co-doped samples, D increase slightly with Cr
+content and are given by 9 +- 1, 10 +- 1, and 11 +- 1 nm for the samples with x
+= 0.01, 0.03 and 0.05, respectively; while the strain decreased with increase
+in Cr co-doping. Transmission electron microscopy (TEM) images of the samples
+indicate that particles are in the nano-regime and agglomerated. Particle sizes
+are found to be 14 +- 1, 11 +- 1 and 12 +- 1 nm for Zn0.99-xFe0.01CrxO with x =
+0, 0.03 and 0.05, respectively. The substitution of Fe3+ and Cr3+ at Zn2+ sites
+has an impact on the optical properties. The band-gap decreases from 3.296 +-
+0.002 eV to 3.258 +- 0.002 eV with increase of Cr concentration.
+Photoluminescence (PL) of Zn0.96Fe0.01Cr0.03O revealed the presence of defects,
+the emission peaks at 410 nm and 513 nm are attributed to Zn vacancies (VZn)
+and singly ionized oxygen vacancies, respectively. The M(-H) curves of
+Zn0.99-xFe0.01CrxO (x = 0.03 and 0.05) measured at room temperature using a
+vibrating sample magnetometer (VSM) are found to be hysteretic, signifying room
+temperature ferromagnetism (RTFM). Maximum saturation magnetization, 0.67 +-
+0.01 emu.g-1, is observed in Zn0.94Fe0.01Cr0.05O. The observed RTFM in Fe+Cr
+co-doped ZnO is explained by of bound magnetic polaron (BMP) mechanism, the
+BMPs are formed by VZn and Vo^+ defects. This paper enhances the understanding
+of the origin of RTFM in Fe+Cr co-doped ZnO nanoparticles.",2111.07266v1
+2022-04-23,3D Simulations of Strongly Magnetised Non-Rotating Supernovae: Explosion Dynamics and Remnant Properties,"We investigate the impact of strong initial magnetic fields in core-collapse
+supernovae of non-rotating progenitors by simulating the collapse and explosion
+of a 16.9 Msun star for a strong- and weak-field case assuming a twisted-torus
+field with initial central field strengths of ~1012 G and ~106 G. The
+strong-field model has been set up with a view to the fossil-field scenario for
+magnetar formation and emulates a pre-collapse field configuration that may
+occur in massive stars formed by a merger. This model undergoes shock revival
+already 100 s after bounce and reaches an explosion energy of 9.3 x 10^50 erg
+at 310 ms, in contrast to a more delayed and less energetic explosion in the
+weak-field model. The strong magnetic fields help trigger a neutrino-driven
+explosion early on, which results in a rapid rise and saturation of the
+explosion energy. Dynamically, the strong initial field leads to a fast
+build-up of magnetic fields in the gain region to 40% of kinetic equipartition
+and also creates sizable pre-shock ram pressure perturbations that are known to
+be conducive to asymmetric shock expansion. For the strong-field model, we find
+an extrapolated neutron star kick of ~350 km/s, a spin period of ~70 ms, and no
+spin-kick alignment. The dipole field strength of the proto-neutron star is 2 x
+10^14 G by the end of the simulation with a declining trend. Surprisingly, the
+surface dipole field in the weak-field model is stronger, which argues against
+a straightforward connection between pre-collapse fields and the birth magnetic
+fields of neutron stars.",2204.11009v3
+2022-05-11,Effect of magnetic phase coexistence on spin-phonon coupling and magnetoelectric effect in polycrystalline Sm0.5Y0.5Fe0.58Mn0.42O3,"The polycrystalline co-doped samples of Sm0.5Y0.5Fe0.58Mn0.42O3 were prepared
+by solid-state reaction route and its various physical properties with their
+correlations have been investigated. The dc magnetization measurements on the
+sample revealed a weak ferromagnetic (WFM) transition at TN=361 K that is
+followed by an incomplete spin reorientation (SR) transition at TSR1= 348 K. A
+first order magnetic transition (FOMT) around 292 K completes the spin
+reorientation transition and the material enters into a nearly collinear
+antiferromagnetic (AFM) state for T < 260 K. The compound exhibited
+magnetization reversal below the compensation temperature (Tcomp) = 92 K at low
+measured field of 100 Oe. At further low temperature below 71 K, the compound
+also exhibited Zero-field cooled memory effects confirming a reentrant
+spinglass state formation. Robust magnetodielectric (MD) magnetoelectric
+coupling has been established in the present material through field dependent
+dielectric and resistivity measurements. True ferroelectric transition with a
+considerable value of saturation polarization (= 0.06 micro C/cm2 at 15 K) have
+been found in the specimen below TFE= 108 K. We observed an intense spin-phonon
+coupling (SPC) across TSR and TN from the temperature dependent Raman
+spectroscopy and is responsible for the intrinsic magnetoelectric effect. This
+SPC also stabilizes the ferroelectric state below TFE in the material. The
+delicate interplay of the lattice (Phonons), charge and spins governs the
+observed features in the investigated physical properties of the material that
+makes the specimen a promising multifunctional material.",2205.05291v2
+2022-07-19,"Batchelor, Saffman, and Kazantsev spectra in galactic small-scale dynamos","The magnetic fields in galaxy clusters and probably also in the interstellar
+medium are believed to be generated by a small-scale dynamo. Theoretically,
+during its kinematic stage, it is characterized by a Kazantsev spectrum, which
+peaks at the resistive scale. It is only slightly shallower than the Saffman
+spectrum that is expected for random and causally connected magnetic fields.
+Causally disconnected fields have the even steeper Batchelor spectrum. Here we
+show that all three spectra are present in the small-scale dynamo. During the
+kinematic stage, the Batchelor spectrum occurs on scales larger than the
+energy-carrying scale of the turbulence, and the Kazantsev spectrum on smaller
+scales within the inertial range of the turbulence -- even for a magnetic
+Prandtl number of unity. In the saturated state, the dynamo develops a Saffman
+spectrum on large scales, suggestive of the build-up of long-range
+correlations. At large magnetic Prandtl numbers, elongated structures are seen
+in synthetic synchrotron emission maps showing the parity-even E polarization.
+We also observe a significant excess in the E polarization over the parity-odd
+B polarization at subresistive scales, and a deficiency at larger scales. This
+finding is at odds with the observed excess in the Galactic microwave
+foreground emission, which is believed to be associated with larger scales. The
+E and B polarizations may be highly non-Gaussian and skewed in the kinematic
+regime of the dynamo. For dust emission, however, the polarized emission is
+always nearly Gaussian, and the excess in the E polarization is much weaker.",2207.09414v2
+2023-03-03,Comparative study of magnetocaloric properties for Gd$^{3+}$ compounds with different frustrated lattice geometries,"As materials with suppressed ordering temperatures and enhanced ground state
+entropies, frustrated magnetic oxides are ideal candidates for cryogenic
+magnetocaloric refrigeration. While previous materials design has focused on
+tuning the magnetic moments, their interactions, and density of moments on the
+lattice, there has been relatively little attention to frustrated lattices.
+Prior theoretical work has shown that the magnetocaloric cooling rate at the
+saturation field is proportional to a macroscopic number of soft mode
+excitations that arise due to the classical ground state degeneracy. The number
+of these modes is directly determined by the geometry of the frustrating
+lattice. For corner-sharing geometries, the pyrochlore has 50\% more modes than
+the garnet and kagome lattices, whereas the edge-sharing \emph{fcc} has only a
+subextensive number of soft modes. Here, we study the role of soft modes in the
+magnetocaloric effect of four large-spin Gd$^{3+}$ ($L=0$, $J=S=7/2$)
+Heisenberg antiferromagnets on a kagome, garnet, pyrochlore, and \emph{fcc}
+lattice. By comparing measurements of the magnetic entropy change $\Delta S_m$
+of these materials at fields up to $9$~T with predictions using mean-field
+theory and Monte Carlo simulations, we are able to understand the relative
+importance of spin correlations and quantization effects. We observe that
+tuning the value of the nearest neighbor coupling has a more dominant
+contribution to the magnetocaloric entropy change in the liquid-He cooling
+regime ($2$-$20$~K), rather than tuning the number of soft mode excitations.
+Our results inform future materials design in terms of dimensionality, degree
+of magnetic frustration, and lattice geometry.",2303.01773v1
+2023-08-22,"Structural, morphological, and magnetic characterizations of (Fe0.25Mn0.75)2O3 nanocrystals: a comprehensive stoichiometric determination","Iron manganese trioxide (Fe0.25Mn0.75)2O3 nanocrystals were synthesized by
+the sol-gel method. The 80 K Mossbauer spectrum was well-fitted using two
+doublets representing the 8b and 24d crystallographic sites of the
+(FexMn1-x)2O3 phase and two weak extra sextets which were attributed to
+crystalline and amorphous hematite. Our findings showed formation of a bixbyite
+primary phase. The Raman spectrum exhibits six Raman active modes, typical of
+(Fe,Mn)2O3, and two extra Raman modes associated with the secondary hematite
+phase. X-ray photoelectron spectroscopy analysis confirmed the presence of
+oxygen vacancy onto the (FexMn1-x)2O3 particle surface, with varying oxidation
+states. X-band magnetic resonance data revealed a single broad resonance line
+in the whole temperature range (3.8 K - 300 K). The temperature dependence of
+both resonance field and resonance linewidth shows a remarkable change in the
+range of 40 - 50 K, herein credited to surface spin glass behavior. The model
+picture used assumes (FexMn1-x)2O3 nanoparticles with a core-shell structure.
+Results indicate that below about 50 K the spin system of shell reveals a
+paramagnetic to spin glass-like transition upon cooling, with a critical
+temperature estimated at 43 K. In the higher temperature range, the
+superparamagnetic hematite (secondary) phase contributes remarkably to the
+temperature dependence of the resonance linewidth. Zero-field-cooled (ZFC) and
+fieldcooled (FC) data show strong irreversibility and a peak in the ZFC curve
+at 33 K, attributed to a paramagnetic-ferrimagnetic transition of the main
+phase. Hysteresis curve at 5 K shows a low coercive field of 4 kOe, with the
+magnetization not reaching saturation at 70 kOe, suggesting the occurrence of a
+ferrimagnetic core with a magnetic disorder at surface, characteristic of
+core-shell spin-glass-like behavior.",2308.11128v2
+2023-09-30,MRI turbulence in vertically stratified accretion discs at large magnetic Prandtl numbers,"The discovery of the first binary neutron star merger, GW170817, has spawned
+a plethora of global numerical relativity simulations. These simulations are
+often ideal (with dissipation determined by the grid) and/or axisymmetric
+(invoking ad hoc mean-field dynamos). However, binary neutron star mergers
+(similar to X-ray binaries and active galactic nuclei inner discs) are
+characterised by large magnetic Prandtl numbers, $\rm Pm$, (the ratio of
+viscosity to resistivity). $\rm Pm$ is a key parameter determining dynamo
+action and dissipation but it is ill-defined (and likely of order unity) in
+ideal simulations. To bridge this gap, we investigate the magnetorotational
+instability (MRI) and associated dynamo at large magnetic Prandtl numbers using
+fully compressible, three-dimensional, vertically stratified, isothermal
+simulations of a local patch of a disc. We find that, within the bulk of the
+disc ($z\lesssim2H$, where $H$ is the scale-height), the turbulent intensity
+(parameterized by the stress-to-thermal-pressure ratio $\alpha$), and the
+saturated magnetic field energy density, $E_\text{mag}$, produced by the MRI
+dynamo, both scale as a power with Pm at moderate Pm ($4\lesssim \text{Pm}
+\lesssim 32$): $E_\text{mag} \sim \text{Pm}^{0.74}$ and $\alpha \sim
+\text{Pm}^{0.71}$, respectively. At larger Pm ($\gtrsim 32$) we find deviations
+from power-law scaling and the onset of a plateau. Compared to our recent
+unstratified study, this scaling with Pm becomes weaker further away from the
+disc mid-plane, where the Parker instability dominates. We perform a thorough
+spectral analysis to understand the underlying dynamics of small-scale
+MRI-driven turbulence in the mid-plane and of large-scale Parker-unstable
+structures in the atmosphere.",2310.00453v1
+2022-01-11,"Single-crystal epitaxial europium iron garnet films with strain-induced perpendicular magnetic anisotropy: structural, strain, magnetic, and spin transport properties","Single-crystal europium iron garnet (EuIG) thin films epitaxially
+strain-grown on gadolinium gallium garnet (GGG)(100) substrates using off-axis
+sputtering have strain-induced perpendicular magnetic anisotropy (PMA). By
+varying the sputtering conditions, we have tuned the europium/iron (Eu/Fe)
+composition ratios in the films to tailor the film strains. The films exhibited
+an extremely smooth, particle-free surface with roughness as low as 0.1 nm as
+observed using atomic force microscopy. High-resolution x-ray diffraction
+analysis and reciprocal space maps showed in-plane epitaxial film growth, very
+smooth film/substrate interface, excellent film crystallinity with a small full
+width at half maximum of 0.012$^{\circ}$ in the rocking curve scans, and an
+in-plane compressive strain without relaxation. In addition, spherical
+aberration-corrected scanning transmission electron microscopy showed an
+atomically abrupt interface between the EuIG film and GGG. The measured
+squarish out-of-plane magnetization-field hysteresis loops by vibrating sample
+magnetometry in conjunction with the measurements from angle-dependent x-ray
+magnetic dichroism demonstrated the PMA in the films. We have tailored the
+magnetic properties of the EuIG thin films, including saturation magnetization
+ranging from 71.91 to 124.51 emu/c.c. (increase with the (Eu/Fe) ratios),
+coercive field from 27 to 157.64 Oe, and the strength of PMA field ($H_\bot$)
+increasing from 4.21 to 18.87 kOe with the in-plane compressive strain from
+-0.774 to -1.044%. We have also investigated spin transport in Pt/EuIG bi-layer
+structure and evaluated the real part of spin mixing conductance to be
+$3.48\times10^{14} {\Omega}^{-1}m^{-2}$. We demonstrated the current-induced
+magnetization switching with a low critical switching current density of
+$3.5\times10^6 A/cm^2$, showing excellent potential for low-dissipation
+spintronic devices.",2201.03843v1
+2021-07-10,An End-to-End AI-Based Framework for Automated Discovery of CEST/MT MR Fingerprinting Acquisition Protocols and Quantitative Deep Reconstruction (AutoCEST),"Purpose: To develop an automated machine-learning-based method for the
+discovery of rapid and quantitative chemical exchange saturation transfer
+(CEST) MR fingerprinting acquisition and reconstruction protocols.
+  Methods: An MR physics governed AI system was trained to generate optimized
+acquisition schedules and the corresponding quantitative reconstruction
+neural-network. The system (termed AutoCEST) is composed of a CEST saturation
+block, a spin dynamics module, and a deep reconstruction network, all
+differentiable and jointly connected. The method was validated using a variety
+of chemical exchange phantoms and an in-vivo mouse brain at 9.4T.
+  Results: The acquisition times for AutoCEST optimized schedules ranged from
+35-71s, with a quantitative image reconstruction time of only 29 ms. The
+resulting exchangeable proton concentration maps for the phantoms were in good
+agreement with the known solute concentrations for AutoCEST sequences (mean
+absolute error = 2.42 mM; Pearson's r=0.992 , p$<$0.0001), but not for an
+unoptimized sequence (mean absolute error = 65.19 mM; Pearson's r=-0.161,
+p=0.522). Similarly, improved exchange rate agreement was observed between
+AutoCEST and quantification of exchange using saturation power (QUESP) methods
+(mean absolute error: 35.8 Hz, Pearson's r=0.971, p$<$0.0001) compared to an
+unoptimized schedule and QUESP (mean absolute error = 58.2 Hz; Pearson's
+r=0.959, p$<$0.0001). The AutoCEST in-vivo mouse brain semi-solid proton
+volume-fractions were lower in the cortex (12.21$\pm$1.37%) compared to the
+white-matter (19.73 $\pm$ 3.30%), as expected, and the amide proton
+volume-fraction and exchange rates agreed with previous reports.
+  Conclusion: AutoCEST can automatically generate optimized CEST/MT acquisition
+protocols that can be rapidly reconstructed into quantitative exchange
+parameter maps.",2107.04737v1
+2006-04-28,Observation of Saturable and Reverse Saturable Absorption at Longitudinal Surface Plasmon Resonance in Gold Nanorods,"Saturable and reverse saturable absorption at longitudinal surface plasmon
+resonance (SPR) in gold nanorods (Au NRs) have been observed using Z-scan and
+transient absorption techniques with femtosecond laser pulses. At lower
+excitation irradiances, the wavelength dispersion of saturable absorption has
+been determined near the longitudinal mode of SPR with a recovery time
+determined to be a few ten picoseconds on the SPR resonance. With higher
+excitation irradiances, reverse saturable absorption occurs and becomes
+dominant. The underlying mechanisms are discussed. Such reversible saturable
+absorption makes Au NRs an ideal candidate for optical limiting applications.",0604651v1
+2008-06-04,Phenomenological Model and Phase Behavior of Saturated and Unsaturated Lipids and Cholesterol,"We present a phenomenological theory for the phase behavior of ternary
+mixtures of cholesterol and saturated and unsaturated lipids, one which
+describes both liquid and gel phases, and illuminates the mechanism of the
+behavior. In a binary system of the lipids, the two phase separate when the
+saturated chains are well ordered, as in the gel phase, simply due to packing
+effects. In the liquid phase the saturated ones are not sufficiently well
+ordered for separation to occur. The addition of cholesterol, however,
+increases the saturated lipid order to the point that phase separation is once
+again favorable. For the system above the main chain transition of the
+saturated lipid, we can obtain phase diagrams in which there is liquid-liquid
+phase separation in the ternary system but not in any of the binary ones, while
+below that temperature we obtain the more common phase diagram in which a gel
+phase, rich in saturated lipid, appears in addition to the two liquid phases.",0806.0675v1
+2008-06-24,Measurements of the aeolian sand transport saturation length,"The wavelength at which a dune pattern emerges from a flat sand bed is
+controlled by the sediment transport saturation length, which is the length
+needed for the sand flux to adapt to a change of wind strength. The influence
+of the wind shear velocity on this saturation length and on the subsequent dune
+initial wavelength has remained controversial. In this letter, we present
+direct measurements of the saturation length performed in a wind tunnel
+experiment. In complement, initial dune wavelengths are measured under
+different wind conditions -- in particular after storms. Using the linear
+stability analysis of dune formation, it is then possible to deduce the
+saturation length from field data. Both direct and indirect measurements agree
+that the saturation length is almost independent of the wind strength. This
+demonstrates that, in contrast with erosion, grain inertia is the dominant
+dynamical mechanism limiting sediment transport saturation.",0806.3931v1
+2008-12-16,Saturable absorption or slow light?,"Quantitative analysis of slow light experiments utilising coherent population
+oscillation (CPO) in a range of saturably absorbing media, including ruby and
+alexandrite, Er3+:Y2SiO5, bacteriorhodopsin, semi-conductor quantum devices and
+erbium doped optical fibres, shows that the observations may be more simply
+interpreted as saturable absorption phenomena. A basic two-level model of a
+saturable absorber displays all the effects normally associated with slow
+light, namely phase shift and modulation gain of the transmitted signal, hole
+burning in the modulation frequency spectrum and power broadening of the
+spectral hole, arising from the finite response time of the non-linear
+absorption. Only where hole-burning in the optical spectrum is observed (using
+independent pump and probe beams), or pulse delays exceeding the limits set by
+saturable absorption are obtained, can reasonable confidence be placed in the
+observation of slow light in such experiments. Superluminal ('fast light')
+phenomena in media with reverse saturable absorption (RSA) may be similarly
+explained.",0812.3076v1
+2009-01-19,BFKL and CCFM evolutions with saturation boundary,"We perform numerical studies of the BFKL and CCFM equations for the
+unintegrated gluon distribution supplemented with an absorptive boundary which
+mimics saturation. For the BFKL equation, this procedure yields the same
+results for the saturation momentum and the gluon distribution above saturation
+as the non-linear BK equation, for both fixed and running coupling, and for all
+the considered energies. This similarity goes beyond expectations based on the
+correspondence with statistical physics, which hold only for fixed coupling and
+asymptotically high energies. For the CCFM equation, whose non-linear
+generalization is not known, our method provides the first study of the
+approach towards saturation. We find that, in the running-coupling case, the
+CCFM and BFKL predictions for the energy dependence of the saturation momentum
+are identical within our numerical accuracy. A similar saturation boundary
+could be easily implemented in the CCFM-based Monte Carlo event generators, so
+like CASCADE.",0901.2873v1
+2010-07-28,Global Saturation of Regularization Methods for Inverse Ill-Posed Problems,"In this article the concept of saturation of an arbitrary regularization
+method is formalized based upon the original idea of saturation for spectral
+regularization methods introduced by A. Neubauer in 1994. Necessary and
+sufficient conditions for a regularization method to have global saturation are
+provided. It is shown that for a method to have global saturation the total
+error must be optimal in two senses, namely as optimal order of convergence
+over a certain set which at the same time, must be optimal (in a very precise
+sense) with respect to the error. Finally, two converse results are proved and
+the theory is applied to find sufficient conditions which ensure the existence
+of global saturation for spectral methods with classical qualification of
+finite positive order and for methods with maximal qualification. Finally,
+several examples of regularization methods possessing global saturation are
+shown.",1008.0108v1
+2011-05-10,"Gluon saturation and baryon stopping in the SPS, RHIC and LHC energy regions","A new geometrical scaling method with gluon saturation rapidity limit is
+proposed to study the gluon saturation feature of the central rapidity region
+of relativistic nuclear collisions. The net-baryon number is essentially
+transported by valence quarks that probe the saturation regime in the target by
+multiple scattering. We take advantage of the gluon saturation model with
+geometric scaling of the rapidity limit to investigate the net baryon
+distributions, nuclear stopping power and gluon saturation features in the SPS
+and RHIC energy regions. Predictions for net-baryon rapidity distributions, the
+mean rapidity loss and gluon saturation feature in central Pb + Pb collisions
+at LHC are made in this paper.",1105.1835v4
+2011-07-06,Next-to-leading and resummed BFKL evolution with saturation boundary,"We investigate the effects of the saturation boundary on small-x evolution at
+the next-to-leading order accuracy and beyond. We demonstrate that the
+instabilities of the next-to-leading order BFKL evolution are not cured by the
+presence of the nonlinear saturation effects, and a resummation of the higher
+order corrections is therefore needed for the nonlinear evolution. The
+renormalization group improved resummed equation in the presence of the
+saturation boundary is investigated, and the corresponding saturation scale is
+extracted. A significant reduction of the saturation scale is found, and we
+observe that the onset of the saturation corrections is delayed to higher
+rapidities. This seems to be related to the characteristic feature of the
+resummed splitting function which at moderately small values of x possesses a
+minimum.",1107.1252v1
+2012-10-16,Saturation-Dependence of Dispersion in Porous Media,"In this study, we develop a saturation-dependent treatment of dispersion in
+porous media using concepts from critical path analysis, cluster statistics of
+percolation, and fractal scaling of percolation clusters. We calculate spatial
+solute distributions as a function of time and calculate arrival time
+distributions as a function of system size. Our previous results correctly
+predict the range of observed dispersivity values over ten orders of magnitude
+in experimental length scale, but that theory contains no explicit dependence
+on porosity or relative saturation. This omission complicates comparisons with
+experimental results for dispersion, which are often conducted at saturation
+less than 1. We now make specific comparisons of our predictions for the
+arrival time distribution with experiments on a single column over a range of
+saturations. This comparison suggests that the most important predictor of such
+distributions as a function of saturation is not the value of the saturation
+per se, but the applicability of either random or invasion percolation models,
+depending on experimental conditions.",1210.4581v1
+2014-01-21,Impact of Dispersive and Saturable Gain/Loss on Bistability of Nonlinear Parity-Time Bragg Gratings,"We report on the impact of realistic gain and loss models on the bistable
+operation of nonlinear parity-time Bragg gratings. In our model we include both
+dispersive and saturable gain and show that levels of gain/loss saturation can
+have significant impact on the bistable operation of a nonlinear PT Bragg
+grating based on GaAs material. The hysteresis of the nonlinear PT Bragg
+grating is analyzed for different levels of gain and loss and different
+saturation levels. We show that high saturation levels can improve the
+nonlinear operation by reducing the intensity at which the bistability occurs.
+However when the saturation intensity is low, saturation inhibits the PT
+characteristics of the grating.",1401.5233v2
+2014-12-27,Analysis of Saturated Belief Propagation Decoding of Low-Density Parity-Check Codes,"We consider the effect of log-likelihood ratio saturation on belief
+propagation decoder low-density parity-check codes. Saturation is commonly done
+in practice and is known to have a significant effect on error floor
+performance. Our focus is on threshold analysis and stability of density
+evolution.
+  We analyze the decoder for standard low-density parity-check code ensembles
+and show that belief propagation decoding generally degrades gracefully with
+saturation. Stability of density evolution is, on the other hand, rather
+strongly effected by saturation and the asymptotic qualitative effect of
+saturation is similar to reduction by one of variable node degree.
+  We also show under what conditions the block threshold for the saturated
+belief propagation corresponds with the bit threshold.",1412.8090v1
+2017-05-27,Power System Supplementary Damping Controllers in the Presence of Saturation,"This paper presents the analysis and a method to design supplementary damping
+controllers (SDCs) for synchronous generators considering the effects of
+saturation limits. Usually such saturations of control signals are imposed in
+order to enforce practical limitations such as component ratings. However, to
+guarantee the stability in the presence of saturation limits, the state
+trajectories must remain inside the domain of attraction (DA). In this paper,
+the domain of attraction of a single-machine infinite-bus (SMIB) power system
+with saturation nonlinearity is estimated and compared with the exact
+description of the null controllable region. Then, state-feedback controllers
+are designed to enlarge the DA. Our analysis shows that nonlinear effects of
+saturation should be considered to guarantee stability and satisfactory
+performance. Simulation results on a detailed nonlinear model of a synchronous
+generator indicate that the DA enlarges with the proposed controller. The
+results also indicate that Critical Clearing Time (CCT) and damping of the
+system with saturation can be improved by the proposed method.",1705.09849v1
+2019-06-30,On countably saturated linear orders and certain class of countably saturated graphs,"The idea of this paper is to explore the existence of canonical countably
+saturated models for different classes of structures. It is well-known that,
+under CH, there exists a unique countably saturated linear order of cardinality
+$\mathfrak{c}$. We provide some examples of pairwise non-isomorphic countably
+saturated linear orders of cardinality $\mathfrak{c}$, under different
+set-theoretic assumptions. We give a new proof of the old theorem of Harzheim,
+that the class of countably saturated linear orders has a uniquely determined
+one-element basis. From our proof it follows that this minimal linear order is
+a Fra\""isse limit of certain Fra\""isse class. In particular, it is homogeneous
+with respect to countable subsets. Next, we prove the existence and uniqueness
+of the uncountable version of the random graph. This graph is isomorphic to
+$(H(\omega_1),\in \cup \ni)$, where $H(\omega_1)$ is the set of hereditarily
+countable sets, and two sets are connected if one of them is an element of the
+other. In the last section, an example of a prime countably saturated Boolean
+algebra is presented.",1907.00432v4
+2020-03-30,Rainbow Saturation,"We introduce a notion of rainbow saturation and the corresponding rainbow
+saturation number. This is the saturation version of the rainbow Tur\'an
+numbers whose systematic study was initiated by Keevash, Mubayi, Sudakov, and
+Verstra\""ete. We give examples of graphs for which the rainbow saturation
+number is bounded away from the ordinary saturation number. This includes all
+complete graphs $K_n$ for $n\geq 4$, and several bipartite graphs. It is
+notable that there are non-bipartite graphs for which this is the case, as this
+does not happen when it comes to the rainbow extremal number versus the
+traditional extremal number. We also show that saturation numbers are linear
+for a large class of graphs, providing a partial rainbow analogue of a well
+known theorem of K\'asonyi and Tuza. We conclude this paper with related open
+questions and conjectures.",2003.13200v2
+2020-12-31,Unified description of saturation and bistability of intersubband transitions in the weak and strong light-matter coupling regimes,"We propose a unified description of intersubband absorption saturation for
+quantum wells inserted in a resonator, both in the weak and strong light-matter
+coupling regimes. We demonstrate how absorption saturation can be engineered.
+In particular we show that the saturation intensity increases linearly with the
+doping in the strong coupling regime, while it remains doping independent in
+weak coupling. Hence, countering intuition, the most suitable region to exploit
+low saturation intensities is not the ultra-strong coupling regime, but is
+instead at the onset of the strong light-matter coupling. We further derive
+explicit conditions for the emergence of bistability. This work sets the path
+towards yet unexisting ultrafast mid-infrared semiconductor saturable
+absorption mirrors (SESAMs) and bistable systems. As an example, we show how to
+design a mid-infrared SESAM with a three orders of magnitude reduction in
+saturation intensity, down to about 5 kW/cm2.",2012.15633v3
+2022-03-09,Gym-saturation: an OpenAI Gym environment for saturation provers,"`gym-saturation` is an OpenAI Gym environment for reinforcement learning (RL)
+agents capable of proving theorems. Currently, only theorems written in a
+formal language of the Thousands of Problems for Theorem Provers (TPTP) library
+in clausal normal form (CNF) are supported. `gym-saturation` implements the
+'given clause' algorithm (similar to the one used in Vampire and E Prover).
+Being written in Python, `gym-saturation` was inspired by PyRes. In contrast to
+the monolithic architecture of a typical Automated Theorem Prover (ATP),
+`gym-saturation` gives different agents opportunities to select clauses
+themselves and train from their experience. Combined with a particular agent,
+`gym-saturation` can work as an ATP. Even with a non trained agent based on
+heuristics, `gym-saturation` can find refutations for 688 (of 8257) CNF
+problems from TPTP v7.5.0.",2203.04699v1
+2022-03-18,Optimizing Randomized and Deterministic Saturation Designs under Interference,"Randomized saturation designs are a family of designs which assign a possibly
+different treatment proportion to each cluster of a population at random. As a
+result, they generalize the well-known (stratified) completely randomized
+designs and the cluster-based randomized designs, which are included as special
+cases. We show that, under the stable unit treatment value assumption, either
+the cluster-based or the stratified completely randomized design are in fact
+optimal for the bias and variance of the difference-in-means estimator among
+randomized saturation designs. However, this is no longer the case when
+interference is present. We provide the closed form of the bias and variance of
+the difference-in-means estimator under a linear model of interference and
+investigate the optimization of each of these objectives. In addition to the
+randomized saturation designs, we propose a deterministic saturation design,
+where the treatment proportion for clusters are fixed, rather than randomized,
+in order to further improve the estimator under correct model specification.
+Through simulations, we illustrate the merits of optimizing randomized
+saturation designs to the graph and potential outcome structure, as well as
+showcasing the additional improvements yielded by well-chosen deterministic
+saturation designs.",2203.09682v1
+2023-06-17,Projective and external saturation problem for posets,"We introduce two variants of the poset saturation problem. For a poset $P$
+and the Boolean lattice $\mathcal{B}_n$, a family $\mathcal{F}$ of sets, not
+necessarily from $\mathcal{B}_n$, is \textit{projective $P$-saturated} if (i)
+it does not contain any strong copies of $P$, (ii) for any $G\in
+\mathcal{B}_n\setminus \mathcal{F}$, the family $\mathcal{F}\cup \{G\}$
+contains a strong copy of $P$, and (iii) for any two different
+$F,F'\in\mathcal{F}$ we have $F\cap[n]\neq F'\cap [n]$. Ordinary strongly
+$P$-saturated families, i.e., subfamilies $\mathcal{F}$ required to be from
+$\mathcal{B}_n$ satisfying (i) and (ii), automatically satisfy (iii) as they
+lie within $\mathcal{B}_n$. We study what phenomena are valid both for the
+ordinary saturation number $\mathrm{sat}^*(n,P)$ and the projective saturation
+number, the size of the smallest projective $P$-saturated family.
+  Note that the projective saturation number might differ for a poset and its
+dual. We also introduce an even more relaxed and symmetric version of poset
+saturation, \textit{external saturation}. We conjecture that all finite posets
+have bounded external saturation number, and prove this in some special cases.",2306.10387v1
+2023-06-29,Saturating linear sets of minimal rank,"Saturating sets are combinatorial objects in projective spaces over finite
+fields that have been intensively investigated in the last three decades. They
+are related to the so-called covering problem of codes in the Hamming metric.
+In this paper, we consider the recently introduced linear version of such sets,
+which is, in turn, related to the covering problem in the rank metric. The main
+questions in this context are how small the rank of a saturating linear set can
+be and how to construct saturating linear sets of small rank. Recently, Bonini,
+Borello, and Byrne provided a lower bound on the rank of saturating linear sets
+in a given projective space, which is shown to be tight in some cases. In this
+paper, we provide construction of saturating linear sets meeting the lower
+bound and we develop a link between the saturating property and the
+scatteredness of linear sets. The last part of the paper is devoted to show
+some parameters for which the bound is not tight.",2306.17081v2
+2023-12-02,Saturation results around the Erdős--Szekeres problem,"In this paper, we consider saturation problems related to the celebrated
+Erd\H{o}s--Szekeres convex polygon problem. For each $n \ge 7$, we construct a
+planar point set of size $(7/8) \cdot 2^{n-2}$ which is saturated for convex
+$n$-gons. That is, the set contains no $n$ points in convex position while the
+addition of any new point creates such a configuration. This demonstrates that
+the saturation number is smaller than the Ramsey number for the
+Erd\H{o}s--Szekeres problem. The proof also shows that the original
+Erd\H{o}s--Szekeres construction is indeed saturated.
+  Our construction is based on a similar improvement for the saturation version
+of the cups-versus-caps theorem. Moreover, we consider the generalization of
+the cups-versus-caps theorem to monotone paths in ordered hypergraphs. In
+contrast to the geometric setting, we show that this abstract saturation number
+is always equal to the corresponding Ramsey number.",2312.01223v1
+2010-10-11,Investigating coronal saturation and super-saturation in fast-rotating M-dwarf stars,"At fast rotation rates the coronal activity of G- and K-type stars has been
+observed to ""saturate"" and then decline again at even faster rotation rates --
+a phenomenon dubbed ""super-saturation"". In this paper we investigate coronal
+activity in fast-rotating M-dwarfs using deep XMM-Newton observations of 97
+low-mass stars of known rotation period in the young open cluster NGC 2547, and
+combine these with published X-ray surveys of low-mass field and cluster stars
+of known rotation period. Like G- and K-dwarfs, we find that M-dwarfs exhibit
+increasing coronal activity with decreasing Rossby number N_R, the ratio of
+period to convective turnover time, and that activity saturates at L_x/L_bol ~
+10^-3 for log N_R < -0.8. However, super-saturation is not convincingly
+displayed by M-dwarfs, despite the presence of many objects in our sample with
+log N_R < -1.8, where super-saturation is observed to occur in higher mass
+stars. Instead, it appears that a short rotation period is the primary
+predictor of super-saturation; P <=0.3d for K-dwarfs and perhaps P <=0.2d for
+M-dwarfs. These observations favour the ""centrifugal stripping"" model for
+super-saturation, where coronal structures are forced open or become
+radiatively unstable as the Keplerian co-rotation radius moves inside the X-ray
+emitting coronal volume.",1010.2152v1
+2017-03-20,A barotropic model of eddy saturation,"""Eddy saturation"" refers to a regime in which the total volume transport of
+an oceanic current is insensitive to the wind stress strength. Baroclinicity is
+currently believed to be key to the development of an eddy-saturated state. In
+this paper, it is shown that eddy saturation can also occur in a purely
+barotropic flow over topography, without baroclinicity. Thus, eddy saturation
+is a fundamental property of barotropic dynamics above topography. It is
+demonstrated that the main factor controlling the appearance or not of
+eddy-saturated states in the barotropic setting is the structure of geostrophic
+contours, that is the contours of $f/H$ of the ratio of the Coriolis parameter
+to the ocean's depth. Eddy-saturated states occur when the geostrophic contours
+are open, that is when the geostrophic contours span the whole zonal extent of
+the domain. This minimal requirement for eddy-saturated states is demonstrated
+using numerical integrations of a single-layer quasi-geostrophic flow over two
+different topographies characterized by either open or closed geostrophic
+contours with parameter values loosely inspired by the Southern Ocean. In this
+setting, transient eddies are produced through a barotropic-topographic
+instability that occurs due tot the interaction of the large-scale zonal flow
+with the topography. Through the study of this barotropic-topographic
+instability insight is gained on how eddy-saturated states are established.",1703.06594v4
+2018-03-16,Induced Saturation of Graphs,"A graph $G$ is $H$-saturated for a graph $H$, if $G$ does not contain a copy
+of $H$ but adding any new edge to $G$ results in such a copy. An $H$-saturated
+graph on a given number of vertices always exists and the properties of such
+graphs, for example their highest density, have been studied intensively. A
+graph $G$ is $H$-induced-saturated if $G$ does not have an induced subgraph
+isomorphic to $H$, but adding an edge to $G$ from its complement or deleting an
+edge from $G$ results in an induced copy of $H$. It is not immediate anymore
+that $H$-induced-saturated graphs exist. In fact, Martin and Smith (2012)
+showed that there is no $P_4$-induced-saturated graph. Behrens et.al. (2016)
+proved that if $H$ belongs to a few simple classes of graphs such as a class of
+odd cycles of length at least $5$, stars of size at least $2$, or matchings of
+size at least $2$, then there is an $H$-induced-saturated graph. This paper
+addresses the existence question for $H$-induced-saturated graphs. It is shown
+that Cartesian products of cliques are $H$-induced-saturated graphs for $H$ in
+several infinite families, including large families of trees. A complete
+characterization of all connected graphs $H$ for which a Cartesian product of
+two cliques is an $H$-induced-saturated graph is given. Finally, several
+results on induced saturation for prime graphs and families of graphs are
+provided.",1803.06244v1
+2023-07-17,"Varying quench dynamics in the transverse Ising chain: the Kibble-Zurek, saturated, and pre-saturated regimes","According to the Kibble-Zurek mechanism, there is a universal power-law
+relationship between the defect density and the quench rate during a slow
+linear quench through a critical point. It is generally accepted that a fast
+quench results in a deviation from the Kibble-Zurek scaling law and leads to
+the formation of a saturated plateau in the defect density. By adjusting the
+quench rate from slow to very fast limits, we observe the varying quench
+dynamics and identify a pre-saturated regime that lies between the saturated
+and Kibble-Zurek regimes. This significant result is elucidated through the
+adiabatic-impulse approximation first, then verified by a rigorous analysis on
+the transverse Ising chain as well. As we approach the turning point from the
+saturated to pre-saturated regimes, we notice a change in scaling laws and,
+with an increase in the initial transverse field, a shrinking of the saturated
+regime until it disappears. During another turning point from the Kibble-Zurek
+to pre-saturated regimes, we observe an attenuation of the dephasing effect and
+a change in the behavior of the kink-kink correlation function from a Gaussian
+decay to an exponential decay. Finally, the coherent many-body oscillation
+after quench exhibits different behaviors in the three regimes and shows a
+significant change of scaling behavior between the S and PS regimes.",2307.08599v3
+2005-04-26,The independent scattering approximation in the saturated regime,"We show that a saturable single-frequency elastic T-matrix approach to
+scattering of light by atoms agrees remarkably well with a master equation
+description in the regime of unsaturated atoms, or for large separation between
+the atoms. If the atoms are in each other's near-field and the saturation of
+the atoms is high enough, the two approaches yield different results.",0504673v1
+2000-10-05,Comments on parton saturation at small x in large nuclei,"It is argued that the gluon density introduced by A.Mueller in relation to
+the saturation phenomenon is different from the standardly defined one, which
+turned out to have a soliton-like form in the numerical calculations. It is
+shown that A.Mueller's densities obtained from the latter possess the same
+saturation properties as originally predicted.",0010041v1
+2003-09-17,Saturation regimes at LHC energies,"The effects of saturation and unitarization for hadron-hadron scattering at
+LHC energies are explored in several models. It is shown that different choices
+of saturation parameters lead to sizable differences in the energy dependence
+of total cross sections, and to dramatic changes in elastic differential cross
+sections.",0309194v1
+2004-01-19,Instanton-Driven Saturation at Small x,"We report on the interesting possibility of instanton-driven gluon saturation
+in lepton-nucleon scattering at small Bjorken-x. Our results crucially involve
+non-perturbative information from high-quality lattice simulations. The
+conspicuous, intrinsic instanton size scale < rho > ~ 0.5 fm, as known from the
+lattice, turns out to determine the saturation scale. A central result is the
+identification of the ``colour glass condensate'' with the QCD-sphaleron state.",0401137v1
+2006-07-11,"Color strings, pomeron shadowing and Color Glass Condensate","I review the problem of parton saturation and its implications through three
+in principal different approaches, but somewhat related: saturation in a
+geometrical approach, QCD saturation through the Color Glass Condensate and
+shadowing in a Pomeron approach.",0607120v1
+2000-01-28,Stabilization of Spatial Solitons by Gain Diffusion,"It is shown, that diffusion of saturated gain (e.g. diffusion of population
+inversion in lasers) causes, and/or enhances a modulational instability of
+generated light field. In case of a subcritical system (e.g. a laser with
+saturable absorber) the enhancement of the modulational instability stabilizes
+spatial solitons. These predictions are made for general nonlinear optical
+systems, and are illustrated by numerical simulation of lasers with saturable
+absorber.",0001064v1
+2005-10-07,From percolation to the Color Glass Condensate,"I review the problem of parton saturation and its implications through three
+in principal different approaches, but somewhat related: saturation in a
+geometrical approach, QCD saturation through the Color Glass Condensate and
+perturbative Pomeron approach with initial conditions. I also make some
+comments about how that could be related to a Quark Gluon Plasma formation.",0510026v1
+2007-06-15,Heavy Flavor Production in DGLAP improved Saturation Model,"The saturation model with DGLAP evolution is shown to give good description
+of the production of the charm and beauty quarks in deep inelastic scattering.
+The modifications of saturation properties caused by the presence of heavy
+quarks are also discussed.",0706.2276v1
+2008-07-07,Chirped-pulse oscillators: an impact of the dynamic gain saturation,"An effect of the dynamic gain saturation on chirped-pulse oscillator was
+investigated. It was found, that the dynamic gain saturation causes strong
+perturbations of the pulse front that destabilizes an oscillator. As a result,
+the chirped-pulse exists only within some limited range of dispersions and
+there is a limit of energy growth for a given resonator period.",0807.1050v1
+2009-03-20,Saturation and linear transport equation,"We show that the GBW saturation model provides an exact solution to the one
+dimensional linear transport equation. We also show that it is motivated by the
+BK equation considered in the saturated regime when the diffusion and the
+splitting term in the diffusive approximation are balanced by the nonlinear
+term.",0903.3521v2
+2010-07-28,Introduction to the Physics of Saturation,"We present a brief introduction to the physics of parton saturation/Color
+Glass Condensate (CGC).",1007.5021v1
+2010-09-09,Saturation effects in QCD from linear transport equation,"We show that the GBW saturation model provides an exact solution to the
+one-dimensional linear transport equation. We also show that it is motivated by
+the BK equation considered in the saturated regime when the diffusion and the
+splitting term in the diffusive approximation are balanced by the nonlinear
+term.",1009.1757v1
+2012-08-25,Remark on the coherent information saturating its upper bound,"Coherent information is a useful concept in quantum information theory. It
+connects with other notions in data processing. In this short remark, we
+discuss the coherent information saturating its upper bound. A necessary and
+sufficient condition for this saturation is derived.",1208.5101v2
+2012-12-31,A valuation theoretic characterization of recursively saturated real closed fields,"We give a valuation theoretic characterization for a real closed field to be
+recursively saturated. Our result extends the characterization of Harnik and
+Ressayre \cite{hr} for a divisible ordered abelian group to be recursively
+saturated.",1212.6842v1
+2014-05-09,Sandwiching saturation number of fullerene graphs,"The saturation number of a graph $G$ is the cardinality of any smallest
+maximal matching of $G$, and it is denoted by $s(G)$. Fullerene graphs are
+cubic planar graphs with exactly twelve 5-faces; all the other faces are
+hexagons. They are used to capture the structure of carbon molecules. Here we
+show that the saturation number of fullerenes on $n$ vertices is essentially
+$n/3$.",1405.2197v1
+2016-04-19,Black Hole Spindown by Light Bosons,"The saturation mechanism for the fastest-growing instability of massive
+scalar field in Kerr metric is identified, assuming saturation by cubic or
+quartic nonlinearities of the field potential. The resulting spindown rate of
+the black hole is calculated. The (rather involved) saturation scenario is
+confirmed by numerical simulations.",1604.06422v1
+2016-07-14,Saturation and geometrical scaling in small systems,"Saturation and geometrical scaling (GS) of gluon distributions are a
+consequence of the non-linear evolution equations of QCD. We argue that in pp
+GS holds for the inelastic cross-section rather than for the multiplicity
+distributions. We also discuss possible fluctuations of the proton saturation
+scale in pA collisions at the LHC.",1607.04235v1
+2016-10-01,On cohomology of saturated fusion systems and support varieties,"In this short note we study the cohomology algebra of saturated fusion
+systems using finite groups which realize saturated fusion systems and
+Hochschild cohomology of group algebras. A similar result to a theorem of
+Alperin is proved for varieties of cohomology algebras of fusions systems
+associated to block algebras of finite groups.",1610.00095v2
+2017-01-11,Saturation rank for finite group schemes: Finite groups and Infinitesimal group schemes,"We investigate the saturation rank of a finite group scheme, defined over an
+algebraically closed field $\Bk$ of positive characteristic $p$. We begin by
+exploring the saturation rank for finite groups and infinitesimal group
+schemes. Special attention is given to reductive Lie algebras and the second
+Frobenius kernel of the algebraic group $\SL_{n}$.",1701.02951v1
+2017-08-09,Weak saturation and weak amalgamation property,"The two model-theoretic concepts of weak saturation and weak amalgamation
+property are studied in the context of accessible categories. We relate these
+two concepts providing sufficient conditions for existence and uniqueness of
+weakly saturated objects of an accessible category K. We discuss the
+implications of this fact in classical model theory.",1708.02738v2
+2017-08-28,Periodic groups saturated with finite simple groups of lie type rank 1,"In the Kourovka notebook the following question is posed 14.101:
+  Is it true that a periodic group saturated with finite simple groups of Lie
+type whose ranks are bounded in the aggregate, is itself a simple group of Lie
+type?
+  In this paper we give a partial answer to this question for periodic groups
+saturated by finite simple groups of Lie type rank 1.",1708.08181v1
+2017-12-10,"Asymptotics of Chebyshev Polynomials, III. Sets Saturating SzegŐ, Schiefermayr, and Totik--Widom Bounds","We determine which sets saturate the Szeg}o and Schiefermayr lower bounds on
+the norms of Chebyshev Polynomials. We also discuss sets that saturate the
+Totik--Widom upper bound.",1712.03482v1
+2019-03-08,"Decomposability, Convexity and Continuous Linear Operators in $L^1(μ,E)$: The Case for Saturated Measure Spaces","Motivated by the Lyapunov convexity theorem in infinite dimensions, we extend
+the convexity of the integral of a decomposable set to separable Banach spaces
+under the strengthened notion of nonatomicity of measure spaces, called
+""saturation"", and provide a complete characterization of decomposability in
+terms of saturation.",1903.04301v1
+2021-04-02,Saturation bounds for smooth varieties,"We prove bounds on the saturation degrees of homogeneous ideals (and their
+powers) defining smooth complex projective varieties. For example, we show that
+a classical statement due to Macualay for zero-dimensional complete
+intersection ideals holds for any smooth variety. For curves, we bound the
+saturation degree of powers in terms of the regularity.",2104.01218v1
+2022-03-17,Obstructions to countable saturation in corona algebras,"We study the extent of countable saturation for coronas of abelian
+C*-algebras. In particular, we show that the corona algebra of $C_0(\bbR^n)$ is
+countably saturated if and only if $n=1$.",2203.09351v2
+2007-10-17,Simultaneous Multi-Wavelength Observations of Magnetic Activity in Ultracool Dwarfs. II. Mixed Trends in VB10 and LSR1835+32 and the Possible Role of Rotation,"[Abridged] As part of our on-going investigation of magnetic activity in
+ultracool dwarfs we present simultaneous radio, X-ray, UV, and optical
+observations of LSR1835+32 (M8.5), and simultaneous X-ray and UV observations
+of VB10 (M8), both with a duration of about 9 hours. LSR1835+32 exhibits
+persistent radio emission and H-alpha variability on timescales of ~0.5-2 hr.
+The detected UV flux is consistent with photospheric emission, and no X-ray
+emission is detected to a deep limit of L_X/L_bol<10^-5.7. The H-alpha and
+radio emission are temporally uncorrelated, and the ratio of radio to X-ray
+luminosity exceeds the correlation seen in F-M6 stars by >2x10^4. Similarly,
+L_Halpha/L_X>10 is at least 30 times larger than in early M dwarfs, and
+eliminates coronal emission as the source of chromospheric heating. The lack of
+radio variability during four rotations of LSR1835+32 requires a uniform
+stellar-scale field of ~10 G, and indicates that the H-alpha variability is
+dominated by much smaller scales, <10% of the chromospheric volume. VB10, on
+the other hand, shows correlated flaring and quiescent X-ray and UV emission,
+similar to the behavior of early M dwarfs. Delayed and densely-sampled optical
+spectra exhibit a similar range of variability amplitudes and timescales to
+those seen in the X-rays and UV, with L_Halpha/L_X~1. Along with our previous
+observations of the M8.5 dwarf TVLM513-46546 we conclude that late M dwarfs
+exhibit a mix of activity patterns, which points to a transition in the
+structure and heating of the outer atmosphere by large-scale magnetic fields.
+We find that rotation may play a role in generating the fields as evidenced by
+a tentative correlation between radio activity and rotation velocity. The X-ray
+emission, however, shows evidence for super-saturation at vsini>25 km/s.",0710.3383v1
+2009-08-19,Long-term monitoring in IC4665: Fast rotation and weak variability in very low mass objects,"We present the combined results of three photometric monitoring campaigns
+targeting very low mass (VLM) stars and brown dwarfs in the young open cluster
+IC4665 (age ~40 Myr). In all three runs, we observe ~100 cluster members,
+allowing us for the first time to put limits on the evolution of spots and
+magnetic activity in fully convective objects on timescales of a few years. For
+20 objects covering masses from 0.05 to 0.5 Msol we detect a periodic flux
+modulation, indicating the presence of magnetic spots co-rotating with the
+objects. The detection rate of photometric periods (~20%) is significantly
+lower than in solar-mass stars at the same age, which points to a mass
+dependence in the spot properties. With two exceptions, none of the objects
+exhibit variability and thus spot activity in more than one season. This is
+contrary to what is seen in solar-mass stars and indicates that spot
+configurations capable of producing photometric modulations occur relatively
+rarely and are transient in VLM objects. The rotation periods derived in this
+paper range from 3 to 30h, arguing for a lack of slow rotators among VLM
+objects. The periods fit into a rotational evolution scenario with pre-main
+sequence contraction and moderate (40-50%) angular momentum losses due to wind
+braking. By combining our findings with literature results, we identify two
+regimes of rotational and magnetic properties, called C- and I-sequence. Main
+properties on the C-sequence are fast rotation, weak wind braking, Halpha
+emission, and saturated activity levels, while the I-sequence is characterised
+by slow rotation, strong wind braking, no Halpha emission, and linear
+activity-rotation relationship. Rotation rate and stellar mass are the primary
+parameters that determine in which regime an object is found. (abridged)",0908.2811v1
+2009-11-27,Shaken and stirred: conduction and turbulence in clusters of galaxies,"(abridged) Uninhibited radiative cooling in clusters of galaxies would lead
+to excessive mass accretion rates contrary to observations. One of the key
+proposals to offset radiative energy losses is thermal conduction from outer,
+hotter layers of cool core clusters to their centers. However, conduction is
+sensitive to magnetic field topology. In cool-core clusters the heat buoyancy
+instability (HBI) leads to B-fields ordered preferentially in the direction
+perpendicular to that of gravity, which significantly reduces the level of
+conduction below the classical Spitzer-Braginskii value. However, the cluster
+cool cores are rarely in perfect hydrostatic equilibrium. Sloshing motions due
+to minor mergers, galaxy motions or AGN can significantly perturb the gas and
+affect the level of thermal conduction. We perform 3D AMR MHD simulations of
+the effect of turbulence on the properties of the anisotropic thermal
+conduction in cool core clusters. We show that very weak subsonic motions, well
+within observational constraints, can randomize the magnetic field and
+significantly boost effective thermal conduction beyond the saturated values
+expected in the pure unperturbed HBI case. We find that the turbulent motions
+can essentially restore the conductive heat flow to the cool core to level
+comparable to the theoretical maximum of 1/3 Spitzer for a highly tangled
+field. Runs with radiative cooling show that the cooling catastrophe can be
+averted and the cluster core stabilized. Above a critical Froude number, these
+same turbulent motions also eliminate the tangential bias in the velocity and
+magnetic field that is otherwise induced by the trapped g-modes. Our results
+can be tested with future radio polarization measurements, and have
+implications for efficient metal dispersal in clusters.",0911.5198v2
+2010-05-26,CeRu$_4$Sn$_6$: heavy fermions emerging from a Kondo-insulating state,"The combination of low-temperature specific-heat and
+nuclear-magnetic-resonance (NMR) measurements reveals important information of
+the ground-state properties of CeRu$_4$Sn$_6$, which has been proposed as a
+rare example of a tetragonal Kondo-insulator (KI). The NMR
+spin-latticerelaxation rate $1/T_1$ deviates from the Korringa law below 100 K
+signaling the onset of an energy gap $\Delta E_g1/k_B \simeq 30$K. This gap is
+stable against magnetic fields up to 10 T. Below 10 K, however, unusual
+low-energy excitations of in-gap states are observed, which depend strongly on
+the field H. The specific heat C detects these excitations in the form of an
+enhanced Sommerfeld coefficient $\gamma = C(T)/T$ : In zero field, $\gamma$
+increases steeply below 5 K, reaching a maximum at 0.1 K, and then saturates at
+$\gamma = 0.6$ J/molK$^2$. This maximum is shifted to higher temperatures with
+increasing field suggesting a residual density of states at the Fermi level
+developing a spin gap $\Delta E_g2$. A simple model, based on two narrow
+quasiparticle bands located at the Fermi level - which cross the Fermi level in
+zero field at 0.022 states/meV f.u. - can account qualitatively as well as
+quantitatively for the measured observables. In particular, it is demonstrated
+that fitting our data of both specific heat and NMR to the model, incorporating
+a Ce magnetic moment of $\mu = \Delta E_g1/\mu_{0H} \simeq 1 \mu_B$, leads to
+the prediction of the field dependence of the gap. Our measurements rule out
+the presence of a quantum critical point as the origin for the enhanced
+$\gamma$ in CeRu$_4$Sn$_6$ and suggest that this arises rather from correlated,
+residual in-gap states at the Fermi level. This work provides a fundamental
+route for future investigations into the phenomenon of narrow-gap formation in
+the strongly correlated class of system",1005.4912v1
+2011-03-18,Hall diffusion and the magnetorotational instability in protoplanetary discs,"The destabilising effect of Hall diffusion in a Keplerian disc allows the MRI
+to occur for much lower ionisation levels than would otherwise be possible.
+However, simulations suggest that the consequences for the saturated state are
+not as significant as suggested by the linear instability. Close inspection
+reveals that that the simulations have not yet probed the Hall-dominated
+regime. Here we revisit the effect of Hall diffusion on the MRI and the
+implications for the extent of MHD turbulence in protoplanetary discs.
+  We conduct a local stability analysis for a vertical, weak magnetic field
+subject to axisymmetric perturbations with a vertical wave vector. The
+diffusivity dependence is presented using analytic expressions and contours in
+the eta_H - eta_P plane for the maximum growth rate and corresponding wave
+number, the upper cut-off for unstable wave numbers, and the loci that divide
+the plane into regions of different characteristic behaviour. In the
+highly-diffusive limit the magnetic field decouples from the fluid
+perturbations and the diffusive MRI reduces to a diffusive plane-parallel shear
+instability with effective shear rate 1.5 Omega. We give analytic expressions
+for the growth rate and wave number of the most unstable mode.
+  Finally, we illustrate the critical effect of Hall diffusion on the extent of
+dead zones in protoplanetary discs by applying a local stability criterion to a
+simple model of the minimum-mass solar nebula at 1 au, including x-ray and
+cosmic-ray ionisation and a population of 1 micron grains. Hall diffusion
+increases or decreases the MRI-active column density by an order of magnitude
+or more, depending on whether B is parallel or antiparallel to the rotation
+axis, respectively. Existing estimates of the depth of magnetically active
+layers in protoplanetary discs are likely to be wildly inaccurate.
+  [Abridged]",1103.3562v2
+2011-06-14,Disorder-dependent superconducting phase-diagram at high magnetic fields in Fe$_{1 + y}$Se$_{x}$Te$_{1-x}$ ($x \sim 0.4$),"We compare the superconducting phase-diagram under high magnetic fields (up
+to $H = 45$ T) of Fe$_{1+y}$Se$_{0.4}$Te$_{0.6}$ single crystals originally
+grown by the Bridgman-Stockbarger (BRST) technique, which were annealed to
+display narrow superconducting transitions and the optimal transition
+temperature $T_c \gtrsim 14$ K, with the diagram for samples of similar
+stoichiometry grown by the traveling-solvent floating-zone technique as well as
+with the phase-diagram reported for crystals grown by a self-flux method. We
+find that the so-annealed samples tend to display higher ratios $H_{c2}/T_c$,
+particularly for fields applied along the inter-planar direction, where the
+upper critical field $H_{c2}(T)$ exhibits a pronounced downward curvature
+followed by saturation at lower temperatures $T$. This last observation is
+consistent with previous studies indicating that this system is Pauli limited.
+An analysis of our $H_{c2}(T)$ data using a multiband theory suggests the
+emergence of the Farrel-Fulde-Larkin-Ovchnikov state at low temperatures. A
+detailed structural x-ray analysis, reveals no impurity phases but an
+appreciable degree of mosaicity in as-grown BRST single-crystals which remains
+unaffected by the annealing process. Energy-dispersive x-ray analysis showed
+that the annealed samples have a more homogeneous stoichiometric distribution
+of both Fe and Se with virtually the same content of interstitial Fe as the
+non-annealed ones. Thus, we conclude that stoichiometric disorder, in contrast
+to structural disorder, is detrimental to the superconducting phase diagram of
+this series under high magnetic fields. Finally, a scaling analysis of the
+fluctuation conductivity in the superconducting critical regime, suggests that
+the superconducting fluctuations have a two-dimensional character in this
+system.",1106.2818v2
+2012-12-21,Nuclei in Strongly Magnetised Neutron Star Crusts,"We discuss the ground state properties of matter in outer and inner crusts of
+neutron stars under the influence of strong magnetic fields. In particular, we
+demonstrate the effects of Landau quantization of electrons on compositions of
+neutron star crusts. First we revisit the sequence of nuclei and the equation
+of state of the outer crust adopting the Baym, Pethick and Sutherland (BPS)
+model in the presence of strong magnetic fields and most recent versions of the
+theoretical and experimental nuclear mass tables. Next we deal with nuclei in
+the inner crust. Nuclei which are arranged in a lattice, are immersed in a
+nucleonic gas as well as a uniform background of electrons in the inner crust.
+The Wigner-Seitz approximation is adopted in this calculation and each lattice
+volume is replaced by a spherical cell. The coexistence of two phases of
+nuclear matter - liquid and gas, is considered in this case. We obtain the
+equilibrium nucleus corresponding to each baryon density by minimizing the free
+energy of the cell. We perform this calculation using Skyrme nucleon-nucleon
+interaction with different parameter sets. We find nuclei with larger mass and
+charge numbers in the inner crust in the presence of strong magnetic fields
+than those of the zero field case for all nucleon-nucleon interactions
+considered here. However, SLy4 interaction has dramatic effects on the proton
+fraction as well as masses and charges of nuclei. This may be attributed to the
+behaviour of symmetry energy with density in the sub-saturation density regime.
+Further we discuss the implications of our results to shear mode oscillations
+of magnetars.",1212.5348v1
+2013-02-28,Rayleigh-Taylor Instability in a Relativistic Fireball on a Moving Computational Grid,"We numerically calculate the growth and saturation of the Rayleigh-Taylor
+instability caused by the deceleration of relativistic outflows with Lorentz
+factor {\Gamma} = 10, 30, and 100. The instability generates turbulence whose
+scale exhibits strong dependence on Lorentz factor, as only modes with angular
+size smaller than 1/{\Gamma} can grow. We develop a simple diagnostic to
+measure the kinetic energy in turbulent fluctuations, and calculate a ratio of
+turbulent kinetic energy to thermal energy of .03 in the region affected by the
+instability. Although our numerical calculation does not include magnetic
+fields, we argue that small scale turbulent dynamo amplifies magnetic fields to
+nearly this same fraction, giving a ratio of magnetic to thermal energy of ~
+.01, to within a factor of two. The instability completely disrupts the contact
+discontinuity between the ejecta and the swept up circumburst medium. The
+reverse shock is stable, but is impacted by the Rayleigh-Taylor instability,
+which strengthens the reverse shock and pushes it away from the forward shock.
+The forward shock front is unaffected by the instability, but Rayleigh-Taylor
+fingers can penetrate of order 10% of the way into the energetic region behind
+the shock during the two-shock phase of the explosion. We calculate afterglow
+emission from the explosion and find the reverse shock emission peaks at a
+later time due to its reduced Lorentz factor and modified density and pressure
+at the shock front. These calculations are performed using a novel numerical
+technique that includes a moving computational grid. The moving grid is
+essential as it maintains contact discontinuities to high precision and can
+easily evolve flows with extremely large Lorentz factors.",1302.7306v3
+2014-05-01,Theory of Bosons in two-leg ladders with large magnetic fields,"We calculate the ground state of a Bose gas trapped on a two-leg ladder where
+Raman-induced hopping mimics the effect of a large magnetic field. In the
+mean-field limit, where there are large numbers of particles per site, this
+maps onto a uniformly frustrated two-leg ladder classical spin model. The net
+particle current always vanishes in the ground state, but generically there is
+a finite ""chiral current"", corresponding to equal and opposite flow on the two
+legs. We vary the strength of the hopping across the rungs of the ladder and
+the interaction between the bosons. We find three phases: (1) A ""saturated
+chiral current phase"" (SCCP), where the density is uniform and the chiral
+current is simply related to the strength of the magnetic field. In this state
+the only broken symmetry is the $U(1)$ condensate phase. (2) A ""biased ladder
+phase"" (BLP), where the density is higher on one leg than the other. The fluid
+velocity is higher on the lower density leg, so the net current is zero. In
+addition to the $U(1)$ condensate phase, this has a broken $Z_2$ reflection
+symmetry. (3) A ""modulated density phase"" (MDP), where the atomic density is
+modulated along the ladder. In addition to the $U(1)$ condensate phase, this
+has a second broken $U(1)$ symmetry corresponding to translations of the
+density wave. We further study the fluctuations of the condensate in the BLP,
+finding a roton-maxon like excitation spectrum. Decreasing the hopping along
+the rungs softens the spectrum. As the energy of the ""roton"" reaches to zero,
+the BLP becomes unstable. We describe the experimental signatures of these
+phases, including the response to changing the frequency of the Raman
+transition.",1405.0230v1
+2014-08-21,On the radiation driven alignment of dust grains: Detection of the polarization hole in a starless core,"We aim to investigate the polarization properties of a starless core in a
+very early evolutionary stage. Linear polarization data reveal the properties
+of the dust grains in the distinct phases of the interstellar medium. Our goal
+is to investigate how the polarization degree and angle correlate with the
+cloud and core gas. We use optical, near infrared and submillimeter
+polarization observations toward the starless object Pipe-109 in the Pipe
+nebula. Our data cover a physical scale range of 0.08 to 0.4 pc, comprising the
+dense gas, envelope and the surrounding cloud. The cloud polarization is well
+traced by the optical data. The near infrared polarization is produced by a
+mixed population of grains from the core border and the cloud gas. The optical
+and near infrared polarization toward the cloud reach the maximum possible
+value and saturate with respect to the visual extinction. The core polarization
+is predominantly traced by the submillimeter data and have a steep decrease
+with respect to the visual extinction. Modeling of the submillimeter
+polarization indicates a magnetic field main direction projected onto the
+plane-of-sky and loss of grain alignment for densities higher than
+$6\times10^4$ cm$^{-3}$ (or $A_V > 30$ mag). Pipe-109 is immersed in a
+magnetized medium, with a very ordered magnetic field. The absence of internal
+source of radiation significantly affects the polarization efficiencies in the
+core, creating a polarization hole at the center of the starless core. This
+result supports the theory of dust grain alignment via radiative torques.",1408.5133v1
+2015-07-16,On the role of tachoclines in solar and stellar dynamos,"Rotational shear layers at the boundary between radiative and convective
+zones, tachoclines, play a key role in the process of magnetic field generation
+in solar-like stars. We present two sets of global simulations of rotating
+turbulent convection and dynamo. The first set considers a stellar convective
+envelope only; the second one, aiming at the formation of a tachocline,
+considers also the upper part of the radiative zone. Our results indicate that
+the resulting mean-flows and dynamo properties like the growth rate, saturation
+energy and mode depend on the Rossby (Ro) number. For the first set of models
+either oscillatory (with ~2 yr period) or steady dynamo solutions are obtained.
+The models in the second set naturally develop a tachocline which, in turn,
+leads to the generation of strong mean magnetic field. Since the field is also
+deposited into the stable deeper layer, its evolutionary time-scale is much
+longer than in the models without a tachocline. Surprisingly, the magnetic
+field in the upper turbulent convection zone evolves in the same time scale as
+the deep field. These models result in either an oscillatory dynamo with ~30 yr
+period or in a steady dynamo depending on Ro. In terms of the mean-field dynamo
+coefficients computed using FOSA, the field evolution in the oscillatory models
+without a tachocline seems to be consistent with dynamo waves propagating
+according to the Parker-Yoshimura sign rule. In the models with tachoclines the
+dynamics is more complex involving other transport mechanisms as well as
+tachocline instabilities.",1507.04434v3
+2015-08-08,Direct comparison of domain wall behavior in Permalloy nanowires patterned by electron beam lithography and focused ion beam milling,"Nominally identical permalloy nanowires, with widths down to 150 nm, were
+fabricated onto a single electron transparent Si$_{3}$N$_{4}$ membrane using
+electron beam lithography (EBL) and focused ion beam (FIB) milling.
+Transmission electron microscopy (TEM) experiments were performed to compare
+the nanostructures produced by these two techniques in what we believe is the
+first direct comparison of fabrication techniques for nominally identical
+nanowires. Both EBL and FIB methods produced high quality structures with edge
+roughness being of the order of the mean grain size 5 -10 nm observed in the
+continuous films. However, significant grain growth was observed along the
+edges of the FIB patterned nanowires. Lorentz TEM \emph{in situ} imaging was
+carried out to compare the magnetic behavior of the domain walls in the
+patterned nanowires with anti-notches present to pin domain walls. The overall
+process of domain wall pinning and depinning at the anti-notches showed
+consistent behaviour between nanowires fabricated by the two methods with the
+FIB structures having slightly lower characteristic fields compared to the EBL
+wires. However, a significant difference was observed in the formation of a
+vortex structure inside the anti-notches of the EBL nanowires after depinning
+of the domain walls. No vortex structure was seen inside the anti-notches of
+the FIB patterned nanowires. Results from micromagnetic simulations suggest
+that the vortex structure inside the anti-notch can be suppressed if the
+saturation magnetization (M$_{s}$) is reduced along the nanowires edges. Whilst
+the two fabrication methods show that well defined structures can be produced
+for the dimensions considered here, the differences in the magnetic behavior
+for nominally identical structures may be an issue if such structures are to be
+used as conduits for domain walls in potential memory and logic applications.",1508.01910v1
+2015-12-09,"Standard model of the rare-earths, analyzed from the Hubbard I approximation","In this work we examine critically the electronic structure of the rare-earth
+elements by use of the so-called Hubbard I approximation. From the theoretical
+side all measured features of both occupied and unoccupied states are
+reproduced, without significant deviations between observations and theory. We
+also examine cohesive properties like the equilibrium volume and bulk modulus,
+where we find, in general, a good agreement between theory and measurements. In
+addition we have reproduced the spin and orbital moments of these elements, as
+they are reflected from measurements of the saturation moment. We have also
+employed the Hubbard I approximation to extract the interatomic exchange
+parameters of an effective spin Hamiltonian for the heavy rare earths. We show
+that the Hubbard I approximation gives results which are consistent with
+calculations where $4f$ electrons are treated as core states for Gd. The latter
+approach was also used to address the series of the heavy/late rare-earths. Via
+Monte Carlo simulations we obtained ordering temperatures which reproduce
+measurements within about $20\%$. We have further illustrated the accuracy of
+these exchange parameters by comparing measured and calculated magnetic
+configurations for the heavy rare earths and the magnon dispersion for Gd. The
+Hubbard I approximation is compared to other theories of the electronic
+structure, and we argue that it is superior. We discuss the relevance of our
+results in general, and how this makes it possible to treat the electronic
+structure of materials containing rare-earth elements, such as permanent
+magnets, magnetostrictive compounds, photovoltaics, optical fibers, topological
+insulators, and molecular magnets.",1512.02848v2
+2017-02-18,At the limits of criticality-based quantum metrology: apparent super-Heisenberg scaling revisited,"We address the question whether the super-Heisenberg scaling for quantum
+estimation is realizable. We unify the results of two approaches. In the first
+one, the original system is compared with its copy rotated by the parameter
+dependent dynamics. If the parameter is coupled to the one-body part of the
+Hamiltonian the precision of its estimation is known to scale at most as
+$N^{-1}$ (Heisenberg scaling) in terms of the number of elementary subsystems
+used, $N$. The second approach considers fidelity at criticality often leading
+to an apparent super-Heisenberg scaling. However, scaling of time needed to
+ensure adiabaticity of the evolution brings back the the Heisenberg limit. We
+illustrate the general theory on a ferromagnetic Heisenberg spin chain which
+exhibits such super-Heisenberg scaling of fidelity around the critical value of
+the magnetic field. Even an elementary estimator represented by a single-site
+magnetization already outperforms the Heisenberg behavior providing the
+$N^{-1.5}$ scaling. In this case Fisher information sets the ultimate scaling
+as $N^{-1.75}$ which can be saturated by measuring magnetization on all sites
+simultaneously. We discuss universal scaling predictions of the estimation
+precision offered by such observables, both at zero and finite temperatures,
+and support them with numerical simulations in the model. We provide an
+experimental proposal of realization of the considered model via mapping the
+system to ultra-cold bosons in periodically shaken optical lattice. We
+explicitly derive that the Heisenberg limit is recovered when time needed for
+preparation of quantum states involved is taken into acocunt.",1702.05660v3
+2017-06-05,Robust techniques for polarization and detection of nuclear spin ensembles,"Highly sensitive nuclear spin detection is crucial in many scientific areas
+including nuclear magnetic resonance spectroscopy (NMR), imaging (MRI) and
+quantum computing. The tiny thermal nuclear spin polarization represents a
+major obstacle towards this goal which may be overcome by Dynamic Nuclear Spin
+Polarization (DNP) methods. The latter often rely on the transfer of the
+thermally polarized electron spins to nearby nuclear spins, which is limited by
+the Boltzmann distribution of the former. Here we demonstrate the polarization
+and read out of a nuclear spin bath consisting of $^{13}$C nuclear spins in
+diamond by using a single nitrogen-vacancy (NV) center. Our method utilizes
+microwave dressed states to transfer the NV's high ($>$~92~\%) non-equilibrium
+electron spin polarization induced by short laser pulses to the surrounding
+carbon nuclear spins, where the NV is repeatedly repolarized optically, thus
+providing an effectively infinite polarization reservoir. A saturation of the
+polarization in the nuclear ""frozen core"" is achieved, which is confirmed by
+the decay of the polarization transfer signal and shows an excellent agreement
+with theoretical simulations. Hereby we introduce the Polarization Read Out by
+Polarization Inversion (PROPI) method as a quantitative magnetization measure
+of the nuclear spin bath. Moreover, we show that using the integrated solid
+effect both for single and double quantum transitions a nuclear spin
+polarization can be achieved even when the static magnetic field is not aligned
+along the NV's crystal axis. This opens a path for the application of our DNP
+technique to spins in and outside of nanodiamonds, enabling their application
+as MRI tracers.",1706.01315v2
+2017-08-06,Comparative analysis of magnetic resonance in the polaron pair recombination and the triplet exciton-polaron quenching models,"We present a comparative theoretical study of magnetic resonance within the
+polaron pair recombination (PPR) and the triplet exciton-polaron quenching
+(TPQ) models. Both models have been invoked to interpret the photoluminescence
+detected magnetic resonance (PLDMR) in $\pi$-conjugated materials. We show that
+resonance lineshapes calculated within the two models differ dramatically in
+several regards. First, in the PPR model, the lineshape exhibits unusual
+behavior upon increasing the microwave power: it evolves from fully positive at
+weak power to fully negative at strong power. In contrast, in the TPQ model,
+the PLDMR is completely positive, showing a monotonic saturation. Second, the
+two models predict different dependencies of the resonance signal on the
+photoexcitation power, $P_L$. At low $P_L$, the resonance amplitude $\Delta
+I/I$ is $\propto P_L$ in the PPR model, while it is $\propto P_L^2$ crossing
+over to $P_L^3$ in the TPQ model. On the physical level, the differences stem
+from different underlying spin dynamics. Most prominently, a negative resonance
+within the PPR model has its origin in the microwave-induced spin-Dicke effect,
+leading to the resonant quenching of photoluminescence. The spin-Dicke effect
+results from the spin-selective recombination, resulting in a highly correlated
+precession of the on-resonance pair-partners under the strong microwave power.
+This effect is not relevant to TPQ, where the majority of triplets are
+off-resonance due to the strong zero-field splitting. The analytical evaluation
+of lineshapes for the two models is enabled by expressing these shapes via the
+eigenvalues of a complex Hamiltonian. This bypasses the necessity of solving
+the much larger complex system of stochastic Liouville equations. Our findings
+pave the way towards a reliable discrimination between the two mechanisms via
+cw PLDMR.",1708.01917v1
+2017-11-21,Quantum correlations in periodically driven spin chains: Revivals and steady-state properties,"We study the dynamics of microscopic quantum correlations, viz., bipartite
+entanglement and quantum discord between nearest neighbor sites, in Ising spin
+chain with a periodically varying external magnetic field along the transverse
+direction. Quantum correlations exhibit periodic revivals with the driving
+cycles in the finite-size chain. The time of first revival is proportional to
+the system size and is inversely proportional to the maximum group velocity of
+Floquet quasi-particles. On the other hand, the local quantum correlations in
+the infinite chain may get saturated to non-zero values after a sufficiently
+large number of driving cycles. Moreover, we investigate the convergence of
+local density matrices, from which the quantum correlations under study
+originate, towards the final steady-state density matrices as a function of
+driving cycles. We find that the geometric distance, $d$, between the reduced
+density matrices of non-equilibrium state and steady-state obeys a power-law
+scaling of the form $d \sim n^{-B}$, where $n$ is the number of driving cycles
+and $B$ is the scaling exponent. The steady-state quantum correlations are
+studied as a function of time period of the driving field and are marked by the
+presence of prominent peaks in frequency domain. The steady-state features can
+be further understood by probing band structures of Floquet Hamiltonian and
+purity of the bipartite state between nearest neighbor sites. Finally, we
+compare the steady-state values of the local quantum correlations with that of
+the canonical Gibbs ensemble and infer about their canonical ergodic
+properties. Moreover, we identify generic features in the ergodic properties
+depending upon the quantum phases of the initial state and the pathway of
+repeated driving that may be within the same quantum phase or across two
+different equilibrium phases.",1711.07769v3
+2018-09-24,Ionic Tuning of Cobaltites at the Nanoscale,"Control of materials through custom design of ionic distributions represents
+a powerful new approach to develop future technologies ranging from spintronic
+logic and memory devices to energy storage. Perovskites have shown particular
+promise for ionic devices due to their high ion mobility and sensitivity to
+chemical stoichiometry. In this work, we demonstrate a solid-state approach to
+control of ionic distributions in (La,Sr)CoO$_{3}$ thin films. Depositing a Gd
+capping layer on the perovskite film, oxygen is controllably extracted from the
+structure, up-to 0.5 O/u.c. throughout the entire 36 nm thickness. Commensurate
+with the oxygen extraction, the Co valence state and saturation magnetization
+show a smooth continuous variation. In contrast, magnetoresistance measurements
+show no-change in the magnetic anisotropy and a rapid increase in the
+resistivity over the same range of oxygen stoichiometry. These results suggest
+significant phase separation, with metallic ferromagnetic regions and
+oxygen-deficient, insulating, non-ferromagnetic regions, forming percolated
+networks. Indeed, X-ray diffraction identifies oxygen-vacancy ordering,
+including transformation to a brownmillerite crystal structure. The unexpected
+transformation to the brownmillerite phase at ambient temperature is further
+confirmed by high-resolution scanning transmission electron microscopy which
+shows significant structural - and correspondingly chemical - phase separation.
+This work demonstrates room-temperature ionic control of magnetism, electrical
+resistivity, and crystalline structure in a 36 nm thick film, presenting new
+opportunities for ionic devices that leverage multiple material
+functionalities.",1809.08728v1
+2018-12-13,On the 1/f spectrum in the solar wind and its connection with magnetic compressibility,"We discuss properties of Alfv\'enic fluctuations with large amplitude in
+plasmas characterised by low magnetic field compression. We note that in such
+systems power laws can not develop with arbitrarily steep slopes at large
+scales, i.e. when $|\delta \bf{B}|$ becomes of the order of the background
+field $|\bf{B}|$. In such systems there is a scale $l_0$ at which the spectrum
+has to break due to the condition of weak compressibility. A very good example
+of this dynamics is offered by solar wind fluctuations in Alfv\'enic fast
+streams, characterised by the property of constant field magnitude. We show
+here that the distribution of $\delta B=|\delta \bf{B}|$ in the fast wind
+displays a strong cut-off at $\delta B/|{\bf B}|\lesssim2$, as expected for
+fluctuations bounded on a sphere of radius $B=|{\bf B}|$. This is also
+associated with a saturation of the rms of the fluctuations at large scales and
+introduces a specific length $l_0$ above which the amplitude of the
+fluctuations becomes independent on the scale $l$. Consistent with that, the
+power spectrum at $l>l_0$ is characterised by a -1 spectral slope, as expected
+for fluctuations that are scale-independent. Moreover, we show that the
+spectral break between the 1/f and inertial range in solar wind spectra indeed
+corresponds to the scale $l_0$ at which $\left<\delta B/B\right>\sim1$. Such a
+simple model provides a possible alternative explanation of magnetic spectra
+observed in interplanetary space, also pointing out the inconsistency for a
+plasma to simultaneously maintain $|\bf{B}|\sim$const. at arbitrarily large
+scales and satisfy a Kolmogorov scaling.",1812.05716v1
+2019-06-23,A Quark-Nova in the wake of a core-collapse Supernova: a unifying model for long duration Gamma-Ray Bursts and Fast Radio Bursts,"[Abridged] By appealing to a Quark-Nova (QN; the explosive transition of a
+neutron star to a quark star) in the wake of a core-collapse Supernova
+explosion of a massive star, we develop a unified model for long duration
+Gamma-ray Bursts (LGRBs) and Fast Radio Bursts (FRBs). The time delay (years to
+decades) between the SN and the QN and, the fragmented nature (i.e. millions of
+chunks) of the relativistic QN ejecta are key to yielding a robust LGRB engine.
+In our model, a LGRB light-curve exhibits the interaction of the fragmented QN
+ejecta with a turbulent (i.e. filamentary and magnetically saturated) SN ejecta
+which is shaped by its interaction with an underlying pulsar wind nebula (PWN).
+The afterglow is due to the interaction of the QN chunks, exiting the SN
+ejecta, with the surrounding medium. Our model can fit BAT/XRT prompt and
+afterglow light-curves, simultaneously with their spectra, thus yielding the
+observed properties of LGRBs (e.g. the Band function and the X-ray flares). We
+find that the Yonetoku law and the Amati law are not fundamental but
+phenomenological. FRBs result from coherent synchrotron emission when the QN
+chunks interact with non-turbulent weakly magnetized PWN-SN ejecta, where
+conditions are prone to the Weibel instability. Magnetic field amplification
+induced by the Weibel instability sets the bunching length for electrons and
+pairs to radiate coherently. The resulting emission frequency, luminosity,
+duration and dispersion measure in our model are consistent with FRB data. We
+find a natural unification of high-energy burst phenomena from FRBs to LGRBs
+including X-ray Flashes and X-ray rich GRBs as well as Super-Luminous SNe. We
+find a possible connection between Ultra-High Energy Cosmic Rays and FRBs and
+propose that a QN following a binary neutron star merger can yield a short GRB
+(SGRB) with fits to BAT/XRT light-curves.",1906.09559v2
+2019-12-17,Nonlinear dynamics of energetic-particle driven geodesic acoustic modes in ASDEX Upgrade,"Turbulence in tokamaks generates radially sheared zonal flows. Their
+oscillatory counterparts, geodesic acoustic modes (GAMs), appear due to the
+action of the magnetic field curvature. The GAMs can be driven unstable by an
+anisotropic energetic particle (EP) population leading to the formation of
+global radial structures, called EGAMs. The EGAMs can redistribute EP energy to
+the bulk plasma through collisionless wave-particle interaction. In such a way,
+the EGAMs might contribute to the plasma heating. Thus, investigation of EGAM
+properties, especially in the velocity space, is necessary for precise
+understanding of the transport phenomena in tokamak plasmas.
+  In this work, the nonlinear dynamics of EGAMs without considering the mode
+interaction with the turbulence is investigated with the help of a
+Mode-Particle-Resonance (MPR) diagnostic implemented in the global gyrokinetic
+particle-in-cell code ORB5. An ASDEX Upgrade discharge is chosen as a reference
+case for this investigation due to its rich EP nonlinear dynamics. An
+experimentally relevant magnetic field configuration, thermal species profiles
+and an EP density profile are taken for EGAM chirping modelling and its
+comparison with available empirical data. The same magnetic configuration is
+used to explore energy transfer by the mode from the energetic particles to the
+thermal plasma including kinetic electron effects. For a given EGAM level the
+plasma heating by the mode can be significantly enhanced by varying the EP
+parameters. Electron dynamics decreases the EGAM saturation amplitude and
+consequently reduces the plasma heating, even though the mode transfers its
+energy to thermal ions much more than to electrons.",1912.07950v2
+2020-07-17,"Crystalline and magnetic structures, magnetization, heat capacity and anisotropic magnetostriction effect in a yttrium-chromium oxide","We have studied a nearly stoichiometric insulating
+Y$_{0.97(2)}$Cr$_{0.98(2)}$O$_{3.00(2)}$ single crystal by performing
+measurements of magnetization, heat capacity, and neutron diffraction. Albeit
+that the YCrO$_3$ compound behaviors like a soft ferromagnet with a coersive
+force of $\sim$ 0.05 T, there exist strong antiferromagnetic (AFM) interactions
+between Cr$^{3+}$ spins due to a strongly negative paramagnetic Curie-Weiss
+temperature, i.e., -433.2(6) K. The coexistence of ferromagnetism and
+antiferromagnetism may indicate a canted AFM structure. The AFM phase
+transition occurs at $T_\textrm{N} =$ 141.5(1) K, which increases to
+$T_\textrm{N}$(5T) = 144.5(1) K at 5 T. Within the accuracy of the present
+neuron-diffraction studies, we determine a G-type AFM structure with a
+propagation vector \textbf{k} = (1 1 0) and Cr$^{3+}$ spin directions along the
+crystallographic \emph{c} axis of the orthorhombic structure with space group
+\emph{Pnma} below $T_\textrm{N}$. At 12 K, the refined moment size is 2.45(6)
+$\mu_\textrm{B}$, $\sim$ 82\% of the theoretical saturation value 3
+$\mu_\textrm{B}$. The Cr$^{3+}$ spin interactions are probably two-dimensional
+Ising like within the reciprocal (1 1 0) scattering plane. Below
+$T_\textrm{N}$, the lattice configuration (\emph{a}, \emph{b}, \emph{c}, and
+\emph{V}) deviates largely downward from the Gr$\ddot{\textrm{u}}$neisen law,
+displaying an anisotropic magnetostriction effect and a magnetoelastic effect.
+Especially, the sample contraction upon cooling is enhanced below the AFM
+transition temperature. There is evidence to suggest that the actual
+crystalline symmetry of YCrO$_3$ compound is probably lower than the currently
+assumed one. Additionally, we compared the $t_{2\textrm{g}}$ YCrO$_3$ and the
+$e_\textrm{g}$ La$_{7/8}$Sr$_{1/8}$MnO$_3$ single crystals for a further
+understanding of the reason for the possible symmetry lowering.",2007.08985v2
+2020-10-05,Small-Scale Dynamo in Supernova-Driven Interstellar Turbulence,"Magnetic fields grow quickly even at early cosmological times, suggesting the
+action of a small-scale dynamo (SSD) in the interstellar medium of galaxies.
+Many studies have focused on idealized turbulent driving of the SSD. Here we
+simulate more realistic supernova-driven turbulence to determine whether it can
+drive an SSD. Magnetic field growth occurring in our models appears
+inconsistent with simple tangling of magnetic fields, but consistent with SSD
+action, reproducing and confirming models by Balsara et al. (2004) that did not
+include physical resistivity $\eta$. We vary $\eta$, as well as the numerical
+resolution and supernova rate, $\dot\sigma$, to delineate the regime in which
+an SSD occurs. For a given $\dot\sigma$ we find convergence for SSD growth rate
+with resolution of a parsec. For $\dot\sigma\simeq\dot\sigma_{\rm sn}$, with
+$\dot\sigma_{\rm sn}$ the solar neighbourhood rate, the critical resistivity
+below which an SSD occurs is $0.005>\eta_{\rm crit}>0.001\,\rm kpc^{-1}\,\rm km
+s^{-1}$, and this increases with the supernova rate. Across the modelled range
+of 0.5--4 pc resolution we find that for $\eta<\eta_{\rm crit}$, the SSD
+saturates at about 5% of kinetic energy equipartition, independent of growth
+rate. In the range $0.2\dot\sigma_{\rm sn}\leq \dot\sigma\leq8\dot\sigma_{\rm
+sn}$ growth rate increases with $\dot\sigma$. SSDs in the supernova-driven
+interstellar medium commonly exhibit erratic growth.",2010.01833v6
+2020-12-23,Transition to turbulence in quasi-two-dimensional MHD flow driven by lateral walls,"This manuscript has been accepted for publication in Physical Review Fluids,
+see
+https://journals.aps.org/prfluids/accepted/d5074S28J6b11905012b7cb06505e8f2149dd5f20.
+  This work investigates the mechanisms that underlie transitions to turbulence
+in a three-dimensional domain in which the variation of flow quantities in the
+out-of-plane direction is much weaker than any in-plane variation. This is
+achieved using a model for the quasi-two-dimensional magnetohydrodynamic flow
+in a duct with moving lateral walls and an orthogonal magnetic field. In this
+environment, conventional subcritical routes to turbulence, which are highly
+three-dimensional, are prohibited. To elucidate the remaining mechanisms
+involved in quasi-two-dimensional turbulent transitions, the magnetic field
+strength and degree of antisymmetry in the base flow are varied, the latter via
+the relative motion of the lateral duct walls. Introduction of any amount of
+antisymmetry to the base flow drives the critical Reynolds number infinite, as
+the TS instabilities take on opposite signs of rotation, and destructively
+interfere. However, an increasing magnetic field strength limits interaction
+between the instabilities, permitting finite critical Reynolds numbers. The
+transient growth only mildly depends on the base flow, with negligible
+differences for friction parameters $H \gtrsim 30$. Direct numerical
+simulations, initiated with random noise, indicate that for $H \leq 1$,
+supercritical exponential growth leads to saturation, but not turbulence. For
+higher $3 \leq H \leq 10$, a turbulent transition occurs, and is maintained at
+$H=10$. For $H \geq 30$, the turbulent transition still occurs, but is short
+lived, as the turbulent state quickly collapses. In addition, for $H \geq 3$,
+an inertial subrange is identified, with the perturbation energy exhibiting a
+$-5/3$ power law dependence on wave number.",2012.12497v1
+2021-02-22,Stochastic fluctuation and transport of tokamak edge plasmas with the resonant magnetic perturbation field,"We present that a statistical method known as the Complexity-Entropy analysis
+is useful to characterize a state of plasma turbulence and flux in the resonant
+magnetic perturbation (RMP) edge localized mode (ELM) control experiment. The
+RMP ELM suppression phase with the stochastic pedestal top temperature
+fluctuation can be distinguished from the natural ELM free phase with the
+chaotic fluctuation. It is discussed that the stochastic temperature
+fluctuation localized near the pedestal top can be originated from the narrow
+layer of the field penetration near the pedestal top. The forced magnetic
+island can emit the resonant drift wave of comparable sizes (relatively low-k)
+in the RMP ELM suppression phase, and it can results in the generation of
+stochastic higher wavenumber fluctuations coupled to tangled fields around the
+island. The analysis of the ion saturation current measurement around the main
+outer striking point on the divertor shows that it also becomes more stochastic
+as the stronger plasma response to the RMP field is expected.",2102.10733v7
+2021-02-24,"Gamma irradiated nanostructured NiFe2O4: Effect of gamma-photon on morphological, structural, optical and magnetic properties","The current manuscript highlights the preparation of NiFe2O4 nanoparticles by
+adopting sol-gel auto combustion route. The prime focus of this study is to
+investigate the impact of gamma irradiation on the microstructural,
+morphological, functional, optical and magnetic characteristics. The resulted
+NiFe2O4 products have been characterized employing numerous instrumental
+equipments such as FESEM, XRD, UV visible spectroscopy, FTIR and PPMS for a
+variety of gamma ray doses (0 kGy, 25 kGy and 100 kGy). FESEM micrographs
+illustrate the aggregation of ferrite nanoparticles in pristine NiFe2O4 product
+having an average particle size of 168 nm and the surface morphology is altered
+after exposure to gamma-irradiation. XRD spectra have been analyzed employing
+Rietveld method and the results of the XRD investigation reveal the desired
+phases (cubic spinel phases) of NiFe2O4 with observing other transitional
+phases. Several microstructural parameters such as bond length, bond angle,
+hopping length etc. have been determined from the analysis of Rietveld method.
+This study reports that the gamma irradiations demonstrate a great influence on
+optical bandgap energy and it varies from 1.80 and 1.89 eV evaluated via K M
+function. FTIR measurement depicts a proof for the persistence of Ni-O and Fe-O
+stretching vibrations within the respective products and thus indicating the
+successful development of NiFe2O4. The saturation magnetization (MS) of
+pristine Ni ferrite product is noticed to be 28.08 emug-1. A considerable
+increase in MS is observed in case of low gamma-dose (25 kGy) and a decrement
+nature is disclosed after the result of high dose of gamma irradiation
+(100kGy).",2102.12385v1
+2021-10-12,Small moment antiferromagnetic ordering in single crystalline La2Ni7,"Single crystals of La2Ni7 have been grown out of a binary, La-Ni melt.
+Temperature dependent, zero magnetic field, specific heat, electrical
+resistivity, and low field magnetization measurements indicate that there is a
+series of antiferromagnetic phase transitions at T1 = 61.0 \pm 0.2 K, T2 = 56.5
+\pm 0.2 K and T3 = 42.2 \pm 0.2 K. The three specific heat anomalies found at
+these temperatures qualitatively have very small entropy changes associated
+with them and the anisotropic M(H) data saturate at ~ 0.12 {\mu}B/Ni; both
+observations strongly suggesting the AFM order is associated with very small,
+itinerant, moments. Anisotropic, H||c and H{\perp}c, {\rho}(H) and M(H)
+isotherms as well as constant field, {\rho}(T) and M(T) sweeps manifest
+signatures of multiple phase lines and result in H-T phase diagrams that are
+clearly anisotropic. Analysis of M(T) and M(H) data allow for the
+identification of the two lower temperature magnetically ordered states as
+antiferromagnetically ordered, with the moments aligned along the
+crystallographic c-axis, and the higher temperature, T2 < T < T1, state as
+having a finite ferromagnetic component. In addition, the metamagnetic
+transition at low temperatures, for H applied along the crystallographic c-axis
+(H||c) appears to be a near classic example of a spin-flop transition,
+resulting in a field stabilized antiferromagnetic state with the moments
+ordered perpendicular to the c-axis. Although the small moment ordering, and
+existence of multiple phase transitions in field and temperature, suggesting an
+energetic proximity of these states, could foretell a degree of pressure
+sensitivity, our measurements of R(T) for applied pressures up to 2.0 GPa
+indicate that there is very little pressure dependence of T1, T2 and T3.",2110.06349v1
+2021-12-15,Wide ferromagnetic domain walls can host both adiabatic reflectionless spin transport and finite nonadiabatic spin torque: A time-dependent quantum transport picture,"The key concept in spintronics of current-driven noncollinear magnetic
+textures, such as magnetic domain walls (DWs), is adiabaticity, i.e., how
+closely electronic spins track classical localized magnetic moments (LMMs) of
+the texture. When mistracking occurs nonadiabatic effects arise, the salient of
+which is nonadiabatic spin transfer torque (STT) where spin angular momentum is
+exchanged between electrons and LMMs to cause their dynamics and enable DW
+motion without any current threshold. The microscopic mechanisms behind
+nonadiabatic STT have been debated theoretically for nearly two decades, but
+with unanimous conclusion that they should be significant only in narrow DWs.
+However, this contradicts sharply experiments [O. Boulle {\em et al.}, Phys.
+Rev. Lett. {\bf 101}, 216601 (2008); C. Burrowes {\em et al.}, Nat. Phys. {\bf
+6}, 17 (2010)] observing nonadiabatic STT in DWs much wider than putatively
+relevant $\sim 1$ nm scale, as well as largely insensitive to further
+increasing the DW width $w$. Here we employ time-dependent quantum transport
+for electrons to obtain both nonadiabatic and adiabatic STT from the exact
+nonequilibrium density matrix and its lowest order as adiabatic density matrix
+defined by assuming that LMMs are infinitely slow. This allows us to
+demonstrate that our microscopically, and without any simplifications of prior
+derivations like effectively static DW, extracted nonadiabatic STT: (i) does
+not decay, but instead saturates at a finite value, with increasing $w$ of a
+moving DW ensuring entry into the adiabatic limit, which we characterize by
+showing that electronic spins do not reflect from the static DW in this limit;
+and (ii) it has both out-of-DW-plane, as is the case of phenomenological
+expression widely used in the LLG equation, and in-plane components, where the
+former remains finite with increasing $w$.",2112.08356v2
+2022-04-10,Activity and Rotation of Nearby Field M Dwarfs in the TESS Southern Continuous Viewing Zone,"The evolution of magnetism in late-type dwarfs remains murky, as we can only
+weakly predict levels of activity for M dwarfs of a given mass and age. We
+report results from our spectroscopic survey of M dwarfs in the Southern
+Continuous Viewing Zone (CVZ) of the Transiting Exoplanet Survey Satellite
+(TESS). As the TESS CVZs overlap with those of the James Webb Space Telescope,
+our targets constitute a legacy sample for studies of nearby M dwarfs. For 122
+stars, we obtained at least one $R\approx 2000$ optical spectrum with which we
+measure chromospheric $\mathrm{H}\alpha$ emission, a proxy for magnetic field
+strength. The fraction of active stars is consistent with what is expected for
+field M dwarfs; as in previous studies, we find that late-type M dwarfs remain
+active for longer than their early type counterparts. While the TESS light
+curves for $\approx$20% of our targets show modulations consistent with
+rotation, TESS systematics are not well enough understood for confident
+measurements of rotation periods ($P_{\mathrm{rot}}$) longer than half the
+length of an observing sector. We report periods for 12 stars for which we
+measure $P_{\mathrm{rot}} {\lower0.8ex\hbox{$\buildrel <\over\sim$}}$ 15 d or
+find confirmation for the TESS-derived $P_{\mathrm{rot}}$ in the literature.
+Our sample of 21 $P_{\mathrm{rot}}$, which includes periods from the
+literature, is consistent with our targets being spun-down field stars.
+Finally, we examine the $\mathrm{H}\alpha$-to-bolometric luminosity
+distribution for our sample. Two stars are rotating fast enough to be
+magnetically saturated, but are not, hinting at the possibility that fast
+rotators may appear inactive in $\mathrm{H}\alpha$.",2204.04700v1
+2022-05-13,The Factory and the Beehive. IV. A Comprehensive Study of the Rotation X-ray Activity Relation in Praesepe and the Hyades,"X-ray observations of low-mass stars in open clusters are critical to
+understanding the dependence of magnetic activity on stellar properties and
+their evolution. Praesepe and the Hyades, two of the nearest, most-studied open
+clusters, are among the best available laboratories for examining the
+dependence of magnetic activity on rotation for stars with masses lower than
+$\approx 1\ M_{\odot}$. We present an updated study of the rotation X-ray
+activity relation in the two clusters. We updated membership catalogs that
+combine pre-Gaia catalogs with new catalogs based on Gaia Data Release 2. The
+resulting catalogs are the most inclusive ones for both clusters: 1739 Praesepe
+and 1315 Hyades stars. We collected X-ray detections for cluster members, for
+which we analyzed, re-analyzed, or collated data from ROSAT, the Chandra X-ray
+Observatory, the Neil Gehrels Swift Observatory, and XMM-Newton. We have
+detections for 326 Praesepe and 462 Hyades members, of which 273 and 164,
+respectively, have rotation periods, an increase of 6$\times$ relative to what
+was previously available. We find that at $\approx$700 Myr, only M dwarfs
+remain saturated in X-rays, with only tentative evidence for supersaturation.
+We also find a tight relation between the Rossby number and fractional X-ray
+luminosity $L_\mathrm{X}/L_\mathrm{bol}$ in unsaturated single members,
+suggesting a power-law index between $-3.2$ and $-3.9$. Lastly, we find no
+difference in the coronal parameters between binary and single members. These
+results provide essential insight into the relative efficiency of magnetic
+heating of the stars' atmospheres, thereby informing the development of robust
+age-rotation-activity relations.",2205.06461v1
+2023-01-11,Coupling multi-fluid dynamics equipped with Landau closures to the particle-in-cell method,"The particle-in-cell (PIC) method is successfully used to study magnetized
+plasmas. However, this requires large computational costs and limits
+simulations to short physical run-times and often to setups in less than three
+spatial dimensions. Traditionally, this is circumvented either via hybrid-PIC
+methods (adopting massless electrons) or via magneto-hydrodynamic-PIC methods
+(modelling the background plasma as a single charge-neutral
+magneto-hydrodynamical fluid). Because both methods preclude modelling
+important plasma-kinetic effects, we introduce a new fluid-PIC code that
+couples a fully explicit and charge-conservative multi-fluid solver to the PIC
+code SHARP through a current-coupling scheme and solve the full set of
+Maxwell's equations. This avoids simplifications typically adopted for Ohm's
+Law and enables us to fully resolve the electron temporal and spatial scales
+while retaining the versatility of initializing any number of ion, electron, or
+neutral species with arbitrary velocity distributions. The fluid solver
+includes closures emulating Landau damping so that we can account for this
+important kinetic process in our fluid species. Our fluid-PIC code is
+second-order accurate in space and time. The code is successfully validated
+against several test problems, including the stability and accuracy of shocks
+and the dispersion relation and damping rates of waves in unmagnetized and
+magnetized plasmas. It also matches growth rates and saturation levels of the
+gyro-scale and intermediate-scale instabilities driven by drifting charged
+particles in magnetized thermal background plasmas in comparison to linear
+theory and PIC simulations. This new fluid-SHARP code is specially designed for
+studying high-energy cosmic rays interacting with thermal plasmas over
+macroscopic timescales.",2301.04679v2
+2023-03-04,Nonlinear microtearing modes in MAST and their stochastic layer formation,"First nonlinear gyrokinetic simulations of microtearing modes in the core of
+a MAST case are performed on two surfaces of the high-collisionality discharge
+used in Valovi\v{c} et al. Nucl. Fusion 51.7 (2011) to obtain the favorable
+energy confinement scaling with collisionality, $\tau_E\propto\,\nu_*^{-1}$. On
+the considered surfaces microtearing modes dominate linearly at binormal length
+scales of the order of the ion Larmor radius. While the effect of electron
+collision frequency is moderate in linear simulations, a strong dependence on
+this parameter is found in nonlinear simulations at $r/a=0.5$, where $r$ and
+$a$ are the surface and tokamak minor radius, respectively. The dynamics of
+magnetic islands generated by microtearing modes is analysed, showing that the
+radial extent of the stochastic region caused by islands overlapping plays an
+important role in determining the saturation level of the microtearing mode
+driven heat flux. Local nonlinear gyrokinetic simulations show that the
+microtearing mode driven heat flux, $Q_e^\mathrm{MTM}$, is largely dominated by
+magnetic flutter and depends strongly on the magnetic shear, $\hat{s}$.
+Comparing two surfaces, $r/a=0.5$ and $r/a=0.6$, reveals that
+$Q_e^\mathrm{MTM}$ is negligible at $r/a=0.5$ ($\hat{s}=0.34$), with the
+electron temperature gradient driven heat flux, $Q_e^\mathrm{ETG}$, comparable
+to the experimental electron heat flux, $Q_e^\mathrm{exp}$, while
+$Q_e^\mathrm{MTM}$ is significantly larger and comparable to $Q_e^\mathrm{ETG}$
+and $Q_e^\mathrm{exp}$ at $r/a=0.6$ ($\hat{s}=1.1$). Microtearing modes cause
+more experimentally significant transport in higher $\hat{s}$ regions and may
+influence (together with electron temperature gradient modes) the observed
+scaling of energy confinement time with collisionality (Valovi\v{c} et al.
+Nucl. Fusion 51.7 (2011)).",2303.02379v3
+2023-03-15,High spin-polarization in a disordered novel quaternary Heusler alloy FeMnVGa,"In this work, we report the successful synthesis of a Fe-based novel
+half-metallic quaternary Heusler alloy FeMnVGa and its structural, magnetic and
+transport properties probed through different experimental methods and
+theoretical technique. Density functional theory (DFT) calculations performed
+on different types of structure reveal that Type-2 ordered structure (space
+group: F-43m, Ga at 4a, V at 4b, Mn at 4c and Fe at 4d) possess minimum energy
+among all the ordered variants. Ab-initio simulations in Type 2 ordered
+structure further reveal that the compound is half-metallic ferromagnet (HMF)
+having a large spin-polarization (89.9 %). Neutron diffraction reveal that the
+compound crystalizes in disordered Type-2 structure (space group: Fm-3m) in
+which Ga occupy at 4a, V at 4b and Fe/Mn occupy 4c/4d sites with 50:50
+proportions. The structural disorder is further confirmed by X-ray diffraction
+(XRD), extended X-ray absorption fine structure (EXAFS),57Fe Mossbauer
+spectrometry results and DFT calculations. Magnetisation studies suggest that
+the compound orders ferromagnetically below TC ~ 293 K and the saturation
+magnetization follows Slater-Pauling rule. Mossbauer spectrometry, along with
+neutron diffraction suggest that Mn is the major contributor to the total
+magnetism in the compound consistent with the theoretical calculations. First
+principle calculations indicate that spin-polarization remain high (81.3 %)
+even in the presence of such large atomic disorder. The robustness of the HMF
+property in presence of disorder is a quite unique characteristic over other
+reported HMF in literature and make this compound quiet promising for
+spintronics applications.",2303.08579v1
+2023-06-28,Degenerate and non-degenerate parametric excitation in YIG nanostructures,"We study experimentally the processes of parametric excitation in microscopic
+magnetically saturated disks of nanometer-thick Yttrium Iron Garnet. We show
+that, depending on the relative orientation between the parametric pumping
+field and the static magnetization, excitation of either degenerate or
+non-degenerate magnon pairs is possible. In the latter case, which is
+particularly important for applications associated with the realization of
+computation in the reciprocal space, a single-frequency pumping can generate
+pairs of magnons whose frequencies correspond to different eigenmodes of the
+disk. We show that, depending on the size of the disk and the modes involved,
+the frequency difference in a pair can vary in the range 0.1-0.8 GHz. We
+demonstrate that in this system, one can easily realize a practically important
+situation where several magnon pairs share the same mode. We also observe the
+simultaneous generation of up to six different modes using a fixed-frequency
+monochromatic pumping. Our experimental findings are supported by numerical
+calculations that allow us to unambiguously identify the excited modes. Our
+results open new possibilities for the implementation of reciprocal-space
+computing making use of low damping magnetic insulators.",2306.16094v1
+2023-08-18,"Magnon Diffusion Length and Longitudinal Spin Seebeck Effect in Vanadium Tetracyanoethylene (V[TCNE]$_x$, $x \sim 2$)","Spintronic, spin caloritronic, and magnonic phenomena arise from complex
+interactions between charge, spin, and structural degrees of freedom that are
+challenging to model and even more difficult to predict. This situation is
+compounded by the relative scarcity of magnetically-ordered materials with
+relevant functionality, leaving the field strongly constrained to work with a
+handful of well-studied systems that do not encompass the full phase space of
+phenomenology predicted by fundamental theory. Here we present an important
+advance in this coupled theory-experiment challenge, wherein we extend existing
+theories of the spin Seebeck effect (SSE) to explicitly include the
+temperature-dependence of magnon non-conserving processes. This expanded theory
+quantitatively describes the low-temperature behavior of SSE signals previously
+measured in the mainstay material yttrium iron garnet (YIG) and predicts a new
+regime for magnonic and spintronic materials that have low saturation
+magnetization, $M_S$, and ultra-low damping. Finally, we validate this
+prediction by directly observing the spin Seebeck resistance (SSR) in the
+molecule-based ferrimagnetic semiconductor vanadium tetracyanoethylene
+(V[TCNE]$_x$, $x \sim 2$). These results validate the expanded theory, yielding
+SSR signals comparable in magnitude to YIG and extracted magnon diffusion
+length ($\lambda_m>1$ $\mu$ m) and magnon lifetime for V[TCNE]$_x$
+($\tau_{th}\approx 1-10$ $\mu$ s) exceeding YIG ($\tau_{th}\sim 10$ ns).
+Surprisingly, these properties persist to room temperature despite relatively
+low spin wave stiffness (exchange). This identification of a new regime for
+highly efficient SSE-active materials opens the door to a new class of magnetic
+materials for spintronic and magnonic applications.",2308.09752v1
+2023-12-26,Observation of a 1/3 Magnetisation Plateau Phase as Evidence for the Kitaev Interaction in a Honeycomb-Lattice Antiferromagnet,"Fractional magnetisation plateaus, in which the magnetisation is pinned at a
+fraction of its saturated value within a range of external magnetic field, are
+spectacular macroscopic manifestations of the collective quantum behaviours.
+One prominent example of the plateau phase is found in spin-1/2
+triangular-lattice antiferromagnets featuring strong geometrical frustration,
+and is often interpreted as quantum-fluctuation-stabilised state in magnetic
+field via the ""order-by-disorder"" mechanism. Here, we observe an unprecedented
+1/3 magnetisation plateau between 5.2 and 7.4 T at 2 K in a spin-1
+antiferromagnet Na$_3$Ni$_2$BiO$_6$ with a honeycomb lattice, where
+conventionally no geometrical frustration is anticipated. By carrying out
+elastic neutron scattering measurements, we propose the spin structure of the
+plateau phase to be an unusual partial spin-flop ferrimagnetic order,
+transitioning from the zigzag antiferromagnetic order in zero field. Our
+theoretical calculations show that the plateau phase is stabilised by the
+bond-anisotropic Kitaev interaction. These results provide a new paradigm for
+the exploration of rich quantum phases in frustrated magnets and exotic Kitaev
+physics in high-spin systems.",2312.15932v1
+2006-12-18,Amplitude Saturation in Beta Cephei Models - Preliminary Results,"Using nonlinear hydrocodes we have calculated single mode saturation
+amplitudes for beta Cephei models. Predicted saturation amplitudes are
+systematically higher than amplitudes observed in beta Cephei variables, even
+in monoperiodic ones. We argue that collective saturation of the pulsation
+instability by a dozen or so acoustic modes brings the theoretical amplitudes
+to the observed level.",0612489v1
+1997-06-10,Analysis of the Interplay of Quantum Phases and Nonlinearity Applied to Dimers with Anharmonic Interactions,"We extend our analysis of the effects of the interplay of quantum phases and
+nonlinearity to address saturation effects in small quantum systems.
+  We find that initial phases dramatically control the dependence of
+self-trapping on initial asymmetry of quasiparticle population and can compete
+or act with nonlinearity as well as saturation effects. We find that there is a
+minimum finite saturation value in order to obtain self-trapping that crucially
+depends on the initial quasiparticle phases and present a detailed
+phase-diagram in terms of the control parameters of the system: nonlinearity
+and saturation.",9706093v1
+2002-10-24,Violation of Ioffe-Regel condition but saturation of resistivity of the high Tc cuprates,"We demonstrate that the resistivity data of a number of high Tc cuprates, in
+particular La(2-x)SrxCuO4, are consistent with resistivity saturation, although
+the Ioffe-Regel condition is strongly violated. By using the f-sum rule
+together with calculations of the kinetic energy in the t-J model, we show that
+the saturation resistivity is unusually large. This is related to the strong
+reduction of the kinetic energy due to strong correlation effects. The
+fulfilment of the Ioffe-Regel condition for conventional transition metal
+compounds is found to be somewhat accidental.",0210543v1
+2003-08-01,A density functional theory study of electric potential saturation: planar geometry,"We investigate the possibility of electrostatic potential saturation, which
+may lead to the phenomenon of effective charge saturation. The system under
+study is a uniformly charged infinite plane immersed in an arbitrary
+electrolyte made up of several micro-species. To describe the electric double
+layer, we use a generic density functional theory in which the local
+micro-ionic density profiles are arbitrary functions of the local electrostatic
+potential. A necessary and sufficient condition is obtained for saturation,
+whereby the electrostatic potential created by the plane becomes independent of
+its bare charge, provided the latter is large enough.",0308015v1
+2005-10-07,Electric Field-Dependent Charge-Carrier Velocity in Semiconducting Carbon Nanotubes,"Charge transport in semiconducting single-walled nanotubes (SWNTs) with
+Schottky-barrier contacts has been studied at high bias. We observe nearly
+symmetric ambipolar transport with electron and hole currents significantly
+exceeding 25 micron-ampere, the reported current limit in metallic SWNTs due to
+optical phonon emission. Four simple models for the field-dependent velocity
+(ballistic, current saturation, velocity saturation, and constant mobility) are
+studied in the unipolar regime; the high-bias behavior is best explained by a
+velocity saturation model with a saturation velocity of 2 x 10^7 cm/s.",0510158v1
+1999-11-09,"Small-x Physics, High Parton Densities and Parton Saturation in QCD","Partons are defined as the quanta in a Fock space description of a hadron.
+Gluon saturation is described in the Weizs\""{a}cker-Williams approximation for
+a large nucleus. The elements of DGLAP and BFKL evolution are given with the
+BFKL equation derived in a large-$N_c$ dipole formalism. A more general
+discussion of saturation is given in terms of a dipole scattering on a nucleon
+or nucleus. Possible evidence for saturation at HERA is discussed.",9911289v1
+2001-12-10,Nonlinear QCD Evolution: Saturation without Unitarization,"We consider the perturbative description of saturation based on the nonlinear
+QCD evolution equation of Balitsky and Kovchegov (BK). Although the nonlinear
+corrections lead to saturation of the scattering amplitude locally in impact
+parameter space, we show that they do not unitarize the total cross section.
+The total cross section for the scattering of a strongly interacting probe on a
+hadronic target is found to grow exponentially with rapidity. The origin of
+this violation of unitarity is the presence of long range Coulomb fields away
+from the saturation region. The growth of these fields with rapidity is not
+tempered by the nonlinearity of the BK equation.",0112140v1
+2002-09-11,The Energy Dependence of the Saturation Momentum from RG Improved BFKL Evolution,"We study the energy dependence of the saturation momentum in the context of
+the collinearly improved Leading and Next to Leading BFKL evolution, and in the
+presence of saturation boundaries. We find that the logarithmic derivative of
+the saturation momentum is varying very slowly with Bjorken-x, and its value is
+in agreement with the Golec-Biernat and Wusthoff model in the relevant x
+region. The scaling form of the amplitude for dipole-dipole or dipole-hadron
+scattering in the perturbative side of the boundary is given.",0209121v1
+2003-11-07,Energy dependence of Cronin momentum in saturation model for $p+A$ and $A+A$ collisions,"We calculate $\sqrt{s}$ dependence of Cronin momentum for $p+A$ and $A+A$
+collisions in saturation model. We show that this dependence is consistent with
+expectation from formula which was obtained using simple dimentional
+consideration. This can be used to test validity of saturation model (and
+distinguish among its variants) and measure $x$ dependence of saturation
+momentum from experimental data.",0311099v1
+2003-11-14,Introduction to Low x Physics and Saturation,"The idea of saturation of parton densities in small x physics is briefly
+introduced. Some aspects of saturation are described, mainly focusing on the
+status of our knowledge on the non-linear equations describing the high parton
+density regime. Implications of saturation ideas on the description of nuclear
+collisions at the Relativistic Heavy Ion Collider are discussed.",0311182v1
+2004-07-01,Saturation and forward jets at HERA,"We analyse forward-jet production at HERA in the framework of the
+Golec-Biernat and Wusthoff saturation models. We obtain a good description of
+the forward jet cross sections measured by the H1 and ZEUS collaborations in
+the two-hard-scale region kT ~ Q >> Lambda_QCD with two different
+parametrisations with either significant or weak saturation effects. The weak
+saturation parametrization gives a scale compatible with the one found for the
+proton structure function F_2. We argue that Mueller-Navelet jets at the
+Tevatron and the LHC could help distinguishing between both options.",0407011v2
+2004-07-13,Instanton-driven Gluon Saturation,"We report on the interesting possibility of instanton-driven gluon saturation
+in lepton-nucleon scattering at small Bjorken-x. The explicitly known instanton
+gauge field serves as a concrete realization of an underlying non-perturbative
+saturation mechanism associated with strong classical fields. The conspicuous,
+intrinsic instanton size scale known from lattice simulations, turns out to
+determine the saturation scale. The ``colour glass condensate'' can be
+identified in our approach with the QCD-sphaleron state, dominating
+instanton-induced processes in the softer regime.",0407146v1
+2006-10-18,Saturation effects in diffractive scattering at LHC energies,"Unitarization schemes can be reduced to non-linear equations which saturate
+at small $b$ the evolution of the elastic amplitude with $s$, and which mimic
+parton saturation in the non-perturbative regime. These equations enable us to
+study the effect of saturation on total and elastic cross sections for various
+models, and to evaluate the uncertainties on $\sigma_{tot}$ and $\rho(s,t)$ at
+the LHC in the presence of a hard pomeron.",0610222v2
+2003-03-28,Lattice packings with gap defects are not completely saturated,"We show that a honeycomb circle packing in $\R^2$ with a linear gap defect
+cannot be completely saturated, no matter how narrow the gap is. The result is
+motivated by an open problem of G. Fejes T\'oth, G. Kuperberg, and W.
+Kuperberg, which asks whether of a honeycomb circle packing with a linear shift
+defect is completely saturated. We also show that an fcc sphere packing in
+$\R^3$ with a planar gap defect is also not completely saturated.",0303366v1
+2005-01-28,Discrete soliton collisions in a waveguide array with saturable nonlinearity,"We study the symmetric collisions of two mobile breathers/solitons in a model
+for coupled wave guides with a saturable nonlinearity. The saturability allows
+the existence of breathers with high power. Three main regimes are observed:
+breather fusion, breather reflection and breather creation. The last regime
+seems to be exclusive of systems with a saturable nonlinearity, and has been
+previously observed in continuous models. In some cases a ``symmetry breaking''
+can be observed, which we show to be an numerical artifact.",0501050v2
+2002-11-22,Saturation in heteronuclear photoassociation of 6Li7Li,"We report heteronuclear photoassociation spectroscopy in a mixture of
+magneto-optically trapped 6Li and 7Li. Hyperfine resolved spectra of the
+vibrational level v=83 of the singlet state have been taken up to intensities
+of 1000 W/cm^2. Saturation of the photoassociation rate has been observed for
+two hyperfine transitions, which can be shown to be due to saturation of the
+rate coefficient near the unitarity limit. Saturation intensities on the order
+of 40 W/cm^2 can be determined.",0211098v1
+2007-06-18,A unified description of diffractive deep inelastic scattering with saturation,"We propose a new description of inclusive diffraction in deep inelastic
+scattering (DIS). The diffractive structure functions are expressed in the
+dipole picture and contain heavy-quark contributions. The dipole scattering
+amplitude, a saturation model fitted on inclusive DIS data, features a
+saturation scale Q_s(x) larger than 1 GeV for x=10^{-5}. The q\bar{q}g
+contribution to the diffractive final state is modeled in such a way that both
+the large-Q^2 and small-beta limits are implemented. In the regime xpom<0.01 in
+which saturation is expected to be relevant, we obtain a parameter-free
+description of the HERA data with chi^2/points=1.2.",0706.2682v1
+2008-05-14,On unconditionally saturated Banach spaces,"We prove a structural property of the class of unconditionally saturated
+separable Banach spaces. We show, in particular, that for every analytic set
+$\aaa$, in the Effros-Borel space of subspaces of $C[0,1]$, of unconditionally
+saturated separable Banach spaces, there exists an unconditionally saturated
+Banach space $Y$, with a Schauder basis, that contains isomorphic copies of
+every space $X$ in the class $\aaa$.",0805.2046v1
+2009-04-17,Nuclear Saturation with Low Momentum Interactions,"Relativistic effects are investigated in nuclear matter calculations
+employing renormalized low-momentum nucleon-nucleon ($NN$) interactions. It is
+demonstrated that the relativistic effects cure a problem of non-relativistic
+low-momentum interactions, which fail to reproduce saturation of nuclear
+matter. Including relativistic effects, one already obtains saturation in a
+Hartree-Fock calculation. Brueckner-Hartree-Fock calculations lead to a further
+improvement of the saturation properties. The results are rather insensitive to
+the realistic $NN$ interaction on which they are based.",0904.2663v1
+2010-07-15,The effect of gain saturation in a gain compensated perfect lens,"The transmission of evanescent waves in a gain-compensated perfect lens is
+discussed. In particular, the impact of gain saturation is included in the
+analysis, and a method for calculating the fields of such nonlinear systems is
+developed. Gain compensation clearly improves the resolution; however, a number
+of nonideal effects arise as a result of gain saturation. The resolution
+associated with the lens is strongly dependent on the saturation constant of
+the active medium.",1007.2486v1
+2010-10-12,Saturation of interband absorption in graphene,"The transient response of an intrinsic graphene, which is caused by the
+ultrafast interband transitions, is studied theoretically for the range of
+pumping correspondent to the saturated absorption regime. Spectral and temporal
+dependencies of the photoexcited concentration as well as the transmission and
+relitive absotption coefficients are considered for mid-IR and visible (or
+near-IR) spectral regions at different durations of pulse and broadening
+energies. The characteristic intencities of saturation are calculated and the
+results are compared with the experimental data measured for the near-IR lasers
+with a saturable absorber. The negative absorption of a probe radiation during
+cascade emission of optical phonons is obtained.",1010.2392v1
+2010-12-31,The Status of Parton Saturation and the CGC,"This is a personal summary of the meeting ""Saturation, the Color Glass
+Condensate and Glasma: What Have we Learned from RHIC?"" that took place at BNL
+in May 2010. The purpose of the meeting was to discuss the status of high
+density QCD and parton saturation, and to review the progress that RHIC has
+allowed in the field.",1101.0260v1
+2011-05-23,Saturating Sperner families,"A family $\cF \subseteq 2^{[n]}$ saturates the monotone decreasing property
+$\cP$ if $\cF$ satisfies $\cP$ and one cannot add any set to $\cF$ such that
+property $\cP$ is still satisfied by the resulting family. We address the
+problem of finding the minimum size of a family saturating the $k$-Sperner
+property and the minimum size of a family that saturates the Sperner property
+and that consists only of $l$-sets and $(l+1)$-sets.",1105.4453v1
+2011-12-09,Saturated Domino Coverings,"A domino covering of a board is saturated if no domino is redundant. We
+introduce the concept of a fragment tiling and show that a minimal fragment
+tiling always corresponds to a maximal saturated domino covering. The size of a
+minimal fragment tiling is the domination number of the board. We define a
+class of regular boards and show that for these boards the domination number
+gives the size of a minimal X-pentomino covering. Natural sequences that count
+maximal saturated domino coverings of square and rectangular boards are
+obtained. These include the new sequences A193764, A193765, A193766, A193767,
+and A193768 of OEIS.",1112.2115v1
+2012-02-10,Gluon saturation and pseudo-rapidity distributions of charged hadrons at RHIC energy regions,"We modified the gluon saturation model by rescaling the momentum fraction
+according to saturation momentum and introduced the Cooper-Frye hydrodynamic
+evolution to systematically study the pseudo-rapidity distributions of final
+charged hadrons at different energies and different centralities for Au-Au
+collisions in relativistic heavy-ion collisions at BNL Relativistic Heavy Ion
+Collider (RHIC). The features of both gluon saturation and hydrodynamic
+evolution at different energies and different centralities for Au-Au collisions
+are investigated in this paper.",1202.2174v3
+2012-03-06,Uniquely K_r-Saturated Graphs,"A graph G is uniquely K_r-saturated if it contains no clique with r vertices
+and if for all edges e in the complement, G + e has a unique clique with r
+vertices. Previously, few examples of uniquely K_r-saturated graphs were known,
+and little was known about their properties. We search for these graphs by
+adapting orbital branching, a technique originally developed for symmetric
+integer linear programs. We find several new uniquely K_r-saturated graphs with
+4 \leq r \leq 7, as well as two new infinite families based on Cayley graphs
+for Z_n with a small number of generators.",1203.1084v1
+2012-03-30,Enumeration of saturated chains in Dyck lattices,"We determine a general formula to compute the number of saturated chains in
+Dyck lattices, and we apply it to find the number of saturated chains of length
+2 and 3. We also compute what we call the Hasse index (of order 2 and 3) of
+Dyck lattices, which is the ratio between the total number of saturated chains
+(of length 2 and 3) and the cardinality of the underlying poset.",1203.6807v1
+2013-04-30,A Characterization of Saturated Designs for Factorial Experiments,"In this paper we study saturated fractions of factorial designs under the
+perspective of Algebraic Statistics. We define a criterion to check whether a
+fraction is saturated or not with respect to a given model. The proposed
+criterion is based purely on combinatorial objects. Our technique is
+particularly useful when several fractions are needed. We also show how to
+generate random saturated fractions with given projections, by applying the
+theory of Markov bases for contingency tables.",1304.7914v1
+2013-05-01,Unitarity Saturation In P-P Scattering,"The properties of soft p-p scattering amplitudes at the TeV-scale are studied
+so as to identify the impact of s and t channel unitarity screenings on their
+behavior at exceedingly high energies and determine the rate at which they
+approach the bounds implied by unitarity saturation. I shall examine the
+relevant high energy soft cross section features, as well as, the corresponding
+behavior of the coupled phenomenological models aiming to reproduce this
+data.\\ My conclusion is that p-p black body saturation is not attained up to
+100 TeV. More over, I do not expect that saturation will be attained at
+energies that can be investigated experimentally.",1305.0299v1
+2013-07-28,Saturable absorption in multi-core fiber couplers,"The saturable absorption characteristics of two-, three-, and five-core
+one-dimensional fiber coupler arrays and the seven-core hexagonal fiber coupler
+array are investigated. It is shown that the performance of all these saturable
+absorbers are comparable and not much is gained, if anything, by going from a
+two-core nonlinear coupler geometry to a higher number of cores. This
+observation is supported by the similarity of the saturable absorption curves,
+as well as comparable pulse characteristics obtained from the simulation of a
+generic mode-locked fiber laser cavity.",1307.7338v1
+2014-05-14,Saturation of the morphisms in the database category,"In this paper we present the problem of saturation of a given morphism in the
+database category DB, which is the base category for the functiorial semantics
+of the database schema mapping systems used in Data Integration theory. This
+phenomena appears in the case when we are using the Second-Order
+tuple-generating dependencies (SOtgd) with existentially quantified
+non-built-in functions, for the database schema mappings. We provide the
+algorithm of the saturation for a given morphism, which represents a mapping
+between two relational databases, and show that the original morphism in DB can
+be equivalently substituted by its more powerful saturated version in any
+commutative diagram in DB.",1405.3955v1
+2015-03-09,Combinatorial characterizations of the saturation and the associated primes of the fourth power of edge ideals,"To compute the local cohomology of powers of edge ideals one needs to know
+their saturations. The saturation of the second and third powers has been
+described in terms of the graph in [13] and [10]. In this article, we give a
+combinatorial description of the generators of the saturation of the fourth
+power. As a consequence, we are able to give a complete classification of the
+associated primes of the fourth power of edge ideals in terms of the graph.",1503.02396v1
+2015-10-19,Random Nonlinear Infinite-Level-System Model for Amorphous Solid Phonon Echo and Saturation Phenomena,"The first two successful predictions for amorphous solid experiments by
+tunneling-two-level-system (TTLS) was phonon echo and saturation phenomena. In
+this paper by generalizing TTLS to infinite-level-system model with certain
+randomness and nonlinearity, we prove that phonon echo is a stimulated emission
+process. The classical infinite-level-system (taking $\hbar\to 0$ limit) cannot
+find saturation effect, while quantum infinite-level-system can find it with
+certain nonlinearity assumed. We also prove that without randomness or
+nonlinearity neither phonon echo nor saturation exists in arbitrary
+infinite-level-system.",1510.05538v2
+2015-10-28,Saturation and geometrical scaling -- from small $x$ deep inelastic ep scattering to high energy proton-proton and heavy ion collisions,"Gluon distributions of colliding hadrons saturate as a result of the
+non-linear evolution equations of QCD. As a consequence there exists the so
+called saturation momentum, which is related to the gluon density per unit
+rapidity per transverse area. When saturation momentum is the only scale for
+physical processes, different observables exhibit geometrical scaling (GS). We
+show a number of examples of GS and its violation in different reactions.",1510.08475v2
+2015-11-02,Saturation Physics on the Energy Frontier,"Saturation physics is expected to be relevant at sufficiently small parton
+momentum fractions $x$ in high-energy proton- (or deuteron-)ion collisions at
+RHIC and the LHC. Accordingly, these collisions provide the best available
+testing ground for the saturation model. However, producing precise numerical
+predictions from the model is a complicated task; the state of the art in this
+area involves next-to-leading order QCD calculations, which are difficult to do
+numerically. Here I'll review recent progress in extracting numerical
+predictions from saturation models and matching them to experimental results.",1511.00386v1
+2015-12-21,Dynamics of viscous coalescing droplets in a saturated vapor phase,"The dynamics of two liquid droplets coalescing in their saturated vapor phase
+are investigated by Lattice Boltzmann numerical simulations. Attention is paid
+to the effect of the vapor phase on the formation and growth dynamics of the
+liquid bridge in the viscous regime. We observe that the onset of the
+coalescence occurs earlier and the expansion of the bridge initially proceeds
+faster when the coalescence takes place in a saturated vapor compared to the
+coalescence in a non-condensable gas. We argue that the initially faster
+evolution of the coalescence in the saturated vapor is caused by the vapor
+transport through condensation during the early stages of the coalescence.",1512.06814v1
+2016-12-20,Imbibition triggered by capillary condensation in nanopores,"We study the spatio-temporal dynamics of water uptake by capillary
+condensation from unsaturated vapor in mesoporous silicon layers (pore radius
+$r_\mathrm{p} \simeq 2$ nm), taking advantage of the local changes in optical
+reflectance as a function of water saturation. Our experiments elucidate two
+qualitatively different regimes as a function of the imposed external vapor
+pressure: for low saturations, equilibration occurs via a diffusion-like
+process; for high saturations, an imbibition-like wetting front results in fast
+equilibration towards a fully saturated sample. We show that the imbibition
+dynamics can be described by a modified Lucas-Washburn equation that takes into
+account the liquid stresses implied by Kelvin equation.",1612.06684v1
+2017-10-10,Saturation of Berge Hypergraphs,"Given a graph $F$, a hypergraph is a Berge-$F$ if it can be obtained by
+expanding each edge in $F$ to a hyperedge containing it. A hypergraph $H$ is
+Berge-$F$-saturated if $H$ does not contain a subgraph that is a Berge-$F$, but
+for any edge $e\in E(\overline{H})$, $H+e$ does. The $k$-uniform saturation
+number of Berge-$F$ is the minimum number of edges in a $k$-uniform
+Berge-$F$-saturated hypergraph on $n$ vertices. For $k=2$ this definition
+coincides with the classical definition of saturation for graphs. In this paper
+we study the saturation numbers for Berge triangles, paths, cycles, stars and
+matchings in $k$-uniform hypergraphs.",1710.03735v1
+2017-11-14,On ISS-Lyapunov functions for infinite-dimensional linear control systems subject to saturations,"- This article deals with the derivation of ISS-Lyapunov functions for
+infinite-dimensional linear systems subject to saturations. Two cases are
+considered: 1) the saturation acts in the same space as the control space; 2)
+the saturation acts in another space, especially a Banach space. For the first
+case, an explicit ISS-Lyapunov function can be derived. For the second case, we
+can only ensure the existence of an ISS-Lyapunov function.",1711.05024v1
+2017-12-09,On the saturation number of graphs,"Let $G=(V,E)$ be a simple connected graph. A matching $M$ in a graph $G$ is a
+collection of edges of $G$ such that no two edges from $M$ share a vertex. A
+matching $M$ is maximal if it cannot be extended to a larger matching in $G$.
+The cardinality of any smallest maximal matching in $G$ is the saturation
+number of $G$ and is denoted by $s(G)$. In this paper we study the saturation
+number of the corona product of two specific graphs. We also consider some
+graphs with certain constructions that are of importance in chemistry and study
+their saturation number.",1712.03422v1
+2018-01-03,Saturation of the hosing instability in quasi-linear plasma accelerators,"The beam hosing instability is analyzed theoretically for a witness beam in
+the quasi-linear regime of plasma accelerators. In this regime, the hosing
+instability saturates, even for a monoenergetic bunch, at a level much less
+than standard scalings predict. Analytic expressions are derived for the
+saturation distance and amplitude and are in agreement with numerical results.
+Saturation is due to the natural head-to-tail variations in the focusing force,
+including the self-consistent transverse beam loading.",1801.01104v1
+2018-02-27,Nonlinear absorption study in four and five energy level systems,"Nonlinear absorption in four and five energy level systems have been studied
+with the aid of steady-state rate equation approach. We report on the
+tunability of saturable and reverse saturable absorption as a function of
+spectroscopic parameters (lifetimes and absorption cross-sections). Detailed
+information is given on the estimation of spectroscopic parameters in the
+nonlinear absorption spectroscopy. The exhaustive graphical analysis of this
+article can provide the brief idea about transmittance curves of the nonlinear
+absorption to the experimentalists. In four and five level cascade models,
+simultaneously saturable and reverse saturable absorption can be generated.",1802.09907v1
+2019-07-19,Spectral Analysis of Latent Representations,"We propose a metric, Layer Saturation, defined as the proportion of the
+number of eigenvalues needed to explain 99% of the variance of the latent
+representations, for analyzing the learned representations of neural network
+layers. Saturation is based on spectral analysis and can be computed
+efficiently, making live analysis of the representations practical during
+training. We provide an outlook for future applications of this metric by
+outlining the behaviour of layer saturation in different neural architectures
+and problems. We further show that saturation is related to the generalization
+and predictive performance of neural networks.",1907.08589v1
+2019-11-02,"On The Study Of D-Optimal Saturated Designs For Mean, Main Effects and $F_1$-Two-Factor Interactions For $2^k$-Factorial Experiments","The goal of this paper is to develop methods for the construction of
+saturated designs that include the mean, main effects and the two-factor
+interactions of one factor with a subset of the remaining factors. If one
+factor is interacting with all the remaining factors give a method for the
+construction of a d-optimal saturated design. If one factor is interacting with
+a proper subset of the remaining factor we discuss the saturated d-optimal
+design for specific cases.",1911.00794v1
+2020-12-29,Matrix patterns with bounded saturation function,"A 0-1 matrix $M$ contains a 0-1 matrix pattern $P$ if we can obtain $P$ from
+$M$ by deleting rows and/or columns and turning arbitrary 1-entries into 0s.
+The saturation function $\mathrm{sat}(P,n)$ for a 0-1 matrix pattern $P$
+indicates the minimum number of 1s in a $n \times n$ 0-1 matrix that does not
+contain $P$, but changing any 0-entry into a 1-entry creates an occurrence of
+$P$. Fulek and Keszegh recently showed that the saturation function is either
+bounded or in $\Theta(n)$. Building on their results, we find a large class of
+patterns with bounded saturation function, including both infinitely many
+permutation matrices and infinitely many non-permutation matrices.",2012.14717v1
+2021-05-05,An exact characterization of saturation for permutation matrices,"A 0-1 matrix $M$ contains a 0-1 matrix pattern $P$ if we can obtain $P$ from
+$M$ by deleting rows and/or columns and turning arbitrary 1-entries into 0s.
+The saturation function $\mathrm{sat}(P,n)$ for a 0-1 matrix pattern $P$
+indicates the minimum number of 1s in an $n \times n$ 0-1 matrix that does not
+contain $P$, but changing any 0-entry into a 1-entry creates an occurrence of
+$P$. Fulek and Keszegh recently showed that each pattern has a saturation
+function either in $O(1)$ or in $\Theta(n)$. We fully classify the saturation
+functions of permutation matrices.",2105.02210v2
+2021-07-07,Nonlinear reversed shear Alfven eigenmode saturation due to spontaneous zonal current generation,"General nonlinear equations describing reversed shear Alfven eigenmode (RSAE)
+self-modulation via zero frequency zonal structure (ZFZS) generation are
+derived using nonlinear gyrokinetic theory, which are then applied to study the
+spontaneous ZFZS excitation as well as RSAE nonlinear saturation. It is found
+that both electrostatic zonal flow (ZF) and electromagnetic zonal current (ZC)
+can be preferentially excited by finite amplitude RSAE, depending on specific
+plasma parameters. The modification to local shear Alfven wave continuum is
+evaluated using the derived saturation level of ZC, which is shown to play a
+comparable role in saturating RSAE with the ZFZS scattering.",2107.02996v1
+2021-09-21,Saturation Problems in Convex Geometric Hypergraphs,"A convex geometric hypergraph (abbreviated cgh) consists of a collection of
+subsets of a strictly convex set of points in the plane. Extremal problems for
+cgh's have been extensively studied in the literature, and in this paper we
+consider their corresponding saturation problems. We asymptotically determine
+the saturation number of two geometrically disjoint $r$-tuples. Further,
+amongst the eight nonisomorphic $3$-uniform cgh's on two edges, we determine
+the saturation number for seven of these up to order of magnitude and the
+eighth up to a log factor.",2109.09931v1
+2021-11-29,Stability Analysis of a Feedback-linearization-based Controller with Saturation: A Tilt Vehicle with the Penguin-inspired Gait Plan,"Saturations in control signal can challenge the stability proof of a
+feedback-linearization-based controller, even leading the system unstable [1].
+Thus, several approaches are established to avoid reaching the saturation bound
+[2,3]. Meanwhile, to help design the controller for a quad-tilt-rotor, [1]
+modeled a tilt vehicle with implementing the feedback-linearization-based
+controllers. In this article, we provide a gait plan for this tilt vehicle and
+control it utilizing the feedback linearization. Since saturations exist in the
+control signals, we study the stability based on Lyapunov theory.",2111.14456v1
+2022-02-23,Speaker recognition improvement using blind inversion of distortions,"In this paper we propose the inversion of nonlinear distortions in order to
+improve the recognition rates of a speaker recognizer system. We study the
+effect of saturations on the test signals, trying to take into account real
+situations where the training material has been recorded in a controlled
+situation but the testing signals present some mismatch with the input signal
+level (saturations). The experimental results shows that a combination of data
+fusion with and without nonlinear distortion compensation can improve the
+recognition rates with saturated test sentences from 80% to 88.57%, while the
+results with clean speech (without saturation) is 87.76% for one microphone.",2203.01164v1
+2022-05-27,Saturation Correction to Projectile -- some ${\cal{O}}(g^5)$ results within LCPT,"We revisited the first saturation correction to projectile in nucleus-nucleus
+collisions \cite{Chirilli:2015tea} within diagrammatic light cone perturbation
+theory (LCPT). To get an analytic expression for the saturation correction in
+projectile authors in \cite{Chirilli:2015tea} calculated complete
+${\cal{O}}(g^3)$ amplitudes, where the main results are given in transverse
+coordinate space. However to find the complete first saturation correction in
+the projectile, one needs to calculate both ${\cal{O}}(g^3)$ and
+${\cal{O}}(g^5)$ gluon production amplitudes. We here present a detailed
+calculation of a sample graph at ${\cal{O}}(g^5)$ in diagrammatic light cone
+perturbation theory.",2205.13960v1
+2023-01-07,Measuring Power with a Saturated Photodiode,"Accurate measurement of optical power is pivotal in many applications and
+scientific research. However, traditional power meters are unable to measure
+power levels beyond a certain saturation point, limiting their usefulness in
+high-power applications. In this technical note, I discuss how optical power
+can be measured using a saturated photodiode. I demonstrate that by monitoring
+both the dc photocurrent and ac noise, it is possible to accurately measure
+power levels beyond its saturation point.",2301.02658v1
+2023-03-21,Some results on the saturation number for unions of cliques,"Graph $G$ is $H$-saturated if $H$ is not a subgraph of $G$ and $H$ is a
+subgraph of $G+e$ for any edge $e$ not in $G$. The saturation number for a
+graph $H$ is the minimal number of edges in any $H$-saturated graph of order
+$n$. In this paper, the saturation number for $K_p\cup (t-1)K_q$ ($t\geqslant
+3$ and $2\leqslant p<q$) is determined, and the extremal graph for $K_p\cup
+2K_q$ is determined. Moreover, the saturation number and the extremal graph for
+$K_p\cup K_q\cup K_r$ ($ r\geqslant p+q$) are completely determined.",2303.11893v2
+2023-10-05,On the Lipschitz saturation of toric singularities,"We begin the study of Lipschitz saturation for germs of toric singularities.
+By looking at their associated analytic algebras, we prove that if (X,0) is a
+germ of toric singularity with smooth normalization then its Lipschitz
+saturation is again toric. Finally we show how to calculate the Lipschitz
+saturation for some families of toric singularities starting from the semigroup
+that defines them.",2310.03216v1
+2024-02-21,Saturation of $k$-chains in the Boolean lattice,"Given a set $X$, a collection $\mathcal{F} \subset \mathcal{P}(X)$ is said to
+be $k$-Sperner if it does not contain a chain of length $k+1$ under set
+inclusion and it is saturated if it is maximal with respect to this
+probability. Gerbner et al. proved that the smallest saturated $k$-Sperner
+system contains at least $2^{k/2-1}$ elements, and later, Morrison, Noel, and
+Scott showed that the smallest such set contains no more than $2^{0.976723k}$
+elements. We improve both the upper and lower bounds, showing that the size of
+the smallest saturated $k$-Sperner system lies between $\sqrt{k}2^{k/2}$ and
+$2^{0.950978k}$.",2402.14113v2
+2024-02-24,Adjusting exceptional points using saturable nonlinearities,"We study the impact of saturable nonlinearity on the presence and location of
+exceptional points in a non-Hermitian dimer system. The inclusion of the
+saturable nonlinearity leads to the emergence of multiple eigenvalues,
+exceeding the typical two found in the linear counterpart. To identify the
+exceptional points, we calculate the nonlinear eigenvalues both from a
+polynomial equation for the defined population imbalance and through a fully
+numerical method. Our results reveal that exceptional points can be precisely
+located by adjusting the non-equal saturable nonlinearities in the detuning
+space.",2402.15792v1
+2024-04-03,Quotient-saturated groups,"We introduce the new notion of quotient-saturation as a measure of the
+immensity of the quotient structure of a group. We present a sufficient
+condition for a finitely presented group to be quotient-saturated, and use it
+to deduce that non-elementary finitely presented subgroups of a hyperbolic
+group (in particular, non-elementary hyperbolic groups themselves) are
+quotient-saturated. Finally, we elaborate on the previous results to extend the
+scope of this property to finitely presented acylindrically hyperbolic groups.",2404.03104v1
+2022-12-09,Rainbow saturation for complete graphs,"We call an edge-colored graph rainbow if all of its edges receive distinct
+colors. An edge-colored graph $\Gamma$ is called $H$-rainbow saturated if
+$\Gamma$ does not contain a rainbow copy of $H$ and adding an edge of any color
+to $\Gamma$ creates a rainbow copy of $H$. The rainbow saturation number
+$sat(n,{R}(H))$ is the minimum number of edges in an $n$-vertex $H$-rainbow
+saturated graph. Gir\~{a}o, Lewis, and Popielarz conjectured that
+$sat(n,{R}(K_r))=2(r-2)n+O(1)$ for fixed $r\geq 3$. Disproving this conjecture,
+we establish that for every $r\geq 3$, there exists a constant $\alpha_r$ such
+that $$r + \Omega\left(r^{1/3}\right) \le \alpha_r \le r + r^{1/2} \qquad
+\text{and} \qquad sat(n,{R}(K_r)) = \alpha_r n + O(1).$$ Recently, Behague,
+Johnston, Letzter, Morrison, and Ogden independently gave a slightly weaker
+upper bound which was sufficient to disprove the conjecture. They also
+introduced the weak rainbow saturation number, and asked whether this is equal
+to the rainbow saturation number of $K_r$, since the standard weak saturation
+number of complete graphs equals the standard saturation number. Surprisingly,
+our lower bound separates the rainbow saturation number from the weak rainbow
+saturation number, answering this question in the negative. The existence of
+the constant $\alpha_r$ resolves another of their questions in the affirmative
+for complete graphs. Furthermore, we show that the conjecture of Gir\~{a}o,
+Lewis, and Popielarz is true if we have an additional assumption that the
+edge-colored $K_r$-rainbow saturated graph must be rainbow. As an ingredient of
+the proof, we study graphs which are $K_r$-saturated with respect to the
+operation of deleting one edge and adding two edges.",2212.04640v2
+1992-05-07,On $c_0$-saturated Banach spaces,"A Banach space E is c_0-saturated if every closed infinite dimensional
+subspace of E contains an isomorph of c_0. A c_0-saturated Banach space with an
+unconditional basis which has a quotient space isomorphic to l^2 is
+constructed.",9205205v1
+2004-04-20,An Invitation to the Generalized Saturation Conjecture,"We report about some results, interesting examples, problems and conjectures
+revolving around the parabolic Kostant partition functions, the parabolic
+Kostka polynomials and ``saturation'' properties of several generalizations of
+the Littlewood--Richardson numbers.",0404353v2
+2004-10-25,"Expansions, omitting types, and standard systems","Recursive saturation and resplendence are two important notions in models of
+arithmetic. Kaye, Kossak, and Kotlarski introduced the notion of arithmetic
+saturation and argued that recursive saturation might not be as rigid as first
+assumed.
+  In this thesis we give further examples of variations of recursive
+saturation, all of which are connected with expandability properties similar to
+resplendence. However, the expandability properties are stronger than
+resplendence and implies, in one way or another, that the expansion not only
+satisfies a theory, but also omits a type. We conjecture that a special version
+of this expandability is in fact equivalent to arithmetic saturation. We prove
+that another of these properties is equivalent to \beta-saturation. We also
+introduce a variant on recursive saturation which makes sense in the context of
+a standard predicate, and which is equivalent to a certain amount of ordinary
+saturation.
+  The theory of all models which omit a certain type p(x) is also investigated.
+We define a proof system, which proves a sentence if and only if it is true in
+all models omitting the type p(x). The complexity of such proof systems are
+discussed and some explicit examples of theories and types with high
+complexity, in a special sense, are given.
+  We end the thesis by a small comment on Scott's problem. We prove that, under
+the assumption of Martin's axiom, every Scott set of cardinality <2^{\aleph_0}
+closed under arithmetic comprehension which has the countable chain condition
+is the standard system of some model of PA. However, we do not know if there
+exists any such uncountable Scott sets.",0410523v1
+2007-08-02,"Eigencone, saturation and Horn problems for symplectic and odd orthogonal groups","We consider the eigenvalue problem and the associated intersection theory of
+homogenous spaces for the symplectic and odd orthogonal groups. We solve the
+Horn and saturation problems for these classical groups.",0708.0398v1
+2008-12-08,Theoretical concepts of parton saturation - from HERA to LHC,"We present a short summary of parton saturation concepts as seen in deep
+inelastic scattering.",0812.1523v1
+2009-01-19,Application of the quadratures method to the NLS with saturation,"The solution of nonlinear Schroedinger equation with saturation was found by
+means the quadratures method in terms of degeneracy theory. It was shown the
+existence conditions for soliton solutions.",0901.2796v1
+2009-08-27,Asymptotics of Canonical and Saturated RNA Secondary Structures,"It is a classical result of Stein and Waterman that the asymptotic number of
+RNA secondary structures is $1.104366 n^{-3/2} 2.618034^n$. In this paper, we
+study combinatorial asymptotics for two special subclasses of RNA secondary
+structures - canonical and saturated structures. Canonical secondary structures
+were introduced by Bompf\""unewerer et al., who noted that the run time of
+Vienna RNA Package is substantially reduced when restricting computations to
+canonical structures. Here we provide an explanation for the speed-up.
+Saturated secondary structures have the property that no base pairs can be
+added without violating the definition of secondary structure (i.e. introducing
+a pseudoknot or base triple). Here we compute the asymptotic number of
+saturated structures, we show that the asymptotic expected number of base pairs
+is $0.337361 n$, and the asymptotic number of saturated stem-loop structures is
+$0.323954 1.69562^n$, in contrast to the number $2^{n-2}$ of (arbitrary)
+stem-loop structures as classically computed by Stein and Waterman. Finally, we
+show that the density of states for [all resp. canonical resp. saturated]
+secondary structures is asymptotically Gaussian. We introduce a stochastic
+greedy method to sample random saturated structures, called quasi-random
+saturated structures, and show that the expected number of base pairs of is
+$0.340633 n$.",0908.4003v1
+2010-10-04,Sharp upper bounds of the Betti numbers for a given Hilbert polynomial,"We show that there exists a saturated graded ideal in a standard graded
+polynomial ring which has the largest total Betti numbers among all saturated
+graded ideals for a fixed Hilbert polynomial.",1010.0457v1
+2011-09-07,Saturation of uncertainty relations for twisted acceleration-enlarged Newton-Hooke space-times,"Using Fock representation we construct states saturating uncertainty
+relations for twist-deformed acceleration-enlarged Newton-Hooke space-times.",1109.1428v1
+2011-11-18,Gluon Saturation in QCD at High Energy: Beyond Leading Logarithms,"Progresses towards the calculation and the understanding of NLO/NLL
+contributions to Deep Inelastic Scattering at low x with gluon saturation are
+being reviewed.",1111.4440v1
+2012-09-17,The saturation property for branching rules -- Examples,"For a few pairs $G\subset \hat G$ of reductive groups, we study the
+decomposition of irreducible $\hait G$-modules into $G$-modules. In particular,
+we observe the saturation property for all of these pairs.",1209.3589v1
+2014-05-22,Saturation algorithms for model-checking pushdown systems,"We present a survey of the saturation method for model-checking pushdown
+systems.",1405.5593v1
+2015-12-05,Sets of Completely Decomposed Primes in Extensions of Number Fields,"We introduce the notion of saturated sets of primes of an algebraic number
+field and prove an analogue of Riemann's existence theorem for the
+decomposition groups of infinite stably saturated sets of primes.",1512.01694v1
+2016-10-08,Anderson localization and saturable nonlinearity in one-dimensional disordered lattices,"We investigate numerically the propagation and the Anderson localization of
+plane waves in a one-dimensional lattice chain, where disorder and saturable
+nonlinearity are simultaneously present. Using a calculation scheme for solving
+the stationary discrete nonlinear Schr\""{o}dinger equation in the fixed input
+case, the disorder-averaged logarithmic transmittance and the localization
+length are calculated in a numerically precise manner. The localization length
+is found to be a nonmonotonic function of the incident wave intensity,
+acquiring a minimum value at a certain finite intensity, due to saturation
+effects. For low incident intensities where the saturation effect is
+ineffective, the enhancement of localization due to Kerr-type nonlinearity
+occurs in a way similar to the case without saturation. For sufficiently high
+incident intensities, we find that the localization length is an increasing
+function of the incident wave intensity, which implies that localization is
+suppressed for stronger input intensities, and ultimately approaches a
+saturation value. This feature is associated with the fact that the nonlinear
+system is reduced to an effectively linear one, when either the incident wave
+intensity or the saturation parameter is sufficiently large. We also find that
+the nonlinear saturation effect is stronger and more pronounced when the energy
+of the incident wave is larger.",1610.02521v1
+2017-09-21,Particle-in-cell simulation of Buneman instability beyond quasilinear saturation,"Spatio-temporal evolution of Buneman instability has been followed
+numerically till its quasilinear quenching and beyond, using an in-house
+developed electrostatic 1D particle-in-cell simulation code. For different
+initial drift velocities $k_{L}v_{0}/\omega_{pe} \approx 0.1 \, - \, 1$ and for
+a wide range of electron to ion mass ratios (m/M), growth rate obtained from
+simulation agrees well with the numerical solution of the fourth order
+dispersion relation. Quasi-linear saturation of Buneman instability occurs when
+ratio of electrostatic field energy density ($\sum\limits_{k}
+|E_{k}|^{2}/8{\pi}$) to initial electron drift kinetic energy density ($W_{0} =
+\frac{1}{2} n_{0}m v^{2}_{0}$) reaches up to a constant value, which as
+predicted by Hirose [Plasma Physics 20, 481(1978)], is independent of initial
+electron drift velocity but depends on electron to ion mass ratio m/M as
+$\sum\limits_{k} |E_{k}|^{2}/16{\pi}W_{0} \approx (m/M)^{1/3}$. This result
+stands verified in our simulations. Growth of the instability beyond the first
+saturation (quasilinear saturation ) till its final saturation [Ishihara et.
+al., PRL 44, 1404(1980)] follows an algebraic scaling with time. In contrast to
+the quasilinear saturation, the ratio of final saturated electrostatic field
+energy density to initial kinetic energy density, is relatively independent of
+electron to ion mass ratio and is found to depend only on the initial drift
+velocity. Beyond the final saturation, electron phase space holes coupled to
+large amplitude ion solitary waves, a state known as coupled hole-soliton , are
+seen in our simulations. The propagation characteristics ( amplitude - speed
+relation ) of these coherent modes is found to be consistent with the theory of
+Saeki et. al. [PRL 80, 1224(1998)].",1709.07478v1
+2017-10-13,Finite saturation for unirational varieties,"We import ideas from geometry to settle Sarnak's saturation problem for a
+large class of algebraic varieties.",1710.04962v3
+2018-02-21,Dynamics of Viscous Entrapped Saturated Zones in Partially Wetted Porous Media,"As a typical multiphase fluid flow process, drainage in porous media is of
+fundamental interest in nature and industrial applications. During drainage
+processes in unsaturated soils and porous media in general, saturated clusters,
+in which a liquid phase fully occupies the pore space between solid grains,
+affect the relative permeability and effective stress of the system. In this
+study, we experimentally studied drainage processes in unsaturated granular
+media as a model porous system. The distribution of saturated clusters is
+analysed by an optical imaging method under different drainage conditions, in
+which pore-scale information from Voronoi and Delaunay tessellation was used to
+characterise the topology of saturated cluster distributions. By employing
+statistical analyses, the observed spatial and temporal information of
+multiphase flow and fluid entrapment in porous media are described. The results
+indicate that the distributions of both the crystallised cell size and pore
+size are positively correlated to the spatial and temporal distribution of
+saturated cluster sizes. The saturated cluster size is found to follow a
+lognormal distribution, in which the generalised Bond number correlates
+negatively to the scale parameter and positively to the shape parameter. These
+findings can be used to connect pore-scale behaviour with overall
+hydro-mechanical characteristics in partially saturated porous media, using
+both the degree of saturation and generalised Bond number.",1802.07387v1
+2019-06-08,Splitting-based domain decomposition methods for two-phase flow with different rock types,"In this paper, we are concerned with the global pressure formulation of
+immiscible incompressible two-phase flow between different rock types. We
+develop for this problem two robust schemes based on domain decomposition (DD)
+methods and operator-splitting techniques. The first scheme follows a
+sequential procedure in which the (global) pressure, the saturation-advection
+and the saturation-diffusion problems are fully decoupled. In this scheme, each
+problem is treated individually using various DD approaches and specialized
+numerical methods. The coupling between the different problems is explicit and
+the time-marching is with no iterations. To adapt to different time scales of
+problem components and different rock types, the novel scheme uses a multirate
+time stepping strategy, by taking multiple finer time steps for
+saturation-advection within one coarse time step for saturation-diffusion and
+pressure, and permits independent time steps for the advection step in the
+different rocks. In the second scheme, we review the classical Implicit
+Pressure--Explicit Saturation (IMPES) method (by decoupling only pressure and
+saturation) in the context of multirate coupling schemes and
+nonconforming-in-time DD approaches. For the discretization, the
+saturation-advection problem is approximated with the explicit Euler method in
+time, and in space with the cell-centered finite volume method of first order
+of Godunov type. The saturation-diffusion problem is approximated in time with
+the implicit Euler method and in space with the mixed finite element method, as
+in the pressure problem. Finally, in a series of numerical experiments, we
+investigate the practicality of the proposed schemes, the accuracy-in-time of
+the multirate and nonconforming time strategies, and compare the convergence of
+various DD methods within each approach.",1906.03470v2
+2021-05-10,Examining and Mitigating Kernel Saturation in Convolutional Neural Networks using Negative Images,"Neural saturation in Deep Neural Networks (DNNs) has been studied
+extensively, but remains relatively unexplored in Convolutional Neural Networks
+(CNNs). Understanding and alleviating the effects of convolutional kernel
+saturation is critical for enhancing CNN models classification accuracies. In
+this paper, we analyze the effect of convolutional kernel saturation in CNNs
+and propose a simple data augmentation technique to mitigate saturation and
+increase classification accuracy, by supplementing negative images to the
+training dataset. We hypothesize that greater semantic feature information can
+be extracted using negative images since they have the same structural
+information as standard images but differ in their data representations. Varied
+data representations decrease the probability of kernel saturation and thus
+increase the effectiveness of kernel weight updates. The two datasets selected
+to evaluate our hypothesis were CIFAR- 10 and STL-10 as they have similar image
+classes but differ in image resolutions thus making for a better understanding
+of the saturation phenomenon. MNIST dataset was used to highlight the
+ineffectiveness of the technique for linearly separable data. The ResNet CNN
+architecture was chosen since the skip connections in the network ensure the
+most important features contributing the most to classification accuracy are
+retained. Our results show that CNNs are indeed susceptible to convolutional
+kernel saturation and that supplementing negative images to the training
+dataset can offer a statistically significant increase in classification
+accuracies when compared against models trained on the original datasets. Our
+results present accuracy increases of 6.98% and 3.16% on the STL-10 and
+CIFAR-10 datasets respectively.",2105.04128v1
+2021-09-08,Weak saturation of multipartite hypergraphs,"Given $q$-uniform hypergraphs ($q$-graphs) $F,G$ and $H$, where $G$ is a
+spanning subgraph of $F$, $G$ is called weakly $H$-saturated in $F$ if the
+edges in $E(F)\setminus E(G)$ admit an ordering $e_1,\dots, e_k$ so that for
+all $i\in [k]$ the hypergraph $G\cup \{e_1,\dots,e_i\}$ contains an isomorphic
+copy of $H$ which in turn contains the edge $e_i$. The weak saturation number
+of $H$ in $F$ is the smallest size of an $H$-weakly saturated subgraph of $F$.
+Weak saturation was introduced by Bollob\'as in 1968, but despite decades of
+study our understanding of it is still limited. The main difficulty lies in
+proving lower bounds on weak saturation numbers, which typically withstands
+combinatorial methods and requires arguments of algebraic or geometrical
+nature.
+  In our main contribution in this paper we determine exactly the weak
+saturation number of complete multipartite $q$-graphs in the directed setting,
+for any choice of parameters. This generalizes a theorem of Alon from 1985. Our
+proof combines the exterior algebra approach from the works of Kalai with the
+use of the colorful exterior algebra motivated by the recent work of Bulavka,
+Goodarzi and Tancer on the colorful fractional Helly theorem. In our second
+contribution answering a question of Kronenberg, Martins and Morrison, we
+establish a link between weak saturation numbers of bipartite graphs in the
+clique versus in a complete bipartite host graph. In a similar fashion we
+asymptotically determine the weak saturation number of any complete $q$-partite
+$q$-graph in the clique, generalizing another result of Kronenberg et al.",2109.03703v2
+2021-11-25,Sketch-Guided Equality Saturation: Scaling Equality Saturation to Complex Optimizations of Functional Programs,"Generating high-performance code for diverse hardware and application domains
+is challenging. Functional array programming languages with patterns like map
+and reduce have been successfully combined with term rewriting to define and
+explore optimization spaces. However, deciding what sequence of rewrites to
+apply is hard and has a huge impact on the performance of the rewritten
+program. Equality saturation avoids the issue by exploring many possible ways
+to apply rewrites, efficiently representing many equivalent programs in an
+e-graph data structure.
+  Equality saturation has some limitations when rewriting functional language
+terms, as currently naive encodings of the lambda calculus are used. We present
+new techniques for encoding polymorphically typed lambda calculi, and show that
+the efficient encoding reduces the runtime and memory consumption of equality
+saturation by orders of magnitude.
+  Moreover, equality saturation does not yet scale to complex compiler
+optimizations. These emerge from long rewrite sequences of thousands of rewrite
+steps, and may use pathological combinations of rewrite rules that cause the
+e-graph to quickly grow too large. This paper introduces \emph{sketch-guided
+equality saturation}, a semi-automatic technique that allows programmers to
+provide program sketches to guide rewriting. Sketch-guided equality saturation
+is evaluated for seven complex matrix multiplication optimizations, including
+loop blocking, vectorization, and multi-threading. Even with efficient lambda
+calculus encoding, unguided equality saturation can locate only the two
+simplest of these optimizations, the remaining five are undiscovered even with
+an hour of compilation time and 60GB of RAM. By specifying three or fewer
+sketch guides all seven optimizations are found in seconds of compilation time,
+using under 1GB of RAM, and generating high performance code.",2111.13040v2
+2021-12-06,Saturated Models for the Working Model Theorist,"We put in print a classical result that states that for most purposes, there
+is no harm in assuming the existence of saturated models in model theory. The
+presentation is aimed for model theorists with only basic knowledge of
+axiomatic set theory.",2112.02774v1
+2023-05-20,Ultra-fast Graphene-Plasmonic Hybrid Metasurface Saturable Absorber with Low Saturation Fluence,"Exploring novel materials with enhanced optical nonlinearities at low power
+levels with ultrafast response and small footprints is of great interests for
+information processing, communication, sensing and quantum systems. Recent
+progress on nonlinear metamaterials and metasurfaces suggests promising
+solutions to overcome the limitations of nonlinear materials in nature. Here we
+present a design concept for highly enhanced saturable absorption effect based
+on subwavelength-thick (<1/5$\lambda$0) hybrid graphene-plasmonic metasurface
+structures in infrared wavelengths. Our theoretical and experimental results
+demonstrated that, by exciting nonequilibrium carriers inside nanoscale
+hotspots, one could not only enhance the saturable absorption in graphene, but
+also reduce the saturation fluence by over 3 orders of magnitude (from ~ 1
+mJ/cm2 to ~100 nJ/cm2). Our pump-probe measurement results suggested an
+ultrashort saturable absorption recovery time (<60 fs), which is ultimately
+determined by the relaxation dynamics of photoexcited carriers in graphene. We
+also observed pulse narrowing effects in our devices based on the
+autocorrelation measurement results. Such design concepts can be tailored via
+structure engineering to operate in broader wavelength ranges up to mid- and
+far- infrared spectral regions. These ultrafast low-saturation fluence
+saturable absorber designs can enable low-threshold, compact, self-starting
+mode-locked lasers, laser pulse shaping, and high-speed optical information
+processing.",2305.12136v1
+2023-07-13,On stepwise advancement of fractures and pressure oscillations in saturated porous media,"Comments to K.M. Pervaiz Fathima, Ren\'e de Borst, Implications of single or
+multiple pressure degrees of freedom at fracture in fluid saturated porous
+media, Engineering Fracture Mechanics, 213 (2019), 1-20.",2307.06960v1
+2023-10-16,A saturated 1-system of curves on the surface of genus 3,"We construct a saturated system of 33 essential simple closed curves that are
+pairwise non-homotopic and intersect at most once on the oriented, closed
+surface of genus 3.",2310.10814v2
+1999-11-16,Nonlinear r-modes in a spherical shell: issues of principle,"We use a simple physical model to study the nonlinear behaviour of the r-mode
+instability. We assume that r-modes (Rossby waves) are excited in a thin
+spherical shell of rotating incompressible fluid. For this case, exact Rossby
+wave solutions of arbitrary amplitude are known. We find that:
+  (a) These nonlinear Rossby waves carry ZERO physical angular momentum and
+positive physical energy, which is contrary to the folklore belief that the
+r-mode angular momentum and energy are negative.
+  (b) Within our model, we confirm the differential drift reported by Rezzolla,
+Lamb and Shapiro (1999).
+  Radiation reaction is introduced into the model by assuming that the fluid is
+electrically charged; r-modes are coupled to electromagnetic radiation through
+current (magnetic) multipole moments. We find that:
+  (c) To linear order in the mode amplitude, r-modes are subject to the CFS
+instability, as expected.
+  (d) Radiation reaction decreases the angular velocity of the shell and causes
+differential rotation (which is distinct from but similar in magnitude to the
+differential drift reported by Rezzolla et al.) prior to saturation of the
+r-mode growth. This is contrary to the phenomenological treatments to date,
+which assume that the loss of stellar angular momentum is accounted for by the
+r-mode growth. We demonstrate, for the first time, that r-mode radiation
+reaction leads to differential rotation.
+  (e) We show that for l=2 r-mode electromagnetic radiation reaction is
+equivalent to gravitational radiation reaction in the lowest post-Newtonian
+order.",9911295v1
+2002-01-11,The Effect of the Hall Term on the Nonlinear Evolution of the Magnetorotational Instability: I. Local Axisymmetric Simulations,"The effect of the Hall term on the evolution of the magnetorotational
+instability (MRI) in weakly ionized accretion disks is investigated using local
+axisymmetric simulations. First, we show that the Hall term has important
+effects on the MRI when the temperature and density in the disk is below a few
+thousand K and between 10^13 and 10^18 cm^{-3} respectively. Such conditions
+can occur in the quiescent phase of dwarf nova disks, or in the inner part
+(inside 10 - 100 AU) of protoplanetary disks. When the Hall term is important,
+the properties of the MRI are dependent on the direction of the magnetic field
+with respect to the angular velocity vector \Omega. If the disk is threaded by
+a uniform vertical field oriented in the same sense as \Omega, the axisymmetric
+evolution of the MRI is an exponentially growing two-channel flow without
+saturation. When the field is oppositely directed to \Omega, however, small
+scale fluctuations prevent the nonlinear growth of the channel flow and the MRI
+evolves into MHD turbulence. These results are anticipated from the
+characteristics of the linear dispersion relation. In axisymmetry on a field
+with zero-net flux, the evolution of the MRI is independent of the size of the
+Hall term relative to the inductive term. The evolution in this case is
+determined mostly by the effect of ohmic dissipation.",0201179v1
+2002-03-18,Activity at the Deuterium-Burning Mass Limit in Orion,"We report very intense and variable Halpha emission (pseudo-equivalent widths
+of ~180, 410 A) of S Ori 55, a probable free-floating, M9-type substellar
+member of the young sigma Orionis open star cluster. After comparison with
+state-of-the-art evolutionary models, we infer that S Ori 55 is near or below
+the cluster deuterium-burning mass borderline, which separates brown dwarfs and
+planetary-mass objects. We find its mass to be 0.008-0.015 Msun for ages
+between 1 Myr and 8 Myr, with ~0.012 Msun the most likely value at the cluster
+age of 3 Myr. The largest Halpha intensity reached the saturation level of log
+L(Halpha)/L(bol) = -3. We discuss several possible scenarios for such a strong
+emission. We also show that sigma Orionis M and L dwarfs have in general more
+Halpha emission than their older field spectral counterparts. This could be due
+to a decline in the strength of the magnetic field with age in brown dwarfs and
+isolated planetary-mass objects, or to a likely mass accretion from disks in
+the very young sigma Orionis substellar members.",0203283v1
+2003-11-09,Formation of current sheets and sigmoidal structure by the kink instability of a magnetic loop,"We study dynamical consequences of the kink instability of a twisted coronal
+flux rope, using the force-free coronal loop model by Titov & D\'emoulin (1999)
+as the initial condition in ideal-MHD simulations. When a critical value of the
+twist is exceeded, the long-wavelength ($m=1$) kink mode develops. Analogous to
+the well-known cylindrical approximation, a helical current sheet is then
+formed at the interface with the surrounding medium. In contrast to the
+cylindrical case, upward-kinking loops form a second, vertical current sheet
+below the loop apex at the position of the hyperbolic flux tube (generalized X
+line) in the model. The current density is steepened in both sheets and
+eventually exceeds the current density in the loop (although the kink
+perturbation starts to saturate in our simulations without leading to a global
+eruption). The projection of the field lines that pass through the vertical
+current sheet shows an S shape whose sense agrees with the typical sense of
+transient sigmoidal (forward or reverse S-shaped) structures that brighten in
+soft X rays prior to coronal eruptions. The upward-kinked loop has the opposite
+S shape, leading to the conclusion that such sigmoids do not generally show the
+erupting loops themselves but indicate the formation of the vertical current
+sheet below them that is the central element of the standard flare model.",0311199v1
+2004-01-15,On the deep minimum state in the Seyfert galaxy MCG-6-30-15,"(abridged) We present a detailed spectral analysis of the first observation
+of the Seyfert 1 galaxy MCG-6-30-15 by the European Photon Imaging Camera on
+board the XMM-Newton observatory, together with contemporaneous data from the
+Proportional Counter Array on the Rossi X-ray Timing Explorer. Confirming our
+previously published result, we find that the presence of extremely broadened
+reflection features from an ionized relativistic accretion disk is required
+even when one employs the latest X-ray reflection models and includes the
+effect of complex absorption. The extremely broadened reflection features are
+also present if the primary continuum is modeled with a thermal Comptonisation
+spectrum rather than a simple power-law continuum. With this fact established,
+we examine these data using a relativistic smearing function corresponding to a
+``generalized thin accretion disk'' model. We find strong evidence for torquing
+of the central parts of the accretion disk (presumably through magnetic
+interactions with the plunging region of the disk and/or the rotating black
+hole itself). We also perform a study of spectral variability within our
+observation. We find that the disk reflection features maintain roughly a
+constant equivalent width with respect to the observed continuum, as predicted
+by simple reflection models. Taken together with other studies of MCG-6-30-15
+that find disk features to possess constant intensity at higher flux states, we
+suggest that the flux of disk features undergoes a saturation once the source
+emerges from a Deep Minimum state.",0401305v1
+2004-01-22,Thermal conduction in cosmological SPH simulations,"Thermal conduction in the intracluster medium has been proposed as a possible
+heating mechanism for offsetting central cooling losses in rich clusters of
+galaxies. In this study, we introduce a new formalism to model conduction in a
+diffuse ionised plasma using smoothed particle hydrodynamics (SPH), and we
+implement it in the parallel TreePM/SPH-code GADGET-2. We consider only
+isotropic conduction and assume that magnetic suppression can be described in
+terms of an effective conductivity, taken as a fixed fraction of the
+temperature-dependent Spitzer rate. We also account for saturation effects in
+low-density gas. Our formulation manifestly conserves thermal energy even for
+individual and adaptive timesteps, and is stable in the presence of small-scale
+temperature noise. This allows us to evolve the thermal diffusion equation with
+an explicit time integration scheme along with the ordinary hydrodynamics. We
+use a series of simple test problems to demonstrate the robustness and accuracy
+of our method. We then apply our code to spherically symmetric realizations of
+clusters, constructed under the assumptions of hydrostatic equilibrium and a
+local balance between conduction and radiative cooling. While we confirm that
+conduction can efficiently suppress cooling flows for an extended period of
+time in these isolated systems, we do not find a similarly strong effect in a
+first set of clusters formed in self-consistent cosmological simulations.
+However, their temperature profiles are significantly altered by conduction, as
+is the X-ray luminosity.",0401456v3
+2004-12-15,Magnetospheric eclipses in the double pulsar system J0737-3039,"We argue that eclipses of radio emission from the millisecond pulsar A in the
+double pulsar system J0737-3039 are due to synchrotron absorption by plasma in
+the closed field line region of the magnetosphere of its normal pulsar
+companion B. A's radio beam only illuminates B's magnetosphere for about 10
+minutes surrounding the time of eclipse. During this time it heats particles at
+r\gtrsim 10^9 cm to relativistic energies and enables extra plasma to be
+trapped by magnetic mirroring. An enhancement of the plasma density by a factor
+\sim 10^2 is required to match the duration and optical depth of the observed
+eclipses. The extra plasma might be supplied by a source near B through B\gamma
+pair creation by energetic photons produced in B's outer gap. Excitation of
+pairs' gyrational motions by cyclotron absorption of A's radio beam can result
+in their becoming trapped between conjugate mirror points in B's magnetosphere.
+Because the trapping efficiency decreases with increasing optical depth, the
+plasma density enhancement saturates even under steady state illumination. The
+result is an eclipse with finite, frequency dependent, optical depth. After
+illumination by A's radio beam ceases, the trapped particles cool and are lost.
+The entire cycle repeats every orbital period. We speculate that the
+asymmetries between eclipse ingress and egress result in part from the
+magnetosphere's evolution toward a steady state when illuminated by A's radio
+beam. We predict that A's linear polarization will vary with both eclipse phase
+and B's rotational phase.",0412355v3
+2005-09-13,Nonlinear Photon Bubbles Driven by Buoyancy,"We derive an analytic model for nonlinear ""photon bubble"" wave trains driven
+by buoyancy forces in magnetized, radiation pressure-dominated atmospheres.
+Continuous, periodic wave solutions exist when radiative diffusion is slow
+compared to the dynamical timescale of the atmosphere. We identify these waves
+with the saturation of a linear instability discovered by Arons - therefore,
+these wave trains should develop spontaneously. The buoyancy-driven waves are
+physically distinct from photon bubbles in the presence of rapid diffusion,
+which evolve into trains of gas pressure-dominated shocks as they become
+nonlinear.
+  Like the gas pressure-driven shock trains, buoyancy-driven photon bubbles can
+exhibit very large density contrasts, which greatly enhance the flow of
+radiation through the atmosphere. However, steady-state solutions for
+buoyancy-driven photon bubbles exist only when an extra source of radiation is
+added to the energy equation, in the form of a flux divergence. We argue that
+this term is required to compensate for the radiation flux lost via the
+bubbles, which increases with height. We speculate that an atmosphere subject
+to buoyancy-driven photon bubbles, but lacking this compensating energy source,
+would lose pressure support and collapse on a timescale much shorter than the
+radiative diffusion time in the equivalent homogeneous atmosphere.",0509357v1
+2006-03-08,The signature of the magnetorotational instability in the Reynolds and Maxwell stress tensors in accretion discs,"The magnetorotational instability is thought to be responsible for the
+generation of magnetohydrodynamic turbulence that leads to enhanced outward
+angular momentum transport in accretion discs. Here, we present the first
+formal analytical proof showing that, during the exponential growth of the
+instability, the mean (averaged over the disc scale-height) Reynolds stress is
+always positive, the mean Maxwell stress is always negative, and hence the mean
+total stress is positive and leads to a net outward flux of angular momentum.
+More importantly, we show that the ratio of the Maxwell to the Reynolds
+stresses during the late times of the exponential growth of the instability is
+determined only by the local shear and does not depend on the initial spectrum
+of perturbations or the strength of the seed magnetic. Even though we derived
+these properties of the stress tensors for the exponential growth of the
+instability in incompressible flows, numerical simulations of shearing boxes
+show that this characteristic is qualitatively preserved under more general
+conditions, even during the saturated turbulent state generated by the
+instability.",0603178v2
+2007-02-26,Modeling time delays in the X-ray spectrum of the Seyfert galaxy MCG-6-30-15,"We propose a reflection model of the time delays detected during an
+exceptionally bright, single flare in MCG-6-30-15. We consider a scenario in
+which the delays of the hard X-rays with respect to the soft X-rays are caused
+by the presence of the delayed reflection component. We employ a model of the
+flare, which is accompanied by reprocessed emission. We consider two
+geometries/thermal states of the reprocessing medium: a partially ionized
+accretion disk surface and a distribution of magnetically confined, cold blobs.
+The reprocessing by cold blobs predicts positive time delays and a saturation
+in the time delay -- energy relation, which is likely present in the data. The
+model requires a strong reflection component and relies on the apparent
+pivoting of the combined primary and reflected spectrum. The reflection by the
+ionized disk surface does not reproduce the observed delays. We discuss the
+relation between the two reflection scenarios and argue that they are both
+present in MCG-6-30-15.",0702685v1
+1999-12-07,Quantum Resonances and Regularity Islands in Quantum Maps,"We study analytically as well as numerically the dynamics of a quantum map
+near a quantum resonance of an order q. The map is embedded into a continuous
+unitary transformation generated by a time-independent quasi-Hamiltonian. Such
+a Hamiltonian generates at the very point of the resonance a local gauge
+transformation described the unitary unimodular group SU(q). The resonant
+energy growth of is attributed to the zero Liouville eigenmodes of the
+generator in the adjoint representation of the group while the non-zero modes
+yield saturating with time contribution. In a vicinity of a given resonance,
+the quasi-Hamiltonian is then found in the form of power expansion with respect
+to the detuning from the resonance. The problem is related in this way to the
+motion along a circle in a (q^2-1)-component inhomogeneous ""magnetic"" field of
+a quantum particle with $q$ intrinsic degrees of freedom described by the SU(q)
+group. This motion is in parallel with the classical phase oscillations near a
+non-linear resonance. The most important role is played by the resonances with
+the orders much smaller than the typical localization length, q << l. Such
+resonances master for exponentially long though finite times the motion in some
+domains around them. Explicit analytical solution is possible for a few lowest
+and strongest resonances.",9912009v1
+1995-12-26,The Hubbard Model: Introduction and Selected Rigorous Results,"The Hubbard model is a ""highly oversimplified model"" for electrons in a solid
+which interact with each other through extremely short ranged repulsive
+(Coulomb) interaction. The Hamiltonian of the Hubbard model consists of two
+pieces; H_hop which describes quantum mechanical hopping of electrons, and Hint
+which describes nonlinear repulsive interaction. Either H_hop or H_int alone is
+easy to analyze, and does not favor any specific order. But their sum
+H=H_hop+H_int is believed to exhibit various nontrivial phenomena including
+metal-insulator transition, antiferromagnetism, ferrimagnetism, ferromagnetism,
+Tomonaga-Luttinger liquid, and superconductivity. It is believed that we can
+find various interesting ""universality classes"" of strongly interacting
+electron systems by studying the idealized Hubbard model.
+  In the present article we review some mathematically rigorous results on the
+Hubbard model which shed light on ""physics"" of this fascinating model. We
+mainly concentrate on magnetic properties of the model at its ground states. We
+discuss Lieb-Mattis theorem on the absence of ferromagnetism in one dimension,
+Koma-Tasaki bounds on decay of correlations at finite temperatures in
+two-dimensions, Yamanaka-Oshikawa-Affleck theorem on low-lying excitations in
+one-dimension, Lieb's important theorem for half-filled model on a bipartite
+lattice, Kubo-Kishi bounds on the charge and superconducting susceptibilities
+of half-filled models at finite temperatures, and three rigorous examples of
+saturated ferromagnetism due to Nagaoka, Mielke, and Tasaki. We have tried to
+make the article accessible to nonexperts by describing basic definitions and
+elementary materials in detail.",9512169v4
+1998-07-18,Delta-Function Bose Gas Picture of S=1 Antiferromagnetic Quantum Spin Chains Near Critical Fields,"We study the zero-temperature magnetization curve (M-H curve) of the S=1
+bilinear-biquadratic spin chain, whose Hamiltonian is given by $H=\sum_{i} S_i
+S_{i+1}+\beta (S_iS_{i+1})^2 with $0 \leq \beta <1$. We focus on validity of
+the delta-function bose-gas picture near the two critical fields: the
+saturation field $H_s$ and the lower critical field $H_c$ associated with the
+Haldane gap. Near $H_s$, we take ``low-energy effective S-matrix'' approach,
+which gives correct effective bose-gas coupling constant $c$, different from
+the spin-wave value. Comparing the M-H curve of the bose gas with the
+product-wavefunction renormalization group (PWFRG) calculation, excellent
+agreement is seen. Near $H_c$, comparing the PWFRG result with the bose-gas
+prediction, we find that there are two distinct regions of $\beta$ separated by
+a critical value $\beta_c(\approx 0.41)$. In the region $0<\beta<\beta_c$, the
+effective coupling $c$ is positive but rather small. The small value of $c$
+makes the ``critical region'' of the square-root behavior $M\sim \sqrt{H-H_c}$
+very narrow. Further, we find that in the $\beta \to \beta_c-0$, the
+square-root behavior transmutes to a different one, $M\sim (H-H_c)^{1/4}$. In
+the region $\beta_c<\beta <1$, the square-root behavior is rather distinct, but
+the effective coupling $c$ becomes negative.",9807266v1
+1999-08-16,Structural instability associated with the tilting of CuO6 octahedra in La2-xSrxCuO4,"Comprehensive inelastic neutron-scattering measurements were performed to
+study the soft optical phonons in La2-xSrxCuO4 at x=0.10, 0.12 and 0.18. We
+found at x=0.18 that the softening of Z-point phonon, suggesting incipient
+structural transition from the low-temperature orthorhombic (LTO) to
+low-temperature tetragonal (LTT) phase, breaks at Tc, which is consistent with
+the previous report by Lee et al. for the optimally doped x=0.15 sample. As for
+x=0.10 and 0.12, on the other hand, the softening continues even below Tc. It
+is thus clarified that the breaking of soft phonon is characteristic of
+La2-xSrxCuO4 in the optimally and overdoped regions. In the course of studying
+the soft phonons, we discovered that a central peak remains above the LTO to
+high-temperature tetragonal (HTT) phase transition at Ts1 and splits into
+incommensurate components along the (1 1 0)HTT direction at higher
+temperatures. This is a common feature for both x=0.12 and 0.18 and their
+temperature dependences of the splitting 2d can be scaled by using a
+renormalized temperature T/Ts1. In the high temperature limit, d saturates
+around d ~ 0.12 r.l.u., which value is close to the splitting of incommensurate
+magnetic signals. This implies that the incipient lattice modulation starts
+appearing at very high temperature. Details of this modulation and its
+relations with other properties are, however, not yet clarified.",9908217v1
+2001-10-31,Electrodynamic response of MgB2 sintered pellets and thin films,"We present a study of the electrodynamic response of MgB2 pellets and thin
+film samples exhibiting critical temperatures ranging between 26 and 38 K. We
+have performed accurate measurements of the surface impedance ZS =RS+iXS as a
+function of the temperature and of the magnitude of the electromagnetic field.
+The temperature variation and the field dependence of ZS was measured by a
+dielectric resonator cavity technique in the microwave region. In particular,
+the temperature variation of the magnetic penetration depth was also determined
+in the RF region by a single coil mutual inductance method. In the case of the
+films, for T<TC/2 a clear exponential behavior of the penetration depth is
+observed, which can be explained by a simple BCS s-wave model with a reduced
+value of the energy gap. On the contrary, pellets show no evidence of
+saturation, and the experimental results strictly follow a quadratic dependence
+down to the lowest temperatures. This behavior can be induced by the presence
+of metallic Mg inclusions that may locally depress the gap. The analysis of the
+field dependence of the surface impedance in the microwave region confirms that
+the electrodynamic response of MgB2 is dominated by different sources of
+dissipation, depending on the sample history, likely to be ascribed to the
+predominance of grain boundaries or normal regions on its surface.",0110640v1
+2004-03-11,Magnetoresistance and dephasing in a two-dimensional electron gas at intermediate conductances,"We study, both theoretically and experimentally, the negative
+magnetoresistance (MR) of a two-dimensional (2D) electron gas in a weak
+transverse magnetic field $B$. The analysis is carried out in a wide range of
+zero-$B$ conductances $g$ (measured in units of $e^2/h$), including the range
+of intermediate conductances, $g\sim 1$. Interpretation of the experimental
+results obtained for a 2D electron gas in GaAs/In$_x$Ga$_{1-x}$As/GaAs single
+quantum well structures is based on the theory which takes into account terms
+of higher orders in $1/g$, stemming from both the interference contribution and
+the mutual effect of weak localization (WL) and Coulomb interaction. We
+demonstrate that at intermediate conductances the negative MR is described by
+the standard WL ""digamma-functions"" expression, but with a reduced prefactor
+$\alpha$. We also show that at not very high $g$ the second-loop corrections
+dominate over the contribution of the interaction in the Cooper channel, and
+therefore appear to be the main source of the lowering of the prefactor,
+$\alpha\simeq 1-2/\pi g$. We further analyze the regime of a ""weak insulator"",
+when the zero-$B$ conductance is low $g(B=0)<1$ due to the localization at low
+$T$, whereas the Drude conductance is high, $g_0>>1.$ In this regime, while the
+MR still can be fitted by the digamma-functions formula, the experimentally
+obtained value of the dephasing rate has nothing to do with the true one. The
+corresponding fitting parameter in the low-$T$ limit is determined by the
+localization length and may therefore saturate at $T\to 0$, even though the
+true dephasing rate vanishes.",0403289v1
+2004-04-06,Anomalous scaling behavior of the dynamical spin susceptibility of Ce$_{0.925}$La$_{0.075}$Ru$_{2}$Si$_{2}$,"Inelastic neutron scattering measurements have been performed on single
+crystals of the heavy fermion compound Ce$_{0.925}$La$_{0.075}$Ru$_{2}$Si$_{2}$
+in broad energy [0.1, 9.5 meV] and temperature [40 mK, 294 K] ranges in order
+to address the question of scaling behavior of the dynamical spin
+susceptibility at the quantum critical point of an itinerant magnetic system.
+For two wavevectors $\mathbf{Q}$ corresponding to uncorrelated and
+antiferromagnetically correlated spin fluctuations, it is found that the
+dynamical spin susceptibility $\chi''(\mathbf{Q},E,T)$ is independent of
+temperature below a cut-off temperature $T_{\mathbf{Q}}$: the spin fluctuation
+amplitude saturates at low temperatures contrarily to its expected divergence
+at a quantum critical point. Above $T_{\mathbf{Q}}$, a $\mathbf{Q}$-dependent
+scaling behavior of the form $T\chi''(\mathbf{Q},E,T) =
+C_{\mathbf{Q}}f[E/(a_{\mathbf{Q}}T^{\beta_{\mathbf{Q}}})]$ with
+$\beta_{\mathbf{Q}}<1$ is obtained. This scaling does not enter the general
+framework of quantum phase transition theories, since it is obtained in a high
+temperature range, where Kondo spin fluctuations depend strongly on
+temperature.",0404124v2
+2004-07-20,Synthesis of Colloidal Mn2+:ZnO Quantum Dots and High-TC Ferromagnetic Nanocrystalline Thin Films,"We report the synthesis of colloidal Mn2+-doped ZnO (Mn2+:ZnO) quantum dots
+and the preparation of room-temperature ferromagnetic nanocrystalline thin
+films. Mn2+:ZnO nanocrystals were prepared by a hydrolysis and condensation
+reaction in DMSO under atmospheric conditions. Synthesis was monitored by
+electronic absorption and electron paramagnetic resonance (EPR) spectroscopies.
+Zn(OAc)2 was found to strongly inhibit oxidation of Mn2+ by O2, allowing the
+synthesis of Mn2+:ZnO to be performed aerobically. Mn2+ ions were removed from
+the surfaces of as-prepared nanocrystals using dodecylamine to yield
+high-quality internally doped Mn2+:ZnO colloids of nearly spherical shape and
+uniform diameter (6.1 +/- 0.7 nm). Simulations of the highly resolved X- and
+Q-band nanocrystal EPR spectra, combined with quantitative analysis of magnetic
+susceptibilities, confirmed that the manganese is substitutionally incorporated
+into the ZnO nanocrystals as Mn2+ with very homogeneous speciation, differing
+from bulk Mn2+:ZnO only in the magnitude of D-strain. Robust ferromagnetism was
+observed in spin-coated thin films of the nanocrystals, with 300 K saturation
+moments as large as 1.35 Bohr magneton/Mn2+ and TC > 350 K. A distinct
+ferromagnetic resonance signal was observed in the EPR spectra of the
+ferromagnetic films. The occurrence of ferromagnetism in Mn2+:ZnO and its
+dependence on synthetic variables are discussed in the context of these and
+previous theoretical and experimental results.",0407500v1
+2004-11-16,Upper Critical Fields up to 60T in Dirty Magnesium Diboride Thin Films,"Upper critical fields of several magnesium diboride thin films were measured
+up to 28 T at the Grenoble High Magnetic Field Laboratory (GHMFL) in Grenoble
+and up to 60 T at the Laboratoire National des Champs Magnetiques Pulses
+(LNCMP) in Toulouse. The samples were prepared both by pulsed laser deposition
+(PLD) and hybrid physical chemical vapour deposition (HPCVD) technique; they
+have critical temperatures between 29 and 39 K and normal state resistivities
+between 5 and 250 &#956;ohmcm; one of them has been intentionally doped with
+carbon. The measured critical fields were exceptionally high; we obtained the
+record value of 52 T at 4.2 K in the parallel orientation. In contrast with the
+BCS predictions, no saturation in Hc2 at low temperature was observed.
+Furthermore, films with a wide range of resistivity values showed similar
+critical fields, suggesting that in a two band system resistivity and Hc2 are
+not trivially linked. The high Hc2 values seem to be related with the expanded
+c-axis. The structure of one of the samples was carefully investigated with
+X-ray diffraction at European Synchrotron Radiation Facility (ESRF) in
+Grenoble.",0411404v1
+2005-01-12,Current induced magnetization switching in exchange biased spin-valves for CPP-GMR heads,"In contrast to earlier studies performed on simple Co/Cu/Co sandwiches, we
+have investigated spin transfer effects in complex spin-valve pillars with a
+diameter of 130nm developed for current-perpendicular to the plane (CPP)
+magneto-resistive heads. The structure of the samples included an exchange
+biased synthetic pinned layer and a free layer both laminated by insertion of
+several ultrathin Cu layers. Despite the small thickness of the polarizing
+layer, our results show that the free layer can be switched between the
+parallel (P) and the antiparallel (AP) states by applying current densities of
+the order of 10^7 A/cm^2. A strong asymmetry is observed between the two
+critical currents IcAP-P and IcP-AP, as predicted by the model of Slonczewski
+model. Thanks to the use of exchange biased structures, the stability phase
+diagrams could be obtained in the four quadrants of the (H, I) plan. The
+critical lines derived from the magnetoresistance curves measured with
+different sense currents, and from the resistance versus current curves
+measured for different applied fields, match each other very well. The main
+features of the phase diagrams can be reproduced by investigating the stability
+of the solutions of the Landau Lifshitz Gilbert equation including spin torque
+term within a macrospin model. A spin-transfer saturation effect was observed
+in the positive currents range. We attribute it to a de-depolarization effect
+which appears as a consequence of the asymmetric heating of the pillars, whose
+top and the bottom leads are made of different materials.",0501281v1
+2005-05-09,"Prospects of high temperature ferromagnetism in (Ga,Mn)As semiconductors","We report on a comprehensive combined experimental and theoretical study of
+Curie temperature trends in (Ga,Mn)As ferromagnetic semiconductors. Broad
+agreement between theoretical expectations and measured data allows us to
+conclude that T_c in high-quality metallic samples increases linearly with the
+number of uncompensated local moments on Mn_Ga acceptors, with no sign of
+saturation. Room temperature ferromagnetism is expected for a 10% concentration
+of these local moments. Our magnetotransport and magnetization data are
+consistnent with the picture in which Mn impurities incorporated during growth
+at interstitial Mn_I positions act as double-donors and compensate neighboring
+Mn_Ga local moments because of strong near-neighbor Mn_Ga-Mn_I
+antiferromagnetic coupling. These defects can be efficiently removed by
+post-growth annealing. Our analysis suggests that there is no fundamental
+obstacle to substitutional Mn_Ga doping in high-quality materials beyond our
+current maximum level of 6.2%, although this achievement will require further
+advances in growth condition control. Modest charge compensation does not limit
+the maximum Curie temperature possible in ferromagnetic semiconductors based on
+(Ga,Mn)As.",0505215v1
+2006-08-30,Spin-quadrupole ordering of spin-3/2 ultracold fermionic atoms in optical lattices in the one-band Hubbard model,"Based on a generalized one-band Hubbard model, we study magnetic properties
+of Mott insulating states for ultracold spin-3/2 fermionic atoms in optical
+lattices. When the \textit{s}-wave scattering lengths for the total spin
+$S=2,0$ satisfy conditions $a_{2}>a_{0}>0$, we apply a functional integral
+approach to the half filled case, where the spin-quadrupole fluctuations
+dominate. On a 2D square lattice, the saddle point solution yields a staggered
+spin-quadrupole ordering at zero temperature with symmetry breaking from SO(5)
+to SO(4). Both spin and spin-quadrupole static structure factors are
+calculated, displaying highly anisotropic spin antiferromagnetic fluctuations
+and antiferroquadrupole long-range correlations, respectively. When Gaussian
+fluctuations around the saddle point are taken into account, spin-quadrupole
+density waves with a linear dispersion are derived. Compared with the spin
+density waves in the half filled spin-1/2 Hubbard model, the quadrupole density
+wave velocity is saturated in the strong-coupling limit, and there are no
+transverse spin-quadrupole mode couplings, as required by the SO(4) invariance
+of the effective action. Finally, in the strong-coupling limit of the model
+Hamiltonian, we derive the effective hyperfine spin-exchange interactions for
+the Mott insulating phases in the quarter filled and half filled cases,
+respectively.",0608673v3
+2006-04-04,Deconfinement in dense 2-color QCD,"We study SU(2) lattice gauge theory with two flavors of Wilson fermion at
+non-zero chemical potential mu and low temperature on a 8^3x16 system. We
+identify three regimes along the mu-axis. For mu<~m_pi/2 the system remains in
+the vacuum phase, and all physical observables considered remain essentially
+unchanged. The intermediate regime is characterised by a non-zero diquark
+condensate and an associated increase in the baryon density, consistent with
+what is expected for Bose-Einstein condensation of tightly bound diquarks. We
+also observe screening of the static quark potential here. In the high-density
+deconfined regime we find a non-zero Polyakov loop and a strong modification of
+the gluon propagator, including significant screening in the magnetic sector in
+the static limit, which must have a non-perturbative origin. The behaviour of
+thermodynamic observables and the superfluid order parameter are consistent
+with a Fermi surface disrupted by a BCS diquark condensate. The energy per
+baryon as a function of mu exhibits a minimum in the deconfined regime,
+implying that macroscopic objects such as stars formed in this theory are
+largely composed of quark matter.",0604004v2
+1995-07-09,"Long Distance Contribution to $s \to dγ$ and Implications for $Ω^-\to Ξ^-γ, B_s \to B_d^*γ$ and $b \to sγ$","We estimate the long distance (LD) contribution to the magnetic part of the
+$s \to d\gamma$ transition using the Vector Meson Dominance approximation
+$(V=\rho,\omega,\psi_i)$. We find that this contribution may be significantly
+larger than the short distance (SD) contribution to $s \to d\gamma$ and could
+possibly saturate the present experimental upper bound on the $\Omega^-\to
+\Xi^-\gamma$ decay rate, $\Gamma^{\rm MAX}_{\Omega^-\to \Xi^-\gamma} \simeq
+3.7\times10^{-9}$eV. For the decay $B_s \to B^*_d\gamma$, which is driven by $s
+\to d\gamma$ as well, we obtain an upper bound on the branching ratio $BR(B_s
+\to B_d^*\gamma)<3\times10^{-8}$ from $\Gamma^{\rm MAX}_{\Omega^-\to
+\Xi^-\gamma}$. Barring the possibility that the Quantum Chromodynamics
+coefficient $a_2(m_s)$ be much smaller than 1, $\Gamma^{\rm MAX}_{\Omega^-\to
+\Xi^-\gamma}$ also implies the approximate relation $\frac{2}{3} \sum_i
+\frac{g^2_{\psi_i}(0)}{m^2_{\psi_i}} \simeq \frac{1}{2}
+\frac{g^2_\rho(0)}{m^2_\rho} + \frac{1}{6}\frac{g^2_\omega(0)}{m^2_\omega}$.
+This relation agrees quantitatively with a recent independent estimate of the
+l.h.s. by Deshpande et al., confirming that the LD contributions to $b \to
+s\gamma$ are small. We find that these amount to an increase of $(4\pm2)\%$ in
+the magnitude of the $b \to s \gamma$ transition amplitude, relative to the SD
+contribution alone.",9507267v1
+1992-05-13,Supersymmetry as a Cosmic Censor,"In supersymmetric theories the mass of any state is bounded below by the
+values of some of its charges. The corresponding bounds in case of
+Schwarzschild and Reissner-Nordstr\""om black holes are known to coincide with
+the requirement that naked singularities be absent. Here we investigate charged
+dilaton black holes in this context. We show that the extreme solutions
+saturate the supersymmetry bound of $N=4\ d=4$ supergravity, or dimensionally
+reduced superstring theory. Specifically, we have shown that extreme dilaton
+black holes, with electric and magnetic charges, admit super-covariantly
+constant spinors. The supersymmetric positivity bound for dilaton black holes,
+$M \geq \frac{1}{\sqrt 2}(|Q|+|P|)$, takes care of the absence of naked
+singularities of the dilaton black holes and is, in this sense, equivalent to
+the cosmic censorship condition. The temperature, entropy and singularity are
+discussed. The Euclidean action (entropy) of the extreme black hole is given by
+$2\pi |PQ|$. We argue that this result, as well as the one for Lorentzian
+signature, is not altered by higher order corrections in the supersymmetric
+theory. When a black hole reaches its extreme limit, it cannot continue to
+evaporate by emitting elementary particles, since this would violate the
+supersymmetric positivity bound. We speculate on the possibility that an
+extreme black hole may ``evaporate"" by emitting smaller extreme black holes.",9205027v1
+2003-12-01,D-term strings,"We study the embedding of cosmic strings, related to the
+Abrikosov-Nielsen-Olesen vortex solution, into d=4, N=1 supergravity. We find
+that the local cosmic string solution which saturates the BPS bound of
+supergravity with $D$-term potential for the Higgs field and with constant
+Fayet--Iliopoulos term, has 1/2 of supersymmetry unbroken. We observe an
+interesting relation between the gravitino supersymmetry transformation,
+positive energy condition and the deficit angle of the cosmic string. We argue
+that the string solutions with magnetic flux with F-term potential cannot be
+supersymmetric, which leads us to a conjecture that D1-strings (wrapped
+D(1+q)-branes) of string theory in the effective 4d supergravity are described
+by the D-term strings that we study in this paper. We give various consistency
+checks of this conjecture, and show that it highlights some generic properties
+of non-BPS string theory backgrounds, such as brane-anti-brane systems.
+Supersymmetry breaking by such systems can be viewed as FI D-term breaking,
+which implies, under certain conditions, the presence of gauged R-symmetry on
+such backgrounds. The D-term nature of the brane-anti-brane energy can also
+provide information on the superpotential for the tachyon, which Higgses the
+R-symmetry. In this picture, the inter-brane force can be viewed as a result of
+the world-volume gauge coupling renormalization by the open string loops.",0312005v3
+2000-03-23,Enhanced dielectronic recombination of lithium-like Ti19+ ions in external ExB fields,"Dielectronic recombination(DR) of lithium-like Ti19+(1s2 2s) ions via 2s->2p
+core excitations has been measured at the Heidelberg heavy ion storage ring
+TSR. We find that not only external electric fields (0 <= Ey <= 280 V/cm) but
+also crossed magnetic fields (30 mT <= Bz <= 80 mT) influence the DR via high-n
+(2p_j nl)-Rydberg resonances. This result confirms our previous finding for
+isoelectronic Cl14+ ions [Bartsch T et al, PRL 82, 3779 (1999)] that
+experimentally established the sensitivity of DR to ExB fields. In the present
+investigation the larger 2p_{1/2}-2p_{3/2} fine structure splitting of Ti19+
+allowed us to study separately the influence of external fields via the two
+series of Rydberg DR resonances attached to the 2s -> 2p_{1/2} and 2s ->
+2p_{3/2} excitations of the Li-like core, extracting initial slopes and
+saturation fields of the enhancement. We find that for Ey > 80 V/cm the field
+induced enhancement is about 1.8 times stronger for the 2p_{3/2} series than
+for the 2p_{1/2} series.",0003055v2
+2003-12-11,"Start-to-End Simulations of SASE FEL at the TESLA Test Facility, Phase 1","Phase 1 of the vacuum ultra-violet (VUV) free-electron laser (FEL) at the
+TESLA Test Facility (TTF) recently concluded operation. It successfully
+demonstrated the saturation of a SASE FEL in the in the wavelength range of
+80-120 nm. We present a posteriori start-to-end numerical simulations of this
+FEL. These simulations are based on the programs Astra and elegant for the
+generation and transport of the electron distribution. An independent
+simulation of the intricate beam dynamics in the magnetic bunch compressor is
+performed with the program CSRtrack. The SASE FEL process is simulated with the
+code FAST. From our detailed simulations and the resulting phase space
+distribution at the undulator entrance, we found that the FEL was driven only
+by a small fraction (slice) of the electron bunch. This ""lasing slice"" is
+located in the head of the bunch, and has a peak current of approximately 3 kA.
+A strong energy chirp (due to the space charge field after compression) within
+this slice had a significant influence on the FEL operation. Our study shows
+that the radiation pulse duration is about 40 fs (FWHM) with a corresponding
+peak power of 1.5 GW. The simulated FEL properties are compared with various
+experimental data and found to be in excellent agreement.",0312074v1
+2007-07-16,Blue laser cooling transitions in Tm I,"We have studied possible candidates for laser cooling transitions in
+$^{169}$Tm in the spectral region 410 -- 420 nm. By means of saturation
+absorption spectroscopy we have measured the hyperfine structure and rates of
+two nearly closed cycling transitions from the ground state
+$4\textrm{f}^{13}6\textrm{s}^2(^2\textrm{F}_0)(J_g=7/2)$ to upper states
+$4\textrm{f}^{12}(^3\textrm{H}_5)5\textrm{d}_{3/2}6\textrm{s}^2(J_e=9/2)$ at
+410.6 nm and
+$4\textrm{f}^{12}(^3\textrm{F}_4)5\textrm{d}_{5/2}6\textrm{s}^2(J_e=9/2)$ at
+420.4 nm and evaluated the life times of the excited levels as 15.9(8) ns and
+48(6) ns respectively. Decay rates from these levels to neighboring
+opposite-parity levels are evaluated by means of Hartree-Fock calculations. We
+conclude, that the strong transition at 410.6 nm has an optical leak rate of
+less then $2\cdot10^{-5}$ and can be used for efficient laser cooling of
+$^{169}$Tm from a thermal atomic beam. The hyperfine structure of two other
+even-parity levels which can be excited from the ground state at 409.5 nm and
+418.9 nm is also measured by the same technique. In addition we give a
+calculated value of $7(2)$ s$^{-1}$ for the rate of magnetic-dipole transition
+at 1.14 $\mu$m between the fine structure levels
+$(J_g=7/2)\leftrightarrow(J'_g=5/2)$ of the ground state which can be
+considered as a candidate for applications in atomic clocks.",0707.2280v2
+2007-10-01,Highly Efficient Modeling of Dynamic Coronal Loops,"Observational and theoretical evidence suggests that coronal heating is
+impulsive and occurs on very small cross-field spatial scales. A single coronal
+loop could contain a hundred or more individual strands that are heated
+quasi-independently by nanoflares. It is therefore an enormous undertaking to
+model an entire active region or the global corona. Three-dimensional MHD codes
+have inadequate spatial resolution, and 1D hydro codes are too slow to simulate
+the many thousands of elemental strands that must be treated in a reasonable
+representation. Fortunately, thermal conduction and flows tend to smooth out
+plasma gradients along the magnetic field, so ""0D models"" are an acceptable
+alternative. We have developed a highly efficient model called Enthalpy-Based
+Thermal Evolution of Loops (EBTEL) that accurately describes the evolution of
+the average temperature, pressure, and density along a coronal strand. It
+improves significantly upon earlier models of this type--in accuracy,
+flexibility, and capability. It treats both slowly varying and highly impulsive
+coronal heating; it provides the differential emission measure distribution,
+DEM(T), at the transition region footpoints; and there are options for heat
+flux saturation and nonthermal electron beam heating. EBTEL gives excellent
+agreement with far more sophisticated 1D hydro simulations despite using four
+orders of magnitude less computing time. It promises to be a powerful new tool
+for solar and stellar studies.",0710.0185v2
+2007-12-07,Locality and low-dimensions in the prediction of natural experience from fMRI,"Functional Magnetic Resonance Imaging (fMRI) provides dynamical access into
+the complex functioning of the human brain, detailing the hemodynamic activity
+of thousands of voxels during hundreds of sequential time points. One approach
+towards illuminating the connection between fMRI and cognitive function is
+through decoding; how do the time series of voxel activities combine to provide
+information about internal and external experience? Here we seek models of fMRI
+decoding which are balanced between the simplicity of their interpretation and
+the effectiveness of their prediction. We use signals from a subject immersed
+in virtual reality to compare global and local methods of prediction applying
+both linear and nonlinear techniques of dimensionality reduction. We find that
+the prediction of complex stimuli is remarkably low-dimensional, saturating
+with less than 100 features. In particular, we build effective models based on
+the decorrelated components of cognitive activity in the classically-defined
+Brodmann areas. For some of the stimuli, the top predictive areas were
+surprisingly transparent, including Wernicke's area for verbal instructions,
+visual cortex for facial and body features, and visual-temporal regions for
+velocity. Direct sensory experience resulted in the most robust predictions,
+with the highest correlation ($c \sim 0.8$) between the predicted and
+experienced time series of verbal instructions. Techniques based on non-linear
+dimensionality reduction (Laplacian eigenmaps) performed similarly. The
+interpretability and relative simplicity of our approach provides a conceptual
+basis upon which to build more sophisticated techniques for fMRI decoding and
+offers a window into cognitive function during dynamic, natural experience.",0712.1219v2
+2008-04-29,Phase Diagram and Entanglement of Ising Model With Dzyaloshinskii-Moriya Interaction,"We have studied the phase diagram and entanglement of the one dimensional
+Ising model with Dzyaloshinskii-Moriya (DM) interaction. We have applied the
+quantum renormalization group (QRG) approach to get the stable fixed points,
+critical point and the scaling of coupling constants. This model has two
+phases, antiferromagnetic and saturated chiral ones. We have shown that the
+staggered magnetization is the order parameter of the system and DM interaction
+produces the chiral order in both phases. We have also implemented the exact
+diagonalization (Lanczos) method to calculate the static structure factors. The
+divergence of structure factor at the ordering momentum as the size of systems
+goes to infinity defines the critical point of the model. Moreover, we have
+analyzed the relevance of the entanglement in the model which allows us to shed
+insight on how the critical point is touched as the size of the system becomes
+large. Nonanalytic behavior of entanglement and finite size scaling have been
+analyzed which is tightly connected to the critical properties of the model. It
+is also suggested that a spin-fluid phase has a chiral order in terms of new
+spin operators which are defined by a nonlocal transformation.",0804.4579v3
+2008-06-05,The sawtooth chain: From Heisenberg spins to Hubbard electrons,"We report on recent studies of the spin-half Heisenberg and the Hubbard model
+on the sawtooth chain. For both models we construct a class of exact
+eigenstates which are localized due to the frustrating geometry of the lattice
+for a certain relation of the exchange (hopping) integrals. Although these
+eigenstates differ in details for the two models because of the different
+statistics, they share some characteristic features. The localized eigenstates
+are highly degenerate and become ground states in high magnetic fields
+(Heisenberg model) or at certain electron fillings (Hubbard model),
+respectively. They may dominate the low-temperature thermodynamics and lead to
+an extra low-temperature maximum in the specific heat. The ground-state
+degeneracy can be calculated exactly by a mapping of the manifold of localized
+ground states onto a classical hard-dimer problem, and explicit expressions for
+thermodynamic quantities can be derived which are valid at low temperatures
+near the saturation field for the Heisenberg model or around a certain value of
+the chemical potential for the Hubbard model, respectively.",0806.0922v2
+2008-06-28,Spin-dependent scattering in a silicon transistor,"The scattering of conduction electrons off neutral donors depends sensitively
+on the relative orientation of their spin states. We present a theory of
+spin-dependent scattering in the two dimensional electron gas (2DEG) of field
+effect transistors. Our theory shows that the scattering mechanism is dominated
+by virtual transitions to negatively ionized donor levels. This effect
+translates into a source-drain current that always gets reduced when donor
+spins are at resonance with a strong microwave field. We propose a model for
+donor impurities interacting with conduction electrons in a silicon transistor,
+and compare our explicit numerical calculations to electrically detected
+magnetic resonance (EDMR) experiments. Remarkably, we show that EDMR is optimal
+for donors placed into a sweet spot located at a narrow depth window quite far
+from the 2DEG interface. This allows significant optimization of spin signal
+intensity for the minimal number of donors placed into the sweet spot, enabling
+the development of single spin readout devices. Our theory reveals an
+interesting dependence on conduction electron spin polarization p_c. As p_c
+increases upon spin injection, the EDMR amplitude first increases as p_{c}^{2},
+and then saturates when a polarization threshold p_T is reached. These results
+show that it is possible to use EDMR as an in-situ probe of carrier spin
+polarization in silicon and other materials with weak spin-orbit coupling.",0806.4638v3
+2008-09-23,Dissipation and Heating in Supersonic Hydrodynamic and MHD Turbulence,"We study energy dissipation and heating by supersonic MHD turbulence in
+molecular clouds using Athena, a new higher-order Godunov code. We analyze the
+dependence of the saturation amplitude, energy dissipation characteristics,
+power spectra, sonic scaling, and indicators of intermittency in the turbulence
+on factors such as the magnetic field strength, driving scale, energy injection
+rate, and numerical resolution. While convergence in the energies is reached at
+moderate resolutions, we find that the power spectra require much higher
+resolutions that are difficult to obtain. In a 1024^3 hydro run, we find a
+power law relationship between the velocity dispersion and the spatial scale on
+which it is measured, while for an MHD run at the same resolution we find no
+such power law. The time-variability and temperature intermittency in the
+turbulence both show a dependence on the driving scale, indicating that
+numerically driving turbulence by an arbitrary mechanism may not allow a
+realistic representation of these properties. We also note similar features in
+the power spectrum of the compressive component of velocity for supersonic MHD
+turbulence as in the velocity spectrum of an initially-spherical MHD blast
+wave, implying that the power law form does not rule out shocks, rather than a
+turbulent cascade, playing a significant role in the regulation of energy
+transfer between spatial scales.",0809.4005v1
+2008-09-24,Discovery of X-ray emission from the eclipsing brown-dwarf binary 2MASS J05352184-0546085,"The eclipsing brown-dwarf binary system 2MASS J05352184-0546085 is a case sui
+generis. For the first time, it allows a detailed analysis of the individual
+properties of young brown dwarfs, in particular, masses, and radii, and the
+temperature ratio of the system components can be determined accurately. The
+system shows a ""temperature reversal"" with the more massive component being the
+cooler one, and both components are found to be active. We analyze X-ray images
+obtained by Chandra and XMM-Newton containing 2MASS J05352184-0546085 in their
+respective field of view. The Chandra observatory data show a clear X-ray
+source at the position of 2MASS J05352184-0546085, whereas the XMM-Newton data
+suffer from contamination from other nearby sources, but are consistent with
+the Chandra detection. No indications of flaring activity are found in either
+of the observations (together about 70 ks), and we thus attribute the observed
+flux to quiescent emission. With an X-ray luminosity of 3*10^{28} erg/s we find
+an L_X/L_{bol}-ratio close to the saturation limit of 10^{-3} and an
+L_{X}/L_{H\alpha}-ratio consistent with values obtained from low-mass stars.
+The X-ray detection of 2MASS J05352184-0546085 reported here provides
+additional support for the interpretation of the temperature reversal in terms
+of magnetically suppressed convection, and suggests that the activity phenomena
+of young brown dwarfs resemble those of their more massive counterparts.",0809.4129v1
+2008-11-14,Reduction of the field-dependent microwave surface resistance in YBa_2Cu_3O_7 with sub-micrometric BaZrO_3 inclusions as a function of BaZrO_3 concentration,"In order to study the vortex pinning determined by artificially introduced
+pinning centers in the small-vortex displacement regime, we measured the
+microwave surface impedance at 47.7 GHz in the mixed state of
+YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ thin films, where sub-micrometric BaZrO$_3$
+particles have been incorporated. As a function of the BaZrO$_3$ content, we
+observe that the absolute losses slightly decrease up to a BaZrO$_3$ content of
+5%, and then increase. We found that the magnetic-field-induced losses behave
+differently, in that they are not monotonic with increasing BaZrO$_3$
+concentration: at small concentration (2.5%) the field-induced losses increase,
+but large reduction of the losses themselves, by factors up to 3, is observed
+upon further increasing the BaZrO$_3$ concentration in the target up to 7%.
+Using measurements of both surface resistance and surface reactance we estimate
+vortex pinning-related parameters. We find that BaZrO$_3$ inclusions introduce
+deep and steep pinning wells. In particular, the minimum height of the energy
+barrier for single vortices is raised. At larger BaZrO$_3$ content (5% and 7%)
+the phenomenon is at its maximum, but it is unclear whether it shows a
+saturation or not, thus leaving room for further improvements.",0811.2351v1
+2008-12-26,Flux quanta driven by high-density currents in low-impurity V3Si and LuNi2B2C: free flux flow and flux-core size effect,"High density direct currents (DC) are used to drive flux quanta via the
+Lorentz force towards a highly ordered ""free flux flow"" (FFF) dynamic state,
+made possible by the weak-pinning environment of high-quality, single-crystal
+samples of two low-Tc superconducting compounds, V3Si and LuNi2B2C. We report
+the effect of the magnetic field-dependent fluxon core size on flux flow
+resistivity rho_f. Much progress has been made in minimizing the technical
+challenges associated with the use of high currents. Attainment of a FFF phase
+is indicated by the saturation at highest currents of flux-flow dissipation
+levels that are well below the normal state resistance and have field-dependent
+values. The field dependence of the corresponding rho_f is shown to be
+consistent with a prediction based on a model for the decrease of flux core
+size at higher fields in weak-coupling BCS s-wave materials.",0812.4715v4
+2009-02-11,Non-exponential London penetration depth in Ba$_{1-}$K$_{x}$Fe$_{2}$As$_{2}$ single crystals,"We have studied the in- and out-of-plane magnetic penetration depths in the
+hole- doped iron based superconductor Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$
+($T_{c}\approx$ 30K). The study was performed on single crystals grown from
+different fluxes and we find that the results are nearly the same. The in-plane
+London penetration depth $\lambda_{ab}$ does not show exponential saturation at
+low temperature, as would be expected from a fully gapped superconductor.
+Instead, $\lambda_{ab}(T)$ shows a power-law behavior, $\lambda\propto T^{n}$
+($n\approx 2$), down to $T\approx 0.02 T_{c}$, similar to the electron doped
+Ba(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$. The penetration depth anisotropy
+$\gamma_{\lambda}=\lambda_{c}(T)/\lambda_{ab}(T)$ increases upon cooling,
+opposite to the trend observed in the anisotropy of the upper critical field,
+$\gamma_{\xi}=H_{c2}^{\perp c}(0)/H_{c2}^{\parallel c}(0)$. These are universal
+characteristics of both the electron and hole doped 122 systems, suggesting
+unconventional superconductivity. The behavior of the in-plane superfluid
+density $\rho_{ab}(T)$ is discussed in light of existing theoretical models
+proposed for the iron pnictides superconductors.",0902.1804v1
+2009-02-12,"Manganite charge and orbitally ordered and disordered states probed by Fe substitution into Mn site in LnBaMn1.96Fe0.04O5, LnBaMn1.96Fe0.04O6 and LnBaMn1.96Fe0.04O5.5 (Ln=Y, Gd, Sm, Nd, Pr, La)","The layered manganese oxides LnBaMn1.96Fe0.04Oy (Ln=Y, Gd, Sm, Nd, Pr, La)
+have been synthesized for y=5, 5.5 and 6. In the oxygen-saturated state (y=6)
+they exhibit the charge and orbital order at ambient temperature for Ln=Y, Gd,
+Sm, but unordered eg-electronic system for Ln=La,Pr,Nd. Fourfold increase of
+quadrupole splitting was observed owing to the charge and orbital ordering.
+This is in agreement with the jumplike increase in distortion of the reduced
+perovskite-like cell for the charge and orbitally ordered manganites compared
+to the unordered ones. Substitution of 2 percents of Mn by Fe suppresses the
+temperatures of structural and magnetic transitions by 20 to 50 K. Parameters
+of the crystal lattices and the room-temperature M\""{o}ssbauer spectra were
+studied on forty samples whose structures were refined within five symmetry
+groups: P4/mmm, P4/nmm, Pm-3m, Icma and P2/m. Overwhelming majority of the Fe
+species are undifferentiated in the M\""{o}ssbauer spectra for most of the
+samples. Such the single-component spectra in the two-site structures are
+explained by the preference of Fe towards the site of Mn(III) and by the
+segmentation of the charge and orbitally ordered domains.",0902.2027v2
+2009-02-15,Sudden Critical Current Drops Induced in S/F Structures,"In the search for new physical properties of S/F structures, we have found
+that the superconductor critical current can be controlled by the domain state
+of the neighboring ferromagnet. The superconductor is a thin wire of thickness
+d_{s} ~ 2 xi_{S}. Nb/Co and Nb/Py (Permalloy Ni_{80}Fe_{20}) bilayer structures
+were grown with a significant magnetic anisotropy. Critical current
+measurements of Nb/Co structures with ferromagnet thickness d_{F} > 30nm show
+sudden drops in two very defined steps when the measurements are made along the
+hard axes direction (i.e. current track parallel to hard anisotropy axes
+direction). These drops disappear when they are made along the easy axis
+direction or when the ferromagnet thickness is below 30nm. The drops are
+accompanied by vortex flux flow. In addition magnetorestistance measurements
+close to Tc show a sharp increase near saturation fields of the ferromagnet.
+Similar results are reproduced in Nb/Py bilayer structure with the ferromagnet
+thickness d_{F} ~ 50nm along the easy anisotropy axes. These results are
+explained as being due to spontaneous vortex formation and flow induced by
+Bloch domain walls of the ferromagnet underneath. We argue these Bloch domain
+walls produce a 2D vortex-antivortex lattice structure.",0902.2572v2
+2009-08-17,Criticality in the randomness-induced second-order phase transition of the triangular Ising antiferromagnet with nearest- and next-nearest-neighbor interactions,"Using a Wang-Landau entropic sampling scheme, we investigate the effects of
+quenched bond randomness on a particular case of a triangular Ising model with
+nearest- ($J_{nn}$) and next-nearest-neighbor ($J_{nnn}$) antiferromagnetic
+interactions. We consider the case $R=J_{nnn}/J_{nn}=1$, for which the pure
+model is known to have a columnar ground state where rows of nearest-neighbor
+spins up and down alternate and undergoes a weak first-order phase transition
+from the ordered to the paramagnetic state. With the introduction of quenched
+bond randomness we observe the effects signaling the expected conversion of the
+first-order phase transition to a second-order phase transition and using the
+Lee-Kosterlitz method, we quantitatively verify this conversion. The emerging,
+under random bonds, continuous transition shows a strongly saturating specific
+heat behavior, corresponding to a negative exponent $\alpha$, and belongs to a
+new distinctive universality class with $\nu=1.135(11)$, $\gamma/\nu=1.744(9)$,
+and $\beta/\nu=0.124(8)$. Thus, our results for the critical exponents support
+an extensive but weak universality and the emerged continuous transition has
+the same magnetic critical exponent (but a different thermal critical exponent)
+as a wide variety of two-dimensional (2d) systems without and with quenched
+disorder.",0908.2298v1
+2009-09-15,Quantum machine using cold atoms,"For a machine to be useful in practice, it preferably has to meet two
+requirements: namely, (i) to be able to perform work under a load and (ii) its
+operational regime should ideally not depend on the time at which the machine
+is switched-on. We devise a minimal setup, consisting of two atoms only, for an
+ac-driven quantum motor which fulfills both these conditions. Explicitly, the
+motor consists of two different interacting atoms placed into a ring-shaped
+periodic optical potential -- an optical ""bracelet"" --, resulting from the
+interference of two counter-propagating Laguerre-Gauss laser beams. This
+bracelet is additionally threaded by a pulsating magnetic flux. While the first
+atom plays a role of a quantum ""carrier"", the second serves as a quantum
+""starter"", which sets off the ""carrier"" into a steady rotational motion. For
+fixed zero-momentum initial conditions the asymptotic carrier velocity
+saturates to a unique, nonzero value which becomes increasingly independent on
+the starting time with increasing ""bracelet""-size. We identify the quantum
+mechanisms of rectification and demonstrate that our quantum motor is able to
+perform useful work.",0909.2813v2
+2009-11-12,Comparisons and Connections between Mean Field Dynamo Theory and Accretion Disc Theory,"The origin of large scale magnetic fields in astrophysical rotators, and the
+conversion of gravitational energy into radiation near stars and compact
+objects via accretion have been subjects of active research for a half century.
+Magnetohydrodynamic turbulence makes both problems highly nonlinear, so both
+subjects have benefitted from numerical simulations.However, understanding the
+key principles and practical modeling of observations warrants testable
+semi-analytic mean field theories that distill the essential physics. Mean
+field dynamo (MFD) theory and alpha-viscosity accretion disc theory exemplify
+this pursuit. That the latter is a mean field theory is not always made
+explicit but the combination of turbulence and global symmetry imply such. The
+more commonly explicit presentation of assumptions in 20th century textbook
+MFDT has exposed it to arguably more widespread criticism than incurred by 20th
+century alpha-accretion theory despite complementary weaknesses. In the 21st
+century however, MFDT has experienced a breakthrough with a dynamical
+saturation theory that consistently agrees with simulations. Such has not yet
+occurred in accretion disc theory, though progress is emerging. Ironically
+however, for accretion engines, MFDT and accretion theory are presently two
+artificially uncoupled pieces of what should be a single coupled theory. Large
+scale fields and accretion flows are dynamically intertwined because large
+scale fields likely play a key role in angular momentum transport. I discuss
+and synthesize aspects of recent progress in MFDT and accretion disc theory to
+suggest why the two likely conspire in a unified theory.",0911.2315v2
+2010-05-11,Spin susceptibility of interacting two-dimensional electrons in the presence of spin-orbit coupling,"A long-range interaction via virtual particle-hole pairs between Fermi-liquid
+quasiparticles leads to a nonanalytic behavior of the spin susceptibility
+$\chi$ as a function of the temperature ($T$), magnetic field ($\mathbf{B}$),
+and wavenumber. In this paper, we study the effect of the Rashba spin-orbit
+interaction (SOI) on the nonanalytic behavior of $\chi$ for a two-dimensional
+electron liquid. Although the SOI breaks the SU(2) symmetry, it does not
+eliminate nonanalyticity but rather makes it anisotropic: while the linear
+scaling of $\chi_{zz}$ with $T$ and $|\mathbf{B}|$ saturates at the energy
+scale set by the SOI, that of $\chi_{xx}$ ($=\chi_{yy}$) continues through this
+energy scale, until renormalization of the electron-electron interaction in the
+Cooper channel becomes important. We show that the Renormalization Group flow
+in the Cooper channel has a non-trivial fixed point, and study the consequences
+of this fixed point for the nonanalytic behavior of $\chi$. An immediate
+consequence of SOI-induced anisotropy in the nonanalytic behavior of $\chi$ is
+a possible instability of a second-order ferromagnetic quantum phase transition
+with respect to a first-order transition to an XY ferromagnetic state.",1005.1913v2
+2011-02-13,The fratricide of alpha-Omega dynamos by their alpha-squared siblings,"Context. Helically forced magneto-hydrodynamic shearing-sheet turbulence can
+support different large-scale dynamo modes, although the {\alpha} - {\Omega}
+mode is generally expected to dominate because it is the fastest growing. In an
+{\alpha} - {\Omega} dynamo, most of the field amplification is produced by the
+shear. As differential rotation is an ubiquitous source of shear in
+astrophysics, such dynamos are believed to be the source of most astrophysical
+large-scale magnetic fields. Aims. We study the stability of oscillatory
+migratory {\alpha} - {\Omega} type dynamos in turbulence simulations. Methods.
+We use shearing-sheet simulations of hydromagnetic turbulence that is helically
+forced at a wavenumber that is about three times larger than the lowest
+wavenumber in the domain so that both {\alpha} - {\Omega} and {\alpha}2 dynamo
+action is possible. Results. After initial dominance and saturation, the
+{\alpha} - {\Omega} mode is found to be destroyed by an orthogonal {\alpha}2
+mode sustained by the helical turbulence alone. We show that there are at least
+two processes through which this transition can occur. Conclusions. The
+fratricide of {\alpha} - {\Omega} dynamos by its {\alpha}2 sibling is discussed
+in the context of grand minima of solar and stellar activity. However, the
+genesis of {\alpha} - {\Omega} dynamos from an {\alpha}2 dynamo has not yet
+been found.",1102.2617v1
+2011-03-23,Galactic centre star formation writ large in gamma-rays,"We have modelled the high-energy astrophysics of the inner 200 pc of the
+Galaxy with a view to explaining the diffuse, broad-band (radio continuum to
+TeV gamma-ray), non-thermal signal detected from this region. Our modelling
+pins down the ISM parameters for the environment wherein cosmic ray (CR)
+electrons and ions reside in the Galactic centre (GC). We find that the
+magnetic field in this region is 100-300 microG, the gas density < 60 cm^-3,
+and that a powerful (> 200 km/s) 'super'-wind acts to remove > 95% of the
+cosmic rays accelerated in the region before they have time to lose their
+energy in situ. The ~ 10^39 erg/s carried away by the GC cosmic ray protons is
+precisely enough to energise the ~GeV gamma-ray emission from the Fermi
+'bubbles' recently found to extend north and south of the GC out to distances
+of ~10 kpc, provided that the bubbles constitute thick targets to the GC
+protons and that the situation has reached steady state. In such a situation of
+'saturation' the hard, uniform spectrum of the bubbles are explained and
+secondary electron synchrotron explains the non-thermal microwave emission
+found in WMAP data mirroring the bubbles. Given the very low density of the
+bubble plasma (<0.01 cm^-3), the pp loss time in the Bubbles is > 5 Gyr. Our
+scenario thus has the startling implication that a GC source of nonthermal
+particles of time-averaged power 10^39 erg/s has persisted since the youth of
+the Galaxy.",1103.4523v2
+2012-01-12,Detection of accretion X-rays from QS Vir: cataclysmic or a lot of hot air?,"An XMM-Newton observation of the nearby ""pre-cataclysmic"" short-period (P_orb
+= 3.62 hr) binary QS Vir (EC 13471-1258) revealed regular narrow X-ray eclipses
+when the white dwarf passed behind its M2-4 dwarf companion. The X-ray emission
+provides a clear signature of mass transfer and accretion onto the white dwarf.
+The low-resolution XMM-Newton EPIC spectra are consistent with a cooling flow
+model and indicate an accretion rate of Mdot= 1.7\times10^-13M\odot/yr. At 48
+pc distant, QS Vir is then the second nearest accreting cataclysmic variable
+known, with one of the lowest accretion rates found to date for a non-magnetic
+system. To feed this accretion through a wind would require a wind mass loss
+rate of Mdot ~ 2 \times 10^-12M\odot/yr if the accretion efficiency is of the
+order of 10%. Consideration of likely mass loss rates for M dwarfs suggests
+this is improbably high and pure wind accretion unlikely. A lack of accretion
+disk signatures also presents some difficulties for direct Roche lobe overflow.
+We speculate that QS Vir is on the verge of Roche lobe overflow, and that the
+observed mass transfer could be supplemented by upward chromospheric flows on
+the M dwarf, analogous to spicules and mottles on the Sun, that escape the
+Roche surface to be subsequently swept up into the white dwarf Roche lobe. If
+so, QS Vir would be in a rare evolutionary phase lasting only a million years.
+The X-ray luminosity of the M dwarf estimated during primary eclipse is L_X = 3
+\times 10^28 erg/s, which is consistent with that of rapidly rotating
+""saturated"" K and M dwarfs.",1201.2682v1
+2012-01-14,Stabilization of the high-spin state of Co$^{3+}$ in LaCo$_{1-x}$Rh$_{x}$O$_3$,"The rhodium doping in the LaCo$_{1-x}$Rh$_{x}$O$_3$ perovskite series
+($x=0.02-0.5$) has been studied by X-ray diffraction, electric transport and
+magnetization measurements, complemented by electronic structure GGA+U
+calculations in supercell for different concentration regimes. No charge
+transfer between Co$^{3+}$ and Rh$^{3+}$ is evidenced. The diamagnetic ground
+state of LaCoO$_3$, based on Co$^{3+}$ in low-spin (LS) state, is disturbed
+even by a small doping of Rh. The driving force is the elastic energy connected
+with incorporation of a large Rh$^{3+}$ cation into the matrix of small LS
+Co$^{3+}$ cations, which is relaxed by formation of large Co$^{3+}$ in
+high-spin (HS) state in the next-nearest sites to the inserted Rh atom. With
+increasing temperature, the population of Co$^{3+}$ in HS state increases
+through thermal excitation, and a saturated phase is obtained close to room
+temperature, consisting of a nearest-neighbor correlation of small (LS
+Co$^{3+}$) and large (HS Co$^{3+}$ and LS Rh$^{3+}$) cations in a kind of
+double perovskite structure. The stabilizing role of elastic and electronic
+energy contributions is demonstrated in supercell calculations for dilute Rh
+concentration compared to other dopants with various trivalent ionic radius.",1201.3050v1
+2012-02-15,The HBI in a quasi-global model of the intracluster medium,"In this paper we investigate how convective instabilities influence heat
+conduction in the intracluster medium (ICM) of cool-core galaxy clusters. The
+ICM is a high-beta, weakly collisional plasma in which the transport of
+momentum and heat is aligned with the magnetic field. The anisotropy of heat
+conduction, in particular, gives rise to instabilities that can access energy
+stored in a temperature gradient of either sign. We focus on the heat-flux
+buoyancy-driven instability (HBI), which feeds on the outwardly increasing
+temperature profile of cluster cool cores. Our aim is to elucidate how the
+global structure of a cluster impacts on the growth and morphology of the
+linear HBI modes when in the presence of Braginskii viscosity, and ultimately
+on the ability of the HBI to thermally insulate cores. We employ an idealised
+quasi-global model, the plane-parallel atmosphere, which captures the essential
+physics -- e.g. the global radial profile of the cluster -- while letting the
+problem remain analytically tractable. Our main result is that the dominant HBI
+modes are localised to the the innermost (~<20%) regions of cool cores. It is
+then probable that, in the nonlinear regime, appreciable field-line insulation
+will be similarly localised. Thus, while radio-mode feedback appears necessary
+in the central few tens of kpc, heat conduction may be capable of offsetting
+radiative losses throughout most of a cool core over a significant fraction of
+the Hubble time. Finally, our linear solutions provide a convenient numerical
+test for the nonlinear codes that tackle the saturation of such convective
+instabilities in the presence of anisotropic transport.",1202.3440v2
+2012-05-22,On the origin of sub-TeV gamma-ray pulsed emission from rotating neutron stars,"Intriguing sub-TeV tails in the pulsed $\gamma$-ray emission from the Crab
+pulsar have been recently discovered by the MAGIC and VERITAS Collaborations.
+They were not clearly predicted by any pulsar model. It is at present argued
+that this emission is produced by electrons in the Inverse Compton process
+occurring either in the outer gap of the pulsar magnetosphere or in the pulsar
+wind region at some distance from the light cylinder. We analyse another
+scenario which is consistent with the basic features of this enigmatic
+emission. It is proposed that this emission is caused by electrons accelerated
+very close to the light cylinder where the $e^\pm$ plasma can not saturate
+induced huge electric fields. Electrons reach energies sufficient for
+production of hard $\gamma$-ray spectra in the curvature radiation process. Due
+to different curvature radii of the leading and trailing magnetic field lines,
+the $\gamma$-ray spectra from separate pulses should extend to different
+maximum energies. The scenario can also explain the lower level $\gamma$-ray
+emission from the interpulse region (between P1 and P2) observed in the Crab
+pulsar light curve. Moreover, we argue that pulsars with parameters close to
+the Vela pulsar should also show pulsed emission with the cut-off at clearly
+lower energies ($\sim$50 GeV) than that observed in the case of the Crab
+pulsar. On the other hand, such tail emission is not expected in pulsars with
+parameters close to the Geminga pulsar. The model also predicts the tail
+$\gamma$-ray emission extending up to $\sim$50 GeV from some millisecond
+pulsars with extreme parameters such as PSR J0218+4243 and PSR J1823-3021A.",1205.4855v1
+2012-06-04,Edge excitations of the canted antiferromagnetic phase of the $ν=0$ quantum Hall state in graphene: a simplified analysis,"We perform a simplified analysis of the edge excitations of the canted
+antiferromagnetic (CAF) phase of the $\nu=0$ quantum Hall state in both
+monolayer and bilayer graphene. Namely, we calculate, within the framework of
+quantum Hall ferromagnetism, the mean-field quasiparticle spectrum of the CAF
+phase neglecting the modification of the order parameter at the edge. We
+demonstrate that, at a fixed perpendicular component $B_\perp$ of the magnetic
+field, the gap $\Delta_\text{edge}$ in the edge excitation spectrum gradually
+decreases upon increasing the parallel component $B_\parallel$, as the CAF
+phase continuously transforms to the fully spin-polarized ferromagnetic (F)
+phase. The edge gap closes completely ($\Delta_\text{edge}=0$) once the F
+phase, characterized by gapless counter-propagating edge excitations, is
+reached at some finite $B_\perp$-dependent value $B_\parallel^*$ and remains
+closed upon further increase of $B_\parallel$. This results in an gradual
+insulator-metal transition, in which the conductance $G \sim (e^2/h)
+\exp(-\Delta_\text{edge}/T)$ grows exponentially with $B_\parallel$ in the
+range $0<B_\parallel<B_\parallel^*$, while in the gapped CAF phase, and
+saturates to a metallic value $G \sim e^2/h$ in the F phase at
+$B_\parallel>B_\parallel^*$. This unique transport feature of the CAF phase
+provides a way to identify and distinguish it from other competing phases of
+the $\nu=0$ quantum Hall state in a tilted-field experiment.",1206.0724v1
+2012-06-20,Stacking-order dependence in thermoelectric transport of biased trilayer graphene,"We numerically study the thermoelectric and thermal transport in trilayer
+graphene with different stacking orders in the presence of interlayer bias
+under a strong perpendicular magnetic field. In biased ABA-stacked case, we
+find that the thermoelectric conductivity displays different asymptotic
+behaviors with the varying of the temperature, similar to that of monolayer
+graphene. In the high temperature regime, the transverse thermoelectric
+conductivity $\alpha_{xy}$ saturates to a universal value $2.77 k_B e/h$ at the
+center of each LL, while it displays a linear temperature dependence at low
+temperatures limit. The calculated transverse thermal conductivity
+$\kappa_{xy}$ exhibits two plateaus away from the band center. The transition
+between the two plateaus is continuous, which is accompanied by a pronounced
+peak in the longitudinal thermal conductivity $\kappa_{xx}$. In biased
+ABC-stacked case, it is found that both the thermoelectric conductivity and
+thermal conductivity have similar properties to the biased bilayer graphene,
+which is consistent with the behavior of a band insulator. The obtained results
+demonstrate the sensitivity of the thermoelectric conductivity to the band gap
+near the Dirac point. We also verify the validity of the Mott-relation and the
+generalized Wiedemann-Franz law.",1206.4387v1
+2012-06-24,The Patterns of High-Level Magnetic Activity Occurring on the Surface of V1285 Aql: The OPEA Model of Flares and DFT Models of Stellar Spots,"Statistically analyzing Johnson UBVR observations of V1285 Aql during the
+three observing seasons, both activity level and behavior of the star are
+discussed in respect to obtained results. We also discuss the out-of-flare
+variation due to rotational modulation. Eighty-three flares were detected in
+the U-band observations of season 2006 . First, depending on statistical
+analyses using the independent samples t-test, the flares were divided into two
+classes as the fast and the slow flares. According to the results of the test,
+there is a difference of about 73 s between the flare-equivalent durations of
+slow and fast flares. The difference should be the difference mentioned in the
+theoretical models. Second, using the one-phase exponential association
+function, the distribution of the flare-equivalent durations versus the flare
+total durations was modeled. Analyzing the model, some parameters such as
+plateau, half-life values, mean average of the flare-equivalent durations,
+maximum flare rise, and total duration times are derived. The plateau value,
+which is an indicator of the saturation level of white-light flares, was
+derived as 2.421{\pm}0.058 s in this model, while half-life is computed as 201
+s. Analyses showed that observed maximum value of flare total duration is 4641
+s, while observed maximum flare rise time is 1817 s. According to these
+results, although computed energies of the flares occurring on the surface of
+V1285 Aql are generally lower than those of other stars, the length of its
+flaring loop can be higher than those of more active stars.",1206.5794v1
+2012-10-20,The Kelvin-Helmholtz instability in Orion: a source of turbulence and chemical mixing,"Hydrodynamical instabilities are believed to power some of the small scale
+(0.1-10 pc) turbulence and chemical mixing in the interstellar medium.
+Identifying such instabilities has always been difficult but recent
+observations of a wavelike structure (the Ripples) in the Orion nebula have
+been interpreted as a signature of the Kelvin-Helmholtz instability (KHI),
+occurring at the interface between the HII region and the molecular cloud.
+However, this has not been verified theoretically. In this letter, we
+investigate theoretically the stability of this interface using observational
+constraints for the local physical conditions. A linear analysis shows that the
+HII/molecular cloud interface is indeed KH unstable for a certain range of
+magnetic field orientation. We find that the maximal growth-rates correspond to
+typical timescales of a few 1e4 years and instability wavelengths of 0.06 to
+0.6 pc. We predict that after 2e5 years the KHI saturates and forms a turbulent
+layer of thickness ~0.5 pc. The KHI can remain in linear phase over a maximum
+distance of 0.75 pc. These spatial and time scales are compatible with the
+Ripples representing the linear phase of the KHI. These results suggest that
+the KHI may be crucial to generate turbulence and to bring heavy elements
+injected by the winds of massive stars in HII regions to colder regions where
+planetary systems around low mass stars are being formed. This could apply to
+the transport of 26Al injected by a massive star in an HII region to the
+nascent solar-system.",1210.5596v2
+2013-04-09,Dynamo effects in magnetorotational turbulence with finite thermal diffusivity,"We investigate the saturation level of hydromagnetic turbulence driven by the
+magnetorotational instability in the case of vanishing net flux. Motivated by a
+recent paper of Bodo, Cattaneo, Mignone, & Rossi, we here focus on the case of
+a non-isothermal equation of state with constant thermal diffusivity. The
+central aim of the paper is to complement the previous result with closure
+parameters for mean-field dynamo models, and to test the hypothesis that the
+dynamo is affected by the mode of heat transport. We perform computer
+simulations of local shearing-box models of stratified accretion disks with
+approximate treatment of radiative heat transport, which is modeled via thermal
+conduction. We study the effect of varying the (constant) thermal diffusivity,
+and apply different vertical boundary conditions. In the case of impenetrable
+vertical boundaries, we confirm the transition from mainly conductive to mainly
+convective vertical heat transport below a critical thermal diffusivity. This
+transition is however much less dramatic when more natural outflow boundary
+conditions are applied. Similarly, the enhancement of magnetic activity in this
+case is less pronounced. Nevertheless, heating via turbulent dissipation
+determines the thermodynamic structure of accretion disks, and clearly affects
+the properties of the related dynamo. This effect may however have been
+overestimated in previous work, and a careful study of the role played by
+boundaries will be required.",1304.2587v1
+2013-12-04,Pulsar wind model for the spin-down behavior of intermittent pulsars,"Intermittent pulsars are part-time radio pulsars. They have higher slow down
+rate in the on state (radio-loud) than in the off state (radio-quiet). This
+gives the evidence that particle wind may play an important role in pulsar
+spindown. The effect of particle acceleration is included in modeling the
+rotational energy loss rate of the neutron star. Applying the pulsar wind model
+to the three intermittent pulsars (PSR B1931+24, PSR J1841-0500, and PSR
+J1832+0029), their magnetic field and inclination angle are calculated
+simultaneously. The theoretical braking indices of intermittent pulsars are
+also given. In the pulsar wind model, the density of the particle wind can
+always be the Goldreich-Julian density. This may ensure that different on
+states of intermittent pulsars are stable. The duty cycle of particle wind can
+be determined from timing observations. It is consistent with the duty cycle of
+the on state. Inclination angle and braking index observations of intermittent
+pulsars may help to test different models of particle acceleration. At present,
+the inverse Compton scattering induced space charge limited flow with field
+saturation model can be ruled out.",1312.1016v3
+2014-03-06,The Evolution of Writhe in Kink-Unstable Flux Ropes and Erupting Filaments,"The helical kink instability of a twisted magnetic flux tube has been
+suggested as a trigger mechanism for solar filament eruptions and coronal mass
+ejections (CMEs). In order to investigate if estimations of the pre-eruptive
+twist can be obtained from observations of writhe in such events, we
+quantitatively analyze the conversion of twist into writhe in the course of the
+instability, using numerical simulations. We consider the line tied,
+cylindrically symmetric Gold-Hoyle flux rope model and measure the writhe using
+the formulae by Berger and Prior which express the quantity as a single
+integral in space. We find that the amount of twist converted into writhe does
+not simply scale with the initial flux rope twist, but depends mainly on the
+growth rates of the instability eigenmodes of higher longitudinal order than
+the basic mode. The saturation levels of the writhe, as well as the shapes of
+the kinked flux ropes, are very similar for considerable ranges of initial flux
+rope twists, which essentially precludes estimations of pre-eruptive twist from
+measurements of writhe. However, our simulations suggest an upper twist limit
+of $\sim 6\pi$ for the majority of filaments prior to their eruption.",1403.1565v1
+2014-05-15,Radial Stresses and Energy Transport in Accretion Disks,"Early in the study of viscous accretion disks it was realized that energy
+transfers from distant sources must be important, not least because the flow at
+the disk midplane in the bulk of the disk is likely outwards, out of the
+gravitational potential well. If the source of the viscosity is powered by
+accretion, such as in the case of the magneto-rotational instability, such
+distant energy sources must lie in the innermost regions of the disk, where
+accretion occurs even at the midplane. We argue here that modulations in this
+energy supply can alter the accretion rate on dynamical, rather than far longer
+viscous, time scales. This means that both the steady state value of and
+fluctuations in the inner disk's accretion rate, depending on the details of
+the inner boundary condition and occurring on the inner disk's rapid evolution
+time, can affect the outer disk. This is particularly interesting because
+observations have shown that disk accretion is not steady (e.g.~EX Lupi type
+objects). We also note that the power supplied to shearing boxes is set by the
+boxes themselves rather than the physical energy fluxes in a global disk. That
+is, their saturated magnetic field is not subject to the full set of energy
+constraints present in an actual disk. Our analysis suggests that large scale
+radial transport of energy has a critical impact on the evolution and
+variability of accretion disks.",1405.3991v2
+2014-09-02,On seed island generation and the non-linear self-consistent interaction of the tearing mode with electromagnetic gyro-kinetic turbulence,"The multi-scale interaction of self-consistently driven magnetic islands with
+electromagnetic turbulence is studied within the three dimensional, toroidal
+gyro-kinetic framework. It can be seen that, even in the presence of
+electromagnetic turbulence the linear structure of the mode is retained.
+Turbulent fluctuations do not destroy the growing island early in its
+development, which then maintains a coherent form as it grows.
+  The island is seeded by the electromagnetic turbulence fluctuations, which
+provide an initial island structure through nonlinear interactions and which
+grows at a rate significantly faster than the linear tearing growth rate. These
+island structures saturate at a width that is approximately $\rho_{i}$ in size.
+In the presence of turbulence the island then grows at the linear rate even
+though the island is significantly wider than the resonant layer width, a
+regime where the island is expected to grow at a significantly reduced
+non-linear rate.
+  A large degree of stochastisation around the separatrix, and an almost
+complete break down of the X-point is seen. This significantly reduces the
+effective island width.",1409.0648v2
+2014-11-12,Cross-calibration of the Transition Radiation Detector of AMS-02 for an Energy Measurement of Cosmic-Ray Ions,"Since May 2011 the AMS-02 experiment is installed on the International Space
+Station and is observing cosmic radiation. It consists of several
+state-of-the-art sub-detectors, which redundantly measure charge and energy of
+traversing particles. Due to the long exposure time of AMS-02 of many years the
+measurement of momentum for protons and ions is limited systematically by the
+spatial resolution and magnetic field strength of the silicon tracker. The
+maximum detectable rigidity for protons is about 1.8~TV, for helium about
+3.6~TV. We investigate the possibility to extend the range of the energy
+measurement for heavy nuclei ($Z\geq2$) with the transition radiation detector
+(TRD). The response function of the TRD shows a steep increase in signal from
+the level of ionization at a Lorentz factor $\gamma$ of about 500 to
+$\gamma\approx20000$, where the transition radiation signal saturates. For
+heavy ions the signal fluctuations in the TRD are sufficiently small to allow
+an energy measurement with the TRD beyond the limitations of the tracker. The
+energy resolution of the TRD is determined and reaches a level of about 20\%
+for boron ($Z=5$). After adjusting the operational parameters of the TRD a
+measurement of boron and carbon could be possible up to 5~TeV/nucleon.",1411.3329v1
+2015-02-01,"Enhanced conduction band density of states in intermetallic EuTSi$_3$ (T=Rh, Ir)","We report on the physical properties of single crystalline EuRhSi$_3$ and
+polycrystalline EuIrSi$_3$, inferred from magnetisation, electrical transport,
+heat capacity and $^{151}$Eu M\""ossbauer spectroscopy. These previously known
+compounds crystallise in the tetragonal BaNiSn$_3$-type structure. The single
+crystal magnetisation in EuRhSi$_3$ has a strongly anisotropic behaviour at 2 K
+with a spin-flop field of 13 T, and we present a model of these magnetic
+properties which allows the exchange constants to be determined. In both
+compounds, specific heat shows the presence of a cascade of two close
+transitions near 50 K, and the $^{151}$Eu M\""ossbauer spectra demonstrate that
+the intermediate phase has an incommensurate amplitude modulated structure. We
+find anomalously large values, with respect to other members of the series, for
+the RKKY N\'eel temperature, for the spin-flop field (13 T), for the spin-wave
+gap ($\simeq$ 20-25 K) inferred from both resistivity and specific heat data,
+for the spin-disorder resistivity in EuRhSi$_3$ ($\simeq 35$ $\mu$Ohm.cm) and
+for the saturated hyperfine field (52 T). We show that all these quantities
+depend on the electronic density of states at the Fermi level, implying that
+the latter must be strongly enhanced in these two materials. EuIrSi$_3$
+exhibits a giant magnetoresistance ratio, with values exceeding 600 % at 2 K in
+a field of 14 T.",1502.00285v1
+2015-02-02,Superconductivity emerging from suppressed large magnetoresistant state in WTe2,"The recent discovery of large and non-saturating magnetoresistance (LMR) in
+WTe2 provides a unique playground to find new phenomena and significant
+perspective for potential applications. Here we report the first observation of
+superconductivity near the proximity of suppressed LMR state in pressurized
+WTe2 through high-pressure synchrotron X-ray diffraction, electrical
+resistance, magnetoresistance, and ac magnetic susceptibility measurements. It
+is found that the positive magnetoresistance effect can be turned off at a
+critical pressure of 10.5 GPa without crystal structure change and
+superconductivity emerges simultaneously. The maximum superconducting
+transition temperature can be reached to 6.5 K at ~15 GPa and it decreases down
+to 2.6 K at ~25 GPa. In-situ high pressure Hall coefficient measurements at 10
+K demonstrate that elevating pressure decreases hole carrier's population but
+increases electron carrier's population. Significantly, at the critical
+pressure, we observed a sign change in the Hall coefficient, indicating a
+possible Lifshitz-type quantum phase transition in WTe2.",1502.00493v2
+2015-02-03,Transitions to valence-bond solid order in a honeycomb lattice antiferromagnet,"We use Quantum Monte-Carlo methods to study the ground state phase diagram of
+a S=1/2 honeycomb lattice magnet in which a nearest-neighbor antiferromagnetic
+exchange J (favoring N\'eel order) competes with two different multi-spin
+interaction terms: a six-spin interaction Q_3 that favors columnar valence-bond
+solid (VBS) order, and a four-spin interaction Q_2 that favors staggered VBS
+order. For Q_3 ~ Q_2 >> J, we establish that the competition between the two
+different VBS orders stabilizes N\'eel order in a large swathe of the phase
+diagram even when J is the smallest energy-scale in the Hamiltonian. When Q_3
+>> (Q_2,J) (Q_2 >> (Q_3,J)), this model exhibits at zero temperature phase
+transition from the N\'eel state to a columnar (staggered) VBS state. We
+establish that the N\'eel-columnar VBS transition is continuous for all values
+of Q_2, and that critical properties along the entire phase boundary are
+well-characterized by critical exponents and amplitudes of the non-compact CP^1
+(NCCP^1) theory of deconfined criticality, similar to what is observed on a
+square lattice. However, a surprising three-fold anisotropy of the phase of the
+VBS order parameter at criticality, whose presence was recently noted at the
+Q_2=0 deconfined critical point, is seen to persist all along this phase
+boundary. We use a classical analogy to explore this by studying the critical
+point of a three-dimensional XY model with a four-fold anisotropy field which
+is known to be weakly irrelevant at the three-dimensional XY critical point. In
+this case, we again find that the critical anisotropy appears to saturate to a
+nonzero value over the range of sizes accessible to our simulations.",1502.01035v1
+2015-02-09,Mutual independence of critical temperature and superfluid density under pressure in optimally electron-doped superconducting LaFeAsO$_{1-x}$F$_{x}$,"The superconducting properties of LaFeAsO$_{1-x}$F$_{x}$ in conditions of
+optimal electron-doping are investigated upon the application of external
+pressure up to $\sim 23$ kbar. Measurements of muon-spin spectroscopy and dc
+magnetometry evidence a clear mutual independence between the critical
+temperature $T_{c}$ and the low-temperature saturation value for the ratio
+$n_{s}/m^{*}$ (superfluid density over effective band mass of Cooper pairs).
+Remarkably, a dramatic increase of $\sim 30$ % is reported for $n_{s}/m^{*}$ at
+the maximum pressure value while $T_{c}$ is substantially unaffected in the
+whole accessed experimental window. We argue and demonstrate that the
+explanation for the observed results must take the effect of non-magnetic
+impurities on multi-band superconductivity into account. In particular, the
+unique possibility to modify the ratio between intra-band and inter-bands
+scattering rates by acting on structural parameters while keeping the amount of
+chemical disorder constant is a striking result of our proposed model.",1502.02713v1
+2015-03-20,Finite-temperature superconducting correlations of the Hubbard model,"We utilize numerical linked-cluster expansions (NLCEs) and the determinantal
+quantum Monte Carlo algorithm to study pairing correlations in the square
+lattice Hubbard model. To benchmark the NLCE, we first locate the
+finite-temperature phase transition of the attractive model to a
+superconducting state away from half filling. We then explore the
+superconducting properties of the repulsive model for the d-wave and extended
+s-wave pairing symmetries. The pairing structure factor shows a strong tendency
+to d-wave pairing and peaks at an interaction strength comparable to the
+bandwidth. The extended s-wave structure factor and correlation length are
+larger at higher temperatures but clearly saturate as temperature is lowered,
+whereas the d-wave counterparts, which start off lower at high temperatures,
+continue to rise near half filling. This rise is even more dramatic in the
+d-wave susceptibility. The convergence of NLCEs breaks down as the
+susceptibilities and correlation lengths become large, so we are unable to
+determine the onset of long-range order. However, our results extend the
+conclusion, previously restricted to only magnetic and charge correlations,
+that NLCEs offer unique window into pairing in the Hubbard model at strong
+coupling.",1503.06213v2
+2015-05-05,Direct evidence for the emergence of a pressure induced nodal superconducting gap in the iron-based superconductor Ba_0.65Rb_0.35Fe_2As_2,"Identifying the superconducting (SC) gap structure of the iron-based
+high-temperature superconductors (Fe-HTS's) remains a key issue for the
+understanding of superconductivity in these materials. In contrast to other
+unconventional superconductors, in the Fe-HTS's both $d$-wave and extended
+s-wave pairing symmetries are close in energy, with the latter believed to be
+generally favored over the former. Probing the proximity between these very
+different SC states and identifying experimental parameters that can tune them,
+are of central interest. Here we report high-pressure muon spin rotation
+experiments on the temperature-dependent magnetic penetration depth (lambda) in
+the optimally doped Fe-HTS Ba_0.65Rb_0.35Fe_2As_2. At ambient pressure this
+material is known to be a nodeless s-wave superconductor. Upon pressure a
+strong decrease of (lambda) is observed, while the SC transition temperature
+remains nearly constant. More importantly, the low-temperature behavior of
+(1/lambda^{2}) changes from exponential saturation at zero pressure to a
+power-law with increasing pressure, providing unambiguous evidence that
+hydrostatic pressure promotes nodal SC gaps. Comparison to microscopic models
+favors a d-wave over a nodal s^{+-}-wave pairing as the origin of the nodes.
+Our results provide a new route of understanding the complex topology of the SC
+gap in Fe-HTS's.",1505.01223v1
+2015-05-07,A Simple Way to Estimate the Soft X-ray Class of Far-Side Solar Flares Observed with STEREO/EUVI,"Around the peaks of substantial flares, bright artifact nearly horizontal
+saturation streaks (B-streaks) corresponding to the brightest parts of the
+flare sources appear in the STEREO/EUVI 195 A images. We show that the length
+of such B-streaks can be used for the solution of an actual problem of
+evaluating the soft X-ray flux and class of far-side flares registered with
+double STEREO spacecraft but invisible from Earth. For this purpose from data
+on about 350 flares observed from January 2007 to July 2014 (mainly exceeding
+the GOES M1.0 level) both with GOES and STEREO, an empirical relation is
+established correlating the GOES 1-8 A peak flux and the B-streak length. This
+allowed us for the same years to estimate the soft X-ray classes for
+approximately 65 strong far-side flares observed by STEREO. The results of this
+simple and prompt method are consistent with the estimations of Nitta et al.
+(Solar Phys., 288, 241, 2013) based on the calculations of the EUVI full-disk
+digital number output. In addition, we studied some features of the B-streaks
+in impulsive and long-duration flares and demonstrated that B-streaks in
+several consecutive EUVI images can be used to reconstruct a probable time
+history of strong far-side flares.",1505.01649v2
+2015-05-20,Scaling properties of a ferromagnetic thin film model at the depinning transition,"In this paper, we perform a detailed study of the scaling properties of a
+ferromagnetic thin film model. Recently, interest has increased in the scaling
+properties of the magnetic domain wall (MDW) motion in disordered media when an
+external driving field is present. We consider a (1+1)-dimensional model, based
+on evolution rules, able to describe the MDW avalanches. The global interface
+width of this model shows Family-Vicsek scaling with roughness exponent
+$\zeta\simeq 1.585$ and growth exponent $\beta\simeq 0.975$. In contrast, this
+model shows scaling anomalies in the interface local properties characteristic
+of other systems with depinning transition of the MDW, e.g. quenched
+Edwards-Wilkinson (QEW) equation and random-field Ising model (RFIM) with
+driving. We show that, at the depinning transition, the saturated average
+velocity $v_\mathrm{sat}\sim f^\theta$ vanished very slowly (with $\theta\simeq
+0.037$) when the reduced force $f=p/p_\mathrm{c}-1\to 0^{+}$. The simulation
+results show that this model verifies all accepted scaling relations which
+relate the global exponents and the correlation length (or time) exponents,
+valid in systems with depinning transition. Using the interface tilting method,
+we show that the model, close to the depinning transition, exhibits a
+nonlinearity similar to the one included in the Kardar-Parisi-Zhang (KPZ)
+equation. The nonlinear coefficient $\lambda\sim f^{-\phi}$ with $\phi\simeq
+-1.118$, which implies that $\lambda\to 0$ as the depinning transition is
+approached, a similar qualitatively behaviour to the driven RFIM. We conclude
+this work by discussing the main features of the model and the prospects opened
+by it.",1505.05223v2
+2015-07-13,Early Time Dynamics of Gluon Fields in High Energy Nuclear Collisions,"Nuclei colliding at very high energy create a strong, quasi-classical gluon
+field during the initial phase of their interaction. We present an analytic
+calculation of the initial space-time evolution of this field in the limit of
+very high energies using a formal recursive solution of the Yang-Mills
+equations. We provide analytic expressions for the initial chromo-electric and
+chromo-magnetic fields and for their energy-momentum tensor. In particular, we
+discuss event-averaged results for energy density and energy flow as well as
+for longitudinal and transverse pressure of this system. For example, we find
+that the ratio of longitudinal to transverse pressure very early in the system
+behaves as $p_L/p_T =
+-[1-\frac{3}{2a}(Q\tau)^2]/[1-\frac{1}{a}(Q\tau)^2]+\mathcal{O}(Q\tau)^4$ where
+$\tau$ is the longitudinal proper time, $Q$ is related to the saturation scales
+$Q_s$ of the two nuclei, and $a = \ln (Q^2/\hat{m}^2)$ with $\hat m$ a scale to
+be defined later. Our results are generally applicable if $\tau \lesssim 1/Q$.
+As already discussed in a previous paper, the transverse energy flow $S^i$ of
+the gluon field exhibits hydrodynamic-like contributions that follow transverse
+gradients of the energy density $\nabla^i \varepsilon$. In addition, a
+rapidity-odd energy flow also emerges from the non-abelian analog of Gauss' Law
+and generates non-vanishing angular momentum of the field. We will discuss the
+space-time picture that emerges from our analysis and its implications for
+observables in heavy ion collisions.",1507.03524v1
+2015-08-23,Fire Hose instability driven by alpha particle temperature anisotropy,"We investigate properties of a solar wind-like plasma including a secondary
+alpha particle population exhibiting a parallel temperature anisotropy with
+respect to the background magnetic field, using linear and quasi-linear
+predictions and by means of one-dimensional hybrid simulations. We show that
+anisotropic alpha particles can drive a parallel fire hose instability
+analogous to that generated by protons, but that, remarkably, the instability
+can be triggered also when the parallel plasma beta of alpha particles is below
+unity. The wave activity generated by the alpha anisotropy affects the
+evolution of the more abundant protons, leading to their anisotropic heating.
+When both ion species have sufficient parallel anisotropies both of them can
+drive the instability, and we observe generation of two distinct peaks in the
+spectra of the fluctuations, with longer wavelengths associated to alphas and
+shorter ones to protons. If a non-zero relative drift is present, the unstable
+modes propagate preferentially in the direction of the drift associated with
+the unstable species. The generated waves scatter particles and reduce their
+temperature anisotropy to marginally stable state, and, moreover, they
+significantly reduce the relative drift between the two ion populations. The
+coexistence of modes excited by both species leads to saturation of the plasma
+in distinct regions of the beta/anisotropy parameter space for protons and
+alpha particles, in good agreement with in situ solar wind observations. Our
+results confirm that fire hose instabilities are likely at work in the solar
+wind and limit the anisotropy of different ion species in the plasma.",1508.05638v1
+2015-09-15,Novel valley depolarization dynamics and valley Hall effect of exciton in mono- and bilayer MoS$_2$,"We investigate the valley depolarization dynamics and valley Hall effect of
+exciton due to the electron-hole exchange interaction in mono- and bilayer
+MoS$_2$ by solving the kinetic spin Bloch equations. The effect of the exciton
+energy spectra by the electron-hole exchange interaction is explicitly
+considered. For the valley depolarization dynamics, in the monolayer MoS$_2$,
+it is found that in the strong scattering regime, the conventional motional
+narrowing picture is no longer valid, and a novel valley depolarization channel
+is opened. For the valley Hall effect of exciton, in both the mono- and bilayer
+MoS$_2$, with the exciton equally pumped in the K and K' valleys, the system
+can evolve into the equilibrium state where the valley polarization is parallel
+to the effective magnetic field due to the exchange interaction. With the drift
+of this equilibrium state by applied uniaxial strain, the exchange interaction
+can induce the {\it momentum-dependent} valley/photoluminesence polarization,
+which leads to the valley/photoluminesence Hall current. Specifically, the
+disorder strength dependence of the valley Hall conductivity is revealed. In
+the strong scattering regime, the valley Hall conductivity decreases with the
+increase of the disorder strength; whereas in the weak scattering regime, it
+saturates to a constant, which can be much larger than the one in Fermi system
+due to the absence of the Pauli blocking.",1509.04404v1
+2015-10-05,Depinning of disordered bosonic chains,"We consider one-dimensional bosonic chains with a repulsive boson-boson
+interaction that decays exponentially on large length-scales. This model
+describes transport of Cooper-pairs in a Josepshon junction array, or transport
+of magnetic flux quanta in quantum-phase-slip ladders, i.e. arrays of
+superconducting wires in a ladder-configuration that allow for the coherent
+tunnelling of flux quanta. In the low-frequency, long wave-length regime these
+chains can be mapped to an effective model of a one-dimensional elastic field
+in a disordered potential. The onset of transport in these systems, when biased
+by external voltage, is described by the standard depinning theory of elastic
+media in disordered pinning potentials. We numerically study the regimes that
+are of relevance for quantum-phase-slip ladders. These are (i) very short
+chains and (ii) the regime of weak disorder. For chains shorter than the
+typical pinning length, i.e., the Larkin length, the chains reach a saturation
+regime where the depinning voltage does not depend on the decay length of the
+repulsive interaction. In the regime of weak disorder we find an emergent
+correlation length-scale that depends on the disorder strength. For arrays
+shorter than this length the onset of transport is similar to the clean arrays,
+i.e., is due to the penetration of solitons into the array. We discuss the
+depinning scenarios for longer arrays in this regime.",1510.01383v1
+2016-02-05,Large nonsaturating magnetoresistance and signature of non-degenerate Dirac nodes in ZrSiS,"While the discovery of Dirac and Weyl type excitations in electronic systems
+is a major breakthrough in recent condensed matter physics, finding appropriate
+materials for fundamental physics and technological applications, is an
+experimental challenge. In all the reported materials, linear dispersion
+survives only up to a few hundred meV from the Dirac or Weyl nodes. On the
+other hand, real materials are subject to uncontrolled doping during
+preparation and thermal effect near room temperature can hinder the rich
+physics. In ZrSiS, ARPES measurements have shown an unusually robust linear
+dispersion (up to $\sim$2 eV) with multiple non-degenerate Dirac nodes. In this
+context, we present the magnetotransport study on ZrSiS crystal, which
+represents a large family of materials (\textit{WHM} with \textit{W} = Zr, Hf;
+\textit{H} = Si, Ge, Sn; \textit{M} = O, S, Se, Te) with identical band
+topology. Along with extremely large and non-saturating magnetoresistance (MR),
+$\sim$ 1.4 $\times$ 10$^{5}$ \% at 2 K and 9 T, it shows strong anisotropy
+depending on the direction of the magnetic field. Quantum oscillation and Hall
+effect measurements have revealed large hole and small electron Fermi pockets.
+Non-trivial $\pi$ Berry phase confirms the Dirac fermionic nature for both
+types of charge carriers. The long-sought relativistic phenomenon of massless
+Dirac fermions, known as Adler-Bell-Jackiw chiral anomaly, has also been
+observed.",1602.01993v3
+2016-03-05,Topological phase transition induced extreme magnetoresistance in TaSb$_{2}$,"We report extremely large positive magnetoresistance of 1.72 million percent
+in single crystal TaSb$_{2}$ at moderate conditions of 1.5 K and 15 T. The
+quadratic growth of magnetoresistance (MR $\propto\,B^{1.96}$) is not
+saturating up to 15 T, a manifestation of nearly perfect compensation with
+$<0.1\%$ mismatch between electron and hole pockets in this semimetal. The
+compensation mechanism is confirmed by temperature-dependent MR, Hall and
+thermoelectric coefficients of Nernst and Seebeck, revealing two pronounced
+Fermi surface reconstruction processes without spontaneous symmetry breaking,
+\textit{i.e.} Lifshitz transitions, at around 20 K and 60 K, respectively.
+Using quantum oscillations of magnetoresistance and magnetic susceptibility,
+supported by density-functional theory calculations, we determined that the
+main hole Fermi surface of TaSb$_{2}$ forms a unique shoulder structure along
+the $F-L$ line. The flat band top of this shoulder pocket is just a few meV
+above the Fermi level, leading to the observed topological phase transition at
+20 K when the shoulder pocket disappears. Further increase in temperature
+pushes the Fermi level to the band top of the main hole pocket, induced the
+second Lifshitz transition at 60 K when hole pocket vanishes completely.",1603.01717v1
+2016-03-15,Gyrokinetic simulations of fusion plasmas using a spectral velocity space representation,"Magnetic confinement fusion reactors suffer severely from heat and particle
+losses through turbulent transport, which has inspired the construction of ever
+larger and more expensive reactors. Numerical simulations are vital to their
+design and operation, but particle collisions are too infrequent for fluid
+descriptions to be valid. Instead, strongly magnetised fusion plasmas are
+described by the gyrokinetic equations, a nonlinear integro-differential system
+for evolving the particle distribution functions in a five-dimensional position
+and velocity space, and the consequent electromagnetic field. Due to the high
+dimensionality, simulations of small reactor sections require hundreds of
+thousands of CPU hours on High Performance Computing platforms.
+  We develop a Hankel-Hermite spectral representation for velocity space that
+exploits structural features of the gyrokinetic system. The representation
+exactly conserves discrete free energy in the absence of explicit dissipation,
+while our Hermite hypercollision operator captures Landau damping with few
+variables. Calculation of the electromagnetic fields becomes purely local,
+eliminating inter-processor communication in, and vastly accelerating, searches
+for linear instabilities. We implement these ideas in SpectroGK, an efficient
+parallel code.
+  Turbulent fusion plasmas may dissipate free energy through linear phase
+mixing to fine scales in velocity space, as in Landau damping, or through a
+nonlinear cascade to fine scales in physical space, as in hydrodynamic
+turbulence. Using SpectroGK to study saturated electrostatic drift-kinetic
+turbulence, we find that the nonlinear cascade suppresses linear phase mixing
+at energetically-dominant scales, so the turbulence is fluid-like. We use this
+observation to derive Fourier-Hermite spectra for the electrostatic potential
+and distribution function, and confirm these spectra with simulations.",1603.04727v1
+2016-04-27,Compensated semimetal LaSb with unsaturated magnetoresistance,"By combining angle-resolved photoemission spectroscopy and quantum
+oscillation measurements, we performed a comprehensive investigation on the
+electronic structure of LaSb, which exhibits near-quadratic extremely large
+magnetoresistance (XMR) without any sign of saturation at magnetic fields as
+high as 40 T. We clearly resolve one spherical and one intersecting-ellipsoidal
+hole Fermi surfaces (FSs) at the Brillouin zone (BZ) center $\Gamma$ and one
+ellipsoidal electron FS at the BZ boundary $X$. The hole and electron carriers
+calculated from the enclosed FS volumes are perfectly compensated, and the
+carrier compensation is unaffected by temperature. We further reveal that LaSb
+is topologically trivial but share many similarities with the Weyl semimetal
+TaAs family in the bulk electronic structure. Based on these results, we have
+examined the mechanisms that have been proposed so far to explain the
+near-quadratic XMR in semimetals.",1604.08142v2
+2016-07-06,Quadrupole Splittings in the near-infrared spectrum of $^{14}$NH$_3$,"Sub-Doppler, saturation dip, spectra of lines in the $v_1 + v_3$, $v_1 +
+2v_4$ and $v_3 + 2v_4$ bands of $^{14}$NH$_3$ have been measured by frequency
+comb-referenced diode laser absorption spectroscopy. The observed spectral line
+widths are dominated by transit time broadening, but show resolved or
+partially-resolved hyperfine splittings that are primarily determined by the
+$^{14}$N quadrupole coupling. Modeling of the observed line shapes based on the
+known hyperfine level structure of the ground state of the molecule shows that,
+in nearly all cases, the excited state level has hyperfine splittings similar
+to the same rotational level in the ground state. The data provide accurate
+frequencies for the line positions and easily separate lines overlapped in
+Doppler-limited spectra. The observed hyperfine splittings can be used to make
+and confirm rotational assignments and ground state combination differences
+obtained from the measured frequencies are comparable in accuracy to those
+obtained from conventional microwave spectroscopy. One upper state level shows
+very clear differences from the expected splittings. Examination of the known
+vibration-rotation level structure shows there is a near degeneracy between
+this level in $v_1+v_3$ and a rotational level in the $v_1 + 2v_4$ manifold
+which is of the appropriate symmetry to be mixed by magnetic hyperfine terms
+that couple ortho- and para- forms of the molecule.",1607.01646v2
+2016-08-02,"A path towards understanding the rotation-activity relation of M dwarfs with K2 mission, X-ray and UV data","We study the relation between stellar rotation and magnetic activity for a
+sample of 134 bright, nearby M dwarfs observed in the Kepler Two-Wheel (K2)
+mission during campaigns C0 to C4. The K2 lightcurves yield photometrically
+derived rotation periods for 97 stars (79 of which without previous period
+measurement), as well as various measures for activity related to cool spots
+and flares. We find a clear difference between fast and slow rotators with a
+dividing line at a period of ~10d at which the activity level changes abruptly.
+All photometric diagnostics of activity (spot cycle amplitude, flare peak
+amplitude and residual variability after subtraction of spot and flare
+variations) display the same dichotomy, pointing to a quick transition between
+a high-activity mode for fast rotators and a low-activity mode for slow
+rotators. This unexplained behavior is reminiscent of a dynamo mode-change seen
+in numerical simulations that separates a dipolar from a multipolar regime. A
+substantial number of the fast rotators are visual binaries. A tentative
+explanation is accelerated disk evolution in binaries leading to higher initial
+rotation rates on the main-sequence and associated longer spin-down and
+activity lifetimes. We combine the K2 rotation periods with archival X-ray and
+UV data. X-ray, FUV and NUV detections are found for 26, 41, and 11 stars from
+our sample, respectively. Separating the fast from the slow rotators, we
+determine for the first time the X-ray saturation level separately for early-
+and for mid-M stars.",1608.00772v1
+2016-10-18,"Preparation, structure and giant magnetoresistance of electrodeposited Fe Co/Cu multilayers","No systematic studies have been carried out on the giant magnetoresistance
+(GMR) of electrodeposited (ED) Fe-Co/Cu multilayers since the elaboration of a
+method for the optimization of the Cu layer deposition potential. In this
+paper, we present results on the electrochemical optimization of the Cu layer
+deposition potential which was found to depend on the relative iron
+concentration in the bath. An X-ray diffraction study of ED Fe5Co95(1.5
+nm)/Cu(dCu) multilayers with dCu ranging from 0.8 nm to 10 nm revealed an fcc
+structure. For most of the multilayers, a weak superlattice satellite
+reflection could be identified. The room-temperature magnetoresistance was
+studied in detail as a function of the individual layer thicknesses.
+Multilayers with Cu layer thicknesses above about 1.5 nm were found to exhibit
+a GMR behavior with a maximum GMR of about 5 % and a typical saturation field
+of 1 kOe. The GMR magnitude decreased with increasing Fe-content in the
+magnetic layer. The spacer layer thickness evolution of the MR data was
+established in detail after separating the ferromagnetic and superparamagnetic
+GMR contributions and no oscillatory GMR was found. A comparison with
+literature data on both physically deposited and ED Fe-Co/Cu multilayers is
+also made.",1610.05631v1
+2016-11-17,On the measurements of numerical viscosity and resistivity in Eulerian MHD codes,"We propose a simple ansatz for estimating the value of the numerical
+resistivity and the numerical viscosity of any Eulerian MHD code. We test this
+ansatz with the help of simulations of the propagation of (magneto)sonic waves,
+Alfven waves, and the tearing mode instability using the MHD code Aenus. By
+comparing the simu- lation results with analytical solutions of the
+resistive-viscous MHD equations and an empirical ansatz for the growth rate of
+tearing modes we measure the numerical viscosity and resistivity of Aenus. The
+comparison shows that the fast-magnetosonic speed and wavelength are the
+characteristic velocity and length, respectively, of the aforementioned
+(relatively simple) systems. We also determine the dependance of the numerical
+viscosity and resistivity on the time integration method, the spatial
+reconstruction scheme and (to a lesser extent) the Riemann solver employed in
+the simulations. From the measured results we infer the numerical resolution
+(as a function of the spatial reconstruction method) required to properly
+resolve the growth and saturation level of the magnetic field amplified by the
+magnetorotational instability in the post-collapsed core of massive stars. Our
+results show that it is to the best advantage to resort to ultra-high order
+methods (e.g., 9th-order Monotonicity Preserving method) to tackle this problem
+properly, in particular in three dimensional simulations.",1611.05858v2
+2017-01-07,Spectrum of the Nuclear Environment for GaAs Spin Qubits,"Using a singlet-triplet spin qubit as a sensitive spectrometer of the GaAs
+nuclear spin bath, we demonstrate that the spectrum of Overhauser noise agrees
+with a classical spin diffusion model over six orders of magnitude in
+frequency, from 1 mHz to 1 kHz, is flat below 10 mHz, and falls as $1/f^2$ for
+frequency $f \! \gtrsim \! 1$ Hz. Increasing the applied magnetic field from
+0.1 T to 0.75 T suppresses electron-mediated spin diffusion, which decreases
+spectral content in the $1/f^2$ region and lowers the saturation frequency,
+each by an order of magnitude, consistent with a numerical model. Spectral
+content at megahertz frequencies is accessed using dynamical decoupling, which
+shows a crossover from the few-pulse regime ($\lesssim \! 16$ $\pi$-pulses),
+where transverse Overhauser fluctuations dominate dephasing, to the many-pulse
+regime ($\gtrsim \! 32$ $\pi$-pulses), where longitudinal Overhauser
+fluctuations with a $1/f$ spectrum dominate.",1701.01855v2
+2017-01-09,Gyrokinetic theory for particle transport in fusion plasmas,"Predicting the dynamics of a thermonuclear plasma during a magnetic
+confinement experiment is fundamental in order to make nuclear fusion a
+reliable source of energy. The development of a set of equations describing the
+plasma evolution on a given time scale is the main requirement to reach this
+goal. A limited amount of works have studied in a self-consistent way
+collisional transport and fluctuation induced transport. The motivation of this
+work stems from the fundamental importance of the self-consistency of the
+adopted description in order to understand transport processes on the energy
+confinement (transport) time scale because of the mutual interaction between
+collisions and turbulence. In turn, this is crucial in order to predict fluxes
+of particle and energy and, ultimately, the overall plasma evolution. Using
+flux coordinates and the drift ordering we derive a set of evolutions equations
+for the number of particles and the energy density on the transport time scale.
+These equations show the interplay between collisions and fluctuations and, in
+particular, show that fluctuations may enhance collisional transport while the
+collisions can damp long lived structures formed by saturated instabilities,
+i.e zonal structures. Fluctuation induced fluxes are described using
+gyrokinetic field theory, which makes a comparison with the theory of phase
+space zonal structures possible, revealing that the fluctuations induced part
+of the transport equations can be obtained by taking the proper moment of the
+long length scale limit of the equation governing the evolution of phase space
+zonal structures. Finally, we show that plasma nonlinear evolution can yield to
+structures formation that are characterized by mesoscales, intermediate between
+the typical ones of plasma turbulence and those of the reference plasma
+equilibrium.",1701.02202v1
+2017-01-11,The intrinsic and interstellar broadband linear polarization of nearby FGK dwarfs,"We present linear polarization measurements of nearby FGK dwarfs to
+parts-per-million (ppm) precision. Before making any allowance for interstellar
+polarization, we found that the active stars within the sample have a mean
+polarization of 28.5 +/- 2.2 ppm while the inactive stars have a mean of 9.6
++/- 1.5 ppm. Amongst inactive stars we initially found no difference between
+debris disk host stars (9.1 +/- 2.5 ppm) and the other FGK dwarfs (9.9 +/- 1.9
+ppm). We develop a model for the magnitude and direction of interstellar
+polarization for nearby stars. When we correct the observations for the
+estimated interstellar polarization we obtain 23.0 +/-2.2 ppm for the active
+stars, 7.8 +/- 2.9 ppm for the inactive debris disk host stars and 2.9 +/- 1.9
+ppm for the other inactive stars. The data indicates that whilst some debris
+disk host stars are intrinsically polarized most inactive FGK dwarfs have
+negligible intrinsic polarization, but that active dwarfs have intrinsic
+polarization at levels ranging up to ~45 ppm. We briefly consider a number of
+mechanisms, and suggest differential saturation of spectral lines in the
+presence of magnetic fields is the best able to explain the polarization seen
+in active dwarfs. The results have implications for current attempts to detect
+polarized reflected light from hot Jupiters by looking at the combined light of
+the star and planet.",1701.02890v1
+2017-02-17,Scalable explicit implementation of anisotropic diffusion with Runge-Kutta-Legendre super-time-stepping,"An important ingredient in numerical modelling of high temperature magnetised
+astrophysical plasmas is the anisotropic transport of heat along magnetic field
+lines from higher to lower temperatures.Magnetohydrodynamics (MHD) typically
+involves solving the hyperbolic set of conservation equations along with the
+induction equation. Incorporating anisotropic thermal conduction requires to
+also treat parabolic terms arising from the diffusion operator. An explicit
+treatment of parabolic terms will considerably reduce the simulation time step
+due to its dependence on the square of the grid resolution ($\Delta x$) for
+stability. Although an implicit scheme relaxes the constraint on stability, it
+is difficult to distribute efficiently on a parallel architecture. Treating
+parabolic terms with accelerated super-time stepping (STS) methods has been
+discussed in literature but these methods suffer from poor accuracy (first
+order in time) and also have difficult-to-choose tuneable stability parameters.
+In this work we highlight a second order (in time) Runge Kutta Legendre (RKL)
+scheme (first described by Meyer et. al. 2012) that is robust, fast and
+accurate in treating parabolic terms alongside the hyperbolic conversation
+laws. We demonstrate its superiority over the first order super time stepping
+schemes with standard tests and astrophysical applications. We also show that
+explicit conduction is particularly robust in handling saturated thermal
+conduction. Parallel scaling of explicit conduction using RKL scheme is
+demonstrated up to more than $10^4$ processors.",1702.05487v2
+2017-04-18,Possible topologically non-trivial superconducting order parameter in type-II Weyl semimetal T_d-MoTe_2,"MoTe_2, with the orthorhombic T_d phase, is a new type (type-II) of Weyl
+semimetal, where the Weyl Fermions emerge at the boundary between electron and
+hole pockets. Non-saturating magnetoresistance (MR), and superconductivity were
+also observed in T_d-MoTe_2. Understanding the superconductivity in T_d-MoTe_2,
+which was proposed to be topologically non-trivial, is of eminent interest.
+Here, we report high-pressure (p_max = 1.3 GPa) muon spin rotation experiments
+on the temperature-dependent magnetic penetration depth in T_d-MoTe_2. A
+substantial increase of the superfluid density n_s/m^* and a linear scaling
+with T_c is observed under pressure. Moreover, the superconducting order
+parameter in T_d-MoTe_2 is determined to be two gap (s+s)-wave symmetric. We
+also excluded time reversal symmetry breaking in the SC state with sensitive
+zero-field ${\mu}$SR experiments. Considering the previous report
+\cite{Balicas1} on the strong suppression of T_c in T_d-MoTe_2 by disorder, we
+suggest that s^{+-} (topological order parameter) state is more likely to be
+realized in MoTe_2 than the s^{++} (trivial) state. Should s^{+-} be the SC gap
+symmetry, the T_d-MoTe_2 is, to our knowledge, the first known example of a
+time reversal invariant topological (Weyl) superconductor.",1704.05185v1
+2017-04-24,Mass-Imbalanced Ionic Hubbard Chain,"A repulsive Hubbard model with both spin-asymmetric hopping (${t_\uparrow\neq
+t_\downarrow}$) and a staggered potential (of strength $\Delta$) is studied in
+one dimension. The model is a compound of the mass-imbalanced (${t_\uparrow\neq
+t_\downarrow}$, ${\Delta=0}$) and ionic (${t_\uparrow = t_\downarrow}$,
+${\Delta>0}$) Hubbard models, and may be realized by cold atoms in engineered
+optical lattices. We use mostly mean-field theory to determine the phases and
+phase transitions in the ground state for a half-filled band (one particle per
+site). We find that a period-two modulation of the particle (or charge) density
+and an alternating spin density coexist for arbitrary Hubbard interaction
+strength, ${U\geqslant 0}$. The amplitude of the charge modulation is largest
+at ${U=0}$, decreases with increasing $U$ and tends to zero for
+${U\rightarrow\infty}$. The amplitude for spin alternation increases with $U$
+and tends to saturation for ${U\rightarrow\infty}$. Charge order dominates
+below a critical value $U_c$, whereas magnetic order dominates above. The
+mean-field Hamiltonian has two gap parameters, $\Delta_\uparrow$ and
+$\Delta_\downarrow$, which have to be determined self-consistently. For
+${U<U_c}$ both parameters are positive, for ${U>U_c}$ they have different
+signs, and for ${U=U_c}$ one gap parameter jumps from a positive to a negative
+value. The weakly first-order phase transition at $U_c$ can be interpreted in
+terms of an avoided criticality (or metallicity). The system is reluctant to
+restore a symmetry that has been broken explicitly.",1704.07459v2
+2017-05-23,Temperature independent band structure of WTe2 as observed from ARPES,"Extremely large magnetoresistance (XMR), observed in transition metal
+dichalcogendies, WTe$_2$, has attracted recently a great deal of research
+interests as it shows no sign of saturation up to the magnetic field as high as
+60 T, in addition to the presence of type-II Weyl fermions. Currently, there
+has been a lot of discussion on the role of band structure changes on the
+temperature dependent XMR in this compound. In this contribution, we study the
+band structure of WTe$_2$ using angle-resolved photoemission spectroscopy
+(ARPES) and first-principle calculations to demonstrate that the temperature
+dependent band structure has no substantial effect on the temperature dependent
+XMR as our measurements do not show band structure changes on increasing the
+sample temperature between 20 and 130 K. We further observe an electronlike
+surface state, dispersing in such a way that it connects the top of bulk
+holelike band to the bottom of bulk electronlike band. Interestingly, similar
+to bulk states, the surface state is also mostly intact with the sample
+temperature. Our results provide invaluable information in shaping the
+mechanism of temperature dependent XMR in WTe$_2$.",1705.09146v2
+2017-06-28,Instabilities of a U(1) quantum spin liquid in disordered non-Kramers pyrochlores,"Quantum spin liquids (QSLs) are exotic phases of matter exhibiting long-range
+entanglement and supporting emergent gauge fields. A vigorous search for
+experimental realizations of these states has identified several materials with
+properties hinting at QSL physics. A key issue in understanding these QSL
+candidates is often the interplay of weak disorder of the crystal structure
+with the spin liquid state. It has recently been pointed out that in at least
+one important class of candidate QSLs - pyrochlore magnets based on non-Kramers
+ions such as Pr$^{3+}$ or Tb$^{3+}$- structural disorder can actually promote a
+$U(1)$ QSL ground state. Here we set this proposal on a quantitative footing by
+analyzing the stability of the QSL state in the minimal model for these
+systems: a random transverse field Ising model. We consider two kinds of
+instability, which are relevant in different limits of the phase diagram:
+condensation of spinons and confinement of the $U(1)$ gauge fields. Having
+obtained stability bounds on the QSL state we apply our results directly to the
+disordered candidate QSL Pr$_2$Zr$_2$O$_7$. We find that the available data for
+currently studied samples of Pr$_2$Zr$_2$O$_7$ is most consistent with it a
+ground state outside the spin liquid regime, in a paramagnetic phase with
+quadrupole moments near saturation due to the influence of structural disorder.",1706.09238v2
+2017-07-10,Two-temperature momentum distribution in a Thulium magneto-optical trap,"Second-stage laser cooling of thulium atoms at the 530.7 nm transition with a
+natural linewidth of 350 kHz offers an interesting possibility to study
+different regimes of a magneto-optical trap (MOT). The intermediate value of
+the spectral linewidth of the cooling transition allows the observation of
+three distinct regimes depending on intensity and detuning of the cooling
+beams. Namely, the ""bowl-shaped"" regime when light pressure force competes with
+gravity, the ""double structure"" regime with interplay between Doppler and
+polarization-gradient (sub-Doppler) cooling, and the ""symmetric"" regime when
+Doppler cooling dominates over sub-Doppler cooling and gravity. The
+polarization-gradient cooling manifests itself by a two-temperature momentum
+distribution of atoms resulting in a double-structure of the spatial MOT
+profile consisting of a cold central fraction surrounded by a hot halo. We
+studied the ""double structure"" regime at different saturation parameters and
+compared observations with calculations based on semiclassical and quantum
+approaches. The quantum treatment adequately reproduces experimental results if
+the MOT magnetic field is properly taken into account.",1707.02947v3
+2017-10-09,"Finite temperature physics of $1D$ topological Kondo insulator: Stable Haldane phase, Emergent energy scale and Beyond","We have studied the one-dimensional $p$-wave periodic Anderson model at
+finite temperature with the help of the numerically exact determinant quantum
+Monte Carlo simulation. It is found that the topological Haldane phase
+established for ground-state is still stable against small thermal fluctuation
+and its characteristic edge magnetization develops at low temperature.
+Moreover, the saturated low-$T$ spin structure factor and the $\frac{1}{T}$-law
+of susceptibility are useful to detect the free edge spin moment, which may be
+relevant for experimental explorations. We have also comparatively studied the
+conventional $s$-wave periodic Anderson model, which helps us identify an
+emergent energy scale $T_{cr}$. $T_{cr}$ signals a crossover into interesting
+low-$T$ regime and seems to be the expected Ruderman-Kittel-Kasuya-Yosida
+(RKKY) coupling. Finally, the collective Kondo screening effect has been
+examined and it is heavily reduced at boundary, which may give a fruitful
+playground for novel physics beyond the well-established Haldane state and
+topological band insulators.",1710.02978v3
+2017-10-31,Spin susceptibility of charge ordered YBa2Cu3Oy across the upper critical field,"The value of the upper critical field Hc2, a fundamental characteristic of
+the superconducting state, has been subject to strong controversy in high-Tc
+copper-oxides. Since the issue has been tackled almost exclusively by
+macroscopic techniques so far, there is a clear need for local-probe
+measurements. Here, we use 17O NMR to measure the spin susceptibility
+$\chi_{spin}$ of the CuO2 planes at low temperature in charge ordered
+YBa2Cu3Oy. We find that $\chi_{spin}$ increases (most likely linearly) with
+magnetic field H and saturates above field values ranging from 20 to 40 T. This
+result is consistent with Hc2 values claimed by G. Grissonnanche et al. [Nat.
+Commun. 5, 3280 (2014)] and with the interpretation that the
+charge-density-wave (CDW) reduces Hc2 in underdoped YBa2Cu3Oy. Furthermore, the
+absence of marked deviation in $\chi_{spin}(H)$ at the onset of long-range CDW
+order indicates that this Hc2 reduction and the Fermi-surface reconstruction
+are primarily rooted in the short-range CDW order already present in zero
+field, not in the field-induced long-range CDWorder. Above Hc2, the relatively
+low values of $\chi_{spin}$ at T=2 K show that the pseudogap is a ground-state
+property, independent of the superconducting gap.",1711.00109v1
+2017-11-28,Nodal multigap superconductivity in KCa$_2$Fe$_4$As$_4$F$_2$,"We find evidence that the newly discovered Fe-based superconductor
+KCa$_2$Fe$_4$As$_4$F$_2$ ($T_c~=~33.36(7)$~K) displays multigap
+superconductivity with line nodes. Transverse field muon spin rotation
+($\mu$SR) measurements show that the temperature dependence of the superfluid
+density does not have the expected behavior of a fully-gapped superconductor,
+due to the lack of saturation at low temperatures. Moreover, the data cannot be
+well fitted using either single band models or a multiband $s$-wave model, yet
+are well described by two-gap models with line nodes on either one or both of
+the gaps. Meanwhile the zero-field $\mu$SR results indicate a lack of time
+reversal symmetry breaking in the superconducting state, but suggest the
+presence of magnetic fluctuations. These results demonstrate a different route
+for realizing nodal superconductivity in iron-based superconductors. Here the
+gap structure is drastically altered upon replacing one of the spacer layers,
+indicating the need to understand how the pairing state is tuned by changes of
+the asymmetry between the pnictogens located either side of the Fe planes.",1711.10139v2
+2017-12-19,Li doping kagome spin liquid compounds,"Herbertsmithite and Zn-doped barlowite are two compounds for experimental
+realization of twodimensional gapped kagome spin liquid. Theoretically, it has
+been proposed that charge doping a quantum spin liquid gives rise to exotic
+metallic states, such as high-temperature superconductivity. However, one
+recent experiment about herbertsmithite with successful Li-doping shows
+surprisingly the insulating state even under the heavy doped scenario, which
+can hardly be explained by many-body physics. Using first-principles
+calculation, we performed a comprehensive study about the Li intercalated
+doping effect of these two compounds. For the Li-doped herbertsmithite, we
+identified the optimized Li position at the Cl-(OH)$_3$-Cl pentahedron site
+instead of previously speculated Cl-(OH)$_3$ tetrahedral site. With the
+increase of Li doping concentration, the saturation magnetization decreases
+linearly due to the charge transfer from Li to Cu ions. Moreover, we found that
+Li forms chemical bonds with the nearby (OH)$^-$ and Cl$^-$ ions, which lowers
+the surrounding chemical potential and traps the electron, as evidenced by the
+localized charge distribution, explaining the insulating behavior measured
+experimentally. Though with different structure from herbertsmithite, Zn-doped
+Barlowite shows the same features upon Li doping. We conclude that Li doping
+this family of kagome spin liquid cannot realize exotic metallic states, other
+methods should be further explored, such as element substitution with different
+valence electrons.",1712.06791v2
+2017-12-19,Anomalous metals -- failed superconductors,"The observation of metallic ground states in a variety of two-dimensional
+electronic systems poses a fundamental challenge for the theory of electron
+fluids. Here, we analyze evidence for the existence of a regime, which we call
+the ""anomalous metal regime,"" in diverse 2D superconducting systems driven
+through a quantum superconductor to metal transition (QSMT) by tuning physical
+parameters such as the magnetic field, the gate voltage in the case of systems
+with a MOSFET geometry, or the degree of disorder. The principal
+phenomenological observation is that in the anomalous metal, as a function of
+decreasing temperature, the resistivity first drops as if the system were
+approaching a superconducting ground state, but then saturates at low
+temperatures to a value that can be orders of magnitude smaller than the Drude
+value. The anomalous metal also shows a giant positive magneto-resistance.
+Thus, it behaves as if it were a ""failed superconductor."" This behavior is
+observed in a broad range of parameters. We moreover exhibit, by theoretical
+solution of a model of superconducting grains embedded in a metallic matrix,
+that as a matter of principle such anomalous metallic behavior can occur in the
+neighborhood of a QSMT. However, we also argue that the robustness and
+ubiquitous nature of the observed phenomena are difficult to reconcile with any
+existing theoretical treatment, and speculate about the character of a more
+fundamental theoretical framework.",1712.07215v1
+2018-01-07,Graphene $n$-$p$ junctions in the Quantum Hall regime: numerical study of incoherent scattering effects,"We investigate electronic transport through a graphene $n$-$p$ junction in
+the quantum Hall effect regime at high perpendicular magnetic field, when the
+filling factors in the $n$-doped and $p$-doped regions are fixed to 2 and -2
+respectively. We compute numerically the conductance $G$, the noise $Q$ and the
+Fano factor $F$ of the junction when inelastic effects are included along the
+interface in a phenomenological way, by means of fictitious voltage probes.
+Using a scaling approach, we extract the system coherence length $L_\phi$ and
+describe the full crossover between the coherent limit ($W\ll L_\phi$) and the
+incoherent limit ($W\gg L_\phi$), $W$ being the interface length. While $G$
+saturates at the value $e^2/h$ in the incoherent regime, $Q$ and $F$ are found
+to vanish exponentially for large length $W$. Corrections due to disorder are
+also investigated. Our results are finally compared to available experimental
+data.",1801.02235v2
+2018-01-09,Superfluid drag in the two-component Bose-Hubbard model,"In multicomponent superfluids and superconductors, co- and counter-flows of
+components have in general different properties. It was discussed in 1975 by
+Andreev and Bashkin, in the context of He$^3$/He$^4$ superfluid mixtures, that
+inter-particle interactions produce a dissipationless drag. The drag can be
+understood as a superflow of one component induced by phase gradients of the
+other component. Importantly the drag can be both positive (entrainment) and
+negative (counter-flow). The effect is known to be of crucial importance for
+many properties of diverse physical systems ranging from the dynamics of
+neutron stars, rotational responses of Bose mixtures of ultra-cold atoms to
+magnetic responses of multicomponent superconductors. Although there exists a
+substantial literature that includes the drag interaction phenomenologically,
+much fewer regimes are covered by quantitative studies of the microscopic
+origin of the drag and its dependence on microscopic parameters. Here we study
+the microscopic origin and strength of the drag interaction in a quantum system
+of two-component bosons on a lattice with short-range interaction. By
+performing quantum Monte-Carlo simulations of a two-component Bose-Hubbard
+model we obtain dependencies of the drag strength on the boson-boson
+interactions and properties of the optical lattice. Of particular interest are
+the strongly-correlated regimes where the ratio of co-flow and counter-flow
+superfluid stiffnesses can diverge, corresponding to the case of saturated
+drag.",1801.03052v1
+2018-03-01,Turbulence Closure for Mixing Length Theories,"We present an approach to turbulence closure based on mixing length theory
+with three-dimensional fluctuations against a two-dimensional background. This
+model is intended to be rapidly computable for implementation in stellar
+evolution software and to capture a wide range of relevant phenomena with just
+a single free parameter, namely the mixing length. We incorporate magnetic,
+rotational, baroclinic and buoyancy effects exactly within the formalism of
+linear growth theories with nonlinear decay. We treat differential rotation
+effects perturbatively in the corotating frame using a novel controlled
+approximation which matches the time evolution of the reference frame to
+arbitrary order. We then implement this model in an efficient open source code
+and discuss the resulting turbulent stresses and transport coefficients. We
+demonstrate that this model exhibits convective, baroclinic and shear
+instabilities as well as the magnetorotational instability (MRI). It also
+exhibits non-linear saturation behaviour, and we use this to extract the
+asymptotic scaling of various transport coefficients in physically interesting
+limits.",1803.00579v3
+2018-03-10,Observation of Chiral character deep in the topological insulating regime in Bi$_{1-x}$Sb$_x$,"Bi$_{1-x}$Sb$_x$ is a topological insulator (TI) for $x \approx 0.03
+$--$0.20$. Close to the Topological phase transition at $x = 0.03$, a magnetic
+field induced Weyl semi-metal (WSM) state is stabilized due to the splitting of
+the Dirac cone into two Weyl cones of opposite chirality. A signature of the
+Weyl state is the observation of a Chiral anomaly [negative longitudnal
+magnetoresistance (LMR)] and a violation of the Ohm's law (non-linear $I-V$).
+We report the unexpected discovery of a Chiral anomaly in the whole range ($x =
+0.032, 0.072, 0.16$) of the TI state. This points to a field induced WSM state
+in an extended $x$ range and not just near the topological transition at $x =
+0.03$. Surprisingly, the strongest Weyl phase is found at $x = 0.16$ with a
+non-saturating negative LMR much larger than observed for $x = 0.03$. The
+negative LMR vanishes rapidly with increasing angle between $B$ and $I$.
+Additionally, non-linear $I$--$V$ is found for $x = 0.16$ indicating a
+violation of Ohm's law. This unexpected observation of a strong Weyl state in
+the whole TI regime in Bi$_{1-x}$Sb$_x$ points to a gap in our understanding of
+the detailed electronic structure evolution in this alloy system.",1803.03825v1
+2018-04-09,Boiling crisis dynamics: low gravity experiments at high pressure,"To understand the boiling crisis mechanism, one can take advantage of the
+slowing down of boiling at high pressures, in the close vicinity of the
+liquid-vapor critical point of the given fluid. To preserve conventional bubble
+geometry, such experiments need to be carried out in low gravity. We report
+here two kinds of saturated boiling experiments. First we discuss the spatial
+experiments with SF$_6$ at 46$^\circ$ C. Next we address two ground-based
+experiments under magnetic gravity compensation with H$_2$ at 33 K. We compare
+both kinds of experiments and show their complementarity. The dry spots under
+vapor bubbles are visualized by using transparent heaters made with metal oxide
+films. We evidence two regimes of the dry spots growth: the regime of circular
+dry spots and the regime of chain coalescence of dry spots that immediately
+precedes the heater dryout. A recent H$_2$ experiment is shown to bridge the
+gap between the near-critical and low pressure boiling experiments.",1804.03050v1
+2018-04-18,Equation of state and optical properties of shock-compressed C:H:N:O molecular mixtures,"Water, ethanol, and ammonia are the key components of the mantles of Uranus
+and Neptune. To improve structure and evolution models and give an explanation
+of the magnetic fields and luminosities of the icy giants, those components
+need to be characterised at planetary conditions (some Mbar and a few $10^3$
+K). Those conditions are typical of the Warm Dense Matter regime, which
+exhibits a rich phase diagram, with the coexistence of many states of matter
+and a large variety of chemical processes. H$_2$O, C:H:O, and C:H:N:O mixtures
+have been compressed up to 2.8 Mbar along the principal Hugoniot using
+laser-driven decaying shocks. The experiments were performed at the GEKKO XII
+and LULI 2000 laser facilities using standard optical diagnostics (Doppler
+velocimetry and pyrometry) to characterise equation of state and optical
+reflectivity of the shocked states. The results show that H$_2$O and the
+C:H:N:O mixture share the same equation of state with a density scaling, while
+the reflectivity behaves differently by what concerns both the onset pressures
+and the saturation values. The reflectivity measurement at two frequencies
+allows to estimate the conductivity and the complex refractive index using a
+Drude model.",1804.06595v1
+2018-04-21,Experimental Signatures of Spin Superfluid Ground State in Canted Antiferromagnet Cr2O3 via Nonlocal Spin Transport,"Spin superfluid is a novel emerging quantum matter arising from the
+Bose-Einstein condensate (BEC) of spin-1 bosons. We demonstrate the spin
+superfluid ground state in canted antiferromagnetic Cr2O3 thin film at low
+temperatures via nonlocal spin transport. A large enhancement of the nonlocal
+spin signal is observed below ~ 20 K, and it saturates from ~ 5 K down to 2 K.
+We show that the spins can propagate over very long distances (~ 20 micro
+meters) in such spin superfluid ground state and the nonlocal spin signal
+decreases very slowly as the spacing increases with an inverse relationship,
+which is consistent with theoretical prediction. Furthermore, spin
+superfluidity has been investigated in the canted antiferromagnetic phase of
+the (11-20)-oriented Cr2O3 film, where the magnetic field dependence of the
+associated critical temperature follows a two-thirds power law near the
+critical point. The experimental demonstration of the spin superfluid ground
+state in canted antiferromagnet will be extremely important for the fundamental
+physics on the BEC of spin-1 bosons and paves the way for future spin
+supercurrent devices, such as spin-Josephson junctions.",1804.07966v1
+2018-05-09,Dynamic spin-lattice coupling and nematic fluctuations in NaFeAs,"We use inelastic neutron scattering to study acoustic phonons and spin
+excitations in single crystals of NaFeAs, a parent compound of iron pnictide
+superconductors. NaFeAs exhibits a tetragonal-to-orthorhombic structural
+transition at $T_s\approx 58$ K and a collinear antiferromagnetic (AF) order at
+$T_N\approx 45$ K. While longitudinal and out-of-plane transverse acoustic
+phonons behave as expected, the in-plane transverse acoustic phonons reveal
+considerable softening on cooling to $T_s$, and then harden on approaching
+$T_N$ before saturating below $T_N$. In addition, we find that spin-spin
+correlation lengths of low-energy magnetic excitations within the FeAs layer
+and along the $c$-axis increase dramatically below $T_s$, and show weak anomaly
+across $T_N$. These results suggest that the electronic nematic phase present
+in the paramagnetic tetragonal phase is closely associated with dynamic
+spin-lattice coupling, possibly arising from the one-phonon-two-magnon
+mechanism.",1805.03493v1
+2018-06-18,Renormalization of quantum dot $g$-factor in superconducting Rashba nanowires,"We study analytically and numerically the renormalization of the $g$-factor
+in semiconducting Rashba nanowires (NWs), consisting of a normal and
+superconducting section. If the potential barrier between the sections is high,
+a quantum dot (QD) is formed in the normal section. For harmonic (hard-wall)
+confinement, the effective $g$-factor of all QD levels is suppressed
+exponentially (power-law) in the product of the spin-orbit interaction (SOI)
+wavevector and the QD length. If the barrier between the two sections is
+removed, the $g$-factor of the emerging Andreev bound states is suppressed less
+strongly. In the strong SOI regime and if the chemical potential is tuned to
+the SOI energy in both sections, the $g$-factor saturates to a universal
+constant. Remarkably, the effective $g$-factor shows a pronounced peak at the
+SOI energy as function of the chemical potentials. In addition, if the SOI is
+uniform, the $g$-factor renormalization as a function of the chemical potential
+is given by a universal dependence which is independent of the QD size. This
+prediction provides a powerful tool to determine experimentally whether the SOI
+in the whole NW is uniform and, moreover, gives direct access to the SOI
+strengths of the NW via $g$-factor measurements. In addition, it allows one to
+find the optimum position of the chemical potential for bringing the NW into
+the topological phase at large magnetic fields.",1806.06842v1
+2018-11-08,Light-induced anomalous Hall effect in graphene,"Many striking non-equilibrium phenomena have been discovered or predicted in
+optically-driven quantum solids, ranging from light-induced superconductivity
+to Floquet-engineered topological phases. These effects are expected to lead to
+dramatic changes in electrical transport, but can only be comprehensively
+characterized or functionalized with a direct interface to electrical devices
+that operate at ultrafast speeds. Here, we make use of laser-triggered
+photoconductive switches to measure the ultrafast transport properties of
+monolayer graphene, driven by a mid-infrared femtosecond pulse of circularly
+polarized light. The goal of this experiment is to probe the transport
+signatures of a predicted light-induced topological band structure in graphene,
+similar to the one originally proposed by Haldane. We report the observation of
+an anomalous Hall effect in the absence of an applied magnetic field. We also
+extract quantitative properties of the non-equilibrium state. The dependence of
+the effect on a gate potential used to tune the Fermi level reveals multiple
+features that reflect the effective band structure expected from Floquet
+theory. This includes a ~60 meV wide conductance plateau centered at the Dirac
+point, where a gap of approximately equal magnitude is expected to open. We
+also find that when the Fermi level lies within this plateau, the estimated
+anomalous Hall conductance saturates around ~1.8$\pm$0.4 e$^2$/h.",1811.03522v2
+2018-11-29,Application of an extended van der Pauw method to anisotropic magnetoresistance measurements of ferromagnetic films,"We demonstrate anisotropic resistivity measurements using the extended van
+der Pauw (vdP) method in ferromagnetic Ni80Fe20 (Py) films. We apply it to
+measure anisotropic magnetoresistance (AMR) and compare the results of the vdP
+method with the more conventional Hall-bar method along the hard and easy axis
+of the film and show that the vdP method gives more reliable AMR result. For
+instance, the AMR result along the hard and easy axis of the film are in close
+agreement. Further, we applied the vdP method to study AMR in a series of Py
+films with thicknesses ranging between 10-250 nm. The films were grown by
+sputtering deposition at an angle with respect to the substrate normal and with
+an in-situ magnetic field, both conditions assisting in the definition of
+in-plane uniaxial anisotropy. The microstructure of Py films was characterized
+using X-ray reflectivity, diffraction and polar mapping of (111) planes. We
+detected no off-normal texture and negligible surface roughness, which
+indicates that self-shadowing is not dominating in our growth. Yet the films
+have well defined uniaxial anisotropy. Abrupt changes in the average
+resistivity vs. film thickness were observed, which cannot be explained by the
+models accounting for the thickness and grain size but strongly correlate with
+the changes in (111) texture in the films. We compared our results with the
+literature and show that independent of growth method, substrate and deposition
+temperature, the AMR value presents a saturation behavior with thickness at
+about 100 nm.",1811.12029v1
+2018-12-23,Constraining Theories of Polarized SiO Maser Transport: Multi-Epoch Analysis of a $π/2$ Electric Vector Rotation Feature,"The detailed polarization mechanisms of SiO masers originating from the near
+circum\-stellar environment of Asymptotic Giant Branch stars are not yet
+definitively known. Prevailing theories are broadly classified as either Zeeman
+or non-Zeeman in origin, the latter including effects such as anisotropic
+pumping or anisotropic resonant scattering. The predicted behavior of the
+linear and circular polarization fractions and electric vector position angle
+vary by theory. In particular, individual maser features that exhibit a
+rotation in linear polarization of $\sim \pi/2$ as a function of frequency over
+their extent can be utilized as a test of several maser polarization transport
+theories. In this paper, we analyze one SiO ($\nu=1$, $J=1-0$) maser feature
+toward the Mira variable, TX Cam that exhibits this internal polarization
+rotation and persists across five epochs (spanning $\sim3$ months). We compare
+our results to the predictions by several maser polarization theories and find
+that the linear polarization across the feature is consistent with a geometric
+effect for a saturated maser originating when the angle between the projected
+magnetic field and the line of sight ($\theta$) crosses the Van Vleck angle
+$\theta_F \sim 55^{\circ}$. However, the electric vector position angle (EVPA)
+exhibits a smooth rotation across the spatial extent of the feature rather than
+the expected abrupt $\pi/2$ flip. We discuss possible explanations for this
+discrepancy and alternative theories. Circular polarization across the feature
+is also analyzed and it is the most accurately described by Zeeman effects
+giving rise to a circular polarization fraction of the form $m_c$ is
+approximately proportional to $\cos \theta$.",1812.09631v1
+2018-12-29,Single-layer tensor network study of the Heisenberg model with chiral interactions on a kagome lattice,"We study the antiferromagnetic kagome Heisenberg model with additional
+scalar-chiral interaction by using the infinite projected entangled-pair state
+(iPEPS) ansatz. We discuss in detail the implementation of optimization
+algorithm in the framework of the single-layer tensor network based on the
+corner-transfer matrix technique. Our benchmark based on the full-update
+algorithm shows that the single-layer algorithm is stable, which leads to the
+same level of accuracy as the double-layer ansatz but with much less
+computation time. We further apply this algorithm to study the nature of the
+kagome Heisenberg model with a scalar-chiral interaction by computing the bond
+dimension scaling of magnetization, bond energy difference, chiral order
+parameter and correlation length. In particular, we find that for strong chiral
+coupling the correlation length, which is extracted from the transfer matrix,
+saturates to a finite value for large bond dimension, representing a gapped
+spin-liquid state. Further comparison with density matrix renormalization group
+results supports that our iPEPS faithfully represents the time-reversal
+symmetry breaking chiral state. Our iPEPS simulation results shed new light on
+constructing PEPS for describing gapped chiral topological states.",1812.11436v3
+2019-01-28,Super-Eddington accretion onto the Galactic ultraluminous X-ray pulsar Swift J0243.6+6124,"We report on the spectral behavior of the first Galactic ultraluminous X-ray
+pulsar Swift J0243.6+6124 with NuSTAR observations during its 2017-2018
+outburst. At sub-Eddington levels, the source spectrum is characterized by
+three emission components, respectively from the accretion column, the hot
+spot, and a broad iron line emission region. When the source is above the
+Eddington limit, the hot spot temperature increases and the spectrum features
+two more blackbody components. One blackbody component has a radius of 10-20 km
+and is likely originated from the top of the accretion column. The other one
+saturates at a blackbody luminosity of (1 - 2)*10^38 erg/s, coincident with the
+Eddington limit of a neutron star. This is well consistent with the scenario
+that super-Eddington accretion onto compact objects will power optically-thick
+outflows and indicates an accretion rate 60-80 times the critical value. This
+suggests that super-Eddington accretion onto magnetized systems can also power
+massive winds. At super-Eddington levels, the iron line becomes more
+significant and blueshifted, and is argued to be associated with the ultrafast
+wind in the central funnel or jets. This source, if located in external
+galaxies, will appear like other ultraluminous pulsars.",1901.09485v1
+2019-02-16,Bulk Fermi surface of the type-II Weyl semimetal candidate NbIrTe$_{4}$,"Recently, a new group of layered transition-metal tetra-chalcogenides were
+proposed, via first principles calculations, to correspond to a new family of
+Weyl type-II semimetals with promising topological properties in the bulk as
+well as in the monolayer limit. In this article, we present measurements of the
+Shubnikov-de Haas (SdH) and de Haas-van Alphen effects under high magnetic
+fields for the type-II Weyl semimetallic candidate NbIrTe$_{4}$. We find that
+the angular dependence of the observed Fermi surface extremal cross-sectional
+areas agree well with our DFT calculations supporting the existence of Weyl
+type-II points in this material. Although we observe a large and non-saturating
+magnetoresistivity in NbIrTe$_{4}$ under fields all the way up to 35 T,
+Hall-effect measurements indicate that NbIrTe$_{4}$ is not a compensated
+semimetal. The transverse magnetoresistivity displays a four-fold angular
+dependence akin to the so-called butterfly magnetoresistivity observed in nodal
+line semimetals. However, we conclude that its field and this unconventional
+angular-dependence are governed by the topography of the Fermi-surface and the
+resulting anisotropy in effective masses and in carrier mobilities.",1902.06159v3
+2019-03-08,Josephson Field-Effect Transistors Based on All-Metallic Al/Cu/Al Proximity Nanojunctions,"We demonstrate the first \textit{all-metallic} mesoscopic
+superconductor-normal metal-superconductor (SNS) field-effect controlled
+Josephson transistors (SNS-FETs) and show their full characterization from the
+critical temperature $T_c$ down to 50 mK in the presence of both electric and
+magnetic field. The ability of a static electric field -applied by mean of a
+lateral gate electrode- to suppress the critical current $I_s$ in a
+proximity-induced superconductor is proven for both positive and negative gate
+voltage values. $I_s$ suppression reached typically about one third of its
+initial value, saturating at high gate voltages. The transconductance of our
+SNS-FETs obtains values as high as 100 nA/V at 100 mK. On the fundamental
+physics side, our results suggest that the mechanism at the basis of the
+observed phenomenon is quite general and does not rely on the existence of a
+true pairing potential, but rather the presence of superconducting correlations
+is enough for the effect to occur. On the technological side, our findings
+widen the family of materials available for the implementation of all-metallic
+field-effect transistors to \textit{synthetic} proximity-induced
+superconductors.",1903.03435v2
+2019-04-22,Highly anisotropic interlayer magnetoresistance in ZrSiS nodal-line Dirac semimetal,"We instigate the angle-dependent magnetoresistance (AMR) of the layered
+nodal-line Dirac semimetal ZrSiS for the in-plane and out-of-plane current
+directions. This material has recently revealed an intriguing butterfly-shaped
+in-plane AMR that is not well understood. Our measurements of the polar
+out-of-plane AMR show a surprisingly different response with a pronounced
+cusp-like feature. The maximum of the cusp-like anisotropy is reached when the
+magnetic field is oriented in the $a$-$b$ plane. Moreover, the AMR for the
+azimuthal out-of-plane current direction exhibits a very strong four-fold
+$a$-$b$ plane anisotropy. Combining the Fermi surfaces calculated from first
+principles with the Boltzmann's semiclassical transport theory we reproduce and
+explain all the prominent features of the unusual behavior of the in-plane and
+out-of-plane AMR. We are also able to clarify the origin of the strong
+non-saturating transverse magnetoresistance as an effect of imperfect
+charge-carrier compensation and open orbits. Finally, by combining our
+theoretical model and experimental data we estimate the average relaxation time
+of $2.6\times10^{-14}$~s and the mean free path of $15$~nm at 1.8~K in our
+samples of ZrSiS.",1904.09933v2
+2019-04-29,Type-II Ising superconductivity and anomalous metallic state in macro-size ambient-stable ultrathin crystalline films,"Recent emergence of two-dimensional (2D) crystalline superconductors has
+provided a promising platform to investigate novel quantum physics and
+potential applications. To reveal essential quantum phenomena therein, ultralow
+temperature transport investigation on high quality ultrathin superconducting
+films is critically required, although it has been quite challenging
+experimentally. Here we report a systematic transport study on the ultrathin
+crystalline PdTe2 films grown by molecular beam epitaxy (MBE). Interestingly, a
+new type of Ising superconductivity in 2D centrosymmetric materials is revealed
+by the detection of large in-plane critical field more than 7 times Pauli
+limit. Remarkably, in perpendicular magnetic field, we provide solid evidence
+of anomalous metallic state characterized by the resistance saturation at low
+temperatures with high quality filters. The robust superconductivity with
+intriguing quantum phenomena in the macro-size ambient-stable ultrathin PdTe2
+films remains almost the same for 20 months, showing great potentials in
+electronic and spintronic applications.",1904.12719v2
+2019-05-03,Evidence of quantum vortex fluid in the mixed state of a very weakly pinned a-MoGe thin film,"Quantum fluids refer to a class of systems that remain in fluid state down to
+absolute zero temperature. In this letter, using a combination of
+magnetotransport and scanning tunneling spectroscopy down to 300 mK, we show
+that vortices in a very weakly pinned a-MoGe thin film can form a quantum
+vortex fluid. Under the application of a magnetic field perpendicular to the
+plane of the film, the vortex state transforms from a vortex solid to a hexatic
+vortex fluid and eventually to an isotropic vortex liquid. The fact that the
+two latter states remain fluid down to absolute zero temperature is evidenced
+from the electrical resistance which saturates to a finite value at low
+temperatures. Furthermore, scanning tunneling spectroscopy measurements reveal
+a soft gap at the center of each vortex, which arises from large zero point
+fluctuation of vortices.",1905.01045v4
+2019-08-27,Contribution of the chiral vortical effect to the evolution of the hypermagnetic field and the matter-antimatter asymmetry in the early Universe,"In this paper, we study the contribution of the chiral vortical effect, in
+addition to that of the chiral magnetic effect, to the evolution of the
+hypermagnetic field and the matter-antimatter asymmetry in the symmetric phase
+of the early Universe in the temperature range 100GeV < T < 10TeV. We choose a
+fully helical Chern-Simons wave configuration for the velocity and the
+hypermagnetic vector potential fields. The latter makes the plasma force-free
+in the absence of viscosity. We show that the most pronounced effect of the
+chiral vorticity is the production and initial growth of the hypermagnetic
+field. In particular, we show that in the presence of a non-zero matter
+asymmetry, the hypermagnetic field can grow from zero initial value only in the
+presence of a non-zero vorticity field. Moreover, we show that larger initial
+growths not only result in larger maximum values of the hypermagnetic field,
+but also cause the saturation of the hypermagnetic field and the conversion of
+the lepton-baryon asymmetry to occur more quickly, i.e., at a higher
+temperature. We show that the damping of the vorticity due to the presence of
+viscosity, which typically occurs extremely rapidly, does not significantly
+affect the evolution.",1908.10105v2
+2019-10-23,"HFQPOs and discoseismic mode excitation in eccentric, relativistic discs. I. Hydrodynamic simulations","High-frequency quasi-periodic oscillations (HFQPOs) observed in the emission
+of black-hole X-ray binary systems promise insight into strongly curved
+spacetime. `Discoseismic' oscillations with frequencies set by the intrinsic
+properties of the central black hole, in particular `trapped inertial waves'
+(r-modes), offer an attractive explanation for HFQPOs. To produce an observable
+signature, however, such oscillations must be excited to sufficiently large
+amplitudes. Turbulence driven by the magnetorotational instability (MRI) fails
+to provide the necessary amplification, but r-modes may still be excited via
+interaction with accretion disc warps or eccentricities. We present 3D global
+hydrodynamic simulations of relativistic accretion discs, which demonstrate for
+the first time the excitation of trapped inertial waves by an imposed
+eccentricity in the flow. While the r-modes' saturated state depends on the
+vertical boundary conditions used in our unstratified, cylindrical framework,
+their excitation is unambiguous in all runs with eccentricity >0.005 near the
+ISCO. These simulations provide a proof of concept, demonstrating the
+robustness of trapped inertial wave excitation in a non-magnetized context. In
+a companion paper, we explore the competition between this excitation, and
+damping by magnetohydrodynamic turbulence.",1910.10696v3
+2019-10-30,A note on the experiment parameters for the non-resonant streaming instability: competition between left and right circularly polarized modes,"A non-resonant streaming instability driven by cosmic-ray currents, also
+called Bell's instability, is proposed as a candidate for providing the
+required magnetic turbulence of efficient diffusive shock accelerations. To
+demonstrate the saturation level and mechanism of the non-resonant streaming
+instability in a laboratory environment, we attempt to develop an experiment at
+the Photo Injector Test Facility at DESY, Zeuthen site (PITZ). As an electron
+beam is used to replace the proton beam to carry the cosmic-ray current in our
+experiment, the polarization of the non-resonant streaming instability will be
+modified from the left-handed (LH) mode to the right-handed (RH) mode. The
+theoretical instability analysis shows that the growth rate of this RH
+non-resonant mode may be smaller than it of the LH resonant mode. However the
+LH resonant mode can be ignored in our experiment while the expected wavelength
+is longer than the used plasma cell. The results of PIC simulations will also
+support this contention and the occurrence of non-resonant streaming
+instability in our experiment.",1910.13756v1
+2020-01-14,Spectrum variability of the active solar-type star Xi Bootis A,"An extensive spectroscopic study on \xi Boo A (chromospherically active
+solar-type star) was conducted based on the spectra obtained in 2008 December
+though 2010 May, with an aim to detect any spectrum variability and to
+understand its physical origin. For each spectrum, the atmospheric parameters
+were spectroscopically determined based on Fe lines, and the equivalent widths
+(along with the line-broadening parameters) of selected 99 lines were measured.
+We could detect meaningful small fluctuations in the equivalent widths of
+medium-strength lines. This variation was found to correlate with the effective
+temperature (T_eff) consistently with the T-sensitivity of each line, which
+indicates that the difference in the mean temperature averaged over the disk of
+inhomogeneous condition is mainly responsible for this variability. It was also
+found that the macrobroadening widths of medium-strength lines and the
+equivalent widths dispersion of saturated lines tend to increase with the
+effective Lande factor, suggesting an influence of magnetic field. Our power
+spectrum analysis applied to the time-sequence data of V I/Fe II line-strength
+ratio and T_eff could not confirm the 6.4 d period reported by previous
+studies. We suspect that surface inhomogeneities of \xi Boo A at the time of
+our observations were not so much simple (such as single star patch) as rather
+complex (e.g., intricate aggregate of spots and faculae).",2001.04590v1
+2020-01-23,The theory of direct laser excitation of nuclear transitions,"A comprehensive theoretical study of direct laser excitation of a nuclear
+state based on the density matrix formalism is presented. The nuclear clock
+isomer $^{229\text{m}}$Th is discussed in detail, as it could allow for direct
+laser excitation using existing technology and provides the motivation for this
+work. The optical Bloch equations are derived for the simplest case of a pure
+nuclear two-level system and for the more complex cases taking into account the
+presence of magnetic sub-states, hyperfine-structure and Zeeman splitting in
+external fields. Nuclear level splitting for free atoms and ions as well as for
+nuclei in a solid-state environment is discussed individually. Based on the
+obtained equations, nuclear population transfer in the low-saturation limit is
+reviewed. Further, nuclear Rabi oscillations, power broadening and nuclear
+two-photon excitation are considered. Finally, the theory is applied to the
+special cases of $^{229\text{m}}$Th and $^{235\text{m}}$U, being the nuclear
+excited states of lowest known excitation energies. The paper aims to be a
+didactic review with many calculations given explicitly.",2001.08320v2
+2020-02-18,Signatures of dephasing by mirror-symmetry breaking in weak-antilocalization magnetoresistance across the topological transition in Pb$_{1-x}$Sn$_{x}$Se,"Many conductors, including recently studied Dirac materials, show saturation
+of coherence length on decreasing temperature. This surprising phenomenon is
+assigned to external noise, residual magnetic impurities or two-level systems
+specific to non-crystalline solids. Here, by considering the SnTe-class of
+compounds as an example, we show theoretically that breaking of mirror symmetry
+deteriorates Berry's phase quantization, leading to additional dephasing in
+weak-antilocalization magnetoresistance (WAL-MR). Our experimental studies of
+WAL-MR corroborate these theoretical expectations in (111) Pb$_{1-x}$Sn$_x$Se
+thin film with Sn contents $x$ corresponding to both topological crystalline
+insulator and topologically trivial phases. In particular, we find the
+shortening of the phase coherence length in samples with intentionally broken
+mirror symmetry. Our results indicate that the classification of quantum
+transport phenomena into universality classes should encompass, in addition to
+time-reversal and spin-rotation invariances, spatial symmetries in specific
+systems.",2002.07622v5
+2020-04-27,Anisotropy driven reversal of magnetisation in Blume-Capel ferromagnet: A Monte Carlo study,"The two dimensional Spin-1 Blume-Capel ferromagnet is studied by Monte Carlo
+simulation with Metropolis algorithm. Starting from initial ordered spin
+configuration the reversal of magnetisation is investigated in presence of a
+magnetic field ($h$) applied in the opposite direction. The variations of the
+reversal time with the strength of single site anisotropy are investigated in
+details. The exponential dependence was observed. The systematic variations of
+the mean reversal time with positive and negative anisotropy was found. The
+mean macroscopic reversal time was observed to be linearly dependent on a
+suitably defined microscopic reversal time. The saturated magnetisation $M_f$
+after the reversal was noticed to be dependent of the strength of anisotropy
+$D$. An interesting scaling relation was obtained, $|M_f| \sim
+|h|^{\beta}f(D|h|^{-\alpha})$ with the scaling function of the form $f(x)=
+\frac{1}{1+e^{(x-a)/b}}$. The temporal evolution of density of $S_i^z=0$
+(surrounded by all $S_i^z=+1$) is observed to be exponentially decaying. The
+growth of mean density of $S_i^z=-1$ has been fitted in a function
+$\rho_{-1}(t) \sim \frac{1}{a+e^{(t_c-t)/c}}$. The characteristic time shows
+$t_c \sim e^{-rD}$ and a crossover in the rate of exponential falling is
+observed at $D=1.5$. The metastable volume fraction has been found to obey the
+Avrami's law.",2004.12586v4
+2020-05-20,Sub-grid-scale effects in magnetised plasma turbulence,"In the present paper, we use a coarse-graining approach to investigate the
+nonlinear redistribution of free energy in both position and scale space for
+weakly collisional magnetised plasma turbulence. For this purpose, we use
+high-resolution numerical simulations of gyrokinetic (GK) turbulence that span
+the proton-electron range of scales, in a straight magnetic guide field
+geometry. Accounting for the averaged effect of the particles' fast gyro-motion
+on the slow plasma fluctuations, the GK approximation captures the dominant
+energy redistribution mechanisms in strongly magnetised plasma turbulence.
+Here, the GK system is coarse-grained with respect to a cut-off scale,
+separating in real space the contributions to the nonlinear interactions from
+the coarse-grid-scales and the sub-grid-scales (SGS). We concentrate on the
+analysis of nonlinear SGS effects. Not only that this allows us to investigate
+the flux of free energy across the scales, but also to now analyse its spatial
+density. We find that the net value of scale flux is an order of magnitude
+smaller than both the positive and negative flux density contributions. The
+dependence of the results on the filter type is also analysed. Moreover, we
+investigate the advection of energy in position space. This rather novel
+approach for GK turbulence can help in the development of SGS models that
+account for advective unstable structures for space and fusion plasmas, and
+with the analysis of the turbulent transport saturation.",2005.10166v2
+2020-05-26,On quasi-parallel whistler waves in the solar wind,"The recent simulations showed that the whistler heat flux instability, which
+presumably produces the most of quasi-parallel coherent whistler waves in the
+solar wind, is not efficient in regulating the electron heat conduction. In
+addition, recent spacecraft measurements indicated that some fraction of
+coherent whistler waves in the solar wind may propagate anti-parallel to the
+electron heat flux, being produced due to a perpendicular temperature
+anisotropy of suprathermal electrons. We present analysis of properties of
+parallel and anti-parallel whistler waves unstable at electron heat fluxes and
+temperature anisotropies of suprathermal electrons typical of the pristine
+solar wind. Assuming the electron population consisting of counter-streaming
+dense thermal core and tenuous suprathermal halo populations, we perform a
+linear stability analysis to demonstrate that anti-parallel whistler waves are
+expected to have smaller frequencies, wave numbers and growth rates compared to
+parallel whistler waves. The stability analysis is performed over a wide range
+of parameters of core and halo electron populations. Using the quasi-linear
+scaling relation we show that anti-parallel whistler waves saturate at
+amplitudes of one order of magnitude smaller than parallel whistler waves,
+which is at about $10^{-3}\;B_0$ in the pristine solar wind. The analysis shows
+that the presence of anti-parallel whistler waves in the pristine solar wind is
+more likely to be obscured by turbulent magnetic field fluctuations, because of
+lower frequencies and smaller amplitudes compared to parallel whistler waves.
+The presented results will be also valuable for numerical simulations of the
+electron heat flux regulation in the solar wind.",2005.12606v1
+2020-05-28,Joint Total Variation ESTATICS for Robust Multi-Parameter Mapping,"Quantitative magnetic resonance imaging (qMRI) derives tissue-specific
+parameters -- such as the apparent transverse relaxation rate R2*, the
+longitudinal relaxation rate R1 and the magnetisation transfer saturation --
+that can be compared across sites and scanners and carry important information
+about the underlying microstructure. The multi-parameter mapping (MPM) protocol
+takes advantage of multi-echo acquisitions with variable flip angles to extract
+these parameters in a clinically acceptable scan time. In this context,
+ESTATICS performs a joint loglinear fit of multiple echo series to extract R2*
+and multiple extrapolated intercepts, thereby improving robustness to motion
+and decreasing the variance of the estimators. In this paper, we extend this
+model in two ways: (1) by introducing a joint total variation (JTV) prior on
+the intercepts and decay, and (2) by deriving a nonlinear maximum \emph{a
+posteriori} estimate. We evaluated the proposed algorithm by predicting
+left-out echoes in a rich single-subject dataset. In this validation, we
+outperformed other state-of-the-art methods and additionally showed that the
+proposed approach greatly reduces the variance of the estimated maps, without
+introducing bias.",2005.14247v1
+2020-05-29,Effects of Longitudinal Short-Distance Constraints on the Hadronic Light-by-Light Contribution to the Muon $g-2$,"We present a model-independent method to estimate the effects of
+short-distance constraints (SDCs) on the hadronic light-by-light contribution
+to the muon anomalous magnetic moment $a_\mu^\text{HLbL}$. The relevant loop
+integral is evaluated using multi-parameter families of interpolation
+functions, which satisfy by construction all constraints derived from general
+principles and smoothly connect the low-energy region with those where either
+two or all three independent photon virtualities become large. In agreement
+with other recent model-based analyses, we find that the SDCs and thus the
+infinite towers of heavy intermediate states that are responsible for
+saturating them have a rather small effect on $a_\mu^\text{HLbL}$. Taking as
+input the known ground-state pseudoscalar pole contributions, we obtain that
+the longitudinal SDCs increase $a_\mu^\text{HLbL}$ by $(9.1\pm 5.0) \times
+10^{-11}$, where the isovector channel is responsible for $(2.6\pm 1.5) \times
+10^{-11}$. More precise estimates can be obtained with our method as soon as
+further accurate, model-independent information about important low-energy
+contributions from hadronic states with masses up to 1-2 GeV become available.",2006.00007v2
+2020-06-12,Horizontal shear instabilities at low Prandtl number,"Turbulent mixing in the radiative regions of stars is usually either ignored
+or crudely accounted for in most stellar evolution models. However, there is
+growing theoretical and observational evidence that such mixing is present and
+can affect various aspects of a star's life. In this work, we present a first
+attempt at quantifying mixing by horizontal shear instabilities in stars using
+Direct Numerical Simulations. The shear is driven by a body force, and rapidly
+becomes unstable. At saturation, we find that several distinct dynamical
+regimes exist, depending on the relative importance of stratification and
+thermal diffusion (viscosity can in principle also matter, but is usually
+negligible in most stellar applications). In each of the regimes identified, we
+put forward a certain number of theoretically motivated scaling laws for the
+turbulent vertical eddy scale, the typical turbulent diffusion coefficient, and
+the typical amplitude of temperature fluctuations (among other quantities).
+Based on our findings, we predict that the majority of stars should fall into
+one of two categories: high P\'eclet number stratified turbulence, and low
+P\'eclet number stratified turbulence. The latter is presented in detail in a
+related paper by Cope et al. (2020), while the former is discussed here.
+Applying our results to the best-known stellar shear layer, namely the solar
+tachocline, we find that it should lie in the high P\'eclet number stratified
+turbulence regime, and predict a substantial amount of vertical mixing for
+temperature, momentum and composition. Taken as is, the new turbulence model
+predictions are incompatible with the Spiegel & Zahn (1992) model of the solar
+tachocline. However, we also show that rotation and magnetic fields are likely
+to affect the turbulence, and need to be taken into account in future studies.",2006.07436v1
+2020-06-17,Intelligent Protection & Classification of Transients in Two-Core Symmetric Phase Angle Regulating Transformers,"This paper investigates the applicability of time and time-frequency features
+based classifiers to distinguish internal faults and other transients -
+magnetizing inrush, sympathetic inrush, external faults with current
+transformer saturation, and overexcitation - for Indirect Symmetrical Phase
+Angle Regulating Transformers (ISPAR). Then the faulty transformer unit
+(series/exciting) of the ISPAR is located, or else the transient disturbance is
+identified. An event detector detects variation in differential currents and
+registers one-cycle of 3-phase post transient samples which are used to extract
+the time and time-frequency features for training seven classifiers. Three
+different sets of features - wavelet coefficients, time-domain features, and
+combination of time and wavelet energy - obtained from exhaustive search using
+Decision Tree, random forest feature selection, and maximum Relevance Minimum
+Redundancy are used. The internal fault is detected with a balanced accuracy of
+99.9%, the faulty unit is localized with balanced accuracy of 98.7% and the
+no-fault transients are classified with balanced accuracy of 99.5%. The results
+show potential for accurate internal fault detection and localization, and
+transient identification. The proposed scheme can supervise the operation of
+existing microprocessor-based differential relays resulting in higher stability
+and dependability. The ISPAR is modeled and the transients are simulated in
+PSCAD/EMTDC by varying several parameters.",2006.09865v1
+2020-07-19,Anisotropic Neutron Stars Modelling: Constraints in Krori-Barua Spacetime,"Dense nuclear matter is expected to be anisotropic due to effects such as
+solidification, superfluidity, strong magnetic fields, hyperons,
+pion-condesation. Therefore an anisotropic neutron star core seems more
+realistic than an ideally isotropic one. We model anisotropic neutron stars
+working in the Krori-Barua (KB) ansatz without preassuming an equation of
+state. We show that the physics of general KB solutions is encapsulated in the
+compactness. Imposing physical and stability requirements yields a maximum
+allowed compactness $2GM/Rc^2 < 0.71$ for a KB-spacetime. We further input
+observational data from numerous pulsars and calculate the boundary density. We
+focus especially on data from the LIGO/Virgo collaboration as well as recent
+independent measurements of mass and radius of miilisecond pulsars with white
+dwarf companions by the Neutron Star Interior Composition Explorer (NICER). For
+these data the KB-spacetime gives the same boundary density which surprisingly
+equals the nuclear saturation density within the data precision. Since this
+value designates the boundary of a neutron core, the KB-spacetime applies
+naturally to neutron stars. For this boundary condition we calculate a maximum
+mass of 4.1 solar masses.",2007.09797v2
+2020-07-24,Bumblebee field in a Topological Framework,"A vector field coming from spontaneous Lorentz violation mechanism, namely
+Bumblebee model is analysed in a topological framework in a $(1+2)D$ Minkowski
+space-time. Taking a $(1+2)D$ nonlinear Bumblebee vector matter field dynamics
+where we include topological like Chern-Simons type terms, a vector version of
+a soliton state, or vortex was found. The Nielsen-Olesen procedure was used in
+order to derive a Lorentz-violation vector parameter which characterizes, via
+Spontaneous Symmetry Breaking mechanism, the non-trivial vacuum. We verify the
+stability of the model as much as the magnetic vortex, and noticed that the
+soliton modes with polarized direction generated can be associated with local
+anisotropy of vacuum energy. The vortex equations of motion and the asymptotic
+behaviour is presented. We have obtained that the effect of the Lorentz
+symmetry violation expressed by the a time-like Bumblebee vector field vacuum
+could be shown as kind of pulse at a fixed point $r_0$ in a limitless universe,
+or as a barrier at $r_0$ which can represent a boundary in the universe, if the
+Bumblebee vector field vacuum has space-like characteristic. We also analyse
+the spectrum via propagators where we note that the topological mass
+contributes as well to the dynamical mass poles. We obtain that the
+Chern-Simons type terms, in fact, indicates the ""speed"" of the field to
+saturate the asymptotic limit and that the vortex core can not be dimension
+zero.",2007.12675v1
+2020-07-29,The thermal-radiative wind in the neutron star low mass X-ray binary GX 13+1,"We fit the observed high ionisation X-ray absorption lines in the neutron
+star binary GX13+1 with a full simulation of a thermal-radiative wind. This
+uses a radiation hydrodynamic code coupled to Monte Carlo radiation transfer to
+compute the observed line profiles from Hydrogen and Helium-like iron and
+Nickel, including all strong K{\alpha} and K{\beta} transitions. The wind is
+very strong as this object has a very large disc and is very luminous. The
+absorption lines from Fe K{\alpha} are strongly saturated as the ion columns
+are large, so the line equivalent widths (EWs) depend sensitively on the
+velocity structure. We additionally simulate the lines including isotropic
+turbulence at the level of the azimuthal and radial velocities. We fit these
+models to the Fe xxv and xxvi absorption lines seen in the highest resolution
+Chandra third order HETGS data. These data already rule out the addition of
+turbulence at the level of the radial velocity of ~500 km/s. The velocity
+structure predicted by the thermal-radiative wind alone is a fairly good match
+to the observed profile, with an upper limit to additional turbulence at the
+level of the azimuthal velocity of ~100 km/s. This gives stringent constraints
+on any remaining contribution from magnetic acceleration.",2007.14607v1
+2020-07-30,Model-driven reconstruction with phase-constrained highly-oversampled MRI,"The Nyquist-Shannon theorem states that the information accessible by
+discrete Fourier protocols saturates when the sampling rate reaches twice the
+bandwidth of the detected continuous time signal. This maximum rate (the
+NS-limit) plays a prominent role in Magnetic Resonance Imaging (MRI).
+Nevertheless, reconstruction methods other than Fourier analysis can extract
+useful information from data oversampled with respect to the NS-limit, given
+that relevant prior knowledge is available. Here we present PhasE-Constrained
+OverSampled MRI (PECOS), a method that exploits data oversampling in
+combination with prior knowledge of the physical interactions between
+electromagnetic fields and spins in MRI systems. In PECOS, highly
+oversampled-in-time k-space data are fed into a phase-constrained variant of
+Kaczmarz's algebraic reconstruction algorithm, where prior knowledge of the
+expected spin contributions to the signal is codified into an encoding matrix.
+PECOS can be used for scan acceleration in relevant scenarios by oversampling
+along frequency-encoded directions, which is innocuous in MRI systems under
+reasonable conditions. We find situations in which the reconstruction quality
+can be higher than with NS-limited acquisitions and traditional Fourier
+reconstruction. Besides, we compare the performance of a variety of encoding
+pulse sequences as well as image reconstruction protocols, and find that
+accelerated spiral trajectories in k-space combined with algebraic
+reconstruction techniques are particularly advantageous. The proposed sampling
+and reconstruction method is able to improve image quality for fully-sampled
+k-space trajectories, while allowing accelerated or undersampled acquisitions
+without regularization or signal extrapolation to unmeasured regions.",2007.15674v2
+2021-01-17,Metallization of Shock-Compressed Liquid Ammonia,"Ammonia is predicted to be one of the major components in the depths of the
+ice giant planets Uranus and Neptune. Their dynamics, evolution, and interior
+structure are insufficiently understood and models rely imperatively on data
+for equation of state and transport properties. Despite its great significance,
+the experimentally accessed region of the ammonia phase diagram today is still
+very limited in pressure and temperature. Here we push the probed regime to
+unprecedented conditions, up to $\sim$350 GPa and $\sim$40000 K. Along the
+Hugoniot, the temperature measured as a function of pressure shows a subtle
+change in slope at $\sim$7000 K and $\sim$90 GPa, in agreement with ab initio
+simulations we have performed. This feature coincides with the gradual
+transition from a molecular liquid to a plasma state. Additionally, we
+performed reflectivity measurements, providing the first experimental evidence
+of electronic conduction in high-pressure ammonia. Shock reflectance
+continuously rises with pressure above 50 GPa and reaches saturation values
+above 120 GPa. Corresponding electrical conductivity values are up to 1 order
+of magnitude higher than in water in the 100 GPa regime, with possible
+significant contributions of the predicted ammonia-rich layers to the
+generation of magnetic dynamos in ice giant interiors.",2101.06692v1
+2021-02-10,"Screening, Friedel oscillations, RKKY interaction, and Drude transport in anisotropic two-dimensional systems","We investigate the effect of the mass anisotropy on Friedel Oscillations,
+Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, screening properties, and
+Boltzmann transport in two dimensional (2D) metallic and doped semiconductor
+systems. We calculate the static polarizability and the dielectric function
+within the random phase approximation with the mass anisotropy fully taken into
+account without making any effective isotropic approximation in the theory. We
+find that carrier screening exhibits an isotropic behavior for small momenta
+despite the anisotropy of the system, and becomes strongly anisotropic above a
+certain threshold momentum. Such an anisotropy of screening leads to
+anisotropic Friedel oscillations, and an anisotropic RKKY interaction
+characterized by a periodicity dependent on the direction between the localized
+magnetic moments. We also explore the disorder limited dc transport properties
+in the presence of mass anisotropy based on the Boltzmann transport theory.
+Interestingly, we find that the anisotropy ratio of the short range disorder
+limited resistivity along the heavy- and light-mass directions is always the
+same as the mass anisotropy ratio whereas for the long range disorder limited
+resistivity the anisotropy ratio is the same as the mass ratio only in the low
+density limit, and saturates to the square root of the mass ratio in the high
+density limit. Our theoretical work should apply to many existing and
+to-be-discovered anisotropic 2D systems.",2102.05659v2
+2021-02-22,High T$_C$ ferromagnetic inverse Heusler alloys: A comparative study of Fe$_2$RhSi and Fe$_2$RhGe,"We report the results of experimental investigations on structural, magnetic,
+resistivity, caloric properties of Fe$_2$RhZ (Z=Si,Ge) along with
+\textit{ab-initio} band structure calculations using first principle
+simulations. Both these alloys are found to crystallize in inverse Heusler
+structure but with disorder in tetrahedral sites between Fe and Rh. Fe$_2$RhSi
+has saturation moment of 5.00 $\mu_B$ and while its counterpart has 5.19
+$\mu_B$. Resistivity measurement reveals metallic nature in both of them.
+Theoretical simulations using generalized gradient approximation(GGA) predict
+inverse Heusler structure with ferromagnetic ordering as ground state for both
+the alloys. However it underestimates the experimentally observed moments.
+GGA+$U$ approach, with Hubbard $U$ values estimated from density functional
+perturbation theory helps to improve the comparison of the experimental
+results. Fe$_2$RhSi is found to be half metallic ferromagnet while Fe$_2$RhGe
+is not. Varying $U$ values on Fe and Rh sites does not change the net moment
+much in Fe$_2$RhSi, unlike in Fe$_2$RhGe. Relatively small exchange splitting
+of orbitals in Fe$_2$RhGe compared to that of Fe$_2$RhSi is the reason for not
+opening the band gap in the minority spin channel in the former. High ordering
+temperature and moment make Fe$_2$RhSi useful for spintronics applications.",2102.10967v1
+2021-03-10,Role of the symmetry energy on the neutron-drip transition in accreting and nonaccreting neutron stars,"In this paper, we study the role of the symmetry energy on the neutron-drip
+transition in both nonaccreting and accreting neutron stars, allowing for the
+presence of a strong magnetic field as in magnetars. The density, pressure, and
+composition at the neutron-drip threshold are determined using the recent set
+of the Brussels-Montreal microscopic nuclear mass models, which mainly differ
+in their predictions for the value of the symmetry energy $J$ and its slope $L$
+in infinite homogeneous nuclear matter at saturation. Although some
+correlations between on the one hand the neutron-drip density, the pressure,
+the proton fraction and on the other hand $J$ (or equivalently $L$) are found,
+these correlations are radically different in nonaccreting and accreting
+neutron stars. In particular, the neutron-drip density is found to increase
+with $L$ in the former case, but decreases in the latter case depending on the
+composition of ashes from x-ray bursts and superbursts. We have qualitatively
+explained these different behaviors using a simple mass formula. We have also
+shown that the details of the nuclear structure may play a more important role
+than the symmetry energy in accreting neutron-star crusts.",2103.05926v1
+2021-03-22,Many-body localization in tilted and harmonic potentials,"We discuss nonergodic dynamics of interacting spinless fermions in a tilted
+optical lattice as modeled by XXZ spin chain in magnetic (or electric) field
+changing linearly across the chain. The time dynamics is studied using exact
+propagation for small chains and matrix product states techniques for larger
+system sizes. We consider both the initial N\'eel separable state as well as
+the quantum quench scenario in which the initial state may be significantly
+entangled. We show that the entanglement dynamics is significantly different in
+both cases. In the former a rapid initial growth is followed by a saturation
+for sufficiently large tilt, $F$. In the latter case the dynamics seems to be
+dominated by pair tunneling and the effective tunneling rate scales as $1/F^2$.
+In the presence of an additional harmonic potential the imbalance is found to
+be entirely determined by a local effective tilt, $F_{\text{loc}}$, the
+entanglement entropy growth is modulated with frequency that follows
+$1/F_{loc}^2$ scaling first but at long time the dynamics is determined rather
+by the curvature of the harmonic potential. Only for large tilts or
+sufficiently large curvatures, corresponding to the deeply localized regime, we
+find the logarithmic entanglement growth for N\'eel initial state. The same
+curvature determines long-time imbalance for large $F$ which reveals strong
+revival phenomena associated with the manifold of equally spaced states,
+degenerate in the absence of the harmonic potential.",2103.11699v2
+2021-03-30,Positive magnetoresistance and chiral anomaly in exfoliated type-II Weyl semimetal $T_\mathrm{d}$-WTe$_{2}$,"Layered van der Waals semimetallic $T_\mathrm{d}$-WTe$_{2}$, exhibiting
+intriguing properties which include non-saturating extreme positive
+magnetoresistance (MR) and tunable chiral anomaly, has emerged as model
+topological type-II Weyl semimetal system. Here, $\sim$45 nm thick mechanically
+exfoliated flakes of $T_\mathrm{d}$-WTe$_{2}$ are studied $via$ atomic force
+microscopy, Raman spectroscopy, low-$T$/high-$\mu_{0}H$ magnetotransport
+measurements and optical reflectivity. The contribution of anisotropy of the
+Fermi liquid state to the origin of the large positive transverse
+$\mathrm{MR}_\perp$ and the signature of chiral anomaly of the type-II Weyl
+fermions are reported. The samples are found to be stable in air and no
+oxidation or degradation of the electronic properties are observed. A
+transverse $\mathrm{MR}_\perp$ $\sim$1200\,\% and an average carrier mobility
+of $5000$\, cm$^{2}$V$^{-1}$s$^{-1}$ at $T=5\,\mathrm{K}$ for an applied
+perpendicular field $\mu_{0}H_{\perp} = 7\,\mathrm{T}$ are established. The
+system follows a Fermi liquid model for $T\leq50\,\mathrm{K}$ and the
+anisotropy of the Fermi surface is concluded to be at the origin of the
+observed positive MR. The anisotropy of the electronic behaviour is also
+confirmed by optical reflectivity measurements. The relative orientation of the
+crystal axes and of the applied electric and magnetic fields is proven to give
+rise to the observed chiral anomaly in the in-plane magnetotransport.",2103.16326v1
+2021-04-22,Dynamic Spin Fluctuations in the Frustrated Spin Chain Compound Li$_3$Cu$_2$SbO$_6$,"We report the signatures of dynamic spin fluctuations in the layered
+honeycomb Li$_3$Cu$_2$SbO$_6$ compound, with a 3$d$ S = 1/2 $d^9$ Cu$^{2+}$
+configuration, through muon spin rotation and relaxation ($\mu$SR) and neutron
+scattering studies. Our zero-field (ZF) and longitudinal-field (LF)-$\mu$SR
+results demonstrate the slowing down of the Cu$^{2+}$ spin fluctuations below
+4.0 K. The saturation of the ZF relaxation rate at low temperature, together
+with its weak dependence on the longitudinal field between 0 and 3.2 kG,
+indicates the presence of dynamic spin fluctuations persisting even at 80 mK
+without static order. Neutron scattering study reveals the gaped magnetic
+excitations with three modes at 7.7, 13.5 and 33 meV. Our DFT calculations
+reveal that the next nearest neighbors (NNN) AFM exchange ($J_{AFM}$ = 31 meV)
+is stronger than the NN FM exchange ($J_{FM}$ = -21 meV) indicating the
+importance of the orbital degrees of freedom. Our results suggest that the
+physics of Li$_3$Cu$_2$SbO$_6$ can be explained by an alternating AFM chain
+rather than the honeycomb lattice.",2104.10859v1
+2021-05-03,Magnetorotational instability with smoothed particle hydrodynamics,"We present a thorough numerical study on the MRI using the smoothed particle
+magnetohydrodynamics method (SPMHD) with the geometric density average force
+expression (GDSPH). We perform shearing box simulations with different initial
+setups and a wide range of resolution and dissipation parameters. We show, for
+the first time, that MRI with sustained turbulence can be simulated
+successfully with SPH, with results consistent with prior work with grid-based
+codes. In particular, for the stratified boxes, our simulations reproduce the
+characteristic butterfly diagram of the MRI dynamo with saturated turbulence
+for at least 100 orbits. On the contrary, traditional SPH simulations suffer
+from runaway growth and develop unphysically large azimuthal fields, similar to
+the results from a recent study with mesh-less methods. We investigated the
+dependency of MRI turbulence on the numerical Prandtl number in SPH, focusing
+on the unstratified, zero net-flux case. We found that turbulence can only be
+sustained with a Prandtl number larger than $\sim$2.5, similar to the critical
+values of physical Prandtl number found in grid-code simulations. However,
+unlike grid-based codes, the numerical Prandtl number in SPH increases with
+resolution, and for a fixed Prandtl number, the resulting magnetic energy and
+stresses are independent of resolution. Mean-field analyses were performed on
+all simulations, and the resulting transport coefficients indicate no
+$\alpha$-effect in the unstratified cases, but an active $\alpha\Omega$ dynamo
+and a diamagnetic pumping effect in the stratified medium, which are generally
+in agreement with previous studies. There is no clear indication of a
+shear-current dynamo in our simulation, which is likely to be responsible for a
+weaker mean-field growth in the tall, unstratified, zero net-flux simulation.",2105.01091v1
+2021-06-05,"Single-file dynamics of colloids in circular channels: time scales, scaling laws and their universality","In colloidal systems, Brownian motion emerges from the massive separation of
+time and length scales associated to characteristic dynamics of the solute and
+solvent constituents. This separation of scales produces several temporal
+regimes in the colloidal dynamics when combined with the effects of the
+interaction between the particles, confinement conditions, and state variables,
+such as density and temperature. Some examples are the short- and long-time
+regimes in two- and three-dimensional open systems and the diffusive and
+sub-diffusive regimes observed in the single-file dynamics along a straight
+line. This work studies the way in which a confining geometry induces new time
+scales. We report on the dynamics of interacting colloidal particles moving
+along a circle by combining a heuristic theoretical analysis of the involved
+scales, Brownian Dynamics computer simulations, and video-microscopy
+experiments with paramagnetic colloids confined to lithographic circular
+channels subjected to an external magnetic field. The systems display four
+temporal regimes in this order: one-dimensional free diffusion, single-file
+sub-diffusion, free-cluster rotational diffusion, and the expected saturation
+due to the confinement. We also report analytical expressions for the
+mean-square angular displacement and crossover times obtained from scaling
+arguments, which accurately reproduce both experiments and simulations. Our
+generic approach can be used to predict the long-time dynamics of many other
+confined physical systems.",2106.02908v2
+2021-06-28,Exact solutions of few-magnon problems in the spin-$S$ periodic XXZ chain,"We solve few-magnon problems for a finite-size spin-$S$ periodic Heisenberg
+XXZ chain with single-ion anisotropy through constructing sets of exact Bloch
+states achieving block diagonalization of the system. Concretely, the
+two-magnon (three-magnon) problem is converted to a single-particle one on a
+one-dimensional (two-dimensional) effective lattice whose size depends linearly
+(quadratically) on the total number of sites. For parameters lying within
+certain ranges, various types of multimagnon bound states are manifested and
+shown to correspond to edge states on the effective lattices. In the absence of
+the single-ion anisotropy, we reveal the condition under which exact
+zero-energy states emerge. As applications of the formalism, we calculate the
+transverse dynamic structure factor for a higher-spin chain near saturation
+magnetization and find signatures of the multimagnon bound states. We also
+calculate the real-time three-magnon dynamics from certain localized states,
+which are relevant to cold-atom quantum simulations, by simulating
+single-particle quantum walks on the effective lattices. This provides a
+physically transparent interpretation of the observed dynamics in terms of
+propagation of bound state excitations. Our method can be directly applied to
+more general spin or itinerant particle systems possessing translational
+symmetry.",2106.14809v4
+2021-07-14,Visualizing the strongly reshaped skyrmion Hall effect in multilayer wire devices,"Magnetic skyrmions are nanoscale spin textures touted as next-generation
+computing elements. When subjected to lateral currents, skyrmions move at
+considerable speeds. Their topological charge results in an additional
+transverse deflection known as the skyrmion Hall effect (SkHE). While
+promising, their dynamic phenomenology with current, skyrmion size, geometric
+effects and disorder remain to be established. Here we report on the ensemble
+dynamics of individual skyrmions forming dense arrays in Pt/Co/MgO wires by
+examining over 20,000 instances of motion across currents and fields. The
+skyrmion speed reaches 24 m/s in the plastic flow regime and is surprisingly
+robust to positional and size variations. Meanwhile, the SkHE saturates at
+$\sim 22^\circ$, is substantially reshaped by the wire edge, and crucially
+increases weakly with skyrmion size. Particle model simulations suggest that
+the SkHE size dependence - contrary to analytical predictions - arises from the
+interplay of intrinsic and pinning-driven effects. These results establish a
+robust framework to harness SkHE and achieve high-throughput skyrmion motion in
+wire devices.",2107.07022v1
+2021-08-30,Twenty-Five Years of Dissipative Solitons,"In 1995, C. I. Christov and M. G. Velarde introduced the concept of a
+dissipative soliton in a long-wave thin-film equation [Physica D 86, 323--347].
+In the 25 years since, the subject has blossomed to include many related
+phenomena. The focus of this short note is to survey the conceptual influence
+of the concept of a ""production-dissipation (input-output) energy balance"" that
+they identified. Our recent results on nonlinear periodic waves as dissipative
+solitons (in a model equation for a ferrofluid interface in a parallel-flow
+rectangular geometry subject to an inhomogeneous magnetic field) have shown
+that the classical concept also applies to nonlocalized (specifically,
+spatially periodic) nonlinear coherent structures. Thus, we revisit the
+so-called KdV-KSV equation studied by C. I. Christov and M. G. Velarde to
+demonstrate that it also possesses spatially periodic dissipative soliton
+solutions. These coherent structures arise when the linearly unstable flat film
+state evolves to sufficiently large amplitude. The linear instability is then
+arrested when the nonlinearity saturates, leading to permanent traveling waves.
+Although the two model equations considered in this short note feature the same
+prototypical linear long-wave instability mechanism, along with similar linear
+dispersion, their nonlinearities are fundamentally different. These nonlinear
+terms set the shape and eventual dynamics of the nonlinear periodic waves.
+Intriguingly, the nonintegrable equations discussed in this note also exhibit
+multiperiodic nonlinear wave solutions, akin to the polycnoidal waves discussed
+by J. P. Boyd in the context of the completely integrable KdV equation.",2108.13351v1
+2021-09-18,Breaking the Computational Bottleneck: Design of Near-Optimal High-Memory Spatially-Coupled Codes,"Spatially-coupled (SC) codes, known for their threshold saturation phenomenon
+and low-latency windowed decoding algorithms, are ideal for streaming
+applications and data storage systems. SC codes are constructed by partitioning
+an underlying block code, followed by rearranging and concatenating the
+partitioned components in a convolutional manner. The number of partitioned
+components determines the memory of SC codes. In this paper, we investigate the
+relation between the performance of SC codes and the density distribution of
+partitioning matrices. While adopting higher memories results in improved SC
+code performance, obtaining finite-length, high-performance SC codes with high
+memory is known to be computationally challenging. We break this computational
+bottleneck by developing a novel probabilistic framework that obtains (locally)
+optimal density distributions via gradient descent. Starting from random
+partitioning matrices abiding by the obtained distribution, we perform
+low-complexity optimization algorithms that minimize the number of detrimental
+objects to construct high-memory, high-performance quasi-cyclic SC codes. We
+apply our framework to various objects of interests, from the simplest short
+cycles, to more sophisticated objects such as concatenated cycles aiming at
+finer-grained optimization. Simulation results show that codes obtained through
+our proposed method notably outperform state-of-the-art SC codes with the same
+constraint length and optimized SC codes with uniform partitioning. The
+performance gain is shown to be universal over a variety of channels, from
+canonical channels such as additive white Gaussian noise and binary symmetric
+channels, to practical channels underlying flash memory and magnetic recording
+systems.",2109.08978v1
+2021-10-06,Entropic order parameters in weakly coupled gauge theories,"The entropic order parameters measure in a universal geometric way the
+statistics of non-local operators responsible for generalized symmetries. In
+this article, we compute entropic order parameters in weakly coupled gauge
+theories. To perform this computation, the natural route of evaluating
+expectation values of physical (smeared) non-local operators is prevented by
+known difficulties in constructing suitable smeared Wilson loops. We circumvent
+this problem by studying the smeared non-local class operators in the enlarged
+non-gauge invariant Hilbert space. This provides a generic approach for smeared
+operators in gauge theories and explicit formulas at weak coupling. In this
+approach, the Wilson and 't Hooft loops are labeled by the full weight and
+co-weight lattices respectively. We study generic Lie groups and discuss
+couplings with matter fields. Smeared magnetic operators, as opposed to the
+usual infinitely thin ones, have expectation values that approach one at weak
+coupling. The corresponding entropic order parameter saturates to its maximum
+topological value, except for an exponentially small correction, which we
+compute. On the other hand, smeared 't Hooft loops and their entropic disorder
+parameter are exponentially small. We verify that both behaviors match the
+certainty relation for the relative entropies. In particular, we find upper and
+lower bounds (that differ by a factor of 2) for the exact coefficient of the
+linear perimeter law for thin loops at weak coupling. This coefficient is
+unphysical/non-universal for line operators. We end with some comments
+regarding the RG flows of entropic parameters through perturbative beta
+functions.",2110.02980v2
+2021-11-10,"Very-High Dynamic Range, 10,000 frames/second Pixel Array Detector for Electron Microscopy","Precision and accuracy of quantitative scanning transmission electron
+microscopy (STEM) methods such as ptychography, and the mapping of electric,
+magnetic and strain fields depend on the dose. Reasonable acquisition time
+requires high beam current and the ability to quantitatively detect both large
+and minute changes in signal. A new hybrid pixel array detector (PAD), the
+second-generation Electron Microscope Pixel Array Detector (EMPAD-G2),
+addresses this challenge by advancing the technology of a previous generation
+PAD, the EMPAD. The EMPAD-G2 images continuously at a frame-rates up to 10 kHz
+with a dynamic range that spans from low-noise detection of single electrons to
+electron beam currents exceeding 180 pA per pixel, even at electron energies of
+300 keV. The EMPAD-G2 enables rapid collection of high-quality STEM data that
+simultaneously contain full diffraction information from unsaturated bright
+field disks to usable Kikuchi bands and higher-order Laue zones. Test results
+from 80 to 300 keV are presented, as are first experimental results
+demonstrating ptychographic reconstructions, strain and polarization maps. We
+introduce a new information metric, the Maximum Usable Imaging Speed (MUIS), to
+identify when a detector becomes electron-starved, saturated or its pixel count
+is mismatched with the beam current.",2111.05889v1
+2021-12-06,Mechanism of spin ordering in Fe$_{3}$O$_{4}$ nanoparticles by surface coating with organic acids,"Saturation magnetization values close to the bulk have been reported for
+coated magnetite nanoparticles with organic acids. The mechanism of this effect
+is not yet understood. Here we show that a previously proposed rationalization
+in Nano Letters 12 (2021) 2499-2503 was based on electronic structure
+properties that are not consistent with several existing density functional
+theory studies. Our study is based on a wide set of Hubbard-corrected density
+functional tight binding (DTFB+U) and hybrid density functional theory (HSE06)
+calculations on Fe$_{3}$O$_{4}$ nanocubes of more than 400 atoms. We provide a
+new explanation for the spin ordering in coated nanoparticles, through the
+investigation of spin-flipping phenomena. In particular, we show that the
+spin-flip of d electrons at octahedral Fe$^{3+}$ sites, which is confirmed to
+be more favorable near the surface, especially where atomic reorganization can
+take place such as at corner sites, can be hampered by the presence of adsorbed
+organic acids because they do not only limit the surface reconstruction but
+also allow for additional ferromagnetic superexchange interaction between
+octahedral Fe sites as a consequence of the carboxylates bridging binding mode.
+The proof-of-concept of this mechanism is given by a simplified model of the
+Fe(III) tert-butoxide dimer.",2112.02966v2
+2021-12-21,Fast long-wavelength exchange spin waves in partially-compensated Ga:YIG,"Spin waves in yttrium iron garnet (YIG) nano-structures attract increasing
+attention from the perspective of novel magnon-based data processing
+applications. For short wavelengths needed in small-scale devices, the group
+velocity is directly proportional to the spin-wave exchange stiffness constant
+$\lambda_\mathrm{ex}$. Using wave vector resolved Brillouin Light Scattering
+(BLS) spectroscopy, we directly measure $\lambda_\mathrm{ex}$ in Ga-substituted
+YIG thin films and show that it is about three times larger than for pure YIG.
+Consequently, the spin-wave group velocity overcomes the one in pure YIG for
+wavenumbers $k > 4$ rad/$\mu$m, and the ratio between the velocities reaches a
+constant value of around 3.4 for all $k > 20$ rad/$\mu$m. As revealed by
+vibrating-sample magnetometry (VSM) and ferromagnetic resonance (FMR)
+spectroscopy, Ga:YIG films with thicknesses down to 59 nm have a low Gilbert
+damping ($\alpha < 10^{-3}$), a decreased saturation magnetization $\mu_0
+M_\mathrm{S}~\approx~20~$mT and a pronounced out-of-plane uniaxial anisotropy
+of about $\mu_0 H_{\textrm{u1}} \approx 95 $ mT which leads to an out-of-plane
+easy axis. Thus, Ga:YIG opens access to fast and isotropic spin-wave transport
+for all wavelengths in nano-scale systems independently of dipolar effects.",2112.11348v1
+2021-12-31,Ferromagnetic Enhancement in LaMnO3 Films with Release and Flexure,"A variety of novel phenomena and functionalities emerge from lowering the
+dimensionality of materials and enriching the degrees of freedom in modulation.
+In this work, it is found that the saturation magnetization of LaMnO3 (LMO)
+films is largely enhanced by 56% after releasing from a brand-new phase of
+tetragonal strontium aluminate buffer layer, and is significantly increased by
+92% with bending films to a curvature of 1 mm-1 using a water-assisted
+direct-transferring method. Meanwhile, the Curie temperature of LMO films has
+been improved by 13 K. High-resolution spherical aberration-corrected scanning
+transmission electron microscopy and first-principles calculations
+unambiguously demonstrate that the enhanced ferromagnetism is attributed to the
+strengthened Mn-O-Mn super-exchange interactions from the augmented
+characteristics of the unconventional P21/n structure caused by the
+out-of-plane lattice shrinking after strain releasing and increased flexure
+degree of freestanding LMO films. This work paves a way to achieve large-scale
+and crack-and-wrinkle-free freestanding films of oxides with largely improved
+functionalities.",2112.15307v1
+2022-01-10,$B^2$ to $B$-linear magnetoresistance due to impeded orbital motion,"Strange metals exhibit a variety of anomalous magnetotransport properties,
+the most striking of which is a resistivity that increases linearly with
+magnetic field $B$ over a broad temperature and field range. The ubiquity of
+this behavior across a spectrum of correlated metals - both single- and
+multi-band, with either dominant spin and/or charge fluctuations, of varying
+levels of disorder or inhomogeneity and in proximity to a quantum critical
+point or phase - obligates the search for a fundamental underlying principle
+that is independent of the specifics of any material. Strongly anisotropic
+(momentum-dependent) scattering can generate $B$-linear magnetoresistance but
+only at intermediate field strengths. At high enough fields, the
+magnetoresistance must eventually saturate. Here, we consider the ultimate
+limit of such anisotropy, a region or regions on the Fermi surface that impede
+all orbital (cyclotron) motion through them, but whose imposition can be
+modelled nonetheless through a modified Boltzmann theoretical treatment.
+Application of the proposed theorem suggests that the realization of
+quadratic-to-linear magnetoresistance requires the presence of a bounded sector
+on the Fermi surface possibly separating two distinct types of carriers. While
+this bounded sector may have different origins or manifestations, we expect its
+existence to account for the anomalous magnetotransport found in a wide range
+of correlated materials.",2201.03292v1
+2022-01-20,Quantum Dipolar Coupling Thermal Correction for NMR Signal during Natural Rock Flooding by Melding Experimentation and Numerical Simulation (Th-CENS),"Researchers have used NMR to measure multi-phase fluid saturation and
+distribution inside porous media of natural rock. However, the NMR signal
+amplitude suffers reduction with the increase of temperature. The main reason
+is the Transverse Overhauser Effect, where heating increases the freedom for
+ionic motion, affecting spinning behavior by having two spins go in two
+opposite directions to form the Dipolar Coupling. We approach solving NMR
+thermal effects correction by melding experimentation and numerical simulation
+method. We use NMR for Cretaceous carbonate rock multi-phase flow research. We
+conduct time step in-situ temperature measurement for four different sections
+of the flooding system at the inlet, center, and outlet along the flooding
+path. In addition, we conduct a temperature measurement at the NMR device
+radial axis, representing the permanent magnet temperature. We build a 3D
+cylindrical heat transfer model for the numerical simulator that simulates
+thermal effect distribution on the NMR for optimally generating the correction
+model. The insight provided by the simulator improved the understanding of the
+thermal distribution at the natural rock core plug to produce a better thermal
+correction model that meld experimentation and simulation, a method we call
+Th-CENS.",2201.08834v1
+2022-02-09,Giant transverse and longitudinal magneto-thermoelectric effect in polycrystalline nodal-line semimetal Mg3Bi2,"Topological semimetals provide new opportunities for exploring new
+thermoelectric phenomena, because of their exotic and nontrivial electronic
+structure topology around the Fermi surface. In this study, we report on the
+discovery of giant transverse and longitudinal magneto-thermoelectric (MTE)
+effects in Mg3Bi2, which is predicted to be a type-II nodal-line semimetal in
+the absence of spin-orbit coupling (SOC). The maximum transverse power factor
+is 2182 {\mu}Wm^{-1}K^{-2} at 13.5 K and 6 Tesla. The longitudinal power factor
+reaches up to 3043{\mu}Wm^{-1}K^{-2} at 15 K and 13 Tesla, which is 20 times
+higher than in a zero-strength magnetic field and is also comparable to
+state-of-the-art MTE materials. By compensating Mg loss in the Mg-rich
+conditions for turning carrier concentration, the sample obtained in this work
+shows a large linear non-saturating magnetoresistance of 940% under a field of
+14 Tesla. This is a two-orders-of-magnitude increase with respect to the normal
+Mg-deficiency Mg3Bi2 sample. Using density functional calculations, we
+attribute the underlying mechanism to the parent nodal-line electronic
+structure without SOC and the anisotropic Fermi surface shape with SOC,
+highlighting the essential role of high carrier mobility and open electron
+orbits in moment space. Our work offers a new avenue toward highly efficient
+thermoelectric materials through the design of Fermi surfaces with special
+topological electronic structures in novel quantum materials.",2202.04293v1
+2022-04-26,AGN jets do not prevent the suppression of conduction by the heat buoyancy instability in simulated galaxy clusters,"Centres of galaxy clusters must be efficiently reheated to avoid a cooling
+catastrophe. One potential reheating mechanism is anisotropic thermal
+conduction, which could transport thermal energy from intermediate radii to the
+cluster center. However, if fields are not re-randomised, anisotropic thermal
+conduction drives the heat buoyancy instability (HBI) which reorients magnetic
+field lines and shuts off radial heat fluxes. We revisit the efficiency of
+thermal conduction under the influence of spin-driven AGN jets in idealised
+magneto-hydrodynamical simulations with anisotropic thermal conduction. Despite
+the black hole spin's ability to regularly re-orientate the jet so that the
+jet-induced turbulence is driven in a quasi-isotropic fashion, the HBI remains
+efficient outside the central 50 kpc of the cluster, where the reservoir of
+heat is the largest. As a result, conduction plays no significant role in
+regulating the cooling of the intra-cluster medium if central active galactic
+nuclei are the sole source of turbulence. Whistler-wave driven saturation of
+thermal conduction reduces the magnitude of the HBI but does not prevent it.",2204.12514v2
+2022-04-26,Band Flattening and Landau Level Merging in Strongly-Correlated Two-Dimensional Electron Systems,"We review recent experimental results indicating the band flattening and
+Landau level merging at the chemical potential in strongly-correlated
+two-dimensional (2D) electron systems. In ultra-clean, strongly interacting 2D
+electron system in SiGe/Si/SiGe quantum wells, the effective electron mass at
+the Fermi level monotonically increases in the entire range of electron
+densities, while the energy-averaged mass saturates at low densities. The
+qualitatively different behavior of the two masses reveals a precursor to the
+interaction-induced single-particle spectrum flattening at the chemical
+potential in this electron system, in which case the fermion ""condensation"" at
+the Fermi level occurs in a range of momenta, unlike the condensation of
+bosons. In strong magnetic fields, perpendicular to the 2D electron layer, a
+similar effect of different fillings of quantum levels at the chemical
+potential -- the merging of the spin- and valley-split Landau levels at the
+chemical potential -- is observed in Si inversion layers and bilayer 2D
+electron system in GaAs. Indication of merging of the quantum levels of
+composite fermions with different valley indices is also reported in
+ultra-clean SiGe/Si/SiGe quantum wells.",2204.12565v3
+2022-04-27,"Prospects for a flavour violating $Z^\prime$ explanation of $Δ a_{μ,e}$","The apparent tensions emerging from the comparison of experimental data of
+the anomalous magnetic moments of the muon and electron to the Standard Model
+predictions ($\Delta a_{\mu,e}$) could be interpreted as a potential signal of
+New Physics. Models encompassing a light vector boson have been known to offer
+a satisfactory explanation to $\Delta a_{\mu}$, albeit subject to stringent
+experimental constraints. Here we explore a minimal extension of the Standard
+Model via a leptophilic vector boson $Z^\prime$, under the hypothesis of
+strictly flavour-violating couplings of the latter to leptons. The most
+constraining observables to this ad-hoc construction emerge from lepton flavour
+universality violation (in $Z$ and $\tau$ decays) and from rare charged lepton
+flavour violating transitions. Once these are accommodated, one can saturate
+the tensions in $\Delta a_{\mu}$, but $\Delta a_{e}$ is predicted to be
+Standard Model-like. We infer prospects for several observables, including
+leptonic $Z$ decays and several charged lepton flavour violating processes. We
+also discuss potential signatures of the considered $Z^\prime$ at a future muon
+collider, emphasising the role of the $\mu^+\mu^- \to\tau^+\tau^- $
+forward-backward asymmetry as a key probe of the model.",2204.13134v3
+2022-05-04,Surface states induced weak anti-localization effect in Bi0.85Sb0.15 topological single crystal,"We report, an experimental evidence of surface states (SS) driven
+magneto-transport in a Bi0.85Sb0.15 single crystal. Detailed high field (up to
+12T) and low temperature (down to 2K) magneto-transport measurements are been
+carried out on the studied Bi0.85Sb0.15 single crystal. The phase, composition
+and Raman modes are studied through X-ray diffraction, Energy dispersive X-ray,
+and Raman spectroscopy. The obtained crystal shows non-saturating
+magnetoresistance (4250%) at 2K and 12T, along with the existence of weak-anti
+localization (WAL) effect at around zero magnetic field. Further, the
+Hikami-Larkin-Nagaoka (HLN) analysis is performed to analyse the WAL effect.
+The prefactor and phase coherence length are deduced at various temperatures,
+which signified the presence of more than one conduction channel in the studied
+Bi0.85Sb0.15 single crystal. The effect of quantum scattering, bulk
+contribution from underneath the surface states and defects are been studied by
+adding various field dependent quadratic, linear and constant terms to the SS
+driven HLN equation. Various possible scattering mechanism are studied by
+analysing the temperature dependence of the phase coherence length. Angle
+dependent magneto-conductivity of the studied Bi0.85Sb0.15 single crystal
+clearly confirmed the surface states dominated transport in present crystal.",2205.01880v2
+2022-05-04,Mixing the solar wind proton and electron scales. Theory and 2D-PIC simulations of firehose instability,"Firehose-like instabilities (FIs) are cited in multiple astrophysical
+applications. Of particular interest are the kinetic manifestations in
+weakly-collisional or even collisionless plasmas, where these instabilities are
+expected to contribute to the evolution of macroscopic parameters. Relatively
+recent studies have initiated a realistic description of FIs, as induced by the
+interplay of both species, electrons and protons, dominant in the solar wind
+plasma. This work complements the current knowledge with new insights from
+linear theory and the first disclosures from 2D PIC simulations, identifying
+the fastest growing modes near the instability thresholds and their long-run
+consequences on the anisotropic distributions. Thus, unlike previous setups,
+these conditions are favorable to those aperiodic branches that propagate
+obliquely to the uniform magnetic field, with (maximum) growth rates higher
+than periodic, quasi-parallel modes. Theoretical predictions are, in general,
+confirmed by the simulations. The aperiodic electron FI (a-EFI) remains
+unaffected by the proton anisotropy, and saturates rapidly at low-level
+fluctuations. Regarding the firehose instability at proton scales, we see a
+stronger competition between the periodic and aperiodic branches. For the
+parameters chosen in our analysis, the a-PFI is excited before than the p-PFI,
+with the latter reaching a significantly higher fluctuation power. However,
+both branches are significantly enhanced by the presence of anisotropic
+electrons. The interplay between EFIs and PFIs also produces a more pronounced
+proton isotropization.",2205.02338v1
+2022-07-18,Josephson Diode Effect in High Mobility InSb Nanoflags,"We report evidence of non-reciprocal dissipation-less transport in single
+ballistic InSb nanoflag Josephson junctions, owing to a strong spin-orbit
+coupling. Applying an in-plane magnetic field, we observe an inequality in
+supercurrent for the two opposite current propagation directions. This
+demonstrates that these devices can work as Josephson diodes, with
+dissipation-less current flowing in only one direction. For small fields, the
+supercurrent asymmetry increases linearly with the external field, then it
+saturates as the Zeeman energy becomes relevant, before it finally decreases to
+zero at higher fields. We show that the effect is maximum when the in-plane
+field is perpendicular to the current vector, which identifies Rashba
+spin-orbit coupling as the main symmetry-breaking mechanism. While a variation
+in carrier concentration in these high-quality InSb nanoflags does not
+significantly influence the diode effect, it is instead strongly suppressed by
+an increase in temperature. Our experimental findings are consistent with a
+model for ballistic short junctions and show that the diode effect is intrinsic
+to this material. Our results establish InSb Josephson diodes as a useful
+element in superconducting electronics.",2207.08772v1
+2022-08-10,A Feshbach resonance in collisions between ultracold ground state molecules,"Collisional resonances are an important tool which has been used to modify
+interactions in ultracold gases, for realizing novel Hamiltonians in quantum
+simulations, for creating molecules from atomic gases and for controlling
+chemical reactions. So far, such resonances have been observed for atom-atom
+collisions, atom-molecule collisions and collisions between Feshbach molecules
+which are very weakly bound. Whether such resonances exist for ultracold ground
+state molecules has been debated due to the possibly high density of states
+and/or rapid decay of the resonant complex. Here we report a very pronounced
+and narrow (25 mG) Feshbach resonance in collisions between two ground state
+NaLi molecules. This molecular Feshbach resonance has two special
+characteristics. First, the collisional loss rate is enhanced by more than two
+orders of magnitude above the background loss rate which is saturated at the
+$p$-wave universal value, due to strong chemical reactivity. Second, the
+resonance is located at a magnetic field where two open channels become nearly
+degenerate. This implies the intermediate complex predominantly decays to the
+second open channel. We describe the resonant loss feature using a model with
+coupled modes which is analogous to a Fabry-P\'erot cavity. Our observations
+prove the existence of long-lived coherent intermediate complexes even in
+systems without reaction barriers and open up the possibility of coherent
+control of chemical reactions.",2208.05557v1
+2022-09-13,The influence of host star activity evolution on the population of super-Earths and mini-Neptunes,"The detected exoplanet population displays a dearth of planets with sizes of
+about two Earth radii, the so-called radius gap. This is interpreted as an
+evolutionary effect driven by a variety of possible atmospheric mass loss
+processes of exoplanets. For mass loss driven by an exoplanet's irradiation by
+stellar X-ray and extreme-UV photons, the time evolution of the stellar
+magnetic activity is important. It is known from observations of open stellar
+clusters that stars of the same age and mass do not all follow the same time
+evolution of activity-induced X-ray and extreme-UV luminosities. Here we
+explore how a realistic spread of different stellar activity tracks influences
+the mass loss and radius evolution of a simulated population of small
+exoplanets and the observable properties of the radius gap. Our results show
+qualitatively that different saturation time scales, i.e. the young age at
+which stellar high-energy emission starts to decline, and different activity
+decay tracks over moderate stellar ages can cause changes in the population
+density of planets in the gap, as well as in the observable width of the gap.
+We also find that while the first 100 million years of mass loss are highly
+important to shape the radius gap, significant evolution of the gap properties
+is expected to take place for at least the first 500-600 million years, i.e.
+the age of the Hyades cluster. Observations of exoplanet populations with
+defined ages will be able to shed more light on the radius gap evolution.",2209.05860v1
+2022-09-27,Spatially Dependent Photometric Activity of M dwarfs in the Solar Cylinder,"We study the relationship between Galactic location ($R, Z$) and photometric
+activity for 3.6 million M dwarf stars within 1 kpc of the Sun. For this
+purpose, we identify 906 unique flare events as a proxy for magnetic activity
+from the SkyMapper Southern Survey DR3. We adopt vertical distance $|Z|$ from
+the Galactic disc as a proxy for age and confirm a strong trend of flaring
+fraction decreasing with growing stellar age. Among M dwarfs within 50 pc of
+the Sun, we find a flaring fraction of 1-in-1,500, independent of spectral type
+from M2 to M7, suggesting that these stars are all in a flare-saturated young
+evolutionary stage. We find a hint of a kink in the slope of the overall flare
+fraction near 100 pc from the plane, where a steep decline begins; this slope
+change is visible for mid-type M dwarfs (M3--M5), suggesting it is not an
+artefact of mixing spectral type. Together with SDSS H$\alpha$ emission, this
+trend is additional evidence that the activity fraction of M dwarfs depends on
+Galactic height and activity lifetime. While there is a hint of flattening of
+the overall activity fraction above $|Z|\approx$ 500 pc, our data do not
+constrain this further. Within $\sim$500 pc distance from the Sun, we find no
+sign of radial disk gradients in flare activity, which may only be revealed by
+samples covering a larger radial range.",2209.13107v1
+2022-10-17,Saturation of the filamentation instability and dispersion measure of Fast Radio Bursts,"Nonlinear effects are crucial for the propagation of Fast Radio Bursts (FRBs)
+near the source. We study the filamentation of FRBs in the relativistic winds
+of magnetars, which are commonly invoked as the most natural FRB progenitors.
+As a result of filamentation, the particle number density and the radiation
+intensity develop strong gradients along the direction of the wind magnetic
+field. A steady state is reached when the plasma pressure balances the
+ponderomotive force. In such a steady state, particles are confined into
+periodically spaced thin sheets, and electromagnetic waves propagate between
+them as in a waveguide. We show that: (i) The dispersion relation resembles
+that in the initial homogeneous plasma, but the effective plasma frequency is
+determined by the separation of the sheets, not directly by the mean particle
+density. (ii) The contribution of relativistic magnetar winds to the dispersion
+measure of FRBs could be several orders of magnitude larger than previously
+thought. The dispersion measure of the wind depends on the properties of
+individual bursts (e.g. the luminosity), and therefore can change significantly
+among different bursts from repeating FRBs. (iii) Induced Compton scattering is
+suppressed because most of the radiation propagates in near vacuum regions.",2210.08754v2
+2022-12-05,Propagating spin-wave spectroscopy in nanometer-thick YIG films at millikelvin temperatures,"Performing propagating spin-wave spectroscopy of thin films at millikelvin
+temperatures is the next step towards the realisation of large-scale integrated
+magnonic circuits for quantum applications. Here we demonstrate spin-wave
+propagation in a $100\,\mathrm{nm}$-thick yttrium-iron-garnet film at the
+temperatures down to $45 \,\mathrm{mK}$, using stripline nanoantennas deposited
+on YIG surface for the electrical excitation and detection. The clear
+transmission characteristics over the distance of $10\,\mu \mathrm{m}$ are
+measured and the subtracted spin-wave group velocity and the YIG saturation
+magnetisation agree well with the theoretical values. We show that the
+gadolinium-gallium-garnet substrate influences the spin-wave propagation
+characteristics only for the applied magnetic fields beyond $75\,\mathrm{mT}$,
+originating from a GGG magnetisation up to $47 \,\mathrm{kA/m}$ at $45
+\,\mathrm{mK}$. Our results show that the developed fabrication and measurement
+methodologies enable the realisation of integrated magnonic quantum
+nanotechnologies at millikelvin temperatures.",2212.02257v3
+2023-03-09,The strong effect of electron thermal conduction on the global structure of the heliosphere,"Voyager 1 and 2 crossed the heliopause at $\sim$122 AU in 2012 and $\sim$119
+AU in 2018, respectively. It was quite a surprise because the thickness of the
+inner heliosheath obtained by the existing at that time models of the global
+heliosphere was significantly larger (by 20-40 AU). Until now, the problem of
+the heliosheath thickness has not been fully resolved. Earlier in the frame of
+an oversimplified toy model of nearly isothermal solar wind plasma it has been
+shown that the effect of electron thermal conduction may significantly reduce
+the thickness of the inner heliosheath.
+  In this paper, we present the first results of our 3D kinetic-MHD model of
+the global heliosphere, where the effect of thermal electron conduction has
+been considered rigorously. The thermal conduction acts mainly along the
+magnetic field lines. Classical and saturated thermal fluxes are employed when
+appropriate.
+  It is shown the effects of thermal conduction are significant. The thickness
+of the inner heliospheric is reduced. It is desired effect since it helps to
+reconcile the thickness obtained in the model with Voyager data. The other
+effects are the strong depletion of the heliosheath plasma temperature toward
+the heliopause and the increase of the plasma temperature in the supersonic
+solar wind upstream of the termination shock.",2303.05547v1
+2023-03-27,Turbulence in the Tail of a Jellyfish Galaxy,"When galaxies move through the intracluster medium (ICM) inside galaxy
+clusters, the ram pressure of the ICM can strip the gas from galaxies. The
+stripped gas forms tails on the trailing side. These galaxies are hence dubbed
+``jellyfish galaxies''. ESO 137-001 is a quintessential jellyfish galaxy
+located in the nearest rich cluster, the Norma cluster. Its spectacular
+multiphase tail has complex morphology and kinematics both from the imprinted
+galaxy's interstellar medium (ISM) and as a result of the interactions between
+the stripped gas and the surrounding hot plasma, mediated by radiative cooling
+and magnetic fields. We study the kinematics of the multiphase tail using
+high-resolution observations of the ionized and the molecular gas in the entire
+structure. We calculate the velocity structure functions (VSFs) in moving
+frames along the tail and find that turbulence driven by Kelvin-Helmholtz (KH)
+instability quickly overwhelms the original ISM turbulence and saturates at
+$\sim 30$ kpc. There is also a hint that the far end of the tail has possibly
+started to inherit pre-existing large-scale ICM turbulence likely caused by
+structure formation. Turbulence measured by the molecular gas is generally
+consistent with that measured by the ionized gas in the tail but has a slightly
+lower amplitude. Most of the measured turbulence is below the mean free path of
+the hot ICM ($\sim 11$ kpc). Using warm/cool gas as a tracer of the hot ICM, we
+find that the isotropic viscosity of the hot plasma must be suppressed below
+0.01 percent Spitzer level.",2303.15500v1
+2023-05-29,Deciphering the physical basis of the intermediate-scale instability,"We study the underlying physics of cosmic-ray (CR) driven instabilities that
+play a crucial role for CR transport across a wide range of scales, from
+interstellar to galaxy cluster environments. By examining the linear dispersion
+relation of CR-driven instabilities in a magnetised electron-ion background
+plasma, we establish that both, the intermediate and gyroscale instabilities
+have a resonant origin and show that these resonances can be understood via a
+simple graphical interpretation. These instabilities destabilise wave modes
+parallel to the large-scale background magnetic field at significantly distinct
+scales and with very different phase speeds. Furthermore, we show that
+approximating the electron-ion background plasma with either
+magnetohydrodynamics (MHD) or Hall-MHD fails to capture the fastest growing
+instability in the linear regime, namely the intermediate-scale instability.
+This finding highlights the importance of accurately characterising the
+background plasma for resolving the most unstable wave modes. Finally, we
+discuss the implications of the different phase speeds of unstable modes on
+particle-wave scattering. Further work is needed to investigate the relative
+importance of these two instabilities in the non-linear, saturated regime and
+to develop a physical understanding of the effective CR transport coefficients
+in large-scale CR hydrodynamics theories.",2305.18050v2
+2023-08-14,Gate-tunable kinetic inductance parametric amplifier,"Superconducting parametric amplifiers play a crucial role in the preparation
+and readout of quantum states at microwave frequencies, enabling high-fidelity
+measurements of superconducting qubits. Most existing implementations of these
+amplifiers rely on the nonlinearity from Josephson junctions, superconducting
+quantum interference devices or disordered superconductors. Additionally,
+frequency tunability arises typically from either flux or current biasing. In
+contrast, semiconductor-based parametric amplifiers are tunable by local
+electric fields, which impose a smaller thermal load on the cryogenic setup
+than current and flux biasing and lead to vanishing crosstalk to other on-chip
+quantum systems. In this work, we present a gate-tunable parametric amplifier
+that operates without Josephson junctions, utilizing a proximitized
+semiconducting nanowire. This design achieves near-quantum-limited performance,
+featuring more than 20 dB gain and a 30 MHz gain-bandwidth product. The absence
+of Josephson junctions allows for advantages, including substantial saturation
+powers of -120dBm, magnetic field compatibility up to 500 mT and frequency
+tunability over a range of 15 MHz. Our realization of a parametric amplifier
+supplements efforts towards gate-controlled superconducting electronics,
+further advancing the abilities for high-performing quantum measurements of
+semiconductor-based and superconducting quantum devices.",2308.06989v2
+2023-08-23,Detecting Magnetar Giant Flares with MoonBEAM,"Magnetars are slowly-rotating neutron stars with extremely strong magnetic
+fields that rarely produce extremely bright, energetic giant flares. Magnetar
+Giant Flares (MGFs) begin with a short (200 ms) intense flash, followed by
+fainter emission lasting several minutes that is modulated by the magnetar spin
+period (typically 2-12 s). Over the last 40 years, only three MGFs have been
+observed within our Galaxy and the Magellanic Clouds, which all suffered from
+instrumental saturation due to their extreme intensity. It has been proposed,
+that extragalactic MGFs masquerade as a small subset of short Gamma-ray Bursts
+(GRBs), noting that the sensitivity of current instrumentation prevents us from
+detecting the pulsating tail to distances slightly beyond the Magellanic
+Clouds. However, their initial bright flash is readily observable out to
+distances of < 25 Mpc. In this presentation, we will evaluate the spectral and
+temporal behaviors of MGFs using recent observations from events such as
+GRB200415A, to differentiate them from other progenitors, such as short GRBs.
+We then present an overview of the Moon Burst Energetics All-sky Monitor
+(MoonBEAM), which will attempt to discover more of these events, providing
+highly sensitive data that will help unravel the nature of these phenomena
+further in an attempt to better understand their emission mechanisms
+comparatively with GRBs. In doing so, MoonBEAM will help provide a
+comprehensive picture of energetic astrophysical phenomena, a key goal of the
+Astro2020 decadal survey.",2308.12396v1
+2023-09-01,Naked forward shock seen in the TeV afterglow data of GRB221009A,"We explore the implications of the light curve of the early TeV gamma-ray
+afterglow of GRB221009A reported by the LHAASO collaboration. We show that the
+reported offset of the reference time, $T_*$, allows the determination of the
+relativistic jet activation time, which occurs approximately $200\,\mathrm{s}$
+after the GBM trigger time and closely precedes the moment at which GBM was
+saturated. We find that while the LHAASO data do not exclude the homogeneous
+circumburst medium scenario, the progenitor wind scenario looks preferable,
+finding excellent agreement with the expected size of the stellar bubble. We
+conclude that the initial growth of the light curve is dominated by processes
+internal to the jet or by gamma-gamma attenuation on the photons emitted during
+the prompt phase. Namely, either the activation of the acceleration process or
+the decrease of internal gamma-gamma absorption can naturally explain the
+initial rapid flux increase. The subsequent slow flux growth phase observed up
+to $T_*+18\,\mathrm{s}$ is explained by the build-up of the synchrotron
+radiation -- the target for inverse Compton scattering, which is also supported
+by a softer TeV spectrum measured during this period. The duration of this
+phase allows an almost parameter-independent determination of the jet's initial
+Lorentz factor, $\Gamma_0\approx600$, and magnetic field strength,
+$B'\sim0.3\,\mathrm{G}$. These values appear to match well those previously
+revealed through spectral modeling of the GRB emission.",2309.00673v1
+2023-10-12,Positronium laser cooling via the $1^3S$-$2^3P$ transition with a broadband laser pulse,"We report on laser cooling of a large fraction of positronium (Ps) in
+free-flight by strongly saturating the $1^3S$-$2^3P$ transition with a
+broadband, long-pulsed 243 nm alexandrite laser. The ground state Ps cloud is
+produced in a magnetic and electric field-free environment. We observe two
+different laser-induced effects. The first effect is an increase in the number
+of atoms in the ground state after the time Ps has spent in the long-lived
+$3^3P$ states. The second effect is the one-dimensional Doppler cooling of Ps,
+reducing the cloud's temperature from 380(20) K to 170(20) K. We demonstrate a
+58(9) % increase in the coldest fraction of the Ps ensemble.",2310.08760v1
+2023-10-23,Scrambling in Ising spin systems with constant and periodic transverse magnetic fields,"Scrambling of quantum information in both integrable and nonintegrable
+systems, including the transverse field Ising model (TFIM) and Floquet spin
+systems are studied. Our study employs tripartite mutual information (TMI),
+with negative TMI serving as an indicator of scrambling, where a more negative
+value suggests a higher degree of scrambling. In the integrable and
+nonintegrable TFIM, we observe pronounced scrambling behavior, with the initial
+growth following a power-law pattern. However, nonintegrable TFIM exhibits a
+higher degree of scrambling compared to the integrable version. In the Floquet
+system, TMI is studied across periods from $0$ to $\pi/2$. Both integrable and
+nonintegrable Floquet systems display scrambling behavior across all periods,
+except at $\tau=\pi/4$, featuring power-law growth for small periods and abrupt
+jumps for larger ones. Nonintegrable Floquet systems exhibit more pronounced
+scrambling compared to integrable ones across all periods. The degree of
+scrambling increases as we move towards $\tau = \pi/4$, reaching its peak near
+$\tau = \pi/4$ (but not at $\tau = \pi/4$), regardless of the initial states.
+TMI saturation fluctuates less in the Floquet system in comparison to the TFIM.
+The growth of scrambling in the Floquet system mirrors TFIM for small periods
+but exhibits notably faster growth for larger periods. For a small period, the
+degree of scrambling in a Floquet system is comparable to that in the TFIM, but
+it becomes significantly greater for larger periods.",2310.14620v1
+2023-12-14,Revisiting RXTE observations of MXB 0656-072 during the type I outbursts in 2007-2008,"We report on the timing characteristics of MXB 0656-072 throughout its
+2007-2008 type I outbursts utilising RXTE/PCA and Fermi/GBM data. Using pulse
+timing technique, we explore the spin frequency evolution of the source during
+this interval. Subsequently, by examining the torque-luminosity relation, we
+show that the overall frequency evolution is substantially in line with the
+Ghosh-Lamb model. Furthermore, the residuals of the spin frequencies do not
+exhibit clear orbital modulations, which possibly indicate that the system is
+observed on a relatively top view. In the RXTE/PCA observations, the pulsed
+emission is found to be disappearing below $\sim$$5 \times 10^{36}$ erg
+s$^{-1}$, whereas the profiles maintain stability above this value within our
+analysis timeframe. In addition, we incorporate two novel methods along with
+the conventional Deeter method in order to generate higher-resolution power
+density spectra (PDS). A red noise pattern in the PDSs is also verified in
+these new methods, common in disk-fed sources, with a steepness of $\Gamma \sim
+-2$, reaching saturation at a time-scale of $\sim$150 d. Considering the models
+for spectral transitions, we discuss the possible scenarios for the dipolar
+magnetic field strength of MXB 0656-072 and its coherence with deductions from
+the cyclotron resonance scattering feature (CRSF).",2312.08943v1
+2024-01-25,Thermal and Magnetoelastic Properties of the van der Waals Ferromagnet Fe$_{3-δ}$GeTe$_2$: Anisotropic Spontaneous Magnetostriction and Ferromagnetic Magnon Excitations,"By determining the lattice parameters as a function of temperature of the
+hexagonal van der Waals ferromagnet Fe$_{2.92(1)}$Ge$_{1.02(3)}$Te$_2$ we
+obtain the temperature dependence of the spontaneous in-plane magnetostriction
+in the ferromagnetic and the linear thermal expansion coefficients in the
+paramagnetic state. The spontaneous magnetostriction is clearly seen in the
+temperature dependence of the in-plane lattice parameter $a(T)$, but less well
+pronounced perpendicular to the planes along $c$. Below $T_{\rm C}$ the
+spontaneous magnetostriction follows the square of the magnetization and leads
+to an expansion of the hexagonal layers. Extrapolating to $T\rightarrow$ 0~K we
+obtain a spontaneous in-plane saturation magnetostriction of $\lambda_{{\rm
+sp},a}(T \rightarrow 0) \approx-220 ~\times~10^{-6}$. In the paramagnetic state
+the linear thermal expansion coefficients amount to
+13.9(1)$\times$10$^{-6}$~K$^{-1}$ and to 23.2(2)$\times$10$^{-6}$~K$^{-1}$ for
+the in-plane and out-of-plane direction, respectively, indicating a linear
+volume thermal expansion coefficient of 50.8(4)$\times$10$^{-6}$K$^{-1}$ which
+we use to estimate the volume thermal expansion contribution to the heat
+capacity determined at constant pressure. A Sommerfeld-type linear term in the
+low-temperature heat capacities can be quantitatively ascribed to 2dim
+ferromagnetic magnon excitations.",2401.14050v1
+2024-01-26,First-principles methodology for studying magnetotransport in narrow-gap semiconductors: an application to Zirconium Pentatelluride ZrTe5,"The origin of anomalous resistivity peak and accompanied sign reversal of
+Hall resistivity of ZrTe$_5$ has been under debate for a long time. Although
+various theoretical models have been proposed to account for these intriguing
+transport properties, a systematic study from first principles view is still
+lacking. In this work, we present a first principles calculation combined with
+Boltzmann transport theory to investigate the transport properties in
+narrow-gap semiconductors at different temperatures and doping densities within
+the relaxation time approximation. Regarding the sensitive
+temperature-dependent chemical potential and relaxation time of semiconductors,
+we take proper approximation to simulate these two variables, and then
+comprehensively study the transport properties of ZrTe$_5$ both in the absence
+and presence of an applied magnetic field. Without introducing topological
+phases and correlation interactions, we qualitatively reproduced crucial
+features observed in experiments, including zero-field resistivity anomaly,
+nonlinear Hall resistivity with sign reversal, and non-saturating
+magnetoresistance at high temperatures. Our calculation allows a systematic
+interpretation of the observed properties in terms of multi-carrier and Fermi
+surface geometry. Our method can be extended to other narrow-gap semiconductors
+and further pave the way to explore interesting and novel transport properties
+of this field.",2401.15151v1
+2024-02-16,Spectral variations within solar flare ribbons,"Solar flare ribbons are intense brightenings of principally chromospheric
+material that are responsible for a large fraction of the chromospheric
+emission in solar and stellar flares. We present an on-disc observation of
+flare ribbon substructures in an X9.3-class flare observed by the Swedish 1-m
+Solar Telescope. We identify categories of ribbon substructures seen in the Ca
+II 8542 \AA, H$\alpha$, and Ca II K lines, focusing on their spatial locations
+and their (spectro-)polarimetric properties. Color Collapsed Plotting
+(COCOPLOT) software is used to assist in identifying areas of interest. We
+present five categories of spectral profiles within the general body of the
+flare ribbon: (1) Extremely broadened spectral line profiles, where the
+standard Fabry-Perot interferometer wavelength windows ($\approx 70$ km
+s$^{-1}$) are insufficiently wide to allow for a complete analysis of the
+dynamics and atmospheric conditions. The mechanisms causing this degree of this
+broadening are not yet clearly understood. (2) Long-lived, dense kernels that
+manifest as more saturated chromospheric line profiles with lower signal in
+both Stokes parameters. They are interpreted as footpoints of bunched magnetic
+field loops, whose chromospheric lines form at greater heights than the nearby
+areas. (3) Doppler-shifted leading edges of the flare ribbon in regions that
+transiently display lower Stokes signals due to the emission dominating at
+greater heights in the atmosphere. (4) Condensed coronal rain overlapping the
+flare ribbons in the line of sight, producing exceptionally high Doppler shifts
+near the footpoints...",2402.10611v2
+2024-03-20,Towards Learning Contrast Kinetics with Multi-Condition Latent Diffusion Models,"Contrast agents in dynamic contrast enhanced magnetic resonance imaging allow
+to localize tumors and observe their contrast kinetics, which is essential for
+cancer characterization and respective treatment decision-making. However,
+contrast agent administration is not only associated with adverse health risks,
+but also restricted for patients during pregnancy, and for those with kidney
+malfunction, or other adverse reactions. With contrast uptake as key biomarker
+for lesion malignancy, cancer recurrence risk, and treatment response, it
+becomes pivotal to reduce the dependency on intravenous contrast agent
+administration. To this end, we propose a multi-conditional latent diffusion
+model capable of acquisition time-conditioned image synthesis of DCE-MRI
+temporal sequences. To evaluate medical image synthesis, we additionally
+propose and validate the Fr\'echet radiomics distance as an image quality
+measure based on biomarker variability between synthetic and real imaging data.
+Our results demonstrate our method's ability to generate realistic
+multi-sequence fat-saturated breast DCE-MRI and uncover the emerging potential
+of deep learning based contrast kinetics simulation. We publicly share our
+accessible codebase at https://github.com/RichardObi/ccnet.",2403.13890v1
+2002-03-14,Geometric Scaling above the Saturation Scale,"We show that the evolution equations in QCD predict geometric scaling for
+quark and gluon distribution functions in a large kinematical window, which
+extends above the saturation scale up to momenta $Q^2$ of order $100 {\rm
+GeV}^2$. For $Q^2 < Q^2_s$, with $Q_s$ the saturation momentum, this is the
+scaling predicted by the Colour Glass Condensate and by phenomenological
+saturation models. For $1 \simle \ln(Q^2/Q_s^2) \ll \ln(Q_s^2/\Lambda^2_{\rm
+QCD})$, we show that the solution to the BFKL equation shows approximate
+scaling, with the scale set by $Q_s$. At larger $Q^2$, this solution does not
+scale any longer. We argue that for the intermediate values of $Q^2$ where we
+find scaling, the BFKL rather than the double logarithmic approximation to the
+DGLAP equation properly describes the dynamics. We consider both fixed and
+running couplings, with the scale for running set by the saturation momentum.
+The anomalous dimension which characterizes the approach of the gluon
+distribution function towards saturation is found to be close to, but lower
+than, one half.",0203137v1
+2003-10-30,Saturation and BFKL dynamics in the HERA data at small x,"We show that the HERA data for the inclusive structure function F_2(x,Q^2)
+for x < 0.01 and 0.045 < Q^2 < 45 GeV^2 can be well described within the color
+dipole picture, with a simple analytic expression for the dipole-proton
+scattering amplitude, which is an approximate solution to the non-linear
+evolution equations in QCD. For dipole sizes less than the inverse saturation
+momentum 1/Q_s(x), the scattering amplitude is the solution to the BFKL
+equation in the vicinity of the saturation line. It exhibits geometric scaling
+and scaling violations by the diffusion term. For dipole sizes larger than
+1/Q_s(x), the scattering amplitude saturates to one. The fit involves three
+parameters: the proton radius R, the value x_0 of x at which the saturation
+scale Q_s equals 1GeV, and the logarithmic derivative of the saturation
+momentum \lambda. The value of \lambda extracted from the fit turns out to be
+consistent with a recent calculation using the next-to-leading order BFKL
+formalism.",0310338v1
+2005-03-18,Energy Conservation and Saturation in Small-x Evolution,"Important corrections to BFKL evolution are obtained from non-leading
+contributions and from non-linear effects due to unitarisation or saturation.
+It has been difficult to estimate the relative importance of these effects, as
+NLO effects are most easily accounted for in momentum space while unitarisation
+and saturation are easier in transverse coordinate space. An essential
+component of the NLO contributions is due to energy conservation effects, and
+in this paper we present a model for implementing such effects together with
+saturation in Mueller's dipole evolution formalism. We find that energy
+conservation severely dampens the small-x rise of the gluon density and, as a
+consequence, the onset of saturation is delayed. Using a simple model for the
+proton we obtain a reasonable qualitative description of the x-dependence of F2
+at low Q^2 as measured at HERA even without saturation effects. We also give
+qualitative descriptions of the energy dependence of the cross section for
+gamma*-gamma* and gamma*-nucleus scattering.",0503181v2
+1995-11-30,"Transferring saturation, the finite cover property, and stability","Saturation is (mu,kappa)-transferable in T if and only if there is an
+expansion T_1 of T with |T_1| = |T| such that if M is a mu-saturated model of
+T_1 and |M| \geq kappa then the reduct M|L(T) is kappa-saturated. We
+characterize theories which are superstable without the finite cover property
+(f.c.p.), or without f.c.p. as, respectively those where saturation is
+(aleph_0,lambda)-transferable or (kappa(T),lambda)-transferable for all lambda.
+Further if for some mu \geq |T|, 2^mu > mu^+, stability is equivalent to: or
+all mu \geq |T|, saturation is (\mu,2^mu)-transferable.",9511205v3
+2006-05-17,Saturation points on faces of a rational polyhedral cone,"Different commutative semigroups may have a common saturation. We consider
+distinguishing semigroups with a common saturation based on their ``sparsity''.
+We propose to qualitatively describe sparsity of a semigroup by considering
+which faces of the corresponding rational polyhedral cone have saturation
+points. For a commutative semigroup we give a necessary and sufficient
+condition for determining which faces have saturation points. We also show that
+we can construct a commutative semigroup with arbitrary consistent patterns of
+faces with saturation points.",0605479v4
+2010-05-27,Non-linear evolution in CCFM: The interplay between coherence and saturation,"We solve the CCFM equation numerically in the presence of a boundary
+condition which effectively incorporates the non-linear dynamics. We retain the
+full dependence of the unintegrated gluon distribution on the coherence scale,
+and extract the saturation momentum. The resulting saturation scale is a
+function of both rapidity and the coherence momentum. In Deep Inelastic
+Scattering this will lead to a dependence of the saturation scale on the photon
+virtuality in addition to the usual x-Bjorken dependence. At asymptotic
+energies the interplay between the perturbative non-linear physics, and that of
+the QCD coherence, leads to an interesting and novel dynamics where the
+saturation momentum itself eventually saturates. We also investigate various
+implementations of the ""non-Sudakov"" form factor. It is shown that the
+non-linear dynamics leads to almost identical results for different form
+factors. Finally, different choices of the scale of the running coupling are
+analyzed and implications for the phenomenology are discussed.",1005.5153v1
+2011-07-09,The Search for Super-saturation in Chromospheric Emission,"We investigate if the super-saturation phenomenon observed at X-ray
+wavelengths for the corona, exists in the chromosphere for rapidly rotating
+late-type stars. Moderate resolution optical spectra of fast rotating EUV- and
+X-ray- selected late-type stars were obtained. Stars in alpha Per were observed
+in the northern hemisphere with the Isaac Newton 2.5 m telescope and IDS
+spectrograph. Selected objects from IC 2391 and IC 2602 were observe in the
+southern hemisphere with the Blanco 4m telescope and R-C spectrograph at CTIO.
+Ca II H & K fluxes were measured for all stars in our sample. We find the
+saturation level for Ca II K at log(L_CaK/L_bol) = -4.08. The Ca II K flux does
+not show a decrease as a function of increased rotational velocity or smaller
+Rossby number as observed in the X-ray. This lack of ""super-saturation""
+supports the idea of coronal-stripping as the cause of saturation and
+super-saturation in stellar chromospheres and corona, but the detailed
+underlying mechanism is still under investigation.",1107.1786v1
+2011-09-30,Dynamics of Saturated Energy Condensation in Two-Dimensional Turbulence,"In two-dimensional forced Navier-Stokes turbulence, energy cascades to the
+largest scales in the system to form a pair of coherent vortices known as the
+Bose condensate. We show, both numerically and analytically, that the energy
+condensation saturates and the system reaches a statistically stationary state.
+The time scale of saturation is inversely proportional to the viscosity and the
+saturation energy level is determined by both the viscosity and the force. We
+further show that, without sufficient resolution to resolve the small-scale
+enstrophy spectrum, numerical simulations can give a spurious result for the
+saturation energy level. We also find that the movement of the condensate is
+similar to the motion of an inertial particle with an effective drag force.
+Furthermore, we show that the profile of the saturated coherent vortices can be
+described by a Gaussian core with exponential wings.",1109.6937v2
+2012-08-20,A Simple Proof of Threshold Saturation for Coupled Vector Recursions,"Convolutional low-density parity-check (LDPC) codes (or spatially-coupled
+codes) have now been shown to achieve capacity on binary-input memoryless
+symmetric channels. The principle behind this surprising result is the
+threshold-saturation phenomenon, which is defined by the belief-propagation
+threshold of the spatially-coupled ensemble saturating to a fundamental
+threshold defined by the uncoupled system.
+  Previously, the authors demonstrated that potential functions can be used to
+provide a simple proof of threshold saturation for coupled scalar recursions.
+In this paper, we present a simple proof of threshold saturation that applies
+to a wide class of coupled vector recursions. The conditions of the theorem are
+verified for the density-evolution equations of: (i) joint decoding of
+irregular LDPC codes for a Slepian-Wolf problem with erasures, (ii) joint
+decoding of irregular LDPC codes on an erasure multiple-access channel, and
+(iii) general protograph codes on the BEC. This proves threshold saturation for
+these systems.",1208.4080v3
+2014-06-18,Saturation and elementary equivalence of C*-algebras,"We study the saturation properties of several classes of $C^*$-algebras.
+Saturation has been shown by Farah and Hart to unify the proofs of several
+properties of coronas of $\sigma$-unital $C^*$-algebras; we extend their
+results by showing that some coronas of non-$\sigma$-unital $C^*$-algebras are
+countably degree-$1$ saturated. We then relate saturation of the abelian
+$C^*$-algebra $C(X)$, where $X$ is $0$-dimensional, to topological properties
+of $X$, particularly the saturation of $CL(X)$.",1406.4875v4
+2016-06-20,Consensus with Output Saturations,"This paper consider a standard consensus algorithm under output saturations.
+In the presence of output saturations, global consensus can not be realized due
+to the existence of stable, unachievable equilibrium points for the consensus.
+Therefore, this paper investigates necessary and sufficient initial conditions
+for the achievement of consensus, that is an exact domain of attraction.
+Specifically, this paper considers singe-integrator agents with both fixed and
+time-varying undirected graphs, as well as double-integrator agents with fixed
+undirected graph. Then, we derive that the consensus will be achieved if and
+only if the average of the initial states (only velocities for
+double-integrator agents with homogeneous saturation levels for the outputs) is
+within the minimum saturation level. An extension to the case of fixed directed
+graph is also provided in which an weighted average is required to be within
+the minimum saturation limit.",1606.05980v1
+2016-12-13,Weak Value Amplification Can Outperform Conventional Measurement in the Presence of Detector Saturation,"Weak value amplification (WVA) is a technique in which one can magnify the
+apparent strength of a measurement signal. Some have claimed that WVA can
+outperform more conventional measurement schemes in parameter estimation.
+Nonetheless, a significant body of theoretical work has challenged this
+perspective, suggesting WVA to be fundamentally sub-optimal. Optimal
+measurements may not be practical, however. Two practical considerations that
+have been conjectured to afford a benefit to WVA over conventional measurement
+are certain types of noise and detector saturation. Here, we report a
+theoretical study of the role of saturation and pixel noise in WVA-based
+measurement, in which we carry out a Bayesian analysis of the Fisher
+information available using a saturable, pixelated, digitized, and/or noisy
+detector. We draw two conclusions: first, that saturation alone does not confer
+an advantage to the WVA approach over conventional measurement, and second,
+that WVA can outperform conventional measurement when saturation is combined
+with intrinsic pixel noise and/or digitization.",1612.04327v1
+2017-01-11,The Saturation Number of Induced Subposets of the Boolean Lattice,"Given a poset $P$, a family $F$ of elements in the Boolean lattice is said to
+be $P$-saturated if (1) $F$ contains no copy of $P$ as a subposet and (2) every
+proper superset of $F$ contains a copy of $P$ as a subposet. The maximum size
+of a $P$-saturated family is denoted by $La(n,P)$, which has been studied for a
+number of choices of $P$. The minimum size of a $P$-saturated family,
+$sat(n,P)$, was introduced by Gerbner et al. (2013), and parallels the deep
+literature on the saturation function for graphs.
+  We introduce and study the concept of saturation for induced subposets. As
+opposed to induced saturation in graphs, the above definition of saturation for
+posets extends naturally to the induced setting. We give several exact results
+and a number of bounds on the induced saturation number for several small
+posets. We also use a transformation to the biclique cover problem to prove a
+logarithmic lower bound for a rich infinite family of target posets.",1701.03010v2
+2018-02-18,CGC/saturation approach: an impact-parameter dependent model for diffraction production in DIS,"In the paper we discussed the evolution equations for diffractive production
+in the framework of CGC/saturation approach, and found the analytical solutions
+for several kinematic regions. The most impressive features of these solutions
+are, that diffractive production does not exibit geometric scaling behaviour
+i.e. being a function of one variable.
+  Based on these solutions, we suggest an impact parameter dependent saturation
+model, which is suitable for describing diffraction production both deep in the
+saturation region, and in the vicinity of the saturation scale. Using the model
+we attempted to fit the combined data on diffraction production from H1 and
+ZEUS collaborations. We found that we are able describe both
+  $x_\pom$ and $\beta$ dependence, as well as $Q$ behavior of the measured
+cross sections. In spite of the sufficiently large $\chi^2/d.o.f.$ we believe
+that our description provides an initial impetus to find a fit of the
+experimental data, based on the solution of the CGC/saturation equation, rather
+than on describing the diffraction system in simplistic manner, assuming that
+only quark-antiquark pair and one extra gluons, are produced.",1802.06344v1
+2018-02-19,Bulk hydrodynamic stability and turbulent saturation in compressing hot spots,"For hot spots compressed at constant velocity, we give a hydrodynamic
+stability criterion that describes the expected energy behavior of non-radial
+hydrodynamic motion for different classes of trajectories (in $\rho R$ --- $T$
+space). For a given compression velocity, this criterion depends on $\rho R$,
+$T$, and $\mathrm{d}T/\mathrm{d}(\rho R)$ (the trajectory slope), and applies
+point-wise, so that the expected behavior can be determined instantaneously
+along the trajectory. Among the classes of trajectories are those where the
+hydromotion is guaranteed to decrease, and those where the hydromotion is
+bounded by a saturated value. We calculate this saturated value, and find the
+compression velocities for which hydromotion may be a substantial fraction of
+hot-spot energy at burn time. The Lindl ""attractor"" trajectory (Lindl, 1995) is
+shown to experience non-radial hydrodynamic energy that grows towards this
+saturated state. Comparing the saturation value to available detailed 3D
+simulation results, we find that the fluctuating velocities in these
+simulations reach substantial fractions of the saturated value.",1802.06817v1
+2018-05-15,On the Dihadron Angular Correlations in Forward $pA$ collisions,"Dihadron angular correlations in forward $pA$ collisions have been considered
+as one of the most sensitive observables to the gluon saturation effects. In
+general, both parton shower effects and saturation effects are responsible for
+the back-to-back dihadron angular de-correlations. With the recent progress in
+the saturation formalism, we can incorporate the parton shower effect by adding
+the corresponding Sudakov factor in the saturation framework. In this paper, we
+carry out the first detailed numerical study in this regard, and find a very
+good agreement with previous RHIC $pp$ and $dAu$ data. This study can help us
+to establish a baseline in $pp$ collisions which contains little saturation
+effects, and further make predictions for dihadron angular correlations in
+$pAu$ collisions, which will allow to search for the signal of parton
+saturation.",1805.05712v1
+2018-09-19,Direct Reconstruction of Saturated Samples in Band-Limited OFDM Signals,"Given a set of samples, a few of them being possibly saturated, we propose an
+efficient algorithm in order to cancel saturation while reconstructing
+band-limited signals. Our method satisfies a minimum-loss constraint and relies
+on sinc-related bases. It involves matrix inversion and is a direct,
+non-iterative approach. It consists of two main steps: (i) regression, to
+estimate the expansion coefficients of the signal model; (ii) interpolation, to
+restore an estimated value for those samples that are saturated. Because the
+proposed method is free from tuning parameters, it is hardware-friendly and we
+expect that it will be particularly useful in the context of orthogonal
+frequency-division multiplexing. There, the high peak-to-average power ratio of
+the transmitted signal results in a challenging decoding stage in the presence
+of saturation, which causes significant decoding errors due to the nonlinearity
+of amplifiers and receivers, ultimately resulting in band distortion and
+information loss. Our experiments on realistic simulations confirm that our
+proposed reconstruction of the saturated samples can significantly reduce
+transmission errors in modern high-throughput digital-communication receivers.",1809.07188v1
+2019-05-18,On greedy heuristics for computing D-efficient saturated subsets,"Let $\mathcal{F}$ be a set consisting of $n$ real vectors of dimension $m
+\leq n$. For any saturated, i.e., $m$-element, subset $\mathcal{S}$ of
+$\mathcal{F}$, let $\mathrm{vol}(\mathcal{S})$ be the volume of the
+parallelotope formed by the vectors of $\mathcal{S}$. A set $\mathcal{S}^*$ is
+called a $D$-optimal saturated subset of $\mathcal{F}$, if it maximizes
+$\mathrm{vol}(\mathcal{S})$ among all saturated subsets of $\mathcal{F}$. In
+this paper, we propose two greedy heuristics for the construction of saturated
+subsets performing well with respect to the criterion of $D$-optimality: an
+improvement of the method suggested by Galil and Kiefer for the initiation of
+$D$-optimal experimental design algorithms, and a modification of the
+Kumar-Yildirim method, the original version of which was proposed for the
+initiation of the minimum-volume enclosing ellipsoid algorithms. We provide
+geometric and analytic insights into the two methods, and compare them to the
+commonly used random and regularized greedy heuristics. We also suggest
+variants of the greedy methods for a large set $\mathcal{F}$, for the
+construction of $D$-efficient non-saturated subsets, and for alternative
+optimality criteria.",1905.07647v1
+2020-04-07,egg: Fast and Extensible Equality Saturation,"An e-graph efficiently represents a congruence relation over many
+expressions. Although they were originally developed in the late 1970s for use
+in automated theorem provers, a more recent technique known as equality
+saturation repurposes e-graphs to implement state-of-the-art, rewrite-driven
+compiler optimizations and program synthesizers. However, e-graphs remain
+unspecialized for this newer use case. Equality saturation workloads exhibit
+distinct characteristics and often require ad-hoc e-graph extensions to
+incorporate transformations beyond purely syntactic rewrites.
+  This work contributes two techniques that make e-graphs fast and extensible,
+specializing them to equality saturation. A new amortized invariant restoration
+technique called rebuilding takes advantage of equality saturation's distinct
+workload, providing asymptotic speedups over current techniques in practice. A
+general mechanism called e-class analyses integrates domain-specific analyses
+into the e-graph, reducing the need for ad hoc manipulation.
+  We implemented these techniques in a new open-source library called egg. Our
+case studies on three previously published applications of equality saturation
+highlight how egg's performance and flexibility enable state-of-the-art results
+across diverse domains.",2004.03082v3
+2020-05-11,$P_{n}$-induced-saturated graphs exist for all $n \geq 6$,"Let $P_{n}$ be a path graph on $n$ vertices. We say that a graph $G$ is
+$P_{n}$-induced-saturated if $G$ contains no induced copy of $P_{n}$, but
+deleting any edge of $G$ as well as adding to $G$ any edge of $G^{c}$ creates
+such a copy. Martin and Smith (2012) showed that there is no
+$P_{4}$-induced-saturated graph. On the other hand, there trivially exist
+$P_{n}$-induced-saturated graphs for $n=2,3$. Axenovich and Csik\'{o}s (2019)
+ask for which integers $n \geq 5$ do there exist $P_{n}$-induced-saturated
+graphs. R\""{a}ty (2019) constructed such a graph for $n=6$, and Cho, Choi and
+Park (2019) later constructed such graphs for all $n=3k$ for $k \geq 2$. We
+show by a different construction that $P_{n}$-induced-saturated graphs exist
+for all $n \geq 6$, leaving only the case $n=5$ open.",2005.05033v2
+2021-03-11,Two-phase hyperbolic model for porous media saturated with a viscous fluid and its application to wavefields simulation,"We derive and study a new hyperbolic two-phase model of a porous deformable
+medium saturated by a viscous fluid. The governing equations of the model are
+derived in the framework of Symmetric Hyperbolic Thermodynamically Compatible
+(SHTC) systems and by generalizing the unified hyperbolic model of continuum
+fluid and solid mechanics. Similarly to the unified model, the presented model
+takes into account the viscosity of the saturating fluid through a hyperbolic
+reformulation. The model accounts for such dissipative mechanisms as
+interfacial friction and viscous dissipation of the saturated fluid. Using the
+presented nonlinear finite-strain SHTC model, the governing equations for the
+propagation of small-amplitude waves in a porous medium saturated with a
+viscous fluid are derived. As in the conventional Biot theory of porous media,
+three types of waves can be found: fast and slow compression waves and shear
+waves. It turns out that the shear wave attenuates rapidly due to the viscosity
+of the saturating fluid, and this wave is difficult to see in typical test
+cases. However, some test cases are presented in which shear waves can be
+observed in the vicinity of interfaces between regions with different porosity.",2103.06969v1
+2021-05-14,Defect Saturation in a Rapidly Quenched Bose Gas,"We investigate the saturation of defect density in an atomic Bose gas rapidly
+cooled into a superfluid phase. The number of quantum vortices, which are
+spontaneously created in the quenched gas, exhibits a Poissonian distribution
+not only for a slow quench in the Kibble-Zurek (KZ) scaling regime but also for
+a fast quench in which case the mean vortex number is saturated. This shows
+that the saturation is not caused by destructive vortex collisions, but by the
+early-time coarsening in an emerging condensate, which is further supported by
+the observation that the condensate growth lags the quenching in the saturation
+regime. Our results demonstrate that the defect saturation is an effect beyond
+the KZ mechanism, opening a path for studying critical phase transition
+dynamics using the defect number distribution.",2105.06601v2
+2021-06-03,Predicting water flow in fully and partially saturated porous media: a new fractal-based permeability model,"Predicting the permeability of porous media in saturated and partially
+saturated conditions is of crucial importance in many geo-engineering areas,
+from water resources to vadose zone hydrology or contaminant transport
+predictions. Many models have been proposed in the literature to estimate the
+permeability from properties of the porous media such as porosity, grain size
+or pore size. In this study, we develop a model of the permeability for porous
+media saturated by one or two fluid phases with all physically-based parameters
+using a fractal upscaling technique. The model is related to microstructural
+properties of porous media such as fractal dimension for pore space, fractal
+dimension for tortuosity, porosity, maximum radius, ratio of minimum pore
+radius and maximum pore radius, water saturation and irreducible water
+saturation. The model is favorably compared to existing and widely used models
+from the literature. Then, comparison with published experimental data for both
+unconsolidated and consolidated samples, we show that the proposed model
+estimate the permeability from the medium properties very well.",2106.01670v1
+2021-09-16,Saturated and linear isometric transfer systems for cyclic groups of order $p^mq^n$,"Transfer systems are combinatorial objects which classify $N_\infty$ operads
+up to homotopy. By results of A. Blumberg and M. Hill, every transfer system
+associated to a linear isometries operad is also saturated (closed under a
+particular two-out-of-three property). We investigate saturated and linear
+isometric transfer systems with equivariance group $C_{p^mq^n}$, the cyclic
+group of order $p^mq^n$ for $p,q$ distinct primes and $m,n\ge 0$. We give a
+complete enumeration of saturated transfer systems for $C_{p^mq^n}$. We also
+prove J. Rubin's saturation conjecture for $C_{pq^n}$; this says that every
+saturated transfer system is realized by a linear isometries operad for $p,q$
+sufficiently large (greater than $3$ in this case).",2109.08210v1
+2021-09-27,Recent advances of MXene saturable absorber for near-infrared mode-locked fiber laser,"To date, MXene has been discovered for its viability as alternatives to
+conventional saturable absorber such as carbon nanotube and graphene. The
+characteristics of high nonlinear saturable absorption, astounding modulation
+depth, flexible bandgap tunability, and high electron density near Fermi level
+are the fundamentals of the MXene as an excellent saturable absorber candidate.
+In particular, the research effort contributed to MXene in nonlinear ul-trafast
+optics are extensively growing because MXene comprises one of the largest
+families in 2D nanomaterials that provides huge combination possibilities by
+forming a class of metal carbide or metal nitride with 2D layered structure.
+Herein, this review summarizes the recent development on synthesis and material
+characterization of the MXene, the studies on its nonlinear saturable
+absorption and the application of the MXene saturable absorber in near-infrared
+mode-locked fiber laser. Finally, some issues and challenges as well as future
+perspectives of this novel material are discussed.",2109.13011v1
+2021-11-09,First saturation correction in high energy proton-nucleus collisions: Part III. Ensemble averaging,"In high energy proton-nucleus collisions, the gluon saturation effects from
+the nucleus are fully incorporated into the light-like Wilson lines. The gluon
+saturation effects from the proton, which are anticipated to be important
+either in the extreme high energy limit or towards the dense-dense
+(nucleus-nucleus) collision regimes, have been studied perturbatively within
+the Color Glass Condensate effective theory in previous papers of this series.
+A configuration-by-configuration expression for the single inclusive semi-hard
+gluon production including the first saturation correction was obtained. In
+this paper, we perform ensemble averaging in the McLerran-Venugopalan model and
+the Dipole Approximation. We find that, in the saturation correction, the
+effects of the initial state interactions are negligible while the final state
+interactions play most important role and give a positive-valued contribution
+to the semi-hard gluon spectrum. Furthermore, we show that the single gluon
+spectrum scales approximately $1/k_{\perp}^{4}$ at small $k_{\perp}$,
+suggesting that a resummation of higher order saturation corrections is
+required to regulate the infrared region of the gluon spectrum.",2111.05304v2
+2021-12-13,Bistable soliton switching dynamics in a $\mathcal{PT}$-symmetric coupler with saturable nonlinearity,"We investigate the switching dynamics in a $\mathcal{PT}$-symmetric fiber
+coupler composed of a saturable nonlinear material as the core. In such a
+saturable nonlinear medium, bistable solitons may evolve due to the balance
+between dispersion and saturable nonlinearity, which we extend in the context
+of the $\mathcal{PT}$-symmetric coupler. Our investigations of power-controlled
+and phase-sensitive switching show richer soliton switching dynamics than the
+currently existing conventional counterparts, which may lead to ultrafast and
+efficient all-optical switching dynamics at very low power owing to the
+combined effects of $\mathcal{PT}$ symmetry and saturable nonlinearity. In
+addition to the input power, the relative phase of the input solitons and
+saturable coefficient are additional controlling parameters that efficiently
+tailor the switching dynamics. Also, we provide a suitable range of system and
+pulse parameters that would be helpful for the practical realization of the
+coupler to use in all-optical switching devices and photonic circuits. Finally,
+we develop a variational approach to analytically investigate the switching
+dynamics in such $\mathcal{PT}$-symmetric couplers that excellently predicts
+the numerical findings.",2112.06684v2
+2022-03-10,Saturation of Ordered Graphs,"Recently, the saturation problem of $0$-$1$ matrices gained a lot of
+attention. This problem can be regarded as a saturation problem of ordered
+bipartite graphs. Motivated by this, we initiate the study of the saturation
+problem of ordered and cyclically ordered graphs.
+  We prove that dichotomy holds also in these two cases, i.e., for a
+(cyclically) ordered graph its saturation function is either bounded or linear.
+We also determine the order of magnitude for large classes of (cyclically)
+ordered graphs, giving infinite many examples exhibiting both possible
+behaviours, answering a problem of P\'alv\""olgyi. In particular, in the ordered
+case we define a natural subclass of ordered matchings, the class of linked
+matchings, and we start their systematic study, concentrating on linked
+matchings with at most three links and prove that many of them have bounded
+saturation function.
+  In both the ordered and cyclically ordered case we also consider the
+semisaturation problem, where dichotomy holds as well and we can even fully
+characterize the graphs that have bounded semisaturation function.",2203.05307v1
+2022-11-03,Harmonics of Parton Saturation in Lepton-Jet Correlations at the EIC,"Parton saturation is one of the most intriguing phenomena in the high energy
+nuclear physics research frontier, especially in the upcoming era of the
+Electron-Ion Collider (EIC). The lepton-jet correlation in deep inelastic
+scattering provides us with a new gateway to the parton saturation at the EIC.
+In particular, we demonstrate that azimuthal angle anisotropies of the
+lepton-jet correlation are sensitive to the strength of the saturation momentum
+in the EIC kinematic region. In contrast to the predictions based on the
+collinear framework calculation, significant nuclear modification of the
+anisotropies is observed when we compare the saturation physics results in e +
+p and e + Au scatterings. By measuring these harmonic coefficients at the EIC,
+one can conduct quantitative analysis in different collisional systems and
+unveil compelling evidence for saturation effects.",2211.01647v4
+2022-11-16,The rainbow saturation number is linear,"Given a graph $H$, we say that an edge-coloured graph $G$ is $H$-rainbow
+saturated if it does not contain a rainbow copy of $H$, but the addition of any
+non-edge in any colour creates a rainbow copy of $H$. The rainbow saturation
+number $\text{rsat}(n,H)$ is the minimum number of edges among all $H$-rainbow
+saturated edge-coloured graphs on $n$ vertices. We prove that for any non-empty
+graph $H$, the rainbow saturation number is linear in $n$, thus proving a
+conjecture of Gir\~{a}o, Lewis, and Popielarz. In addition, we also give an
+improved upper bound on the rainbow saturation number of the complete graph,
+disproving a second conjecture of Gir\~{a}o, Lewis, and Popielarz.",2211.08589v1
+2022-12-07,A Decision Diagram Operation for Reachability,"Saturation is considered the state-of-the-art method for computing fixpoints
+with decision diagrams. We present a relatively simple decision diagram
+operation called REACH that also computes fixpoints. In contrast to saturation,
+it does not require a partitioning of the transition relation. We give
+sequential algorithms implementing the new operation for both binary and
+multi-valued decision diagrams, and moreover provide parallel counterparts. We
+implement these algorithms and experimentally compare their performance against
+saturation on 692 model checking benchmarks in different languages. The results
+show that the REACH operation often outperforms saturation, especially on
+transition relations with low locality. In a comparison between parallelized
+versions of REACH and saturation we find that REACH obtains comparable speedups
+up to 16 cores, although falls behind saturation at 64 cores. Finally, in a
+comparison with the state-of-the-art model checking tool ITS-tools we find that
+REACH outperforms ITS-tools on 29% of models, suggesting that REACH can be
+useful as a complementary method in an ensemble tool.",2212.03684v1
+2023-02-13,Restoring the saturation response of a PMT using pulse-shape and artificial-neural-networks,"The linear response of a photomultiplier tube (PMT) is a required property
+for photon counting and reconstruction of the neutrino energy. The linearity
+valid region and the saturation response of PMT were investigated using a
+linear-alkyl-benzene (LAB)-based liquid scintillator. A correlation was
+observed between the two different saturation responses, with pulse-shape
+distortion and pulse-area decrease. The observed pulse-shape provides useful
+information for the estimation of the linearity region relative to the
+pulse-area. This correlation-based diagnosis allows an ${in}$-${situ}$
+estimation of the linearity range, which was previously challenging. The
+measured correlation between the two saturation responses was employed to train
+an artificial-neural-network (ANN) to predict the decrease in pulse-area from
+the observed pulse-shape. The ANN-predicted pulse-area decrease enables the
+prediction of the ideal number of photoelectrons irrelevant to the saturation
+behavior. This pulse-shape-based machine learning technique offers a novel
+method for restoring the saturation response of PMTs.",2302.06170v3
+2023-02-13,Saturation of spiral instabilities in disk galaxies,"Spiral density waves can arise in galactic disks as linear instabilities of
+the underlying stellar distribution function. Such an instability grows
+exponentially in amplitude at some fixed growth rate $\beta$ before saturating
+nonlinearly. However, the mechanisms behind saturation, and the resulting
+saturated spiral amplitude, have received little attention. Here we argue that
+one important saturation mechanism is the nonlinear trapping of stars near the
+spiral's corotation resonance. Under this mechanism, we show analytically that
+an $m$-armed spiral instability will saturate when the libration frequency of
+resonantly trapped orbits reaches $\omega_\mathrm{lib} \sim \mathrm{a\,\,
+few}\times m^{1/2} \beta$. For a galaxy with a flat rotation curve this implies
+a maximum relative spiral surface density $\vert \delta\Sigma/\Sigma_0\vert
+\sim \mathrm{a\,\,few} \times (\beta/\Omega_\mathrm{p})^2 \cot \alpha$, where
+$\Omega_\mathrm{p}$ is the spiral pattern speed and $\alpha$ is its pitch
+angle. This result is in reasonable agreement with recent $N$-body simulations,
+and suggests that spirals driven by internally-generated instabilities reach
+relative amplitudes of at most a few tens of percent; higher amplitude spirals,
+like in M51 and NGC 1300, are likely caused by very strong bars and/or tidal
+perturbations.",2302.06602v2
+2023-04-04,Route to stabilize cubic gauche polynitrogen to ambient conditions via surface-saturation by hydrogen,"Cubic gauche polynitrogen (cg-N) is an attractive high-energy density
+material. However, high-pressure synthesized cg-N will decompose at
+low-pressure and cannot exist at ambient conditions. Here, the stabilities of
+cg-N surfaces with and without saturations at different pressures and
+temperatures are investigated systematically. Pristine surfaces at 0 GPa are
+very brittle and will decompose at 300 K, especially (1 1 0) surface will
+collapse completely just after structural relaxation, whereas the
+decompositions of surfaces can be suppressed by applying pressure, indicating
+that surface instability causes the cg-N decomposition at low-pressure. Due to
+the saturation of dangling bonds and transferring electrons to the surfaces,
+saturation with H can stabilize surfaces at ambient conditions, while OH
+saturation cannot because of getting electrons from the surfaces. An acidic
+environment or surface saturation with less electronegative adsorbates is more
+favorable for the stability of polymerized nitrogen.",2304.01755v1
+2023-05-18,Weak saturation in graphs: a combinatorial approach,"The weak saturation number $\mathrm{wsat}(n,F)$ is the minimum number of
+edges in a graph on $n$ vertices such that all the missing edges can be
+activated sequentially so that each new edge creates a copy of $F$. A usual
+approach to prove a lower bound for the weak saturation number is algebraic: if
+it is possible to embed edges of $K_n$ in a vector space in a certain way
+(depending on $F$), then the dimension of the subspace spanned by the images of
+the edges of $K_n$ is a lower bound for the weak saturation number. In this
+paper, we present a new combinatorial approach to prove lower bounds for weak
+saturation numbers that allows to establish worst-case tight (up to constant
+additive terms) general lower bounds as well as to get exact values of the weak
+saturation numbers for certain graph families. It is known (Alon, 1985) that,
+for every $F$, there exists $c_F$ such that $\mathrm{wsat}(n,F)=c_Fn(1+o(1))$.
+Our lower bounds imply that all values in the interval
+$\left[\frac{\delta}{2}-\frac{1}{\delta+1},\delta-1\right]$ with step size
+$\frac{1}{\delta+1}$ are achievable by $c_F$ (while any value outside this
+interval is not achievable).",2305.11043v2
+2023-05-27,Super resolution computational saturated absorption microscopy,"Imaging beyond the diffraction limit barrier has attracted wide attention due
+to the ability to resolve image features that were previously hidden. Of the
+various super-resolution microscopy techniques available, a particularly simple
+method called saturated excitation microscopy (SAX) requires only a simple
+modification of a laser scanning microscope where the illumination beam power
+is sinusoidally modulated and driven into saturation. SAX images are extracted
+from harmonics of the modulation frequency and exhibit improved spatial
+resolution. Unfortunately, this elegant strategy is hindered by the incursion
+of shot noise that prevents high resolution imaging in many realistic
+scenarios. Here, we demonstrate a new technique for super resolution imaging
+that we call computational saturated absorption (CSA) in which a joint
+deconvolution is applied to a set of images with diversity in spatial frequency
+support among the point spread functions used in the image formation with
+saturated laser scanning fluorescence microscope. CSA microscopy allows access
+to the high spatial frequency diversity in a set of saturated effective point
+spread functions, while avoiding image degradation from shot noise.",2305.17348v1
+2023-07-23,Saturating automata for game semantics,"Saturation is a fundamental game-semantic property satisfied by strategies
+that interpret higher-order concurrent programs. It states that the strategy
+must be closed under certain rearrangements of moves, and corresponds to the
+intuition that program moves (P-moves) may depend only on moves made by the
+environment (O-moves).
+  We propose an automata model over an infinite alphabet, called saturating
+automata, for which all accepted languages are guaranteed to satisfy a closure
+property mimicking saturation.
+  We show how to translate the finitary fragment of Idealized Concurrent Algol
+(FICA) into saturating automata, confirming their suitability for modelling
+higher-order concurrency. Moreover, we find that, for terms in normal form, the
+resultant automaton has linearly many transitions and states with respect to
+term size, and can be constructed in polynomial time. This is in contrast to
+earlier attempts at finding automata-theoretic models of FICA, which did not
+guarantee saturation and involved an exponential blow-up during translation,
+even for normal forms.",2307.12302v2
+2023-08-02,Injection-Limited and Space-Charge-Limited Conduction in Wide Bandgap Semiconductors with Velocity Saturation Effect,"Carrier conduction in wide bandgap semiconductors (WBS) often exhibits
+velocity saturation at the high-electric field regime. How such effect
+influences the transition between contact-limited and space-charge-limited
+current in a two-terminal device remains largely unexplored thus far. Here, we
+develop a generalized carrier transport model that includes contact-limited
+field-induced carrier injection, space charge, carrier scattering and velocity
+saturation effect. The model reveals various transitional behaviors in the
+current-voltage characteristics, encompassing Fowler-Nordheim emission,
+trap-free Mott-Gurney (MG) SCLC and \emph{velocity-saturated SCLC}. Using GaN,
+6H-SiC and 4H-SiC WBS as examples, we show that the velocity-saturated SCLC
+completely dominates the high-voltage ($10^2 \sim 10^4$ V) transport for
+typical sub-$\mu$m GaN and SiC diodes, thus unravelling velocity-saturated SCLC
+as a central transport mechanism in WBG electronics.",2308.00955v1
+2024-01-30,$G$-complete reducibility and saturation,"Let $H \subseteq G$ be connected reductive linear algebraic groups defined
+over an algebraically closed field of characteristic $p> 0$. In our first
+principal theorem we show that if a closed subgroup $K$ of $H$ is
+$H$-completely reducible, then it is also $G$-completely reducible in the sense
+of Serre, under some restrictions on $p$, generalising the known case for $G =
+GL(V)$. Our second main theorem shows that if $K$ is $H$-completely reducible,
+then the saturation of $K$ in $G$ is completely reducible in the saturation of
+$H$ in $G$ (which is again a connected reductive subgroup of $G$), under
+suitable restrictions on $p$, again generalising the known instance for $G =
+GL(V)$. We also study saturation of finite subgroups of Lie type in $G$. We
+show that saturation is compatible with standard Frobenius endomorphisms, and
+we use this to generalise a result due to Nori from 1987 in case $G = GL(V)$.",2401.16927v3
+2024-03-19,Magnetic field morphology and evolution in the Central Molecular Zone and its effect on gas dynamics,"The interstellar medium in the Milky Way's Central Molecular Zone (CMZ) is
+known to be strongly magnetised, but its large-scale morphology and impact on
+the gas dynamics are not well understood. We explore the impact and properties
+of magnetic fields in the CMZ using three-dimensional non-self gravitating
+magnetohydrodynamical simulations of gas flow in an external Milky Way barred
+potential. We find that: (1) The magnetic field is conveniently decomposed into
+a regular time-averaged component and an irregular turbulent component. The
+regular component aligns well with the velocity vectors of the gas everywhere,
+including within the bar lanes. (2) The field geometry transitions from
+parallel to the Galactic plane near $z=0$ to poloidal away from the plane. (3)
+The magneto-rotational instability (MRI) causes an in-plane inflow of matter
+from the CMZ gas ring towards the central few parsecs of $0.01-0.1$ M$_\odot$
+yr$^{-1}$ that is absent in the unmagnetised simulations. However, the magnetic
+fields have no significant effect on the larger-scale bar-driven inflow that
+brings the gas from the Galactic disc into the CMZ. (4) A combination of bar
+inflow and MRI-driven turbulence can sustain a turbulent vertical velocity
+dispersion of $\sigma_z \simeq 5$ km s$^{-1}$ on scales of $20$ pc in the CMZ
+ring. The MRI alone sustains a velocity dispersion of $\sigma_z \simeq 3$ km
+s$^{-1}$. Both these numbers are lower than the observed velocity dispersion of
+gas in the CMZ, suggesting that other processes such as stellar feedback are
+necessary to explain the observations. (5) Dynamo action driven by differential
+rotation and the MRI amplifies the magnetic fields in the CMZ ring until they
+saturate at a value that scales with the average local density as $B \simeq 102
+(n/10^3 cm^{-3})^{0.33}$ $\mu$G. Finally, we discuss the implications of our
+results within the observational context in the CMZ.",2403.13048v1
+2003-05-09,Numerical Study of Compressible Magnetohydrodynamic Turbulence in Two Dimensions,"We have studied forced turbulence of compressible magnetohydrodynamic (MHD)
+flows through two-dimensional simulations with different numerical resolutions.
+First, hydrodynamic turbulence with Mach number $<M_s >_{\rm init} \equiv < v
+>_{\rm rms}/ c_s = 1$ and density compression ${< \delta\rho / \rho >}_{\rm
+rms} \simeq 0.45$ was generated by enforcing a random force. Then, initial,
+uniform magnetic fields of various strengths were added with Alfv\'enic Mach
+number $<M_A >_{\rm init} \equiv < v >_{\rm rms} / c_{A, {\rm init}} \gg 1$. An
+isothermal equation of state was employed, and no explicit dissipation was
+included. After the MHD turbulence is saturated, the resulting flows are
+categorized as very weak field (VWF), weak field (WF), and strong field (SF)
+classes, which have $<M_A > \equiv < v >_{\rm rms} / < c_A >_{\rm rms} \gg 1$,
+$<M_A > > 1$, and $<M_A > \sim 1$, respectively. Not only in the SF regime but
+also in the WF regime, turbulent transport is suppressed by the magnetic field.
+In the SF cases, the energy power spectra in the inertial range, although no
+longer power-law, exhibit a range with slopes close to $\sim1.5$, hinting the
+Iroshnikov-Kraichnan spectrum. Our simulations were able to produce the SF
+class behaviors only with high resolution of at least $1024^2$ grid cells. The
+specific requirements for the simulation of the SF class should depend on the
+code (and the numerical scheme) as well as the initial setup, but our results
+do indicate that very high resolution would be required for converged results
+in simulation studies of MHD turbulence.",0305165v1
+2006-03-01,Chandra X-Ray Observations of Young Clusters. III. NGC 2264 and the Orion Flanking Fields,"Chandra observations of solar-like pre-main sequence (PMS) stars in the Orion
+Flanking Fields (age ~1 Myr) and NGC 2264 (~3 Myr) are compared with the
+results of the COUP survey of similar objects in the ONC (~0.5 Myr). The
+correlations between log Lx and mass found for PMS stars on convective tracks
+in these clusters are consistent with the relationships found for the ONC,
+indicating little change in the median values of either log Lx or log Lx/Lbol
+during the first ~3-5 Myr of evolution down convective tracks. The fraction of
+stars with extreme values of Lx, more than 10 times higher than the average for
+a given Lbol or with log Lx/Lbol greater than the canonical saturation value of
+-2.9, is however larger by a factor of two in the younger ONC when compared
+with the Orion FF and NGC 2264.
+  PMS stars in NGC 2264 on radiative tracks have Lx/Lbol values that are
+systematically lower by a factor of ~10 times than those found for stars of
+similar mass on convective tracks. The dramatic decrease in flux from
+convective to radiative phases of PMS evolution is likely related to major
+structural changes which influence the efficiency of magnetic field generation
+and thus the level of magnetic activity.
+  As in the ONC, we find that stars with measured periods have, on average,
+higher X-ray luminosities. However, there is a wide range in Lx and Lx/Lbol for
+both periodic and non-periodic stars of similar mass. Among stars with measured
+periods, the level of X-ray emission does not correlate with the rotation rate.
+  For this data set, we find no statistically significant correlation between
+X-ray flux and (a) the presence or absence of circumstellar accretion disks, or
+(b) disk accretion rates as assessed from ultraviolet excesses.",0603027v1
+2001-09-10,"Novel features of Josephson flux-flow in Bi-2212: contribution of in-plane dissipation, coherent response to mm-wave radiation, size effect","We studied Josephson flux-flow (JFF) in Bi-2212 stacks fabricated from single
+crystal whiskers by focused ion beam technique. For long junctions with the
+in-plane sizes 30 x 2 (mu)m^2, we found considerable contribution of the
+in-plane dissipation to the JFF resistivity, (rho)_(Jff), at low temperatures.
+According to recent theory [A. Koshelev, Phys. Rev. B62, R3616 (2000)] that
+results in quadratic type dependence of (rho)_(Jff)(B) with the following
+saturation. The I-V characteristics in JFF regime also can be described
+consistently by that theory. In JFF regime we found Shapiro-step response to
+the external mm-wave radiation. The step position is proportional to the
+frequency of applied microwaves and corresponds to the Josephson emission from
+all the 60 intrinsic junctions of the stack being synchronized. That implies
+the coherence of the JFF over the whole thickness of the stack and demonstrates
+possibility of synchronization of intrinsic junctions by magnetic field. We
+also found a threshold character of an appearance of the JFF branch on the I-V
+characteristic with the increase of magnetic field, the threshold field B_t
+being scaled with the junction size perpendicular to the field L (L = 30-1.4
+(mu)m), as B_t = (Phi)_0/Ls, where (Phi)_0 is flux quantum, s is the interlayer
+spacing. On the I-V characteristics of small stacks in the JFF regime we found
+Fiske-step features associated with resonance of Josephson radiation with the
+main resonance cavity mode in transmission line formed by stack.",0109181v1
+2004-10-22,Formation of convective cells in the scrape-off layer of the CASTOR tokamak,"Understanding of the scrape-off layer (SOL) physics in tokamaks requires
+diagnostics with sufficient temporal and spatial resolution. This contribution
+describes results of experiments performed in the SOL of the CASTOR tokamak
+(R=40 cm, a = 6 cm) by means of a ring of 124 Langmuir probes surrounding the
+whole poloidal cross section. The individual probes measure either the ion
+saturation current of the floating potential with the spatial resolution up to
+3 mm. Experiments are performed in a particular magnetic configuration,
+characterized by a long parallel connection length in the SOL, L_par ~q2piR. We
+report on measurements in discharges, where the edge electric field is modified
+by inserting a biased electrode into the edge plasma. In particular, a complex
+picture is observed, if the biased electrode is located inside the SOL. The
+poloidal distribution of the floating potential appears to be strongly
+non-uniform at biasing. The peaks of potential are observed at particular
+poloidal angles. This is interpreted as formation of a biased flux tube, which
+emanates from the electrode along the magnetic field lines and snakes q times
+around the torus. The resulting electric field in the SOL is 2-dimensional,
+having the radial as well as the poloidal component. It is demonstrated that
+the poloidal electric field E_pol convects the edge plasma radially due to the
+E_pol x B_T drift either inward or outward depending on its sign. The
+convective particle flux is by two orders of magnitude larger than the
+fluctuation-induced one and consequently dominates.",0410208v1
+2007-05-24,MHD simulations of the magnetorotational instability in a shearing box with zero net flux. I. The issue of convergence,"We study the properties of MHD turbulence driven by the magnetorotational
+instability (MRI) in accretion disks. We adopt the local shearing box model and
+focus on the special case for which the initial magnetic flux threading the
+disk vanishes. We employ the finite difference code ZEUS to evolve the ideal
+MHD equations. Performing a set of numerical simulations in a fixed
+computational domain with increasing resolution, we demonstrate that turbulent
+activity decreases as resolution increases. We quantify the turbulent activity
+by measuring the rate of angular momentum transport through evaluating the
+standard alpha parameter. We find alpha=0.004 when (N_x,N_y,N_z)=(64,100,64),
+alpha=0.002 when (N_x,N_y,N_z)=(128,200,128) and alpha=0.001 when
+(N_x,N_y,N_z)=(256,400,256). This steady decline is an indication that
+numerical dissipation, occurring at the grid scale is an important determinant
+of the saturated form of the MHD turbulence. Analysing the results in Fourier
+space, we demonstrate that this is due to the MRI forcing significant flow
+energy all the way down to the grid dissipation scale. We also use our results
+to study the properties of the numerical dissipation in ZEUS. Its amplitude is
+characterised by the magnitude of an effective magnetic Reynolds number Re_M
+which increases from 10^4 to 10^5 as the number of grid points is increased
+from 64 to 256 per scale height. The simulations we have carried out do not
+produce results that are independent of the numerical dissipation scale, even
+at the highest resolution studied. Thus it is important to use physical
+dissipation, both viscous and resistive, and to quantify contributions from
+numerical effects, when performing numerical simulations of MHD turbulence with
+zero net flux in accretion disks at the resolutions normally considered.",0705.3621v2
+2007-11-20,Highly Frustrated Magnetic Clusters: The kagome on a sphere,"We present a detailed study of the low-energy excitations of two existing
+finite-size realizations of the planar kagome Heisenberg antiferromagnet on the
+sphere, the cuboctahedron and the icosidodecahedron. After highlighting a
+number of special spectral features (such as the presence of low-lying singlets
+below the first triplet and the existence of localized magnons) we focus on two
+major issues. The first concerns the nature of the excitations above the
+plateau phase at 1/3 of the saturation magnetization Ms. Our exact
+diagonalizations for the s=1/2 icosidodecahedron reveal that the low-lying
+plateau states are adiabatically connected to the degenerate collinear
+``up-up-down'' ground states of the Ising point, at the same time being well
+isolated from higher excitations. A complementary physical picture emerges from
+the derivation of an effective quantum dimer model which reveals the central
+role of the topology and the intrinsic spin s. We also give a prediction for
+the low energy excitations and thermodynamic properties of the spin s=5/2
+icosidodecahedron Mo72Fe30. In the second part we focus on the low-energy
+spectra of the s>1/2 Heisenberg model in view of interpreting the broad
+inelastic neutron scattering response reported for Mo72Fe30. To this end we
+demonstrate the simultaneous presence of several broadened low-energy ``towers
+of states'' or ``rotational bands'' which arise from the large discrete spatial
+degeneracy of the classical ground states, a generic feature of highly
+frustrated clusters. This semiclassical interpretation is further corroborated
+by their striking symmetry pattern which is shown, by an independent group
+theoretical analysis, to be a characteristic fingerprint of the classical
+coplanar ground states.",0711.3231v2
+2008-05-26,A Swift gaze into the 2006 March 29th burst forest of SGR 1900+14,"We report on the intense burst ``forest'' recorded on 2006 March 29 which
+lasted for ~30s. More than 40 bursts were detected both by BAT and by XRT,
+seven of which are rare intermediate flares (IFs): several times 10^{42} ergs
+were released. The BAT data were used to carry out time-resolved spectroscopy
+in the 14-100keV range down to 8ms timescales.
+  This unique dataset allowed us to test the magnetar model predictions such as
+the magnetically trapped fireball and the twisted magnetosphere over an
+unprecedented range of fluxes and with large statistics (in terms of both
+photons and IFs). We confirmed that a two blackbody component fits adequately
+the time-resolved and integrated spectra of IFs. However, Comptonization models
+give comparable good reduced chi^2. Moreover, we found: i) a change of
+behavior, around ~10^{41} erg/s, above which the softer blackbody shows a sort
+of saturation while the harder one still grows to a few times 10^{41} erg/s;
+ii) a rather sharp correlation between temperature and radii of the blackbodies
+(R^2 prop kT^{-3}), which holds for the most luminous parts of the flares
+(approximately for L_{tot} > 10^{41} erg/s). Within the magnetar model, the
+majority of these findings can be accounted for in terms of thermalised
+emission from the E-mode and O-mode photospheres. Interestingly, the maximum
+observed luminosity coming from a region of ~15km matches the magnetic
+Eddington luminosity at the same radius, for a surface dipole field of ~8 x
+10^{14} G (virtually equal to the one deduced from the spindown of SGR
+1900+14).",0805.3919v1
+2008-11-28,"Transport, magnetic, and structural properties of La$_{0.7}$Ce$_{0.3}$MnO$_3$ thin films. Evidence for hole-doping","Cerium-doped manganite thin films were grown epitaxially by pulsed laser
+deposition at $720 ^\circ$C and oxygen pressure $p_{O_2}=1-25 $Pa and were
+subjected to different annealing steps. According to x-ray diffraction (XRD)
+data, the formation of CeO$_2$ as a secondary phase could be avoided for
+$p_{O_2}\ge 8 $Pa. However, transmission electron microscopy shows the presence
+of CeO$_2$ nanoclusters, even in those films which appear to be single phase in
+XRD. With O$_2$ annealing, the metal-to-insulator transition temperature
+increases, while the saturation magnetization decreases and stays well below
+the theoretical value for electron-doped La$_{0.7}$Ce$_{0.3}$MnO$_3$ with mixed
+Mn$^{3+}$/Mn$^{2+}$ valences. The same trend is observed with decreasing film
+thickness from 100 to 20 nm, indicating a higher oxygen content for thinner
+films. Hall measurements on a film which shows a metal-to-insulator transition
+clearly reveal holes as dominating charge carriers. Combining data from x-ray
+photoemission spectroscopy, for determination of the oxygen content, and x-ray
+absorption spectroscopy (XAS), for determination of the hole concentration and
+cation valences, we find that with increasing oxygen content the hole
+concentration increases and Mn valences are shifted from 2+ to 4+. The
+dominating Mn valences in the films are Mn$^{3+}$ and Mn$^{4+}$, and only a
+small amount of Mn$^{2+}$ ions can be observed by XAS. Mn$^{2+}$ and Ce$^{4+}$
+XAS signals obtained in surface-sensitive total electron yield mode are
+strongly reduced in the bulk-sensitive fluorescence mode, which indicates
+hole-doping in the bulk for those films which do show a metal-to-insulator
+transition.",0811.4710v1
+2010-04-08,"MRI-driven turbulent transport: the role of dissipation, channel modes and their parasites","In the recent years, MRI-driven turbulent transport has been found to depend
+in a significant way on fluid viscosity $\nu$ and resistivity $\eta$ through
+the magnetic Prandtl number $Pm=\nu/\eta$. In particular, the transport
+decreases with decreasing $Pm$; if persistent at very large Reynolds numbers,
+this trend may lead to question the role of MRI-turbulence in YSO disks, whose
+Prandtl number is usually very small. In this context, the principle objective
+of the present investigation is to characterize in a refined way the role of
+dissipation. Another objective is to characterize the effect of linear (channel
+modes) and quasi-linear (parasitic modes) physics in the behavior of the
+transport. These objectives are addressed with the help of a number of
+incompressible numerical simulations. The horizontal extent of the box size has
+been increased in order to capture all relevant (fastest growing) linear and
+secondary parasitic unstable modes. The major results are the following: i- The
+increased accuracy in the computation of transport averages shows that the
+dependence of transport on physical dissipation exhibits two different regimes:
+for $Pm \lesssim 1$, the transport has a power-law dependence on the magnetic
+Reynolds number rather than on the Prandtl number; for $Pm > 1$, the data are
+consistent with a primary dependence on $Pm$ for large enough ($\sim 10^3$)
+Reynolds numbers. ii- The transport-dissipation correlation is not clearly or
+simply related to variations of the linear modes growth rates. iii- The
+existence of the transport-dissipation correlation depends neither on the
+number of linear modes captured in the simulations, nor on the effect of the
+parasitic modes on the saturation of the linear modes growth. iv- The transport
+is usually not dominated by axisymmetric (channel) modes",1004.1384v1
+2010-04-26,Chromospheric activity among fast rotating M-dwarfs in the open cluster NGC 2516,"We report radial velocities (RVs), projected equatorial velocities (v sin i)
+and CaII triplet (CaT) chromospheric activity indices for 237 late-K to mid-M
+candidate members of the young open cluster NGC 2516. These stars have rotation
+periods between 0.1 and 15 days. Intermediate resolution spectra were obtained
+using the Giraffe spectrograph at the Very Large Telescope. Membership was
+confirmed on the basis of RVs for 210 targets. We see a marked increase in the
+fraction of rapidly rotators as we move to cooler spectral types. About 20 per
+cent of M0-M1 stars have v sin i >15km/s, increasing to 90 per cent of M4
+stars. Activity indices derived from the first two lines of the CaT (8498A and
+8542A) show differing dependencies on rotation period and mass for stars lying
+above and below the fully convective boundary. Higher mass stars, of spectral
+type K3-M2.5, show chromospheric activity which increases with decreasing
+Rossby number (the ratio of period to convective turnover time), saturating for
+Rossby numbers <0.1. For cooler stars, which are probably fully convective and
+almost all of which have Rossby numbers <0.1, there is a clear decrease in
+chromospheric activity as (V-I)_0 increases, amounting to a fall of about a
+factor of 2-3 between spectral types M2.5 and M4. This decrease in activity
+levels at low Rossby numbers is not seen in X-ray observations of the coronae
+of cluster M-dwarfs or of active field M-dwarfs. There is no evidence for
+supersaturation of chromospheric activity for stars of any spectral type at
+Rossby numbers <0.01. We suggest that the fall in the limiting level of
+chromospheric emission beyond spectral type M3 in NGC~2516 is, like the
+simultaneous increase in rotation rates in field stars, associated with a
+change in the global magnetic topology as stars approach the fully convective
+boundary and not due to any decrease in dynamo-generated magnetic flux.",1004.4557v1
+2010-10-04,Way to increase the user access at the LCLS baseline,"The LCLS beam is meant for a single user, but the baseline undulator is long
+enough to serve two users simultaneously. To this end, we propose a setup
+composed of two elements: an X-ray mirrors pair for X-ray beam deflection, and
+a 4 m-long magnetic chicane, which creates an offset for mirrors pair
+installation in the middle of the baseline undulator. The insertable mirrors
+pair can separate spatially the X-ray beams generated in the first and in the
+second half of the baseline undulator. Rapid switching of the FEL amplification
+process allows deactivating one half and activating another half of the
+undulator. As proposed elsewhere, using a kicker installed upstream of the LCLS
+baseline undulator and an already existing corrector in the first half of the
+undulator, it is possible to rapidly switch the X-ray beam from one user to
+another. We present simulation results for the LCLS baseline, and show that it
+is possible to generate two saturated SASE X-ray beams in the whole 0.8-8 keV
+photon energy range in the same baseline undulator. These can serve two users.
+Our technique does not perturb the baseline mode of operation of the LCLS
+undulator. Also, the magnetic chicane setup is very flexible, and can be used
+as a self-seeding setup too. We present simulation results for the LCLS
+baseline undulator with SHAB. One can produce monochromatic radiation at the
+2nd harmonic as well as at the 1st. We describe an efficient way for obtaining
+multi-user operation at the LCLS hard X-ray FEL. To this end, a photon beam
+distribution system based on the use of crystals in the Bragg reflection
+geometry is proposed. The reflectivity of crystal deflectors can be switched
+fast enough by flipping the crystals with piezoelectric devices. Monochromatic
+hard X-rays can then be distributed among 6 independent experiments, thereby
+enabling 6 users to work in parallel in the near and far experimental halls.",1010.0489v1
+2011-05-12,Thermal Instability in Gravitationally-Stratified Plasmas: Implications for Multi-Phase Structure in Clusters and Galaxy Halos,"We study the interplay among cooling, heating, conduction, and magnetic
+fields in gravitationally stratified plasmas using simplified, plane-parallel
+numerical simulations. Since the physical heating mechanism remains uncertain
+in massive halos such as groups or clusters, we adopt a simple,
+observationally-motivated prescription which enforces global thermal
+equilibrium when averaged over large scales. The plasma remains susceptible to
+local thermal instability, however, and cooling drives an inward flow of
+material. In contrast to previous results, we argue that the thermal stability
+of the plasma is independent of its convective stability. We find that the
+ratio of the cooling timescale to the dynamical timescale t_cool/t_ff controls
+the saturation of the thermal instability: when t_cool/t_ff < 1, the plasma
+develops extended multi-phase structure, whereas when t_cool / t_ff > 1 it does
+not. (In a companion paper, we show that the criterion for thermal instability
+in a spherical potential is somewhat less stringent, t_cool / t_ff < 10.) When
+thermal conduction is anisotropic with respect to the magnetic field, the
+criterion for multi-phase structure is essentially independent of the thermal
+conductivity of the plasma. Our criterion for local thermal instability to
+produce multi-phase structure is an extension of the cold vs. hot accretion
+modes in galaxy formation that applies at all radii in hot halos, not just to
+the virial shock. We show that this criterion is consistent with data on
+multi-phase gas in the ACCEPT sample of clusters; in addition, when t_cool /
+t_ff > 1, the net cooling rate to low temperatures and the mass flux to small
+radii are suppressed enough relative to models without heating to be
+qualitatively consistent with star formation rates and x-ray line emission in
+groups and clusters.",1105.2563v2
+2013-04-04,On the origin of the radio emission of Sw 1644+57,"We apply relativistic equipartition synchrotron arguments to the radio data
+of the tidal disruption event candidate Sw 1644+57. We find that, regardless of
+the details of the equipartition scenario considered, the energy required to
+produce the observed radio (i.e., energy in magnetic field and radio emitting
+electrons) must increase by a factor of ~20 during the first 200 days. It then
+saturates. This energy increase cannot be alleviated by a varying geometry of
+the system. The radio data can be explained by: (i) An afterglow like emission
+of the X-ray emitting narrow relativistic jet. The additional energy can arise
+here from a slower moving material ejected in the first few days that gradually
+catches up with the slowing down blast wave (Berger et al. 2012). However, this
+requires at least ~4x10^{53} erg in the slower moving outflow. This is much
+more than the energy of the fast moving outflow that produced the early X-rays
+and it severely constrains the overall energy budget. (ii) Alternatively, the
+radio may arise from a mildly relativistic quasi-spherical outflow. Here, the
+energy for the radio emission increases with time to at least ~10^{51} erg
+after 200 days. This scenario requires, however, a second X-ray emitting
+collimated relativistic component. Given these results, it is worthwhile to
+consider models in which the energy of the magnetic field and/or of the radio
+emitting electrons increases with time without a continuous energy supply to
+the blast wave. This can happen, for example, if the energy is injected
+initially mostly in one form (Poynting flux or baryonic) and it is gradually
+converted to the other form, leading to a deviation from equipartition. Another
+intriguing possibility is that a gradually decreasing Inverse Compton cooling
+modifies the synchrotron emission and leads to an increase of the available
+energy in the radio emitting electrons (Kumar et al. 2013).",1304.1542v2
+2013-05-08,Surface tension of the core-crust interface of neutron stars with global charge neutrality,"It has been shown recently that taking into account strong, weak,
+electromagnetic, and gravitational interactions, and fulfilling the global
+charge neutrality of the system, a transition layer will happen between the
+core and crust of neutron stars, at the nuclear saturation density. We use
+relativistic mean field theory together with the Thomas-Fermi approximation to
+study the detailed structure of this transition layer and calculate its surface
+and Coulomb energy. We find that the surface tension is proportional to a
+power-law function of the baryon number density in the core bulk region. We
+also analyze the influence of the electron component and the gravitational
+field on the structure of the transition layer and the value of the surface
+tension to compare and contrast with known phenomenological results in nuclear
+physics. Based on the above results we study the instability against
+Bohr-Wheeler surface deformations in the case of neutron stars obeying global
+charge neutrality. Assuming the core-crust transition at nuclear density
+$\rho_{core}\approx 2.7 * 10^{14}$ g cm$^{-3}$, we find that the instability
+sets the upper limit to the crust density, $\rho_{crust}^{crit}\approx 1.2 *
+10^{14}$ g cm$^{-3}$. This result implies a nonzero lower limit to the maximum
+electric field of the core-crust transition surface and makes inaccessible a
+limit of quasilocal charge neutrality in the limit $\rho_{crust}=\rho_{core}$.
+The general framework presented here can be also applied to study the stability
+of sharp phase transitions in hybrid stars as well as in strange stars, both
+bare and with outer crust. The results of this work open the way to a more
+general analysis of the stability of these transition surfaces, accounting for
+other effects such as gravitational binding, centrifugal repulsion, magnetic
+field induced by rotating electric field, and therefore magnetic dipole-dipole
+interactions.",1305.1974v2
+2013-08-16,Area inequalities for stable marginally outer trapped surfaces in Einstein-Maxwell-dilaton theory,"We prove area inequalities for stable marginally outer trapped surfaces in
+Einstein-Maxwell-dilaton theory. Our inspiration comes on the one hand from a
+corresponding upper bound for the area in terms of the charges obtained
+recently by Dain, Jaramillo and Reiris [1] in the pure Einstein-Maxwell case
+without symmetries, and on the other hand from Yazadjiev's inequality [2] in
+the axially symmetric Einstein-Maxwell-dilaton case. The common issue in these
+proofs and in the present one is a functional ${\mathscr W}$ of the matter
+fields for which the stability condition readily yields an {\it upper} bound.
+On the other hand, the step which crucially depends on whether or not a dilaton
+field is present is to obtain a {\it lower} bound for ${\mathscr W}$ as well.
+We obtain the latter by first setting up a variational principle for ${\mathscr
+W}$ with respect to the dilaton field $\phi$, then by proving existence of a
+minimizer $\psi$ as solution of the corresponding Euler-Lagrange equations and
+finally by estimating ${\mathscr W}(\psi)$. In the special case that the normal
+components of the electric and magnetic fields are proportional we obtain the
+area bound $A \ge 8\pi P Q$ in terms of the electric and magnetic charges. In
+the generic case our results are less explicit but imply rigorous
+`perturbation' results for the above inequality. All our inequalities are
+saturated for a 2-parameter family of static, extreme solutions found by
+Gibbons [3]. Via the Bekenstein-Hawking relation $A = 4S$ our results give
+positive lower bounds for the entropy $S$ which are particularly interesting in
+the Einstein-Maxwell-dilaton case.",1308.3659v3
+2014-02-01,Gate-tunable Kondo resistivity and dephasing rate in graphene studied by numerical renormalization group calculations,"We investigate the resistivity and dephasing rate in the Kondo regime due to
+magnetic impurities in graphene with different chemial potentials ($\mu$). The
+Kondo effect due to either carbon vacancies or magnetic adatoms in graphene is
+described by the single-orbital pseudo-gap asymmetric Anderson impurity model.
+We find that although the Anderson impurity model considered here is a mixed
+valence system, it can be drived into either the Kondo [$\mu > \mu_c$ (critical
+value) $>0$] or mixed valency ($\mu \approx \mu_c$) or empty orbital ($\mu <
+\mu_c$) regime by a gate voltage, giving rise to characteristic features in
+resistivity and dephasing rate in each regime. Specifically, in the case of
+$\mu < \mu_c$, the shapes of the resistivity (dephasing rate) curves for
+different $\mu$ are nearly identical. However, as temperature decreases, they
+start to increase to their maxima at a lower $T/T_K$ but more rapidly [as
+$(T_K/T)^{3/2}$] than in normal metals [here $T$ ($T_K$) denotes the (Kondo)
+temperature]. As $T$ further decreases, after reaching the maximum, the
+dephasing rate drops more quickly than in normal metals, behaving as
+$(T/T_K)^3$ instead of $(T/T_K)^2$. Furthermore, the resistivity has a distinct
+peak above the saturation value near $T_K$. In the case of $\mu > \mu_c$, in
+contrast, the resistivity curve has an additional broad shoulder above 10$T_K$
+and the dephasing rate exhibits an interesting shoulder-peak shape. In the
+narrow boundary region ($\mu \approx \mu_c$), both the resistivity and
+dephasing rate curves are similar to the corresponding ones in normal metals.
+This explains the conventional Kondo like resistivity from recent experiments
+on graphene with defects. The resistivity and dephasing rate are analysized in
+terms of the calculated $T$-dependent spectral function, correlation
+self-energy and renormalized impurity level.",1402.0040v1
+2015-08-10,A nonextensive view of the stellar braking indices,"The present work is based on a description for the angular mometum loss rate
+due to magnetic braking for main-sequence stars on the relationship between
+stellar rotation and age. In general, this loss rate denoted by $\mathrm
+dJ/\mathrm dt$ depends on angular velocity $\Omega$ in the form $\mathrm
+dJ/\mathrm dt\propto\Omega^{q}$, where $q$ is a parameter extracted from
+nonextensive statistical mechanics. Already, in context of stellar rotation,
+this parameter is greater than unity and it is directly related to the braking
+index. For $q$ equal to unity, the scenario of saturation of the magnetic field
+is recovered, otherwise $q$ indicates an unsaturated field. This new approach
+have been proposed and investigated by de Freitas \& De Medeiros for
+unsaturated field stars. In present work, we propose a nonextensive approach
+for the stellar rotational evolution based on the Reiners \& Mohanthy model. In
+this sense, we developed a nonextensive version of Reiners \& Mohanthy torque
+and also compare this generalized version with the model proposed in de Freitas
+\& De Medeiros based on the spin-down Kawaler torque for the main-sequence
+stars with F and G spectral types. We use the same sample of $\sim16 000$ field
+stars with rotational velocity $v \sin i$ limited in age and mass. As a result,
+we show that the Kawaler and Reiners \& Mohanthy models exhibit strong
+discrepancies, mainly in relation to the domain of validity of the entropic
+index $q$. These discrepancies are mainly due to sensitivity on the stellar
+radius. Finally, our results showed that modified Kawaler prescription is
+compatible with a wider mass range, while the Reiners \& Mohanty model is
+restricted to masses less than G6 stars.",1508.02237v1
+2015-11-13,Evolution of Accretion Discs around a Kerr Black Hole using Extended Magnetohydrodynamics,"Black holes accreting well below the Eddington rate are believed to have
+geometrically thick, optically thin, rotationally supported accretion discs in
+which the Coulomb mean free path is large compared to $GM/c^2$. In such an
+environment, the disc evolution may differ significantly from ideal
+magnetohydrodynamic predictions. We present non-ideal global axisymmetric
+simulations of geometrically thick discs around a rotating black hole. The
+simulations are carried out using a new code ${\rm\it grim}$, which evolves a
+covariant extended magnetohydrodynamics model derived by treating non-ideal
+effects as a perturbation of ideal magnetohydrodynamics. Non-ideal effects are
+modeled through heat conduction along magnetic field lines, and a difference
+between the pressure parallel and perpendicular to the field lines. The model
+relies on an effective collisionality in the disc from wave-particle scattering
+and velocity-space (mirror and firehose) instabilities. We find that the
+pressure anisotropy grows to match the magnetic pressure, at which point it
+saturates due to the mirror instability. The pressure anisotropy produces
+outward angular momentum transport with a magnitude comparable to that of MHD
+turbulence in the disc, and a significant increase in the temperature in the
+wall of the jet. We also find that, at least in our axisymmetric simulations,
+conduction has a small effect on the disc evolution because (1) the heat flux
+is constrained to be parallel to the field and the field is close to
+perpendicular to temperature gradients, and (2) the heat flux is choked by an
+increase in effective collisionality associated with the mirror instability.",1511.04445v1
+2016-01-09,Field-induced resistivity plateau and unsaturated negative magnetoresistance in topological semimetal TaSb2,"Several prominent transport properties have been identified as key signatures
+of topologicalmaterials. One is the resistivity plateau at low temperatures as
+observed in several topological insulators (TIs), another is the negative
+magnetoresistance (MR) when the applied magnetic field is parallel to the
+current direction as observed in several topological semimetals (TSMs)
+including Dirac semimetals (DSMs) and Weyl semimetals (WSMs). Usually, these
+two exotic phenomena emerge in distinct materials with or without time reversal
+symmetry (TRS), respectively. Here we report the discovery of a new member in
+TSMs, TaSb2, which clearly exhibits both of these phenomena in a single
+material. This compound crystallizes in a base-centered monoclinic,
+centrosymmetric structure, and is metallic with a low carrier density in the
+zero field. While applying magnetic field it exhibits insulating behavior
+before appearance of a resistivity plateau below Tc =13 K. In the plateau
+regime, the ultrahigh carrier mobility and extreme magnetoresistance (XMR) for
+the field perpendicular to the current are observed as in DSMs and WSMs, in
+addition to a quantum oscillation behavior with non-trivial Berry phases. In
+contrast to the most known DSMs and WSMs, the negative MR in TaSb2 does not
+saturate up to 9 T, which, together with the almost linear Hall resistivity,
+manifests itself an electron-hole non-compensated TMS. These findings indicate
+that the resistivity plateau could be a generic feature of topology-protected
+metallic states even in the absence of TRS and compatible with the negative MR
+depending on the field direction. Our experiment extends a materials basis
+represented by TaSb2 as a new platform for future theoretical investigations
+and device applications of topological materials.",1601.02062v1
+2016-05-29,Bulk Fermi-surface of the Weyl type-II semi-metallic candidate MoTe2,"The electronic structure of WTe$_2$ and orthorhombic $\gamma-$MoTe$_2$, are
+claimed to contain pairs of Weyl type-II points. A series of ARPES experiments
+claim a broad agreement with these predictions. We synthesized single-crystals
+of MoTe$_2$ through a Te flux method to validate these predictions through
+measurements of its bulk Fermi surface (FS) \emph{via} quantum oscillatory
+phenomena. We find that the superconducting transition temperature of
+$\gamma-$MoTe$_2$ depends on disorder as quantified by the ratio between the
+room- and low-temperature resistivities, suggesting the possibility of an
+unconventional superconducting pairing symmetry. Similarly to WTe$_2$, the
+magnetoresistivity of $\gamma-$MoTe$_2$ does not saturate at high magnetic
+fields and can easily surpass $10^{6}$ \%. Remarkably, the analysis of the de
+Haas-van Alphen (dHvA) signal superimposed onto the magnetic torque, indicates
+that the geometry of its FS is markedly distinct from the calculated one. The
+dHvA signal also reveals that the FS is affected by the Zeeman-effect
+precluding the extraction of the Berry-phase. A direct comparison between the
+previous ARPES studies and density-functional-theory (DFT) calculations reveals
+a disagreement in the position of the valence bands relative to the Fermi level
+$\varepsilon_F$. Here, we show that a shift of the DFT valence bands relative
+to $\varepsilon_F$, in order to match the ARPES observations, and of the DFT
+electron bands to explain some of the observed dHvA frequencies, leads to a
+good agreement between the calculations and the angular dependence of the FS
+cross-sectional areas observed experimentally. However, this relative
+displacement between electron- and hole-bands eliminates their crossings and,
+therefore, the Weyl type-II points predicted for $\gamma-$MoTe$_2$.",1605.09065v5
+2016-11-10,The H$α$ emission of nearby M dwarfs and its relation to stellar rotation,"The high-energy emission from low-mass stars is mediated by the magnetic
+dynamo. Although the mechanisms by which fully convective stars generate
+large-scale magnetic fields are not well understood, it is clear that, as for
+solar-type stars, stellar rotation plays a pivotal role. We present 270 new
+optical spectra of low-mass stars in the Solar Neighborhood. Combining our
+observations with those from the literature, our sample comprises 2202
+measurements or non-detections of H$\alpha$ emission in nearby M dwarfs. This
+includes 466 with photometric rotation periods. Stars with masses between 0.1
+and 0.6 solar masses are well-represented in our sample, with fast and slow
+rotators of all masses. We observe a threshold in the mass-period plane that
+separates active and inactive M dwarfs. The threshold coincides with the
+fast-period edge of the slowly rotating population, at approximately the
+rotation period at which an era of rapid rotational evolution appears to cease.
+The well- defined active/inactive boundary indicates that H$\alpha$ activity is
+a useful diagnostic for stellar rotation period, e.g. for target selection for
+exoplanet surveys, and we present a mass-period relation for inactive M dwarfs.
+We also find a significant, moderate correlation between
+$L_{\mathrm{H}\alpha}/L_{\mathrm{bol}}$ and variability amplitude: more active
+stars display higher levels of photometric variability. Consistent with
+previous work, our data show that rapid rotators maintain a saturated value of
+$L_{\mathrm{H}\alpha}/L_{\mathrm{bol}}$. Our data also show a clear power-law
+decay in $L_{\mathrm{H}\alpha}/L_{\mathrm{bol}}$ with Rossby number for slow
+rotators, with an index of $-1.7 \pm 0.1$.",1611.03509v1
+2017-02-10,Structure and variability in the corona of the ultrafast rotator LO Peg,"Low-mass ultrafast rotators show the typical signatures of magnetic activity
+and are known to produce flares, probably as a result of magnetic reconnection.
+As a consequence, the coronae of these stars exhibit very large X-ray
+luminosities and high plasma temperatures, as well as a pronounced inverse FIP
+effect. To probe the relationship between the coronal properties with a
+spectral type of ultra-fast rotators with rotation period P < 1d, we analyse
+the K3 rapid-rotator LO Peg observed with XMM-Newton and compare it with other
+low-mass rapid rotators of spectral types G9-M1. We investigate the temporal
+evolution of coronal properties like the temperatures, emission measures,
+abundances, densities and the morphology of the involved coronal structures. We
+find two distinguishable levels of activity in the XMM-Newton observation of
+LO~Peg, which shows significant X-ray variability both in phase and amplitude,
+implying the presence of an evolving active region on the surface. The X-ray
+flux varies by 28%, possibly due to rotational modulation. During our
+observation, a large X-ray flare with a peak X-ray luminosity of 2E30 erg/s and
+an energy of 7.3E33 erg was observed. At the flare onset we obtain clear
+signatures for the occurrence of the Neupert effect. The flare plasma also
+shows an enhancement of iron by a factor of 2 during the rise and peak phase of
+the flare. Our modeling analysis suggests that the scale size of the flaring
+X-ray plasma is smaller than 0.5 R_star. Further, the flare loop length appears
+to be smaller than the pressure scale height of the flaring plasma. Our studies
+show that the X-ray properties of the LO~Peg are very similar to those of other
+low-mass ultrafast rotators, i.e., the X-ray luminosity is very close to
+saturation, its coronal abundances follow a trend of increasing abundance with
+increasing first ionisation potential, the so-called inverse FIP effect.",1702.03158v1
+2017-02-20,Quantum critical phase with infinite projected entangled paired states,"A classification of SU(2)-invariant Projected Entangled Paired States (PEPS)
+on the square lattice, based on a unique site tensor, has been recently
+introduced by Mambrini et al.~\cite{Mambrini2016}. It is not clear whether such
+SU(2)-invariant PEPS can either i) exhibit long-range magnetic order (like in
+the N\'eel phase) or ii) describe a genuine quantum critical point (QCP) or
+quantum critical phase (QCPh) separating two ordered phases. Here, we identify
+a specific family of SU(2)-invariant PEPS of the classification which provides
+excellent variational energies for the $J_1-J_2$ frustrated Heisenberg model,
+especially at $J_2=0.5$, corresponding to the approximate location of the QCP
+or QCPh separating the N\'eel phase from a dimerized phase. The PEPS are build
+from virtual states belonging to the $\frac{1}{2}^{\otimes N} \oplus 0$
+SU(2)-representation, i.e. with $N$ ""colors"" of virtual
+\hbox{spin-$\frac{1}{2}$}. Using a full update infinite-PEPS approach directly
+in the thermodynamic limit, based on the Corner Transfer Matrix renormalization
+algorithm supplemented by a Conjugate Gradient optimization scheme, we provide
+evidence of i) the absence of magnetic order and of ii) diverging correlation
+lengths (i.e. showing no sign of saturation with increasing environment
+dimension) in both the singlet and triplet channels, when the number of colors
+$N\ge 3$. We argue that such a PEPS gives a qualitative description of the QCP
+or QCPh of the $J_1-J_2$ model.",1702.05950v5
+2017-09-04,Full angular dependence of the spin Hall and ordinary magnetoresistance in epitaxial antiferromagnetic NiO(001)/Pt thin films,"We report the observation of the three-dimensional angular dependence of the
+spin Hall magnetoresistance (SMR) in a bilayer of the epitaxial
+antiferromagnetic insulator NiO(001) and the heavy metal Pt, without any
+ferromagnetic element. The detected angular-dependent longitudinal and
+transverse magnetoresistances are measured by rotating the sample in magnetic
+fields up to 11 T, along three orthogonal planes (xy-, yz- and xz-rotation
+planes, where the z-axis is orthogonal to the sample plane). The total
+magnetoresistance has contributions arising from both the SMR and ordinary
+magnetoresistance. The onset of the SMR signal occurs between 1 and 3 T and no
+saturation is visible up to 11 T. The three-dimensional angular dependence of
+the SMR can be explained by a model considering the reversible field-induced
+redistribution of magnetostrictive antiferromagnetic S- and T-domains in the
+NiO(001), stemming from the competition between the Zeeman energy and the
+elastic clamping effect of the non-magnetic MgO substrate. From the observed
+SMR ratio, we estimate the spin mixing conductance at the NiO/Pt interface to
+be greater than $2\times10^{14}$ ${\Omega}^{-1}$ $m^{-2}$. Our results
+demonstrate the possibility to electrically detect the N\'eel vector direction
+in stable NiO(001) thin films, for rotations in the xy- and xz- planes.
+Moreover, we show that a careful subtraction of the ordinary magnetoresistance
+contribution is crucial to correctly estimate the amplitude of the SMR.",1709.00910v5
+2017-12-10,The role of fast ions in stabilising the ion temperature gradient mode,"Turbulence driven by small scale instabilities causes large heat and particle
+transport and is a major limiting factor of current fusion devices. Above a
+critical value, the ion temperature gradient leads to the growth of a
+microinstability -- the ion temperature gradient mode -- that often dominates
+the ion energy transport. It has recently been discovered that energetic ions
+generated by auxiliary heating may reduce the growth of this instability. By
+applying the gyrokinetic formalism and performing linear simulations using the
+local continuum gyrokinetic code GS2, we explore the linear physics of this
+stabilising effect. In order to isolate important effects due to the presence
+of fast ions, we make use of the flexibility of GS2 to change the plasma and
+magnetic geometry parameters independently. We assess the possibility to
+neglect magnetic geometry changes to simplify the analysis, by investigating
+its contribution to the stabilising effect. For the cases studied we find that
+the Shafranov shift and safety factor profile might have to be taken into
+account. For fixed fast ion density and temperature a destabilising influence
+of their density gradient is found, while the high fast ion temperature
+gradient is stabilising, both as predicted by theoretical models. A large part
+of the observed stabilisation comes from the fast ion contribution to the
+plasma $\beta$. In addition, the effect of $\beta$ is enhanced because of the
+large density and temperature gradients of the fast ions. We investigate the
+role of hot ion mass and charge in order to evaluate the stabilisation of
+different types of hot ions. Also the possibility of adjusting the electron and
+ion profiles to account for the presence of fast ions without including them as
+a kinetic species, is considered. Finally, quasi-linear theory is invoked for
+linking linear results to saturated values of the nonlinear heat fluxes.",1712.03587v1
+2018-11-14,"Anisotropic-Exchange Magnets on a Triangular Lattice: Spin Waves, Accidental Degeneracies, and Dual Spin Liquids","We present an extensive overview of the phase diagram, spin-wave excitations,
+and finite-temperature transitions of the anisotropic-exchange magnets on an
+ideal nearest-neighbor triangular lattice. We investigate transitions between
+five principal classical phases of the corresponding model: ferromagnetic,
+N\'{e}el, its dual, and the two stripe phases. Transitions are identified by
+the spin-wave instabilities and by the Luttinger-Tisza approach. Some of the
+transitions are direct and others occur via intermediate phases with more
+complicated forms of ordering. In a portion of the N\'{e}el phase, we find
+spin-wave instabilities to a long-range spiral-like state. In the stripe
+phases, quantum fluctuations are mostly negligible, leaving the ordered moment
+nearly saturated even for the $S=1/2$ case. However, for a two-dimensional
+surface of the full 3D parameter space, the spin-wave spectrum in one of the
+stripe phases exhibits an enigmatic accidental degeneracy manifested by
+pseudo-Goldstone modes. As a result, despite the nearly classical ground state,
+the ordering transition temperature in a wide region of the phase diagram is
+significantly suppressed from the mean-field expectation. We identify this
+accidental degeneracy as due to an exact correspondence to an extended
+Kitaev-Heisenberg model with emergent symmetries that naturally lead to the
+pseudo-Goldstone modes. There are previously studied dualities within the
+Kitaev-Heisenberg model on the triangular lattice that are exposed here in a
+wider parameter space. One important implication of this correspondence for the
+$S=1/2$ case is the existence of a region of the spin-liquid phase that is dual
+to the spin-liquid phase discovered recently by us. We complement our studies
+by the density-matrix renormalization group of the $S=1/2$ model to confirm
+some of the duality relations and to verify the existence of the dual
+spin-liquid phase.",1811.05983v4
+2019-05-26,Imaging viscous flow of the Dirac fluid in graphene,"The electron-hole plasma in charge-neutral graphene is predicted to realize a
+quantum critical system whose transport features a universal hydrodynamic
+description, even at room temperature. This quantum critical ""Dirac fluid"" is
+expected to have a shear viscosity close to a minimum bound, with an
+inter-particle scattering rate saturating at the Planckian time $\hbar/(k_B
+T)$. While electrical transport measurements at finite carrier density are
+consistent with hydrodynamic electron flow in graphene, a ""smoking gun"" of
+viscous behavior remains elusive. In this work, we directly image viscous Dirac
+fluid flow in graphene at room temperature via measurement of the associated
+stray magnetic field. Nanoscale magnetic imaging is performed using quantum
+spin magnetometers realized with nitrogen vacancy (NV) centers in diamond.
+Scanning single-spin and wide-field magnetometry reveals a parabolic Poiseuille
+profile for electron flow in a graphene channel near the charge neutrality
+point, establishing the viscous transport of the Dirac fluid. This measurement
+is in contrast to the conventional uniform flow profile imaged in an Ohmic
+conductor. Via combined imaging-transport measurements, we obtain viscosity and
+scattering rates, and observe that these quantities are comparable to the
+universal values expected at quantum criticality. This finding establishes a
+nearly-ideal electron fluid in neutral graphene at room temperature. Our
+results pave the way to study hydrodynamic transport in quantum critical fluids
+relevant to strongly-correlated electrons in high-$T_c$ superconductors. This
+work also highlights the capability of quantum spin magnetometers to probe
+correlated-electronic phenomena at the nanoscale.",1905.10791v3
+2019-08-14,NuSTAR and XMM-Newton observations of SXP 59 during its 2017 giant outburst,"The Be X-ray pulsar (BeXRP) SXP 59 underwent a giant outburst in 2017 with a
+peak X-ray luminosity of $1.1\times10^{38}$ erg~s$^{-1}$. We report on the
+X-ray behaviour of SXP 59 with the XMM--Newton and NuSTAR observations
+collected at the outburst peak, decay, and the low luminosity states. The pulse
+profiles are energy dependent, the pulse fraction increases with the photon
+energy and saturates at $\sim$ 65% above 10 keV. It is difficult to constrain
+the change in the geometry of emitting region with the limited data.
+Nevertheless, because the pulse shape generally has a double-peaked profile at
+high luminosity and a single peak profile at low luminosity, we prefer the
+scenario that the source transited from the super-critical state to the
+sub-critical regime. This result would further imply that the neutron star (NS)
+in SXP 59 has a typical magnetic field. We confirm that the soft excess
+revealed below 2 keV is dominated by a cool thermal component. On the other
+hand, the NuSTAR spectra can be described as a combination of the non-thermal
+component from the accretion column, a hot blackbody emission, and an iron
+emission line. The temperature of the hot thermal component decreases with
+time, while its size remains constant ($R \sim 0.6$ km). The existence of the
+hot blackbody at high luminosity cannot be explained with the present accretion
+theories for BeXRPs. It means that either more sophisticated spectral models
+are required to describe the X-ray spectra of luminous BeXRPs, or there is
+non-dipole magnetic field close to the NS surface.",1908.04908v2
+2020-06-16,Topological Dirac states in a layered telluride TaPdTe$_5$ with quasi-one-dimensional PdTe$_2$ chains,"We report the synthesis and systematic studies of a new layered ternary
+telluride TaPdTe5 with quasi-one-dimensional PdTe2 chains. This compound
+crystalizes in a layered orthorhombic structure with space group Cmcm. Analysis
+of its curved field-dependent Hall resistivity, using the two-band model,
+indicates the hole-dominated transport with a high mobility ${\mu}_h$ = 2.38
+$\times$ 10$^3$ cm$^2$ V$^{-1}$ s$^{-1}$ at low temperatures. The in-plane
+magnetoresistance (MR) displays significant anisotropy with field applied along
+the crystallographic $b$ axis. The MR with the current applied along the
+$c$-axis is also measured in high magnetic fields up to 51.7 T. Remarkably, it
+follows a power-law dependence and reaches (9.5 $\times$ 10$^3$)% at 2.1 K
+without any signature of saturation. The De Haas-van Alphen oscillations show a
+small Fermi-surface pocket with a nontrivial Berry phase. The Shubnikov-de Haas
+(SdH) oscillations are detected at low temperatures and under magnetic fields
+above 28.5 T. Two effective masses $m^*$ (0.26$m_e$ and 0.41$m_e$) are
+extracted from the oscillatory SdH data. Our first-principles calculations
+unveil a topological Dirac cone in its surface states, and, in particular, the
+topological index indicates that TaPdTe$_5$ is a topologically nontrivial
+material.",2006.09070v2
+2020-08-24,Joint action of Hall and ambipolar effects in 3D magneto-convection simulations of the quiet Sun. I. Dissipation and generation of waves,"The partial ionization of the solar plasma causes several nonideal effects
+such as the ambipolar diffusion, the Hall effect, and the Biermann battery
+effect. Here we report on the first three-dimensional realistic simulations of
+solar local dynamo where all three effects were taken into account. The
+simulations started with a snapshot of already saturated battery-seeded dynamo,
+where two new series were developed: one with solely ambipolar diffusion and
+another one also taking into account the Hall term in the generalized Ohm's
+law. The simulations were then run for about 4 hours of solar time to reach the
+stationary regime and improve the statistics. In parallel, a purely MHD dynamo
+simulation was also run for the same amount of time. The simulations are
+compared in a statistical way. The results show that, with the inclusion of the
+ambipolar diffusion, the amplitudes of the incompressible perturbations related
+to Alfven waves are reduced, and the Poynting flux is absorbed, with a
+frequency dependence. The Hall effect causes the opposite action: significant
+excess of incompressible perturbations is generated and an excess of the
+Poynting flux is observed in the chromospheric layers. The model with ambipolar
+diffusion shows, on average, sharper current sheets and slightly more abundant
+fast magneto-acoustic shocks in the chromosphere. The model with the Hall
+effect has higher temperatures at the lower chromosphere and stronger and more
+vertical magnetic field concentrations all over the chromosphere. The study of
+high-frequency waves reveals that significant power of incompressible
+perturbations is associated with areas with intense and more vertical magnetic
+fields and larger temperatures. We find a positive correlation between the
+magnitude of the ambipolar heating and the temperature increase at the same
+location after a characteristic time of 10^2 sec.",2008.10429v1
+2020-09-10,Parallel Spin Stripes and Their Coexistance with Superconducting Ground States at Optimal and High Doping in La$_{1.6-x}$Nd$_{0.4}$Sr$_x$CuO$_4$,"Quasi-two dimensional quantum magnetism is clearly highly correlated with
+superconducting ground states in cuprate-based High T$_c$ superconductivity.
+Three dimensional, commensurate long range magnetic order in La$_2$CuO$_4$
+quickly evolves to quasi-two dimensional, incommensurate correlations on doping
+with mobile holes, and superconducting ground states follow for x as small as
+0.05 in the La$_{2-x}$Sr$_x$/Ba$_x$CuO$_4$ family of superconductors. It has
+long been known that the onset of superconducting ground states in these
+systems is coincident with a remarkable rotation of the incommensurate spin
+order from ""diagonal stripes"" below x = 0.05, to ""parallel stripes"" above.
+However, little is known about the spin correlations at optimal and high doping
+levels, where the dome of superconductivity draws to an end. Here we present
+new elastic and inelastic neutron scattering measurements on single crystals of
+La$_{1.6-x}$Nd$_{0.4}$Sr$_x$CuO$_4$ with x = 0.125, 0.19, 0.24 and 0.26, and
+show that two dimensional, quasi-static, parallel spin stripes are observed to
+onset at temperatures such that the parallel spin stripe phase envelopes all
+superconducting ground states in this system. Parallel spin stripes stretch
+across 0.05 < < 0.26, with rapidly decreasing moment size and onset
+temperatures for x > 0.125. We also show that the low energy, parallel spin
+stripe fluctuations for optimally doped x = 0.19 display dynamic spectral
+weight which grows with decreasing temperature and saturates below its
+superconducting T$_c$. The elastic order parameter for x = 0.19 also shows
+plateau behavior coincident with the onset of superconductivity. This set of
+observations assert the foundational role played by two dimensional parallel
+spin stripe order and fluctuations in High T$_c$ cuprate superconductivity.",2009.04627v1
+2020-10-21,A new cosmic ray-driven instability,"Cosmic ray (CR)-driven instabilities play a decisive role during particle
+acceleration at shocks and CR propagation in galaxies and galaxy clusters.
+These instabilities amplify magnetic fields and modulate CR transport so that
+the intrinsically collisionless CR population is tightly coupled to the thermal
+plasma and provides dynamical feedback. Here, we show that CRs with a finite
+pitch angle drive electromagnetic waves (along the background magnetic field)
+unstable on intermediate scales between the gyro-radii of CR ions and electrons
+as long as CRs are drifting with a velocity less than half of the Alfv\'en
+speed of electrons. By solving the linear dispersion relation, we show that
+this new instability typically grows faster by more than an order of magnitude
+in comparison to the commonly discussed resonant instability at the ion
+gyroscale. We find the growth rate for this intermediate-scale instability and
+identify the growing modes as background ion-cyclotron modes in the frame that
+is comoving with the CRs. We confirm the theoretical growth rate with a
+particle-in-cell (PIC) simulation and study the non-linear saturation of this
+instability. We identify three important astro-physical applications of this
+intermediate-scale instability, which is expected to 1. modulate CR transport
+and strengthen CR feedback in galaxies and galaxy clusters, 2. enable electron
+injection into the diffusive shock acceleration process, and 3. decelerate CR
+escape from the sites of particle acceleration which would generate gamma-ray
+halos surrounding CR sources such as supernova remnants.",2010.11197v2
+2020-11-20,Activity-rotation in the dM4 star Gl 729. A possible chromospheric cycle,"Recently, new debates about the role of layers of strong shear have emerged
+in stellar dynamo theory. Further information on the long-term magnetic
+activity of fully convective stars could help determine whether their
+underlying dynamo could sustain activity cycles similar to the solar one.
+  We performed a thorough study of the short- and long-term magnetic activity
+of the young active dM4 star Gl 729. First, we analyzed long-cadence $K2$
+photometry to characterize its transient events (e.g., flares) and global and
+surface differential rotation. Then, from the Mount Wilson $S$-indexes derived
+from CASLEO spectra and other public observations, we analyzed its long-term
+activity between 1998 and 2020 with four different time-domain techniques to
+detect cyclic patterns. Finally, we explored the chromospheric activity at
+different heights with simultaneous measurements of the H$\alpha$ and the Na I
+D indexes, and we analyzed their relations with the $S$-Index.
+  We found that the cumulative flare frequency follows a power-law distribution
+with slope $\sim- 0.73$ for the range $10^{32}$ to $10^{34}$ erg. We obtained
+$P_{rot} = (2.848 \pm 0.001)$ days, and we found no evidence of differential
+rotation. We also found that this young active star presents a long-term
+activity cycle with a length of $\text{about four}$ years; there is less
+significant evidence of a shorter cycle of $0.8$ year. The star also shows a
+broad activity minimum between 1998 and 2004. We found a correlation between
+the S index, on the one hand, and the H$\alpha$ the Na I D indexes, on the
+other hand, although the saturation level of these last two indexes is not
+observed in the Ca lines.
+  Because the maximum-entropy spot model does not reflect migration between
+active longitudes, this activity cycle cannot be explained by a solar-type
+dynamo. It is probably caused by an $\alpha^2$-dynamo.",2011.10391v1
+2020-12-28,"Structural, optical and magnetic properties of nanostructured Cr-substituted Ni-Zn spinel ferrites synthesized by a microwave combustion method","Nanoparticles of Cr3+-substituted Ni-Zn ferrites with a general formula
+Ni0.4Zn0.6-xCrxFe2O4 (x = 0.0 - 0.6) have been synthesized via a facile
+microwave combustion route. The crystalline phase has been characterized by
+XRD, TEM, FT-I and XPS revealing the spinel ferrite structure without extra
+phases. Crystallite sizes of 23 - 32 nm as estimated by XRD analyses, after
+corrections for crystal stains by Williamson-Hall method, are comparable to the
+average particle sizes observed by TEM which indicates successfully synthesized
+nanocrystals. Rietveld refinement analyses of the XRD patterns have inferred a
+monotonic decrease behavior of the lattice parameter with Cr doping in
+agreement with Vegard's law of solid solution series. Furthermore, cations
+distribution with an increased inversion factor indicate the B-site preference
+of Cr3+ ions. The oxidation states and cations distribution indicated by XPS
+results imply the Cr3+ doping on the account of Zn2+ ions and a partial
+reduction of Fe3+ to Fe2+ to keep the charge balance in a composition series of
+(Ni2+)0.4(Zn2+, Cr3+)0.6(Fe2+, Fe3+)2(O2-)4. The optical properties were
+explored by optical UV-Vis spectroscopy indicating allowed direct transitions
+with band gap energy that decreases from 3.9 eV to 3.7 eV with Cr doping.
+Furthermore, the photocatalytic activity for the degradation of methyl orange
+(MO) dye was investigated showing largely enhanced photodecomposition up to 30%
+of MO dye over Ni0.4Cr0.6Fe2O4 for 6 hours. A vibrating sample magnetometry
+(VSM) measurements at room temperature show further enhancement in the
+saturation magnetization of Ni0.4Zn0.6Fe2O4 , the highest in Ni-Zn ferrites,
+from about 60 to 70 emu/g with the increase of Cr concentration up to x = 0.1,
+while the coercivity shows a general increase in the whole range of Cr doping.",2012.14232v1
+2021-03-17,Distinguishing two-component anomalous Hall effect from topological Hall effect,"In transport, the topological Hall effect (THE) presents itself as
+non-monotonic features (or humps and dips) in the Hall signal and is widely
+interpreted as a sign of chiral spin textures, like magnetic skyrmions.
+However, when anomalous Hall effect (AHE) is also present, the co-existence of
+two AHEs could give rise to similar artifacts, making it difficult to
+distinguish between genuine THE with AHE and two-component AHE. Here we confirm
+genuine THE with AHE by means of transport and magneto-optical Kerr effect
+(MOKE) microscopy, in which magnetic skyrmions are directly observed, and find
+that genuine THE occurs in the transition region of the AHE. In sharp contrast,
+the artifact ""THE"", or two-component AHE occurs well beyond the saturation of
+the ""AHE component"" (under the false assumption of THE+AHE). Furthermore, we
+distinguish artifact ""THE"" from genuine THE by three methods: 1. Minor loops,
+2. Temperature dependence, 3. Gate dependence. Minor loops of genuine THE with
+AHE are always within the full loop, while minor loops of the artifact ""THE""
+may reveal a single loop that cannot fit into the ""AHE component"". Besides, the
+temperature or gate dependence of the artifact ""THE"" may also be accompanied by
+a polarity change of the ""AHE component"", as the non-monotonic features vanish,
+while the temperature dependence of genuine THE with AHE reveals no such
+change. Our work may help future researchers to exercise cautions and use these
+methods to examine carefully in order to ascertain genuine THE.",2103.09878v3
+2021-08-13,Criticality-Enhanced Quantum Sensing via Continuous Measurement,"Present protocols of criticality-enhanced sensing with open quantum sensors
+assume direct measurement of the sensor and omit the radiation quanta emitted
+to the environment, thereby potentially missing valuable information. Here we
+propose a protocol for criticality-enhanced sensing via continuous observation
+of the emitted radiation quanta. Under general assumptions, we establish a
+scaling theory for the global quantum Fisher information of the joint system
+and environment state at dissipative critical points. We derive universal
+scaling laws featuring transient and long-time behavior governed by the
+underlying critical exponents. Importantly, such scaling laws exceed the
+standard quantum limit and can in principle saturate the Heisenberg limit. To
+harness such advantageous scaling, we propose a practical sensing scheme based
+on continuous detection of the emitted quanta as realized experimentally in
+various quantum-optical setups. In such a scheme a single interrogation
+corresponds to a (stochastic) quantum trajectory of the open system evolving
+under the nonunitary dynamics dependent on the parameter to be sensed and the
+backaction of the continuous measurement. Remarkably, we demonstrate that the
+associated precision scaling significantly exceeds that based on direct
+measurement of the critical steady state, thereby establishing the metrological
+value of the continuous detection of the emitted quanta at dissipative
+criticality. We illustrate our protocol via counting the photons emitted by the
+open Rabi model, a paradigmatic model for the study of dissipative phase
+transition with finite components. Our protocol is applicable to generic
+quantum-optical open sensors permitting continuous readout, and may find
+applications at the frontier of quantum sensing, such as the human-machine
+interface, magnetic diagnosis of heart disease, and zero-field nuclear magnetic
+resonance.",2108.06349v2
+2021-12-01,Numerical Study of Cosmic Ray Confinement through Dust Resonant Drag Instabilities,"We investigate the possibility of cosmic ray (CR) confinement by charged dust
+grains through resonant drag instabilities (RDIs). We perform
+magnetohydrodynamic particle-in-cell simulations of magnetized gas mixed with
+charged dust and cosmic rays, with the gyro-radii of dust and GeV CRs on
+$\sim\mathrm{AU}$ scales fully resolved. As a first study, we focus on one type
+of RDI wherein charged grains drift super-Alfv{\'e}nically, with Lorentz forces
+strongly dominating over drag forces. Dust grains are unstable to the RDIs and
+form concentrated columns and sheets, whose scale grows until saturating at the
+simulation box size. Initially perfectly-streaming CRs are strongly scattered
+by RDI-excited Alfv{\'e}n waves, with the growth rate of the CR perpendicular
+velocity components equaling the growth rate of magnetic field perturbations.
+These rates are well-predicted by analytic linear theory. CRs finally become
+isotropized and drift at least at $\sim v_\mathrm{A}$ by unidirectional
+Alfv\'{e}n waves excited by the RDIs, with a uniform distribution of the pitch
+angle cosine $\mu$ and a flat profile of the CR pitch angle diffusion
+coefficient $D_{\mu\mu}$ around $\mu = 0$, without the ""$90$ degree pitch angle
+problem."" With CR feedback on the gas included, $D_{\mu\mu}$ decreases by a
+factor of a few, indicating a lower CR scattering rate, because the
+backreaction on the RDI from the CR pressure adds extra wave damping, leading
+to lower quasi-steady-state scattering rates. Our study demonstrates that the
+dust-induced CR confinement can be very important under certain conditions,
+e.g., the dusty circumgalactic medium around quasars or superluminous galaxies.",2112.00752v2
+2022-02-15,Thermodynamics of the spin-half square-kagome lattice antiferromagnet,"Over the last decade, the interest in the spin-$1/2$ Heisenberg
+antiferromagnet (HAF) on the square-kagome (also called shuriken) lattice has
+been growing as a model system of quantum magnetism with a quantum paramagnetic
+ground state, flat-band physics near the saturation field, and quantum scars.
+Here, we present large-scale numerical investigations of the specific heat
+$C(T)$, the entropy $S(T)$ as well as the susceptibility $\chi(T)$ by means of
+the finite-temperature Lanczos method for system sizes of
+$N=18,24,30,36,42,48$, and $N=54$. We find that the specific heat exhibits a
+low-temperature shoulder below the major maximum which can be attributed to
+low-lying singlet excitations filling the singlet-triplet gap, which is
+significantly larger than the singlet-singlet gap. This observation is further
+supported by the behavior of the entropy $S(T)$, where a change in the
+curvature is present just at about $T/J=0.2$, the same temperature where the
+shoulder in $C$ sets in. For the susceptibility the low-lying singlet
+excitations are irrelevant, and the singlet-triplet gap leads to an
+exponentially activated low-temperature behavior. The maximum in $\chi(T)$ is
+found at a pretty low temperature $T_{\rm max}/J=0.146$ (for $N=42$) compared
+to $T_{\rm max}/J=0.935$ for the unfrustrated square-lattice HAF signaling the
+crucial role of frustration also for the susceptibility. We find a striking
+similarity of our square-kagome data with the corresponding ones for the kagome
+HAF down to very low $T$. The magnetization process featuring plateaus and
+jumps and the field dependence of the specific heat that exhibits
+characteristic peculiarities attributed to the existence of a flat one-magnon
+band are as well discussed.",2202.07357v2
+2022-02-16,Giant oscillatory tunnel magnetoresistance in CoFe/MgO/CoFe(001) junctions,"The tunnel magnetoresistance (TMR) effect observed in magnetic tunnel
+junctions (MTJs) is commonly used in many spintronic applications because the
+effect can easily convert from local magnetic states to electric signals in a
+wide range of device resistances. In this study, we demonstrated TMR ratios of
+up to 631% at room temperature (RT), which is two or more times larger than
+those used currently for magnetoresistive random access memory (MRAM) devices,
+using CoFe/MgO/CoFe(001) epitaxial MTJs. The TMR ratio increased up to 1143% at
+10 K, which corresponds to an effective tunneling spin polarization of 0.923.
+The observed large TMR ratios resulted from the fine-tuning of atomic-scale
+structures of the MTJs, such as crystallographic orientations and MgO interface
+oxidation, in which the well-known Delta1 coherent tunneling mechanism for the
+giant TMR effect is expected to be pronounced. However, behavior that is not
+covered by the standard coherent tunneling theory was unexpectedly manifested;
+i.e., (i) TMR saturation at a thick MgO barrier region and (ii) enhanced TMR
+oscillation with a 0.32 nm period in MgO thickness. Particularly, the TMR
+oscillatory behavior dominates the transport in a wide range of MgO
+thicknesses; the peak-to-valley difference of the TMR oscillation exceeded 140%
+at RT, attributable to the appearance of large oscillatory components in
+resistance area product (RA). Further, we found that the oscillatory behaviors
+of the TMR ratio and RA survive, even under a +-1 V bias voltage application,
+indicating the robustness of the oscillation. Our demonstration of the giant
+RT-TMR ratio will be an essential step for establishing spintronic
+architectures, such as large-capacity MRAMs and spintronic artificial neural
+networks. More essentially, the present observations can trigger us to revisit
+the true TMR mechanism in crystalline MTJs.",2202.07847v1
+2022-02-25,Astrophysical Plasma Instabilities induced by Long-Range Interacting Dark Matter,"If dark matter (DM) is millicharged or darkly charged, collective plasma
+processes may dominate momentum exchange over direct particle collisions.
+Plasma streaming instabilities can couple the momentum of the DM to
+counter-streaming baryons or other DM and result in the counter-streaming
+fluids coming to rest with each other, just as happens for baryonic
+collisionless shocks in astrophysical systems. While electrostatic plasma
+instabilities are highly suppressed by Landau damping when DM is millicharged,
+in the cosmological situations of interest, electromagnetic instabilities such
+as the Weibel can couple momenta, assuming that the linear instability
+saturates in the manner typically found for baryonic plasmas. We find that the
+streaming of DM in the pre-Recombination universe is affected more strongly by
+direct collisions than collective processes, validating previous constraints.
+However, when considering magnetized Weibel and Firehose instabilities, the
+properties of the Bullet Cluster merger are likely to be substantially altered
+if $[q_\chi/m_\chi] \gtrsim 10^{-12}-10^{-11}$, where $[q_\chi/m_\chi]$ is the
+charge-to-mass ratio of the DM relative to that of the proton. The Weibel
+growth rates are even faster in the case of a dark-$U(1)$ charge, potentially
+ruling out $[q_\chi/m_\chi] \gtrsim 10^{-14}$ in the Bullet Cluster system, in
+agreement with previous work. The strongest previous limits on millicharged DM
+(mDM) arise from considering the spin-down of galactic disks. We show that
+plasma instabilities or tangled background magnetic fields could lead to
+diffusive propagation of the DM, weakening these spin-down limits. Thus, plasma
+instabilities may place some of the most stringent constraints over much of the
+millicharged, and our results corroborate previous extremely stringent
+potential constraints on the dark-charged parameter space.",2202.12464v2
+2022-04-17,MRXCAT-CDTI: A Numerical Cardiac Diffusion Tensor Imaging Phantom,"Magnetic Resonance cardiac diffusion tensor imaging (cDTI) and cardiac
+intravoxel incoherent motion imaging enables probing of in vivo myofiber
+architecture and myocardial perfusion surrogates. To study the impact of
+experimental parameters such as resolution, off-resonances and heart-rate
+variations, we propose a numerical open-source framework called MRXCAT-CDTI. It
+allows simulating diffusion and perfusion contrast for spin-echo (SE) and
+stimulated echo acquisition mode (STEAM) cDTI sequences. The Fourier encoder
+supports in-plane and/or through-slice off-resonance effects, as well as T2*
+effects during single-shot image encoding. Optional lesions are included to
+mimic ischemic and infarcted myocardial regions. MRXCAT-CDTI allows assessing
+realistic influences on data acquisition, and how these affect the data
+encoding process and subsequent data processing. As an example, heart-rate
+variations lead to differences in partial saturation and relaxation of
+magnetization that end up in errors of 9 to 30% for cDTI angle metrics if not
+accounted for. For SE echo-planar cDTI, in-plane off-resonance effects more
+adversely affect cDTI metrics compared to through-slice off-resonances. With
+this work we propose an open-source MRXCAT-CDTI numerical simulation framework
+that offers realistic image encoding effects found in cardiac diffusion and
+perfusion data to systematically study influences of data encoding,
+reconstruction, and post-processing to promote reproducible research.",2204.07966v1
+2022-12-28,Rossby numbers of fully and partially convective stars,"We investigate stellar magnetic activity from the theoretical point of view,
+by using stellar evolution models to calculate theoretical convective turnover
+times ($\tau_{\rm c}$) and Rossby numbers (${\rm Ro}$) for pre-main-sequence
+and main-sequence stars. The problem is that the canonical place where
+$\tau_{\rm c}$ is usually determined (half a mixing length above the base of
+the convective zone) fails for fully convective stars and there is no agreement
+on this in the literature. Our calculations were performed with the ATON
+stellar evolution code. We concentrated our analysis on fully and partially
+convective stars motivated by recent observations of slowly rotating fully
+convective stars, whose X-ray emissions correlate with their Rossby numbers in
+the same way as in solar-like stars, suggesting that the presence of a
+tachocline is not required for magnetic field generation. We investigate the
+behaviour of $\tau_{\rm c}$ over the stellar radius for stars of different
+masses and ages. As ${\rm Ro}$ depends on $\tau_{\rm c}$, which varies strongly
+with the stellar radius, we use our theoretical results to determine a better
+radial position at which to calculate it for fully convective stars. Using our
+alternative locations, we fit a sample of 847 stars in the rotation-activity
+diagram ($L_{\rm X}/L_{\rm bol}$ versus ${\rm Ro}$) with a two-part power-law
+function. Our fit parameters are consistent with previous work, showing that
+stars with ${\rm Ro}$$\leq$${\rm Ro_{sat}}$ are distributed around a saturation
+level in $L_{\rm X}/L_{\rm bol}$ and, for stars with ${\rm Ro}$$>$${\rm
+Ro_{sat}}$, $L_{\rm X}/L_{\rm bol}$ clearly decays with ${\rm Ro}$ with an
+exponent of $-2.4\!\pm\!0.1$.",2212.13958v1
+2023-01-14,CoRuVSi: A potential candidate for spin semimetal with promising spintronic and thermoelectric properties,"Based on our experimental and theoretical studies, we report the
+identification of the quaternary Heusler alloy, CoRuVSi as a new member of the
+recently discovered spin semimetals class. Spin polarised semimetals possess a
+unique band structure in which one of the spin bands shows semimetallic nature,
+while the other shows semiconducting/insulating nature. Our findings show that
+CoRuVSi possesses interesting spintronic and thermoelectric properties.
+Magnetization data reveal a weak ferri-/antiferro magnetic ordering at low
+temperatures, with only a very small moment $\sim$ 0.13 $\mu_B$/f.u.,
+attributed to the disorder. Transport results provide strong evidence of
+semimetallicity dominated by two-band conduction, while magnetoresistance data
+show a non-saturating, linear, positive, magnetoresistance. Spin polarization
+measurements using point-contact Andreev reflection spectra reveal a reasonably
+high spin polarization of $\sim$ 50\%, which matches fairly well with the
+simulated result. Furthermore, CoRuVSi shows a high thermopower value of $0.7$
+$m Watt/ m-K^{2}$ at room temperature with the dominant contribution from the
+semimetallic bands, rendering it as a promising thermoelectric material as
+well. Our ab-initio simulation not only confirms a unique semimetallic feature,
+but also reveals that the band structure hosts a linear band crossing at $\sim$
+-0.4 eV below the Fermi level incorporated by a band-inversion. In addition,
+the observed topological non-trivial features of the band structure is
+corroborated with the simulated Berry curvature, intrinsic anomalous Hall
+conductivity and the Fermi surface. The coexistence of many interesting
+properties relevant for spintronic, topological and thermoelectric applications
+in a single material is extremely rare and hence this study could promote a
+similar strategy to identify other potential materials belonging to same class.",2301.05854v1
+2023-02-14,Collapsar Black Holes are Likely Born Slowly Spinning,"Collapsing stars constitute the main black hole (BH) formation channel, and
+are occasionally associated with the launch of relativistic jets that power $
+\gamma $-ray bursts (GRBs). Thus, collapsars offer an opportunity to infer the
+natal (before spin-up/down by accretion) BH spin directly from observations. We
+show that once the BH saturates with large-scale magnetic flux, the jet power
+is dictated by the BH spin and mass accretion rate. Core-collapse simulations
+by Halevi et al. 2023 and GRB observations favor stellar density profiles that
+yield an accretion rate $ \dot{m} \approx 10^{-2} M_\odot~{\rm s^{-1}} $,
+weakly dependent on time. This leaves the spin as the main factor that governs
+the jet power. By comparing the jet power to characteristic GRB luminosities,
+we find that the majority of BHs associated with jets are likely born slowly
+spinning with a dimensionless spin $ a \simeq 0.2 $, or $ a \lesssim 0.5 $ for
+wobbling jets, with the main uncertainty originating in the unknown $ \gamma
+$-ray radiative efficiency. This result could be applied to the entire
+core-collapse BH population, unless an anti-correlation between the stellar
+magnetic field and angular momentum is present. In a companion paper,
+Jacquemin-Ide et al. 2023, we show that regardless of the natal spin, the
+extraction of BH rotational energy leads to spin-down to $ a \lesssim 0.2 $,
+consistent with gravitational-wave observations. We verify our results by
+performing the first 3D general relativistic magnetohydrodynamic simulations of
+collapsar jets with characteristic GRB energies, powered by slowly spinning
+BHs. We find that jets of typical GRB power struggle to escape from the star,
+providing the first numerical indication that many jets fail to generate a GRB.",2302.07271v2
+2023-07-04,Critical dynamical behavior of the Ising model,"We investigate the dynamical critical behavior of the two- and
+three-dimensional Ising model with Glauber dynamics in equilibrium. In contrast
+to the usual standing, we focus on the mean-squared deviation of the
+magnetization $M$, MSD$_M$, as a function of time, as well as on the
+autocorrelation function of $M$. These two functions are distinct but closely
+related. We find that MSD$_M$ features a first crossover at time $\tau_1 \sim
+L^{z_{1}}$, from ordinary diffusion with MSD$_M$ $\sim t$, to anomalous
+diffusion with MSD$_M$ $\sim t^\alpha$. Purely on numerical grounds, we obtain
+the values $z_1=0.45(5)$ and $\alpha=0.752(5)$ for the two-dimensional Ising
+ferromagnet. Related to this, the magnetization autocorrelation function
+crosses over from an exponential decay to a stretched-exponential decay. At
+later times, we find a second crossover at time $\tau_2 \sim L^{z_{2}}$. Here,
+MSD$_M$ saturates to its late-time value $\sim L^{2+\gamma/\nu}$, while the
+autocorrelation function crosses over from stretched-exponential decay to
+simple exponential one. We also confirm numerically the value
+$z_{2}=2.1665(12)$, earlier reported as the single dynamic exponent. Continuity
+of MSD$_M$ requires that $\alpha(z_{2}-z_{1})=\gamma/\nu-z_1$. We speculate
+that $z_{1} = 1/2$ and $\alpha = 3/4$, values that indeed lead to the expected
+$z_{2} = 13/6$ result. A complementary analysis for the three-dimensional Ising
+model provides the estimates $z_{1} = 1.35(2)$, $\alpha=0.90(2)$, and $z_{2} =
+2.032(3)$. While $z_{2}$ has attracted significant attention in the literature,
+we argue that for all practical purposes $z_{1}$ is more important, as it
+determines the number of statistically independent measurements during a long
+simulation.",2307.01837v2
+2023-11-30,The Factory and the Beehive. V. Chromospheric and Coronal Activity and Its Dependence on Rotation in Praesepe and the Hyades,"Low-mass (< 1.2 Solar mass) main-sequence stars lose angular momentum over
+time, leading to a decrease in their magnetic activity. The details of this
+rotation-activity relation remain poorly understood. Using observations of
+members of the $\approx$700 Myr-old Praesepe and Hyades open clusters, we aim
+to characterize the rotation-activity relation for different tracers of
+activity at this age. To complement published data, we obtained new optical
+spectra for 250 Praesepe stars, new X-ray detections for ten, and new rotation
+periods for 28. These numbers for Hyads are 131, 23, and 137, respectively. The
+latter increases the number of Hyads with periods by 50%. We used these data to
+measure the fractional H$\alpha$ and X-ray luminosities,
+$\mathit{L}_{H\alpha}/\mathit{L}_{bol}$ and $\mathit{L}_X/\mathit{L}_{bol}$,
+and to calculate Rossby numbers $\mathit{R}_o$. We found that at $\approx$700
+Myr almost all M dwarfs exhibit H$\alpha$ emission, with binaries having the
+same overall color-H$\alpha$ equivalent width distribution as single stars. In
+the $\mathit{R}_o-\mathit{L}_{H\alpha}/\mathit{L}_{bol}$ plane, unsaturated
+single stars follow a power-law with index $\beta = -5.9 \pm 0.8$ for
+$\mathit{R}_o > 0.3$. In the $\mathit{R}_o-\mathit{L}_X/\mathit{L}_{bol}$
+plane, we see evidence for supersaturation for single stars with $\mathit{R}_o
+\lesssim 0.01$, following a power-law with index $\beta_{sup} =
+0.5^{+0.2}_{-0.1}$, supporting the hypothesis that stellar coronae are being
+centrifugally stripped. We found that the critical $\mathit{R}_o$ value at
+which activity saturates is smaller for $\mathit{L}_X/\mathit{L}_{bol}$ than
+for $\mathit{L}_{H\alpha}/\mathit{L}_{bol}$. Finally, we observed an almost 1:1
+relation between $\mathit{L}_{H\alpha}/\mathit{L}_{bol}$ and
+$\mathit{L}_X/\mathit{L}_{bol}$, suggesting that both the corona and the
+chromosphere experience similar magnetic heating.",2311.18690v2
+2023-12-29,Inverse Gertsenshtein effect as a probe of high-frequency gravitational waves,"We apply the inverse Gertsenshtein effect, i.e., the graviton-photon
+conversion in the presence of a magnetic field, to constrain high-frequency
+gravitational waves (HFGWs). Using existing astrophysical measurements, we
+compute upper limits on the GW energy densities $\Omega_{\rm GW}$ at 16
+different frequency bands. Given the observed magnetisation of galaxy clusters
+with field strength $B\sim\mu{\rm G}$ correlated on $\mathcal{O}(10)\,{\rm
+kpc}$ scales, we estimate HFGW constraints in the $\mathcal{O}(10^2)\,{\rm
+GHz}$ regime to be $\Omega_{\rm GW}\lesssim10^{16}$ with the temperature
+measurements of the Atacama Cosmology Telescope (ACT). Similarly, we
+conservatively obtain $\Omega_{\rm GW}\lesssim10^{13} (10^{11})$ in the
+$\mathcal{O}(10^2)\,{\rm MHz}$ ($\mathcal{O}(10)\,{\rm GHz}$) regime by
+assuming uniform magnetic field with strength $B\sim0.1\,{\rm nG}$ and
+saturating the excess signal over the Cosmic Microwave Background (CMB)
+reported by radio telescopes such as the Experiment to Detect the Global EoR
+Signature (EDGES), LOw Frequency ARray (LOFAR), and Murchison Widefield Array
+(MWA), and the balloon-borne second generation Absolute Radiometer for
+Cosmology, Astrophysics, and Diffuse Emission (ARCADE2) with graviton-induced
+photons. Although none of these existing constraints fall below the critical
+value of $\Omega_{\rm GW} = 1$ or reaches the Big Bang Nucleosynthesis (BBN)
+bound of $\Omega_{\rm GW}\simeq1.2\times10^{-6}$, the upcoming Square Kilometer
+Array (SKA) can improve the sensitivities by roughly 10 orders of magnitude and
+potentially become realistic probes of HFGWs. We also explore several
+next-generation CMB surveys, including Primordial Inflation Explorer (PIXIE),
+Polarized Radiation Interferometer for Spectral disTortions and INflation
+Exploration (PRISTINE) and Voyage 2050, that could potentially provide
+constraints competitive to the current BBN bound.",2312.17636v1
+2007-03-28,Nuclear Saturation and Correlations,"The relation between nuclear saturation and NN-correlations is examined.
+Nucleons bound in a nucleus have a reduced effective mass due to the mean
+field. This results in off-energy-shell scatterings modifying the free-space
+NN-interaction by a dispersion correction. This is a major contribution to the
+density-dependence of the effective in-medium force and to saturation.
+Low-momentum effective interactions have been derived by renormalisation
+methods whereby correlations may be reduced by effectively cutting off high
+momentum components of the interaction. The effect of these cut-offs on
+dispersive corrections and on saturation is the main focus of this paper. The
+role of the tensor-force, its strength and its effect on correlations is of
+particular interest. The importance of the definition of the mean field in
+determining saturation as well as compressibility is also pointed out.
+  With a cut-off below $\sim 2.6 fm^{-1}$ there is no saturation but at lower
+density the binding energy is still well approximated suggesting that such a
+force may be useful in nuclear structure calculations of (small) finite nuclei
+if saturation is not an issue.
+  A separable interaction that fits experimental phase-shifts exactly by
+inverse scattering methods is used. Recent experiments measure short ranged
+correlations (SRC's) to be 0.23 for $^{56}Fe$. Other experiments have obtained
+a depletion of occupation-numbers in $^{208}Pb$ to be $\sim 0.2$. For nuclear
+matter with the separable interaction and a continuous spectrum we obtain the
+related quantity $\kappa$ to be 0.175 with the Bonn-B deuteron parameters,
+while Machleidt's gets $\kappa= 0.125$ for the Bonn-B potential and a
+continuous spectrum.",0703093v1
+2008-11-06,The saturation scale and its x-dependence from Lambda polarization studies,"The transverse polarization of forward Lambda hyperons produced in
+high-energy p-A collisions is expected to display an extremum at a transverse
+momentum around the saturation scale. This was first observed within the
+context of the McLerran-Venugopalan model which has an x-independent saturation
+scale. The extremum arises due to the k_t-odd nature of the polarization
+dependent fragmentation function, which probes approximately the derivative of
+the dipole scattering amplitude. The amplitude changes most strongly around the
+saturation scale, resulting in a peak in the polarization. We find that the
+observation also extends to the more realistic case in which the saturation
+scale Q_s is x dependent. Since a range of x and therefore Q_s values is probed
+at a given transverse momentum and rapidity, this result is a priori not
+expected. Moreover, the measurement of Lambda polarization over a range of x_F
+values actually provides a direct probe of the x dependence of the saturation
+scale. This novel feature is demonstrated for typical LHC kinematics and for
+several phenomenological models of the dipole scattering amplitude. We show
+that although the measurement will be challenging, it may be feasible at LHC.
+The situation at RHIC is not favorable, because the peak will likely be at too
+low transverse momentum of the Lambda to be a trustworthy measure of the
+saturation scale.",0811.0998v1
+2014-02-19,Exclusive vector meson production at high energies and gluon saturation,"We systematically study exclusive diffractive (photo) production of vector
+mesons ($J/\psi$, $\psi(2s)$, $\phi$ and $\rho$) off protons in high-energy
+collisions and investigate whether the production is a sensitive probe of gluon
+saturation. We confront saturation-based results for diffractive $\psi(2s)$ and
+$\rho$ production at HERA and $J/\psi$ photoproduction with all available data
+including recent ones from HERA, ALICE and LHCb, finding good agreement. In
+particular, we show that the $t$-distribution of differential cross sections of
+photoproduction of vector mesons offers a unique opportunity to discriminate
+among saturation and non-saturation models. This is due to the emergence of a
+pronounced dip (or multiple dips) in the $t$-distribution of diffractive
+photoproduction of vector mesons at relatively large, but potentially
+accessible $|t|$ that can be traced back to the unitarity features of colour
+dipole amplitude in the saturation regime. We show that in saturation models
+the dips in $t$-distribution recede towards lower $|t|$ with decreasing mass of
+the vector meson, increasing energy or decreasing Bjorken-$x$, and decreasing
+virtuality $Q$. We provide various predictions for exclusive (photo) production
+of different vector mesons including the ratio of $\psi(2s)/J/\psi$ at HERA,
+the LHC, and future colliders.",1402.4831v3
+2015-03-06,Graphs with induced-saturation number zero,"Given graphs $G$ and $H$, $G$ is $H$-saturated if $H$ is not a subgraph of
+$G$, but for all $e \notin E(G)$, $H$ appears as a subgraph of $G + e$. While
+for every $n \ge |V(H)|$, there exists an $n$-vertex graph that is
+$H$-saturated, the same does not hold for induced subgraphs. That is, there
+exist graphs $H$ and values of $n \ge |V(H)|$ for which every $n$-vertex graph
+$G$ either contains $H$ as an induced subgraph, or there exists $e \notin E(G)$
+such that $G + e$ does not contain $H$ as an induced subgraph. To circumvent
+this, Martin and Smith make use of trigraphs when introducing the concept of
+induced saturation and the induced saturation number of graphs. This allows for
+edges that can be included or excluded when searching for an induced copy of H,
+and the induced saturation number is the minimum number of such edges that are
+required.
+  In this paper, we show that the induced saturation number of many common
+graphs is zero. Consequently, this yields graphs, instead of trigraphs, that
+are H-induced-saturated. We introduce a new parameter for such graphs,
+indsat*(n;H), which is the minimum number of edges in an H-induced-saturated
+graph on n vertices. We provide bounds on indsat*(n;H) for many graphs. In
+particular, we determine indsat*(n;paw) completely, and indsat*(n;$K_{1,3}$)
+for infinitely many n.",1503.02105v1
+2015-07-03,Over Saturation in SiPMs: The Difference Between Signal Charge and Signal Amplitude,"A recent report on the over saturation in SiPMs is puzzling. The
+measurements, using a variety of SiPMs, show an excess in signal far beyond the
+physical limit of the number of SiPM microcells without indication of an
+ultimate saturation. In this work I propose a solution to this problem.
+Different measurements and theoretical models of avalanche propagation indicate
+that multiple simultaneous primary avalanches produce an ever narrower and
+faster signal. This is because of a speed-up of effective avalanche propagation
+processes. It means that SiPMs, operated at their saturation regime, should
+become faster the more light they detect. Therefore, signal extraction methods
+that use the amplitude of the signal should see an over saturation effect.
+Measurements with a commercial SiPM illuminated with bright picosecond pulses
+in the saturation regime demonstrate that indeed the rising edge of the SiPM
+signal gets faster as the light pulses get brighter. A signal extractor based
+on the amplitude shows a nonlinear behavior in comparison to an integrating
+charge extractor. This supports the proposed solution for the over saturation
+effect. Furthermore I show that this effect can already be seen with a
+bandwidth of 300MHz, which means that it should be taken into account for fast
+sampling experiments.",1507.00863v1
+2015-11-02,Saturation Power based Simple Energy Efficiency Maximization Schemes for MU-MISO Systems,"In this paper, we investigate an energy efficiency (EE) maximization problem
+in multi-user multiple input single output downlink channels. The optimization
+problem in this system model is difficult to solve in general, since it is in
+non-convex fractional form. Hence, conventional algorithms have addressed the
+problem in an iterative manner for each channel realization, which leads to
+high computational complexity. To tackle this complexity issue, we propose a
+new simple method by utilizing the fact that the EE maximization is identical
+to the spectral efficiency (SE) maximization for the region of the power below
+a certain transmit power referred to as saturation power. In order to calculate
+the saturation power, we first introduce upper and lower bounds of the EE
+performance by adopting a maximal ratio transmission beamforming strategy.
+Then, we propose an efficient way to compute the saturation power for the EE
+maximization problem. Once we determine the saturation power corresponding to
+the maximum EE in advance, we can solve the EE maximization problem with SE
+maximization schemes with low complexity. The derived saturation power is
+parameterized by employing random matrix theory, which relies only on the
+second order channel statistics. Hence, this approach requires much lower
+computational complexity compared to a conventional scheme which exploits
+instantaneous channel state information, and provides insight on the saturation
+power. Numerical results validate that the proposed algorithm achieves near
+optimal EE performance with significantly reduced complexity.",1511.00446v2
+2015-11-03,Quantum hacking: saturation attack on practical continuous-variable quantum key distribution,"We identify and study a new security loophole in continuous-variable quantum
+key distribution (CV-QKD) implementations, related to the imperfect linearity
+of the homodyne detector. By exploiting this loophole, we propose an active
+side-channel attack on the Gaussian-modulated coherent state CV-QKD protocol
+combining an intercept-resend attack with an induced saturation of the homodyne
+detection on the receiver side (Bob). We show that an attacker can bias the
+excess noise estimation by displacing the quadratures of the coherent states
+received by Bob. We propose a saturation model that matches experimental
+measurements on the homodyne detection and use this model to study the impact
+of the saturation attack on parameter estimation in CV-QKD.We demonstrate that
+this attack can bias the excess noise estimation beyond the null key threshold
+for any system parameter, thus leading to a full security break. If we consider
+an additional criteria imposing that the channel transmission estimation should
+not be affected by the attack, then the saturation attack can only be launched
+if the attenuation on the quantum channel is sufficient, corresponding to
+attenuations larger than approximately 6 dB. We moreover discuss the possible
+counter-measures against the saturation attack and propose a new counter-
+measure based on Gaussian post-selection that can be implemented by classical
+post-processing and may allow to distill secret key when the raw measurement
+data is partly saturated.",1511.01007v1
+2016-07-04,CGC/saturation approach: a new impact-parameter dependent model in the next-to-leading order of perturbative QCD,"This paper is the first attempt to build CGC/saturation model based on the
+next-to-leading order corrections to linear and non-linear evolution in QCD. We
+assume that the renormalization scale is the saturation momentum and found that
+the scattering amplitude has geometric scaling behaviour deep in the saturation
+domain with the explicit formula of this behaviour at large $\tau = r^2 Q^2_s$.
+We built a model that include this behaviour, as well as the ingredients that
+has been known: (i) the behaviour of the scattering amplitude in the vicinity
+of the saturation momentum, using the NLO BFKL kernel, (ii) the pre-asymptotic
+behaviour of $\ln\Lb Q^2_s\Lb Y \Rb\Rb$, as function of $Y$ and (iii) the
+impact parameter behaviour of the saturation momentum, which has exponential
+behaviour $\propto \exp\Lb -\, m\, b\Rb$ at large $b$.We demonstrated that the
+model is able to describe the experimental data for the deep inelastic
+structure function. Despite this, our model has difficulties that are related
+to the small value of the QCD coupling at $Q_s\Lb Y_0\Rb$ and the large values
+of the saturation momentum, which indicate the theoretical inconsistency of our
+description.",1607.00832v2
+2017-10-10,Experimental investigation of water distribution in two-phase zone during gravity-dominated evaporation,"We characterize the water repartition within the partially saturated
+(two-phase) zone (PSZ) during evaporation out of mixed wettable porous media by
+controlling the wettability of glass beads, their sizes, and as well the
+surrounding relative humidity. Here, Capillary numbers are low and under these
+conditions, the percolating front is stabilized by gravity. Using experimental
+and numerical analyses, we find that the PSZ saturation decreases with the Bond
+number, where packing of smaller particles have higher saturation values than
+packing made of larger particles. Results also reveal that the extent (height)
+of the PSZ, as well as water saturation in the PSZ, both increase with
+wettability. We also numerically calculate the saturation exclusively contained
+in connected liquid films and results show that values are less than the
+expected PSZ saturation. These results strongly reflect that the two-phase zone
+is not solely made up of connected capillary networks, but also made of
+disconnected water clusters or pockets. Moreover, we also find that global
+saturation (PSZ + full wet zone) decreases with wettability, confirming that
+greater quantity of water is lost via evaporation with increasing
+hydrophilicity. These results show that connected liquid films are favored in
+more hydrophilic systems while disconnected water pockets are favored in less
+hydrophilic systems.",1710.03831v1
+2019-07-25,Experimental study of the non-linear saturation of the elliptical instability: inertial wave turbulence versus geostrophic turbulence,"In this paper, we present an experimental investigation of the turbulent
+saturation of the flow driven by parametric resonance of inertial waves in a
+rotating fluid. In our set-up, a half-meter wide ellipsoid filled with water is
+brought to solid body rotation, and then undergoes sustained harmonic
+modulation of its rotation rate. This triggers the exponential growth of a pair
+of inertial waves via a mechanism called the libration-driven elliptical
+instability. Once the saturation of this instability is reached, we observe a
+turbulent state for which energy is injected into the resonant inertial waves
+only. Depending on the amplitude of the rotation rate modulation, two different
+saturation states are observed. At large forcing amplitudes, the saturation
+flow mainly consists of a steady, geostrophic anticyclone. Its amplitude
+vanishes as the forcing amplitude is decreased while remaining above the
+threshold of the elliptical instability. Below this secondary transition, the
+saturation flow is a superposition of inertial waves which are in weakly
+non-linear resonant interaction, a state that could asymptotically lead to
+inertial wave turbulence. In addition to being a first experimental observation
+of a wave-dominated saturation in unstable rotating flows, the present study is
+also an experimental confirmation of the model of Le Reun et al, PRL (2017) who
+introduced the possibility of these two turbulent regimes. The transition
+between these two regimes and their relevance to geophysical applications are
+finally discussed.",1907.10907v3
+2020-11-01,Multiplicity-dependent saturation momentum in $p$-Pb collisions at 5.02 TeV,"Semi-inclusive transverse momentum spectra observed in proton-proton and
+proton-lead nuclear collisions at LHC energies obey a geometric scaling with a
+scaling variable using multiplicity-dependent saturation momentum. The
+saturation momentum extracted from the experimental data is proportional to the
+1/6 power of the hadron multiplicity in the final state. On the other hand, the
+system's transverse size is proportional to the 1/3 power of the multiplicity,
+and the saturation momentum and the transverse size of the system are strongly
+correlated with the hadron multiplicity in the final state. Since the
+saturation momentum is proportional to the average transverse momentum of
+hadrons, one predicts average transverse momentum is also proportional to the
+1/6 power of the multiplicity, which is consistent with experimental results at
+the LHC energy. We found that a nuclear modification factor $R_{\rm pPb}$
+calculated by the multiplicity-dependent saturation momentum decreases at
+$p_{\rm T} \lesssim$ 1GeV/$c$ and that our model can partially explain the
+$R_{\rm pPb}$'s behavior thought to be caused by nuclear shadowing. On the
+other hand, Cronin enhancement experimentally observed at $2 \lesssim p_{\rm T}
+\lesssim $ 6 GeV/$c$ is not reproduced. However, the experimental result,
+including the Cronin effect, can be reproduced well by introducing $p_{\rm T}$
+dependence as a 4$\sim$5\% correction to the multiplicity-dependent saturation
+momentum.We also discuss a relation between the geometric scaling in the
+semi-inclusive distributions and the string percolation model.",2011.00456v2
+2022-01-24,Methane-saturated layers limit the observability of impact craters on Titan,"As the only icy satellite with a thick atmosphere and liquids on its surface,
+Titan represents a unique end-member to study the impact cratering process.
+Unlike craters on other Saturnian satellites, Titan's craters are
+preferentially located in high-elevation regions near the equator. This led to
+the hypothesis that the presence of liquid methane in Titan's lowlands affects
+crater morphology, making them difficult to identify. This is because surfaces
+covered by weak fluid-saturated sediment limit the topographic expression of
+impact craters, as sediment moves into the crater cavity shortly after
+formation. Here we simulate crater-forming impacts on Titan's surface,
+exploring how a methane-saturated layer overlying a methane-clathrate layer
+affects crater formation. Our numerical results show that impacts form smaller
+craters in a methane-clathrate basement than a water-ice basement, due to the
+differences in strength. We find that the addition of a methane-saturated layer
+atop this basement reduces crater depths and influences crater morphology. The
+morphology of impact craters formed in a thin methane-saturated layer are
+similar to those in a ""dry"" target, but a thick saturated layer produces an
+impact structure with little to no topography. A thick methane-saturated layer
+(thicker than 40% of the impactor diameter) could explain the dearth of craters
+in the low-elevation regions on Titan.",2201.09587v1
+2022-11-02,How to minimize the environmental contamination caused by hydrocarbon releases by onshore pipelines: The key role of a three-dimensional three-phase fluid flow numerical model,"The contamination impact and the migration of the contaminant into the
+surrounding environment due to the presence of a spilled oil pipeline will
+cause significant damage to the natural ecosystem. For this reason, it is
+decisive to develop a rapid response strategy that might include accurate
+predictions of oil migration trajectories from numerical simulation modeling.
+In this paper, a three-dimensional model based on a high-resolution
+shock-capturing conservative method to resolve the nonlinear governing partial
+differential equations of the migration of a spilled light nonaqueous liquid
+oil contaminant in a variably saturated zone is employed to investigate the
+migration of the oil pipeline leakage with great accuracy. The effects on the
+oil type density, gasoline and diesel oil, the unsaturated zone depth, its
+saturation, the hydraulic gradient, and the pressure oil pipeline are
+investigated through the temporal evolution of the contaminant migration
+following the saturation profiles of the three-phase fluids flow in the
+variably saturated zone. The calculation results indicate that the leaking
+oil's pressure is the parameter that significantly affects the contaminants'
+arrival time to the groundwater table. Also, the water saturation of the
+unsaturated zone influences the arrival time as the water saturation increases
+for a fixed depth. The unsaturated zone depth significantly influences the
+contaminant migration unsaturated zone. At the same time, the oil density and
+the hydraulic gradient have limited effects on the contaminant migration in the
+variably saturated zone.",2211.01279v1
+2022-07-22,Accelerated and Quantitative 3D Semisolid MT/CEST Imaging using a Generative Adversarial Network (GAN-CEST),"Purpose: To substantially shorten the acquisition time required for
+quantitative 3D chemical exchange saturation transfer (CEST) and semisolid
+magnetization transfer (MT) imaging and allow for rapid chemical exchange
+parameter map reconstruction. Methods: Three-dimensional CEST and MT magnetic
+resonance fingerprinting (MRF) datasets of L-arginine phantoms, whole-brains,
+and calf muscles from healthy volunteers, cancer patients, and cardiac patients
+were acquired using 3T clinical scanners at 3 different sites, using 3
+different scanner models and coils. A generative adversarial network supervised
+framework (GAN-CEST) was then designed and trained to learn the mapping from a
+reduced input data space to the quantitative exchange parameter space, while
+preserving perceptual and quantitative content. Results: The GAN-CEST 3D
+acquisition time was 42-52 seconds, 70% shorter than CEST-MRF. The quantitative
+reconstruction of the entire brain took 0.8 seconds. An excellent agreement was
+observed between the ground truth and GAN-based L-arginine concentration and pH
+values (Pearson's r > 0.97, NRMSE < 1.5%). GAN-CEST images from a brain-tumor
+subject yielded a semi-solid volume fraction and exchange rate NRMSE of
+3.8$\pm$1.3% and 4.6$\pm$1.3%, respectively, and SSIM of 96.3$\pm$1.6% and
+95.0$\pm$2.4%, respectively. The mapping of the calf-muscle exchange parameters
+in a cardiac patient, yielded NRMSE < 7% and SSIM > 94% for the semi-solid
+exchange parameters. In regions with large susceptibility artifacts, GAN-CEST
+has demonstrated improved performance and reduced noise compared to MRF.
+Conclusion: GAN-CEST can substantially reduce the acquisition time for
+quantitative semisolid MT/CEST mapping, while retaining performance even when
+facing pathologies and scanner models that were not available during training.",2207.11297v2
+2005-02-21,Aperture Photometry of Saturated Star Images from Digitised Photographic Plates,"Saturated stellar images on digitised photographic plates are many times
+greater in area than the `seeing disk' seen in unsaturated CCD images. Indeed
+the flux profile of a bright star can be traced out for several degrees from
+the star's centre. The radius of the saturated stellar image can often be
+directly related to the magnitude of the star, a fact well known and exploited
+in iris photometry. In this work we compare the radial flux profile of stars in
+the approximate range B ~9 to ~13 mag, obtained from scans of plates from the
+Bamberg Sky Patrol archive, with a profile of the form measured by King. We
+show that simple aperture photometry of saturated stellar images, obtained from
+photo-positives of scanned photographic plates, yield data that are in
+agreement with simulations using a (saturated) synthetic stellar radius
+profile. Raw plate magnitudes from this aperture photometry can be easily and
+satisfactorily transformed to standard magnitudes, as demonstrated in a recent
+study carried out by the current authors.",0502411v1
+1999-06-29,Enhanced Saturation Coverages in Adsorption-Desorption Processes,"Many experimental studies of protein deposition on solid surfaces involve
+alternating adsorption/desorption steps. In this paper, we investigate the
+effect of a desorption step (separating two adsorption steps) on the kinetics,
+the adsorbed-layer structure, and the saturation density. Our theoretical
+approach involves a density expansion of the pair distribution function and an
+application of an interpolation formula to estimate the saturation density as a
+function of the density at which the desorption process commences, $\rho_1$,
+and the density of the depleted configuration, $\rho_2$. The theory predicts an
+enhancement of the saturation density compared with that of a simple,
+uninterrupted RSA process and a maximum in the saturation density when
+$\rho_2={2/3}\rho_1$. The theoretical results are in qualitative and in
+semi-quantitative agreement with the results of numerical simulations.",9906429v1
+2002-04-22,Dynamic scaling and universality in evolution of fluctuating random networks,"We found that models of evolving random networks exhibit dynamic scaling
+similar to scaling of growing surfaces. It is demonstrated by numerical
+simulations of two variants of the model in which nodes are added as well as
+removed [Phys. Rev. Lett. 83, 5587 (1999)]. The averaged size and connectivity
+of the network increase as power-laws in early times but later saturate.
+Saturated values and times of saturation change with paramaters controlling the
+local evolution of the network topology. Both saturated values and times of
+saturation obey also power-law dependences on controlling parameters. Scaling
+exponents are calculated and universal features are discussed.",0204476v2
+1996-05-14,Large multiplicity fluctuations and saturation effects in onium collisions,"This paper studies two related questions in high energy onium-onium
+scattering: the probability of producing an unusually large number of particles
+in a collision, where it is found that the cross section for producing a
+central multiplicity proportional to $k$ should decrease exponentially in
+$\sqrt{k}$. Secondly, the nature of gluon (dipole) evolution when dipole
+densities become so high that saturation effects due to dipole-dipole
+interactions become important: measures of saturation are developed to help
+understand when saturation becomes important, and further information is
+obtained by exploiting changes of frame, which interchange unitarity and
+saturation corrections.",9605302v1
+2001-06-21,Quarkonium suppression as a probe of a saturated gluon plasma ?,"A dense parton system is expected to be formed in the early stage of
+relativistic heavy-ion collisions at RHIC energies and above. The probability
+of a quark gluon plasma production and the resulting strength of its signatures
+depends strongly on the initial conditions associated to the distributions of
+partons in the nuclear wave functions. At very high energies, the growth of
+parton distributions should saturate, possibly forming a Color Glass
+Condensate, which is characterized by a bulk momentum scale $Q_s$. As a direct
+consequence, the possible signatures of the QGP should be $Q_s$-dependent if
+the saturation scenario is valid for RHIC and LHC. In this Letter we assume the
+saturation scenario for the QGP formation and estimate the saturation scale
+dependence of quarkonium suppression. We conclude that, if this scenario is
+valid, the $\Upsilon$ suppression only occurs at large values of $Q_s$.",0106244v1
+2002-01-30,Conformal invariant saturation,"We show that, in onium-onium scattering at (very) high energy, a transition
+to saturation happens due to quantum fluctuations of QCD dipoles. This
+transition starts when the order $\alpha^2$ correction of the dipole loop is
+compensated by its faster energy evolution, leading to a negative interference
+with the tree level amplitude. After a derivation of the the one-loop dipole
+contribution using conformal invariance of the elastic 4-gluon amplitude in
+high energy QCD, we obtain an exact expression of the saturation line in the
+plane (Y,L) where Y is the total rapidity and L, the logarithm of the onium
+scale ratio. It shows universal features implying the Balitskyi - Fadin -
+Kuraev - Lipatov (BFKL) evolution kernel and the square of the QCD triple
+Pomeron vertex. For large L, only the higher BFKL Eigenvalue contributes,
+leading to a saturation depending on leading log perturbative QCD
+characteristics. For initial onium scales of same order, however, it involves
+an unlimited summation over all conformal BFKL Eigenstates. In all cases,
+conformal invariance is preserved for the saturation mechanism based on dipole
+loops.",0201285v2
+2002-12-04,Saturation Effects in Hadronic Cross Sections,"We compute total and differential elastic cross sections of high-energy
+hadronic collisions in the loop-loop correlation model that provides a unified
+description of hadron-hadron, photon-hadron, and photon-photon reactions. The
+impact parameter profiles of pp and gamma*p collisions are calculated. For
+ultra-high energies the hadron opacity saturates at the black disc limit which
+tames the growth of the hadronic cross sections in agreement with the Froissart
+bound. We compute the impact parameter dependent gluon distribution of the
+proton xG(x,Q^2,b) and find gluon saturation at small Bjorken x. These
+saturation effects manifest S-matrix unitarity in hadronic collisions and
+should be observable in future cosmic ray and accelerator experiments at
+ultra-high energies. The c.m. energies and Bjorken x at which saturation sets
+in are determined and LHC and THERA predictions are given.",0212070v1
+2003-03-04,Nonlinear kT factorization for Forward Dijets in DIS off Nuclei in the Saturation Regime,"We develop the QCD description of the breakup of photons into forward dijets
+in small-x deep inelastic scattering off nuclei in the saturation regime. Based
+on the color dipole approach, we derive a multiple scattering expansion for
+intranuclear distortions of the jet-jet transverse momentum spectrum. A special
+attention is paid to the non-Abelian aspects of the propagation of color
+dipoles in a nuclear medium. We report a nonlinear $k_{\perp}$-factorization
+formula for the breakup of photons into dijets in terms of the collective
+Weizs\""acker-Williams (WW) glue of nuclei as defined in ref.
+\cite{Saturation,NSSdijet}. For hard dijets with the transverse momenta above
+the saturation scale the azimuthal decorrelation (acoplanarity) momentum is of
+the order of the nuclear saturation momentum QA. For minijets with the
+transverse momentum below the saturation scale the nonlinear kT-factorization
+predicts a complete disappearance of the jet-jet correlation. We comment on a
+possible relevance of the nuclear decorrelation of jets to the experimental
+data from the STAR-RHIC Collaboration.",0303024v1
+2003-03-19,Saturation of nuclear matter and short-range correlations,"A fully self-consistent treatment of short-range correlations in nuclear
+matter is presented. Different implementations of the determination of the
+nucleon spectral functions for different interactions are shown to be
+consistent with each other. The resulting saturation densities are closer to
+the empirical result when compared with (continuous-choice)
+Brueckner-Hartree-Fock values. Arguments for the dominance of short-range
+correlations in determining the nuclear-matter saturation density are
+presented. A further survey of the role of long-range correlations suggests
+that the inclusion of pionic contributions to ring diagrams in nuclear matter
+leads to higher saturation densities than empirically observed. A possible
+resolution of the nuclear-matter saturation problem is suggested.",0303047v1
+2007-04-12,Saturated actions by finite dimensional Hopf *-algebras on C*-algebras,"If a finite group action $\alpha$ on a unital $C^*$-algebra $M$ is saturated,
+the canonical conditional expectation $E:M\to M^\alpha$ onto the fixed point
+algebra is known to be of index finite type with $Index(E)=|G|$ in the sense of
+Watatani. More generally if a finite dimensional Hopf $*$-algebra $A$ acts on
+$M$ and the action is saturated, the same is true with $Index (E)=\dim(A)$. In
+this paper we prove that the converse is true. Especially in case $M$ is a
+commutative $C^*$-algebra $C(X)$ and $\alpha$ is a finite group action, we give
+an equivalent condition in order that the expectation $E:C(X)\to C(X)^\alpha$
+is of index finite type, from which we obtain that $\alpha$ is saturated if and
+only if $G$ acts freely on $X$.
+  Actions by compact groups are also considered to show that the gauge action
+$\gamma$ on a graph $C^*$-algebra $C^*(E)$ associated with a locally finite
+directed graph $E$ is saturated.",0704.1549v1
+2007-10-21,On the Behavior of the Distributed Coordination Function of IEEE 802.11 with Multirate Capability under General Transmission Conditions,"The aim of this paper is threefold. First, it presents a multi-dimensional
+Markovian state transition model characterizing the behavior of the IEEE 802.11
+protocol at the Medium Access Control layer which accounts for packet
+transmission failures due to channel errors modeling both saturated and
+non-saturated traffic conditions. Second, it provides a throughput analysis of
+the IEEE 802.11 protocol at the data link layer in both saturated and
+non-saturated traffic conditions taking into account the impact of both the
+physical propagation channel and multirate transmission in Rayleigh fading
+environment. The general traffic model assumed is M/M/1/K. Finally, it shows
+that the behavior of the throughput in non-saturated traffic conditions is a
+linear combination of two system parameters; the payload size and the packet
+rates, $\lambda^{(s)}$, of each contending station. The validity interval of
+the proposed model is also derived.
+  Simulation results closely match the theoretical derivations, confirming the
+effectiveness of the proposed models.",0710.3955v1
+2009-04-01,Long-time saturation of the Loschmidt echo in quantum chaotic billiards,"The Loschmidt echo (LE) (or fidelity) quantifies the sensitivity of the time
+evolution of a quantum system with respect to a perturbation of the
+Hamiltonian. In a typical chaotic system the LE has been previously argued to
+exhibit a long-time saturation at a value inversely proportional to the
+effective size of the Hilbert space of the system. However, until now no
+quantitative results have been known and, in particular, no explicit expression
+for the proportionality constant has been proposed. In this paper we perform a
+quantitative analysis of the phenomenon of the LE saturation and provide the
+analytical expression for its long-time saturation value for a semiclassical
+particle in a two-dimensional chaotic billiard. We further perform extensive
+(fully quantum mechanical) numerical calculations of the LE saturation value
+and find the numerical results to support the semiclassical theory.",0904.0172v1
+2009-09-14,Nuclear modification factor in p+pb collisions at LHC and saturation,"We provide predictions for the nuclear modification factor R_{pA} for pions
+and direct photon production in p+A collisions at LHC energy at midrapidity
+within different saturation models fitted to HERA data. In our approach we have
+no free parameters to adjust and all model parameters are fitted to other
+reactions. Our approach gives a rather good description of PHENIX data for
+R_{pA} for pions. We show that, in various saturation models, the pion Cronin
+enhancement is replaced by a moderate suppression at LHC energy at midrapidity
+due to gluon shadowing effects. However, Cronin enhancement of direct photons
+can survive at LHC energy in models with a larger saturation scale. We show
+that both shadowing and saturation effects are important at LHC in p+A
+collisions and give rise to a rather sizable effect in the nuclear modification
+factor R_{pA}. Therefore, a precise measurement of p+A collisions at LHC is
+crucial in order to understand the underlying dynamics of heavy ion collisions.",0909.2664v2
+2010-03-12,Inelastic Scattering and Current Saturation in Graphene,"We present a study of transport in graphene devices on polar insulating
+substrates by solving the Bolzmann transport equation in the presence of
+graphene phonon, surface polar phonon, and Coulomb charged impurity scattering.
+The value of the saturated velocity shows very weak dependence on the carrier
+density, the nature of the insulating substrate, and the low-field mobility,
+varied by the charged impurity concentration. The saturated velocity of 4 - 8 x
+10^7 cm/s calculated at room temperature is significantly larger than reported
+experimental values. The discrepancy is due to the self-heating effect which
+lowers substantially the value of the saturated velocity. We predict that by
+reducing the insulator oxide thickness, which limits the thermal conductance,
+the saturated currents can be significantly enhanced. We also calculate the
+surface polar phonon contribution to the low-field mobility as a function of
+carrier density, temperature, and distance from the substrate.",1003.2455v1
+2010-05-06,Can the nuclear symmetry potential at supra-saturation densities be negative?,"In the framework of an Isospin-dependent Boltzmann-Uehling-Uhlenbeck (IBUU)
+transport model, for the central $^{197}$Au+$^{197}$Au reaction at an incident
+beam energy of 400 MeV/nucleon, effect of nuclear symmetry potential at
+supra-saturation densities on the pre-equilibrium clusters emission is studied.
+It is found that for the positive symmetry potential at supra-saturation
+densities the neutron to proton ratio of lighter clusters with mass number
+$A\leq3$ ($(n/p)_{A\leq3}$) is larger than that of the weighter clusters with
+mass number $A>3$ ($(n/p)_{A>3}$), whereas for the negative symmetry potential
+at supra-saturation densities the $(n/p)_{A\leq3}$ is \emph{smaller} than that
+of the $(n/p)_{A>3}$. This may be considered as a probe of the negative
+symmetry potential at supra-saturation densities.",1005.0962v1
+2010-05-15,Mobility and Saturation Velocity in Graphene on SiO2,"We examine mobility and saturation velocity in graphene on SiO2 above room
+temperature (300-500 K) and at high fields (~1 V/um). Data are analyzed with
+practical models including gated carriers, thermal generation, ""puddle"" charge,
+and Joule heating. Both mobility and saturation velocity decrease with rising
+temperature above 300 K, and with rising carrier density above 2x10^12 cm^-2.
+Saturation velocity is >3x10^7 cm/s at low carrier density, and remains greater
+than in Si up to 1.2x10^13 cm^-2. Transport appears primarily limited by the
+SiO2 substrate, but results suggest intrinsic graphene saturation velocity
+could be more than twice that observed here.",1005.2711v2
+2010-07-13,A variational approach for the deformation of a saturated porous solid. A second-gradient theory extending Terzaghi's effective stress principle,"The principle of virtual power is used to derive the equilibrium field
+equations of a porous solid saturated with a fluid, including second
+density-gradient effects; the intention is the elucidation and extension of the
+effective stress principle of Terzaghi and Fillunger. In the context of a first
+density-gradient theory for a saturated solid we interpret the porewater
+pressure as a Lagrange multiplier in the expression for the deformation energy,
+assuring that the saturation constraint is verified. We prove that this
+saturation pressure is distributed among the constituents according their
+respective volume fraction (Delesse law) only if they are both true
+density-preserving.",1007.2084v1
+2011-01-18,Saturation of Hadron Production in Proton-(anti)Proton Collisions at Low Pt,"Experimental data on inclusive cross sections of the hadrons produced in high
+energy proton-(anti)proton collisions are analyzed in the z-scaling approach.
+Saturation of the scaling function PSI(z) for z<0.1 (low transverse momenta)
+was found. The first results on charged hadron spectra in pp collisions
+obtained by the CMS Collaboration at the LHC have confirmed the saturation down
+to the value of z=0.05. The CMS data on neutral K-meson production at s^{1/2}=7
+TeV extend the saturation region even to a lower value of z=0.002 in the new
+energy domain. A microscopic scenario of hadron production at a constituent
+level based on the z-scaling is discussed in the saturation regime.",1101.3439v1
+2011-02-03,"A Model of Electrowetting, Reversed Electrowetting and Contact Angle Saturation","While electrowetting has many applications, it is limited at large voltages
+by contact angle saturation - a phenomenon that is still not well understood.
+We propose a generalized approach for electrowetting that, among other results,
+can shed new light on contact angle saturation. The model assumes the existence
+of a minimum (with respect to the contact angle) in the electric energy and
+accounts for a quadratic voltage dependence ~U^2 in the low-voltage limit,
+compatible with the Young-Lippmann formula, and a ~1/U^2 saturation at the
+high-voltage limit. Another prediction is the surprising possibility of a
+reversed electrowetting regime, in which the contact angle increases with
+applied voltage. By explicitly taking into account the effect of the
+counter-electrode, our model is shown to be applicable to several AC and DC
+experimental electrowetting-on-dielectric (EWOD) setups. Several features seen
+in experiments compare favorably with our results. Furthermore, the AC
+frequency dependence of EWOD agrees quantitatively with our predictions. Our
+numerical results are complemented with simple analytical expressions for the
+saturation angle in two practical limits.",1102.0791v3
+2011-08-11,Effects of MAC Approaches on Non-Monotonic Saturation with COPE - A Simple Case Study,"We construct a simple network model to provide insight into network design
+strategies. We show that the model can be used to address various approaches to
+network coding, MAC, and multi-packet reception so that their effects on
+network throughput can be evaluated. We consider several topology components
+which exhibit the same non-monotonic saturation behavior found within the Katti
+et. al. COPE experiments. We further show that fairness allocation by the MAC
+can seriously impact performance and cause this non-monotonic saturation. Using
+our model, we develop a MAC that provides monotonic saturation, higher
+saturation throughput gains and fairness among flows rather than nodes. The
+proposed model provides an estimate of the achievable gains for the cross-layer
+design of network coding, multi-packet reception, and MAC showing that
+super-additive throughput gains on the order of six times that of routing are
+possible.",1108.2514v1
+2011-12-18,Maximal determinants and saturated D-optimal designs of orders 19 and 37,"A saturated D-optimal design is a {+1,-1} square matrix of given order with
+maximal determinant. We search for saturated D-optimal designs of orders 19 and
+37, and find that known matrices due to Smith, Cohn, Orrick and Solomon are
+optimal. For order 19 we find all inequivalent saturated D-optimal designs with
+maximal determinant, 2^30 x 7^2 x 17, and confirm that the three known designs
+comprise a complete set. For order 37 we prove that the maximal determinant is
+2^39 x 3^36, and find a sample of inequivalent saturated D-optimal designs. Our
+method is an extension of that used by Orrick to resolve the previously
+smallest unknown order of 15; and by Chadjipantelis, Kounias and Moyssiadis to
+resolve orders 17 and 21. The method is a two-step computation which first
+searches for candidate Gram matrices and then attempts to decompose them. Using
+a similar method, we also find the complete spectrum of determinant values for
+{+1,-1} matrices of order 13.",1112.4160v1
+2012-03-11,Automated Synthesis of a Finite Complexity Ordering for Saturation,"We present in this paper a new procedure to saturate a set of clauses with
+respect to a well-founded ordering on ground atoms such that A < B implies
+Var(A) {\subseteq} Var(B) for every atoms A and B. This condition is satisfied
+by any atom ordering compatible with a lexicographic, recursive, or multiset
+path ordering on terms. Our saturation procedure is based on a priori ordered
+resolution and its main novelty is the on-the-fly construction of a finite
+complexity atom ordering. In contrast with the usual redundancy, we give a new
+redundancy notion and we prove that during the saturation a non-redundant
+inference by a priori ordered resolution is also an inference by a posteriori
+ordered resolution. We also prove that if a set S of clauses is saturated with
+respect to an atom ordering as described above then the problem of whether a
+clause C is entailed from S is decidable.",1203.2809v1
+2012-11-14,Multi-stable regime and intermediate solutions in a nonlinear saturable coupler,"We show, theoretically and experimentally, the existence of a multi-stable
+regime in a nonlinear saturable coupler. In spite of its simplicity, we found
+that this model shows generic and fundamental properties of extended saturable
+lattices. The study of this basic unit becomes crucial to understand
+localization mechanisms and dynamical properties of extended discrete nonlinear
+saturable systems. We theoretically predict the regions of existence of
+intermediate solutions, and experimentally confirm it by observing a
+multi-stable propagation regime in a LiNbO3 saturable coupler. This constitutes
+the first experimental evidence of the existence of these unstable
+symmetry-broken stationary solutions.",1211.3379v3
+2012-12-05,Saturating directed spaces,"Directed topology is a refinement of standard topology, where spaces may have
+non-reversible paths. It has been put forward as a candidate approach to the
+analysis of concurrent processes. Recently, a wealth of different frameworks
+for, i.e., categories of, directed spaces have been proposed. In the present
+work, starting from Grandis's notion of directed space, we propose an
+additional condition of saturation for distinguished sets of paths and show how
+it allows to rule out exotic examples without any serious collateral damage.
+Our saturation condition is local in a natural sense, and is satisfied by the
+directed interval (and the directed circle). Furthermore we show in which sense
+it is the strongest condition fulfilling these two basic requirements. Our
+saturation condition selects a full, reflective subcategory of Grandis's
+category of d-spaces, which is closed under arbitrary limits of d-spaces, has
+arbitrary colimits (obtained by saturating the corresponding colimits of
+d-spaces), and has nice cylinder and cocylinder constructions. Finally, the
+forgetful functor to plain topological spaces has both a right and a left
+adjoint.",1212.1074v1
+2013-01-24,Pricing Using a Homogeneously Saturated Equation,"A homogeneously saturated equation for the time development of the price of a
+financial asset is presented and investigated for the pricing of European call
+options using noise that is distributed as a Student's t-distribution. In the
+limit that the saturation parameter of the equation equals zero, the standard
+model of geometric motion for the price of an asset is obtained. The
+homogeneously saturated equation for the price of an asset is similar to a
+simple equation for the output of a homogeneously broadened laser. The
+homogeneously saturated equation tends to limit the range of returns and thus
+seems to be realistic.
+  Fits to linear returns obtained from the adjusted closing values for the S&P
+500 index were used to obtain best-fit parameters for Student's t-distributions
+and for normal distributions, and these fits were used to price options, and to
+compare approaches to modelling prices.
+  This work has value in understanding the pricing of assets and of European
+call options.",1301.5877v1
+2013-06-07,Saturated hydraulic conductivity determined by on ground mono-offset Ground-Penetrating Radar inside a single ring infiltrometer,"In this study we show how to use GPR data acquired along the infiltration of
+water inside a single ring infiltrometer to inverse the saturated hydraulic
+conductivity. We used Hydrus-1D to simulate the water infiltration. We
+generated water content profiles at each time step of infiltration, based on a
+particular value of the saturated hydraulic conductivity, knowing the other van
+Genuchten parameters. Water content profiles were converted to dielectric
+permittivity profiles using the Complex Refractive Index Method relation. We
+then used the GprMax suite of programs to generate radargrams and to follow the
+wetting front using arrival time of electromagnetic waves recorded by a
+Ground-Penetrating Radar (GPR). Theoretically, the 1D time convolution between
+reflectivity and GPR signal at any infiltration time step is related to the
+peak of the reflected amplitude recorded in the corresponding trace in the
+radargram. We used this relation ship to invert the saturated hydraulic
+conductivity for constant and falling head infiltrations. We present our method
+on synthetic examples and on two experiments carried out on sand soil. We
+further discuss on the uncertainties on the retrieved saturated hydraulic
+conductivity computed by our algorithm from the van Genuchten parameters.",1306.1627v1
+2013-06-14,Gluon saturation scale from the KGBJS equation,"The CCFM equation and its extended form with a quadratic term (KGBJS
+equation) are solved with fixed and running coupling constant. The solution of
+the KGBJS equation is compared to gluon densities resulting from the CCFM and
+BK equations. As the saturation scale $Q_s$ now becomes available as a function
+of the hard scale $p$ we observe that low values of $p$ impede its growth with
+$\frac 1 x$. Also, at values much larger than partons transversal momentum the
+saturation effects become independent on the hard scale what we call liberation
+of saturation scale. We also introduce the hard-scale-related saturation scale
+$P_s$ and investigate its energy dependence. We observe that the new scale as a
+function of $x$ decreases starting from the value of transversal momentum of
+gluon.",1306.3369v1
+2013-12-11,Density of Saturated Nuclear Matter at Large $N_{c}$ and Heavy Quark Mass Limits,"We exhibit the existence of stable, saturated nuclear matter in the large
+$N_{c}$ and heavy quark mass limits of QCD. In this limit, baryons (with the
+same spin flavor structure) interact at leading order in $N_{c}$ via a
+repulsive interaction due to the Pauli exclusion principle and at subleading
+order in $1/N_c$ via the exchange of glueballs. Assuming that the lightest
+glueball is a scalar, which implies that the subleading baryon interaction is
+attractive, we find that nuclear matter saturates since the subleading
+attractive interaction is longer ranged than the leading order repulsive one.
+We find that the saturated matter is in the form of a crystal with either a
+face-centered cubic or a hexagonal-close-packed symmetry with baryon densities
+of $\mathcal{O}((\, \tilde{\alpha}_{s} m_q (\ln
+(N_{c}m_{q}\Lambda_{\textrm{QCD}}^{-1}))^{-1})^3 )$. Remarkably, the leading
+order expression for the density of saturated nuclear matter is independent of
+the lighest glueball mass and scalar-glueball-baryon coupling in the extreme
+large $N_{c}$ limit or heavy quark limit (or both), which we define precisely
+in this work.",1312.3339v1
+2014-02-02,High intensity study of THz detectors based on field effect transistors,"Terahertz power dependence of the photoresponse of field effect transistors,
+operating at frequencies from 0.1 to 3 THz for incident radiation power density
+up to 100 kW/cm^2 was studied for Si metal-oxide-semiconductor field-effect
+transistors and InGaAs high electron mobility transistors. The photoresponse
+increased linearly with increasing radiation power up to kW/cm^2 range. The
+saturation of the photoresponse was observed for all investigated field effect
+transistors for intensities above several kW/cm^2. The observed signal
+saturation is explained by drain photocurrent saturation similar to saturation
+in direct currents output characteristics. The theoretical model of terahertz
+field effect transistor photoresponse at high intensity was developed. The
+model explains quantitatively experimental data both in linear and nonlinear
+(saturation) range. Our results show that dynamic range of field effect
+transistors is very high and can extend over more than six orderd of magnitudes
+of power densities (from 0.5 mW/cm^2 to 5 kW/cm^2).",1402.0259v1
+2014-07-15,Transverse Spin and Classical Gluon Fields: Combining Two Perspectives on Hadronic Structure,"In recent decades, the spin and transverse momentum of quarks and gluons were
+found to play integral roles in the structure of the nucleon. Simultaneously,
+the onset of gluon saturation in hadrons and nuclei at high energies was
+predicted to result in a new state of matter dominated by classical gluon
+fields. Understanding both of these contributions to hadronic structure is
+essential for current and future collider phenomenology. In this Dissertation,
+we study the combined effects of transverse spin and gluon saturation using the
+Glauber-Gribov-Mueller / McLerran-Venugopalan model of a heavy nucleus in the
+quasi-classical approximation. We investigate the use of a
+transversely-polarized projectile as a probe of the saturated gluon fields in
+the nucleus, finding that the transverse spin asymmetry of produced particles
+couples to the component of the gluon fields which is antisymmetric under both
+time reversal and charge conjugation. We also analyze the effects of saturation
+on the transverse spin asymmetry (Sivers function) of quarks within the wave
+function of the nucleus, finding that gluon saturation preferentially generates
+the asymmetry through the orbital angular momentum of the nucleons, together
+with nuclear shadowing.",1407.4047v1
+2014-09-18,The Saturation Number for the length of Degree Monotone Paths,"A degree monotone path in a graph $G$ is a path $P$ such that the sequence of
+degrees of the vertices in the order in which they appear on $P$ is monotonic.
+The length of the longest degree monotone path in $G$ is denoted by $mp(G)$.
+This parameter, inspired by the well-known Erdos-Szekeres theorem, has been
+studied by the authors in two earlier papers. Here we consider a saturation
+problem for the parameter $mp(G)$. We call $G$ saturated if, for every edge $e$
+added to $G$, $mp(G+e) >mp(G)$, and we define $h(n,k)$ to be the least possible
+number of edges in a saturated graph $G$ on $n$ vertices with $mp(G) < k$,
+while $mp(G+e) \geq k$ for every new edge $e$.
+  We obtain linear lower and upper bounds for $h(n,k)$, we determine exactly
+the values of $h(n,k)$ for $k=3$ and $4$, and we present constructions of
+saturated graphs.",1409.5213v1
+2014-11-10,Smoothing of Limit Linear Series of Rank One on Saturated Metrized Complexes of Algebraic Curves,"We investigate the smoothing problem of limit linear series of rank one on an
+enrichment of the notions of nodal curves and metrized complexes called
+saturated metrized complexes. We give a finitely verifiable full criterion for
+smoothability of a limit linear series of rank one on saturared metrized
+complexes, characterize the space of all such smoothings, and extend the
+criterion to metrized complexes. As applications, we prove that all limit
+linear series of rank one are smoothable on saturated metrized complexes
+corresponding to curves of compact-type, and prove an analogue for saturated
+metrized complexes of a theorem of Harris and Mumford on the characterization
+of nodal curves contained in a given gonality stratum. In addition, we give a
+full combinatorial criterion for smoothable limit linear series of rank one on
+saturated metrized complexes corresponding to nodal curves whose dual graphs
+are made of separate loops.",1411.2325v4
+2015-01-13,Classical Gluon Production Amplitude for Nucleus-Nucleus Collisions: First Saturation Correction in the Projectile,"We calculate the classical single-gluon production amplitude in
+nucleus-nucleus collisions including the first saturation correction in one of
+the nuclei (the projectile) while keeping multiple-rescattering (saturation)
+corrections to all orders in the other nucleus (the target). In our
+approximation only two nucleons interact in the projectile nucleus: the
+single-gluon production amplitude we calculate is order-g^3 and is
+leading-order in the atomic number of the projectile, while resumming all
+order-one saturation corrections in the target nucleus. Our result is the first
+step towards obtaining an analytic expression for the first projectile
+saturation correction to the gluon production cross section in nucleus-nucleus
+collisions.",1501.03106v1
+2015-03-04,Saturated simple and 2-simple topological graphs with few edges,"A simple topological graph is a topological graph in which any two edges have
+at most one common point, which is either their common endpoint or a proper
+crossing. More generally, in a k-simple topological graph, every pair of edges
+has at most k common points of this kind. We construct saturated simple and
+2-simple graphs with few edges. These are k-simple graphs in which no further
+edge can be added. We improve the previous upper bounds of Kyn\v{c}l, Pach,
+Radoi\v{c}i\'c, and T\'oth and show that there are saturated simple graphs on n
+vertices with only 7n edges and saturated 2-simple graphs on n vertices with
+14.5n edges. As a consequence, 14.5n edges is also a new upper bound for
+k-simple graphs (considering all values of k). We also construct saturated
+simple and 2-simple graphs that have some vertices with low degree.",1503.01386v2
+2015-08-12,Black phosphorus as saturable absorber for the Q-switched Er:ZBLAN fiber laser at 2.8 μm,"Black phosphorus, a newly emerged two-dimensional material, has attracted
+wide attention as novel photonic material. Here, multi-layer black phosphorus
+is successfully fabricated by liquid phase exfoliation method. By employing
+black phosphorus as saturable absorber, we demonstrate a passively Q-switched
+Er-doped ZBLAN fiber laser at the wavelength of 2.8 {\mu}m. The modulation
+depth and saturation fluence of the black phosphorus saturable absorber are
+measured to be 15% and 9 {\mu}J/cm2, respectively. The Q-switched fiber laser
+delivers a maximum average power of 485 mW with corresponding pulse energy of
+7.7 {\mu}J and pulse width of 1.18 {\mu}s at repetition rate of 63 kHz. To the
+best of our knowledge, this is the first time to demonstrate that black
+phosphorus can realize Q-switching of 2.8-{\mu}m fiber laser. Our research
+results show that black phosphorus is a promising saturable absorber for
+mid-infrared pulsed lasers.",1508.02850v1
+2015-08-19,Multilayer black phosphorus as broadband saturable absorber for pulsed lasers from 1 to 2.7 μm wavelength,"It attracts wide interest to seek universe saturable absorber covering
+wavelengths from near infrared to mid-infrared band. Multilayer black
+phosphorus, with variable direct bandgap (0.3-2 eV) depending on the layer
+number, becomes a good alternative as a universe saturable absorber for pulsed
+lasers. In this contribution, we first experimentally demonstrated broadband
+saturable absorption of multilayer black phosphorus from 1 {\mu}m to 2.7 {\mu}m
+wavelength. With the as-fabricated black phosphorus nanoflakes as saturable
+absorber, stable Q-switching operation of bulk lasers at 1.03 {\mu}m, 1.93
+{\mu}m, 2.72 {\mu}m were realized, respectively. In contrast with large-bandgap
+semiconducting transition metal dichalcogenides, such as MoS2, MoSe2,
+multilayer black phosphorus shows particular advantage at the long wavelength
+regime thanks to its narrow direct bandgap. This work will open promising
+optoelectronic applications of black phosphorus in mid-infrared spectral region
+and further demonstrate that BP may fill the gap of between zero-bandgap
+graphene and large-bandgap TMDs.",1508.04510v1
+2016-05-20,Theory of graphene saturable absorption,"Saturable absorption is a non-perturbative nonlinear optical phenomenon that
+plays a pivotal role in the generation of ultrafast light pulses. Here we show
+that this effect emerges in graphene at unprecedentedly low light intensities,
+thus opening avenues to new nonlinear physics and applications in optical
+technology. Specifically, we theoretically investigate saturable absorption in
+extended graphene by developing a non-perturbative single-particle approach,
+describing conduction-electron dynamics in the atomically-thin material using
+the two-dimensional Dirac equation for massless Dirac fermions, which is recast
+in the form of generalized Bloch equations. By solving the electron dynamics
+non-perturbatively, we account for both interband and intraband contributions
+to the intensity-dependent saturated conductivity and conclude that the former
+dominates regardless of the intrinsic doping state of the material. The results
+are in excellent agreement with atomistic quantum-mechanical simulations
+including higher-band effects. Additionally, we find that the modulation depth
+of saturable absorption in graphene can be electrically manipulated through an
+externally applied gate voltage. Our results are relevant for the development
+of graphene-based optoelectronic devices, as well as for applications in
+mode-locking and random lasers.",1605.06499v1
+2016-07-11,Saturation of the f-mode instability in neutron stars: II. Applications and results,"We present the first results on the saturation of the f-mode instability in
+neutron stars, due to nonlinear mode coupling. Emission of gravitational waves
+drives the f-mode (fundamental mode) unstable in fast-rotating, newborn neutron
+stars. The initial growth phase of the mode is followed by its saturation,
+because of energy leaking to other modes of the star. The saturation point
+determines the strain of the generated gravitational-wave signal, which can
+then be used to extract information about the neutron star equation of state.
+The parent (unstable) mode couples via parametric resonances with pairs of
+daughter modes, with the triplets' evolution exhibiting a rich variety of
+behaviors. We study both supernova- and merger-derived neutron stars, simply
+modeled as polytropes in a Newtonian context, and show that the parent may
+couple to many different daughter pairs during the star's evolution through the
+instability window, with the saturation amplitude changing by orders of
+magnitude.",1607.03059v1
+2016-07-11,Nonlinear Stabilization of High-Energy and Ultrashort Pulses in Passively Modelocked Lasers with Fast Saturable Absorption,"The two most commonly used models for passively modelocked lasers with fast
+saturable absorbers are the Haus modelocking equation (HME) and the
+cubic-quintic modelocking equation (CQME). The HME corresponds to a special
+limit of the CQME in which only a cubic nonlinearity in the fast saturable
+absorber is kept in the model. Here, we use singular perturbation theory to
+demonstrate that the CQME has a stable high-energy solution for an arbitrarily
+small but non-zero quintic contribution to the fast saturable absorber. As a
+consequence, we find that the CQME predicts the existence of stable modelocked
+pulses when the cubic nonlinearity is orders of magnitude larger than the value
+at which the HME predicts that modelocked pulses become unstable. This
+intrinsically larger stability range is consistent with experiments. Our
+results suggest a possible path to obtain high-energy and ultrashort pulses by
+fine tuning the higher-order nonlinear terms in the fast saturable absorber.",1607.03162v1
+2016-09-21,Saturating Splines and Feature Selection,"We extend the adaptive regression spline model by incorporating saturation,
+the natural requirement that a function extend as a constant outside a certain
+range. We fit saturating splines to data using a convex optimization problem
+over a space of measures, which we solve using an efficient algorithm based on
+the conditional gradient method. Unlike many existing approaches, our algorithm
+solves the original infinite-dimensional (for splines of degree at least two)
+optimization problem without pre-specified knot locations. We then adapt our
+algorithm to fit generalized additive models with saturating splines as
+coordinate functions and show that the saturation requirement allows our model
+to simultaneously perform feature selection and nonlinear function fitting.
+Finally, we briefly sketch how the method can be extended to higher order
+splines and to different requirements on the extension outside the data range.",1609.06764v3
+2016-11-02,Optimal Heavy-Traffic Queue Length Scaling in an Incompletely Saturated Switch,"We consider an input queued switch operating under the MaxWeight scheduling
+algorithm. This system is interesting to study because it is a model for
+Internet routers and data center networks. Recently, it was shown that the
+MaxWeight algorithm has optimal heavy-traffic queue length scaling when all
+ports are uniformly saturated. Here we consider the case when an arbitrary
+number of ports are saturated (which we call the incompletely saturated case),
+and each port is allowed to saturate at a different rate. We use a recently
+developed drift technique to show that the heavy-traffic queue length under the
+MaxWeight scheduling algorithm has optimal scaling with respect to the switch
+size even in these cases.",1611.00745v1
+2017-06-27,Effect of saturable nonlinearity on cw stability in passively mode-locked lasers with fast saturable absorbers,"The self-starting dynamics of a model for passively mode-locked lasers with
+saturable absorber, in which the optical amplifier has a saturable
+nonlinearity, is examined. The basic assumption is that the laser will operate
+in the mode-locked regime when the continuous-wave regime becomes unstable.
+Within the framework of the modulational-instability analysis, a global map for
+the laser self-starting criteria is constructed. According to this map, the
+saturable nonlinearity enhances the input-field intensity required for laser
+self-starting. Analytical expression of the zero modulation-frequency regime of
+this threshold input field is derived, which turns out to be valid in the
+normal as well as in the anomalous dispersion regime, where evidence of
+self-starting is also given.",1706.09028v1
+2017-06-30,Saturation of entropy production in quantum many-body systems,"Bridging the second law of thermodynamics and microscopic reversible dynamics
+has been a longstanding problem in statistical physics. We here address this
+problem on the basis of quantum many-body physics, and discuss how the entropy
+production saturates in isolated quantum systems under unitary dynamics. First,
+we rigorously prove the saturation of the entropy production in the long time
+regime, where a total system can be in a pure state. Second, we discuss the
+non-negativity of the entropy production at saturation, implying the second law
+of thermodynamics. This is based on the eigenstate thermalization hypothesis
+(ETH), which states that even a single energy eigenstate is thermal. We also
+numerically demonstrate that the entropy production saturates at a non-negative
+value even when the initial state of a heat bath is a single energy eigenstate.
+Our results reveal fundamental properties of the entropy production in isolated
+quantum systems at late times.",1706.10112v2
+2017-08-12,Noisy Softmax: Improving the Generalization Ability of DCNN via Postponing the Early Softmax Saturation,"Over the past few years, softmax and SGD have become a commonly used
+component and the default training strategy in CNN frameworks, respectively.
+However, when optimizing CNNs with SGD, the saturation behavior behind softmax
+always gives us an illusion of training well and then is omitted. In this
+paper, we first emphasize that the early saturation behavior of softmax will
+impede the exploration of SGD, which sometimes is a reason for model converging
+at a bad local-minima, then propose Noisy Softmax to mitigating this early
+saturation issue by injecting annealed noise in softmax during each iteration.
+This operation based on noise injection aims at postponing the early saturation
+and further bringing continuous gradients propagation so as to significantly
+encourage SGD solver to be more exploratory and help to find a better
+local-minima. This paper empirically verifies the superiority of the early
+softmax desaturation, and our method indeed improves the generalization ability
+of CNN model by regularization. We experimentally find that this early
+desaturation helps optimization in many tasks, yielding state-of-the-art or
+competitive results on several popular benchmark datasets.",1708.03769v1
+2017-10-05,Current Saturation in Nonmetallic Field Emitters,"It has been known for a long time that traditional semiconductor (e.g.
+intrinsic and doped Si and Ge or binary SiC and GaN) field emitters
+significantly deviate from Fowler-Nordheim (FN) law and saturate when a large
+current, on the order of microamperes or more, is attempted to be drawn from
+them. Many experiments established that the field emission current from
+carbonic materials, such as carbon nanotubes, amorphous carbon and
+polycrystalline diamond films, also deviate from FN law and saturate. These
+findings suggested that the saturation and departure from FN law is a broad and
+general phenomenon that applies to the class of nonmetallic field emitters. In
+this letter, we report a universal formula that describes the current
+saturation effect in nonmetallic field emitters. The formula accounts for
+material's bulk properties and field emitter geometry.",1710.03692v2
+2017-12-01,On Edge-Colored Saturation Problems,"Let $\mathcal{C}$ be a family of edge-colored graphs. A $t$-edge colored
+graph $G$ is $(\mathcal{C}, t)$-saturated if $G$ does not contain any graph in
+$\mathcal{C}$ but the addition of any edge in any color in $[t]$ creates a copy
+of some graph in $\mathcal{C}$. Similarly to classical saturation functions,
+define $\mathrm{sat}_t(n, \mathcal{C})$ to be the minimum number of edges in a
+$(\mathcal{C},t)$ saturated graph. Let $\mathcal{C}_r(H)$ be the family
+consisting of every edge-colored copy of $H$ which uses exactly $r$ colors.
+  In this paper we consider a variety of colored saturation problems. We
+determine the order of magnitude for $\mathrm{sat}_t(n, \mathcal{C}_r(K_k))$
+for all $r$, showing a sharp change in behavior when $r\geq \binom{k-1}{2}+2$.
+A particular case of this theorem proves a conjecture of Barrus, Ferrara,
+Vandenbussche, and Wenger. We determine $\mathrm{sat}_t(n, \mathcal{C}_2(K_3))$
+exactly and determine the extremal graphs. Additionally, we document some
+interesting irregularities in the colored saturation function.",1712.00163v1
+2018-03-22,Precise algorithm to generate random sequential adsorption of hard polygons at saturation,"Random sequential adsorption (RSA) is a time-dependent packing process, in
+which particles of certain shapes are randomly and sequentially placed into an
+empty space without overlap. In the infinite-time limit, the density approaches
+a ""saturation"" limit. Although this limit has attracted particular research
+interest, the majority of past studies could only probe this limit by
+extrapolation. We have previously found an algorithm to reach this limit using
+finite computational time for spherical particles, and could thus determine the
+saturation density of spheres with high accuracy. In this paper, we generalize
+this algorithm to generate saturated RSA packings of two-dimensional polygons.
+We also calculate the saturation density for regular polygons of three to ten
+sides, and obtain results that are consistent with previous,
+extrapolation-based studies.",1803.08348v2
+2018-06-19,Optimal measurements for quantum multiparameter estimation with general states,"We generalize the approach by Braunstein and Caves [Phys. Rev. Lett. 72, 3439
+(1994)] to quantum multi-parameter estimation with general states. We derive a
+matrix bound of the classical Fisher information matrix due to each measurement
+operator. The saturation of all these bounds results in the saturation of the
+matrix Helstrom Cram\'er-Rao bound. Remarkably, the saturation of the matrix
+bound is equivalent to the saturation of the scalar bound with respect to any
+given positive definite weight matrix. Necessary and sufficient conditions are
+obtained for the optimal measurements that give rise to the Helstrom
+Cram\'er-Rao bound associated with a general quantum state. To saturate the
+Helstrom bound with separable measurements or collective measurement entangling
+only a small number of identical states, we find it is necessary for the
+symmetric logarithmic derivatives to commute on the support of the state. As an
+important application of our results, we construct several local optimal
+measurements for the problem of estimating the three-dimensional separation of
+two incoherent optical point sources.",1806.07337v3
+2018-06-28,Band-edge quasiparticles from electron phonon coupling and resistivity saturation,"We address the problem of resistivity saturation observed in materials such
+as the A-15 compounds. To do so, we calculate the resistivity for the
+Hubbard-Holstein model in infinite spatial dimensions to second order in
+on-site repulsion $U\leq D$ and to first order in (dimensionless)
+electron-phonon coupling strength $\lambda\leq0.5$, where $D$ is the
+half-bandwidth. We identify a unique mechanism to obtain two parallel quantum
+conducting channels: low-energy and band-edge high-energy quasi-particles. We
+identify the source of the hitherto unremarked high-energy quasi-particles as a
+positive slope in the frequency-dependence of the real part of the electron
+self-energy. In the presence of phonons, the self-energy grows linearly with
+the temperature at high-$T$, causing the resistivity to saturate. As $U$ is
+increased, the saturation temperature is pushed to higher values, offering a
+mechanism by which electron-correlations destroy saturation.",1806.11227v2
+2018-09-17,Saturating the quantum Cramér-Rao bound using LOCC,"The quantum Cram\'er-Rao bound (QCRB) provides an ultimate precision limit
+allowed by quantum mechanics in parameter estimation. Given any quantum state
+dependent on a single parameter, there is always a positive-operator valued
+measurement (POVM) saturating the QCRB. However, the QCRB-saturating POVM
+cannot always be implemented efficiently, especially in multipartite systems.
+In this paper, we show that the POVM based on local operations and classical
+communication (LOCC) is QCRB-saturating for arbitrary pure states or rank-two
+mixed states with varying probability distributions over fixed eigenbasis.
+Local measurements without classical communication, however, is not
+QCRB-saturating in general.",1809.06017v3
+2018-10-30,A note on saturation for Berge-G hypergraphs,"For a graph G, a hypergraph H is called Berge-G if there is a hypergraph H',
+isomorphic to H, containing all vertices of G, so that e is contained in f(e)
+for each edge e of G, where f is a bijection between E(G) and E(H'). The set of
+all Berge-G hypergraphs is denoted B(G). A hypergraph H is called Berge-G
+saturated if it does not contain any subhypergraph from B(G), but adding any
+new hyperedge of size at least 2 to H creates such a subhypergraph. Each
+Berge-G saturated hypergraph has at least |E(G)|-1 hyperedges. We show that for
+each graph G that is not a certain star and for any n at least |V(G)|, there is
+a Berge-G saturated hypergraph on n vertices and exactly |E(G)|-1 hyperedges.
+This solves a problem of finding a saturated hypergraph on n vertices with the
+smallest number of edges exactly.",1810.12734v1
+2019-02-21,Low $x$ physics as an infinite twist (G)TMD framework: unravelling the origins of saturation,"We show how the formulations of low $x$ physics involving Wilson line
+operators can be fully rewritten into an infinite twist TMD or GTMD framework,
+respectively for inclusive and exclusive observables. This leads to a perfect
+match between low $x$ physics and moderate $x$ formulations of QCD in terms of
+GTMDs, TMDs, GPDs or PDFs. We derive the BFKL limit as a kinematic limit and
+argue that beyond the Wandzura-Wilczek approximation, 3-body and 4-body
+unintegrated PDFs should be taken into account even in this regime. Finally, we
+analyze how saturation should be understood as three distinct effects:
+saturation through non-linearities in the evolution equations at small $x$,
+saturation through multiple interactions with slow gluons as TMD gauge links,
+and saturation as the enhancement of genuine twist corrections.",1902.07930v1
+2019-03-17,System Level Synthesis with State and Input Constraints,"This paper addresses the problem of designing distributed controllers with
+state and input constraints in the System Level Synthesis (SLS) framework.
+Using robust optimization, we show how state and actuation constraints can be
+incorporated into the SLS structure. Moreover, we show that the dual variable
+associated with the constraint has the same sparsity pattern as the SLS
+parametrization, and therefore the computation distributes using a simple
+primal-dual algorithm. We provide a stability analysis for SLS design with
+input saturation under the Internal Model Control (IMC) framework. We show that
+the closed-loop system with saturation is stable if the controller has a gain
+less than one. In addition, a saturation compensation scheme that incorporates
+the saturation information is proposed which improves the naive SLS design
+under saturation.",1903.07174v3
+2019-03-26,Bottom stresses of static packing of granular chains,"We experimentally measure the static stress at the bottom of a granular
+chains column with a precise and reproducible method. The relation, between the
+filling mass and the apparent mass converted from the bottom stress, is
+investigated on various chain lengths. Our measurements reconfirm that the
+scaling behavior of the stress saturation curves is in accord with the
+theoretical expectation of the Janssen model. Additionally, the saturation mass
+is displayed as a nonmonotonic function of the chain length, where a
+distinguishing transition of the saturation mass is found at the persistence
+length of the granular chain. We repeat the measurement with another measuring
+methodology and a silo with different size, respectively, the position of the
+peak maintains robust. In order to understand the transition of the saturation
+mass, the friction coefficient and the volume fraction of granular chains are
+also measured, from which Janssen parameter can be calculated. Finally, we
+preliminarily measure the bottom stress for two distinct packing structures of
+long chains, find the effect of the entanglements on the bottom stress, and
+argue that the entanglements might be responsible for the transition of the
+saturation mass.",1903.10664v1
+2019-09-12,Ecological communities from random generalised Lotka-Volterra dynamics with non-linear feedback,"We investigate the outcome of generalised Lotka-Volterra dynamics of
+ecological communities with random interaction coefficients and non-linear
+feedback. We show in simulations that the saturation of non-linear feedback
+stabilises the dynamics. This is confirmed in an analytical
+generating-functional approach to generalised Lotka-Volterra equations with
+piecewise linear saturating response. For such systems we are able to derive
+self-consistent relations governing the stable fixed-point phase, and to carry
+out a linear stability analysis to predict the onset of unstable behaviour. We
+investigate in detail the combined effects of the mean, variance and
+co-variance of the random interaction coefficients, and the saturation value of
+the non-linear response. We find that stability and diversity increases with
+the introduction of non-linear feedback, where decreasing the saturation value
+has a similar effect to decreasing the co-variance. We also find co-operation
+to no longer have a detrimental effect on stability with non-linear feedback,
+and the order parameters mean abundance and diversity to be less dependent on
+the symmetry of interactions with stronger saturation.",1909.05802v2
+2019-10-19,A Novel Scheme of Digital Instantaneous Automatic Gain Control (DIAGC) for Pulse Radars,"Several schemes for gain control are used for preventing saturation of
+receiver, and overloading of data processor, tracker or display in pulse
+radars. The use of digital processing techniques open the door to a variety of
+digital automatic gain control schemes for analyzing digitized return signals
+and controlling receiver gain only at saturating clutter zones without
+affecting the detection at other zones. In this paper, we present a novel
+scheme of Digital Instantaneous Automatic Gain Control (DIAGC) which is based
+on storing digitally the dwell based clutter returns and deriving the gain
+control. The returns corresponding to the first two PRTs in a dwell are used to
+analyze the presence of saturating clutter zones and the depth of saturation.
+Third PRT onwards proper gain control is applied at the IF stage to prevent
+saturation of the following stages. FPGA based scheme is used for digital data
+processing, storing, threshold calculation and gain control generation. The
+effect of DIAGC on pulse compression is also addressed in this paper.",1910.08861v1
+2019-11-28,Saturated random packing built of arbitrary polygons under random sequential adsorption protocol,"Random packings and their properties are a popular and active field of
+research. Numerical algorithms that can efficiently generate them are useful
+tools in their study. This paper focuses on random packings produced according
+to the random sequential adsorption (RSA) protocol. Developing the idea
+presented in [G. Zhang, Phys. Rev. E {\bf 97}, 043311 (2018)], where saturated
+random packings built of regular polygons were studied, we create an algorithm
+that generates strictly saturated packings built of any polygons. Then, the
+algorithm was used to determine the packing fractions for arbitrary triangles.
+The highest mean packing density, $0.552814 \pm 0.000063$, was observed for
+triangles of side lengths $0.63:1:1$. Additionally, microstructural properties
+of such packings, kinetics of their growth as well as distributions of
+saturated packing fractions and the number of RSA iterations needed to reach
+saturation were analyzed.",1911.12626v1
+2020-01-09,Black holes often saturate entanglement entropy the fastest,"There is a simple bound on how fast the entanglement entropy of a subregion
+of a many-body quantum system can saturate in a quench: $t_\text{sat}\geq
+R/v_B$, where $t_\text{sat}$ is the saturation time, $R$ the radius of the
+largest inscribed sphere, and $v_B$ the butterfly velocity characterizing
+operator growth. By combining analytic and numerical approaches, we show that
+in systems with a holographic dual, the saturation time is equal to this lower
+bound for a variety of differently shaped entangling surfaces, implying that
+the dual black holes saturate the entanglement entropy as fast as possible.
+This finding adds to the growing list of tasks that black holes are the fastest
+at. We furthermore analyze the complete time evolution of entanglement entropy
+for large regions with a variety of shapes, yielding more detailed information
+about the process of thermalization in these systems.",2001.03172v3
+2020-11-12,Hamiltonian Dynamics of Saturated Elongation in Amyloid Fiber Formation,"Elongation is a fundament process in amyloid fiber growth, which is normally
+characterized by a linear relationship between the fiber elongation rate and
+the monomer concentration. However, in high concentration regions, a sub-linear
+dependence was often observed, which could be explained by a universal
+saturation mechanism. In this paper, we modeled the saturated elongation
+process through a Michaelis-Menten like mechanism, which is constituted by two
+sub-steps -- unspecific association and dissociation of a monomer with the
+fibril end, and subsequent conformational change of the associated monomer to
+fit itself to the fibrillar structure. Typical saturation concentrations were
+found to be $7-70\mu M$ for A$\beta$40, $\alpha$-synuclein and etc.
+Furthermore, by using a novel Hamiltonian formulation, analytical solutions
+valid for both weak and strong saturated conditions were constructed and
+applied to the fibrillation kinetics of $\alpha$-synuclein and silk fibroin.",2011.06222v1
+2021-07-06,Saturation-Aware Model Predictive Energy Management for Droop-Controlled Islanded Microgrids,"In this paper, we propose a minimax model predictive control (MPC)-based
+energy management system that is robust with respect to uncertainties in
+renewable infeed and load. The MPC formulation includes a model of low-level
+droop control with saturation at the power and energy limits of the units.
+Robust MPC-based energy management systems tend to under-utilize the renewable
+energy sources to guarantee safe operation. In order to mitigate this effect,
+we further consider droop control of renewable energy sources. For a microgrid
+with droop-controlled units, we show that enhancing droop feedback with
+saturation enlarges the space of feasible control actions. However, the
+resulting controller requires to solve a mixed-integer problem with additional
+variables and equations representing saturation. We derive a computationally
+tractable formulation for this problem. Furthermore, we investigate the
+performance gained by using droop with saturation, renewable droop and
+combination of both in a case study.",2107.02719v1
+2021-07-16,Maximising Precision in Saturation-Limited Absorption Measurements,"Quantum fluctuations in the intensity of an optical probe is noise which
+limits measurement precision in absorption spectroscopy. Increased probe power
+can offer greater precision, however, this strategy is often constrained by
+sample saturation. Here, we analyse measurement precision for a generalised
+absorption model in which we account for saturation and explore its effect on
+both classical and quantum probe performance. We present a classical
+probe-sample optimisation strategy to maximise precision and find that optimal
+probe powers always fall within the saturation regime. We apply our
+optimisation strategy to two examples, high-precision Doppler broadened
+thermometry and an absorption spectroscopy measurement of Chlorophyll A. We
+derive a limit on the maximum precision gained from using a non-classical probe
+and find a strategy capable of saturating this bound. We evaluate
+amplitude-squeezed light as a viable experimental probe state and find it
+capable of providing precision that reaches to within > 85% of the ultimate
+quantum limit with currently available technology.",2107.07888v1
+2021-09-27,Mono-elemental saturable absorber in mode-locked fiber laser: A review,"Two-dimensional mono-elemental material is an excellent saturable absorber
+candidate with low saturation intensity, large modulation depth, high
+nonlinearities, and fast recovery time of excited carriers. Typically, these
+mono-elemental material with two-dimensional structure possesses tunable
+bandgap from metallic to semiconducting according to different number of
+layers. The successful application of these materials as the saturable absorber
+has exploited the development of mode-locked fiber lasers. Therefore, this
+review is intended to provide an up-to-date information to the development of
+mono-elemental saturable absorber for the advances in mode-locked fiber laser,
+with emphasis on their material properties, synthesis process and material
+characterization. Meanwhile, issues and challenges of the review research topic
+will be highlighted and addressed with several concrete recommendations.",2109.13024v1
+2021-10-25,Saturated $2$-planar drawings with few edges,"A drawing of a graph is $k$-plane if every edge contains at most $k$
+crossings. A $k$-plane drawing is saturated if we cannot add any edge so that
+the drawing remains $k$-plane. It is well-known that saturated $0$-plane
+drawings, that is, maximal plane graphs, of $n$ vertices have exactly $3n-6$
+edges. For $k>0$, the number of edges of saturated $n$-vertex $k$-plane graphs
+can take many different values. In this note, we establish some bounds on the
+minimum number of edges of saturated $2$-plane graphs under different
+conditions. If two edges can cross at most once, then such a graph has at least
+$n-1$ edges. If two edges can cross many times, then we show the tight bound of
+$\lfloor2n/3\rfloor$ for the number of edges.",2110.12781v3
+2021-12-22,An Alternate Policy Gradient Estimator for Softmax Policies,"Policy gradient (PG) estimators are ineffective in dealing with softmax
+policies that are sub-optimally saturated, which refers to the situation when
+the policy concentrates its probability mass on sub-optimal actions.
+Sub-optimal policy saturation may arise from bad policy initialization or
+sudden changes in the environment that occur after the policy has already
+converged. Current softmax PG estimators require a large number of updates to
+overcome policy saturation, which causes low sample efficiency and poor
+adaptability to new situations. To mitigate this problem, we propose a novel PG
+estimator for softmax policies that utilizes the bias in the critic estimate
+and the noise present in the reward signal to escape the saturated regions of
+the policy parameter space. Our theoretical analysis and experiments, conducted
+on bandits and various reinforcement learning environments, show that this new
+estimator is significantly more robust to policy saturation.",2112.11622v2
+2021-12-24,A semi-bijective algorithm for saturated extended 2-regular simple stacks,"Combinatorics of biopolymer structures, especially enumeration of various RNA
+secondary structures and protein contact maps, is of significant interest for
+communities of both combinatorics and computational biology. However, most of
+the previous combinatorial enumeration results for these structures are
+presented in terms of generating functions, and few are explicit formulas. This
+paper is mainly concerned with finding explicit enumeration formulas for a
+particular class of biologically relevant structures, say, saturated 2-regular
+simple stacks, whose configuration is related to protein folds in the 2D
+honeycomb lattice. We establish a semi-bijective algorithm that converts
+saturated 2-regular simple stacks into forests of small trees, which produces a
+uniform formula for saturated extended 2-regular simple stacks with any of the
+six primary component types. Summarizing the six different primary component
+types, we obtain a bivariate explicit formula for saturated extended 2-regular
+simple stacks with $n$ vertices and $k$ arcs. As consequences, the uniform
+formula can be reduced to Clote's results on $k$-saturated 2-regular simple
+stacks and the optimal 2-regular simple stacks, and Guo et al.'s result on the
+optimal extended 2-regular simple stacks.",2112.13087v2
+2022-01-25,Exclusive processes in $ep$ collisions at the EIC and LHeC: A closer look on the predictions of saturation models,"The exclusive production of vector mesons and photons in $ep$ collisions is
+investigated considering three phenomenological saturation models based on
+distinct assumptions for the treatment of the dipole - hadron scattering
+amplitude. The latest high precision HERA data for the reduced and vector meson
+cross sections are used to update the saturation model proposed by Marquet -
+Peschanski - Soyez (MPS), which predicts that the saturation model is dependent
+of the squared momentum transfer $t$. The MPS predictions for the photon
+virtuality, energy and $t$ - dependencies of the exclusive $\rho$, $J/\Psi$ and
+DVCS cross sections are presented and a detailed comparison with the results
+derived using the impact parameter saturation models is performed. Our results
+indicate that a future experimental analysis of the $t$ - distribution
+$d\sigma/dt$ for exclusive processes in the kinematical range that will covered
+by the EIC and LHeC, considering the distinct photon polarizations and large
+values of $t$, will be able to discriminate between the distinct approaches for
+the QCD dynamics at high energies.",2201.10499v1
+2022-03-17,Neutron star mass formula with nuclear saturation parameters,"We derive the empirical formulas for the neutron star mass and gravitational
+redshift as a function of the central density and specific combination of the
+nuclear saturation parameters, which are applicable to the stellar models
+constructed with the central density up to threefold nuclear saturation
+density. Combining the both empirical formulas, one also estimates the neutron
+star radius. In practice, we find that the neutron star mass (radius) can be
+estimated within $\sim 10\%$ (a few percent) accuracy by comparing the mass and
+radius evaluated with our empirical formulas to those determined with the
+specific equation of state. Since our empirical formulas directly connect the
+neutron star mass and radius to the nuclear saturation parameters, one can
+discuss the neutron star properties with the specific values of nuclear
+saturation parameters constrained via nuclear experiments.",2203.09004v1
+2022-06-08,Wavelike nature of the vertical shear instability in global protoplanetary disks,"The vertical shear instability (VSI) is a robust phenomenon in irradiated
+protoplanetary disks (PPDs). The majority of previous numerical simulations
+have focused on the turbulent properties of its saturated state. However, the
+saturation of the VSI manifests as large-scale coherent radially travelling
+inertial waves. In this paper, we study inertial-wave-disk interactions and
+their impact on VSI saturation. Inertial-wave linear theory is developed and
+applied to a representative global 2D simulation using the Athena++ code. It is
+found that the VSI saturates by separating the disk into several radial wave
+zones roughly demarcated by corotation resonances (turning points); this
+structure also manifests in modest radial variations in the vertical turbulence
+strength. Future numerical work should employ large radial domains to
+accommodate this radial structure of the VSI, while concurrently adopting
+sufficiently fine resolutions to resolve the parametric instability that
+attacks the saturated VSI inertial waves.",2206.03840v2
+2022-08-10,Saturation-based Boolean conjunctive query answering and rewriting for the guarded quantification fragments,"Query answering is an important problem in AI, database and knowledge
+representation. In this paper, we develop saturation-based Boolean conjunctive
+query answering and rewriting procedures for the guarded, the loosely guarded
+and the clique-guarded fragments. Our query answering procedure improves
+existing resolution-based decision procedures for the guarded and the loosely
+guarded fragments and this procedure solves Boolean conjunctive query answering
+problems for the guarded, the loosely guarded and the clique-guarded fragments.
+Based on this query answering procedure, we also introduce a novel
+saturation-based query rewriting procedure for these guarded fragments. Unlike
+mainstream query answering and rewriting methods, our procedures derive a
+compact and reusable saturation, namely a closure of formulas, to handle the
+challenge of querying for distributed datasets. This paper lays the theoretical
+foundations for the first automated deduction decision procedures for Boolean
+conjunctive query answering and the first saturation-based Boolean conjunctive
+query rewriting in the guarded, the loosely guarded and the clique-guarded
+fragments.",2208.05365v2
+2022-08-19,The saturation of exponents and the asymptotic fourth state of turbulence,"A recent discovery about the inertial range of homogeneous and isotropic
+turbulence is the saturation of the scaling exponents $\zeta_n$ for large $n$,
+defined via structure functions of order $n$ as $S_{n}(r)=\overline{(\delta_r
+u)^{n}}=A(n)r^{\zeta_{n}}$. We focus on longitudinal structure functions for
+$\delta_r u$ between two positions that are $r$ apart in the same direction. In
+a previous paper (Phys.\ Rev.\ Fluids 6, 104604, 2021), we developed a theory
+for $\zeta_n$, which agrees with measurements for all $n$ for which reliable
+data are available, and shows saturation for large $n$. Here, we derive
+expressions for the probability density functions of $\delta_r u$ for four
+different states of turbulence, including the asymptotic fourth state
+corresponding to the saturation of exponents for large $n$. This saturation
+means that the scale separation is violated in favor of a strongly-coupled
+quasi-ordered flow structures, which take the form of long and thin (worm-like)
+structures of length $L$ and thickness $l=O(L/Re)$.",2208.09561v1
+2022-10-17,"Decoherence, Entanglement Negativity and Circuit Complexity for Open Quantum System","In this paper, we compare the saturation time scales for complexity, linear
+entropy and entanglement negativity for two open quantum systems. Our first
+model is a coupled harmonic oscillator, where we treat one of the oscillators
+as the bath. The second one is a type of Caldeira Leggett model, where we
+consider a one-dimensional free scalar field as the bath. Using these open
+quantum systems, we discovered that both the complexity of purification and the
+complexity from operator state mapping is always saturated for a completely
+mixed state. More explicitly, the saturation time scale for both types of
+complexity is smaller than the saturation time scale for linear entropy. On top
+of this, we found that the saturation time scale for linear entropy and
+entanglement negativity is of the same order for the Caldeira Leggett model.",2210.09268v1
+2022-11-20,The saturation number of monomial ideals,"Let $S=\mathbb{K}[x_1,\ldots, x_n]$ be the polynomial ring over a field
+$\mathbb{K}$ and $\mathfrak{m}= (x_1, \ldots, x_n)$ be the irredundant maximal
+ideal of $S$. For an ideal $I \subset S$, let $\mathrm{sat}(I)$ be the minimum
+number $k$ for which $I \colon \mathfrak{m}^k = I \colon \mathfrak{m}^{k+1}$.
+In this paper, we compute the saturation number of irreducible monomial ideals
+and their powers. We apply this result to find the saturation number of the
+ordinary powers and symbolic powers of some families of monomial ideals in
+terms of the saturation number of irreducible components appearing in an
+irreducible decomposition of these ideals. Moreover, we give an explicit
+formula for the saturation number of monomial ideals in two variables.",2211.10982v2
+2023-03-11,Rate-Distortion Optimization With Alternative References For UGC Video Compression,"User generated content (UGC) refers to videos that are uploaded by users and
+shared over the Internet. UGC may have low quality due to noise and previous
+compression. When re-encoding UGC for streaming or downloading, a traditional
+video coding pipeline will perform rate-distortion (RD) optimization to choose
+coding parameters. However, in the UGC video coding case, since the input is
+not pristine, quality ``saturation'' (or even degradation) can be observed,
+i.e., increased bitrate only leads to improved representation of coding
+artifacts and noise present in the UGC input. In this paper, we study the
+saturation problem in UGC compression, where the goal is to identify and avoid
+during encoding, the coding parameters and rates that lead to quality
+saturation. We proposed a geometric criterion for saturation detection that
+works with rate-distortion optimization, and only requires a few frames from
+the UGC video. In addition, we show how to combine the proposed saturation
+detection method with existing video coding systems that implement
+rate-distortion optimization for efficient compression of UGC videos.",2303.06254v1
+2023-05-01,Inference of relative permeability curves in reservoir rocks with ensemble Kalman method,"Multiphase flows through reservoir rocks are a universal and complex
+phenomenon. Relative permeability is one of the primary determinants in
+reservoir performance calculations. Accurate estimation of the relative
+permeability is crucial for reservoir management and future production. In this
+paper, we propose inferring relative permeability curves from sparse saturation
+data with an ensemble Kalman method. We represent these curves through a series
+of positive increments of relative permeability at specified saturation values,
+which guarantees monotonicity within, and boundedness between, 0 and 1. The
+proposed method is validated by the inference performances in two synthetic
+benchmarks designed by SPE and a field-scale model developed by Equinor that
+includes certain real-field features. The results indicate that the relative
+permeability curves can be accurately estimated within the saturation intervals
+having available observations and appropriately extrapolated to the remaining
+saturations by virtue of the embedded constraints. The predicted well responses
+are comparable to the ground truths, even though they are not included as the
+observation. The study demonstrates the feasibility of using ensemble Kalman
+method to infer relative permeability curves from saturation data, which can
+aid in the predictions of multiphase flow and reservoir production.",2305.01029v1
+2023-07-10,Saturation and multifractality of Lagrangian and Eulerian scaling exponents in 3D isotropic turbulence,"Inertial range scaling exponents for both Lagrangian and Eulerian structure
+functions are obtained from direct numerical simulations of isotropic
+turbulence in triply periodic domains at Taylor-scale Reynolds number up to
+1300. We reaffirm that transverse Eulerian scaling exponents saturate at
+$\approx 2.1$ for moment orders $p \ge 10$, significantly differing from the
+longitudinal exponents (which are predicted to saturate at $\approx 7.3$ for $p
+\ge 30$ from a recent theory). The Lagrangian scaling exponents likewise
+saturate at $\approx 2$ for $p \ge 8$. The saturation of Lagrangian exponents
+and transverse Eulerian exponents is related by the same multifractal spectrum
+by utilizing the well known frozen hypothesis to relate spatial and temporal
+scales. Furthermore, this spectrum is different from the known spectra for
+Eulerian longitudinal exponents, suggesting that that Lagrangian intermittency
+is characterized solely by transverse Eulerian intermittency. We discuss
+possible implication of this outlook when extending multifractal predictions to
+the dissipation range, especially for Lagrangian acceleration.",2307.04846v2
+2023-11-28,On the saturation spectrum of the unions of disjoint cycles,"Let $G$ be a graph and $\mathcal{H}$ be a family of graphs. We say $G$ is
+$\mathcal{H}$-saturated if $G$ does not contain a copy of $H$ with
+$H\in\mathcal{H}$, but the addition of any edge $e\notin E(G)$ creates at least
+one copy of some $H\in\mathcal{H}$ within $G+e$. The saturation number of
+$\mathcal{H}$ is the minimum size of an $\mathcal{H}$-saturated graph on $n$
+vertices, and the saturation spectrum of $\mathcal{H}$ is the set of all
+possible sizes of an $\mathcal{H}$-saturated graph on $n$ vertices. Let
+$k\mathcal{C}_{\ge 3}$ be the family of the unions of $k$ vertex-disjoint
+cycles. In this note, we completely determine the saturation number and the
+saturation spectrum of $k\mathcal{C}_{\ge 3}$ for $k=2$ and give some results
+for $k\ge 3$.",2311.16899v1
+2023-12-15,Intersection-saturated groups without free subgroups,"A group $G$ is said to be intersection-saturated if for every strictly
+positive integer $n$ and every map $c\colon \mathcal{P}(\{1,\dots,
+n\})\setminus \emptyset \rightarrow \{0,1\}$, one can find subgroups
+$H_1,\dots, H_n\leq G$ such that for every non-empty subset $I\subseteq
+\{1,\dots, n\}$, the intersection $\bigcap_{i\in I}H_i$ is finitely generated
+if and only if $c(I)=0$. We obtain a new criterion for a group to be
+intersection-saturated based on the existence of arbitrarily high direct powers
+of a subgroup admitting an automorphism with a non-finitely generated set of
+fixed points. We use this criterion to find new examples of
+intersection-saturated groups, including Thompson's groups and the Grigorchuk
+group. In particular, this proves the existence of finitely presented
+intersection-saturated groups without non-abelian free subgroups, thus
+answering a question of Delgado, Roy and Ventura.",2312.09954v2
+2023-12-25,Saturation of nuclear matter in the relativistic Brueckner Hatree-Fock approach with a leading order covariant chiral nuclear force,"Nuclear saturation is a crucial feature in nuclear physics that plays a
+fundamental role in understanding various nuclear phenomena, ranging from
+properties of finite nuclei to those of neutron stars. However, a proper
+description of nuclear saturation is highly nontrivial in modern
+nonrelativistic~\textit{ab initio}~studies because of the elusive three-body
+forces. In this letter, we calculate the equation of state for nuclear matter
+in the relativistic Brueckner-Hartree-Fock framework with the leading order
+covariant chiral nuclear force. We show that a simultaneous description of the
+nucleon-nucleon scattering data and the saturation of the symmetric nuclear
+matter can be achieved. In this regard, the relativistic effects nicely explain
+the saturation of nuclear matter. As a result, the present study provides a new
+perspective on one of the most salient features in nuclear physics.",2312.15672v1
+2024-02-05,Declipping and the recovery of vectors from saturated measurements,"A frame $(x_j)_{j\in J}$ for a Hilbert space $H$ allows for a linear and
+stable reconstruction of any vector $x\in H$ from the linear measurements
+$(\langle x,x_j\rangle)_{j\in J}$. However, there are many situations where
+some information in the frame coefficients is lost. In applications where one
+is using sensors with a fixed dynamic range, any measurement above that range
+is registered as the maximum, and any measurement below that range is
+registered as the minimum. Depending on the context, recovering a vector from
+such measurements is called either declipping or saturation recovery. We
+initiate a frame theoretic approach to saturation recovery in a similar way to
+what [BCE06] did for phase retrieval. We characterize when saturation recovery
+is possible, show optimal frames for use with saturation recovery correspond to
+minimal multi-fold packings in projective space, and prove that the classical
+frame algorithm may be adapted to this non-linear problem to provide a
+reconstruction algorithm.",2402.03237v1
+2024-02-17,A lower bound on the saturation number and a strengthening for triangle-free graphs,"The saturation number $\operatorname{sat}(n, H)$ of a graph $H$ and positive
+integer $n$ is the minimum size of an $n$-vertex graph which does not contain a
+subgraph isomorphic to $H$ but to which the addition of any edge creates such a
+subgraph. Erd\H{o}s, Hajnal, and Moon first studied saturation numbers of
+complete graphs, and Cameron and Puleo introduced a general lower bound on
+$\operatorname{sat}(n,H)$. In this paper, we present another lower bound on
+$\operatorname{sat}(n, H)$ with a strengthening when $H$ is triangle-free.
+Demonstrating its effectiveness, we determine the saturation numbers of
+diameter-$3$ trees up to an additive constant; these are double stars $S_{s,t}$
+on $s + t$ vertices whose centers have degrees $s$ and $t$. Faudree, Faudree,
+Gould, and Jacobson determined that $\operatorname{sat}(n, S_{t,t}) = (t-1)n/2
++ O(1)$. We show that $\operatorname{sat}(n,S_{s,t}) = (st+s)n/(2t+4) + O(1)$
+when $s < t$. We also determine lower and upper bounds on the saturation
+numbers of certain diameter-$4$ caterpillars.",2402.11387v2
+2024-03-08,Fault Recovery and Transient Stability of Grid-Forming Converters Equipped with Current Saturation,"When grid-forming (GFM) inverter-based resources (IBRs) experience large grid
+disturbances (e.g., short-circuit faults), the current limiter may be triggered
+and GFM IBRs enter the current saturation mode, inducing nonlinear dynamical
+behaviors and imposing great challenges to the post-disturbance transient angle
+stability. This paper presents a systematic study to reveal the fault recovery
+behaviors of a GFM IBR and identify the risk of instability. The impact of the
+angle of the magnitude-saturated current on the post-fault recovery and
+transient stability is also investigated. The selection of the angle of
+magnitude-saturated current significantly influences the post-fault behaviors
+while a few additional dynamical conditions that have a substantial impact are
+also identified. It is found that the system may follow multiple post-fault
+recovery trajectories depending on those conditions: 1) Convergence to the
+normal stable equilibrium point (SEP), 2) convergence to the saturated stable
+equilibrium point (SSEP), and 3) divergence (instability). To examine the
+models' accuracy, several cases are simulated.",2403.05236v1
+2024-01-07,Haze Removal via Regional Saturation-Value Translation and Soft Segmentation,"This paper proposes a single image dehazing prior, called Regional
+Saturation-Value Translation (RSVT), to tackle the color distortion problems
+caused by conventional dehazing approaches in bright regions. The RSVT prior is
+developed based on two key observations regarding the relationship between hazy
+and haze-free points in the HSV color space. First, the hue component shows
+marginal variation between corresponding hazy and haze-free points,
+consolidating a hypothesis that the pixel value variability induced by haze
+primarily occurs in the saturation and value spaces. Second, in the 2D
+saturation-value coordinate system, most lines passing through hazy-clean point
+pairs are likely to intersect near the atmospheric light coordinates.
+Accordingly, haze removal for the bright regions can be performed by properly
+translating saturation-value coordinates. In addition, an effective soft
+segmentation method based on a morphological min-max channel is introduced. By
+combining the soft segmentation mask with the RSVT prior, a comprehensive
+single image dehazing framework is devised. Experimental results on various
+synthetic and realistic hazy image datasets demonstrate that the proposed
+scheme successfully addresses color distortion issues and restores visually
+appealing images. The code of this work is available at
+https://github.com/tranleanh/rsvt.",2403.12054v1
+1996-09-19,Nonequilibrium Critical Dynamics of a Three Species Monomer-Monomer Model,"We study a three species monomer-monomer catalytic surface reaction model
+with a reactive steady state bordered by three equivalent unreactive phases
+where the surface is saturated with one species. The transition from the
+reactive to a saturated phase shows directed percolation critical behavior.
+Each pair of these reactive-saturated phase boundaries join at a bicritical
+point where the universal behavior is in the even branching annihilating random
+walk class. We find the crossover exponent from bicritical to critical behavior
+and a new exponent associated with the bicritical interface dynamics.",9609191v1
+1997-02-06,Boltzmann Collision Kernels and Velocity Saturation in Semiconductors,"For different models of the electron-phonon interaction, the asymptotic
+behaviour of the moments of the stationary homogeneous solution of the linear
+Boltzmann equation is determined in the limit of a high external field. For
+Hilbert-Schmidt kernels of a finite rank, a result recently proven for kernels
+of rank one is found generally valid; as a consequence velocity saturation is
+excluded for these collision models. For a class of singular collision kernels
+in contrast, velocity saturation is generally obtained.",9702062v1
+1998-08-18,Resistivity saturation revisited: results from a dynamical mean field theory,"We use the dynamical mean field method to study the high-temperature
+resistivity of electrons strongly coupled to phonons. The results reproduce the
+qualtiative behavior of the temperature and disorder dependence of the
+resistivity of the 'A-15' materials, which is commonly described in terms of
+saturation, but imply that the resistivity does not saturate. Rather, a change
+in temperature dependence occurs when the scattering becomes strong enough to
+cause a breakdown of the Migdal approximation.",9808188v2
+1999-03-18,Force fluctuations in granular materials,"Force fluctuations in granular materials are investigated. A continuum
+equation is derived starting from a discrete model proposed in the literature.
+The influence of boundary conditions is investigated. For periodic boundary
+conditions the average weight is found to increase linearly with depth while it
+saturates to a constant value for absorbing boundary conditions, which models
+the existence of walls. The scale dependencies of the saturation weight, the
+saturation depth and the average squared fluctuations are obtained. The
+analytical results are compared with previous works and with numerical
+simulations in one dimension.",9903282v2
+2001-08-21,Metals with Small Electron Mean-Free Path: Saturation versus Escalation of Resistivity,"Resistivity of metals is commonly observed either to 'escalate' beyond the
+Ioffe-Regel limit (mean free path l equal to lattice constant a) or to
+'saturate' at this point. It is argued that neither behavior is
+well-understood, and that 'escalation' is not necessarily more mysterious than
+'saturation.'",0108343v2
+2002-08-14,Can one hear the shape of a saturation patch?,"The theory of the acoustics of patchy-saturation in porous media is used to
+analyze experimental data on wave velocity and attenuation in partially water
+saturated limestones. It is demonstrated that the theory can be used to deduce
+the value of V/A, the ratio of the volume to area of the water patch, and l_f,
+the Poisson size of the water patch. One can ``hear'' the shape of a patch if
+the properties of the rock and the measurement frequencies are such as to
+satisfy the specific requirements for the validity of the theory.",0208290v1
+2002-10-17,Size effects on generation recombination noise,"We carry out an analytical theory of generation-recombination noise for a two
+level resistor model which goes beyond those presently available by including
+the effects of both space charge fluctuations and diffusion current. Finite
+size effects are found responsible for the saturation of the low frequency
+current spectral density at high enough applied voltages. The saturation
+behaviour is controlled essentially by the correlations coming from the long
+range Coulomb interaction. It is suggested that the saturation of the current
+fluctuations for high voltage bias constitutes a general feature of
+generation-recombination noise.",0210365v1
+2003-07-17,Photoassociation of a Quantum Degenerate Gas,"We have measured the intensity dependent rate and frequency shift of a
+photoassociation transition in a quantum degenerate gas of 7Li. The rate
+increases linearly with photoassociation laser intensity for low intensities,
+whereas saturation is observed at higher intensities. The measured rates and
+shifts agree reasonably well with theory within the estimated systematic
+uncertainties. Several theoretically predicted saturation mechanisms are
+discussed, but a theory in which saturation arises because of quantum
+mechanical unitarity agrees well with the data.",0307447v1
+2005-07-01,Pattern reconstruction and sequence processing in feed-forward layered neural networks near saturation,"The dynamics and the stationary states for the competition between pattern
+reconstruction and asymmetric sequence processing are studied here in an
+exactly solvable feed-forward layered neural network model of binary units and
+patterns near saturation. Earlier work by Coolen and Sherrington on a parallel
+dynamics far from saturation is extended here to account for finite stochastic
+noise due to a Hebbian and a sequential learning rule. Phase diagrams are
+obtained with stationary states and quasi-periodic non-stationary solutions.
+The relevant dependence of these diagrams and of the quasi-periodic solutions
+on the stochastic noise and on initial inputs for the overlaps is explicitly
+discussed.",0507039v1
+2004-06-17,Abstract Canonical Inference,"An abstract framework of canonical inference is used to explore how different
+proof orderings induce different variants of saturation and completeness.
+Notions like completion, paramodulation, saturation, redundancy elimination,
+and rewrite-system reduction are connected to proof orderings. Fairness of
+deductive mechanisms is defined in terms of proof orderings, distinguishing
+between (ordinary) ""fairness,"" which yields completeness, and ""uniform
+fairness,"" which yields saturation.",0406030v2
+2001-01-23,Asymptotic Freedom in Curvature-Satured Gravity,"For a spatially flat Friedmann model with line element $ds^2=a^2 [
+da^2/B(a)-dx^2-dy^2-dz^2 ] $, the 00-component of the Einstein field equation
+reads $8\pi G T_{00}=3/a^2$ containing no derivative. For a nonlinear
+Lagrangian ${\cal L}(R)$, we obtain a second--order differential equation for
+$B$ instead of the expected fourth-order equation. We discuss this equation for
+the curvature-saturated model proposed by Kleinert and Schmidt. Finally, we
+argue that asymptotic freedom $G_{{\rm eff}}^{-1}\to 0$ is fulfilled in
+curvature-saturated gravity.",0101090v2
+1996-08-07,Unitarity and Saturation in the Dipole Formulation,"This talk reviews briefly some of the main results of the small-x dipole
+formulation with regards to unitarity corrections. It illustrates the
+correspondence between unitarity and saturation corrections in the dipole
+approach and multiple t-channel pomeron exchange in the traditional BFKL view,
+and discusses how one can estimate and understand the effects of saturation.",9608250v1
+1999-03-15,Saturation in Diffractive Deep Inelastic Scattering,"We successfully describe the HERA-data on diffractive deep inelastic
+scattering using a saturation model which has been applied in our earlier
+analysis of the inclusive $ep$-scattering data. No further parameters are
+needed. Saturation already turned out to be essential in describing the
+transition from large to small values of $Q^2$ in inclusive scattering. It is
+even more important for diffractive processes and naturally leads to a constant
+ratio of the diffractive versus inclusive cross sections. We present an
+extensive discussion of our results as well as detailed comparison with data.",9903358v2
+2001-01-24,Nonlinear evolution and saturation for heavy nuclei in DIS,"The nonlinear evolution equation for the scattering amplitude of colour
+dipole off the heavy nucleus is solved in the double logarithmic approximation.
+It is found that if the initial parton density in a nucleus is smaller then
+some critical value, then the scattering amplitude is a function of one scaling
+variable inside the saturation region, whereas if it is greater then the
+critical value, then the scaling behaviour breaks down. Dependence of the
+saturation scale on the number of nucleons is discussed as well.",0101275v2
+2001-09-03,Saturation and geometric scaling in DIS at small x,"We present various aspects of the saturation model which provides good
+description of inclusive and diffractive DIS at small x. The model uses parton
+saturation ideas to take into account unitarity requirements. A new scaling
+predicted by the model in the small x domain is successfully confronted with
+the data.",0109010v2
+2001-11-19,Initial state of the QGP from perturbative QCD + saturation,"The production of the initial state of the QGP in very high-energy $AA$
+collisions is discussed within the framework of perturbative QCD and
+saturation. The next-to-leading order computation of the transverse energy of
+minijets is reviewed. Saturation of parton production, conjectured to occur at
+a dynamically determinable perturbative scale, leads to estimates of the
+initial densities. The final state multiplicities are predicted by assuming an
+isentropic hydrodynamical further evolution. Comparison with RHIC data is
+shown.",0111223v1
+2002-05-15,The Energy Dependence of the Saturation Momentum,"We study BFKL evolution and, in particular, the energy dependence of the
+saturation momentum in the presence of saturation boundaries limiting the
+region of linear BFKL evolution. In the case of fixed coupling evolution we
+confirm the previously found exponential term in $Q_s(Y)$ and determine the
+prefactor $Y$ and $\alpha$ dependences. In the running coupling case we find
+$Y^{1/6}$ corrections to the $Y^{1/2}$exponential behavior previously known.
+Geometrical scaling of the scattering amplitude is valid in a wide-range of
+momenta for fixed coupling evolution and in a more restricted region for
+running coupling evolution.",0205167v1
+2002-05-30,Gluon Saturation and S-Matrix Unitarity,"The impact parameter dependent gluon distribution of the proton xG(x,Q^2,b)
+is investigated in a loop-loop correlation model that respects the S-matrix
+unitarity condition in impact parameter space. We find low-x saturation of
+G(x,Q^2,b) as a manifestation of S-matrix unitarity. The integrated gluon
+distribution xG(x,Q^2) does not saturate because of the growth of the effective
+proton radius with decreasing x.",0205343v1
+2002-06-14,Saturation model for 2-gamma physics,"We introduce a saturation model for photon-photon interactions, based on a
+QCD dipole picture of high energy scattering. The two-dipole cross-section is
+assumed to satisfy the saturation property. This pomeron-like contribution is
+supplemented with QPM and non-pomeron reggeon contributions. The model gives a
+very good description of the data on the gamma-gamma total cross-section, on
+the photon structure function F_2^gamma(x,Q^2) at low x and on the
+gamma*-gamma* cross-section.",0206130v1
+2002-08-01,Saturation and Pion Production in Proton-Nucleus Collisions,"We study the effects of gluon saturation on pion production in high energy
+proton-nucleus collisions using the color glass condensate model. At high
+p_perp, we show that the p_perp-distribution of gluons behaves as ~
+1/(p_perp^7) in accordance with both conventional perturbative QCD calculations
+and experiment. Fragmentation of gluons into pions leads to a rapidity
+dependent depletion of pions relative to the conventional perturbative QCD
+predictions. We argue that these clear and systematic differences provide a
+signal for the onset of gluon saturation which is accessible in upcoming
+experiments.",0208007v1
+2002-10-16,The Colour Glass Condensate,"I review the physical and mathematical foundations for the theoretical
+description of the hadron wavefunction at small $x$ as a Colour Glass
+Condensate. In this context, I discuss the phenomenon of gluon saturation and
+some of its remarkable consequences: a new ``geometric scaling'' for $F_2$,
+which has been recently identified at HERA, and the unitarization of the
+hadronic cross-sections at high energy. I show that by combining saturation and
+confinement one obtains cross-sections which saturate the Froissart bound.",0210236v2
+2002-12-09,A Gaussian effective theory for gluon saturation,"We construct a Gaussian approximation to the effective theory for the Colour
+Glass Condensate which describes correctly the gluon distribution both in the
+low density regime at high transverse momenta (above the saturation scale
+$Q_s$), and in the high density regime below $Q_s$, and provides a simple
+interpolation between these two regimes. At high momenta, the effective theory
+reproduces the BFKL dynamics, while at low momenta, it exhibits gluon
+saturation and, related to it, colour neutrality over the short distance scale
+$1/Q_s \ll 1/\Lambda_{QCD}$. Gauge--invariant quantities computed within this
+approximation are automatically infrared finite.",0212123v1
+2003-05-05,Nuclear Heavy Quark Photoproduction in a Saturation Model,"We calculate the nuclear inclusive and diffractive cross sections for heavy
+quark photoproduction within a phenomenological saturation approach. The
+nuclear cross section is obtained by the extension of the saturation model
+through Glauber-Gribov formalism. We predict large nuclear heavy quark cross
+section at LHC energies.",0305045v2
+2003-12-01,Diffractive photon dissociation in the saturation regime from the Good and Walker picture,"Combining the QCD dipole model with the Good and Walker picture, we formulate
+diffractive dissociation of a photon of virtuality Q^2 off a hadronic target,
+in the kinematical regime in which Q is close to the saturation scale and much
+smaller than the invariant mass of the diffracted system. We show how the
+obtained formula compares to the HERA data and discuss what can be learnt from
+such a phenomenology. In particular, we argue that diffractive observables in
+these kinematics provide useful pieces of information on the saturation regime
+of QCD.",0312022v1
+2004-07-01,QCD Saturation Equations including Dipole-Dipole Correlation,"We derive two coupled non-linear evolution equations corresponding to the
+truncation of the Balitsky infinite hierarchy of saturation equations after
+inclusion of dipole-dipole correlations, i.e. one step beyond the
+Balitsky-Kovchegov (BK) equation. We exhibit an exact solution for maximal
+correlation which still satisfies the same asymptotic geometric scaling as BK
+but with the S-matrix going to 1/2 (instead of 0) in the full saturation
+region.",0407007v2
+2004-07-22,Low x saturation at HERA ?,"We compare the predictions of two distinct dipole models for inclusive and
+exclusive diffractive processes. While only one of these dipole models contains
+perturbative saturation dynamics, we show that the predictions of both models
+are fully consistent with the available HERA data, indicating no compelling
+evidence for saturation at present HERA energies.",0407261v1
+2004-10-01,Parton Saturation Approach in Heavy Quark Production at High Energies,"The high parton density regime of the Quantum Chromodynamics (QCD), where the
+physics of parton saturation is expected to be dominant, is briefly discussed.
+Some phenomenological aspects of saturation are described, mainly focusing on
+possible signatures of the non-linear QCD dynamics in the heavy quark
+production in electron-proton/nucleus collisions. Implications of these effects
+in the heavy quark production in ultraperipheral heavy-ion collisions are also
+presented.",0410012v2
+2004-11-25,Gluon Saturation in the Colour Dipole Model?,"We use data on the deep inelastic structure function F_2 in order to
+constrain the cross-section for scattering a colour dipole off a proton. The
+data seem to prefer parameterisations which include saturation effects. That is
+they indicate that the strong rise with energy of the dipole cross-section,
+which holds for small dipoles, pertains only for r < r_s(x) where r_s(x)
+decreases monotonically as x decreases. Subsequent predicitions for the
+diffractive structure function F_2^{D(3)} also hint at saturation, although the
+data are not really sufficiently accurate.",0411337v1
+2004-12-06,Nonlinear evolution equations in QCD,"The following lectures are an introduction to the phenomena of partonic
+saturation and nonlinear evolution equations in Quantum Chromodynamics. After a
+short introduction to the linear evolution, the problems of unitarity bound and
+parton saturation are discussed. The nonlinear Balitsky-Kovchegov evolution
+equation in the high energy limit is introduced, and the progress towards the
+understanding of the properties of its solution is reviewed. We discuss the
+concepts of the saturation scale, geometrical scaling and the lack of the
+infrared diffusion. Finally, we give a brief summary of current theoretical
+developments which extend beyond the Balitsky-Kovchegov equation.",0412084v1
+2005-10-13,Particle production and saturation at HERA,"Perturbative QCD in the high-energy limit describes the evolution of
+scattering amplitudes with increasing energy towards and into the so-called
+saturation regime. Comparisons of the predictions with experimental data for a
+number of observables led to significant progress and understanding. We discuss
+the case of particle-production cross-sections measured at HERA and argue that
+these measurements have the potential to provide evidence for the saturation
+regime of QCD.",0510176v1
+2007-01-22,Has saturation physics been observed in deuteron-gold collisions at RHIC?,"We have addressed the question of whether saturation (CGC) has been observed
+in deuteron-gold collisions at RHIC. We have made a detailed analysis of the
+Cronin peak characteristic of the nuclear modification factor measured for d-Au
+collisions at mid-rapidity. The Cronin peak which is obtained around $p_t\simeq
+3$ GeV may be reproduced at the proper height only by boosting the saturation
+momentum by a huge non-perturbative additional component. At forward rapidity,
+we get a quantitative agreement with data, reproducing hadron production
+spectra and the $R_{CP}$ ratio using a recently developed description of the
+small-x physics.",0701184v1
+2007-01-29,Reflective scattering from unitarity saturation,"Proceeding from optical analogy we propose a new physical interpretation of
+unitarity saturation leading to antishadowing as a reflective scattering. This
+interpretation of antishadowing is related to the non-perturbative aspects of
+strong interactions and follows from the specific property of the unitarity
+saturation when elastic $S$-matrix $S(s,b)|_{b=0}\to -1$ at $s\to \infty$. The
+analogy with Berry phase and experimental consequences of the proposed
+interpretation as reflective scattering at the LHC and in the cosmic rays
+studies are discussed.",0701241v4
+1997-12-23,The entropy of near-extreme N=2 black holes,"We give an explicit form of the classical entropy for four-dimensional static
+near-BPS-saturated black holes of generic N=2 superstring vacua. The expression
+is obtained by determining the leading corrections in the non-extremality
+parameter to the corresponding BPS-saturated black hole solutions. These
+classical results are quantitatively compared with the microscopic leading
+order corrections to the microscopic result of Maldacena Strominger and Witten
+for N=2 BPS-saturated black holes.",9712221v1
+2000-05-12,Abrikosov String in N=2 Supersymmetric QED,"We study the Abrikosov-Nielsen-Olesen string in N=2 supersymmetric QED with
+N=2-preserving superpotential, in which case the Abrikosov string is found to
+be 1/2-BPS saturated. Adding a quadratic small perturbation in the
+superpotential breaks N=2 supersymmetry to N=1 supersymmetry. Then the
+Abrikosov string is no longer BPS saturated. The difference between the string
+tensions for the non-BPS and BPS saturated situation is found to be negative to
+the first order of the perturbation parameter.",0005119v2
+1998-10-30,The saturation conjecture (after A. Knutson and T. Tao),"In this exposition we give a simple and complete treatment of A. Knutson and
+T. Tao's recent proof (http://front.math.ucdavis.edu/math.RT/9807160) of the
+saturation conjecture, which asserts that the Littlewood-Richardson semigroup
+is saturated. The main tool is Knutson and Tao's hive model for
+Berenstein-Zelevinsky polytopes. In an appendix of W. Fulton it is shown that
+the hive model is equivalent to the original Littlewood-Richardson rule.",9810180v1
+2002-04-17,Generators and representability of functors in commutative and noncommutative geometry,"We give a sufficient condition for an Ext-finite triangulated category to be
+saturated. Saturatedness means that every contravariant cohomological functor
+of finite type to vector spaces is representable. The condition consists in
+existence of a strong generator. We prove that the bounded derived categories
+of coherent sheaves on smooth proper commutative and noncommutative varieties
+have strong generators, hence saturated. In contrast the similar category for a
+smooth compact analytic surface with no curves is not saturated.",0204218v2
+2002-08-13,Geometric Proofs of Horn and Saturation Conjectures,"We provide a geometric proof of the Schubert calculus interpretation of the
+Horn conjecture, and show how the saturation conjecture follows from it. The
+geometric proof gives a strengthening of Horn and saturation conjectures. We
+also establish transversality theorems for Schubert calculus in non-zero
+characteristic.
+  Some parts of the version posted in Nov 2002 (concerning explicit invariants
+constructed from Schubert calculus) have been removed from this version. They
+have appeared separately in IMRN 2004, no. 69, pages 3709--3721 "" Invariant
+theory of GL(n) and Intersection theory of Grassmannians""",0208107v3
+2003-03-06,Paracategories I: internal parategories and saturated partial algebras,"Based on the monoid classifier, we give an alternative axiomatization of
+Freyd's paracategories, which can be interpreted in any bicategory of partial
+maps. Assuming furthermore a free-monoid monad T in our ambient category, and
+coequalisers satisfying some exactness conditions, we give an abstract envelope
+construction, putting paramonoids (and paracategories) in the more general
+context of partial algebras. We introduce for the latter the crucial notion of
+saturation, which characterises those partial algebras which are isomorphic to
+the ones obtained from their enveloping algebras. We also set up a
+factorisation system for partial algebras, via epimorphisms and (monic) Kleene
+morphisms and relate the latter to saturation.",0303083v1
+2006-01-10,Steady free convection in a bounded and saturated porous medium,"In this paper we are interested with a strongly coupled system of partial
+differential equations that modelizes free convection in a two-dimensional
+bounded domain filled with a fluid saturated porous medium. This model is
+inspired by the one of free convection near a semi-infinite impermeable
+vertical flat plate embedded in a fluid saturated porous medium. We establish
+the existence and uniqueness of the solution for small data in some unusual
+spaces.",0601219v1
+2000-08-18,Periodically kicked turbulence,"Periodically kicked turbulence is theoretically analyzed within a mean field
+theory. For large enough kicking strength A and kicking frequency f the
+Reynolds number grows exponentially and then runs into some saturation. The
+saturation level can be calculated analytically; different regimes can be
+observed. For large enough Re we find the saturation level to be proportional
+to A*f, but intermittency can modify this scaling law. We suggest an
+experimental realization of periodically kicked turbulence to study the
+different regimes we theoretically predict and thus to better understand the
+effect of forcing on fully developed turbulence.",0008025v1
+2006-02-20,Spatial synchronization and extinction of species under external forcing,"We study the interplay between synchronization and extinction of a species.
+Using a general model we show that under a common external forcing, the species
+with a quadratic saturation term in the population dynamics first undergoes
+spatial synchronization and then extinction, thereby avoiding the rescue
+effect. This is because the saturation term reduces the synchronization time
+scale but not the extinction time scale. The effect can be observed even when
+the external forcing acts only on some locations provided there is a
+synchronizing term in the dynamics. Absence of the quadratic saturation term
+can help the species to avoid extinction.",0602041v1
+1999-01-08,Saturation of product's exoticity in compound nuclear reactions and its role in the production of new n-deficient nuclei with radioactive projectiles,"Representation in terms of a new parameter, exoticity, a measure of
+n-deficiency or p-richness, clearly brings out the saturation tendency of the
+product's maximum exoticity in a compound nuclear reaction as the compound
+nucleus is made more and more exotic using radioactive projectile (RIBs). The
+effect of this saturation on the production of new proton-rich species with
+RIBs over a wide Z-range has been discussed.",9901015v1
+1999-06-15,Effective field theory for nuclear matter,"We apply the relativistic chiral Lagrangian to the nuclear equation of state.
+An effective chiral power expansion scheme, which is constructed to work around
+nuclear saturation density, is presented. The leading and subleading terms are
+evaluated and are shown to provide an equation of state with excellent
+saturation properties. Our saturation mechanism is found to probe details of
+the nuclear pion dynamics.",9906045v1
+2001-02-15,Nuclear Matter EOS with a Three-body Force,"The effect of a microscopic three-body force on the saturation properties of
+nuclear matter is studied within the Brueckner-Hartree-Fock approach. The
+calculations show a decisive improvement of the saturation density along with
+an overall agreement with the empirical saturation point. With the three-body
+force the symmetry energy turns more rapidly increasing with density, which
+allows for the direct URCA process to occur in $\beta$-stable neutron star
+matter. The influence of the three-body force on the nuclear mean field does
+not diminish the role of the ground state correlations.",0102038v1
+2004-12-26,"Cronin momentum behavior in saturation model for $p+A$, $d+A$, $A+A$ collisions","In this paper we consider Cronin momentum behaviour for $p+A$, $d+A$ and
+$A+A$ collisions in saturation model. Our analysis shows that Cronin momentum
+behavior at different rapidities and energies, can be related with scaling law
+using simple dimensional consideration. Using exact numerical solution of
+Balitsky-Kovchegov equation we show that although this dependence is slightly
+different for McLerran-Venugopalan and Balitsky-Kovchegov definition of gluon
+distribution function in simple model in this case dependencies is almost the
+same (i.e ratio of Cronin momentum calculated using these gluon distribution
+functions is big constant). This can be used to experimentally distinguish this
+two variant of gluon distribution function definition in saturation model and
+choose the right one.",0412098v1
+2004-11-25,220 fs Er-Yb:glass laser mode-locked by a broadband low-loss Si/Ge saturable absorber,"We demonstrate femtosecond performance of an ultra-broadband
+high-index-contrast saturable Bragg reflector consisting of a
+silicon/silicon-dioxide/germanium structure that is fully compatible with CMOS
+processing. This device offers a reflectivity bandwidth of over 700 nm and
+sub-picosecond recovery time of the saturable loss. It is used to achieve
+mode-locking of an Er-Yb:glass laser centered at 1540 nm, generating 220 fs
+pulses, with the broadest output spectrum to date.",0411232v1
+2005-08-01,Phase diagram of a ternary mixture of cholesterol and saturated and unsaturated lipids calculated from a microscopic model,"We employ a molecular model to study a ternary mixture of saturated lipid,
+with tails of sixteen carbons, a mono unsaturated lipid with tails of eighteen
+carbons, and cholesterol. The model, solved within mean-field theory, produces
+several forms of phase diagrams depending upon the relative strengths of
+interactions, but only one that shows the coexistence of two liquid phases
+observed in experiment. The lipids in the phase rich in cholesterol are more
+ordered than those in the other. The binary cholesterol, saturated lipid system
+also exhibits liquid, liquid coexistence.",0508011v1
+2005-12-16,Saturable absorption and 'slow light',"Quantitative evaluation of some recent 'slow light' experiments based on
+coherent population oscillations (CPO) shows that they can be more simply
+interpreted as saturable absorption phenomena. Therefore they do not provide an
+unambiguous demonstration of 'slow light'. Indeed a limiting condition on the
+spectral bandwidth is not generally satisfied, such that the requirements for
+burning a narrow spectral hole in the homogeneously broadened absorption line
+are not met. Some definitive tests of 'slow light' phenomena are suggested,
+derived from analysis of phase shift and pulse delay for a saturable absorber",0512149v2
+2002-10-09,Fidelity Decay Saturation Level for Initial Eigenstates,"We show that the fidelity decay between an initial eigenstate state evolved
+under a unitary chaotic operator and the same eigenstate evolved under a
+perturbed operator saturates well before the 1/N limit, where $N$ is the size
+of the Hilbert space, expected for a generic initial state. We provide a
+theoretical argument and numerical evidence that, for intermediate perturbation
+strengths, the saturation level depends quadratically on the perturbation
+strength.",0210063v1
+2006-03-10,Saturation of fidelity in the atom-optics kicked rotor,"We show that the quantum fidelity is accessible to cold atom experiments for
+a large class of evolutions in periodical potentials, properly taking into
+account the experimental initial conditions of the atomic ensemble. We prove
+analytically that, at the fundamental quantum resonances of the atom-optics
+kicked rotor, the fidelity saturates at a constant, time-independent value
+after a small number of kicks. The latter saturation arises from the bulk of
+the atomic ensemble, whilst for the resonantly accelerated atoms the fidelity
+is predicted to decay slowly according to a power law.",0603095v1
+2007-05-01,Non-abelian plasma instabilities for strong anisotropy,"We numerically investigate gauge field instabilities in anisotropic SU(2)
+plasmas using weak field initial conditions. The growth of unstable modes is
+stopped by non-abelian effects for moderate anisotropy. If we increase the
+anisotropy the growth continues beyond the non-abelian saturation bound. We
+find strong indications that the continued growth is not due to over-saturation
+of infrared field modes, but instead due to very rapid growth of high momentum
+modes which are not unstable in the weak field limit. The saturation amplitude
+strongly depends on the initial conditions. For strong initial fields we do not
+observe the sustained growth.",0705.0180v1
+2008-03-05,Ultimate field-free molecular alignment by combined adiabatic-impulsive field design,"We show that a laser pulse designed as an adiabatic ramp followed by a kick
+allows one to reach a perfect postpulse molecular alignment, free of
+saturation. The mechanism is based on an optimized distribution of the energy
+between a weakly efficient but non saturating adiabatic ramp and an efficient
+but saturating impulsive field. Unprecedent degrees of alignment are predicted
+using state-of-the-art pulse shaping techniques and non-destructive field
+intensities. The scheme can be extended to reach high degrees of orientation of
+polar molecules using designed half-cycle pulses.",0803.0711v1
+2008-04-03,Polarization Saturation in Strained Ferroelectrics,"Using density-functional calculations we study the structure and polarization
+response of tetragonal PbTiO3, BaTiO3 and SrTiO3 in a strain regime that is
+previously overlooked. Different from common expectations, we find that the
+polarizations in all three substances saturate at large strains, demonstrating
+a universal phenomenon. The saturation is shown to originate from an unusual
+and strong electron-ion correlation that leads to cancellation between
+electronic and ionic polarizations. Our results shed new insight on the
+polarization properties, and reveal the existence of a fundamental limit to the
+strain-induced polarization enhancement.",0804.0630v1
+2008-04-11,Running Coupling Effects in Small-x QCD,"We study effects of the running of the coupling in QCD at small Bjorken-x and
+in particular the ones related to gluon saturation. After introducing the steps
+taken to the derivation of the next to leading order nonlinear evolution
+equation, we discuss the infrared sensitivity of the Pomeron intercept, the
+energy dependence of the saturation momentum and the appearance of geometrical
+scaling, and the dominance of the running coupling effects over the ones
+introduced by loops of Pomerons.",0804.1918v1
+2008-06-30,The dipole picture in DIS: saturation and heavy quarks,"We discuss the description of the proton structure function within the dipole
+factorisation framework. We parametrise the forward dipole amplitude to account
+for saturation as predicted by the small-x QCD evolution equations. Contrarily
+to previous models, the saturation scale does not decrease when taking heavy
+quarks into account. We show that the same dipole amplitude also allows to
+reproduce diffractive data and exclusive vector meson production.",0807.0020v1
+2008-09-02,Interaction Grammars,"Interaction Grammar (IG) is a grammatical formalism based on the notion of
+polarity. Polarities express the resource sensitivity of natural languages by
+modelling the distinction between saturated and unsaturated syntactic
+structures. Syntactic composition is represented as a chemical reaction guided
+by the saturation of polarities. It is expressed in a model-theoretic framework
+where grammars are constraint systems using the notion of tree description and
+parsing appears as a process of building tree description models satisfying
+criteria of saturation and minimality.",0809.0494v1
+2008-09-16,High energy scattering in the saturation regime including running coupling and rare fluctuation effects,"The analytic result for the $S$-matrix in the saturation regime including the
+running coupling is obtained. To get this result we solve the Balitsky and
+Kovchegov-Weigert evolution equations in the saturation regime, which include
+running coupling corrections. We study also the effect of rare fluctuations on
+top of the running coupling. We find that the rare fluctuations are less
+important in the running coupling case as compared to the fixed coupling case.",0809.2666v1
+2008-09-24,Dipole models and parton saturation in ep scattering,"In this contribution we briefly review the current status of the dipole
+models and parton saturation on the basis of results presented at the HERA-LHC
+workshops in the years 2006-2008. The problem of foundations of the dipole
+models is addressed within the QCD formalism. Some limitations of the models
+and open problems are pointed out. Furthermore, we review and compare the
+currently used dipole models and summarise the applications to describe various
+sets of HERA data. Finally we outline some of the theoretical approaches to the
+problem of multiple scattering and saturation.",0809.4191v1
+2008-11-21,Influence of higher-order harmonics on the saturation of the tearing mode,"The nonlinear saturation of the tearing mode is revisited in slab geometry by
+taking into account higher-order harmonics in the outer solution. The general
+formalism for tackling this problem in the case of a vanishing current gradient
+at the resonant surface is derived. It is shown that, although the higher-order
+harmonics lead to corrections in the final saturation equation, they are of
+higher order in the perturbation parameter, which provides a formal proof that
+the standard one-harmonic approach is asymptotically correct.",0811.3651v1
+2008-12-09,Heavy ions and parton saturation from RHIC to LHC,"The phenomenology of gluon saturation at small parton momentum fraction,
+Bjorken-x, in the proton and in the nucleus is introduced. The
+experimentally-accessible kinematic domains at the nucleus-nucleus colliders
+RHIC and LHC are discussed. Finally, the saturation hints emerging from
+measurements at RHIC and the perspectives for LHC are described.",0812.1607v3
+2008-12-22,Saturation effects in final states due to CCFM with absorptive boundary,"We apply the absorptive boundary prescription to include saturation effects
+in CCFM evolution equation. We are in particular interested in saturation
+effects in exclusive processes which can be studied using Monte Carlo event
+generator CASCADE. We calculate cross section for three-jet production and
+distribution of charged hadrons.",0812.4082v2
+2009-05-15,"Multiple Interactions, Saturation, and Final States in pp Collisions and DIS","In high energy collisions saturation and multiple collisions are most easily
+accounted for in transverse coordinate space, while analyses in momentum space
+have been more suitable for calculating properties of exclusive final states.
+In this talk I describe an extension of Mueller's dipole cascade model, which
+attempts to combine the good features of both these descriptions. Besides
+saturation it also includes effects of correlations and fluctuations, which
+have been difficult to account for in previous approaches. The model reproduces
+successfully total, elastic, and diffractive cross sections in pp collisions
+and DIS, and a description of final states will be ready soon.",0905.2492v1
+2009-05-31,Transport properties of graphene in the high-current limit,"We present a detailed study of the high-current transport properties of
+graphene devices patterned in a four-point configuration. The current tends to
+saturate as the voltage across graphene is increased but never reaches the
+complete saturation as in metallic nanotubes. Measurements are compared to a
+model based on the Boltzmann equation, which includes electron scattering
+processes due to charged and neutral impurities, and graphene optical-phonons.
+The saturation is incomplete because of the competition between disorder and
+optical-phonon scattering.",0906.0188v1
+2009-06-16,Hydrodynamic theory of transport in doped graphene,"We study non-linear dc transport in graphene using a hydrodynamic approach
+and conclude that in clean samples the drift velocity saturates at a weakly
+density-dependent value v_{sat} ~ 10^7 cm/s. We show that saturation results
+from the interactions between graphene's Dirac quasi-particles and both
+acoustic and optical phonons. Saturation is accompanied by substantial electron
+heating and is not reached at realistic driving fields in moderately or
+strongly disordered samples. We find that it is essential to account for
+interactions among graphene's Dirac quasi-particles, which increase the linear
+response resistivity at high temperatures or low densities.",0906.2992v1
+2009-08-12,The complexity of classification problems for models of arithmetic,"We observe that the classification problem for countable models of arithmetic
+is Borel complete. On the other hand, the classification problems for finitely
+generated models of arithmetic and for recursively saturated models of
+arithmetic are Borel; we investigate the precise complexity of each of these.
+Finally, we show that the classification problem for pairs of recursively
+saturated models and for automorphisms of a fixed recursively saturated model
+are Borel complete.",0908.1718v2
+2010-01-24,Measuring the saturation scale in nuclei,"The saturation momentum seeing in the nuclear infinite momentum frame is
+directly related to transverse momentum broadening of partons propagating
+through the medium in the nuclear rest frame. Calculation of broadening within
+the color dipole approach including the effects of saturation in the nucleus,
+gives rise to an equation which describes well data on broadening in Drell-Yan
+reaction and heavy quarkonium production.",1001.4281v1
+2010-04-21,Terahertz Response of Field-Effect Transistors in Saturation Regime,"We report on the broadband THz response of InGaAs/GaAs HEMTs operating at
+1.63 THz and room temperature deep in the saturation regime. We demonstrate
+that responses show linear increase with drain-to-source voltage (or drain bias
+current) and reach very high values up to 170V/W. We also develop a
+phenomenological theory valid both in the ohmic and in the saturation regimes.",1004.3740v1
+2010-04-27,Stabilization of two-dimensional solitons in cubic-saturable nonlinear lattices,"We consider soliton dynamics and stability in a nonlinear lattice formed by
+alternating domains with focusing cubic and saturable nonlinearities. We find
+that in such lattices solitons centered on cubic domains may be stabilized even
+in two-dimensional geometries, in spite of their intrinsic catastrophic
+instability in the absence of the lattice. Solitons centered on saturable
+domains are always unstable.",1004.4771v1
+2010-05-31,Saturation of the Raman amplification by self-phase modulation in silicon nanowaveguides,"We experimentally show that the self-phase modulation of picosecond pump
+pulses, induced by both the optical Kerr effect and free-carrier refraction,
+has a detrimental effect on the maximum on-off Raman gain achievable in silicon
+on insulator nanowaveguides, causing it to saturate. A simple calculation of
+the Raman gain coefficient from the measured broadened output pump spectra
+perfectly matches the saturated behavior of the amplified Raman signal observed
+experimentally at different input pump powers.",1005.5599v1
+2010-07-09,Fusion systems on small p-groups,"In this article we study several classes of `small' 2-groups: we complete the
+classification, started in [Stancu, 2006], of all saturated fusion systems on
+metacyclic p-groups for all primes p. We consider Suzuki 2-groups, and classify
+all center-free saturated fusion systems on 2-groups of 2-rank 2. We end by
+classifying all possible F-centric, F-radical subgroups in saturated fusion
+systems on 2-groups of 2-rank 2.",1007.1639v1
+2010-07-20,High-field Carrier Velocity and Current Saturation in Graphene Field-Effect Transistors,"We obtain the output characteristics of graphene field-effect transistors by
+using the charge-control model for the current, based on the solution of the
+Boltzmann equation in the field-dependent relaxation time approximation. Closed
+expressions for the conductance, transconductance and saturation voltage are
+derived. We found good agreement with the experimental data of Meric et al.
+[1], without assuming a carrier density-dependent velocity saturation.",1007.3504v1
+2010-09-07,Parton saturation at strong coupling from AdS/CFT,"I describe the parton picture at strong coupling emerging from the
+gauge/gravity duality, with emphasis on the universality of the phenomenon of
+parton saturation. I discuss several consequences of this picture for the
+phenomenology of a strongly coupled quark-gluon plasma, which are potentially
+relevant for heavy ion collisions at RHIC and LHC.",1009.1278v1
+2010-09-21,Low scale saturation of Effective NN Interactions and their Symmetries,"The Skyrme force parameters can be uniquely determined by coarse graining the
+NN interactions at a characteristic momentum scale. We show how exact Vlowk
+potentials to second order in momenta are accurately and universally saturated
+with physical NN scattering threshold parameters at CM momentum scales of about
+Lambda=250 MeV for the S-waves and Lambda=100 MeV for the P-waves. The pattern
+of Wigner and Serber symmetries unveiled previously is also saturated at these
+scales.",1009.4161v2
+2010-12-06,Dark solitons in mode-locked lasers,"Dark soliton formation in mode-locked lasers is investigated by means of a
+power-energy saturation model which incorporates gain and filtering saturated
+with energy, and loss saturated with power. It is found that general initial
+conditions evolve into dark solitons under appropriate requirements also met in
+the experimental observations. The resulting pulses are well approximated by
+dark solitons of the unperturbed nonlinear Schr\""{o}dinger equation. Notably,
+the same framework also describes bright pulses in anomalous and normally
+dispersive lasers.",1012.1366v1
+2011-01-26,Azimuthal correlations of forward di-hadrons in d+Au collisions suppressed by saturation,"RHIC experiments have recently measured the azimuthal correlation function of
+forward di-hadrons. The data show a disappearance of the away-side peak in
+central d+Au collisions, compared to p+p collisions, as was predicted by
+saturation physics. Indeed, we argue that this effect, absent at mid-rapidity,
+is a consequence of the small-x evolution into the saturation regime of the
+Gold nucleus wave function. We show that the data are well described in the
+Color Glass Condensate framework.",1101.5109v1
+2011-01-31,Inclusive hadron distributions in p+p collisions from saturation models of HERA DIS data,"Dipole models based on various saturation scenarios provide reasonable fits
+to small-x DIS inclusive, diffractive and exclusive data from HERA. Proton
+un-integrated gluon distributions extracted from such fits are employed in a
+$k_\bot$-factorization framework to calculate inclusive gluon distributions at
+various energies. The n-particle multiplicity distribution predicted in the
+Glasma flux tube approach shows good agreement with data over a wide range of
+energies. Hadron inclusive transverse momentum distributions expressed in terms
+of the saturation scale demonstrate universal behavior over a wider kinematic
+range systematically with increasing center of mass energies.",1101.5922v1
+2011-02-25,On the composition product of saturated fusion systems,"We say that a fusion system is the composition product of two subsystems if
+every morphism can be factored as a morphism in one fusion system followed by a
+morphism in the other. We establish a relationship between the characteristic
+idempotent of a saturated fusion system that is the composition product of
+saturated subsystems and the characteristic idempotents of the component
+systems. Consequently we obtain a compatibility result for transfer through the
+composition product and transfer through the component systems.",1102.5280v1
+2011-06-27,Extended maximum concurrent flow problem with saturated capacity,"The present work studies a kind of Maximum Concurrent Flow Problem, called as
+Extended Maximum Concurrent Flow Problem with Saturated Capacity. Our major
+contributions are as follows: (A) Propose the definition of Extensive Maximum
+Concurrent Flow Problem with Saturated Capacity and prove its solutions exist.
+(B) Design a approximation algorithm to solve the problem. (C) Propose and
+prove the complexity and the approximation measures of the algorithm we design.",1106.5421v2
+2011-10-18,Algorithms for strongly stable ideals,"Strongly stable monomial ideals are important in algebraic geometry,
+commutative algebra, and combinatorics. Prompted, for example, by combinatorial
+approaches for studying Hilbert schemes and the existence of maximal total
+Betti numbers among saturated ideals with a given Hilbert polynomial, in this
+note we present three algorithms to produce all strongly stable ideals with
+certain prescribed properties: the saturated strongly stable ideals with a
+given Hilbert polynomial, the almost lexsegment ideals with a given Hilbert
+polynomial, and the saturated strongly stable ideals with a given Hilbert
+function. We also establish results for estimating the complexity of our
+algorithms.",1110.4080v2
+2011-10-23,On locally defined formations of soluble Lie and Leibniz algebras,"It is well-known that all saturated formations of finite soluble groups are
+locally defined and, except for the trivial formation, have many different
+local definitions. I show that for Lie and Leibniz algebras over a field of
+characteristic 0, the formations of all nilpotent algebras and of all soluble
+algebras are the only locally defined formations and that the latter has many
+local definitions. Over a field of non-zero characteristic, a saturated
+formation of soluble Lie algebras has at most one local definition but a
+locally defined saturated formation of soluble Leibniz algebras other than that
+of nilpotent algebras has more than one local definition.",1110.5009v1
+2011-11-25,Low-loss flake-graphene saturable absorber mirror for laser mode-locking at sub-200-fs pulse duration,"Saturable absorbers are a key component for mode-locking femtosecond lasers.
+Polymer films containing graphene flakes have recently been used in
+transmission as laser mode-lockers, but suffer from high nonsaturable loss,
+limiting their application in low-gain lasers. Here we present a saturable
+absorber mirror based on a film of pure graphene flakes. The device is used to
+mode lock an erbium-doped fiber laser, generating pulses with state-of-the-art,
+sub-200-fs duration. The laser characteristic indicate that the film exhibits
+low nonsaturable loss (13% per pass) and large absorption modulation depth (45%
+of low-power absorption).",1111.6011v1
+2012-01-02,Quantum uncertainty relation saturated by the eigenstates of the harmonic oscillator,"We re-derive the Schr\""{o}dinger-Robertson uncertainty principle for the
+position and momentum of a quantum particle. Our derivation does not directly
+employ commutation relations, but works by reduction to an eigenvalue problem
+related to the harmonic oscillator, which can then be further exploited to find
+a larger class of constrained uncertainty relations. We derive an uncertainty
+relation under the constraint of a fixed degree of Gaussianity and prove that,
+remarkably, it is saturated by all eigenstates of the harmonic oscillator. This
+goes beyond the common knowledge that the (Gaussian) ground state of the
+harmonic oscillator saturates the uncertainty relation.",1201.0453v2
+2012-03-16,Nonlinear dynamics of beta induced Alfvén eigenmode driven by energetic particles,"Nonlinear saturation of beta induced Alfv\'en eigenmode, driven by slowing
+down energetic particles via transit resonance, is investigated by the
+nonlinear hybrid magnetohyrodynamic gyro-kinetic code (XHMGC). Saturation is
+characterized by frequency chirping and symmetry breaking between co- and
+counter-passing particles, which can be understood as the the evidence of
+resonance-detuning. The scaling of the saturation amplitude with the growth
+rate is also demonstrated to be consistent with radial resonance detuning due
+to the radial non-uniformity and mode structure.",1203.3769v1
+2012-09-07,Higher-order Kerr effect and harmonic cascading in gases,"The higher-order Kerr effect (HOKE) has been recently advocated to explain
+measurements of the saturation of the nonlinear refractive index in gases. Here
+we show that cascaded third-harmonic generation results in an effective fifth
+order nonlinearity that is negative and significant. Higher-order harmonic
+cascading will also occur from the HOKE, and the cascading contributions may
+significantly modify the observed nonlinear index change. At lower wavelengths
+cascading increases the HOKE saturation intensity, while for longer wavelengths
+cascading will decrease the HOKE saturation intensity.",1209.1487v3
+2013-01-14,Multipacting Analysis in Micro-pulse Electron Gun Design,"Modeling multipacting to steady state saturation is of interest in
+determining the performance of micro-pulse electron gun. In this paper, a novel
+method is proposed to calculate the multipacting resonance parameters for the
+gun. This method works well, and the 2-D simulation results suggest that steady
+state saturation can be achieved in the gun. After saturation the transition
+from two-surface multipacting to single-surface multipacting is occurred, and
+an extensive range of electrons emission time is a suggested way to avoid this
+kind of transition.",1301.2854v1
+2013-01-22,Saturation of gluon density and soft p-p collisions at LHC,"We calculate the unintegrated gluon distribution at low intrinsic transverse
+momenta and its parameters are found from the best description of the SPS and
+LHC data on the $pp$ collision in the soft kinematical region. It allows us to
+study the saturation of the gluon density at low $Q^2$ more carefully and find
+the saturation scale.",1301.5156v1
+2013-03-15,Nuclear symmetry energy from the Fermi-energy difference in nuclei,"The neutron-proton Fermi-energy difference and the correlation to nucleon
+separation energies for some magic nuclei are investigated with the Skyrme
+energy density functionals and nuclear masses, with which the nuclear symmetry
+energy at sub-saturation densities is constrained from 54 Skyrme parameter
+sets. The extracted nuclear symmetry energy at sub-saturation density of 0.11
+fm$^{-3}$ is 26.2 $\pm$ 1.0 MeV with 1.5 $\sigma$ uncertainty. By further
+combining the neutron-skin thickness of 208Pb, ten Skyrme forces with slope
+parameter of 28<L<65 are selected for the description of the symmetry energy
+around saturation densities.",1303.3659v1
+2013-04-03,Increased mode instability thresholds of fiber amplifiers by gain saturation,"We show by numerical modeling that saturation of the population inversion
+reduces the stimulated thermal Rayleigh gain relative to the laser gain in
+large mode area fiber amplifiers. We show how to exploit this effect to raise
+mode instability thresholds by a substantial factor. We also demonstrate that
+when suppression of stimulated Brillouin scattering and the population
+saturation effect are both taken into account, counter-pumped amplifiers have
+higher mode instability thresholds than co-pumped amplifiers for fully
+Yb$^{3+}$ doped cores, and confined doping can further raise the thresholds.",1304.1064v1
+2014-01-20,Gluon saturation and initial conditions for relativistic heavy ion collisions,"We present an overview of theoretical aspects of the phenomenon of gluon
+saturation in high energy scattering in Quantum Chromo Dynamics. Then we review
+the state-of-the-art of saturation-based phenomenological approaches to the
+study and characterisation of the initial state of ultra-relativistic heavy ion
+collisions performed at RHIC and the LHC. Our review focuses mostly in the
+Color Glass Condensate effective theory, although we shall also discuss other
+approaches in parallel.",1401.4866v1
+2014-01-26,Hadron Multiplicities in p+p and p+Pb Collisions,"Experiments at the Large Hadron Collider (LHC) have measured multiplicity
+distributions in p+p and p+Pb collisions at a new domain of collision energy.
+Based on considering an energy-dependent broadening of the nucleon's density
+distribution, charged hadron multiplicities are studied with the
+phenomenological saturation model and the evolution equation dependent
+saturation model. By assuming the saturation scale have a small dependence on
+the 3-dimensional root mean square (rms) radius at different energy, the
+theoretical results are in good agreement with the experimental data from CMS
+and ALICE collaboration. Then, the predictive results in p+p collisions at
+$\sqrt{s}=$ 14 TeV of the LHC are also given.",1401.6625v1
+2014-02-20,Cluster-liquid transition in finite saturated fermionic systems,"The role of saturation for cluster formation in finite systems such as atomic
+nuclei is analyzed by considering three length-scale ratios, and performing
+deformation-constrained self-consistent mean-field calculations. The effect of
+clusterisation in deformed light systems is related to the saturation property
+of the inter-nucleon interaction. The formation of clusters at low nucleon
+density is illustrated by expanding the radius of $^{16}$O. A phase diagram
+shows that the formation of clusters can be interpreted as a hybrid state
+between the crystal and the liquid phases. In the hybrid cluster phase the
+confining potential attenuates the delocalization generated by the effective
+nuclear interaction.",1402.5080v2
+2014-07-28,A Systematic Approach to the Reconstruction of Saturated SDO/AIA Images,"EUV images of solar flares provided by the Atmospheric Imaging Assembly
+onboard the Solar Dynamics Observatory (SDO/AIA) are often affected by
+saturation effects in their core, physically most interesting region. We
+introduce an image reconstruction procedure that allows recovering information
+in the primary saturation domain using the secondary images produced by the
+diffraction fringes as input data. Such a procedure is based on standard
+image-processing tools like correlation, convolution, and back-projection. Its
+effectiveness is tested in the case of SDO/AIA observations of the July 8 2013
+flaring event.",1407.7343v1
+2014-09-18,Saturation of the leading spike growth in backward Raman amplifiers,"Backward Raman amplification of laser pulses in plasmas can produce nearly
+relativistic unfocused output intensities and multi-exawatt powers in compact
+devices. The largest achievable intensity depends on which of major competitive
+processes sets this limit. It is shown here that the relativistic electron
+nonlinearity can cause saturation of the leading amplified spike intensity
+before filamentation instabilities develop. A simple analytical model for the
+saturation, which supports numerical simulations, is suggested. The upper limit
+for the leading output spike unfocused intensity is calculated.",1409.5195v1
+2014-09-18,Exceeding the leading spike intensity and fluence limits in backward Raman amplifiers,"The leading amplified spike in backward Raman amplifiers can reach nearly
+relativistic intensities before the saturation by the relativistic electron
+nonlinearity, which sets an upper limit to the largest achievable leading spike
+intensity. It is shown here that this limit can be substantially exceeded by
+the initially sub-dominant spikes, which surprisingly outgrow the leading spike
+after its nonlinear saturation. Furthermore, an initially negligible group
+velocity of the amplified pulse in strongly under-critical plasma appears to be
+capable of delaying the filamentation instability in the nonlinear saturation
+regime. This enables further amplification of the pulse to even larger output
+fluences.",1409.5407v1
+2014-10-28,Brief Review of Saturation Physics,"We present a short overview of saturation physics followed by a summary of
+the recent progress in our understanding of nonlinear small-$x$ evolution.
+Topics include McLerran-Venugopalan model, Glauber-Mueller approximation,
+nonlinear BK/JIMWLK evolution equations, along with the running-coupling and
+NLO corrections to these equations. We conclude with selected topics in
+saturation phenomenology.",1410.7722v1
+2014-11-06,Domain of attraction of saturated switched systems under dwell-time switching,"This paper considers discrete-time switched systems under dwell-time
+switching and in the presence of saturation nonlinearity. Based on Multiple
+Lyapunov Functions and using polytopic representation of nested saturation
+functions, a sufficient condition for asymptotic stability of such systems is
+derived. It is shown that this condition is equivalent to linear matrix
+inequalities (LMIs) and as a result, the estimation of domain of attraction is
+formulated into a convex optimization problem with LMI constraints. Through
+numerical examples, it is shown that the proposed approach is less conservative
+than the others in terms of both minimal dwell-time needed for stability and
+the size of the obtained domain of attraction.",1411.1486v1
+2015-01-05,Statistical properties of the radiation from SASE FEL operating in a post-saturation regime with and without undulator tapering,"We describe statistical and coherence properties of the radiation from x-ray
+free electron lasers (XFEL) operating in the post-saturation regime. We
+consider practical case of the SASE3 FEL at the European XFEL. We perform
+comparison of the main characteristics of the X-ray FEL operating in the
+post-saturation regime with and without undulator tapering: efficiency,
+coherence time and degree of transverse coherence.",1501.00899v1
+2015-03-08,DESAT: an SSW tool for SDO/AIA image de-saturation,"Saturation affects a significant rate of images recorded by the Atmospheric
+Imaging Assembly on the Solar Dynamics Observatory. This paper describes a
+computational method and a technological pipeline for the de-saturation of such
+images, based on several mathematical ingredients like Expectation
+Maximization, image correlation and interpolation. An analysis of the
+computational properties and demands of the pipeline, together with an
+assessment of its reliability are performed against a set of data recorded from
+the Feburary 25 2014 flaring event.",1503.02302v1
+2015-03-19,Terahertz nonlinear conduction and absorption saturation in silicon waveguides,"We employ a silicon dielectric waveguide to confine and concentrate terahertz
+pulses, and observe that the absorption saturates under strong terahertz
+fields. By comparing the response between lightly-doped and intrinsic silicon
+waveguides, we confirm the role of hot carriers in this saturable absorption.
+We introduce a nonlinear dynamical model of Drude conductivity that, when
+incorporated into a wave propagation equation, accurately reproduces the
+observations and elucidates the physical mechanisms underlying this nonlinear
+effect. The results are numerically confirmed by Monte Carlo simulations of the
+Boltzmann transport equation, coupled with split-step nonlinear wave
+propagation.",1503.05639v1
+2015-05-18,Model Independent Description of Amplification and Saturation Using Green's Function,"High-gain Free Electron Laser (FEL) is one of the many electron-beam
+instabilities that have a number of common features linking the shot noise, the
+amplification and the saturation. In this paper, we present a new,
+model-independent description of the interplay between these effects. We derive
+a simple formula for a maximum attainable gain before instability saturates.
+Application of this model-independent formula to FELs is compared with FEL
+theory and simulations. We apply the limitations resulting from these findings
+to FEL amplifiers used for seeded FELs and for Coherent electron Cooling.",1505.04735v1
+2015-09-04,Stabilization of a linear Korteweg-de Vries equation with a saturated internal control,"This article deals with the design of saturated controls in the context of
+partial differential equations. It is focused on a linear Korteweg-de Vries
+equation, which is a mathematical model of waves on shallow water surfaces. In
+this article, we close the loop with a saturating input that renders the
+equation nonlinear. The well-posedness is proven thanks to the nonlinear
+semigroup theory. The proof of the asymptotic stability of the closed-loop
+system uses a Lyapunov function.",1509.01471v1
+2015-10-05,Describing the response of saturated SiPMs,"We have developed a function which describes SiPM response in both small
+signal and highly saturated regimes. The function includes the reactivation of
+SiPM pixels during a single input light pulse, and results in an approximately
+linear increase of SiPM response in the highly saturated regime, as observed in
+real SiPMs. This article shows that the function can accurately describe the
+measured response of real SiPM devices over a wide range of signal intensities.",1510.01102v4
+2016-01-19,Atomic saturation of reduced powers,"Our aim was to generalize some theorems about the saturation of ultra-powers
+to reduced powers. Naturally, we deal via saturation for types consisting of
+atomic formulas. We succeed to generalize the theory of dense linear is maximal
+and so is any pair (T, Delta) which is SOP_3 (Delta consists of atomic or
+conjunction of atomic formulas). However, SOP_2 is not enough, so the p equals
+t theorem cannot be generalized in this case. Similarly the unique dual of
+cofinality.",1601.04824v3
+2016-01-21,Beyond nonlinear saturation of backward Raman amplifiers,"Backward Raman amplification is limited by relativistic nonlinear dephasing
+resulting in saturation of the leading spike of the amplified pulse. Pump
+detuning is employed to mitigate the relativistic phase mismatch and to
+overcome the associated saturation. The amplified pulse can then be reshaped
+into a mono-spike pulse with little precursory power ahead of it, with the
+maximum intensity increasing by a factor of two. This detuning can be employed
+advantageously both in regimes where the group velocity dispersion is
+unimportant and where the dispersion is important but small.",1601.05832v1
+2016-04-14,Effects of flake size on mode-locking behavior for flake-graphene saturable absorber mirrors,"After advent of graphene as a saturable absorber many experiments have been
+conducted to produce short pulse duration pulses. Here, we have measured the
+properties of flake-graphene saturable absorber mirrors of various flake sizes
+dependent on fabrication technique. These mirrors enabled us to obtain a large
+mode-locking bandwidth of 16nm in an erbium-doped fiber laser. Mirrors with
+large flake size and multi-layered thickness induce strong pulse shaping and
+reflect mode-locked train of pulses with very large bandwidths.",1604.04113v1
+2016-07-05,Optimal waiting time bounds for some flux-saturated diffusion equations,"We consider the Cauchy problem for two prototypes of flux-saturated diffusion
+equations. In arbitrary space dimension, we give an optimal condition on the
+growth of the initial datum which discriminates between occurrence or
+nonoccurrence of a waiting time phenomenon. We also prove optimal upper bounds
+on the waiting time. Our argument is based on the introduction of suitable
+families of subsolutions and on a comparison result for a general class of
+flux-saturated diffusion equations.",1607.01245v3
+2016-07-22,Scaling properties of the number of random sequential adsorption iterations needed to generate saturated random packing,"The properties of the number of iterations in random sequential adsorption
+protocol needed to generate finite saturated random packing of spherically
+symmetric shapes were studied. Numerical results obtained for one, two, and
+three dimensional packings were supported by analytical calculations valid for
+any dimension $d$. It has been shown that the number of iterations needed to
+generate finite saturated packing is subject to Pareto distribution with
+exponent $-1-1/d$ and the median of this distribution scales with packing size
+according to the power-law characterized by exponent $d$. Obtained resultscan
+be used in designing effective RSA simulations.",1607.06668v2
+2016-08-08,Saturation in inclusive production beyond leading logarithm accuracy,"We review recent progress on the calculations on the inclusive forward hadron
+production within the saturation formalism. After introducing the concept of
+perturbative parton saturation and nonlinear evolution we discuss the formalism
+for the forward hadron production at high energy in the leading and
+next-to-leading order. Numerical results are presented and compared with the
+experimental data on forward hadron production in $dA$ and $pA$. We discuss the
+problem of the negativity of the NLO cross section at high transverse momenta,
+study its origin in detail and present possible improvements which include the
+corrected kinematics and the suitable choice of the rapidity cutoff.",1608.02285v1
+2016-09-19,Global stabilization of a Korteweg-de Vries equation with saturating distributed control,"This article deals with the design of saturated controls in the context of
+partial differential equations. It focuses on a Korteweg-de Vries equation,
+which is a nonlinear mathematical model of waves on shallow water surfaces. Two
+different types of saturated controls are considered. The well-posedness is
+proven applying a Banach fixed point theorem, using some estimates of this
+equation and some properties of the saturation function. The proof of the
+asymptotic stability of the closed-loop system is separated in two cases: i)
+when the control acts on all the domain, a Lyapunov function together with a
+sector condition describing the saturating input is used to conclude on the
+stability, ii) when the control is localized, we argue by contradiction. Some
+numerical simulations illustrate the stability of the closed-loop nonlinear
+partial differential equation. 1. Introduction. In recent decades, a great
+effort has been made to take into account input saturations in control designs
+(see e.g [39], [15] or more recently [17]). In most applications, actuators are
+limited due to some physical constraints and the control input has to be
+bounded. Neglecting the amplitude actuator limitation can be source of
+undesirable and catastrophic behaviors for the closed-loop system. The standard
+method to analyze the stability with such nonlinear controls follows a two
+steps design. First the design is carried out without taking into account the
+saturation. In a second step, a nonlinear analysis of the closed-loop system is
+made when adding the saturation. In this way, we often get local stabilization
+results. Tackling this particular nonlinearity in the case of finite
+dimensional systems is already a difficult problem. However, nowadays, numerous
+techniques are available (see e.g. [39, 41, 37]) and such systems can be
+analyzed with an appropriate Lyapunov function and a sector condition of the
+saturation map, as introduced in [39]. In the literature, there are few papers
+studying this topic in the infinite dimensional case. Among them, we can cite
+[18], [29], where a wave equation equipped with a saturated distributed
+actuator is studied, and [12], where a coupled PDE/ODE system modeling a
+switched power converter with a transmission line is considered. Due to some
+restrictions on the system, a saturated feedback has to be designed in the
+latter paper. There exist also some papers using the nonlinear semigroup theory
+and focusing on abstract systems ([20],[34],[36]). Let us note that in [36],
+[34] and [20], the study of a priori bounded controller is tackled using
+abstract nonlinear theory. To be more specific, for bounded ([36],[34]) and
+unbounded ([34]) control operators, some conditions are derived to deduce, from
+the asymptotic stability of an infinite-dimensional linear system in abstract
+form, the asymptotic stability when closing the loop with saturating
+controller. These articles use the nonlinear semigroup theory (see e.g. [24] or
+[1]). The Korteweg-de Vries equation (KdV for short)",1609.05728v1
+2016-11-08,Saturation and geometrical scaling,"We discuss emergence of geometrical scaling as a consequence of the nonlinear
+evolution equations of QCD, which generate a new dynamical scale, known as the
+saturation momentum: Qs. In the kinematical region where no other energy scales
+exist, particle spectra exhibit geometrical scaling (GS), i.e. they depend on
+the ratio pT=Qs, and the energy dependence enters solely through the energy
+dependence of the saturation momentum. We confront the hypothesis of GS in
+different systems with experimental data.",1611.02436v1
+2016-12-09,Compact foliations with finite transverse LS category,"We prove that if F is a foliation of a compact manifold M with all leaves
+compact submanifolds, and the transverse saturated category of F is finite,
+then the leaf space M/F is compact Hausdorff. The proof is surprisingly
+delicate, and is based on some new observations about the geometry of compact
+foliations. Colman proved in her 1998 doctoral thesis that the transverse
+saturated category of a compact Hausdorff foliation is always finite, so we
+obtain a new characterization of the compact Hausdorff foliations among the
+compact foliations as those with finite transverse saturated category.",1612.03022v1
+2017-01-05,Saturating sets in projective planes and hypergraph covers,"Let $\Pi_q$ be an arbitrary finite projective plane of order $q$. A subset
+$S$ of its points is called saturating if any point outside $S$ is collinear
+with a pair of points from $S$. Applying probabilistic tools we improve the
+upper bound on the smallest possible size of the saturating set to
+$\lceil\sqrt{3q\ln{q}}\rceil+ \lceil(\sqrt{q}+1)/2\rceil$. The same result is
+presented using an algorithmic approach as well, which points out the
+connection with the transversal number of uniform multiple intersecting
+hypergraphs.",1701.01379v2
+2017-04-05,"Comment on ""Biologically inspired protection of deep networks from adversarial attacks""","A recent paper suggests that Deep Neural Networks can be protected from
+gradient-based adversarial perturbations by driving the network activations
+into a highly saturated regime. Here we analyse such saturated networks and
+show that the attacks fail due to numerical limitations in the gradient
+computations. A simple stabilisation of the gradient estimates enables
+successful and efficient attacks. Thus, it has yet to be shown that the
+robustness observed in highly saturated networks is not simply due to numerical
+limitations.",1704.01547v1
+2017-07-04,Elimination via saturation,"This short paper presents saturation-based algorithms for homogenization and
+elimination. This algorithm can compute elimination ideals by using syzygies
+and ideal membership test, hence it works with any} monomial order, in
+particular without the use of block-elimination orders. The used saturation is
+a translation of the geometric fact that the projective closure of an affine
+scheme has no components in the hyperplane at infinity.",1707.00925v3
+2017-08-22,Multi-TeV Energy Resolution Studies with VERITAS,"This work aims to investigate the systematic uncertainty in gamma-ray spectra
+arising from saturation effects from bright images reconstructed by VERITAS.
+The goal of the work is to improve or validate the energy resolution used for
+deriving gamma-ray spectra in the sub-TeV to multi-TeV energy regime with
+VERITAS. Saturation from multi-TeV gamma-ray events affects the image
+brightness used to reconstruct the energy of the primary gamma ray, and
+potentially biases the energy estimate. We discuss a method for investigating
+the energy resolution bias in these multi-TeV gamma-ray events by looking at
+showers with large core distances that do not saturate the cameras.",1708.06728v1
+2017-09-06,Enriched Galerkin methods for two-phase flow in porous media with capillary pressure,"In this paper, we propose an enriched Galerkin (EG) approximation for a
+two-phase pressure saturation system with capillary pressure in heterogeneous
+porous media. The EG methods are locally conservative, have fewer degrees of
+freedom compared to discontinuous Galerkin (DG), and have an efficient pressure
+solver. To avoid non-physical oscillations, an entropy viscosity stabilization
+method is employed for high order saturation approximations. Entropy residuals
+are applied for dynamic mesh adaptivity to reduce the computational cost for
+larger computational domains. The iterative and sequential IMplicit Pressure
+and Explicit Saturation (IMPES) algorithms are treated in time. Numerical
+examples with different relative permeabilities and capillary pressures are
+included to verify and to demonstrate the capabilities of EG.",1709.01644v1
+2017-09-12,Decomposition method related to saturated hyperball packings,"In this paper we study the problem of hyperball (hypersphere) packings in
+$3$-dimensional hyperbolic space. We introduce a new definition of the
+non-compact saturated ball packings and describe to each saturated hyperball
+packing, a new procedure to get a decomposition of 3-dimensional hyperbolic
+space $\HYP$ into truncated tetrahedra. Therefore, in order to get a density
+upper bound for hyperball packings, it is sufficient to determine the density
+upper bound of hyperball packings in truncated simplices.",1709.04369v1
+2017-09-22,Superconducting single-photon detectors with saturated dependence of quantum efficiency vs. bias current,"It was investigated the possibility of creating NbN superconducting
+single-photon detectors with saturated dependence of quantum efficiency versus
+normalized bias current. It was shown that the saturation increases for the
+detectors based on finer films with a lower value of Rs300/Rs20. The decreasing
+of Rs300/Rs20 related to increasing influence of quantum corrections to
+conductivity of superconductors and, in its turn, to decreasing electron
+diffusion coefficient. The best samples has constant value of system quantum
+effi-ciency 94% at Ib/Ic~0.8 and wavelength 1.31 mkm.",1709.07686v2
+2017-11-03,Rainbow saturation and graph capacities,"The $t$-colored rainbow saturation number $rsat_t(n,F)$ is the minimum size
+of a $t$-edge-colored graph on $n$ vertices that contains no rainbow copy of
+$F$, but the addition of any missing edge in any color creates such a rainbow
+copy. Barrus, Ferrara, Vandenbussche and Wenger conjectured that $rsat_t(n,K_s)
+= \Theta(n\log n)$ for every $s\ge 3$ and $t\ge \binom{s}{2}$. In this short
+note we prove the conjecture in a strong sense, asymptotically determining the
+rainbow saturation number for triangles. Our lower bound is probabilistic in
+spirit, the upper bound is based on the Shannon capacity of a certain family of
+cliques.",1711.01047v2
+2017-11-07,"Saturation of Jacobian ideals: some applications to nearly free curves, line arrangements and rational cuspidal plane curves","In this note we describe the minimal resolution of the ideal $I_f$, the
+saturation of the Jacobian ideal of a nearly free plane curve $C:f=0$. In
+particular, it follows that this ideal $I_f$ can be generated by at most 4
+polynomials. Related general results by Hassanzadeh and Simis on the saturation
+of codimension 2 ideals are discussed in detail. Some applications to rational
+cuspidal plane curves and to line arrangements are also given.",1711.02595v3
+2017-11-30,Saturation model of DIS : an update,"We present the results of new fits to the recently extracted data on $F_2$ at
+low $x$ with the GBW saturation model and its modification to cover high values
+of $Q^2$. We find that the model stands the test of time and gives a good
+description of the data with slightly modified parameters. All the essential
+elements of the model, especially the saturation scale, are retained.",1711.11360v3
+2017-12-17,CGC/saturation approach: soft interaction at the LHC energies,"In this paper we demonstrate that our model which is based on the
+CGC/saturation approach, is able to describe the soft interaction collisions
+including the new TOTEM prelimenary data at 13 TeV. We believe that this
+strengthens the argument that the CGC/saturation approach is the only viable
+candidate for an effective theory for high energy QCD.",1712.06992v1
+2018-04-11,"Saturation in regular, exotic and random pore networks","Porcolation simulations were carried out on various networks; both regular
+and irregular. The saturation curve was obtained for cubic networks, localized
+and completely random 3D networks and networks based on exotic graphs like
+Sierpi\'nski triangle and carpet. For the random graph generation a
+modification of the cell list algorithm was introduced, which is capable of
+generating local random graphs efficiently. With the help of this graph
+generation method, the effect of locality was investigated, and it was proven
+to be an important property of random networks from the viewpoint of liquid
+propagation. The saturation curves of local random networks with different
+prescribed pore degree distributions were also obtained.",1804.03944v1
+2018-07-02,Resumming subleading Sudakov logarithms in saturation regime,"We investigate the scale dependence of transverse momentum dependent(TMD)
+gluon distribution in saturation regime. We found that in the Collins-2011
+scheme, the scale dependence of small x gluon TMD is governed by the same
+renormalization group(RG) equation that holds at moderate or large $x$.
+Following the standard procedure, one then can resum both double leading
+logarithm and single leading logarithm in saturation regime by jointly solving
+the Collins-Soper equation and the RG equation.",1807.00506v1
+2018-10-10,Approximate controllability for Navier--Stokes equations in {\rm 3D} Cylinders under Lions boundary conditions by an explicit saturating set,"An explicit saturating set consisting of eigenfunctions of Stokes operator in
+general 3D Cylinders is proposed. The existence of saturating sets implies the
+approximate controllability for Navier--Stokes equations in $\rm 3D$ Cylinders
+under Lions boundary conditions.",1810.04799v3
+2018-10-12,Nonlinear saturation of toroidal Alfven eigenmodes via nonlinear mode couplings,"Gyrokinetic theory of nonlinear mode coupling as a mechanism for toroidal
+Alfven eigenmode (TAE) saturation in the fusion plasma related parameter regime
+is presented, including 1) para- metric decay of TAE into lower kinetic TAE
+(LKTAE) and geodesic acoustic mode (GAM), and 2) enhanced TAE coupling to shear
+Alfven wave (SAW) continuum via ion induced scattering. Our theory shows that,
+for TAE saturation in the parameter range of practical interest, several
+processes with comparable scattering cross sections can be equally important.",1810.05300v1
+2018-10-23,Saturated Models in Mathematical Fuzzy Logic,"This paper considers the problem of building saturated models for first-order
+graded logics. We define types as pairs of sets of formulas in one free
+variable which express properties that an element is expected, respectively, to
+satisfy and to falsify. We show, by means of an elementary chains construction,
+that each model can be elementarily extended to a saturated model where as many
+types as possible are realized. In order to prove this theorem we obtain, as
+by-products, some results on tableaux (understood as pairs of sets of formulas)
+and their consistency and satisfiability, and a generalization of the
+Tarski--Vaught theorem on unions of elementary chains.",1810.09742v1
+2018-11-12,Effect of saturated absorption on sub-Poissonian lasing,"This paper discusses the effect of saturated absorption on the quantum
+features of a sub-Poissonian laser. It is shown that when both media (laser and
+absorbing) are saturated, the appearance of an additional element in the cavity
+does not lead to the demolition of the quantum properties (regular statistics
+of photons and quadrature squeezing) of laser radiation.",1811.04672v1
+2018-12-11,Saturation and alternate pathways in four-wave mixing in rubidium,"We have examined the frequency spectrum of the blue light generated via
+four-wave mixing in a rubidium vapor cell inside a ring cavity. At high atomic
+density and input laser power, two distinct frequency components separated by
+$116 \pm 4$ MHz are observed, indicating alternate four-wave mixing channels
+through the $6p_{3/2}$ hyperfine states. The dependence of the generated light
+on excitation intensity and atomic density are explored, and indicate the
+primary process has saturated. This saturation results when the excitation rate
+through the 6p state becomes equal to the rate through the 5p state, giving no
+further gain with atomic density while a quadratic intensity dependence
+remains.",1812.04465v1
+2019-01-16,Enhanced nonreciprocal transmission through a saturable cubic-quintic nonlinear dimer defect,"The transmission properties through a saturable cubic-quintic nonlinear
+defect attached to lateral linear chains is investigated. Particular attention
+is directed to the possible non-reciprocal diode-like transmission when the
+parity-symmetry of the defect is broken. Distinct cases of parity breaking are
+considered including asymmetric linear and nonlinear responses. The spectrum of
+the transmission coefficient is analytically computed and the influence of the
+degree of saturation analyzed in detail. The transmission of Gaussian
+wave-packets is also numerically investigated. Our results unveil that spectral
+regions with high transmission and enhanced diode-like operation can be
+achieved.",1901.05224v1
+2019-03-07,Left saturation closure for Ore localizations,"In this paper, we introduce the notion of LSat, the left saturation closure
+of a subset of a module at a subset of the base ring, which generalizes
+multiple important concepts related to Ore localization. We show its
+significance in finding a saturated normal form for left Ore sets as well as in
+characterizing the units of a localized ring.
+  Furthermore, LSat encompasses the notion of local closure of submodules and
+ideals from the realm of algebraic analysis, where it describes the result of
+extending a submodule or ideal from a ring to its localization and contracting
+it back again.",1903.03172v1
+2019-07-26,Local stabilization of an unstable parabolic equation via saturated controls,"We derive a saturated feedback control, which locally stabilizes a linear
+reaction-diffusion equation. In contrast to most other works on this topic, we
+do not assume the Lyapunov stability of the uncontrolled system and consider
+general unstable systems. Using Lyapunov methods, we provide estimates for the
+region of attraction for the closed-loop system, given in terms of linear and
+bilinear matrix inequalities. We show that our results can be used with
+distributed as well as scalar boundary control, and with different types of
+saturations. The efficiency of the proposed method is demonstrated by means of
+numerical simulations.",1907.11473v2
+2019-08-05,Nonlinear transmission of laser light through coronal plasma due to self-induced incoherence,"The success of direct laser-driven inertial confinement fusion (ICF) relies
+critically on the efficient coupling of laser light to plasma. At ignition
+scale, the absolute stimulated Raman scattering (SRS) instability can severely
+inhibit this coupling by redirecting and strongly depleting laser light. This
+Letter describes a new dynamic saturation regime of the absolute SRS
+instability. The saturation occurs when spatiotemporal fluctuations in the
+ion-acoustic density detune the instability resonance. The dynamic saturation
+mitigates the strong depletion of laser light and enhances its transmission
+through the instability region, explaining the coupling of laser light to ICF
+targets at higher plasma densities.",1908.01684v1
+2019-09-24,The saturation number of $\cb$-bounded stable monomial ideals and their powers,"Let $S=K[x_1,\ldots,x_n]$ be the polynomial ring in $n$ variables over a
+field $K$. In this paper, we compute the socle of $\cb$-bounded strongly stable
+ideals and determine that the saturation number of strongly stable ideals and
+of equigenerated $\cb$-bounded strongly stable ideals. We also provide explicit
+formulas for the saturation number $\sat(I)$ of Veronese type ideals $I$. Using
+this formula, we show that $\sat(I^k)$ is quasi-linear from the beginning and
+we determine the quasi-linear function explicitly.",1909.10663v1
+2019-10-02,Exploring origin of small x saturation in collinear approach,"A modification of the collinear evolution equations as an appropriate
+approach to improve the behavior of parton distribution functions in the region
+of small longitudinal momentum fractions, and to find more theoretical
+arguments to clarify the possible appearence of saturation regime is suggested.
+It is argued that parton diffusion in the rapidity space at large parton
+densities along the space-time evolution could result in the emergence of a
+natural saturation scale on which freezing actually occurs.",1910.00819v1
+2020-01-06,Remarks on input-to-state stability of collocated systems with saturated feedback,"We investigate input-to-state stability (ISS) of infinite-dimensional
+collocated control systems subject to saturated feedback. Here, the unsaturated
+closed loop is dissipative and uniformly globally asymptotically stable. Under
+an additional assumption on the linear system, we show ISS for the saturated
+one. We discuss the sharpness of the conditions in light of existing results in
+the literature.",2001.01636v3
+2020-01-13,Approximation smooth and sparse functions by deep neural networks without saturation,"Constructing neural networks for function approximation is a classical and
+longstanding topic in approximation theory. In this paper, we aim at
+constructing deep neural networks (deep nets for short) with three hidden
+layers to approximate smooth and sparse functions. In particular, we prove that
+the constructed deep nets can reach the optimal approximation rate in
+approximating both smooth and sparse functions with controllable magnitude of
+free parameters. Since the saturation that describes the bottleneck of
+approximate is an insurmountable problem of constructive neural networks, we
+also prove that deepening the neural network with only one more hidden layer
+can avoid the saturation. The obtained results underlie advantages of deep nets
+and provide theoretical explanations for deep learning.",2001.04114v1
+2020-03-12,Optimal nonlinear damping control of second-order systems,"Novel nonlinear damping control is proposed for the second-order systems. The
+proportional output feedback is combined with the damping term which is
+quadratic to the output derivative and inverse to the set-point distance. The
+global stability, passivity property, and convergence time and accuracy are
+demonstrated. Also the control saturation case is explicitly analyzed. The
+suggested nonlinear damping is denoted as optimal since requiring no design
+additional parameters and ensuring a fast convergence, without transient
+overshoots for a non-saturated and one transient overshoot for a saturated
+control configuration.",2003.05670v3
+2020-03-19,The saturated prefilter monad,"This paper considers some extensions of the notion of filter to the
+quantale-valued context, including saturated prefilter, $\top$-filter and
+bounded saturated prefilter. The question is whether these constructions give
+rise to monads on the category of sets. It is shown that the answer depends on
+the structure of the quantale. Specifically, if the quantale is the unit
+interval equipped with a continuous t-norm, then these constructions give rise
+to monads if and only if the implication operator corresponding to that t-norm
+is continuous at each point off the diagonal.",2003.08610v2
+2020-03-20,Well-posedness of dispersion managed nonlinear Schrödinger equations,"We prove local and global well-posedness results for the Gabitov-Turitsyn or
+dispersion managed nonlinear Schr\""odinger equation with a large class of
+nonlinearities and arbitrary average dispersion on $L^2(\mathbb{R})$ and
+$H^1(\mathbb{R})$. Moreover, when the average dispersion is non-negative, we
+show that the set of ground states is orbitally stable. This covers the case of
+non-saturated and saturated nonlinear polarizations and yields, for saturated
+nonlinearities, the first proof of orbital stability.",2003.09076v3
+2020-07-07,Resistivity saturation in an electron-doped cuprate,"We report the observation of resistivity saturation in lightly doped ($x\sim
+0.10)$ as-grown samples of the electron-doped cuprate La$_{2-x}$Ce$_x$CuO$_4$
+(LCCO). The saturation occurs at resistivity values roughly consistent with the
+phenomenological Mott-Ioffe-Regel criterion once the low effective carrier
+density of these materials is included in the analysis. These results imply
+that, at least for light doping, the high-temperature metallic phase of these
+materials is not necessarily strange and may be understood as simply a
+low-density metal.",2007.03685v1
+2020-10-28,Self-sweeping ytterbium-doped fiber laser based on a fiber saturable absorber,"Generally speaking, the self-sweeping effect relies on the dynamical grating
+formed in a gain fiber. Here, the normal self-sweeping was generated in a
+pump-free ytterbium-doped fiber which serves as a fiber saturable absorber and
+is introduced to the laser cavity by a circulator in this experiment. The
+sweeping rate and the sweeping range alter as usual, both of which can be
+controlled by the pump power. Further, a new self-pulse signal is observed and
+discussed in this work, which shows the difference of the self-sweeping effects
+between active fiber and fiber saturable absorber.",2010.14818v1
+2021-04-13,Stabilisation of the complex double integrator by means of a saturated linear feedback,"Consider the saturated complex double integrator, i.e., the linear control
+system $\dot x=Ax+B\sigma(u)$, where $x\in\R^4$, $u\in\R$, $B\in\R^4$, the
+$4\times 4$ matrix $A$ is not diagolizable and admits a non zero purely
+imaginary eigenvalue of multiplicity two, the pair $(A,B)$ is controllable and
+$\sigma:\R\to\R$ is a saturation function. We prove that there exists a linear
+feedback $u=K^Tx$ such that the resulting closed loop system given by $\dot
+x=Ax+B\sigma(K^Tx)$ is globally asymptotically stable with respect to the
+origin.",2104.06302v1
+2021-06-11,Saturation Numbers for Linear Forests $P_6$ + $tP_2$,"A graph $G$ is $H$-saturated if it contains no $H$ as a subgraph, but does
+contain $H$ after the addition of any edge in the complement of $G$. The
+saturation number, $sat (n, H)$, is the minimum number of edges of a graph in
+the set of all $H$-saturated graphs with order $n$. In this paper, we determine
+the saturation number $sat (n, P_6 + tP_2)$ for $n \geq 10t/3 + 10$ and
+characterize the extremal graphs for $n >10t/3 + 20$.",2106.06466v2
+2021-07-06,Symbol Elimination for Parametric Second-Order Entailment Problems (with Applications to Problems in Wireless Network Theory),"We analyze possibilities of second-order quantifier elimination for formulae
+containing parameters -- constants or functions. For this, we use a constraint
+resolution calculus obtained from specializing the hierarchical superposition
+calculus. If saturation terminates, we analyze possibilities of obtaining
+weakest constraints on parameters which guarantee satisfiability. If the
+saturation does not terminate, we identify situations in which finite
+representations of infinite saturated sets exist. We identify situations in
+which entailment between formulae expressed using second-order quantification
+can be effectively checked. We illustrate the ideas on a series of examples
+from wireless network research.",2107.02333v1
+2021-08-09,The saturation number of $C_6$,"A graph $G$ is called $C_k$-saturated if $G$ is $C_k$-free but $G+e$ not for
+any $e\in E(\overline{G})$. The saturation number of $C_k$, denoted
+$sat(n,C_k)$, is the minimum number of edges in a $C_k$-saturated graph on $n$
+vertices. Finding the exact values of $sat(n,C_k)$ has been one of the most
+intriguing open problems in extremal graph theory. In this paper, we study the
+saturation number of $C_6$. We prove that ${4n}/{3}-2 \le sat(n,C_6) \le
+{(4n+1)}/{3}$ for $n\ge9$, which significantly improves the existing lower and
+upper bounds for $sat(n,C_6)$.",2108.03910v3
+2022-02-15,Saturation for the $3$-uniform loose $3$-cycle,"Let $F$ and $H$ be $k$-uniform hypergraphs. We say $H$ is $F$-saturated if
+$H$ does not contain a subgraph isomorphic to $F$, but $H+e$ does for any
+hyperedge $e\not\in E(H)$. The saturation number of $F$, denoted
+$\mathrm{sat}_k(n,F)$, is the minimum number of edges in a $F$-saturated
+$k$-uniform hypergraph $H$ on $n$ vertices. Let $C_3^{(3)}$ denote the
+$3$-uniform loose cycle on $3$ edges. In this work, we prove that
+  \[
+  \left(\frac{4}3+o(1)\right)n\leq \mathrm{sat}_3(n,C_3^{(3)})\leq
+\frac{3}2n+O(1).
+  \]
+  This is the first non-trivial result on the saturation number for a fixed
+short hypergraph cycle.",2202.07149v1
+2022-03-19,Sub-additive unstable topological pressure on saturated subsets,"In this paper, we continue our investigation on sub-additive pressures for
+$C^1$-smooth partially hyperbolic diffeomorphisms. Under the assumption of
+unstable almost product property, we show that the unstable Bowen topological
+pressure on the saturated set of a given non-empty compact connected set of
+invariant measures equals the infimum of the summation of unstable metric
+entropy and the corresponding \emph{Lyapunov exponent}, where the infimum is
+taken over all invariant measures inside the compact connected set above.
+Moreover, we also show that the unstable topological capacity pressure on the
+saturated sets above coincide with the unstable topological pressure of the
+whole system.",2203.10279v1
+2022-06-06,Every Finite Poset is Isomorphic to a Saturated Subset of the Spectrum of a Noetherian UFD,"We show that every finite poset is isomorphic to a saturated subset of the
+spectrum of a Noetherian unique factorization domain. In addition, we show that
+every finite poset is isomorphic to a saturated subset of the spectrum of a
+quasi-excellent domain.",2206.02867v2
+2022-12-26,Emergence of nuclear saturation within $Δ$--full chiral effective field theory,"Nuclear saturation is a key property of low-energy nuclear physics that
+depends on fine details of the nuclear interaction. Here we develop a unified
+statistical framework that uses realistic nuclear forces to link the
+theoretical modeling of finite nuclei and infinite nuclear matter. We construct
+fast and accurate emulators for nuclear-matter observables and employ an
+iterative history-matching approach to explore and reduce the enormous
+parameter domain of $\Delta$-full chiral interactions. We find that model
+calibration including \nuc{16}{O} observables gives saturation predictions that
+are more accurate and have a smaller variance than those that only use few-body
+data.",2212.13203v1
+2023-01-10,Supersolvable saturated matroids and chordal graphs,"A matroid is supersolvable if it has a maximal chain of flats each of which
+is modular. A matroid is saturated if every round flat is modular. In this
+article we present supersolvable saturated matroids as analogues to chordal
+graphs, and we show that several results for chordal graphs hold in this
+matroid context. In particular, we consider matroid analogues of the reduced
+clique graph and clique trees for chordal graphs. The latter is a
+maximum-weight spanning tree of the former. We also show that the matroid
+analogue of a clique tree is an optimal decomposition for the matroid parameter
+of tree-width.",2301.03776v2
+2023-02-02,Nonlinear Regge trajectories and saturation of the Hagedorn spectrum,"We argue that two seemingly different phenomena, namely the well-known
+saturation of the Hagedorn exponential distribution and the less familiar
+saturation of Regge trajectories at resonance masses $m\approx$ 2-2.5 GeV are
+related and have the same origin: quark deconfinement. We show that the slope
+of the real part of non-linear Regge trajectories determines the prefactor
+$f(m)$ in Hagedorn's resonance mass density distribution $\rho(m)$. While the
+Hagedorn distribution comes from statistics, Regge trajectories contain
+dynamics.",2302.00838v1
+2023-05-08,Symbolic Model Construction for Saturated Constrained Horn Clauses,"Clause sets saturated by hierarchic ordered resolution do not offer a model
+representation that can be effectively queried, in general. They only offer the
+guarantee of the existence of a model. We present an effective symbolic model
+construction for saturated constrained Horn clauses. Constraints are in linear
+arithmetic, the first-order part is restricted to a function-free language. The
+model is constructed in finite time, and non-ground clauses can be effectively
+evaluated with respect to the model. Furthermore, we prove that our model
+construction produces the least model.",2305.05064v2
+2023-05-15,Criteria for supersolvability of saturated fusion systems,"Let $p$ be a prime number. A saturated fusion system $\mathcal{F}$ on a
+finite $p$-group $S$ is said to be supersolvable if there is a series $1 = S_0
+\le S_1 \le \dots \le S_m = S$ of subgroups of $S$ such that $S_i$ is strongly
+$\mathcal{F}$-closed for all $0 \le i \le m$ and such that $S_{i+1}/S_i$ is
+cyclic for all $0 \le i < m$. We prove some criteria that ensure that a
+saturated fusion system $\mathcal{F}$ on a finite $p$-group $S$ is
+supersolvable provided that certain subgroups of $S$ are abelian and weakly
+$\mathcal{F}$-closed. Our results can be regarded as generalizations of purely
+group-theoretic results of Asaad.",2305.09008v1
+2023-05-25,Power Counting to Saturation,"We present a description of saturation in small x deep inelastic scattering
+from power counting in a top-down effective theory derived from QCD. A
+factorization formula isolates the universal physics of the nucleus at leading
+power in x. The onset of saturation is then understood as a breakdown in the
+expansion in an emergent power counting parameter, which is defined by the
+matrix element of a gauge invariant operator. We demonstrate the presence of a
+novel collinear-soft radiation mode, which clarifies the role played by the
+medium size in deciding linear/non-linear evolution of the cross section in
+$\ln x$.",2305.16393v1
+2023-05-26,Nonlinear saturation of resistive tearing modes in a cylindrical tokamak with and without solving the dynamics,"We show that the saturation of resistive tearing modes in a cylindrical
+tokamak, as well as the corresponding island width, can be directly calculated
+with an MHD equilibrium code without solving the dynamics and without
+considering resistivity. The results are compared to initial value resistive
+MHD simulations and to an analytical nonlinear theory. For small enough
+islands, the agreement is remarkable. For sufficiently large islands, the
+equilibrium calculations, which assume a flat current profile inside the
+island, overestimate the saturation amplitude. On the other hand, excellent
+agreement between nonlinear resistive MHD simulations and nonlinear theory is
+observed for all the considered tearing unstable equilibria.",2305.16785v2
+2024-01-23,A new mathematical model for cell motility with nonlocal repulsion from saturated areas,"The main purpose of this work is the modelling of large populations of cells
+under different interactions among themselves, in balance with natural random
+diffusion. We focus on cell-cell adhesion mechanisms for one single population
+confined in isolated domains. Our most relevant contribution is the proposal of
+a mathematical model, that includes a nonlocal saturation coefficient
+multiplying an appropriate nonlocal drift term, that can even induce repulsion
+effects from saturated areas.",2401.13117v1
+2024-01-27,Effects of non-condensable gas on laser-induced cavitation bubbles,"This study presents experimental observations of single laser-induced
+cavitation bubbles collapsing in water with different levels of air saturation.
+The average trends of the bubble size reveal a clear yet little dependence of
+the energy dissipation at collapse on the water gas content. Similarly, the
+observed trend of luminescence energy at collapse varies within the
+investigated range of air saturation levels, in agreement with findings in
+similar works. We argue that perturbations in bubble shape may amplify with
+decreasing air saturation, consequently affecting light emission.",2401.15421v1
+2024-02-21,Overcoming Saturation in Density Ratio Estimation by Iterated Regularization,"Estimating the ratio of two probability densities from finitely many samples,
+is a central task in machine learning and statistics. In this work, we show
+that a large class of kernel methods for density ratio estimation suffers from
+error saturation, which prevents algorithms from achieving fast error
+convergence rates on highly regular learning problems. To resolve saturation,
+we introduce iterated regularization in density ratio estimation to achieve
+fast error rates. Our methods outperform its non-iteratively regularized
+versions on benchmarks for density ratio estimation as well as on large-scale
+evaluations for importance-weighted ensembling of deep unsupervised domain
+adaptation models.",2402.13891v1
+2007-05-20,Dependence of hillslope moisture content on downhill saturation,"We derive steady equilibria for lateral downslope moisture flow in an
+idealized thin closed layer as a solution to the 1D Richards' Equation. The
+equilibria are determined by two free parameters: the downslope flux and a
+boundary condition. Solutions exhibit a constant downslope flow speed and
+moisture content for the constant equilibrium flux, which is the product of the
+two. However where an isolated zone of fixed saturation degree exists
+representing a boundary condition, the flow speed immediately upslope is
+reduced and the moisture content correspondingly increased to preserve the
+constant equilibrium flux. The capillary head jump at the saturated zone
+produces a blockage that gives a high moisture content back upslope through a
+pooling distance determined by the equilibrium condition that the downslope
+flux is constant. In our numerical integrations, the vertically projected
+pooling height is more than 10 km for a fully saturated zone in mixed silty or
+clay soils, but decreases by about an order of magnitude with every 10%
+decrease in the boundary-zone saturation degree. The drying of downhill
+saturated zones with the increased speed of mountain moisture outflow and
+corresponding decreased mountain moisture content gives a viable explanation
+for the mysterious ~69% unaccounted drop seen in the spring outflow in the La
+Luz / Fresnal Watershed at Alamogordo's upstream spring-box diversions in the
+semiarid southeastern New Mexico USA.",0705.2840v2
+2009-01-02,Existence of an upper limit on the density of excitons in carbon nanotubes by diffusion-limited exciton-exciton annihilation: Experiment and theory,"Through an investigation of photoemission properties of highly-photoexcited
+single-walled carbon nanotubes, we demonstrate that there is an upper limit on
+the achievable excitonic density. As the intensity of optical excitation
+increases, all photoluminescence emission peaks arising from different
+chirality single-walled carbon nanotubes showed clear saturation in intensity.
+Each peak exhibited a saturation value that was independent of the excitation
+wavelength, indicating that there is an upper limit on the excitonic density
+for each nanotube species. We propose that this saturation behavior is a result
+of efficient exciton-exciton annihilation through which excitons decay
+non-radiatively. In order to explain the experimental results and obtain
+excitonic densities in the saturation regime, we have developed a model, taking
+into account the generation, diffusion-limited exciton-exciton annihilation,
+and spontaneous decays of one-dimensional excitons. Using the model, we were
+able to reproduce the experimentally obtained saturation curves under certain
+approximations, from which the excitonic densities were estimated. The validity
+of the model was confirmed through comparison with Monte Carlo simulations.
+Finally, we show that the conventional rate equation for exciton-exciton
+annihilation without taking into account exciton diffusion fails to fit the
+experimentally observed saturation behavior, especially at high excitonic
+densities.",0901.0211v1
+2009-03-31,Stroke saturation on a MEMS deformable mirror for woofer-tweeter adaptive optics,"High-contrast imaging of extrasolar planet candidates around a main-sequence
+star has recently been realized from the ground using current adaptive optics
+(AO) systems. Advancing such observations will be a task for the Gemini Planet
+Imager, an upcoming ""extreme"" AO instrument. High-order ""tweeter"" and low-order
+""woofer"" deformable mirrors (DMs) will supply a >90%-Strehl correction, a
+specialized coronagraph will suppress the stellar flux, and any planets can
+then be imaged in the ""dark hole"" region. Residual wavefront error scatters
+light into the DM-controlled dark hole, making planets difficult to image above
+the noise. It is crucial in this regard that the high-density tweeter, a
+micro-electrical mechanical systems (MEMS) DM, have sufficient stroke to deform
+to the shapes required by atmospheric turbulence. Laboratory experiments were
+conducted to determine the rate and circumstance of saturation, i.e. stroke
+insufficiency. A 1024-actuator 1.5-um-stroke MEMS device was empirically tested
+with software Kolmogorov-turbulence screens of r_0=10-15cm. The MEMS when
+solitary suffered saturation ~4% of the time. Simulating a woofer DM with ~5-10
+actuators across a 5-m primary mitigated MEMS saturation occurrence to a
+fraction of a percent. While no adjacent actuators were saturated at opposing
+positions, mid-to-high-spatial-frequency stroke did saturate more frequently
+than expected, implying that correlations through the influence functions are
+important. Analytical models underpredict the stroke requirements, so empirical
+studies are important.",0903.5355v1
+2009-08-25,Hadrons and direct photon in pp and pA collisions at LHC and saturation effects,"We investigate hadrons and direct photon production in pp and pA collisions
+at the energies of RHIC and LHC within the color-dipole approach employing
+various saturation models. We show that greatest sensitivity to saturation
+effects is reached at very forward rapidities for pp collisions at LHC
+(\sqrt{s}=14 TeV). The ratio of direct-photon to pion production can be about
+20-10 (at \eta=7-8). Therefore, direct photon production at forward rapidities
+should provide a rather clean probe. We calculate the rapidity dependence of
+the invariant cross-section and find some peculiar enhancement at forward
+rapidities which is more pronounced for direct photon production. We show that
+this peak is further enhanced by saturation effects. We provide predictions for
+the nuclear modification factor R_{pA} for pions and direct photon production
+in pA collisions at LHC energy at midrapidity. We show within various
+saturation models that the pion Cronin enhancement at RHIC is replaced by a
+moderate suppression at LHC energy at midrapidity due to gluon shadowing
+effects. Cronin enhancement of direct photons can survive at LHC energy within
+models with a larger saturation scale.",0908.3695v2
+2012-12-13,Analytical model for flux saturation in sediment transport,"The transport of sediment by a fluid along the surface is responsible for
+dune formation, dust entrainment and for a rich diversity of patterns on the
+bottom of oceans, rivers, and planetary surfaces. Most previous models of
+sediment transport have focused on the equilibrium (or saturated) particle
+flux. However, the morphodynamics of sediment landscapes emerging due to
+surface transport of sediment is controlled by situations out-of-equilibrium.
+In particular, it is controlled by the saturation length characterizing the
+distance it takes for the particle flux to reach a new equilibrium after a
+change in flow conditions. The saturation of mass density of particles
+entrained into transport and the relaxation of particle and fluid velocities
+constitute the main relevant relaxation mechanisms leading to saturation of the
+sediment flux. Here we present a theoretical model for sediment transport
+which, for the first time, accounts for both these relaxation mechanisms and
+for the different types of sediment entrainment prevailing under different
+environmental conditions. Our analytical treatment allows us to derive a closed
+expression for the saturation length of sediment flux, which is general and can
+thus be applied under different physical conditions.",1212.3052v5
+2014-02-20,Precise Algorithm to Generate Random Sequential Addition of Hard Hyperspheres at Saturation,"Random sequential addition (RSA) time-dependent packing process, in which
+congruent hard hyperspheres are randomly and sequentially placed into a system
+without interparticle overlap, is a useful packing model to study disorder in
+high dimensions. Of particular interest is the infinite-time {\it saturation}
+limit in which the available space for another sphere tends to zero. However,
+the associated saturation density has been determined in all previous
+investigations by extrapolating the density results for near-saturation
+configurations to the saturation limit, which necessarily introduces numerical
+uncertainties. We have refined an algorithm devised by us [S. Torquato, O.
+Uche, and F.~H. Stillinger, Phys. Rev. E {\bf 74}, 061308 (2006)] to generate
+RSA packings of identical hyperspheres. The improved algorithm produce such
+packings that are guaranteed to contain no available space using finite
+computational time with heretofore unattained precision and across the widest
+range of dimensions ($2 \le d \le 8$). We have also calculated the packing and
+covering densities, pair correlation function $g_2(r)$ and structure factor
+$S(k)$ of the saturated RSA configurations. As the space dimension increases,
+we find that pair correlations markedly diminish, consistent with a recently
+proposed ""decorrelation"" principle, and the degree of ""hyperuniformity""
+(suppression of infinite-wavelength density fluctuations) increases. We have
+also calculated the void exclusion probability in order to compute the
+so-called quantizer error of the RSA packings, which is related to the second
+moment of inertia of the average Voronoi cell. Our algorithm is easily
+generalizable to generate saturated RSA packings of nonspherical particles.",1402.4883v1
+2015-05-25,Modulation instability in high-order coupled nonlinear Schrödinger equations with saturable nonlinearities,"The influence of a saturable nonlinearity on the modulation instability in
+oppositely directed coupler in the presence of high-order effects is
+investigated. By using the standard linear stability analysis, we obtain the
+instability gain that exhibits a significant change in the bands of instability
+due to the effects of a saturable nonlinearity. We also show that even in the
+presence of saturation there is no change in instability gain when we compare
+the results obtained for both channels not influenced by self-steepening effect
+or for both channels influenced by self-steepening effect but opposite in sign.
+Regarding the Raman effect, there is reflection symmetry (asymmetry) to the
+gain at zero perturbation frequency when the values of the Raman coefficients
+in each directional coupler are equal and with same (opposite) sign. For the
+anomalous group velocity dispersion regime we observe that the growth of the
+saturation parameter is followed by an increase in the null gain region near
+{\Omega} = 0, enlarging the separation of the instability bands close to this
+point. Finally, we show that an efficient control of the modulation instability
+can be realized by adjusting self-steepening effect and intrapulse Raman
+scattering, even in the presence of a saturable nonlinearity.",1505.06719v1
+2015-12-21,A further update on possible crises in nuclear-matter theory,"The ancient problem of the saturation of symmetric nuclear matter is reviewed
+with an update on the status of the crises that were identified at an early
+stage by John Clark. We discuss how the initial problem with variational
+calculations providing more binding than the two hole-line contribution for the
+same interaction was overcome by calculations including three hole-line
+contributions without however reproducing the empirical nuclear saturation
+properties. It is argued that this remaining problem is still open because many
+solutions have been proposed or ad hoc adjustments implemented without
+generating universal agreement on the proper interpretation of the physics. The
+problem of nuclear saturation therefore persists leading to the necessity of an
+analysis of the way the nuclear saturation properties are obtained from
+experimental data. We clarify the role of short-range correlations and review
+results for nuclear saturation when such ingredients are completely taken into
+account using the Green's function method. The role of long-range correlations
+is then analyzed with special emphasis on the importance of attractive
+pion-dominated excitation modes which inevitably lead to higher saturation
+densities than observed. Because such modes have no counterpart in finite
+nuclear systems, it is therefore argued that they should not be considered when
+calculating nuclear matter properties. The remaining open question is then
+whether long-range correlations in finite nuclei which in turn have no
+counterpart in infinite matter, represent the remaining missing ingredient in
+this analysis.",1512.06793v1
+2019-05-13,Velocity Saturation in La-doped BaSnO3 Thin Films,"BaSnO_{3}, a high mobility perovskite oxide, is an attractive material for
+oxide-based electronic devices. However, in addition to low-field mobility,
+high-field transport properties such as the saturation velocity of carriers
+play a major role in determining device performance. We report on the
+experimental measurement of electron saturation velocity in La-doped BaSnO_{3}
+thin films for a range of doping densities. Predicted saturation velocities
+based on a simple LO-phonon emission model using an effective LO phonon energy
+of 120 meV show good agreement with measurements of velocity saturation in
+La-doped BaSnO_{3} films.. Density-dependent saturation velocity in the range
+of 1.6x10^{7} cm/s reducing to 2x10^{6} cm/s is predicted for {\delta}-doped
+BaSnO3 channels with carrier densities ranging from 10^{13} cm^{-2} to
+2x10^{14} cm^{-2} respectively. These results are expected to aid the informed
+design of BaSnO3 as the active material for high-charge density electronic
+transistors.",1905.05112v2
+2020-03-19,Gas relative permeability in unconventional reservoir rocks,"Accurate modeling of gas relative permeability has practical applications in
+oil and gas exploration, production and recovery of unconventional reservoirs.
+In this study, we apply concepts from the effective-medium approximation (EMA)
+and universal power-law scaling from percolation theory. Although the EMA has
+been successfully used to estimate relative permeability in conventional porous
+media, to the best of our knowledge, its applications to unconventional
+reservoir rocks have not been addressed yet. The main objective of this study,
+therefore, is to evaluate the efficiency of EMA, in combination with universal
+power-law scaling from percolation theory, in estimating gas relative
+permeability from pore size distribution and pore connectivity. We presume that
+gas flow is mainly controlled by two main mechanisms contributing in parallel
+(1) hydraulic flow and (2) molecular flow. We then apply the EMA to determine
+effective conductances and, consequently, gas relative permeability at higher
+gas saturations, and the universal scaling from percolation theory at lower gas
+saturation values. Comparisons with two pore-network simulations and six
+experimental measurements from the literature show that, in the absence of
+microfractures, the proposed model estimates gas relative permeability
+reasonably well in shales and tight porous rocks. More specifically, we found
+that the crossover point, gas saturation at which transport crosses from
+percolation theory to the EMA, is non-universal. The value of crossover gas
+saturation is a function of pore space characteristics such as pore size
+distribution broadness and critical gas saturation. This means that one should
+expect the crossover gas saturation to vary from one rock sample to another.",2003.08988v1
+2020-12-28,Almost all permutation matrices have bounded saturation functions,"Saturation problems for forbidden graphs have been a popular area of research
+for many decades, and recently Brualdi and Cao initiated the study of a
+saturation problem for 0-1 matrices. We say that 0-1 matrix $A$ is saturating
+for the forbidden 0-1 matrix $P$ if $A$ avoids $P$ but changing any zero to a
+one in $A$ creates a copy of $P$. Define $sat(n, P)$ to be the minimum possible
+number of ones in an $n \times n$ 0-1 matrix that is saturating for $P$. Fulek
+and Keszegh proved that for every 0-1 matrix $P$, either $sat(n, P) = O(1)$ or
+$sat(n, P) = \Theta(n)$. They found two 0-1 matrices $P$ for which $sat(n, P) =
+O(1)$, as well as infinite families of 0-1 matrices $P$ for which $sat(n, P) =
+\Theta(n)$. Their results imply that $sat(n, P) = \Theta(n)$ for almost all $k
+\times k$ 0-1 matrices $P$.
+  Fulek and Keszegh conjectured that there are many more 0-1 matrices $P$ such
+that $sat(n, P) = O(1)$ besides the ones they found, and they asked for a
+characterization of all permutation matrices $P$ such that $sat(n, P) = O(1)$.
+We affirm their conjecture by proving that almost all $k \times k$ permutation
+matrices $P$ have $sat(n, P) = O(1)$. We also make progress on the
+characterization problem, since our proof of the main result exhibits a family
+of permutation matrices with bounded saturation functions.",2012.14150v1
+2021-12-28,Investigating the migration of immiscible contaminant fluid flow in homogeneous and heterogeneous aquifers with high-precision numerical simulations,"Numerical modeling of the migration of three-phase immiscible fluid flow in
+variably saturated zones is challenging due to the different behavior of the
+system between unsaturated and saturated zones. This behavior results in the
+use of different numerical methods for the numerical simulation of the fluid
+flow depending on whether it is in the unsaturated or saturated zones. This
+paper shows that using a high-resolution shock-capturing conservative method to
+resolve the nonlinear governing coupled partial differential equations of a
+three-phase immiscible fluid flow allows the numerical simulation of the system
+through both zones providing a unitary vision (and resolution) of the migration
+of an immiscible contaminant problem within a porous medium. In particular,
+using different initial scenarios (including impermeable 'lenses' in
+heterogeneous aquifers), three-dimensional numerical simulation results are
+presented on the temporal evolution of the contaminant migration following the
+saturation profiles of the three-phases fluids flow in variably saturated
+zones. It is considered either light nonaqueous phase liquid with a density
+less than the water, or dense nonaqueous phase liquid, which has densities
+greater than the water initially released in unsaturated dry soil. Our study
+shows that the fate of the migration of immiscible contaminants in variably
+saturated zones can be accurately described, using a unique mathematical
+conservative model, with different evolution depending on the value of the
+system's physical parameters, including the contaminant density, and accurately
+tracking the evolution of the sharp (shock) contaminant front.",2112.14229v2
+2024-03-20,Saturation and fluctuations in the proton wavefunction at large momentum transfers in exclusive diffraction at HERA,"We present a model of proton geometry where the number and size of gluon
+density hotspots in the proton's thickness function evolves with the resolution
+scale of the event given by the Mandelstam $t$ variable in exclusive
+diffractive $ep$ collisions. We use the impact-parameter dependent saturation
+dipole model bSat/IPSat, as well as its linearised (non-saturated) version
+bNonSat. In the latter the proton thickness has a clear interpretation as a
+thickness and in the former it is directly related to the saturation scale. The
+resulting phenomenological model for the splitting of hotspots, making full use
+of earlier experimental and phenomenological studies, is able to describe the
+entire incoherent $t$-spectrum for $|t|>1.1~$GeV$^2$ with a single
+phenomenological parameter. We use the previously suggested hotspot model as an
+initial condition for our evolution. The resulting model is a resolution
+scale-evolution in the same vein as a parton shower.The incoherent cross
+section is directly proportional to geometrical fluctuations in the proton's
+inital state. The hotspot evolution give rise to several kinds of
+event-by-event fluctuations such as in the hotspot number, width and
+normalization, and saturation scale fluctuations is a direct effect of these. A
+natural consequence of our resolution based evolution is that the hotspots
+obtain an effective repulsion. We use our hotspot evolution model to
+investigate saturation scale effects in the $t$-spectrum, and found that HERA
+data is not sensitive to this physics.",2403.13631v1
+1999-06-01,Error-Correcting Codes That Nearly Saturate Shannon's Bound,"Gallager-type error-correcting codes that nearly saturate Shannon's bound are
+constructed using insight gained from mapping the problem onto that of an Ising
+spin system. The performance of the suggested codes is evaluated for different
+code rates in both finite and infinite message length.",9906011v1
+2001-09-21,Illumination of quantum Hall effect,"We show that illumination by continuous white radiation saturates the
+population of levels so that some of the transitions are not observed. This
+reduces the number of observable transitions so that the resolution of
+transitions is improved. In the case of \nu = 11/2 the improved resolution
+leads to clear observation of zero in the transverse resistivity which appears
+as a finite resistivity in absence of saturating radiation.",0109407v1
+1999-07-01,"Parton saturation, production, and equilibration in high energy nuclear collisions","Deeply inelastic scattering of electrons off nuclei can determine whether
+parton distributions saturate at HERA energies. If so, this phenomenon will
+also tell us a great deal about how particles are produced, and whether they
+equilibrate, in high energy nuclear collisions.",9907209v1
+1999-09-13,The Logarithmic Derivative of the F_{2} Structure Function and Saturation,"We show that when screening corrections are included $\frac{\partial
+F_{2}(x,Q^{2})}{\partial ln(Q^{2}/Q_{0}^{2})}$ is consistent with the behaviour
+that one expects in pQCD. Screening corrections explain the enigma of the
+Caldwell plot. Saturation has not been reached at present HERA energies.",9909343v1
+2001-11-20,Parton Saturation-An Overview,"The idea of partons and the utility of using light-cone gauge in QCD are
+introduced. Saturation of quark and gluon distributions are discussed using
+simple models and in a more general context. The Golec-Biernat W\usthoff model
+and some simple phenomenology are described. A simple, but realistic, equation
+for unitary, the Kovchegov equation, is discussed, and an elementary derivation
+of the JIMWLK equation is given.",0111244v1
+2002-03-27,A Modification of the Saturation Model: DGLAP evolution,"We propose to modify the saturation model of Golec-Biernat and Wusthoff by
+including DGLAP evolution. We find considerable improvement for the total deep
+inelastic cross section, in particular in the large Q^2 region. The successful
+description of DIS diffraction is preserved.",0203258v2
+2002-05-22,Saturation at low x and nonlinear evolution,"In this talk the results of the analytical and numerical analysis of the
+nonlinear Balitsky-Kovchegov equation are presented. The characteristic BFKL
+diffusion into infrared regime is suppressed by the generation of the
+saturation scale. We identify the scaling and linear regimes for the solution.
+We also study the impact of subleading corrections onto the nonlinear
+evolution.",0205249v1
+2002-06-13,Saturation and Vector Mesons,"Through an analysis of diffractive vector meson production, we show that the
+proton appears quite dense to a small size probe at present HERA energies. This
+means that saturation effects are already important.",0206117v1
+2002-07-02,DGLAP evolution in the saturation model,"A modification of the saturation model of deep inelastic scattering at small
+x which includes the Altarelli-Parisi (DGLAP) evolution is presented.
+Significant improvement of the description of the structure function F_2 at
+large Q^2 is achieved and a good description of diffractive data is preserved.",0207031v1
+2002-08-27,Towards strangeness saturation in central heavy-ion collisions at high energies,"Analyses of the centrality binned identified hadron multiplicities at SPS and
+RHIC within the statistical-thermal model point to strangeness saturation with
+increasing centrality and energy.",0208247v1
+2003-04-29,"Strangeness Saturation: Dependence on System-Size, Centrality and Energy","The dependence of the strangeness saturation factor on the system size,
+centrality and energy is studied in relativistic heavy-ion collisions.",0304269v1
+2003-05-02,Is Quark Saturation Related to the Pauli Principle?,"Below the saturation momentum the sea quark occupation number reaches a pure
+number, independent of any parameters in QCD, reminiscent of a Pauli Principle
+result. We argue, however, that the Pauli Principle plays no role in the
+result.",0305023v2
+2003-07-14,Hard-soft Pomeron transition from QCD saturation in the dipole picture,"We pose the question: how far can we push the QCD dipole model and the idea
+of QCD saturation to the kinematical regions traditionally associated with soft
+nonperturbative physics? The answer is that it works sufficiently well allowing
+a smooth transition from hard (BFKL) pomeron to the soft one.",0307174v1
+2003-11-21,Saturation and Diffractive DIS,"We review QCD based descriptions of diffractive deep inelastic scattering
+emphasizing the role of models with parton saturation. These models provide
+natural explanation of such experimentally observed facts as the constant ratio
+of diffractive and total DIS cross sections as a function of the Bjorken
+variable x and Regge factorization of diffractive parton distributions.",0311278v2
+2004-08-24,Saturation scale from the Balitsky-Kovchegov equation,"Recently Munier and Peschanski presented an analysis of the
+Balitsky--Kovchegov (BK) equation concerning the extraction of the saturation
+scale, using a simpler equation. We numerically analyze the full BK equation
+confirming the universality of their analysis.",0408255v1
+2004-12-22,"DIS at low x, phenomenological aspects","Saturation at low x appears as an almost unavoidable consequence of the
+two-gluon exchange generic structure. Consistency of the ansatz for the vector
+part of the color dipole cross section with conventional evolution determines
+the energy dependence of the saturation scale.",0412334v1
+2005-01-03,Saturation and High Density QCD,"Recent progress in understanding general properties of high energy scattering
+near the unitarity limit, where high density gluon components of the
+wavefunction are dominant, is reviewed. The similarity of the QCD problem and
+that of reaction-diffusion processes in statistical physics is emphasized. The
+energy dependence of the saturation momentum and the status of geometric
+scaling are discussed.",0501012v1
+2005-04-06,Saturation effects at LHC energies,"Within the framework of a modified Balitsky-Kovchegov equation, we calculated
+and provide estimates of non-linear saturation effects expected in the LHC
+range of energies.",0504040v3
+2005-10-30,Possible saturation effects at HERA and LHC in the $k_T$-factorization approach,"We consider possible saturation effects in the structure function $F_L$ at
+fixed W in HERA energy range and in $b\bar b-$production at LHC energies in the
+framework of $k_T-$facrorization approach.",0510403v1
+2005-11-03,Recent results on saturation and CGC,"I discuss recent results on the Color Glass Condensate which is a dense
+saturated gluonic state and appears as the universal picture of hadrons or
+nuclei at very high energies.",0511031v1
+2000-04-26,BPS Saturated Vacua Interpolation along One Compact Dimension,"A class of generalized Wess-Zumino models with distinct vacua is
+investigated. These models allow for BPS saturated vacua interpolation along
+one compact spatial dimension. The properties of these interpolations are
+studied.",0004178v2
+1993-04-12,The automorphism group of a saturated model has a large dense free subgroup,"We prove that for a stable theory $T,$ if $M$ is a saturated model of $T$ of
+cardinality $\lambda$ where $\lambda > \big|T\big|,$ then $Aut(M)$ has a dense
+free subgroup on $2^{\lambda}$ generators. This affirms a conjecture of Hodges.",9304201v1
+2003-04-15,Automorphism groups of saturated structures; a review,"We will review the main results concerning the automorphism groups of
+saturated structures which were obtained during the two last decades. The main
+themes are: the small index property in the countable and uncountable cases;
+the possibility of recovering a structure or a significant part of it from its
+automorphism group; the subgroup of strong automorphisms.",0304205v1
+2006-06-28,Reidemeister numbers of saturated weakly branch groups,"We prove for a wide class of saturated weakly branch group (including the
+(first) Grigorchuk group and the Gupta-Sidki group) that the Reidemeister
+number of any automorphism is infinite.",0606725v1
+2004-02-04,Nuclear matter saturation in a relativistic chiral theory and QCD susceptibilities,"We study a chiral relativistic theory of nuclear matter aimed at the
+desciption of both the binding and saturation properties and the QCD
+properties, quark condensate and QCD susceptibilities. For this purpose the
+nucleon scalar response of the quark-meson coupling model is introduced in the
+linear sigma model. The consequences for the nuclear and the QCD scalar
+susceptibilities are discussed.",0402018v1
+2000-09-03,Soliton Generation and Picosecond Collapse in Solid-State Lasers with Semiconductor Saturable Absorber,"Based on self - consistent field theory we study a soliton generation in cw
+solid-state lasers with semiconductor saturable absorber. Various soliton
+destabilizations, i.e. the switch from femtosecond to picosecond generation
+(''picosecond collapse''), an automodulation regime, breakdown of soliton
+generation and hysteresis behavior, are predicted.",0009009v1
+2000-09-21,Nonlinear Effects in CW Mode-Locked Solid-State Lasers with Semiconductor Saturable Absorbers,"The influence of nonlinear properties of semiconductor saturable absorbers on
+ultrashort pulse generation was investigated. It was shown, that linewidth
+enhancement, quadratic and linear ac Stark effect contribute essentially to the
+mode locking in cw solid-state lasers, that can increase the pulse stability,
+decrease pulse duration and reduce the mode locking threshold",0009067v1
+2007-08-30,Broadening of band-gap in photonic crystals with optically saturated media,"Due to strong absorption of the incident light, the media with high
+refractive index are considered restrictive for applications in photonic
+crystals (PhCs). The possibility to resolve this problem by optical saturation
+effectively minimizing the absorption of the PhC medium is discussed. Such
+approach might be promising for the significant broadening of the photonic
+band-gap.",0708.4043v1
+2007-11-30,Coherent backscattering of light from saturated atoms,"We survey recent progress achieved in understanding the impact of inelastic
+processes on coherent backscattering of light from cold atoms that are
+saturated by a powerful laser field.",0711.4960v1
+2008-07-15,"Saturated extensions, the attractors method and Hereditarily James Tree Space","In the present work we provide a variety of examples of HI Banach spaces
+containing no reflexive subspace and we study the structure of their duals as
+well as the spaces of their linear bounded operators. Our approach is based on
+saturated extensions of ground sets and the method of attractors.",0807.2392v1
+2009-03-24,Note on inconsistency of unitarity saturation and maximal odderon,"It is shown that regime of elastic scattering with maximal odderon
+contribution is not compatible with unitarity and black disk limits saturation.",0903.4042v2
+2009-07-09,Gluon saturation effects on J/Psi production in heavy ion collisions,"We discuss a novel mechanism for J/Psi$ production in nuclear collisions
+arising due to the high density of gluons. We demonstrate that gluon saturation
+in the colliding nuclei is a dominant source of J/Psi suppression and can
+explain its experimentally observed rapidity and centrality dependence.",0907.1604v2
+2009-10-21,On the different regimes of subaqueous transport,"We review different aspects of subaqueous sediment transport. We discuss the
+static threshold and its dependency with longitudinal and transverse slopes, as
+well as cohesion. We describe the different regimes of transport: erosion and
+momentum limited bed load, and suspended load. In all these cases, we derive
+the expressions of the saturation flux $q_{\rm sat}$ and the saturation length
+$L_{\rm sat}$ and discuss their dependencies.",0910.4119v1
+2010-03-03,The cofinal property of the Reflexive Indecomposable Banach spaces,"It is shown that every separable reflexive Banach space is a quotient of a
+reflexive Hereditarily Indecomposable space, which yields that every separable
+reflexive Banach is isomorphic to a subspace of a reflexive Indecomposable
+space. Furthermore, every separable reflexive Banach space is a quotient of a
+reflexive complementably $\ell_p$ saturated space with $1<p<\infty$ and of a
+$c_0$ saturated space.",1003.0870v1
+2010-03-24,"Wideband tunable, graphene-mode locked, ultrafast laser","We report a tunable ultrafast fiber laser mode-locked with a graphene
+saturable absorber. The linear dispersions of the Dirac electrons in graphene
+enable wideband tunability. We get ~1ps pulses, tunable between 1525 and
+1559nm, demonstrating graphene as a broadband saturable absorber.",1003.4714v1
+2010-05-30,Sparse fusion systems,"We define sparse saturated fusion systems and show that, for odd primes,
+sparse systems are constrained. This simplifies the proof of the
+Glauberman-Thompson p-nilpotency theorem for fusion systems and a related
+theorem of Stellmacher. We then define a more restrictive class of saturated
+fusion systems, called extremely sparse, that are constrained for all primes.",1005.5503v1
+2010-06-30,A Saturation Method for the Modal Mu-Calculus with Backwards Modalities over Pushdown Systems,"We present an extension of an algorithm for computing directly the denotation
+of a mu-calculus formula X over the configuration graph of a pushdown system to
+allow backwards modalities. Our method gives the first extension of the
+saturation technique to the full mu-calculus with backwards modalities.",1006.5906v1
+2010-09-01,Color Glass Condensate and Glasma,"In this talk, I review the Color Glass Condensate theory of gluon saturation,
+and its application to the early stages of heavy ion collisions.",1009.0093v2
+2010-10-11,Infinite saturated orders,"We generalize the notion of saturated order to infinite partial orders and
+give both a set-theoretic and an algebraic characterization of such orders. We
+then study the proof theoretic strength of the equivalence of these
+characterizations in the context of reverse mathematics, showing that depending
+on one's choice of definitions it is either provable in $\mathsf{RCA}_0$ or
+equivalent to $\mathsf{ACA}_0$.",1010.2219v1
+2011-06-08,Saturation of Coulomb sum rules in the 6^Li case,"The Coulomb sums S_L(q) of the 6^Li nucleus have been obtained from electron
+scattering measurements at 3-momentum transfers q = 1.125 - 1.625 fm^{-1}. It
+is found that at q > 1.35 fm^{-1} the Coulomb sum of the nucleus becomes
+saturated: S_L(q) = 1.",1106.1538v1
+2011-09-21,The stellar activity-rotation relationship and the evolution of stellar dynamos,"We present a sample of 824 solar and late-type stars with X-ray luminosities
+and rotation periods. This is used to study the relationship between rotation
+and stellar activity and derive a new estimate of the convective turnover time.
+From an unbiased subset of this sample the power law slope of the unsaturated
+regime, L_X / L_bol = Ro^\beta, is fit as \beta = -2.70 +/- 0.13. This is
+inconsistent with the canonical \beta=-2 slope to a confidence of 5 sigma, and
+argues for an additional term in the dynamo number equation. From a simple
+scaling analysis this implies \Delta\Omega / \Omega = \Omega^0.7, i.e. the
+differential rotation of solar-type stars gradually declines as they spin down.
+Super-saturation is observed for the fastest rotators in our sample and its
+parametric dependencies are explored. Significant correlations are found with
+both the corotation radius and the excess polar updraft, the latter theory
+providing a stronger dependence and being supported by other observations. We
+estimate mass-dependent empirical thresholds for saturation and
+super-saturation and map out three regimes of coronal emission. Late F-type
+stars are shown never to pass through the saturated regime, passing straight
+from super-saturated to unsaturated X-ray emission. The theoretical threshold
+for coronal stripping is shown to be significantly different from the empirical
+saturation threshold (Ro < 0.13), suggesting it is not responsible. Instead we
+suggest that a different dynamo configuration is at work in stars with
+saturated coronal emission. This is supported by a correlation between the
+empirical saturation threshold and the time when stars transition between
+convective and interface sequences in rotational spin-down models.",1109.4634v1
+2011-09-29,Affine Sieve,"We establish the main saturation conjecture in [BGS10] connected with
+executing a Brun sieve in the setting of an orbit of a group of affine linear
+transformations. This is carried out under the condition that the Zariski
+closure of the group is Levi-semisimple. It is likely that this condition is
+also necessary for such saturation to hold.",1109.6432v1
+2011-11-21,"Comment on ""Saturation of the All-Optical Kerr Effect""","Br\'ee, Demircan, and Steinmeyer [Phys. Rev. Lett. 106, 183902 (2011)]
+recently calculated higher-order Kerr effect (HOKE) coefficients using the
+nonlinear Kramers-Kronig relations. We show that the saturated and negative
+nonlinear index of refraction obtained by Br\'ee et al. is an artifact of their
+use of a perturbative theory of ionization in an intensity region where it
+breaks down.",1111.4932v1
+2012-12-17,"Small x, Saturation, and Diffraction in Collisions with electrons, protons, and nuclei","The Lund dipole model DIPSY is based on BFKL evolution and saturation. It can
+be applied to collisions between electrons, protons, and nuclei. In this talk I
+present some recent results for exclusive final states in inelastic collisions,
+a method to generate final states in diffractive excitation, and some results
+for collisions with nuclei.",1212.3977v1
+2013-01-07,On saturated uniformly A-convex algebras,"Following ideas of A.C.Cochran, we give a suitable definition of a saturated
+uniformly A-convex algebra. In the m-convex case, such algebra is a uniform
+topological one.",1301.1207v3
+2013-04-19,On Thompson's $p$-complement theorems for saturated fusion systems,"In this short note we prove that a saturated fusion system admitting some
+special type of automorphism is nilpotent. This generalizes classical results
+by J.G. Thompson.",1304.5352v2
+2013-11-04,Automorphism Groups of Countable Arithmetically Saturated Models of Peano Arithmetic,"If M,N are countable, arithmetically saturated models of Peano Arithmetic and
+Aut(M) is isomorphic to Aut(N), then the Turing-jumps of Th(M) and Th(N) are
+recursively equivalent.",1311.0772v3
+2014-03-13,Properties of random sequential adsorption of generalized dimers,"Saturated random packing of particles built of two identical, relatively
+shifted spheres in two and three dimensional flat and homogeneous space was
+studied numerically using random sequential adsorption algorithm. The shift
+between centers of spheres varied from 0.0 to 8.0 sphere diameters. Numerical
+simulations allowed determine random sequential adsorption kinetics, saturated
+random coverage ratio as well as available surface function and density
+autocorrelation function.",1403.3200v1
+2014-05-28,Singularly perturbed elliptic problems with nonautonomous asymptotically linear nonlinearities,"We consider a class of singularly perturbed elliptic problems with
+nonautonomous asymptotically linear nonlinearities. The dependence on the
+spatial coordinates comes from the presence of a potential and of a function
+representing a saturation effect. We investigate the existence of nontrivial
+nonnegative solutions concentrating around local minima of both the potential
+and of the saturation function. Necessary conditions to locate the possible
+concentration points are also given.",1405.7166v1
+2014-06-16,Saturation of a large scale instability and non linear stuctures in a rotating stratified flow,"In this letter, we present non linear structures resulting from the
+saturation of a large scale instability in rotating stratified fluids with
+small scale forced turbulence which we found in \cite{[1]}. These structures
+are of helical kinks type. The different solutions that we plotted correspond
+to solutions linking two different stationnary points for different values of
+the Rayleigh and the Taylor numbers.",1406.3962v1
+2014-12-01,Neutrosophic information in the framework of multi-valued representation,"The paper presents some steps for multi-valued representation of neutrosophic
+information. These steps are provided in the framework of multi-valued logics
+using the following logical value: true, false, neutral, unknown and saturated.
+Also, this approach provides some calculus formulae for the following
+neutrosophic features: truth, falsity, neutrality, ignorance,
+under-definedness, over-definedness, saturation and entropy. In addition, it
+was defined net truth, definedness and neutrosophic score.",1412.4802v1
+2015-03-14,CGC/saturation approach for soft interactions at high energy: inclusive production,"In this letter we demonstrate that our dipole model is successful in
+describing the inclusive production within the same framework as diffractive
+physics. We believe that this achievement stems from the fact that our approach
+incorporates the positive features of the Reggeon approach and CGC/saturation
+effective theory, for high energy QC",1503.04294v1
+2014-12-19,Kinematics of Electrons in The Volume of a Planar Vacuum Diode in Regime of Saturation. Parameters of Hysteresis,"The kinematics laws of electrons motion in the volume of a planar vacuum
+diode running in regime of current saturation are used. The characteristics of
+diode hysteresis in the conditions of S-figurative instability are got and
+analyzed.",1503.06646v1
+2015-05-22,Approximations of superstability in concrete accessible categories,"We generalize the constructions and results of Chapter 10 in Baldwin's
+""Categoricity"" to coherent accessible categories with concrete directed
+colimits and concrete monomorphisms. In particular, we prove that if any
+category of this form is categorical in a successor, directed colimits of
+saturated objects are themselves saturated.",1505.06047v1
+2015-12-06,Good ultrafilters and highly saturated models: a friendly explanation,"Highly saturated models are a fundamental part of the model-theoretic
+machinery of nonstandard analysis. Of the two methods for producing them,
+ultrapowers constructed with the aid of $\kappa^+$-good ultrafilters seems by
+far the less popular. Motivated by the hypothesis that this is partly due to
+the standard exposition being somewhat dense, a presentation is given which is
+designed to be easier to digest.",1512.01827v1
+2016-05-09,The strength of countable saturation,"We determine the proof-theoretic strength of the principle of countable
+saturation in the context of the systems for nonstandard arithmetic introduced
+in our earlier work.",1605.02534v2
+2016-05-25,On the topological pressure of the saturated set with non-uniform structure,"We derive a conditional variational principle of the saturated set for
+systems with the non-uniform structure. Our result applies to a broad class of
+systems including beta-shifts, S-gap shifts and their factors.",1605.07845v1
+2016-07-17,"Converse results, saturation and quasi-optimality for Lavrentiev regularization of accretive problems","This paper deals with Lavrentiev regularization for solving linear ill-posed
+problems, mostly with respect to accretive operators on Hilbert spaces. We
+present converse and saturation results which are an important part in
+regularization theory. As a byproduct we obtain a new result on the
+quasi-optimality of a posteriori parameter choices. Results in this paper are
+formulated in Banach spaces whenever possible.",1607.04879v1
+2016-09-21,Unconditionally saturated Banach space with the scalar-plus-compact property,"We construct a Bourgain-Delbaen $\mathscr{L}_\infty$-space
+$\mathfrak{X}_{Kus}$ with strongly heterogenous structure: any bounded operator
+on $\mathfrak{X}_{Kus}$ is a compact perturbation of a multiple of the
+identity, whereas the space $\mathfrak{X}_{Kus}$ is saturated with
+unconditional basic sequences.",1609.06506v2
+2016-11-04,Unique Prediction for High-Energy J/ψPhotoproduction: Color Transparency and Saturation,"Based on the color-dipole picture, we present a successful parameter-free
+prediction for the recent high-energy $J/\psi$ photoproduction data from the
+Large Hadron Collider. The experimental data provide empirical evidence for the
+transition from color transparency to saturation.",1611.01382v1
+2017-10-22,Coupled complex Ginzburg-Landau systems with saturable nonlinearity and asymmetric cross-phase modulation,"We formulate and study dynamics from a complex Ginzburg-Landau system with
+saturable nonlinearity, including asymmetric cross-phase modulation (XPM)
+parameters. Such equations can model phenomena described by complex
+Ginzburg-Landau systems under the added assumption of saturable media. When the
+saturation parameter is set to zero, we recover a general complex cubic
+Ginzburg-Landau system with XPM. We first derive conditions for the existence
+of bounded dynamics, approximating the absorbing set for solutions. We use this
+to then determine conditions for amplitude death of a single wavefunction. We
+also construct exact plane wave solutions, and determine conditions for their
+modulational instability. In a degenerate limit where dispersion and
+nonlinearity balance, we reduce our system to a saturable nonlinear
+Schr\""odinger system with XPM parameters, and we demonstrate the existence and
+behavior of spatially heterogeneous stationary solutions in this limit. Using
+numerical simulations we verify the aforementioned analytical results, while
+also demonstrating other interesting emergent features of the dynamics, such as
+spatiotemporal chaos in the presence of modulational instability. In other
+regimes, coherent patterns including uniform states or banded structures arise,
+corresponding to certain stable stationary states. For sufficiently large yet
+equal XPM parameters, we observe a segregation of wavefunctions into different
+regions of the spatial domain, while when XPM parameters are large and take
+different values, one wavefunction may decay to zero in finite time over the
+spatial domain (in agreement with the amplitude death predicted analytically).
+While saturation will often regularize the dynamics, such transient dynamics
+can still be observed - and in some cases even prolonged - as the saturability
+of the media is increased, as the saturation may act to slow the timescale.",1710.07968v2
+2017-12-13,Approximate controllability for Navier--Stokes equations in $\mathrm{3D}$ rectangles under Lions boundary conditions,"The $\mathrm{3D}$ Navier--Stokes system, under Lions boundary conditions, is
+proven to be approximately controllable provided a suitable saturating set does
+exist. An explicit saturating set for $\mathrm{3D}$ rectangles is given.",1712.04900v1
+2018-02-13,Selfinjective algebras having a generalized standard family of quasi-tubes maximally saturated by simple and projective modules,"We give a complete description of finite dimensional selfinjective algebras
+over an algebraically closed field whose Auslander-Reiten quiver admits a
+generalized standard family of quasi-tubes maximally saturated by simple and
+projective modules. In particular, we show that these algebras are
+selfinjective algebras of strictly canonical type.",1802.04577v1
+2018-11-20,Elementary Equivalence Theorem for PAC structures,"We generalize a well-known theorem binding the elementary equivalence
+relation on the level of PAC fields and the isomorphism class of their absolute
+Galois groups. Our results concern two cases: saturated PAC structures and
+non-saturated PAC structures.",1811.08510v3
+2018-11-26,Localized chaos of elliptically polarized cavity solitons in broad-area VCSEL with saturable absorber,"We introduce a spin-flip model for a broad-area Vertical-Cavity
+Surface-Emitting Laser (VCSEL) with a saturable absorber. We demonstrate
+simultaneous existence of orthogonally linearly polarized and elliptically
+polarized cavity solitons. We show that polarization degree of freedom leads to
+period doubling route to spatially localized chaos of the elliptically
+polarized cavity solitons.",1811.10350v1
+2018-12-28,Estimating Some General Molecular Descriptors of Saturated Hydrocarbons,"Three general molecular descriptors, namely the general sum-connectivity
+index, general Platt index and ordinary generalized geometric-arithmetic index,
+are studied here. Best possible bounds for the aforementioned descriptors of
+arbitrary saturated hydrocarbons are derived. These bounds are expressed in
+terms of number of carbon atoms and number of carbon-carbon bonds of the
+considered hydrocarbons.",1812.11115v1
+2019-01-04,More rigid ideals,"We extend prior results of Cody-Eskew, showing the consistency of GCH with
+the statement that for all regular cardinals $\kappa \leq \lambda$, where
+$\kappa$ is the successor of a regular cardinal, there is a rigid saturated
+ideal on $\mathcal{P}_\kappa\lambda$. We also show the consistency of some
+instances of rigid saturated ideals on $\mathcal{P}_\kappa\lambda$ where
+$\kappa$ is the successor of a singular cardinal.",1901.02075v1
+2019-07-24,"The norm of the saturation of a binomial ideal, and applications to Markov bases","Given a pure binomial ideal I in variables x_i, we define a new measure of
+the complexity of the saturation of I with respect to the product of the
+variables x_i, which we call the norm. We give a bound on the norm in terms of
+easily-computed invariants of the ideal. We discuss statistical applications
+both practical and theoretical.",1907.10268v1
+2019-12-20,Miniaturized saturated absorption spectrometer,"We describe a saturated absorption setup that is robust, compact and require
+minimum alignment. These properties are attained using a diffuse probe beam
+generated by a retro-reflecting film. This concept was studied and applied to
+built a miniaturized setup that had shown the same performance than an
+optimized table-top experiment.",1912.10060v1
+2019-12-20,Hadron multiplicity calculation: a configurational entropy approach to the saturation scale in QCD,"This paper investigates the configurational entropic content of
+hadron-nucleus collisions. Hadron multiplicities and Au nuclei are employed to
+compute the critical points of the configurational entropy as a function of the
+saturation scale in deep inelastic scatterings, in QCD. The results match
+phenomenological data to the precision of 0.39%.",1912.10071v1
+2020-01-06,Non-Stationary Saturation of Inhomogeneously Broadened Spin Systems with Effective Cross-Relaxation,"Non-stationary saturation of inhomogeneously broadened EPR lines is
+investigated under effective cross-relaxation. The generalized kinetic
+equations are solved and the complex susceptibility is calculated. All
+quantities change in time exponentially.",2001.01362v2
+2020-01-17,Non-Stationary Saturation of Inhomogeneously Broadened EPR Lines,"Non-stationary saturation of inhomogeneously broadened EPR lines is studied
+when cross-relaxation has the characteristics of spectral diffusion. A system
+of generalized kinetic equations is solved in quadratures in this
+approximation. The result is valid not only when the contribution of the
+spectral diffusion is negligible or dominant, but also in the intermediate
+case.",2001.06461v1
+2020-03-01,Criteria for exact saturation and singular compactness,"We introduce the class of unshreddable theories, which contains the simple
+and NIP theories, and prove that such theories have exactly saturated models in
+singular cardinals, satisfying certain set-theoretic hypotheses. We also give
+criteria for a theory to have singular compactness.",2003.00597v2
+2020-05-12,Fundamental pushouts of n-complicial sets,"The paper focuses on investigating how certain relations between strict
+$n$-categories are preserved in a particular implementation of
+$(\infty,n)$-categories, given by saturated $n$-complicial sets. In this model,
+we show that the $(\infty,n)$-categorical nerve of $n$-categories is
+homotopically compatible with $1$-categorical suspension and wedge. As an
+application, we show that certain pushouts encoding composition in
+$n$-categories are homotopy pushouts of saturated $n$-complicial sets.",2005.05844v1
+2020-05-26,VC-saturated set systems,"The well-known Sauer lemma states that a family $\mathcal{F}\subseteq
+2^{[n]}$ of VC-dimension at most $d$ has size at most
+$\sum_{i=0}^d\binom{n}{i}$. We obtain both random and explicit constructions to
+prove that the corresponding saturation number, i.e., the size of the smallest
+maximal family with VC-dimension $d\ge 2$, is at most $4^{d+1}$, and thus is
+independent of $n$.",2005.12545v2
+2020-07-02,Gray tensor product and saturated $N$-complicial sets,"We show that the pretensor and tensor products of simplicial sets with
+marking are compatible with the homotopy theory of saturated $N$-complicial
+sets (which are a proposed model of $(\infty,N)$-categories), in the form of a
+Quillen bifunctor and a homotopical bifunctor, respectively.",2007.01235v1
+2020-11-10,The continuation of finite $E_\mathfrak{F}$-groups theory,"We describe the structure of finite groups with $\mathfrak{F}$-subnormal or
+self-normalizing primary cyclic subgroups when $\mathfrak{F}$ is a
+subgroup-closed saturate superradical formation containing all nilpotent
+groups. We prove that groups with absolutely $\mathfrak{F}$-subnormal or
+self-normalizing primary cyclic subgroups are soluble when $\mathfrak{F}$ is a
+subgroup-closed saturate formation containing all nilpotent groups.",2011.05291v1
+2020-11-17,The catenary degree of the saturated numerical semigroups with prime multiplicity,"In this paper we present the set of saturated numerical semigroups with prime
+multiplicity. We also characterize the catenary degree of these semigroups that
+we acquire. The catenary degree of a numerical semigroup is the variant which
+measures the distance between factorizations of elements within that numerical
+semigroup.",2011.08929v1
+2020-12-22,The Lipschitz Saturation of a Module,"In this work we extend the concept of the Lipschitz saturation of an ideal
+defined in [5] to the context of modules in some different ways, and we prove
+they are generically equivalent.",2012.12239v1
+2021-01-19,Indices of equilibrium points of linear control systems with saturated state feedback,"In this paper we investigate some properties of equilibrium points in
+n-dimensional linear control systems with saturated state feedback. We provide
+an index formula for equilibrium points and discuss its relation to boundaries
+of attraction basins in feedback systems with single input. In addition, we
+also touch upon convexity of attraction basin.",2101.07474v1
+2021-12-01,A further generalization of the Glauberman-Thompson $p$-nilpotency criterion in fusion systems,"Let $p$ be a prime and $\mathcal{F}$ be a saturated fusion system over a
+finite $p$-group $P$. The fusion system $\mathcal{F}$ is said to be nilpotent
+if $\mathcal{F}=\mathcal{F}_{P}(P)$. We provide new criteria for a saturated
+fusion system $\mathcal{F}$ to be nilpotent, which may be viewed as extending
+the Glauberman-Thompson $p$-nilpotency criterion to fusion systems.",2112.00341v2
+2021-12-14,Upper capacity entropy and packing entropy of saturated sets for amenable group actions,"Let $(X,G)$ be a $G$-action topological system, where $G$ is a countable
+infinite discrete amenable group and $X$ a compact metric space. In this paper
+we study the upper capacity entropy and packing entropy for systems with weaker
+version of specification. We prove that the upper capacity always carries full
+entropy while there is a variational principle for packing entropy of saturated
+sets.",2112.07425v1
+2022-02-15,Saturated Kripke Structures as Vietoris Coalgebras,"We show that the category of coalgebras for the compact Vietoris endofunctor
+$\mathbb{V}$ on the category Top of topological spaces and continuous mappings
+is isomorphic to the category of all modally saturated Kripke structures.
+Extending a result of Bezhanishvili, Fontaine and Venema, we also show that
+Vietoris subcoalgebras as well as bisimulations admit topological closure and
+that the category of Vietoris coalgebras has a terminal object.",2202.07786v1
+2022-03-18,Optimal Dose-Limited Phase Estimation without Entanglement,"Phase estimation is one of the most important facets of quantum metrology,
+with applications in sensing, microscopy, and quantum computation. When
+estimating a phase shift in a lossy medium, there is an upper bound on the
+attainable information per particle sent through the phase shift. Previously,
+only entanglement-enhanced measurements have been shown to saturate this bound.
+We introduce a measurement scheme which can saturate the bound without relying
+on entanglement.",2203.10137v1
+2022-04-07,"Fixed Sets of Automorphisms of Countable, Arithmetically Saturated Structures","If an automorphism f of a structure M is such that fix(f^k) = fix(f) for all
+positive k, then M|fix(f) is a substructure of M. The possible isomorphism
+types of such M|fix(f) are characterized when M is countable and arithmetically
+saturated.",2204.03557v2
+2022-07-20,Prime ideals of the Burnside ring of a saturated fusion system,"In a 1969 article, A. Dress described the prime ideals of the Burnside ring
+of a finite group G and the inclusion relations between them. One may ask
+whether similar results exist for the Burnside ring of a saturated fusion
+system F on a finite p-group S. The present paper answers positively, providing
+a typology for the prime ideals of A(F) and for those of A(F) (p) as a
+consequence.",2207.09722v1
+2022-09-15,Sharpness of saturated fusion systems on a Sylow $p$-subgroup of ${\rm G}_2(p)$,"We prove that the D\'iaz-Park's sharpness conjecture holds for saturated
+fusion systems defined on a Sylow $p$-subgroup of the group ${\rm G}_2(p)$, for
+$p\geq 5$.",2209.07388v2
+2022-10-24,Limits of saturated ideals,"We investigate the question whether a given homogeneous ideal is a limit of
+saturated ones. We provide cohomological necessary criteria for this to hold
+and apply them to a range of examples. Our motivation comes from the theory of
+border apolarity and varieties of sums of powers, where the question above is
+tightly connected to proving new lower bounds for border ranks of tensors.",2210.13579v1
+2023-02-04,Saturated Fusion Systems on Sylow $p$-subgroups of Rank $2$ Simple Groups of Lie Type,"For any prime $p$ and $S$ a $p$-group isomorphic to a Sylow $p$-subgroup of a
+rank $2$ simple group of Lie type in characteristic $p$, we determine all
+saturated fusion systems supported on $S$ up to isomorphism.",2302.02222v1
+2023-02-12,Unified Derivation of Uncertainty Relations and Their Saturation Conditions,"We analyze uncertainty relations due to Kennard, Robertson, Schr\""odinger,
+Maccone and Pati in a unified way from matrix theory point of view. Short
+proofs are given to these uncertainty relations and characterizations of the
+saturation conditions are given.",2302.06002v2
+2023-02-16,Iterative density matrix revisited: Excitonic phenomena to InAs quantum well as a saturable absorber,"By solving the Liouville equation, third-order nonlinear terms is found via
+iterative density matrix. Regarding the improved modeling, all frequency range
+is taken instead of weak absorptive limit. Considered process can be compared
+with saturation fitting for heavy-hole excitons in the InAs quantum well.",2302.08349v1
+2023-05-09,Saturation for Flagged Skew Littlewood-Richardson Coefficients,"We define and study a generalization of the Littlewood-Richardson (LR)
+coefficients, which we call the flagged skew LR coefficients. These subsume
+several previously studied extensions of the LR coefficients. We establish the
+saturation property for these coefficients, generalizing work of Knutson-Tao
+and Kushwaha-Raghavan-Viswanath.",2305.05195v2
+2023-08-24,The generic equivalence among the Lipschitz saturation of a sheaf of modules,"In this work, we extend the concept of the Lipschitz saturation of an ideal
+to the context of modules in some different ways, and we prove they are
+generically equivalent.",2308.13119v1
+2023-08-28,Universally injective and integral contractions on relative Lipschitz saturation of algebras,"In this work, we obtain contraction results for a class of diagrams of ring
+morphisms which strictly includes the ones obtained by Lipman. Further, we
+present some applications on quotient and in the changing of the base ring in
+the saturation.",2308.14624v1
+2023-09-14,A survey on relative Lipschitz saturation of algebras and its relation with radicial algebras,"In this work, we introduce the concept of relative Lipschitz saturation,
+along with its key categorical and algebraic properties, and demonstrate how
+such a structure always gives rise to a radicial algebra.",2309.07965v1
+2023-11-02,Realization of saturated transfer systems on cyclic groups of order $p^nq^m$ by linear isometries $N_\infty$-operads,"We prove a new case of Rubin's saturation conjecture about the realization of
+$G$-transfer systems, for $G$ a finite cyclic group, by linear isometries
+$N_\infty$-operads, namely the case of cyclic groups of order $p^nq^m$ for
+$p,q$ distinct primes and $n,m\in \mathbb{N}$.",2311.01608v1
+2024-02-06,Comment on the paper 'Saturation and Multifractality of Lagrangian and Eulerian Scaling Exponents in Three-Dimensional Turbulence',"We comment on the paper 'Saturation and Multifractality of Lagrangian and
+Eulerian Scaling Exponents in Three-Dimensional Turbulence' by D. Buaria and
+K.R. Sreenivasan. We point out some physical interpretation of the results
+discussed in the paper.",2402.04189v1
+2002-01-07,X-ray Spectra and Pulse Frequency Changes in SAX J2103.5+4545,"The November 1999 outburst of the transient pulsar SAX J2103.5+4545 was
+monitored with the large area detectors of the Rossi X-Ray Timing Explorer
+until the pulsar faded after a year. The 358 s pulsar was spun up for 150 days,
+at which point the flux dropped quickly by a factor of 7, the frequency
+saturated and, as the flux continued to decline, a weak spin-down began. The
+pulses remained strong during the decay and the spin-up/flux correlation can be
+fit to the Ghosh and Lamb derivations for the spin-up caused by accretion from
+a thin, pressure-dominated disk, for a distance 3.2 kpc and a surface magnetic
+field 1.2 10^{13} Gauss. During the bright spin-up part of the outburst, the
+flux was subject to strong orbital modulation, peaking 3 days after periastron
+of the eccentric 12.68 day orbit, while during the faint part, there was little
+orbital modulation. The X-ray spectra were typical of accreting pulsars,
+describable by a cut-off power-law, with an emission line near the 6.4 keV of K
+alpha fluorescence from cool iron. The equivalent width of this emission did
+not share the orbital modulation, but nearly doubled during the faint phase,
+despite little change in the column density. The outburst could have been
+caused by an episode of increased wind from a Be star, such that a small
+accretion disk is formed during each periastron passage. A change in the wind
+and disk structure apparently occurred after 5 months such that the accretion
+rate was no longer modulated or the diffusion time was longer. The distance
+estimate implies the X-ray luminosity observed was between 1 10^{36} ergs
+s^{-1} and 6 \times 10^{34} ergs s^{-1}, with a small but definite correlation
+of the intrinsic power-law spectral index.",0201080v1
+2002-03-19,X-ray emitting young stars in the Orion Nebula,"The Orion Nebula Cluster and the molecular cloud in its vicinity have been
+observed with the ACIS-I detector on board the Chandra X-ray Observatory with
+23 hours exposure. We detect 1075 X-ray sources: 91% are spatially associated
+with known stellar members of the cluster, and 7% are newly identified deeply
+embedded cloud members. This provides the largest X-ray study of a pre-main
+sequence stellar population. We examine here the X-ray properties of Orion
+young stars as a function of mass. Results include: (a) the discovery of rapid
+variability in the O9.5 31 M_o star \theta^2A Ori, and several early B stars,
+inconsistent with the standard model of X-ray production in small wind shocks;
+(b) support for the hypothesis that intermediate-mass mid-B through A type
+stars do not themselves produce significant X-ray emission; (c) confirmation
+that low-mass G- through M-type T Tauri stars exhibit powerful flaring but
+typically at luminosities considerably below the `saturation' level; (d)
+confirmation that the presence or absence of a circumstellar disk has no
+discernable effect on X-ray emission; (e) evidence that T Tauri plasma
+temperatures are often very high with T >= 100 MK, even when luminosities are
+modest and flaring is not evident; and (f) detection of the largest sample of
+pre-main sequence very low mass objects showing high flaring levels and a
+decline in magnetic activity as they evolve into L- and T-type brown dwarfs.",0203316v1
+2002-08-22,"Three-Dimensional Simulations of Parker, Magneto-Jeans, and Swing Instabilities in Shearing Galactic Gas Disks","We use 3D MHD simulations to investigate nonlinear development of the Parker,
+magneto-Jeans (MJI), and swing mechanisms in galactic disks. The model disks
+are local, isothermal, and begin from a vertically-stratified equilibrium. We
+first construct axisymmetric equilibria and examine their stability. Finite
+disk thickness reduces the critical Toomre Q parameter below unity; we find Q_c
+\~ 0.75, 0.72, and 0.57 for \beta=\infty, 10, and 1 cases, respectively. We
+then pursue fully 3D models. In non-self-gravitating cases, the peak density
+enhancement from the `pure' Parker instability is less a factor of two. The
+dominant growing modes have radial wavelengths comparable to the disk scale
+height H, much shorter than the azimuthal wavelength (~10-20 H). Shearing
+disks, being more favorable to midplane-symmetric modes, have somewhat
+different late-time magnetic field profiles from nonshearing disks, but
+otherwise saturated states are similar. Late-time velocity fluctuations at 10%
+of the sound speed persist, but no characteristic structural signatures of
+Parker modes remain in the new equilibria. In self-gravitating cases, the
+development of density structure is qualitatively similar to our previous
+results from thin-disk simulations. The Parker instability, although it may
+help seed structure or tip the balance under marginal conditions, appears to
+play a secondary role. In shearing disks with Q less than a threshold level ~
+1, swing amplification can produce bound clouds of a few times the local Jeans
+mass. The most powerful cloud-condensing mechanism appears to be the MJI. Our
+simulations show that condensations of a local Jeans mass (~3\times 10^7 M_sun)
+grow very rapidly, supporting the idea that MJI is at least partly responsible
+for the formation of bound cloud complexes in spiral galaxies.",0208414v1
+2004-02-27,Chandra observation of an unusually long and intense X-ray flare from a young solar-like star in M78,"LkHA312 has been observed serendipitously with the ACIS-I detector on board
+Chandra with 26h continuous exposure. This H_alpha emission line star belongs
+to the star-forming region M78 (NGC2068). From the optical and NIR data, we
+show that it is a pre-main sequence (PMS) low-mass star with a weak NIR excess.
+This genuine T Tauri star displayed an X-ray flare with an unusual long rise
+phase (~8h). The X-ray emission was nearly constant during the first 18h of the
+observation, and then increased by a factor of 13 during a fast rise phase
+(~2h), and reached a factor of 16 above the quiescent X-ray level at the end of
+a gradual phase (~6h) showing a slower rise. To our knowledge this flare, with
+\~0.4-~0.5 cts/s, has the highest count rate observed so far with Chandra from
+a PMS low-mass star. By chance, the source position, 8.2' off-axis, protected
+this observation from pile-up. We make a spectral analysis of the X-ray
+emission versus time, showing that the plasma temperature of the quiescent
+phase and the flare peak reaches 29MK and 88MK, respectively. The quiescent and
+flare luminosities in the energy range 0.5--8keV corrected from absorption
+(N_H~1.7E21 cm^{-2}) are 6E30erg/s and ~1E32erg/s, respectively. The ratio of
+the quiescent X-ray luminosity on the LkHA312 bolometric luminosity is very
+high with log(L_X/L_bol)= -2.9, implying that the corona of LkHA312 reached the
+`saturation' level. The X-ray luminosity of the flare peak reaches ~2% of the
+stellar bolometric luminosity. The different phases of this flare are finally
+discussed in the framework of solar flares, which leads to the magnetic loop
+height from 3.1E10 to 1E11 cm (0.2-0.5 R*, i.e., 0.5-1.3 R_sun).",0402672v1
+2001-09-25,Single Spin Dynamics and Decoherence in a Quantum Dot via Charge Transport,"We investigate the spin dynamics of a quantum dot with a spin-1/2 ground
+state in the Coulomb blockade regime and in the presence of a magnetic rf field
+leading to electron spin resonances (ESR). We show that by coupling the dot to
+leads, spin properties on the dot can be accessed via the charge current in the
+stationary and non-stationary limit. We present a microscopic derivation of the
+current and the master equation of the dot using superoperators, including
+contributions to decoherence and energy shifts due to the tunnel coupling. We
+give a detailed analysis of sequential and co-tunneling currents, for linearly
+and circularly oscillating ESR fields, applied in cw and pulsed mode. We show
+that the sequential tunneling current exhibits a spin satellite peak whose
+linewidth gives a lower bound on the decoherence time T_2 of the dot-spin.
+Similarly, the spin decoherence can be accessed also in the cotunneling regime
+via ESR induced spin flips. We show that the conductance ratio of the spin
+satellite peak and the conventional peak due to sequential tunneling saturates
+at the universal conductance ratio of 0.71 for strong ESR fields. We describe a
+double-dot setup which generates spin dependent tunneling and acts as a current
+pump (at zero bias), and as a spin inverter which inverts the spin-polarization
+of the current. We show that Rabi oscillations of the dot-spin induce coherent
+oscillations in the time-dependent current. These oscillations are observable
+in the time-averaged current as function of ESR pulse-duration, and they allow
+one to access the spin coherence directly in the time domain. We analyze the
+measurement and read-out process of the dot-spin via currents in spin-polarized
+leads and identify measurement time and efficiency by calculating the counting
+statistics, noise, and the Fano factor.",0109470v1
+2002-11-10,Tortuosity Measurement and the Effects of Finite Pulse Widths on Xenon Gas Diffusion NMR Studies of Porous Media,"We have extended the utility of NMR as a technique to probe porous media
+structure over length scales of ~ 100 - 2000 micron by using the spin 1/2 noble
+gas 129Xe imbibed into the system's pore space. Such length scales are much
+greater than can be probed with NMR diffusion studies of water-saturated porous
+media. We utilized Pulsed Gradient Spin Echo NMR measurements of the
+time-dependent diffusion coefficient, D(t) of the xenon gas filling the pore
+space to study further the measurements of both the surface area-pore volume
+ratio, S/Vp, and the tortuosity (pore connectivity) of the medium. In
+uniform-size glass bead packs, we observed D(t) decreasing with increasing t,
+reaching an observed asymptote of ~ 0.62 - 0.65D0, that could be measured over
+diffusion distances extending over multiple bead diameters. Measurements of
+D(t)/D0 at differing gas pressures showed this tortuosity limit was not
+affected by changing the characteristic diffusion length of the spins during
+the diffusion encoding gradient pulse. This was not the case at the short time
+limit, where D(t)/D0 was noticeably affected by the gas pressure in the sample.
+Increasing the gas pressure, and hence reducing D0 and the diffusion during the
+gradient pulse served to reduce the previously observed deviation of D(t)/D0
+from the S/Vp relation. The Pade approximation is used to interpolate between
+the long and short time limits in D(t). While the short time D(t) point lay
+above the interpolation line in the case of small beads, due to diffusion
+during the gradient pulse on the order of the pore size, it was also noted that
+the experimental D(t) data fell below the Pade line in the case of large beads,
+most likely due to finite size effects.",0211184v1
+2005-06-30,AC Conductance in Dense Array of the Ge$_{0.7}$Si$_{0.3}$ Quantum Dots in Si,"Complex AC-conductance, $\sigma^{AC}$, in the systems with dense
+Ge$_{0.7}$Si$_{0.3}$ quantum dot (QD) arrays in Si has been determined from
+simultaneous measurements of attenuation, $\Delta\Gamma=\Gamma(H)-\Gamma(0)$,
+and velocity, $\Delta V /V=(V(H)-V(0)) / V(0)$, of surface acoustic waves (SAW)
+with frequencies $f$ = 30-300 MHz as functions of transverse magnetic field $H
+\leq$ 18 T in the temperature range $T$ = 1-20 K. It has been shown that in the
+sample with dopant (B) concentration 8.2$ \times 10^{11}$ cm$^{-2}$ at
+temperatures $T \leq$4 K the AC conductivity is dominated by hopping between
+states localized in different QDs. The observed power-law temperature
+dependence, $\sigma_1(H=0)\propto T^{2.4}$, and weak frequency dependence,
+$\sigma_1(H=0)\propto \omega^0$, of the AC conductivity are consistent with
+predictions of the two-site model for AC hopping conductivity for the case of
+$\omega \tau_0 \gg $1, where $\omega=2\pi f$ is the SAW angular frequency and
+$\tau_0$ is the typical population relaxation time. At $T >$ 7 K the AC
+conductivity is due to thermal activation of the carriers (holes) to the
+mobility edge. In intermediate temperature region 4$ < T<$ 7 K, where AC
+conductivity is due to a combination of hops between QDs and diffusion on the
+mobility edge, one succeeded to separate both contributions. Temperature
+dependence of hopping contribution to the conductivity above $T^*\sim$ 4.5 K
+saturates, evidencing crossover to the regime where $\omega \tau_0 < $1. From
+crossover condition, $\omega \tau_0(T^*)$ = 1, the typical value, $\tau_0$, of
+the relaxation time has been determined.",0506800v1
+2007-04-24,Rotation and activity of pre-main-sequence stars,"We present a study of rotation (vsini) and chromospheric activity (Halpha EW)
+based on an extensive set of high-resolution optical spectra obtained with MIKE
+on the 6.5m Magellan Clay telescope. Our targets are 74 F-M dwarfs in the young
+stellar associations Eta Cha, TW Hydrae, Beta Pic, and Tuc-Hor, spanning ages
+from 6 to 30 Myr. While the Halpha EW for most F and G stars are consistent
+with pure photospheric absorption, most K and M stars show chromospheric
+emission. By comparing Halpha EW in our sample to results in the literature, we
+see a clear evolutionary sequence: Chromospheric activity declines steadily
+from the T Tauri phase to the main sequence. Using activity as an age
+indicator, we find a plausible age range for the Tuc-Hor association of 10-40
+Myr. Between 5 and 30 Myr, we do not see evidence for rotational braking in the
+total sample, thus angular momentum is conserved, in contrast to younger stars.
+This difference indicates a change in the rotational regulation at 5-10 Myr,
+possibly because disk braking cannot operate longer than typical disk
+lifetimes, allowing the objects to spin up. The rotation-activity relation is
+flat in our sample; in contrast to main-sequence stars, there is no linear
+correlation for slow rotators. We argue that this is because young stars
+generate their magnetic fields in a fundamentally different way from
+main-sequence stars, and not just the result of a saturated solar-type dynamo.
+By comparing our rotational velocities with published rotation periods for a
+subset of stars, we determine ages of 13 (7-20) Myr and 9 (7-17} Myr for the
+Eta Cha and TWA associations, respectively, consistent with previous estimates.
+Thus we conclude that stellar radii from evolutionary models by Baraffe et al.
+(1998) are in agreement with the observed radii within +-15%. (abridged)",0704.3266v1
+2009-01-07,Synthesis and characterization of single phase Mn doped ZnO,"Different samples of Zn1-xMnxO series have been prepared by conventional
+solid state sintering method. It has been identified, up to what extent of
+doping enable us to synthesize single-phase polycrystalline Mn doped ZnO
+samples which is one of the prerequisite for dilute magnetic semiconductor and
+we have analyzed its certain other physical aspects. In synthesizing the
+samples proportion of Mn varies from 1 at% to 5 at%. However the milling times
+have been varied (6, 12, 24, 48 & 96 hours) for only 2 at% Mn doped samples
+while for other samples (1, 3, 4 & 5 at% Mn doped) the milling time has been
+kept fixed at 96 hours. Room temperature X-Ray diffraction (XRD) data reveal
+that all of the prepared samples up to 3 at% of Mn doping exhibit wurtzite-type
+structure, no segregation of Mn and/or its oxides has been found. The 4 at% Mn
+doped samples show a weak peak of ZnMn2O4 apart from usual other peaks of ZnO
+and the intensity of this impurity peak has been further increased for 5 at% of
+Mn doping. So beyond 3 at% doping single-phase behavior is destroyed. Band gap
+for all the 2 at% Mn doped samples have been estimated as between 3.21 to 3.19
+eV and reason for this low band gap values has been explained through the grain
+boundary trapping model. The room temperature resistivity measurement shows
+increase of resistivity up to 48 hours of milling and with further milling it
+saturates. The defect state of these samples has been investigated by using
+positron annihilation lifetime (PAL) spectroscopy technique. Here all the
+relevant lifetime parameters of positron i.e. free annihilation (tau 1), at
+defect site (tau 2) and average (tau av) increases with milling time.",0901.0807v1
+2009-01-12,Planet formation bursts at the borders of the dead zone in 2D numerical simulations of circumstellar disks,"As accretion in protoplanetary disks is enabled by turbulent viscosity, the
+border between active and inactive (dead) zones constitutes a location where
+there is an abrupt change in the accretion flow. The gas accumulation that
+ensues triggers the Rossby wave instability, that in turn saturates into
+anticyclonic vortices. It was suggested that the trapping of solids within them
+leads to a burst of planet formation on very short timescales. We perform
+two-dimensional global simulations of the dynamics of gas and solids in a
+non-magnetized thin protoplanetary disk with the Pencil Code. We use multiple
+particle species of radius 1, 10, 30, and 100 cm, solving for the particles'
+gravitational interaction by a particle-mesh method. The dead zone is modeled
+as a region of low viscosity. Adiabatic and locally isothermal equations of
+state are used. We find that the Rossby wave instability is triggered under a
+variety of conditions, thus making vortex formation a robust process. Inside
+the vortices, fast accumulation of solids occurs and the particles collapse
+into objects of planetary mass in timescales as short as five orbits. Because
+the drag force is size-dependent, aerodynamical sorting ensues within the
+vortical motion, and the first bound structures formed are composed primarily
+of similarly-sized particles. In addition to erosion due to ram pressure, we
+identify gas tides from the massive vortices as a disrupting agent of formed
+protoplanetary embryos. We also estimate the collisional velocity history of
+the particles that compose the most massive embryo by the end of the
+simulation, finding that the vast majority of them never experienced a
+collision with another particle at speeds faster than 1 m/s.",0901.1638v4
+2011-03-03,Chromospheric Activities and Kinematics for Solar Type Dwarfs and Subgiants: Analysis of the Activity Distribution and the AVR,"In this work we present chromospheric activity indices, kinematics,
+radial-velocities and rotational velocities for more than 850 FGK-type dwarfs
+and subgiant stars in the southern hemisphere and test how best to calibrate
+and measure S-indices from echelle spectra. We confirm the bimodal distribution
+of chromospheric activities for such stars and highlight the role that the more
+active K-dwarfs play in biasing the number of active stars. We show that the
+age-activity relationship does appear to continue to ages older than the Sun if
+we simply compare main sequence stars and subgiant stars, with an offset of
+around 2.5 Gyrs between the peaks of both distributions. Also we show evidence
+for an increased spin-down timescale for cool K dwarfs compared with earlier F
+and G type stars. In addition, we show how kinematics can be used to preselect
+inactive stars for future planet search projects. We see the well known trend
+between projected rotational velocity and activity, however we also find a
+correlation between kinematic space velocity and chromospheric activity. It
+appears that after the Vaughan-Preston gap there is a quick step function in
+the kinematic space motion towards a significantly larger spread in velocities.
+We speculate on reasons for this correlation and provide some model scenarios
+to describe the bimodal activity distribution through magnetic saturation,
+residual low level gas accretion or accretion by the star of planets or
+planetesimals. Finally, we provide a new empirical measurement for the disk
+heating law, using the latest age-activity relationships to reconstruct the
+age-velocity distribution for local disk stars. We find a value of
+0.337+/-0.045 for the exponent of this power law (i.e. sigma_tot proportional
+to t^0.337), in excellent agreement with those found using isochrone fitting
+methods and with theoretical disk heating models. [Abridged]",1103.0584v1
+2011-07-21,Glueballs in large-N YM by localization on critical points,"By exploiting in large-N YM the change of variables from the gauge connection
+to the ASD part of its curvature by a non-SUSY version of the Nicolai map, we
+show that certain twistor Wilson loops supported on a Lagrangian submanifold of
+twistor space are localized on lattices of surface operators of Z(N) holonomy
+that form translational invariant sectors labelled by the magnetic charge
+k=1,2,...,N-1 at a point. The localization is obtained reducing the loop
+equation in the ASD variables in the holomorphic gauge, regularized by analytic
+continuation to Minkowski space-time, to a critical equation, by exploiting the
+invariance of the twistor Wilson loops by deformations for the addition of
+backtracking arcs ending with cusps on the singular divisor of surface
+operators. Alternatively localization is obtained contracting the YM measure in
+the ASD variables on the fixed points of a semigroup that acts on the fiber of
+the Lagrangian twistor fibration which twistor Wilson loops are supported on
+and leaves invariant their v.e.v.. The masses squared of the fluctuations of
+surface operators in the sectors labelled by k, supported on the Lagrangian
+submanifold analytically continued to Minkowski space-time, form a trajectory
+linear in k that does not include any massless state. The glueballs propagators
+in the holomorphic/antiholomorphic sector defined by correlators of a complex
+combination of the ASD curvature and its adjoint saturate at short distances
+the logarithms of perturbation theory by a sum of pure poles. In this framework
+Regge trajectories of higher spins are related to fluctuations of surface
+operators with pole singularities of any order.",1107.4320v4
+2012-05-10,Mid-Infrared Extinction Mapping of Infrared Dark Clouds II. The Structure of Massive Starless Cores and Clumps,"(abridged) We develop the mid-infrared extinction (MIREX) mapping technique
+of Butler & Tan (2009, Paper I), presenting a new method to correct for the
+Galactic foreground emission based on observed saturation in independent cores.
+Using Spitzer GLIMPSE 8 micron images, this allows us to accurately probe mass
+surface densities, Sigma, up to ~0.5g/cm^2 with 2"" resolution. We then
+characterize the structure of 42 massive starless and early-stage IRDC cores
+and their surrounding clumps, measuring Sigma_cl(r) from the core/clump
+centers. We first assess the properties of the core/clump at a scale where the
+total enclosed mass as projected on the sky is M_cl=60Msun. We find these
+objects have a mean radius of R_cl~0.1pc, mean Sigma_cl=0.3g/cm^2 and, if fit
+by a power law density profile rho_cl ~ r^{-k_{rho,cl}}, a mean value of
+k_{rho,cl}=1.1. If we assume a core is embedded in each clump and subtract the
+surrounding clump envelope to derive the core properties, we find a mean core
+density power law index of k_{rho,c} = 1.6. We repeat this analysis as a
+function of radius and derive the best-fitting power law plus uniform clump
+envelope model for each of the 42 core/clumps. The cores have typical masses of
+M_c~100Msun and mean Sigma_c~0.1g/cm^2, and are embedded in clumps with
+comparable mass surface densities. We conclude massive starless cores exist and
+are well-described by singular polytropic spheres. Their relatively low values
+of Sigma and the fact that they are IR dark may imply that their fragmentation
+is inhibited by magnetic fields rather than radiative heating. Comparing to
+massive star-forming cores, there is tentative evidence for an evolution
+towards higher densities and steeper density profiles as star formation
+proceeds.",1205.2391v1
+2013-02-05,The UV and X-ray activity of the M dwarfs within 10pc of the Sun,"We systematically study the X-ray and ultraviolet emission of a subsample of
+M dwarfs from a recent proper-motion survey, selecting all M dwarfs within 10pc
+to obtain a nearly volume-limited sample (~90% completeness). Archival ROSAT,
+XMM-Newton and GALEX data are combined with published spectroscopic studies of
+Halpha emission and rotation to obtain a broad picture of stellar activity on M
+dwarfs. We make use of synthetic model spectra to determine the relative
+contributions of photospheric and chromospheric emission to the ultraviolet
+flux. We also analyse the same diagnostics for a comparison sample of young M
+dwarfs in the TWHya association (~10Myrs). We find that generally the emission
+in the GALEX bands is dominated by the chromosphere but the photospheric
+component is not negligible in early-M field dwarfs. The surface fluxes for the
+Halpha, near-ultraviolet, far-ultraviolet and X-ray emission are connected via
+a power law dependence. We present here for the first time such flux-flux
+relations involving broad-band ultraviolet emission for M dwarfs. For given
+spectral type the activity indices, defined as flux ratio between the activity
+diagnostic and the bolometric flux of the star, display a spread of 2-3 dex
+which is largest for M4 stars. The mean activity index for fast rotators,
+likely representing the saturation level, decreases from X-rays over the FUV to
+the NUV band and Halpha, i.e. the fractional radiation output increases with
+atmospheric height. The comparison to the ultraviolet and X-ray properties of
+TWHya members shows a drop of nearly three orders of magnitude for the
+luminosity in these bands between ~10Myr and few Gyrs age. A few young field
+dwarfs (< 1Gyr) in the 10pc sample bridge the gap indicating that the drop in
+magnetic activity with age is a continuous process. The slope of the age decay
+is steeper for the X-ray than for the UV luminosity.",1302.1061v1
+2014-03-05,Bond disorder and spinon heat transport in the $S=\tfrac{1}{2}$ Heisenberg spin chain compound Sr$_2$CuO$_3$: from clean to dirty limits,"We investigate the effect of disorder on the heat transport properties of the
+$S=\tfrac{1}{2}$ Heisenberg chain compound Sr$_2$CuO$_3$ upon chemically
+substituting Sr by increasing concentrations of Ca. As Ca occupies sites
+outside but near the Cu-O-Cu spin chains, bond disorder, i.e. a spatial
+variation of the exchange interaction $J$, is expected to be realized in these
+chains. We observe that the magnetic heat conductivity
+($\kappa_{\mathrm{mag}}$) due to spinons propagating in the chains is gradually
+but strongly suppressed with increasing amount of Ca, where the doping
+dependence can be understood in terms of increased scattering of spinons due to
+Ca-induced disorder. This is also reflected in the spinon mean free path which
+can be separated in a doping independent but temperature dependent scattering
+length due to spinon-phonon scattering, and a temperature independent but
+doping dependent spinon-defect scattering length. The latter spans from very
+large ($>$ 1300 lattice spacings) to very short ($\sim$ 12 lattice spacings)
+and scales with the average distance between two neighboring Ca atoms. Thus,
+the Ca-induced disorder acts as an effective defect within the spin chain, and
+the doping scheme allows to cover the whole doping regime between the clean and
+the dirty limits. Interestingly, at maximum impurity level we observe, in
+Ca-doped Sr$_2$CuO$_3$, an almost linear increase of $\kappa_{\mathrm{mag}}$ at
+temperatures above 100 K which reflects the intrinsic low temperature behavior
+of heat transport in a Heisenberg spin chain. These findings are quite
+different from that observed for the Ca-doped double spin chain compound,
+SrCuO$_2$, where the effect of Ca seems to saturate already at intermediate
+doping levels.",1403.1145v2
+2014-09-26,The Factory and The Beehive II. Activity and Rotation in Praesepe and the Hyades,"Open clusters are collections of stars with a single, well-determined age,
+and can be used to investigate the connections between angular-momentum
+evolution and magnetic activity over a star's lifetime. We present the results
+of a comparative study of the relationship between stellar rotation and
+activity in two benchmark open clusters: Praesepe and the Hyades. As they have
+the same age and roughly solar metallicity, these clusters serve as an ideal
+laboratory for testing the agreement between theoretical and empirical
+rotation-activity relations at $\approx$600 Myr. We have compiled a sample of
+720 spectra --- more than half of which are new observations --- for 516
+high-confidence members of Praesepe; we have also obtained 139 new spectra for
+130 high-confidence Hyads. We have collected rotation periods ($P_{rot}$) for
+135 Praesepe members and 87 Hyads. To compare $H\alpha$ emission, an indicator
+of chromospheric activity, as a function of color, mass, and Rossby number
+$R_o$, we first calculate an expanded set of $\chi$ values, with which we can
+obtain the $H\alpha$ to bolometric luminosity ratio, $L_{H\alpha}/L_{bol}$,
+even when spectra are not flux-calibrated and/or stars lack reliable distances.
+Our $\chi$ values cover a broader range of stellar masses and colors (roughly
+equivalent to spectral types from K0 to M9), and exhibit better agreement
+between independent calculations, than existing values. We find no difference
+between the two clusters in their $H\alpha$ equivalent width or
+$L_{H\alpha}/L_{bol}$ distributions, and therefore take the merged $H\alpha$
+and $P_{rot}$ data to be representative of 600-Myr-old stars. Our analysis
+shows that $H\alpha$ activity in these stars is saturated for
+$R_o\leq0.11^{+0.02}_{-0.03}$. Above that value activity declines as a
+power-law with slope $\beta=-0.73^{+0.16}_{-0.12}$, before dropping off rapidly
+at $R_o\approx0.4$...",1409.7603v1
+2015-01-01,Motivation and challenge to capture both large scale and local transport in next generation accretion theory,"Accretion disc theory is less developed than stellar evolution theory
+although a similarly mature phenomenological picture is ultimately desired.
+While the interplay of theory and numerical simulations has amplified community
+awareness of the role of magnetic fields in angular momentum transport, there
+remains a long term challenge to incorporate insight gained from simulations
+back into improving practical models for comparison with observations. Here we
+emphasize the need to incorporate the role of non-local transport more
+precisely. To show where large scale transport would fit into the theoretical
+framework and how it is currently missing, we review why the wonderfully
+practical approach of Shakura-Sunyaev (1973,SS73) is necessarily a mean field
+theory, and one which does not include large scale transport. Observations of
+coronae and jets combined with the interpretation of results even from shearing
+box simulations of the magnetorotational instability (MRI) suggest that a
+significant fraction of disc transport is indeed non-local. We show that the
+Maxwell stresses in saturation are dominated by large scale contributions and
+the physics of MRI transport is not fully captured by a viscosity. We also
+clarify the standard physical interpretation of the MRi as it applies to
+shearing boxes. Computational limitations have so far focused most attention
+toward local simulations but the next generation of global simulations should
+help to inform improved mean field theories. Mean field accretion theory and
+mean field dynamo theory should in fact be unified into a single theory that
+predicts the time evolution of spectra and luminosity from separate disc,
+corona, and outflow contributions. Finally, we note that any mean field theory
+has a finite predictive precision that needs to be quantified when comparing
+the predictions to observations.",1501.00291v4
+2015-06-27,Theory of the nonlinear Rashba-Edelstein effect,"It is well known that a current driven through a two-dimensional electron gas
+with Rashba spin-orbit coupling induces a spin polarization in the
+perpendicular direction (Edelstein effect). This phenomenon has been
+extensively studied in the linear response regime, i.e., when the average drift
+velocity of the electrons is a small fraction of the Fermi velocity. Here we
+investigate the phenomenon in the nonlinear regime, meaning that the average
+drift velocity is comparable to, or exceeds the Fermi velocity. This regime is
+realized when the electric field is very large, or when electron-impurity
+scattering is very weak. The quantum kinetic equation for the density matrix of
+noninteracting electrons is exactly and analytically solvable, reducing to a
+problem of spin dynamics for ""unpaired"" electrons near the Fermi surface. The
+crucial parameter is $\gamma=eEL_s/E_F$, where $E$ is the electric field, $e$
+is the absolute value of the electron charge, $E_F$ is the Fermi energy, and
+$L_s = \hbar/(2m\alpha)$ is the spin-precession length in the Rashba spin-orbit
+field with coupling strength $\alpha$. If $\gamma\ll1$ the evolution of the
+spin is adiabatic, resulting in a spin polarization that grows monotonically in
+time and eventually saturates at the maximum value $n(\alpha/v_F)$, where $n$
+is the electron density and $v_F$ is the Fermi velocity. If $\gamma \gg 1$ the
+evolution of the spin becomes strongly non-adiabatic and the spin polarization
+is progressively reduced, and eventually suppressed for $\gamma\to \infty$. We
+also predict an inverse nonlinear Edelstein effect, in which an electric
+current is driven by a magnetic field that grows linearly in time. The
+""conductivities"" for the direct and the inverse effect satisfy generalized
+Onsager reciprocity relations, which reduce to the standard ones in the linear
+response regime.",1506.08330v1
+2015-09-04,Standing Sausage Modes In Nonuniform Magnetic Tubes: An Inversion Scheme For Inferring Flare Loop Parameters,"Standing sausage modes in flare loops are important for interpreting
+quasi-periodic pulsations (QPPs) in solar flare lightcurves. We propose an
+inversion scheme that consistently uses their periods $P$ and damping times
+$\tau$ to diagnose flare loop parameters. We derive a generic dispersion
+relation governing linear sausage waves in pressure-less straight tubes, for
+which the transverse density inhomogeneity takes place in a layer of arbitrary
+width $l$ and is of arbitrary form. We find that $P$ and $\tau$ depend on the
+combination of $[R/v_{\rm Ai}, L/R, l/R, \rho_{\rm i}/\rho_{\rm e}]$, where $R$
+is the loop radius, $L$ is the looplength, $v_{\rm Ai}$ is the internal
+Alfv\'en speed, and $\rho_{\rm i}/\rho_{\rm e}$ is the density contrast. For
+all the density profiles examined, $P$ and $\tau$ experience saturation when
+$L/R \gg 1$, yielding an inversion curve in the $[R/v_{\rm Ai}, l/R, \rho_{\rm
+i}/\rho_{\rm e}]$ space with a specific density profile when $L/R$ is
+sufficiently large. When applied to a spatially unresolved QPP event, the
+scheme yields that $R/v_{\rm Ai}$ is the best constrained, whereas $l/R$
+corresponds to the other extreme. For spatially resolved QPPs, while $L/R \gg
+1$ cannot be assumed beforehand, an inversion curve remains possible due to
+additional geometrical constraints. When a spatially resolved QPP event
+involves another mode, as is the case for a recent event, the full set of
+$[v_{\rm Ai}, l, \rho_{\rm i}/\rho_{\rm e}]$ can be inferred. We conclude that
+the proposed scheme provides a useful tool for magneto-seismologically
+exploiting QPPs.",1509.01442v1
+2015-09-22,Quantum Simulations of Nuclei and Nuclear Pasta with the Multi-resolution Adaptive Numerical Environment for Scientific Simulations,"Neutron star and supernova matter at densities just below the nuclear matter
+saturation density is expected to form a lattice of exotic shapes. These
+so-called nuclear pasta phases are caused by Coulomb frustration. Their elastic
+and transport properties are believed to play an important role for thermal and
+magnetic field evolution, rotation and oscillation of neutron stars.
+Furthermore, they can impact neutrino opacities in core-collapse supernovae. In
+this work, we present proof-of-principle 3D Skyrme Hartree-Fock (SHF)
+simulations of nuclear pasta with the Multi-resolution ADaptive Numerical
+Environment for Scientific Simulations (MADNESS). We perform benchmark studies
+of $^{16} \mathrm{O}$, $^{208} \mathrm{Pb}$ and $^{238} \mathrm{U}$ nuclear
+ground states and calculate binding energies via 3D SHF simulations. Results
+are compared with experimentally measured binding energies as well as with
+theoretically predicted values from an established SHF code. The nuclear pasta
+simulation is initialized in the so-called waffle geometry as obtained by the
+Indiana University Molecular Dynamics (IUMD) code. The size of the unit cell is
+24\:fm with an average density of about $\rho = 0.05 \:\mathrm{fm}^{-3}$,
+proton fraction of $Y_p = 0.3$ and temperature of $T=0\:$MeV. Our calculations
+reproduce the binding energies and shapes of light and heavy nuclei with
+different geometries. For the pasta simulation, we find that the final geometry
+is very similar to the initial waffle state. In the present pasta calculations
+spin-orbit forces are not included but will be added in the future. Within the
+MADNESS framework, we can successfully perform calculations of inhomogeneous
+nuclear matter. By using pasta configurations from IUMD it is possible to
+explore different geometries and test the impact of self-consistent
+calculations on the latter.",1509.06671v2
+2015-12-08,The nature of the electrical conduction in ferromagnetic atomic-size contacts: insights from shot noise measurements and theoretical simulations,"With the goal to elucidate the nature of spin-dependent electronic transport
+in ferromagnetic atomic contacts, we present here a combined experimental and
+theoretical study of the conductance and shot noise of metallic atomic contacts
+made of the 3d ferromagnetic materials Fe, Co, and Ni. For comparison, we also
+present the corresponding results for the noble metal Cu. Conductance and shot
+noise measurements, performed using a low-temperature break junction setup,
+show that in these ferromagnetic nanowires: (i) there is no conductance
+quantization of any kind, (ii) transport is dominated by several partially-open
+conduction channels, even in the case of single-atom contacts, and (iii) the
+Fano factor of large contacts saturates to values that clearly differs from
+those of monovalent (nonmagnetic) metals. We rationalize these observations
+with the help of a theoretical approach that combines molecular dynamics
+simulations to describe the junction formation with nonequilibrium Green's
+function techniques to compute the transport properties within the
+Landauer-Buettiker framework. Our theoretical approach successfully reproduces
+all the basic experimental results and it shows that all the observations can
+be traced back to the fact that the d bands of the minority-spin electrons play
+a fundamental role in the transport through ferromagnetic atomic-size contacts.
+These d bands give rise to partially open conduction channels for any contact
+size, which in turn lead naturally to the different observations described
+above. Thus, the transport picture for these nanoscale ferromagnetic wires that
+emerges from the ensemble of our results is clearly at variance with the well
+established conduction mechanism that governs the transport in macroscopic
+ferromagnetic wires, where the d bands are responsible for the magnetism but do
+not take part in the charge flow.",1512.02601v1
+2016-03-28,The Efficiency of Magnetic Field Amplification at Shocks by Turbulence,"Turbulent dynamo field amplification has often been invoked to explain the
+strong field strengths in thin rims in supernova shocks ($\sim 100 \, \mu$G)
+and in radio relics in galaxy clusters ($\sim \mu$G). We present high
+resolution MHD simulations of the interaction between pre-shock turbulence,
+clumping and shocks, to quantify the conditions under which turbulent dynamo
+amplification can be significant. We demonstrate numerically converged field
+amplification which scales with Alfv\'en Mach number, $B/B_0 \propto {\mathcal
+M}_{\rm A}$, up to ${\mathcal M}_{\rm A} \sim 150$. This implies that the
+post-shock field strength is relatively independent of the seed field.
+Amplification is dominated by compression at low ${\mathcal M}_{\rm A}$, and
+stretching (turbulent amplification) at high ${\mathcal M}_{\rm A}$. For high
+$\mathcal{M}_{\rm A}$, the $B$-field grows exponentially and saturates at
+equipartition with turbulence, while the vorticity jumps sharply at the shock
+and subsequently decays; the resulting field is orientated predominately along
+the shock normal (an effect only apparent in 3D and not 2D). This agrees with
+the radial field bias seen in supernova remnants. By contrast, for low
+$\mathcal{M}_{\rm A}$, field amplification is mostly compressional, relatively
+modest, and results in a predominantly perpendicular field. The latter is
+consistent with the polarization seen in radio relics. Our results are
+relatively robust to the assumed level of gas clumping. Our results imply that
+the turbulent dynamo may be important for supernovae, but is only consistent
+with the field strength, and not geometry, for cluster radio relics. For the
+latter, this implies strong pre-existing $B$-fields in the ambient cluster
+outskirts.",1603.08518v2
+2016-04-04,Ferro-deformation and shape phase transitions over the nuclear chart: 50 < protons (Z) < 82 and 50 < neutrons (N) < 126,"We study a global nuclear structure in the framework of experimental
+observables. With the aid of large nuclear structure data at the national
+nuclear data center, NNDC, we present the distinctive systematic patterns
+emerged in the first 2+ excited energies, E(2+) and their energy ratios to the
+first 4+ levels, R = E(4+)/E(2+), in the even-even nuclei, over 50 < Z < 82 for
+protons, and 50 < N < 126 for neutrons. We introduce the so-called pseudo-shell
+configurations from the subshells mixture in order to explain a semi-double
+shell closure, a shape phase transition, and a reinforced deformation. It is
+found that the reinforced deformation arises when Z = 64 or 66 correlates with
+N = 90 and reaches its maximum, indicating R = 3.3. Such a saturated reinforced
+deformation spans over Z = 58 to 72 and N = 100 to 106 as showing its center at
+Z = 64 or 66 and at N = 102 or 104. We define this reinforced deformation 'a
+ferro-deformation' like a ferro-magnetism in condensed matter physics. The
+shape coexistence would be expected to occur, such as a ferro-deformation, with
+a strong rotational mode, and a near spherical shape, with a vibrational mode,
+at the critical points of Z = 64 or 66, with N = 88 and 90; 150Sm and 152Sm,
+152Gd and 154Gd, and 154Dy and 156Dy. We suggest that a super-deformation,
+which can be formed at high-lying excited states in a moderate deformed
+nucleus, would correspond to the ferro-deformation at N = 88 for the nuclei;
+Sm, Gd, and Dy. We argue that the ferro-deformation can be closely associated
+with a strong spin-orbital interaction between neutrons and protons in the
+spin-orbit doublet, h9/2-h11/2, leading to the critical points at Z, N = 64,
+104.",1604.01017v1
+2016-04-19,Evidence for Cluster to Cluster Variations in Low-Mass Stellar Rotational Evolution,"A concordance model for angular momentum evolution has been developed by
+multiple investigators. This approach postulates that star forming regions and
+clusters are an evolutionary sequence which can be modeled with assumptions
+about the coupling between protostars and accretion disks, angular momentum
+loss from magnetized winds that saturates in a mass-dependent fashion at high
+rotation rates, and core-envelope decoupling for solar analogs. We test this
+approach by combining established data with the large h Per dataset from the
+MONITOR project and new low-mass Pleiades data. We confirm prior results that
+young low-mass stars can be used to test star-disk coupling and angular
+momentum loss independent of the treatment of internal angular momentum
+transport. For slow rotators, we confirm the need for star-disk interactions to
+evolve the ONC to older systems, using h Per (age 13~Myr) as our natural
+post-disk case. Further interactions are not required to evolve slow rotators
+from h Per to older systems, implying no justification for extremely long-lived
+disks as an alternative to core-envelope decoupling. However, our wind models
+cannot evolve rapid rotators from h Per to older systems consistently; this
+appears to be a general problem for any wind model that becomes ineffective in
+low-mass young stars. We outline two possible solutions: either there is cosmic
+variance in the distribution of stellar rotation rates in different clusters or
+there are substantially enhanced torques in low-mass rapid rotators. We favor
+the former explanation and discuss observational tests that could be used to
+distinguish them. If the distribution of initial conditions depends on
+environment, models which test parameters by assuming a universal underlying
+distribution of initial conditions will need to be re-evaluated.",1604.05729v1
+2016-07-15,The Aerogel Cherenkov Detector for the SHMS magnetic spectrometer in Hall C at Jefferson Lab,"Hadronic reactions producing strange quarks such as exclusive or
+semi-inclusive kaon production, play an important role in studies of hadron
+structure and the dynamics that bind the most basic elements of nuclear
+physics. The small-angle capability of the new Super High Momentum Spectrometer
+(SHMS) in Hall C, coupled with its high momentum reach - up to the anticipated
+11-GeV beam energy in Hall C - and coincidence capability with the
+well-understood High Momentum Spectrometer, will allow for probes of such
+hadron structure involving strangeness down to the smallest distance scales to
+date. To cleanly select the kaons, a threshold aerogel Cerenkov detector has
+been constructed for the SHMS. The detector consists of an aerogel tray
+followed by a diffusion box. Four trays for aerogel of nominal refractive
+indices of n=1.030, 1.020, 1.015 and 1.011 were constructed. The tray
+combination will allow for identification of kaons from 1 GeV/c up to 7.2
+GeV/c, reaching 10^-2 proton and 10^-3 pion rejection, with kaon detection
+efficiency better than 95%. The diffusion box of the detector is equipped with
+14 five-inch diameter photomultiplier tubes. Its interior walls are covered
+with Gore diffusive reflector, which is superior to the commonly used Millipore
+paper and improved the detector performance by 35%. The inner surface of the
+two aerogel trays with higher refractive index is covered with Millipore paper,
+however, those two trays with lower aerogel refractive index are again covered
+with Gore diffusive reflector for higher performance. The measured mean number
+of photoelectrons in saturation is ~12 for n=1.030, ~sim8 for n=1.020, ~10 for
+n=1.015, and ~5.5 for n=1.011. The design details, the results of component
+characterization, and initial performance tests and optimization of the
+detector are presented.",1607.05264v1
+2016-08-17,Kinematics of the jet in M87 on scales of 100 -- 1000 Schwarzschild radii,"Very long baseline interferometry (VLBI) imaging of radio emission from
+extragalactic jets provides a unique probe of physical mechanisms governing the
+launching, acceleration, and collimation of relativistic outflows. The
+two-dimensional structure and kinematics of the jet in M\,87 (NGC\,4486) have
+been studied by applying the Wavelet-based Image Segmentation and Evaluation
+(WISE) method to 11 images obtained from multi-epoch Very Long Baseline Array
+(VLBA) observations made in January-August 2007 at 43 GHz ($\lambda = 7$ mm).
+The WISE analysis recovers a detailed two-dimensional velocity field in the jet
+in M\,87 at sub-parsec scales. The observed evolution of the flow velocity with
+distance from the jet base can be explained in the framework of MHD jet
+acceleration and Poynting flux conversion. A linear acceleration regime is
+observed up to $z_{obs} \sim 2$\,mas. The acceleration is reduced at larger
+scales, which is consistent with saturation of Poynting flux conversion.
+Stacked cross correlation analysis of the images reveals a pronounced
+stratification of the flow. The flow consists of a slow, mildly relativistic
+layer (moving at $\beta \sim 0.5\,c$), associated either with instability
+pattern speed or an outer wind, and a fast, accelerating stream line (with
+$\beta \sim 0.92$, corresponding to a bulk Lorentz factor $\gamma \sim 2.5$). A
+systematic difference of the apparent speeds in the northern and southern limbs
+of the jet is detected, providing evidence for jet rotation. The angular
+velocity of the magnetic field line associated with this rotation suggests that
+the jet in M87 is launched in the inner part of the disk, at a distance $r_0
+\sim 5\, R_\mathrm{s}$ from the central engine. The combined results of the
+analysis imply that MHD acceleration and conversion of Poynting flux to kinetic
+energy play the dominant roles in collimation and acceleration of the flow in
+M\,87.",1608.05063v1
+2017-03-02,Analysis of the flux growth rate in emerging active regions on the Sun,"We studied the emergence process of 42 active region (ARs) by analyzing the
+time derivative, R(t), of the total unsigned flux. Line-of-sight magnetograms
+acquired by the Helioseismic and Magnetic Imager (HMI) onboard the Solar
+Dynamics Observatory (SDO) were used. A continuous piecewise linear fitting to
+the R(t)-profile was applied to detect an interval, dt_2, of nearly-constant
+R(t) covering one or several local maxima. The averaged over dt_2 magnitude of
+R(t) was accepted as an estimate of the maximal value of the flux growth rate,
+R_MAX, which varies in a range of (0.5-5)x10^20 Mx hour^-1 for active regions
+with the maximal total unsigned flux of (0.5-3)x10^22 Mx. The normalized flux
+growth rate, R_N, was defined under an assumption that the saturated total
+unsigned flux, F_MAX, equals unity. Out of 42 ARs in our initial list, 36 event
+were successfully fitted and they form two subsets (with a small overlap of 8
+events): the ARs with a short (<13 hours) interval dt_2 and a high (>0.024
+hour^-1) normalized flux emergence rate, R_N, form the ""rapid"" emergence event
+subset. The second subset consists of ""gradual"" emergence events and it is
+characterized by a long (>13 hours) interval dt_2 and a low R_N (<0.024
+hour^-1). In diagrams of R_MAX plotted versus F_MAX, the events from different
+subsets are not overlapped and each subset displays an individual power law.
+The power law index derived from the entire ensemble of 36 events is
+0.69+-0.10. The ""rapid"" emergence is consistent with a ""two-step"" emergence
+process of a single twisted flux tube. The ""gradual"" emergence is possibly
+related to a consecutive rising of several flux tubes emerging at nearly the
+same location in the photosphere.",1703.00739v1
+2017-03-22,Verification of Gyrokinetic codes: theoretical background and applications,"In fusion plasmas the strong magnetic field allows the fast gyro-motion to be
+systematically removed from the description of the dynamics, resulting in a
+considerable model simplification and gain of computational time. Nowadays, the
+gyrokinetic (GK) codes play a major role in the understanding of the
+development and the saturation of turbulence and in the prediction of the
+subsequent transport. Naturally, these codes require thorough verification and
+validation.
+  Here we present a new and generic theoretical framework and specific
+numerical applications to test the faithfulness of the implemented models to
+theory and to verify the domain of applicability of existing GK codes. For a
+sound verification process, the underlying theoretical GK model and the
+numerical scheme must be considered at the same time, which has rarely been
+done and therefore makes this approach pioneering. At the analytical level, the
+main novelty consists in using advanced mathematical tools such as variational
+formulation of dynamics for systematization of basic GK code's equations to
+access the limits of their applicability. The verification of numerical scheme
+is proposed via the benchmark effort.
+  In this work, specific examples of code verification are presented for two GK
+codes: the multi-species electromagnetic ORB5 (PIC) and the radially global
+version of GENE (Eulerian). The proposed methodology can be applied to any
+existing GK code. We establish a hierarchy of reduced GK Vlasov-Maxwell
+equations implemented in the ORB5 and GENE codes using the Lagrangian
+variational formulation. At the computational level, detailed verifications of
+global electromagnetic test cases developed from the CYCLONE Base Case are
+considered, including a parametric $\beta$-scan covering the transition from
+ITG to KBM and the spectral properties at the nominal $\beta$ value.",1703.07582v2
+2017-06-23,Asymptotic structure of $\mathcal{N}=2$ supergravity in 3D: extended super-BMS$_3$ and nonlinear energy bounds,"The asymptotically flat structure of $\mathcal{N}=(2,0)$ supergravity in
+three spacetime dimensions is explored. The asymptotic symmetries are spanned
+by an extension of the super-BMS$_3$ algebra, with two independent $\hat{u}(1)$
+currents of electric and magnetic type. These currents are associated to $U(1)$
+fields being even and odd under parity, respectively. Remarkably, although the
+$U(1)$ fields do not generate a backreaction on the metric, they provide
+nontrivial Sugawara-like contributions to the BMS$_3$ generators, and hence to
+the energy and the angular momentum. The entropy of flat cosmological
+spacetimes with $U(1)$ fields then acquires a nontrivial dependence on the
+$\hat{u}(1)$ charges. If the spin structure is odd, the ground state
+corresponds to Minkowski spacetime, and although the anticommutator of the
+canonical supercharges is linear in the energy and in the electric-like
+$\hat{u}(1)$ charge, the energy becomes bounded from below by the energy of the
+ground state shifted by the square of the electric-like $\hat{u}(1)$ charge. If
+the spin structure is even, the same bound for the energy generically holds,
+unless the absolute value of the electric-like charge is less than minus the
+mass of Minkowski spacetime in vacuum, so that the energy has to be
+nonnegative. The explicit form of the Killing spinors is found for a wide class
+of configurations that fulfills our boundary conditions, and they exist
+precisely when the corresponding bounds are saturated. It is also shown that
+the spectra with periodic or antiperiodic boundary conditions for the fermionic
+fields are related by spectral flow, in a similar way as it occurs for the
+$\mathcal{N}=2$ super-Virasoro algebra. Indeed, our super-BMS$_3$ algebra can
+be recovered from the flat limit of the superconformal algebra with
+$\mathcal{N}=(2,2)$, truncating the fermionic generators of the right copy.",1706.07542v3
+2017-11-30,Anomalous and regular transport in spin 1/2 chains: AC conductivity,"We study magnetization transport in anisotropic spin-$1/2$ chains governed by
+the integrable XXZ model with and without integrability-breaking perturbations
+at high temperatures ($T\to \infty$) using a hybrid approach that combines
+exact sum-rules with judiciously chosen Ans\""atze. In the integrable XXZ model
+we find (i) super-diffusion at the isotropic (Heisenberg) point, with frequency
+dependent conductivity $ \sigma'(\omega\to 0) \sim |\omega|^{\alpha}$, where
+$\alpha=-3/7$ in close numerical agreement with recent $t$-DMRG computations;
+(ii) a continuously drifting exponent from $\alpha=-1^+$ in the XY limit of the
+model to $\alpha>0$ within the Ising regime; and (iii) a diffusion constant
+saturating in the XY coupling deep in the Ising limit. We consider two kinds of
+integrability breaking perturbations --- a simple next-nearest-neighbor
+spin-flip term ($J_2$) and a three-spin assisted variant ($t_2$), natural in
+the fermion particle representation of the spin chain. In the first case we
+discover a remarkable sensitivity of $\sigma'(\omega)$ to the sign of $J_2$,
+with enhanced low frequency spectral weight and a pronounced upward shift in
+the magnitude of $\alpha$ for $J_2>0$. Perhaps even more surprising, we find
+sub-diffusion ($\alpha>0$) over a range of $J_2<0$. By contrast, the effects of
+the \enquote{fermionic} three-spin perturbation are sign symmetric; this
+perturbation produces a clearly observable hydrodynamic relaxation. At large
+strength of the integrability breaking term $J_2\to \pm \infty$ the problem is
+effectively non-interacting (fermions hopping on odd and even sublattices) and
+we find $\alpha\to -1$ behavior reminiscent of the XY limit of the XXZ chain.
+Exact diagonalization studies largely corroborate these findings at
+mid-frequencies.",1711.11214v2
+2017-12-13,Magnetotransport in a model of a disordered strange metal,"Despite much theoretical effort, there is no complete theory of the 'strange'
+metal state of the high temperature superconductors, and its
+linear-in-temperature, $T$, resistivity. Recent experiments showing an
+unexpected linear-in-field, $B$, magnetoresistivity have deepened the puzzle.
+We propose a simple model of itinerant electrons, interacting via random
+couplings with electrons localized on a lattice of quantum 'dots' or 'islands'.
+This model is solvable in a large-$N$ limit, and can reproduce observed
+behavior. The key feature of our model is that the electrons in each quantum
+dot are described by a Sachdev-Ye-Kitaev model describing electrons without
+quasiparticle excitations. For a particular choice of the interaction between
+the itinerant and localized electrons, this model realizes a controlled
+description of a diffusive marginal-Fermi liquid (MFL) without momentum
+conservation, which has a linear-in-$T$ resistivity and a $T \ln T$ specific
+heat as $T\rightarrow 0$. By tuning the strength of this interaction relative
+to the bandwidth of the itinerant electrons, we can additionally obtain a
+finite-$T$ crossover to a fully incoherent regime that also has a linear-in-$T$
+resistivity. We show that the MFL regime has conductivities which scale as a
+function of $B/T$; however, its magnetoresistance saturates at large $B$. We
+then consider a macroscopically disordered sample with domains of MFLs with
+varying densities of electrons. Using an effective-medium approximation, we
+obtain a macroscopic electrical resistance that scales linearly in the magnetic
+field $B$ applied perpendicular to the plane of the sample, at large $B$. The
+resistance also scales linearly in $T$ at small $B$, and as $T f(B/T)$ at
+intermediate $B$. We consider implications for recent experiments reporting
+linear transverse magnetoresistance in the strange metal phases of the
+pnictides and cuprates.",1712.05026v3
+2017-12-19,"Convective blueshifts in the solar atmosphere, I. Absolute measurements with LARS of the spectral lines at 6302 Å","The solar convection manifests as granulation and intergranulation at the
+solar surface. In the photosphere, convective motions induce differential
+Doppler shifts to spectral lines. The observed convective blueshift varies
+across the solar disk. We focus on the impact of solar convection on the
+atmosphere and aim to resolve its velocity stratification in the photosphere.
+We performed high-resolution spectroscopic observations of the solar spectrum
+in the 6302\,\AA\ range with the Laser Absolute Reference Spectrograph (LARS)
+at the Vacuum Tower Telescope. A laser frequency comb enabled the calibration
+of the spectra to an absolute wavelength scale with an accuracy of ${\rm
+1\,m\,s^{-1}}$. We systematically scanned the Quiet Sun from disk center to the
+limb at ten selected heliocentric positions. The analysis included 99 time
+sequences of up to 20\,min in length. By means of ephemeris and reference
+corrections, we translated wavelength shifts into absolute line-of-sight
+velocities. A bisector analysis on the line profiles yielded the shapes and
+convective shifts of seven photospheric lines. At disk center, the bisector
+profiles of the iron lines feature a pronounced C-shape with maximum convective
+blueshifts of up to ${\rm -450\,m\,s^{-1}}$ in the spectral line wings. Toward
+the solar limb, the bisectors change into a \textbackslash-shape with a
+saturation in the line core at a redshift of ${\rm +100\,m\,s^{-1}}$. The
+center-to-limb variation of the line core velocities shows a slight increase in
+blueshift when departing the disk center for larger heliocentric angles. This
+increase in blueshift is more pronounced for the magnetically less active
+meridian than for the equator. Toward the solar limb, the blueshift decreases
+and can turn into a redshift. Best spectroscopic measurements enabled the
+accurate determination of absolute convective shifts in the solar photosphere.",1712.07059v1
+2018-01-04,Complex temperature dependence of coupling and dissipation of cavity-magnon polaritons from milliKelvin to room temperature,"Hybridized magnonic-photonic systems are key components for future
+information processing technologies such as storage, manipulation or conversion
+of data both in the classical (mostly at room temperature) and quantum
+(cryogenic) regime. In this work, we investigate a YIG sphere coupled strongly
+to a microwave cavity over the full temperature range from $290\,\mathrm{K}$
+down to $30\,\mathrm{mK}$. The cavity-magnon polaritons are studied from the
+classical to the quantum regime where the thermal energy is less than one
+resonant microwave quanta, i.e. at temperatures below $1\,\mathrm{K}$. We
+compare the temperature dependence of the coupling strength $g_{\rm{eff}}(T)$,
+describing the strength of coherent energy exchange between spin ensemble and
+cavity photon, to the temperature behavior of the saturation magnetization
+evolution $M_{\rm{s}}(T)$ and find strong deviations at low temperatures. The
+temperature dependence of magnonic disspation is governed at intermediate
+temperatures by rare earth impurity scattering leading to a strong peak at
+$40\,$K. The linewidth $\kappa_{\rm{m}}$ decreases to $1.2\,$MHz at $30\,$mK,
+making this system suitable as a building block for quantum electrodynamics
+experiments. We achieve an electromagnonic cooperativity in excess of $20$ over
+the entire temperature range, with values beyond $100$ in the milliKelvin
+regime as well as at room temperature. With our measurements, spectroscopy on
+strongly coupled magnon-photon systems is demonstrated as versatile tool for
+spin material studies over large temperature ranges. Key parameters are
+provided in a single measurement, thus simplifying investigations
+significantly.",1801.01439v1
+2018-03-17,Is Quintessence an Indication of a Time-Varying Gravitational Constant?,"A model is presented where the quintessence parameter, w, is related to a
+time-varying gravitational constant. Assuming a present value of w equals -.98,
+we predict a current variation of G dot/G = -.06 H0. H0 is Hubbles parameter, G
+is Newtons constant and G dot is the derivative of G with respect to time.
+Thus, G has a cosmic origin, is decreasing with respect to cosmological time,
+and is proportional to H0, as originally proposed by the Dirac-Jordan
+hypothesis. Within our model, we can explain the cosmological constant
+fine-tuning problem, the discrepancy between the present very weak value of the
+cosmological constant, and the much greater vacuum energy found in earlier
+epochs. To formalize and solidify our model, we give two distinct functions of
+G(a), the cosmic scale parameter. We treat inverse G as an order parameter,
+which vanishes at high energies; at low temperatures, it reaches a saturation
+value, a value we are close to today. Our first function for inverse G is
+motivated by a charging capacitor; the second treats inverse G by analogy to a
+magnetic response. Both functions, even though very distinct, give a remarkably
+similar tracking behavior for w(a). Interestingly, both functions indicate the
+onset of G formation at a temperature of approximately 7 *1021 degrees Kelvin,
+in contrast to the concordance model. At the temperature of formation, we find
+that G has increased to roughly 4*1020 times its present value. For most of
+cosmic evolution, however, our variable G model gives results similar to the
+predictions of the concordance model, except in the very early universe, as we
+shall demonstrate. Within our framework, the weakening of G to its current
+value G0 is speculated as the true cause for the observed unanticipated
+acceleration of the universe.",1803.06431v1
+2018-04-30,Detailed study on the Fermi surfaces of the type-II Dirac semimetallic candidates PdTe2 and PtTe2,"We present a detailed quantum oscillatory study on the Dirac type-II
+semimetallic candidates PdTe$_{2}$ and PtTe$_{2}$ \emph{via} the temperature
+and the angular dependence of the de Haas-van Alphen (dHvA) and Shubnikov-de
+Haas (SdH) effects. In high quality single crystals of both compounds, i.e.
+displaying carrier mobilities between $10^3$ and $10^4$ cm$^2$/Vs, we observed
+a large non-saturating magnetoresistivity (MR) which in PtTe$_2$ at a
+temperature $T = 1.3$ K, leads to an increase in the resistivity up to $5
+\times 10^{4}$ % under a magnetic field $\mu_0 H = 62$ T. These high mobilities
+correlate with their light effective masses in the range of 0.04 to 1 bare
+electron mass according to our measurements. For PdTe$_{2}$ the experimentally
+determined Fermi surface cross-sectional areas show an excellent agreement with
+those resulting from band-structure calculations. Surprisingly, this is not the
+case for PtTe$_{2}$ whose agreement between calculations and experiments is
+relatively poor even when electronic correlations are included in the
+calculations. Therefore, our study provides a strong support for the existence
+of a Dirac type-II node in PdTe$_2$ and probably also for PtTe$_2$. Band
+structure calculations indicate that the topologically non-trivial bands of
+PtTe$_2$ do not cross the Fermi-level ($\varepsilon_F$). In contrast, for
+PdTe$_2$ the Dirac type-II cone does intersect $\varepsilon_F$, although our
+calculations also indicate that the associated cyclotron orbit on the Fermi
+surface is located in a distinct $k_z$ plane with respect to the one of the
+Dirac type-II node. Therefore it should yield a trivial Berry-phase.",1805.00087v1
+2018-05-07,Surface superconductivity in the Weyl semimetal MoTe2 detected by point contact spectroscopy,"MoTe2 is a Weyl semimetal, which exhibits unique non-saturating
+magnetoresistance and strongly reinforced superconductivity under pressure.
+Here, we demonstrate that a novel mesoscopic superconductivity at ambient
+pressure arises on the surface of MoTe2 with a critical temperature up to 5 K
+significantly exceeding the bulk Tc=0.1K. We measured the derivatives of I-V
+curves for metallic hetero-contacts of MoTe2 with Ag or Cu, homo-contacts of
+MoTe2 as well as ""soft"" point contacts (PCs). Large number of these
+hetero-contacts exhibit a dV/dI dependence, which is characteristic for Andreev
+reflection. It allows to determine the superconducting gap \Delta. The average
+gap values are 2\Delta=1.30+/-0.15 meV with a 2\Delta/kBTc ratio of 3.7+/-0.4,
+which slightly exceeds the standard BCS value of 3.52. Furthermore, the
+temperature dependence of the gap follows a BCS-like behavior, which points to
+a nodeless superconducting order parameter with some strong-coupling
+renormalization. Remarkably, the observation of a ""gapless-like"" single minimum
+in the dV/dI of ""soft"" PCs may indicate a topological superconducting state of
+the MoTe2 surface as these contacts probe mainly the interface and avoid
+additional pressure effect. Therefore, MoTe2 might be a suitable material to
+study new forms of topological superconductivity.",1805.02470v2
+2018-07-13,Many-body localization and delocalization in large quantum chains,"We theoretically study the quench dynamics for an isolated Heisenberg spin
+chain with a random on-site magnetic field, which is one of the paradigmatic
+models of a many-body localization transition. We use the time-dependent
+variational principle as applied to matrix product states, which allows us to
+controllably study chains of a length up to $L=100$ spins, i.e., much larger
+than $L \simeq 20$ that can be treated via exact diagonalization. For the
+analysis of the data, three complementary approaches are used: (i)
+determination of the exponent $\beta$ which characterizes the power-law decay
+of the antiferromagnetic imbalance with time; (ii) similar determination of the
+exponent $\beta_\Lambda$ which characterizes the decay of a Schmidt gap in the
+entanglement spectrum, (iii) machine learning with the use, as an input, of the
+time dependence of the spin densities in the whole chain. We find that the
+consideration of the larger system sizes substantially increases the estimate
+for the critical disorder $W_c$ that separates the ergodic and many-body
+localized regimes, compared to the values of $W_c$ in the literature. On the
+ergodic side of the transition, there is a broad interval of the strength of
+disorder with slow subdiffusive transport. In this regime, the exponents
+$\beta$ and $\beta_\Lambda$ increase, with increasing $L$, for relatively small
+$L$ but saturate for $L \simeq 50$, indicating that these slow power laws
+survive in the thermodynamic limit. From a technical perspective, we develop an
+adaptation of the ""learning by confusion"" machine learning approach that can
+determine $W_c$.",1807.05051v4
+2018-09-24,Site-specific spin crossover in Fe$_{2}$TiO$_{4}$ post-spinel under high pressures to near a megabar,"X-ray diffraction studies to ~90 GPa at room temperature show that
+Fe$_{2}$TiO$_{4}$ ferrous inverse spinel undergoes the following sequence of
+structural transitions : cubic (Fd3m) to tetragonal (I41/amd)to
+orthorhombic(Cmcm) to orthorhombic(Pmma),at the indicated onset transition
+pressures. Within the Cmcm phase, site-specific spin crossover is initiated and
+involves only highly distorted octahedral sites constituting ~25% of all Fe
+locations. This is manifest as a steeper volume decrease of dV/V0 ~ 3.5% beyond
+~40 GPa and an emergent diamagnetic component discerned in 57Fe M\""ossbauer
+spectroscopy at variable cryogenic temperatures. A subsequent Cmcm to Pmma
+Fe/Ti disorder-order reconfiguration is facilitated at 6-fold coordinated
+(octahedral) sites. The rest of the high-spin Fe in 6-fold and 8-fold
+coordinated sites (~75% abundance) in the Pmma phase exhibit average saturation
+internal magnetic fields of H$_{hf}$ ~ 42 T to ~90 GPa, typical of spin-only
+(orbitally quenched) Fermi-contact values. By contrast average H$_{hf}$ ~ 20 T
+values, signifying unquenched orbital moments, occur below the 40-45 GPa
+spin-crossover initiation regime in the Cmcm phase. Therefore site-specific
+spin crossover invokes a cooperative lattice response and polyhedral
+distortions at the rest of the high-spin Fe sites, translating to 3d level
+(sub-band) changes and consequential orbital moment quenching. Near ~90 GPa
+Fe$_{2}$TiO$_{4}$ is a partially spin-converted chemically ordered Pmma
+post-spinel structure having a persistent charge gap of ~100 meV. Despite
+structural symmetry changes, partial spin crossover and lattice compressibility
+resulting in a ~33% total reduction in unit-cell volume and corresponding 3d
+bandwidth broadening, strong electron correlations persist at high
+densification.",1809.09056v1
+2019-01-16,Strong suppression of near-field radiative heat transfer by superconductivity in NbN,"Near-field (NF) radiative heat transfer (RHT) over vacuum space between
+closely spaced bodies can exceed the Planck far-field (FF) values by orders of
+magnitude. Strong effect of superconductivity on NF RHT between plane-parallel
+thin-film surfaces of niobium (Nb) was recently discovered and discussed in a
+short paper [Kr\'al\'ik et al., Phys. Rev. B 95, 060503 (2017)]. We present
+here an extensive set of experimental results on NF as well as FF RHT for
+geometrically identical samples made of niobium nitride (NbN), including a
+detailed discussion of the experimental setup and errors. The results with NbN
+show more precise agreement with theory than the original experiments with Nb.
+We observed a steep decrease of the heat flux at the transition to
+superconductivity when the colder sample (absorber) passed from normal to
+superconducting (SC) state ($T_c \approx 15.2$ K), corresponding to up to an
+8-fold contrast between the normal and SC states. This differs dramatically
+from the situation in the FF regime, where only a weak effect of
+superconductivity was observed. Surprisingly, the contrast remains sizeable
+even at high temperatures of the hot sample (radiator) with the characteristic
+energy of radiation far above the SC energy gap. We explain the maximum of
+contrast in heat flux between the normal and SC states, found at a distance
+about ten times shorter than the crossover distance between NF and FF heat
+flux, being $d \approx 1000/T$ [${\mu}$m]. We analyze in detail the roles of
+transversal electric (TE) and magnetic (TM) modes in the steep decrease of heat
+flux below the SC critical temperature and the subsequent flux saturation at
+low temperatures. Interestingly, we expose experimentally for the first time
+the effect of destructive interference of FF thermal radiation in the vacuum
+gap, which was observable at temperatures below the absorber superconducting
+transition.",1901.05538v2
+2019-04-12,Quasilinear approach of the cumulative whistler instability in fast solar winds: Constraints of electron temperature anisotropy,"Context. Solar outflows are a considerable source of free energy which
+accumulates in multiple forms like beaming (or drifting) components and/or
+temperature anisotropies. However, kinetic anisotropies of plasma particles do
+not grow indefinitely and particle-particle collisions are not efficient enough
+to explain the observed limits of these anisotropies. Instead, the
+self-generated wave instabilities can efficiently act to constrain kinetic
+anisotropies, but the existing approaches are simplified and do not provide
+satisfactory explanations. Thus, small deviations from isotropy shown by the
+electron temperature ($T$) in fast solar winds are not explained yet.
+  Aims. This paper provides an advanced quasilinear description of the whistler
+instability driven by the anisotropic electrons in conditions typical for the
+fast solar winds. The enhanced whistler-like fluctuations may constrain the
+upper limits of temperature anisotropy $A \equiv T_\perp /T_\parallel > 1$,
+where $\perp, \parallel$ are defined with respect to the magnetic field
+direction.
+  Methods. Studied are the self-generated whistler instabilities, cumulatively
+driven by the temperature anisotropy and the relative (counter)drift of the
+electron populations, e.g., core and halo electrons. Recent studies have shown
+that quasi-stable states are not bounded by the linear instability thresholds
+but an extended quasilinear approach is necessary to describe them in this
+case.
+  Results. Marginal conditions of stability are obtained from a quasilinear
+theory of the cumulative whistler instability, and approach the quasi-stable
+states of electron populations reported by the observations.The instability
+saturation is determined by the relaxation of both the temperature anisotropy
+and the relative drift of electron populations.",1904.06202v2
+2019-06-13,Activity and rotation of the X-ray emitting Kepler stars,"The relation between magnetic activity and rotation in late-type stars
+provides fundamental information on stellar dynamos and angular momentum
+evolution. Rotation/activity studies found in the literature suffer from
+inhomogeneity in the measure of activity indexes and rotation periods. We
+overcome this limitation with a study of the X-ray emitting late-type
+main-sequence stars observed by XMM-Newton and Kepler. We measure rotation
+periods from photometric variability in Kepler light curves. As activity
+indicators, we adopt the X-ray luminosity, the number frequency of white-light
+flares, the amplitude of the rotational photometric modulation, and the
+standard deviation in the Kepler light curves. The search for X-ray flares in
+the light curves provided by the EXTraS (Exploring the X-ray Transient and
+variable Sky) FP-7 project allows us to identify simultaneous X-ray and
+white-light flares. A careful selection of the X-ray sources in the Kepler
+field yields 102 main-sequence stars with spectral types from A to M. We find
+rotation periods for 74 X-ray emitting main-sequence stars, 22 of which without
+period reported in the previous literature. In the X-ray activity/rotation
+relation, we see evidence for the traditional distinction of a saturated and a
+correlated part, the latter presenting a continuous decrease in activity
+towards slower rotators. For the optical activity indicators the transition is
+abrupt and located at a period of ~ 10 d but it can be probed only marginally
+with this sample which is biased towards fast rotators due to the X-ray
+selection. We observe 7 bona-fide X-ray flares with evidence for a white-light
+counterpart in simultaneous Kepler data. We derive an X-ray flare frequency of
+~ 0.15 d^{-1} , consistent with the optical flare frequency obtained from the
+much longer Kepler time-series.",1906.05587v2
+2019-08-19,Erosion of an exoplanetary atmosphere caused by stellar winds,"We present a formalism for a first-order estimation of the magnetosphere
+radius of exoplanets orbiting stars in the range from 0.08 to 1.3 Mo. With this
+radius, we estimate the atmospheric surface that is not protected from stellar
+winds. We have analyzed this unprotected surface for the most extreme
+environment for exoplanets: GKM-type and very low-mass stars at the two limits
+of the habitable zone. The estimated unprotected surface makes it possible to
+define a likelihood for an exoplanet to retain its atmosphere. This function
+can be incorporated into the new habitability index SEPHI. Using different
+formulations in the literature in addition to stellar and exoplanet physical
+characteristics, we estimated the stellar magnetic induction, the main
+characteristics of the stellar wind, and the different star-planet interaction
+regions (sub- and super-Alfv\'enic, sub- and supersonic). With this
+information, we can estimate the radius of the exoplanet magnetopause and thus
+the exoplanet unprotected surface. We have conducted a study of the auroral
+aperture angles for Earth-like exoplanets orbiting the habitable zone of its
+star, and found different behaviors depending on whether the star is in
+rotational saturated or unsaturated regimes, with angles of aperture of the
+auroral ring above or below 36^\circ, respectively, and with different slopes
+for the linear relation between the auroral aperture angle at the inner edge of
+the habitable zone versus the difference between auroral aperture angles at the
+two boundaries of the habitable zone. When the planet is tidally locked, the
+unprotected angle increases dramatically to values higher than 40^\circ with a
+low likelihood of keeping its atmosphere. When the impact of stellar wind is
+produced in the sub-Alfv\'enic regime, the likelihood of keeping the atmosphere
+is almost zero for exoplanets orbiting very close to their star.",1908.06695v1
+2019-09-06,"Flux Free Single Crystal Growth and Detailed Physical Property Characterization of Bi1-xSbx (x = 0.05, 0.1 and 0.15) Topological Insulator","Here, we report the crystal growth, physical and transport properties of
+Bi1-xSbx (x = 0.05, 0.1 and 0.15) topological insulator. Single crystals of
+Bi1-xSbx (x = 0.05, 0.1 and 0.15) were grown by melting bismuth and antimony
+together using the facile self flux method. The XRD measurements displayed
+highly indexed 00l lines and confirmed the crystalline nature as well as the
+rhombohedral structure of the Bi1-xSbx (x = 0.05, 0.1 and 0.15) crystals. Raman
+spectroscopy measurements for Bi1-xSbx system revealed four peaks within the
+spectral range of 10 to 250 cm-1 namely A1g and Eg modes corresponding to Bi-Bi
+and Sb-Sb vibrations. Scanning electron microscopy (SEM) and energy dispersive
+Temperature dependent electrical resistivity curves with and without applied
+magnetic field exhibited a metallic behaviour and linear non-saturating
+magneto-resistance (MR) respectively for all the antimony (Sb) concentrations
+of x = 0.05, 0.1 and 0.15. The lowest Sb concentration sample with x = 0.05
+(Bi0.95Sb0.05) exhibited the highest MR value of about 1400%, followed by x =
+0.1 and 0.15 samples (Bi0.9Sb0.1 and Bi0.85Sb0.05) with MR values reaching up
+to 500% and 110% respectively at 2K and 6Tesla applied field. The
+magneto-conductivity (MC) is fitted to the HLN (Hikami Larkin Nagaoka) equation
+and it is found that the charge conduction mechanism is mainly dominated by WAL
+(weak anti-localization) along with a small contribution from WL (weak
+localization) effect. Summarily, the short letter discusses the synthesis,
+interesting transport and magneto-transport properties of Bi1-xSbx (x = 0.05,
+0.1 and 0.15), which could be useful in understanding the fascinating
+properties of topological insulators and their technological applications.",1909.02711v1
+2019-10-15,The Fast Radio Burst Luminosity Function and Death Line in the Low-Twist Magnetar Model,"We explore the burst energy distribution of fast radio bursts (FRBs) in the
+low-twist magnetar model of Wadiasingh and Timokhin (2019). Motivated by the
+power-law fluence distributions of FRB 121102, we propose an elementary model
+for the FRB luminosity function of individual repeaters with an inversion
+protocol which directly relates the power-law distribution index of magnetar
+short burst fluences to that for FRBs. The protocol indicates the FRB energy
+scales virtually linearly with crust/field dislocation amplitude, if magnetar
+short bursts prevail in the magnetoelastic regime. Charge starvation in the
+magnetosphere during bursts (required in WT19) for individual repeaters implies
+the predicted burst fluence distribution is narrow, $\lesssim 3$ decades for
+yielding strains and oscillation frequencies feasible in magnetar crusts.
+Requiring magnetic confinement and charge starvation, we obtain a death line
+for FRBs which segregates magnetars from the normal pulsar population,
+suggesting only the former will host recurrent FRBs. We convolve the burst
+energy distribution for individual magnetars to define the distribution of
+luminosities in evolved magnetar populations. The broken power-law luminosity
+function's low energy character depends on the population model, while the high
+energy index traces that of individual repeaters. Independent of the evolved
+population, the broken power-law isotropic-equivalent energy/luminosity
+function peaks at $\sim10^{37}-10^{40}$ erg with a low-energy cutoff at $\sim
+10^{37}$ erg. Lastly, we consider the local fluence distribution of FRBs, and
+find that it can constrain the subset of FRB-producing magnetar progenitors.
+Our model suggests that improvements in sensitivity may reveal flattening of
+the global FRB fluence distribution and saturation in FRB rates.",1910.06979v2
+2019-11-04,On the Jet Production Efficiency in a Sample of the Youngest Radio Galaxies,"Here we discuss the jet production efficiency in a sample of 17 young radio
+galaxies with measured redshifts, kinematic ages, and nuclear X-ray fluxes, for
+which the observed luminosities of compact jets/lobes and accretion disks
+correspond to the same episode of the AGN activity. For the targets, we analyze
+the available optical data, estimating the bolometric luminosities of the
+accretion disks $L_{\rm bol}$, and the black hole masses; we also derive the
+minimum jet kinetic luminosities, $P_{\rm j}$. With such, we investigate the
+distribution of our sample in the three-dimensional space of the accretion rate
+$\lambda_{\rm Edd} \equiv L_{\rm bol}/L_{\rm Edd}$, the nuclear X-ray
+luminosity $L_{\rm X}$ considered here as a limit for the emission of the disk
+coronae, and $P_{\rm j}$, expressing the latter two parameters either in the
+Eddington units, or in the units of the disk luminosity. We find that (i) the
+accretion rate $\lambda_{\rm Edd}$ in our sample is distributed within a narrow
+range $\lambda_{\rm Edd} \sim 0.01 - 0.2$; (ii) the normalized jet power
+$P_{\rm j}/L_{\rm Edd}$ formally correlates with the accretion rate
+$\lambda_{\rm Edd}$, with some saturation at the largest values $\lambda_{\rm
+Edd}> 0.05$; (iii) the jet production efficiency $\eta_{\rm jet} \equiv P_{\rm
+j}/\dot{M}_{\rm acc} c^2$ spans a range from $\eta_{\rm jet} \lesssim 10^{-3}$
+up to $\sim 0.2$ at maximum, which is below the level expected for magnetically
+arrested disks around maximally spinning black holes; and (iv) there is a
+diversification in $\eta_{\rm jet}$ on the hardness--intensity diagram $L_{\rm
+X}/L_{\rm bol} - \lambda_{\rm Edd}$, with the jets being produced most
+efficiently during the high/hard states, and suppressed during the soft states.",1911.01197v2
+2020-04-17,Explicit Structure-Preserving Geometric Particle-in-Cell Algorithm in Curvilinear Orthogonal Coordinate Systems and Its Applications to Whole-Device 6D Kinetic Simulations of Tokamak Physics,"Explicit structure-preserving geometric Particle-in-Cell (PIC) algorithm in
+curvilinear orthogonal coordinate systems is developed. The work reported
+represents a further development of the structure-preserving geometric PIC
+algorithm [1-12], achieving the goal of practical applications in magnetic
+fusion research. The algorithm is constructed by discretizing the field theory
+for the system of charged particles and electromagnetic field using Whitney
+forms, discrete exterior calculus, and explicit non-canonical symplectic
+integration. In addition to the truncated infinitely dimensional symplectic
+structure, the algorithm preserves exactly many important physical symmetries
+and conservation laws, such as local energy conservation, gauge symmetry and
+the corresponding local charge conservation. As a result, the algorithm
+possesses the long-term accuracy and fidelity required for
+first-principles-based simulations of the multiscale tokamak physics. The
+algorithm has been implemented in the SymPIC code, which is designed for
+high-efficiency massively-parallel PIC simulations in modern clusters. The code
+has been applied to carry out whole-device 6D kinetic simulation studies of
+tokamak physics. A self-consistent kinetic steady state for fusion plasma in
+the tokamak geometry is numerically found with a predominately diagonal and
+anisotropic pressure tensor. The state also admits a steady-state sub-sonic ion
+flow in the range of 10 km/s, agreeing with experimental observations [13, 14]
+and analytical calculations [15, 16]. Kinetic ballooning instability in the
+self-consistent kinetic steady state is simulated. It shows that high-n
+ballooning modes have larger growth rates than low-n global modes, and in the
+nonlinear phase the modes saturate approximately in 5 ion transit times ...",2004.08150v4
+2020-05-25,Gas and dust dynamics in starlight-heated protoplanetary disks,"Theoretical models of the ionization state in protoplanetary disks suggest
+the existence of large areas with low ionization and weak coupling between the
+gas and magnetic fields. In this regime hydrodynamical instabilities may become
+important. In this work we investigate the gas and dust structure and dynamics
+for a typical T Tauri system under the influence of the vertical shear
+instability (VSI). We use global 3D radiation hydrodynamics simulations
+covering all $360^\circ$ of azimuth with embedded particles of 0.1 and 1mm
+size, evolved for 400 orbits. Stellar irradiation heating is included with
+opacities for 0.1- to 10-$\mu$m-sized dust. Saturated VSI turbulence produces a
+stress-to-pressure ratio of $\alpha \simeq 10^{-4}$. The value of $\alpha$ is
+lowest within 30~au of the star, where thermal relaxation is slower relative to
+the orbital period and approaches the rate below which VSI is cut off. The rise
+in $\alpha$ from 20 to 30~au causes a dip in the surface density near 35~au,
+leading to Rossby wave instability and the generation of a stationary,
+long-lived vortex spanning about 4~au in radius and 40~au in azimuth. Our
+results confirm previous findings that mm size grains are strongly vertically
+mixed by the VSI. The scale height aspect ratio for 1mm grains is determined to
+be 0.037, much higher than the value $H/r=0.007$ obtained from millimeter-wave
+observations of the HL~Tau system. The measured aspect ratio is better fit by
+non-ideal MHD models. In our VSI turbulence model, the mm grains drift radially
+inwards and many are trapped and concentrated inside the vortex. The turbulence
+induces a velocity dispersion of $\sim 12$~m/s for the mm grains, indicating
+that grain-grain collisions could lead to fragmentation.",2005.11974v1
+2020-06-01,Fluctuations of topological charge and chiral density in the early stage of high energy nuclear collisions,"We study systematically the topological charge density and the chiral density
+correlations in the early stage of high energy nuclear collisions: the intial
+condition is given by the McLerran-Venugopalan model and the evolution of the
+gluon fields is studied via the Classical Yang-Mills equations up to proper
+time $\tau\approx 1$ fm/c for an $SU(2)$ evolving Glasma. Topological charge is
+related to the gauge invariant $\bm E \cdot \bm B$ where $\bm E$ and $\bm B$
+denote the color-electric and color-magnetic fields, while the chiral density
+is produced via the chiral anomaly of Quantum Chromodynamics. We study how the
+correlation lengths are related to the collision energy, and how the correlated
+domains grow up with proper time in the transverse plane for a boost invariant
+longitudinal expansion. We estimate the correlation lengths of both quantities,
+that after a short transient results of the order of the typical energy scale
+of the model, namely the inverse of the saturation scale. We estimate the
+proper time for the formation of a steady state in which the production of the
+chiral density in the transverse plane per unit rapidity slows down, as well as
+the amount of chiral density that would be present at the switch time between
+the Classical Yang-Mills evolution and the relativistic transport or hydro for
+the quark-gluon plasma phase.",2006.01090v3
+2020-08-26,Spectroscopic Monitoring of Blazar S5 0716+714: Brightness-Dependent Spectral Behavior,"In this paper, we report the new results of spectroscopic observations of
+$\gamma$-ray blazar S5 0716+714 from 2019 September to 2020 March with the 2.4
+m optical telescope at Lijiang Observatory of Yunnan Observatories. The median
+cadence of observations is $\sim$ 1 day. During the second observation period
+(Epoch2), the observational data reveal an extremely bright state and a
+bluer-when-brighter (BWB) chromatism. The BWB trend of Epoch2 differs
+significantly from that of the first observation period (Epoch1). A
+significantly brightness-dependent BWB chromatism emerges in the total data of
+Epoch1 and Epoch2. The BWB trend becomes weaker towards the brighter states,
+and likely becomes saturated at the highest state. Based on a log-parabolic
+function, a power-law of synchrotron peak flux and frequency $\nu_{\rm{p}}$,
+and a power-law of the curvature of synchrotron spectrum and its
+$\nu_{\rm{p}}$, simulation well reproduces the brightness-dependent BWB trend
+of S5 0716+714. The BWB trend is seemingly controlled by the shift of
+$\nu_{\rm{p}}$ with respect to the observational window, and effectively may be
+dominated by the variations of electron average energy and magnetic field in
+emitting region.",2008.11341v1
+2020-10-12,"Flares in Open Clusters with K2. II. Pleiades, Hyades, Praesepe, Ruprecht 147, and M67","Flares, energetic eruptions on the surfaces of stars, are an unmistakable
+manifestation of magnetically driven emission. Their occurrence rates and
+energy distributions trace stellar characteristics such as mass and age. But
+before flares can be used to constrain stellar properties, the flaring-age-mass
+relation requires proper calibration. This work sets out to quantify flaring
+activity of independently age-dated main sequence stars for a broad range of
+spectral types using optical light curves obtained by the Kepler satellite.
+Drawing from the complete K2 archive, we searched 3435 $\sim 80$ day long light
+curves of 2111 open cluster members for flares using the open-source software
+packages K2SC to remove instrumental and astrophysical variability from K2
+light curves, and AltaiPony to search and characterize the flare candidates. We
+confirmed a total of 3844 flares on high probability open cluster members with
+ages from zero age main sequence (Pleiades) to 3.6 Gyr (M67). We extended the
+mass range probed in the first study of this series to span from Sun-like stars
+to mid-M dwarfs. We added the Hyades (690 Myr) to the sample as a comparison
+cluster to Praesepe (750 Myr), the 2.6 Gyr old Ruprecht 147, and several
+hundred light curves from the late K2 Campaigns in the remaining clusters. The
+flare energy distribution was similar in the entire parameter space, following
+a power law relation with exponent $\alpha\approx 1.84-2.39$. The flaring rates
+declined with age, and declined faster for higher mass stars. We found evidence
+that a rapid decline in flaring activity occurred in M1-M2 dwarfs around
+Hyades/Praesepe age, when these stars spun down to rotation periods of about 10
+days, while higher mass stars had already transitioned to lower flaring rates,
+and lower mass stars still resided in the saturated activity regime. (abridged)",2010.05576v1
+2020-11-17,Properties of polarized synchrotron emission from fluctuation-dynamo action -- I. Application to galaxy clusters,"Using magnetohydrodynamic simulations of fluctuation dynamos, we perform
+broad-bandwidth synthetic observations to investigate the properties of
+polarized synchrotron emission and the role that Faraday rotation plays in
+inferring the polarized structures in the intracluster medium (ICM) of galaxy
+clusters. In the saturated state of the dynamo, we find a Faraday depth (FD)
+dispersion $\sigma_{\rm FD} \approx 100$ rad m$^{-2}$, in agreement with
+observed values in the ICM. Remarkably, the FD power spectrum is qualitatively
+similar to $M(k)/k$, where $M(k)$ is the magnetic spectrum and $k$ the
+wavenumber. However, this similarity is broken at high $k$ when FD is obtained
+by applying RM synthesis to polarized emission from the ICM due to poor
+resolution and complexities of spectrum in FD space. Unlike the Gaussian
+probability distribution function (PDF) obtained for FD, the PDF of the
+synchrotron intensity is lognormal. A relatively large $\sigma_{\rm FD}$ in the
+ICM gives rise to strong frequency-dependent variations of the pixel-wise mean
+and peak polarized intensities at low frequencies ($\lesssim 1.5\,{\rm GHz}$).
+The mean fractional polarization $\langle p \rangle$ obtained at the resolution
+of the simulations increases from $<0.1$ at 0.5 GHz to its intrinsic value of
+$\sim0.3$ at 6 GHz. Beam smoothing significantly affects the polarization
+properties below $\lesssim 1.5\,{\rm GHz}$, reducing $\langle p \rangle$ to
+$\lesssim 0.01$ at 0.5 GHz. At frequencies $\gtrsim 5\,{\rm GHz}$, polarization
+remains largely unaffected, even when recovered using RM synthesis. Thus, our
+results underline the need for high-frequency ($\gtrsim 5\,{\rm GHz}$)
+observations with future radio telescopes to effectively probe the properties
+of polarized emission in the ICM.",2011.08499v2
+2021-01-13,Rapid Spectral Variability of a Giant Flare from a Magnetar in NGC 253,"Magnetars are slowly-rotating neutron stars with extremely strong magnetic
+fields ($10^{13-15}$ G), episodically emitting $\sim100$ ms long X-ray bursts
+with energies of $\sim10^{40-41}$ erg. Rarely, they produce extremely bright,
+energetic giant flares that begin with a short ($\sim0.2$ s), intense flash,
+followed by fainter, longer lasting emission modulated by the magnetar spin
+period (typically 2-12 s), thus confirming their origin. Over the last 40
+years, only three such flares have been observed in our local group; they all
+suffered from instrumental saturation due to their extreme intensity. It has
+been proposed that extra-galactic giant flares likely constitute a subset of
+short gamma-ray bursts, noting that the sensitivity of current instrumentation
+prevents us from detecting the pulsating tail, while the initial bright flash
+is readily observable out to distances $\sim 10-20$ Mpc. Here, we report X- and
+gamma-ray observations of GRB 200415A, which exhibits a rapid onset, very fast
+time variability, flat spectra and significant sub-millisecond spectral
+evolution. These attributes match well with those expected for a giant flare
+from an extra-galactic magnetar, noting that GRB 200415A is directionally
+associated with the galaxy NGC 253 ($\sim$3.5 Mpc away). The detection of
+$\sim3$ MeV photons provides definitive evidence for relativistic motion of the
+emitting plasma. The observed rapid spectral evolution can naturally be
+generated by radiation emanating from such rapidly-moving gas in a rotating
+magnetar.",2101.05146v1
+2021-03-23,Exact one- and two-site reduced dynamics in a finite-size quantum Ising ring after a quench: A semi-analytical approach,"We study the non-equilibrium dynamics of a homogeneous quantum Ising ring
+after a quench, in which the transverse field $g$ suddenly changes from zero to
+a nonzero value. The long-timescale reduced dynamics of a single spin and of
+two nearest-neighbor spins, which involves the evaluation of expectation values
+of odd operators that break the fermion parity, is exactly obtained for
+finite-size but large rings through the use of a recently developed Pfaffian
+method [N. Wu, Phys. Rev. E 101, 042108 (2020)]. Time dependence of the
+transverse and longitudinal magnetizations, single-spin purity, expectation
+value of the string operator $X_j=\prod^{j-1}_{l=1}\sigma^z_l\sigma^x_j$,
+several equal-time two-site correlators, and pairwise concurrence after
+quenches to different phases are numerically studied. Our main findings are
+that (i) The expectation value of a generic odd operator approaches zero in the
+long-time limit; (ii) $\langle X_j\rangle_t$ exhibits $j$-independent
+exponential decay for a quench to $g=1$ and the time at which $\langle
+X_j\rangle_t$ reaches its first maximum scales linearly with $j$; (iii) The
+single-spin purity dynamics is mainly controlled by
+$\langle\sigma^x_j\rangle_t$ ($\langle\sigma^z_j\rangle_t$) for a quench to
+$g<1$ ($g\geq 1$). For quenches to the disordered phase with $g\gg1$, the
+single-spin tends to be in the maximally mixed state and the transverse and
+longitudinal correlators $\langle\sigma^z_j\sigma^z_{j+1}\rangle_t$ and
+$\langle\sigma^x_j\sigma^x_{j+1}\rangle_t$ respectively approaches $-0.25$ and
+$0.5$ in the thermodynamic limit; (iv) The nearest-neighbor entanglement
+acquires a finite plateau value that increases with increasing $g$, and
+approaches a saturated value $\sim0.125$ for $g\gg1$.",2103.12509v2
+2021-05-26,Mott-Anderson Metal-Insulator Transitions from Entanglement,"A metal can be driven to an insulating phase through distinct mechanisms. A
+possible way is via the Coulomb interaction, which then defines the Mott
+metal-insulator transition (MIT). Another possibility is the MIT driven by
+disorder, the so-called Anderson MIT. Here we analyze interacting particles in
+disordered Hubbard chains $-$ thus comprising the Mott-Anderson physics $-$ by
+investigating the ground-state entanglement with density functional theory. The
+localization signature on entanglement is found to be a local minimum at a
+certain critical density. Individually, the Mott (Anderson) MIT has a single
+critical density whose minimum entanglement decreases as the interaction
+(disorder) enhances. While in the Mott MIT entanglement saturates at finite
+values, characterizing partial localization, in the Anderson MIT the system
+reaches full localization, with zero entanglement, for sufficiently strong
+disorder. In the combined Mott-Anderson MIT, we find three critical densities
+referring to local minima on entanglement. One of them is the same as for the
+Anderson MIT, but now the presence of interaction requires a stronger disorder
+potential to induce localization. A second critical density is related to the
+Mott MIT, but due to disorder it is displaced by a factor proportional to the
+concentration of impurities. The third local minimum on entanglement is unique
+to the concomitant presence of disorder and interaction, found to be related to
+an effective density phenomenon, thus referred to as a Mott-like MIT. Since
+entanglement has been intrinsically connected to the magnetic susceptibility
+$-$ a quantity promptly available in cold atoms experiments $-$ our detailed
+numerical description might be useful for the experimental investigation of
+Mott-Anderson MIT.",2105.12529v2
+2021-06-28,The eROSITA Final Equatorial-Depth Survey (eFEDS). The stellar counterparts of eROSITA sources identified by machine learning and Bayesian algorithms,"Stars are ubiquitous X-ray emitters and will be a substantial fraction of the
+X-ray sources detected in the on-going all-sky survey performed by the eROSITA
+instrument aboard the Spectrum Roentgen Gamma (SRG) observatory. We use the
+X-ray sources in the eROSITA Final Equatorial-Depth Survey (eFEDS) field
+observed during the SRG performance verification phase to investigate different
+strategies to identify the stars among other source categories. We focus here
+on Support Vector Machine (SVM) and Bayesian approaches, and our approaches are
+based on a cross-match with the Gaia catalog, which will eventually contain
+counterparts to virtually all stellar eROSITA sources. We estimate that 2060
+stars are among the eFEDS sources based on the geometric match distance
+distribution, and we identify the 2060 most likely stellar sources with the SVM
+and Bayesian methods, the latter being named HamStars in the eROSITA context.
+Both methods reach completeness and reliability percentages of almost 90%, and
+the agreement between both methods is, incidentally, also about 90%. Knowing
+the true number of stellar sources allowed us to derive association
+probabilities $p_{ij}$ for the SVM method similar to the Bayesian method so
+that one can construct samples with defined completeness and reliability
+properties using appropriate cuts in $p_{ij}$. The thus identified stellar
+sources show the typical characteristics known for magnetically active stars,
+specifically, they are generally compatible with the saturation level, show a
+large spread in activity for stars of spectral F to G, and have comparatively
+high fractional X-ray luminosities for later spectral types.",2106.14521v1
+2021-07-05,"Surface rotation and photometric activity for Kepler targets. II. G and F main-sequence stars, and cool subgiant stars","Dark magnetic spots crossing the stellar disc lead to quasi-periodic
+brightness variations, which allow us to constrain stellar surface rotation and
+photometric activity. The current work is the second of this series (Santos et
+al. 2019; Paper I), where we analyze the Kepler long-cadence data of 132,921
+main-sequence F and G stars and late subgiant stars. Rotation-period candidates
+are obtained by combining wavelet analysis with autocorrelation function.
+Reliable rotation periods are then selected via a machine learning (ML)
+algorithm (Breton et al. 2021), automatic selection, and complementary visual
+inspection. The ML training data set comprises 26,521 main-sequence K and M
+stars from Paper I. To supplement the training, we analyze in the same way as
+Paper I, i.e. automatic selection and visual inspection, 34,100 additional
+stars. We finally provide rotation periods Prot and associated photometric
+activity proxy Sph for 39,592 targets. Hotter stars are generally faster
+rotators than cooler stars. For main-sequence G stars, Sph spans a wider range
+of values with increasing effective temperature, while F stars tend to have
+smaller Sph values in comparison with cooler stars. Overall for G stars, fast
+rotators are photometrically more active than slow rotators, with Sph
+saturating at short periods. The combined outcome of the two papers accounts
+for average Prot and Sph values for 55,232 main-sequence and subgiant FGKM
+stars (out of 159,442 targets), with 24,182 new Prot detections in comparison
+with McQuillan et al. (2014). The upper edge of the Prot distribution is
+located at longer Prot than found previously.",2107.02217v2
+2021-07-01,Cooling flows around cold clouds in the circumgalactic medium: steady-state models & comparison with TNG50,"Cold, non-self-gravitating clumps occur in various astrophysical systems,
+ranging from the interstellar and circumgalactic medium (CGM), to AGN outflows
+and solar coronal loops. Cold gas has diverse origins such as turbulent mixing
+or precipitation from hotter phases. We obtain the analytic solution for a
+steady pressure-driven 1-D cooling flow around cold, local over-densities,
+irrespective of their origin. Our solutions describe the slow and steady
+radiative cooling-driven gas inflow in the saturated regime of nonlinear
+thermal instability in clouds, sheets and filaments. Such a cooling flow
+develops when the gas around small clumps undergoes radiative cooling. These
+small-scale, cold `seeds' are embedded in a large volume-filling hot CGM
+maintained by feedback. We use a simple two-fluid treatment to include magnetic
+fields as an additional polytropic fluid. To test the limits of applicability
+of these analytic solutions, we compare with the gas structure found in and
+around small-scale cold clouds in the CGM of massive halos in the TNG50
+cosmological MHD simulation from the IllustrisTNG suite. Despite qualitative
+resemblance of the gas structure, we find deviations from steady state profiles
+generated by our model. Complex geometries and turbulence all add complexity
+beyond our analytic solutions. We derive an exact relation between the mass
+cooling rate ($\dot{\rm M}_{\rm cool}$) and the radiative cooling rate
+($\dot{\rm E}_{\rm cool}$) for a steady cooling flow. A comparison with the
+TNG50 clouds shows that this cooling flow relation only applies in a narrow
+temperature range around $\rm \sim 10^{4.5}$ K where the isobaric cooling time
+is the shortest. In general, turbulence and mixing, instead of radiative
+cooling, may dominate the transition of gas between different temperature
+phases.",2107.02722v2
+2021-09-30,Electron Heat Flux in the Solar Wind: Generalized Approaches to Fluid Transport with a Variety of Skewed Velocity Distributions,"In the solar corona and solar wind, electron heat conduction is an important
+process that transports energy over large distances and helps determine the
+spatial variation of temperature. High-density regions undergoing rapid
+particle-particle collisions exhibit a heat flux described well by classical
+Spitzer-Harm theory. However, much of the heliosphere is closer to a more
+collisionless state, and there is no standard description of heat conduction
+for fluid-based (e.g., magnetohydrodynamic) models that applies generally. Some
+proposed models rely on electron velocity distributions that exhibit negative
+values of the phase-space density. In this paper, we explore how
+positive-definite velocity distributions can be used in fluid-based
+conservation equations for the electron heat flux along magnetic-field lines in
+the corona and solar wind. We study both analytic forms of skewed distributions
+(e.g., skew-normal distributions, two-sided bi-Maxwellians, and
+constant-collision-time electrostatic solutions) and empirical fits to
+measurements of core, halo, and strahl electrons in interplanetary space. We
+also present example solutions to a generalized conservation equation for the
+heat flux in the solar wind, with some limiting cases found to resemble known
+free-streaming approximations. The resulting values of the electron heat flux
+vary as a function of radial distance and Knudsen number in ways that resemble
+observed data. We note that this model does not include the effects of kinetic
+instabilities (which may impose saturation limits when active), so for now its
+regime of applicability is limited to collisionless heat-flux evolution away
+from the known instability boundaries in parameter space.",2109.15267v1
+2021-10-05,"Possible unconventional pairing in $(\text{Ca,Sr})_{3}(\text{Ir,Rh})_{4}\text{Sn}_{13}$ superconductors revealed by controlling disorder","We study the evolution of temperature-dependent resistivity with controlled
+point-like disorder induced by 2.5 MeV electron irradiation in stoichiometric
+compositions of the ""3-4-13"" stannides,
+$(\text{Ca,Sr})_{3}(\text{Ir,Rh})_{4}\text{Sn}_{13}$.Three of these cubic
+compounds exhibit a microscopic coexistence of charge-density wave (CDW) order
+and superconductivity (SC), while $\text{Ca}_{3}\text{Rh}_{4}\text{Sn}_{13}$
+does not develop CDW order. As expected, the CDW transition temperature,
+$T_{\text{CDW}}$, is universally suppressed by irradiation in all three
+compositions. The superconducting transition temperature, $T_{c}$, behaves in a
+more complex manner. In $\text{Sr}_{3}\text{Rh}_{4}\text{Sn}_{13}$, it
+increases initially in a way consistent with a direct competition of CDW and
+SC, but quickly saturates at higher irradiation doses. In the other three
+compounds, $T_{c}$ is monotonically suppressed by irradiation. The strongest
+suppression is found in $\text{Ca}_{3}\text{Rh}_{4}\text{Sn}_{13}$, which does
+not have CDW order. We further examine this composition by measuring the London
+penetration depth, $\lambda(T)$, from which we derive the superfluid density.
+The result unambiguously points to a weak-coupling, full single gap, isotropic
+superconducting state. Therefore, we must explain two seemingly incompatible
+experimental observations: a single isotropic superconducting gap and a
+significant suppression of $T_{c}$ by non-magnetic disorder. We conduct a
+quantitative theoretical analysis based on a generalized Anderson theorem which
+points to an unconventional multiband $s^{+-}$-pairing state where the sign of
+the order parameter is different on one (or a small subset) of the smaller
+Fermi surface sheets, but remains overall fully-gapped.",2110.02025v3
+2022-04-05,Quantum noise limited microwave amplification using a graphene Josephson junction,"Josephson junctions (JJ) and their tunable properties, including their
+nonlinearities, form the core of superconducting circuit quantum
+electrodynamics (cQED). In quantum circuits, low-noise amplification of feeble
+microwave signals is essential and the Josephson parametric amplifiers (JPA)
+are the widely used devices. The existing JPAs are based on Al-AlOx-Al tunnel
+junctions realized in a superconducting quantum interference device geometry,
+where magnetic flux is the knob for tuning the frequency. Recent experimental
+realizations of 2D van der Waals JJs provide an opportunity to implement
+various cQED devices with the added advantage of tuning the junction properties
+and the operating point using a gate potential. While other components of a
+possible 2D van der Waals cQED architecture have been demonstrated -- quantum
+noise limited amplifier, an essential component, has not been realized. Here we
+implement a quantum noise limited JPA, using a graphene JJ, that has linear
+resonance gate tunability of 3.5 GHz. We report 24 dB amplification with 10 MHz
+bandwidth and -130 dBm saturation power; performance on par with the best
+single-junction JPAs. Importantly, our gate tunable JPA works in the
+quantum-limited noise regime which makes it an attractive option for highly
+sensitive signal processing. Our work has implications for novel bolometers --
+the low heat capacity of graphene together with JJ nonlinearity can result in
+an extremely sensitive microwave bolometer embedded inside a quantum
+noise-limited amplifier. In general, our work will open up exploration of
+scalable device architecture of 2D van der Waals materials by integrating a
+sensor with the quantum amplifier.",2204.02103v1
+2022-08-06,Theoretical studies on switching of magnetisation in thin film,"In the present chapter, we focus on the switching of magnetisation, or the
+metastable lifetime of a ferromagnetic system. In this regard, particularly the
+Ising model and the Blume-Capel model, have been simulated in the presence of
+an externally applied magnetic field by the Monte-Carlo simulation technique
+based on the Metropolis algorithm. Magnetisation switching is found to be
+faster in the presence of disorder, modelled here by a quenched random field.
+The strength of the random field is observed to play a similar role to that
+played by temperature. Becker-D\""oring theory of classical nucleation
+(originally proposed for the spin-1/2 Ising system) has been verified in the
+random field Ising model. However, a stronger random field affects the
+nucleation regime. In a cubic Ising lattice, surface reversal time is found to
+be different from the bulk reversal time. That distinct behaviour of the
+surface in contrast to the bulk has been studied here by introducing a relative
+interfacial interaction strength ($R$). Depending on $R$, temperature, and
+applied field, a competitive switching of magnetisation of surface and bulk is
+noticed. The effect of anisotropy ($D$) on the metastable lifetime has been
+investigated. We report a linear dependency of the mean macroscopic reversal
+time on a suitably defined microscopic reversal time. The saturated
+magnetisation $M_f$, after the reversal, is noticed to be strongly dependent on
+$D$. $M_f$, $D$, and $h$ (field) are found to follow a proposed scaling
+relation. Finally, Becker-D\""oring theory as well as Avrami's law are verified
+in spin-$s$ Ising and Blume-Capel models. The switching time depends on the
+number of accessible spin states.",2208.03480v3
+2022-10-06,Exploring the limits of MEG spatial resolution with multipolar expansions,"The advent of scalp magnetoencephalography (MEG) based on optically pumped
+magnetometers (OPMs) may represent a step change in the field of human
+electrophysiology. Compared to cryogenic MEG based on superconducting quantum
+interference devices, scalp MEG promises significantly higher spatial
+resolution imaging but it also comes with numerous challenges regarding how to
+optimally design OPM arrays. In this context, we sought to provide a systematic
+description of MEG spatial resolution as a function of the number of sensors,
+sensor-to-brain distance, sensor type, and signal-to-noise ratio. To that aim,
+we present an analytical theory based on MEG multipolar expansions that
+enables, once supplemented with experimental input and simulations,
+quantitative assessment of the limits of MEG spatial resolution in terms of two
+qualitatively distinct regimes. In the regime of asymptotically high-density
+MEG, we provide a mathematically rigorous description of how magnetic field
+smoothness constraints spatial resolution to a slow, logarithmic divergence. In
+the opposite regime of low-density MEG, it is sensor density that constraints
+spatial resolution to a faster increase following a square-root law. The
+transition between these two regimes controls how MEG spatial resolution
+saturates as sensors approach sources of neural activity. This two-regime model
+of MEG spatial resolution integrates known observations (e.g., the difficulty
+of improving spatial resolution by increasing sensor density, the gain brought
+by moving sensors on scalp, or the usefulness of multi-component sensors) and
+gathers them under a unifying theoretical framework that highlights the
+underlying physics and reveals properties inaccessible to simulations. We
+propose that this framework may find useful applications to benchmark the
+design of future OPM-based scalp MEG systems.",2210.02863v2
+2022-10-15,Non-local magnon transconductance in extended magnetic insulating films.\\ Part I: spin diode effect,"This review provides a comprehensive study of the nonlinear transport
+properties of magnons, which are electrically emitted or absorbed inside
+extended YIG films by spin transfer effects via a YIG$\vert$Pt interface. Our
+purpose is to experimentally elucidate the pertinent picture behind the
+asymmetric electrical variation of the magnon transconductance analogous to an
+electric diode. The feature is rooted in the variation of the density of
+low-lying spin excitations via an electrical shift of the magnon chemical
+potential. As the intensity of the spin transfer increases in the forward
+direction (regime of magnon emission), the transport properties of low-energy
+magnon go through 3 distinct regimes: \textit{i)} at low currents, where the
+spin current is a linear function of the electrical current, the spin transport
+is ballistic and set by the film thickness; \textit{ii)} for amplitudes of the
+order of the damping compensation threshold, it switches to a highly correlated
+regime limited by magnon-magnon relaxation process and marked by a saturation
+of the magnon transconductance. Here the main bias, that controls the magnon
+density, are thermal fluctuations beneath the emitter. \textit{iii)} As the
+temperature under the emitter approaches the Curie temperature, scattering with
+high-energy magnons dominates, leading to diffusive transport. We note that
+such sequence of transport regimes bears analogy with electron hydrodynamic
+transport in ultra-pure media predicted by Radii Gurzhi. This study restricted
+to low energy part of the magnon manifold complements part II of this
+review\cite{kohno_2F}, which concentrates instead on the whole spectrum of
+propagating magnons.",2210.08304v2
+2022-11-02,High Temperature Ferromagnetism in Cr$_{1+x}$Pt$_{5-x}$P,"We present the growth and basic magnetic and transport properties of
+Cr$_{1+x}$Pt$_{5-x}$P. We show that single crystals can readily be grown from a
+high-temperature solution created by adding dilute quantities of Cr to Pt-P
+based melts. Like other 1-5-1 compounds, Cr$_{1+x}$Pt$_{5-x}$P adopts a
+tetragonal P4/mmm structure composed face-sharing CrPt$_3$ like slabs that are
+broken up along the c-axis by sheets of P atoms. EDS and X-ray diffraction
+measurements both suggest Cr$_{1+x}$Pt$_{5-x}$P has mixed occupancy between Cr
+and Pt atoms, similar to what is found in the closely related compound
+CrPt$_3$, giving real compositions of Cr$_{1.5}$Pt$_{4.5}$P (x = 0.5). We
+report that Cr$_{1.5}$Pt$_{4.5}$P orders ferromagnetically at T$_C$ = 464.5 K
+with a saturated moment of $\approx$ 2.1 $\mu_{\textit{B}}$/Cr at 1.8 K. Likely
+owing to the strong spin-orbit coupling associated with the large quantity of
+high Z Pt atoms, Cr$_{1.5}$Pt$_{4.5}$P has exceptionally strong planar
+anisotropy with estimated anisotropy fields of 345 kOe and 220 kOe at 1.8 K and
+300 K respectively. The resistance of Cr$_{1.5}$Pt$_{4.5}$P has a metallic
+temperature dependence with relatively weak magnetoresistance. Electronic band
+structure calculations show that CrPt$_5$P has a large peak in the density of
+states near the Fermi level which is split into spin majority and minority
+bands in the ferromagnetic state. Furthermore, the calculations suggest
+substantial hybridization between Cr-3d and Pt-5d states near the Fermi level,
+in agreement with the experimentally measured anisotropy.",2211.01491v1
+2022-11-11,"The unaltered pulsar: GRO J1750-27, a super-critical X-ray neutron star that does not blink an eye","When accreting X-ray pulsars (XRPs) undergo bright X-ray outbursts, their
+luminosity-dependent spectral and timing features can be analysed in detail.
+The XRP GRO J1750-27 recently underwent one of such episodes, during which it
+was observed with $NuSTAR$ and monitored with $NICER$. Such a data set is
+rarely available, as it samples the outburst over more than a month at a
+luminosity that is always exceeding ${\sim}5\times10^{37}\,$erg/s. This value
+is larger than the typical critical luminosity value, where a radiative shock
+is formed above the neutron star's surface. Our data analysis of the joint
+spectra returns a highly ($N_H\sim(5-8)\times10^{22}\,$cm$^{-2}$) absorbed
+spectrum showing a K$\alpha$ iron line, a soft blackbody component likely
+originating from the inner edge of the accretion disk, and confirms the
+discovery of one of the deepest cyclotron lines, at a centroid energy of
+${\sim}44\,$keV corresponding to a magnetic field strength of
+$4.7\times10^{12}\,$G. This value is independently supported by the best-fit
+physical model for spectral formation in accreting XRPs which, in agreement
+with recent findings, favours a distance of $14$ kpc and also reflects a
+bulk-Comptonization dominated accretion flow. Contrary to theoretical
+expectations and observational evidence from other similar sources, the pulse
+profiles as observed by $NICER$ through the outburst raise, peak and decay
+remain remarkably steady. The $NICER$ spectrum, including the iron K$\alpha$
+line best-fit parameters, also remain almost unchanged at all probed outburst
+stages, similar to the pulsed fraction behaviour. We argue that all these
+phenomena are linked and interpret them as resulting from a saturation effect
+of the accretion column's emission, which occurs in the high-luminosity regime.",2211.06367v2
+2022-11-21,Magnetic activities and parameters of 43 flare stars in the GWAC archive,"In the archive of the Ground Wide Angle Camera (GWAC), we found 43 white
+light flares from 43 stars, among which, three are sympathetic or homologous
+flares, and one of them also has a quasi-periodic pulsation with a period of
+$13.0\pm1.5$ minutes. Among these 43 flare stars, there are 19 new active stars
+and 41 stars that have available TESS and/or K2 light curves, from which we
+found 931 stellar flares. We also obtained rotational or orbital periods of 34
+GWAC flare stars, of which 33 are less than 5.4 days, and ephemerides of three
+eclipsing binaries from these light curves. Combining with low resolution
+spectra from LAMOST and the Xinglong 2.16m telescope, we found that $L_{\rm
+H\alpha}/L_{\rm bol}$ are in the saturation region in the rotation-activity
+diagram. From the LAMOST medium-resolution spectrum, we found that Star \#3
+(HAT 178-02667) has double H$\alpha$ emissions which imply it is a binary, and
+two components are both active stars. Thirteen stars have flare frequency
+distributions (FFDs) from TESS and/or K2 light curves. These FFDs show that the
+flares detected by GWAC can occur at a frequency of 0.5 to 9.5 yr$^{-1}$. The
+impact of flares on habitable planets was also studied based on these FFDs, and
+flares from some GWAC flare stars may produce enough energetic flares to
+destroy ozone layers, but none can trigger prebiotic chemistry on their
+habitable planets.",2211.11240v1
+2023-01-10,Cosmic Ray Drag and Damping of Compressive Turbulence,"While it is well-known that cosmic rays (CRs) can gain energy from turbulence
+via second order Fermi acceleration, how this energy transfer affects the
+turbulent cascade remains largely unexplored. Here, we show that damping and
+steepening of the compressive turbulent power spectrum are expected once the
+damping time $t_{\rm damp} \sim \rho v^{2}/\dot{E}_{\rm CR} \propto E_{\rm
+CR}^{-1}$ becomes comparable to the turbulent cascade time. Magnetohydrodynamic
+(MHD) simulations of stirred compressive turbulence in a gas-CR fluid with
+diffusive CR transport show clear imprints of CR-induced damping, saturating at
+$\dot{E}_{\rm CR} \sim \tilde{\epsilon}$, where $\tilde{\epsilon}$ is the
+turbulent energy input rate. In that case, almost all the energy in large scale
+motions is absorbed by CRs and does not cascade down to grid scale. Through a
+Hodge-Helmholtz decomposition, we confirm that purely compressive forcing can
+generate significant solenoidal motions, and we find preferential CR damping of
+the compressive component in simulations with diffusion and streaming,
+rendering small-scale turbulence largely solenoidal, with implications for
+thermal instability and proposed resonant scattering of $E > 300$ GeV CRs by
+fast modes. When CR transport is streaming dominated, CRs also damp large scale
+motions, with kinetic energy reduced by up to to an order of magnitude in
+realistic $E_{\rm CR} \sim E_{\rm g}$ scenarios, but turbulence (with a reduced
+amplitude) still cascades down to small scales with the same power spectrum.
+Such large scale damping implies that turbulent velocities obtained from the
+observed velocity dispersion may significantly underestimate turbulent forcing
+rates, i.e. $\tilde{\epsilon} \gg \rho v^{3}/L$.",2301.04156v2
+2023-01-11,Heat transport and convective velocities in compositionally-driven convection in neutron star and white dwarf interiors,"We investigate heat transport associated with compositionally-driven
+convection driven by crystallization at the ocean-crust interface in accreting
+neutron stars, or growth of the solid core in cooling white dwarfs. We study
+the effect of thermal diffusion and rapid rotation on the convective heat
+transport, using both mixing length theory and numerical simulations of
+Boussinesq convection. We determine the heat flux, composition gradient and
+P\'eclet number, $\mathrm{Pe}$ (the ratio of thermal diffusion time to
+convective turnover time) as a function of the composition flux. We find two
+regimes of convection with a rapid transition between them as the composition
+flux increases. At small Pe, the ratio between the heat flux and composition
+flux is independent of Pe,, because the loss of heat from convecting fluid
+elements due to thermal diffusion is offset by the smaller composition gradient
+needed to overcome the reduced thermal buoyancy. At large Pe, the temperature
+gradient approaches the adiabatic gradient, saturating the heat flux. We
+discuss the implications for neutron star and white dwarf cooling. Convection
+in neutron stars spans both regimes. We find rapid mixing of neutron star
+oceans, with a convective turnover time of order weeks to minutes depending on
+rotation. Except during the early stages of core crystallization, white dwarf
+convection is in the thermal-diffusion-dominated fingering regime. We find
+convective velocities much smaller than recent estimates for
+crystallization-driven dynamos. The small fraction of energy carried as kinetic
+energy calls into question the effectiveness of crystallization-driven dynamos
+as an explanation for observed white dwarf magnetic fields.",2301.04273v3
+2023-01-14,On the Generation and Evolution of Switchbacks and the Morphology of Alfvénic Transition: Low Mach-number Boundary Layers,"We investigate the generation and evolution of switchbacks (SBs), the nature
+of the sub-Alfv\'enic wind observed by Parker Solar Probe (PSP), and the
+morphology of the Alfv\'enic transition, all of which are key issues in solar
+wind research. First we highlight a special structure in the pristine solar
+wind, termed a low Mach-number boundary layer (LMBL). An increased Alfv\'en
+radius and suppressed SBs are observed within an LMBL. A probable source on the
+Sun for an LMBL is the peripheral region inside a coronal hole with rapidly
+diverging open fields. The sub-Alfv\'enic wind detected by PSP is an LMBL flow
+by nature. The similar origin and similar properties of the sub-Alfv\'enic
+intervals favor a wrinkled surface for the morphology of the Alfv\'enic
+transition. We find that a larger deflection angle tends to be associated with
+a higher Alfv\'en Mach number. The magnetic deflections have an origin well
+below the Alfv\'en critical point, and deflection angles larger than
+$90^{\circ}$ seem to occur only when $M_{\rm A} \gtrsim 2$. The velocity
+enhancement in units of the local Alfv\'en speed generally increases with the
+deflection angle, which is explained by a simple model. A nonlinearly evolved,
+saturated state is revealed for SBs, where the local Alfv\'en speed is roughly
+an upper bound for the velocity enhancement. In the context of these results,
+the most promising theory on the origin of SBs is the model of expanding waves
+and turbulence, and the patchy distribution of SBs is attributed to modulation
+by reductions in the Alfv\'en Mach number. Finally, a picture on the generation
+and evolution of SBs is created based on the results.",2301.05829v1
+2023-03-02,Synchrotron Radiation Dominates the Extremely Bright GRB 221009A,"The brightest Gamma-ray burst, GRB 221009A, has spurred numerous theoretical
+investigations, with particular attention paid to the origins of ultra-high
+energy TeV photons during the prompt phase. However, analyzing the mechanism of
+radiation of photons in the $\sim$MeV range has been difficult because the high
+flux causes pile-up and saturation effects in most GRB detectors. In this
+letter, we present systematic modeling of the time-resolved spectra of the GRB
+using unsaturated data obtained from Fermi/GBM (precursor) and
+SATech-01/GECAM-C (main emission and flare). Our approach incorporates the
+synchrotron radiation model, which assumes an expanding emission region with
+relativistic speed and a global magnetic field that decays with radius, and
+successfully fits such a model to the observational data. Our results indicate
+that the spectra of the burst are fully in accordance with a synchrotron origin
+from relativistic electrons accelerated at a large emission radius. The lack of
+thermal emission in the prompt emission spectra supports a
+Poynting-flux-dominated jet composition.",2303.00898v2
+2023-07-04,On electromagnetic turbulence and transport in STEP,"In this work, we present first-of-their-kind nonlinear local gyrokinetic
+simulations of electromagnetic turbulence at mid-radius in the burning plasma
+phase of the conceptual high-$\beta$, reactor-scale, tight-aspect-ratio tokamak
+STEP (Spherical Tokamak for Energy Production). A prior linear analysis in D.
+Kennedy et al. 2023 Nucl. Fusion 63 126061 reveals the presence of unstable
+hybrid kinetic ballooning modes, where inclusion of the compressional magnetic
+field fluctuation, $\delta B_{\parallel}$, is crucial, and subdominant
+microtearing modes are found at binormal scales approaching the ion-Larmor
+radius. Local nonlinear gyrokinetic simulations on the selected surface in the
+central core region suggest that hybrid kinetic ballooning modes can drive
+large turbulent transport, and that there is negligible turbulent transport
+from subdominant microtearing modes when hybrid kinetic ballooning modes are
+artificially suppressed (through the omission of $\delta B_{\parallel}$).
+Nonlinear simulations that include perpendicular equilibrium flow shear can
+saturate at lower fluxes that are more consistent with the available sources in
+STEP. This analysis suggests that hybrid kinetic ballooning modes could play an
+important role in setting the turbulent transport in STEP, and possible
+mechanisms to mitigate turbulent transport are discussed. Increasing the safety
+factor or the pressure gradient strongly reduces turbulent transport from
+hybrid kinetic ballooning modes in the cases considered here. Challenges of
+simulating electromagnetic turbulence in this high-$\beta$ regime are
+highlighted. In particular the observation of radially extended turbulent
+structures in the absence of equilibrium flow shear motivates future advanced
+global gyrokinetic simulations that include $\delta B_\parallel$.",2307.01669v3
+2023-11-12,"Three young planets around the K-dwarf K2-198: High-energy environment, evaporation history and expected future","Planets orbiting young stars are thought to experience atmospheric
+evaporation as a result of the host stars' high magnetic activity. We study the
+evaporation history and expected future of the three known transiting
+exoplanets in the young multiplanet system K2-198. Based on spectroscopic and
+photometric measurements, we estimate an age of the K-dwarf host star between
+200 and 500 Myr, and calculate the high-energy environment of these planets
+using eROSITA X-ray measurements. We find that the innermost planet K2-198c has
+likely lost its primordial envelope within the first few tens of Myr regardless
+of the age at which the star drops out of the saturated X-ray regime. For the
+two outer planets, a range of initial envelope mass fractions is possible,
+depending on the not-yet-measured planetary mass and the stars' spin-down
+history. Regarding the future of the system, we find that the outermost planet
+K2-198b is stable against photoevaporation for a wide range of planetary
+masses, while the middle planet K2-198d is only able to retain an atmosphere
+for a mass range between ~7 and 18 Earth-masses. Lower-mass planets are too
+susceptible to mass loss, and a very thin present-day envelope for higher-mass
+planets is easily lost with the estimated mass-loss rates. Our results support
+the idea that all three planets started out above the radius valley in the
+(sub-)Neptune regime and were then transformed into their current states by
+atmospheric evaporation, but also stress the importance of measuring planetary
+masses for (young) multiplanet systems before conducting more detailed
+photoevaporation simulations.",2311.06897v1
+1996-05-02,A Procedure for Correcting the Apparent Optical Depths of Moderately Saturated Interstellar Absorption Lines,"Most observations of absorption lines from interstellar and intergalactic
+matter have sufficient resolution to show most of the structure at differing
+radial velocities of the absorber. In analyzing the lines, however, it is
+important to sense and correct for the fact that some parts of a profile may
+have some very narrow structures that are saturated and then degraded by the
+convolution of the true spectrum by the instrumental profile. This can be done
+by comparing at each velocity the apparent optical depths of two lines that
+have significantly different transition probabilities. If their ratio is
+smaller than the ratio of the lines' values of f(lambda), the actual saturation
+is more severe than that indicated by the raw optical depths. This paper
+describes a simple procedure for selectively boosting apparent optical depth of
+the weaker of the two lines at each velocity value, so that unresolved
+saturated structure is accounted for, thus yielding a very nearly correct
+answer for the column density per unit velocity. Some test examples that
+demonstrate the use of the correction method are given, along with a simple
+recipe for invoking it.",9605010v1
+2002-02-19,Saturation of the R-mode Instability,"Rossby waves (r-modes) in rapidly rotating neutron stars are unstable because
+of the emission of gravitational radiation. We study saturation of this
+instability by nonlinear transfer of energy to stellar ""inertial"" oscillation
+modes. We present detailed calculations of stellar inertial modes in the WKB
+limit, their linear damping by bulk and shear viscosity, and the nonlinear
+coupling forces among these modes. The saturation amplitude is derived in the
+extreme limits of strong or weak driving by radiation reaction, as compared to
+the damping rate of low order inertial modes. We find the saturation energy is
+{\it extremely small}, at least four orders of magnitude smaller than that
+found by previous investigators. We discuss the consequences of this result for
+spin evolution of young neutron stars, and neutron stars being spun up by
+accretion in Low Mass X-ray Binaries.We also discuss the detection of these
+gravitational waves by LIGO.",0202345v2
+2000-07-26,Universal saturation of electron dephasing in three-dimensional disordered metals,"We have systematically investigated the low-temperature electron dephasing
+times $\tau_\phi$ in more than 40 three-dimensional polycrystalline impure
+metals with distinct material characteristics. In all cases, a saturation of
+the dephasing time is observed below about a (few) degree(s) Kelvin, depending
+on samples. The value of the saturated dephasing time $\tau_0$ [$\equiv
+\tau_\phi (T \to 0 {\rm K})$] falls basically in the range 0.005 to 0.5 ns for
+all samples. Particularly, we find that $\tau_0$ scales with the electron
+diffusion constant $D$ as $\tau_0 \sim D^{- \alpha}$, with $\alpha$ close to or
+slightly larger than 1, for over two decades of $D$ from about 0.1 to 10
+cm$^2$/s. Our observation suggests that the saturation behavior of $\tau_\phi$
+is universal and intrinsic in three-dimensional polycrystalline impure metals.
+A complete theoretical explanation is not yet available.",0007417v2
+2002-12-24,Density-of-states picture and stability of ferromagnetism in the highly-correlated Hubbard model,"The problem of stability of saturated and non-saturated ferromagnetism in the
+Hubbard model is considered in terms of the one-particle Green's functions.
+Approximations by Edwards and Hertz and some versions of the self-consistent
+approximations based on the 1/z-expansion are considered. The account of
+longitudinal fluctuations turns out to be essential for description of the
+non-saturated state. The corresponding pictures of density of states are
+obtained. ""Kondo"" density-of-states singularities owing to spin-flip processes
+are analyzed. The critical electron concentrations for instabilities of
+saturated ferromagnetism and paramagnetic state are calculated for various
+lattices. Drawbacks of various approximations are discussed. A comparison with
+the results of previous works is performed.",0212586v2
+2003-02-03,Scattering of signal in vertical granular chain with impurities,"We investigate the scattering process of impulse from impurities in vertical
+granular chain system under gravity. Most of the studies are focused on the
+case of light impurities. The reflection rates follow power laws with the
+impuity depth. There is a valley in the curve of reflection rate versus the
+initial perturbation strength and the curve is not symmetric. Some results on
+the scattering process from heavy impurities are also presented. There is a
+transition region in the initial velocity space. Through this region the
+exponent for leading peak changes smoothly from its saturant value in small $
+v_i$ side to its saturant value in large $v_i$ side; the exponent for signal
+speed changes smoothly from its saturant value in small $v_i$ side to its
+saturant value in large $v_i$ side. Both the peak of the exponent for
+reflection rate and the valley for the reflection rate versus $v_i$ also locate
+within this transition region.",0302055v2
+2003-03-04,Spin-sensitive Bleaching and Spin-Relaxation in QW's,"Spin-sensitive saturation of absorption of infrared radiation has been
+investigated in p-type GaAs QWs. It is shown that the absorption saturation of
+circularly polarized radiation is mostly controlled by the spin relaxation time
+of the holes. The saturation behavior has been investigated for different QW
+widths and in dependence on the temperature with the result that the saturation
+intensity substantially decreases with narrowing of QWs. Spin relaxation times
+were experimentally obtained by making use of calculated (linear) absorption
+coefficients for inter-subband transitions.",0303056v1
+2003-05-17,Saturation of electrical resistivity,"Resistivity saturation is observed in many metallic systems with a large
+resistivity, i.e., when the resistivity has reached a critical value, its
+further increase with temperature is substantially reduced. This typically
+happens when the apparent mean free path is comparable to the interatomic
+separations - the Ioffe-Regel condition. Recently, several exceptions to this
+rule have been found. Here, we review experimental results and early theories
+of resistivity saturation. We then describe more recent theoretical work,
+addressing cases both where the Ioffe-Regel condition is satisfied and where it
+is violated. In particular we show how the (semiclassical) Ioffe-Regel
+condition can be derived quantum-mechanically under certain assumptions about
+the system and why these assumptions are violated for high-Tc cuprates and
+alkali-doped fullerides.",0305412v1
+2004-02-24,Spin relaxation times of 2D holes from spin sensitive bleaching of inter-subband absorption,"We present spin relaxation times of 2D holes obtained by means of spin
+sensitive bleaching of the absorption of infrared radiation in p-type
+GaAs/AlGaAs quantum wells (QWs). It is shown that the saturation of
+inter-subband absorption of circularly polarized radiation is mainly controlled
+by the spin relaxation time of the holes. The saturation behavior has been
+determined for different QW widths and in a wide temperature range with the
+result that the saturation intensity substantially decreases with narrowing of
+the QWs. Spin relaxation times are derived from the measured saturation
+intensities by making use of calculated (linear) absorption coefficients for
+direct inter-subband transitions. It is shown that spin relaxation is due to
+the D'yakonov-Perel' mechanism governed by hole-hole scattering. The problem of
+selection rules is addressed.",0402572v1
+2006-03-13,The quantum paraelectric behavior of SrTiO_{3} revisited: relevance of the structural phase transition temperature,"It has been known for a long time that the low temperature behavior shown by
+the dielectric constant of quantum paraelectric $SrTiO_{3}$ can not be fitted
+properly by Barrett's formula using a single zero point energy or saturation
+temperature ($T_{1}$). As it was originally shown [K. A. M\""{u}ller and H.
+Burkard, Phys. Rev. B {\bf 19}, 3593 (1979)] a crossover between two different
+saturation temperatures ($T_{1l}$=77.8K and $T_{1h}$=80K) at $T\sim10K$ is
+needed to explain the low and high temperature behavior of the dielectric
+constant. However, the physical reason for the crossover between these two
+particular values of the saturation temperature at $T\sim10K$ is unknown. In
+this work we show that the crossover between these two values of the saturation
+temperature at $T\sim10K$ can be taken as a direct consequence of (i) the
+quantum distribution of frequencies $g(\Omega)\propto\Omega^{2}$ associated
+with the complete set of low-lying modes and (ii) the existence of a definite
+maximum phonon frequency given by the structural transition critical
+temperature $T_{tr}$.",0603354v1
+2006-04-02,Universal low-temperature behavior of frustrated quantum antiferromagnets in the vicinity of the saturation field,"We study the low-temperature thermodynamic properties of a number of
+frustrated quantum antiferromagnets which support localized magnon states in
+the vicinity of the saturation field. For this purpose we use 1) a mapping of
+the low-energy degrees of freedom of spin systems onto the hard-core object
+lattice gases and 2) an exact diagonalization of finite spin systems of up to
+N=30 sites. The considered spin systems exhibit universal behavior which is
+determined by a specific hard-core object lattice gas representing the
+independent localized magnon states. We test the lattice gas description by
+comparing its predictions with the numerical results for low-lying energy
+states of finite spin systems. For all frustrated spin systems considered we
+find a strong variation of the low-temperature specific heat passing the
+saturation field and a maximum in the isothermal entropy at saturation field
+resulting in an enhanced magnetocaloric effect.",0604023v1
+2006-08-17,Random Sequential Addition of Hard Spheres in High Euclidean Dimensions,"Employing numerical and theoretical methods, we investigate the structural
+characteristics of random sequential addition (RSA) of congruent spheres in
+$d$-dimensional Euclidean space $\mathbb{R}^d$ in the infinite-time or
+saturation limit for the first six space dimensions ($1 \le d \le 6$).
+Specifically, we determine the saturation density, pair correlation function,
+cumulative coordination number and the structure factor in each =of these
+dimensions. We find that for $2 \le d \le 6$, the saturation density $\phi_s$
+scales with dimension as $\phi_s= c_1/2^d+c_2 d/2^d$, where $c_1=0.202048$ and
+$c_2=0.973872$. We also show analytically that the same density scaling
+persists in the high-dimensional limit, albeit with different coefficients. A
+byproduct of this high-dimensional analysis is a relatively sharp lower bound
+on the saturation density for any $d$ given by $\phi_s \ge
+(d+2)(1-S_0)/2^{d+1}$, where $S_0\in [0,1]$ is the structure factor at $k=0$
+(i.e., infinite-wavelength number variance) in the high-dimensional limit.
+Consistent with the recent ""decorrelation principle,"" we find that pair
+correlations markedly diminish as the space dimension increases up to six. Our
+work has implications for the possible existence of disordered classical ground
+states for some continuous potentials in sufficiently high dimensions.",0608402v1
+2000-07-18,Geometric scaling for the total gamma^* p cross section in the low x region,"We observe that the saturation model of deep inelastic scattering, which
+successfully describes inclusive and diffractive data at small x, predicts a
+geometric scaling of the total gamma^* p cross section in the region of small
+Bjorken variable x. The geometric scaling in this case means that the cross
+section is a function of only one dimensionless variable tau = Q^2 R_0^2(x),
+where the function R_0(x) (called saturation radius) decreases with decreasing
+x. We show that the experimental data from HERA in the region x<0.01 confirm
+the expectations of this scaling over a very broad region of Q^2. We suggest
+that the geometric scaling is more general than the saturation model.",0007192v2
+2001-03-02,Saturation and Universality in QCD at small x,"We find approximate solutions to the renormalization group equation which
+governs the quantum evolution of the effective theory for the Color Glass
+Condensate. This is a functional Fokker-Planck equation which generates in
+particular the non-linear evolution equations previously derived by Balitsky
+and Kovchegov within perturbative QCD. In the limit where the transverse
+momentum of the external probe is large compared to the saturation momentum,
+our approximations yield the Gaussian Ansatz for the effective action of the
+McLerran-Venugopalan model. In the opposite limit, of a small external
+momentum, we find that the effective theory is governed by a scale-invariant
+universal action which has the correct properties to describe gluon saturation.",0103032v2
+2001-03-27,The Transverse Energy as a Barometer of a Saturated Plasma,"The evolution of the gluon plasma produced with saturation initial conditions
+is calculated via Boltzmann transport theory for nuclear collisions at high
+energy. The saturation scale increases with the nuclear size and the beam
+energy, and thus we find that the perturbative rescattering rate decreases
+relative to the initial longitudinal expansion rate of the plasma. The
+effective longitudinal pressure remains significantly below the lattice QCD
+pressure until the plasma cools to near the confinement scale. Therefore, the
+transverse energy per unit of rapidity and its dependence on beam energy
+provides a sensitive test of gluon saturation models: the fractional transverse
+energy loss due to final state interactions is smaller and exhibits a weaker
+energy dependence than if ideal (nondissipative) hydrodynamics applied
+throughout the evolution.",0103291v1
+2001-08-29,Diffractive dissociation and saturation scale from non-linear evolution in high energy DIS,"This paper presents the first numerical solution to the non-linear evolution
+equation for diffractive dissociation processes in deep inelastic scattering.
+It is shown that the solution depends on one scaling variable $\tau = Q^2/Q^{D
+2}_s(x,x_0)$, where $Q^D_s(x,x_0)$ is the saturation scale for the diffraction
+processes. The dependence of the saturation scale $Q^D_s(x,x_0)$ on both $x$
+and $x_0$ is investigated, ($Y_0 = \ln(1/x_0)$ is a minimal rapidity gap for
+the diffraction process). The $x$ - dependence of $Q^D_s$ turns out to be the
+same as of the saturation scale in the total inclusive DIS cross section. In
+our calculations $Q^D_s(x,x_0)$ reveals only mild dependence on $x_0$. The
+scaling is shown to hold for $x \ll x_0$ but is violated at $ x \sim x_0$.",0108239v1
+2001-10-31,Saturation model for two-photon interactions at high energies,"We formulate and analyse a saturation model for the total gamma gamma and
+gamma* gamma* cross-sections and for the real photon structure function
+F_2^gamma(x,Q^2). The model is based on a picture in which the gamma* gamma*
+total cross-section for arbitrary photon virtualities is driven by the
+interaction of colour dipoles, into which the virtual photons fluctuate. The
+cross-section describing this interaction is assumed to satisfy the saturation
+property with the saturation radius taken from the Golec-Biernat and Wusthoff
+analysis of the gamma* p interaction at HERA. The model is supplemented by the
+QPM and non-pomeron reggeon contributions. The model gives a very good
+description of the data on the gamma gamma total cross-section, on the photon
+structure function F_2^gamma(x,Q^2) at low x and on the gamma* gamma*
+cross-section extracted from LEP double tagged events. Production of heavy
+flavours in gamma gamma collisions is also studied. Predictions of the model
+for the very high energy range which will be probed at future linear colliders
+are given.",0110409v1
+2002-05-18,Understanding Geometric Scaling at Small x,"Geometric scaling is a novel scaling phenomenon observed in deep inelastic
+scattering at small x: the total virtual photon-proton cross section depends
+upon the two kinematical variables Q^2 and x only via their combination Q^2
+R_0^2(x), with R_0^2(x) \propto x^{\lambda}. At sufficiently low Q^2, below the
+saturation scale Q_s^2(x) (a few GeV^2), this phenomenon finds a natural
+explanation as a property of the Color Glass Condensate, the high-density
+matter made of saturated gluons. To explain the experimental observation of
+geometric scaling up to much higher values of Q^2, of the order of 100 GeV^2,
+we study the solution to the BFKL equation subjected to a saturation boundary
+condition at Q^2\sim Q_s^2(x). We find that the scaling extends indeed above
+the saturation scale, within a window 1 < \ln(Q^2/Q_s^2) <<
+\ln(Q_s^2/\Lambda^2_{\rm QCD}), which is consistent with phenomenology.",0205198v1
+2002-06-14,Two-photon cross-sections from the saturation model,"A saturation model for the total gamma-gamma and gamma*-gamma* cross-sections
+and for the real photon structure function F_2^gamma(x,Q^2) is described. The
+model is based on a QCD dipole picture of high energy scattering. The
+two-dipole cross-section is assumed to satisfy the saturation property with the
+saturation radius taken from the GBW analysis of the gamma*-p interaction at
+HERA. The model is combined with the QPM and non-pomeron reggeon contributions
+an it gives a very good description of the data on the gamma-gamma total
+cross-section, on the photon structure function F_2^gamma(x,Q^2) at low x and
+on the gamma*-gamma* cross-section. Production of heavy quarks in gamma-gamma
+collisions is also studied.",0206129v1
+2003-01-21,QCD-Instantons and Saturation at Small x,"We briefly report on the contribution of QCD-instantons to the phenomenon of
+saturation in deep-inelastic scattering (DIS) at small Bjorken-x. The
+explicitly known instanton gauge field serves as a concrete realization of an
+underlying non-perturbative saturation mechanism associated with strong
+classical fields. Two independent strategies were pursued, with consistent
+results: On the one hand, an approach starting from instanton-perturbation
+theory was considered and on the other hand, the scattering of a Wilson loop in
+an instanton gauge field background. In both cases, the conspicuous, intrinsic
+instanton size scale <rho> ~ 0.5 fm, as known from the lattice, turns out to
+determine the saturation scale.",0301177v1
+2003-02-20,Anatomy of QCD Strings and Saturation Effects in High-Energy Scattering,"We develop a model to compute high-energy reactions of hadrons and photons.
+The perturbative interaction is described by gluon exchange and the
+non-perturbative interaction by the stochastic vacuum model which leads to
+quark-confinement in dipoles via a string of color fields. We study the QCD
+structure of the dipole-dipole scattering in momentum space focussing
+especially on interactions between strings. We represent the string as a
+collection of stringless dipoles, show confinement effects in high-energy
+scattering and calculate unintegrated gluon distributions of hadrons and
+photons. In the impact parameter space of the scattering process we investigate
+the unitarity limit of the S-matrix. We calculate the impact parameter profiles
+for proton-proton and photon-proton scattering, determine the energy values at
+which the profiles saturate at the black disc limit, estimate the impact
+parameter dependent gluon distribution of the proton and discuss gluon
+saturation. We compare the model results for p p, pi p, K p, gamma p and gamma
+gamma reactions with experimental data and identify saturation effects in
+experimental observables.",0302179v1
+2003-04-21,An Impact Parameter Dipole Saturation Model,"We develop a dipole model for HERA DIS data which incorporates the impact
+parameter distribution of the proton. The model describes the inclusive total
+$\gamma^*p$ cross-sections as well as the diffractive $J/\psi$ differential
+cross-sections. We compare the model with previous approaches and show that the
+$t$-distributions are sensitive to saturation phenomena. We estimate the
+boundary of the saturation region and show that it dominates the data in the
+low-$Q^2$ region where the total $\gamma^*p$ cross-section exhibits the same
+universal rise as hadronic cross-sections. The model is then extended to nuclei
+and shows good agreement with the nuclear shadowing data at small-$x$. Finally,
+we estimate the saturation scale in nuclei.",0304189v3
+2003-08-06,Saturation Physics in Heavy Ion Collisions,"We discuss expectations of saturation physics for various observables in
+heavy ion collisions. We show how simple saturation-inspired assumptions about
+particle production in heavy ion collisions lead to Kharzeev-Levin-Nardi model.
+Comparing this model to RHIC data on particle multiplicities we conclude that
+saturation effects may play an important role in particle production and
+dynamics at the early stages of Au-Au collisions already at RHIC energies. We
+then estimate the contribution of the initial state two-particle azimuthal
+correlations to elliptic flow observable v_2 in Au-Au collisions by
+constructing a lower bound on these non-flow effects based on v_2 obtained from
+the analysis of proton-proton (pp) collisions.",0308076v1
+2004-03-26,Jet Azimuthal Correlations and Parton Saturation in the Color Glass Condensate,"We consider the influence of parton saturation in the Color Glass Condensate
+on the back-to-back azimuthal correlations of high $p_T$ hadrons in $pA$ (or
+$dA$) collisions. When both near--side and away--side hadrons are detected at
+mid-rapidity at RHIC energy, the effects of parton saturation are constrained
+to transverse momenta below the saturation scale $p_T \leq Q_s$; in this case
+the back-to-back correlations do not disappear but exhibit broadening. However
+when near-side and away-side hadrons are separated by several units of
+rapidity, quantum evolution effects lead to the depletion of back-to-back
+correlations as a function of rapidity interval between the detected hadrons
+(at fixed $p_T$). This applies to both $pp$ and $pA$ (or $dA$) collisions;
+however, due to the initial conditions provided by the Color Glass Condensate,
+the depletion of the back-to-back correlations is significantly stronger in the
+$pA$ case. An experimental study of this effect would thus help to clarify the
+origin of the high $p_T$ hadron suppression at forward rapidities observed
+recently at RHIC.",0403271v1
+2004-05-21,Small-x physics near the saturation regime,"We consider the T-matrix near the unitarity limit and the energy dependence
+of the saturation momentum. We discuss the solution to the Kovchegov equation,
+or equivalently, to the BFKL evolution in the presence of a single saturation
+boundary. We include some of the correlations missed in the Kovchegov equation
+by solving the BFKL equation in the presence of two boundaries. The T-matrix
+now turns out to be frame-independent, which was not the case for the solution
+in the case of a single boundary, and it doesn't show the scaling behavior of
+the solution to the Kovchegov equation. We find for the saturation momentum an
+energy dependence which differs from the one following from the Kovchegov
+equation.",0405205v1
+2005-04-18,Solution to the Balitsky-Kovchegov equation in the saturation domain,"The solution to the Balitsky-Kovchegov equation is found in the deep
+saturation domain. The controversy between different approaches regarding the
+asymptotic behaviour of the scattering amplitude is solved. It is shown that
+the dipole amplitude behaves as $ 1 - \exp (- z + \ln z)$ with $ z = \ln (r^2
+Q^2_s)$ ($ r$ -size of the dipole, $Q_s$ is the saturation scale) in the deep
+saturation region. This solution is developed from the scaling solution to the
+homogeneous Balitsky-Kovchegov equation. The dangers associated with making
+simplifications in the BFKL kernel, to investigate the asymptotic behaviour of
+the scattering amplitude, is pointed out . In particular, the fact that the
+Balitsky-Kovchegov equation belongs to the
+Fisher-Kolmogorov-Petrovsky-Piscounov -type of equation, needs further careful
+investigation.",0504146v1
+2005-04-23,Testing saturation with diffractive jet production in deep inelastic scattering,"We analyse the dissociation of a photon in diffractive deep inelastic
+scattering in the kinematic regime where the diffractive mass is much bigger
+than the photon virtuality. We consider the dominant q\bar{q}g component
+keeping track of the transverse momentum of the gluon which can be measured as
+a final-state jet. We show that the diffractive gluon-jet production
+cross-section is strongly sensitive to unitarity constraints. In particular, in
+a model with parton saturation, this cross-section is sensitive to the scale at
+which unitarity effects become important, the saturation scale. We argue that
+the measurement of diffractive jets at HERA in the limit of high diffractive
+mass can provide useful information on the saturation regime of QCD.",0504214v2
+2005-08-01,Has saturation physics been observed in deuteron-gold collisions at RHIC?,"In the framework of the recently proposed saturation picture, we examine in a
+systematic way whether the nuclear modification factor measured for d-Au
+collisions at RHIC may be simply explained. The Cronin peak which is obtained
+at mid-rapidity around $k_{\bot}\simeq 3$ GeV may be reproduced at the proper
+height only by boosting the saturation momentum by an additional nuclear
+component as already shown in the literature. In this respect, mid-rapidity
+RHIC data cannot necessarily be seen as a probe of the saturation picture. The
+large rapidity ($\eta\simeq 3$) region allows us to test the shape of the
+unintegrated gluon distribution in the nucleus, investigating various
+parameterizations inspired by large rapidity solutions (of the BFKL and) of the
+Balitsky-Kovchegov (BK) equation. A satisfactory description of $R_{CP}$ at
+RHIC is obtained in the BK picture.",0508026v2
+2005-11-17,Traveling waves in high energy QCD,"Saturation is expected to occur when a high density of partons (mainly
+gluons)- or equivalently strong fields in Quantum Chromodynamics (QCD) - is
+realized in the weak coupling regime. A way to reach saturation is through the
+high-energy evolution of an extended target probed at a fixed hard scale. In
+this case, the transition to saturation is expected to occur from nonlinear
+perturbative QCD dynamics. We discuss this approach to saturation, which is
+mathematically characterized by the appearance of traveling wave patterns in a
+suitable kinematical representation. A short review on traveling waves in high
+energy QCD and a first evidence of this phenomenon in deep-inelastic proton
+scattering are presented.",0511214v1
+1999-10-07,BPS Saturated Solitons in N=2 Two-Dimensional Theories on RxS (Domain Walls in Theories with Compactified Dimensions),"We discuss topologically stable solitons in two-dimensional theories with the
+extended supersymmetry assuming that the spatial coordinate is compact. This
+problem arises in the consideration of the domain walls in the popular theories
+with compactified extra dimensions. Contrary to naive expectations, it is shown
+that the solitons on the cylinder can be BPS saturated. In the case of one
+chiral superfield, a complete theory of the BPS saturated solitons is worked
+out. We describe the classical solutions of the BPS equations. Depending on the
+choice of the Kahler metric, the number of such solutions can be arbitrarily
+large. Although the property of the BPS saturation is preserved order by order
+in perturbation theory, nonperturbative effects eliminate the majority of the
+classical BPS states upon passing to the quantum level. The number of the
+quantum BPS states is found. It is shown that the N=2 field theory includes an
+auxiliary N=1 quantum mechanics, Witten's index of which counts the number of
+the BPS particles.",9910071v1
+2000-06-04,Leaving the BPS bound: Tunneling of classically saturated solitons,"We discuss quantum tunneling between classically BPS saturated solitons in
+two-dimensional theories with N=2 supersymmetry and a compact space dimension.
+Genuine BPS states form shortened multiplets of dimension two. In the models we
+consider there are two degenerate shortened multiplets at the classical level,
+but there is no obstruction to pairing up through quantum tunneling. The
+tunneling amplitude in the imaginary time is described by instantons. We find
+that the instanton is nothing but the 1/4 BPS saturated ``wall junction,''
+considered previously in the literature in other contexts. Two central charges
+of the superalgebra allow us to calculate the instanton action without finding
+the explicit solution (it is checked, though, numerically, that the saturated
+solution does exist). We present a quantum-mechanical interpretation of the
+soliton tunneling.",0006026v1
+2005-01-06,Heisenberg saturation of the Froissart bound from AdS-CFT,"In a previous paper, we have analyzed high energy QCD from AdS-CFT and proved
+the saturation of the Froissart bound (a purely QCD proof of which is still
+lacking). In this paper we describe the calculation in more physical terms and
+map it to QCD language. We find a remarkable agreement with the 1952 Heisenberg
+description of the saturation (pre-QCD!) in terms of shockwave collisions of
+pion field distributions. It provides a direct map between gauge theory physics
+and the gravitational physics on the IR brane of the Randall-Sundrum model.
+Saturation occurs through black hole production on the IR brane, which is in
+QCD production of a nonlinear pion field soliton of a Born-Infeld action in the
+hadron collision, that decays into free pions.",0501038v2
+1999-08-01,Notions of denseness,"The notion of a completely saturated packing [Fejes Toth, Kuperberg and
+Kuperberg, Highly saturated packings and reduced coverings, Monats. Math. 125
+(1998) 127-145] is a sharper version of maximum density, and the analogous
+notion of a completely reduced covering is a sharper version of minimum
+density. We define two related notions: uniformly recurrent and weakly
+recurrent dense packings, and diffusively dominant packings. Every compact
+domain in Euclidean space has a uniformly recurrent dense packing. If the
+domain self-nests, such a packing is limit-equivalent to a completely saturated
+one. Diffusive dominance is yet sharper than complete saturation and leads to a
+better understanding of n-saturation.",9908003v3
+2001-06-04,Subsymmetric sequences and minimal spaces,"We show that every Banach space saturated with subsymmetric sequences
+contains a minimal subspace.",0106023v2
+2003-02-19,Topologische und algebraische Filter,"We provide the set of filters (saturated submonoids) in a commutative monoid
+with a topology (like the spectrum of a ring) and study the resulting spaces.",0302235v1
+2004-04-06,Determinantal processes with number variance saturation,"Consider Dyson's Hermitian Brownian motion model after a finite time S, where
+the process is started at N equidistant points on the real line. These N points
+after time S form a determinantal process and has a limit as N tends to
+infinity. This limting determinantal proceess has the interesting feature that
+it shows number variance saturation. The variance of the number of particles in
+an interval converges to a limiting value as the length of the interval goes to
+infinity. Number variance saturation is also seen for example in the zeros of
+the Riemann zeta function (Odlyzko, Berry). The process can also be constructed
+using non-intersecting paths and we consider several variants of this
+construction. One construction leads to a model which shows a transition from a
+non-universal behaviour with number variance saturation to a universal
+sine-kernel behaviour as we go up the line.",0404133v1
+2007-03-19,Algebraization of complex analytic varieties and derived categories,"We prove that a compact complex analytic variety is algebraizable if and only
+if its bounded derived dg-category of coherent sheaves is saturated.",0703555v1
+1998-05-15,Resonance trapping and saturation of decay widths,"Resonance trapping appears in open many-particle quantum systems at high
+level density when the coupling to the continuum of decay channels reaches a
+critical strength. Here a reorganization of the system takes place and a
+separation of different time scales appears. We investigate it under the
+influence of additional weakly coupled channels as well as by taking into
+account the real part of the coupling term between system and continuum. We
+observe a saturation of the mean width of the trapped states. Also the decay
+rates saturate as a function of the coupling strength. The mechanism of the
+saturation is studied in detail. In any case, the critical region of
+reorganization is enlarged. When the transmission coefficients for the
+different channels are different, the width distribution is broadened as
+compared to a chi_K^2 distribution where K is the number of channels. Resonance
+trapping takes place before the broad state overlaps regions beyond the
+extension of the spectrum of the closed system.",9805029v1
+1999-07-20,Saturation from nuclear pion dynamics,"We construct an equation-of-state for nuclear matter based on the chiral
+Lagrangian. The relevant scales are discussed and an effective chiral power
+expansion scheme, which is constructed to work around the nuclear saturation
+density, is presented. A realistic equation-of-state is obtained by adjusting
+one free parameter, when the leading and subleading terms in the expansion are
+included. The saturation mechanism is due to correlations induced by the
+one-pion-exchange interaction. Furthermore, we find a substantial deviation
+from the Fermi-gas estimate of the quark condensate in nuclear matter already
+at the saturation density.",9907078v2
+2001-08-13,Nuclear equation of state and spectral functions,"An overview is given of the theoretical work on nucleon spectral functions in
+finite nuclei. The consequences of the observed spectral strength distribution
+are then considered in the context of the nuclear-matter saturation problem.
+Arguments are presented suggesting that short-range correlations are mainly
+responsible for the actual value of the observed charge density in 208Pb and by
+extension for the empirical value of the saturation density of nuclear matter.
+This observation combined with the general understanding of the spectroscopic
+strength suggests that a renewed study of nuclear matter, emphasizing the
+self-consistent determination of the spectral strength due to short-range and
+tensor correlations, may shed light on the perennial nuclear saturation
+problem. First results using such a scheme are presented. Arguments are
+discussed that clarify the role of long-range correlations and their relevance
+for nuclear saturation.",0108030v1
+2002-04-12,Saturation of nuclear matter and radii of unstable nuclei,"We examine relations among the parameters characterizing the phenomenological
+equation of state (EOS) of nearly symmetric, uniform nuclear matter near the
+saturation density by comparing macroscopic calculations of radii and masses of
+stable nuclei with the experimental data. The EOS parameters of interest here
+are the symmetry energy S_0, the symmetry energy density-derivative coefficient
+L and the incompressibility K_0 at the normal nuclear density. We find a
+constraint on the relation between K_0 and L from the empirically allowed
+values of the slope of the saturation line (the line joining the saturation
+points of nuclear matter at finite neutron excess), together with a strong
+correlation between S_0 and L. In the light of the uncertainties in the values
+of K_0 and L, we macroscopically calculate radii of unstable nuclei as expected
+to be produced in future facilities. We find that the matter radii depend
+strongly on L while being almost independent of K_0, a feature that will help
+to determine the L value via systematic measurements of nuclear size.",0204033v1
+2005-07-04,Non-locality in the nucleon-nucleon interaction and nuclear matter saturation,"We study the possible relationship between the saturation properties of
+nuclear matter and the inclusion of non-locality in the nucleon-nucleon
+interaction. To this purpose we compute the saturation curve of nuclear matter
+within the Bethe-Brueckner-Goldstone theory using a recently proposed realistic
+non-local potential, and compare it with the corresponding curves obtained with
+a purely local realistic interaction (Argonne v$_{18}$) and the most recent
+version of the one-boson exchange potential (CD Bonn). We find that the
+inclusion of non-locality in the two-nucleon bare interaction strongly affects
+saturation, but it is unable to provide a consistent description of few-body
+nuclear systems and nuclear matter.",0507009v2
+2006-09-11,Universality of the saturation scale and the initial eccentricity in heavy ion collisions,"Recent estimates that Color Glass Condensate initial conditions may generate
+a larger initial eccentricity for noncentral relativistic heavy ion collisions
+(relative to the initial eccentricity assumed in earlier hydrodynamic
+calculations) have raised the possibility of a higher bound on the viscosity of
+the Quark Gluon Plasma. We show that this large initial eccentricity results in
+part from a definition of the saturation scale as proportional to the number of
+nucleons participating in the collision. A saturation scale proportional to the
+nuclear thickness function (and therefore independent of the probe) leads to a
+smaller eccentricity, albeit still larger than the value used in hydrodynamic
+models. Our results suggest that the early elliptic flow in heavy ion
+collisions (unlike multiplicity distributions) is sensitive to the universality
+of the saturation scale in high energy QCD.",0609021v1
+2004-10-19,A novel approach for the temperature dependency of saturated signal power in EDFAs,"The temperature dependency of the saturated signal power for the transition
+in erbium-doped fiber amplifiers (EDFAs) pumped at 980 nm and 1480 nm pump
+wavelengths within a temperature range from 20 to 60 oC are investigated by a
+novel approach. For 1480 nm pumping regime, it is seen that the saturated
+signal power increases more quickly than that of 980 nm pumping regime, with
+the increasing temperature. The variation in the saturated signal power with
+temperature is nearly constant at 980 nm pumping regime. In addition, the
+population inversion with respect to the increasing normalized signal power is
+examined and it is seen that it is independent of temperature for 980 nm but it
+strongly depends on temperature for 1480 nm especially at lower normalized
+signal powers.",0410132v2
+2005-07-28,X-point collapse and saturation in the nonlinear tearing mode reconnection,"We study the nonlinear evolution of the resistive tearing mode in slab
+geometry in two dimensions. We show that, in the strongly driven regime (large
+Delta'), a collapse of the X-point occurs once the island width exceeds a
+certain critical value ~1/Delta'. A current sheet is formed and the
+reconnection is exponential in time with a growth rate ~eta^1/2, where eta is
+the resistivity. If the aspect ratio of the current sheet is sufficiently
+large, the sheet can itself become tearing-mode unstable, giving rise to
+secondary islands, which then coalesce with the original island. The saturated
+state depends on the value of Delta'. For small Delta', the saturation
+amplitude is ~Delta' and quantitatively agrees with the theoretical prediction.
+If Delta' is large enough for the X-point collapse to have occured, the
+saturation amplitude increases noticeably and becomes independent of Delta'.",0507206v1
+2007-05-13,Gluon saturation and the Froissart bound: a simple approach,"At very high energies we expect that the hadronic cross sections satisfy the
+Froissart bound, which is a well-established property of the strong
+interactions. In this energy regime we also expect the formation of the Color
+Glass Condensate, characterized by gluon saturation and a typical momentum
+scale: the saturation scale $Q_s$. In this paper we show that if a saturation
+window exists between the nonperturbative and perturbative regimes of Quantum
+Chromodynamics (QCD), the total cross sections satisfy the Froissart bound.
+Furthermore, we show that our approach allows us to describe the high energy
+experimental data on $pp/p\bar{p}$ total cross sections.",0705.1842v2
+2007-05-24,Saturation QCD predictions with heavy quarks at HERA,"The measurement of the proton structure function at HERA is often seen as a
+hint for the observation of saturation in high-energy QCD e.g. through the
+observation of geometric scaling. Accordingly, the dipole picture provides a
+powerful framework in which the QCD-based saturation models can be confronted
+to the data. In this paper, we give a parametrisation of proton structure
+function which is directly constrained by the dynamics of QCD in its
+high-energy limit and fully includes the heavy quark effects. We obtain a good
+agreement with the available data. Furthermore, to the contrary of various
+models in the literature, we do not observe a significant decrease of the
+saturation momentum due to the heavy quark inclusion.",0705.3672v1
+2007-06-06,Saturation effects in the sub-Doppler spectroscopy of Cesium vapor confined in an Extremely Thin Cell,"Saturation effects affecting absorption and fluorescence spectra of an atomic
+vapor confined in an Extremely Thin Cell (cell thickness $L < 1 \mu m$) are
+investigated experimentally and theoretically. The study is performed on the
+$D_{2}$ line ($\lambda ~= ~852 nm)$ of $Cs$ and concentrates on the two
+situations $L = \lambda /2$ and $L =\lambda$, the most contrasted ones with
+respect to the length dependence of the coherent Dicke narrowing. For $L =
+\lambda /2$, the Dicke-narrowed absorption profile simply broadens and
+saturates in amplitude when increasing the light intensity, while for $L
+=\lambda$, sub-Doppler dips of reduced absorption at line-center appear on the
+broad absorption profile. For a fluorescence detection at $L =\lambda$,
+saturation induces narrow dips, but only for hyperfine components undergoing a
+population loss through optical pumping. These experimental results are
+interpreted with the help of the various existing models, and are compared with
+numerical calculations based upon a two-level modelling that considers both a
+closed and an open system.",0706.0837v1
+2007-10-30,AgInSe2 Nanorods: A semiconducting material for saturable absorber,"AgInSe2 nanorods (NRs) with diameter of 15 nm have been investigated for
+their nonlinear optical responses by using Z-scan and transient absorption
+techniques with femtosecond laser pulses of photon energy greater than the
+bandgap. At excitation irradiance of 20 GW/cm2, AgInSe2 NRs reveal saturation
+in the nonlinear absorption and optical Kerr nonlinearity with a recovery time
+determined to be a few ten picoseconds. Such large saturable absorption and
+Kerr nonlinearity exhibit a third-order susceptibility of 1.2 x 10-8 esu and a
+figure of merit of 0.04 esu.cm.s-1, making AgInSe2 NRs a promising candidate
+for saturable absorption devices.",0710.5573v1
+2007-12-20,Lie algebra F-normalisers are intravariant,"Let F be a saturated formation of soluble Lie algebras and let U be an
+F-normaliser of the soluble Lie algebra L. Then U is intravariant in L.",0712.3306v1
+2008-01-03,Observation of coherence revival and fidelity saturation in a delta-kicked rotor potential,"We experimentally investigate the effect of atomic $\delta$-kicked rotor
+potentials on the mutual coherence between wavepackets in an atom
+interferometer. The differential action of the kicked rotor degrades the mutual
+coherence, leading to a reduction of the interferometry fringe visibility;
+however, when the repetition rate of the kicked rotor is at or near the quantum
+resonance, we observe revival of matter-wave coherence as the number of kicks
+increases, resulting in non-vanishing coherence in the large kick number limit.
+This coherence saturation effect reflects a saturation of fidelity decay due to
+momentum displacements in deep quantum regime. The saturation effect is
+accompanied with an invariant distribution of matter-wave coherence under the
+kicked rotor perturbations.",0801.0475v3
+2008-02-12,Resummation of projectile-target multiple scatterings and parton saturation,"In the framework of a toy model which possesses the main features of QCD in
+the high energy limit, we conduct a numerical study of scattering amplitudes
+constructed from parton splittings and projectile-target multiple interactions,
+in a way that unitarizes the amplitudes without however explicit saturation in
+the wavefunction of the incoming states. This calculation is performed in two
+different ways. One of these formulations, the closest to field theory,
+involves the numerical resummation of a factorially divergent series, for which
+we develop appropriate numerical tools. We accurately compare the properties of
+the resulting amplitudes with what would be expected if saturation were
+explicitly included in the evolution of the states. We observe that the
+amplitudes have similar properties in a small but finite range of rapidity in
+the beginning of the evolution, as expected. Some of the features of
+reaction-diffusion processes are already present in that range, even when
+saturation is left out of the model.",0802.1656v1
+2008-04-09,Saturation in Deep Inelastic Scattering from AdS/CFT,"We analyze deep inelastic scattering at small Bjorken x, using the
+approximate conformal invariance of QCD at high energies. Hard pomeron
+exchanges are resummed eikonally, restoring unitarity at large values of the
+phase shift in the dual AdS geometry. At weak coupling this phase is imaginary,
+corresponding to a black disk in AdS. In this saturated regime, cross sections
+exhibit geometric scaling and have a simple universal form, which we test
+against available experimental data for the proton structure function
+F_2(x,Q^2). We predict, in particular, the dependence of the cross section on
+the scaling variable (Q/Q_s)^2 in the deeply saturated region, where Q_s is the
+usual saturation scale. We find agreement with current data on F_2 in the
+kinematical region 0.5 < Q^2 < 10 GeV^2, x < 10^-2, with an average 6%
+accuracy. We conclude by discussing the relation of our approach with the
+commonly used dipole formalism.",0804.1562v3
+2008-04-20,Nonlinear Photoluminescence Excitation Spectroscopy of Carbon Nanotubes: Exploring the Upper Density Limit of One-Dimensional Excitons,"We have studied emission properties of high-density excitons in single-walled
+carbon nanotubes through nonlinear photoluminescence excitation spectroscopy.
+As the excitation intensity was increased, all emission peaks arising from
+different chiralities showed clear saturation in intensity. Each peak exhibited
+a saturation value that was independent of the excitation wavelength,
+indicating that there is an upper limit on the exciton density for each
+nanotube species. We developed a theoretical model based on exciton diffusion
+and exciton-exciton annihilation that successfully reproduced the saturation
+behavior, allowing us to estimate exciton densities. These estimated densities
+were found to be still substantially smaller than the expected Mott density
+even in the saturation regime, in contrast to conventional semiconductor
+quantum wires.",0804.3190v1
+2008-06-18,Analytic pro-p groups of small dimensions,"According to Lazard, every p-adic Lie group contains an open pro-p subgroup
+which is saturable. This can be regarded as the starting point of p-adic Lie
+theory, as one can naturally associate to every saturable pro-p group G a Lie
+lattice L(G) over the p-adic integers.
+  Essential features of saturable pro-p groups include that they are
+torsion-free and p-adic analytic. In the present paper we prove a converse
+result in small dimensions: every torsion-free p-adic analytic pro-p group of
+dimension less than p is saturable.
+  This leads to useful consequences and interesting questions. For instance, we
+give an effective classification of 3-dimensional soluble torsion-free p-adic
+analytic pro-p groups for p > 3. Our approach via Lie theory is comparable with
+the use of Lazard's correspondence in the classification of finite p-groups of
+small order.",0806.2968v1
+2008-09-05,New properties of z-scaling: flavor independence and saturation at low z,"Experimental data on inclusive cross sections of particles produced in high
+energy proton-(anti)proton collisions at ISR, RHIC, and Tevatron are analyzed
+in the framework of $z$-scaling. New features of the scaling function $\psi(z)$
+are established. These are flavor independence of $\psi(z)$ including particles
+with heavy flavor content and saturation at low $z$. The flavor independence
+means that the shape of the scaling function $\psi(z)$ is the same for
+different hadron species. The saturation corresponds to flattening of $\psi(z)$
+for $z<0.1$. Relations of model parameters used in data $z$-presentation with
+some thermodynamical quantities (entropy, specific heat, temperature) are
+discussed. It is shown that behavior of the particle spectra at low $z$ is
+controlled by a parameter $c$ interpreted as a specific heat of the created
+medium associated with production of the inclusive particle. The saturation
+regime of $\psi(z)$ observed at low $z$ is assumed to be preferable in
+searching for phase transitions of hadron matter and for study of
+non-perturbative QCD in high energy proton-(anti)proton collisions at U70,
+RHIC, Tevatron, and LHC.",0809.1033v1
+2008-10-08,Saturation of Two Level Systems and Charge Noise in Josephson Junction Qubits,"We study the charge noise $S_Q$ in Josephson qubits produced by fluctuating
+two level systems (TLS) with electric dipole moments in the substrate. The TLS
+are driven by an alternating electric field of angular frequency $\Omega$ and
+electric field intensity $I$. It is not widely appreciated that TLS in small
+qubits can easily be strongly saturated if $I\gg I_c$, where $I_c$ is the
+critical electric field intensity. To investigate the effect of saturation on
+the charge noise, we express the noise spectral density in terms of density
+matrix elements. To determine the dependence of the density matrix elements on
+the ratio $I/I_c$, we find the steady state solution for the density matrix
+using the Bloch-Redfield differential equations. We then obtain an expression
+for the spectral density of charge fluctuations as a function of frequency $f$
+and the ratio $I/I_c$. We find $1/f$ charge noise at low frequencies, and that
+the charge noise is white (constant) at high frequencies. Using a flat density
+of states, we find that TLS saturation has no effect on the charge noise at
+either high or low frequencies.",0810.1334v2
+2008-12-11,Mixed scenario of the charged liquid surface reconstruction,"Discussed in the paper is a mixed scenario of the charged liquid surface
+reconstruction in the situation where the 2D surface charge density is close to
+its saturation value.",0812.2157v1
+2009-02-11,Asymptotic behavior of two-phase flows in heterogeneous porous media for capillarity depending only on space. I. Convergence to the optimal entropy solution,"We consider an immiscible two-phase flow in a heterogeneous one-dimensional
+porous medium. We suppose particularly that the capillary pressure field is
+discontinuous with respect to the space variable. The dependence of the
+capillary pressure with respect to the oil saturation is supposed to be weak,
+at least for saturations which are not too close to 0 or 1. We study the
+asymptotic behavior when the capillary pressure tends to a function which does
+not depend on the saturation. In this paper, we show that if the capillary
+forces at the spacial discontinuities are oriented in the same direction that
+the gravity forces, or if the two phases move in the same direction, then the
+saturation profile with capillary diffusion converges toward the unique optimal
+entropy solution to the hyperbolic scalar conservation law with discontinuous
+flux functions.",0902.1877v3
+2009-06-15,CCFM Evolution with Unitarity Corrections,"We considerably extend our previous analysis of the implementation of an
+absorptive boundary condition, which mimics saturation effects, on the linear
+CCFM evolution. We present detailed results for the evolution of the
+unintegrated gluon density in the presence of saturation and extract the energy
+dependence of the emerging saturation momentum. We show that CCFM and BFKL
+evolution lead to almost identical predictions after including the effects of
+gluon saturation and of the running of the coupling. We moreover elucidate
+several important and subtle aspects of the CCFM formalism, such as its
+relation to BFKL, the structure of the angular ordered cascade, and the
+derivation of more inclusive versions of CCFM. We also propose non--leading
+modifications of the standard CCFM evolution which may play an important role
+for phenomenological studies.",0906.2683v2
+2009-07-30,Baryon stopping and saturation physics in relativistic collisions,"We investigate baryon transport in relativistic heavy-ion collisions at
+energies reached at the CERN Super Proton Synchrotron, BNL Relativistic
+Heavy-Ion Collider (RHIC), and CERN LHC in the model of saturation. An
+analytical scaling law is derived within the color glass condensate framework
+based on small-coupling QCD. Transverse momentum spectra, net-baryon rapidity
+distributions and their energy, mass and centrality dependences are well
+described. In a comparison with RHIC data in Au + Au collisions at sqrt (s_NN)
+= 62.4 GeV and 200 GeV, the gradual approach to the gluon saturation regime is
+investigated, and limits for the saturation-scale exponent are determined.
+Predictions for net-baryon rapidity spectra and the mean rapidity loss in
+central Pb + Pb collisions at LHC energies of sqrt (s_NN) = 5.52 TeV are made.",0907.5444v2
+2009-10-30,Atomic layer graphene as saturable absorber for ultrafast pulsed lasers,"The optical conductance of monolayer graphene is defined solely by the fine
+structure constant. The absorbance has been predicted to be independent of
+frequency. In principle, the interband optical absorption in zero-gap graphene
+could be saturated readily under strong excitation due to Pauli blocking. Here,
+we demonstrate the use of atomic layer graphene as saturable absorber in a
+mode-locked fiber laser for the generation of ultrashort soliton pulses (756
+fs) at the telecommunication band. The modulation depth can be tuned in a wide
+range from 66.5% to 6.2% by varying the thickness of graphene. Our results
+suggest that ultrathin graphene films are potentially useful as optical
+elements in fiber lasers. Graphene as a laser mode locker can have many merits
+such as lower saturation intensity, ultrafast recovery time, tunable modulation
+depth and wideband tuneability.",0910.5820v1
+2010-01-07,Numerical modelling of unsaturated-saturated flow under centrifugation with no outflow,"A novel centrifuge set-up for the study of unsaturated flow characteristics
+in porous media is examined. In this set-up, simple boundary conditions can be
+used, but a free moving boundary between unsaturated-saturated flow arises. A
+precise and numerically efficient approximation is presented for the
+mathematical model based on Richards' nonlinear and degenerate equation
+expressed in terms of effective saturation using the Van Genuchten-Mualem
+ansatz for the soil parameters in the unsaturated zone. Sensitivity of the
+measurable quantities (rotational moment, center of gravity and time period to
+achieve quasi steady state) on the soil parameters is investigated in several
+numerical experiments. They show that the set-up is suitable for the
+determination of the soil parameters via the solution of an inverse problem in
+an iterative way, excluding the saturated hydraulic conductivity. For this
+parameter, an existing simple centrifuge set-up is repeated and augmented with
+transient measurements.",1001.1070v1
+2010-02-24,Correlations in impact-parameter space in a hierarchical saturation model for QCD at high energy,"In order to get an estimate of the homogeneity of the distribution of matter
+in a fast hadron or nucleus, we compute the correlations of the saturation
+scales Q_s between different points in impact-parameter space, in some specific
+saturation models. We find that these correlations are quite strong: The
+saturation scale is nearly uniform in domains whose sizes scale like
+exp[const*ln^2(1/\alpha_s^2)]/Q_s, which means that the density of gluons
+should not fluctuate significantly over regions of that typical size. We expect
+these conclusions as well as the explicit analytical expressions we obtain for
+the correlations to be true also for full QCD in appropriate limits.",1002.4575v1
+2010-03-09,On saturation of charged hadron production in pp collisions at LHC,"First results on charged hadron transverse momentum spectra in pp collisions
+obtained by the CMS Collaboration at LHC were analyzed in z-scaling approach.
+The first LHC data confirm z-scaling. The saturation regime of the scaling
+function psi(z) observed in pp and antp-pp interactions at lower energy sqrt s
+= 19-1960 GeV is verified. The saturation of psi(z) for charged hadrons is
+found down to z=0.05 at the highest energy sqrt s = 2360 GeV reached till now
+at colliders. A microscopic scenario of hadron production is discussed in
+connection with search for new signatures of phase transitions in hadron
+matter. Constituent energy loss and its dependencies on the transverse momentum
+of charged hadrons and collision energy are estimated. The beam energy scan at
+LHC in the saturation region is suggested.",1003.1913v1
+2010-03-15,Saturating the holographic entropy bound,"The covariant entropy bound states that the entropy, S, of matter on a
+light-sheet cannot exceed a quarter of its initial area, A, in Planck units.
+The gravitational entropy of black holes saturates this inequality. The entropy
+of matter systems, however, falls short of saturating the bound in known
+examples. This puzzling gap has led to speculation that a much stronger bound,
+S< A^{3/4}, may hold true. In this note, we exhibit light-sheets whose entropy
+exceeds A^{3/4} by arbitrarily large factors. In open FRW universes, such
+light-sheets contain the entropy visible in the sky; in the limit of early
+curvature domination, the covariant bound can be saturated but not violated. As
+a corollary, we find that the maximum observable matter and radiation entropy
+in universes with positive (negative) cosmological constant is of order
+Lambda^{-1} (Lambda^{-2}), and not |Lambda|^{-3/4} as had hitherto been
+believed. Our results strengthen the evidence for the covariant entropy bound,
+while showing that the stronger bound S< A^{3/4} is not universally valid. We
+conjecture that the stronger bound does hold for static, weakly gravitating
+systems.",1003.3012v1
+2010-06-02,Correlations in impact-parameter space in saturation models,"In order to get an estimate of the homogeneity of the distribution of matter
+in a fast hadron, we compute the correlation of the saturation scales between
+different impact parameters. We find that these correlations are quite strong:
+The saturation scale is nearly uniform in a wide domain around each point in
+impact-parameter space. We provide analytical expressions for the correlations,
+which are supported by numerical simulations. Although the numerical
+calculations are done for specific saturation models which are obtained from
+QCD after drastic simplifications, we expect our analytical formulas to be
+correct for full QCD in asymptotic limits, since their derivation requires only
+a few general assumptions.",1006.0425v1
+2010-07-12,Mutual boosting of the saturation scales in colliding nuclei,"Saturation of small-x gluons in a nucleus, which has the form of transverse
+momentum broadening of projectile gluons in pA collisions in the nuclear rest
+frame, leads to a modification of the parton distribution functions in the beam
+compared with pp collisions. The DGLAP driven gluon distribution turns out to
+be suppressed at large x, but significantly enhanced at x<<1. This is a high
+twist effect. In the case of nucleus-nucleus collisions all participating
+nucleons on both sides get enriched in gluon density at small x, which leads to
+a further boosting of the saturation scale. We derive reciprocity equations for
+the saturation scales corresponding to a collision of two nuclei. The solution
+of these equations for central collisions of two heavy nuclei demonstrate a
+significant, up to several times, enhancement of Q_{sA}^2, in AA compared with
+pA collisions.",1007.1913v2
+2010-07-14,Monolayer Graphene as Saturable Absorber in Mode-locked Laser,"We demonstrate that the intrinsic properties of monolayer graphene allow it
+to act as a more effective saturable absorber for mode-locking fiber lasers
+compared to multilayer graphene. The absorption of monolayer graphene can be
+saturated at lower excitation intensity compared to multilayer graphene,
+graphene with wrinkle-like defects, and functionalized graphene. Monolayer
+graphene has a remarkable large modulation depth of 95.3%, whereas the
+modulation depth of multilayer graphene is greatly reduced due to nonsaturable
+absorption and scattering loss. Picoseconds ultrafast laser pulse (1.23 ps) can
+be generated using monolayer graphene as saturable absorber. Due to the
+ultrafast relaxation time, larger modulation depth and lower scattering loss of
+monolayer graphene, it performs better than multilayer graphene in terms of
+pulse shaping ability, pulse stability and output energy.",1007.2243v2
+2010-11-12,Piezoresistance in silicon at uniaxial compressive stresses up to 3 GPa,"The room-temperature longitudinal piezoresistance of n-type and p-type
+crystalline silicon along selected crystal axes is investigated under uniaxial
+compressive stresses up to 3 GPa. While the conductance ($G$) of n-type silicon
+eventually saturates at $\approx 45%$ of its zero-stress value ($G_0$) in
+accordance with the charge transfer model, in p-type material $G/G_0$ increases
+above a predicted limit of $\approx 4.5$ without any significant saturation,
+even at 3 GPa. Calculation of $G/G_0$ using \textit{ab-initio} density
+functional theory reveals that neither $G$ nor the mobility, when properly
+averaged over the hole distribution, saturate at stresses lower than 3 GPa. The
+lack of saturation has important consequences for strained silicon
+technologies.",1011.3008v3
+2010-12-21,Non-linear viscous saturation of r-modes,"Pulsar spin frequencies and their time evolution are an important source of
+information on compact stars and their internal composition. Oscillations of
+the star can reduce the rotational energy via the emission of gravitational
+waves. In particular unstable oscillation modes, like r-modes, are relevant
+since their amplitude becomes large and can lead to a fast spin-down of young
+stars if they are saturated by a non-linear saturation mechanism. We present a
+novel mechanism based on the pronounced large-amplitude enhancement of the bulk
+viscosity of dense matter. We show that the enhanced damping due to non-linear
+bulk viscosity can saturate r-modes of neutron stars at amplitudes appropriate
+for an efficient spin-down.",1012.4834v2
+2011-03-18,Gluon saturation and entropy production in proton proton collisions,"We study properties of high energy factorisable gluon densities focusing on
+saturation effects. In particular we show that the property of saturation of
+unintegrated gluon density allows for introduction of thermodynamical entropy
+associated with production of gluons. This is due to the observation that
+saturation scale acts like a mass of a gluon which related with temperature via
+thermodynamical relations allows for calculations of entropy. We also show that
+obtained entropy behaves like multiplicity of produced gluons.",1103.3654v4
+2011-04-19,Energy dependence of the saturation scale and the charged multiplicity in pp and AA collisions,"A natural framework to understand the energy dependence of bulk observables
+from lower energy experiments to the LHC is provided by the Color Glass
+Condensate, which leads to a ""geometrical scaling"" in terms of an energy
+dependent saturation scale Q_s. The measured charged multiplicity, however,
+seems to grow faster (~\sqrt{s}^0.3) in nucleus-nucleus collisions than it does
+for protons (~\sqrt{s}^0.2), violating the expectation from geometric scaling.
+We argue that this difference between pp and AA collisions can be understood
+from the effect of DGLAP evolution on the value of the saturation scale, and is
+consistent with gluon saturation observations at HERA.",1104.3725v2
+2011-04-22,A natural model of the multiverse axioms,"If ZFC is consistent, then the collection of countable computably saturated
+models of ZFC satisfies all of the Multiverse Axioms introduced by Hamkins.",1104.4450v1
+2011-08-12,A Minimax Linear Quadratic Gaussian Method for Antiwindup Control Synthesis,"In this paper, a dynamic antiwindup compensator design is proposed which
+augments the main controller and guarantees robust performance in the event of
+input saturation. This is a two stage process in which first a robust optimal
+controller is designed for an uncertain linear system which guarantees the
+internal stability of the closed loop system and provides robust performance in
+the absence of input saturation. Then a minimax linear quadratic Gaussian (LQG)
+compensator is designed to guarantee the performance in certain domain of
+attraction, in the presence of input saturation. This antiwindup augmentation
+only comes into action when plant is subject to input saturation. In order to
+illustrate the effectiveness of this approach, the proposed method is applied
+to a tracking control problem for an air-breathing hypersonic flight vehicle
+(AHFV).",1108.2568v1
+2011-10-05,Boosted saturation bound in colliding nuclei,"Interaction with a nucleus in pA collisions enhances the higher Fock
+components in the projectile proton. Effectively, this corresponds to an
+increase of the hard scale of the process by the saturation momentum Q^2 ->
+Q^2+Q_{sA}^2, which leads to an increased gluon distribution function at small
+x (but suppressed at x -> 1) compared to that in pp collisions. In the case of
+AA collisions the gluon distributions of bound nucleons in both nuclei turn out
+to be enhanced, i.e. to be boosted to higher saturation scales compared to pA
+collisions. A set of bootstrap equations relating the saturation scales in the
+colliding nuclei is derived and solved. The boosting effect has a moderate
+magnitude at the energies of RHIC, but becomes significant at LHC.",1110.0964v1
+2011-10-25,Growth saturation of unstable thin films on transverse-striped hydrophilic-hydrophobic micropatterns,"Using three-dimensional numerical simulations, we demonstrate the growth
+saturation of an unstable thin liquid film on micropatterned
+hydrophilic-hydrophobic substrates. We consider different transverse-striped
+micropatterns, characterized by the total fraction of hydrophilic coverage and
+the width of the hydrophilic stripes. We compare the growth of the film on the
+micropatterns to the steady states observed on homogeneous substrates, which
+correspond to a saturated sawtooth and growing finger configurations for
+hydrophilic and hydrophobic substrates, respectively. The proposed
+micropatterns trigger an alternating fingering-spreading dynamics of the film,
+which leads to a complete suppression of the contact line growth above a
+critical fraction of hydrophilic stripes. Furthermore, we find that increasing
+the width of the hydrophilic stripes slows down the advancing front, giving
+smaller critical fractions the wider the hydrophilic stripes are. Using
+analytical approximations, we quantitatively predict the growth rate of the
+contact line as a function of the covering fraction, and predict the threshold
+fraction for saturation as a function of the stripe width.",1110.5496v1
+2011-12-08,Induced Saturation Number,"In this paper, we discuss a generalization of the notion of saturation in
+graphs in order to deal with induced structures. In particular, we define ${\rm
+indsat}(n,H)$, which is the fewest number of gray edges in a trigraph so that
+no realization of that trigraph has an induced copy of $H$, but changing any
+white or black edge to gray results in some realization that does have an
+induced copy of $H$.
+  We give some general and basic results and then prove that ${\rm
+indsat}(n,P_4)=\lceil (n+1)/3\rceil$ for $n\geq 4$ where $P_4$ is the path on 4
+vertices. We also show how induced saturation in this setting extends to a
+natural notion of saturation in the context of general Boolean formulas.",1112.1923v2
+2012-04-02,Constraining the nuclear equation of state at subsaturation densities,"Only one third of the nucleons in $^{208}$Pb occupy the saturation density
+area. Consequently nuclear observables related to average properties of nuclei,
+such as masses or radii, constrain the equation of state (EOS) not at
+saturation density but rather around the so-called crossing density, localised
+close to the mean value of the density of nuclei: $\rho\simeq$0.11 fm$^{-3}$.
+This provides an explanation for the empirical fact that several EOS quantities
+calculated with various functionals cross at a density significantly lower than
+the saturation one. The third derivative M of the energy at the crossing
+density is constrained by the giant monopole resonance (GMR) measurements in an
+isotopic chain rather than the incompressibility at saturation density. The GMR
+measurements provide M=1110 $\pm$ 70 MeV (6% uncertainty), whose extrapolation
+gives K$_\infty$=230 $\pm$ 40 MeV (17% uncertainty).",1204.0399v3
+2012-06-05,Electric field induced saturation effects in photoassociation of a pair of heteronuclear atoms,"We theoretically study saturation effects induced by an external static
+electric field on photoassociation (PA) of a heteronuclear atom pair. A static
+electric field influences scattering wave-function of two heteronuclear atoms
+as described in [D. Chakraborty, J. Hazra and B. Deb, J. Phys. B. {\bf 44}
+095201 (2011)]. For certain values of electric field strengths there exist
+anisotropic resonances in ground state scattering leading to a large
+modification of scattering wave-function at short and intermediate separations
+where photoassociative Franck-Condon overlap is significant. Photoassociation
+rate as a function of collision energy shows a splitting near resonant electric
+field in the mili Kelvin energy regime. This splitting with a prominent dip
+occurs due to resonant enhancement of free-bound stimulated linewidth leading
+to saturation in free-bound transitions. We study electric field induced
+saturation effects on both one- and two-colour PA. Our results suggest that a
+static electric field may influence the formation of ground state polar
+molecules in two-colour PA.",1206.0859v1
+2012-06-28,Simulation of grains in a vibrated U-tube without interstitial fluid,"We present a computational study using Molecular Dynamics of the development
+of an accumulation of grains in one side of a two dimensional U-tube under
+vertical vibrations. Studying the evolution of the height difference between
+the centers of mass of the branches of the tube, we found that it reaches a
+saturation value after vibrating for some time. We obtain that this saturation
+value is the same if the simulation start with the arms leveled or with a large
+initial height difference. We explore the effect of the width of the tube, the
+density of the grains and the coefficient of restitution between the grains and
+the wall on the value of the saturation. We obtain a value of the width of the
+tube for which the saturation value reaches a maximum, and show that the
+transport of grains between arms is favored for low grain densities and high
+grain-wall restitution coefficient.",1206.6546v1
+2012-10-04,Graphene Oxide vs. Reduced Graphene Oxide as saturable absorbers for Er-doped passively mode-locked fiber laser,"In this work we demonstrate comprehensive studies on graphene oxide (GO) and
+reduced graphene oxide (rGO) based saturable absorbers (SA) for mode-locking of
+Er-doped fiber lasers. The paper describes the fabrication process of both
+saturable absorbers and detailed comparison of their parameters. Our results
+show, that there is no significant difference in the laser performance between
+the investigated SA. Both provided stable, mode-locked operation with sub-400
+fs soliton pulses and more than 9 nm optical bandwidth at 1560 nm center
+wavelength. It has been shown that GO might be successfully used as an
+efficient SA without the need of its reduction to rGO. Taking into account
+simpler manufacturing technology and the possibility of mass production, GO
+seems to be a good candidate as a cost-effective material for saturable
+absorbers for Er-doped fiber lasers.",1210.1469v1
+2013-01-18,Homogeneously Saturated Model for Development in Time of the Price of an Asset,"The time development of the price of a financial asset is considered by
+constructing and solving Langevin equations for a homogeneously saturated
+model, and for comparison, for a standard model and for a logistic model. The
+homogeneously saturated model uses coupled rate equations for the money supply
+and for the price of the asset, similar to the coupled rate equations for
+population inversion and power density in a simple model of a homogeneously
+broadened laser.
+  Predictions of the models are compared for random numbers drawn from a
+Student's t-distribution. It is known that daily returns of the DJIA and S&P
+500 indices are fat tailed and are described well by Student's t-distributions
+over the range of observed values. The homogeneously saturated model shows
+returns that are consistent with daily returns for the indices (in the range of
+-30% to +30%) whereas the standard model and the logistic model show returns
+that are far from consistent with observed daily returns for the indices.",1301.4519v1
+2013-02-28,Torque Saturation in Bipedal Robotic Walking through Control Lyapunov Function Based Quadratic Programs,"This paper presents a novel method for directly incorporating user-defined
+control input saturations into the calculation of a control Lyapunov function
+(CLF)-based walking controller for a biped robot. Previous work by the authors
+has demonstrated the effectiveness of CLF controllers for stabilizing periodic
+gaits for biped walkers, and the current work expands on those results by
+providing a more effective means for handling control saturations. The new
+approach, based on a convex optimization routine running at a 1 kHz control
+update rate, is useful not only for handling torque saturations but also for
+incorporating a whole family of user-defined constraints into the online
+computation of a CLF controller. The paper concludes with an experimental
+implementation of the main results on the bipedal robot MABEL.",1302.7314v1
+2013-04-07,Statistical Mechanics of a Discrete Schrödinger Equation with Saturable Nonlinearity,"We study the statistical mechanics of the one-dimensional discrete nonlinear
+Schr\""odinger (DNLS) equation with saturable nonlinearity. Our study represents
+an extension of earlier work [Phys. Rev. Lett. {\bf 84}, 3740 (2000)] regarding
+the statistical mechanics of the one-dimensional DNLS equation with a cubic
+nonlinearity. As in this earlier study we identify the spontaneous creation of
+localized excitations with a discontinuity in the partition function. The fact
+that this phenomenon is retained in the saturable DNLS is non-trivial, since in
+contrast to the cubic DNLS whose nonlinear character is enhanced as the
+excitation amplitude increases, the saturable DNLS in fact becomes increasingly
+linear as the excitation amplitude increases. We explore the nonlinear dynamics
+of this phenomenon by direct numerical simulations.",1304.2065v1
+2013-05-23,Half-Saturation Constants in Functional Responses,"Our aim is to provide an overview of half-saturation constants reported in
+literature and to explore their consistency with body size. In many ecological
+models, intake of nutrients by plants and consumption of food by animals is
+considered to be a hyperbolic function of the nutrient concentration and the
+food density, respectively. However, data on the concentration (or density) at
+which half of the maximum intake rate is reached are scarce, limiting the
+applicability of the computational models. The meta-analysis was conducted on
+literature published worldwide. Most studies focused on algae and
+invertebrates, whereas some included fish, birds and mammals. The
+half-saturation constants obtained were linked to body size using ordinary
+regression analysis. The observed trends were compared to those noted in
+reviews on other density parameters. Half-saturation constants for different
+clades range within one or two orders of magnitude. Although these constants
+are inherently variable, exploring allometric relationships across different
+taxa helps to improve consistent parameterization of ecological models.",1305.5533v1
+2013-06-01,A study of saturated tensor cone for symmetrizable Kac-Moody algebras,"Let $\fg$ be a symmetrizable Kac-Moody Lie algebra with the standard Cartan
+subalgebra $\fh$ and the Weyl group $W$. Let $P_+$ be the set of dominant
+integral weights. For $\lambda \in P_+$, let $L(\lambda)$ be the irreducible,
+integrable, highest weight representation of $\fg$ with highest weight
+$\lambda$. For a positive integer $s$, define the {\em saturated tensor
+semigroup} as \begin{align*} \Gamma_s:= \{(\lambda_1, \dots, \lambda_s,\mu)\in
+P_+^{s+1}: \exists\, N>1 \,\,\text{with}\,\, L(N\mu)\subset
+L(N\lambda_1)\otimes \dots \otimes L(N\lambda_s)\}. \end{align*} The aim of
+this paper is to begin a systematic study of $\Gamma_s$ in the infinite
+dimensional symmetrizable Kac-Moody case. In this paper, we produce a set of
+necessary inequalities satisfied by $\Gamma_s$. We further prove that any
+integer $d>0$ is a saturation factor for $A^{(1)}_1$ and 4 is a saturation
+factor for $A^{(2)}_2$.",1306.0073v1
+2013-06-07,Estimating Saturated Hydraulic Conductivity from Surface Ground-Penetrating Radar Monitoring of Infiltration,"In this study we used Hydrus-1D to simulate water infiltration from a ring
+infiltrometer. We generated water content profiles at each time step of
+infiltration, based on a particular value of the saturated hydraulic
+conductivity while knowing the other van Genuchten parameters. Water content
+profiles were converted to dielectric permittivity profiles using the Complex
+Refractive Index Method relation. We then used the GprMax suite of programs to
+generate radargrams and to follow the wetting front using arrival time of
+electromagnetic waves recorded by a Ground-Penetrating Radar (GPR).
+Theoretically, the depth of the inflection point of the water content profile
+simulated at any infiltration time step is related to the peak of the reflected
+amplitude recorded in the corresponding trace in the radargram. We used this
+relationship to invert the saturated hydraulic conductivity for constant and
+falling head infiltrations. We present our method on synthetic examples and on
+two experiments carried out on sand. We further discuss the possibility of
+estimating two other van Genuchten parameters, n and \alpha, in addition to the
+saturated hydraulic conductivity.",1306.1823v1
+2013-07-15,Towards the Test of Saturation Physics Beyond Leading Logarithm,"We present results from the first next-to-leading order (NLO) numerical
+analysis of forward hadron production in pA collisions in the small-x
+saturation formalism. Using parton distributions and fragmentation functions at
+NLO, as well as the dipole amplitude from the solution to the
+Balitsky-Kovchegov equation with running coupling, together with the NLO
+corrections to the hard coefficients, we obtain a good description of the
+available RHIC data in dAu collisions. We also comment on the results in the
+large p_T region beyond the saturation scale. Furthermore, we make predictions
+for forward hadron production in pPb collisions at the LHC. This analysis not
+only incorporates the important NLO corrections for all partonic channels, but
+also reduces the renormalization scale dependence and therefore helps to
+significantly reduce the theoretical uncertainties. It therefore provides a
+precise test of saturation physics beyond the leading logarithmic
+approximation.",1307.4057v1
+2013-07-30,Intrinsic Localized Modes in a Nonlinear Electrical Lattice with Saturable Nonlinearity,"This experimental study of driven intrinsic localized modes (ILMs) in an
+electronic circuit lattice with saturable nonlinearity follows the theoretical
+work of Hadzievski and coworkers. They proposed that a saturable nonlinearity
+could introduce transition points where localized excitations in nonintegrable
+lattices would move freely. In our experiments MOS capacitors provide the
+saturable nonlinearity in an electric lattice. Because of the soft nonlinearity
+driver locked, auto-resonance stationary ILMs are observed below the bottom of
+a linear frequency band of the lattice. With decreasing driver frequency the
+width of the ILM changes in a step-wise manner as does the softening of the
+barrier between site-centered and bond-centered ILM locations in agreement with
+theoretical expectations. However, the steps show hysteresis between up and
+down frequency scans and such hysteresis inhibits the free motion of ILMs.",1307.7801v1
+2013-10-14,Waves statistics for generalized one-dimensional Nonlinear Schrodinger Equation with saturated nonlinearity,"We measure spectra, spatial correlation functions and probability density
+functions (PDFs) for waves amplitudes for generalized one-dimensional nonlinear
+Schrodinger (NLS) equation of focusing type with saturated nonlinearity. All
+additional terms beyond the classical NLS equation are small. As initial
+conditions we use perturbed by weak noise modulationally unstable condensate.
+On the PDFs we observe power-law region for small and medium amplitudes
+followed by intermediate region and then Rayleigh far tail. Power-law region
+appears starting from some critical levels of average amplitude and coefficient
+related to saturated nonlinearity, and then becomes more pronounced with
+average amplitude and saturation coefficient. Correlation of phases becomes
+significant for large wave events and contributes about one order of magnitude
+to the frequencies of their occurrence. Waves statistics for the considered
+systems turns out to be exceptionally stable against additional stochastic
+forces.",1310.3618v2
+2014-01-10,Moist-entropic vertical adiabatic lapse rates: the standard cases and some lead towards inhomogeneous conditions,"This note is a companion of Marquet and Geleyn (2013, {arXiv:1401.2379
+[ao-ph]}), where adiabatic lapse rates $\Gamma_{ns}$ and $\Gamma_{sw}$ are
+derived for non-saturated ($\Gamma_{ns}$) or saturated ($\Gamma_{sw}$) parcel
+of moist-air. They are computed in terms of the vertical derivative of the
+moist-air entropy potential temperature $\theta_s$ defined in Marquet (2011,
+{arXiv:1401.1097 [ao-ph]}). The saturated value $\Gamma_{sw}$ is rewritten in
+this note so that a more compact formulation is obtained. The new formulation
+for $\Gamma_{sw}$ is expressed in term of a weighting factor $C$. This factor
+may represent the proportion of an air parcel being in saturated conditions.",1401.2383v2
+2014-02-23,On Saturated $k$-Sperner Systems,"Given a set $X$, a collection $\mathcal{F}\subseteq\mathcal{P}(X)$ is said to
+be $k$-Sperner if it does not contain a chain of length $k+1$ under set
+inclusion and it is saturated if it is maximal with respect to this property.
+Gerbner et al. conjectured that, if $|X|$ is sufficiently large with respect to
+$k$, then the minimum size of a saturated $k$-Sperner system
+$\mathcal{F}\subseteq\mathcal{P}(X)$ is $2^{k-1}$. We disprove this conjecture
+by showing that there exists $\varepsilon>0$ such that for every $k$ and $|X|
+\geq n_0(k)$ there exists a saturated $k$-Sperner system
+$\mathcal{F}\subseteq\mathcal{P}(X)$ with cardinality at most
+$2^{(1-\varepsilon)k}$.
+  A collection $\mathcal{F}\subseteq \mathcal{P}(X)$ is said to be an
+oversaturated $k$-Sperner system if, for every
+$S\in\mathcal{P}(X)\setminus\mathcal{F}$, $\mathcal{F}\cup\{S\}$ contains more
+chains of length $k+1$ than $\mathcal{F}$. Gerbner et al. proved that, if
+$|X|\geq k$, then the smallest such collection contains between $2^{k/2-1}$ and
+$O\left(\frac{\log{k}}{k}2^k\right)$ elements. We show that if $|X|\geq k^2+k$,
+then the lower bound is best possible, up to a polynomial factor.",1402.5646v2
+2014-02-25,On coalgebras with internal moves,"In the first part of the paper we recall the coalgebraic approach to handling
+the so-called invisible transitions that appear in different state-based
+systems semantics. We claim that these transitions are always part of the unit
+of a certain monad. Hence, coalgebras with internal moves are exactly
+coalgebras over a monadic type. The rest of the paper is devoted to supporting
+our claim by studying two important behavioural equivalences for state-based
+systems with internal moves, namely: weak bisimulation and trace semantics.
+  We continue our research on weak bisimulations for coalgebras over order
+enriched monads. The key notions used in this paper and proposed by us in our
+previous work are the notions of an order saturation monad and a saturator. A
+saturator operator can be intuitively understood as a reflexive, transitive
+closure operator. There are two approaches towards defining saturators for
+coalgebras with internal moves. Here, we give necessary conditions for them to
+yield the same notion of weak bisimulation.
+  Finally, we propose a definition of trace semantics for coalgebras with
+silent moves via a uniform fixed point operator. We compare strong and weak
+bisimilation together with trace semantics for coalgebras with internal steps.",1402.6281v1
+2014-03-10,Probing Gluon Saturation through Dihadron Correlations at an Electron-Ion Collider,"Two-particle azimuthal angle correlations have been proposed to be one of the
+most direct and sensitive probes to access the underlying gluon dynamics
+involved in hard scatterings. In anticipation of an Electron-Ion Collider
+(EIC), detailed studies of dihadron correlation measurements in electron-proton
+and electron-ion collisions at an EIC have been performed. The impact of such
+measurements on the understanding of the different gluon distribution
+functions, as a clean signature for gluon saturation and to constrain
+saturation models further, has been explored. It is shown that dihadron
+correlation measurements will be one of the key methods to probe gluon
+saturation phenomena at a future EIC.",1403.2413v3
+2014-03-27,Saturation of atomic transitions using sub-wavelength diameter tapered optical fibers in rubidium vapor,"We experimentally investigate ultralow-power saturation of the rubidium D2
+transitions using a tapered optical fiber (TOF) suspended in a warm Rb vapor. A
+direct comparison of power-dependent absorption measurements for the TOF system
+with those obtained in a standard free-space vapor cell system highlights the
+differences in saturation behavior for the two systems. The effects of
+hyperfine pumping in the TOF system are found to be minimized due to the short
+atomic transit times through the highly confined evanescent optical mode guided
+by the TOF. The TOF system data is well-fit by a relatively simple empirical
+absorption model that indicates nanoWatt-level saturation powers.",1403.7141v2
+2014-05-14,Convective overstability in accretion disks: 3D linear analysis and nonlinear saturation,"Recently, Klahr & Hubbard (2014) claimed that a hydrodynamical linear
+overstability exists in protoplanetary disks, powered by buoyancy in the
+presence of thermal relaxation. We analyse this claim, confirming it through
+rigorous compressible linear analysis. We model the system numerically,
+reproducing the linear growth rate for all cases studied. We also study the
+saturated properties of the overstability in the shearing box, finding that the
+saturated state produces finite amplitude fluctuations strong enough to trigger
+the subcritical baroclinic instability. Saturation leads to a fast burst of
+enstrophy in the box, and a large-scale vortex develops in the course of the
+next $\approx$100 orbits. The amount of angular momentum transport achieved is
+of the order of $\alpha \approx 10^{-3}$, as in compressible SBI models. For
+the first time, a self-sustained 3D vortex is produced from linear amplitude
+perturbation of a quiescent base state.",1405.3437v2
+2014-06-26,The saturation number for Cayley's cubic surface,"We investigate the density of rational points on Cayley's cubic surface whose
+coordinates have few prime factors. The key tools used are the circle method
+and universal torsors.",1406.6963v1
+2014-07-24,Diffractive photoproduction of vector mesons at the LHC,"We confront saturation-based results for diffractive $\psi(2s)$ and $\rho$
+production at HERA and $J/\psi$ photoproduction with all available data
+including recent ones from HERA, ALICE and LHCb, finding a good agreement. We
+show that the $t$-distribution of differential cross-section of photoproduction
+of vector mesons offers a unique opportunity to discriminate among saturation
+and non-saturation models. This is due to emergence of a pronounced dip (or
+multiple dips) in the $t$-distribution of diffractive photoproduction of vector
+mesons at relatively large, but potentially accessible $|t|$ that can be traced
+back to the unitarity features of colour dipole amplitude in the saturation
+regime. We provide various predictions for exclusive (photo)-production of
+different vector mesons including the ratio of $\psi(2s)/J/\psi$ at HERA, the
+LHC and at future colliders.",1407.6703v1
+2014-08-17,A model for strong interactions at high energy based on the CGC/saturation approach,"We present our first attempt to develop a model for soft interactions at high
+energy, based on the BFKL Pomeron and the CGC/saturation approach. We construct
+an eikonal-type model, whose opacity is determined by the exchange of the
+dressed BFKL Pomeron. The Green's function of the Pomeron is calculated in the
+framework of the CGC/saturation approach. Using five parameters we achieve a
+good description of the experimental data at high energies (
+$W\,\geq\,0.546\,TeV$). The model results in different behaviour for the single
+and double diffraction cross sections at high energies. The single diffraction
+cross section reaches a saturated value (about 10 mb) at high energies, while
+the double diffraction cross section continues growing slowly",1408.3811v3
+2014-09-23,Preconditioning the prior to overcome saturation in Bayesian inverse problems,"We study Bayesian inference in statistical linear inverse problems with
+Gaussian noise and priors in Hilbert space. We focus our interest on the
+posterior contraction rate in the small noise limit. Existing results suffer
+from a certain saturation phenomenon, when the data generating element is too
+smooth compared to the smoothness inherent in the prior. We show how to
+overcome this saturation in an empirical Bayesian framework by using a
+non-centered data-dependent prior. The center is obtained from a
+preconditioning regularization step, which provides us with additional
+information to be used in the Bayesian framework. We use general techniques
+known from regularization theory. To highlight the significance of the findings
+we provide several examples. In particular, our approach allows to obtain and,
+using preconditioning improve after saturation, minimax rates of contraction
+established in previous studies. We also establish minimax contraction rates in
+cases which have not been considered so far.",1409.6496v1
+2014-09-29,Saturation Number of Trees in the Hypercube,"A graph $H^{\prime}$ is $(H, G)$-saturated if it is $G$-free and the addition
+of any edge of $H$ not in $H^{\prime}$ creates a copy of $G$. The saturation
+number $sat(H, G)$ is the minimum number of edges in a $(H, G)$-saturated
+graph. We investigate bounds on the saturation number of trees $T$ in the
+$n$-dimensional hypercube $Q_n$. We first present a general lower bound on the
+saturation number based on the minimum degree of non-leaves. From there, we
+suggest two general methods for constructing $T$-saturated subgraphs of $Q_n$,
+and prove nontrivial upper bounds for specific types of trees, including paths,
+generalized stars, and certain caterpillars under a restriction on minimum
+degree with respect to diameter.",1409.7983v2
+2014-12-14,Dielectric anisotropy in polar solvents under external fields,"We investigate dielectric saturation and increment in polar liquids under
+external fields. We couple a previously introduced dipolar solvent model to a
+uniform electric field and derive the electrostatic kernel of interacting
+dipoles. This procedure allows an unambiguous definition of the liquid
+dielectric permittivity embodying non-linear dielectric response and
+correlation effects.We find that the presence of the external field results in
+a dielectric anisotropy characterized by a two-component dielectric
+permittivity tensor. The increase of the electric field amplifies the
+permittivity component parallel to the field direction, i.e. dielectric
+increment is observed along the field. However, the perpendicular component is
+lowered below the physiological permittivity, indicating dielectric saturation
+perpendicular to the field. By comparison with Molecular Dynamics simulations
+from the literature, we show that the mean-field level dielectric response
+theory underestimates dielectric saturation. The inclusion of dipolar
+correlations at the weak-coupling level intensify the mean-field level
+dielectric saturation and improves the agreement with simulation data at weak
+electric fields. The correlation-corrected theory predicts as well the presence
+of a metastable configuration corresponding to the antiparallel alignment of
+dipoles with the field. This prediction can be verified by solvent-explicit
+simulations where solvent molecules are expected to be trapped transiently in
+this metastable state.",1412.4425v2
+2015-01-07,CSMA/CA Bottleneck Remediation in Saturation Mode with New Backoff Strategy,"Many modern wireless networks integrate carrier sense mul-tiple
+access/collision avoidance (CSMA/CA) with exponential backoff as medium access
+control (MAC) technique. In order to decrease the MAC overhead and the
+collision probability, we propose in this paper a new backoff strategy leading
+to better saturation throughput and access de-lay performance comparing to the
+classical protocol. We investigate the CSMA/CA with RTS/CTS technique, and we
+show that our strategy reaches better saturation throughput and access delay
+especially in dense networks. This proposed strategy distributes users over all
+the backoff stages to solve the bottleneck problem present in the first backoff
+stage. Finally, we analyze our strategy and we compare it to the classical one
+modeled by Markov chain. Analytical and simulation results show the improvment
+in term of saturation throughput. Cumulative density func-tion (CDF) of the
+access delay illustrates the important gain obtained by the proposed strategy.",1501.01422v1
+2015-03-13,Discrete Element Method simulations of the saturation of aeolian sand transport,"The saturation length of aeolian sand transport ($L_s$), characterizing the
+distance needed by wind-blown sand to adapt to changes in the wind shear, is
+essential for accurate modeling of the morphodynamics of Earth's sandy
+landscapes and for explaining the formation and shape of sand dunes. In the
+last decade, it has become a widely-accepted hypothesis that $L_s$ is
+proportional to the characteristic distance needed by transported particles to
+reach the wind speed (the ``drag length''). Here we challenge this hypothesis.
+From extensive numerical Discrete Element Method simulations, we find that, for
+medium and strong winds, $L_s\propto V_s^2/g$, where $V_s$ is the saturated
+value of the average speed of sand particles traveling above the surface and
+$g$ the gravitational constant. We show that this proportionality is consistent
+with a recent analytical model, in which the drag length is just one of four
+similarly important length scales relevant for sand transport saturation.",1503.03946v1
+2015-03-25,Grain Scale Modeling of Arbitrary Fluid Saturation in Random Packings,"We propose a model for increasing liquid saturation in a granular packing
+which can account for liquid redistribution at saturation levels beyond the
+well-studied capillary bridge regime. The model is capable of resolving and
+combining capillary bridges, menisci and fully saturated pores to form local
+liquid clusters of any shape. They can exchange volume due to the local Laplace
+pressure gradient via a liquid film on the surfaces of grains. Local
+instabilities like Haines jumps trigger the discontinuous evolution of the
+liquid front. The applicability of the model is demonstrated and compared to
+benchmark experiments on the level of individual liquid structures as well as
+on larger systems.",1503.07470v1
+2015-03-26,Holographic Thermalization in Charged Dilaton Anti-de Sitter Spacetime,"We study holographic thermalization in spacetimes with a chemical potential
+and a non-trivial dilaton field. Three non-local observables are used to probe
+the whole process and investigate the effect of the ratio of the chemical
+potential over temperature $\chi$ and the dilaton-Maxwell coupling constant
+$\alpha$. It is found that the saturation time is not always a monotonically
+increasing function of $\chi$, the situation depends on $\alpha$. When $0
+\leq\alpha \leq 1$, larger $\chi$ yields longer saturation time, while for
+$\alpha>1$, the situation becomes more complex. More interesting, we found that
+although $\alpha$ indeed has influence on the whole thermalization process, it
+nearly does not affect the saturation time, which indicates the universality of
+the saturation time for the dual one-parameter field theories.",1503.07700v1
+2015-03-27,"Wideband saturable absorption in few-layer molybdenum diselenide (MoSe2) for Q-switching Yb-, Er- and Tm-doped fiber lasers","We fabricate a free-standing molybdenum diselenide (MoSe2) saturable absorber
+by embedding liquid-phase exfoliated few-layer MoSe2 flakes into a polymer
+film. The MoSe2-polymer composite is used to Q-switch fiber lasers based on
+ytterbium (Yb), erbium (Er) and thulium (Tm) gain fiber, producing trains of
+microsecond-duration pulses with kilohertz repetition rates at 1060 nm, 1566 nm
+and 1924 nm, respectively. Such operating wavelengths correspond to sub-bandgap
+saturable absorption in MoSe2, which is explained in the context of
+edge-states, building upon studies of other semiconducting transition metal
+dichalcogenide (TMD)-based saturable absorbers. Our work adds few-layer MoSe2
+to the growing catalog of TMDs with remarkable optical properties, which offer
+new opportunities for photonic devices.",1503.08003v2
+2015-03-30,Chains of saturated models in AECs,"We study when a union of saturated models is saturated in the framework of
+tame abstract elementary classes (AECs) with amalgamation. We prove:
+  $\mathbf{Theorem}$
+  If $K$ is a tame AEC with amalgamation satisfying a natural definition of
+superstability (which follows from categoricity in a high-enough cardinal),
+then for all high-enough $\lambda$:
+  * The union of an increasing chain of $\lambda$-saturated models is
+$\lambda$-saturated.
+  * There exists a type-full good $\lambda$-frame with underlying class the
+saturated models of size $\lambda$.
+  * There exists a unique limit model of size $\lambda$.
+  Our proofs use independence calculus and a generalization of averages to this
+non first-order context.",1503.08781v4
+2015-04-28,Black phosphorus as a new broadband saturable absorber for infrared passively Q-switched fiber lasers,"Black phosphorus (BP) with its enticing electric and optical properties is
+intensely researched in the field of optoelectronics. In this paper, Q-switched
+pulses at 1550 nm and 2 um wavelengths are obtained by inserting
+bulk-structured BP based saturable absorber (SA) into an erbium-doped fiber
+laser (EDFL) and an thulium/holmium-doped fiber laser (THDFL), respectively.
+The BP-SA was prepared by depositing powered BP material on to the flat side of
+a side-polished single mode fiber. Q-switched 1550 nm pulses with width tuned
+from 9.35 to 31 us were obtained for the EDFL. For the THDFL, over 100 nm
+wavelength range could be achieved from 1832 to 1935 nm by adjusting the pump
+power. To the best of our knowledge, these results demonstrated the broadband
+saturable absorption property of BP and for the first time verified that BP as
+a new two-dimensional material for applications in saturable absorption
+devices.",1504.07341v1
+2015-05-19,Implementing the exact kinematical constraint in the saturation formalism,"We revisit the issue of the large negative next-to-leading order (NLO) cross
+section for single inclusive hadron production in $pA$ collisions in the
+saturation formalism. By implementing the exact kinematical constraint in the
+modified dipole splitting functions, two additional positive NLO correction
+terms are obtained. In the asymptotic large $k_\perp$ limit, we analytically
+show that these two terms become as large as the negative NLO contributions
+found in our previous calculation. Furthermore, the numerical results
+demonstrate that the applicable regime of the saturation formalism can be
+extended to a larger $k_\perp$ window, where the exact matching between the
+saturation formalism (in the asymptotic $k_\perp$ regime) and the collinear
+factorization calculations will have to be performed separately. In addition,
+after significantly improving the numerical accuracy of the NLO correction, we
+obtain excellent agreement with the LHC and RHIC data for forward hadron
+productions.",1505.05183v2
+2015-07-12,"Yb- and Er-doped fiber laser Q-switched with an optically uniform, broadband WS2 saturable absorber","We demonstrate a ytterbium (Yb) and an erbium (Er)-doped fiber laser
+Q-switched by a solution processed, optically uniform, few-layer tungsten
+disulfide saturable absorber (WS2-SA). Nonlinear optical absorption of the
+WS2-SA in the sub-bandgap region, attributed to the edge-induced states, is
+characterized by 3.1% and 4.9% modulation depths with 1.38 and 3.83 MW/cm2
+saturation intensities at 1030 and 1558 nm, respectively. By integrating the
+optically uniform WS2-SA in the Yb- and Er-doped laser cavities, we obtain
+self-starting Q-switched pulses with microsecond duration and kilohertz
+repetition rates at 1030 and 1558 nm. Our work demonstrates broadband
+sub-bandgap saturable absorption of a single, solution processed WS2-SA,
+providing new potential efficacy for WS2 in ultrafast photonic applications.",1507.03188v1
+2015-08-11,CGC/saturation approach: a new impact-parameter dependent model,"{In this paper we propose a new impact-parameter dependent CGC/saturation
+model. We introduce two new features in the model that make it consistent with
+what we know theoretically about the deep inelastic scattering. They are: the
+use of the exact form of the solution to the non-linear (BK) equation, whereas
+in all previous attempts only the form of $r^2Q^2_s$ dependence, has been taken
+into account; and the large impact parameter dependence, through the
+$b$-dependence of the saturation momentum which reproduce the correct behaviour
+of the amplitude at large impact parameters $b$ ($A \propto \exp\Lb - \mu
+b\Rb$) as well as at large momentum transferred $Q_T$ ($A $ decreases as a
+power of $Q_T$ as it follows from perturbative QCD). These improvement compared
+to all previous attempts to build such models, allows us to claim, that the
+experimental data are in accord with the prediction of CGC/saturation approach
+while previously, based on similar models, we could only conclude that the DIS
+data, perhaps, can be described by introducing the shadowing corrections at
+small photon virtualities.",1508.02544v2
+2015-08-13,Intrinsic Fluctuations of the Proton Saturation Momentum Scale in High Multiplicity p+p Collisions,"High multiplicity events in p+p collisions are studied using the theory of
+the Color Glass Condensate. We show that intrinsic fluctuations of the proton
+saturation momentum scale are needed in addition to the sub-nucleonic color
+charge fluctuations to explain the very high multiplicity tail of distributions
+in p+p collisions. The origin of such intrinsic fluctuations are presumably
+non-perturbative in nature. Classical Yang Mills simulations using the
+IP-Glasma model are performed to make quantitative estimations. We find that
+fluctuations as large as $\cal O$(1) of the average values of the saturation
+momentum scale can lead to rare high multiplicity events seen in p+p data at
+RHIC and LHC energies. Using the available data on multiplicity distributions
+we try to constrain the distribution of the proton saturation momentum scale
+and make predictions for the multiplicity distribution in 13 TeV p+p
+collisions.",1508.03292v2
+2015-09-14,Correcting for accidental correlations in saturated avalanche photodiodes,"In this paper we present a general method for estimating rates of accidental
+coincidence between a pair of single photon detectors operated within their
+saturation regimes. By folding the effects of recovery time of both detectors
+and the detection circuit into an ""effective duty cycle"" we are able to
+accomodate complex recovery behaviour at high event rates. As an example, we
+provide a detailed high-level model for the behaviour of passively quenched
+avalanche photodiodes, and demonstrate effective background subtraction at
+rates commonly associated with detector saturation. We show that by
+post-processing using the updated model, we observe an improvement in
+polarization correlation visibility from 88.7% to 96.9% in our experimental
+dataset. This technique will be useful in improving the signal-to-noise ratio
+in applications which depend on coincidence measurements, especially in
+situations where rapid changes in flux may cause detector saturation.",1509.03959v3
+2015-10-02,Contact angle saturation in electrowetting: Injection of ions into the surrounding media,"We use the Poisson-Boltzmann theory to predict contact angle saturation of
+aqueous droplets in electrowetting. Our theory predicts that injection of ions
+from the droplet into its surrounding medium is responsible for the deviation
+of the apparent contact angle from the Young-Lippmann equation for large
+applied voltages. The ion injection substantially decreases the Maxwell stress
+and increases the osmotic pressure at the interface between the two media,
+leading to saturation of the apparent contact angle. Moreover, we find that the
+contact angle does not saturate, but only has a broad minimum that increases
+again upon further increase of the applied voltage, in agreement with
+experiments.",1510.00613v1
+2015-10-08,Formation of bubbly horizon in liquid-saturated porous medium by surface temperature oscillation,"We study non-isothermal diffusion transport of a weakly-soluble substance in
+a liquid-saturated porous medium being in contact with the reservoir of this
+substance. The surface temperature of the porous medium half-space oscillates
+in time, which results in a decaying solubility wave propagating deep into the
+porous medium. In such a system, the zones of saturated solution and
+non-dissolved phase coexist with the zones of undersaturated solution. The
+effect is firstly considered for the case of annual oscillation of the surface
+temperature of water-saturated ground being in contact with atmosphere. We
+reveal the phenomenon of formation of a near-surface bubbly horizon due to the
+temperature oscillation. An analytical theory of the phenomenon is developed.
+Further, the treatment is extended to the case of higher frequency oscillations
+and case of weakly-soluble solids and liquids.",1510.02459v2
+2015-10-26,Nuclear saturation in lowest-order Brueckner theory with two- and three-nucleon forces in view of chiral effective field theory,"The nuclear saturation mechanism is discussed in terms of two-nucleon and
+three-nucleon interactions in chiral effective field theory (Ch-EFT), using the
+framework of lowest-order Brueckner theory. After the Coester band, which is
+observed in calculating saturation points with various nucleon-nucleon (NN)
+forces, is revisited using modern NN potentials and their low-momentum
+equivalent interactions, detailed account of the saturation curve of the Ch-EFT
+interaction is presented. The three-nucleon force (3NF) is treated by reducing
+it to an effective two-body interaction by folding the third nucleon degrees of
+freedom. Uncertainties due to the choice of the 3NF low-energy constants $c_D$
+and $c_E$ are discussed. The reduction of the cutoff-energy dependence of the
+NN potential is explained by demonstrating the effect of the 3NF in the
+$^1$S$_0$ and $^3$S$_1$ states.",1510.07469v1
+2016-02-18,Revise Saturated Activation Functions,"In this paper, we revise two commonly used saturated functions, the logistic
+sigmoid and the hyperbolic tangent (tanh).
+  We point out that, besides the well-known non-zero centered property, slope
+of the activation function near the origin is another possible reason making
+training deep networks with the logistic function difficult to train. We
+demonstrate that, with proper rescaling, the logistic sigmoid achieves
+comparable results with tanh.
+  Then following the same argument, we improve tahn by penalizing in the
+negative part. We show that ""penalized tanh"" is comparable and even outperforms
+the state-of-the-art non-saturated functions including ReLU and leaky ReLU on
+deep convolution neural networks.
+  Our results contradict to the conclusion of previous works that the
+saturation property causes the slow convergence. It suggests further
+investigation is necessary to better understand activation functions in deep
+architectures.",1602.05980v2
+2016-02-26,Investigating the Temperature Effects on Resistive Random Access Memory (RRAM) Devices,"In this paper, we report the effect of filament radius and filament
+resistivity on the saturated temperature of ZnO, TiO2, WO3 and HfO2 Resistive
+Random Access Memory (RRAM) devices. We resort to the thermal reaction model of
+RRAM for the present analysis. The results substantiate decrease in saturated
+temperature with increase in the radius and resistivity of filament for the
+investigated RRAM devices. Moreover, a sudden change in the saturated
+temperature at a lower value of filament radius and resistivity is observed as
+against the steady change at the medium and higher value of the filament radius
+and resistivity. Results confirm the dependence of saturated temperature on the
+filament size and resistivity in RRAM.",1602.08262v1
+2016-03-03,Medium-induced gluon radiation in hard forward parton scattering in the saturation formalism,"We derive the medium-induced, coherent gluon radiation spectrum associated
+with the hard forward scattering of an energetic parton off a nucleus, in the
+saturation formalism and within the Gaussian approximation for the relevant
+correlators of Wilson lines. The calculation reproduces the simple expression
+for the spectrum previously obtained in the opacity expansion formalism, and
+rigorously specifies its validity range. The connection between the
+calculations in the opacity expansion and saturation formalisms is made
+apparent. This study may serve as a first step in order to implement
+consistently induced coherent energy loss and gluon shadowing in
+`saturation-based models' of hadron nuclear suppression in proton-nucleus
+collisions.",1603.01028v1
+2016-03-07,CGC/saturation approach for high energy soft interactions: $\mathbf{v_2}$ in proton-proton collisions,"In this paper we continue our program to construct a model for high energy
+soft interactions, based on the CGC/saturation approach. We demonstrate that in
+our model which describes diffractive physics as well as multi-particle
+production at high energy, the density variation mechanism leads to the value
+of $v_2$ which is about $60\% \div 70\%$ of the measured $v_2$. Bearing in mind
+that in CGC/saturation approach there are two other mechanisms present: Bose
+enhancement in the wave function and local anisotropy, we believe that the
+azimuthal long range rapidity correlations in proton-proton collisions stem
+from the CGC/saturation physics, and not from quark-gluon plasma production.",1603.02143v1
+2016-04-23,Determination of Oxygen Saturation and Photoplethysmogram from Near Infrared Scattering Images,"The near infrared scattering images of human muscle include some information
+on bloodstream and hemoglobin concentration according to skin depth and time.
+This paper addressed a method of determining oxygen saturation and
+photoplethysmogram from the near infrared (NIR) scattering images of muscle.
+Depending on the modified Beer-Lambert Law and the diffuse scattering model of
+muscular tissue, we determined an extinction coefficient matrix of hemoglobin
+from the near infrared scattering images and analyzed distribution of oxygen
+saturation of muscle with a depth from the extinction coefficient matrix. And
+we determined a dynamic attenuation variation curve with respect to fragmentary
+image frames sensitive to bloodstream from scattering image frames of muscle
+with time and then obtained the photoplethysmogram and heart rate by Fourier
+transformation and inverse transformation. This method based on the NIR
+scattering images can be applied in measurement of an average oxygen saturation
+and photoplethysmogram even in local region of optically heterogeneous muscle
+and skin.",1604.06855v1
+2016-04-24,Saturation of Nuclear Matter and Roles of Many-Body Forces: nuclear matter in neutron stars probed by nucleus-nucleus scattering,"Yoichiro Nambu put a great foot print in nuclear physics in the era of its
+fundamental developments including his pioneering insight into essential
+ingredients of repulsive core of nuclear force and its relation to the
+saturation of nuclear matter. The present review article focuses onto recent
+developments of the interaction models between colliding nuclei in terms of
+Brueckner's G-matrix theory staring from realistic nuclear forces and the
+saturation property of symmetric nuclear matter as well as neutron-star matter.
+A recently proposed unique scenario of extracting the saturation property of
+nuclear matter and stiffness of neutron stars through the analysis of
+nucleus-nucleus elastic scattering in laboratories is presented in some detail.",1604.07632v1
+2015-12-11,Scrape-off layer turbulence in TCV: evidence in support of stochastic modelling,"Intermittent fluctuations in the TCV scrape-off layer have been investigated
+by analysing long Langmuir probe data time series under stationary conditions,
+allowing calculation of fluctuation statistics with high accuracy. The ion
+saturation current signal is dominated by the frequent occurrence of
+large-amplitude bursts attributed to filament structures moving through the
+scrape-off layer. The average burst shape is well described by a
+double-exponential wave-form with constant duration, while the waiting times
+and peak amplitudes of the bursts both have an exponential distribution.
+Associated with bursts in the ion saturation current is a dipole shaped
+floating potential structure and radially outwards directed electric drift
+velocity and particle flux, with average peak values increasing with the
+saturation current burst amplitude. The floating potential fluctuations have a
+normal probability density function while the distributions for the ion
+saturation current and estimated radial velocity have exponential tails for
+large fluctuations. These findings are discussed in the light of prevailing
+theories for filament motion and a stochastic model for intermittent scrape-off
+layer plasma fluctuations.",1604.08163v1
+2016-07-12,Saturation scale fluctuations and multi-particle rapidity correlations,"We study the effect of intrinsic fluctuations of the proton saturation
+momentum scale on event-by-event rapidity distributions. Saturation scale
+fluctuations generate an asymmetry in the single particle rapidity distribution
+in each event resulting in genuine n-particle correlations having a component
+linear in the rapidities of the produced particles, $y_1\cdots y_n$. We
+introduce a color domain model that naturally explains the centrality
+dependence of the two-particle rapidity correlations recently measured by ATLAS
+while constraining the probability distribution of saturation scale
+fluctuations in the proton. Predictions for n = 4, 6 and 8 particle
+correlations find that the four and eight-particle cumulant change sign at an
+intermediate multiplicity, a signature which could be tested experimentally.",1607.03219v1
+2016-07-15,High Gluon Densities in Heavy Ions Collisions,"The early stages of heavy ion collisions are dominated by high density
+systems of gluons that carry each a small fraction $x$ of the momenta of the
+colliding nucleons. A distinguishing feature of such systems is the phenomenon
+of ""saturation"" which tames the expected growth of the gluon density as the
+energy of the collision increases. The onset of saturation occurs at a
+particular transverse momentum scale, the ""saturation momentum"", that emerges
+dynamically and that marks the onset of non-linear gluon interactions. At high
+energy, and for large nuclei, the saturation momentum is large compared to the
+typical hadronic scale, making high density gluons amenable to a description
+with weak coupling techniques. This paper reviews some of the challenges faced
+in the study of such dense systems of small $x$ gluons, and of the progress
+made in addressing them. The focus is on conceptual issues, and the
+presentation is both pedagogical, and critical. Examples where high gluon
+density could play a visible role in heavy ion collisions are briefly discussed
+at the end, for illustration purpose.",1607.04448v1
+2016-07-19,Non-quasiparticle transport and resistivity saturation: A view from the large-N limit,"The electron dynamics in metals are usually well described by the
+semiclassical approximation for long-lived quasiparticles. However, in some
+metals, the scattering rate of the electrons at elevated temperatures becomes
+comparable to the Fermi energy; then, this approximation breaks down, and the
+full quantum-mechanical nature of the electrons must be considered. In this
+work, we study a solvable, large-$N$ electron-phonon model, which at high
+temperatures enters the non-quasiparticle regime. In this regime, the model
+exhibits ""resistivity saturation"" to a temperature-independent value of the
+order of the quantum of resistivity - the first analytically tractable model to
+do so. The saturation is not due to a fundamental limit on the electron
+lifetime, but rather to the appearance of a second conductivity channel. This
+is suggestive of the phenomenological ""parallel resistor formula"", known to
+describe the resistivity of a variety of saturating metals.",1607.05725v1
+2016-09-06,Global stabilization of a Korteweg-de Vries equation with a distributed control saturated in L 2 -norm,"This article deals with the design of saturated controls in the context of
+partial differential equations. It is focused on a Korteweg-de Vries equation,
+which is a nonlinear mathematical model of waves on shallow water surfaces. The
+aim of this article is to study the influence of a saturating in L 2-norm
+distributed control on the well-posedness and the stability of this equation.
+The well-posedness is proven applying a Banach fixed point theorem. The proof
+of the asymptotic stability of the closed-loop system is tackled with a
+Lyapunov function together with a sector condition describing the saturating
+input. Some numerical simulations illustrate the stability of the closed-loop
+nonlinear partial differential equation.",1609.01447v1
+2016-12-02,A Novel Framework based on SVDD to Classify Water Saturation from Seismic Attributes,"Water saturation is an important property in reservoir engineering domain.
+Thus, satisfactory classification of water saturation from seismic attributes
+is beneficial for reservoir characterization. However, diverse and non-linear
+nature of subsurface attributes makes the classification task difficult. In
+this context, this paper proposes a generalized Support Vector Data Description
+(SVDD) based novel classification framework to classify water saturation into
+two classes (Class high and Class low) from three seismic attributes seismic
+impedance, amplitude envelop, and seismic sweetness. G-metric means and program
+execution time are used to quantify the performance of the proposed framework
+along with established supervised classifiers. The documented results imply
+that the proposed framework is superior to existing classifiers. The present
+study is envisioned to contribute in further reservoir modeling.",1612.00841v1
+2017-01-25,Solution to the evolution equation at NLL for high parton density QCD,"We analytically solve the full next-to-leading logarithmic Balitsky-Kovchegov
+equation in the saturation regime, which includes corrections from quark and
+gluon loops, and large double transverse logarithms. The analytic result for
+the $S$-matrix in the saturation regime shows that the linear rapidity decrease
+with rapidity of the exponent in running coupling case is replaced by rapidity
+raised to power of 3/2 decreasing. The collinearly-improved Balitsky-Kovchegov
+equation are also analytically solved in the saturation regime. It shows that
+the double collinear logarithms do not contribute to the $S$-matrix and the
+solution is the same as the one obtained from the leading order
+Balitsky-Kovchegov equation. The numerical solutions to the leading order and
+full next-to-leading logarithmic Balitsky-Kovchegov equations are performed in
+order to test the analytic results derived in the saturation regime.",1701.07378v1
+2017-02-02,Unveiling saturation effects from nuclear structure function measurements at the EIC,"We analyze the possibility of extracting a clear signal of non-linear parton
+saturation effects from future measurements of nuclear structure functions at
+the Electron-Ion Collider (EIC), in the small-x region. Our approach consists
+in generating pseudodata for electron-gold collisions, using the
+running-coupling Balitsky-Kovchegov evolution equation, and in assessing the
+compatibility of these saturate pseudodata with existing sets of nuclear parton
+distribution functions (nPDFs), extrapolated if necessary. The level of
+disagreement between the two is quantified by applying a Bayesian reweighting
+technique. This allows to infer the parton distributions needed in order to
+describe the pseudodata, which we find quite different from the actual
+distributions, especially for sea quarks and gluons. This tension suggests
+that, should saturation effects impact the future nuclear structure function
+data as predicted, a successful refitting of the nPDFs may not be achievable,
+which would unambiguously signal the presence of non-linear effects.",1702.00839v4
+2017-02-21,Mixed-gap vector solitons in PT-symmetric lattices with saturable nonlinearity,"We have investigated mixed-gap vector solitons involving incoherently coupled
+fundamental and dipole components in a parity-time (PT) symmetric lattice with
+saturable nonlinearity. For the focusing case, vector solitons emerge from the
+semi-infinite and the first finite gaps, while for the defocusing case, vector
+solitons emerge from the first finite and the second finite gaps. For both
+cases, we find that stronger saturable nonlinearity is relative to sharper
+increase/decrease of soliton power with propagation constant and to narrower
+existence domain of vector solitons. This finding is helpful for realizing
+high-power solitons with limited range of propagation constant. Additionally,
+our numerical calculations show that increasing the weight of dipole component
+results in destabilization of vector solitons, while stronger saturable
+nonlinearity to certain extent suppresses the instability of vector solitons.",1702.06232v1
+2017-02-25,Upper bounds on the smallest size of a saturating set in projective planes and spaces of even dimension,"In a projective plane $\Pi_{q}$ (not necessarily Desarguesian) of order $q$,
+a point subset $\mathcal{S}$ is saturating (or dense) if any point of
+$\Pi_{q}\setminus \mathcal{S}$ is collinear with two points in $\mathcal{S}$.
+Modifying an approach of [31], we proved the following upper bound on the
+smallest size $s(2,q)$ of a saturating set in $\Pi_{q}$: \begin{equation*}
+s(2,q)\leq \sqrt{(q+1)\left(3\ln q+\ln\ln q
++\ln\frac{3}{4}\right)}+\sqrt{\frac{q}{3\ln q}}+3. \end{equation*} The bound
+holds for all q, not necessarily large.
+  By using inductive constructions, upper bounds on the smallest size of a
+saturating set in the projective space $\mathrm{PG}(N,q)$ with even dimension
+$N$ are obtained.
+  All the results are also stated in terms of linear covering codes.",1702.07939v1
+2017-03-01,Multistability and Switching in Oppositely Directed Saturable Coupler,"We report a novel optical multistability in two core oppositely directed
+saturable coupler (ODSC) with negative index material (NIM) channel. The
+dynamics are studied using the Langrangian variational method and Jacobi
+elliptic functions are used to construct the analytical solutions. The ODSC
+exhibits a bandgap as a consequence of the effective feedback mechanism due to
+the opposite directionality of the phase velocity and Poynting vector in the
+NIM channel. We observe that the system admits multiple stable states for some
+control parameter, which is a result of the combination of nonlinear saturation
+and the unique backward-coupling mechanism in the NIM channel. The number of
+multiple stable states increase with the strength of the nonlinear saturation.
+Taking the advantage of multiple stable states, one can construct ultrafast
+switching devices with a flexible switching operation. The studies on the
+transmission characteristics of the ODSC implies the existence of multiple
+transmission resonance windows, which could help in the realization of gap
+soliton in homogeneous systems like coupler. With more degrees of design
+freedom and controllability, the ODSC could be the choice for a future
+generation of all-optical switching.",1703.00486v1
+2017-03-30,The unsaturated flow in porous media with dynamic capillary pressure,"In this paper we consider a degenerate pseudoparabolic equation for the
+wetting saturation of an unsaturated two-phase flow in porous media with
+dynamic capillary pressure-saturation relationship where the relaxation
+parameter depends on the saturation. Following the approach given in [12] the
+existence of a weak solution is proved using Galerkin approximation and
+regularization techniques. A priori estimates needed for passing to the limit
+when the regularization parameter goes to zero are obtained by using
+appropriate test-functions, motivated by the fact that considered PDE allows a
+natural generalization of the classical Kullback entropy. Finally, a special
+care was given in obtaining an estimate of the mixed derivative term by
+combining the information from the capillary pressure with obtained a priori
+estimates on the saturation.",1703.10662v2
+2017-04-18,Distributed Event-Triggered Control for Global Consensus of Multi-Agent Systems with Input Saturation,"We consider the global consensus problem for multi-agent systems with input
+saturation over digraphs. Under a mild connectivity condition that the
+underlying digraph has a directed spanning tree, we use Lyapunov methods to
+show that the widely used distributed consensus protocol, which solves the
+consensus problem for the case without input saturation constraints, also
+solves the global consensus problem for the case with input saturation
+constraints. In order to reduce the overall need of communication and system
+updates, we then propose a distributed event-triggered control law. Global
+consensus is still realized and Zeno behavior is excluded. Numerical
+simulations are provided to illustrate the effectiveness of the theoretical
+results.",1704.05429v1
+2017-05-15,Doppler-free resolution near-infrared spectroscopy at 1.28~$μ$m with the noise-immune cavity-enhanced optical heterodyne molecular spectroscopy method,"We report on the Doppler-free saturation spectroscopy of the nitrous oxide
+(N$_2$O) overtone transition at 1.28~$\mu$m. This measurement is performed by
+the noise-immune cavity-enhanced optical heterodyne molecular spectroscopy
+(NICE-OHMS) technique based on the quantum-dot (QD) laser. A high intra-cavity
+power, up to 10~W, reaches the saturation limit of the overtone line using an
+optical cavity with a high finesse of 113,500. At a pressure of several mTorr,
+the saturation dip is observed with a full width at half-maximum of about 2~MHz
+and a signal-to-noise ratio of 71. To the best of our knowledge, this is the
+first saturation spectroscopy of molecular overtone transitions in 1.3~$\mu$m
+region. The QD laser is then locked to this dispersion signal with a stability
+of 15 kHz at 1 sec integration time. We demonstrate the potential of the N$_2$O
+as markers because of its particularly rich spectrum at the vicinity of
+1.28-1.30 $\mu$m where lies several important forbidden transitions of atomic
+parity violation measurements and the 1.3 $\mu$m O-band of optical
+communication.",1705.05208v1
+2017-07-22,Dynamical phase diagram of parity-time symmetry with competing saturable channels,"Nonlinear channels play a critical role in realizing dynamical functions.
+Neural ionic channels and non-volatile memristors each derive representative
+biological and electrical functionalities, such as repetitive firing or pinched
+hysteresis. In electromagnetics, saturable channels of amplification or
+absorption provide a large nonlinearity for nonequilibrium wave dynamics, from
+conventional lasing to mode locking to recent achievements of the
+non-reciprocity in complex potentials. Here, we investigate the dynamical phase
+diagram of parity-time symmetric systems, governed by competing nonlinear
+channels of saturable amplification and absorption. Determined by the relative
+strength and saturation level of the channels, three distinctive phases of
+fast- and slow-response equilibriums, and an oscillating nonequilibrium are
+demonstrated. On phase boundaries, we also reveal the chaotic existence of the
+strong oscillation state, which allows the non-reciprocal realization of
+repetitive resonator firing with fully tunable time delays. This work will
+promote the wave-based realization of nonlinear and chaotic temporal functions,
+toward light-based neural systems.",1707.07096v1
+2017-08-11,"Nonreciprocal Atomic Scattering: A saturable, quantum Yagi-Uda antenna","Recent theoretical studies of a pair of atoms in a 1D waveguide find that the
+system responds asymmetrically to incident fields from opposing directions at
+low powers. Since there is no explicit time-reversal symmetry breaking elements
+in the device, this has caused some debate. Here we show that the asymmetry
+arises from the formation of a quasi-dark-state of the two atoms, which
+saturates at extremely low power. In this case the nonlinear saturability
+explicitly breaks the assumptions of the Lorentz reciprocity theorem. Moreover,
+we show that the statistics of the output field from the driven system can be
+explained by a very simple stochastic mirror model and that at steady state,
+the two atoms and the local field are driven to an entangled, tripartite
+$\left| W \right\rangle$ state. Because of this, we argue that the device is
+better understood as a saturable Yagi-Uda antenna, a distributed system of
+differentially-tuned dipoles that couples asymmetrically to external fields.",1708.03450v2
+2017-08-19,An efficient distribution method for nonlinear two-phase flow in highly heterogeneous multidimensional stochastic porous media,"In the context of stochastic two-phase flow in porous media, we introduce a
+novel and efficient method to estimate the probability distribution of the
+wetting saturation field under uncertain rock properties in highly
+heterogeneous porous systems, where streamline patterns are dominated by
+permeability heterogeneity, and for slow displacement processes (viscosity
+ratio close to unity). Our method, referred to as the frozen streamline
+distribution method (FROST), is based on a physical understanding of the
+stochastic problem. Indeed, we identify key random fields that guide the
+wetting saturation variability, namely fluid particle times of flight and
+injection times. By comparing saturation statistics against full-physics Monte
+Carlo simulations, we illustrate how this simple, yet accurate FROST method
+performs under the preliminary approximation of frozen streamlines. Further, we
+inspect the performance of an accelerated FROST variant that relies on a
+simplification about injection time statistics. Finally, we introduce how
+quantiles of saturation can be efficiently computed within the FROST framework,
+hence leading to robust uncertainty assessment.",1708.05888v1
+2017-10-13,Compressive three-dimensional super-resolution microscopy with speckle-saturated fluorescence excitation,"Nonlinear structured illumination microscopy (nSIM) is an effective approach
+for super-resolution wide-field fluorescence microscopy with a theoretically
+unlimited resolution. In nSIM, carefully designed, highly-contrasted
+illumination patterns are combined with the saturation of an optical transition
+to enable sub-diffraction imaging. While the technique proved useful for
+two-dimensional imaging, extending it to three-dimensions (3D) is challenging
+due to the fading/fatigue of organic fluorophores under intense cycling
+conditions. Here, we present a compressed sensing approach that allows for the
+first time 3D sub-diffraction nSIM of cultured cells by saturating fluorescence
+excitation. Exploiting the natural orthogonality of transverse speckle
+illumination planes, 3D probing of the sample is achieved by a single
+two-dimensional scan. Fluorescence contrast under saturated excitation is
+ensured by the inherent high density of intensity minima associated with
+optical vortices in polarized speckle patterns. Compressed speckle microscopy
+is thus a simple approach that enables 3D super-resolved nSIM imaging with
+potentially considerably reduced acquisition time and photobleaching.les fast
+3D super-resolved imaging with considerably minimized photo-bleaching.",1710.05056v2
+2017-10-31,High Saturation Power Josephson Parametric Amplifier with GHz Bandwidth,"We present design and simulation of a Josephson parametric amplifier with
+bandwidth exceeding 1.6 GHz, and with high saturation power approaching -90 dBm
+at a gain of 22.8 dB. An improvement by a factor of roughly 50 in bandwidth
+over the state of the art is achieved by using well-established impedance
+matching techniques. An improvement by a factor of roughly 100 in saturation
+power over the state of the art is achieved by implementing the Josephson
+nonlinear element as an array of rf-SQUIDs with a total of 40 junctions.
+WRSpice simulations of the circuit are in excellent agreement with the
+calculated gain and saturation characteristics.",1711.07549v1
+2017-12-29,Chaotic Dynamics and Optical Power Saturation in Parity-Time (PT) Symmetric Double Ring Resonator,"We report emergence of saturation and chaotic spiking of optical power in a
+double ring resonator with balanced loss and gain, obeying the so-called
+parity-time symmetry. We have modeled the system using a discrete-time
+iterative equation known as the Ikeda Map. In the linear regime, evolution of
+optical power in the system shows power saturation behavior below the PT
+threshold and exponential blow-up above the PT threshold. We found that in the
+unbroken PT regime, optical power saturation occurs owing to the existence of
+stable stationary states, which lies on the surface of 4-dimensional
+hypersphere. Inclusion of Kerr nonlinearity into our model leads to the
+emergence of a stable, chaotic and divergent region in the parameter basin for
+period-1 cycle. A closer inspection into the system shows us that the largest
+Lyapunov exponent blows up in the divergent region. It is found that the
+existence of high non-negative largest Lyapunov exponent causes chaotic spiking
+of optical power in the resonators.",1712.10196v2
+2018-01-01,Note on lower estimates of multiplicities,"In this note we would like to give an explicit lower bound by using a lower
+saturated subset of \mathbb{R}_{\geq 0}^n.",1801.00525v1
+2018-03-19,Model theory and ultraproducts,"The article motivates recent work on saturation of ultrapowers from a general
+mathematical point of view.",1803.07118v1
+2018-04-10,Optical solitons in media with focusing and defocusing saturable nonlinearity and a parity-time-symmetric external potential,"We report results for solitons in models of waveguides with focusing or
+defocusing saturable nonlinearity and a parity-time(PT )-symmetric
+complex-valued external potential of the Scarf-II type. The model applies to
+the nonlinear wave propagation in graded-index optical waveguides with balanced
+gain and loss. We find both fundamental and multipole solitons for both
+focusing and defocusing signs of the saturable nonlinearity in such PT
+-symmetric waveguides. The dependence of the propagation constant on the
+soliton's power is presented for different strengths of the nonlinearity
+saturation, S. The stability of fundamental, dipole, tripole, and quadrupole
+solitons is investigated by means of the linear-stability analysis and direct
+numerical simulations of the corresponding (1+1)-dimensional nonlinear
+Schrodinger-type equation. The results show that the instability of the
+stationary solutions can be mitigated or completely suppressed, increasing the
+value of S.",1804.03314v1
+2018-04-24,On the saturation conjecture for $\operatorname{Spin}(2n)$,"In this paper we examine the saturation conjecture on decompositions of
+tensor products of irreducible representations for complex semisimple algebraic
+groups of type $D$ (the even \emph{spin} groups: Spin$(2n)$ for $n\ge 4$ an
+integer), extending work done by Kumar-Kapovich-Millson on Spin(8). Our main
+theorem asserts that the saturation conjecture holds for Spin(10) and Spin(12):
+for all triples of dominants weights $\lambda,\mu,\nu$ such that
+$\lambda+\mu+\nu$ is in the root lattice, and for any $N>0$, $$
+\left(V(\lambda)\otimes V(\mu)\otimes V(\nu)\right)^G \ne 0 $$ if and only if
+$$ \left(V(N\lambda)\otimes V(N\mu)\otimes V(N\nu)\right)^G\ne 0, $$ for $G=$
+Spin(10) or Spin(12). Some related results for groups of other types are listed
+as well.",1804.09229v3
+2018-06-09,Saturable impurity in an optical array: Green function approach,"We examine a one-dimensional linear waveguide array containing a single
+saturable waveguide. By using the formalism of lattice Green functions, we
+compute in closed form the localized mode and the transmission across the
+impurity in closed form. For the single saturable impurity in the bulk, we find
+that an impurity state is always possible, independent of the impurity
+strength. For the surface saturable impurity case, a minimum nonlinearity
+strength is necessary to create a bound state. The transmission coefficient
+across the impurity shows a sub-linear behavior with an absence of any
+resonance. The dynamical selftrapping at the bulk impurity site shows no
+selftrapping transition, and it resembles the behavior of a weak linear
+impurity. For the surface impurity however, there is a selftrapping transition
+at a critical nonlinearity value. The asymptotic propagation of the optical
+power shows a ballistic character in both cases, with a speed that decreases
+with an increase in nonlinearity strength.",1806.03491v1
+2018-06-26,Understanding Dropout as an Optimization Trick,"As one of standard approaches to train deep neural networks, dropout has been
+applied to regularize large models to avoid overfitting, and the improvement in
+performance by dropout has been explained as avoiding co-adaptation between
+nodes. However, when correlations between nodes are compared after training the
+networks with or without dropout, one question arises if co-adaptation
+avoidance explains the dropout effect completely. In this paper, we propose an
+additional explanation of why dropout works and propose a new technique to
+design better activation functions. First, we show that dropout can be
+explained as an optimization technique to push the input towards the saturation
+area of nonlinear activation function by accelerating gradient information
+flowing even in the saturation area in backpropagation. Based on this
+explanation, we propose a new technique for activation functions, {\em gradient
+acceleration in activation function (GAAF)}, that accelerates gradients to flow
+even in the saturation area. Then, input to the activation function can climb
+onto the saturation area which makes the network more robust because the model
+converges on a flat region. Experiment results support our explanation of
+dropout and confirm that the proposed GAAF technique improves image
+classification performance with expected properties.",1806.09783v3
+2018-06-26,Anomalous optical saturation of low-energy Dirac states in graphene and its implication for nonlinear optics,"We reveal that optical saturation of the low-energy states takes place in
+graphene for arbitrarily weak electromagnetic fields. This effect originates
+from the diverging field-induced interband coupling at the Dirac point. Using
+semiconductor Bloch equations to model the electronic dynamics of graphene, we
+argue that the charge carriers undergo ultrafast Rabi oscillations leading to
+the anomalous saturation effect. The theory is complemented by a many-body
+study of the carrier relaxations dynamics in graphene. It will be demonstrated
+that the carrier relaxation dynamics is slow around the Dirac point, which in
+turn leads to a more pronounced saturation. The implications of this effect to
+the nonlinear optics of graphene is then discussed. Our analysis show that the
+conventional perturbative treatment of the nonlinear optics, i.e., expanding
+the polarization field in a Taylor series of the electric field, is problematic
+for graphene, in particular at small Fermi levels and large field amplitudes.",1806.10123v2
+2018-11-18,STOAViz: Visualizing Saturated Thickness of Ogallala Aquifer,"In this paper, we introduce STOAViz, a visual analytics tool for analyzing
+the saturated thickness of the Ogallala aquifer. The saturated thicknesses are
+monitored by sensors integrated on wells distributed on a vast geographic area.
+Our analytics application also captures the trends and patterns (such as
+average/standard deviation over time, sudden increase/decrease of saturated
+thicknesses) of water on an individual well and a group of wells based on their
+geographic locations. To highlight the usefulness and effectiveness of STOAViz,
+we demonstrate it on the Southern High Plains Aquifer of Texas. The work was
+developed using feedback from experts at the water resource center at a
+university. Moreover, our technique can be applied on any geographic areas
+where wells and their measurements are available.",1811.07385v1
+2018-11-22,Exclusive $ρ$ and $J/Ψ$ photoproduction in ultraperipheral $pA$ collisions: Predictions of the gluon saturation models for the momentum transfer distributions,"In this letter we complement previous studies on exclusive vector meson
+photoproduction in hadronic collisions presenting a comprehensive analysis of
+the $t$ - spectrum measured in exclusive $\rho$ and $J/\Psi$ photoproduction in
+$pA$ collisions at the LHC. We compute the differential cross sections
+considering two phenomenological models for the gluon saturation effects and
+present predictions for $pPb$ and $pCa$ collisions. Moreover, we compare our
+predictions with the recent preliminary CMS data for the exclusive $\rho$
+photoproduction. We demonstrate that the gluon saturation models are able to
+describe the CMS data at small - $t$. On the other hand, the models
+underestimate the few data point at large -- $t$. Our results indicate that
+future measurements of the large -- $t$ region can be useful to probe the
+presence or absence of a dip in the $t$ -- spectrum and discriminate between
+the different approaches to the gluon saturation effects.",1811.09124v1
+2018-11-28,Entanglement Evolution in Lifshitz-type Scalar Theories,"We study propagation of entanglement after a mass quench in free scalar
+Lifshitz theories. We show that entanglement entropy goes across three distinct
+growth regimes before relaxing to a generalized Gibbs ensemble, namely 'initial
+rapid growth', 'main linear growth' and 'tortoise saturation'. We show that
+although a wide spectrum of quasi-particles are responsible for entanglement
+propagation, as long as the occupation number of the zero mode is not
+divergent, the linear main growth regime is dominated by the fastest
+quasi-particle propagating on the edges of a widen light-cone. We present
+strong evidences in support of effective causality and therefore define an
+effective notion of saturation time in these theories. The larger the dynamical
+exponent is, the shorter the linear main growth regime becomes. Due to a pile
+of tortoise modes which become dominant after saturation of fast modes, exact
+saturation time is postponed to infinity.",1811.11470v2
+2019-01-17,Adaptive backstepping control for FOS with nonsmooth nonlinearities,"This paper proposes an original solution to input saturation and dead zone of
+fractional order system. To overcome these nonsmooth nonlinearities, the
+control input is decomposed into two independent parts by introducing an
+intermediate variable, and thus the problem of dead zone and saturation
+transforms into the problem of disturbance and saturation afterwards. With the
+procedure of fractional order adaptive backstepping controller design, the
+bound of disturbance is estimated, and saturation is compensated by the virtual
+signal of an auxiliary system as well. In spite of the existence of nonsmooth
+nonlinearities, the output is guaranteed to track the reference signal
+asymptotically on the basis of our proposed method. Some simulation studies are
+carried out in order to demonstrate the effectiveness of method at last.",1901.05588v1
+2019-01-22,Towards Non-saturating Recurrent Units for Modelling Long-term Dependencies,"Modelling long-term dependencies is a challenge for recurrent neural
+networks. This is primarily due to the fact that gradients vanish during
+training, as the sequence length increases. Gradients can be attenuated by
+transition operators and are attenuated or dropped by activation functions.
+Canonical architectures like LSTM alleviate this issue by skipping information
+through a memory mechanism. We propose a new recurrent architecture
+(Non-saturating Recurrent Unit; NRU) that relies on a memory mechanism but
+forgoes both saturating activation functions and saturating gates, in order to
+further alleviate vanishing gradients. In a series of synthetic and real world
+tasks, we demonstrate that the proposed model is the only model that performs
+among the top 2 models across all tasks with and without long-term
+dependencies, when compared against a range of other architectures.",1902.06704v1
+2019-03-31,Robust Extended Kalman Filtering for Systems with Measurement Outliers,"Outliers can contaminate the measurement process of many nonlinear systems,
+which can be caused by sensor errors, model uncertainties, change in ambient
+environment, data loss or malicious cyber attacks. When the extended Kalman
+filter (EKF) is applied to such systems for state estimation, the outliers can
+seriously reduce the estimation accuracy. This paper proposes an innovation
+saturation mechanism to modify the EKF toward building robustness against
+outliers. This mechanism applies a saturation function to the innovation
+process that the EKF leverages to correct the state estimation. As such, when
+an outlier occurs, the distorting innovation is saturated and thus prevented
+from damaging the state estimation. The mechanism features an adaptive
+adjustment of the saturation bound. The design leads to the development robust
+EKF approaches for continuous- and discrete-time systems. They are proven to be
+capable of generating bounded-error estimation in the presence of bounded
+outlier disturbances. An application study about mobile robot localization is
+presented, with the numerical simulation showing the efficacy of the proposed
+design. Compared to existing methods, the proposed approaches can effectively
+reject outliers of various magnitudes, types and durations, at significant
+computational efficiency and without requiring measurement redundancy.",1904.00335v1
+2019-04-06,On the saturation of acoustic mode frequencies at high solar activity,"Acoustic mode frequencies obtained by applying spherical harmonic
+decomposition to HMI, MDI and GONG observations were analysed throughout the
+solar cycle. Evidence of a deviation from a linear relation with solar radio
+flux was found indicating a saturation effect at high solar activity. The
+Gompertz model, which is one of the most frequently used sigmoid functions to
+fit growth data, is used. It is shown that its fitting to MDI and GONG data are
+statistically significant and a median saturation of four-hundred sfu is
+estimated. This saturation level is 50% larger than any obtained in the last
+century, hence the small effect observed in the minimum-to-maximum frequency
+shift. However, as shown here, it should not be disregarded.",1904.03452v1
+2019-05-09,Diffractive dijet production in impact parameter dependent saturation models,"We study coherent diffractive dijet production in electron-hadron and
+electron-nucleus collisions within the dipole picture. We provide semi-analytic
+results for the differential cross section and elliptic anisotropy in the angle
+between dijet transverse momentum and hadron recoil momentum. We demonstrate
+the direct relation between angular moments of the dipole amplitude in
+coordinate space and angular moments of the diffractive dijet cross sections.
+To perform explicit calculations we employ two different saturation models,
+extended to include the target geometry. In the limit of large photon
+virtuality or quark masses, we find fully analytic results that allow direct
+insight into how the differential cross section and elliptic anisotropy depend
+on the saturation scale, target geometry, and kinematic variables. We further
+provide numerical results for more general kinematics in collisions at a future
+electron-ion collider, and study the effects of approaching the saturated
+regime on diffractive dijet observables.",1905.03763v2
+2019-06-17,Charging of quantum batteries with general harmonic power,"We analyse the charging process of quantum batteries with general harmonic
+power. To describe the charge efficiency, we introduce the charge saturation
+and the charging power, and divide the charging mode into the saturated
+charging mode and the unsaturated charging mode. The relationships between the
+time-dependent charge saturation and the parameters of general driving field
+are discussed both analytically and numerically. And according to the Floquet
+theorem, we give the expressions of time-dependent charge saturation with the
+quasiengery and the Floquet states of the system. With both the analytical and
+numerical results, we find the optimal parameters to reach the best charging
+efficiency.",1906.06880v2
+2019-06-20,Eddy saturation of the Southern Ocean: a baroclinic versus barotropic perspective,"""Eddy saturation"" is the regime in which the total time-mean volume transport
+of an oceanic current is relatively insensitive to the wind stress forcing and
+is often invoked as a dynamical description of Southern Ocean circulation. We
+revisit the problem of eddy saturation using a primitive-equations model in an
+idealized channel setup with bathymetry. We apply only mechanical wind stress
+forcing; there is no diapycnal mixing or surface buoyancy forcing. Our main aim
+is to assess the relative importance of two mechanisms for producing eddy
+saturated states: (i) the commonly invoked baroclinic mechanism that involves
+the competition of sloping isopycnals and restratification by production of
+baroclinic eddies, and (ii) the barotropic mechanism, that involves production
+of eddies through lateral shear instabilities or through the interaction of the
+barotropic current with bathymetric features. Our results suggest that the
+barotropic flow-component plays a crucial role in determining the total volume
+transport.",1906.08442v3
+2019-07-10,A positivity preserving iterative method for finding the ground states of saturable nonlinear Schrödinger equations,"In this paper, we propose an iterative method to compute the positive ground
+states of saturable nonlinear Schr\""odinger equations. A discretization of the
+saturable nonlinear Schr\""odinger equation leads to a nonlinear algebraic
+eigenvalue problem (NAEP). For any initial positive vector, we prove that this
+method converges globally with a locally quadratic convergence rate to a
+positive solution of NAEP. During the iteration process, the method requires
+the selection of a positive parameter $\theta_k$ in the $k$th iteration, and
+generates a positive vector sequence approximating the eigenvector of NAEP and
+a scalar sequence approximating the corresponding eigenvalue. We also present a
+halving procedure to determine the parameters $\theta_k$, starting with
+$\theta_k=1$ for each iteration, such that the scalar sequence is strictly
+monotonic increasing. This method can thus be used to illustrate the existence
+of positive ground states of saturable nonlinear Schr\""odinger equations.
+Numerical experiments are provided to support the theoretical results.",1907.04644v1
+2019-10-08,Optimal L-Infinity Frequency Control in Microgrids Considering Actuator Saturation,"Inverter-connected resources can improve transient stability in low-inertia
+grids by injecting active power to minimize system frequency deviations
+following disturbances. In practice, most generation and load disturbances are
+step changes and the engineering figure-of-merit is often the peak overshoot in
+frequency resulting from these step disturbances. In addition, the
+inverter-connected resources tend to saturate much more easily than
+conventional synchronous machines. However, despite these challenges, standard
+controller designs must deal with averaged quantities through $H_2$ or
+$H_\infty$ norms and must account for saturation in ad hoc manners. In this
+paper, we address these challenges by explicitly considering $L_\infty$ control
+with saturation using a linear matrix inequality-based approach. We show that
+this approach leads to significant improvements in stability performance.",1910.03720v1
+2019-10-11,"The saturation number of $K_{3,3}$","A graph $G$ is called $F$-saturated if $G$ does not contain $F$ as a subgraph
+(not necessarily induced) but the addition of any missing edge to $G$ creates a
+copy of $F$. The saturation number of $F$, denoted by $sat(n,F)$, is the
+minimum number of edges in an $n$-vertex $F$-saturated graph. Determining the
+saturation number of complete partite graphs is one of the most important
+problems in the study of saturation number. The value of $sat(n,K_{2,2})$ was
+shown to be $\lfloor\frac{3n-5}{2}\rfloor$ by Ollmann, and a shorter proof was
+later given by Tuza. For $K_{2,3}$, there has been a series of study aiming to
+determine $sat(n,K_{2,3})$ over the years. This was finally achieved by Chen
+who confirmed a conjecture of Bohman, Fonoberova, and Pikhurko that $sat(n,
+K_{2,3})= 2n-3$ for all $n\geq 5$. In this paper, we prove a conjecture of
+Pikhurko and Schmitt that $sat(n, K_{3,3})=3n-9$ when $n \geq 9$.",1910.04967v2
+2019-10-28,Saturation corrections to dilute-dense particle production and azimuthal correlations in the Color Glass Condensate,"We perform a numerical study of higher order saturation corrections to the
+dilute-dense approximation for multi-particle production in high-energy
+hadronic collisions in the framework of the Color Glass Condensate. We compare
+semi-analytical results obtained by performing a leading order expansion in the
+dilute field of the projectile with numerical simulations of the full Classical
+Yang-Mills dynamics for a number of phenomenologically relevant observables. By
+varying the saturation momentum of the target and the projectile, we establish
+the regime of validity of the dilute-dense approximation and assess the
+magnitude and basic features of higher order saturation corrections. In
+particular, we find that dilute-dense approximation faithfully reproduces
+dense-dense results if restricted to the range of its validity.",1910.12496v1
+2019-11-20,Flexural Fatigue Life of Woven Carbon/Vinyl Ester Composites under Sea Water Saturation,"The adverse effects of sea water environment on the fatigue life of woven
+carbon fiber/vinyl ester composites are established at room temperature in view
+of long-term survivability of offshore structures. It is observed that the
+influence of sea water saturation on the fatigue life is more pronounced when
+the maximum cyclic displacement approaches maximum quasi-static deflection,
+that is, the reduction in the number of cycles to failure are comparable
+between dry and sea water saturated samples at lower strain ranges (~37% at
+0.46% strain), but are drastically different at higher strain ranges (~90% at
+0.62% strain). Key damage modes that manifest during the fatigue loading is
+also identified, and a non-linear model is established for predicting low cycle
+fatigue life of these composites in dry and sea water saturated conditions.",1911.08665v2
+2019-11-20,Drift velocity saturation and large current density in an intrinsic three-dimensional Dirac semimetal cadmium arsenide,"Transport of electrons at high electric fields is investigated in an
+intrinsic three-dimensional Dirac semimetal cadmium arsenide, considering the
+scattering of electrons from acoustic and optical phonons. Screening and hot
+phonon effect are taken in to account. Expressions for the hot electron
+mobility $\mu$ and power loss $P$ are obtained as a function of electron
+temperature $T_e$. The dependence of drift velocity $v_d$ on electric field $E$
+and electron density $n_e$ has been studied. Hot phonon effect is found to set
+in the saturation of $v_d$ at relatively low $E$ and significantly degrades its
+magnitude. The drift velocity is found to saturate at a value $v_{ds} \sim
+10^7$ cm/s and it is weakly dependent on $n_e$. A large saturation current
+density $\sim 10^6$ A/cm$^2$ is predicted.",1911.08965v1
+2019-11-25,Optimizing Josephson-Ring-Modulator-based Josephson Parametric Amplifiers via full Hamiltonian control,"Josephson Parametric Amplifiers (JPA) are nonlinear devices that are used for
+quantum sensing and qubit readout in the microwave regime. While JPAs regularly
+operate in the quantum limit, their gain saturates for very small (few photons)
+input power. In a previous work, we showed that the saturation power of JPAs is
+not limited by pump depletion, but instead by the high-order nonlinearity of
+Josephson junctions, the nonlinear circuit elements that enable amplification
+in JPAs. Here, we present a systematic study of the nonlinearities in JPAs, we
+show which nonlinearities limit the saturation power, and present a strategy
+for optimizing the circuit parameters for achieving the best possible JPA. For
+concreteness, we focus on JPAs that are constructed around a Josephson Ring
+Modulator (JRM). We show that by tuning the external and shunt inductors, we
+should be able to take the best experimentally available JPAs and improve their
+saturation power by $\sim 15$ dB. Finally, we argue that our methods and
+qualitative results are applicable to a broad range of cavity based JPAs.",1911.11176v3
+2019-11-26,On grouops with formational subnormal or self-normalizing subgroups,"We establish the structure of finite groups with $\mathfrak{F}$-subnormal or
+self-normalizing primary cyclic subgroups in case $\mathfrak{F}$ is a
+subgroup-closed saturated superradical formation containing all nilpotent
+groups.",1911.11648v1
+2019-12-18,Saturation of radiative heat transfer due to many-body thermalization,"Radiative heat transfer between two bodies saturates at very short separation
+distances due to the nonlocal optical response of the materials. In this work,
+we show that the presence of radiative interactions with a third body or
+external bath can also induce a saturation of the heat transfer, even at
+separation distances for which the optical response of the materials is purely
+local. We demonstrate that this saturation mechanism is a direct consequence of
+a thermalization process resulting from many-body interactions in the system.
+This effect could have an important impact in the field of nanoscale thermal
+management of complex systems and in the interpretation of measured signals in
+thermal metrology at the nanoscale.",1912.08515v1
+2020-03-03,Algorithms for fusion systems with applications to $p$-groups of small order,"For a prime $p$, we describe a protocol for handling a specific type of
+fusion system on a $p$-group by computer. These fusion systems contain all
+saturated fusion systems. This framework allows us to computationally determine
+whether or not two subgroups are conjugate in the fusion system for example. We
+describe a generation procedure for automizers of every subgroup of the
+$p$-group. This allows a computational check of saturation. These procedures
+have been implemented using MAGMA. We describe a program to search for
+saturated fusion systems $\mathcal{F}$ on $p$-groups with $O_p(\mathcal{F})=1$
+and $O^p(\mathcal{F})=\mathcal{F}$. Employing these computational methods we
+determine all such fusion system on groups of order $p^n$ where $(p,n) \in
+\{(3,4),(3,5),(3,6),(3,7),(5,4),(5,5),(5,6),(7,4),(7,5)\}$. This gives the
+first complete picture of which groups can support saturated fusion systems on
+small $p$-groups of odd order.",2003.01600v4
+2020-03-11,Entropy Bound and Unitarity of Scattering Amplitudes,"We establish that unitarity of scattering amplitudes imposes universal
+entropy bounds. The maximal entropy of a self-sustained quantum field object of
+radius R is equal to its surface area and at the same time to the inverse
+running coupling evaluated at the scale R. The saturation of these entropy
+bounds is in one-to-one correspondence with the non-perturbative saturation of
+unitarity by 2-to-N particle scattering amplitudes at the point of optimal
+truncation. These bounds are more stringent than Bekenstein's bound and in a
+consistent theory all three get saturated simultaneously. This is true for all
+known entropy-saturating objects such as solitons, instantons, baryons,
+oscillons, black holes or simply lumps of classical fields. We refer to these
+collectively as ""saturons"" and show that in renormalizable theories they behave
+in all other respects like black holes. Finally, it is argued that the
+confinement in SU(N) gauge theory can be understood as a direct consequence of
+the entropy bounds and unitarity.",2003.05546v1
+2020-04-11,"A lower bound on the saturation number, and graphs for which it is sharp","Let $H$ be a fixed graph. We say that a graph $G$ is $H$-saturated if it has
+no subgraph isomorphic to $H$, but the addition of any edge to $G$ results in
+an $H$-subgraph. The saturation number $\mathrm{sat}(H,n)$ is the minimum
+number of edges in an $H$-saturated graph on $n$ vertices. K\'aszonyi and Tuza,
+in 1986, gave a general upper bound on the saturation number of a graph $H$,
+but a nontrivial lower bound has remained elusive. In this paper we give a
+general lower bound on $\mathrm{sat}(H,n)$ and prove that it is asymptotically
+sharp (up to an additive constant) on a large class of graphs. This class
+includes all threshold graphs and many graphs for which the saturation number
+was previously determined exactly. Our work thus gives an asymptotic common
+generalization of several earlier results. The class also includes disjoint
+unions of cliques, allowing us to address an open problem of Faudree, Ferrara,
+Gould, and Jacobson.",2004.05410v2
+2020-04-13,"Saturation problems in the Ramsey theory of graphs, posets and point sets","In 1964, Erd\H{o}s, Hajnal and Moon introduced a saturation version of
+Tur\'an's classical theorem in extremal graph theory. In particular, they
+determined the minimum number of edges in a $K_r$-free, $n$-vertex graph with
+the property that the addition of any further edge yields a copy of $K_r$. We
+consider analogues of this problem in other settings. We prove a saturation
+version of the Erd\H{o}s-Szekeres theorem about monotone subsequences and
+saturation versions of some Ramsey-type theorems on graphs and Dilworth-type
+theorems on posets.
+  We also consider semisaturation problems, wherein we allow the family to have
+the forbidden configuration, but insist that any addition to the family yields
+a new copy of the forbidden configuration. In this setting, we prove a
+semisaturation version of the Erd\H{o}s-Szekeres theorem on convex $k$-gons, as
+well as multiple semisaturation theorems for sequences and posets.",2004.06097v2
+2020-07-21,Narrow bandwidth Q-switched Erbium-doped fiber laser based on dynamic saturable absorption filtering effect,"We proposed a narrow spectral bandwidth Erbium-doped fiber (EDF) laser
+Q-switched by a homemade saturable dynamic induced grating (SDIG) which is
+introduced via reforming the structure of a fiber saturable absorbers FSA with
+a piece of EDF and a fiber Bragg grating. The SDIG integrates both saturable
+absorption and spectral filtering effect simultaneously, which was confirmed
+through theoretical analysis and experimental results for the first time, to
+the best of our knowledge. Further study verified that the spectral width of
+the Q-switched emissions is decided by the length of the SDIG and the input
+power of the pump source. The Q-switched pulse with the narrowest spectral
+width of about 29.1 pm achieved in this work is the narrowest bandwidth pulse
+in the domain of the FSA Q-switched fiber lasers when the length of SDIG and
+pump power are 20 cm and 250 mW, respectively. Our method provides a simple way
+to obtain the Q-switched pulses with narrow bandwidths, which have promising
+applications for nonlinear frequency conversion, Doppler LIDAR and coherent
+beam combinations.",2007.10583v1
+2020-07-21,Models of Jacobians of curves,"We show that the Jacobians of prestable curves over toroidal varieties always
+admit N\'eron models. These models are rarely quasi-compact or separated, but
+we also give a complete classification of quasi-compact separated group-models
+of such Jacobians. In particular we show the existence of a maximal
+quasi-compact separated group model, which we call the saturated model, which
+has the extension property for all torsion sections. The N\'eron model and the
+saturated model coincide over a Dedekind base, so the saturated model gives an
+alternative generalisation of the classical notion of N\'eron models to
+higher-dimensional bases; in the general case we give necessary and sufficient
+conditions for the N\'eron model and saturated model to coincide. The key
+result, from which most others descend, is that the logarithmic Jacobian of
+\cite{Molcho2018The-logarithmic} is a log Neron model of the Jacobian.",2007.10792v1
+2020-09-14,Accelerated Nonlinear Model Predictive Control by Exploiting Saturation,"We present an approach for accelerating nonlinear model predictive control.
+If the current optimal input signal is saturated, also the optimal signals in
+subsequent time steps often are. We propose to use the open-loop optimal input
+signals whenever the first and some subsequent input signals are saturated. We
+only solve the next optimal control problem, when a non-saturated signal is
+encountered, or the end of the horizon is reached. In this way, we can save a
+significant number of NLPs to be solved while on the other hand keep the
+performance loss small. Furthermore, the NMPC is reactivated in time when it
+comes to controlling the system safely to its reference.",2009.06347v1
+2020-09-20,Correction Method for the Readout Saturation of the DAMPE Calorimeter,"The DArk Matter Particle Explorer (DAMPE) is a space-borne high energy
+cosmic-ray and $\gamma$-ray detector which operates smoothly since the launch
+on December 17, 2015. The bismuth germanium oxide (BGO) calorimeter is one of
+the key sub-detectors of DAMPE used for energy measurement and electron proton
+identification. For events with total energy deposit higher than decades of
+TeV, the readouts of PMTs coupled on the BGO crystals would become saturated,
+which results in an underestimation of the energy measurement. Based on
+detailed simulations, we develop a correction method for the saturation effect
+according to the shower development topologies and energies measured by
+neighbouring BGO crystals. The verification with simulated and on-orbit events
+shows that this method can well reconstruct the energy deposit in the saturated
+BGO crystal.",2009.09438v1
+2020-10-05,Sample weighting as an explanation for mode collapse in generative adversarial networks,"Generative adversarial networks were introduced with a logistic MiniMax cost
+formulation, which normally fails to train due to saturation, and a
+Non-Saturating reformulation. While addressing the saturation problem, NS-GAN
+also inverts the generator's sample weighting, implicitly shifting emphasis
+from higher-scoring to lower-scoring samples when updating parameters. We
+present both theory and empirical results suggesting that this makes NS-GAN
+prone to mode dropping. We design MM-nsat, which preserves MM-GAN sample
+weighting while avoiding saturation by rescaling the MM-GAN minibatch gradient
+such that its magnitude approximates NS-GAN's gradient magnitude. MM-nsat has
+qualitatively different training dynamics, and on MNIST and CIFAR-10 it is
+stronger in terms of mode coverage, stability and FID. While the empirical
+results for MM-nsat are promising and favorable also in comparison with the
+LS-GAN and Hinge-GAN formulations, our main contribution is to show how and why
+NS-GAN's sample weighting causes mode dropping and training collapse.",2010.02035v1
+2020-10-06,Multi-Rees algebras on principal ideal rings,"When $R$ is a Noetherian ring and we have a family of ideals in which every
+ideal contains at least one nonzero divisor, then it is already known that the
+defining ideal of the multi-Rees algebra of these ideals is equal to a
+saturated ideal. In such a case to get the defining ideal of the multi-Rees
+algebra we only need to saturate the first syzygies of direct sum of this
+family of ideals. However, this fact is not true, when at least one of these
+ideals does not contain any nonzero divisor. In this paper we show that the
+defining ideal of the multi-Rees algebra of a family of ideals of a polynomial
+ring over a principal ideal ring, is equal to another kind of saturated ideal,
+where we saturate more explicit polynomials other than just first syzygies.
+Please notice that in general some of these ideals may not contain nonzero
+divisors. Given this explicit formula, we can compute Gr\""{o}bner basis of the
+defining ideal using an elimination order, which we talk about in the present
+paper.",2010.02899v2
+2020-10-28,Receptor Saturation Modeling for Synaptic DMC,"Synaptic communication is a natural Molecular Communication (MC) system which
+may serve as a blueprint for the design of synthetic MC systems. In particular,
+it features highly specialized mechanisms to enable inter-symbol interference
+(ISI)-free and energy efficient communication. The understanding of synaptic MC
+is furthermore critical for disruptive innovations in the context of
+brain-machine interfaces. However, the physical modeling of synaptic MC is
+complicated by the possible saturation of the molecular receiver arising from
+the competition of postsynaptic receptors for neurotransmitters. Saturation
+renders the system behavior nonlinear and is commonly neglected in existing
+analytical models. In this work, we propose a novel model for receptor
+saturation in terms of a nonlinear, state-dependent boundary condition for
+Fick's diffusion equation. We solve the resulting boundary-value problem using
+an eigenfunction expansion of the Laplace operator and the incorporation of the
+receiver memory as feedback system into the corresponding state-space
+description. The presented solution is numerically stable and computationally
+efficient. Furthermore, the proposed model is validated with particle-based
+stochastic computer simulations.",2010.14828v2
+2020-11-06,Geometric conditions for saturating the data processing inequality,"The data processing inequality (DPI) is a scalar inequality satisfied by
+distinguishability measures on density matrices. For some distinguishability
+measures, saturation of the scalar DPI implies an operator equation relating
+the arguments of the measure. These results are typically derived using
+functional analytic techniques. In a complementary approach, we use geometric
+techniques to derive a formula that gives an operator equation from DPI
+saturation for any distinguishability measure; moreover, for a broad class of
+distinguishability measures, the derived operator equation is sufficient to
+imply saturation as well. Our operator equation coincides with known results
+for the sandwiched R\'{e}nyi relative entropies, and gives new results for
+$\alpha$-$z$ R\'{e}nyi relative entropies and a family of of quantum
+$f$-divergences, which we compute explicitly.",2011.03473v2
+2020-11-09,A type of shadowing and distributional chaos,"For any continuous self-map of a compact metric space, we prove a saturation
+of distributionally scrambled Mycielski sets under a type of shadowing and the
+chain transitivity.",2011.04248v1
+2020-11-20,Deep unfolding-based output feedback control design for linear systems with input saturation,"In this paper, we propose a deep unfolding-based framework for the output
+feedback control of systems with input saturation. Although saturation commonly
+arises in several practical control systems, there is still a scarce of
+effective design methodologies that can directly deal with the severe
+non-linearity of the saturation operator. In this paper, we aim to design an
+anti-windup controller for enlarging the region of stability of the closed-loop
+system by learning from the numerical simulations of the closed-loop system.
+The data-driven framework we propose in this paper is based on a deep-learning
+technique called Neural Ordinary Differential Equations. Within our framework,
+we first obtain a candidate controller by using the deep-learning technique,
+which is then tested by the existing theoretical results already established in
+the literature, thereby avoiding the computational challenge in the
+conventional design methodologies as well as theoretically guaranteeing the
+performance of the system. Our numerical simulation shows that the proposed
+framework can significantly outperform a conventional design methodology based
+on linear matrix inequalities.",2011.10196v2
+2020-12-03,Saturated $k$-Plane Drawings with Few Edges,"A drawing of a graph is $k$-plane if no edge is crossed more than $k$ times.
+In this paper we study saturated $k$-plane drawings with few edges. This are
+$k$-plane drawings in which no edge can be added without violating
+$k$-planarity. For every number of vertices $n>k+1$, we present a tight
+construction with $\frac{n-1}{k+1}$ edges for the case in which the edges can
+self-intersect. If we restrict the drawings to be $\ell$-simple we show that
+the number of edges in saturated $k$-plane drawings must be higher. We present
+constructions with few edges for different values of $k$ and $\ell$. Finally,
+we investigate saturated straight-line $k$-plane drawings.",2012.02281v4
+2020-12-20,Robust Alignment of Multi-Exposed Images with Saturated Regions,"It is challenging to align multi-exposed images due to large illumination
+variations, especially in presence of saturated regions. In this paper, a novel
+image alignment algorithm is proposed to cope with the multi-exposed images
+with saturated regions. Specifically, the multi-exposed images are first
+normalized by using intensity mapping functions (IMFs) in consideration of
+saturated pixels. Then, the normalized images are coded by using the local
+binary pattern (LBP). Finally, the coded images are aligned by formulating an
+optimization problem by using a differentiable Hamming distance. Experimental
+results show that the proposed algorithm outperforms state-of-the-art alignment
+methods for multi-exposed images in terms of alignment accuracy and robustness
+to exposure values.",2012.10872v1
+2021-03-14,Sharp transition to strongly anomalous transport in unsaturated porous media,"The simultaneous presence of liquid and gas in porous media increases flow
+heterogeneity compared to saturated flows. However, so far the impact of
+saturation on flow statistics and transport dynamics remained unclear. Here, we
+develop a theoretical framework that captures the impact of flow reorganization
+on the statistics of pore-scale fluid velocities, due to the presence of gas in
+the pore space, which leads to the development of a highly-structured flow
+field. Preferential flow is distributed spatially through the denoted backbone
+and flow recirculation occurs in dead-end regions branching from it. This
+induces a marked change in the scaling of the velocity PDF compared to the
+saturated case, and a sharp transition to strongly anomalous transport. We
+develop a transport model based on the continuous time random walk theory that
+successfully predicts advective transport dynamics for all saturation degrees.
+Our results provide a new modelling framework linking phase heterogeneity to
+flow heterogeneity and to transport in unsaturated media.",2103.08016v1
+2021-03-23,A stabilized computational nonlocal poromechanics model for dynamic analysis of saturated porous media,"In this article we formulate a stable computational nonlocal poromechanics
+model for dynamic analysis of saturated porous media. As a novelty, the
+stabilization formulation eliminates zero-energy modes associated with the
+original multiphase correspondence constitutive models in the coupled nonlocal
+poromechanics model. The two-phase stabilization scheme is formulated based on
+an energy method that incorporates inhomogeneous solid deformation and fluid
+flow. In this method, the nonlocal formulations of skeleton strain energy and
+fluid flow dissipation energy equate to their local formulations. The stable
+coupled nonlocal poromechanics model is solved for dynamic analysis by an
+implicit time integration scheme. As a new contribution, we validate the
+coupled stabilization formulation by comparing numerical results with
+analytical and finite element solutions for one-dimensional and two-dimensional
+dynamic problems in saturated porous media. Numerical examples of dynamic
+strain localization in saturated porous media are presented to demonstrate the
+efficacy of the stable coupled poromechanics framework for localized failure
+under dynamic loads.",2103.12259v1
+2021-03-30,Local output feedback stabilization of a Reaction-Diffusion equation with saturated actuation,"This paper is concerned with the output feedback stabilization of a
+reaction-diffusion equation by means of bounded control inputs in the presence
+of saturations. Using a finite-dimensional controller composed of an observer
+coupled with a finite-dimensional state-feedback, we derive a set of conditions
+ensuring the stability of the closed-loop plant while estimating the associated
+domain of attraction in the presence of saturations. This set of conditions is
+shown to be always feasible for an order of the observer selected large enough.
+The stability analysis relies on Lyapunov functionals along with a generalized
+sector condition classically used to study the stability of linear
+finite-dimensional plants in the presence of saturations.",2103.16523v2
+2021-06-25,Training Saturation in Layerwise Quantum Approximate Optimisation,"Quantum Approximate Optimisation (QAOA) is the most studied gate based
+variational quantum algorithm today. We train QAOA one layer at a time to
+maximize overlap with an $n$ qubit target state. Doing so we discovered that
+such training always saturates -- called \textit{training saturation} -- at
+some depth $p^*$, meaning that past a certain depth, overlap can not be
+improved by adding subsequent layers. We formulate necessary conditions for
+saturation. Numerically, we find layerwise QAOA reaches its maximum overlap at
+depth $p^*=n$. The addition of coherent dephasing errors to training removes
+saturation, recovering robustness to layerwise training. This study sheds new
+light on the performance limitations and prospects of QAOA.",2106.13814v1
+2021-06-30,Saturated Transformers are Constant-Depth Threshold Circuits,"Transformers have become a standard neural network architecture for many NLP
+problems, motivating theoretical analysis of their power in terms of formal
+languages. Recent work has shown that transformers with hard attention are
+quite limited in power (Hahn, 2020), as they can be simulated by constant-depth
+AND/OR circuits (Hao et al. 2021). However, hard attention is a strong
+assumption, which may complicate the relevance of these results in practice. In
+this work, we analyze the circuit complexity of transformers with saturated
+attention: a generalization of hard attention that more closely captures the
+attention patterns learnable in practical transformers. We first show that
+saturated transformers transcend the known limitations of hard-attention
+transformers. We then prove saturated transformers with floating-point values
+can be simulated by constant-depth threshold circuits, giving the class
+$\mathsf{TC}^0$ as an upper bound on the formal languages they recognize.",2106.16213v3
+2021-07-20,Does vacuum saturation work for the higher dimensional vacuum condensates in the QCD sum rules?,"In the QCD sum rules for the tetraquark (molecular) states, the higher
+dimensional vacuum condensates play an important role in extracting the
+tetraquark masses. We carry out the operator product expansion up to the vacuum
+condensates of dimension-10 and observe that the vacuum condensates of
+dimensions $6$, $8$ and $10$ have the same expressions but opposite signs for
+the $C\gamma_5\otimes \gamma_\mu C$-type and $C\otimes \gamma_\mu C$ type
+four-quark currents, which make their influences distinguishable, and they are
+excellent channels to examine the vacuum saturation approximation. We introduce
+a parameter $\kappa$ to parameterize the derivation from the vacuum saturation
+or factorization approximation, and choose two sets parameters to examine the
+influences on the predicted tetraquark masses, which can be confronted to the
+experimental data in the future. In all the channels, smaller value of the
+$\kappa$ leads to better convergent behavior in the operator product expansion,
+which favors the vacuum saturation approximation.",2107.09328v2
+2021-07-20,Fourth-order moment of the light field in atmosphere for moderate and strong turbulence,"Collisionless Boltzmann equation is used to describe the intensity
+correlations in partially saturated and fully saturated regimes in terms of
+photon distribution function in the phase space. Explicit expression for fourth
+moment of the light fields is obtained for the case of moderate and strong
+turbulence. Such expression consists of two terms accounting for two regions in
+the phase space that independently contribute to the correlation function. It
+is shown that present solution agrees with previous results for fully saturated
+regime. Additionally it embodies the effect of partially saturated radiation
+where the correlations of photon trajectories are important and the magnitude
+of the scintillation index is well above the unity. Fourth moment is used to
+study the fluctuations of transmittance which consider the effect of finite
+detector aperture.",2107.09358v1
+2021-08-06,Sub-barrier quantum tunneling: eliminating the MacColl-Hartman paradox,"I show that the MacColl-Hartman effect, namely, the saturation of the group
+delay time of sub-barrier quantum tunneling as a function of the barrier width,
+comes from the saturating behavior of a more fundamental concept - the phase of
+the stationary wave function. The explanation of saturation is given based on
+the decomposition of the stationary wave function into the spectrum of wave
+numbers and formulation of the initial condition for the direction of
+propagation of the incident matter wave. It is also shown that the saturation
+plateau of MacColl and Hartman actually doesn't continue indefinitely, but has
+a finite length. After the plateau, the sub-barrier tunneling time
+monotonically increases with increasing width of the potential, and this
+applies both to the maximum's of the wave packet and to the average tunneling
+time.",2108.03054v1
+2021-10-26,Event-triggered Consensus of Matrix-weighted Networks Subject to Actuator Saturation,"The ubiquitous interdependencies among higher-dimensional states of
+neighboring agents can be characterized by matrix-weighted networks. This paper
+examines event-triggered global consensus of matrix-weighted networks subject
+to actuator saturation. Specifically, a distributed dynamic event-triggered
+coordination strategy, whose design involves sampled state of agents,
+saturation constraint and auxiliary systems, is proposed for this category of
+generalized network to guarantee its global consensus. Under the proposed
+event-triggered coordination strategy, sufficient conditions are derived to
+guarantee the leaderless and leader-follower global consensus of the
+multi-agent systems on matrix-weighted networks, respectively. The Zeno
+phenomenon can be excluded for both cases under the proposed coordination
+strategy. It turns out that the spectral properties of matrix-valued weights
+are crucial in event-triggered mechanism design for matrix-weighted networks
+with actuator saturation constraint. Finally, simulations are provided to
+demonstrate the effectiveness of proposed event-triggered coordination
+strategy. This work provides a more general design framework compared with
+existing results that are only applicable to scalar-weighted networks.",2110.13356v1
+2021-11-09,Generation and dynamics of soliton and soliton molecules from a VSe2/GO-based fiber laser,"Recently, in addition to exploring the application of new saturable absorber
+devices in fiber lasers, soliton dynamics has also become a focus of current
+research. In this article, we report an ultrashort pulse fiber laser based on
+VSe2/GO nanocomposite and verify the formation process of soliton and soliton
+molecules by the numerical simulation. The prepared VSe2/GO-based device shows
+excellent saturable absorption characteristics with a modulation depth of 14.3%
+and a saturation absorption intensity of 0.93MW/cm2. The conventional soliton
+is obtained with pulse width of 573fs, which is currently the narrowest pulse
+width based on VSe2-related material, and has a signal-to-noise ratio of 60.4
+dB. In addition, the soliton molecules are realized based on the VSe2/GO for
+the first time and have a pulse interval of ~2.2ps. We study the soliton
+dynamics through numerical simulation and reveal that before the formation of
+the soliton, it undergoes multiple nonlinear stages, such as soliton
+mode-locking, soliton splitting, and soliton oscillation. Furthermore, the
+results of numerical simulation are agreed well with the experimental data.
+These results indicate that the VSe2/GO might be another promising saturable
+absorber material for ultrafast photonics, and deepen the understanding of
+soliton dynamics in ultrafast fiber lasers.",2111.05138v1
+2021-11-11,Hybrid Saturation Restoration for LDR Images of HDR Scenes,"There are shadow and highlight regions in a low dynamic range (LDR) image
+which is captured from a high dynamic range (HDR) scene. It is an ill-posed
+problem to restore the saturated regions of the LDR image. In this paper, the
+saturated regions of the LDR image are restored by fusing model-based and
+data-driven approaches. With such a neural augmentation, two synthetic LDR
+images are first generated from the underlying LDR image via the model-based
+approach. One is brighter than the input image to restore the shadow regions
+and the other is darker than the input image to restore the high-light regions.
+Both synthetic images are then refined via a novel exposedness aware saturation
+restoration network (EASRN). Finally, the two synthetic images and the input
+image are combined together via an HDR synthesis algorithm or a multi-scale
+exposure fusion algorithm. The proposed algorithm can be embedded in any smart
+phones or digital cameras to produce an information-enriched LDR image.",2111.06038v2
+2021-12-12,Probing parton saturation and the gluon dipole via diffractive jet production at the Electron-Ion Collider,"We demonstrate that hard dijet production via coherent inelastic diffraction
+is a promising channel for probing gluon saturation at the Electron-Ion
+Collider. By $inelastic$ diffraction we mean a process in which the two hard
+jets - a quark-antiquark pair generated by the decay of the virtual photon -
+are accompanied by a softer gluon jet, emitted by the quark or the antiquark.
+This process can be described as the elastic scattering of an effective
+gluon-gluon dipole. The cross section takes a factorised form, between a hard
+factor and a unintegrated (""Pomeron"") gluon distribution describing the
+transverse momentum imbalance between the hard dijets. The dominant
+contribution comes from the black disk limit and leads to a dijet imbalance of
+the order of the target saturation momentum $Q_s$ evaluated at the rapidity
+gap. Integrating out the dijet imbalance, we obtain a collinear factorization
+where the initial condition for the DGLAP evolution is set by gluon saturation.",2112.06353v2
+2021-12-29,Finitely generated saturated multi-Rees algebras,"We study the question of finite generation of saturated multi-Rees algebras
+and investigate the asymptotic behaviour of related length functions. In the
+setup of excellent local domains, we show that the saturated multi-Rees algebra
+of a finite collection of ideals is finitely generated when the analytic spread
+is not maximal and the associated length function eventually agrees with a
+polynomial. Similar results are obtained when we restrict to two-dimensional
+local UFDs with no restrictions on the analytic spread. We further prove that
+the saturated multi-Rees algebra of finitely many monomial ideals in a
+polynomial ring modulo an irreducible monomial ideal, is always finitely
+generated. In this case, the corresponding length function is shown to exhibit
+piecewise quasi-polynomial behaviour. We also produce multi-ideal versions of a
+theorem of Amao.",2112.14587v2
+2022-01-05,Nuclei in the toy world: beyond the Pomeron in zero transverse dimensions,"We explore possible extensions of the $t$-channel and $s$-channel unitary
+model of high energy evolution in zero transverse dimensions appropriate to
+very high energy/atomic number where the dipole density in a toy hadron is
+parametrically high.We suggest that the appropriate generalization is to allow
+emission of more than one dipole in a single step of energy evolution. We
+construct explicitly such a model that preserves the $t$-channel and s-channel
+unitarity and have the correct low density limit, and study the particle
+multiplicity distribution resulting from this evolution. We consider initial
+conditions of a single dipole and many dipoles at initial rapidity. We observe
+that the saturation regime in this model is preceded by a parametric range of
+rapidities
+$\frac{1}{\alpha_s}\ln\frac{1}{\alpha_s}<Y<\frac{1}{\alpha_s}\ln\frac{1}{\alpha_s^2}$,
+where the saturation effects are still unimportant, but multiple emissions
+determine the properties of the evolution. We also discuss the influence of the
+saturation on the parton cascade and, in particular, find that in the
+saturation regime the entropy of partons becomes $S \approx \h \ln N$ where $N$
+is the mean multiplicity.",2201.01551v2
+2022-03-09,Mapping global dynamics of benchmark creation and saturation in artificial intelligence,"Benchmarks are crucial to measuring and steering progress in artificial
+intelligence (AI). However, recent studies raised concerns over the state of AI
+benchmarking, reporting issues such as benchmark overfitting, benchmark
+saturation and increasing centralization of benchmark dataset creation. To
+facilitate monitoring of the health of the AI benchmarking ecosystem, we
+introduce methodologies for creating condensed maps of the global dynamics of
+benchmark creation and saturation. We curated data for 3765 benchmarks covering
+the entire domains of computer vision and natural language processing, and show
+that a large fraction of benchmarks quickly trended towards near-saturation,
+that many benchmarks fail to find widespread utilization, and that benchmark
+performance gains for different AI tasks were prone to unforeseen bursts. We
+analyze attributes associated with benchmark popularity, and conclude that
+future benchmarks should emphasize versatility, breadth and real-world utility.",2203.04592v4
+2022-05-10,Balanced control between performance and saturation for constrained nonlinear systems,"This paper addresses the balanced control between performance and saturation
+for a class of constrained nonlinear systems, including the branches: balanced
+command filtered backstepping (BCFB) and balanced performance control (BPC). To
+balance the interconnection and conflict between performance and saturation
+constraints, define a performance safety evaluation (PSE) function, which
+evaluates the system safety under the destabilizing effect variables (DEVs)
+like saturation quantity and filter errors, then the cumulative effects of DEVs
+are fully utilized and compensated for the performance recovery. Specifically,
+there exists some degree of tolerance for the DEVs in the safety region, and
+the compensation operation works when the evaluation of the system goes
+dangerous. The advantages of the proposed methodology are illustrated in the
+numerical simulation.",2205.04674v1
+2022-06-10,The Z3RO Family of Precoders Cancelling Nonlinear Power Amplification Distortion in Large Array Systems,"Large array systems use a massive number of antenna elements and clever
+precoder designs to achieve an array gain at the user location. These precoders
+require linear front-ends, and more specifically linear power amplifiers (PAs),
+to avoid distortion. This reduces the energy efficiency since PAs are most
+efficient close to saturation, where they generate most nonlinear distortion.
+Moreover, the use of conventional precoders can induce a coherent combining of
+distortion at the user locations, degrading the signal quality. In this work,
+novel linear precoders, simple to compute and to implement, are proposed that
+allow working close to saturation, while cancelling the third-order
+nonlinearity of the PA without prior knowledge of the signal statistics and PA
+model. Their design consists in saturating a single or a few antennas on
+purpose together with an negative gain with respect to all other antennas to
+compensate for the overall nonlinear distortion at the user location. The
+performance gains of the designs are significant for PAs working close to
+saturation, as compared to maximum ratio transmission (MRT) precoding and
+perfect per-antenna digital pre-distortion (DPD) compensation.",2206.05112v1
+2022-07-08,Nuclear geometry at high energy from exclusive vector meson production,"We show that when saturation effects are included one obtains a good
+description of the exclusive $\mathrm{J}/\psi$ production spectra in ultra
+peripheral lead-lead collisions as recently measured by the ALICE Collaboration
+at the LHC. As exclusive spectra are sensitive to the spatial distribution of
+nuclear matter at small Bjorken-$x$, this implies that gluon saturation effects
+modify the impact parameter profile of the target as we move towards small $x$.
+In addition to saturation effects, we find a preference for larger nuclear
+strong-interaction radii compared to the typical charge radius. We demonstrate
+the role of finite photon transverse momentum and the interference between the
+cases for which the role of photon emitter and target are switched between the
+nuclei. We show that these effects are comparable to the experimental precision
+for $p_T$-differential cross sections and as such need to be included when
+comparing to LHC data. Finally, the integrated $\mathrm{J}/\psi$ production
+cross sections from the LHC and preliminary transverse momentum spectra from
+RHIC are shown to prefer calculations with fluctuating nucleon substructure,
+although these datasets would require even stronger saturation effects than
+predicted from our framework.",2207.03712v1
+2022-07-27,The onset and saturation of the Faraday instability in miscible fluids in a rotating environment,"We investigate the influence of rotation on the onset and saturation of the
+Faraday instability in a vertically oscillating two-layer miscible fluid using
+a theoretical model and direct numerical simulations (DNS). Our analytical
+approach utilizes the Floquet analysis to solve a set of the Mathieu equations
+obtained from the linear stability analysis. The solution of the Mathieu
+equations comprises stable and harmonic, and sub-harmonic unstable regions in a
+three-dimensional stability diagram. We find that the Coriolis force stabilizes
+the flow and delays the onset of the sub-harmonic instability responsible for
+turbulent mixing at lower forcing amplitudes. However, at higher forcing
+amplitudes, the flow is energetic enough to mitigate the stabilizing effect of
+rotation, and the evolution of the turbulent mixing zone is similar in both
+rotating and non-rotating environments. These results are corroborated by DNS
+at different Coriolis frequencies and forcing amplitudes. We also observe that
+for $\left(f/\omega\right)^2<0.25$, where $f$ is the Coriolis frequency, and
+$\omega$ is the forcing frequency, the instability, and the turbulent mixing
+zone size-$L$ saturates. When $\left(f/\omega\right)^2\geq0.25$, the turbulent
+mixing zone size-$L$ never saturates and continues to grow.",2207.13739v1
+2022-08-04,Estimating relative diffusion from 3D micro-CT images using CNNs,"In the past several years, convolutional neural networks (CNNs) have proven
+their capability to predict characteristic quantities in porous media research
+directly from pore-space geometries. Due to the frequently observed significant
+reduction in computation time in comparison to classical computational methods,
+bulk parameter prediction via CNNs is especially compelling, e.g. for effective
+diffusion. While the current literature is mainly focused on fully saturated
+porous media, the partially saturated case is also of high interest. Due to the
+qualitatively different and more complex geometries of the domain available for
+diffusive transport present in this case, standard CNNs tend to lose robustness
+and accuracy with lower saturation rates. In this paper, we demonstrate the
+ability of CNNs to perform predictions of relative diffusion directly from full
+pore-space geometries. As such, our CNN conveniently fuses diffusion prediction
+and a well-established morphological model which describes phase distributions
+in partially saturated porous media.",2208.03337v1
+2022-10-04,Fast Saturating Gate for Learning Long Time Scales with Recurrent Neural Networks,"Gate functions in recurrent models, such as an LSTM and GRU, play a central
+role in learning various time scales in modeling time series data by using a
+bounded activation function. However, it is difficult to train gates to capture
+extremely long time scales due to gradient vanishing of the bounded function
+for large inputs, which is known as the saturation problem. We closely analyze
+the relation between saturation of the gate function and efficiency of the
+training. We prove that the gradient vanishing of the gate function can be
+mitigated by accelerating the convergence of the saturating function, i.e.,
+making the output of the function converge to 0 or 1 faster. Based on the
+analysis results, we propose a gate function called fast gate that has a doubly
+exponential convergence rate with respect to inputs by simple function
+composition. We empirically show that our method outperforms previous methods
+in accuracy and computational efficiency on benchmark tasks involving extremely
+long time scales.",2210.01348v1
+2023-03-23,Intra-Pulse Intensity Noise Shaping by Saturable Absorbers,"In this work, we identify and characterize intra-pulse intensity noise
+shaping by saturable absorbers applied in mode-locked lasers and ultra-low
+noise nonlinear fiber amplifiers. Reshaped intra-pulse intensity noise
+distributions are shown to be inevitably interconnected with self-amplitude
+modulation, the fundamental physical mechanism for initiation and stabilization
+of ultra-short pulses in the steady-state of a mode-locked laser. A theoretical
+model is used to describe the ultrafast saturation dynamics by an intra-pulse
+noise transfer function for widely-applied slow and fast saturable absorbers.
+For experimental verification of the theoretical results, spectrally-resolved
+relative intensity noise measurements are applied on chirped input pulses to
+enable the direct measurement of intra-pulse noise transfer functions using a
+versatile experimental platform. It is further demonstrated, how the
+characterized intra-pulse intensity noise distribution of ultrafast laser
+systems can be utilized for quantum-limited intensity noise suppression via
+tailored optical bandpass filtering.",2303.13420v2
+2023-04-24,Adaptive-saturated RNN: Remember more with less instability,"Orthogonal parameterization is a compelling solution to the vanishing
+gradient problem (VGP) in recurrent neural networks (RNNs). With orthogonal
+parameters and non-saturated activation functions, gradients in such models are
+constrained to unit norms. On the other hand, although the traditional vanilla
+RNNs are seen to have higher memory capacity, they suffer from the VGP and
+perform badly in many applications. This work proposes Adaptive-Saturated RNNs
+(asRNN), a variant that dynamically adjusts its saturation level between the
+two mentioned approaches. Consequently, asRNN enjoys both the capacity of a
+vanilla RNN and the training stability of orthogonal RNNs. Our experiments show
+encouraging results of asRNN on challenging sequence learning benchmarks
+compared to several strong competitors. The research code is accessible at
+https://github.com/ndminhkhoi46/asRNN/.",2304.11790v1
+2023-04-24,Probing gluon saturation via diffractive jets in ultra-peripheral nucleus-nucleus collisions,"We argue that semi-inclusive photo-production of a pair of hard jets via
+coherent diffraction in nucleus-nucleus ultra-peripheral collisions at high
+energy is a golden channel to study gluon saturation. The dominant contribution
+is the diffractive production of three jets in an asymmetric configuration. Two
+of the jets are hard and propagate at nearly central pseudo-rapidities. The
+third jet is semi-hard, with transverse momentum comparable to the nuclear
+saturation momentum, and is well separated in pseudo-rapidity from the hard
+dijets. The emission of the semi-hard jet allows for strong scattering, thus
+avoiding the ""higher-twist"" suppression of the exclusive dijet production due
+to colour transparency. We compute the trijet cross-section using the
+diffractive TMD factorisation which emerges from the CGC effective theory at
+high energy. The cross-section is controlled by gluon saturation, which leaves
+its imprints on the structure of the final state, notably on the rapidity
+distribution.",2304.12401v1
+2023-06-10,Linear saturation numbers of Berge-$C_3$ and Berge-$C_4$,"The linear saturation number $sat^{lin}_k(n,\mathcal{F})$ (linear extremal
+number $ex^{lin}_k(n,\mathcal{F})$) of $\mathcal{F}$ is the minimum (maximum)
+number of hyperedges of an $n$-vertex linear $k$-uniform hypergraph containing
+no member of $\mathcal{F}$ as a subgraph, but the addition of any new hyperedge
+such that the result hypergraph is still a linear $k$-uniform hypergraph
+creates a copy of some hypergraph in $\mathcal{F}$. Determining $ex_3^{lin}(n$,
+Berge-$C_3$) is equivalent to the famous (6,3)-problem, which has been settled
+in 1976. Since then, determining the linear extremal numbers of Berge cycles
+was extensively studied. As the counterpart of this problem in saturation
+problems, the problem of determining the linear saturation numbers of Berge
+cycles is considered. In this paper, we prove that $sat^{lin}_k$($n$,
+Berge-$C_t)\ge \big\lfloor\frac{n-1}{k-1}\big\rfloor$ for any integers $k\ge3$,
+$t\ge 3$, and the equality holds if $t=3$. In addition, we provide an upper
+bound for $sat^{lin}_3(n,$ Berge-$C_4)$ and for any disconnected
+Berge-$C_4$-saturated linear 3-uniform hypergraph, we give a lower bound for
+the number of hyperedges of it.",2306.06435v1
+2023-07-05,A $p$-step-ahead sequential adaptive algorithm for D-optimal nonlinear regression design,"Under a nonlinear regression model with univariate response an algorithm for
+the generation of sequential adaptive designs is studied. At each stage, the
+current design is augmented by adding $p$ design points where $p$ is the
+dimension of the parameter of the model. The augmenting $p$ points are such
+that, at the current parameter estimate, they constitute the locally D-optimal
+design within the set of all saturated designs. Two relevant subclasses of
+nonlinear regression models are focused on, which were considered in previous
+work of the authors on the adaptive Wynn algorithm: firstly, regression models
+satisfying the `saturated identifiability condition' and, secondly, generalized
+linear models. Adaptive least squares estimators and adaptive maximum
+likelihood estimators in the algorithm are shown to be strongly consistent and
+asymptotically normal, under appropriate assumptions. For both model classes,
+if a condition of `saturated D-optimality' is satisfied, the almost sure
+asymptotic D-optimality of the generated design sequence is implied by the
+strong consistency of the adaptive estimators employed by the algorithm. The
+condition states that there is a saturated design which is locally D-optimal at
+the true parameter point (in the class of all designs).",2307.02086v1
+2023-08-02,A Model Predictive Approach for Enhancing Transient Stability of Grid-Forming Converters,"A model predictive control (MPC) method for enhancing post-fault transient
+stability of a grid-forming (GFM) inverter based resources (IBRs) is developed
+in this paper. This proposed controller is activated as soon as the converter
+enters into the post-fault current-saturation mode. It aims at mitigating the
+instability arising from insufficient deceleration due to current saturation
+and thus improving the transient stability of a GFM-IBR. The MPC approach
+optimises the post-fault trajectory of GFM IBRs by introducing appropriate
+corrective phase angle jumps and active power references where the post-fault
+dynamics of GFM IBRs are addressed. These two signals provide controllability
+over GFM IBR's post-fault trajectory. This paper addresses the mitigation of
+oscillations between current-saturation mode and normal mode by forced
+saturation if conditions for remaining in the normal mode do not hold. The
+performance of the proposal is tested via dynamic simulations under various
+grid conditions and compared with other existing strategies. The results
+demonstrate significant improvement in transient stability.",2308.01020v2
+2023-08-22,High Dynamic Range Imaging of Dynamic Scenes with Saturation Compensation but without Explicit Motion Compensation,"High dynamic range (HDR) imaging is a highly challenging task since a large
+amount of information is lost due to the limitations of camera sensors. For HDR
+imaging, some methods capture multiple low dynamic range (LDR) images with
+altering exposures to aggregate more information. However, these approaches
+introduce ghosting artifacts when significant inter-frame motions are present.
+Moreover, although multi-exposure images are given, we have little information
+in severely over-exposed areas. Most existing methods focus on motion
+compensation, i.e., alignment of multiple LDR shots to reduce the ghosting
+artifacts, but they still produce unsatisfying results. These methods also
+rather overlook the need to restore the saturated areas. In this paper, we
+generate well-aligned multi-exposure features by reformulating a motion
+alignment problem into a simple brightness adjustment problem. In addition, we
+propose a coarse-to-fine merging strategy with explicit saturation
+compensation. The saturated areas are reconstructed with similar well-exposed
+content using adaptive contextual attention. We demonstrate that our method
+outperforms the state-of-the-art methods regarding qualitative and quantitative
+evaluations.",2308.11140v1
+2023-11-20,Novel Cross Section Ratios as Possible Signals of Saturation in UPCs,"We propose new cross section ratios in ultra-peripheral A$+$A and $p+$A
+collisions (UPCs) as a potential experimental signal of saturation physics. We
+consider the ratio $R_1$ of elastic vector meson photoproduction cross section
+to the inclusive hadron or jet photoproduction cross section. The ratio can be
+measured in the $\gamma +$A and $\gamma + p$ collisions taking place in the
+UPCs. We label the ratios $R_1 ({\rm A})$ and $R_1 (p)$, respectively.
+Constructing the double ratio $R_{\rm{UPC}} ({\rm A}) = R_1 ({\rm A})/R_1 (p)$,
+and performing a small-$x$ calculation both in the quasi-classical
+approximation and by including small-$x$ evolution, we observe that
+$R_{\rm{UPC}} ({\rm A})$ exhibits a markedly different dependence on the
+nuclear atomic number inside and outside the saturation region. This result
+indicates that $R_{\rm{UPC}} ({\rm A})$ and $R_1 ({\rm A})$ measurements in
+UPCs may help in the experimental searches for the evidence of saturation
+physics.",2311.12208v1
+2023-12-25,A variational principle for the Bowen metric mean dimension of saturated set,"This paper investigates a variational principle for the Bowen metric mean
+dimension of saturated sets $G_K$, where $K$ is a compact connected subset of
+the convex combination of finite invariant measures for the systems with
+g-almost product property. In fact, we prove the variational principle of a
+saturated set with more information, that is $G_K\cap \{x\in X: C_f(X) \subset
+\omega_f(x)\}$, which reveals that the limit point set of a saturated set
+contains all structure of the orbits. As an application, we obtain a more
+general version of multifractal analysis, which is derived independently and
+can imply partial results of Backes and Rodrigues (2023 IEEE Trans. Inform.
+Theory. 69 5485-5496).",2312.15647v2
+2024-01-06,Reflections on Inductive Thematic Saturation as a potential metric for measuring the validity of an inductive Thematic Analysis with LLMs,"This paper presents a set of reflections on saturation and the use of Large
+Language Models (LLMs) for performing Thematic Analysis (TA). The paper
+suggests that initial thematic saturation (ITS) could be used as a metric to
+assess part of the transactional validity of TA with LLM, focusing on the
+initial coding. The paper presents the initial coding of two datasets of
+different sizes, and it reflects on how the LLM reaches some form of analytical
+saturation during the coding. The procedure proposed in this work leads to the
+creation of two codebooks, one comprising the total cumulative initial codes
+and the other the total unique codes. The paper proposes a metric to
+synthetically measure ITS using a simple mathematical calculation employing the
+ratio between slopes of cumulative codes and unique codes. The paper
+contributes to the initial body of work exploring how to perform qualitative
+analysis with LLMs.",2401.03239v1
+2024-02-11,Quantum geometric bound for saturated ferromagnetism,"Despite its abundance in nature, predicting the occurrence of ferromagnetism
+in the ground state is possible only under very limited conditions such as in a
+flat band system with repulsive interaction or in a band with a single hole
+under infinitely large Coulomb repulsion, etc. Here, we propose a general
+condition to achieve saturated ferromagnetism based on the quantum geometry of
+electronic wave functions in itinerant electron systems. By analyzing
+multi-band repulsive Hubbard models with an integer band filling, relevant to
+either ferromagnetic insulators or semimetals, we propose a rigorous quantum
+geometric upper bound on the spin stiffness. By employing this geometric bound,
+we establish that saturated ferromagnetism is prohibited in the absence of
+interband coupling, even when the local Hubbard repulsion is infinitely large.
+As a corollary, this shows that saturated ferromagnetism is forbidden in any
+half-filled Hubbard model. We also derive the condition that the upper bound of
+the spin stiffness can be completely characterized by the Abelian quantum
+metric. We believe that our findings reveal a profound connection between
+quantum geometry and ferromagnetism, which can be extended to various
+symmetry-broken ground states in itinerant electronic systems.",2402.07171v1
+2024-02-20,Inference on LATEs with covariates,"In theory, two-stage least squares (TSLS) identifies a weighted average of
+covariate-specific local average treatment effects (LATEs) from a saturated
+specification without making parametric assumptions on how available covariates
+enter the model. In practice, TSLS is severely biased when saturation leads to
+a number of control dummies that is of the same order of magnitude as the
+sample size, and the use of many, arguably weak, instruments. This paper
+derives asymptotically valid tests and confidence intervals for an estimand
+that identifies the weighted average of LATEs targeted by saturated TSLS, even
+when the number of control dummies and instrument interactions is large. The
+proposed inference procedure is robust against four key features of saturated
+economic data: treatment effect heterogeneity, covariates with rich support,
+weak identification strength, and conditional heteroskedasticity.",2402.12607v1
+2024-03-04,Saturated Partial Embeddings of Planar Graphs,"In this work, we study how far one can deviate from optimal behavior when
+embedding a planar graph. For a planar graph $G$, we say that a plane subgraph
+$H\subseteq G$ is a \textit{plane-saturated subgraph} if adding any edge
+(possibly with new vertices) to $H$ would either violate planarity or make the
+resulting graph no longer a subgraph of $G$. For a planar graph $G$, we define
+the \textit{plane-saturation ratio}, $\psr(G)$, as the minimum value of
+$\frac{e(H)}{e(G)}$ for a plane-saturated subgraph $H$ of $G$ and investigate
+how small $\psr(G)$ can be. While there exist planar graphs where $\psr(G)$ is
+arbitrarily close to $0$, we show that for all twin-free planar graphs,
+$\psr(G)>1/16$, and that there exist twin-free planar graphs where $\psr(G)$ is
+arbitrarily close to $1/16$. In fact, we study a broader category of planar
+graphs, focusing on classes characterized by a bounded number of degree $1$ and
+degree $2$ twin vertices. We offer solutions for some instances of bounds while
+positing conjectures for the remaining ones.",2403.02458v1
+2024-03-06,Saturating Sorting without Sorts,"We present a first-order theorem proving framework for establishing the
+correctness of functional programs implementing sorting algorithms with
+recursive data structures.
+  We formalize the semantics of recursive programs in many-sorted first-order
+logic and integrate sortedness/permutation properties within our first-order
+formalization. Rather than focusing on sorting lists of elements of specific
+first-order theories, such as integer arithmetic, our list formalization relies
+on a sort parameter abstracting (arithmetic) theories and hence concrete sorts.
+We formalize the permutation property of lists in first-order logic so that we
+automatically prove verification conditions of such algorithms purely by
+superpositon-based first-order reasoning. Doing so, we adjust recent efforts
+for automating inducion in saturation. We advocate a compositional approach for
+automating proofs by induction required to verify functional programs
+implementing and preserving sorting and permutation properties over
+parameterized list structures. Our work turns saturation-based first-order
+theorem proving into an automated verification engine by (i) guiding automated
+inductive reasoning with manual proof splits and (ii) fully automating
+inductive reasoning in saturation. We showcase the applicability of our
+framework over recursive sorting algorithms, including Mergesort and Quicksort.",2403.03712v1
+2024-03-30,Saturation effect in confined quantum systems with energy-dependent potentials,"In this paper, we study the saturation effect in the energy or mass spectra
+of three quantum models with energy-dependent potentials: the harmonic
+oscillator, the hydrogen atom, and the heavy quarkonia. We used the method
+proposed in \cite{garcia2009exactly}, which is based on studying various
+canonical point and gauge transformations applied to a function, $g(x)$,
+multiplied by a given differential equation of known solutions as special
+orthogonal functions, that convert it into a Schr{{\""o}}dinger-like equation.
+The first two models stem from implementing the method on the confluent
+hypergeometric differential of the well-known solutions ${}_1 F_1$, while the
+third model (heavy quarkonia) stems possibly from the hypergeometric
+differential of the well-known solutions ${}_2 F_1$. In particular, the heavy
+quarkonia mass spectra for both $c\bar c$ and $b\bar b$ are produced at
+different values of the saturation parameter $\lambda$ and compared with the
+available experimental data. It is found that these systems may exhibit
+saturation effect when the energy-dependent effect is included.",2404.00302v1
+2002-12-11,Lectures on Diffraction and Saturation of Nuclear Partons in DIS off Heavy Nuclei,"The Lorentz contraction of ultrarelativistic nuclei entails a spatial overlap
+and fusion (recombination, saturation) of partons belonging to different
+nucleons at the same impact parameter. In these lectures we present a
+consistent description of the fusion of partons in terms of nuclear attenuation
+of color dipole states of the photon and collective Weizs\""acker-Williams (WW)
+gluon structure function of a nucleus. The point that all observables for DIS
+off nuclei are uniquely calculable in terms of the nuclear WW glue amounts to a
+new form of factorization in the saturation regime.
+  We start with the theory of multichannel propagation of color dipoles in a
+nuclear medium including the color-singlet to color-octet to color-octet
+transitions. We show how the Glauber-Gribov formulas are recovered from the
+multichannel formalism. Then we derive the two-plateau momentum distribution of
+final state (FS) quarks produced in deep inelastic scattering (DIS) off nuclei
+in the saturation regime. Then we comment on the signatures of saturation in
+exclusive diffractive DIS. A large body of these lectures is on the recent
+theory of jet-jet inclusive cross sections. We show that for hard dijets the
+decorrelation momentum is of the order of the nuclear saturation momentum
+$Q_A$. For minijets with the transverse momentum below the saturation scale we
+predict a complete disappearance of the azimuthal jet-jet correlation. We
+conclude with comment on a possible relevance of the decorrelation of jets to
+the experimental data from the STAR-RHIC Collaboration.",0212161v2
+2016-12-07,"Field emission: the theoretical link between voltage loss, reduction in field enhancement factor, and Fowler-Nordheim-plot saturation","With a large-area field electron emitter, when an individual post-like
+emitter is sufficiently resistive, and current through it sufficiently large,
+then voltage loss occurs along it. This Letter provides a simple analytical and
+conceptual demonstration that this voltage loss is directly and inextricably
+linked to a reduction in the field enhancement factor (FEF) at the post apex. A
+formula relating apex-FEF reduction to this voltage loss was obtained in the
+paper by E. Minoux, O. Groening, K. B. K. Teo, S. H. Dalal, L. Gangloff, J.-P.
+Schnell, L. Hudanski, I. Y. Y. Bu., P. Vincent, P. Legagneux, G. A. J.
+Amaratunga, and W. I. Milne [Nano Lett. 5, 2135 (2005)], by fitting to
+numerical results from a Laplace solver. This Letter derives the same formula
+analytically, by using a ""floating sphere"" model. The analytical proof brings
+out the underlying physics more clearly, and shows that the effect is a general
+phenomenon, related to reduction in the magnitude of the surface charge in the
+most protruding parts of an emitter. Voltage-dependent FEF-reduction is one
+cause of ""saturation"" in Fowler-Nordheim plots. Another is a voltage-divider
+effect, due to measurement-circuit resistance. An integrated theory of both
+effects is presented. Both together, or either by itself, can cause saturation.
+Experimentally, if saturation occurs but voltage loss is small (< 20 V, say),
+then saturation is more probably due to FEF-reduction than voltage division. In
+this case, existing treatments of electrostatic interaction (""shielding"")
+between closely spaced emitters may need modification. Other putative causes of
+saturation exist, so the present theory is a partial story. Its extension seems
+possible, and could lead to a more general physical understanding of the causes
+of FN-plot saturation.",1612.02187v2
+2019-10-18,Does carrier velocity saturation help to enhance fmax in graphene field-effect transistors?,"It has been argued that current saturation in graphene field-effect
+transistors (GFETs) is needed to get the highest possible maximum oscillation
+frequency (fmax). This paper numerically investigates whether velocity
+saturation can help to get better current saturation and if that correlates
+with enhanced fmax. For such a purpose, we used a drift-diffusion simulator
+that includes several factors that influence output conductance, especially at
+short channel lengths and-or large drain bias: short-channel electrostatics,
+saturation velocity, graphene-dielectric interface traps, and self-heating
+effects. As a testbed for our investigation, we analyzed fabricated GFETs with
+high extrinsin cutoff frequency fT,x (34 GHz) and fmax (37 GHz). Our
+simulations allow for a microscopic (local) analysis of the channel parameteres
+such as carrier concentration, drift and saturation velocities. For biases far
+away from the Dirac voltage, where the channel behaves as unipolar, we
+confirmed that the higher is the drift velocity, as close as possible to the
+saturation velocity, the greater fmax is. However, the largest fmax is recorded
+at biases near the crossover between unipolar and bipolar behavior, where it
+does not hold that the highest drift velocity maximizes fmax. In fact, the
+position and magnitude of the largest fmax depend on the complex interplay
+between the carrier concentration and total velocity which, in turn, are
+impacted by the self-heating. Importantly, this effect was found to severely
+limit radio-frequency performance, reducing the maximum fmax from around 60 to
+40 GHz.",1910.08304v1
+2020-12-15,Saturation effects in SIDIS at very forward rapidities,"Using the dipole picture for electron-nucleus deep inelastic scattering at
+small Bjorken $x$, we study the effects of gluon saturation in the nuclear
+target on the cross-section for SIDIS (single inclusive hadron, or jet,
+production). We argue that the sensitivity of this process to gluon saturation
+can be enhanced by tagging on a hadron (or jet) which carries a large fraction
+$z \simeq 1$ of the longitudinal momentum of the virtual photon. This opens the
+possibility to study gluon saturation in relatively hard processes, where the
+virtuality $Q^2$ is (much) larger than the target saturation momentum $Q_s^2$,
+but such that $z(1-z)Q^2\lesssim Q_s^2$. Working in the limit $z(1-z)Q^2\ll
+Q_s^2$, we predict new phenomena which would signal saturation in the SIDIS
+cross-section. For sufficiently low transverse momenta $k_\perp\ll Q_s$ of the
+produced particle, the dominant contribution comes from elastic scattering in
+the black disk limit, which exposes the unintegrated quark distribution in the
+virtual photon. For larger momenta $k_\perp\gtrsim Q_s$, inelastic collisions
+take the leading role. They explore gluon saturation via multiple scattering,
+leading to a Gaussian distribution in $k_\perp$ centred around $Q_s$. When
+$z(1-z)Q^2\ll Q^2$, this results in a Cronin peak in the nuclear modification
+factor (the $R_{pA}$ ratio) at moderate values of $x$. With decreasing $x$,
+this peak is washed out by the high-energy evolution and replaced by nuclear
+suppression ($R_{pA}<1$) up to large momenta $k_\perp\gg Q_s$. Still for
+$z(1-z)Q^2\ll Q_s^2$, we also compute SIDIS cross-sections integrated over
+$k_\perp$. We find that both elastic and inelastic scattering are controlled by
+the black disk limit, so they yield similar contributions, of zeroth order in
+the QCD coupling.",2012.08562v2
+2000-07-12,X-ray Emission From Nearby M-dwarfs: the Super-saturation Phenomenon,"A rotation rate and X-ray luminosity analysis is presented for rapidly
+rotating single and binary M-dwarf systems. X-ray luminosities for the majority
+of both single & binary M-dwarf systems with periods below $\simeq 5-6$ days
+(equatorial velocities, V$_{eq}>$ 6 km~s$^{-1}$) are consistent with the
+current rotation-activity paradigm, and appear to saturate at about $10^{-3}$
+of the stellar bolometric luminosity. The single M-dwarf data show tentative
+evidence for the super-saturation phenomenon observed in some ultra-fast
+rotating ($>$ 100 km~s$^{-1}$) G & K-dwarfs in the IC 2391, IC 2602 and Alpha
+Persei clusters. The IC 2391 M star VXR60b is the least X-ray active and most
+rapidly rotating of the short period (P$_{rot}<$ 2 days) stars considered
+herein, with a period of 0.212 days and an X-ray activity level about 1.5 sigma
+below the mean X-ray emission level for most of the single M-dwarf sample. For
+this star, and possibly one other, we cautiously believe that we have
+identified the first evidence of super-saturation in M-dwarfs. If we are wrong,
+we demonstrate that only M-dwarfs rotating close to their break up velocities
+are likely to exhibit the super-saturation effect at X-ray wavelengths.",0007159v1
+2006-06-26,Identification of New M Dwarfs in the Solar Neighborhood,"We present the results from a spectroscopic study of 1080 nearby active M
+dwarfs, selected by correlating the 2MASS and ROSAT catalogs. We have derived
+the spectral types and estimated distances for all of our stars. The spectral
+types range between K5 and M6. Nearly half of our stars lie within 50 pc. We
+have measured the equivalent width of the H alpha emission line. Our targets
+show an increase in chromospheric activity from early to mid-spectral types,
+with a peak in activity around M5. Using the count rate and hardness ratios
+obtained from the ROSAT catalog, we have derived the X-ray luminosities. Our
+stars display a ""saturation-type"" relation between the chromospheric and
+coronal activity. The relation is such that log (Lx/Lbol) remains ""saturated""
+at a value of about -3 for varying H alpha equivalent width. We have found 568
+matches in the USNO-B catalog, and have derived the tangential velocities for
+these stars. There is a slight trend of decreasing chromospheric activity with
+age, such that the stars with higher Vtan have lower H alpha equivalent widths.
+The coronal emission, however, remains saturated at a value of log (Lx/Lbol) -3
+for varying tangential velocities, suggesting that the coronal activity remains
+saturated with age. We do not find any break in the saturation-type relation at
+the spectral type where stars become fully convective (~M3.5). Most of the
+stars in our sample show more coronal emission than the dMe stars in the Hyades
+and Praesepe clusters, and have Vtan< 40km/s, suggesting a young population.",0606617v1
+2002-04-24,Perturbative Saturation and the Soft Pomeron,"We show that perturbation theory provides two distinct mechanisms for the
+power like growth of hadronic cross sections at high energy. One, the leading
+BFKL effect is due to the growth of the parton density, and is characterized by
+the leading BFKL exponent. The other mechanism is due to the infrared
+diffusion, or the long range nature of the Coulomb field of perturbatively
+massless gluons. When perturbative saturation effects are taken into account,
+the first mechanism is rendered ineffective but the second one persists. We
+suggest that these two distinct mechanisms are responsible for the appearance
+of two pomerons. The density growth effects are responsible for the hard
+pomeron and manifest themselves in small systems (e.g. gamma^* or small size
+fluctuations in the proton wave function) where saturation effects are not
+important. The soft pomeron is the manifestation of the exponential growth of
+the black saturated regions which appear in typical hadronic systems. We point
+out that the nonlinear generalization of the BFKL equation which takes into
+account wave function saturation effects (""pomeron loops"") provides a well
+defined perturbative framework for the calculation of the soft pomeron
+intercept. The conjecture of a perturbative soft pomeron is consistent with
+picturing the proton as a loosely bound system of several small black regions
+corresponding e.g. to constituent quarks of size about 0.3 fm. Phenomenological
+implications of this picture are compatible with the main qualitative features
+of data on p-p scattering.",0204277v1
+2006-08-04,Saturation physics at HERA and RHIC: An unified description,"One of the frontiers of QCD which are intensely investigated in high energy
+experiments is the high energy (small $x$) regime, where we expect to observe
+the non-linear behavior of the theory. In this regime, the growth of the parton
+distribution should saturate, forming a Color Glass Condensate (CGC). In fact,
+signals of parton saturation have already been observed both in $ep$ deep
+inelastic scattering at HERA and in deuteron-gold collisions at RHIC.
+Currently, the description of the experimental data of these experiments is
+possible considering different phenomenological saturation models for the two
+processes within the CGC formalism. In this letter we analyze the universality
+of these dipole cross section parameterizations and verify that they are not
+able to describe the HERA and RHIC data simultaneously. We analyze possible
+improvements in the parameterizations and propose a new parametrization for the
+forward dipole amplitude which allows us to describe quite well the small-$x$
+$ep$ HERA data on $F_2$ structure function as well as the $dAu$ RHIC data on
+charged hadron spectra. It is an important signature of the universality of the
+saturation physics.",0608063v2
+2006-03-04,A generalization of the integer linear infeasibility problem,"Does a given system of linear equations with nonnegative constraints have an
+integer solution? This is a fundamental question in many areas. In statistics
+this problem arises in data security problems for contingency table data and
+also is closely related to non-squarefree elements of Markov bases for sampling
+contingency tables with given marginals. To study a family of systems with no
+integer solution, we focus on a commutative semigroup generated by a finite
+subset of $\Z^d$ and its saturation. An element in the difference of the
+semigroup and its saturation is called a ``hole''. We show the necessary and
+sufficient conditions for the finiteness of the set of holes. Also we define
+fundamental holes and saturation points of a commutative semigroup. Then, we
+show the simultaneous finiteness of the set of holes, the set of non-saturation
+points, and the set of generators for saturation points. We apply our results
+to some three- and four-way contingency tables. Then we will discuss the time
+complexities of our algorithms.",0603108v5
+1996-12-02,Nuclear Matter Studies with Density-dependent Meson-Nucleon Coupling Constants,"Due to the internal structure of the nucleon, we should expect, in general,
+that the effective meson nucleon parameters may change in nuclear medium. We
+study such changes by using a chiral confining model of the nucleon. We use
+density-dependent masses for all mesons except the pion. Within a
+Dirac-Brueckner analysis, based on the relativistic covariant structure of the
+NN amplitude, we show that the effect of such a density dependence in the NN
+interaction on the saturation properties of nuclear matter, while not large, is
+quite significant. Due to the density dependence of the $g_{\sigma NN}$, as
+predicted by the chiral confining model, we find, in particular, a looping
+behavior of the binding energy at saturation as a function of the saturation
+density. A simple model is described, which exhibits looping and which is shown
+to be mainly caused by the presence of a peak in the density dependence of the
+medium modified $\sigma N$ coupling constant at low density.
+  The effect of density dependence of the coupling constants and the meson
+masses tends to improve the results for $E/A$ and density of nuclear matter at
+saturation. From the present study we see that the relationship between binding
+energy and saturation density may not be as universal as found in
+nonrelativistic studies and that more model dependence is exhibited once medium
+modifications of the basic nuclear interactions are considered.",9612007v2
+2008-01-04,Single-contact pressure solution creep on calcite monocrystals,"Pressure solution creep rates and interface structures have been measured by
+two methods on calcite single crystals. In the first kind of experiments,
+calcite monocrystals were indented at 40 degrees C for six weeks using ceramic
+indenters under stresses in the 50-200 MPa range in a saturated solution of
+calcite and in a calcite-saturated aqueous solution of NH4Cl. The deformation
+(depth of the hole below the indenter) is measured ex-situ at the end of the
+experiment. In the second type of experiment, calcite monocrystals were
+indented by spherical glass indenters for 200 hours under stresses in the 0-100
+MPa range at room temperature in a saturated aqueous solution of calcite. The
+displacement of the indenter was continuously recorded using a specially
+constructed differential dilatometer. The experiments conducted in a
+calcite-saturated aqueous solution of NH4Cl show an enhanced indentation rate
+owing to the fairly high solubility of calcite in this solution. In contrast,
+the experiments conducted in a calcite-saturated aqueous solution show moderate
+indentation rate and the dry control experiments did not show any measurable
+deformation. The rate of calcite indentation is found to be inversely
+proportional to the indenter diameter, thus indicating that the process is
+diffusion-controlled. The microcracks in the dissolution region under the
+indenter dramatically enhance the rate of calcite indentation by a significant
+reduction of the distance of solute transport in the trapped fluid phase. This
+result indicates that care should be taken in extrapolating the kinetic data of
+pressure solution creep from one mineral to another.",0801.0725v1
+2008-02-15,New Implementation Framework for Saturation-Based Reasoning,"The saturation-based reasoning methods are among the most theoretically
+developed ones and are used by most of the state-of-the-art first-order logic
+reasoners. In the last decade there was a sharp increase in performance of such
+systems, which I attribute to the use of advanced calculi and the intensified
+research in implementation techniques. However, nowadays we are witnessing a
+slowdown in performance progress, which may be considered as a sign that the
+saturation-based technology is reaching its inherent limits. The position I am
+trying to put forward in this paper is that such scepticism is premature and a
+sharp improvement in performance may potentially be reached by adopting new
+architectural principles for saturation. The top-level algorithms and
+corresponding designs used in the state-of-the-art saturation-based theorem
+provers have (at least) two inherent drawbacks: the insufficient flexibility of
+the used inference selection mechanisms and the lack of means for intelligent
+prioritising of search directions. In this position paper I analyse these
+drawbacks and present two ideas on how they could be overcome. In particular, I
+propose a flexible low-cost high-precision mechanism for inference selection,
+intended to overcome problems associated with the currently used instances of
+clause selection-based procedures. I also outline a method for intelligent
+prioritising of search directions, based on probing the search space by
+exploring generalised search directions. I discuss some technical issues
+related to implementation of the proposed architectural principles and outline
+possible solutions.",0802.2127v1
+2008-05-08,Could saturation effects be visible in a future electron-ion collider?,"We expect to observe parton saturation in a future electron - ion collider.
+In this letter we discuss this expectation in more detail considering two
+different models which are in good agreement with the existing experimental
+data on nuclear structure functions. In particular, we study the predictions of
+saturation effects in electron - ion collisions at high energies, using a
+generalization for nuclear targets of the b-CGC model, which describes the $ep$
+HERA quite well. We estimate the total, longitudinal and charm structure
+functions in the dipole picture and compare them with the predictions obtained
+using collinear factorization and modern sets of nuclear parton distributions.
+Our results show that inclusive observables are not very useful in the search
+for saturation effects. In the small $x$ region they are very difficult to
+disentangle from the predictions of the collinear approaches . This happens
+mainly because of the large uncertainties in the latter. On the other hand, our
+results indicate that the contribution of diffractive processes to the total
+cross section is about 20 % at large A and small Q^2, allowing for a detailed
+study of diffractive observables. The study of diffractive processes becomes
+essential to observe parton saturation.",0805.1255v1
+2009-04-16,Bounds on M/R for static objects with a positive cosmological constant,"We consider spherically symmetric static solutions of the Einstein equations
+with a positive cosmological constant $\Lambda,$ which are regular at the
+centre, and we investigate the influence of $\Lambda$ on the bound of M/R,
+where M is the ADM mass and R is the area radius of the boundary of the static
+object. We find that for any solution which satisfies the energy condition
+$p+2p_{\perp}\leq\rho,$ where $p\geq 0$ and $p_{\perp}$ are the radial and
+tangential pressures respectively, and $\rho\geq 0$ is the energy density, and
+for which $0\leq \Lambda R^2\leq 1,$ the inequality
+  \frac{M}{R}\leq\frac29-\frac{\Lambda R^2}{3}+\frac29 \sqrt{1+3\Lambda R^2},
+holds. If $\Lambda=0$ it is known that infinitely thin shell solutions uniquely
+saturate the inequality, i.e. the inequality is sharp in that case. The
+situation is quite different if $\Lambda>0.$ Indeed, we show that infinitely
+thin shell solutions do not generally saturate the inequality except in the two
+degenerate situations $\Lambda R^2=0$ and $\Lambda R^2=1$. In the latter
+situation there is also a constant density solution, where the exterior
+spacetime is the Nariai solution, which saturates the inequality, hence, the
+saturating solution is non-unique. In this case the cosmological horizon and
+the black hole horizon coincide. This is analogous to the charged situation
+where there is numerical evidence that uniqueness of the saturating solution is
+lost when the inner and outer horizons of the Reissner-Nordstr\""{o}m solution
+coincide.",0904.2497v3
+2010-08-25,Heavy quarkonium production: Nontrivial transition from pA to AA collisions,"Two novel QCD effects, double color filtering and mutual boosting of the
+saturation scales in colliding nuclei, affect the transparency of the nuclei
+for quark dipoles in comparison with proton-nucleus collisions. The former
+effect increases the survival probability of the dipoles, since color filtering
+in one nucleus makes the other one more transparent. The second effect acts in
+the opposite direction and is stronger, it makes the colliding nuclei more
+opaque than in the case of pA collisions. As a result of parton saturation in
+nuclei the effective scale is shifted upwards, what leads to an increase of the
+gluon density at small x. This in turn leads to a stronger transverse momentum
+broadening in AA compared with pA collisions, i.e. to an additional growth of
+the saturation momentum. Such a mutual boosting leads to a system of
+reciprocity equations, which result in a saturation scale, a few times higher
+in AA than in pA collisions at the energies of LHC. Since the dipole cross
+section is proportional to the saturation momentum squared, the nuclei become
+much more opaque for dipoles in AA than in pA collisions. For the same reason
+gluon shadowing turns out to be boosted to a larger magnitude compared with the
+product of the gluon shadowing factors in each of the colliding nuclei. All
+these effects make it more difficult to establish a baseline for anomalous
+J/Psi suppression in heavy ion collisions at high energies.",1008.4272v2
+2011-08-31,Two-dimensional Moist Stratified Turbulence and the Emergence of Vertically Sheared Horizontal Flows,"Moist stratified turbulence is studied in a two-dimensional Boussinesq system
+influenced by condensation and evaporation. The problem is set in a periodic
+domain and employs simple evaporation and condensation schemes, wherein both
+the processes push parcels towards saturation. Numerical simulations
+demonstrate the emergence of a moist turbulent state consisting of ordered
+structures with a clear power-law type spectral scaling from initially
+spatially uncorrelated conditions. An asymptotic analysis in the limit of rapid
+condensation and strong stratification shows that, for initial conditions with
+enough water substance to saturate the domain, the equations support a
+straightforward state of moist balance characterized by a hydrostatic,
+saturated, vertically sheared horizontal flow (VSHF). For such initial
+conditions, by means of long time numerical simulations, the emergence of moist
+balance is verified. Specifically, starting from uncorrelated data, subsequent
+to the development of a moist turbulent state, the system experiences a rather
+abrupt transition to a regime which is close to saturation and dominated by a
+strong VSHF. On the other hand, initial conditions which do not have enough
+water substance to saturate the domain, do not attain moist balance. Rather,
+the system remains in a turbulent state and oscillates about moist balance.
+Even though balance is not achieved with these general initial conditions, the
+time scale of oscillation about moist balance is much larger than the imposed
+time scale of condensation and evaporation, thus indicating a distinct dominant
+slow component in the moist stratified two-dimensional turbulent system.",1108.6192v1
+2012-04-06,Constructing regular ultrafilters from a model-theoretic point of view,"This paper contributes to the set-theoretic side of understanding Keisler's
+order. We consider properties of ultrafilters which affect saturation of
+unstable theories: the lower cofinality $\lcf(\aleph_0, \de)$ of $\aleph_0$
+modulo $\de$, saturation of the minimum unstable theory (the random graph),
+flexibility, goodness, goodness for equality, and realization of symmetric
+cuts. We work in ZFC except when noted, as several constructions appeal to
+complete ultrafilters thus assume a measurable cardinal. The main results are
+as follows. First, we investigate the strength of flexibility, detected by
+non-low theories. Assuming $\kappa > \aleph_0$ is measurable, we construct a
+regular ultrafilter on $\lambda \geq 2^\kappa$ which is flexible (thus: ok) but
+not good, and which moreover has large $\lcf(\aleph_0)$ but does not even
+saturate models of the random graph. We prove that there is a loss of
+saturation in regular ultrapowers of unstable theories, and give a new proof
+that there is a loss of saturation in ultrapowers of non-simple theories.
+Finally, we investigate realization and omission of symmetric cuts, significant
+both because of the maximality of the strict order property in Keisler's order,
+and by recent work of the authors on $SOP_2$. We prove that for any $n <
+\omega$, assuming the existence of $n$ measurable cardinals below $\lambda$,
+there is a regular ultrafilter $D$ on $\lambda$ such that any $D$-ultrapower of
+a model of linear order will have $n$ alternations of cuts, as defined below.
+Moreover, $D$ will $\lambda^+$-saturate all stable theories but will not
+$(2^{\kappa})^+$-saturate any unstable theory, where $\kappa$ is the smallest
+measurable cardinal used in the construction.",1204.1481v1
+2012-06-24,Saturation Levels for White-light Flares of Flare Stars: Variation of Minimum Flare Duration for Saturation,"Taking into account results obtained from models and from statistical
+analyses of obtained parameters, we discuss flare activity levels and flare
+characteristics of five UV Ceti stars. We present the parameters of unpublished
+flares detected over two years of observations of V1005 Ori. We compare
+parameters of the U-band flares detected over several seasons of observations
+of AD Leo, EV Lac, EQ Peg, V1054 Oph, and V1005 Ori. Flare frequencies
+calculated for all program stars and maximum energy levels of the flares are
+compared, and we consider which is the most correct parameter as an indicator
+of flare activity levels. Using the One Phase Exponential Association function,
+the distributions of flare equivalent duration versus flare total duration are
+modeled for each program star. We use the Independent Samples t-Test in the
+statistical analyses of the parameters obtained from the models. The results
+reveal some properties of flare processes occurring on the surfaces of UV Ceti
+type stars. (1) Flare energies cannot be higher than a specific value
+regardless of the length of the flare total duration. This must be a saturation
+level for white-light flares occurring in flare processes observed in the U
+band. Thus, for the first time it is shown that white-light flares have a
+saturation in a specific energy range. (2) The span values, which are the
+difference between the equivalent durations of flares with the shortest and
+longest total durations, are almost equal for each star. (3) The half-life
+values, minimum flare durations for saturation, increase toward the later
+spectral types.",1206.5793v1
+2012-08-10,A Dividing Line Within Simple Unstable Theories,"We give the first (ZFC) dividing line in Keisler's order among the unstable
+theories, specifically among the simple unstable theories. That is, for any
+infinite cardinal $\lambda$ for which there is $\mu < \lambda \leq 2^\mu$, we
+construct a regular ultrafilter D on $\lambda$ such that (i) for any model $M$
+of a stable theory or of the random graph, $M^\lambda/D$ is
+$\lambda^+$-saturated but (ii) if $Th(N)$ is not simple or not low then
+$N^\lambda/D$ is not $\lambda^+$-saturated. The non-saturation result relies on
+the notion of flexible ultrafilters. To prove the saturation result we develop
+a property of a class of simple theories, called Qr1, generalizing the fact
+that whenever $B$ is a set of parameters in some sufficiently saturated model
+of the random graph, $|B| = \lambda$ and $\mu < \lambda \leq 2^\mu$, then there
+is a set $A$ with $|A| = \mu$ such that any non-algebraic $p \in S(B)$ is
+finitely realized in $A$. In addition to giving information about simple
+unstable theories, our proof reframes the problem of saturation of ultrapowers
+in several key ways. We give a new characterization of good filters in terms of
+""excellence,"" a measure of the accuracy of the quotient Boolean algebra. We
+introduce and develop the notion of {moral} ultrafilters on Boolean algebras.
+We prove a so-called ""separation of variables"" result which shows how the
+problem of constructing ultrafilters to have a precise degree of saturation may
+be profitably separated into a more set-theoretic stage, building an excellent
+filter, followed by a more model-theoretic stage: building moral ultrafilters
+on the quotient Boolean algebra, a process which highlights the complexity of
+certain patterns, arising from first-order formulas, in certain Boolean
+algebras.",1208.2140v1
+2012-11-02,Multiplicities and $p_T$ spectra in ultrarelativistic heavy ion collisions from a next-to-leading order improved perturbative QCD + saturation + hydrodynamics model,"We bring the EKRT framework, which combines perturbative QCD (pQCD) minijet
+production with gluon saturation and hydrodynamics, to next-to-leading order
+(NLO) in pQCD as rigorously as possible. We chart the model uncertainties, and
+study the viability and predictive power of the model in the light of the RHIC
+and LHC measurements in central $A+A$ collisions. In particular, we introduce a
+new set of measurement functions to define the infrared- and collinear-safe
+minijet transverse energy, $E_T$, in terms of which we formulate the
+saturation. We update the framework with the EPS09 NLO nuclear parton
+distributions (nPDFs), and study the propagation of the nPDF uncertainties into
+the computed $E_T$, saturation scales and the final-state multiplicities. The
+key parameters, which need to be fixed using the measurements, are identified,
+and their correlation is discussed. We convert the saturated minijet $E_T$ into
+QCD-matter initial conditions for longitudinally boost-invariant ideal
+hydrodynamics. We compute the charged-particle multiplicities and identified
+bulk hadron $p_T$ spectra in 5% most central Au+Au collisions at RHIC and Pb+Pb
+at the LHC. We obtain an encouragingly good agreement with the experimental
+data, simultaneously at RHIC and LHC, showing that the approach has a definite
+predictive power.",1211.0461v1
+2012-12-12,Analysis of combined HERA data in the Impact-Parameter dependent Saturation model,"The Impact-Parameter dependent Saturation Model (IP-Sat) is a simple dipole
+model that incorporates key features of the physics of gluon saturation and
+matches smoothly to the perturbative QCD dipole expression at large Q^2 for a
+given x. It was previously shown that the model gives a good description of
+HERA data suggesting evidence for gluon saturation effects at small x. The
+model has also been applied to proton-proton and proton-nucleus collisions and
+provides the basis for the IP-Glasma model of initial conditions in heavy ion
+collisions. Here we present a reanalysis of available data in electron-proton
+collisions at small Bjorken-x, including the recently released combined data
+from the ZEUS and H1 collaborations. We first confront the model to the high
+precision combined data for the reduced cross-section and obtain its
+parameters. With these parameters fixed, we compare model results to data for
+the structure function F_2, the longitudinal structure function F_L, the charm
+structure function F_2^{c\bar{c}}, exclusive vector meson (J/\psi, \phi and
+\rho) production and Deeply Virtual Compton Scattering (DVCS). Excellent
+agreement is obtained for the processes considered at small x in a wide range
+of Q^2. Our results strongly hint at universality of the IP-Sat dipole
+amplitude and the extracted impact-parameter distribution of the proton. They
+also provide a benchmark for further refinements in studies of QCD saturation
+at colliders.",1212.2974v1
+2013-01-04,On the role of electron-nucleus contact and microwave saturation in Thermal Mixing DNP,"We have explored the manifold physical scenario emerging from a model of
+Dynamic Nuclear Polarization (DNP) via thermal mixing under the hypothesis of
+highly effective electron-electron interaction. When the electron and nuclear
+reservoirs are also assumed to be in strong thermal contact and the microwave
+irradiation saturates the target electron transition, the enhancement of the
+nuclear polarization is expected to be considerably high even if the
+irradiation frequency is set far away from the centre of the ESR line (as
+already observed by Borghini) and the typical polarization time is reduced on
+moving towards the boundaries of said line. More reasonable behaviours are
+obtained by reducing the level of microwave saturation or the contact between
+electrons and nuclei in presence of nuclear leakage. In both cases the function
+describing the dependency of the steady state nuclear polarization on the
+frequency of irradiation becomes sharper at the edges and the build up rate
+decreases on moving off-resonance. If qualitatively similar in terms of the
+effects produced on nuclear polarization, the degree of microwave saturation
+and of electron-nucleus contact has a totally different impact on electron
+polarization, which is of course strongly correlated to the effectiveness of
+saturation and almost insensitive, at the steady state, to the magnitude of the
+interactions between the two spin reservoirs. The likelihood of the different
+scenario is discussed in the light of the experimental data currently available
+in literature, to point out which aspects are suitably accounted and which are
+not by the declinations of thermal mixing DNP considered here.",1301.0798v2
+2014-08-14,"Tameness, Uniqueness and amalgamation","We combine two approaches to the study of classification theory of AECs: 1.
+that of Shelah: studying non-forking frames without assuming the amalgamation
+property but assuming the existence of uniqueness triples and 2. that of
+Grossberg and VanDieren: (studying non-splitting) assuming the amalgamation
+property and tameness. In [JrSh875], we derive a good non-forking
+$\lambda^+$-frame from a semi-good non-forking $\lambda$-frame. But the classes
+$K_{\lambda^+}$ and $\preceq \restriction K_{\lambda^+}$ are replaced:
+$K_{\lambda^+}$ is restricted to the saturated models and the partial order
+$\preceq \restriction K_{\lambda^+}$ is restricted to the partial order
+$\preceq^{NF}_{\lambda^+}$. Here, we avoid the restriction of the partial order
+$\preceq \restriction K_{\lambda^+}$, assuming that every saturated model (in
+$\lambda^+$ over $\lambda$) is an amalgamation base and
+$(\lambda,\lambda^+)$-tameness for non-forking types over saturated models, (in
+addition to the hypotheses of [JrSh875]): We prove that $M \preceq M^+$ if and
+only if $M \preceq^{NF}_{\lambda^+}M^+$, provided that $M$ and $M^+$ are
+saturated models. We present sufficient conditions for three good non-forking
+$\lambda^+$-frames: one relates to all the models of cardinality $\lambda^+$
+and the two others relate to the saturated models only. By an `unproven claim'
+of Shelah, if we can repeat this procedure $\omega$ times, namely, `derive'
+good non-forking $\lambda^{+n}$ frame for each $n<\omega$ then the categoricity
+conjecture holds. Vasey applies one of our main theorems in a proof of the
+categoricity conjecture under the above `unproven claim' of Shelah and more
+assumptions. In [Jrprime], we apply the main theorem in a proof of the
+existence of primeness triples.",1408.3383v3
+2014-11-03,Core-crust transition properties of neutron stars within systematically varied extended relativistic mean-field model,"The model dependence and the symmetry energy dependence of the core-crust
+transition properties for the neutron stars are studied using three different
+families of systematically varied extended relativistic mean field model.
+Several forces within each of the families are so considered that they yield
+wide variations in the values of the nuclear symmetry energy $a_{\rm sym}$ and
+its slope parameter $L$ at the saturation density. The core-crust transition
+density is calculated using a method based on random-phase-approximation. The
+core-crust transition density is strongly correlated, in a model independent
+manner, with the symmetry energy slope parameter evaluated at the saturation
+density. The pressure at the transition point dose not show any meaningful
+correlations with the symmetry energy parameters at the saturation density. At
+best, pressure at the transition point is correlated with the symmetry energy
+parameters and their linear combination evaluated at the some sub-saturation
+density. Yet, such correlations might not be model independent. The
+correlations of core-crust transition properties with the symmetry energy
+parameter are also studied by varying the symmetry energy within a single
+model. The pressure at the transition point is correlated once again with the
+symmetry energy parameter at the sub-saturation density.",1411.0427v1
+2015-02-16,Color Image Enhancement Using the lrgb Coordinates in the Context of Support Fuzzification,"Image enhancement is an important stage in the image-processing domain. The
+most known image enhancement method is the histogram equalization. This method
+is an automated one, and realizes a simultaneous modification for brightness
+and contrast in the case of monochrome images and for brightness, contrast,
+saturation and hue in the case of color images. Simple and efficient methods
+can be obtained if affine transforms within logarithmic models are used. A very
+important thing in the affine transform determination for color images is the
+coordinate system that is used for color space representation. Thus, the using
+of the RGB coordinates leads to a simultaneous modification of luminosity and
+saturation. In this paper using the lrgb perceptual coordinates one can define
+affine transforms, which allow a separated modification of luminosity l and
+saturation s (saturation being calculated with the component rgb in the
+chromatic plane). Better results can be obtained if partitions are defined on
+the image support and then the pixels are separately processed in each window
+belonging to the defined partition. Classical partitions frequently lead to the
+appearance of some discontinuities at the boundaries between these windows. In
+order to avoid all these drawbacks the classical partitions may be replaced by
+fuzzy partitions. Their elements will be fuzzy windows and in each of them
+there will be defined an affine transform induced by parameters using the fuzzy
+mean, fuzzy variance and fuzzy saturation computed for the pixels that belong
+to the analyzed window. The final image is obtained by summing up in a weight
+way the images of every fuzzy window.",1502.04499v1
+2015-12-23,Impact of sample geometry on the measurement of pressure-saturation curves: experiments and simulations,"In this paper we study the influence of sample geometry on the measurement of
+pressure-saturation relationships, by analyzing the drainage of a two-phase
+flow from a quasi-2D random porous medium. The medium is transparent, which
+allows for the direct visualization of the invasion pattern during flow, and is
+initially saturated with a viscous liquid (a dyed glycerol-water mix). As the
+pressure in the liquid is gradually reduced, air penetrates from an open inlet,
+displacing the liquid which leaves the system from an outlet on the opposite
+side. Pressure measurements and images of the flow are recorded and the
+pressure-saturation relationship is computed. We show that this relationship
+depends on the system size and aspect ratio. The effects of the system's
+boundaries on this relationship are measured experimentally and compared with
+simulations produced using an invasion percolation algorithm. The pressure
+build up at the beginning and end of the invasion process are particularly
+affected by the boundaries of the system whereas at the central part of the
+model (when the air front progresses far from these boundaries), the invasion
+happens at a statistically constant capillary pressure. These observations have
+led us to propose a much simplified pressure-saturation relationship, valid for
+systems that are large enough such that the invasion is not influenced by
+boundary effects. The properties of this relationship depend on the capillary
+pressure thresholds distribution, sample dimensions and average pore
+connectivity and its applications may be of particular interest for simulations
+of two-phase flow in large porous media.",1512.07415v1
+2016-03-17,Phase field modeling of partially saturated deformable porous media,"A poromechanical model of partially saturated deformable porous media is
+proposed based on a phase field approach at modeling the behavior of the
+mixture of liquid water and wet air, which saturates the pore space, the phase
+field being the saturation (ratio). While the standard retention curve is
+expected still to provide the intrinsic retention properties of the porous
+skeleton, depending on the porous texture, an enhanced description of surface
+tension between the wetting (liquid water) and the non-wetting (wet air) fluid,
+occupying the pore space, is stated considering a regularization of the phase
+field model based on an additional contribution to the overall free energy
+depending on the saturation gradient. The aim is to provide a more refined
+description of surface tension interactions.
+  An enhanced constitutive relation for the capillary pressure is established
+together with a suitable generalization of Darcy's law, in which the gradient
+of the capillary pressure is replaced by the gradient of the so-called
+generalized chemical potential, which also accounts for the \lq\lq
+force\rq\rq\, associated to the local free energy of the phase field model. A
+micro-scale heuristic interpretation of the novel constitutive law of capillary
+pressure is proposed, in order to compare the envisaged model with that one
+endowed with the concept of average interfacial area.
+  The considered poromechanical model is formulated within the framework of
+strain gradient theory in order to account for possible effects, at laboratory
+scale, of the micro-scale hydro-mechanical couplings between highly-localized
+flows (fingering) and localized deformations of the skeleton (fracturing).",1603.05564v1
+2017-01-03,Mixed one-bit compressive sensing with applications to overexposure correction for CT reconstruction,"When a measurement falls outside the quantization or measurable range, it
+becomes saturated and cannot be used in classical reconstruction methods. For
+example, in C-arm angiography systems, which provide projection radiography,
+fluoroscopy, digital subtraction angiography, and are widely used for medical
+diagnoses and interventions, the limited dynamic range of C-arm flat detectors
+leads to overexposure in some projections during an acquisition, such as
+imaging relatively thin body parts (e.g., the knee). Aiming at overexposure
+correction for computed tomography (CT) reconstruction, we in this paper
+propose a mixed one-bit compressive sensing (M1bit-CS) to acquire information
+from both regular and saturated measurements. This method is inspired by the
+recent progress on one-bit compressive sensing, which deals with only sign
+observations. Its successful applications imply that information carried by
+saturated measurements is useful to improve recovery quality. For the proposed
+M1bit-CS model, alternating direction methods of multipliers is developed and
+an iterative saturation detection scheme is established. Then we evaluate
+M1bit-CS on one-dimensional signal recovery tasks. In some experiments, the
+performance of the proposed algorithms on mixed measurements is almost the same
+as recovery on unsaturated ones with the same amount of measurements. Finally,
+we apply the proposed method to overexposure correction for CT reconstruction
+on a phantom and a simulated clinical image. The results are promising, as the
+typical streaking artifacts and capping artifacts introduced by saturated
+projection data are effectively reduced, yielding significant error reduction
+compared with existing algorithms based on extrapolation.",1701.00694v1
+2017-04-10,Saturation with chiral interactions and consequences for finite nuclei,"We explore the impact of nuclear matter saturation on the properties and
+systematics of finite nuclei across the nuclear chart. Using the ab initio
+in-medium similarity renormalization group (IM-SRG), we study ground-state
+energies and charge radii of closed-shell nuclei from $^4$He to $^{78}$Ni,
+based on a set of low-resolution two- and three-nucleon interactions that
+predict realistic saturation properties. We first investigate in detail the
+convergence properties of these Hamiltonians with respect to model-space
+truncations for both two- and three-body interactions. We find one particular
+interaction that reproduces well the ground-state energies of all closed-shell
+nuclei studied. As expected from their saturation points relative to this
+interaction, the other Hamiltonians underbind nuclei, but lead to a remarkably
+similar systematics of ground-state energies. Extending our calculations to
+complete isotopic chains in the $sd$ and $pf$ shells with the valence-space
+IM-SRG, the same interaction reproduces not only experimental ground states but
+two-neutron-separation energies and first excited $2^+$ states. We also
+calculate radii with the valence-space IM-SRG for the first time. Since this
+particular interaction saturates at too high density, charge radii are still
+too small compared with experiment. Except for this underprediction, the radii
+systematics is, however, well reproduced. Our results highlight the importance
+of nuclear matter as a theoretical benchmark for the development of
+next-generation chiral interactions.",1704.02915v1
+2018-09-15,"Equiangular lines, Incoherent sets and Quasi-symmetric designs","The absolute upper bound on the number of equiangular lines that can be found
+in $\mathbf{R}^d$ is $d(d+1)/2$. Examples of sets of lines that saturate this
+bound are only known to exist in dimensions $d=2,3,7$ or $23$. By considering
+the additional property of incoherence, we prove that there exists a set of
+equiangular lines that saturates the absolute bound and the incoherence bound
+if and only if $d=2,3,7$ or $23$. This allows us classify all tight spherical
+$5$-designs $X$ in $\mathbf{S}^{d-1}$, the unit sphere, with the property that
+there exists a set of $d$ points in $X$ whose pairwise inner products are
+positive.
+  For a given angle $\kappa$, there exists a relative upper bound on the number
+of equiangular lines in $\mathbf{R}^d$ with common angle $\kappa$. We prove
+that classifying sets of lines that saturate this bound along with the
+incoherence bound is equivalent to classifying certain quasi-symmetric designs,
+which are combinatorial designs with two block intersection numbers. Given a
+further natural assumption, we classify the known sets of lines that saturate
+these two bounds. This family comprises of the lines mentioned above and the
+maximal set of $16$ equiangular lines found in $\mathbf{R}^6$. There are
+infinitely many known sets of lines that saturate the relative bound, so this
+result is surprising. To shed some light on this, we identify the $E_8$ lattice
+with the projection onto an $8$-dimensional subspace of a sublattice of the
+Leech lattice defined by $276$ equiangular lines in $\mathbf{R}^{23}$. This
+identification leads us to observe a correspondence between sets of equiangular
+lines in small dimensions and the exceptional curves of del Pezzo surfaces.",1809.05739v3
+2019-01-14,Quantum Null Energy Condition and its (non)saturation in 2d CFTs,"We consider the Quantum Null Energy Condition (QNEC) for holographic
+conformal field theories in two spacetime dimensions (CFT$_2$). We show that
+QNEC saturates for all states dual to vacuum solutions of AdS$_3$ Einstein
+gravity, including systems that are far from thermal equilibrium. If the
+Ryu-Takayanagi surface encounters bulk matter QNEC does not need to be
+saturated, whereby we give both analytical and numerical examples. In
+particular, for CFT$_2$ with a global quench dual to AdS$_3$-Vaidya geometries
+we find a curious half-saturation of QNEC for large entangling regions. We also
+address order one corrections from quantum backreactions of a scalar field in
+AdS$_3$ dual to a primary operator of dimension $h$ in a large central charge
+expansion and explicitly compute both, the backreacted Ryu--Takayanagi surface
+part and the bulk entanglement contribution to EE and QNEC. At leading order
+for small entangling regions the contribution from bulk EE exactly cancels the
+contribution from the back-reacted Ryu-Takayanagi surface, but at higher orders
+in the size of the region the contributions are almost equal while QNEC is not
+saturated. For a half-space entangling region we find that QNEC is gapped by
+$h/4$ in the large $h$ expansion.",1901.04499v2
+2019-01-31,Scully-Lamb quantum laser model for parity-time-symmetric whispering-gallery microcavities: Gain saturation effects and non-reciprocity,"We use a non-Lindbladian master equation of the Scully-Lamb laser model for
+the analysis of light propagation in a parity-time symmetric photonic system
+composed of coupled active and passive whispering-gallery microresonators.
+Performing the semiclassical approximation, we obtain a set of two nonlinear
+coupled differential equations describing the time evolution of intracavity
+fields. These coupled equations are able to explain the experimentally-observed
+light non-reciprocity [Peng {\em et al.}, Nature Physics {\bf 10}, 394 (2014),
+Chang {\em et al.}, Nature Photonics {\bf 8}, 524 (2014)]. We show that this
+effect arises from the interplay between gain saturation in the active
+microcavity, intercavity coupling, and losses in the cavities. Additionally,
+using this approach, we study the effect of the gain saturation on exceptional
+points, i.e., exotic degeneracies in non-Hermitian systems. Namely, we
+demonstrate that the inclusion of gain saturation leads to a modification of
+the exceptional points in the presence of intense intracavity fields. The
+Scully-Lamb master equation for systems of coupled optical structures, as
+proposed and applied here, constitutes a promising tool for the study of
+quantum optical effects in coupled systems with losses, gain, and gain
+saturation.",1901.11421v3
+2019-04-24,Saturation momentum scale extracted from semi-inclusive transverse spectra in high-energy pp collisions,"Geometric scaling is well confirmed for transverse momentum distributions
+observed in proton-proton collisions at LHC energies. We introduced
+multiplicity dependence on a saturation momentum of the geometrical scaling,
+assuming the scaling holds for semi-inclusive distributions as well as for
+inclusive distributions. The saturation momentum is usually given by Bjorken's
+$x$ variable, but redefinition of the scaling variable can make the saturation
+momentum a function of collision energy $W$. We treat the energy as a free
+parameter (denoted $W^*$ to distinguish it from $W$) and associate the
+energy-dependent saturation momentum $Q_{\rm sat}(W^*)$ with particle number
+density. By using $Q_{\rm sat}(W^*)$ for a scaling variable $\tau$, we show
+semi-inclusive distributions can be geometrically scaled. i.e., all
+semi-inclusive spectra observed at $W$=0.90, 2.76 and 7.00 TeV overlap one
+universal function. The particle density dependences of mean transverse
+momentum $\langle p_{\rm T} \rangle$ for LHC energies scales in terms of
+$Q_{\rm sat}(W^*)$. Furthermore, our model explains a scaling property of
+event-by-event $p_{\rm T}$ fluctuation measure $\sqrt{C_m}/\langle p_{\rm
+T}\rangle$ at LHC energies for pp collisions, where $C_m$ is two-particle
+transverse momentum correlator. Our analysis of the $p_{\rm T}$ fluctuation
+makes possible to evaluate a non-perturbative coefficient of the gluon
+correlation function.",1904.10823v2
+2020-01-13,Interactive Visualization of Saturation Attempts in Vampire,"Many applications of formal methods require automated reasoning about system
+properties, such as system safety and security. To improve the performance of
+automated reasoning engines, such as SAT/SMT solvers and first-order theorem
+prover, it is necessary to understand both the successful and failing attempts
+of these engines towards producing formal certificates, such as logical proofs
+and/or models. Such an analysis is challenging due to the large number of
+logical formulas generated during proof/model search. In this paper we focus on
+saturation-based first-order theorem proving and introduce the SATVIS tool for
+interactively visualizing saturation-based proof attempts in first-order
+theorem proving. We build SATVIS on top of the world-leading theorem prover
+VAMPIRE, by interactively visualizing the saturation attempts of VAMPIRE in
+SATVIS. Our work combines the automatic layout and visualization of the
+derivation graph induced by the saturation attempt with interactive
+transformations and search functionality. As a result, we are able to analyze
+and debug (failed) proof attempts of VAMPIRE. Thanks to its interactive
+visualisation, we believe SATVIS helps both experts and non-experts in theorem
+proving to understand first-order proofs and analyze/refine failing proof
+attempts of first-order provers.",2001.04100v1
+2020-05-15,Single Image HDR Reconstruction Using a CNN with Masked Features and Perceptual Loss,"Digital cameras can only capture a limited range of real-world scenes'
+luminance, producing images with saturated pixels. Existing single image high
+dynamic range (HDR) reconstruction methods attempt to expand the range of
+luminance, but are not able to hallucinate plausible textures, producing
+results with artifacts in the saturated areas. In this paper, we present a
+novel learning-based approach to reconstruct an HDR image by recovering the
+saturated pixels of an input LDR image in a visually pleasing way. Previous
+deep learning-based methods apply the same convolutional filters on
+well-exposed and saturated pixels, creating ambiguity during training and
+leading to checkerboard and halo artifacts. To overcome this problem, we
+propose a feature masking mechanism that reduces the contribution of the
+features from the saturated areas. Moreover, we adapt the VGG-based perceptual
+loss function to our application to be able to synthesize visually pleasing
+textures. Since the number of HDR images for training is limited, we propose to
+train our system in two stages. Specifically, we first train our system on a
+large number of images for image inpainting task and then fine-tune it on HDR
+reconstruction. Since most of the HDR examples contain smooth regions that are
+simple to reconstruct, we propose a sampling strategy to select challenging
+training patches during the HDR fine-tuning stage. We demonstrate through
+experimental results that our approach can reconstruct visually pleasing HDR
+results, better than the current state of the art on a wide range of scenes.",2005.07335v1
+2020-06-15,Feature Space Saturation during Training,"We propose layer saturation - a simple, online-computable method for
+analyzing the information processing in neural networks. First, we show that a
+layer's output can be restricted to the eigenspace of its variance matrix
+without performance loss. We propose a computationally lightweight method for
+approximating the variance matrix during training. From the dimension of its
+lossless eigenspace we derive layer saturation - the ratio between the
+eigenspace dimension and layer width. We show that saturation seems to indicate
+which layers contribute to network performance. We demonstrate how to alter
+layer saturation in a neural network by changing network depth, filter sizes
+and input resolution. Furthermore, we show that well-chosen input resolution
+increases network performance by distributing the inference process more evenly
+across the network.",2006.08679v5
+2020-12-15,Edge-Minimum Saturated k-Planar Drawings,"For a class $\mathcal{D}$ of drawings of loopless (multi-)graphs in the
+plane, a drawing $D \in \mathcal{D}$ is \emph{saturated} when the addition of
+any edge to $D$ results in $D' \notin \mathcal{D}$ - this is analogous to
+saturated graphs in a graph class as introduced by Tur\'an (1941) and
+Erd\H{o}s, Hajnal, and Moon (1964). We focus on $k$-planar drawings, that is,
+graphs drawn in the plane where each edge is crossed at most $k$ times, and the
+classes $\mathcal{D}$ of all $k$-planar drawings obeying a number of
+restrictions, such as having no crossing incident edges, no pair of edges
+crossing more than once, or no edge crossing itself. While saturated $k$-planar
+drawings are the focus of several prior works, tight bounds on how sparse these
+can be are not well understood. We establish a generic framework to determine
+the minimum number of edges among all $n$-vertex saturated $k$-planar drawings
+in many natural classes. For example, when incident crossings, multicrossings
+and selfcrossings are all allowed, the sparsest $n$-vertex saturated $k$-planar
+drawings have $\frac{2}{k - (k \bmod 2)} (n-1)$ edges for any $k \geq 4$, while
+if all that is forbidden, the sparsest such drawings have
+$\frac{2(k+1)}{k(k-1)}(n-1)$ edges for any $k \geq 6$.",2012.08631v3
+2021-07-13,Attention-Guided Progressive Neural Texture Fusion for High Dynamic Range Image Restoration,"High Dynamic Range (HDR) imaging via multi-exposure fusion is an important
+task for most modern imaging platforms. In spite of recent developments in both
+hardware and algorithm innovations, challenges remain over content association
+ambiguities caused by saturation, motion, and various artifacts introduced
+during multi-exposure fusion such as ghosting, noise, and blur. In this work,
+we propose an Attention-guided Progressive Neural Texture Fusion (APNT-Fusion)
+HDR restoration model which aims to address these issues within one framework.
+An efficient two-stream structure is proposed which separately focuses on
+texture feature transfer over saturated regions and multi-exposure tonal and
+texture feature fusion. A neural feature transfer mechanism is proposed which
+establishes spatial correspondence between different exposures based on
+multi-scale VGG features in the masked saturated HDR domain for discriminative
+contextual clues over the ambiguous image areas. A progressive texture blending
+module is designed to blend the encoded two-stream features in a multi-scale
+and progressive manner. In addition, we introduce several novel attention
+mechanisms, i.e., the motion attention module detects and suppresses the
+content discrepancies among the reference images; the saturation attention
+module facilitates differentiating the misalignment caused by saturation from
+those caused by motion; and the scale attention module ensures texture blending
+consistency between different coder/decoder scales. We carry out comprehensive
+qualitative and quantitative evaluations and ablation studies, which validate
+that these novel modules work coherently under the same framework and
+outperform state-of-the-art methods.",2107.06211v1
+2021-11-30,AutoDrop: Training Deep Learning Models with Automatic Learning Rate Drop,"Modern deep learning (DL) architectures are trained using variants of the SGD
+algorithm that is run with a $\textit{manually}$ defined learning rate
+schedule, i.e., the learning rate is dropped at the pre-defined epochs,
+typically when the training loss is expected to saturate. In this paper we
+develop an algorithm that realizes the learning rate drop
+$\textit{automatically}$. The proposed method, that we refer to as AutoDrop, is
+motivated by the observation that the angular velocity of the model parameters,
+i.e., the velocity of the changes of the convergence direction, for a fixed
+learning rate initially increases rapidly and then progresses towards soft
+saturation. At saturation the optimizer slows down thus the angular velocity
+saturation is a good indicator for dropping the learning rate. After the drop,
+the angular velocity ""resets"" and follows the previously described pattern - it
+increases again until saturation. We show that our method improves over SOTA
+training approaches: it accelerates the training of DL models and leads to a
+better generalization. We also show that our method does not require any extra
+hyperparameter tuning. AutoDrop is furthermore extremely simple to implement
+and computationally cheap. Finally, we develop a theoretical framework for
+analyzing our algorithm and provide convergence guarantees.",2111.15317v2
+2022-03-24,Investigating saturation effects and the virtual pion in leading neutron events at HERA with the dipole model,"We investigate events with very forward neutrons in $ep$ collisions at HERA
+using impact parameter dependent colour dipole models with and without
+saturation. This is the first study of the leading neutron process deploying
+these models. The model predictions are compared with the available HERA
+measurements for $6<Q^2<100$~GeV$^2$, $70<W<245$~GeV. Our analysis shows that
+the models exhibit Feynman scaling, independent of $Q^2$. Our results
+demonstrate that the $W$ and $Q^2$ dependence of the cross section is
+independent of the presence of a forward neutron as predicted by the limiting
+fragmentation hypothesis, which is a consequence of Feynman scaling itself. We
+infer that the HERA leading neutron production inclusive data is insensitive to
+saturation physics and these cross sections may not be able to distinguish
+gluon saturation effects in future $ep$ colliders. We provide a good
+description of the leading neutron structure function $F_2^{LN}$ at small $x$
+using an assumption that the small-$x$ structure of protons and pions is
+universal up to a normalisation. We also show that the observables in the
+exclusive diffractive measurements with a vector meson in the final state are
+more sensitive to saturation physics at small $x$ than inclusive measurements.
+At last, we provide a prediction for the $\hat t$ spectrum in exclusive vector
+meson production in the dipole model using Yukawa theory to model the virtual
+pion's spatial wave function.",2203.13314v3
+2022-07-11,Computational coupled large-deformation periporomechanics for dynamic failure and fracturing in variably saturated porous media,"The large-deformation mechanics and multiphysics of continuous or fracturing
+partially saturated porous media under static and dynamic loads are significant
+in engineering and science. This article is devoted to a computational coupled
+large-deformation periporomechanics paradigm assuming passive air pressure for
+modeling dynamic failure and fracturing in variably saturated porous media. The
+coupled governing equations for bulk and fracture material points are
+formulated in the current/deformed configuration through the updated
+Lagrangian-Eulerian framework. It is hypothesized that the horizon of a mixed
+material point remains spherical, and its neighbor points are determined in the
+current configuration. As a significant contribution, the mixed
+interface/phreatic material points near the phreatic line are explicitly
+considered for modeling the transition from partial to full saturation (vice
+versa) through the mixed peridynamic state concept. We have formulated the
+coupled constitutive correspondence principle and stabilization scheme in the
+updated Lagrangian-Eulerian framework for bulk and interface points. We
+numerically implement the coupled large deformation periporomechanics through a
+fully implicit fractional-step algorithm in time and a hybrid updated
+Lagrangian-Eulerian meshfree method in space. Numerical examples are presented
+to validate the implemented stabilized computational coupled large deformation
+periporomechanics and demonstrate its efficacy and robustness in modeling
+dynamic failure and fracturing in variably saturated porous media.",2207.04580v1
+2022-08-27,Beyond DGLAP improved saturation model,"We present a modification of the DGLAP improved saturation model with respect
+to the nonlinear correction (NLC). The GLR-MQ improved saturation model is
+considered by employing the parametrization of proton structure function due to
+the Laplace transforms method, which preserves its behavior success in the low
+and high $Q^{2}$ regions. We show that the geometric scaling holds for the
+GLR-MQ improved model in a wide kinematic region $rQ_{s}$. These results are
+comparable with other models in a wide kinematic region $rQ_{s}$. The behavior
+of the dipole cross sections, with respect to the GLR-MQ improved saturation
+model, are comparable with the Color Glass Condensate (CGC) model. The model
+describes the dipole cross sections in the inclusive and diffractive processes.
+We also compare the nonlinear corrections to the impact-parameter dependent
+saturation (IP-Sat) model with the impact-parameter dependent color glass
+condensate (b-CGC) dipole model. Finally, we consider the linear and nonlinear
+corrections to the IP Non-Sat model. These results provide a benchmark for
+further investigation of QCD at small $x$ in future experiments such as the
+Large Hadron Collider and Future Circular Collider projects.",2208.13037v4
+2023-04-14,SMAE: Few-shot Learning for HDR Deghosting with Saturation-Aware Masked Autoencoders,"Generating a high-quality High Dynamic Range (HDR) image from dynamic scenes
+has recently been extensively studied by exploiting Deep Neural Networks
+(DNNs). Most DNNs-based methods require a large amount of training data with
+ground truth, requiring tedious and time-consuming work. Few-shot HDR imaging
+aims to generate satisfactory images with limited data. However, it is
+difficult for modern DNNs to avoid overfitting when trained on only a few
+images. In this work, we propose a novel semi-supervised approach to realize
+few-shot HDR imaging via two stages of training, called SSHDR. Unlikely
+previous methods, directly recovering content and removing ghosts
+simultaneously, which is hard to achieve optimum, we first generate content of
+saturated regions with a self-supervised mechanism and then address ghosts via
+an iterative semi-supervised learning framework. Concretely, considering that
+saturated regions can be regarded as masking Low Dynamic Range (LDR) input
+regions, we design a Saturated Mask AutoEncoder (SMAE) to learn a robust
+feature representation and reconstruct a non-saturated HDR image. We also
+propose an adaptive pseudo-label selection strategy to pick high-quality HDR
+pseudo-labels in the second stage to avoid the effect of mislabeled samples.
+Experiments demonstrate that SSHDR outperforms state-of-the-art methods
+quantitatively and qualitatively within and across different datasets,
+achieving appealing HDR visualization with few labeled samples.",2304.06914v1
+2023-08-28,Effect of fiber curvature on gas diffusion layer two-phase dynamics of a proton exchange membrane fuel cell,"The dynamics of two-phase flow within the cathode of a proton exchange
+membrane fuel cell, particularly in Gas Diffusion Layers (GDLs) with varying
+fiber curvatures, remain underexplored. Using a periodic surface model, we
+stochastically reconstruct three GDL types with different fiber curvatures,
+incorporating vital parameters derived from a physical GDL. Considering the
+randomness in reconstruction, the structure generation process is iterated four
+times for each GDL type, enabling an ensemble average analysis. Pore network
+models are adopted to reveal disparities in these GDL porous structures. The
+subsequent two-phase simulations are conducted to explore liquid transport
+through these GDLs and interfaces to assembled gas channels. Time-varying GDL
+total, local water saturation, and capillary pressure are investigated. Results
+show stochastic reconstructions exhibit similar frequency peak ranges in pore
+and throat diameters, and coordination numbers, but diverge from the physical
+GDL. Bigger fiber curvature tends to enhance pore network connectivity by
+increasing smaller pores, leading to heightened water saturation and capillary
+pressure. Straight-fiber GDLs, compared to curved-fiber GDLs, show greater
+potential proximity to the physical GDL in terms of overall water saturation
+and capillary pressure but are also accompanied by increased uncertainty.
+Despite similar layer porosity, water saturation in the same layer of all
+samples differs increasingly from the inlet to the outlet. Water breakthrough
+and detachment near the GDL can induce significant water saturation instability
+at the GDL and gas channel interface. Detached droplets in gas channels
+connected with straight-fiber GDLs exhibit larger sizes and slower movement
+than those in channels assembled with curved-fiber GDLs. These findings can be
+utilized in future GDL design and optimization.",2308.14539v2
+2023-12-18,Incoherent ${\rm J}/ψ$ production at large $|t|$ identifies the onset of saturation at the LHC,"We predict that the onset of gluon saturation can be uniquely identified
+using incoherent ${\rm J}/\psi$ production in Pb$\unicode{x2013}$Pb collisions
+at currently accessible energies of the LHC. The diffractive incoherent
+photo-production of a ${\rm J}/\psi$ vector meson off a hadron provides
+information on the partonic structure of the hadron. Within the Good-Walker
+approach it specifically measures the variance over possible target
+configurations of the hadronic colour field. For this process then, gluon
+saturation sets in when the cross section reaches a maximum, as a function of
+the centre-of-mass energy of the photon-hadron system ($W$), and then
+decreases. We benchmark the energy-dependent hot-spot model against data from
+HERA and the LHC and demonstrate a good description of the available data. We
+show that the study of the energy dependence of the incoherent production of
+${\rm J}/\psi$ allows us to pinpoint the onset of saturation effects by
+selecting the region of Mandelstam-$t$ around 1 GeV$^2$ where the contribution
+of hot spots is dominant. We predict the onset of saturation in a Pb target to
+occur for $W$ around a few hundred GeV. This can be measured with current data
+in ultra-peripheral Pb$\unicode{x2013}$Pb collisions at the LHC.",2312.11320v2
+2024-02-16,Superradiant pulse saturation in a Free Electron Laser,"A study is made of the saturation mechanism of a single superradiant spike of
+radiation in a Free Electron Laser. A one-dimensional (1D) computer model is
+developed using the Puffin, un-averaged FEL simulation code, which allows
+sub-radiation wavelength evolution of both the spike radiation field and the
+electron dynamics to be modelled until the highly non-linear saturation process
+of the spike is observed. Animations of the process from the start to the end
+of the interaction are available. The resultant saturated spike duration is at
+the sub-wavelength scale and has a broad spectrum. The electrons passing
+through the spike can both lose and gain energy many times greater than that of
+the normal non-pulsed FEL interaction. A saturation mechanism is proposed and
+tested via a simple analysis of the 1D FEL equations. The scaling results of
+the analysis are seen to be in good agreement with the numerical results. A
+simple model of three dimensional diffraction effects of the radiation is
+applied to the results of the 1D simulations. This greatly reduces longer
+wavelengths of the power spectrum, which are seen to be emitted mainly after
+the electrons have propagated through the spike, and is seen to be in
+qualitative agreement with recent experimental results.",2402.11026v1
+2024-02-18,Saturability of the Quantum Cramér-Rao Bound in Multiparameter Quantum Estimation at the Single-Copy Level,"The quantum Cram\'{e}r-Rao bound (QCRB) as the ultimate lower bound for
+precision in quantum parameter estimation is only known to be saturable in the
+multiparameter setting in special cases and under conditions such as full or
+average commutavity of the symmetric logarithmic derivatives (SLDs) associated
+with the parameters. Moreover, for general mixed states, collective
+measurements over infinitely many identical copies of the quantum state are
+generally required to attain the QCRB. In the important and experimentally
+relevant single-copy scenario, a necessary condition for saturating the QCRB in
+the multiparameter setting for general mixed states is the so-called partial
+commutativity condition on the SLDs. However, it is not known if this condition
+is also sufficient. This paper establishes necessary and sufficient conditions
+for saturability of the multiparameter QCRB in the single-copy setting in terms
+of the commutativity of a set of projected SLDs and the existence of a unitary
+solution to a system of nonlinear partial differential equations. New necessary
+conditions that imply partial commutativity are also obtained, which together
+with another condition become sufficient. Moreover, when the sufficient
+conditions are satisfied an optimal measurement saturating the QCRB can be
+chosen to be projective and explicitly characterized. An example is developed
+to illustrate the case of a multiparameter quantum state where the conditions
+derived herein are satisfied and can be explicitly verified.",2402.11567v3
+2022-09-09,Magnetically confined mountains on accreting neutron stars with multipole magnetic fields,"Magnetically confined mountains on accreting neutron stars are candidates for
+producing continuous gravitational waves. We formulate a magnetically confined
+mountain on a neutron star with strong multipole magnetic fields and obtain
+some sequences of numerical solutions. We find that the mass ellipticity of the
+mountain increases by one order of magnitude if the neutron star has strong
+multipole magnetic fields. As matter accretes on to the magnetic pole, the size
+of the mountain increases and the magnetic fields are buried. If the neutron
+star has a dipole magnetic field, the dipole magnetic field is buried and
+transformed into multipole components. By contrast, if the neutron star has
+both dipole and strong multipole magnetic fields, the multipole magnetic fields
+are buried and transformed into a negative dipole component. We also calculate
+magnetically confined mountains with toroidal magnetic fields and find that the
+ellipticity becomes slightly smaller when the mountain has toroidal magnetic
+fields. If the multipole magnetic fields are buried, they sustain the intense
+toroidal magnetic field near the stellar surface, and the ratio of the toroidal
+magnetic field to the poloidal magnetic field is close to 100. The hidden
+strong toroidal magnetic fields are sustained by the buried multipole magnetic
+fields.",2209.04352v1
+2001-06-21,Instantons in the Saturation Environment,"We show that instanton calculations in QCD become theoretically well defined
+in the gluon saturation environment which suppresses large size instantons. The
+effective cutoff scale is determined by the inverse of the saturation scale. We
+concentrate on two most important cases: the small-x tail of a gluon
+distribution of a high energy hadron or a large nucleus and the central
+rapidity region in a high energy hadronic or heavy ion collision. In the
+saturation regime the gluon density in a single large ultrarelativistic nucleus
+is high and gluonic fields are given by the classical solutions of the
+equations of motion. We show that these strong classical fields do not affect
+the density of instantons in the nuclear wave function compared to the
+instanton density in the vacuum. A classical solution with non-trivial
+topological charge is found for the gluon field of a single nucleus at the
+lowest order in the instanton perturbation theory. In the case of
+ultrarelativistic heavy ion collisions a strong classical gluonic field is
+produced in the central rapidity region. We demonstrate that this field
+introduces a suppression factor of exp{-c \rho^4 Q_s^4 / [8 \alpha^2 N_c (Q_s
+\tau)^2]} in the instanton size distribution, where Q_s is the saturation scale
+of both (identical) nuclei, \tau is the proper time and c = 1 is the gluon
+liberation coefficient. This factor suggests that gluonic saturation effects at
+the early stages of nuclear collisions regulate the instanton size distribution
+in the infrared region and make the instanton density finite by suppressing
+large size instantons.",0106248v2
+2006-01-17,On correlations and discreteness in non-linear QCD evolution,"We consider modifications of the standard non-linear QCD evolution in an
+attempt to account for some of the missing ingredients discussed recently, such
+as correlations, discreteness in gluon emission and Pomeron loops. The
+evolution is numerically performed using the Balitsky-Kovchegov equation on
+individual configurations defined by a given initial value of the saturation
+scale, for reduced rapidities $y=(\alpha_s N_c/\pi) Y<10$. We consider the
+effects of averaging over configurations as a way to implement correlations,
+using three types of Gaussian averaging around a mean saturation scale.
+Further, we heuristically mimic discreteness in gluon emission by considering a
+modified evolution in which the tails of the gluon distributions are cut-off.
+The approach to scaling and the behavior of the saturation scale with rapidity
+in these modified evolutions are studied and compared with the standard
+mean-field results. For the large but finite values of rapidity explored, no
+strong quantitative difference in scaling for transverse momenta around the
+saturation scale is observed. At larger transverse momenta, the influence of
+the modifications in the evolution seems most noticeable in the first steps of
+the evolution. No influence on the rapidity behavior of the saturation scale
+due to the averaging procedure is found. In the cut-off evolution the rapidity
+evolution of the saturation scale is slowed down and strongly depends on the
+value of the cut-off. Our results stress the need to go beyond simple
+modifications of evolution by developing proper theoretical tools that
+implement such recently discussed ingredients.",0601132v3
+2015-05-06,On upper bounds on the smallest size of a saturating set in a projective plane,"In a projective plane $\Pi _{q}$ (not necessarily Desarguesian) of order $q,$
+a point subset $S$ is saturating (or dense) if any point of $\Pi _{q}\setminus
+S$ is collinear with two points in$~S$. Using probabilistic methods, the
+following upper bound on the smallest size $ s(2,q)$ of a saturating set in
+$\Pi _{q}$ is proved: \begin{equation*} s(2,q)\leq 2\sqrt{(q+1)\ln
+(q+1)}+2\thicksim 2\sqrt{q\ln q}. \end{equation*} We also show that for any
+constant $c\ge 1$ a random point set of size $k$ in $\Pi _{q}$ with $
+2c\sqrt{(q+1)\ln(q+1)}+2\le k<\frac{q^{2}-1}{q+2}\thicksim q$ is a saturating
+set with probability greater than $1-1/(q+1)^{2c^{2}-2}.$ Our probabilistic
+approach is also applied to multiple saturating sets. A point set $S\subset
+\Pi_{q}$ is $(1,\mu)$-saturating if for every point $Q$ of $\Pi _{q}\setminus
+S$ the number of secants of $S$ through $Q$ is at least $\mu $, counted with
+multiplicity. The multiplicity of a secant $ \ell $ is computed as
+${\binom{{\#(\ell \,\cap S)}}{{2}}}.$ The following upper bound on the smallest
+size $s_{\mu }(2,q)$ of a $(1,\mu)$-saturating set in $\Pi_{q}$ is proved:
+\begin{equation*} s_{\mu }(2,q)\leq 2(\mu +1)\sqrt{(q+1)\ln (q+1)}+2\thicksim
+2(\mu +1)\sqrt{ q\ln q}\,\text{ for }\,2\leq \mu \leq \sqrt{q}. \end{equation*}
+  By using inductive constructions, upper bounds on the smallest size of a
+saturating set (as well as on a $(1,\mu)$-saturating set) in the projective
+space $PG(N,q)$ are obtained.
+  All the results are also stated in terms of linear covering codes.",1505.01426v3
+2019-04-22,CEST MR-Fingerprinting: practical considerations and insights for acquisition schedule design and improved reconstruction,"Purpose: To understand the influence of various acquisition parameters on the
+ability of CEST MR-Fingerprinting (MRF) to discriminate different chemical
+exchange parameters and to provide tools for optimal acquisition schedule
+design and parameter map reconstruction. Methods: Numerical simulations were
+conducted using a parallel-computing implementation of the Bloch-McConnell
+equations, examining the effect of TR, TE, flip-angle, water T$_{1}$ and
+T$_{2}$, saturation-pulse duration, power, and frequency on the discrimination
+ability of CEST-MRF. A modified Euclidean-distance matching metric was
+evaluated and compared to traditional dot-product matching. L-Arginine phantoms
+of various concentrations and pH were scanned at 4.7T and the results compared
+to numerical findings. Results: Simulations for dot-product matching
+demonstrated that the optimal flip-angle and saturation times are 30$^{\circ}$
+and 1100 ms, respectively. The optimal maximal saturation power was 3.4 $\mu$T
+for concentrated solutes with a slow exchange-rate, and 5.2 $\mu$T for dilute
+solutes with medium-to-fast exchange-rates. Using the Euclidean-distance
+matching metric, much lower maximum saturation powers were required (1.6 and
+2.4 $\mu$T, respectively), with a slightly longer saturation time (1500 ms) and
+90$^{\circ}$ flip-angle. For both matching metrics, the discrimination ability
+increased with the repetition time. The experimental results were in agreement
+with simulations, demonstrating that more than a 50% reduction in scan-time can
+be achieved by Euclidean-distance-based matching. Conclusion: Optimization of
+the CEST-MRF acquisition schedule is critical for obtaining the best exchange
+parameter accuracy. The use of Euclidean-distance-based matching of signal
+trajectories simultaneously improved the discrimination ability and reduced the
+scan time and maximal saturation power required.",1904.09732v1
+2019-11-20,Moist Shallow Water Response to Tropical Forcing: Initial Value Problems,"The response of a spherical moist shallow water system to tropical imbalances
+in the presence of inhomogeneous saturation fields is examined. While the
+initial moist response is similar to the dry reference run, albeit with a
+reduced equivalent depth, the long time solution depends quite strikingly on
+the nature of the saturation field. For a saturation field that only depends on
+latitude, specifically, one with a peak at the equator and falls off
+meridionally in both hemispheres, height imbalances adjust to large-scale,
+low-frequency westward propagating modes. When the background saturation
+environment is also allowed to vary with longitude, in addition to a westward
+quadrupole, there is a distinct eastward propagating response at long times.
+The nature of this eastward propagating mode is well described by moist
+potential vorticity conservation and it consists of wave packets that arc out
+to midlatitudes and return to the tropics and are predominantly rotational in
+character. In all moist cases, initially formed Kelvin waves decay, and this
+appears to be tied to the off-equatorial organization of moisture anomalies by
+rotational modes. Many of these basic features carry over to the response in
+the presence of realistic saturation fields derived from reanalysis based
+precipitable water. In boreal summer, long time eastward response is restricted
+to northern hemisphere and takes the form of a wavetrain that passes over
+Indian landmass into the subtropics, reaching across the Pacific to North
+America. In boreal winter, the eastward mode consists of a subtropically
+confined rotational quadrupole along with midlatitudinal disturbances. Thus, in
+addition to circumnavigating westward Rossby waves, slow eastward propagating
+modes appear to be a robust feature of the shallow water system with
+interactive moisture in the presence of saturation fields that vary with
+latitude and longitude.",1911.08811v3
+2020-11-10,Saturated fusion systems on $p$-groups of maximal class,"For a prime number $p$, a finite $p$-group of order $p^n$ has maximal class
+if it has nilpotency class $n-1$. Here we examine saturated fusion systems on
+maximal class $p$-groups and, in particular, we describe all the reduFor a
+prime number $p$, a finite $p$-group of order $p^n$ has maximal class if and
+only if it has nilpotency class $n-1$. Here we examine saturated fusion systems
+$\mathcal F$ on maximal class $p$-groups $S$ of order at least $p^4$. The
+Alperin-Goldschmidt Theorem for saturated fusion systems yields that $\mathcal
+F$ is entirely determined by the $\mathcal F$-automorphisms of its $\mathcal
+F$-essential subgroups and of $S$ itself. If an $\mathcal F$-essential subgroup
+either has order $p^2$ or is non-abelian of order $p^3$, then it is called an
+$\mathcal F$-pearl. The facilitating and technical theorem in this work shows
+that an $\mathcal F$-essential subgroup is either an $\mathcal F$-pearl, or one
+of two explicitly determined maximal subgroups of $S$. This result is easy to
+prove if $S$ is a $2$-group and can be read from the work of D'\iaz, Ruiz, and
+Viruel together with that of Parker and Semeraro when $p=3$. The main
+contribution is for $p \ge 5$ as in this case there is no classification of the
+maximal class $p$-groups.
+  The main Theorem describes all the reduced saturated fusion systems on a
+maximal class $p$-group of order at least $p^4$ and follows from two more
+extensive theorems. These two theorems describe all saturated fusion systems,
+not restricting to the reduced ones for example, on exceptional and
+non-exceptional maximal class $p$-groups respectively. As a corollary, we have
+the easy to remember result that states that, if $O_p(\mathcal F)=1$, then
+either $\mathcal F$ has $\mathcal F$-pearls or $S$ is isomorphic to a Sylow
+$p$-subgroup of $\mathrm G_2(p)$ with $p\ge 5$ and the fusion systems are
+explicitly described.",2011.05011v2
+2023-03-06,Monitoring Fluid Saturation in Reservoirs Using Time-Lapse Full-Waveform Inversion,"Monitoring the rock-physics properties of the subsurface is of great
+importance for reservoir management. For either oil and gas applications or CO2
+storage, seismic data are a valuable source of information for tracking changes
+in elastic properties which can be related to fluids saturation and pressure
+changes within the reservoir. Changes in elastic properties can be estimated
+with time-lapse full-waveform inversion. Monitoring rock-physics properties,
+such as saturation, with time-lapse full-waveform inversion is usually a
+two-step process: first, elastic properties are estimated with full-waveform
+inversion, then, the rock-physics properties are estimated with rock-physics
+inversion. However, multiparameter time-lapse full-waveform inversion is prone
+to crosstalk between parameter classes across different vintages. This leads to
+leakage from one parameter class to another, which, in turn, can introduce
+large errors in the estimated rock-physics parameters. To avoid inaccuracies
+caused by crosstalk and the two-step inversion strategy, we reformulate
+time-lapse full-waveform inversion to estimate directly the changes in the
+rock-physics properties. Using Gassmann's model, we adopt a new
+parameterization containing porosity, clay content, and water saturation. In
+the context of reservoir monitoring, changes are assumed to be induced by fluid
+substitution only. The porosity and clay content can thus be kept constant
+during time-lapse inversion. We compare this parameterization with the usual
+density-velocity parameterization for different benchmark models. Results
+indicate that the proposed parameterization eliminates crosstalk between
+parameters of different vintages, leading to more accurate estimation of
+saturation changes. We also show that using the parameterization based on
+porosity, clay content, and water saturation, the elastic changes can be
+monitored more accurately.",2303.03136v3
+2023-04-04,Modulational instability in $\cal{PT}$-symmetric Bragg grating structures with saturable nonlinearity,"We investigate the nontrivial characteristics of modulational instability
+(MI) in a system of Bragg gratings with saturable nonlinearity. We also
+introduce an equal amount of gain and loss into the existing system which gives
+rise to an additional degree of freedom, thanks to the concept of $\cal PT$-
+symmetry. We obtain the nonlinear dispersion relation of the saturable model
+and discover that such dispersion relations for both the conventional and $\cal
+PT$- symmetric cases contradict with the conventional Kerr and saturable
+systems by not displaying the typical signature of loop formation in either the
+upper branch or lower branch of the curve drawn against the wavenumber and
+detuning parameter. We then employ a standard linear stability analysis in
+order to study the MI dynamics of the continuous waves perturbed by an
+infinitesimal perturbation. The main objective of this paper is twofold. We
+first investigate the dynamics of the MI gain spectrum at the top and bottom of
+the photonic bandgap followed by a comprehensive analysis carried out in the
+anomalous and normal dispersion regimes. As a result, this perturbed system
+driven by the saturable nonlinearity and gain/loss yields a variety of
+instability spectra, which include the conventional side bands, monotonically
+increasing gain, the emergence of a single spectrum in either of the Stokes
+wavenumber region, and so on. In particular, we observe a remarkably peculiar
+spectrum, which is caused predominantly by the system parameter though the
+perturbation wavenumber boosts the former. We also address the impact of all
+the physical parameters considered in the proposed model which include coupling
+coefficient, dispersion parameter, and saturable nonlinearity on the phenomenon
+of MI for different $\cal PT$- symmetric regimes ranging from unbroken to
+broken one in greater detail.",2304.01927v1
+2022-10-31,Superconducting Magnet System Concept with a Mechanical Energy Transfer in the Magnetic Field,"There is an interest to design superconducting magnet systems working in a
+persistent current mode. These systems continuously generate magnetic field
+with disconnected power source working like permanent magnet devices. In this
+paper proposed a magnet system concept based on the direct mechanical energy
+transfer in the magnetic field. Short circuited superconducting coils do not
+have current leads and power source. To pump the mechanical energy in the
+superconducting coil used a magnetizer which magnetically coupled with the
+coil. The mechanical removing the magnetizer from the magnet induces a
+persistent current in the superconducting coil which generates the magnetic
+field. Iron dominated magnet system concept was investigated using OPERA3d code
+which confirmed a visibility of proposed approach.",2211.00102v1
+2014-06-25,Transforming magnets,"Based on the form-invariant of Maxwell's equations under coordinate
+transformations, we extend the theory of transformation optics to
+transformation magneto-statics, which can design magnets through coordinate
+transformations. Some novel DC magnetic field illusions created by magnets
+(e.g. shirking magnets, cancelling magnets and overlapping magnets) are
+designed and verified by numerical simulations. Our research will open a new
+door to designing magnets and controlling DC magnetic fields.",1406.6512v1
+1995-05-23,"Isotropy, homogeneity and dipole saturation","A distribution of points that satisfies the property of local isotropy is not
+necessarily homogeneous: homogeneity is implied by the condition of local
+isotropy together with the assumption of analyticity or regularity. Here we
+show that the evidence of dipole saturation in galaxies (and clusters)
+catalogues, together with a monotone growth of the monopole, is an evidence of
+isotropy but not of homogeneity. This is fully compatible with a fractal
+structure which has the property of local isotropy, but it is non-analytic and
+non-homogeneous.",9505106v1
+1998-04-03,Polarization of Astronomical Maser Radiation. IV. Circular Polarization Profiles,"Profile comparison of the Stokes parameters $V$ and $I$ is a powerful tool
+for maser data analysis, providing the first direct methods for unambiguous
+determination of (1) the maser saturation stage, (2) the amplification optical
+depth and intrinsic Doppler width of unsaturated masers, and (3) the
+comparative magnitudes of Zeeman splitting and Doppler linewidth. Circular
+polarization recently detected in OH 1720 MHz emission from the Galactic center
+appears to provide the first direct evidence for maser saturation.",9804040v1
+2000-05-31,Consequences of parton's saturation and string's percolation on the developments of cosmic ray showers,"At high gluon or string densities, gluons' saturation or the strong
+interaction among strings, either forming colour ropes or giving rise to
+string's percolation, induces a strong suppression in the particle
+multiplicities produced at high energy. This suppression implies important
+modifications on cosmic ray shower development. In particular, it is shown that
+it affects the depth of maximum, the elongation rate, and the behaviour of the
+number of muons at energies around 10^{17}-10^{18} eV. The existing cosmic ray
+data point out in the same direction.",0005588v1
+2004-11-05,The QCD Black Disk Limit in Cosmic Ray Air Showers,"We discuss particle production in the high energy limit of QCD. Due to a
+large gluon density, the interaction reaches the black disk limit and the
+projectile is resolved into its partonic structure at the saturation scale.
+This leads to suppression of forward particle production and hereby to a faster
+absorption of cosmic ray air showers. This property is most suitable for the
+distinction of evolution scenarios for the saturation scale, e.g. fixed and
+running coupling BFKL, the latter of which is favored by air shower
+measurements.",0411143v1
+2005-11-16,The role of differential rotation in the evolution of the r-mode instability,"We discuss the role of differential rotation in the evolution of the l=2
+r-mode instability of a newly born, hot, rapidly-rotating neutron star. It is
+shown that the amplitude of the r-mode saturates in a natural way at a value
+that depends on the amount of differential rotation at the time the instability
+becomes active. It is also shown that, independently of the saturation
+amplitude of the mode, the star spins down to a rotation rate that is
+comparable to the inferred initial rotation rates of the fastest pulsars
+associated with supernova remnants.",0511485v1
+1997-10-10,Intrinsic Decoherence in Mesoscopic Systems,"We present measurements of the phase coherence time $\tau_\phi$ in six
+quasi-1D Au wires and clearly show that $\tau_\phi$ is temperature independent
+at low temperatures. We suggest that zero-point fluctuations of the intrinsic
+electromagnetic environment are responsible for the observed saturation of
+$\tau_\phi$. We introduce a new functional form for the temperature dependence
+and present the results of a calculation for the saturation value of
+$\tau_\phi$. This explains the observed temperature dependence of our samples
+as well as many 1D and 2D systems reported to date.",9710095v1
+1997-12-05,Influence of Hydrodynamic Interactions on the Kinetics of Colloidal Particle's Adsorption,"The kinetics of irreversible adsorption of spherical particles onto a flat
+surface is theoretically studied. Previous models, in which hydrodynamic
+interactions were disregarded, predicted a power-law behavior $t^{-2/3}$ for
+the time dependence of the coverage of the surface near saturation.
+Experiments, however, are in agreement with a power-law behavior of the form
+$t^{-1/2}$. We outline that, when hydrodynamic interactions are considered, the
+assymptotic behavior is found to be compatible with the experimental results in
+a wide region near saturation.",9712076v1
+2001-01-11,Mutual Information of Population Codes and Distance Measures in Probability Space,"We studied the mutual information between a stimulus and a large system
+consisting of stochastic, statistically independent elements that respond to a
+stimulus. The Mutual Information (MI) of the system saturates exponentially
+with system size. A theory of the rate of saturation of the MI is developed. We
+show that this rate is controlled by a distance function between the response
+probabilities induced by different stimuli. This function, which we term the
+{\it Confusion Distance} between two probabilities, is related to the Renyi
+$\alpha$-Information.",0101161v3
+2002-04-19,Using NMR to Measure Fractal Dimensions,"A comment is made on the recent PFG NMR measurements by Stallmach, et al. on
+water-saturated sands [Phys. Rev. Lett. 88, 105505 (2002)]. It is pointed out
+that the usual law for the time-dependent diffusion coefficient D(t) used by
+these authors is not valid for a fractal surface. It is shown that (1-D(t)/D0)
+\~ t^[(3-Ds)/2] at short times for a surface of fractal dimension Ds, where D0
+is the bulk diffusion coefficient. Preliminary PFG NMR data on water saturated
+limestone and plastic beads are presented to illustrate this analysis.",0204431v1
+2002-05-09,"Saturation of Spontaneous Polarization Charge in Pyroelectric Crystals of LiNbO3, LiTaO3 and CsNO3 at Low Temperature Above 4.2 K","Experimental observations of the change in the polarization charge of
+pyroelectric crystals of LiNbO3, LiTaO3 and CsNO3, as the temperature of the
+crystal is changed from about 300K to a lower limit of 4.2K, are described. It
+was found that the rate of change of the polarization charge slowed down
+considerably and, perhaps, reached a zero rate of change. The onset of this
+saturation of the polarization charge occurred at low temperatures, above the
+temperature of liquid helium, which were different for each of the three types
+of crystal.",0205189v2
+2002-05-23,Bistable Gradient Networks II: Storage Capacity and Behaviour Near Saturation,"We examine numerically the storage capacity and the behaviour near saturation
+of an attractor neural network consisting of bistable elements with an
+adjustable coupling strength, the Bistable Gradient Network (BGN). For strong
+coupling, we find evidence of a first-order ""memory blackout"" phase transition
+as in the Hopfield network. For weak coupling, on the other hand, there is no
+evidence of such a transition and memorized patterns can be stable even at high
+levels of loading. The enhanced storage capacity comes, however, at the cost of
+imperfect retrieval of the patterns from corrupted versions.",0205465v1
+2002-07-31,Microwave saturation of the Rydberg states of electrons on helium,"We present measurements of the resonant microwave excitation of the Rydberg
+energy levels of surface state electrons on superfluid helium. The temperature
+dependent linewidth agrees well with theoretical predictions and is very small
+below 300 mK. Absorption saturation and power broadening were observed as the
+fraction of electrons in the first excited state was increased to 0.49, close
+to the thermal excitation limit of 0.5. The Rabi frequency was determined as a
+function of microwave power. The high values of the ratio of the Rabi frequency
+to linewidth confirm this system as an excellent candidate for creating qubits.",0208001v1
+2002-08-20,Calculations on Electronic States in QDs woth Saturated Shapes,"Electronic States of Si and Ge QDs of 5 to 3127 atoms with saturated shapes
+in a size range of 0.57 to 4.92 nm for Si and 0.60 to 5.13 nm for Ge are
+calculated by using an empirical tight binding model combined with the
+irreducible representations of the group theory. The results are compared with
+those of Si and Ge quantum dots with spherical shape. The effects of the shapes
+on electronic states in QDs are discussed.",0208395v1
+2002-09-12,Electron dephasing near zero temperature: an experimental review,"The behavior of the electron dephasing time near zero temperature,
+$\tau_\phi^0$, has recently attracted vigorous attention. This renewed interest
+is primarily concerned with whether $\tau_\phi^0$ should reach a finite or an
+infinite value as $T \to$ 0. While it is accepted that $\tau_\phi^0$ should
+diverge if there exists only electron-electron (electron-phonon) scattering,
+several recent measurements have found that $\tau_\phi^0$ depends only very
+weakly on temperature, if at all, when $T$ is sufficiently low. This article
+discusses the current experimental status of ""the saturation problem"", and
+concludes that the origin(s) for this widely observed saturation are still
+unresolved.",0209275v1
+2002-12-10,A giant overshoot effect in the Janssen granular column,"We present new experimental results on the mechanical behavior of static
+granular assemblies confined in a vertical column. Our measurements confirm,
+for the first time, the universal Janssen's scaling for the stress saturation
+curve. We show consequently, in the context of isotropic elasticity, a relation
+between the Poisson ratio and granular packing fraction. Moreover, using a
+systematic study of the overshoot effect created by a top mass equal to the
+saturation mass, we show behaviors reproduced qualitatively by isotropic
+elastic materials but in the case of a granular assembly of a spectacular
+amplitude. These experimental results are strong tests for any theory of
+granular matter.",0212228v1
+2003-08-22,Controlling a mesoscopic spin environment by quantum bit manipulation,"We present a unified description of cooling and manipulation of a mesoscopic
+bath of nuclear spins via coupling to a single quantum system of electronic
+spin (quantum bit). We show that a bath cooled by the quantum bit rapidly
+saturates. Although the resulting saturated states of the spin bath (``dark
+states'') generally have low degrees of polarization and purity, their symmetry
+properties make them a valuable resource for the coherent manipulation of
+quantum bits. Specifically, we demonstrate that the dark states of nuclear
+ensembles can be used to coherently control the system-bath interaction and to
+provide a robust, long-lived quantum memory for qubit states.",0308459v1
+2005-04-05,Cs adsorption on Si(001) surface: ab initio study,"First-principles calculations using density functional theory based on
+norm-conserving pseudopotentials have been performed to investigate the Cs
+adsorption on the Si(001) surface for 0.5 and 1 ML coverages. We found that the
+saturation coverage corresponds to 1 ML adsorption with two Cs atoms occupying
+the double layer model sites. While the 0.5 ML covered surface is of metallic
+nature, we found that 1 ML of Cs adsorption corresponds to saturation coverage
+and leads to a semiconducting surface. The results for the electronic behavior
+and surface work function suggest that adsorption of Cs takes place via
+polarized covalent bonding.",0504088v2
+2005-08-09,Classical magnetotransport of inhomogeneous conductors,"We present a model of magnetotransport of inhomogeneous conductors based on
+an array of coupled four-terminal elements. We show that this model generically
+yields non-saturating magnetoresistance at large fields. We also discuss how
+this approach simplifies finite-element analysis of bulk inhomogeneous
+semiconductors in complex geometries. We argue that this is an explanation of
+the observed non-saturating magnetoresistance in silver chalcogenides and
+potentially in other disordered conductors. Our method may be used to design
+the magnetoresistive response of a microfabricated array.",0508229v2
+2005-10-24,Universality in edge-source diffusion dynamics,"We show that in edge-source diffusion dynamics the integrated concentration
+N(t) has a universal dependence with a characteristic time-scale tau=(A/P)^2
+pi/(4D), where D is the diffusion constant while A and P are the
+cross-sectional area and perimeter of the domain, respectively. For the
+short-time dynamics we find a universal square-root asymptotic dependence
+N(t)=N0 sqrt(t/tau) while in the long-time dynamics N(t) saturates
+exponentially at N0. The exponential saturation is a general feature while the
+associated coefficients are weakly geometry dependent.",0510627v2
+2005-12-09,Stacking of oligo and polythiophenes cations in solution: surface tension and dielectric saturation,"The stacking of positively charged (or doped) terthiophene oligomers and
+quaterthiophene polymers in solution is investigated applying a recently
+developed unified electrostatic and cavitation model for first-principles
+calculations in a continuum solvent. The thermodynamic and structural patterns
+of the dimerization are explored in different solvents, and the distinctive
+roles of polarity and surface tension are characterized and analyzed.
+Interestingly, we discover a saturation in the stabilization effect of the
+dielectric screening that takes place at rather small values of $\epsilon_0$.
+Moreover, we address the interactions in trimers of terthiophene cations, with
+the aim of generalizing the results obtained for the dimers to the case of
+higher-order stacks and nanoaggregates.",0512203v1
+2005-12-14,Terahertz plasma wave generation in ultra-short-channel Field Effect Transistors: theory vs experiment,"Taking into account both the scattering and the velocity saturation of
+carriers, we examine the ""shallow-water"" instability of the two-dimensional
+electron gas in a field effect transistor. It is shown that both the scattering
+(which is analogous to friction in a shallow-water channel) and the carrier
+velocity saturation lead to damping of the plasma wave instability. Threshold
+diagram of instability is calculated. The actual device parameters required for
+observation of plasma wave generation are compared with those reported in
+recent sub-terahertz emission experiments.",0512322v1
+1994-11-24,Meson Correlators in QCD Vacuum - is Saturation the Right Approach ?,"Equal time, point to point correlation functions for spatially separated
+meson currents are calculated with respect to a variational construct for the
+ground state of QCD. With exact calculations, vector, axial vector and scalar
+channels show qualitative agreement with the phenomenological predictions,
+where as pseudoscalar channel does not. However, the pseudoscalar correlator,
+when approximated by saturating with intermediate one pion states agrees with
+results obtained from spectral density functions parametrised by pion decay
+constant and $<\bar \psi \psi>$ value obtained from chiral perturbation theory.",9411402v1
+1996-09-13,Saturation of Gluon Density at Small x,"Gluon distribution function at small x is computed using the extended
+McLerran-Venugopalan model. A lipatov like enhancement is seen as well as a
+non-trivial transverse momentum dependence which is estimated. It is shown that
+gluon density saturates at small x which would lead to unitarization of cross
+sections computed with this distribution function.",9609350v1
+1997-09-04,A modified BFKL equation with unitarity,"We propose a modified Balitskii-Fadin-Kuraev-Lipatov equation from the
+viewpoint of the resummation technique, which satisfies the unitarity bound.
+The idea is to relax the strong rapidity ordering and to restrict phase space
+for real gluon emissions in the evaluation of the BFKL kernel. It is found that
+the gluon distribution function rises as a power of the Bjorken variable $x$,
+and then saturates at $x\to 0$. We estimate that the saturation begins to occur
+for $x< 10^{-4}$.",9709236v2
+1998-02-19,Higgs mass saturation effect and the LHC discovery potential,"In view of recent perturbative and nonperturbative evidence that the peak of
+the Higgs resonance saturates as the coupling increases, we examine the
+potential of the future Large Hadron Collider to discover a heavy Higgs
+resonance by gluon fusion.",9802367v1
+1998-07-27,Saturation Effects in Deep Inelastic Scattering at low $Q^2$ and its Implications on Diffraction,"We present a model based on the concept of saturation for small $Q^2$ and
+small $x$. With only three parameters we achieve a good description of all Deep
+Inelastic Scattering data below $x=0.01$. This includes a consistent treatment
+of charm and a successful extrapolation into the photoproduction regime. The
+same model leads to a roughly constant ratio of diffractive and inclusive cross
+section.",9807513v1
+1999-04-20,Parton Saturation at Small x and in Large Nuclei,"Quark and gluon distributions in the light-cone wavefunction of a high energy
+hadron or nucleus are calculated in the saturation regime. One loop
+calculations are performed explicitly using the equivalence between the parton
+distribution in the light-cone wavefunction and the production distribution of
+that parton in a current-nucleon (nucleus) scattering. We argue that, except
+for some overall numerical factors, the Weizsacker- Williams wavefunction
+correctly gives the physics of the gluon distribution in a light-cone
+wavefunction.",9904404v1
+1999-07-29,From QCD to heavy ion collisions,"This talk will discuss how heavy ion experiments, when moving from SPS (10 +
+10 GeV) to RHIC (100+100 GeV) and to LHC (2750+2750 GeV), will enter a new
+domain of QCD in which the production of even large pT gluons is so abundant
+that it is simultaneously perturbative but such that the phase space density of
+gluons is saturated. The saturation scale is estimated, quantitative numbers
+for the initial production of gluons at the LHC are given and options for their
+subsequent evolution are outlined. For parametrically large nuclei and
+energies, classical field methods will be applicable.",9907544v1
+1999-10-27,Low Energy Constants from High Energy Theorems,"New constraints on resonance saturation in chiral perturbation theory are
+investigated. These constraints arise because each consistent saturation scheme
+must map to a representation of the full QCD chiral symmetry group. The
+low-energy constants of chiral perturbation theory are then related by a set of
+mixing angles. It is shown that vector meson dominance is a consequence of the
+fact that nature has chosen the lowest-dimensional nontrivial chiral
+representation. It is further shown that chiral symmetry places an upper bound
+on the mass of the lightest scalar in the hadron spectrum.",9910525v1
+2000-02-29,Non-saturation of the J/psi suppression at large transverse energy in the comovers approach,"We show that, contrary to recent claims, the $J/\psi$ suppression resulting
+from its interaction with comovers does not saturate at large transverse energy
+$E_T$. On the contrary, it shows a characteristic structure - change of
+curvature near the knee of the $E_T$ distribution - which is due to the $E_T$
+(or multiplicity) fluctuation, and agrees with recent experimental results.",0002300v1
+2000-05-30,Loops and legs beyond perturbation theory,"Within the non-perturbative 1/N expansion, we discuss numerical methods for
+calculating multi-loop Feynman graph needed to derive physical scattering
+amplitudes. We apply higher order 1/N methods to the scalar sector of the
+standard model, and show the existence of a mass saturation effect. The mass
+saturation has direct implications for future searches at the LHC and at
+possible muon colliders.",0005307v1
+2000-07-24,Colour Dipoles and Saturation,"We employ values of the colour dipole cross section extracted from
+electroproduction and photoproduction data to show that gluon saturation
+effects are not required by the current HERA data but will become important in
+the THERA energy region.",0007257v1
+2000-09-19,A manifestation of a gluon saturation in e-A DIS,"This is a short presentation of our talks given at eRHIC Workshop at the BNL.
+We give here a status report of our attempts to understand how gluon saturation
+will manifest itself in deep inelastic scattering with nuclei. This summary
+reflects our current understanding and shows directions of our research rather
+then a final answer to the question. Nevertheless, we are able to share with
+our reader our tentative answer to the question:``Why do we need to measure DIS
+with nuclei and why these data will be complementary to the information
+obtained from proton DIS"".",0009217v1
+2000-09-25,Particle Rapidity Density Saturation in Heavy Ion Collisions and the Dual String Model,"We show that the Dual String Model with fusion leads, in heavy ion
+collisions, to strict saturation of the particle (pseudo-)rapidity density,
+normalised to the number of participant nucleons, as that number increases.
+Asymptotically, as the centre-of-mass energy goes to infinity with the number
+of participants fixed, this density approaches the nucleon-nucleon density.
+  A comparison with recent WA98 data is presented.",0009288v1
+2000-10-06,Searching Saturation in eA Processes,"The high density effects should be manifest at small x and/or large nuclei.
+In this letter we consider the behavior of nuclear structure function $F_2^A$
+slope in the kinematic region which could be explored in the future eA
+colliders as a search of these effects. We verify that the high density implies
+that the maximum value of the slope occurs at large values of the photon
+virtuality, i.e. in a perturbative regime, and is dependent of the number of
+nucleons A and energy. Our conclusion is that the measurement of this
+observable will allow to explicit the saturation.",0010060v1
+2001-02-06,QCD sum rules for rho mesons in nuclear matter,"We investigate QCD sum rules for vector currents in the rho meson channel in
+the nuclear medium. For increased sensitivity, we subtract out the vacuum
+contributions. With a saturation scheme often considered in the literature, we
+find these subtracted sum rules to be unstable. It indicates the importance of
+other contributions neglected in the saturation scheme. These include more
+Landau singularities at low energy, additional operators in the medium, and
+possibly the in-medium width of the rho meson.",0102062v2
+2001-05-10,Vacuum Saturation Hypothesis and QCD Sum Rules,"The accuracy of the vacuum saturation hypothesis is discussed using the
+examples of vacuum expectation values of four-quark operators and the parameter
+$B$, which determines the short-distance contribution to the $K^0 - \bar K^0$
+mixing. Note added: The approach based on sum rules in position (x-)space as
+elaborated in the paper is relevant and useful tool for the current
+phenomenology. In particular, it provides the unique possibility of direct
+non-perturbative estimation of the VEV's of four-quark operators renormalized
+in any scheme, including the MSbar one.",0105093v1
+2001-05-31,Diffractive parton distributions and the saturation model,"We construct diffractive parton distributions in the model of DIS diffraction
+in which the diffractive state is formed by the $q\bar{q}$ and $q\bar{q}g$
+components. The interaction of such systems with the proton is described by the
+dipole cross section given by the saturation model. We find Regge factorization
+property with the measured at HERA depenedence on energy. The found parton
+distributions are evolved with the DGLAP evolution equations to make a
+comparison with the data.",0105333v1
+2001-06-11,Scaling phenomena from non-linear evolution in high energy DIS,"The numerical solutions of the non-linear evolution equation are shown to
+display the ``geometric'' scaling recently discovered in the experimental data.
+The phenomena hold both for proton and nucleus targets for all $x$ below
+$10^{-2}$ and $0.25 {\rm GeV^{2}}\le Q^2 \le 2.5\times10^3 {\rm GeV^{2}}$. The
+scaling is practically exact (few percent error) in the saturation region. In
+addition, an approximate scaling is found in the validity domain of the linear
+evolution where it holds with about 10% accuracy.
+  Basing on the scaling phenomena we determine the saturation scale $Q_s(x)$
+and study both its $x$-dependence and the atomic number dependence for the
+nuclei.",0106112v1
+2001-06-28,Heavy ion collision multiplicities and gluon distribution functions,"Atomic number ($A$) and energy ($\roots$) scaling exponents of multiplicity
+and transverse energy in heavy ion collisions are analytically derived in the
+perturbative QCD + saturation model. The exponents depend on the small-$x$
+behaviour of gluon distribution functions at an $x$-dependent scale. The
+relation between initial state and final state saturation is also discussed.",0106330v1
+2001-07-06,An example of resonance saturation at one loop,"We argue that the large-Nc expansion of QCD can be used to treat a Lagrangian
+of resonances in a perturbative way. As an illustration of this we compute the
+L_10 coupling of the Chiral Lagrangian by integrating out resonance fields at
+one loop. Given a Lagrangian and a renormalization scheme, this is how in
+principle one can answer in a concrete and unambiguous manner questions such as
+at what scale resonance saturation takes place.",0107062v2
+2001-11-29,Gluon Saturation at small x,"At very high energies, the relevant component of the hadron wavefunction can
+be described as a Color Glass Condensate, i.e., a state of high density gluonic
+matter whose distribution is random, but frozen over the relevant time scales.
+The weight function for this distribution obeys a renormalization group
+equation in the form of a functional Fokker-Planck equation. Its solution leads
+to an effective theory which predicts gluon saturation at sufficiently high
+energy, or small Bjorken's $x$.",0111400v1
+2001-11-30,The Diffractive Logarithmic Slope and the Saturation Phenomena,"The logarithmic slope of the diffractive structure function is a potential
+observable scanning the hard and soft contributions in diffraction, allowing to
+disentangle the QCD dynamics. We report our calculations concerning this
+quantity, in particular the estimates emerging from the saturation model
+applied to diffraction dissociation.",0111444v1
+2001-11-30,Saturation in DIS processes,"We examine HERA data with a view of determining whether unique signs of
+saturation can be identified. Concentrating on two channels the logarithmic
+slope of $F_{2}$, and the production of $J/\Psi$, which are sensitive to the
+behaviour of $xG(x,Q^{2})$ the gluon density distribution in the proton, we
+show that our model incorporating screening corrections and alternative models
+comprising a sum of a ""soft"" and ""hard"" component provide good fits to the
+data.",0111449v1
+2001-11-30,Dipole-proton $S$-matrix derived from diffractive meson electroproduction,"Through a determination of the $S$-matrix element for the scattering of a
+localized colour dipole on a proton, we show that saturation effects can
+already be sizable at HERA. The saturation scale is found to be around 1-1.5
+$GeV^2$ for the highest available energies and for central collisions, and is a
+decreasing function of the impact parameter.",0111454v1
+2002-04-18,Does parton saturation at high density explain hadron multiplicities at RHIC ?,"We discuss the recent claim that hadron multiplicities measured at RHIC
+energies are directly described in terms of gluon degrees of freedom fixed from
+the initial conditions of central heavy ion collisions. The argument is based
+on the parton saturation scenario expected to be valid at high parton densities
+and on the assumption of conserved gluon number. Alternatively we conjecture
+that ""bottom-up"" equilibration before hadronization modifies this picture, due
+to nonconservation of the number of gluons.",0204211v1
+2002-05-03,Photon production in high energy proton-nucleus collisions,"We calculate the photon production cross-section in $pA$ collisions under the
+assumption that the nucleus has reached the saturation regime, while the proton
+can be described by the standard parton distribution functions. We show that
+due to the strong classical field $O(1/g)$ of the nucleus, bremsstrahlung
+diagrams become dominant over the direct photon diagrams. In particular, we
+show that $\gamma-$jet transverse momentum spectrum and correlations are very
+sensitive to gluon saturation effects in the nucleus.",0205037v1
+2002-05-17,Thermal QCD sum rules for mesons,"A recently proposed scheme is used to saturate the spectral side of the QCD
+sum rules derived from the thermal, two-point correlation functions of the
+vector and the axial-vector currents. At low temperature, it constructs the
+spectral representation from all the one-loop Feynman diagrams for the
+two-point functions. The old saturation scheme treats incorrectly some of these
+contributions. We end up with the familiar QCD sum rules obtained from the
+difference of the two corresponding vacuum correlation functions. The
+possibility of obtaining new sum rules in other media is discussed.",0205186v1
+2002-05-29,Geometric Scaling in a Symmetric Saturation Model,"We illustrate geometric scaling for the photon-proton cross section with a
+very simple saturation model. We describe the proton structure function F2 at
+small x in a wide kinematical range with an elementary functional form and a
+small number of free parameters. We speculate that the symmetry between low and
+high Q2 recently discovered in the data could be related to a well-known
+symmetry of the two-gluon- exchange dipole-dipole cross section.",0205319v1
+2002-06-21,Gluon Distributions and Color Charge Correlations in a Saturated Light-cone Wavefunction,"We describe the light-cone wavefunction in the saturation regime in terms of
+the density of gluons per unit of transverse phase space, the occupation
+number, and in terms of the color charge correlator. The simple McLerran-
+Venugopalan model gives what are claimed to be general results for the phase
+space gluon density, but it does not well describe the general case for the
+charge correlator. We derive the general momentum dependence and rapidity
+dependence of the color charge correlator which exhibits strong color
+shielding. A simplel physical picture which leads to these general results is
+described.",0206216v1
+2002-06-21,Parton saturation effects to the Drell-Yan process in the color dipole picture,"We report on the results obtained in the study of the parton saturation
+effects, taken into account through the multiscattering Glauber-Mueller
+approach, applied to the Drell-Yan (DY) process described in the color dipole
+picture. As a main result, one shows that those effects play an important role
+in the estimates of the DY differential cross section atRHIC energies.",0206218v1
+2002-07-15,Saturation effects in DIS at low x,"We review basic ideas related to saturation of parton densities at small
+value of the Bjorken variable x. A special emphasis is put on interpreting the
+results from the ep deep inelastic scattering experiments at HERA.",0207188v3
+2002-08-15,Heavy Quark Photoproduction in k_T Factorization Approach,"We investigate the heavy quark photoproduction based on the k_T factorization
+approach, focusing on the results from the saturation model. The deviations in
+the results using the unintegrated gluon distribution considering the
+saturation model and the derivative of the collinear gluon distribution are
+analysed. Total cross sections and p_T distributions are analysed in detail,
+setting the deviations between the color dipole approximation and the complete
+semihard approach.",0208155v2
+2002-12-20,QCD Saturation and Deuteron-Nucleus Collisions,"We make quantitative predictions for the rapidity and centrality dependencies
+of hadron multiplicities in dA collisions at RHIC basing on the ideas of parton
+saturation in the Color Glass Condensate.",0212316v4
+2003-02-04,Saturation of optimality limits in hadron-hadron scatterings,"In this paper the optimal unitarity lower bound on logarithmic slope of the
+diffraction peak is investigated. It is shown that the unitarity lower bound is
+just the optimal logarithmic slopes predicted by the principle of least
+distance in space of states. A systematic tendency towards the saturation of
+the most forward-peaked limit is observed from all the available experimental
+data of all principal hadron-hadron (e.g., antiproton-proton, proton-proton,
+kaon-proton, pion-proton) scatterings practically at all laboratory momenta.",0302018v2
+2003-02-11,Deeply Virtual Compton Scattering and Saturation Approach,"We investigate the deeply virtual Compton scattering (DVCS) in the color
+dipole approach, implementing the dipole cross section through the saturation
+model, which interpolates successfully between soft and hard regimes. The
+imaginary and real part of the DVCS amplitude are obtained and the results are
+compared to the available data.",0302079v2
+2003-02-20,Nonlinear corrections to the DGLAP equations; looking for the saturation limits,"The effects of the first nonlinear corrections to the DGLAP equations are
+studied in light of the HERA data. Saturation limits are determined in the
+DGLAP+GLRMQ approach for the free proton and for the Pb nucleus.",0302185v1
+2003-03-14,Gamma^* - Gamma^* Scattering: Saturation and Unitarization in the BFKL approach,"In this paper $\gamma^* - \gamma^*$ scattering with large, but more or less
+equal virtualities of two photons is discussed using BFKL dynamics, emphasizing
+the large impact parameter behavior ($b_t$) of the dipole-dipole amplitude. It
+is shown that the non-perturbative contribution is essential to fulfill the
+unitarity constraints in the region of $b_t > 1/2 m_\pi$, where $m_{\pi}$ is
+pion mass. The saturation and the unitarization of the dipole-dipole amplitude
+is considered in the framework of the Glauber-Mueller approach. The main result
+is that we can satisfy the unitarity constraints introducing the
+non-perturbative corrections only in initial conditions (Born amplitude).",0303118v1
+2003-05-06,Nuclear Structure Functions at Small x in Multiple Scattering Approaches,"A simple model for nuclear structure functions in the region of small $x$ and
+small and moderate $Q^2$, is presented. It is a parameter-free extension, in
+the Glauber-Gribov approach to nuclear collisions, of a saturation model for
+the nucleon. A reasonable agreement with experimental data on ratios of nuclear
+structure functions is obtained. The unintegrated gluon distribution and the
+behavior of the saturation scale which result from this model are discussed.",0305057v1
+2003-06-04,Decorrelation of forward dijets in DIS off nuclei,"Based on the color dipole QCD approach we discuss the multiple scattering
+mechanism (MSM) of suppression of back-to-back azimuthal correlations of high
+$p_{T}$ forward dijets in DIS off nuclei. We quantify the effect in terms of
+acoplanarity/decorrelation momentum of jets. For hard dijets the decorrelation
+momentum is found to be of the order of the nuclear saturation momentum $Q_A$.
+Minijets with the transverse momentum below the saturation scale are proved to
+be completely decorrelated. The analysis of DIS indicates that in heavy ion
+collisions the contribution of MSM to the reactions dynamics can be of the
+order of magnitude of the decorrelation effect observed at RHIC.",0306038v1
+2003-08-28,Dilepton Transverse Momentum in the Color Dipole Approach,"We investigate the Drell-Yan transverse momentum distribution in the
+framework of the color dipole approach. Special attention is paid to parton
+saturation effects at high energies. Predictions at LHC energies ($\sqrt{s}=14$
+TeV) are given and extrapolated down to ISR energies ($\sqrt{s}=62$ GeV).
+Unitarity corrections are implemented through the multiple scattering
+Glauber-Mueller approach and are compared with predictions of the BGBK
+saturation model.",0308304v1
+2003-11-03,System-size dependence,"The final state in The final state in heavy-ion collisions has a higher
+degree of strangeness saturation than the one produced in collisions between
+elementary particles like p-p or p-$\bar{p}$. A systematic analysis of this
+phenomenon is made for C-C, Si-Si and Pb-Pb collisions at the CERN SPS collider
+and for $Au-Au$ collisions at RHIC and at AGS energies. Strangeness saturation
+is shown to increase smoothly with the number of participants at AGS, CERN and
+RHIC energies.",0311020v1
+2004-07-09,Saturation and Traveling waves,"High parton density effects with energy obey non-linear QCD evolution
+equations for which exact solutions are not known. The mathematical class to
+which the non-linear Balitsky-Kovchegov equation belongs is identified, proving
+the existence of asymptotic in energy traveling wave solutions which are
+``universal'' i.e. independent of the initial conditions and of the precise
+form of the non-linearities. This has an direct impact on geometrical scaling
+and the diffusive transition to saturation, which is shown to be ``normal'' for
+constant QCD coupling and ``abnormal'' for running coupling.",0407115v1
+2004-08-02,Deeply Virtual Compton Scattering in the Saturation Approach,"We summarize here our investigations on the deeply virtual Compton scattering
+(DVCS) in the color dipole approach, implementing the dipole cross section
+through the saturation model. The role played by its QCD evolution and the
+skewedness effects in the DVCS cross section are discussed. The
+phenomenological results are compared to the recent H1 and ZEUS experimental
+data.",0408019v1
+2004-08-03,"CGC, QCD Saturation and RHIC data (Kharzeev-Levin-McLerran-Nardi point of view)","This is the talk given at the Workshop:""Focus on Multiplicitioes"", Bari,
+Italy, 17-19 June,2004.. In this talk, we are going to discuss ion-ion and
+deuteron - nucleus RHIC data and show that they support, if not more, the idea
+of the new QCD phase: colour glass condensate with saturated parton density. .",0408039v2
+2004-08-10,Saturation and non-linear effects in diffractive processes,"Through a direct implementation of the saturation regime resulting from the
+unitarity limit in the impact parameter representation, we explore various
+possibilities for the energy dependence of hadronic scattering. We show that it
+is possible to obtain a good description of the scattering amplitude from a
+hard pomeron provided one includes non-linear effects.",0408129v2
+2004-09-22,QCD saturation in the dipole sector with correlations,"In this paper we study the description of saturation in Balitsky,
+Jalilian-Marian, Iancu, McLerran, Weigert, Leonidov and Kovner (B-JIMWLK)
+picture when restricted to observables made up only from dipole operators. We
+derive a functional form of the evolution equation for the dipole probability
+distribution and find a one-parameter family of exact solutions to the dipole
+evolution equations.",0409256v3
+2004-12-22,Impact of saturation on spin effects in proton-proton scattering,"For pomerons described by a sum of two simple-pole terms, a soft and a hard
+pomeron, the unitarity bounds from saturation in impact-parameter space are
+examined. We consider the effect of these bounds on observables linked with
+polarisation, such as the analyzing power in elastic proton-proton scattering,
+for LHC energies. We obtain the s and t dependence of the Coulomb-nuclear
+interference at small momentum transfer, and show that the effect of the hard
+pomeron may be observed at the LHC.",0412341v1
+2005-03-03,Neutrino texture saturating the CP asymmetry,"We study a neutrino mass texture which can explain the neutrino oscillation
+data and also saturate the upper bound of the CP asymmetry $\epsilon_1$ in the
+leptogenesis. We consider the thermal and non-thermal leptogenesis based on the
+right-handed neutrino decay in this model. A lower bound of the reheating
+temperature required for the explanation of the baryon number asymmetry is
+estimated as $O(10^8)$GeV for the thermal leptogenesis and $O(10^{6})$GeV for
+the non-thermal one.It can be lower than the upper bound of the reheating
+temperature imposed by the cosmological gravitino problem. An example of the
+construction of the discussed texture is also presented.",0503031v1
+2005-03-24,The energy dependence of the saturation scale in DIS at low x,"Consistency of the previously suggested color-dipole representation of
+deep-inelastic scattering (DIS_) and vector-meson production at low x with
+DGLAP evolution allows one to predict the exponent of the W^2 dependence of the
+saturation scale Lambda_sat^2(W^2) ~ (W^2)^C-2. One finds C_2^theory = 0.27 in
+agreement with the model-independent analysis of the experimental data from
+HERA on deep-inelastic electron scattering.",0503251v3
+2005-04-11,The Balitsky-Kovchegov equation in full momentum space,"We analyse the Balitsky-Kovchegov (BK) saturation equation in momentum space
+and solve it numerically. We confirm that, in the limit where the transverse
+momentum of the incident particle k is much bigger than the momentum transfer
+q, the equation admits travelling-wave solutions. We extract the q dependence
+of the saturation scale Q_s(Y) and verify that Q_s(Y=cste) scales as
+max(q,Q_T), where Q_T is the scale caracterizing the target.",0504080v2
+2005-04-15,Open and hidden charm production in pA collisions,"We discuss production of charmed mesons and J/Psi in p(d)A collisions at high
+energies. We argue that when the saturation scale Qs characterizing the parton
+density in a nucleus exceeds the quark mass m, the naive perturbation theory
+breaks down. Consequently, we calculate a process of heavy quark production in
+both open and hidden channels in the framework of the parton saturation model
+(Color Glass Condensate). We demonstrate that at RHIC such description is in
+agreement with experimental data on charm production.",0504133v1
+2005-07-08,"J/Psi photo- and electroproduction, the saturation scale and the gluon structure function","Our approach to low-x deep inelastic scattering based on the ell-perp
+factorization of perturbative QCD (the color-dipole picture) yields
+parameter-free absolute predictions for J/Psi production. The connection of
+J/Psi production to the low-x saturation scale and to the gluon structure
+function is clarified.",0507098v3
+2005-09-05,Testing saturation with large-mass diffraction in DIS,"In large-mass diffraction in deep inelastic scattering, we study the gluon
+jet close to the rapidity gap and show that its transverse momentum spectrum is
+peaked around a value which caracterizes the onset of S-matrix unitarity. We
+argue that such a measurement of diffractive jets could help understanding if
+at the present energies, unitarity comes as a consequence of saturation.",0509034v1
+2005-12-20,Asymptotic neutrino-nucleon cross section and saturation effects,"In this paper we present a simple analytic expression for the (spin-averaged)
+neutrino-nucleon cross section for ultra-high energies at twist-2, obtained as
+the asymptotic limit of our previous findings. This expression gives values for
+the cross section in remarkable numerical agreement with the previous numerical
+evaluation in the energy region relevant for forthcoming neutrino experiments.
+Moreover, we discuss the role and the relevance of saturation and recombination
+effects in our approach, in comparison with other recent suggestions.",0512259v1
+2005-12-27,Dipole amplitude correlation in saturation model beyond mean field approximation,"In this paper we calculate dipole amplitude and dipole amplitude correlations
+using first and second equation from Balitsky-Kovchegov hierarchy. Our analysis
+shows that even in presence of weak dipole correlation in initial condition
+mean field approximation breaks down through evolution. This difference
+asymptotically grows not only by absolute value but also by relative difference
+of dipole correlation from mean field value. This could affect physical values
+related to dipole correlation such as elliptic flow $v_2$ and 'back-forward'
+asymmetry in saturation model.",0512343v1
+2006-05-13,DGLAP improved saturation model with heavy flavours,"The DGLAP improved saturation model of Bartels, Golec and Kowalski is
+supplemented by the contribution from the heavy quarks: charm and beauty. It is
+shown to give good description of both the total proton structure function F2
+and, as a prediction, the heavy quarks contribution F2c and F2b. The reasonable
+agreement for the longitudinal and diffractive structure functions is also
+found.",0605154v1
+2006-06-07,Geometric scaling in diffractive deep inelastic scattering,"The geometric scaling property observed in the HERA data at small x, that the
+deep inelastic scattering (DIS) total cross-section is a function of only the
+variable Q^2*x^\lambda, has been argued to be a manifestation of the saturation
+regime of QCD and of the saturation scale Q^2_s(x) x^{-\lambda}. We show that
+this implies a similar scaling in the context of diffractive DIS and we
+observe, for several diffractive observables, that the experimental data from
+HERA confirm the expectations of this scaling.",0606079v2
+2006-07-25,Heavy flavour production in DGLAP improved saturation model,"The charm and beauty quark production in deep inelastic scattering at low
+values of the Bjorken variable x is considered in the DGLAP improved saturation
+model. After fitting parameters of the model to the structure function F_2, the
+heavy quark contributions Fc_2 and Fb_2 are predicted. A good description of
+the data is found. Predictions for the longitudinal structure function F_L and
+the diffractive structure function FD_2 are also presented.",0607276v3
+2006-08-04,A geometrical scaling solution to the BFKL Pomeron Calculus in the saturation domain,"In this paper the exact analytical solution is found for the BFKL Pomeron
+calculus in QCD, in which all Pomeron loops have been included. This solution
+manifests the geometrical scaling behaviour and matches with the solution to
+the linear evolution equation on the line $r^2= 1/Q^2_s(x)$, where $r$ is the
+dipole size and $Q_s$ is the saturation momentum.",0608043v2
+2006-10-23,Mini review on saturation and recent developments,"I discuss the saturation regime of QCD: the weak-coupling regime that
+describes large parton densities inside hadrons and the resulting high-energy
+behavior of scattering amplitudes. I briefly review past successes in the
+context of deep inelastic scattering at HERA and forward particle production at
+RHIC, and I present some recent progresses that significantly improved our
+understanding of high-energy scattering in QCD.",0610300v1
+2006-12-01,Traveling waves and the renormalization group improved Balitsky-Kovchegov equation,"I study the incorporation of renormalization group (RG) improved BFKL kernels
+in the Balitsky-Kovchegov (BK) equation which describes parton saturation. The
+RG improvement takes into account important parts of the next-to-leading and
+higher order logarithmic corrections to the kernel. The traveling wave front
+method for analyzing the BK equation is generalized to deal with RG-resummed
+kernels, restricting to the interesting case of fixed QCD coupling. The results
+show that the higher order corrections suppress the rapid increase of the
+saturation scale with increasing rapidity. I also perform a ""diffusive""
+differential equation approximation, which illustrates that some important
+qualitative properties of the kernel change when including RG corrections.",0612005v1
+2006-12-11,Search for new physics from $B\toπφ$,"We investigate the pure penguin process $B^-\to \pi^-\phi$ using QCD
+factorization approach to calculate hadronic matrix elements to the $\alpha_s$
+order in some well-known NP models. It is shown that the NP contributions in
+R-parity conserved SUSY models and 2HDMs are not enough to saturate the
+experimental upper bounds for $B\to \phi \pi$. We have shown that the flavor
+changing $Z^\prime$ models can make the branching ratios of $B\to \phi \pi$ to
+saturate the bound under all relevant experimental constraints.",0612116v1
+2007-01-26,QCD at small x and nucleus-nucleus collisions,"At large collision energy sqrt(s) and relatively low momentum transfer Q, one
+expects a new regime of Quantum Chromo-Dynamics (QCD) known as ""saturation"".
+This kinematical range is characterized by a very large occupation number for
+gluons inside hadrons and nuclei; this is the region where higher twist
+contributions are as large as the leading twist contributions incorporated in
+collinear factorization. In this talk, I discuss the onset of and dynamics in
+the saturation regime, some of its experimental signatures, and its
+implications for the early stages of Heavy Ion Collisions.",0701225v1
+2007-02-03,Nuclear Modification to Parton Distribution Functions and Parton Saturation,"We introduce a generalized definition of parton distribution functions (PDFs)
+for a more consistent all-order treatment of power corrections. We present a
+new set of modified DGLAP evolution equations for nuclear PDFs, and show that
+the resummed $\alpha_s A^{1/3}/Q^2$-type of leading nuclear size enhanced power
+corrections significantly slow down the growth of gluon density at small-$x$.
+We discuss the relation between the calculated power corrections and the
+saturation phenomena.",0702040v1
+1995-11-17,Particle Growth and BPS Saturated States,"Consistency of the Bekenstein bound on entropy requires the physical
+dimensions of particles to grow with momentum as the particle is boosted to
+transplanckian energies. In this paper the problem of particle growth in
+heterotic string theory is mapped into a problem involving the properties of
+BPS saturated black holes as the charge is increased. Explicit calculation
+based on the black hole solutions of Sen are shown to lead to a growth pattern
+consistent with the holographic speculation described in earlier work.",9511116v2
+1997-06-30,Complex BPS domain walls and phase transition in mass in supersymmetric QCD,"We study the domain walls connecting different chirally asymmetric vacua in
+supersymmetric QCD. We show that BPS - saturated solutions exist only in the
+limited range of mass. When m exceeds some critical value, the domain wall
+either ceases to be BPS - saturated or disappears altogether. In any case, the
+properties of the system are qualitatively changed.",9706217v2
+1997-12-08,BPS Saturation from Null Reduction,"We show that any $d$-dimensional strictly stationary, asymptotically
+Minkowskian solution $(d\ge 4)$ of a null reduction of $d+1$-dimensional pure
+gravity must saturate the BPS bound provided that the KK vector field can be
+identified appropriately. We also argue that it is consistent with the field
+equations.",9712078v1
+1998-11-10,Non-Perturbative States in Superstring Theories,"Massless BPS-saturated states in toroidally compactified heterotic string
+were discussed first. Then, I constructed a large class of BPS-saturated states
+of toroidally compactified type II string theories. They were parametrized by
+four independent parameters. Both orthogonal and non-orthogonal intersections
+of non-perturbative states in the corresponding ten dimensional theories were
+discussed. Phenomenologically, I considered the string effect in the form of
+threshold corrections on dilatonic charged black holes, and the superpotential
+of N=1 supergravity theory",9811093v1
+1999-09-14,BPS States with Extra Supersymmetry,"A state saturating a BPS bound derived from a supersymmetry algebra preserves
+some fraction of the supersymmetry. This fraction of supersymmetry depends on
+the charges carried by the system, and we show that in general there are
+configurations of charges for which a BPS state would preserve more than half
+the original supersymmetry. We investigate configurations that could preserve
+3/4 supersymmetry in string theory, M-theory and supersymmetric field theories
+and discuss whether states saturating these bounds actually occur in these
+theories.",9909098v3
+1999-12-10,Domain wall junctions in a generalized Wess-Zumino model,"We investigate domain wall junctions in a generalized Wess-Zumino model with
+a Z(N) symmetry. We present a method to identify the junctions which are
+potentially BPS saturated. We then use a numerical simulation to show that
+those junctions indeed saturate the BPS bound for N=4. In addition, we study
+the decay of unstable non-BPS junctions.",9912081v3
+2001-07-05,Deformed Boost Transformations That Saturate at the Planck Scale,"We derive finite boost transformations based on the Lorentz sector of the
+bicross-product-basis $\kappa$-Poincare' Hopf albegra. We emphasize the role of
+these boost transformations in a recently-proposed new relativistic theory. We
+find that when the (dimensionful) deformation parameter is identified with the
+Planck length, which together with the speed-of-light constant has the status
+of observer-independent scale in the new relativistic theory, the deformed
+boosts saturate at the value of momentum that corresponds to the inverse of the
+Planck length.",0107039v1
+2002-04-06,Supercurves,"The TST-dual of the general 1/4-supersymmetric D2-brane supertube is
+identified as a 1/4-supersymmetric IIA `supercurve': a string with arbitrary
+transverse displacement travelling at the speed of light. A simple proof is
+given of the classical upper bound on the angular momentum, which is also
+recovered as the semi-classical limit of a quantum bound. The classical bound
+is saturated by a `superhelix', while the quantum bound is saturated by a
+bosonic oscillator state in a unique SO(8) representation.",0204062v1
+2005-05-02,"Scattering amplitudes for particles and strings in six-dimensional (2,0) theory","We study the scattering of low-energy tensor multiplet particles against a
+BPS saturated cosmic string. We show that the corresponding S-matrix is largely
+determined by symmetry considerations. We then apply a specific supersymmetric
+model of (2,0) theory and calculate the scattering amplitudes to lowest
+non-trivial order in perturbation theory. Our results are valid as long as the
+energy of the incoming particle is much lower than the square root of the
+string tension. The calculation involves the quantization of a (2,0) tensor
+multiplet and the derivation of an effective action describing the low-energy
+particles in the presence of a nearly BPS saturated string.",0505015v2
+1993-08-15,A saturated model of an unsuperstable theory of cardinality greater than its theory has the small index property,"A model M of cardinality lambda is said to have the small index property if
+for every G subseteq Aut(M) such that [Aut(M):G] <= lambda there is an A
+subseteq M with |A|< lambda such that Aut_A(M) subseteq G. We show that if M^*
+is a saturated model of an unsuperstable theory of cardinality > Th(M), then
+M^* has the small index property.",9308216v1
+2000-07-11,Passive scalar intermittency in low temperature helium flows,"We report new measurements of turbulent mixing of temperature fluctuations in
+a low temperature helium gas experiment, spanning a range of microscale
+Reynolds number, $R_{\lambda}$, from 100 to 650. The exponents $\xi_{n}$ of the
+temperature structure functions $<|\theta(x+r)-\theta(x)|^n > \sim r^{\xi_{n}}$
+are shown to saturate to $\xi_{\infty} \simeq 1.45 \pm 0.1$ for the highest
+orders, $n \sim 10$. This saturation is a signature of statistics dominated by
+front-like structures, the cliffs. Statistics of the cliff characteristics are
+performed, particularly their width are shown to scale as the Kolmogorov length
+scale.",0007011v1
+2003-03-21,Bifurcations and Averages in the Homoclinic Chaos of a Laser with a Saturable Absorber,"The dynamical bifurcations of a laser with a saturable absorber were
+calculated, with the 3-2 level model, as function of the gain parameter. The
+average power of the laser is shown to have specific behavior at bifurcations.
+The succession of periodic-chaotic windows, known to occur in the homoclinic
+chaos, was studied numerically. A critical exponent of 1/2 is found on the
+tangent bifurcations from chaotic into periodic pulsations.",0303047v1
+2003-05-02,Phase separation in coupled chaotic maps on fractal networks,"The phase ordering dynamics of coupled chaotic maps on fractal networks are
+investigated. The statistical properties of the systems are characterized by
+means of the persistence probability of equivalent spin variables that define
+the phases. The persistence saturates and phase domains freeze for all values
+of the coupling parameter as a consequence of the fractal structure of the
+networks, in contrast to the phase transition behavior previously observed in
+regular Euclidean lattices. Several discontinuities and other features found in
+the saturation persistence curve as a function of the coupling are explained in
+terms of changes of stability of local phase configurations on the fractals.",0305004v1
+2004-09-27,Exact Solutions of the Saturable Discrete Nonlinear Schrodinger Equation,"Exact solutions to a nonlinear Schr{\""o}dinger lattice with a saturable
+nonlinearity are reported. For finite lattices we find two different
+standing-wave-like solutions, and for an infinite lattice we find a localized
+soliton-like solution. The existence requirements and stability of these
+solutions are discussed, and we find that our solutions are linearly stable in
+most cases. We also show that the effective Peierls-Nabarro barrier potential
+is nonzero thereby indicating that this discrete model is quite likely
+nonintegrable.",0409057v1
+2005-06-17,Instabilities of multi-hump vector solitons in coupled nonlinear Schroedinger equations,"Spectral stability of multi-hump vector solitons in the Hamiltonian system of
+coupled nonlinear Schr\""{o}dinger (NLS) equations is investigated both
+analytically and numerically. Using the closure theorem for the negative index
+of the linearized Hamiltonian, we classify all possible bifurcations of
+unstable eigenvalues in the systems of coupled NLS equations with cubic and
+saturable nonlinearities. We also determine the eigenvalue spectrum numerically
+by the shooting method. In case of cubic nonlinearities, all multi-hump vector
+solitons in the non-integrable model are found to be linearly unstable. In case
+of saturable nonlinearities, stable multi-hump vector solitons are found in
+certain parameter regions, and some errors in the literature are corrected.",0506034v1
+2006-03-30,Radiationless Travelling Waves In Saturable Nonlinear Schrödinger Lattices,"The longstanding problem of moving discrete solitary waves in nonlinear
+Schr{\""o}dinger lattices is revisited. The context is photorefractive crystal
+lattices with saturable nonlinearity whose grand-canonical energy barrier
+vanishes for isolated coupling strength values. {\em Genuinely localised
+travelling waves} are computed as a function of the system parameters {\it for
+the first time}. The relevant solutions exist only for finite velocities.",0603071v2
+2006-08-10,Dark Solitons in Discrete Lattices: Saturable versus Cubic Nonlinearities,"In the present work, we study dark solitons in dynamical lattices with the
+saturable nonlinearity and compare them with those in lattices with the cubic
+nonlinearity. This comparison has become especially relevant in light of recent
+experimental developments in the former context. The stability properties of
+the fundamental waves, for both on-site and inter-site modes, are examined
+analytically and corroborated by numerical results. Furthermore, their
+dynamical evolution when they are found to be unstable is obtained through
+appropriately crafted numerical experiments.",0608023v1
+2002-01-28,Systematics of mid-rapidity K-/pi ratio in heavy-ion collisions,"It is observed that K-/pi in A+A and possibly p+p and pbar+p collisions
+follows an interesting systematic in omega, the pion transverse energy per unit
+of rapidity and transverse overlap area. The systematics show a linear increase
+of K-/pi with omega in the AGS and SPS energy regime and a saturation at RHIC
+energy. The systematics indicate that omega might be the relevant variable
+underlying K-/pi. At high energy, the omega variable is related to the gluon
+saturation scale in high density QCD, and perhaps to the initial energy density
+in the Bjorken picture.",0201018v2
+1997-06-02,Nuclear Saturation with in-Medium Meson Exchange Interactions,"We show that the assumption of dropping meson masses together with
+conventional many-body effects, implemented in the relativistic Dirac-Brueckner
+formalism, explains nuclear saturation. We use a microscopic model for
+correlated $2\pi$ exchange and include the standard many-body effects on the
+in-medium pion propagation, which initially increase the attractive
+nucleon-nucleon ($NN$) potential with density. For the vector meson exchanges
+in both the $\pi\pi$ and $NN$ sector, we assume Brown-Rho scaling which---in
+concert with `chiral' $\pi\pi$ contact interactions---reduces the attraction at
+higher densities.",9706006v1
+1998-07-14,Chiral dynamics of the nuclear equation of state,"We present a new chiral power expansion scheme for the nuclear equation of
+state. The scheme is effective in the sense that it is constructed to work
+around nuclear saturation density. The leading and subleading terms are
+evaluated and are shown to provide an excellent equation of state. As a further
+application we considered the chiral quark condensate in nuclear matter.
+Already at nuclear saturation density we predict a substantially smaller
+reduction of the condensate as compared to conventional approaches.",9807040v1
+2003-08-19,"Chiral solitons in nuclei: Saturation, EMC effect and Drell-Yan experiments","The Chiral Quark-Soliton model of the nucleon contains a mechanism for an
+attractive interaction between nucleons. This, along with the exchange of
+vector mesons between nucleons, is used to compute the saturation properties of
+infinite nuclear matter. This provides a new way to asses the effects of the
+nuclear medium on a nucleon that includes valence and sea quarks. We show that
+the model simultaneously describes the nuclear EMC effect and the related
+Drell-Yan experiments.",0308048v2
+2003-12-01,Equation of state for nuclear matter based on density dependent effective interaction,"An interesting method of obtaining equation of state for nuclear matter, from
+a density dependent M3Y interaction, by minimizing the energy per nucleon is
+described. The density dependence parameters of the interaction are obtained by
+reproducing the saturation energy per nucleon and the saturation density of
+spin and isospin symmetric cold infinite nuclear matter. The nuclear matter
+equation of state thus obtained is then used to calculate the pressure, the
+energy density, the nuclear incompressibility and the velocity of sound in
+nuclear medium. The results obtained are in good agreement with experimental
+data and provide a unified description of radioactivity, scattering and nuclear
+matter.",0312002v2
+2006-07-18,The High-Density Symmetry Energy and Direct Urca,"The symmetry energy of nucleonic matter is usually assumed to be quadratic in
+the isospin density. While this may be justified at sub-saturation densities,
+there is no need to enforce this restriction at super-saturation densities. The
+presence of a quartic term can strongly modify the critical density for the
+direct Urca process which leads to faster cooling of neutron stars. Neutron
+star cooling predictions which lie below the observational data can, for some
+equations of state, be repaired with a quartic term which effectively turns off
+the direct Urca process.",0607040v1
+1994-04-20,Whitham deformations partially saturating the modulational instability in the nonlinear Schrodinger equation,"In the framework of Gurevich and Pitaevskii approach [1] we construct
+modulated by Whitham [2] solution of nonlinear Shrodinger (NS) equation
+partially saturating the modulational instability. This solution describes new
+scenario of monochromatic wave evolution in NS equation which leads to
+generation of new phase and oscillation region.",9404003v1
+2003-07-18,Saturated-absorption spectroscopy: Eliminating crossover resonances using co-propagating beams,"We demonstrate a new technique for saturated-absorption spectroscopy using
+co-propagating beams that does not have the problem of crossover resonances.
+The pump beam is locked to a transition and its absorption signal is monitored
+while the probe beam is scanned. As the probe comes into resonance with another
+transition, the pump absorption is reduced and the signal shows a Doppler-free
+dip. We use this technique to measure hyperfine intervals in the $D_2$ line of
+$^{85}$Rb with a precision of 70 kHz, and to resolve hyperfine levels in the
+$D_2$ line of $^{39}$K that are less than 10 MHz apart.",0307095v1
+2003-09-23,Saturation induced coherence loss in coherent backscattering of light,"We use coherent backscattering (CBS) of light by cold Strontium atoms to
+study the mutual coherence of light waves in the multiple scattering regime. As
+the probe light intensity is increased, the atomic optical transition starts to
+be saturated. Nonlinearities and inelastic scattering then occur. In our
+experiment, we observe a strongly reduced enhancement factor of the coherent
+backscattering cone when the intensity of the probe laser is increased,
+indicating a partial loss of coherence in multiple scattering.",0309095v1
+2006-07-04,Beam interactions in one-dimensional saturable waveguide arrays,"The interaction between two parallel beams in one-dimensional discrete
+saturable systems has been investigated using lithium niobate nonlinear
+waveguide arrays. When the beams are separated by one channel and in-phase it
+is possible to observe soliton fusion at low power levels. This new result is
+confirmed numerically. By increasing the power, soliton-like propagation of
+weakly-coupled beams occurs. When the beams are out-of-phase the most
+interesting result is the existence of oscillations which resemble the recently
+discovered Tamm oscillations.",0607028v1
+1996-04-29,A Class of Quantum Error-Correcting Codes Saturating the Quantum Hamming Bound,"I develop methods for analyzing quantum error-correcting codes, and use these
+methods to construct an infinite class of codes saturating the quantum Hamming
+bound. These codes encode $k=n-j-2$ qubits in $n=2^j$ qubits and correct $t=1$
+error.",9604038v2
+1998-11-13,Stationary States in Saturated Two-Photon Processes and Generation of Phase-Averaged Mixtures of Even and Odd Quantum States,"We consider a relaxation of a single mode of the quantized field in a
+presence of one- and two-photon absorption and emission processes. Exact
+stationary solutions of the master equation for the diagonal elements of the
+density matrix in the Fock basis are found in the case of completely saturated
+two-photon emission. If two-photon processes dominate over single-photon ones,
+the stationary state is a mixture of phase averaged even and odd coherent
+states.",9811031v1
+2003-07-30,Sub and Super-Luminal Propagation of Intense Pulses in Media with Saturated and Reverse Absorption,"We develop models for the propagation of intense pulses in solid state media
+which can have either saturated absorption or exhibit reverse absorption . We
+show that the experiments of Bigelow {\it et al.}[Phys. Rev. Lett. {\bf 90},
+113903 (2003); Science {\bf 301}, 200 (2003).] on subluminal propagation in
+Ruby and superluminal propagation in Alexandrite are well explained by
+modelling them as three level and four level systems coupled to Maxwell
+equations. We present results well beyond the traditional pump-probe approach.",0307224v1
+2004-03-08,Coherent backscattering of light by atoms in the saturated regime,"We present the first calculation of coherent backscattering with inelastic
+scattering by saturated atoms. We consider the scattering of a
+quasi-monochromatic laser pulse by two distant atoms in free space. By
+restricting ourselves to scattering of two photons, we employ a perturbative
+approach, valid up to second order in the incident laser intensity. The
+backscattering enhancement factor is found to be smaller than two (after
+excluding single scattering), indicating a loss of coherence between the doubly
+scattered light emitted by both atoms. Since the undetected photon carries
+information about the path of the detected photon, the coherence loss can be
+explained by a which-path argument, in analogy with a double-slit experiment.",0403057v1
+2004-11-22,Phase delay time and superluminal propagation in barrier tunneling,"In this work we study the behaviour of Wigner phase delay time for tunneling
+in the reflection mode. Our system consists of a circular loop connected to a
+single wire of semi-infinite length in the presence of Aharonov-Bohm flux. We
+calculate the analytical expression for the saturated delay time. This
+saturated delay time is independent of Aharonov- Bohm flux and the width of the
+opaque barrier thereby generalizing the Hartman effect. This effect implies
+superluminal group velocities as a consequence. We also briefly discuss the
+concept called ""space collapse or space destroyer"".",0411161v1
+2005-10-20,Lyapunov Generation of Entanglement and the Correspondence Principle,"We show how a classically vanishing interaction generates entanglement
+between two initially nonentangled particles, without affecting their classical
+dynamics. For chaotic dynamics, the rate of entanglement is shown to saturate
+at the Lyapunov exponent of the classical dynamics as the interaction strength
+increases. In the saturation regime, the one-particle Wigner function follows
+classical dynamics better and better as one goes deeper and deeper in the
+semiclassical limit. This demonstrates that quantum-classical correspondence at
+the microscopic level requires neither high temperatures, nor coupling to a
+large number of external degrees of freedom.",0510157v1
+2007-05-11,Observation of higher-order solitons in defocusing waveguide arrays,"We observe experimentally higher-order solitons in waveguide arrays with
+defocusing saturable nonlinearity. Such solitons can comprise several in-phase
+bright spots and are stable above a critical power threshold. We elucidate the
+impact of the nonlinearity saturation on the domains of existence and stability
+of the observed complex soliton states.",0705.1704v1
+2007-05-11,Kerr quasinormal modes and Hod's time-temperature bound,"We give an explicit expression for the frequencies of slowly damped
+quasinormal modes of near-extreme Kerr black holes. It follows from this
+expression that the near-extreme Kerr holes obey the Hod's bound: in the limit
+of maximal rotation, $\lim \sup \omega_{IS}/T\leq \pi / \hbar$, where $\omega
+_{IS}$ is the decay rate of the slowest decaying quasinormal mode, $T$ is the
+black hole temperature. On the other hand, the bound is not saturated in the
+sense that $\lim \inf \omega_{IS}/T< \pi /\hbar$ is a strict inequality. {\it
+It remains unclear} whether the bound is saturated in the sense that $\lim \sup
+\omega_{IS}/T= \pi /\hbar$.",0705.1725v1
+2007-05-15,Elliptic flow from pQCD + saturation + hydro model,"We have previously predicted multiplicities and transverse momentum spectra
+of hadrons for the most central LHC Pb+Pb collisions at $\sqrt{s_{NN}}=5.5$ TeV
+using initial state for hydrodynamic evolution from pQCD + final state
+saturation model. By considering binary collision and wounded nucleon profiles
+we extend these studies to non-central collisions, and predict the $p_{T}$
+dependence of minimum bias $v_{2}$ for pions at the LHC. For protons we also
+show how the $p_{T}$ dependence of $v_2$ changes from RHIC to the LHC.",0705.2114v1
+2007-05-23,Soliton emission in amplifying optical lattice surfaces,"We address surface solitons supported by the interface of optical lattices
+imprinted in saturable media with surface-localized gain. The nonlinearity
+saturation puts restrictions on the maximal energy flow carried by surface
+solitons. As a consequence, the presence of thin amplifying layer near the
+surface results in the controllable emission of solitons towards the lattice at
+angles depending on the amplification rate and on lattice depth.",0705.3461v1
+2007-06-11,Non-forward Balitsky-Kovchegov equation and Vector Mesons,"Considering the Balitsky-Kovchegov QCD evolution equation in full momentum
+space, we derive the travelling wave solutions expressing the nonlinear
+saturation constraints on the dipole scattering amplitude at non-zero momentum
+transfer. A phenomenological application to elastic vector meson production
+shows the compatibility of data with the QCD prediction: an enhanced saturation
+scale at intermediate momentum transfer.",0706.1446v1
+2007-06-12,x-Evolution of Phenomenological Dipole Cross Sections,"Deep inelastic scattering at small x can be described very effectively using
+saturation inspired dipole models. We investigate whether such models are
+compatible with the numerical solutions of the Balitsky-Kovchegov (BK) equation
+which is expected to describe the nonlinear evolution in x of the dipole cross
+section. We find that the BK equation yields results that are qualitatively
+different from those of phenomenological studies. Geometric scaling is
+recovered only towards asymptotic rapidities. In this limit the value of the
+anomalous dimension gamma(r,x) at the saturation scale approaches approximately
+0.44, in contrast to the value 0.63 commonly used in the models.",0706.1666v1
+2007-07-10,Effect of Two Level System Saturation on Charge Noise in Josephson Junction Qubits,"We show that charge noise $S_Q$ in Josephson qubits can be produced by
+fluctuating two level systems (TLS) with electric dipole moments in the
+substrate using a flat density of states. At high frequencies the frequency and
+temperature dependence of the charge noise depends on the ratio $J/J_c$ of the
+electromagnetic flux $J$ to the critical flux $J_c$. It is not widely
+appreciated that TLS in small qubits can easily be strongly saturated with
+$J/J_c\gg 1$. Our results are consistent with experimental conclusions that
+$S_Q\sim 1/f$ at low frequencies and $S_Q\sim f$ at high frequencies.",0707.1514v1
+2007-07-15,Saturation model in the non-Glauber approach,"In this paper a new saturation model is presented. This model is based on the
+theoretical solution for the generating functional, and it is quite different
+and not more complicated than the Glauber-like approach used before. The model
+describes the structure function F_{2} of the proton, as well as the
+diffractive structure function F_{2}^{D}. We show the difference between our
+model, and the eikonal approach by calculating the multiplicity distribution,
+using the AGK cutting rules strategy.",0707.2202v4
+2007-07-19,Strong saturation absorption imaging of dense clouds of ultracold atoms,"We report on a far above saturation absorption imaging technique to
+investigate the characteristics of dense packets of ultracold atoms. The
+transparency of the cloud is controlled by the incident light intensity as a
+result of the non-linear response of the atoms to the probe beam. We detail our
+experimental procedure to calibrate the imaging system for reliable
+quantitative measurements, and demonstrate the use of this technique to extract
+the profile and its spatial extent of an optically thick atomic cloud.",0707.2930v1
+2007-08-06,Step-up simultaneous tests for identifying active effects in orthogonal saturated designs,"A sequence of null hypotheses regarding the number of negligible effects
+(zero effects) in orthogonal saturated designs is formulated. Two step-up
+simultaneous testing procedures are proposed to identify active effects
+(nonzero effects) under the commonly used assumption of effect sparsity. It is
+shown that each procedure controls the experimentwise error rate at a given
+$\alpha$ level in the strong sense.",0708.0715v1
+2007-08-09,Saturation of elliptic flow and shear viscosity,"Effect of shear viscosity on elliptic flow is studied in causal dissipative
+hydrodynamics in 2+1 dimensions. Elliptic flow is reduced in viscous dynamics.
+Causal evolution of minimally viscous fluid ($\eta/s$=0.08), can explain the
+PHENIX data on elliptic flow in 16-23% Au+Au collisions up to $p_T\approx$3.6
+GeV. In contrast, ideal hydrodynamics, can explain the same data only up to
+$p_T\approx$1.5 GeV. $p_T$ spectra of identified particles are also better
+explained in minimally viscous fluid than in ideal dynamics. However,
+saturation of elliptic flow at large $p_T$ is not reproduced.",0708.1252v2
+2007-10-10,Optical saturation driven by exciton confinement in molecular-chains: a TDDFT study,"We have identified excitonic confinement in one-dimensional molecular chains
+(i.e. polyacetylene and H$_2$) as the main driving force for the saturation of
+the chain polarizability as a function of the number of molecular units. This
+conclusion is based on first principles time--dependent density functional
+theory calculations performed with a new derived exchange--correlation kernel.
+The failure of simple local and semi--local functionals is shown to be related
+to the lack of memory effects, spatial ultranonlocality, and self--interaction
+corrections. These effects get smaller as the gap of the system reduces, in
+which case such simple approximations do perform better.",0710.2057v1
+2007-10-25,Robust control of uncertain multi-inventory systems via Linear Matrix Inequality,"We consider a continuous time linear multi inventory system with unknown
+demands bounded within ellipsoids and controls bounded within ellipsoids or
+polytopes. We address the problem of ""-stabilizing the inventory since this
+implies some reduction of the inventory costs. The main results are certain
+conditions under which ""-stabilizability is possible through a saturated linear
+state feedback control. All the results are based on a Linear Matrix
+Inequalities (LMIs) approach and on some recent techniques for the modeling and
+analysis of polytopic systems with saturations.",0710.4765v1
+2007-11-16,Electromagnetically induced transparency at high optical power,"We observe electromagnetically induced transparency (EIT) in Rb vapor at
+various optical intensities, starting from below saturation to several times
+the saturation intensity. The observed Lorentzian width of the EIT signal is
+very small. Solving the time dependant density matrix equation of motion with a
+phenomenological decay constant, we find an expression suitable in explaining
+the EIT signal. In this experimental observation and theoretical analysis
+intensity of EIT signal and its Lorentzian width increases with Rabi frequency
+of optical field.",0711.2662v2
+2007-12-11,Saturation of Transverse Energy per Charged Hadron and Freeze-Out Criteria in Heavy-Ion Collisions,"For beam energies from SPS to RHIC, the transverse energy per charged
+particle, $E_T/N_{\textrm{ch}}$, saturates at a value of approximately 0.8 GeV.
+A direct connection between this value and the freeze-out criterium $E/N
+\approx 1$ GeV for the primordial energy and particle number in the hadronic
+resonance gas model is established.",0712.1671v1
+2007-12-19,An essentially saturated surface not of Kaehler-type,"It is shown that if $X$ is an Inoue surface of type $S_M$ then the
+irreducible components of the Douady space of $X^n$ are compact, for all $n>0$.
+This gives an example of an essentially saturated compact complex manifold (in
+the sense of model theory) that is not of Kaehler-type. Among the known compact
+complex surfaces without curves, it is shown that these are the only examples.",0712.3234v1
+2008-01-31,Towards the saturation of the Froissart bound,"It is the aim of this paper to summarize results about the construction of
+amplitudes, which rigorously satisfy Mandelstam analyticity, crossing symmetry,
+and (at least partly) the constraints imposed by elastic and inelastic
+unitarity. The results are discussed under particular emphasis of a strong
+increase of the absorptive part of the forward amplitude and the saturation of
+the Froissart bound.",0801.4871v3
+2008-02-04,Geometric Scaling in Mueller-Navelet Jets,"We argue that the production of Mueller-Navelet jets at the LHC represents a
+convenient environment to study gluon saturation and high energy scattering in
+the presence of unitarity corrections. We show that, in a suitable range of
+transverse momenta for the produced jets, the cross section for the partonic
+subprocess should exhibit geometric scaling. We point out that, in the presence
+of a running coupling, the cross section for producing hard jets cannot be
+fully computed in perturbation theory, not even after taking into account the
+saturation effects: the non-perturbative physics affects the overall
+normalization of the cross section, but not also its geometric scaling
+behavior.",0802.0343v1
+2008-02-05,Slow light in saturable absorbers,"In connection with the experiments recently achieved on doped crystals,
+biological samples, doped optical fibers and semiconductor heterostructures, we
+revisit the theory of the propagation of a pulse-modulated light in a saturable
+absorber. Explicit analytical expressions of the transmitted pulse are
+obtained, enabling us to determine the parameters optimizing the time-delay of
+the transmitted pulse with respect to the incident pulse. We finally compare
+the maximum fractional delay or figure of merit so attainable to those which
+have been actually demonstrated in the experiments.",0802.0636v2
+2008-02-26,Saturation of nuclear matter in effective field theory,"The two- and three-nucleon interaction derived in chiral effective field
+theory at next-to-next-to-leading order is used to obtain the binding energy of
+nuclear matter. Saturation is found at a binding energy per particle E/A =
+-16.2 \pm 0.3 MeV and a Fermi momentum k_F = 1.30 \pm 0.03 fm^{-1}, where the
+uncertainty is due to the cut-off dependence of the two-nucleon interaction.
+The sensitivity of these values to the three-nucleon force is also studied.",0802.3782v2
+2008-04-11,Exact Bright and Dark Spatial Soliton Solutions in Saturable Nonlinear Media,"We present exact analytical bright and dark (black and grey) solitary wave
+solutions of a nonlinear Schrodinger-type equation describing the propagation
+of spatial beams in media exhibiting a saturable nonlinearity (such as
+centrosymmetric photorefractive materials). A qualitative study of the
+stationary equation is carried out together with a discussion of the stability
+of the solutions.",0804.1852v1
+2008-04-22,Dynamics of saturated Bragg diffraction in a stored light grating in cold atoms,"We report on a detailed investigation of the dynamics and the saturation of a
+light grating stored in a sample of cold cesium atoms. We employ Bragg
+diffraction to retrieve the stored optical information impressed into the
+atomic coherence by the incident light fields. The diffracted efficiency is
+studied as a function of the intensities of both writing and reading laser
+beams. A theoretical model is developed to predict the temporal pulse shape of
+the retrieved signal and compares reasonably well with the observed results.",0804.3523v1
+2008-04-24,High-field Current-carrying Capacity of Semiconducting Carbon Nanotubes,"It is shown that current saturation in semiconducting carbon nanotubes is
+indistinguishable from metallic nanotubes if the carrier density is above a
+critical value determined by the bandgap and the LO phonon energy. This feature
+stems from the higher number of current-carrying states in the semiconducting
+tubes due to the van-Hove singularity at the band-edge. Above this critical
+carrier density, the ensemble saturation velocity at high-fields is found to be
+independent of the bandgap, but strongly dependent on the carrier density,
+explaining recent observations.",0804.3997v2
+2008-06-03,Prompt neutrino fluxes from atmospheric charm,"We calculate the prompt neutrino flux from atmospheric charm production by
+cosmic rays, using the dipole picture in a perturbative QCD framework, which
+incorporates the parton saturation effects present at high energies. We compare
+our results with the next-to-leading order perturbative QCD result and find
+that saturation effects are large for neutrino energies above 10^6 GeV, leading
+to a substantial suppression of the prompt neutrino flux. We comment on the
+range of prompt neutrino fluxes due to theoretical uncertainties.",0806.0418v2
+2008-08-20,Saturation physics and angular correlations at RHIC and LHC,"We investigate the angular correlation between pions and photons produced in
+deuteron-gold collisions at RHIC and proton-lead collisions at LHC using the
+Color Glass Condensate formalism and make predictions for the dependence of the
+production cross section on the angle between the pion and photon at different
+rapidities and transverse momenta. Measuring this dependence would shed further
+light on the role of high gluon density and saturation dynamics at RHIC and
+LHC.",0808.2769v1
+2008-08-20,Distinct pseudogap and superconducting state quasiparticle relaxation dynamics in near-optimally doped SmFeAsO0.8F0.2 single crystals,"We use femtosecond spectroscopy to investigate the quasiparticle relaxation
+and low-energy electronic structure in a near-optimally doped pnictide
+superconductor with T_c=49.5 K. Multiple relaxation processes are evident, with
+distinct superconducting state quasiparticle (QP) recombination dynamics
+exhibiting a T-dependent superconducting (SC) gap, and a clear ""pseudogap"" (PG)
+-like feature with an onset around 200K indicating the existence of a
+temperature-independent gap of magnitude \Delta_PG= 61 +- 9 meV above T_c. Both
+the SC and PG components show saturation as a function of fluence with distinct
+saturation thresholds ~0.15 \muJ/cm^2 and 1.5 \muJ/cm^2, respectively.",0808.2772v2
+2008-09-19,Polarization proximity effect in isolator crystal pairs,"We experimentally studied the polarization dynamics (orientation and
+ellipticity) of near infrared light transmitted through magnetooptic Yttrium
+Iron Garnet crystal pairs using a modified balanced detection scheme. When the
+pair separation is in the sub-millimeter range, we observed a proximity effect
+in which the saturation field is reduced by up to 20%. 1D magnetostatic
+calculations suggest that the proximity effect originates from magnetostatic
+interactions between the dipole moments of the isolator crystals. This
+substantial reduction of the saturation field is potentially useful for the
+realization of low-power integrated magneto-optical devices.",0809.3292v1
+2008-10-31,The exact probability distribution of saturating states in random sequential adsorption,"We consider the non-overlapping irreversible random sequential adsorption
+(RSA) process on one-dimensional finite line, which is known also as the car
+parking process. The probability of each coverage in saturating states is
+analytically and exactly obtained. In the derivation, a new representation of
+states in RSA process is introduced, which effectively works to make the
+calculation clear and simple.",0810.5632v2
+2008-12-05,Doubly periodic waves of a discrete nonlinear Schrödinger system with saturable nonlinearity,"A system of two discrete nonlinear Schr\""odinger equations of the
+Ablowitz-Ladik type with a saturable nonlinearity is shown to admit a doubly
+periodic wave, whose long wave limit is also derived. As a by-product, several
+new solutions of the elliptic type are provided for NLS-type discrete and
+continuous systems.",0812.1196v1
+2008-12-19,Multipomeron Cuts and Hard Processes on Nuclei,"With nuclear targets comes a new scale into the pQCD description of hard
+processes - the saturation scale. In the saturation regime, the familiar linear
+k_\perp-factorization breaks down and must be replaced by a nonlinear
+k_\perp-factorization, which accounts for absorptive and multiple scattering
+corrections to the hard process. Predictions for partial cross sections
+corresponding to a fixed number of cut Pomerons (the topological cross
+sections) can be obtained in a surprisingly straightforward manner. We discuss
+some applications to deep inelastic scattering.",0812.3802v1
+2009-01-05,Probing the Symmetry Energy with Heavy Ions,"Constraints on the EoS for symmetric matter (equal neutron and proton
+numbers) at supra-saturation densities have been extracted from energetic
+collisions of heavy ions. Collisions of neutron-deficient and neutron-rich
+heavy ions now provide initial constraints on the EoS of neutron-rich matter at
+sub-saturation densities. Comparisons are made to other available constraints.",0901.0412v1
+2009-01-08,Color Glass Condensate and its relation to HERA physics,"I give a brief overview of the effective theory for the Color Glass
+Condensate, which is the high-density gluonic matter which controls high-energy
+scattering in QCD in the vicinity of the unitarity limit. I concentrate on
+fundamental phenomena, like gluon saturation, unitarization, and geometric
+scaling, and the way how these are encoded in the formalism. I emphasize the
+importance of the next-to-leading order corrections, especially the running of
+the coupling, for both conceptual and phenomenological issues. I survey the
+implications of the CGC theory for the HERA physics and its phenomenological
+applications based on saturation models.",0901.0986v1
+2009-02-07,Scaling Laws for Spreading of a Liquid Under Pressure,"We study squeeze flow of two different fluids (castor oil and ethylene
+glycol) between a pair of glass plates and a pair of perspex plates, under an
+applied load. The film thickness is found to vary with time as a power-law,
+where the exponent increases with load. After a certain time interval the area
+of fluid-solid contact saturates to a constant value. This saturation area,
+increases with load at different rates for different fluid-solid combinations.",0902.1222v1
+2009-02-27,Freeness of actions of finite groups on C*-algebras,"We describe some of the forms of freeness of group actions on noncommutative
+C*-algebras that have been used, with emphasis on actions of finite groups. We
+give some indications of their strengths, weaknesses, applications, and
+relationships to each other. The properties discussed include the Rokhlin
+property, K-theoretic freeness, the tracial Rokhlin property, pointwise
+outerness, saturation, hereditary saturation, and the requirement that the
+strong Connes spectrum be the entire dual.",0902.4891v1
+2009-03-16,'Hausdorff distance' via conical cocompletion,"In the context of quantaloid-enriched categories, we explain how each
+saturated class of weights defines, and is defined by, an essentially unique
+full sub-KZ-doctrine of the free cocompletion KZ-doctrine. The KZ-doctrines
+which arise as full sub-KZ-doctrines of the free cocompletion, are
+characterised by two simple ""fully faithfulness"" conditions. Conical weights
+form a saturated class, and the corresponding KZ-doctrine is precisely (the
+generalisation to quantaloid-enriched categories of) the Hausdorff doctrine of
+[Akhvlediani et al., 2009].",0903.2722v2
+2009-03-18,Prediction for unintegrated parton distributions,"Unintegrated parton distributions in the proton and nucleus are predicted by
+a modified DGLAP equation incorporating the shadowing corrections, which
+include exact energy-momentum conservation in each splitting and fusion
+vertices. We find that the nuclear shadowing effects are obvious, although they
+are far from the saturation limit. On the other hand, we point out that the
+suppression of the unintegrated gluon distribution toward lower $k_t^2$ may
+arise from the valence-like input rather than the saturation effects.",0903.3073v2
+2009-04-14,Multiwavelength Passively Mode Locked Fiber Laser: all normal dispersion,"We report on the generation of multiwavelength gain-guided soliton (GGS) in
+an all normal dispersion birefringent fiber laser passively mode-locked with a
+semiconductor saturable absorber mirror (SESAM). Determined by the cavity
+birefringence, we observe the stable single-, dual- and triple- wavelength mode
+locked GGSs, which is a natural consequence of the mutual nonlinear interaction
+among the normal cavity dispersion, cavity fiber nonlinear Kerr effect, laser
+gain saturation and bandwidth limitation resulting from the intra-cavity
+birefringent filter.",0904.2066v2
+2009-04-22,Dispersion and Dispersivity Tensors in Saturated Porous Media with Uniaxial Symmetry,"The coefficients of dispersion, D_{ij}, and the dispersivity, a_{ijkl},
+appear in the expression for the flux of a solute in saturated flow through
+porous media. We present a detailed analysis of these tensors in an axially
+symmetric porous medium and show that in such a medium, the dispersivity is
+governed by 6 independent moduli. We present also the constraints that have to
+be satisfied by these moduli. We also show that at least two independent
+experiments are required in order to obtain the values of these coefficients
+for any three-dimensional porous medium domain.",0904.3447v1
+2009-05-12,Extended Skyrme interaction (I): spin fluctuations in dense matter,"Most of the Skyrme interactions are known to predict spin or isospin
+instabilities beyond the saturation density of nuclear matter which contradict
+predictions based on realistic interactions. A modification of the standard
+Skyrme interaction is proposed so that the ferromagnetic instability is
+removed. The new terms are density dependent and modify only the spin p-h
+interaction in the case of spin-saturated system. Consequences for the nuclear
+response function and neutrino mean free path are shown. The overall effect of
+the RPA correlations makes dense matter more transparent for neutrino
+propagation by a factor of 2 to 10 depending of the density.",0905.1931v2
+2009-06-05,Fano resonances in saturable waveguide arrays,"We study a waveguide array with an embedded nonlinear saturable impurity. We
+solve the impurity problem in closed form and find the nonlinear localized
+modes. Next, we consider the scattering of a small-amplitude plane wave by a
+nonlinear impurity mode, and discover regions in parameter space where
+transmission is fully suppressed. We relate these findings with Fano resonances
+and propose this setup as a mean to control the transport of light across the
+array.",0906.1160v2
+2009-06-16,Rapidity and energy dependence of average transverse momentum and particle density in saturation models,"Saturation models -- colour glass condensate and string percolation -- impose
+a strict relation between the average transverse momentum, <P_T>, and the
+rapidity particle densities, dn/dy. By combining this relation with an
+appropriate evolution equation for dn/dy, and imposing energy-momentum
+conservation, we obtain a fair description of data, for generic AB collisions
+(hadron-hadron, hadron-nucleus and nucleus-nucleus) at all rapidities and
+(high) energies. Predictions are given for the LHC.",0906.2976v1
+2009-10-02,On the saturation sequence of the rational normal curve,"Let $C \subseteq \P^d$ denote the rational normal curve of order $d$. Its
+homogeneous defining ideal $I_C \subseteq \QQ[a_0,...,a_d]$ admits an
+$SL_2$-stable filtration $J_2 \subseteq J_4 \subseteq ... \subseteq I_C$ by
+sub-ideals such that the saturation of each $J_{2q}$ equals $I_C$. Hence, one
+can associate to $d$ a sequence of integers $(\alpha_1,\alpha_2,...)$ which
+encodes the degrees in which the successive inclusions in this filtration
+become trivial. In this paper we establish several lower and upper bounds on
+the $\alpha_q$, using \emph{inter alia} the methods of classical invariant
+theory.",0910.0298v1
+2009-10-02,Saturation in nuclei,"This talk discusses some recent studies of gluon saturation in nuclei. We
+stress the connection between the initial condition in heavy ion collisions and
+observables in deep inelastic scattering (DIS). The dominant degree of freedom
+in the small x nuclear wavefunction is a nonperturbatively strong classical
+gluon field, which determines the initial condition for the glasma fields in
+the initial stages of a heavy ion collision. A correlator of Wilson lines from
+the same classical fields, known as the dipole cross section, can be used to
+compute many inclusive and exclusive observables in DIS.",0910.0402v1
+2009-10-05,Saturation and Critical Phenomena in DIS,"It is argued that the expected turn-down in $x- Q^2$ of the cross sections
+(structure functions $F_2(x,Q^2)$), assumed to result from the saturation of
+parton densities in the nucleon, is related to a phase transition from the
+(almost) ideal partonic gas, obeying Bjorken scaling, to a partonic ""liquid"".
+This can be quantified in the framework of statistical models, percolation and
+other approaches to collective phenomena of the strongly interacting matter.
+Similarities and differences between the case of lepton-hadron, hadron-hadron
+and nuclear collisions are discussed.",0910.0796v1
+2009-10-19,Gluon Saturation Effects at the Nuclear Surface: Inelastic Cross Section of Proton-Nucleus at Ultra High Energy Cosmic Ray domain,"Considering the high-energy limit of the QCD gluon distribution inside a
+nucleus, we calculate the proton-nucleus total inelastic cross section using a
+simplified dipole model. We show that, if gluon saturation occurs in the
+nuclear surface region, the total cross section of proton-nucleus collisions
+increases more rapidly as a function of the incident energy compared to that of
+a Glauber-type estimate. We discuss the implications of this with respect to
+recent ultra-high-energy cosmic ray experiments.",0910.3701v2
+2009-10-21,"Dynamic saturation in semiconductor optical amplifiers: accurate model, role of carrier density, and slow light","We developed an improved model in order to predict the RF behavior and the
+slow light properties of the SOA valid for any experimental conditions. It
+takes into account the dynamic saturation of the SOA, which can be fully
+characterized by a simple measurement, and only relies on material fitting
+parameters, independent of the optical intensity and the injected current. The
+present model is validated by showing a good agreement with experiments for
+small and large modulation indices.",0910.4064v2
+2009-10-26,Current Saturation and Surface Polar Phonon Scattering in Graphene,"We present a study of transport in graphene devices on polar insulating
+substrates using a tight-binding model. The mobility is computed using a
+multiband Boltzmann treatment. We provide the scaling of the surface polar
+phonon contribution to the low-field mobility with carrier density,
+temperature, and distance from the substrate. At high bias, we find that
+graphene self-heating effect is essential to account for the observed saturated
+current behavior. We predict that by optimizing the device cooling, the high
+bias currents can be significantly enhanced.",0910.4665v1
+2009-10-26,Why is the nuclear symmetry energy so uncertain at supra-saturation densities?,"Within the interacting Fermi gas model for isospin asymmetric nuclear matter,
+effects of the in-medium three-body interaction and the two-body short-range
+tensor force due to the $\rho$ meson exchange as well as the short-range
+nucleon correlation on the high-density behavior of the nuclear symmetry energy
+are demonstrated respectively in a transparent way. Possible physics origins of
+the extremely uncertain nuclear symmetry energy at supra-saturation densities
+are discussed.",0910.4803v2
+2009-12-04,Saturated-absorption cavity ring-down spectroscopy,"We report on a novel approach to cavity-ring-down spectroscopy with the
+sample gas in saturated-absorption regime. This technique allows to decouple
+and simultaneously retrieve empty-cavity background and absorption signal, by
+means of a theoretical model that we developed and tested. The high sensitivity
+and frequency precision for spectroscopic applications are exploited to
+measure, for the first time, the hyperfine structure of an excited vibrational
+state of $^{17}$O$^{12}$C$^{16}$O in natural abundance with an accuracy of a
+few parts in $10^{-11}$.",0912.0831v2
+2010-02-28,"Graphene mode locked, wavelength-tunable, dissipative soliton fiber laser","Atomic layer graphene possesses wavelength-insensitive ultrafast saturable
+absorption, which can be exploited as a full-band mode locker. Taking advantage
+of the wide band saturable absorption of the graphene, we demonstrate
+experimentally that wide range (1570 nm - 1600nm) continuous wavelength tunable
+dissipative solitons could be formed in an erbium doped fiber laser mode locked
+with few layer graphene.",1003.0154v1
+2010-03-17,Method for characterizing single photon detectors in saturation regime by cw laser,"We derive an analytical expression for the count probability of a single
+photon detector for a wide range of input optical power that includes
+afterpulsing effects. We confirm the validity of the expression by fitting it
+to the data obtained from a saturated commercial Single Photon Detector by
+illuminating it with a cw laser. Detector efficiency and afterpulsing
+probability extracted from the fits agree with the manufacture specs for low
+repetition frequencies.",1003.3485v1
+2010-05-08,Multi-convex sets in real projective spaces and their duality,"We study intersections of projective convex sets in the sense of Steinitz. In
+a projective space, an intersection of a nonempty family of convex sets splits
+into multiple connected components each of which is a convex set. Hence, such
+an intersection is called a multi-convex set. We derive a duality for saturated
+multi-convex sets: there exists an order anti-isomorphism between nonempty
+saturated multi-convex sets in a real projective space and those in the dual
+projective space. In discrete geometry and computational geometry, these
+results allow to transform a given problem into a dual problem which sometimes
+is easier to solve. This will be pursued in a later paper.",1005.1852v1
+2010-08-16,Drell-Yan process at forward rapidity at the LHC,"We analyze the Drell-Yan lepton pair production at forward rapidity at the
+Large Hadron Collider. Using the dipole framework for the computation of the
+cross section we find a significant suppression in comparison to the collinear
+factorization formula due to saturation effects in the dipole cross section. We
+develop a twist expansion in powers of Q_s^2/M^2 where Q_s is the saturation
+scale and M the invariant mass of the produced lepton pair. For the nominal LHC
+energy the leading twist description is sufficient down to masses of 6 GeV.
+Below that value the higher twist terms give a significant contribution.",1008.2652v1
+2010-08-19,Multiplicity distributions and long range rapidity correlations,"The physics of the initial conditions of heavy ion collisions is dominated by
+the nonlinear gluonic interactions of QCD. These lead to the concepts of parton
+saturation and the Color Glass Condensate (CGC). We discuss recent progress in
+calculating multi-gluon correlations in this framework, prompted by the
+observation that these correlations are in fact easier to compute in a dense
+system (nucleus-nucleus) than a dilute one (proton-proton).",1008.3226v1
+2010-08-26,Exact Solutions of the Two-Dimensional Discrete Nonlinear Schrödinger Equation with Saturable Nonlinearity,"We show that the two-dimensional, nonlinear Schr\""odinger lattice with a
+saturable nonlinearity admits periodic and pulse-like exact solutions. We
+establish the general formalism for the stability considerations of these
+solutions and give examples of stability diagrams. Finally, we show that the
+effective Peierls-Nabarro barrier for the pulse-like soliton solution is zero.",1008.4592v1
+2010-08-26,Staggered and short period solutions of the Saturable Discrete Nonlinear Schrödinger Equation,"We point out that the nonlinear Schr{\""o}dinger lattice with a saturable
+nonlinearity also admits staggered periodic as well as localized pulse-like
+solutions. Further, the same model also admits solutions with a short period.
+We examine the stability of these solutions and find that the staggered as well
+as the short period solutions are stable in most cases. We also show that the
+effective Peierls-Nabarro barrier for the pulse-like soliton solutions is zero.",1008.4594v1
+2010-09-03,"Reduced, tame and exotic fusion systems","We define here two new classes of saturated fusion systems, reduced fusion
+systems and tame fusion systems. These are motivated by our attempts to better
+understand and search for exotic fusion systems: fusion systems which are not
+the fusion systems of any finite group. Our main theorems say that every
+saturated fusion system reduces to a reduced fusion system which is tame only
+if the original one is realizable, and that every reduced fusion system which
+is not tame is the reduction of some exotic (nonrealizable) fusion system.",1009.0622v1
+2010-09-16,"Single and double inclusive particle production in d+Au collisions at RHIC, leading twist and beyond","We discuss the evidence for the presence of QCD saturation effects in the
+data collected in d+Au collisions at RHIC. In particular we focus our analysis
+on forward hadron yields and azimuthal correlations. Approaches alternative to
+the CGC description of these two observables are discussed in parallel.",1009.3215v1
+2010-10-19,Modeling of the Output and Transfer Characteristics of Graphene Field-Effect Transistors,"We obtain the output and transfer characteristics of graphene field-effect
+transistors by using the charge-control model for the current, based on the
+solution of the Boltzmann equation in the field-dependent relaxation time
+approximation. Closed expressions for the conductance, transconductance and
+saturation voltage are derived. We found good agreement with the experimental
+data of Meric et al. [Nature Nanotechnology 3, 684 (2008)] without assuming
+carrier density-dependent velocity saturation.",1010.4037v1
+2010-11-14,Gluon Evolution and Saturation Proceedings,"Almost 40 years ago, Gribov and colleagues at the Leningrad Nuclear Physics
+Institute developed the ideas that led to the
+Dokhsitzer-Gribov-Altarelli-Parisi the Baltisky-Fadin-Kuraev-Lipatov equations.
+These equations describe the evolution of the distributions for quarks and
+gluon inside a hadron to increased resolution scale of a probe or to smaller
+values of the fractional momentum of a hadronic constituent. I motivate and
+discuss the generalization required of these equations needed for high energy
+processes when the density of constituents is large. This leads to a theory of
+saturation realized by the Color Glass Condensate",1011.3202v1
+2010-12-13,A $c_0$ saturated Banach space with tight structure,"It is shown that variants of the HI methods could yield objects closely
+connected to the classical Banach spaces. Thus we present a new $c_0$ saturated
+space, denoted as $\mathfrak{X}_0$, with rather tight structure. The space
+$\mathfrak{X}_0$ is not embedded into a space with an unconditional basis and
+its complemented subspaces have the following structure. Everyone is either of
+type I, namely, contains an isomorph of $\mathfrak{X}_0$ itself or else is
+isomorphic to a subspace of $c_0$ (type II). Furthermore for any analytic
+decomposition of $\mathfrak{X}_0$ into two subspaces one is of type I and the
+other is of type II. The operators of $\mathfrak{X}_0$ share common features
+with those of HI spaces.",1012.2758v1
+2011-01-07,"Fluctuations, Saturation, and Diffractive Excitation at low x","Diffractive excitation is usually described by the Good--Walker formalism for
+low masses, and by the triple-Regge formalism for high masses. In the
+Good-Walker formalism the cross section is determined by the fluctuations in
+the interaction. By taking the fluctuations in the BFKL ladder into account, it
+is possible to describe both low and high mass excitation in the Good-Walker
+formalism. In high energy pp collisions the fluctuations are strongly
+suppressed by saturation, which implies that pomeron exchange does not
+factorise between DIS and pp collisions. The Dipole Cascade Model reproduces
+the expected triple-Regge form for the bare pomeron, and the triple-pomeron
+coupling is estimated.",1101.1404v1
+2011-01-27,Mobility of high-power solitons in saturable nonlinear photonic lattices,"We theoretically study the properties of one-dimensional nonlinear saturable
+photonic lattices exhibiting multiple mobility windows for stationary
+solutions. The effective energy barrier decreases to a minimum in those power
+regions where a new intermediate stationary solution appears. As an
+application, we investigate the dynamics of high-power gaussian-like beams
+finding several regions where the light transport is enhanced.",1101.5354v2
+2011-02-18,Extended Longitudinal Scaling: direct evidence of saturation,"Multiparticle production of charged particles at high energies exhibit the
+phenomenon of Limiting Fragmentation. Furthermore, the region in rapidity over
+which the production of particles appears to be independent of energy,
+increases with energy. It is argued that this phenomenon, known as Extended
+Longitudinal Scaling, is a direct manifestation of some kind of saturation,
+akin to that in the Color Glass Condensate picture of particle production.",1102.3921v1
+2011-03-01,Cycle-saturated graphs with minimum number of edges,"A graph $G$ is called $H$-saturated if it does not contain any copy of $H$,
+but for any edge $e$ in the complement of $G$ the graph $G+e$ contains some
+$H$. The minimum size of an $n$-vertex $H$-saturated graph is denoted by
+$\sat(n,H)$. We prove $$\sat(n,C_k) = n + n/k + O((n/k^2) + k^2)$$ holds for
+all $n\geq k\geq 3$, where $C_k$ is a cycle with length $k$. We have a similar
+result for semi-saturated graphs $$\ssat(n,C_k) = n + n/(2k) + O((n/k^2) +
+k).$$ We conjecture that our three constructions are optimal.",1103.0067v1
+2011-04-14,Jump at the onset of saltation,"We reveal a discontinuous transition in the saturated flux for aeolian
+saltation by simulating explicitly particle motion in turbulent flow. The
+discontinuity is followed by a coexistence interval with two metastable
+solutions. The modification of the wind profile due to momentum exchange
+exhibits a second maximum at high shear strength. The saturated flux depends on
+the strength of the wind as $q_s=q_0+A(u_*-u_t)(u_*^2+u_t^2)$.",1104.2767v2
+2011-04-27,Isomorph-free generation of 2-connected graphs with applications,"Many interesting graph families contain only 2-connected graphs, which have
+ear decompositions. We develop a technique to generate families of unlabeled
+2-connected graphs using ear augmentations and apply this technique to two
+problems. In the first application, we search for uniquely K_r-saturated graphs
+and find the list of uniquely K_4-saturated graphs on at most 12 vertices,
+supporting current conjectures for this problem. In the second application, we
+verifying the Edge Reconstruction Conjecture for all 2-connected graphs on at
+most 12 vertices. This technique can be easily extended to more problems
+concerning 2-connected graphs.",1104.5261v1
+2011-04-28,Inhomogeneous Gain Saturation in EDF: Experiment and Modeling,"Erbium-Doped Fiber Amplifiers can present holes in spectral gain in
+Wavelength Division Multiplexing operation. The origin of this inhomogeneous
+saturation behavior is still a subject of controversy. In this paper we present
+both an experimental methods and a gain's model. Our experimental method allow
+us to measure the first homogeneous linewidth of the 1.5 $\mu$m erbium emission
+with gain spectral hole burning consistently with the other measurement in the
+literature and the model explains the differences observed in literature
+between GSHB and other measurement methods.",1104.5302v1
+2011-05-10,Distribution of linearly polarized gluons inside a large nucleus,"The distribution of linearly polarized gluons inside a large nucleus is
+studied in the framework of the color glass condensate. We find that the
+Weizs\""acker-Williams distribution saturates the positivity bound at large
+transverse momenta and is suppressed at small transverse momenta, whereas the
+dipole distribution saturates the bound for any value of the transverse
+momentum. We also discuss processes in which both distributions of linearly
+polarized gluons can be probed.",1105.1991v2
+2011-05-27,Gluon spectrum in the glasma from JIMWLK evolution,"The JIMWLK equation with a ""daughter dipole"" running coupling is solved
+numerically starting from an initial condition given by the
+McLerran-Venugopalan model. The resulting Wilson line configurations are then
+used to compute the spectrum of gluons comprising the glasma inital state of a
+high energy heavy ion collision. The development of a geometrical scaling
+region makes the spectrum of produced gluons harder. Thus the ratio of the mean
+gluon transverse momentum to the saturation scale grows with energy. Also the
+total gluon multiplicity increases with energy slightly faster than the
+saturation scale squared.",1105.5511v2
+2011-07-05,Proton-proton cross-sections: the interplay between density and radius,"We argue that there are two mechanisms responsable for the growth of high
+energy cross-sections - \sigma_{tot} and \sigma_{el}, say - in pp collisions.
+One is by the increase of matter \emph{density}, resulting in the black disk
+saturation. The other is by exclusively radial expansion affecting the
+periphery of the overlap area. Within this simple model we can reproduce all
+available data in pp from ISR to LHC. In order to achieve a fast growth in the
+very high energy cosmic ray energies, we propose a fast black disk saturation
+followed by the dominance of geometric scaling (GS).",1107.0912v2
+2011-08-03,Open Saturated Sets Without Holonomy,"Open, connected, saturated sets W without holonomy in codimension one
+foliations play key roles as fundamental building blocks. Here, for the case of
+foliated 3-manifolds, we produce a finite system of closed, convex,
+non-overlapping polyhedral cones in the first cohomology of W with real
+coefficients such that the isotopy classes of possible foliations of W without
+holonomy, either dense leaved in W or proper, correspond one-to-one to the rays
+in the interiors of these cones. This generalizes our classification of depth
+one foliations to foliations of finite depth and more general foliations.",1108.0714v3
+2011-09-02,High-energy factorization and evolution with improved kinematics,"The high-energy factorization and the associated B-JIMWLK or BK evolution
+equations are presented, using the example of DIS structure functions. The
+necessity of taking gluon saturation into account is discussed, and also the
+various approximations underlying high-energy factorization. The appearance of
+large NLL corrections in such a framework with or without gluon saturation is
+recalled, and their physical origin is explained. Finally, old and new results
+are presented about the resummation of some of those large corrections, related
+to kinematical approximations.",1109.0547v1
+2011-09-15,Not All Saturated 3-Forests Are Tight,"A basic statement in graph theory is that every inclusion-maximal forest is
+connected, i.e. a tree. Using a definiton for higher dimensional forests by
+Graham and Lovasz and the connectivity-related notion of tightness for
+hypergraphs introduced by Arocha, Bracho and Neumann-Lara in, we provide an
+example of a saturated, i.e. inclusion-maximal 3-forest that is not tight. This
+resolves an open problem posed by Strausz.",1109.3390v1
+2011-10-11,Steady State Solutions of a Mass-Conserving Bistable Equation with a Saturating Flux,"We consider a mass-conserving bistable equation with a saturating flux on an
+interval. This is the quasilinear analogue of the Rubinstein-Steinberg
+equation, suitable for description of order parameter conserving solid-solid
+phase transitions in the case of large spatial gradients in the order
+parameter. We discuss stationary solutions and investigate the change in
+bifurcation diagrams as the mass constraint and the length of the interval are
+varied.",1110.2323v1
+2011-10-28,Physics-Based Compact Modeling of Double-Gate Graphene Field-Effect Transistor Operation Including Description of Two Saturation Modes,"Based on diffusion-drift approximation a version of analytic compact model
+for large-area double-gate graphene field-effect transistor is presented. As
+parts of the model, the electrostatics of double-gate structure is described
+and a unified phenomenological approach for modeling of the two drain current
+saturation modes is proposed.",1110.6319v2
+2011-12-13,High-frequency performance of graphene field effect transistors with saturating IV-characteristics,"High-frequency performance of graphene field-effect transistors (GFETs) with
+boron-nitride gate dielectrics is investigated. Devices show saturating IV
+characteristics and fmax values as high as 34 GHz at 600-nm channel length.
+Bias dependence of fT and fmax and the effect of the ambipolar channel on
+transconductance and output resistance are also examined.",1112.2777v1
+2011-12-16,Countable saturation of corona algebras,"We present unified proofs of several properties of the corona of
+$\sigma$-unital C*-algebras such as AA-CRISP, SAW*, being sub-$\sigma$-Stonean
+in the sense of Kirchberg, and the conclusion of Kasparov's Technical Theorem.
+Although our results were obtained by considering C*-algebras as models of the
+logic for metric structures, the reader is not required to have any knowledge
+of model theory of metric structures (or model theory, or logic in general).
+The proofs involve analysis of the extent of model-theoretic saturation of
+corona algebras.",1112.3898v2
+2012-01-10,Stable nonlinear amplification of solitons without gain saturation,"We demonstrate that the cubic gain applied in a localized region, which is
+embedded into a bulk waveguide with the cubic-quintic nonlinearity and uniform
+linear losses, supports stable spatial solitons in the absence of the quintic
+dissipation. The system, featuring the bistability between the solitons and
+zero state (which are separated by a family of unstable solitons), may be used
+as a nonlinear amplifier for optical and plasmonic solitons, which, on the
+contrary to previously known settings, does not require gain saturation. The
+results are obtained in an analytical form and corroborated by the numerical
+analysis.",1201.2095v1
+2012-02-23,Study of full implicit petroleum engineering finite volume scheme for compressible two phase flow in porous media,"An industrial scheme, to simulate the two compressible phase flow in porous
+media, consists in a finite volume method together with a phase-by-phase
+upstream scheme. The implicit finite volume scheme satisfies industrial
+constraints of robustness. We show that the proposed scheme satisfy the maximum
+principle for the saturation, a discrete energy estimate on the pressures and a
+function of the saturation that denote capillary terms. These stabilities
+results allow us to derive the convergence of a subsequence to a weak solution
+of the continuous equations as the size of the discretization tends to zero.
+The proof is given for the complete system when the density of the each phase
+depends on the own pressure.",1202.5274v1
+2012-03-06,High Frequency Geodesic Acoustic Modes in Electron Temperature Gradient Mode Turbulence,"In this work the first demonstration of a high frequency branch of the
+geodesic acoustic mode (GAM) driven by electron temperature gradient (ETG)
+modes is presented. The work is based on a fluid description of the ETG mode
+retaining non-adiabatic ions and the dispersion relation for high frequency
+GAMs driven nonlinearly by ETG modes is derived. A new saturation mechanism for
+ETG turbulence through the interaction with high frequency GAMs is found,
+resulting in a significantly enhanced ETG turbulence saturation level compared
+to the mixing length estimate.",1203.1174v2
+2012-03-15,Saturation Spectroscopy of Iodine in Hollow-core Optical Fibre,"We present high-resolution spectroscopy of Iodine vapour that is loaded and
+trapped within the core of a hollow-core photonic crystal fibre (HC-PCF). We
+compare the observed spectroscopic features to those seen in a conventional
+iodine cell and show that the saturation characteristics differ significantly.
+Despite the confined geometry it was still possible to obtain sub-Doppler
+features with a spectral width of ~6 MHz with very high contrast. We provide a
+simple theory which closely reproduces all the key observations of the
+experiment.",1203.3346v1
+2012-05-11,Elliptic flow and the symmetry energy at supra-saturation density,"The elliptic flow in collisions of neutron-rich heavy-ion systems at
+intermediate energies emerges as an observable sensitive to the strength of the
+symmetry energy at supra-saturation densities. First results obtained by
+comparing ratios or differences of neutron and hydrogen flows with predictions
+of transport models favor a moderately soft to linear density dependence,
+consistent with ab-initio nuclear-matter theories. Comprehensive data sets of
+high accuracy can be expected to improve our knowledge of the equation of state
+of asymmetric nuclear matter.",1205.2585v2
+2012-05-17,Effect of mechanical stresses on coercive force and saturation remanence of ensemble of dual-phase interacting nanoparticles,"In the dual-phase model of interacting nanoparticles stretching leads to a
+decrease in both coercive force $H_c$ and saturation remanence $I_{rs}$, and
+compression - to their growth. Magnetostatic interaction between particles also
+decreases both $H_c$ and $I_{rs}$. Theoretical analysis was carried out in the
+framework of the dual-phase system of interacting particles on the example of
+nanoparticles $\gamma$-$Fe_2O_3$, epitaxially coated with cobalt.",1205.3870v1
+2012-05-25,Saturation effects on T-cell activation in a model of a multi-stage pathogen,"In previous work, we studied host response to a pathogen which uses a cycle
+of immunologically distinct stages to establish and maintain infection. We
+showed that for generic parameter values, the system has a unique biologically
+meaningful stable fixed point. That paper used a simplified model of T-cell
+activation, making proliferation depend linearly on antigen-T-cell encounters.
+Here we generalize the way in which T-cell proliferation depends on the sizes
+of the antigenic populations. In particular, we allow this response to become
+saturated at high levels of antigen. As a result, we show that this family of
+generalized models shares the same steady-state behavior properties with the
+simpler model contemplated in our previous work.",1205.5735v1
+2012-06-11,"Parton Cascades, Small x, and Saturation in High Energy Collisions","These lecture notes are a combination of two lectures and a contribution to
+the celebration of Andrzej Bia{\l}as' birthday at the LI Cracow School of
+Theoretical Physics in June 2011. I here discuss the dynamics of particle
+production in high energy reactions. It includes parton cascades and
+hadronization in e+e--ann., small x evolution including the Double Leading Log
+approximation and the BFKL equation, saturation at high densities and the BK
+equation, and finally the Lund Dipole Cascade model for high energy collisions,
+which is implemented in the DIPSY MC.",1206.2168v1
+2012-06-29,New Examples of Kochen-Specker Type Configurations on Three Qubits,"A new example of a saturated Kochen-Specker (KS) type configuration of 64
+rays in 8-dimensional space (the Hilbert space of a triple of qubits) is
+constructed. It is proven that this configuration has a tropical dimension 6
+and that it contains a critical subconfiguration of 36 rays. A natural
+multicolored generalisation of the Kochen-Specker theory is given based on a
+concept of an entropy of a saturated configuration of rays.",1206.6999v3
+2012-07-06,A saturation property of structures obtained by forcing with a compact family of random variables,"A method how to construct Boolean-valued models of some fragments of
+arithmetic was developed in Krajicek (2011), with the intended applications in
+bounded arithmetic and proof complexity. Such a model is formed by a family of
+random variables defined on a pseudo-finite sample space. We show that under a
+fairly natural condition on the family (called compactness in K.(2011)) the
+resulting structure has a property that is naturally interpreted as saturation
+for existential types. We also give an example showing that this cannot be
+extended to universal types.",1207.1548v2
+2012-07-13,Asymptotics and scalings for large product-form networks via the Central Limit Theorem,"The asymptotic behaviour of a closed BCMP network, with $n$ queues and $m_n$
+clients, is analyzed when $n$ and $m_n$ become simultaneously large. Our method
+relies on Berry-Esseen type approximations coming in the Central Limit Theorem.
+We construct critical sequences $m^0_n$, which are necessary and sufficient to
+distinguish between saturated and non-saturated regimes for the network.
+Several applications of these results are presented. It is shown that some
+queues can act as bottlenecks, limiting thus the global efficiency of the
+system.",1207.3237v1
+2012-08-08,Strong containment of saturated formations of soluble Lie algebras,"It is shown that, if H,K are saturated formations of soluble Lie algebras
+over a field of non-zero characteristic and H strongly contains K
+non-trivially, then H coincides with the formation generated by the L/N(L) for
+L in H, and that H is not locally defined.",1208.1585v4
+2012-08-30,Ground state of nonlinear Schrodinger systems with saturable nonlinearity,"We prove the existence of ground state in a multidimensional nonlinear
+Schrodinger model of paraxial beam propagation in isotropic local media with
+saturable nonlinearity. Such ground states exist in the form of bright
+counterpropagating solitons. From the proof, a general threshold condition on
+the beam coupling constant for the existence of such fundamental solitons
+follows.",1208.6259v1
+2012-09-25,The Saturation of Several Universal Inequalities in Information-Processing,"In this paper, we characterize the saturation of four universal inequalities
+in quantum information theory, including a variant version of strong
+subadditivity inequality for von Neumann entropy, the coherent information
+inequality, the Holevo quantity and average entropy inequalities. These results
+shed new light on quantum information inequalities.",1209.5545v2
+2012-10-15,Evidence for BFKL and saturation dynamics from di-hadron spectra at the LHC,"We demonstrate that rapidity separated di-hadron spectra in high multiplicity
+proton-proton collisions at the LHC can be quantitatively described by a
+combination of BFKL and saturation dynamics. Based on these results, we predict
+the systematics of di-hadron spectra in proton-nucleus collisions at the LHC.",1210.3890v3
+2012-10-19,Imprinting Quantum Fluctuations on Hydrodynamic Initial Conditions,"Starting from the two-point covariance function derived in [1], we have
+developed a toy model to investigate the effect of gluonic fluctuations on the
+transverse energy profile predicted by MC-KLN Color-Glass Condensate initial
+conditions. We find that the effect of these fluctuations on the eccentricity
+harmonics varies strongly with the correlation length and consequently the
+value of the fixed saturation momentum Qs used in [1]. Using approximate values
+for the minimum and maximum saturation momenta probed at RHIC in Au-Au
+collisions, we estimate the increase in the eccentricity coefficients resulting
+from gluonic fluctuations is as large as 10 to 20 percent in central
+collisions.",1210.5508v1
+2012-10-22,Sudakov Resummation in Small-x Saturation Formalism,"Through an explicit calculation of massive scalar particle (e.g., Higgs
+boson) production in high energy pA collisions up to one-loop order, we
+demonstrate that the Sudakov-type logarithms in hard processes in small-x
+saturation formalism can be systematically separated from the typical small-x
+logarithms. The generic feature of the Sudakov logarithms and all order
+resummation is derived. We further comment on the phenomenological implications
+and extension to other hard processes in the small-x calculations.",1210.5792v1
+2012-12-02,"Linearly polarized, Q-switched Er-doped fiber laser based on reduced graphene oxide saturable absorber","We demonstrate generation of linearly polarized pulses from a passively
+Q-switched Erbium-doped fiber laser. The cavity was designed using only
+polarization maintaining (PM) fibers and components, resulting in linearly
+polarized output beam with degree of polarization (DOP) at the level of 97.6%.
+Reduced graphene oxide (rGO) was used as a saturable absorber for Q-switched
+operation. The laser was capable of delivering 1.85us pulses with 125nJ pulse
+energy at 115kHz repetition rate.",1212.0201v1
+2013-01-04,Gluon saturation at higher orders and improvement of kinematics,"Standard perturbative calculations lead to pathologically large NLO
+corrections to low-$x_{Bj}$ evolution equations like BFKL and BK. Using a more
+refined treatment of kinematics in mixed-space, relevant when gluon saturation
+sets on, one obtains an improved version of the BK equation, resumming to all
+orders the most severe of those large higher order corrections.",1301.0773v1
+2013-02-11,On the consistency of the spindown behavior of young and old pulsars,"We study the spindown of pulsars due to gravitational wave emission and show
+that r-modes in neutron stars provide a quantitative explanation for the
+observed low rotation frequencies of young pulsars if the r-mode saturation
+amplitude is sufficiently large. In contrast for such large saturation
+amplitudes old hadronic millisecond pulsars would spin down much faster than
+observed. We discuss resolutions of this apparent discrepancy that could make
+this mechanism consistent with the observational data.",1302.2649v1
+2013-02-19,An Algorithm for Computing the Limit Points of the Quasi-component of a Regular Chain,"For a regular chain $R$, we propose an algorithm which computes the
+(non-trivial) limit points of the quasi-component of $R$, that is, the set
+$\bar{W(R)} \setminus W(R)$. Our procedure relies on Puiseux series expansions
+and does not require to compute a system of generators of the saturated ideal
+of $R$. We focus on the case where this saturated ideal has dimension one and
+we discuss extensions of this work in higher dimensions. We provide
+experimental results illustrating the benefits of our algorithms.",1302.4688v1
+2013-02-19,A Homological Approach to Factorization,"Mott noted a one-to-one correspondence between saturated multiplicatively
+closed subsets of a domain D and directed convex subgroups of the group of
+divisibility D. With this, we construct a functor between inclusions into
+saturated localizations of D and projections onto partially ordered quotient
+groups of G(D). We use this functor to construct many cochain complexes of
+o-homomorphisms of po-groups. These complexes naturally lead to some
+fundamental structure theorems and some natural homology theory that provide
+insight into the factorization behavior of D.",1302.4759v2
+2013-02-21,On the toric ideal of a matroid,"Describing minimal generating set of a toric ideal is a well-studied and
+difficult problem. In 1980 White conjectured that the toric ideal associated to
+a matroid is equal to the ideal generated by quadratic binomials corresponding
+to symmetric exchanges. We prove White's conjecture up to saturation, that is
+that the saturations of both ideals are equal. In the language of algebraic
+geometry this means that both ideals define the same projective scheme.
+Additionally we prove the full conjecture for strongly base orderable matroids.",1302.5236v3
+2013-03-11,Random packing of spheres in Menger sponge,"Random packing of spheres inside fractal collectors of dimension 2 < d < 3 is
+studied numerically using Random Sequential Adsorption (RSA) algorithm. The
+paper focuses mainly on the measurement of random packing saturation limit.
+Additionally, scaling properties of density autocorrelations in the obtained
+packing are analyzed. The RSA kinetics coefficients are also measured. Obtained
+results allow to test phenomenological relation between random packing
+saturation density and collector dimension. Additionally, performed simulations
+together with previously obtained results confirm that, in general, the known
+dimensional relations are obeyed by systems having non-integer dimension, at
+least for d < 3.",1303.2528v2
+2013-03-26,Random generation of optimal saturated designs,"Efficient algorithms for searching for optimal saturated designs are widely
+available. They maximize a given efficiency measure (such as D-optimality) and
+provide an optimum design. Nevertheless, they do not guarantee a \emph{global}
+optimal design. Indeed, they start from an initial random design and find a
+local optimal design. If the initial design is changed the optimum found will,
+in general, be different. A natural question arises. Should we stop at the
+design found or should we run the algorithm again in search of a better design?
+This paper uses very recent methods and software for discovery probability to
+support the decision to continue or stop the sampling. A software tool written
+in SAS has been developed.",1303.6529v2
+2013-05-03,Harmonics suppression effect of the quasi-periodic undulator in SASE free-electron-laser,"In this paper, the harmonics suppression effect of QPUs in SASE FEL is
+investigated. The numerical results show that the harmonics power is reduced by
+using QPUs, but the fundamental radiation power also has a pronounced decrease
+as the saturation length gets very long. The cases of employing QPUs as parts
+of undulators are studied. The calculations show that if the fraction of QPUs
+and their offgap are appropriate in an undulator system, the harmonics
+radiation could be suppressed remarkably, meanwhile the fundamental saturation
+length does not increase too much.",1305.0694v1
+2013-05-17,A characterization of saturated fusion systems over abelian 2-groups,"Given a saturated fusion system $\mathcal{F}$ over a $2$-group $S$, we prove
+that $S$ is abelian provided any element of $S$ is $\mathcal{F}$-conjugate to
+an element of $Z(S)$. This generalizes a Theorem of Camina--Herzog, leading to
+a significant simplification of its proof. More importantly, it follows that
+any $2$-block $B$ of a finite group has abelian defect groups if all
+$B$-subsections are major. Furthermore, every $2$-block with a symmetric stable
+center has abelian defect groups.",1305.4139v2
+2013-05-20,Antiferromagnetic Ising model saturation field entropies: ladders and kagome lattice,"Saturation field entropies of antiferromagnetic Ising models on quasi
+one-dimensional lattices (ladders) and the kagome lattice are calculated. The
+former is evaluated exactly by constructing the corresponding transfer
+matrices, while the latter calculation uses Binder's algorithm for efficiently
+and exactly computing the partition function of over 1300 spins to give, in
+Boltzmann's units, S = 0.393589(6). We comment on the relation of the kagome
+lattice to the experimental situation in the spin-ice compound dysprosium
+titanium oxide.",1305.4606v2
+2013-06-30,Electric Field Effect Thermoelectric Transport in Individual Silicon and Germanium/Silicon Nanowire,"We have simultaneously measured conductance and thermoelectric power (TEP) of
+individual silicon and germanium/silicon core/shell nanowires in the field
+effect transistor device configuration. As the applied gate voltage changes,
+the TEP shows distinctly different behaviors while the electrical conductance
+exhibits the turn-off, subthreshold, and saturation regimes respectively. At
+room temperature, peak TEP value of $\sim 300 \mu$V/K is observed in the
+subthreshold regime of the Si devices. The temperature dependence of the
+saturated TEP values are used to estimate the carrier doping of Si nanowires.",1307.0249v1
+2013-07-02,Saturations of powers of certain determinantal ideals,"Let $R$ be a Noetherian local ring and $m$ a positive integer. Let $I$ be the
+ideal of $R$ generated by the maximal minors of an $m \times (m + 1)$ matrix
+$M$ with entries in $R$. Assuming that the grade of the ideal generated by the
+$k$-minors of $M$ is at least $m - k + 2$ for $1 \leq \forall k \leq m$, we
+will study the associated primes of $I^n$ for $\forall n > 0$. Moreover, we
+compute the saturation of $I^n$ for $1 \leq \forall n \leq m$ in the case where
+$R$ is a Cohen-Macaulay ring and the entries of $M$ are powers of elements that
+form an sop for $R$.",1307.0593v1
+2013-07-18,"Tectonic ""short circuit"" of sub-horizontal fluid-saturated bodies as a possible mechanism of the earthquake","An alternative earthquake mechanism is proposed. The traditional stress
+mechanism of fracture formation assigned a support role. As a proximate cause
+of the earthquake the destruction of the roofs of sub-horizontal
+fluid-saturated bodies (SHFB) is considered. This collapse may occur due to
+redistribution of fluid pressure within the system of SHFB connected by cracks
+(tectonic or other nature). It can cause both shifts of rock blocks
+contributing to seismic shocks and various effects characteristic of foreshocks
+and aftershocks.",1307.4915v1
+2013-10-09,Saturation of Concurrent Collapsible Pushdown Systems,"Multi-stack pushdown systems are a well-studied model of concurrent
+computation using threads with first-order procedure calls. While, in general,
+reachability is undecidable, there are numerous restrictions on stack behaviour
+that lead to decidability. To model higher-order procedures calls, a
+generalisation of pushdown stacks called collapsible pushdown stacks are
+required. Reachability problems for multi-stack collapsible pushdown systems
+have been little studied. Here, we study ordered, phase-bounded and
+scope-bounded multi-stack collapsible pushdown systems using saturation
+techniques, showing decidability of control state reachability and giving a
+regular representation of all configurations that can reach a given control
+state.",1310.2631v1
+2013-10-17,Countable Degree-1 Saturation of Certain C*-Algebras Which Are Coronas of Banach Algebras,"We study commutants modulo some normed ideal of n-tuples of operators which
+satisfy a certain approximate unit condition relative to the ideal. We obtain
+results about the quotient of these Banach algebras by their ideal of compact
+operators being C*-algebras which have the countable degree-1 saturation
+property in the model-theory sense of I. Farah and B. Hart. We also obtain
+results about quasicentral approximate units, multipliers and duality.",1310.4862v1
+2013-10-28,Phase noise of oscillators with unsaturated amplifiers,"We study the role of amplifier saturation in eliminating feedback noise in
+self-sustained oscillators. We extend previous works that use a saturated
+amplifier to quench fluctuations in the feedback magnitude, while
+simultaneously tuning the oscillator to an operational point at which the
+resonator nonlinearity cancels fluctuations in the feedback phase. We consider
+a generalized model which features an amplitude-dependent amplifier gain
+function. This allows us to determine the total oscillator phase noise in
+realistic configurations due to noise in both quadratures of the feedback, and
+to show that it is not necessary to drive the resonator to large oscillation
+amplitudes in order to eliminate noise in the phase of the feedback.",1310.7524v1
+2013-12-09,Sub-Doppler resonances in the back-scattered light from random porous media infused with Rb vapor,"We report on the observation of sub-Doppler resonances on the back-scattered
+light from a random porous glass medium with rubidium vapor filling its
+interstices. The sub-Doppler spectral lines are the consequence of saturated
+absorption where the incident laser beam saturates the atomic medium and the
+back-scattered light probes it. Some specificities of the observed spectra
+reflect the transient atomic evolution under confinement inside the pores.
+Simplicity, robustness and potential miniaturization are appealing features of
+this system as a spectroscopic reference.",1312.2599v1
+2014-01-04,$D$-optimal saturated designs: a simulation study,"In this work we focus on saturated $D$-optimal designs. Using recent results,
+we identify $D$-optimal designs with the solutions of an optimization problem
+with linear constraints. We introduce new objective functions based on the
+geometric structure of the design and we compare them with the classical
+$D$-efficiency criterion. We perform a simulation study. In all the test cases
+we observe that designs with high values of $D$-efficiency have also high
+values of the new objective functions.",1401.0844v1
+2014-01-21,Next-to-leading order improved perturbative QCD + saturation + hydrodynamics model for A+A collisions,"We calculate initial conditions for the hydrodynamical evolution in
+ultrarelativistic heavy-ion collisions at the LHC and RHIC in an improved
+next-to-leading order perturbative QCD + saturation framework. Using viscous
+relativistic hydrodynamics, we show that we obtain a good simultaneous
+description of the centrality dependence of charged particle multiplicities,
+transverse momentum spectra and elliptic flow at the LHC and at RHIC. In
+particular, we discuss how the temperature dependence of the shear viscosity is
+constrained by these data.",1401.5319v1
+2014-01-26,Rigidity of continuous quotients,"We study countable saturation of the metric reduced products and introduce
+continuous fields of metric models indexed by locally compact, separable,
+completely metrizable spaces. Saturation of the reduced product depends both on
+the underlying index space and the model. By using the Gelfand--Naimark duality
+we conclude that the assertion that the \vCech--Stone remainder of the
+half-line has only trivial automorphisms is independent from ZFC. The
+consistency of this statement follows from Proper Forcing Axiom and this is the
+first known example of a connected space with this property.",1401.6689v2
+2014-02-07,Analysis of a mosquito-borne epidemic model with vector stages and saturating forces of infection,"We study a mosquito-borne epidemic model where the vector population is
+distinct in aquatic and adult stages and a saturating effect of disease
+transmission is assumed to ocurr when the number of infectious (humans and
+mosquitoes) becomes large enough. Several techniques, including center manifold
+analysis and sensitivity analysis, have been used to reveal relevant features
+of the model dynamics. We determine the existence of stability-instability
+thresholds and the individual role played in such thresholds by the model
+parameters.",1402.1719v1
+2014-02-08,Periodic Behaviors in Constrained Multi-agent Systems,"In this paper, we provide two discrete-time multi-agent models which generate
+periodic behaviors. The first one is a multi-agent system of identical double
+integrators with input saturation constraints, while the other one is a
+multi-agent system of identical neutrally stable system with input saturation
+constraints. In each case, we show that if the feedback gain parameters of the
+local controller satisfy a certain condition, the multi-agent system exhibits a
+periodic solution.",1402.1862v1
+2014-04-01,Saturated absorption at nanowatt power levels using metastable xenon in a high-finesse optical cavity,"Strong saturated absorption at nanowatt power levels has been demonstrated
+using metastable xenon in a high-finesse optical cavity. The use of metastable
+xenon allows a high quality factor of Q=2*10^8 to be achieved at relatively
+high atomic densities without any contamination or damage to the optical
+surfaces, which is often a problem when using high-density rubidium or other
+alkali atoms. This technique provides a relatively straightforward way to
+produce nonlinearities at the single-photon level with possible applications in
+quantum communications and computing.",1404.0376v2
+2014-04-22,Hosing Instability Suppression in Self-Modulated Plasma Wakefields,"We show that the hosing instability can be suppressed after the saturation of
+the self-modulation instability of a long particle bunch if the plasma density
+perturbation is linear. We derive scalings for maximum bunch tilts and seeds
+for the self-modulation instability to ensure stable propagation beyond
+saturation of self-modulation. Numerical solutions of the reduced hosing
+equations and three-dimensional particle-in-cell simulations confirm our
+analytical findings. Our results may also apply when a train of particle
+bunches or laser pulses excites a linear wake.",1404.5387v1
+2014-05-13,Influence of the ESR saturation on the power sensitivity of cryogenic sapphire resonators,"Here, we study the paramagnetic ions behavior in presence of a strong
+microwave electromagnetic field sustained inside a cryogenic sapphire
+whispering gallery mode resonator. The high frequency measurement resolution
+that can be now achieved by comparing two CSOs permit for the first time to
+observe clearly the non-linearity of the resonator power sensitivity. These
+observations that in turn allow us to optimize the CSO operation, are well
+explained by the Electron Spin Resonance (ESR) saturation of the paramagnetic
+impurities contained in the sapphire crystal.",1405.3081v1
+2014-05-27,Cavity controlled spectral singularity,"We study theoretically a PT-symmetric saturable balanced gain-loss system in
+a ring cavity configuration. The saturable gain and loss are modeled by
+two-level medium with or without population inversion. We show that the
+specifics of the spectral singularity can be fully controlled by the cavity and
+the atomic detuning parameters. The theory is based on the mean-field
+approximation as in standard theory of optical bistability. Further, in the
+linear regime we demonstrate the regularization of the singularity in detuned
+systems, while larger input power levels are shown to be adequate to limit the
+infinite growth in absence of detuning",1405.6812v1
+2014-06-04,Non linear evolution: revisiting the solution in the saturation region,"In this paper we revisit the problem of the solution to Balitsky-Kovchegov
+equation deeply in the saturation domain. We find that solution has the form of
+Levin-Tuchin solution but it depends on variable $\bar{z} = \ln(r^2 Q^2_s) +
+\mbox{Const}$ and the value of $\mbox{Const}$ is calculated in this paper. We
+propose the solution for full BFKL kernel at large $z$ in the entire kinematic
+region that satisfies the McLerram-Venugopalan initial condition",1406.1212v1
+2014-06-12,The primitive equations of the atmosphere in presence of vapor saturation,"A modification of the classical primitive equations of the atmosphere is
+considered in order to take into account important phase transition phenomena
+due to air saturation and condensation. We provide a mathematical formulation
+of the problem that appears to be new in this setting, by making use of
+differential inclusions and variational inequalities, and which allows to
+develop a rather complete theory for the solutions to what turns out to be a
+nonlinearly coupled system of non-smooth partial differential equations.
+Specifically we prove global existence of quasi-strong and strong solutions,
+along with uniqueness results and maximum principles of physical interest.",1406.3165v1
+2014-04-30,From minijet saturation to global observables in A + A collisions at the LHC and RHIC,"We review the recent results from the computation of saturated
+next-to-leading order perturbative QCD minijet intial conditions combined with
+viscous hydrodynamical evolution of ultrarelativistic heavy-ion collisions at
+the LHC and RHIC. Comparison with experimental data is shown.",1406.4760v1
+2014-07-10,Coherent backscattering of intense light by cold atoms with degenerate energy levels: Diagrammatic treatment,"We present a generalization of the diagrammatic pump-probe approach to
+coherent backscattering (CBS) of intense laser light for atoms with degenerate
+energy levels. We employ this approach for a characterization of the double
+scattering signal from optically pumped atoms with the transition
+$J_g\rightarrow J_e=J_g+1$ in the helicity preserving polarization channel. We
+show that, in the saturation regime, the internal degeneracy becomes manifest
+for atoms with $J_g\geq 1$, leading to a faster decrease of the CBS enhancement
+factor with increasing saturation parameter than in the non-degenerate case.",1407.2841v1
+2014-08-08,Saturation of Generalized Partially Hyperbolic Attractors,"We prove the saturation of a generalized partially hyperbolic attractor of a
+$C^2$ map. As a consequence, we show that any generalized partially hyperbolic
+horseshoe-like attractor of a $C^1$-generic diffeomorphism has zero volume. In
+contrast, by modification of Poincar\'e cross section of the geometric model,
+we build a $C^1$-diffeomorphism with a partially hyperbolic horseshoe-like
+attractor of positive volume.",1408.1835v4
+2014-08-30,Quantum friction,"We investigate the van der Waals friction between graphene and an amorphous
+SiO$_2$ substrate. We find that due to this friction the electric current is
+saturated at a high electric field, in agreement with experiment. The
+saturation current depends weakly on the temperature, which we attribute to the
+quantum friction between the graphene carriers and the substrate optical
+phonons. We calculate also the frictional drag between two graphene sheets
+caused by van der Waals friction, and find that this drag can induce a voltage
+high enough to be easily measured experimentally.",1409.0145v1
+2014-09-25,Momentum-resolved study of the saturation intensity in multiple ionization,"We present a momentum-resolved study of strong field multiple ionization of
+ionic targets. Using a deconvolution method we are able to reconstruct the
+electron momenta from the ion momentum distributions after multiple ionization
+up to four sequential ionization steps. This technique allows an accurate
+determination of the saturation intensity as well as of the electron release
+times during the laser pulse. The measured results are discussed in comparison
+to typically used models of over-the-barrier ionization and tunnel ionization.",1409.7251v2
+2014-10-27,Energy and particle currents in a driven integrable system,"We study the ratio of the energy and particle currents ($j^E/j^N$) in an
+integrable one dimensional system of interacting fermions. Both currents are
+driven by a finite (nonzero) dc electric field. In doped insulators, where the
+local conserved quantities saturate the so called Mazur bound on the charge
+stiffness, $j^E/j^N$ agrees with the linear--response theory, even though such
+agreement may be violated for each current alone. However, in the metallic
+regime with a non-saturated Mazur bound, the ratio $j^E/j^N$ in a driven system
+is shown to be much larger than predicted by the linear--response theory.",1410.7262v1
+2014-11-28,Saturation and associated primes of powers of edge ideals,"For the edge ideal I of an arbitrary simple graph G we describe the monomials
+of the saturation of a power of I in terms of (vertex) weighted graphs
+associated with the monomials. This description allows us to characterize the
+embedded associated primes of a power of I as covers of G which contain certain
+types of subgraphs of G. As an application, we completely classify the
+associated primes of the second and the third power of I in terms of G.",1411.7740v1
+2014-12-02,Large $\mathbf{b}$ behaviour in the CGC/saturation approach: BFKL equation with pion loops,"In this paper we proposed a solution to the longstanding problem of the
+CGC/saturation approach: the power-like fall of the scattering amplitudes at
+large $b$. This decrease leads to the violation of the Froissart theorem and
+makes the approach theoretically inconsistent. We showed in the paper that sum
+of the pion loops results in the exponential fall of the scattering amplitude
+at large impact parameters and in the restoration of the Froissart theorem.",1412.0893v1
+2014-12-06,Twist expansion of differential cross-sections of forward Drell-Yan process,"Forward Drell-Yan process at the LHC is a sensitive tool for investigating
+higher twist effects in QCD. The expansion of all Drell-Yan structure functions
+is performed assuming GBW saturation model and the saturation scale plays the
+role of the hadronic scale of OPE. We show that the Lam-Tung relation is broken
+at twist 4. The results open the way for a forthcoming analysis of multiple
+scattering and higher twist effects.",1412.2289v1
+2015-01-21,Multi-plasmon absorption in graphene,"We show that graphene possesses a strong nonlinear optical response in the
+form of multi-plasmon absorption, with exciting implications in classical and
+quantum nonlinear optics. Specifically, we predict that graphene nano-ribbons
+can be used as saturable absorbers with low saturation intensity in the
+far-infrared and terahertz spectrum. Moreover, we predict that two-plasmon
+absorption and extreme localization of plasmon fields in graphene nano-disks
+can lead to a plasmon blockade effect, in which a single quantized plasmon
+strongly suppresses the possibility of exciting a second plasmon.",1501.05258v1
+2015-01-22,Permanent versus determinant: not via saturations,"Let Det_n denote the closure of the GL_{n^2}(C)-orbit of the determinant
+polynomial det_n with respect to linear substitution. The highest weights
+(partitions) of irreducible GL_{n^2}(C)-representations occurring in the
+coordinate ring of Det_n form a finitely generated monoid S(Det_n). We prove
+that the saturation of S(Det_n) contains all partitions lambda with length at
+most n and size divisible by n. This implies that representation theoretic
+obstructions for the permanent versus determinant problem must be holes of the
+monoid S(Det_n).",1501.05528v2
+2015-01-25,Stability and bifurcation analysis of a SIR model with saturated incidence rate and saturated treatment,"We study the dynamics of a SIR epidemic model with nonlinear incidence rate,
+vertical transmission vaccination for the newborns and the capacity of
+treatment, that takes into account the limitedness of the medical resources and
+the efficiency of the supply of available medical resources. Under some
+conditions we prove the existence of backward bifurcation, the stability and
+the direction of Hopf bifurcation. We also explore how the mechanism of
+backward bifurcation affects the control of the infectious disease. Numerical
+simulations are presented to illustrate the theoretical findings.",1501.06179v1
+2015-02-10,Quantum bounds on heat transport through nanojunctions,"We derive rigorous quantum mechanical bounds for the heat current through a
+nanojunction connecting two thermal baths at different temperatures. Based on
+exact sum rules, these bounds compliment the well-known quantum of thermal
+conductance $\kappa_Q \equiv \pi k^2_B T/6\hbar$, which provides a bound for
+low-temperature heat transport in all systems, but is saturated only for
+noninteracting transport. In contrast, our bounds are saturated at high
+temperatures---but still in the quantum regime---, even when interactions are
+very strong. We evaluate these bounds for harmonic and strongly anharmonic
+junction models and compare with numerical approaches.",1502.03095v2
+2015-04-05,Measuring Method of a Surface Property inside the Pore: Application of Kelvin's equation,"Surface analyses inside the nanopore, micropore, and a very narrow pipe are
+important topics for development of the chemical engineering. Here, we propose
+a measuring method which evaluates the surface coverage of the chemically
+modified pore surface and the corrosion rate of the inner surface of the narrow
+pipe, etc. The method uses Kelvin's equation that expresses saturated vapor
+pressure of a liquid in the pore (pipe). The surface coverage and the corrosion
+rate are calculated by measuring saturated vapor pressure of the liquid in the
+pore and the pipe, respectively. In this letter, we explain the concept of the
+method briefly.",1504.01114v1
+2015-05-11,Hartman-Fletcher effect for array of complex barriers,"We calculate the time taken by a wave packet to tunnel through a series of
+complex barrier potentials using stationary phase method to show its saturation
+(Hartman-Fletcher effect) with number of barriers in various situations. We
+numerically study the effect of the coupling between the elastic and inelastic
+channels, width of the individual barrier, separation between the consecutive
+barriers on the saturation of tunneling time. Nature of HF effect has further
+been investigated for more realistic barriers with random inelasticity and also
+for emissive inelastic channels.",1505.03163v1
+2015-05-18,On sets of graded attribute implications with witnessed non-redundancy,"We study properties of particular non-redundant sets of if-then rules
+describing dependencies between graded attributes. We introduce notions of
+saturation and witnessed non-redundancy of sets of graded attribute
+implications are show that bases of graded attribute implications given by
+systems of pseudo-intents correspond to non-redundant sets of graded attribute
+implications with saturated consequents where the non-redundancy is witnessed
+by antecedents of the contained graded attribute implications. We introduce an
+algorithm which transforms any complete set of graded attribute implications
+parameterized by globalization into a base given by pseudo-intents.
+Experimental evaluation is provided to compare the method of obtaining bases
+for general parameterizations by hedges with earlier graph-based approaches.",1505.04677v1
+2015-06-19,Complexity of a Disjoint Matching Problem on Bipartite Graphs,"We consider the following question: given an $(X,Y)$-bigraph $G$ and a set $S
+\subset X$, does $G$ contain two disjoint matchings $M_1$ and $M_2$ such that
+$M_1$ saturates $X$ and $M_2$ saturates $S$? When $|S|\geq |X|-1$, this
+question is solvable by finding an appropriate factor of the graph. In
+contrast, we show that when $S$ is allowed to be an arbitrary subset of $X$,
+the problem is NP-hard.",1506.06157v1
+2015-06-22,Reassessing nuclear matter incompressibility and its density dependence,"Experimental giant monopole resonance energies are now known to constrain
+nuclear incompressibility of symmetric nuclear matter $K$ and its density slope
+$M$ at a particular value of sub-saturation density, the crossing density
+$\rho_c$. Consistent with these constraints, we propose a reasonable way to
+construct a plausible equation of state of symmetric nuclear matter in a broad
+density region around the saturation density $\rho_0$. Help of two additional
+empirical inputs, the value of $\rho_0$ and that of the energy per nucleon
+$e(\rho_0)$ are needed. The value of $K(\rho_0)$ comes out to be $211.9\pm
+24.5$ MeV.",1506.06461v1
+2015-07-16,On the physical DGLAP evolution of structure functions and its dependence on the renormalization scale,"Physical anomalous dimensions are a formulation of the DGLAP evolution of
+Deep Inelastic structure functions which is independent of factorization scheme
+and -scale. In this proceedings we provide an outlook on possible applications,
+in particular in the search of saturation effects. As an original contribution
+we present a short study of the renormalization scale dependence of physical
+evolved structure functions for large initial scale $Q_0^2=30$GeV$^2$",1507.04427v1
+2015-07-24,The behavior of the heavy-quarks structure functions at small-$x$,"The behavior of the charm and bottom structure functions
+($F_{k}^{i}(x,Q^{2})$, i=c,b; k=2,L) at small-$x$ is considered with respect to
+the hard-Pomeron and saturation models. Having checked that this behavior
+predicate the heavy flavor reduced cross sections concerning the unshadowed and
+shadowed corrections. We will show that the effective exponents for the
+unshadowed and saturation corrections are independent of $x$ and $Q^{2}$, and
+also the effective coefficients are dependent to $\ln{Q^{2}}$ compared to
+Donnachie-Landshoff (DL) and color dipole (CD) models.",1507.06770v1
+2015-07-29,Geometrical Scaling in Inelastic Inclusive Particle Production at the LHC,"Analyzing recent ALICE data on inelastic pp scattering at the LHC energies we
+show that charged particle distributions exhibit geometrical scaling (GS). We
+show also that the inelastic cross-section is scaling as well and that in this
+case the quality of GS is better than for multiplicities. Moreover, exponent
+$\lambda$ characterizing the saturation scale is for the cross-section scaling
+compatible with the one found in deep inelastic ep scattering at HERA. Next, by
+parametrizing charged particles distributions by the Tsallis-like formula, we
+find a somewhat unexpected solution that still exhibits GS, but differs from
+the ""standard"" one where the Tsallis temperature is proportional to the
+saturation scale.",1507.08186v1
+2015-08-12,Components of V(ρ)\otimes V(ρ),"Kostant asked the following question:
+  Let $\mathfrak{g}$ be a simple Lie algebra over the complex numbers. Let
+$\lambda$ be a dominant integral weight. Then, $V(\lambda)$ is a component of $
+V(\rho)\otimes V(\rho)$ if and only if $\lambda \leq 2\rho$ under the usual
+Bruhat-Chevalley order on the set of weights.
+  We give an affirmative answer to this question up to a saturation factor. In
+particular, the question is answered affirmatively for the special linear Lie
+algebras due to the Saturation Theorem of Knutson-Tao.",1508.03071v1
+2015-08-26,Voltage quench dynamics of a Kondo system,"We examine the dynamics of a correlated quantum dot in the mixed valence
+regime. We perform numerically exact calculations of the current after a
+quantum quench from equilibrium by rapidly applying a bias voltage in a wide
+range of initial temperatures. The current exhibits short equilibration times
+and saturates upon the decrease of temperature at all times, indicating Kondo
+behavior both in the transient regime and in steady state. The time-dependent
+current saturation temperature matches the Kondo temperature at small times or
+small voltages; a substantially increased value is observed outside of linear
+response. These signatures are directly observable by experiments in the
+time-domain.",1508.06633v1
+2015-09-23,Maharam-Types and Lyapunov's Theorem for Vector Measures on Locally Convex Spaces without Control Measures,"We formulate the saturation property for vector measures in lcHs as a
+nonseparability condition on the derived Boolean $\sigma$-algebras by drawing
+on the topological structure of vector measure algebras. We exploit a
+Pettis-like notion of vector integration in lcHs, the
+Bourbaki--Kluv\'anek--Lewis integral, to derive an exact version of the
+Lyapunov convexity theorem in lcHs without the BDS property. We apply our
+Lyapunov convexity theorem to the bang-bang principle in Lyapunov control
+systems in lcHs to provide a further characterization of the saturation
+property.",1509.06965v1
+2015-11-11,Probing proton fluctuations with asymmetric rapidity correlations,"Intrinsic fluctuations of the proton saturation momentum generate asymmetric
+rapidity distributions on an event-by-event basis. We argue that the asymmetric
+component, $\left<a_1^2\right>$, of the orthogonal polynomial decomposition of
+the two-particle rapidity correlation function is a sensitive probe to this
+distribution of fluctuations. We present a simple model connecting the
+experimentally measured $\left<a_1^2\right>$ to the variance, $\sigma$, of the
+distribution of the logarithm of the proton saturation scale. We find that
+$\sigma\approx 0. 5-1$ describes the asymmetric component of the rapidity
+correlations recently measured by the ATLAS collaboration.",1511.03620v2
+2015-11-26,A Discussion on the Transmission Conditions for Saturated Fluid Flow Through Porous Media With Fractal Microstructure,"The present work is aimed to find suitable exchange conditions for saturated
+fluid flow in a porous medium, when a fractal microstructure is embedded in the
+porous matrix. Two different deterministic models are introduced and rigorously
+analyzed. Also, numerical experiments for each of them are presented to verify
+the theoretically predicted behavior of the phenomenon and some probabilistic
+versions are explored numerically, to gain further insight on the phenomenon.",1511.08511v4
+2016-01-27,Deep Saturated Free Electron Laser Oscillators and Frozen Spikes,"We analyze the behavior of Free Electron Laser (FEL) oscillators operating in
+the deep saturated regime and point out the formation of sub-peaks of the
+optical pulse. They are very stable configurations, having a width
+corresponding to a coherence length. We speculate on the physical mechanisms
+underlying their growth and attempt an identification with FEL mode locked
+structures associated with Super Modes. Their impact on the intra-cavity
+nonlinear harmonic generation is also discussed along with the possibility of
+exploiting them as cavity out-coupler.",1601.07372v1
+2016-03-14,Evidence of strong proton shape fluctuations from incoherent diffraction,"We show within the saturation framework that measurements of exclusive vector
+meson production at high energy provide evidence for strong geometric
+fluctuations of the proton. In comparison, the effect of saturation scale and
+color charge fluctuations is weak. This knowledge will allow detailed future
+measurements of the incoherent cross section to tightly constrain the
+fluctuating geometry of the proton as a function of the parton momentum
+fraction $x$.",1603.04349v2
+2016-03-15,"Microcavity with saturable nonlinearity under simultaneous resonant and nonresonant pumping: multistability, Hopf bifurcations and chaotic behaviour","We studied optical response of microcavity non-equilibrium exciton-polariton
+Bose-Einstein condensate with saturable nonlinearity under simultaneous
+resonant and non-resonant pumping. We demonstrated the emergence of
+multistabile behavior due to the satutration of the excitonic absorbtion.
+Stable periodic Rabi- type oscillations of the excitonic and photonic
+condensate components in the regime of the stationary pump and their transition
+to the chaotic dynamics through the cascade of Hopf bifurcations by tuning of
+the electrical pump are revealed.",1603.04612v1
+2016-04-14,A numerical study of two-phase flow models with dynamic capillary pressure and hysteresis,"Saturation overshoot and pressure overshoot are studied by incorporating
+dynamic capillary pressure, capillary pressure hysteresis and hysteretic
+dynamic coefficient with a traditional fractional flow equation in one
+dimension. Using the method of lines, the discretizations are constructed by
+applying Castillo-Grone's mimetic operators in the space direction and explicit
+trapezoidal integrator in the time direction. Convergence tests and
+conservation property of the schemes are presented. Computed profiles capture
+both the saturation overshoot and pressure overshoot phenomena. Comparisons
+between numerical results and experiments illustrate the effectiveness and
+different features of the models.",1604.04109v3
+2016-04-24,Integrable nonlinear parity-time symmetric optical oscillator,"The nonlinear dynamics of a balanced parity-time symmetric optical microring
+arrangement are analytically investigated. By considering gain and loss
+saturation effects, the pertinent conservation laws are explicitly obtained in
+the Stokes domain-thus establishing integrability. Our analysis indicates the
+existence of two regimes of oscillatory dynamics and frequency locking, both of
+which are analogous to those expected in linear parity-time symmetric systems.
+Unlike other saturable parity time symmetric systems considered before, the
+model studied in this work first operates in the symmetric regime and then
+enters the broken parity-time phase.",1604.07072v1
+2016-05-20,Initial stage of cavitation in liquids and its observation by Rayleigh scattering,"A theory is developed for the initial stage of cavitation in the framework of
+Zel'dovich-Fisher theory of nucleation in the field of negative pressure, while
+taking into account the surface tension dependence on the nanopore radius. A
+saturation mechanism is proposed that limits the exponential dependence of the
+nucleation rate on the energy required to create nanopores. An estimate of the
+saturated density of nanopores at the nucleation stage is obtained. It is shown
+that Rayleigh scattering can detect nanopores arising at the initial stage of
+cavitation development.",1605.06469v1
+2016-05-28,Saturation and bistability of defect-mode intersubband polaritons,"In this article we report about linear and nonlinear optical properties of
+intersubband cavity polariton samples, where the resonant photonic mode is a
+defect state in a metallo-dielectric photonic crystal slab. By tuning a single
+geometric parameter of the resonator, the cavity Q-factor can reach values as
+large as 85, with a consequent large cooperativity for the light-matter
+interaction. We show that a device featuring large cooperativity leads to sharp
+saturation, or even bistability, of the polariton states. This nonlinear
+dynamics occurs at the crossover between the weak and the strong coupling
+regimes, where the weak critical coupling concept plays a fundamental role.",1605.08893v1
+2016-06-28,"Velocity shear, turbulent saturation, and steep plasma gradients in the scrape-off layer of inner-wall limited tokamaks","The narrow power decay-length ($\lambda_q$), recently found in the scrape-off
+layer (SOL) of inner-wall limited (IWL) discharges in tokamaks, is studied
+using 3D, flux-driven, global two-fluid turbulence simulations. The formation
+of the steep plasma profiles measured is found to arise due to radially sheared
+$\vec{E}\times\vec{B}$ poloidal flows. A complex interaction between sheared
+flows and outflowing plasma currents regulates the turbulent saturation,
+determining the transport levels. We quantify the effects of sheared flows,
+obtaining theoretical estimates in agreement with our non-linear simulations.
+Analytical calculations suggest that the IWL $\lambda_q$ is roughly equal to
+the turbulent correlation length.",1606.08564v1
+2016-06-28,Single Spin Asymmetry in Forward $pA$ Collisions,"We compute the transverse single spin asymmetry in light hadron production
+$p^\uparrow p\to hX$ and $p^\uparrow A\to hX$ including the gluon saturation
+effect in the unpolarized nucleon/nucleus. In the forward (large-$x_F$) region,
+the dominant contribution comes from the so-called derivative term associated
+with the soft gluonic pole. This leads to the cancellation of nuclear effects
+in $A_N$ which can be tested at RHIC. We also show that the soft fermionic pole
+disappears in the saturation environment.",1606.08640v2
+2016-07-06,Measurement of forward direct photon production in p-A at the LHC with ALICE - A probe for nuclear PDFs and saturation,"Probes for the small-x parton densities and predicted effects of gluon
+saturation are discussed. At very low x and intermediate Q, only results on
+hadronic observables at the LHC are available, which do not provide unambiguous
+information. It is shown that the measurement of direct photons at forward
+rapidity at the LHC is particularly promising to provide a unique signal. We
+further discuss the possibilities to perform such measurements with a detector
+upgrade in the ALICE experiment and present the R&D activities ongoing.",1607.01673v1
+2016-08-12,Boundary control of cascaded ODE-Heat equations under actuator saturation,"In this paper, we consider boundary stabilization for a cascade of ODE-heat
+system with state delay under actuator saturation. To stabilize the system, we
+design a state feedback controller via the backstepping method and find a bound
+on the domain of attraction. The latter bound is based on Lyapunov method,
+whereas the exponential stability of the delayed cascaded systems is proved by
+using Halanay's inequality. Numerical examples illustrate the efficiency of the
+method.",1608.03729v2
+2016-08-30,Fusion systems over a Sylow $p$-subgroup of $\mathrm{G}_2(p)$,"For $S$ a Sylow $p$-subgroup of the group $\mathrm{G}_2(p)$ for $p$ odd, up
+to isomorphism of fusion systems, we determine all saturated fusion systems
+$\mathcal{F}$ on $S$ with $O_p(\mathcal{F})=1$. For $p \ne 7$, all such fusion
+systems are realized by finite groups whereas for $p=7$ there are $29$
+saturated fusion systems of which $27$ are exotic.",1608.08399v2
+2016-09-19,"Wigner, Husimi and GTMD distributions in the Color Glass Condensate","We study the phase space distributions of gluons inside a nucleon/nucleus in
+the small-$x$ regime including the gluon saturation effect. This can be done by
+using the relation between the gluon Wigner distribution and the dipole
+S-matrix at small-$x$, the latter satisfies the Balitsky-Kovchegov (BK)
+equation. By efficiently solving the BK equation with impact parameter
+dependence, we compute the Wigner, Husimi and generalized TMD (GTMD)
+distributions in the saturation regime. We also investigate the elliptic
+angular dependence of these distributions which has been recently shown to be
+measurable in DIS experiments.",1609.05773v1
+2016-10-16,Non-Hermitian engineering of synthetic saturable absorbers,"We introduce a new type of synthetic saturable absorbers based on quantum
+inspired photonic arrays whose linear light transport characteristics can be
+derived via bosonic algebra. We demonstrate that the interplay between optical
+Kerr nonlinearity, interference effects and non-Hermiticity through radiation
+loss leads to a nonlinear optical filtering response with two distinct regimes
+of small and large optical transmissions. More interestingly, we show that the
+boundary between these two regimes can be very sharp. The threshold optical
+intensity that marks this abrupt ""phase transition"" and its steepness can be
+engineered by varying the number of the guiding elements. The practical
+feasibility of these structures as well as their potential applications in
+laser systems and optical signal processing are also discussed.",1610.04896v1
+2016-10-20,Spatio-temporal extreme events in a laser with a saturable absorber,"We study extreme events occurring in the transverse $(x,y)$ section of the
+field emitted by a broad-area semiconductor laser with a saturable absorber.
+The spatio-temporal events on which we perform the statistical analysis are
+identified as maxima of the field intensity in the 3D space $(x,y,t)$. We
+identify regions in the parameter space where extreme events are more likely to
+occur and we study the connection of those extreme events with the cavity
+solitons that are known to exist in the same system, both stationary and
+self-pulsing.",1610.06452v1
+2016-11-30,Mean Flow Evolution of Saturated Forced Shear Flows in Polytropic Atmospheres,"In stellar interiors shear flows play an important role in many physical
+processes. So far helioseismology provides only large-scale measurements, and
+so the small-scale dynamics remains insufficiently understood. To draw a
+connection between observations and three-dimensional DNS of shear driven
+turbulence, we investigate horizontally averaged profiles of the numerically
+obtained mean state. We focus here on just one of the possible methods that can
+maintain a shear flow, namely the average relaxation method. We show that
+although some systems saturate by restoring linear marginal stability this is
+not a general trend. Finally, we discuss the reason that the results are more
+complex than expected.",1611.10131v1
+2016-12-23,Paving the Way Towards Precision Physics in Saturation Studies Through Exclusive Diffractive Light Neutral Vector Meson Production,"We perform the first next-to-leading order computation of the $\gamma^{(*)}
+\to V$ ($\rho, \phi, \omega$) impact factor in the QCD shockwave approach and
+in the most general kinematics. This paves the way to the very first
+quantitative study of high-energy nucleon and nucleus saturation beyond the
+leading order, in various processes to be measured in $ep$, $eA$, $pp$ and $pA$
+collisions at existing and future colliders.",1612.08026v1
+2017-01-19,Apparent non-conservation of momentum of light due to strongly coupled nonlinear dynamics in a multimode optical fiber,"The intimate interaction between phase-matched parametric amplification and
+strong nonlinear mode coupling in a multimode optical fiber results in a
+saturable spatial mode conversion that appears to violate the conservation of
+momentum. We investigate, by theory and experiment, this new regime of strong
+nonlinear interaction in multimode optical fibers and show that the appearance
+of the non-conservation of linear momentum is merely a clever sleight of hand
+by nature. This novel saturable mode conversion can potentially be used in a
+variety of applications including the generation of exotic quantum states of
+light.",1701.05606v3
+2017-01-20,Effect of nuclear saturation parameters on possible maximum mass of neutron stars,"In order to systematically examine the possible maximum mass of neutron
+stars, which is one of the important properties characterizing the physics in
+high-density region, I construct neutron star models by adopting
+phenomenological equations of state with various values of nuclear saturation
+parameters for low-density region, which are connected to the equation of state
+for high-density region characterized by the possible maximum sound velocity in
+medium. I derive an empirical formula for the possible maximum mass of neutron
+star. If massive neutron stars are observed, it could be possible to get a
+constraint on the possible maximum sound velocity for high-density region.",1701.05646v1
+2017-02-03,Stability and Instability Conditions for Slotted Aloha with Exponential Backoff,"This paper provides stability and instability conditions for slotted Aloha
+under the exponential backoff (EB) model with geometric law $i\mapsto
+b^{-i-i_0}$, when transmission buffers are in saturation, i.e., always full. In
+particular, we prove that for any number of users and for $b>1$ the system is:
+(i) ergodic for $i_0 >1$, (ii) null recurrent for $0<i_0\le 1$, and (iii)
+transient for $i_0=0$. Furthermore, when referring to a system with queues and
+Poisson arrivals, the system is shown to be stable whenever EB in saturation is
+stable with throughput $\lambda_0$ and the system input rate is upper-bounded
+as $\lambda<\lambda_0$.",1702.00991v1
+2017-02-13,Heteroclinic traveling fronts for a generalized Fisher-Burgers equation with saturating diffusion,"We study the existence of monotone heteroclinic traveling waves for a general
+Fisher-Burgers equation with nonlinear and possibly density-dependent
+diffusion. Such a model arises, for instance, in physical phenomena where a
+saturation effect appears for large values of the gradient. We give an estimate
+for the critical speed (namely, the first speed for which a monotone
+heteroclinic traveling wave exists) for some different shapes of the reaction
+term, and we analyze its dependence on a small real parameter when this brakes
+the diffusion, complementing our study with some numerical simulations.",1702.03782v1
+2017-03-01,Extreme points and saturated polynomials,"We consider the problem of characterizing the extreme points of the set of
+analytic functions f on the bidisk with positive real part and f(0)=1. If one
+restricts to those f whose Cayley transform is a rational inner function, one
+gets a more tractable problem. We construct families of such f that are extreme
+points and conjecture that these are all such extreme points. These extreme
+points are constructed from polynomials dubbed saturated, which roughly
+speaking means they have no zeros in the bidisk and as many zeros as possible
+on the boundary without having infinitely many zeros.",1703.00094v1
+2017-03-01,Nonlinear absorption of tetrathiafulvalene radical cation (TTF+) based charge transfer (CT) aggregates in PMMA,"Nolinear Absorption of CT TFF+ aggregates in PMMA matrix was studied with
+resonant excitation around 800 nm in the femtoseconds regime with the Z-Scan
+technique with 100 Hz pulse repetition rate. The saturated absorption profiles
+were fitted with a prepared formula based on steady state rate equations for a
+homogeneous ensemble of two levels systems, thin samples and quasi
+monochromatic field without the usual assumption of low saturation regime. The
+lifetime of the CT state, with the use of this model was estimated in hundred
+of fs, of the same order of magnitude of the exciting pulse.",1703.00388v1
+2017-04-11,Testing a Saturation-Based Theorem Prover: Experiences and Challenges (Extended Version),"This paper attempts to address the question of how best to assure the
+correctness of saturation-based automated theorem provers using our experience
+developing the theorem prover Vampire. We describe the techniques we currently
+employ to ensure that Vampire is correct and use this to motivate future
+challenges that need to be addressed to make this process more straightforward
+and to achieve better correctness guarantees.",1704.03391v1
+2017-05-12,Obtaining the Current-Flux Relations of the Saturated PMSM by Signal Injection,"This paper proposes a method based on signal injection to obtain the
+saturated current-flux relations of a PMSM from locked-rotor experiments. With
+respect to the classical method based on time integration, it has the main
+advantage of being completely independent of the stator resistance; moreover,
+it is less sensitive to voltage biases due to the power inverter, as the
+injected signal may be fairly large.",1705.04605v1
+2017-05-31,Macroscopic random Paschen-Back effect in ultracold atomic gases,"We consider spin- and density-related properties of single-particle states in
+a one-dimensional system with random spin-orbit coupling. We show that the
+presence of an additional Zeeman field $\Delta$ induces both nonlinear spin
+polarization and delocalization of states localized at $\Delta=0$,
+corresponding to a random macroscopic analogue of the Paschen-Back effect.
+While the conventional Paschen-Back effect corresponds to a saturated
+$\Delta-$dependence of the spin polarization, here the gradual suppression of
+the spin-orbit coupling effects by the Zeeman field is responsible both for the
+spin saturation and delocalization of the particles.",1705.11157v1
+2017-06-06,Scaling and Saturation in Infinite-Dimensional Control Problems with Applications to Stochastic Partial Differential Equations,"We establish the dual notions of scaling and saturation from geometric
+control theory in an infinite-dimensional setting. This generalization is
+applied to the low-mode control problem in a number of concrete nonlinear
+partial differential equations. We also develop applications concerning
+associated classes of stochastic partial differential equations (SPDEs). In
+particular, we study the support properties of probability laws corresponding
+to these SPDEs as well as provide applications concerning the ergodic and
+mixing properties of invariant measures for these stochastic systems.",1706.01997v2
+2017-06-20,Saturation of Strong Electron-Electron Umklapp Scattering at High Temperature,"We consider clean metals, at finite temperature, in which the inelastic rate,
+$\hbar/ \tau_{ee}$, can become of the order of, or larger, than the band
+splitting energy. We show that in suchsystems, contrary to the common
+knowledge, the umklapp scattering rate becomes independent of both $\tau_{ee}$
+and the temperature $T,$ in three dimensional systems. We discuss the relation
+of this phenomenon to the saturation of resistivity at high temperature.",1706.06256v2
+2017-07-12,A constrained model for MEMS with varying dielectric properties,"A semilinear parabolic equation with constraint modeling the dynamics of a
+microelectromechanical system (MEMS) is studied. In contrast to the commonly
+used MEMS model, the well-known pull-in phenomenon occurring above a critical
+potential threshold is not accompanied by a breakdown of the model, but is
+recovered by the saturation of the constraint for pulled-in states. It is shown
+that a maximal stationary solution exists and that saturation only occurs for
+large potential values. In addition, the existence, uniqueness, and large time
+behavior of solutions to the evolution equation are studied.",1707.03590v1
+2017-08-09,Electron-electron scattering and conductivity of long multimode channels,"The electron-electron scattering increases the resistance of ballistic
+many-mode channels whose width is smaller than their length. We show that this
+increase saturates in the limit of infinitely long channels. Because the
+mechanisms of angular relaxation of electrons in three and two dimensions are
+different, the saturation value of the correction to the resistance is
+temperature-independent in the case of three-dimensional channels and is
+proportional to the temperature for two-dimensional ones. The spatial behavior
+of electron distribution in the latter case is described by an unusual
+characteristic length.",1708.02770v3
+2017-08-03,NaCl crystal from salt solution with far below saturated concentration under ambient condition,"Under ambient conditions, we directly observed NaCl crystals experimentally
+in the rGO membranes soaked in the salt solution with concentration below and
+far below the saturated concentration. Moreover, in most probability, the NaCl
+crystals show stoichiometries behavior. We attribute this unexpected
+crystallization to the cation-{\pi} interactions between the ions and the
+aromatic rings of the rGO.",1708.02994v1
+2017-08-15,Vicinity effect of massive bodies on YBa2Cu3O6+d being saturated with air components,"We study the influence of the close-lying massive bodies on the YBCO material
+while it is being saturated with air components. It has been found the effect
+that can be interpreted as attraction/repulsion of the bodies to/from the
+samples of hydrated YBCO. This force interaction has been confirmed by a
+""direct"" dynamometric method for the Earth as a maximum massive body to be used
+in our experiments.",1708.07402v3
+2017-09-13,NLO exclusive diffractive processes with saturation,"We present two NLO exclusive impact factors computed in the QCD shock wave
+approach. These are the very first steps towards precision studies of a wide
+range of high energy exclusive processes with saturation effects in $ep$, $eA$,
+$pp$ and $pA$ collisions.",1709.04422v1
+2017-10-27,The saturation bifurcation in coupled oscillators,"We examine examples of weakly nonlinear systems whose steady states undergo a
+bifurcation with increasing forcing, such that a forced subsystem abruptly
+ceases to absorb additional energy, instead diverting it into an initially
+quiescent, unforced subsystem. We derive and numerically verify analytical
+predictions for the existence and behavior of such saturated states for a class
+of oscillator pairs. We also examine related phenomena, including
+zero-frequency response to periodic forcing, Hopf bifurcations to
+quasiperiodicity, and bifurcations to periodic behavior with multiple
+frequencies.",1710.10317v3
+2017-11-16,Vector Representation of Preferences on $σ$-Algebras and Fair Division in Saturated Measure Spaces,"The purpose of this paper is twofold. First, we axiomatize preference
+relations on a $\sigma$-algebra of a saturated measure space represented by a
+vector measure and furnish a utility representation in terms of a nonadditive
+measure satisfying the appropriate requirement of continuity and convexity.
+Second, we investigate the fair division problems in which each individual has
+nonadditive preferences on a $\sigma$-algebra invoking our utility
+representation result. We show the existence of individually rational Pareto
+optimal partitions, Walrasian equilibria, core partitions, and Pareto optimal
+envy-free partitions.",1711.05973v2
+2017-11-19,Dynamic cavity effect in Topological Insulator Bi2Te3 based Passive Q-switched Solid State Laser,"Dynamic cavity effect of a Topological Insulator Bi2Te3 based Passive
+Q-switched (QS) solid state laser was investigated. With a saturation intensity
+as low as a few kW, Bi2Te3 processed by hydrothermal exfoliation serves a
+sensitive saturable absorber to initiate Q-switching. Without material damage,
+a transition from QS state to CW state was observed when the pumping strength
+increases which was explained by the modulation instability spectrum of laser
+rate equation.",1711.06994v1
+2017-11-21,Presentations of Cluster Modular Groups and Generation by Cluster Dehn Twists,"We give a method to compute presentations of saturated cluster modular
+groups. Using this, we obtain finite presentations of the saturated cluster
+modular groups of finite mutation type $X_6$ and $X_7$. We verify that the
+cluster modular groups of finite mutation type $\widetilde{E}_6$,
+$\widetilde{E}_7$, $\widetilde{E}_8$, $G_2^{(*,*)}$, $X_6$ and $X_7$ are
+virtually generated by cluster Dehn twists.",1711.07785v5
+2017-12-05,"Multiparton interactions, small-x processes and diffraction","The connection between multiparton interaction, diffractive processes and
+saturation effects is discussed. The relation of the rise of the gluon density
+at small longitudinal momentum fractions x with the occurrence of saturation,
+diffraction and multiparton interaction is being studied both experimentally
+and theoretically. We illustrate key ideas underlying recent progress, and
+stress the role of different theoretical approaches to small-x QCD evolution in
+investigations of multiparton interactions.",1712.01726v2
+2017-12-07,Systematics of strong nuclear amplification of gluon saturation from exclusive vector meson production in high energy electron-nucleus collisions,"We show that gluon saturation gives rise to a strong modification of the
+scaling in both the nuclear mass number $A$ and the virtuality $Q^2$ of the
+vector meson production cross-section in exclusive deep-inelastic scattering
+off nuclei. We present qualitative analytic expressions for how the scaling
+exponents are modified as well as quantitative predictions that can be tested
+at an Electron-Ion Collider.",1712.02508v2
+2017-12-14,"Global properties of an age-structured virus model with saturated antibody immune response, multi-target cells and general incidence rate","Some viruses, such as human immunodeficiency virus, can infect several types
+of cell populations. The age of infection can also affect the dynamics of
+infected cells and production of viral particles. In this work, we study a
+virus model with infection-age and different types of target cells which takes
+into account the saturation effect in antibody immune response and a general
+non-linear infection rate. We construct suitable Lyapunov functionals to show
+that the global dynamics of the model is completely determined by two critical
+values: the basic reproduction number of virus and the reproductive number of
+antibody response.",1712.05064v1
+2018-03-15,Hypergraph Saturation Irregularities,"Let $\mathcal{F}$ be a family of $r$-graphs. An $r$-graph $G$ is called
+$\mathcal{F}$-saturated if it does not contain any members of $\mathcal{F}$ but
+adding any edge creates a copy of some $r$-graph in $\mathcal{F}$. The
+saturation number $\operatorname{sat}(\mathcal{F},n)$ is the minimum number of
+edges in an $\mathcal{F}$-saturated graph on $n$ vertices. We prove that there
+exists a finite family $\mathcal{F}$ such that
+$\operatorname{sat}(\mathcal{F},n) / n^{r-1}$ does not tend to a limit. This
+settles a question of Pikhurko.",1803.05799v1
+2018-04-24,On $p$-robust saturation on quadrangulations,"For the Poisson problem in two dimensions, posed on a domain partitioned into
+axis-aligned rectangles with up to one hanging node per edge, we envision an
+efficient error reduction step in an instance-optimal $hp$-adaptive finite
+element method. Central to this is the problem: Which increase in local
+polynomial degree ensures $p$-robust contraction of the error in energy norm?
+We reduce this problem to a small number of saturation problems on the
+reference square, and provide strong numerical evidence for their solution.",1804.09065v1
+2018-05-02,"Universal correlations in the nuclear symmetry energy, slope parameter, and curvature","From general Fermi liquid theory arguments, we derive correlations among the
+symmetry energy (J), its slope parameter (L), and curvature (K_sym) at nuclear
+matter saturation density. We argue that certain properties of these
+correlations do not depend on details of the nuclear forces used in the
+calculation. We derive as well a global parametrization of the density
+dependence of the symmetry energy that we show is more reliable, especially at
+low densities, than the usual Taylor series expansion around saturation
+density. We then benchmark these predictions against explicit results from
+chiral effective field theory.",1805.01000v1
+2018-05-29,How it cramps the flow: three regimes for the saturation of parallel ion-beam instabilities,"Motivated by recent advances in laboratory experiments on parallel ion-beam
+instabilities, we present a theoretical framework for and simulations of their
+evolution towards shock formation and Fermi acceleration. After reviewing the
+theory of beam instabilities with a focus on the so-called nonresonant or Bell
+instability, which we show to be due to the gyromotion of background ions, we
+contrast the saturation of three parameter regimes: (I) the left-handed
+""nonresonant"" regime, (II) the right-handed beam-gyroresonant regime, (III) the
+balanced, mixed-turbulence regime.",1805.11220v1
+2018-06-08,The Saturated Subpaths Decomposition in Z 2 : a short note on generalized Tangential Cover,"In this short note, we generalized the Tangential Cover used in Digital
+Geometry in order to use very general geometric predicates. We present the
+required notions of saturated $\alpha$-paths of a digital curve as well as
+conservative predicates which indeed cover nearly all geometric digital
+primitives published so far. The goal of this note is to prove that under a
+very general situation, the size of the Tangential Cover is linear with the
+number of points of the input curve. The computation complexity of the
+Tangential Cover depends on the complexity of incremental recognition of
+geometric predicates. Moreover, in the discussion, we show that our approach
+does not rely on connectivity of points as it might be though first.",1806.03053v1
+2018-06-25,Finding models through graph saturation,"We give a procedure that can be used to automatically satisfy invariants of a
+certain shape. These invariants may be written with the operations
+intersection, composition and converse over binary relations, and equality over
+these operations. We call these invariants \tr{}s that we interpret over
+graphs. For questions stated through sets of these sentences, this paper gives
+a semi-decision procedure we call graph saturation. It decides entailment over
+these \tr{}s, inspired on graph rewriting. We prove correctness of the
+procedure. Moreover, we show the corresponding decision problem to be
+undecidable. This confirms a conjecture previously stated by the author.",1806.09392v1
+2018-07-09,Multiplicity of the saturated special fiber ring of height two perfect ideals,"Let $R$ be a polynomial ring and $I \subset R$ be a perfect ideal of height
+two minimally generated by forms of the same degree. We provide a formula for
+the multiplicity of the saturated special fiber ring of $I$. Interestingly,
+this formula is equal to an elementary symmetric polynomial in terms of the
+degrees of the syzygies of $I$. Applying ideas introduced in arXiv:1805.05180,
+we obtain the value of the j-multiplicity of $I$ and an effective method for
+determining the degree and birationality of rational maps defined by
+homogeneous generators of $I$.",1807.03189v2
+2018-08-07,Full-wave analysis of reverse saturable absorption in time-domain,"An advanced full-wave time-domain numerical model for reverse saturable
+absorption (RSA) is presented and verified against established methods. Rate
+equations, describing atomic relaxations and excitation dynamics, are coupled
+to Maxwell equations by using a Lorentzian oscillator. These oscillator models
+the kinetics-dependent light-matter interaction in the form of averaged
+polarizations. The coupled equations are discretized in space and time using a
+finite-difference time-domain method which provides a versatile platform to
+design complex structures and integrate diverse material models. We believe
+that our models are crucial tools enabling for the realization and optimization
+of optical limiting and all-optical switching systems.",1808.02436v1
+2018-12-10,Collective dynamics of evanescently coupled excitable lasers with saturable absorber,"We present a numerical study of the collective dynamics in a population of
+coupled excitable lasers with saturable absorber. At variance with previous
+studies where real-valued (lossy) coupling was considered, we focus here on the
+purely imaginary coupling (evanescent wave coupling). We show that evanescently
+coupled excitable lasers synchronize in a more efficient way compared to the
+lossy coupled ones. Furthermore we show that out-of-diagonal disorder-induced
+localization of excitability takes place for imaginary coupling too, but it can
+be frustrated by nonvanishing linewidth enhancement factor.",1812.03691v1
+2018-12-19,Saturated control without velocity measurements for planar robots with flexible joints,"In this work, we propose a passivity-based controller that addresses the
+problem of set point regulation for planar robots with two links and flexible
+joints. Moreover, the controller is saturated and does not require velocity
+measurements. Additionally, we present experiments that corroborate the
+theoretical results of this note.",1812.08257v2
+2019-03-04,Broadening and saturation effects in dijet azimuthal correlations in p-p and p-Pb collisions at $\mathbf{\sqrt{s_{NN}}} = $ 5.02 TeV,"We demonstrate that the recent forward-forward dijet correlation data
+measured by the ATLAS collaboration for proton-proton and proton-lead
+collisions are consistent with the broadening effects due to both the gluon
+saturation and the resummation of large logarithms of the hard scale (the
+so-called Sudakov logarithms). We find that both effects are necessary to
+describe the experimental results.",1903.01361v3
+2019-04-01,Multi-outcome homodyne detection in a coherent-state light interferometer,"The Cram\'{e}r-Rao bound plays a central role in both classical and quantum
+parameter estimation, but finding the observable and the resulting inversion
+estimator that saturates this bound remains an open issue for general
+multi-outcome measurements. Here we consider multi-outcome homodyne detection
+in a coherent-light Mach-Zehnder interferometer and construct a family of
+inversion estimators that almost saturate the Cram\'{e}r-Rao bound over the
+whole range of phase interval. This provides a clue on constructing optimal
+inversion estimators for phase estimation and other parameter estimation in any
+multi-outcome measurement.",1904.00557v1
+2019-04-16,Equilibria in a large production economy with an infinite dimensional commodity space and price dependent preferences,"We prove the existence of a competitive equilibrium in a production economy
+with infinitely many commodities and a measure space of agents whose
+preferences are price dependent. We employ a saturated measure space for the
+set of agents and apply recent results for an infinite dimensional separable
+Banach space such as Lyapunov's convexity theorem and an exact Fatou's lemma to
+obtain the result.",1904.07444v2
+2019-04-16,Loss and Saturation in Superconducting Travelling-Wave Parametric Amplifiers,"We have developed a coupled-mode analysis framework for superconducting
+travelling-wave parametric amplifiers using the full Telegrapher's equations to
+incorporate loss-related behaviour. Our model provides an explanation of
+previous experimental observations regarding loss in amplifiers, advantages of
+concatenating amplifiers to achieve high gains, and signal gain saturation.
+This work can be used to guide the design of amplifiers in terms of the choice
+of material systems, transmission line geometry, operating conditions, and pump
+strength.",1904.07673v1
+2019-04-20,Converse estimates for the simultaneous approximation by Bernstein polynomials with integer coefficients,"We prove a weak converse estimate for the simultaneous approximation by
+several forms of the Bernstein polynomials with integer coefficients. It is
+stated in terms of moduli of smoothness. In particular, it yields a big
+$O$-characterization of the rate of that approximation. We also show that the
+approximation process generated by these Bernstein polynomials with integer
+coefficients is saturated. We identify its saturation rate and the trivial
+class.",1904.09417v2
+2019-06-03,Nonlinear Absorption and Photocurrent in Weyl Semimetals,"Theory of light absorption and circular photocurrent in Weyl semimetals is
+developed for arbitrary large light intensities with account for both elastic
+and inelastic relaxation processes of Weyl fermions. The direct optical
+transition rate is shown to saturate at large intensity, and the saturation
+behaviour depends on the light polarization and on the ratio of the elastic and
+inelastic relaxation times. The linear-circular dichroism in absorption is
+shown to exceed 10~\% at intermediate light wave amplitudes and fast energy
+relaxation. At large intensity $I$, the light absorption coefficient drops as
+$1/\sqrt{I}$, and the circular photogalvanic current increases as $\sqrt{I}$.",1906.00686v1
+2019-06-04,Controllable pulse patterns in fiber lasers,"An all-optical pulse power editing (PPE) technique is reported. Using the PPE
+technique, pulses with different peak powers are output and directed to the
+positive or reverse saturable absorption (SA) range of the saturable absorber.
+Further, under the combined action of the PPE technique and SA, four pulse
+patterns including dissipative soliton (DS), DS molecules, soliton compounds
+composed of DS and noise-like pulse (NLP), and pure NLP are controllably
+generated in fiber lasers. The results are conducive for developing advanced DS
+lasers and can further clarify the onset of pulse dynamic patterns.",1906.01555v2
+2019-06-21,Stationary quantum BGK model for bosons and fermions in a bounded interval,"In this paper, we consider the existence problem for a stationary
+relaxational models of the quantum Boltzmann equation. More precisely, we
+establish the existence of mild solution to the fermionic or bosonic quantum
+BGK model in a slab with inflow boundary data. Unlike the classical case, it is
+necessary to verify that the quantum local equilibrium state is well-defined,
+and the transition from the non-condensed state to the condensated state
+(Bosons), or from the non-saturated state to the saturated state (Fermions)
+does not arise in our solution space.",1906.08961v1
+2019-07-15,The saturation assumption yields optimal convergence of two-level adaptive BEM,"We consider the convergence of adaptive BEM for weakly-singular and
+hypersingular integral equations associated with the Laplacian and the
+Helmholtz operator in 2D and 3D. The local mesh-refinement is driven by some
+two-level error estimator. We show that the adaptive algorithm drives the
+underlying error estimates to zero. Moreover, we prove that the saturation
+assumption already implies linear convergence of the error with optimal
+algebraic rates.",1907.06612v1
+2019-07-26,The Continuous Spontaneous Localization Layering Effect from a Lattice Perspective,"For a solid lattice, we rederive the Continuous Spontaneous Localization
+(CSL) noise total energy gain of a test mass starting from a Lindblad
+formulation, and from a similar starting point rederive the geometry factor
+governing center of mass energy gain. We then suggest that the geometry factor
+can be used as a way to distinguish between low temperature cantilever motion
+saturation arising from CSL noise, and saturation arising from thermal leakage.",1907.11598v4
+2019-08-09,The general Nature of Saturated Designs,"We contemplate an experimental situation in a $2^k$-factorial experiment with
+acute resource crunch so that we need to conduct just a saturated design [SD] -
+with the understanding that precision of the estimates cannot be estimated from
+the data. It is known beforehand which effect(s)/interaction(s) are likely to
+be negligible. We examine the flexibility to the extent that an experimenter
+can make a choice of an SD in order to retain information on all the remaining
+[non-negligible] effects/interactions.",1908.03317v2
+2019-08-30,Vanishing diffusion limits for planar fronts in bistable models with saturation,"We deal with heteroclinic planar fronts for parameter-dependent
+reaction-diffusion equations with bistable reaction and saturating diffusive
+term like $$ u_t=\epsilon \, \textrm{div}\, \left(\frac{\nabla u}{\sqrt{1+\vert
+\nabla u \vert^2}}\right) + f(u), \quad u=u(x, t), \; x \in \textbf{R}^n, \, t
+\in \textbf{R}, $$ analyzing in particular their behavior for $\epsilon \to 0$.
+First, we construct monotone and non-monotone planar traveling waves, using a
+change of variables allowing to analyze a two-point problem for a suitable
+first-order reduction; then, we investigate their asymptotic behavior for
+$\epsilon \to 0$, showing in particular that the convergence of the critical
+fronts to a suitable step function may occur passing through discontinuous
+solutions.",1908.11651v1
+2019-09-14,Fusion systems of blocks of finite groups over arbitrary fields,"To any block idempotent $b$ of a group algebra $kG$ of a finite group $G$
+over a field $k$ of characteristic $p>0$, Puig associated a fusion system and
+proved that it is saturated if the $k$-algebra $kC_G(P)e$ is split, where
+$(P,e)$ is a maximal $kGb$-Brauer pair. We investigate in the non-split case
+how far the fusion system is from being saturated by describing it in an
+explicit way as being generated by the fusion system of a related block
+idempotent over a larger field together with a single automorphism of the
+defect group.",1909.06666v1
+2019-09-15,Destroying Saturation while Preserving Presaturation at an Inaccessible; an Iterated Forcing Argument,"We prove that a large class of presaturated ideals at inaccessible cardinals
+can be de-saturated while preserving their presaturation, answering both a
+question of Foreman and of Cox and Eskew. We do so by iterating a generalized
+version of Baumgartner and Taylor's forcing to add a club with finite
+conditions along an inaccessible cardinal, and invoking Foreman's Duality
+Theorem.",1909.06704v4
+2019-10-29,Saturation and forward jets in proton-lead collisions at the LHC,"We investigate the forward-jet energy spectrum within the Color Glass
+Condensate framework at 5 TeV center-of-mass energy. In particular, we focus on
+the kinematic range covered by the CMS-CASTOR calorimeter. We show that our
+saturation-model calculations are compatible with the CASTOR measurements and
+that to optimally reproduce the data, effects of multi-parton interactions need
+to be included. We predict a significant nuclear suppression - reaching down to
+50% at the lowest considered jet energies $E_{\rm jet} \sim 500 \, {\rm GeV}$.",1910.13116v1
+2019-11-29,Bistability in a SIRS model with general nonmonotone and saturated incidence rate,"In this paper, we consider a SIRS model with general nonmonotone and
+saturated incidence rate and perform stability and bifurcation analysis. We
+show that the system has saddle-node bifurcation and displays bistable
+behavior. We obtain the critical thresholds that characterize the dynamical
+behaviors of the model. We find with surprise that the system always admits a
+disease free equilibrium E0 which is always asymptotically stable. Numerical
+simulations are carried out to verify our results.",1911.13002v1
+2019-12-13,Lamb-dips and Lamb-peaks in the saturation spectrum of HD,"The saturation spectrum of the R(1) transition in the (2-0) band in HD is
+found to exhibit a composite line shape, involving a Lamb-dip and a Lamb-peak.
+We propose an explanation for such behavior based on the effects of cross-over
+resonances in the hyperfine substructure, which is made quantitative in a
+density-matrix calculation. This resolves an outstanding discrepancy on the
+rovibrational R(1) transition frequency, which is now determined at 217 105 181
+901 (50) kHz and in agreement with current theoretical calculations.",1912.06406v1
+2019-12-13,An efficient numerical scheme for fully coupled flow and reactive transport in variably saturated porous media including dynamic capillary effects,"In this paper, we study a model for the transport of an external component,
+e.g., a surfactant, in variably saturated porous media. We discretize the model
+in time and space by combining a backward Euler method with the linear Galerkin
+finite elements. The Newton method and the L-Scheme are employed for the
+linearization and the performance of these schemes is studied numerically. A
+special focus is set on the effects of dynamic capillarity on the transport
+equation.",1912.06731v2
+2020-01-24,Convergence of a finite element method for degenerate two-phase flow in porous media,"A finite element method with mass-lumping and flux upwinding, is formulated
+for solving the immiscible two-phase flow problem in porous media. The method
+approximates directly the wetting phase pressure and saturation, which are the
+primary unknowns. The discrete saturation satisfies a maximum principle.
+Theoretical convergence is proved via a compactness argument. The proof is
+convoluted because of the degeneracy of the phase mobilities and the
+unboundedness of the capillary pressure.",2001.08859v1
+2020-01-20,Variational inequalities for ferroelectric constitutive modeling,"This paper is concerned with modeling the polarization process in
+ferroelectric media. We develop a thermodynamically consistent model, based on
+phenomenological descriptions of free energy as well as switching and
+saturation conditions in form of inequalities. Thermodynamically consistent
+models naturally lead to variational formulations. We propose to use the
+concept of variational inequalities. We aim at combining the different
+phenomenological conditions into one variational inequality. In our formulation
+we use one Lagrange multiplier for each condition (the onset of domain
+switching and saturation), each satisfying Karush-Kuhn-Tucker conditions. An
+update for reversible and remanent quantities is then computed within one, in
+general nonlinear, iteration.",2001.11475v2
+2020-02-13,Dynamics Landscape for Acoustic Superradiance,"We analyze the behaviour of acoustic vortex beams interacting with rotating,
+fluid-saturated porous materials. Regions of the parameter space that exhibit
+distinct dynamical features are identified, with a focus on features that are
+relevant to the characterization of rotational superradiance. We discuss the
+similarities and differences between two recent proposals to observe acoustic
+superradiance with rotating, air-saturated sound absorbers. Finally,
+theoretical predictions for macroscopic acoustic scattering, obtained by
+averaging over interactions between the fluid and the porous material at the
+microscopic level, are compared with predictions of the first-Born
+approximation.",2002.05605v2
+2020-03-21,Exposing Hidden Alternative Conformations of Small Flexible Molecules in 2D NMR Spectroscopy Using 1H-15N HMBC,"Two-dimensional 1H-15N HMBC NMR spectra of a well-known
+anticonvulsant-carbamazepine-dissolved in chloroform, recorded on an NMR
+spectrometer and obtained from quantum-chemical calculations prove the
+existence of hidden conformers in saturated solutions. A weaker influence of
+ring currents was revealed for the hidden conformation of carbamazepine
+dissolved in saturated solution, which provides a simple approach for
+discovering hidden conformations. Hidden conformers were found in three
+different solvents: dimethyl sulfoxide, chloroform, and dichloromethane.",2003.09608v2
+2020-06-13,Saturating the Data Processing Inequality for $α-z$ Renyi Relative Entropy,"It has been shown that the $\alpha-z$ R{\'e}nyi relative entropy satisfies
+the Data Processing Inequality (DPI) for a certain range of $\alpha$'s and
+$z$'s. Moreover, the range is completely characterized by Zhang in `20. We
+prove necessary and algebraically sufficient conditions to saturate the DPI for
+the $\alpha-z$ R{\'e}nyi relative entropy whenever $1<\alpha\leq 2$ and
+$\frac{\alpha}{2}\leq z\leq\alpha$. Moreover, these conditions coincide
+whenever $\alpha=z$.",2006.07726v2
+2020-06-19,Lipschitz fractions of a complex analytic algebra and Zariski saturation,"This text is the English translation, due to Naoufal Bouchareb, of an
+unpublished manuscript of 1969 (the French version is available on HAL as
+hal-00384928) inspired by Zariski's theory of saturation. Its publication is
+justified by the fact that it appears now as a precursor of the recently
+developed study of the Lipschitz geometry (for the outer metric) of germs of
+complex analytic spaces. This version contains some new footnotes and an
+additional bibliography.",2006.10982v1
+2020-06-23,Achieving Performance and Safety in Large Scale Systems with Saturation using a Nonlinear System Level Synthesis Approach,"We present a novel class of nonlinear controllers that interpolates among
+differently behaving linear controllers as a case study for recently proposed
+Linear and Nonlinear System Level Synthesis framework. The structure of the
+nonlinear controller allows for simultaneously satisfying performance and
+safety objectives defined for small- and large-disturbance regimes. The
+proposed controller is distributed, handles delays, sparse actuation, and
+localizes disturbances. We show our nonlinear controller always outperforms its
+linear counterpart for constrained LQR problems. We further demonstrate the
+anti-windup property of an augmented control strategy based on the proposed
+controller for saturated systems via simulation.",2006.12766v1
+2020-06-23,Analysis of Methanol Maser Flares in G107.298+5.63 andS255-NIRS3,"A 3D maser model has been used to perform an inverse problem on the light
+curves from three high-amplitude maser flares, selected on the basis of
+contemporaneous infra-red observations. Plots derived from the model recover
+the size of the maser cloud, and two parameters linked to saturation, from
+three observational properties of the light curve. Recovered sizes are
+consistent with independent interferometric measurements. Maser objects
+transition between weak and moderate saturation during a flare.",2006.13124v1
+2020-08-03,Nonlinearity continuation method for steady-state groundwater flow modeling in variably saturated conditions,"Application of nonlinearity continuation method to numerical solution of
+steady-state groundwater flow in variably saturated conditions is presented. In
+order to solve the system of nonlinear equations obtained by finite volume
+discretization of steady-state Richards equation, a series of problems with
+increasing nonlinearity are solved using the Newton method. This approach is
+compared to pseudo-transient method on several test cases, including real site
+problems and involving parallel computations.",2008.00730v1
+2020-08-13,On the topological entropy of saturated sets for amenable group actions,"Let $(X,\rho,G)$ be a $G-$action topological system, where $G$ is a countable
+infinite discrete amenable group and $X$ a compact metric space. We prove a
+variational principle for topological entropy of saturated sets for systems
+which have specification and uniform separation properties. As an application,
+we compute the topological entropy of level sets and irregular sets.",2008.05843v3
+2020-11-11,Saturating stable matchings,"I relate bipartite graph matchings to stable matchings. I prove a necessary
+and sufficient condition for the existence of a saturating stable matching,
+where every agent on one side is matched, for all possible preferences. I
+extend my analysis to perfect stable matchings, where every agent on both sides
+is matched.",2011.06046v2
+2020-11-25,The Poisson saturation of coregular submanifolds,"This paper is devoted to coregular submanifolds in Poisson geometry. We show
+that their local Poisson saturation is an embedded Poisson submanifold, and we
+give a normal form for this Poisson submanifold around the coregular
+submanifold. This result recovers the normal form around Poisson transversals,
+and it yields Poisson versions of some normal form/rigidity results around
+constant rank submanifolds in symplectic geometry. As an application, we prove
+a uniqueness result concerning coisotropic embeddings of Dirac manifolds in
+Poisson manifolds. We also show how our results generalize to the setting of
+coregular submanifolds in Dirac geometry.",2011.12650v2
+2020-12-04,Reviewing the role of the extinction coefficient in radar remote sensing,"This report revisits the role of the extinction coefficient in radar
+backscattering-based models for forest monitoring. A review of a number of
+works dealing with this issue has revealed a diversity of extinction values
+being unclear its dependence on the sensor frequency and the forest type. In
+addition, a backscattering model directly derived from the RVoG formulation is
+employed to analyse the saturation of backscattering level as a function of
+vegetation height and the presence of a decreasing trend of backscatter beyond
+the saturation point as suggested in previous works in the literature.
+According to this analysis it seems reasonable to think that further research
+specially focused on dedicated experimental measurements of the extinction
+coefficient should be carried out.",2012.02609v1
+2021-01-13,Nonlinear saturation of thermal instabilities,"Low-frequency simulations of a one-layer model with lateral buoyancy
+variations (i.e., thermodynamically active) have revealed circulatory motions
+resembling quite closely submesoscale observations in the surface ocean rather
+than indefinitely growing in the absence of a high-wavenumber instability
+cutoff. In this note it is shown that the existence of a convex
+pseudoenergy--momentum integral of motion for the inviscid, unforced dynamics
+provides a mechanism for the nonlinear saturation of such thermal instabilities
+in the zonally symmetric case. The result is an application of
+\citet{Arnold-66} and \citet{Shepherd-88a} methods.",2101.05375v2
+2020-11-26,Positive Solutions of Competition Model with Saturation,"In this paper, the positive solutions of a diffusive competition model with
+saturation are mainly discussed. Under certain conditions, the stability and
+multiplicities of coexistence states are analyzed. And by using the topological
+degree theory in cones, it is proved that the problem has at least two positive
+solutions under certain conditions. Finally, investigating the bifurcation of
+coexistence states emanating from the semi-trivial solutions, some instability
+and multiplicity results of coexistence state are expressed.",2101.06231v1
+2021-02-13,Parameter Dependence and Bell nonlocality,"Bell's theorem asserts that no model that satisfies all of the plausible
+physical assumptions of outcome independence (OI), measurement independence
+(MI) and Parameter Independence (PI) can reproduce quantum mechanics. Here I
+find the optimum model that saturates CHSH inequality for the case that outcome
+independence and measurement independence hold but parameter dependence is
+allowed. I find the bound as a function of a measure of parameter dependence
+and show that the model proposed by [New Journal of Physics,12(8):083051] is
+optimal for one-way parameter dependence. The symbolic optimizations to find
+the saturating models are performed using the open source software Analytical
+Optimizer v1.0.",2102.06920v2
+2021-02-15,Metatheory.jl: Fast and Elegant Algebraic Computation in Julia with Extensible Equality Saturation,"We introduce Metatheory.jl: a lightweight and performant general purpose
+symbolics and metaprogramming framework meant to simplify the act of writing
+complex Julia metaprograms and to significantly enhance Julia with a native
+term rewriting system, based on state-of-the-art equality saturation
+techniques, and a dynamic first class Abstract Syntax Tree (AST) pattern
+matching system that is dynamically composable in an algebraic fashion, taking
+full advantage of the language's powerful reflection capabilities. Our
+contribution allows to perform general purpose symbolic mathematics,
+manipulation, optimization, synthesis or analysis of syntactically valid Julia
+expressions with a clean and concise programming interface, both during
+compilation or execution of programs.",2102.07888v1
+2021-03-05,Nuclear binding energy in holographic QCD,"Saturation of the nuclear binding energy is one of the most important
+properties of atomic nuclei. We derive the saturation in holographic QCD, by
+building a shell-model-like mean-field nuclear potential from the nuclear
+density profile obtained in a holographic multi-baryon effective theory. The
+numerically estimated binding energy is close to the experimental value.",2103.03563v3
+2021-03-20,Influence of nonlinear- and saturable-absorption on laser lift-off threshold of oxide/metal structure,"In this work, a new model of effective lift-off threshold of oxide/metal
+target is presented. The influence of nonlinear processes in the oxide layer on
+its removal from the metallic samples using picosecond laser was investigated.
+Nonlinear and saturable absorption in the layer was incorporated into modeling
+for prediction of effective laser lift-off threshold fluence change with
+varying peak intensities in z-scan type experiment for the first time. The new
+model coincides well with the experimental results.",2103.11140v2
+2021-06-09,"On a convexity property of tensor products of irreducible, rational representations of $SL(n)$","The aim of this note is to point out a convexity property with respect to the
+root lattice for the support of the highest weights that occur in a tensor
+product of irreducible rational representations of $SL(n)$ over the complex
+numbers. The observation is a consequence of the convexity properties of the
+saturation cone and the validity of the saturation conjecture for $SL(n)$.",2106.05028v2
+2021-06-17,"Equivalence of cubical and simplicial approaches to $(\infty,n)$-categories","We prove that the marked triangulation functor from the category of marked
+cubical sets equipped with a model structure for ($n$-trivial, saturated)
+comical sets to the category of marked simplicial set equipped with a model
+structure for ($n$-trivial, saturated) complicial sets is a Quillen
+equivalence. Our proof is based on the theory of cones, previously developed by
+the first two authors together with Lindsey and Sattler.",2106.09428v3
+2021-06-17,Relating entropies of quantum channels,"In this work, we study two different approaches to defining the entropy of a
+quantum channel. One of these is based on the von Neumann entropy of the
+corresponding Choi-Jamio{\l}kowski state. The second one is based on the
+relative entropy of the output of the extended channel relative to the output
+of the extended completely depolarizing channel. This entropy then needs to be
+optimized over all possible input states. Our results first show that the
+former entropy provides an upper bound on the latter. Next, we show that for
+unital qubit channels, this bound is saturated. Finally, we conjecture and
+provide numerical intuitions that the bound can also be saturated for random
+channels as their dimension tends to infinity.",2106.09629v1
+2021-07-07,Newell-Littlewood numbers III: eigencones and GIT-semigroups,"The Newell-Littlewood numbers are tensor product multiplicities of Weyl
+modules for the classical groups in the stable range. Littlewood-Richardson
+coefficients form a special case. Klyachko connected eigenvalues of sums of
+Hermitian matrices to the saturated LR-cone and established defining linear
+inequalities. We prove analogues for the saturated NL-cone: an eigenvalue
+interpretation; a minimal list of defining linear inequalities; a description
+by Extended Horn inequalities, as conjectured in part II of this series; and a
+factorization of NL-numbers, on the boundary.",2107.03152v2
+2021-08-25,Fell bundles over a countable discrete group and strong Morita equivalence for inclusions of $C^*$-algebras,"We consider two saturated Fell bundles over a countable discrete group, whose
+unit fibers are $\sigma$-unital $C^*$-algebras. Then by taking the reduced
+cross-sectional $C^*$-algebras, we get two inclusions of $C^*$-algebras. We
+suppose that they are strongly Morita equivalent as inclusions of
+$C^*$-algebras. Also, we suppose that one of the inclusions of $C^*$-algebras
+is irreducible, that is, the relative commutant of one of the unit fiber
+algebras, which is a $\sigma$-unital $C^*$-algebra, in the multiplier
+$C^*$-algebra of the reduced cross-sectional $C^*$-algebra is trivial. We show
+that the two saturated Fell bundles are then equivalent up to some automorphism
+of the group.",2108.11013v1
+2021-09-21,Double Schubert polynomials do have saturated Newton polytopes,"We prove that double Schubert polynomials have the Saturated Newton Polytope
+property. This settles a conjecture by Monical, Tokcan and Yong. Our ideas are
+motivated by the theory of multidegrees. We introduce a notion of
+standardization of ideals that enables us to study non-standard multigradings.
+This allows us to show that the support of the multidegree polynomial of each
+Cohen-Macaulay prime ideal, and in particular, that of each Schubert
+determinantal ideal is a discrete polymatroid.",2109.10299v3
+2021-09-22,Kernels of Localities,"We state a sufficient condition for a fusion system to be saturated. This is
+then used to investigate localities with kernels, i.e. localities which are (in
+a particular way) extensions of groups by localities. As an application of
+these results, we define and study certain products in fusion systems and
+localities, thus giving a new method to construct saturated subsystems of
+fusion systems.",2109.10962v2
+2021-11-02,Saturated feedback stabilizability to trajectories for the Schlögl parabolic equation,"It is shown that there exist a finite number of indicator functions, which
+allow us to track an arbitrary given trajectory of the Schl\""ogl model, by
+means of an explicit saturated feedback control input whose magnitude is
+bounded by a constant independent of the given targeted trajectory. Simulations
+are presented showing the stabilizing performance of the explicit feedback
+constrained control. Further, such performance is compared to that of a
+receding horizon constrained control minimizing the classical energy cost
+functional.",2111.01329v1
+2021-11-11,Phase Transitions in the Classical Simulability of Open Quantum Systems,"We study the evolution of an open quantum system using a Langevin unravelling
+of the density matrix evolution over matrix product states. As the strength of
+coupling to and temperature of the environment is increased, we find a
+transition where the entanglement of the individual trajectories saturates,
+permitting a classical simulation of the system for all times. This is the
+Hamiltonian open system counterpart of the saturation in entanglement found in
+random circuits with projective or weak measurements. If a system is open,
+there is a limit to the advantage in simulating its behaviour on a quantum
+computer, even when that evolution harbours important quantum effects.",2111.06408v1
+2021-12-23,Deterministic generation of a perfect soliton crystal with a saturable absorber,"We numerically investigate the deterministic generation of a perfect soliton
+crystal (PSC) in an optical microresonator functionalized with a saturable
+absorber (SA). The SA allows the direct formation of a PSC from an initial,
+periodic Turing roll. It prevents passage through a chaotic state, which
+induces a stochastic nature as regards the number of generated dissipative Kerr
+solitons. We show that PSCs form deterministically, and the number is
+controlled by adjusting the input power and SA parameter. Our work provides a
+simple approach for obtaining a stable PSC that offers an ultra-high repetition
+rate and a high comb output power.",2112.12336v1
+2022-01-02,Energy evolution of the overlap functions: increasing ratio of $σ_{el}(s)/σ_{tot}(s)$ and black ring emergence,"We analyse the two possible options of the energy dependency of the elastic
+and inelastic overlap functions. These correspond to saturation of the black
+disk limit (BEL effect) and to the unitarity saturation (REL effect) at
+$s\to\infty$. Relation of the REL effect to increase of the ratio
+$\sigma_{el}(s)/\sigma_{tot}(s)$ and emergence of black ring picture at the LHC
+is underlined.",2201.00315v3
+2022-02-09,Saturation and vanishing ideals,"We consider an homogeneous ideal $I$ in the polynomial ring $S=K[x_1,\dots,$
+$x_m]$ over a finite field $K=\mathbb{F}_q$ and the finite set of projective
+rational points $\mathbb{X}$ that it defines in the projective space
+$\mathbb{P}^{m-1}$. We concern ourselves with the problem of computing the
+vanishing ideal $I(\mathbb{X})$. This is usually done by adding the equations
+of the projective space $I(\mathbb{P}^{m-1})$ to $I$ and computing the radical.
+We give an alternative and more efficient way using the saturation with respect
+to the homogeneous maximal ideal.",2202.04683v2
+2022-02-15,Accelerating Non-Negative and Bounded-Variable Linear Regression Algorithms with Safe Screening,"Non-negative and bounded-variable linear regression problems arise in a
+variety of applications in machine learning and signal processing. In this
+paper, we propose a technique to accelerate existing solvers for these problems
+by identifying saturated coordinates in the course of iterations. This is akin
+to safe screening techniques previously proposed for sparsity-regularized
+regression problems. The proposed strategy is provably safe as it provides
+theoretical guarantees that the identified coordinates are indeed saturated in
+the optimal solution. Experimental results on synthetic and real data show
+compelling accelerations for both non-negative and bounded-variable problems.",2202.07258v2
+2022-05-10,Color dipole cross section in the DGLAP improved saturation model,"We show that the geometric scaling of the dipole cross section can be
+explained using standard DGLAP perturbative evolution. The DGLAP improved
+saturation model due to the Laplace transforms method is considered at LO and
+NNLO approximations from the experimental data by relying on a
+Froissart-bounded parametrization of $F_{2}(x,Q^{2})$. These results are
+comparable with Golec-Biernat-W$\ddot{\mathrm{u}}$sthoff (GBW) model in a wide
+kinematic region $rQ_{s}$ which takes into account charm mass. The successful
+description of ${\sigma}_{\mathrm{dip}}(x,r)/\sigma_{0}$ and
+${\sigma}_{\mathrm{dip}}(rQ_{s})/\sigma_{0}$ are presented.",2205.04889v1
+2022-06-29,Saturating systems and the rank covering radius,"We introduce the concept of a rank saturating system and outline its
+correspondence to a rank-metric code with a given covering radius. We consider
+the problem of finding the value of $s_{q^m/q}(k,\rho)$, which is the minimum
+$\mathbb{F}_q$-dimension of a $q$-system in $\mathbb{F}_{q^m}^k$ which is rank
+$\rho$-saturating. This is equivalent to the covering problem in the rank
+metric. We obtain upper and lower bounds on $s_{q^m/q}(k,\rho)$ and evaluate it
+for certain values of $k$ and $\rho$. We give constructions of rank
+$\rho$-saturating systems suggested from geometry.",2206.14740v2
+2022-07-07,Small-x Evolution of the Gluon Generalized Parton Distribution Eg of the Nucleon,"We study the small-$x$ evolution equation for the gluon generalized parton
+distribution (GPD) $E_g$ of the nucleon. It is shown that $E_g$ at vanishing
+skewness exhibits the Regge behavior identical to the BFKL Pomeron, despite its
+association with nucleon helicity-flip processes. We also consider the effect
+of gluon saturation and demonstrate that $E_g$ gets saturated in the same way
+as its helicity-nonflip counterpart $H_g$. Our result has a direct impact on
+the modeling of $E_g$ as well as the small-$x$ contribution to nucleon spin sum
+rules.",2207.03378v2
+2022-07-19,Coupling between conduction and near-field radiative heat transfer in tip-plane geometry,"We analyze the coupling between conduction and radiative heat transfer in
+near-field regime between two coaxial cylinders separated by a vacuum gap. By
+solving the heat transport equation in the steady-state regime between metals
+or polar materials we highlight a flux saturation mechanism for the radiative
+transfer even without non-local effect. In the case of polar materials this
+saturation occurs in the separation distances range of 1 to 10 nm which can be
+experimentally explored.",2207.09567v1
+2022-06-02,On the Optimization of Equivalent Concurrent Computations,"In this submission, we explore the use of equality saturation to optimize
+concurrent computations. A concurrent environment gives rise to new
+optimization opportunities, like extracting a common concurrent subcomputation.
+To our knowledge, no existing equality saturation framework allows such an
+optimization. The challenge with concurrent environments is that they require
+non-local reasoning since parallel computations are inherently unrelated and
+disjoint. This submission presents a new approach to optimizing equivalent
+concurrent computations: extending e-graphs to capture equal concurrent
+computations in order to replace them with a single computation.",2208.06295v1
+2022-09-08,Large-rapidity ridge correlations from Color Glass Condensate,"Within the Color Glass Condensate (CGC) effective field theory, considering
+the violation of boost invariance of the rapidity distribution, we correct the
+normalization scheme of the longitudinal rapidity ridge correlations. After
+this correction, the large-rapidity ridge correlation rebounds after bottoming,
+consistent with the observed data from the CMS detector. It is also found that
+the correlation rebound appears around the sum of the saturation momentum of
+the projectile and target, and moves to larger rapidities at higher collision
+energies. These features directly result from the saturation and the quantum
+evolution of gluons within the framework of the CGC.",2209.03772v1
+2022-10-06,Unintegrated gluon distributions from the color dipole cross section in the BGK saturation model,"We evaluate the unintegrated gluon distribution of the proton starting from a
+parametrization of the color dipole cross section including DGLAP evolution and
+saturation effects. To this end, we perform the Fourier-Bessel transform of
+$\sigma(x,r)/\alpha(r)$. At large transverse momentum of gluons we match the
+so-obtained distribution to the logarithmic derivative of the collinear gluon
+distribution. We check our approach by calculating the proton structure
+function $F_L(x,Q^2)$ finding good agreement with HERA data.",2210.02877v1
+2022-10-17,Saturated orbit closures in the Hodge bundle,"We give a new proof of the classification of ${\rm GL}^+(2,\mathbb{R})$-orbit
+closures that are saturated for the absolute period foliation of the Hodge
+bundle. As a consequence, we obtain a short proof of the classification of
+closures of leaves of the absolute period foliation of the Hodge bundle. Our
+approach is based on a method for classifying ${\rm GL}^+(2,\mathbb{R})$-orbit
+closures using deformations of flat pairs of pants.",2210.08795v2
+2022-10-26,Scale-free linear protocol design for global regulated state synchronization of discrete-time double-integrator multi-agent systems subject to actuator saturation,"This paper studies global regulated state synchronization of discrete-time
+double-integrator multi-agent systems subject to actuator saturation by
+utilizing localized information exchange. We propose a scale-free linear
+protocol that achieves global regulated state synchronization for any network
+with arbitrary number of agents and arbitrarily directed communication graph
+that has a path between each agent and exosystem which generates the reference
+trajectory.",2210.14453v1
+2022-12-09,A theoretical study of the air-sea drag-saturation in very strong winds,"The goal of this note is to provide a theoretical explanation for the
+saturation of the drag coefficient in strong wind conditions. The hydrodynamic
+model under consideration takes into account the important effects of airborne
+droplets of water in a thin layer above the water surface that effectively
+behave as a different fluid between the water and the air. Above this layer the
+model is coupled with a log-wind profile for the strong winds blowing above the
+sea. The main underlying mechanism governing the behavior of the drag
+coefficient is the Kelvin Helmholtz instability for capillary waves on the
+water surface and the continuity of shear stress along the intermediate
+interface.",2212.04792v1
+2023-01-30,Strong Reverse Saturation and Fast-Light in Ruby,"We observe a strong reverse saturation of absorption in ruby at a wavelength
+of 473 nm. With an intensity-modulated laser, we observe that the peaks of the
+pulses appear more than a hundred microseconds earlier than the reference
+signal. A theoretical model based on coherent population oscillation would
+suggest a fast-light effect with an extremely large and negative group index of
+$-(1.7\pm0.1)\times 10^6$. We propose that this pulse advancement can also be
+described by time-dependent absorption of ruby. Our study helps to understand
+the nature of the fast- and slow-light effects in transition-metal-doped
+crystals such as ruby and alexandrite.",2301.13300v1
+2023-03-08,Robust data-driven control design for linear systems subject to input saturations,"This paper deals with the problem of providing a data-driven solution to the
+local stabilization of linear systems subject to input saturation. After
+presenting a model-based solution to this well-studied problem, a systematic
+method to transform model-driven into data-driven LMI conditions is presented.
+This technical solution is demonstrated to be equivalent to the recent advanced
+results on LMI formulations based on S-procedure or Peterson Lemmas. However,
+the advantage of the proposed method relies on its simplicity and its potential
+to be applicable to a wide class of problems of stabilization of (non)linear
+discrete-time systems. The method is then illustrated on an academic example.",2303.04455v1
+2023-03-23,Equational Theorem Proving for Clauses over Strings,"Although reasoning about equations over strings has been extensively studied
+for several decades, little research has been done for equational reasoning on
+general clauses over strings. This paper introduces a new superposition
+calculus with strings and present an equational theorem proving framework for
+clauses over strings. It provides a saturation procedure for clauses over
+strings and show that the proposed superposition calculus with contraction
+rules is refutationally complete. This paper also presents a new decision
+procedure for word problems over strings w.r.t. a set of conditional equations
+R over strings if R can be finitely saturated under the proposed inference
+system.",2303.13257v1
+2023-04-24,Existential Calculi of Relations with Transitive Closure: Complexity and Edge Saturations,"We study the decidability and complexity of equational theories of the
+existential calculus of relations with transitive closure (ECoR*) and its
+fragments, where ECoR* is the positive calculus of relations with transitive
+closure extended with complements of term variables and constants. We give
+characterizations of these equational theories by using edge saturations and we
+show that the equational theory is 1) coNP-complete for ECoR* without
+transitive closure; 2) in coNEXP for ECoR* without intersection and
+PSPACE-complete for two smaller fragments; 3) $\Pi_{1}^{0}$-complete for ECoR*.
+The second result gives PSPACE-upper bounds for some extensions of Kleene
+algebra, including Kleene algebra with top w.r.t. binary relations.",2304.12079v1
+2023-04-27,Ideals and continuity for quantaloid-enriched categories,"We study ideals in, and continuity of, quantaloid-enriched categories
+(Q-categories for short) as a 'many-valued and many-typed' generalization of
+domain theory. Abstractly, for any (saturated) class Phi of presheaves, we
+define and study the Phi-continuity of Q-categories. Concretely, we compute
+three examples of such saturated classes of presheaves - the class of flat
+ideals, the class of irreducible ideals and the class of conical ideals - which
+are proper generalizations of ideals in domain theory.",2304.14128v1
+2023-07-09,Parton shower algorithm with saturation effect,"We extend the previously developed small $x$ parton shower algorithm to
+include the kinematic constraint effect and $k_t$ resummation effect. This work
+enables the Monte Carlo generator to simultaneously resum large $k_t$ and small
+$x$ logarithms in the saturation regime for the first time. It is an important
+step towards simulating processes involving multiple well separated hard
+scales, such as di-jet production in eA collisions at EIC.",2307.04185v1
+2023-08-21,Strangeness production in neutron star matter,"Based on a dynamical model on particle production, the production and
+fraction of exotic components in neutron star matter are analyzed. It is found
+that there exists a small fraction of strangeness in twice saturation density
+matter. For five times saturation density matter, the fraction of strange
+baryons can be as high as 25-50\%, depending on the equation of state used. The
+neutron-proton asymmetry of dense matter does not significantly impact the
+strangeness fraction in neutron star matter. This research provides new
+insights into the strange components in neutron stars.",2308.10628v2
+2023-08-29,Enhancements on a saturated control for stabilizing a quadcopter: adaptive and robustness analysis in the flat output space,"This paper extends our previous study on an explicit saturated control for a
+quadcopter, which ensures both constraint satisfaction and stability thanks to
+the linear representation of the system in the flat output space. The novelty
+here resides in the adaptivity of the controller's gain to enhance the system's
+performance without exciting its parasitic dynamics and avoid lavishing the
+input actuation with excessively high gain parameters. Moreover, we provide a
+thorough robustness analysis of the proposed controller when additive
+disturbances are affecting the system behavior. Finally, simulation and
+experimental tests validate the proposed controller.",2308.15177v2
+2023-10-31,Harmonics of Lepton-Jet Correlations in inclusive and diffractive scatterings,"Based on our previous work, we study the harmonic coefficient of both
+inclusive and diffractive azimuthal angle dependent lepton-jet correlations in
+Hadron-Electron Ring Accelerator and the future electron-ion collider.
+Numerical calculations for inclusive and diffractive harmonics and the ratio of
+harmonics in $e+\text{Au}$~and $e+p$ indicate their strong discriminating power
+for non-saturation model and saturation model. Additionally, we demonstrate
+that the t-dependent diffractive harmonics can serve as novel observables for
+nuclear density profile.",2310.20662v2
+2023-10-31,Generating site saturation mutagenesis libraries and transferring them to broad host range plasmids using type IIS restriction enzymes,"Protein engineering is an established method for tailoring enzymatic
+reactivity. A commonly used method is directed evolution, where the mutagenesis
+and natural selection process is mimicked and accelerated in the laboratory.
+Here, we describe a reliable method for generating saturation mutagenesis
+libraries by golden gate cloning in a broad host range plasmid containing the
+pBBR1 replicon. The applicability is demonstrated by generating a mutant
+library of the iron nitrogenase gene cluster (anfHDGK) of Rhodobacter
+capsulatus, which is subsequently screened for the improved formation of
+molecular hydrogen.",2311.00138v1
+2023-11-01,Diffractive single and di-hadron production at the NLO in a saturation framework,"Motivated by the need to increase the precision of theoretical predictions to
+test saturation physics at both the LHC and the EIC, we compute the
+cross-sections for the diffractive single and di-hadron production at the NLO
+in the shockwave formalism.",2311.00383v1
+2023-11-08,Sharper analysis of the random graph $d$-process via a balls-in-bins model,"A graph $d$-process starts with an empty graph on $n$ vertices, and adds one
+edge at each time step, chosen uniformly at random from those pairs which are
+not yet edges and whose both vertices have current degree less than $d$. If, in
+the final graph, at most one vertex has degree $d-1$ and all other have degree
+$d$, we call the process saturated. We present a new approach to analysing this
+process based on random allocation of balls in bins. This allows us to get
+improved results on the degree distribution throughout the process and,
+consequently, to determine the asymptotic probability of non-saturation of the
+process.",2311.04743v1
+2023-11-13,Cylindric Schur functions,"We generalize several classical results about Schur functions to the family
+of cylindric Schur functions. First, we give a combinatorial proof of a
+Murnaghan--Nakayama formula for expanding cylindric Schur functions in the
+power-sum basis. We also explore some cases where this formula is
+cancellation-free.
+  The second result is polynomiality of Kostka coefficients associated with
+stretched row-flagged skew Schur functions. This implies polynomiality of
+stretched cylindric Kostka coefficients. This generalizes a result by E.
+Rassart from 2004.
+  Finally, we also show the saturation property for the row-flagged skew Kostka
+coefficients which also implies the saturation property for cylindric Schur
+functions.",2311.07382v1
+2023-11-15,Killing Spinors for Finite Temperature Euclidean Solutions at the BPS Bound,"In a recent paper [arXiv:2308.00038], Anupam, Chowdhury, and Sen conjectured
+that the finite temperature Euclidean five-dimensional Cvetic-Youm solution
+saturating the BPS bound is supersymmetric. In this paper, we explicitly
+construct Killing spinors for this solution in five-dimensional minimal
+supergravity. We also expand on the previous discussions of Killing spinors for
+the finite temperature Euclidean Kerr-Newman solution saturating the BPS bound.
+For both these cases, we show that the total charge gets divided into two
+harmonic sources on three-dimensional flat base space.",2311.09427v2
+2023-11-23,Saturated theorem along cubes for a measure and applications,"We show that for a minimal system $(X,T)$, the set of saturated points along
+cubes with respect to its maximal $\infty$-step pro-nilfactor $X_\infty$ has a
+full measure. As an application, it is shown that if a minimal system $(X,T)$
+has no non-trivial $(k+1)$-tuples with arbitrarily long finite IP-independence
+sets, then it has only at most $k$ ergodic measures and is an almost $k'$ to
+one extension of $X_\infty$ for some $k'\leqslant k$. Particularly, for $k=1$
+we prove that $(X,T)$ is uniquely ergodic (even regular with respect to
+$X_\infty$), which answers a conjecture stated in [3].",2311.14198v1
+2023-12-31,Contractibility of the orbit space of a saturated fusion system after Steinberg,"Recently, Steinberg used discrete Morse theory to give a new proof of a
+theorem of Symonds that the orbit space of the poset of nontrivial
+$p$-subgroups of a finite group is contractible. We extend Steinberg's argument
+in two ways, covering more general versions of the theorem that were already
+known. In particular, following a strategy of Libman, we give a discrete Morse
+theoretic argument for the contractibility of the orbit space of a saturated
+fusion system.",2401.00531v2
+2024-01-18,Harmonic Generation in a Terawatt X-Ray Free-Electron Laser,"Terawatt x-ray free-electron lasers (XFELs) require high current densities
+with strong transverse focusing. The implications on harmonic generation are
+discussed using the MINERVA simulation code which self-consistently includes
+harmonic generation. We consider helical and planar undulators where the
+fundamental is at 1.5 Angstrom and study the associated harmonic generation.
+While tapered undulators are needed to reach TW powers at the fundamental, the
+taper does not enhance the harmonics because the taper must start before
+saturation of the fundamental, with the harmonics saturating earlier.
+Nevertheless, the harmonics reach substantial powers and enable enhanced
+applications.",2401.09971v1
+2024-01-28,Fusion invariant characters of p-groups,"We consider complex characters of a p-group P, which are invariant under a
+fusion system F on P. Extending a theorem of B\'arcenas--Cantarero to
+non-saturated fusion systems, we show that the number of indecomposable
+F-invariant characters of P is greater or equal than the number of F-conjugacy
+classes of P. We further prove that these two quantities coincide whenever F is
+realized by a p-solvable group. On the other hand, we observe that this is
+false for constrained fusion systems in general. Finally, we construct a
+saturated fusion system with an indecomposable F-invariant character, which is
+not a summand of the regular character of P. This disproves a recent conjecture
+of Cantarero--Combariza.",2401.15706v2
+2024-01-31,SAT-Based Subsumption Resolution,"Subsumption resolution is an expensive but highly effective simplifying
+inference for first-order saturation theorem provers. We present a new
+SAT-based reasoning technique for subsumption resolution, without requiring
+radical changes to the underlying saturation algorithm. We implemented our work
+in the theorem prover Vampire, and show that it is noticeably faster than the
+state of the art.",2401.17832v1
+2024-02-02,Degenerate diffusion in porous media with hysteresis-dependent permeability,"Hysteresis in the pressure-saturation relation in unsaturated porous media,
+which is due to surface tension on the liquid-gas interface, exhibits strong
+degeneracy in the resulting mass balance equation. Solutions to such degenerate
+equations have been recently constructed by the method of convexification. We
+show here that the convexification argument works even if the permeability
+coefficient depends on the hysteretic saturation. The problem of uniqueness
+remains open in this case.",2402.01278v1
+2024-02-15,Exploiting spacetime symmetry in dissipative nonlinear multimode amplifiers for output control,"Time-reversal symmetry enables shaping input waves to control output waves in
+many linear and nonlinear systems; however energy dissipation violates such
+symmetry. We consider a saturated multimode fiber amplifier in which light
+generates heat flow and suffers nonlinear thermo-optical scattering, breaking
+time-reversal symmetry. We identify a spacetime symmetry which maps the target
+output back to an input field. This mapping employs phase conjugation, gain and
+absorption substitution but not time reversal, and holds in steady-state and
+for slowly varying inputs. Our results open the possibility of output control
+of a saturated multimode fiber amplifier.",2402.10345v1
+2024-02-22,"Saturating linear sets in PG$(2,q^4)$","Bonini, Borello and Byrne started the study of saturating linear sets in
+Desarguesian projective spaces, in connection with the covering problem in the
+rank metric. In this paper we study \emph{$1$-saturating} linear sets in
+PG$(2,q^4)$, that is $\mathbb{F}_q$-linear sets in PG$(2,q^4)$ with the
+property that their secant lines cover the entire plane. By making use of a
+characterization of generalized Gabidulin codes, we prove that the rank of such
+a linear set is at least $5$. This answers to a recent question posed by
+Bartoli, Borello and Marino.",2402.14387v1
+2017-11-11,280 GHz Focal Plane Unit Design and Characterization for the SPIDER-2 Suborbital Polarimeter,"We describe the construction and characterization of the 280 GHz bolometric
+focal plane units (FPUs) to be deployed on the second flight of the
+balloon-borne SPIDER instrument. These FPUs are vital to SPIDER's primary
+science goal of detecting or placing an upper limit on the amplitude of the
+primordial gravitational wave signature in the cosmic microwave background
+(CMB) by constraining the B-mode contamination in the CMB from Galactic dust
+emission. Each 280 GHz focal plane contains a 16 x 16 grid of corrugated
+silicon feedhorns coupled to an array of aluminum-manganese transition-edge
+sensor (TES) bolometers fabricated on 150 mm diameter substrates. In total, the
+three 280 GHz FPUs contain 1,530 polarization sensitive bolometers (765 spatial
+pixels) optimized for the low loading environment in flight and read out by
+time-division SQUID multiplexing. In this paper we describe the mechanical,
+thermal, and magnetic shielding architecture of the focal planes and present
+cryogenic measurements which characterize yield and the uniformity of several
+bolometer parameters. The assembled FPUs have high yields, with one array as
+high as 95% including defects from wiring and readout. We demonstrate high
+uniformity in device parameters, finding the median saturation power for each
+TES array to be ~3 pW at 300 mK with a less than 6% variation across each array
+at one standard deviation. These focal planes will be deployed alongside the 95
+and 150 GHz telescopes in the SPIDER-2 instrument, slated to fly from McMurdo
+Station in Antarctica in December 2018.",1711.04169v2
+2016-09-27,The magnetic properties of the hollow cylindrical ideal remanence magnet,"We consider the magnetic properties of the hollow cylindrical ideal remanence
+magnet. This magnet is the cylindrical permanent magnet that generates a
+uniform field in the cylinder bore, using the least amount of magnetic energy
+to do so. The remanence distribution of this magnet is derived and the
+generated field is compared to that of a Halbach cylinder of equal dimensions.
+The ideal remanence magnet is shown in most cases to generate a significantly
+lower field than the equivalent Halbach cylinder, although the field is
+generated with higher efficiency. The most efficient Halbach cylinder is shown
+to generate a field exactly twice as large as the equivalent ideal remanence
+magnet.",1609.08548v1
+2022-07-19,Magnetic Field of a Permanent Magnet,"For magnetic field calculations, cylindrical permanent magnets are often
+approximated as ideal, azimuthally symmetric solenoids. Despite the frequent
+usage of this approximation, research papers demonstrating the validity and
+limitations of this approach are scarcely available. In this paper, the
+experimentally derived magnetic field of a cylindrical permanent magnet is
+compared with the analytically calculated magnetic field of an ideal solenoid.
+An experimental setup for measuring the magnetic field distribution is
+demonstrated and employed for gathering the data. The proposed setup allows to
+measure the distributions of the axial and radial components of the magnetic
+field surrounding the magnet. The experimental data is in a very good agreement
+with the theoretical predictions, confirming the validity of using the model of
+an ideal solenoid for predicting a magnetic field distribution of a permanent
+magnet.",2207.09911v1
+2022-09-09,Magnetization dynamics and reversal of two-dimensional magnets,"Micromagnetics simulation based on the classical Landau-Lifshitz-Gilbert
+(LLG) equation has long been a powerful method for modeling magnetization
+dynamics and reversal of three-dimensional (3D) magnets. For two-dimensional
+(2D) magnets, the magnetization reversal always accompanies the collapse of the
+magnetization even at low temperatures due to intrinsic strong spin
+fluctuation. We propose a micromagnetic theory that explicitly takes into
+account the rapid demagnetization and remagnetization dynamics of 2D magnets
+during magnetization reversal. We apply the theory to a single-domain magnet to
+illustrate fundamental differences in magnetization trajectories and reversal
+times for 2D and 3D magnets.",2209.04483v1
+2003-07-30,Apparent Sizes and Spectral Line Profiles for Spherical and Disk Masers: Solutions to the Full Equations,"Calculations are performed for the spectral line profiles and images of
+astrophysical maser radiation that emerges from isolated spheres and thin disks
+viewed edge-on. In contrast to previous investigations where various
+approximations are made, the full equations are solved here for the
+frequency-dependent radiative transport that includes the thermal motion of the
+molecules. The spectral line profiles for spheres and disks are found to
+rebroaden to the full thermal Doppler breadth with increasing saturation in
+essentially the same way as is well known to occur for a linear maser. The
+variation with frequency in the apparent angular sizes of masing spheres and
+thin disks is found to be negligible at frequencies within the spectral line
+where the flux is significant. Calculations also are performed for spherical
+and disk masers that are not isolated, but for which the seed radiation for the
+masers is incident from one side as would occur when a strong continuum source
+is on the far side of the masers. Again, the spectral line profiles are found
+to rebroaden to the full thermal breadths with increasing saturation and there
+are no significant variations in the apparent angular sizes with frequency.
+However, the full rebroadening does occur at somewhat higher saturation and the
+variation of the apparent angular sizes as a function of the degree of
+saturation is quite different from that of the isolated masers. Spheres and
+disks have served as idealized geometries with which to examine possible
+deviations from the linear approximation for astrophysical masers.",0307541v1
+2006-02-04,Comprehensive Analysis of RXTE Data from Cyg X-1: Spectral Index-Quasi-Periodic Oscillation Frequency-Luminosity Correlations,"We present timing and spectral analysis of ~ 2.2 Ms of RXTE archival data
+from Cyg X-1. Using a generic Comptonization model we reveal that the spectrum
+of Cyg X-1 consists of three components: a thermal seed photon spectrum, a
+Comptonized part of the seed photon spectrum and the iron line. We find a
+strong correlation between the 0.1-20 Hz frequencies of quasiperiodic
+oscillations (QPOs) and the spectral index. Presence of two spectral phases
+(states) are clearly seen in the data when the spectral indices saturate at low
+and high values of QPO frequencies. This saturation effect was discovered
+earlier in a number of black hole candidate (BHC) sources and now we strongly
+confirm this phenomenon in Cyg X-1. In the soft state this index-QPO frequency
+correlation shows a saturation of the photon index Gamma ~ 2.1 at high values
+of the low frequency \nu_{L}. The saturation level of Gamma~ 2.1 is the lowest
+value found yet in BHCs. The bolometric luminosity does not show clear
+correlation with the index. We also show that Fe K_{\alpha} emission line
+strength (equivalent width, EW) correlates with the QPO frequency. The EW
+increases from 200 eV in the low/hard state to 1.5 keV in the high/soft state.
+The observational correlations revealed compel us to propose a scenario for the
+spectral transition and iron line formation which occur in BHC sources. We also
+present the spectral state (power-law index) evolution for eight years of Cyg
+X-1 observations by RXTE.",0602091v1
+2007-02-15,Amplitude Saturation in Beta Cephei Models,"Although the driving mechanism acting in beta Cephei pulsators is well known
+(e.g. Dziembowski & Pamyatnykh 1993), problems concerning identification of
+amplitude limitation mechanism and non-uniform filling of the theoretical
+instability strip, remain to be solved. In the present analysis, these problems
+are addressed by non-linear modelling of radial pulsations of these stars. In
+this approach radial modes are treated as representative for all acoustic
+oscillations.
+  Several models of different masses and metallicities were converged to limit
+cycles through Stellingwerf (1974) relaxation technique. Resulting peak-to-peak
+amplitudes are of order of DeltaV=0.3 mag. Such amplitudes are significantly
+larger than those observed in beta Cephei pulsators. Assuming that all acoustic
+modes are similar, we show that collective saturation of the driving mechanism
+by several acoustic modes can easily lower predicted saturation amplitudes to
+the observed level. Our calculations predict significant decrease of saturation
+amplitudes as we go to high mass/high luminosity models. However, this effect
+is not strong enough to explain scarcity of high mass beta Cephei variables.
+  We also discuss robust double-mode behaviour, encountered in our radiative
+models. On a single evolutionary track we identify two double-mode domains with
+two different mechanisms resposible for double-mode behaviour. The non-resonant
+double-mode domain separates first overtone and fundamental mode pulsation
+domains. The resonant double-mode domain appears in the middle of the first
+overtone pulsation domain. Its origin can be traced to the
+2omega_1=omega_0+omega_2 parametric resonance, which destabilizes the first
+overtone limit cycle.",0702406v1
+2003-08-09,Photo-physical and nonlinear-optical properties of a new polymer: hydroxylated pyridyl para-phenylene,"Photo-physical and nonlinear-optical properties of a new amphiphilic
+conjugated polymer: hydroxylated pyridyl para-phenylene (Py-PhPPP) both in
+CH2Cl2 solution and in thin films have been investigated. By using Z-scan
+technique with nanosecond laser pulses of wavelengths ranging from 430 to 600
+nm, the large nonlinear absorption and refraction have been determined in terms
+of the effective third-order, nonlinear-optical susceptibilities. These Z-scans
+reveal that the nonlinear absorption alters from reverse saturable absorption
+to saturable absorption at wavelength of ~ 540 nm. Similarly, alteration from
+self-defocusing to self-focusing manifests itself at the same wavelength. The
+optical limiting performance of Py-PhPPP in solution is superior to toluene
+solution of [60]fullerene (C60) at 532 nm. Both UV-visible absorption spectra
+and photoluminescence (PL) spectra show concentration dependence. The PL
+spectra also depend on excitation wavelengths. These evidences suggest that the
+aggregate formation should play an important role in the nonlinear-optical
+properties of the new polymer. We attribute the reverse saturable absorption in
+the region of blue and green wavelengths mainly to intra-chain, triplet-triplet
+absorption while the absorption bleaching at longer wavelengths is due to
+saturation in the absorption band induced by the aggregates.",0308183v1
+2005-01-19,Saturation of Electrostatic Potential: Exactly Solvable 2D Coulomb Models,"We test the concepts of renormalized charge and potential saturation,
+introduced within the framework of highly asymmetric Coulomb mixtures, on
+exactly solvable Coulomb models. The object of study is the average
+electrostatic potential induced by a unique ""guest"" charge immersed in a
+classical electrolyte, the whole system being in thermal equilibrium at some
+inverse temperature $\beta$. The guest charge is considered to be either an
+infinite hard wall carrying a uniform surface charge or a charged colloidal
+particle. The systems are treated as two-dimensional; the electrolyte is
+modelled by a symmetric two-component plasma of point-like $\pm e$ charges with
+logarithmic Coulomb interactions. Two cases are solved exactly: the
+Debye-H\""uckel limit $\beta e^2\to 0$ and the Thirring free-fermion point
+$\beta e^2 = 2$. The results at the free-fermion point can be summarized as
+follows: (i) The induced electrostatic potential exhibits the asymptotic
+behavior, at large distances from the guest charge, whose form is different
+from that obtained in the Debye-H\""uckel (linear Poisson-Boltzmann) theory.
+This means that the concept of renormalized charge, developed within the
+nonlinear Poisson-Boltzmann theory to describe the screening effect of the
+electrolyte cloud, fails at the free-fermion point. (ii) In the limit of an
+infinite bare charge, the induced electrostatic potential saturates at a finite
+value in every point of the electrolyte region. This fact confirms the
+previously proposed hypothesis of potential saturation.",0501442v1
+2000-11-28,A geometrical estimation of saturation of partonic densities,"We propose a new criterium for saturation of the density of partons both in
+nucleons and nuclei. It is applicable to any multiple scattering model which
+would be used to compute the number of strings exchanged in $ep$ and $eA$
+collisions. The criterium is based on percolation of strings, and the onset of
+percolation is estimated from expectations coming from the study of heavy ion
+collisions at high energies. We interpret this onset as an indication of
+saturation of the density of partons in the wave function of the hadron. In
+order to produce quantitative results, a particular model fitted to describe
+present HERA data and generalized to the nuclear case is used. Nevertheless,
+with the number of scatterings controlled by the relation between inclusive and
+diffractive processes, conclusions are weakly model-dependent as long as
+different models are tuned to describe the experimental data. This constitutes
+a new approach, based on the eikonal description of soft hadronic collisions,
+and different from others which employ either perturbative QCD ideas or
+semiclassical methods. It offers an alternative picture for saturation in the
+small $Q^2$ region.",0011352v3
+2002-02-03,"S-Matrix Unitarity, Impact Parameter Profiles, Gluon Saturation and High-Energy Scattering","A model combining perturbative and non-perturbative QCD is developed to
+compute high-energy reactions of hadrons and photons and to investigate
+saturation effects that manifest the S-matrix unitarity. Following a functional
+integral approach, the S-matrix factorizes into light-cone wave functions and
+the universal amplitude for the scattering of two color-dipoles which are
+represented by Wegner-Wilson loops. In the framework of the non-perturbative
+stochastic vacuum model of QCD supplemented by perturbative gluon exchange, the
+loop-loop correlation is calculated and related to lattice QCD investigations.
+With a universal energy dependence motivated by the two-pomeron (soft + hard)
+picture that respects the unitarity condition in impact parameter space, a
+unified description of pp, pip, Kp, gamma* p, and gamma gamma reactions is
+achieved in good agreement with experimental data for cross sections, slope
+parameters, and structure functions. Impact parameter profiles for pp and
+longitudinal gamma* p reactions and the gluon distribution of the proton
+xG(x,Q^2,b) are calculated and found to saturate in accordance with S-matrix
+unitarity. The c.m. energies and Bjorken x at which saturation sets in are
+determined.",0202012v2
+2002-06-07,The Colour Glass Condensate,"I briefly review the physical picture of the saturated gluons at small-x as a
+Colour Glass Condensate, and the effective theory which forms the basis of this
+picture.",0206073v1
+2002-06-24,Froissart Bound from Gluon Saturation,"We demonstrate that the dipole-hadron cross-section computed from the
+non-linear evolution equation for the Colour Glass Condensate saturates the
+Froissart bound in the case of a fixed coupling and for a small dipole (Q^2 >>
+Lambda_{QCD}^2). That is, the cross-section increases as the logarithm squared
+of the energy, with a proportionality coefficient involving the pion mass and
+the BFKL intercept (alpha_s N_c/pi)4 ln 2. The pion mass enters via the
+non-perturbative initial conditions at low energy. The BFKL equation emerges as
+a limit of the non-linear evolution equation valid in the tail of the hadron
+wavefunction. We provide a physical picture for the transverse expansion of the
+hadron with increasing energy, and emphasize the importance of the colour
+correlations among the saturated gluons in suppressing non-unitary
+contributions due to long-range Coulomb tails. We present the first calculation
+of the saturation scale including the impact parameter dependence. We show that
+the cross-section at high energy exhibits geometric scaling with a different
+scaling variable as compared to the intermediate energy regime.",0206241v2
+2004-08-19,Numerical analysis of the Balitsky-Kovchegov equation with running coupling: dependence of the saturation scale on nuclear size and rapidity,"We study the effects of including a running coupling constant in high-density
+QCD evolution. For fixed coupling constant, QCD evolution preserves the initial
+dependence of the saturation momentum $Q_s$ on the nuclear size $A$ and results
+in an exponential dependence on rapidity $Y$, $Q^2_s(Y) = Q^2_s(Y_0) \exp{[
+\bar\alpha_s d (Y-Y_0) ]}$. For the running coupling case, we re-derive
+analytical estimates for the $A$- and $Y$-dependences of the saturation scale
+and test them numerically. The $A$-dependence of $Q_s$ vanishes $\propto 1/
+\sqrt{Y}$ for large $A$ and $Y$. The $Y$-dependence is reduced to $Q_s^2(Y)
+\propto \exp{(\Delta^\prime\sqrt{Y+X})}$ where we find numerically
+$\Delta^\prime\simeq 3.2$. We study the behaviour of the gluon distribution at
+large transverse momentum, characterizing it by an anomalous dimension
+$1-\gamma$ which we define in a fixed region of small dipole sizes. In contrast
+to previous analytical work, we find a marked difference between the fixed
+coupling ($\gamma \simeq 0.65$) and running coupling ($\gamma \sim 0.85$)
+results. Our numerical findings show that both a scaling function depending
+only on the variable $r Q_s$ and the perturbative double-leading-logarithmic
+expression, provide equally good descriptions of the numerical solutions for
+very small $r$-values below the so-called scaling window.",0408216v2
+2005-06-16,Saturation 2005 (mini-review),"This talk was given at DIS'05 (Madison, April 27-May 2, 2005). It is a brief
+review of ups and downs of high density QCD during the past year.",0506161v1
+2006-06-23,A zero-dimensional model for high-energy scattering in QCD,"We investigate a zero-dimensional toy model originally introduced by Mueller
+and Salam which mimics high-energy scattering in QCD in the presence of both
+gluon saturation and gluon number fluctuations, and hence of Pomeron loops.
+Unlike other toy models of the reaction-diffusion type, the model studied in
+this paper is consistent with boost invariance and, related to that, it
+exhibits a mechanism for particle saturation close to that of the JIMWLK
+equation in QCD, namely the saturation of the emission rate due to high-density
+effects. Within this model, we establish the dominant high-energy behaviour of
+the S-matrix element <S^n> for the scattering between a target obtained by
+evolving one particle and a projectile made with exactly n particles.
+Remarkably, we find that all such matrix elements approach the black disk limit
+S=0 at high rapidity Y, with the same exponential law: <S^n> ~ exp(-Y) for all
+values of n. This is so because the S-matrix is dominated by rare target
+configurations which involve only few particles. We also find that the bulk
+distribution for a saturated system is of the Poisson type.",0606253v3
+2006-07-04,"DIS at low x, saturation scale, gluon structure function and vector-meson production","Deep inelastic scattering at low x can be described by essentially only two
+fitted parameters. The interpretation of J/Psi photoproduction in terms of the
+gluon structure function is elaborated upon.",0607031v1
+2007-01-25,Compatibility of phenomenological dipole cross sections with the Balitsky-Kovchegov equation,"Phenomenological models of the dipole cross section that enters in the
+description of for instance deep inelastic scattering at very high energies
+have had considerable success in describing the available small-x data in both
+the saturation region and the so-called extended geometric scaling (EGS)
+region. We investigate to what extent such models are compatible with the
+numerical solutions of the Balitsky-Kovchegov (BK) equation which is expected
+to describe the nonlinear evolution in x of the dipole cross section in these
+momentum regions. We find that in the EGS region the BK equation yields results
+that are qualitatively different from those of phenomenological studies. In
+particular, geometric scaling around the saturation scale is only obtained at
+asymptotic rapidities. We find that in this limit, the anomalous dimension
+\gamma(r,x) of phenomenological models approaches a limiting function that is
+universal for a large range of initial conditions. At the saturation scale,
+this function equals approximately 0.44, in contrast to the value 0.628
+commonly used in the models. We further investigate the dependence of these
+results on the starting distribution, the small-r limit of the anomalous
+dimension for fixed rapidities and the x-dependence of the saturation scale.",0701219v2
+1995-04-24,Some comments on $N=2$ supersymmetric Yang-Mills,"We comment on some aspects of the semiclassical BPS saturated states close to
+the curve $Im a_{D}/a =0$",9504120v1
+1998-01-12,Probing Matrix Black Holes,"Black holes in matrix theory may consist of interacting clusters (correlated
+domains) which saturate the uncertainty principle. We show that this assumption
+qualitatively accounts for the thermodynamic properties of both charged and
+neutral black holes, and reproduces the asymptotic geometry seen by probes.",9801070v1
+2000-12-30,BPS Vortices in Brane-Antibrane Effective Theory,"We investigate an action which resembles the effective action of
+brane-antibrane system derived from boundary string field theory. We find that
+the action has smooth vortex solutions which saturate the Bogomol'nyi bound.",0101002v1
+2002-08-29,Minimalisation of uncertainty relations in noncommutative quantum mechanics,"The explicit constrtuction of states saturating uncertainty relations
+following from basic commutation rules of NCQM is given both in Fock space and
+coordinate representation",0208213v1
+1995-11-24,Highly saturated packings and reduced coverings,"We introduce and study certain notions which might serve as substitutes for
+maximum density packings and minimum density coverings. A body is a compact
+connected set which is the closure of its interior. A packing $\cal P$ with
+congruent replicas of a body $K$ is $n$-saturated if no $n-1$ members of it can
+be replaced with $n$ replicas of $K$, and it is completely saturated if it is
+$n$-saturated for each $n\ge 1$. Similarly, a covering $\cal C$ with congruent
+replicas of a body $K$ is $n$-reduced if no $n$ members of it can be replaced
+by $n-1$ replicas of $K$ without uncovering a portion of the space, and it is
+completely reduced if it is $n$-reduced for each $n\ge 1$. We prove that every
+body $K$ in $d$-dimensional Euclidean or hyperbolic space admits both an
+$n$-saturated packing and an $n$-reduced covering with replicas of $K$. Under
+some assumptions on $K\subset \mathbb{E}^d$ (somewhat weaker than convexity),
+we prove the existence of completely saturated packings and completely reduced
+coverings, but in general, the problem of existence of completely saturated
+packings and completely reduced coverings remains unsolved. Also, we
+investigate some problems related to the the densities of $n$-saturated
+packings and $n$-reduced coverings. Among other things, we prove that there
+exists an upper bound for the density of a $d+2$-reduced covering of
+$\mathbb{E}^d$ with congruent balls, and we produce some density bounds for the
+$n$-saturated packings and $n$-reduced coverings of the plane with congruent
+circles.",9511225v1
+1998-04-15,Main gap for locally saturated elementary submodels of a homogeneous structure,"We prove a main gap theorem for e-saturated submodels of a homogeneous
+structure. We also study the number of e-saturated models, which are not
+elementarily embeddable to each other",9804157v1
+1998-07-15,More on Weak Diamond,"We deal with the combinatorial principle Weak Diamond, showing that we always
+either a local version is not saturated or we can increase the number of
+colours. Then we point out a model theoretic consequence of Weak Diamond.",9807180v2
+2001-07-29,Weak Diamond,"Under some cardinal arithmetic assumptions, we prove that every stationary
+subset of lambda of a right cofinality has the weak diamond. This is a strong
+negation of uniformization. We then deal with a weaker version of the weak
+diamond- colouring restrictions. We then deal with semi- saturated (normal)
+filters.",0107207v1
+2005-07-18,Asymptotically saturated toric algebras,"We show the finite generation of certain invariant graded algebras defined on
+toric weak log Fano fibrations. These are the toric version of FGA algebras,
+recently introduced by Shokurov in connections to the existence of flips.",0507350v1
+2006-08-07,Ind- and Pro- definable sets,"We describe the ind- and pro- categories of the category of definable sets,
+in some first order theory, in terms of points in a sufficiently saturated
+model.",0608163v1
+2006-12-11,Subsheaves of a hermitian torsion free coherent sheaf on an arithmetic variety,"In this paper, we consider a finiteness problem of saturated subsheaves of a
+hermitian locally free sheaf on an arithmetic variety. As an application, we
+could prove the unique existence of an arithmetic Harder-Narasimham filtration.",0612268v1
+2007-03-16,Reflexive abelian groups and measurable cardinals and saturated MAD families,"Answering a problem of Eklof and Mekler, we show that there is a reflexive
+group of cardinality >= first measurable.",0703493v3
+2007-02-14,The propagation of the light beam at the interface between uniform media and periodic media,"We considered the wave propagation between two medias. For description of
+physical model choose nonlinear Schredinger equation with saturation parameter.
+The solutions of respectively equation are found and analyzed.",0702030v1
+2005-05-03,"Parton energy loss, saturation, and recombination at BRAHMS","Particle production as observed with the BRAHMS experiment at RHIC is
+presented. Preliminary baryon/meson ratios and nuclear modification factors at
+different rapidities will be discussed.",0505004v2
+2004-11-19,Generalization of Child-Langmuir Law for Non-Zero Injection Velocities in a Planar Diode,"The Child-Langmuir law relates the voltage applied across a planar diode to
+the saturation value J_CL of current density that can be transmitted through it
+in case the injection velocity of electrons into the diode is zero. The
+Child-Langmuir current density J_CL is, at the same time, (i) the maximum
+current density that can be transmitted through a planar diode, (ii) the
+current density below which the flow is steady and unidirectional in the long
+time limit and (iii) the average transmitted current density for {\em any}
+value of injected current density above J_CL. Existing generalizations of
+Child-Langmuir law to non-zero velocities of injection are based on the
+characteristics (i) and (ii) of J_CL. This paper generalizes the law to
+non-zero velocities of injection based on the characteristic (iii) by deriving
+an analytical expression for the saturation value of current density. The
+analytical expression for the saturation current density is found to be well
+supported by numerical computations. A reason behind preferring the saturation
+property of the Child-Langmuir current density as the basis for its
+generalization is the importance of that property in numerical simulations of
+high current diode devices.",0411175v1
+2007-05-16,Vortical and Wave Modes in 3D Rotating Stratified Flows: Random Large Scale Forcing,"Utilizing an eigenfunction decomposition, we study the growth and spectra of
+energy in the vortical and wave modes of a 3D rotating stratified fluid as a
+function of $\epsilon = f/N$. Working in regimes characterized by moderate
+Burger numbers, i.e. $Bu = 1/\epsilon^2 < 1$ or $Bu \ge 1$, our results
+indicate profound change in the character of vortical and wave mode
+interactions with respect to $Bu = 1$. As with the reference state of
+$\epsilon=1$, for $\epsilon < 1$ the wave mode energy saturates quite quickly
+and the ensuing forward cascade continues to act as an efficient means of
+dissipating ageostrophic energy. Further, these saturated spectra steepen as
+$\epsilon$ decreases: we see a shift from $k^{-1}$ to $k^{-5/3}$ scaling for
+$k_f < k < k_d$ (where $k_f$ and $k_d$ are the forcing and dissipation scales,
+respectively). On the other hand, when $\epsilon > 1$ the wave mode energy
+never saturates and comes to dominate the total energy in the system. In fact,
+in a sense the wave modes behave in an asymmetric manner about $\epsilon = 1$.
+With regard to the vortical modes, for $\epsilon \le 1$, the signatures of 3D
+quasigeostrophy are clearly evident. Specifically, we see a $k^{-3}$ scaling
+for $k_f < k < k_d$ and, in accord with an inverse transfer of energy, the
+vortical mode energy never saturates but rather increases for all $k < k_f$. In
+contrast, for $\epsilon > 1$ and increasing, the vortical modes contain a
+progressively smaller fraction of the total energy indicating that the 3D
+quasigeostrophic subsystem plays an energetically smaller role in the overall
+dynamics.",0705.2452v2
+2007-07-06,Internal sets and internal functions in Colombeau theory,"Inspired by nonstandard analysis, we define and study internal subsets and
+internal functions in algebras of Colombeau generalized functions. We prove a
+saturation principle for internal sets and provide applications to Colombeau
+algebras.",0707.0994v1
+2007-07-09,Antikaons and hyperons in nuclear matter with saturation,"We evaluate the antikaon and hyperon spectral functions in a self-consistent
+and covariant many-body approach. The computation is based on coupled-channel
+dynamics derived from the chiral SU(3) Lagrangian. A novel subtraction scheme
+is developed that avoids kinematical singularities and medium-induced power
+divergencies all together. Scalar and vector mean fields are used to model
+nuclear binding and saturation. The effect of the latter is striking for the
+antikaon spectral function that becomes significantly more narrow at small
+momenta. Attractive mass shifts of about 30 and 40 MeV are predicted for the
+Lambda(1405) and Sigma(1385) resonances. Once scalar and vector mean fields for
+the nucleon are switched on the Lambda(1520) resonances dissolves almost
+completely in nuclear matter. All together only moderate attraction is
+predicted for the nuclear antikaon systems at saturation density. However, at
+larger densities we predict a sizable population of soft antikaon modes that
+arise from the coupling of the antikaon to a highly collective Lambda(1115)
+nucleon-hole state. This may lead to the formation of exotic nuclear systems
+with strangeness and antikaon condensation in compact stars at moderate
+densities.",0707.1283v2
+2007-07-12,Donor binding energy and thermally activated persistent photoconductivity in high mobility (001) AlAs quantum wells,"A doping series of AlAs (001) quantum wells with Si delta-modulation doping
+on both sides reveals different dark and post-illumination saturation
+densities, as well as temperature dependent photoconductivity. The lower dark
+two-dimensional electron density saturation is explained assuming deep binding
+energy of Delta_DK = 65.2 meV for Si-donors in the dark. Persistent
+photoconductivity (PPC) is observed upon illumination, with higher saturation
+density indicating shallow post-illumination donor binding energy. The
+photoconductivity is thermally activated, with 4 K illumination requiring
+post-illumination annealing to T = 30 K to saturate the PPC. Dark and
+post-illumination doping efficiencies are reported.",0707.1796v4
+2007-09-05,Evaporation and condensation of spherical interstellar clouds. Self-consistent models with saturated heat conduction and cooling,"Shortened version: The fate of IS clouds embedded in a hot tenuous medium
+depends on whether the clouds suffer from evaporation or whether material
+condensates onto them. Analytical solutions for the rate of evaporative mass
+loss from an isolated spherical cloud embedded in a hot tenuous gas are deduced
+by Cowie & McKee (1977). In order to test the validity of the analytical
+results for more realistic IS conditions the full hydrodynamical equations must
+be treated. Therefore, 2D numerical simulations of the evolution of IS clouds
+%are performed with different internal density structures and surrounded by a
+hot plasma reservoir. Self-gravity, interstellar heating and cooling effects
+and heat conduction by electrons are added. Classical thermal conductivity of a
+fully ionized hydrogen plasma and saturated heat flux are considered. Using
+pure hydrodynamics and classical heat flux we can reproduce the analytical
+results. Heat flux saturation reduces the evaporation rate by one order of
+magnitude below the analytical value. The evolution changes totally for more
+realistic conditions when interstellar heating and cooling effects stabilize
+the self-gravity. Evaporation then turns into condensation, because the
+additional energy by heat conduction can be transported away from the interface
+and radiated off efficiently from the cloud's inner parts. I.e. that the
+saturated heat flux consideration is inevitable for IS clouds embedded in hot
+tenuous gas. Various consequences are discussed in the paper.",0709.0623v1
+2007-10-15,Non-LTE dust nucleation in sub-saturated vapors,"We use the kinetic theory of nucleation to explore the properties of dust
+nucleation in sub-saturated vapors. Due to radiation losses, the sub-critical
+clusters have a smaller temperature compared to their vapor. This alters the
+dynamical balance between attachment and detachment of monomers, allowing for
+stable nucleation of grains in vapors that are sub-saturated for their
+temperature. We find this effect particularly important at low densities and in
+the absence of a strong background radiation field. We find new conditions for
+stable nucleation in the n-T phase diagram. The nucleation in the non-LTE
+regions is likely to be at much slower rate than in the super-saturated vapors.
+We evaluate the nucleation rate, warning the reader that it does depend on
+poorly substantiated properties of the macro-molecules assumed in the
+computation. On the other hand, the conditions for nucleation depend only on
+the properties of the large stable grains and are more robust. We finally point
+out that this mechanism may be relevant in the early universe as an initial
+dust pollution mechanism, since once the interstellar medium is polluted with
+dust, mantle growth is likely to be dominant over non-LTE nucleation in the
+diffuse medium.",0710.2903v2
+2008-01-30,The zero-energy Landau levels in graphene as BPS-saturated states,"This paper has been withdrawn by the author, due to the crucial mistake of
+the discussion in Sec IV.",0801.4785v2
+2008-02-25,Delay Analysis for Wireless Local Area Networks with Multipacket Reception under Finite Load,"To date, most analysis of WLANs has been focused on their operation under
+saturation condition. This work is an attempt to understand the fundamental
+performance of WLANs under unsaturated condition. In particular, we are
+interested in the delay performance when collisions of packets are resolved by
+an exponential backoff mechanism. Using a multiple-vacation queueing model, we
+derive an explicit expression for packet delay distribution, from which
+necessary conditions for finite mean delay and delay jitter are established. It
+is found that under some circumstances, mean delay and delay jitter may
+approach infinity even when the traffic load is way below the saturation
+throughput. Saturation throughput is therefore not a sound measure of WLAN
+capacity when the underlying applications are delay sensitive. To bridge the
+gap, we define safe-bounded-mean-delay (SBMD) throughput and
+safe-bounded-delay-jitter (SBDJ) throughput that reflect the actual network
+capacity users can enjoy when they require bounded mean delay and delay jitter,
+respectively. The analytical model in this paper is general enough to cover
+both single-packet reception (SPR) and multi-packet reception (MPR) WLANs, as
+well as carrier-sensing and non-carrier-sensing networks. We show that the SBMD
+and SBDJ throughputs scale super-linearly with the MPR capability of a network.
+Together with our earlier work that proves super-linear throughput scaling
+under saturation condition, our results here complete the demonstration of MPR
+as a powerful capacity-enhancement technique for both delay-sensitive and
+delay-tolerant applications.",0802.3569v1
+2008-09-16,A Rational Approach to the Resonance Region,"Resonance Saturation in QCD can be understood in the large-Nc limit from the
+mathematical theory of Pade Approximants to meromorphic functions.",0809.2704v1
+2008-09-24,Simplified PMT Model,"A simplified model is proposed based on the characteristics of the
+photomultiplier tube (PMT). The Model is compared to the available data, and it
+successes to reproduce the saturation profile of the PMT. The model also adds
+clarification about how the PMT works.",0809.4210v1
+2008-12-11,Diffractive physics in ALICE,"The ALICE experiment at the LHC is presented and a diffractive double gap
+trigger is described. Signatures of Pomeron and Odderon are discussed together
+with photoproduction of heavy quarks as a possible signature of gluon
+saturation.",0812.2176v1
+2009-01-08,Computing Inhomogeneous Groebner Bases,"In this paper we describe how an idea centered on the concept of
+self-saturation allows several improvements in the computation of Groebner
+bases via Buchberger's Algorithm.",0901.1105v1
+2009-03-04,Aggregation According to Classical Kinetics--From Nucleation to Coarsening,"We solve the standard Lifshitz-Slyozov (LS) model with conservation of total
+particles in the limit of small super-saturation. The new element is an
+effective initial condition that follows from the initial exhaustion of
+nucleation as described in a previous paper [Farjoun and Neu, Phys. Rev. E 78].
+The effective initial condition is characterized by a narrow distribution of
+cluster-sizes, all much larger than critical. In the subsequent solution, one
+of the LS similarity solutions emerges as the long-time limit, as expected. But
+our solution tells more. In particular, there is a ""growth"" era prior to what
+is usually called ""coarsening"". During ""growth"" the clusters (all of nearly the
+same size much larger than critical) eventually exhaust the super-saturation
+(the exhaustion of nucleation in the previous era results from only a small
+decrease in super-saturation). This allows the critical size to catch up to the
+clusters, and the traditional ""coarsening"" begins: Subcritical clusters
+dissolve and fuel the growth of the remaining super-critical clusters. Our
+analysis tracks the evolution of cluster sizes during growth and coarsening by
+complimentary use of asymptotic and numerical methods. We establish
+characteristic times and cluster sizes associated with growth and coarsening
+from physical parameters and the initial super-saturation. The emerging
+distribution is discontinuous at the largest cluster size, and our model
+selects the discontinuous LS similarity solution as the long time limit. There
+are strong indications that the smooth similarity solution proposed in the
+original LS paper emerges on a, yet longer, late-coarsening time-scale.",0903.0861v1
+2009-03-13,Resonance saturation of the chiral couplings at NLO in 1/Nc,"The precision obtainable in phenomenological applications of Chiral
+Perturbation Theory is currently limited by our lack of knowledge on the
+low-energy constants (LECs). The assumption that the most important
+contributions to the LECs come from the dynamics of the low-lying resonances,
+often referred to as the resonance saturation hypothesis, has stimulated the
+use of large-Nc resonance lagrangians in order to obtain explicit values for
+the LECs. We study the validity of the resonance saturation assumption at the
+next-to-leading order in the 1/Nc expansion within the framework of Resonance
+Chiral Theory (RChT). We find that, by imposing QCD short-distance constraints,
+the chiral couplings can be written in terms of the resonance masses and
+couplings and do not depend explicitly on the coefficients of the chiral
+operators in the Goldstone boson sector of RChT. As we argue, this is the
+counterpart formulation of the resonance saturation statement in the context of
+the resonance lagrangian. Going beyond leading order in the 1/Nc counting allow
+us to keep full control of the renormalization scale dependence of the LEC
+estimates.",0903.2440v2
+2009-04-28,"Comment on ""An optimized potential for carbon dioxide""","A molecular model for carbon dioxide is assessed regarding vapor-liquid
+equilibrium properties. Large deviations, being above 15 %, are found for vapor
+pressure and saturated vapor density in the entire temperature range.",0904.4391v1
+2009-07-08,On the theory of astronomical maser. I. Statistics of maser radiation,"In this paper we re-analyse the amplification process of broadband continuum
+radiation by astronomical masers in one-dimensional case. The basic equations
+appropriate for the scalar maser and the random nature of the maser radiation
+field are derived from basic physical principles. Comparision with the standard
+radiation transfer equation allows us to examine the underlying assumptions
+involved in the current theory of astronomical masers. Simulations are carried
+out to follow the amplification of different realisations of the broadband
+background radiation by the maser. The observable quantities such as intensity,
+spectral line profile are obtained by averaging over an ensemble of the
+emerging radiation corresponding to the amplified background radiation field.
+Our simulations show that the fluctuations of the radiation field inside the
+astronomical maser deviates significantly from Gaussian statistics even when
+the maser is only partially saturated. Coupling between different frequency
+modes and the population pulsing are shown to have increasing importance in the
+transport of maser radiation as the maser approaches saturation. Our results
+suggest that the standard formulation of radiation transfer provides a
+satisfactory description of the intensity and the line narrowing effect in the
+unsaturated and partially saturated masers within the framework of
+one-dimensional model. Howerver, the application of the same formulation to the
+strong saturation regime should be considered with caution.",0907.1326v1
+2009-09-22,Experimental study on the cyclic resistance of a natural loess from Northern France,"In order to analyze the instability phenomenon observed along the Northern
+High Speed Line of R\'eseau Ferr\'e de France (RFF), soil blocks were taken at
+a site near the railway, at four different depths (1.2, 2.2, 3.5 and 4.9 m).
+Cyclic triaxial tests were carried out on saturated and unsaturated soil
+specimens. The results from tests on initially saturated specimens showed that
+the soil taken at 2.2 m depth has the lowest resistance to cyclic loading, in
+relation to its highest porosity and lowest clay fraction. This soil was then
+studied at unsaturated state with various initial water contents. Unsaturated
+soil specimens were first subjected to cyclic loadings to decrease their
+volume. These cyclic loadings was stopped when the volume decrease was
+approximately equal to the initial pore air volume, or when the pores filled by
+air were eliminated and the soil was considered to become saturated.
+Afterwards, the back-pressure tubing was saturated with de-aired water and
+cycles were applied under undrained condition. Significant effect of initial
+water content was evidenced: the lower the initial water content, the higher
+the cyclic resistance. This can be explained by the densification of the soil
+during the initial cyclic loadings.",0909.3932v1
+2009-10-20,The saturation of SASI by parasitic instabilities,"The Standing Accretion Shock Instability (SASI) is commonly believed to be
+responsible for large amplitude dipolar oscillations of the stalled shock
+during core collapse, potentially leading to an asymmetric supernovae
+explosion. The degree of asymmetry depends on the amplitude of SASI, which
+nonlinear saturation mechanism has never been elucidated. We investigate the
+role of parasitic instabilities as a possible cause of nonlinear SASI
+saturation. As the shock oscillations create both vorticity and entropy
+gradients, we show that both Kelvin-Helmholtz and Rayleigh-Taylor types of
+instabilities are able to grow on a SASI mode if its amplitude is large enough.
+We obtain simple estimates of their growth rates, taking into account the
+effects of advection and entropy stratification. In the context of the
+advective-acoustic cycle, we use numerical simulations to demonstrate how the
+acoustic feedback can be decreased if a parasitic instability distorts the
+advected structure. The amplitude of the shock deformation is estimated
+analytically in this scenario. When applied to the set up of Fernandez &
+Thompson (2009a), this saturation mechanism is able to explain the dramatic
+decrease of the SASI power when both the nuclear dissociation energy and the
+cooling rate are varied. Our results open new perspectives for anticipating the
+effect, on the SASI amplitude, of the physical ingredients involved in the
+modeling of the collapsing star.",0910.3953v2
+2009-11-15,Onset of Instability in Restricted Geometry 4He Film Flow,"An early study of saturated 4He film flow instability is revisited in view of
+recent theoretical work by Hiromitsu Takeuchi et al. (arXiv:0909.2144v1
+[cond-mat.quant-gas] Sept. 2009). I show additional data that suggests a
+qualitative agreement with this theory and discuss the experimental details.",0911.2820v1
+2009-11-17,Incompressibility of asymmetric nuclear matter,"The incompressibility $K_sat(\delta)$ of isospin asymmetric nuclear matter at
+its saturation density. Our results show that in the expansion of
+$K_sat(\delta)$ in powers of isospin asymmetry $\delta$, i.e., $K_sat(\delta
+)$=K_{0}+K_{sat,2}\delta^{2}+K_{sat,4}\delta^{4}+O(\delta^{6})$, the magnitude
+of the 4th-order K_{sat,4} parameter is generally small. The 2nd-order
+K_{sat,2} parameter thus essentially characterizes the isospin dependence of
+the incompressibility of asymmetric nuclear matter at saturation density.
+Furthermore, the K_{sat,2} can be expressed as
+K_{sat,2}=K_{sym}-6L-J_{0}/{K_{0}L in terms of the slope parameter $L$ and the
+curvature parameter $K_{\mathrm{sym}}$ of the symmetry energy and the
+third-order derivative parameter $J_0$ of the energy of symmetric nuclear
+matter at saturation density, and we find the higher order $J_0$ contribution
+to K_{sat,2} generally cannot be neglected. Also, we have found a linear
+correlation between K_{sym} and $L$ as well as between $J_{0}/K_{0}$ and
+$K_{0}$. Using these correlations together with the empirical constraints on
+$K_{0}$ and $L$, the nuclear symmetry energy $E_sym(\rho_{0})$ at normal
+nuclear density, and the nucleon effective mass, we have obtained an estimated
+value of K_{sat,2}=-370 +- 120 MeV for the 2nd-order parameter in the isospin
+asymmetry expansion of the incompressibility of asymmetric nuclear matter at
+its saturation density.",0911.3330v1
+2009-12-09,Mixed scenario of the charged helium surface reconstruction,"Discussed in the paper is the mixed scenario of charged liquid surface
+reconstruction when the surface 2D charge density is close to the saturation.
+The basic building block of arising honeycomb structure is shown to be a
+modified multielectron dimple.",0912.1691v1
+2010-05-11,Unitarity: confinement and collective effects in hadron interactions,"We discuss how saturation of unitarity would change phase structure of
+hadronic matter at very high temperatures emphasizing the role of the vacuum
+state with spontaneously broken chiral symmetry.",1005.1731v1
+2010-09-09,Saturated torque formula for planetary migration in viscous disks with thermal diffusion: recipe for protoplanet population synthesis,"We provide torque formulae for low mass planets undergoing type I migration
+in gaseous disks. These torque formulae put special emphasis on the horseshoe
+drag, which is prone to saturation: the asymptotic value reached by the
+horseshoe drag depends on a balance between coorbital dynamics (which tends to
+cancel out or saturate the torque) and diffusive processes (which tend to
+restore the unperturbed disk profiles, thereby desaturating the torque). We
+entertain here the question of this asymptotic value, and we derive torque
+formulae which give the total torque as a function of the disk's viscosity and
+thermal diffusivity. The horseshoe drag features two components: one which
+scales with the vortensity gradient, and one which scales with the entropy
+gradient, and which constitutes the most promising candidate for halting inward
+type I migration. Our analysis, which is complemented by numerical simulations,
+recovers characteristics already noted by numericists, namely that the viscous
+timescale across the horseshoe region must be shorter than the libration time
+in order to avoid saturation, and that, provided this condition is satisfied,
+the entropy related part of the horseshoe drag remains large if the thermal
+timescale is shorter than the libration time. Side results include a study of
+the Lindblad torque as a function of thermal diffusivity, and a contribution to
+the corotation torque arising from vortensity viscously created at the contact
+discontinuities that appear at the horseshoe separatrices. For the convenience
+of the reader mostly interested in the torque formulae, section 8 is
+self-contained.",1009.1913v2
+2010-10-21,State Dependent Attempt Rate Modeling of Single Cell IEEE~802.11 WLANs with Homogeneous Nodes and Poisson Packet Arrivals,"Analytical models for IEEE 802.11-based WLANs are invariably based on
+approximations, such as the well-known \textit{decoupling approximation}
+proposed by Bianchi for modeling single cell WLANs consisting of saturated
+nodes. In this paper, we provide a new approach to model the situation when the
+nodes are not saturated. We study a State Dependent Attempt Rate (SDAR)
+approximation to model $M$ queues (one queue per node) served by the CSMA/CA
+protocol as standardized in the IEEE 802.11 DCF MAC protocol. The approximation
+is that, when $n$ of the $M$ queues are non-empty, the transmission attempt
+probability of the $n$ non-empty nodes is given by the long-term transmission
+attempt probability of $n$ ""saturated"" nodes as provided by Bianchi's model.
+The SDAR approximation reduces a single cell WLAN with non-saturated nodes to a
+""coupled queue system"". When packets arrive to the $M$ queues according to
+independent Poisson processes, we provide a Markov model for the coupled queue
+system with SDAR service. \textit{The main contribution of this paper is to
+provide an analysis of the coupled queue process by studying a lower
+dimensional process, and by introducing a certain conditional independence
+approximation}. We show that the SDAR model of contention provides an accurate
+model for the DCF MAC protocol in single cells, and report the simulation
+speed-ups thus obtained by our \textit{model-based simulation}.",1010.4475v1
+2010-12-02,Equality Saturation: A New Approach to Optimization,"Optimizations in a traditional compiler are applied sequentially, with each
+optimization destructively modifying the program to produce a transformed
+program that is then passed to the next optimization. We present a new approach
+for structuring the optimization phase of a compiler. In our approach,
+optimizations take the form of equality analyses that add equality information
+to a common intermediate representation. The optimizer works by repeatedly
+applying these analyses to infer equivalences between program fragments, thus
+saturating the intermediate representation with equalities. Once saturated, the
+intermediate representation encodes multiple optimized versions of the input
+program. At this point, a profitability heuristic picks the final optimized
+program from the various programs represented in the saturated representation.
+Our proposed way of structuring optimizers has a variety of benefits over
+previous approaches: our approach obviates the need to worry about optimization
+ordering, enables the use of a global optimization heuristic that selects among
+fully optimized programs, and can be used to perform translation validation,
+even on compilers other than our own. We present our approach, formalize it,
+and describe our choice of intermediate representation. We also present
+experimental results showing that our approach is practical in terms of time
+and space overhead, is effective at discovering intricate optimization
+opportunities, and is effective at performing translation validation for a
+realistic optimizer.",1012.1802v3
+2011-03-15,Can a Bose gas be saturated?,"Bose-Einstein condensation is unique among phase transitions between
+different states of matter in the sense that it occurs even in the absence of
+interactions between particles. In Einstein's textbook picture of an ideal gas,
+purely statistical arguments set an upper bound on the number of particles
+occupying the excited states of the system, and condensation is driven by this
+saturation of the quantum vapour. Dilute ultracold atomic gases are celebrated
+as a realisation of Bose-Einstein condensation in close to its purely
+statistical form. Here we scrutinise this point of view using an ultracold gas
+of potassium (39K) atoms, in which the strength of interactions can be tuned
+via a Feshbach scattering resonance. We first show that under typical
+experi-mental conditions a partially condensed atomic gas strongly deviates
+from the textbook concept of a saturated vapour. We then use measurements at a
+range of interaction strengths and temperatures to extrapolate to the
+non-interacting limit, and prove that in this limit the behaviour of a Bose gas
+is consistent with the saturation picture. Finally, we provide evidence for the
+universality of our observations through additional measurements with a
+different atomic species, 87Rb. Our results suggest a new way of characterising
+condensation phenomena in different physical systems.",1103.2896v1
+2011-03-30,Homology decompositions and groups inducing fusion systems,"We relate the construction of groups which realize saturated fusion systems
+and signaliser functors with homology decompositions of p-local finite groups.
+We prove that the cohomology ring of Robinson's construction is in some precise
+sense very close to the cohomology ring of the fusion system it realizes.",1103.5856v1
+2011-03-30,On Two Models of the Light Pulse Delay in a Saturable Absorber,"A comparative analysis of two approaches to description of the light
+modulation pulse delay in a saturable absorber is presented. According to the
+simplest model, the delay of the optical pulse is a result of distortion of its
+shape due to absorption self-modulation in the nonlinear medium. The second
+model of the effect, proposed at the beginning of our century, connects the
+pulse delay with the so-called ""slow light"" resulting from the group velocity
+reduction under conditions of the coherent population oscillations. It is shown
+that all the known experimental data on the light pulse delay in saturable
+absorbers can be comprehensively described in the framework of the simplest
+model of saturable absorber and do not require invoking the effect of coherent
+population oscillations with spectral hole-burning and anomalous modifications
+of the light group velocity. It is concluded that the effect of group velocity
+reduction under conditions of coherent population oscillations has not received
+so far any experimental confirmation, and the assertions about real observation
+of the ""slow light"" based on this mechanism are groundless.",1103.5868v1
+2011-12-06,Analogues of Goldschmidt's thesis for fusion systems,"We extend the results of David Goldschmidt's thesis concerning fusion in
+finite groups to saturated fusion systems and to all primes.",1112.1389v1
+2011-12-13,The color dipole picture of low-x DIS,"Deep inelastic electron scattering (DIS) from nucleons at low values of the
+Bjorken variable $x \cong Q^2/W^2 \lsim ~ 0.1$ proceeds via fluctuations of the
+photon into quark-antiquark dipole states that subsequently interact with the
+gluon field in the nucleon. Dependent on the interaction energy, $W$, the
+color-gauge-invariant dipole interaction with the gluon field in the nucleon,
+for any fixed dipole size, contains the limits of i) color transparency and ii)
+saturation, where ""saturation"" stands for the approach to a hadronlike
+dipole-proton interaction cross section. All essential features of the
+experimental results on low-x DIS, as a consequence of the
+color-gauge-invariant dipole interaction follow model independently i.e.
+without specific ansatz for the dipole cross section. The model-independent
+results in particular include the low-x scaling behavior of the photoabsorption
+cross section, $\sigma_{\gamma^*p} (W^2,Q^2) = \sigma_{\gamma^*p} (\eta
+(W^2,Q^2))$, with definite functional dependence on the low-x scaling variable
+$\eta (W^2,Q^2) \cong Q^2/\Lambda^2_{sat} (W^2)$ in the limits of $\eta
+(W^2,Q^2) \gg 1$ and $\eta (W^2,Q^2) \ll 1$, respectively. Consistency with the
+pQCD-improved parton model implies the definite value of $C_2 \cong 0.29$ for
+the exponent in the ""saturation scale"", $\Lambda^2_{sat} (W^2) \approx
+(W^2)^{C_2}$. The longitudinal-to-transverse ratio of the photoabsorption cross
+section at large $Q^2$ has the definite value of $R = 1/2 \rho$ with $\rho =
+4/3$. For $W^2 \to \infty$ at any fixed $Q^2$, the photoabsorption cross
+section converges towards a $Q^2$-independent saturation limit that coincides
+with the cross section for $Q^2 = 0$ photoproduction.",1112.2885v1
+2012-02-13,The Maximal Runaway Temperature of Earth-like Planets,"We generalize the problem of the semi-gray model to cases in which a
+non-negligible fraction of the stellar radiation falls on the long-wavelength
+range, and/or that the planetary long-wavelength emission penetrates into the
+transparent short wavelength domain of the absorption.
+  Second, applying the most general assumptions and independently of any
+particular properties of an absorber, we show that the greenhouse effect
+saturates and any Earth-like planet has a maximal temperature which depends on
+the type of and distance to its main-sequence star, its albedo and the primary
+atmospheric components which determine the cutoff frequency below which the
+atmosphere is optically thick. For example, a hypothetical convection-less
+planet similar to Venus, that is optically thin in the visible, could have at
+most a surface temperature of 1200-1300K irrespective of the nature of the
+greenhouse gas.
+  We show that two primary mechanisms are responsible for the saturation of the
+runaway greenhouse effect, depending on the value of the wavelength above which
+the atmosphere becomes optically thick. Unless this wavelength is small and
+resides in the optical region, saturation is achieved by radiating the thermal
+flux of the planet through the short wavelength tail of the thermal
+distribution. This has the observational implication, the radiation from such a
+planet should be skewed towards the NIR. Otherwise, saturation takes place by
+radiating through windows in the FIR.",1202.2644v1
+2012-03-22,A 1-D modelling of streaming potential dependence on water content during drainage experiment in sand,"The understanding of electrokinetics for unsaturated conditions is crucial
+for numerous of geophysical data interpretation. Nevertheless, the behaviour of
+the streaming potential coefficient C as a function of the water saturation Sw
+is still discussed. We propose here to model both the Richards' equation for
+hydrodynamics and the Poisson's equation for electrical potential for
+unsaturated conditions using 1-D finite element method. The equations are first
+presented and the numerical scheme is then detailed for the Poisson's equation.
+Then, computed streaming potentials (SPs) are compared to recently published SP
+measurements carried out during drainage experiment in a sand column. We show
+that the apparent measurement of DV / DP for the dipoles can provide the SP
+coefficient in these conditions. Two tests have been performed using existing
+models for the SP coefficient and a third one using a new relation. The results
+show that existing models of unsaturated SP coefficients C(Sw) provide poor
+results in terms of SP magnitude and behaviour. We demonstrate that the
+unsaturated SP coefficient can be until one order of magnitude larger than
+Csat, its value at saturation. We finally prove that the SP coefficient follows
+a non-monotonous behaviour with respect to water saturation. Key words:
+Electrical properties; Electromagnetic theory; Hydrogeophysics; Hydrology;
+Permeability and porosity; electrokinetic; streaming potential; self-potential;
+water content; water saturation; unsaturated condition; finite element modeling",1203.4921v1
+2012-08-13,Model-theoretic properties of ultrafilters built by independent families of functions,"Our results in this paper increase the model-theoretic precision of a widely
+used method for building ultrafilters, and so advance the general problem of
+constructing ultrafilters whose ultrapowers have a precise degree of
+saturation. We begin by showing that any flexible regular ultrafilter makes the
+product of an unbounded sequence of finite cardinals large, {thus} saturating
+any stable theory. We then prove directly that a ""bottleneck"" in the inductive
+construction of a regular ultrafilter on $\lambda$ (i.e. a point after which
+all antichains of $P(\lambda)/D$ have cardinality less than $\lambda$)
+essentially prevents any subsequent ultrafilter from being flexible, {thus}
+from saturating any non-low theory. The paper's three main constructions are as
+follows. First, we construct a regular filter $D$ on $\lambda$ so that any
+ultrafilter extending $D$ fails to $\lambda^+$-saturate ultrapowers of the
+random graph, {thus} of any unstable theory. The proof constructs the omitted
+random graph type directly. Second, assuming existence of a measurable cardinal
+$\kappa$, we construct a regular ultrafilter on $\lambda > \kappa$ which is
+$\lambda$-flexible but not $\kappa^{++}$-good, improving our previous answer to
+a question raised in Dow 1975. Third, assuming a weakly compact cardinal
+$\kappa$, we construct an ultrafilter to show that $\lcf(\aleph_0)$ may be
+small while all symmetric cuts of cofinality $\kappa$ are realized. Thus
+certain families of pre-cuts may be realized while still failing to saturate
+any unstable theory.",1208.2579v1
+2012-08-30,Delineating the saturation boundary: linear vs non-linear QCD evolution from HERA data to LHC phenomenology,"The forthcoming p+Pb run at the LHC will provide crucial in formation on the
+initial state effects of heavy ion collisions and on the gluon saturation
+phenomena. In turn, most of the saturation inspired phenomenology in heavy ion
+collisions borrows substantial empiric information from the analysis of e+p
+data, where abundant high quality data on the small-x kinematic region is
+available. Indeed, the very precise combined HERA data provides a testing
+ground in which the relevance of novel QCD regimes, other than the successful
+linear DGLAP evolution, in small-x inclusive DIS data can be ascertained. We
+present a study of the dependence of the AAMQS fits, based on the running
+coupling BK non-linear evolution equations (rcBK), on the fitted dataset. This
+allows for the identification of the kinematical region where rcBK accurately
+describes the data, and thus for the determination of its applicability
+boundary. It also set important constraints to the saturation models used to
+model the early stages of heavy ion collisions. Finally we compare the rcBK
+results with NNLO DGLAP fits, obtained with the NNPDF methodology with
+analogous kinematical cuts. Further, we explore the impact on LHC phenomenology
+of applying stringent kinematical cuts to the low-x HERA data in a DGLAP fit.",1208.6246v1
+2012-10-23,Gravitational wave emission and spindown of young pulsars,"The rotation frequencies of young pulsars are systematically below their
+theoretical Kepler limit. R-modes have been suggested as a possible explanation
+for this observation. With the help of semi-analytic expressions that make it
+possible to assess the uncertainties of the r-mode scenario due to the impact
+of uncertainties in underlying microphysics, we perform a quantitative analysis
+of the spin-down and the emitted gravitational waves of young pulsars. We find
+that the frequency to which r-modes spin down a young neutron star is
+surprisingly insensitive both to the microscopic details and the saturation
+amplitude. Comparing our result to astrophysical data, we show that for a range
+of sufficiently large saturation amplitudes r-modes provide a viable spindown
+scenario and that all observed young pulsars are very likely already outside
+the r-mode instability region. Therefore the most promising sources for
+gravitational wave detection are unobserved neutron stars associated with
+recent supernovae, and we find that advanced LIGO should be able to see several
+of them. We find the remarkable result that the gravitational wave strain
+amplitude is completely independent of both the r-mode saturation amplitude and
+the microphysics, and depends on the saturation mechanism only within some tens
+of per cent. However, the gravitational wave frequency depends on the amplitude
+and we provide the required expected timing parameter ranges to look for
+promising sources in future searches.",1210.6091v2
+2013-05-25,Gluon splitting in a shockwave,"The study of azimuthal correlations in particle production at forward
+rapidities in proton-nucleus collisions provides direct information about high
+gluon density effects, like gluon saturation, in the nuclear wavefunction. In
+the kinematical conditions for proton-lead collisions at the LHC, the forward
+di-hadron production is dominated by partonic processes in which a gluon from
+the proton splits into a pair of gluons, while undergoing multiple scattering
+off the dense gluon system in the nucleus. We compute the corresponding
+cross-section using the Colour Glass Condensate effective theory, which enables
+us to include the effects of multiple scattering and gluon saturation in the
+leading logarithmic approximation at high energy. This opens the way towards
+systematic studies of angular correlations in two-gluon production, similar to
+previous studies for quark-gluon production in the literature. We consider in
+more detail two special kinematical limits: the ""back-to-back correlation
+limit"", where the transverse momenta of the produced gluons are much larger
+than the nuclear saturation momentum, and the ""double parton scattering limit"",
+where the two gluons are produced by a nearly collinear splitting occurring
+prior to the collision. We argue that saturation effects remain important even
+for relatively high transverse momenta (i.e. for nearly back-to-back
+configurations), leading to geometric scaling in the azimuthal distribution.",1305.5926v1
+2013-05-29,Resolution-aware network coded storage,"In this paper, we show that coding can be used in storage area networks
+(SANs) to improve various quality of service metrics under normal SAN operating
+conditions, without requiring additional storage space. For our analysis, we
+develop a model which captures modern characteristics such as constrained I/O
+access bandwidth limitations. Using this model, we consider two important
+cases: single-resolution (SR) and multi-resolution (MR) systems. For SR
+systems, we use blocking probability as the quality of service metric and
+propose the network coded storage (NCS) scheme as a way to reduce blocking
+probability. The NCS scheme codes across file chunks in time, exploiting file
+striping and file duplication. Under our assumptions, we illustrate cases where
+SR NCS provides an order of magnitude savings in blocking probability. For MR
+systems, we introduce saturation probability as a quality of service metric to
+manage multiple user types, and we propose the uncoded resolution- aware
+storage (URS) and coded resolution-aware storage (CRS) schemes as ways to
+reduce saturation probability. In MR URS, we align our MR layout strategy with
+traffic requirements. In MR CRS, we code videos across MR layers. Under our
+assumptions, we illustrate that URS can in some cases provide an order of
+magnitude gain in saturation probability over classic non-resolution aware
+systems. Further, we illustrate that CRS provides additional saturation
+probability savings over URS.",1305.6864v1
+2013-06-19,CSMA/ECA in Non-Saturation,"During the past month we have been trying to understand both the behavior of
+CSMA/ECA and how our simulator works. In this report I try to asses some of
+those doubts and provide a groundwork for discussion of past and new ideas for
+further develop the MAC protocol.",1306.4542v1
+2013-09-02,Infrared Saturation and Phases of Gauge Theories with BRST Symmetry,"We investigate the infrared limit of the quantum equation of motion of the
+gauge boson propagator in various gauges and models with a BRST symmetry. We
+find that the saturation of this equation at low momenta distinguishes between
+the Coulomb, Higgs and confining phase of the gauge theory. The Coulomb phase
+is characterized by a massless gauge boson. Physical states contribute to the
+saturation of the transverse equation of motion of the gauge boson at low
+momenta in the Higgs phase, while the saturation is entirely due to unphysical
+degrees of freedom in the confining phase. This corollary to the Kugo-Ojima
+confinement criterion in linear covariant gauges also is sufficient for
+confinement in general covariant gauges with BRST- and anti-BRST symmetry,
+maximal Abelian gauges with an equivariant BRST symmetry, non-covariant Coulomb
+gauge and in the Gribov-Zwanziger theory.",1309.0497v3
+2013-09-29,Threshold Saturation for Spatially-Coupled LDPC and LDGM Codes on BMS Channels,"Spatially-coupled low-density parity-check (LDPC) codes, which were first
+introduced as LDPC convolutional codes, have been shown to exhibit excellent
+performance under low-complexity belief-propagation decoding. This phenomenon
+is now termed threshold saturation via spatial coupling. Spatially-coupled
+codes have been successfully applied in numerous areas. In particular, it was
+proven that spatially-coupled regular LDPC codes universally achieve capacity
+over the class of binary memoryless symmetric (BMS) channels under
+belief-propagation decoding.
+  Recently, potential functions have been used to simplify threshold saturation
+proofs for scalar and vector recursions. In this paper, potential functions are
+used to prove threshold saturation for irregular LDPC and low-density
+generator-matrix (LDGM) codes on BMS channels, extending the simplified proof
+technique to BMS channels. The corresponding potential functions are closely
+related to the average Bethe free entropy of the ensembles in the large-system
+limit. These functions also appear in statistical physics when the replica
+method is used to analyze optimal decoding.",1309.7543v2
+2013-09-30,A Simple Proof of Maxwell Saturation for Coupled Scalar Recursions,"Low-density parity-check (LDPC) convolutional codes (or spatially-coupled
+codes) were recently shown to approach capacity on the binary erasure channel
+(BEC) and binary-input memoryless symmetric channels. The mechanism behind this
+spectacular performance is now called threshold saturation via spatial
+coupling. This new phenomenon is characterized by the belief-propagation
+threshold of the spatially-coupled ensemble increasing to an intrinsic noise
+threshold defined by the uncoupled system. In this paper, we present a simple
+proof of threshold saturation that applies to a wide class of coupled scalar
+recursions. Our approach is based on constructing potential functions for both
+the coupled and uncoupled recursions. Our results actually show that the fixed
+point of the coupled recursion is essentially determined by the minimum of the
+uncoupled potential function and we refer to this phenomenon as Maxwell
+saturation. A variety of examples are considered including the
+density-evolution equations for: irregular LDPC codes on the BEC, irregular
+low-density generator matrix codes on the BEC, a class of generalized LDPC
+codes with BCH component codes, the joint iterative decoding of LDPC codes on
+intersymbol-interference channels with erasure noise, and the compressed
+sensing of random vectors with i.i.d. components.",1309.7910v3
+2014-04-05,Induced cooperative motions in a medium driven at the nanoscale: Searching for an optimum excitation period,"Recent results have shown the appearance of induced cooperative motions
+called dynamic heterogeneity during the isomerization of diluted azobenzene
+molecules in a host glass-former. In this paper we raise the issue of the
+coupling between these ""artificial"" heterogeneities and the isomerization
+period. How do these induced heterogeneities differ in the saturation regime
+and in the linear response regime ? Is there a maximum of the heterogeneous
+motion versus isomerization rate and why ? Are the heterogeneity evolution with
+the isomerization rate connected with the diffusion or relaxation time
+evolution ? We use out of equilibrium molecular dynamics simulations to answer
+these questions. We find that the heterogeneity increases in the linear
+response regime for large isomerization periods and small perturbations. In
+contrast the heterogeneity decreases in the saturation regime, i.e. when the
+isomerization half-period ($\tau_{p}/2$) is smaller than the relaxation time of
+the material ($\tau_{\alpha}$). This result makes possible a test of the effect
+of cooperative motions on the dynamics using the chromophores as Maxwell demons
+that destroy or stimulate the cooperative motions. Because the heterogeneities
+increase in the linear regime and then decrease in the saturation regime, we
+find a maximum for $\tau_{p}/2 \approx \tau_{\alpha}$. The induced excitations
+concentration follows a power law evolution versus the isomerization rate and
+then saturates. As a consequence the $\alpha$ relaxation time is related to the
+excitation concentration with a power law, a result in qualitative agreement
+with recent findings in constrained models. This result supports a common
+origin for the heterogeneities with constrained models and a similar relation
+to the excitation concentration.",1404.1452v1
+2014-05-19,Charge-induced phase separation in lipid membranes,"The phase separation in lipid bilayers that include negatively charged lipids
+is examined experimentally. We observed phase-separated structures and
+determined the membrane miscibility temperatures in several binary and ternary
+lipid mixtures of unsaturated neutral lipid, dioleoylphosphatidylcholine
+(DOPC), saturated neutral lipid, dipalmitoylphosphatidylcholine (DPPC),
+unsaturated charged lipid, dioleoylphosphatidylglycerol
+(DOPG$^{\scriptsize{(-)}}$), saturated charged lipid,
+dipalmitoylphosphatidylglycerol (DPPG$^{\scriptsize{(-)}}$), and cholesterol.
+In binary mixtures of saturated and unsaturated charged lipids, the combination
+of the charged head with the saturation of hydrocarbon tail is a dominant
+factor for the stability of membrane phase separation.
+DPPG$^{\scriptsize{(-)}}$ enhances phase separation, while
+DOPG$^{\scriptsize{(-)}}$ suppresses it. Furthermore, the addition of
+DPPG$^{\scriptsize{(-)}}$ to a binary mixture of DPPC/cholesterol induces phase
+separation between DPPG$^{\scriptsize{(-)}}$-rich and cholesterol-rich phases.
+This indicates that cholesterol localization depends strongly on the electric
+charge on the hydrophilic head group rather than on the ordering of the
+hydrocarbon tails. Finally, when DPPG$^{\scriptsize{(-)}}$ was added to a
+neutral ternary system of DOPC/DPPC/Cholesterol (a conventional model of
+membrane rafts), a three-phase coexistence was produced. We conclude by
+discussing some qualitative features of the phase behaviour in charged
+membranes using a free energy approach.",1405.4650v3
+2014-06-09,On saturation games,"A graph $G = (V,E)$ is said to be saturated with respect to a monotone
+increasing graph property ${\mathcal P}$, if $G \notin {\mathcal P}$ but $G
+\cup \{e\} \in {\mathcal P}$ for every $e \in \binom{V}{2} \setminus E$. The
+saturation game $(n, {\mathcal P})$ is played as follows. Two players, called
+Mini and Max, progressively build a graph $G \subseteq K_n$, which does not
+satisfy ${\mathcal P}$. Starting with the empty graph on $n$ vertices, the two
+players take turns adding edges $e \in \binom{V(K_n)}{2} \setminus E(G)$, for
+which $G \cup \{e\} \notin {\mathcal P}$, until no such edge exists (i.e. until
+$G$ becomes ${\mathcal P}$-saturated), at which point the game is over. Max's
+goal is to maximize the length of the game, whereas Mini aims to minimize it.
+The score of the game, denoted by $s(n, {\mathcal P})$, is the number of edges
+in $G$ at the end of the game, assuming both players follow their optimal
+strategies. We prove lower and upper bounds on the score of games in which the
+property the players need to avoid is being $k$-connected, having chromatic
+number at least $k$, and admitting a matching of a given size. In doing so we
+demonstrate that the score of certain games can be as large as the Tur\'an
+number or as low as the saturation number of the respective graph property. We
+also demonstrate that the score might strongly depend on the identity of the
+first player to move.",1406.2111v3
+2014-08-23,Saturation in the Hypercube and Bootstrap Percolation,"Let $Q_d$ denote the hypercube of dimension $d$. Given $d\geq m$, a spanning
+subgraph $G$ of $Q_d$ is said to be $(Q_d,Q_m)$-saturated if it does not
+contain $Q_m$ as a subgraph but adding any edge of $E(Q_d)\setminus E(G)$
+creates a copy of $Q_m$ in $G$. Answering a question of Johnson and Pinto, we
+show that for every fixed $m\geq2$ the minimum number of edges in a
+$(Q_d,Q_m)$-saturated graph is $\Theta(2^d)$.
+  We also study weak saturation, which is a form of bootstrap percolation. A
+spanning subgraph of $Q_d$ is said to be weakly $(Q_d,Q_m)$-saturated if the
+edges of $E(Q_d)\setminus E(G)$ can be added to $G$ one at a time so that each
+added edge creates a new copy of $Q_m$. Answering another question of Johnson
+and Pinto, we determine the minimum number of edges in a weakly
+$(Q_d,Q_m)$-saturated graph for all $d\geq m\geq1$. More generally, we
+determine the minimum number of edges in a subgraph of the $d$-dimensional grid
+$P_k^d$ which is weakly saturated with respect to `axis aligned' copies of a
+smaller grid $P_r^m$. We also study weak saturation of cycles in the grid.",1408.5488v2
+2014-08-29,The saturation of Frobenius powers of ideals,"This paper proves some special cases in which localization of tight closure
+holds. In particular it studies the condition LC relating to bounding the Loewy
+lengths of local cohomology of Frobenius iterates of quotient rings.",1408.7100v1
+2014-11-08,Differential capacitance of the electric double layer: The interplay between ion finite size and dielectric decrement,"We study the electric double layer by combining the effects of ion finite
+size and dielectric decrement. At high surface potential, both mechanisms can
+cause saturation of the counter-ion concentration near a charged surface. The
+modified Grahame equation and differential capacitance are derived analytically
+for a general expression of a permittivity epsilon(n) that depends on the local
+ion concentration, n, and under the assumption that the co-ions are fully
+depleted from the surface. The concentration at counter-ion saturation is found
+for any epsilon(n), and a criterion predicting which of the two mechanisms
+(steric vs. dielectric decrement) is the dominant one is obtained. At low
+salinity, the differential capacitance as function of surface potential has two
+peaks (so-called camel-shape). Each of these two peaks is connected to a
+saturation of counter-ion concentration caused either by dielectric decrement
+or by their finite size. Because these effects depend mainly on the counter-ion
+concentration at the surface proximity, for opposite surface-potential polarity
+either the cations or anions play the role of counter-ions, resulting in an
+asymmetric camel-shape. At high salinity, we obtain and analyze the crossover
+in the differential capacitance from a double-peak shape to a uni-modal one.
+Finally, several nonlinear models of the permittivity decrement are considered,
+and we predict that the concentration at dielectrophoretic saturation shifts to
+higher concentration than those obtained by the linear decrement model.",1411.2092v2
+2015-02-04,Effects of liquid pore water on acoustic wave propagation in snow as a Biot-type porous material,"A method to estimate phase velocity and attenuation of acoustic waves in the
+presence of liquid water in a snowpack is presented. The method is based on
+Biot's theory of wave propagation in porous materials. Empirical relations and
+a priori information is used to characterize snow as a porous material as a
+function of porosity. Plane wave theory and an equivalent pore fluid are used
+to solve Biot's differential equations and to asses the impact of the air and
+water in the pore space. The liquid water in the pore space of a snow pack
+reduces the velocity of the first compressional wave by roughly 300 m/s for
+every 0.1 increase in liquid water saturation. Also the attenuation of the
+compressional waves is increased with increasing liquid water content. Two end
+member models for compaction are evaluated to asses the importance of an
+independent density measurement for an estimate of liquid pore water saturation
+in snow with acoustic waves. The two end members correspond to no compaction at
+all and to a melting sphere packing where the grains remain in contact. The
+change of velocity for the first compressional wave was found to strongly
+depend on the compaction model, while the velocity of the second compressional
+wave mainly depends on liquid water saturation. Also the attenuation for both
+compressional waves depends mainly on the liquid water saturation and only
+little on the compaction model. Finally, a simple field experiment illustrates
+the potential use of the method to estimate the liquid water content of snow
+with acoustic sensors.",1502.01332v1
+2015-06-30,Symmetry energy systematics and its high density behavior,"We explore the systematics of the density dependence of nuclear matter
+symmetry energy in the ambit of microscopic calculations with various energy
+density functionals, and find that the symmetry energy from subsaturation
+density to supra-saturation density can be well determined by three
+characteristic parameters of the symmetry energy at saturation density $\rho_0
+$, i.e., the magnitude $E_{\text{sym}}({\rho_0 })$, the density slope $L$ and
+the density curvature $K_{\text{sym}}$. This finding opens a new window to
+constrain the supra-saturation density behavior of the symmetry energy from its
+(sub-)saturation density behavior. In particular, we obtain $L=46.7 \pm 12.8$
+MeV and $K_{\text{sym}}=-166.9 \pm 168.3$ MeV as well as $E_{\text{sym}}({2\rho
+_{0}}) \approx 40.2 \pm 12.8$ MeV and $L({2\rho _{0}}) \approx 8.9 \pm 108.7$
+MeV based on the present knowledge of $E_{\text{sym}}({\rho_{0}}) = 32.5 \pm
+0.5$ MeV, $E_{\text{sym}}({\rho_c}) = 26.65 \pm 0.2$ MeV and $L({\rho_c}) =
+46.0 \pm 4.5$ MeV at $\rho_{\rm{c}}= 0.11$ fm$^{-3}$ extracted from nuclear
+mass and the neutron skin thickness of Sn isotopes. Our results indicate that
+the symmetry energy cannot be stiffer than a linear density dependence.In
+addition, we also discuss the quark matter symmetry energy since the deconfined
+quarks could be the right degree of freedom in dense matter at high baryon
+densities.",1506.09057v1
+2015-08-23,Realizing fusion systems inside finite groups,"We show that every (not necessarily saturated) fusion system can be realized
+as a full subcategory of the fusion system of a finite group. This result
+extends our previous work \cite{Park2010} and complements the related result
+\cite{LearyStancu2007} by Leary and Stancu.",1508.05667v1
+2015-12-28,Si Nanowire - Array Source Gated Transistors,"Solution processed field-effect transistors based on single crystalline
+silicon nanowires (Si NWs) with metal Schottky contacts are demonstrated. The
+semiconducting layer was deposited from a nanowire ink formulation at room
+temperature. The devices with 230nm thick SiO2 gate insulating layers show
+excellent output current-voltage characteristics with early saturation voltages
+under 2 volts, constant saturation current and exceptionally low dependence of
+saturation voltage with the gate field. Operational principles of these devices
+are markedly different from traditional ohmic-contact field-effect transistors
+(FETs), and are explained using the source-gated transistor (SGT) concept in
+which the semiconductor under the reverse biased Schottky source barrier is
+depleted leading to low voltage pinch-off and saturation of drain current.
+Device parameters including activation energy are extracted at different
+temperatures and gate voltages to estimate the Schottky barrier height for
+different electrode materials to establish transistor performance - barrier
+height relationships. Numerical simulations are performed using 2D thin-film
+approximation of the device structures at various Schottky barrier heights.
+Without any adjustable parameters and only assuming low p-doping of the
+transistor channel, the modelled data show exceptionally good correlation with
+the measured data. From both experimental and simulation results, it is
+concluded that source-barrier controlled nanowire transistors have excellent
+potential advantages compared with a standard FET including mitigation of
+short-channel effects, insensitivity in device operating currents to device
+channel length variation, higher on/off ratios, higher gain, lower power
+consumption and higher operational speed for solution processable and printable
+nanowire electronics.",1512.08501v1
+2016-03-01,Noisy Activation Functions,"Common nonlinear activation functions used in neural networks can cause
+training difficulties due to the saturation behavior of the activation
+function, which may hide dependencies that are not visible to vanilla-SGD
+(using first order gradients only). Gating mechanisms that use softly
+saturating activation functions to emulate the discrete switching of digital
+logic circuits are good examples of this. We propose to exploit the injection
+of appropriate noise so that the gradients may flow easily, even if the
+noiseless application of the activation function would yield zero gradient.
+Large noise will dominate the noise-free gradient and allow stochastic gradient
+descent toexplore more. By adding noise only to the problematic parts of the
+activation function, we allow the optimization procedure to explore the
+boundary between the degenerate (saturating) and the well-behaved parts of the
+activation function. We also establish connections to simulated annealing, when
+the amount of noise is annealed down, making it easier to optimize hard
+objective functions. We find experimentally that replacing such saturating
+activation functions by noisy variants helps training in many contexts,
+yielding state-of-the-art or competitive results on different datasets and
+task, especially when training seems to be the most difficult, e.g., when
+curriculum learning is necessary to obtain good results.",1603.00391v3
+2016-03-16,Cellular approximations of fusion systems,"In this paper we study the cellularization of classifying spaces of saturated
+fusion systems with respect to classifying spaces of finite $p$-groups. We give
+explicit criteria to decide when a classifying space is cellular and we give
+explicit computations for a family of exotic examples.",1603.05050v1
+2016-07-03,The effects of the U$_\textrm{Y}$(1) Chern-Simons term and its baryonic contribution on matter asymmetries and hypermagnetic fields,"In this paper, we study the significance of the U$_\textrm{Y}$(1)
+Chern-Simons term in general, and its baryonic contribution in particular, for
+the evolution of the matter asymmetries and the hypermagnetic field in the
+temperature range $100$GeV$\leq T \leq 10$TeV. We show that an initial helical
+hypermagnetic field, denoted by $B_Y^{(0)}$, can grow matter asymmetries from
+zero initial value. However, the growth which is initially quadratic with
+respect to $B_Y^{(0)}$, saturates for values larger than a critical value. The
+inclusion of the baryonic contribution reduces this critical value, leading to
+smaller final matter asymmetries. Meanwhile, $B_Y(T_{EW})$ becomes slightly
+larger than $B_Y^{(0)}$. In the absence of the U$_\textrm{Y}$(1) Chern-Simons
+term, the final values of matter asymmetries grow without saturation.
+Conversely, we show that an initial matter asymmetry can grow an initial seed
+of hypermagnetic field, provided the Chern-Simons term is taken into account.
+The growth process saturates when the matter asymmetry drops abruptly. When the
+baryonic contribution is included, the saturation occurs at an earlier time,
+and $B_Y (T_{EW})$ becomes larger. We also show the results can be within the
+acceptable range of present day data, provided the inverse cascade process is
+also taken into account.",1607.00650v3
+2016-07-19,Time Reversal with Post-Equalization for OFDM without CP in Massive MIMO,"This paper studies the possibility of eliminating the redundant cyclic prefix
+(CP) of orthogonal frequency division multiplexing (OFDM) in massive
+multiple-input multiple-output systems. The absence of CP increases the
+bandwidth efficiency in expense of intersymbol interference (ISI) and
+intercarrier interference (ICI). It is known that in massive MIMO, different
+types of interference fade away as the number of base station (BS) antennas
+tends to infinity. In this paper, we investigate if the channel distortions in
+the absence of CP are averaged out in the large antenna regime. To this end, we
+analytically study the performance of the conventional maximum ratio combining
+(MRC) and realize that there always remains some residual interference leading
+to saturation of signal to interference (SIR). This saturation of SIR is
+quantified through mathematical equations. Moreover, to resolve the saturation
+problem, we propose a technique based on time-reversal MRC with zero forcing
+multiuser detection (TR-ZF). Thus, the SIR of our proposed TR-ZF does not
+saturate and is a linear function of the number of BS antennas. We also show
+that TR-ZF only needs one OFDM demodulator per user irrespective of the number
+of BS antennas; reducing the BS signal processing complexity significantly.
+Finally, we corroborate our claims as well as analytical results through
+simulations.",1607.05653v1
+2016-09-16,On asymptotic dynamics for $L^2$ critical generalized KdV equations with a saturated perturbation,"In this paper, we consider the $L^2$ critical gKdV equation with a saturated
+perturbation: $\partial_t u+(u_{xx}+u^5-\gamma u|u|^{q-1})_x=0$, where $q>5$
+and $0<\gamma\ll1$. For any initial data $u_0\in H^1$, the corresponding
+solution is always global and bounded in $H^1$. This equation has a family of
+solitons, and our goal is to classify the dynamics near soliton. Together with
+a suitable decay assumption, there are only three possibilities: (i) the
+solution converges asymptotically to a solitary wave, whose $H^1$ norm is of
+size $\gamma^{-2/(q-1)}$, as $\gamma\rightarrow0$; (ii) the solution is always
+in a small neighborhood of the modulated family of solitary waves, but blows
+down at $+\infty$; (iii) the solution leaves any small neighborhood of the
+modulated family of the solitary waves. This extends the classification of the
+rigidity dynamics near the ground state for the unperturbed $L^2$ critical gKdV
+(corresponding to $\gamma=0$) by Martel, Merle and Rapha\""el. However, the
+blow-down behavior (ii) is completely new, and the dynamics of the saturated
+equation cannot be viewed as a perturbation of the $L^2$ critical dynamics of
+the unperturbed equation. This is the first example of classification of the
+dynamics near ground state for a saturated equation in this context. The cases
+of $L^2$ critical NLS and $L^2$ supercritical gKdV, where similar
+classification results are expected, are completely open.",1609.05146v3
+2016-12-02,"Development of a hybrid learning system based on SVM, ANFIS and domain knowledge: DKFIS","This paper presents the development of a hybrid learning system based on
+Support Vector Machines (SVM), Adaptive Neuro-Fuzzy Inference System (ANFIS)
+and domain knowledge to solve prediction problem. The proposed two-stage Domain
+Knowledge based Fuzzy Information System (DKFIS) improves the prediction
+accuracy attained by ANFIS alone. The proposed framework has been implemented
+on a noisy and incomplete dataset acquired from a hydrocarbon field located at
+western part of India. Here, oil saturation has been predicted from four
+different well logs i.e. gamma ray, resistivity, density, and clay volume. In
+the first stage, depending on zero or near zero and non-zero oil saturation
+levels the input vector is classified into two classes (Class 0 and Class 1)
+using SVM. The classification results have been further fine-tuned applying
+expert knowledge based on the relationship among predictor variables i.e. well
+logs and target variable - oil saturation. Second, an ANFIS is designed to
+predict non-zero (Class 1) oil saturation values from predictor logs. The
+predicted output has been further refined based on expert knowledge. It is
+apparent from the experimental results that the expert intervention with
+qualitative judgment at each stage has rendered the prediction into the
+feasible and realistic ranges. The performance analysis of the prediction in
+terms of four performance metrics such as correlation coefficient (CC), root
+mean square error (RMSE), and absolute error mean (AEM), scatter index (SI) has
+established DKFIS as a useful tool for reservoir characterization.",1612.00585v1
+2017-02-24,A Higher Structure Identity Principle,"We prove a Structure Identity Principle for theories defined on types of
+$h$-level 3 by defining a general notion of saturation for a large class of
+structures definable in the Univalent Foundations.",1702.07776v1
+2017-09-14,A new look at interpretability and saturation,"We investigate the interpretability ordering $\trianglelefteq^*$ using
+generalized Ehrenfeucht-Mostowski models. This gives a new approach to proving
+inequalities and investigating the structure of types.",1709.04899v2
+2018-01-03,A Novel Feature Descriptor for Image Retrieval by Combining Modified Color Histogram and Diagonally Symmetric Co-occurrence Texture Pattern,"In this paper, we have proposed a novel feature descriptors combining color
+and texture information collectively. In our proposed color descriptor
+component, the inter-channel relationship between Hue (H) and Saturation (S)
+channels in the HSV color space has been explored which was not done earlier.
+We have quantized the H channel into a number of bins and performed the voting
+with saturation values and vice versa by following a principle similar to that
+of the HOG descriptor, where orientation of the gradient is quantized into a
+certain number of bins and voting is done with gradient magnitude. This helps
+us to study the nature of variation of saturation with variation in Hue and
+nature of variation of Hue with the variation in saturation. The texture
+component of our descriptor considers the co-occurrence relationship between
+the pixels symmetric about both the diagonals of a 3x3 window. Our work is
+inspired from the work done by Dubey et al.[1]. These two components, viz.
+color and texture information individually perform better than existing texture
+and color descriptors. Moreover, when concatenated the proposed descriptors
+provide significant improvement over existing descriptors for content base
+color image retrieval. The proposed descriptor has been tested for image
+retrieval on five databases, including texture image databases - MIT VisTex
+database and Salzburg texture database and natural scene databases Corel 1K,
+Corel 5K and Corel 10K. The precision and recall values experimented on these
+databases are compared with some state-of-art local patterns. The proposed
+method provided satisfactory results from the experiments.",1801.00879v1
+2018-04-03,Fusion systems on p-groups of sectional rank 3,"We study saturated fusion systems on $p$-groups having sectional rank $3$ for
+all odd primes $p$. For $p\geq 5$, we obtain a complete classification of the
+ones that do not have any non-trivial normal $p$-subgroups.",1804.00883v2
+2018-06-22,Saturation Effect on Photoionization-driven Broad Absorption Line Variability,"We study the saturation effect on broad absorption line (BAL) variability
+through a variation phenomenon, which shows significant variation in Si IV BAL
+but no, or only small, change in C IV BAL (hereafter Phenomenon I). First, we
+explore a typical case showing Phenomenon I, quasar SDSS J153715.74+582933.9
+(hereafter J1537+5829). We identify four narrow absorption line (NAL) systems
+within its Si IV BAL and two additional NAL systems within its C IV BAL, and
+confirm their coordinated weakening. Combining with the obvious strengthening
+of the ionizing continuum, we attribute the BAL variability in J1537+5829 to
+the ionization changes caused by the continuum variations. Secondly, a
+statistical study based on multiobserved quasars from SDSS-I/II/III is
+presented. We confirm that (1) the moderate anticorrelation between the
+fractional variations of Si IV BALs and the continuum in 74 quasars that show
+Phenomenon I and (2) the sample showing BAL variations tends to have larger
+ionizing continuum variations. These results reveal the ubiquitous effect of
+the continuum variability on Phenomenon I and BAL variation. We attribute the
+relative lack of variation of C IV BALs in Phenomenon I to the saturation
+effects. Nonetheless, these absorbers are not very optically thick in Si IV and
+the ionization changes in response to continuum variations could be the main
+driver of their variations. Finally, we find that the saturation effect on BAL
+variability can well explain many phenomena of BAL variations that have been
+reported before.",1806.08673v2
+2018-07-02,Deep convolutional encoder-decoder networks for uncertainty quantification of dynamic multiphase flow in heterogeneous media,"Surrogate strategies are used widely for uncertainty quantification of
+groundwater models in order to improve computational efficiency. However, their
+application to dynamic multiphase flow problems is hindered by the curse of
+dimensionality, the saturation discontinuity due to capillarity effects, and
+the time-dependence of the multi-output responses. In this paper, we propose a
+deep convolutional encoder-decoder neural network methodology to tackle these
+issues. The surrogate modeling task is transformed to an image-to-image
+regression strategy. This approach extracts high-level coarse features from the
+high-dimensional input permeability images using an encoder, and then refines
+the coarse features to provide the output pressure/saturation images through a
+decoder. A training strategy combining a regression loss and a segmentation
+loss is proposed in order to better approximate the discontinuous saturation
+field. To characterize the high-dimensional time-dependent outputs of the
+dynamic system, time is treated as an additional input to the network that is
+trained using pairs of input realizations and of the corresponding system
+outputs at a limited number of time instances. The proposed method is evaluated
+using a geological carbon storage process-based multiphase flow model with a
+2500-dimensional stochastic permeability field. With a relatively small number
+of training data, the surrogate model is capable of accurately characterizing
+the spatio-temporal evolution of the pressure and discontinuous CO2 saturation
+fields and can be used efficiently to compute the statistics of the system
+responses.",1807.00882v1
+2018-08-03,Assessing saturation physics explanations of collectivity in small collision systems with the IP-Jazma model,"Experimental measurements in collisions of small systems from p+p to
+p/d/3He+A at RHIC and the LHC reveal particle emission patterns that are
+strikingly similar to those observed in A+A collisions. One explanation of
+these patterns is the formation of small droplets of quark-gluon plasma
+followed by hydrodynamic evolution. A geometry engineering program was proposed
+[1] to investigate these emission patterns, and the experimental data from that
+program in p+Au, d+Au, 3He+Au collisions for elliptic and triangular anisotropy
+coefficients v2 and v3 follow the pattern predicted by hydrodynamic
+calculations [2]. One alternative approach, referred to as initial-state
+correlations, suggests that for small systems the patterns observed in the
+final-state hadrons are encoded at the earliest moments of the collision, and
+therefore require no final-state parton scattering or hydrodynamic evolution
+[3,4]. Recently, new calculations using only initial-state correlations, in the
+dilute-dense approximation of gluon saturation physics, reported striking
+agreement with the v2 patterns observed in p/d/3He+Au data at RHIC [5]. The
+reported results are counterintuitive and thus we aim here to reproduce some of
+the basic features of these calculations. In this first investigation, we
+provide a description of our model, IP-Jazma, and investigate its implications
+for saturation scales, multiplicity distributions and eccentricities, reserving
+for later work the analysis of momentum spectra and azimuthal anisotropies. We
+find that our implementation of the saturation physics model reproduces the
+results of the earlier calculation of the multiplicity distribution in d+Au
+collisions at RHIC. However, our investigations, together with existing data,
+call into question some of the essential elements reported in Ref. [5].",1808.01276v1
+2018-09-06,Fusion systems on maximal class $3$-groups of rank two revisited,"We complete the determination of saturated fusion systems on maximal class
+3-groups of rank two.",1809.01957v3
+2018-11-18,The role of the thermal $f_0(500)$ in chiral symmetry restoration,"We show that the $\sigma/f_0(500)$ state with finite-temperature $T$
+corrections to its spectral properties included, plays an essential role for
+the description of the scalar susceptibility $\chi_S$, signaling chiral
+symmetry restoration. First, we use the $O(4)$ Linear Sigma Model as a testbed
+to derive the connection between $\chi_S$ and the $\sigma$ propagator and to
+check the validity and reliability of the approach where $\chi_S$ is saturated
+by the $\sigma/f_0(500)$ inverse self-energy, which we calculate at finite $T$
+to one loop. A more accurate phenomenological description is achieved by
+considering the saturation approach as given by the thermal $f_0(500)$ state
+generated in Unitarized Chiral Perturbation Theory. Such approach allows to
+describe fairly well recent lattice data within the uncertainty range given by
+the UChPT parameters. Finally, we compare the UChPT saturated description with
+one based on the Hadron Resonance Gas, for which the hadron mass dependences
+are extracted from recent theoretical analysis. Several fits to lattice data
+are performed, which confirm the validity of the thermal $f_0(500)$ saturated
+approach and hence the importance of that thermal state for chiral symmetry
+restoration.",1811.07304v2
+2018-12-30,Van der Waals equation of state and PVT properties of real fluid,"It is shown that: in the case when two parameters of the Van der Waals
+equation of state are defined from the critical temperature and pressure the
+exact parametrical solution of the equations of the liquid-vapor phase
+equilibrium of the Van der Waals fluid quantitatively describes the
+experimental dependencies of the saturated pressure of argon on the temperature
+and reduced vapor density, and it gives the quantitative description of the
+temperature dependencies of the reduced densities near critical point. When the
+parameters are defined from the critical pressure and density the parametric
+solution describes quantitatively the experimental dependencies of the
+saturated pressure of argon on the density and reduced temperature, it can
+describe qualitatively the dependencies of the vapor and liquid densities on
+the reduced temperature, and it gives the quantitative description of the
+dependencies of the densities on the reduced temperature near critical point.
+If the parameters are defined from the critical temperature and density then
+the exact solution describes quantitatively the experimental dependencies of
+the reduced saturated pressure of argon on the density and temperature, it
+describes qualitatively the temperature dependencies of the vapor and liquid
+densities of argon, and it gives the quantitative description of the
+temperature dependencies of the vapor and liquid densities near critical point.
+It is also shown that the Van der Waals equation of state describes
+quantitatively the reference experimental PVT- data for the gas and
+supercritical fluid states for the under-critical densities of argon, the
+dependencies of the saturation pressure on the temperature and vapor density,
+and the dependence of the vapor density of argon on temperature if the
+parameters are defined from the critical pressure and temperature.",1812.11572v1
+2019-05-01,Ultrafast two-dimensional field spectroscopy of terahertz intersubband saturable absorbers,"Intersubband (ISB) transitions in semiconductor multi-quantum well (MQW)
+structures are promising candidates for the development of saturable absorbers
+at terahertz (THz) frequencies. Here, we exploit amplitude and phase-resolved
+two-dimensional (2D) THz spectroscopy on the sub-cycle time scale to observe
+directly the saturation dynamics and coherent control of ISB transitions in a
+metal-insulator MQW structure. Clear signatures of incoherent pump-probe and
+coherent four-wave mixing signals are recorded as a function of the peak
+electric field of the single-cycle THz pulses. All nonlinear signals reach a
+pronounced maximum for a THz electric field amplitude of 11 kV/cm and decrease
+for higher fields. We demonstrate that this behavior is a fingerprint of
+THz-driven carrier-wave Rabi flopping. A numerical solution of the
+Maxwell-Bloch equations reproduces our experimental findings quantitatively and
+traces the trajectory of the Bloch vector. This microscopic model allows us to
+design tailored MQW structures with optimized dynamical properties for
+saturable absorbers that could be used in future compact semiconductor-based
+single-cycle THz sources.",1905.00205v1
+2019-05-13,Self-Diffusion of Glycerol in $γ$-Alumina Nanopores: Understanding the Effect of Pore Saturation on the Dynamics of Confined Polyalcohols,"Molecular Dynamics simulations of glycerol confined in $\gamma$-Al$_2$O$_3$
+slit nanopores are used to explain controversial and inconsistent observations
+reported in the literature regarding the dynamics of viscous fluids in confined
+geometries. Analysing the effects of the degree of confinement and pore
+saturation in this system, we found that the presence of the solid/liquid
+interface and the liquid/gas interface in partially saturated pores are the
+main contributors for the disruption of the hydrogen bond network of glycerol.
+Despite the reduction of hydrogen bonds between glycerol molecules caused by
+the presence of the solid, glycerol molecules near the solid surface can
+establish hydrogen bonds with the hydroxyl groups of $\gamma$-Al$_2$O$_3$ that
+significantly slow-down the dynamics of the confined fluid compared to the bulk
+liquid. On the other hand, the disruption of the hydrogen bond network caused
+by the liquid/gas interface in unsaturated pores reduces significantly the
+number of hydrogen bonds between glycerol molecules and results in a faster
+dynamics than in the bulk liquid. Therefore, we suggest that the discrepancies
+reported in the literature are a consequence of measurements carried out under
+different pore saturation conditions.",1905.05159v1
+2019-05-19,Surface Water Formation on the Natural Surface under Super-saturation: from Local Water Balance to Air Pollutant Deposition,"Heterogeneous nucleation and subsequent growth of surface water occur on the
+natural substrate when the water vapor concentration reached the point of
+super-saturation. This study focuses on the parameterization of
+super-saturation on the canopy-air interface by field observations monitoring
+surface water formation (SWF) such as dew and frost in the evergreen shrub at
+an urban cite during autumn and winter in 2015-2017. Here we show that both the
+interfacial and vertical temperature differences ranged from 1 to 3 K and were
+necessary but not sufficient for super-saturated condensation on the natural
+surface. Excessive supplies of moisture must exist, continuously contribute to
+the growth of the condensed water embryos, originate from both the local and
+the external sources such as evapotranspiration and atmospheric advection
+driven by the reduced air pressure, cause SWF not only on the ground soil but
+also on the vegetation canopy at 1-2 m height. The super-saturation ratio is
+mainly determined by the coefficient of thermophoresis deposition, which
+approaches to 1. SWF on the natural surface is not only an indicator but also a
+weak cleaner of air pollution. The downward thermophoresis deposition of fine
+particle and droplets favors SWF and the scavenging of air pollutants. The
+removal efficiency of the deposition flux during SWF event for [SO42-+NO3-] is
+estimated by ~0.3 mmol (per [Ca2+] meq)/m2(per leaf area).",1905.07701v1
+2019-06-05,Equation of state effects in the core collapse of a $20$-$M_\odot$ star,"Uncertainties in our knowledge of the properties of dense matter near and
+above nuclear saturation density are among the main sources of variations in
+multi-messenger signatures predicted for core-collapse supernovae (CCSNe) and
+the properties of neutron stars (NSs). We construct 97 new finite-temperature
+equations of state (EOSs) of dense matter that obey current experimental,
+observational, and theoretical constraints and discuss how systematic
+variations in the EOS parameters affect the properties of cold nonrotating NSs
+and the core collapse of a $20\,M_\odot$ progenitor star. The core collapse of
+the $20\,M_\odot$ progenitor star is simulated in spherical symmetry using the
+general-relativistic radiation-hydrodynamics code GR1D where neutrino
+interactions are computed for each EOS using the NuLib library. We conclude
+that the effective mass of nucleons at densities above nuclear saturation
+density is the largest source of uncertainty in the CCSN neutrino signal and
+dynamics even though it plays a subdominant role in most properties of cold NS
+matter. Meanwhile, changes in other observables affect the properties of cold
+NSs, while having little effect in CCSNe. To strengthen our conclusions, we
+perform six octant three-dimensional CCSN simulations varying the effective
+mass of nucleons at nuclear saturation density. We conclude that neutrino
+heating and, thus, the likelihood of explosion is significantly increased for
+EOSs where the effective mass of nucleons at nuclear saturation density is
+large.",1906.02009v1
+2019-06-28,"Singular Perturbation Theory for a Finite-Dimensional, Discrete-Time Chi Nonlinear System","This paper develops the singular perturbation theory for a particular
+discrete-time nonlinear system which models the saturating inductor buck
+converter using cycle-by-cycle digital control.",1907.00060v1
+2019-08-07,Saturated Free Algebras and Almost Indiscernible Theories,"We extend the concept of ""almost indiscernible theory"" introduced by Pillay
+and Sklinos in [Bull. Symb. Log., 2015] (which was itself a modernization and
+expansion of Baldwin and Shelah [Algebra Universalis, 1983]), to uncountable
+languages and uncountable parameter sequences. Roughly speaking a theory $T$ is
+almost indiscernible if some saturated model is in the algebraic closure of an
+indiscernible set of sequences. We show that such a theory $T$ is
+nonmultidimensional, superstable, and stable in all cardinals $\ge |T |$ . We
+prove a structure theorem for sufficiently large $a$-models $M$: Theorem 2.10
+which states that over a suitable base, $M$ is in the algebraic closure of an
+independent set of realizations of weight one types (in possibly infinitely
+many variables). We also explore further the saturated free algebras of Baldwin
+and Shelah in both the countable and uncountable context. We study in
+particular theories and varieties of $R$-modules, characterizing those rings
+$R$ for which the free $R$-module on $|R|^+$ generators is saturated (Theorem
+3.15), and pointing out a counterexample to a conjecture from Pillay-Sklinos
+(Example 3.16).",1908.02712v5
+2019-10-09,Modeling wavefields in saturated elastic porous media based on thermodynamically compatible system theory for multiphase mixtures,"A two-phase model and its application to wavefields numerical simulation are
+discussed in the context of modeling of compressible fluid flows in elastic
+porous media. The derivation of the model is based on a theory of
+thermodynamically compatible systems and on a model of nonlinear
+elastoplasticity combined with a two-phase compressible fluid flow model. The
+governing equations of the model include phase mass conservation laws, a total
+momentum conservation law, an equation for the relative velocities of the
+phases, an equation for mixture distortion, and a balance equation for
+porosity. They form a hyperbolic system of conservation equations that satisfy
+the fundamental laws of thermodynamics. Two types of phase interaction are
+introduced in the model: phase pressure relaxation to a common value and
+interfacial friction. Inelastic deformations also can be accounted for by
+source terms in the equation for distortion. The thus formulated model can be
+used for studying general compressible fluid flows in a deformable
+elastoplastic porous medium, and for modeling wave propagation in a saturated
+porous medium. Governing equations for small-amplitude wave propagation in a
+uniform porous medium saturated with a single fluid are derived. They form a
+first-order hyperbolic PDE system written in terms of stress and velocities
+and, like in Biot's model, predict three types of waves existing in real
+fluid-saturated porous media: fast and slow longitudinal waves and shear waves.
+For the numerical solution of these equations, an efficient numerical method
+based on a staggered-grid finite difference scheme is used. The results of
+solving some numerical test problems are presented and discussed",1910.04207v2
+2019-10-18,Vapor drainage in the protolunar disk as the cause for the depletion in volatile elements of the Moon,"Lunar rocks are severely depleted in moderately volatile elements such as Rb,
+K, and Zn relative to Earth. Identifying the cause of this depletion is
+important for understanding how the Earth-Moon system evolved in the aftermath
+of the Moon-forming giant impact. We measured the Rb isotopic compositions of
+lunar and terrestrial rocks to understand why moderately volatile elements are
+depleted in the Moon. Combining our new measurements with previous data reveals
+that the Moon has an 87Rb/85Rb ratio higher than Earth by +0.16 permil. This
+isotopic composition is consistent with evaporation of Rb into a vapor medium
+that was ~99 percent saturated. Evaporation under this saturation can also
+explain the previously documented isotopic fractionations of K, Ga, Cu and Zn
+of lunar rocks relative to Earth. We show that a possible setting for achieving
+the same saturation upon evaporation of elements with such diverse volatilities
+is through viscous drainage of a partially vaporized protolunar disk onto
+Earth. In the framework of an alpha-disk model, the alpha-viscosity needed to
+explain the ~99% saturation calculated here is 0.001 to 0.01, which is
+consistent with a vapor disk where viscosity is controlled by magnetorotational
+instability.",1910.08530v1
+2019-11-18,Pore network modeling of the effects of viscosity ratio and pressure gradient on steady-state incompressible two-phase flow in porous media,"We perform more than 6000 steady-state simulations with a dynamic pore
+network model, corresponding to a large span in viscosity ratios and capillary
+numbers. From these simulations, dimensionless quantities such as relative
+permeabilities, residual saturations, mobility ratios and fractional flows are
+computed. Relative permeabilities and residual saturations show many of the
+same qualitative features observed in other experimental and modeling studies.
+However, while other studies find that relative permeabilities converge to
+straight lines at high capillary numbers we find that this is not the case when
+viscosity ratios are different from 1. Our conclusion is that departure from
+straight lines occurs when fluids mix rather than form decoupled flow channels.
+Another consequence of the mixing is that computed fractional flow curves,
+plotted against saturation, lie closer to the diagonal than they would
+otherwise do. At lower capillary numbers, fractional flow curves have a
+classical S-shape. Ratios of average mobility to their high-capillary number
+limit values are also considered. These vary, roughly, between 0 and 1,
+although values larger than 1 are also observed. For a given saturation and
+viscosity ratio, the mobilities are not always monotonically increasing with
+the pressure gradient. While increasing the pressure gradient mobilizes more
+fluid and activates more flow paths, when the mobilized fluid is more viscous,
+a reduction in average mobility may occur.",1911.07490v1
+2019-12-09,Topological entropy of the set of generic points for $(α-β)$-shifts,"We prove that all ($\alpha$-$\beta$)-shifts with $0\le \alpha<1$ and
+$\beta>2$ are saturated, that is, for any invariant measure, the topological
+entropy of the set of generic points coincides with the metric entropy.",1912.03813v1
+2020-02-16,Lofty Models of Peano Arithmetic,"If M is a nonstandard model of Peano Arithmetic, then M is lofty iff M has a
+simple elementary extension that is recursively saturated. This had previously
+been known for countable M.",2002.06639v2
+2020-04-12,Heavy-hadron molecules from light-meson-exchange saturation,"In the effective field theory framework the interaction between two heavy
+hadrons can be decomposed into a long- and a short-range piece. The long-range
+piece corresponds to the one-pion-exchange potential and is relatively
+well-known. The short-range piece is given by a series of contact-range
+interactions with unknown couplings, which substitute the less well-known
+short-range dynamics. While the general structure of the short-range potential
+between heavy hadrons is heavily constrained from heavy-quark symmetry, the
+couplings are still free parameters. Here we argue that the relative strength
+and the sign of these couplings can be estimated from the hypothesis that they
+are saturated by the exchange of light mesons, in particular the vector mesons
+$\rho$ and $\omega$, i.e. from resonance saturation. However, we propose a
+novel saturation procedure that effectively removes form-factor artifacts. From
+this we can determine in which spin and isospin configurations the low-energy
+constants are most attractive for specific two-heavy-hadron systems. In general
+the molecular states with lower isospins and higher spins will be more
+attractive and thus more probable candidates to form heavy-hadron molecules.
+This pattern is compatible with the interpretation of the $X(3872)$ and
+$P_c(4312/4440/4457)$ as molecular states, but it is not applicable to states
+with maximum isospin like the $Z_c(3900/4020)$.",2004.05658v2
+2020-04-14,Synchrotron-based pore-network modeling of two-phase flow in Nubian Sandstone and implications for capillary trapping of carbon dioxide,"Depleted oil fields in the Gulf of Suez (Egypt) can serve as geothermal
+reservoirs for power generation using a CO2-Plume Geothermal (CPG) system,
+while geologically sequestering CO2. This entails the injection of a
+substantial amount of CO2 into the highly permeable brine-saturated Nubian
+Sandstone. Numerical models of two-phase flow processes are indispensable for
+predicting the CO2-plume migration at a representative geological scale. Such
+models require reliable constitutive relationships, including relative
+permeability and capillary pressure curves. In this study, quasi-static
+pore-network modelling has been used to simulate the equilibrium positions of
+fluid-fluid interfaces, and thus determine the capillary pressure and relative
+permeability curves. Three-dimensional images with a voxel size of 0.65 micro
+m3 of a Nubian Sandstone rock sample have been obtained using Synchrotron
+Radiation X-ray Tomographic Microscopy. From the images, topological properties
+of pores/throats were constructed. Using a pore-network model, we performed a
+sequential primary drainage-main imbibition cycle of quasi-static invasion in
+order to quantify (1) the CO2 and brine relative permeability curves, (2) the
+effect of initial wetting-phase saturation (i.e. the saturation at the point of
+reversal from drainage to imbibition) on the residual-trapping potential, and
+(3) study the relative permeability-saturation hysteresis. The results improve
+our understanding of the potential magnitude of capillary trapping in Nubian
+Sandstone, essential for future field-scale simulations. Further, an initial
+basin-scale assessment of CO2 storage capacity, which incorporates capillary
+trapping, yields a range of 14-49 GtCO2 in Nubian Sandstone, Gulf of Suez
+Basin.",2004.06792v1
+2020-07-03,Properties of nuclear matter in relativistic Brueckner-Hartree-Fock model with high-precision charge-dependent potentials,"Properties of nuclear matter are investigated in the framework of
+relativistic Brueckner-Hartree-Fock model with the latest high-precision
+charge-dependent Bonn (pvCD-Bonn) potentials, where the coupling between pion
+and nucleon is adopted as pseudovector form. These realistic pvCD-Bonn
+potentials are renormalized to effective nucleon-nucleon ($NN$) interactions,
+$G$ matrices. They are obtained by solving the Blankenbecler-Sugar (BbS)
+equation in nuclear medium. Then, the saturation properties of symmetric
+nuclear matter are calculated with pvCD-Bonn A, B, C potentials. The energies
+per nucleon are around $-10.72$ MeV to $-16.83$ MeV at saturation densities,
+$0.139$ fm$^{-3}$ to $0.192$ fm$^{-3}$ with these three potentials,
+respectively. It clearly demonstrates that the pseudovector coupling between
+pion and nucleon can generate reasonable saturation properties comparing with
+pseudoscalar coupling. Furthermore, these saturation properties have strong
+correlations with the tensor components of $NN$ potentials, i.e., the $D$-state
+probabilities of deuteron, $P_D$ to form a relativistic Coester band. In
+addition, the charge symmetry breaking (CSB) and charge independence breaking
+(CIB) effects are also discussed in nuclear matter from the partial wave
+contributions with these high-precision charge-dependent potentials. In
+general, the magnitudes of CSB from the differences between $nn$ and $pp$
+potentials are about $0.05$ MeV, while those of CIB are around $0.35$ MeV from
+the differences between $np$ and $pp$ potentials. Finally, the equations of
+state of asymmetric nuclear matter are also calculated with different asymmetry
+parameters. It is found that the effective neutron mass is larger than the
+proton one in neutron-rich matter.",2007.01726v1
+2020-08-10,Inclusive prompt photon-jet correlations as a probe of gluon saturation in electron-nucleus scattering at small $x$,"We compute the differential cross-section for inclusive prompt photon$+$quark
+production in deeply inelastic scattering of electrons off nuclei at small $x$
+($e+A$ DIS) in the framework of the Color Glass Condensate effective field
+theory. The result is expressed as a convolution of the leading order (in the
+strong coupling $\alpha_{\mathrm{s}}$) impact factor for the process and
+universal dipole matrix elements, in the limit of hard photon transverse
+momentum relative to the nuclear saturation scale $Q_{s,A}(x)$. We perform a
+numerical study of this process for the kinematics of the Electron-Ion Collider
+(EIC), exploring in particular the azimuthal angle correlations between the
+final state photon and quark. We observe a systematic suppression and
+broadening pattern of the back-to-back peak in the relative azimuthal angle
+distribution, as the saturation scale is increased by replacing proton targets
+with gold nuclei. Our results suggest that photon+jet final states in inclusive
+$e+A$ DIS at high energies are in general a promising channel for exploring
+gluon saturation that is complementary to inclusive and diffractive dijet
+production. They also provide a sensitive empirical test of the universality of
+dipole matrix elements when compared to identical measurements in
+proton-nucleus collisions. However because photon+jet correlations at small $x$
+in EIC kinematics require jet reconstruction at small $k_\perp$, it will be
+important to study their feasibility relative to photon-hadron correlations.",2008.04372v1
+2020-08-24,Phase separation of saturated micellar network and its potential applications for nanoemulsification,"Phase separation of saturated micellar network, as a result of cross-linking
+of branched micelles is established in mixed solutions of the anionic
+surfactant sodium laurylethersulfate (SLES) and the zwitterionic cocamidopropyl
+betaine (CAPB) in the presence of divalent counterions: Ca2+, Zn2+ and Mg2+.
+The saturated network appears in the form of droplets, which are heavier than
+water and sediment at the bottom of the vessel. In the case of Mg2+, the
+sedimented drops coalesce and form a separate multiconnected micellar phase - a
+supergiant surfactant micelle. For this phase, the rheological flow curves show
+Newtonian and shear-thinning regions. The appearance/disappearance of the
+Newtonian region marks the onset of formation of saturated network. The
+addition of small organic molecules (fragrances) to the multiconnected micellar
+phase leads to an almost spontaneous formation of oil-in-water nanoemulsion.
+The nanoemulsification capacity of the multiconnected micellar phase decreases
+with the rise of the volume of the oil molecule. A possible role of the network
+junctions in the nanoemulsification process can be anticipated. The properties
+of the multiconnected micellar phases could find applications in extraction and
+separation processes, in drug/active delivery, and for nanoemulsification at
+minimal energy input.",2008.10494v1
+2020-10-16,"Supercards, Sunshines and Caterpillar Graphs","The vertex-deleted subgraph G-v, obtained from the graph G by deleting the
+vertex v and all edges incident to v, is called a card of G. The deck of G is
+the multiset of its unlabelled cards. The number of common cards b(G,H) of G
+and H is the cardinality of the multiset intersection of the decks of G and H.
+A supercard G+ of G and H is a graph whose deck contains at least one card
+isomorphic to G and at least one card isomorphic to H. We show how maximum sets
+of common cards of G and H correspond to certain sets of permutations of the
+vertices of a supercard, which we call maximum saturating sets. We apply the
+theory of supercards and maximum saturating sets to the case when G is a
+sunshine graph and H is a caterpillar graph. We show that, for large enough n,
+there exists some maximum saturating set that contains at least b(G,H)-2
+automorphisms of G+, and that this subset is always isomorphic to either a
+cyclic or dihedral group. We prove that b(G,H)<=2(n+1)/5 for large enough n,
+and that there exists a unique family of pairs of graphs that attain this
+bound. We further show that, in this case, the corresponding maximum saturating
+set is isomorphic to the dihedral group.",2010.08266v1
+2020-10-19,Effects of Parameter Norm Growth During Transformer Training: Inductive Bias from Gradient Descent,"The capacity of neural networks like the widely adopted transformer is known
+to be very high. Evidence is emerging that they learn successfully due to
+inductive bias in the training routine, typically a variant of gradient descent
+(GD). To better understand this bias, we study the tendency for transformer
+parameters to grow in magnitude ($\ell_2$ norm) during training, and its
+implications for the emergent representations within self attention layers.
+Empirically, we document norm growth in the training of transformer language
+models, including T5 during its pretraining. As the parameters grow in
+magnitude, we prove that the network approximates a discretized network with
+saturated activation functions. Such ""saturated"" networks are known to have a
+reduced capacity compared to the full network family that can be described in
+terms of formal languages and automata. Our results suggest saturation is a new
+characterization of an inductive bias implicit in GD of particular interest for
+NLP. We leverage the emergent discrete structure in a saturated transformer to
+analyze the role of different attention heads, finding that some focus locally
+on a small number of positions, while other heads compute global averages,
+allowing counting. We believe understanding the interplay between these two
+capabilities may shed further light on the structure of computation within
+large transformers.",2010.09697v5
+2020-11-25,Global random walk solvers for fully coupled flow and transport in saturated/unsaturated porous media (extended version),"In this article, we present new random walk methods to solve flow and
+transport problems in unsaturated/saturated porous media, including coupled
+flow and transport processes in soils, heterogeneous systems modeled through
+random hydraulic conductivity and recharge fields, processes at the field and
+regional scales. The numerical schemes are based on global random walk
+algorithms (GRW) which approximate the solution by moving large numbers of
+computational particles on regular lattices according to specific random walk
+rules. To cope with the nonlinearity and the degeneracy of the Richards
+equation and of the coupled system, we implemented the GRW algorithms by
+employing linearization techniques similar to the $L$-scheme developed in
+finite element/volume approaches. The resulting GRW $L$-schemes converge with
+the number of iterations and provide numerical solutions that are first-order
+accurate in time and second-order in space. A remarkable property of the flow
+and transport GRW solutions is that they are practically free of numerical
+diffusion. The GRW solutions are validated by comparisons with mixed finite
+element and finite volume solutions in one- and two-dimensional benchmark
+problems. They include Richards' equation fully coupled with the
+advection-diffusion-reaction equation and capture the transition from
+unsaturated to saturated flow regimes. For completeness, we also consider
+decoupled flow and transport model problems for saturated aquifers.",2011.12889v4
+2020-12-09,Electromagnetic Eigenvalue Problems and Nonhermitian Effects in Linear and Saturable Scattering,"In this thesis we address a series of new problems in non-hermitian optical
+scattering with increasing degrees of complexity.
+  We develop the theory of reflectionless scattering modes, introducing a novel
+and broad class of impedance-matched eigenproblems: for a given structure, find
+the incident wavefronts and frequencies which are not partially reflected, but
+are instead transmitted through the scatterer, or dissipated within it. We
+analyze the relevant symmetry properties, and find that they support
+exceptional points (EPs) which can be directly probed with steady-state
+excitation.
+  We study degenerate coherent perfect absorption (CPA EP), which is a specific
+example of the new kind of EP mentioned above. We show that the CPA EP is
+chiral in a ring resonator, and use this to design a resonator which
+predominantly absorbs or reflects light, depending on the direction of
+incidence.
+  We extend CPA from cavities with a linear dielectric response to include the
+saturating nonlinearity and dispersion of a two-level absorbing medium. We show
+that the SALT algorithm in the single-mode regime can also be used to find the
+saturable CPA modes through a simple mapping. We also clarify the bad-cavity
+limit of dispersive but linear CPA, identifying new modes that are hybrids of
+the cavity and atomic degrees of freedom.
+  We present and solve the general problem of scattering from an arbitrary
+cavity with a saturable two-level amplifying or absorbing medium, generalizing
+the known phenomenology of bistability that has mainly been studied in
+structures with little or no spatial complexity. We carefully analyze the
+validity of approximations used for isolated resonances, and find that the
+previously used inverse single-pole approximation requires some modification
+for the case of scattering.",2012.05035v1
+2021-01-07,Particle-in-cell Simulation of the Neutrino Fast Flavor Instability,"Neutrinos drive core-collapse supernovae, launch outflows from neutron star
+merger accretion disks, and set the ratio of protons to neutrons in ejecta from
+both systems that generate heavy elements in the universe. Neutrinos of
+different flavors interact with matter differently, and much recent work has
+suggested that fast flavor instabilities are likely ubiquitous in both systems,
+but the final flavor content after the instability saturates has not been well
+understood. In this work we present particle-in-cell calculations which follow
+the evolution of all flavors of neutrinos and antineutrinos through saturation
+and kinematic decoherence. We conduct one-dimensional three-flavor simulations
+of neutrino quantum kinetics to demonstrate the outcome of this instability in
+a few example cases. We demonstrate the growth of both axially symmetric and
+asymmetric modes whose wavelength and growth rate match predictions from linear
+stability analysis. Finally, we vary the number density, flux magnitude, and
+flux direction of the neutrinos and antineutrinos and demonstrate that these
+factors modify both the growth rate and post-saturation neutrino flavor
+abundances. Weak electron lepton number (ELN) crossings in these simulations
+produce both slow growth of the instability and little difference between the
+flavor abundances in the initial and final states. In all of these calculations
+the same number of neutrinos and antineutrinos change flavor, making the least
+abundant between them the limiting factor for post-saturation flavor change.
+Many more simulations and multi-dimensional simulations are needed to fully
+probe the parameter space of the initial conditions.",2101.02745v2
+2021-01-08,Simulating volume-controlled invasion of a non-wetting fluid in volumetric images using basic image processing tools,"A new algorithm is presented for simulating volume-controlled invasion of a
+non-wetting phase into voxel images. This method is complementary to the
+traditional morphological image opening method which mimics pressure-based
+invasion. A key advantage of the volume-based approach is that all saturations
+between 0 and 1 can obtained rather than the irregularly and widely spaced
+saturation steps obtained by pressure-based methods. Because of the incremental
+increases in saturation, it becomes possible to correctly predict defending
+phase trapping, which is not the case when pressure-based steps are applied.
+The algorithm is validated against morphological image opening and obtains near
+perfect agreement at equal saturations as expected from theory. It is also
+demonstrated that a volume-controlled capillary pressure curve can be obtained
+that displays the characteristic jumps in capillary pressure, and moreover, the
+envelop of peak pressures yields the pressure-based capillary pressure obtained
+by morphological opening, so in fact the results of the proposed algorithm are
+a superset of the morphological approach. Finally, results are compared to
+multiphase lattice Boltzmann and qualitatively similar results were achieved in
+substantially less time. The lattice Boltzmann method is more flexible in terms
+of variable contact angle and inclusion of viscous effects, but for
+quasi-static volume-based injection of a non-wetting fluid, the proposed method
+is viable alternative.",2101.03240v1
+2021-02-02,First Saturation Correction in High Energy Proton-Nucleus Collisions: I. Time evolution of classical Yang-Mills fields beyond leading order,"In high energy proton-nucleus collisions, the single- and double-inclusive
+soft gluon productions at the leading order have been calculated and
+phenomenologically studied in various approaches for many years. These studies
+do not take into account the saturation and multiple rescatterings in the field
+of the proton. The first saturation correction to these leading order results
+(the terms that are enhanced by the combination $\alpha_s^2 \mu^2$, where
+$\mu^2$ is the proton's color charge squared per unit transverse area) has not
+been completely derived despite recent attempts using a diagrammatic approach.
+This paper is the first in a series of papers towards analytically completing
+the first saturation correction to physical observables in high energy
+proton-nucleus collisions. Our approach is to analytically solve the classical
+Yang-Mills equations in the dilute-dense regime using the Color Glass
+Condensate effective theory and compute physical observables constructed from
+classical gluon fields. In the current paper, the Yang-Mills equations are
+solved perturbatively in the field of the dilute object (the proton).
+Next-to-leading order and next-to-next-to-leading order analytic solutions are
+explicitly constructed. A systematic way to obtain all higher order analytic
+solutions is outlined",2102.01594v1
+2021-03-02,An analytic BRDF for materials with spherical Lambertian scatterers,"We present a new analytic BRDF for porous materials comprised of spherical
+Lambertian scatterers. The BRDF has a single parameter: the albedo of the
+Lambertian particles. The resulting appearance exhibits strong back scattering
+and saturation effects that height-field-based models such as Oren-Nayar cannot
+reproduce.",2103.01618v1
+2021-04-08,Active Power Control of Waked Wind Farms: Compensation of Turbine Saturation and Thrust Force Balance,"Active power control regulates the total power generated by wind farms with
+the power consumed on the electricity grid. Due to wake effects, the available
+power is reduced and turbulence is increased at downstream wind turbines. Such
+effects lead to a design challenge for wind farm control, where the delicate
+balance between supply and demand should be maintained, while considering the
+load balancing in the wind turbine structures. We propose a control
+architecture based on simple feedback controllers that adjusts the demanded
+power set points of individual wind turbines to compensate for turbine
+saturations and to balance thrust forces. For compensation purposes, the
+dynamics of power tracking in the wind turbines is approximated as a pure
+time-delay process, and the thrust force balance design is based on an
+identified linear model of the turbines. In this paper, we show that the
+proposed control architecture allows the generated power to track its reference
+even when turbines saturate, while the thrust forces are balanced. In addition,
+the result shows that the proposed power dispatch strategy, which considers
+thrust force balance, also avoids turbine saturation, being thus beneficial for
+energy production. The effectiveness of the proposed feedback controller is
+demonstrated using high-fidelity computational fluid dynamics simulations of a
+small wind farm.",2104.03894v1
+2021-04-24,On loop spaces with marking,"An analogous construction of simplicial homotopy group for Kan complex can be
+applied to saturated complicial sets to give monoids. In this paper, we
+investigate how the construction of loop spaces of Kan complexes lifts to the
+complicial setting and relates to such monoids.",2104.11860v1
+2021-04-27,Mitigation of Saturated Cut-sets During Multiple Outages to Enhance Power System Security,"Ensuring reliable operation of large power systems subjected to multiple
+outages is a challenging task because of the combinatorial nature of the
+problem. Traditional approaches for security assessment are often limited by
+their scope and/or speed, resulting in missing of critical contingencies that
+could lead to cascading failures. This paper proposes a two-component
+methodology to enhance power system security. The first component combines an
+efficient algorithm to detect cut-set saturation (called the feasibility test
+(FT) algorithm) with real-time contingency analysis (RTCA) to create an
+integrated corrective action (iCA), whose goal is to secure the system against
+cut-set saturation as well as critical branch overloads. The second component
+only employs the results of the FT to create a relaxed corrective action (rCA)
+to secure the system against post-contingency cut-set saturation. The first
+component is more comprehensive, but the latter is computationally more
+efficient. The effectiveness of the two components is evaluated based upon the
+number of cascade triggering contingencies alleviated, and the computation
+time. The results obtained by analyzing different case-studies on the IEEE
+118-bus and 2000-bus synthetic Texas systems indicate that the proposed
+two-component methodology successfully enhances the scope and speed of power
+system security assessment during multiple outages.",2104.13445v2
+2021-05-09,Probabilistic forecast of multiphase transport under viscous and buoyancy forces in heterogeneous porous media,"In this study, we develop a probabilistic approach to map the parametric
+uncertainty to the output state uncertainty in first-order hyperbolic
+conservation laws. We analyze this problem for nonlinear immiscible two-phase
+transport in heterogeneous porous media in the presence of a stochastic
+velocity field. The uncertainty in the velocity field can arise from the
+incomplete description of either porosity field, injection flux, or both. The
+uncertainty in the total-velocity field leads to the spatiotemporal uncertainty
+in the saturation field. Given information about the spatial/temporal
+statistics of the correlated heterogeneity, we leverage method of distributions
+to derive deterministic equations that govern the evolution of single-point CDF
+of saturation. Unlike Buckley Leverett equation, the equation for the raw CDF
+function is linear in space and time. Hereby, we give routes to circumventing
+the computational cost of Monte Carlo scheme while obtaining the full
+statistical description of saturation. We conduct a set of numerical
+experiments and compare statistics of saturation computed with the method of
+distributions, against those obtained using the statistical moment equations
+approach and kernel density estimation post-processing of high-resolution Monte
+Carlo simulations. This comparison demonstrates that the CDF equations remain
+accurate over a wide range of statistical properties, i.e. standard deviation
+and correlation length of the underlying random fields, while the corresponding
+low-order statistical moment equations significantly deviate from Monte Carlo
+results, unless for very small values of standard deviation and correlation
+length.",2105.03988v1
+2021-05-16,On the theory of Biot-patchy-squirt mechanism for wave propagation in partially saturated double-porosity medium,"Reservoir rocks are usually composed of a coherent heterogeneous porous
+matrix saturated by multiple fluids. At long wavelength limit, the composite
+material of solid skeleton is usually regarded as homogeneous media. However,
+at grain scale or high loading rate, non-uniform fluid flow at internal
+interface of heterogeneity plays essential role in wave dispersion and
+attenuation. Formulating wave propagation in partially saturated and fractured
+rocks is challenging and of great interests in geoscience. Here we raise a
+Biot-patchy-squirt (BIPS) model to characterize wave dispersion/attenuation in
+fractured poroelastic media saturated by two immiscible fluids. BIPS model
+incorporates the mechanism of local fluid-interface flow (LFIF) and squirt flow
+into global fluid flow simultaneously. Theoretical analysis show that wave
+attenuations caused by viscous dissipation, squirt flow and patchy interface
+vibration are distinct from each other. BIPS is intrinsically consistent with
+Biot theory, squirt and LFIF model and reduces to such mechanism in limiting
+conditions. More interestingly, numerical results show that coupling between
+LFIF and squirt flow is of evident importance to P-wave dispersion and
+attenuation. Comparisons with experimental data indicate that BIPS model is
+computationally reliable and in reasonably good agreement with experimental
+data. This study advance our understanding of the fundamental physics of wave
+propagation in natural reservoir rocks and push forward the potential
+applications of the triple dispersion/attenuation mechanism to wave velocity
+estimation in deep earth.",2105.07429v2
+2021-06-12,Stiffening of matter in quark-hadron continuity,"We discuss stiffening of matter in quark-hadron continuity. We introduce a
+model that relates quark wave functions in a baryon and the occupation
+probability of states for baryons and quarks in dense matter. In a dilute
+regime, the confined quarks contribute to the energy density through the masses
+of baryons, but do not directly contribute to the pressure; hence, the
+equations of state are very soft. This dilute regime continues until the low
+momentum states for quarks get saturated; this may happen even before baryons
+fully overlap, possibly at density slightly above the nuclear saturation
+density. After the saturation the pressure grows rapidly while changes in
+energy density are modest, producing a peak in the speed of sound. If we use
+baryonic descriptions for quark distributions near the Fermi surface, we reach
+a description similar to the quarkyonic matter model of McLerran and Reddy.
+With a simple adjustment of quark interactions to get the nucleon mass, our
+model becomes consistent with the constraints from 1.4-solar mass neutron
+stars, but the high density part is too soft to account for two-solar mass
+neutron stars. We delineate the relation between the saturation effects and
+short range interactions of quarks, suggesting interactions that leave low
+density equations of state unchanged but stiffen the high density part.",2106.06687v3
+2021-06-21,The importance of kinematic twists and genuine saturation effects in dijet production at the Electron-Ion Collider,"We compute the differential yield for quark anti-quark dijet production in
+high-energy electron-proton and electron-nucleus collisions at small $x$ as a
+function of the relative momentum $\boldsymbol{P}_\perp$ and momentum imbalance
+$\boldsymbol{k}_\perp$ of the dijet system for different photon virtualities
+$Q^2$, and study the elliptic and quadrangular anisotropies in the relative
+angle between $\boldsymbol{P}_\perp$ and $\boldsymbol{k}_\perp$. We review and
+extend the analysis in [1], which compared the results of the Color Glass
+Condensate (CGC) with those obtained using the transverse momentum dependent
+(TMD) framework. In particular, we include in our comparison the improved TMD
+(ITMD) framework, which resums kinematic power corrections of the ratio
+$k_\perp$ over the hard scale $Q_\perp$. By comparing ITMD and CGC results we
+are able to isolate genuine higher saturation contributions in the ratio
+$Q_s/Q_\perp$ which are resummed only in the CGC. These saturation
+contributions are in addition to those in the Weizs\""ackerWilliams gluon TMD
+that appear in powers of $Q_s/k_\perp$. We provide numerical estimates of these
+contributions for inclusive dijet production at the future Electron-Ion
+Collider, and identify kinematic windows where they can become relevant in the
+measurement of dijet and dihadron azimuthal correlations. We argue that such
+measurements will allow the detailed experimental study of both kinematic power
+corrections and genuine gluon saturation effects.",2106.11301v3
+2021-07-29,Maximize the Foot Clearance for a Hopping Robotic Leg Considering Motor Saturation,"A hopping leg, no matter in legged animals or humans, usually behaves like a
+spring during the periodic hopping. Hopping like a spring is efficient and
+without the requirement of complicated control algorithms. Position and force
+control are two main methods to realize such a spring-like behaviour. The
+position control usually consumes the torque resources to ensure the position
+accuracy and compensate the tracking errors. In comparison, the force control
+strategy is able to maintain a high elasticity. Currently, the position and
+force control both leads to the discount of motor saturation ratio as well as
+the bandwidth of the control system, and thus attenuates the performance of the
+actuator. To augment the performance, this letter proposes a motor saturation
+strategy based on the force control to maximize the output torque of the
+actuator and realize the continuous hopping motion with natural dynamics. The
+proposed strategy is able to maximize the saturation ratio of motor and thus
+maximize the foot clearance of the single leg. The dynamics of the two-mass
+model is utilized to increase the force bandwidth and the performance of the
+actuator. A single leg with two degrees of freedom is designed as the
+experiment platform. The actuator consists of a powerful electric motor, a
+harmonic gear and encoder. The effectiveness of this method is verified through
+simulations and experiments using a robotic leg actuated by powerful high
+reduction ratio actuators.",2107.13717v2
+2021-08-04,Forced Imbibition in Stratified Porous Media: Fluid Dynamics and Breakthrough Saturation,"Imbibition, the displacement of a nonwetting fluid by a wetting fluid, plays
+a central role in diverse energy, environmental, and industrial processes.
+While this process is typically studied in homogeneous porous media with
+uniform permeabilities, in many cases, the media have multiple parallel strata
+of different permeabilities. How such stratification impacts the fluid dynamics
+of imbibition, as well as the fluid saturation after the wetting fluid breaks
+through to the end of a given medium, is poorly understood. We address this gap
+in knowledge by developing an analytical model of imbibition in a porous medium
+with two parallel strata, combined with a pore network model that explicitly
+describes fluid crossflow between the strata. By numerically solving these
+models, we examine the fluid dynamics and fluid saturation left after
+breakthrough. We find that the breakthrough saturation of nonwetting fluid is
+minimized when the imposed capillary number Ca is tuned to a value Ca$^*$ that
+depends on both the structure of the medium and the viscosity ratio between the
+two fluids. Our results thus provide quantitative guidelines for predicting and
+controlling flow in stratified porous media, with implications for water
+remediation, oil/gas recovery, and applications requiring moisture management
+in diverse materials.",2108.02051v1
+2021-08-11,The Bridge Lemmas between Equivalent Fell Bundles and its Applications,"In this paper, we prove that the induced representation theories of two
+equivalent Fell bundles are essentially identical; and we apply our results to
+carry the induced representation theory and imprimitivity theorems of saturated
+Fell bundles to arbitrary Fell bundles.",2108.05003v1
+2021-08-26,Fusion Systems on a Sylow $p$-subgroup of $\mathrm{G}_2(p^n)$ or $\mathrm{PSU}_4(p^n)$,"For any prime $p$ and $S$ a $p$-group isomorphic to a Sylow $p$-subgroup of
+$\mathrm{G}_2(p^n)$ or $\mathrm{PSU}_4(p^n)$ with $n\in\mathbb{N}$, we
+determine all saturated fusion systems supported on $S$ up to isomorphism.",2108.11691v1
+2021-08-27,Multiple moist climate equilibrium states on arid rocky M-dwarf planets: A last-saturation tracer analysis,"Terrestrial-type exoplanets orbiting nearby red dwarf stars (M dwarfs) are
+the first potentially habitable exoplanets suitable for atmospheric
+characterization in the near future. Understanding the stability of water in
+cold-trap regions on such planets is critical because it directly impacts
+transmission spectroscopy observations, the global energy budget, and long-term
+surface water evolution. Here we diagnose the humidity distribution in
+idealized general circulation model (GCM) simulations of terrestrial-type
+exoplanets. We use the `tracer of last saturation' technique to study the
+saturation statistics of air parcels. We find that on synchronously rotating
+planets, the water vapor abundance in the nightside upper troposphere depends
+weakly on planetary rotation, while more water vapor builds up in the nightside
+lower troposphere on fast-rotating planets. We then discuss how last-saturation
+statistics can elucidate the multiple moist climate equilibrium states on
+synchronously and asynchronously rotating arid planets. We show that the
+multiple moist climate states arise from the cold-trapping competition between
+the substellar upper atmosphere and cold surface regions. We find that fast
+synchronously rotating planets tend to trap surface water on the nightside as a
+result of their weak atmospheric and strong surface cold traps compared to the
+slow rotating case. These results elucidate the nature of the water cycle on
+arid rocky exoplanets and will aid interpretation of atmospheric observations
+in the future.",2108.12458v1
+2021-08-30,Accurate electron beam phase-space theory for ionisation injection schemes driven by laser pulses,"After the introduction of the ionization-injection scheme in Laser Wake Field
+Acceleration and of related high-quality electron beam generation methods as
+two-color or the Resonant Multi Pulse Ionization injection, the theory of
+thermal emittance by C. Schroeder et al, has been used to predict the beam
+normalised emittance obtainable with those schemes. In this manuscript we
+recast and extend such a theory, including both higher order terms in the
+polinomial laser field expansion and non polinomial corrections due to the
+onset of saturation effects in a single cycle. Also, a very accurate model for
+predicting the cycle-averaged $3D$ momentum distribution of the extracted
+electrons, including saturation and multi-process events, is proposed and
+tested. We show that our theory is very accurate for the selected processes of
+Kr$^{8^+\rightarrow10^+}$ and Ar$^{8^+\rightarrow10^+}$, resulting in a a
+maximum error below $1\%$ even in deep saturation regime. This highly accurate
+prediction of the beam phase-space can be implemented e.g., in laser-envelope
+Particle in Cell (PIC) or hybrid PIC-fluid codes, to correctly mimic the
+cycle-averaged momentum distribution without the need of resolving the
+intra-cycle dynamics. Finally, we introduce further spatial averaging with
+Gaussian longitudinal and transverse laser profiles, obtaining expressions for
+the whole-beam emittance that fits with Monte Carlo simulations in a saturated
+regime, too.",2108.13044v2
+2021-10-25,A Nearly Optimal Chattering Reduction Method of Sliding Mode Control With an Application to a Two-wheeled Mobile Robot,"The problem we focus on in this paper is to find a nearly optimal sliding
+mode controller of continuous-time nonlinear multiple-input multiple-output
+(MIMO) systems that can both reduce chattering and minimize the cost function,
+which is a measure of the performance index of dynamics systems. First, the
+deficiency of chattering in traditional SMC and the quasi-SMC method are
+analyzed in this paper. In quasi-SMC, the signum function of the traditional
+SMC is replaced with a continuous saturation function. Then, a chattering
+reduction algorithm based on integral reinforcement learning (IRL) is proposed.
+Under an initial sliding mode controller, the proposed method can learn the
+nearly optimal saturation function using policy iteration. To satisfy the
+requirement of the learned saturation function, we treat the problem of
+training the saturation function as the constraint of an optimization problem.
+The online neural network implementation of the proposed algorithm is presented
+based on symmetric radius basis functions and a regularized batch least-squares
+(BLS) algorithm to train the control law in this paper. Finally, two examples
+are simulated to verify the effectiveness of the proposed method. The second
+example is an application to a real-world dynamics model -- a two-wheeled
+variable structure robot.",2110.12706v1
+2021-12-20,Space-time upscaling of reactive transport in porous media,"Reactive transport in saturated/unsaturated porous media is numerically
+upscaled to the space-time scale of a hypothetical measurement through
+coarse-grained space-time (CGST) averages. The reactive transport is modeled at
+the fine-grained Darcy scale by the actual number of molecules involved in
+reactions which undergo advective and diffusive movements described by global
+random walk (GRW) simulations. The CGST averages verify identities similar to a
+local balance equation which allow us to derive expressions for the flow
+velocity and the intrinsic diffusion coefficient in terms of averaged
+microscopic quantities. The latter are further used to verify the CGST-GRW
+numerical approach. The upscaling approach is applied to biodegradation
+processes in saturated aquifers and variably saturated soils and the CGST
+averages are compared to classical volume averages. One finds that if the
+process is characterized by slow variations in time, as in homogeneous reaction
+systems, the differences between the two averages are negligible. Instead, the
+differences are significant and can be extremely large in simulations of
+time-dependent biodegradation processes in both soils and saturated aquifers.",2112.10692v5
+2021-12-27,Sharply doubly transitive groups with saturation conditions,"A number of conditions were found under which a sharply doubly transitive
+permutation group has an abelian normal divider.",2112.13526v2
+2021-12-30,Abstract key polynomials and distinguished pairs,"In this paper, for a henselian valued field $(K,v)$ of arbitrary rank and an
+extension $w$ of $v$ to $K(X),$ we use abstract key polynomials for $w$ to
+obtain distinguished pairs and saturated distinguished chains.",2112.15123v1
+2022-02-18,Detecting few-body quantum chaos: out-of-time ordered correlators at saturation,"We study numerically and analytically the time dependence and saturation of
+out-of-time ordered correlators (OTOC) in chaotic few-body quantum-mechanical
+systems: quantum Henon-Heiles system (weakly chaotic), BMN matrix quantum
+mechanics (strongly chaotic) and Gaussian random matrix ensembles. The growth
+pattern of quantum-mechanical OTOC is complex and nonuniversal, with no clear
+exponential regime at relevant timescales in any of the examples studied (which
+is not in contradiction to the exponential growth found in the literature for
+many-body systems, i.e. fields). On the other hand, the plateau (saturated)
+value of OTOC reached at long times decreases with temperature in a simple and
+universal way: $\exp(\mathrm{const.}/T^2)$ for strong chaos (including random
+matrices) and $\exp(\mathrm{const.}/T)$ for weak chaos. For small matrices and
+sufficiently complex operators, there is also another, high-temperature regime
+where the saturated OTOC grows with temperature. Therefore, the plateau OTOC
+value is a meaningful indicator of few-body quantum chaos. We also discuss some
+general consequences of our findings for the AdS/CFT duality.",2202.09443v3
+2022-03-28,Embedding short-range correlations in relativistic density functionals through quasi-deuterons,"The formation of clusters at sub-saturation densities constitutes an
+essential feature for a reliable modelization of the nuclear matter equation of
+state (EoS). Phenomenological models that make use of energy density
+functionals (EDFs) offer a convenient approach to account for the presence of
+these bound states of nucleons when introduced as additional degrees of
+freedom. However, in these models clusters dissolve, by construction, when the
+nuclear saturation density is approached from below, revealing inconsistencies
+with recent findings that evidence the existence of short-range correlations
+(SRCs) even at larger densities.
+  In this work, within the EDF framework, a novel approach is proposed to embed
+SRCs within a relativistic mean-field model with density dependent couplings.
+This is realized through the introduction of suitable in-medium modifications
+of the cluster binding energy shifts, which are responsible for describing the
+cluster dissolution. As a first exploratory step, the example of a
+quasi-deuteron within the generalized relativistic density functional approach
+is investigated.
+  For the first time, suitable parameterizations of the cluster mass shift at
+zero temperature are derived for all baryon densities. They are constrained by
+experimental results for the effective deuteron fraction in nuclear matter near
+saturation and by microscopic many-body calculations in the low-density limit.
+The strength of the deuteron-meson couplings is assessed to be of crucial
+importance. The findings of the present study represent a first step to improve
+the description of nuclear matter and its EoS at supra-saturation densities in
+EDFs by considering correlations in an effective way. Novel effects on some
+thermodynamic quantities, such as the matter incompressibility, the symmetry
+energy and its slope, are finally discerned and discussed.",2203.14635v1
+2022-04-24,A generalization of Alperin fusion theorem and its applications,"Let $\mathcal F$ be a saturated fusion system on a finite $p$-group $S$, and
+let $P$ be a strongly $\mathcal F$-closed subgroup of $S$. We define the
+concept ``$\mathcal F$-essential subgroups with respect to $P$"" which are some
+proper subgroups of $P$ satisfying some technical conditions, and show that an
+$\mathcal F$-isomorphism between subgroups of $P$ can be factorised by some
+automorphisms of $P$ and $\mathcal F$-essential subgroups with respect to $P$.
+When $P$ is taken to be equal $S$, Alperin-Goldschmidt fusion theorem can be
+obtained as a special case. We also show that $P\unlhd \mathcal F$ if and only
+if there is no $\mathcal F$-essential subgroup with respect to $P$. The
+following definition is made: a $p$-group $P$ is strongly resistant in
+saturated fusion systems if $P\unlhd \mathcal F$ whenever there is an over
+$p$-group $S$ and a saturated fusion system $\mathcal F$ on $S$ such that $P$
+is strongly $\mathcal F$-closed. It is shown that several classes of $p$-groups
+are strongly resistant, which appears as our third main theorem. We also give a
+new necessary and sufficient criteria for a strongly $\mathcal F$-closed
+subgroup to be normal in $\mathcal F$. These results are obtained as a
+consequences of developing a theory of quasi and semi-saturated fusion systems,
+which seems to be interesting for its own right.",2204.11303v2
+2022-06-07,On-Surface Synthesis of a Pure and Long-Range-Ordered Titanium(IV)-Porphyrin Contact Layer on Titanium Dioxide,"We show the possibility of tailoring the molecular arrangement, as well as
+the chemical and structural modifications, of porphyrins at the monolayer
+saturation coverage on TiO2(110) by Synchrotron photoemission, electron
+diffraction, STM topography and DFT calculations. Free-base
+tetra-phenyl-porphyrins (2H-TPP) adsorb on the oxygen rows, where they can
+spontaneously capture two additional hydrogen atoms at their iminic nitrogens
+(4H-TPP). Both 2H-TPP and 4H-TPP molecules aggregate into a commensurate phase
+at the saturation coverage of one monolayer. Upon sample heating, a
+self-metalation reaction sets in at 100C, yielding full metalation of the
+saturated monolayer at ~200C. The Ti atoms are extracted from the substrate
+and, by simultaneous dehydrogenation of the pyrrolic nitrogen atoms,
+incorporated into the porphyrin macrocycle, where they remain coordinated to
+two oxygen atoms underneath. Neither the adsorption geometry (on-bridge, atop
+the oxygen rows) nor the molecular arrangement change across the
+self-metalation transition up to 300C. On one side, the robustness of this
+saturation phase makes it a promising system for its implementation into
+applications for photocatalysis and photovoltaic devices. On the other side,
+the possible manifestation of metal exchange with the very reactive Ti atoms
+must be taken into account when designing porphyrin-sensitized solar cells
+since the critical temperature for the onset of self-metalation is very close
+to the normal operating temperature of photovoltaic devices.",2206.03175v2
+2022-07-23,Saturating the one-axis twisting quantum Cramér-Rao bound with a total spin readout,"We show that the lowest quantum Cram\'{e}r-Rao bound achievable in
+interferometry with a one-axis twisted spin coherent state is saturated by the
+asymptotic method of moments error of a protocol that uses one call to the
+one-axis twisting, one call to time-reversed one-axis twisting, and a final
+total spin measurement (i.e., a twist-untwist protocol). The result is derived
+by first showing that the metrological phase diagram for one-axis twisting is
+asymptotically characterized by a single quantum Fisher information value
+$N(N+1)/2$ for all times, then constructing a twist-untwist protocol having a
+method of moments error that saturates this value. The case of finite-range
+one-axis twisting is similarly analyzed, and a simple functional form for the
+metrological phase diagram is found in both the short-range and long-range
+interaction regimes. Numerical evidence suggests that the finite-range
+analogues of twist-untwist protocols can exhibit a method of moments error that
+asymptotically saturates the lowest quantum Cram\'{e}r-Rao bound achievable in
+interferometry with finite-range one-axis twisted spin coherent states for all
+interaction times.",2207.11462v3
+2022-09-28,Spiral instabilities: Mode saturation and decay,"This paper continues a series reporting different aspects of the behaviour of
+disc galaxy simulations that support spiral instabilities. The focus in this
+paper is to demonstrate how linear spiral instabilities saturate and decay, and
+how the properties of the disc affect the limiting amplitude of the spirals.
+Once again, we employ idealized models that each possess a single instability
+that we follow until it has run its course. Remarkably, we find a tight
+correlation between the growth rate of the mode and its limiting amplitude,
+albeit from only six simulations. We show that non-linear orbit deflections
+near corotation cause the mode to saturate, and that the more time available in
+a slowly-growing mode creates the critical deflections at lower amplitude. We
+also find that scattering at the inner Lindblad resonance is insignificant
+until after the mode has saturated. Our objective in this series of papers,
+which we believe we have now achieved, has been to develop a convincing and
+well-documented account of the physical behaviour of the spiral patterns that
+have been observed in simulations by others, and by ourselves, for many
+decades. Understanding the simulations is an important step towards the greater
+objective, which is to find observational evidence from galaxies that could
+confront the identified mechanism.",2209.14256v2
+2022-10-01,Spontaneous symmetry breaking and ghost states supported by the fractional nonlinear Schrödinger equation with focusing saturable nonlinearity and PT-symmetric potential,"We report a novel spontaneous symmetry breaking phenomenon and ghost states
+existed in the framework of the fractional nonlinear Schr\""odinger (FNLS)
+equation with focusing saturable nonlinearity and PT-symmetric potential. The
+continuous asymmetric soliton branch bifurcates from the fundamental symmetric
+one as the power exceeds some critical value. Intriguingly, the symmetry of
+fundamental solitons is broken into two branches of asymmetry solitons (alias
+ghost states) with complex conjugate propagation constants, which is solely in
+fractional media. Besides, the dipole (antisymmetry) and tripole solitons are
+also studied numerically. Moreover, we analyze the influences of fractional
+L\'evy index and saturable nonlinear parameters on the symmetry breaking of
+solitons in detail. And the stability of fundamental soliton, asymmetric,
+dipole and tripole solitons are explored via the linear stability analysis and
+direct propagations. Moreover, we explore the elastic/semi-elastic collision
+phenomena between symmetric and asymmetric solitons. Meanwhile, we find the
+stable excitations from the fractional diffraction with saturation nonlinearity
+to integer-order diffraction with Kerr nonlinearity via the adiabatic
+excitations of parameters. These results will provide some theoretical basis
+for the study of spontaneous symmetry breaking phenomena and related physical
+experiments in the fractional media with PT-symmetric potentials.",2210.00277v1
+2022-10-18,Effective Constitutive Relations for Simulating CO2 Capillary Trapping in Heterogeneous Reservoirs with Fluvial Sedimentary Architecture,"Carbon dioxide (CO2) storage reservoirs commonly exhibit sedimentary
+architecture that reflects fluvial deposition. The heterogeneity in
+petrophysical properties arising from this architecture influences the dynamics
+of injected CO2. We previously used a geocellular modeling approach to
+represent this heterogeneity, including heterogeneity in constitutive
+saturation relationships. The dynamics of CO2 plumes in fluvial reservoirs was
+investigated during and after injection. It was shown that small-scale
+(centimeter to meter) features play a critical role in capillary trapping
+processes and have a primary effect on physical- and dissolution-trapping of
+CO2, and on the ultimate distribution of CO2 in the reservoir. Heterogeneity in
+saturation functions at that small scale enhances capillary trapping (snap
+off), creates capillary pinning, and increases the surface area of the plume.
+The understanding of these small-scale trapping processes from previous work is
+here used to develop effective saturation relationships that represent, at a
+larger scale, the integral effect of these processes. While it is generally not
+computationally feasible to represent the small-scale heterogeneity directly in
+a typical reservoir simulation, the effective saturation relationships for
+capillary pressure and relative permeability presented here, along with an
+effective intrinsic permeability, allow better representation of the total
+physical trapping at the scale of larger model grid cells, as typically used in
+reservoir simulations, and thus the approach diminishes limits on cell size and
+decreases simulation time in reservoir simulations.",2210.10124v1
+2022-10-19,Control Design under Actuator Saturation and Multi-Rate Sampling,"The problem of designing a stabilizing feedback controller in the presence of
+saturating actuators and multi-rate (asynchronous) aperiodic state measurements
+is studied. Specifically, we consider a scenario in which measurements of the
+plant states are collected at the controller end in a sporadic and asynchronous
+fashion. A hybrid controller is used to perform a fusion of measurements
+sampled at different times. In between sampling events, the controller behaves
+as a copy of the plant and provides a feedback control signal based on the
+reconstruction of the plant state. The presence of saturation at the plant
+input limits the value of the components of this signal to a bounded range.
+When a new measurement is available, the controller state undergoes an
+instantaneous jump. The resulting system is augmented with a set of timers
+triggering the arrival of new measurements and analyzed in a hybrid systems
+framework. Relying on Lyapunov tools for hybrid systems and techniques for
+control design under saturation, we propose sufficient conditions in the form
+of matrix inequalities to ensure regional exponential stability of a closed-set
+containing the origin of the plant, i.e., exponential stability with a
+guaranteed region of attraction. Specifically, explicit estimates of the basin
+of attraction are provided in the form of ellipsoidal sets. Leveraging those
+conditions, a design procedure based on semidefinite programming is proposed to
+design a stabilizing controller with maximized size of the basin attraction.
+The effectiveness of the proposed methodology is shown in an example.",2210.10868v1
+2022-10-21,Neutron star mass formula with nuclear saturation parameters for asymmetric nuclear matter,"Low-mass neutron stars are directly associated with the nuclear saturation
+parameters because their central density is definitely low. We have already
+found a suitable combination of nuclear saturation parameters for expressing
+the neutron star mass and gravitational redshift, i.e., $\eta\equiv
+(K_0L^2)^{1/3}$ with the incompressibility for symmetric nuclear matter, $K_0$,
+and the density-dependent nuclear symmetry energy, $L$. In this study, we newly
+find another suitable combination given by $\eta_\tau\equiv (-K_\tau
+L^5)^{1/6}$ with the isospin dependence of incompressibility for asymmetric
+nuclear matter, $K_\tau$, and derive the empirical relations for the neutron
+star mass and gravitational redshift as a function of $\eta_\tau$ and the
+normalized central number density. With these empirical relations, one can
+evaluate the mass and gravitational redshift of the neutron star, whose central
+number density is less than threefold the saturation density, within $\sim
+10\%$ accuracy, and the radius within a few \% accuracies. In addition, we
+discuss the neutron star mass and radius constraints from the terrestrial
+experiments, using the empirical relations, together with those from the
+astronomical observations. Furthermore, we find a tight correlation between
+$\eta_\tau$ and $\eta$. With this correlation, we derive the constraint on
+$K_\tau$ as $-348\le K_\tau\le -237$ MeV, assuming that $L=60\pm 20$ and
+$K_0=240\pm 20$ MeV.",2210.11651v1
+2022-11-11,Continuum kinetic investigation of the impact of bias potentials in the current saturation regime on sheath formation,"In this work, we examine sheath formation in the presence of bias potentials
+in the current saturation regime for pulsed power fusion experiments. It is
+important to understand how the particle and heat fluxes at the wall may impact
+the wall material and affect electrode degradation. Simulations are performed
+using the 1X-1V Boltzmann-Poisson system for a proton-electron plasma in the
+presence of bias potentials ranging from 0 to 10 kV. The results indicate that
+the sheath near the high potential wall remains generally the same as that of a
+classical sheath without the presence of a bias potential. However, the sheath
+near the low potential wall becomes more prominent with a larger potential
+drop, a significant decrease of electron density, and larger sheath lengths.
+The spatially constant current density increases to a saturation value with
+increasing bias potential. The current is dominated by the ions at the low
+potential wall and by the electrons at the high potential wall. The heat flux
+increases to a saturation value at the high potential wall and tends to zero at
+the low potential wall with increasing bias potential. The results trend with
+theory with differences attributed to the simplified assumptions in the theory
+and the kinetic effects considered in the simulations. Due to the significant
+computational cost of a well resolved 1X-2V simulation, only one such
+simulation is performed for the 5 kV case showing higher current.",2211.06488v3
+2022-12-06,"A symmetric chain decomposition of $L(5,n)$","We give a constructive proof that Young's lattice $L(5, n)$ has a partition
+into saturated symmetric chains.",2212.02700v4
+2022-12-20,The Effects of Connectivity and Automation on Saturation Headway and Capacity at Signalized Intersections,"This paper analyzes the potential effects of connected and automated vehicles
+on saturation headway and capacity at signalized intersections. A signalized
+intersection is created in Vissim as a testbed, where four vehicle types are
+modeled and tested: (I) human-driven vehicles (HVs), (II) connected vehicles
+(CVs), (III) automated vehicles (AVs), and (IV) connected automated vehicles
+(CAVs). Various scenarios are defined based on different market penetration
+rates of these four vehicle types. AVs are assumed to move more cautiously
+compared to human drivers. CVs and CAVs are supposed to receive information
+about the future state of traffic lights and adjust their speeds to avoid
+stopping at the intersection. As a result, their movements are expected to be
+smoother with a lower number of stops. The effects of these vehicle types in
+mixed traffic are investigated in terms of saturation headway, capacity, travel
+time, delay, and queue length in different lane groups of an intersection. A
+Python script code developed by Vissim is used to provide the communication
+between the signal controller and CVs and CAVs to adjust their speeds
+accordingly. The results show that increasing CV and CAV market penetration
+rate reduces saturation headway and consequently increases capacity at
+signalized intersections. On the other hand, increasing the AV market
+penetration rate deteriorates traffic operations. Results also indicate that
+the highest increase (80%) and decrease (20%) in lane group capacity are
+observed, respectively, in a traffic stream of 100% CAVs and 100% AVs.",2212.09986v1
+2022-12-22,Low intensity saturation of an ISB transition by a mid-IR quantum cascade laser,"We demonstrate that absorption saturation of a mid-infrared intersubband
+transition can be engineered to occur at moderate light intensities of the
+order of 10-20 kW$.$cm$^{-2}$ and at room temperature. The structure consists
+of an array of metal-semiconductor-metal patches hosting a judiciously designed
+253 nm thick GaAs/AlGaAs semiconductor heterostructure. At low incident
+intensity the structure operates in the strong light-matter coupling regime and
+exhibits two absorption peaks at wavelengths close to 8.9 $\mu$m. Saturation
+appears as a transition to the weak coupling regime - and therefore to a
+single-peaked absorption - when increasing the incident intensity. Comparison
+with a coupled mode theory model explains the data and permits to infer the
+relevant system parameters. When the pump laser is tuned at the cavity
+frequency, the reflectivity decreases with increasing incident intensity. When
+instead the laser is tuned at the polariton frequencies, the reflectivity
+non-linearly increases with increasing incident intensity. At those wavelengths
+the system therefore mimics the behavior of a saturable absorption mirror
+(SESAM) in the mid-IR range, a technology that is currently missing.",2212.11641v3
+2023-01-02,Examination of saturation coverage of short polymers using random sequential adsorption algorithm,"We filled a void with a regular or asymmetric pattern without overlap using a
+time-dependent packing method termed random sequential adsorption (RSA). In the
+infinite-time limit, the density of coverage frequently hits a limit. This
+study focused on the saturation packing of squares and their dimers, trimers,
+tetramers, pentamers, and hexamers, all of which were orientated in two
+randomly chosen orientations (vertical and horizontal). Our results concurred
+with those of previous extrapolation-based research1. We used the ""separating
+axis theorem"" to detect if freshly added polygons and previously put ones
+overlapped. When RSA insertion became disproportionately sluggish, we concluded
+that saturation had been attained. We also discovered that the system's
+capacity to fill the area decreased as squares were stretched into dimers and
+trimmers. The microstructure of the resultant saturation was also thoroughly
+investigated, including block function and the structural arrangement of dimers
+and trimers. Based on results of ref2, it is predicted that layer adsorbed onto
+a substrate will not hinder diffusion. Moreover, it was found that the adsorbed
+rectangles' aspect ratio had an impact on the coverage percentage at the
+jamming limit, with aspect ratios of 2 (like dimers here) producing the highest
+jamming coverage. As a result, the current results are a more in-depth
+expansion of the report in reference3.",2301.00766v1
+2023-01-17,Dielectric Saturation in Water from a Long Range Machine Learning Model,"Machine learning-based neural network potentials have the ability to provide
+ab initio-level predictions while reaching large length and time scales often
+limited to empirical force fields. Traditionally, neural network potentials
+rely on a local description of atomic environments to achieve this scalability.
+These local descriptions result in short range models that neglect long range
+interactions necessary for processes like dielectric screening in polar
+liquids. Several approaches to including long range electrostatic interactions
+within neural network models have appeared recently, and here we investigate
+the transferability of one such model, the self consistent neural network
+(SCFNN), which focuses on learning the physics associated with long range
+response. By learning the essential physics, one can expect that such a neural
+network model should exhibit at least partial transferability. We illustrate
+this transferability by modeling dielectric saturation in a SCFNN model of
+water. We show that the SCFNN model can predict non-linear response at high
+electric fields, including saturation of the dielectric constant, without
+training the model on these high field strengths and the resulting liquid
+configurations. We then use these simulations to examine the nuclear and
+electronic structure changes underlying dielectric saturation. Our results
+suggest that neural network models can exhibit transferability beyond the
+linear response regime and make genuine predictions when the relevant physics
+is properly learned.",2301.07188v1
+2023-03-18,Constitutive theory of saturated porous media considering porosity-dependent skeleton strain and chemical activity,"In order to reveal the coupling effect among the chemical activity and the
+hydraulic seepage as well as the mechanical properties, a constitutive
+theoretical framework considering the chemical activity for saturated porous
+media is derived from the mixture theory incorporated with the chemical
+thermodynamics. First, to highlight the important role of porosity in the
+hydro-mechanical-chemical multi-field coupling mechanism, the solid strain is
+divided into the porosity-dependent skeleton strain, the matrix strain and the
+mass-exchange strain. The stress and strain state variables are determined from
+the energy-conjugated form of the energy balance equation for establishing
+constitutive equations. Second, under infinitesimal case, general elastic
+constitutive equations including the relationship between mass fraction and its
+chemical potential are expressed by the free energy potential. Plastic model
+and the constitutive equation of thermodynamic flux and force are derived from
+the dissipative potential. Finally, under the guide of this theoretical
+framework, the complete swelling constitutive models in the confined
+compression are established for bentonite. The corresponding governing
+equations are formulated for multi-field two-phase saturated porous media.
+Compared with the experimental data, the proposed model can well reflect the
+chemical and mechanic coupling characteristics of representative elementary
+volume in the different NaCl concentrations of solution for saturated
+bentonite.",2303.10374v1
+2023-03-28,Globally Intelligent Adaptive Finite-/Fixed- Time Tracking Control for Strict-Feedback Nonlinear Systems via Composite Learning Approaches,"This article focuses on the globally composite adaptive law-based intelligent
+finite-/fixed- time (FnT/FxT) tracking control issue for a family of uncertain
+strict-feedback nonlinear systems. First, intelligent approximators with new
+composite updating laws are developed to model uncertain nonlinear terms, which
+encompass prediction errors to enhance intelligent approximators' learning
+behaviors and fewer online learning parameters to diminish computational
+burden. Then, a novel smooth switching function coupled with robust controllers
+is designed to pull system states back when the transients are out of the
+approximators' active domain. After that, a modified FnT/FxT backstepping
+technique is constructed to render output to follow the reference trajectory,
+and an adaptive law is employed to alleviate the impact of external
+disturbances. Moreover, input nonlinearities are considered in the design of
+control laws. In view of the known actuator magnitude and rate saturations, a
+novel adaptive fast FxT auxiliary variable system is established to effectively
+diminish saturation time, and further alleviate the impact of the auxiliary
+signal on the tracking error. Furthermore, when the input is subject to unknown
+magnitude saturation, rate saturation and dead-zone simultaneously, a smooth
+function is introduced to approximate the non-smooth input nonlinearities,
+where the unknown parameters are modeled via the presented global intelligent
+approximators. It is theoretically confirmed that the proposed control
+strategies ensure globally FnT/FxT boundedness of all the closed-loop
+variables. Finally, the validity of theoretical results is testified via a
+simulation case.",2303.15942v4
+2023-08-10,Deep Richardson-Lucy Deconvolution for Low-Light Image Deblurring,"Images taken under the low-light condition often contain blur and saturated
+pixels at the same time. Deblurring images with saturated pixels is quite
+challenging. Because of the limited dynamic range, the saturated pixels are
+usually clipped in the imaging process and thus cannot be modeled by the linear
+blur model. Previous methods use manually designed smooth functions to
+approximate the clipping procedure. Their deblurring processes often require
+empirically defined parameters, which may not be the optimal choices for
+different images. In this paper, we develop a data-driven approach to model the
+saturated pixels by a learned latent map. Based on the new model, the non-blind
+deblurring task can be formulated into a maximum a posterior (MAP) problem,
+which can be effectively solved by iteratively computing the latent map and the
+latent image. Specifically, the latent map is computed by learning from a map
+estimation network (MEN), and the latent image estimation process is
+implemented by a Richardson-Lucy (RL)-based updating scheme. To estimate
+high-quality deblurred images without amplified artifacts, we develop a prior
+estimation network (PEN) to obtain prior information, which is further
+integrated into the RL scheme. Experimental results demonstrate that the
+proposed method performs favorably against state-of-the-art algorithms both
+quantitatively and qualitatively on synthetic and real-world images.",2308.05543v1
+2023-08-18,Polarization-dependent Intensity Ratios in Double Resonance Spectroscopy,"Double Resonance is a powerful method spectroscopic method that provides an
+unambiguous assignment of the rigorous quantum numbers of one state of a
+transition. However, there is often ambiguity as to the branch ($\Delta J$) of
+the transition. The dependence of the intensity of the double resonance signal
+on the relative polarization of pump and probe radiation can be used to resolve
+this ambiguity and has been used for this in the past. However, the published
+theoretical predictions for this ratio are based upon a weak (i.e.
+non-saturating) field approximation. In this paper, we present theoretical
+predictions for these intensity ratios for cases where the pump field is
+strongly saturating, in the two limits of transitions dominated by homogeneous
+and inhomogeneous broadening. While saturation, as can be expected, reduces the
+magnitude of the polarization effect (driving the intensity ratio closer to
+unity), polarization anisotropy remains even with a strongly saturating probe
+field in most cases. For the case of an inhomogeneously broadened line, as when
+Doppler broadening linewidth dominates over even the power broadened
+homogeneous line width, a large fraction of the low pump power anisotropy
+remains. Results are presented for both the case of linear and circular pump
+and probe field polarizations. The present predictions are compared with
+experimental measurements on CH$_4$ ground state $\rightarrow \nu_3 \rightarrow
+3\nu_3$ transitions recently reported by de Oliveira et al and found to be in
+better agreement than the weak field predictions.",2308.09828v1
+2023-09-01,The Power of Patents: Leveraging Text Mining and Social Network Analysis to Forecast IoT Trends,"Technology has become an indispensable competitive tool as science and
+technology have progressed throughout history. Organizations can compete on an
+equal footing by implementing technology appropriately. Technology trends or
+technology lifecycles begin during the initiation phase. Finally, it reaches
+saturation after entering the maturity phase. As technology reaches saturation,
+it will be removed or replaced by another. This makes investing in technologies
+during this phase unjustifiable. Technology forecasting is a critical tool for
+research and development to determine the future direction of technology. Based
+on registered patents, this study examined the trends of IOT technologies. A
+total of 3697 patents related to the Internet of Things from the last six years
+of patenting have been gathered using lens.org for this purpose. The main
+people and companies were identified through the creation of the IOT patent
+registration cooperation network, and the main groups active in patent
+registration were identified by the community detection technique. The patents
+were then divided into six technology categories: Safety and Security,
+Information Services, Public Safety and Environment Monitoring, Collaborative
+Aware Systems, Smart Homes/Buildings, and Smart Grid. And their technical
+maturity was identified and examined using the Sigma Plot program. Based on the
+findings, information services technologies are in the saturation stage, while
+both smart homes/buildings, and smart grid technologies are in the saturation
+stage. Three technologies, Safety and Security, Public Safety and Environment
+Monitoring, and Collaborative Aware Systems are in the maturity stage.",2309.00707v1
+2023-10-05,History Matching for Geological Carbon Storage using Data-Space Inversion with Spatio-Temporal Data Parameterization,"History matching based on monitoring data will enable uncertainty reduction,
+and thus improved aquifer management, in industrial-scale carbon storage
+operations. In traditional model-based data assimilation, geomodel parameters
+are modified to force agreement between flow simulation results and
+observations. In data-space inversion (DSI), history-matched quantities of
+interest, e.g., posterior pressure and saturation fields conditioned to
+observations, are inferred directly, without constructing posterior geomodels.
+This is accomplished efficiently using a set of O(1000) prior simulation
+results, data parameterization, and posterior sampling within a Bayesian
+setting. In this study, we develop and implement (in DSI) a deep-learning-based
+parameterization to represent spatio-temporal pressure and CO2 saturation
+fields at a set of time steps. The new parameterization uses an adversarial
+autoencoder (AAE) for dimension reduction and a convolutional long short-term
+memory (convLSTM) network to represent the spatial distribution and temporal
+evolution of the pressure and saturation fields. This parameterization is used
+with an ensemble smoother with multiple data assimilation (ESMDA) in the DSI
+framework to enable posterior predictions. A realistic 3D system characterized
+by prior geological realizations drawn from a range of geological scenarios is
+considered. A local grid refinement procedure is introduced to estimate the
+error covariance term that appears in the history matching formulation.
+Extensive history matching results are presented for various quantities, for
+multiple synthetic true models. Substantial uncertainty reduction in posterior
+pressure and saturation fields is achieved in all cases. The framework is
+applied to efficiently provide posterior predictions for a range of error
+covariance specifications. Such an assessment would be expensive using a
+model-based approach.",2310.03228v1
+2023-10-11,Saturation-Aware Angular Velocity Estimation: Extending the Robustness of SLAM to Aggressive Motions,"We propose a novel angular velocity estimation method to increase the
+robustness of Simultaneous Localization And Mapping (SLAM) algorithms against
+gyroscope saturations induced by aggressive motions. Field robotics expose
+robots to various hazards, including steep terrains, landslides, and
+staircases, where substantial accelerations and angular velocities can occur if
+the robot loses stability and tumbles. These extreme motions can saturate
+sensor measurements, especially gyroscopes, which are the first sensors to
+become inoperative. While the structural integrity of the robot is at risk, the
+resilience of the SLAM framework is oftentimes given little consideration.
+Consequently, even if the robot is physically capable of continuing the
+mission, its operation will be compromised due to a corrupted representation of
+the world. Regarding this problem, we propose a way to estimate the angular
+velocity using accelerometers during extreme rotations caused by tumbling. We
+show that our method reduces the median localization error by 71.5 % in
+translation and 65.5 % in rotation and reduces the number of SLAM failures by
+73.3 % on the collected data. We also propose the Tumbling-Induced Gyroscope
+Saturation (TIGS) dataset, which consists of outdoor experiments recording the
+motion of a lidar subject to angular velocities four times higher than other
+available datasets. The dataset is available online at
+https://github.com/norlab-ulaval/Norlab_wiki/wiki/TIGS-Dataset.",2310.07844v1
+2023-11-08,CGC/saturation approach: Impact-parameter dependent model in next-to-leading order and combined HERA data,"In this paper we confront the next-to-leading order (NLO) CGC/saturation
+approach of Ref. [1] with the experimental combined HERA data and obtain its
+parameters. The model includes two features that are in accordance with our
+theoretical knowledge of deep inelastic scattering. These consist of: $i$) the
+use of analytical solution for the non-linear Balitsky-Kovchegov (BK) evolution
+equation and $ii$) the exponential behavior of the saturation momentum on the
+impact parameter $b$-dependence, characterized by $Q_s$ $\propto\exp( -m b )$
+which reproduce the correct behaviour of the scattering amplitude at large $b$
+in accord with Froissart theorem. The model results are then compared to data
+at small-x for the structure function of the proton $F_{2}$, the longitudinal
+structure function $F_{L}$, the charm structure function $F_2^{c\bar{c}}$, the
+exclusive vector meson ($J/\psi,\phi,\rho$) production and Deeply Virtual
+Compton Scattering (DVCS). We obtain a good agreement for the processes in a
+wide kinematic range of $Q^2$ at small $x$. Our results provide a strong guide
+for finding an approach, based on Color Glass Condensate/saturation effective
+theory for high energy QCD, to make reliable predictions from first principles
+as well as for forthcoming experiments like the Electron-Ion Collider and the
+LHeC.",2311.06406v1
+2024-01-24,Echeloned saturation and forcing axioms,"Addressing a question of Paul Larson we prove the following statement. If
+Chang's conjecture fails, Martin's axiom holds and the continuum is greater
+than $\aleph_2$, there are no weakly Laver ideals over $\aleph_1$. We also
+prove that under Baumgartner's axiom there are no Laver ideals over $\aleph_2$.",2401.13364v1
+2024-02-29,The Influence of Color Stimuli on Adolescents' Emotion Playing Mobile Games,"Video games elicit emotions which can be influenced by color stimuli as shown
+by previous studies. However, little research has been conducted on whether
+this applies to mobile games played by adolescents. Therefore, we examined the
+influence of color stimuli hue and saturation on mobile game play. Adolescents
+(n=21) played a mobile platformer game with varying hue and saturation per
+level for about 25 minutes. We gathered data on emotional states after each
+level using the Self-Assessment Manikin questionnaire, recorded time spent in
+each level, and collected participant self-reports on their video game
+experience. We performed statistical tests, such as ANOVA, which depict no
+significant influence of hue and/or saturation on the emotional state of our
+players. We conclude that it is possible that color alone is not an effective
+measure for eliciting emotion in mobile games, and further research is needed
+to consider measures such as time spent in the game and screen size, as these
+are unique to mobile games. There was a noticeable variance in emotional
+response between male and female players, with a significant interaction of hue
+and saturation among male players for valence ratings. This may be an
+indication that color preference influences perceived pleasantness.",2402.19064v1
+2024-02-29,"Simple, High Saturation Power, Quantum-limited, RF SQUID Array-based Josephson Parametric Amplifiers","High-fidelity quantum non-demolition qubit measurement is critical to error
+correction and rapid qubit feedback in large-scale quantum computing.
+High-fidelity readout requires passing a short and strong pulse through the
+qubit's readout resonator, which is then processed by a sufficiently high
+bandwidth, high saturation power, and quantum-limited amplifier. We have
+developed a design pipeline that combines time-domain simulation of the
+un-truncated device Hamiltonian, fabrication constraints, and maximization of
+saturation power. We have realized an amplifier based on a modified NIST
+tri-layer Nb fabrication suite which utilizes an array of 25 radio frequency
+Superconducting QUantum Interference Devices (rf SQUIDs) embedded within a
+low-Q resonator powered by a high-power voltage pump delivered via a diplexer
+on the signal port. We show that, despite the intensity of the pump, the device
+is quantum-efficient and capable of high-fidelity measurement limited by state
+transitions in the transmon. We present experimental data demonstrating up to
+-91.2 dBm input saturation power with 20 dB gain, up to 28 MHz instantaneous
+bandwidth, and phase-preserving qubit measurements with 62% quantum efficiency.",2402.19435v1
+2003-05-24,Correlation between the Mean Matter Density and the Width of the Saturated Lyman Alpha Absorption,"We report a scaling of the mean matter density with the width of the
+saturated Lyman alpha absorptions. This property is established using the
+``pseudo-hydro'' technique (Croft et al. 1998). It provides a constraint for
+the inversion of the Lyman alpha forest, which encounters difficulty in the
+saturated region. With a Gaussian density profile and the scaling relation, a
+simple inversion of the simulated Lyman alpha forests shows that the
+one-dimensional mass power spectrum is well recovered on scales above 2 Mpc/h,
+or roughly k < 0.03 s/km, at z=3. The recovery underestimates the power on
+small scales, but improvement is possible with a more sophisticated algorithm.",0305481v2
+1999-09-29,Universality and saturation of intermittency in passive scalar turbulence,"The statistical properties of a scalar field advected by the non-intermittent
+Navier-Stokes flow arising from a two-dimensional inverse energy cascade are
+investigated. The universality properties of the scalar field are directly
+probed by comparing the results obtained with two different types of injection
+mechanisms. Scaling properties are shown to be universal, even though
+anisotropies injected at large scales persist down to the smallest scales and
+local isotropy is not fully restored. Scalar statistics is strongly
+intermittent and scaling exponents saturate to a constant for sufficiently high
+orders. This is observed also for the advection by a velocity field rapidly
+changing in time, pointing to the genericity of the phenomenon. The persistence
+of anisotropies and the saturation are both statistical signatures of the
+ramp-and-cliff structures observed in the scalar field.",9909038v1
+1996-11-25,The three species monomer-monomer model: A mean-field analysis and Monte Carlo study,"We study the phase diagram and critical behavior of a one dimensional three
+species monomer-monomer surface reaction model. Static Monte Carlo simulations
+show a phase diagram consisting of a reactive steady state bordered by three
+equivalent unreactive phases where the surface is saturated with one monomer
+species. The transitions from the reactive to saturated phases are all
+continuous, while the transitions between poisoned phases are first-order, with
+bicritical points where the reactive phase meets two poisoned phases. A
+mean-field cluster analysis predicts all of the qualitative features of the
+phase diagram only when correlations up to triplets of adjacent sites are
+included. Dynamic Monte Carlo simulations show that the transition from the
+reactive to a saturated phase show critical behavior in the directed
+percolation universality class, while the bicritical point shows critical
+behavior in the even branching annihilating random walk class. The crossover
+from bicritical to critical behavior is also studied.",9611197v1
+1997-12-26,Critical behavior of a one-dimensional monomer-dimer reaction model with lateral interactions,"A monomer-dimer reaction lattice model with lateral repulsion among the same
+species is studied using a mean-field analysis and Monte Carlo simulations. For
+weak repulsions, the model exhibits a first-order irreversible phase transition
+between two absorbing states saturated by each different species. Increasing
+the repulsion, a reactive stationary state appears in addition to the saturated
+states. The irreversible phase transitions from the reactive phase to any of
+the saturated states are continuous and belong to the directed percolation
+universality class. However, a different critical behavior is found at the
+point where the directed percolation phase boundaries meet. The values of the
+critical exponents calculated at the bicritical point are in good agreement
+with the exponents corresponding to the parity-conserving universality class.
+Since the adsorption-reaction processes does not lead to a non-trivial local
+parity-conserving dynamics, this result confirms that the twofold symmetry
+between absorbing states plays a relevant role in determining the universality
+class. The value of the exponent $\delta_2$, which characterizes the
+fluctuations of an interface at the bicritical point, supports the
+Bassler-Brown's conjecture which states that this is a new exponent in the
+parity-conserving universality class.",9712301v2
+1999-04-20,Low-Temperature Saturation of the Dephasing Time and Effects of Microwave Radiation on Open Quantum Dots,"The dephasing time of electrons in open semiconductor quantum dots, measured
+using ballistic weak localization, is found to saturate below ~ 100 mK, roughly
+twice the electron base temperature, independent of dot size. Microwave
+radiation deliberately coupled to the dots affects quantum interference
+indistinguishably from elevated temperature, suggesting that direct dephasing
+due to radiation is not the cause of the observed saturation. Coulomb blockade
+measurements show that the applied microwaves create sufficient source drain
+voltages to account for dephasing due to Joule heating.",9904274v1
+2001-01-24,A Continuum Saltation Model for Sand Dunes,"We derive a phenomenological continuum saltation model for aeolian sand
+transport that can serve as an efficient tool for geomorphological
+applications. The coupled differential equations for the average density and
+velocity of sand in the saltation layer reproduce both known equilibrium
+relations for the sand flux and the time evolution of the sand flux as
+predicted by microscopic saltation models. The three phenomenological
+parameters of the model are a reference height for the grain-air interaction,
+an effective restitution coefficient for the grain-bed interaction, and a
+multiplication factor characterizing the chain reaction caused by the impacts
+leading to a typical time or length scale of the saturation transients. We
+determine the values of these parameters by comparing our model with wind
+tunnel measurements. Our main interest are out of equilibrium situations where
+saturation transients are important, for instance at phase boundaries
+(ground/sand) or under unsteady wind conditions. We point out that saturation
+transients are indispensable for a proper description of sand flux over
+structured terrain, by applying the model to the windward side of an isolated
+dune, thereby resolving recently reported discrepancies between field
+measurements and theoretical predictions.",0101377v2
+2001-09-25,Three dimensional hysdrodynamic lattice-gas simulations of binary immiscible and ternary amphiphilic flow through porous media,"We report the results of a study of multiphase flow in porous media. A
+Darcy's law for steady multiphase flow was investigated for both binary and
+ternary amphiphilic flow. Linear flux-forcing relationships satisfying Onsager
+reciprocity were shown to be a good approximation of the simulation data. The
+dependence of the relative permeability coefficients on water saturation was
+investigated and showed good qualitative agreement with experimental data.
+Non-steady state invasion flows were investigated, with particular interest in
+the asymptotic residual oil saturation. The addition of surfactant to the
+invasive fluid was shown to significantly reduce the residual oil saturation.",0109474v1
+2003-11-11,Solution of a statistical mechanics model for pulse formation in lasers,"We present a rigorous statistical-mechanics theory of nonlinear many mode
+laser systems. An important example is the passively mode-locked laser that
+promotes pulse operation when a saturable absorber is placed in the cavity. It
+was shown by Gordon and Fischer [1] that pulse formation is a first-order phase
+transition of spontaneous ordering of modes in an effective ""thermodynamic""
+system, in which intracavity noise level is the effective temperature. In this
+paper we present a rigorous solution of a model of passive mode locking. We
+show that the thermodynamics depends on a single parameter, and calculate
+exactly the mode-locking point. We find the phase diagram and calculate
+statistical quantities, including the dependence of the intracavity power on
+the gain saturation function, and finite size corrections near the transition
+point. We show that the thermodynamics is independent of the gain saturation
+mechanism and that it is correctly reproduced by a mean field calculation. The
+outcome is a new solvable statistical mechanics system with an unstable
+self-interaction accompanied by a natural global power constraint, and an exact
+description of an important many mode laser system.",0311241v1
+2004-01-05,Electron-Electron Interactions in Isolated and Realistic Quantum Dots: A Density Functional Theory Study,"We use Kohn-Sham spin-density-functional theory to study the statistics of
+ground-state spin and the spacing between conductance peaks in the Coulomb
+blockade regime for both 2D isolated and realistic quantum dots. We make a
+systematic investigation of the effects of electron-electron interaction
+strength and electron number on both the peak spacing and spin distributions. A
+direct comparison between the distributions from isolated and realistic dots
+shows that, despite the difference in the boundary conditions and confining
+potential, the statistical properties are qualitatively the same. Strong
+even/odd pairing in the peak spacing distribution is observed only in the weak
+e-e interaction regime and vanishes for moderate interactions. The probability
+of high spin ground states increases for stronger e-e interaction and seems to
+saturate around $r_s \sim 4$. The saturated value is larger than previous
+theoretical predictions. Both spin and conductance peak spacing distributions
+show substantial variation as the electron number increases, not saturating
+until $N \sim 150$. To interpret our numerical results, we analyze the spin
+distribution in the even $N$ case using a simple two-level model.",0401043v1
+2004-01-12,Electron Dephasing in Mesoscopic Metal Wires,"The low-temperature behavior of the electron phase coherence time,
+$\tau_{\phi}$, in mesoscopic metal wires has been a subject of controversy
+recently. Whereas theory predicts that $\tau_{\phi}(T)$ in narrow wires should
+increase as $T^{-2/3}$ as the temperature $T$ is lowered, many samples exhibit
+a saturation of $\tau_{\phi}$ below about 1 K. We review here the experiments
+we have performed recently to address this issue. In particular we emphasize
+that in sufficiently pure Ag and Au samples we observe no saturation of
+$\tau_{\phi}$ down to our base temperature of 40 mK. In addition, the measured
+magnitude of $\tau_{\phi}$ is in excellent quantitative agreement with the
+prediction of the perturbative theory of Altshuler, Aronov and Khmelnitskii. We
+discuss possible explanations why saturation of $\tau_{\phi}$ is observed in
+many other samples measured in our laboratory and elsewhere, and answer the
+criticisms raised recently by Mohanty and Webb regarding our work.",0401182v1
+2004-02-03,Behavior of susceptible-infected-susceptible epidemics on heterogeneous networks with saturation,"We investigate saturation effects in susceptible-infected-susceptible (SIS)
+models of the spread of epidemics in heterogeneous populations. The structure
+of interactions in the population is represented by networks with connectivity
+distribution $P(k)$,including scale-free(SF) networks with power law
+distributions $P(k)\sim k^{-\gamma}$. Considering cases where the transmission
+of infection between nodes depends on their connectivity, we introduce a
+saturation function $C(k)$ which reduces the infection transmission rate
+$\lambda$ across an edge going from a node with high connectivity $k$. A mean
+field approximation with the neglect of degree-degree correlation then leads to
+a finite threshold $\lambda_{c}>0$ for SF networks with $2<\gamma \leq 3$. We
+also find, in this approximation, the fraction of infected individuals among
+those with degree $k$ for $\lambda$ close to $\lambda_{c}$. We investigate via
+computer simulation the contact process on a heterogeneous regular lattice and
+compare the results with those obtained from mean field theory with and without
+neglect of degree-degree correlations.",0402065v2
+2004-02-09,Lateral phase separation in mixtures of lipids and cholesterol systems,"In an effort to understand ``rafts'' in biological membranes, we propose
+phenomenological models for saturated and unsaturated lipid mixtures, and
+lipid-cholesterol mixtures. We consider simple couplings between the local
+composition and internal membrane structure, and their influence on transitions
+between liquid and ``gel'' membrane phases. Assuming that the gel transition
+temperature of the saturated lipid is shifted by the presence of the
+unsaturated lipid, and that cholesterol acts as an external field on the chain
+melting transition, a variety of phase diagrams are obtained. The phase
+diagrams for binary mixtures of saturated/unsaturated lipids and
+lipid/cholesterol are in semi-quantitative agreement with the experiments. Our
+results also apply to regions in the ternary phase diagram of
+lipid/lipid/cholesterol systems.",0402252v1
+2004-04-12,Universality of the Mott-Ioffe-Regel limit in metals,"The absence of resistivity saturation in many strongly correlated metals,
+including the high-temperature superconductors, is critically examined from the
+viewpoint of optical conductivity measurements. Coherent quasiparticle
+conductivity, in the form of a Drude peak centred at zero frequency, is found
+to disappear as the mean free path (at $\omega$ = 0) becomes comparable to the
+interatomic spacing. This basic loss of coherence at the so-called
+Mott-Ioffe-Regel (MIR) limit suggests that the universality of the MIR
+criterion is preserved even in the presence of strong electron correlations. We
+argue that the shedding of spectral weight at low frequencies, induced by
+strong correlation effects, is the primary origin of the extended positive
+slope of the resistivity to high temperatures observed in all so-called ""bad
+metals"". Moreover, in common with those metals which exhibit resistivity
+saturation at high temperatures, the scattering rate itself, as extracted from
+optical spectra, saturates at a value consistent with the MIR limit. We
+consider possible implications that this ceiling in the scattering rate may
+have for our understanding of transport within a wide variety of bad metals and
+suggest a better method for analysing their optical response.",0404263v1
+2005-06-29,Aeolian sans ripples: experimental study of saturated states,"We report an experimental investigation of aeolian sand ripples, performed
+both in a wind tunnel and on stoss slopes of dunes. Starting from a flat bed,
+we can identify three regimes: appearance of an initial wavelength, coarsening
+of the pattern and finally saturation of the ripples. We show that both initial
+and final wavelengths, as well as the propagative speed of the ripples, are
+linear functions of the wind velocity. Investigating the evolution of an
+initially corrugated bed, we exhibit non-linear stable solutions for a finite
+range of wavelengths, which demonstrates the existence of a saturation in
+amplitude. These results contradict most of the models.",0506758v2
+2005-11-24,Experiments on Corn Pressure in Silo Cells -- Translation and Comment of Janssen's Paper from 1895,"The German engineer H.A. Janssen gave one of the first accounts of the often
+peculiar behavior of granular material in a paper published in German in 1895.
+  From simple experiments with corn he inferred the saturation of pressure with
+height in a granular system. Subsequently, Janssen derived the equivalent of
+the barometric formula for granular material from the main assumption that the
+walls carry part of the weight. The following is a translation of this article.
+The wording is chosen as close as possible to the original. While drawings are
+copied from the original, figures displaying data are redone for better
+readability. The translation is complemented by some bibliographical notes and
+an assessment of earlier work, wherein Hagen predicted the saturation of
+pressure with depth in 1852, and Huber-Burnand demonstrated that saturation
+qualitatively as early as in 1829. We conclude with a brief discussion of more
+recent developments resting on Janssen's work.",0511618v1
+2006-06-13,"Interface relaxation in electrophoretic deposition of polymer chains: Effects of segmental dynamics, molecular weight, and field","Using different segmental dynamics and relaxation, characteristics of the
+interface growth is examined in an electrophoretic deposition of polymer chains
+on a three (2+1) dimensional discrete lattice with a Monte Carlo simulation.
+Incorporation of faster modes such as crankshaft and reptation movements along
+with the relatively slow kink-jump dynamics seems crucial in relaxing the
+interface width. As the continuously released polymer chains are driven (via
+segmental movements) and deposited, the interface width $W$ grows with the
+number of time steps $t$, $W \propto t^{\beta},$ ($\beta \sim 0.4$--$0.8)$,
+which is followed by its saturation to a steady-state value $W_s$. Stopping the
+release of additional chains after saturation while continuing the segmental
+movements relaxes the saturated width to an equilibrium value ($W_s \to W_r$).
+Scaling of the relaxed interface width $W_r$ with the driving field $E$, $W_r
+\propto E^{-1/2}$ remains similar to that of the steady-state $W_s$ width. In
+contrast to monotonic increase of the steady-state width $W_s$, the relaxed
+interface width $W_r$ is found to decay (possibly as a stretched exponential)
+with the molecular weight.",0606342v1
+2006-11-21,Peculiarities of the stacks with finite number of intrinsic Josephson junctions,"We study the breakpoint region on the outermost branch of current-voltage
+characteristics of the stacks with different number of intrinsic Josephson
+junctions. We show that at periodic boundary conditions the breakpoint region
+is absent for stacks with even number of junctions. For stacks with odd number
+of junctions and for stacks with nonperiodic boundary conditions the breakpoint
+current is increased with number of junctions and saturated at the value
+corresponding to the periodic boundary conditions. The region of saturation and
+the saturated value depend on the coupling between junctions. We explain the
+results by the parametric resonance at the breakpoint and excitation of the
+longitudinal plasma wave by the Josephson oscillations. A way for the
+diagnostics of the junctions in the stack is proposed.",0611555v2
+2007-03-06,Saturation of Spin-Polarized Current in Nanometer Scale Aluminum Grains,"We describe measurements of spin-polarized tunnelling via discrete energy
+levels of single Aluminum grains. In high resistance samples ($\sim G\Omega$),
+the spin-polarized tunnelling current rapidly saturates as a function of the
+bias voltage. This indicates that spin-polarized current is carried only via
+the ground state and the few lowest in energy excited states of the grain. At
+the saturation voltage, the spin-relaxation rate $T_1^{-1}$ of the highest
+excited states is comparable to the electron tunnelling rate: $T_1^{-1}\approx
+1.5\cdot 10^6 s^{-1}$ and $10^7s^{-1}$ in two samples. The ratio of $T_1^{-1}$
+to the electron-phonon relaxation rate is in agreement with the Elliot-Yafet
+scaling, an evidence that spin-relaxation in Al grains is governed by the
+spin-orbit interaction.",0703139v2
+2004-11-15,Nonlinear evolution of r-modes: the role of differential rotation,"Recent work has shown that differential rotation, producing large scale
+drifts of fluid elements along stellar latitudes, is an unavoidable feature of
+r-modes in the nonlinear theory. We investigate the role of this differential
+rotation in the evolution of the l=2 r-mode instability of a newly born, hot,
+rapidly rotating neutron star. It is shown that the amplitude of the r-mode
+saturates a few hundred seconds after the mode instability sets in. The
+saturation amplitude depends on the amount of differential rotation at the time
+the instability becomes active and can take values much smaller than unity. It
+is also shown that, independently of the saturation amplitude of the mode, the
+star spins down to rotation rates that are comparable to the inferred initial
+rotation rates of the fastest pulsars associated with supernova remnants.
+Finally, it is shown that, when the drift of fluid elements at the time the
+instability sets in is significant, most of the initial angular momentum of the
+star is transferred to the r-mode and, consequently, almost none is carried
+away by gravitational radiation.",0411072v1
+1997-04-21,Unitarity Corrections and High Field Strengths in High Energy Hard Collisions,"Unitarity corrections to the BFKL description of high energy hard scattering
+are viewed in large $N_c$ QCD in light-cone quantization. In a center of mass
+frame unitarity corrections to high energy hard scattering are manifestly
+perturbatively calculable and unrelated to questions of parton saturation. In a
+frame where one of the hadrons is initially at rest unitarity corrections are
+related to parton saturation effects and involve potential strengths $A_\mu
+\sim 1/g.$ In such a frame we describe the high energy scattering in terms of
+the expectation value of a Wilson loop. The large potentials $A_\mu \sim 1/g$
+are shown to be pure gauge terms allowing perturbation theory to again describe
+unitarity corrections and parton saturation effects. Genuine nonperturbative
+effects only come in at energies well beyond those energies where unitarity
+constraints first become important.",9704369v1
+1998-07-17,Saturating the Bound on the Scale of Fermion Mass Generation,"Recently, Jaeger and Willenbrock have shown that the Appelquist and Chanowitz
+bound on the scale of top-quark mass generation can formally be saturated in a
+particular limit of a two-Higgs doublet model. In this note I present an
+alternate derivation of their result. I perform a coupled channel analysis for
+f fbar to V_L V_L and V_L V_L to V_L V_L scattering and derive the conditions
+on the parameters required for f fbar to V_L V_L scattering to be relevant to
+unitarity. I also show that it is not possible to saturate the bound on fermion
+mass generation in the two-Higgs model while maintaining tree-level unitarity
+in Higgs scattering at high energies.",9807406v2
+2000-06-21,The Effective Pressure of a Saturated Gluon Plasma,"The evolution of the gluon plasma produced with saturation initial conditions
+is calculated via transport theory for nuclear collisions with 0.1 <sqrt(s) <10
+A TeV. The effective longitudinal pressure is found to remain significantly
+below the lattice QCD pressure with these initial conditions until the plasma
+cools to near the confinement scale. The absolute value of the transverse
+energy per unit of rapidity and its dependence on beam energy is shown to
+provide a sensitive test of gluon saturation models since the fractional
+transverse energy loss due to final state interactions is predicted to be much
+smaller and exhibit a weaker energy dependence than nondissipative
+hydrodynamics applied throughout the evolution.",0006257v2
+2001-04-11,Parton densities and saturation scale from non-linear evolution in DIS on nuclei,"We present the numerical solution of the non-linear evolution equation for
+DIS on nuclei for $x = 10^{-2} \div 10^{-7}$. We demonstrate that the solution
+to the non-linear evolution equation is quite different from the Glauber -
+Mueller formula which was used as the initial condition for the equation.
+  We illustrate the energy profit for performing DIS experiments on nuclei.
+  However, it turns out that the gain is quite modest: $x_{Au} \simeq 5 x_{\rm
+proton} $ for the same parton density.
+  We find that the saturation scale $Q^2_s \propto A^{{1/3}}$. For gold the
+saturation scale $Q_{s,Au} \simeq 1.5 GeV$ at $x= 10^{-3}$. Such a large value
+leads to considerable contribution of the high density QCD phase to RHIC data
+and reveals itself in essential damping for both $xG_A$ and $F_{2A}$.",0104108v1
+2002-03-22,Elliptic Flow from Minijet Production in Heavy Ion Collisions,"We calculate the contribution to the elliptic flow observable v2 from
+two-particle correlations in minijet production in ultrarelativistic heavy ion
+collisions. We use a minijet production cross section derived in a model
+inspired by saturation approach to high energy scattering. Resulting
+differential elliptic flow v2(pT) is an increasing function of pT for
+transverse momenta below the saturation scale Qs. At higher transverse momenta
+(pT > Qs) differential flow stops growing and becomes approximately constant,
+reproducing the elliptic flow saturation data reported by STAR. The centrality
+dependence of the minijet contribution to v2 is also in good agreement with the
+data.",0203213v4
+2002-07-03,Diffractive Hard Dijets and Nuclear Parton Distributions,"Diffraction plays an exceptional role in DIS off heavy nuclei. First,
+diffraction into hard dijets is an unique probe of the unintegrated glue in the
+target. Second, because diffraction makes 50 per cent of total DIS off a heavy
+target, understanding diffraction in a saturation regime is crucial for a
+definition of saturated nuclear parton densities. After brief comments on the
+Nikolaev-Zakharov (NZ) pomeron-splitting mechanism for diffractive hard dijet
+production, I review an extension of the Nikolaev-Schafer-Schwiete (NSS)
+analysis of diffractive dijet production off nuclei to the definition of
+nuclear partons in the saturation regime. I emphasize the importance of
+intranuclear final state interactions for the parton momentum distributions.",0207045v3
+2002-07-17,Saturation of Nuclear Partons: the Fermi Statistics or Nuclear Opacity?,"We derive the two-plateau momentum distribution of final state (FS) quarks
+produced in deep inelastic scattering (DIS) off nuclei in the saturation
+regime. The diffractive plateau which dominates for small transverse momentum p
+measures precisely the momentum distribution of quarks in the beam photon, the
+role of the nucleus is simply to provide an opacity. The plateau for truly
+inelastic DIS exhibits a substantial nuclear broadening of the FS momentum
+distribution. We discuss the relationship between the FS quark densities and
+the properly defined initial state (IS) nuclear quark densities.The
+Weizs\""acker-Williams glue of a nucleus exhibits a substantial nuclear
+dilution, still soft IS nuclear sea saturates because of the anti-collinear
+splitting of gluons into sea quarks.",0207210v2
+2002-07-28,No Froissart Bound from Gluon Saturation,"In the previous work hep-ph/0112140, hep-ph/0204277, we showed that while the
+nonlinear QCD evolution equation of Balitsky and Kovchegov (BK) leads to
+saturation of the scattering amplitude locally in impact parameter space, it
+does not unitarize the total cross section. This result was recently challenged
+by Ferreiro, Iancu, Itakura and McLerran (FIIM) who claim that the
+dipole-hadron cross section computed from the BK equation saturates the
+Froissart bound. In this comment, we point to a fundamental error in the
+argument of FIIM which invalidates their conclusion. We show that if the total
+cross section violates unitarity for a coloured scattering probe, it does so
+also for a colourless scattering probe.",0207335v2
+2002-09-25,High Density QCD and Saturation of Nuclear Partons,"We review the recent finding of the two-plateau momentum distribution of sea
+quarks in deep inelastic scattering off nuclei in the saturation regime. The
+diffractive plateau which dominates for small $\bp$ measures precisely the
+momentum distribution of quarks in the beam photon, the r\^ole of the nucleus
+is simply to provide an opacity. The plateau for truly inelastic DIS exhibits a
+substantial nuclear broadening of the momentum distribution. Despite this
+nuclear broadening, the observed final state and initial state sea quark
+densities do coincide exactly. We emphasize how the saturated sea is generated
+from the nuclear-diluted Weizs\""acker-Williams because of the anti-collinear
+splitting of gluons into sea quarks.",0209298v1
+2002-10-24,Parton saturation and N_part scaling of semi--hard processes in QCD,"We argue that the suppression of high p_t hadrons discovered recently in
+heavy ion collisions at RHIC may be a consequence of saturation in the Color
+Glass Condensate. We qualitatively and semi-quantitatively describe the data,
+in particular, the dependence upon the number of nucleon participants. We show
+that if parton saturation sets in at sufficiently small energy, then in
+nucleus-nucleus collisions at RHIC and LHC energies the cross sections of
+semi-hard processes should scale approximately with the number of participants,
+N_{part}. Our results provide a possible explanation of both the absence of
+apparent jet quenching at SPS energies and its presence at RHIC. Under the same
+assumption we predict that in semi--central and central pA (dA) collisions at
+collider energies the dependence of semi--hard processes on the number of
+participating nucleons of the nucleus will change to \sim (N_{part}^A)^{1/2}.
+The forthcoming data on dA collisions will provide a crucial test of this
+description.",0210332v2
+2002-12-12,"High Density QCD, Saturation and Diffractive DIS","We review a consistent description of the fusion and saturation of partons in
+the Lorentz-contracted ultrarelativistic nuclei in terms of a nuclear
+attenuation of color dipole states of the photon and collective
+Weizs\""acker-Williams (WW) gluon structure function of a nucleus. Diffractive
+DIS provides a basis for the definition of the WW nuclear glue. The point that
+all observables for DIS off nuclei are uniquely calculable in terms of the
+nuclear WW glue amounts to a new form of factorization in the saturation
+regime.",0212176v1
+2002-12-18,Polarized Hyperons from pA Scattering in the Gluon Saturation Regime,"We study the production of transversely polarized Lambda hyperons in
+high-energy collisions of protons with large nuclei. The large gluon density of
+the target at saturation provides an intrinsic semi-hard scale which should
+naturally allow for a weak-coupling QCD description of the process in terms of
+a convolution of the quark distribution of the proton with the elementary
+quark-nucleus scattering cross section (resummed to all twists) and a
+fragmentation function. In this case of transversely polarized Lambda
+production we employ a so-called polarizing fragmentation function, which is an
+odd function of the transverse momentum of the Lambda relative to the
+fragmenting quark. Due to this k_t-odd nature, the resulting Lambda
+polarization is essentially proportional to the derivative of the quark-nucleus
+cross section with respect to transverse momentum, which peaks near the
+saturation momentum scale. Such processes might therefore provide generic
+signatures for high parton density effects and for the approach to the
+``black-body'' (unitarity) limit of hadronic scattering.",0212260v2
+2002-12-19,The Dipole Picture and Saturation in Soft Processes,"We attempt to describe soft hadron interactions in the framework of
+saturation models, one based upon the Balitsky-Kovchegov non-linear equation
+and another one due to Golec-Biernat and W\""{u}sthoff. For $pp$, $Kp$, and $\pi
+p$ scattering the relevant hadronic wave functions are formulated, and total,
+elastic cross-sections, and the forward elastic slope are calculated and
+compared to experimental data. The saturation mechanism leads to reasonable
+reproduction of the data for the quantities analyzed, except for the forward
+elastic slope, where the predicted increase with energy is too moderate.",0212284v2
+2003-01-15,Nuclear A-dependence near the Saturation Boundary,"The A-dependence of the saturation momentum and the scaling behavior of the
+scattering of a small dipole on a nuclear target are studied in the
+McLerran-Venugopalan model, in fixed coupling BFKL dynamics and in running
+coupling BFKL dynamics. In each case, we find scaling not too far from the
+saturation boundary, although for fixed coupling evolution the scaling function
+for large A is not the same as for an elementary dipole. We find that $Q_s^2$
+is proportional to $A^{1/3}$ in the McLerran-Venugopalan model and in fixed
+coupling evolution, however, we find an almost total lack of A-dependence in
+$Q_s^2$ in the case of running coupling evolution.",0301109v1
+2003-04-16,QCD Saturation and Photoproduction on Proton and Nuclei Targets,"We calculate inclusive photoproduction cross-sections for both proton and
+nuclei targets, using a saturation model derived from an approximate solution
+to the Balitsky-Kovchegov nonlinear evolution equation. This paper extends our
+hypothesis, that one can successfully use the dipole picture and saturation
+models to describe soft processes, instead of the soft Pomeron Regge
+parametrization. Our fit is compatible with our previous fit to DIS data, and
+utilizes the same phenomenological parameters as in our paper devoted to soft
+hadronic interactions. Using the Glauber formalism, and no additional
+parameters, we calculate the cross-sections for photoproduction on various
+nuclei, and compare our results with the relevant data.",0304166v2
+2003-04-30,How far is normal nuclear matter from the chiral symmetry restoration?,"Properties of cold nuclear matter are studied within a generalized
+Nambu-Jona-Lasinio model formulated on the level of constituent nucleons. The
+model parameters are chosen to reproduce simultaneously the observed nucleon
+and pion masses in vacuum as well as saturation properties of nuclear matter.
+The strongest constraints on these parameters are given by the empirical values
+of the nucleon effective mass and compression modulus at nuclear saturation
+density. A preferable value of the cut-off momentum, determining density of
+active quasinucleon states in the Dirac sea, is estimated to about 400 MeV/c.
+With the most reasonable choice of model parameters we have found a first order
+phase transition of the liquid-gas type at subsaturation densities and the
+gradual restoration of chiral symmetry at about 3 times the saturation density.
+Fluctuations of the scalar condensate around its mean-field value are estimated
+and shown to be large in the vicinity of chiral transition.",0304296v1
+2003-05-23,Saturation and parton level Cronin effect: enhancement vs suppression of gluon production in p-A and A-A collisions,"We note that the phenomenon of perturbative saturation leads to transverse
+momentum broadening in the spectrum of partons produced in hadronic collisions.
+This broadening has a simple interpretation as parton level Cronin effect for
+systems in which saturation is generated by the ""tree level"" Glauber-Mueller
+mechanism. For systems where the broadening results form the nonlinear QCD
+evolution to high energy, the presence or absence of Cronin effect depends
+crucially on the quantitative behavior of the gluon distribution functions at
+transverse momenta kt outside the so called scaling window. We discuss the
+relation of this phenomenon to the recent analysis by Kharzeev-Levin-McLerran
+of the momentum and centrality dependence of particle production in
+nucleus-nucleus collisions at RHIC.",0305265v2
+2003-06-27,On solutions of the Balitsky-Kovchegov equation with impact parameter,"We numerically analyze the Balitsky-Kovchegov equation with the full
+dependence on impact parameter b. We show that due to a particular b-dependence
+of the initial condition the amplitude decreases for large dipole sizes r. Thus
+the region of saturation has a finite extension in the dipole size r, and its
+width increases with rapidity. We also calculate the b-dependent saturation
+scale and discuss limitations on geometric scaling. We demonstrate the instant
+emergence of the power-like tail in impact parameter, which is due to the long
+range contributions. Thus the resulting cross section violates the Froissart
+bound despite the presence of a nonlinear term responsible for saturation.",0306279v2
+2003-07-07,Geometric Scaling in Inclusive Charm Production,"We show that the cross section for inclusive charm production exhibits
+geometric scaling in a large range of photon virtualities. In the HERA
+kinematic domain the saturation momentum $Q_{sat}^2(x)$ stays below the hard
+scale $\mu_c^2=4m_c^2$, implying charm production probing mostly the color
+transparency regime and unitarization effects being almost negligible. We
+derive our results considering two saturation models which are able to describe
+the DESY ep collider HERA data for the proton structure function at small
+values of the Bjorken variable $x$. A striking feature is the scaling on
+$\tau=Q_2^2/Q_{sat}^2(x)$ above saturation limit, corroborating recent
+theoretical studies.",0307090v2
+2003-10-31,Traveling wave fronts and the transition to saturation,"We propose a general method to study the solutions to nonlinear QCD evolution
+equations, based on a deep analogy with the physics of traveling waves. In
+particular, we show that the transition to the saturation regime of high energy
+QCD is identical to the formation of the front of a traveling wave. Within this
+physical picture, we provide the expressions for the saturation scale and the
+gluon density profile as a function of the total rapidity and the transverse
+momentum. The application to the Balitsky-Kovchegov equation for both fixed and
+running coupling constants confirms the effectiveness of this method.",0310357v2
+2003-12-12,Impact of saturation on s-channel helicity nonconservation for diffractive vector mesons,"As Glauber has shown in 1959, the spin-flip phenomena caused by the
+conventional spin-orbit interaction do vanish in the scattering off heavy,
+strongly absorbing nuclei. On the other hand, the origin of the s-channel
+helicity nonconservation (SCHNC) in diffractive DIS is of the origin different
+from simple spin-orbit interaction, and here we demonstrate that SCHNC in
+vector meson production survives strong absorption effects in nuclear targets.
+The intranuclear absorption often discussed in terms of the saturation effects
+introduces a new large scale $Q_A^2$ into the calculation of diffractive vector
+meson production amplitudes. Based on the color dipole approach, we show how
+the impact of the saturation scale $Q_A^2$ changes from the coherent to
+incoherent/quasifree diffractive vector mesons.",0312170v1
+2004-08-06,Dilepton low $p_T$ suppression as an evidence of the Color Glass Condensate,"The dilepton production is investigated in proton-nucleus collisions in the
+forward region using the Color Glass Condensate approach. The transverse
+momentum distribution ($p_T$), more precisely the low $p_T$ region, where the
+saturation effects are expected to increase, is analyzed. The ratio between
+proton-nucleus and proton-proton differential cross section for RHIC and LHC
+energies is evaluated, showing the effects of saturation at small $p_T$, and
+presenting a Cronin type peak at moderate $p_T$. These features indicate the
+dilepton as a most suitable probe to study the properties of the saturated
+regime and the Cronin effect.",0408097v2
+2004-09-22,Saturation: Colour Glass Condensate and colour sources,"In the recent years we have seen a lot of activity around systems and
+experiments, like DIS at HERA or the heavy-ion experiments at RHIC, involving a
+large number of partons due to the high enery and/or the high number of
+participants of those experiments. The main problem in this regime is that of
+the high parton densities. In fact, in most of the models of multiparticle
+production, two contributions to the multiplicity are considered: one
+proportional to the number of participant nucleons, $N_{part}$, and a second
+one proportional to the number of collisions, $N_{part}^{4/3}$. In order to get
+the right multiplicities at RHIC it is necessary to lower the second
+contribution. A possible mechanism for this is the saturation. Here, I am going
+to review the saturation of parton densities in the initial state, in two
+different frameworks: the Colour Glass Condensate %(CGC) and the string
+clustering.",0409264v1
+2004-11-15,Saturation momentum at fixed and running QCD coupling,"A relationship, linking the saturation momentum in the case of fixed and
+running QCD coupling, respectively, is derived from the Balitsky-Kovchegov
+equation. It relies on the linear instability of the evolution equation in the
+dilute regime. The leading orders of the saturation momenta are mapped onto
+each other exactly. For subleading terms a qualitative correspondence is
+achieved with a relative error going to zero for large rapidities. The
+relationship can also be derived for the Balitsky-Kovchegov equation with a
+cutoff accounting for low-density effects and is satisfied by the corresponding
+isoline functions. Further implications arise for the existence of
+travelling-wave solutions in the two situations.",0411192v2
+2005-06-13,Particle Correlations in Saturated QCD Matter,"We study quantitatively angular correlations in the two-particle spectrum
+produced by an energetic probe scattering off a dense hadronic target with
+sizeable saturation momentum. To this end, two parton inclusive cross sections
+for arbitrary projectiles with small color charge density are derived in the
+eikonal formalism. Our results are the following: For large momenta of the
+observed particles, the perturbative limit with characteristic back-to-back
+correlation is recovered. As the trigger momenta get closer to the saturation
+scale Q_s, the angular distribution broadens. When the momenta are
+significantly smaller than Q_s, the azimuthal distribution is broad but still
+peaked back-to-back. However, in a narrow momentum range (0.5 - 1.5) Q_s, we
+observe that the azimuthal correlation splits into a double peak with maxima
+displaced away from 180 degree. We argue that it is the soft multiple
+scattering physics that is responsible for the appearance of this shift in the
+angle of maximal correlation. We also point out that when the physical size of
+the projectile is particularly small, the double peak structure persists in a
+significantly wider range of final state momenta.",0506126v1
+2005-10-07,"Color strings, Pomerons and Color Glass Condensate","In the recent experiments like DIS at HERA or the heavy-ion experiments at
+RHIC, and also in expected LHC at CERN, the number of involved partons is very
+large, due to the high energy and/or the high number of participants of those
+experiments. These high parton densities should in principal lead to an
+extremely huge multiparticle production, but experimentally we have seen that
+this is not the case. So there should be a mechanism that reduces the number of
+created particle. Here, I review the problem of parton saturation and its
+implications through three in principal different approaches, but somewhat
+related: saturation in a geometrical approach, QCD saturation through the Color
+Glass Condensate and perturbative Pomeron approach with initial conditions.",0510102v1
+2005-11-18,Saturation in diffractive deep inelastic eA scattering,"In this paper we investigate the saturation physics in diffractive deep
+inelastic electron-ion scattering. We estimate the energy and nuclear
+dependence of the ratio $\sigma^{diff}/\sigma^{tot}$ and predict the $x_{\pom}$
+and $\beta$ behavior of the nuclear diffractive structure function
+$F_{2,A}^{D(3)}(Q^2, \beta, x_{IP})$. Moreover, we analyze the ratio
+$R^{diff}_{A1,A2}(Q^2, \beta, x_{IP}) = F_{2,A1} ^{D(3)}/F_{2,A2} ^{D(3)}$,
+which probes the nuclear dependence of the structure of the Pomeron. We show
+that saturation physics predicts that approximately 37 % of the events observed
+at eRHIC should be diffractive.",0511224v2
+2006-05-17,Saturation in High-energy QCD,"In these proceedings, I shall review the basic concepts of perturbative QCD
+in its high-energy limit, emphasising the approach to the unitarity limit,
+usually referred to as {\em saturation}. I shall explain the basic framework
+showing the need for saturation, first, from a simple picture of the
+high-energy behaviour, then, giving a short derivation of the equation driving
+this evolution. In the second part, I shall exhibit an analogy with statistical
+physics and show how this allows to derive {\em geometric scaling} in QCD with
+saturation. I shall finally consider the effects of gluon-number fluctuations
+on this picture.",0605192v1
+2006-06-21,On the probability distribution of the stochastic saturation scale in QCD,"It was recently noticed that high-energy scattering processes in QCD have a
+stochastic nature. An event-by-event scattering amplitude is characterised by a
+saturation scale which is a random variable. The statistical ensemble of
+saturation scales formed with all the events is distributed according to a
+probability law whose cumulants have been recently computed. In this work, we
+obtain the probability distribution from the cumulants. We prove that it can be
+considered as Gaussian over a large domain that we specify and our results are
+confirmed by numerical simulations.",0606233v2
+2006-07-11,Saturation Physics in Ultra High Energy Cosmic Rays: Heavy Quark Production,"In this work we estimate the heavy quark production in the interaction of
+ultra high energy cosmic rays in the atmosphere, considering that the primary
+cosmic ray is a proton or a photon. At these energies the saturation momentum
+Q_{sat}^2 stays above the hard scale \mu_c^2=4m_c^2, implying charm production
+probing the saturation regime. In particular, we show that the ep HERA data
+presents a scaling on \tau_c = (Q^2+\mu_c^2)/Q_{sat}^2. We derive our results
+considering the dipole picture and the Color Glass Condensate formalism, which
+one shows to be able to describe the heavy quark production in photon-proton
+and proton-proton collisions. Nuclear effects are considered in computation of
+cross sections for scattering on air nuclei. Implications on the flux of prompt
+leptons at the earth are analyzed and a large suppression is predicted.",0607125v2
+2006-10-31,QCD at high energy: saturation and fluctuation effects,"In these proceedings, I shall review the basic concepts of perturbative QCD
+in its high-energy limit. I shall concentrate on the approach to the unitarity
+limit, usually referred to as saturation, as well as on the gluon-number
+fluctuations the importance of which has recently been discovered. I shall
+explain the basic framework showing the need for those phenomena, first, from a
+simple picture of the high-energy behaviour, then, giving a short derivation of
+the equation driving this evolution. In the second part, I shall exhibit an
+analogy with statistical physics and show how this allows to derive geometric
+scaling in QCD with saturation. I shall finally consider the effects of
+gluon-number fluctuations on this picture and draw the physical consequences,
+i.e. a new scaling law, arising from those results.",0610436v1
+2007-01-31,Liouville field theory for gluon saturation in QCD at high energy,"We argue that quantum Liouville field theory supplemented with a suitable
+source term is the effective theory which describes the short-range
+correlations of the gluon saturation momentum in the two-dimensional
+impact-parameter space, at sufficiently high energy and for a large number of
+colors. This is motivated by recent developments concerning the stochastic
+aspects of the high-energy evolution in QCD, together with the manifest scale
+invariance of the respective evolution equations and general considerations on
+the uncertainty principle. The source term explicitly breaks down the conformal
+symmetry of the (pure) Liouville action, thus introducing a physical mass scale
+in the problem which is identified with the average saturation momentum. We
+construct this source term for the case of a homogeneous distribution and show
+that this leads to an interesting theory: the relevant correlation functions
+are ultraviolet finite (and not just renormalizable) when computed in
+perturbation theory, due to mutual cancellations of the tadpole divergences.
+Possible generalizations to inhomogeneous source terms are briefly discussed.",0701276v1
+2007-02-08,Geometric Scaling and QCD Dynamics in DIS,"DIS data from HERA show a striking regularity as \sigma^{\gamma^* p} is a
+function of the ratio \tau=Q^2/Q_s^2(x) only. The scaling function shows a
+break at \tau ~ 1, which has been taken as an indication for saturation.
+However, besides saturation also the transition between dominance of
+k_t-ordered (DGLAP) and k_t-non-ordered (BFKL) evolution contributes to a break
+around this value of \tau, as well as the suppression for small Q^2 due to
+finite quark masses and confinement. In this paper we use a dipole cascade
+model based on Mueller's dipole model, which also includes energy conservation
+and pomeron mergins, to investigate the contributions of these different
+effects to the scaling behaviour. As a result we predict that the scaling
+function for \tau < 1 will be modified when data for Q^2 > 1 GeV^2 become
+available. We also investigate the scaling properties of the charm contribution
+and the impact parameter dependence of the saturation scale.",0702087v3
+2007-02-13,Universality of QCD traveling-waves with running coupling,"The Balitsky-Kovchegov QCD equation for rapidity evolution describing
+saturation effects at high energy admits universal asymptotic traveling-wave
+solutions when the nonlinear damping becomes effective. The asymptotic
+solutions fall in universality classes depending only on some specific
+properties of the solution of the associated linear equation. We derive these
+solutions for the recent QCD formulations of the Balitsky-Kovchegov equation
+with running coupling constant obtained from quark-loop calculation. While the
+associated linear solutions depend in different ways with observables and
+higher-order effects, we show that the asymptotic traveling-wave solutions all
+belong to the same universality class whose solutions are given. Hence the
+influence of saturation stabilizes the QCD evolution with respect to higher
+order effects and leads to universal features at high enough rapidity, such as
+the form of the traveling waves, the intercept of the saturation scale and
+geometric scaling in square-root of the rapidity.",0702131v2
+2007-02-16,Exclusive vector meson production at HERA from QCD with saturation,"Following recent predictions that the geometric scaling properties of deep
+inelastic scattering data in inclusive gamma*-p collisions are expected also in
+exclusive diffractive processes, we investigate the diffractive production of
+vector mesons. Using analytic results in the framework of the BK equation at
+non-zero momentum transfer, we extend to the non-forward amplitude a
+QCD-inspired forward saturation model including charm, following the
+theoretical predictions for the momentum transfer dependence of the saturation
+scale. We obtain a good fit to the available HERA data and make predictions for
+deeply virtual Compton scattering measurements.",0702171v2
+1995-12-22,Massless BPS-Saturated States on the Two-Torus Moduli Sub-Space of Heterotic String,"Within a four-dimensional, toroidally compactified heterotic string, we
+identify (quantized) charge vectors of electrically charged BPS-saturated
+states (along with the tower of SL(2,Z) related dyonic states), which preserve
+1/2 of N=4 supersymmetry and become massless along the hyper-surfaces of
+enhanced gauge symmetry of the two-torus moduli sub-space. In addition, we
+identify charge vectors of the dyonic BPS-saturated states (along with the
+tower of SL(2,Z) related states), which preserve 1/4 of N=4 supersymmetry, and
+become massless at two points with the maximal gauge symmetry enhancement.",9512188v3
+1997-02-28,BPS-Saturated Bound States of Tilted P-Branes in Type II String Theory,"We found BPS-saturated solutions of M-theory and Type II string theory which
+correspond to (non-marginally) bound states of p-branes intersecting at angles
+different from pi/2. These solutions are obtained by starting with a BPS
+marginally bound (orthogonally) intersecting configurations of two p-branes
+(e.g, two four-branes of Type II string theory), performing a boost
+transformation at an angle with respect to the world-volume of the
+configuration, performing T-duality transformation along the boost-direction,
+S-duality transformation, and T- transformations along the direction
+perpendicular to the boost transformation. The resulting configuration is
+non-marginally bound BPS-saturated solution whose static metric possesses the
+off-diagonal term which cannot be removed by a coordinate transformation, and
+thus signifies an angle (different from pi/2) between the resulting
+intersecting p-branes. Additional new p-branes are bound to this configuration,
+in order to ensure the stability of such a static, tilted configuration.",9702205v3
+1997-06-19,BPS-Saturated Walls in Supersymmetric Theories,"Domain-wall solutions in four-dimensional supersymmetric field theories with
+distinct discrete vacuum states lead to the spontaneous breaking of
+supersymmetry, either completely or partially. We consider in detail the case
+when the domain walls are the BPS-saturated states, and 1/2 of supersymmetry is
+preserved. Several useful criteria that relate the preservation of 1/2 of
+supersymmetry on the domain walls to the central extension appearing in the N=1
+superalgebras are established. We explain how the central extension can appear
+in N=1 supersymmetry and explicitly obtain the central charge in various
+models: the generalized Wess-Zumino models, and supersymmetric Yang-Mills
+theories with or without matter. The BPS-saturated domain walls satisfy the
+first-order differential equations which we call the creek equations, since
+they formally coincide with the (complexified) equations of motion of an analog
+high-viscosity fluid on a profile which is given by the superpotential of the
+original problem. Some possible applications are considered.",9706141v3
+1997-07-30,Four-dimensional BPS-spectra via M-theory,"We consider the realization of four-dimensional theories with N = 2
+supersymmetry as M-theory configurations including a five-brane. Our emphasis
+is on the spectrum of massive states, that are realized as two-branes ending on
+the five-brane. We start with a determination of the supersymmetries that are
+left unbroken by the background metric and five-brane. We then show how the
+central charge of the N = 2 algebra arises from the central charge associated
+with the M-theory two-brane. This determines the condition for a two-brane
+configuration to be BPS-saturated in the four-dimensional sense. By imposing
+certain conditions on the moduli, we can give concrete examples of such
+two-branes. This leads us to conjecture that vectormultiplet and hypermultiplet
+BPS-saturated states correspond to two-branes with the topology of a cylinder
+and a disc respectively. We also discuss the phenomenon of marginal stability
+of BPS-saturated states.",9707251v2
+2000-06-11,BPS Saturated Domain Walls along a Compact Dimension,"Generalized Wess-Zumino models which admit topologically non-trivial BPS
+saturated configurations along one compact, spatial dimension are investigated
+in various dimensions of space-time. We show that, in a representative model
+and for sufficiently large circumference, there are BPS configurations along
+the compact dimension containing an arbitrary number of equidistant,
+well-separated domain walls. We analyze the spectrum of the bosonic and
+fermionic light and massless modes that are localized on these walls. The
+masses of the light modes are exponentially suppressed by the ratio of the
+distance between the walls and their width. States that are initially localized
+on one wall oscillate in time between all the walls. In (2+1) dimensions the
+``chirality'' of localized, massless fermions is determined. In the
+(1+1)-dimensional case we show how the mass of certain classically BPS
+saturated solitons is lifted above the BPS bound by instanton tunneling.",0006077v3
+2003-07-29,Nonvanishing quantum corrections to the mass and central charge of the N=2 vortex and BPS saturation,"The one-loop quantum corrections to the mass and central charge of the N=2
+vortex in 2+1 dimensions are determined using supersymmetry-preserving
+dimensional regularization by dimensional reduction of the corresponding N=1
+model with Fayet-Iliopoulos term in 3+1 dimensions. Both the mass and the
+central charge turn out to have nonvanishing one-loop corrections which however
+are equal and thus saturate the Bogomolnyi bound. We explain BPS saturation by
+standard multiplet shortening arguments, correcting a previous claim in the
+literature postulating the presence of a second degenerate short multiplet at
+the quantum level.",0307282v3
+1996-09-15,"Characterizing aleph_epsilon-saturated models of superstable ndop theories by L_{infty, aleph_epsilon}-theory","After the main gap theorem was proved (see [Sh:c]), in discussion, Harrington
+expressed a desire for a finer structure - of finitary character (when we have
+a structure theorem at all). I point out that the logic L_{infty,aleph_0}(d.q.)
+(d.q. stands for dimension quantifier) does not suffice: e.g., for T=Th(lambda
+x 2^\omega,E_n)_{n<omega} where (alpha,eta)E_n(beta,nu) =: eta|n=nu|n and for a
+subset S of 2^omega we define
+  M_S = M | {(alpha,eta): [eta in S -> alpha<omega_1] and [eta in 2^\omega
+backslash S -> alpha<omega]}.
+  Hence, it seems to me we should try L_{infty,aleph_epsilon}(d.q.)
+(essentially, in C we can quantify over sets which are included in the
+algebraic closure of finite sets), and Harrington accepts this interpretation.
+Here the conjecture is proved for aleph_epsilon-saturated models. I.e., the
+main theorem is M equiv_{L_{infty,aleph_epsilon}(d.q.)} N iff M cong N for
+aleph_epsilon--saturated models of a superstable countable (first order) theory
+T without dop.",9609215v1
+2001-01-04,Simple Homogeneous Models,"Geometrical stability theory is a powerful set of model-theoretic tools that
+can lead to structural results on models of a simple first-order theory.
+Typical results offer a characterization of the groups definable in a model of
+the theory. The work is carried out in a universal domain of the theory (a
+saturated model) in which the Stone space topology on ultrafilters of definable
+relations is compact. Here we operate in the more general setting of
+homogeneous models, which typically have noncompact Stone topologies. In this
+paper strongly lambda-homogeneous models (M,R) in which the elements of R
+induce a symmetric and transitive notion of independence with bounded character
+are studied. This notion of independence, defined using a combinatorial
+condition called ``dividing'', agrees with forking independence when (M,R) is
+saturated. The concept central to the development of geometrical stability
+theory for saturated structures, namely the canonical base, is also shown to
+exist in this setting.",0101036v2
+2001-10-23,On the existence of completely saturated packings and completely reduced covering,"A packing by a body $K$ is collection of congruent copies of $K$ (in either
+Euclidean or hyperbolic space) so that no two copies intersect nontrivially in
+their interiors. A covering by $K$ is a collection of congruent copies of $K$
+such that for every point $p$ in the space there is copy in the collection
+containing $p$. A completely saturated packing is one in which it is not
+possible to replace a finite number of bodies of the packing with a larger
+number and still remain a packing. A completely reduced covering is one in
+which it is not possible to replace a finite number of bodies of the covering
+with a smaller number and still remain a covering. It was conjectured by G.
+Fejes Toth, G. Kuperberg, and W. Kuperberg that completely saturated packings
+and commpletely reduced coverings exist for every body $K$ in either
+$n$-dimensional Euclidean or $n$-dimensional hyperbolic space. We prove this
+conjecture.",0110260v1
+2003-11-11,A definable nonstandard model of the reals,"We prove in ZFC the existence of a definable, countably saturated elementary
+extension of the reals.
+  It seems that it has been taken for granted that there is no distinguished,
+definable nonstandard model of the reals. (This means a countably saturated
+elementary extension of the reals.) Of course if V=L then there is such an
+extension (just take the first one in the sense of the canonical well-ordering
+of L), but we mean the existence provably in ZFC. There were good reasons for
+this: without Choice we cannot prove the existence of any elementary extension
+of the reals containing an infinitely large integer. Still there is one.
+  Theorem (ZFC). There exists a definable, countably saturated extension R* of
+the reals R, elementary in the sense of the language containing a symbol for
+every finitary relation on R.",0311165v1
+2005-03-14,Moduli of objects in dg-categories,"To any dg-category $T$ (over some base ring $k$), we define a $D^{-}$-stack
+$\mathcal{M}_{T}$ in the sense of \cite{hagII}, classifying certain
+$T^{op}$-dg-modules. When $T$ is saturated, $\mathcal{M}_{T}$ classifies
+compact objects in the triangulated category $[T]$ associated to $T$. The main
+result of this work states that under certain finiteness conditions on $T$
+(e.g. if it is saturated) the $D^{-}$-stack $\mathcal{M}_{T}$ is locally
+geometric (i.e. union of open and geometric sub-stacks). As a consequence we
+prove the algebraicity of the group of auto-equivalences of a saturated
+dg-category. We also obtain the existence of reasonable moduli for perfect
+complexes on a smooth and proper scheme, as well as complexes of
+representations of a finite quiver.",0503269v5
+2006-07-24,Computing holes in semi-groups and its applications to transportation problems,"An integer feasibility problem is a fundamental problem in many areas, such
+as operations research, number theory, and statistics. To study a family of
+systems with no nonnegative integer solution, we focus on a commutative
+semigroup generated by a finite set of vectors in $\Z^d$ and its saturation. In
+this paper we present an algorithm to compute an explicit description for the
+set of holes which is the difference of a semi-group $Q$ generated by the
+vectors and its saturation. We apply our procedure to compute an infinite
+family of holes for the semi-group of the $3\times 4\times 6$ transportation
+problem. Furthermore, we give an upper bound for the entries of the holes when
+the set of holes is finite. Finally, we present an algorithm to find all
+$Q$-minimal saturation points of $Q$.",0607599v3
+2000-09-04,Stable autosolitons in dispersive media with saturable gain and absorption,"We introduce the simplest one-dimensional model of a dispersive optical
+medium with saturable dissipative nonlinearity and filtering (dispersive loss)
+which gives rise to stable solitary pulses (autosolitons). In the particular
+case when the dispersive loss is absent, the same model may also be interpreted
+as describing a stationary field in a planar optical waveguide with uniformly
+distributed saturable gain and absorption. In a certain region of the model's
+parameter space, two coexisting solitary-pulse solutions are found numerically,
+one of which may be stable. Solving the corresponding linearized eigenvalue
+problem, we identify stability borders for the solitary pulses in their
+parametric plane. Beyond one of the borders, the symmetric pulse is destroyed
+by asymmetric perturbations, and at the other border it undergoes a Hopf
+bifurcation, which may turn it into a breather.",0009011v1
+2004-02-17,Saturation of Turbulent Drag Reduction in Dilute Polymer Solutions,"Drag reduction by polymers in turbulent wall-bounded flows exhibits universal
+and non-universal aspects. The universal maximal mean velocity profile was
+explained in a recent theory. The saturation of this profile and the crossover
+back to the Newtonian plug are non-universal, depending on Reynolds number Re,
+concentration of polymer $c_p$ and the degree of polymerization $N_p$. We
+explain the mechanism of saturation stemming from the finiteness of
+extensibility of the polymers, predict its dependence on $c_p$ and $N$ in the
+limit of small $c_p$ and large Re, and present the excellent comparison of our
+predictions to experiments on drag reduction by DNA.",0402027v1
+2004-11-19,Saturation of azimuthal anisotropy in Au + Au collisions at sqrt(s_NN) = 62 - 200 GeV,"New measurements are presented for charged hadron azimuthal correlations at
+mid-rapidity in Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV. They are
+compared to earlier measurements obtained at sqrt(s_NN) = 130 GeV and in Pb+Pb
+collisions at sqrt(s_NN) = 17.2 GeV. Sizeable anisotropies are observed with
+centrality and transverse momentum (p_T) dependence characteristic of elliptic
+flow (v_2). For a broad range of centralities, the observed magnitudes and
+trends of the differential anisotropy, v_2(p_T), change very little over the
+collision energy range sqrt(s_NN) = 62-200 GeV, indicating saturation of the
+excitation function for v_2 at these energies. Such a saturation may be
+indicative of the dominance of a very soft equation of state for sqrt(s_NN) =
+62-200 GeV.",0411040v1
+1992-12-09,Relativistic Nuclear Matter with Self-Consistent Correlation Energy,"We study relativistic nuclear matter in the $\sigma - \omega$ model including
+the ring-sum correlation energy. The model parameters are adjusted
+self-consistently to give the canonical saturation density and binding energy
+per nucleon with the ring energy included. Two models are considered,
+mean-field-theory where we neglect vacuum effects, and the relativistic Hartree
+approximation where such effects are included but in an approximate way. In
+both cases we find self-consistent solutions and present equations of state. In
+the mean-field case the ring energy completely dominates the attractive part of
+the energy density and the elegant saturation mechanism of the standard
+approach is lost, namely relativistic quenching of the scalar attraction. In
+the relativistic Hartree approach the vacuum effects are included in an
+approximate manner using vertex form factors with a cutoff of 1 - 2 GeV, the
+range expected from QCD. Due to the cutoff, the ring energy for this case is
+significantlysmaller, and we obtain self-consistent solutions which preserve
+the basic saturation mechanism of the standard relativistic approach.",9212003v1
+1993-01-20,Relativistic Ring-Diagram Nuclear Matter Calculations,"A relativistic extension of the particle-particle hole-hole ring-diagram
+many-body formalism is developed by using the Dirac equation for
+single-particle motion in the medium. Applying this new formalism, calculations
+are performed for nuclear matter. The results show that the saturation density
+is improved and the equation of state becomes softer as compared to
+corresponding Dirac-Brueckner-Hartree-Fock calculations. Using the Bonn A
+potential, nuclear matter is predicted to saturate at an energy per nucleon of
+--15.30 MeV and a density equivalent to a Fermi momentum of 1.38 fm$^{-1}$, in
+excellent agreement with empirical information. The compression modulus is 152
+MeV at the saturation point.",9301012v1
+1995-06-30,Saturation properties and incompressibility of nuclear matter: A consistent determination from nuclear masses,"Starting with a two-body effective nucleon-nucleon interaction, it is shown
+that the infinite nuclear matter model of atomic nuclei is more appropriate
+than the conventional Bethe-Weizsacker like mass formulae to extract saturation
+properties of nuclear matter from nuclear masses. In particular, the saturation
+density thus obtained agrees with that of electron scattering data and the
+Hartree-Fock calculations. For the first time using nuclear mass formula, the
+radius constant $r_0$=1.138 fm and binding energy per nucleon $a_v$ = -16.11
+MeV, corresponding to the infinite nuclear matter, are consistently obtained
+from the same source. An important offshoot of this study is the determination
+of nuclear matter incompressibility $K_{\infty}$ to be 288$\pm$ 28 MeV using
+the same source of nuclear masses as input.",9506032v1
+1995-11-07,New QCD Sum Rules for Nucleons in Nuclear Matter,"Two new QCD sum rules for nucleons in nuclear matter are obtained from a
+mixed correlator of spin-1/2 and spin-3/2 interpolating fields. These new sum
+rules, which are insensitive to the poorly known four-quark condensates,
+provide additional information on the nucleon scalar self-energy. These new sum
+rules are analyzed along with previous spin-1/2 interpolator-based sum rules
+which are also insensitive to the poorly known four-quark condensates. The
+analysis indicates consistency with the expectations of relativistic nuclear
+phenomenology at nuclear matter saturation density. However, a weaker density
+dependence near saturation is suggested. Using previous estimates of in-medium
+condensate uncertainties, we find $M^* = 0.64^{+0.13}_{-0.09}$ GeV and
+$\Sigma_v = 0.29^{+0.06}_{-0.10}$ GeV at nuclear matter saturation density.",9511007v3
+1998-08-26,Saturation Properties of Nuclear Matter with a Nonlocal Confining Solitons,"We examine saturation properties of a quark-based picture of nuclear matter.
+Soliton matter consisting of nonlocal confining solitons is used to model
+nuclear matter. Each composite nucleon is described by a non-topological
+soliton as given by the Global Color Model. We apply techniques and concepts
+from the discription of crystal lattices. In particular, the Wigner-Seitz
+approximation is used to calculate the properties of the soliton lattice at the
+mean-field level. We focus on infinite nuclear matter at around standard
+nuclear matter density with the simplest one-parameter assumption for the gluon
+propagator. the saturation density and incompressibility are calculated as
+functions of the single parameter of the model",9808067v1
+2000-07-13,Saturation of low-energy antiproton annihilation on nuclei,"Recent measurements of very low-energy ($p_{L}<100$ MeV/c) $\bar p$
+annihilation on light nuclei reveal apparent suppression of annihilation upon
+increasing the atomic charge $Z$ and mass number $A$. Using $\bar p$-nucleus
+optical potentials $V_{{\rm opt}}$, fitted to $\bar p$-atom energy-shifts and
+-widths, we resolve this suppression as due to the strong effective repulsion
+produced by the very absorptive $V_{{\rm opt}}$. The low-energy $\bar
+p$-nucleus wavefunction is kept substantially outside the nuclear surface and
+the resulting reaction cross section saturates as function of the strength of
+Im $V_{{\rm opt}}$. This feature, for $E >0$, parallels the recent prediction,
+for $E < 0$, that the level widths of $\bar p$ atoms saturate and, hence, that
+$\bar p$ deeply bound atomic states are relatively narrow. Antiproton
+annihilation cross sections are calculated at $p_{L}=57$ MeV/c across the
+periodic table, and their dependence on $Z$ and $A$ is classified and discussed
+with respect to the Coulomb focussing effect at very low energies.",0007029v2
+2000-08-08,Energy and Centrality Dependence of Rapidity Densities at RHIC,"The energy and centrality dependence of the charged multiplicity per
+participant nucleon is shown to be able to differentiate between final-state
+saturation and fixed scale pQCD models of initial entropy production in
+high-energy heavy-ion collisions. The energy dependence is shown to test the
+nuclear enhancement of the mini-jet component of the initial conditions, while
+the centrality dependence provides a key test of whether gluon saturation is
+reached at RHIC energies. HIJING model predicts that the rapidity density per
+participant increases with centrality, while the saturation model prediction is
+essentially independent of centrality.",0008014v2
+2001-05-22,Chiral Dynamics and Nuclear Matter,"We calculate the equation of state of isospin-symmetric nuclear matter in the
+three-loop approximation of chiral perturbation theory. The contributions to
+the energy per particle $\bar E(k_f)$ from one- and two-pion exchange diagrams
+are ordered in powers of the Fermi momentum $k_f$ (modulo functions of $k_f
+/m_\pi$). It is demonstrated that, already at order ${\cal O}(k_f^4)$, two-pion
+exchange produces realistic nuclear binding. The underlying saturation
+mechanism is surprisingly simple (in the chiral limit), namely the combination
+of an attractive $k_f^3$-term and a repulsive $k_f^4$-term. The empirical
+saturation point and the nuclear compressibility $K\simeq 250 $MeV are well
+reproduced at order ${\cal O}(k_f^5)$ with a momentum cut-off of $\Lambda
+\simeq 0.65$ GeV which parametrizes short-range dynamics. No further
+short-distance terms are required in our calculation of nuclear matter. In the
+same framework we calculate the density-dependent asymmetry energy and find
+$A_0\simeq 34 $MeV at the saturation point, in good agreement with the
+empirical value. The pure neutron matter equation of state is also in fair
+qualitative agreement with sophisticated many-body calculations and a
+resummation result of effective field theory, but only for low neutron
+densities $\rho_n <0.25 $fm$^{-3}$.",0105057v1
+2001-08-13,Relevance of high-momentum nucleons for nuclear phenomena,"A brief review is given concerning the status of the theoretical work on
+nucleon spectral functions. A recent concern about the validity of the concept
+of spectroscopic factors as deduced from (e,e'p) reactions at higher Q^2, is
+discussed in some detail. The consequences of the observed spectral strength
+are then considered in the context of nuclear saturation. It is argued that
+short-range correlations are mainly responsible for the actual value of the
+observed charge density in 208Pb and by extension for the empirical value of
+the saturation density of nuclear matter. This observation combined with the
+general understanding of the spectroscopic strength suggests that a renewed
+study of nuclear matter, emphasizing the self-consistent determination of the
+spectral strength due to short-range and tensor correlations, may shed light on
+the perennial nuclear saturation problem. First results using such a scheme are
+presented.",0108028v1
+2001-08-13,Saturation properties of nuclear matter and correlated nucleons,"A brief overview is given of the properties of spectral functions in finite
+nuclei as obtained from (e,e'p) experiments. Based on recent experimental data
+from this reaction it is argued that the empirical value of the saturation
+density of nuclear matter is dominated by short-range correlations. This
+observation and the observed fragmentation and depletion of the single-particle
+strength in nuclei provide the motivation for attempting a self-consistent
+description of the nucleon spectral functions with full inclusion of
+short-range and tensor correlations in nuclear matter. Results for these
+``second generation'' spectral functions will be discussed with emphasis on the
+consequences for the saturation properties of nuclear matter. Arguments are
+presented to clarify the obscuring role of pionic long-range correlations in
+this long-standing problem.",0108029v1
+2004-08-19,Phase Separation of Saturated and Mono-unsaturated Lipids as determined from a Microscopic Model,"A molecular model is proposed of a bilayer consisting of fully saturated DPPC
+and mono unsaturated DOPC. The model not only encompasses the constant density
+within the hydrophobic core of the bilayer, but also the tendency of chain
+segments to align. It is solved within self-consistent field theory. A model
+bilayer of DPPC undergoes a main chain transition to a gel phase, while a
+bilayer of DOPC does not do so above zero degrees centigrade because of the
+double bond which disrupts order. We examine structural and thermodynamic
+properties of these membranes and find our results in reasonable accord with
+experiment. In particular, order-parameter profiles are in good agreement with
+NMR experiments. A phase diagram is obtained for mixtures of these lipids in a
+membrane at zero tension. The system undergoes phase separation below the
+main-chain transition temperature of the saturated lipid. Extensions to the
+ternary DPPC, DOPC, and cholesterol system are outlined.",0408085v2
+2005-01-14,Stable one-dimensional periodic waves in Kerr-type saturable and quadratic nonlinear media,"We review the latest progress and properties of the families of bright and
+dark one-dimensional periodic waves propagating in saturable Kerr-type and
+quadratic nonlinear media. We show how saturation of the nonlinear response
+results in appearance of stability (instability) bands in focusing (defocusing)
+medium, which is in sharp contrast with the properties of periodic waves in
+Kerr media. One of the key results discovered is the stabilization of
+multicolor periodic waves in quadratic media. In particular, dark-type waves
+are shown to be metastable, while bright-type waves are completely stable in a
+broad range of energy flows and material parameters. This yields the first
+known example of completely stable periodic wave patterns propagating in
+conservative uniform media supporting bright solitons. Such results open the
+way to the experimental observation of the corresponding self-sustained
+periodic wave patterns.",0501075v1
+2006-05-31,Acoustic wave propagation in a macroscopically inhomogeneous porous medium saturated by a fluid,"The equations of motion in a macroscopically inhomogeneous porous medium
+saturated by a fluid are derived. As a first verification of the validity of
+these equations, a two-layer rigid frame porous system considered as one single
+porous layer with a sudden change in physical properties is studied. A simple
+wave equation is derived and solved for this system. The reflection and
+transmission coefficients are calculated numerically using a wave
+splitting-Green's function approach (WS-GF). The reflected and transmitted wave
+time histories are also simulated. Experimental results obtained for materials
+saturated by air are compared to the results given by this approach and to
+those of the classical transfer matrix method (TMM).",0605259v3
+2007-04-10,A Rational Approach to Resonance Saturation in large-Nc QCD,"We point out that resonance saturation in QCD can be understood in the
+large-Nc limit from the mathematical theory of Pade Approximants to meromorphic
+functions. These approximants are rational functions which encompass any
+saturation with a finite number of resonances as a particular example,
+explaining several results which have appeared in the literature. We review the
+main properties of Pade Approximants with the help of a toy model for the
+<VV-AA> two-point correlator, paying particular attention to the relationship
+among the Chiral Expansion, the Operator Product Expansion and the resonance
+spectrum. In passing, we also comment on an old proposal made by Migdal in 1977
+which has recently attracted much attention in the context of AdS/QCD models.
+Finally, we apply the simplest Pade Approximant to the <VV-AA> correlator in
+the real case of QCD. The general conclusion is that a rational approximant may
+reliably describe a Green's function in the Euclidean, but the same is not true
+in the Minkowski regime due to the appearance of unphysical poles and/or
+residues.",0704.1247v1
+2007-09-20,Calculation of DOS-Dependent Channel Potentials in FETs in the Saturation Condition,"We calculated functions for the potential, Vch, in the channel of a field
+effect transistor with various densities of the localized states (DOS) by using
+a device simulator. In the saturation condition, Vch is found to fit
+satisfactorily to the analytical function, Vch(y)=Vg(1-(1-y/L) k), where Vg is
+the gate bias, y is the position along the channel, and L is the channel
+length. The power k, which depends on the DOS, ranges from 0 to 0.5 even with
+an extensive variation of DOS. As a result, the total induced charge density in
+the saturation condition can be expressed a way similar to the linear condition
+by introducing a correction factor, alpha, ranging between 0.65 and 1.0.",0709.3298v1
+2007-10-11,Deep inelastic scattering at strong coupling from gauge/string duality : the saturation line,"For gauge theories which admit a dual string description, we analyze deep
+inelastic scattering at strong 't Hooft coupling and high energy, in the
+vicinity of the unitarity limit. We discuss the onset of unitarity corrections
+and determine the saturation line which separates weak scattering from strong
+scattering in the parameter space of rapidity and photon virtuality. We
+discover that the approach towards unitarity proceeds through two different
+mechanisms, depending upon the photon virtuality Q^2 : single Pomeron exchange
+at relatively low Q^2 and, respectively, multiple graviton exchanges at higher
+Q^2. This implies that the total cross-section at high energy and large Q^2 is
+dominated by diffractive processes. This is furthermore suggestive of a
+partonic description where all the partons have transverse momenta below the
+saturation momentum and occupation numbers of order one.",0710.2148v2
+2007-10-27,On The Linear Behaviour of the Throughput of IEEE 802.11 DCF in Non-Saturated Conditions,"We propose a linear model of the throughput of the IEEE 802.11 Distributed
+Coordination Function (DCF) protocol at the data link layer in non-saturated
+traffic conditions. We show that the throughput is a linear function of the
+packet arrival rate (PAR) $\lambda$ with a slope depending on both the number
+of contending stations and the average payload length. We also derive the
+interval of validity of the proposed model by showing the presence of a
+critical $\lambda$, above which the station begins operating in saturated
+traffic conditions.
+  The analysis is based on the multi-dimensional Markovian state transition
+model proposed by Liaw \textit{et al.} with the aim of describing the behaviour
+of the MAC layer in unsaturated traffic conditions. Simulation results closely
+match the theoretical derivations, confirming the effectiveness of the proposed
+linear model.",0710.5238v1
+2007-11-22,The Dynamical Dipole Radiation in Dissipative Collisions with Exotic Beams,"Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium
+nuclear interaction in regions away from saturation. In this work we present a
+selection of reaction observables in dissipative collisions particularly
+sensitive to the isovector part of the interaction, i.e. to the symmetry term
+of the nuclear Equation of State (EoS). At low energies the behavior of the
+symmetry energy around saturation influences dissipation and fragment
+production mechanisms. We will first discuss the recently observed Dynamical
+Dipole Radiation, due to a collective neutron-proton oscillation during the
+charge equilibration in fusion and deep-inelastic collisions. We will review in
+detail all the main properties, yield, spectrum, damping and angular
+distributions, revealing important isospin effects. Reactions induced by
+unstable 132Sn beams appear to be very promising tools to test the
+sub-saturation Isovector EoS. Predictions are also presented for deep-inelastic
+and fragmentation collisions induced by neutron rich projectiles. The
+importance of studying violent collisions with radioactive beams at low and
+Fermi energies is finally stressed.",0711.3535v1
+2008-02-06,Modelling and Analysis of the Distributed Coordination Function of IEEE 802.11 with Multirate Capability,"The aim of this paper is twofold. On one hand, it presents a
+multi-dimensional Markovian state transition model characterizing the behavior
+at the Medium Access Control (MAC) layer by including transmission states that
+account for packet transmission failures due to errors caused by propagation
+through the channel, along with a state characterizing the system when there
+are no packets to be transmitted in the queue of a station (to model
+non-saturated traffic conditions). On the other hand, it provides a throughput
+analysis of the IEEE 802.11 protocol at the data link layer in both saturated
+and non-saturated traffic conditions taking into account the impact of both
+transmission channel and multirate transmission in Rayleigh fading environment.
+Simulation results closely match the theoretical derivations confirming the
+effectiveness of the proposed model.",0802.0766v1
+2008-03-04,On the High Energy Behaviour of The Total Cross Section in the QCD Dipole Model,"In this paper we perform a numerical study of the tranverse expansion of
+hadronic scattering amplitudes in the dipole picture of high energy QCD. We go
+beyond the mean field approximation by including fluctuations and also wave
+function saturation effects, and the evolution with both a fixed and a running
+coupling is investigated. We also study the nonperturbative aspects, and as has
+been predicted earlier, our results indicate that the Froissart-Martin bound is
+saturated once confinement effects are included in the evolution. Thus the
+total cross section increases proportional to the square of the logarithm of
+the cms energy. Furthermore it is seen that we obtain a reasonable value for
+the proportionality coefficient. The impact of saturation and non-leading
+effects on this coefficient is also studied.",0803.0446v3
+2008-04-02,Direct numerical simulations of the kappa-mechanism II. The nonlinear saturation and Hertzsprung's progression,"Context: We study the kappa-mechanism that excites radial oscillations in
+Cepheid variables.
+  Aims: We address the mode couplings that manages the nonlinear saturation of
+the instability in direct numerical simulations (DNS).
+  Methods: We project the DNS fields onto an acoustic subspace built from the
+regular and adjoint eigenvectors that are solutions to the linear-oscillations
+equations.
+  Results: We determine the time evolution of both the amplitude and kinetic
+energy of each mode that propagates in the DNS. More than 98% of the total
+kinetic energy is contained in two modes that correspond to the
+linearly-unstable fundamental mode and the linearly-stable second overtone.
+Because the eigenperiods ratio is close to 1/2, we discover that the nonlinear
+saturation is due to a 2:1 resonance between these two modes. An interesting
+application of this result concerns the reproduction of Hertzsprung's
+progression observed in Bump Cepheids.",0804.0345v2
+2008-06-09,Intensity-Dependent Enhancement of Saturable Absorption in PbS-Au4 Nanohybrid Composites: Evidence for Resonant Energy Transfer by Auger Recombination,"Intensity-dependent enhancement of saturable absorption in a film of PbS-Au4
+nanohybrid composites has been observed by femtosecond time-resolved transient
+absorption measurement at 780 nm. The nonlinear absorption coefficient of
+saturable absorption in PbS-Au4 nanohybrid composites is found to be dependent
+on excitation irradiance and it is determined to be -2.9 cm/GW at 78 GW/cm2, an
+enhancement of nearly fourfold in comparison with that of pure PbS quantum dots
+(QDs). The enhancement is attributed to excitation of surface plasmon by
+resonant energy transfer between PbS QDs and Au nanoparticles through Auger
+recombination.",0806.1374v1
+2008-08-15,Wilson lines - color charge densities correlators and the production of eta' in the CGC for pp and pA collisions,"We compute the inclusive differential cross section production of the
+pseudo-scalar meson eta' in high-energy proton-proton (pp) and proton-nucleus
+(pA) collisions. We use an effective coupling between gluons and eta' meson to
+derive a reduction formula that relates the eta' production to a field-strength
+tensor correlator. For pA collisions we take into account saturation effects on
+the nucleus side by using the Color Glass Condensate formalism to evaluate this
+correlator. We derive new results for Wilson line - color charges correlators
+in the McLerran-Venugopalan model needed in the computation of eta' production.
+The unintegrated parton distribution functions are used to characterize the
+gluon distribution inside protons. We show that in pp collisions, the cross
+section depends on the parametrization of unintegrated parton distribution
+functions and thus, it can be used to put constraints on these distributions.
+We also demonstrate that in pA collisions, the cross section is sensitive to
+saturation effects so it can be utilized to estimate the value of the
+saturation scale.",0808.2154v1
+2008-08-21,Gluon saturation effects on J/Psi production in heavy ion collisions,"We consider a novel mechanism for J/Psi production in nuclear collisions
+arising due to the high density of gluons. We calculate the resulting J/Psi
+production cross section as a function of rapidity and centrality. We evaluate
+the nuclear modification factor and show that the rapidity distribution of the
+produced J/Psi's is significantly more narrow in AA collisions due to the gluon
+saturation effects. Our results indicate that gluon saturation in the colliding
+nuclei is a significant source of J/Psi suppression that can be disentangled
+from the quark-gluon plasma effects.",0808.2954v2
+2008-08-22,Saturated subfields and invariants of finite groups,"Every subfield $\kk(\phi)$ of the field of rational functions
+$\kk(x_1,...,x_n)$ is contained in a unique maximal subfield of the form
+$\kk(\psi)$. The element $\psi$ is called generative for the element $\phi$. A
+subfield of $\kk(x_1,...,x_n)$ is called saturated if it contains a generative
+element of each its element. We study the saturation property for subfields of
+invariants $\kk(x_1,...,x_n)^G$, where $G$ is a finite group of automorphisms
+of the field $\kk(x_1,...,x_n)$.",0808.3132v3
+2008-08-28,Stress dependent thermal pressurization of a fluid-saturated rock,"Temperature increase in saturated porous materials under undrained conditions
+leads to thermal pressurization of the pore fluid due to the discrepancy
+between the thermal expansion coefficients of the pore fluid and of the solid
+matrix. This increase in the pore fluid pressure induces a reduction of the
+effective mean stress and can lead to shear failure or hydraulic fracturing.
+The equations governing the phenomenon of thermal pressurization are presented
+and this phenomenon is studied experimentally for a saturated granular rock in
+an undrained heating test under constant isotropic stress. Careful analysis of
+the effect of mechanical and thermal deformation of the drainage and pressure
+measurement system is performed and a correction of the measured pore pressure
+is introduced. The test results are modelled using a non-linear
+thermo-poro-elastic constitutive model of the granular rock with emphasis on
+the stress-dependent character of the rock compressibility. The effects of
+stress and temperature on thermal pressurization observed in the tests are
+correctly reproduced by the model.",0808.3886v2
+2008-09-04,Superposition for Fixed Domains,"Superposition is an established decision procedure for a variety of
+first-order logic theories represented by sets of clauses. A satisfiable
+theory, saturated by superposition, implicitly defines a minimal term-generated
+model for the theory. Proving universal properties with respect to a saturated
+theory directly leads to a modification of the minimal model's term-generated
+domain, as new Skolem functions are introduced. For many applications, this is
+not desired.
+  Therefore, we propose the first superposition calculus that can explicitly
+represent existentially quantified variables and can thus compute with respect
+to a given domain. This calculus is sound and refutationally complete in the
+limit for a first-order fixed domain semantics. For saturated Horn theories and
+classes of positive formulas, we can even employ the calculus to prove
+properties of the minimal model itself, going beyond the scope of known
+superposition-based approaches.",0809.0922v3
+2008-09-06,Lifetime of the A(v'=0) state and Franck-Condon factor of the A-X(0-0) transition of CaF measured by the saturation of laser-induced fluorescence,"We describe a method for determining the radiative decay properties of a
+molecule by studying the saturation of laser-induced fluorescence and the
+associated power broadening of spectral lines. The fluorescence saturates
+because the molecules decay to states that are not resonant with the laser. The
+amplitudes and widths of two hyperfine components of a spectral line are
+measured over a range of laser intensities and the results compared to a model
+of the laser-molecule interaction. Using this method we measure the lifetime of
+the A(v'=0) state of CaF to be tau=19.2 \pm 0.7 ns, and the Franck-Condon
+factor for the transition to the X(v=0) state to be Z=0.987 (+0.013 || -0.019).
+In addition, our analysis provides a measure of the hyperfine interval in the
+lowest-lying state of A(v'=0), Delta_e=4.8 \pm 1.1 MHz.",0809.1150v2
+2008-10-17,Reduced Kronecker coefficients and counter-examples to Mulmuley's strong saturation conjecture SH,"We provide counter-examples to Mulmuley's strong saturation conjecture
+(strong SH) for the Kronecker coefficients. This conjecture was proposed in the
+setting of Geometric Complexity Theory to show that deciding whether or not a
+Kronecker coefficient is zero can be done in polynomial time. We also provide a
+short proof of the #P-hardness of computing the Kronecker coefficients. Both
+results rely on the connections between the Kronecker coefficients and another
+family of structural constants in the representation theory of the symmetric
+groups: Murnaghan's reduced Kronecker coefficients.
+  An appendix by Mulmuley introduces a relaxed form of the saturation
+hypothesis SH, still strong enough for the aims of Geometric Complexity Theory.",0810.3163v3
+2008-10-17,Fluidization of granular media wetted by liquid $^4$He,"We explore experimentally the fluidization of vertically agitated PMMA
+spheres wetted by liquid $^4$He. By controlling the temperature around the
+$\lambda$ point we change the properties of the wetting liquid from a normal
+fluid (helium I) to a superfluid (helium II). For wetting by helium I, the
+critical acceleration for fluidization ($\Gamma_c$) shows a steep increase
+close to the saturation of the vapor pressure in the sample cell. For helium II
+wetting, $\Gamma_c$ starts to increase at about 75% saturation, indicating that
+capillary bridges are enhanced by the superflow of unsaturated helium film.
+Above saturation, $\Gamma_c$ enters a plateau regime where the capillary force
+between particles is independent of the bridge volume. The plateau value is
+found to vary with temperature and shows a peak at 2.1 K, which we attribute to
+the influence of the specific heat of liquid helium.",0810.3191v3
+2008-12-08,Coherent and incoherent diffractive hadron production in pA collisions and gluon saturation,"We study coherent and incoherent diffractive hadron production in high energy
+quarkonium--heavy nucleus collisions as a probe of the gluon saturation regime
+of QCD. Taking this process as a model for pA collisions, we argue that the
+coherent diffractive gluon production, in which the target nucleus states
+intact, exhibits a remarkable sensitivity to the energy, rapidity and atomic
+number dependence. The incoherent diffractive gluon production is less
+sensitive to the details of the low-x dynamics but can serve as a probe of
+fluctuations in the color glass condensate. As a quantitative measure of the
+nuclear effects on diffractive hadron production we introduce a new observable
+-- the diffractive nuclear modification factor. We discuss possible signatures
+of gluon saturation in diffractive gluon production at RHIC, LHC and EIC.",0812.1519v2
+2008-12-24,Incompressibility of neutron-rich matter,"The saturation properties of neutron-rich matter are investigated in a
+relativistic mean-field formalism using two accurately calibrated models: NL3
+and FSUGold. The saturation properties - density, binding energy per nucleon,
+and incompressibility coefficient - are calculated as a function of the
+neutron-proton asymmetry alpha=(N-Z)/A to all orders in alpha. Good agreement
+(at the 10% level or better) is found between these numerical calculations and
+analytic expansions that are given in terms of a handful of bulk parameters
+determined at saturation density. Using insights developed from the analytic
+approach and a general expression for the incompressibility coefficient of
+infinite neutron-rich matter, i.e., K0(alpha)=K0+Ktau*alpha^{2}+..., we
+construct a Hybrid model with values for K0 and Ktau as suggested by recent
+experimental findings. Whereas the Hybrid model provides a better description
+of the measured distribution of isoscalar monopole strength in the Sn-isotopes
+relative to both NL3 and FSUGold, it significantly underestimates the
+distribution of strength in 208Pb. Thus, we conclude that the incompressibility
+coefficient of neutron-rich matter remains an important open problem.",0812.4499v2
+2009-02-04,On the Saturation of the Magnetorotational Instability via Parasitic Modes,"We investigate the stability of incompressible, exact, non-ideal
+magnetorotational (MRI) modes against parasitic instabilities. Both
+Kelvin-Helmholtz and tearing-mode parasitic instabilities may occur in the
+dissipative regimes accessible to current numerical simulations. We suppose
+that a primary MRI mode saturates at an amplitude such that its fastest
+parasite has a growth rate comparable to its own. The predicted alpha parameter
+then depends critically on whether the fastest primary and parasitic modes fit
+within the computational domain and whether non-axisymmetric parasitic modes
+are allowed. Hence even simulations that resolve viscous and resistive scales
+may not saturate properly unless the numerical domain is large enough to allow
+the free evolution of both MRI and parasitic modes. To minimally satisfy these
+requirements in simulations with vertical background fields, the vertical
+extent of the domain should accommodate the fastest growing MRI mode while the
+radial and azimuthal extents must be twice as large. The fastest parasites have
+horizontal wavelengths roughly twice as long as the vertical wavelength of the
+primary.",0902.0794v2
+2009-02-12,Modified Holographic Dark Energy,"In this work, motivated by the energy bound suggested by Cohen {\it et al.},
+we propose the modified holographic dark energy (MHDE) model. Choosing the IR
+cut-off $L=R_{\rm CC}$ and considering the parameterizations $n^2=2-\lambda a$,
+$n^2=2-3\lambda a^2/(1+3a^2)$ and $n^2=2-\lambda a^2/(\beta+a^2)$, we derive
+all the physical quantities of the non-saturated MHDE model analytically. We
+find that the non-saturated MHDE models with the parameterizations
+$n^2=2-\lambda a$ and $n^2=2-3\lambda a^2/(1+3a^2)$ are single-parameter models
+in practice. Also, we consider the cosmological constraints on the
+non-saturated MHDE, and find that it is well consistent with the observational
+data.",0902.2030v4
+2009-02-23,Efficiency of Energy Conversion in Thermoelectric Nanojunctions,"Using first-principles approaches, this study investigated the efficiency of
+energy conversion in nanojunctions, described by the thermoelectric figure of
+merit $ZT$. We obtained the qualitative and quantitative descriptions for the
+dependence of $ZT$ on temperatures and lengths. A characteristic temperature:
+$T_{0}= \sqrt{\beta/\gamma(l)}$ was observed. When $T\ll T_{0}$, $ZT\propto
+T^{2}$. When $T\gg T_{0}$, $ZT$ tends to a saturation value. The dependence of
+$ZT$ on the wire length for the metallic atomic chains is opposite to that for
+the insulating molecules: for aluminum atomic (conducting) wires, the
+saturation value of $ZT$ increases as the length increases; while for
+alkanethiol (insulating) chains, the saturation value of $ZT$ decreases as the
+length increases. $ZT$ can also be enhanced by choosing low-elasticity bridging
+materials or creating poor thermal contacts in nanojunctions. The results of
+this study may be of interest to research attempting to increase the efficiency
+of energy conversion in nano thermoelectric devices.",0902.3876v3
+2009-03-02,A dynamic nonlinear model for saturation in industrial growth,"A general nonlinear logistic equation has been proposed to model long-time
+saturation in industrial growth. An integral solution of this equation has been
+derived for any arbitrary degree of nonlinearity. A time scale for the onset of
+nonlinear saturation in industrial growth can be estimated from an
+equipartition condition between nonlinearity and purely exponential growth.
+Precise predictions can be made about the limiting values of the annual revenue
+and the human resource content that an industrial organisation may attain.
+These variables have also been modelled to set up an autonomous first-order
+dynamical system, whose equilibrium condition forms a stable node (an attractor
+state) in a related phase portrait. The theoretical model has received close
+support from all relevant data pertaining to the well-known global company,
+IBM.",0903.0282v1
+2009-04-22,Comprehensive study of the vapour-liquid equilibria of the pure two-centre Lennard-Jones plus pointdipole fluid,"Results of a systematic investigation of the vapour-liquid equilibria of 38
+individual two-centre Lennard-Jones plus axial pointdipole model fluids (2CLJD)
+are reported over a range of reduced dipolar momentum 0 $\le \mu^{*2} \le$ 20
+and of reduced elongation 0 $\le$ L* $\le$ 1.0. Temperatures investigated are
+from about 55 % to about 95 % of the critical temperature of each fluid. The
+NpT+Test Particle Method is used for the generation of vapour pressures,
+saturated densities, and saturated enthalpies. For the lowest temperatures,
+these data are calculated with highly accurate chemical potentials obtained
+from the gradual insertion method. Critical temperatures $T*_c$ and densities
+$\rho*_c$ are obtained from Guggenheim's equations. Empirical correlations for
+critical data $T*_c$ and $\rho*_c$ as well as for saturated densities $\rho'*$,
+$\rho''*$, and vapour pressures $p*_\sigma$ are developed as global functions
+of the model parameters. They describe the simulation data generally within
+their statistical uncertainties. Critical pressures and acentric factors of the
+2CLJD fluid can be calculated from these correlations. The present results are
+a sound basis for adjustments of the model parameters $\mu^{*2}$, $L*$,
+$\sigma$, and $\epsilon$ to experimental VLE data of real fluids.",0904.3413v1
+2009-04-23,Comprehensive study of the vapour-liquid equilibria of the pure two-centre Lennard-Jones plus pointquadrupole fluid,"Results of a systematic investigation of the vapour-liquid equilibria (VLE)
+of 30 individual two-centre Lennard-Jones plus pointquadrupole model fluids
+(2CLJQ) are reported over a range of reduced quadrupolar momentum $0 \le Q^{*2}
+\le 4$ and of reduced elongation $0 \le L^* \le 0.8$. Temperatures investigated
+are from about 55 % to about 95 % of the critical temperature of each fluid.
+Uniformly the $NpT$+Test Particle Method based on molecular dynamics
+simulations is used for the generation of vapour pressures, saturated
+densities, and saturated enthalpies. Critical temperatures $T^*_{\rm c}$ and
+densities $\rho^*_{\rm c}$ are obtained from Guggenheim's equations. Empirical
+correlations for critical data $T^*_{\rm c}$ and $\rho^*_{\rm c}$ as well as
+for saturated densities $\rho'^*$, $\rho''^*$, and vapour pressures
+$p^*_{\sigma}$ are developed as global functions of the model parameters. In
+most cases they describe the simulation data within their statistical
+uncertainties. Critical pressures and acentric factors of the 2CLJQ fluid can
+be calculated from present correlations. The present simulations are a sound
+basis for adjustments of the model parameters $Q^{*2}$, $L^*$, $\sigma$, and
+$\epsilon$ to experimental VLE data of real fluids.",0904.3679v1
+2009-06-26,Existence of a measurable saturated compensation function between subshifts and its applications,"We show the existence of a bounded Borel measurable saturated compensation
+function for a factor map between subshifts. As an application, we find the
+Hausdorff dimension and measures of full Hausdorff dimension for a compact
+invariant set of an expanding nonconformal map on the torus given by an
+integer-valued diagonal matrix. These problems were studied in [19] for a
+compact invariant set whose symbolic representation is a shift of finite type
+under the condition of the existence of a saturated compensation function. We
+extend the results by presenting a formula for the Hausdorff dimension for a
+compact invariant set whose symbolic representation is a subshift without the
+condition and characterizing the invariant ergodic measures of full dimension
+as the ergodic equilibrium states of a constant multiple of a measurable
+compensation function. For a compact invariant set whose symbolic
+representation is a topologically mixing shift of finite type, we study
+uniqueness and the properties for the unique invariant ergodic measure of full
+dimension by using a measurable compensation function. Our positive results
+narrow the possibility of where an example having more than one measure of full
+dimension can be found.",0906.4989v1
+2009-07-14,e+A physics at a future Electron-Ion Collider,"A future Electron-Ion Colllider (EIC) is the ideal laboratory for studying
+the gluon distributions in both nucleons and nuclei for $\sqrt{s}$ = 63 - 158
+(40 - 110) GeV/A for e+p (e+A) collisions. Whilst gluon distributions have been
+studied extensively in nucleons at HERA, there is very little information on
+them for $x <$ 0.1 in nuclei. The rapid increase in the gluon momentum
+distribution at low-$x$ in nucleons found at HERA, if not tamed, leads to the
+violation of the Froissart Unitarity Bound at small-$x$. This can be achieved
+in non-linear QCD by allowing for the recombination of low-$x$ gluons until
+saturation of gluon densities occurs. Understanding saturation is an important
+goal not just for QCD in general, but also in understanding the initial
+conditions of heavy-ion collisions in particular. In this paper, I describe the
+physics that will be explored by e+A collisions, where saturation is more
+easily explored in this mode at an EIC than in e+p collisions due to the large
+nuclear densities achieved.",0907.2431v1
+2009-07-30,Isobaric incompressibility of the isospin asymmetric nuclear matter,"The isospin dependence of the saturation properties of asymmetric nuclear
+matter, particularly the incompressibility $K_\infty (X) = K_\infty + K_\tau
+X^2 + O(X^4)$ at saturation density is systematically studied using density
+dependent M3Y interaction. The $K_\tau$ characterizes the isospin dependence of
+the incompressibility at saturation density $\rho_0$. The approximate
+expression $K_{asy} \approx K_{sym}-6L$ is often used for $K_\tau$ where $L$
+and $K_{sym}$ represent, respectively, the slope and curvature parameters of
+the symmetry energy at $\rho_0$. It can be expressed accurately as
+$K_\tau=K_{sym}-6L-\frac{Q_0}{K_\infty}L$ where $Q_0$ is the third-order
+derivative parameter of symmetric nuclear matter at $\rho_0$. The results of
+this addendum to Phys. Rev. C 80, 011305(R) (2009) indicate that the $Q_0$
+contribution to $K_\tau$ is not insignificant.",0907.5350v2
+2009-09-03,Fractal flow patterns in hydrophobic microfluidic pore networks: experimental modeling of two-phase flow in porous electrodes,"Experimental two-phase invasion percolation flow patterns were observed in
+hydrophobic micro-porous networks designed to model fuel cell specific porous
+media. In order to mimic the operational conditions encountered in the porous
+electrodes of polymer electrolyte membrane fuel cells (PEMFCs), micro-porous
+networks were fabricated with corresponding microchannel size distributions.
+The inlet channels were invaded homogeneously with flow rates corresponding to
+fuel cell current densities of 1.0 to 0.1 A/cm2 (Ca 10e-7-10e-8). A variety of
+fractal breakthrough patterns were observed and analyzed to quantify flooding
+density and geometrical diversity in terms of the total saturation, St, local
+saturations, s, and fractal dimension, D. It was found that St increases
+monotonically during the invasion process until the breakthrough point is
+reached, and s profiles indicate the dynamic distribution of the liquid phase
+during the process. Fractal analysis confirmed that the experiments fall within
+the flow regime of invasion percolation with trapping. In this work, we propose
+to correlate the fractal dimension, D, to the total saturation and use this map
+as a parameter for modeling liquid water transport in the GDL.",0909.0758v1
+2009-11-11,Saturation of Stationary Inversion States in a Three-Level Traveling-Wave Quantum Amplifier with Bistable Resonator Pumping,"The inversion states of a saturated traveling-wave three-level quantum
+paramagnetic amplifier have been investigated under conditions of bistable
+resonator pumping. The equations of motion for the vectorial order parameter
+have been obtained using adiabatic elimination of fast variables. The exact
+solutions for stationary inversion states have been found from these equations.
+For high-quality pump resonators, the isolated and the semi-isolated branches
+of the inversion ratio have been revealed in stationary solutions. The
+existence of the semi-isolated branches means a possibility of collapse of the
+inversion state under influence of a saturating signal. Revival of inversion is
+possible in this case only by the hard excitation of the pump system. This
+nonlinear phenomenon is of a qualitatively another nature than one described by
+us in arXiv:0901.0449v1 [nlin.AO], and may be observed at moderate Q-factor of
+pump resonator.",0911.2124v1
+2010-01-18,The low temperature thermal expansion of single-walled carbon nanotube bundles saturated with nitrogen,"The effect of a N2 impurity on the radial thermal expansion coefficient (ar)
+of single-walled carbon nanotube bundles has been investigated in the
+temperature interval 2.2 - 43 K by the dilatometric method. Saturation of
+nanotube bundles with N2 caused a sharp increase in the positive magnitudes of
+ar in the whole range of temperatures used and a very high and wide maximum in
+the thermal expansion coefficient (ar)(T) at T about 28 K. The low temperature
+desorption of the impurity from the N2-saturated powder of bundles of
+single-walled carbon nanotubes with open and closed ends has been investigated.",1001.2992v1
+2010-01-28,Gluon saturation effects at forward rapidities at LHC in pp collisions,"We investigate hadrons and direct photon production in pp collisions at the
+LHC energy within the color-dipole approach. We show that greatest sensitivity
+to gluon saturation effects is reached at very forward rapidities in pp
+collisions at LHC (\sqrt{s}=14 TeV). The discrepancies among various saturation
+models (fitted to HERA data) results can be about a factor of 2-3 at forward
+rapidities. We found that the ratio of direct-photon to pion production can be
+about 20-10 at forward rapidities \eta=7-8. Therefore, direct photon production
+at forward rapidities should provide a rather clean probe as the background
+from radiative hadronic decays is significantly suppressed.",1001.5266v1
+2010-01-29,Reactions of C$_2$({\it a}$^3Pi_u$) with selected saturated alkanes: A temperature dependence study,"We present a temperature dependence study on the gas phase reactions of the
+C$_2$({\it a}$^3Pi_u$) radical with a selected series of saturated alkanes
+(C$_2$H$_6$, C$_3$H$_8$, n-C$_4$H$_10$, i-C$_4$H$_10$, and n-C$_6$H$_14$) by
+means of pulsed laser photolysis/laser-induced fluorescence technique. The
+bimolecular rate constants for these reactions were obtained between 298 and
+673 K. A pronounced negative temperature effect was observed for n-C$_4$H$_10$,
+i-C$_4$H$_10$, and n-C$_6$H$_14$ and interpreted in terms of steric hindrance
+of the more reactive secondary or tertiary C-H bonds by less reactive CH$_3$
+groups. Detailed analysis of our experimental results reveals quantitatively
+the temperature dependence of reactivities for the primary, secondary, and
+tertiary C-H bonds in these saturated alkanes and further lends support to a
+mechanism of hydrogen abstraction.",1001.5342v3
+2010-01-31,Saturation of the Anomalous Hall Effect in Critically Disordered Ultra-thin CNi3 Films,"We demonstrate that a distinct high-disorder anomalous Hall effect phase
+emerges at the correlated insulator threshold of ultra-thin, amorphous,
+ferromagnetic CNi3 films. In the weak localization regime, where the sheet
+conductance G >> e^2/h, the anomalous Hall resistance of the films increases
+with increasing disorder and the Hall conductance scales as Gxy ~ G^1.6.
+However, at sufficiently high disorder the system begins to enter the 2D
+correlated insulator regime, at which point the Hall resistance Rxy abruptly
+saturates and the scaling exponent becomes 2. Tunneling measurements show that
+the saturation behavior is commensurate with the emergence of the 2D Coulomb
+gap, suggesting that e-e interactions mediate the high-disorder phase.",1002.0099v1
+2010-03-23,From low-bias mobility to high-bias current saturation: fundamental trade-offs in graphene based transistors,"We describe the fundamental trade-offs in engineering the mobility, current
+saturation and ON- OFF ratios in graphene transistors. Surprisingly, the
+trade-offs arise solely from an asymptotic constraint on the high energy
+bandstructure and independent of scattering processes. This places graphite
+derivatives (bulk monolayer graphene, uniaxially strained graphene nanoribbons,
+carbon nanotubes and bilayer graphene) on the same 3-parameter
+mobility-bandgap-scattering length ({\mu} - Egap -{\lambda}) plot, proximal to
+other semiconductors. In addition to this low-bias trade-off, the high bias
+current bears signatures of the underlying saturation mechanism, arising
+through phonon scattering or {\Gamma}-point suppressed density of states
+opening bandgap.",1003.4551v3
+2010-03-28,On subgroups of saturated or totally bounded paratopological groups,"A paratopological group $G$ is saturated if the inverse $U^{-1}$ of each
+non-empty set $U\subset G$ has non-empty interior. It is shown that a
+[first-countable] paratopological group $H$ is a closed subgroup of a saturated
+(totally bounded) [abelian] paratopological group if and only if $H$ admits a
+continuous bijective homomorphism onto a (totally bounded) [abelian]
+topological group $G$ [such that for each neighborhood $U\subset H$ of the unit
+$e$ there is a closed subset $F\subset G$ with $e\in h^{-1}(F)\subset U$]. As
+an application we construct a paratopological group whose character exceeds its
+$\pi$-weight as well as the character of its group reflexion. Also we present
+several examples of (para)topological groups which are subgroups of totally
+bounded paratopological groups but fail to be subgroups of regular totally
+bounded paratopological groups.",1003.5355v1
+2010-04-07,Spatial fairness in linear wireless multi-access networks,"Multi-access networks may exhibit severe unfairness in throughput. Recent
+studies show that this unfairness is due to local differences in the
+neighborhood structure: Nodes with less neighbors receive better access. We
+study the unfairness in saturated linear networks, and adapt the multi-access
+CSMA protocol to remove the unfairness completely, by choosing the activation
+rates of nodes appropriately as a function of the number of neighbors. We then
+investigate the consequences of this choice of activation rates on the
+network-average saturated throughput, and we show that these rates perform well
+in a non-saturated setting.",1004.1042v1
+2010-05-12,Parametrization of the Relativistic ($σ-ω$) Model for Nuclear Matter,"We have investigated the zero-temperature equation of state (EoS) for
+infinite nuclear matter within the $(\sigma-\omega)$ model at all densities
+$n_{\mathrm{B}}$ and different proton-neutron asymmetry $\eta\equiv(N-Z)/A$. We
+have presented an analytical expression for the compression modulus and found
+that nuclear matter ceases to saturate at $\eta$ slightly larger than $0.8$.
+Afterward, we have developed an analytical method to determine the strong
+coupling constants from the EoS for isospin symmetric nuclear matter, which
+allow us to reproduce all the saturation properties with high accuracy. For
+various values of the nucleon effective mass and the compression modulus, we
+have found that the quartic self-coupling constant $G_4$ is negative, or
+positive and very large. Furthermore, we have demonstrated that it is possible
+(a) to investigate the EoS in terms of $n_{\mathrm{B}}$ and $\eta$; and (b) to
+reproduce all the known saturation properties without $G_4$. We have thus
+concluded that the latter is not necessary in the $(\sigma-\omega)$ model.",1005.2030v4
+2010-05-18,Numerical Simulations of Gravity-Driven Fingering in Unsaturated Porous Media Using a Non-Equilibrium Model,"This is a computational study of gravity-driven fingering instabilities in
+unsaturated porous media. The governing equations and corresponding numerical
+scheme are based on the work of Nieber et al. [Ch. 23 in Soil Water Repellency,
+eds. C. J. Ritsema and L. W. Dekker, Elsevier, 2003] in which non-monotonic
+saturation profiles are obtained by supplementing the Richards equation with a
+non-equilibrium capillary pressure-saturation relationship, as well as
+including hysteretic effects. The first part of the study takes an extensive
+look at the sensitivity of the finger solutions to certain key parameters in
+the model such as capillary shape parameter, initial saturation, and capillary
+relaxation coefficient. The second part is a comparison to published
+experimental results that demonstrates the ability of the model to capture
+realistic fingering behaviour.",1005.3297v1
+2010-07-07,"Improved current saturation and shifted switching threshold voltage in In2O3 nanowire based, fully transparent NMOS inverters via femtosecond laser annealing","Transistors based on various types of non-silicon nanowires have shown great
+potential for a variety of applications, especially for those require
+transparency and low-temperature substrates. However, critical requirements for
+circuit functionality such as saturated source-drain current, and matched
+threshold voltages of individual nanowire transistors in a way that is
+compatible with low temperature substrates, have not been achieved. Here we
+show that femtosecond laser pulses can anneal individual transistors based on
+In2O3 nanowires, improve the saturation of the source-drain current, and
+permanently shift the threshold voltage to the positive direction. We applied
+this technique and successfully shifted the switching threshold voltages of
+NMOS based inverters and improved their noise margin, in both depletion and
+enhancement modes. Our demonstration provides a method to trim the parameters
+of individual nanowire transistors, and suggests potential for large-scale
+integration of nanowire-based circuit blocks and systems.",1007.1168v1
+2010-08-03,Universal behavior of the gluon saturation scale at high energy including full NLL BFKL effects,"The universal traveling wave solution to the Balitsky-Kovchegov equation with
+running coupling (and other equations in the same universality class) is
+extended to subleading orders at large rapidity and small dipole size $r$. The
+large rapidity expansion of the logarithm of the saturation scale $Q_s(Y)$ is
+derived from that traveling wave solution. In addition to the two already known
+leading terms in $Y^{1/2}$ and $Y^{1/6}$, which are determined only by the LL
+BFKL kernel, the three following terms in $Y^0$, $Y^{-1/6}$ and $Y^{-1/3}$ are
+obtained. They are universal and sensitive to NLL BFKL effects. Initial
+condition dependence and NNLL BFKL effects would both start to appear only at
+the next order, which is in $Y^{-1/2}$. In the light of these results, the
+impact of the precise implementation of the running coupling in gluon
+saturation is discussed, \emph{i.e.} parent dipole size prescription \emph{vs.}
+Balitsky's prescription, and also the effect of the full NLL corrections, not
+yet implemented in numerical simulations.",1008.0498v1
+2010-08-04,Channel saturation and conductance quantization in single-atom gold constrictions,"Notwithstanding the discreteness of metallic constrictions, it is shown that
+the finite elasticity of stable, single-atom gold constrictions allows for a
+continuous and reversible change in conductance, thereby enabling observation
+of channel saturation and conductance quantization. The observed channel
+saturation and signature for conductance quantization is achieved by
+superposition of atomic/subatomic-scale oscillations on a
+retracting/approaching gold tip against a gold substrate of a scanning probe.
+Results also show that conductance histograms are neither suitable for
+evaluating the stability of atomic configurations through peak positions or
+peak height nor appropriate for assessing conductance quantization. A large
+number of atomic configurations with similar conductance values give rise to
+peaks in the conductance histogram. The positions of the peaks and counts at
+each peak can be varied by changing the conditions under which the histograms
+are made. Histogram counts below 1Go cannot necessarily be assumed to arise
+from single-atom constrictions.",1008.0886v1
+2010-09-13,On saturated fusion systems and Brauer indecomposability of Scott modules,"Let $p$ be a prime number, $G$ a finite group, $P$ a $p$-subgroup of $G$ and
+$k$ an algebraically closed field of characteristic $p$. We study the
+relationship between the category $\Ff_P(G)$ and the behavior of
+$p$-permutation $kG$-modules with vertex $P$ under the Brauer construction. We
+give a sufficient condition for $\Ff_P(G)$ to be a saturated fusion system. We
+prove that for Scott modules with abelian vertex, our condition is also
+necessary. In order to obtain our results, we prove a criterion for the
+categories arising from the data of $(b, G)$-Brauer pairs in the sense of
+Alperin-Brou\'e and Brou\'e-Puig to be saturated fusion systems on the
+underlying $p$-group.",1009.2391v1
+2010-09-21,Asymptotic growth of saturated powers and epsilon multiplicity,"Asymptotic properties of saturated powers of modules over a local domain R
+are studied. Under mild conditions, it is shown that the limit as k goes to
+infinity of the quotient of the saturation of the k-th power of a module E by
+the k-th power of E, when divided by k^{d+e-1}, exists. Here d is the dimension
+of R and e is the rank of E. We deduce that under these assumptions, the
+epsilon multiplicity of E, defined by Ulrich and Validashti as a limsup,
+actually exists as a limit.",1009.4111v4
+2010-11-16,Hadron production at the LHC: Any indication of new phenomena,"We confront soft Pomeron and gluon saturation models with the first LHC data
+on inclusive hadron production. We claim that while the first type of models
+are not able to describe some part of the LHC data, the Colour-Glass-Condensate
+(gluon saturation) approach gives an adequate description of the data. Here, we
+compare our published predictions with the recently available 7 TeV data. We
+firmly believe that if further experimental measurements confirm that the gluon
+saturation works, it will be a major discovery.",1011.3591v1
+2010-11-30,Temperature induced pore fluid pressurization in geomaterials,"The theoretical basis of the thermal response of the fluid-saturated porous
+materials in undrained condition is presented. It has been demonstrated that
+the thermal pressurization phenomenon is controlled by the discrepancy between
+the thermal expansion of the pore fluid and of the solid phase, the
+stress-dependency of the compressibility and the non-elastic volume changes of
+the porous material. For evaluation of the undrained thermo-poro-elastic
+properties of saturated porous materials in conventional triaxial cells, it is
+important to take into account the effect of the dead volume of the drainage
+system. A simple correction method is presented to correct the measured pore
+pressure change and also the measured volumetric strain during an undrained
+heating test. It is shown that the porosity of the tested material, its drained
+compressibility and the ratio of the volume of the drainage system to the one
+of the tested sample, are the key parameters which influence the most the error
+induced on the measurements by the drainage system. An example of the
+experimental evaluation of undrained thermoelastic parameters is presented for
+an undrained heating test performed on a fluid-saturated granular rock.",1011.6501v1
+2010-12-21,Analytical Modeling of Saturation Throughput in Power Save Mode of an IEEE 802.11 Infrastructure WLAN,"We consider a single station (STA) in the Power Save Mode (PSM) of an IEEE
+802.11 infrastructure WLAN. This STA is assumed to be carrying uplink and
+downlink traffic via the access point (AP). We assume that the transmission
+queues of the AP and the STA are saturated, i.e., the AP and the STA always
+have at least one packet to send. For this scenario, it is observed that uplink
+and downlink throughputs achieved are different. The reason behind the
+difference is the long term attempt rates of the STA and the AP due to the PSM
+protocol. In this paper we first obtain the the long term attempt rates of the
+STA and the AP and using these, we obtain the saturation throughputs of the AP
+and the STA. We provide a validation of analytical results using the NS-2
+simulator.",1012.4815v1
+2011-02-11,Gluon saturation and energy dependence of hadron multiplicity in pp and AA collisions at the LHC,"The recent results in \sqrt{s}=2.76 TeV Pb+Pb collisions at the Large Hadron
+Collider (LHC) reported by the ALICE collaboration shows that the power-law
+energy-dependence of charged hadron multiplicity in Pb+Pb collisions is
+significantly different from p+p collisions. We show that this different
+energy-dependence can be explained by inclusion of a strong angular-ordering in
+the gluon-decay cascade within the Color-Glass-Condensate (or gluon saturation)
+approach. This effect is more important in nucleus-nucleus collisions where the
+saturation scale is larger than 1 GeV. Our prescription gives a good
+description of the LHC data both in p+p and Pb+Pb collisions.",1102.2385v2
+2011-02-25,"Particle Production at High Energy and Large Transverse Momentum - ""The Hybrid Formalism"" Revisited","We revisit the ""`hybrid formalism""' for particle production used recently to
+study saturation effects in single hadron multiplicities at forward rapidities
+at RHIC and LHC. We point out that at leading twist there is an extra
+contribution to the formulae used so far, which corresponds to particle
+production via inelastic scattering of the projectile partons on the target
+fields. This contribution is expected to be small due to kinematics at very
+forward rapidities/very high transverse momenta, but should be significant at
+high momenta and very high energies. This contribution is expected to be most
+affected by saturation effects and is therefore an interesting object of study
+in the context of possible onset of saturation at high energies.",1102.5327v1
+2011-02-28,Characterizing and Quantifying Frustration in Quantum Many-Body Systems,"We present a general scheme for the study of frustration in quantum systems.
+We introduce a universal measure of frustration for arbitrary quantum systems
+and we relate it to a class of entanglement monotones via an exact inequality.
+If all the (pure) ground states of a given Hamiltonian saturate the inequality,
+then the system is said to be inequality saturating. We introduce sufficient
+conditions for a quantum spin system to be inequality saturating and confirm
+them with extensive numerical tests. These conditions provide a generalization
+to the quantum domain of the Toulouse criteria for classical frustration-free
+systems. The models satisfying these conditions can be reasonably identified as
+geometrically unfrustrated and subject to frustration of purely quantum origin.
+Our results therefore establish a unified framework for studying the
+intertwining of geometric and quantum contributions to frustration.",1103.0022v2
+2011-03-03,Number fluctuations of sparse quasiparticles in a superconductor,"We have directly measured quasiparticle number fluctuations in a thin film
+superconducting Al resonator in thermal equilibrium. The spectrum of these
+fluctuations provides a measure of both the density and the lifetime of the
+quasiparticles. We observe that the quasiparticle density decreases
+exponentially with decreasing temperature, as theoretically predicted, but
+saturates below 160 mK to 25-55 per cubic micron. We show that this saturation
+is consistent with the measured saturation in the quasiparticle lifetime, which
+also explains similar observations in qubit decoherence times.",1103.0758v2
+2011-04-06,Nonlinear effects for island coarsening and stabilization during strained film heteroepitaxy,"Nonlinear evolution of three-dimensional strained islands or quantum dots in
+heteroepitaxial thin films is studied via a continuum elasticity model and the
+development of a nonlinear dynamic equation governing the film morphological
+profile. All three regimes of island array evolution are identified and
+examined, including a film instability regime at early stage, a nonlinear
+coarsening regime at intermediate times, and the crossover to a saturated
+asymptotic state, with detailed behavior depending on film-substrate misfit
+strains but not qualitatively on finite system sizes. The phenomenon of island
+stabilization and saturation, which corresponds to the formation of steady but
+non-ordered arrays of strained quantum dots, occurs at later time for smaller
+misfit strain. It is found to be controlled by the strength of film-substrate
+wetting interaction which would constrain the valley-to-peak mass transport and
+hence the growth of island height, and also determined by the effect of elastic
+interaction between surface islands and the high-order strain energy of
+individual islands at late evolution stage. The results are compared to
+previous experimental and theoretical studies on quantum dots coarsening and
+saturation.",1104.1121v2
+2011-06-30,Violation of the geometric scaling behaviour of the amplitude for running QCD coupling in the saturation region,"In this paper we show that the intuitive guess that the geometric scaling
+behaviour should be violated in the case of the running QCD coupling, turns out
+to be correct. The scattering amplitude of the dipole with the size $r$ depends
+on new dimensional scale: $\Lambda_{QCD}$, even at large values $Y = \ln(1/x)$
+and $l\,=\, \ln\Lb \as\Lb r^2\Rb/\as\Lb 1/Q^2_s\Rb\Rb$. However, in this region
+we found a new scaling behaviour: the amplitude is a function of $\zeta =
+Y\,l$. We state that only in the vicinity of the saturation scale $Q_s$
+($\as(Q^2_s)\,\ln \Lb r^2 Q^2_s\Rb\,\leq \, 1$), the amplitude shows the
+geometric scaling behaviour. Based on these finding the geometric scaling
+behavior that has been seen experimentally, stems from either we have not
+probed the proton at HERA and the LHC deeply inside the saturation region or
+that there exists the mechanism of freezing of the QCD coupling constant at
+$r^2 \approx 1/Q^2_s$.",1106.6257v1
+2011-09-08,Back-to-Back Correlations of Di-hadrons in dAu Collisions at RHIC,"We perform a complete theoretical analysis of the azimuthal angular
+correlation of two-hadron productions in the forward $dAu$ collisions at RHIC
+in the saturation formalism, and obtain a very good agreement with the
+experimental data. It is demonstrated that the suppression and broadening of
+the away side peak provide a unique signal for the onset of the saturation
+mechanism at small-$x$ in a large nucleus. We emphasize that future experiments
+of di-hadron correlations in $pA$ collisions at both RHIC and LHC, and in $eA$
+collisions at the planned electron-ion collider, shall provide us with a
+thorough study and understanding of the strong interaction dynamics in the
+saturation regime.",1109.1817v3
+2011-09-13,Plane Cremona maps: saturation and regularity of the base ideal,"One studies plane Cremona maps by focusing on the ideal theoretic and
+homological properties of its homogeneous base ideal (""indeterminacy locus"").
+The {\em leitmotiv} driving a good deal of the work is the relation between the
+base ideal and its saturation. As a preliminary one deals with the homological
+features of arbitrary codimension 2 homogeneous ideals in a polynomial ring in
+three variables over a field which are generated by three forms of the same
+degree. The results become sharp when the saturation is not generated in low
+degrees, a condition to be given a precise meaning. An implicit goal,
+illustrated in low degrees, is a homological classification of plane Cremona
+maps according to the respective homaloidal types. An additional piece of this
+work relates the base ideal of a rational map to a few additional homogeneous
+""companion"" ideals, such as the integral closure, the $\boldsymbol\mu$-fat
+ideal and a seemingly novel ideal defined in terms of valuations.",1109.2815v4
+2011-09-15,Bounded domain problem for the modified Buckley-Leverett equation,"The focus of the present study is the modified Buckley-Leverett (MBL)
+equation describing two-phase flow in porous media. The MBL equation differs
+from the classical Buckley-Leverett (BL) equation by including a balanced
+diffusive-dispersive combination. The dispersive term is a third order mixed
+derivatives term, which models the dynamic effects in the pressure difference
+between the two phases. The classical BL equation gives a monotone water
+saturation profile for any Riemann problem; on the contrast, when the
+dispersive parameter is large enough, the MBL equation delivers non-monotone
+water saturation profile for certain Riemann problems as suggested by the
+experimental observations. In this paper, we first show that the solution of
+the finite interval [0,L] boundary value problem converges to that of the
+half-line [0,+\infty) boundary value problem for the MBL equation as L->
++\infty. This result provides a justification for the use of the finite
+interval boundary value problem in numerical studies for the half line problem.
+Furthermore, we extend the classical central schemes for the hyperbolic
+conservation laws to solve the MBL equation which is of pseudo-parabolic type.
+Numerical results confirm the existence of non-monotone water saturation
+profiles consisting of constant states separated by shocks.",1109.3481v1
+2011-09-16,Analysis of the temperature influence on Langmuir probe measurements on the basis of gyrofluid simulations,"The influence of the temperature and its fluctuations on the ion saturation
+current and the floating potential, which are typical quantities measured by
+Langmuir probes in the turbulent edge region of fusion plasmas, is analysed by
+global nonlinear gyrofluid simulations for two exemplary parameter regimes. The
+numerical simulation facilitates a direct access to densities, temperatures and
+the plasma potential at different radial positions around the separatrix. This
+allows a comparison between raw data and the calculated ion saturation current
+and floating potential within the simulation. Calculations of the
+fluctuation-induced radial particle flux and its statistical properties reveal
+significant differences to the actual values at all radial positions of the
+simulation domain, if the floating potential and the temperature averaged
+density inferred from the ion saturation current is used.",1109.3600v1
+2011-09-21,Traffic flow in a Manhattan-like urban system,"In this paper, a cellular automaton model of vehicular traffic in
+Manhattan-like urban system is proposed. In this model, the origin-destination
+trips and traffic lights have been considered. The system exhibits three
+different states, i.e., moving state, saturation state and global deadlock
+state. With a grid coarsening method, vehicle distribution in the moving state
+and the saturation state has been studied. Interesting structures (e.g.,
+windmill-like one, T-shirt-like one, Y-like one) have been revealed. A
+metastability of the system is observed in the transition from saturation state
+to global deadlock state. The effect of advanced traveller information system
+(ATIS), the traffic light period, and the traffic light switch strategy have
+also been investigated.",1109.4628v1
+2011-11-16,Necessary and sufficient condition for saturating the upper bound of quantum discord,"We revisit the upper bound of quantum discord given by the von Neumann
+entropy of the measured subsystem. Using the Koashi-Winter relation, we obtain
+a trade-off between the amount of classical correlation and quantum discord in
+the tripartite pure states. The difference between the quantum discord and its
+upper bound is interpreted as a measure on the classical correlative capacity.
+Further, we give the explicit characterization of the quantum states saturating
+the upper bound of quantum discord, through the equality condition for the
+Araki-Lieb inequality. We also demonstrate that the saturating of the upper
+bound of quantum discord precludes any further correlation between the measured
+subsystem and the environment.",1111.3837v4
+2011-11-22,Sensitivity of neutron to proton ratio toward the high density behavior of symmetry energy in heavy-ion collisions,"The symmetry energy at sub and supra-saturation densities has a great
+importance in understanding the exact nature of asymmetric nuclear matter as
+well as neutron star, but, it is poor known, especially at supra-saturation
+densities. We will demonstrate here that the neutron to proton ratios from
+different kind of fragments is able to determine the supra-saturation behavior
+of symmetry energy or not. For this purpose, a series of Sn isotopes are
+simulated at different incident energies using the Isospin Quantum Molecular
+Dynamics (IQMD) model with either a soft or a stiff symmetry energy for the
+present study. It is found that the single neutron to proton ratio from free
+nucleons as well as LCP's is sensitive towards the symmetry energy, incident
+energy as well as isospin asymmetry of the system. However, with the double
+neutron to proton ratio, it is true only for the free nucleons. It is possible
+to study the high density behavior of symmetry energy by using the neutron to
+proton ratio from free nucleons.",1111.5073v2
+2011-12-12,QCD saturation at the LHC: comparisons of models to p+p and A+A data and predictions for p+Pb collisions,"In a previous paper (arXiv:1011.1895), we showed that saturation models,
+constrained by e+p HERA data on inclusive and diffractive cross-sections, are
+in good agreement with p+p data at LHC in the soft sector. Particularly
+impressive was the agreement of saturation models with the multiplicity
+distribution as a function of $n_{\rm ch.}$. In this paper, we extend these
+studies further and consider the agreement of these models with data on bulk
+distributions in A+A collisions. We compare our results to data on central and
+forward particle production in d+Au collisions at RHIC and make predictions for
+inclusive distributions in p+Pb collisions at the LHC.",1112.2445v2
+2011-12-23,Threshold Saturation in Spatially Coupled Constraint Satisfaction Problems,"We consider chains of random constraint satisfaction models that are
+spatially coupled across a finite window along the chain direction. We
+investigate their phase diagram at zero temperature using the survey
+propagation formalism and the interpolation method. We prove that the SAT-UNSAT
+phase transition threshold of an infinite chain is identical to the one of the
+individual standard model, and is therefore not affected by spatial coupling.
+We compute the survey propagation complexity using population dynamics as well
+as large degree approximations, and determine the survey propagation threshold.
+We find that a clustering phase survives coupling. However, as one increases
+the range of the coupling window, the survey propagation threshold increases
+and saturates towards the phase transition threshold. We also briefly discuss
+other aspects of the problem. Namely, the condensation threshold is not
+affected by coupling, but the dynamic threshold displays saturation towards the
+condensation one. All these features may provide a new avenue for obtaining
+better provable algorithmic lower bounds on phase transition thresholds of the
+individual standard model.",1112.6320v2
+2012-02-13,Error Floor Approximation for LDPC Codes in the AWGN Channel,"This paper addresses the prediction of error floors of low-density
+parity-check (LDPC) codes with variable nodes of constant degree in the
+additive white Gaussian noise (AWGN) channel. Specifically, we focus on the
+performance of the sum-product algorithm (SPA) decoder formulated in the
+log-likelihood ratio (LLR) domain. We hypothesize that several published error
+floor levels are due to the manner in which decoder implementations handled the
+LLRs at high SNRs. We employ an LLR-domain SPA decoder that does not saturate
+near-certain messages and find the error rates of our decoder to be lower by at
+least several orders of magnitude. We study the behavior of trapping sets (or
+near-codewords) that are the dominant cause of the reported error floors.
+  We develop a refined linear model, based on the work of Sun and others, that
+accurately predicts error floors caused by elementary tapping sets for
+saturating decoders. Performance results of several codes at several levels of
+decoder saturation are presented.",1202.2826v2
+2012-04-03,Generic features of the phase transition in cold and dense quark matter,"We investigate the phase transition in cold and dense quark matter in an
+intuitive way that shares common features of the effective model approaches. We
+first express the quasi-particle contribution to the thermodynamic potential
+with the dynamical mass M and then discuss how we can understand the possible
+first-order phase transition with and without the vector interaction from the
+saturation curve on the plane of the energy per particle and the density. We
+next extend our analysis including inhomogeneity and discuss the relation
+between the order of the phase transition and the saturation curve. We
+emphasize that the saturation curve is useful to infer qualitative nature of
+the phase transition even without knowing the explicit solution of the ground
+state.",1204.0594v4
+2012-04-10,Saturating the unitarity bound in AdS/CFT_(AdS),"We investigate the holographic description of CFTs defined on the cylinder
+and on AdS, which include an operator saturating the unitarity bound. The
+standard Klein-Gordon field with the corresponding mass and boundary conditions
+on global AdS_(d+1) and on an AdS_(d+1) geometry with AdS_d conformal boundary
+contains ghosts. We identify a limit in which the singleton field theory is
+obtained from the bulk theory with standard renormalized inner product, showing
+that a unitary bulk theory corresponding to an operator which saturates the
+unitarity bound can be formulated and that this yields a free field on the
+boundary. The normalizability issues found for the standard Klein-Gordon field
+on the geometry with AdS_d conformal boundary are avoided for the singleton
+theory, which offers interesting prospects for multi-layered AdS/CFT.",1204.2054v1
+2012-05-21,Quantum information transfer and models for black hole mechanics,"General features of information transfer between quantum subsystems, via
+unitary evolution, are investigated, with applications to the problem of
+information transfer from a black hole to its surroundings. A particularly
+direct form of quantum information transfer is ""subspace transfer,"" which can
+be characterized by saturation of a subadditivity inequality. We also describe
+more general unitary quantum information transfer, and categorize different
+models for black hole evolution. Evolution that only creates paired excitations
+inside/outside the black hole is shown not to extract information, but
+information-transferring models exist both in the ""saturating"" and
+""non-saturating"" category. The former more closely capture thermodynamic
+behavior; the latter generically have enhanced energy flux, beyond that of
+Hawking.",1205.4732v3
+2012-05-22,Gluon saturation in dijet production in p-Pb collisions at Large Hadron Collider,"We study saturation effects in the production of dijets in p-p and p-Pb
+collisions using the framework of high energy factorization. We focus on
+central-forward jet configurations, which allow for probing gluon density at
+low longitudinal momentum fraction. We find significant suppression of the
+central-forward jet decorrelations in p-Pb compared to p-p, which we attribute
+to saturation of gluon density in nuclei.",1205.5035v3
+2012-08-28,Saturating the random graph with an independent family of small range,"Motivated by Keisler's order, a far-reaching program of understanding basic
+model-theoretic structure through the lens of regular ultrapowers, we prove
+that for a class of regular filters $D$ on $I$, $|I| = \lambda > \aleph_0$, the
+fact that $P(I)/\de$ has little freedom (as measured by the fact that any
+maximal antichain is of size $<\lambda$, or even countable) does not prevent
+extending $D$ to an ultrafilter $D_1$ on $I$ which saturates ultrapowers of the
+random graph. ""Saturates"" means that $M^I/\de_1$ is $\lambda^+$-saturated
+whenever M is a model of the theory of the random graph. This was known to be
+true for stable theories, and false for non-simple and non-low theories. This
+result and the techniques introduced in the proof have catalyzed the authors'
+subsequent work on Keisler's order for simple unstable theories. The
+introduction, which includes a part written for model theorists and a part
+written for set theorists, discusses our current program and related results.",1208.5585v1
+2012-09-09,Density dependence of nuclear symmetry energy constrained by mean-field calculations,"We establish a correlation for the symmetry energy at saturation density
+$S_{0}$, slope parameter $L$ and curvature parameter $K_{\text{sym}}$ based on
+widely different mean field interactions. With the help of this correlation and
+available empirical and theoretical information, the density dependent behavior
+around the saturation density is determined. We compare the results obtained
+with the present approach with those by other analyses. With this obtained
+density dependent behavior of the symmetry energy, the neutron skin thickness
+of $^{208}$Pb and some properties of neutron stars are investigated. In
+addition, it is found that the expression $S(\rho)=S_{0}(\rho
+/\rho_{0})^{\gamma}$ or $S(\rho)=12.5(\rho /\rho_{0}) ^{2/3}+C_{p}(\rho
+/\rho_{0}) ^{\gamma}$ does not reproduce the density dependence of the symmetry
+energy as predicted by the mean-field approach around nuclear saturation
+density.",1209.1777v1
+2012-09-18,KNO scaling from a nearly Gaussian action for small-x gluons,"Transverse momentum integrated multiplicities in the central region of pp
+collisions at LHC energies satisfy Koba-Nielsen-Olesen scaling. We attempt to
+relate this finding to multiplicity distributions of soft gluons. KNO scaling
+emerges if the effective theory describing color charge fluctuations at a scale
+on the order of the saturation momentum is approximately Gaussian. From an
+evolution equation for quantum corrections which includes both saturation as
+well as fluctuations we find that evolution with the QCD \beta-function
+satisfies KNO scaling while fixed-coupling evolution does not. Thus, non-linear
+saturation effects and running-coupling evolution are both required in order to
+reproduce geometric scaling of the DIS cross section and KNO scaling of virtual
+dipoles in a hadron wave function.",1209.4105v1
+2012-10-08,CGC predictions for p+A collisions at the LHC and signature of QCD saturation,"We present various predictions for the upcoming p+Pb collisions at \sqrt{S}=5
+TeV within the color glass condensate (CGC) formalism, including single
+inclusive charged hadron production, single inclusive prompt photon production,
+direct photon production, charged hadron multiplicity distribution and
+photon-hadron azimuthal correlations. Using the running-coupling
+Balitsky-Kovchegov evolution equation for calculating various observables, we
+show that the main source of uncertainties is due to less constrained initial
+nuclear saturation scale. This gives rise to rather large theoretical
+uncertainties for nuclear modification factor R_{pA} at the LHC. Nevertheless,
+we propose a simple scheme in which one can still test the main dynamics of the
+CGC/saturation in p+A collisions at the LHC.",1210.2385v2
+2012-10-30,Measuring Quantum Correlations using Lossy Photon-Number-Resolving Detectors with Saturation,"The variance of difference of photocounts (VDPs) is an established measure of
+quantum correlations for quantum states of light. It enables us to discriminate
+between the classical correlation of a two-mode coherent state and the quantum
+correlation of a twin-beam state. We study the effect of loss and saturation of
+the photon-number-resolving detector on the measurement of the VDPs. An
+analytic function is derived for this variance, both for the coherent and the
+twin-beam states. It is found that the VDPs is no longer a reliable
+entanglement measure in the nonlinear regime of the detector response but it
+remains useful in some range of values of average photon numbers of the
+incident light. We also quantify the linear regime of the detector with
+saturation which will be useful for calibration of the detector quantum
+efficiency.",1210.8022v3
+2012-11-08,"On multidimensional generalized Cramér-Rao inequalities, uncertainty relations and characterizations of generalized $q$-Gaussian distributions","In the present work, we show how the generalized Cram\'er-Rao inequality for
+the estimation of a parameter, presented in a recent paper, can be extended to
+the mutidimensional case with general norms on $\mathbb{R}^{n}$, and to a wider
+context. As a particular case, we obtain a new multidimensional Cram\'er-Rao
+inequality which is saturated by generalized $q$-Gaussian distributions. We
+also give another related Cram\'er-Rao inequality, for a general norm, which is
+saturated as well by these distributions. Finally, we derive uncertainty
+relations from these Cram\'er-Rao inequalities. These uncertainty relations
+involve moments computed with respect to escort distributions, and we show that
+some of these relations are saturated by generalized $q$-Gaussian
+distributions. These results introduce extended versions of Fisher information,
+new Cram\'er-Rao inequalities, and new characterizations of generalized
+$q$-Gaussian distributions which are important in several areas of physics and
+mathematics.",1211.2008v2
+2012-11-30,Game saturation of intersecting families,"We consider the following combinatorial game: two players, Fast and Slow,
+claim $k$-element subsets of $[n]=\{1,2,...,n\}$ alternately, one at each turn,
+such that both players are allowed to pick sets that intersect all previously
+claimed subsets. The game ends when there does not exist any unclaimed
+$k$-subset that meets all already claimed sets. The score of the game is the
+number of sets claimed by the two players, the aim of Fast is to keep the score
+as low as possible, while the aim of Slow is to postpone the game's end as long
+as possible. The game saturation number is the score of the game when both
+players play according to an optimal strategy. To be precise we have to
+distinguish two cases depending on which player takes the first move. Let
+$gsat_F(\mathbb{I}_{n,k})$ and $gsat_S(\mathbb{I}_{n,k})$ denote the score of
+the saturation game when both players play according to an optimal strategy and
+the game starts with Fast's or Slow's move, respectively. We prove that
+$\Omega_k(n^{k/3-5}) \le gsat_F(\mathbb{I}_{n,k}),gsat_S(\mathbb{I}_{n,k}) \le
+O_k(n^{k-\sqrt{k}/2})$ holds.",1211.7258v2
+2012-12-05,"Probing Nuclear Symmetry Energy and its Imprints on Properties of Nuclei, Nuclear Reactions, Neutron Stars and Gravitational Waves","Significant progress has been made in recent years in constraining nuclear
+symmetry energy at and below the saturation density of nuclear matter using
+data from both terrestrial nuclear experiments and astrophysical observations.
+However, many interesting questions remain to be studied especially at
+supra-saturation densities. In this lecture note, after a brief summary of the
+currently available constraints on nuclear symmetry energy near the saturation
+density we first discuss the relationship between the symmetry energy and the
+isopin and momentum dependence of the single-nucleon potential in
+isospin-asymmetric nuclear medium. We then discuss several open issues
+regarding effects of the tensor force induced neutron-proton short-range
+correlation (SRC) on nuclear symmetry energy. Finally, as an example of the
+impacts of nuclear symmetry energy on properties of neutron stars and
+gravitational waves, we illustrate effects of the high-density symmetry energy
+on the tidal polarizability of neutron stars in coalescing binaries.",1212.1178v1
+2012-12-10,Simulations of Overstable Inertial-acoustic Modes in Black-Hole Accretion Discs,"We present two-dimensional inviscid hydrodynamic simulations of overstable
+inertial-acoustic oscillation modes (p-modes) in black-hole accretion discs.
+These global spiral waves are trapped in the inner-most region of the disc, and
+are driven overstable by wave absorption at the corotation resonance ($r_c$)
+when the gradient of the background disc vortensity (vorticity divided by
+surface density) at $r_c$ is positive and the disc inner boundary is
+sufficiently reflective. Previous linear calculations have shown that the
+growth rates of these modes can be as high as 10% of the rotation frequency at
+the disc inner edge. We confirm these linear growth rates and the primary disc
+oscillation frequencies in our simulations when the mode amplitude undergoes
+exponential growth. We show that the mode growth saturates when the radial
+velocity perturbation becomes comparable to the disc sound speed. During the
+saturation stage, the primary disc oscillation frequency differs only slightly
+(by less than a few percent) from the linear mode frequency. Sharp features in
+the fluid velocity profiles at this stage suggest that the saturation results
+from nonlinear wave steepening and mode-mode interactions.",1212.2215v1
+2012-12-14,1.5 GHz Pulse Generation From a Monolithic Waveguide Laser With a Graphene-Film Saturable Output Coupler,"We fabricate a saturable absorber mirror by coating a graphene film on an
+output coupler mirror. This is then used to obtain Q-switched mode-locking from
+a diode pumped linear cavity waveguide laser inscribed in Ytterbium-doped
+Bismuthate Glass, with high slope and optical conversion efficiencies. The
+laser produces mode-locked pulses at 1039nm, with 1.5GHz repetition rate at an
+average 202mW output power. This performance is due to the combination of the
+graphene saturable absorber with the high quality laser glass.",1212.3401v1
+2012-12-20,Saturation in central-forward jet production in p-Pb collisions at LHC,"We show that saturation can manifest itself in central-forward dijet
+production in p-A collisions. In spite of large transverse momenta of the jets,
+the almost back-to-back dijet configurations are able to probe gluon density at
+low x and low kt. We perform our study in the framework of high energy
+factorization with the unintegrated gluon density given by a nonlinear QCD
+evolution equation. We show that the formalism can successfully account for
+features measured in e-p and p-p data and it predicts significant suppression
+of the central-forward jet decorrelations in p-Pb compared to p-p, which we
+attribute to saturation of gluon density in the nucleus.",1212.5078v1
+2012-12-21,Role of Joule Heating on Current Saturation and Transient Behavior of Graphene Transistors,"We use simulations to examine current saturation in sub-micron graphene
+transistors on SiO2/Si. We find self-heating is partly responsible for current
+saturation (lower output conductance), but degrades current densities >1 mA/um
+by up to 15%. Heating effects are reduced if the supporting insulator is
+thinned, or in shorter channel devices by partial heat sinking at the contacts.
+The transient behavior of such devices has thermal time constants of ~30-300
+ns, dominated by the thickness of the supporting insulator and that of device
+capping layers (a behavior also expected in ultrathin body SOI transistors).
+The results shed important physical insight into the high-field and transient
+behavior of graphene transistors.",1212.5629v1
+2012-12-24,A puzzle of the pion-photon transition form factor - resolved?,"By means of QCD sum rules in local-duality limit, we analyze the behaviour of
+the form factors for the transitions of a real and a virtual photon to some
+pseudoscalar meson as functions of the involved momentum transfer. Except for
+the findings of BaBar for the neutral-pion form factor, the experimental data
+for all these transition form factors are compatible with saturation for large
+momentum transfer predicted by pQCD factorization. For light pseudoscalar
+mesons, saturation is observed already at relatively small momentum transfer,
+whereas for the eta-c meson it sets in only at larger momentum transfer. A
+recent measurement of the neutral-pion transition form factor by Belle seems to
+resolve this disturbing puzzle as its outcome is compatible with both
+saturation for relatively small momentum transfer and the behaviour of the eta
+and eta' transition form factors at large momentum transfer.",1212.5898v1
+2013-01-04,How strong are the Rossby vortices?,"The Rossby wave instability, associated with density bumps in differentially
+rotating discs, may arise in several different astrophysical contexts, such as
+galactic or protoplanetary discs. While the linear phase of the instability has
+been well studied, the nonlinear evolution and especially the saturation phase
+remain poorly understood. In this paper, we test the non-linear saturation
+mechanism analogous to that derived for wave-particle interaction in plasma
+physics. To this end we perform global numerical simulations of the evolution
+of the instability in a two-dimensional disc. We confirm the physical mechanism
+for the instability saturation and show that the maximum amplitude of vorticity
+can be estimated as twice the linear growth rate of the instability. We provide
+an empirical fitting formula for this growth rate for various parameters of the
+density bump. We also investigate the effects of the azimuthal mode number of
+the instability and the energy leakage in the spiral density waves. Finally, we
+show that our results can be extrapolated to 3D discs.",1301.0689v1
+2013-01-21,On the Saturation of the Nonlinear Refractive Index in Atomic Gases,"Motivated by the ongoing controversy on the origin of the nonlinear index
+saturation and subsequent intensity clamping in femtosecond filaments, we study
+the atomic nonlinear polarization induced by a high-intensity and ultrashort
+laser pulse in hydrogen by numerically solving the time dependent Schr\""odinger
+equation. Special emphasis is given to the efficient modeling of the nonlinear
+polarization at central laser frequency corresponding to 800 nm wavelength.
+Here, the recently proposed model of the Higher-Order Kerr Effect (HOKE) and
+two versions of the Standard model for femtosecond filamentation, including
+either a multi-photon or tunnel ionization rate, are compared. We find that
+around the clamping intensity the instantaneous HOKE model does not reproduce
+the temporal structure of the nonlinear response obtained from the quantum
+mechanical results. In contrast, the non-instantaneous charge contributions
+included in the Standard models ensure a reasonable quantitative agreement.
+Therefore, the physical origin for the observed saturation of the overall
+electron response is confirmed to mainly result from contributions of free or
+nearly free electrons.",1301.4789v1
+2013-02-14,Nonlinear multimodal interference and saturable absorption using a short graded-index multimode optical fiber,"A detailed investigation of the nonlinear multimodal interference in a short
+graded-index multimode optical fiber is presented. The analysis is performed
+for a specific device geometry, where the light is coupled in and out of the
+multimode fiber via single-mode fibers. The same device geometry was recently
+used to obtain ultra-low-loss coupling between two single-mode optical fibers
+with very different mode-field diameters. Our results indicate the potential
+application of this simple geometry for nonlinear devices, such as in nonlinear
+switching, optical signal processing, or as saturable absorbers in mode-locked
+fiber lasers. Saturable absorption in this all-fiber configuration is discussed
+and it is shown that it provides attractive properties that can potentially be
+used in high pulse energy mode-locked fiber lasers.",1302.3493v2
+2013-03-26,Novel carbon materials: new tunneling systems,"This review covers recent achievements in the studies of quantum properties
+of the novel carbon materials (fullerite C60 and bundles of single-walled
+nanotubes (SWNT)) saturated with such light-mass species as helium isotopes,
+the homonuclear molecular hydrogens, and neon. It is shown that even some heavy
+dopants demon-strate kinetic phenomena, in which coherent effects play an
+essential role. Two theoretical concepts are surveyed which have been suggested
+for the explanation of the anomalous phenomena in saturation kinetics and
+linear thermal expansion of doped C60. Most unusual effects have been also
+observed in the low-temperature radial ex-pansion of bundles of single-walled
+carbon nanotubes saturated with the helium isotopes. First, it was shown that
+low-temperature radial expansion of pure SWNT is negative, i.e., a nanotube
+shrinks with warming. Second, sa-turation of SWNT bundles with the helium
+isotopes entails a huge increase of the negative expansion effect, when the
+dopant is He. So far, no detailed physical picture has been put forward. It is
+worth mentioning that the dynamics of a single helium atom on an isolated
+nanotube corresponds to that of a tight-bound quasiparticle with a band width
+of about 10 K.",1303.6581v1
+2013-04-19,Quantum Popov robust stability analysis of an optical cavity containing a saturated Kerr medium,"This paper applies results on the robust stability of nonlinear quantum
+systems to a system consisting an optical cavity containing a saturated Kerr
+medium. The system is characterized by a Hamiltonian operator which contains a
+non-quadratic term involving a quartic function of the annihilation and
+creation operators. A saturated version of the Kerr nonlinearity leads to a
+sector bounded nonlinearity which enables a quantum small gain theorem to be
+applied to this system in order to analyze its stability. Also, a non-quadratic
+version of a quantum Popov stability criterion is presented and applied to
+analyze the stability of this system.",1304.5384v1
+2013-06-18,Transfer and characteristic idempotents for saturated fusion systems,"We construct a well-behaved transfer map from the p-local Burnside ring of
+the underlying p-group S to the p-local Burnside ring of a saturated fusion
+system F. Using this transfer map, we give new results on the characteristic
+idempotent of F -- the unique idempotent in the p-local double Burnside ring of
+S satisfying properties of Linckelmann and Webb. We describe this idempotent
+explicitly both in terms of fixed points and as a linear combination of
+transitive bisets. Additionally, using fixed points we determine the map for
+Burnside rings given by multiplication with the characteristic idempotent, and
+show that this is the transfer map previously constructed. Applying these
+results, we show that for every saturated fusion system the ring generated by
+all (not necessarily idempotent) characteristic elements in the p-local double
+Burnside ring is isomorphic as rings to the p-local ""single"" Burnside ring of
+the fusion system, and we disprove a conjecture by Park-Ragnarsson-Stancu on
+the composition product of fusion systems.",1306.4162v4
+2013-06-18,Heavy quark production and gluon saturation in double parton scattering at LHC,"The production of $c\bar{c}c\bar{c}$, $b\bar{b}b\bar{b}$ and
+$c\bar{c}b\bar{b}$ pairs considering double parton scattering at LHC energies
+is investigated. We estimate the contribution of saturation effects to the
+different final states and predict the energy dependence of the cross sections.
+Moreover, we estimate the ratio between the double and single parton scattering
+cross sections for the full rapidity range of the LHC and for the rapidity
+range of the LHCb experiment. For the full rapidity range we confirm a previous
+prediction, namely that for charm production the double parton scattering
+contribution becomes comparable with the single parton scattering one at LHC
+energies. We also demonstrate that this result remains valid when one
+introduces saturation effects in the calculations. Finally we show that the
+production of $c\bar{c}b\bar{b}$ contributes significantly to bottom
+production. For the LHCb kinematical range the ratio is strongly reduced.",1306.4169v1
+2013-06-27,Quasi-pinning and entanglement in the lithium isoelectronic series,"The Pauli exclusion principle gives an upper bound of 1 on the natural
+occupation numbers. Recently there has been an intriguing amount of theoretical
+evidence that there is a plethora of additional generalized Pauli restrictions
+or (in)equalities, of kinematic nature, satisfied by these numbers. Here for
+the first time a numerical analysis of the nature of such constraints is
+effected in real atoms. The inequalities are nearly saturated, or quasi-pinned.
+For rank-six and rank-seven approximations for lithium, the deviation from
+saturation is smaller than the lowest occupancy number. For a rank-eight
+approximation we find well-defined families of saturation conditions.",1306.6528v2
+2013-07-09,"Far-from-equilibrium Sheared Colloidal Liquids: Disentangling Relaxation, Advection, and Shear-induced Diffusion","Using high-speed confocal microscopy, we measure the particle positions in a
+colloidal suspension under large amplitude oscillatory shear. Using the
+particle positions we quantify the in situ anisotropy of the pair-correlation
+function -- a measure of the Brownian stress. From these data, we find two
+distinct types of responses as the system crosses over from equilibrium to
+far-from-equilibrium states. The first is a nonlinear amplitude saturation that
+arises from shear-induced advection, while the second is a linear frequency
+saturation due to competition between suspension relaxation and shear rate. In
+spite of their different underlying mechanisms, we show that all the data can
+be scaled onto a master curve that spans the equilibrium and
+far-from-equilibrium regimes, linking small amplitude oscillatory to continuous
+shear. This observation illustrates a colloidal analog of the Cox-Merz rule and
+its microscopic underpinning. Brownian Dynamics simulations show that
+interparticle interactions are sufficient for generating both experimentally
+observed saturations.",1307.2500v2
+2013-07-18,1.06 μm Q-switched ytterbium-doped fiber laser using few-layer topological insulator Bi2Se3 as a saturable absorber,"Passive Q-switching of an ytterbium-doped fiber (YDF) laser with few-layer
+topological insulator (TI) is, to the best of our knowledge, experimentally
+demonstrated for the first time. The few-layer TI: Bi2Se3 (2-4 layer thickness)
+is fabricated by the liquid-phase exfoliation method, and has a low saturable
+optical intensity of 53 MW/cm2 measured by the Z-scan technique. The optical
+deposition technique is used to induce the few-layer TI in the solution onto a
+fiber ferrule for successfully constructing the fiber-integrated TI-based
+saturable absorber (SA). By inserting this SA into the YDF laser cavity, stable
+Q-switching operation at 1.06 {\mu}m is achieved. The Q-switched pulses have
+the shortest pulse duration of 1.95 {\mu}s, the maximum pulse energy of 17.9 nJ
+and a tunable pulse-repetition-rate from 8.3 to 29.1 kHz. Our results indicate
+that the TI as a SA is also available at 1 {\mu}m waveband, revealing its
+potential as another wavelength-independent SA (like graphene).",1307.4979v1
+2013-07-20,A Particle-Water Based Model for Water Retention Hysteresis,"A particle-water discrete element based approach to describe water movement
+in partially saturated granular media is presented and tested. Water potential
+is governed by both capillary bridges, dominant at low saturations, and the
+pressure of entrapped air, dominant at high saturations. The approach captures
+the hysteresis of water retention during wetting and drainage by introducing
+the local evolution of liquid-solid contact angles at the level of pores and
+grains. Extensive comparisons against experimental data are presented. While
+these are made without the involvement of any fitting parameters, the method
+demonstrates relative high success by achieving a correlation coefficient of at
+least 82%, and mostly above 90%. For the tested materials with relatively
+mono-disperse grain size, the hysteresis of water retention during cycles of
+wetting and drainage has been shown to arise from the dynamics of solid-liquid
+contact angles as a function of local liquid volume changes.",1307.5372v2
+2013-08-13,Sudakov Double Logarithms Resummation in Hard Processes in Small-x Saturation Formalism,"In this manuscript, we present a complete study of the Sudakov double
+logarithms resummation for various hard processes in eA and pA collisions in
+the small-x saturation formalism. We first employ a couple of slightly
+different formalisms to perform the one-loop analysis of the Higgs boson
+production process in pA collisions, and demonstrate that Sudakov-type
+logarithms arise as the leading correction and that they can be systematically
+resummed in addition to the usual small-x resummation. We further study the
+Sudakov double logarithms for other processes such as heavy quark pair
+production and back-to-back dijet production in eA and pA collisions through
+detailed calculation of the corresponding one-loop diagrams. As the most
+important contribution from the one-loop correction, the Sudakov factor should
+play an important role in the phenomenological study of saturation physics in
+the pA programs at RHIC and the LHC.",1308.2993v1
+2013-09-04,Saturated simple and $k$-simple topological graphs,"A simple topological graph $G$ is a graph drawn in the plane so that any pair
+of edges have at most one point in common, which is either an endpoint or a
+proper crossing. $G$ is called saturated if no further edge can be added
+without violating this condition. We construct saturated simple topological
+graphs with $n$ vertices and $O(n)$ edges. For every $k>1$, we give similar
+constructions for $k$-simple topological graphs, that is, for graphs drawn in
+the plane so that any two edges have at most $k$ points in common. We show that
+in any $k$-simple topological graph, any two independent vertices can be
+connected by a curve that crosses each of the original edges at most $2k$
+times. Another construction shows that the bound $2k$ cannot be improved.
+Several other related problems are also considered.",1309.1046v2
+2013-10-30,Superfast non-linear diffusion: Capillary transport in particulate porous media,"The migration of liquids in porous media, such as sand, has been commonly
+considered at high saturation levels with liquid pathways at pore dimensions.
+In this letter we reveal a low saturation regime observed in our experiments
+with droplets of extremely low volatility liquids deposited on sand. In this
+regime the liquid is mostly found within the grain surface roughness and in the
+capillary bridges formed at the contacts between the grains. The bridges act as
+variable-volume reservoirs and the flow is driven by the capillary pressure
+arising at the wetting front according to the roughness length scales. We
+propose that this migration (spreading) is the result of interplay between the
+bridge volume adjustment to this pressure distribution and viscous losses of a
+creeping flow within the roughness. The net macroscopic result is a special
+case of non-linear diffusion described by a superfast diffusion equation (SFDE)
+for saturation with distinctive mathematical character. We obtain solutions to
+a moving boundary problem defined by SFDE that robustly convey a time power law
+of spreading as seen in our experiments.",1310.8262v1
+2013-11-04,Flux saturation length of sediment transport,"Sediment transport along the surface drives geophysical phenomena as diverse
+as wind erosion and dune formation. The main length-scale controlling the
+dynamics of sediment erosion and deposition is the saturation length
+$L_\mathrm{s}$, which characterizes the flux response to a change in transport
+conditions. Here we derive, for the first time, an expression predicting
+$L_\mathrm{s}$ as a function of the average sediment velocity under different
+physical environments. Our expression accounts for both the characteristics of
+sediment entrainment and the saturation of particle and fluid velocities, and
+has only two physical parameters which can be estimated directly from
+independent experiments. We show that our expression is consistent with
+measurements of $L_\mathrm{s}$ in both aeolian and subaqueous transport regimes
+over at least five orders of magnitude in the ratio of fluid and particle
+density, including on Mars.",1311.0661v1
+2013-12-17,"Measurements on Melting Pressure, Metastable Solid Phases, and Molar Volume of Univariant Saturated Helium Mixture","A concentration-saturated helium mixture at the melting pressure consists of
+two liquid phases and one or two solid phases. The equilibrium system is
+univariant, whose properties depend uniquely on temperature. Four coexisting
+phases can exist on singular points, which are called quadruple points. As a
+univariant system, the melting pressure could be used as a thermometric
+standard. It would provide some advantages compared to the current reference,
+namely pure $^3$He, especially at the lowest temperatures below 1 mK. We have
+extended the melting pressure measurements of the concentration-saturated
+helium mixture from 10 mK to 460 mK. The density of the dilute liquid phase was
+also recorded. The effect of the equilibrium crystal structure changing from
+hcp to bcc was clearly seen at T=294 mK at the melting pressure P=2.638 MPa. We
+observed the existence of metastable solid phases around this point. No
+evidence was found for the presence of another, disputed, quadruple point at
+around 400 mK. The experimental results agree well with our previous
+calculations at low temperatures, but deviate above 200 mK.",1312.4763v2
+2014-01-04,Optical Solitons in a Trinal-channel Inverted Nonlinear Photonic Crystal,"Inverted nonlinear photonic crystals are the crystals featuring competition
+between linear and nonlinear lattices, with minima of the linear potential
+coinciding with maxima of the nonlinear pseudopotential, and vice versa.
+Traditional inverted nonlinear photonic crystals only have two channels, and
+can be attained experimentally by means of Rhodamine B (RhB, a dye featuring
+saturable absorption) doped into the SU-8 polymer. In this paper, a new type of
+inverted nonlinear photonic crystal is constructed by juxtaposing three kinds
+of channels into a period. These three channels are a purely linear channel, a
+saturable self-focusing nonlinear channel, and a saturable self-defocusing
+nonlinear channel. This optical device is assumed to be fabricated by means of
+SU-8 polymer material periodically doped with two types of active dyes. The
+nonlinear propagation of a light field inside this device (passing along the
+channel) can be described by a nonlinear Schrodinger equation. Stable
+multi-peak fundamental and dipole solitons are found in the first gap of the
+system. These solitons sufficiently exhibit some interesting digital
+properties, which may have potential in optical communications.",1401.0786v1
+2014-02-09,Possibility of a superfluid in high multiplicity p-p and p-Pb collisions,"We consider the case where the saturated and unequilibriated initial stage of
+a high multiplicity p-p and p-Pb collision, may, due to high occupation number,
+display superfluid properties. The special case of an unequilibrated plasma of
+SU(2) gluons formed in the collision of two nuclei with deeply saturated gluon
+wave functions is considered. Color gauge symmetry is broken by the presence of
+a net non-vanishing, space-time dependent color expectation value. A two
+component scenario is envisioned, containing momentum states that are densely
+occupied below the saturation scale and a dilute normal fluid of excitations
+within this state. The spectrum of these excitations is shown to have an energy
+gap and thus it is hard to excite quanta out of the condensed state.
+Consequences for the stress energy tensor are outlined, in particular the
+possibility of a near invisid flow is discussed.",1402.1912v3
+2014-02-14,Enhanced quantum coherence in graphene caused by Pd cluster deposition,"We report on the unexpected increase in the dephasing lengths of a graphene
+sheet caused by the deposition of Pd nanoclusters, as demonstrated by weak
+localization measurements. The dephasing lengths reached saturated values at
+low temperatures. Theoretical calculations indicate the p-type charge transfer
+from the Pd clusters, which contributes more carriers. The saturated values of
+dephasing lengths often depend on both the carrier concentration and mean free
+path. Although some impurities are increased as revealed by decreased
+mobilities, the intense charge transfer leads to the improved saturated values
+and subsequent improved dephasing lengths.",1402.3386v2
+2014-02-20,Lasing of ambient air with microjoule pulse energy pumped by a multi terawatt IR femtosecond laser,"We report on the lasing action of atmospheric air pumped by an 800 nm
+femtosecond laser pulse with peak power up to 4 TW. Lasing emission at 428 nm
+increases rapidly over a small range of pump laser power, followed by
+saturation above ~ 1.5 TW. The maximum lasing pulse energy is measured to be
+2.6 uJ corresponding to an emission power in the MW range, while a maximum
+conversion efficiency of is measured at moderate pump pulse energy. The optical
+gain inside the filament plasma is estimated to be excess of 0.7/cm. The lasing
+emission shows a doughnut profile, reflecting the spatial distribution of the
+pump-generated white-light continuum that acts as a seed for the lasing. We
+attribute the pronounced saturation to the defocusing of the seed in the plasma
+amplifying region and to the saturation of the seed intensity.",1402.5019v1
+2014-02-20,Saturation effects in forward-forward dijet production in p+Pb collisions,"We study saturation effects in the production of forward dijets in
+proton-lead collisions at the Large Hadron Collider, using the framework of
+High Energy Factorization. Such configurations, with both jets produced in the
+forward direction, probe the gluon density of the lead nucleus at small
+longitudinal momentum fraction, and also limit the phase space for emissions of
+additional jets. We find significant suppression of the forward dijet azimuthal
+correlations in proton-lead versus proton-proton collisions, which we attribute
+to stronger saturation of the gluon density in the nucleus than in the proton.
+In order to minimize model dependence of our predictions, we use two different
+extensions of the Balitsky-Kovchegov equation for evolution of the gluon
+density with sub-leading corrections.",1402.5065v2
+2014-02-24,Spiraling elliptic breathers in saturable nonlinear media with linear anisotropy,"We have introduced a class of spiraling elliptic breathers in saturable
+nonlinear media with linear anisotropy. Two kinds of evolution behaviors of the
+breathers, rotating and pendulum-like librating, are both predicted by the
+variational approach, and confirmed by the numerical simulation.The spiraling
+elliptic breathers can rotate even though they have no initial orbital angular
+momentum (OAM). Due to the linear anisotropy of the media, the OAM is no longer
+conserved. Therefore, the angular velocity is found to be not a constant but a
+periodic function of the propagation distance. When the linear anisotropy is
+large enough, the spiraling elliptic breathers can librate like the pendulum.
+The spiraling elliptic breathers exist in the media with not only the saturable
+nonlinearity but also the nonlocal nonlinearity, as a matter of fact, they are
+universal in the nonlinear media with the linear anisotropy.",1402.5736v1
+2014-02-26,Femtosecond pulse generation from a Topological Insulator mode-locked fiber laser,"We reported on the generation of femtosecond pulse in an anomalous-dispersion
+fiber ring laser by using a polyvinyl alcohol (PVA)-based Topological Insulator
+(TI), Bi2Se3 saturable absorber (SA). The PVA-TI composite has a low saturable
+optical intensity of 12 MW/cm2 and a modulation depth of ~3.9%. By
+incorporating the fabricated PVA-TISA into a fiber laser, mode-locking
+operation could be achieved at a low pump threshold of 25 mW. After an
+optimization of the cavity parameters, optical pulse with ~660 fs centered at
+1557.5 nm wavelength had been generated. The experimental results demonstrate
+that the PVA could be an excellent host material for fabricating
+high-performance TISA, and also indicate that the filmy PVA-TISA is indeed a
+good candidate for ultrafast saturable absorption device.",1402.6529v1
+2014-02-28,Charge Symmetry Breaking and Parity Violating Electron-Proton Scattering,"Charge symmetry breaking contributions to the proton's neutral weak form
+factors must be understood in order for future measurements of parity violating
+electron-proton scattering to be definitively interpreted as evidence of proton
+strangeness. We calculate these charge symmetry breaking form factor
+contributions using chiral perturbation theory with resonance saturation
+estimates for unknown low-energy constants. The uncertainty of the
+leading-order resonance saturation estimates is reduced by incorporating
+nuclear physics constraints. Higher-order contributions are investigated
+through phenomenological vertex form factors. We predict that charge symmetry
+breaking form factor contributions are an order of magnitude larger than
+expected from naive dimensional analysis but are still an order of magnitude
+smaller than current experimental bounds on proton strangeness. This is
+consistent with previous calculations using chiral perturbation theory with
+resonance saturation.",1402.7169v3
+2014-03-05,Geometrical Scaling of Direct-Photon Production in Hadron Collisions from RHIC to the LHC,"We consider pp, dAu and AuAu production of photons at RHIC energies, and PbPb
+collisions at LHC energy. We show that the inclusive spectrum of photons in the
+transverse momentum range of 1 GeV < pT <= 4 GeV satisfies geometric scaling.
+Geometric scaling is a property of hadronic interactions predicted by theories
+of gluon saturation, and expresses rates in terms of dimensionless ratios of
+the transverse momentum to saturation momentum. We show excellent agreement
+with geometric scaling with the only input being the previously measured
+dependence of the saturation momentum upon Bjorken x and centrality.",1403.1174v2
+2014-04-15,"Tensor invariants, Saturation problems, and Dynkin automorphisms","Let G be a connected almost simple algebraic group with a Dynkin automorphism
+{\sigma}. Let G_{\sigma} be the connected almost simple algebraic group
+associated to G and {\sigma}. We prove that the dimension of the tensor
+invariant space of G_{\sigma} is equal to the trace of {\sigma} on the
+corresponding tensor invariant space of G. We prove that if G has the
+saturation property then so does G{\sigma}. As a consequence, we show that the
+spin group Spin(2n + 1) is of saturation property with factor 2, which
+strengthens the results of Belkale-Kumar and Sam in the case of type B_n.",1404.4098v2
+2014-04-21,Phase conversion dissipation in multicomponent compact stars,"We propose a mechanism for the damping of density oscillations in
+multicomponent compact stars. The mechanism is the periodic conversion between
+different phases, i.e., the movement of the interface between them, induced by
+pressure oscillations in the star. The damping grows nonlinearly with the
+amplitude of the oscillation. We study in detail the case of r-modes in a
+hybrid star with a sharp interface, and we find that this mechanism is powerful
+enough to saturate the r-mode at very low saturation amplitude, of order
+$10^{-10}$, and is therefore likely to be the dominant r-mode saturation
+mechanism in hybrid stars with a sharp interface.",1404.5279v4
+2014-05-16,General model of phospholipid bilayers in fluid phase within the single chain mean field theory,"Coarse-grained model for saturated (DCPC, DLPC, DMPC, DPPC, DSPC) and
+unsaturated (POPC, DOPC) phospholipids is introduced within the Single Chain
+Mean Field theory. A single set of parameters adjusted for DMPC bilayers gives
+an adequate description of equilibrium and mechanical properties of a range of
+saturated lipid molecules that differ only in length of their hydrophobic tails
+and unsaturated (POPC, DOPC) phospholipids which have double bonds in the
+tails. A double bond is modeled with a fixed angle of 120 degrees, while the
+rest of the parameters are kept the same as saturated lipids. The thickness of
+the bilayer and its hydrophobic core, the compressibility and the equilibrium
+area per lipid correspond to experimentally measured values for each lipid,
+changing linearly with the length of the tail. The model for unsaturated
+phospholipids also fetches main thermodynamical properties of the bilayers.
+This model is used for an accurate estimation of the free energies of the
+compressed or stretched bilayers in stacks or multilayers and gives reasonable
+estimates for free energies. The proposed model may further be used for studies
+of mixtures of lipids, small molecule inclusions, interactions of bilayers with
+embedded proteins.",1405.4106v1
+2014-05-29,Dispersion-induced dynamics of coupled modes in a semiconductor laser with saturable absorption,"We present an experimental and theoretical study of modal nonlinear dynamics
+in a specially designed dual-mode semiconductor Fabry-Perot laser with a
+saturable absorber. At zero bias applied to the absorber section, we have found
+that with increasing device current, single mode self-pulsations evolve into a
+complex dynamical state where the total intensity experiences regular bursts of
+pulsations on a constant background. Spectrally resolved measurements reveal
+that in this state the individual modes of the device can follow highly
+symmetric but oppositely directed spiralling orbits. Using a generalization of
+the rate equation description of a semiconductor laser with saturable
+absorption to the multimode case, we show that these orbits appear as a
+consequence of the interplay between the material dispersion in the gain and
+absorber sections of the laser. Our results provide insights into the factors
+that determine the stability of multimode states in these systems, and they can
+inform the development of semiconductor mode-locked lasers with tailored
+spectra.",1405.7641v1
+2014-06-06,Saturated Subgraphs of the Hypercube,"We say $G$ is \emph{$(Q_n,Q_m)$-saturated} if it is a maximal $Q_m$-free
+subgraph of the $n$-dimensional hypercube $Q_n$. A graph, $G$, is said to be
+$(Q_n,Q_m)$-semi-saturated if it is a subgraph of $Q_n$ and adding any edge
+forms a new copy of $Q_m$. The minimum number of edges a $(Q_n,Q_m)$-saturated
+graph (resp. $(Q_n,Q_m)$-semi-saturated graph) can have is denoted by
+$sat(Q_n,Q_m)$ (resp. $s\text{-}sat(Q_n,Q_m)$). We prove that $
+\lim_{n\to\infty}\frac{sat(Q_n,Q_m)}{e(Q_n)}=0$, for fixed $m$, disproving a
+conjecture of Santolupo that, when $m=2$, this limit is $\frac{1}{4}$. Further,
+we show by a different method that $sat(Q_n, Q_2)=O(2^n)$, and that
+$s\text{-}sat(Q_n, Q_m)=O(2^n)$, for fixed $m$. We also prove the lower bound
+$s-sat(Q_n,Q_2)\geq \frac{m+1}{2}\cdot 2^n$, thus determining $sat(Q_n,Q_2)$ to
+within a constant factor, and discuss some further questions.",1406.1766v2
+2014-06-24,High-field charge transport on the surface of Bi$_2$Se$_3$,"We present a theoretical study on the high-field charge transport on the
+surface of Bi$_2$Se$_3$ and reproduce all the main features of the recent
+experimental results, i.e., the incomplete current saturation and the finite
+residual conductance in the high applied field regime [Costache {\it et al.},
+Phys. Rev. Lett. {\bf 112}, 086601 (2014)]. Due to the hot-electron effect, the
+conductance decreases and the current shows the tendency of the saturation with
+the increase of the applied electric field. Moreover, the electric field can
+excite carriers within the surface bands through interband precession and leads
+to a higher conductance. As a joint effect of the hot-electron transport and
+the carrier excitation, the conductance approaches a finite residual value in
+the high-field regime and the current saturation becomes incomplete. We thus
+demonstrate that, contrary to the conjecture in the literature, the observed
+transport phenomena can be understood qualitatively in the framework of surface
+transport alone. Furthermore, if a constant bulk conductance which is
+insensitive to the field is introduced, one can obtain a good quantitative
+agreement between the theoretical results and the experimental data.",1406.6223v1
+2014-06-28,Azimuthal angle correlations in hadron-nucleus scattering: enhanced diagrams,"In this paper we calculate the contribution to rapidity and angular
+correlations of the first Pomeron loop diagram in the dense partonic
+environment. This diagram is expected to give the largest contribution to the
+density variation mechanism of the angular correlations. We show that this
+diagrams leads to sizable contributions to the rapidity correlation functions
+of the order of $\sigma_{in} /\Lb \pi R^2\Rb$ where $\sigma_{in}$ is the
+inelastic cross section and $R$ is the size of the typical dipole inside the
+proton saturation scale. Therefore, the correlations do not depend on the
+saturation scale. We demonstrated that density variation mechanism does not
+lead to suppression of the angular dependance of the double inclusive cross
+section generating the coefficient in front of $\cos^2 \varphi$ in $A^{1/3}$
+larger in the case of hadron-nucleus collision than in hadron-hadron
+interaction. The angular correlations are suppressed in comparison with the
+rapidity ones but only due to large multiplicity of the produced gluons. We
+consider this paper as the first attempt of quantitative description of the
+density variation mechanism in CGC/saturation approach.",1406.7358v1
+2014-08-25,Saturation numbers in tripartite graphs,"Given graphs $H$ and $F$, a subgraph $G\subseteq H$ is an $F$-saturated
+subgraph of $H$ if $F\nsubseteq G$, but $F\subseteq G+e$ for all $e\in
+E(H)\setminus E(G)$. The saturation number of $F$ in $H$, denoted
+$\text{sat}(H,F)$, is the minimum number of edges in an $F$-saturated subgraph
+of $H$. In this paper we study saturation numbers of tripartite graphs in
+tripartite graphs. For $\ell\ge 1$ and $n_1$, $n_2$, and $n_3$ sufficiently
+large, we determine $\text{sat}(K_{n_1,n_2,n_3},K_{\ell,\ell,\ell})$ and
+$\text{sat}(K_{n_1,n_2,n_3},K_{\ell,\ell,\ell-1})$ exactly and
+$\text{sat}(K_{n_1,n_2,n_3},K_{\ell,\ell,\ell-2})$ within an additive constant.
+We also include general constructions of $K_{\ell,m,p}$-saturated subgraphs of
+$K_{n_1,n_2,n_3}$ with few edges for $\ell\ge m\ge p>0$.",1408.5927v1
+2014-09-16,Photoluminescence Saturation and Exciton Decay Dynamics in Transition Metal Dichalcogenide Monolayers,"We report a photoluminescence (PL) and transient reflection spectroscopy
+study of exciton dynamics in monolayer transition transition-metal
+dichalcogenides (TMDs). PL saturation in monolayer MoSe2 occurs an excitation
+intensity more than two orders of magnitude lower than in monolayer MoS2.
+Transient reflection shows that the nonlinear exciton-exciton annihilation is
+the dominant exciton decay process in monolayer MoSe2 in contrast to the
+previously reported linear exciton decay in monolayer MoS2. In addition, the
+exciton lifetime in MoSe2, > 125 ps, is more than an order of magnitude longer
+than the several-ps exciton lifetime in MoS2. We find that the dramatically
+different exciton decay mechanism and PL saturation behavior of MoSe2 and MoS2
+monolayers can be explained by the difference in their exciton lifetime.",1409.4546v2
+2014-10-03,Analytical Evaluation of Saturation Throughput of a Cognitive 802.11-based WLAN Overlaid on a WiMAX-TDD Network,"This paper analyzes the saturation throughput of a cognitive single hop WLAN
+overlaid on a primary IEEE 802.16e TDD WiMAX network. After the contention
+among the secondary nodes, the winner node transmits its data packet in the
+empty slots of downlink subframes of WiMAX. Regarding the OFDMA structure as
+well as time-scheduled resources in WiMAX, the time duration of opportunities
+for the secondary network does not follow simple exponential on-off pattern. To
+model the dynamic behavior of opportunities for secondary nodes as well as
+contentions to exploit the opportunities, we propose an analytical model
+comprised of a discrete-time Markov chain and two inter-related open
+multi-class queueing networks. The effects of random number of empty slots at
+different frames as the result of random amount of download data, random packet
+transmission time at WLAN due to random opportunities in different frames, the
+dependency of the number of empty slots at consecutive WiMAX frames, and the
+details of 802.11 MAC protocol are included in our analytical approach. We
+compare the effect of two resource allocations, i.e., horizontal and vertical
+striping on the saturation throughput of the cognitive WLAN. Simulation results
+confirm the accuracy of our analytical approach in different conditions.",1410.0826v1
+2014-11-21,WS2 as a saturable absorber for ultrafast photonic applications of mode-locked and Q-switched lasers,"Two-dimensional (2D) nanomaterials, especially the transition metal sulfide
+semiconductors, have drawn great interests due to their potential applications
+in viable photonic and optoelectronic devices, such as saturable absorbers
+(SAs) and optical switches, etc. In this work, tungsten disulfide (WS2) based
+SA for ultrafast photonic applications was demonstrated. WS2 nanosheets were
+prepared using liquid-phase exfoliation method and embedded in polyvinyl
+alcohol (PVA) thin film for the practical usage. Saturable absorption was
+observed in the WS2-PVA SA at the telecommunication waveband near 1550 nm. By
+incorporating WS2-PVA SA into a fiber laser cavity, both stable mode locking
+operation and Q-switching operation were achieved. In the mode locking
+operation, the laser obtained femtosecond output pulse width and high spectral
+purity in the radio frequency spectrum. In the Q-switching operation, the laser
+had tunable repetition rate and output pulse energy of a few tens of nano
+joule. Our findings suggest that few-layer WS2 nanosheets embedded in PVA thin
+film are promising nonlinear optical materials for ultrafast photonic
+applications as a mode locker or Q-switcher.",1411.5777v1
+2014-11-27,Saturated locally optimal designs under differentiable optimality criteria,"We develop general theory for finding locally optimal designs in a class of
+single-covariate models under any differentiable optimality criterion. Yang and
+Stufken [Ann. Statist. 40 (2012) 1665-1681] and Dette and Schorning [Ann.
+Statist. 41 (2013) 1260-1267] gave complete class results for optimal designs
+under such models. Based on their results, saturated optimal designs exist;
+however, how to find such designs has not been addressed. We develop tools to
+find saturated optimal designs, and also prove their uniqueness under mild
+conditions.",1411.7601v1
+2014-12-10,Heat transfer coefficient saturation in superconducting Nb tunnel junctions contacted to a NbTiN circuit and an Au energy relaxation layer,"In this paper we present the experimental realization of a Nb tunnel junction
+connected to a high-gap superconducting NbTiN embedding circuit. We investigate
+relaxation of nonequilibrium quasiparticles in a small volume Au layer between
+the Nb tunnel junction and the NbTiN circuit. We find a saturation in the
+effective heat-transfer coefficient consistent with a simple theoretical model.
+This saturation is determined by the thickness of the Au layer. Our findings
+are important for the design of the ideal Au energy relaxation layer for
+practical SIS heterodyne mixers and we suggest two geometries, one, using a
+circular Au layer and, two, using a half-circular Au layer. Our work is
+concluded with an outlook of our future experiments.",1412.3388v1
+2014-12-15,Saturable Lorentz model for fully explicit three-dimensional modeling of nonlinear optics,"Inclusion of the instantaneous Kerr nonlinearity in the FDTD framework leads
+to implicit equations that have to be solved iteratively. In principle,
+explicit integration can be achieved with the use of anharmonic oscillator
+equations, but it tends to be unstable and inappropriate for studying
+strong-field phenomena like laser filamentation. In this paper, we show that
+nonlinear susceptibility can be provided instead by a harmonic oscillator
+driven by a nonlinear force, chosen in a way to reproduce the polarization
+obtained from the solution of the quantum mechanical two level equations. The
+resulting saturable, nonlinearly-driven, harmonic oscillator model reproduces
+quantitatively the quantum mechanical solutions of harmonic generation in the
+under-resonant limit, up to the 9th harmonic. Finally, we demonstrate that
+fully explicit leapfrog integration of the saturable harmonic oscillator is
+stable, even for the intense laser fields that characterize laser filamentation
+and high harmonic generation.",1412.4748v3
+2015-01-27,Rapidity dependence of saturation in inclusive HERA data with the rcBK equation,"The contribution of the different terms of the running-coupling
+Balistky-Kovchegov (rcBK) equation to the description of inclusive HERA data is
+discussed. Within this framework an alternative definition of the saturation
+scale is presented. The definition is based on the ratio of the term
+corresponding to the recombination of two dipoles to the term corresponding to
+a dipole splitting. A similar ratio is used to study the contribution of the
+recombination term to the evolution of inclusive HERA data with rapidity. It is
+found that, although the data are well described, the behaviour of the
+different terms of the rcBK equation for HERA kinematics is not what it is
+naively expected from saturation arguments.",1501.06687v3
+2015-01-30,Inverse diffraction for the Atmospheric Imaging Assembly in the Solar Dynamics Observatory,"The Atmospheric Imaging Assembly in the Solar Dynamics Observatory provides
+full Sun images every 1 seconds in each of 7 Extreme Ultraviolet passbands.
+However, for a significant amount of these images, saturation affects their
+most intense core, preventing scientists from a full exploitation of their
+physical meaning. In this paper we describe a mathematical and automatic
+procedure for the recovery of information in the primary saturation region
+based on a correlation/inversion analysis of the diffraction pattern associated
+to the telescope observations. Further, we suggest an interpolation-based
+method for determining the image background that allows the recovery of
+information also in the region of secondary saturation (blooming).",1501.07805v1
+2015-01-30,A Study of the Matter of SPH Application to Saturated Soil Problems,"We present an application of SPH to saturated soilproblems. Herein, the
+standard SPH formulation was improved to model saturated soil. It is shown that
+the proposed formulation could yield several advantages such as: it takes into
+account the pore-water pressure in an accurate manner, it automatically
+satisfies the dynamics boundary conditions between submerged soil and water,
+and it reduced the computational cost. Discussions on the use of the standard
+and the new SPH formulations are also given through some numerical tests.
+Furthermore, some techniques to obtained correct SPH solution are also proposed
+and discussed. To the end, this paper suggests that the proposed SPH
+formulation should be considered as the basic formulation for further
+developments of SPH for soil-water couple problems",1502.00495v1
+2015-02-13,Superstability in Tame Abstract Elementary Classes,"In this paper we address a problem posed by Shelah in 1999 to find a suitable
+notion for superstability for abstract elementary classes in which limit models
+of cardinality $\mu$ are saturated.
+  Theorem 1. Suppose that $\mathcal{K}$ is a $\chi$-tame abstract elementary
+class with no maximal models satisfying the joint embedding property and the
+amalgamation property. Suppose $\mu$ is a cardinal with
+$\mu\geq\beth_{(2^{LS(\mathcal{K})+\chi})^+}$. Let $M$ be a model of
+cardinality $\mu$. If $\mathcal{K}$ is both $\chi$-stable and $\mu$-stable and
+satisfies the $\mu$-superstability assumptions, then any two $\mu$-limit models
+over $M$ are isomorphic over $M$.
+  Moreover, we identify sufficient conditions for superlimit models of
+cardinality $\mu$ to exist, for model homogeneous models to be superlimit, and
+for a union of saturated models to be saturated.",1502.04144v2
+2015-02-18,CGC/saturation approach for soft interactions at high energy: a two channel model,"In this paper we continue the development of a model for strong interactions
+at high energy, based on two ingredients: CGC/saturation approach and the BFKL
+Pomeron. In our approach, the unknown mechanism of confinement of quarks and
+gluons, is characterized by several numerical parameters, which are extracted
+from the experimental data. We demonstrate that the two channel model,
+successfully describes the experimental data, including both the value of the
+elastic slope and the energy behavior of the single diffraction cross section.
+We show that the disagreement with experimental data of our previous single
+channel eikonal model [6] stems from the simplified approach used for the
+hadron structure, and is not related to our principal theoretical input, based
+on the CGC/saturation approach.",1502.05202v1
+2015-03-17,V-type electromagnetically induced transparency and saturation effect at the gas-solid interface,"We theoretically study electromagnetically induced transparency (EIT) in
+reflection spectra of V-type system at the gas-solid interface. In addition to
+a narrow dip arising from the EIT effect, we find the other particular
+saturation effect induced by pump field, which does not exist in $\Lambda$ or
+$\Xi$ -type system reflection spectra. The saturation effect only induces an
+intensity decrement in the reflection spectra, and there is no influence on the
+narrow dip arising from the EIT effect. We detailedly calculate and analyze the
+dependence of V-type system reflection spectra on probe field intensity, pump
+field intensity, coherent decay rate, and the initial population after the
+collision between atoms and the interface.",1503.04950v2
+2015-04-23,Simulation Study of Schottky Contact Based Single Si Wire Solar Cell,"We simulate single silicon nanowire (SiNW) solar cells with dissimilar work
+function metal contacts. Both short circuit current (ISC) and open circuit
+voltage (VOC) have been investigated. Effects of nanowire dimension, minority
+carrier lifetime, and contact metal work function difference are understood
+through simulations. Both ISC and VOC increase with nanowire length but
+saturate due to minority carrier recombination. The saturation length is found
+to be five times the diffusion length. The larger the contact work function
+difference, the more improved the solar cell characteristics. Large work
+function differences may also avoid need for any doping in axial p-i-n nanowire
+solar cells. Saturation in ISC as well as degradation in current density with
+length can be minimized by spreading the contacts along the length of the
+nanowire.",1504.06281v1
+2015-05-02,Saturated Sodium Chloride Solution under an External Static Electric Field: a Molecular Dynamics Study,"The behavior of saturated aqueous sodium chloride solutions under a constant
+external electric field (E) was studied by molecular dynamics (MD) simulation.
+Our dynamic MD simulations have indicated that the irreversible nucleation
+process towards crystallization is accelerated by a moderate E, but retarded or
+even prohibited under a stronger E, which can be understood by the competition
+between self-diffusion and drift motion. The former increases with E resulting
+in the acceleration of the nucleation process, and the latter tears oppositely
+charged ions more apart under a stronger E leading to the deceleration of
+nucleation. Moreover, our steady-state MD simulations have indicated that a
+first-order phase transition happens in saturated solutions only when the
+applied E is below a certain threshold Ec, and the ratio of crystallized ions
+does not change with the electric field. The magnitude of Ec increases with
+concentration, because larger clusters are easy to form in a more concentrated
+solution and require a stronger E to dissociate them.",1505.00347v1
+2015-05-11,Event-by-event fluctuations in perturbative QCD + saturation + hydro model: pinning down QCD matter shear viscosity in ultrarelativistic heavy-ion collisions,"We introduce an event-by-event perturbative-QCD + saturation + hydro (""EKRT"")
+framework for ultrarelativistic heavy-ion collisions, where we compute the
+produced fluctuating QCD-matter energy densities from next-to-leading order
+perturbative QCD using a saturation conjecture to control soft particle
+production, and describe the space-time evolution of the QCD matter with
+dissipative fluid dynamics, event by event. We perform a simultaneous
+comparison of the centrality dependence of hadronic multiplicities, transverse
+momentum spectra, and flow coefficients of the azimuth-angle asymmetries,
+against the LHC and RHIC measurements. We compare also the computed
+event-by-event probability distributions of relative fluctuations of elliptic
+flow, and event-plane angle correlations, with the experimental data from Pb+Pb
+collisions at the LHC. We show how such a systematic multi-energy and
+multi-observable analysis tests the initial state calculation and the
+applicability region of hydrodynamics, and in particular how it constrains the
+temperature dependence of the shear viscosity-to-entropy ratio of QCD matter in
+its different phases in a remarkably consistent manner.",1505.02677v1
+2015-06-23,"Nonlinear Processes in Multi-Quantum-Well Plasmonic Metasurfaces:Electromagnetic Response, Saturation Effects, Limits and Potentials","Nonlinear metasurfaces based on coupling a locally enhanced plasmonic
+response to intersubband transitions of n-doped multi-quantum-wells (MQWs) have
+recently provided second-order susceptibilities orders of magnitude larger than
+any other nonlinear flat structure measured so far. Here, we present a
+comprehensive theory to characterize the electromagnetic response of nonlinear
+processes occurring in ultrathin MQW-based plasmonic metasurfaces, providing a
+homogeneous model that takes phase-matching at the unit-cell level and the
+influence of saturation and losses into account. In addition, the limits
+imposed by saturation of the MQW transitions on the nonlinear response of these
+metasurfaces are analytically derived, revealing useful guidelines to design
+devices with enhanced performance. Our approach is first validated using
+experimental data and then applied to theoretically investigate novel designs
+able to achieve significant second-harmonic generation efficiency in the
+infrared frequency band.",1506.07095v2
+2015-07-06,3D super-resolved in vitro multiphoton microscopy by saturation of excitation,"We demonstrate a significant resolution enhancement beyond the conventional
+limit in multiphoton microscopy (MPM) using saturated excitation of
+fluorescence. Our technique achieves super-resolved imaging by temporally
+modulating the excitation laser-intensity and demodulating the higher harmonics
+from the saturated fluorescence signal. The improvement of the lateral and
+axial resolutions is measured on a sample of fluorescent microspheres. While
+the third harmonic already provides an enhanced resolution, we show that a
+further improvement can be obtained with an appropriate linear combination of
+the demodulated harmonics. Finally, we present in vitro imaging of fluorescent
+microspheres incorporated in HeLa cells to show that this technique performs
+well in biological samples.",1507.01408v3
+2015-07-28,Gluon saturation and Feynman scaling in leading neutron production,"In this paper we extend the color dipole formalism to the study of leading
+neutron production in $e + p \rightarrow e + n + X$ collisions at high energies
+and estimate the related observables, which were measured at HERA and may be
+analysed in future electron-proton ($ep$) colliders. In particular, we
+calculate the Feynman $x_F$ distribution of leading neutrons, which is
+expressed in terms of the pion flux and the photon-pion total cross section. In
+the color dipole formalism, the photon-pion cross section is described in terms
+of the dipole-pion scattering amplitude, which contains information about the
+QCD dynamics at high energies and gluon saturation effects. We consider
+different models for the scattering amplitude, which have been used to describe
+the inclusive and diffractive $ep$ HERA data. Moreover, the model dependence of
+our predictions with the description of the pion flux is analysed in detail. We
+show that the recently released H1 leading neutron spectra can be reproduced
+using the color dipole formalism and that these spectra could help us to
+observe more clearly gluon saturation effects in future $ep$ colliders.",1507.07758v1
+2015-08-07,Surfactant-aided exfoliation of molydenum disulphide for ultrafast pulse generation through edge-state saturable absorption,"We use liquid phase exfoliation to produce dispersions of molybdenum
+disulphide (MoS2) nanoflakes in aqueous surfactant solutions. The chemical
+structures of the bile salt surfactants play a crucial role in the exfoliation
+and stabilization of MoS2. The resultant MoS2 dispersions are heavily enriched
+in single and few (<6) layer flakes with large edge to surface area ratio. We
+use the dispersions to fabricate free-standing polymer composite wide-band
+saturable absorbers to develop mode-locked and Q- switched fibre lasers,
+tunable from 1535-1565 and 1030-1070 nm, respectively. We attribute this
+sub-bandgap optical absorption and its nonlinear saturation behaviour to
+edge-mediated states introduced within the material band-gap of the exfoliated
+MoS2 nanoflakes.",1508.01631v2
+2015-08-10,Threshold Saturation for Spatially Coupled Turbo-like Codes over the Binary Erasure Channel,"In this paper we prove threshold saturation for spatially coupled turbo codes
+(SC-TCs) and braided convolutional codes (BCCs) over the binary erasure
+channel. We introduce a compact graph representation for the ensembles of SC-TC
+and BCC codes which simplifies their description and the analysis of the
+message passing decoding. We demonstrate that by few assumptions in the
+ensembles of these codes, it is possible to rewrite their vector recursions in
+a form which places these ensembles under the category of scalar admissible
+systems. This allows us to define potential functions and prove threshold
+saturation using the proof technique introduced by Yedla et al..",1508.02196v1
+2015-09-04,Saturation of the f-mode instability in neutron stars: I. Theoretical framework,"The basic formulation describing quadratic mode coupling in rotating
+Newtonian stars is presented, focusing on polar modes. Due to the
+Chandrasekhar-Friedman-Schutz mechanism, the f-mode (fundamental oscillation)
+is driven unstable by the emission of gravitational waves. If the star falls
+inside the so-called instability window, the mode's amplitude grows
+exponentially, until it is halted by nonlinear effects. Quadratic perturbations
+form three-mode networks inside the star, which evolve as coupled oscillators,
+exchanging energy. Coupling of the unstable f-mode to other (stable) modes can
+lead to a parametric resonance and the subsequent saturation of its amplitude,
+thus suppressing the instability. The saturation point determines the amplitude
+of the gravitational-wave signal obtained from an individual source, as well as
+the evolutionary path of the latter inside the instability window.",1509.01453v2
+2015-09-11,Breakdown of compensation and persistence of non-saturating magnetoresistance in WTe2 thin flakes,"We present a detailed study of magnetoresistance \r{ho}xx(H), Hall effect
+\r{ho}xy(H), and electrolyte gating effect in thin (<100 nm) exfoliated
+crystals of WTe2. We observe quantum oscillations in H of both \r{ho}xx(H) and
+\r{ho}xy(H), and identify four oscillation frequencies consistent with previous
+reports in thick crystals. \r{ho}xy(H) is linear in H at low H consistent with
+near-perfect electron-hole compensation, however becomes nonlinear and changes
+sign with increasing H, implying a breakdown of compensation. A field-dependent
+ratio of carrier concentrations p/n can consistently explain \r{ho}xx(H) and
+\r{ho}xy(H) within a two-fluid model. We also employ an electrolytic gate to
+highly electron-dope WTe2 with Li. The non-saturating \r{ho}xx(H) persists to H
+= 14 T with magnetoresistance ratio exceeding 2 x 104 %, even with significant
+deviation from perfect electron-hole compensation (p/n = 0.84), where the
+two-fluid model predicts a saturating \r{ho}xx(H). Our results suggest
+electron-hole compensation is not the mechanism for extremely large
+magnetoresistance in WTe2, other alternative explanations need to be
+considered.",1509.03623v1
+2015-10-07,An IMPES scheme for a two-phase flow in heterogeneous porous media using a structured grid,"We develop a numerical scheme for a two-phase immiscible flow in
+heterogeneous porous media using a structured grid finite element method, which
+have been successfully used for the computation of various physical
+applications involving elliptic equations \cite{li2003new, li2004immersed,
+chang2011discontinuous, chou2010optimal, kwak2010analysis}. The proposed method
+is based on the implicit pressure-explicit saturation procedure. To solve the
+pressure equation, we use an IFEM based on the Rannacher-Turek
+\cite{rannacher1992simple} nonconforming space, which is a modification of the
+work in \cite{kwak2010analysis} where `broken' $P_1$ nonconforming element of
+Crouzeix-Raviart \cite{crouzeix1973conforming} was developed.
+  For the Darcy velocity, we apply the mixed finite volume method studied in
+\cite{chou2003mixed, kwak2010analysis} on the basis of immersed finite element
+method (IFEM). In this way, the Darcy velocity of the flow can be computed
+cheaply (locally) after we solve the pressure equation. The computed Darcy
+velocity is used to solve the saturation equation explicitly. Thus the whole
+procedure can be implemented in an efficient way using a structured grid which
+is independent of the underlying heterogeneous porous media. Numerical results
+show that our method exhibits optimal order convergence rates for the pressure
+and velocity variables, and suboptimal rate for saturation.",1510.01839v1
+2015-10-21,Exploring Complex-Langevin Methods for Finite-Density QCD,"QCD at non-zero chemical potential ($\mu$) for quark number has a complex
+fermion determinant and thus standard simulation methods for lattice QCD cannot
+be applied. We therefore simulate this theory using the Complex-Langevin
+algorithm with Gauge Cooling in addition to adaptive methods, to prevent
+runaway behaviour. Simulations are performed at zero temperature on a $12^4$
+lattice with 2 quarks which are light enough that $m_N/3$ is significantly
+larger than $m_\pi/2$. Preliminary results are qualitatively as expected. The
+quark-number density is close to zero for $\mu < m_N/3$, beyond which it
+increases, eventually reaching its saturation value of $3$ for $\mu$
+sufficiently large. The chiral condensate decreases as $\mu$ is increased
+approaching zero at saturation, while the plaquette increases towards its
+quenched value. We have yet to observe the transition to nuclear matter at $\mu
+\approx m_N/3$, presumably because the runs for $\mu$ between $m_N/3$ and
+saturation have yet to equilibrate.",1510.06367v1
+2015-11-18,Robust self-trapping of vortex beams in a saturable optical medium,"We report the first observation of robust self-trapping of vortex beams
+propagating in a uniform condensed medium featuring local saturable
+self-focusing nonlinearity. Optical vortices with topological charge m=1, that
+remain self-trapped over ~ 5 Rayleigh lengths, are excited in carbon disulfide
+using a helical light beam at 532 nm and intensities from 8 to 10 GW/cm^2. At
+larger intensities, the vortex beams lose their stability, spontaneously
+breaking into two fragments. Numerical simulations based on the nonlinear
+Schr\""odinger equation including the three-photon absorption and nonpolynomial
+saturation of the refractive nonlinearity demonstrate close agreement with the
+experimental findings.",1511.06009v2
+2015-12-05,Avalanche effect and gain saturation in high harmonic generation,"Optical amplifiers in all ranges of the electromagnetic spectrum exhibit two
+essential characteristics: i) the input signal during the propagation in the
+medium is multiplied by the avalanche effect of the stimulated emission to
+produce exponential growth and ii) the amplification saturates at increasing
+input signal. We demonstrate that the strong-field theory in the frame of high
+harmonic generation fully supports the appearance of both the avalanche and
+saturation effects in the amplification of extreme ultraviolet attosecond pulse
+trains. We confirm that the amplification takes place only if the seed pulses
+are perfectly synchronized with the driving strong field in the amplifier. We
+performed an experimental study and subsequent model calculation on He gas
+driven by intense 30-fs-long laser pulses, which was seeded with an attosecond
+pulse train at 110 eV generated in a separated Ne gas jet. The comparison of
+the performed calculations with the measurements clearly demonstrates that the
+pumped He gas medium acted as an amplifier of the extreme ultraviolet pulse
+train.",1512.01664v1
+2015-12-06,Rates Achievable on a Fiber-Optical Split-Step Fourier Channel,"A lower bound on the capacity of the split-step Fourier channel is derived.
+The channel under study is a concatenation of smaller segments, within which
+three operations are performed on the signal, namely, nonlinearity, linearity,
+and noise addition. Simulation results indicate that for a fixed number of
+segments, our lower bound saturates in the high-power regime and that the
+larger the number of segments is, the higher is the saturation point. We also
+obtain an alternative lower bound, which is less tight but has a simple
+closed-form expression. This bound allows us to conclude that the saturation
+point grows unbounded with the number of segments. Specifically, it grows as
+$c+(1/2)\log(K)$, where $K$ is the number of segments and $c$ is a constant.
+The connection between our channel model and the nonlinear Schr\""odinger
+equation is discussed.",1512.01843v4
+2015-12-11,Saturation of number variance in embedded random matrix ensembles,"We study fluctuation properties of embedded random matrix ensembles of
+non-interacting particles. For ensemble of two non-interacting particle
+systems, we find that unlike the spectra of classical random matrices,
+correlation functions are non-stationary. In the locally stationary region of
+spectra, we study the number variance and the spacing distributions. The
+spacing distributions follow the Poisson statistics which is a key behavior of
+uncorrelated spectra. The number variance varies linearly as in the Poisson
+case for short correlation lengths but a kind of regularization occurs for
+large correlation lengths, and the number variance approaches saturation
+values. These results are known in the study of integrable systems but are
+being demonstrated for the first time in random matrix theory. We conjecture
+that the interacting particle cases, which exhibit the characteristics of
+classical random matrices for short correlation lengths, will also show
+saturation effects for large correlation lengths.",1512.03593v1
+2015-12-16,Pinning down QCD-matter shear viscosity in A+A collisions via EbyE fluctuations using pQCD + saturation + hydrodynamics,"We compute the initial energy densities produced in ultrarelativistic
+heavy-ion collisions from NLO perturbative QCD using a saturation conjecture to
+control soft particle production, and describe the subsequent space-time
+evolution of the system with hydrodynamics, event by event. The resulting
+centrality dependence of the low-$p_T$ observables from this pQCD + saturation
++ hydro (""EKRT"") framework are then compared simultaneously to the LHC and RHIC
+measurements. With such an analysis we can test the initial state calculation,
+and constrain the temperature dependence of the shear viscosity-to-entropy
+ratio $\eta/s$ of QCD matter. Using these constraints from the current RHIC and
+LHC measurements we then predict the charged hadron multiplicities and flow
+coefficients for the 5.023 TeV Pb+Pb collisions.",1512.05132v1
+2016-01-02,Holographic thermalization from non relativistic branes,"In this paper, based on the fundamental principles of Gauge/gravity duality
+and considering a \textit{global quench}, we probe the physics of
+thermalization for a special class of strongly coupled non relativistic QFTs by
+computing the entanglement entropy of the plasma. The isometry group of such
+QFTs is comprised of the generators of the Schr\""odinger algebra which could be
+precisely realized as an isometry group of the killing generators of an
+asymptotically Schr\""odinger $ Dp $ brane space time. In our analysis, we note
+that during the pre local stages of the thermal equilibrium the entanglement
+entropy has a faster growth in time compared to its relativistic cousin.
+However, it shows a linear growth during the post local stages of thermal
+equilibrium where the so called tsunami velocity associated with the linear
+growth of the entanglement entropy saturates to that of its value corresponding
+to the relativistic scenario. Finally, we explore the saturation region and it
+turns out that one must constraint certain parameters of the theory in a
+specific way in order to have a discontinuous transitions at the point of
+saturation.",1601.00136v2
+2016-01-21,Saturation of ion irradiation effects in Cr2AlC,"Cr2AlC materials were irradiated with 7 MeV Xe26+ ions and 500 keV He2+ ions
+at room temperature. A structural transition with an increased c lattice
+parameter and a decreased a lattice parameter occurs after irradiation to doses
+above 1 dpa. Nevertheless, the modified structure is stable up to the dose of
+5.2 dpa without obvious lattice disorder. The three samples irradiated to doses
+above 1 dpa have comparable lattice parameters and hardness values, suggesting
+a saturation of irradiation effects in Cr2AlC. The structural transition and
+irradiation effects saturation are ascribed to irradiation-induced antisite
+defects (CrAl and AlCr) and C interstitials, which is supported by the
+calculations of the formation energies of various defects in Cr2AlC. The
+irradiation-induced antisite defects and C interstitials may be critical to
+understand the excellent resistance to irradiation-induced amorphization of MAX
+phases.",1601.05514v1
+2016-02-24,Optical switching and bistability in a four-level atomic systems,"We explore the coherent control of nonlinear absorption of intense laser
+fields in four-level atomic systems. For instance, in a four-level ladder
+system, a coupling field creates electromagnetically induced transparency (EIT)
+with Aulter-Townes doublet for the probe field while the control field is
+absent. A large absorption peak appears at resonance as the control field is
+switched on. We show how such a large absorption leads to optical switching.
+Further, this large absorption gets diminished and a transparency window
+appears due to the saturation effects as the strength of the probe field is
+increased. We further demonstrate that the threshold of the optical bistability
+can be modified by suitable choices of the coupling and the control fields. In
+a four-level Y-type configuration, the effect of the control field on saturable
+absorption (SA) and reverse saturable absorption (RSA) is highlighted in the
+context of nonlinear absorption of the probe field. We achieve RSA and SA in a
+simple atomic system just by applying a control field.",1602.07596v3
+2016-03-22,Locally Conservative Continuous Galerkin FEM for Pressure Equation in Two-Phase Flow Model in Subsurfaces,"A typical two-phase model for subsurface flow couples the Darcy equation for
+pressure and a transport equation for saturation in a nonlinear manner. In this
+paper, we study a combined method consisting of continuous Galerkin finite
+element methods (CGFEMs) followed by a post-processing technique for Darcy
+equation and finite volume method (FVM) with upwind schemes for the saturation
+transport equation, in which the coupled nonlinear problem is solved in the
+framework of operator decomposition. The postprocessing technique is applied to
+CGFEM solutions to obtain locally conservative fluxes which ensures accuracy
+and robustness of the FVM solver for the saturation transport equation. We
+applied both upwind scheme and upwind scheme with slope limiter for FVM on
+triangular meshes in order to eliminate the non-physical oscillations. Various
+numerical examples are presented to demonstrate the performance of the overall
+methodology.",1603.06998v1
+2016-04-06,Constraining the supersaturation density equation of state from core-collapse supernova simulations - Excluded volume extension of the baryons,"In this article the role of the supersaturation density equation of state
+(EOS) is explored in simulations of failed core-collapse supernova explosions.
+Therefore the nuclear EOS is extended via a one-parameter excluded volume
+description for baryons, taking into account their finite and increasing volume
+with increasing density in excess of saturation density. Parameters are
+selected such that the resulting supernova EOS represent extreme cases, with
+high pressure variations at supersaturation density which feature extreme stiff
+and soft EOS variants of the reference case, i.e. without excluded volume
+corrections. Unlike in the interior of neutron stars with central densities in
+excess of several times saturation density, central densities of core-collapse
+supernovae reach only slightly above saturation density. Hence, the impact of
+the supersaturation density EOS on the supernova dynamics as well as the
+neutrino signal is found to be negligible. It is mainly determined from the
+low- and intermediate-density domain, which is left unmodified within this
+generalized excluded volume approach.",1604.01629v1
+2016-04-07,Stability of Fluid Queuing Systems with Parallel Servers and Stochastic Capacities,"This note introduces a piecewise-deterministic queueing (PDQ) model to study
+the stability of traffic queues in parallel-link transportation systems facing
+stochastic capacity fluctuations. The saturation rate (capacity) of the PDQ
+model switches between a finite set of modes according to a Markov chain, and
+link inflows are controlled by a state-feedback policy. A PDQ system is stable
+only if a lower bound on the time-average link inflows does not exceed the
+corresponding time-average saturation rate. Furthermore, a PDQ system is stable
+if the following two conditions hold: the nominal mode's saturation rate is
+high enough that all queues vanish in this mode, and a bilinear matrix
+inequality (BMI) involving an underestimate of the discharge rates of the PDQ
+in individual modes is feasible. The stability conditions can be strengthened
+for two-mode PDQs. These results can be used for design of routing policies
+that guarantee stability of traffic queues under stochastic capacity
+fluctuations.",1604.02008v6
+2016-04-09,Relaxation and Purification for Nonconvex Variational Problems in Dual Banach Spaces: The Minimization Principle in Saturated Measure Spaces,"We formulate bang-bang, purification, and minimization principles in dual
+Banach spaces with Gelfand integrals and provide a complete characterization of
+the saturation property of finite measure spaces. We also present a new
+application of the relaxation technique to large economies with
+infinite-dimensional commodity spaces, where the space of agents is modeled as
+a finite measure space. We propose a ""relaxation"" of large economies, which is
+regarded as a reasonable convexification of original economies. Under the
+saturation hypothesis, the relaxation and purification techniques enable us to
+prove the existence of Pareto optimal allocations without convexity
+assumptions.",1604.02514v3
+2016-06-19,On the Inheritance of Orbifold Substructures,"In a previous article, we defined a very flexible notion of suborbifold and
+characterized those suborbifolds which can arise as the images of orbifold
+embeddings. In particular, suborbifolds are images of orbifold embeddings
+precisely when they are saturated and split. This article addresses the problem
+of orbifold structure inheritance for three orbifolds
+$\mathcal{Q}\subset\mathcal{P}\subset\mathcal{O}$. We identify an appealing but
+ultimately inadequate notion of an inherited canonical orbifold substructure.
+In particular, we give a concrete example where the orbifold structure of
+$\mathcal{Q}$ is canonically inherited from $\mathcal{P}$, and the orbifold
+structure of $\mathcal{P}$ is canonically inherited from $\mathcal{O}$, but the
+orbifold structure of $\mathcal{Q}$ is not canonically inherited from
+$\mathcal{O}$. On the other hand, it is easy to see that when $\mathcal{Q}$ is
+embedded in $\mathcal{P}$, and $\mathcal{P}$ is embedded in $\mathcal{O}$, all
+of the canonical inherited orbifold substructures will agree. We also
+investigate the property of saturation in this context, and give an example of
+a suborbifold with the canonical orbifold substructure that is not saturated.",1606.05902v1
+2016-07-03,CGC/saturation approach for high energy soft interactions: `soft' Pomeron structure and $v_{n}$ in hadron and nucleus collisions from Bose-Einstein correlation,"In the framework of our model of soft interactions at high energy based on
+CGC/saturation approach,we show that Bose-Einstein correlations of identical
+gluons lead to large values of $v_n$. We demonstrate how three dimensional
+scales of high energy interactions: hadron radius, typical size of the wave
+function in diffractive production of small masses (size of the constituent
+quark), and the saturation momentum, influence the values of BE correlations,
+and in particular, the values of $v_n$. Our calculation shows that the
+structure of the `dressed' Pomeron leads to values of $v_n$ which are close to
+experimental values for proton-proton scattering, 20\% smaller than the
+observed values for proton-lead collisions, and close to lead-lead collisions
+for 0-10\% centrality. Bearing this result in mind, we conclude that it is
+premature to consider, that the appearance of long range rapidity azimuthal
+correlations are due only to the hydrodynamical behaviour of the quark-gluon
+plasma.",1607.00594v3
+2016-07-22,Collisionality scaling of the electron heat flux in ETG turbulence,"In electrostatic simulations of MAST plasma at electron-gyroradius scales,
+using the local flux-tube gyrokinetic code GS2 with adiabatic ions, we find
+that the long-time saturated electron heat flux (the level most relevant to
+energy transport) decreases as the electron collisionality decreases. At early
+simulation times, the heat flux ""quasi-saturates"" without any strong dependence
+on collisionality, and with the turbulence dominated by streamer-like radially
+elongated structures. However, the zonal fluctuation component continues to
+grow slowly until much later times, eventually leading to a new saturated state
+dominated by zonal modes and with the heat flux proportional to the collision
+rate, in approximate agreement with the experimentally observed collisionality
+scaling of the energy confinement in MAST. We outline an explanation of this
+effect based on a model of ETG turbulence dominated by zonal-nonzonal
+interactions and on an analytically derived scaling of the zonal-mode damping
+rate with the electron-ion collisionality. Improved energy confinement with
+decreasing collisionality is favourable towards the performance of future,
+hotter devices.",1607.06752v2
+2016-07-28,Cavity polaritons with Rydberg blockade and long-range interactions,"We study interactions between polaritons, arising when photons strongly
+couple to collective excitations in an array of two-level atoms trapped in an
+optical lattice inside a cavity. We consider two types of interactions between
+atoms: Dipolar forces and atomic saturability, which ranges from hard-core
+repulsion to Rydberg blockade. We show that, in spite of the underlying
+repulsion in the subsystem of atomic excitations, saturability induces a
+broadband bunching of photons for two-polariton scattering states. We interpret
+this bunching as a result of interference, and trace it back to the mismatch of
+the quantization volumes for atomic excitations and photons. We examine also
+bound bipolaritonic states: These include states created by dipolar forces, as
+well as a gap bipolariton, which forms solely due to saturability effects in
+the atomic transition. Both types of bound states exhibit strong bunching in
+the photonic component. We discuss the dependence of bunching on experimentally
+relevant parameters.",1607.08323v1
+2016-08-22,The virial theorem and ground state energy estimate of nonlinear Schrödinger equations in $\mathbb{R}^2$ with square root and saturable nonlinearities in nonlinear optics,"The virial theorem is a nice property for the linear Schrodinger equation in
+atomic and molecular physics as it gives an elegant ratio between the kinetic
+and potential energies and is useful in assessing the quality of numerically
+computed eigenvalues. If the governing equation is a nonlinear Schrodinger
+equation with power-law nonlinearity, then a similar ratio can be obtained but
+there seems no way of getting any eigenvalue estimate. It is surprising as far
+as we are concerned that when the nonlinearity is either square-root or
+saturable nonlinearity (not a power-law), one can develop a virial theorem and
+eigenvalue estimate of nonlinear Schrodinger (NLS) equations in R2 with
+square-root and saturable nonlinearity, respectively. Furthermore, we show here
+that the eigenvalue estimate can be used to obtain the 2nd order term (which is
+of order $ln\Gamma$) of the lower bound of the ground state energy as the
+coefficient $\Gamma$ of the nonlinear term tends to infinity.",1608.06102v1
+2016-09-20,Impact of the tidal p-g instability on the gravitational wave signal from coalescing binary neutron stars,"Recent studies suggest that coalescing neutron stars are subject to a fluid
+instability involving the nonlinear coupling of the tide to $p$-modes and
+$g$-modes. Its influence on the inspiral dynamics and thus the gravitational
+wave signal is, however, uncertain because we do not know precisely how the
+instability saturates. Here we construct a simple, physically motivated model
+of the saturation that allows us to explore the instability's impact as a
+function of the model parameters. We find that for plausible assumptions about
+the saturation, current gravitational wave detectors might miss $> 70\%$ of
+events if only point particle waveforms are used. Parameters such as the chirp
+mass, component masses, and luminosity distance might also be significantly
+biased. On the other hand, we find that relatively simple modifications to the
+point particle waveform can alleviate these problems and enhance the science
+that emerges from the detection of binary neutron stars.",1609.06362v2
+2016-10-03,Emergent eddy saturation from an energy constrained eddy parameterisation,"The large-scale features of the global ocean circulation and the sensitivity
+of these features with respect to forcing changes are critically dependent upon
+the influence of the mesoscale eddy field. One such feature, observed in
+numerical simulations whereby the mesoscale eddy field is at least partially
+resolved, is the phenomenon of eddy saturation, where the time-mean circumpolar
+transport of the Antarctic Circumpolar Current displays relative insensitivity
+to wind forcing changes. Coarse-resolution models employing the
+Gent--McWilliams parameterisation with a constant Gent--McWilliams coefficient
+seem unable to reproduce this phenomenon. In this article, an idealised model
+for a wind-forced, zonally symmetric flow in a channel is used to investigate
+the sensitivity of the circumpolar transport to changes in wind forcing under
+different eddy closures. It is shown that, when coupled to a simple
+parameterised eddy energy budget, the Gent--McWilliams coefficient of the form
+described in Marshall et al. (2012) [A framework for parameterizing eddy
+potential vorticity fluxes, J. Phys. Oceanogr., vol. 42, 539--557], which
+includes a linear eddy energy dependence, produces eddy saturation as an
+emergent property.",1610.00621v1
+2016-10-19,Coupling of Damped and Growing Modes in Unstable Shear Flow,"Analysis of the saturation of the Kelvin-Helmholtz (KH) instability is
+undertaken to determine the extent to which the conjugate linearly stable mode
+plays a role. For a piecewise-continuous mean flow profile with constant shear
+in a fixed layer, it is shown that the stable mode is nonlinearly excited,
+providing an injection-scale sink of the fluctuation energy similar to what has
+been found for gyroradius-scale drift-wave turbulence. Quantitative evaluation
+of the contribution of the stable mode to the energy balance at the onset of
+saturation shows that nonlinear energy transfer to the stable mode is as
+significant as energy transfer to small scales in balancing energy injected
+into the spectrum by the instability. The effect of the stable mode on momentum
+transport is quantified by expressing the Reynolds stress in terms of stable
+and unstable mode amplitudes at saturation, from which it is found that the
+stable mode can produce a sizable reduction in the momentum flux.",1610.06142v4
+2016-11-12,Saturating The Bekenstein-Hawking Entropy Bound With Initial Data Sets For Gravitational Collapse,"It is possible to find initial states for gravitational collapse whose
+entropy approximately saturates the Bekenstein-Hawking entropy of the final
+black hole. The prototypical example of such a state is that envisaged by Zurek
+and Thorne, and also by Susskind: for a black hole of mass $\sim M$ , a number
+$\sim M^2$ of quanta with energies of order $1/M$ are accreted on a timescale
+of order $\sim M^3$, an approximate time-reverse of Hawking evaporation. There
+is lore that all initial states which saturate the Bekenstein-Hawking entropy
+must involve a formation timescale of this order, $M^3$ , and not the much
+shorter dynamical timescale $M$ . Counterexamples to this lore have been found
+by Sorkin, Wald and Zhang, and also by Hsu and Reeb, in the form of
+semiclassical initial data sets. However the spacetimes that correspond to
+these counterexamples possess white holes in the past, as well as black holes
+in the future, which casts doubt on their physical relevance. We modify the
+counterexamples to eliminate the white holes, yielding formation timescales of
+order $M^2$ , and argue that the lore is unfounded.",1611.04044v3
+2016-11-15,Phase Jump Method for Efficiency Enhancement in Free-Electron Lasers,"The efficiency of a free-electron laser can be enhanced by sustaining the
+growth of the radiation power beyond the initial saturation. One notable method
+is undulator tapering, which involves the variation of the gap height and/or
+the period along the undulator. Another method is the introduction of phase
+jumps, using phase-shifting chicanes in the drift sections separating the
+undulator segments. In this article, we develop a physics model of this phase
+jump method, and verify it with numerical simulations. The model elucidates the
+energy extraction process in the longitudinal phase space. The main ingredient
+is the microbunch deceleration cycle, which enables the microbunched electron
+beam to decelerate and radiate coherently beyond the initial saturation. The
+ponderomotive bucket is stationary, and energy can even be extracted from
+electrons outside the bucket. The model addresses the selection criteria for
+the phase jump values, and the requirement on the undulator segment length. It
+also describes the mechanism of the final saturation. In addition, we discuss
+the similarities and differences between the phase jump method and undulator
+tapering, by comparing our phase jump model to the classic
+Kroll-Morton-Rosenbluth model.",1611.04925v1
+2016-12-02,Collective Phenomena in $pp$ and $ep$ Scattering,"Bjorken scaling violation in deep inelastic electron-proton scattering (DIS)
+is related to the rise of hadronic cross sections by using the additive quark
+model. Of special interest is the connection between saturation in the low-$x$
+behavior of the DIS structure functions (SF) and possible slow-down of the $pp$
+cross section rise due to saturation effects. We also identify saturation
+effects in the DIS SF with phase transition that can be described by the Van
+der Waals equation of state.",1612.00797v2
+2016-12-15,Reducing Nondeterministic Tree Automata by Adding Transitions,"We introduce saturation of nondeterministic tree automata, a technique that
+consists of adding new transitions to an automaton while preserving its
+language. We implemented our algorithm on minotaut - a module of the tree
+automata library libvata that reduces the size of automata by merging states
+and removing superfluous transitions - and we show how saturation can make
+subsequent merge and transition-removal operations more effective. Thus we
+obtain a Ptime algorithm that reduces the size of tree automata even more than
+before. Additionally, we explore how minotaut alone can play an important role
+when performing hard operations like complementation, allowing to both obtain
+smaller complement automata and lower computation times. We then show how
+saturation can extend this contribution even further. We tested our algorithms
+on a large collection of automata from applications of libvata in shape
+analysis, and on different classes of randomly generated automata.",1612.04981v1
+2016-12-21,Operator entanglement entropy of the time evolution operator in chaotic systems,"We study the growth of the operator entanglement entropy (EE) of the time
+evolution operator in chaotic, many-body localized and Floquet systems. In the
+random field Heisenberg model we find a universal power law growth of the
+operator EE at weak disorder, a logarithmic growth at strong disorder, and
+extensive saturation values in both cases. In a Floquet spin model, the
+saturation value after an initial linear growth is identical to the value of a
+random unitary operator (the Page value). We understand these properties by
+mapping the operator EE to a global quench problem evolved with a similar
+parent-Hamiltonian in an enlarged Hilbert space with the same chaotic, MBL and
+Floquet properties as the original Hamiltonian. The scaling and saturation
+properties reflect the spreading of the state EE of the corresponding time
+evolution. We conclude that the EE of the evolution operator should
+characterize the propagation of information in these systems.",1612.07327v2
+2017-01-16,Investigating the impact of the gluon saturation effects on the momentum transfer distributions for the exclusive vector meson photoproduction in hadronic collisions,"The exclusive vector meson production cross section is one of the most
+promising observables to probe the high energy regime of the QCD dynamics. In
+particular, the squared momentum transfer ($t$) distributions are an important
+source of information about the spatial distribution of the gluons in the
+hadron and about fluctuations of the color fields. In this paper we complement
+previous studies on exclusive vector meson photoproduction in hadronic
+collisions presenting a comprehensive analysis of the $t$ - spectrum measured
+in exclusive $\rho$, $\phi$ and $J/\Psi$ photoproduction in $pp$ and $PbPb$
+collisions at the LHC. We compute the differential cross sections taking into
+account gluon saturation effects and compare the predictions with those
+obtained in the linear regime of the QCD dynamics. Our results show that gluon
+saturation suppresses the magnitude of the cross sections and shifts the
+position of the dips towards smaller values of $t$.",1701.04340v1
+2017-01-18,Hysteretic behavior of electrical conductivity in packings of particles,"We address the problem of predicting saturation-dependent electrical
+conductivity {\sigma} in packings of spheres during drainage and imbibition.
+The effective-medium approximation (EMA) and the universal power law of
+percolation for {\sigma} are used, respectively, at higher and low water
+saturations to predict the conductivity, with the crossover between the two
+occurring at some intermediate saturation Swx. The main input to the theory is
+a single parameter that we estimate using the capillary pressure data. The
+predictions are compared with experimental, as well as numerical data for three
+distinct types of packings. The results for drainage in all the packings
+indicate that the universal power law of percolation is valid over the entire
+range of Sw. For imbibition, however, the universal power law crosses over to
+the EMA at Swx = 0.5. We also find that the effect of the pore-size
+distribution on the {\sigma}-Sw relation is minimal during both drainage and
+imbibition.",1701.05076v1
+2017-01-23,Saturated absorption competition microscopy,"We introduce the concept of saturated absorption competition (SAC) microscopy
+as a means of providing sub-diffraction spatial resolution in fluorescence
+imaging. Unlike the post-competition process between stimulated and spontaneous
+emission that is used in stimulated emission depletion (STED) microscopy, SAC
+microscopy breaks the diffraction limit by emphasizing a pre-competition
+process that occurs in the fluorescence absorption stage in a manner that
+shares similarities with ground-state depletion (GSD) microscopy. Moreover,
+unlike both STED and GSD microscopy, SAC microscopy offers a reduction in
+complexity and cost by utilizing only a single continuous-wave laser diode and
+an illumination intensity that is ~ 20x smaller than that used in STED. Our
+approach can be physically implemented in a confocal microscope by dividing the
+input laser source into a time-modulated primary excitation beam and a
+doughnut-shaped saturation beam, and subsequently employing a homodyne
+detection scheme to select the modulated fluorescence signal. Herein, we
+provide both a physico-chemical model of SAC and experimentally demonstrate by
+way of a proof-of-concept experiment a transverse spatial resolution of
+~lambda/6.",1701.06358v1
+2017-03-13,Josephson parametric converter saturation and higher order effects,"Microwave parametric amplifiers based on Josephson junctions have become a
+key component of many quantum information experiments. One key limitation which
+has not been well predicted by theory is the gain saturation behavior which
+determines its ability to process large amplitude signals. The typical
+explanation for this behavior in phase-preserving amplifiers based on
+three-wave mixing is pump depletion, in which the consumption of pump photons
+to produce amplification results in a reduction in gain. However, in this work
+we present experimental data and theoretical calculations showing that the
+fourth-order Kerr nonlinearities inherent in the Josephson junctions are the
+dominant factor in the Josephson Parametric Converter (JPC). The Kerr-based
+theory has the unusual property of causing saturation to both lower and higher
+gains, depending on bias conditions. This work presents a new methodology for
+optimizing device performance in the presence of Kerr nonlinearities while
+retaining device tunability, and points to the necessity of controlling
+higher-order Hamiltonian terms to make further improvements in parametric
+devices.",1703.04425v2
+2017-03-14,A Quasi-Linear Time Algorithm Deciding Whether Weak Büchi Automata Reading Vectors of Reals Recognize Saturated Languages,"This work considers weak deterministic B\""uchi automata reading encodings of
+non-negative $d$-vectors of reals in a fixed base. A saturated language is a
+language which contains all encoding of elements belonging to a set of
+$d$-vectors of reals. A Real Vector Automaton is an automaton which recognizes
+a saturated language. It is explained how to decide in quasi-linear time
+whether a minimal weak deterministic B\""uchi automaton is a Real Vector
+Automaton. The problem is solved both for the two standard encodings of vectors
+of numbers: the sequential encoding and the parallel encoding. This algorithm
+runs in linear time for minimal weak B\""uchi automata accepting set of reals.
+Finally, the same problem is also solved for parallel encoding of automata
+reading vectors of relative reals.",1703.04834v1
+2017-03-24,Definably compact groups definable in real closed fields. I,"We study definably compact definably connected groups definable in a
+sufficiently saturated real closed field $R$. We introduce the notion of
+group-generic point for $\bigvee$-definable groups and show the existence of
+group-generic points for definably compact groups definable in a sufficiently
+saturated o-minimal expansion of a real closed field. We use this notion along
+with some properties of generic sets to prove that for every definably compact
+definably connected group $G$ definable in $R$ there are a connected
+$R$-algebraic group $H$, a definable injective map $\phi$ from a generic
+definable neighborhood of the identity of $G$ into the group $H\left(R\right)$
+of $R$-points of $H$ such that $\phi$ acts as a group homomorphism inside its
+domain. This result is used in [2] to prove that the o-minimal universal
+covering group of an abelian connected definably compact group definable in a
+sufficiently saturated real closed field $R$ is, up to locally definable
+isomorphisms, an open connected locally definable subgroup of the o-minimal
+universal covering group of the $R$-points of some $R$-algebraic group.",1703.08606v2
+2017-05-19,Topological dynamics and excitations in lasers and condensates with saturable gain or loss,"We classify symmetry-protected and symmetry-breaking dynamical solutions for
+nonlinear saturable bosonic systems that display a non-hermitian
+charge-conjugation symmetry, as realized in a series of recent groundbreaking
+experiments with lasers and exciton polaritons. In particular, we show that
+these systems support stable symmetry-protected modes that mirror the concept
+of zero-modes in topological quantum systems, as well as symmetry-protected
+power-oscillations with no counterpart in the linear case. In analogy to
+topological phases in linear systems, the number and nature of
+symmetry-protected solutions can change. The spectral degeneracies signalling
+phase transitions in linear counterparts extend to bifurcations in the
+nonlinear context. As bifurcations relate to qualitative changes in the linear
+stability against changes of the initial conditions, the symmetry-protected
+solutions and phase transitions can also be characterized by topological
+excitations, which set them apart from symmetry-breaking solutions. The
+stipulated symmetry appears naturally when one introduces nonlinear gain or
+loss into spectrally symmetric bosonic systems, as we illustrate for
+one-dimensional topological laser arrays with saturable gain and
+two-dimensional flat-band polariton condensates with density-dependent loss.",1705.06895v2
+2017-06-22,Intertial wave turbulence driven by elliptical instability,"The combination of elliptical deformation of streamlines and vorticity can
+lead to the destabilisation of any rotating flow via the elliptical
+instability. Such a mechanism has been invoked as a possible source of
+turbulence in planetary cores subject to tidal deformations. The saturation of
+the elliptical instability has been shown to generate turbulence composed of
+non-linearly interacting waves and strong columnar vortices with varying
+respective amplitudes, depending on the control parameters and geometry. In
+this paper, we present a suite of numerical simulations to investigate the
+saturation and the transition from vortex-dominated to wave-dominated regimes.
+This is achieved by simulating the growth and saturation of the elliptical
+instability in an idealised triply periodic domain, adding a frictional damping
+to the geostrophic component only, to mimic its interaction with boundaries. We
+reproduce several experimental observations within one idealised local model
+and complement them by reaching more extreme flow parameters. In particular, a
+wave-dominated regime that exhibits many signatures of inertial wave turbulence
+is characterised for the first time. This regime is expected in planetary
+interiors.",1706.07378v1
+2017-07-21,Solitary waves in nonlocal NLS with dispersion averaged saturated nonlinearities,"A nonlinear Schr\""odinger equation (NLS) with dispersion averaged
+nonlinearity of saturated type is considered. Such a nonlocal NLS is of
+integro-differential type and it arises naturally in modeling fiber-optics
+communication systems with periodically varying dispersion profile (dispersion
+management). The associated constrained variational principle is shown to
+posses a ground state solution by constructing a convergent minimizing sequence
+through the application of a method similar to the classical concentration
+compactness principle of Lions. One of the obstacles in applying this
+variational approach is that a saturated nonlocal nonlinearity does not satisfy
+uniformly the so-called strict sub-additivity condition. This is overcome by
+applying a special version of Ekeland's variational principle.",1707.06944v1
+2017-08-31,Online Feedback Control for Input-Saturated Robotic Systems on Lie Groups,"In this paper, we propose an approach to designing online feedback
+controllers for input-saturated robotic systems evolving on Lie groups by
+extending the recently developed Sequential Action Control (SAC). In contrast
+to existing feedback controllers, our approach poses the nonconvex constrained
+nonlinear optimization problem as the tracking of a desired negative mode
+insertion gradient on the configuration space of a Lie group. This results in a
+closed-form feedback control law even with input saturation and thus is well
+suited for online application. In extending SAC to Lie groups, the associated
+mode insertion gradient is derived and the switching time optimization on Lie
+groups is studied. We demonstrate the efficacy and scalability of our approach
+in the 2D kinematic car on SE(2) and the 3D quadrotor on SE(3). We also
+implement iLQG on a quadrator model and compare to SAC, demonstrating that SAC
+is both faster to compute and has a larger basin of attraction.",1709.00376v1
+2017-09-04,Consensus of second order multi-agents with actuator saturation and asynchronous time-delays,"This article presents the consensus of a saturated second order multi-agent
+system with non-switching dynamics that can be represented by a directed graph.
+The system is affected by data processing (input delay) and communication
+time-delays that are assumed to be asynchronous. The agents have saturation
+nonlinearities, each of them is approximated into separate linear and nonlinear
+elements. Nonlinear elements are represented by describing functions.
+Describing functions and stability of linear elements are used to estimate the
+existence of limit cycles in the system with multiple control laws. Stability
+analysis of the linear element is performed using Lyapunov-Krasovskii functions
+and frequency domain analysis. A comparison of pros and cons of both the
+analyses with respect to time-delay ranges, applicability and computation
+complexity is presented. Simulation and corresponding hardware implementation
+results are demonstrated to support theoretical results.",1709.00951v3
+2017-09-04,A Discrete Packing Model of Granular Material Confined in A Vertical Column,"The transmission rules of interparticle forces between granular particles
+were analyzed, and a discrete packing model was proposed to calculate the
+static pressure at the bottom of granular material confined in a vertical
+column. The mechanical analysis and numerical simulation results indicate that
+the silo effect is caused by the frictional contacts between border particles
+and inner walls, the static pressure at the bottom depends on the external load
+initially, and then tends to a saturation pressure (Pn) in an exponential form.
+The saturation pressure (Pn) is positive linear related to the container radius
+(R) with the same granular matter and stacking manner. The saturation pressure
+(Pn) is directly proportional to the particle size (ra), and the increasing or
+decreasing characteristic depends on the frictional property of inner walls,
+the friction and stacking angle of grains. At last, the predictions of the
+aforementioned model are compared with the experimental results from the
+literature, and good agreement is achieved.",1709.01001v2
+2017-09-18,Saturation of energetic-particle-driven geodesic acoustic modes due to wave-particle nonlinearity,"The nonlinear dynamics of energetic-particle (EP) driven geodesic acoustic
+modes (EGAM) is investigated here. A numerical analysis with the global
+gyrokinetic particle-in-cell code ORB5 is performed, and the results are
+interpreted with the analytical theory, in close comparison with the theory of
+the beam-plasma instability. Only axisymmetric modes are considered, with a
+nonlinear dynamics determined by wave-particle interaction. Quadratic scalings
+of the saturated electric field with respect to the linear growth rate are
+found for the case of interest. The EP bounce frequency is calculated as a
+function of the EGAM frequency, and shown not to depend on the value of the
+bulk temperature. Near the saturation, we observe a transition from adiabatic
+to non-adiabatic dynamics, i.e., the frequency chirping rate becomes comparable
+to the resonant EP bounce frequency. The numerical analysis is performed here
+with electrostatic simulations with circular flux surfaces, and kinetic effects
+of the electrons are neglected.",1709.05998v1
+2017-10-01,"Cumulant Expansion in Gluon Saturation, and Five and Six-Gluon Azimuthal Correlations","Correlations between the momenta of the final state hadrons measured in
+proton or nucleus collisions contain information that sheds light on the
+initial conditions and evolutionary dynamics of the collision system. These
+correlation measurements have revealed the long-range rapidity correlations in
+p-p and p-Pb systems, and they have also made it possible to extract the
+elliptic flow coefficient from hadron correlation measurements. In this work,
+we calculate five- and six-gluon correlation functions in the framework of
+saturation physics by using superdiagrams. We also derive the cumulant
+expansion of the gluon correlators that is valid in the gluon saturation limit.
+We show that the cumulant expansion of the gluon correlators that is used for
+counting the number of diagrams to be calculated does not follow the standard
+cumulant expansion. We also explain how these findings can be used in obtaining
+experimentally relevant observables such as flow coefficients calculated from
+correlations as well as ratios of the correlation functions of different
+orders.",1710.00425v2
+2017-11-02,Isospin Dependence of the EMC effect and Short range Correlations,"Recent studies have shown that the per-nucleon number of Short-Range
+Correlated (SRC) pairs in nuclei and the strength of the EMC effect are
+linearly correlated, increasing from light nuclei up to iron and then
+saturating. This paper shows that the per-proton number of SRC pairs and the
+strength of the EMC effect are linearly correlated and increase from light to
+heavy asymmetric neutron-rich nuclei without saturation. These quantities,
+calculated per neutron, are also linearly related, but saturate (have constant
+value) remarkably early, starting with 12C. We propose that the observed
+phenomenological relationships indicate an isospin dependence of the EMC effect
+which is associated with the dominance of SRCs by neutron-proton pairs from 3He
+to heavy asymmetric neutron-rich nuclei.",1711.00960v2
+2017-11-07,Variations of petrophysical properties and spectral induced polarization in response to drainage and imbibition: a study on a correlated random tube network,"We implement a procedure to simulate the drainage and imbibition in random,
+two-dimensional, square networks. We compute the resistivity index, the
+relative permeability, and the characteristic lengths of a correlated network
+at various saturation states, under the assumption that the surface
+conductivity can be neglected. These parameters exhibit a hysteretic behaviour.
+Then, we calculate the Spectral Induced Polarization (SIP) response of the
+medium, under the assumption that the electrical impedance of each tube follows
+a local Warburg conductivity model, with identical DC conductivity and
+chargeability for all the tubes. We evidence that the shape of the SIP spectra
+depends on the saturation state. The analysis of the evolution of the
+macroscopic Cole-Cole parameters of the spectra in function of the saturation
+also behaves hysteretically, except for the Cole-Cole exponent. We also observe
+a power-law relationship between the macroscopic DC conductivity and time
+constant and the relative permeability. We also show that the frequency peak of
+the phase spectra is directly related to the characteristic length and to the
+relative permeability, underlining the potential interest of SIP measurements
+for the estimation of the permeability of unsaturated media.",1711.02740v1
+2017-11-17,A simple hysteretic constitutive model for unsaturated flow,"In this paper we present a constitutive model to describe unsaturated flow
+that considers the hysteresis phenomena. This constitutive model provides
+simple mathematical expressions for both saturation and hydraulic conductivity
+curves, and a relationship between permeability and porosity. The model is
+based on the assumption that the porous media can be represented by a bundle of
+capillary tubes with throats or ""ink-bottles"" and a fractal pore size
+distribution. Under these hypotheses, hysteretic curves are obtained for
+saturation and relative hydraulic conductivity in terms of pressure head.
+However, a non-hysteretic relationship is obtained when relative hydraulic
+conductivity is expressed as a function of saturation. The proposed
+relationship between permeability and porosity is similar to the well-known
+Kozeny-Carman equation but depends on the fractal dimension. The performance of
+the constitutive model is tested against different sets of experimental data
+and previous models. In all of the cases the proposed expressions fit fairly
+well the experimental data and predicts values of permeability and hydraulic
+conductivity better than others models.",1711.06726v1
+2017-11-24,Role of the pair potential for the saturation of generalized Pauli constraints,"The dependence of the (quasi-)saturation of the generalized Pauli constraints
+on the pair potential is studied for ground states of few-fermion systems. For
+this, we consider spinless fermions in one dimension which are harmonically
+confined and interact by pair potentials of the form $|x_i-x_j|^s$ with $-1
+\leq s\leq 5$. We use the Density Matrix Renormalization Group approach and
+large orbital basis to achieve the convergence on more than ten digits of both
+the variational energy and the natural occupation numbers. Our results confirm
+that the conflict between energy minimization and fermionic exchange symmetry
+results in a universal and non-trivial quasi-saturation of the generalized
+Pauli constraints (\emph{quasipinning}), implying tremendous structural
+simplifications of the fermionic ground state for all $s$. Those numerically
+exact results are complemented by an analytical study based on a
+self-consistent perturbation theory which we develop for this purpose. The
+respective results for the weak coupling regime eventually elucidate the
+singular behaviour found for the specific values $s=2,4,\ldots$, resulting in
+an extremely strong quasipinning.",1711.09099v2
+2017-12-27,A refinement of the Robertson-Schrödinger uncertainty principle and a Hirschman-Shannon inequality for Wigner distributions,"We propose a refinement of the Robertson-Schrodinger uncertainty principle
+(RSUP) using Wigner distributions. This new principle is stronger than the
+RSUP. In particular, and unlike the RSUP, which can be saturated by many phase
+space functions, the refined RSUP can be saturated by pure Gaussian Wigner
+functions only. Moreover, the new principle is technically as simple as the
+standard RSUP. In addition, it makes a direct connection with modern harmonic
+analysis, since it involves the Wigner transform and its symplectic Fourier
+transform, which is the radar ambiguity function. As a by-product of the
+refined RSUP, we derive inequalities involving the entropy and the covariance
+matrix of Wigner distributions. These inequalities refine the Shanon and the
+Hirschman inequalities for the Wigner distribution of a mixed quantum state
+$\rho$. We prove sharp estimates which critically depend on the purity of
+$\rho$ and which are saturated in the Gaussian case.",1712.09475v1
+2018-01-16,Relating unsaturated electrical and hydraulic conductivity of cement-based materials,"Unsaturated hydraulic ($K$) and electrical ($\sigma_b$) conductivity are
+often considered durability indicators of cement-based materials. However, $K$
+is difficult to measure experimentally. This is due to the large pressure
+requirements at low degrees of saturation resulting from the fine pore-size
+distribution of cement-based materials. As a result, the commonly-used
+analytical models, requiring calibration of $K$ from experimental data, are
+often inaccurate at low degrees of saturation. On the other hand, measuring
+$\sigma_b$ is rather straight forward. Descriptions of the relationship between
+$\sigma_b$ and $K$ may therefore be particularly valuable when $K$ is required.
+In this work, we use experimental data from previous works to determine the
+feasibility of models employing a van Genuchten-Mualem based framework to
+predict $K$ and $\sigma_b$ -- expressions for diffusivity $D$ are also
+provided. We then develop analytical expressions relating $K$ and $\sigma_b$
+using these models. It is then shown that $K = K(\sigma_b)$ and $\sigma_b =
+\sigma_b(K)$ may be determined when either parameter is fully described.
+Lastly, we propose a simplified model and discuss the roles of pore-size
+distribution, saturation, pore connectivity and tortuosity in characterizing
+the relationship between $K$ and $\sigma_b$.",1801.05248v2
+2018-01-17,All-fiber all-normal-dispersion femtosecond laser with nonlinear multimodal interference based saturable absorber,"In this letter, we demonstrate the first all-fiber all-normal dispersion
+ytterbium-doped oscillator with nonlinear multimodal interference based
+saturable absorber capable to generate ultrashort dissipative soliton pulses.
+Additional to functioning as a saturable absorber, the use of multimode fiber
+segments between single mode fibers also ensures the bandpass filtering via
+multimode interference reimaging necessary to obtain dissipative soliton
+mode-locking. The oscillator generates dissipative soliton pulses at 1030 nm
+with 5.8 mW average power, 5 ps duration and 44.25 MHz repetition rate. Pulses
+are dechirped to 276 fs via an external grating compressor. All-fiber cavity
+design ensures high stability and $\sim$70 dB sideband suppression is measured
+in RF spectrum. Numerical simulations are performed to investigate cavity
+dynamics and obtained results well-matched with experimental observations. The
+proposed cavity presents an alternative approach to achieve all-fiber
+dissipative soliton mode-locking with a simple and low-cost design.",1801.05824v1
+2018-01-23,A Wideband Self-Consistent Disk-Averaged Spectrum of Jupiter Near 30 GHz and Its Implications for NH$_{3}$ Saturation in the Upper Troposphere,"We present a new set of measurements obtained with the Combined Array for
+Research in Millimeter-wave Astronomy (CARMA) of Jupiter's microwave thermal
+emission near the 1.3 cm ammonia (NH$_{3}$) absorption band. We use these
+observations to investigate the ammonia mole fraction in the upper troposphere,
+near $0.3 < P < 2$ bar, based on radiative transfer modeling. We find that the
+ammonia mole fraction must be $\sim2.4\times 10^{-4}$ below the NH$_{3}$ ice
+cloud, i.e., at $0.8 < P < 8$ bar, in agreement with results by de Pater et al.
+(2001, 2016a). We find the NH$_{3}$ cloud-forming region between $0.3 < P <
+0.8$ bar to be globally sub-saturated by 55% on average, in accordance with the
+result in Gibson et al. (2005). Although our data are not very sensitive to the
+region above the cloud layer, we are able to set an upper limit of $2.4\times
+10^{-7}$ on the mole fraction here, a factor of $\sim$10 above the saturated
+vapor curve.",1801.07812v1
+2018-02-02,Black phosphorus Q-switched and mode-locked Er:ZBLAN fiber lasers at 3.5 um,"With the proposal of dual-wavelength pumping (DWP) scheme, DWP Er:ZBLAN fiber
+lasers at 3.5 um have become a fascinating area of research. However, limited
+by the absence of suitable saturable absorber, passively Q-switched and
+mode-locked fiber lasers have not been realized in this spectral region. Based
+on the layer-dependent bandgap and excellent photoelectric characteristics of
+black phosphorus (BP), BP is a promising candidate for saturable absorber near
+3.5 um. Here, we fabricated a 3.5-um saturable absorber mirror (SAM) by
+transferring liquid-phase exfoliated BP flakes onto a gold-coated mirror. With
+the as-prepared BP SAM, we realized stable Q-switching and continuous-wave
+mode-locking operations in the DWP Er:ZBLAN fiber lasers at 3.5 um. To the best
+of our knowledge, it is the first time to achieve passively Q-switched and
+mode-locked pulses in 3.5 um spectral region. The research results will not
+only promote the development of 3.5-um pulsed fiber lasers but also open the
+photonic application of two-dimensional materials in this spectral region",1802.00710v1
+2018-02-07,Energy is Entanglement,"We compute the local second variation of the von Neumann entropy of a region
+in theories with a gravity dual. For null variations our formula says that the
+diagonal part of the Quantum Null Energy Condition is saturated in every state,
+thus providing an equivalence between energy and entropy. We prove that the
+formula holds at leading order in 1/N, and further argue that it will not be
+affected at higher orders. We conjecture that the QNEC is saturated in all
+interacting theories. We also discuss the special case of free theories, and
+the implications of our formula for the Averaged Null Energy Condition, Quantum
+Focusing Conjecture, and gravitational equations of motion. We show that the
+leading-order gravitational equations of motion, Einstein's equations, are
+equivalent to leading-order saturation of the QFC for Planck-width
+deformations.",1802.02584v1
+2018-02-22,When gluons go odd: how classical gluon fields generate odd azimuthal harmonics for the two-gluon correlation function in high-energy collisions,"We show that, in the saturation/Color Glass Condensate framework, odd
+azimuthal harmonics of the two-gluon correlation function with a long-range
+separation in rapidity are generated by the higher-order saturation corrections
+in the interactions with the projectile and the target. At the very least, the
+odd harmonics require three scatterings in the projectile and three scatterings
+in the target. We derive the leading-order expression for the two-gluon
+production cross section which generates odd harmonics: the expression includes
+all-order interactions with the target and three interactions with the
+projectile. We evaluate the obtained expression both analytically and
+numerically, confirming that the odd-harmonics contribution to the two-gluon
+production in the saturation framework is non-zero.",1802.08166v1
+2018-03-12,Supersymmetrising the GSY Soliton,"We supersymmetrise the Hopfion studied in a previous work. This soliton
+represents a closed semilocal vortex string in $U(1)$ gauge theory. It carries
+nonzero Hopf number due to the additional winding of a phase modulus as one
+moves along the closed string. We study this solution in $\mathcal{N}= 2$
+supersymmetric QED with two flavours. As a preliminary exercise we compactify
+one space dimension and consider a straight vortex with periodic boundary
+conditions. It turns out to be 1/2-BPS saturated. An additional winding along
+the string can be introduced and it does not spoil the BPS nature of the
+object. Next, we consider a ring-like vortex in a non-compact space and show
+that the circumference of the ring $L$ can be stabilised once the previously
+mentioned winding along the string is introduced. Of course the ring-like
+vortex is not BPS but its energy becomes close to the BPS bound if $L$ is
+large, which can be guaranteed in the case that we have a large value of the
+angular momentum $J$. Thus we arrive at the concept of asymptotically
+BPS-saturated solitons. BPS saturation is achieved in the limit $J\rightarrow
+\infty$.",1803.04549v2
+2018-03-24,Saturated Fully Leafed Tree-Like Polyforms and Polycubes,"We present recursive formulas giving the maximal number of leaves in
+tree-like polyforms living in two-dimensional regular lattices and in tree-like
+polycubes in the three-dimensional cubic lattice.
+  We call these tree-like polyforms and polycubes \emph{fully leafed}.
+  The proof relies on a combinatorial algorithm that enumerates rooted directed
+trees that we call abundant.
+  In the last part, we concentrate on the particular case of polyforms and
+polycubes, that we call \emph{saturated}, which is the family of fully leafed
+structures that maximize the ratio
+  $\mbox{(number of leaves)}/\mbox{ (number of cells)}$.
+  In the polyomino case, we present a bijection between the set of saturated
+tree-like polyominoes of size $4k+1$ and the set of tree-like polyominoes of
+size $k$.
+  We exhibit a similar bijection between the set of saturated tree-like
+polycubes of size $41k+28$ and a family of polycubes, called $4$-trees, of size
+$3k+2$.",1803.09181v1
+2018-04-01,Nonlinear Spectroscopic Study of Porphyrin Under cw and Femto-second Laser Pulse Excitation,"Single Beam Transmittance (SBT) was used as nonlinear spectroscopic tool to
+investigate the absorption cross-sections and lifetimes of Tetra Phenyl
+porphyrin (H2TPP) and its OH- group derivative (H2TPP(OH)4) doped in boric acid
+glass (BAG). We have used 671 nm wavelength as exciting wavelength for both CW
+(incident intensity up to 1010 W/cm2) and femto-second laser pulse (up to
+fluence of 102 mJ/cm2). Under cw laser excitation, H2TPP doped BAG demonstrates
+Double Saturable Absorber (DSA) behavior whereas H2TPP(OH)4 doped BAG act as
+Revere Saturable Absorber (RSA). Rate equation model espouses to extract the
+spectroscopic parameters from the experimental data. Excited state life times
+and absorption cross-sections were obtained as parameters for theoretical fit
+on SBT data. Porphyrin molecules act as four level systems under cw laser
+excitation, whereas in the presence of femto-second laser excitation they act
+as a two level system. We have derived the equations for transmitted energy
+through the material in the presence of femto-second laser illumination. Both
+systems viz., H2TPP and H2TPP(OH)4 doped BAG behaves as saturable absorbers
+when excited by femto-second laser pulses.",1804.00288v1
+2018-04-15,In depth analysis of the combined HERA data in the dipole models with and without saturation,"We present an updated impact parameter dependent saturation model (IPsat)
+determined trough a fit to the combined HERA I and I+II reduced cross section
+data. The same HERA data are used to fit the linearized (IPnonsat) version of
+the applied dipole amplitude, which makes it possible to estimate the magnitude
+of the saturation effects in various experiments. We find that both
+parametrizations provide comparable descriptions of the considered data when an
+effective confinement scale dynamics is incorporated with quark masses.
+Moreover, it is possible to consistently determine the light and charm quark
+masses. The role of potentially non-perturbatively large dipoles is examined in
+detail, with the result that, especially in case of the structure function
+$F_2$, their contribution is numerically significant. Potential to discriminate
+between the two models in future $e+p$ and $e+A$ experiments is also
+illustrated.",1804.05311v2
+2018-04-17,Multivariate Gaussian Process Regression for Multiscale Data Assimilation and Uncertainty Reduction,"We present a multivariate Gaussian process regression approach for parameter
+field reconstruction based on the field's measurements collected at two
+different scales, the coarse and fine scales. The proposed approach treats the
+parameter field defined at fine and coarse scales as a bivariate Gaussian
+process with a parameterized multiscale covariance model. We employ a full
+bivariate Mat\'{e}rn kernel as multiscale covariance model, with shape and
+smoothness hyperparameters that account for the coarsening relation between
+fine and coarse fields. In contrast to similar multiscale kriging approaches
+that assume a known coarsening relation between scales, the hyperparameters of
+the multiscale covariance model are estimated directly from data via
+pseudo-likelihood maximization.
+  We illustrate the proposed approach with a predictive simulation application
+for saturated flow in porous media. Multiscale Gaussian process regression is
+employed to estimate two-dimensional log-saturated hydraulic conductivity
+distributions from synthetic multiscale measurements. The resulting stochastic
+model for coarse saturated conductivity is employed to quantify and reduce
+uncertainty in pressure predictions.",1804.06490v1
+2018-04-19,Estimation of Tissue Oxygen Saturation from RGB Images based on Pixel-level Image Translation,"Intra-operative measurement of tissue oxygen saturation (StO2) has been
+widely explored by pulse oximetry or hyperspectral imaging (HSI) to assess the
+function and viability of tissue. In this paper we propose a pixel- level
+image-to-image translation approach based on conditional Generative Adversarial
+Networks (cGAN) to estimate tissue oxygen saturation (StO2) directly from RGB
+images. The real-time performance and non-reliance on additional hardware,
+enable a seamless integration of the proposed method into surgical and
+diagnostic workflows with standard endoscope systems. For validation, RGB
+images and StO2 ground truth were simulated and estimated from HSI images
+collected by a liquid crystal tuneable filter (LCTF) endoscope for three tissue
+types (porcine bowel, lamb uterus and rabbit uterus). The result show that the
+proposed method can achieve visually identical images with comparable accuracy.",1804.07116v1
+2018-04-24,The Sprague-Grundy Functions of Saturations of Misere Nim,"We consider mis\`{e}re Nim as a normal-play game obtained from Nim by
+removing the terminal position. While explicit formulas are known for the
+Sprague-Grundy functions of Nim and Welter's game, no explicit formula is known
+for that of mis\`{e}re Nim. All three of these games can be considered as
+position restrictions of Nim. What are the differences between them? We point
+out that Nim and Welter's game are saturated, but mis\`{e}re Nim is not.
+Moreover, we present explicit formulas for the Sprague-Grundy functions of
+saturations of mis\`{e}re Nim, which are obtained from mis\`{e}re Nim by
+adjoining some moves.",1804.08809v4
+2018-05-03,Solvation effects and contact angle saturation in electrowetting,"Electrowetting of nanodrops is studied for aqueous electrolyte mixtures. We
+report a new method for controlling the degree of deformation and minimum
+attainable contact angle by varying the difference of solvation strengths
+between the two solvents, which determines the ratio of ion concentrations.
+This implies that the commonly observed saturation of the contact angle with
+the applied electric field can be suppressed by increasing the solvation energy
+difference, a finding of practical significance for micro and nanofluidics.
+Saturation is traced to be caused by the transfer of ions from the drop to the
+surrounding medium. Furthermore, we derive an expression, based on the
+electrokinetic equations, for the dependency of the drop's contact angle on the
+ion concentration and the strength of the solvation potential in the absence of
+external electric fields.",1805.01351v2
+2018-05-27,Efficiently Modeling the Noise Performance of Short-Pulse Lasers with a Computational Implementation of Dynamical Methods,"Lowering the noise level of short pulse lasers has been a long-standing
+effort for decades. Modeling the noise performance plays a crucial role in
+isolating the noise sources and reducing them. Modeling to date has either used
+analytical or semi-analytical implementation of dynamical methods or Monte
+Carlo simulations. The former approach is too simplified to accurately assess
+the noise performance in real laser systems, while the latter approach is too
+computationally slow to optimize the performance as parameters vary over a wide
+range. Here, we describe a computational implementation of dynamical methods
+that allows us to determine the noise performance of a passively modelocked
+laser within minutes on a desktop computer and is faster than Monte Carlo
+methods by a factor on the order of 1000. We apply this method to characterize
+a laser that is locked using a fast saturable absorber---for example, a
+fiber-based nonlinear polarization rotation---and a laser that is locked using
+a slow saturable absorber---for example, a semiconductor saturable absorbing
+mirror.",1806.04601v1
+2018-06-27,"Towards the Quantum Geometry of Saturated Quantum Uncertainty Relations: The Case of the (Q,P) Heisenberg Observables","This contribution to the present Workshop Proceedings outlines a general
+programme for identifying geometric structures--out of which to possibly
+recover quantum dynamics as well--associated to the manifold in Hilbert space
+of the quantum states that saturate the Schr\""odinger-Robertson uncertainty
+relation associated to a specific set of quantum observables which characterise
+a given quantum system and its dynamics. The first step in such an exploration
+is addressed herein in the case of the observables Q and P of the Heisenberg
+algebra for a single degree of freedom system. The corresponding saturating
+states are the well known general squeezed states, whose properties are
+reviewed and discussed in detail together with some original results, in
+preparation of a study deferred to a separated analysis of their quantum
+geometry and of the corresponding path integral representation over such
+states.",1806.10491v1
+2018-07-03,Mode-locked fiber laser with offset splicing between two multimode fibers as a saturable absorber,"A novel mode-locked fiber laser based on offset splicing technology between
+two kinds of graded index multimode fibers is proposed and experimentally
+demonstrated. The offset splice spot structure acts as a saturable absorber via
+nonlinear multimodal interference mechanism. The absorption modulation depth of
+the device is 2.8%, with a saturation intensity of 2.5 MW/cm2. The fiber laser
+operates at a stable mode-locked state when the pump power reaches 114 mW. The
+laser oscillates at 1039 nm with a pulsewidth of 17.6 ps, a repetition rate of
+32.619 MHz, and a high signal noise ratio of 65 dB. The fiber laser is superior
+in terms of low cost, high damage threshold, and easy fabrication, thus
+providing many potential applications in ultrafast photonics and industrial
+processing.",1807.01037v1
+2018-07-04,Steep cliffs and saturated exponents in three dimensional scalar turbulence,"The intermittency of a passive scalar advected by three-dimensional
+Navier-Stokes turbulence at a Taylor-scale Reynolds number of $650$ is studied
+using direct numerical simulations on a $4096^3$ grid; the Schmidt number is
+unity. By measuring scalar increment moments of high orders, while ensuring
+statistical convergence, we provide unambiguous evidence that the scaling
+exponents saturate to $1.2$ for moment order beyond about $12$, indicating that
+scalar intermittency is dominated by the most singular shock-like cliffs in the
+scalar field. We show that the fractal dimension of the spatial support of
+steep cliffs is about $1.8$, whose sum with the saturation exponent value of
+$1.2$ adds up to the space dimension of $3$, thus demonstrating a deep
+connection between the geometry and statistics in turbulent scalar mixing. The
+anomaly for the fourth and sixth order moments is comparable to that in the
+Kraichnan model for the roughness exponent of $2/3$.",1807.01651v1
+2018-07-08,Attractivity of Saturated Equilibria for Lotka-Volterra Systems with Infinite Delays and Feedback Controls,"In this paper, we apply a Lyapunov functional approach to Lotka-Volterra
+systems with infinite delays and feedback controls and establish that the
+feedback controls have no influence on the attractivity properties of a
+saturated equilibrium. This improves previous results by the authors and
+others, where, while feedback controls were used mostly to change the position
+of a unique saturated equilibrium, additional conditions involving the controls
+had to be assumed in order to preserve its global attractivity. The situation
+of partial extinction is further analysed, for which the original system is
+reduced to a lower dimensional one which maintains its global dynamics
+features.",1807.02825v1
+2018-07-16,Qualitative Analysis and Optimal Control Strategy of an SIR Model with Saturated Incidence and Treatment,"This paper deals with an SIR model with saturated incidence rate affected by
+inhibitory effect and saturated treatment function. Two control functions have
+been used, one for vaccinating the susceptible population and other for the
+treatment control of infected population. We have analysed the existence and
+stability of equilibrium points and investigated the transcritical and backward
+bifurcation. The stability analysis of non-hyperbolic equilibrium point has
+been performed by using Centre manifold theory. The Pontryagin's maximum
+principle has been used to characterize the optimal control whose numerical
+results show the positive impact of two controls mentioned above for
+controlling the disease. Efficiency analysis is also done to determine the best
+control strategy among vaccination and treatment.",1807.05954v1
+2018-07-17,Signature of gluon saturation in forward di-hadron correlations at the Large Hadron Collider,"We argue that gluon saturation effects may be visible in Large Hadron
+Collider (LHC) data. We look at the centrality dependence of the away-side peak
+of two-particle correlations measured in p-Pb collisions, using both ALICE data
+at midrapidity, and LHCb data at forward rapidity. Once the collective
+flow-like signal measured at the near-side peak is removed from the correlation
+function, the centrality dependence of the away-side peak turns out to be much
+stronger in the forward region than at midrapidity. We argue that this is a
+very specific prediction of the saturation framework, and we compare LHCb data
+to a state-of-the-art calculation within the Color Glass Condensate theory.",1807.06388v1
+2018-09-11,Analytical model for the intensity dependence of 1500 nm to 980 nm upconversion in Er$^{3+}$: a new tool for material characterization,"We propose a simplified rate-equation model for the 1500 nm to 980 nm
+upconversion in Er$^{3+}$. The simplifications, based on typical experimental
+conditions as well as on conclusions based on previously published more
+advanced models, enable an analytical solution of the rate equations, which
+reproduces known properties of upconversion. We have compared the model
+predictions with intensity-dependent measurements on four samples with
+different optical properties, such as upconversion-luminescence yield and the
+characteristic lifetime of the $^4I_{13/2}$ state. The saturation of the
+upconversion is in all cases well-described by the model over several orders of
+magnitude in excitation intensities. Finally, the model provides a new measure
+for the quality of upconverter systems based on Er$^{3+}$ -- the saturation
+intensity. This parameter provides valuable information on upconversion
+parameters such as the rates of energy-transfer upconversion and
+cross-relaxation. In the present investigation, we used the saturation
+intensity to conclude that the differences in upconversion performance of the
+investigated samples are mainly due to differences in the non-radiative
+relaxation rates.",1809.03908v1
+2018-09-13,Complexity Growth Following Multiple Shocks,"In this paper by making use of the ""Complexity=Action"" proposal, we study the
+complexity growth after shock waves in holographic field theories. We consider
+both double black hole-Vaidya and AdS-Vaidya with multiple shocks geometries.
+We find that the Lloyd's bound is respected during the thermalization process
+in each of these geometries and at the late time, the complexity growth
+saturates to the value which is proportional to the energy of the final state.
+We conclude that the saturation value of complexity growth rate is independent
+of the initial temperature and in the case of thermal initial state, the rate
+of complexity is always less than the value for the vacuum initial state such
+that considering multiple shocks it gets more smaller. Our results indicate
+that by increasing the temperature of the initial state, the corresponding rate
+of complexity growth starts far from final saturation rate value.",1809.05044v3
+2018-09-13,Yb-doped all fiber picosecond laser based on grade-index multimode fiber with microcavity,"We demonstrate an all-fiber mode-locked laser at all-normal dispersion with a
+saturable absorber, which is based on a section of grade-index multimode fiber
+with inner microcavity embedded in the splice points. The absorption modulation
+depth of this nonlinear saturable absorber is 2.2% in the suitable bent state.
+The fiber laser operates at central wavelength of 1035nm with average power of
+~1.26mW, pulse-duration of 17.05 ps, repetition rate of 37.098MHz. This kind of
+saturable absorber has superiorities of low cost, high stability and high
+damage threshold, which may facilitate applications in optical sensing,
+material processing and light detection.",1809.07174v2
+2018-09-22,Understanding the saturation power of Josephson Parametric Amplifiers made from SQUIDs arrays,"We report on the implementation and detailed modelling of a Josephson
+Parametric Amplifier (JPA) made from an array of eighty Superconducting QUantum
+Interference Devices (SQUIDs), forming a non-linear quarter-wave resonator.
+This device was fabricated using a very simple single step fabrication process.
+It shows a large bandwidth (45 MHz), an operating frequency tunable between 5.9
+GHz and 6.8 GHz and a large input saturation power (-117 dBm) when biased to
+obtain 20 dB of gain. Despite the length of the SQUID array being comparable to
+the wavelength, we present a model based on an effective non-linear LC series
+resonator that quantitatively describes these figures of merit without fitting
+parameters. Our work illustrates the advantage of using array-based JPA since a
+single-SQUID device showing the same bandwidth and resonant frequency would
+display a saturation power 15 dB lower.",1809.08476v2
+2018-09-12,Fast Signal Recovery from Saturated Measurements by Linear Loss and Nonconvex Penalties,"Sign information is the key to overcoming the inevitable saturation error in
+compressive sensing systems, which causes information loss and results in bias.
+For sparse signal recovery from saturation, we propose to use a linear loss to
+improve the effectiveness from existing methods that utilize hard
+constraints/hinge loss for sign consistency. Due to the use of linear loss, an
+analytical solution in the update progress is obtained, and some nonconvex
+penalties are applicable, e.g., the minimax concave penalty, the $\ell_0$ norm,
+and the sorted $\ell_1$ norm. Theoretical analysis reveals that the estimation
+error can still be bounded. Generally, with linear loss and nonconvex
+penalties, the recovery performance is significantly improved, and the
+computational time is largely saved, which is verified by the numerical
+experiments.",1809.09219v1
+2018-10-13,$C_{2k}$-saturated graphs with no short odd cycles,"The saturation number of a graph $F$, written $\textup{sat}(n,F)$, is the
+minimum number of edges in an $n$-vertex $F$-saturated graph. One of the
+earliest results on saturation numbers is due to Erd\H{o}s, Hajnal, and Moon
+who determined $\textup{sat}(n,K_r)$ for all $r \geq 3$. Since then, saturation
+numbers of various graphs and hypergraphs have been studied. Motivated by Alon
+and Shikhelman's generalized Tur\'an function, Kritschgau et.\ al.\ defined
+$\textup{sat}(n,H,F)$ to be the minimum number of copies of $H$ in an
+$n$-vertex $F$-saturated graph. They proved, among other things, that
+$\textup{sat}(n,C_3,C_{2k}) = 0$ for all $k \geq 3$ and $n \geq 2k +2$. We
+extend this result to all odd cycles by proving that for any odd integer $r
+\geq 5$, $\textup{sat}(n, C_r,C_{2k}) = 0$ for all $2k \geq r+5$ and $n \geq
+2kr$.",1810.05772v1
+2018-10-17,Cross-diffusion and traveling waves in porous-media flux-saturated Keller-Segel models,"This paper deals with the analysis of qualitative properties involved in the
+dynamics of Keller-Segel type systems in which the diffusion mechanisms of the
+cells are driven by porous-media flux-saturated phenomena. We study the
+regularization inside the support of a solution with jump discontinuity at the
+boundary of the support. We analyze the behavior of the size of the support and
+blow--up of the solution, and the possible convergence in finite time towards a
+Dirac mass in terms of the three constants of the system: the mass, the
+flux--saturated characteristic speed, and the chemoattractant sensitivity
+constant. These constants of motion also characterize the dynamics of regular
+and singular traveling waves.",1810.07606v1
+2018-10-17,Non-local competition slows down front acceleration during dispersal evolution,"We investigate the super-linear spreading in a reaction-diffusion model
+analogous to the Fisher-KPP equation, but in which the population is
+heterogeneous with respect to the dispersal ability of individuals, and the
+saturation factor is non-local with respect to one variable. We prove that the
+rate of acceleration is slower than the rate of acceleration predicted by the
+linear problem, that is, without saturation. This hindering phenomenon is the
+consequence of a subtle interplay between the non-local saturation and the
+non-trivial dynamics of some particular curves that carry the mass at the
+front. A careful analysis of these trajectories allows us to identify the value
+of the rate of acceleration. The article is complemented with numerical
+simulations that illustrate some behavior of the model that is beyond our
+analysis.",1810.07634v2
+2018-10-18,Recovery of Saturated $γ$ Signal Waveforms by Artificial Neural Networks,"Particle may sometimes have energy outside the range of radiation detection
+hardware so that the signal is saturated and useful information is lost. We
+have therefore investigated the possibility of using an Artificial Neural
+Network (ANN) to restore the saturated waveforms of $\gamma$ signals. Several
+ANNs were tested, namely the Back Propagation (BP), Simple Recurrent (Elman),
+Radical Basis Function (RBF) and Generalized Radial Basis Function (GRBF)
+neural networks (NNs) and compared with the fitting method based on the Marrone
+model. The GBRFNN was found to perform best.",1810.08200v1
+2018-10-30,Two-Photon Absorption and Saturable Absorption of Mid-IR in Graphene,"We report on the response of graphene to high intensity mid-IR radiation and
+show that graphene exhibits saturable absorption and significant two-photon
+absorption in the spectral region from 1.55 $\mu$m to 3.50 $\mu$m (0.35 eV to
+0.80 eV). We find that the effective modulation depth of multilayer graphene is
+limited by two-photon absorption which will affect its performance as a laser
+mode-locking element. The measured saturation intensities of femtosecond pulses
+were found to depend on the third power of photon energy when we combined our
+results with others reported in literature, while those of longer pulses were
+found to have a square root dependence.",1810.12981v1
+2018-12-02,Nearly-Regular Hypergraphs and Saturation of Berge Stars,"Given a graph $G$, we say a $k$-uniform hypergraph $H$ on the same vertex set
+contains a Berge-$G$ if there exists an injection $\phi:E(G)\to E(H)$ such that
+$e\subseteq\phi(e)$ for each edge $e\in E(G)$. A hypergraph $H$ is
+Berge-$G$-saturated if $H$ does not contain a Berge-$G$, but adding any edge to
+$H$ creates a Berge-$G$. The saturation number for Berge-$G$, denoted
+$\mathrm{sat}_k(n,\text{Berge-}G)$ is the least number of edges in a
+$k$-uniform hypergraph that is Berge-$G$-saturated. We determine exactly the
+value of the saturation numbers for Berge stars. As a tool for our main result,
+we also prove the existence of nearly-regular $k$-uniform hypergraphs, or
+$k$-uniform hypergraphs in which every vertex has degree $r$ or $r-1$ for some
+$r\in \mathbb{Z}$, and less than $k$ vertices have degree $r-1$.",1812.00472v1
+2018-12-11,Capillary transport in low saturated sands: superfast non-linear diffusion model versus direct experimental observations,"We have established in a pilot study, that the spreading of liquids in sandy
+porous materials at low levels of saturation, typically less than ten percent
+of the available void space, has very distinctive features in comparison to
+that at higher saturation levels. In particular, it has been shown, on
+theoretical grounds, that the spreading is controlled by a special type of
+diffusional process, that its physics can be captured by an equation of the
+super-fast diffusion class, and that these findings were supported by
+first-of-a-kind experiments. In this paper, we take these findings to the next
+level including deeper examination and exposition of the theory, an expanded
+set of experiments to address scaling properties, and systematic evaluations of
+the predictive performance against these experimental data, keeping in mind
+also potential practical applications.",1812.04710v1
+2018-12-17,Quantification of nonlinear absorption in ternary As-Sb-Se chalcogenide glasses,"In this article, we studied intensity dependent third order nonlinear optical
+response in ternary As40Sb7Se53 and As40Sb10Se50 chalcogenide glasses by
+employing nanosecond Z-scan technique. At low intensity, we observed saturable
+absorption in As40Sb7Se53 which makes a remarkable transition to reverse
+saturable absorption at higher intensities. On the other hand, when the Sb
+concentration increased in As40Sb10Se50, saturable absorption disappears and
+the sample exhibits only two-photon absorption. Experimental results further
+indicate that the strong two-photon absorption in our samples can be exploited
+to fabricate high performance solid state optical limiting devices for next
+generation all-optical network.",1812.06674v1
+2019-01-01,Infrared Laser Locking to Rubidium Saturated Absorption Spectrum via a Photonic Chip Frequency Doubler,"Photonic integrated resonators stand out as reliable frequency converters due
+to their compactness and stability, with second-harmonic generation (SHG)
+efficiencies of up to 17000%/W reported recently in aluminum nitride
+microrings. In this work, a sufficiently strong second-harmonic (SH) signal up
+to microwatts was generated by a photonic integrated frequency doubler using a
+milliwatt infrared (IR) laser source. Furthermore, increased SHG bandwidth
+covering $^{85}$Rb and $^{87}$Rb D$_2$ transition lines as well as saturated
+absorption spectroscopy (SAS) were demonstrated by tuning the pump power and
+chip temperature. Here, we present, to the best of our knowledge, the first
+successful locking of an IR laser to Rb saturated absorption lines via a
+photonic chip frequency doubler.",1901.00922v1
+2019-01-27,Distributed Nash Equilibrium Seeking for Games in Systems with Bounded Control Inputs,"Noticing that physical limitations are ubiquitous in practical engineering
+systems, this paper considers Nash equilibrium seeking for games in systems
+where the control inputs are bounded. More specifically, first-order
+integrator-type systems with bounded control inputs are firstly considered and
+two saturated control strategies are designed to seek for the Nash equilibrium
+of the game. Then, we further consider the Nash equilibrium seeking problem for
+games in second-order integrator-type systems. As this problem has rarely been
+investigated, we firstly propose a centralized seeking strategy without
+considering the boundedness of the control inputs, followed by a distributed
+counterpart. By further adapting a saturation function into the Nash
+equilibrium seeking strategy, a new seeking strategy is then designed for the
+considered second-order systems with bounded controls. In the proposed
+distributed strategies, consensus protocols are included for information
+sharing and the saturation functions are utilized to construct bounded control
+inputs. The convergence results are established through conducting Lyapunov
+stability analysis. Lastly, by considering the connectivity control of mobile
+sensor networks, the proposed methods are numerically verified.",1901.09333v2
+2019-01-29,Preferential Root Tropism Induced by Structural Inhomogeneities in 2D Wet Granular Media,"We investigate certain aspects of the physical mechanisms of root growth in a
+granular medium and how these roots adapt to changes in water distribution
+induced by the presence of structural inhomogeneities in the form of solid
+intrusions. Physical intrusions such as a square rod added into the 2D granular
+medium modify water distribution by maintaining robust capillary action,
+pumping water from the more saturated areas at the bottom of the cell towards
+the less saturated areas near the top of the cell while the rest of the medium
+is slowly devoid of water via evaporation. This water redistribution induces
+`preferential tropism' of roots, guiding the roots and permitting them to grow
+deeper into more saturated regions in the soil. This further allows more
+efficient access to available water in the deeper sections of the medium
+thereby resulting to increased plant lifetime",1901.10402v1
+2019-02-21,Thermal radiation and inclusive production in the CGC/saturation approach at high energies,"In this paper, we discuss the inclusive production of hadrons in the
+framework of CGC/saturation approach. We argue, that the gluon jet inclusive
+production stems from the vicinity of the saturation momentum, even for small
+values of the transverse momenta $p_T$. Since in this region, theoretically, we
+know the scattering amplitude, we claim that we can provide reliable estimates
+for this process. We demonstrate, that in a widely accepted model for
+confinement, to describe the experimental data, we require a thermal radiation
+term. In this model the parton (quark or gluon) with the transverse momenta of
+the order of $Q_s$ decays into hadrons with the given fragmentation functions.
+However, we show that other approaches for the confinement could describe the
+data, without a need for the thermal emission",1902.07923v2
+2019-02-24,Optimality Conditions for Nonconvex Variational Problems with Integral Constraints in Banach Spaces,"This paper exemplifies that saturation is an indispensable structure on
+measure spaces to obtain the existence and characterization of solutions to
+nonconvex variational problems with integral constraints in Banach spaces and
+their dual spaces. We provide a characterization of optimality via the maximum
+principle for the Hamiltonian and an existence result without the purification
+of relaxed controls, in which the Lyapunov convexity theorem in infinite
+dimensions under the saturation hypothesis on the underlying measure space
+plays a crucial role. We also demonstrate that the existence of solutions for
+certain class of primitives is necessary and sufficient for the measure space
+to be saturated.",1902.09533v3
+2019-03-14,Symmetry energy at supra-saturation densities via the Gravitational Waves from GW170817,"Motivated by the historical detection of gravitational waves from GW170817,
+the neutron star and the neutron drop, i.e., a certain number of neutrons
+confined in an external field, are systematically investigated by ab initio
+calculations as well as the nonrelativistic and relativistic state-of-art
+density functional theories. Strong correlations are found among the neutron
+star tidal deformability, the neutron star radius, the root-mean-square radii
+of neutron drops, and the symmetry energies of nuclear matter at
+supra-saturation densities. From these correlations and the upper limit on the
+tidal deformability extracted from GW170817, the neutron star radii, the
+neutron drop radii, and the symmetry energy at twice saturation density are
+respectively constrained as $R_{1.4M_{\odot}}\leqslant 12.94$ km, $R_{\rm nd}
+\leqslant 2.36$ fm, and $E_{\mathrm{sym}}(2\rho_0) \leqslant 53.2$ MeV.",1903.05938v1
+2019-04-08,Desaturating EUV observations of solar flaring storms,"Image saturation has been an issue for several instruments in solar
+astronomy, mainly at EUV wavelengths. However, with the launch of the
+Atmospheric Imaging Assembly (AIA) as part of the payload of the Solar Dynamic
+Observatory (SDO) image saturation has become a big data issue, involving
+around 10^$ frames of the impressive dataset this beautiful telescope has been
+providing every year since February 2010. This paper introduces a novel
+desaturation method, which is able to recover the signal in the saturated
+region of any AIA image by exploiting no other information but the one
+contained in the image itself. This peculiar methodological property, jointly
+with the unprecedented statistical reliability of the desaturated images, could
+make this algorithm the perfect tool for the realization of a reconstruction
+pipeline for AIA data, able to work properly even in the case of long-lasting,
+very energetic flaring events.",1904.04211v1
+2019-04-17,Low temperature saturation of phase coherence length in topological insulators,"Implementing topological insulators as elementary units in quantum
+technologies requires a comprehensive understanding of the dephasing mechanisms
+governing the surface carriers in these materials, which impose a practical
+limit to the applicability of these materials in such technologies requiring
+phase coherent transport. To investigate this, we have performed
+magneto-resistance (MR) and conductance fluctuations\ (CF) measurements in both
+exfoliated and molecular beam epitaxy grown samples. The phase breaking length
+($l_{\phi}$) obtained from MR shows a saturation below sample dependent
+characteristic temperatures, consistent with that obtained from CF
+measurements. We have systematically eliminated several factors that may lead
+to such behavior of $l_{\phi}$ in the context of TIs, such as finite size
+effect, thermalization, spin-orbit coupling length, spin-flip scattering, and
+surface-bulk coupling. Our work indicates the need to identify an alternative
+source of dephasing that dominates at low $T$ in topological insulators,
+causing saturation in the phase breaking length and time.",1904.08517v1
+2019-04-23,Maser Flare Simulations from Oblate and Prolate Clouds,"We investigated, through numerical models, the flaring variability that may
+arise from the rotation of maser clouds of approximately spheroidal geometry,
+ranging from strongly oblate to strongly prolate examples. Inversion solutions
+were obtained for each of these examples over a range of saturation levels from
+unsaturated to highly saturated. Formal solutions were computed for rotating
+clouds with many randomly chosen rotation axes, and corresponding averaged
+maser light curves plotted with statistical information. The dependence of
+results on the level of saturation and on the degree of deformation from the
+spherical case were investigated in terms of a variability index and duty
+cycle. It may be possible to distinguish observationally between flares from
+oblate and prolate objects. Maser flares from rotation are limited to long
+timescales (at least a few years) and modest values of the variability index
+($\lesssim 100$), and can be aperiodic or quasi-periodic. Rotation is therefore
+not a good model for H$_2$O variability on timescales of weeks to months, or of
+truly periodic flares.",1904.10347v1
+2019-05-01,Anomalous diffusion in an electrolyte saturated paper matrix,"Diffusion of colored dye on water saturated paper substrates has been
+traditionally exploited with great skill by renowned water color artists. The
+same physics finds more recent practical applications in paper based diagnostic
+devices deploying chemicals that react with a bodily fluid yielding
+colorimetric signals for disease detection. During spontaneous imbibition
+through the tortuous pathways of a porous electrolyte saturated paper matrix, a
+dye molecule undergoes diffusion in a complex network of pores. The advancing
+front forms a strongly correlated interface that propagates diffusively but
+with an enhanced effective diffusivity. We measure this effective diffusivity
+and show that it is several orders of magnitude greater than the free solution
+diffusivity and has a significant dependence on the solution pH and salt
+concentration in the background electrolyte. We attribute this to electrically
+mediated interfacial interactions between the ionic species in the liquid dye
+and spontaneous surface charges developed at porous interfaces, and introduce a
+simple theory to explain this phenomenon.",1905.03347v1
+2019-06-10,k-Means Aperture Optimization Applied to Kepler K2 Time Series Photometry of Titan,"Motivated by the Kepler K2 time series of Titan, we present an aperture
+optimization technique for extracting photometry of saturated moving targets
+with high temporally- and spatially-varying backgrounds. Our approach uses
+$k$-means clustering to identify interleaved families of images with similar
+Point-Spread Function and saturation properties, optimizes apertures for each
+family independently, then merges the time series through a normalization
+procedure. By applying $k$-means aperture optimization to the K2 Titan data, we
+achieve $\leq$0.33% photometric scatter in spite of background levels varying
+from 15% to 60% of the target's flux. We find no compelling evidence for
+signals attributable to atmospheric variation on the timescales sampled by
+these observations. We explore other potential applications of the $k$-means
+aperture optimization technique, including testing its performance on a
+saturated K2 eclipsing binary star. We conclude with a discussion of the
+potential for future continuous high-precision photometry campaigns for
+revealing the dynamical properties of Titan's atmosphere.",1906.04220v1
+2019-06-26,Level inversion in kaonic nuclei and the high-density nuclear equation of state,"It is very difficult for any nuclear model to pin down the saturation
+property and high-density equation of state (EOS) simultaneously because of
+high nonlinearity of the nuclear many-body problem. In this work, we propose,
+for the first time, to use the special property of light kaonic nuclei to
+characterize the relation between saturation property and high-density EOS.
+With a series of relativistic mean-field models, this special property is found
+to be the level inversion between orbitals $2S_{1/2}$ and $1D_{5/2}$ in light
+kaonic nuclei. This level inversion can serve as a theoretical laboratory to
+group the incompressibility at saturation density and the EOS at supra-normal
+densities simultaneously.",1906.10868v1
+2019-07-18,The closure-complement-frontier problem in saturated polytopological spaces,"Let $X$ be a space equipped with $n$ topologies $\tau_1,...,\tau_n$ which are
+pairwise comparable and saturated, and for each $1\leq i\leq n$ let $k_i$ and
+$f_i$ be the associated topological closure and frontier operators,
+respectively. Inspired by the closure-complement theorem of Kuratowski, we
+prove that the monoid of set operators $\mathcal{KF}_n$ generated by
+$\{k_i,f_i:1\leq i\leq n\}\cup\{c\}$ (where $c$ denotes the set complement
+operator) has cardinality no more than $2p(n)$ where
+$p(n)=\frac{5}{24}n^4+\frac{37}{12}n^3+\frac{79}{24}n^2+\frac{101}{12}n+2$. The
+bound is sharp in the following sense: for each $n$ there exists a saturated
+polytopological space $(X,\tau_1,...,\tau_n)$ and a subset $A\subseteq X$ such
+that repeated application of the operators $k_i, f_i, c$ to $A$ will yield
+exactly $2p(n)$ distinct sets. In particular, following the tradition for
+Kuratowski-type problems, we exhibit an explicit initial set in $\mathbb{R}$,
+equipped with the usual and Sorgenfrey topologies, which yields $2p(2)=120$
+distinct sets under the action of the monoid $\mathcal{KF}_2$.",1907.08203v3
+2019-08-05,Free surface lump wave dynamics of a saturated superfluid Helium film with nontrivial boundary condition at the substrate surface,"In this article, the free surface wave dynamics of a saturated superfluid
+Helium film is considered under the condition that there exists a very weak
+downward localized superfluid flow into the substrate. For saturated film, the
+effect of surface tension plays a decisive role in the surface wave evolution
+dynamics of the system. The free surface evolution is shown to be governed by
+forced Kadomtsev Petviashvili-I equation, with the forcing function depending
+on downward superfluid velocity at the substrate surface. Exact as well as
+perturbative free surface lump wave solutions of the (2+1) dimensional
+nonlinear evolution equation are obtained and the effect of the leakage
+velocity function on the lump wave solutions are shown.",1908.01512v2
+2019-08-13,Superfast amplification and superfast nonlinear saturation of perturbations as the mechanism of turbulence,"Ruelle predicted that the maximal amplification of perturbations in
+homogeneous isotropic turbulence is exponential $e^{\sigma \sqrt{Re} t}$ (where
+$\sigma \sqrt{Re}$ is the maximal Liapunov exponent). In our earlier works, we
+predicted that the maximal amplification of perturbations in fully developed
+turbulence is faster than exponential $e^{\sigma \sqrt{Re} \sqrt{t} +\sigma_1
+t}$. That is, we predicted superfast initial amplification of perturbations.
+Built upon our earlier numerical verification of our prediction, here we
+conduct a large numerical verification with resolution up to $2048^3$ and
+Reynolds number up to $6210$. Our direct numerical simulation here confirms our
+analytical prediction. Our numerical simulation also demonstrates that such
+superfast amplification of perturbations leads to superfast nonlinear
+saturation. We conclude that such superfast amplification and superfast
+nonlinear saturation of ever existing perturbations serve as the mechanism for
+the generation, development and persistence of fully developed turbulence.",1908.04838v1
+2019-08-13,TCAD model for TeraFET detectors operating in a large dynamic range,"We present technology computer-aided design (TCAD) models for AlGaAs/InGaAs
+and AlGaN/GaN and silicon TeraFETs, plasmonic field effect transistors (FETs),
+for terahertz (THz) detection validated over a wide dynamic range. The modeling
+results are in good agreement with the experimental data for the AlGaAs/InGaAs
+heterostructure FETs (HFETs) and, to the low end of the dynamic range, with the
+analytical theory of the TeraFET detectors. The models incorporate the response
+saturation effect at high intensities of the THz radiation observed in
+experiments and reveal the physics of the response saturation associated with
+different mechanisms for different material systems. These mechanisms include
+the gate leakage, the velocity saturation and the avalanche effect.",1908.04845v1
+2019-08-17,"Enhanced stability, bistability, and exceptional points in saturable active photonic couplers","A generic photonic coupler with active and lossy parts, gain saturation and
+asymmetric characteristics is examined. Saturable activity is shown to be able
+to enhance the overall stability of the steady states, prevent evolution to
+undesirable unbounded modes and allow for bistable operation in specific
+regions of parametric space. Both stability and bistability are studied in the
+phase space of the system, where the basins of attraction of each state are
+identified, providing an accurate description of the dependence of the electric
+fields on the initial conditions. Continuous families of exceptional points are
+detected via suitable regulation of the coupling and asymmetry features of the
+configuration. In this way, a complete description of the nonlinear dynamics
+landscape is provided, which should be crucial for multiple application-driven
+designs incorporating such a ubiquitous optical component.",1908.06304v1
+2019-10-10,Stochastic DC Optimal Power Flow With Reserve Saturation,"We propose an optimization framework for stochastic optimal power flow with
+uncertain loads and renewable generator capacity. Our model follows previous
+work in assuming that generator outputs respond to load imbalances according to
+an affine control policy, but introduces a model of saturation of generator
+reserves by assuming that when a generator's target level hits its limit, it
+abandons the affine policy and produces at that limit. This is a particularly
+interesting feature in models where wind power plants, which have uncertain
+upper generation limits, are scheduled to provide reserves to balance load
+fluctuations. The resulting model is a nonsmooth nonconvex two-stage stochastic
+program, and we use a stochastic approximation method to find stationary
+solutions to a smooth approximation. Computational results on 6-bus and 118-bus
+test instances demonstrates that by considering the effects of saturation, our
+model can yield solutions with lower expected generation costs (at the same
+target line violation probability level) than those obtained from a model that
+enforces the affine policy to stay within generator limits with high
+probability.",1910.04667v1
+2019-10-21,Contextual Prediction Difference Analysis for Explaining Individual Image Classifications,"Much effort has been devoted to understanding the decisions of deep neural
+networks in recent years. A number of model-aware saliency methods were
+proposed to explain individual classification decisions by creating saliency
+maps. However, they are not applicable when the parameters and the gradients of
+the underlying models are unavailable. Recently, model-agnostic methods have
+also received attention. As one of them, \textit{Prediction Difference
+Analysis} (PDA), a probabilistic sound methodology, was proposed. In this work,
+we first show that PDA can suffer from saturated classifiers. The saturation
+phenomenon of classifiers exists widely in current neural network-based
+classifiers. To explain the decisions of saturated classifiers better, we
+further propose Contextual PDA, which runs hundreds of times faster than PDA.
+The experiments show the superiority of our method by explaining image
+classifications of the state-of-the-art deep convolutional neural networks.",1910.09086v2
+2019-10-22,Improving the Gating Mechanism of Recurrent Neural Networks,"Gating mechanisms are widely used in neural network models, where they allow
+gradients to backpropagate more easily through depth or time. However, their
+saturation property introduces problems of its own. For example, in recurrent
+models these gates need to have outputs near 1 to propagate information over
+long time-delays, which requires them to operate in their saturation regime and
+hinders gradient-based learning of the gate mechanism. We address this problem
+by deriving two synergistic modifications to the standard gating mechanism that
+are easy to implement, introduce no additional hyperparameters, and improve
+learnability of the gates when they are close to saturation. We show how these
+changes are related to and improve on alternative recently proposed gating
+mechanisms such as chrono initialization and Ordered Neurons. Empirically, our
+simple gating mechanisms robustly improve the performance of recurrent models
+on a range of applications, including synthetic memorization tasks, sequential
+image classification, language modeling, and reinforcement learning,
+particularly when long-term dependencies are involved.",1910.09890v2
+2019-11-06,From Parton Saturation to Proton Spin: the Impact of BFKL Equation and Reggeon Evolution,"Lev Lipatov was a giant in the field of strong interactions and a dominant
+force in high-energy QCD for many decades. His work deeply influenced both how
+we think about QCD and how we perform calculations in the theory. Below we
+describe the work in two related research directions: the physics of parton
+saturation and proton spin at small $x$. Both developments would have been
+impossible without Lipatov's groundbreaking work. Saturation physics would not
+have happened without the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation. The
+recent progress in our theoretical understanding of the proton spin
+contribution coming from small-$x$ partons started with the seminal paper by
+Kirschner and Lipatov resumming double logarithms of energy in the Reggeon
+evolution.",1911.02651v1
+2019-12-19,Nuclear and neutron-star matter from local chiral interactions,"We report a quantum Monte Carlo calculation of the equation of state of
+symmetric nuclear matter using local interactions derived from chiral effective
+field theory up to next-to-next-to-leading order fit to few-body observables
+only. The empirical saturation density and energy are well reproduced within
+statistical and systematic uncertainties. We have also derived the symmetry
+energy as a function of the density, finding good agreement with available
+experimentally derived constraints at saturation and twice saturation density.
+We find that the corresponding pressure is also in excellent agreement with
+recent constraints extracted from gravitational waves of the neutron-star
+merger GW170817 by the LIGO-Virgo detection.",1912.09411v2
+2019-12-23,Empirical constraints on the high-density equation of state from multi-messenger observables,"We search for possible correlations between neutron star observables and
+thermodynamic quantities that characterize high density nuclear matter. We
+generate a set of model-independent equations of state describing stellar
+matter from a Taylor expansion around saturation density. Each equation of
+state which is a functional of the nuclear matter parameters is
+thermodynamically consistent, causal and compatible with astrophysical
+observations. We find that the neutron star tidal deformability and radius are
+strongly correlated with the pressure, the energy density and the sound
+velocity at different densities. Similar correlations are also exhibited by a
+large set of mean-field models based on non-relativistic and relativistic
+nuclear energy density functionals. These model independent correlations can be
+employed to constrain the equation of state at different densities above
+saturation from measurements of NS properties with multi-messenger
+observations. In particular, precise constraints on the radius of PSR
+J0030+0451 thanks to NICER observations would allow to better infer the
+properties of matter around two times the nuclear saturation density.",1912.11131v1
+2019-12-31,A new physics-preserving IMPES scheme for incompressible and immiscible two-phase flow in heterogeneous porous media,"In this work we consider a new efficient IMplicit Pressure Explicit
+Saturation (IMPES) scheme for the simulation of incompressible and immiscible
+two-phase flow in heterogeneous porous media with capillary pressure. Compared
+with the conventional IMPES schemes, the new IMPES scheme is inherently
+physics-preserving, namely, the new algorithm is locally mass conservative for
+both phases and it also enjoys another appealing feature that the total
+velocity is continuous in the normal direction. Moreover, the new scheme is
+unbiased with regard to the two phases and the saturations of both phases are
+bounds-preserving if the time step size is smaller than a certain value. The
+key ideas in the new scheme include that the Darcy flows for both phases are
+rewritten in the formulation based on the total velocity and an auxiliary
+velocity referring to as the capillary potential gradient, and the total
+discretized conservation equation is obtained by the summation of the
+discretized conservation equation for each phase. The upwind strategy is
+applied to update the saturations explicitly, and the upwind mixed finite
+element methods are used to solve the pressure-velocity systems which can be
+decoupled. We also present some interesting examples to demonstrate the
+efficiency and robustness of the new algorithm.",1912.13340v1
+2020-01-16,"Slow-to-Start Traffic Model: Condensation, Saturation and Scaling Limits","We consider a one-dimensional traffic model with a slow-to-start rule. The
+initial position of the cars in $\mathbb R$ is a Poisson process of parameter
+$\lambda$. Cars have speed 0 or 1 and travel in the same direction. At time
+zero the speed of all cars is 0; each car waits an exponential time to switch
+speed from $0$ to $1$ and stops when it collides with a stopped car. When the
+car is no longer blocked, it waits a new exponential time to assume speed one,
+and so on. We study the emergence of condensation for the saturated regime
+$\lambda>1$ and the critical regime $\lambda=1$, showing that in both regimes
+all cars collide infinitely often and each car has asymptotic mean velocity
+$1/\lambda$. In the saturated regime the moving cars form a point process whose
+intensity tends to 1. The remaining cars condensate in a set of points whose
+intensity tends to zero as $1/\sqrt t$. We study the scaling limit of the
+traffic jam evolution in terms of a collection of coalescing Brownian motions.",2001.05796v1
+2020-02-11,Maser Flares Driven by Variations in Pumping and Background Radiation,"We simulate maser flares by varying either the pump rate or the background
+level of radiation in a 3D model of a maser cloud. We investigate the effect of
+different cloud shapes, saturation levels and viewpoints. Results are
+considered for clouds with both uniform and internally variable unsaturated
+inversion. Pumping and background variations are represented by several
+different driving functions, some of which are light curves drawn from
+observations. We summarise the pumping variability results in terms of three
+observable parameters, the maximum flux density achieved, a variability index
+and duty cycle. We demonstrate typical ranges of the flux density that may
+result from viewing an aspherical object from random viewpoints. The best
+object for a flare is a prolate cloud, viewed close to its long axis and driven
+from unsaturated conditions to at least modest saturation. Results for
+variation of the background level are qualitatively different from the variable
+pumping results in that they tend to produce short intervals of low flux
+density under conditions of moderate saturation and sufficient variability to
+be consistent with strong flaring. Variable background models typically have a
+significantly higher duty cycle than those with variable pumping.",2002.04490v1
+2020-02-11,Soft diffraction within the QCD color dipole picture,"In this work we consider the QCD parton saturation models to describe soft
+interactions at the high energy limit. The total and elastic cross sections as
+well as the elastic slope parameter are obtained for proton-proton and
+pion-proton collisions and compared to recent experimental results. The
+analyses are done within the color dipole formalism taking into account
+saturation models which have been tested against DIS data. The main point is
+that the match between soft and hard interaction occurs in the saturation
+region which can be described by high density QCD approaches. Discussion is
+performed on the main theoretical uncertainties associated with calculations.",2002.04586v2
+2020-03-03,Saturation for the Butterfly Poset,"Given a finite poset $\mathcal P$, we call a family $\mathcal F$ of subsets
+of $[n]$ $\mathcal P$-saturated if $\mathcal F$ does not contain an induced
+copy of $\mathcal P$, but adding any other set to $\mathcal F$ creates an
+induced copy of $\mathcal P$. The induced saturated number of $\mathcal P$,
+denoted by $\text{sat}^*(n,\mathcal P)$, is the size of the smallest $\mathcal
+P$-saturated family with ground set $[n]$. In this paper we are mainly
+interested in the four-point poset called the butterfly. Ferrara, Kay, Kramer,
+Martin, Reiniger, Smith and Sullivan showed that the saturation number for the
+butterfly lies between $\log_2{n}$ and $n^2$. We give a linear lower bound of
+$n+1$. We also prove some other results about the butterfly and the poset
+$\mathcal N$.",2003.01621v1
+2020-04-08,"The COVID-19 pandemic: growth patterns, power law scaling, and saturation","More and more countries show a significant slowdown in the number of new
+COVID-19 infections due to effective governmentally instituted lockdown and
+social distancing measures. We have analyzed the growth behavior of the top 25
+most affected countries by means of a local slope analysis and found three
+distinct patterns that individual countries follow depending on the strictness
+of the lockdown protocols: exponential rise and fall, power law, or logistic.
+For countries showing power law growth we have determined the scaling
+exponents. For countries that showed a strong slowdown in the rate of
+infections we have extrapolated the expected saturation of the number of
+infections and the expected final date. Two different extrapolation methods
+(logistic and parabolic) were used. Both methods agree on the order of
+magnitude of saturation and end dates. Global infections rates are analyzed
+with the same methods. The relevance and accuracy of these extrapolations is
+discussed.",2004.03859v1
+2020-04-16,Self-acceleration and energy channeling in the saturation of the ion-sound instability in a bounded plasma,"A novel regime of the saturation of the Pierce-type ion-sound instability in
+bounded ion-beam-plasma system is revealed in 1D PIC simulations. It is found
+that the saturation of the instability is mediated by the oscillating virtual
+anode potential structure. The periodically oscillating potential barrier
+separates the incoming beam ions into two groups. One component forms a
+supersonic beam which is accelerated to an energy exceeding the energy of the
+initial cold ion beam. The other component is organized as a self-consistent
+phase space structure of trapped ions with a wide energy spread - the ion hole.
+The effective temperature (energy spread) of the ions trapped in the hole is
+lower than the initial beam energy. In the final stage the ion hole expands
+over the whole system length.",2004.07513v1
+2020-05-05,Exploring the relationship between nuclear matter and finite nuclei with chiral two- and three-nucleon forces,"We address the connection between the saturating behavior of infinite nuclear
+matter and the description of finite nuclei based on state-of-the-art chiral
+two- and three-nucleon forces. We observe that chiral two- and three-nucleon
+interactions (at N2LO and at N3LO) which have been found to predict realistic
+binding energies and radii for a wide range of finite nuclei (from p-shell
+nuclei up to nickel isotopes) are unable to saturate infinite nuclear matter.
+On the other hand, it has been shown that, when the fits of the cD and cE
+couplings of the chiral three-nucleon interactions include the constraint of
+nuclear matter saturation in addition to, as is typically the case, the triton
+binding energy, medium-mass nuclei are underbound and their radii are
+sytematically too large. We discuss this apparent inconsistency and perform
+test calculations for various scenarios to shed light on the issue.",2005.01958v2
+2020-05-14,The diffractive saturable loss mechanism in Kerr-lens mode-locked lasers: direct observation and simulation,"Passive mode-locking critically relies on a saturable loss mechanism to form
+ultrashort pulses. However, in Kerr-lens mode-locking (KLM), no actual
+absorption takes place, but rather losses appear due to diffraction, and actual
+light must escape the cavity. The Kerr-lens effect works to generate through
+diffraction an effective instantaneous saturable absorber that delicately
+depends on the interplay between the spatial and temporal profiles of the
+pulse. Despite the importance of KLM as a technique for generating ultrafast
+pulses and the fundamental role of the diffraction losses in its operation,
+these losses were never directly observed. Here, we measure the light that
+leaks out due to diffraction losses in a hard-aperture Kerr-lens mode-locked
+Ti:Sapphire laser, and compare the measured results with a numerical theory
+that explicitly calculates the spatio-temporal behavior of the pulse.",2005.06937v3
+2020-06-11,Wave-particle interactions in a long traveling wave tube with upgraded helix,"We investigate the interaction of electromagnetic waves and electron beams in
+a 4 meters long traveling wave tube (TWT). The device is specially designed to
+simulate beam-plasma experiments without appreciable noise. This TWT presents
+an upgraded slow wave structure (SWS) that results in more precise measurements
+and makes new experiments possible. We introduce a theoretical model describing
+wave propagation through the SWS and validated by the experimental dispersion
+relation, impedance, phase and group velocities. We analyze nonlinear effects
+arising from the beam-wave interaction, such as the modulation of the electron
+beam and the wave growth and saturation process. When the beam current is low,
+the wave growth coefficient and saturation amplitude follow the linear theory
+predictions. However, for high values of current, nonlinear space charge
+effects become important and these parameters deviate from the linear
+predictions, tending to a constant value. After saturation, we also observe
+trapping of the beam electrons, which alters the wave amplitude along the TWT.",2006.06710v2
+2020-06-21,An Entropy-based Proof of Threshold Saturation for Nonbinary SC-LDPC Ensembles on the BEC,"In this paper we are concerned with the asymptotic analysis of nonbinary
+spatially-coupled low-density parity-check (SC-LDPC) ensembles defined over
+GL$\left(2^{m}\right)$ (the general linear group of degree $m$ over
+GF$\left(2\right)$). Our purpose is to prove threshold saturation when the
+transmission takes place on the binary erasure channel (BEC). To this end, we
+establish the duality rule for entropy for nonbinary variable-node (VN) and
+check-node (CN) convolutional operators to accommodate the nonbinary density
+evolution (DE) analysis. Based on this, we construct the explicit forms of the
+potential functions for uncoupled and coupled DE recursions. In addition, we
+show that these functions exhibit similar monotonicity properties as those for
+binary LDPC and SC-LDPC ensembles over general binary memoryless symmetric
+(BMS) channels. This leads to the threshold saturation theorem and its converse
+for nonbinary SC-LDPC ensembles on the BEC, following the proof technique
+developed by S. Kumar et al.",2006.11740v1
+2020-06-22,Capillary transport in paper porous materials at low saturation levels,"The problem of capillary transport in fibrous porous materials at low levels
+of liquid saturation has been addressed. It has been demonstrated, that the
+process of liquid spreading in this type of porous materials at low saturation
+can be described macroscopically by a similar super-fast, non-linear diffusion
+model as that, which had been previously identified in experiments and
+simulations in particulate porous media. The macroscopic diffusion model has
+been underpinned by simulations using a microscopic network model. The
+theoretical results have been qualitatively compared with available
+experimental observations using persistent liquids.",2006.12419v1
+2020-06-28,Resonant forward-scattered field in the high-saturation regime: Elastic and inelastic contributions,"We measure the resonant forward scattering of light by a highly saturated
+atomic medium through the flashes emitted immediately after an abrupt
+extinction of the probe beam. The experiment is done in a dilute regime where
+the phenomena are well captured using the independent scattering approximation.
+Comparing our measurements to a model based on Maxwell-Bloch equations, our
+experimental results are consistent with contributions from only the elastic
+component, whereas the attenuation of the coherent transmission power is linked
+to the elastic and inelastic scatterings. In the large saturation regime and at
+the vicinity of the atomic resonance, we derive an asymptotic expression
+relating the elastic scattering power to the forward-scattered power.",2006.15540v2
+2020-07-14,Insights into nuclear saturation density from parity violating electron scattering,"The saturation density of nuclear matter $\rho_0$ is a fundamental nuclear
+physics property that is difficult to predict from fundamental principles. The
+saturation density is closely related to the interior density of a heavy
+nucleus, such as $^{208}$Pb. We use parity violating electron scattering to
+determine the average interior weak charge and baryon densities in $^{208}$Pb.
+This requires not only measuring the weak radius $R_{\rm wk}$ but also
+determining the surface thickness of the weak charge density $a$. We obtain
+$\rho_0=0.150\pm0.010$ fm$^{-3}$, where the 7\% error has contributions form
+the PREX error on the weak radius, an assumed 10\% uncertainty in the surface
+thickness $a$, and from the extrapolation to infinite nuclear matter. These
+errors can be improved with the upcoming PREX II results and with a new parity
+violating electron scattering experiment, at a somewhat higher momentum
+transfer, to determine $a$.",2007.07117v2
+2020-07-15,A Graph Theoretic Approach to Power System Vulnerability Identification,"During major power system disturbances, when multiple component outages occur
+in rapid succession, it becomes crucial to quickly identify the transmission
+interconnections that have limited power transfer capability. Understanding the
+impact of an outage on these critical interconnections (called saturated
+cut-sets) is important for enhancing situational awareness and taking correct
+actions. This paper proposes a new graph theoretic approach for analyzing
+whether a contingency will create a saturated cut-set in a meshed power
+network. A novel feature of the proposed algorithm is that it lowers the
+solution time significantly making the approach viable for real-time
+operations. It also indicates the minimum amount by which the power transfer
+through the critical interconnections should be reduced so that
+post-contingency saturation does not occur. Robustness of the proposed
+algorithm for enhanced situational awareness is demonstrated using the IEEE-118
+bus system as well as a 17,000+ bus model of the Western Interconnection (WI).
+Comparisons made with different approaches for power system vulnerability
+assessment prove the utility of the proposed scheme for aiding power system
+operations during extreme exigencies.",2007.07859v1
+2020-07-24,All-fiber mode-locked ytterbium-doped fiber laser with a saturable absorber based on nonlinear Kerr beam cleanup effect,"We theoretically and experimentally demonstrate a novel mode-locked
+ytterbium-doped fiber laser with a saturable absorber based on nonlinear Kerr
+beam cleanup effect. The saturable absorber was formed by a 2-m graded-index
+multimode fiber and a single-mode fiber segment served as a diaphragm. With an
+all-normal-dispersion-fiber configuration, the laser generated dissipative
+soliton pulses with pulse duration of 26.38 ps and pulse energy more than 0.25
+nJ; output pulses could be compressed externally to 615.7 fs. Moreover, the
+self-starting mode-locking operation of this laser exhibited a high stability
+with a measured signal-to-noise ratio of 73.4 dB in the RF spectrum.",2007.12334v2
+2020-07-27,Is there slow particle transport in the MBL phase?,"We analyze the saturation value of the bipartite entanglement and number
+entropy starting from a random product state deep in the MBL phase. By studying
+the probability distributions of these entropies we find that the growth of the
+saturation value of the entanglement entropy stems from a significant
+reshuffling of the weight in the probability distributions from the bulk to the
+exponential tails. In contrast, the probability distributions of the saturation
+value of the number entropy are converged with system size, and exhibit a sharp
+cut-off for values of the number entropy which correspond to one particle
+fluctuating across the boundary between the two halves of the system. Our
+results therefore rule out slow particle transport deep in the MBL phase and
+confirm that the slow entanglement entropy production stems uniquely from
+configurational entanglement.",2007.13767v1
+2020-08-07,Robust photon transmission in nonlinear parity-time-symmetric cavities,"We explore the photon transfer in the nonlinear parity-time-symmetry system
+of two coupled cavities, which contains nonlinear gain and loss dependent on
+the intracavity photons. Analytical solution to the steady state gives a
+saturated gain, which satisfy the parity-time symmetry automatically. The
+eigen-frequency self-adapts the nonlinear saturated gain to reach the maximum
+efficiency in the steady state. We find that the saturated gain in the weak
+coupling regime does not match the loss in the steady state, exhibiting an
+appearance of a spontaneous symmetry-breaking. The photon transmission
+efficiency in the parity-time-symmetric regime is robust against the variation
+of the coupling strength, which improves the results of the conventional
+methods by tuning the frequency or the coupling strength to maintain optimal
+efficiency. Our scheme provides an experimental platform for realizing the
+robust photon transfer in cavities with nonlinear parity-time symmetry.",2008.02949v1
+2020-08-13,Resistivity saturation in Kondo insulators,"Resistivities of heavy-fermion insulators typically saturate below a
+characteristic temperature $T^*$. For some, metallic surface states,
+potentially from a non-trivial bulk topology, are a likely source of residual
+conduction. Here, we establish an alternative mechanism: At low temperature, in
+addition to the charge gap, the scattering rate turns into a relevant energy
+scale, invalidating the semiclassical Boltzmann picture. Finite lifetimes of
+intrinsic carriers limit conduction, impose the existence of a crossover $T^*$,
+and control - now on par with the gap - the quantum regime emerging below it.
+We showcase the mechanism with realistic many-body simulations and elucidate
+how the saturation regime of the Kondo insulator Ce$_3$Bi$_4$Pt$_3$, for which
+residual conduction is a bulk property, evolves under external pressure and
+varying disorder. Using a phenomenological formula we derived for the quantum
+regime, we also unriddle the ill-understood bulk conductivity of SmB$_6$ -
+demonstrating that our mechanism is widely applicable to correlated narrow-gap
+semiconductors.",2008.05846v1
+2020-08-21,Vacuum-Induced Saturation in Plasmonic Nanoparticles,"Vacuum fluctuations are a fundamental feature of quantized fields. It is
+usually assumed that observations connected to vacuum fluctuations require a
+system well isolated from other influences. In this work, we demonstrate that
+effects of the quantum vacuum can already occur in simple colloidal
+nano-assemblies prepared by wet chemistry. We claim that the electromagnetic
+field fluctuations at the zero-point level saturate the absorption of dye
+molecules self-assembled at the surface of plasmonic nano-resonators. For this
+effect to occur, reaching the strong coupling regime between the plasmons and
+excitons is not required. This intriguing effect of vacuum-induced saturation
+(VISA) is discussed within a simple quantum optics picture and demonstrated by
+comparing the optical spectra of hybrid gold-core dye-shell nanorods to
+electromagnetic simulations.",2008.09395v1
+2020-09-04,First-principles study of ultrafast and nonlinear optical properties of graphite thin films,"We theoretically investigate ultrafast and nonlinear optical properties of
+graphite thin films based on first-principles time-dependent density functional
+theory. We first calculate electron dynamics in a unit cell of graphite under a
+strong pulsed electric field and explore the transient optical properties of
+graphite. It is shown that the optical response of graphite shows a sudden
+change from conducting to insulating phase at a certain intensity range of the
+applied electric field. It also appears as a saturable absorption, the
+saturation in the energy transfer from the electric field to electrons. We next
+investigate a light propagation in graphite thin films by solving coupled
+dynamics of the electrons and the electromagnetic fields simultaneously. It is
+observed that the saturable absorption manifests in the propagation with small
+attenuation in the spatial region where the electric field amplitude is about
+$4 \sim 7 \times 10^{-2}$ V/Angstrom.",2009.01979v2
+2020-09-25,Fundamental limitations to no-jerk gearshifts of multi-speed transmission architectures in electric vehicles,"Multi-speed transmissions can enhance the performance and reduce the overall
+cost of an electric vehicle, but they also introduce a challenge: avoiding
+gearshift jerk, which may sometimes prove to be impossible in the presence of
+motor and clutch saturation. In this article, we introduce three theorems that
+explicitly define the fundamental limitations to no-jerk gearshifts resulting
+from motor or actuator saturation. We compare gearshifts that consist of
+transferring transmission torque from one friction clutch to another, to the
+case in which one of the clutches is a one-way clutch. We show that systems
+with a one-way clutch are more prone to motor saturation, causing gearshift
+jerk to be more often inevitable. We also study the influence of planetary
+gearsets on the gearshift dynamical trajectories, and expose the impact on the
+no-jerk limitations. This work offers tools to compare transmission
+architectures during the conceptual design phase of a new electric vehicle.",2009.12410v2
+2020-09-28,Pulse-duration dependence of saturable and reverse saturable absorption in ZnCo2O4 microflowers,"We employed open-aperture Z-scan technique to unveil the third-order optical
+nonlinearity in ZnCo2O4 (ZCO) microflowers. Our results indicate that
+intersystem crossing (ISC) lifetime can be used as simple tool to demonstrate
+remarkably contrasting optical nonlinearity in ZCO. Ultrafast transient
+absorption measurements reveal that ISC from singlet to triplet state takes
+place in 5 ps. For femtosecond laser pulses, when the pulse duration is shorter
+than ISC lifetime, saturable absorption (SA) takes place for all intensities.
+On the contrary, when the pulse duration is longer than ISC for nanosecond
+excitation, we observe transition from SA to reverse SA (RSA) at higher
+intensities via excited-state absorption. We envisage that benefiting from SA
+and RSA, ZCO emerges as potential candidate for mode locking and optical
+limiting devices.",2009.13226v2
+2020-10-15,Experimental vulnerability analysis of QKD based on attack ratings,"Inspired by the methodology used for classical cryptographic hardware, we
+consider the use of attack ratings in the context of QKD security evaluation.
+To illustrate the relevance of this approach, we conduct an experimental
+vulnerability assessment of CV-QKD against saturation attacks, for two
+different attack strategies. The first strategy relies on inducing detector
+saturation by performing a large coherent displacement. This strategy is
+experimentally challenging and therefore translates into a high attack rating.
+We also propose and experimentally demonstrate a second attack strategy that
+simply consists in saturating the detector with an external laser. The low
+rating we obtain indicates that this attack constitutes a primary threat for
+practical CV-QKD systems. These results highlight the benefits of combining
+theoretical security considerations with vulnerability analysis based on attack
+ratings, in order to guide the design and engineering of practical QKD systems
+towards the highest possible security standards.",2010.07815v2
+2020-10-15,Non-saturating GAN training as divergence minimization,"Non-saturating generative adversarial network (GAN) training is widely used
+and has continued to obtain groundbreaking results. However so far this
+approach has lacked strong theoretical justification, in contrast to
+alternatives such as f-GANs and Wasserstein GANs which are motivated in terms
+of approximate divergence minimization. In this paper we show that
+non-saturating GAN training does in fact approximately minimize a particular
+f-divergence. We develop general theoretical tools to compare and classify
+f-divergences and use these to show that the new f-divergence is qualitatively
+similar to reverse KL. These results help to explain the high sample quality
+but poor diversity often observed empirically when using this scheme.",2010.08029v1
+2020-10-21,On the Saturation Phenomenon of Stochastic Gradient Descent for Linear Inverse Problems,"Stochastic gradient descent (SGD) is a promising method for solving
+large-scale inverse problems, due to its excellent scalability with respect to
+data size. The current mathematical theory in the lens of regularization theory
+predicts that SGD with a polynomially decaying stepsize schedule may suffer
+from an undesirable saturation phenomenon, i.e., the convergence rate does not
+further improve with the solution regularity index when it is beyond a certain
+range. In this work, we present a refined convergence rate analysis of SGD, and
+prove that saturation actually does not occur if the initial stepsize of the
+schedule is sufficiently small. Several numerical experiments are provided to
+complement the analysis.",2010.10916v2
+2020-10-21,"Painting with Hue, Saturation, and Brightness Control by Nanoscale 3D Printing","Varying only the in-plane or out-of-plane dimensions of nanostructures
+produces a wide range of colourful elements in metasurfaces and thin films.
+However, achieving shades of grey and control of colour saturation remains
+challenging. Here, we introduce a hybrid approach to colour generation based on
+the tuning of nanostructure geometry in all three dimensions. Through
+two-photon polymerization lithography, we systematically investigated colour
+generation from the simple single nanopillar geometry made of
+low-refractive-index material; realizing grayscale and full colour palettes
+with control of hue, saturation, brightness through tuning of height, diameter,
+and periodicity of nanopillars. Arbitrary colourful and grayscale images were
+painted by mapping desired prints to precisely controllable parameters during
+3D printing. We extend our understanding of the scattering properties of the
+low-refractive-index nanopillar to demonstrate grayscale inversion and colour
+desaturation, with steganography at the level of single nanopillars.",2010.11035v2
+2020-12-18,Moments and saturation properties of eigenstates,"Eigenvalues are defined for any element of an algebra of observables and do
+not require a representation in terms of wave functions or density matrices. A
+systematic algebraic derivation based on moments is presented here for the
+harmonic oscillator, together with a perturbative treatment of anharmonic
+systems. In this process, a collection of inequalities is uncovered which
+amount to uncertainty relations for higher-order moments saturated by the
+harmonic-oscillator excited states. Similar saturation properties hold for
+anharmonic systems order by order in perturbation theory. The new method, based
+on recurrence relations for moments of a state combined with positivity
+conditions, is therefore able to show new physical features.",2012.10321v1
+2020-12-21,Hybrid Beamforming for Millimeter Wave Full-Duplex under Limited Receive Dynamic Range,"Full-duplex millimeter wave (mmWave) communication has shown increasing
+promise for self-interference cancellation via hybrid precoding and combining.
+This paper proposes a novel mmWave multiple-input multiple-output (MIMO) design
+for configuring the analog and digital beamformers of a full-duplex
+transceiver. Our design is the first to holistically consider the key practical
+constraints of analog beamforming codebooks, a minimal number of radio
+frequency (RF) chains, limited channel knowledge, beam alignment, and a limited
+receive dynamic range. To prevent self-interference from saturating the
+receiver of a full-duplex device having limited dynamic range, our design
+addresses saturation on a per-antenna and per-RF chain basis. Numerical results
+evaluate our design in a variety of settings and validate the need to prevent
+receiver-side saturation. These results and the corresponding insights serve as
+useful design references for practical full-duplex mmWave transceivers.",2012.11647v1
+2021-01-06,Modelling wave dispersion in fluid saturating periodic scaffolds,"Acoustic waves in a slightly compressible fluid saturating porous periodic
+structure are studied using two complementary approaches: 1) the periodic
+homogenization (PH) method provides effective model equations for a general
+dynamic problem imposed in a bounded medium, 2) harmonic acoustic waves are
+studied in an infinite medium using the Floquet-Bloch (FB) wave decomposition.
+  In contrast with usual simplifications, the advection phenomenon of the
+Navier-Stokes equations is accounted for. For this, an acoustic approximation
+is applied to linearize the advection term. The homogenization results are
+based the periodic unfolding method combined with the asymptotic expansion
+technique providing a straight upscaling procedure which leads to the
+macroscopic model defined in terms of the effective model parameters. These are
+computed using the characteristic responses of the porous microstructure.
+  Using the FB theory, we derive dispersion equations for the scaffolds
+saturated by the inviscid, or the viscous, barotropic fluids, whereby the
+advection due to a permanent flow in the porous structures is respected. A
+computational study is performed for the numerical models obtained using the
+finite element discretization. For the FB methods-based dispersion analysis,
+quadratic eigenvalue problems must be solved. The numerical examples show
+influences of the microstructure size and of the advection generating an
+anisotropy of the acoustic waves dispersion.",2101.01969v1
+2021-01-25,Asymmetric Si-slot Coupler with Nonreciprocal Response Based on Graphene Saturable Absorption,"We present the study of a proof-of-concept integrated device that can be used
+as a nonlinear broadband isolator. The device is based on the asymmetric
+loading of a highly-confining silicon-slot photonic coupler with graphene
+layers, whose ultrafast and low-threshold saturable absorption can be exploited
+for nonreciprocal transmission between the cross-ports of the coupler. The
+structure is essentially a non-Hermitian system, whose exceptional points are
+briefly discussed. The nonlinear device is modeled with a coupled Schrodinger
+equation system whose validity is checked by full-vector finite element-based
+beam-propagation method simulations in CW. The numerically computed performance
+reveals a nonreciprocal intensity range (NRIR) in the vicinity of 100 mW peak
+power with a bandwidth spanning tens of nanometers, from CW down to ps-long
+pulses. Finally, the combination of saturable absorption and self-phase
+modulation (Kerr effect) in graphene is studied, indicating the existence of
+two NRIR with opposite directionality.",2101.10210v2
+2021-01-27,Maximizing performance of quantum cascade laser-pumped molecular lasers,"Quantum cascade laser (QCL)-pumped molecular lasers (QPMLs) have recently
+been introduced as a new source of powerful (>1 mW), tunable (>1 THz),
+narrow-band (<10 kHz), continuous-wave terahertz radiation. The performance of
+these lasers depends critically on molecular collision physics, pump
+saturation, and on the design of the laser cavity. Using a validated
+three-level model that captures the essential collision and saturation
+behaviors of the QPML gas nitrous oxide (N2O),we explore how threshold pump
+power and output terahertz power depend on pump power, gas pressure, as well as
+on the diameter, length, and output-coupler transmissivity of a cylindrical
+cavity.The analysis indicates that maximum power occurs as pump saturation is
+minimized in a manner that depends much more sensitively on pressure than on
+cell diameter, length, or transmissivity. A near-optimal compact laser cavity
+can produce more than 10 mW of power tunable over frequencies above 1 THz when
+pumped by a multi-watt QCL.",2101.11158v2
+2021-02-14,Modeling Electrical Resistance Drift with Ultrafast Saturation of OTS Selectors,"Crossbar array architecture is an essential design element for densely
+connected Non-Volatile Memory(NVM) applications. To overcome intrinsic sneak
+current problem of crossbar arrays, each memory unit is serially attached to a
+selector unit with highly nonlinear current-voltage (I-V) characteristics.
+Recently, Ovonic Threshold Switching (OTS) materials are preferred as selectors
+due to their fabrication compatibility with PRAM, MRAM or ReRAM technologies;
+however, OTS selectors suffer from the temporal drift of its threshold voltage.
+First, based on Poole-Frenkel conduction, we present time and temperature
+dependent model that predicts temporally evolving I-V characteristics,including
+threshold voltage of OTS selectors. Second, we report an ultrafast saturation
+($\sim 10^3$ seconds) of the drift and extend the model to predict the time of
+drift saturation. Our model shows excellent agreement with OTS devices
+fabricated with 8 nm technology node at 25{\deg}C and 85{\deg}C ambient
+temperatures. The proposed model plays a significant role in understanding OTS
+device internals and the development of reliable threshold voltage jump table.",2102.07264v1
+2021-02-16,Realizability and tameness of fusion systems,"A saturated fusion system over a finite $p$-group $S$ is a category whose
+objects are the subgroups of $S$ and whose morphisms are injective
+homomorphisms between the subgroups satisfying certain axioms. A fusion system
+over $S$ is realized by a finite group $G$ if $S$ is a Sylow $p$-subgroup of
+$G$ and morphisms in the category are those induced by conjugation in $G$. One
+recurrent question in this subject is to find criteria as to whether a given
+saturated fusion system is realizable or not.
+  One main result in this paper is that a saturated fusion system is realizable
+if all of its components (in the sense of Aschbacher) are realizable. Another
+result is that all realizable fusion systems are tame: a finer condition on
+realizable fusion systems that involves describing automorphisms of a fusion
+system in terms of those of some group that realizes it. Stated in this way,
+these results depend on the classification of finite simple groups, but we also
+give more precise formulations whose proof is independent of the
+classification.",2102.08278v4
+2021-03-15,On saturation of Berge hypergraphs,"A hypergraph $H=(V(H), E(H))$ is a Berge copy of a graph $F$, if $V(F)\subset
+V(H)$ and there is a bijection $f:E(F)\rightarrow E(H)$ such that for any $e\in
+E(F)$ we have $e\subset f(e)$. A hypergraph is Berge-$F$-free if it does not
+contain any Berge copies of $F$. We address the saturation problem concerning
+Berge-$F$-free hypergraphs, i.e., what is the minimum number $sat_r(n,F)$ of
+hyperedges in an $r$-uniform Berge-$F$-free hypergraph $H$ with the property
+that adding any new hyperedge to $H$ creates a Berge copy of $F$. We prove that
+$sat_r(n,F)$ grows linearly in $n$ if $F$ is either complete multipartite or it
+possesses the following property: if $d_1\le d_2\le \dots \le d_{|V(F)|}$ is
+the degree sequence of $F$, then $F$ contains two adjacent vertices $u,v$ with
+$d_F(u)=d_1$, $d_F(v)=d_2$. In particular, the Berge-saturation number of
+regular graphs grows linearly in $n$.",2103.08437v1
+2021-03-28,Fixed points theorems for unsaturated and saturated classes of contractive mappings in Banach spaces,"Based on the technique of enriching contractive type mappings, a technique
+that has been used successfully in some recent papers, we introduce the concept
+of {\it saturated} class of contractive mappings. We show that, from this
+perspective, the contractive type mappings in the metric fixed point theory can
+be separated into two distinct classes, unsaturated and saturated, and that,
+for any unsaturated class of mappings, the technique of enriching contractive
+type mappings provides genuine new fixed point results. We illustrate the
+concept by surveying some significant fixed point results obtained recently for
+five remarkable unsaturated classes of contractive mappings. In the second part
+of the paper, we also identify some classes of saturated classes of contractive
+mappings, whose main feature is that they cannot be enlarged by means of the
+technique of enriching the contractive mappings.",2103.15148v1
+2021-04-05,First Saturation Correction in High Energy Proton-Nucleus Collisions: II. Single Inclusive Semi-Hard Gluon Production,"Exploiting recently obtained analytic solutions of classical Yang-Mills
+equations for higher order perturbations in the field of the dilute object
+(proton), we derive the complete first saturation correction to the single
+inclusive semi-hard gluon production in high energy proton-nucleus collisions
+by applying the Lehmann-Symanzik-Zimmermann reduction formula. We thus finalize
+the program started by Balitsky (see Ref.~\cite{Balitsky:2004rr}) and
+independently by Chirilli, Kovchegov and Wertepny (see
+Ref.~\cite{Chirilli:2015tea}) albeit using a very different approach to carry
+out our calculations. We extracted the functional dependence of gluon spectrum
+on the color charge densities of the colliding objects; thus our results can be
+used to evaluate complete first saturation correction to the double/multiple
+inclusive gluon productions.",2104.01879v1
+2021-04-08,Landau Damping in the Transverse Modulational Dynamics of Co-Propagating Light and Matter Beams,"The optomechanical coupling and transverse stability of a co-propagating
+monochromatic electromagnetic wave and mono-energetic beam of two-level atoms
+is investigated in the collisionless regime. The coupled dynamics are studied
+through a Landau stability analysis of the coupled gas- kinetic and paraxial
+wave equations, including the effect of the electronic nonlinearity. The
+resulting dispersion relation captures the interaction of kinetic and
+saturation effects and shows that for blue detuning the combined nonlinear
+interaction is unstable below a critical wavenumber which reduces to the result
+of Bespalov and Talanov in the limit of a negligible kinetic nonlinearity. For
+red detuning we find that under a saturation parameter threshold exists whereby
+the system stabilizes unconditionally. With negligible saturation, an
+optomechanical form of Landau damping stabilizes all wavenumbers above a
+critical wavenumber determined by the combined strength of the kinetic and
+refractive optomechanical feedback. The damping is mediated primarily by atoms
+traveling along the primary diagonals of the Talbot carpet.",2104.04100v1
+2021-04-24,Optimizing Regular Expressions via Rewrite-Guided Synthesis,"Regular expressions are pervasive in modern systems. Many real-world regular
+expressions are inefficient, sometimes to the extent that they are vulnerable
+to complexity-based attacks, and while much research has focused on detecting
+inefficient regular expressions or accelerating regular expression matching at
+the hardware level, we investigate automatically transforming regular
+expressions to remove inefficiencies. We reduce this problem to general
+expression optimization, an important task necessary in a variety of domains
+even beyond compilers, e.g., digital logic design, etc. Syntax-guided synthesis
+(SyGuS) with a cost function can be used for this purpose, but ordered
+enumeration through a large space of candidate expressions can be prohibitively
+expensive. Equality saturation is an alternative approach which allows
+efficient construction and maintenance of expression equivalence classes
+generated by rewrite rules, but the procedure may not reach saturation, meaning
+global minimality cannot be confirmed. We present a new approach called
+rewrite-guided synthesis (ReGiS), in which a unique interplay between SyGuS and
+equality saturation-based rewriting helps to overcome these problems, resulting
+in an efficient, scalable framework for expression optimization.",2104.12039v3
+2021-05-19,Topological Insulators: An in-depth Review of their Use in Modelocked Fiber Lasers,"Topological Insulators (TIs) exhibit exciting optical properties, which opens
+up a new pathway to generate ultrashort pulses from fiber lasers. Layered TIs
+display distinct saturable absorption property due to excited state absorption,
+as compared to their bulk structures. Moreover, the electronic structures of
+the films of TIs depend on the thickness of the films due to the quantum
+confinement of the electrons. By virtue of this, the nanoparticles of TIs play
+a key role in all-fiber modelocked laser. By tweaking the crystal structures of
+TIs, it is possible to generate ultrashort pulses across the visible,
+near-infrared and mid-infrared wavelengths. Starting from the crystal
+structures and density of states calculations, how different topological
+insulators can be fabricated and integrated as an efficient passive saturable
+absorber in all-fiber modelocked lasers with the capability of producing
+fundamental to high-harmonic pulse generation are described clearly in this
+review report. Moreover, this report reviews the current state-of-art of
+TI-based saturable absorbers and their applications in different regimes of
+modelocked fiber lasers.",2105.09195v1
+2021-05-26,Moment-based superresolution: Formalism and applications,"Sensitivity limits are usually determined using the Cram\'er-Rao bound.
+Recently this approach has been used to obtain the ultimate resolution limit
+for the estimation of the separation between two incoherent point sources.
+However, methods that saturate these resolution limits, usually require the
+full measurement statistics, which can be challenging to access. In this work,
+we introduce a simple superresolution protocol to estimate the separation
+between two thermal sources which relies only on the average value of a single
+accessible observable. We show how optimal observables for this technique may
+be constructed for arbitrary thermal sources, and we study their sensitivities
+when one has access to spatially resolved intensity measurements (direct
+imaging) and photon counting after spatial mode demultiplexing. For
+demultiplexing, our method is optimal, i.e. it saturates the quantum
+Cram\'er-Rao bound. We also investigate the impact of noise on the optimal
+observables, their measurement sensitivity and on the scaling with the number
+of detected photons of the smallest resolvable separation. For low signals in
+the image plane, we demonstrate that our method saturates the Cram\'er-Rao
+bound even in the presence of noise.",2105.12396v2
+2021-05-25,Improved Constraints for the XUV Luminosity Evolution of Trappist-1,"We re-examine the XUV luminosity evolution of TRAPPIST-1 utilizing new
+observational constraints (XUV and bolometric luminosity) from multi-epoch
+X-ray/UV photometry. Following the formalism presented in Fleming et al.
+(2020), we infer that TRAPPIST-1 maintained a saturated XUV luminosity,
+relative to the bolometric luminosity, of $\log_{10}$(L$_{\rm XUV}$/L$_{\rm
+bol}$) $= -3.03_{-0.23}^{+0.25}$ at early times for a period of $t_{sat} =
+3.14_{-1.46}^{+2.22}$ Gyr. After the saturation phase, we find L$_{\rm XUV}$
+decayed over time by an exponential rate of $\beta_{\rm XUV} =
+-1.17_{-0.28}^{+0.27}$. Compared to our inferred age of the system, ${\rm age}
+= 7.96_{-1.87}^{+1.78}$ Gyr, our result for $t_{sat}$ suggests that there is
+only a $\sim4\%$~chance that TRAPPIST-1 still remains in the saturated phase
+today, which is significantly lower than the previous estimate of 40\%. Despite
+this reduction in $t_{sat}$, our results remain consistent in the conclusion
+that the TRAPPIST-1 planets likely received an extreme amount XUV energy -- an
+estimated integrated XUV energy of $\sim10^{30}-10^{32}$ erg over the star's
+lifetime.",2105.12562v1
+2021-07-02,Nonlinear intensity dependence of terahertz edge photocurrents in graphene,"We report on the observation of terahertz radiation induced edge
+photogalvanic currents in graphene, which are nonlinear in intensity. The
+increase of the radiation intensities up to MW/cm$^2$ results in a complex
+nonlinear intensity dependence of the photocurrent. The nonlinearity is
+controlled by the back gate voltage, temperature and radiation frequency. A
+microscopic theory of the nonlinear edge photocurrent is developed. Comparison
+of the experimental data and theory demonstrates that the nonlinearity of the
+photocurrent is caused by the interplay of two mechanisms, i.e. by direct
+inter-band optical transitions and Drude-like absorption. Both photocurrents
+saturate at high intensities, but have different intensity dependencies and
+saturation intensities. The total photocurrent shows a complex sign-alternating
+intensity dependence. The functional behaviour of the saturation intensities
+and amplitudes of both kinds of photogalvanic currents depending on gate
+voltages, temperature, radiation frequency and polarization is in a good
+agreement with the developed theory.",2107.01016v1
+2021-07-15,Optical solitons in saturable cubic-quintic nonlinear media with nonlinear dispersion,"We study an intense-short pulse propagation in a saturable cubic-quintic
+nonlinear media in the presence of nonlinear dispersion within the framework of
+an extended variational approach. We derive an effective equation for the pulse
+width and demonstrate how the saturation due to nonlinearity is achieved in
+presence of nonlinear dispersion. We find that the nonlinear dispersion can
+change the pulse width and induce motion in the system. The direction of
+induced motion depends on the sign of nonlinear dispersion. The pulse is
+energetically stable at an equilibrium width. A disturbance can, however,
+induce oscillation in pulse width, the frequency of which is always smaller due
+to nonlinear dispersion. We check dynamical stability by a direct numerical
+simulation.",2107.07536v1
+2021-07-19,Saturation of Thermal Complexity of Purification,"We purify the thermal density matrix of a free harmonic oscillator as a
+two-mode squeezed state, characterized by a squeezing parameter and squeezing
+angle. While the squeezing parameter is fixed by the temperature and frequency
+of the oscillator, the squeezing angle is otherwise undetermined, so that the
+complexity of purification is obtained by minimizing the complexity of the
+squeezed state over the squeezing angle. The resulting complexity of the
+thermal state is minimized at non-zero values of the squeezing angle and
+saturates to an order one number at high temperatures, indicating that there is
+no additional operator cost required to build thermal states beyond a certain
+temperature. We also review applications in which thermal density matrices
+arise for quantum fields on curved spacetimes, including Hawking radiation and
+a simple model of decoherence of cosmological density perturbations in the
+early Universe. The complexity of purification for these mixed states also
+saturates as a function of the effective temperature, which may have
+interesting consequences for the quantum information stored in these systems.",2107.08969v1
+2021-07-26,Gluon saturation in proton and its contribution to single inclusive soft gluon production in high energy proton-nucleus collisions,"The leading order single inclusive soft gluon production in high energy
+proton-nucleus (pA) collisions has been studied by various approaches for more
+than two decades. The first correction due to the gluon saturation in proton
+was analytically attempted recently through a diagrammatic approach in which
+only partial results were obtained. An important feature of the first
+saturation correction is that it includes both initial state and final state
+interactions. In this paper, we present the complete result derived from the
+Color Glass Condensate framework. Our approach is to analytically solve the
+classical Yang-Mills equations in the dilute-dense regime and then use the
+Lehmann-Symanzik-Zimmermann (LSZ) reduction formula to obtain gluon production
+from classical gluon fields.",2107.12338v1
+2021-07-28,Widom factors for generalized Jacobi measures,"We study optimal lower and upper bounds for Widom factors $W_{\infty,n}(K,w)$
+associated with Chebyshev polynomials for the weights $w(x)=\sqrt{1+x}$ and
+$w(x)=\sqrt{1-x}$ on compact subsets of $[-1,1]$. We show which sets saturate
+these bounds. We consider Widom factors $W_{2,n}(\mu)$ for $L_2(\mu)$ extremal
+polynomials for measures of the form $d\mu(x)=(1-x)^\alpha (1+x)^\beta
+d\mu_K(x)$ where $\alpha+\beta\geq 1$, $\alpha,\beta\in\mathbb{N}\cup \{0\}$
+and $\mu_K$ is the equilibrium measure of a compact regular set $K$ in $[-1,1]$
+with $\pm 1\in K$. We show that for such measures the improved lower bound
+$[W_{2,n}(\mu)]^2\geq 2S(\mu)$ holds. For the special cases
+$d\mu(x)=(1-x^2)d\mu_K(x)$, $d\mu(x)=(1-x)d\mu_K(x)$, $d\mu(x)=(1+x)d\mu_K(x)$
+we determine which sets saturate this lower bound and discuss how saturated
+lower bounds for $[W_{2,n}(\mu)]^2$ and $W_{\infty,n}(K,w)$ are related.",2107.13245v1
+2021-08-23,Rewrite Rule Inference Using Equality Saturation,"Many compilers, synthesizers, and theorem provers rely on rewrite rules to
+simplify expressions or prove equivalences. Developing rewrite rules can be
+difficult: rules may be subtly incorrect, profitable rules are easy to miss,
+and rulesets must be rechecked or extended whenever semantics are tweaked.
+Large rulesets can also be challenging to apply: redundant rules slow down
+rule-based search and frustrate debugging. This paper explores how equality
+saturation, a promising technique that uses e-graphs to apply rewrite rules,
+can also be used to infer rewrite rules. E-graphs can compactly represent the
+exponentially large sets of enumerated terms and potential rewrite rules. We
+show that equality saturation efficiently shrinks both sets, leading to faster
+synthesis of smaller, more general rulesets.
+  We prototyped these strategies in a tool dubbed ruler. Compared to a similar
+tool built on CVC4, ruler synthesizes 5.8X smaller rulesets 25X faster without
+compromising on proving power. In an end-to-end case study, we show
+ruler-synthesized rules which perform as well as those crafted by domain
+experts, and addressed a longstanding issue in a popular open source tool.",2108.10436v1
+2021-08-24,Approximate Petz recovery from the geometry of density operators,"We derive a new bound on the effectiveness of the Petz map as a universal
+recovery channel in approximate quantum error correction using the second
+sandwiched R\'{e}nyi relative entropy $\tilde{D}_{2}$. For large Hilbert
+spaces, our bound implies that the Petz map performs quantum error correction
+with order-$\epsilon$ accuracy whenever the data processing inequality for
+$\tilde{D}_{2}$ is saturated up to terms of order $\epsilon^2$ times the
+inverse Hilbert space dimension. Conceptually, our result is obtained by
+extending arXiv:2011.03473, in which we studied exact saturation of the data
+processing inequality using differential geometry, to the case of approximate
+saturation. Important roles are played by (i) the fact that the exponential of
+the second sandwiched R\'{e}nyi relative entropy is quadratic in its first
+argument, and (ii) the observation that the second sandwiched R\'{e}nyi
+relative entropy satisfies the data processing inequality even when its first
+argument is a non-positive Hermitian operator.",2108.10893v4
+2021-09-17,Extremal Chaos,"In maximally chaotic quantum systems, a class of out-of-time-order
+correlators (OTOCs) saturate the Maldacena-Shenker-Stanford (MSS) bound on
+chaos. Recently, it has been shown that the same OTOCs must also obey an
+infinite set of (subleading) constraints in any thermal quantum system with a
+large number of degrees of freedom. In this paper, we find a unique analytic
+extension of the maximally chaotic OTOC that saturates all the subleading chaos
+bounds which allow saturation. This extremally chaotic OTOC has the feature
+that information of the initial perturbation is recovered at very late times.
+Furthermore, we argue that the extremally chaotic OTOC provides a
+K\""{a}llen-Lehmann-type representation for all OTOCs. This representation
+enables the identification of all analytic completions of maximal chaos as
+small deformations of extremal chaos in a precise way.",2109.08693v2
+2021-10-04,HDR-cGAN: Single LDR to HDR Image Translation using Conditional GAN,"The prime goal of digital imaging techniques is to reproduce the realistic
+appearance of a scene. Low Dynamic Range (LDR) cameras are incapable of
+representing the wide dynamic range of the real-world scene. The captured
+images turn out to be either too dark (underexposed) or too bright
+(overexposed). Specifically, saturation in overexposed regions makes the task
+of reconstructing a High Dynamic Range (HDR) image from single LDR image
+challenging. In this paper, we propose a deep learning based approach to
+recover details in the saturated areas while reconstructing the HDR image. We
+formulate this problem as an image-to-image (I2I) translation task. To this
+end, we present a novel conditional GAN (cGAN) based framework trained in an
+end-to-end fashion over the HDR-REAL and HDR-SYNTH datasets. Our framework uses
+an overexposed mask obtained from a pre-trained segmentation model to
+facilitate the hallucination task of adding details in the saturated regions.
+We demonstrate the effectiveness of the proposed method by performing an
+extensive quantitative and qualitative comparison with several state-of-the-art
+single-image HDR reconstruction techniques.",2110.01660v2
+2021-10-05,Exploring the Limits of Large Scale Pre-training,"Recent developments in large-scale machine learning suggest that by scaling
+up data, model size and training time properly, one might observe that
+improvements in pre-training would transfer favorably to most downstream tasks.
+In this work, we systematically study this phenomena and establish that, as we
+increase the upstream accuracy, the performance of downstream tasks saturates.
+In particular, we investigate more than 4800 experiments on Vision
+Transformers, MLP-Mixers and ResNets with number of parameters ranging from ten
+million to ten billion, trained on the largest scale of available image data
+(JFT, ImageNet21K) and evaluated on more than 20 downstream image recognition
+tasks. We propose a model for downstream performance that reflects the
+saturation phenomena and captures the nonlinear relationship in performance of
+upstream and downstream tasks. Delving deeper to understand the reasons that
+give rise to these phenomena, we show that the saturation behavior we observe
+is closely related to the way that representations evolve through the layers of
+the models. We showcase an even more extreme scenario where performance on
+upstream and downstream are at odds with each other. That is, to have a better
+downstream performance, we need to hurt upstream accuracy.",2110.02095v1
+2021-10-13,Statistical-mechanical analysis of adaptive filter with clipping saturation-type nonlinearity,"In most practical adaptive signal processing systems, e.g., active noise
+control, active vibration control, and acoustic echo cancellation, substantial
+nonlinearities that cannot be neglected exist. In this paper, we analyze the
+behaviors of an adaptive system in which the output of the adaptive filter has
+the clipping saturation-type nonlinearity by a statistical-mechanical method.
+We discuss the dynamical and steady-state behaviors of the adaptive system by
+asymptotic analysis, steady-state analysis, and numerical calculation. As a
+result, it has become clear that the saturation value has the critical point at
+which the system's mean-square stability and instability switch. The obtained
+theory well explains the strange behaviors around the critical point observed
+in the computer simulation. Finally, the exact value of the critical point is
+also derived.",2110.06517v5
+2021-10-15,Z3RO Precoder Canceling Nonlinear Power Amplifier Distortion in Large Array Systems,"Large array-based transmission uses the combination of a massive number of
+antenna elements and clever precoder designs to achieve array gain and
+spatially multiplex different users. These precoders require linear front-ends,
+and more specifically linear power amplifiers (PAs). However, this reduces
+energy efficiency since PAs are most efficient close to saturation, where they
+generate most nonlinear distortion. Moreover, the use of conventional
+precoders, such as \gls{mrt}, induces a coherent combining of distortion at the
+user location, degrading the signal quality. In this work, a linear precoder is
+proposed that allows working close to saturation while canceling the coherent
+combining of the third order nonlinear \gls{pa} distortion at the user
+location. In contrast to other solutions, the zero third-order distortion
+(Z3RO) precoder does not require prior knowledge of the signal statistics and
+the PA model. The design consists of saturating a single or a few antennas on
+purpose together with an opposite phase shift to compensate for the distortion
+of all other antennas. The resulting array gain penalty becomes negligible as
+the number of base station antennas grows large.",2110.07891v1
+2021-12-08,Accessing subnuclear fluctuations and saturation with multiplicity dependent $J/ψ$ production in p+p and p+Pb collisions,"We study the production of $J/\psi$ vector mesons as a function of charged
+hadron multiplicity in p+p and p+Pb collisions at LHC energies. We employ the
+color glass condensate framework, using running coupling Balitsky-Kovchegov
+evolved dipole amplitudes, to compute gluon and $c\bar{c}$-pair production. We
+use fragmentation functions to obtain charged hadrons, and explore two
+different hadronization schemes for the $J/\psi$: non-relativistic quantum
+chromodynamics and the improved color evaporation model. In our framework,
+event-by-event multiplicity fluctuations of both hadrons and $J/\psi$ are
+driven by geometric and saturation scale normalization fluctuations. Studying
+the correlation between $J/\psi$ and hadron multiplicity, we show that the
+characteristic difference between forward and backward rapidity in p+Pb
+collisions is a result of different degrees of saturation probed at different
+rapidities. We demonstrate that experimental data on heavy-flavor production as
+a function of event activity provide stringent constraints on the fluctuating
+proton structure.",2112.04611v1
+2021-12-17,Binomial expansion for saturated and symbolic powers of sums of ideals,"There are two different notions for symbolic powers of ideals existing in the
+literature, one defined in terms of associated primes, the other in terms of
+minimal primes. Elaborating on an idea known to Eisenbud, Herzog, Hibi, and
+Trung, we interpret both notions of symbolic powers as suitable saturations of
+the ordinary powers. We prove a binomial expansion formula for saturated powers
+of sums of ideals. This gives a uniform treatment to an array of existing and
+new results on both notions of symbolic powers of such sums: binomial expansion
+formulas, computations of depth and regularity, and criteria for the equality
+of ordinary and symbolic powers.",2112.09338v1
+2021-12-27,Mathematics of Parking: Varying Parking Rate,"In the classical parking problem, unit intervals (""car lengths"") are placed
+uniformly at random without overlapping. The process terminates at saturation,
+i.e. until no more unit intervals can be stowed. In this paper, we present a
+generalization of this problem in which the unit intervals are placed with an
+exponential distribution with rate parameter $\lambda$. We show that the
+mathematical expectation of the number of intervals present at saturation
+satisfies a certain integral equation. Using Laplace transforms and Tauberian
+theorems, we investigate the asymptotic behavior of this function and describe
+a way to compute the corresponding limits for large $\lambda$. Then, we derive
+another integral equation for the derivative of this function and use it to
+compute the above limits for small $\lambda$ with the help of some asymptotic
+results for integral equations. We also show that the corresponding limits
+converge to the uniform case as $\lambda$ vanishes, yielding the well-known
+Renyi constant. Finally, we reveal the asymptotic behavior of the variance of
+the intervals at saturation.",2112.13695v1
+2022-01-05,Uncertainty in solar wind forcing explains polar cap potential saturation,"Extreme space weather events occur during intervals of strong solar wind
+electric fields. Curiously during these intervals, their impact on measures of
+the Earth's response, like the polar cap index, is not as high as expected.
+Theorists have put forward a host of explanations for this saturation effect,
+but there is no consensus. Here we show that the saturation is merely a
+perception created by uncertainty in the solar wind measurements, especially in
+the measurement times. Correcting for the uncertainty reveals that extreme
+space weather events elicit a ~300% larger impact than previously thought.
+Furthermore, they point to a surprisingly general result relevant to any
+correlation study: uncertainty in the measurement time can cause a system's
+linear response to be perceived as non-linear.",2201.02137v1
+2022-01-22,The saturation of the VSI in protoplanetary disks via parametric instability,"The vertical shear instability (VSI) is a robust and potentially important
+phenomenon in irradiated protoplanetary disks (PPDs), yet the mechanism by
+which it saturates remains poorly understood. Global simulations suggest that
+the non-linear evolution of the VSI is dominated by radially propagating
+inertial wavetrains (called `body modes'), but these are known to be
+susceptible to a parametric instability. In this paper, we propose that the
+global VSI saturates via this secondary instability, which initiates a
+redistribution of energy from the large scales to smaller-scale inertial waves,
+and finally into a turbulent cascade. We present an analytic theory of the
+instability in a simple idealised model that captures the main physical and
+mathematical details of the problem. In addition, we conduct numerical
+simulations with the SNOOPY code to consolidate the theory. Once the parametric
+instability prevails, the VSI is likely far more disordered and incoherent than
+current global simulations suggest. We also argue that it is challenging to
+capture parametric instability in global simulations unless the radial
+resolution is very fine, possibly $\sim 300$ grid cells per scale height in
+radius.",2201.09038v1
+2022-01-28,Machine learning-based method of calorimeter saturation correction for helium flux analysis with DAMPE experiment,"DAMPE is a space-borne experiment for the measurement of the cosmic-ray
+fluxes at energies up to around 100 TeV per nucleon. At energies above several
+tens of TeV, the electronics of DAMPE calorimeter would saturate, leaving
+certain bars with no energy recorded. In the present work we discuss the
+application of machine learning techniques for the treatment of DAMPE data, to
+compensate the calorimeter energy lost by saturation.",2201.12185v3
+2022-02-23,Unravelling Saturable Absorption of Thulium-doped Fibres for New Level of Integrated Femtosecond Pulse Generation,"The ultrashort pulse laser operation is crucially defined by engaging
+explicit modulators. Conventionally, they are laborious to incorporate into an
+all-fibre design or involve the design of sophisticated cavities. We exploit
+Thulium-doped fibre as the gain and simple, highly integrated saturable
+absorber with a modulation depth of 23% and a high thermal damage threshold.
+Hence, pulses as short as 350fs carrying 1nJ energy at a repetition rate of
+45MHz have been demonstrated. The laser average output power showed long-term
+stability with ~1%. The utilised concept of all-fibre saturable absorber
+provides technological grounds for a down-scaled, highly integrated laser
+architecture.",2202.11370v1
+2022-03-10,Out-of-time-order correlators of nonlocal block-spin and random observables in integrable and nonintegrable spin chains,"Out-of-time-order correlators (OTOC) in the Ising Floquet system, that can be
+both integrable and nonintegrable is studied. Instead of localized spin
+observables, we study contiguous symmetric blocks of spins or random operators
+localized on these blocks as observables. We find only power-law growth of OTOC
+in both integrable and nonintegrable regimes. In the non-integrable regime,
+beyond the scrambling time, there is an exponential saturation of the OTOC to
+values consistent with random matrix theory. This motivates the use of
+""pre-scrambled"" random block operators as observables. A pure exponential
+saturation of OTOC in both integrable and nonintegrable system is observed,
+without a scrambling phase. Averaging over random observables from the Gaussian
+unitary ensemble, the OTOC is found to be exactly same as the operator
+entanglement entropy, whose exponential saturation has been observed in
+previous studies of such spin-chains.",2203.05494v1
+2022-03-19,Soft Pomeron in the Colour Glass Condensate approach,"In this paper we suggest a new approach to the structure of the soft Pomeron:
+based on the $t$-channel unitarity, we expressed the exchange of the soft
+Pomeron through the interaction of the dipole of small size of the order of
+$1/Q_s(Y)$ ($Q_s(Y)$ is the saturation momentum) with the hadrons. Therefore,
+it is shown that the typical distances in soft processes are small $r \sim
+1/Q_s\Lb \h Y \Rb $, where $Y \,=\,ln s$. The saturation momentum, which
+determines the energy dependence of the scattering amplitude is proportional to
+$ Q^2_s\Lb \h Y \Rb \propto\,\exp\Lb\h \lambda\,Y\Rb$, with $\lambda
+\approx\,0.2$, and this behaviour is in perfect agreement with phenomenological
+Donnachie-Landshoff Pomeron. We demonstrate that the saturation models could
+describe the experimental data for $\sigma_{tot},\sigma_{el},\sigma_{diff} $
+and $B_{el}$. Hence our approach is a good first approximation to start
+discussion of the soft processes in CGC approach on the solid theoretical
+basis.",2203.10296v1
+2022-03-25,Quantum thermometry in diffraction-limited systems,"We investigate the ultimate quantum limit of resolving the temperatures of
+two thermal sources affected by the diffraction. More quantum Fisher
+information can be obtained with the priori information than that without the
+priori information. We carefully consider two strategies: the simultaneous
+estimation and the individual estimation. The simultaneous estimation of two
+temperatures is proved to satisfy the saturation condition of quantum
+Cram\'{e}r bound and performs better than the individual estimation in the case
+of small degree of diffraction given the same resources. However, in the case
+of high degree of diffraction, the individual estimation performs better. In
+particular, at the maximum diffraction, the simultaneous estimation can not get
+any information, which is supported by a practical measurement, while the
+individual estimation can still get the information. In addition, we find that
+for the individual estimation, a practical and feasible estimation strategy by
+using the full Hermite-Gauss basis can saturate the quantum Cram\'{e}r bound
+without being affected by the attenuation factor at the maximum diffraction.
+using the full Hermite-Gauss basis can saturate the quantum Cram\'er bound
+without being affected by the attenuation factor at the maximum diffraction.",2203.13466v1
+2022-03-30,Saturated total-population dependent branching process and viral markets,"Interesting posts are continually forwarded by the users of the online social
+network (OSN). Such propagation leads to re-forwarding of the post to some of
+the previous recipients, which increases as the post reaches a large number of
+users. Consequently, the effective forwards (after deleting the re-forwards)
+reduce, eventually leading to the saturation of the total number of copies. We
+model this process as a new variant of the branching process, the `saturated
+total-population-dependent branching process', and analyse it using the
+stochastic approximation technique. Notably, we obtain deterministic
+trajectories which approximate the total and unread copies of the post
+`asymptotically and almost surely' over any finite time window; this trajectory
+depends only on four parameters related to the network characteristics.
+Further, we provide expressions for the peak unread copies, maximum outreach
+and the life span of the post. We observe known exponential growth but with
+time-varying rates. We also validate our theory through detailed simulations on
+the SNAP Twitter dataset.",2203.16239v2
+2022-04-07,The saturation problem for refined Littlewood-Richardson coefficients,"Given partitions $\lambda,\mu,\nu$ with at most $n$ nonzero parts and a
+permutation $w \in S_n$, the refined Littlewood-Richardson coefficient
+$c_{\lambda \mu}^\nu(w)$ is the multiplicity of the irreducible $GL_n
+\mathbb(C)$ module $V(\nu)$ in the so-called Kostant-Kumar submodule
+$K(\lambda, w, \mu)$ of the tensor product $V(\lambda) \otimes V(\mu)$. We
+derive a hive model for these coefficients and prove that the saturation
+property holds if $w$ is $312$-avoiding, $231$-avoiding or a commuting product
+of such elements. This generalizes the classical Knutson-Tao saturation
+theorem.",2204.03399v1
+2022-04-18,Securing Signal-free Intersections against Strategic Jamming Attacks: A Macroscopic Approach,"We consider the security-by-design of a signal-free intersection for
+connected and autonomous vehicles in the face of strategic jamming attacks. We
+use a fluid model to characterize macroscopic traffic flow through the
+intersection, where the saturation rate is derived from a vehicle coordination
+algorithm. We model jamming attacks as sudden increase in communication latency
+induced on vehicle-to-infrastructure connectivity; such latency triggers the
+safety mode for vehicle coordination and thus reduces the intersection
+saturation rate. A strategic attacker selects the attacking rate, while a
+system operator selects key design parameters, either the saturation rate or
+the recovery rate. Both players' actions induce technological costs and jointly
+determine the mean travel delay. By analyzing the equilibrium of the security
+game, we study the preferable level of investment in the intersection's nominal
+discharging capability or recovery capability.",2204.08187v2
+2022-05-10,Machine learning and atomic layer deposition: predicting saturation times from reactor growth profiles using artificial neural networks,"In this work we explore the application of deep neural networks to the
+optimization of atomic layer deposition processes based on thickness values
+obtained at different points of an ALD reactor. We introduce a dataset designed
+to train neural networks to predict saturation times based on the dose time and
+thickness values measured at different points of the reactor for a single
+experimental condition. We then explore different artificial neural network
+configurations, including depth (number of hidden layers) and size (number of
+neurons in each layers) to better understand the size and complexity that
+neural networks should have to achieve high predictive accuracy. The results
+obtained show that trained neural networks can accurately predict saturation
+times without requiring any prior information on the surface kinetics. This
+provides a viable approach to minimize the number of experiments required to
+optimize new ALD processes in a known reactor. However, the datasets and
+training procedure depend on the reactor geometry.",2205.08378v1
+2022-05-27,Rotational level spacings in HD from vibrational saturation spectroscopy,"The R(1), R(3) and P(3) ro-vibrational transitions in the (2-0) overtone band
+of the HD molecule are measured in Doppler-free saturation using the technique
+of NICE-OHMS spectroscopy. For the P(3) line, hitherto not observed in
+saturation, we report a frequency of $203\,821\,936\,805\,(60)$ kHz. The
+dispersive line shapes observed in the three spectra show strong correlations,
+allowing for extraction of accurate information on rotational level spacings.
+This leads to level spacings of $\Delta_{(J=3)-(J=1)}= 13\,283\,245\,098\,(30)$
+kHz in the $v=0$ ground state, and $\Delta_{(J=4)-(J=2)}=
+16\,882\,368\,179\,(20)$ kHz in the $v=2$ excited vibration in HD. These
+results show that experimental values for the rotational spacings are
+consistently larger than those obtained with advanced ab initio theoretical
+calculations at 1.5$\sigma$, where the uncertainty is determined by theory. The
+same holds for the vibrational transitions where systematic deviations of
+1.7-1.9$\sigma$ are consistently found for the five lines accurately measured
+in the (2-0) band.",2205.13877v1
+2022-06-21,New possibilities in identification of binary choice models with fixed effects,"We study the identification of binary choice models with fixed effects. We
+provide a condition called sign saturation and show that this condition is
+sufficient for the identification of the model. In particular, we can guarantee
+identification even with bounded regressors. We also show that without this
+condition, the model is not identified unless the error distribution belongs to
+a small class. The same sign saturation condition is also essential for
+identifying the sign of treatment effects. A test is provided to check the sign
+saturation condition and can be implemented using existing algorithms for the
+maximum score estimator.",2206.10475v4
+2022-07-05,On the two-point function of the Potts model in the saturation regime,"We consider the Random-Cluster model on $\mathbb{Z}^d$ with interactions of
+infinite range of the form $J_x = \psi(x)\mathsf{e}^{-\rho(x)}$ with $\rho$ a
+norm on $\mathbb{Z}^d$ and $\psi$ a subexponential correction. We first provide
+an optimal criterion ensuring the existence of a nontrivial saturation regime
+(that is, the existence of $\beta_{\rm sat}(s)>0$ such that the inverse
+correlation length in the direction $s$ is constant on $[0,\beta_{\rm
+sat}(s))$), thus removing a regularity assumption used in a previous work of
+ours. Then, under suitable assumptions, we derive sharp asymptotics (which are
+not of Ornstein-Zernike form) for the two-point function in the whole
+saturation regime $(0,\beta_{\rm sat}(s))$. We also obtain a number of
+additional results for this class of models, including sharpness of the phase
+transition, mixing above the critical temperature and the strict monotonicity
+of the inverse correlation length in $\beta$ in the regime $(\beta_{\rm
+sat}(s), \beta_{\rm c})$.",2207.02193v2
+2022-07-15,Exact antichain saturation numbers via a generalisation of a result of Lehman-Ron,"For given positive integers $k$ and $n$, a family $\mathcal{F}$ of subsets of
+$\{1,\dots,n\}$ is $k$-antichain saturated if it does not contain an antichain
+of size $k$, but adding any set to $\mathcal{F}$ creates an antichain of size
+$k$. We use sat$^*(n, k)$ to denote the smallest size of such a family. For all
+$k$ and sufficiently large $n$, we determine the exact value of sat$^*(n, k)$.
+Our result implies that sat$^*(n, k)=n(k-1)-\Theta(k\log k)$, which confirms
+several conjectures on antichain saturation. Previously, exact values for
+sat$^*(n,k)$ were only known for $k$ up to $6$.
+  We also prove a generalisation of a result of Lehman-Ron which may be of
+independent interest. We show that given $m$ disjoint chains in the Boolean
+lattice, we can create $m$ disjoint skipless chains that cover the same
+elements (where we call a chain skipless if any two consecutive elements differ
+in size by exactly one).",2207.07391v2
+2022-07-15,Krylov complexity from integrability to chaos,"We apply a notion of quantum complexity, called ""Krylov complexity"", to study
+the evolution of systems from integrability to chaos. For this purpose we
+investigate the integrable XXZ spin chain, enriched with an integrability
+breaking deformation that allows one to interpolate between integrable and
+chaotic behavior. K-complexity can act as a probe of the integrable or chaotic
+nature of the underlying system via its late-time saturation value that is
+suppressed in the integrable phase and increases as the system is driven to the
+chaotic phase. We furthermore ascribe the (under-)saturation of the late-time
+bound to the amount of disorder present in the Lanczos sequence, by mapping the
+complexity evolution to an auxiliary off-diagonal Anderson hopping model. We
+compare the late-time saturation of K-complexity in the chaotic phase with that
+of random matrix ensembles and find that the chaotic system indeed approaches
+the RMT behavior in the appropriate symmetry class. We investigate the
+dependence of the results on the two key ingredients of K-complexity: the
+dynamics of the Hamiltonian and the character of the operator whose time
+dependence is followed.",2207.07701v2
+2022-07-25,Fluctuation of Chern Numbers in a Parametric Random Matrix Model,"Band-touching Weyl points in Weyl semimetals give rise to many novel
+characteristics, one of which the presence of surface Fermi-arc states that is
+topologically protected. The number of such states can be computed by the Chern
+numbers at different momentum slices, which fluctuates with changing momentum
+and depends on the distribution of Weyl points in the Brillouin zone. For
+realistic systems, it may be difficult to locate the momenta at which these
+Weyl points and Fermi-arc states appear. Therefore, we extend the analysis of a
+parametric random matrix model proposed by Walker and Wilkinson to find the
+statistics of their distributions. Our numerical data shows that Weyl points
+with opposite polarities are short range correlated, and the Chern number
+fluctuation only grows linearly for a limited momentum difference before it
+saturates. We also find that the saturation value scales with the total number
+of bands. We then compute the short-range correlation length from perturbation
+theory, and derive the dependence of the Chern number fluctuation on the
+momentum difference, showing that the saturation results from the short-range
+correlation.",2207.12562v1
+2022-07-28,Saturation of Rogue Wave Amplification over Steep Shoals,"The shoaling of surface gravity waves has been acknowledged as a mechanism of
+rogue wave formation. This problem is generally reduced to water waves passing
+over a step, but non-equilibrium physics allows finite slopes to be considered.
+Using non-homogeneous spectral analysis of a spatially varying energy density
+ratio we describe the dependence of the amplification as a function of the
+slope steepness. Increasing the slope increases the amplification of rogue wave
+probability, until this amplification saturates at steep slopes. In contrast,
+the increase of the down slope of a subsequent de-shoal zone leads to a
+monotonic decrease in the rogue wave probability, thus featuring a strong
+asymmetry between shoaling and de-shoaling zones. Due to the saturation of the
+rogue wave amplification at steep slopes, our model is applicable beyond its
+range of validity up to a step, thus elucidating why previous models based on a
+step could describe the physics of steep finite slopes. We also explain why the
+rogue wave probability increases over a shoal while it is lower in shallower
+water.",2207.13869v3
+2022-08-26,Saturation of multidimensional 0-1 matrices,"A 0-1 matrix $M$ is saturating for a 0-1 matrix $P$ if $M$ does not contain a
+submatrix that can be turned into $P$ by flipping any number of its $1$-entries
+to $0$-entries, and changing any $0$-entry to $1$-entry of $M$ introduces a
+copy of $P$. Matrix $M$ is semisaturating for $P$ if changing any $0$-entry to
+$1$-entry of $M$ introduces a new copy of $P$, regardless of whether $M$
+originally contains $P$ or not. The functions $ex(n;P)$ and $sat(n;P)$ are the
+maximum and minimum possible number of $1$-entries a $n\times n$ 0-1 matrix
+saturating for $P$ can have, respectively. Function $ssat(n;P)$ is the minimum
+possible number of $1$-entries a $n\times n$ 0-1 matrix semisaturating for $P$
+can have.
+  Function $ex(n;P)$ has been studied for decades, while investigation on
+$sat(n;P)$ and $ssat(n;P)$ was initiated recently. In this paper, we make
+nontrivial generalization of results regarding these functions to
+multidimensional 0-1 matrices. In particular, we find the exact values of
+$ex(n;P,d)$ and $sat(n;P,d)$ when $P$ is a $d$-dimensional identity matrix.
+Then we give the necessary and sufficient condition for a multidimensional 0-1
+matrix to have bounded semisaturation function.",2208.12682v1
+2022-08-28,Classical information entropy of parton distribution functions and an application in finding gluon saturation,"Entropy or information is a fundamental quantity contained in a system in
+statistical mechanics and information theory. In this paper, a definition of
+classical information entropy of parton distribution functions is suggested.
+The extensive and supper-additive properties of the defined entropy are
+discussed. The concavity is also deduced for the defined entropy. As an
+example, the classical information entropy of the gluon distribution of the
+proton is presented. There are some particular features of the evolution of the
+information entropy in the saturating domain, which can be used in finding the
+signals of gluon saturation.",2208.13151v4
+2022-09-05,Competition between phonon mediated superconductivity and carriers localization in field-effect doped molybdenum dichalcogenides,"Superconductivity occurs in electrochemically doped molybdenum
+dichalcogenides samples thicker than four layers. While the critical
+temperature (Tc) strongly depends on the field effect geometry (single or
+double gate) and on the sample (MoS2 or MoSe2), Tc always saturates at high
+doping. The pairing mechanism and the complicate dependence of Tc on doping,
+samples and field-effect geometry are currently not understood. Previous
+theoretical works assumed homogeneous doping of a single layer and attributed
+the Tc saturation to a charge density wave instability, however the calculated
+values of the electron-phonon coupling in the harmonic approximation were one
+order of magnitude larger than the experimental estimates based on transport
+data. Here, by performing fully relativistic first principles calculations
+accounting for the sample thickness, the field-effect geometry and
+anharmonicity, we rule out the occurrence of charge density waves in the
+experimental doping range and demonstrate a suppression of one order of
+magnitude in the electron-phonon coupling, now in excellent agreement with
+transport data. By solving the anisotropic Migdal-Eliashberg equations, we
+explain the behaviour of Tc in different systems and geometries. From an
+analysis of mobility data, we propose that the Tc saturation is due to carriers
+localization and disorder.",2209.01973v1
+2022-09-06,On the saturation of late-time growth of complexity in supersymmetric JT gravity,"In this work we use the modified replica trick, proposed in arXiv:2205.01150,
+to compute the late time behaviour of complexity for JT gravity with ${\cal N}
+= 1$ and ${\cal N} = 2$ supersymmetries. For the ${\cal N} = 1$ theory, we
+compute the late time behaviour of complexity defined by the ``quenched
+geodesic length"" and obtain the expected saturation of complexity at time $t
+\sim e^{S_0}$, to a constant value with time-independent variance. For the
+${\cal N} = 2$ theory, we explicitly compute complexity at the disk level which
+yields the late-time linear growth of complexity. However, we comment on the
+expectation of the late-time saturation by speculating the trumpet partition
+function and the non-perturbative corrections to the spectral correlation,
+relevant for the late-time behaviour of complexity. Furthermore, we compute the
+matter correlation functions for both the theories.",2209.02441v2
+2022-09-07,Small Proofs from Congruence Closure,"Satisfiability Modulo Theory (SMT) solvers and equality saturation engines
+must generate proof certificates from e-graph-based congruence closure
+procedures to enable verification and conflict clause generation. Smaller proof
+certificates speed up these activities. Though the problem of generating proofs
+of minimal size is known to be NP-complete, existing proof minimization
+algorithms for congruence closure generate unnecessarily large proofs and
+introduce asymptotic overhead over the core congruence closure procedure. In
+this paper, we introduce an O(n^5) time algorithm which generates optimal
+proofs under a new relaxed ""proof tree size"" metric that directly bounds proof
+size. We then relax this approach further to a practical O(n \log(n)) greedy
+algorithm which generates small proofs with no asymptotic overhead. We
+implemented our techniques in the egg equality saturation toolkit, yielding the
+first certifying equality saturation engine. We show that our greedy approach
+in egg quickly generates substantially smaller proofs than the state-of-the-art
+Z3 SMT solver on a corpus of 3760 benchmarks.",2209.03398v1
+2022-09-09,The fractional saturable impurity,"We examine analytically and numerically the effect of fractionality on a
+saturable bulk and surface impurity embedded in a 1D lattice. We use a
+fractional Laplacian introduced previously by us, and by the use of lattice
+Green functions we are able to obtain the bound state energies and amplitude
+profiles, as a function of the fractional exponent $s$ and saturable impurity
+strength $\chi$ for both, surface and bulk impurity. The transmission is
+obtained in closed form as a function of $s$ and $\chi$, showing strong
+deviations from the standard case, at small fractional exponent values. The
+selftrapping of an initially-localized excitation is qualitatively similar for
+the bulk and surface mode, but in all cases complete confinement is obtained at
+$s\rightarrow 0$, as shown theoretically and observed numerically.",2209.04074v1
+2022-10-04,A Fuzzy Logic-based Cascade Control without Actuator Saturation for the Unmanned Underwater Vehicle Trajectory Tracking,"An intelligent control strategy is proposed to eliminate the actuator
+saturation problem that exists in the trajectory tracking process of unmanned
+underwater vehicles (UUV). The control strategy consists of two parts: for the
+kinematic modeling part, a fuzzy logic-refined backstepping control is
+developed to achieve control velocities within acceptable ranges and errors of
+small fluctuations; on the basis of the velocities deducted by the improved
+kinematic control, the sliding mode control (SMC) is introduced in the dynamic
+modeling to obtain corresponding torques and forces that should be applied to
+the vehicle body. With the control velocities computed by the kinematic model
+and applied forces derived by the dynamic model, the robustness and accuracy of
+the UUV trajectory without actuator saturation can be achieved.",2210.01706v1
+2022-10-10,Decreasing ultrafast X-ray pulse durations with saturable absorption and resonant transitions,"Saturable absorption is a nonlinear effect where a material's ability to
+absorb light is frustrated due to a high influx of photons and the creation of
+electron vacancies. Experimentally induced saturable absorption in copper
+revealed a reduction in the temporal duration of transmitted X-ray laser
+pulses, but a complete understanding of this process is still missing. In this
+computational work, we employ non-local thermodynamic equilibrium plasma
+simulations to study the interaction of femtosecond X-rays and copper.
+Following the onset of frustrated absorption, we find that a $K\text{--}M$
+resonant transition occurring at highly charged states turns copper opaque
+again. The changes in absorption generate a transient transparent window
+responsible for the shortened transmission signal. We also propose using
+fluorescence induced by the incident beam as an alternative source to achieve
+shorter X-ray pulses. Intense femtosecond X-ray pulses are valuable to probe
+the structure and dynamics of biological samples or to reach extreme states of
+matter. Shortened pulses could be relevant for emerging imaging techniques.",2210.04938v1
+2022-10-11,Components of $V(ρ) \otimes V(ρ)$ and dominant weight polyhedra for affine Kac-Moody Lie algebras,"Kostant asked the following question: Let $\mathfrak{g}$ be a simple Lie
+algebra over the complex numbers. Let $\lambda$ be a dominant integral weight.
+Then, $V(\lambda)$ is a component of $V(\rho)\otimes V(\rho)$ if and only if
+$\lambda \leq 2 \rho$ under the usual Bruhat-Chevalley order on the set of
+weights. In an earlier work with R. Chirivi and A. Maffei the second author
+gave an affirmative answer to this question up to a saturation factor. The aim
+of the current work is to extend this result to untwisted affine Kac-Moody Lie
+algebra $\mathfrak{g}$ associated to any simple Lie algebra
+$\mathring{\mathfrak{g}}$ (up to a saturation factor). In fact, we prove the
+result for affine $sl_n$ without any saturation factor. Our proof requires some
+additional techniques including the Goddard-Kent-Olive construction and study
+of the characteristic cone of non-compact polyhedra.",2210.05473v2
+2022-10-19,Saturation level of turbulence in collapsing gas clouds,"We investigate the physical mechanism that decides the saturation level of
+turbulence in collapsing gas clouds. We perform a suite of high-resolution
+numerical simulations following the collapse of turbulent gas clouds with
+various effective polytropic exponents $\gamma_{\rm eff}$, initial Mach numbers
+$\mathcal{M}_0$, and initial turbulent seeds. Equating the energy injection
+rate by gravitational contraction and the dissipation rate of turbulence, we
+obtain an analytic expression of the saturation level of turbulence, and
+compare it with the numerical results. Consequently, the numerical results are
+well described by the analytic model, given that the turbulent driving scale in
+collapsing gas clouds is one-third of Jeans length of collapsing core. These
+results indicate that the strength of turbulence at the first core formation in
+the early universe/present-day star-formation process can be estimated solely
+by $\gamma_{\rm eff}$.",2210.10299v1
+2022-10-20,Spectral analysis of multidimensional current-driven plasma instabilities and turbulence in hollow cathode plumes,"Large-amplitude current-driven instabilities in hollow cathode plumes can
+generate energetic ions responsible for cathode sputtering and spacecraft
+degradation. A 2D2V (two dimensions each in configuration [D] and velocity [V]
+spaces) grid-based Vlasov--Poisson (direct kinetic) solver is used to study
+their growth and saturation, which comprises four stages: linear growth,
+quasilinear resonance, nonlinear fill-in, and saturated turbulence. The linear
+modal growth rate, nonlinear saturation process, and ion velocity and energy
+distribution features in the turbulent regime are analyzed. Backstreaming ions
+are generated for large electron drifts, several ion acoustic periods after the
+potential field becomes turbulent. Interscale phase-space transfer and locality
+are analyzed for the Vlasov equation. The multidimensional study sheds light on
+the interactions between longitudinal and transverse plasma instabilities, as
+well as the inception of plasma turbulence.",2210.11056v2
+2022-10-28,Freedom near Lightcone and ANEC Saturation,"Averaged Null Energy Conditions (ANECs) hold in unitary quantum field
+theories. In conformal field theories, ANECs in states created by the
+application of the stress tensor to the vacuum lead to three constraints on the
+stress-tensor three-point couplings, depending on the choice of polarization.
+The same constraints follow from considering two-point functions of the stress
+tensor in a thermal state and focusing on the contribution of the stress tensor
+in the operator product expansion (OPE). One can observe this in holographic
+Gauss-Bonnet gravity, where ANEC saturation coincides with the appearance of
+superluminal signal propagation in thermal states. We show that, when this
+happens, the corresponding generalizations of ANECs for higher-spin
+multi-stress tensor operators with minimal twist are saturated as well and all
+contributions from such operators to the thermal two-point functions vanish in
+the lightcone limit. This leads to a special near-lightcone behavior of the
+thermal stress-tensor correlators -- they take the vacuum form, independent of
+temperature.",2210.16274v3
+2022-11-15,Molecular $P_ψ$ pentaquarks from light-meson exchange saturation,"Theoretical predictions for the spectrum of heavy meson-baryon bound states
+are a fundamental tool for disentangling the nature of the different pentaquark
+states that have been observed in experimental facilities. Here we explore this
+spectrum in a phenomenological model that describes the heavy meson-baryon
+interaction in terms of a contact-range interaction, where the coupling
+strength is saturated by the exchange of light scalar and vector mesons, i.e.
+$\sigma$, $\rho$ and $\omega$ exchanges. Saturation determines the couplings
+modulo an unknown proportionality constant that can be calibrated from a
+molecular candidate. If we use the $P_{\psi}^N(4312)$ as input, we predict a
+series of molecular pentaquarks including the $P_{\psi}^N(4440)$ and
+$P_{\psi}^N(4457)$, the recent $P_{\psi s}^{\Lambda}(4338)$ and the $P_{\psi
+s}^{\Lambda}(4459)$.",2211.08211v1
+2022-11-20,Safe Control Under Input Limits with Neural Control Barrier Functions,"We propose new methods to synthesize control barrier function (CBF)-based
+safe controllers that avoid input saturation, which can cause safety
+violations. In particular, our method is created for high-dimensional, general
+nonlinear systems, for which such tools are scarce. We leverage techniques from
+machine learning, like neural networks and deep learning, to simplify this
+challenging problem in nonlinear control design. The method consists of a
+learner-critic architecture, in which the critic gives counterexamples of input
+saturation and the learner optimizes a neural CBF to eliminate those
+counterexamples. We provide empirical results on a 10D state, 4D input
+quadcopter-pendulum system. Our learned CBF avoids input saturation and
+maintains safety over nearly 100% of trials.",2211.11056v1
+2022-11-28,Inverse saturable absorption mechanism and design optimization of mode-locked fiber lasers with a nonlinear amplifying loop mirror,"From the point of view of the differential phase delay experienced by the two
+counterpropagating optical fields, the self-starting of the mode-locked fiber
+laser with a nonlinear amplifying loop mirror (NALM) is theoretically studied.
+Although it is generally believed that NALM shows a saturable absorption effect
+on both continuous wave (CW) light and pulses, we find a counter-intuitive fact
+that cross-phase modulation (XPM) leads to opposite signs of differential
+nonlinear phase shifts (NPSs) in these two cases, resulting in inverse
+saturable absorption (ISA) during pulse formation process. The ISA is not
+helpful for the self-starting of laser mode-locking and can be alleviated by
+introducing a non-reciprocal phase shifter into the fiber loop. In addition, we
+analyze the influences of gain-fiber position, splitting ratio, and optical
+attenuator in the fiber loop, on the differential NPS and self-starting
+process. These results are helpful for optimizing the design of NALM and
+lowering the self-starting threshold of the high-repetition-rate mode-locked
+fiber laser.",2211.15150v1
+2022-12-04,Enhanced intrinsic voltage gain in artificially stacked bilayer CVD graphene field effect transistors,"We report on electronic transport in dual-gate, artificially stacked bilayer
+graphene field effect transistors (BiGFETs) fabricated from large-area chemical
+vapor deposited (CVD) graphene. The devices show enhanced tendency to current
+saturation, which leads to reduced minimum output conductance values. This
+results in improved intrinsic voltage gain of the devices when compared to
+monolayer graphene FETs. We employ a physics based compact model originally
+developed for Bernal stacked bilayer graphene FETs (BSBGFETs) to explore the
+observed phenomenon. The improvement in current saturation may be attributed to
+increased charge carrier density in the channel and thus reduced saturation
+velocity due to carrier-carrier scattering.",2212.01877v1
+2022-12-12,Physics-preserving IMPES based multiscale methods for immiscible two-phase flow in highly heterogeneous porous media,"In this paper, we propose a physics-preserving multiscale method to solve an
+immiscible two-phase flow problem, which is modeled as a coupling system
+consisting of Darcy's law and mass conservation equations. We use a new
+Physics-preserving IMplicit Pressure Explicit Saturation (P-IMPES) scheme in
+order to maintain the local conservation of mass for both phases. Besides, this
+scheme is unbiased and if the time step is smaller than a certain value, the
+saturation of both phases are bounds-preserving. When updating velocity,
+MGMsFEM serves as an efficient solver by computing the unknowns on a coarse
+grid. We follow the operation splitting techinque to deal with the two-phase
+flow. In particular, we use an upwind strategy to iterate the saturation
+explicitly and the MGMsFEM is utilized to compute velocity with a decoupled
+system on a coarse mesh. To show the efficiency and robustness of the proposed
+method, we design a set of interesting experiments. A rigorous analysis is also
+included to serve as a theoretical base of the method, which is well verified
+by the numerical results. Both simulations and analysis indicate that the
+method attains a good balance between accuracy and computation cost.",2212.05942v1
+2022-12-17,A Thermodynamic Treatment\\ of Partially Saturated Soils \\ Revealing the Structure of Effective Stress,"A rigorous thermodynamic treatment of partially saturated soils is developed
+using a minimal number of assumptions. The derivation is carried out in a way
+that does not require to explicitly track the complex shapes of interfaces
+between the solid, fluid and gas domains. Instead, suction is the property
+being recovered explicitly through the minimisation of energy around an ideal
+`suctionless limit', while considering the different compressibilities of the
+three domains. In interpreting experimental data the derivation ensures the
+thermodynamic equilibrium between the chemical potentials of the soil and
+measurement cells, while carefully distinguishing intrinsic from measured
+pressures and suctions. A most general expression for the effective stress of
+partially saturated soils is then derived that is strictly linked to the
+soil-water retention curve (SWRC). The structure of the effective stress
+broadly depends on the three thermodynamic densities characterising the solid,
+fluid and gas domains. Special cases of SWRC are explored, which reveals
+conditions for which the structure of the effective stress may agree with
+previously proposed empirical relationships.",2212.08868v1
+2022-12-22,"Scaling, saturation, and upper bounds in the failure of topologically interlocked structures","Topological Interlocking Structures (TIS) have been increasingly studied in
+the past two decades. However, some fundamental questions concerning the
+effects of Young's modulus and the friction coefficient on the structural
+mechanics of the most common type of TIS application - centrally loaded slabs -
+are not yet clear. Here, we present a first-of-its-kind parametric study based
+on the Level-Set-Discrete-element-Method that aims to clarify how these two
+parameters affect multiple aspects of the behavior and failure of
+centrally-loaded TIS slabs. This includes the evolution of the structural
+response up to and including failure, the foremost structural response
+parameters, and the residual carrying capacity. We find that the structural
+response parameters in TIS slabs scale linearly with Young's modulus, that they
+saturate with the friction coefficient, and that the saturated response
+provides an upper-bound on the capacity of centrally loaded TIS slabs reported
+in the literature. This, together with additional findings, insights, and
+observations, comprise a novel contribution to our understanding of the
+interlocked structural form.",2212.11554v1
+2022-12-28,Examination of saturation coverage of polygons using random sequential adsorption algorithm,"The goal of random sequential adsorption (RSA), a time-dependent packing
+method, is to create a regular or asymmetric covering of an empty space that
+can fit in the allocated space without overlapping. The density of coverage
+tends to reach a limit in the infinite-time limit. We attempt to estimate
+saturated packing of oriented 2-D polygons, including squares(4-sides), regular
+pentagons (5-sides), regular hexagons (6-sides), regular heptagons (7-sides),
+regular octagons (8-sides), regular nonagons (9-sides), regular decagons
+(10-sides), and regular dodecagons (12-sides), in this study. We obtained
+results that are consistent with previous, extrapolation-based studies1. We
+utilised the ""separating axis theorem"" to determine if there is overlap between
+arriving polygons and those that have previously been placed. Saturation as a
+lower limit is considered to have been reached when RSA addition becomes
+excessively slow, according to us.",2212.13849v2
+2023-01-04,Saturation of fishbone instability by self-generated zonal flows in tokamak plasmas,"Gyrokinetic simulations of the fishbone instability in DIII-D tokamak plasmas
+find that self-generated zonal flows can dominate the nonlinear saturation by
+preventing coherent structures from persisting or drifting in the energetic
+particle phase space when the mode frequency down-chirps. Results from the
+simulation with zonal flows agree quantitatively, for the first time, with
+experimental measurements of the fishbone saturation amplitude and energetic
+particle transport. Moreover, the fishbone-induced zonal flows are likely
+responsible for the formation of an internal transport barrier that was
+observed after fishbone bursts in this DIII-D experiment. Finally, gyrokinetic
+simulations of a related ITER baseline scenario show that the fishbone induces
+insignificant energetic particle redistribution and may enable high performance
+scenarios in ITER burning plasma experiments.",2301.01792v4
+2023-01-30,High-Density behavior of symmetry energy and speed of sound in the dense matter within an effective chiral model,"With an effective chiral model, we investigate how the mesonic cross
+couplings $\sigma-\rho$ and $\omega-\rho$ affect the density content of the
+symmetry energy and its higher-order slope parameters. Earlier mentioned
+cross-couplings are crucial to controlling the density content of symmetry
+energy. For this purpose, we did a case study for different values of the
+symmetry energy $J_1$, defined at density 0.1 fm$^{-3}$ in the range (23.4 -
+25.2) for a fixed value of the slope of the symmetry energy $L_0 = 60$ MeV at
+saturation density and investigate its effect on the higher-order coefficients
+and their influence on the underlying equation of state. We found that the
+model with $J_1= 24.6$ MeV is more favorable with the pure neutron matter (PNM)
+constraints obtained from $\chi$EFT calculations. In addition, we show that all
+of our models predict a monotonically increasing speed of sound up to four
+times the saturation density. The speed of sound decreases/saturates above that
+point and approaches the conformal limit approximately $\sqrt{1/3}~c$ at the
+center of the maximum mass star.",2301.12690v1
+2023-02-13,Complexity growth for one-dimensional free-fermionic lattice models,"Complexity plays a very important part in quantum computing and simulation
+where it acts as a measure of the minimal number of gates that are required to
+implement a unitary circuit. We study the lower bound of the complexity
+[Eisert, Phys. Rev. Lett. 127, 020501 (2021)] for the unitary dynamics of the
+one-dimensional lattice models of non-interacting fermions. We find
+analytically using quasiparticle formalism, the bound grows linearly in time
+and followed by a saturation for short-ranged tight-binding Hamiltonians. We
+show numerical evidence that for an initial Neel state the bound is maximum for
+tight-binding Hamiltonians as well as for the long-range hopping models.
+However, the increase of the bound is sub-linear in time for the later, in
+contrast to the linear growth observed for short-range models. The upper bound
+of the complexity in non-interacting fermionic lattice models is calculated,
+which grows linearly in time even beyond the saturation time of the lower
+bound, and finally, it also saturates.",2302.06305v3
+2023-03-10,Indirect Adaptive Optimal Control in the Presence of Input Saturation,"In this paper, we propose a combined Magnitude Saturated Adaptive Control
+(MSAC)-Model Predictive Control (MPC) approach to linear quadratic tracking
+optimal control problems with parametric uncertainties and input saturation.
+The proposed MSAC-MPC approach first focuses on a stable solution and parameter
+estimation, and switches to MPC when parameter learning is accomplished. We
+show that the MSAC, based on a high-order tuner, leads to parameter convergence
+to true values while providing stability guarantees. We also show that after
+switching to MPC, the optimality gap is well-defined and proportional to the
+parameter estimation error. We demonstrate the effectiveness of the proposed
+MSAC-MPC algorithm through a numerical example based on a linear second-order,
+two input, unstable system.",2303.06221v1
+2023-03-12,Scale-aware Two-stage High Dynamic Range Imaging,"Deep high dynamic range (HDR) imaging as an image translation issue has
+achieved great performance without explicit optical flow alignment. However,
+challenges remain over content association ambiguities especially caused by
+saturation and large-scale movements. To address the ghosting issue and enhance
+the details in saturated regions, we propose a scale-aware two-stage high
+dynamic range imaging framework (STHDR) to generate high-quality ghost-free HDR
+image. The scale-aware technique and two-stage fusion strategy can
+progressively and effectively improve the HDR composition performance.
+Specifically, our framework consists of feature alignment and two-stage fusion.
+In feature alignment, we propose a spatial correct module (SCM) to better
+exploit useful information among non-aligned features to avoid ghosting and
+saturation. In the first stage of feature fusion, we obtain a preliminary
+fusion result with little ghosting. In the second stage, we conflate the
+results of the first stage with aligned features to further reduce residual
+artifacts and thus improve the overall quality. Extensive experimental results
+on the typical test dataset validate the effectiveness of the proposed STHDR in
+terms of speed and quality.",2303.06575v1
+2023-03-17,Comment on arXiv:2210.01114: Optical Saturation Produces Spurious Evidence for Photoinduced Superconductivity in K$_3$C$_{60}$,"In the manuscript arXiv:2210.01114, Dodge and co-authors discuss the
+influence of pump-probe profile deformations on the reconstructed
+non-equilibrium optical conductivity of K$_3$C$_{60}$. They state that when
+pump-induced saturation of the probe response is taken into account, the
+reconstructed optical properties are not superconducting-like, as was claimed
+in a number of experimental reports by our group. We show here that the
+conclusion reached by Dodge et al. is unjustified. In fact, independent of the
+specific model, including the problematic saturation profile proposed by the
+authors, the reconstructed optical properties are those of a finite temperature
+superconductor. The true fingerprint of superconductivity, which is the
+$1/\omega$ divergence of the imaginary conductivity, $\sigma_{2}(\omega)$, is
+retained and is virtually independent of the chosen model. The only
+model-dependent feature is the degree of gapping in $\sigma_{1}(\omega)$. In
+all cases the extracted optical properties reflect the presence of residual
+quasiparticles, which at finite temperatures are inevitably present alongside
+the superfluid.",2303.10169v1
+2023-03-25,Inverted loss engineering in functional material covered waveguides,"Optical waveguides, covered with thin films, which transmittance can be
+controlled by external action, are widely used in various applications from
+optical modulators to saturable absorbers. It is natural to suggest that the
+waveguide losses will be proportional to the covering material absorption. We
+demonstrate that under certain conditions this simple assumption fails.
+Instead, we observe the reduction of the film material absorption can lead to
+an increase in the waveguide propagation losses. For this, we use a side
+polished fiber covered with a single-walled carbon nanotube thin film whose
+absorption is attenuated either due to saturable absorption or electrochemical
+gating. For the films thicker than 50 nm, we observe saturable absorption to
+turn into light induced absorption with nonmonotonic dependence on the incident
+power. With a numerical simulation and analytical approach, we identify that
+this nontrivial behavior comes from mode reshaping and predict required
+parameters for its observation.",2303.14512v1
+2023-03-30,Stability analysis of an SIR model with saturated infection rate and saturated treatment rate,"Treatment rate has always been one of the most important factors affecting
+the spread of infectious diseases. In this paper, we study a treatment function
+SIR model with treatment rate related to the maximum treatment capacity, whose
+infection rate is also saturated nonlinear. By calculating and analyzing based
+on planar dynamic system, the existence and stability of disease-free
+equilibrium point of the model are found. And it is also found that the
+situation is more complex for the endemic equilibrium point of the model. Under
+the conditions of meeting different parameters, the number of endemic
+equilibrium points may be zero, one or two, and the behavior of the endemic
+equilibrium point may be a saddle point, a stable or unstable anti-saddle point
+or center, or even a degenerate case.",2303.17298v1
+2023-03-31,A flatness-based saturated controller design for a quadcopter with experimental validation,"Using the properties of differential flatness, a controllable system, such as
+a quadcoper model, may be transformed into a linear equivalent system via a
+coordinate change and an input mapping. This is a straightforward advantage for
+the quadcopter's controller design and its real-time implementation. However,
+one significant hindrance is that, while the dynamics become linear in the new
+coordinates (the flat output space), the input constraints become convoluted.
+This paper addresses an explicit pre-stabilization based control scheme which
+handles the input constraints for the quadcopter in the flat output space with
+a saturation component. The system's stability is shown to hold by
+Lyapunov-stability arguments. Moreover, the practical viability of the proposed
+method is validated both in simulation and experiments over a nano-drone
+platform. Hence, the flatness-based saturated controller not only ensures
+stability and constraints satisfaction, but also requires very low
+computational effort, allowing for embedded implementations.",2303.18021v1
+2023-03-31,Pathologies in satisfaction classes,"We study subsets of countable recursively saturated models of $\mathsf{PA}$
+which can be defined using pathologies in satisfaction classes. More precisely,
+we characterize those subsets $X$ such that there is a satisfaction class $S$
+where $S$ behaves correctly on an idempotent disjunction of length $c$ if and
+only if $c \in X$. We generalize this result to characterize several types of
+pathologies including double negations, blocks of extraneous quantifiers, and
+binary disjunctions and conjunctions. We find a surprising relationship between
+the cuts which can be defined in this way and arithmetic saturation: namely, a
+countable nonstandard model is arithmetically saturated if and only if every
+cut can be the ""idempotent disjunctively correct cut"" in some satisfaction
+class. We describe the relationship between types of pathologies and the
+closure properties of the cuts defined by these pathologies.",2303.18069v1
+2023-05-28,Josephson parametric amplifier with Chebyshev gain profile and high saturation,"We demonstrate a Josephson parametric amplifier design with a band-pass
+impedance matching network based on a third-order Chebyshev prototype. We
+measured eight amplifiers operating at 4.6 GHz that exhibit gains of 20 dB with
+less than 1 dB gain ripple and up to 500 MHz bandwidth. The amplifiers further
+achieve high output saturation powers around -73 dBm based on the use of
+rf-SQUID arrays as their nonlinear element. We characterize the system readout
+efficiency and its signal-to-noise ratio near saturation using a Sycamore
+processor, finding the data consistent with near quantum limited noise
+performance of the amplifiers. In addition, we measure the amplifiers'
+intermodulation distortion in two-tone experiments as a function of input power
+and inter-tone detuning, and observe excess distortion at small detuning with a
+pronounced dip as a function of signal power, which we interpret in terms of
+power-dependent dielectric losses.",2305.17816v1
+2023-06-21,Analysis of a Crank-Nicolson finite difference scheme for (2+1)D perturbed nonlinear Schrödinger equations with saturable nonlinearity,"We analyze a Crank-Nicolson finite difference discretization for the
+perturbed (2+1)D nonlinear Schr\""odinger equation with saturable nonlinearity
+and a perturbation of cubic loss. We show the boundedness, the existence and
+uniqueness of a numerical solution. We establish the error bound to prove the
+convergence of the numerical solution. Moreover, we find that the convergence
+rate is at the second order in both time step and spatial mesh size under a
+mild assumption. The numerical scheme is validated by the extensive simulations
+of the (2+1)D saturable nonlinear Schr\""odinger model with cubic loss. The
+simulations for travelling solitons are implemented by using an accelerated
+imaginary-time evolution scheme and the Crank-Nicolson finite difference
+method.",2306.12287v1
+2023-06-22,ACC Saturator: Automatic Kernel Optimization for Directive-Based GPU Code,"Automatic code optimization is a complex process that typically involves the
+application of multiple discrete algorithms that modify the program structure
+irreversibly. However, the design of these algorithms is often monolithic, and
+they require repetitive implementation to perform similar analyses due to the
+lack of cooperation. To address this issue, modern optimization techniques,
+such as equality saturation, allow for exhaustive term rewriting at various
+levels of inputs, thereby simplifying compiler design.
+  In this paper, we propose equality saturation to optimize sequential codes
+utilized in directive-based programming for GPUs. Our approach simultaneously
+realizes less computation, less memory access, and high memory throughput. Our
+fully-automated framework constructs single-assignment forms from inputs to be
+entirely rewritten while keeping dependencies and extracts optimal cases.
+Through practical benchmarks, we demonstrate a significant performance
+improvement on several compilers. Furthermore, we highlight the advantages of
+computational reordering and emphasize the significance of memory-access order
+for modern GPUs.",2306.13002v2
+2023-06-30,Upscaling and Effective Behavior for Two-Phase Porous-Medium Flow using a Diffuse Interface Model,"We investigate two-phase flow in porous media and derive a two-scale model,
+which incorporates pore-scale phase distribution and surface tension into the
+effective behavior at the larger Darcy scale. The free-boundary problem at the
+pore scale is modeled using a diffuse interface approach in the form of a
+coupled Allen-Cahn Navier-Stokes system with an additional momentum flux due to
+surface tension forces. Using periodic homogenization and formal asymptotic
+expansions, a two-scale model with cell problems for phase evolution and
+velocity contributions is derived. We investigate the computed effective
+parameters and their relation to the saturation for different fluid
+distributions, in comparison to commonly used relative permeability saturation
+curves. The two-scale model yields non-monotone relations for relative
+permeability and saturation. The strong dependence on local fluid distribution
+and effects captured by the cell problems highlights the importance of
+incorporating pore-scale information into the macro-scale equations.",2306.17644v1
+2023-07-18,Partially Saturated Granular Flow in a Rotating Drum: The Role of Cohesion,"Partially saturated granular flows are common in various natural and
+industrial processes, such as landslides, mineral handling, and food
+processing. We conduct experiments and apply the Discrete Element Method (DEM)
+to study granular flows in rotating drums under partially saturated conditions.
+We focus on varying the strength of cohesion (surface tension) and rotation
+rate within the modes of rolling flow and cascading flow. With an increase in
+surface tension, a rolling mode can possess a steeper slope and correspondingly
+needs a higher rotation rate to transition to a cascading. The depth of the
+flowing region increases with increasing cohesion, while the sensitivity is
+reduced for cases of high cohesion. We propose a dimensionless number CE that
+captures the combined effects of rotation, gravity and cohesion on the dynamic
+angle of repose and flow depth. In addition, we extract statistical information
+on the formation of clusters within the flow. We find a power law relation
+between the cluster size distribution and its probability, which indicates that
+stronger cohesion can promote the formation of larger clusters, and we discuss
+how cohesion impact on flows manifested by cluster formation.",2307.09682v1
+2023-07-19,On the equivalence between squeezing and entanglement potential for two-mode Gaussian states,"The maximum amount of entanglement achievable under passive transformations
+by continuous-variable states is called the entanglement potential. Recent work
+has demonstrated that the entanglement potential is upper-bounded by a simple
+function of the squeezing of formation, and that certain classes of two-mode
+Gaussian states can indeed saturate this bound, though saturability in the
+general case remains an open problem. In this study, we introduce a larger
+class of states that we prove saturates the bound, and we conjecture that all
+two-mode Gaussian states can be passively transformed into this class, meaning
+that for all two-mode Gaussian states, entanglement potential is equivalent to
+squeezing of formation. We provide an explicit algorithm for the passive
+transformations and perform extensive numerical testing of our claim, which
+seeks to unite the resource theories of two characteristic quantum properties
+of continuous-variable systems.",2307.10386v1
+2023-07-20,Hybrid FEM and peridynamic simulation of hydraulic fracture propagation in saturated porous media,"This paper presents a hybrid modeling approach for simulating hydraulic
+fracture propagation in saturated porous media: ordinary state-based
+peridynamics is used to describe the behavior of the solid phase, including the
+deformation and crack propagation, while FEM is used to describe the fluid flow
+and to evaluate the pore pressure. Classical Biot poroelasticity theory is
+adopted. The proposed approach is first verified by comparing its results with
+the exact solutions of two examples. Subsequently, a series of pressure- and
+fluid-driven crack propagation examples are solved and presented. The
+phenomenon of fluid pressure oscillation is observed in the fluid-driven crack
+propagation examples, which is consistent with previous experimental and
+numerical evidences. All the presented examples demonstrate the capability of
+the proposed approach in solving problems of hydraulic fracture propagation in
+saturated porous media.",2307.10929v1
+2023-07-20,Numerical simulation of forerunning fracture in saturated porous solids with hybrid FEM/Peridynamic model,"In this paper, a novel hybrid FEM and Peridynamic modeling approach proposed
+in Ni et al. (2020) is used to predict the dynamic solution of hydro-mechanical
+coupled problems. A modified staggered solution algorithm is adopted to solve
+the coupled system. A one-dimensional dynamic consolidation problem is solved
+first to validate the hybrid modeling approach, and both -convergence and
+-convergence studies are carried out to determine appropriate discretization
+parameters for the hybrid model. Thereafter, dynamic fracturing in a
+rectangular dry/fully saturated structure with a central initial crack is
+simulated both under mechanical loading and fluid-driven conditions. In the
+mechanical loading fracture case, fixed surface pressure is applied on the
+upper and lower surfaces of the initial crack near the central position to
+force its opening. In the fluid-driven fracture case, the fluid injection is
+operated at the centre of the initial crack with a fixed rate. Under the action
+of the applied external force and fluid injection, forerunning fracture
+behavior is observed both in the dry and saturated conditions.",2307.11121v1
+2023-07-31,Confidence Interval and Uncertainty Propagation Analysis of SAFT-type Equations of State,"Thermodynamic models and, in particular, SAFT-type equations are vital in
+characterizing complex systems. This paper presents a framework for sampling
+parameter distributions in PC-SAFT and SAFT-VR Mie equations of state to
+understand parameter confidence intervals and correlations. We identify
+conserved quantities contributing to significant correlations. Comparing the
+equations of state, we find that additional parameters introduced in the
+SAFT-VR Mie equation increase relative uncertainties (1\%-2\% to 3\%-4\%) and
+introduce more correlations. When incorporating association through additional
+parameters, relative uncertainties increase, but correlations slightly
+decrease. We investigate how uncertainties propagate to derived properties and
+observe small uncertainties for that data with which the parameters were
+regressed, especially for saturated-liquid volumes. However, extrapolating to
+saturated-vapour volumes yields larger uncertainties due to the larger
+isothermal compressibility. Near the critical point, uncertainties in saturated
+volumes diverge due to increased sensitivity of the isothermal compressibility
+to parameter uncertainties. This effect significantly impacts bulk properties,
+particularly isobaric heat capacity, where uncertainties near the critical
+point become extremely large, even when these uncertainties are small. We
+emphasize that even small uncertainties near the critical point lead to
+divergences in predicted properties.",2308.00171v1
+2023-08-29,Not all that is $β_0$ is $β$-function: the DGLAP resummation and the running coupling in NLO JIMWLK,"We reanalyze the origin of the large transverse logarithms associated with
+the QCD one loop beta-function coefficient in the NLO JIMWLK Hamiltonian. We
+show that some of these terms are not associated with the running of the QCD
+coupling constant but rather with the DGLAP evolution. The DGLAP-like
+resummation of these logarithms is mandatory within the JIMWLK Hamiltonian, as
+long as the color correlation length in the projectile is larger than that in
+the target. This regime in fact covers the whole range of rapidities at which
+JIMWLK evolution is supposed to be applicable. We derive the RG equation that
+resums these logarithms to all orders in alpha_s in the JIMWLK Hamiltonian.
+This is a nonlinear equation for the eikonal scattering matrix S(x). We solve
+this equation and perform the DGLAP resummation in two simple cases: the dilute
+limit, where both the projectile and the target are far from saturation, and
+the saturated regime, where the target correlation length also determines its
+saturation momentum.",2308.15545v1
+2023-09-01,A Semi-classical Spacetime Region with Maximum Entropy,"We consider a 4D spherically-symmetric static finite spacetime region as a
+collection of quanta in the semi-classical Einstein equation and study the
+entropy including the self-gravity. For sufficiently excited states, we
+estimate the entropy in a WKB-like method considering local consistency with
+thermodynamics and find its upper bound. The saturation condition uniquely
+determines the entropy-maximized spacetime as a radially uniform dense
+configuration with near-Planckian curvatures and a surface just outside the
+Schwarzschild radius. The interior metric is a non-perturbative solution in
+$\hbar$, leading to the species bound. The maximum entropy then saturates the
+Bousso bound and coincides with the Bekenstein-Hawking formula. Thus, the
+Bousso bound in this class of spacetime is verified by constructing the
+saturating configuration that has no horizon and stores information inside.",2309.00602v3
+2023-09-05,Bound-preserving discontinuous Galerkin methods for compressible two-phase flows in porous media,"This paper presents a numerical study of immiscible, compressible two-phase
+flows in porous media, that takes into account heterogeneity, gravity,
+anisotropy, and injection/production wells. We formulate a fully implicit
+stable discontinuous Galerkin solver for this system that is accurate, that
+respects the maximum principle for the approximation of saturation, and that is
+locally mass conservative. To completely eliminate the overshoot and undershoot
+phenomena, we construct a flux limiter that produces bound-preserving
+elementwise average of the saturation. The addition of a slope limiter allows
+to recover a pointwise bound-preserving discrete saturation. Numerical results
+show that both maximum principle and monotonicity of the solution are
+satisfied. The proposed flux limiter does not impact the local mass error and
+the number of nonlinear solver iterations.",2309.01908v1
+2023-09-07,Chasing Consistency in Text-to-3D Generation from a Single Image,"Text-to-3D generation from a single-view image is a popular but challenging
+task in 3D vision. Although numerous methods have been proposed, existing works
+still suffer from the inconsistency issues, including 1) semantic
+inconsistency, 2) geometric inconsistency, and 3) saturation inconsistency,
+resulting in distorted, overfitted, and over-saturated generations. In light of
+the above issues, we present Consist3D, a three-stage framework Chasing for
+semantic-, geometric-, and saturation-Consistent Text-to-3D generation from a
+single image, in which the first two stages aim to learn parameterized
+consistency tokens, and the last stage is for optimization. Specifically, the
+semantic encoding stage learns a token independent of views and estimations,
+promoting semantic consistency and robustness. Meanwhile, the geometric
+encoding stage learns another token with comprehensive geometry and
+reconstruction constraints under novel-view estimations, reducing overfitting
+and encouraging geometric consistency. Finally, the optimization stage benefits
+from the semantic and geometric tokens, allowing a low classifier-free guidance
+scale and therefore preventing oversaturation. Experimental results demonstrate
+that Consist3D produces more consistent, faithful, and photo-realistic 3D
+assets compared to previous state-of-the-art methods. Furthermore, Consist3D
+also allows background and object editing through text prompts.",2309.03599v1
+2023-09-12,Exceptional point proximity-driven mode-locking in coupled microresonators,"We show theoretically and numerically that mode-locking is feasible with a
+coupled-cavity system with gain and loss, notably, without any natural
+saturable absorber. We highlight that in the vicinity of the exceptional point,
+system $Q$ exhibits substantial modulation even with minor refractive index
+changes and a minimal Kerr effect contribution. Leveraging this unique
+behaviour, we propose an unprecedented approach wherein the lossy auxiliary
+cavity functions as an efficient artificial saturable absorber, thus
+facilitating mode-locking. This approach is not only novel, but also presents
+considerable advantages over conventional systems where both gain and saturable
+absorption are contained within a single microcavity. These benefits include
+reduced operational power and ease of post-adjustment, achievable through the
+manipulation of the coupling strength between the two microcavities.",2309.05912v1
+2023-09-20,Insights into neutron star equation of state by machine learning,"Due to its powerful capability and high efficiency in big data analysis,
+machine learning has been applied in various fields. We construct a neural
+network platform to constrain the behaviors of the equation of state of nuclear
+matter with respect to the properties of nuclear matter at saturation density
+and the properties of neutron stars. It is found that the neural network is
+able to give reasonable predictions of parameter space and provide new hints
+into the constraints of hadron interactions. As a specific example, we take the
+relativistic mean field approximation in a widely accepted Walecka-type model
+to illustrate the feasibility and efficiency of the platform. The results show
+that the neural network can indeed estimate the parameters of the model at a
+certain precision such that both the properties of nuclear matter around
+saturation density and global properties of neutron stars can be saturated. The
+optimization of the present modularly designed neural network and extension to
+other effective models are straightforward.",2309.11227v1
+2023-09-30,Optimal Local Measurements in Many-body Quantum Metrology,"Quantum measurements are key to quantum metrology. Constrained by
+experimental capabilities, collective measurements on a large number of copies
+of metrological probes can pose significant challenges. Therefore, the locality
+in quantum measurements must be considered. In this work, we propose a method
+dubbed as the ""iterative matrix partition"" approach to elucidate the underlying
+structures of optimal local measurements, with and without classical
+communications, that saturate the quantum Cram\'er-Rao Bound (qCRB).
+Furthermore, we find that while exact saturation is possible for all two-qubit
+pure states, it is generically restrictive for multi-qubit pure states.
+However, we demonstrate that the qCRB can be universally saturated in an
+approximate manner through adaptive coherent controls, as long as the initial
+state is separable and the Hamiltonian allows for interaction. Our results
+bridge the gap between theoretical proposals and experiments in many-body
+metrology and can find immediate applications in noisy intermediate-scale
+quantum devices.",2310.00285v1
+2023-09-30,Optimal Control of Grid-Interfacing Inverters With Current Magnitude Limits,"Grid-interfacing inverters act as the interface between renewable resources
+and the electric grid, and have the potential to offer fast and programmable
+controls compared to synchronous generators. With this flexibility there has
+been significant research efforts into determining the best way to control
+these inverters. Inverters are limited in their maximum current output in order
+to protect semiconductor devices, presenting a nonlinear constraint that needs
+to be accounted for in their control algorithms. Existing approaches either
+simply saturate a controller that is designed for unconstrained systems, or
+assume small perturbations and linearize a saturated system. These approaches
+can lead to stability issues or limiting the control actions to be too
+conservative.
+  In this paper, we directly focus on a nonlinear system that explicitly
+accounts for the saturation of the current magnitude. We use a Lyapunov
+stability approach to determine a stability condition for the system,
+guaranteeing that a class of controllers would be stabilizing if they satisfy a
+simple SDP condition. With this condition we fit a linear-feedback controller
+by sampling the output (offline) model predictive control problems. This
+learned controller has improved performances with existing designs.",2310.00473v2
+2023-10-07,A Polynomial Upper Bound for Poset Saturation,"Given a finite poset $\mathcal P$, we say that a family $\mathcal F$ of
+subsets of $[n]$ is $\mathcal P$-saturated if $\mathcal F$ does not contain an
+induced copy of $\mathcal P$, but adding any other set to $\mathcal F$ creates
+an induced copy of $\mathcal P$. The induced saturation number of $\mathcal P$,
+denoted by $\text{sat}^*(n,\mathcal P)$, is the size of the smallest $\mathcal
+P$-saturated family with ground set $[n]$. In this paper we prove that the
+saturation number for any given poset grows at worst polynomially. More
+precisely, we show that $\text{sat}^*(n, \mathcal P)=O(n^c)$, where
+$c\leq|\mathcal{P}|^2/4+1$ is a constant depending on $\mathcal P$ only. We
+obtain this result by bounding the VC-dimension of our family.",2310.04634v1
+2023-10-20,Transfer systems for rank two elementary Abelian groups: characteristic functions and matchstick games,"We prove that Hill's characteristic function $\chi$ for transfer systems on a
+lattice $P$ surjects onto interior operators for $P$. Moreover, the fibers of
+$\chi$ have unique maxima which are exactly the saturated transfer systems. In
+order to apply this theorem in examples relevant to equivariant homotopy
+theory, we develop the theory of saturated transfer systems on modular
+lattices, ultimately producing a ``matchstick game'' that puts saturated
+transfer systems in bijection with certain structured subsets of covering
+relations. After an interlude developing a recursion for transfer systems on
+certain combinations of bounded posets, we apply these results to determine the
+full lattice of transfer systems for rank two elementary Abelian groups.",2310.13835v1
+2023-10-22,Characterizing the heterogeneity of membrane liquid-ordered domains,"We use a lattice model of a ternary mixture containing saturated and
+unsaturated lipids with cholesterol (Chol), to study the structural properties
+characterizing the coexistence between the liquid-disordered and liquid-ordered
+phases. Depending on the affinity of the saturated and unsaturated lipids, the
+system may exhibit macroscopic (thermodynamic) liquid-liquid phase separation,
+or be divided into small-size liquid-ordered domains surrounded by a
+liquid-disordered matrix. In both cases, it is found that the nano-scale
+structure of the liquid-ordered regions is heterogeneous, and that they are
+partitioned into Chol-rich sub-domains and Chol-free, gel-like, nano-clusters.
+This emerges as a characteristic feature of the liquid-ordered state, which
+helps distinguishing between liquid-ordered domains in a two-phase mixture, and
+similar-looking domains in a one-phase mixture that are rich in saturated
+lipids and Chol, but are merely thermal density fluctuations. The
+nano-structure heterogeneity of the liquid-ordered phase can be detected by
+suitable experimental spectroscopic methods, and is observed also in atomistic
+computer simulations.",2310.14316v1
+2023-11-03,Forward dijet production at the LHC within an impact parameter dependent TMD approach,"We investigate possible signatures of gluon saturation using forward $p+A \to
+j+j+X$ di-jet production processes at the Large Hadron Collider. In the forward
+rapidity region, this is a highly asymmetric process where partons with large
+longitudinal momentum fraction \(x\) in the dilute projectile are used as a
+probe to resolve the small \(x\) partonic content of the dense target. Such
+dilute-dense processes can be described in the factorization framework of
+Improved Transverse Momentum Distributions (ITMDs). We present a new model for
+ITMDs where we explicitly introduce the impact parameter (\(b\)) dependence in
+the ITMDs, to properly account for the nuclear enhancement of gluon saturation
+effects, and discuss the phenomenological consequences for $p-Pb$, $p-Xe$ and
+$p-O$ collisions at the LHC. While the case of $p-p$ and $e-p$ collisions is
+used to fix the model parameters, we find that, on average, the nuclear
+enhancement of the saturation scale is noticeably weaker than expected from
+naive scaling with a simple dependence on the atomic number. Since our model
+explicitly accounts for event-by-event fluctuations of the nuclear geometry, it
+can also be applied to study forward central correlations in $p-A$ collisions.",2311.01965v2
+2023-11-28,Transverse Energy-Energy Correlators in the Color-Glass Condensate at the Electron-Ion Collider,"We investigate the transverse energy-energy correlators (TEEC) in the
+small-$x$ regime at the upcoming Electron-Ion Collider (EIC). Focusing on the
+back-to-back production of electron-hadron pairs in both $ep$ and $eA$
+collisions, we establish a factorization theorem given in terms of the hard
+function, quark distributions, soft functions, and TEEC jet functions, where
+the gluon saturation effect is incorporated. Numerical results for TEEC in both
+$ep$ and $eA$ collisions are presented, together with the nuclear modification
+factor $R_A$. Our analysis reveals that TEEC observables in deep inelastic
+scattering provide a valuable approach for probing gluon saturation phenomena.
+Our findings underscore the significance of measuring TEEC at the EIC,
+emphasizing its efficacy in advancing our understanding of gluon saturation and
+nuclear modifications in high-energy collisions.",2311.17142v1
+2023-12-06,Low-momentum relativistic nucleon-nucleon potentials I: Nuclear matter,"A series of relativistic one-boson-exchange potentials for two-nucleon
+system, denoted as OBEP$\Lambda$, is constructed with a momentum cutoff
+$\Lambda$ ranging from $\infty$ to 2 fm$^{-1}$. These potentials are developed
+by simultaneous fitting to nucleon-nucleon ($NN$) scattering phase shifts,
+low-energy scattering length, effective range, and the binding energy of the
+deuteron. The momentum-space matrix elements of the low-momentum OBEP$\Lambda$
+($\Lambda\leqslant 3$ fm$^{-1}$) demonstrate consistency with the universal
+behaviors observed in other realistic $NN$ potentials evolved by
+renormalization group methods. These OBEP$\Lambda$s are applied to calculate
+the equation of state of symmetric nuclear matter (SNM) within either the
+nonrelativistic (NR) Brueckner-Hartree-Fock (BHF) or relativistic
+Brueckner-Hartree-Fock (RBHF) frameworks. The results show that the saturation
+properties of SNM are reproduced qualitatively from the RBHF calculation, but
+not from the NR-BHF calculation. This study highlights the relativistic
+mechanism in explaining the saturation properties of nuclear matter. The
+remaining discrepancy in reproducing empirical saturation properties in the
+RBHF calculation using the OBEP$\Lambda$s signals the necessity of including
+three-nucleon correlations or genuine three-nucleon forces.",2312.03403v1
+2023-12-07,Direct data-driven control of input saturated systems: a LMI-based approach,"In this paper, we revisit three intricate control challenges in the context
+of input-saturated systems, adopting a direct data-driven perspective.
+Diverging from the traditional two-stage process involving system
+identification and model-based control, our approach dispenses with the need
+for an explicit model description. By harnessing a combination of data-based
+closed-loop representation, Lyapunov theory, instrumental variables, and a
+generalized sector condition, we formulate data-driven linear matrix
+inequalities (LMIs). These LMIs are employed to maximize the basin of
+attraction, minimize the closed-loop reachable set with bounded disturbances,
+and propose a new data-driven $\ell_2$-gain minimization. Through
+demonstrations on benchmark examples, we shed light on the merits and
+limitations of transitioning from indirect to direct design strategies for
+input-saturated plants, emphasizing notable advantages in handling nonlinear
+dynamics.",2312.04272v2
+2023-12-12,Purcell enhanced emission and saturable absorption of cavity-coupled CsPbBr$_3$ quantum dots,"Halide perovskite semiconductors have emerged as promising materials for the
+development of solution-processed, scalable, high performance optoelectronic
+devices such as light-emitting diodes (LEDs) as well as coherent single photon
+emitters. Their integration to nanophotonic cavities for radiative enhancement
+and strong nonlinearity is underexplored. In this work, we demonstrate
+cavity-enhanced emission and saturable absorption using colloidal CsPbBr$_3$
+perovskite quantum dots coupled to a high-Q cavity mode of a circular Bragg
+grating structure designed to facilitate integration of solution-processed
+materials . We achieve an order of magnitude increase in brightness and 8-fold
+increase in the spontaneous emission rate for the cavity-coupled emitters. This
+result indicates the possibility of achieving transform-limited photon
+coherence for the halide perovskites at cryogenic temperatures. We also observe
+saturable absorption of the emitters through intensity-dependent cavity quality
+factor. These results pave the way towards achieving improved photon
+indistinguishability and strong optical nonlinearities for cavity coupled
+perovskite systems.",2312.07800v1
+2023-12-24,On corrugation mode radial wavelengths of the vertical shear instability,"The vertical shear instability (VSI) is a promising mechanism to drive
+turbulence in protoplanetary disks. Numerical simulations in the literature
+demonstrate that the VSI non-linear saturation is predominated by the linear
+corrugation modes. These modes possess vertical wavelengths crucially longer
+than radial wavelengths. This paper aims to investigate the natural radial
+wavelength of corrugation modes upon VSI saturation, by a series of numerical
+simulations conducted in Athena++ at different grid resolutions, disk aspect
+ratios, and viscosity parameterized by $\nu$. We find a sign of convergence
+emerges at 64 cells per gas scale height for fiducial simulations, below which
+a continuous reduction of wavelengths with grid resolution is observed.
+Synthetic ALMA molecular line observations of $^{12}\rm CO(2-1)$ are performed
+to inspect the observability of the corrugation modes feature, which is
+significantly diminished with more than 32 cells per scale height. Flared and
+viscous disks, exhibiting longer saturation wavelengths, may mitigate the
+observational difficulty.",2312.15414v2
+2023-12-26,Sliding Mode Control for 3-D Uncalibrated and Constrained Vision-based Shape Servoing within Input Saturation,"This paper designs a servo control system based on sliding mode control for
+the shape control of elastic objects. In order to solve the effect of
+non-smooth and asymmetric control saturation, a Gaussian-based continuous
+differentiable asymmetric saturation function is used for this goal. The
+proposed detection approach runs in a highly real-time manner. Meanwhile, this
+paper uses sliding mode control to prove that the estimation stability of the
+deformation Jacobian matrix and the system stability of the controller are
+combined, which verifies the control stability of the closed-loop system
+including estimation. Besides, an integral sliding mode function is designed to
+avoid the need for second-order derivatives of variables, which enhances the
+robustness of the system in actual situations. Finally, the Lyapunov theory is
+used to prove the consistent final boundedness of all variables of the system.",2312.16048v1
+2024-01-21,Weak rainbow saturation numbers of graphs,"For a fixed graph $H$, we say that an edge-colored graph $G$ is \emph{weakly
+$H$-rainbow saturated} if there exists an ordering $e_1, e_2, \ldots, e_m$ of
+$E\left(\overline{G}\right)$ such that, for any list $c_1, c_2, \ldots, c_m$ of
+pairwise distinct colors from $\mathbb{N}$, the non-edges $e_i$ in color $c_i$
+can be added to $G$, one at a time, so that every added edge creates a new
+rainbow copy of $H$. The \emph{weak rainbow saturation number} of $H$, denoted
+by $rwsat(n,H)$, is the minimum number of edges in a weakly $H$-rainbow
+saturated graph on $n$ vertices. In this paper, we show that for any non-empty
+graph $H$, the limit $\lim_{n\to \infty} \frac{rwsat(n, H)}{n}$ exists. This
+answers a question of Behague, Johnston, Letzter, Morrison and Ogden [{\it SIAM
+J. Discrete Math.} (2023)]. We also provide lower and upper bounds on this
+limit, and in particular, we show that this limit is nonzero if and only if $H$
+contains no pendant edges.",2401.11525v1
+2024-01-30,Coherent $γ^*$-nucleus scattering and coherent nuclear states,"In the context of a McLerran-Venugopalan (MV) model for a large nucleus,
+coherent scattering of a virtual photon on that nucleus is evaluated in the
+$A_-=0$ gauge, the gauge appropriate for the target nucleus. The evaluation of
+the scattering in $A_-=0$ gauge is very intricate compared to the usual $A_+=0$
+gauge evaluation natural for the scattering process, but has the advantage of
+directly giving the scattering in terms of a partonic description of the
+nucleus. In the limit where a tagged forward jet puts the dipole-nucleus
+scattering in the saturation regime the coherent reactions are equal to the
+inelastic reactions. In terms of the nuclear wave function the coherent
+reactions come from color singlet and zero total transverse momentum
+quark-antiquark pairs in the wave function and in the saturation regime the
+nuclear wave function is a coherent state for these pairs. In the saturation
+region half of all quarks (or antiquarks) come from zero momentum and color
+charge pairs.",2401.17087v1
+2024-02-21,Linearity of the co-moving velocity,"The co-moving velocity is a new variable in the description of immiscible
+two-phase flow in porous media. It is the saturation-weighted average over the
+derivatives of the seepage velocities of the two immiscible fluids with respect
+to saturation. Based on analysis of relative permeability data and
+computational modeling, it has been proposed that the co-moving velocity is
+linear when plotted against the derivative of the average seepage velocity with
+respect to the saturation, the flow derivative. I show here that it is enough
+to demand that the co-moving velocity is characterized by an additive parameter
+in addition to the flow derivative to be linear. This has profound consequences
+for relative permeability theory as it leads to a differential equation
+relating the two relative permeabilities describing the flow. I present this
+equation together with two solutions.",2402.13826v2
+2024-02-23,Logarithmic A$_{\rm inf}$-cohomology,"We extend the construction of A$_{\rm inf}$-cohomology by
+Bhatt-Morrow-Scholze to the context of log $p$-adic formal schemes over a log
+perfectoid base. In particular, using coordinates, we prove comparison theorems
+between log A$_{\rm inf}$-cohomology with other $p$-adic cohomology theories,
+including log de Rham, log (q-)crystalline, log prismatic, and Kummer \'etale
+cohomology, as well as the derived A$_{\rm inf}$-cohomology of certain infinite
+root stacks. Along the way, we define and give a combinatorial characterization
+of a new class of maps between saturated log schemes, called pseudo-saturated
+maps, which is of independent interest. They are related to (and slightly
+weaker than) the notion of quasi-saturated maps and maps of Cartier type
+studied by Tsuji.",2402.15154v1
+2024-02-23,Safety-Conscious Pushing on Diverse Oriented Surfaces with Underactuated Aerial Vehicles,"Pushing tasks performed by aerial manipulators can be used for contact-based
+industrial inspections. Underactuated aerial vehicles are widely employed in
+aerial manipulation due to their widespread availability and relatively low
+cost. Industrial infrastructures often consist of diverse oriented work
+surfaces. When interacting with such surfaces, the coupled gravity compensation
+and interaction force generation of underactuated aerial vehicles can present
+the potential challenge of near-saturation operations. The blind utilization of
+these platforms for such tasks can lead to instability and accidents, creating
+unsafe operating conditions and potentially damaging the platform. In order to
+ensure safe pushing on these surfaces while managing platform saturation, this
+work establishes a safety assessment process. This process involves the
+prediction of the saturation level of each actuator during pushing across
+variable surface orientations. Furthermore, the assessment results are used to
+plan and execute physical experiments, ensuring safe operations and preventing
+platform damage.",2402.15243v1
+2024-02-29,Getting Saturated with Induction,"Induction in saturation-based first-order theorem proving is a new exciting
+direction in the automation of inductive reasoning. In this paper we survey our
+work on integrating induction directly into the saturation-based proof search
+framework of first-order theorem proving. We describe our induction inference
+rules proving properties with inductively defined datatypes and integers. We
+also present additional reasoning heuristics for strengthening inductive
+reasoning, as well as for using induction hypotheses and recursive function
+definitions for guiding induction. We present exhaustive experimental results
+demonstrating the practical impact of our approach as implemented within
+Vampire.
+  This is an extended version of a Principles of Systems Design 2022 paper with
+the same title and the same authors.",2402.18954v1
+2024-02-29,Program Synthesis in Saturation,"We present an automated reasoning framework for synthesizing recursion-free
+programs using saturation-based theorem proving. Given a functional
+specification encoded as a first-order logical formula, we use a first-order
+theorem prover to both establish validity of this formula and discover program
+fragments satisfying the specification. As a result, when deriving a proof of
+program correctness, we also synthesize a program that is correct with respect
+to the given specification. We describe properties of the calculus that a
+saturation-based prover capable of synthesis should employ, and extend the
+superposition calculus in a corresponding way. We implemented our work in the
+first-order prover Vampire, extending the successful applicability of
+first-order proving to program synthesis.
+  This is an extended version of an Automated Deduction -- CADE 29 paper with
+the same title and the same authors.",2402.18962v1
+2024-03-14,Compactness of quantics tensor train representations of local imaginary-time propagators,"Space-time dependence of imaginary-time propagators, vital for \textit{ab
+initio} and many-body calculations based on quantum field theories, has been
+revealed to be compressible using Quantum Tensor Trains (QTTs) [Phys. Rev. X
+{\bf 13}, 021015 (2023)]. However, the impact of system parameters, like
+temperature, on data size remains underexplored. This paper provides a
+comprehensive numerical analysis of the compactness of local imaginary-time
+propagators in QTT for one-time/-frequency objects and two-time/-frequency
+objects, considering truncation in terms of the Frobenius and maximum norms. We
+employ random pole models to study worst-case scenarios. The numerical analysis
+reveals several key findings. For one-time/-frequency objects and
+two-time/-frequency objects, the bond dimensions saturate at low temperatures,
+especially for truncation in terms of the Frobenius norm. We provide
+counting-number arguments for the saturation of bond dimensions for the
+one-time/-frequency objects, while the origin of this saturation for
+two-time/-frequency objects remains to be clarified. This paper's findings
+highlight the critical need for further research on the selection of truncation
+methods, tolerance levels, and the choice between imaginary-time and
+imaginary-frequency representations in practical applications.",2403.09161v1
+2024-03-22,Proper Rainbow Saturation Numbers for Cycles,"We say that an edge-coloring of a graph $G$ is proper if every pair of
+incident edges receive distinct colors, and is rainbow if no two edges of $G$
+receive the same color. Furthermore, given a fixed graph $F$, we say that $G$
+is rainbow $F$-saturated if $G$ admits a proper edge-coloring which does not
+contain any rainbow subgraph isomorphic to $F$, but the addition of any edge to
+$G$ makes such an edge-coloring impossible. The maximum number of edges in a
+rainbow $F$-saturated graph is the rainbow Tur\'an number, whose study was
+initiated in 2007 by Keevash, Mubayi, Sudakov, and Verstra\""ete. Recently,
+Bushaw, Johnston, and Rombach introduced study of a corresponding saturation
+problem, asking for the minimum number of edges in a rainbow $F$-saturated
+graph. We term this minimum the proper rainbow saturation number of $F$,
+denoted $\mathrm{sat}^*(n,F)$. We asymptotically determine
+$\mathrm{sat}^*(n,C_4)$, answering a question of Bushaw, Johnston, and Rombach.
+We also exhibit constructions which establish upper bounds for
+$\mathrm{sat}^*(n,C_5)$ and $\mathrm{sat}^*(n,C_6)$.",2403.15602v1
+2009-08-10,Tunnel magnetoresistance of magnetic junctions with cubic symmetry of the layers,"A tunnel magnetic junction is considered with magnetic hard and magnetic soft
+layers of cubic symmetry. The magnetic switching is analyzed of the layers by a
+magnetic field perpendicular to the initial magnetizations. In such a
+situation, an additional peak of the TMR ratio appears at the magnetic field
+value lower substantially than the anisotropy energy of the soft layer.",0908.1278v1
+2014-09-03,Photo-induced Magnetic Force Between Nanostructures,"Photo-induced magnetic force between nanostructures, at optical frequencies,
+is investigated theoretically. Till now optical magnetic effects are not used
+in scanning probe microscopy because of the vanishing natural magnetism with
+increasing frequency. On the other hand, artificial magnetism in engineered
+nanostructures led to the development of measurable optical magnetism. Here,
+two examples of nanoprobes that are able to generate strong magnetic dipolar
+fields at optical frequency are investigated: first an ideal magnetically
+polarizable nanosphere and then a circular cluster of silver nanospheres that
+has a loop-like collective plasmonic resonance equivalent to a magnetic dipole.
+Magnetic forces are evaluated based on nanostructure polarizabilities, i.e.
+induced magnetic dipoles, and magnetic-near field evaluations. As an initial
+assessment on the possibility of a magnetic nanoprobe to detect magnetic
+forces, we consider two identical magnetically polarizable nanoprobes and
+observe magnetic forces in the order of piconewtons thereby bringing it within
+detection limits of conventional atomic force microscopes at ambient pressure
+and temperature. The detection of magnetic force is a promising method in
+studying optical magnetic transitions that can be the basis of innovative
+spectroscopy applications.",1409.1188v2
+2021-03-10,Searching for Magnetic Monopoles with the Earth's Magnetic Field,"Magnetic monopoles have long been predicted in theory and could exist as a
+stable object in our universe. As they move around in galaxies, magnetic
+monopoles could be captured by astrophysical objects like stars and planets.
+Here, we provide a novel method to search for magnetic monopoles by detecting
+the monopole moment of the Earth's magnetic field. Using over six years of
+public geomagnetic field data obtained by the Swarm satellites, we apply
+Gauss's law to measure the total magnetic flux, which is proportional to the
+total magnetic charge inside the Earth. To account for the secular variation of
+satellite altitudes, we define an altitude-rescaled magnetic flux to reduce the
+dominant magnetic dipole contribution. The measured magnetic flux is consistent
+with the existing magnetic field model that does not contain a monopole moment
+term. We therefore set an upper limit on the magnetic field strength at Earth's
+surface from magnetic monopoles to be $|B_{\rm m}| < 0.13$ nT at 95% confidence
+level, which is less than $2\times 10^{-6}$ of Earth's magnetic field strength.
+This constrains the abundance of magnetically-charged objects, including
+magnetic black holes with large magnetic charges.",2103.06286v1
+2007-05-31,Geometry-induced frustration of magnetization in a planar soft-hard magnetic system,"We computationally study the frustrated magnetic configurations of a thin
+soft magnetic layer with the boundary condition fixed by underlying hard
+magnets. Driven by geometrical constraints and external magnetic field,
+transitions between frustrated energy minima result in magnetic hysteretic
+behavior. The presence of soft-magnet introduces strong undulations in the
+energy landscape in a length scale set by the magnetic property of the soft
+magnet. We propose a possible use of the phenomena to locally control the
+movement of magnetic nanoparticles.",0705.4490v1
+2014-05-19,Scaling laws of free magnetic energy stored in a solar emerging flux region,"This Letter reports scaling laws of free magnetic energy stored in a solar
+emerging flux region which is a key to understanding the energetics of solar
+active phenomena such as solar flares and coronal mass ejections. By performing
+3-dimensional magnetohydrodynamic simulations that reproduce several emerging
+flux regions of different magnetic configurations, we derive power law
+relationships among emerged magnetic flux, free magnetic energy and relative
+magnetic helicity in these emerging flux regions. Since magnetic flux is an
+observable quantity, the scaling law between magnetic flux and free magnetic
+energy may give a way to estimate invisible free magnetic energy responsible
+for solar active phenomena.",1405.4587v1
+2020-09-24,Magnetic winding: what is it and what is it good for?,"Magnetic winding is a fundamental topological quantity that underpins
+magnetic helicity and measures the entanglement of magnetic field lines. Like
+magnetic helicity, magnetic winding is also an invariant of ideal
+magnetohydrodynamics. In this article we give a detailed description of what
+magnetic winding describes, how to calculate it and how to interpret it in
+relation to helicity. We show how magnetic winding provides a clear topological
+description of magnetic fields (open or closed) and we give examples to show
+how magnetic winding and helicity can behave differently, thus revealing
+different and imporant information about the underlying magnetic field.",2009.11708v1
+2022-10-31,HTS Dipole Magnet with a Mechanical Energy Transfer in the Magnetic Field,"There were designed and successfully tested at Fermilab several high
+temperature superconducting (HTS) model magnets for particle accelerators. Some
+of them worked in a persistent current mode continuously generating magnetic
+field in the iron dominated magnet gap. In the paper was investigated a novel
+HT dipole magnet concept with a mechanical energy transfer in the magnetic
+field. To pump the energy in the superconducting HTS dipole magnet used a
+detachable magnetizer. The HTS dipole magnet was build and successfully tested
+at a liquid nitrogen temperature. Discussed the magnet design, test results,
+the proposed approach limits, and efficiency.",2211.00105v1
+2023-08-03,Magnetic interactions in IV-VI diluted magnetic semiconductors,"Diluted magnetic semiconductors (DMS) are interesting because of the
+interplay between the electronic and magnetic subsystems. We describe selected
+magnetic properties of IV-VI diluted magnetic semiconductors, looking at the
+similarities and differences between magnetic properties of II-VI, IV-VI, and
+III-V DMS. We focus on the influence of the crystalline and electronic
+structure of the material on its magnetic properties, especially on the
+exchange interactions among magnetic ions. We describe methods of determination
+of the exchange parameters by using different experimental techniques, such as
+measurements of magnetic susceptibility, magnetization, and specific heat. We
+follow the development in the material technology from bulk crystals to thin
+films and nanostructures.",2308.01780v1
+2009-05-27,Higher-order effects on the incompressibility of isospin asymmetric nuclear matter,"Analytical expressions for the saturation density as well as the binding
+energy and incompressibility at the saturation density of asymmetric nuclear
+matter are given exactly up to 4th-order in the isospin asymmetry delta =(rho_n
+- rho_p)/rho using 11 characteristic parameters defined at the normal nuclear
+density rho_0. Using an isospin- and momentum-dependent modified Gogny (MDI)
+interaction and the SHF approach with 63 popular Skyrme interactions, we have
+systematically studied the isospin dependence of the saturation properties of
+asymmetric nuclear matter, particularly the incompressibility $K_{sat}(\delta
+)=K_{0}+K_{sat,2}\delta ^{2}+K_{sat,4}\delta ^{4}+O(\delta ^{6})$ at the
+saturation density. Our results show that the magnitude of the high-order
+$K_{sat,4}$ parameter is generally small compared to that of the $K_{\sat,2}$
+parameter. The latter essentially characterizes the isospin dependence of the
+incompressibility at the saturation density and can be expressed as
+$K_{sat,2}=K_{sym}-6L-\frac{J_{0}}{K_{0}}L$, Furthermore, we have constructed a
+phenomenological modified Skyrme-like (MSL) model which can reasonably describe
+the general properties of symmetric nuclear matter and the symmetry energy
+predicted by both the MDI model and the SHF approach. The results indicate that
+the high-order $J_{0}$ contribution to $K_{sat,2}$ generally cannot be
+neglected. In addition, it is found that there exists a nicely linear
+correlation between $K_{sym}$ and $L$ as well as between $J_{0}/K_{0}$ and
+$K_{0}$. These correlations together with the empirical constraints on $K_{0}$,
+$L$, $E_{sym}(\rho_{0})$ and the nucleon effective mass lead to an estimate of
+$K_{sat,2}=-370\pm 120$ MeV.",0905.4323v2
+2013-07-02,Impact-parameter dependent Color Glass Condensate dipole model and new combined HERA data,"The Impact-Parameter dependent Color Glass Condensate (b-CGC) dipole model is
+based on the Balitsky-Kovchegov non-linear evolution equation and improves the
+Iancu-Itakura-Munier dipole model by incorporating the impact-parameter
+dependence of the saturation scale. Here we confront the model to the recently
+released high precision combined HERA data and obtain its parameters. The b-CGC
+results are then compared to data at small-x for the structure function, the
+longitudinal structure function, the charm structure function, exclusive vector
+meson (J/\psi, \phi, \rho) production and Deeply Virtual Compton Scattering
+(DVCS). We also compare our results with the Impact-Parameter dependent
+Saturation model (IP-Sat). We show that most features of inclusive DIS and
+exclusive diffractive data, including the Q^2, W, |t| and x dependence are
+correctly reproduced in both models. Nevertheless, the b-CGC and the IP-Sat
+models give different predictions beyond the current HERA kinematics, namely
+for the structure functions at very low x and high virtualities Q^2, and for
+the exclusive diffractive vector meson and DVCS production at high t. This can
+be traced back to the different power-law behavior of the saturation scale in
+x, and to a different impact-parameter b dependence of the saturation scale in
+these models. Nevertheless, both models give approximately similar saturation
+scale Q_S<1 GeV for the proton in HERA kinematics, and also both models lead to
+the same conclusion that the typical impact-parameter probed in the total
+\gamma^{*}p cross-section is about b\approx 2\div 3 GeV^{-1}. Our results
+provide a benchmark for further investigation of QCD at small-x in heavy ion
+collisions at RHIC and the LHC and also at future experiments such as an
+Electron-Ion Collider and the LHeC.",1307.0825v3
+2013-10-25,High Energy Collisions of Dense Hadrons in Quantum Chromodynamics : LHC Phenomenology and Universality of Parton Distributions,"As the value of the longitudinal momentum carried by partons in a
+ultra-relativistic hadron becomes small, one observes a growth of their
+density. When the parton density becomes close to a value of order
+$1/\alpha_s$, it does not grow any longer, it saturates. These high density
+effects seem to be well described by the Color Glass Condensate effective field
+theory. On the experimental side, the LHC provides the best tool ever for
+reaching the saturated phase of hadronic matter. For this reason saturation
+physics is a very active branch of QCD during these past and coming years since
+saturation theories and experimental data can be compared. I first deal with
+the phenomenology of the proton-lead collisions performed in winter 2013 at the
+LHC and whose data are about to be available. I compute the di-gluon production
+cross-section which provides the simplest observable for finding quantitative
+evidences of saturation in the kinematic range of the LHC. I also discuss the
+limit of the strongly correlated final state at large transverse momenta and by
+the way, generalize parton distribution to dense regime. The second main topic
+is the quantum evolution of the quark and gluon spectra in nucleus-nucleus
+collisions having in mind the proof of its universal character. This result is
+already known for gluons and here I detail the calculation carefully. For
+quarks universality has not been proved yet but I derive an intermediate
+leading order to next-to leading order recursion relation which is a crucial
+step for extracting the quantum evolution. Finally I briefly present an
+independent work in group theory. I detail a method I used for computing traces
+involving an arbitrary number of group generators, a situation often
+encountered in QCD calculations.",1310.6935v4
+2015-05-14,Sharp bounds on the radius of relativistic charged spheres: Guilfoyle's stars saturate the Buchdahl-Andréasson bound,"Buchdahl, by imposing a few physical assumptions on the matter, i.e., its
+density is a nonincreasing function of the radius and the fluid is a perfect
+fluid, and on the configuration, such as the exterior is the Schwarzschild
+solution, found that the radius $r_0$ to mass $m$ ratio of a star would obey
+the Buchdahl bound $r_0/m\geq9/4$. He noted that the bound was saturated by the
+Schwarzschild interior solution, the solution with $\rho_{\rm m}(r)= {\rm
+constant}$, where $\rho_{\rm m}(r)$ is the energy density of the matter at $r$,
+when the central central pressure blows to infinity. Generalizations of this
+bound have been studied. One generalization was given by Andr\'easson by
+including electrically charged matter and imposing that $p+2p_T \leq\rho_{\rm
+m}$, where $p$ is the radial pressure and $p_T$ the tangential pressure. His
+bound is given by $r_0/m\geq9/\left(1+\sqrt{1+3\,q^2/r_0^2}\right)^{2}$, the
+Buchdahl-Andr\'easson bound, with $q$ being the star's total electric charge.
+Following Andr\'easson's proof, the configuration that saturates the Buchdahl
+bound is an uncharged shell, rather than the Schwarzschild interior solution.
+By extension, the configurations that saturate the Buchdahl-Andr\'easson bound
+are charged shells. One expects then, in turn, that there should exist an
+electrically charged equivalent to the interior Schwarzschild limit. We find
+here that this equivalent is provided by the equation $\rho_{\rm m}(r) +
+{Q^2(r)}/ {\left(8\pi\,r^4\right)}= {\rm constant}$, where $Q(r)$ is the
+electric charge at $r$. This equation was put forward by Cooperstock and de la
+Cruz, and Florides, and realized in Guilfoyle's stars. When the central
+pressure goes to infinity Guilfoyle's stars are configurations that saturate
+the Buchdahl-Andr\'easson bound. It remains to find a proof in Buchdahl's
+manner such that these configurations are the limiting configurations of the
+bound.",1505.03863v1
+2015-06-14,CO$_2$ dissolution in a background hydrological flow,"We investigate the long time steady-state dissolution of CO$_{2}$ in a deep
+saline aqquifer in the presence of a background hydrological flow. In
+steady-state, the distribution of CO$_2$ in the groundwater upstream of the
+aquifer involves a balance between three competing effects: (i) the
+buoyancy-driven flow of CO$_2$ saturated water; (ii) the diffusion of CO$_2$
+from saturated to under-saturated water; and (iii) the advection associated
+with the oncoming background flow. This leads to three limiting regimes. In the
+limit of very slow diffusion, a nearly static intrusion of dense fluid may
+extend a finite distance upstream, balanced by the pressure gradient associated
+with the oncoming background flow. In the limit of fast diffusion relative to
+the flow, a gradient zone may become established in which the along aquifer
+diffusive flux balances the advection associated with the background flow.
+However, if the buoyancy-driven flow speed exceeds the background hydrological
+flow speed, then a third, intermediate regime may become established. In this
+regime, a convective recirculation develops upstream of the anticline involving
+the vertical diffusion of CO$_2$ from an upstream propagating flow of dense
+CO$_2$ saturated water into the downstream propagating flow of CO$_2$
+unsaturated water. For each limiting case, we find analytical solutions for the
+distribution of CO$_2$ upstream of the anticline, and test our analysis with
+full numerical simulations. A key result is that, although there may be very
+different controls on the distribution and extent of CO$_2$ bearing water
+upstream of the anticline, in each case the dissolution rate is given by the
+product of the background volume flux and the difference in concentration
+between the CO$_2$ saturated water and the original aquifer water upstream.",1506.04433v2
+2016-02-02,Conductance saturation in a series of highly transmitting molecular junctions,"Understanding the properties of electronic transport across metal-molecule
+interfaces is of central importance for controlling a large variety of
+molecular-based devices such as organic light emitting diodes, nanoscale
+organic spin-valves and single-molecule switches. One of the primary
+experimental methods to reveal the mechanisms behind electronic transport
+through metal-molecule interfaces is the study of conductance as a function of
+molecule length in molecular junctions. Previous studies focused on transport
+governed either by tunneling or hopping, both at low conductance. However, the
+upper limit of conductance across molecular junctions has not been explored,
+despite the great potential for efficient information transfer, charge
+injection and recombination processes. Here, we study the conductance
+properties of highly transmitting metal-molecule-metal interfaces, using a
+series of single-molecule junctions based on oligoacenes with increasing
+length. We find that the conductance saturates at an upper limit where it is
+independent of molecule length. Furthermore, we show that this upper limit can
+be controlled by the character of the orbital hybridization at the
+metal-molecule interface. Using two prototype systems, in which the molecules
+are contacted by either Ag or Pt electrodes, we reveal two different origins
+for the saturation of conductance. In the case of Ag-based molecular junctions,
+the conductance saturation is ascribed to a competition between energy level
+alignment and level broadening, while in the case of Pt-based junctions, the
+saturation is attributed to a band-like transport. The results are explained by
+an intuitive model, backed by ab-initio transport calculations. Our findings
+shed light on the mechanisms that constrain the conductance at the high
+transmission limit, providing guiding principles for the design of highly
+conductive metal-molecule interfaces.",1602.00956v1
+2016-10-19,Do fast stellar centroiding methods saturate the Cramér-Rao lower bound?,"One of the most demanding tasks in astronomical image processing---in terms
+of precision---is the centroiding of stars. Upcoming large surveys are going to
+take images of billions of point sources, including many faint stars, with
+short exposure times. Real-time estimation of the centroids of stars is crucial
+for real-time PSF estimation, and maximal precision is required for
+measurements of proper motion.
+  The fundamental Cram\'{e}r-Rao lower bound sets a limit on the
+root-mean-squared-error achievable by optimal estimators. In this work, we aim
+to compare the performance of various centroiding methods, in terms of
+saturating the bound, when they are applied to relatively low signal-to-noise
+ratio unsaturated stars assuming zero-mean constant Gaussian noise. In order to
+make this comparison, we present the ratio of the root-mean-squared-errors of
+these estimators to their corresponding Cram\'{e}r-Rao bound as a function of
+the signal-to-noise ratio and the full-width at half-maximum of faint stars.
+  We discuss two general circumstances in centroiding of faint stars: (i) when
+we have a good estimate of the PSF, (ii) when we do not know the PSF. In the
+case that we know the PSF, we show that a fast polynomial centroiding after
+smoothing the image by the PSF can be as efficient as the maximum-likelihood
+estimator at saturating the bound. In the case that we do not know the PSF, we
+demonstrate that although polynomial centroiding is not as optimal as PSF
+profile fitting, it comes very close to saturating the Cram\'{e}r-Rao lower
+bound in a wide range of conditions. We also show that the moment-based method
+of center-of-light never comes close to saturating the bound, and thus it does
+not deliver reliable estimates of centroids.",1610.05873v1
+2019-02-13,Nonlinear saturation and oscillations of collisionless zonal flows,"In homogeneous drift-wave (DW) turbulence, zonal flows (ZFs) can be generated
+via a modulational instability (MI) that either saturates monotonically or
+leads to oscillations of the ZF energy at the nonlinear stage. This dynamics is
+often attributed as the predator--prey oscillations induced by ZF collisional
+damping; however, similar dynamics is also observed in collisionless ZFs, in
+which case a different mechanism must be involved. Here, we propose a
+semi-analytic theory that explains the transition between the oscillations and
+saturation of collisionless ZFs within the quasilinear Hasegawa--Mima model. By
+analyzing phase-space trajectories of DW quanta (driftons) within the
+geometrical-optics (GO) approximation, we argue that the parameter that
+controls this transition is $N\sim\gamma_{{\rm MI}}/\omega_{{\rm DW}}$, where
+$\gamma_{{\rm MI}}$ is the MI growth rate and $\omega_{{\rm DW}}$ is the linear
+DW frequency. We argue that at $N\ll1$, ZFs oscillate due to the presence of
+so-called passing drifton trajectories, and we derive an approximate formula
+for the ZF amplitude as a function of time in this regime. We also show that at
+$N\gtrsim1$, the passing trajectories vanish and ZFs saturate monotonically,
+which can be attributed to phase mixing of higher-order sidebands. A
+modification of $N$ that accounts for effects beyond the GO limit is also
+proposed. These analytic results are tested against both quasilinear and
+fully-nonlinear simulations. They also explain the earlier numerical results by
+Connaughton $\textit{et al}$. [J. Fluid Mech. $\textbf{654}$, 207 (2010)] and
+Gallagher $\textit{et al}$. [Phys. Plasmas $\textbf{19}$, 122115 (2012)] and
+offer a revised perspective on what the control parameter is that determines
+the transition from the oscillations to saturation of collisionless ZFs.",1902.04970v1
+2020-03-12,Multichannel asymmetric transmission through a dimer defect with saturable inter-site nonlinearity,"We consider the asymmetric transmission properties of a Discrete Nonlinear
+Schr{\""o}dinger type dimer with a saturable nonlinear intersite coupling
+between the dimer sites, in addition to a cubic onsite nonlinearity and
+asymmetric linear onsite potentials. In contrast to previously studied cases
+with pure onsite nonlinearities, the transmission coefficient for stationary
+transmission is shown to be a multivalued function of the transmitted
+intensity, in regimes of low saturability and small or moderate transmitted
+intensity. The corresponding backward transfer map is analyzed analytically and
+numerically, and shown to have either one or three distinct solutions for
+saturable coupling, and zero or two solutions for the purely cubic nonlinear
+coupling. As saturation strength is increased, the multi-solution regimes
+disappear through bifurcations and the single-valued regime of the onsite model
+is recovered. The existence of multiple solution branches yields novel
+mechanisms for asymmetric left/right stationary transmission: in addition to
+shifts of the positions of transmission peaks, peaks for transmission in one
+direction may correspond to nonexistence of stationary solutions propagating in
+the opposite direction, at the corresponding branch and transmitted intensity.
+Moreover, one of these transmission channels behaves as a nearly perfect mirror
+for incoming signals. The linear stability of the stationary solutions is
+analyzed, and instabilities are typically observed, and illustrated by direct
+numerical simulations, in regimes with large transmission coefficient.
+Intersite nonlinearities are found to prevent the formation of a localized
+dimer mode in the instability-induced dynamics. Finally, the partial reflection
+and transmission of a Gaussian excitation is studied, and the asymmetric
+transmission properties are compared to previously studied onsite models.",2003.05963v2
+2020-04-16,Direct Astrophysical Tests of Chiral Effective Field Theory at Supranuclear Densities,"Recent observations of neutron stars with gravitational waves and X-ray
+timing provide unprecedented access to the equation of state (EoS) of cold
+dense matter at densities difficult to realize in terrestrial experiments. At
+the same time, predictions for the EoS with reliable uncertainty estimates from
+chiral effective field theory ($\chi$EFT) bound our theoretical ignorance. In
+this work, we analyze astrophysical data using a nonparametric representation
+of the neutron-star EoS conditioned on $\chi$EFT to directly constrain the
+underlying physical properties of the compact objects. We discuss how the data
+alone constrain the EoS at high densities when we condition on $\chi$EFT at low
+densities. We also demonstrate how to exploit astrophysical data to directly
+test the predictions of $\chi$EFT for the EoS up to twice nuclear saturation
+density, and estimate the density at which these predictions might break down.
+We find that the existence of massive pulsars, gravitational waves from
+GW170817, and NICER observations of PSR J0030+0451 favor $\chi$EFT predictions
+for the EoS up to nuclear saturation density over a more agnostic analysis by
+as much as a factor of 7 for the quantum Monte Carlo (QMC) calculations used in
+this work. While $\chi$EFT predictions using QMC are fully consistent with
+gravitational-wave data up to twice nuclear saturation density, NICER
+observations suggest that the EoS stiffens relative to these predictions at
+nuclear saturation density. Additionally, we marginalize over the uncertainty
+in the density at which $\chi$EFT begins to break down, constraining the radius
+of a $1.4\,M_\odot$ neutron star to $R_{1.4}=11.40^{+1.38}_{-1.04}$
+($12.54^{+0.71}_{-0.63}$) km and the pressure at twice nuclear saturation
+density to $p(2n_\mathrm{sat})=14.2^{+18.1}_{-8.4}$ ($28.7^{+15.3}_{-15.0}$)
+MeV/fm$^3$ with massive pulsar and gravitational-wave (and NICER) data.",2004.07744v3
+2021-03-09,Saturating Receiver and Receptor Competition in Synaptic DMC: Deterministic and Statistical Signal Models,"Synaptic communication is based on a biological Molecular Communication (MC)
+system which may serve as a blueprint for the design of synthetic MC systems.
+However, the physical modeling of synaptic MC is complicated by the possible
+saturation of the molecular receiver caused by the competition of
+neurotransmitters (NTs) for postsynaptic receptors. Receiver saturation renders
+the system behavior nonlinear in the number of released NTs and is commonly
+neglected in existing analytical models. Furthermore, due to the ligands'
+competition for receptors (and vice versa), the individual binding events at
+the molecular receiver are in general statistically dependent and the binomial
+model for the statistics of the received signal does not apply. In this work,
+we propose a novel deterministic model for receptor saturation in terms of a
+state-space description based on an eigenfunction expansion of Fick's diffusion
+equation. The presented solution is numerically stable and computationally
+efficient. Employing the proposed deterministic model, we show that saturation
+at the molecular receiver reduces the peak-value of the expected received
+signal and accelerates the clearance of NTs as compared to the case when
+receptor occupancy is neglected. We further derive a statistical model for the
+received signal in terms of the hypergeometric distribution which accounts for
+the competition of NTs for receptors and the competition of receptors for NTs.
+The proposed statistical model reveals how the signal statistics are shaped by
+the number of released NTs, the number of receptors, and the binding kinetics
+of the receptors, respectively, in the presence of competition. We show that
+the impact of these parameters on the signal variance depends on the relative
+numbers of NTs and receptors. The accuracy of the proposed deterministic and
+statistical models is verified by particle-based computer simulations.",2103.05341v2
+2021-04-09,Parton rescattering and gluon saturation in dijet production at EIC,"Large angle gluon radiations induced by multiple parton scatterings
+contribute to dijet production in deeply inelastic scattering off a large
+nucleus at the Electron-Ion Collider. Within the generalized high-twist
+approach to multiple parton scattering, such contributions at the leading order
+in perturbative QCD and large Bjorken momentum fraction $x_B$ can be expressed
+as a convolution of the multiple parton scattering amplitudes and the
+transverse momentum dependent (TMD) two-parton correlation matrix elements. We
+study this medium-induced dijet spectrum and its azimuthal angle correlation
+under the approximation of small longitudinal momentum transfer in the
+secondary scattering and the factorization of two-parton correlation matrix
+elements as a product of quark and gluon TMD parton distribution function
+(PDF). Using a simple model for gluon saturation based on the parametrized
+gluon TMD PDF, we can calculate the $x_B$ and $Q^2$ dependence of the
+saturation scale and parton transport coefficient $\hat q$. Contributions to
+dijet cross section from double scattering are power-suppressed and only become
+sizable for mini-jets at small transverse momentum. We find that the total
+dijet correlation for these mini-jets, which also includes the contribution
+from single scattering, is sensitive to the transverse momentum broadening in
+the quark TMD PDF at large $x$ and saturation in the gluon TMD PDF at small $x$
+inside the nucleus. The correlation from double scattering is also found to
+increase with the dijet rapidity gap and have a quadratic nuclear-size
+dependence because of the Landau-Pomeranchuk-Migdal (LPM) interference in gluon
+emission induced by multiple scattering. Experimental measurements of such
+unique features in the dijet correlation can shed light on the LPM interference
+in strong interaction and gluon saturation in large nuclei.",2104.04520v4
+2021-09-15,Continuous-wave stability and multi-pulse structures in a universal Complex Ginzburg-Landau model for passively mode-locked lasers with saturable absorber,"The dynamics and stability of continuous-wave and multi-pulse structures are
+studied theoretically, for a generalized model of passively mode-locked fiber
+laser with an arbitrary nonlinearity. The model is characterized by a complex
+Ginzburg-Landau equation with saturable nonlinearity of a general form
+($I^m/(1+\Gamma I)^n$), where $I$ is the field intensity, $m$ and $n$ are two
+positive real numbers and $\Gamma$ is the optical field saturation power. The
+analysis of fixed-point solutions of the governing equations, reveals an
+interesting loci of singular points in the amplitude-frequency plane consisting
+of zero, one or two fixed points depending upon the values of $m$ and $n$. The
+stability of continuous waves is analyzed within the framework of the
+modulational-instability theory, results demonstrate a bifurcation in the
+continuous-wave amplitude growth rate and propagation constant characteristic
+of multi-periodic wave structures. In the full nonlinear regime these
+multi-periodic wave structures turn out to be multi-pulse trains, unveiled via
+numerical simulations of the model nonlinear equation the rich variety of which
+is highlighted by considering different combinations of values for the pair
+($m$,$n$). Results are consistent with previous analyses of the dynamics of
+multi-pulse structures in several contexts of passively mode-locked lasers with
+saturable absorber, as well as with predictions about the existence of
+multi-pulse structures and bound-state solitons in optical fibers with strong
+optical nonlinearity such as cubic-quintic and saturable nonlinearities.",2109.07179v1
+2021-12-09,Network mechanisms of working memory: the role of neuronal nonlinearities,"The oculomotor delayed-response (ODR) task is a common experimental paradigm
+of working memory (WM) study, in which a monkey must fixate its gaze on the
+center of a screen and, following a brief cue that flashes on the screen, keep
+fixating for several more seconds before shifting its gaze to the location
+where the cue flashed. Consequently, in the delay period between the cue and
+the response the monkey must maintain a memory of cue location.
+Electrophysiological recordings from the prefrontal area of the cortex (PFC)
+revealed neurons that display selective persistent activity: their firing rate
+change induced by the cue persists through delay period, but only in response
+to a confined range of cue locations. This suggests that the representation of
+the cue is maintained in the network by a change in network activity profile.
+In this work, we study a network of rate-model neurons that is capable of
+preserving information about a past input, owing to structured connectivity and
+nonlinearities in the neuronal transfer function (TFs). Particularly, we focus
+on the acceleration of the TF close to firing threshold and the concavity
+around TF saturation. Any memory mechanism which exploits TF saturation means
+that some neurons must fire close to their saturation rates; with our model,
+however, we show that a certain relation between the excitatory and inhibitory
+neurons' TFs can cause an effective saturation in the network without forcing
+the neurons into the saturating parts of their TFs. In addition, this mechanism
+enables the erasure of memory at the end of the delay by a global excitatory
+signal. Finally, we demonstrate the mechanism in a model network of spiking
+neurons which describes with more detail the oscillatory dynamics in the state
+transition due to the interaction of membrane and synaptic time constants which
+is neglected in the rate model.",2112.05091v1
+2022-11-18,Numerical simulation of two-phase flow in gas diffusion layer and gas channel of proton exchange membrane fuel cells,"Liquid water within the cathode Gas Diffusion Layer (GDL) and Gas Channel
+(GC) of Proton Exchange Membrane Fuel Cells (PEMFCs) is strongly coupled to gas
+transport properties, thereby affecting the electrochemical conversion rates.
+In this study, the GDL and GC regions are utilized as the simulation domain,
+which differs from previous studies that only focused on any one of them. A
+volume-of-fluid method is adopted to numerically investigate the two-phase flow
+(gas and liquid) behavior, e.g., water transport pattern evolution, water
+coverage ratio as well as local and total water saturation. To obtain GDL
+geometries, an in-house geometry-based method is developed for GDL
+reconstruction. Furthermore, to study the effect of GDL carbon fiber diameter,
+the same procedure is used to reconstruct three GDL structures by varying the
+carbon fiber diameter but keeping the porosity and geometric dimensions
+constant. The wall wettability is introduced with static contact angles at
+carbon fiber surfaces and channel walls. The results show that the GDL fiber
+microstructure has a significant impact on the two-phase flow patterns in the
+cathode field. Different stages of two-phase flow pattern evolution in both
+cathode domains are observed. Due to the difference in wettability, the water
+coverage of the GDL/GC interface is smaller than that of the channel side and
+top walls. It is also found that the water saturation inside the GDLs
+stabilizes after the water breakthrough, while local water saturation at the
+interface keeps irregular oscillations. Last but not the least, a water
+saturation balance requirement between the GDL and GC is observed. In terms of
+varying fiber diameter, a larger fiber diameter would result in less water
+saturation in the GDL but more water in the GC, in addition to faster water
+movement throughout the total domain.",2211.10084v1
+2022-12-15,Microscopic theory of nonlinear phase space filling in polaritonic lattices,"We develop a full microscopic theory for a nonlinear phase space filling
+(NPSF) in strongly coupled two-dimensional polaritonic lattices. Ubiquitous in
+polaritonic experiments, the theoretical description of NPSF, remains limited
+to perturbative treatment and homogeneous samples. In this study, we go beyond
+the existing theoretical description and discover the broad scope of regimes
+where NPSF crucially modifies the optical response. Studying the quantum
+effects of non-bosonicity, cooperative light-matter coupling, and Coulomb
+blockade, we reveal several regimes for observing the nonlinear Rabi splitting
+quench due to the phase space filling. Unlike prior studies, we derive
+nonlinear Rabi frequency scaling all the way to the saturation limit and show
+that the presence of a lattice potential leads to qualitatively distinct
+nonlinearity. We concentrate on three regimes of NPSF: 1) planar; 2) fractured;
+and 3) ultralocalized. In planar saturation, the Rabi frequency decreases
+exponentially as a function of exciton density. For the fractured case, where
+excitons form a lattice with sites exceeding the exciton size, we discover fast
+NPSF at low occupation in the lattice. This is followed by slower NPSF as the
+medium becomes fully saturated. This behavior is particularly pronounced in the
+presence of Coulomb (or Rydberg) blockade, where regions of fast and slow NPSF
+depend on the strength of repulsion. For the ultralocalized NPSF, we observe
+the square-root saturation typical to the collection of two-level systems. Our
+findings can help describing recent observations of strong nonlinearity in
+heterobilayers of transition metal dichalcogenides where Moir{\'e} lattices
+emerge naturally [Nature \textbf{591}, 61 (2021)]. The theory also opens the
+prospects for engineering strongly nonlinear responses of polaritonic lattices
+with patterned samples, driving polaritonics into the quantum regime.",2212.07968v2
+2023-03-19,Noninvasive in vivo photoacoustic measurement of internal jugular venous oxygenation in humans,"In many clinical conditions, such as head trauma, stroke, and low cardiac
+output states, the brain is at risk for hypoxic-ischemic injury. The metabolic
+rate and oxygen consumption of the brain are reflected in internal jugular
+venous oxygen saturation (sijvO2). The current gold standard for monitoring
+brain oxygenation is invasive; it requires jugular vein catheterization under
+fluoroscopic guidance and therefore is rarely used. Photoacoustic (PA)
+measurement, on the other hand, can estimate the oxygen consumption of the
+brain non-invasively in real time. Such a convenient method can potentially aid
+earlier detection and prevention of impending hypoxic brain injury. A
+dual-wavelength photoacoustic tomography (PAT) and ultrasound imaging (US)
+system was used to image the internal jugular vein (IJV) and estimate the
+sijvO2 in seven healthy volunteers. The system captured simultaneous
+co-registered PAT and US images at a rate of five frames per second. For each
+volunteer, the internal jugular vein was identified under ultrasound guidance,
+then, additional PA images from two optical wavelengths were collected and used
+to estimate the oxygen saturation of the internal jugular vein. For each
+volunteer, the oxygen saturation was calculated from transverse and
+longitudinal views of the internal jugular vein. The average sijvO2 was 72 +/-
+7 %. The preliminary results are encouraging and agree with those reported in
+the literature. Photoacoustic images were successfully used to calculate the
+blood hemoglobin oxygen saturation in the internal jugular vein. These results
+raise confidence that this emerging technology can be used clinically for
+accurate, noninvasive estimation of sijvO2. In addition, the fast
+co-registration with US images makes the technique suitable for studying the
+temporal variations of oxygen saturation in response to physiologic challenges
+in clinical settings.",2303.10775v1
+2024-02-06,Saturation of fishbone instability through zonal flows driven by energetic particle transport in tokamak plasmas,"Gyrokinetic and kinetic-MHD simulations are performed for the fishbone
+instability in the DIII-D discharge #178631, chosen for validation of
+first-principles simulations to predict the energetic particle (EP) transport
+in an ITER prefusion baseline scenario. Fishbone modes are found to generate
+zonal flows, which dominate the fishbone saturation. The underlying mechanisms
+of the two-way fishbone-zonal flows nonlinear interplay are discussed in
+details. Numerical and analytical analyses identify the fishbone-induced EP
+redistribution as the dominant generation mechanism for zonal flows. The zonal
+flows modify the nonlinear dynamics of phase space zonal structures, which
+reduces the amount of EPs able to resonate with the mode, leading to an early
+fishbone saturation. Simulation results including zonal flows agree
+quantitatively with DIII-D experimental measurements of the fishbone saturation
+amplitude and EP transport, supporting this novel saturation mechanism by
+self-generated zonal flows. Moreover, the wave-particle mode-locking mechanism
+is shown to determine quantitatively the fishbone frequency down-chirping, as
+evident in GTC simulation results in agreement with predictions from analytical
+theory. Finally, the fishbone-induced zonal flows are possibly responsible for
+the formation of an ion-ITB in the DIII-D discharge. Based on the low EP
+transport and the large zonal flow shearing rates associated with the fishbone
+instability in gyrokinetic simulations of the ITER scenario, it is conjectured
+that high performance scenarios could be designed in ITER burning plasmas
+through fishbone-induced ITBs.",2402.03797v1
+2006-05-18,Small-scale magnetic buoyancy and magnetic pumping effects in a turbulent convection,"We determine the nonlinear drift velocities of the mean magnetic field and
+nonlinear turbulent magnetic diffusion in a turbulent convection. We show that
+the nonlinear drift velocities are caused by the three kinds of the
+inhomogeneities, i.e., inhomogeneous turbulence; the nonuniform fluid density
+and the nonuniform turbulent heat flux. The inhomogeneous turbulence results in
+the well-known turbulent diamagnetic and paramagnetic velocities. The nonlinear
+drift velocities of the mean magnetic field cause the small-scale magnetic
+buoyancy and magnetic pumping effects in the turbulent convection. These
+phenomena are different from the large-scale magnetic buoyancy and magnetic
+pumping effects which are due to the effect of the mean magnetic field on the
+large-scale density stratified fluid flow. The small-scale magnetic buoyancy
+and magnetic pumping can be stronger than these large-scale effects when the
+mean magnetic field is smaller than the equipartition field. We discuss the
+small-scale magnetic buoyancy and magnetic pumping effects in the context of
+the solar and stellar turbulent convection. We demonstrate also that the
+nonlinear turbulent magnetic diffusion in the turbulent convection is
+anisotropic even for a weak mean magnetic field. In particular, it is enhanced
+in the radial direction. The magnetic fluctuations due to the small-scale
+dynamo increase the turbulent magnetic diffusion of the toroidal component of
+the mean magnetic field, while they do not affect the turbulent magnetic
+diffusion of the poloidal field.",0605444v1
+2019-09-09,Photospheric magnetic structure of coronal holes,"In this study, we investigate in detail the photospheric magnetic structure
+of 98 coronal holes using line-of-sight magnetograms of SDO/HMI, and for a
+subset of 42 coronal holes using HINODE/SOT G-band filtergrams. We divided the
+magnetic field maps into magnetic elements and quiet coronal hole regions by
+applying a threshold at $\pm 25$ G. We find that the number of magnetic bright
+points in magnetic elements is well correlated with the area of the magnetic
+elements (cc=$0.83\pm 0.01$). Further, the magnetic flux of the individual
+magnetic elements inside coronal holes is related to their area by a power law
+with an exponent of $1.261\pm 0.004$ (cc=$0.984\pm 0.001$). Relating the
+magnetic elements to the overall structure of coronal holes, we find that on
+average ($69\pm 8$) % of the overall unbalanced magnetic flux of the coronal
+holes arises from long-lived magnetic elements with lifetimes > 40 hours. About
+($22\pm 4$) % of the unbalanced magnetic flux arises from a very weak
+background magnetic field in the quiet coronal hole regions with a mean
+magnetic field density of about 0.2 to 1.2 G. This background magnetic field is
+correlated to the flux of the magnetic elements with lifetimes of > 40 h
+(cc=$0.88\pm 0.02$). The remaining flux arises from magnetic elements with
+lifetimes < 40 hours. By relating the properties of the magnetic elements to
+the overall properties of the coronal holes, we find that the unbalanced
+magnetic flux of the coronal holes is completely determined by the total area
+that the long-lived magnetic elements cover (cc=$0.994\pm 0.001$).",1909.03806v1
+2006-08-14,Thermal relaxation of magnetic clusters in amorphous Hf_{57}Fe_{43} alloy,"The magnetization processes in binary magnetic/nonmagnetic amorphous alloy
+Hf_{57}Fe_{43} are investigated by the detailed measurements of magnetic
+hysteresis loops, temperature dependence of magnetization, relaxation of
+magnetization and magnetic ac susceptibility, including a nonlinear term.
+Blocking of magnetic moments at lower temperatures is accompanied with the slow
+relaxation of magnetization and magnetic hysteresis loops. All of the observed
+properties are explained with the superparamagnetic behaviour of the single
+domain magnetic clusters inside the nonmagnetic host, their blocking by the
+anisotropy barriers and thermal fluctuation over the barriers accompanied by
+relaxation of magnetization. From magnetic viscosity analysis based on thermal
+relaxation over the anisotropy barriers it is found out that magnetic clusters
+occupy the characteristic volume from 25 up to 200 nm3 . The validity of the
+superparamagnetic model of Hf_{57}Fe_{43} is based on the concentration of iron
+in the Hf_{100-x}Fe_{43} system that is just below the threshold for the long
+range magnetic ordering. This work throws more light on magnetic behaviour of
+other amorphous alloys, too.",0608307v3
+2007-06-13,Nonlinear turbulent magnetic diffusion and effective drift velocity of large-scale magnetic field in a two-dimensional magnetohydrodynamic turbulence,"We study a nonlinear quenching of turbulent magnetic diffusion and effective
+drift velocity of large-scale magnetic field in a developed two-dimensional MHD
+turbulence at large magnetic Reynolds numbers. We show that transport of the
+mean-square magnetic potential strongly changes quenching of turbulent magnetic
+diffusion. In particularly, the catastrophic quenching of turbulent magnetic
+diffusion does not occur for the large-scale magnetic fields $B \gg B_{\rm eq}
+/ \sqrt{\rm Rm}$ when a divergence of the flux of the mean-square magnetic
+potential is not zero, where $B_{\rm eq}$ is the equipartition mean magnetic
+field determined by the turbulent kinetic energy and Rm is the magnetic
+Reynolds number. In this case the quenching of turbulent magnetic diffusion is
+independent of magnetic Reynolds number. The situation is similar to
+three-dimensional MHD turbulence at large magnetic Reynolds numbers whereby the
+catastrophic quenching of the alpha effect does not occur when a divergence of
+the flux of the small-scale magnetic helicity is not zero.",0706.1846v1
+2007-10-26,Magnetic fluctuations and formation of large-scale inhomogeneous magnetic structures in a turbulent convection,"Magnetic fluctuations generated by a tangling of the mean magnetic field by
+velocity fluctuations are studied in a developed turbulent convection with
+large magnetic Reynolds numbers. We show that the energy of magnetic
+fluctuations depends on magnetic Reynolds number only when the mean magnetic
+field is smaller than $B_{eq} / 4 Rm^{1/4}$, where $B_{eq}$ is the
+equipartition mean magnetic field determined by the turbulent kinetic energy
+and Rm is magnetic Reynolds number. Generation of magnetic fluctuations in a
+turbulent convection with a nonzero mean magnetic field results in a decrease
+of the total turbulent pressure and may cause formation of the large-scale
+inhomogeneous magnetic structures even in an originally uniform mean magnetic
+field. This effect is caused by a negative contribution of the turbulent
+convection to the effective mean Lorentz force. The inhomogeneous large-scale
+magnetic fields are formed due to the excitation of the large-scale
+instability. The energy for this instability is supplied by the small-scale
+turbulent convection. The discussed effects might be useful for understanding
+the origin of the solar nonuniform magnetic fields, e.g., sunspots.",0710.5052v1
+2013-11-18,"Fabrication, properties, and applications of flexible magnetic films","Flexible magnetic devices, i.e., magnetic devices fabricated on flexible
+substrates, are very attractive in application of detecting magnetic field in
+arbitrary surface, non-contact actuators, and microwave devices due to the
+stretchable, biocompatible, light-weight, portable, and low cost properties.
+Flexible magnetic films are essential for the realization of various
+functionalities of flexible magnetic devices. To give a comprehensive
+understanding for flexible magnetic films and related devices, we have reviewed
+recent advances in the studies of flexible magnetic films including fabrication
+methods, magnetic and transport properties of flexible magnetic films, and
+their applications in magnetic sensors, actuators, and microwave devices. Three
+typical methods were introduced to prepare the flexible magnetic films.
+Stretching or bending the flexible magnetic films offers a good way to apply
+mechanical strain on magnetic films, so that magnetic anisotropy, exchanged
+bias, coercivity, and magnetoresistance can be effectively manipulated.
+Finally, a series of examples were shown to demonstrate the great potential of
+flexible magnetic films for future applications.",1311.4318v1
+2021-10-31,Shape Programmable Magnetic Pixel Soft Robot,"Magnetic response soft robot realizes programmable shape regulation with the
+help of magnetic field and produces various actions. The shape control of
+magnetic soft robot is based on the magnetic anisotropy caused by the orderly
+distribution of magnetic particles in the elastic matrix. In the previous
+technologies, magnetic programming is coupled with the manufacturing process,
+and the orientation of magnetic particles cannot be modified, which brings
+restrictions to the design and use of magnetic soft robot. This paper presents
+a magnetic pixel robot with shape programmable function. By encapsulating
+NdFeB/gallium composites into silicone shell, a thermo-magnetic response
+functional film with lattice structure are fabricated. Basing on
+thermal-assisted magnetization technique, we realized the discrete
+magnetization region distribution on the film. Therefore, we proposed a
+magnetic coding technique to realize the mathematical response action design of
+software robot. Using these methods, we prepared several magnetic soft robots
+based on origami structure. The experiments show that the behavior mode of
+robot can be flexibly and repeatedly regulated by magnetic encoding technique.
+This work provides a basis for the programmed shape regulation and motion
+design of soft robot.",2111.00422v2
+2022-02-07,Magnetism of QCD matter and pion mass from tensor-type spin polarization and anomalous magnetic moment of quarks,"We investigate the magnetism of QCD matter and pion mass under magnetic field
+considering the contribution from the tensor-type spin polarization and the
+anomalous magnetic moment (AMM) of quarks. It is found that the tensor-type
+spin polarization (TSP) induces the magnetic catalysis of chiral condensate and
+diamagnetism (negative magnetic susceptibility) of quark matter at low
+temperature, both neutral and charged pion masses increase quickly with
+magnetic field in the case of TSP. The anomalous magnetic moment (AMM) of
+quarks induces magnetic inhibition and a magnetic dependent AMM causes inverse
+magnetic catalysis at finite temperature, and the neutral pion mass decreases
+with magnetic field while the charged pion mass shows nonmonotonic behavior
+with the magnetic field, which is qualitatively in agreement with lattice
+result. However, the magnetic susceptibility is positive at low temperature
+with AMM. In the current framework, our results show the irreconcilable
+contradiction between the diamagnetism and inverse magnetic catalysis.",2202.03226v1
+2022-10-06,Current-induced perpendicular effective magnetic field in magnetic heterostructures,"Generation of perpendicular effective magnetic field or perpendicular spins
+({\sigma}z) is central for the development of energy-efficient, scalable, and
+external-magnetic-field-free spintronic memory and computing technologies.
+Here, we report the first identification and the profound impacts of a
+significant effective perpendicular magnetic field that can arise from
+asymmetric current spreading within magnetic microstrips and Hall bars. This
+effective perpendicular magnetic field can exhibit all the three
+characteristics that have been widely assumed in the literature to ""signify""
+the presence of a flow of {\sigma}z, i.e., external-magnetic-field-free current
+switching of uniform perpendicular magnetization, a sin2{\phi}-dependent
+contribution in spin-torque ferromagnetic resonance signal of in-plane
+magnetization ({\phi} is the angle of the external magnetic field with respect
+to the current, and a {\phi}-independent but field-dependent contribution in
+the second harmonic Hall voltage of in-plane magnetization. This finding
+suggests that it is critical to include current spreading effects in the
+analyses of various spin polarizations and spin-orbit torques in magnetic
+heterostructure. Technologically, our results provide perpendicular effective
+magnetic field induced by asymmetric current spreading as a novel, universally
+accessible mechanism for efficient, scalable, and external-magnetic-field-free
+magnetization switching in memory and computing technologies.",2210.02916v1
+2010-03-09,MAGNETIC ANOMALY IN SUPERCONDUCTING FeSe,"Synthesis, electrical and magnetic characterization of superconducting
+FeSe0.85 compound is reported. An anomaly in the magnetization against
+temperature around 90K is observed. Magnetic characterization of a commercial
+compound with nominal FeSe stoichiometry is also presented. The overall
+magnetic behaviors as well as the magnetic anomaly in both compounds are
+discussed in terms of magnetic impurities and secondary phases. Keyword: A.
+Superconductors",1003.1966v1
+2011-05-19,Ultra-fast spin avalanches in crystals of molecular magnets in terms of magnetic detonation,"Recent experiments (Decelle et al., Phys. Rev. Lett. 102, 027203 (2009))
+discovered an ultra-fast regime of spin avalanches in crystals of magnetic
+magnets, which was three orders of magnitude faster than the traditionally
+studied magnetic deflagration. The new regime has been hypothetically
+identified as magnetic detonation. Here we demonstrate the possibility of
+magnetic detonation in the crystals, as a front consisting of a leading shock
+and a zone of Zeeman energy release. We study the dependence of the magnetic
+detonation parameters on the applied magnetic field. We find that the magnetic
+detonation speed only slightly exceeds the sound speed in agreement with the
+experimental observations.",1105.3962v1
+2013-07-18,Interaction effect detected by compared of the irreversible and remanent initial magnetization curves in Ni-Cu-Zn ferrites,"A new technique for estimation of magnetic interaction effects of initial
+magnetization curves has been proposed. It deals with remanence, and initial
+irreversible magnetization, curves. The method is applied for single-phase
+polycrystalline Ni0.85-xCu0.15ZnxFe2O4, (x = 0, 0.2, 0.4 and 0.6), which were
+synthesized by a standard ceramic technology. A study of the initial reversible
+and irreversible magnetization processes in ferrite materials was carried out.
+The field dependence of the irreversible, and reversible, magnetizations was
+determined by magnetic losses of minor hysteresis loops obtained from different
+points of an initial magnetization curve. The influence of Zn-substitutions in
+Ni-Cu ferrites over irreversible magnetization processes and interactions in
+magnetic systems has been analyzed.",1307.4881v1
+2013-10-15,Plasticity-Induced Magnetization in Amorphous Magnetic Solids,"Amorphous magnetic solids, like metallic glasses, exhibit a novel effect: the
+growth of magnetic order as a function of mechanical strain under athermal
+conditions in the presence of a magnetic field. The magnetic moment increases
+in steps whenever there is a plastic event. Thus plasticity induces the
+magnetic ordering, acting as the effective noise driving the system towards
+equilibrium. We present results of atomistic simulations of this effect in a
+model of a magnetic amorphous solid subjected to pure shear and a magnetic
+field. To elucidate the dependence on external strain and magnetic field we
+offer a mean-field theory that provides an adequate qualitative understanding
+of the observed phenomenon.",1310.3979v1
+2017-09-11,Magnetic order and phase transition in the iron oxysulfide La2O2Fe2OS2,"The Mott-insulating iron oxychalcogenides exhibit complex magnetic behaviour
+and we report here a neutron diffraction investigation into the magnetic
+ordering in La2O2Fe2OS2. This quaternary oxysulfide adopts the
+anti-Sr2MnO2Sb2-type structure and orders antiferromagnetically below TN = 105
+K. We consider both its long-range magnetic structure and its magnetic
+microstructure, and the onset of magnetic order. It adopts the multi-k vector
+""2k"" magnetic structure (k = (0.5 0 0.5) and k = (0 0.5 0.5) and has
+similarities with related iron oxychalcogenides, illustrating the robust nature
+of the ""2k"" magnetic structure.",1709.03323v1
+2022-12-07,Quark condensate and magnetic moment in a strong magnetic field,"This paper studies the quark condensate, magnetic moment, magnetic
+polarization, and magnetic susceptibility in a strong external magnetic field
+by employing the Dyson-Schwinger equations (DSE). The results show that these
+physical quantities as functions of the magnetic field. We note that the
+quark's spin polarizations are approximately proportional to the magnetic field
+magnitude. For comparison, we investigate the magnetic moments and
+susceptibility of the nucleon in the constituent quark model framework and
+demonstrate that both these quantities increase as the magnetic field rises.",2212.03508v2
+2023-12-26,Magnetic vortex control with current-induced axial magnetization in centrosymmetric Weyl materials,"We consider magnetic Weyl metals as a platform to achieve current control of
+magnetization textures with transport currents, utilizing their underlying band
+geometry. We show that the transport current in a Weyl semimetal produces an
+axial magnetization due to orbital magnetic moments of the Weyl electrons. The
+associated axial magnetization can generate a torque acting on the localized
+magnetic moments. For the case of a magnetic vortex in a nanodisk of Weyl
+materials, this current-induced torque can be used to reverse its circulation
+and polarity. We discuss the axial magnetization torques in Weyl metals on
+general symmetry grounds, and compare their strength to current-induced torques
+in more conventional materials.",2312.16122v1
+2004-09-08,Magnetic and electronic phase transformations in (Sm0.65Sr0.35)MnO3 induced by temperature and magnetic field,"Temperature (4.2-260 K) and magnetic field (0-50 kOe) dependencies of the dc
+electrical resistance, dc magnetization, and ac magnetic susceptibility of
+(Sm0.65Sr0.35)MnO3 prepared from high purity components have been studied.",0409213v1
+2008-02-20,Anomalous Magnetic Properties of Sr2YRuO6,"Anomalous magnetic properties of the double perovskite ruthenates compound
+Sr2YRuO6 are reported here. Magnetization measurements as a function of
+temperature in low magnetic fields show clear evidence for two components of
+magnetic order (TM1 ~ 32K and TM2 ~ 27K) aligned opposite to each other with
+respect to the magnetic field direction even though only Ru5+moments can order
+magnetically in this compound. The second component of the magnetic order at
+TM2 ~ 27K results only in a magnetization reversal, and not in the negative
+magnetization when the magnetization is measured in the field cooled (FC) mode.
+Isothermal magnetization (M-H) measurements show hysteresis with maximum
+coercivity (Hc) and remnant magnetization (Mr) at T ~ 27 K, corroborating the
+presence of the two oppositely aligned magnetic moments, each with a
+ferromagnetic component. The two components of magnetic ordering are further
+confirmed by the double peak structure in the heat capacity measurements. These
+anomalous properties have significance to some of the earlier results obtained
+for the Cu-substituted superconducting Sr2YRu1-xCuxO6 compounds.",0802.2953v2
+2014-09-05,"Analysis of the magnetic field, force, and torque for two-dimensional Halbach cylinders","The Halbach cylinder is a construction of permanent magnets used in
+applications such as nuclear magnetic resonance apparatus, accelerator magnets
+and magnetic cooling devices. In this paper the analytical expression for the
+magnetic vector potential, magnetic flux density and magnetic field for a two
+dimensional Halbach cylinder are derived. The remanent flux density of a
+Halbach magnet is characterized by the integer $p$. For a number of
+applications the force and torque between two concentric Halbach cylinders are
+important. These quantities are calculated and the force is shown to be zero
+except for the case where $p$ for the inner magnet is one minus $p$ for the
+outer magnet. Also the force is shown never to be balancing. The torque is
+shown to be zero unless the inner magnet $p$ is equal to minus the outer magnet
+$p$. Thus there can never be a force and a torque in the same system.",1409.1712v1
+2018-12-18,(Self-)Magnetized Bose-Einstein Condensate stars,"We study magnetic field effects on the Equations of State (EoS) and the
+structure of Bose-Einstein Condensate (BEC) stars, i.e. a compact object
+composed by a gas of interacting spin one bosons formed up by the pairing of
+two neutrons. To include the magnetic field in the thermodynamic description,
+we suppose that particle-magnetic field and particle-particle interactions are
+independent. We consider two configurations for the magnetic field: one where
+it constant and externally fixed, and another where it is produced by the
+bosons by self-magnetization. Since the magnetic field produces the splitting
+of pressures in the directions along and perpendicular to the magnetic axis,
+stable configurations of self-magnetized and magnetized BEC stars are studied
+using the recently found $\gamma$-structure equations that describe axially
+symmetric objects. The magnetized BEC stars are, in general spheroidal, less
+massive and smaller than the non-magnetic ones, being these effects more
+relevant at low densities. For the self-magnetized BEC stars their inner
+profiles of magnetic field can be computed as a function of the equatorial
+radii. The values obtained for the core and surface magnetic fields are in
+agreement with those typical of compact objects.",1812.07657v1
+2019-12-03,Internally-Balanced Magnetic Mechanisms Using Magnetic Spring for Producing Large Amplified Clamping Force,"To detach a permanent magnet with a controlled force much smaller than its
+original attractive force, the Internally-Balanced Magnetic Unit (IB Magnet)
+was invented and has been applied to magnetic devices such as wall-climbing
+robots, ceil-dangling drones, and modular swarm robots. In contrast to its
+drastic reduction rate on the control force, the IB Magnet has two major
+problems on its nonlinear spring which cancels out the internal force on the
+magnet: complicated design procedure and trade-off relationship between
+balancing precision and mechanism volume. This paper proposes a principle of a
+new balancing method for the IB Magnet which uses a like-pole pair of magnets
+as a magnetic spring, whose repulsive force ideally equals the attractive force
+of an unlike-pole pair exactly. To verify the proposed principle, the authors
+realized a prototype model of the IB Magnet using magnetic spring and verified
+through experiments its reduction rate is comparable to those of conventional
+IB Magnets. Moreover, the authors discussed and realized a robotic clamp as an
+application example containing proposed IB Magnets as its internal mechanism.",1912.01292v1
+2020-09-14,Voltage-driven Magnetization Switching via Dirac Magnetic Anisotropy and Spin--orbit Torque in Topological-insulator-based Magnetic Heterostructures,"Electric-field control of magnetization dynamics is fundamentally and
+technologically important for future spintronic devices. Here, based on
+electric-field control of both magnetic anisotropy and spin--orbit torque, two
+distinct methods are presented for switching the magnetization in topological
+insulator (TI)/magnetic-TI hybrid systems. The magnetic anisotropy energy in
+magnetic TIs is formulated analytically as a function of the Fermi energy, and
+it is confirmed that the out-of-plane magnetization is always favored for the
+partially occupied surface band. Also proposed is a transistor-like device with
+the functionality of a nonvolatile magnetic memory that uses voltage-driven
+writing and the (quantum) anomalous Hall effect for readout. For the
+magnetization reversal, by using parameters of Cr-doped
+Bi_{1-x}Sb_{x})_{2}Te_{3}, the estimated source-drain current density and gate
+voltage are of the orders of $10^4$--$10^5$~A/cm$^2$ and 0.1~V, respectively,
+below 20~K and the writing requires no external magnetic field. Also discussed
+is the possibility of magnetization switching by the proposed method in
+TI/ferromagnetic-insulator bilayers with the magnetic proximity effect.",2009.06187v1
+2021-07-10,Photoinduced Magnetic Force Microscopy: Enabling Direct and Exclusive Detection of Optical Magnetism,"Modern optical nano-elements pursue ever-smaller sizes and individualized
+functionalities. Those elements that can efficiently manipulate the magnetic
+field of light boast promising future applications with a great challenge: the
+magnetic near field is irretrievable from conventional optical far-field
+characterization. Here we propose photoinduced magnetic force microscopy to
+directly and exclusively sense the magnetic field of light at the nanoscale.
+The proposed instrument exploits a magnetic nanoprobe with exclusive magnetic
+excitation under structured light illumination. The magnetic nanoprobe detects
+the photoinduced magnetic force, which is defined as the dipolar Lorentz force
+exerted on the photoinduced magnetic dipole in the nanoprobe. Since the
+resulting magnetic force is proportional to the incident magnetic field, the
+measured force reveals the magnetic near-field distribution at the nanoscale.
+The proposed instrument represents a fundamental step towards comprehensive
+electric and magnetic near-field detection and/or manipulation in single
+nano-element optical devices.",2107.04739v1
+2022-08-31,Second-order phase transition of silicon from a band insulator to metal induced by strong magnetic fields,"We present the second-order phase transition from a band insulator to metal
+that is induced by a strong magnetic field. The magnetic-field dependences of
+the magnetization and energy band gap of a crystalline silicon immersed in a
+magnetic field are investigated by means of the nonperturbative
+magnetic-field-containing relativistic tight-binding approximation method
+[Phys. Rev. B 97, 195135 (2018)]. It is shown that the energy band gap
+disappears at the critical magnetic field of 2.22x$10^4$ (T). At the critical
+magnetic field, the magnetic-field dependence of the magnetization exhibits a
+kink behavior, which means that this phenomenon is the second-order phase
+transition from a band insulator to metal. It is found that in strong magnetic
+fields above the critical magnetic field, namely in the metallic phase, the
+oscillation of the magnetization appears. It is shown that this magnetic
+oscillation comes from the energy bands in the magnetic Brillouin zone that
+change from the occupied states to unoccupied states or vice vasa.",2208.14690v1
+2023-07-18,Yu-Shiba-Rusinov tips: imaging spins at the atomic scale with full magnetic sensitivity,"Measurements of magnetic properties at the atomic scale require probes
+capable of combining high spatial resolution with spin sensitivity.
+Spin-polarized scanning tunneling microscopy (SP-STM) fulfills these conditions
+by using atomically sharp magnetic tips. The imaging of spin structures results
+from the tunneling magneto-conductance that depends on the imbalance in the
+local density of spin-up and spin-down electrons. Spin-sensitive tips are
+generally formed from bulk materials or by coating non-magnetic tips with a
+thin magnetic layer. However, ferromagnetic materials generate stray magnetic
+fields which can influence the magnetic structure of the probed system, while
+the magnetization of antiferromagnetic materials is difficult to set tip by
+externally applied magnetic fields. Here, we use functionalized
+Yu-Shiba-Rusinov (YSR) tips prepared by attaching magnetic adatoms at the apex
+of a superconducting cluster to image magnetic interactions at the atomic
+scale. We demonstrate that YSR tips are capable of sensing different
+magnetization directions, conferring them full magnetic sensitivity. We
+additionally show that the finite size of the tip superconducting cluster makes
+it robust against relatively strong magnetic fields, making YSR tips capable of
+visualizing magnetic field driven transitions of the spin texture.",2307.09534v1
+2024-03-20,Molecular Dynamics Simulations of Microscopic Structural Transition and Macroscopic Mechanical Properties of Magnetic Gels,"Magnetic gels with embedded micro/nano-sized magnetic particles in
+crosslinked polymer networks can be actuated by external magnetic fields, with
+changes in their internal microscopic structures and macroscopic mechanical
+properties. We investigate the responses of such magnetic gels to an external
+magnetic field, by means of coarse-grained molecular dynamics simulations. We
+find that the dynamics of magnetic particles are determined by the interplay of
+between magnetic dipole-dipole interactions, polymer elasticity and thermal
+fluctuations. The corresponding microscopic structures formed by the magnetic
+particles such as elongated chains can be controlled by the external magnetic
+field. Furthermore, the magnetic gels can exhibit reinforced macroscopic
+mechanical properties, where the elastic modulus increases algebraically with
+the magnetic moments of the particles in the form of
+$\propto(m-m_{\mathrm{c}})^{2}$ when magnetic chains are formed. This
+simulation work can not only serve as a tool for studying the microscopic and
+the macroscopic responses of the magnetic gels, but also facilitate future
+fabrications and practical controls of magnetic composites with desired
+physical properties.",2403.13481v1
+2017-02-07,Characteristics of Low-Latitude Coronal Holes near the Maximum of Solar cycle 24,"We investigate the statistics of 288 low-latitude coronal holes extracted
+from SDO/AIA-193 filtergrams over the time range 2011/01/01 to 2013/12/31. We
+analyse the distribution of characteristic coronal hole properties, such as the
+areas, mean AIA-193 intensities, and mean magnetic field densities, the local
+distribution of the SDO/AIA-193 intensity and the magnetic field within the
+coronal holes, and the distribution of magnetic flux tubes in coronal holes. We
+find that the mean magnetic field density of all coronal holes under study is
+3.0 +- 1.6 G, and the percentage of unbalanced magnetic flux is 49 +- 16 %. The
+mean magnetic field density, the mean unsigned magnetic field density, and the
+percentage of unbalanced magnetic flux of coronal holes depend strongly
+pairwise on each other, with correlation coefficients cc > 0.92. Furthermore,
+we find that the unbalanced magnetic flux of the coronal holes is predominantly
+concentrated in magnetic flux tubes: 38 % (81 %) of the unbalanced magnetic
+flux of coronal holes arises from only 1 % (10 %) of the coronal hole area,
+clustered in magnetic flux tubes with field strengths > 50 G (10 G). The
+average magnetic field density and the unbalanced magnetic flux derived from
+the magnetic flux tubes correlate with the mean magnetic field density and the
+unbalanced magnetic flux of the overall coronal hole (cc > 0.93). These
+findings give evidence that the overall magnetic characteristics of coronal
+holes are governed by the characteristics of the magnetic flux tubes.",1702.02050v1
+2019-12-09,Field Dependence of Magnetic Disorder in Nanoparticles,"The performance characteristics of magnetic nanoparticles towards
+application, e.g. in medicine, imaging, or as sensors, is directly determined
+by their magnetization relaxation and total magnetic moment. In the commonly
+assumed picture, nanoparticles have a constant overall magnetic moment
+originating from the magnetization of the single-domain particle core
+surrounded by a surface region hosting spin disorder. In contrast, this work
+demonstrates the significant increase of the magnetic moment of ferrite
+nanoparticles with applied magnetic field. At low magnetic field, the
+homogeneously magnetized particle core initially coincides in size with the
+structurally coherent grain of 12.8(2) nm diameter, indicating a strong
+coupling between magnetic and structural disorder. Applied magnetic fields
+gradually polarize the uncorrelated, disordered surface spins, resulting in a
+magnetic volume more than 20\% larger than the structurally coherent core. The
+intraparticle magnetic disorder energy increases sharply towards the
+defect-rich surface as established by the field-dependence of the magnetization
+distribution. In consequence, these findings illustrate how the nanoparticle
+magnetization overcomes structural surface disorder. This new concept of
+intraparticle magnetization is deployable to other magnetic nanoparticle
+systems, where the in-depth knowledge of spin disorder and associated magnetic
+anisotropies will be decisive for a rational nanomaterials design.",1912.04081v2
+2021-04-23,Interesting magnetic response of the nuclear fuel material UO2,"Magnetic response of uranium dioxide (UO2) has been investigated through
+temperature and magnetic field dependent dc magnetization measurements. UO2 is
+a paramagnet at room temperature. The magnetic susceptibility, however,
+deviates from Curie-Weiss (CW) like paramagnetic behavior below T = 280 K.
+Further down the temperature UO2 undergoes phase transition to an
+antiferromagnetic state below TN = 30.6 K. The zero field cooled (ZFC) and
+field cooled (FC) magnetizations exhibit some distinct thermomagnetic
+irreversibility below TN. The temperature dependence of the FC magnetization is
+more like a ferromagnet, whereas ZFC magnetization exhibits distinct structures
+not usually observed in the antiferromagnets. In low applied magnetic field
+this thermomagnetic irreversibility in magnetization exists in a subtle way
+even in the paramagnetic regime above TN up to a fairly high temperature, but
+vanishes in high applied magnetic fields. Deviation from CW law and
+irreversibility between ZFC and FC magnetization indicate that the paramagnetic
+state above TN is not a trivial one. Magnetic response below TN changes
+significantly with the increase in the applied magnetic field. Thermomagnetic
+irreversibility in magnetization initially increases with the increase in the
+strength of applied magnetic field, but then gets reduced in the high applied
+fields. A subtle signature of a magnetic field induced phase transition is also
+observed in the isothermal magnetic field vartaion of magnetization. All these
+experimetal results highlight the non-trivial nature of the antiferromagnetic
+state in UO2",2104.11412v1
+1998-01-12,Persistent Currents and Magnetization in two-dimensional Magnetic Quantum Systems,"Persistent currents and magnetization are considered for a two-dimensional
+electron (or gas of electrons) coupled to various magnetic fields.
+Thermodynamic formulae for the magnetization and the persistent current are
+established and the ``classical'' relationship between current and
+magnetization is shown to hold for systems invariant both by translation and
+rotation. Applications are given, including the point vortex superposed to an
+homogeneous magnetic field, the quantum Hall geometry (an electric field and an
+homogeneous magnetic field) and the random magnetic impurity problem (a random
+distribution of point vortices).",9801106v1
+1999-03-20,Magnetism Controlled Vortex Matter,"We discuss a new class of phenomena based on strong interaction between
+magnetic superstructures and vortices in superconductors in combined
+heterogeneous structures. An inhomogeneous magnetization can pin vortices or
+create them spontaneously changing drastically properties of the
+superconductor. On the other hand, the interaction between magnetic moments
+mediated by vortices can result in specific types of magnetic ordering. The
+same interaction can create coupled magnetic-superconducting defects. We
+discuss possible experimental observation of magnetism controlled vortex matter
+in superconducting films with magnetic nanoscale dots or stripes and layered
+systems with alternating superconducting and magnetic layers.",9903312v1
+1999-04-07,Perpendicular transport and magnetization processes in magnetic multilayers with strongly and weakly coupled magnetic layers,"Within the framework of a two-band tight-binding model, we have performed
+calculations of giant magnetoresistance, exchange coupling and thermoelectric
+power (TEP) for a system consisting of three magnetic layers separated by two
+non-magnetic spacers with the first two magnetic layers strongly
+antiferromagnetically exchange-coupled. We have shown how does the GMR relate
+with the corresponding regions of magnetic structure phase diagrams and
+computed some relevant hysteresis loops, too. The GMR may take negative values
+for specific layers thicknesses, and the TEP reveals quite pronounced
+oscillations around a negative bias.",9904086v1
+2003-07-16,Magnetic moment of an electron gas on the surface of constant negative curvature,"The magnetic moment of an electron gas on the surface of constant negative
+curvature is investigated. It is shown that the surface curvature leads to the
+appearance of the region of the monotonic dependence $M(B)$ at low magnetic
+fields. At high magnetic fields, the dependence of the magnetic moment on a
+magnetic field is the oscillating one. The effect of the surface curvature is
+to increase the region of the monotonic dependence of the magnetic moment and
+to break the periodicity of oscillations of the magnetic moment as a function
+of an inverse magnetic field.",0307401v1
+2004-12-27,Magnetization suppression of Type-II Superconductors by external alternating magnetic field,"The effect of suppression of static magnetization of an anisotropic hard
+superconductor by alternating magnetic field is analyzed theoretically. The
+magnetic moment suppression dynamics is described with respect to the
+magnetization loop of the superconductor. It is found that in some cases the
+magnetic moment varies nonmonotonically with the growth in amplitude
+$\mathrm{h}$ of the alternating field. Effect of transition, induced by
+$\mathrm{\mathbf{h}}(t)$, of superconductor form paramagnetic into the
+diamagnetic state is considered. The amplitude of alternating magnetic field
+$\mathrm{h}_{c}(\delta,\vartheta)$ for which the complete suppression of the
+magnetization occurs is calculated as the function of anisotropy parameter
+$\delta$ and it orientation angle $\vartheta$ with respect to the
+crystallographic axes of the sample.",0412695v1
+2010-06-21,Dynamics of magnetic charges in artificial spin ice,"Artificial spin ice has been recently implemented in two-dimensional arrays
+of mesoscopic magnetic wires. We propose a theoretical model of magnetization
+dynamics in artificial spin ice under the action of an applied magnetic field.
+Magnetization reversal is mediated by domain walls carrying two units of
+magnetic charge. They are emitted by lattice junctions when the the local field
+exceeds a critical value $H_c$ required to pull apart magnetic charges of
+opposite sign. Positive feedback from Coulomb interactions between magnetic
+charges induces avalanches in magnetization reversal.",1006.4075v2
+2010-11-08,Neutrino magnetic moment in a magnetized plasma,"The contribution of a magnetized plasma to the neutrino magnetic moment is
+calculated. It is shown that only part of the additional neutrino energy in
+magnetized plasma connecting with its spin and magnetic field strength defines
+the neutrino magnetic moment. It is found that the presence of magnetized
+plasma does not lead to the considerable increase of the neutrino magnetic
+moment in contrast to the results presented in literature previously.",1011.1779v1
+2011-03-08,Permanent magnets including undulators and wigglers,"After a few historic remarks on magnetic materials we introduce the basic
+definitions related to permanent magnets. The magnetic properties of the most
+common materials are reviewed and the production processes are described.
+Measurement techniques for the characterization of macroscopic and microscopic
+properties of permanent magnets are presented. Field simulation techniques for
+permanent magnet devices are discussed. Today, permanent magnets are used in
+many fields. This article concentrates on the applications of permanent magnets
+in accelerators starting from dipoles and quadrupoles on to wigglers and
+undulators.",1103.1573v1
+2013-02-20,Non-magnetic doping induced magnetism in Li doped SnO2 nanoparticles,"We address the possibility of non-magnetic doping induced magnetism, in Li
+doped SnO2 nano-particles. The compounds have been prepared by solid state
+route at equilibrium and were found to be crystallized in single rutile phase.
+The magnetization measurements have shown that Li-doping induces magnetism in
+SnO2 for a particular range of Li concentration. However, for other Li
+concentrations, including pure SnO2, the samples exhibit diamagnetism. To
+investigate the possible origin of the induced magnetism, we have studied the
+variation of the magnetization as a function of the average nano-particle
+radius. Possible scenarios for the appearance of magnetism in these compounds
+are discussed.",1302.4869v1
+2013-12-04,Titan Magnetic Tail: Does its Configuration correspond to the Induced Magnetosphere?,"Magnetic field structure observed in numerous Cassini flybys in the region of
+Titan interaction with the corotating flow of Kronian magnetosheric plasma
+contradicts the classical picture of the ideal induced magnetosphere produced
+by the magnetic field line draping about the obstacle. Clear draping is
+observed only upstream the Titan, but not in the Titan magnetic wake. We
+consider the magnetic field tension downstream the Titan magnetic tail and show
+that the magnetic field direction is not consistent with the induced
+magnetosphere produced by magnetic field lines draping. We arrive at the
+conclusion that the mechanisms alternative to the induced magnetosphere
+formation should be considered for the Titan magnetic surrounding.",1401.3729v1
+2015-06-05,On the magnetization process of ferromagnetic materials,"The present article concludes that a ferromagnetic sample could be considered
+like a paramagnetic system where the role of magnetic moments plays magnetic
+domains. Based on this conclusion and taking into account presence of an
+anisotropic field the formula which describes magnetization dependence on the
+external magnetic field is derived. Expressions for a remanent magnetization
+and a coercive force are presented. The new parameter to characterize a
+magnetic stiffness of a material is introduced. A physical expression for a
+dynamic magnetic susceptibility as a function of material's characteristics,
+external magnetic field, and a temperature is given.",1506.01805v3
+2015-05-19,Electromagnetic acceleration of permanent magnets,"We consider the acceleration of the permanent magnets, consisting of
+neodymium iron boron by means of the running magnetic field gradient. It is
+shown that the specific magnetic moment per nucleon in neodymium iron boron is
+determined by the remained magnetization of the substance. The maximum
+accessable gradient of the magnetic field accelerating the permanent magnets is
+determined by the coercive force thirty kilogauss. For the neodymium iron boron
+magnets this gradient is equal to twenty kilogauss divided by one centimeter.
+The finite velocity of the magnets six kilometers per second, the length of
+acceleration is six hundred thirty-seven meters.",1508.04078v1
+2016-04-03,Soliton collisions in soft magnetic nanotube with uniaxial anisotropy,"The structure of stable magnetic solitons of various orders in soft magnetic
+nanotube with uniaxial magnetic anisotropy has been studied using numerical
+simulation. Solitons of even order are immobile in axially applied magnetic
+field. Odd solitons show decreased mobility with respect to that of head-to
+head domain wall. Solitons of various orders can participate in nanotube
+magnetization reversal process. Various coalescence and decomposition processes
+in soliton assembly are considered. It is shown that the general magnetization
+state of magnetic nanotube consists of chains of magnetic solitons of various
+orders.",1604.00614v1
+2017-01-15,Magnetic Catalysis in Antiferromagnetic Films,"We study the low-temperature behavior of antiferromagnets in two spatial
+dimensions that are subjected to a magnetic field oriented perpendicular to the
+staggered magnetization order parameter. The evaluation of the partition
+function is carried to two-loop order within the systematic effective
+Lagrangian technique. Low-temperature series that are valid in weak magnetic
+and staggered fields are derived for the pressure, staggered magnetization, and
+magnetization. Remarkably, at $T$=0, the staggered magnetization is enhanced by
+the magnetic field, implying that the phenomenon of magnetic catalysis also
+emerges in antiferromagnetic films.",1701.04085v1
+2023-05-26,"Practical Concepts for Design, Construction and Application of Halbach Magnets in Magnetic Resonance","This review is a compilation of relevant concepts in designing Halbach
+multipoles for magnetic resonance applications. The main focus is on providing
+practical guidelines to plan, design and build such magnets. Therefore,
+analytical equations are presented for estimating the magnetic field from ideal
+to realistic systems. Various strategies of homogenizing magnetic fields are
+discussed together with concepts of opening such magnets without force, or
+combining them for variable fields. Temperature compensation and other
+practical aspects are also reviewed. For magnetic resonance two polarities (di-
+and quadrupole) are of main interest, but higher polarities are also included.",2305.17227v2
+2023-08-24,Non-reciprocal coherent all-optical switching between magnetic multi-states,"We present experimental and computational findings of the laser-induced
+non-reciprocal motion of magnetization during ultrafast photo-magnetic
+switching in garnets. We found distinct coherent magnetization precession
+trajectories and switching times between four magnetization states, depending
+on both directions of the light linear polarization and initial magnetic state.
+As a fingerprint of the topological symmetry, the choice of the switching
+trajectory is governed by an interplay of the photo-magnetic torque and
+magnetic anisotropy. Our results open a plethora of possibilities for designing
+energy-efficient magnetization switching routes at arbitrary energy landscapes.",2308.12771v1
+2023-08-28,Revisiting the Wu-Yang approach to magnetic charge,"The Wu-Yang fiber bundle approach to magnetic charge has an overlooked
+feature -- a disk-like sheet current density and associated magnetic field at
+the equator where the Northern hemisphere and Southern hemisphere Dirac string
+vector potentials connect. This disk magnetic field plays a role similar to the
+Dirac string in the Dirac approach to magnetic charge. Placing an electric
+charge near the disk magnetic field gives rise to a non-zero field momentum.
+This implies that the Wu-Yang construction is not a true magnetic charge -- it
+is a Coulomb magnetic field plus a disk magnetic field and planar current
+density.",2308.14706v1
+2024-01-19,Modelling and dynamics of pendulum systems subjected to a nonstationary magnetic field,"The prepared doctoral dissertation focuses on studying dynamics of systems
+composed of magnetic pendulums subjected to a non-stationary magnetic field. A
+magnetic pendulum is a physical pendulum with a magnet attached to its end and
+is placed in an external magnetic field. The non-stationary external magnetic
+field is generated by an electric coil placed under the pendulum and powered by
+a time-varying current signal. The presented research mainly concerns the
+oscillations in one potential well of a single magnetic pendulum, as well as
+the control of the energy flow between two torsionally coupled magnetic
+pendulums.",2401.10594v1
+1999-09-27,Topological Constraints on the Relaxation of Complex Magnetic Fields,"Newly emerging magnetic flux can show a complicated linked or interwoven
+topology of the magnetic field. The complexity of this linkage or knottedness
+of magnetic flux is related to the free energy stored in the magnetic field.
+Magnetic reconnection provides a process to release this energy on the time
+scale of the dynamics. At the same time it approximately conserves the total
+magnetic helicity. Therefore the conservation of total magnetic helicity is a
+crucial constraint for the relaxation of complex magnetic fields. However, the
+total magnetic helicity is only the first, most elementary, quantity of an
+infinite series of topological invariants of the magnetic field. All these
+invariants are strictly conserved in ideal magnetohydrodynamics. As an example
+a preliminary set of these invariants is derived. The relevance of these higher
+order invariants for the final state of relaxation under magnetic reconnection
+and their implications for the release of magnetic energy are discussed.",9909443v1
+2007-10-22,Observation of magnetization reversal and negative magnetization in a double perovskite compound Sr2YbRuO6,"Detailed magnetic properties of the compound Sr2YbRuO6 are presented here.
+The compound belongs to the family of double perovskites forming a monoclinic
+structure. Magnetization meas-urements reveal clear evidence for two components
+of magnetic ordering aligned opposite to each other, leading to a magnetization
+reversal, compensation temperature (T* = 34 K) and neg-ative magnetization at
+low temperatures and low magnetic fields. Heat capacity measurements
+corroborate the presence of two components in the magnetic ordering and a
+noticeable third anomaly at low temperatures (~15 K) which cannot be attributed
+the Schottky effect. The calcu-lated magnetic entropy is substantially lower
+than that expected for the ground states of the or-dered moments of Ru5+ and
+Yb3+, indicating the presence of large crystal field effects and/ or
+in-complete magnetic ordering and/or magnetic frustrations well above the
+magnetic ordering. An attempt is made to explain the magnetization reversal
+within the frameworks of available models.",0710.4043v3
+2008-05-21,Energetic Analysis of Magnetic Transitions in Ultra-small Nanoscopic Magnetic Rings,"In this article, we report on experimental and theoretical investigations of
+magnetic transitions in cobalt rings of size (diameter, width and thickness)
+comparable to the exchange length of cobalt. Magnetization measurements were
+performed for two sets of magnetic ring arrays: ultra-small magnetic rings
+(outer diameter 13 nm, inner diameter 5nm and thickness 5 nm) and small
+thin-walled magnetic rings (outer diameter 150 nm, width 5 nm and thickness 5
+nm). This is the first report on the fabrication and magnetic properties of
+such small rings. Our calculations suggest that if the magnetic ring's sizes
+are comparable to, or smaller than, the exchange length of the magnetic
+material, then only two magnetic states are important - the pure single domain
+state and the flux closure vortex state. The onion-shape magnetic state does
+not arise. Theoretical calculations are based on an energetic analysis of pure
+and slightly distorted single domain and flux closure vortex magnetic states.
+Based on the analytical calculations, a phase diagram is also derived for
+ultra-small ring structures exhibiting the region for vortex magnetic state
+formations as a function of material parameter.",0805.3191v2
+2010-01-29,Orbital magnetization of the electron gas on a two-dimensional kagome lattice under a perpendicular magnetic field,"The orbital magnetization of the electron gas on a two-dimensional kagome
+lattice under a perpendicular magnetic field is theoretically investigated. The
+interplay between the lattice geometry and magnetic field induce nontrivial
+$k$-space Chern invariant in the magnetic Brillouin zone, which turns to result
+in profound effects on the magnetization properties. We show that the
+Berry-phase term in the magnetization gives a paramagnetic contribution, while
+the conventional term brought about by the magnetic response of the magnetic
+Bloch bands produces a diamagnetic contribution. As a result, the superposition
+of these two components gives rise to a delicate oscillatory structure in the
+magnetization curve when varying the electron filling factor. The relationship
+between this oscillatory behavior and the Hofstadter energy spectrum is
+revealed by selectively discussing the magnetization and its two components at
+the commensurate fluxes of $f$=1/4, 1/3, and 1/6, respectively. In particular,
+we reveal as a typical example the fractal structure in the magnetic
+oscillations by tuning the commensurate flux around $f$=1/4. The
+finite-temperature effect on the magnetization is also discussed.",1001.5330v1
+2014-10-08,An optimized magnet for magnetic refrigeration,"A magnet designed for use in a magnetic refrigeration device is presented.
+The magnet is designed by applying two general schemes for improving a magnet
+design to a concentric Halbach cylinder magnet design and dimensioning and
+segmenting this design in an optimum way followed by the construction of the
+actual magnet. The final design generates a peak value of 1.24 T, an average
+flux density of 0.9 T in a volume of 2 L using only 7.3 L of magnet, and has an
+average low flux density of 0.08 T also in a 2 L volume. The working point of
+all the permanent magnet blocks in the design is very close to the maximum
+energy density. The final design is characterized in terms of a performance
+parameter, and it is shown that it is one of the best performing magnet designs
+published for magnetic refrigeration.",1410.1987v1
+2016-12-28,"Magnetic structure of Cu2MnBO5 ludwigite: thermodynamic, magnetic properties and neutron diffraction study","We report on the thermodynamic, magnetic properties and the magnetic
+structure of ludwigite-type Cu2MnBO5. The specific heat, the low-field
+magnetization and the paramagnetic susceptibility were studied on a single
+crystal and combined with powder neutron diffraction data. The temperature
+dependence of the specific heat and the neutron diffraction pattern reveal a
+single magnetic phase transition at T=92 K, which corresponds to the magnetic
+ordering into a ferromagnetic phase. The cation distribution and the values and
+directions of magnetic moments of ions in different crystallographic sites are
+established. The magnetic moments of Cu2+ and Mn3+ ions occupying different
+magnetic sites in the ferrimagnetic phase are pairwise antiparallel and their
+directions do not coincide with the directions of the principal
+crystallographic axes.The small value of the magnetic moment of copper ions
+occupying site 2a is indicative of partial disordering of the magnetic moments
+on this site. The magnetization measurements show a strong temperature
+hysteresis of magnetization, which evidences for field-dependent transitions
+below the phase transition temperature.",1612.08805v1
+2017-12-18,Magnetic and universal magnetocaloric behavior of rare-earth substituted DyFe0.5Cr0.5O3,"We report the effect of partial substitution of Dy-site by rare-earths (R=Gd,
+Er and La)on the magnetic and magnetocaloric behavior of a mixed metal oxide
+DyFe0.5Cr0.5O3.Structural studies reveal that substitution of Dy by R has a
+minimal influence on the crystal structure. Magnetic and heat capacity studies
+show that the magnetic transition around 121 K observed for DyFe0.5Cr0.5O3
+remains unchanged with rare-earth substitution, whereas the lower magnetic
+transition temperature is suppressed/enhanced by magnetic/non-magnetic
+substitution. In all these compounds, the second order nature of magnetic
+transition is confirmed by Arrott plots. As compared to DyFe0.5Cr0.5O3, the
+values of magnetic entropy change and relative cooling power are increased with
+magnetic rare-earth substitution while it decreases with non-magnetic
+rare-earth substitution. In all these compounds, magnetic entropy change
+follows the power law dependence of magnetic field and the value of the
+exponent n indicate the presence of ferromagnetic correlation in an
+antiferromagnetic state. A phenomenological universal master curve is also
+constructed for all the compounds by normalizing the entropy change with
+rescaled temperature using a single reference temperature. This master curve
+also reiterates the second order nature of the magnetic phase transition in
+such mixed metal oxides.",1712.06396v1
+2018-02-08,Nonspecific biological effects of weak magnetic fields depend on molecular rotations,"The radical pair mechanism is a leading hypothesis in animal magnetic
+navigation. This mechanism associates the magnetic sense with the visual
+system, the radical pairs in cryptochromes of the eye retina being specialized
+magnetic receptors that modulate rhodopsin-mediated photoreception. There are
+also nonspecific magnetic effects in biology, which occur mostly by chance and
+originate from the interaction of weak magnetic fields with the magnetic
+moments dispersed all over the organism at the microscopic level. The radical
+pair mechanism cannot explain this type of response for many reasons. We have
+previously shown that the above interaction has a finite probability of
+resulting in an observable. Here, we develop our physical model of nonspecific
+magnetic effects for the case of magnetic moments located in rotating
+molecules. We generalize the results of recent experiments on gene expression
+in plants in a constant magnetic field, and show that the precession of the
+magnetic moments that reside on rotating molecules can be slowed relative to
+the immediate biophysical structures. In quantum mechanical language, the
+crossing of the quantum levels of magnetic moments conjointly with molecular
+rotations explain nonspecific magnetic effects and leads to magnetic
+field-dependences that are in good agreement with the experiment.",1802.02903v1
+2019-05-22,"Effect of doping of Co, Ni and Ga on magnetic and dielectric properties of layered perovskite multiferroic YBaCuFeO5","YBaCuFeO5 is one of the interesting multiferroic compounds, which exhibits
+magnetic ordering and dielectric anomaly above 200 K. Partial substitution of
+Fe with other magnetic and non-magnetic ion affects the magnetic and the
+structural properties of the system. We report detailed investigation of
+structural, magnetic and dielectric properties of YBaCuFe0.85M0.15O5 (M=Co, Ni
+and Ga). We observed that the partial replacement of Ni and Co in place of Fe,
+results in magnetic dilution and broadening of the magnetic transition and
+shifting towards lower temperature. The replacement of Fe with non-magnetic Ga
+also results in shifting of the magnetic transition to the lower temperature
+side. The observed dielectric relaxation behavior in these compounds is due to
+the charge carrier hoping. This study highlights the impacts of magnetic and
+non-magnetic doping at the magnetic site on magnetic and dielectric properties
+in layered perovskite compound YBaCuFeO5.",1905.08982v2
+2019-11-08,Magnetic glassy state at low spin state of Co3+ in EuBaCo2O5+δ (δ = 0.47) cobaltite,"The magnetic glassy state is a fascinating phenomenon, which results from the
+kinetic arrest of the first order magnetic phase transition. Interesting
+properties, such as metastable magnetization and nonequilibrium magnetic
+phases, are naturally developed in the magnetic glassy state. Here, we report
+magnetic glass property in the low spin state of Co3+ in EuBaCo2O5+{\delta}
+({\delta} = 0.47) cobaltite at low temperature (T < 60 K). The measurements of
+magnetization under the cooling and heating in unequal fields, magnetization
+relaxation and thermal cycling of magnetization show the kinetic arrest of low
+magnetization state below 60 K. The kinetically arrested low temperature
+magnetic phase is further supported through the study of isothermal magnetic
+entropy, which shows the significant entropy change. The present results will
+open a new window to search the microscopic relation between the spin state
+transitions and the kinetic arrest induced magnetic glassy phenomena in complex
+materials.",1911.03258v1
+2020-07-17,Unraveling nanoscale magnetic ordering in Fe3O4 nanoparticle assemblies via x-rays,": Understanding the correlations between magnetic nanoparticles is important
+for nanotechnologies, such as high-density magnetic recording and biomedical
+applications, where functionalized magnetic particles are used as contrast
+agents and for drug delivery. The ability to control the magnetic state of
+individual particles depends on the good knowledge of magnetic correlations
+between particles when assembled. Inaccessible via standard magnetometry
+techniques, nanoscale magnetic ordering in self-assemblies of Fe3O4
+nanoparticles is here unveiled via x-ray resonant magnetic scattering (XRMS).
+Measured throughout the magnetization process, the XRMS signal reveals
+size-dependent inter-particle magnetic correlations. Smaller (5 nm) particles
+show little magnetic correlation, even when tightly close-packed, yielding to
+mostly magnetic disorder in the absence of external field, which is
+characteristic of superparamagnetic behavior. In contrast, larger (11 nm)
+particles tend to be strongly correlated, yielding a mix of magnetic orders
+including ferromagnetic and anti-ferromagnetic orders. These strong magnetic
+correlations are present even when the particles are sparsely distributed.",2007.09226v1
+2021-12-02,Magnetic correction to the Anomalous Magnetic Moment of Electron,"We investigate the leading order correction of anomalous magnetic moment
+(AMM) to the electron in weak magnetic field and find that the magnetic
+correction is negative and magnetic field dependent, indicating a magnetic
+catalysis effect for the electron gas. In the laboratory to measure the $g-2$,
+the magnitude of the magnetic field $B$ is several $\mathrm{T}$,
+correspondingly the magnetic correction to the AMM of electron/muon is around
+$10^{-34}$/$10^{-42}$, therefore the magnetic correction can be safely
+neglected in current measurement. However, when the magnitude of the magnetic
+field strength is comparable with the electron mass, the magnetic correction of
+electron's AMM will become considerable. This general magnetic correction to
+charged fermion's AMM can be extended to study QCD matter under strong magnetic
+field.",2112.01051v1
+2022-08-07,Mixels: Fabricating Interfaces using Programmable Magnetic Pixels,"In this paper, we present Mixels, programmable magnetic pixels that can be
+rapidly fabricated using an electromagnetic printhead mounted on an
+off-the-shelve 3-axis CNC machine. The ability to program magnetic material
+pixel-wise with varying magnetic force enables Mixels to create new tangible,
+tactile, and haptic interfaces. To facilitate the creation of interactive
+objects with Mixels, we provide a user interface that lets users specify the
+high-level magnetic behavior and that then computes the underlying magnetic
+pixel assignments and fabrication instructions to program the magnetic surface.
+Our custom hardware add-on based on an electromagnetic printhead and hall
+effect sensor clips onto a standard 3-axis CNC machine and can both write and
+read magnetic pixel values from magnetic material. Our evaluation shows that
+our system can reliably program and read magnetic pixels of various strengths,
+that we can predict the behavior of two interacting magnetic surfaces before
+programming them, that our electromagnet is strong enough to create pixels that
+utilize the maximum magnetic strength of the material being programmed, and
+that this material remains magnetized when removed from the magnetic plotter.",2208.03804v1
+1998-10-20,HST Observations of the Broad Absorption Line Quasar PG 0946+301,"We analyze HST and ground based spectra of the brightest BALQSO in the UV:
+PG~0946+301. A detailed study of the absorption troughs as a function of
+velocity is presented, facilitated by the use of a new algorithm to solve for
+the optical depth as a function of velocity for multiplet lines. We find
+convincing evidence for saturation in parts of the troughs. This supports our
+previous assertion that saturation is common in BALs and therefore cast doubts
+on claims for very high metallicity in BAL flows. Due to the importance of BAL
+saturation we also discuss its evidence in other objects. In PG~0946+301 large
+differences in ionization as a function of velocity are detected and our
+findings supports the hypothesis that the line of sight intersects a number of
+flow components that combine to give the appearance of the whole trough. Based
+on the optical depth profiles, we develop a geometrical-kinematical model for
+the flow. We have positively identified 16 ions of 8 elements (H~I, C~III,
+C~IV, N~III, N~IV, N~V, O~III, O~IV, O~V, O~VI, Ne~V, Ne~VIII, P~V, Si~IV, S~V,
+S~VI) and have a probable identifications of Mg~X and S~IV. Unlike earlier
+analysis of IUE data, we find no evidence for BALs arising from excited ionic
+states in the HST spectrum of PG~0946+301.",9810309v1
+2003-02-17,Time evolution of X-ray coronal activity in PMS stars; a possible relation with the evolution of accretion disks,"We investigate the evolution of X-ray stellar activity from the age of the
+youngest known star forming regions (SFR), < 1Myr, to about 100 Myr, i.e. the
+zero age main sequence (ZAMS) for a ~ 1M_sun star. We consider five SFR of
+varying age (Rho Ophiuchi, the Orion Nebula Cluster, NGC 2264, Chamaeleon I,
+and Eta Chamaeleontis) and two young clusters (the Pleiades and NGC 2516).
+Optical and X-ray data for these regions are retrieved both from archival
+observations and recent literature, and reanalyzed here in a consistent manner
+so to minimize systematic differences in the results. We study trends of L_X
+and L_X/L_bol as a function of stellar mass and association age. For low mass
+stars (M < 1M_sun) we observe an increase in L_X/L_bol in the first 3-4 Myr and
+a subsequent leveling off at the saturation level (L_X/L_bol ~ -3). Slowly
+evolving very low mass stars then retain saturated levels down to the oldest
+ages here considered, while for higher mass stars activity begins to decline at
+some age after ~10^7 years. We find our data consistent with the following
+tentative picture: low mass PMS stars with no circumstellar accretion disk have
+saturated activity, consistently with the activity-Rossby number relation
+derived for MS stars. Accretion and/or the presence of disks somehow lowers the
+observed activity levels; disk dissipation and/or the decrease of mass
+accretion rate in the first few Myrs of PMS evolution is therefore responsible
+for the observed increase of L_X/L_bol with time.",0302329v1
+2004-06-10,A more informative picture of the HST Ultra Deep Field,"The Hubble Space Telescope has obtained some of its well-deserved impact by
+producing stunning three-color (RGB) pictures from three-band imaging data.
+Here we produce a new RGB representation of the $I$, $V$, and $B$ bandpass
+images of the HST Ultra Deep Field (HUDF). Our representation is based on
+principles set forth elsewhere (Lupton et al 2004, PASP, 116, 133--137). The
+principal difference between our RGB representation of the data and the more
+traditional representation provided by the Space Telescope Science Institute is
+that the (necessarily) nonlinear transformation between data values and RGB
+values is done in a color-preserving (i.e., hue- and saturation-preserving)
+way. For example, if one of the image pixel values saturates the dynamic range
+of the RGB representation, all three of the R, G, and B values in the
+representation are truncated such that the hue and saturation of the pixel is
+the same as it would have been if the pixel had had lower flux but the same
+astronomical color. This, in effect, makes the bright parts of the
+representation an informative color map, not ""whited out"" as they are in
+traditional representations. For the HUDF, this difference is seen best in the
+centers of bright galaxies, which show significant detail not visible in the
+more traditional representation.",0406274v2
+2004-07-19,On the saturation of corotation resonances: a numerical study,"[Abridged] The torque exerted by an external potential on a two-dimensional
+gaseous disk at non-co-orbital corotation resonances is studied by means of
+numerical simulations. The degree of saturation of these resonances is
+important in determining whether an eccentric giant planet embedded in a
+protoplanetary disk experiences an eccentricity excitation or damping. We
+perform calculations restricted to one or two resonances to investigate the
+properties of two neighboring corotation resonances, as well as the properties
+of a corotation resonance that overlaps a Lindblad resonance. We find that
+these properties hardly differ from the case of an isolated corotation
+resonance. In particular, although the torque of two neighboring corotation
+resonances may differ from the sum of the torques of the corresponding
+resonances considered as isolated, it never exceeds the sum of the fully
+unsaturated isolated corotation resonances, and it saturates in a fashion
+similar to an isolated resonance. Similarly, the presence of an underlying
+Lindblad resonance hardly affects the corotation torque, even if that resonance
+implies a torque strong enough to significantly redistribute the azimuthally
+averaged surface density profile, in which case the corotation torque scales
+with the resulting vortensity gradient. This set of numerical experiments thus
+essentially validates previous analytic studies. As a side result, we show that
+corotation libration islands misrepresented by a mesh of too low resolution can
+lead to a strongly overestimated corotation torque. This may be an explanation
+why the eccentricity of embedded Jupiter-sized planets was never observed to
+undergo an excitation in the numerical simulations performed so far.",0407403v1
+2004-07-22,The nature of premaximum halts of classical nova outbursts: V723 Cassiopeiae and V463 Scuti,"We present a new interpretation of long premaximum halts of nova outbursts.
+For V723 Cas (Nova Cas 1995) and V463 Sct (Nova Sct 2000), we have reproduced
+light curves, excluding the brightness maxima, starting from the long
+premaximum halt through the late decay phase of the outbursts using a
+steady-state optically thick wind model. When the hydrogen-rich envelope of the
+white dwarf (WD) is massive enough, the star expands to \sim 100 R_\sun or over
+and its surface temperature decreases to below 7000 K. At this supergiant
+mimicry stage, the changes in both the photospheric radius and the temperature
+are small against the large increase in the envelope mass. These changes cause
+a saturation in visual magnitude that lasts a long time before it begins to
+decline. This saturation is known as the premaximum halt of a classical nova
+outburst. The visual magnitude during the saturation is close to the bolometric
+magnitude, which is an upper limit for a given WD mass. Since the WD masses are
+estimated to be 0.59 M_\sun for V723 Cas and 1.1 M_\sun for V463 Sct by fitting
+the decline rate of nova light curves, we can determine the absolute magnitude
+of premaximum halts. It is a refined Eddington luminosity. Thus, the premaximum
+halt of a nova works as a standard candle.",0407471v2
+2006-04-11,Accurate Astrometry and Photometry of Saturated and Coronagraphic Point Spread Functions,"Accurate astrometry and photometry of saturated and coronagraphic point
+spread functions (PSFs) are fundamental to both ground- and space-based high
+contrast imaging projects. For ground-based adaptive optics imaging,
+differential atmospheric refraction and flexure introduce a small drift of the
+PSF with time, and seeing and sky transmission variations modify the PSF flux
+distribution. For space-based imaging, vibrations, thermal fluctuations and
+pointing jitters can modify the PSF core position and flux. These effects need
+to be corrected to properly combine the images and obtain optimal
+signal-to-noise ratios, accurate relative astrometry and photometry of detected
+objects as well as precise detection limits. Usually, one can easily correct
+for these effects by using the PSF core, but this is impossible when high
+dynamic range observing techniques are used, like coronagrahy with a
+non-transmissive occulting mask, or if the stellar PSF core is saturated. We
+present a new technique that can solve these issues by using off-axis satellite
+PSFs produced by a periodic amplitude or phase mask conjugated to a pupil
+plane. It will be shown that these satellite PSFs track precisely the PSF
+position, its Strehl ratio and its intensity and can thus be used to register
+and to flux normalize the PSF. A laboratory experiment is also presented to
+validate the theory. This approach can be easily implemented in existing
+adaptive optics instruments and should be considered for future extreme
+adaptive optics coronagraph instruments and in high-contrast imaging space
+observatories.",0604256v1
+2001-06-27,Angle of repose and segregation in cohesive granular matter,"We study the effect of fluids on the angle of repose and the segregation of
+granular matter poured into a silo. The experiments are conducted in two
+regimes where: (i) the volume fraction of the fluid is small and it forms
+liquid bridges between particles, and (ii) the particles are completely
+immersed in the fluid. The data is obtained by imaging the pile formed inside a
+quasi-two dimensional silo through the transparent glass side walls. In the
+first series of experiments, the angle of repose is observed to increase
+sharply with the volume fraction of the fluid and then saturates at a value
+that depends on the size of the particles. We systematically study the effect
+of viscosity by using water-glycerol mixtures to vary it over at least three
+orders of magnitude while keeping the surface tension almost constant. Besides
+surface tension, the viscosity of the fluid is observed to have an effect on
+the angle of repose and the extent of segregation. In case of bidisperse
+particles, segregation is observed to decrease and finally saturate depending
+on the size ratio of the particles and the viscosity of the fluid. The sharp
+initial change and the subsequent saturation in the extent of segregation and
+angle of repose occurs over similar volume fraction of the fluid. In the second
+series of experiments, particles are poured into a container filled with a
+fluid. Although the angle of repose is observed to be unchanged, segregation is
+observed to decrease with an increase in the viscosity of the fluid.",0106572v1
+2004-06-10,"Cluster growth in far-from-equilibrium particle models with diffusion, detachment, reattachment and deposition","Monolayer cluster growth in far-from-equilibrium systems is investigated by
+applying simulation and analytic techniques to minimal hard core particle
+(exclusion) models. The first model (I), for post-deposition coarsening
+dynamics, contains mechanisms of diffusion, attachment, and slow activated
+detachment (at rate epsilon<<1) of particles on a line. Simulation shows three
+successive regimes of cluster growth: fast attachment of isolated particles;
+detachment allowing further (epsilon t)^(1/3) coarsening of average cluster
+size; and t^(-1/2) approach to a saturation size going like epsilon^(-1/2).
+Model II generalizes the first one in having an additional mechanism of
+particle deposition into cluster gaps, suppressed for the smallest gaps. This
+model exhibits early rapid filling, leading to slowing deposition due to the
+increasing scarcity of deposition sites, and then continued power law (epsilon
+t)^(1/2) cluster size coarsening through the redistribution allowed by slow
+detachment. The basic (epsilon t)^(1/3) domain growth laws and epsilon^(-1/2)
+saturation in model I are explained by a simple scaling picture. A second,
+fuller approach is presented which employs a mapping of cluster configurations
+to a column picture and an approximate factorization of the cluster
+configuration probability within the resulting master equation. This allows
+quantitative results for the saturation of model I in excellent agreement with
+the simulation results. For model II, it provides a one-variable scaling
+function solution for the coarsening probability distribution, and in
+particular quantitative agreement with the cluster length scaling and its
+amplitude.",0406252v1
+2006-11-06,Some aspects of electrical conduction in granular systems of various dimensions,"We report on measurements of the electrical conductivity in both a 2D
+triangular lattice of metallic beads and in a chain of beads. The
+voltage/current characteristics are qualitatively similar in both experiments.
+At low applied current, the voltage is found to increase logarithmically in a
+good agreement with a model of widely distributed resistances in series. At
+high enough current, the voltage saturates due to the local welding of
+microcontacts between beads. The frequency dependence of the saturation voltage
+gives an estimate of the size of these welded microcontacts. The DC value of
+the saturation voltage (~ 0.4 V per contact) gives an indirect measure of the
+number of welded contact carrying the current within the 2D lattice. Also, a
+new measurement technique provides a map of the current paths within the 2D
+lattice of beads. For an isotropic compression of the 2D granular medium, the
+current paths are localized in few discrete linear paths. This
+quasi-onedimensional nature of the electrical conductivity thus explains the
+similarity between the characteristics in the 1D and 2D systems.",0611135v2
+2007-03-16,Dimension and Relative Frequencies,"We show how to calculate the finite-state dimension (equivalently, the
+finite-state compressibility) of a saturated sets $X$ consisting of {\em all}
+infinite sequences $S$ over a finite alphabet $\Sigma_m$ satisfying some given
+condition $P$ on the asymptotic frequencies with which various symbols from
+$\Sigma_m$ appear in $S$. When the condition $P$ completely specifies an
+empirical probability distribution $\pi$ over $\Sigma_m$, i.e., a limiting
+frequency of occurrence for {\em every} symbol in $\Sigma_m$, it has been known
+since 1949 that the Hausdorff dimension of $X$ is precisely $\CH(\pi)$, the
+Shannon entropy of $\pi$, and the finite-state dimension was proven to have
+this same value in 2001.
+  The saturated sets were studied by Volkmann and Cajar decades ago. It got
+attention again only with the recent developments in multifractal analysis by
+Barreira, Saussol, Schmeling, and separately Olsen. However, the powerful
+methods they used -- ergodic theory and multifractal analysis -- do not yield a
+value for the finite-state (or even computable) dimension in an obvious manner.
+  We give a pointwise characterization of finite-state dimensions of saturated
+sets. Simultaneously, we also show that their finite-state dimension and strong
+dimension coincide with their Hausdorff and packing dimension respectively,
+though the techniques we use are completely elementary. Our results
+automatically extend to less restrictive effective settings (e.g.,
+constructive, computable, and polynomial-time dimensions).",0703085v1
+2000-06-21,Cosmology with Curvature-Saturated Gravitational Lagrangian R/\sqrt{1 + l^4 R^2},"We argue that the Lagrangian for gravity should remain bounded at large
+curvature, and interpolate between the weak-field tested Einstein-Hilbert
+Lagrangian L_EH = R /16 pi G and a pure cosmological constant for large R with
+the curvature-saturated ansatz L_cs=L_EH/ \sqrt{1+l^4 R^2}, where l is a length
+parameter expected to be a few orders of magnitude above the Planck length. The
+curvature-dependent effective gravitational constant defined by dL/dR = 1/16 pi
+G_eff is G_eff = G \sqrt{1+l^4 R^2}^{3}, and tends to infinity for large $R$,
+in contrast to most other approaches where G_eff-> 0. The theory possesses
+neither ghosts nor tachyons. In a curvature-saturated cosmology, the
+coordinates with ds^2 = a^2 [da^2/B(a) - dx^2 - dy^2- dz^2] are most convenient
+since the curvature scalar becomes a linear function of $B(a)$. Solutions with
+a big-bang singularity have a much milder behavior of the curvature than in
+Einstein's theory. In synchronized time, the metric is given by ds^2 = dt^2 -
+t^{6/5(dx^2 + dy^2+ dz^2). On the technical side we show that two different
+conformal transformations make L_cs asymptotically equivalent to the
+Gurovich-ansatz L= | R |^{4/3} on the one hand, and to Einstein's theory with a
+minimally coupled scalar field with self-interaction on the other.",0006074v2
+1996-09-18,Avoidance of Collapse by Circular Current-Carrying Cosmic String Loops,"Earlier attempts to calculate the nonlinear dynamical evolution of Witten
+type superconducting vacuum vortex defects relied on the use of approximate
+conducting string models that were too simple to take proper account of the
+effect of current saturation. This effect is however allowed for adequately in
+a newly developed class of rather more complicated, though still conveniently
+analytic, conducting string models. These more realistic models have recently
+been employed by Larsen and Axenides for investigating the collapse of circular
+string loops in the case for which angular momentum is absent. The present work
+extends this investigation to the generic case of circular string loops for
+which angular momentum is present, so that there will be a centrifugal
+potential barrier. This barrier will prevent collapse unless the initial
+conditions are such that the relevant current saturation limit is attained, in
+which case the string description of the vortex defect will break down, so that
+its subsequent fate is hard to foresee. On the other hand if saturation is
+avoided one would expect that the loop will eventually radiate away its excess
+energy and settle down into a vorton type equilibrium state.",9609401v1
+2002-11-22,QCD Saturation and $γ^*-γ^*$ Scattering,"Two photon collisions at high energy have an important theoretical advantage:
+the simplicity of the initial state, which gives us a unique opportunity to
+calculate these processes for large virtualities of both photons in
+perturbative QCD approach. In this paper we study QCD saturation in two photon
+collisions in the framework of the Glauber-Mueller approach. The
+Glauber-Mueller formula is derived emphasizing the impact parameter dependence
+($b_t$) of the dipole-dipole amplitude. It is shown that non-perturbative QCD
+contributions are needed to describe large $b_t $-behaviour, and the way how to
+deal with them is suggested. Our approach can be viewed as the model for the
+saturation in which the entire impact parameter dependence is determined by the
+initial conditions. The unitarity bound for the total cross section, its energy
+dependence as well aspredictions for future experiments are discussed.It is
+argued that the total cross section increases faster than any power of $
+\log(1/x)$ in a wide range of energy or $x$, namely $\sigma(\gamma^*-\gamma^*)
+  \propto (1/Q^2) exp(a \sqrt{\ln(1/x)}) \leq 1/m^2_{\pi}$ where $exp(a
+\sqrt{\ln(1/x)})$ reflects the $x$ dependence of the gluon density $xG \propto
+exp(2 a \sqrt{\ln(1/x)})$ and $m_{\pi}$ is the pion mass.",0211348v2
+2005-05-06,Saturation Physics and Deuteron--Gold Collisions at RHIC,"We present a review of parton saturation/Color Glass Condensate physics in
+the context of deuteron-gold ($d+Au$) collisions at RHIC. Color Glass
+Condensate physics is a universal description of all high energy hadronic and
+nuclear interactions. It comprises classical (McLerran-Venugopalan model and
+Glauber-Mueller rescatterings) and quantum evolution (JIMWLK and BK equations)
+effects both in small-$x$ hadronic and nuclear wave functions and in the high
+energy scattering processes. Proton-nucleus (or $d+A$) collisions present a
+unique opportunity to study Color Glass Condensate predictions, since many
+relevant observables in proton-nucleus collisions are reasonably
+well-understood theoretically in the Color Glass Condensate approach. In this
+article we review the basics of saturation/Color Glass Condensate physics and
+reproduce derivations of many important observables in proton
+(deuteron)--nucleus collisions. We compare the predictions of Color Glass
+physics to the data generated by $d+Au$ experiments at RHIC and observe an
+agreement between the data and the theory, indicating that Color Glass
+Condensate has probably been discovered at RHIC. We point out further
+experimental measurements which need to be carried out to test the discovery.",0505052v2
+1997-07-18,No saturation of the quantum Bogomolnyi bound by two-dimensional supersymmetric solitons,"We reanalyse the question whether the quantum Bogomolnyi bound is saturated
+in the two-dimensional supersymmetric kink and sine-Gordon models. Our starting
+point is the usual expression for the one-loop correction to the mass of a
+soliton in terms of sums over zero-point energies. To regulate these sums, most
+authors put the system in a box with suitable boundary conditions, and impose
+an ultraviolet cut-off. We distinguish between an energy cut-off and a mode
+number cut-off, and show that they lead to different results. We claim that
+only the mode cut-off yields correct results, and only if one considers exactly
+the same number of bosonic and fermionic modes in the total sum over
+bound-state and zero-point energies. To substantiate this claim, we show that
+in the sine-Gordon model only the mode cut-off yields a result for the quantum
+soliton mass that is consistent with the exact result for the spectrum as
+obtained by Dashen et al. from quantising the so-called breather solution. In
+the supersymmetric case, our conclusion is that contrary to previous claims the
+quantum Bogomolnyi bound is not saturated in any of the two-dimensional models
+considered.",9707163v1
+1998-10-28,Non-Extreme Black Holes of Five Dimensional N=2 AdS Supergravity,"We derive and analyse the full set of equations of motion for non-extreme
+static black holes (including examples with the spatial curvatures k=-1 and
+k=0) in D=5 N=2 gauged supergravity by employing the techniques of ""very
+special geometry"". These solutions turn out to differ from those in the
+ungauged supergravity only in the non-extremality function, which has an
+additional term (proportional to the gauge coupling g), responsible for the
+appearance of naked singularities in the BPS-saturated limit. We derive an
+explicit solution for the STU model of gauged supergravity which is
+incidentally also a solution of D=5 N=4 and N=8 gauged supergravity. This
+solution is specified by three charges, the asymptotic negative cosmological
+constant (minimum of the potential) and a non-extremality parameter. While its
+BPS-saturated limit has a naked singularity, we find a lower bound on the
+non-extremality parameter (or equivalently on the ADM mass) for which the
+non-extreme solutions are regular. When this bound is saturated the extreme
+(non-supersymmetric) solution has zero Hawking temperature and finite entropy.
+Analogous qualitative features are expected to emerge for black hole solutions
+in D=4 gauged supergravity as well.",9810227v2
+2006-01-20,The Viscosity Bound Conjecture and Hydrodynamics of M2-Brane Theory at Finite Chemical Potential,"Kovtun, Son and Starinets have conjectured that the viscosity to entropy
+density ratio $\eta/s$ is always bounded from below by a universal multiple of
+$\hbar$ i.e., $\hbar/(4\pi k_{B})$ for all forms of matter. Mysteriously, the
+proposed viscosity bound appears to be saturated in all computations done
+whenever a supergravity dual is available. We consider the near horizon limit
+of a stack of M2-branes in the grand canonical ensemble at finite R-charge
+densities, corresponding to non-zero angular momentum in the bulk. The
+corresponding four-dimensional R-charged black hole in Anti-de Sitter space
+provides a holographic dual in which various transport coefficients can be
+calculated. We find that the shear viscosity increases as soon as a background
+R-charge density is turned on. We numerically compute the few first corrections
+to the shear viscosity to entropy density ratio $\eta/s$ and surprisingly
+discover that up to fourth order all corrections originating from a non-zero
+chemical potential vanish, leaving the bound saturated. This is a sharp signal
+in favor of the saturation of the viscosity bound for event horizons even in
+the presence of some finite background field strength. We discuss implications
+of this observation for the conjectured bound.",0601159v3
+2005-08-30,Hybrid Shrinkage Estimators Using Penalty Bases For The Ordinal One-Way Layout,"This paper constructs improved estimators of the means in the Gaussian
+saturated one-way layout with an ordinal factor. The least squares estimator
+for the mean vector in this saturated model is usually inadmissible. The hybrid
+shrinkage estimators of this paper exploit the possibility of slow variation in
+the dependence of the means on the ordered factor levels but do not assume it
+and respond well to faster variation if present. To motivate the development,
+candidate penalized least squares (PLS) estimators for the mean vector of a
+one-way layout are represented as shrinkage estimators relative to the penalty
+basis for the regression space. This canonical representation suggests further
+classes of candidate estimators for the unknown means: monotone shrinkage (MS)
+estimators or soft-thresholding (ST) estimators or, most generally, hybrid
+shrinkage (HS) estimators that combine the preceding two strategies. Adaptation
+selects the estimator within a candidate class that minimizes estimated risk.
+Under the Gaussian saturated one-way layout model, such adaptive estimators
+minimize risk asymptotically over the class of candidate estimators as the
+number of factor levels tends to infinity. Thereby, adaptive HS estimators
+asymptotically dominate adaptive MS and adaptive ST estimators as well as the
+least squares estimator. Local annihilators of polynomials, among them
+difference operators, generate penalty bases suitable for a range of numerical
+examples.",0508599v1
+2006-09-11,Thresholds for breather solutions on the Discrete Nonlinear Schrödinger Equation with saturable and power nonlinearity,"We consider the question of existence of periodic solutions (called breather
+solutions or discrete solitons) for the Discrete Nonlinear Schr\""odinger
+Equation with saturable and power nonlinearity. Theoretical and numerical
+results are proved concerning the existence and nonexistence of periodic
+solutions by a variational approach and a fixed point argument. In the
+variational approach we are restricted to DNLS lattices with Dirichlet boundary
+conditions. It is proved that there exists parameters (frequency or
+nonlinearity parameters) for which the corresponding minimizers satisfy
+explicit upper and lower bounds on the power. The numerical studies performed
+indicate that these bounds behave as thresholds for the existence of periodic
+solutions. The fixed point method considers the case of infinite lattices.
+Through this method, the existence of a threshold is proved in the case of
+saturable nonlinearity and an explicit theoretical estimate which is
+independent on the dimension is given. The numerical studies, testing the
+efficiency of the bounds derived by both methods, demonstrate that these
+thresholds are quite sharp estimates of a threshold value on the power needed
+for the the existence of a breather solution. This it justified by the
+consideration of limiting cases with respect to the size of the nonlinearity
+parameters and nonlinearity exponents.",0609023v2
+2005-06-16,Effective mass and decay of $Θ^+$ in nuclear matter in quark-meson coupling model,"The in-medium mass of a $\thetaplus$, $\mtheta^*$, in cold symmetric nuclear
+matter is calculated by using the quark-meson coupling model. The $\Theta^+$ is
+treated as an MIT bag with the quark content $uudd\bar s$. Bag parameters for a
+free $\thetaplus$ are fixed to reproduce the observed mass of the $\thetaplus$.
+In doing so, we use three different values of the $s$-quark mass since the mass
+of the $s$-quark is not well known. As usual, the strengths of the $u$ and $d$
+quark couplings to $\sigma$- and $\omega$-meson fields are determined to fit
+the nuclear saturation properties. However, the coupling constant $g_\sigma^s$
+between the $s$-quark and the $\sigma$-meson cannot be fixed from the
+saturation properties, and thus we treat $g_\sigma^s$ as a free parameter and
+investigate how $\mtheta^*$ depends on $g_\sigma^s$. %$\mtheta^*$ is calculated
+up to 2.5 times the nuclear saturation density, %and we find that We find that
+$\mtheta^*$ depends significantly on the value of $g_\sigma^s$ but not on the
+mass of the $s$-quark. Chemical potentials of the $\Theta^+$ and the $K+N$
+system are calculated to discuss the decay of a $\Theta^+$ in nuclear matter.
+We calculate the effective mass of a kaon in nuclear matter in two ways; using
+the optical potential of $K^-$ in matter and using quark model. By comparing
+the effective masses calculated from these two methods, we find the magnitude
+of the real part of the optical potential that is consistent with the usual
+quark model is about 100 MeV.",0506052v1
+2005-07-06,Relativistic Transport Approach to Collective Nuclear Dynamics,"The isoscalar giant monopole resonance (ISGMR) and isovector giant dipole
+resonance (IVGDR) in finite nuclei are studied in the framework of a
+relativistic transport approach. The kinetic equations are derived within an
+effective nucleon-meson field theory in the Relativistic Mean Field (RMF)
+scheme, even extended to density dependent vertices. Small amplitude
+oscillations are analysed using the Relativistic Vlasov (RV) approach, i.e.
+neglecting nucleon collision terms. The time evolution of the isoscalar
+monopole moment and isovector dipole moment and the corresponding Fourier power
+spectra are discussed. In the case of ^{208}Pb we study in detail the
+dependence of the monopole response on the effective mass and symmetry energy
+at saturation given by the used covariant effective interaction. We show that a
+reduced m^* and a larger a_4 can compensate the effect on the ISGMR energy
+centroid of a much larger compressibility modulus K_{nm}. This result is
+important in order to overcome the conflicting determination of the nuclear
+compressibility between non-relativistic and relativistic effective
+interactions. For the symmetry energy dynamical effects, we carefully analyze
+the influence of the inclusion of an effective isovector scalar channel,
+  \delta-meson field, with constant and density dependent couplings. We show
+the relevance of the $slope$ (or pressure) of the symmetry energy at saturation
+on the ISGMR and IVGDR modes for neutron-rich systems. Density dependent
+vertices are not much affecting our conclusions. Following as a guidance some
+extended dispersion relations in nuclear matter, we see two main reasons for
+that, the smoothness of the density dependences around saturation and the
+presence of compensation effects coming from rearrangement terms.",0507014v1
+2006-01-31,Equation of state for isospin asymmetric nuclear matter using Lane potential,"A mean field calculation for obtaining the equation of state (EOS) for
+symmetric nuclear matter from a density dependent M3Y interaction supplemented
+by a zero-range potential is described. The energy per nucleon is minimized to
+obtain the ground state of symmetric nuclear matter. The saturation energy per
+nucleon used for nuclear matter calculations is determined from the
+co-efficient of the volume term of Bethe-Weizs\""acker mass formula which is
+evaluated by fitting the recent experimental and estimated atomic mass excesses
+from Audi-Wapstra-Thibault atomic mass table by minimizing the mean square
+deviation. The constants of density dependence of the effective interaction are
+obtained by reproducing the saturation energy per nucleon and the saturation
+density of spin and isospin symmetric cold infinite nuclear matter. The EOS of
+symmetric nuclear matter, thus obtained, provide reasonably good estimate of
+nuclear incompressibility. Once the consants of density dependence are
+determined, EOS for asymmetric nuclear matter is calculated by adding to the
+isoscalar part, the isovector component of the M3Y interaction that do not
+contribute to the EOS of symmetric nuclear matter. These EOS are then used to
+calculate the pressure, the energy density and the velocity of sound in
+symmetric as well as isospin asymmetric nuclear matter.",0601098v2
+2001-07-31,Properties of Elastic Waves in a non-Newtonian (Maxwell) Fluid-Saturated Porous Medium,"The present study investigates novelties brought about into the classic
+Biot's theory of propagation of elastic waves in a fluid-saturated porous solid
+by inclusion of non-Newtonian effects that are important, for example, for
+hydrocarbons. Based on our previous results (Tsiklauri and Beresnev: 2001,
+Phys. Rev. E, 63, 046304), we have investigated the propagation of rotational
+and dilatational elastic waves, through calculating their phase velocities and
+attenuation coefficients as a function of frequency. We found that the
+replacement of an ordinary Newtonian fluid by a Maxwell fluid in the
+fluid-saturated porous solid results in: (a) an overall increase of the phase
+velocities of both the rotational and dilatational waves. With the increase of
+frequency these quantities tend to a fixed, higher, as compared to the
+Newtonian limiting case, level which is not changing with the decrease of the
+Deborah number $\alpha$. (b) the overall decrease of the attenuation
+coefficients of both the rotational and dilatational waves. With the increase
+of frequency these quantities tend to a progressively lower, as compared to the
+Newtonian limiting case, levels as $\alpha$ decreases. (c) Appearance of
+oscillations in all physical quantities in the deeply non-Newtonian regime.",0107078v2
+2001-03-23,Entropy production and wave packet dynamics in the Fock space of closed chaotic many-body systems,"Highly excited many-particle states in quantum systems such as nuclei, atoms,
+quantum dots, spin systems, quantum computers etc., can be considered as
+``chaotic'' superpositions of mean-field basis states (Slater determinants,
+products of spin or qubit states). This is due to a very high level density of
+many-body states that are easily mixed by a residual interaction between
+particles (quasi-particles). For such systems, we have derived simple
+analytical expressions for the time dependence of energy width of wave packets,
+as well as for the entropy, number of principal basis components and inverse
+participation ratio, and tested them in numerical experiments. It is shown that
+the energy width $\Delta (t)$ increases linearly and very quickly saturates.
+The entropy of a system increases quadratically, $S(t) \sim t^2$ at small
+times, and after, can grow linearly, $S(t) \sim t$, before the saturation.
+Correspondingly, the number of principal components determined by the entropy,
+$N_{pc} \sim exp{(S(t))}$, or by the inverse participation ratio, increases
+exponentially fast before the saturation. These results are explained in terms
+of a cascade model which describes the flow of excitation in the Fock space of
+basis components. Finally, a striking phenomenon of damped oscillations in the
+Fock space at the transition to an equilibrium is discussed.",0103129v1
+2007-05-09,Energy dependence of jet transport parameter and parton saturation in quark-gluon plasma,"We study the evolution and saturation of the gluon distribution function in
+the quark-gluon plasma as probed by a propagating parton and its effect on the
+computation of jet quenching or transport parameter $\hat{q}$. For thermal
+partons, the saturation scale $Q^2_s$ is found to be proportional to the Debye
+screening mass $\mu_D^2$. For hard probes, evolution at small $x=Q^2_s/6ET$
+leads to jet energy dependence of $\hat{q}$. We study this dependence for both
+a conformal gauge theory in weak and strong coupling limit and for (pure gluon)
+QCD. The energy dependence can be used to extract the shear viscosity $\eta$ of
+the medium since $\eta$ can be related to the transport parameter for thermal
+partons in a transport description. We also derive upper bounds on the
+transport parameter for both energetic and thermal partons. The later leads to
+a lower bound on shear viscosity-to-entropy density ratio which is consistent
+with the conjectured lower bound $\eta/s\geq 1/4\pi$. We also discuss the
+implications on the study of jet quenching at the BNL Relativistic Heavy Ion
+Collider and the CERN Large Hadron Collider and the bulk properties of the
+dense matter.",0705.1352v4
+2007-10-27,Saturation Throughput Analysis of IEEE 802.11 in Presence of Non Ideal Transmission Channel and Capture Effects,"In this paper, we provide a saturation throughput analysis of the IEEE 802.11
+protocol at the data link layer by including the impact of both transmission
+channel and capture effects in Rayleigh fading environment. Impacts of both
+non-ideal channel and capture effects, specially in an environment of high
+interference, become important in terms of the actual observed throughput. As
+far as the 4-way handshaking mechanism is concerned, we extend the
+multi-dimensional Markovian state transition model characterizing the behavior
+at the MAC layer by including transmission states that account for packet
+transmission failures due to errors caused by propagation through the channel.
+This way, any channel model characterizing the physical transmission medium can
+be accommodated, including AWGN and fading channels. We also extend the Markov
+model in order to consider the behavior of the contention window when employing
+the basic 2-way handshaking mechanism.
+  Under the usual assumptions regarding the traffic generated per node and
+independence of packet collisions, we solve for the stationary probabilities of
+the Markov chain and develop expressions for the saturation throughput as a
+function of the number of terminals, packet sizes, raw channel error rates,
+capture probability, and other key system parameters. The theoretical
+derivations are then compared to simulation results confirming the
+effectiveness of the proposed models.",0710.5236v1
+2008-01-08,Studying Turbulence from Doppler-broadened Absorption Lines: Statistics of Logarithms of Intensity,"We continue our work on developing techniques for studying turbulence with
+spectroscopic data. We show that Doppler-broadened absorption spectral lines,
+in particularly, saturated absorption lines, can be used within the framework
+of the earlier-introduced technique termed the Velocity Coordinate spectrum
+(VCS). The VCS relates the statistics of fluctuations along the velocity
+coordinate to the statistics of turbulence, thus it does not require spatial
+coverage by sampling directions in the plane of the sky. We consider lines with
+different degree of absorption and show that for lines of optical depth less
+than one, our earlier treatment of the VCS developed for spectral emission
+lines is applicable, if the optical depth is used instead of intensity. This
+amounts to correlating the logarithms of absorbed intensities. For larger
+optical depths and saturated absorption lines, we show, that the amount of
+information that one can use is, inevitably, limited by noise. In practical
+terms, this means that only wings of the line are available for the analysis.
+In terms of the VCS formalism, this results in introducing an additional
+window, which size decreases with the increase of the optical depth. As a
+result, strongly saturated absorption lines carry the information only about
+the small scale turbulence. Nevertheless, the contrast of the fluctuations
+corresponding to the small scale turbulence increases with the increase of the
+optical depth, which provides advantages for studying turbulence combining
+lines with different optical depths. Combining different absorption lines one
+can tomography turbulence in the interstellar gas in all its complexity.",0801.1151v1
+2008-07-10,Nonequilibrium carriers in an intrinsic graphene under interband photoexcitation,"We study nonequilibrium carriers (electrons and holes) in an intrinsic
+graphene at low temperatures under far- and mid-infrared (IR) radiation in a
+wide range of its intensities. The energy distributions of carriers are
+calculated using a quasiclassic kinetic equation which accounts for the energy
+relaxation due to acoustic phonons and the radiative generation-recombination
+processes associated with thermal radiation and the carrier photoexcitation by
+incident radiation. It is found that the nonequilibrium distributions are
+determined by an interplay between weak energy relaxation on acoustic phonons
+and generation-recombination processes as well as by the effect of pumping
+saturation. Due to the effect of saturation, the carrier distribution functions
+can exhibit plateaus around the pumping region at elevated intensities. As
+shown, at sufficiently strong mid-IR pumping, the population inversion can
+occur below the pumping energy. The graphene dc conductivity as a function of
+the pumping intensity exhibits a pronounced nonlinearity with a sub-linear
+region at fairly low intensities and a saturation at a strong pumping. However,
+an increase in the pumping intensity in very wide range leads only to a modest
+increase in the carrier concentration and, particularly, the dc conductivity.
+The graphene conductivity at mid-IR irradiation exhibit strong sensitivity to
+mechanisms of carrier momentum relaxation.",0807.1590v1
+2008-12-23,"A probable vacuum state containing a large number of hydrogen atom of excited state or ground state K, Rb or Cs atom","The linear Stark effect shows that the first excited state of hydrogen atom
+has large permanent electric dipole moment (EDM), d(H)=3eao (ao is Bohr
+radius). Using special capacitors our experiments discovered that the ground
+state K, Rb or Cs atom is polar atom with a large EDM of the order of eao as
+hydrogen atom of excited state. Their capacitance(C) at different voltage (V)
+was measured. The C-V curve shows that the saturation polarization of K, Rb or
+Cs vapor has be observed when the field E more than ten to the fifth power V/m.
+When the saturation polarization appeared, nearly all K, Rb or Cs atoms(more
+than 98 percent) turned toward the direction of the field, and C is
+approximately equal to Co (Co is vacuum capacitance) or their dielectric
+constant is nearly the same as vacuum! K, Rb or Cs vapor just exist in the
+lowest energy state, so we see the vacuum state containing a large number of
+atoms! Due to the saturation polarization of hydrogen vapor of excited state is
+easily appears, we conjecture that a vacuum state containing a large number of
+hydrogen atom of excited state may exist at early Universe when the absolute
+temperature T is approximately equal to ten to the fifth power K.",0812.4424v1
+2009-05-04,A completeness result for a realisability semantics for an intersection type system,"In this paper we consider a type system with a universal type $\omega$ where
+any term (whether open or closed, $\beta$-normalising or not) has type
+$\omega$. We provide this type system with a realisability semantics where an
+atomic type is interpreted as the set of $\lambda$-terms saturated by a certain
+relation. The variation of the saturation relation gives a number of
+interpretations to each type. We show the soundness and completeness of our
+semantics and that for different notions of saturation (based on weak head
+reduction and normal $\beta$-reduction) we obtain the same interpretation for
+types. Since the presence of $\omega$ prevents typability and realisability
+from coinciding and creates extra difficulties in characterizing the
+interpretation of a type, we define a class ${\mathbb U}^+$ of the so-called
+positive types (where $\omega$ can only occur at specific positions). We show
+that if a term inhabits a positive type, then this term is $\beta$-normalisable
+and reduces to a closed term. In other words, positive types can be used to
+represent abstract data types. The completeness theorem for ${\mathbb U}^+$
+becomes interesting indeed since it establishes a perfect equivalence between
+typable terms and terms that inhabit a type. In other words, typability and
+realisability coincide on ${\mathbb U}^+$. We give a number of examples to
+explain the intuition behind the definition of ${\mathbb U}^+$ and to show that
+this class cannot be extended while keeping its desired properties.",0905.0354v1
+2009-05-04,Dark Energy from Large-Scale Structure Lensing Information,"Wide area Large-Scale Structure (LSS) surveys are planning to map a
+substantial fraction of the visible universe to quantify dark energy through
+Baryon Acoustic Oscillations (BAO). At increasing redshift, for example that
+probed by proposed 21-cm intensity mapping surveys, gravitational lensing
+potentially limits the fidelity (Hui et al., 2007) because it distorts the
+apparent matter distribution. In this paper we show that these distortions can
+be reconstructed, and actually used to map the distribution of intervening dark
+matter. The lensing information for sources at z=1-3 allows accurate
+reconstruction of the gravitational potential on large scales, l <~ 100, which
+is well matched for Integrated Sachs-Wolfe (ISW) effect measurements of dark
+energy and its sound speed, and a strong constraint for modified gravity models
+of dark energy.
+  We built an optimal quadratic lensing estimator for non-Gaussian sources,
+which is necessary for LSS. The phenomenon of ""information saturation"" (Rimes &
+Hamilton, 2005) saturates reconstruction at mildly non-linear scales, where the
+linear source power spectrum Delta^2 ~ 0.2-0.5. We find that steeper power
+spectra, saturate more quickly. We compute the effective number densities of
+independent lensing sources for LSS lensing, and find that they increase
+rapidly with redshifts. For LSS/21-cm sources at z ~ 2-4, the lensing
+reconstruction is limited by cosmic variance at l<~ 100.",0905.0499v1
+2009-11-11,Interference Mitigation Through Limited Receiver Cooperation,"Interference is a major issue limiting the performance in wireless networks.
+Cooperation among receivers can help mitigate interference by forming
+distributed MIMO systems. The rate at which receivers cooperate, however, is
+limited in most scenarios. How much interference can one bit of receiver
+cooperation mitigate? In this paper, we study the two-user Gaussian
+interference channel with conferencing decoders to answer this question in a
+simple setting. We identify two regions regarding the gain from receiver
+cooperation: linear and saturation regions. In the linear region receiver
+cooperation is efficient and provides a degrees-of-freedom gain, which is
+either one cooperation bit buys one more bit or two cooperation bits buy one
+more bit until saturation. In the saturation region receiver cooperation is
+inefficient and provides a power gain, which is at most a constant regardless
+of the rate at which receivers cooperate. The conclusion is drawn from the
+characterization of capacity region to within two bits. The proposed strategy
+consists of two parts: (1) the transmission scheme, where superposition
+encoding with a simple power split is employed, and (2) the cooperative
+protocol, where one receiver quantize-bin-and-forwards its received signal, and
+the other after receiving the side information decode-bin-and-forwards its
+received signal.",0911.2053v1
+2009-12-26,Complexity Analysis of Unsaturated Flow in Heterogeneous Media Using a Complex Network Approach,"In this study, we investigate the complexity of two-phase flow (air/water) in
+a heterogeneous soil sample by using complex network theory, where the supposed
+porous media is non-deformable media, under the time-dependent gas pressure.
+Based on the different similarity measurements (i.e., correlation, Euclidean
+metrics) over the emerged patterns from the evolution of saturation of
+non-wetting phase of a multi-heterogeneous soil sample, the emerged complex
+networks are recognized. Understanding of the properties of complex networks
+(such degree distribution, mean path length, clustering coefficient) can be
+supposed as a way to analysis of variation of saturation profiles structures
+(as the solution of finite element method on the coupled PDEs) where complexity
+is coming from the changeable connection and links between assumed nodes. Also,
+the path of evolution of the supposed system will be illustrated on the state
+space of networks either in correlation and Euclidean measurements. The results
+of analysis showed in a closed system the designed complex networks approach to
+small world network where the mean path length and clustering coefficient are
+low and high, respectively. As another result, the evolution of macro -states
+of system (such mean velocity of air or pressure) can be scaled with
+characteristics of structure complexity of saturation. In other part, we tried
+to find a phase transition criterion based on the variation of non-wetting
+phase velocity profiles over a network which had been constructed over
+correlation distance.",0912.4991v2
+2010-01-03,Nuclear limits on properties of pulsars and gravitational waves,"Pulsars are among the most mysterious astrophysical objects in the Universe
+and are believed to be rotating neutron stars formed in supernova explosions.
+They are unique testing grounds of dense matter theories and gravitational
+physics and also provide links among nuclear physics, particle physics and
+General Relativity. Neutron stars may exhibit some of the most extreme and
+exotic characteristics that could not be found elsewhere in the Universe. Their
+properties are largely determined by the equation of state (EOS) of
+neutron-rich matter, which is the chief ingredient in calculating neutron star
+structure and properties of related phenomena, such as gravitational wave
+emission from deformed pulsars. Presently, the EOS of neutron-rich matter is
+still very uncertain mainly due to the poorly known density dependence of the
+nuclear symmetry energy especially at supra-saturation densities. Nevertheless,
+significant progress has been made recently in constraining the density
+dependence of the nuclear symmetry energy mostly at sub-saturation densities
+using terrestrial nuclear reactions. While there are still some uncertainties
+especially at supra-saturation densities, these constraints could provide
+useful information on the limits of the global properties of pulsars and the
+gravitational waves to be expected from them. Here we review our recent work on
+constraining properties of pulsars and gravitational radiation with data from
+terrestrial nuclear laboratories.",1001.0353v1
+2010-04-08,Phase transition in saturated porous media: pore-fluid segregation in consolidation,"Consider the consolidation process typical of soils, this phenomenon is
+expected not to exhibit a unique state of equilibrium, depending on the
+\textit{external loading} and the constitutive parameters. Beyond the standard
+solution, also pore-fluid segregation, which is typically associated with
+fluidization of the granular material, can arise. Pore-fluid segregation has
+been recognized as a phenomenon typical of the short time behavior of a
+saturated porous slab or a saturated porous sphere, during consolidation. In
+both circumstances Biot's three dimensional model provides time increasing
+values of the water pressure (and fluid mass density) at the center of the slab
+(or of the sphere), at early times, if the Lam\'{e} constant $\mu$ of the
+skeleton is different from zero. This localized pore-fluid segregation is known
+in the literature as Mandel--Cryer effect. In this paper a non linear
+poromechanical model is formulated. The model is able to describe the
+occurrence of two states of equilibrium and the switching from one to the other
+by considering a kind of \textit{phase transition}. Extending classical Biot's
+theory a more than quadratic strain energy potential is postulated, depending
+on the strain of the porous material and the variation of the fluid mass
+density (measured with respect to the skeleton reference volume). When the
+consolidating pressure is strong enough the existence of two distinct minima is
+proven.",1004.1310v1
+2010-10-13,Revisiting the thermodynamics of hardening plasticity for unsaturated soils,"A thermodynamically consistent extension of the constitutive equations of
+saturated soils to unsaturated conditions is often worked out through the use a
+unique 'effective' interstitial pressure, accounting equivalently for the
+pressures of the saturating fluids acting separately on the internal solid
+walls of the pore network. The natural candidate for this effective
+interstitial pressure is the space averaged interstitial pressure. In contrast
+experimental observations have revealed that, at least, a pair of stress state
+variables was needed for a suitable framework to describe
+stress-strain-strength behaviour of unsaturated soils. The thermodynamics
+analysis presented here shows that the most general approach to the behaviour
+of unsaturated soils actually requires three stress state variables: the
+suction, which is required to describe the invasion of the soil by the liquid
+water phase through the retention curve; two effective stresses, which are
+required to describe the soil deformation at water saturation held constant.
+However a simple assumption related to the plastic flow rule leads to the final
+need of only a Bishop-like effective stress to formulate the stress-strain
+constitutive equation describing the soil deformation, while the retention
+properties still involve the suction and possibly the deformation. Commonly
+accepted models for unsaturated soils, that is the Barcelona Basic Model and
+any approach based on the use of an effective averaged interstitial pressure,
+appear as special extreme cases of the thermodynamic formulation proposed here.",1010.2598v1
+2010-10-13,Is the degree of saturation a good candidate for Bishop's X parameter?,"In unsaturated soil mechanics, the quest for an effective stress playing the
+same role as Terzaghi's effective stress does for saturated soils has
+introduced a long standing debate, dating back to the 1960s. Several
+contributions have been proposed since the early work of Bishop. It is well
+recognized to date that a single constitutive stress is not sufficient by
+itself to catch the main features of the behaviour of unsaturated soils and it
+is often combined with matric suction. In this paper, focus is given to a
+largely used formulation for such a constitutive stress, based on the use of an
+averaged pore pressure. In particular, this paper discusses on thermodynamics
+bases the validity of the choice of the factor X weighting the fluid pressures
+contribution to the constitutive stress. This factor is usually assumed to be
+equal to the degree of saturation of water. In this work it is shown that the
+choice of this natural candidate implies restrictive assumptions on the plastic
+flow rule. As shown from experimental data obtained from a literature review,
+this choice may not be pertinent for certain classes of materials, particularly
+high plasticity clays.",1010.2608v1
+2010-12-29,Barrier Lowering and Backscattering Extraction in Short-Channel MOSFETs,"In this work we propose a fully experimental method to extract the barrier
+lowering in short-channel saturated MOSFETs using the Lundstrom backscattering
+transport model in a one sub-band approximation and carrier degeneracy. The
+knowledge of the barrier lowering at the operative bias point in the inversion
+regime is of fundamental importance in device scaling. At the same time we
+obtain also an estimate of the backscattering ratio and of the saturation
+inversion charge. Respect to previously reported works on extraction of
+transport parameters based on the Lundstrom model, our extraction method is
+fully consistent with it, whereas other methods make a number of approximations
+in the calculation of the saturation inversion charge which are inconsistent
+with the model. The proposed experimental extraction method has been validated
+and applied to results from device simulation and measurements on short-channel
+poly-Si/SiON gate nMOSFETs with gate length down to 70 nm. Moreover we propose
+an extension of the backscattering model to the case of 2D geometries (e.g.
+bulk MOSFETs). We found that, in this case, the backscattering is governed by
+the carrier transport in a few nanometers close to the silicon/oxide interface
+and that the value of the backscattering ratio obtained with a 1D approach can
+be significantly different from the real 2D value.",1012.5978v1
+2011-05-04,Homogeneity tests for Michaelis-Menten curves with application to fluorescence resonance energy transfer data,"Resonance energy transfer methods are in wide use for evaluating
+protein-protein interactions and protein conformational changes in living
+cells. Fluorescence resonance energy transfer (FRET) measures energy transfer
+as a function of the acceptor:donor ratio, generating FRET saturation curves.
+Modeling these curves by Michaelis-Menten kinetics allows characterization by
+two parameters, which serve to evaluate apparent affinity between two proteins
+and to compare this affinity in different experimental conditions. To reduce
+the effect of sampling variability, several statistical samples of the
+saturation curve are generated in the same biological conditions. Here we study
+three procedures to determine whether statistical samples in a collection are
+homogeneous, in the sense that they are extracted from the same regression
+model. From the hypothesis testing viewpoint, we considered an F test and a
+procedure based on bootstrap resampling. The third method analyzed the problem
+from the model selection viewpoint, and used the Akaike information criterion
+(AIC). Although we only considered the Michaelis-Menten model, all statistical
+procedures would be applicable to any other nonlinear regression model. We
+compared the performance of the homogeneity testing methods in a Monte Carlo
+study and through analysis in living cells of FRET saturation curves for
+dimeric complexes of CXCR4, a seven-transmembrane receptor of the G
+protein-coupled receptor family. We show that the F test, the bootstrap
+procedure and the model selection method lead in general to similar
+conclusions, although AIC gave the best results when sample sizes were small,
+whereas the F test and the bootstrap method were more appropriate for large
+samples. In practice, all three methods are easy to use simultaneously and show
+consistency, facilitating conclusions on sample homogeneity.",1105.0780v1
+2011-05-12,Approximation by Semigroups of Spherical Operators,"This paper discusses the approximation by %semigroups of operators of class
+($\mathscr{C}_0$) on the sphere and focuses on a class of so called
+exponential-type multiplier operators. It is proved that such operators form a
+strongly continuous semigroup of contraction operators of class
+($\mathscr{C}_0$), from which the equivalence between approximation for these
+operators and $K$-functionals introduced by the operators is given. As
+examples, the constructed $r$-th Boolean of generalized spherical Abel-Poisson
+operator and $r$-th Boolean of generalized spherical Weierstrass operator
+denoted by $\oplus^r V_t^{\gamma}$ and $\oplus^r W_t^{\kappa}$ separately ($r$
+is any positive integer, $0<\gamma,\kappa\leq1$ and $t>0$) satisfy that
+  $\|\oplus^r V_t^{\gamma}f - f\|_{\mathcal{X}}\approx
+\omega^{r\gamma}(f,t^{1/\gamma})_{\mathcal{X}}$ and $\|\oplus^r W_t^{\kappa}f -
+f\|_{\mathcal{X}}\approx \omega^{2r\gamma}(f,t^{1/(2\kappa)})_{\mathcal{X}}$,
+for all $f\in \mathcal{X}$, where $\mathcal{X}$ is a Banach space of continuous
+functions or $\mathcal{L}^p$-integrable functions ($1\leq p<\infty$) and
+$\|\cdot\|_{\mathcal{X}}$ is the norm on $\mathcal{X}$ and
+$\omega^s(f,t)_{\mathcal{X}}$ is the moduli of smoothness of degree $s>0$ for
+$f\in \mathcal{X}$. The saturation order and saturation class of the regular
+exponential-type multiplier operators with positive kernels are also obtained.
+Moreover, it is proved that $\oplus^r V_t^{\gamma}$ and $\oplus^r W_t^{\kappa}$
+have the same saturation class if $\gamma=2\kappa$.",1105.2393v1
+2011-05-19,On Spectrum of kappa-Resplendent Models,"We prove that some natural ""outside"" property is equivalent (for a first
+order class) to being stable.
+  For a model, being resplendent is a strengthening of being kappa-saturated.
+Restricting ourselves to the case kappa > |T| for transparency, a model M is
+kappa-resplendent means: when we expand M by <kappa individual constants (c_i:i
+< alpha), if (M, c_i)_ {i<alpha} has an elementary extension expandable to be a
+model of T' where Th((M,c_i)_{i<alpha}) subseteq T', |T'| < kappa then already
+(M,c_i)_{i<\alpha} can be expanded to a model of T'.
+  Trivially any saturated model of cardinality lambda is lambda-resplendent. We
+ask: how may kappa-resplendent models of a (first order complete) theory T of
+cardinality lambda are there? Naturally we restrict ourselves to cardinals
+lambda=lambda^ kappa + 2^ {|T|}. Then we get a complete and satisfying answer:
+this depends just on T being stable or unstable. In this case proving that for
+stable T we get few, is not hard; in fact every resplendent model of T is
+saturated hence determined by its cardinality up to isomorphism. The inverse is
+more problematic because naturally we have to use Skolem functions with any
+alpha<kappa places. Normally we use relevant partition theorems (Ramsey theorem
+or Erd\H{o}s-Rado theorem), but in our case the relevant partitions theorems
+fails so we have to be careful.",1105.3774v2
+2011-07-16,Spatially-Coupled Codes and Threshold Saturation on Intersymbol-Interference Channels,"Recently, it has been observed that terminated low-density-parity-check
+(LDPC) convolutional codes (or spatially-coupled codes) appear to approach
+capacity universally across the class of binary memoryless channels. This is
+facilitated by the ""threshold saturation"" effect whereby the belief-propagation
+(BP) threshold of the spatially-coupled ensemble is boosted to the maximum
+a-posteriori (MAP) threshold of the underlying constituent ensemble.
+  In this paper, we consider the universality of spatially-coupled codes over
+intersymbol-interference (ISI) channels under joint iterative decoding. More
+specifically, we empirically show that threshold saturation also occurs for the
+considered problem. This can be observed by first identifying the EXIT curve
+for erasure noise and the GEXIT curve for general noise that naturally obey the
+general area theorem. From these curves, the corresponding MAP and the BP
+thresholds are then numerically obtained. With the fact that regular LDPC codes
+can achieve the symmetric information rate (SIR) under MAP decoding,
+spatially-coupled codes with joint iterative decoding can universally approach
+the SIR of ISI channels. For the dicode erasure channel, Kudekar and Kasai
+recently reported very similar results based on EXIT-like curves.",1107.3253v2
+2011-12-20,Finding D-optimal designs by randomised decomposition and switching,"The Hadamard maximal determinant (maxdet) problem is to find the maximum
+determinant D(n) of a square {+1, -1} matrix of given order n. Such a matrix
+with maximum determinant is called a saturated D-optimal design. We consider
+some cases where n > 2 is not divisible by 4, so the Hadamard bound is not
+attainable, but bounds due to Barba or Ehlich and Wojtas may be attainable. If
+R is a matrix with maximal (or conjectured maximal) determinant, then G = RR^T
+is the corresponding Gram matrix. For the cases that we consider, maximal or
+conjectured maximal Gram matrices are known. We show how to generate many
+Hadamard equivalence classes of solutions from a given Gram matrix G, using a
+randomised decomposition algorithm and row/column switching. In particular, we
+consider orders 26, 27 and 33, and obtain new saturated D-optimal designs (for
+order 26) and new conjectured saturated D-optimal designs (for orders 27 and
+33).",1112.4671v5
+2012-02-26,Dependent dreams: recounting types,"We investigate the class of models of a general dependent theory. We continue
+math.LO/0702292 in particular investigating so called ""decomposition of types"";
+thesis is that what holds for stable theory and for Th(Q,<) hold for dependent
+theories. Another way to say this is: we have to look at small enough
+neighborhood and use reasonably definable types to analyze a type. We note the
+results understable without reading. First, a parallel to the ""stability
+spectrum"", the ""recounting of types"", that is assume lambda = lambda^{< lambda}
+is large enough, M a saturated model of T of cardinality lambda, let bold
+S_{aut}(M) be the number of complete types over M up to being conjugate, i.e.
+we identify p,q when some automorphism of M maps p to q . Whereas for
+independent T the number is 2^lambda, for dependent T the number is <= lambda
+moreover it is <= | alpha |^{|T|} when lambda = aleph_alpha. Second, for stable
+theories ""lots of indiscernibility exists"" a ""too good indiscernible existence
+theorem"" saying, e.g. that if the type tp (d_beta ; {d_beta : beta < alpha}) is
+increasing for alpha < kappa = cf(kappa) and kappa > 2^{|T|} then <d_alpha :
+alpha in S> is indiscernible for some stationary S subseteq kappa. Third, for
+stable T,a model is kappa-saturated iff it is aleph_epsilon-saturated and every
+infinite indiscernible set (of elements) of cardinality < kappa can be
+increased. We prove here an analog. Fourth, for p in S(M), the number of
+ultrafilters on the outside definable subsets of M extending p has an absolute
+bound 2^{|T|} . Restricting ourselves to one phi(x, y), the number is finite,
+with an absolute found (well depending on T and phi).",1202.5795v1
+2012-04-25,A Simple Proof of Threshold Saturation for Coupled Scalar Recursions,"Low-density parity-check (LDPC) convolutional codes (or spatially-coupled
+codes) have been shown to approach capacity on the binary erasure channel (BEC)
+and binary-input memoryless symmetric channels. The mechanism behind this
+spectacular performance is the threshold saturation phenomenon, which is
+characterized by the belief-propagation threshold of the spatially-coupled
+ensemble increasing to an intrinsic noise threshold defined by the uncoupled
+system.
+  In this paper, we present a simple proof of threshold saturation that applies
+to a broad class of coupled scalar recursions. The conditions of the theorem
+are verified for the density-evolution (DE) equations of irregular LDPC codes
+on the BEC, a class of generalized LDPC codes, and the joint iterative decoding
+of LDPC codes on intersymbol-interference channels with erasure noise. Our
+approach is based on potential functions and was motivated mainly by the ideas
+of Takeuchi et al. The resulting proof is surprisingly simple when compared to
+previous methods.",1204.5703v3
+2012-07-02,Moist turbulent Rayleigh-Benard convection with Neumann and Dirichlet boundary conditions,"Turbulent Rayleigh-Benard convection with phase changes in an extended layer
+between two parallel impermeable planes is studied by means of
+three-dimensional direct numerical simulations for Rayleigh numbers between
+10^4 and 1.5\times 10^7 and for Prandtl number Pr=0.7. Two different sets of
+boundary conditions of temperature and total water content are compared:
+imposed constant amplitudes which translate into Dirichlet boundary conditions
+for the scalar field fluctuations about the quiescent diffusive equilibrium and
+constant imposed flux boundary conditions that result in Neumann boundary
+conditions. Moist turbulent convection is in the conditionally unstable regime
+throughout this study for which unsaturated air parcels are stably and
+saturated air parcels unstably stratified. A direct comparison of both sets of
+boundary conditions with the same parameters requires to start the turbulence
+simulations out of differently saturated equilibrium states. Similar to dry
+Rayleigh-Benard convection the differences in the turbulent velocity
+fluctuations, the cloud cover and the convective buoyancy flux decrease across
+the layer with increasing Rayleigh number. At the highest Rayleigh numbers the
+system is found in a two-layer regime, a dry cloudless and stably stratified
+layer with low turbulence level below a fully saturated and cloudy turbulent
+one which equals classical Rayleigh-Benard convection layer. Both are separated
+by a strong inversion that gets increasingly narrower for growing Rayleigh
+number.",1207.0420v1
+2012-09-27,Derivation of soil-specific streaming potential electrical parameters from hydrodynamic characteristics of partially saturated soils,"Water movement in unsaturated soils gives rise to measurable electrical
+potential differences that are related to the flow direction and volumetric
+fluxes, as well as to the soil properties themselves. Laboratory and field data
+suggest that these so-called streaming potentials may be several orders of
+magnitudes larger than theoretical predictions that only consider the influence
+of the relative permeability and electrical conductivity on the self potential
+(SP) data. Recent work has partly improved predictions by considering how the
+volumetric excess charge in the pore space scales with the inverse of water
+saturation. We present a new theoretical approach that uses the flux-averaged
+excess charge, not the volumetric excess charge, to predict streaming
+potentials. We present relationships for how this effective excess charge
+varies with water saturation for typical soil properties using either the water
+retention or the relative permeability function. We find large differences
+between soil types and the predictions based on the relative permeability
+function display the best agreement with field data. The new relationships
+better explain laboratory data than previous work and allow us to predict the
+recorded magnitudes of the streaming potentials following a rainfall event in
+sandy loam, whereas previous models predict three orders of magnitude too small
+values. We suggest that the strong signals in unsaturated media can be used to
+gain information about fluxes (including very small ones related to film flow),
+but also to constrain the relative permeability function, the water retention
+curve, and the relative electrical conductivity function.",1209.6335v1
+2013-01-25,A Proof of Threshold Saturation for Spatially-Coupled LDPC Codes on BMS Channels,"Low-density parity-check (LDPC) convolutional codes have been shown to
+exhibit excellent performance under low-complexity belief-propagation decoding
+[1], [2]. This phenomenon is now termed threshold saturation via spatial
+coupling. The underlying principle behind this appears to be very general and
+spatially-coupled (SC) codes have been successfully applied in numerous areas.
+Recently, SC regular LDPC codes have been proven to achieve capacity
+universally, over the class of binary memoryless symmetric (BMS) channels,
+under belief-propagation decoding [3], [4].
+  In [5], [6], potential functions are used to prove that the BP threshold of
+SC irregular LDPC ensembles saturates, for the binary erasure channel, to the
+conjectured MAP threshold (known as the Maxwell threshold) of the underlying
+irregular ensembles. In this paper, that proof technique is generalized to BMS
+channels, thereby extending some results of [4] to irregular LDPC ensembles. We
+also believe that this approach can be expanded to cover a wide class of
+graphical models whose message-passing rules are associated with a Bethe free
+energy.",1301.6111v2
+2013-02-07,"Saturation effects in exclusive rhoT, rhoL meson electroproduction","We use recent results for the gamma*L -> rhoL and gamma*T -> rhoT impact
+factors, computed in the impact parameter representation within the collinear
+factorization scheme, to get predictions for the polarized cross-sections
+sigmaT and sigmaL of the diffractive leptoproduction of the rho meson at high
+energy. In this approach the helicity amplitude is a convolution of the
+scattering amplitude of a color dipole with a target, together with the virtual
+gamma wave function and with the first moments of the rho meson wave function
+(in the transverse momentum space), given by the distribution amplitudes up to
+twist 3 for the gamma*T -> rhoT impact factor and up to twist 2 for the gamma*L
+-> rhoL impact factor. Combining these results with recent dipole models fitted
+to DIS data, which include saturation effects, we show that the predictions are
+in good agreement with HERA data for photon virtuality (Q**2) larger than
+typically 5 GeV**2, without free parameters and with a weak dependence on the
+choice of the factorization scale, i.e. the shape of the DAs, for both
+longitudinally and transversely polarized rho meson. For lower values of Q**2,
+the inclusion of saturation effects is not enough to provide a good description
+of HERA data. We believe that it is a signal of a need for higher twist
+contributions in the rho meson DAs. We also analyze the radial distributions of
+dipoles between the initial gamma* and the final rho meson states.",1302.1766v1
+2013-09-29,Resolving the Puzzle of the Pion-Photon Transition Form Factor,"We investigate the form factors for pseudoscalar-meson-photon transitions by
+means of dispersive QCD sum rules and demonstrate that most of the measurements
+done so far (in particular, those by BaBar for $\eta,$ $\eta',$ and $\eta_c$
+and those by Belle for $\pi^0$) are, on the one hand, compatible with each
+other and with the saturation required by factorization theorems obtained from
+perturbative QCD and, on the other hand, give a hint that saturation is
+effective already at relatively low momentum transfers $Q^2;$ this hypothesis
+is supported by experimental data for the charged-pion elastic form factor
+available in the range $Q^2\approx2-4\;\{GeV}^2.$ The only exception are the
+BaBar results for the $\pi^0\gamma$ transition form factor, which do not fit
+into such picture. We point out that results expected from SHMS at JLab on the
+pion elastic form factor in the region $Q^2\approx5-8\;\{GeV}^2$ will provide
+the ultimate test of saturation and factorization and strongly impact our
+general view of the form factors up to infinitely large $Q^2.$",1309.7605v2
+2013-10-10,Instability of Evaporation Fronts in the Interstellar Medium,"The neutral component of the interstellar medium is segregated into the cold
+neutral medium (CNM) and warm neutral medium (WNM) as a result of thermal
+instability. It was found that a plane-parallel CNM-WNM evaporation interface,
+across which the CNM undergoes thermal expansion, is linearly unstable to
+corrugational disturbances, in complete analogy with the Darrieus-Landau
+instability (DLI) of terrestrial flames. We perform a full linear stability
+analysis as well as nonlinear hydrodynamic simulations of the DLI of such
+evaporation fronts in the presence of thermal conduction. We find that the DLI
+is suppressed at short length scales by conduction. The length and time scales
+of the fastest growing mode are inversely proportional to the evaporation flow
+speed of the CNM and its square, respectively. In the nonlinear stage, the DLI
+saturates to a steady state where the front deforms to a finger-like shape
+protruding toward the WNM, without generating turbulence. The evaporation rate
+at nonlinear saturation is larger than the initial plane-parallel value by a
+factor of 2.4 when the equilibrium thermal pressure is 1800 k_B cm^-3 K. The
+degrees of front deformation and evaporation-rate enhancement at nonlinear
+saturation are determined primarily by the density ratio between the CNM and
+WNM. We demonstrate that the Field length in the thermally unstable medium
+should be resolved by at least four grid points to obtain reliable numerical
+outcomes involving thermal instability.",1310.2940v2
+2013-10-16,Effect of saccades in tongue electrotactile stimulation for vision substitution applications,"The visual substitution paradigm aims to facilitate the life of blind people.
+Generally one uses electro-stimulating devices where electrodes are arranged
+into arrays to stimulate the skin or the tongue mucosa to send signals of
+visual type to the subjects. When an electro-stimulation signal is applied
+continuously (e.g. when static visual scenes are displayed for a long period of
+time), the receptors of the affected region can get saturated and the patient
+may lose the displayed information. We propose here some mechanisms that
+ameliorate the quality of perception of the electro-stimulation information.
+The electrical signal is encoded as 2D scenes projected onto the tongue via a
+Tongue Display Unit, i.e. an electro-tactile stimulator formed by a 12x12
+matrix of electrodes. We propose to apply stochastic saccades on this signal.
+Our assumption is that this eye-inspired mechanism should make the visual
+substitution more efficient (by improving the perception) because of the
+reduction of the tactile receptors saturation. The influence of saccades was
+evaluated by a series of experiments. Results revealed a benefit on the
+persistence of perception due to saccades. This work helps to prevent the
+saturation of receptors on the tongue. Therefore increasing the quality of
+vision by the way of the electro-stimulation. It allows new enhancement
+features to retinal prosthesis devices which suffer from the same phenomenon.",1310.4480v1
+2013-10-22,Electron sampling depth and saturation effects in perovskite films investigated by soft x-ray absorption spectroscopy,"Knowledge of the electron sampling depth and related saturation effects is
+important for quantitative analysis of X-ray absorption spectroscopy data, yet
+for oxides with the perovskite structure no quantitative values are so far
+available. Here we study absorption saturation in films of two of the
+most-studied perovskites, LCMO and YBCO, at the L2,3 edge of Mn and Cu,
+respectively. By measuring the electron-yield intensity as a function of photon
+incidence angle and film thickness, the sampling depth d, photon attenuation
+length, lambda, and the ratio lambda/d have been independently determined
+between 50 and 300 K. The extracted sampling depth dLCMO=3 nm for LCMO at high
+temperatures in its polaronic insulator state (150-300K) is not much larger
+than values reported for pure transition metals (d Co or Ni=2-2.5nm) at room
+temperature, but it is smaller than dYBCO=3.9 nm for metallic YBCO that is in
+turn smaller than the value reported for Fe3O4 (d=4.5 nm) The measured dLCMO
+increases to 4.5 nm when LCMO is in the metallic state at low temperatures.
+These results indicate that a universal rule of thumb for the sampling depth in
+oxides cannot be assumed, and that it can be measurably influenced by
+electronic phase transitions that derive from strong correlations.",1310.5998v1
+2013-11-08,Threshold Saturation for Nonbinary SC-LDPC Codes on the Binary Erasure Channel,"We analyze the asymptotic performance of nonbinary spatially-coupled
+low-density parity-check (SC-LDPC) code ensembles defined over the general
+linear group on the binary erasure channel. In particular, we prove threshold
+saturation of belief propagation decoding to the so called potential threshold,
+using the proof technique based on potential functions introduced by Yedla
+\textit{et al.}, assuming that the potential function exists. We rewrite the
+density evolution of nonbinary SC-LDPC codes in an equivalent vector recursion
+form which is suited for the use of the potential function. We then discuss the
+existence of the potential function for the general case of vector recursions
+defined by multivariate polynomials, and give a method to construct it. We
+define a potential function in a slightly more general form than one by Yedla
+\textit{et al.}, in order to make the technique based on potential functions
+applicable to the case of nonbinary LDPC codes. We show that the potential
+function exists if a solution to a carefully designed system of linear
+equations exists. Furthermore, we show numerically the existence of a solution
+to the system of linear equations for a large number of nonbinary LDPC code
+ensembles, which allows us to define their potential function and thus prove
+threshold saturation.",1311.2003v4
+2013-11-18,A Numerical Study of Methods for Moist Atmospheric Flows: Compressible Equations,"We investigate two common numerical techniques for integrating reversible
+moist processes in atmospheric flows in the context of solving the fully
+compressible Euler equations. The first is a one-step, coupled technique based
+on using appropriate invariant variables such that terms resulting from phase
+change are eliminated in the governing equations. In the second approach, which
+is a two-step scheme, separate transport equations for liquid water and vapor
+water are used, and no conversion between water vapor and liquid water is
+allowed in the first step, while in the second step a saturation adjustment
+procedure is performed that correctly allocates the water into its two phases
+based on the Clausius-Clapeyron formula. The numerical techniques we describe
+are first validated by comparing to a well-established benchmark problem.
+Particular attention is then paid to the effect of changing the time scale at
+which the moist variables are adjusted to the saturation requirements in two
+different variations of the two-step scheme. This study is motivated by the
+fact that when acoustic modes are integrated separately in time (neglecting
+phase change related phenomena), or when sound-proof equations are integrated,
+the time scale for imposing saturation adjustment is typically much larger than
+the numerical one related to the acoustics.",1311.4265v4
+2013-12-30,Deviations from Matthiessen rule and resistivity saturation effects in Gd and Fe,"According to earlier first-principles calculations, the spin-disorder
+contribution to the resistivity of rare-earth metals in the paramagnetic state
+is strongly underestimated if Matthiessen's rule is assumed to hold. To
+understand this discrepancy, the resistivity of paramagnetic Fe and Gd is
+evaluated by taking into account both spin and phonon disorder. Calculations
+are performed using the supercell approach within the linear muffin-tin orbital
+method. Phonon disorder is modeled by introducing random displacements of the
+atomic nuclei, and the results are compared with the case of fictitious
+Anderson disorder. In both cases the resistivity shows a nonlinear dependence
+on the square of the disorder potential, which is interpreted as a resistivity
+saturation effect. This effect is much stronger in Gd than in Fe. The
+non-linearity makes the phonon and spin-disorder contributions to the
+resistivity non-additive, and the standard procedure of extracting the
+spin-disorder resistivity by extrapolation from high temperatures becomes
+ambiguous. An ""apparent"" spin-disorder resistivity obtained through such
+extrapolation is in much better agreement with experiment compared to the
+results obtained by considering only spin disorder. By analyzing the spectral
+function of the paramagnetic Gd in the presence of Anderson disorder, the
+resistivity saturation is explained by the collapse of a large area of the
+Fermi surface due to the disorder-induced mixing between the electronic and
+hole sheets.",1312.7802v1
+2014-03-27,Stability of metal-rich very massive stars,"We revisit the stability of very massive nonrotating main-sequence stars at
+solar metallicity, with the goal of understanding whether radial pulsations set
+a physical upper limit to stellar mass. Models of up to 938 solar masses are
+constructed with the Mesa code, and their linear stability in the fundamental
+mode, assumed to be the most dangerous, is analysed with a fully nonadiabatic
+method. Models above 100 MSun have extended tenuous atmospheres (""shelves"")
+that affect the stability of the fundamental. Even when positive, this growth
+rate is small, in agreement with previous results. We argue that small growth
+rates lead to saturation at small amplitudes that are not dangerous to the
+star. A mechanism for saturation is demonstrated involving nonlinear parametric
+coupling to short-wavelength g modes and the damping of the latter by radiative
+diffusion. The shelves are subject to much more rapidly growing strange modes.
+This also agrees with previous results but is extended here to higher masses.
+The strange modes probably saturate via shocks rather than mode coupling but
+have very small amplitudes in the core, where almost all of the stellar mass
+resides. Although our stellar models are hydrostatic, the structure of their
+outer parts suggests that optically thick winds, driven by some combination of
+radiation pressure, transsonic convection, and strange modes, are more likely
+than pulsation in the fundamental mode to limit the main-sequence lifetime.",1403.7241v2
+2014-04-11,Interference Allocation Scheduler for Green Multimedia Delivery,"One of the key challenges in wireless networking is how to allocate the
+available radio resources in order to maximise key service delivery parameters
+such as the aggregate throughput and the multimedia quality of experience
+(QoE). We propose a novel and effective scheduling policy that allocates
+resource blocks, such that interference power is shifted towards
+capacity-saturated users, while improving the throughput of unsaturated users.
+The highlight of the research is that the proposed scheme can dramatically
+improve the performance of cells that have a high discrepancy in its
+signal-to-noise-ratio (SNR) distribution, which is typical in urban areas. The
+results show that a \emph{free-lunch} solution is possible, whereby for a
+negligible performance degradation in the saturated users, a large improvement
+in the non-saturated users can be obtained. However, on average, the number of
+free-lunch user pairings are low. By relaxing the degradation constraints, the
+\emph{non-free-lunch} solution can yield a greater multi-user throughput gain.
+Motivated by surge in mobile multimedia traffic, we further demonstrate that
+the proposed scheduling may have a profound impact on both energy efficiency
+and QoE of multimedia service delivery.",1404.3111v1
+2014-07-22,b-CGC versus IP-Sat and high precision combined HERA data,"The Impact-Parameter dependent Color Glass Condensate (b-CGC) and Saturation
+(IP-Sat) dipole models incorporate key features of small-x physics properties
+and match smoothly to the perturbative QCD regime at large $Q^2$ for a given
+$x$. Although both models include saturation effects and depend on
+impact-parameter, the former is based on the non-linear BK equation, while the
+latter is based on DGLAP evolution. After confronting the models to the
+recently released high precision combined HERA data, we show that in both
+models, the typical impact-parameter probed in the total $\gamma^{*}p$
+cross-section is about $b\approx 2\div 3\,\text{GeV}^{-1}$ and the proton
+saturation scale is $Q_S<1$ GeV in HERA kinematics. We show that most features
+of inclusive DIS and exclusive diffractive data at HERA are correctly
+reproduced in both models. Nevertheless, the b-CGC and the IP-Sat models give
+significantly different predictions beyond the current HERA kinematics for the
+structure functions at very low x and high virtualities $Q^2$, and for the
+exclusive diffractive vector meson and DVCS production at high $t$.",1407.5956v2
+2014-09-12,Extended linear regime of cavity-QED enhanced optical circular birefringence induced by a charged quantum dot,"Giant optical Faraday rotation (GFR) and giant optical circular birefringence
+(GCB) induced by a single quantum-dot spin in an optical microcavity can be
+regarded as linear effects in the weak-excitation approximation if the input
+field lies in the low-power limit [Hu et al, Phys.Rev. B {\bf 78}, 085307(2008)
+and ibid {\bf 80}, 205326(2009)]. In this work, we investigate the transition
+from the weak-excitation approximation moving into the saturation regime
+comparing a semiclassical approximation with the numerical results from a
+quantum optics toolbox [S.M. Tan, J. Opt. B {\bf 1}, 424 (1999)]. We find that
+the GFR and GCB around the cavity resonance in the strong coupling regime are
+input-field independent at intermediate powers and can be well described by the
+semiclassical approximation. Those associated with the dressed state resonances
+in the strong coupling regime or merging with the cavity resonance in the
+Purcell regime are sensitive to input field at intermediate powers, and cannot
+be well described by the semiclassical approximation due to the quantum dot
+saturation. As the GFR and GCB around the cavity resonance are relatively
+immune to the saturation effects, the rapid read out of single electron spins
+can be carried out with coherent state and other statistically fluctuating
+light fields. This also shows that high speed quantum entangling gates, robust
+against input power variations, can be built exploiting these linear effects.",1409.3787v2
+2014-09-15,Tighter quantum uncertainty relations follow from a general probabilistic bound,"Uncertainty relations (URs) like the Heisenberg-Robertson or the time-energy
+UR are often considered to be hallmarks of quantum theory. Here, a simple
+derivation of these URs is presented based on a single classical inequality
+from estimation theory, a Cram\'er-Rao-like bound. The Heisenberg-Robertson UR
+is then obtained by using the Born rule and the Schr\""odinger equation. This
+allows a clear separtion of the probabilistic nature of quantum mechanics from
+the Hilbert space structure and the dynamical law. It also simplifies the
+interpretation of the bound. In addition, the Heisenberg-Robertson UR is
+tightened for mixed states by replacing one variance by the so-called quantum
+Fisher information. Thermal states of Hamiltonians with evenly-gapped energy
+levels are shown to saturate the tighter bound for natural choices of the
+operators. This example is further extended to Gaussian states of a harmonic
+oscillator. For many-qubit systems, we illustrate the interplay between
+entanglement and the structure of the operators that saturate the UR with
+spin-squeezed states and Dicke states.",1409.4440v3
+2014-09-22,Triple- and Quadruple-Gluon Azimuthal Correlations from Glasma and Higher-Dimensional Ridges,"We calculate the triple- and quadruple-gluon inclusive distributions with
+arbitrary rapidity and azimuthal angle dependences in the gluon saturation
+regime by using glasma diagrams. Also, we predict higher-dimensional ridges in
+triple- and quadruple-hadron correlations for p-p and p-Pb collisions at LHC,
+which have yet to be measured. In p-p and p-Pb collisions at the top LHC
+energies, gluon saturation is expected to occur since smaller Bjorken-$x$
+values are being probed. Glasma diagrams, which are enhanced at small-$x$,
+include the gluon saturation effects, and they are used for calculating the
+long-range rapidity correlations (""ridges"") and $v_n$ moments of the azimuthal
+distribution of detected hadrons. The glasma description reproduces the
+systematics of the data on both p-p and p-Pb ridges. As an alternative,
+relativistic hydrodynamics has also been applied to these small systems quite
+successfully. With the triple- and quadruple-gluon azimuthal correlations, this
+work aims to set the stage by going beyond the double-gluon azimuthal
+correlations in order to settle unambiguously the origin of ""collectivity"" in
+p-p and p-Pb collisions. We derive the triple- and quadruple-gluon azimuthal
+correlation functions in terms of unintegrated gluon distributions at arbitrary
+rapidities and azimuthal angles of the produced gluons. Then, unintegrated
+gluon distributions from the running coupling Balitsky-Kovchegov evolution
+equation are used to calculate the triple- and quadruple-gluon correlations for
+various parameters of gluon momenta, initial scale for small-$x$ evolution and
+beam energy.",1409.6347v2
+2014-10-07,"Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements and Crazing","Large-scale molecular simulations are performed to investigate tensile
+failure of polymer interfaces as a function of welding time $t$. Changes in the
+tensile stress, mode of failure and interfacial fracture energy $G_I$ are
+correlated to changes in the interfacial entanglements as determined from
+Primitive Path Analysis. Bulk polymers fail through craze formation, followed
+by craze breakdown through chain scission. At small $t$ welded interfaces are
+not strong enough to support craze formation and fail at small strains through
+chain pullout at the interface. Once chains have formed an average of about one
+entanglement across the interface, a stable craze is formed throughout the
+sample. The failure stress of the craze rises with welding time and the mode of
+craze breakdown changes from chain pullout to chain scission as the interface
+approaches bulk strength. The interfacial fracture energy $G_I$ is calculated
+by coupling the simulation results to a continuum fracture mechanics model. As
+in experiment, $G_I$ increases as $t^{1/2}$ before saturating at the average
+bulk fracture energy $G_b$. As in previous simulations of shear strength,
+saturation coincides with the recovery of the bulk entanglement density. Before
+saturation, $G_I$ is proportional to the areal density of interfacial
+entanglements. Immiscibiltiy limits interdiffusion and thus suppresses
+entanglements at the interface. Even small degrees of immisciblity reduce
+interfacial entanglements enough that failure occurs by chain pullout and $G_I
+\ll G_b$.",1410.1917v1
+2014-11-13,Stretched String with Self-Interaction at High Resolution: Spatial Sizes and Saturation,"We model the (holographic) QCD Pomeron as a long and stretched (fixed impact
+parameter) transverse quantum string in flat $D_\perp=3$ dimensions. After
+discretizing the string in $N$ string bits, we analyze its length, mass and
+spatial distribution for large $N$ or low-x ($x=1/N$), and away from its
+Hagedorn point. The string bit distribution shows sizable asymmetries in the
+transverse plane that may translate to azimuthal asymmetries in primordial
+particle production in the Pomeron kinematics, and the flow moments in minimum
+bias $pp$ and $pA$ events. At moderately low-x and relatively small string
+self-interactions $g_s\approx \alpha_s$ (the gauge coupling), a pre-saturation
+phase is identified whereby the string transverse area undergoes a sharp
+transition from a large diffusive growth to a small fixed size area set by few
+string lengths $l_s$. For lower values of $x$ the transverse string bit density
+is shown to increase as $1/x$ before saturating at the Bekenstein bound of one
+bit per Planck area with the Planck length $l_P/l_s\approx \alpha_s^{2/3}$. We
+argue that the effects of the AdS$_5$ curvature on the interacting string maybe
+estimated using an effective transverse dimension between the interacting
+string bits. The result is a smoother transition with a transverse string bit
+density increasing as $1/x^{0.31}$.",1411.3653v2
+2015-02-10,Ultrafast dynamic conductivity and scattering rate saturation of photoexcited charge carriers in silicon investigated with a midinfrared continuum probe,"We employ ultra-broadband terahertz-midinfrared probe pulses to characterize
+the optical response of photoinduced charge-carrier plasmas in high-resistivity
+silicon in a reflection geometry, over a wide range of excitation densities
+(10^{15}-10^{19} cm^{-3}) at room temperature. In contrast to conventional
+terahertz spectroscopy studies, this enables one to directly cover the
+frequency range encompassing the resultant plasma frequencies. The intensity
+reflection spectra of the thermalized plasma, measured using sum-frequency
+(up-conversion) detection of the probe pulses, can be modeled well by a
+standard Drude model with a density-dependent momentum scattering time of
+approx. 200 fs at low densities, reaching approx. 20 fs for densities of
+approx. 10^{19} cm^{-3}, where the increase of the scattering rate saturates.
+This behavior can be reproduced well with theoretical results based on the
+generalized Drude approach for the electron-hole scattering rate, where the
+saturation occurs due to phase-space restrictions as the plasma becomes
+degenerate. We also study the initial sub-picosecond temporal development of
+the Drude response, and discuss the observed rise in the scattering time in
+terms of initial charge-carrier relaxation, as well as the optical response of
+the photoexcited sample as predicted by finite-difference time-domain
+simulations.",1502.02829v1
+2015-06-04,Subcentric linking systems,"Linking systems are crucial for studying the homotopy theory of fusion
+systems, but are also of interest from an algebraic point of view. We propose a
+definition of a linking system associated to a saturated fusion system which is
+more general than the one currently in the literature and thus allows a more
+flexible choice of objects of linking systems. More precisely, we define
+subcentric subgroups of fusion systems in a way that every quasicentric
+subgroup of a saturated fusion system is subcentric. Whereas the objects of
+linking systems in the current definition are always quasicentric, the objects
+of our linking systems only need to be subcentric. We prove that, associated to
+each saturated fusion system $\mathcal{F}$, there is a unique linking system
+whose objects are the subcentric subgroups of $\mathcal{F}$. Furthermore, the
+nerve of such a subcentric linking system is homotopy equivalent to the nerve
+of the centric linking system associated to $\mathcal{F}$. We believe that the
+existence of subcentric linking systems opens a new way for a classification of
+fusion systems of characteristic $p$-type. The various results we prove about
+subcentric subgroups give furthermore some evidence that the concept is of
+interest for studying extensions of linking systems and fusion systems.",1506.01458v3
+2015-07-13,Compactification tuning for nonlinear localized modes in sawtooth lattices,"We discuss the properties of nonlinear localized modes in sawtooth lattices,
+in the framework of a discrete nonlinear Schr\""odinger model with general
+on-site nonlinearity. Analytic conditions for existence of exact compact
+three-site solutions are obtained, and explicitly illustrated for the cases of
+power-law (cubic) and saturable nonlinearities. These nonlinear compact modes
+appear as continuations of linear compact modes belonging to a flat dispersion
+band. While for the linear system a compact mode exists only for one specific
+ratio of the two different coupling constants, nonlinearity may lead to
+compactification of otherwise non-compact localized modes for a range of
+coupling ratios, at some specific power. For saturable lattices, the
+compactification power can be tuned by also varying the nonlinear parameter.
+Introducing different on-site energies and anisotropic couplings yield further
+possibilities for compactness tuning. The properties of strongly localized
+modes are investigated numerically for cubic and saturable nonlinearities, and
+in particular their stability over large parameter regimes is shown. Since the
+linear flat band is isolated, its compact modes may be continued into compact
+nonlinear modes both for focusing and defocusing nonlinearities. Results are
+discussed in relation to recent realizations of sawtooth photonic lattices.",1507.03433v2
+2015-08-18,Scheme to increase the output average spectral flux of the European XFEL at $14.4$ keV,"Techniques like inelastic X-ray scattering (IXS) and nuclear resonance
+scattering (NRS) are currently limited by the photon flux available at X-ray
+sources. At $14.4$ keV, third generation synchrotron radiation sources produce
+a maximum of $10^{10}$ photons per second in a meV bandwidth. In this work we
+discuss about the possibility of increasing this flux a thousand-fold by
+exploiting high repetition rate self-seeded pulses at the European XFEL. Here
+we report on a feasibility study for an optimized configuration of the SASE2
+beamline at the European XFEL which combines self-seeding and undulator
+tapering techniques in order to increase the average spectral flux at $14.4$
+keV. In particular, we propose to perform monochromatization at $7.2$ keV with
+the help of self-seeding, and amplify the seed in the first part of output
+undulator. The amplification process can be stopped at a position well before
+saturation, where the electron beam gets considerable bunching at the 2nd
+harmonic of the coherent radiation. A second part of the output undulator
+follows, tuned to the 2nd harmonic frequency, i.e. at $14.4$ keV and is used to
+obtain saturation at this energy. One can further prolong the exchange of
+energy between the photon and the electron beam by tapering the last part of
+the output undulator. We performed start-to-end simulations and demonstrate
+that self-seeding, combined with undulator tapering, allows one to achieve more
+than a hundred-fold increase in average spectral flux compared with the nominal
+SASE regime at saturation, resulting in a maximum flux of order $10^{13}$
+photons per second in a meV bandwidth.",1508.04339v1
+2015-09-08,Relativistic Mean-Field Models with Scaled Hadron Masses and Couplings: Hyperons and Maximum Neutron Star Mass,"An equation of state of cold nuclear matter with an arbitrary isotopic
+composition is studied within a relativistic mean-field approach with hadron
+masses and coupling constants depending self-consistently on the scalar
+mean-field. All hadron masses decrease universally with the scalar field
+growth, whereas meson-nucleon coupling constants can vary differently. More
+specifically we focus on two modifications of the KVOR model studied
+previously. One extension of the model (KVORcut) demonstrates that the equation
+of state stiffens if the increase of the scalar-field magnitude with the
+density is bounded from above at some value for baryon densities above the
+saturation nuclear density. This can be realized if the nucleon vector-meson
+coupling constant changes rapidly as a function of the scalar field slightly
+above the desired value. The other version of the model (MKVOR) utilizes a
+smaller value of the nucleon effective mass at the nuclear saturation density
+and a saturation of the scalar field in the isospin asymmetric matter induced
+by a strong variation of the nucleon isovector-meson coupling constant as
+function of the scalar field. A possibility of hyperonization of the matter in
+neutron star interiors is incorporated. Our equations of state fulfill majority
+of known empirical constraints including the pressure-density constraint from
+heavy-ion collisions, direct Urca constraint, gravitational-baryon mass
+constraint for the pulsar J0737-3039B, and the constraint on the maximum mass
+of the neutron stars.",1509.02538v2
+2015-09-09,Pinning down QCD-matter shear viscosity in ultrarelativistic heavy-ion collisions via EbyE fluctuations using pQCD + saturation + hydrodynamics,"We introduce an event-by-event pQCD + saturation + hydro (""EKRT"") framework
+for high-energy heavy-ion collisions, where we compute the produced fluctuating
+QCD-matter energy densities from next-to-leading order (NLO) perturbative QCD
+(pQCD) using saturation to control soft particle production, and describe the
+space-time evolution of the QCD matter with viscous hydrodynamics, event by
+event (EbyE). We compare the computed centrality dependence of hadronic
+multiplicities, p_T spectra and flow coefficients v_n against LHC and RHIC
+data. We compare also the computed EbyE probability distributions of relative
+fluctuations of v_n, as well as correlations of 2 and 3 event-plane angles,
+with LHC data. Our systematic multi-energy and -observable analysis not only
+tests the initial state calculation and applicability of hydrodynamics, but
+also makes it possible to constrain the temperature dependence of the shear
+viscosity-to-entropy ratio, eta/s(T), of QCD matter in its different phases.
+Remarkably, we can describe all these different flow observables and
+correlations consistently with eta/s(T) that is independent of the collision
+energy.",1509.02767v1
+2015-11-23,Diffractive Dijet Production in Deep Inelastic Scattering and Photon-Hadron Collisions in the Color Glass Condensate,"We study exclusive dijet production in coherent diffractive processes in deep
+inelastic scattering and real (and virtual) photon-hadron ($\gamma^{(*)}$-h)
+collisions in the Color Glass Condensate formalism at leading order. We show
+that the diffractive dijet cross section is sensitive to the color-dipole
+orientation in the transverse plane, and is a good probe of possible
+correlations between the $q\bar{q}$-dipole transverse separation vector $\r$
+and the dipole impact parameter $\b$. We also investigate the diffractive dijet
+azimuthal angle correlations and $t$-distributions in $\gamma^{(*)}$-h
+collisions and show that they are sensitive to gluon saturation effects in the
+small-$x$ region. In particular, we show that the $t$-distribution of
+diffractive dijet photo-production off a proton target exhibits a dip-type
+structure in the saturation region. This effect is similar to diffractive
+vector meson production. Besides, at variance with the inclusive case, the
+effect of saturation leads to stronger azimuthal correlations between the jets.",1511.07452v2
+2015-12-03,Atom-Field Entanglement in Cavity QED: Nonlinearity and Saturation,"We investigate the degree of entanglement between an atom and a driven cavity
+mode, in the presence of dissipation. Previous work has shown that in the limit
+of weak driving fields, the steady state entanglement is proportional to the
+square of the driving intensity. This quadratic dependence is due to the
+generation of entanglement by the creation of pairs of photons/excitations. In
+this work we investigate the entanglement between an atom and a cavity in the
+presence of multiple photons. Nonlinearity of the atomic response is needed to
+generate entanglement, but as that nonlinearity saturates the entanglement
+vanishes. We posit that this is due to spontaneous emission, which puts the
+atom in the ground state and the atom-field state into a direct product state.
+An intermediate value of the driving field, near the field that saturates the
+atomic response, optimizes the atom-field entanglement. In a parameter regime
+for which multiphoton resonances occur, we find that entanglement recurs at
+those resonances. \cite{Shamailov-10} In this regime, we find that the
+entanglement decreases with increaing photon number. We also investigate, in
+the bimodal regime of Alsing et. al.\cite{Alsing-91-DressedState}
+\cite{Alsing-92-DSS}\cite{Carm-15-X}, the entanglement as a function of atom
+and/or cavity detuning. Here we find that there is evidence of a phase
+transition in the entanglement, which occurs at $2\epsilon/g \geq 1$.",1512.00936v2
+2016-01-13,Low-threshold RNGH instabilities in quantum cascade lasers,"A theoretical study on low-threshold multimode instabilities in quantum
+cascade lasers (QCLs) and laser diodes (LDs) is presented. Previously, low
+threshold Risken-Nummedal-Graham-Haken (RNGH) instabilities were reported in
+several experimental studies of QCLs. They were attributed so far to the
+combined effect of the induced grating of carrier population and of a built-in
+saturable absorption feature that may be present in the monolithic
+single-section cavity of these Fabry-P\'erot lasers. Here we show that
+low-threshold RNGH instabilities in QCLs occur due to a carrier coherence
+grating induced in the gain medium and not due to intracavity saturable
+absorption. We find that QCLs with a few mm long cavity exhibit intermittent
+RNGH self-pulsations while regular self-pulsations are possible in short-cavity
+QCLs, with the cavity length of 100 um or smaller. We examine a transient
+behavior to RNGH self-pulsations in short-cavity QCLs and find features that
+resemble cooperative superradiance. Our findings open a practical way of
+achieving ultra-short pulse production regimes in the mid-infrared spectral
+range. Applying same approach to semiconductor laser diodes (LDs) we explain
+the absence of RNGH self-pulsation in LDs based on a quantum well gain media,
+while practically established method for reaching the ultrafast coherent
+emission regimes in LDs is to incorporate a separately contacted saturable
+absorber section in the LD cavity.",1601.03212v2
+2016-02-12,A few-emitter solid-state multi-exciton laser,"We report a combined experimental and theoretical study of non-conventional
+lasing from higher multi-exciton states of a few quantum dot-photonic crystal
+nanocavity. We show that the photon output is fed from saturable quantum
+emitters rather than a non-saturable background despite being rather
+insensitive to the spectral position of the mode. Although the exciton
+transitions of each quantum dot are detuned by up to $160$ cavity linewidths,
+we observe that strong excitation populates a multitude of closely spaced
+multi-exciton states, which partly overlap spectrally with the mode. The
+limited number of emitters is confirmed by a complete saturation of the mode
+intensity at strong pumping, providing sufficient gain to reach stimulated
+emission, whilst being accompanied by a distinct lasing threshold. Detailed
+second-order photon-correlation measurements unambiguously identify the
+transition to lasing for strong pumping and, most remarkably, reveal
+super-thermal photon bunching with $g^{(2)}(0)>2$ below lasing threshold. Based
+on our microscopic theory, a pump-rate dependent $\beta$-factor $\beta(P)$ is
+needed to describe the nanolaser and account for the interplay of multi-exciton
+transitions in the few-emitter gain medium. Moreover, we theoretically predict
+that the super-thermal bunching is related to dipole-anticorrelated
+multi-exciton recombination channels via sub- and super-radiant coupling below
+and above lasing threshold, respectively. Our results provide new insights into
+the microscopic light-matter-coupling of spatially separated emitters coupled
+to a common cavity mode and, thus, provides a complete understanding of
+stimulated emission in nanolasers with discrete emitters.",1602.03998v2
+2016-04-25,Spatially Coupled Turbo-Like Codes,"In this paper, we introduce the concept of spatially coupled turbo-like codes
+(SC-TCs) as the spatial coupling of a number of turbo-like code ensembles. In
+particular, we consider the spatial coupling of Berrou et al. parallel
+concatenated codes (PCCs) and Benedetto et al. serially concatenated codes
+(SCCs). Furthermore, we propose two extensions of braided convolutional codes
+(BCCs), a class of turbo-like codes which have an inherent spatially coupled
+structure, to higher coupling memories, and show that these yield improved
+belief propagation (BP) thresholds as compared to the original BCC ensemble. We
+derive the exact density evolution (DE) equations for SC-TCs and analyze their
+asymptotic behavior on the binary erasure channel. We also consider the
+construction of families of rate-compatible SC-TC ensembles. Our numerical
+results show that threshold saturation of the belief propagation (BP) decoding
+threshold to the maximum a-posteriori threshold of the underlying uncoupled
+ensembles occurs for large enough coupling memory. The improvement of the BP
+threshold is especially significant for SCCs and BCCs, whose uncoupled
+ensembles suffer from a poor BP threshold. For a wide range of code rates,
+SC-TCs show close-to-capacity performance as the coupling memory increases. We
+further give a proof of threshold saturation for SC-TC ensembles with identical
+component encoders. In particular, we show that the DE of SC-TC ensembles with
+identical component encoders can be properly rewritten as a scalar recursion.
+This allows us to define potential functions and prove threshold saturation
+using the proof technique recently introduced by Yedla et al..",1604.07315v2
+2016-06-29,Colorability Saturation Games,"We consider the following two-player game: Maxi and Mini start with the empty
+graph on $n$ vertices and take turns, always adding one additional edge to the
+graph such that the chromatic number is at most $k$, where $k \in \mathbb{N}$
+is a given parameter. The game is over when the graph is saturated and no
+further edge can be inserted. Maxi wants to maximize the length of the game
+while Mini wants to minimize it. The score $s(n,\chi_{>k})$ denotes the number
+of edges in the final graph, given that both players followed an optimal
+strategy.
+  This colorability game belongs to the family of \emph{saturation games} that
+are known to provide beautiful and challenging problems despite being defined
+via simple combinatorial rules. The analysis of colorability saturation games
+has been initiated recently by Hefetz, Krivelevich, Naor, and Stojakovi\'c
+(2016). In this paper, we improve their results by providing almost matching
+lower and upper bounds on the score of the game that hold for arbitrary choices
+of $k$ and $n>k$. In addition, we study the specific game with $k=4$ in more
+details and prove that its score is $n^2/3+O(n)$.",1606.09099v6
+2016-07-01,Forward production of Drell-Yan dileptons at high energies and low dilepton invariant masses in a $k_t$-factorization approach: Do we see onset of saturation?,"We discuss Drell-Yan production of dileptons at high energies in forward
+rapidity region in a hybrid high-energy approach. This approach uses
+unintegrated gluon distributions in one proton and collinear quark/antiquark
+distributions in the second proton. Corresponding momentum-space formula for
+the differential cross sections in high-energy approximation has been derived.
+The relation to the commonly used dipole approach is discussed. We conclude and
+illustrate that some results of the dipole approaches are too approximate, as
+far as kinemtics is considered, and in fact cannot be used for real
+experiments. We find that the dipole formula is valid only in very
+forward/backward rapidity regions ($|y| >$ 5). Some differential cross sections
+for low-mass dilepton production are shown and compared to the LHCb and ATLAS
+experimental data. In distinction to dipole approaches, we include four
+Drell-Yan structure functions (the impact of interference structure functions
+is rather small for typical experimental cuts). We find that both side
+contributions ($g q/\bar q$ and $q/\bar q g$) have to be included even for the
+LHCb rapidity coverage which is in contradiction with what is usually done in
+the dipole approach. We present results for different unintegrated gluon
+distributions from the literature (some of them include saturation effects). We
+see no clear hints of saturation even at small $M_{ll}$.",1607.00238v1
+2016-10-12,Symmetry energy and density,"The nuclear equation-of-state is a topic of highest current interest in
+nuclear structure and reactions as well as in astrophysics. In particular, the
+equation-of-state of asymmetric matter and the symmetry energy representing the
+difference between the energy densities of neutron matter and of symmetric
+nuclear matter are not sufficiently well constrained at present. The density
+dependence of the symmetry energy is conventionally expressed in the form of
+the slope parameter L describing the derivative with respect to density of the
+symmetry energy at saturation. Results deduced from nuclear structure and
+heavy-ion reaction data are distributed around a mean value L=60 MeV.
+  Recent studies have more thoroughly investigated the density range that a
+particular observable is predominantly sensitive to. Two thirds of the
+saturation density is a value typical for the information contained in
+nuclear-structure data. Higher values exceeding saturation have been shown to
+be probed with meson production and collective flows at incident energies in
+the range of up to about 1 GeV/nucleon.
+  From the measurement of the elliptic-flow ratio of neutrons with respect to
+light charged particles in recent experiments at the GSI laboratory, a new more
+stringent constraint for the symmetry energy at suprasaturation density has
+been deduced. It confirms, with a considerably smaller uncertainty, the
+moderately soft to linear density dependence of the symmetry energy previously
+deduced from the FOPI-LAND data. Future opportunities offered by FAIR will be
+discussed.",1610.03650v1
+2016-10-20,Strong correlations of neutron star radii with the slopes of nuclear matter incompressibility and symmetry energy at saturation,"We examine the correlations of neutron star radii with the nuclear matter
+incompressibility, symmetry energy, and their slopes, which are the key
+parameters of the equation of state (EoS) of asymmetric nuclear matter. The
+neutron star radii and the EoS parameters are evaluated using a representative
+set of 24 Skyrme-type effective forces and 18 relativistic mean field models,
+and two microscopic calculations, all describing 2$M_\odot$ neutron stars.
+Unified EoSs for the inner-crust-core region have been built for all the
+phenomenological models, both relativistic and non-relativistic. Our
+investigation shows the existence of a strong correlation of the neutron star
+radii with the linear combination of the slopes of the nuclear matter
+incompressibility and the symmetry energy coefficients at the saturation
+density. Such correlations are found to be almost independent of the neutron
+star mass in the range $0.6\text{-}1.8M_{\odot}$. This correlation can be
+linked to the empirical relation existing between the star radius and the
+pressure at a nucleonic density between one and two times saturation density,
+and the dependence of the pressure on the nuclear matter incompressibility, its
+slope and the symmetry energy slope. The slopes of the nuclear matter
+incompressibility and the symmetry energy coefficients as estimated from the
+finite nuclei data yield the radius of a $1.4M_{\odot}$ neutron star in the
+range $11.09\text{-}12.86$ km.",1610.06344v1
+2016-10-22,Massive Corrections to Entanglement in Minimal E8 Toda Field Theory,"In this letter we study the exponentially decaying corrections to saturation
+of the second R\'enyi entropy of one interval of length L in minimal E8 Toda
+field theory. It has been known for some time that the entanglement entropy of
+a massive quantum field theory in 1+1 dimensions saturates to a constant value
+for m1 L <<1 where m1 is the mass of the lightest particle in the spectrum.
+Subsequently, results by Cardy, Castro-Alvaredo and Doyon have shown that there
+are exponentially decaying corrections to this behaviour which are
+characterised by Bessel functions with arguments proportional to m1 L. For the
+von Neumann entropy the leading correction to saturation takes the precise
+universal form -K0(2m1 L)/8 whereas for the R\'enyi entropies leading
+corrections which are proportional to K0(m1 L) are expected. Recent numerical
+work by P\'almai for the second R\'enyi entropy of minimal E8 Toda has found
+next-to-leading order corrections decaying as exp(-2m1 L) rather than the
+expected exp(-m1 L). In this paper we investigate the origin of this result and
+show that it is incorrect. An exact form factor computation of correlators of
+branch point twist fields reveals that the leading corrections are proportional
+to K0(m1 L) as expected.",1610.07040v2
+2016-11-05,Improved measurement of the hyperfine structure of the laser cooling level $4f^{12}(^3 H_6)5d_{5/2}6s^2$ $(J=9/2)$ in $^{169}$Tm,"We report on the improved measurement of the hyperfine structure of
+$4f^{12}(^3 H_6)5d_{5/2}6s^2$ $(J=9/2)$ excited state in Tm-169 which is
+involved in the second-stage laser cooling of Tm. To measure the absolute value
+of the hyperfine splitting interval we used Doppler-free frequency modulation
+saturated absorption spectroscopy of Tm atoms in a vapor cell. The sign of the
+hyperfine constant was determined independently by spectroscopy of laser cooled
+Tm atoms. The hyperfine constant of the level equals $A_J=-422.112(32)$ MHz
+that corresponds to the energy difference between two hyperfine sublevels of
+$-2110.56(16)$~MHz. In relation to the saturated absorption measurement we
+quantitatively treat contributions of various mechanisms into the line
+broadening and shift. We consider power broadening in the case when Zeeman
+sublevels of atomic levels are taken into account. We also discuss the line
+broadening due to frequency modulation and relative intensities of transitions
+in saturated-absorption experiments.",1611.01679v1
+2016-12-13,Expectation values of twist fields and universal entanglement saturation of the free massive boson,"The evaluation of vacuum expectation values (VEVs) in massive integrable
+quantum field theory (QFT) is a nontrivial renormalization-group ""connection
+problem"" -- relating large and short distance asymptotics -- and is in general
+unsolved. This is particularly relevant in the context of entanglement entropy,
+where VEVs of branch-point twist fields give universal saturation predictions.
+We propose a new method to compute VEVs of twist fields associated to
+continuous symmetries in QFT. The method is based on a differential equation in
+the continuous symmetry parameter, and gives VEVs as infinite form-factor
+series which truncate at two-particle level in free QFT. We verify the method
+by studying U(1) twist fields in free models, which are simply related to the
+branch-point twist fields. We provide the first exact formulae for the VEVs of
+such fields in the massive uncompactified free boson model, checking against an
+independent calculation based on angular quantization. We show that logarithmic
+terms, overlooked in the original work of Callan and Wilczek [Phys. Lett. B333
+(1994)], appear both in the massless and in the massive situations. This
+implies that, in agreement with numerical form-factor observations by Bianchini
+and Castro-Alvaredo [Nucl. Phys. B913 (2016)], the standard power-law
+short-distance behavior is corrected by a logarithmic factor. We discuss how
+this gives universal formulae for the saturation of entanglement entropy of a
+single interval in near-critical harmonic chains, including log log
+corrections.",1612.04238v2
+2017-01-09,On the tensor semigroup of affine kac-moody lie algebras,"In this paper, we are interested in the decomposition of the tensor product
+of two representations of a symmetrizable Kac-Moody Lie algebra $\mathfrak g$.
+Let $P\_+$ be the set of dominant integral weights. For $\lambda\in P\_+$ ,
+$L(\lambda)$ denotes the irreducible, integrable, highest weight representation
+of g with highest weight $\lambda$. Let $P\_{+,\mathbb Q}$ be the rational
+convex cone generated by $P\_+$. Consider the tensor cone $\Gamma(\mathfrak g)
+:= \{(\lambda\_1 ,\lambda\_2, \mu) $\in$ P\_{+,\mathbb Q}^3\,| \exists N
+\textgreater{} 1 L(N\mu) \subset L(N \lambda\_1)\otimes L(N \lambda\_2)\}$. If
+$\mathfrak g$ is finite dimensional, $\Gamma(\mathfrak g)$ is a polyhedral
+convex cone described in 2006 by Belkale-Kumar by an explicit finite list of
+inequalities. In general, $\Gamma(\mathfrak g)$ is nor polyhedral, nor closed.
+In this article we describe the closure of $\Gamma(\mathfrak g)$ by an explicit
+countable family of linear inequalities, when $\mathfrak g$ is untwisted
+affine. This solves a Brown-Kumar's conjecture in this case. We also obtain
+explicit saturation factors for the semigroup of triples $(\lambda\_1,
+\lambda\_2 , \mu) $\in$ P\_+^3$ such that $L(\mu) $\subset$ L(\lambda\_1)
+\otimes L(\lambda\_2)$. Note that even the existence of such saturation factors
+is not obvious since the semigroup is not finitely generated. For example, in
+type $A , we prove that any integer $d\geq 2$ is a saturation factor,
+generalizing the case ${\tilde A}\_1$ shown by Brown-Kumar.",1701.02176v2
+2017-01-31,Attainability of the quantum information bound in pure state models,"The attainability of the quantum Cram\'er-Rao bound [QCR], the ultimate limit
+in the precision of the estimation of a physical parameter, requires the
+saturation of the quantum information bound [QIB]. This occurs when the Fisher
+information associated to a given measurement on the quantum state of a system
+which encodes the information about the parameter coincides with the quantum
+Fisher information associated to that quantum state. Braunstein and Caves [PRL
+{\bf 72}, 3439 (1994)] have shown that the QIB can always be achieved via a
+projective measurement in the eigenvectors basis of an observable called
+symmetric logarithmic derivative. However, such projective measurement depends,
+in general, on the value of the parameter to be estimated. Requiring,
+therefore, the previous knowledge of the quantity one is trying to estimate.
+For this reason, it is important to investigate under which situation it is
+possible to saturate the QCR without previous information about the parameter
+to be estimated. Here, we show the complete solution to the problem of which
+are all the initial pure states and the projective measurements that allow the
+global saturation of the QIB, without the knowledge of the true value of the
+parameter, when the information about the parameter is encoded in the system by
+a unitary process.",1701.09144v1
+2017-02-24,A step function density profile model for the convective stability of CO2 geological sequestration,"The convective stability associated with carbon sequestration is usually
+investigated by adopting an unsteady diffusive basic profile. The method of
+normal modes is not applicable due to the time dependence of the nonlinear base
+profile. Therefore, the instability is quantified either in terms of critical
+times at which the boundary layer instability sets in or in terms of long time
+evolution of initial disturbances. This paper adopts an unstably stratified
+basic profile having a step function density with top heavy carbon saturated
+layer (boundary layer) overlying a lighter carbon free layer (ambient brine).
+The resulting configuration resembles that of the Rayleigh-Taylor problem with
+buoyancy diffusion at the interface separating the two layers. The
+discontinuous reference state satisfies the governing system of equations and
+boundary conditions and pertains to an unstably stratified motionless state.
+Our model accounts for anisotropy in both diffusion and permeability and
+chemical reaction between the carbon dioxide rich brine and host mineralogy. We
+proceed by supposing that the carbon dioxide that has accumulated below the top
+cap rock forms a layer of carbon saturated brine of some thickness that
+overlies a carbon-free brine layer. The resulting stratification remains stable
+until the thickness of the carbon saturated layer is sufficient to induce the
+fluid to overturn. With this formulation for the reference state, the stability
+calculations will be in terms of critical boundary layer thickness instead of
+critical times, although the two formulations are homologous. This approach is
+tractable by the classical normal mode analysis. Even though it yields only
+conservative threshold instability conditions, it offers the advantage for an
+analytically tractable linear and weakly nonlinear studies.",1702.07623v1
+2017-04-10,Slow light in saturable absorbers : Progress in the resolution of a controversy,"There are two opposing models in the analysis of the slow transmission of
+light pulses through saturable absorbers. The canonical incoherent bleaching
+model simply explains the slow transmission by combined effects of saturation
+and of non-instantaneous response of the medium resulting in absorption of the
+front part of the incident pulse larger than that of its rear. The second
+model, referred to as the coherent-population-oscillations (CPO) model,
+considers light beams whose intensity is slightly pulse modulated and
+attributes the time delay of the transmitted pulse to a reduction of the group
+velocity. We point out some inconsistencies in the CPO model and show that the
+two models lie in reality on the same hypotheses, the equations derived in the
+duly rectified CPO model being local expressions of the integral equations
+obtained in the incoherent bleaching model. For large modulation index, the CPO
+model, based on linearized equations, breaks down. The incoherent bleaching
+model then predicts that the transmitted light should vanish when the intensity
+of the incident light is strictly zero. This point is confirmed by the
+experiments that we have performed on ruby with square-wave incident pulses and
+we show that the whole shape of the observed pulses agrees with that derived
+analytically by means of the incoherent bleaching model. We also determine in
+this model the corresponding evolution of the fluorescence light, which seems
+to have been evidenced in other experiments.",1704.02820v2
+2017-05-08,Empirical model of the Gibbs free energy for saline solutions of arbitrary concentration: Application for H2O-NaCl solutions at 423.15K-573.15K and pressures from saturation up to 5kbar,"An empirical model of the concentration dependence of the excess Gibbs free
+energy Gex for saline solutions is proposed. Our simple analytical form of Gex
+allows obtaining equations of state of saline solutions equally precise in the
+whole range of the salt concentrations, from dilute solutions up to the limit
+of solubility. Our equation for Gex includes one term responsible for
+concentration dependence of Gex at low salt concentrations and two terms of
+Margules type dependent on powers of mole fractions of the components. These
+terms contain four parameters dependent on temperature and pressure. As an
+example of application of the proposed model we took the system H2O-NaCl. For
+fixed T and P, our four-parameter form of Gex allows precisely reproduce
+experimental data for NaCl water solutions, including both regions of low and
+high concentrations. An introduction of temperature dependence of the
+parameters allowed us to build a precise analytic fit of experimental data on
+osmotic coefficients of NaCl solutions for saturation pressures of NaCl at
+temperatures 423.15K-573.15K. On the basis of PVTx data by Driesner (2007) the
+model was extended towards pressures up to 5kbar. Our form of Gex allows
+obtaining the molar volumes, activities of components and other thermodynamic
+properties of NaCl-H2O solutions in the range of temperatures 423.15K-573.15K
+and pressures from saturation up to 5kbar in the whole range of concentrations
+possible for H2O-NaCl solutions (from zero up to approximately 10 molal at
+573.15K).",1705.02901v2
+2017-06-11,A numerical method for efficient 3D inversions using Richards equation,"Fluid flow in the vadose zone is governed by Richards equation; it is
+parameterized by hydraulic conductivity, which is a nonlinear function of
+pressure head. Investigations in the vadose zone typically require
+characterizing distributed hydraulic properties. Saturation or pressure head
+data may include direct measurements made from boreholes. Increasingly, proxy
+measurements from hydrogeophysics are being used to supply more spatially and
+temporally dense data sets. Inferring hydraulic parameters from such datasets
+requires the ability to efficiently solve and deterministically optimize the
+nonlinear time domain Richards equation. This is particularly important as the
+number of parameters to be estimated in a vadose zone inversion continues to
+grow. In this paper, we describe an efficient technique to invert for
+distributed hydraulic properties in 1D, 2D, and 3D. Our algorithm does not
+store the Jacobian, but rather computes the product with a vector, which allows
+the size of the inversion problem to become much larger than methods such as
+finite difference or automatic differentiation; which are constrained by
+computation and memory, respectively. We show our algorithm in practice for a
+3D inversion of saturated hydraulic conductivity using saturation data through
+time. The code to run our examples is open source and the algorithm presented
+allows this inversion process to run on modest computational resources.",1706.03381v1
+2017-06-21,Nuclear modification of forward $D$ production in pPb collisions at the LHC,"We study nuclear modification factors for single $D$ meson and semileptonic
+decay lepton $l$ ($=e,\mu$) production in minimum bias proton-nucleus (p$A$)
+collisions at the LHC in the color-glass-condensate (CGC) framework at leading
+order in strong coupling. In our numerical computations, transverse momentum
+($k_\perp$) dependent multi-point Wilson line correlators are employed for
+describing target nucleus for p$A$ and proton for pp. The projectile proton is
+treated with unintegrated gluon distribution function, which is also
+$k_\perp$-dependent. The rapidity evolutions of these functions in the small
+Bjorken $x$ region are taken into account by solving running coupling
+Balitsky-Kovchegov (BK) equation at leading logarithmic accuracy. For
+simplicity, we employ Kartvelishvili's type fragmentation function and a simple
+model for lepton energy distribution from seileptonic decay, respectively, to
+compute differential cross sections for $D$ and $l$ production. The gluon
+saturation scale inside the heavy nucleus is enhanced and dependent on $x$,
+which we take into account by replacing the initial saturation scale in the BK
+equation with a larger value for the heavy nucleus. We show that the saturation
+effect leads to perceptible nuclear suppression of $D$ production at forward
+rapidity. Our numerical results predict similar nuclear suppressions in p$A$
+collisions for forward $l$ production at lower transverse momentum
+$p_\perp<2\;{\rm GeV}$. Numerical tables on the nuclear modifications of $D$
+and $l$ are listed in this note.",1706.06728v2
+2017-07-18,Saturation properties of helium drops from a Leading Order description,"Saturation properties are directly linked to the short-range scale of the
+two-body interaction of the particles. The case of helium is particular, from
+one hand the two-body potential has a strong repulsion at short distances. On
+the other hand, the extremely weak binding of the helium dimer locates this
+system very close to the unitary limit allowing for a description based on an
+effective theory. At leading order of this theory a two- and a three-body term
+appear, each one characterized by a low energy constant. In a potential model
+this description corresponds to a soft potential model with a two-body term
+purely attractive plus a three-body term purely repulsive constructed to
+describe the dimer and trimer binding energies. Here we analyse the capability
+of this model to describe the saturation properties making a direct link
+between the low energy scale and the short-range correlations. We will show
+that the energy per particle, $E_N/N$, can be obtained with reasonable accuracy
+at leading order extending the validity of this approximation, characterizing
+universal behavior in few-boson systems close to the unitary limit, to the
+many-body system.",1707.05628v2
+2017-08-30,Effects of Arrival Type and Degree of Saturation on Queue Length Estimation at Signalized Intersections,"Purpose of this study is evaluation of the relationship between different
+arrival types and degree of saturation (X) with overestimations of HCM 2010
+procedure for estimating the back of queue within a study area. Further
+analysis is performed to establish the relationship between queue length and
+delay and also between each of them individually and X in cases with
+overestimation. The analyses are based on the 50th percentile queue lengths for
+data collected at four signalized intersections along a corridor in 4 time
+periods (off peak period and AM, Noon and PM peak periods). Based on the
+statistical test results, arrival type did not play a role in overestimations.
+However, there is a significant relationship between the overestimations on
+minor and major street and different ranges of X. On minor streets, about 59%
+of the overestimations are at X values less than half; while near 23% of the
+overestimations are at oversaturation condition with X values greater than 1.
+The relationship between amount of overestimations and degree of saturation
+should be established based on the numerical amount of overestimations versus X
+values rather than the relative amounts; since the statistical comparison
+between the relative amount of overestimations and X values, resulted in a
+wrong idea of the real world condition. There was a significant correlation
+between field queue and delay data of the cases with overestimated queue length
+in all cases on major and minor streets. Also, field queue is correlated to X,
+in all cases on minor and major streets.",1708.09439v1
+2017-09-05,Constraints on Flavored 2d CFT Partition Functions,"We study the implications of modular invariance on 2d CFT partition functions
+with abelian or non-abelian currents when chemical potentials for the charges
+are turned on, i.e. when the partition functions are ""flavored"". We begin with
+a new proof of the transformation law for the modular transformation of such
+partition functions. Then we proceed to apply modular bootstrap techniques to
+constrain the spectrum of charged states in the theory. We improve previous
+upper bounds on the state with the greatest ""mass-to-charge"" ratio in such
+theories, as well as upper bounds on the weight of the lightest charged state
+and the charge of the weakest charged state in the theory. We apply the
+extremal functional method to theories that saturate such bounds, and in
+several cases we find the resulting prediction for the occupation numbers are
+precisely integers. Because such theories sometimes do not saturate a bound on
+the full space of states but do saturate a bound in the neutral sector of
+states, we find that adding flavor allows the extremal functional method to
+solve for some partition functions that would not be accessible to it
+otherwise.",1709.01533v3
+2018-02-28,Photonic glass for high contrast structural color,"Non-iridescent structural colors based on disordered arrangement of
+monodisperse spherical particles, also called photonic glass, show low color
+saturation due to gradual transition in reflectivity. No significant
+improvement is usually expected from particles optimization, as the Mie
+resonances are broad for small dielectric particles with moderate refractive
+index. Moreover, the short range order of a photonic glass alone is also
+insufficient to cause sharp spectral features. We show here, that the
+combination of a well-chosen particle geometry with the short range order of a
+photonic glass has strong synergetic effects. We demonstrate how core-shell
+particles can be used to obtain a sharp transition in the reflection spectrum
+of photonic glass which is essential to achieve a strong color saturation. The
+Fourier transform required for a highly saturated color can be achieved by
+shifting the first zero position of the motif Fourier transform to smaller wave
+numbers in respect to the peak of the lattice Fourier transform. We show that
+this can be obtained by choosing a non-monotonous refractive index distribution
+from the center of the particle through the shell and into the background
+material. The first-order theoretical predictions are confirmed by numerical
+simulations.",1802.10536v1
+2018-03-05,Numerical Simulation of Oscillating Multiphase Heat Transfer in Parallel plates using Pseudopotential Multiple-Relaxation-Time Lattice Boltzmann Method,"Multiphase flows frequently occur in many important engineering and
+scientific applications, but modeling of such flows is a rather challenging
+task due to complex interfacial dynamics between different phases, let alone if
+the flow is oscillating in the porous media. Using humid air as the working
+fluid in the thermoacoustic refrigerator is one of the research focus to
+improve the thermoacoustic performance, but the corresponding effect is the
+condensation of humid air in the thermal stack. Due to the small sized spacing
+of thermal stack and the need to explore the detailed condensation process in
+oscillating flow, a mesoscale numerical approach need to be developed. Over the
+decades, several types of Lattice Boltzmann (LB) models for multiphase flows
+have been developed under different physical pictures, for example the
+color-gradient model, the Shan-Chen model, the nonideal pressure tensor model
+and the HSD model. In the current study, a pseudopotential
+Multiple-Relaxation-Time (MRT) LBM simulation was utilized to simulate the
+incompressible oscillating flow and condensation in parallel plates. In the
+initial stage of condensation, the oscillating flow benefits to accumulate the
+saturated vapor at the exit regions, and the velocity vector of saturated vapor
+clearly showed the flow over the droplets. It was also concluded that if the
+condensate can be removed out from the parallel plates, the oscillating flow
+and condensation will continuously feed the cold surface to form more water
+droplets. The effect of wettability to the condensation was discussed, and it
+turned out that by increasing the wettability, the saturated water vapor was
+easier to condense on the cold walls, and the distance between each pair of
+droplets was also strongly affected by the wettability.",1803.01756v1
+2018-04-06,Performance Comparison of Constant Envelope and Zero-forcing Precoders in Multiuser Massive MIMO,"In this article, the adoption and performance of a constant envelope (CE)
+type spatial precoder is addressed in large-scale multiuser MIMO based cellular
+network. We first formulate an efficient computing solution to obtain the
+antenna samples of such CE precoder. We then evaluate the achievable CE
+precoder based multiuser downlink (DL) system performance and compare it with
+the corresponding performance of more ordinary zero-forcing (ZF) spatial
+precoder. We specifically also analyze how realistic highly nonlinear power
+amplifiers (PAs) affect the achievable DL performance, as the individual PA
+units in large-array or massive MIMO systems are expected to be small, cheap
+and operating close to saturation for increased energy-efficiency purposes. It
+is shown that the largely reduced peak-to-average power ratio (PAPR) of the PA
+input signals in the CE precoder based system allows for pushing the PA units
+harsher towards saturation, while allowing to reach higher
+signal-to-interference-plus-noise ratio (SINRs) at the intended receivers
+compared to the classical ZF precoder based system. The obtained results
+indicate that the CE precoder can outperform the ZF precoder by up to 5-6 dBs,
+in terms of the achievable SINRs, when the PA units are pushed towards their
+saturating region. Such large gains are a substantial benefit when seeking to
+improve the spectral and energy-efficiencies of the mobile cellular networks.",1804.02224v1
+2018-04-09,Non-linear hydrodynamic instability and turbulence in eccentric astrophysical discs with vertical structure,"Non-linear evolution of the parametric instability of inertial waves inherent
+to eccentric discs is studied by way of a new local numerical model. Mode
+coupling of tidal deformation with the disc eccentricity is known to produce
+exponentially growing eccentricities at certain mean-motion resonances.
+However, the details of an efficient saturation mechanism balancing this growth
+still are not fully understood. This paper develops a local numerical model for
+an eccentric quasi-axisymmetric shearing box which generalises the often-used
+cartesian shearing box model. The numerical method is an overall second order
+well-balanced finite volume method which maintains the stratified and
+oscillatory steady-state solution by construction. This implementation is
+employed to study the non-linear outcome of the parametric instability in
+eccentric discs with vertical structure. Stratification is found to constrain
+the perturbation energy near the mid-plane and localise the effective region of
+inertial wave breaking that sources turbulence. A saturated marginally sonic
+turbulent state results from the non-linear breaking of inertial waves and is
+subsequently unstable to large-scale axisymmetric zonal flow structures. This
+resulting limit-cycle behaviour reduces access to the eccentric energy source
+and prevents substantial transport of angular momentum radially through the
+disc. Still, the saturation of this parametric instability of inertial waves is
+shown to damp eccentricity on a time-scale of a thousand orbital periods. It
+may thus be a promising mechanism for intermittently regaining balance with the
+exponential growth of eccentricity from the eccentric Lindblad resonances and
+may also help explain the occurrence of ""bursty"" dynamics such as the superhump
+phenomenon.",1804.03249v1
+2018-04-19,A Non-standard Model for Microbial Enhanced Oil Recovery Including the Oil-water Interfacial Area,"In this work we present a non-standard model for microbial enhanced oil
+recovery including the oil-water interfacial area. Including the interfacial
+area in the model, we eliminate the hysteresis in the capillary pressure
+relationship. One of the characteristics that a surfactant should have, it is
+biological production at the oil-water interface. Therefore, we consider the
+production rate of surfactants not only as a function of the nutrient
+concentration, but also the interfacial area. To solve the model equations, we
+use an efficient and robust linearization scheme that considers a linear
+approximation of the capillary pressure gradient. A comprehensive, 1D
+implementation based on two-point flux approximation of the model is achieved.
+We consider different parameterizations for the interfacial tension and
+residual oil saturation reduction. Illustrative numerical simulations are
+presented, where we study the spatial distribution and evolution in time of the
+average pressure, water saturation, interfacial area, capillary pressure,
+residual oil saturation and bacterial, nutrient and surfactant concentrations.
+Inclusion of the interfacial area in the model leads to different predictions
+of oil recovery. The model can also be used to design new experiments
+contributing to a better understanding and optimization of MEOR.",1804.07085v1
+2018-05-16,Many-Body Quantum Interference and the Saturation of Out-of-Time-Order Correlators,"Out-of-time-order correlators (OTOCs) have been proposed as sensitive probes
+for chaos in interacting quantum systems. They exhibit a characteristic
+classical exponential growth, but saturate beyond the so-called scrambling or
+Ehrenfest time $\tau_{\rm E}$ in the quantum correlated regime. Here we present
+a path-integral approach for the entire time evolution of OTOCs for bosonic
+$N$-particle systems. We first show how the growth of OTOCs up to $\tau_{\rm E}
+= (1/\lambda) \log N$ is related to the Lyapunov exponent $\lambda$ of the
+corresponding chaotic mean-field dynamics in the semiclassical large-$N$ limit.
+Beyond $\tau_{\rm E}$, where simple mean-field approaches break down, we
+identify the underlying quantum mechanism responsible for the saturation. To
+this end we express OTOCs by coherent sums over contributions from different
+mean-field solutions and compute the dominant many-body interference term
+amongst them. Our method further applies to the complementary semiclassical
+limit $\hbar \rightarrow 0$ for fixed $N$, including quantum-chaotic single-
+and few-particle systems.",1805.06377v2
+2018-07-16,CGC/saturation approach: secondary Reggeons and $ρ={\rm Re/Im}$ dependence on energy,"In this letter we demonstrate that a model which is based on the
+CGC/saturation approach, is able to describe soft interaction collisions for
+the wide range of $W=\sqrt{s} = 30 \,GeV \div\, 13 \,TeV$ including the new
+TOTEM data at 13 TeV. We have incorporated the secondary Reggeons in our
+approach which enables us to describe the complete set of the soft data,
+including the energy behaviour of $\rho $ the ratio of the real to imaginary
+parts of the elastic scattering amplitude. We argue that it is premature to
+claim that an odderon contribution is necessary, but estimate its possible
+strength as $1 mb$ to the real part of the amplitude at W = 13 \,TeV. We show
+that the odderon contribution depends on the value of energy leading to ${\rm
+Re A\Lb s, t=0\Rb} $= 8 mb at W=21.2 \,GeV. Bearing this in mind we do not
+believe that $\rho$ at high energies is the appropriate observable for
+detecting the odderon contribution. The successful description of the soft data
+in the wide range of energy strengthens our claim that the CGC/saturation
+approach is the only viable candidate for an effective theory for high energy
+QCD.",1807.06459v2
+2018-07-28,Exclusive diffractive vector meson production: A comparison between the dipole model and the leading twist shadowing approach,"With the imminent construction of an electron-ion collider in the USA, both
+saturation physics and nuclear shadowing physics will be important for the same
+processes for the first time. In particular for exclusive production of vector
+mesons, such as the J/$\psi$. In this paper we investigate the underlying
+assumptions commonly made when phenomenologically investigating this process
+from a shadowing and saturation perspective respectively. We use the bSat model
+which is commonly used to describe saturation physics, and a calculation by
+M.G. Ryskin which is commonly used when describing nuclear shadowing at leading
+twist. It is expected that the bSat model is equivalent to Ryskin's result in
+the hard scattering and non-relativistic limits. By explicitly taking these
+limits we show that the bSat model does indeed become equivalent to Ryskin's
+result. However, two more approximations are needed for this result. Firstly,
+the factorisation and renormalisation scales in the bSat model has to be
+independent of the dipole radius, and secondly, we need to omit a term in the
+overlap between the vector meson and virtual photon wave functions. We show
+that for the typical dipole radius of the J/$\psi$, the different
+approximations off-set each other and the bSat model agrees very well with
+Ryskin's calculation in hard-scattering and non-relativistic limits.",1807.10888v4
+2018-08-24,Magnetoresistance from Fermi Surface Topology,"Extremely large non-saturating magnetoresistance has recently been reported
+for a large number of both topologically trivial and non-trivial materials.
+Different mechanisms have been proposed to explain the observed
+magnetotransport properties, yet without arriving to definitive conclusions or
+portraying a global picture. In this work, we investigate the transverse
+magnetoresistance of materials by combining the Fermi surfaces calculated from
+first principles with the Boltzmann transport theory approach relying on the
+semiclassical model and the relaxation time approximation. We first consider a
+series of simple model Fermi surfaces to provide a didactic introduction into
+the charge-carrier compensation and open-orbit mechanisms leading to
+non-saturating magnetoresistance. We then address in detail magnetotransport in
+three representative materials: (i) copper, a prototypical nearly free-electron
+metal characterized by the open Fermi surface that results in an intricate
+angular magnetoresistance, (ii) bismuth, a topologically trivial semimetal in
+which very large magnetoresistance is known to result from charge-carrier
+compensation, and (iii) tungsten diphosphide WP2, a recently discovered type-II
+Weyl semimetal that holds the record of magnetoresistance in compounds. In all
+three cases our calculations show excellent agreement with both the field
+dependence of magnetoresistance and its anisotropy measured at low
+temperatures. Furthermore, the calculations allow for a full interpretation of
+the observed features in terms of the Fermi surface topology. These results
+will help addressing a number of outstanding questions, such as the role of the
+topological phase in the pronounced large non-saturating magnetoresistance
+observed in topological materials.",1808.08178v1
+2018-08-27,Hydro-micromechanical modeling of wave propagation in saturated granular media,"Biot's theory predicts the wave velocities of a saturated poroelastic
+granular medium from the elastic properties, density and geometry of its dry
+solid matrix and the pore fluid, neglecting the interaction between constituent
+particles and local flow. However, when the frequencies become high and the
+wavelengths comparable with particle size, the details of the microstructure
+start to play an important role. Here, a novel hydro-micromechanical numerical
+model is proposed by coupling the lattice Boltzmann method (LBM) with the
+discrete element method (DEM. The model allows to investigate the details of
+the particle-fluid interaction during propagation of elastic waves While the
+DEM is tracking the translational and rotational motion of each solid particle,
+the LBM can resolve the pore-scale hydrodynamics. Solid and fluid phases are
+two-way coupled through momentum exchange. The coupling scheme is benchmarked
+with the terminal velocity of a single sphere settling in a fluid. To mimic a
+pressure wave entering a saturated granular medium, an oscillating pressure
+boundary condition on the fluid is implemented and benchmarked with
+one-dimensional wave equations. Using a face centered cubic structure, the
+effects of input waveforms and frequencies on the dispersion relations are
+investigated. Finally, the wave velocities at various effective confining
+pressures predicted by the numerical model are compared with with Biot's
+analytical solution, and a very good agreement is found. In addition to the
+pressure and shear waves, slow compressional waves are observed in the
+simulations, as predicted by Biot's theory.",1808.08921v1
+2018-09-27,RPC performance vs FE electoronics and detector parameters,"The first Resistive Plate Chambers detectors were developed for cosmic ray
+experiments, where low rate capability, good time resolution and low cost per
+unit of area were needed. These same features, except for the low rate
+capability, were required in the muon spectrometers of the collider experiments
+like LHC. For this purpose newRPCdetectors with increased rate capability were
+developed. The rate capability improvement has been achieved thanks to the
+transition from streamer to saturated avalanche regime, in which the average
+charge produced in the gas dicharge is smaller. The price to pay for this
+working mode switch is the transfer of the amplification from the detector to
+the FE electorinics. The High luminosity LHC and the future colliders will
+require even greater rate capability in the muon spectrometer compared to the
+current one. For this reason, further improving of the rate capability is
+required. The transition from the saturated avalanche to a low saturated
+avalanche regime moves in this direction and needs a new front end electronics
+with better signal to noise ratio, because the average induced charge on the
+electrode is even smaller. The front end electronics design is crucial for the
+RPC performances. In this paper we discuss the performances of the RPC detector
+changing the front end design and the detector parameters.",1809.10497v1
+2018-10-08,"Quantum chaos, thermalization and entanglement generation in real-time simulations of the BFSS matrix model","We study numerically the onset of chaos and thermalization in the
+Banks-Fischler-Shenker-Susskind (BFSS) matrix model with and without fermions,
+considering Lyapunov exponents, entanglement generation, and quasinormal
+ringing. We approximate the real-time dynamics in terms of the most general
+Gaussian density matrices with parameters which obey self-consistent equations
+of motion, thus extending the applicability of real-time simulations beyond the
+classical limit. Initial values of these Gaussian density matrices are
+optimized to be as close as possible to the thermal equilibrium state of the
+system. Thus attempting to bridge between the low-energy regime with a
+calculable holographic description and the classical regime at high energies,
+we find that quantum corrections to classical dynamics tend to decrease the
+Lyapunov exponents, which is essential for consistency with the
+Maldacena-Shenker-Stanford (MSS) bound at low temperatures. The entanglement
+entropy is found to exhibit an expected ""scrambling"" behavior - rapid initial
+growth followed by saturation. At least at high temperatures the entanglement
+saturation time appears to be governed by classical Lyapunov exponents. Decay
+of quasinormal modes is found to be characterized by the shortest time scale of
+all. We also find that while the bosonic matrix model becomes non-chaotic in
+the low-temperature regime, for the full BFSS model with fermions the leading
+Lyapunov exponent, entanglement saturation time, and decay rate of quasinormal
+modes all remain finite and non-zero down to the lowest temperatures.",1810.03378v1
+2018-10-14,Gas transport in partially-saturated sand packs,"Understanding gas transport in porous media and its mechanism has broad
+applications in various research areas, such as carbon sequestration in deep
+saline aquifers and gas explorations in reservoir rocks. Gas transport is
+mainly controlled by pore space geometrical and morphological characteristics.
+In this study, we apply a physically-based model developed using concepts from
+percolation theory (PT) and the effective-medium approximation (EMA) to better
+understand diffusion and permeability of gas in packings of angular and rounded
+sand grains as well as glass beads. Two average sizes of grain i.e., 0.3 and
+0.5 mm were used to pack sands in a column of 6 cm height and 4.9 cm diameter
+so that the total porosity of all packs was near 0.4. Water content, gas-filled
+porosity (also known as gas content), gas diffusion, and gas permeability were
+measured at different capillary pressures. The X-ray computed tomography method
+and the 3DMA-Rock software package were applied to determine the average pore
+coordination number z. Results showed that both saturation-dependent diffusion
+and permeability of gas showed almost linear behavior at higher gas-filled
+porosities, while deviated substantially from linear scaling at lower gas
+saturations. Comparing the theory with the diffusion and permeability
+experiments showed that the determined value of z ranged between 2.8 and 5.3,
+not greatly different from X-ray computed tomography results. The obtained
+results clearly indicate that the effect of the pore-throat size distribution
+on gas diffusion and permeability was minimal in these sand and glass bead
+packs.",1810.05965v1
+2018-12-27,Can Image Enhancement be Beneficial to Find Smoke Images in Laparoscopic Surgery?,"Laparoscopic surgery has a limited field of view. Laser ablation in a
+laproscopic surgery causes smoke, which inevitably influences the surgeon's
+visibility. Therefore, it is of vital importance to remove the smoke, such that
+a clear visualization is possible. In order to employ a desmoking technique,
+one needs to know beforehand if the image contains smoke or not, to this date,
+there exists no accurate method that could classify the smoke/non-smoke images
+completely. In this work, we propose a new enhancement method which enhances
+the informative details in the RGB images for discrimination of smoke/non-smoke
+images. Our proposed method utilizes weighted least squares optimization
+framework~(WLS). For feature extraction, we use statistical features based on
+bivariate histogram distribution of gradient magnitude~(GM) and Laplacian of
+Gaussian~(LoG). We then train a SVM classifier with binary smoke/non-smoke
+classification task. We demonstrate the effectiveness of our method on Cholec80
+dataset. Experiments using our proposed enhancement method show promising
+results with improvements of 4\% in accuracy and 4\% in F1-Score over the
+baseline performance of RGB images. In addition, our approach improves over the
+saturation histogram based classification methodologies Saturation
+Analysis~(SAN) and Saturation Peak Analysis~(SPA) by 1/5\% and 1/6\% in
+accuracy/F1-Score metrics.",1812.10784v1
+2019-02-23,Effects of multiple scattering on angle-independent structural color in disordered colloidal materials,"Disordered packings of colloidal spheres show angle-independent structural
+color when the particles are on the scale of the wavelength of visible light.
+Previous work has shown that the positions of the peaks in the reflectance
+spectra can be predicted accurately from a single-scattering model that
+accounts for the effective refractive index of the material. This agreement
+shows that the main color peak arises from short-range correlations between
+particles. However, the single-scattering model does not quantitatively
+reproduce the observed color: the main peak in the reflectance spectrum is much
+broader and the reflectance at low wavelengths is much larger than predicted by
+the model. We use a combination of experiment and theory to understand these
+features. We find that one significant contribution to the breadth of the main
+peak is light that is scattered, totally internally reflected from the boundary
+of the sample, and then scattered again. The high reflectance at low
+wavelengths also results from multiple scattering but can be traced to the
+increase in the scattering cross-section of individual particles with
+decreasing wavelength. Both of these effects tend to reduce the saturation of
+the structural color, which limits the use of these materials in applications.
+We show that while the single-scattering model cannot reproduce the observed
+saturations, it can be used to design materials in which multiple scattering is
+suppressed and the color saturated, even in the absence of absorbing
+components.",1902.08733v2
+2019-02-24,Adaptive Estimators Show Information Compression in Deep Neural Networks,"To improve how neural networks function it is crucial to understand their
+learning process. The information bottleneck theory of deep learning proposes
+that neural networks achieve good generalization by compressing their
+representations to disregard information that is not relevant to the task.
+However, empirical evidence for this theory is conflicting, as compression was
+only observed when networks used saturating activation functions. In contrast,
+networks with non-saturating activation functions achieved comparable levels of
+task performance but did not show compression. In this paper we developed more
+robust mutual information estimation techniques, that adapt to hidden activity
+of neural networks and produce more sensitive measurements of activations from
+all functions, especially unbounded functions. Using these adaptive estimation
+techniques, we explored compression in networks with a range of different
+activation functions. With two improved methods of estimation, firstly, we show
+that saturation of the activation function is not required for compression, and
+the amount of compression varies between different activation functions. We
+also find that there is a large amount of variation in compression between
+different network initializations. Secondary, we see that L2 regularization
+leads to significantly increased compression, while preventing overfitting.
+Finally, we show that only compression of the last layer is positively
+correlated with generalization.",1902.09037v2
+2019-03-14,Constraining compact star properties with nuclear saturation parameters,"A set of hadronic equations of state (EoSs) derived from relativistic density
+functional theory and constrained by terrestrial experiments, astrophysical
+observations, in particular by the GW170817 event, and chiral effective field
+theory ($\chi$EFT) of neutron matter is used to explore the sensitivity of the
+EoS parameterization on the few nuclear matter characteristics defined at the
+saturation density. We find that the gross properties of compact stars are most
+sensitive to the isoscalar skewness coefficient $Q_{\text{sat}}$ and the
+isovector slope coefficient $L_{\text{sym}}$ around saturation density, since
+the higher order coefficients, such as $K_{\text{sym}}$, are fixed by our
+model. More specifically, (i) among these $Q_{\text{sat}}$ is the dominant
+parameter controlling both the maximum mass and the radii of compact stars
+while $L_{\rm sym}$ is constrained somewhat by $\chi$EFT of neutron matter;
+(ii) massive enough ($M\sim 2.0~M_{\odot})$ compact stars featuring both
+hyperons and $\Delta$ resonances can be obtained if the value of
+$Q_{\text{sat}}$ is large enough; (iii) the emergence of $\Delta$'s reduces the
+radius of a canonical mass ($M\sim 1.4~M_{\odot})$ compact star thus easing the
+tension between the predictions of the relativistic density functionals and the
+inferences from the X-ray observation of nearby isolated neutron stars.",1903.06057v2
+2019-04-15,Time evolution of entanglement entropy of moving mirrors influenced by strongly coupled quantum critical fields,"The evolution of the Von Neumann entanglement entropy of a $n$-dimensional
+mirror influenced by the strongly coupled $d$-dimensional quantum critical
+fields with a dynamic exponent $z$ is studied by the holographic approach. The
+dual description is a $n+1$-dimensional probe brane moving in the
+$d+1$-dimensional asymptotic Lifshitz geometry ended at $r=r_b$, which plays a
+role as the UV energy cutoff. Using the holographic influence functional
+method, we find that in the linear response region, by introducing a harmonic
+trap for the mirror, which serves as a IR energy cutoff, the Von Neumann
+entropy at late times will saturate by a power-law in time for generic values
+of $z$ and $n$. The saturated value and the relaxation rate depend on the
+parameter $\alpha\equiv 1+(n+2)/z$, which is restricted to $1<\alpha <3$ but
+$\alpha \ne 2$. We find that the saturated values of the entropy are
+qualitatively different for the theories with $1<\alpha<2$ and $2<\alpha<3$.
+Additionally, the power law relaxation follows the rate $\propto
+t^{-2\alpha-1}$. This probe brane approach provides an alternative way to study
+the time evolution of the entanglement entropy in the linear response region
+that shows the similar power-law relaxation behavior as in the studies of
+entanglement entropies based on Ryu-Takayanagi conjecture. We also compare our
+results with quantum Brownian motion in a bath of relativistic free fields.",1904.06831v2
+2019-04-29,Probing chiral interactions up to next-to-next-to-next-to-leading order in medium-mass nuclei,"We study ground-state energies and charge radii of closed-shell medium-mass
+nuclei based on novel chiral nucleon-nucleon (NN) and three-nucleon (3N)
+interactions, with a focus on exploring the connections between finite nuclei
+and nuclear matter. To this end, we perform in-medium similarity
+renormalization group (IM-SRG) calculations based on chiral interactions at
+next-to-leading order (NLO), N$^2$LO, and N$^3$LO, where the 3N interactions at
+N$^2$LO and N$^3$LO are fit to the empirical saturation point of nuclear matter
+and to the triton binding energy. Our results for energies and radii at N$^2$LO
+and N$^3$LO overlap within uncertainties, and the cutoff variation of the
+interactions is within the EFT uncertainty band. We find underbound
+ground-state energies, as expected from the comparison to the empirical
+saturation point. The radii are systematically too large, but the agreement
+with experiment is better. We further explore variations of the 3N couplings to
+test their sensitivity in nuclei. While nuclear matter at saturation density is
+quite sensitive to the 3N couplings, we find a considerably weaker dependence
+in medium-mass nuclei. In addition, we explore a consistent momentum-space SRG
+evolution of these NN and 3N interactions, exhibiting improved many-body
+convergence. For the SRG-evolved interactions, the sensitivity to the 3N
+couplings is found to be stronger in medium-mass nuclei.",1904.12611v2
+2019-05-15,Nb$_x$Ti$_{1-x}$N low timing jitter single-photon detectors with unity internal efficiency at 1550 nm and 2.5 K,"The requirements in quantum optics experiments for high single photon
+detection efficiency, low timing jitter, low dark count rate and short dead
+time have been fulfilled with the development of superconducting nanowire
+single photon detectors. Although they offer a detection efficiency above 90%,
+achieving a high time resolution in devices made of amorphous materials is a
+challenge, particularly at temperatures above 0.8 K. Devices made from niobium
+nitride and niobium titanium nitride allow to reach the best timing jitter, but
+in turn have stronger requirements in terms of film quality to achieve a high
+efficiency. Here we take advantage of the flexibility of reactive co-sputter
+deposition to tailor the composition of NbxTi1-xN superconducting films, and
+show that a Nb fraction of x = 0.62 allows for the fabrication of detectors
+from films as thick as 9 nm and covering an active area of 20 {\mu}m, with a
+wide detection saturation plateau at telecom wavelengths and in particular at
+1550 nm. This is a signature of an internal detection efficiency saturation,
+achieved while maintaining the high time resolution associated with NbTiN and
+operation at 2.5K. With our optimized recipe, we reliably fabricated detectors
+with high critical current densities reaching a saturation plateau at 1550 nm
+with 80% system detection efficiency, and with a FWHM timing jitter as low as
+19.47 ps.",1905.06091v1
+2019-05-21,Time resolution and dynamic range of field effect transistor based terahertz detectors,"We studied time resolution and response power dependence of three terahertz
+detectors based on significantly different types of field effect transistors.
+We analyzed the photoresponse of custom-made Si junctionless FETs, Si MOSFETs
+and GaAs-based high electron mobility transistors detectors. Applying
+monochromatic radiation of high power, pulsed, line-tunable molecular THz
+laser, which operated at frequencies in the range from 0.6-3.3 THz, we
+demonstrated that all these detectors have at least nanosecond response time.
+We showed that detectors yield a linear response in a wide range of radiation
+power. At high powers the response saturates varying with radiation power P as
+$U = R_0 P/(1+P/P_s)$, where $R_0$ is the low power responsivity, $P_s$ is the
+saturation power. We demonstrated that the linear part response decreases with
+radiation frequency increase as $R_0 \propto f^{-3}$, whereas the power at
+which signal saturates increases as $P_s \propto f^3$. We discussed the
+observed dependences in the framework of the Dyakonov-Shur mechanism and
+detector-antenna impedance matching. Our study showed that FET transistors can
+be used as ultrafast room temperature detectors of THz radiation and that their
+dynamic range extends over many orders of magnitude of power of incoming THz
+radiation. Therefore, when embedded with current driven read out electronics
+they are very well adopted for operation with high power pulsed sources.",1905.08602v1
+2019-05-22,Short echo time relaxation-enhanced MR spectroscopy reveals broad downfield resonances,"Purpose: Most MR spectroscopy (MRS) pulse sequences rely on broadband
+excitation with water saturation and typically focus on upfield signals. By
+contrast, the downfield spectrum, which contains many potentially useful
+resonances, is typically not targeted because conventional water-suppressed
+techniques indirectly saturate the labile protons through exchange.
+Relaxation-enhanced MRS (RE-MRS) uses frequency-selective excitation while
+actively avoiding bulk water perturbation, thereby enabling high-quality
+downfield spectroscopy. However, RE-MRS typically requires very long (typically
+>40 ms) echo times (TEs) due to its localization module, which inevitably
+decreases sensitivity and filters shorter T2 components. Here, we overcome this
+limitation by combining RE-MRS and image selected in vivo spectroscopy (ISIS)
+localization, abbreviated iRE-MRS, which in turn allows very short TEs (5 ms
+using our hardware).
+  Methods: Experiments were performed in vitro for validation as well as and in
+in vivo rat brains at 9.4T.
+  Results: The new iRE-MRS methodology was validated in phantoms where good
+performance was noted. When the downfield spectrum was investigated at short
+TEs in in vivo rat brains, iRE-MRS provided very high sensitivity; the ensuing
+downfield spectra encompassed numerous broad peaks, as well as a broad
+baseline. All downfield spectral peaks were highly attenuated by increasing TEs
+as well as by applying water saturation, although to different extent. The
+signal ratios also varied between TEs, suggesting that exchange rates are
+different among the downfield signals.
+  Conclusions: Short-TE iRE 1H downfield MRS opens new directions in the
+investigation of in vivo downfield metabolites and their role on healthy and
+disease processes.",1905.09158v1
+2019-06-17,Wrist02 -- Reliable Peripheral Oxygen Saturation Readings from Wrist-Worn Pulse Oximeters,"Peripheral blood oxygen saturation Sp02 is a vital measure in healthcare.
+Modern off-the-shelf wrist-worn devices, such as the Apple Watch, FitBit, and
+Samsung Gear, have an onboard sensor called a pulse oximeter. While pulse
+oximeters are capable of measuring both Sp02 and heart rate, current wrist-worn
+devices use them only to determine heart rate, as Sp02 measurements collected
+from the wrist are believed to be inaccurate. Enabling oxygen saturation
+monitoring on wearable devices would make these devices tremendously more
+useful for health monitoring and open up new avenues of research. To the best
+of our knowledge, we present the first study of the reliability of Sp02 sensing
+from the wrist. Using a custom-built wrist-worn pulse oximeter, we find that
+existing algorithms designed for fingertip sensing are a poor match for this
+setting, and can lead to over 90% of readings being inaccurate and unusable. We
+further show that sensor placement and skin tone have a substantial effect on
+the measurement error, and must be considered when designing wrist-worn Sp02
+sensors and measurement algorithms. Based on our findings, we propose
+\codename, an alternative approach for reliable Sp02 sensing. By selectively
+pruning data, \codename achieves an order of magnitude reduction in error
+compared to existing algorithms, while still providing sufficiently frequent
+readings for continuous health monitoring.",1906.07545v1
+2019-09-24,"Saturations of Subalgebras, SAGBI Bases, and U-invariants","Given a polynomial ring $P$ over a field $K$, an element $g \in P$, and a
+$K$-subalgebra $S$ of $P$, we deal with the problem of saturating $S$ with
+respect to $g$, i.e. computing $Sat_g(S) = S[g, g^{-1}]\cap P$. In the general
+case we describe a procedure/algorithm to compute a set of generators for
+$Sat_g(S)$ which terminates if and only if it is finitely generated.
+  Then we consider the more interesting case when $S$ is graded. In particular,
+if $S$ is graded by a positive matrix $W$ and $g$ is an indeterminate, we show
+that if we choose a term ordering $\sigma$ of $g$-DegRev type compatible with
+$W$, then the two operations of computing a $\sigma$-SAGBI basis of $S$ and
+saturating $S$ with respect to $g$ commute.
+  This fact opens the doors to nice algorithms for the computation of
+$Sat_g(S)$. In particular, under special assumptions on the grading one can use
+the truncation of a $\sigma$-SAGBI basis and get the desired result.
+  Notably, this technique can be applied to the problem of directly computing
+some $U$-invariants, classically called semi-invariants, even in the case that
+$K$ is not the field of complex numbers.",1909.10901v3
+2019-11-11,Extracting many-body correlators of saturated gluons with precision from inclusive photon+dijet final states in deeply inelastic scattering,"We highlight the principal results of a computation in the Color Glass
+Condensate effective field theory (CGC EFT) of the next-to-leading order (NLO)
+impact factor for inclusive photon+dijet production at Bjorken $x_{\rm Bj} \ll
+1$ in deeply inelastic electron-nucleus (e+A DIS) collisions. When combined
+with extant results for next-to-leading log $x_{\rm Bj}$ JIMWLK renormalization
+group (RG) evolution of gauge invariant two-point (""dipole"") and four-point
+(""quadrupole"") correlators of light-like Wilson lines, the inclusive
+photon+dijet e+A DIS cross-section can be determined to $\sim 10$\% accuracy.
+Our computation simultaneously provides the ingredients to compute fully
+inclusive DIS, inclusive photon, inclusive dijet and inclusive photon+jet
+channels to the same accuracy. This makes feasible quantitative extraction of
+many-body correlators of saturated gluons and precise determination of the
+saturation scale $Q_{S,A}(x_{\rm Bj})$ at a future Electron-Ion Collider. An
+interesting feature of our NLO result is the structure of the violation of the
+soft gluon theorem in the Regge limit. Another is the appearance in gluon
+emission of time-like non-global logs which also satisfy JIMWLK RG evolution.",1911.04519v2
+2020-02-09,"Growth, saturation and collapse of laser-driven plasma density gratings","The plasma density grating induced by intersecting intense laser pulses can
+be utilized as an optical compressors, polarizers, waveplates and photonic
+crystals for the manipulation of ultra-high-power laser pulses. However, the
+formation and evolution of the plasma density grating are still not fully
+understood as linear models are adopted to describe them usually. In this
+paper, two nonlinear theoretical models are presented to study the formation
+process of the plasma density grating. In the first model, a nonlinear
+analytical solution based on the fluid equations is presented while in the
+second model a particle-mesh method is adopted to investigate the kinetic
+effects. It is found that both models can describe the plasma density grating
+formation at different stages, well beyond the linear growth stage. More
+importantly, the second model can reproduce the phenomenon of ""ion
+wave-breaking"" of plasma density grating, which eventually induces the
+saturation of plasma density grating. Using the second model, the saturation
+time of the plasma density grating is obtained as a function of laser intensity
+and plasma density, which can be applied to estimate the lifetime of the plasma
+density grating in experiments. The results from these two nonlinear models are
+verified using particle-in-cell simulations.",2002.03340v3
+2020-02-27,Scaling exponents saturate in three-dimensional isotropic turbulence,"From a database of direct numerical simulations of homogeneous and isotropic
+turbulence, generated in periodic boxes of various sizes, we extract the
+spherically symmetric part of moments of velocity increments and first verify
+the following (somewhat contested) results: the $4/5$-ths law holds in an
+intermediate range of scales and that the second order exponent over the same
+range of scales is {\it{anomalous}}, departing from the self-similar value of
+$2/3$ and approaching a constant of $0.72$ at high Reynolds numbers. We compare
+with some typical theories the dependence of longitudinal exponents as well as
+their derivatives with respect to the moment order $n$, and estimate the most
+probable value of the H\""older exponent. We demonstrate that the transverse
+scaling exponents saturate for large $n$, and trace this trend to the presence
+of large localized jumps in the signal. The saturation value of about $2$ at
+the highest Reynolds number suggests, when interpreted in the spirit of
+fractals, the presence of vortex sheets rather than more complex singularities.
+In general, the scaling concept in hydrodynamic turbulence appears to be more
+complex than even the multifractal description.",2002.11900v2
+2020-03-27,Fakernet -- small and fast FPGA-based TCP and UDP communication,"A common theme of data acquisition systems is the transport of data from
+digitising front-end modules to stable storage and online analysis. A good
+choice today is to base this on the ubiquitous, commercially and cheaply
+available Ethernet technology. A firmware building block to turn already the
+FPGA of front-end electronics into a TCP data source and UDP control interface
+using a data-flow architecture is presented. The overall performance targets
+are to be able to saturate a 1 Gbps network link with outbound data, while
+using few FPGA resources. The goal is to replace the use of custom data buses
+and protocols with ordinary Ethernet equipment. These objectives are achieved
+by being just-enough conforming, such that no special drivers are needed in the
+PC equipment interfacing with the here presented Fakernet system. An important
+design choice is to handle all packet-data internally as 16-bit words, thus
+reducing the clock-speed requirements. An advantageous circumstance is that
+even at 1 Gbps speeds, for local network segments, the round-trip times are
+usually well below 500 microseconds. Thus, less than 50 kiB of unacknowledged
+data needs to be in-flight, allowing to saturate a network link without TCP
+window scaling. The Fakernet system has so far been shown to saturate a 100
+Mbps link at 11.7 MB/s of TCP output data, and able to do 32-bit control
+register accesses at over 450 kword/s.",2003.12527v1
+2020-03-27,Lensing Mechanism Meets Small-$x$ Physics: Single Transverse Spin Asymmetry in $p^{\uparrow}+p$ and $p^{\uparrow}+A$ Collisions,"We calculate the single transverse spin asymmetry (STSA) in polarized
+proton-proton ($p^{\uparrow}+p$) and polarized proton-nucleus
+($p^{\uparrow}+A$) collisions ($A_N$) generated by a partonic lensing
+mechanism. The polarized proton is considered in the quark-diquark model while
+its interaction with the unpolarized target is calculated using the
+small-$x$/saturation approach, which includes multiple rescatterings and
+small-$x$ evolution. The phase required for the asymmetry is caused by a
+final-state gluon exchange between the quark and diquark, as is standard in the
+lensing mechanism of Brodsky, Hwang and Schmidt. Our calculation combines the
+lensing mechanism with small-$x$ physics in the saturation framework. The
+expression we obtain for the asymmetry $A_N$ of the produced quarks has the
+following properties: (i) The asymmetry is generated by the dominant elastic
+scattering contribution and $1/N_c^2$ suppressed inelastic contribution (with
+$N_c$ the number of quark colors); (ii) The asymmetry grows or oscillates with
+the produced quark's transverse momentum $p_T$ until the momentum reaches the
+saturation scale $Q_s$, and then only falls off as $1/p_T$ for larger momenta;
+(iii) The asymmetry decreases with increasing atomic number $A$ of the target
+for $p_T$ below or near $Q_s$, but is independent of $A$ for $p_T$
+significantly above $Q_s$. We discuss how these properties may be qualitatively
+consistent with the data on $A_N$ published by the PHENIX collaboration and
+with the preliminary data on $A_N$ reported by the STAR collaboration.",2003.12650v2
+2020-04-30,Non-local Entanglement and Fast Scrambling in De-Sitter Holography,"We study holographic entanglement and information scrambling in de-Sitter
+(dS) space in the context of the DS/dS correspondence. We find that our
+previously identified non-local entanglement structure of dS vacua can be
+extended out of the time-reflection symmetric slice. We extend the geometry to
+a two-sided configuration and calculate the zero-time mutual information
+between two intervals on different sides when there is a localized shock wave
+in the bulk. Interestingly, we find that the information scrambling time
+saturates the fast scrambler bound proposed by Sekino and Susskind and that the
+shock wave renders a wormhole to be traversable. Furthermore, we calculate a
+two-sided out-of-time-ordered correlator (OTOC) in the late time regime and we
+see that, before scrambling, it exponentially grows with an exponent whose
+value saturates the maximal bound of chaos proposed by Maldacena, Shenker and
+Stanford. At the end, we provide an explanation why the exponential growing of
+the late-time OTOC with the maximal bound of chaos saturated and the
+traversability of the wormhole are simple results of the non-local entanglement
+structure and point out that this is a realization of the ER=EPR proposal.",2005.00021v4
+2020-05-29,Core swelling in spherical nuclei: An indication of the saturation of nuclear density,"Background: Nuclear radius is one of the most important and basic properties
+of atomic nuclei and its evolution is closely related to the saturation of the
+nuclear density in the internal region but the systematics of the nuclear radii
+for the neutron-rich unstable nuclei is not well known.
+  Purpose: Motivated by the recent interaction cross section measurement which
+indicates the 48Ca core swelling in the neutron-rich Ca isotopes, we explore
+the mechanism of the enhancement of the neutron and proton radii for spherical
+nuclei.
+  Methods: Microscopic Hartree-Fock calculations with three sets of Skyrme-type
+effective interactions are performed for the neutron-rich Ca, Ni and Sn
+isotopes. The total reaction cross sections for the Ca isotopes are evaluated
+with the Glauber model to compare them with the recent cross section data.
+  Results: We obtain good agreement with the measured cross sections and charge
+radii. The neutron and proton radii of the various ""core"" configurations are
+extracted from the full Hartree-Fock calculation and discuss the core swelling
+mechanism.
+  Conclusions: The core swelling phenomena occur depending on the properties of
+the occupying valence single-neutron states to minimize the energy loss that
+comes from the saturation of the densities in the internal region, which
+appears to be prominent in light nuclei such as Ca isotopes.",2005.14352v1
+2020-06-23,Invariants ideals in Leavitt Path algebras,"It is known that the ideals of a Leavitt path algebra $L_K(E)$ generated by
+$\Pl(E)$, by $\Pc(E)$ or by $\Pec(E)$ are invariant under isomorphism. Though
+the ideal generated by $\Pb(E)$ is not invariant we find its \lq\lq
+natural\rq\rq\ replacement (which is indeed invariant): the one generated by
+the vertices of $\Pbp$ (vertices with pure infinite bifurcations). We also give
+some procedures to construct invariant ideals from previous known invariant
+ideals. One of these procedures involves topology, so we introduce the $\tops$
+topology and relate it to annihilators in the algebraic counterpart of the
+work. To be more explicit: if $H$ is a hereditary saturated subset of vertices
+providing an invariant ideal, its exterior $\ext(H)$ in the $\tops$ topology of
+$E^0$ generates a new invariant ideal. The other constructor of invariant
+ideals is more categorical in nature. Some hereditary sets can be seen as
+functors from graphs to sets (for instance $\Pl$, etc). Thus a second method
+emerges from the possibility of applying the induced functor to the quotient
+graph. The easiest example is the known socle chain $\soc^{(1)}(\
+)\subset\soc^{(2)}(\ )\subset\cdots$ all of which are proved to be invariant.
+We generalize this idea to any hereditary and saturated invariant functor.
+Finally we investigate a kind of composition of hereditary and saturated
+functors which is associative.",2006.12876v1
+2020-07-27,EUV irradiation of exoplanet atmospheres occurs on Gyr timescales,"Exoplanet atmospheres are known to be vulnerable to mass loss through
+irradiation by stellar X-ray and extreme-ultraviolet emission. We investigate
+how this high-energy irradiation varies with time by combining an empirical
+relation describing stellar X-ray emission with a second relation describing
+the ratio of Solar X-ray to extreme-ultraviolet emission. In contrast to
+assumptions commonly made when modelling atmospheric escape, we find that the
+decline in stellar extreme-ultraviolet emission is much slower than in X-rays,
+and that the total extreme-ultraviolet irradiation of planetary atmospheres is
+dominated by emission after the saturated phase of high energy emission (which
+lasts around 100 Myr after the formation of the star). The extreme-ultraviolet
+spectrum also becomes much softer during this slow decline. Furthermore, we
+find that the total combined X-ray and extreme-ultraviolet emission of stars
+also occurs mostly after this saturated phase. Our results suggest that models
+of atmospheric escape that focus on the saturated phase of high-energy emission
+are over-simplified, and when considering the evolution of planetary
+atmospheres it is necessary to follow EUV-driven escape on Gyr timescales. This
+may make it more difficult to use stellar age to separate the effects of
+photoevaporation and core-powered mass-loss when considering the origin the
+planet radius valley.",2007.13731v2
+2020-08-22,Gravitational wave asteroseismology for low-mass neutron stars,"The fundamental ($f$-) mode gravitational waves from cold low-mass neutron
+stars are systematically studied with various equations of state (EOSs)
+characterized by the nuclear saturation parameters, especially focusing on the
+phenomena of the avoided crossing with the first pressure ($p_1$-) mode. We
+find that the $f$-mode frequency and the average density for the neutron star
+at the avoided crossing can be expressed as a function of the parameter,
+$\eta$, which is the specific combination of the nuclear saturation parameters.
+Owing to these relations, we can derive the empirical formula expressing the
+$f$-mode frequency for a low-mass neutron star, whose central density is larger
+than that for the neutron star at the avoided crossing, as a function of $\eta$
+and the square root of the stellar average density, $x$. On the other hand, we
+also derive the empirical formula expressing the $f$-mode frequency for a
+neutron star, whose central density is less than that for the neutron star at
+the avoided crossing, as a function of $x$ independently of the adopted EOS.
+Furthermore, adopting the empirical formula of $x$ as a function of $\eta$ and
+$u_c$, which is the ratio of the stellar central density to the saturation
+density, we can also rewrite our empirical formula for the $f$-mode frequency
+to a function of $\eta$ and $u_c$. So, by observing the $f$-mode gravitational
+wave from a low-mass neutron star, whose mass or gravitational redshift is
+known, one could evaluate the values of $\eta$ and $u_c$, which enables us to
+severely constrain the EOS for neutron star matter.",2008.09839v1
+2020-09-24,Large magnetoresistance in the iron-free pnictide superconductor LaRu$_2$P$_2$,"The magnetoresistance of iron pnictide superconductors is often dominated by
+electron-electron correlations and deviates from the H$^2$ or saturating
+behaviors expected for uncorrelated metals. Contrary to similar Fe-based
+pnictide systems, the superconductor LaRu$_2$P$_2$ (T$_c$ = 4 K) shows no
+enhancement of electron-electron correlations. Here we report a non-saturating
+magnetoresistance deviating from the H$^2$ or saturating behaviors in
+LaRu$_2$P$_2$. We have grown and characterized high quality single crystals of
+LaRu$_2$P$_2$ and measured a magnetoresistance following H$^{1.3}$ up to 22 T.
+We discuss our result by comparing the bandstructure of LaRu$_2$P$_2$ with Fe
+based pnictide superconductors. The different orbital structures of Fe and Ru
+leads to a 3D Fermi surface with negligible bandwidth renormalization in
+LaRu$_2$P$_2$, that contains a large open sheet over the whole Brillouin zone.
+We show that the large magnetoresistance in LaRu$_2$P$_2$ is unrelated to the
+one obtained in materials with strong electron-electron correlations and that
+it is compatible instead with conduction due to open orbits on the rather
+complex Fermi surface structure of LaRu$_2$P$_2$.",2009.11585v1
+2020-11-03,Growth of respiratory droplets in cold and humid air,"The ambient conditions surrounding liquid droplets determine their growth or
+shrinkage. However, the precise fate of a liquid droplet expelled from a
+respiratory puff as dictated by its surroundings and the puff itself has not
+yet been fully quantified. From the view of airborne disease transmission, such
+as SARS-CoV-2, knowledge of such dependencies are critical. Here we employ
+direct numerical simulations (DNS) of a turbulent respiratory vapour puff and
+account for the mass and temperature exchange with respiratory droplets and
+aerosols. In particular, we investigate how droplets respond to different
+ambient temperatures and relative humidity (RH) by tracking their Lagrangian
+statistics. We reveal and quantify that in cold and humid environments, as
+there the respiratory puff is supersaturated, expelled droplets can first
+experience significant growth, and only later followed by shrinkage, in
+contrast to the monotonic shrinkage of droplets as expected from the classical
+view by William F. Wells (1934). Indeed, cold and humid environments diminish
+the ability of air to hold water vapour, thus causing the respiratory vapour
+puff to super-saturate. Consequently, the super-saturated vapour field drives
+the growth of droplets that are caught and transported within the humid puff.
+To analytically predict the likelihood for droplet growth, we propose a model
+for the axial RH based on the assumption of a quasi-stationary jet. Our model
+correctly predicts super-saturated RH conditions and is in good quantitative
+agreement with our DNS. Our results culminate in a temperature-RH map that can
+be employed as an indicator for droplet growth or shrinkage.",2011.01515v1
+2020-11-17,Collapse and cavitation during drying of water-saturated PDMS sponges with closed porosity,"In this paper, we study the drying of water-saturated porous
+polydimethylsiloxane (PDMS) elastomers with closed porosity in which the
+evaporation of water is possible only via the diffusion across the PDMS.
+Starting from water/PDMS emulsions, we fabricate soft macroporous samples with
+different pore diameter distributions and average diameters ranging from 10 to
+300 $\mu$m. In these materials, the drying may lead either to a collapsed state
+with low porosity or to the cavitation and reopening of a fraction of the
+pores. Using optical microscopy and porosity measurements, we showed the
+importance of the pore diameters and interactions on the result of drying. At
+pore diameters lower than 30 $\mu$m, the majority of pores remain collapsed. We
+attribute the permanence of the collapse of most small pores to a low
+probability of cavitation and to the adhesion of the pore walls. Pores with
+diameters larger than 100 $\mu$m tend to reopen after the water they contain
+cavitates. The behavior of pores with diameters ranging from 30 to 100 $\mu$m
+depends on the porosity and drying temperature. We also visualize collective
+cavitation upon drying of sponges initially saturated with a sodium chloride
+solution. In this case, the cavitation in the largest pores leads to reopening
+of small pores in a neighboring zone of the sample. To our knowledge, our
+results present the first experimental proof of the pore-size-dependent and
+cooperative nature of the response of soft sponges with closed porosity to
+drying.",2011.08570v1
+2021-01-08,Dynamics of droplets under electrowetting effect with voltages exceeding the contact angle saturation threshold,"Electrowetting-on-dielectric (EWOD) is a powerful tool in many
+droplet-manipulation applications with a notorious weakness caused by
+contact-angle saturation (CAS), a phenomenon limiting the equilibrium contact
+angle of an EWOD-actuated droplet at high applied voltage. In this paper, we
+study the spreading behaviours of droplets on EWOD substrates with the range of
+applied voltage exceeding the saturation limit. We experimentally find that at
+the initial stage of spreading, the driving force at the contact line still
+follows the Young-Lippmann law even if the applied voltage is higher than the
+CAS voltage. We then theoretically establish the relation between the initial
+contact-line velocity and the applied voltage using the force balance at the
+contact line. We also find that the amplitude of capillary waves on the droplet
+surface generated by the contact-line's initial motion increases with the
+applied voltage. We provide a working framework utilising EWOD with voltages
+beyond CAS by characterising the capillary waves formed on the droplet surface
+and their self-similar behaviours. We finally propose a theoretical model of
+the wave profiles taking into account the viscous effects and verify this model
+experimentally. Our results provide avenues to utilise the EWOD effect with
+voltages beyond CAS threshold and have strong bearing on emerging applications
+such as digital microfluidic and ink-jet printing.",2101.02821v3
+2021-01-13,Analytic quasi-steady evolution of a marginally unstable wave in the presence of drag and scattering,"The 1D bump-on-tail problem is studied in order to determine the influence of
+drag on quasi-steady solutions near marginal stability ($1-\gamma_d/\gamma_L\ll
+1$) when effective collisions are much larger than the instability growth rate
+($\nu \gg \gamma$). In this common tokamak regime, it is rigorously shown that
+the paradigmatic Berk-Breizman cubic equation for the nonlinear mode evolution
+reduces to a much simpler differential equation, dubbed the time-local cubic
+equation, which can be solved directly. It is found that in addition to
+increasing the saturation amplitude, drag introduces a shift in the apparent
+oscillation frequency by modulating the saturated wave envelope. Excellent
+agreement is found between the analytic solution for the mode evolution and
+both the numerically integrated Berk-Breizman cubic equation and fully
+nonlinear 1D Vlasov simulations. Experimentally isolating the contribution of
+drag to the saturated mode amplitude for verification purposes is explored but
+complicated by the reality that the amount of drag can not be varied
+independently of other key parameters in realistic scenarios. While the effect
+of drag is modest when the ratio of drag to scattering $\alpha/\nu$ is very
+small, it can become substantial when $\alpha/\nu \gtrsim 0.5$, suggesting that
+drag should be accounted for in quantitative models of fast-ion-driven
+instabilities in fusion plasmas.",2101.04875v1
+2021-02-09,Chain ordering of phospholipids in membranes containing cholesterol: What matters?,"Cholesterol (CHOL) drives lipid segregation and is thus a key player for the
+formation of lipid rafts and followingly for the ability of a cell to, e.g.,
+enable selective agglomeration of proteins. The lipid segregation is driven by
+cholesterol's affinity for saturated lipids, which stands directly in relation
+to the ability of cholesterol to order the individual phospholipid (PL) acyl
+chains. In this work, Molecular Dynamics simulations of DPPC
+(Dipalmitoylphosphatidylcholine, saturated lipid) and DLiPC
+(Dilineoylphosphatidylcholine, unsaturated lipid) mixtures with cholesterol are
+used to elucidate the underlying mechanisms of the cholesterol ordering effect.
+To this end, all enthalpic contributions, experienced by the PL molecules, are
+recorded as a function of the PL's acyl chain order. This involves, the PL-PL,
+the PL-cholesterol interaction, the interaction of the PLs with water, and the
+interleaflet interaction. This systematic analysis allows one to unravel
+differences of saturated and unsaturated lipids in terms of the different
+interaction factors. It turns out that cholesterol's impact on chain ordering
+stems not only from direct interactions with the PLs but is also indirectly
+present in the other energy contributions. Furthermore, the analysis sheds
+light on the relevance of the entropic contributions, related to the degrees of
+freedom of the acyl chain.",2102.04996v3
+2021-04-05,Auxiliary Function Approach for Determining Symmetry Energy at Supra-saturation Densities,"Nuclear symmetry energy $E_{\rm{sym}}(\rho)$ at density $\rho$ is normally
+expanded or simply parameterized as a function of $\chi=(\rho-\rho_0)/3\rho_0$
+in the form of $E_{\rm{sym}}(\rho)\approx
+S+L\chi+2^{-1}K_{\rm{sym}}\chi^2+6^{-1}J_{\rm{sym}}\chi^3+\cdots$ using its
+magnitude $S$, slope $L $, curvature $K_{\rm{sym}}$ and skewness $J_{\rm{sym}}$
+at the saturation density $\rho_0$ of nuclear matter. Much progress has been
+made in recent years in constraining especially the $S$ and $L$ parameters
+using various terrestrial experiments and astrophysical observations. However,
+such kind of expansions/parameterizations do not converge at supra-saturation
+densities where $\chi$ is not small enough, hindering an accurate determination
+of high-density $E_{\rm{sym}}(\rho)$ even if its characteristic parameters at
+$\rho_0$ are all well determined by experiments/observations. By expanding the
+$E_{\rm{sym}}(\rho)$ in terms of a properly chosen auxiliary function
+$\Pi_{\rm{sym}}(\chi,\Theta_{\rm{sym}})$ with a parameter $\Theta_{\rm{sym}}$
+fixed accurately by an experimental $E_{\rm{sym}}(\rho_{\rm{r}})$ value at a
+reference density $\rho_{\rm{r}}$, we show that the shortcomings of the
+$\chi$-expansion can be completely removed or significantly reduced in
+determining the high-density behavior of $E_{\rm{sym}}(\rho)$. In particular,
+using two significantly different auxiliary functions, we show that the new
+approach effectively incorporates higher $\chi$-order contributions and
+converges to the same $E_{\rm{sym}}(\rho)$ much faster than the conventional
+$\chi$-expansion at densities $\lesssim3\rho_0$. Several quantitative
+demonstrations using Monte Carlo simulations are given.",2104.02185v2
+2021-04-06,Bounded Inputs Total Energy Shaping for Mechanical Systems,"Designing control systems with bounded input is a practical consideration
+since realizable physical systems are limited by the saturation of actuators.
+The actuators' saturation degrades the performance of the control system, and
+in extreme cases, the stability of the closed-loop system may be lost. However,
+actuator saturation is typically neglected in the design of control systems,
+with compensation being made in the form of over-designing the actuator or by
+post-analyzing the resulting system to ensure acceptable performance. The
+bounded input control of fully actuated systems has been investigated in
+multiple studies, but it is not generalized for under actuated mechanical
+systems. This article proposes a systematic framework for finding the upper
+bound of control effort in underactuated systems, based on interconnection and
+the damping assignment passivity based control (IDA-PBC) approach. The proposed
+method also offers design variables for the control law to be tuned,
+considering the actuator's limit. The major difficulty in finding the control
+input upper bounds is the velocity dependent kinetic energy related terms.
+Thus, the upper bound of velocity is computed using a suitable Lyapunov
+candidate as a function of closed-loop system parameters. The validity and
+application of the proposed method are investigated in detail through two
+benchmark systems.",2104.02337v1
+2021-04-07,Rotation-Activity Relation of Ca II and Mg I Infrared Emission Lines of Young Stars,"To reveal the detail of the internal structure, the relationship between
+chromospheric activity and the Rossby number, N_R (= rotational period P /
+convective turnover time tau_c), has been extensively examined for
+main-sequence stars. The goal of our work is to apply the same methods to
+pre-main-sequence (PMS) stars and identify the appropriate model of tau_c for
+them. Yamashita et al. (2020) investigated the relationship between N_R and
+strengths of the Ca II infrared triplet (IRT; lambda 8498, 8542, 8662 A)
+emission lines of 60 PMS stars. Their equivalent widths are converted into the
+emission line to stellar bolometric luminosity ratio (R'). The 54 PMS stars
+have N_R < 10^{-1.0} and show R' \sim 10^{-4.2} as large as the maximum R' of
+the zero-age main-sequence (ZAMS) stars. However, because all R' was saturated
+against N_R, it was not possible to estimate the appropriate tau_c model for
+the PMS stars. We noticed that Mg I emission lines at 8808 A is an optically
+thin chromospheric line, appropriate for determination of the adequate tau_c
+for PMS stars. Using the archive data of the Anglo-Australian Telescope
+(AAT)/the University College London Echelle Spectrograph (UCLES), we
+investigated the Mg I line of 52 ZAMS stars. After subtracting photospheric
+absorption component, the Mg I line is detected as an emission line in 45 ZAMS
+stars, whose R' is between 10^{-5.9} and 10^{-4.1}. The Mg I line is not
+saturated yet in ""the saturated regime for the Ca II emission lines"", i.e.
+10^{-1.6} < N_R < 10^{-0.8}. Therefore, the adequate tau_c for PMS stars can be
+determined by measuring of their R' values.",2104.02910v1
+2021-05-04,Deep-learning-based coupled flow-geomechanics surrogate model for CO$_2$ sequestration,"A deep-learning-based surrogate model capable of predicting flow and
+geomechanical responses in CO2 storage operations is presented and applied. The
+3D recurrent R-U-Net model combines deep convolutional and recurrent neural
+networks to capture the spatial distribution and temporal evolution of
+saturation, pressure and surface displacement fields. The method is trained
+using high-fidelity simulation results for 2000 storage-aquifer realizations
+characterized by multi-Gaussian porosity and log-permeability fields. These
+numerical solutions are expensive because the domain that must be considered
+for the coupled problem includes not only the storage aquifer but also a
+surrounding region, overburden and bedrock. The surrogate model is trained to
+predict the 3D CO2 saturation and pressure fields in the storage aquifer, and
+2D displacement maps at the Earth's surface. Detailed comparisons between
+surrogate model and full-order simulation results for new (test-case)
+storage-aquifer realizations are presented. The saturation, pressure and
+surface displacement fields provided by the surrogate model display a high
+degree of accuracy, both for individual test-case realizations and for ensemble
+statistics. Finally, the the recurrent R-U-Net surrogate model is applied with
+a rejection sampling procedure for data assimilation. Although the observations
+consist of only a small number of surface displacement measurements,
+significant uncertainty reduction in pressure buildup at the top of the storage
+aquifer (caprock) is achieved.",2105.01334v1
+2021-06-01,Symmetry potentials and in-medium nucleon-nucleon cross sections within the Nambu-Jona-Lasinio model in relativistic impulse approximation,"In the relativistic impulse approximation (RIA), we study symmetry potentials
+and in-medium nucleon-nucleon (NN) cross sections with the Nambu-Jona-Lasinio
+(NJL) model that features chiral symmetry. The chiral symmetry that plays a
+fundamental role in the nonperturbative physics in the strong interaction is
+anticipated to add restrictive effects on the symmetry potentials and in-medium
+NN cross sections. For comparison, we also perform the study with the usual
+relativistic mean-field (RMF) model. The numerical results with the NJL and RMF
+models are similar at saturation density and below, since a priori fit was made
+to saturation properties. With the increase of nuclear density, the chiral
+symmetry starts to be restored partially in the NJL model, resulting in the
+explicit fall of the scalar density. In a large energy span, the symmetry
+potential acquires a significant rise for the partial restoration of the chiral
+symmetry, compared to the one with the RMF model. It is found that the
+in-medium NN cross sections in the RIA with the NJL and RMF models both
+increase with the density in the energy region interested in this study,
+whereas those with the NJL model increase sharply as long as a clear chiral
+symmetry restoration takes place. The different tendency of observables in
+density can be transmitted to the different energy dependence in the RIA. The
+NJL model is shown to have characteristic energy-dependent symmetry potentials
+and NN cross sections beyond saturation point, apart from the RMF models.",2106.00429v1
+2021-06-07,Learning to Guide a Saturation-Based Theorem Prover,"Traditional automated theorem provers have relied on manually tuned
+heuristics to guide how they perform proof search. Recently, however, there has
+been a surge of interest in the design of learning mechanisms that can be
+integrated into theorem provers to improve their performance automatically. In
+this work, we introduce TRAIL, a deep learning-based approach to theorem
+proving that characterizes core elements of saturation-based theorem proving
+within a neural framework. TRAIL leverages (a) an effective graph neural
+network for representing logical formulas, (b) a novel neural representation of
+the state of a saturation-based theorem prover in terms of processed clauses
+and available actions, and (c) a novel representation of the inference
+selection process as an attention-based action policy. We show through a
+systematic analysis that these components allow TRAIL to significantly
+outperform previous reinforcement learning-based theorem provers on two
+standard benchmark datasets (up to 36% more theorems proved). In addition, to
+the best of our knowledge, TRAIL is the first reinforcement learning-based
+approach to exceed the performance of a state-of-the-art traditional theorem
+prover on a standard theorem proving benchmark (solving up to 17% more
+problems).",2106.03906v1
+2021-06-28,"A Low Power Threshold, Ultrathin Optical Limiter Based on a Nonlinear Zone Plate","Ultrathin optical limiters are needed to protect light sensitive components
+in miniaturized optical systems. However, it has proven challenging to achieve
+a sufficiently low optical limiting threshold. In this work, we theoretically
+show that an ultrathin optical limiter with low threshold intensity can be
+realized using a nonlinear zone plate. The zone plate is embedded with
+nonlinear saturable absorbing materials that allow the device to focus low
+intensity light, while high intensity light is transmitted as a plane wave
+without a focal spot. Based on this proposed mechanism, we use the
+finite-difference time-domain method to computationally design a zone plate
+embedded with InAs quantum dots as the saturable absorbing material. The device
+has a thickness of just 0.5 $\mu m$ and exhibits good optical limiting behavior
+with a threshold intensity as low as 0.45 kW/$cm^2$, which is several orders of
+magnitude lower than current ultrathin flat-optics-based optical limiters. This
+design can be optimized for different operating wavelengths and threshold
+intensities by using different saturable absorbing materials. Additionally, the
+diameter and focal length of the nonlinear zone plate can be easily adjusted to
+fit different systems and applications. Due to its flexible design, low power
+threshold, and ultrathin thickness, this optical limiting concept may be
+promising for application in miniaturized optical systems.",2106.15025v1
+2021-07-13,Eddy saturation in a reduced two-level model of the atmosphere,"Eddy saturation describes the nonlinear mechanism in geophysical flows
+whereby, when average conditions are considered, direct forcing of the zonal
+flow increases the eddy kinetic energy, while the energy associated with the
+zonal flow does not increase. Here we present a minimal baroclinic model that
+exhibits complete eddy saturation. Starting from Phillips' classical
+quasi-geostrophic two-level model on the beta channel of the mid-latitudes, we
+derive a reduced order model comprising of six ordinary differential equations
+including parameterised eddies. This model features two physically realisable
+steady state solutions, one a purely zonal flow and one where, additionally,
+finite eddy motions are present. As the baroclinic forcing in the form of
+diabatic heating is increased, the zonal solution loses stability and the eddy
+solution becomes attracting. After this bifurcation, the zonal components of
+the solution are independent of the baroclinic forcing, and the excess of heat
+in the low latitudes is efficiently transported northwards by finite eddies, in
+the spirit of baroclinic adjustment.",2107.05864v1
+2021-08-18,Mining for Gluon Saturation at Colliders,"Quantum chromodynamics (QCD) is the theory of strong interactions of quarks
+and gluons collectively called partons, the basic constituents of all nuclear
+matter. Its non-abelian character manifests in nature in the form of two
+remarkable properties: color confinement and asymptotic freedom. At high
+energies, perturbation theory can result in the growth and dominance of very
+gluon densities at small-x. If left uncontrolled, this growth can result in
+gluons eternally growing violating a number of mathematical bounds. The
+resolution to this problem lies by balancing gluon emissions by recombinating
+gluons at high energies : phenomena of gluon saturation. High energy nuclear
+and particle physics experiments have spent the past decades quantifying the
+structure of protons and nuclei in terms of their fundamental constituents
+confirming predicted extraordinary behavior of matter at extreme density and
+pressure conditions. In the process they have also measured seemingly
+unexpected phenomena. We will give a state of the art review of the underlying
+theoretical and experimental tools and measurements pertinent to gluon
+saturation physics. We will argue for the need of high energy
+electron-proton/ion colliders such as the proposed EIC (USA) and LHeC (Europe)
+to consolidate our knowledge of QCD in the small x kinematic domains.",2108.08254v1
+2021-10-12,Streaming Instability with Multiple Dust Species: II. Turbulence and Dust-Gas Dynamics at Nonlinear Saturation,"The streaming instability is a fundamental process that can drive dust-gas
+dynamics and ultimately planetesimal formation in protoplanetary discs. As a
+linear instability, it has been shown that its growth with a distribution of
+dust sizes can be classified into two distinct regimes, fast- and slow-growth,
+depending on the dust-size distribution and the total dust-to-gas density ratio
+$\epsilon$. Using numerical simulations of an unstratified disc, we bring three
+cases in different regimes into nonlinear saturation. We find that the
+saturation states of the two fast-growth cases are similar to its
+single-species counterparts. The one with maximum dimensionless stopping time
+$\tau_\mathrm{s,max}=0.1$ and $\epsilon=2$ drives turbulent vertical dust-gas
+vortices, while the other with $\tau_\mathrm{s,max}=2$ and $\epsilon=0.2$ leads
+to radial traffic jams and filamentary structures of dust particles. The dust
+density distribution for the former is flat in low densities, while the one for
+the latter has a low-end cutoff. By contrast, the one slow-growth case results
+in a virtually quiescent state. Moreover, we find that in the fast-growth
+regime, significant dust segregation by size occurs, with large particles
+moving towards dense regions while small particles remain in the diffuse
+regions, and the mean radial drift of each dust species is appreciably altered
+from the (initial) drag-force equilibrium. The former effect may skew the
+spectral index derived from multi-wavelength observations and change the
+initial size distribution of a pebble cloud for planetesimal formation. The
+latter along with turbulent diffusion may influence the radial transport and
+mixing of solid materials in young protoplanetary discs.",2110.06248v1
+2021-10-20,Selective crystal growth of indium selenide compounds from saturated solutions grown in a selenium vapor,"Indium selenide compounds are promising materials for energy conversion,
+spintronic applications, and chemical sensing. However, it is difficult to grow
+stoichiometric indium selenide crystals due to the high equilibrium selenium
+vapor pressure and the complicated phase equilibrium system of indium selenide
+compounds. In this paper, we apply a novel and convenient crystal growth
+method, in which the saturated solution is grown by the application of a
+selenium vapor. In this method, selenium vapor at a pressure higher than the
+saturated vapor pressure is applied to molten indium, such that the selenium
+continuously dissolves into the indium solution until the solubility at the
+growth temperature is reached; then a slow cooling process results in
+crystallization. The selenium dose is matched to its solubility so that indium
+selenide compounds can be selectively grown just by controlling the temperature
+without the need to consider the chemical ratio in the solution. The pressure
+of the vapor is controlled during the whole growth process so that any
+deviation from a stoichiometric composition in the crystal can be controlled.
+Both InSe and In2Se3 were successfully grown using this method, and we have
+investigated the growth mechanism and found the growth window for each
+compound. This study presents a novel and convenient approach to fabricating
+transitional metal chalcogenides without deficiencies in the chalcogen element.",2110.10345v1
+2021-10-21,The Acoustic Resonant Drag Instability with a Spectrum of Grain Sizes,"We study the linear growth and nonlinear saturation of the ""acoustic Resonant
+Drag Instability"" (RDI) when the dust grains, which drive the instability, have
+a wide, continuous spectrum of different sizes. This physics is generally
+applicable to dusty winds driven by radiation pressure, such as occurs around
+red-giant stars, star-forming regions, or active galactic nuclei. Depending on
+the physical size of the grains compared to the wavelength of the radiation
+field that drives the wind, two qualitatively different regimes emerge. In the
+case of grains that are larger than the radiation's wavelength -- termed the
+constant-drift regime -- the grain's equilibrium drift velocity through the gas
+is approximately independent of grain size, leading to strong correlations
+between differently sized grains that persist well into the saturated nonlinear
+turbulence. For grains that are smaller than the radiation's wavelength --
+termed the non-constant-drift regime -- the linear instability grows more
+slowly than the single-grain-size RDI and only the larger grains exhibit
+RDI-like behavior in the saturated state. A detailed study of grain clumping
+and grain-grain collisions shows that outflows in the constant-drift regime may
+be effective sites for grain growth through collisions, with large collision
+rates but low collision velocities.",2110.11422v2
+2021-11-12,Elastic Properties of Confined Fluids from Molecular Modeling to Ultrasonic Experiments on Porous Solids,"Fluids confined in nanopores are ubiquitous in nature and technology. In
+recent years, the interest in confined fluids has grown, driven by research on
+unconventional hydrocarbon resources -- shale gas and shale oil, much of which
+are confined in nanopores. When fluids are confined in nanopores, many of their
+properties differ from those of the same fluid in the bulk. These properties
+include density, freezing point, transport coefficients, thermal expansion
+coefficient, and elastic properties. The elastic moduli of a fluid confined in
+the pores contribute to the overall elasticity of the fluid-saturated porous
+medium and determine the speed at which elastic waves traverse through the
+medium. Wave propagation in fluid-saturated porous media is pivotal for
+geophysics, as elastic waves are used for characterization of formations and
+rock samples. In this paper, we present a comprehensive review of experimental
+works on wave propagation in fluid-saturated nanoporous media, as well as
+theoretical works focused on calculation of compressibility of fluids in
+confinement. We discuss models that bridge the gap between experiments and
+theory, revealing a number of open questions that are both fundamental and
+applied in nature. While some results were demonstrated both experimentally and
+theoretically (e.g. the pressure dependence of compressibility of fluids),
+others were theoretically predicted, but not verified in experiments (e.g.
+linear scaling of modulus with the pore size). Therefore, there is a demand for
+the combined experimental-modeling studies on porous samples with various
+characteristic pore sizes. The extension of molecular simulation studies from
+simple model fluids to the more complex molecular fluids is another open area
+of practical interest.",2111.06914v1
+2021-11-19,Accurate Photometry of Saturated Stars Using the Point-Spread-Function Wing Technique with Spitzer,"We report Spitzer 3.6 and 4.5 $\mu$m photometry of 11 bright stars relative
+to Sirius, exploiting the unique optical stability of the Spitzer Space
+Telescope point spread function (PSF). Spitzer's extremely stable beryllium
+optics in its isothermal environment enables precise comparisons in the wings
+of the PSF from heavily saturated stars. These bright stars stand as the
+primary sample to improve stellar models, and to transfer the absolute flux
+calibration of bright standard stars to a sample of fainter standards useful
+for missions like JWST and for large groundbased telescopes. We demonstrate
+that better than 1% relative photometry can be achieved using the PSF wing
+technique in the radial range of 20--100\arcsec\ for stars that are fainter
+than Sirius by 8 mag (from outside the saturated core to a large radius where a
+high signal-to-noise profile can still be obtained). We test our results by (1)
+comparing the [3.6]$-$[4.5] color with that expected between the WISE W1 and W2
+bands, (2) comparing with stars where there is accurate $K_{\text{S}}$
+photometry, and (3) also comparing with relative fluxes obtained with the DIRBE
+instrument on COBE. These tests confirm that relative photometry is achieved to
+better than 1%.",2111.10054v1
+2021-12-02,Fertilization of liquid-saturated porous medium with multicomponent gases due to surface temperature oscillation,"We study non-isothermal diffusive transport of a weakly-soluble two-component
+substance in a liquid-saturated porous medium being in contact with the
+reservoir of this substance. Particular attention is given to the example case
+of infiltration of nitrogen and oxygen from the atmosphere under the annual
+temperature oscillation. The surface temperature of the porous medium
+half-space oscillates in time, which results in a decaying solubility wave
+propagating deep into the porous medium. In such a system, the zones of
+saturated solution and nondissolved phase coexist with the zones of
+undersaturated solution; these zones migrate with time. Moreover, the
+solubility of a multicomponent substance depends on its composition, which
+results in a much more intricate mathematical model of solubility as compared
+to the single-component case. We describe the phenomenon of formation of a
+near-surface bubbly horizon due to the temperature oscillation. An analytical
+theory of the phenomenon is developed. For multicomponent solutions we report
+the formation of diffusion boundary layer, which is not possible for
+single-component solutions. We construct an analytical theory for this boundary
+layer; in particular, we derive effective boundary conditions for the problem
+of the diffusive transport beyond this layer.",2112.01290v1
+2022-01-17,Single-pion contribution to the Gerasimov--Drell--Hearn sum rule and related integrals,"Phenomenological amplitudes obtained in partial-wave analyses (PWA) of
+single-pion photoproduction are used to evaluate the contribution of this
+process to the Gerasimov-Drell-Hearn (GDH), Baldin and
+Gell-Mann-Goldberger-Thirring (GGT) sum rules, by integrating up to 2 GeV in
+photon energy. Our study confirms that the single-pion contribution to all
+these sum rules converges even before the highest considered photon energy, but
+the levels of saturation are very different in the three cases. Single-pion
+production almost saturates the GDH sum rule for the proton, while a large
+fraction is missing in the neutron case. The Baldin integrals for the proton
+and the neutron are both saturated to about four fifths of the predicted total
+strength. For the GGT sum rule, the wide variability in predictions precludes
+any definitive statement.",2201.06495v4
+2022-02-16,Physical factors governing the shape of the Miram curve knee in thermionic emission,"In a current density versus temperature (J-T) (Miram) curve in thermionic
+electron emission, experimental measurements demonstrate there is a smooth
+transition between the exponential region and the saturated emission regions,
+which is sometimes referred to as the ""roll-off"" or ""Miram curve knee"". The
+shape of the Miram curve knee is an important figure of merit for thermionic
+vacuum cathodes. Specifically, cathodes with a sharp Miram curve knee at low
+temperature with a flat saturated emission current are typically preferred. Our
+previous work on modeling nonuniform thermionic emission revealed that the
+space charge effect and patch field effect are key pieces of physics which
+impact the shape of the Miram curve knee. This work provides a more complete
+understanding of the physical factors connecting these physical effects and
+their relative impact on the shape of the knee, including the smoothness, the
+temperature, and the flatness of the saturated emission current density. For
+our analyses, we use a periodic, equal-width striped (""zebra crossing"") work
+function distribution as a model system and illustrate how the space charge and
+patch field effects restrict the emission current density near the Miram curve
+knee. The results indicate there are three main physical parameters which
+significantly impact the shape of the Miram curve. Such physical knowledge
+directly connects the patch size, work function values, anode-cathode voltage,
+and anode-cathode gap distance to the shape of the Miram curve, providing new
+understanding and a guide to the design of thermionic cathodes used as electron
+sources in vacuum electronic devices (VEDs).",2202.08247v1
+2022-03-10,Understanding Electrolyte Filling of Lithium-Ion Battery Electrodes on the Pore Scale Using the Lattice Boltzmann Method,"Electrolyte filling is a time-critical step during battery manufacturing that
+also affects the battery performance. The underlying physical phenomena during
+filling mainly occur on the pore scale and are hard to study experimentally. In
+this paper, a computational approach, i.e.\ the lattice Boltzmann method, is
+used to study the filling process and corresponding pore-scale phenomena in 3D
+lithium-ion battery cathodes. The electrolyte flow through the nanoporous
+binder is simulated using a homogenization approach. Besides the process time,
+the influence of structural and physico-chemical properties is investigated.
+Those are the particle size, the binder distribution, and the volume fraction
+and wetting behavior of active material and binder. Optimized filling
+conditions are discussed by capillary pressure-saturation relationships. It is
+shown how the aforementioned influencing factors affect the electrolyte
+saturation. Moreover, the amount of the entrapped residual gas phase and the
+corresponding size distribution of the gas agglomerates are analyzed in detail.
+Both factors are shown to have a strong impact on mechanisms that can adversely
+affect the battery performance. The results obtained here indicate how the
+filling process, the final electrolyte saturation, and potentially also the
+battery performance can be optimized by adapting process parameters and the
+electrode and electrolyte design.",2203.05218v1
+2022-05-19,Saturation and recurrence of quantum complexity in random local quantum dynamics,"Quantum complexity is a measure of the minimal number of elementary
+operations required to approximately prepare a given state or unitary channel.
+Recently, this concept has found applications beyond quantum computing -- in
+studying the dynamics of quantum many-body systems and the long-time properties
+of AdS black holes. In this context Brown and Susskind \cite{BrownSusskind17}
+conjectured that the complexity of a chaotic quantum system grows linearly in
+time up to times exponential in the system size, saturating at a maximal value,
+and remaining maximally complex until undergoing recurrences at
+doubly-exponential times. In this work we prove the saturation and recurrence
+of complexity in two models of chaotic time evolutions based on (i) random
+local quantum circuits and (ii) stochastic local Hamiltonian evolution. Our
+results advance an understanding of the long-time behaviour of chaotic quantum
+systems and could shed light on the physics of black hole interiors. From a
+technical perspective our results are based on establishing new quantitative
+connections between the Haar measure and high-degree approximate designs, as
+well as the fact that random quantum circuits of sufficiently high depth
+converge to approximate designs.",2205.09734v2
+2022-06-24,A critical analysis of the assumptions underlying the formulation of maximum potential intensity for tropical cyclones,"Emanuel's concept of maximum potential intensity (E-PI) estimates the maximum
+velocity of tropical cyclones from environmental parameters assuming thermal
+wind (gradient-wind and hydrostatic balances) and slantwise neutrality in the
+free troposphere. E-PI's key equation relates proportionally the radial
+gradients of saturated moist entropy and angular momentum. Here the E-PI
+derivation is reconsidered to show that the thermal wind and slantwise
+neutrality imply zero radial gradients of saturation entropy and angular
+momentum at an altitude where, for a given radius, the tangential wind has a
+maximum. It is further shown that, while E-PI's key equation requires that, at
+the point of maximum tangential wind, the air temperature must increase towards
+the storm center, the thermal wind equation dictates the opposite. From the
+analysis of the equations of motion at the altitude of maximum tangential wind
+in the free troposphere, it is concluded that here the air flow must be
+supergradient. This implies that the supergradiency factor (a measure of the
+gradient-wind imbalance) must change in the free troposphere as the air flow
+tends to restore the balance. It is shown that such a change modifies the
+derivative of saturation entropy over angular momentum, which cannot therefore
+remain constant in the free troposphere as E-PI requires. The implications of
+these findings for the internal coherence of E-PI, including its boundary layer
+closure, are discussed.",2206.12382v3
+2022-07-06,Adaptive Identification with Guaranteed Performance Under Saturated-Observation and Non-Persistent Excitation,"This paper investigates the adaptive identification and prediction problems
+for stochastic dynamical systems with saturated observations, which arise from
+various fields in engineering and social systems, but up to now still lack
+comprehensive theoretical studies including performance guarantees needed in
+practical applications. With this impetus, the paper has made the following
+main contributions: (i) To introduce a two-step Quasi-Newton (TSQN) algorithm
+to improve the performance of the identification, which is applicable to a
+typical class of nonlinear stochastic systems with outputs observed under
+possibly varying saturation. (ii) To establish the global convergence of both
+the parameter estimators and adaptive predictors and to prove the asymptotic
+normality, under the weakest possible non-persistent excitation (PE) condition,
+which can be applied to stochastic feedback systems with general non-stationary
+and correlated system signals or data. (iii) To establish useful probabilistic
+estimation error bounds for any given finite length of data, using either
+martingale inequalities or Monte Carlo experiments. A numerical example is also
+provided to illustrate the performance of the proposed identification
+algorithm.",2207.02422v5
+2022-07-21,Impact of pedestal density gradient and collisionality on ELM dynamics,"BOUT++ turbulence simulations are conducted to capture the underlying physics
+of the small ELM characteristics achieved by increasing separatrix density via
+controlling strike points from vertical to horizontal divertor plates for three
+EAST discharges. BOUT ++ linear simulations show that the most unstable modes
+change from high-n ideal ballooning modes to the intermediate-n
+peeling-ballooning modes and eventually to peeling-ballooning stable plasmas in
+the pedestal. Nonlinear simulations show that the fluctuation is saturated at a
+high level for the lowest separatrix density. The elm size decreases with
+increasing the separatrix density, until the fraction of this energy lost
+during the ELM crash becomes less than 1% of the pedestal stored energy,
+leading to small ELMs. Simulations indicate that small ELMs can be triggered
+either by the marginally peeling-ballooning instability near the peak pressure
+gradient position inside pedestal or by a local instability in the pedestal
+foot with a larger separatrix density gradient. The pedestal collisionality
+scan for type-I ELMs with steep pedestal density gradient shows that both
+linear growth rate and elm size decrease with collisionality increasing. While
+the pedestal collisionality and pedestal density width scan with a weak
+pedestal density gradient indicate small ELMs can either be triggered by high-n
+ballooning mode or by low-n peeling mode in low collisionality region 0.04~0.1.
+The simulations indicate the weaker the linear unstable modes near marginal
+stability with small linear growth rate, the lower nonlinearly saturated
+fluctuation intensity and the smaller turbulence spreading from the linear
+unstable zone to stable zone in the nonlinear saturation phase, leading to
+small ELMs.",2207.10594v2
+2022-08-17,"Characteristic, dynamic, and near saturation regions of Out-of-time-order correlation in Floquet Ising models","We study characteristic, dynamic, and saturation regimes of the
+out-of-time-order correlation (OTOC) in the constant field Floquet system with
+and without longitudinal field. In the calculation of OTOC, we take local spins
+in longitudinal and transverse directions as observables which are local and
+non-local in terms of Jordan-Wigner fermions, respectively. We use the exact
+analytical solution of OTOC for the integrable model (without longitudinal
+field term) with transverse direction spins as observables and numerical
+solutions for other integrable and nonintegrable cases. OTOCs generated in both
+cases depart from unity at a kick equal to the separation between the
+observables when the local spins in the transverse direction and one additional
+kick is required when the local spins in the longitudinal direction. The number
+of kicks required to depart from unity depends on the separation between the
+observables and is independent of the Floquet period and system size. In the
+dynamic region, OTOCs show power-law growth in both models, the integrable
+(without longitudinal field) as well as the nonintegrable (with longitudinal
+field). The exponent of the power-law increases with increasing separation
+between the observables. Near the saturation region, OTOCs grow linearly with a
+very small rate.",2208.08283v1
+2022-10-18,$λ$-MIMO: Massive MIMO via Modulo Sampling,"Massive multiple-input multiple-output (M-MIMO) architecture is the workhorse
+of modern communication systems. Currently, two fundamental bottlenecks,
+namely, power consumption and receiver saturation, limit the full potential
+achievement of this technology. These bottlenecks are intricately linked with
+the analog-to-digital converter (ADC) used in each radio frequency (RF) chain.
+The power consumption in MIMO systems grows exponentially with the ADC's bit
+budget while ADC saturation causes permanent loss of information. This
+motivates the need for a solution that can simultaneously tackle the
+above-mentioned bottlenecks while offering advantages over existing
+alternatives such as low-resolution ADCs. Taking a radically different approach
+to this problem, we propose $\lambda$-MIMO architecture which uses modulo ADCs
+($M_\lambda$-ADC) instead of a conventional ADC. Our work is inspired by the
+Unlimited Sampling Framework. $M_\lambda$-ADC in the RF chain folds high
+dynamic range signals into low dynamic range modulo samples, thus alleviating
+the ADC saturation problem. At the same time, digitization of modulo signal
+results in high resolution quantization. In the novel $\lambda$-MIMO context,
+we discuss baseband signal reconstruction, detection and uplink achievable
+sum-rate performance. The key takeaways of our work include, (a) leveraging
+higher signal-to-quantization noise ratio (SQNR), (b) detection and average
+uplink sum-rate performances comparable to a conventional, infinite-resolution
+ADC when using a $1$-$2$ bit $M_\lambda$-ADC. This enables higher order
+modulation schemes e.g. $1024$ QAM that seemed previously impossible, (c)
+superior trade-off between energy efficiency and bit budget, thus resulting in
+higher power efficiency. Numerical simulations and modulo ADC based hardware
+experiments corroborate our theory and reinforce the clear benefits of
+$\lambda$-MIMO approach.",2210.10193v1
+2022-11-09,Deterministic Random Walk Model in NetLogo and the Identification of Asymmetric Saturation Time in Random Graph,"Interactive programming environments are powerful tools for promoting
+innovative network thinking, teaching science of complexity, and exploring
+emergent phenomena. This paper reports on our recent development of the
+deterministic random walk model in NetLogo, a leading platform for
+computational thinking, eco-system thinking, and multi-agent cross-platform
+programming environment. The deterministic random walk is foundational to
+modeling dynamical processes on complex networks. Inspired by the temporal
+visualizations offered in NetLogo, we investigated the relationship between
+network topology and diffusion saturation time for the deterministic random
+walk model. Our analysis uncovers that in Erd\H{o}s-R\'{e}nyi graphs, the
+saturation time exhibits an asymmetric pattern with a considerable probability
+of occurrence. This behavior occurs when the hubs, defined as nodes with
+relatively higher number of connections, emerge in Erd\H{o}s-R\'{e}nyi graphs.
+Yet, our analysis yields that the hubs in Barab\'{a}si-Albert model stabilize
+the the convergence time of the deterministic random walk model. These findings
+strongly suggest that depending on the dynamical process running on complex
+networks, complementing characteristics other than the degree need to be taken
+into account for considering a node as a hub. We have made our development
+open-source, available to the public at no cost at
+https://github.com/bravandi/NetLogo-Dynamical-Processes.",2211.05189v2
+2022-11-11,Parallelization of Garfield++ and neBEM to simulate space charge effects in RPCs,"Numerical simulation of avalanches, saturated avalanches, and streamers can
+help us understand the detector physics of Resistive Plate Chambers (RPC). 3D
+Monte Carlo simulation of an avalanche inside an RPC, the transition from
+avalanche to saturated avalanche to streamer may help the search for the
+optimum voltage and alternate gas mixtures. This task is dauntingly
+resource-hungry, especially when space charge effects become important, which
+often coincides with important regimes of operation of these devices. By
+modifying the electric field inside the RPC dynamically, the space charge plays
+a crucial role in determining the response of the detector. In this work, a
+numerical model has been proposed to calculate the dynamic space-charge field
+inside an RPC and the same has been implemented in the Garfield++ framework. By
+modeling space charge as the large number of line charges and using the
+multithreading technique OpenMP to calculate electric field, drift line,
+electron gain, and space charge field, it has been possible to maintain time
+consumption within reasonable limits. For this purpose, a new class,
+pAvalancheMC has been introduced in Garfield++. The calculations have been
+successfully verified with those from existing solvers and an example is
+provided to show the performance of pAvalancheMC. Moreover, the details of the
+transition of an avalanche into a saturated avalanche have been discussed. The
+induced charge distribution is calculated for a timing RPC and results are
+verified with the experiment.",2211.06361v3
+2022-11-28,The effect of saturated thermal conduction on clouds in a hot plasma,"We numerically investigate the internal evolution of multiphase clouds, which
+are at rest with respect to an ambient, highly ionized medium (HIM)
+representing the hot component of the circumgalactic medium (CGM).
+Time-dependent saturated thermal conduction and its implications like
+condensation rates and mixing efficiency are assessed in multiphase clouds. Our
+simulations are carried out by using the adaptive mesh refinement code Flash.
+We perform a grid of models of which we present here those characteristic for
+the presented study. The model clouds are initially in both hydrostatic and
+thermal equilibrium and are in pressure balance with the HIM. Thus, they have
+steep gradients in both temperature and density at the interface to HIM leading
+to non-negligible thermal conduction. Several physical processes are considered
+numerically or semi-analytically: thermal conduction, radiative cooling and
+external heating of gas, self-gravity, mass diffusion, and dissociation of
+molecules and ionization of atoms. It turns out that saturated thermal
+conduction triggers a continuous condensation irrespective of cloud mass.
+Dynamical interactions with ambient HIM all relate to the radial density
+gradient in the clouds: (1) mass flux due to condensation is the higher the
+more homogeneous the clouds are; (2) mixing of condensed gas with cloud gas is
+easier in low-mass clouds, because of their shallower radial density gradient;
+thus (3) accreted gas is distributed more efficiently. A distinct and
+sub-structured transition zone forms at the interface between cloud and HIM,
+which starts at smaller radii and is much narrower as deduced from analytical
+theory.",2211.15284v1
+2023-01-17,"Parametric instability in warped astrophysical discs: growth, saturation and feedback","Attempts to understand the dynamics of warped astrophysical discs have
+garnered significant attention, largely motivated by the growing catalogue of
+observed distorted systems. Previous studies have shown that the evolution of
+the warp is crucially regulated by the internal flow fields established by the
+undulating geometry. These are typically modelled as laminar horizontal,
+shearing flows which oscillate back and forth at approximately the orbital
+frequency. However this shearing motion is known to be susceptible to a
+hydrodynamic, parametric instability of inertial waves which might modify the
+warped dynamics. Whilst the linear growth phase is well understood, the
+subsequent nonlinear saturation combined with the self-consistent feedback onto
+the warp has not been studied. In this work, we implement a novel numerical
+setup using the recent ring model framework of Fairbairn and Ogilvie, within
+the Lagrangian code GIZMO. We formally identify several locally growing modes
+in the simulation, as predicted by a three-mode coupling analysis of the
+instability, and find decent agreement with the theoretical growth rates. We
+understand the saturation mechanism as a wave breaking process which suppresses
+the growth of shorter wavelength parametric couplings first, whilst allowing
+the longest mode to dominate the final quasi-steady, wavelike turbulence. The
+Reynolds stresses, transporting energy from the warp to the small scales, can
+be effectively modelled using a time-dependent, anisotropic viscous alpha model
+which closely captures the amplitude and phase evolution of the warp.
+Consequently, this model might help inform future global studies which are
+commonplace but typically don't resolve the parametric instability.",2301.07176v1
+2023-01-29,Revealing a deep connection between factorization and saturation: New insight into modeling high-energy proton-proton and nucleus-nucleus scattering in the EPOS4 framework,"It is known that multiple partonic scatterings in high-energy proton-proton
+($pp$) collisions must happen in parallel. However, a rigorous parallel
+scattering formalism, taking energy sharing properly into account, fails to
+reproduce factorization, which on the other hand is the basis of almost all
+$pp$ event generators. In addition, binary scaling in nuclear scatterings is
+badly violated. These problems are usually ``solved'' by simply not considering
+strictly parallel scatterings, which is not a solution. I will report on new
+ideas (leading to EPOS4), which allow recovering perfectly factorization, and
+also binary scaling in $AA$ collisions, in a rigorous unbiased parallel
+scattering formalism. In this new approach, dynamical saturation scales play a
+crucial role, and this seems to be the missing piece needed to reconcile
+parallel scattering with factorization. From a practical point of view, one can
+compute within the EPOS4 framework parton distribution functions (EPOS PDFs)
+and use them to compute inclusive $pp$ cross sections. So, for the first time,
+one may compute inclusive jet production (for heavy or light flavors) at very
+high transverse momentum ($p_{t}$) and at the same time in the same formalism
+study flow effects at low $p_{t}$ in high-multiplicity $pp$ events, making
+EPOS4 a full-scale ``general purpose event generator''. I discuss applications,
+essentially multiplicity dependencies (of particle ratios, mean $p_{t}$, charm
+production) which are very strongly affected by the saturation issues discussed
+in this paper.",2301.12517v2
+2023-03-08,MCTS-GEB: Monte Carlo Tree Search is a Good E-graph Builder,"Rewrite systems [6, 10, 12] have been widely employing equality saturation
+[9], which is an optimisation methodology that uses a saturated e-graph to
+represent all possible sequences of rewrite simultaneously, and then extracts
+the optimal one. As such, optimal results can be achieved by avoiding the
+phase-ordering problem. However, we observe that when the e-graph is not
+saturated, it cannot represent all possible rewrite opportunities and therefore
+the phase-ordering problem is re-introduced during the construction phase of
+the e-graph. To address this problem, we propose MCTS-GEB, a domain-general
+rewrite system that applies reinforcement learning (RL) to e-graph
+construction. At its core, MCTS-GEB uses a Monte Carlo Tree Search (MCTS) [3]
+to efficiently plan for the optimal e-graph construction, and therefore it can
+effectively eliminate the phase-ordering problem at the construction phase and
+achieve better performance within a reasonable time. Evaluation in two
+different domains shows MCTS-GEB can outperform the state-of-the-art rewrite
+systems by up to 49x, while the optimisation can generally take less than an
+hour, indicating MCTS-GEB is a promising building block for the future
+generation of rewrite systems.",2303.04651v3
+2023-03-17,"Optical IRSs: Power Scaling Law, Optimal Deployment, and Comparison with Relays","The line-of-sight (LOS) requirement of free-space optical (FSO) systems can
+be relaxed by employing optical relays or optical intelligent reflecting
+surfaces (IRSs). In this paper, we show that the power reflected from FSO IRSs
+and collected at the receiver (Rx) lens may scale quadratically or linearly
+with the IRS size or may saturate at a constant value. We analyze the power
+scaling law for optical IRSs and unveil its dependence on the wavelength,
+transmitter (Tx)-to-IRS and IRS-to-Rx distances, beam waist, and Rx lens size.
+We also consider the impact of linear, quadratic, and focusing phase shift
+profiles across the IRS on the power collected at the Rx lens for different IRS
+sizes. Our results reveal that surprisingly the powers received for the
+different phase shift profiles are identical, unless the IRS operates in the
+saturation regime. Moreover, IRSs employing the focusing (linear) phase shift
+profile require the largest (smallest) size to reach the saturation regime. We
+also compare optical IRSs in different power scaling regimes with optical
+relays in terms of the outage probability, diversity and coding gains, and
+optimal placement. Our results show that, at the expense of a higher hardware
+complexity, relay-assisted FSO links yield a better outage performance at high
+signal-to-noise-ratios (SNRs), but optical IRSs can achieve a higher
+performance at low SNRs. Moreover, while it is optimal to place relays
+equidistant from Tx and Rx, the optimal location of optical IRSs depends on the
+phase shift profile and the power scaling regime they operate in.",2303.10124v1
+2023-04-04,On A Saturated Poromechanical Framework and Its Relation to Abaqus Soil Mechanics and Biot Poroelasticity Frameworks,"We introduce a conservational and constitutive framework for a closed and
+isothermal two-phase material system consisting of a deformable porous solid
+matrix and a fully saturating, single-phase, and compressible pore fluid
+without inter-phase mass exchange. We re-derive a generalized fluid mass
+balance law using fundamental transport rules. We also summarize from the
+literature a fundamental force balance law for the fluid-solid mixture that
+does not require any effective stress law a priori. We show that the two
+conservation laws are coupled naturally to second-order without any
+constitutive prerequisites. This differs from Biot poroelasticity, which first
+postulates first-order fluid-solid coupling as two linearized constitutive
+relationships and then enforces them into simple Eulerian form of conservation
+laws. Next, we examine a limiting-case unsaturated soil mechanics framework
+implemented in Abaqus, by assuming isothermal conditions, full saturation, and
+no adsorption, and then relate it to our framework. We prove that (1) the two
+mass balance laws are always equivalent regardless of fluid constitutive
+behaviors, and (2) the two force balance laws are equivalent in their specific
+forms with a linearly elastic solid skeleton. Finally, taking advantage of a
+fundamental pore constitutive law, we show how our framework, and by extension
+the limiting-case Abaqus framework, naturally gives rise to the distinction
+between drained and undrained settings, and reduces to Biot poroelasticity
+under simplifying conditions. Notably, our framework indicates the presence of
+an additional solid-to-fluid coupling term when the solid particle velocity is
+non-orthogonal to the Darcy velocity.",2304.02148v1
+2023-05-02,Frequency-modulated combs via on-chip field enhancement,"Frequency-modulated (FM) combs feature flat intensity spectra with a linear
+frequency chirp, useful for metrology and sensing applications. Generating FM
+combs in semiconductor lasers generally requires a fast saturable gain, usually
+limited by the intrinsic gain medium properties. Here, we show how a spatial
+modulation of the laser gain medium can enhance the gain saturation dynamics
+and nonlinearities to generate self-starting FM combs. We demonstrate this with
+tapered planarized THz quantum cascade lasers (QCLs). While simple ridge THz
+QCLs typically generate combs which are a mixture of amplitude and frequency
+modulation, the on-chip field enhancement resulting from extreme spatial
+confinement leads to an ultrafast saturable gain regime, generating a pure FM
+comb with a flatter intensity spectrum, a clear linear frequency chirp and very
+intense beatnotes up to -30 dBm. The observed linear frequency chirp is
+reproduced using a spatially inhomogeneous mean-field theory model which
+confirms the crucial role of field enhancement. In addition, the modified
+spatial temperature distribution within the waveguide results in an improved
+hightemperature comb operation, up to a heat sink temperature of 115 K, with
+comb bandwidths of 600 GHz at 90 K. The spatial inhomogeneity also leads to
+dynamic switching between various harmonic states in the same device.",2305.01483v2
+2023-05-25,"Rotating spokes, potential hump and modulated ionization in radio frequency magnetron discharges","In this work, the rotating spoke mode in the radio frequency (RF) magnetron
+discharge, which features the potential hump and the RF-modulated ionization,
+is observed and analyzed by means of the two dimensional axial-azimuthal (z-y)
+particle-in-cell/Monte Carlo collision method. The kinetic model combined with
+the linear analysis of the perturbation reveals that the cathode sheath (axial)
+electric field $E_z$ triggers the gradient drift instability (GDI), deforming
+the local potential until the instability condition is not fulfilled and the
+fluctuation growth stops in which moment the instability becomes saturated. The
+potential deformation consequently leads to the formation of the potential
+hump, surrounding which the azimuthal electric field $E_y$ is present. The
+saturation level of $E_y$ is found to be synchronized with and proportional to
+the time-changing voltage applied at the cathode, resulting in the
+RF-modulation of the electron heating in the $E_y$ due to $\nabla B$ drift. In
+the instability saturated stage, it is shown that the rotation velocity and
+direction of the spoke present in the simulations agree well with the
+experimental observation. In the instability linear stage, the instability mode
+wavelength and the growth rate are also found to be in good agreement with the
+prediction of the GDI linear fluid theory.",2305.15941v1
+2023-06-20,Spectral and Krylov Complexity in Billiard Systems,"In this work, we investigate spectral complexity and Krylov complexity in
+quantum billiard systems at finite temperature. We study both circle and
+stadium billiards as paradigmatic examples of integrable and non-integrable
+quantum-mechanical systems, respectively. We show that the saturation value and
+time scale of spectral complexity may be used to probe the non-integrability of
+the system since we find that when computed for the circle billiard, it
+saturates at a later time scale compared to the stadium billiards. This
+observation is verified for different temperatures. Furthermore, we study the
+Krylov complexity of the position operator and its associated Lanczos
+coefficients at finite temperature using the Wightman inner product. We find
+that the growth rate of the Lanczos coefficients saturates the conjectured
+universal bound at low temperatures. Additionally, we also find that even a
+subset of the Lanczos coefficients can potentially serve as an indicator of
+integrability, as they demonstrate erratic behavior specifically in the circle
+billiard case, in contrast to the stadium billiard. Finally, we also study
+Krylov entropy and verify its early-time logarithmic relation with Krylov
+complexity in both types of billiard systems.",2306.11632v1
+2023-08-10,Globally optimal interferometry with lossy twin Fock probes,"Parity or $J_{z}^{2}$ readouts of a Mach-Zehnder (MZ) interferometer probed
+with a twin Fock input state allow to saturate the optimal sensitivity
+attainable among all product states with a fixed total number of particles, but
+only when the interferometer phase $\theta$ is near zero. When more general
+Dicke state probes are used, the parity readout saturates the QFI at
+$\theta=0$, whereas better-than-standard quantum limit performance of the
+$J_{z}^{2}$ readout is restricted to an $o(\sqrt{N})$ occupation imbalance. We
+show that a method of moments readout of two quadratic spin observables
+$J_{z}^{2}$ and $J_{+}^{2}+J_{-}^{2}$ is globally optimal for Dicke state
+probes, i.e., the error saturates the QFI for all $\theta$. In the lossy
+setting, we derive the time-inhomogeneous Markov process describing the effect
+of particle loss on twin Fock states, showing that method of moments readout of
+four at-most-quadratic spin observables is sufficient for globally optimal
+estimation of $\theta$ when two or more particles are lost. The analysis
+culminates in a numerical calculation of the QFI matrix for distributed MZ
+interferometry on the four mode state $\vert {N\over 4},{N\over 4},{N\over
+4},{N\over 4}\rangle$ and its lossy counterparts, showing that an advantage for
+estimation of any linear function of the local MZ phases $\theta_{1}$,
+$\theta_{2}$ (compared to independent probing of the MZ phases by two copies of
+$\vert{N\over 4},{N\over 4}\rangle$) appears when more than one particle is
+lost.",2308.05871v1
+2023-08-20,A Method to Measure Photometries of Moderately-Saturated UVOT Sources,"For bright transients such as Gamma-Ray Bursts (GRBs), the
+Ultra-Violet/Optical Telescope (UVOT) operates under event mode at early
+phases, which records incident positions and arrival time for each photon. The
+event file is able to be screened into many exposures to study the early light
+curve of GRBs with a high time resolution, including in particular the rapid
+brightening of the UV/Optical emission. Such a goal, however, is hampered for
+some extremely bright GRBs by the saturation in UVOT event images. For
+moderately saturated UVOT sources, in this work we develop the method proposed
+in Jin et al. (2023) to recover their photometries. The basic idea is to assume
+a stable point spread function (PSF) of UVOT images, for which the counts in
+the core region (i.e., an aperture of a radius of 5 arcsec) and the wing region
+(i.e., an annulus ranging from 15 arcsec to 25 arcsec) should be a constant and
+the intrinsic flux can be reliably inferred with data in the ring. We
+demonstrate that in a given band, a tight correlation does hold among the
+background-removed count rates in the core and the wing. With the new method,
+the bright limit of measuring range for UVOT V and B bands increases ~ 1.7 mag,
+while only ~ 0.7 mag for U band due to the lack of bright calibration sources.
+Systematic uncertainties are ~ 0.2 mag for V, B and U bands.",2308.10171v1
+2023-08-24,The key to the enhanced performance of slab-like topologically interlocked structures with non-planar blocks,"Topologically interlocked structures are assemblies of interlocking blocks
+that hold together solely through contact. Such structures have been shown to
+exhibit high strength, energy dissipation, and crack arrest properties. Recent
+studies on topologically interlocked structures have shown that both the peak
+strength and work-to-failure saturate with increasing friction coefficient.
+However, this saturated structural response is only achievable with
+nonphysically high values of the friction coefficient. For beam-like
+topologically interlocked structures, non-planar blocks provide an alternate
+approach to reach similar structural response with friction properties of
+commonly used materials. It remains unknown whether non-planar blocks have
+similar effects for slab-like assemblies, and what the achievable structural
+properties are. Here, we consider slab-like topologically interlocked
+structures and show, using numerical simulations, that non-planar blocks with
+wave-like surfaces allow for saturated response capacity of the structure with
+a realistic friction coefficient. We further demonstrate that non-planar
+morphologies cause a non-linear scaling of the work-to-failure with peak
+strength and result in significant improvements of the work-to-failure and
+ultimate deflection - values that cannot be attained with planar-faced blocks.
+Finally, we show that the key morphology parameter responsible for the enhanced
+performance of non-planar blocks with wave-like surfaces is the local angle of
+inclination at the hinging points of the loaded block. These findings shed new
+light on topologically interlocked structures with non-planar blocks, allowing
+for a better understanding of their strengths and energy absorption.",2308.12683v2
+2023-09-02,Electric-field induced droplet vertical vibration and horizontal motion: Experiments and simulations,"In this work, Electrowetting on Dielectric (EWOD) and electrostatic induction
+(ESI) are employed to manipulate droplet on the PDMS-ITO substrate. Firstly, we
+report large vertical vibrations of the droplet, induced by EWOD, within a
+voltage range of 40 to 260 V. The droplet's transition from a vibrating state
+to a static equilibrium state are investigated in detail. It is indicated that
+the contact angle changes synchronously with voltage during the vibration. The
+electric signal in the circuit is measured to analyze the vibration state that
+varies with time. By studying the influence of driving voltage on the contact
+angle and the amplitude in the vibration, it is shown that the saturation
+voltage of both contact angle and amplitude is about 120 V. The intrinsic
+connection between contact angle saturation and amplitude saturation is
+clarified by studying the surface energy of the droplet. A theoretical model is
+constructed to numerically simulate the vibration morphology and amplitude of
+the droplet. Secondly, we realize the horizontal motion of droplets by ESI at
+the voltage less than 1000 V. The charge and electric force on the droplet are
+numerically calculated. The frictional resistance coefficients of the droplet
+are determined by the deceleration of the droplet. Under consideration of
+frictional resistance of the substrate and viscous resistance of the liquid,
+the motion of the droplet is calculated at 400 V and 1000 V, respectively. This
+work introduces a new method for manipulating various forms of droplet motion
+using the single apparatus.",2309.00910v1
+2023-09-22,AnglE-optimized Text Embeddings,"High-quality text embedding is pivotal in improving semantic textual
+similarity (STS) tasks, which are crucial components in Large Language Model
+(LLM) applications. However, a common challenge existing text embedding models
+face is the problem of vanishing gradients, primarily due to their reliance on
+the cosine function in the optimization objective, which has saturation zones.
+To address this issue, this paper proposes a novel angle-optimized text
+embedding model called AnglE. The core idea of AnglE is to introduce angle
+optimization in a complex space. This novel approach effectively mitigates the
+adverse effects of the saturation zone in the cosine function, which can impede
+gradient and hinder optimization processes. To set up a comprehensive STS
+evaluation, we experimented on existing short-text STS datasets and a newly
+collected long-text STS dataset from GitHub Issues. Furthermore, we examine
+domain-specific STS scenarios with limited labeled data and explore how AnglE
+works with LLM-annotated data. Extensive experiments were conducted on various
+tasks including short-text STS, long-text STS, and domain-specific STS tasks.
+The results show that AnglE outperforms the state-of-the-art (SOTA) STS models
+that ignore the cosine saturation zone. These findings demonstrate the ability
+of AnglE to generate high-quality text embeddings and the usefulness of angle
+optimization in STS.",2309.12871v6
+2023-10-13,"Parallel scattering, saturation, and generalized Abramovskii-Gribov-Kancheli (AGK) theorem in the EPOS4 framework, with applications for heavy-ion collisions at $\sqrt{s_{NN}}$ of 5.02 TeV and 200 GeV","Ultrarelativistic heavy-ion collisions will first realize many
+nucleon-nucleon scatterings, happening instantaneously and therefore
+necessarily in parallel, due to the short collision time. An appropriate
+quantum mechanical tool to treat that problem is S-matrix theory, and it has
+been known for a long time how to derive a simple geometric probabilistic
+picture, still widely used, and here the Abramovskii-Gribov-Kancheli (AGK)
+theorem plays a crucial role. All this is done in a scenario where energy
+conservation is not taken care of, but this is needed, in particular for Monte
+Carlo simulations. When introducing energy-momentum sharing properly, the AGK
+theorem does not apply anymore, nor do simple geometric concepts such as binary
+scaling. I will discuss this (very serious) problem, and how it can be solved,
+in the EPOS4 framework. When connecting the multiple Pomeron approach (for
+parallel scatterings) and perturbative QCD, one is actually forced to implement
+in a very particular way saturation scales, in order to get an approach free of
+contradictions. One recovers a generalized AGK theorem (gAGK), valid at large
+$p_{t}$ (larger than the relevant saturation scales). I discuss how gAGK is
+related to factorization (in proton-proton scatterings) and binary scaling (in
+heavy-ion collisions). I will show some applications, using this new approach
+as an initial condition for hydrodynamical evolutions, for heavy-ion collisions
+at $\sqrt{s_{NN}}$ of 5.02 TeV and 200 GeV, to get some idea about the energy
+dependence.",2310.09380v2
+2023-10-24,Adapted Thermodynamical Model for the Prediction of Adsorption in Nanoporous Materials,"In this paper, we introduce a novel, adapted approach for computing gas
+adsorption properties in porous materials. We analyze the Dubinin-Polanyi's
+adsorption model and investigate various frameworks to estimate its required
+essential components. Those are linked to physicochemical properties of the
+adsorbates, such as the vapor saturation pressure and density in the adsorbed
+state. To conduct this analysis, we obtain adsorption isotherms for several
+metal-organic frameworks, encompassing a range of pore sizes, shapes, and
+chemical compositions. We then apply and evaluate multiple combinations of
+models for saturation pressure and density.
+  After the evaluation of the method, we propose a working thermodynamic model
+for computing adsorption isotherms, which entails using the critical isochore
+as an approximation of the saturation pressure above the critical point and
+applying Hauer's method with a universal thermal expansion coefficient for
+density in the adsorbed state. This framework is applicable not only to
+simulated isotherms but also to experimental data from the literature for
+various molecules and structures, demonstrating robust predictive capabilities
+and high transferability. Our method showcases superior performance in terms of
+accuracy, generalizability, and simplicity compared to existing methods
+currently in use. For the first time, a method starting from a single
+adsorption curve and based on physically interpretable parameters can predict
+adsorption properties across a wide range of operating conditions.",2310.15885v1
+2023-11-01,Sparsity independent Lyapunov exponent in the Sachdev-Ye-Kitaev model,"The saturation of a recently proposed universal bound on the Lyapunov
+exponent has been conjectured to signal the existence of a gravity dual. This
+saturation occurs in the low temperature limit of the dense Sachdev-Ye-Kitaev
+(SYK) model, $N$ Majorana fermions with $q$-body ($q>2$) infinite-range
+interactions. We calculate certain Out of Time Order Correlators (OTOC) for
+$N\le 64$ fermions for a highly sparse SYK model and find no significant
+dependence of the Lyapunov exponent on sparsity up to near the percolation
+limit where the Hamiltonian breaks up into blocks. This suggests that in the
+sparse case, the Lyapunov exponent also saturates the low-temperature bound. A
+key ingredient to reaching $N = 64$ is the development of a novel quantum spin
+model simulation library that implements highly-optimized matrix-free Krylov
+subspace methods on Graphical Processing Units (GPUs). This leads to a
+significantly lower simulation time as well as vastly reduced memory usage over
+previous approaches, while using modest computational resources. Strong
+sparsity-driven statistical fluctuations require both the use of a vastly
+larger number of disorder realizations with respect to the dense limit and a
+careful finite size scaling analysis. Our results potentially broadens the
+landscape of theories that may have a gravity analogue.",2311.00639v1
+2023-11-12,"Advanced Feedback Linearization Control for Tiltrotor UAVs: Gait Plan, Controller Design, and Stability Analysis","Three challenges, however, can hinder the application of Feedback
+Linearization: over-intensive control signals, singular decoupling matrix, and
+saturation. Activating any of these three issues can challenge the stability
+proof. To solve these three challenges, first, this research proposed the drone
+gait plan. The gait plan was initially used to figure out the control problems
+in quadruped (four-legged) robots; applying this approach, accompanied by
+Feedback Linearization, the quality of the control signals was enhanced. Then,
+we proposed the concept of unacceptable attitude curves, which are not allowed
+for the tiltrotor to travel to. The Two Color Map Theorem was subsequently
+established to enlarge the supported attitude for the tiltrotor. These theories
+were employed in the tiltrotor tracking problem with different references.
+Notable improvements in the control signals were witnessed in the tiltrotor
+simulator. Finally, we explored the control theory, the stability proof of the
+novel mobile robot (tilt vehicle) stabilized by Feedback Linearization with
+saturation. Instead of adopting the tiltrotor model, which is over-complicated,
+we designed a conceptual mobile robot (tilt-car) to analyze the stability
+proof. The stability proof (stable in the sense of Lyapunov) was found for a
+mobile robot (tilt vehicle) controlled by Feedback Linearization with
+saturation for the first time. The success tracking result with the promising
+control signals in the tiltrotor simulator demonstrates the advances of our
+control method. Also, the Lyapunov candidate and the tracking result in the
+mobile robot (tilt-car) simulator confirm our deductions of the stability
+proof. These results reveal that these three challenges in Feedback
+Linearization are solved, to some extents.",2311.06725v1
+2023-11-12,A Nonlinear Negative Imaginary Systems Framework with Actuator Saturation for Control of Electrical Power Systems,"In the transition to net zero, it has been suggested that a massive expansion
+of the electric power grid will be required to support emerging renewable
+energy zones. In this paper, we propose the use of battery-based feedback
+control and nonlinear negative imaginary systems theory to reduce the need for
+such an expansion by enabling the more complete utilization of existing grid
+infrastructure. By constructing a novel Lur'e-Postnikov-like Lyapunov function,
+a stability result is developed for the feedback interconnection of a nonlinear
+negative imaginary system and a nonlinear negative imaginary controller.
+Additionally, a new class of nonlinear negative imaginary controllers is
+proposed to deal with actuator saturation. We show that in this control
+framework, the controller eventually leaves the saturation boundary, and the
+feedback system is locally stable in the sense of Lyapunov. This provides
+theoretical support for the application of battery-based control in electrical
+power systems. Validation through simulation results for
+single-machine-infinite-bus power systems supports our results. Our approach
+has the potential to enable a transmission line to operate at its maximum power
+capacity, as stability robustness is ensured by the use of a feedback
+controller.",2311.06820v1
+2024-01-19,From Market Saturation to Social Reinforcement: Understanding the Impact of Non-Linearity in Information Diffusion Models,"Diffusion of information in networks is at the core of many problems in AI.
+Common examples include the spread of ideas and rumors as well as marketing
+campaigns. Typically, information diffuses at a non-linear rate, for example,
+if markets become saturated or if users of social networks reinforce each
+other's opinions. Despite these characteristics, this area has seen little
+research, compared to the vast amount of results for linear models, which
+exhibit less complex dynamics. Especially, when considering the possibility of
+re-infection, no fully rigorous guarantees exist so far.
+  We address this shortcoming by studying a very general non-linear diffusion
+model that captures saturation as well as reinforcement. More precisely, we
+consider a variant of the SIS model in which vertices get infected at a rate
+that scales polynomially in the number of their infected neighbors, weighted by
+an infection coefficient $\lambda$. We give the first fully rigorous results
+for thresholds of $\lambda$ at which the expected survival time becomes
+super-polynomial. For cliques we show that when the infection rate scales
+sub-linearly, the threshold only shifts by a poly-logarithmic factor, compared
+to the standard SIS model. In contrast, super-linear scaling changes the
+process considerably and shifts the threshold by a polynomial term. For stars,
+sub-linear and super-linear scaling behave similar and both shift the threshold
+by a polynomial factor. Our bounds are almost tight, as they are only apart by
+at most a poly-logarithmic factor from the lower thresholds, at which the
+expected survival time is logarithmic.",2401.10818v1
+2024-01-28,WetSpongeCake: a Surface Appearance Model Considering Porosity and Saturation,"Wet powdered materials, such as wet ground or moist walls, are common in the
+real world. Despite their particle size being larger than the wavelength, they
+remain invisible from a macro view. Reproducing these appearances accurately is
+crucial for various applications. Existing methods use different approaches,
+such as Monte Carlo path tracing on implicit shapes, which is accurate but
+computationally expensive. Another approach involves modeling powdered
+materials with a medium using the radiative transfer equation, but these
+methods are computationally intensive and lack intuitive parameters. Some works
+represent porosity with cylinder-shaped holes on surfaces, but they have
+limitations. In this paper, we propose a practical BSDF model called
+WetSpongeCake for wet powdered materials. This model includes controllable
+physical parameters to faithfully reproduce real-world appearances while
+remaining computationally efficient. We reformulate Monte Carlo light transport
+on implicit shapes into a medium, utilizing an equivalent phase function for
+light transport within ellipsoid-shaped particles and a modified RTE for
+porosity and saturation effects. Our novel WetSpongeCake BSDF integrates this
+medium into the SpongeCake framework, allowing representation of various wet
+powdered material appearances, including both reflection and transmission. We
+showcase our model with examples, such as wet paper, sand saturated with
+different liquids, and sculptures made of multiple particles.",2401.15628v2
+2024-02-05,The footprint of nuclear saturation properties on the neutron star $f$ mode oscillation frequencies: a machine learning approach,"We investigate the intricate relationships between the non-radial \(f\) mode
+oscillation frequencies of neutron stars (NS)s and the corresponding nuclear
+matter equation of state (EOS) using a machine learning (ML) approach within
+the ambit of the relativistic mean field (RMF) framework for nuclear matter.
+With two distinct parameterizations of the Walecka model, namely, (1) with
+non-linear self interactions of the scalar field (NL) and, (2) a density
+dependent Bayesian model (DDB), we perform a thorough examination of the \(f\)
+mode frequency in relation to various nuclear saturation properties. The
+correlations between the \(f\) mode frequencies and nuclear saturation
+properties reveal, through various analytical and ML methods, the complex
+nature of NSs and their potential as the cosmic laboratory for studying extreme
+states of matter. A principal component analysis (PCA) has been performed using
+mixed datasets from DDB and NL models to discriminate the relative importance
+of the different components of the EOS on the $f$ mode frequencies.
+Additionally, a {\it Random forest feature importance} analysis also elucidates
+the distinct roles of these properties in determining the \(f\) mode frequency
+across a spectrum of NS masses. Our findings are further supported by symbolic
+regression searches, yielding high-accuracy relations with strong Pearson
+coefficients and minimal errors. These relations suggest new methodologies for
+probing NS core characteristics, such as energy density, pressure, and speed of
+sound from observations of non-radial \(f\) mode oscillations of NSs.",2402.03054v1
+2024-03-08,Beam-driven Electron Cyclotron Harmonic and Whistler-mode Waves as Seen in Particle-In-Cell Simulations,"Recent study has demonstrated that electron cyclotron harmonic (ECH) waves
+can be excited by a low energy electron beam. Such waves propagate at
+moderately oblique wave normal angles ~70. The potential role of beam-driven
+ECH waves in affecting electron dynamics in Earth's plasma sheet is not known.
+Using two-dimensional Darwin particle-in-cell simulations with initial electron
+distributions that represent typical plasma conditions in the plasma sheet, we
+explore the excitation and saturation of such beam-driven ECH waves. Both ECH
+and whistler-mode waves are excited in the simulation and propagate at oblique
+wave normal angles. Compared with the whistler-mode waves, ECH waves grow much
+faster and have more intense saturation amplitudes. Cold, stationary electrons
+are first accelerated by ECH waves through cyclotron resonance and then
+accelerated in the parallel direction by both the ECH and whistler-mode waves
+through Landau resonance. Beam electrons, on the other hand, are decelerated in
+the parallel direction and scattered to larger pitch angles. The relaxation of
+the electron beam and the continuous heating of the cold electrons contribute
+to the saturation of ECH waves and suppress the excitation of whistler-mode
+waves. When the ratio of plasma to electron cyclotron frequency wpe/wce
+increases, the ECH wave amplitude increases while the whistler-mode wave
+amplitude decreases. Our work reveals the importance of ECH and whistler-mode
+waves in reshaping sub-thermal electron distributions and improves our
+understanding on the potential effects of wave-particle interactions in
+trapping ionospheric electron outflows and forming anisotropic (field-aligned)
+electron distributions in the plasma.",2403.05675v1
+2024-03-13,Suppression of diffraction in deep-inelastic scattering on nuclei and dynamical mechanism of leading twist nuclear shadowing,"Using the leading twist approach (LTA) to nuclear shadowing, we calculate the
+ratios of diffractive and usual parton distributions for a heavy nucleus (Pb)
+and the proton, $R_{A/p}=(f_{i/A}^{D(3)}/f_{i/A})/(f_{i/p}^{D(3)}/f_{i/p})$,
+for coherent and summed (coherent plus quasi-elastic) nuclear deep-inelastic
+scattering. We find that $R_{A/p} \approx 0.5-1$ for quarks and $R_{A/p}
+\approx 0.5-1.3$ for gluons in a broad range of $x$, which reaffirms the
+difference from the nuclear enhancement of $R_{A/p}$ predicted in the gluon
+saturation framework. We demonstrate that the magnitude of $R_{A/p}$ is
+controlled by the cross section of the interaction of hadronic fluctuations of
+the virtual photon with target nucleons, which explains an enhancement of
+$R_{A/p}$ in the color dipole model and its suppression in LTA. We argue that
+the black disk limit of LTA corresponds to $R_{A/p}=1$ and $R^{\rm
+coh}_{A/p}=0.86$ for the summed and coherent scattering, respectively. Relying
+on an intuitive definition of the saturation scale, we show that the ratio of
+the saturation scales of a heavy nucleus and proton $Q_{sA}^2(b)/Q_{sp}^2(b)
+\approx 1$ at small impact parameters $b$ due to the strong leading twist
+nuclear shadowing and diluteness of the nuclear density.",2403.08342v1
+2006-02-02,Evolution of Rotating Molecular Cloud Core with Oblique Magnetic Field,"We studied the collapse of rotating molecular cloud cores with inclined
+magnetic fields, based on three-dimensional numerical simulations.The numerical
+simulations start from a rotating Bonnor-Ebert isothermal cloud in a uniform
+magnetic field. The magnetic field is initially taken to be inclined from the
+rotation axis. As the cloud collapses, the magnetic field and rotation axis
+change their directions. When the rotation is slow and the magnetic field is
+relatively strong, the direction of the rotation axis changes to align with the
+magnetic field, as shown earlier by Matsumoto & Tomisaka. When the magnetic
+field is weak and the rotation is relatively fast, the magnetic field inclines
+to become perpendicular to the rotation axis. In other words, the evolution of
+the magnetic field and rotation axis depends on the relative strength of the
+rotation and magnetic field. Magnetic braking acts to align the rotation axis
+and magnetic field, while the rotation causes the magnetic field to incline
+through dynamo action. The latter effect dominates the former when the ratio of
+the angular velocity to the magnetic field is larger than a critical value
+\Omega_0/ B_0 > 0.39 G^1/2 c_s^-1, where B_0, \Omega_0, G, and c_s^-1 denote
+the initial magnetic field, initial angular velocity, gravitational constant,
+and sound speed, respectively. When the rotation is relatively strong, the
+collapsing cloud forms a disk perpendicular to the rotation axis and the
+magnetic field becomes nearly parallel to the disk surface in the high density
+region. A spiral structure appears due to the rotation and the wound-up
+magnetic field in the disk.",0602034v1
+2017-02-06,The formation of magnetic depletions and flux annihilation due to reconnection in the heliosheath,"The misalignment of the solar rotation axis and the magnetic axis of the Sun
+produces a periodic reversal of the Parker spiral magnetic field and the
+sectored solar wind. The compression of the sectors is expected to lead to
+reconnection in the heliosheath (HS). We present particle-in-cell simulations
+of the sectored HS that reflect the plasma environment along the Voyager 1 and
+2 trajectories, specifically including unequal positive and negative azimuthal
+magnetic flux as seen in the Voyager data \citep{Burlaga03}. Reconnection
+proceeds on individual current sheets until islands on adjacent current layers
+merge. At late time bands of the dominant flux survive, separated by bands of
+deep magnetic field depletion. The ambient plasma pressure supports the strong
+magnetic pressure variation so that pressure is anti-correlated with magnetic
+field strength. There is little variation in the magnetic field direction
+across the boundaries of the magnetic depressions. At irregular intervals
+within the magnetic depressions are long-lived pairs of magnetic islands where
+the magnetic field direction reverses so that spacecraft data would reveal
+sharp magnetic field depressions with only occasional crossings with jumps in
+magnetic field direction. This is typical of the magnetic field data from the
+Voyager spacecraft \citep{Burlaga11,Burlaga16}. Voyager 2 data reveals that
+fluctuations in the density and magnetic field strength are anti-correlated in
+the sector zone as expected from reconnection but not in unipolar regions. The
+consequence of the annihilation of subdominant flux is a sharp reduction in the
+""number of sectors"" and a loss in magnetic flux as documented from the Voyager
+1 magnetic field and flow data \citep{Richardson13}.",1702.01697v1
+2020-07-23,Signal Enhancement for Magnetic Navigation Challenge Problem,"Harnessing the magnetic field of the Earth for navigation has shown promise
+as a viable alternative to other navigation systems. A magnetic navigation
+system collects its own magnetic field data using a magnetometer and uses
+magnetic anomaly maps to determine the current location. The greatest challenge
+with magnetic navigation arises when the magnetic field measurements from the
+magnetometer encompass the magnetic field from not just the Earth, but also
+from the vehicle on which it is mounted. It is difficult to separate the Earth
+magnetic anomaly field, which is crucial for navigation, from the total
+magnetic field reading from the sensor. The purpose of this challenge problem
+is to decouple the Earth and aircraft magnetic signals in order to derive a
+clean signal from which to perform magnetic navigation. Baseline testing on the
+dataset has shown that the Earth magnetic field can be extracted from the total
+magnetic field using machine learning (ML). The challenge is to remove the
+aircraft magnetic field from the total magnetic field using a trained model.
+This challenge offers an opportunity to construct an effective model for
+removing the aircraft magnetic field from the dataset by using a scientific
+machine learning (SciML) approach comprised of an ML algorithm integrated with
+the physics of magnetic navigation.",2007.12158v2
+2023-04-13,High-performance descriptor for magnetic materials: Accurate discrimination of magnetic structure,"The magnetic structure is crucial in determining the physical properties
+inherent in magnetic compounds. We present an adequate descriptor for magnetic
+structure with proper magnetic symmetry and high discrimination performance,
+which does not depend on artificial choices for coordinate origin, axis, and
+magnetic unit cell in crystal. We extend the formalism called ``smooth overlap
+of atomic positions'' (SOAP), providing a numerical representation of atomic
+configurations to that of magnetic moment configurations. We introduce the
+descriptor in terms of the vector spherical harmonics to describe a magnetic
+moment configuration and partial spectra from the expansion coefficients. We
+discuss that the lowest-order partial spectrum is insufficient to discriminate
+the magnetic structures with different magnetic anisotropy, and a higher-order
+partial spectrum is required in general to differentiate detailed magnetic
+structures on the same atomic configuration. We then introduce the fourth-order
+partial spectrum and evaluate the discrimination performance for different
+magnetic structures, mainly focusing on the difference in magnetic symmetry.
+The modified partial spectra that are defined not to reflect the difference of
+magnetic anisotropy are also useful in evaluating magnetic structures obtained
+from the first-principles calculations performed without spin-orbit coupling.
+We apply the present method to the symmetry-classified magnetic structures for
+the crystals of Mn$_3$Ir and Mn$_3$Sn, which are known to exhibit anomalous
+transport under the antiferromagnetic order, and examine the discrimination
+performance of the descriptor for different magnetic structures on the same
+crystal.",2304.06282v2
+2023-08-25,Coexistence of non-trivial van der Waals magnetic orders enable field-free spin-orbit torque switching at room temperature,"The discovery of van der Waals (vdW) materials exhibiting non-trivial and
+tunable magnetic interactions at room temperature can give rise to exotic
+magnetic states, which are not readily attainable with conventional materials.
+Such vdW magnets can provide a unique platform for studying new magnetic
+phenomena and realising magnetization dynamics for energy-efficient and
+non-volatile spintronic memory and logic technologies. Recent developments in
+vdW magnets have revealed their potential to enable spin-orbit torque (SOT)
+induced magnetization dynamics. However, the deterministic and field-free SOT
+switching of vdW magnets at room temperature has been lacking, prohibiting
+their potential applications. Here, we demonstrate magnetic field-free and
+deterministic SOT switching of a vdW magnet (Co0.5Fe0.5)5GeTe2 (CFGT) at room
+temperature, capitalizing on its non-trivial intrinsic magnetic ordering. We
+discover a coexistence of ferromagnetic and antiferromagnetic orders in CFGT at
+room temperature, inducing an intrinsic exchange bias and canted perpendicular
+magnetism. The resulting canted perpendicular magnetization of CFGT introduces
+symmetry breaking, facilitating successful magnetic field-free magnetization
+switching in the CFGT/Pt heterostructure devices. Furthermore, the SOT-induced
+magnetization dynamics and their efficiency are evaluated using 2nd harmonic
+Hall measurements. This advancement opens new avenues for investigating tunable
+magnetic phenomena in vdW material heterostructures and realizing field-free
+SOT-based spintronic technologies.",2308.13408v1
+2001-06-05,On Nonlinear Alfvén Waves Generated by Cosmic Ray Streaming Instability,"Nonlinear damping of parallel propagating Alfv\'en waves in high-$\beta$
+plasma is considered. Trapping of thermal ions and Coulomb collisions are taken
+into account. Saturated damping rate is calculated. Applications are made for
+cosmic ray propagation in the Galaxy.",0106078v1
+2005-01-05,The Impact of Gravitational Redshift on Systemic Water Maser Emission in NGC 4258,"NGC 4258 is well known for its 22 GHz water maser features that appear to
+reside in a thin Keplerian disk orbiting at R_0=0.13 pc. The influence of
+gravitational redshift on the level of maser saturation and the line strength
+and width of systemic water maser emission is studied. The effective
+gravitational velocity shift along the gain path through the disk amounts to
+about twice the thermal velocity width of H2O molecules at 500 K for a masing
+ring of thickness 0.2R_0. This GR induced frequency shift has a sign opposite
+to the shift caused by the projected velocity difference vector of Keplerian
+motion on the blue side of the systemic maser emission and has the same sign on
+the red systemic side. Consequently, the negative optical depth that a line
+photon sees as it traverses the masing disk along a path of minimal Keplerian
+velocity gradient is larger on the blue side. Note that one is not concerned
+here with an overall shift in the maser spectrum caused by the fact that the
+masing ring as a whole is located in the black hole's potential well, i.e., it
+is the change in the gravitational potential along the gain path that matters.
+It is found, for a Schwarzschild metric, that saturation is enhanced
+(suppressed) for systemic blue-shifted (red-shifted) maser features by
+gravitational redshift of line photons. Approaching peak flux systemic features
+are, on average, brighter, due to saturation, and wider (~2 km/s), due to
+rebroadening, than their receding counterparts (~1 km/s). The effects are
+consistent with observations that span several years, i.e., over periods longer
+than needed for disk material to move through the systemic emission region.
+Further confirmation of this effect can follow by combining all available
+systemic 22 GHz data over the past two decades (abridged).",0501069v2
+2005-05-18,The Large-Scale Electrochemistry and Possible Consequences of Deep Impact Mission to Tempel 1,"Some consequences of hypervelocity impact onto the comet Tempel 1 nucleus are
+considered under assumption that SP comets are fragments of massive icy
+envelopes of Ganymede-like bodies saturated by products of ice electrolysis
+that underwent global explosions.",0505377v3
+1996-09-20,Variationnal study of ferromagnetism in the t1-t2 Hubbard chain,"A one-dimensional Hubbard model with nearest and (negative) next-nearest
+neighbour hopping is studied variationally. This allows to exclude saturated
+ferromagnetism for $U < U_c$. The variational boundary $U_c (n)$ has a minimum
+at a ``critical density'' $n_c$ and diverges for $n \rightarrow 1$.",9609198v1
+1999-02-17,Trapping and Mobilization of Residual Fluid During Capillary Desaturation in Porous Media,"We discuss the problem of trapping and mobilization of nonwetting fluids
+during immiscible two phase displacement processes in porous media. Capillary
+desaturation curves give residual saturations as a function of capillary
+number. Interpreting capillary numbers as the ratio of viscous to capillary
+forces the breakpoint in experimental curves contradicts the theoretically
+predicted force balance. We show that replotting the data against a novel
+macroscopic capillary number resolves the problem for discontinuous mode
+displacement.",9902236v1
+1999-09-09,Mesoscopic fluctuations of the Coulomb drag,"We consider mesoscopic fluctuations of the Coulomb drag coefficient $\rho_D$
+in the system of two separated two-dimensional electron gases. It is shown that
+at low temperatures sample to sample fluctuations of $\rho_D$ exceed its
+ensemble average. It means that in such a regime the sign of $\rho_D$ is random
+and the temperature dependence almost saturates $\rho_D \sim 1/\sqrt{T}$.",9909133v1
+2000-02-13,Phase-coherence time saturation in mesoscopic systems: wave function collapse,"A finite phase-coherence time $\tau_{\phi}^{meas}$ emerges from iterative
+measurement onto a quantum system. For a rapid sequence, the phase-coherence
+time is found explicitly. For the stationary charge conduction problem, it is
+bounded. At all order, in the time-interval of measurements, we propose a
+general expression for $\tau_{\phi}^{meas}$.",0002188v1
+2002-04-02,Fast crack propagation by surface diffusion,"We present a continuum theory which describes the fast growth of a crack by
+surface diffusion. This mechanism overcomes the usual cusp singularity by a
+self-consistent selection of the crack tip radius. It predicts the saturation
+of the steady state crack velocity appreciably below the Rayleigh speed and tip
+blunting. Furthermore, it includes the possibility of a tip splitting
+instability for high applied tensions.",0204056v1
+2002-10-10,Dephasing from interactions and spin disorder,"We calculate the dephasing rate of the electrons in the presence of
+interactions and elastic spin disorder scattering. In the frame of a
+self-consistent diagrammatic treatment, we obtain saturation of the dephasing
+rate in the limit of zero temperature for spin-orbit disorder in 2 dimensions.
+This result is in agreement with relevant experiments.",0210223v1
+2003-04-12,An extension of Tasaki's flat-band Hubbard model,"We present a new class of flat-band Hubbard models which have saturated
+ferromagnetic ground states at two distinct electron numbers for different
+values of parameters. The models are extensions of Tasaki's flat-band models.",0304295v4
+2005-11-20,Tension-Induced Morphological Transition in Mixed Lipid Bilayers,"Recently, Rozovsky et al. reported on the morphology and dynamics of
+superstructures in three-component lipid bilayers containing saturated and
+unsaturated lipids as well as cholesterol [J. Am. Chem. Soc. 127, 36 (2005)].
+We comment that the observed sequence of the stripe to hexagonal morphological
+transition in mixed bilayers can be attributed to an enhanced membrane surface
+tension that is induced by the vesicle adhesion on the solid surface.",0511492v1
+1997-06-17,Partial Representations and Amenable Fell Bundles over Free Groups,"We show that a Fell bundle B = {B_t}_{t \in F}, over an arbitrary free group
+F, is amenable, whenever it is orthogonal (in the sense that B_x^* B_y = 0, if
+x and y are distinct generators of F) and semi-saturated (in the sense that
+B_{ts} coincides with the closed linear span of B_t B_s, when the
+multiplication ``ts'' involves no cancelation).",9706001v1
+2004-06-09,A toy model for the coincidence problem,"The measured values of the matter energy density and the vacuum energy
+density are obtained using an adiabatic black hole percolating model at the
+critical point. The percolation of black holes is related with an expanding
+isotropic universe filled with the most entropic fluid saturating the
+holographic bound.",0406035v2
+1993-10-25,Hadron Production Ratios as Probes of Confinement and Freeze-Out,"Particle production in central S-A collisions at 200 GeV/A energy is analysed
+within a thermal model. Present data imply that the strange particles freeze
+out at a higher temperature than the non-strange particles and that the
+strangeness saturation is incomplete.",9310345v1
+1999-05-13,Drell-Hearn-Gerasimov Sum Rule for the Nucleon in the Large-N_c Limit,"We show that the Drell-Hearn-Gerasimov sum rule for the nucleon is entirely
+saturated by the \Delta resonance in the limit of a large number of colors, N_c
+\to \infty. Corrections are at relative order 1/N_c^2.",9905334v1
+2000-10-24,Low x Physics,"This is a talk, given at Diffraction'2000, Sept. 2 - 7, Centraro, Italy. In
+this talk, we present the arguments, that a new QCD regime - gluon saturation,
+has been reached at HERA.",0010272v1
+2000-11-01,Introduction to Diffractive Photoprocesses,"The objectives of my talk are to provide a very brief introduction to
+diffractive photoprocesses in general and the colour dipole model in
+particular; and to comment on possible gluon saturation effects at HERA and
+beyond.",0011007v1
+2001-05-31,Effective field theory for the small-x evolution,"The small-x behavior of structure functions in the saturation region is
+determined by the non-linear generalization of the BFKL equation. I suggest the
+effective field theory for the small-x evolution which solves formally this
+equation. The result is the 2+1 functional integral for the structure functions
+at small x.",0105334v1
+2001-11-29,Particle Production in High-energy Heavy-ion Collisions,"Particle production mechanisms in high-energy heavy-ion collisions are
+reviewed in connection with recent experimental data from RHIC. Implications on
+mini-jet production, parton saturation and jet quenching are discussed.",0111404v1
+2001-11-30,pQCD at the Kinematical Boundary of its Applicability,"I examines the applicability and possible need for a re-formulation of pQCD,
+as we know it, in the DIS limit of small $Q^2$ and $x$. Gluon saturation,
+implied by s-channel unitarity, and its possible experimental signatures are
+critically assessed.",0111453v1
+2002-02-25,High Energy QCD and the Large Nc Limit,"We review recent progress in understanding QCD at high energies and the role
+played in it by the large Nc limit. We discuss unitarization of total hadronic
+cross sections and saturation of structure functions at high energies.",0202238v1
+2002-06-10,"Chiral Lagrangian from gauge invariant,nonlocal, dynamical quark model","Parameters of Gasser Leutwyler chiral Lagrangian are proved saturated by
+dynamical quark self energy Sigma(k^2) in a gauge invariant, nonlocal,
+dynamical quark model.",0206090v2
+2002-08-29,Taming the BFKL Intercept via Gluon Saturation,"We show that the inclusion of parton density effects in the perturbative
+small-x evolution reduces the strength of the powerlike growth of total
+hadronic cross sections.",0208265v1
+2002-09-10,Dynamics of Particle Production in Relativistic Nuclear Collisions,"Saturation models for particle production in relativistic nuclear collisions
+are discussed. In particular, I show that the predictions from the high density
+QCD for the qualitative shape of $dN/dy$ are very sensitive to the form of the
+unintegrated gluon distribution.",0209102v1
+2002-12-11,Selected Topics in Rapidity Gap Physics,"This talk will review selected topics in rapidity gap physics. In particular
+I will discuss diffractive jet production and the possibility of searching for
+the higgs boson using diffraction at the LHC; the dipole picture of diffraction
+and saturation; and those processes where a large momentum is transferred
+across the rapidity gap, for which there has been recent progress both
+experimentally and theoretically.",0212154v1
+2003-09-11,QCD Saturation and Soft Processes,"We show that an approximate solution to the amended non-linear
+Balitsky-Kovchegov evolution equation which was formulated for hard QCD
+processes, can be extended to provide a good description of photoproduction and
+soft hadronic (non perturbative) reactions.",0309125v1
+2003-12-03,Beyond BFKL,"The Balitsky-Fadin-Kuraev-Lipatov (BFKL) evolution equation is known to be
+``unstable'' with respect to fluctuations in gluon virtuality, transverse
+momentum and energy requiring to go beyond the leading order BFKL. Still, these
+instabilities point to fruitful improvements of our deep understanding of QCD.
+Recent applications to next-leading order and to saturation problems are
+outlined.",0312043v1
+2004-04-22,Predicting F2D3 from the colour glass condensate model,"We confront the colour glass condensate motivated dipole model
+parameterization of Iancu, Itakura and Munier with the available HERA data on
+the diffractive structure function F2D3 and with existing dipole model
+parameterizations. Reasonably good agreement is found with only two adjustable
+parameters. We caution against interpreting the success of the model as
+compelling evidence for low-x perturbative saturation dynamics.",0404192v1
+2004-08-03,Diffractive photon dissociation in the saturation regime,"Using the Good and Walker picture, we derive a simple formula for diffractive
+dissociation that can apply to recent data collected at HERA in the low Q2
+regime.",0408038v1
+2004-08-03,"Color Glass Condensate at the LHC: hadron multiplicities in $pp$, $pA$ and $AA$ collisions","We make quantitative predictions for the rapidity and centrality dependencies
+of hadron multiplicities in $AA$, $pA$ and $pp$ collisions at the LHC energies
+basing on the ideas of parton saturation in the Color Glass Condensate.",0408050v1
+2004-08-31,Small x QCD,"A review of some theoretical aspects of small x QCD physics is given, with a
+particular emphasis to the relation between the BFKL and the colour dipole
+approaches. The nonlinear evolution equations one may construct, as a better
+approximation beyond the linear analysis, are discussed together with their
+relation to a possible saturation regime.",0408352v1
+2005-05-27,Parametric form of QCD travelling waves,"We derive parametric travelling-wave solutions of non-linear QCD equations.
+They describe the evolution towards saturation in the geometric scaling region.
+The method, based on an expansion in the inverse of the wave velocity, leads to
+a solvable hierarchy of differential equations. A universal parametric form of
+travelling waves emerges from the first two orders of the expansion.",0505237v1
+2005-07-13,"Saturation, traveling waves and fluctuations","In this talk I discuss the high energy asymptotics of QCD scattering, and its
+similarity to a reaction-diffusion process. I also discuss detailed numerical
+studies of the mean field approximation to this picture, i.e., the
+Balitsky-Kovchegov equation.",0507153v1
+2005-11-14,Limiting energy dependence of spin parameters in small-angle elastic pp-scattering,"We consider limiting behavior with energy of spin parameters at small values
+of t close to zero which corresponds to the saturation of the Froissart-Martin
+bound for the total cross sections.",0511163v3
+2006-08-18,Nuclear matter in the chiral quark soliton model with vector mesons,"We study the nuclear matter solution in the chiral quark soliton model
+coupled to $\rho$ and $\omega$ vector mesons based on the Wigner-Seitz
+approximation. It is shown that the vector mesons stabilize the soliton at
+high-density region. As a result, the saturation property and incompressibility
+are significantly improved.",0608197v1
+2006-09-25,High energy pA collisions in the Color Glass Condensate approach,"We present a brief review of phenomenological applications of the gluon
+saturation approach to the proton-nucleus collisions at high energies.",0609258v2
+2006-11-21,Diffraction 2006: Theoretical Summary,"This paper presents a summary of the theoretical presentations to the
+international workshop ""Diffraction 2006"". The range of topics covered during
+the workshop was quite broad and this summary is therefore somewhat selective
+covering recent developments in BFKL physics, exclusive processes, saturation
+dynamics, DIS and structure functions and coherence in QCD.",0611275v1
+1995-05-03,A Stringy Test of the Fate of the Conifold,"By studying string loop corrections to superpotential of type II strings
+compactified on Calabi-Yau threefolds we find a quantum stringy test and a
+confirmation of a recent proposal of Strominger on the fate of the conifold
+singularity. We also propose a connection between the spectrum of Bogomolnyi
+saturated solitons and one-loop string partition function of $N=2$ topological
+strings.",9505023v1
+1996-03-06,Gravitating BPS Dyons witout a Dilaton,"We describe curved-space BPS dyon solutions, the ADM mass of which saturates
+the gravitational version of the Bogomol'nyi bound. This generalizes
+self-gravitating BPS monopole solutions of Gibbons et al. when there is no
+dilaton.",9603027v1
+1996-12-11,Introduction to Supersymmetry,"These lectures give a self-contained introduction to supersymmetry from a
+modern perspective. Emphasis is placed on material essential to understanding
+duality. Topics include: central charges and BPS-saturated states,
+supersymmetric nonlinear sigma models, N=2 Yang-Mills theory, holomorphy and
+the N=2 Yang-Mills beta function, supersymmetry in 2, 6, 10, and 11 spacetime
+dimensions.",9612114v1
+1997-12-08,BPS Saturated Amplitudes and Non-perturbative String Theory,"The study of the special F^4 and R^4 in the effective action for the
+Spin(32)/Z_2 and type II strings sheds some light on D-brane calculus and on
+instanton contribution counting. The D-instanton case is discussed separately.",9712079v3
+1999-09-29,On The Size of The Graviton,"We propose an approximate wavefunction of the bound state of $N$ $D0$-branes.
+Its spread grows as $N^{1\over 3}$ per particle, i.e. it saturates the
+Polchinski's bound.",9909213v3
+1999-11-08,The Contribution of Instanton-Antiinstanton Fluctuations to the Ground State Energy in Supersymmetric Quantum Mechanical Models,"I show that the method of finding if the ground state energy is nonzero or
+not by saturating the functional integral directly with
+instanton-anti-instanton type fluctuations is not reliable either for the
+double or for the triple well potential models in supersymmetric quantum
+mechanics.",9911050v1
+2002-08-22,On uncertainty relations in noncommutative quantum mechanics,"We discuss the uncertainty relations in quantum mechanics on noncommutative
+plane. In particular, we show that, for a given state at most one out of three
+basic nontrivial uncertainty relations can be saturated. We consider also in
+some detail the case of angular momentum eigenstates.",0208162v2
+2003-11-19,Universality of the shear viscosity in supergravity,"Kovtun, Son and Starinets proposed a bound on the shear viscosity of any
+fluid in terms of its entropy density. We argue that this bound is always
+saturated for gauge theories at large 't Hooft coupling, which admit
+holographically dual supergravity description.",0311175v1
+1994-09-02,Projective Stationary Sets and Strong Reflection Principle,"We study projective stationary sets. The Projective Stationary Reflection
+principle is the statement that every projective stationary set contains an
+increasing continuous $\in$--chain of length $\omega_1$. We show that if
+Martin's Maximum holds, then the Projective Stationary Reflection Principle
+holds. Also it is equivalent to the Strong Reflection Principle. We show that
+the saturation of the nonstationary ideal on $\omega_1$ is equivalent to a
+certain kind of reflection.",9409202v1
+1996-01-15,"Saturated filters at successors of singulars, weak reflection and yet another weak club principle","Suppose that lambda is the successor of a singular cardinal mu whose
+cofinality is an uncountable cardinal kappa. We give a sufficient condition
+that the club filter of lambda concentrating on the points of cofinality kappa
+is not lambda^+-saturated. The condition is phrased in terms of a notion that
+we call weak reflection. We discuss various properties of weak reflection",9601219v1
+1998-08-29,Polycyclic-by-finite group algebras are catenary,"We show that group algebras kG of polycyclic-by-finite groups G, where k is a
+field, are catenary: Given prime ideals P and P' of kG, with P contained in P',
+all saturated chains of primes between P and P' have the same length.",9808123v1
+2000-10-23,Recent Progress in Algebraic Combinatorics,"A survey of recent progress in three areas of algebraic combinatorics: (1)
+the Saturation Conjecture for Littlewood-Richardson coefficients, (2) the n!
+and (n+1)^{n-1} conjectures, and (3) longest increasing subsequences of
+permutations.",0010218v2
+2003-03-02,Quantum Generalization of the Horn Conjecture,"We prove a theorem which implies a quantum (multiplicative) analogue of the
+Horn conjecture, and also of the saturation conjecture. We obtain
+transversality statements for quantum schubert calculus in any characteristic
+and also determine the smallest power of q in an arbitrary (small quantum)
+product of Schubert varieties in a Grassmannian.",0303013v4
+2003-05-08,Regularity and Saturation in Biprojective Spaces,"The paper is being withdrawn since the results are incorporated in paper
+arxiv.org/abs/math.AG/0306195.",0305125v4
+2005-08-29,"Base point free theorems--saturation, b-divisors, and canonical bundle formula--","We reformulate base point free theorems. Our formulation is flexible and has
+some important applications. One of the main purposes of this paper is to prove
+a generalization of the base point free theorem in Fukuda's paper: On
+numerically effective log canonical divisors.",0508554v3
+2006-01-10,About one singularity of the property of disturbed differential systems equivalence to linear differential equations,"In this paper we consider the families of morphisms of vector fibre bundles
+(\cite{Mill1}) defined by the linear systems of differential equations. We
+proving that the specified families of morphisms is not saturated
+(\cite{Mill2}).",0601212v1
+2006-01-11,About one characteristic of set of linear differential systems with non-negative coefficients,"The families of morphisms of vector fibre bundle (\cite{Mill1}) defined by
+the linear systems of differential equations with non-negative coefficients is
+considered. Authors proved that the specified families of morphisms is not
+saturated (\cite{Mill2}).",0601241v1
+2006-01-11,About one characteristic of set of linear Hamiltonian systems,"The families of morphisms of vector fibre bundle (\cite{Mill1}) defined by
+the linear Hamiltonian systems of differential equations is considered. Authors
+proved that the specified families of morphisms is not saturated
+(\cite{Mill2}).",0601244v1
+2006-01-19,"About one singularity of the property of disturbed differential systems, that equivalents to linear differential equations","This paper is devoted to the study of the family of morphisms of vector
+bundle, defined by the systems equivalence to linear differential equations. It
+is proved, that the specified families of the morphisms of vector bundle is not
+saturated.",0601461v1
+2007-02-15,Model theory and Kaehler geometry,"We survey and explain some recent work at the intersection of model theory
+and bimeromorphic geometry (classification of compact complex manifolds).
+Included here are the essential saturation of the many sorted structure
+$\mathcal{C}$ of compact Kaehler manifolds, the conjectural role of
+hyperkaehler manifolds in the description of strongly minimal sets in
+$\mathcal{C}$ and Campana's work on the isotriviality of hyperkaehler families
+and its connection with the nonmultidimensionality conjecture.",0702468v1
+2003-03-04,Quadratic solitons as nonlocal solitons,"We show that quadratic solitons are equivalent to solitons of a nonlocal Kerr
+medium. This provides new physical insight into the properties of quadratic
+solitons, often believed to be equivalent to solitons of an effective saturable
+Kerr medium. The nonlocal analogy also allows for novel analytical solutions
+and the prediction of novel bound states of quadratic solitons.",0303003v1
+1998-06-05,Alternative Linear Chiral Models for Nuclear Matter,"The equation of state of a family of alternative linear chiral models in the
+mean field approximation is discussed. We investigate the analogy between some
+of these models with current models in the literature, and we show that it is
+possible to reproduce very well the saturation properties of nuclear matter.",9806020v1
+1999-09-15,Saturation of the width of the strength function,"The strength function of a single state $|d>$ is studied using the deformed
+Gaussian orthogonal ensemble. In particular we study the dependence of the
+spreading width of $|d>$ on the degree of mixing.",9909033v1
+2000-01-31,Nuclear Saturation with QCD sum rules,"The scalar and vectorial self energies obtained through QCD sum rules are
+introduced in the Quantum Hadrodynamics (QHD) equations. This QHD and QCD
+mixing show us that the effect of the density on the coupling constants is very
+small.",0001065v2
+2002-04-12,Nuclear matter with off-shell propagation,"Symmetric nuclear matter is studied within the conserving, self-consistent
+T-matrix approximation. This approach involves off-shell propagation of
+nucleons in the ladder diagrams. The binding energy receives contributions from
+the background part of the spectral function, away form the quasiparticle peak.
+The Fermi energy at the saturation point fulfills the Hugenholz-Van Hove
+relation. In comparison to the Brueckner-Hartree-Fock approach, the binding
+energy is reduced and the equation of state is harder",0204034v1
+2003-01-07,Introduction: GDH and related topics,"The formulation of the Gerasimov-Drell-Hearn sum rule is revisited, showing
+its connection with other sum rules occurring in electron scattering and
+discussing the problem of its saturation, both from the theoretical and
+experimental point of v iew. The generalisation to other nuclear targets is
+also reported.",0301014v1
+2007-03-22,Rapidity dependence of the photon to pion production ratio in high energy collisions,"We investigate rapidity dependence of the ratio of photon and pion production
+cross sections in high energy proton (deuteron) - nucleus collisions at RHIC
+and LHC. This ratio, and its rapidity dependence can be a sensitive probe of
+high density QCD (Color Glass Condensate) dynamics and shed further light on
+the role of saturation physics at RHIC and LHC.",0703069v1
+2001-09-04,Biot's theory of propagation of elastic waves in a fluid-saturated porous solid revisited: introduction of non-zero boundary slip velocity,"This paper has been withdrawn by the author due to the physically
+inconsistent assumption of constant slip velocity, instead, see a new improved
+model - physics/0201045.",0109007v2
+2005-11-01,Ultraslow light in inhomogeneously broadened media,"We calculate the characteristics of ultraslow light in an inhomogeneously
+broadened medium. We present analytical and numerical results for the group
+delay as a function of power of the propagating pulse. We apply these results
+to explain the recently reported saturation behavior [Baldit {\it et al.}, \prl
+{\bf 95}, 143601 (2005)] of ultraslow light in rare earth ion doped crystal.",0511002v1
+2006-04-07,Enhanced production of coherent pulsed radiation at 125 nm: the route towards a tabletop VUV laser,"A novel approach is used to enhance by nearly two orders of magnitude the
+conversion efficiency of a 125 nm-coherent source, based on four-wave mixing in
+room-temperature mercury vapor. Saturation issues are observed and discussed.",0604054v1
+2006-04-10,Superluminal pulse reflection from a weakly absorbing dielectric slab,"Group delay for a reflected light pulse from a weakly absorbing dielectric
+slab is theoretically investigated, and large negative group delay is found for
+weak absorption near a resonance of the slab ($Re(kd)=m\pi$). The group delays
+for both the reflected and transmitted pulses will be saturated with the
+increase of the absorption.",0604074v1
+2006-04-20,Optimal dense coding with arbitrary pure entangled states,"We examine dense coding with an arbitrary pure entangled state sharing
+between the sender and the receiver. Upper bounds on the average success
+probability in approximate dense coding and on the probability of conclusive
+results in unambiguous dense coding are derived. We also construct the optimal
+protocol which saturates the upper bound in each case.",0604149v2
+2007-05-15,Forward hadron production in high energy pA collisions: from RHIC to LHC,"We present a calculation of Pi, D and B mesons production at RHIC and LHC
+energies based upon the KKT model of gluon saturation. We discuss dependence of
+the nuclear modification factor on rapidity and transverse momentum.",0705.2193v2
+2007-05-16,Near-Extreme Black Holes and the Universal Relaxation Bound,"A fundamental bound on the relaxation time \tau of a perturbed
+thermodynamical system has recently been derived, \tau \geq \hbar/\pi T, where
+$T$ is the system's temperature. We demonstrate analytically that black holes
+saturate this bound in the extremal limit and for large values of the azimuthal
+number m of the perturbation field.",0705.2306v1
+2007-06-13,Recent developments in small-x physics,"Recent theoretical progress in understanding high-energy scattering beyond
+the mean field approximation is reviewed. The role of Lorentz invariance and
+pomeron loops in the evolution, the relation between high-energy QCD and
+statistical physics and results for the saturation momentum and the scattering
+amplitude are discussed.",0706.1866v1
+2007-06-21,Stochastic Lorentz forces on a point charge moving near the conducting plate,"The influence of quantized electromagnetic fields on a nonrelativistic
+charged particle moving near a conducting plate is studied. We give a
+field-theoretic derivation of the nonlinear, non-Markovian Langevin equation of
+the particle by the method of Feynman-Vernon influence functional. This
+stochastic approach incorporates not only the stochastic noise manifested from
+electromagnetic vacuum fluctuations, but also dissipation backreaction on a
+charge in the form of the retarded Lorentz forces. Since the imposition of the
+boundary is expected to anisotropically modify the effects of the fields on the
+evolution of the particle, we consider the motion of a charge undergoing
+small-amplitude oscillations in the direction either parallel or normal to the
+plane boundary. Under the dipole approximation for nonrelativistic motion,
+velocity fluctuations of the charge are found to grow linearly with time in the
+early stage of the evolution at the rather different rate, revealing strong
+anisotropic behavior. They are then asymptotically saturated as a result of the
+fluctuation-dissipation relation, and the same saturated value is found for the
+motion in both directions. The observational consequences are discussed. plane
+boundary. Velocity fluctuations of the charge are found to grow linearly with
+time in the early stage of the evolution at the rate given by the relaxation
+constant, which turns out to be smaller in the parallel case than in the
+perpendicular one in a similar configuration. Then, they are asymptotically
+saturated as a result of the fluctuation-dissipation relation. For the
+electron, the same saturated value is obtained for motion in both directions,
+and is mainly determined by its oscillatory motion. Possible observational
+consequences are discussed.",0706.3075v3
+2007-06-28,Shear Viscosity to Entropy within a Parton Cascade,"The shear viscosity is calculated by means of the perturbative kinetic
+partonic cascade BAMPS with CGC initial conditons for various saturation
+momentum scale Q_s. eta/s ~ 0.15 stays approximately constant when going from
+RHIC to LHC.",0706.4212v1
+2007-06-29,Investigating the extended geometric scaling region at LHC with polarized and unpolarized final states,"We present predictions for charged hadron production and Lambda polarization
+in p-p and p-Pb collisions at the LHC using the saturation inspired DHJ model
+for the dipole cross section in the extended geometric scaling region.",0706.4430v1
+2007-07-12,Maltsiniotis's first conjecture for K_1,"We show that K_1 of an exact category agrees with K_1 of the associated
+triangulated derivator. More generally we show that K_1 of a Waldhausen
+category with cylinders and a saturated class of weak equivalences coincides
+with K_1 of the associated right pointed derivator.",0707.1892v2
+2007-08-26,Orbit semigroups and the representation type of quivers,"We show that a finite, connected quiver Q without oriented cycles is a Dynkin
+or Euclidean quiver if and only if all orbit semigroups of representations of Q
+are saturated.",0708.3413v2
+2007-09-02,Saturation effects in elastic scattering at the LHC,"The problems linked to the extraction of the basic parameters of the hadron
+elastic scattering amplitude at the LHC are explored. The impact of the Black
+Disk Limit (BDL)$-$ which constitutes a new regime of the scattering processes
+  - on the determination of these values is examined.",0709.0100v1
+2007-11-15,Cohomology of groups in o-minimal structures: acyclicity of the infinitesimal subgroup,"By recent work on some conjectures of Pillay, each definably compact group in
+a saturated o-minimal structure is an expansion of a compact Lie group by a
+torsion free normal divisible subgroup, called its infinitesimal subgroup. We
+show that the infinitesimal subgroup is cohomologically acyclic. This implies
+that the functorial correspondence between definably compact groups and Lie
+groups preserves the cohomology.",0711.2502v1
+2007-11-22,Spectral saturation: inverting the spectral Turan theorem,"We prove that if the spectral radius of a graph G of order n is larger than
+the spectral radius of the r-partite Turan graph of the same order, then G
+contains various supergraphs of the complete graph of order r+1. In particular
+G contains a complete r-partite graph of size log n with one edge added to the
+first part. These results complete a project of Erdos from 1963. We also give
+corresponding stability results.",0711.3488v1
+2008-02-21,Palindromic Saturation,"We consider two {seemingly} different definitions of infinite words which
+contain {the} utmost number of palindromes. We show that these two definitions
+coincide. {The keynote of the proof is a meticulous inspection of properties of
+complete return words and the application of some basic graph theory.} In fact,
+we provide another proof of the result announced in \cite{Zamboni}.",0802.2995v2
+2008-05-22,Bedforms in a turbulent stream.Part 2: Formation of ripples by primary linear instability and of dunes by non-linear pattern coarsening,"It is widely accepted that both ripples and dunes form in rivers by primary
+linear instability, the wavelength of the former scaling on the grain size,
+that of the latter being controled by the water depth. We revisit here this
+problem, using the computation of the turbulent flow over a wavy bottom
+performed in Part 1. The details of the different mechanisms controlling
+sediment transport are encoded into three quantities: the saturated flux, the
+saturation length and the threshold shear stress. Theses quantities are
+modelled in the case of erosion and momentum limited bed loads. This framework
+allows to give a clear picture of the instability in terms of dynamical
+mechanisms. The relation between the wavelength at which ripples form and the
+flux saturation length is quantitatively derived. Inverting the problem,
+experimental data is used to determine the saturation length as a function of
+grain size and shear velocity. Finally, using the systematic expansion of the
+flow field with respect to the corrugation amplitude, we discuss the non-linear
+selection of ripple aspect ratio. Investingating the effect of a free surface
+on the linear instability, we show that the excitation of standing waves at the
+surface has a stabilising effect, independently of the details of the flow and
+sediment transport models. Consequently, the shape of the dispersion relation
+is such that dunes can not result from a primary linear instability. We present
+the results of field experiments performed in the natural sandy Leyre river,
+which evidence the formation of ripples by a linear instability and the
+formation of dunes by a non-linear pattern coarsening limited by the free
+surface. We show that mega-dunes form when the sand bed presents
+heterogeneities such as a wide distribution of grain sizes.",0805.3417v2
+2008-05-30,"The ""footprints'' of irreversibility","We reformulate the result for the entropy production given in Phys. Rev.
+Lett. 98, 080602 (2007) in terms of the relative entropy of microscopic
+trajectories. By a combination with the Crook's theorem, we identify the path
+variables that are sufficient to fully identify irreversibility. We show that
+work saturates the relative entropy, and derive the entropy production for
+stochastic descriptions.",0805.4703v1
+2008-06-17,"Open Letter to the OSA Topical Meeting ""Slow and Fast Light""","The question is raised about whether the pulse delay in a saturable absorber
+has anything to do with the ""slow light"" and group velocity reduction. We also
+wonder why the 40-years-old trivial interpretation of the effect remains so far
+ignored.",0806.2732v1
+2008-07-27,Formation of aeolian ripples and sand sorting,"We present a continuous model capable of demonstrating some salient features
+of aeolian sand ripples: the realistic asymmetric ripple shape, coarsening of
+ripple field at the nonlinear stage of ripple growth, saturation of ripple
+growth for homogeneous sand, typical size segregation of sand and formation of
+armoring layers of coarse particles on ripple crests and windward slopes if
+sand is inhomogeneous.",0807.4284v2
+2008-10-19,Reflective Scattering and Unitarity,"Interpretation of unitarity saturation as reflective scattering is discussed.
+Analogies with optics and Berry phase alongside with the experimental
+consequences of the proposed interpretation at the LHC energies are considered.",0810.3391v1
+2008-10-21,Tunnelling for Large N,"In this brief note, by applying the stochastic approach to multiple fields,
+we estimate the probability of tunneling between vacua in a landscape with
+$\cal N$ fields. We find that the probability can be enhanced by large $\cal
+N$. When $\cal N$ saturates the dS entropy of some vacuum, the corresponding
+vacuum will be extremely unstable and be expected to rapidly decay. We discuss
+the implications of this result.",0810.3654v1
+2008-11-26,Features of elastic scattering at small t at the LHC,"The problems linked with the extraction of the basic parameters of the hadron
+elastic scattering amplitude at the LHC are explored. It is shown that one
+should take into account the saturation regime which will lead to new effects
+at the LHC.",0811.4369v1
+2009-01-26,Have we seen anything beyond (N)NLO DGLAP at HERA?,"The evidence from HERA for parton saturation, and other low-$x$ effects
+beyond the conventional DGLAP formalism, is recalled and critically reviewed in
+the light of new data and analyses presented at the conference.",0901.4001v1
+2009-02-02,From nuclear matter to Neutron Stars,"Neutron stars are the most dense objects in the observable Universe and
+conventionally one uses nuclear theory to obtain the equation of state (EOS) of
+dense hadronic matter and the global properties of these stars. In this work,
+we review various aspects of nuclear matter within an effective Chiral model
+and interlink fundamental quantities both from nuclear saturation as well as
+vacuum properties and correlate it with the star properties.",0902.0262v1
+2009-03-05,The Dynamics of EEG Entropy,"EEG time series are analyzed using the diffusion entropy method. The
+resulting EEG entropy manifests short-time scaling, asymptotic saturation and
+an attenuated alpha-rhythm modulation. These properties are faithfully modeled
+by a phenomenological Langevin equation interpreted within a neural network
+context.",0903.1078v1
+2009-04-29,"Comment on ""An optimized potential for carbon dioxide"" [J. Chem. Phys. 122, 214507 (2005)]","A molecular model for carbon dioxide is assessed regarding vapor-liquid
+quilibrium properties.Large deviations, being above 15 %, are found for vapor
+pressure and saturated vapor density in the entire temperature range.",0904.4622v1
+2009-05-07,Bernstein polynomials and spectral numbers for linear free divisors,"We discuss Bernstein polynomials of reductive linear free divisors. We define
+suitable Brieskorn lattices for these non-isolated singularities, and show the
+analogue of Malgrange's result relating the roots of the Bernstein polynomial
+to the residue eigenvalues on the saturation of these Brieskorn lattices.",0905.0971v4
+2009-05-07,Exclusive vector meson production in electron-ion collisions,"We calculate the nuclear cross section for coherent and incoherent vector
+meson production within the QCD color dipole picture, including saturation
+effects. Theoretical estimates for scattering on both light and heavy nuclei
+are given over a wide range of energy.",0905.1143v1
+2009-09-29,Dynamical Phase Trajectories in Baryon and Isospin Density Spaces,"We review recent results obtained for charge asymmetric systems at Fermi and
+intermediate energies, ranging from 30 MeV/u to 1 GeV/u. Observables sensitive
+to the isospin dependent part of nuclear interaction are discussed, providing
+information on the symmetry energy behavior from sub- to supra-saturation
+densities.",0909.5312v1
+2009-10-21,Discovery of photon index saturation in the black hole binary GRS 1915+105,"We present a study of the correlations between spectral, timing properties
+and mass accretion rate observed in X-rays from the Galactic Black Hole (BH)
+binary GRS 1915+105 during the transition between hard and soft states. We
+analyze all transition episodes from this source observed with RXTE,
+coordinated with Ryle Radio Telescope (RT) observations. We show that
+broad-band energy spectra of GRS 1915+105 during all these spectral states can
+be adequately presented by two Bulk Motion Comptonization (BMC) components: a
+hard component (BMC1, photon index Gamma_1=1.7-3.0) with turnover at high
+energies and soft thermal component (BMC2, Gamma_2=2.7-4.2) with characteristic
+color temperature <1 keV, and the redskewed iron line (LAOR) component. We also
+present observable correlations between the index and the normalization of the
+disk ""seed"" component. The use of ""seed"" disk normalization, which is
+presumably proportional to mass accretion rate in the disk, is crucial to
+establish the index saturation effect during the transition to the soft state.
+We discovered the photon index saturation of the soft and hard spectral
+components at values of 4.2 and 3 respectively. We present a physical model
+which explains the index-seed photon normalization correlations. We argue that
+the index saturation effect of the hard component (BMC1) is due to the soft
+photon Comptonization in the converging inflow close to BH and that of soft
+component is due to matter accumulation in the transition layer when mass
+accretion rate increases. In addition to our spectral model components we also
+find a strong feature of ""blackbody-like"" bump which color temperature is about
+4.5 keV in eight observations of the intermediate and soft states. We discuss a
+possible origin of this ""blackbody-like"" emission.",0910.4099v1
+2009-11-07,Low-x QCD at the LHC with the ALICE detector,"We give a brief review of the physics of gluon saturation and non-linear QCD
+evolution at small values of the Bjorken-$x$ variable. We discuss the ALICE
+capability for low-$x$ studies at the LHC. In particular, we concentrate on the
+heavy quark production in the CGC framework and its observation with the ALICE
+Muon Spectrometer.",0911.1458v1
+2009-12-10,Envelope Soliton Oscillator for UWB,"An electronic oscillator is shown to support an envelope soliton pulse. The
+oscillator comprises a loop, formed by a nonlinear transmission line, an
+amplifier, a bandpass filter and a saturable absorber. The soliton is suitable
+for ultra-wideband radio-frequency communication; its existence and stability
+are demonstrated with simulations.",0912.1906v1
+2009-12-30,A class of compact subsets for non-sober topological spaces,"We define a class of subsets of a topological space that coincides with the
+class of compact saturated subsets when the space is sober, and with enough
+good properties when the space is not sober. This class is introduced
+especially in view of applications to capacity theory.",0912.5469v3
+2010-01-12,Threshold Saturation via Spatial Coupling: Why Convolutional LDPC Ensembles Perform so well over the BEC,"Convolutional LDPC ensembles, introduced by Felstrom and Zigangirov, have
+excellent thresholds and these thresholds are rapidly increasing as a function
+of the average degree. Several variations on the basic theme have been proposed
+to date, all of which share the good performance characteristics of
+convolutional LDPC ensembles. We describe the fundamental mechanism which
+explains why ""convolutional-like"" or ""spatially coupled"" codes perform so well.
+In essence, the spatial coupling of the individual code structure has the
+effect of increasing the belief-propagation (BP) threshold of the new ensemble
+to its maximum possible value, namely the maximum-a-posteriori (MAP) threshold
+of the underlying ensemble. For this reason we call this phenomenon ""threshold
+saturation."" This gives an entirely new way of approaching capacity. One
+significant advantage of such a construction is that one can create
+capacity-approaching ensembles with an error correcting radius which is
+increasing in the blocklength. Our proof makes use of the area theorem of the
+BP-EXIT curve and the connection between the MAP and BP threshold recently
+pointed out by Measson, Montanari, Richardson, and Urbanke. Although we prove
+the connection between the MAP and the BP threshold only for a very specific
+ensemble and only for the binary erasure channel, empirically a threshold
+saturation phenomenon occurs for a wide class of ensembles and channels. More
+generally, we conjecture that for a large range of graphical systems a similar
+saturation of the ""dynamical"" threshold occurs once individual components are
+coupled sufficiently strongly. This might give rise to improved algorithms as
+well as to new techniques for analysis.",1001.1826v2
+2010-02-22,Almost sure asymptotics for the random binary search tree,"We consider a (random permutation model) binary search tree with n nodes and
+give asymptotics on the loglog scale for the height H_n and saturation level
+h_n of the tree as n\to\infty, both almost surely and in probability. We then
+consider the number F_n of particles at level H_n at time n, and show that F_n
+is unbounded almost surely.",1002.3896v1
+2010-08-02,TeV Scale Cross-Sections and the Pomeranchuck Singularity,"We have investigated the detailed structure of $l$-plane singularities of
+scattering amplitude saturating the Froissart bound. A self-consistent analysis
+of these singularities provides us secondary terms in the Froissart bound.
+These secondary terms lead to ghosts in the $l$-plane, which can only be
+removed by introducing an odderon singularity. Phenomenological implications of
+this analysis are also discussed.",1008.0218v1
+2010-08-02,Studies of scaling properties in deep inelastic scattering,"We study the scaling properties in deep inelastic scattering using the most
+recent combined structure function data $F_2$ from the H1 and ZEUS
+collaborations. We also perform a direct fit to the $F_2$ data inspired by the
+scaling properties. Our analysis favours the QCD saturation mechanism from the
+Balitski Kovchegiv equation wuth running coupling.",1008.0261v1
+2010-08-31,Unitarity and the color confinement,"We discuss how confinement property of QCD results in the rational
+unitarization scheme and how unitarity saturation leads to appearance of a
+hadron liquid phase at very high temperatures.",1008.5247v1
+2010-09-22,A Simple Proof of Thue's Theorem on Circle Packing,"A simple proof of Thue theorem on Circle Packing is given. The proof is only
+based on density analysis of Delaunay triangulation for the set of points that
+are centers of circles in a saturated circle configuration.",1009.4322v1
+2010-10-31,"Graphene Q-switched, tunable fiber laser","We demonstrate a wideband-tunable Q-switched fiber laser exploiting a
+graphene saturable absorber. We get ~2us pulses, tunable between 1522 and
+1555nm with up to~40nJ energy. This is a simple and low-cost light source for
+metrology, environmental sensing and biomedical diagnostics.",1011.0115v1
+2010-11-11,"UHE neutrinos: higher twists, scales, saturation","It is shown that in the ultra-high energy neutrino interactions the higher
+twist corrections brought about by the non-conservation of the top-bottom
+current dramatically change the longitudinal structure function, $F_L$. To the
+Double Leading Log Approximation simple and numerically accurate formulas for
+$F_L$ and $\sigma^{\nu N}$ are derived.",1011.2611v1
+2010-12-02,A direct proof of the five element basis theorem,"We present a direct proof of the consistency of the existence of a five
+element basis for the uncountable linear orders. Our argument is based on the
+approach of notion of saturation of Aronszajn trees considered by Koenig,
+Larson, Moore and Velickovic and simplifies the original proof of Moore.",1012.0596v2
+2010-12-15,A Duality of Quantale-Enriched Categories,"We describe a duality for quantale-enriched categories that extends the
+Lawson duality for continuous dcpos: for any saturated class J of modules that
+commute with certain weighted limits, and under an appropriate choice of
+morphisms, the category of J-cocomplete and J-continuous quantale-enriched
+categories is self-dual.",1012.3351v1
+2010-12-21,Rapidity and centrality dependence of azimuthal correlations in high energy d+Au collisions,"We discuss azimuthal correlations in $dAu$ collisions at different rapidities
+and centralities and argue that experimentally observed depletion of the
+back-to-back peak can be quantitatively explained by gluon saturation in the
+Color Glass Condensate of the Gold nucleus.",1012.4709v1
+2011-02-20,Conformal symmetry and the Balitsky-Kovchegov equation,"Solutions to the Balitsky-Kovchegov equation are considered which respect an
+SO(3) subgroup of the conformal group. The symmetry dictates a specific
+dependence of the saturation scale on the impact parameter. Applications to
+deep inelastic scattering are considered.",1102.4040v2
+2011-03-07,Does parton saturation at high density explain hadron multiplicities at LHC?,"An addendum to our previous papers in Phys. Lett. B539 (2002) 46 and Phys.
+Lett. B502 (2001) 51, contributed to the CERN meeting ""First data from the LHC
+heavy ion run"", March 4, 2011",1103.1259v1
+2011-03-24,On a question of L.A. Shemetkov concerning the intersection of $\cal F$-maximal subgroups of finite groups,"We investigate the influence of the intersection of the $\cal F$-maximal
+subgroups on the structure of a finite group. In particular, answering a
+question of L.A Shemetkov we give conditions under which a hereditary saturated
+formation $\cal F$ has a property that for any finite group $G$, the ${\cal
+F}$-hypercentre of $G$ coincides with the intersection of all $\cal F$-maximal
+subgroups of $G$.",1103.4729v1
+2011-03-31,Local definitions of formations of finite groups,"A problem of constructing of local definitions for formations of finite
+groups is discussed in the article. The author analyzes relations between local
+definitions of various types. A new proof of existence of an
+$\omega$-composition satellite of an $\omega$-solubly saturated formation is
+obtained. It is proved that if a non-empty formation of finite groups is
+$\mathfrak X$-local by F\""{o}rster, then it has an $\mathfrak X$-composition
+satellite.",1103.6259v1
+2011-04-21,Symmetric chain decomposition of necklace posets,"A finite ranked poset is called a symmetric chain order if it can be written
+as a disjoint union of rank-symmetric, saturated chains. If $P$ is any
+symmetric chain order, we prove that $P^n/\mathbb{Z}_n$ is also a symmetric
+chain order, where $\mathbb{Z}_n$ acts on $P^n$ by cyclic permutation of the
+factors.",1104.4147v3
+2011-04-21,A Resolution of the Paradox of Enrichment,"The paradox of enrichment was observed by M. Rosenzweig in a class of
+predator-prey models. Two of the parameters in the models are crucial for the
+paradox. These two parameters are the prey's carrying capacity and prey's
+half-saturation for predation. Intuitively, increasing the carrying capacity
+due to enrichment of the prey's environment should lead to a more stable
+predator-prey system. Analytically, it turns out that increasing the carrying
+capacity always leads to an unstable predator-prey system that is susceptible
+to extinction from environmental random perturbations. This is the so-called
+paradox of enrichment. Our resolution here rests upon a closer investigation on
+a dimensionless number $H$ formed from the carrying capacity and the prey's
+half-saturation. By recasting the models into dimensionless forms, the models
+are in fact governed by a few dimensionless numbers including $H$. The effects
+of the two parameters: carrying capacity and half-saturation are incorporated
+into the number $H$. In fact, increasing the carrying capacity is equivalent
+(i.e. has the same effect on $H$) to decreasing the half-saturation which
+implies more aggressive predation. Since there is no paradox between more
+aggressive predation and instability of the predator-prey system, the paradox
+of enrichment is resolved.
+  We also further explore spatially dependent models for which the phase space
+is infinite dimensional. The spatially independent limit cycle which is
+generated by a Hopf bifurcation from an unstable steady state, is linearly
+stable in the infinite dimensional phase space. Numerical simulations indicate
+that the basin of attraction of the limit cycle is riddled. This shows that
+spatial perturbations can sometimes (neither always nor never) remove the
+paradox of enrichment near the limit cycle!",1104.4355v2
+2011-04-29,Ytterbium- and chromium-doped fibre laser: from chaotic self-pulsing to passive Q-switching,"A spontaneously chaotic, self-pulsing ytterbium-doped fibre laser is
+partially stabilized into the passively Q-switched mode of operation using a
+chromium-doped saturable absorber fibre. This original all-fibre laser produces
+sustained and stable trains of smooth pulses at high repetition rate.",1104.5657v1
+2011-06-14,Monte Carlo study of carrier-light coupling in terahertz quantum cascade lasers,"We present a method for self-consistently including the optical cavity field
+into Monte Carlo-based carrier transport simulations. This approach allows for
+an analysis of the actual lasing operation in quantum cascade lasers,
+considering effects such as gain saturation and longitudinal mode competition.
+Simulation results for a terahertz quantum cascade laser are found to be
+consistent with experiment.",1106.2739v1
+2011-06-17,"Connected components of definable groups, and o-minimality II","We study the connected components G^00, G^000 and their quotients for a group
+G definable in a saturated o-minimal expansion of a real closed field. We show
+that G^00/G^000 is naturally the quotient of a connected compact commutative
+Lie group by a dense finitely generated subgroup. We also highlight the role of
+universal covers of semisimple Lie groups.",1106.3442v1
+2011-07-06,Forward and Mueller-Navelet Jets,"We discuss the production of forward jets in high energy processes where one
+probes a dense hadronic wavefunction. In particular, and as a signature of
+parton saturation, we discuss the possibility of a strong momentum
+decorrelation in Mueller-Navelet jets which leads to a geometric scaling
+behavior.",1107.1269v1
+2011-07-29,Neutrinoless Double Beta Decay and Heavy Sterile Neutrinos,"The experimental rate of neutrinoless double beta decay can be saturated by
+the exchange of virtual sterile neutrinos, that mix with the ordinary neutrinos
+and are heavier than 200 MeV. Interestingly, this hypothesis is subject only to
+marginal experimental constraints, because of the new nuclear matrix elements.
+This possibility is analyzed in the context of the Type I seesaw model,
+performing also exploratory investigations of the implications for heavy
+neutrino mass spectra, rare decays of mesons as well as neutrino-decay search,
+LHC, and lepton flavor violation. The heavy sterile neutrinos can saturate the
+rate only when their masses are below some 10 TeV, but in this case, the
+suppression of the light-neutrino masses has to be more than the ratio of the
+electroweak scale and the heavy-neutrino scale; i.e., more suppressed than the
+naive seesaw expectation. We classify the cases when this condition holds true
+in the minimal version of the seesaw model, showing its compatibility (1) with
+neutrinoless double beta rate being dominated by heavy neutrinos and (2) with
+any light neutrino mass spectra. The absence of excessive fine-tunings and the
+radiative stability of light neutrino mass matrices, together with a saturating
+sterile neutrino contribution, imply an upper bound on the heavy neutrino
+masses of about 10 GeV. We extend our analysis to the Extended seesaw scenario,
+where the light and the heavy sterile neutrino contributions are completely
+decoupled, allowing the sterile neutrinos to saturate the present experimental
+bound on neutrinoless double beta decay. In the models analyzed, the rate of
+this process is not strictly connected with the values of the light neutrino
+masses, and a fast transition rate is compatible with neutrinos lighter than
+100 meV.",1108.0004v2
+2011-10-10,Chief factors covered by projectors of soluble Leibniz algebras,"Let F be a saturated formation of soluble Leibniz algebras. Let K be an
+F-projector and A/B a chief factor of the soluble Leibniz algebra L. It is
+well-known that if A/B is F-central, then K covers A/B. I prove the converse:
+if K covers A/B, then A/B is F-central.",1110.1932v1
+2011-10-18,A survey of the parameter space of the compressible liquid drop model as applied to the neutron star inner crust,"We present a systematic survey the range of predictions of the neutron star
+inner crust composition, crust-core transition densities and pressures, and
+density range of the nuclear `pasta' phases at the bottom of the crust provided
+by the compressible liquid drop model in the light of current experimental and
+theoretical constraints on model parameters. Using a Skyrme-like model for
+nuclear matter, we construct baseline sequences of crust models by consistently
+varying the density dependence of the bulk symmetry energy at nuclear
+saturation density, $L$, under two conditions: (i) that the magnitude of the
+symmetry energy at saturation density $J$ is held constant, and (ii) $J$
+correlates with $L$ under the constraint that the pure neutron matter (PNM) EoS
+satisfies the results of ab-initio calculations at low densities. Such baseline
+crust models facilitate consistent exploration of the $L$ dependence of crustal
+properties. The remaining surface energy and symmetric nuclear matter
+parameters are systematically varied around the baseline, and different
+functional forms of the PNM EoS at sub-saturation densities implemented, to
+estimate theoretical `error bars' for the baseline predictions. Inner crust
+composition and transition densities are shown to be most sensitive to the
+surface energy at very low proton fractions and to the behavior of the
+sub-saturation PNM EoS. Recent calculations of the energies of neutron drops
+suggest that the low-proton-fraction surface energy might be higher than
+predicted in Skyrme-like models, which our study suggests may result in a
+greatly reduced volume of pasta in the crust than conventionally predicted.",1110.4043v2
+2011-11-29,"Numerical simulation of turbulent sediment transport, from bed load to saltation","Sediment transport is studied as a function of the grain to fluid density
+ratio using two phase numerical sim- ulations based on a discrete element
+method (DEM) for particles coupled to a continuum Reynolds averaged description
+of hydrodynamics. At a density ratio close to unity (typically under water),
+vertical velocities are so small that sediment transport occurs in a thin layer
+at the surface of the static bed, and is called bed load. Steady, or
+'saturated' transport is reached when the fluid borne shear stress at the
+interface between the mobile grains and the static grains is reduced to its
+threshold value. The number of grains transported per unit surface is therefore
+limited by the flux of horizontal momentum towards the surface. However, the
+fluid velocity in the transport layer remains almost undisturbed so that the
+mean grain velocity scales with the shear velocity u\ast. At large density
+ratio (typically in air), the vertical velocities are large enough to make the
+transport layer wide and dilute. Sediment transport is then called saltation.
+In this case, particles are able to eject others when they collide with the
+granular bed, a process called splash. The number of grains transported per
+unit surface is selected by the balance between erosion and deposition and
+saturation is reached when one grain is statistically replaced by exactly one
+grain after a collision, which has the consequence that the mean grain velocity
+remains independent of u\ast. The influence of the density ratio is
+systematically studied to reveal the transition between these two transport
+regimes. Based on the mechanisms identified in the steady case, we discuss the
+transient of saturation of sediment transport and in particular the saturation
+time and length. Finally, we investigate the exchange of particles between the
+mobile and static phases and we determine the exchange time of particles.",1111.6898v2
+2011-12-13,Strongly inessential elements of a perfect height 2 ideal,"In this paper we expand on some results exposed in a previous one, in which
+we introduced the concept of inessential and strongly inessential generators in
+a standard basis of a saturated homogeneous ideal. The appearance of strongly
+inessential elements seemed to be a non generic situation; in this paper we
+analyze their presence in a perfect height 2 ideal with the greatest number of
+generators, according to Dubreil's inequality.",1112.2875v1
+2011-12-19,Forward physics hard processes and saturation: theory and phenomenology review,"Selected aspects of the theory and phenomenology of production of forward
+jets at the LHC and RHIC are overviewed. In the theory part we discuss basics
+of frameworks originating from the BFKL dynamics while in the phenomenology
+part we present results for forward-central jet correlations at the LHC and
+forward di-jet production at RHIC.",1112.4361v1
+2012-01-16,"Comment on ""Rotary Photon Drag Enhanced by a Slow-Light Medium [1]""","The observations reported by Franke-Arnold et al (SCIENCE Reports, 1 July
+2011 p. 65) do not provide evidence of slow light enhanced rotary photon drag
+as claimed, but arise from well-known saturable absorption phenomena consistent
+with the use of a spectrally broad light source, as described in their
+theoretical analysis (supporting online material)",1201.3226v1
+2012-02-11,On Patchworks and Hierarchies,"Motivated by questions in biological classification, we discuss some
+elementary combinatorial and computational properties of certain set systems
+that generalize hierarchies, namely, 'patchworks', 'weak patchworks', 'ample
+patchworks' and 'saturated patchworks' and also outline how these concepts
+relate to an apparently new 'duality theory' for cluster systems that is based
+on the fundamental concept of 'compatibility' of clusters.",1202.2460v1
+2012-04-26,Sub-Wavelength Nonlinear Accelerating Beams,"We show that optical nonlinearities allow sub-wavelength beams to propagate
+in circular trajectories without being attenuated in spite of their partially
+evanescent spectrum. Such beams are exact solutions to Maxwell's equations with
+Kerr or saturable nonlinearity.",1204.5866v1
+2012-05-02,A remark on the definability of the Fitting subgroup and the soluble radical,"Let $G$ be an arbitrary group. We show that if the Fitting subgroup of $G$ is
+nilpotent then it is definable. We show also that the class of groups whose
+Fitting subgroup is nilpotent of class at most $n$ is elementary. We give an
+example of a group (arbitrary saturated) whose Fitting subgroup is definable
+but not nilpotent. Similar results for the soluble radical are given.",1205.0573v1
+2012-05-21,Tricritical quantum point and inflationary cosmology,"The holographic protection due to inflationary cosmology is a conse- quence
+of a quantum tricritical point. In this scenario a closed spacetime solution
+transitions into an inflationary de Sitter spacetime. Saturation of the
+holographic entropy bound is prevented by the phase change in the topology of
+the early universe.",1205.4710v1
+2012-06-06,Nonlinear extension of the CCFM equation,"In order to study such effects like parton saturation in final states at the
+LHC one of the approaches is to combine physics of the BK and the CCFM
+evolution equations. We report on recently obtained resummed form of the BK
+equation and nonlinear extension of the CCFM equation.",1206.1223v1
+2012-06-13,Fusion systems on bicyclic 2-groups,"We classify all (saturated) fusion systems on bicyclic 2-groups. Here, a
+bicyclic group is a product of two cyclic subgroups. This extends previous work
+on fusion systems on metacyclic 2-groups (see [Craven-Glesser, 2012] and
+[Sambale, 2012]). As an application we prove Olsson's Conjecture for all blocks
+with bicyclic defect groups.",1206.2962v3
+2012-09-14,The Color Glass Condensate and some applications,"We give an elementary discussion of parton saturation and its description by
+the effective theory of the Color Glass Condensate. We report on progress in
+calculating multi-gluon correlators. The latter are necessary for many
+phenomenological applications, upon some of which we briefly touch.",1209.3183v1
+2012-09-14,Passively Q-switched Ytterbium and Chromium all-fibre laser,"A chromium-doped saturable absorber fibre stabilizes an otherwise
+spontaneously chaotic ytterbium- doped fibre laser. This original passively
+Q-switched all-fibre laser produces sustained and stable trains of smooth
+pulses at high repetition rate.",1209.3222v1
+2012-10-11,The bar instability revisited,"The river bar instability is revisited, using a hydrodynamical model based on
+Reynolds averaged Navier-Stokes equations. The results are contrasted with the
+standard analysis based on shallow water Saint-Venant equations. We first show
+that the stability of both transverse modes (ripples) and of small wavelength
+inclined modes (bars) predicted by the Saint-Venant approach are artefacts of
+this hydrodynamical approximation. When using a more reliable hydrodynamical
+model, the dispersion relation does not present any maximum of the growth rate
+when the sediment transport is assumed to be locally saturated. The analysis
+therefore reveals the fundamental importance of the relaxation of sediment
+transport towards equilibrium as it it is responsible for the stabilisation of
+small wavelength modes. This dynamical mechanism is characterised by the
+saturation number, defined as the ratio of the saturation length to the water
+depth Lsat/H. This dimensionless number controls the transition from ripples
+(transverse patterns) at small Lsat/H to bars (inclined patterns) at large
+Lsat/H. At a given value of the saturation number, the instability presents a
+threshold and a convective-absolute transition, both controlled by the channel
+aspect ratio {\beta}. We have investigated the characteristics of the most
+unstable mode as a function of the main parameters, Lsat/H, {\beta} and of a
+subdominant parameter controlling the relative influence of drag and gravity on
+sediment transport. As previously found, the transition from alternate bars to
+multiple bars is mostly controlled by the river aspect ratio {\beta}. By
+contrast, in the alternate bar regime (large Lsat/H), the selected wavelength
+does not depend much on {\beta} and approximately scales as H^(2/3)L^(1/3)/C,
+where C is the Ch\'ezy number.",1210.3223v1
+2012-11-16,Some aspects of final states and QCD evolution equations,"In order to study such effects like parton saturation in final states at the
+LHC one of the approaches is to combine physics of the BK and the CCFM
+evolution equations. We report on recently obtained resummed form of the BK
+equation and nonlinear extension of the CCFM equation - the KGBJS equation.",1211.3777v1
+2012-11-28,Trees of Fusion Systems,"We define a `tree of fusion systems' and give a sufficient condition for its
+completion to be saturated. We apply this result to enlarge an arbitrary fusion
+system by extending the automorphism groups of certain of its subgroups.",1211.6700v3
+2013-01-28,On some automatic continuity theorems,"We give characterizations of unital uniform topological algebras and
+saturated locally multiplicatively convex algebras by means of multiplicative
+linear functionals. Some automatic continuity theorems in advertibly complete
+uniform topological algebras are extended to a larger class of algebras.
+Consequences and applications are given.",1301.6549v1
+2013-02-08,Short probabilistic proof of the Brascamp-Lieb and Barthe theorems,"We give a short proof of the Brascamp-Lieb theorem, which asserts that a
+certain general form of Young's convolution inequality is saturated by Gaussian
+functions. The argument is inspired by Borell's stochastic proof of the
+Pr\'ekopa-Leindler inequality and applies also to the reversed Brascamp-Lieb
+inequality, due to Barthe.",1302.2066v1
+2013-03-21,Droplet condensation and isoperimetric towers,"We consider a variational problem in a planar convex domain, motivated by
+statistical mechanics of crystal growth in a saturated solution. The minimizers
+are constructed explicitly and are completely characterized.",1303.5202v1
+2013-04-02,"The BPS spectrum of the 4d N=2 SCFT's H_1, H_2, D_4, E_6, E_7, E_8","Extending results of arXiv:1112.3984, we show that all rank 1 N=2 SCFT's in
+the sequence H_1, H_2, D_4 E_6, E_7, E_8 have canonical finite BPS chambers
+containing precisely 2 h(F)=12(Delta-1) hypermultiplets. The BPS spectrum of
+the canonical BPS chambers saturates the conformal central charge c, and
+satisfies some intriguing numerology.",1304.0614v1
+2013-05-13,An interatomic potential for saturated hydrocarbons based on the modified embedded-atom method,"In this work, we developed an interatomic potential for saturated
+hydrocarbons using the modified embedded-atom method (MEAM), a reactive
+semi-empirical many-body potential based on density functional theory and pair
+potentials. We parameterized the potential by fitting to a large experimental
+and first-principles (FP) database consisting of 1) bond distances, bond
+angles, and atomization energies at 0 K of a homologous series of alkanes and
+their select isomers from methane to n-octane, 2) the potential energy curves
+of H$_2$, CH, and C$_2$ diatomics, 3) the potential energy curves of hydrogen,
+methane, ethane, and propane dimers, i.e., (H$_2$)$_2$, (CH$_4$)$_2$,
+(C$_2$H$_6$)$_2$, and (C$_3$H$_8$)$_2$, respectively, and 5)
+pressure-volume-temperature (PVT) data of a dense high-pressure methane system
+with the density of 0.5534 g/cc. We compared the atomization energies and
+geometries of a range of linear alkanes, cycloalkanes, and free radicals
+calculated from the MEAM potential to those calculated by other commonly used
+reactive potentials for hydrocarbons, i.e., second-generation reactive
+empirical bond order (REBO) and reactive force field (ReaxFF). MEAM reproduced
+the experimental and/or FP data with accuracy comparable to or better than REBO
+or ReaxFF. The experimental PVT data for a relatively large series of methane,
+ethane, propane, and butane systems with different densities were predicted
+reasonably well by MEAM. Although the MEAM formalism has been applied to atomic
+systems with predominantly metallic bonding in the past, the current work
+demonstrates the promising extension of the MEAM potential to covalently bonded
+molecular systems, specifically saturated hydrocarbons and saturated
+hydrocarbon-based polymers.",1305.2759v7
+2013-06-15,Thresholds of Spatially Coupled Systems via Lyapunov's Method,"The threshold, or saturation phenomenon of spatially coupled systems is
+revisited in the light of Lyapunov's theory of dynamical systems. It is shown
+that an application of Lyapunov's direct method can be used to quantitatively
+describe the threshold phenomenon, prove convergence, and compute threshold
+values. This provides a general proof methodology for the various systems
+recently studied. Examples of spatially coupled systems are given and their
+thresholds are computed.",1306.3610v1
+2013-06-19,Nonlinear Control of Absorption in Graphene-based 1D Photonic Crystal,"Perfect, narrow-band absorption is achieved in an asymmetric 1D photonic
+crystal with a monolayer graphene defect. Thanks to the large third order
+nonlinearity of graphene and field localization in the defect layer we
+demonstrate the possibility to achieve controllable, saturable absorption for
+the pump frequency.",1306.4607v1
+2013-07-25,Neutron Star Matter,"In this presentation I discuss two aspects of the neutron-matter equation of
+state. One relates to the symmetry energy of nuclear matter and empirical
+constraints on its slope parameter at saturation density. The second deals with
+spatially inhomogeneous chiral phases of deconfined quark matter in the inner
+core of a neutron star.",1307.6714v1
+2013-10-31,Absolute Algebra III - The saturated spectrum,"Let B1 denote the set {0,1} with the usual operations except that $1+1=1$, in
+other words, the smallest characteristic 1 semifield . We compare two possible
+analogues of the notion of prime ideal for B1--algebras. We then consider the
+relations between these notions and Deitmar's theory of F1--schemes.",1310.8399v1
+2013-11-15,A theorem of Mislin for cohomology of fusion systems and applications to block algebras of finite groups,"We give an algebraic proof for a theorem of Mislin in the case of cohomology
+of saturated fusion systems defined on p-groups when p is odd. Some
+applications of this theorem to block algebras of finite groups are also given.",1311.3944v2
+2013-11-28,Potential of a longitudinally focusing insertion for a storage ring X-ray FEL,"In present work we investigate the potential of a longitudinally focusing
+device to compress bunches passing an undulator for a synchrotron storage ring.
+If integrated into a storage ring similar to PETRAIII such device could
+potentially produce continuous $\sim$1ps pulses of photons in the $nm$ range
+with peak pulse powers of tens of GW. Even without operating in FEL saturation
+mode the longitudinal focusing can provide means to increase the brightness and
+shorten the photon pulse length.",1311.7428v1
+2013-12-20,"Thermalization, Isotropization and Elliptic Flow from Nonequilibrium Initial Conditions with a Saturation Scale","In this article we report on our results about the computation of the
+elliptic flow of the quark-gluon-plasma produced in relativistic heavy ion
+collisions, simulating the expansion of the fireball by solving the
+relativistic Boltzmann equation for the parton distribution function tuned at a
+fixed shear viscosity to entropy density ratio $\eta/s$. Our main goal is to
+put emphasis on the role of a saturation scale in the initial gluon spectrum,
+which makes the initial distribution far from a thermalized one. We find that
+the presence of the saturation scale reduces the efficiency in building-up the
+elliptic flow, even if the thermalization process is quite fast $\tau_{therm}
+\approx 0.8 \,\rm fm/c$ and the pressure isotropization even faster
+$\tau_{isotr} \approx 0.3 \,\rm fm/c$. The impact of the non-equilibrium
+implied by the saturation scale manifests for non-central collisions and can
+modify the estimate of the viscosity respect to the assumption of full
+thermalization in $p_T$-space. We find that the estimate of $\eta/s$ is
+modified from $\eta/s \approx 2/4\pi$ to $\eta/s \approx 1/4\pi$ at RHIC and
+from $\eta/s \approx 3/4\pi$ to $\eta/s \approx 2/4\pi$ at LHC. We complete our
+investigation by a study of the thermalization and isotropization times of the
+fireball for different initial conditions and values of $\eta/s$ showing how
+the latter affects both isotropization and thermalization. Lastly, we have seen
+that the range of values explored by the phase-space distribution function $f$
+is such that at $p_T<0.5\, \rm GeV$ the inner part of the fireball stays with
+occupation number significantly larger than unity despite the fast longitudinal
+expansion, which might suggest the possibility of the formation of a transient
+Bose-Einstein Condensate.",1312.6060v2
+2014-01-10,On a general definition of the squared Brunt-Väisälä Frequency associated with the specific moist entropy potential temperature,"The squared Brunt-V\""{a}is\""{a}l\""{a} Frequency (BVF) is computed in terms of
+the moist entropy potential temperature recently defined in Marquet (2011).
+Both homogeneously saturated and non-saturated versions of $N^2$ (the squared
+BVF) are derived. The method employed for computing these special homogeneous
+cases relies on the expression of density written as a function of pressure,
+total water content and specific moist entropy only. The associated
+conservative variable diagrams are discussed and compared with existing ones.
+Despite being obtained without any simplification, the formulations for $N^2$
+remain nicely compact and are clearly linked with the squared BVF expressed in
+terms of the adiabatic non-saturated and saturated lapse rates. As in previous
+similar expressions, the extreme homogeneous solutions for $N^2$ are of course
+different, but they are not analytically discontinuous. This allows us to
+define a simple bridging expression for a single general shape of $N^2$,
+depending only on the basic mean atmospheric quantities and on a transition
+parameter, to be defined (or parameterized) in connection with the type of
+application sought. This integrated result remains a linear combination (with
+complex but purely local weights) of two terms only, namely the environmental
+gradient of the moist entropy potential temperature and the environmental
+gradient of the total water content. Simplified versions of the various
+equations are also proposed for the case in which the moist entropy potential
+temperature is approximated by a function of both so-called moist-conservative
+variables of Betts (1973).",1401.2379v2
+2014-01-19,Almost Prime Coordinates for Anisotropic and Thin Pythagorean Orbits,"We make an observation which doubles the exponent of distribution in certain
+Affine Sieve problems, such as those considered by Liu-Sarnak, Kontorovich, and
+Kontorovich-Oh. As a consequence, we decrease the known bounds on the
+saturation numbers in these problems.",1401.4701v1
+2014-01-30,Fitting N$^{3}$LO pseudopotentials through central plus tensor Landau parameters,"Landau parameters determined from phenomenological finite-range interactions
+are used to get an estimation of N$^3$LO pseudopotentials parameters. The
+parameter sets obtained in this way are shown to lead to consistent results
+concerning saturation properties. The uniqueness of this procedure is
+discussed, and an estimate of the error induced by the truncation at N$^3$LO is
+given.",1401.7914v1
+2014-03-13,A Sensitive Identification of Warm Debris Disks in the Solar Neighborhood Through Precise Calibration of Saturated WISE Photometry,"We present a sensitive search for WISE W3 (12um) and W4 (22um) excesses from
+warm optically thin dust around Hipparcos main sequence stars within 75pc from
+the Sun. We use contemporaneously measured photometry from WISE, remove sources
+of contamination, and derive and apply corrections to saturated fluxes to
+attain optimal sensitivity to >10um excesses. We use data from the WISE All-Sky
+Survey Catalog rather than the AllWISE release, because we find that its
+saturated photometry is better behaved, allowing us to detect small excesses
+even around saturated stars in WISE. Our new discoveries increase by 45% the
+number of stars with warm dusty excesses and expand the number of known debris
+disks (with excess at any wavelength) within 75pc by 29%. We identify 220
+Hipparcos debris disk-host stars, 108 of which are new detections at any
+wavelength. We present the first measurement of a 12um and/or 22um excess for
+10 stars with previously known cold (50-100 K) disks. We also find five new
+stars with small but significant W3 excesses, adding to the small population of
+known exozodi, and we detect evidence for a W2 excess around HIP96562 (F2V),
+indicative of tenuous hot (780 K) dust. As a result of our WISE study, the
+number of debris disks with known 10-30um excesses within 75pc (379) has now
+surpassed the number of disks with known >30um excesses (289, with 171 in
+common), even if the latter have been found to have a higher occurrence rate in
+unbiased samples.",1403.3435v1
+2014-03-18,Landscape disruption effects in a meta-epidemic model with steady state demographics and migrations saturation,"We continue the investigations of an ecosystem where a epidemic-affected
+population can move between two connected patches, by considering what happens
+to the system when the migration paths are interrupted in one direction, or
+when the infected are not able to exert the effort for migrating into the other
+patch.",1403.4470v1
+2014-04-24,The number of orthogonal conjugations,"After a short introduction to anti-linearity, bounds for the number of
+orthogonal (skew) conjugations are proved. They are saturated if the dimension
+of the Hilbert space is a power of two. For the other dimensions this is an
+open problem.",1404.6052v1
+2014-05-12,Geometrical scaling and its breaking in high energy collisions,"We report on recent analyses of different pieces of data, which exhibit
+Geometrical Scaling (GS) and its breaking. GS is a consequence of the existence
+of an intermediate energy scale, called saturation momentum, and allows to
+relate data at different energies, of different systems and also at different
+multiplicities and/or centralities.",1405.2671v1
+2014-05-19,Black hole mass determination in the X-ray binary 4U 1630--47: Scaling of spectral and variability characteristics,"We present the results of a comprehensive investigation on the evolution of
+spectral and timing properties of the Galactic black hole candidate 4U 1630--47
+during its spectral transitions. In particular, we show how a scaling of the
+correlation of the photon index of the Comptonized spectral component Gamma
+with low frequency of quasi-periodic oscillations (QPO), nu_L and mass
+accretion rate, $\dot M$ can be applied to the black hole mass and the
+inclination angle estimates. We analyze the transition episodes observed with
+the {\it Rossi} X-ray Timing Explorer (RXTE) and BeppoSAX satellites. We find
+that the broadband X-ray energy spectra of 4U~1630--47 during all spectral
+states can be modeled by a combination of a thermal component, a Comptonized
+component and a red-skewed iron line component. We also establish that Gamma
+monotonically increases during transition from the low-hard state to the
+high-soft state and then saturates for high mass accretion rates. The index
+saturation levels vary for different transition episodes. Correlations of Gamma
+versus nu_L also shows saturation at Gamma ~ 3. Gamma-Mdot and Gamma-nu_L
+correlations with their index saturation revealed in 4U~1630--47 are similar to
+those established in a number of other BHCs and can be considered as an
+observational evidence for the presence of a black hole in these sources. The
+scaling technique, which relies on XTE J1550--564, GRO 1655-40 and H 1743-322
+as reference sources, allows us to evaluate a black hole mass in 4U~1630--47
+yielding M_{BH}~10+/- 0.1 solar masses, and to constrain the inclination angle
+of i< 70 degrees.",1405.4711v1
+2014-06-02,Nuclear matter with JISP16 NN interaction,"Saturation properties of the JISP16 NN interaction are studied in symmetric
+nuclear matter calculations, with special attention paid to the convergence
+properties with respect to the number of partial waves. We also present results
+of pure neutron matter calculations with the JISP16 interaction.",1406.0529v1
+2014-06-23,Non-linear evolution equation for gluon density at large values of coupling constant,"The recently proposed nonlinear evolution equation \cite{Kutak:2013hda} for
+unintegrated gluon densities valid for large values of the QCD coupling
+constant $\bar{\alpha} _s$ is presented. In particular we outline its
+derivation, numerical solution and obtained saturation scale.",1406.5897v1
+2014-06-26,Strongly stable ideals and Hilbert polynomials,"The \texttt{StronglyStableIdeals} package for \textit{Macaulay2} provides a
+method to compute all saturated strongly stable ideals in a given polynomial
+ring with a fixed Hilbert polynomial. A description of the main method and
+auxiliary tools is given.",1406.6924v2
+2014-07-11,"Healing of polymer interfaces: Interfacial dynamics, entanglements, and strength","Self-healing of polymer films often takes place as the molecules diffuse
+across a damaged region, above their melting temperature. Using molecular
+dynamics simulations we probe the healing of polymer films and compare the
+results with those for thermal welding of homopolymer slabs. The two processes
+differ in their interfacial structure since damage leads to increased
+polydispersity and more short chains. A polymer sample was cut into two
+separate films that were then held together in the melt state. The recovery of
+the damaged film was followed as time elapsed and polymer molecules diffused
+across the interface. The mass uptake and formation of entanglements, as
+obtained from primitive path analysis, are extracted and correlated with the
+interfacial strength obtained from shear simulations. We find that the
+interdiffusion is significantly faster in the damaged film compared to welding
+because of the presence of short chains. Though interfacial entanglements
+increase more rapidly for the damaged films, a large fraction of them are near
+chain ends. As a result, the interfacial strength of the healing film increases
+more slowly than for welding. For both healing and welding, the interfacial
+strength saturates as the bulk entanglement density is recovered across the
+interface. However, the saturation strength of the damaged film is below the
+bulk strength for the polymer sample. At saturation, cut chains remain near the
+healing interface. They are less entangled and thus mechanically weaken the
+interface. When the interfacial strength saturates, the number of interfacial
+entanglements scales with the corresponding bulk entanglement density. Chain
+stiffness increases the density of entanglements, which increases the
+interfacial strength. Our results show that a few entanglements across the
+interface are sufficient to resist interfacial chain pullout and enhance the
+mechanical strength.",1407.3198v1
+2014-07-21,Conditions for a Schunck class to be a formation,"A Schunck class H is determined by the class X of primitives contained in H.
+We give necessary and sufficient conditions on X for H to be a saturated
+formation.",1407.5692v2
+2014-08-02,On the saturation number for cubic surfaces,"We investigate the density of rational points on the Fermat cubic surface and
+the Cayley cubic surface whose coordinates have few prime factors. The key
+tools used are the weighted sieve, the circle method and universal torsors.",1408.0402v2
+2014-08-15,A presentation theorem for continuous logic and Metric Abstract Elementary Classes,"We give a presentation theorem for continuous first-order logic and Metric
+Abstract Elementary classes in terms of $L_{\omega_1, \omega}$ and Abstract
+Elementary Classes, respectively. This presentation is accomplished by
+analyzing dense subsets that are closed under functions. We extend this
+correspondence to types and saturation.",1408.3624v3
+2014-10-03,Filtrations of Totally Reflexive Modules,"In this paper, we will introduce a subcategory of totally reflexive modules
+that have a saturated filtration by other totally reflexive modules. We will
+prove these are precisely the totally reflexive modules with an
+upper-triangular presentation matrix. We conclude with an investigation of the
+ranks of $\operatorname{Ext}^1$ of two such modules over a specific ring.",1410.0732v1
+2014-10-08,Moduli of parabolic sheaves on a polarized logarithmic scheme,"We generalize the construction of moduli spaces of parabolic sheaves given by
+Maruyama and Yokogawa in [MY92] to the case of a projective fine saturated log
+scheme with a fixed global chart. Furthermore we construct moduli spaces of
+parabolic sheaves without fixing the weights.",1410.2212v2
+2014-10-09,The generic pair conjecture for dependent finite diagrams,"This paper generalizes Shelah's generic pair conjecture (now theorem) for the
+measurable cardinal case from first order theories to finite diagrams. We use
+homogeneous models in the place of saturated models.",1410.2516v4
+2014-11-18,Strong monogamy of quantum entanglement for multi-qubit W-class states,"We provide a strong evidence for strong monogamy inequality of multi-qubit
+entanglement recently proposed in [B. Regula {\em et al.}, Phys. Rev. Lett.
+{\bf 113}, 110501 (2014)]. We consider a large class of multi-qubit generalized
+W-class states, and analytically show that the strong monogamy inequality of
+multi-qubit entanglement is saturated by this class of states.",1411.4721v1
+2014-12-01,The subgroup homology decomposition for fusion systems is sharp,"We extend Dwyer's sharp subgroup homology decomposition of the classifying
+space of a finite group to arbitrary saturated fusion systems and arbitrary
+Mackey functors.",1412.0378v2
+2014-12-24,Why are there three generations of fermions in the standard model?,"We show that by decomposing the gauge fields in fermion degrees of freedom
+and by saturating the remaining degrees of freedom as dynamical fields in the
+Lagrangian one might explain the proliferation of fermion states in the
+standard model Lagrangian. Thus the mere presence of the gauge symmetry $U(1)_Y
+\times SU(2)_L \times SU(3)_c$ is essential.",1412.7658v1
+2015-01-09,"Monitoring of saline tracer movement with vertically distributed self-potential measurements at the HOBE agricultural test site, Voulund, Denmark","The self-potential (SP) method is sensitive to water fluxes in saturated and
+partially saturated porous media, such as those associated with rainwater
+infiltration and groundwater recharge. We present a field-based study at the
+Voulund agricultural test site, Denmark, that is, to the best of our knowledge,
+the first to focus on the vertical self-potential distribution prior to and
+during a saline tracer test. A coupled hydrogeophysical modeling framework is
+used to simulate the SP response to precipitation and saline tracer
+infiltration. A layered hydrological model is first obtained by inverting
+dielectric and matric potential data. The resulting model that compares
+favorably with electrical resistance tomography models is subsequently used to
+predict the SP response. The electrokinetic contribution (caused by water
+fluxes in a charged porous soil) is modeled by an effective excess charge
+approach that considers both water saturation and pore water salinity. Our
+results suggest that the effective excess charge evolution prior to the tracer
+injection is better described by a recent flux-averaged model based on soil
+water retention functions than by a previously proposed volume-averaging model.
+This is the first time that raw vertically distributed SP measurements have
+been explained by a physically based model. The electrokinetic contribution
+cannot alone reproduce the SP data during the tracer test and an
+electro-diffusive contribution (caused by concentration gradients) is needed.
+The predicted amplitude of this contribution is too small to perfectly explain
+the data, but the shape is in accordance with the field data. This discrepancy
+is attributed to imperfect descriptions of electro-diffusive phenomena in
+partially saturated soils, unaccounted soil heterogeneity, and discrepancies
+between the measured and predicted electrical conductivities in the tracer
+infiltration area.",1501.02277v1
+2015-03-08,Structure Constants for Immaculate Functions,"The immaculate functions, $\mathfrak{S}_{\alpha}$, were introduced as a
+Schur-like basis for $\operatorname{\mathsf{Nsym}}$. We investigate facts about
+their structure constants. These are analogues of Littlewood-Richardson
+coefficents. We will give a new proof of the left Pieri rule for the
+$\mathfrak{S}_{\alpha}$, a translation invariance property for the structure
+coefficients of the $\mathfrak{S}_{\alpha}$, and a counterexample to an
+$\mathfrak{S}_{\alpha}$-analogue of the saturation conjecture.",1503.02285v2
+2015-04-01,On Stability of the Linearized Spacecraft Attitude Control System,"This note is concerned with the stability and stabilization of the linearized
+spacecraft attitude control system. Necessary and sufficient conditions are
+respectively provided to guarantee that the considered systems are polynomially
+stable and stable in the Lyapunov sense. These two classes of conditions
+guarantee that the linearized spacecraft attitude control system can be
+respectively stabilized semi-globally and globally by saturated linear state
+feedback.",1504.00114v1
+2015-05-12,Microfiber-based few-layer black phosphorus saturable absorber for ultra-fast fiber laser,"Few-layer black phosphorus (BP), as the most alluring graphene analogue owing
+to its similar structure as graphene and thickness dependent direct band-gap,
+has now triggered a new wave of research on two-dimensional (2D) materials
+based photonics and optoelectronics. However, a major obstacle of practical
+applications for few-layer BPs comes from their instabilities of laser-induced
+optical damage. Herein, we demonstrate that, few-layer BPs, fabricated through
+the liquid exfoliation approach, can be developed as a new and practical
+saturable absorber (SA) by depositing few-layer BPs with microfiber. The
+saturable absorption property of few-layer BPs had been verified through an
+open-aperture z-scan measurement at the telecommunication band and the
+microfiber-based BP device had been found to show a saturable average power of
+~4.5 mW and a modulation depth of 10.9%, which is further confirmed through a
+balanced twin detection measurement. By further integrating this optical SA
+device into an erbium-doped fiber laser, it was found that it can deliver the
+mode-locked pulse with duration down to 940 fs with central wavelength tunable
+from 1532 nm to 1570 nm. The prevention of BP from oxidation through the
+'lateral interaction scheme' owing to this microfiber-based few-layer BP SA
+device might partially mitigate the optical damage problem of BP. Our results
+not only demonstrate that black phosphorus might be another promising SA
+material for ultrafast photonics, but also provide a practical solution to
+solve the optical damage problem of black phosphorus by assembling with
+waveguide structures such as microfiber.",1505.03035v2
+2015-09-22,Surface ages of mid-size Saturnian satellites,"The observations of the surfaces of the mid sized Saturnian satellites made
+by Cassini Huygens mission have shown a variety of features that allows study
+of the processes that took place and are taking place on those worlds. Research
+of the Saturnian satellite surfaces has clear implications for Saturn history
+and surroundings. In a recent paper, the production of craters on the mid sized
+Saturnian satellites by Centaur objects was calculated considering the current
+Solar System. We have compared our results with crater counts from Cassini
+images and we have noted that the number of observed small craters is less than
+our calculated number. In this paper we estimate the age of the surface for
+each observed terrain on each mid sized satellite of Saturn. We have noticed
+that since there are less observed small craters than calculated (except on
+Iapetus), this results in younger ages. This could be the result of efficient
+endogenous or exogenous process(es) for erasing small craters and or crater
+saturation at those sizes. The size limit from which the observed number of
+smaller craters is less than the calculated is different for each satellite,
+possibly indicating processes that are unique to each, but other potential
+common explanations would be crater saturation and or deposition of E ring
+particles. These processes are also suggested by the findings that the smaller
+craters are being preferentially removed, and the erasure process is gradual.
+On Enceladus, only mid and high latitude plains have remnants of old terrains;
+the other regions could be young; the regions near the South Polar Terrain
+could be as young as 50 Myr old. On the contrary for Iapetus, all the surface
+is old and it notably registers a primordial source of craters. As the crater
+size is decreased, it would be perceived to approach saturation until D less
+than 2 km craters, where saturation is complete.",1509.06773v1
+2015-10-02,Analog Optical Computing Primitives in Silicon Photonics,"Optical computing accelerators may help alleviate bandwidth and power
+consumption bottlenecks in electronics. We show an approach to implementing
+logarithmic-type analog co-processors in silicon photonics and use it to
+perform the exponentiation operation. The function is realized by exploiting
+nonlinear-absorption-enhanced Raman amplification saturation in a silicon
+waveguide.",1510.00489v1
+2015-10-09,Arithmetic graphs of finite groups,"In this paper we introduced an arithmetic graph function which associates
+with every group G the directed graph whose vertices corresponds to the
+divisors of |G|. With the help of such functions we introduced arithmetic
+graphs of classes of groups, in particular of hereditary saturated formations.
+We formulated the problem of the recognition of classes of groups by arithmetic
+graph functions and investigated this problem for some arithmetic graph
+functions.",1510.02568v1
+2015-10-21,On cuts in ultraproducts of linear orders I,"For an ultrafilter $D$ on a cardinal $\kappa,$ we wonder for which pair
+$(\theta_1, \theta_2)$ of regular cardinals, we have: for any
+$(\theta_1+\theta_2)^+-$saturated dense linear order $J, J^{\kappa}/ D$ has a
+cut of cofinality $(\theta_1, \theta_2).$ We deal mainly with the case
+$\theta_1, \theta_2 > 2^\kappa.$",1510.06278v3
+2015-10-26,Problems related to the concentration of eigenfunctions,"We survey recent results related to the concentration of eigenfunctions. We
+also prove some new results concerning ball-concentration, as well as showing
+that eigenfunctions saturating lower bounds for $L^1$-norms must also, in a
+measure theoretical sense, have extreme concentration near a geodesic.",1510.07723v1
+2015-11-07,Propagation of Acoustical Wave in Finite Cylindrical Solid Bar surrounded by Semi-Infinite Porous Media saturated with Fluid,"We established the propagation equation of acoustical wave in media with the
+solid/porous media cylindrical boundary and obtained the analytic solution. We
+suggested the boundary condition on solid-porous media cylindrical boundary.
+Based on that, we introduced the dispersion equation, and constructed the
+algorithm to perform numerical calculation and analysis of dispersion equation.",1511.03134v1
+2016-04-21,On the Ramsey Numbers of Trees with Small Diameter,"We estimate the Ramsey number r(T) = r(T,T) for various trees T, obtaining a
+precise value for r(T) for a large number of trees of diameter 3. Furthermore
+we prove that all trees of diameter 3 are Ramsey unsaturated as defined by
+Balister, Lehel, and Schelp in their article ""Ramsey unsaturated and saturated
+graphs.""",1604.06513v1
+2016-07-04,Branching Random Walks on Binary Strings for Evolutionary Processes,"In this article, we study branching random walks on graphs modeling
+division-mutation processes inspired by adaptive immunity. We apply the theory
+of expander graphs on mutation rules in evolutionary processes and obtain
+estimates for the cover times of the branching random walks. This analysis
+reveals an unexpected saturation phenomenon : increasing the mutation rate
+above a certain threshold does not enhance the speed of state-space
+exploration.",1607.00927v1
+2016-08-15,Narumi-Katayama Index of Total Transformation Graphs,"The Narumi-Katayama index of a graph was introduced in 1984 for representing
+the carbon skeleton of a saturated hydrocarbons and is defined as the product
+of degrees of all the vertices of the graph. In this paper, we examine the
+Narumi-Katayama index of different total transformation graphs.",1608.04319v1
+2016-08-16,Saturation effects in low-x DIS structure functions and related hadronic total cross sections,"High-energy nucleon total cross sections are related to low-x DIS structure
+functions by using the additive quark model.",1608.04646v1
+2016-09-21,An Indecomposable and unconditionally saturated Banach space,"We construct an indecomposable reflexive Banach space $X_{ius}$ such that
+every infinite dimensional closed subspace contains an unconditional basic
+sequence. We also show that every operator $T\in \mathcal{B}(X_{ius})$ is of
+the form $\lambda I+S$ with $S$ a strictly singular operator.",1609.06509v1
+2016-11-01,Two-dimensional extremely short optical pulses in silicene with random electric fields,"We investigate an influence of the random external electric field on the 2D
+extremely short optical pulses propagation in the silicene. The random electric
+field is perpendicular to the silicene plane. An effective equation has the
+form of a wave equation with saturating nonlinearity. We analyze the
+dependences of the electromagnetic field intensity on the parameters of a
+problem.",1611.01106v1
+2016-11-14,Control of Fusion by Abelian Subgroups of the Hyperfocal Subgroup,"We prove that an isomorphism between saturated fusion systems over the same
+finite p-group is detected on the elementary abelian subgroups of the
+hyperfocal subgroup if p is odd, and on the abelian subgroups of the hyperfocal
+subgroup of exponent at most 4 if p = 2. For odd p, this has implications for
+mod p group cohomology.",1611.04403v1
+2016-11-14,On the quasi-$\mathfrak{F}$-hypercenter of a finite group,"In this paper some properties of the $\mathfrak{F}^*$-hypercenter of a finite
+group are studied where $\mathfrak{F}^*$ is the class of all finite
+quasi-$\mathfrak{F}$-groups for a hereditary saturated formation $\mathfrak{F}$
+of finite groups. In particular, it is shown that the quasinilpotent
+hypercenter of a finite group coincides with the intersection of all maximal
+quasinilpotent subgroups.",1611.04507v1
+2016-11-28,The Nonlinear Theory of FEL,"The nonlinear theory of relyativistic strophotron is developed. Classical
+equations of motion are averaged over fast oscillations. The slow motion phase
+and saturation parameter are found different from usual undulator oscillation
+parameters. In the strong field approximation the analytical expression of gain
+is found on higher harmonics of main resonance frequency.",1611.09249v2
+2017-06-01,"Quantales and their modules: projective objects, ideals, and congruences","In this paper we characterize the projective modules over an arbitrary
+quantale, and then we apply such a characterization in order to define the K_0
+group of a quantale. Then we study congruences of quantales and quantale
+modules by means of their ideals and of saturated elements w.r.t. a binary
+relation.",1706.00135v1
+2017-07-13,The study on quantum material WTe2,"WTe2 and its sister alloys have attracted tremendous attentions recent years
+due to the large non-saturating magnetoresistance and topological non-trivial
+properties. Herein, we briefly review the electrical property studies on this
+new quantum material.",1707.04132v1
+2017-09-06,Chaos in Saw Map,"We consider dynamics of a scalar piecewise linear ""saw map"" with infinitely
+many linear segments. In particular, such maps are generated as a Poincar\'e
+map of simple two-dimensional discrete time piecewise linear systems involving
+a saturation function. Alternatively, these systems can be viewed as a feedback
+loop with the so-called stop hysteresis operator. We analyze chaotic sets and
+attractors of the ""saw map"" depending on its parameters.",1709.01962v1
+2017-09-11,Dual virtual element method in presence of an inclusion,"We consider a Darcy problem for saturated porous media written in dual
+formulation in presence of a fully immersed inclusion. The lowest order virtual
+element method is employ to derive the discrete approximation. In the present
+work we study the effect of cells with cuts on the numerical solution, able to
+geometrically handle in a more natural way the inclusion tips. The numerical
+results show the validity of the proposed approach.",1709.03519v1
+2017-09-25,Star Saturation Number of Random Graphs,"For a given graph $F$, the $F$-saturation number of a graph $G$ is the
+minimum number of edges in an edge-maximal $F$-free subgraph of $G$. Recently,
+the $F$-saturation number of the Erd\H{o}s$\text{\bf--}$R\'enyi random graph
+$\mathbbmsl{G}(n, p)$ has been determined asymptotically for any complete graph
+$F$. In this paper, we give an asymptotic formula for the $F$-saturation number
+of $\mathbbmsl{G}(n, p)$ when $F$ is a star graph.",1709.08433v1
+2017-10-09,The small index property for homogeneous models in AECs,"We prove a version of a small index property theorem for strong amalgamation
+classes. Our result builds on an earlier theorem by Lascar and Shelah (in their
+case, for saturated models of uncountable first-order theories). We then study
+versions of the small index property for various non-elementary classes. In
+particular, we obtain the small index property for quasiminimal pregeometry
+structures.",1710.02920v1
+2017-10-19,Fusion systems containing pearls,"An $\mathcal{F}$-essential subgroup is called a pearl if it is either
+elementary abelian of order $p^2$ or non-abelian of order $p^3$. In this paper
+we start the investigation of fusion systems containing pearls: we determine a
+bound for the order of $p$-groups containing pearls and we classify the
+saturated fusion systems on $p$-groups containing pearls and having sectional
+rank at most $4$.",1710.07088v2
+2017-11-12,Double plasma resonance instability as a source of solar zebra emission,"The double plasma resonance (DPR) instability plays a basic role in the
+generation of solar radio zebras. In the plasma, consisting of the loss-cone
+type distribution of hot electrons and much denser and colder background
+plasma, this instability generates the upper-hybrid waves, which are then
+transformed into the electromagnetic waves and observed as radio zebras. In the
+present paper we numerically study the double plasma resonance instability from
+the point of view of the zebra interpretation. We use a 3-dimensional
+electromagnetic particle-in-cell (3-D PIC) relativistic model. First using the
+multi-mode model, we study details of the double plasma resonance instability.
+We show how the distribution function of hot electrons changes during this
+instability. Then we show that there is a very good agreement between results
+obtained by the multi-mode and specific-mode models, which is caused by a
+dominance of the wave with the maximal growth rate. Therefore, for computations
+in a broad range of model parameters, we use the specific-mode model. We
+compute the maximal growth rates of the double plasma resonance instability.
+The results are compared with the analytical ones. We find a very good
+agreement between numerical and analytical growth rates. We also compute
+saturation energies of the upper-hybrid waves in a very broad range of
+parameters. We find that the saturation energies of the upper-hybrid waves show
+maxima and minima at almost the same values of
+$\omega_\mathrm{UH}/\omega_\mathrm{ce}$ as the growth rates. Furthermore, we
+find that the saturation energy of the upper-hybrid waves is proportional to
+the density of hot electrons. The maximum saturated energy can be up to one
+percent of the kinetic energy of hot electrons. All these findings can be used
+in the interpretation of solar radio zebras.",1711.04281v1
+2017-11-23,Hidden attractors in aircraft control systems with saturated inputs,"In the paper, the control problem with limitations on the magnitude and rate
+of the control action in aircraft control systems, is studied. Existence of
+hidden oscillations in the case of actuator position and rate limitations is
+demonstrated by the examples of piloted aircraft pilot involved oscillations
+(PIO) phenomenon and the airfoil flutter suppression system.",1711.10302v1
+2017-12-08,$\mathcal{N}=2$ SCFT with minimal flavor central charge,"We list 4d interacting $\mathcal{N}=2$ SCFT with minimal flavor central
+charge from the theory space constructed using 6d $(2,0)$ theory. For $ADE$ and
+$C_N$ flavor groups, our theory saturates the bound found using bootstrap
+method, but other cases have higher values. We find interesting rank one SCFTs
+with $B_3, G_2, F_4, C_4\times U(1), C_1\times U(1)$ flavor symmetry. Many
+physical properties of these theories are also studied.",1712.03244v1
+2018-01-10,Recovery of Binary Sparse Signals with Biased Measurement Matrices,"This work treats the recovery of sparse, binary signals through
+box-constrained basis pursuit using biased measurement matrices. Using a
+probabilistic model, we provide conditions under which the recovery of both
+sparse and saturated binary signals is very likely. In fact, we also show that
+under the same condition, the solution of the boxed-constrained basis pursuit
+program can be found using boxed-constrained least-squares.",1801.03381v1
+2018-01-16,Centralizers of normal subsystems revisited,"In this paper we revisit two concepts which were originally introduced by
+Aschbacher and are crucial in the theory of saturated fusion systems: Firstly,
+we give a new approach to defining the centralizer of a normal subsystem.
+Secondly, we revisit the construction of the product of two normal subsystems
+which centralize each other.",1801.05256v2
+2018-04-10,Counterexamples for Cohen-Macaulayness of Lattice Ideals,"Let $\mathscr{L}\subset \mathbb{Z}^n$ be a lattice, $I$ its corresponding
+lattice ideal, and $J$ the toric ideal arising from the saturation of
+$\mathscr{L}$. We produce infinitely many examples, in every codimension, of
+pairs $I,J$ where one of these ideals is Cohen--Macaulay but the other is not.",1804.03647v1
+2018-04-19,On Bogomolny equations in the Skyrme model,"Using the concept of strong necessary conditions (CSNC), we derive a complete
+decomposition of the minimal Skyrme model into a sum of three coupled BPS
+submodels with the same topological bound. The bounds are saturated if
+corresponding Bogomolny equations, different for each submodel, are obeyed.",1804.09020v1
+2018-06-11,Discontinuous Galerkin method for coupling hydrostatic free surface flows to saturated subsurface systems,"We formulate a coupled surface/subsurface flow model that relies on
+hydrostatic equations with free surface in the free flow domain and on the
+Darcy model in the subsurface part. The model is discretized using the local
+discontinuous Galerkin method, and a statement of discrete energy stability is
+proved for the fully non-linear coupled system.",1806.03909v1
+2018-08-09,On Toric Orbits in the Affine Sieve,"We give a detailed analysis of a heuristic model for the failure of
+""saturation"" in instances of the Affine Sieve having toral Zariski closure.
+Based on this model, we formulate precise conjectures on several classical
+problems of arithmetic interest, and test these against empirical data.",1808.03235v1
+2018-09-06,GANs beyond divergence minimization,"Generative adversarial networks (GANs) can be interpreted as an adversarial
+game between two players, a discriminator D and a generator G, in which D
+learns to classify real from fake data and G learns to generate realistic data
+by ""fooling"" D into thinking that fake data is actually real data. Currently, a
+dominating view is that G actually learns by minimizing a divergence given that
+the general objective function is a divergence when D is optimal. However, this
+view has been challenged due to inconsistencies between theory and practice. In
+this paper, we discuss of the properties associated with most loss functions
+for G (e.g., saturating/non-saturating f-GAN, LSGAN, WGAN, etc.). We show that
+these loss functions are not divergences and do not have the same equilibrium
+as expected of divergences. This suggests that G does not need to minimize the
+same objective function as D maximize, nor maximize the objective of D after
+swapping real data with fake data (non-saturating GAN) but can instead use a
+wide range of possible loss functions to learn to generate realistic data. We
+define GANs through two separate and independent D maximization and G
+minimization steps. We generalize the generator step to four new classes of
+loss functions, most of which are actual divergences (while traditional G loss
+functions are not). We test a wide variety of loss functions from these four
+classes on a synthetic dataset and on CIFAR-10. We observe that most loss
+functions converge well and provide comparable data generation quality to
+non-saturating GAN, LSGAN, and WGAN-GP generator loss functions, whether we use
+divergences or non-divergences. These results suggest that GANs do not conform
+well to the divergence minimization theory and form a much broader range of
+models than previously assumed.",1809.02145v1
+2018-10-19,A Survey on The Ideal Structure of Leavitt Path Algebras,"There is an extensive recent literature on the graded, non-graded, prime,
+primitive, maximal ideals of Leavitt path algebras. In this introductory level
+survey, we will be giving an overview of different types of ideals and the
+correspondence between the lattice of ideals and the lattice of hereditary and
+saturated subsets of the graph over which the Leavitt path algebra is
+constructed.",1810.08602v1
+2018-10-22,Keisler's order via Boolean ultrapowers,"In this paper, we provide a new characterization of Keisler's order in terms
+of saturation of Boolean ultrapowers. To do so, we apply and expand the
+framework of 'separation of variables' recently developed by Malliaris and
+Shelah. We also show that good ultrafilters on Boolean algebras are precisely
+the ones which capture the maximum class in Keisler's order, answering a
+question posed by Benda in 1974.",1810.09428v2
+2019-01-04,Local saturation and square everywhere,"We show that it is consistent relative to a huge cardinal that for all
+infinite cardinals $\kappa$, $\square_\kappa$ holds and there is a stationary
+$S \subseteq \kappa^+$ such that $\mathrm{NS}_{\kappa^+} \restriction S$ is
+$\kappa^{++}$-saturated.",1901.02821v4
+2019-02-13,HADES RV Programme with HARPS-N at TNG. X. The non-saturated regime of the stellar activity-rotation relationship for M-Dwarfs,"Aims. We aim to extend the relationship between X-ray luminosity (Lx) and
+rotation period (Prot) found for main-sequence FGK stars and test whether it
+also holds for early-M dwarfs, especially in the non-saturated regime (Lx
+{\alpha} P_{rot}^{-2}) which corresponds to slow rotators. Methods. We use the
+luminosity coronal activity indicator (Lx) of a sample of 78 early-M dwarfs
+with masses in the range from 0.3 to 0.75 Msun from the HArps-N red Dwarf
+Exoplanet Survey (HADES) radial velocity (RV) programme collected from ROSAT
+and XMM-Newton. The determination of the rotation periods (P_{rot}) was done by
+analysing time-series of high-resolution spectroscopy of the Ca ii H & K and
+H{\alpha} activity indicators. Our sample principally covers the slow rotation
+regime with rotation periods from 15 to 60 days. Results. Our work extends to
+the low mass regime the observed trend for more massive stars showing a
+continuous shift of the Lx/Lbol vs. Prot power-law towards longer rotation
+period values and includes the determination, in a more accurate way, of the
+value of the rotation period at which the saturation occurs (P_{sat}) for M
+dwarf stars. Conclusions. We conclude that the relations between coronal
+activity and stellar rotation for FGK stars also hold for early-M dwarfs in the
+non-saturated regime, indicating that the rotation period is sufficient to
+determine the ratio Lx/Lbol.",1902.04868v1
+2019-02-26,Dynamics of fracturing saturated porous media and self-organization of rupture,"Analytical solutions and a vast majority of numerical ones for fracture
+propagation in saturated porous media yield smooth behavior while experiments,
+field observations and a few numerical solutions reveal stepwise crack
+advancement and pressure oscillations. To explain this fact, we invoke
+self-organization of rupture observed in fracturing solids, both dry and fully
+saturated, when two requirements are satisfied: i) the external drive has a
+much slower timescale than fracture propagation; and ii) the increment of the
+external load (drive) is applied only when the internal rearrangement of
+fracture is over. These requirements are needed to obtain clean Self Organised
+Criticality (SOC) in quasi-static situations. They imply that there should be
+no restriction on the fracture velocity i.e. algorithmically the fracture
+advancement rule should always be independent of the crack velocity. Generally,
+this is not the case when smooth answers are obtained which are often
+unphysical. Under the above conditions hints of Self Organized Criticality are
+evident in heterogeneous porous media in quasi-static conditions using a
+lattice model, showing stepwise advancement of the fracture and pressure
+oscillations. We extend this model to incorporate inertia forces and show that
+this behavior still holds. By incorporating the above requirements in numerical
+fracture advancement algorithms for cohesive fracture in saturated porous
+continua we also reproduce stepwise advancements and pressure oscillations both
+in quasi-static and dynamic situations. Since dynamic tests of dry specimens
+show that the fracture advancement velocity is not constant we replicate such
+an effect with a model of a debonding beam on elastic foundation. This is the
+first step before introducing the interaction with a fluid.",1902.10082v1
+2019-03-13,Cryogenic Subthreshold Swing Saturation in FD-SOI MOSFETs described with Band Broadening,"In the standard MOSFET description of the drain current $I_{D}$ as a function
+of applied gate voltage $V_{GS}$, the subthreshold swing $SS(T)\equiv
+dV_{GS}/d\log I_{D}$ has a fundamental lower limit as a function of temperature
+$T$ given by $SS(T) = \ln10~k_BT/e$. However, recent low-temperature studies of
+different advanced CMOS technologies have reported $SS$(4K or lower) values
+that are at least an order of magnitude larger. Here, we present and analyze
+the saturation of $SS(T)$ in 28nm fully-depleted silicon-on-insulator (FD-SOI)
+devices for both n- and p-type MOSFETs of different gate oxide thicknesses and
+gate lengths down to 4K. Until now, the increase of interface-trap density
+close to the band edge as temperature decreases has been put forward to
+understand the saturation. Here, an original explanation of the phenomenon is
+presented by considering a disorder-induced tail in the density of states at
+the conduction (valence) band edge for the calculation of the MOS channel
+transport by applying Fermi-Dirac statistics. This results in a subthreshold
+$I_{D}\sim e^{eV_{GS}/k_BT_0}$ for $T_0=35$K with saturation value $SS(T<T_0) =
+\ln 10~k_BT_0/e$. The proposed model adequately describes the experimental data
+of $SS(T)$ from 300 down to 4K using $k_BT_0 \simeq 3$meV for the width of the
+exponential tail and can also accurately describe $SS(I_{D})$ within the whole
+subthreshold region. Our analysis allows a direct determination of the
+technology-dependent band-tail extension forming a crucial element in future
+compact modeling and design of cryogenic circuits.",1903.05409v1
+2019-04-17,Controlling group and phase velocities in bidirectional mode-locked fiber lasers,"A bidirectional mode-locked fiber laser producing two correlated frequency
+combs of the same repetition rate is demonstrated. The intensity dependence of
+pulse and phase velocities are measured simultaneously. As expected, the phase
+delay is determined by the linear and nonlinear indices of refraction. The
+nonlinear Kerr effect contribution to the pulse velocity is dwarfed by a
+contribution from saturable gain dynamics.",1904.08132v1
+2019-06-14,Signed Radon measure-valued solutions of flux saturated scalar conservation laws,"We prove existence and uniqueness for a class of signed Radon measure-valued
+entropy solutions of the Cauchy problem for a first order scalar hyperbolic
+conservation law in one space dimension. The initial data of the problem is a
+finite superposition of Dirac masses, whereas the flux is Lipschitz continuous
+and bounded. The solution class is determined by an additional condition which
+is needed to prove uniqueness.",1906.06230v1
+2019-07-20,ITMD factorization and broadening effects in production of forward di-jets,"I report on the recent result of comparison of forward-forward dijet
+correlations in azimuthal angle as measured by the ATLAS collaboration in the
+proton-proton and proton-lead collisions to calculations within ITMD
+factorization framework [1]. The comparison shows that the broadening effect
+due to interplay of both the gluon saturation and the Sudakov resummation is
+necessary to describe the data.",1907.08794v1
+2019-11-22,A stochastic approach to enhanced diffusion,"We provide examples of initial data which saturate the enhanced diffusion
+rates proved for general shear flows which are H\""{o}lder regular or Lipschitz
+continuous with critical points, and for regular circular flows, establishing
+the sharpness of those results. Our proof makes use of a probabilistic
+interpretation of the dissipation of solutions to the advection diffusion
+equation.",1911.09995v1
+2019-12-03,The Penrose inequality for perturbations of the Schwarzschild initial data,"We show that in the conformally flat case the Penrose inequality is satisfied
+for the Schwarzschild initial data with a small addition of the axially
+symmetric traceless exterior curvature. In this class the inequality is
+saturated only for data related to special sections of the Schwarzschild
+spacetime.",1912.01301v1
+2019-12-16,R-group and Whittaker space of some genuine representations,"For a unitary unramified genuine principal series representation of a
+covering group, we study the associated R-group. We prove a formula relating
+the R-group to the dimension of the Whittaker space for the irreducible
+constituents of such a principal series representation. Moreover, for saturated
+covers of a semisimple simply-connected group, we also propose a simpler
+conjectural formula for such dimensions. This latter conjectural formula is
+verified in several cases, including covers of the symplectic groups.",1912.07408v1
+2019-12-28,Exclusive diffractive processes including saturation effects at next-to-leading order,"In the framework of the QCD shock-wave approach, we review our results on the
+description of diffractive production of various final states (jets, meson) at
+next-to-leading order. This is applied to exclusive diffractive dijet
+electroproduction at HERA.",1912.12434v1
+2020-03-07,A Study of Selectively Digital Etching Silicon-Germanium with Nitric and Hydrofluoric Acids,"A digital etching method was proposed to achieve excellent control of etching
+depth. The digital etching characteristics of p+ Si and Si0.7Ge0.3 using the
+combinations of HNO3 oxidation and BOE oxide removal processes were studied.
+Experiments showed that oxidation saturates with time due to low activation
+energy. A physical model was presented to describe the wet oxidation process
+with nitric acid. The model was calibrated with experimental data and the
+oxidation saturation time, final oxide thickness, and selectivity between
+Si0.7Ge0.3 and p+ Si were obtained. The digital etch of laminated Si0.7Ge0.3/p+
+Si was also investigated. The depth of the tunnels formed by etching SiGe
+layers between two Si layers was found in proportion to digital etching cycles.
+And oxidation would also saturate and the saturated relative etched amount per
+cycle (REPC) was 0.5 nm (4 monolayers). A corrected selectivity calculation
+formula was presented. The oxidation model was also calibrated with
+Si0.7Ge0.3/p+ Si stacks, and selectivity from model was the same with the
+corrected formula. The model can also be used to analyze process variations and
+repeatability. And it could act as a guidance for experiment design.
+Selectivity and repeatability should make a trade-off.",2003.03529v1
+2020-03-10,Fusion systems on a Sylow $p$-subgroup of $SU_4(p)$,"We determine, for $p$ odd, all saturated fusion systems on a Sylow
+$p$-subgroup $S$ of the unitary group $SU_4(p)$ and we prove that they are all
+realizable by finite groups. In particular, we prove that $S$ does not support
+any exotic fusion systems.",2003.04842v2
+2020-04-27,Metasurfaces help lasers to mode-lock,"Metasurface saturable absorbers may result in versatile mode-locking that
+allows one to obtain stable ultrashort laser pulses with high repetition rates
+and peak powers, along with broadband operation, within fiber to solid-state
+laser cavities.",2004.12596v1
+2020-06-07,In-Ear Measurement of Blood Oxygen Saturation: An Ambulatory Tool Needed To Detect The Delayed Life-Threatening Hypoxaemia in COVID-19,"Non-invasive ambulatory estimation of blood oxygen saturation has emerged as
+an important clinical requirement to detect hypoxemia in the delayed
+post-infective phase of COVID-19, where dangerous hypoxia may occur in the
+absence of subjective breathlessness. This immediate clinical driver, combined
+with the general quest for more personalised health data, means that pulse
+oximetry measurement of capillary oxygen saturation (SpO2) will likely expand
+into both the clinical and consumer market of wearable health technology in the
+near future. In this study, we set out to establish the feasibility of SpO2
+measurement from the ear canal as a convenient site for long term monitoring,
+and perform a comprehensive comparison with the right index finger - the
+conventional clinical measurement site. During resting SpO2 estimation, we
+found a root mean square difference of 1.47% between the two measurement sites,
+with a mean difference of 0.23% higher SpO2 in the right ear canal. Through the
+simultaneous recording of pulse oximetry from both the right ear canal and
+index finger during breath holds, we observe a substantial improvement in
+response time between the ear and finger that has a mean of 12.4 seconds and a
+range of 4.2 - 24.2 seconds across all subjects. Factors which influence this
+response time, termed SpO2 delay, such as the sex of a subject are also
+explored. Furthermore, we examine the potential downsides of ear canal blood
+oxygen saturation measurement, namely the lower photoplethysmogram amplitude,
+and suggest ways to mitigate this disadvantage. These results are presented in
+conjunction with previously discovered benefits such as robustness to
+temperature, making the case for measurement of SpO2 from the ear canal being
+both convenient and superior to conventional finger measurement sites for
+continuous non-intrusive long term monitoring in both clinical and
+everyday-life settings.",2006.04231v1
+2020-10-26,The logarithmic Bogomolov-Tian-Todorov theorem,"We prove that the log smooth deformations of a proper log smooth saturated
+log Calabi-Yau space are unobstructed.",2010.13656v3
+2020-11-06,Upper bounds for Betti numbers from constraints on the Hilbert function,"We describe an algorithm for finding sharp upper bounds for the total Betti
+numbers of a saturated ideal given certain constraints on its Hilbert function.
+This algorithm is implemented in the Macaulay2 package, MaxBettiNumbers, along
+with variations that produce ideals with maximal total Betti numbers.",2011.03401v1
+2021-03-25,Random walker derivation of Archie's law,"The empirical Archie's law, relating the measured electrical resistivity of
+an electrolyte-saturated rock to its connected porosity, is derived by
+consideration of the fractal character of the pore space. The derivation thus
+imposes some conditions on the implementation and meaning of Archie's law.",2103.14099v1
+2021-05-05,Hennessy-Milner Properties via Topological Compactness,"We give Hennessy-Milner classes for intuitionistic, dual-intuitionistic and
+bi-intuitionistic logic interpreted in intuitionistic Kripke models, and
+generalise these results to modal (dual- and bi-)intuitionistic logics. Our
+main technical tools are image-compact and pre-image-compact relations that
+provide a semantical description of modal saturation properties.",2105.01855v1
+2021-05-28,Poisson catenarity in Poisson nilpotent algebras,"We prove that for the iterated Poisson polynomial rings known as Poisson
+nilpotent algebras (or Poisson-CGL extensions), the Poisson prime spectrum is
+catenary, i.e., all saturated chains of inclusions of Poisson prime ideals
+between any two given Poisson prime ideals have the same length.",2105.13737v1
+2021-06-13,Uniform in time $L^\infty$-estimates for an attraction-repulsion chemotaxis system with double saturation,"In this paper we focus on an attraction-repulsion chemotaxis model with
+consumed signals, formulated in bounded and smooth domains $\Omega$ of $\R^n$,
+with $n\geq 2$. We derive sufficient conditions on its data yielding global and
+bounded classical solutions to the related zero-flux Cauchy problem.",2106.07038v2
+2021-07-20,Normalizers of sets of components in fusion systems,"We describe some new ways to construct saturated fusion subsystems,
+including, as a special case, the normalizer of a set of components of the
+ambient fusion system. This was motivated in part by Aschbacher's construction
+of the normalizer of one component, and in part by joint work with three other
+authors where we had to construct the normalizer of all of the components.",2107.09494v2
+2021-09-01,Small Strong Blocking Sets by Concatenation,"Strong blocking sets and their counterparts, minimal codes, attracted lots of
+attention in the last years. Combining the concatenating construction of codes
+with a geometric insight into the minimality condition, we explicitly provide
+infinite families of small strong blocking sets, whose size is linear in the
+dimension of the ambient projective spaces. As a byproduct, small saturating
+sets are obtained.",2109.00584v2
+2021-09-28,Normalizers and centralizers of subnormal subsystems of fusion systems,"Every saturated fusion system corresponds to a group-like structure called a
+regular locality. In this paper we study (suitably defined) normalizers and
+centralizers of partial subnormal subgroups of regular localities. This leads
+to a reasonable notion of normalizers and centralizers of subnormal subsystems
+of fusion systems.",2109.14038v2
+2022-02-11,Saturable time-varying mirror based on an ENZ material,"We report a switchable time-varying mirror, composed of an ITO-Au stack,
+which can be efficiently modulated in time with over a ten-fold increase in
+reflectivity, with a change of 0.6. Upon interacting with the time-varying
+mirror, the frequency content of a reflected pulse is extended to 31 THz. This
+originates from the shortening of the response time of the mirror beyond
+saturation, as confirmed by a time-varying model and by further four-wave
+mixing experiments. A temporal response unbounded by the pump bandwidth opens
+new avenues for spectral manipulation from time-varying systems with impact for
+communication networks, optical switching and computing.
+  We report a switchable time-varying mirror, composed of an ITO-Au bilayer,
+displaying a ten-fold modulation of reflectivity ($\Delta R \approx 0.6$),
+which saturates for a driving pump intensity $I_{\mathrm{pump}}\approx
+100$~GW/cm$^2$. Upon interacting with the saturated time-varying mirror, the
+frequency content of a reflected pulse is extended up to 31 THz, well beyond
+the pump spectral content (2.8 THz). We interpret the spectral broadening as a
+progressive shortening of the mirror rise time from 110 fs to sub 30 fs with
+increasing pump power, which is confirmed by four-wave mixing experiments and
+partially captured by a linear time-varying model of the mirror. A temporal
+response unbounded by the pump bandwidth opens new avenues for spectral
+manipulation from time-varying systems with impact for communication networks,
+optical switching and computing.",2202.05937v4
+2022-02-23,Miscellaneous problems about packing and covering,"In this paper we discuss various special problems on packing and covering.
+Among others we survey the problems and results concerning finite arrangements,
+Minkowskian, saturated, compact, and totally separable packings. We discuss
+shortest path problems and questions about stability of packings.",2202.11366v1
+2022-04-13,On chains associated with abstract key polynomials,"In this paper, for a henselian valued field $(K, v)$ of arbitrary rank and an
+extension $w$ of $v$ to $K(X),$ we use abstract key polynomials for $w$ to give
+a connection between complete sets, saturated distinguished chains and Okutsu
+frames. Further, for a valued field $(K, v),$ we also obtain a close connection
+between complete set of ABKPs for $w$ and Maclane-Vaqui\'e chains of $w.$",2204.06428v1
+2022-08-11,A nonlinear attraction-repulsion Keller-Segel model with double sublinear absorptions: criteria toward boundedness,"This paper generalizes and extends to the case of nonlinear effects and
+logistic perturbations some results recently developed in the literature where,
+for the linear counterpart and in absence of logistics, criteria toward
+boundedness for an attraction-repulsion Keller-Segel system with double
+saturation are derived.",2208.05678v1
+2022-12-07,Compactness in Team Semantics,"We provide two proofs of the compactness theorem for extensions of
+first-order logic based on team semantics. First, we build upon L\""uck's
+ultraproduct construction for team semantics and prove a suitable version of
+{\L}o\'s' Theorem. Second, we show that by working with suitably saturated
+models, we can generalize the proof of Kontinen and Yang to sets of formulas
+with arbitrarily many variables.",2212.03677v1
+2022-12-12,Tight concentration of star saturation number in random graphs,"For given graphs $F$ and $G$, the minimum number of edges in an
+inclusion-maximal $F$-free subgraph of $G$ is called the $F$-saturation number
+and denoted $\mathrm{sat}(G, F)$. For the star $F=K_{1,r}$, the asymptotics of
+$\mathrm{sat}(G(n,p),F)$ is known. We prove a sharper result: whp
+$\mathrm{sat}(G(n,p), K_{1,r})$ is concentrated in a set of 2 consecutive
+points.",2212.06101v1
+2022-12-16,On maximal rational poylhedral fans,"In this paper we study the geometry and combinatorics of the possible
+rational polyhedral fans with a given set of rays.
+  The main questions we consider are when such fans are projective, complete,
+or simplicial. To answer these questions we use techniques of invariant theory
+to characterize the quotients of maximal saturated open sets in torus
+representations.",2212.08240v1
+2023-01-19,Spanning the full range of neutron star properties within a microscopic description,"The high-density behavior of nuclear matter is analyzed within a relativistic
+mean-field description with non-linear meson interactions. To assess the model
+parameters and their output, a Bayesian inference technique is used. The
+Bayesian setup is limited only by a few nuclear saturation properties, the
+neutron star maximum mass larger than 2 M$_\odot$, and the low-density pure
+neutron matter equation of state (EOS) produced by an accurate N$^3$LO
+calculation in chiral effective field theory. Depending on the strength of the
+non-linear scalar vector field contribution, we have found three distinct
+classes of EOSs, each one correlated to different star properties
+distributions. If the non-linear vector field contribution is absent, the
+gravitational maximum mass and the sound velocity at high densities are the
+greatest. However, it also gives the smallest speed of sound at densities below
+three times saturation density. On the other hand, models with the strongest
+non-linear vector field contribution predict the largest radii and tidal
+deformabilities for 1.4 M$_\odot$ stars, together with the smallest mass for
+the onset of the nucleonic direct Urca processes and the smallest central
+baryonic densities for the maximum mass configuration. These models have the
+largest speed of sound below three times saturation density, but the smallest
+at high densities, in particular, above four times saturation density the speed
+of sound decreases approaching approximately $\sqrt{0.4}c$ at the center of the
+maximum mass star. On the contrary, a weak non-linear vector contribution gives
+a monotonically increasing speed of sound. A 2.75 M$_\odot$ NS maximum mass was
+obtained in the tail of the posterior with a weak non-linear vector field
+interaction. We found that pQCD favors models with a large non-linear vector
+field contribution or hyperons.",2301.08169v4
+2023-01-19,A note on five dimensional kissing arrangements,"The kissing number $\tau(d)$ is the maximum number of pairwise
+non-overlapping unit spheres each touching a central unit sphere in the
+$d$-dimensional Euclidean space. In this note we report on how we discovered a
+new, previously unknown arrangement of $40$ unit spheres in dimension $5$. Our
+arrangement saturates the best known lower bound on $\tau(5)$, and refutes a
+`belief' of Cohn--Jiao--Kumar--Torquato.",2301.08272v1
+2023-01-22,On the size of maximum cut in planar graphs,"We show that the size of maximum cut in a planar graph with $m$ edges is at
+least $2m/3$. We also show that maximal planar graphs saturate this bound.",2301.09170v2
+2023-01-24,Margolus-Levitin quantum speed limit for an arbitrary fidelity,"The Mandelstam-Tamm and Margolus-Levitin quantum speed limits are two
+well-known evolution time estimates for isolated quantum systems. These bounds
+are usually formulated for fully distinguishable initial and final states, but
+both have tight extensions to systems that evolve between states with an
+arbitrary fidelity. However, the foundations of these extensions differ in some
+essential respects. The extended Mandelstam-Tamm quantum speed limit has been
+proven analytically and has a clear geometric interpretation. Furthermore,
+which systems saturate the limit is known. The derivation of the extended
+Margolus-Levitin quantum speed limit, on the other hand, is based on numerical
+estimates. Moreover, the limit lacks a geometric interpretation, and no
+complete characterization of the systems reaching it exists. In this paper, we
+derive the extended Margolus-Levitin quantum speed limit analytically and
+describe the systems that saturate the limit in detail. We also provide the
+limit with a symplectic-geometric interpretation, which indicates that it is of
+a different character than most existing quantum speed limits. At the end of
+the paper, we analyze the maximum of the extended Mandelstam-Tamm and
+Margolus-Levitin quantum speed limits and derive a dual version of the extended
+Margolus-Levitin quantum speed limit. The maximum limit is tight regardless of
+the fidelity of the initial and final states. However, the conditions under
+which the maximum limit is saturated differ depending on whether or not the
+initial state and the final state are fully distinguishable. The dual limit is
+also tight and follows from a time reversal argument. We describe the systems
+that saturate the dual quantum speed limit.",2301.10063v3
+2023-02-09,The QCD shockwave approach at NLO: towards precision physics in gluonic saturation,"We review the recent developments of the QCD shockwave approach at
+Next-to-Leading Order. The general method of this effective action is sketched,
+and illustrated by the case of diffractive processes.",2302.04526v1
+2023-04-02,The variety of polar simplices II,"We discuss the space $VPS(Q,H)$ of ideals with Hilbert function $H=(1,n,n,
+\ldots )$ that are apolar to a full rank quadric $Q$. We prove that its
+components of saturated ideals are closely related to the locus of Gorenstein
+algebras and to the Slip component in border apolarity. We also point out an
+important error in~\cite{RS} and provide the necessary corrections.",2304.00533v1
+2023-04-26,A model of surface roughness effect on triboelectric charging of particles,"Tribocharging increases due to deformation and penetration of surface
+asperities, enlarging the real contact area. These experimental results
+translate into a theoretical description of particle charging that resolves the
+surface topology. Based on these findings, we propose a model that predicts the
+dependence of the particles' saturation charge on the impact velocity and
+surface roughness.",2304.13441v1
+2023-06-04,Global Transonic Solution of Hot Accretion Flow with Thermal Conduction,"We examine the effect of thermal conduction on the low-angular momentum hot
+accretion flow (HAF) around non-rotating black holes accreting mass at very low
+rate. While doing so, we adopt the conductive heat flux in the saturated form,
+and solve the set of dynamical equations corresponding to a steady,
+axisymmetric, viscous, advective accretion flow using numerical methods. We
+study the dynamical and thermodynamical properties of accreting matter in terms
+of the input parameters, namely energy ($\varepsilon_0$), angular momentum
+($\ell_0$), viscosity parameter ($\alpha$), and saturation constant ($\Phi_{\rm
+s}$) regulating the effect of thermal conduction. We find that $\Phi_{\rm s}$
+plays a pivotal role in deciding the transonic properties of the global
+accretion solutions. In general, when $\Phi_{\rm s}$ is increased, the critical
+point ($r_{\rm c}$) is receded away from the black hole, and flow variables are
+altered particularly in the outer part of the disc. To quantify the physically
+acceptable range of $\Phi_{\rm s}$, we compare the global transonic solutions
+with the self-similar solutions, and observe that the maximum saturation
+constant ($\Phi^{\rm max}_{\rm s}$) estimated from the global solutions exceeds
+the saturated thermal conduction limit ($\Phi_{\rm sc}$) derived from the
+self-similar formalism. Moreover, we calculate the correlation between $\alpha$
+and $\Phi^{\rm max}_{\rm s}$ and find ample disagreement between global
+solutions and self-similar solutions. Further, using the global flow variables,
+we compute the Bernoulli parameter ($Be$) which remains positive all throughout
+the disc, although flow becomes loosely unbound for higher $\Phi_{\rm s}$.
+Finally, we indicate the relevance of this work in the astrophysical context in
+explaining the possibility of massloss/outflows from the unbound disc.",2306.02453v1
+2023-06-20,Extremal bounds for pattern avoidance in multidimensional 0-1 matrices,"A 0-1 matrix $M$ contains another 0-1 matrix $P$ if some submatrix of $M$ can
+be turned into $P$ by changing any number of $1$-entries to $0$-entries. $M$ is
+$\mathcal{P}$-saturated where $\mathcal{P}$ is a family of 0-1 matrices if $M$
+avoids every element of $\mathcal{P}$ and changing any $0$-entry of $M$ to a
+$1$-entry introduces a copy of some element of $\mathcal{P}$. The extremal
+function ex$(n,\mathcal{P})$ and saturation function sat$(n,\mathcal{P})$ are
+the maximum and minimum possible weight of an $n\times n$
+$\mathcal{P}$-saturated 0-1 matrix, respectively, and the semisaturation
+function ssat$(n,P)$ is the minimum possible weight of an $n\times n$
+$\mathcal{P}$-semisaturated 0-1 matrix $M$, i.e., changing any $0$-entry in $M$
+to a $1$-entry introduces a new copy of some element of $\mathcal{P}$.
+  We study these functions of multidimensional 0-1 matrices. We give upper
+bounds on parameters of minimally non-$O(n^{d-1})$ $d$-dimensional 0-1
+matrices, generalized from minimally nonlinear 0-1 matrices in two dimensions,
+and we show the existence of infinitely many minimally non-$O(n^{d-1})$
+$d$-dimensional 0-1 matrices with all dimensions of length greater than $1$.
+For any positive integers $k,d$ and integer $r\in[0,d-1]$, we construct a
+family of $d$-dimensional 0-1 matrices with both extremal function and
+saturation function exactly $kn^r$ for sufficiently large $n$. We show that no
+family of $d$-dimensional 0-1 matrices has saturation function strictly between
+$O(1)$ and $\Theta(n)$ and we construct a family of $d$-dimensional 0-1
+matrices with bounded saturation function and extremal function
+$\Omega(n^{d-\epsilon})$ for any $\epsilon>0$. Up to a constant multiplicative
+factor, we fully settle the problem of characterizing the semisaturation
+function of families of $d$-dimensional 0-1 matrices, which we prove to always
+be $\Theta(n^r)$ for some integer $r\in[0,d-1]$.",2306.11934v1
+2023-09-27,The greatest GOES soft X-ray flares: Saturation and recalibration over two Hale cycles,"The solar soft X-ray observations from the GOES satellites provide one of the
+best quantitative records of solar activity, with nearly continuous flare
+records since 1975. We present a uniform analysis of the entire time series for
+1975 to 2022 at NOAA class C1 level or above, to characterize the occurrence
+distribution function (ODF) of the flares observed in the 1-8 A spectral band.
+The analysis includes estimations of the peak fluxes of the 12 flares that
+saturated the 1-8 A time series. Our new estimates include NOAA's recently
+established correction factor (1.43) to adjust the GOES-1 through GOES-15 data
+covering 1975-2016. For each of the 12 saturated events we have made new
+estimates of peak fluxes based on fits to the rise and fall of the flare time
+profile, and have validated our extrapolation schemes by comparing with
+artificially truncated but unsaturated X10-class events. SOL2003-11-04 now has
+a peak flux of 4.32e-3 W/m^2. This corresponds to X43 on the new scale, or X30
+on the old scale. We provide a list in the Appendix for peak fluxes of all 38
+events above 10^-3 W/m^2, the GOES X10 level, including the 12 saturated
+events. The full list now gives us a first complete sample from which we obtain
+an occurrence distribution function (ODF) for peak energy flux , often
+represented as a power law dF/dE ~ E^-alpha, for which we find alpha = 1.973 +-
+0.014 in the range M1 to X3. The power-law description fails at the high end,
+requiring a downward break in the ODF above the X10 level. We give a tapered
+powerlaw description of the resulting CCDF (complementary cumulative
+distribution function) and extrapolate it into the domain of ""superflares,""
+i.e. flares with bolometric energies > 10^33 erg. Extrapolation of this fit
+provides estimates of 100-yr and 1000-yr GOES peak fluxes that agree reasonably
+well with other such estimates using different data sets and methodology.",2310.11457v1
+2023-10-22,On the saturation number for singular cubic surfaces,"We investigate the distribution of rational points on singular cubic
+surfaces, whose coordinates have few prime factors. The key tools used are
+universal torsors, the circle method and results on linear equations in primes.",2310.14327v1
+2023-11-17,The Newton polytope of the Kronecker product,"We study the Kronecker product of two Schur functions $s_\lambda\ast s_\mu$,
+defined as the image of the characteristic map of the product of two $S_n$
+irreducible characters. We prove special cases of a conjecture of
+Monical--Tokcan--Yong that its monomial expansion has a saturated Newton
+polytope. Our proofs employ the Horn inequalities for positivity of
+Littlewood-Richardson coefficients and imply necessary conditions for the
+positivity of Kronecker coefficients.",2311.10276v1
+2023-12-10,Intermode coupling in a fiber loop laser at low temperatures,"We experimentally study an unequally-spaced optical comb (USOC), which is
+generated by a unidirectional fiber loop laser operated at low temperatures.
+The underlying mechanism responsible for USOC formation is explored using both
+close and open loop measurements. The role played by dispersion is investigated
+using radio frequency spectrum measurements. By integrating a saturable
+absorber into the loop, a lasing state is revealed, in which mode locking
+coexists with the USOC.",2312.05838v1
+2024-01-06,Local positive logic,"We develop the basic model theory of local positive logic, a new logic that
+mixes positive logic (where negation is not allowed) and local logic (where
+models omit types of infinite distant pairs). We study several basic model
+theoretic notions such as compactness, positive closedness (existential
+closedness), completeness (irreducibility), type spaces and retractors
+(saturated models).",2401.03260v1
+2024-01-08,Global entropy solutions to a degenerate parabolic-parabolic chemotaxis system for flux-limited dispersal,"Existence of global finite-time bounded entropy solutions to a
+parabolic-parabolic system proposed in [15] is established in bounded domains
+under no-flux boundary conditions for nonnegative bounded initial data. This
+modification of the classical Keller-Segel model features degenerate diffusion
+and chemotaxis that are both subject to flux-saturation. The approach is based
+on Schauder's fixed point theorem and calculus of functions of bounded
+variation.",2401.03887v1
+2024-02-12,A saturation theorem for submonoids of nilpotent groups and the Identity Problem,"If $M$ is a submonoid of a finitely generated nilpotent group $G$, and $MG'$
+is a finite index subgroup of $G$, then $M$ itself is a finite index subgroup
+of $G$. If $MG'=G$, then $M=G$. This generalizes a well-known theorem for
+subgroups of finitely generated nilpotent groups. As a result, we give an
+algorithm for the Identity Problem in nilpotent groups.",2402.07337v1
+2024-02-18,Criteria for nilpotency of fusion systems,"Let $p$ be an odd prime and let $\mathcal{F}$ be a fusion system over a
+finite $p$-group $P$. A fusion system $\mathcal{F}$ is said to be nilpotent if
+$\mathcal{F}=\mathcal{F}_{P}(P)$. In this paper we provide new criteria for
+saturated fusion systems $\mathcal{F}$ to be nilpotent, which can be viewed as
+extension of the $p$-nilpotency theorem of Glauberman and Thompson for fusion
+systems attributed to Kessar and Linckelmann.",2402.11629v1
+2002-11-03,Magnetically induced signatures in a thin film superconductor,"We study the interaction between a one dimensional magnetic nanostructure and
+a thin film superconductor. It is shown that different magnetic distributions
+produce characteristic magnetic field signatures. Moreover, the magnetic
+structure can induce a weak link in the superconducting film, or be positioned
+directly above a predefined nonsuperconducting weak link. We estimate the
+magnetic flux associated with such a structure, and discuss a general
+expression for the energy calculated within the London model.",0211043v1
+2004-09-25,Nano-mechanical magnetization reversal,"The dynamics of the ferromagnetic order parameter in thin magnetic films is
+strongly affected by the magnetomechanical coupling at certain resonance
+frequencies. By solving the equation of motion of the coupled mechanical and
+magnetic degrees of freedom we show that the magnetic-field induced
+magnetization switching can be strongly accelerated by the lattice and
+illustrate the possibility of magnetization reversal by mechanical actuation.",0409681v1
+2005-10-26,Ferroelectricity in spiral magnets,"It was recently observed that materials showing most striking multiferroic
+phenomena are frustrated spin-density-wave magnets. We present a simple
+phenomenological theory, which describes the orientation of the induced
+electric polarization for various incommensurate magnetic states, its
+dependence on temperature and magnetic field, and anomalies of dielectric
+susceptibility at magnetic transitions. We show that electric polarization can
+be induced at domain walls and that magnetic vortices carry electric charge.",0510692v1
+2007-07-13,Magnetic Flux Effects in Statistical Magnetism of Electron Gas,"The effects of magnetic flux in statistical magnetisms, including Pauli
+paramagnetism, Landau diamagnetism, and De Hass-van Alphen oscillation, are
+discussed. It is shown that the diamagnetism could be much increased by the
+fractional magnetic flux, and the amplitude of the magnetic oscillation of De
+Hass-van Alphen can be amplified by the quantum effect of the flux.",0707.1920v1
+2008-05-18,Effect of spin diffusion on spin torque in magnetic nanopillars,"We present systematic magnetoelectronic measurements of magnetic nanopillars
+with different structures of polarizing magnetic layers. The magnetic reversal
+at small magnetic field, the onset of magnetic dynamics at larger field, and
+the magnetoresistance exhibit a significant dependence on the type of the
+polarizing layer. We performed detailed quantitative modeling showing that the
+differences can be explained by the effects of spin-dependent electron
+diffusion.",0805.2706v1
+2012-06-05,Negative magnetic relaxation in superconductors,"It was observed that the trapped magnetic moment of HTS tablets or annuli
+increases in time (negative relaxation) if they are not completely magnetized
+by a pulsed magnetic field. It is shown, in the framework of the Bean
+critical-state model, that the radial temperature gradient appearing in tablets
+or annuli during a pulsed field magnetization can explain the negative magnetic
+relaxation in the superconductor.",1206.0861v1
+2016-08-19,Vesicles in magnetic fields,"Liposome vesicles tend to align with an applied magnetic field. This is due
+to the directional magnetic susceptibility difference of the lipids which form
+the membrane of these vesicles. In this work a model of liposome vesicles
+exposed to magnetic field is presented. Starting from the base energy of a
+lipid membrane in a magnetic field, the force applied to the surrounding fluids
+is derived. This force is then used to investigate the dynamics of vesicle in
+the presence of magnetic fields.",1608.05587v1
+2012-11-20,Magnetic Cluster Excitations,"Magnetic clusters, i.e., assemblies of a finite number (between two or three
+and several hundred) of interacting spin centers which are magnetically
+decoupled from their environment, can be found in many materials ranging from
+inorganic compounds, magnetic molecules, artificial metal structures formed on
+surfaces to metalloproteins. The magnetic excitation spectra in them are
+determined by the nature of the spin centers, the nature of the magnetic
+interactions, and the particular arrangement of the mutual interaction paths
+between the spin centers. Small clusters of up to four magnetic ions are ideal
+model systems to examine the fundamental magnetic interactions which are
+usually dominated by Heisenberg exchange, but often complemented by anisotropic
+and/or higher-order interactions. In large magnetic clusters which may
+potentially deal with a dozen or more spin centers, the possibility of novel
+many-body quantum states and quantum phenomena are in focus. In this review the
+necessary theoretical concepts and experimental techniques to study the
+magnetic cluster excitations and the resulting characteristic magnetic
+properties are introduced, followed by examples of small clusters demonstrating
+the enormous amount of detailed physical information which can be retrieved.
+The current understanding of the excitations and their physical interpretation
+in the molecular nanomagnets which represent large magnetic clusters is then
+presented, with an own section devoted to the subclass of the single-molecule
+magnets which are distinguished by displaying quantum tunneling of the
+magnetization. Finally, some quantum many-body states are summarized which
+evolve in magnetic insulators characterized by built-in or field-induced
+magnetic clusters. The review concludes addressing future perspectives in the
+field of magnetic cluster excitations.",1211.4688v1
+2014-01-08,Generating buoyant magnetic flux ropes in solar-like convective dynamos,"Our Sun exhibits strong convective dynamo action which results in magnetic
+flux bundles emerging through the stellar surface as magnetic spots.
+Global-scale dynamo action is believed to generate large-scale magnetic
+structures in the deep solar interior through the interplay of convection,
+rotation, and shear. Portions of these large-scale magnetic structures are then
+believed to rise through the convective layer, forming magnetic loops which
+then pierce the photosphere as sunspot pairs. Previous global simulations of 3D
+MHD convection in rotating spherical shells have demonstrated mechanisms
+whereby large-scale magnetic wreaths can be generated in the bulk of the
+convection zone. Our recent simulations have achieved sufficiently high levels
+of turbulence to permit portions of these wreaths to become magnetically
+buoyant and rise through the simulated convective layer through a combination
+of magnetic buoyancy and advection by convective giant cells. These buoyant
+magnetic loops are created in the bulk of the convective layer as strong
+Lorentz force feedback in the cores of the magnetic wreaths dampen small-scale
+convective motions, permitting the amplification of local magnetic energies to
+over 100 times the local kinetic energy. While the magnetic wreaths are largely
+generated the shearing of axisymmetric poloidal magnetic fields by axisymmetric
+rotational shear (the $\Omega$-effect), the loops are amplified to their peak
+field strengths before beginning to rise by non-axisymmetric processes. This
+further extends and enhances a new paradigm for the generation of emergent
+magnetic flux bundles, which we term turbulence-enabled magnetic buoyancy.",1401.1826v1
+2014-05-05,The magnetic shielding for the neutron decay spectrometer aSPECT,"Many experiments in nuclear and neutron physics are confronted with the
+problem that they use a superconducting magnetic spectrometer which potentially
+affects other experiments by their stray magnetic field. The retardation
+spectrometer aSPECT consists, inter alia, of a superconducting magnet system
+that produces a strong longitudinal magnetic field of up to 6.2T. In order not
+to disturb other experiments in the vicinity of aSPECT, we had to develop a
+magnetic field return yoke for the magnet system. While the return yoke must
+reduce the stray magnetic field, the internal magnetic field and its
+homogeneity should not be affected. As in many cases, the magnetic shielding
+for aSPECT must manage with limited space. In addition, we must ensure that the
+additional magnetic forces on the magnet coils are not destructive. In order to
+determine the most suitable geometry for the magnetic shielding for aSPECT, we
+simulated a variety of possible geometries and combinations of shielding
+materials of non-linear permeability. The results of our simulations were
+checked through magnetic field measurements both with Hall and nuclear magnetic
+resonance probes. The experimental data are in good agreement with the
+simulated values: The mean deviation from the simulated exterior magnetic field
+is (-1.7+/-4.8)%. However, in the two critical regions, the internal magnetic
+field deviates by 0.2% respectively <1E-4 from the simulated values.",1405.0957v1
+2014-07-15,Magnetic nanoparticle traveling in external magnetic field,"A set of equations describing the motion of a free magnetic nanoparticle in
+an external magnetic field in a vacuum, or in a medium with negligibly small
+friction forces is postulated. The conservation of the total particle momentum,
+i.e. the sum of the mechanical and the total spin momentum of the nanoparticle
+is taken into account explicitly. It is shown that for the motion of a
+nanoparticle in uniform magnetic field there are three different modes of
+precession of the unit magnetization vector and the director that is parallel
+the particle easy anisotropy axis. These modes differ significantly in the
+precession frequency. For the high-frequency mode the director points
+approximately along the external magnetic field, whereas the frequency and the
+characteristic relaxation time of the precession of the unit magnetization
+vector are close to the corresponding values for conventional ferromagnetic
+resonance. On the other hand, for the low-frequency modes the unit
+magnetization vector and the director are nearly parallel and rotate in unison
+around the external magnetic field. The characteristic relaxation time for the
+low-frequency modes is remarkably long. This means that in a rare assembly of
+magnetic nanoparticles there is a possibility of additional resonant absorption
+of the energy of alternating magnetic field at a frequency that is much smaller
+compared to conventional ferromagnetic resonance frequency. The scattering of a
+beam of magnetic nanoparticles in a vacuum in a non-uniform external magnetic
+field is also considered taking into account the precession of the unit
+magnetization vector and director.",1407.3964v1
+2018-12-30,Magnetic properties of an antiferromagnetic spin-1/2 XYZ model in the presence of different magnetic fields: finite-size effects of inhomogeneity property,"Magnetic and thermodynamic properties of the anisotropic XYZ spin-1/2 finite
+chain under both homogeneous and inhomogeneous magnetic fields are
+theoretically studied at low temperature. Using exact diagonalization method
+(ED), we study the magnetization, magnetic susceptibility and specific heat of
+the model characterized in terms of the finite correlation length in the
+presence of three different magnetic fields including longitudinal, transverse
+and transverse staggered magnetic fields. The magnetization, susceptibility and
+the specific heat of the model are investigated under two conditions
+separately: I) when the model is putted in the presence of homogeneous magnetic
+fields; II) when finite inhomogeneities are considered for all applied magnetic
+fields in the Hamiltonian. We show that for the finite-size XYZ chains at low
+temperature, the evident magnetization plateaus gradually convert to their
+counterpart quasi-plateaus when the transverse magnetic field increases.
+Moreover, the influence of the transverse and staggered transverse magnetic
+fields, and their corresponding inhomogeneities on the magnetization process,
+magnetic susceptibility, and specific heat are reported in detail. Our exact
+results illustrate that by altering the inhomogeneity parameters, magnetization
+plateaus gradually convert to their counterpart quasi-plateaus. The specific
+heat manifests Schottky-type maximum, double-peak and triple-peak, as well as,
+transformation between them by varying considered inhomogeneity parameters in
+the Hamiltonian.",1812.11468v2
+2019-04-18,Insight into the magnetic behavior of Sr$_2$IrO$_4$:A spontaneous magnetization study,"Sr$_2$IrO$_4$ is a weak ferromagnet where the spin arrangement is canted
+anti-ferromagnetic (AF). Moreover, the spin-structure coupling plays and
+important role in magnetic behavior of Sr$_2$IrO$_4$. In this concern the
+magnetization under zero applied field i.e. spontaneous magnetization would be
+interesting to study and would give insight into the novel magnetic behavior of
+Sr$_2$IrO$_4$. Sophisticated techniques like neutron diffraction, $\mu$
+\textit{SR} etc has been used to understand the magnetic behavior of
+Sr$_2$IrO$_4$ under zero applied field. To understand the magnetic behavior we
+have performed detail field and temperature dependent magnetization study, the
+measured field and temperature dependent magnetic data is analyzed rigorously.
+We have attempted the understand the temperature dependance of spontaneous
+magnetization, remanent magnetization and coercive force. We observe that the
+spontaneous magnetization extracted from Arrott plot shows that the
+Sr$_2$IrO$_4$ is not an ideal ferromagnet. The temperature dependent coercive
+field is found to follows Guant's model of strong domain wall pinning. Our
+investigation explicit the temperature dependence of various magnetic
+properties shows the magnetic transitions from paramagnetic to ferromagnetic
+phase with $T_c$ around 225 K and a low temperature evolution of magnetic
+magnetic moment around $T_M$ $\sim$90 K.",1904.08792v1
+2020-01-08,Non-equilibrium spin dynamics in the temperature and magnetic field dependence of magnetization curves of ferrimagnetic Co$_{1.75}$Fe$_{1.25}$O$_4$ and its composite with BaTiO$_3$,"A comparative study of the non-equilibrium magnetic phenomena (magnetic
+blocking, memory, exchange bias and aging effect) has been presented for
+ferrimagnetic Co$_{1.75}$Fe$_{1.25}$O$_4$ (CFO) and its composite with
+non-magnetic BaTiO$_3$ (BTO). Synchrotron X-Ray diffraction patterns have
+confirmed coexistence of CFO and BTO structures in composite, but magnetic spin
+dynamics have been remarkably modified. The blocking phenomenon of
+ferrimagnetic domains below the room temperature has been studied by different
+modes of (zero field cooled and field cooled) magnetic measurements in
+collaboration with magnetic fields ON and OFF modes and time dependent
+magnetization. The applications of unconventional protocols during time
+dependent magnetization measurement at different stages of the temperature and
+field dependence of the magnetization curves have been useful to reveal the
+non-equilibrium dynamics of magnetic spin order. The applying of off-field
+relaxation experiments has made possible to tune the magnetic state and
+coercivity of the systems. The role of interfacial coupling between magnetic
+and non-magnetic particles has been understood on different magnetic phenomena
+(meta-stable magnetic state, exchange bias and memory effect) by comparing the
+experimental results of Co$_{1.75}$Fe$_{1.25}$O$_4$ spinel oxide and its
+composite with BaTiO$_3$ particles.",2001.02602v2
+2021-09-24,Fluidic Endogenous Magnetism and Magnetic Monopole Clues from Liquid Metal Droplet Machine,"Magnetism and magnetic monopole are classical issues in basic physics.
+Conventional magnets are generally composed of rigid materials with shapes and
+structures unchangeable which may face challenges sometimes to answer the above
+questions. Here, from an alternative other than rigid magnet, we disclosed an
+unconventional way to generate endogenous magnetism and then construct magnetic
+monopole through tuning liquid metal machine. Through theoretical
+interpretation and conceptual experiments, we illustrated that when gallium
+base liquid metal in solution rotates under actuation of an external electric
+field, it forms an endogenous magnetic field inside which well explains the
+phenomenon that two such discrete metal droplets could easily fuse together,
+indicating their reciprocal attraction via N and S poles. Further, we conceived
+that the self-driving liquid metal motor was also an endogenous magnet owning
+the electromagnetic homology. When liquid metal in solution swallowed aluminum
+inside, it formed a spin motor and dynamically variable charge distribution
+which produced an endogenous magnetic field. This finding explains the
+phenomena that there often happened reflection collision and attraction fusion
+between running liquid metal motors which were just caused by the dynamic
+adjustment of their N and S polarities. Finally, we conceived that such
+endogenous magnet could lead to magnetic monopole and four technical routes
+were suggested as: 1. Matching the interior flow field of liquid metal
+machines; 2. Superposition between external electric effect and magnetic field;
+3. Composite construction between magnetic particles and liquid metal motor; 4.
+Chemical ways such as via galvanic cell reaction. Overall, the fluidic
+endogenous magnet and the promising magnetic monopole it enabled may lead to
+unconventional magnetoelectric devices and applications in the near future.",2111.02867v1
+2022-05-13,Isotropic orbital magnetic moments in magnetically anisotropic SrRuO3 films,"Epitaxially strained SrRuO3 films have been a model system for understanding
+the magnetic anisotropy in metallic oxides. In this paper, we investigate the
+anisotropy of the Ru 4d and O 2p electronic structure and magnetic properties
+using high-quality epitaxially strained (compressive and tensile) SrRuO3 films
+grown by machine-learning-assisted molecular beam epitaxy. The element-specific
+magnetic properties and the hybridization between the Ru 4d and O 2p orbitals
+were characterized by Ru M2,3-edge and O K-edge soft X-ray absorption
+spectroscopy and X-ray magnetic circular dichroism measurements. The
+magnetization curves for the Ru 4d and O 2p magnetic moments are identical,
+irrespective of the strain type, indicating the strong magnetic coupling
+between the Ru and O ions. The electronic structure and the orbital magnetic
+moment relative to the spin magnetic moment are isotropic despite the
+perpendicular and in-plane magnetic anisotropy in the compressive-strained and
+tensile-strained SrRuO3 films; i.e., the orbital magnetic moments have a
+negligibly small contribution to the magnetic anisotropy. This result
+contradicts Bruno model, where magnetic anisotropy arises from the difference
+in the orbital magnetic moment between the perpendicular and in-plane
+directions. Contributions of strain-induced electric quadrupole moments to the
+magnetic anisotropy are discussed, too.",2205.06563v1
+2023-09-21,Integrable Magnetic Fluid Hyperthermia Systems for 3D Magnetic Particle Imaging,"Background: Combining magnetic particle imaging (MPI) and magnetic fluid
+hyperthermia (MFH) offers the ability to perform localized hyperthermia and
+magnetic particle imaging-assisted ther-mometry of hyperthermia treatment. This
+allows precise regional selective heating inside the body without invasive
+interventions. In current MPI-MFH platforms, separate systems are used, which
+require object transfer from one system to another. Here, we present the
+design, development and evaluation process for integrable MFH platforms, which
+extends a commercial MPI scanner with the functionality of MFH. Methods: The
+biggest issue of integrating magnetic fluid hyperthermia platforms into a
+magnetic par-ticle imaging system is the magnetic coupling of the devices,
+which induces high voltage in the imaging system, and is harming its
+components. In this paper we use a self-compensation approach derived from
+heuristic algorithms to protect the magnetic particle imaging scanner. The
+integrable platforms are evaluated regarding electrical and magnetic
+characteristics, cooling capability, field strength, the magnetic coupling to a
+replica of the magnetic particle imaging system's main solenoid and particle
+heating. Results: The MFH platforms generate suitable magnetic fields for
+magnetic heating of particles and are compatible with a commercial magnetic
+particle imaging scanner. In combination with the imaging system, selective
+heating with a gradient field and steerable heating positioning using the MPI
+focus fields are possible. Conclusion: The proposed MFH platforms serve as a
+therapeutic tool to unlock MFH functionality of a commercial magnetic particle
+imaging scanner, enabling its use in future preclinical trials of MPI-guided,
+spatially selective magnetic hyperthermia therapy.",2309.12186v1
+2002-05-15,Magnetic Fluctuations with a Zero Mean Field in a Random Fluid Flow with a Finite Correlation Time and a Small Magnetic Diffusion,"Magnetic fluctuations with a zero mean field in a random flow with a finite
+correlation time and a small yet finite magnetic diffusion are studied.
+Equation for the second-order correlation function of a magnetic field is
+derived. This equation comprises spatial derivatives of high orders due to a
+non-local nature of magnetic field transport in a random velocity field with a
+finite correlation time. For a random Gaussian velocity field with a small
+correlation time the equation for the second-order correlation function of the
+magnetic field is a third-order partial differential equation. For this
+velocity field and a small magnetic diffusion with large magnetic Prandtl
+numbers the growth rate of the second moment of magnetic field is estimated.
+The finite correlation time of a turbulent velocity field causes an increase of
+the growth rate of magnetic fluctuations. It is demonstrated that the results
+obtained for the cases of a small yet finite magnetic diffusion and a zero
+magnetic diffusion are different. Astrophysical applications of the obtained
+results are discussed.",0205233v1
+2005-06-30,Magnetic versus nonmagnetic doping effects on the magnetic ordering in the Haldane chain compound PbNi2V2O8,"A study of an impurity driven phase-transition into a magnetically ordered
+state in the spin-liquid Haldane chain compound PbNi2V2O8 is presented. Both,
+macroscopic magnetization as well as 51V nuclear magnetic resonance (NMR)
+measurements reveal that the spin nature of dopants has a crucial role in
+determining the stability of the induced long-range magnetic order. In the case
+of nonmagnetic (Mg2+) doping on Ni2+ spin sites (S=1) a metamagnetic transition
+is observed in relatively low magnetic fields. On the other hand, the magnetic
+order in magnetically (Co2+) doped compounds survives at much higher magnetic
+fields and temperatures, which is attributed to a significant anisotropic
+impurity-host magnetic interaction. The NMR measurements confirm the predicted
+staggered nature of impurity-liberated spin degrees of freedom, which are
+responsible for the magnetic ordering. In addition, differences in the
+broadening of the NMR spectra and the increase of nuclear spin-lattice
+relaxation in doped samples, indicate a diverse nature of electron spin
+correlations in magnetically and nonmagnetically doped samples, which begin
+developing at rather high temperatures with respect to the antiferromagnetic
+phase transition.",0506808v1
+2006-09-15,Superconducting pipes and levitating magnets,"Motivated by a beautiful demonstration of the Faraday's and Lenz's law in
+which a small neodymium magnet falls slowly through a conducting
+non-ferromagnetic tube, we consider the dynamics of a magnet falling through a
+superconducting pipe. Unlike the case of normal conducting pipes, in which the
+magnet quickly reaches the terminal velocity, inside a superconducting tube the
+magnet falls freely. On the other hand, to enter the pipe the magnet must
+overcome a large electromagnetic energy barrier. For sufficiently strong
+magnets, the barrier is so large that the magnet will not be able to penetrate
+it and will be suspended over the front edge. We calculate the work that must
+done to force the magnet to enter a superconducting tube. The calculations show
+that superconducting pipes are very efficient at screening magnetic fields. For
+example, the magnetic field of a dipole at the center of a short pipe of radius
+$a$ and length $L \approx a$ decays, in the axial direction, with a
+characteristic length $\xi \approx 0.26 a$. The efficient screening of the
+magnetic field might be useful for shielding highly sensitive superconducting
+quantum interference devices, SQUIDs. Finally, the motion of the magnet through
+a superconducting pipe is compared and contrasted to the flow of ions through a
+trans-membrane channel.",0609141v1
+2007-02-18,Planar Atom Trap and Magnetic Resonance 'Lens' Designs,"We present various planar magnetic designs that create points above the plane
+where the magnitude of the static magnetic field is a local minimum. Structures
+with these properties are of interest in the disciplines of neutral atom
+confinement, magnetic levitation, and magnetic resonance imaging. Each planar
+permanent magnet design is accompanied by the equivalent planar single
+non-crossing conductor design. Presented designs fall into three categories
+producing: a) zero value magnetic field magnitude point minima, b) non-zero
+magnetic field magnitude point minima requiring external bias magnetic field,
+and c) self-biased non-zero magnetic field magnitude point minima. We also
+introduce the Principle of Amperean Current Doubling in planar perpendicularly
+magnetized thin films that can be used to improve the performance of each
+permanent magnet design we present. Single conductor current-carrying designs
+are suitable for single layer lithographic fabrication, as we experimentally
+demonstrate. Finally, we present the case that nanometer scale recording of
+perpendicular anisotropy thin magnetic films using presently available data
+storage technology can provide the ultimate miniaturization of the presented
+designs.",0702154v1
+2008-05-26,Magnetic field induced incommensurate resonance in cuprate superconductors,"The influence of a uniform external magnetic field on the dynamical spin
+response of cuprate superconductors in the superconducting state is studied
+based on the kinetic energy driven superconducting mechanism. It is shown that
+the magnetic scattering around low and intermediate energies is dramatically
+changed with a modest external magnetic field. With increasing the external
+magnetic field, although the incommensurate magnetic scattering from both low
+and high energies is rather robust, the commensurate magnetic resonance
+scattering peak is broadened. The part of the spin excitation dispersion seems
+to be an hourglass-like dispersion, which breaks down at the heavily low energy
+regime. The theory also predicts that the commensurate resonance scattering at
+zero external magnetic field is induced into the incommensurate resonance
+scattering by applying an external magnetic field large enough.",0805.3922v2
+2010-10-22,Dissipation in dynamos at low and high magnetic Prandtl numbers,"Using simulations of helically driven turbulence, it is shown that the ratio
+of kinetic to magnetic energy dissipation scales with the magnetic Prandtl
+number in power law fashion with an exponent of approximately 0.6. Over six
+orders of magnitude in the magnetic Prandtl number the magnetic field is found
+to be sustained by large-scale dynamo action of alpha-squared type. This work
+extends a similar finding for small magnetic Prandtl numbers to the regime of
+large magnetic Prandtl numbers. At large magnetic Prandtl numbers, most of the
+energy is dissipated viscously, lowering thus the amount of magnetic energy
+dissipation, which means that simulations can be performed at magnetic Reynolds
+numbers that are large compared to the usual limits imposed by a given
+resolution. This is analogous to an earlier finding that at small magnetic
+Prandtl numbers, most of the energy is dissipated resistively, lowering the
+amount of kinetic energy dissipation, so simulations can then be performed at
+much larger fluid Reynolds numbers than otherwise. The decrease in magnetic
+energy dissipation at large magnetic Prandtl numbers is discussed in the
+context of underluminous accretion found in some quasars.",1010.4805v2
+2011-07-08,Antimagnets: Controlling magnetic fields with superconductor-metamaterial hybrids,"Magnetism is very important in science and technology, from magnetic
+recording to energy generation to trapping cold atoms. Physicists have managed
+to master magnetism - to create and manipulate magnetic fields- almost at will.
+Surprisingly, there is at least one property which until now has been elusive:
+how to 'switch off' the magnetic interaction of a magnetic material with
+existing magnetic fields without modifying them. Here we introduce the
+antimagnet, a design to conceal the magnetic response of a given volume from
+its exterior, without altering the external magnetic fields, somehow analogous
+to the recent theoretical proposals for cloaking electromagnetic waves with
+metamaterials. However, different from these devices requiring extreme material
+properties, our device is feasible and needs only two kinds of available
+materials: superconductors and isotropic magnetic materials. Antimagnets may
+have applications in magnetic-based medical techniques such as MRI or in
+reducing the magnetic signature of vessels or planes.",1107.1647v1
+2012-06-29,Enhancement of critical current density in superconducting/magnetic multi-layers with slow magnetic relaxation dynamics and large magnetic susceptibility,"We propose to use superconductor-magnet multi-layer structure to achieve high
+critical current density by invoking polaronic mechanism of pinning. The
+magnetic layers should have large magnetic susceptibility to enhance the
+coupling between vortices and magnetization in magnetic layers. The relaxation
+of the magnetization should be slow. When the velocity of vortices is low, they
+are dressed by nonuniform magnetization and move as polarons. In this case, the
+viscosity of vortices proportional to the magnetic relaxation time is enhanced
+significantly. As velocity increases, the polarons dissociate and the viscosity
+drops to the usual Bardeen-Stephen one, resulting in a jump in the I-V curve.
+Experimentally the jump shows up as a depinning transition and the
+corresponding current at the jump is the depinning current. For Nb and proper
+magnet multi-layer structure, we estimate the critical current density $J_c\sim
+10^{9}\ \rm{A/m^2}$ at magnetic field $B\approx 1$ T.",1206.6929v2
+2013-03-07,Complex Magnetic Phase Diagram of a Geometrically Frustrated Sm Lattice: SmPd2Al3 case,"Magnetism in SmPd2Al3 was investigated on a single crystal by magnetometry
+and neutron diffraction. SmPd2Al3 represents a distinctive example of the Sm
+magnetism exhibiting complex magnetic behavior at low temperatures with four
+consecutive magnetic phase transitions at 3.4, 3.9, 4.3 and 12.5 K. The rich
+magnetic phase diagram of this compound reflects the specific features of the
+Sm3+ ion, namely the energy nearness of the ground-state multiplet J = 5/2 and
+the first excited multiplet J = 7/2 in conjunction with strong crystal field
+influence. Consequently, a significantly reduced Sm magnetic moment in
+comparison with the theoretical Sm3+ free-ion value is observed. Despite the
+strong neutron absorption by natural samarium and the small Sm magnetic moment
+(~ 0.2 {\mu}B) we have successfully determined the magnetic k-vector (1/3, 1/3,
+0) of the phase existing in the temperature interval 12.5 - 4.3 K. This
+observation classifies the SmPd2Al3 compound as a magnetically frustrated
+system. The complex magnetic behavior of this material is further illustrated
+by kinetic effects of the magnetization inducing rather complicated magnetic
+structure with various metastable states.",1303.1607v1
+2013-05-20,Magnetization of neutron star matter,"The magnetization of neutron star matter in magnetic fields is studied by
+employing the FSUGold interaction. It is found that the magnetic
+susceptibilities of the charged particles (proton, electron and muon) can be
+larger than that of neutron. The effects of the anomalous magnetic moments
+(AMM) of each component on the magnetic susceptibility are examined in detail.
+It is found that the proton and electron AMM affect their respective magnetic
+susceptibility evidently in strong magnetic fields. In addition, they are the
+protons instead of the electrons that contribute most significantly to the
+magnetization of the neutron star matter in a relative weak magnetic field, and
+the induced magnetic field due to the magnetization can be appear to be very
+large. Finally, the effect of the density-dependent symmetry energy on the
+magnetization is discussed.",1305.4533v1
+2014-03-11,Piezo-Voltage Manipulation of the Magnetization and Magnetic Reversal in Thin Fe Film,"We carefully investigated the in-plane magnetic reversal and corresponding
+magnetic domain structures in Fe/GaAs/piezo-transducer heterostructure using
+longitudinal magneto-optical Kerr microscopy. The coexistence of the <100>
+cubic magnetic anisotropy and uniaxial magnetic anisotropy was observed in our
+Fe thin film grown on GaAs. The induced deformation along [110] orientation can
+effectively manipulate the magnetic reversal with magnetic field applied along
+magnetic uniaxial hard [110] axes. The control of two-jump magnetization
+switching to one-jump magnetization switching during the magnetic reversal was
+achieved by piezo-voltages with magnetic field applied in [100] direction. The
+additional uniaxial anisotropy induced by piezo-voltages at -75 /75V are
+-1.400/1400 J/m3 .",1403.2469v1
+2014-09-29,Review and comparison of magnet designs for magnetic refrigeration,"One of the key issues in magnetic refrigeration is generating the magnetic
+field that the magnetocaloric material must be subjected to. The magnet
+constitutes a major part of the expense of a complete magnetic refrigeration
+system and a large effort should therefore be invested in improving the magnet
+design. A detailed analysis of the efficiency of different published permanent
+magnet designs used in magnetic refrigeration applications is presented in this
+paper. Each design is analyzed based on the generated magnetic flux density,
+the volume of the region where this flux is generated and the amount of magnet
+material used. This is done by characterizing each design by a figure of merit
+magnet design efficiency parameter, $\Lambda_\mathrm{cool}$. The designs are
+then compared and the best design found. Finally recommendations for designing
+the ideal magnet design are presented based on the analysis of the reviewed
+designs.",1409.8046v1
+2015-04-22,Magnetized stars with differential rotation and a differential toroidal field,"We have succeeded in obtaining magnetized equilibrium states with
+differential rotation and differential toroidal magnetic fields. If an internal
+toroidal field of a proto-neutron star is wound up from the initial poloidal
+magnetic field by differential rotation, the distribution of the toroidal
+magnetic field is determined by the profile of this differential rotation.
+However, the distributions of the toroidal fields in all previous magnetized
+equilibrium studies do not represent the magnetic winding by the differential
+rotation of the star. In this paper, we investigate a formulation of a
+differential toroidal magnetic field that represents the magnetic field wound
+up by differential rotation. We have developed two functional forms of
+differential toroidal fields which correspond to a v-constant and a j-constant
+field in analogy to differential rotations. As the degree of the differential
+becomes very high, the toroidal magnetic field becomes highly localized and
+concentrated near the rotational axis. Such a differential toroidal magnetic
+field would suppress the low-T/|W| instability more efficiently even if the
+total magnetic field energy is much smaller than that of a non-differential
+toroidal magnetic field.",1504.05961v2
+2016-04-01,Photoinduced Magnetic Nanoprobe Excited by Azimuthally Polarized Vector Beam,"The concept of magnetic nanoprobes (or magnetic nanoantennas) providing a
+magnetic near-field enhancement and vanishing electric field is presented and
+investigated, together with their excitation. It is established that a
+particular type of cylindrical vector beams called azimuthally electric
+polarized vector beams yield strong longitudinal magnetic field on the beam
+axis where the electric field is ideally null. These beams with an electric
+polarization vortex and cylindrical symmetry are important in generating high
+magnetic to electric field contrast, i.e., large local field admittance, and in
+allowing selective excitation of magnetic transitions in matter located on the
+beam axis. We demonstrate that azimuthally polarized vector beam excitation of
+a photoinduced magnetic nanoprobe made of a magnetically polarizable nano
+cluster leads to enhanced magnetic near field with resolution beyond
+diffraction limit. We introduce two figures of merit as magnetic field
+enhancement and local field admittance normalized to that of a plane wave that
+are useful to classify magnetic nanoprobes and their excitation. The
+performance of magnetic nanoprobe and azimuthal polarized beams is quantified
+in comparison to other illumination options and with several defect scenarios.",1604.00379v1
+2016-09-23,Chirality-driven orbital magnetic moments as a new probe for topological magnetic structures,"When electrons are driven through unconventional magnetic structures, such as
+skyrmions, they experience emergent electromagnetic fields that originate
+several Hall effects. Independently, ground state emergent magnetic fields can
+also lead to orbital magnetism, even without the spin-orbit interaction. The
+close parallel between the geometric theories of the Hall effects and of the
+orbital magnetization raises the question: does a skyrmion display topological
+orbital magnetism? Here we first address the smallest systems with nonvanishing
+emergent magnetic field, trimers, characterizing the orbital magnetic
+properties from first-principles. Armed with this understanding, we study the
+orbital magnetism of skyrmions, and demonstrate that the contribution driven by
+the emergent magnetic field is topological. This means that the topological
+contribution to the orbital moment does not change under continous deformations
+of the magnetic structure. Furthermore, we use it to propose a new experimental
+protocol for the identification of topological magnetic structures, by soft
+x-ray spectroscopy.",1609.07529v1
+2017-02-24,Angle-dependence and optimal design for magnetic bubblecade with maximum speed,"Unidirectional magnetic domain-wall motion is a key concept underlying
+next-generation application devices. Such motion has been recently demonstrated
+by applying an alternating magnetic field, resulting in the coherent
+unidirectional motion of magnetic bubbles. Here we report the optimal
+configuration of applied magnetic field for the magnetic bubblecade, the
+coherent unidirectional motion of magnetic bubbles, driven by a tilted
+alternating magnetic field. The tilted alternating magnetic field induces
+asymmetric expansion and shrinkage of the magnetic bubbles under the influence
+of the Dzyaloshinskii-Moriya interaction, resulting in continuous shift of the
+bubbles in time. By realizing the magnetic bubblecade in PtCoPt films, we find
+that the bubblecade speed is sensitive to the tilt angle with a maximum at an
+angle, which can be explained well by a simple analytical form within the
+context of the domain-wall creep theory. A simplified analytic formula for the
+angle for maximum speed is then given as a function of the amplitude of the
+alternating magnetic field. The present observation provides a practical design
+rule for memory and logic devices based on the magnetic bubblecade.",1702.07439v1
+2018-09-13,On the role of magnetic fields in star formation,"Magnetic fields are observed in star forming regions. However simulations of
+the late stages of star formation that do not include magnetic fields provide a
+good fit to the properties of young stars including the initial mass function
+(IMF) and the multiplicity. We argue here that the simulations that do include
+magnetic fields are unable to capture the correct physics, in particular the
+high value of the magnetic Prandtl number, and the low value of the magnetic
+diffusivity. The artificially high (numerical and uncontrolled) magnetic
+diffusivity leads to a large magnetic flux pervading the star forming region.
+We argue further that in reality the dynamics of high magnetic Prandtl number
+turbulence may lead to local regions of magnetic energy dissipation through
+reconnection, meaning that the regions of molecular clouds which are forming
+stars might be essentially free of magnetic fields. Thus the simulations that
+ignore magnetic fields on the scales on which the properties of stellar masses,
+stellar multiplicities and planet-forming discs are determined, may be closer
+to reality than those which include magnetic fields, but can only do so in an
+unrealistic parameter regime.",1809.04921v1
+2019-03-28,Micromagnetics of rare-earth efficient permanent magnets,"The development of permanent magnets containing less or no rare-earth
+elements is linked to profound knowledge of the coercivity mechanism.
+Prerequisites for a promising permanent magnet material are a high spontaneous
+magnetization and a sufficiently high magnetic anisotropy. In addition to the
+intrinsic magnetic properties the microstructure of the magnet plays a
+significant role in establishing coercivity. The influence of the
+microstructure on coercivity, remanence, and energy density product can be
+understood by {using} micromagnetic simulations. With advances in computer
+hardware and numerical methods, hysteresis curves of magnets can be computed
+quickly so that the simulations can readily provide guidance for the
+development of permanent magnets. The potential of rare-earth reduced and free
+permanent magnets is investigated using micromagnetic simulations. The results
+show excellent hard magnetic properties can be achieved in grain boundary
+engineered NdFeB, rare-earth magnets with a ThMn12 structure, Co-based
+nano-wires, and L10-FeNi provided that the magnet's microstructure is
+optimized.",1903.11922v1
+2020-04-24,Observation of magnetic domains in uniaxial magnets via small-angle electron diffraction and Foucault imaging,"Observation of magnetic domains is important in understanding the magnetic
+properties of magnetic materials and devices. In this study, we report that the
+magnetic domains of M-type hexaferrites with uniaxial anisotropy can be
+visualized via small-angle electron diffraction and Foucault imaging. The
+position of the diffraction pattern spots has the same period as that of
+magnetic domains in a Sc-substituted hexaferrite
+(BaFe$_{12-x-\delta}$Sc$_x$Mg$_\delta$O$_{19}$). Conversely, the spots were
+observed four times longer than the period of magnetic domains in hexaferrite
+without substitution (BaFe$_{12}$O$_{19}$), demonstrating the long-range order
+of the Bloch walls. When the specimen was tilted, the magnetic deflection
+effect, as well as the periodic spots of magnetic domains, occurred. Thus, we
+were able to visualize the magnetic domains with different magnetization
+directions and domain orientations by selecting deflection spots. The results
+indicate that the technique utilized in this study is useful in observing the
+magnetic materials with uniaxial anisotropy.",2004.11589v1
+2021-01-12,Modeling of Thermal Magnetic Fluctuations in Nanoparticle Enhanced Magnetic Resonance Detection,"We present a systematic numerical modeling investigation of magnetization
+dynamics and thermal magnetic moment fluctuations of single magnetic domain
+nanoparticles in a configuration applicable to enhancing inductive magnetic
+resonance detection signal to noise ratio (SNR). Previous proposals for
+oriented anisotropic single magnetic domain nanoparticle amplification of
+magnetic flux in MRI coil focused only on the coil pick-up voltage signal
+enhancement. Here we extend the analysis to the numerical evaluation of the SNR
+by modeling the inherent thermal magnetic noise introduced into the detection
+coil by the insertion of such anisotropic nanoparticle-filled coil core. We
+utilize the Landau-Lifshitz-Gilbert equation under the Stoner-Wohlfarth single
+magnetic domain (macrospin) assumption to simulate the magnetization dynamics
+in such nanoparticles due to AC drive field as well as thermal noise. These
+simulations are used to evaluate the nanoparticle configurations and shape
+effects on enhancing SNR. Finally, we explore the effect of narrow band
+filtering of the broadband magnetic moment thermal fluctuation noise on the
+SNR. Our results provide the impetus for relatively simple modifications to
+existing MRI systems for achieving enhanced detection SNR in scanners with
+modest polarizing magnetic fields.",2101.04649v1
+2021-04-27,Mechanism of parametric pumping of magnetization precession in a nanomagnet. Parametric mechanism of current-induced magnetization reversal,"A mechanism of current-induced magnetization reversal based on the parametric
+resonance is described. The source of the magnetization reversal is a
+current-induced magnetic field, which is applied perpendicularly to the easy
+axis of magnetic anisotropy of a ferromagnetic nanomagnet. The current-induced
+magnetic field was measured in a FeCoB nanomagnet to be 60 Gauss at a current
+density of 65 mA/um2. Two mechanisms of the magnetization reversal are
+described and calculated. The first mechanism is the reversal by a RF
+electrical current, which modulated at a frequency close to the precession
+frequency of the nanomagnet. The second mechanism is the reversal by a DC
+electrical current, in which the magneto-resistance and the current dependency
+of the induced magnetic field create a positive feedback loop, which amplifies
+a random tiny thermal fluctuation into a large magnetization precession leading
+to the magnetization reversal. The combination of the proposed mechanism with
+conventional magnetization-reversal mechanisms such as the Spin Torque and the
+Spin-Orbit Torque can improve the performance of a Magnetic Random Access
+Memory.",2104.13008v1
+2021-05-02,Magnetic textures in a hexaferrite thin film and their response to magnetic fields revealed by phase microscopy,"We investigated magnetic textures in a Sc-doped hexaferrite film by means of
+phase microscopy (PM) with a hole-free phase plate in a transmission electron
+microscope. In a zero magnetic field, the stripe-shaped magnetic domains
+coexist with magnetic bubbles. The magnetization in both magnetic domains was
+oriented perpendicular to the film and the domain walls have an in-plane
+magnetization. In the remnant state at 9.2 mT, several magnetic bubbles were
+formed with the formation of stripe-shaped magnetic domains, and the
+out-of-plane component in the stripe-shaped domains gradually appeared as the
+film thickness increased. As the film thickness increases further, the magnetic
+bubbles with clockwise or counter-clockwise spin helicities formed a triangular
+lattice. These results in the remnant state suggest that the domain wall energy
+in the magnetic bubble domains is lower in the thicker region.",2105.00396v1
+2022-04-20,Control of magnetic susceptibility of probiotic strain Lactobacillus Rhamnosus GG,"The paper investigates the increase in the natural magnetically controlled
+properties of probiotic microorganisms Lactobacillus rhamnosus GG (LGG) and
+their ability to form magnetic sensitive inclusions (MsI). The magnetic
+susceptibility of LGG was increased by modifying the nutrient medium
+composition and by cultivating the probiotic culture in a constant magnetic
+field. Therefore, this study can be useful for their further use as
+magnetically controlled vectors, since it is being extensively researched for
+the use in targeted drug delivery in cancer treatment, for the prevention of
+chemotherapy complications, etc. The results of this study indicate that
+growing microorganisms with natural magnetically-guided properties in a
+modified medium with iron chelate and in an external magnetic field leads to an
+increase in the magnetic susceptibility of LGG by 1,8 and 2,6 times,
+respectively, compared with the control. The best magnetic susceptibility was
+recorded for LGG suspensions, which were grown in a constant magnetic field and
+cultured in modified medium with iron chelate. The LGG suspension, grown both
+in a constant magnetic field and on a modified medium with iron chelate, had
+the highest magnetic susceptibility and was 4.8 times larger than the control.",2204.09338v1
+2022-09-22,Stacking and Layer dependence of magnetic properties in Ti\textsubscript{2}C and Fe\textsubscript{2}C,"Magnetic MXenes are turning out to be an important family of materials for
+exploring 2D magnetism. However, investigations into the inter-dependence of
+layer thickness, stacking patterns and magnetism in these materials, from a
+microscopic point of view, is still lacking. In this work, we have used Density
+Functional Theory (DFT) based calculations to understand the effects of layer
+thickness and stacking on the magnetic properties in two magnetic MXenes,
+Ti$_{2}$C and Fe$_{2}$C in their monolayer and bilayer forms. The ground state
+magnetic structures, magnetic moments, magnetic exchange interactions, magnetic
+transition temperatures and magnetic anisotropy energies are calculated and
+analysed using their electronic structures and standardised models. We find
+that in both systems increase in layer thickness (monolayer to bilayer) affects
+the ground state magnetic configuration which is driven by the changes in the
+magnetic exchange interactions. While the effects of stacking pattern is rather
+weak in Ti$_{2}$C, they are substantial, both qualitatively and quantitatively
+in Fe$_{2}$C. The computed results are analysed from their electronic
+structures. The results suggest that fascinating physical effects can be
+obtained in Fe$_{2}$C by tuning the layer thickness and stacking patterns,
+making it more suitable for device applications.",2209.10765v1
+2023-01-04,Magnetic light amplification by stimulated emission of radiation in subwavelength systems of a dielectric cavity and magnetic quantum emitters,"We propose a magnetic laser in a subwavelength system consisting of a
+high-refractive-index dielectric cavity and an active medium formed by magnetic
+quantum emitters. Stimulated emissions of magnetic quantum emitters induced by
+their coherent interactions with quantized magnetic fields of a cavity are
+theoretically considered. The condition to archive such a magnetic laser is
+obtained. Numerical results show that magnetic lasers are feasible in some
+realistic systems, for example, a silicon disk of high-quality whispering
+gallery modes with embedded emitters. Furthermore, the competitions between the
+electric interaction and magnetic one in terms of their Purcell factors are
+also considered in some magnetic laser achievable systems. In a
+wavelength-scale silicon block of a high-order magnetic mode, the ratio of
+magnetic Purcell factor to the electric one can reach more than ~10^3 large.
+Our results open up ways to enhanced magnetic light-matter interactions.",2301.01418v2
+2023-04-23,Magnetism and Fermiology of Kagome Magnet YMn6Sn4Ge2,"Kagome lattice magnets are an interesting class of materials as they can host
+topological properties in their magnetic and electronic structures. YMn6Sn6 is
+one such compound in which a series of competing magnetic phases is stabilized
+by an applied magnetic field, and both an enigmatic topological Hall effect and
+a Dirac crossing close to the Fermi energy have been realized. This material
+also shows a magnetization-induced Lifshitz transition and evidence of a unique
+charge spin coupling in one of the magnetic phases, namely the fan-like phase.
+Tuning the magnetism, and thus the interplay with the electronic states, opens
+new avenues for precise control of these novel properties. Here, we demonstrate
+the extreme sensitivity of the magnetic phases in YMn6Sn4Ge2 through the
+investigation of structural, magnetic, and transport properties. The high
+sensitivity to small doping provides great potential for engineering the
+magnetic phases and associated electronic properties in this family of
+rare-earth kagome magnets.",2304.11502v1
+2023-06-02,Accelerating the electronic-structure calculation of magnetic systems by equivariant neural networks,"Complex spin-spin interactions in magnets can often lead to magnetic
+superlattices with complex local magnetic arrangements, and many of the
+magnetic superlattices have been found to possess non-trivial topological
+electronic properties. Due to the huge size and complex magnetic moment
+arrangement of the magnetic superlattices, it is a great challenge to perform a
+direct DFT calculation on them. In this work, an equivariant deep learning
+framework is designed to accelerate the electronic calculation of magnetic
+systems by exploiting both the equivariant constraints of the magnetic
+Hamiltonian matrix and the physical rules of spin-spin interactions. This
+framework can bypass the costly self-consistent iterations and build a direct
+mapping from a magnetic configuration to the ab initio Hamiltonian matrix.
+After training on the magnets with random magnetic configurations, our model
+achieved high accuracy on the test structures outside the training set, such as
+spin spiral and non-collinear antiferromagnetic configurations. The trained
+model is also used to predict the energy bands of a skyrmion configuration of
+NiBrI containing thousands of atoms, showing the high efficiency of our model
+on large magnetic superlattices.",2306.01558v1
+2023-08-10,Change ratios of magnetic helicity and magnetic free energy during major solar flares,"Magnetic helicity is an important concept in solar physics, with a number of
+theoretical statements pointing out the important role of magnetic helicity in
+solar flares and coronal mass ejections (CMEs). Here we construct a sample of
+47 solar flares, which contains 18 no-CME-associated confined flares and 29
+CME-associated eruptive flares. We calculate the change ratios of magnetic
+helicity and magnetic free energy before and after these 47 flares. Our
+calculations show that the change ratios of magnetic helicity and magnetic free
+energy show distinct different distributions in confined flares and eruptive
+flares. The median value of the change ratios of magnetic helicity in confined
+flares is $-0.8$%, while this number is $-14.5$% for eruptive flares. For the
+magnetic free energy, the median value of the change ratios is $-4.3$% for
+confined flares, whereas this number is $-14.6$% for eruptive flares. This
+statistical result, using observational data, is well consistent with the
+theoretical understandings that magnetic helicity is approximately conserved in
+the magnetic reconnection, as shown by confined flares, and the CMEs take away
+magnetic helicity from the corona, as shown by eruptive flares.",2308.05366v1
+2002-04-09,Local Circumstellar Magnetic Fields Around Evolved Stars,"I argue that the presence of magnetic fields around evolved stars, e.g.,
+asymptotic giant branch stars, and in PNe, does not necessarily imply that the
+magnetic field plays a global dynamical role in shaping the circumstellar
+envelope. Instead, I favor magnetic fields with small coherence lengths, which
+result from stellar magnetic spots or from jets blown by an accreting
+companion. Although the magnetic field does not play a global role in shaping
+the circumstellar envelope, it may enhance local motion (turbulent) via
+magnetic tension and reconnection. The locally strong magnetic tension may
+enforce coherence flow which may favor the masing process.",0204157v1
+1998-02-25,Magnetization Controlled Superconductivity in a Film with Magnetic Dots,"We consider a superconducting film with Magnetic Dots Array (MDA) placed on
+it. Magnetic moments of these dots are supposed to be normal to the film and
+strong enough to create vortices in the superconducting film. Magnetic
+interaction between dots is negligible. Below the superconducting transition
+temperature of the film in zero magnetic field the MDA with randomly magnetized
+dots produces resistive state of the film. Paradoxically, in a finite magnetic
+field the film with MDA is superconductive.",9802276v1
+1999-05-21,Magnetic Field Induced Ordering in Quasi-One-Dimensional Quantum Magnets,"Three-dimensional magnetic ordering transitions are studied theoretically in
+strongly anisotropic quantum magnets. An external magnetic field can drive
+quasi-one-dimensional subsystems with a spin gap into a gapless regime, thus
+inducing long-range three-dimensional magnetic ordering due to weak residual
+magnetic coupling between the subsystems. Compounds with higher spin degrees of
+freedom, such as N-leg spin-1/2 ladders, are shown to have cascades of ordering
+transitions. At high magnetic fields, zero-point fluctuations within the
+quasi-1D subsystems are suppressed, causing quantum corrections to the ordering
+temperature to be reduced.",9905331v1
+2000-04-05,Spin 1/2 Magnetic Impurity in a 2D Magnetic System Close to Quantum Critical Point,"We consider a magnetic impurity in a spin liquid state of a magnetic system
+which is close to the quantum phase transition to the magnetically ordered
+state. There is similarity between this problem and the Kondo problem. We
+derive the impurity Green's function, consider renormalizations of the magnetic
+moments of the impurity, calculate critical indexes for the magnetic
+susceptibilities and finally consider specific heat and magnetic interaction of
+two impurities.",0004057v1
+2000-04-14,Magnetic Field Effects on Neutron Diffraction in the Antiferromagnetic Phase of $UPt_3$,"We discuss possible magnetic structures in UPt$_3$ based on our analysis of
+elastic neutron-scattering experiments in high magnetic fields at temperatures
+$T<T_N$. The existing experimental data can be explained by a single-{\bf q}
+antiferromagnetic structure with three independent domains. For modest in-plane
+spin-orbit interactions, the Zeeman coupling between the antiferromagnetic
+order parameter and the magnetic field induces a rotation of the magnetic
+moments, but not an adjustment of the propagation vector of the magnetic order.
+A triple-{\bf q} magnetic structure is also consistent with neutron
+experiments, but in general leads to a non-uniform magnetization in the
+crystal. New experiments could decide between these structures.",0004253v1
+2003-07-08,Asymmetric Lineshape due to Inhomogeneous Broadening of the Crystal-Field Transitions in Mn12ac Single Crystals,"The lineshape of crystal-field transitions in single crystals of Mn12ac
+molecular magnets is determined by the magnetic history. The absorption lines
+are symmetric and Gaussian for the non-magnetized state obtained by zero-field
+cooling (zfc). In the magnetized state which is reached when the sample is
+cooled in a magnetic field (fc), however, they are asymmetric even in the
+absence of an external magnetic field. These observations are quantitatively
+explained by inhomogeneous symmetrical (Gaussian) broadening of the
+crystal-field transitions combined with a contribution of off-diagonal
+components of the magnetic susceptibility to the effective magnetic
+permeability.",0307164v1
+2005-01-17,Frustration effects in magnetic molecules,"By means of exact diagonalization we study the ground-state and the
+low-temperature physics of the Heisenberg antiferromagnet on the cuboctahedron
+and the icosidodecahedron. Both are frustrated magnetic polytopes and
+correspond to the arrangement of magnetic atoms in the magnetic molecules
+Cu12La8 and Mo72Fe30. The interplay of strong quantum fluctuations and
+frustration influences the ground state spin correlations drastically and leads
+to an interesting magnetization process at low temperatures. Furthermore the
+frustration yields low-lying non-magnetic excitations resulting in an extra
+low-temperature peak in the specific heat.",0501376v1
+2005-09-28,About low field memory and negative magnetization in semiconductors and polymers,"Ginzburg-Landau bulk magnetization of itinerant electrons can provide a
+negative effective field in the Weiss model by coupling to localized magnetic
+moments. The coupling enforces remnant magnetization, which can be negative or
+positive depending on the sample magnetic history. Stable magnetic
+susceptibility of coupled nonequilibrium subsystems with magnetization reversal
+is always positive. Gauss-scale fields could be expected for switching between
+negative and positive remnant moments in semiconductors with coupling at
+ambient temperatures. Negative magnetization in ultra-high conducting polymers
+is also discussed within the developed framework.",0509712v1
+2005-10-10,Magnetic dipole-vortex interaction in a bilayer superconductor/soft-magnet heterostructure,"We study the penetration of the nonuniform magnetic field, created by a
+magnetic dipole with out-of-plane magnetization, into a film heterostructure
+composed of a type-II superconductor layer and a soft-magnet layer. In the
+framework of the London approach, the energy of the magnetic dipole-vortex
+interaction is derived and the critical value of the dipole moment for the
+first appearance of a vortex in the superconducting constituent is found for
+two cases of the layer ordering, namely when the dipole is located near the
+superconducting or, respectively, the magnetic constituent.",0510251v1
+2005-10-18,Local field of magnetic islands: role of their shape,"I analyze in details distribution of local magnetic field induced by micro-
+and nano-magnets. I consider three kinds of elongated magnetic islands:
+ellipse-, diamond- and rectangular shaped islands which were magnetized
+uniformly along long axis. This report concentrates on the role of their shape
+upon distribution of the field. Calculations show that unlike
+rectangular-shaped magnet, ellipse-shaped and diamond-shaped ones produce much
+more localized field in proximity of its magnetic poles. Additionally in the
+case of ellipse-shaped islands the magnitude of induced field is large. This
+two facts favor arrays of ellipse-shaped magnetic islands to build
+zero-dimensional spin traps in a hybrid based on Ferromagnet/Semiconductor
+structure.",0510486v1
+2005-11-23,Nonequilibrium Magnetization of a Two-Dimensional Electron Gas in a Static Magnetic Field,"Using a sensitive DC torque magnetometer we measure the orbital magnetization
+by sweeping the density at fixed magnetic fields on GaAs-AlGaAs
+heterostructures. At low temperatures strong nonequilibrium magnetization
+signals dominate the data. In literature the observation of nonequilibrium
+signals are often associated with eddy currents generated by sweeping the
+magnetic field. The elimination of a changing magnetic field then poses a
+question regarding the origin of these signals. Our data suggests another
+source of nonequilibrium magnetization potentially due to the change of area
+occupied by compressible and incompressible states as one sweeps the Fermi
+energy from one Landau level to the next.",0511569v1
+2006-04-01,Magnetization reversal through synchronization with a microwave,"Based on the Landau-Lifshitz-Gilbert equation, it can be shown that a
+circularly-polarized microwave can reverse the magnetization of a Stoner
+particle through synchronization. In comparison with magnetization reversal
+induced by a static magnetic field, it can be shown that when a proper
+microwave frequency is used the minimal switching field is much smaller than
+that of precessional magnetization reversal. A microwave needs only to overcome
+the energy dissipation of a Stoner particle in order to reverse magnetization
+unlike the conventional method with a static magnetic field where the switching
+field must be of the order of magnetic anisotropy.",0604013v1
+2006-05-01,Possible magnetic-field-induced voltage and thermopower in diluted magnetic semiconductors,"In diluted magnetic semiconductors, the carrier concentration and the
+magnetization of local moments are strongly coupled, since the magnetic
+interaction is mediated by the carriers. It is predicted that this coupling
+leads to an electric polarization due to an applied magnetic-field gradient and
+to the appearance of a magnetic-field-dependent voltage. An expression for this
+voltage is derived within Landau theory and its magnitude is estimated for
+(Ga,Mn)As. Furthermore, a large contribution to the thermopower based on the
+same mechanism is predicted. The role of fluctuations is also discussed. These
+predictions hold both if the magnetization is uniform and if it shows
+stripe-like modulations, which are possible at lower temperatures.",0605043v1
+2006-05-22,Kondo-transport spectroscopy of single molecule magnets,"We demonstrate that in a single molecule magnet (SMM) strongly coupled to
+electrodes the Kondo effect involves all magnetic excitations. This Kondo
+effect is induced by the quantum tunneling of the magnetic moment (QTM).
+Importantly, the Kondo temperature $T_K$ can be much larger than the magnetic
+splittings. We find a strong modulation of the Kondo effect as function of the
+transverse anisotropy parameter or a longitudinal magnetic field. For both
+integer and half-integer spin this can be used for an accurate transport
+spectroscopy of the magnetic states in low magnetic fields on the order of the
+easy-axis anisotropy parameter. We set up a relationship between the Kondo
+effects for successive integer and half-integer spins.",0605514v1
+2006-07-19,Magnetic-Field Induced Gap in One-Dimensional Antiferromagnet KCuGaF$_6$,"Magnetic susceptibility and specific heat measurements in magnetic fields
+were performed on an $S=1/2$ one-dimensional antiferromagnet KCuGaF$_6$.
+Exchange interaction was evaluated as $J/k_{\rm B}\simeq 100$ K. However, no
+magnetic ordering was observed down to 0.46 K. It was found that an applied
+magnetic field induces a staggered magnetic susceptibility obeying the Curie
+law and an excitation gap, both of which should be attributed to the
+antisymmetric interaction of the Dzyaloshinsky-Moriya type and/or the staggered
+$g$-tensor. With increasing magnetic field $H$, the gap increases almost in
+proportion to $H^{2/3}$.",0607469v1
+1998-11-18,Magnetic field profiling for selected-states magnetic-resonance spectroscopy (SSMRS) and Stern-Gerlach spectroscopy (MGRS) in condensed matter,"A method was presented of profiling the magnetic field, with a zero vector of
+magnetic flux density $B_{r}$ and strong gradient G, enabling conditions for
+the Stern-Gerlach spectroscopy to be accomplished in condensed matter (the
+method has been called magnetic field gradient spectroscopy - MGRS), as well
+the previously proposed magnetic resonance spectroscopy for selected energy
+states (SSMRS). Magnetic field distribution in a model electromagnet were shown
+when condition $B_{r}= 0$ for resultant magnetic field was satisfied within the
+sample",9811034v1
+2007-08-22,Neutron channelling in a magnetic tube trap,Neutron channelling in a magnetic tube trap is discussed,0708.3042v1
+2007-11-13,Magnetic nanowires as permanent magnet materials,"We present the fabrication of metallic magnetic nanowires using a low
+temperature chemical process. We show that pressed powders and magnetically
+oriented samples exhibit a very high coercivity (6.5 kOe at 140 K and 4.8 kOe
+at 300 K). We discuss the magnetic properties of these metamaterials and show
+that they have the suitable properties to realize ""high temperature magnets""
+competitive with AlNiCo or SmCo permanent magnets. They could also be used as
+recording media for high density magnetic recording.",0711.1978v1
+2008-06-28,Effect of magnetization and magnetic field variation on stationary axisymmetric equilibrium,"The inclusion of plasma magnetization in the equations of stationary
+equilibrium is derived, and its effect on the determination of axisymmetric
+equilibrium calculated. A factor of 2 on the pressure gradient arises in the
+equilibrium equation from the force felt by the dipole moment density. The
+algebraic and differential equation formulations are compared both with and
+without consideration of magnetization, revealing the effects of both
+magnetization and magnetic field variation on the equilibrium, which become
+more pronounced for high pressures in a weak external field. The equivalence of
+the magnetized equilibrium equation with the standard equilibrium equation in
+the limit of vanishing magnetization is demonstrated.",0806.4696v2
+2008-10-07,Multiple magnetic barriers in graphene,"We study the behavior of charge carriers in graphene in inhomogeneous
+perpendicular magnetic fields. We consider two types of one-dimensional
+magnetic profiles, uniform in one direction: a sequence of N magnetic barriers,
+and a sequence of alternating magnetic barriers and wells. In both cases, we
+compute the transmission coefficient of the magnetic structure by means of the
+transfer matrix formalism, and the associated conductance. In the first case
+the structure becomes increasingly transparent upon increasing N at fixed total
+magnetic flux. In the second case we find strong wave-vector filtering and
+resonant effects. We also calculate the band structure of a periodic magnetic
+superlattice, and find a wave-vector-dependent gap around zero-energy.",0810.1236v1
+2008-12-10,Magnetic monopole and the nature of the static magnetic field,"We investigate the factuality of the hypothetical magnetic monopole and the
+nature of the static magnetic field. It is shown from many aspects that the
+concept of the massive magnetic monopoles clearly is physically untrue. We
+argue that the static magnetic field of a bar magnet, in fact, is the static
+electric field of the periodically quasi-one-dimensional electric-dipole
+superlattice, which can be well established in some transition metals with the
+localized d-electron. This research may shed light on the perfect unification
+of magnetic and electrical phenomena.",0812.2048v1
+2011-07-14,Magnetic instability induced by tunnel current in single Co nanoparticles,"Measurements of magnetic hysteresis loops in single Co nanoparticles at
+dilution refrigerator temperatures are presented. The nanoparticles are in
+electric contact with bulk Al leads via tunnel junctions. The tunnel current
+versus magnetic field displays a magnetic hysteresis loop. The magnetic
+switching field is reduced by current, and the magnetization of the
+nanoparticle can be switched by applying a voltage pulse, demonstrating that
+the magnetic stability of the nanoparticle is diminished by electron transport.
+Additional transitions and random switches of magnetization can be driven by
+large currents.",1107.2850v3
+2011-08-09,"Magnetic phases of a highly frustrated magnet, ZnCr2O4, up to an ultra-high magnetic field of 600 T","The Faraday rotation and magneto-optical absorption spectral measurements
+were conducted to reveal the full-magnetization process and map out a magnetic
+phase diagram of a typical geometrical frustrated magnet, ZnCr2O4, by using the
+electromagnetic flux compression method in ultra-magnetic fields up to 600 T. A
+fully polarized ferromagnetic phase is observed in which the absorption spectra
+associated with an exciton-magnon-phonon transition disappears. Furthermore,
+prior to the fully polarized ferromagnetic phase above 410 T, we found a novel
+magnetic phase above 350 T followed by a canted 3:1 phase.",1108.1932v1
+2012-01-04,Origin of training effect of exchange bias in Co/CoO due to irreversible thermoremanent magnetization of the magnetically diluted antiferromagnet,"The irreversible thermoremanent magnetization of a sole, magnetically diluted
+epitaxial antiferromagnetic Co$_{1-y}$O(100) layer is determined by the mean of
+its thermoremanent magnetizations at positive and negative remanence. During
+hysteresis-loop field cycling, thermoremanent magnetization exhibits successive
+reductions, consistent with the training effect (TE) of the exchange bias
+measured for the corresponding Co$_{1-y}$O(100)/Co bilayer. The TE of exchange
+bias is shown to have its microscopic origin in the TE of the irreversible
+thermoremanent magnetization of the magnetically diluted AFM.",1201.0831v1
+2012-03-21,Percolation and orientational ordering in systems of magnetic nanorods,"Based on Monte Carlo (MC) computer simulations we study the structure
+formation of a system of magnetic nanorods. Our model particles consist of
+fused spheres with permanent magnetic dipole moments, as inspired by recent
+experiments. The resulting system behaves significantly different from a system
+of hard (non-magnetic) rods or magnetic rods with a single longitudinal dipole.
+In particular, we observe for the magnetic nanorods a significant decrease of
+the percolation threshold (as compared to non-magnetic rods) at low densities,
+and a stabilization of the high-density nematic phase. Moreover, the
+percolation threshold is tunable by an external magnetic field.",1203.4707v1
+2012-07-10,Micromagnetic simulation of magnetic small-angle neutron scattering from two-phase nanocomposites,"The recent development of a micromagnetic simulation methodology - suitable
+for multiphase magnetic nanocomposites - permits the computation of the
+magnetic microstructure and of the associated magnetic small-angle neutron
+scattering (SANS) cross section of these materials. In this review article we
+summarize results on the micromagnetic simulation of magnetic SANS from
+two-phase nanocomposites. The decisive advantage of this approach resides in
+the possibility to srutinize the individual magnetization Fourier contributions
+to the total magnetic SANS cross section, rather than their sum, which is
+generally obtained from experiment. The procedure furnishes unique and
+fundamental information regarding magnetic neutron scattering from nanomagnets.",1207.2331v1
+2013-04-10,A proposed new route to d0 magnetism in semiconductors,"Here we propose to induce magnetism in semiconductor utilizing the unique
+properties of the interstitial defect to act as the magnetic impurity within
+the alpha-PbO crystal structure. The Pbi interstitial generates the p-localized
+state with two on-site electrons to obey the Hund's rule for their ordering. It
+is demonstrated that instead of Pb interstitial other non-magnetic impurities
+of s^2p^{x} outer shell configuration can be applied to induce d0 magnetism
+with possibility to tune the local magnetic moments mu_B by varying a number of
+electrons 1< x< 3. The magnetic coupling between such defects is found to be
+driven by the long-range order interactions that in combination with high
+defect solubility promises the magnetic percolation to remain above the room
+temperature.",1304.2945v1
+2013-11-21,A new Approach for Magnetic Curves in 3D Riemannian Manifolds,"A magnetic field is defined by the property that its divergence is zero in a
+three dimensional oriented Riemannian manifold. Each magnetic field generates a
+magnetic flow whose trajectories are curves called as magnetic curves. In this
+paper, we give a new variational approach to studies the magnetic flow
+asociated with the Killing magnetic field in a three dimensional oriented
+Riemann manifold, And then, we investigate the trajectories of the magnetic
+fields called as N-magnetic and B-magnetic curves.",1311.5348v3
+2014-03-13,Monte Carlo simulated dynamical magnetization of single-chain magnets,"Here, a dynamical Monte-Carlo (DMC) method is used to study
+temperature-dependent dynamical magnetization of famous Mn2Ni system as typical
+example of single-chain magnets with strong magnetic anisotropy. Simulated
+magnetization curves are in good agreement with experimental results under
+typical temperatures and sweeping rates, and simulated coercive fields as
+functions of temperature are also consistent with experimental curves. Further
+analysis indicates that the magnetization reversal is determined by both
+thermal-activated effects and quantum spin tunnelings. These can help explore
+basic properties and applications of such important magnetic systems.",1403.3188v2
+2014-09-25,Atomistic simulation of sub-nanosecond non-equilibrium field cooling processes for magnetic data storage applications,"Thermally assisted magnetic writing is an important technology utilizing
+temperature dependent magnetic properties to enable orientation of a magnetic
+data storage medium. Using an atomistic spin model we study non-equilibrium
+field cooled magnetization processes on sub-nanosecond timescales required for
+device applications. We encapsulate the essential physics of the process in a
+TRM-T curve and show that for fast timescales heating to the Curie temperature
+is necessary where the magnetic relaxation time is shortest. Furthermore we
+demonstrate the requirement for large magnetic fields to achieve a high
+thermoremanent magnetization necessary for fast recording or data rates.",1409.7377v1
+2015-05-13,Optical detection of magnetic orders in HgCr$_2$O$_4$ frustrated spin magnet under pulsed high magnetic fields,"A magneto-optical survey was conducted for HgCr$_2$O$_4$ powder samples under
+pulsed high magnetic fields of up to 55 T. Intensity changes in magnetic fields
+observed for the exciton-magnon-phonon optical transition spectra coincide well
+with those of magnetization, lattice distortion from X-ray diffraction, and
+electron-magnetic resonances. The last-ordered phase was detected prior to the
+fully polarized magnetic phase, similarly to the other chromium spinel oxide,
+ZnCr$_2$O$_4$ and CdCr$_2$O$_4$.",1505.03216v1
+2015-07-22,Magnetic Response Functions in Landau Levels,"We propose a new quantization rule which generates Landau levels consistent
+with the zero-field magnetic response functions from the semiclassical theory.
+It reproduces the Onsager's rule in the leading order, and re-formulates
+corrections from the Berry phase and magnetic moment effect in terms of one
+single magnetic response: the zero-field magnetization. It can yield higher
+order corrections by including successively magnetic susceptibility and higher
+order magnetic response functions. In application, it can be easily applied to
+obtain Landau levels in lattice models. Moreover, it provides an experimental
+method of measuring different magnetic response functions directly from the
+measurement of Landau level fan diagram or Hofstadter spectrum.",1507.06342v2
+2016-02-29,Gyrotropic skyrmion modes in ultrathin magnetic circular dots,"We calculate low-frequency gyrotropic spin excitation modes of the skyrmion
+ground state ultrathin cylindrical magnetic dots. The skyrmion is assumed to be
+stabilized at room temperature and zero external magnetic field due to an
+interplay of the isotropic and Dzyaloshinskii-Moriya exchange interactions,
+perpendicular magnetic anisotropy and magnetostatic interaction. We consider
+Bloch- and Neel-type magnetic skyrmions and assume that the dot magnetization
+does not depend on the thickness coordinate. The skyrmion gyrotropic
+frequencies are calculated in GHz range as a function of the skyrmion
+equilibrium radius, dot radius and the dot magnetic parameters. Recent
+experiments on magnetic skyrmion gyrotropic dynamics in nanodots are discussed.",1603.00072v1
+2016-04-05,Incommensurate Magnetic Structure in the Cubic Noncentrosymmetric Ternary Compound Pr5Ru3Al2,"We performed magnetic susceptibility and neutron powder diffraction
+experiments on the ternary compound Pr5Ru3Al2. It belongs to the
+noncentrosymmetric and nonmirrorsymmetric cubic I213 space group. The
+previously reported ferromagnetic transition at 24 K was not detected in our
+improved quality samples. Instead, magnetic ordering was observed in the DC
+magnetic susceptibility at 3.8 K. Neutron powder diffraction further indicates
+that an incommensurate magnetic structure is established below 3.8 K, with the
+magnetic modulation vector (0.066, 0.066, 0.066) (r.l.u.). Using the magnetic
+representation analysis, we propose the block helical structure as a candidate
+for the incommensurate magnetic structure.",1604.01149v1
+2016-06-08,Magnetic energy of sc ferromagnetic films with three layers as described by third order perturbed Heisenberg Hamiltonian,"The solution of third order perturbed Heisenberg Hamiltonian of simple cubic
+ferromagnetic ultra-thin films with three layers were found. All the magnetic
+energy parameters such as spin exchange interaction, magnetic dipole
+interaction, second order magnetic anisotropy, fourth order magnetic
+anisotropy, applied magnetic field, demagnetization factor and stress induced
+anisotropy were included in the third order perturbed Heisenberg Hamiltonian.
+3-D plots of stress induced anisotropy, out of plane magnetic field,
+demagnetization factor and spin exchange interaction are presented in this
+manuscript. Magnetic easy and hard directions were determined using these 3-D
+plots. MATLAB program was employed to solve the equation with seven parameters.",1606.02439v1
+2016-07-19,MHD flow and heat transfer due to the axisymmetric stretching of a sheet with induced magnetic field,"The full MHD equations, governing the flow due to the axisymmetric stretching
+of a sheet in the presence of a transverse magnetic field, can be cast in a
+self similar form. This allows evaluation of the induced magnetic field and its
+effect on the flow and heat transfer. The problem involves three parameters-
+the magnetic Prandtl number, the magnetic interaction number, and the Prandtl
+number. Numerical solutions are obtained for the velocity field, the magnetic
+field, and the temperature, at different values of the magnetic Prandtl number
+and the magnetic interaction number. The contributions of the viscous
+dissipation, Joule heating, and streamwise diffusion to the heat flux toward
+the sheet are assessed.",1607.05722v1
+2017-02-27,Magnetization reversal by superconducting current in $\varphi_0$ Josephson junctions,"We study magnetization reversal in a $\varphi_0$ Josephson junction with
+direct coupling between magnetic moment and Josephson current. Our simulations
+of magnetic moment dynamics show that by applying an electric current pulse, we
+can realize the full magnetization reversal. We propose different protocols of
+full magnetization reversal based on the variation of the Josephson junction
+and pulse parameters, particularly, electric current pulse amplitude, damping
+of magnetization and spin-orbit interaction. We discuss experiments which can
+probe the magnetization reversal in $\varphi_0$-junctions.",1702.08394v4
+2017-05-16,An approach to 1000 T using the Electro-Magnetic Flux Compression,"An ultra-high magnetic field was generated by the electro-magnetic flux
+compression technique under a reduced seed magnetic field condition and
+achieved maximum magnetic field intensity was investigated. An ordinal pickup
+coil measurement fails due to the dielectric breakdown at around 500 T. On the
+other hand, by utilizing the magneto-optical Faraday rotation method with a
+small probe, the measureable maximum magnetic field increased significantly. It
+was found that reduced seed field increases the maximum magnetic field, but
+with a reduced size of the final bore. A highest magnetic field over 763 T and
+possibly up to 985 T approaching 1000 T was detected.",1705.05520v1
+2018-01-09,Magneto-electric effect in doped magnetic ferroelectrics,"We propose a model of magneto-electric effect in doped magnetic
+ferroelectrics. This magneto-electric effect does not involve the spin-orbit
+coupling and is based purely on the Coulomb interaction. We calculate magnetic
+phase diagram of doped magnetic ferroelectrics. We show that magneto-electric
+coupling is pronounced only for ferroelectrics with low dielectric constant. We
+find that magneto-electric coupling leads to modification of magnetization
+temperature dependence in the vicinity of ferroelectric phase transition. A
+peak of magnetization appears. We find that magnetization of doped magnetic
+ferroelectrics strongly depends on applied electric field.",1801.03114v1
+2018-03-03,Long Range Magnetic order stabilized by acceptors,"Tuning magnetic order in magnetic semiconductors is a long sought goal. A
+proper concentration of acceptors can dramatically suppress local magnetic
+order in favor of the long one. Using Mn and an acceptor codoped LiZnAs as an
+example, we demonstrate, by first-principles calculation, the emergence of a
+long-range magnetic order. This intriguing phenomenon can be understood from an
+interplay between an acceptor-free magnetism and a band coupling magnetism. Our
+observation thus lays the ground for a precise control of the magnetic order in
+future spintronic devices.",1803.01179v1
+2018-05-24,Searching the weakest link: Demagnetizing fields and magnetization reversal in permanent magnets,"Magnetization reversal in permanent magnets occurs by the nucleation and
+expansion of reversed domains. Micromagnetic theory offers the possibility to
+localize the spots within the complex structure of the magnet where
+magnetization reversal starts. We compute maps of the local nucleation field in
+a Nd2Fe14B permanent magnet using a model order reduction approach. Considering
+thermal fluctuations in numerical micromagnetics we can also quantify the
+reduction of the coercive field due to thermal activation. However, the major
+reduction of the coercive field is caused by the soft magnetic grain boundary
+phases and misorientation if there is no surface damage.",1805.09798v1
+2019-06-04,Deterministic magnetization switching by voltage-control of magnetic anisotropy and Dzyaloshinskii-Moriya interaction under in-plane magnetic field,"Based on the micromagnetic simulations the magnetization switching in a
+triangle magnetic element by voltage-control of magnetic anisotropy and
+Dzyaloshinskii-Moriya interaction under in-plane magnetic field is proposed.
+The proposed switching scheme is not the toggle switching but the deterministic
+switching where the magnetic state is determined by the polarity of the applied
+voltage pulse. The mechanism and conditions for the switching are clarified.
+The results provide a fast and low-power writing method for magnetoresistive
+random access memories.",1906.01254v1
+2019-06-14,Friedel oscillations in 2D electron gas from spin-orbit interaction in a parallel magnetic field,"Effects associated with the interference of electron waves around a magnetic
+point defect in two-dimensional electron gas with combined Rashba-Dresselhaus
+spin-orbit interaction in the presence of a parallel magnetic field are
+theoretically investigated. The effect of a magnetic field on the anisotropic
+spatial distribution of the local density of states and the local density of
+magnetization is analyzed. The existence of oscillations of the density of
+magnetization with scattering by a non-magnetic defect and the contribution of
+magnetic scattering (accompanied by spin-flip) in the local density of electron
+states are predicted.",1906.06043v1
+2019-06-21,Magnetic lattices for ultracold atoms,"This article reviews the development in our laboratory of magnetic lattices
+comprising periodic arrays of magnetic microtraps created by patterned magnetic
+films to trap periodic arrays of ultracold atoms. Recent achievements include
+the realisation of multiple Bose-Einstein condensates in a 10 micron-period
+one-dimensional magnetic lattice; the fabrication of sub-micron-period square
+and triangular magnetic lattice structures suitable for quantum tunnelling
+experiments; the trapping of ultracold atoms in a sub-micron-period triangular
+magnetic lattice; and a proposal to use long-range interacting Rydberg atoms to
+achieve spin-spin interactions between sites in a large-spacing magnetic
+lattice.",1906.08918v1
+2020-08-26,A Magnetic Velocity Verlet Method,"We discuss an extension of the velocity Verlet method that accurately
+approximates the kinetic-energy-conserving charged particle motion that comes
+from magnetic forcing. For a uniform magnetic field, the method is shown to
+conserve both particle kinetic energy and magnetic dipole moment better than
+midpoint Runge-Kutta. We then use the magnetic velocity Verlet method to
+generate trapped particle trajectories, both in a cylindrical magnetic mirror
+machine setup, and for dipolar fields like the earth's magnetic field. Finally,
+the method is used to compute an example of (single) mirror motion in the
+presence of a magnetic monopole field, where the trajectory can be described in
+closed form.",2008.11810v1
+2021-02-26,Distinctive magnetic properties of CrI3 and CrBr3 monolayers caused by spin-orbit coupling,"After the discovery of magnetism in monolayer CrI3, the magnetic properties
+of different 2D materials from the chromium-trihalide family are intuitively
+assumed to be similar, yielding magnetic anisotropy from the spin-orbit
+coupling on halide ligands. Here we reveal significant differences between the
+CrI3 and CrBr3 magnetic monolayers in their magnetic anisotropy, resulting
+Curie temperature, hysteresis in external magnetic field, and evolution of
+magnetism with strain, all predominantly attributed to distinctly different
+interplay of atomic contributions to spin-orbit coupling in two materials.",2102.13325v1
+2021-06-01,Impact of magnetic domains on magnetic flux concentrators,"The impact of magnetic domains in magnetic flux concentrators is studied
+using the simulation software MuMax3. First, the simulation parameters are
+validated using experimental results from magnetic force microscopy; second the
+simulation output is benchmarked with the one obtained using Comsol
+Multiphysics. Finally, the impact of magnetic domain is assessed, showing how
+micromagnetic effects can become relevant, if not dominant, when scaling the
+gap between the MFC and the sensor.",2106.00370v2
+2021-10-16,A stretched exponential-based approach for the magnetic properties of spin glasses,"The spin glasses show intriguing characteristic features that are not well
+understood yet, as for instance its aging, rejuvenation and memory effects.
+Here a model based on a stretched exponential decay of its magnetization is
+proposed, which can describe the main magnetic features of spin glasses
+observed in experiments as the time-decay of thermoremament magnetization, the
+relaxation of zero field cooled magnetization, the ac and dc magnetization as a
+function of temperature and others. In principle, the here proposed model could
+be adapted to describe other glassy systems.",2110.08625v2
+2021-12-06,Magnetism of two-dimensional magnets in the presence of random fields,"In low-dimensional magnets, thermal agitation and spatial disorders generate
+strong spin fluctuations that suppress the long-range magnetic ordering. We
+develop an analytical equation for the equilibrium magnetization of
+two-dimensional magnets at finite temperatures in the presence of the random
+magnetic field. We find that the random field induces a first-order phase
+transition in addition to the reduced Curie temperature. The first-order phase
+transition persists even in the presence of the moderate external magnetic
+field.",2112.03343v1
+2022-04-11,Deformation of a magnetic liquid drop and unsteady flow inside and outside it in a non-stationary magnetic field,"Small steady-state deformational oscillations of a drop of a viscous magnetic
+liquid in a non-stationary uniform magnetic field are theoretically
+investigated for low Reynolds numbers. The drop is suspended in another viscous
+magnetic liquid immiscible with the former. The non-stationary magnetic field
+causes flow inside and outside the drop. The inertia is taken into account by
+regarding the flow as essentially unsteady. The variation of the magnetic field
+is so slow that the approximation of quasi-stationary magnetic field may be
+used.",2204.05387v2
+2022-10-06,MagNet: machine learning enhanced three-dimensional magnetic reconstruction,"Three-dimensional (3D) magnetic reconstruction is vital to the study of novel
+magnetic materials for 3D spintronics. Vector field electron tomography (VFET)
+is a major in house tool to achieve that. However, conventional VFET
+reconstruction exhibits significant artefacts due to the unavoidable presence
+of missing wedges. In this article, we propose a deep-learning enhanced VFET
+method to address this issue. A magnetic textures library is built by
+micromagnetic simulations. MagNet, an U-shaped convolutional neural network, is
+trained and tested with dataset generated from the library. We demonstrate that
+MagNet outperforms conventional VFET under missing wedge. Quality of
+reconstructed magnetic induction fields is significantly improved.",2210.03066v1
+2022-10-30,Controlling magnetic anisotropy in amplitude expansion of phase field crystal model,"The amplitude expansion for a magnetic phase-field-crystal (magnetic APFC)
+model enables a convenient coarse-grained description of crystalline structures
+under the influence of magnetic fields. Considering higher-order magnetic
+coupling terms, we demonstrate the possibility of tuning the magnetic
+anisotropy in these models. This allows for reproducing the easy and hard
+direction of magnetization. Such a result can be achieved without increasing
+the computational cost, enabling simulations of the manipulation of dislocation
+networks and microstructures in ferromagnetic materials. As a demonstration, we
+report on the simulation of the shrinkage of a spherical grain with the
+magnetic anisotropy of Fe.",2210.16855v1
+2023-12-13,Enhanced Magnetic Field Amplification by Ion-Beam Weibel Instability in Weakly Magnetized Astrophysical Shocks,"We examine the evolution of ion-beam Weibel instability at strong
+collisionless shocks in weakly magnetized media. We find that a finite
+background magnetic field substantially affects both linear and nonlinear
+phases of the instability, depending on whether the background electrons behave
+magnetized or not. Particle-in-cell simulations for magnetized electrons
+identify a dynamo-like mechanism of magnetic field amplification, which
+eventually leads to spontaneous magnetic reconnection. We conclude that this
+scenario is applicable to typical young supernova remnant shocks.",2312.07933v1
+2019-11-14,Real time observation of a stationary magneton,"The magnetic dipole field geometry of subatomic elementary particles like the
+electron differs from the classical macroscopic field imprint of a bar magnet.
+It resembles more like an eight figure or else joint double quantum-dots
+instead of the classical, spherical more uniform field of a bar magnet. This
+actual subatomic quantum magnetic field of an electron at rest, is called
+Quantum Magnet or else a Magneton. Normally, a macroscale bar magnet should
+behave like a relative giant Quantum Magnet with identical magnetic dipole
+field imprint since all of its individual magnetons collectively inside the
+material, dipole moments are uniformly aligned forming the total net field of
+the magnet. However due to Quantum Decoherence (QDE) phenomenon at the
+macroscale and macroscopic magnetic field imaging sensors limitations which
+cannot pickup these rapid quantum magnetization fluctuations, this field is
+masked and not visible at the macroscale. By using the relative inexpensive
+submicron resolution Ferrolens quantum magnetic optical sensor and method, we
+can actually make this net magneton field visible on macroscale magnets. We
+call this net total field herein, Quantum Field of Magnet (QFM) differentiating
+it therefore from the field of the single subatomic magneton thus quantum
+magnet. Additionally, the unique potential of the Ferrolens device to display
+also the magnetic flux lines of this macroscopically projected giant Magenton
+gives us the unique opportunity to study the individual magnetic flux lines
+geometrical pattern that of a single subatomic magneton. We describe this
+particular magnetic flux of the magneton observed, quantum magnetic flux.
+Therefore a novel observation has been made that the QFM of the Magnet-Magneton
+consists of a dipole vortex shaped magnetic flux geometrical pattern
+responsible for creating the classical macroscopic N-S field of the magnet.",1911.05735v1
+2002-05-12,The Role of Magnetic Helicity Transport in Nonlinear Galactic Dynamos,"We consider the magnetic helicity balance for the galactic dynamo in the
+framework of the local dynamo problem, as well as in the no-z model (which
+includes explicitly the radial distribution of the magnetic fields). When
+calculating the magnetic helicity balance we take into account the
+redistribution of the small-scale and large-scale magnetic fields between the
+magnetic helicities, as well as magnetic helicity transport and diffusion due
+to small-scale turbulence. We demonstrate that the magnetic helicity flux
+through the galactic disc boundaries leads to a steady-state magnetic field
+with magnetic energy comparable to the equipartition energy of the turbulent
+motions of the interstellar medium. If such flux is ignored, the steady-state
+magnetic field is found to be much smaller than the equipartition field. The
+total magnetic helicity flux through the boundaries consists of both an
+advective flux and a diffusive flux. The exact ratio of these contributions
+seems not to be crucial for determining the strength of the steady-state
+magnetic field and its structure. However at least some diffusive contribution
+is needed to smooth the magnetic helicity profile near to the disc boundaries.
+The roles of various transport coefficients for magnetic helicity are
+investigated, and the values which lead to magnetic field configurations
+comparable with those observed are determined.",0205165v1
+2004-01-22,The magnetic field of pulsars and the gravito-magnetic theory,"Many authors have considered a gravitational origin of the magnetic field of
+celestial bodies. Especially, the so-called Wilson-Blackett formula has been
+investigated, both theoretically and observationally. It appeared possible to
+deduce this formula from general relativity, e. g., by application of a special
+interpretation of gravito-magnetic theory. More consequences of the latter
+theory for pulsars will be considered in this work. As an example, the standard
+quadrupolar charge density for pulsars can be deduced from the gravito-magnetic
+theory. Moreover, a new magnetic dipole moment from electromagnetic origin is
+found, generated in the basic magnetic field from gravito-magnetic origin. In
+general, for thirteen accreting, slowly rotating, binary pulsars the agreement
+between the observed magnetic field and the gravito-magnetic prediction is
+better than between the observed value and the value from the standard magnetic
+dipole radiation model. At present, an analogous comparison for five isolated
+pulsars appears to be difficult. For a sample of 100 pulsars the averaged
+(gravito-)magnetic field, extracted from the magnetic dipole spin-down model,
+is in fair agreement with the gravito-magnetic prediction. Unfortunately, the
+(gravito-)magnetic field has not yet directly been measured. Finally, it is
+found that the first and second order braking indices only depend on the
+magnetic field from electromagnetic origin.",0401468v1
+2001-08-29,The Finite Energy Constant Magnetization of the Two - Dimensional Ising Model,"We suggest the new definition of the magnetization. For the two - dimensional
+Ising model with the free boundary conditions we calculate any derivative of
+this magnetization for zero magnetic field.",0108489v1
+2002-07-08,The Magnetization by the Finite Energy Constant Magnetic Field in the Two - Dimentional Ising Model,"We suggest the new definition of the magnetization. For the two - dimensional
+Ising model with the free boundary conditions we calculate this magnetization.",0207200v1
+2009-11-12,Coherent states in the presence of a variable magnetic field,"We introduce magnetic coherent states for a particle in a variable magnetic
+field. They provide a pure state quantization of the phase space R^{2N} endowed
+with a magnetic symplectic form.",0911.2451v1
+2010-06-07,Solitary Magnetic Bubbles,"Stability and attractor property of free-floating axisymmetric magnetic
+bubbles in high-conductivity plasmas is (tentatively, numerically)
+demonstrated. The existence of compact non-singular axisymmetric magnetic
+equilibria is proved. Being attractors, the solitary magnetic bubbles should
+exist in nature.",1006.1368v1
+2011-06-18,Magnetic curves corresponding to Killing magnetic fields in $E^3$,"We explicitly determine all magnetic curves corresponding to the Killing
+magnetic fields on the 3-dimensional Euclidean space.",1106.3673v1
+2012-01-13,Development for Hardware for Programming of Spatial Magnetic Field Distributions in Nuclear Magnetic Resonance and Magnetic Resonance Imaging,"The proposal of a project aimed on a design of hardware for programming 3D
+Magnetic Field shapes over sample volume in NMR and MRI is described.",1201.2764v1
+2012-09-27,Growth of a localized seed magnetic field in a turbulent medium,"Turbulence dynamo deals with amplification of a seed magnetic field in a
+turbulent medium and has been studied mostly for uniform or spatially
+homogeneous seed magnetic fields. However, some astrophysical processes (e.g.
+jets from active galaxies, galactic winds, or ram-pressure stripping in galaxy
+clusters) can provide localized seed magnetic fields. In this paper, we
+numerically study amplification of localized seed magnetic fields in a
+turbulent medium. Throughout the paper, we assume that driving scale of
+turbulence is comparable to the size of the system. Our findings are as
+follows. First, turbulence can amplify a localized seed magnetic field very
+efficiently. The growth rate of magnetic energy density is as high as that for
+a uniform seed magnetic field. This result implies that a magnetic field
+ejected from an astrophysical object can be a viable source of magnetic field
+in a cluster. Second, the localized seed magnetic field disperses and fills the
+whole system very fast. If turbulence in a system (e.g. a galaxy cluster or a
+filament) is driven at large scales, we expect that it takes a few large-eddy
+turnover times for magnetic field to fill the whole system. Third, growth and
+turbulence diffusion of a localized seed magnetic field are also fast in high
+magnetic Prandtl number turbulence. Fourth, even in decaying turbulence, a
+localized seed magnetic field can ultimately fill the whole system. Although
+the dispersal rate of magnetic field is not fast in purely decaying turbulence,
+it can be enhanced by an additional forcing.",1209.6130v1
+2013-01-28,Two-dimensional Ising model in a finite magnetic field for the square lattice of infinite sites-Partition function and Magnetization,"The partition function and magnetization equations are derived for the
+two-dimensional nearest neighbour Ising models in a magnetic field.",1302.1084v1
+2014-07-08,Competing magnetic phases and field-induced dynamics in DyRuAsO,"Analysis of neutron diffraction, dc magnetization, ac magnetic
+susceptibility, heat capacity, and electrical resistivity for DyRuAsO in an
+applied magnetic field are presented at temperatures near and below those at
+which the structural distortion (T_S = 25 K) and subsequent magnetic ordering
+(T_N = 10.5 K) take place. Powder neutron diffraction is used to determine the
+antiferromagnetic order of Dy moments of magnitude 7.6(1) mu_B in the absence
+of a magnetic field, and demonstrate the reorientation of the moments into a
+ferromagnetic configuration upon application of a magnetic field. Dy magnetism
+is identified as the driving force for the structural distortion. The magnetic
+structure of analogous TbRuAsO is also reported. Competition between the two
+magnetically ordered states in DyRuAsO is found to produce unusual physical
+properties in applied magnetic fields at low temperature. An additional phase
+transition near T* = 3 K is observed in heat capacity and other properties in
+fields greater than about 3 T. Magnetic fields of this magnitude also induce
+spin-glass-like behavior including thermal and magnetic hysteresis, divergence
+of zero-field-cooled and field-cooled magnetization, frequency dependent
+anomalies in ac magnetic susceptibility, and slow relaxation of the
+magnetization. This is remarkable since DyRuAsO is a stoichiometric material
+with no disorder detected by neutron diffraction, and suggests analogies with
+spin-ice compounds and related materials with strong geometric frustration.",1407.2184v1
+2016-08-16,Magnetic Dirichlet Laplacian with radially symmetric magnetic field,"The aim of the paper is to derive spectral estimates on the eigenvalue
+moments of the magnetic Dirichlet Laplacian defined on the two-dimensional disk
+with a radially symmetric magnetic field.",1608.04555v1
+2017-03-30,Relative magnetic helicity as a diagnostic of solar eruptivity,"The discovery of clear criteria that can deterministically describe the
+eruptive state of a solar active region would lead to major improvements on
+space weather predictions. Using series of numerical simulations of the
+emergence of a magnetic flux rope in a magnetized coronal, leading either to
+eruptions or to stable configurations, we test several global scalar quantities
+for the ability to discriminate between the eruptive and the non-eruptive
+simulations. From the magnetic field generated by the three-dimensional
+magnetohydrodynamical simulations, we compute and analyse the evolution of the
+magnetic flux, of the magnetic energy and its decomposition into potential and
+free energies, and of the relative magnetic helicity and its decomposition.
+Unlike the magnetic flux and magnetic energies, magnetic helicities are able to
+markedly distinguish the eruptive from the non-eruptive simulations. We find
+that the ratio of the magnetic helicity of the current-carrying magnetic field
+to the total relative helicity presents the highest values for the eruptive
+simulations, in the pre-eruptive phase only. We observe that the eruptive
+simulations do not possess the highest value of total magnetic helicity. In the
+framework of our numerical study, the magnetic energies and the total relative
+helicity do not correspond to good eruptivity proxies. Our study highlights
+that the ratio of magnetic helicities diagnoses very clearly the eruptive
+potential of our parametric simulations. Our study shows that
+magnetic-helicity-based quantities may be very efficient for the prediction of
+solar eruptions.",1703.10562v1
+2017-05-17,Magnetic Transport in Spin Antiferromagnets for Spintronics Applications,"Had magnetic monopoles been ubiquitous as electrons are, we would probably
+have had a different form of matter, and power plants based on currents of
+these magnetic charges would have been a familiar scene of modern technology.
+Magnetic dipoles do exist, however, and in principle one could wonder if we can
+use them to generate magnetic currents. In the present work, we address the
+issue of generating magnetic currents and magnetic thermal currents in
+electrically-insulating low-dimensional Heisenberg antiferromagnets by invoking
+the (broken) electricity-magnetism duality symmetry. The ground state of these
+materials is a spin-liquid state that can be described well via~the
+Jordan--Wigner fermions, which permit an easy definition of the magnetic
+particle and thermal currents. The magnetic and magnetic thermal conductivities
+are calculated in the present work using the bond--mean field theory. The
+spin-liquid states in these antiferromagnets are either gapless or gapped
+liquids of spinless fermions whose flow defines a current just as the one
+defined for electrons in a Fermi liquid. The driving force for the magnetic
+current is a magnetic field with a gradient along the magnetic conductor. We
+predict the generation of a magneto-motive force and realization of magnetic
+circuits using low-dimensional Heisenberg antiferromagnets. The present work is
+also about claiming that what the experiments in spintronics attempt to do is
+trying to treat the magnetic degrees of freedoms on the same footing as the
+electronic ones.",1705.06318v2
+2017-12-26,Evolution of Relative Magnetic Helicity: New Boundary Conditions for the Vector Potential,"We recently proposed a method to calculate the relative magnetic helicity in
+a finite volume for a given magnetic field which however required the flux to
+be balanced separately on all the sides of the considered volume. In order to
+allow finite magnetic fluxes through the boundaries, a Coulomb gauge is
+constructed that allows for global magnetic flux balance. We tested and
+verified our method in a theoretical fore-free magnetic field model. We apply
+the new method to the former calculation data and found a difference of less
+than 1.2\%. We also applied our method to the magnetic field above active
+region NOAA 11429 obtained by a new photospheric-data-driven MHD model code
+GOEMHD3. We analyzed the magnetic helicity evolution in the solar corona using
+our new method. It was found that the normalized magnetic helicityis equal to
+-0.038 when fast magnetic reconnection is triggered. This value is comparable
+to the previous value (-0.029) in the MHD simulations when magnetic
+reconnection happened and the observed normalized magnetic helicity (-0.036)
+from the eruption of newly emerging active regions. We found that only 8\% of
+the accumulated magnetic helicity is dissipated after it is injected through
+the bottom boundary. This is in accordance with the Woltjer conjecture. Only
+2\% of magnetic helicity injected from the bottom boundary escapes through the
+corona. This is consistent with the observation of magnetic clouds, which could
+take away magnetic helicity into the interplanetary space, in the case
+considered here, several halo CMEs and two X-class solar flares origin from
+this active region.",1712.09219v1
+2018-11-30,Double bit in-plane magnetic skyrmions on a track,"A magnetic skyrmion isusually refers to a twisted spin texture surrounded by
+uniformly aligned out-of-plane spinsin the background of a uniformly magnetized
+state. The invariance of the magnetic skyrmion conserves its topological charge
+under any continuous transformations of the spin textures, leads to which
+represents the robustness of a magnetic skyrmion their texture against external
+perturbations, making it ideal to use skyrmions as . Such a behaviour is
+required for an ideal information carriers. To date, most magnetic skyrmion
+studies have been performedfocused on in perpendicularly magnetized systems,
+where the skyrmion topological number is determined by the relative orientation
+between the core and /outer perpendicular magnetization directions of the
+skyrmion is either up/down or down/up. Here we show that there also exists a
+new type of magnetic skyrmion with surrounding spins to be uniformly aligned to
+the in-plane direction. By continuous transformation and relaxation of the spin
+textures of out-of-plane skyrmions, we showed that an in-plane skyrmion, where
+the background magnetization is in the in-plane direction, is also possible.
+Different from the conventional perpendicular magnetic skyrmionsContrary to the
+skyrmions in a perpendicularly magnetized state, the in-plane magnetic
+skyrmions with opposite signs of topological charges can inherentlycharges can
+inherently coexist in the in-plane magnetization system coexist. Moreover, the
+iIn-plane skyrmions of opposite charge can move together by an electric current
+and exhibit with an opposite spin Hall effect. These findings showdemonstrate
+the inherent possibility of a double-bit transfer in a single magnetic wire
+that is not possible in a perpendicularly magnetized system.",1811.12552v1
+2019-10-13,A systematically study of thermal width of heavy quarkonia in a finite temperature magnetized background from holography,"By simulating the finite temperatures magnetized background in the RHIC and
+LHC energies, we systematically study the characteristics of thermal widths and
+potentials of heavy quarkonia. It is found that the magnetic field has less
+influence on the real potential, but has a significant influence on the
+imaginary potential, especially in the low deconfined temperature. Extracted
+from the effect of thermal worldsheet fluctuations about the classical
+configuration, the thermal width of $\Upsilon(1s)$ in the finite temperature
+magnetized background is investigated. It is found that at the low deconfined
+temperature the magnetic field can generate a significant thermal fluctuation
+of the thermal width of $\Upsilon(1s)$, but with the increase of temperature,
+the effect of magnetic field on the thermal width becomes less important, which
+means the effect of high temperature completely exceeds that of magnetic field
+and magnetic field become less important at high temperature. The thermal width
+decreases with the increasing rapidity at the finite temperature magnetized
+background. It is also observed that the effect of the magnetic field on the
+thermal width when dipole moving parallel to the magnetic field direction are
+larger than that moving perpendicular to the magnetic field direction, which
+implies that the magnetic field tends to enhance thermal fluctuation when
+dipole moving parallel to the direction of magnetic field. The thermal width of
+$\Upsilon(1S)$ hardly changes with the increasing temperature when dipole
+moving perpendicular to the magnetic field. But when dipole moving parallel to
+the magnetic field, the thermal width at low temperature is obviously larger
+than that at high temperature.",1910.05668v1
+2021-09-03,"Investigating the Magnetic Field outside small Accelerator Magnet Analogs via Experiment, Simulation, and Theory","Particle accelerators use powerful and complex magnetic fields to turn,
+shape, and eventually collide beams of near-light-speed particles, yet the
+fundamental magnetic principles behind the accelerator magnets can be
+understood by undergraduate students. In this paper we use small-scale
+accelerator magnet analogs in a multi-faceted, low-cost exploration of the
+magnetic field exterior to accelerator magnets. These fields are best
+understood using the multipole expansion of the field. If we assume that the
+magnetic field is created by ideal magnetic dipoles, we can derive a
+theoretical model that shows that each accelerator magnet configuration is
+dominated by a single multipole moment and obeys $B \propto 1/r^{l+2}$, where
+$l$ is the multipole order (with $l = 1, 2, 3, 4$ for the dipole, quadrupole,
+octopole, and hexadecapole moments, respectively). Using commercially available
+NdFeB magnets and the magnetic field sensor inside a smartphone, we
+experimentally verify the power-law dependence of the accelerator magnet
+configurations. Finally, we use the open-source Python library Magpylib to
+simulate the magnetic field of the permanent magnet configurations, showing
+good agreement between theory, experiment, and simulation.",2109.03057v4
+2021-12-02,Heisenberg representation of nonthermal ultrafast laser excitation of magnetic precessions,"We derive the Heisenberg representation of the ultrafast inverse Faraday
+effect that provides the time evolution of magnetic vectors of a magnetic
+system during its interaction with a laser pulse. We obtain a time-dependent
+effective magnetic operator acting in the Hilbert space of the total angular
+momentum that describes a process of nonthermal excitation of magnetic
+precessions in an electronic system by a circularly polarized laser pulse. The
+magnetic operator separates the effect of the laser pulse on the magnetic
+system from other magnetic interactions. The effective magnetic operator
+provides the equations of motion of magnetic vectors during the excitation by
+the laser. We show that magnetization dynamics calculated with these equations
+is equivalent to magnetization dynamics calculated with the time-dependent
+Schr\""odinger equation, which takes into account the interaction of an
+electronic system with the electric field of light. We model and compare
+laser-induced precessions of magnetic sublattices of an easy-plane and an
+easy-axis antiferromagnetic systems. Using these models, we show how the
+ultrafast inverse Faraday effect induces a net magnetic moment in
+antiferromagnets and demonstrate that a crystal field environment and the
+exchange interaction play essential roles for laser-induced magnetization
+dynamics even during the action of a pump pulse. Using our approach, we show
+that light-induced precessions can start even during the action of the pump
+pulse with a duration several tens times shorter than the period of induced
+precessions and affect the position of magnetic vectors after the action of the
+pump pulse.",2112.01350v1
+2022-07-20,Hot magnetic halo of NGC628 (M74),"In several spiral galaxies that are observed face-on, large-scale ordered
+magnetic fields (the so-called magnetic arms) were found. One of the
+explanations was the action of the magnetic reconnection, which leads to a
+higher ordering of the magnetic fields. Because it simultaneously converts the
+energy of the magnetic fields into thermal energy of the surroundings, magnetic
+reconnection has been considered as a heating mechanism of the interstellar
+medium for many years. Until recently, no clear observational evidence for this
+phenomenon was found. We search for possible signatures of gas heating by
+magnetic reconnection effects in the radio and X-ray data for the face-on
+spiral galaxy NGC628 (M74), which presents pronounced magnetic arms and
+evidence for vertical magnetic fields. The strengths and energy densities of
+the magnetic field in the spiral and magnetic arms were derived, as were the
+temperatures and thermal energy densities of the hot gas, for the disk and halo
+emission. In the regions of magnetic arms, higher order and lower energy
+density of the magnetic field is found than in the stellar spiral arms. The
+global temperature of the hot gas is roughly constant throughout the disk. The
+comparison of the findings with those obtained for the starburst galaxy M83
+suggests that magnetic reconnection heating may be present in the halo of
+NGC628. The joint analysis of the properties of the magnetic fields and the hot
+gas in NGC628 also provided clues for possible tidal interaction with the
+companion galaxy.",2207.09917v1
+2022-09-07,Atypical magnetic behavior in the incommensurate $[CH_3NH_3][Ni(HCOO)_3]$ hybrid perovskite,"A plethora of temperature induced phase transitions have been observed in
+$[CH_3NH_3][M(HCOO)_3]$ compounds, where M is Co(II) or Ni(II). Among them, the
+nickel compound exhibits a combination of magnetic and nuclear
+incommensurabil-ity below N\'eel temperature. Despite the fact that the
+zero-field behavior has been previously addressed, here we study in depth the
+macroscopic magnetic behavior of this compound to unveil the origin of the
+atypical magnetic response found in it and in its parent family of formate
+perovskites. In particular, they show a puzzling magnetization reversal in the
+curves measured starting from low temperatures, after cooling under zero field.
+The first atypical phenomena is the im-possibility of reaching zero
+magnetization, even by nullifying the applied external field and even
+compensating it for the influence earth's magnetic field. Relatively large
+magnetic fields are needed to switch the magnetization from negative to
+positive values or vice versa, which is compatible with a soft-ferromagnetic
+system. The atypical path found in its first magnetization curve and hysteresis
+loop at low temperatures is the most noticeable feature. The magnetization
+curve switches from more than 1200 Oe from the first magnetization loop to the
+subsequent magnetization loops. A feature that cannot be explained using a
+model based on unbalanced pair of domains. As a result, we decipher this
+behavior in light of the incommensurate structure of this material. We propose,
+in particular, that the applied magnetic field induces a mag-netic phase
+transition from a magnetically incommensurate structure to a magnetically
+commensurate structure.",2209.03093v1
+2022-12-02,A promising formation channel for symbiotic X-ray binaries: cases of IGR J17329-2731 and 4U 1700+24,"Recent observations demonstrate that the symbiotic X-ray binary (SyXB) IGR
+J17329-2731 contains a highly magnetized neutron star (NS) which accretes
+matter through the wind from its giant star companion, and suggest that 4U
+1700+24 may also have a highly magnetized NS. Accretion-induced collapse (AIC)
+from oxygen-neon-magnesium white dwarf (ONeMg WD) + red giant (RG) star
+binaries is one promising channel to form these SyXBs, while other long
+standing formation channels have difficulties to produce these SyXBs. By
+considering non-magnetic and magnetic ONeMg WDs, I investigate the evolution of
+ONeMg WD + RG binaries with the MESA stellar evolution code for producing SyXBs
+with non-magnetic or magnetized NSs. In the pre-AIC evolution with magnetic
+confinement, the mass accumulation efficiency of the accreting WD is increased
+at low mass transfer rate compared to the non-magnetic case. The newborn NSs
+formed via AIC of highly magnetized WDs could inherit the large magnetic field
+through conservation of magnetic flux, and the systems could have a long age
+compatible with that of the red giant companions. These young and highly
+magnetized NSs could accrete matters from the stellar wind of the giant
+companions to that shine as those observed SyXBs, and could preserve their high
+magnetic field during this time. The MESA calculation results show that the
+initial parameter (initial RG mass and orbital period) space for the AIC with
+magnetic confinement to form SyXBs with highly magnetized NSs shifts to be
+lower and narrower compared to that of the no magnetic confinement case.",2212.00997v2
+2023-07-28,Reversible magnetic domain reorientation induced by magnetic field pulses with fixed direction,"Nanoscale magnetic domains with controllable configurations could be used for
+classical and quantum applications, where the switching of magnetization
+configurations is an essential operation for information processing. Here, we
+report that the magnetic domain reorientation in a notched ferromagnetic
+nanotrack can be realized and effectively controlled by applying uniform
+magnetic field pulses in a fixed in-plane direction perpendicular to the
+nanotrack. Our micromagnetic simulation results show that the configurations of
+magnetic domains in the notched nanotrack can be switched between a
+head-to-head state and a tail-to-tail state in a reversible manner driven by
+magnetic field pulses, while it is unnecessary to reverse the direction of the
+magnetic field. Such a unique magnetic domain reorientation dynamics is found
+to depend on magnetic parameters and nanotrack geometries. The reorientation
+dynamics of magnetic domains also depends on the strength and length of the
+applied magnetic field pulse. In addition, we point out that the notches at the
+center of the nanotrack play an important role for the stabilization of the
+head-to-head and tail-to-tail states during the magnetic domain reorientation.
+We also qualitatively explain the field-induced reorientation phenomenon with a
+simplified two-dimensional macrospin model. Our results may make it possible to
+build spintronic devices driven by a fixed magnetic field. Our findings may
+also motivate future studies to investigate the classical and quantum
+applications based on nanoscale magnetic domains.",2307.15263v1
+2023-09-14,Disentangling the Entangled Linkages of Relative Magnetic Helicity,"Magnetic helicity, $H$, measures magnetic linkages in a volume. The early
+theoretical development of helicity focused on magnetically closed systems in
+$\mathcal{V}$ bounded by $\mathcal{S}$. For magnetically closed systems,
+$\mathcal{V}\in\mathbb{R}^3=\mathcal{V}+\mathcal{V}^*$, no magnetic flux
+threads the boundary, $\hat{\boldsymbol{n}}\cdot\boldsymbol{B}|_\mathcal{S}=0$.
+Berger and Field (1984) and Finn and Antonsen (1985) extended the definition of
+helicity to relative helicity, $\mathcal{H}$, for magnetically open systems
+where magnetic flux may thread the boundary. Berger (1999,2003) expressed this
+relative helicity as two gauge invariant terms that describe the self helicity
+of magnetic field that closes inside $\mathcal{V}$ and the mutual helicity
+between the magnetic field that threads the boundary $\mathcal{S}$ and the
+magnetic field that closes inside $\mathcal{V}$. The total magnetic field that
+permeates $\mathcal{V}$ entangles magnetic fields that are produced by current
+sources $\boldsymbol{J}$ in $\mathcal{V}$ with magnetic fields that are
+produced by current sources $\boldsymbol{J}^*$ in $\mathcal{V}^*$. Building on
+this fact, we extend Berger's expressions for relative magnetic helicity to
+eight gauge invariant quantities that simultaneously characterize both of these
+self and mutual helicities and attribute their origins to currents
+$\boldsymbol{J}$ in $\mathcal{V}$ and/or $\boldsymbol{J}^*$ in $\mathcal{V}^*$,
+thereby disentangling the domain of origin for these entangled linkages. We
+arrange these eight terms into novel expressions for internal and external
+helicity (self) and internal-external helicity (mutual) based on their domain
+of origin. The implications of these linkages for interpreting magnetic energy
+is discussed and new boundary observables are proposed for tracking the
+evolution of the field that threads the boundary.",2309.07776v1
+1996-12-23,A Fresh Look at Axions and SN 1987A,"We re-examine the very stringent limits on the axion mass based on the
+strength and duration of the neutrino signal from SN 1987A, in the light of new
+measurements of the axial-vector coupling strength of nucleons, possible
+suppression of axion emission due to many-body effects, and additional emission
+processes involving pions. The suppression of axion emission due to nucleon
+spin fluctuations induced by many-body effects degrades previous limits by a
+factor of about 2. Emission processes involving thermal pions can strengthen
+the limits by a factor of 3-4 within a perturbative treatment that neglects
+saturation of nucleon spin fluctuations. Inclusion of saturation effects,
+however, tends to make the limits less dependent on pion abundances. The
+resulting axion mass limit also depends on the precise couplings of the axion
+and ranges from 0.5x10**(-3) eV to 6x10**(-3) eV.",9612222v1
+1997-11-10,Confronting Synchrotron Shock and Inverse Comptonization Models with GRB Spectral Evolution,"The time-resolved spectra of gamma-ray bursts (GRBs) remain in conflict with
+many proposed models for these events. After proving that most of the bursts in
+our sample show evidence for spectral ""shape-shifting"", we discuss what
+restrictions that BATSE time-resolved burst spectra place on current models. We
+find that the synchrotron shock model does not allow for the steep low-energy
+spectral slope observed in many bursts, including GRB 970111. We also determine
+that saturated Comptonization with only Thomson thinning fails to explain the
+observed rise and fall of the low-energy spectral slope seen in GRB 970111 and
+other bursts. This implies that saturated Comptonization models must include
+some mechanism which can cause the Thomson depth to increase intially in
+pulses.",9711100v1
+1998-10-02,Gravity-modes in ZZ Ceti Stars. II. Effects of Turbulent Dissipation,"We investigate dynamical interactions between turbulent convection and g-mode
+pulsations in ZZ Ceti variables (DAVs). Since our understanding of turbulence
+is rudimentary, we are compelled to settle for order of magnitude results. A
+key feature of these interactions is that convective response times are much
+shorter than pulsation periods. Thus the dynamical interactions enforce near
+uniform horizontal velocity inside the convection zone. They also give rise to
+a narrow shear layer in the region of convective overshoot at the top of the
+radiative interior. Turbulent damping inside the convection zone is negligible
+for all modes, but that in the region of convective overshoot may be
+significant for a few long period modes near the red edge of the instability
+strip. These conclusions are in accord with those reached earlier by Brickhill.
+Our major new result concerns nonlinear damping arising from the
+Kelvin-Helmholtz instability of the aforementioned shear layer. Amplitudes of
+overstable modes saturate where dissipation due to this instability balances
+excitation by convective driving. This mechanism of amplitude saturation is
+most effective for long period modes, and it may play an important role in
+defining the red edge of the instability strip.",9810038v1
+1999-03-29,GRB990123: The Case for Saturated Comptonization,"The recent simultaneous detection of optical, X-ray and gamma-ray photons
+from GRB990123 during the burst provides the first broadband multi-wavelength
+characterization of the burst spectrum and evolution. Here we show that a
+direct correlation exists between the time-varying gamma-ray spectral shape and
+the prompt optical emission. This combined with the unique signatures of the
+time-resolved spectra of GRB990123 convincingly supports earlier predictions of
+the saturated Comptonization model. Contrary to other suggestions, we find that
+the entire continuum from optical to gamma-rays can be generated from a single
+source of leptons (electrons and pairs). The optical flux only appears to lag
+the gamma-ray flux due to the high initial Thomson depth of the plasma. Once
+the plasma has completely thinned out, the late time afterglow behavior of our
+model is the same as in standard models based on the Blandford-McKee (1976)
+solution.",9903438v1
+1999-05-03,Neutron star properties in the quark-meson coupling model,"The effects of internal quark structure of baryons on the composition and
+structure of neutron star matter with hyperons are investigated in the
+quark-meson coupling (QMC) model. The QMC model is based on mean-field
+description of nonoverlapping spherical bags bound by self-consistent exchange
+of scalar and vector mesons. The predictions of this model are compared with
+quantum hadrodynamic (QHD) model calibrated to reproduce identical nuclear
+matter saturation properties. By employing a density dependent bag constant
+through direct coupling to the scalar field, the QMC model is found to exhibit
+identical properties as QHD near saturation density. Furthermore, this modified
+QMC model provides well-behaved and continuous solutions at high densities
+relevant to the core of neutron stars. Two additional strange mesons are
+introduced which couple only to the strange quark in the QMC model and to the
+hyperons in the QHD model. The constitution and structure of stars with
+hyperons in the QMC and QHD models reveal interesting differences. This
+suggests the importance of quark structure effects in the baryons at high
+densities.",9905010v1
+1999-05-06,How Saturated are Absorption Lines in the Broad Absorption Line Quasar PG 1411+442 ?,"Recently, convincing evidence was found for extremely large X-ray absorption
+by column densities $> 10^{23} cm^{-2}$ in broad absorption line quasars. One
+consequence of this is that any soft X-ray emission from these QSOs would be
+the scattered light or leaked light from partially covering absorbing material.
+A detection of the unabsorbed soft X-ray and absorbed hard X-ray compo nent
+will allow to determine the total column density as well as the effective
+covering factor of the absorbing material, which can be hardly obtained from
+the UV absorption lines. Brinkmann et al. (1999) showed that both the
+unabsorbed and absorbed components are detected in the nearby very bright broad
+absorption line quasar PG 1411+442. In this letter, we make a further analysis
+of the broad band X-ray spectrum and the UV spectrum from HST, and demonstrate
+that broad absorption lines are completely saturated at the bottom of
+absorption troughs.",9905054v1
+1999-05-14,Observations of Small Scale ISM Structure in Dense Atomic Gas,"We present high resolution (R~170,000) Kitt Peak National Observatory Co'ude
+Feed telescope observations of the interstellar KI 7698 angstrom line towards 5
+multiple star systems with saturated NaI components. We compare the KI
+absorption line profiles in each of the two (or three) lines of sight in these
+systems, and find significant differences between the sight-lines in 3 out of
+the 5 cases. We infer that the small scale structure traced by previous NaI
+observations is also present in at least some of the components with saturated
+NaI absorption lines, and thus the small scale structures traced by the neutral
+species are occurring at some level in clouds of all column densities. We
+discuss the implications of that conclusion and a potential explanation by
+density inhomogeneities.",9905189v1
+1999-05-18,Strong Field Gravity and X-Ray Observations of 4U1820-30,"The behavior of quasi-periodic oscillations (QPOs) at frequencies near 1 kHz
+in the x-ray emission from the neutron star x-ray binary 4U1820-30 has been
+interpreted as evidence for the existence of the marginally stable orbit, a key
+prediction of strong-field general relativity. The signature of the marginally
+stable orbit is a saturation in QPO frequency, assumed to track inner disk
+radius, versus mass accretion rate. Previous studies of 4U1820-30 have used
+x-ray count rate as an indicator of mass accretion rate. However, x-ray count
+rate is known to not correlate robustly with mass accretion rate or QPO
+frequency in other sources. Here, we examine the QPO frequency dependence on
+two other indicators of mass accretion rate: energy flux and x-ray spectral
+shape. Using either of these indicators, we find that the QPO frequency
+saturates at high mass accretion rates. We interpret this as strong evidence
+for the existence of the marginally stable orbit.",9905236v1
+2000-04-14,The saturation of disk heating in the solar neighborhood and evidence for a merger 9 Gyrs ago,"We re-examine the age-velocity dispersion relation in the solar neighborhood
+using improved stellar age estimates that are based on Hipparcos parallaxes and
+recent stellar evolution calculations. The resulting relation shows that the
+Milky Way stellar disk was relatively quiescent, suffering little heating or
+dispersion increase between 3 and 9 Gyrs. However, at an age of 9 Gyrs there is
+an abrupt increase in the stellar velocity dispersions. To explain the abrupt
+increase (by almost a factor of 2) in dispersions we propose that the Milky Way
+suffered a minor merger 9 Gyrs ago that created the thick disk. The quiescent
+phase is consistent with inefficient heating caused by scattering from tightly
+wound transient spiral structure. It is possible that many galaxy disks have
+radial velocity dispersions at the point where heating from spiral structure
+becomes inefficient. Surface brightness profiles and dispersion measurements
+can be used to predict spiral arm winding numbers at this saturation point. A
+comparison between the observed and predicted winding numbers could test this
+hypothesis and also search for evidence of merger induced disk heating in
+nearby galaxies.",0004210v3
+2000-06-09,"R-modes in Neutron Stars with Crusts: Turbulent Saturation, Spin-down, and Crust Melting","Rossby waves (r-modes) have been suggested as a means to regulate the spin
+periods of young or accreting neutron stars, and also to produce observable
+gravitational wave radiation. R-modes involve primarily transverse,
+incompressive motions of the star's fluid core. However, neutron stars gain
+crusts early in their lives: therefore, r-modes also imply shear in the fluid
+beneath the crust. We examine the criterion for this shear layer to become
+turbulent, and derive the rate of dissipation in the turbulent regime. Unlike
+dissipation from a viscous boundary layer, turbulent energy loss is nonlinear
+in mode energy and can therefore cause the mode to saturate at amplitudes
+typically much less than unity. This energy loss also reappears as heat below
+the crust. We study the possibility of crust melting as well as its
+implications for the spin evolution of low-mass X-ray binaries. Lastly, we
+identify some universal features of the spin evolution that may have
+observational consequences.",0006123v1
+2002-01-28,Rotation and Activity in Mid-M to L Dwarfs,"We analyze rotation velocities and chromospheric (H-alpha) activity, derived
+from multi-year, high-resolution spectra, in 56 mid-M to L dwarfs. Rotational
+velocities are found to increase from mid-M to L. This is consistent with a
+lengthening of spin-down timescale with later type, though in the L types the
+trend may also be a function of stellar age. From M5 to M8.5, a saturation-type
+rotation-activity relation is seen, similar to that in earlier types. However,
+the saturation velocity in our case is much higher, at about 12 km/s. A sharp
+drop in activity is observed at about M9, with later types showing little or no
+H-alpha emission, in spite of rapid rotation. This may be due to the very high
+resistivities in the predominantly neutral atmospheres of these cool objects.",0201455v1
+2002-01-31,Elemental Abundances in Stellar Coronae with XMM-Newton,"The XMM-Newton Reflection Grating Spectrometer Team has obtained observations
+ofa large number of coronal sources of various activity levels, ages, and
+spectraltypes. In particular, X-ray bright RS CVn binary systems display
+saturated coronal emission with spectral lines characteristic of hot (10-30 MK)
+plasma. Furthermore, we have obtained XMM-Newton data from young solar analogs
+both within and outside the X-ray saturation regime. We have simultaneously
+analyzed the EPIC MOS and RGS data from these objects and have obtained coronal
+abundances of various elements (e.g., C, N, O, Ne, Mg, Si, Fe). We show that
+there is evidence for a transition from an Inverse First Ionization Potential
+(FIP) effect in most active stars to a ``normal'' solar-like FIP effect in less
+active stars. We discuss this result with regard to photospheric abundances.",0201530v1
+2002-08-20,Saturation of the corotation resonance in a gaseous disk,"We determine the torque exerted in a steady state by an external potential on
+a three-dimensional gaseous disk at a non-coorbital corotation resonance. Our
+model accounts for the feedback of the torque on the surface density and
+vorticity in the corotation region, and assumes that the disk has a barotropic
+equation of state and a nonzero effective viscosity. The ratio of the torque to
+the value given by the formula of Goldreich & Tremaine depends essentially on a
+single dimensionless parameter, which quantifies the extent to which the
+resonance is saturated. We discuss the implications for the eccentricity
+evolution of young planets.",0208363v2
+2003-04-11,Mechanisms of the Vertical Secular Heating of a Stellar Disk,"We investigate the nonlinear growth stages of bending instability in stellar
+disks with exponential radial density profiles.We found that the unstable modes
+are global (the wavelengths are larger than the disk scale lengths) and that
+the instability saturation level is much higher than that following from a
+linear criterion. The instability saturation time scales are of the order of
+one billion years or more. For this reason, the bending instability can play an
+important role in the secular heating of a stellar disk in the $z$ direction.
+In an extensive series of numerical $N$-body simulations with a high spatial
+resolution, we were able to scan in detail the space of key parameters (the
+initial disk thickness $z_0$, the Toomre parameter $Q$, and the ratio of dark
+halo mass to disk mass $M_{\rm h} / M_{\rm d}$). We revealed three distinct
+mechanisms of disk heating in the $z$ direction: bending instability of the
+entire disk, bending instability of the bar, and heating on vertical
+inhomogeneities in the distribution of stellar matter.",0304215v1
+2004-07-27,Stability of hydrodynamical relativistic planar jets. I. Linear evolution and saturation of Kelvin-Helmholtz modes,"The effects of relativistic dynamics and thermodynamics in the development of
+Kelvin-Helmholtz instabilities in planar, relativistic jets along the early
+phases (namely linear and saturation phases) of evolution has been studied by a
+combination of linear stability analysis and high-resolution numerical
+simulations for the most unstable first reflection modes in the temporal
+approach. Three different values of the jet Lorentz factor (5, 10 and 20) and a
+few different values of specific internal energy of the jet matter (from 0.08
+to $60.0 c^2$) have been considered. Figures illustrating the evolution of the
+perturbations are also shown.",0407548v1
+2005-07-08,Hot Accretion With Saturated Conduction,"Observations of the hot gas surrounding Sgr A* and a few other nearby
+galactic nuclei imply electron and proton mean free paths comparable to the gas
+capture radius: hot accretion likely proceeds under weakly-collisional
+conditions in these systems. As a result, thermal conduction, rather than
+convection, may be important on all scales and affect the global flow
+properties. The self-similar ADAF solution of Narayan & Yi (1994) is
+generalized to include a saturated form of thermal conduction, as is
+appropriate for the weakly-collisional regime of interest. Conduction provides
+extra heating and yet it reduces the free-free radiative efficiency of the
+accretion flow (by potentially large factors). These idealized solutions
+suggest that thermal conduction may be an important physical ingredient to
+understand hot accretion onto dim accreting black holes. Conduction could also
+play a role in reducing the rate at which black holes capture ambient gas and
+in providing an evaporation mechanism for an underlying cold thin disk.",0507189v1
+2005-12-22,Air Shower Properties with the Gluon Saturation Model BBL,"The hadronic interaction model BBL implements the ideas of gluon saturation
+due to large densities. When approaching the black body limit at high energies,
+leading partons acquire large transverse momenta which breaks up their
+coherence. This leads to a suppression of forward scattering, and is therefore
+important for air showers. We discuss some general aspects of this new approach
+and their influence on air shower properties as seen by fluorescence and
+surface detectors: The position of the shower maximum is reduced due to
+stronger absorption in the atmosphere. The lateral distribution functions
+become flatter for the same reason. Muons are produced abundantly due to high
+multiplicities in the mid-rapidity region. The response of water Cherenkov
+detectors and comparisons to other interaction models are shown.",0512564v1
+2006-10-18,A Local Model for Angular Momentum Transport in Accretion Disks Driven by the Magnetorotational Instability,"We develop a local model for the exponential growth and saturation of the
+Reynolds and Maxwell stresses in turbulent flows driven by the
+magnetorotational instability. We first derive equations that describe the
+effects of the instability on the growth and pumping of the stresses. We
+highlight the relevance of a new type of correlations that couples the
+dynamical evolution of the Reynolds and Maxwell stresses and plays a key role
+in developing and sustaining the magnetorotational turbulence. We then
+supplement these equations with a phenomenological description of the triple
+correlations that lead to a saturated turbulent state. We show that the
+steady-state limit of the model describes successfully the correlations among
+stresses found in numerical simulations of shearing boxes.",0610565v1
+2006-11-09,Nonsaturated Holographic Dark Energy,"It has been well established by today that the concept of holographic dark
+energy (HDE) does entail a serious candidate for the dark energy of the
+universe. Here we deal with models where the holographic bound for dark energy
+is not saturated for a large portion of the history of the universe. This is
+particularly compelling when the IR cutoff is set by the Hubble scale, since
+otherwise a transition from a decelerated to an accelerated era cannot be
+obtained for a spatially flat universe. We demonstrate by three generic but
+disparate dynamical models, two of them containing a variable Newton constant,
+that transition between the two eras is always obtained for the IR cutoff in
+the form of the Hubble scale and the nonsaturated HDE. We also give arguments
+of why such a choice for the dark energy is more consistent and favored over
+the widely accepted saturated form.",0611299v2
+1993-06-15,Locally Frozen Defects in Random Sequential Adsorption with Diffusional Relaxation,"Random sequential adsorption with diffusional relaxation, of two by two
+square objects on the two-dimensional square lattice is studied by Monte Carlo
+computer simulation. Asymptotically for large lattice sizes, diffusional
+relaxation allows the deposition process to reach full coverage. The coverage
+approaches the full occupation value, 1, as a power-law with convergence
+exponent near 1/2. For a periodic lattice of finite (even) size $L$, the final
+state is a frozen random rectangular grid of domain walls connecting
+single-site defects. The domain sizes saturate at L**0.8. Prior to saturation,
+i.e., asymptotically for infinite lattice, the domain growth is power-law with
+growth exponent near, or possibly somewhat smaller than, 1/2.",9306034v1
+1996-10-08,Characterization of the Noise in Secondary Ion Mass Spectrometry Depth Profiles,"The noise in the depth profiles of secondary ion mass spectrometry (SIMS) is
+studied using different samples under various experimental conditions. Despite
+the noise contributions from various parts of the dynamic SIMS process, its
+overall character agrees very well with the Poissonian rather than the Gaussian
+distribution in all circumstances. The Poissonian relation between the measured
+mean-square error (MSE) and mean can be used to describe our data in the range
+of four orders. The departure from this relation at high counts is analyzed and
+found to be due to the saturation of the channeltron used. Once saturated, the
+detector was found to exhibit hysteresis between rising and falling input flux
+and output counts.",9610061v1
+1997-07-28,Lattice dependence of saturated ferromagnetism in the Hubbard model,"We investigate the instability of the saturated ferromagnetic ground state
+(Nagaoka state) in the Hubbard model on various lattices in dimensions d=2 and
+d=3. A variational resolvent approach is developed for the Nagaoka instability
+both for U = infinity and for U < infinity which can easily be evaluated in the
+thermodynamic limit on all common lattices. Our results significantly improve
+former variational bounds for a possible Nagaoka regime in the ground state
+phase diagram of the Hubbard model. We show that a pronounced particle-hole
+asymmetry in the density of states and a diverging density of states at the
+lower band edge are the most important features in order to stabilize Nagaoka
+ferromagnetism, particularly in the low density limit.",9707286v2
+1998-04-28,Macroscopic Equations of Motion for Two Phase Flow in Porous Media,"The established macroscopic equations of motion for two phase immiscible
+displacement in porous media are known to be physically incomplete because they
+do not contain the surface tension and surface areas governing capillary
+phenomena. Therefore a more general system of macroscopic equations is derived
+here which incorporates the spatiotemporal variation of interfacial energies.
+These equations are based on the theory of mixtures in macroscopic continuum
+mechanics. They include wetting phenomena through surface tensions instead of
+the traditional use of capillary pressure functions. Relative permeabilities
+can be identified in this approach which exhibit a complex dependence on the
+state variables. A capillary pressure function can be identified in equilibrium
+which shows the qualitative saturation dependence known from experiment. In
+addition the new equations allow to describe the spatiotemporal changes of
+residual saturations during immiscible displacement.",9804299v1
+1998-10-28,Evidence for saturation of channel transmission from conductance fluctuations in atomic-size point contacts,"The conductance of atomic size contacts has a small, random, voltage
+dependent component analogous to conductance fluctuations observed in diffusive
+wires (UCF). A new effect is observed in gold contacts, consisting of a marked
+suppression of these fluctuations when the conductance of the contact is close
+to integer multiples of the conductance quantum. Using a model based on the
+Landauer-Buettiker formalism we interpret this effect as evidence that the
+conductance tends to be built up from fully transmitted (i.e., saturated)
+channels plus a single, which is partially transmitted.",9810384v2
+1999-11-05,Hierarchical model for the scale-dependent velocity of seismic waves,"Elastic waves of short wavelength propagating through the upper layer of the
+Earth appear to move faster at large separations of source and receiver than at
+short separations. This scale dependent velocity is a manifestation of Fermat's
+principle of least time in a medium with random velocity fluctuations. Existing
+perturbation theories predict a linear increase of the velocity shift with
+increasing separation, and cannot describe the saturation of the velocity shift
+at large separations that is seen in computer simulations. Here we show that
+this long-standing problem in seismology can be solved using a model developed
+originally in the context of polymer physics. We find that the saturation
+velocity scales with the four-third power of the root-mean-square amplitude of
+the velocity fluctuations, in good agreement with the computer simulations.",9911075v1
+1999-12-08,Comparison of energy and phase relaxation in metallic wires,"We have measured the phase coherence time, $\tau_{\phi},$ in long, narrow
+wires of Au, Ag, and Cu, over the temperature range 40 mK-6 K. In the Cu and Au
+wires, $\tau_{\phi}$ saturates at low temperature. In the Ag wire,
+$\tau_{\phi}$ continues to increase down to the lowest temperatures measured;
+moreover, its temperature dependence below about 1 K is consistent with
+theoretical predictions of Altshuler, Aronov and Khmelnitskii published in
+1982. These results cast doubt on recent assertions that saturation of
+$\tau_{\phi}$ at low temperature is a universal phenomenon in metal wires. We
+compare these results with those of recent experiments on energy relaxation in
+similar metallic wires. The results of the two experiments are strongly
+correlated, suggesting that a single (unknown) mechanism is the cause of the
+enhanced phase and energy relaxation observed in some samples.",9912137v1
+2000-01-29,Tractable non-local correlation density functionals for flat surfaces and slabs,"A systematic approach for the construction of a density functional for van
+der Waals interactions that also accounts for saturation effects is described,
+i.e. one that is applicable at short distances. A very efficient method to
+calculate the resulting expressions in the case of flat surfaces, a method
+leading to an order reduction in computational complexity, is presented.
+Results for the interaction of two parallel jellium slabs are shown to agree
+with those of a recent RPA calculation (J.F. Dobson and J. Wang, Phys. Rev.
+Lett. 82, 2123 1999). The method is easy to use; its input consists of the
+electron density of the system, and we show that it can be successfully
+approximated by the electron densities of the interacting fragments. Results
+for the surface correlation energy of jellium compare very well with those of
+other studies. The correlation-interaction energy between two parallel jellia
+is calculated for all separations d, and substantial saturation effects are
+predicted.",0001429v1
+2000-02-15,Charge-Reversal Instability in Mixed Bilayer Vesicles,"Bilayer vesicles form readily from mixtures of charged and neutral
+surfactants. When such a mixed vesicle binds an oppositely-charged object, its
+membrane partially demixes: the adhesion zone recruits more charged surfactants
+from the rest of the membrane. Given an unlimited supply of adhering objects
+one might expect the vesicle to remain attractive until it was completely
+covered. Contrary to this expectation, we show that a vesicle can instead
+exhibit {\it adhesion saturation,} partitioning spontaneously into an
+attractive zone with definite area fraction, and a repulsive zone. The latter
+zone rejects additional incoming objects because counterions on the interior of
+the vesicle migrate there, effectively reversing the membrane's charge. The
+effect is strongest at high surface charge densities, low ionic strength, and
+with thin, impermeable membranes. Adhesion saturation in such a situation has
+recently been observed experimentally [H. Aranda-Espinoza {\it et al.}, {\sl
+Science} {\bf285} 394--397 (1999)].",0002230v1
+2001-05-26,Discrete saturation thickness and anomalous potential height of native ultrathin aluminum oxide tunnel barriers,"We have investigated planar metal - insulator - metal tunnel junctions with
+aluminum oxide as dielectricum. These oxide barriers were grown on an aluminum
+electrode in pure oxygen at room temperature till saturation. We observed
+discrete barrier widths separated by \Delta s \approx 0.38 nm, corresponding to
+the addition of one layer of oxygen atoms. The minimum thickness of s_0 \approx
+0.54 nm is due to a double layer of oxygen. We found a strong and systematic
+dependence of the barrier height \Phi_0 on the thickness s like \Phi_0 \approx
+2.5 eV / s^2(nm), which nearly coincides with the kinetic electron energy E =
+h^2/2ms^2 for which the deBroglie wavelength matches the width of the barrier.",0105511v1
+2002-03-19,Persistent Non-ergodic Fluctuations in Mesoscopic Insulators,"We give a detailed and rigorous picture of the mesoscopic conductance
+fluctuations in the deep insulating regime (DIR) within the Nguyen, Spivak and
+Shklovskii model including spin-orbit coupling (SO). Without SO, we find that
+fluctuations of the log-conductance are persistent above a saturation field $%
+B_s$, where one has that the log-conductance is approximately a stationary
+random process. In contrast, in the SO case the saturation field $B_s$ is
+negligible and the stationarity is well realized. We find non-vanishing
+disorder fluctuations of the field average of the log-conductance as a
+quantitative measure of the lack of ergodicity in the mean square sense. As a
+consequence the commonly used criterion to test the ergodicity based on the
+equivalence of the variance in disorder and the variance in the field is not
+fulfilled. Using the replica approach, we derive the weak localization analogs
+of the `cooperon and diffuson.",0203380v1
+2002-05-09,Many-body and correlation effects on parametric polariton amplificazion in semiconductor microcavities,"Very efficient amplification of light-matter waves (polaritons), that are a
+superposition of cavity photons and excitons [1] has recently been
+reported[2-11]. The optical gain curve versus the pump power shows a threshold
+and then saturates to a maximum value[7,11]. Very recently it has been shown
+that this limit-value of gain can be greatly enhanced by increasing the
+exciton-photon coupling rate, allowing to approach room temperature
+operation11. This anomalous enhancement is in contrast with results from
+present theories[12,13] describing the process. Here we clarify the mechanisms
+determining gain saturation and explain the observed giant amplification. We
+show that this enhancement origins from the non-instantaneous nature of
+exciton-exciton collisions in semiconductors[14] due to many-body correlations.
+We find that the exciton-photon coupling is able to alter the exciton dynamics
+during collisions and hence to modify the coupling mechanism at the basis of
+amplification. These results give precise indications to favour room
+temperature operation for the realization of all-optical microscopic switches
+and amplifiers and demonstrate that exciton-exciton collisions in
+semiconductors can be controlled and engineered.",0205199v1
+2002-05-21,Is weak temperature dependence of electron dephasing possible?,"The first-principle theory of electron dephasing by disorder-induced two
+state fluctuators is developed. There exist two mechanisms of dephasing. First,
+dephasing occurs due to direct transitions between the defect levels caused by
+inelastic electron-defect scattering. The second mechanism is due to violation
+of the time reversal symmetry caused by time-dependent fluctuations of the
+scattering potential. These fluctuations originate from an interaction between
+the dynamic defects and conduction electrons forming a thermal bath. The first
+contribution to the dephasing rate saturates as temperature decreases. The
+second contribution does not saturate, although its temperature dependence is
+rather weak, $\propto T^{1/3}$. The quantitative estimates based on the
+experimental data show that these mechanisms considered can explain the weak
+temperature dependence of the dephasing rate in some temperature interval.
+However, below some temperature dependent on the model of dynamic defects the
+dephasing rate tends rapidly to zero. The relation to earlier studies of the
+dephasing caused by the dynamical defects is discussed.",0205438v1
+2002-07-02,Relaxation to steady states and dynamical exponents in deposition models,"Considering some deposition models with limited mobility, we show that the
+typical decay of the interface width to its saturation value is exponential,
+which defines the crossover or saturation time \tau. We present a method to
+calculate a characteristic time \tau_0 proportional to \tau and estimate the
+dynamical exponent z. In one dimensional substrates of lengths L <~ 2048, the
+method is applied to the Family model, the restricted solid-on-solid (RSOS)
+model and the ballistic deposition. Effective exponents z_L converge to
+asymptotic values consistent with the corresponding continuum theories. For the
+two-dimensional Family model, the expected dynamic scaling hypothesis suggests
+a particular definition of \tau_0 that leads to z=2, improving previous
+calculations based on data collapse methods. For the two-dimensional RSOS
+model, we obtain z ~ 1.6 and \alpha < 0.4, in agreement with recent large scale
+simulations.",0207088v1
+2002-08-02,Instability of quasi-liquid on the edges and vertices of snow crystals,"In this paper, we show theoretically that there exists quasi-liquid on the
+edges and vertices of snow crystals between -4C and -22C, while the basal and
+prism faces have no quasi-liquid layers. Investigating the macroscopic theory
+of quasi-liquid and applying to the edges and vertices of the crystal, we find
+that the quasi-liquid becomes unstable above the critical supersaturation
+point, which is above the water saturation point. The thickness of this
+unstable quasi-liquid layer continues growing indefinitely. We interpret this
+behavior as corresponding to continuous production and overflow onto
+neighboring faces in a real system. We hypothesize that the unstable growth of
+snow crystals originates from the edges and vertices, and it is due to the
+overflow of quasi-liquid from the edges and vertices onto the neighboring
+faces, which are rough and lack quasi-liquid. Our hypothesis accounts for the
+qualitative behavior of the relations between the morphological instability and
+the water saturation in the snow phase diagram.",0208036v1
+2002-12-20,Capillary forces in the acoustics of patchy-saturated porous media,"A linearized theory of the acoustics of porous elastic formations, such as
+rocks, saturated with two different viscous fluids is generalized to take into
+account a pressure discontinuity across the fluid boundaries. The latter can
+arise due to the surface tension of the membrane separating the fluids. We show
+that the frequency-dependent bulk modulus $\tilde{K}(\omega)$ for wave lengths
+longer than the characteristic structural dimensions of the fluid patches has a
+similar analytic behavior as in the case of a vanishing membrane stiffness and
+depends on the same parameters of the fluid-distribution topology. The effect
+of the capillary stiffness can be accounted by renormalizing the coefficients
+of the leading terms in the low-frequency asymptotic of $\tilde{K}(\omega)$.",0212534v2
+2003-03-31,The droplet evaporation/condensation transition in a finite volume,"A fluid in the NVT ensemble at T less than the critical temperature T_c and
+rho = N/V somewhat in excess of rho_coex (density of the saturated gas in the
+gas-liquid transition) is considered. For V->infinity, a macroscopic liquid
+droplet coexists with surrounding saturated gas according to the lever rule.
+For finite V, droplets can only exist if they exceed a minimum size. A
+(rounded) first order transition of the system occurs when the droplet
+evaporates into the supersaturated gas.Simulation evidence for this transition
+is given for a Lennard-Jones model and interpreted by a phenomenological
+theory. At the transition, the chemical potential difference mu_t-mu_coex
+scales like L^(-d/(d+1)) for a cubic volume V=L^d in d dimensions, as
+L->infinity.",0303642v1
+2003-06-04,The Absence Of Saturation Of The Level Number Variance In A Rectangular Box,"The variance of the number of levels in an energy interval around a level
+with large quantum numbers (semiclassical quantization) is studied for a
+particle in a rectangular box. Sampling involves changing the ratio of the
+rectangle's sides while keeping the area constant. For sufficiently narrow
+intervals, one finds the usual linear growth with the width of the interval.
+For wider intervals, the variance undergoes large, non-decaying oscillations
+around what is expected to be the saturation value. These oscillations can be
+explained as a superposition of just a few harmonics that correspond to the
+shortest periodic orbits in the rectangle. The analytical and numerical results
+are in excellent agreement.",0306110v1
+2003-07-01,Efficient nonlinear room-temperature spin injection from ferromagnets into semiconductors through a modified Schottky barrier,"We suggest a consistent microscopic theory of spin injection from a
+ferromagnet (FM) into a semiconductor (S). It describes tunneling and emission
+of electrons through modified FM-S Schottky barrier with an ultrathin heavily
+doped interfacial S layer . We calculate nonlinear spin-selective properties of
+such a reverse-biased FM-S junction, its nonlinear I-V characteristic, current
+saturation, and spin accumulation in S. We show that the spin polarization of
+current, spin density, and penetration length increase with the total current
+until saturation. We find conditions for most efficient spin injection, which
+are opposite to the results of previous works, since the present theory
+suggests using a lightly doped resistive semiconductor. It is shown that the
+maximal spin polarizations of current and electrons (spin accumulation) can
+approach 100% at room temperatures and low current density in a nondegenerate
+high-resistance semiconductor.",0307030v4
+2003-09-03,Intrusion and extrusion of water in hydrophobic mesopores,"We present experimental and theoretical results on intrusion-extrusion cycles
+of water in hydrophobic mesoporous materials, characterized by independent
+cylindrical pores. The intrusion, which takes place above the bulk saturation
+pressure, can be well described using a macroscopic capillary model. Once the
+material is saturated with water, extrusion takes place upon reduction of the
+externally applied pressure; Our results for the extrusion pressure can only be
+understood by assuming that the limiting extrusion mechanism is the nucleation
+of a vapour bubble inside the pores. A comparison of calculated and
+experimental nucleation pressures shows that a proper inclusion of line tension
+effects is necessary to account for the observed values of nucleation barriers.
+Negative line tensions of order $10^{-11} \mathrm{J.m}^{-1}$ are found for our
+system, in reasonable agreement with other experimental estimates of this
+quantity.",0309077v1
+2003-10-31,Statistical theory of high-gain free-electron laser saturation,"We propose a new approach, based on statistical mechanics, to predict the
+saturated state of a single-pass, high-gain free-electron laser (FEL). In
+analogy with the violent relaxation process in self-gravitating systems and in
+the Euler equation of 2D turbulence, the initial relaxation of the laser can be
+described by the statistical mechanics of an associated Vlasov equation. The
+Laser field intensity and the electron bunching parameter reach
+quasi-stationary values that are well fitted by a Vlasov stationary state if
+the number of electrons $N$ is sufficiently large. Finite $N$ effects
+(granularity) finally drive the system to Boltzmann-Gibbs statistical
+equilibrium, but this occurs on times that are unphysical (i.e. excessively
+long undulators). All theoretical predictions are successfully tested in finite
+$N$ numerical experiments. Our results may provide important hints to the
+optimization of the length of the FEL undulator.",0310754v2
+2004-08-19,Charge dynamics of Ca_{2-x}Na_{x}CuO_{2}Cl_{2} as a correlated electron system with the ideal tetragonal lattice,"We report the reflectivity and the resistivity measurement of
+Ca_{2-x}Na_{x}CuO_{2}Cl_{2} (CNCOC), which has a single-CuO2-plane lattice with
+no orthorhombic distortion. The doping dependence of the in-plane optical
+conductivity spectra for CNCOC is qualitatively the same to those of other
+cuprates, but a slight difference between CNCOC and LSCO, i.e., the absence of
+the 1.5 eV peak in CNCOC, can be attributed to the smaller charge-stripe
+instability in CNCOC. The temperature dependence of the optical onductivity
+spectra of CNCOC has been analyzed both by the two-component model
+(Drude+Lorentzian) and by the one-component model (extended-Drude analysis).
+The latter analysis gives a universal trend of the scattering rate Gamma(omega)
+with doping. It was also found that Gamma(omega) shows a saturation behavior at
+high frequencies, whose origin is the same as that of resistivity saturation at
+high temperatures.",0408423v1
+2004-08-26,High-pressure phase relations of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+δ}$ single crystals,"We have investigated the pressure dependence of the superconducting
+transition temperature $T_{c}$ up to 18 GPa of
+Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ single crystals ranging from the
+highly underdoped through the nearly optimally doped to the highly overdoped
+level. For all three samples studied, $T_{c}$ is found to increase initially
+and then saturate at a critical pressure $P_{c}$ but decrease modestly with
+further compression. Oxygen doping tends to reduce the increase in $T_{c}$ and
+$P_{c}$. A new high-pressure phase diagram between the saturated $T_{c}$ and
+$P_{c}$ is then obtained. Theoretical interpretation is given by using the
+competition between the hole carrier density and pairing interaction strength
+based on the high-pressure transport data of the resistivity and Hall
+coefficient in this system.",0408587v2
+2004-10-24,In situ observation of the generation and annealing kinetics of E' centers induced in amorphous SiO2 by 4.7eV laser irradiation,"The kinetics of E' centers induced in silica by 4.7eV laser irradiation was
+investigated observing in situ their optical absorption band at 5.8 eV. After
+exposure the defects decay due to reaction with diffusing molecular hydrogen of
+radiolytic origin. Hydrogen-related annealing is active also during exposure
+and competes with the photo-induced generation of the centers until a
+saturation is reached. The concentrations of E' and H2 at saturation are
+proportional, so indicating that the UV-induced generation processes of the two
+species are correlated. These results are consistent with a model in which E'
+and hydrogen are generated from a common precursor Si-H.",0410608v2
+2005-01-21,Two-dimensional metal-insulator transition and in-plane magnetoresistance in a high mobility strained Si quantum well,"The apparent metal-insulator transition is observed in a high quality
+two-dimensional electron system (2DES) in the strained Si quantum well of a
+Si/Si_{1-x}Ge_x heterostructure with mobility \mu=1.9 x 10^5 cm^2/Vs at density
+n=1.45 x 10^{11} cm^{-2}. The critical density, at which the thermal
+coefficient of low T resistivity changes sign, is ~ 0.32 x 10^{11} cm^{-2}, so
+far the lowest observed in the Si 2D systems. In-plane magnetoresistance study
+was carried out in the higher density range where the 2DES shows the
+metallic-like behavior. It is observed that the in-plane magnetoresistance
+first increases as ~ B_{ip}^2 and then saturates to a finite value \rho(B_c)
+for B_{ip} > B_c. The full spin-polarization field B_c decreases monotonically
+with n but appears to saturate to a finite value as n approaches zero.
+Furthermore, \rho(B_c)/\rho(0) ~ 1.8 for all the densities ranging from 0.35 x
+10^{11} to 1.45 x 10^{11} cm^{-2} and, when plotted versus B_{ip}/B_c,
+collapses onto a single curve.",0501532v2
+2005-01-25,Pattern scaling in the axial segregation of granular materials in a rotating tube,"Granular mixtures frequently segregate by grain size along the axis of
+partially-filled, horizontal, rotating tubes. When segregation approaches
+saturation at the surface, a well-defined pattern of bands with wavelength
+$\lambda$ emerges. The long-term dynamics of the pattern involves a much slower
+coarsening process. We characterized the initial saturated wavelength $\lambda$
+as a function of the diameter of the tube $D$ for a filling fraction of 30 %,
+for $1.9 {\rm cm} \leq D \leq 11.5 {\rm cm}$. We also studied the initial
+growth-rate of the bands as $D$ varies. We find that $\lambda/D$ is not
+constant, but rather increases rapidly for small $D$. The growth-rate of bands
+decreases with smaller $D$ and segregation is suppressed completely for
+sufficiently small $D$. These relatively simple features are not captured by
+any of the existing models of axial segregation.",0501606v1
+2005-02-13,Transport properties in correlated systems: An analytical model,"Several studies have so far investigated transport properties of strongly
+correlated systems. Interesting features of these materials are the lack of
+resistivity saturation well beyond the Mott-Ioffe-Regel limit and the scaling
+of the resistivity with the hole density in underdoped cuprates. Due to the
+strongly correlated nature of these materials, mainly numerical techniques have
+been employed. A key role in this regards is thought to be played by the
+continuous transfer of spectral weight from coherent to incoherent states. In
+this paper we employ a simple analytical expression for the electronic Green's
+function to evaluate both quasi-particle and transport properties in correlated
+systems. Our analytical approach permits to enlighten the specific role of the
+spectral transfer due to the correlation on different features. In particular
+we investigate the dependence of both quasi-particle and transport scattering
+rate on the correlation degree and the criterion for resistivity saturation.
+systems.",0502297v3
+2005-03-07,Zero temperature dynamics of Ising model on a densely connected small world network,"The zero temperature quenching dynamics of the ferromagnetic Ising model on a
+densely connected small world network is studied where long range bonds are
+added randomly with a finite probability $p$. We find that in contrast to the
+sparsely connected networks and random graph, there is no freezing and an
+initial random configuration of the spins reaches the equilibrium configuration
+within a very few Monte Carlo time steps in the thermodynamic limit for any $p
+\ne 0$. The residual energy and the number of spins flipped at any time shows
+an exponential relaxation to equilibrium. The persistence probability is also
+studied and it shows a saturation within a few time steps, the saturation value
+being 0.5 in the thermodynamic limit. These results are explained in the light
+of the topological properties of the network which is highly clustered and has
+a novel small world behaviour.",0503138v2
+2005-04-25,Ultrafast Quenching of Ferromagnetism in InMnAs Induced by Intense Laser Irradiation,"Time-resolved magneto-optical Kerr spectroscopy of ferromagnetic InMnAs
+reveals two distinct {\em demagnetization} processes -- fast ($<1$ ps) and slow
+($\sim$100 ps). Both components diminish with increasing temperature and are
+absent above the Curie temperature. The fast component rapidly grows with pump
+power and saturates at high fluences ($>10$ mJ/cm$^2$); the saturation value
+indicates a {\em complete quenching} of ferromagnetism on a sub-picosecond time
+scale. We attribute this fast dynamics to spin heating through $p$-$d$ exchange
+interaction between photo-carriers and Mn ions while the $\sim$100 ps component
+is interpreted as spin-lattice relaxation.",0504611v2
+2005-05-02,The Memory Effect in Electron Glasses,"We present a theory for the memory effect in electron glasses. In fast gate
+voltage sweeps it is manifested as a dip in the conductivity around the
+equilibration gate voltage. We show that this feature, also known as anomalous
+field effect, arises from the long-time persistence of correlations in the
+electronic configuration. We argue that the gate voltage at which the memory
+dip saturates is related to an instability caused by the injection of a
+critical number of excess carriers. This saturation threshold naturally
+increases with temperature. On the other hand, we argue that the gate voltage
+beyond which memory is erased, is temperature independent. Using standard
+percolation arguments, we calculate the anomalous field effect as a function of
+gate voltage, temperature, carrier density and disorder. Our results are
+consistent with experiments, and in particular, they reproduce the observed
+scaling of the width of the memory dip with various parameters.",0505021v3
+2005-05-13,Localized activity profiles and storage capacity of rate-based autoassociative networks,"We study analytically the effect of metrically structured connectivity on the
+behavior of autoassociative networks. We focus on three simple rate-based model
+neurons: threshold-linear, binary or smoothly saturating units. For a
+connectivity which is short range enough the threshold-linear network shows
+localized retrieval states. The saturating and binary models also exhibit
+spatially modulated retrieval states if the highest activity level that they
+can achieve is above the maximum activity of the units in the stored patterns.
+In the zero quenched noise limit, we derive an analytical formula for the
+critical value of the connectivity width below which one observes spatially
+non-uniform retrieval states. Localization reduces storage capacity, but only
+by a factor of 2~3. The approach that we present here is generic in the sense
+that there are no specific assumptions on the single unit input-output function
+nor on the exact connectivity structure.",0505349v1
+2005-10-24,Mobility in semiconducting carbon nanotubes at finite carrier density,"Carbon nanotube field-effect transistors operate over a wide range of
+electron or hole density, controlled by the gate voltage. Here we calculate the
+mobility in semiconducting nanotubes as a function of carrier density and
+electric field, for different tube diameters and temperature. The low-field
+mobility is a non-monotonic function of carrier density, and varies by as much
+as a factor of 4 at room temperature. At low density, with increasing field the
+drift velocity reaches a maximum and then exhibits negative differential
+mobility, due to the non-parabolicity of the bandstructure. At a critical
+density $\rho_c\sim$ 0.35-0.5 electrons/nm, the drift velocity saturates at
+around one third of the Fermi velocity. Above $\rho_c$, the velocity increases
+with field strength with no apparent saturation.",0510638v1
+2006-01-17,Statistical mechanics and Vlasov equation allow for a simplified hamiltonian description of single pass free electron laser saturated dynamics,"A reduced Hamiltonian formulation to reproduce the saturated regime of a
+single pass free electron laser, around perfect tuning, is here discussed.
+Asymptotically, $N\_m$ particles are found to organize in a dense cluster, that
+evolves as an individual massive unit. The remaining particles fill the
+surrounding uniform sea, spanning a finite portion of phase space,
+approximately delimited by the average momenta $\omega\_+$ and $\omega\_-$.
+These quantities enter the model as external parameters, which can be
+self-consistently determined within the proposed theoretical framework. To this
+aim, we make use of a statistical mechanics treatment of the Vlasov equation,
+that governs the initial amplification process. Simulations of the reduced
+dynamics are shown to successfully capture the oscillating regime observed
+within the original $N$-body picture.",0601362v1
+2006-03-17,Low velocity quantum reflection of Bose-Einstein condensates,"We studied quantum reflection of Bose-Einstein condensates at normal
+incidence on a square array of silicon pillars. For incident velocities of
+2.5-26 mm/s observations agreed with theoretical predictions that the
+Casimir-Polder potential of a reduced density surface would reflect slow atoms
+with much higher probability. At low velocities (0.5-2.5 mm/s), we observed
+that the reflection probability saturated around 60% rather than increasing
+towards unity. We present a simple model which explains this reduced
+reflectivity as resulting from the combined effects of the Casimir-Polder plus
+mean field potential and predicts the observed saturation. Furthermore, at low
+incident velocities, the reflected condensates show collective excitations.",0603463v1
+2006-03-20,Dynamic fluctuations of elastic lines in random environments,"We study the fluctuations of the two-time dependent global roughness of
+finite size elastic lines in a quenched random environment. We propose a
+scaling form for the roughness distribution function that accounts for the
+two-time, temperature, and size dependence. At high temperature and in the
+final stationary regime before saturation the fluctuations are as the ones of
+the Edwards-Wilkinson interface evolving from typical initial conditions. We
+analyze the variation of the scaling function within the aging regime and with
+the distance from saturation. We speculate on the relevance of our results to
+describe the fluctuations of other non-equilibrium systems such as models at
+criticality.",0603503v2
+2006-04-12,Low-frequency Noise in Josephson Junctions for Superconducting Qubits,"We have studied low-frequency resistance fluctuations in shadow-evaporated
+Al/AlOx/Al tunnel junctions. Between 300 K and 5 K the spectral density follows
+a 1/f-law. Below 5 K, individual defects distort the 1/f-shape of the spectrum.
+The spectral density decreases linearly with temperature between 150 K and 1 K
+and saturates below 0.8 K. At 4.2 K, the spectral density is about two orders
+of magnitude lower than expected from a recent survey [D. J. Van Harlingen et
+al., Phys. Rev. B 70, 064510 (2004)]. Due to the saturation below 0.8 K the
+estimated qubit dephasing times at 100 mK are only about two times longer than
+calculated by Van Harlingen et al.",0604306v2
+2006-07-24,Saturated Hydrocarbons on Silicon: Quantifying Desorption with Scanning Tunneling Microscopy and Quantum Theory,"Electron stimulated desorption of cyclopentene from the Si(100)-2x1 surface
+is studied experimentally with cryogenic UHV STM and theoretically with
+transport, electronic structure, and dynamical calculations. Unexpectedly for a
+saturated hydrocarbon on silicon, desorption is observed at bias magnitudes as
+low as 2.5 V, albeit the desorption yields are a factor of 500 to 1000 lower
+than previously reported for unsaturated molecules on silicon. The low
+threshold voltage for desorption can be attributed to hybridization of the
+molecule with the silicon surface, which results in low-lying ionic resonances
+within 2-3 eV of the Fermi level. These resonances are long-lived, spatially
+localized and displaced in equilibrium with respect to the neutral state,
+resulting, upon excitation, in symmetric (positive ion) or asymmetric (negative
+ion) motion of the silicon dimer atoms. This study highlights the importance of
+nuclear dynamics in silicon-based molecular electronics and suggests new
+guidelines for the control of such dynamics.",0607621v2
+2006-10-05,Carrier transport in 2D graphene layers,"Carrier transport in gated 2D graphene monolayers is theoretically considered
+in the presence of scattering by random charged impurity centers with density
+$n_i$. Excellent quantitative agreement is obtained (for carrier density $n >
+10^{12} \rm{cm}^{-2}$) with existing experimental data (Ref.
+\onlinecite{kn:novoselov2004, kn:novoselov2005, kn:zhang2005, kn:kim2006,
+kn:fuhrer2006}). The conductivity scales linearly with $n/n_i$ in the theory,
+and shows extremely weak temperature dependence. The experimentally observed
+asymmetry between electron and hole conductivities is explained by the
+asymmetry in the charged impurity configuration in the presence of the gate
+voltage, while the high-density saturation of conductivity for the highest
+mobility samples is explained as a crossover between the long-range and the
+point scattering dominated regimes. We argue that the experimentally observed
+saturation of conductivity at low density arises from the charged impurity
+induced inhomogeneity in the graphene carrier density which becomes severe for
+$n \lesssim n_i \sim 10^{12} \rm{cm}^{-2}$.",0610157v2
+2006-10-27,Optical response of high-$T_c$ cuprates: possible role of scattering rate saturation and in-plane anisotropy,"We present a generalized Drude analysis of the in-plane optical conductivity
+$\sigma_{ab}$($T$,$\omega$) in cuprates taking into account the effects of
+in-plane anisotropy. A simple ansatz for the scattering rate
+$\Gamma$($T$,$\omega$), that includes anisotropy, a quadratic frequency
+dependence and saturation at the Mott-Ioffe-Regel limit, is able to reproduce
+recent normal state data on an optimally doped cuprate over a wide frequency
+range. We highlight the potential importance of including anisotropy in the
+full expression for $\sigma_{ab}$($T$,$\omega$) and challenge previous
+determinations of $\Gamma$($\omega$) in which anisotropy was neglected and
+$\Gamma$($\omega$) was indicated to be strictly linear in frequency over a wide
+frequency range. Possible implications of our findings for understanding
+thermodynamic properties and self-energy effects in high-$T_c$ cuprates will
+also be discussed.",0610763v1
+2006-11-28,Intraband versus interband scattering rate effects in neutron irradiated MgB2,"One of the most important predictions of the two-gap theory of
+superconductivity concerns the role of interband scattering (IBS) by
+impurities. IBS is expected to decrease the critical temperature, Tc, of MgB2
+to a saturation value of about 20 K, where the two gaps merge to a single one.
+These predictions have been partially contradicted by experiments. In fact, Tc
+does not saturate in irradiated samples, but decreases linearly with residual
+resistivity and the merging of the gaps has been observed at a much lower Tc
+(11 K). In this paper we argue that, while at low level of disorder IBS is the
+leading mechanism that suppresses superconductivity, at higher disorder the
+experimental results can only be understood if the smearing of the density of
+states due to intraband electron lifetime effects is considered.",0611700v1
+2007-01-21,Dynamical control of electron spin coherence in a quantum dot,"We investigate the performance of dynamical decoupling methods at suppressing
+electron spin decoherence from a low-temperature nuclear spin reservoir in a
+quantum dot. The controlled dynamics is studied through exact numerical
+simulation, with emphasis on realistic pulse delays and long-time limit. Our
+results show that optimal performance for this system is attained by a periodic
+protocol exploiting concatenated design, with control rates substantially
+slower than expected from the upper spectral cutoff of the bath. For a known
+initial electron spin state, coherence can saturate at long times, signaling
+the creation of a stable ``spin-locked'' decoherence-free subspace. Analytical
+insight on saturation is obtained for a simple echo protocol, in good agreement
+with numerical results.",0701507v1
+2007-02-19,Wang-Landau Algorithm: a Theoretical Analysis of the Saturation of the Error,"In this work we present a theoretical analysis of the convergence of the
+Wang-Landau algorithm [Phys. Rev. Lett. 86, 2050 (2001)] which was introduced
+years ago to calculate the density of states in statistical models. We study
+the dynamical behavior of the error in the calculation of the density of
+states.We conclude that the source of the saturation of the error is due to the
+decreasing variations of the refinement parameter. To overcome this limitation,
+we present an analytical treatment in which the refinement parameter is scaled
+down as a power law instead of exponentially. An extension of the analysis to
+the N-fold way variation of the method is also discussed.",0702414v3
+2006-06-14,Rigid upper bounds for the angular momentum and centre of mass of non-singular asymptotically anti-de Sitter space-times,"We prove upper bounds on angular momentum and centre of mass in terms of the
+Hamiltonian mass and cosmological constant for non-singular asymptotically
+anti-de Sitter initial data sets satisfying the dominant energy condition. We
+work in all space-dimensions larger than or equal to three, and allow a large
+class of asymptotic backgrounds, with spherical and non-spherical conformal
+infinities; in the latter case, a spin-structure compatibility condition is
+imposed. We give a large class of non-trivial examples saturating the
+inequality. We analyse exhaustively the borderline case in space-time dimension
+four: for spherical cross-sections of Scri, equality together with completeness
+occurs only in anti-de Sitter space-time. On the other hand, in the toroidal
+case, regular non-trivial initial data sets saturating the bound exist.",0606064v2
+1992-12-22,Upper Bounds on the Lightest Higgs Boson Mass in General Supersymmetric Standard Models,"In a general supersymmetric standard model there is an upper bound $m_h$ on
+the tree level mass of the $CP=+1$ lightest Higgs boson which depends on the
+electroweak scale, $\tan \beta$ and the gauge and Yukawa couplings of the
+theory. When radiative corrections are included, the allowed region in the
+$(m_h,m_t)$ plane depends on the scale $\Lambda$, below which the theory
+remains perturbative, and the supersymmetry breaking scale $\Lambda_s$, that we
+fix to $1\ TeV$. In the minimal model with $\Lambda=10^{16}\ GeV$: $m_h<130\
+GeV$ and $m_t<185\ GeV$. In non-minimal models with an arbitrary number of
+gauge singlets and $\Lambda=10^{16}\ GeV$: $m_h<145\ GeV$ and $m_t<185\ GeV$.
+We also consider supersymmetric standard models with arbitrary Higgs sectors.
+For models whose couplings saturate the scale $\Lambda=10^{16}\ GeV$ we find
+$m_h<155\ GeV$ and $m_t<190\ GeV$. As one pushes the saturation scale $\Lambda$
+down to $\Lambda_s$, the bounds on $m_h$ and $m_t$ increase. For instance, in
+models with $\Lambda=10\ TeV$, the upper bounds for $m_h$ and $m_t$ go to $415\
+GeV$ and $385\ GeV$, respectively.",9212305v1
+1993-11-29,Unitarity Constraints for Transverse Gauge Bosons at LEP and Supercolliders,"Using asymptotic helicity amplitudes for Vector-Vector, Vector-Higgs and
+Higgs-Higgs scattering, we establish the unitarity constraints on the $SU(2)_c$
+conserving and $W_\mu$ depending interactions, which at sufficiently high
+energies may create strong forces among the transverse vector boson and Higgs
+states. We then derive upper bounds for the couplings of these interactions,
+which depend on the high energy scale where unitarity is saturated. If \eg\,
+unitarity is saturated at 1TeV, then $\lambda_W \lsim 0.12$ is obtained. The
+implied relations between the present and future LEP results, and the possible
+observations of strong effects at supercolliders, are also discussed",9311370v1
+1995-02-07,$γγ\to π^0 π^0$ and $η\to π^0 γγ$ at low energy within the Extended Nambu Jona-Lasinio Model,"Within the Extended Nambu Jona-Lasinio model, we calculate the $O(p^6)$
+counterterms entering the low-energy expansion of the $\gamma \gamma \to \pi^0
+\pi^0$ and the $\eta \to \pi^0 \gamma \gamma$ amplitudes in Chiral Perturbation
+Theory. For $\gamma \gamma \to \pi^0 \pi^0$ our results are compatible with
+both the experimental data and the two-loop calculation using meson resonance
+saturation. For the $\eta$ decay we find $\Gamma(\eta\to\pi^0
+\gamma\gamma)=0.58\pm 0.3$ eV which is in agreement with experiment within one
+standard deviation. We also give predictions for the neutral pion
+polarizabilities and compare them with the results obtained from resonance
+saturation.",9502243v1
+1995-03-07,$η\to π^{0} γγ$ and $γγ\to π^{0} π^{0}$ in $O(p^{6})$ chiral perturbation theory,"$\eta \rightarrow \pi^{0} \gamma \gamma$ and $\ggpipi$ are considered in
+$O(p^{6})$ chiral perturbation theory. In addition to the usual $\rho,\omega$
+contributions, there are two $O(p^{6})$ operators (${\cal L}_{6,m}$) arising
+from explicit chiral symmetry breaking. Since only one of the two operators
+contributes to $\etapigg$, the coefficient of this operator ($\equiv d_3$) can
+be determined in two ways : (i) from the measured decay rate of $\eta
+\rightarrow \pi^{0} \gamma \gamma$, and (ii) by assuming the resonance
+saturations of the low energy coefficients in the $O(p^{6})$ chiral lagrangian.
+We find that two methods lead to vastly different values of $d_3$, which would
+indicate that either the measured decay rate for $\eta \rightarrow \pi^{0}
+\gamma \gamma$ is too large by a factor of $2 \sim 3$, or the resonance
+saturation assumptions do not work for $d_3$.",9503253v1
+1995-07-04,Baby Skyrmion Strings,"We provide analytical and numerical evidence of the existence of classically
+stable, string-like configurations in a 2+1 dimensional analog of the Skyrme
+model. The model contains a conserved topological charge usually called the
+baryon number. Our strings are non-topological solitons which have a constant
+baryon number per unit length. The energy per length containing one baryon is,
+however, less than the energy of an isolated baryon (radially symmetric ``baby
+Skyrmion"") in a region of the parameter space, which suggests a degree of
+stability for our configurations. In a limiting case, our configuration
+saturates a Bogomolnyi-type bound and is degenerate in energy per baryon with
+the baby Skyrmion. In another limiting case, the energies are still degenerate
+but do not saturate the corresponding Bogomolnyi-type bound. Nonetheless, we
+expect the string to be stable here. Both limiting cases are solvable
+analytically.",9507223v1
+1997-09-18,Four-quark Operators Relevant to B Meson Lifetimes from QCD Sum Rules,"At the order of 1/m_b^3, the B meson lifetimes are controlled by the hadronic
+matrix elements of some four-quark operators. The nonfactorizable magnitudes of
+these four-quark operator matrix elements are analyzed by QCD sum rules in the
+framework of heavy quark effective theory. The vacuum saturation for
+color-singlet four-quark operators is justified at hadronic scale, and the
+nonfactorizable effect is at a few percent level. However for color-octet
+four-quark operators, the vacuum saturation is violated sizably that the
+nonfactorizable effect cannot be neglected for the B meson lifetimes. The
+implication to the extraction of some of the parameters from B decays is
+discussed. The B meson lifetime ratio is predicted as
+\tau(B^-)/\tau(B^0)=1.09\pm 0.02. However, the experimental result of the
+lifetime ratio \tau(\Lambda_b)/\tau(B^0) still cannot be explained.",9709386v2
+1997-10-29,On Chemical Equilibrium in Nuclear Collisions,"The data on average hadron multiplicities in central A+A collisions measured
+at CERN SPS are analysed with the ideal hadron gas model. It is shown that the
+full chemical equilibrium version of the model fails to describe the
+experimental results. The agreement of the data with the off-equilibrium
+version allowing for partial strangeness saturation is significantly better.
+The freeze-out temperature of about 180 MeV seems to be independent of the
+system size (from S+S to Pb+Pb) and in agreement with that extracted in e+e-,
+pp and p{\bar p} collisions. The strangeness suppression is discussed at both
+hadron and valence quark level. It is found that the hadronic strangeness
+saturation factor gamma_S increases from about 0.45 for pp interactions to
+about 0.7 for central A+A collisions with no significant change from S+S to
+Pb+Pb collisions. The quark strangeness suppression factor lambda_S is found to
+be about 0.2 for elementary collisions and about 0.4 for heavy ion collisions
+independently of collision energy and type of colliding system",9710529v1
+1998-11-19,Self-consistent treatment of the quark condensate and hadrons in nuclear matter,"We calculate the contribution of pions to the $\bar qq$-expectation value
+$\kappa(\rho)= <M|\bar qq|M>$ in symmetric nuclear matter. We employ exact pion
+propagator renormalized by nucleon-hole and isobar-hole excitations.
+Conventional straightforward calculation leads to the ""pion condensation"" at
+unrealistically small values of densities, causing even earlier restoration of
+chiral symmetry. This requires a self-consistent approach, consisting in using
+the models, which include direct dependence of in-medium mass values on
+$\kappa(\rho)$, e.g. the Nambu-Jona-Lasinio-model. We show, that in the
+self-consistent approach the $\rho$-dependence of the condensate is described
+by a smooth curve. The ""pion condensate "" point is removed to much higher
+values of density. The chiral restoration does not take place at least while
+$\rho<2.8\rho_0$ with $\rho_0$ being the saturation value. Validity of our
+approach is limited by possible accumulation of heavier baryons (delta isobars)
+in the ground state of nuclear matter. For the value of effective nucleon mass
+at the saturation density we found $m^*(\rho_0)=0.6m$, consistent with nowadays
+results of other authors.",9811391v1
+1999-05-03,Unitarization of the BFKL Pomeron on a Nucleus,"We analyze the evolution equation describing all multiple hard pomeron
+exchanges in a hadronic or nuclear structure functions that was proposed
+earlier. We construct a perturbation series providing us with an exact solution
+to the equation outside of the saturation region. The series demonstrates how
+at moderately high energies the corrections to the single BFKL pomeron exchange
+contribution which are due to the multiple pomeron exchanges start unitarizing
+total deep inelastic scattering cross section. We show that as energy increases
+the scattering cross section of the quark-antiquark pair of a fixed transverse
+separation on a hadron or nucleus given by the solution of our equation inside
+of the saturation region unitarizes and becomes independent of energy. The
+corresponding F_2 structure function also unitarizes and becomes linearly
+proportional to ln s. We also discuss possible applications of the developed
+technique to diffraction.",9905214v3
+1999-05-20,Finite energy chiral sum rules in QCD,"A set of well known chiral sum rules, expected to be valid in QCD, is
+confronted with experimental data on the vector and axial-vector hadronic
+spectral functions, obtained from tau-lepton decay by the ALEPH collaboration.
+The Das-Mathur-Okubo sum rule, the first and second Weinberg sum rules, and the
+electromagnetic pion mass difference sum rule are not well saturated by the
+data. Instead, a modified set of sum rules having additional weight factors
+that vanish at the end of the integration range on the real axis, is found to
+be precociously saturated by the data to a remarkable extent.",9905411v1
+1999-09-21,Scaling of transverse energies and multiplicities with atomic number and energy in ultrarelativistic nuclear collisions,"We compute how the initial energy density and produced gluon, quark and
+antiquark numbers scale with atomic number and beam energy in ultrarelativistic
+heavy ion collisions. The computation is based on the argument that the effect
+of all momentum scales can be estimated by performing the computation at one
+transverse momentum scale, the saturation momentum. The initial numbers are
+converted to final ones by assuming kinetic thermalisation and adiabatic
+expansion. The main emphasis of the study is at LHC and RHIC energies but it is
+observed that even at SPS energies this approach leads to results which are not
+unreasonable: what is usually described as a completely soft nonperturbative
+process can also be described in terms of gluons and quarks. The key element is
+the use of the saturation scale.",9909456v1
+1999-10-05,Combined analysis of the unitarity triangle and CP violation in the Standard Model,"We perform a combined analysis of the unitarity triangle and of the CP
+violating parameter epsilon'/epsilon using the most recent determination of the
+relevant experimental data and, whenever possible, hadronic matrix elements
+from lattice QCD. We discuss the role of the main non-perturbative parameters
+and make a comparison with other recent analyses. We use lattice results for
+the matrix element of Q_8 obtained without reference to the strange quark mass.
+Since a reliable lattice determination of the matrix element of Q_6 is still
+missing, the theoretical predictions for epsilon'/epsilon suffer from large
+uncertainties. By evaluating this matrix element with the vacuum-saturation
+approximation, we typically find as central value epsilon'/epsilon = (4 - 7) x
+10^(-4). We conclude that the experimental data suggest large deviation of the
+value of the matrix element of Q_6 from the vacuum-saturation approximation,
+possibly due to penguin contractions.",9910236v1
+2000-01-25,"A Pomeron Approach to Hadron-Nucleus and Nucleus-Nucleus ""Soft"" Interactions at High Energy","We formulate a generalization of the Glauber formalism for hadron-nucleus and
+nucleus-nucleus collisions based on the Pomeron approach to high energy
+interactions. Our treatment is based on two physical assumptions (i.e. two
+small parameters) : (i) that only sufficiently small distances contribute to
+the Pomeron structure; and (ii) the triple Pomeron vertex $G_{3P}/g_{P-N}
+  \ll 1$ (where $g_{P-N}$ is the Pomeron-nucleon vertex) is small. A systematic
+method is developed for calculating the total, elastic and diffractive
+dissociation cross sections as well as the survival probability of large
+rapidity gap processes and inclusive observables, both for hadron - nucleus and
+nucleus-nucleus collisions. Our approach suggests saturation of the density of
+the produced hadrons in nucleus-nucleus collisions, the value of the saturation
+density turns out to be large and depends on the number of nucleons in the
+lightest nucleus.",0001260v1
+2000-03-06,An estimate of higher twist at small x and low Q^2 based upon a saturation model,"We investigate the influence of higher twist corrections to deep inelastic
+structure functions in the low-$Q^2$ and small-$x$ HERA region. We review the
+general features of the lowest-order QCD diagrams which contribute to twist-4
+at small-$x$, in particular the sign structure of longitudinal and transverse
+structure functions which offers the possibility of strong cancellations in
+$F_2$. For a numerical analysis we perform a twist analysis of the saturation
+model which has been very successful both in describing the structure function
+and the DIS diffractive cross section at HERA. As the main conclusion, twist 4
+corrections are not small in $F_L$ or $F_T$ but in $F_2=F_L + F_T$ they almost
+cancel. This indicates the limitation on the use of the DGLAP formalism at
+small $x$ and $Q^2$. We point out that $F_L$ analysis needs a large twist-4
+correction. We also indicate the region of validity of the twist expansion.",0003042v4
+2000-04-05,Unitarity at small Bjorken x,"This paper presents a solution to the nonlinear small x ``projectile side''
+evolution equations as derived by Balitskii in 1996. The solution is based on
+functional Fokker-Planck methods. The fixed point at small x is explicitly
+calculated and all correlation functions in this limit are determined. They
+show clear saturation and unitarization properties. Scaling laws that hold
+during the saturation phase and throughout the whole course of the evolution
+are established. The corresponding Langevin equations are given as a basis for
+numerical simulations opening the field for future studies of dynamical issues
+of the evolution not analytically accessible. The methods used may be extended
+to the ``target side'' equations of Jalilian-Marian, Kovner, Leonidov and
+Weigert.",0004044v3
+2000-04-11,"Different Hagedorn temperatures for mesons and baryons from experimental mass spectra, compound hadrons, and combinatorial saturation","We analyze the light-flavor particle mass spectra and show that in the region
+up to ~1.8GeV the Hagedorn temperature for baryons is about 30% smaller than
+for mesons, reflecting the fact that the number of baryon states grows more
+rapidly with the mass. We also show that the spectra are well reproduced in a
+model where hadrons are compound objects of quanta, whose available number
+increases with mass. The rapid growth of number of hadronic states is a
+combinatorial effect. We also point out that an upper limit on the excitation
+energy of these quanta results in a maximum number of hadron states that can be
+formed. According to this combinatorial saturation, no more light-flavor hadron
+resonances exist above a certain mass.",0004104v2
+2000-08-28,From colored glass condensate to gluon plasma: equilibration in high energy heavy ion collisions,"The initial distribution of gluons at the very early times after a high
+energy heavy ion collision is described by the bulk scale $Q_s$ of gluon
+saturation in the nuclear wavefunction. The subsequent evolution of the system
+towards kinetic equilibrium is described by a non-linear Landau equation for
+the single particle distributions \cite{Mueller1,Mueller2}. In this paper, we
+solve this equation numerically for the idealized initial conditions proposed
+by Mueller, and study the evolution of the system to equilibrium. We discuss
+the sensitivity of our results on the dynamical screening of collinear
+divergences. In a particular model of dynamical screening, the convergence to
+the hydrodynamic limit is seen to be rapid relative to hydrodynamic time
+scales. The equilibration time, the initial temperature, and the chemical
+potential are shown to have a strong functional dependence on the initial gluon
+saturation scale $Q_s$.",0008294v1
+2000-11-20,Nonlinear Gluon Evolution in the Color Glass Condensate: I,"We consider a nonlinear evolution equation recently proposed to describe the
+small-$x$ hadronic physics in the regime of very high gluon density. This is a
+functional Fokker-Planck equation in terms of a classical random color source,
+which represents the color charge density of the partons with large $x$. In the
+saturation regime of interest, the coefficients of this equation must be known
+to all orders in the source strength. In this first paper of a series of two,
+we carefully derive the evolution equation, via a matching between classical
+and quantum correlations, and set up the framework for the exact background
+source calculation of its coefficients. We address and clarify many of the
+subtleties and ambiguities which have plagued past attempts at an explicit
+construction of this equation. We also introduce the physical interpretation of
+the saturation regime at small $x$ as a Color Glass Condensate. In the second
+paper we shall evaluate the expressions derived here, and compare them to known
+results in various limits.",0011241v1
+2001-01-11,Enhanced Minijet Production in $A-A$ Collisions from Gluons with Large Transverse Momenta,"We find supersaturation for the intrinsic gluon distribution of nuclei, i.e.
+the low $x$ unintegrated nuclear gluon distribution peaks at intermediate
+transverse momenta $k_t=Q_s$ and vanishes at zero $k_t$. Taking into account
+the intrinsic transverse momenta of the gluons and the saturation scale $p_s$
+of the produced gluons, we calculate the minijet cross section arising from
+gluon gluon scattering for RHIC energies. For central collisions at
+$\sqrt{s}=200GeV$ the saturation scale $p_s \approx 1.4$ GeV is larger due to
+intrinsic $k_t$ effects and increases with energy. Our theoretical results on
+charged particle multiplicity agree very well with the recent experimental data
+from RHIC.",0101115v2
+2001-02-08,Diffractive parton distributions from the saturation model,"We review diffractive deep inelastic scattering (DIS) in the light of the
+collinear factorization theorem. This theorem allows to define diffractive
+parton distributions in the leading twist approach. Due to its selective final
+states, diffractive DIS offers interesting insight into the form of the
+diffractive parton distributions which we explore with the help of the
+saturation model. We find Regge-like factorization with the correct energy
+dependence measured at HERA. A remarkable feature of diffractive DIS is the
+dominance of the twist-4 contribution for small diffractive masses. We quantify
+this effect and make a comparison with the data.",0102093v4
+2001-04-02,"Multiplicities and Transverse Energies in Central AA Collisions at RHIC and LHC from pQCD, Saturation and Hydrodynamics","We compute the particle multiplicities and transverse energies at central and
+nearly central AA collisions at RHIC and LHC. The initial state is computed
+from perturbative QCD supplemented by the conjecture of saturation of produced
+partons. The expansion stage is described in terms of hydrodynamics assuming
+longitudinal boost invariance and azimuthal symmetry. Transverse flow effects,
+a realistic list of hadrons and resonance decays are included. Comparison with
+the data of the multiplicities at $\sqrt s=56$ AGeV and 130 AGeV from RHIC is
+done and predictions for the full RHIC energy and LHC energy are made for the
+multiplicities and transverse energies. The reduction from the initially
+released minijet transverse energy to the $E_T$ in the final state is less than
+in the one-dimensional case but still dramatic: a factor of 2.7 at RHIC, and
+3.6 at the LHC.",0104010v2
+2001-04-03,Parton densities and dipole cross-sections at small x in large nuclei,"Unintegrated gluon densities in nuclei, dipole-nucleus cross-sections and
+quark densities are numerically investigated in the high-colour limit, with the
+scattering on a heavy nucleus exactly described by the sum of fan diagrams of
+BFKL pomerons. The initial condition for the evolution in rapidity is quickly
+forgotten, and the gluon density presents a ""supersaturation"" pattern, as
+previous studies indicated. Both dipole-nucleus cross-sections and quark
+densities present the expected saturation features. Identifying the position in
+transverse momentum $l$ of the maximum of the gluon distribution with the
+saturation momentum $Q_s(y,b)$, at large rapidities all distributions depend
+only on one variable $[l/Q_s(y,b)]$ or $[rQ_s(y,b)]$.",0104038v2
+2001-05-25,How Protons Shatter Colored Glass,"We consider the implications of the Color Glass Condensate for the central
+region of p+A collisions. We compute the k_t distribution of radiated gluons
+and their rapidity distribution dN/dy analytically, both in the perturbative
+regime and in the region between the two saturation momenta. We find an
+analytic expression for the number of produced gluons which is valid when the
+saturation momentum of the proton is much less than that of the nucleus. We
+discuss the scaling of the produced multiplicity with A. We show that the slope
+of the rapidity density dN/dy provides an experimental measure for the
+renormalization-group evolution of the color charge density of the Color Glass
+Condensate (CGC). We also argue that these results are easily generalized to
+collisions of nuclei of different A at central rapidity, or with the same A but
+at a rapidity far from the central region.",0105268v2
+2001-11-16,Determination of vector meson properties by matching resonance saturation to a constituent quark model,"The properties of mesonic resonances can be calculated in terms of the
+low-energy coefficients of chiral perturbation theory (chiPT) by extending
+unitarized chiPT to higher energies. On the other hand these low-energy
+coefficients can be calculated in two different models, namely (i) by assuming
+resonance saturation and (ii) within a constituent quark model. By matching the
+expressions of the two models combined with the results of unitarized chiPT and
+the Weinberg sum rules the properties of vector and axial-vector mesons can be
+calculated in the combined large-N_c and chiral limit.",0111204v2
+2002-03-26,Constraints on possible phase transitions above the nuclear saturation density,"We compare different models for hadronic and quark phases of cold baryon-rich
+matter in an attempt to find a deconfinement phase transition between them. For
+the hadronic phase we consider Walecka-type mean-field models which describe
+well the nuclear saturation properties. We also use the variational chain model
+which takes into account correlation effects. For the quark phase we consider
+the MIT bag model, the Nambu-Jona-Lasinio and the massive quasiparticle models.
+By comparing pressure as a function of baryon chemical potential we find that
+crossings of hadronic and quark branches are possible only in some exceptional
+cases while for most realistic parameter sets these branches do not cross at
+all. Moreover, the chiral phase transition, often discussed within the
+framework of QCD motivated models, lies in the region where the quark phases
+are unstable with respect to the hadronic phase. We discuss possible physical
+consequences of these findings.",0203241v1
+2002-06-03,A simple model for nuclear structure functions at small $x$ in the dipole picture,"A simple model for nuclear structure functions in the region of small x and
+small and moderate $Q^2$, is presented. It is a parameter-free extension, in
+the Glauber-Gribov approach to nuclear collisions, of a saturation model for
+the nucleon. A reasonable agreement with experimental data on ratios of nuclear
+structure functions is obtained. Nuclear effects in the
+longitudinal-to-transverse cross section ratios are found to be small.
+Predictions of the model for values of $x$ smaller than those available to
+present experiments are given. The unintegrated gluon distribution and the
+behaviour of the saturation scale which result from this model are shown and
+discussed.",0206017v2
+2002-07-03,Instantons and Saturation in the Colour Dipole Picture,"We pursue the intriguing possibility that larger-size instantons build up
+diffractive scattering, with the marked instanton-size scale $<\rho> \approx
+0.5$ fm being reflected in the conspicuous ``geometrization'' of soft QCD. As
+an explicit illustration, the known instanton contribution to DIS is
+transformed into the intuitive colour dipole picture. With the help of lattice
+results, the $q \bar{q}$-dipole size r is carefully increased towards hadronic
+dimensions. Unlike pQCD, one now observes a competition between two crucial
+length scales: the dipole size r and the size $\rho$ of the background
+instanton that is sharply localized around $<\rho> \approx 0.5$ fm. For r
+exceeding $<\rho>$, the dipole cross section indeed saturates towards a
+geometrical limit, proportional to the area $\pi <\rho>^2$, subtended by the
+instanton.",0207052v2
+2002-07-03,Saturation and Wilson Line Distributions,"We introduce a Wilson line distribution function bar{W}_tau(v) to study gluon
+saturation at small Feynman x_F, or large tau=ln(1/x_F). This new distribution
+can be obtained from the distribution W_tau(alpha) of the Color Glass
+Condensate model and the JIMWLK renormalization group equation. bar{W}_tau(v)
+is physically more relevant, and mathematically simpler to deal with because of
+unitarity of the Wilson line v. A JIMWLK equation is derived for bar{W}_tau(v);
+its properties are studied. These properties are used to complete Mueller's
+derivation of the JIMWLK equation, though for bar{W}_tau(v) and not
+W_tau(alpha). They are used to derive a generalized Balitsky-Kovchegov equation
+for higher multipole amplitudes. They are also used to compute the unintegrated
+gluon distribution at x_F=0, yielding a completely flat spectrum in transverse
+momentum squared k^2, with a known height. This is similar but not identical to
+the mean field result at small k^2.",0207058v2
+2002-07-31,Diffractive dissociation from non-linear evolution in DIS on nuclei,"The process of single diffractive dissociation off nuclei is considered on a
+basis of solutions to the nonlinear evolution equation. The relevant saturation
+scales $Q_{s A}^D(x,x_0)$ are determined and their dependences on Bjorken $x$,
+atomic number $A$, and minimal rapidity gap $Y_0\equiv \ln 1/x_0$ are
+investigated. The solutions are shown to posses the geometrical scaling in a
+broad kinematic region for $x$ well below $x_0$. A detailed theoretical
+discussion of saturation scale and scaling is presented.
+  The ratio $\sigma^{diff}/\sigma^{tot}$ is computed for several nuclei. We
+predict that at $x\simeq 10^{-4}$ this ratio is of the order 25% which is much
+larger to the one of proton. This result indicates a possibility to observe a
+very strong nuclear shadowing.",0207374v2
+2003-03-12,Investigating the Drell-Yan transverse momentum distribution in the color dipole approach,"We study the influence of unitarity corrections on the Drell-Yan transverse
+momentum distribution within the color dipole approach. These unitarity
+corrections are implemented through the multiple scattering Glauber-Mueller
+approach, which is contrasted with a phenomenological saturation model. The
+process is analyzed for the center of mass energies of the Relativistic Heavy
+Ion Collider (RHIC, $\sqrt{s}=500$ GeV) and of the Large Hadron Collider (LHC,
+$\sqrt{s}=14$ TeV). In addition, the results are extrapolated down to current
+energies of proton-proton collisions, where non-asymptotic corrections to the
+dipole approach are needed. It is also shown that in the absence of saturation,
+the dipole approach can be related to the QCD Compton process.",0303100v2
+2003-03-25,Screening effects in the ultrahigh energy neutrino interactions,"We study possible saturation effects in the total cross-section describing
+interaction of ultrahigh energy neutrinos with nucleons. This analysis is
+performed within the two approaches, i.e. within the Golec-Biernat W\""usthoff
+saturation model and within the scheme unifying the DGLAP and BFKL dynamics
+incorporating non-linear screening effects which follow from the
+Balitzki-Kovchegov equation. The structure functions in both approaches are
+constrained by HERA data. It is found that screening effects affect
+extrapolation of the neutrino-nucleon total cross-sections to ultrahigh
+neutrino energies $E_{\nu}$ and reduce their magnitude by a factor equal to
+about 2 at $E_{\nu} \sim 10^{12}GeV$. This reduction becomes amplified by
+nuclear shadowing in the case of the neutrino-nucleus cross-sections and
+approximate estimate of this effect is performed.",0303209v4
+2003-05-14,QCD Saturation in the Semi-classical Approach,"In this paper the semi-classical approach to the solution of non-linear
+evolution equation is developed. We found the solution in the entire kinematic
+region to the non-linear evolution equation that governs the dynamics in the
+high parton density QCD. The large impact parameter ($b_t$) behavior of the
+solution is discussed as well as the way how to include the non-perturbative
+QCD corrections in this region of $b_t$. The geometrical scaling behavior and
+other properties of the solution in the saturation (Color Glass Condensate)
+kinematic domain are analyzed. We obtain the asymptotic behavior for the
+physical observables and found the unitarity bounds for them.",0305150v2
+2003-06-13,Additional $J/Ψ$ Suppression from High Density Effects,"At high energies the saturation effects associated to the high parton density
+should modify the behavior of the observables in proton-nucleus and
+nucleus-nucleus scattering. In this paper we investigate the saturation effects
+in the nuclear $J/\Psi$ production and estimate the modifications in the energy
+dependence of the cross section as well as in the length of the nuclear medium.
+In particular, we calculate the ratio of $J/\Psi$ to Drell-Yan cross sections
+and show that it is strongly modified if the high density effects are included.
+Moreover, our results are compared with the data from the NA50 Collaboration
+and predictions for the RHIC and LHC kinematic regions are presented. We
+predict an additional $J/\Psi$ suppression associated to the high density
+effects.",0306129v2
+2003-09-25,Perturbative Odderon in the Dipole Model,"We show that, in the framework of Mueller's dipole model, the perturbative
+QCD odderon is described by the dipole model equivalent of the BFKL equation
+with a $C$-odd initial condition. The eigenfunctions and eigenvalues of the
+odderon solution are the same as for the dipole BFKL equation and are given by
+the functions $E^{n,\nu}$ and $\chi (n,\nu)$ correspondingly, where the $C$-odd
+initial condition allows only for odd values of $n$. The leading high-energy
+odderon intercept is given by $\alpha_{odd} - 1 = \frac{2 \as N_c}{\pi} \chi
+(n=1 ,\nu=0) = 0$ in agreement with the solution found by Bartels, Lipatov and
+Vacca. We proceed by writing down an evolution equation for the odderon
+including the effects of parton saturation. We argue that saturation makes the
+odderon solution a decreasing function of energy.",0309281v2
+2003-09-25,Finite energy chiral sum rules in QCD,"The saturation of QCD chiral sum rules of the Weinberg-type is analyzed using
+ALEPH and OPAL experimental data on the difference between vector and
+axial-vector correlators (V-A). The sum rules exhibit poor saturation up to
+current energies below the tau-lepton mass. A remarkable improvement is
+achieved by introducing integral kernels that vanish at the upper limit of
+integration. The method is used to determine the value of the finite remainder
+of the (V-A) correlator, and its first derivative, at zero momentum:
+$\bar{\Pi}(0) = - 4 \bar{L}_{10} = 0.0257 \pm 0.0003 ,$ and
+$\bar{\Pi}^{\prime}(0) = 0.065 \pm 0.007 {GeV}^{-2}$. The dimension $d=6$ and
+$d=8$ vacuum condensates in the Operator Product Expansion are also determined:
+  $<{\cal {O}}_{6}> = -(0.004 \pm 0.001) {GeV}^6,$ and $<{\cal {O}}_{8}> =
+-(0.001 \pm 0.006) {GeV}^8.$",0309285v2
+2003-10-31,Open charm production in heavy ion collisions and the Color Glass Condensate,"We consider the production of open charm in heavy ion collisions in the
+framework of the Color Glass Condensate. In the central rapidity region at
+RHIC, for the charm quark yield we expect N(coll) (number of collisions)
+scaling in the absence of final-state effects. At higher energies, or forward
+rapidities at RHIC, the saturation scale exceeds the charm quark mass; we find
+that this results in the approximate N(part) (number of participants) scaling
+of charm production in AA collisions and N(part)^A scaling in p(d)A collisions,
+similarly to the production of high pT gluons discussed earlier. We also show
+that the saturation phenomenon makes spectra harder as compared to the naive
+parton model approach. We then discuss the energy loss of charm quarks in hot
+and cold media and argue that the hardness of the spectrum implies very slow
+dependence of the quenching factor on pT.",0310358v1
+2003-12-26,"Elliptic flow orientation, saturation and low $p_t$ behavior","We consider general model with factorization between macroscopic flow and
+matter decay distribution. We show universality of $p_t^2$ behavior of elliptic
+flow at small $p_t$ for identified final particles in the symmetric nucleus
+collision. At high $p_t$ we compare non-relativistic and relativistic models
+for boosted decay distribution. In the relativistic models with distribution
+having power-like tail we show existence of elliptic flow saturation. This
+means that the elliptic flow value $v_2$ tend to constant at high $p_t$. We
+discuss the importance of determination of elliptic flow orientation which can
+help us to compare different models. For example, we introduce potential
+expansion model which can reproduce azimuthal asymmetry but based on the
+assumption that there are only cold strong forces and no thermalization. This
+model show opposite sign of elliptic flow orientation in comparison with
+thermal model. We also show that at small $p_t$ sign of elliptic flow can
+change due to sign of second derivative of decay distribution. This fact tell
+us that we must more carefully link elliptic flow sign and properties of the
+model.",0312352v1
+2004-01-06,Towards a New Global QCD Analysis: Solution to the Non-Linear Equation at Arbitrary Impact Parameter,"A numerical solution is presented for the non-linear evolution equation that
+governs the dynamics of high parton density QCD. It is shown that thesolution
+falls off as $e^{-b/R}$ at large values of the impact parameter $b$. The
+power-like tail of the amplitude appears in impact parameter distributions only
+after the inclusion of dipoles of size larger than the target, a configuration
+for which the non-linear equation is not valid. The value, energy and impact
+parameterof the saturation scale $Q_s(y=\ln(1/x),b)$) are calculated both for
+fixed and running QCD coupling cases. It is shown that the solution exhibits
+geometrical scaling behaviour. The radius of interaction increases as the
+rapidity in accordance with the Froissart theorem. The solution we obtain
+differs from previous attempts, where an anzatz for $b$ behaviour was made. The
+solutions for running and fixed $\as$ differ. For running $\as$ we obtain a
+larger radius of interaction (approximately twice as large), a steeper rapidity
+dependence, and a larger value of the saturation scale.",0401021v2
+2004-05-13,Density saturation and the decrease of the normalised width of the multiplicity distribution in high energy pp collisions,"It is experimentally observed that the width of the KNO multiplicity
+distribution --or the negative binomial parameter 1/k-- for pp collisions, in
+the energy region 10 to 1800 GeV, is an increasing function of the energy. We
+argue that in models with parton or string saturation such trend will necessary
+change: at some energy the distribution will start to become narrower. In the
+framework of percolating strings, we have estimated the change to occur at an
+energy of the order of 5--10 TeV.",0405116v2
+2004-05-18,Evidence for the saturation of the Froissart bound,"It is well known that fits to high energy data cannot discriminate between
+asymptotic ln(s) and ln^2(s) behavior of total cross section. We show that this
+is no longer the case when we impose the condition that the amplitudes also
+describe, on average, low energy data dominated by resonances. We demonstrate
+this by fitting real analytic amplitudes to high energy measurements of the
+gamma p total cross section, for sqrt(s) > 4 GeV. We subsequently require that
+the asymptotic fit smoothly join the sqrt(s) = 2.01 GeV cross section described
+by Dameshek and Gilman as a sum of Breit-Wigner resonances. The results
+strongly favor the high energy ln^2(s) fit of the form sigma_{gamma p} = c_0 +
+c_1 ln(nu/m) + c_2 ln^2(nu/m) + beta_{P'}/sqrt(nu/m), basically excluding a
+ln(s) fit of the form sigma_{\gamma p} = c_0 + c_1 ln(nu/m) +
+beta_P'/sqrt(\nu/m), where nu is the laboratory photon energy. This evidence
+for saturation of the Froissart bound for gamma p interactions is confirmed by
+applying the same analysis to pi p data using vector meson dominance.",0405174v1
+2004-06-11,The spread of the gluon k_t-distribution and the determination of the saturation scale at hadron colliders in resummed NLL BFKL,"The transverse momentum distribution of soft hadrons and jets that accompany
+central hard-scattering production at hadron colliders is of great importance,
+since it has a direct bearing on the ability to separate new physics signals
+from Standard Model backgrounds. We compare the predictions for the gluonic
+k_t-distribution using two different approaches: resummed NLL BFKL and DGLAP
+evolution. We find that as long as the initial and final virtualities (k_t)
+along the emission chain are not too close to each other, the NLL resummed BFKL
+results do not differ significantly from those obtained using standard DGLAP
+evolution. The saturation momentum Q_s(x), calculated within the resummed BFKL
+approach, grows with 1/x even slower than in the leading-order DGLAP case.",0406135v2
+2004-06-14,Saturation In Deep Inelastic Scattering,"The solution to the BFKL equation grows like a power of center of mass
+energy, s, violating unitarity conditions at high energies. The growth of the
+cross section can be tamed by taking into account multiple pomeron exchanges.
+This is known as saturation and it is expressed in the Balitsky-Kovchegov
+equation. Conservation of energy should also slow down the growth of the cross
+section, and our aim in this work is to study the effects of enforcing energy
+conservation in DIS-events. Using the dipole picture, onium-onium collisions
+can be viewed, in the large N_c and the leading logarithmic limits, as the
+scattering of a collection of color dipoles. We construct a Monte Carlo
+program, based on Mueller's model and using energy conservation, to study
+onium-onium and onium-nucleus collisions. Dipole fusion processes will be
+important at high gluon densities and should also slow down the growth of the
+cross section. We propose an expression for the fusion factor and use it in our
+Monte Carlo to study its effects.",0406150v1
+2004-08-09,Unintegrated gluon distribution from modified BK equation,"We investigate the recently proposed nonlinear equation for the unintegrated
+gluon distribution function which includes the subleading effects at small $x$.
+We obtained numerically the solution to this equation in $(x,k)$ space, and
+also the integrated gluon density. The subleading effects affect strongly the
+normalization and the $x$ and $k$ dependence of the gluon distribution. We show
+that the saturation scale $Q_s(x)$, which is obtained from this model, is
+consistent with the one used in the saturation model by Golec-Biernat and
+W\""usthoff. We also estimate the nonlinear effects by looking at the relative
+normalization of the solutions to the linear and nonlinear equations. It turns
+out that the differences are quite large even in the nominally dilute regime,
+that is when $Q^2 \gg Q_s^2$. Finally, we calculate the dipole-nucleon cross
+section.",0408117v3
+2004-08-20,Cronin effect and high-p_T suppression from the Color Glass Condensate,"I give a pedagogical survey of the nuclear collective effects associated with
+gluon saturation and their impact on particle production in high-energy proton
+(or deuteron)-nucleus collisions at RHIC. At central rapidity, the theory
+predicts a Cronin peak due to independent multiple scattering off the valence
+quarks in the nucleus. At forward rapidities, the peak flattens out and
+disappears very fast, because of the correlations induced through quantum
+evolution in the nuclear gluon distribution at small x. Also, the ratio R_{pA}
+between the particle yield in proton-nucleus and proton-proton collisions is
+rapidly suppressed when increasing the rapidity, because of saturation effects
+which slow down the evolution of the nucleus compared to that of the proton.
+This behaviour could be responsible for a similar trend observed in the
+deuteron-nucleus collisions at RHIC.",0408228v1
+2004-08-30,Higher Order Effects in Non Linear Evolution from a Veto in Rapidities,"Higher order corrections to the Balitsky-Kovchegov equation have been
+estimated by introducing a rapidity veto which forbids subsequent emissions to
+be very close in rapidity and is known to mimic higher order corrections to the
+linear BFKL equation. The rapidity veto constraint has been first introduced
+using analytical arguments obtaining a power growth with energy, Q_s (Y) ~
+exp(lambda Y), of the saturation scale of lambda ~ 0.45. Then a numerical
+analysis for the non-linear Balitsky-Kovchegov equation has been carried out
+for phenomenological rapidities: when a veto of about two units of rapidity is
+introduced for a fixed value of the coupling constant of alpha_s = 0.2 the
+saturation scale lambda decreases from ~ 0.6 to ~ 0.3, and when running
+coupling effects are taken into account it decreases from ~ 0.4 to ~ 0.3.",0408333v1
+2004-11-18,A modified Balitsky-Kovchegov equation,"We propose a modified version of the Balitsky-Kovchegov (B-K) evolution
+equation, which includes the main NLO corrections. We use the result that the
+main NLO corrections to the BFKL kernel are the LO DGLAP corrections.
+  We present a numerical solution of the modified nonlinear equation, and
+compare with the solution of the unmodified B-K equation. We show that the
+saturation momentum has a sharp increase in the LHC energy range. Our numerical
+solution indicates that the influence of the pre-asymptotic corrections,
+related to the full anomolous dimensions of the DGLAP equation, are rather
+large. These corrections moderate the energy behaviour of the amplitude, as
+well as the value of the saturation scale. All our calculations are made with a
+fixed value of $\alpha_{s}$.",0411242v2
+2004-11-30,A Langevin equation for high energy evolution with pomeron loops,"We show that the Balitsky-JIMWLK equations proposed to describe non-linear
+evolution in QCD at high energy fail to include the effects of fluctuations in
+the gluon number, and thus to correctly describe both the low density regime
+and the approach towards saturation. On the other hand, these fluctuations are
+correctly encoded (in the limit where the number of colors is large) in
+Mueller's color dipole picture, which however neglects saturation. By combining
+the dipole picture at low density with the JIMWLK evolution at high density, we
+construct a generalization of the Balitsky hierarchy which includes the
+particle number fluctuations, and thus the pomeron loops. After an additional
+coarse-graining in impact parameter space, this hierarchy is shown to reduce to
+a Langevin equation in the universality class of the stochastic
+Fisher-Kolmogorov-Petrovsky-Piscounov (sFKPP) equation. This equation implies
+that the non-linear effects in the evolution become important already in the
+high momentum regime where the average density is small, which signals the
+breakdown of the BFKL approximation.",0411405v1
+2004-12-22,Saturation effects in pp scattering in the impact-parameter representation,"The impact of unitarity is considered in different approaches to saturation
+in impact-parameter space. The energy and momentum-transfer dependence of the
+total and differential cross sections and of the ratio of the real to imaginary
+parts of the scattering amplitude are obtained in a model that includes soft
+and hard pomeron contributions, coupled to hadrons via the electromagnetic form
+factor. It is shown that the hard pomeron may significantly contribute to soft
+physics at the LHC. A similar conclusion can also be reached in the framework
+of non-linear approaches to unitarisation of the BFKL pomeron.",0412338v1
+2005-02-18,Nuclear size and rapidity dependence of the saturation scale from QCD evolution and experimental data,"The solutions of the Balitsky-Kovchegov evolution equations are studied
+numerically and compared with known analytical estimations. The rapidity and
+nuclear size dependences of the saturation scale are obtained for the cases of
+fixed and running coupling constant. These same dependences are studied in
+experimental data, on lepton-nucleus, deuteron-nucleus and nucleus-nucleus
+collisions, through geometric scaling and compared with the theoretical
+calculations.",0502167v1
+2005-03-07,Fluctuating pulled fronts & Pomerons,"I give a physical discussion of the influence of particle number fluctuations
+on the high energy evolution in QCD. I emphasize the event-by-event description
+and the correspondence with the problem of `fluctuating pulled fronts' in
+statistical physics. I show that the correlations generated by fluctuations
+reduce the phase-space for BFKL evolution up to saturation. Because of that,
+the evolution `slows down', and the rate for the energy increase of the
+saturation momentum is considerably decreased. Also, the stochastic aspects
+inherent in fluctuations lead to the breakdown of geometric scaling and of the
+BFKL approximation. Finally, I explain the diagrammatic interpretation of the
+particle number fluctuations as initiators of the Pomeron loops.",0503062v1
+2005-03-29,Investigating the role of average color dipole size in BFKL Pomeron phenomenology,"Based on the QCD dipole picture of the BFKL Pomeron, we investigate the role
+played by the saturation scale, Q_{sat}, in obtaining physical values for the
+affective strong coupling in phenomenological fits to small-x HERA data. The
+dependence on this scale appears since the collection of color dipoles
+characterizing the proton target have average size 1/Q_{sat}, which is energy
+dependent. Physically, this means most of the color dipoles are above but
+sufficiently close to the border between a saturated and the dilute system. The
+analysis is first performed in the leading-logs BFKL approach in the
+saddle-point approximation and it could shed light in further investigations
+using resummed NLO BFKL kernels",0503282v2
+2005-07-13,Instanton-Induced Processes - An Overview,"A first part of this review is devoted to a summary of our extensive studies
+of the discovery potential for instanton(I)-induced, deep-inelastic processes
+at HERA. Included are some key issues about I-perturbation theory, an
+exploitation of crucial lattice constraints and a status report about the
+recent I-search results by the HERA collaborations H1 and ZEUS in relation to
+our predictions. Next follows a brief outline of an ongoing project concerning
+a broad exploration of the discovery potential for hard instanton processes at
+the LHC. I then turn to an overview of our work on high-energy processes,
+involving larger-sized instantons. I shall mainly focus on the phenomenon of
+saturation at small Bjorken-x from an instanton perspective. In such a
+framework, the saturation scale is associated with the conspicuous average
+instanton size (~0.5 fm), as known from lattice simulations. Another central
+and intriguing result is the identification of the ""Colour Glass Condensate""
+with the QCD sphaleron state.",0507160v1
+2005-09-23,Nonlinear evolution of pomeron and odderon in momentum space,"The small x evolution of the QCD pomeron and the QCD odderon is investigated
+in the mean field limit of the Color Glass Condensate. The resulting system of
+coupled nonlinear evolution equations is transformed to the momentum space and
+analyzed at a very small momentum transfer. The main properties of the C-even
+and C-odd dipole densities in momentum space are obtained analytically. The
+critical scaling dimension is found for the odderon and the universal
+asymptotic behavior of the solutions is determined for small and large gluon
+momenta. We find that the same saturation scale characterizes both the pomeron
+and the odderon and both densities depend on the momentum only through the
+geometric scaling variable. The absorptive effects are found to cause a strong
+suppression of the odderon exchange amplitude for momenta below saturation
+scale and only a moderate suppression for larger momenta.",0509270v1
+2005-11-08,The Energy Dependence of the Saturation Scale,"At low $x \cong Q^2/W^2 << 1$, in deep inelastic scattering, the photon
+fluctuates into a $q \bar q$ vector state that interacts via two gluons with
+the proton. The energy dependence is determined by the saturation scale, in our
+approach given by $\Lambda^2_{sat} (W^2) \sim (W^2)^{C_2}$. Imposing DGLAP
+evolution, we find $C_2^{theory} = 0.27$ in agreement with the
+model-independent analysis of the HERA data. Different values of the exponent
+$C_2$ are correlated with different ratios of the longitudinal to transverse
+structure function. This stresses the need for experiments to separate
+longitudinal and transverse contributions in deep inelastic scattering.",0511091v2
+2005-12-08,The Decoherence Time in High Energy Heavy Ion Collisions,"We calculate the decoherence time of the ground state wave function of a
+nucleus in a high energy heavy ion collision. We define this time as the decay
+time of the ratio Tr D^2 / (Tr D)^2 of traces of the density matrix D. We find
+that this time is smaller or equal to 1/Q_s, where the saturation scale Q_s is
+defined within the color glass condensate model of parton saturation. Our
+result supports the notion that the extremely rapid entropy production deduced
+for the early stage of heavy ion collisions at collider energies is to a large
+extent caused by the decoherence of the initial-state wave functions.",0512100v2
+2006-02-10,Spin-glass model of QCD near saturation,"We establish a connection between the cascading of gluon momenta modeled with
+the diffusive approximation of the Balitsky-Fadin-Kuraev-Lipatov kernel and the
+thermodynamics of directed polymers on a tree with disorder. Using known
+results on the low-temperature spin-glass phase of this statistical-mechanic
+problem we describe the dynamical phase space of gluon transverse momenta near
+saturation including its fluctuation pattern. It exhibits a nontrivial
+clustering structure, analoguous to ``hot spots'', whose distributions are
+derived and possess universal features in common with other spin-glass systems.",0602095v3
+2006-04-26,Color Glass Condensates in dense quark matter and quantum Hall states of gluons,"We apply the effective theory of color glass condensate to the analysis of
+gluon states in dense quark matter, in which the saturation region of gluons is
+also present. We find that in the region two point function of gluons shows
+algebraic long range order. The order is completely the same as the one gluons
+show in the dense quark matter, which form quantum Hall states. The order leads
+to the vanishing of massless gluon pole. We also find that the saturation
+region of gluons extends from small $x$ to even large $x\lesssim 1$ in much
+dense quark matter. We point out a universality that the color glass condensate
+is a property of hadrons at high energy and of quark matter at high baryon
+density.",0604222v1
+2006-05-15,Forward gluon production in hadron-hadron scattering with Pomeron loops,"We discuss new physical phenomena expected in particle production in
+hadron-hadron collisions at high energy, as a consequence of Pomeron loop
+effects in the evolution equations for the Color Glass Condensate. We focus on
+gluon production in asymmetric, `dilute-dense', collisions : a dilute
+projectile scatters off a dense hadronic target, whose gluon distribution is
+highly evolved. This situation is representative for particle production in
+proton-proton collisions at forward rapidities (say, at LHC) and admits a
+dipole factorization similar to that of deep inelastic scattering (DIS). We
+show that at sufficiently large forward rapidities, where the Pomeron loop
+effects become important in the evolution of the target wavefunction, gluon
+production is dominated by `black spots' (saturated gluon configurations) up to
+very large values of the transverse momentum, well above the average saturation
+momentum in the target. In this regime, the produced gluon spectrum exhibits
+diffusive scaling, so like DIS at sufficiently high energy.",0605174v1
+2006-06-20,Hadronic forward scattering: Predictions for the Large Hadron Collider and cosmic rays,"The status of hadron-hadron interactions is reviewed, with emphasis on the
+forward and near-forward scattering regions. From analyticity, Finite Energy
+Sum Rules are introduced from which new analyticity constraints are derived
+that exploit the many very accurate low energy experimental cross sections,
+i.e., they constrain the values of the asymptotic cross sections and their
+derivatives at low energies just above the resonance regions, allowing us new
+insights into duality. A new robust fitting technique is introduced in order to
+`clean up' large data samples that are contaminated by outliers. Using our
+analyticity constraints, new methods of fitting high energy hadronic data are
+introduced which result in much more precise estimates of the fit parameters,
+allowing accurate extrapolations to much higher energies. It's shown that the
+$\gamma p$, $\pi^\pm p$ and nucleon-nucleon cross sections {\em all} go
+asymptotically as $\ln^2s$, saturating the Froissart bound, while conclusively
+ruling out $\ln s$ and $s^{\alpha}$ ($\alpha\sim 0.08$) behavior. Implications
+of this saturation for predictions of $\sigma_{pp}$ and $\rho_{pp}$ at the LHC
+and for cosmic rays p-air cross sections are given.",0606215v2
+2006-06-27,Exclusive diffractive processes at HERA within the dipole picture,"We present a simultaneous analysis, within an impact parameter dependent
+saturated dipole model, of exclusive diffractive vector meson (J/psi, phi and
+rho) production, deeply virtual Compton scattering and the total gamma* p cross
+section data measured at HERA. Various cross sections measured as a function of
+the kinematic variables Q^2, W and t are well described, with little
+sensitivity to the details of the vector meson wave functions. We determine the
+properties of the gluon density in the proton in both longitudinal and
+transverse dimensions, including the impact parameter dependent saturation
+scale. The overall success of the description indicates universality of the
+emerging gluon distribution and proton shape.",0606272v2
+2006-11-08,One-dimensional model for QCD at high energy,"We propose a stochastic particle model in (1+1)-dimensions, with one
+dimension corresponding to rapidity and the other one to the transverse size of
+a dipole in QCD, which mimics high-energy evolution and scattering in QCD in
+the presence of both saturation and particle-number fluctuations, and hence of
+Pomeron loops. The model evolves via non-linear particle splitting, with a
+non-local splitting rate which is constrained by boost-invariance and multiple
+scattering. The splitting rate saturates at high density, so like the gluon
+emission rate in the JIMWLK evolution. In the mean field approximation obtained
+by ignoring fluctuations, the model exhibits the hallmarks of the BK equation,
+namely a BFKL-like evolution at low density, the formation of a traveling wave,
+and geometric scaling. In the full evolution including fluctuations, the
+geometric scaling is washed out at high energy and replaced by diffusive
+scaling. It is likely that the model belongs to the universality class of the
+reaction-diffusion process. The analysis of the model sheds new light on the
+Pomeron loops equations in QCD and their possible improvements.",0611105v1
+1993-12-14,Instantons in Schwinger Model,"The known calculations of the fermion condensate $<\bar{\psi}\psi>$ and the
+correlator $<\bar{\psi}\psi(x) ~\bar{\psi}\psi(0)>$ have been interpreted in
+terms of {\em localized} instanton solutions minimizing the {\em effective}
+action. Their size is of order of massive photon Compton wavelength $\mu^{-1}$.
+At high temperature, these instantons become quasistatic and present the
+2-dimensional analog of the `walls' found recently in 4-dimensional gauge
+theories. In spite of the static nature of these solutions, they should not be
+interpreted as `thermal solitons' living in Minkowski space: the mass of these
+would-be solitons does not display itself in the physical correlators. At small
+but nonzero fermion mass, the high-T partition function of $QED_2$ is saturated
+by the rarefied gas of instantons and antiinstantons with density $\propto
+m~\exp\{-S^{inst.}\}~=~m~\exp\{-\pi T/\mu\}$ to be confronted with the dense
+strongly correlated instanton-antiinstanton liquid saturating the partition
+function at $T=0$.",9312110v1
+1995-09-20,Rotating Black Holes which Saturate a Bogomol'nyi Bound,"We construct and study the electrically charged, rotating black hole solution
+in heterotic string theory compactified on a $(10-D)$ dimensional torus. This
+black hole is characterized by its mass, angular momentum, and a $(36-2D)$
+dimensional electric charge vector. One of the novel features of this solution
+is that for $D >5$, its extremal limit saturates the Bogomol'nyi bound. This is
+in contrast with the $D=4$ case where the rotating black hole solution develops
+a naked singularity before the Bogomol'nyi bound is reached. The extremal black
+holes can be superposed, and by taking a periodic array in $D>5$, one obtains
+effectively four dimensional solutions without naked singularities.",9509108v1
+1995-12-28,T-Duality of p-Branes,"We investigate possible existence of duality symmetries which exchange the
+Kaluza-Klein modes with the wrapping modes of a BPS saturated $p$-brane on a
+torus. Assuming the validity of the conjectured $U$-duality symmetries of type
+II and heterotic string theories and $M$-theory, we show that for a BPS
+saturated $p$-brane there is an SL(2,Z) symmetry that mixes the Kaluza-Klein
+modes on a $(p+1)$ dimensional torus $T^{(p+1)}$ with the wrapping modes of the
+$p$-brane on $T^{(p+1)}$. The field that transforms as a modular parameter
+under this SL(2,Z) transformation has as its real part the component of the
+$(p+1)$-form gauge field on $T^{(p+1)}$, and as its imaginary part the volume
+of $T^{(p+1)}$, measured in the metric that couples naturally to the $p$-brane.",9512203v2
+1996-05-08,Near-BPS-Saturated Rotating Electrically Charged Black Holes as String States,"We construct generating solutions for general D-dimensional ($4 \le D \le 9$)
+rotating, electrically charged, black holes in the effective action of
+toroidally compactified heterotic (or Type IIA) string. The generating solution
+is parameterized by the ADM mass, two electric charges and $[{D-1}\over 2]$
+angular momenta (as well as the asymptotic values of one toroidal modulus and
+the dilaton field). For $D \ge 6$, those are generating solutions for {\it
+general} black holes in toroidally compactified heterotic (or type IIA) string.
+Since in the BPS-limit (extreme limit) these solutions have singular horizons
+or naked singularities, we address the near extreme solutions with all the
+angular momenta small enough. In this limit, the thermodynamic entropy can be
+cast in a suggestive form, which has a qualitative interpretation as
+microscopic entropy of (near)-BPS-saturated charged string states of toroidally
+compactified heterotic string, whose target-space angular momenta are
+identified as $[{{D-1}\over 2}]$ U(1) left-moving world-sheet currents.",9605051v1
+1997-10-15,Domain Walls Zoo in Supersymmetric QCD,"Solving numerically the equations of motion for the effective lagrangian
+describing supersymmetric QCD with the SU(2) gauge group, we find a menagerie
+of complex domain wall solutions connecting different chirally asymmetric
+vacua. Some of these solutions are BPS saturated walls; they exist when the
+mass of the matter fields does not exceed some critical value m < m* <
+4.67059... There are also sphaleron branches (saddle points of the ebergy
+functional). In the range m* < m < m** \approx 4.83, one of these branches
+becomes a local minimum (which is not a BPS saturated one). At m > m*, the
+complex walls disappear altogether and only the walls connecting a chirally
+asymmetric vacuum with the chirally symmetric one survive.",9710123v1
+1997-11-11,BPS-spectra in four dimensions from M-theory,"I review my work together with Piljin Yi on the spectrum of BPS-saturated
+states in N = 2 supersymmetric Yang-Mills theories. In an M-theory description,
+such states are realized as certain two-brane configurations. We first show how
+the central charge of the N = 2 algebra arises from the two-form central charge
+of the eleven-dimensional supersymmetry algebra, and derive the condition for a
+two-brane configuration to be BPS-saturated. We then discuss how the topology
+of the two-brane determines the type of BPS-multiplet. Finally, we discuss the
+phenomenon of marginal stability and show how it is related to the mutual
+non-locality of states.",9711076v1
+1998-04-25,Multi-Pronged Strings and BPS Saturated Solutions in SU(N) Supersymmetric Yang-Mills Theory,"Extending our previous work on SU(3), we construct spherically symmetric BPS
+saturated regular configurations of N=4 SU(N) supersymmetric Yang-Mills theory
+preserving 1/4 supersymmetry, and investigate their features. We also give
+exact solutions in the case some of the free parameters of the general
+solutions take certain values. These field theory BPS states correspond to the
+string theory BPS states of multi-pronged strings connecting N different
+D3-branes by regarding the N=4 supersymmetric Yang-Mills theory as an effective
+field theory on parallel D3-branes. We compare our solutions with multi-pronged
+strings in string picture.",9804164v2
+1999-01-12,Classical Corrections in String Cosmology,"An important element in a model of non-singular string cosmology is a phase
+in which classical corrections saturate the growth of curvature in a
+deSitter-like phase with a linearly growing dilaton (an `algebraic fixed
+point'). As the form of the classical corrections is not well known, here we
+look for evidence, based on a suggested symmetry of the action, scale factor
+duality and on conformal field theory considerations, that they can produce
+this saturation. It has previously been observed that imposing scale factor
+duality on the $O(\alpha')$ corrections is not compatible with fixed point
+behavior. Here we present arguments that these problems persist to all orders
+in $\alpha'$. We also present evidence for the form of a solution to the
+equations of motion using conformal perturbation theory, examine its
+implications for the form of the effective action and find novel fixed point
+structure.",9901044v1
+1999-07-05,Supersymmetric Baryonic Branes,"We derive an energy bound for a `baryonic' D5-brane probe in the $adS_5\times
+S^5$ background near the horizon of $N$ D3-branes. Configurations saturating
+the bound are shown to be 1/4 supersymmetric $S^5$-wrapped D5-branes, with a
+total Born-Infeld charge $N$. Previous results are recovered as a special case.
+We derive a similar energy bound for a `baryonic' M5-brane probe in the
+background of $N$ M5-branes. Configurations saturating the bound are again 1/4
+supersymmetric and, in the $adS_7\times S^4$ near-horizon limit, provide a
+worldvolume realization of the `baryon string' vertex of the
+(2,0)-supersymmetric six-dimensional conformal field theory on coincident
+M5-branes. For the full M5-background we find a worldvolume realization of the
+Hanany-Witten effect in M-theory.",9907022v3
+1999-12-17,Calculating the tension of domain wall junctions and vortices in generalized Wess-Zumino models,"We study BPS saturated objects with axial geometry (wall junctions, vortices)
+in generalized Wess-Zumino models. It is observed that the tension of such
+objects is negative in general (although ``exceptional'' models are possible).
+We show how an ambiguity in the definition of central charges does not affect
+physical quantities, and we comment on the stability of the junctions and
+vortices. We illustrate these issues in two classes of models with Z_N
+symmetry. On the basis of analytical large N calculations and numerical
+calculations at finite N, we argue that the domain wall junctions in these
+models are indeed BPS saturated, and we calculate the junction tensions
+explicitly.",9912162v1
+2002-07-08,The anomaly in the central charge of the supersymmetric kink from dimensional regularization and reduction,"We show that the anomalous contribution to the central charge of the
+1+1-dimensional N=1 supersymmetric kink that is required for BPS saturation at
+the quantum level can be linked to an analogous term in the extra momentum
+operator of a 2+1-dimensional kink domain wall with spontaneous parity
+violation and chiral domain wall fermions. In the quantization of the domain
+wall, BPS saturation is preserved by nonvanishing quantum corrections to the
+momentum density in the extra space dimension. Dimensional reduction from 2+1
+to 1+1 dimensions preserves the unbroken N=1/2 supersymmetry and turns these
+parity-violating contributions into the anomaly of the central charge of the
+supersymmetric kink. On the other hand, standard dimensional regularization by
+dimensional reduction from 1 to (1-epsilon) spatial dimensions, which also
+preserves supersymmetry, obtains the anomaly from an evanescent counterterm.",0207051v2
+2002-10-29,Holography in a Radiation-dominated Universe with a Positive Cosmological Constant,"We discuss the holographic principle in a radiation-dominated, closed
+Friedmann-Robertson-Walker (FRW) universe with a positive cosmological
+constant. By introducing a cosmological D-bound on the entropy of matter in the
+universe, we can write the Friedmann equation governing the evolution of the
+universe in the form of the Cardy formula. When the cosmological D-bound is
+saturated, the Friedmann equation coincides with the Cardy-Verlinde formula
+describing the entropy of radiation in the universe. As a concrete model, we
+consider a brane universe in the background of Schwarzschild-de Sitter black
+holes. It is found that the cosmological D-bound is saturated when the brane
+crosses the black hole horizon of the background. At that moment, the Friedmann
+equation coincides with the Cardy-Verlinde formula describing the entropy of
+radiation matter on the brane.",0210272v3
+2004-03-13,A Note on Curvature Fluctuation of Noncommutative Inflation,"An elegant approach, which incorporates the effect of the stringy spacetime
+uncertainty relation, to calculate power spectra of fluctuations during
+inflation has been suggested by Brandenberger and Ho. In this approach, one of
+important features is the appearance of an upper bound on the comoving momentum
+$k$, at which the stringy spacetime uncertainty relation is saturated. As a
+result, the time-dependent upper bound leads us to choose naturally a set of
+initial vacua for each mode, in which the stringy uncertainty relation is
+saturated. In this note, with that set of vacua we calculate power spectrum of
+curvature fluctuation for a power law inflation, up to the leading order of a
+parameter describing the spacetime noncommutativity. It turns out that this
+choice of initial vacuum has a significant effect on the power spectrum of
+fluctuations.",0403134v2
+2004-04-28,"New developments in the quantization of supersymmetric solitons (kinks, vortices and monopoles)","We discuss the one-loop quantum corrections to the mass M and central charge
+Z of supersymmetric solitons: the kink, the vortex and the monopole. Contrary
+to previous expectations and published results, in each of these cases there
+are nonvanishing quantum corrections to the mass. For the N=1 kink and the N=2
+monopole a new anomaly in Z rescues BPS saturation (M=Z); for the N=2 vortex,
+BPS saturation is rescued for two reasons: (i) the quantum fluctuations of the
+Higgs field acquire a nontrivial phase due to the winding of the classical
+solution, and (ii) a fermionic zero mode used in the literature is shown not to
+be normalizable.",0404223v1
+1998-07-28,The honeycomb model of GL(n) tensor products I: proof of the saturation conjecture,"We introduce the honeycomb model of BZ polytopes, which calculate
+Littlewood-Richardson coefficients, the tensor product rule for GL(n). Our main
+result is the existence of a particularly well-behaved honeycomb with given
+boundary conditions (choice of triple of representations to be tensored
+together). This honeycomb is necessarily integral, which proves the ""saturation
+conjecture"", extending results of Klyachko to give a complete answer to which
+L-R coefficients are positive. This in turn has as a consequence Horn's
+conjecture from 1962 characterizing the spectrum of the sum of two Hermitian
+matrices.",9807160v4
+2000-10-01,Bass Numbers of Semigroup-Graded Local Cohomology,"Given a module M over a ring R which has a grading by a semigroup Q, we
+present a spectral sequence that computes the local cohomology of M at any
+Q-graded ideal I in terms of Ext modules. This method is used to obtain
+finiteness results for the local cohomology of graded modules over semigroup
+rings; in particular we prove that for a semigroup Q whose saturation is
+simplicial, the Bass numbers of such local cohomology modules are finite.
+Conversely, if the saturation of Q is not simplicial, one can find a graded
+ideal I and a graded R-module M whose local cohomology at I in some degree has
+an infinite-dimensional socle. We introduce and exploit the combinatorially
+defined essential set of a semigroup.",0010003v2
+2002-10-17,The generalized triangle inequalities in symmetric spaces and buildings with applications to algebra,"In this paper we apply our results on the geometry of polygons in Cartan
+subspaces, symmetric spaces and buildings to four problems in algebraic group
+theory. Two of these problems are generalizations of the problems of finding
+the constraints on the eigenvalues (resp. singular values) of a sum (resp.
+product) when the eigenvalues (singular values) of each summand (factor) are
+fixed. The other two problems are related to the computation of the structure
+constants of the Hecke and representation rings associated with a split
+reductive algebraic group over Q and its complex Langlands' dual. We give a new
+proof of the ``Saturation Conjecture'' for GL(m) as a consequence of our
+solution of the corresponding ``saturation problem'' for the Hecke structure
+constants for all split reductive algebraic groups over Q.",0210256v5
+2005-01-19,Hyperbolicity of holomorphic foliations with parabolic leaves,"In this paper, we study a notion of hyperbolicity for hyperbolicity
+foliations with 1-dimensional parabolic leaves, namely the non-existence of
+holomorphic cylinders along the foliation - holomorphic maps from $\D^{n-1}
+\times \C$ to the manifold sending each $\{*\} \times \C$ to a leaf. We
+construct a tensor, that is a leaf-wise holomorphic section of a bundle above
+the foliated manifold, which vanishes on an open saturated set if and only if
+there exists such a cylinder through each point of this open set. Thanks to
+this study, we prove that open sets saturated by compact leaves are union of
+holomorphic cylinders along the foliation. We also give some more specific
+results and examples in the case of a compact manifold, and of foliations with
+one compact leaf or without any compact leaves.",0501292v1
+2005-01-28,Equidimensionality of convolution morphisms and applications to saturation problems,"We study the fibers of Mirkovic-Vilonen convolution morphisms. We prove their
+equidimensionality when all the coweights in question are minuscule, and some
+related statements. We give applications to saturation problems for structure
+constants of Hecke and representation rings. An erratum has been added to
+correct insufficiencies in the proofs of Lemma 9.4 and Corollary 9.5 as they
+appeared in the published version.",0501504v5
+2005-02-04,Classifying spectra of saturated fusion systems,"The assignment of classifying spectra to saturated fusion systems was
+suggested by Linckelmann and Webb and has been carried out by Broto, Levi and
+Oliver. A more rigid (but equivalent) construction of the classifying spectra
+is given in this paper. It is shown that the assignment is functorial for
+fusion-preserving homomorphisms in a way which extends the assignment of stable
+p-completed classifying spaces to finite groups, and admits a transfer theory
+analogous to that for finite groups. Furthermore the group of homotopy classes
+of maps between classifying spectra is described, and in particular it is shown
+that a fusion system can be reconstructed from its classifying spectrum
+regarded as an object under the stable classifying space of the underlying
+p-group.",0502092v5
+2005-05-12,Saturated chains in composition posets,"We study three different poset structures on the set of all compositions. In
+the first case, the covering relation consists of inserting a part of size one
+to the left or to the right, or increasing the size of some part by one. The
+resulting poset was studied by the author in ""A poset classifying
+non-commutative term orders"", and then in ""Standard paths in another
+composition poset"" where some results about generating functions for standard
+paths in this poset was established.
+  The latter article was inspired by the work of Bergeron, Bousquet-M{\'e}lou
+and Dulucq on ""Standard paths in the composition poset"", where they studied a
+poset where there are additional cover relations which allows the insertion of
+a part of size one anywhere in the composition. Finally, following a suggestion
+by Richard Stanley we study yet a third which is an extension of the previous
+two posets. This poset is related to quasi-symmetric functions.
+  For these posets, we study generating functions for saturated chains of fixed
+width k. We also construct ``labeled'' non-commutative generating functions and
+their associated languages.",0505262v2
+2006-02-21,An approach to non-standard analysis,"This note has two principal aims: to portray an essence of Non-Standard
+Analysis as a particular structure (which we call lim-rim), noting its
+interplay with the notion of ultrapower, and to present a construction of
+Non-Standard Analysis, viewed as a matter of mathematics, where the set *A of
+non-standard elements of a set A - ""the adjunction of all possible limits"" is a
+""good"" kind of lim-rim which plays a role analogous to the algebraic closure of
+a field - ""the adjunction of all roots of polynomials"". In the same spirit as
+with algebraic closures, one has uniqueness up to isomorphism, and also
+universality and homogeneity, provided one has enough Generalized Continuum
+Hypothesis. The cardinality of *A will be just something like 2^(2^|A|), and
+one has a high degree of saturation.",0602469v4
+2006-07-19,Saturation and Irredundancy for Spin(8),"We explicitly calculate the triangle inequalities for the group PSO(8).
+Therefore we explicitly solve the eigenvalues of sum problem for this group
+(equivalently describing the side-lengths of geodesic triangles in the
+corresponding symmetric space for the Weyl chamber-valued metric). We then
+apply some computer programs to verify two basic questions/conjectures. First,
+we verify that the above system of inequalities is irredundant. Then, we verify
+the ``saturation conjecture'' for the decomposition of tensor products of
+finite-dimensional irreducible representations of Spin(8). Namely, we show that
+for any triple of dominant weights a, b, c such that a+b+c is in the root
+lattice, and any positive integer N, the tensor product of the irreducible
+representations V(a) and V(b) contains V(c) if and only if the tensor product
+of V(Na) and V(Nb) contains V(Nc).",0607454v1
+2007-02-10,Dependent theories and the generic pair conjecture,"We try to understand complete types over a somewhat saturated model of a
+complete first order theory which is dependent (previously called NIP), by
+""decomposition theorems for such types"". Our thesis is that the picture of
+dependent theory is the combination of the one for stable theories and the one
+for the theory of dense linear order or trees (and first we should try to
+understand the quite saturated case). As a measure of our progress, we give
+several applications considering some test questions; in particular we try to
+prove the generic pair conjecture and do it for measurable cardinals.",0702292v6
+2007-03-21,A note on strong negative partition relations,"We analyze a natural function definable from a scale at a singular cardinal,
+and using this function we are able to obtain quite strong negative
+square-brackets partition relations at successors of singular cardinals. The
+proof of our main result makes use of club-guessing, and as a corollary we
+obtain a fairly easy proof of a difficult result of Shelah connecting weak
+saturation of a certain club-guessing ideal with strong failures of
+square-brackets partition relations. We then investigate the strength of weak
+saturation of such ideals and obtain some results on stationary reflection.",0703647v2
+2000-12-22,"Elimination of Chaos in Multimode, Intracavity-doubled Lasers in the Presence of Spatial Hole-burning","In this paper possibilities of a stabilization of large amplitude
+fluctuations in an intracavity-doubled solid-state laser are studied. The
+modification of the cross-saturation coefficient by the effect of spatial
+hole-burning is taken into account. The stabilization of the laser radiation by
+an increase of the number of modes, as proposed by James et al. (1990) and
+Magni et al. (1993), is analyzed. It is found that when the cross-saturation
+coefficient is modulated by the spatial hole-burning the stabilization is not
+always possible. We propose a new way of obtaining a stable steady-state
+configuration based on an increase of the strength of nonlinearity, which leads
+to a strong cancellation of modes, so that during the evolution all of the
+modes, but a single one, are canceled. Such a steady-state solution is found to
+be stable with respect to small perturbations.",0012051v1
+2001-03-13,One- and two-dimensional solitons in saturable media,"Very narrow spatial bright solitons in (1+1)D and (2+1)D versions of
+cubic-quintic and full saturable models are studied, starting from the full
+system of the Maxwell's equations, rather than from the paraxial (NLS)
+approximation. For the solitons with both TE and TM polarizations, it is shown
+that there always exists a finite minimum width, and they cease to exist at a
+critical value of the propagation constant, at which their width diverges. Full
+similarity of the results obtained for both nonlinearities suggests that the
+same general conclusions apply to narrow solitons in any non-Kerr model.",0103014v1
+2002-07-22,Frequency Dependence of Quantum Localization in a Periodically Driven System,"We study the quantum localization phenomena for a random matrix model
+belonging to the Gaussian orthogonal ensemble (GOE). An oscillating external
+field is applied on the system. After the transient time evolution, energy is
+saturated to various values depending on the frequencies. We investigate the
+frequency dependence of the saturated energy. This dependence cannot be
+explained by a naive picture of successive independent Landau-Zener transitions
+at avoided level crossing points. The effect of quantum interference is
+essential. We define the number of Floquet states which have large overlap with
+the initial state, and calculate its frequency dependence. The number of
+Floquet states shows approximately linear dependence on the frequency, when the
+frequency is small. Comparing the localization length in Floquet states and
+that in energy states from the viewpoint of the Anderson localization, we
+conclude that the Landau-Zener picture works for the local transition processes
+between levels.",0207038v1
+2002-12-13,Stable vortex and dipole vector solitons in a saturable nonlinear medium,"We study both analytically and numerically the existence, uniqueness, and
+stability of vortex and dipole vector solitons in a saturable nonlinear medium
+in (2+1) dimensions. We construct perturbation series expansions for the vortex
+and dipole vector solitons near the bifurcation point where the vortex and
+dipole components are small. We show that both solutions uniquely bifurcate
+from the same bifurcation point. We also prove that both vortex and dipole
+vector solitons are linearly stable in the neighborhood of the bifurcation
+point. Far from the bifurcation point, the family of vortex solitons becomes
+linearly unstable via oscillatory instabilities, while the family of dipole
+solitons remains stable in the entire domain of existence. In addition, we show
+that an unstable vortex soliton breaks up either into a rotating dipole soliton
+or into two rotating fundamental solitons.",0212034v1
+2004-01-12,Waveguiding properties of optical vortex solitons,"We study the properties of linear and nonlinear waveguides induced by optical
+vortex solitons in both self-defocusing and self-focusing nonlinear media, for
+the case of a saturable nonlinear response. We demonstrate that the
+vortex-induced waveguides can guide both fundamental and first-order guided
+modes which together with the vortex may form, for larger amplitudes of the
+guide modes, different types of composite vortex-mode vector solitons. In the
+case of the self-focusing saturable medium, we demonstrate that a
+large-amplitude guided mode can stabilize the ring-like vortex structure which
+usually decays due to azimuthal modulational instability.",0401013v1
+2005-11-01,Discrete soliton mobility in two-dimensional waveguide arrays with saturable nonlinearity,"We address the issue of mobility of localized modes in two-dimensional
+nonlinear Schr\""odinger lattices with saturable nonlinearity. This describes
+e.g. discrete spatial solitons in a tight-binding approximation of
+two-dimensional optical waveguide arrays made from photorefractive crystals. We
+discuss numerically obtained exact stationary solutions and their stability,
+focussing on three different solution families with peaks at one, two, and four
+neighboring sites, respectively. When varying the power, there is a repeated
+exchange of stability between these three solutions, with symmetry-broken
+families of connecting intermediate stationary solutions appearing at the
+bifurcation points. When the nonlinearity parameter is not too large, we
+observe good mobility, and a well defined Peierls-Nabarro barrier measuring the
+minimum energy necessary for rendering a stable stationary solution mobile.",0511003v2
+2006-10-24,Moving solitons in the discrete nonlinear Schrödinger equation,"Using the method of asymptotics beyond all orders, we evaluate the amplitude
+of radiation from a moving small-amplitude soliton in the discrete nonlinear
+Schr\""odinger equation. When the nonlinearity is of the cubic type, this
+amplitude is shown to be nonzero for all velocities and therefore
+small-amplitude solitons moving without emitting radiation do not exist. In the
+case of a saturable nonlinearity, on the other hand, the radiation is found to
+be completely suppressed when the soliton moves at one of certain isolated
+`sliding velocities'. We show that a discrete soliton moving at a general speed
+will experience radiative deceleration until it either stops and remains pinned
+to the lattice, or--in the saturable case--locks, metastably, onto one of the
+sliding velocities. When the soliton's amplitude is small, however, this
+deceleration is extremely slow; hence, despite losing energy to radiation, the
+discrete soliton may spend an exponentially long time travelling with virtually
+unchanged amplitude and speed.",0610059v4
+1998-12-11,Flow angle from intermediate mass fragment measurements,"Directed sideward flow of light charged particles and intermediate mass
+fragments was measured in different symmetric reactions at bombarding energies
+from 90 to 800 AMeV. The flow parameter is found to increase with the charge of
+the detected fragment up to Z = 3-4 and then turns into saturation for heavier
+fragments. Guided by simple simulations of an anisotropic expanding thermal
+source, we show that the value at saturation can provide a good estimate of the
+flow angle, $\Theta_{flow}$, in the participant region. It is found that
+$\Theta_{flow}$ depends strongly on the impact parameter. The excitation
+function of $\Theta_{flow}$ reveals striking deviations from the ideal
+hydrodynamical scaling. The data exhibit a steep rise of $\Theta_{\flow}$ to a
+maximum at around 250-400 AMeV, followed by a moderate decrease as the
+bombarding energy increases further.",9812005v1
+2002-02-08,Modeling of the saturation current of a fission chamber taking into account the distorsion of electric field due to space charge effects,"Fission chambers were first made fifty years ago for neutron detection. At
+the moment, the French Atomic Energy Commission \textsf{(CEA-Cadarache)} is
+developing a sub-miniature fission chamber technology with a diameter of 1.5 mm
+working in the current mode (Bign). To be able to measure intense fluxes, it is
+necessary to adjust the chamber geometry and the gas pressure before testing it
+under real neutron flux. In the present paper, we describe a theoretical method
+to foresee the current-voltage characteristics (sensitivity and saturation
+plateau) of a fission chamber whose geometrical features are given, taking into
+account the neutron flux to be measured (spectrum and intensity). The proposed
+theoretical model describes electric field distortion resulting from charge
+collection effect. A computer code has been developed on this model basis. Its
+application to 3 kinds of fission chambers indicates excellent agreement
+between theoretical model and measured characteristics.",0202004v1
+2003-05-13,Particle dependence of elliptic flow in Au+Au collisions at $\sqrt{s_{NN}}=$ 200 GeV,"The elliptic flow parameter ($v_2$) for $K_S^0$ and $\Lambda+\bar{\Lambda}$
+has been measured at mid-rapidity in Au + Au collisions at
+$\sqrt{s_{_{NN}}}=200$ GeV by the STAR collaboration. The $v_2$ values for both
+$K_S^{0}$ and $\Lambda+\bar{\Lambda}$ saturate at moderate $p_T$, deviating
+from the hydrodynamic behavior observed in the lower $p_T$ region. The
+saturated $v_2$ values and the $p_T$ scales where the deviation begins are
+particle dependent. The particle-type dependence of $v_2$ shows features
+expected from the hadronization of a partonic ellipsoid by coalescence of
+co-moving quarks. These results will be discussed in relation to the nuclear
+modification factor ($R_{CP}$) which has also been measured for $K_S^0$ and
+$\Lambda+\bar{\Lambda}$ by the STAR collaboration.",0305008v3
+2004-05-19,BRAHMS results in the context of saturation and quantum evolution,"We report BRAHMS results from RHIC d+Au and p+p collisions at
+Sqrt(s_NN)=200GeV. A remarkable change in the nuclear modification factor RdAu
+is seen as the pseudorapidity of the detected charged hadrons changes from zero
+at mid-rapidity to 3.2 at the most forward angle studied during the 2003 run.
+For pseudorapidity eta>1 the suppression of the Rcp factor is more pronounced
+in the sample of central events in contrast to the behavior at mid-rapidity
+where the central events show higher enhancement compared to the semi-central
+sample. These results are consistent with a saturated Au wave function strongly
+affected by quantum evolution at higher values of rapidity.",0405018v1
+2004-08-16,Pseudorapidity Asymmetry and Centrality Dependence of Charged Hadron Spectra in d+Au Collisions at $\sqrt{s_{NN}}=200$ GeV,"The pseudorapidity asymmetry and centrality dependence of charged hadron
+spectra in d+Au collisions at $\sqrt{s_{NN}}=200$ GeV are presented. The
+charged particle density at mid-rapidity, its pseudorapidity asymmetry and
+centrality dependence are reasonably reproduced by a Multi-Phase Transport
+model, by HIJING, and by the latest calculations in a saturation model. Ratios
+of transverse momentum spectra between backward and forward pseudorapidity are
+above unity for \pT below 5 GeV/$c$. The ratio of central to peripheral spectra
+in d+Au collisions shows enhancement at 2 $<$ \pT $<$ 6 GeV/$c$, with a larger
+effect at backward rapidity than forward rapidity. Our measurements are in
+qualitative agreement with gluon saturation and in contrast to calculations
+based on incoherent multiple partonic scatterings.",0408016v2
+2006-01-05,High pT Suppression in CuCu Collsions at 200 GeV/NN at RHIC,"Collisions between hadronic systems at relativistic energies provide a window
+on the small-x gluon distributions of fast moving nuclei. It has been predicted
+that gluon saturation effects will manifest themselves as a suppression in the
+transverse momentum (pT) distribution at a scale which is connected with the
+rapidity of the measured particles. Saturation effects are most evident at
+large (pseudo)-rapidity, i.e., at small angles relative to the beam direction.
+The dependence of the nuclear modification factor on the number of participants
+provides a constraint on the mechanism underlying the high-pT suppression. Here
+we present results for the nuclear modification factor Rcp at forward rapidity
+as a function of system mass comparing results from CuCu, AuAu and dAu
+collsions at 200 GeV/NN.",0601011v1
+1996-10-08,Nuclear Density-Dependent Effective Coupling Constants in the Mean-Field Theory,"It is shown that the equation of state of nuclear matter can be determined
+within the mean-field theory of $\sigma \omega$ model provided only that the
+nucleon effective mass curve is given. We use a family of the possible nucleon
+effective mass curves that reproduce the empirical saturation point in the
+calculation of the nuclear binding energy curves in order to obtain
+density-dependent effective coupling constants. The resulting density-dependent
+coupling constants may be used to study a possible equation of state of nuclear
+system at high density or neutron matter. Within the constraints used in this
+paper to $M^*$ of nuclear matter at saturation point and zero density, neutron
+matter of large incompressibility is strongly bound at high density while soft
+neutron matter is weakly bound at low density. The study also exhibits the
+importance of surface vibration modes in the study of nuclear equation of
+state.",9610010v1
+1996-12-10,Saturation properties and liquid-gas phase transition of nucleus,"Saturation properties and liquid-gas phase transition of nucleus are analysed
+in the framework of Hatree-Fock theory. We modify Hill-Wheller formula with a
+finite-size-effect parameter by fitting the zero-temperature properties of
+nucleus. Employing Gogny effective interaction and phenomenological expression
+of Coulomb energy, we give the critical temperature of liquid-gas phase
+transition of nucleus being about 12 MeV, which agrees with the result
+extracted from heavy-ion collision experiments. It is pointed out that a
+phenomenological formula of surface energy of hot nucleus is not avaliable in
+the region where nucleon density is far away from the normal density.",9612022v1
+1997-06-16,Strangeness and Pion Production as Signals of QCD Phase Transition,"A systematic analysis of data on strangeness and pion production in
+nucleon-nucleon and central nucleus-nucleus collisions is presented. It is
+shown that at all collision energies the pion/baryon and strangeness/pion
+ratios indicate saturation with the size of the colliding nuclei. The energy
+dependence of the saturation level suggests that the transition to the Quark
+Gluon Plasma occurs between 15 AGeV/c (BNL AGS) and 160 AGeV/c (CERN SPS)
+collision energies. The experimental results interpreted in the framework of a
+statistical approach show that the effective number of degrees of freedom
+increases in the course of the phase transition and that the plasma created at
+CERN SPS energies may have a temperature of about 280 MeV (energy density 10
+GeV/fm-3). The presence of the phase transition can lead to the non-monotonic
+collision energy dependence of the strangeness/pion ratio. After an initial
+increase the ratio should drop to the characteristic value for the QGP. Above
+the transition region the ratio is expected to be collision energy independent.
+Experimental studies of central Pb+Pb collisions in the energy range 20--160
+AGeV/c are urgently needed in order to localize the threshold energy, and study
+the properties of the QCD phase transition.",9706036v1
+1997-11-14,The role of tensor force in nuclear matter saturation,"Using a relativistic Dirac-Brueckner analysis the pion contribution to the
+ground state energy of nuclear matter is studied. Evidence is presented that
+the role of the tensor force in the saturation mechanism is substantially
+reduced compared to its dominant role in a usual non-relativistic treatment.
+The reduction of the pion contribution in nuclear matter is due to many-body
+effects present in a relativistic treatment. In particular, we show that the
+damping of OPEP is actually due to the decrease of $M^*/M$ with increasing
+density.",9711029v1
+1997-12-10,$Q^2$--Dependence of the Gerasimov-Drell-Hearn Sum Rule,"We test the Gerasimov-Drell-Hearn (GDH) sum rule numerically by calculating
+the total photon absorption cross sections $\sigma_{1/2}$ and $\sigma_{3/2}$ on
+the nucleon via photon excitation of baryon resonances in the constituent quark
+model. A total of seventeen, low-lying, non-strange baryon resonances are
+included in this calculation. The transverse and longitudinal interference
+cross section, $\sigma_{1/2}^{TL}$, is found to play an important role in the
+study of the $Q^2$ variation of the sum rule. The results show that the GDH sum
+rule is saturated by these resonances at a confidence level of 94%. In
+particular, the $P_{33}(1232)$ excitation largely saturates the sum rule at
+$Q^2 = 0$, and dominates at small $Q^2$. The GDH integral has a strong
+$Q^2$-dependence below $Q^2= 1.0 {GeV}^2$ and changes its sign around $Q^2= 0.3
+{GeV}^2$. It becomes weakly $Q^2$-dependent for $Q^2 > 1.0 {GeV}^2$ because of
+the quick decline of the resonance contributions. We point out that the $Q^2$
+variation of the GDH sum rule is very important for understanding the nucleon
+spin structure in the non-perturbative QCD region.",9712036v1
+2000-11-07,Nuclear matter properties in the relativistic mean field model with sigma-omega coupling,"The possibility of extending the linear sigma-omega model by introducing a
+sigma-omega coupling phenomenologically is explored. It is shown that, in
+contrast to the usual Walecka model, not only the effective nucleon mass M* but
+also the effective sigma meson mass m*_sigma and the effective omega meson mass
+m*_omega are nucleon density dependent. When the model parameters are fitted to
+the nuclear saturation point (the nuclear radius constant r_0=1.14fm and volume
+energy a_1=16.0MeV) as well as to the effective nucleon mass M*=0.85M, the
+model yields m*_sigma=1.09m_sigma and m*_omega=0.90m_omega at the saturation
+point, and the nuclear incompressibility K_0=501MeV. The lowest value of K_0
+given by this model by adjusting the model parameters is around 227MeV.",0011025v1
+2001-04-24,Saturation of Elliptic Flow and the Transport Opacity of the Gluon Plasma at RHIC,"Differential elliptic flow and particle spectra are calculated taking into
+account the finite transport opacity of the gluon plasma produced in Au+Au at
+Ecm ~ 130 A GeV at RHIC. Covariant numerical solutions of the ultrarelativistic
+Boltzmann equation are obtained using the MPC parton cascade technique. For
+typical pQCD (~3 mb) elastic cross sections, extreme initial gluon densities,
+dN/deta ~ 15000, are required to reproduce the elliptic flow saturation pattern
+reported by STAR. However, we show that the solutions depend mainly on the
+transport opacity, $\chi=\int dz \sigma_t\rho_g$, and thus the data can also be
+reproduced with dN/deta ~ 1000, but with extreme elastic parton cross sections,
+\~45 mb. We demonstrate that the spectra and elliptic flow are dominated by
+numerical artifacts unless parton subdivisions ~100-1000 are applied to retain
+Lorentz covariance for RHIC initial conditions.",0104073v3
+2002-05-30,Energy dependence of string fragmentation function and $φ$ meson production,"The $\phi$ meson productions in $Au+Au$ and/or $Pb+Pb$ collisions at AGS,
+SPS, RHIC, and LHC energies have been studied systematically with a hadron and
+string cascade model LUCIAE. After considering the energy dependence of the
+model parameter $\alpha$ in string fragmentation function and adjusting it to
+the experimental data of charged multiplicity to a certain extent, the model
+predictions for $\phi$ meson yield, rapidity, and/or transverse mass
+distributions are compatible with the experimental data at AGS, SPS and RHIC
+energies. A calculation for $Pb+Pb$ collisions at LHC energy is given as well.
+The obtained fractional variable in string fragmentation function shows a
+saturation in energy dependence. It is discussed that the saturation of
+fractional variable in string fragmentation function might be a qualitative
+representation of the energy dependence of nuclear transparency.",0205078v1
+2002-10-04,The structure of nuclear systems derived from low momentum nucleon-nucleon potentials,"Various nuclear structure observables are evaluated employing low-momentum
+nucleon-nucleon (NN) potentials $V_{\rm low-k}$ derived from the CD-Bonn and
+Nijmegen NN interactions $V_{NN}$. By construction, the high momentum modes of
+the original $V_{NN}$ are integrated out in $V_{\rm low-k}$, with the
+requirement that the deuteron binding energy and low energy phase shifts of
+$V_{NN}$ are exactly reproduced. Using this interaction, we evaluate the bulk
+properties (binding energy and saturation density) of nuclear matter and finite
+nuclei, in particular their dependence on the cut-off parameter. We also study
+the pairing gap and the residual interaction in nuclear matter in terms of the
+Landau parametrization. At low and medium densities, the HF and BHF binding
+energies for nuclear matter calculated with the $V_{\rm low-k}$'s derived from
+the CD-Bonn and Nijmegen potentials are nearly identical. The pairing gaps and
+Landau parameters derived from $V_{\rm low-k}$ are remarkably close to those
+given by the full-space $V_{NN}$. The $V_{\rm low-k}$ interactions, however,
+fail to reproduce the saturation property of nuclear matter at higher densities
+if the cut-off for the high momentum modes is assumed density independent.",0210010v1
+2003-04-28,An interpretation of saturation phenomena as Glauber-Gribov multiple parton scatterings,"We compare two formalism that describe minijet production in pA and AA
+collisions: pQCD supplemented by Glauber-Gribov multiple semihard parton
+scatterings (pQCD+Glauber), and the Colour Glass Condensate (CGC). We argue
+that in a suitable limit they are equivalent to each other, the PQCD+Glauber
+model being more accurate from a numerical point of view. Finally, we analyze
+RHIC data on Au-Au integrated charged multiplicities in the pQCD+Glauber
+framework, and conclude that at least at central rapidity there is no sign of
+gluon saturation.",0304083v1
+2003-05-18,Meson and baryon elliptic flow at high pT from parton coalescence,"The large and saturating differential elliptic flow v2(pT) observed in Au+Au
+reactions at RHIC so far could only be explained assuming an order of magnitude
+denser initial parton system than estimated from perturbative QCD.
+Hadronization via parton coalescence can resolve this ``opacity puzzle''
+because it enhances hadron elliptic flow at large pT relative to that of
+partons at the same transverse momentum. An experimentally testable consequence
+of the coalescence scenario is that v2(pT) saturates at about 50% higher values
+for baryons than for mesons. In addition, if strange quarks have weaker flow
+than light quarks, hadron v2 at high pT decreases with relative strangeness
+content.",0305049v1
+2003-08-27,Nuclear incompressibility using the density dependent M3Y effective interaction,"A density dependent M3Y effective nucleon-nucleon (NN) interaction which was
+based on the G-matrix elements of the Reid-Elliott NN potential has been used
+to determine the incompressibity of infinite nuclear matter. The nuclear
+interaction potential obtained by folding in the density distribution functions
+of two interacting nuclei with this density dependent M3Y effective interaction
+had been shown earlier to provide excellent descriptions for medium and high
+energy $\alpha$ and heavy ion elastic scatterings as well as $\alpha$ and heavy
+cluster radioactivities. The density dependent parameters have been chosen to
+reproduce the saturation energy per nucleon and the saturation density of spin
+and isospin symmetric cold infinite nuclear matter. The result of such
+calculations for nuclear incompressibility using the density dependent M3Y
+effective interaction based on the G-matrix elements of Reid-Elliott NN
+potential predicts a value of about 300 MeV for nuclear incompressibility.",0308075v1
+2004-04-29,Kaon and antikaon properties in cold nuclear medium,"We present results of a self-consistent calculation for the kaon and antikaon
+spectral functions in cold nuclear matter, using as input the kaon-nucleon and
+antikaon-nucleon scattering amplitudes of the vacuum. We investigate the effect
+of in-medium pion dressing on the antikaon-nucleon scattering amplitudes and
+antikaon spectral function. We find the influence of pion dressing to be minor
+on the antikaon spectral function and limited on the hyperon resonances causing
+only a small additional broadening. An exception is the \Sigma(1690). At
+nuclear saturation density an attractive mass shift of about 20 MeV and width
+of about 130 MeV is obtained. The kaon shows a repulsive mass increase of 36
+MeV and a small width of the quasiparticle peak at saturation density.",0404088v2
+2005-09-25,A statistical model analysis of yields and fluctuations in 200 GeV Au-Au collisions,"We show that the simultaneous measurement of yields and fluctuations is
+capable of falsifying and constraining the statistical hadronization model. We
+show how such a measurement can test for chemical non-equilibrium, and
+distinguish between a high temperature chemically equilibrated freeze-out from
+a supercooled freeze-out with an over-saturated phase space. We perform a fit,
+and show that both yields and fluctuations measured at RHIC 200 GeV can be
+accounted for within the second scenario, with both the light and strange quark
+phase space saturated significantly above detailed balance. We point to the
+simultaneous fit of the $K/\pi$ fluctuation and the $K^*/K^-$ ratio as evidence
+that the effect of hadronic re-interactions after freeze-out is small.",0509067v1
+2006-03-31,High density behaviour of nuclear symmetry energy,"Role of the isospin asymmetry in nuclei and neutron stars, with an emphasis
+on the density dependence of the nuclear symmetry energy, is discussed. The
+symmetry energy is obtained using the isoscalar as well as isovector components
+of the density dependent M3Y effective interaction. The constants of density
+dependence of the effective interaction are obtained by reproducing the
+saturation energy per nucleon and the saturation density of spin and isospin
+symmetric cold infinite nuclear matter. Implications for the density dependence
+of the symmetry energy in case of a neutron star are discussed, and also
+possible constraints on the density dependence obtained from finite nuclei are
+compared.",0603073v2
+2006-04-17,Gluon Saturation Effects in Relativistic U+U Collisions,"We examine entropy production in relativistic U+U collisions on the basis of
+a Color Glass Condensate (CGC) type picture as implemented in the
+Kharzeev-Levin-Nardi model (KLN). In this framework, we find that the peak
+entropy density produced in tip-on-tip U+U collisions is about 30% greater than
+that seen in central Au+Au collisions. Although the resulting difference in the
+produced charged particle multiplicity between tip-on-tip and side-on-side
+collisions is smaller than that predicted by previous Glauber model estimates,
+it is still large enough to allow for experimental discrimination between
+average orientations of the uranium nuclei. We also point out that in the
+saturation/CGC approach the collision geometry plays a more important role than
+previously believed, and that the observed centrality dependence of the
+produced particle multiplicity per participant in Au+Au collisions can be
+qualitatively reproduced even without running coupling effects.",0604038v1
+2006-11-13,QCD susceptibilities and nuclear matter saturation in a chiral theory: inclusion of pion loops,"We derive the equation of state of symmetric nuclear matter in a relativistic
+theory with $\sigma$ and $\omega$ exchange. We take a chiral version of this
+model which insures all the chiral constraints. Going beyond the mean field
+approach we introduce the effects of the pion loops. For the parameters of the
+model, in order to fix those linked to pion exchange, we exploit the most
+recent information on the short-range part of the spin-isospin interaction. For
+those linked to the scalar meson exchange we make use of an analysis of lattice
+results on the nucleon mass evolution with the quark mass. With these inputs we
+are able reach a correct description of the saturation properties. From the
+equation of state of symmetric nuclear matter we alsoderive the density
+dependence of the quark condensate and of the QCD susceptibilities.",0611042v1
+2007-03-09,From QCD to nuclear matter saturation,"We discuss a relativistic chiral theory of nuclear matter with $\sigma$ and
+$\omega$ exchange using a formulation of the $\sigma$ model in which all the
+chiral constraints are automatically fulfilled. We establish a relation between
+the nuclear response to the scalar field and the QCD one which includes the
+nucleonic parts. It allows a comparison between nuclear and QCD information.
+Going beyond the mean field approach we introduce the effects of the pion loops
+supplemented by the short-range interaction. The corresponding Landau-Migdal
+parameters are taken from spin-isospin physics results. The parameters linked
+to the scalar meson exchange are extracted from lattice QCD results. These
+inputs lead to a reasonable description of the saturation properties,
+illustrating the link between QCD and nuclear physics. We also derive from the
+corresponding equation of state the density dependence of the quark condensate
+and of the QCD susceptibilities.",0703022v1
+2007-03-23,Phase transitions in isolated strongly interacting systems,"Thermodynamical properties of the nuclear matter at sub-saturation densities
+were investigated using a simple van der Waals-like equation of state with an
+additional term representing the symmetry energy. First-order
+isospin-asymmetric liquid-gas phase transition appears restricted to isolated
+isospin-asymmetric systems while the symmetric systems will undergo
+fragmentation decay resembling the second-order phase transition. The density
+dependence of the symmetry energy scaling with the Fermi energy satisfactorily
+describes the symmetry energy at sub-saturation nuclear densities. The
+deconfinement-confinement phase transition from the quark-gluon plasma to the
+confined quark matter appears in the isolated systems continuous in energy
+density while discontinuous in quark density. A transitional state of the
+confined quark matter has a negative pressure and after hadronization an
+explosion scenario can take place which can offer explanation for the HBT
+puzzle as a signature of the phase transition.",0703077v2
+1997-08-21,Amplitude equations for coupled electrostatic waves in the limit of weak instability,"We consider the simplest instabilities involving multiple unstable
+electrostatic plasma waves corresponding to four-dimensional systems of mode
+amplitude equations. In each case the coupled amplitude equations are derived
+up to third order terms. The nonlinear coefficients are singular in the limit
+in which the linear growth rates vanish together. These singularities are
+analyzed using techniques developed in previous studies of a single unstable
+wave. In addition to the singularities familiar from the one mode problem,
+there are new singularities in coefficients coupling the modes. The new
+singularities are most severe when the two waves have the same linear phase
+velocity and satisfy the spatial resonance condition $k_2=2k_1$. As a result
+the short wave mode saturates at a dramatically smaller amplitude than that
+predicted for the weak growth rate regime on the basis of single mode theory.
+In contrast the long wave mode retains the single mode scaling. If these
+resonance conditions are not satisfied both modes retain their single mode
+scaling and saturate at comparable amplitudes.",9708004v1
+1998-04-28,The Dynamics of Granular Segregation Patterns in a Long Drum Mixer,"We have studied the early time evolution of granular segregation patterns in
+a horizontal rotating cylinder partially filled with a sand/salt mixture. The
+growth of concentration fluctuations starting from premixed initial conditions
+was analyzed using Fourier techniques. In one mixture, we observed generally
+merging dynamics in the segregated bands up to the onset of saturation. At the
+threshold of saturation, we found a spectrum of wavelengths with a broad peak.
+The peak position was nearly independent of the tube rotation rate. The overall
+growth rate of Fourier modes had a maximum at a particular value of the angular
+rotation frequency. In a slightly different mixture, we observed transient
+traveling waves when the larger grains were in the majority. We measured the
+wave speed as a function of several parameters using presegregated initial
+conditions to launch waves of various wavelengths.",9804004v2
+2000-12-31,Spectral Characteristics of Ultrashort Pulses in Kerr-lens Mode-Locked Lasers,"A number of factors that influence spectral position of the femtosecond pulse
+in a Kerr-lens modelocked Cr:LiSGaF laser have been identified: high-order
+dispersion, gain saturation, reabsorption from the ground state, and stimulated
+Raman scattering. Using the one-dimensional numerical model for the simulation
+of the laser cavity, the relative contributions of different factors have been
+compared. The Raman effect provides the largest self-frequency shift from the
+gain peak (up to 60 nm), followed by the gain saturation (25 nm), while the
+high-order dispersion contribution is insignificant (5 nm). Comparison with the
+experimental data confirm that the stimulated Raman scattering is a main cause
+of the ultrashort pulse self-frequency shift observed in Cr:LiSGaF and Cr:LiSAF
+lasers",0101004v2
+2002-07-31,Drift Wave versus Interchange Turbulence in Tokamak Geometry: Linear versus Nonlinear Mode Structure,"The competition between drift wave and interchange physics in general
+E-cross-B drift turbulence is studied with computations in three dimensional
+tokamak flux tube geometry. For a given set of background scales, the parameter
+space can be covered by the plasma beta and drift wave collisionality. At large
+enough plasma beta the turbulence breaks out into ideal ballooning modes and
+saturates only by depleting the free energy in the background pressure
+gradient. At high collisionality it finds a more gradual transition to
+resistive ballooning. At moderate beta and collisionality it retains drift wave
+character, qualitatively identical to simple two dimensional slab models. The
+underlying cause is the nonlinear vorticity advection through which the self
+sustained drift wave turbulence supersedes the linear instabilities, scattering
+them apart before they can grow, imposing its own physical character on the
+dynamics. This vorticity advection catalyses the gradient drive, while
+saturation occurs solely through turbulent mixing of pressure disturbances.
+This situation persists in the whole of tokamak edge parameter space. Both
+simplified isothermal models and complete warm ion models are treated.",0207126v1
+2003-12-11,Influence of squirt flow on fundamental guided waves propagation in borehole embedded in saturated porous media,"In this paper, the reservoir is modeled by homogeneous two-phase media based
+on BISQ model. We focus on the effects of the squirt flow on the fundamental
+guided waves propagation in borehole embedded in saturated porous media excited
+by monopole, dipole and quadrupole point sources. The full waveforms acoustic
+logging in a fluid-filled borehole are simulated. The curves of velocity
+dispersion, attenuation coefficients and excitation of the fundamental guided
+waves have shown that velocity dispersions are almost independent of the
+characteristic squirt flow length, attenuations of guided waves are enhanced
+due to the squirt flow, and excitations of guided waves are decreased due to
+the squirt flow. It is possible to estimate the characteristic squirt flow
+length by attenuation coefficients of the guided waves from acoustical logging
+data.",0312069v2
+2004-01-15,Nonlinear Variation of Light-Pressure-Induced Multilevel Atomic Line Shifts with Vapor Pressure in Helium Spectroscopy,"This paper has been temporarily withdrawn. Highly nonlinear dependences of
+4He 2^3S - 2^3P lines on pressure were observed in vapor cell saturation
+spectroscopy. Line shifts agree with those expected from light-pressure-induced
+perturbation of atomic velocity distribution. In the lin-perp-lin pump and
+probe polarization configuration, multilevel atomic structure must be taken
+into account. For a two-level atom, the shift magnitude is determined by the
+collisional time constant, but when the system has dark states there is an
+additional time constant due to optical pumping. The collisional and optical
+time constants compete, and become equal at a certain pressure p_0. Saturation
+signal vanishes at p_0 whereas signal due to light pressure remains. This leads
+to a dependence of line centers on pressure that exhibits apparently singular
+behavior at p_0. The 2S - 2P(J=1) line shift reaches the natural half width.
+Vapor cells may be more suitable for investigation of this effect than atomic
+beams since the shifts vanish at sufficiently high pressures. Two ways of
+controlling the shifts for the helium 2P fine structure measurement are
+discussed.",0401075v2
+2004-08-03,Absence of saturation for finite injected currents in axially symmetric cavity diode,"The Child-Langmuir law is investigated numerically using a fully
+electromagnetic particle-in-cell code for a closed axially symmetric diode. It
+is found that the average current transmitted to the anode increases with the
+injected current even after the formation of virtual cathode in both the
+non-relativistic and relativistic cases. The increase is found to be a power
+law. In other words, the time averaged fraction $f$ of electrons reaching the
+anode varies with the input current as, $f\sim J_{\rm IN}^{-\beta}$ where
+$\beta < 1$. In contrast, for an infinite parallel plate diode, $f \sim J_{\rm
+IN}^{-1}$. The possibility of asymptotic saturation is also discussed.",0408014v1
+2004-09-16,Criteria for the experimental observation of multi-dimensional optical solitons in saturable media,"Criteria for experimental observation of multi-dimensional optical solitons
+in media with saturable refractive nonlinearities are developed. The criteria
+are applied to actual material parameters (characterizing the cubic
+self-focusing and quintic self-defocusing nonlinearities, two-photon loss, and
+optical-damage threshold) for various glasses. This way, we identify operation
+windows for soliton formation in these glasses. It is found that two-photon
+absorption sets stringent limits on the windows. We conclude that, while a
+well-defined window of parameters exists for two-dimensional solitons (spatial
+or spatiotemporal), for their three-dimensional spatiotemporal counterparts
+such a window \emph{does not} exist, due to the nonlinear loss in glasses.",0409081v1
+2004-10-01,Saturation of Cs2 Photoassociation in an Optical Dipole Trap,"We present studies of strong coupling in single-photon photoassociation of
+cesium dimers using an optical dipole trap. A thermodynamic model of the trap
+depletion dynamics is employed to extract absolute rate coefficents. From the
+dependence of the rate coefficient on the photoassociation laser intensity, we
+observe saturation of the photoassociation scattering probability at the
+unitarity limit in quantitative agreement with the theoretical model by Bohn
+and Julienne [Phys. Rev. A, 60, 414 (1999)]. Also the corresponding power
+broadening of the resonance width is measured. We could not observe an
+intensity dependent light shift in contrast to findings for lithium and
+rubidium, which is attributed to the absence of a p or d-wave shape resonance
+in cesium.",0410006v1
+2005-09-20,Properties of the odd harmonics of the radiation from SASE FEL with a planar undulator,"Recent theoretical and experimental studies have shown that Self-Amplified
+Spontaneous Emission Free Electron Laser (SASE FEL) with a planar undulator
+holds a potential for generation of relatively strong coherent radiation at the
+third harmonic of the fundamental frequency. Here we present detailed study of
+the nonlinear harmonic generation in the SASE FEL obtained with time-dependent
+FEL simulation code. Using similarity techniques we present universal
+dependencies for temporal, spectral, and statistical properties of the odd
+harmonics of the radiation from SASE FEL. In particular, we derived universal
+formulae for radiation power of the odd harmonics at saturation. It was also
+found that coherence time at saturation falls inversely proportional to
+harmonic number, and relative spectrum bandwidth remains constant with harmonic
+number.",0509164v1
+2005-09-22,"Saturable Absorber, Coherent Population Oscillations, and ""Slow Light""","The paper presents a critical analysis of publications devoted to one of the
+methods for production of the so-called ""slow light"" (the light with an
+anomalously low group velocity) due to extremely high local steepness of the
+dispersion curve of the medium. The method in point employs for this purpose
+the effect of coherent population oscillations accompanied by burning of a
+narrow spectral hole in the homogeneously broadened absorption spectrum.
+Physical model of the effect proposed in the studies under consideration is
+based on analysis of response of a nonlinear medium to a low-frequency
+intensity modulation of the incident light beam. We show that all the
+observations described in these papers can be easily interpreted in the
+framework of the simplest model of saturable absorber and have nothing to do
+with the effects of hole burning and group velocity reduction.",0509181v1
+2005-09-28,A High Temperature Calcium Vapor Cell for Spectroscopy on the 4s^2 1S0 to 4s4p 3P1 Intercombination Line,"We have demonstrated a high temperature vapor cell for absorption
+spectroscopy on the Ca intercombination line. The cell uses a dual chamber
+design to achieve the high temperatures necessary for an optically dense vapor
+while avoiding the necessity of high temperature vacuum valves and
+glass-to-metal seals. We have observed over 50 percent absorption in a single
+pass through the cell. Although pressure broadening in the cell prevented us
+from performing saturated-absorption spectroscopy, the broadening resulted in
+higher signal-to-noise ratios by allowing us to probe the atoms with
+intensities much greater than the 0.2 uW/cm^2 saturation intensity of the
+unbroadened transition.",0509239v1
+1997-01-09,Systematic and statistical errors in homodyne measurements of the density matrix,"We study both systematic and statistical errors in radiation density matrix
+measurements. First we estimate the minimum number of scanning phases needed to
+reduce systematic errors below a fixed threshold. Then, we calculate the
+statistical errors, intrinsic in the procedure that gives the density matrix.
+We present a detailed study of such errors versus the detectors quantum
+efficiency $\eta$ and the matrix indexes in the number representation, for
+different radiation states. For unit quantum efficiency, and for both coherent
+and squeezed states, the statistical errors of the diagonal matrix elements
+saturate for large n. On the contrary, off-diagonal errors increase with the
+distance from the diagonal. For non unit quantum efficiency the statistical
+errors along the diagonal do not saturate, and increase dramatically versus
+both $1-\eta$ and the matrix indexes.",9701010v1
+2003-04-14,Ground state entanglement in quantum spin chains,"A microscopic calculation of ground state entanglement for the XY and
+Heisenberg models shows the emergence of universal scaling behavior at quantum
+phase transitions. Entanglement is thus controlled by conformal symmetry. Away
+from the critical point, entanglement gets saturated by a mass scale. Results
+borrowed from conformal field theory imply irreversibility of entanglement loss
+along renormalization group trajectories. Entanglement does not saturate in
+higher dimensions which appears to limit the success of the density matrix
+renormalization group technique. A possible connection between majorization and
+renormalization group irreversibility emerges from our numerical analysis.",0304098v4
+2004-08-30,Quantum correlations in bound-soliton pairs and trains in fiber lasers,"Quantum correlations in pairs and arrays (trains) of bound solitons modeled
+by the complex Ginzburg-Landau equation (CGLE) are calculated numerically, on
+the basis of linearized equations for quantum fluctuations. We find strong
+correlations between the bound solitons, even though the system is dissipative.
+Some degree of the correlation between the photon-number fluctuations of stable
+bound soliton pairs and trains is attained and saturates after passing a
+certain distance. The saturation of the photon-number correlations is explained
+by the action of non- conservative terms in the CGLE. Photon-number-correlated
+bound soliton trains offer novel possibilities to produce multipartite
+entangled sources for quantum communication and computation.",0408175v1
+2005-11-09,Phase time for a tunneling particle,"We study the nature of tunneling phase time for various quantum mechanical
+structures such as networks and rings having potential barriers in their arms.
+We find the generic presence of Hartman effect, with superluminal velocities as
+a consequence, in these systems. In quantum networks it is possible to control
+the `super arrival' time in one of the arms by changing the parameters on
+another arm which is spatially separated from it. This is yet another quantum
+nonlocal effect. Negative time delays (time advancement) and `ultra Hartman
+effect' with negative saturation times have been observed in some parameter
+regimes. In presence and absence of Aharonov-Bohm (AB) flux quantum rings show
+Hartman effect. We obtain the analytical expression for the saturated phase
+time. In the opaque barrier regime this is independent of even the AB flux
+thereby generalizing the Hartman effect. We also briefly discuss the concept of
+""space collapse or space destroyer"" by introducing a free space in between two
+barriers covering the ring. Further we show in presence of absorption the
+reflection phase time exhibits Hartman effect in contrast to the transmission
+phase time.",0511089v1
+2007-01-05,Quantum jumps of saturation level rigidity and anomalous oscillations of level number variance in the semiclassical spectrum of a modified Kepler problem,"We discover quantum Hall like jumps in the saturation spectral rigidity in
+the semiclassical spectrum of a modified Kepler problem as a function of the
+interval center. These jumps correspond to integer decreases of the radial
+winding numbers in classical periodic motion. We also discover and explain
+single harmonic dominated oscillations of the level number variance with the
+width of the energy interval. The level number variance becomes effectively
+zero for the interval widths defined by the frequency of the shortest periodic
+orbit. This signifies that there are virtually no variations from sample to
+sample in the number of levels on such intervals.",0701023v1
+2007-03-20,Atom-wall dispersive forces from master equation formalism,"Using the general expressions for level shifts obtained from the master
+equation for a small system interacting with a large one considered as a
+reservoir, we calculate the dispersive potentials between an atom and a wall in
+the dipole approximation. We analyze in detail the particular case of a
+two-level atom in the presence of a perfectly conducting wall. We study the van
+der Waals as well as the resonant interactions. All distance regimes as well as
+the high and low temperature regimes are considered. We show that the
+Casimir-Polder interaction can not be considered as a direct result of the
+vacuum fluctuations only. Concerning the interaction between the atom and the
+wall at high temperature, which show that a saturation of the potential for all
+distances occurs. This saturated potential coincides exactly with that obtained
+in the London-van der Waals limit.",0703186v1
+2007-04-02,Causal dissipative hydrodynamics for QGP fluid in 2+1 dimensions,"In 2nd order causal dissipative theory, space-time evolution of QGP fluid is
+studied in 2+1 dimensions. Relaxation equations for shear stress tensors are
+solved simultaneously with the energy-momentum conservation equations.
+Comparison of evolution of ideal and viscous QGP fluid, initialized under the
+same conditions, e.g. same equilibration time, energy density and velocity
+profile, indicate that in a viscous dynamics, energy density or temperature of
+the fluid evolve slowly, than in an ideal fluid. Cooling gets slower as
+viscosity increases. Transverse expansion also increases in a viscous dynamics.
+For the first time we have also studied elliptic flow of 'quarks' in causal
+viscous dynamics. It is shown that elliptic flow of quarks saturates due to
+non-equilibrium correction to equilibrium distribution function, and can not be
+mimicked by an ideal hydrodynamics.",0704.0134v2
+2007-04-18,Multiple quantum wells for passive ultra short laser pulse generation,"Solid state lasers are demanding independent control in the gain media and
+cavity loss to achieve ultra short laser pulses using passive mode-locking.
+Recently, laser mode-locking is achieved with a MBE structure with multiple
+quantum wells, designed to achieve two functions; Bragg mirror and changes in
+absorption to control the cavity dynamics. The use of an AlGaAs/AlAs Bragg
+mirror with a 15 nm GaAs saturable absorber used in a Cr:LiSAF tuneable laser
+proved to be effective to produce femtosecond pulses. The use of saturable
+absorbers thus far is a trial and error procedure that is changing due to the
+correlation with more predictive procedures.",0704.2437v1
+2007-04-19,Average $p_t$ as a probe of high energy QCD dynamics,"Average transverse momentum of hadrons produced in high energy collisions is
+proposed as a diagnostic probe of high density (saturation) physics. We show
+that by introducing and varying a transverse momentum cutoff in the definition
+of the average transverse momentum, one can eliminate the uncertainty in the
+overall magnitude of the leading order hadron production cross section in high
+energy collisions, and semi-quantitatively map the different dynamical regions
+predicted by the saturation physics. We discuss the applications of this method
+to pion production at RHIC and LHC and make quantitative predictions for the
+average transverse momentum of produced pions in the kinematics appropriate for
+the RHIC and LHC experiments.",0704.2628v1
+2007-05-10,Manifestations of fine features of the density of states in the transport properties of KOs2O6,"We performed high-pressure transport measurements on high-quality single
+crystals of KOs2O6, a beta-pyrochlore superconductor. While the resistivity at
+high temperatures might approach saturation, there is no sign of saturation at
+low temperatures, down to the superconducting phase. The anomalous resistivity
+is accompanied by a nonmetallic behavior in the thermoelectric power (TEP) up
+to temperatures of at least 700 K, which also exhibits a broad hump with a
+maximum at 60 K. The pressure influences mostly the low-energy electronic
+excitations. A simple band model based on enhanced density of states in a
+narrow window around the Fermi energy (EF) explains the main features of this
+unconventional behavior in the transport coefficients and its evolution under
+pressure.",0705.1401v1
+2007-05-22,Study of sediment transport in the saltation regime,"We present a study of sediment transport in the creeping and saltation
+regime. In our model, a bed of particles is simulated with the conventional
+event-driven method. The particles are considered as hard disks in a 2d domain,
+with periodic boundary conditions in horizontal direction. The flow of the
+fluid over this bed of particles is modeled by imposing a force on each
+particle that depends on the velocity of the fluid and its height above the
+bed. We considered two velocity profiles for the fluid, parabolic and
+logarithmic. The first one models laminar flow and the second corresponds to
+turbulent flow. For each case we investigated the behavior of the saturated
+flux. We found that for the logarithmic profile, the saturated flux shows a
+quadratic increase with the strength of the flow, and for parabolic profile, a
+cubic increase. The velocity distribution functions are used to interpret the
+results.",0705.3143v1
+2007-06-01,Effect of Electron Interaction on Statistics of Conductance Oscillations in Open Quantum Dots: Does the Dephasing Time Saturate?,"We perform self-consistent quantum transport calculations in open quantum
+dots taking into account the effect of electron interaction. We demonstrative
+that in the regime of the ultralow temperatures $2\pi k_BT\lesssim\Delta$
+($\Delta $ being the mean level spacing), the electron interaction strongly
+affects the conductance oscillations and their statistics leading to a drastic
+deviation from the corresponding predictions for noninteracting electrons. In
+particular, it causes smearing of conductance oscillations, which is similar to
+the effect of temperature or inelastic scattering. For $2\pi k_BT\gtrsim\Delta$
+the influence of electron interaction on the conductance becomes strongly
+diminished. Our calculations (that are free from phenomenological parameters of
+the theory) are in good quantitative agreement with the observed ultralow
+temperature statistics (Huibers \textit{et al.}, Phys. Rev. Lett. \textbf{81},
+1917 (1998)). Our findings question a conventional interpretation of the
+ultralow temperature saturation of the coherence time in open dots which is
+based on the noninteracting theories where the electron interaction is
+neglected and the agrement with the experiment is achieved by introducing
+additional phenomenological channels of dephasing.",0706.0125v1
+2007-06-04,High-Dispersion Optical Spectra of Nearby Stars Younger Than The Sun,"We present high-dispersion (R~16,000) optical (3900-8700 A) spectra of 390
+stars obtained with the Palomar 60 inch telescope. The majority of stars
+observed are part of the Spitzer Legacy Science Program ""The Formation and
+Evolution of Planetary Systems."" Through detailed analysis we determine stellar
+properties for this sample, including radial and rotational velocities, Li I
+6708 and Ha equivalent widths, the chromospheric activity index R'_HK, and
+temperature- and gravity-sensitive line ratios. Several spectroscopic binaries
+are also identified. From our tabulations, we illustrate basic age- and
+rotation-related correlations among measured indices. One novel result is that
+Ca II chromospheric emission appears to saturate at vsini values above ~30
+km/s, similar to the well established saturation of X-rays that originate in
+the spatially separate coronal regions.",0706.0542v1
+2007-06-07,Simulation of symmetric nuclei and the role of Pauli potential in binding energies and radii,"It is shown that the use of a density dependent effective Pauli potential
+together with a nucleon-nucleon interaction potential plays a crucial role to
+reproduce not only the binding energies but also the matter root mean square
+radii of medium mass range spin-isospin saturated nuclei. This study is
+performed with a semiclassical Monte Carlo many-body simulation within the
+context of a simplified nucleon-nucleon interaction to focus on the effect of
+the genuine correlations due to the fermionic nature of nucleons. The procedure
+obtained is rather robust and it does not depend on the detailed features of
+the nucleon-nucleon interaction. For nuclei below saturation the density
+dependence may be represented in terms either of the nucleon number, $A$, or
+the associated Fermi momenta. When testing the simulation procedure for
+idealized ""infinite"" symmetric nuclear matter within the corresponding range of
+densities, it turns out that finite size effects affect the Pauli potential
+strength parametrization in systems up to about 120 particles while remaining
+approximately stable for larger systems.",0706.0958v2
+2007-06-28,Free flux flow magneto-resistance of single crystal BSCCO,"Measurement of the free flux flow resistance in monocrystalline highly
+anisotropic BSCCO reveals a low field magneto-resistive effect nearly 100 times
+that expected from a naive application of the Bardeen-Stephen rule R/Rn =
+B/Bc2. Furthermore in the vortex solid phase it saturates to a constant value
+at about Hc2/100 as if the vortices were moving 100 times faster than expected.
+An attempt to account for this behavior by a combination of sheared planar
+vortex flow obeying the BS rule and the quasi-particle c axis conductivity
+between the Josephson coupled superconducting planes is only partially
+successful. In particular it is unable to account for the saturation feature
+which occurs in both optimally and underdoped samples in the low temperature
+vortex solid phase.",0706.4261v1
+2007-07-16,Constraining interacting dark energy models with flux destabilization,"A destabilization in the transfer energy flux from the vacuum to radiation,
+for two vacuum decay laws relevant to the dark energy problem, is analyzed
+using the Landau-Lifshitz fluctuation hydrodynamic theory. Assuming thermal (or
+near thermal) equilibrium between the vacuum and radiation, at the earliest
+epoch of the Universe expansion, we show that the law due to
+renormalization-group running of the cosmological constant term, with
+parameters chosen not to spoil the primordial nucleosynthesis scenario, does
+soon drive the flux to fluctuate beyond its statistical average value thereby
+distorting the cosmic background radiation spectrum beyond observational
+limits. While the law coming from the saturated holographic dark energy does
+not lead the flux to wildly fluctuate, a more realistic non--saturated form
+shows again such anomalous behavior.",0707.2299v2
+2007-07-30,Heating and Turbulence Driving by Galaxy Motions in Galaxy Clusters,"Using three-dimensional hydrodynamic simulations, we investigate heating and
+turbulence driving in an intracluster medium (ICM) by orbital motions of
+galaxies in a galaxy cluster. We consider Ng member galaxies on isothermal and
+isotropic orbits through an ICM typical of rich clusters. An introduction of
+the galaxies immediately produces gravitational wakes, providing perturbations
+that can potentially grow via resonant interaction with the background gas.
+When Ng^{1/2}Mg_11 < 100, where Mg_11 is each galaxy mass in units of 10^{11}
+Msun, the perturbations are in the linear regime and the resonant excitation of
+gravity waves is efficient to generate kinetic energy in the ICM, resulting in
+the velocity dispersion sigma_v ~ 2.2 Ng^{1/2}Mg_11 km/s. When Ng^{1/2}Mg_11 >
+100, on the other hand, nonlinear fluctuations of the background ICM destroy
+galaxy wakes and thus render resonant excitation weak or absent. In this case,
+the kinetic energy saturates at the level corresponding to sigma_v ~ 220 km/s.
+The angle-averaged velocity power spectra of turbulence driven in our models
+have slopes in the range of -3.7 to -4.3. With the nonlinear saturation of
+resonant excitation, none of the cooling models considered are able to halt
+cooling catastrophe, suggesting that the galaxy motions alone are unlikely to
+solve the cooling flow problem.",0707.4330v1
+2007-08-30,Aggregate Dynamics in an Evolutionary Network Model,"We analyze a model of interacting agents (e.g. prebiotic chemical species)
+which are represended by nodes of a network, whereas their interactions are
+mapped onto directed links between these nodes. On a fast time scale, each
+agent follows an eigendynamics based on catalytic support from other nodes,
+whereas on a much slower time scale the network evolves through selection and
+mutation of its nodes-agent. In the first part of the paper, we explain the
+dynamics of the model by means of characteristic snapshots of the network
+evolution and confirm earlier findings on crashes an recoveries in the network
+structure. In the second part, we focus on the aggregate behavior of the
+network dynamics. We show that the disruptions in the network structure are
+smoothed out, so that the average evolution can be described by a growth regime
+followed by a saturation regime, without an initial random regime. For the
+saturation regime, we obtain a logarithmic scaling between the average
+connectivity per node $\mean{l}_{s}$ and a parameter $m$, describing the
+average incoming connectivity, which is independent of the system size $N$.",0708.4212v1
+2007-09-10,On the Dipole Swing and the Search for Frame Independence in the Dipole Model,"Small-x evolution in QCD is conveniently described by Mueller's dipole model
+which, however, does not include saturation effects in a way consistent with
+boost invariance. In this paper we first show that the recently studied zero
+and one dimensional toy models exhibiting saturation and explicit boost
+invariance can be interpreted in terms positive definite k-> k+1 dipole
+vertices. Such k-> k+1 vertices can in the full model be generated by combining
+the usual dipole splitting with k-1 simultaneous dipole swings. We show that,
+for a system consisting of N dipoles, one needs to combine the dipole splitting
+with at most N-1 simultaneous swings in order to generate all colour
+correlations induced by the multiple dipole interactions.",0709.1371v2
+2007-09-12,"""Slow Light"" and ""Slow Current""","It is shown that the effect of hole-burning under conditions of coherent
+population oscillations as well as the light pulse delay in a saturable
+absorber (a modification of the ""slow light"" effect) can be interpreted, in a
+comprehensive way, in terms of {\it intensity spectrum} of the light and {\it
+intensity-related susceptibility} of the non-linear medium. The physical
+content of these effects is illustrated by a simple electric circuit with a
+non-linear resistor which realizes a full analog of the saturable absorber. In
+this case the effect of hole-burning in the absorption spectrum of the medium
+is converted in to the effect of hole-burning in the frequency dependence of
+resistance of the non-linear resistor and the effect of ""slow light"" -- in to
+the effect of ""slow current"".",0709.1764v1
+2007-09-26,High-resolution saturation spectroscopy of singly-ionized iron with a pulsed uv laser,"We describe the design and realization of a scheme for uv laser spectroscopy
+of singly-ionized iron (Fe II) with very high resolution. A buffer-gas cooled
+laser ablation source is used to provide a plasma close to room temperature
+with a high density of Fe II. We combine this with a scheme for pulsed-laser
+saturation spectroscopy to yield sub-Doppler resolution. In a demonstration
+experiment, we have examined an Fe II transition near 260 nm, attaining a
+linewidth of about 250 MHz. The method is well-suited to measuring transition
+frequencies and hyperfine structure. It could also be used to measure small
+isotope shifts in isotope-enriched samples.",0709.4032v1
+2007-09-28,Dynamics of the triple contact line on a non-isothermal heater at partial wetting,"The dynamics of the triple gas-liquid-solid contact line is analysed for the
+case where the gas is the saturated vapour corresponding to the liquid, like in
+the vapour bubble in boiling. It is shown that even small superheating (with
+respect to the saturation temperature) causes evaporation of the adsorption
+liquid film and the true triple contact is established. It is shown that the
+hydrodynamic contact line singularity cannot be relaxed with the Navier slip
+condition under such circumstances. Augmented with the second derivative slip
+condition is proposed to be applied. For the partial wetting conditions, a
+non-stationary contact line problem where the contact line motion is caused by
+evaporation or condensation is treated in the lubrication approximation in the
+vicinity of the contact line. High heat fluxes in this region require the
+transient heat conduction inside the heater to be accounted for. Two 2D
+problems, those of drop retraction with no phase change and of drop evaporation
+are solved and analysed as illustrations of the proposed approach.",0709.4631v3
+2007-10-09,"Controlling suction by vapour equilibrium technique at different temperatures, application to the determination of the water retention properties of MX80 clay","Problems related to unsaturated soils are frequently encountered in
+geotechnical or environmental engineering works. In most cases, for the purpose
+of simplicity, the problems are studied by considering the suction effects on
+volume change or shear strength under isothermal conditions. Under isothermal
+condition, very often, a temperature independent water retention curve is
+considered in the analysis, which is obviously a simplification. When the
+temperature changes are too significant to be neglected, it is necessary to
+account for the thermal effects. In this paper, a method for controlling
+suction using the vapour equilibrium technique at different temperatures is
+presented. First, calibration of various saturated saline solutions was carried
+out from temperature of 20 degrees C to 60 degrees C. A mirror psychrometer was
+used for the measurement of relative humidity generated by saturated saline
+solutions at different temperatures. The results obtained are in good agreement
+with the data from the literature. This information was then used to determine
+the water retention properties of MX80 clay, which showed that the retention
+curve is shifting down with increasing of temperature.",0710.1850v1
+2007-10-15,Large nonlinear absorption and refraction coefficients of carbon nanotubes estimated from femtosecond Z-scan measurements,"Nonlinear transmission of 80 and 140 femtosecond pulsed light with $0.79 \mu
+m$ wavelength through single walled carbon nanotubes suspended in water
+containing sodium dodecyl sulphate is studied. Pulse-width independent
+saturation absorption and negative cubic nonlinearity are observed,
+respectively, in open and closed aperture Z-scan experiments. The theoretical
+expressions derived to analyze the z-dependent transmission in the saturable
+limit require two photon absorption coefficient $\beta_0\sim$ $1.4 cm/MW$ and a
+nonlinear index $\gamma \sim -5.5 \times10^{-11} cm^2/W$ to fit the data.",0710.2721v2
+2007-10-15,Current saturation and Coulomb interactions in organic single-crystal transistors,"Electronic transport through rubrene single-crystal field effect transistors
+(FETs) is investigated experimentally in the high carrier density regime (n ~
+0.1 carrier/molecule). In this regime, we find that the current does not
+increase linearly with the density of charge carriers, and tends to saturate.
+At the same time, the activation energy for transport unexpectedly increases
+with increasing n. We perform a theoretical analysis in terms of a well-defined
+microscopic model for interacting Frohlich polarons, that quantitatively
+accounts for our experimental observations. This work is particularly
+significant for our understanding of electronic transport through organic FETs.",0710.2845v2
+2007-10-29,Deep inelastic scattering off a N=4 SYM plasma at strong coupling,"By using the AdS/CFT correspondence we study the deep inelastic scattering of
+an R-current off a N=4 supersymmetric Yang-Mills (SYM) plasma at finite
+temperature and strong coupling. Within the supergravity approximation valid
+when the number of colors is large, we compute the structure functions by
+solving Maxwell equations in the space-time geometry of the AdS_5 black
+three-brane. We find a rather sharp transition between a low energy regime
+where the scattering is weak and quasi-elastic, and a high-energy regime where
+the current is completely absorbed. The critical energy for this transition
+determines the plasma saturation momentum in terms of its temperature T and the
+Bjorken x variable: Q_s=T/x. These results suggest a partonic picture for the
+plasma where all the partons have transverse momenta below the saturation
+momentum and occupation numbers of order one.",0710.5297v2
+2007-11-19,Wilson line correlator in the MV model: relating the glasma to deep inelastic scattering,"In the color glass condensate framework the saturation scale measured in deep
+inelastic scattering of high energy hadrons and nuclei can be determined from
+the correlator of Wilson lines in the hadron wavefunction. These same Wilson
+lines give the initial condition of the classical field computation of the
+initial gluon multiplicity and energy density in a heavy ion collision. In this
+paper the Wilson line correlator in both adjoint and fundamental
+representations is computed using exactly the same numerical procedure that has
+been used to calculate gluon production in a heavy ion collision. In particular
+the discretization of the longitudinal coordinate has a large numerical effect
+on the relation between the color charge density parameter g^2 mu and the
+saturation scale Qs. Our result for this relation is Qs = 0.6 g^2 mu, which
+results in the classical Yang-Mills value for the ""gluon liberation
+coefficient"" c = 1.1.",0711.3039v3
+2007-12-17,Impact parameter dependent colour glass condensate dipole model,"We show that the colour glass condensate dipole model of Iancu, Itakura and
+Munier, improved to include the impact parameter dependence, gives a good fit
+to the total gamma* p cross section measured at HERA if the anomalous dimension
+at the saturation scale, gamma_s, is treated as a free parameter. We find that
+the optimum value of gamma_s = 0.46 is close to the value determined from
+numerical solution of the Balitsky-Kovchegov equation. The impact parameter
+dependent saturation scale is generally less than 0.5 GeV^2 in the HERA
+kinematic regime for the most relevant impact parameters b ~ 2-3 GeV^{-1}. We
+compare predictions of the model to data on the longitudinal and heavy flavour
+structure functions, exclusive diffractive vector meson production and deeply
+virtual Compton scattering at HERA. The model is found to be deficient for
+observables sensitive to moderately small dipole sizes, where an alternative
+model with explicit DGLAP evolution performs better. The energy dependence of
+exclusive diffractive processes is shown to provide an important discriminator
+between different dipole model cross sections.",0712.2670v2
+2007-12-21,A nuclear matter description based on quark structure of the nucleon and pion exchange,"We investigate the possibility to describe nuclear matter in an approach
+constrained by the prominent features of quantum chromodynamics. We mapped the
+in-medium nucleon self-energies of a point coupling relativistic mean-field
+model on self-energies obtained in effective theories of QCD. More precisely,
+the contributions to the nucleon self-energy have been separated into the short
+range part, driven principally by the quark structure of the nucleon described
+in a quark-diquark picture, and the long range part, dictated by pion dynamics
+and determined using in-medium chiral perturbation theory. A saturation point,
+although unrealistic, is obtained without any free parameter. A realistic
+description of nuclear matter saturation properties has been obtained with the
+inclusion of a small phenomenological correction term to the short range part
+of the self-energy.",0712.3661v3
+2007-12-21,Front motion and localized states in an asymmetric bistable activator-inhibitor system with saturation,"We study the spatiotemporal properties of coherent states (peaks, holes, and
+fronts) in a bistable activator-inhibitor system that exhibits biochemical
+saturated autocatalysis, and in which fronts do not preserve spatial parity
+symmetry. Using the Gierer-Meinhardt prototype model, we find the conditions in
+which two distinct pinning regions are formed. The first pinning type is known
+in the context of variational systems while the second is structurally
+different due to the presence of a heteroclinic bifurcation between two uniform
+states. The bifurcation also separates the parameter regions of
+counterpropagating fronts, leading in turn to the growth or contraction of
+activator domains. These phenomena expand the range of pattern formation theory
+and its biomedical applications: activator domain retraction suggests potential
+therapeutic strategies for patterned pathologies, such as cardiovascular
+calcification.",0712.3790v2
+2008-01-01,Unitarity Constraints on Semi-hard Jet Production in Impact Parameter Space,"The perturbative QCD formula for minijet production consitutes an important
+ingredient in models describing the total cross section and multiparticle
+production in hadron-hadron scattering at high energies. Using arguments based
+on s-channel unitarity we set bounds on the minimum value of p_T for which the
+leading twist minijet formula can be used. For large impact parameters where
+correlations between partons appear to be small we find that the minimum value
+of p_T should be greater than 2.5 GeV for LHC energies and greater than 3.5 GeV
+for cosmic ray energies of about 50 TeV. We also argue that for collisions with
+values of impact parameters typical for heavy particle production the values of
+minimum p_T are likely to be considerably larger. We also analyze and quantify
+the potential role of saturation effects in the gluon density. We find that
+although saturation effects alone are not sufficient to restore unitarity, they
+are likely to play an important role at LHC energies.",0801.0303v1
+2008-01-03,Albite feldspar dissolution kinetics as a function of the Gibbs free energy at high pCO_2,"We are currently measuring the dissolution kinetics of albite feldspar at 100
+deg C in the presence of high levels of dissolved CO_2 (pCO_2 = 9 MPa) as a
+function of the saturation state of the feldspar (Gibbs free energy of
+reaction, \Delta G). The experiments are conducted using a flow through
+reactor, thereby allowing the dissolution reactions to occur at a fixed pH and
+at constant, but variable saturation states. Preliminary results indicate that
+at far-from-equilibrium conditions, the dissolution kinetics of albite are
+defined by a rate plateau, with R \approx 5.0 x 10^{-10} mol m^{-2} s^{-1} at
+-70 < \Delta G < -40 kJ mol^{-1}. At \Delta G > -40 kJ mol^{-1}, the rates
+decrease sharply, revealing a strong inverse relation between the dissolution
+rate and free energy. Based on the experiments carried out to date, the
+dissolution rate-free energy data correspond to a highly non-linear and
+sigmoidal relation, in accord with recent studies.",0801.0548v1
+2008-01-04,Classical Dynamics of the Time-Dependent Elliptical Billiard,"In this work we study the nonlinear dynamics of the static and the driven
+ellipse. In the static case, we find numerically an asymptotical algebraic
+decay for the escape of an ensemble of non-interacting particles through a
+small hole due to the integrable structure of the phase space of the system.
+Furthermore, for a certain hole position a saturation value in the decay that
+can be tuned arbitrarily by varying the eccentricity of the ellipse is observed
+and explained. When applying harmonic boundary oscillations this saturation
+value caused by librator type orbits is gradually destroyed via two fundamental
+processes which are discussed in detail. As a result, an amplitude dependent
+emission rate is obtained in the long time behavior of the decay, suggesting
+that the driven elliptical billiard can be used as a controllable source of
+particles.",0801.0686v1
+2008-01-22,Multi-$\bar{K}$ nuclei and kaon condensation,"We extend previous relativistic mean-field (RMF) calculations of multi-$\bar
+K$ nuclei, using vector boson fields with SU(3) PPV coupling constants and
+scalar boson fields constrained phenomenologically. For a given core nucleus,
+the resulting $\bar K$ separation energy $B_{\bar K}$, as well as the
+associated nuclear and $\bar K$-meson densities, saturate with the number
+$\kappa$ of $\bar K$ mesons for $\kappa > \kappa_{\rm sat} \sim 10$. Saturation
+appears robust against a wide range of variations, including the RMF nuclear
+model used and the type of boson fields mediating the strong interactions.
+Because $B_{\bar K}$ generally does not exceed 200 MeV, it is argued that
+multi-$\bar K$ nuclei do not compete with multihyperonic nuclei in providing
+the ground state of strange hadronic configurations and that kaon condensation
+is unlikely to occur in strong-interaction self-bound strange hadronic matter.
+Last, we explore possibly self-bound strange systems made of neutrons and
+${\bar K}^0$ mesons, or protons and $K^-$ mesons, and study their properties.",0801.3335v2
+2008-02-12,Nonlinear Saturation of g-modes in Proto-Neutron Stars: Quieting the Acoustic Engine,"According to Burrows et al.'s acoustic mechanism for core-collapse supernova
+explosions, the primary, l=1, g-mode in the core of the proto-neutron star is
+excited to an energy of ~ 10^{50} ergs and damps by the emission of sound
+waves. Here we calculate the damping of the primary mode by the parametric
+instability, i.e., by nonlinear, 3-mode coupling between the low-order primary
+mode and pairs of high-order g-modes. We show that the primary mode is strongly
+coupled to highly resonant, neutrino damped pairs with n>10; such short
+wavelength interactions cannot be resolved in the simulations. We find that the
+parametric instability saturates the primary mode energy at ~10^{48} ergs, well
+below the energy needed to drive an explosion. We therefore conclude that
+acoustic power is unlikely to be energetically significant in core-collapse
+supernova explosions.",0802.1522v3
+2008-02-13,Effects of spatial dispersion in near-field radiative heat transfer between two parallel metallic surfaces,"We study the heat transfer between two parallel metallic semi-infinite media
+with a gap in the nanometer-scale range. We show that the near-field radiative
+heat flux saturates at distances smaller than the metal skin depth when using a
+local dielectric constant and investigate the origin of this effect. The effect
+of non-local corrections is analysed using the Lindhard-Mermin and
+Boltzmann-Mermin models. We find that local and non-local models yield the same
+heat fluxes for gaps larger than 2 nm. Finally, we explain the saturation
+observed in a recent experiment as a manifestation of the skin depth and show
+that heat is mainly dissipated by eddy currents in metallic bodies.",0802.1899v1
+2008-02-20,Gluon multiplicity in coherent diffraction of onium on a heavy nucleus,"We derive the cross section for the diffractive gluon production in high
+energy onium-nucleus collisions that includes the low-x evolution effects in
+the rapidity interval between the onium and the produced gluon and in the
+rapidity interval between the gluon and the target nucleus. We analyze our
+result in two limiting cases: when the onium size is much smaller than the
+saturation scale and when its size is much larger than the saturation scale. In
+the later case the gluon multiplicity is very small in the quasi-classical case
+and increases when the low-x evolution effects in onium become significant. We
+discuss the implications of our result for the RHIC, LHC and EIC phenomenology.",0802.2954v2
+2008-02-25,Data Traffic Dynamics and Saturation on a Single Link,"The dynamics of User Datagram Protocol (UDP) traffic over Ethernet between
+two computers are analyzed using nonlinear dynamics which shows that there are
+two clear regimes in the data flow: free flow and saturated. The two most
+important variables affecting this are the packet size and packet flow rate.
+However, this transition is due to a transcritical bifurcation rather than
+phase transition in models such as in vehicle traffic or theorized large-scale
+computer network congestion. It is hoped this model will help lay the
+groundwork for further research on the dynamics of networks, especially
+computer networks.",0802.3554v3
+2008-03-27,Optimal factorial designs for cDNA microarray experiments,"We consider cDNA microarray experiments when the cell populations have a
+factorial structure, and investigate the problem of their optimal designing
+under a baseline parametrization where the objects of interest differ from
+those under the more common orthogonal parametrization. First, analytical
+results are given for the $2\times 2$ factorial. Since practical applications
+often involve a more complex factorial structure, we next explore general
+factorials and obtain a collection of optimal designs in the saturated, that
+is, most economic, case. This, in turn, is seen to yield an approach for
+finding optimal or efficient designs in the practically more important nearly
+saturated cases. Thereafter, the findings are extended to the more intricate
+situation where the underlying model incorporates dye-coloring effects, and the
+role of dye-swapping is critically examined.",0803.3911v1
+2008-03-31,Stabilization of dipole solitons in nonlocal nonlinear media,"We address the stabilization of dipole solitons in nonlocal nonlinear
+materials by two different approaches. First, we study the properties of such
+solitons in thermal nonlinear media, where the refractive index landscapes
+induced by laser beams strongly depend on the boundary conditions and on the
+sample geometry. We show how the sample geometry impacts the stability of
+higher-order solitons in thermal nonlinear media and reveal that dipole
+solitons can be made dynami-cally stable in rectangular geometries in contrast
+to their counterparts in thermal samples with square cross-section. Second, we
+discuss the impact of the saturation of the nonlocal nonlinear response on the
+properties of multipole solitons. We find that the saturable response also
+stabi-lizes dipole solitons even in symmetric geometries, provided that the
+input power exceeds a criti-cal value.",0803.4398v1
+2008-04-01,Novel Sets of Coupling Expansion Parameters for low-energy pQCD,"In quantum theory, physical amplitudes are usually presented in the form of
+Feynman perturbation series in powers of coupling constant $\al .$ However, it
+is known that these amplitudes are not regular functions at $\alpha=0 .$
+  For QCD, we propose new sets of expansion parameters ${\bf w}_k(\as)$ that
+reflect singularity at $\as=0 $ and should be used instead of powers $\as^k.$
+Their explicit form is motivated by the so called Analytic Perturbation Theory.
+These parameters reveal saturation in a strong coupling case at the level
+$\as^{eff}(\as\gg1)={\bf w}_1(\as\gg 1) \sim 0.5 .$ They can be used for
+quanitative analysis of divers low-energy amplitudes.
+  We argue that this new picture with non-power sets of perturbation expansion
+parameters, as well as the saturation feature, is of a rather general nature.",0804.0083v1
+2008-04-01,Soliton structures in a molecular chain model with saturation,"In the present work, we study, by means of a one-dimensional lattice model,
+the collective excitations corresponding to intra molecular ones of a chain
+like proteins. It is shown that such excitations are described by the Nonlinear
+Schrodinger equation with saturation. The solutions obtained here are the bell
+solitons, bubbles, kinks and crowdons. Since they belong to different sectors
+on the parametric space, the bubble condensation could give place to some
+important changes of face in this kind of nonlinear system. Additionally, it is
+shown that the limiting velocity of the solitons is the velocity of sound waves
+corresponding to longitudinal vibrations of molecules.",0804.0222v2
+2008-04-01,Decoherence of Bell states by local interactions with a dynamic spin environment,"We study the evolution of a system of two qubits, each of which interacts
+locally with a spin chain with nontrivial internal Hamiltonian. We present an
+exact solution to this problem and analyze the dependence of decoherence on the
+distance between the interaction sites. In the strong coupling regime we find
+that decoherence increases with increasing distance. In the weak coupling
+regime the dependence of decoherence with distance is not generic (i.e., it
+varies according to the initial state). Decoherence becomes independent of
+distance when the latter is over a saturation length $l$. Numerical results for
+the Ising chain suggest that the saturation scale is related to the correlation
+length $\xi$. For strong coupling we display evidence of the existence of
+non--Markovian effects (such as environment--induced interactions between the
+qubits). As a consequence the system can undergo a quasiperiodic sequence of
+``sudden deaths and revivals'' of entanglement, with a time scale related to
+the distance between qubits.",0804.0241v2
+2008-05-31,The Emerging QCD Frontier: The Electron Ion Collider,"The self-interactions of gluons determine all the unique features of QCD and
+lead to a dominant abundance of gluons inside matter already at moderate $x$.
+Despite their dominant role, the properties of gluons remain largely
+unexplored. Tantalizing hints of saturated gluon densities have been found in
+$e$+p collisions at HERA, and in d+Au and Au+Au collisions at RHIC. Saturation
+physics will have a profound influence on heavy-ion collisions at the LHC. But
+unveiling the collective behavior of dense assemblies of gluons under
+conditions where their self-interactions dominate will require an Electron-Ion
+Collider (EIC): a new facility with capabilities well beyond those In this
+paper I outline the compelling physics case for $e$+A collisions at an EIC and
+discuss briefly the status of machine design concepts. of any existing
+accelerator.",0806.0048v1
+2008-06-04,Particle Multiplicities in Nuclear Collisions at the LHC from Saturation Physics,"The inclusion of running coupling effects in the BK-JIMWLK evolution
+equations considerably reduces the energy dependence of the saturation scale
+with respect to previous estimates based on fits to HERA data. We discuss how
+such slowdown affects the expectations for particle multiplicities in Pb-Pb
+collisions at LHC energies. Our prediction is based on the use of
+k_t-factorization and on the use of unintegrated gluon distributions taken from
+the numerical solutions of the BK equation with running coupling. We obtain a
+central value dN/d\eta(sqrt{s}=5.5 TeV)(\eta=0)~1390.",0806.0672v1
+2008-06-04,Relativistic mean-field theory applied to the study of neutron star properties,"Nuclear physics can be applied in various ways to the study of neutron stars.
+This thesis reports on one such application, where the relativistic mean-field
+approximation has been employed to calculate the equations of state of matter
+in the neutron star interior. In particular the equations of state of nuclear
+and neutron star matter of the NL3, PK1 and FSUGold parameter sets were
+derived. A survey of available literature on neutron stars is presented and we
+use the derived equations of state to reproduce the properties of saturated
+nuclear matter as well as the mass-radius relationship of a static, spherical
+symmetric neutron star. Results are compared to published values of the
+properties of saturated nuclear matter and to available observational data of
+the mass-radius relationship of neutron stars.",0806.0747v2
+2008-06-30,On Internal Consistency of Holographic Dark Energy Models,"Holographic dark energy (HDE) models, underlain by an effective quantum field
+theory (QFT) with a manifest UV/IR connection, have become a convincing
+candidate for the dark energy in the universe. On the other hand, the maximum
+number of quantum states a conventional QFT in the box of size $L$ is capable
+to describe, refer to those boxes which are on the brink of experiencing a
+sudden collapse to a black hole. Another restriction on the underlying QFT is
+that the UV cutoff, which cannot be chosen independently of the IR cutoff and
+therefore becomes a function of time in a cosmological setting, should stay the
+largest energy scale even in the standard cosmological epochs preceding a dark
+energy dominated one. We show that, irrespective of whether one deals with the
+saturated form of HDE or takes a certain degree of non-saturation in the past,
+the above restrictions cannot be met in a radiation-dominated universe, an
+epoch in the history of the universe which is expected to be perfectly
+describable within conventional QFT.",0806.4825v2
+2008-07-01,Deconfinement phase transition in hybrid neutron stars from the Brueckner theory with three-body forces and a quark model with chiral mass scaling,"We study the properties of strange quark matter in equilibrium with normal
+nuclear matter. Instead of using the conventional bag model in quark sector, we
+achieve the confinement by a density-dependent quark mass derived from
+in-medium chiral condensates. In nuclear matter, we adopt the equation of state
+from the Brueckner-Bethe-Goldstone approach with three-body forces. It is found
+that the mixed phase can occur, for a reasonable confinement parameter, near
+the normal nuclear saturation density, and goes over into pure quark matter at
+about 5 times the saturation. The onset of mixed and quark phases is compatible
+with the observed class of low-mass neutron stars, but it hinders the
+occurrence of kaon condensation.",0807.0200v1
+2008-07-02,A note on the connection between the universal relaxation bound and the covariant entropy bound,"A recently proposed universal lower-bound to the characteristic relaxation
+times of perturbed thermodynamic systems, derived from quantum information
+theory and (classical) thermodynamics and known to be saturated for (certain)
+black holes, is investigated in the light of the gravity/thermodynamics
+connection. A statistical-mechanical property, unrelated to gravity, essential
+for the validity of the generalized covariant entropy bound, namely the
+existence of a lower-limiting value l* for the size of thermodynamic systems,
+is found to provide a way to understand the universal relaxation bound, thus
+regardless of the kind of foundations (i.e. whether conventional or
+information-based) of the statistical-mechanical description. As a by-product
+an example of a conventional system (i.e. not a black hole) seemingly
+saturating the universal relaxation bound is provided.",0807.0300v2
+2008-07-09,Ultrafast switching time and third order nonlinear coefficients of microwave treated single walled carbon nanotube suspensions,"Microwave treated water soluble and amide functionalized single walled carbon
+nanotubes have been investigated using femtosecond degenerate pump-probe and
+nonlinear transmission experiments. The time resolved differential transmission
+using 75 femtosecond pulse with the central wavelength of 790 nm shows a
+bi-exponential ultrafast photo-bleaching with time constants of of 160 fs (130
+fs) and 920 fs (300 fs) for water soluble (amide functionalized) nanotubes.
+Open and closed aperture z-scans show saturation absorption and positive
+(negative) nonlinear refraction for water soluble (amide functionalized)
+nanotubes. Two photon absorption coefficient,beata ~250 cm/GW (650 cm/GW) and
+nonlinear index, gamma ~ 15 cm^2/pW (-30 cm^2/pW) are obtained from the
+theoretical fit in the saturation limit to the data for two types of nanotubes.",0807.1441v1
+2008-07-21,Characterisation of a silicon photomultiplier device for applications in liquid argon based neutrino physics and dark matter searches,"The performance of a silicon photomultiplier has been assessed at low
+temperature in order to evaluate its suitability as a scintillation readout
+device in liquid argon particle physics detectors. The gain, measured as 2.1E6
+for a constant over-voltage of 4V was measured between 25degC and -196degC and
+found to be invariant with temperature, the corresponding single photoelectron
+dark count rate reducing from 1MHz to 40Hz respectively. Following multiple
+thermal cycles no deterioration in the device performance was observed. The
+photon detection efficiency (PDE) was assessed as a function of photon
+wavelength and temperature. For an over-voltage of 4V, the PDE, found again to
+be invariant with temperature, was measured as 25% for 460nm photons and 11%
+for 680nm photons. Device saturation due to high photon flux rate, observed
+both at room temperature and -196degC, was again found to be independent of
+temperature. Although the output signal remained proportional to the input
+signal so long as the saturation limit was not exceeded, the photoelectron
+pulse resolution and decay time increased slightly at -196degC.",0807.3220v2
+2008-07-24,Ideals with an assigned initial ideal,"The stratum St(J,<) (the homogeneous stratum Sth(J,<) respectively) of a
+monomial ideal J in a polynomial ring R is the family of all (homogeneous)
+ideals of R whose initial ideal with respect to the term order < is J. St(J,<)
+and Sth(J,<) have a natural structure of affine schemes. Moreover they are
+homogeneous w.r.t. a non-standard grading called level. This property allows us
+to draw consequences that are interesting from both a theoretical and a
+computational point of view. For instance a smooth stratum is always isomorphic
+to an affine space (Corollary 3.6). As applications, in Sec. 5 we prove that
+strata and homogeneous strata w.r.t. any term ordering < of every saturated
+Lex-segment ideal J are smooth. For Sth(J,Lex) we also give a formula for the
+dimension. In the same way in Sec. 6 we consider any ideal R in k[x0,..., xn]
+generated by a saturated RevLex-segment ideal in k[x,y,z]. We also prove that
+Sth(R,RevLex) is smooth and give a formula for its dimension.",0807.3877v4
+2008-08-02,Hot accretion with outflow and thermal conduction,"We present self-similar solutions for advection -dominated accretion flows
+with thermal conduction in the presence of outflows. Possible effects of
+outflows on the accretion flow are parametrized and a saturated form of thermal
+conduction, as is appropriate for the weakly-collisional regime of interest, is
+included in our model. While the cooling effect of outflows is noticeable,
+thermal conduction provides an extra heating source. In comparison to accretion
+flows without winds, we show that the disc rotates faster and becomes cooler
+because of the angular momentum and energy flux which are taking away by the
+winds. But thermal conduction opposes the effects of winds and not only
+decreases the rotational velocity, but increases the temperature. However,
+reduction of the surface density and the enhanced accretion velocity are
+amplified by both of the winds and the thermal conduction. We find that for
+stronger outflows, a higher level of saturated thermal conduction is needed to
+significantly modify the physical profiles of the accretion flow.",0808.0245v1
+2008-08-07,Gluon density and $F_{2}$ functions from BK equation with local impact parameter dependence in DIS on nuclei,"The DIS process on nuclei is considered in the framework of LO BK equation
+with local impact parameter dependence. Solving BK equation parameters for
+initial conditions of GBW type found in \cite{Serg1} were used. Integrated
+gluon density function and $F_2$ nucleus structure function for different
+nuclei are calculated. Obtained results are compared with the different
+parameterizations of integrated gluon density function from
+\cite{Flor,Eskola1,Eskola2,Tywon}. The anomalous dimensions and saturation
+scales for different nuclei are calculated at different energies. Fitting
+obtained results, expressions for the form of saturation scale are obtained for
+the proton and different nuclei as functions of impact parameter and energy.",0808.1040v3
+2008-08-08,Spontaneous recoil effects of optical pumping on trapped atoms,"The recoil effects of spontaneous photon emissions during optical pumping of
+a trapped three-level atom are exactly calculated. Without resort to the
+Lamb-Dicke approximation, and considering arbitrary detuning and saturation of
+the pump laser, the density of recoil shifts in phase space is derived. It is
+shown that this density is not of Gaussian shape, and that it becomes isotropic
+in phase space only for a branching ratio corresponding to fluorescence
+scattering but unfavorable for optical pumping. The dependence of its
+anisotropy on the laser saturation is discussed in the resonant case, and the
+mapping of moments of the atom's center-of-mass motion due to the pumping is
+presented. Moreover, it is shown how optimum parameters for protecting the
+center-of-mass quantum state from pump-induced disturbance depend on the
+specific property to be protected.",0808.1272v1
+2008-08-21,In medium T-matrix for nuclear matter with three-body forces - binding energy and single particle properties,"We present spectral calculations of nuclear matter properties including
+three-body forces. Within the in-medium T-matrix approach, implemented with the
+CD-Bonn and Nijmegen potentials plus the three-nucleon Urbana interaction, we
+compute the energy per particle in symmetric and neutron matter. The three-body
+forces are included via an effective density dependent two-body force in the
+in-medium T-matrix equations. After fine tuning the parameters of the
+three-body force to reproduce the phenomenological saturation point in
+symmetric nuclear matter, we calculate the incompressibility and the energy per
+particle in neutron matter. We find a soft equation of state in symmetric
+nuclear matter but a relatively large value of the symmetry energy. We study
+the the influence of the three-body forces on the single-particle properties.
+For symmetric matter the spectral function is broadened at all momenta and all
+densities, while an opposite effect is found for the case of neutrons only.
+Noticeable modification of the spectral functions are realized only for
+densities above the saturation density. The modifications of the self-energy
+and the effective mass are not very large and appear to be strongly suppressed
+above the Fermi momentum.",0808.2929v1
+2008-09-08,Effect of Disorder on the Quantum Coherence in Mesoscopic Wires,"We present phase coherence time measurements in quasi-one-dimensional
+mesoscopic wires made from high mobility two-dimensional electron gas. By
+implanting gallium ions into a GaAs/AlGaAs heterojunction we are able to vary
+the diffusion coefficient over 2 orders of magnitude. We show that in the
+diffusive limit, the decoherence time follows a power law as a function of
+diffusion coefficient as expected by theory. When the disorder is low enough so
+that the samples are semi-ballistic, we observe a new and unexpected regime in
+which the phase coherence time is independent of disorder. In addition, for all
+samples the temperature dependence of the phase coherence time follows a power
+law down to the lowest temperatures without any sign of saturation and strongly
+suggests that the frequently observed low temperature saturation is not
+intrinsic.",0809.1381v3
+2008-09-10,Entanglement of Solitons in the Frenkel-Kontorova Model,"We investigate entanglement of solitons in the continuum-limit of the
+nonlinear Frenkel-Kontorova chain. We find that the entanglement of solitons
+manifests particle-like behavior as they are characterized by localization of
+entanglement. The von-Neumann entropy of solitons mixes critical with
+noncritical behaviors. Inside the core of the soliton the logarithmic increase
+of the entropy is faster than the universal increase of a critical field,
+whereas outside the core the entropy decreases and saturates the constant value
+of the corresponding massive noncritical field. In addition, two solitons
+manifest long-range entanglement that decreases with the separation of the
+solitons more slowly than the universal decrease of the critical field.
+Interestingly, in the noncritical regime of the Frenkel-Kontorova model,
+entanglement can even increase with the separation of the solitons. We show
+that most of the entanglement of the so-called internal modes of the solitons
+is saturated by local degrees of freedom inside the core, and therefore we
+suggest using the internal modes as carriers of quantum information.",0809.1857v1
+2008-09-17,J/Psi production in heavy ion collisions and gluon saturation,"We calculate the inclusive J/Psi production in heavy ion collisions including
+the effects of gluon saturation in the wave functions of the colliding nuclei.
+We argue that the dominant production mechanism in proton--nucleus and
+nucleus--nucleus collisions for heavy nuclei is different from the one in
+hadron-hadron interactions. We find that the rapidity distribution of primary
+J/Psi production is more peaked around midrapidity than the analogous
+distribution in elementary pp collisions. We discuss the consequences of this
+fact on the experimentally observed J/Psi suppression in Au-Au collisions at
+RHIC energies.",0809.2933v2
+2008-09-26,Covariant and self consistent vertex corrections for pions and isobars in nuclear matter,"We evaluate the pion and isobar propagators in cold nuclear matter self
+consistently applying a covariant form of the isobar-hole model. Migdal's
+vertex correction effects are considered systematically in the absence of
+phenomenological soft form factors. Saturated nuclear matter is modeled by
+scalar and vector mean fields for the nucleon. It is shown that the short-range
+dressing of the pi N Delta vertex has a significant effect on the pion and
+isobar properties. Using realistic parameters sets we predict a downward shift
+of about 50 MeV for the Delta resonance at nuclear saturation density. The
+pionic soft modes are much less pronounced than in previous studies.",0809.4604v1
+2008-09-29,DNS of the kappa-mechanism,"We present a purely-radiative hydrodynamic model of the kappa-mechanism that
+sustains radial oscillations in Cepheid variables. We determine the physical
+conditions favourable for the kappa-mechanism to occur by the means of a
+configurable hollow in the radiative conductivity profile. By starting from
+these most favourable conditions, we complete nonlinear direct numerical
+simulations (DNS) and compare them with the results given by a linear-stability
+analysis of radial modes. We find that well-defined instability strips are
+generated by changing the location and shape of the conductivity hollow. For a
+given position in the layer, the hollow amplitude and width stand out as the
+key parameters governing the appearance of unstable modes driven by the
+kappa-mechanism. The DNS confirm both the growth rates and structures of the
+linearly-unstable modes. The nonlinear saturation that arises is produced by
+intricate couplings between the excited fundamental mode and higher damped
+overtones. These couplings are measured by projecting the DNS fields onto an
+acoustic subspace built from regular and adjoint eigenvectors and a 2:1
+resonance is found to be responsible for the saturation of the kappa-mechanism
+instability.",0809.4949v1
+2008-10-10,The effect of undrained heating on a fluid-saturated hardened cement paste,"The effect of undrained heating on volume change and induced pore pressure
+increase is an important point to properly understand the behaviour and
+evaluate the integrity of an oil well cement sheath submitted to rapid
+temperature changes. This thermal pressurization of the pore fluid is due to
+the discrepancy between the thermal expansion coefficients of the pore fluid
+and of the solid matrix. The equations governing the undrained
+thermo-hydro-mechanical response of a porous material are presented and the
+effect of undrained heating is studied experimentally for a saturated hardened
+cement paste. The measured value of the thermal pressurization coefficient is
+equal to 0.6MPa/&deg;C. The drained and undrained thermal expansion
+coefficients of the hardened cement paste are also measured in the heating
+tests. The anomalous thermal behaviour of cement pore fluid is back analysed
+from the results of the undrained heating test.",0810.1810v2
+2008-10-16,Oscillator topologies on a paratopological group and related number invariants,"We introduce and study oscillator topologies on paratopological groups and
+define certain related number invariants. As an application we prove that a
+Hausdorff paratopological group $G$ admits a weaker Hausdorff group topology
+provided $G$ is 3-oscillating. A paratopological group $G$ is 3-oscillating
+(resp. 2-oscillating) provided for any neighborhood $U$ of the unity $e$ of $G$
+there is a neighborhood $V\subset G$ of $e$ such that $V^{-1}VV^{-1}\subset
+UU^{-1}U$ (resp. $V^{-1}V\subset UU^{-1}$). The class of 2-oscillating
+paratopological groups includes all collapsing, all nilpotent paratopological
+groups, all paratopological groups satisfying a positive law, all
+paratopological SIN-group and all saturated paratopological groups (the latter
+means that for any nonempty open set $U\subset G$ the set $U^{-1}$ has nonempty
+interior). We prove that each totally bounded paratopological group $G$ is
+countably cellular; moreover, every cardinal of uncountable cofinality is a
+precaliber of $G$. Also we give an example of a saturated paratopological group
+which is not isomorphic to its mirror paratopological group as well as an
+example of a 2-oscillating paratopological group whose mirror paratopological
+group is not 2-oscillating.",0810.3028v2
+2008-10-17,Recent developments in the techniques of controlling and measuring suction in unsaturated soils,"The difficulty of measuring and controlling suction in unsaturated soils is
+one of the reasons why the development of the mechanics of unsaturated soils
+has not been as advanced as that of saturated soils. However, significant
+developments have been carried out in the last decade in this regard. In this
+paper, a re-view of some developments carried out in the techniques of
+controlling suction by using the axis translation, the osmotic method and the
+vapour control technique is presented. The paper also deals with some recent
+de-velopments in the direct measurement of suction by using high capacity
+tensiometers and in the measurement of high suction by using high range
+psychrometers. The recent progresses made in these techniques have been
+significant and will certainly help further experimental investigation of the
+hydromechanical behaviour of un-saturated soils.",0810.3221v1
+2008-10-23,Quantum Limits and Robustness of Nonlinear Intracavity Absorption Spectroscopy,"We investigate the limits of intracavity absorption spectroscopy with
+nonlinear media. Using a common theoretical framework, we compare the detection
+of a trace gas within an undriven cavity with gain near and above threshold, a
+driven cavity with gain kept just below threshold, and a cavity driven close to
+the saturation point of a saturable absorber. These phase-transition-based
+metrology methods are typically quantum-limited by spontaneous emission, and we
+compare them to the empty cavity shotnoise-limited case. Although the
+fundamental limits achievable with nonlinear media do not surpass the empty
+cavity limits, we show that nonlinear methods are more robust against certain
+technical noise models. This recognition may have applications in spectrometer
+design for devices operating in non-ideal field environments.",0810.4209v1
+2008-10-31,Adsorption properties and third sound propagation in superfluid $^4$He films on carbon nanotubes,"We consider the adsorption properties of superfluid $^4$He films on carbon
+nanotubes. One major factor in the adsorption is the surface tension force
+arising from the very small diameter of the nanotubes. Calculations show that
+surface tension keeps the film thickness on the tubes very thin even when the
+helium vapor is increased to the saturated pressure. The weakened Van der Waals
+force due to the cylindrical geometry also contributes to this. Both of these
+effects act to lower the predicted velocity of third sound propagation along
+the tubes. It does not appear that superfluidity will be possible on
+single-walled nanotubes of diameter about one nm, since the film thickness is
+less than 3 atomic layers even at saturation. Superfluidity is possible on
+larger-diameter nanotube bundles and multi-walled nanotubes, however. We have
+observed third sound signals on nanotube bundles of average diameter 5 nm which
+are sprayed onto a Plexiglass surface, forming a network of tubes.",0810.5627v1
+2008-11-11,Baryon Stopping as a new Probe of Geometric Scaling,"We suggest to use net-baryon rapidity distributions in central relativistic
+heavy-ion collisions at SPS, RHIC and LHC energies in order to probe saturation
+physics. Within the color glass condensate framework based on small-coupling
+QCD, net-baryon rapidity distributions are shown to exhibit geometric scaling.
+In a comparison with RHIC data in Au + Au collisions at sqrt(s_NN) = 62.4 GeV
+and 200 GeV the gradual approach to the gluon saturation regime is
+investigated. Predictions for net-baryon rapidity spectra and the mean rapidity
+loss in central Pb + Pb collisions at LHC energies of sqrt (s_NN) = 5.5 TeV are
+made.",0811.1721v3
+2008-11-25,Production and evolution path of dileptons at HADES energies,"Dilepton production in intermediate energy nucleus-nucleus collisions as well
+as in elementary proton-proton reactions is analysed within the UrQMD transport
+model. For C+C collisions at 1 AGeV and 2 AGeV the resulting invariant mass
+spectra are compared to recent HADES data. We find that the experimental
+spectrum for C+C at 2 AGeV is slightly overestimated by the theoretical
+calculations in the region around the vector meson peak, but fairly described
+in the low mass region, where the data is satisfactorily saturated by the
+Dalitz decay of the $\eta$ meson and the $\Delta$ resonance. At 1 AGeV an
+underestimation of the experimental data is found, pointing that at lower
+energies the low mass region is not fully saturated by standardly parametrized
+$\Delta$ Dalitz decays alone. Furthermore, predictions for dilepton spectra for
+$pp$ reactions at 1.25 GeV, 2.2 GeV and 3.5 GeV and Ar+KCl reactions at 1.75
+AGeV are presented. The study is complemented by a detailed investigation of
+the role of absorption of the parent particles on the corresponding dilepton
+yields in the regime which has so far been probed by HADES.",0811.4073v2
+2008-12-02,Saturation effects in experiments on the thermal Casimir effect,"We address three different problematic Casimir experiments in this work. The
+first is the classical Casimir force measured between two metal half spaces;
+here in the form of the Casimir pressure measurement between a gold sphere and
+a gold plate as performed by Decca et al. [Phys. Rev. D 75, 077101 (2007)];
+theory predicts a large negative thermal correction, absent in the high
+precision experiment. The second experiment is the measurement of the Casimir
+force between a metal plate and a laser irradiated semiconductor membrane as
+performed by Chen et al. [Phys. Rev. B 76, 035338 (2007)]; the change in force
+with laser intensity is larger than predicted by theory. The third experiment
+is the measurement of the Casimir force between an atom and a wall in the form
+of the measurement by Obrecht et al. [Phys. Rev. Lett. 98 063201 (2007)] of the
+change in oscillation frequency of a Rb Bose-Einstein condensate trapped to a
+fused silica wall; the change is smaller than predicted by theory. We show that
+saturation effects can explain the discrepancies between theory and experiment
+observed in all these cases.",0812.0509v1
+2008-12-05,Embedding solenoids in foliations,"In this paper we find smooth embeddings of solenoids in smooth foliations. We
+show that if a smooth foliation F of a manifold M contains a compact leaf L
+with H^1(L;R)= 0 and if the foliation is a product foliation in some saturated
+open neighbourhood U of L, then there exists a foliation F' on M which is
+C^1-close to F, and F' has an uncountable set of solenoidal minimal sets
+contained in U that are pair wise non-homeomorphic. If H^1(L;R) is not 0, then
+it is known that any sufficiently small perturbation of F contains a saturated
+product neighbourhood. Thus, our result can be thought of as an instability
+result complementing the stability results of Reeb, Thurston and Langevin and
+Rosenberg.",0812.1085v2
+2008-12-18,Bulk-mediated surface diffusion on a cylinder: propagators and crossovers,"We consider the effective surface motion of a particle that freely diffuses
+in the bulk and intermittently binds to that surface. From an exact approach we
+derive various regimes of the effective surface motion characterized by
+physical rates for binding/unbinding and the bulk diffusivity. We obtain a
+transient regime of superdiffusion and, in particular, a saturation regime
+characteristic for the cylindrical geometry. This saturation, however, in a
+finite system is not terminal but eventually turns over to normal surface
+diffusion. The first passage behavior of particles to the cylinder surface is
+derived. Consequences for actual systems are discussed.",0812.3627v1
+2008-12-19,Coronal activity from the ASAS eclipsing binaries,"We combine the catalogue of eclipsing binaries from the All Sky Automated
+Survey (ASAS) with the ROSAT All Sky Survey (RASS). The combination results in
+836 eclipsing binaries that display coronal activity and is the largest sample
+of active binary stars assembled to date. By using the (V-I) colors of the ASAS
+eclipsing binary catalogue, we are able to determine the distances and thus
+bolometric luminosities for the majority of eclipsing binaries that display
+significant stellar activity. A typical value for the ratio of soft X-ray to
+bolometric luminosity is L_X/L_bol ~ a few x 10^-4, similar to the ratio of
+soft X-ray to bolometric flux F_X/F_bol in the most active regions of the Sun.
+Unlike rapidly rotating isolated late-type dwarfs -- stars with significant
+outer convection zones -- a tight correlation between Rossby number and
+activity of eclipsing binaries is absent. We find evidence for the saturation
+effect and marginal evidence for the so-called ""super-saturation"" phenomena.
+Our work shows that wide-field stellar variability searches can produce a high
+yield of binary stars with strong coronal activity.
+  The combined ASAS and RASS catalogue, as well as the results of this work are
+available for download in a form of a file.",0812.3909v1
+2009-01-16,On the Capacity of the Discrete-Time Channel with Uniform Output Quantization,"This paper provides new insight into the classical problem of determining
+both the capacity of the discrete-time channel with uniform output quantization
+and the capacity achieving input distribution. It builds on earlier work by
+Gallager and Witsenhausen to provide a detailed analysis of two particular
+quantization schemes. The first is saturation quantization where overflows are
+mapped to the nearest quantization bin, and the second is wrapping quantization
+where overflows are mapped to the nearest quantization bin after reduction by
+some modulus. Both the capacity of wrapping quantization and the capacity
+achieving input distribution are determined. When the additive noise is
+gaussian and relatively small, the capacity of saturation quantization is shown
+to be bounded below by that of wrapping quantization. In the limit of
+arbitrarily many uniform quantization levels, it is shown that the difference
+between the upper and lower bounds on capacity given by Ihara is only 0.26
+bits.",0901.2545v1
+2009-02-04,Prime and almost prime integral points on principal homogeneous spaces,"We develop the affine sieve in the context of orbits of congruence subgroups
+of semi-simple groups acting linearly on affine space. In particular we give
+effective bounds for the saturation numbers for points on such orbits at which
+the value of a given polynomial has few prime factors. In many cases these
+bounds are of the same quality as what is known in the classical case of a
+polynomial in one variable and the orbit is the integers. When the orbit is the
+set of integral matrices of a fixed determinant we obtain a sharp result for
+the saturation number, and thus establish the Zariski density of matrices all
+of whose entries are prime numbers. Among the key tools used are explicit
+approximations to the generalized Ramanujan conjectures for such groups and
+sharp and uniform counting of points on such orbits when ordered by various
+norms.",0902.0692v1
+2009-02-11,Quantum corrections to solitons and BPS saturation,"We review our work of the past decade on one-loop quantum corrections to the
+mass M and central charge Z of solitons in supersymmetric field theories: the
+kink, the vortex, and the monopoles (focussing on the kink and the monopoles
+here). In each case a new feature was needed to obtain BPS saturation: a new
+anomaly-like contribution to Z for the kink and the N=2 monopole, the effect of
+classical winding of the quantum vortex contributing to Z, surface terms
+contributing to M of the N=4 monopole and to Z of the N=2 and N=4 monopoles,
+and composite operator renormalization for the currents of the ""finite"" N=4
+model. We use dimensional regularization, modified to preserve susy and be
+applicable to solitons, and suitable renormalization conditions. In the mode
+expansion of bosonic and fermionic quantum fields, zero modes appear then as
+massless nonzero modes.",0902.1904v1
+2009-04-20,Relaxation in the 3D ordered CoTAC spin chain by quantum nucleation of 0D domain walls,"We have shown that resonant quantum tunnelling of the magnetisation (QTM),
+until now observed only in 0D cluster systems (SMMs), occurs in the molecular
+Ising spin chain, CoTAC ([(CH_3)_3NH]CoCl_3 - 2H_2O) which orders as a canted
+3D-antiferromagnet at T_C=4.15 K. This effect was observed around a resonant
+like field value of 1025 Oe. We present here measurements of the relaxation of
+the magnetisation as a function of time, from the zero field cooled (ZFC)
+antiferromagnet state and from the saturated ferromagnet state. We show that,
+at the resonant field, the relaxation from the saturated state occurs in a
+complicated process, whereas, surprisingly, in the case of the ZFC state, the
+relaxation is exponential.",0904.2984v1
+2009-04-22,Experimental Autoignition of C4-C6 Saturated and Unsaturated Methyl and Ethyl Esters,"Autoignition delay times, ?, of methyl crotonate, methyl acrylate, ethyl
+butanoate, ethyl crotonate, and ethyl acrylate were studied in shock tube
+experiments. A series of mixtures diluted with argon, of varying fuel/oxygen
+equivalence ratios (?=0.25, 0.4, 1.0, and 2.0), were measured behind reflected
+shock waves over the temperature range of 1280-1930 K, pressure range of 7-9.65
+atm, during which the logarithm of ? varies linearly as a function of the
+inverse temperature for all equivalence ratios. The ignition delay time
+decreases as temperature rises. The dependence of ? on temperature, and
+reactant concentrations is given in an empirical correlation. The results
+provide a database for the validation of small saturated and unsaturated esters
+kinetic mechanisms at elevated temperatures and pressure combustion.",0904.3539v1
+2009-04-29,Vapor-liquid equilibria simulation and an equation of state contribution for dipole-quadrupole interactions,"A systematic investigation on vapor-liquid equilibria (VLE) of dipolar and
+quadrupolar fluids is carried out by molecular simulation to develop a new
+Helmholtz energy contribution for equations of state (EOS). Twelve two-center
+Lennard-Jones plus point dipole and point quadrupole model fluids (2CLJDQ) are
+studied for different reduced dipolar moments mu^{*2}=6,12, reduced quadrupolar
+moments Q^{*2}=2,4 and reduced elongations L^*=0, 0.505,1. Temperatures cover a
+wide range from about 55% to about 95% of the critical temperature of each
+fluid. The NpT + test particle method is used for the calculation of vapor
+pressure, saturated densities and saturated enthalpies.Critical data and the
+acentric factor are obtained from fits to the simulation data.On the basis of
+this data, an EOS contribution for the dipole-quadrupole cross-interactions of
+non-spherical molecules is developed. The expression is based on a third-order
+perturbation theory and the model constants are adjusted to the present 2CLJDQ
+simulation results. When applied to mixtures, the model is found to be in
+excellent agreement to results from simulation and experiment. The new EOS
+contribution is also compatible with segment-based EOS, like the various forms
+of the Statistical Associating Fluid Theory (SAFT) EOS.",0904.4637v1
+2009-05-04,The Non-Linear Fisher Information content of cosmic shear surveys,"We quantify the Fisher information content of the cosmic shear survey
+two-point function as a function of noise and resolution. The two point
+information of dark matter saturates at the trans-linear scale. We investigate
+the impact of non-linear non-Gaussianity on the information content for
+lensing, which probes the same dark matter. To do so we heavily utilize N-body
+simulations in order to probe accurately the non-linear regime. While we find
+that even in a perfect survey, there is no clear saturation scale, we observe
+that non-linear growth induced non-Gaussianity could lead to a factor of ~4
+reduction for the common Dark Energy figure of merit. This effect is however
+mitigated by realistic levels of shot noise and we find that for future
+surveys, the effect is closer to a factor of 1.5. To do so, we develop a new
+scheme to compute the relevant covariant matrix. It leads us to claim an
+unbiased estimator with an order of magnitude improvement in accuracy with only
+twice more simulations than previously used. Finally, we evaluate the error on
+the errors using bootstrap methods.",0905.0501v1
+2009-05-05,Relativistic calculation of the pion loop correlation energy in nuclear matter in a theory including confinement,"We present a relativistic calculation of the saturation properties of nuclear
+matter which contains the correlation energy. Pion loops are incorporated on
+top of a relativistic Hartree-Fock (RHF) approach based on a chiral theory. It
+includes the effect of nucleon structure through its response to the background
+chiral invariant scalar field. All the parameters which enter the RHF
+calculation are fixed or strongly constrained by hadron phenomenology or
+lattice data. The new input for the correlation energy is the Landau-Migdal
+parameter g? governing the short-range part of the spin-isospin interaction. We
+find that the inclusion of the correlation energy improves the description of
+the saturation properties of nuclear matter.",0905.0605v1
+2009-05-06,Scaling in Plateau-to-Plateau Transition: A Direct Connection of Quantum Hall Systems with Anderson Localization Model,"The quantum Hall plateau transition was studied at temperatures down to 1 mK
+in a random alloy disordered high mobility two-dimensional electron gas. A
+perfect power-law scaling with \kappa=0.42 was observed from 1.2K down to 12mK.
+This perfect scaling terminates sharply at a saturation temperature of
+T_s~10mK. The saturation is identified as a finite-size effect when the quantum
+phase coherence length (L_{\phi} ~ T^{-p/2}) reaches the sample size (W) of
+millimeter scale. From a size dependent study, T_s \propto W^{-1} was observed
+and p=2 was obtained. The exponent of the localization length, determined
+directly from the measured \kappa and p, is \nu=2.38, and the dynamic critical
+exponent z = 1.",0905.0885v1
+2009-05-11,Spatial and temporal features of dense contaminant transport: experimental investigation and numerical modeling,"We investigate the spatial and temporal features of dense contaminant plumes
+dynamics in porous materials. Our analysis is supported by novel experimental
+results concerning pollutant concentration profiles inside a vertical column
+setup. We describe the experimental methods and elucidate the salient outcomes
+of the measurements, with focus on miscible fluids in homogeneous saturated
+media. By resorting to a finite elements approach, we numerically solve the
+equations that rule the pollutants migration and compare the simulation results
+with the experimental data. Finally, we qualitatively explore the interfacial
+dynamics behavior between the dense contaminant plume and the lighter resident
+fluid that saturates the column.",0905.1575v1
+2009-05-18,Long-term evolution and gravitational wave radiation of neutron stars with differential rotation induced by r-modes,"In a second-order r-mode theory, S'a & Tom'e found that the r-mode
+oscillation in neutron stars (NSs) could induce stellar differential rotation,
+which leads to a saturation state of the oscillation spontaneously. Based on a
+consideration of the coupling of the r-modes and the stellar spin and thermal
+evolutions, we carefully investigate the influences of the r-mode-induced
+differential rotation on the long-term evolutions of isolated NSs and NSs in
+low-mass X-ray binaries, where the viscous damping of the r-modes and its
+resultant effects are taken into account. The numerical results show that, for
+both kinds of NSs, the differential rotation can prolong the duration of the
+r-mode saturation state significantly. As a result, the stars can keep nearly
+constant temperature and angular velocity over a thousand years. Moreover, due
+to the long-term steady rotation of the stars, persistent quasi-monochromatic
+gravitational wave radiation could be expected, which increases the
+detectibility of gravitational waves from both nascent and accreting old NSs.",0905.2804v1
+2009-05-26,Resonance saturation at next-to-leading order,"A proper estimation of the chiral low-energy constants of Chiral Perturbation
+Theory is a very important task. To this end resonance chiral Lagrangians have
+been used fruitfully. We have studied the determination of chiral couplings at
+next-to-leading (NLO) order in the 1/N(C) expansion, keeping full control of
+the renormalization scale dependence. We find that, by imposing short-distance
+constraints coming from QCD, resonance saturation at NLO in 1/N(C) is
+satisfied. In other words, the chiral couplings can be written in terms of the
+resonance masses and couplings and do not depend explicitly on the coefficients
+of the chiral operators in the Goldstone boson sector of Resonance Chiral
+Theory.",0905.4299v1
+2009-06-01,A class of stable perturbations for a minimal mass soliton in three dimensional saturated nonlinear Schrödinger equations,"In this result, we develop the techniques of \cite{KS1} and \cite{BW} in
+order to determine a class of stable perturbations for a minimal mass soliton
+solution of a saturated, focusing nonlinear Schr\""odinger equation {c} i u_t +
+\Delta u + \beta (|u|^2) u = 0 u(0,x) = u_0 (x), in $\reals^3$. By projecting
+into a subspace of the continuous spectrum of $\mathcal{H}$ as in \cite{S1},
+\cite{KS1}, we are able to use a contraction mapping similar to that from
+\cite{BW} in order to show that there exist solutions of the form e^{i
+\lambda_{\min} t} (R_{min} + e^{i \mathcal{H} t} \phi + w(x,t)), where $e^{i
+\mathcal{H} t} \phi + w(x,t)$ disperses as $t \to \infty$. Hence, we have long
+time persistance of a soliton of minimal mass despite the fact that these
+solutions are shown to be nonlinearly unstable in \cite{CP1}.",0906.0375v2
+2009-06-08,CMB Constraints on WIMP Annihilation: Energy Absorption During the Recombination Epoch,"We compute in detail the rate at which energy injected by dark matter
+annihilation heats and ionizes the photon-baryon plasma at z ~ 1000, and
+provide accurate fitting functions over the relevant redshift range for a broad
+array of annihilation channels and DM masses. The resulting perturbations to
+the ionization history can be constrained by measurements of the CMB
+temperature and polarization angular power spectra. We show that models which
+fit recently measured excesses in 10-1000 GeV electron and positron cosmic rays
+are already close to the 95% confidence limits from WMAP. The recently launched
+Planck satellite will be capable of ruling out a wide range of DM explanations
+for these excesses. In models of dark matter with Sommerfeld-enhanced
+annihilation, where sigma v rises with decreasing WIMP velocity until some
+saturation point, the WMAP5 constraints imply that the enhancement must be
+close to saturation in the neighborhood of the Earth.",0906.1197v2
+2009-06-08,Semi-inclusive Deep Inelastic Scattering at small x,"We study the semi-inclusive hadron production in deep inelastic scattering at
+small $x$. A transverse momentum dependent factorization is found consistent
+with the results calculated in the small-$x$ approaches, such as the
+color-dipole framework and the color glass condensate, in the appropriate
+kinematic region at the lowest order. The transverse momentum dependent quark
+distribution can be studied in this process as a probe for the small-$x$
+saturation physics. Especially, the ratio of quark distributions as a function
+of transverse momentum at different $x$ demonstrates strong dependence on the
+saturation scale. The $Q^2$ dependence of the same ratio is also studied by
+applying the Collins-Soper-Sterman resummation method.",0906.1454v2
+2009-06-09,Discrete Family of Dissipative Soliton Pairs in Mode-Locked Fiber Lasers,"We numerically investigate the formation of soliton pairs (bound states) in
+mode-locked fiber ring lasers. In the distributed model (complex cubic-quintic
+Ginzburg-Landau equation) we observe a discrete family of soliton pairs with
+equidistantly increasing peak separation. This family was identified by two
+alternative numerical schemes and the bound state instability was disclosed by
+a linear stability analysis. Moreover, similar families of unstable bound state
+solutions have been found in a more realistic lumped laser model with an
+idealized saturable absorber (instantaneous response). We show that a
+stabilization of these bound states can be achieved when the finite relaxation
+time of the saturable absorber is taken into account. The domain of stability
+can be controlled by varying this relaxation time.",0906.1589v1
+2009-06-11,On the background estimation by time slides in a network of gravitational wave detectors,"Time shifting the outputs of Gravitational Wave detectors operating in
+coincidence is a convenient way to estimate the background in a search for
+short duration signals. However this procedure is limited as increasing
+indefinitely the number of time shifts does not provide better estimates. We
+show that the false alarm rate estimation error saturates with the number of
+time shifts. In particular, for detectors with very different trigger rates
+this error saturates at a large value. Explicit computations are done for 2
+detectors, and for 3 detectors where the detection statistic relies on the
+logical ``OR'' of the coincidences of the 3 couples in the network.",0906.2120v2
+2009-06-25,Sound speed in water-saturated glass beads as a function of frequency and porosity,"Sound propagation in water-saturated granular sediments is known to depend on
+the sediment porosity, but few data in the literature address both the
+frequency and porosity dependency. To begin to address this deficiency, a
+fluidized bed technique was used to control the porosity of an artificial
+sediment composed of glass spheres of 265 {\mu}m diameter. Time-of-flight
+measurements and the Fourier phase technique were utilized to determine the
+sound speed for frequencies from 300 to 800 kHz and porosities from 0.37 to
+0.43. A Biot-based model qualitatively describes the porosity dependence.",0906.4798v2
+2009-06-27,Multiphase modeling and qualitative analysis of the growth of tumor cords,"In this paper a macroscopic model of tumor cord growth is developed, relying
+on the mathematical theory of deformable porous media. Tumor is modeled as a
+saturated mixture of proliferating cells, extracellular fluid and extracellular
+matrix, that occupies a spatial region close to a blood vessel whence cells get
+the nutrient needed for their vital functions. Growth of tumor cells takes
+place within a healthy host tissue, which is in turn modeled as a saturated
+mixture of non-proliferating cells. Interactions between these two regions are
+accounted for as an essential mechanism for the growth of the tumor mass. By
+weakening the role of the extracellular matrix, which is regarded as a rigid
+non-remodeling scaffold, a system of two partial differential equations is
+derived, describing the evolution of the cell volume ratio coupled to the
+dynamics of the nutrient, whose higher and lower concentration levels determine
+proliferation or death of tumor cells, respectively. Numerical simulations of a
+reference two-dimensional problem are shown and commented, and a qualitative
+mathematical analysis of some of its key issues is proposed.",0906.5077v1
+2009-06-29,Multi-$\bar{K}$ hypernuclei,"Relativistic mean field calculations of multi-$\bar{K}$ hypernuclei are
+performed by adding $K^-$ mesons to particle-stable configurations of nucleons,
+$\Lambda$ and $\Xi$ hyperons. For a given hypernuclear core, the calculated
+$\bar{K}$ separation energy $B_{\bar{K}}$ saturates with the number of
+$\bar{K}$ mesons for more than roughly 10 mesons, with $B_{\bar{K}}$ bounded
+from above by 200 MeV. The associated baryonic densities saturate at values 2-3
+times nuclear-matter density within a small region where the $\bar{K}$-meson
+densities peak, similarly to what was found for multi-$\bar{K}$ nuclei. The
+calculations demonstrate that particle-stable multistrange $\{N,\Lambda,\Xi \}$
+configurations are stable against strong-interaction conversions $\Lambda \to N
+\bar{K}$ and $\Xi \to N \bar{K} \bar{K}$, confirming and strengthening the
+conclusion that kaon condensation is unlikely to occur in strong-interaction
+self-bound strange hadronic matter.",0906.5344v2
+2009-07-03,Dissipation effects in the ratchetlike Fermi acceleration,"Ac driven asymmetric pulses can be used to control the Fermi acceleration
+between three different motions, ${\bf A:}$ the {\it accelerated} mode; ${\bf
+D:}$ the {\it decelerated} mode and ${\bf H:}$ the {\it hyperaccelerated} mode.
+In this work we show that dissipation strongly affects the particles velocity,
+reducing the possibility for an accurate control of the dynamics. The
+saturation time, where the mean velocity starts to be constant due to
+dissipation, decays with a power law $\sim\gamma^{-\beta}$, where $\gamma$ is
+the dissipation parameter and $\beta$ is close to 1. The value of the saturated
+mean velocity also decays with a power law with exponent $\beta\sim0.6$ for the
+case ${\bf H}$, and $\beta\sim0.3$ for the case ${\bf A}$. In the case ${\bf
+D}$ this velocity is almost constant for small dissipations.",0907.0628v1
+2009-07-20,Testing Non-linear Evolution with Running Coupling Corrections in $ep$ and $pp$ collisions,"The perturbative QCD predicts that the growth of the gluon density at
+small-$x$ (high energies) should saturate, forming a Color Glass Condensate
+(CGC), which is described in mean field approximation by the Balitsky-Kovchegov
+(BK) equation. Recently, the next-to-leading order corrections for the BK
+equation were derived and a global fit of the inclusive $ep$ HERA data was
+performed, resulting in a parameterization for the forward scattering
+amplitude. In this paper we compare this parameterization with the predictions
+of other phenomenological models and investigate the saturation physics in
+diffractive deep inelastic electron-proton scattering and in the forward hadron
+production in $pp$ collisions. Our results demonstrate that the running
+coupling BK solution is able to describe these observables.",0907.3416v2
+2009-07-21,"Wavet, a Custom Device Able to Measure Viscoelastic Properties of Wood Under Water-Saturated Conditions Up to 140 deg C (WAVET : Environmental Vibration Analyser for Wood)","This work presents an innovative experimental device conceived to
+characterize the time-dependent behavior of hygroscopic materials, as wood, at
+controlled moisture content and temperature. This device, the WAVET, permits
+the determination of the viscoelastic properties of samples, using harmonic
+tests at frequencies varying from 5.10-3 Hz to 10 Hz. Conceived to work up to 5
+bar, it allows tests in dry or water-saturated conditions to be performed over
+the temperature range 0\degree C to 140\degree C. In spite of these severe
+working conditions, the careful device design, together with a rigorous data
+analysis, allows a rigorous determination of the storage and loss modulus and
+the loss factor. The results collected for several species of wood emphasize
+the ability of the WAVET to underline the influence of numerous parameters,
+namely specie, material direction, anatomical and macromolecular structure, on
+the rheological properties and notably on the softening temperature. The WAVET
+also establishes a efficient tool to follow the modifications of the
+constitutive amorphous polymers of materials submitted to hydrothermal
+treatments, in relation to the evolution of their viscoelastic properties.",0907.3676v1
+2009-07-27,Understanding saturation and AA collisions with an eA collider,"The initial conditions in high energy nucleus-nucleus collisions are
+determined by the small momentum fraction part of the nuclear wavefunction.
+This is the regime of gluon saturation and the most direct way to
+experimentally study it would be deep inelastic scattering at a high energy
+electron ion collider (EIC). This talk discusses some of the connections
+between physics at the EIC and the initial stage of relativistic heavy ion
+collisions. We argue that measurements at an EIC will provide detailed
+high-precision information about the parameters for the initial conditions,
+transverse geometry and longitudinal correlations that will be crucial in
+understanding the initial stage of a heavy ion collision.",0907.4588v2
+2009-09-16,Influence of wettability on liquid water transport in gas diffusion layer of proton exchange membrane fuel cells (PEMFC),"Water management is a key factor that limits PEFC's performance. We show how
+insights into this problem can be gained from pore-scale simulations of water
+invasion in a model fibrous medium. We explore the influence of contact angle
+on the water invasion pattern and water saturation at breakthrough and show
+that a dramatic change in the invasion pattern, from fractal to compact, occurs
+as the system changes from hydrophobic to hydrophilic. Then, we explore the
+case of a system of mixed wettability, i.e. containing both hydrophilic and
+hydrophobic pores. The saturation at breakthrough is studied as a function of
+the fraction of hydrophilic pores. The results are discussed in relation with
+the water management problem, the optimal design of a GDL and the fuel cell
+performance degradation mechanisms. We outline how the study could be extended
+to 3D systems, notably from binarised images of GDLs obtained by X ray
+microtomography.",0909.2947v1
+2009-09-18,Analyse en dépendances à l'aide des grammaires d'interaction,"This article proposes a method to extract dependency structures from
+phrase-structure level parsing with Interaction Grammars. Interaction Grammars
+are a formalism which expresses interactions among words using a polarity
+system. Syntactical composition is led by the saturation of polarities.
+Interactions take place between constituents, but as grammars are lexicalized,
+these interactions can be translated at the level of words. Dependency
+relations are extracted from the parsing process: every dependency is the
+consequence of a polarity saturation. The dependency relations we obtain can be
+seen as a refinement of the usual dependency tree. Generally speaking, this
+work sheds new light on links between phrase structure and dependency parsing.",0909.3444v1
+2009-09-30,Large energy soliton erbium-doped fiber laser with a graphene-polymer composite mode locker,"Due to its unique electronic property and the Pauli Blocking Principle,
+atomic layer graphene possesses wavelength-independent ultrafast saturable
+absorption, which can be exploited for the ultrafast photonics application.
+Through chemical functionalization, a graphene-polymer nanocomposite membrane
+was fabricated and firstly used to mode lock a fiber laser. Stable mode locked
+solitons with 3 nJ pulse energy, 700 fs pulse width at the 1590 nm wavelength
+have been directly generated from the laser. We show that graphene-polymer
+nanocomposites could be an attractive saturable absorber for high power fiber
+laser mode locking.",0909.5540v1
+2009-10-16,A continuous time random walk model of transport in variably saturated heterogeneous porous media,"We propose a unified physical framework for transport in variably saturated
+porous media. This approach allows fluid flow and solute migration to be
+treated as ensemble averages of fluid and solute particles, respectively. We
+consider the cases of homogeneous and heterogeneous porous materials. Within a
+fractal mobile-immobile (MIM) continuous time random walk framework, the
+heterogeneity will be characterized by algebraically decaying particle
+retention-times. We derive the corresponding (nonlinear) continuum limit
+partial differential equations and we compare their solutions to Monte Carlo
+simulation results. The proposed methodology is fairly general and can be used
+to track fluid and solutes particles trajectories, for a variety of initial and
+boundary conditions.",0910.3044v1
+2009-10-27,Low density symmetry energy effects in the neutron star crust properties,"The form of the nuclear symmetry energy $E_s$ around saturation point density
+leads to a different crust-core transition point in the neutron star and affect
+the crust properties. We show that the knowledge about $E_s$ close to the
+saturation point is not sufficient, because the very low density behaviour is
+relevant. We also claim that crust properties are strongly influenced by the
+very high density behavior of $E_s$, so in order to conclude about the form of
+low density part of the symmetry energy one must isolate properly the high
+density part.",0910.5066v3
+2009-10-27,Casimir experiments showing saturation effects,"We address several different Casimir experiments where theory and experiment
+disagree. First out is the classical Casimir force measurement between two
+metal half spaces; here both in the form of the torsion pendulum experiment by
+Lamoreaux and in the form of the Casimir pressure measurement between a gold
+sphere and a gold plate as performed by Decca et al.; theory predicts a large
+negative thermal correction, absent in the high precision experiments. The
+third experiment is the measurement of the Casimir force between a metal plate
+and a laser irradiated semiconductor membrane as performed by Chen et al.; the
+change in force with laser intensity is larger than predicted by theory. The
+fourth experiment is the measurement of the Casimir force between an atom and a
+wall in the form of the measurement by Obrecht et al. of the change in
+oscillation frequency of a 87 Rb Bose-Einstein condensate trapped to a fused
+silica wall; the change is smaller than predicted by theory. We show that
+saturation effects can explain the discrepancies between theory and experiment
+observed in all these cases.",0910.5137v1
+2009-10-31,Saturated fusion systems as idempotents in the double Burnside ring,"We give a new, unexpected characterization of saturated fusion systems on a
+p-group S in terms of idempotents in the p-local double Burnside ring of S that
+satisfy a Frobenius reciprocity relation, and reformulate fusion-theoretic
+phenomena in the language of idempotents. Interpreting our results in stable
+homotopy, we answer a long-standing question on stable splittings of
+classifying spaces of finite groups, and generalize the Adams--Wilkerson
+criterion for recognizing rings of invariants in the cohomology of an
+elementary abelian p-group. This work is partly motivated by a conjecture of
+Haynes Miller which proposes retractive transfer triples as a purely
+homotopy-theoretic model for p-local finite groups. We take an important step
+toward proving this conjecture by showing that a retractive transfer triple
+gives rise to a p-local finite group when two technical assumptions are made,
+thus reducing the conjecture to proving those two assumptions.",0911.0085v3
+2009-11-07,Femtosecond carrier dynamics and saturable absorption in graphene suspensions,"Nonlinear optical properties and carrier relaxation dynamics in graphene,
+suspended in three different solvents, are investigated using femtosecond (80
+fs pulses) Z-scan and degenerate pumpprobe spectroscopy at 790 nm. The results
+demonstrate saturable absorption property of graphene with a nonlinear
+absorption coefficient, $beta$, of ~2 to 9x10^-8 cm/W. Two distinct time scales
+associated with the relaxation of photoexcited carriers, a fast one in the
+range of 130-330 fs (related to carrier-carrier scattering) followed by a
+slower one in 3.5-4.9 ps range (associated with carrier-phonon scattering) are
+observed.",0911.1415v2
+2009-11-10,"Twist expansion of the nucleon structure functions, F2 and FL, in the DGLAP improved saturation model","Higher twist effects in the deeply inelastic scattering are studied. We start
+with a short review of the theoretical results on higher twists in QCD. Within
+the saturation model we perform a twist analysis of the nucleon structure
+functions FT and FL at small value of the Bjorken variable x. The parameters of
+the model are fitted to the HERA F2 data, and we derive a prediction for the
+longitudinal structure function FL. We conclude that for FL the higher twist
+corrections are sizable whereas for F2 = FT + FL there is a nearly complete
+cancellation of twist-4 corrections in FT and FL. We discuss a few consequences
+for future LHC measurements.",0911.1935v1
+2009-11-19,Strongly coupled Skyrme-Faddeev-Niemi hopfions,"The strongly coupled limit of the Skyrme-Faddeev-Niemi model (i.e., without
+quadratic kinetic term) with a potential is considered on the spacetime S^3 x
+R. For one-vacuum potentials two types of exact Hopf solitons are obtained.
+Depending on the value of the Hopf index, we find compact or non-compact
+hopfions. The compact hopfions saturate a Bogomolny bound and lead to a
+fractional energy-charge formula E \sim |Q|^{1/2}, whereas the non-compact
+solitons do not saturate the bound and give E \sim |Q|. In the case of
+potentials with two vacua compact shell-like hopfions are derived. Some remarks
+on the influence of the potential on topological solutions in the full
+Skyrme-Faddeev-Niemi model or in (3+1) Minkowski space are also made.",0911.3673v3
+2009-11-25,Nonlinear pair production in scattering of photons on ultra-short laser pulses at high energy,"We consider scattering of a photon on a short intense laser pulse at high
+energy. We argue that for ultra-short laser pulses the interaction is coherent
+over the entire length of the pulse. At low pulse intensity $I$ the total cross
+section for electron-positron pair production is proportional to $I$. However,
+at pulse intensities higher than the characteristic value $I_s$, the total
+cross section saturates -- it becomes proportional to the logarithm of
+intensity. This nonlinear effect is due to multi-photon interactions. We derive
+the total cross section for pair production at high energies by resuming the
+multi-photon amplitudes to all orders in intensity. We calculate the saturation
+intensity $I_s$ and show that it is significantly lower than the Schwinger's
+critical value. We discuss possible experimental tests.",0911.4964v2
+2009-12-15,Zero-range processes with saturated condensation: the steady state and dynamics,"We study a class of zero-range processes in which the real-space condensation
+phenomenon does not occur and is replaced by a saturated condensation: that is,
+an extensive number of finite-size ""condensates"" in the steady state. We
+determine the conditions under which this occurs, and investigate the dynamics
+of relaxation to the steady state. We identify two stages: a rapid initial
+growth of condensates followed by a slow process of activated evaporation and
+condensation. We analyze these nonequilibrium dynamics with a combination of
+meanfield approximations, first-passage time calculations and a
+fluctuation-dissipation type approach.",0912.3009v2
+2009-12-21,Statistical and coherence properties of radiation from X-ray free electron lasers,"We describe statistical and coherence properties of the radiation from x-ray
+free electron lasers (XFEL). It is shown that the X-ray FEL radiation before
+saturation is described with gaussian statistics. Particularly important is the
+case of the optimized X-ray FEL, studied in detail. Applying similarity
+techniques to the results of numerical simulations allowed us to find universal
+scaling relations for the main characteristics of an X-ray FEL operating in the
+saturation regime: efficiency, coherence time and degree of transverse
+coherence. We find that with an appropriate normalization of these quantities,
+they are functions of only the ratio of the geometrical emittance of the
+electron beam to the radiation wavelength. Statistical and coherence properties
+of the higher harmonics of the radiation are highlighted as well.",0912.4161v1
+2010-01-07,AdS black disk model for small-x DIS,"Using the approximate conformal invariance of QCD at high energies we
+consider a simple AdS black disk model to describe saturation in DIS. Deep
+inside saturation the structure functions have the same power law scaling, F_T
+~ F_L ~ 1/x^w, where w is related to the expansion rate of the black disk with
+energy. Furthermore, the ratio F_L /F_T is given by the universal value
+(1+w)/(3+w), independently of the target. For virtual photon-photon scattering
+at high energies we obtain explicit expressions and ratios for the total cross
+sections of transverse and longitudinal photons in terms of the single
+parameter w.",1001.1157v2
+2010-01-12,Bulk sensitive x-ray absorption spectroscopy free of self-absorption effects,"We demonstrate a new method of x-ray absorption spectroscopy (XAS) that is
+bulk sensitive, like traditional fluorescence yield measurements, but is not
+affected by self-absorption or saturation effects. This measure of XAS is
+achieved by scanning the incident photon energy through an absorption edge and
+using an energy sensitive photon detector to measure the partial fluorescence
+yield (PFY). The x-ray emission from any element or core-hole excitation that
+is not resonant with the absorption edge under investigation is selected from
+the PFY. It is found that the inverse of this PFY spectrum, which we term
+inverse partial fluorescence yield (IPFY), is linearly proportional to the
+x-ray absorption cross-section without any corrections due to saturation or
+self-absorption effects. We demonstrate this technique on the Cu L and Nd M
+absorption edges of the high-Tc cuprate LNSCO by measuring the O K PFY and
+comparing the total electron yield, total fluorescence yield and IPFY spectra.",1001.1925v2
+2010-02-01,On saturation of betatron acceleration of dust particles behind shock fronts,"Possible saturation of betatron acceleration of dust particles behind strong
+shock fronts from supernovae is considered. It is argued that the efficiency of
+the nonthermal dust destruction should be substantially lower than the value
+estimated from a traditional description of betatron acceleration of dust
+grains behind radiative shock waves. The inhibition of the nonthermal
+destruction can be connected with the mirror instability developed in the dust
+component behind strong shocks with the velocity 3 times exceeding the Alfv\'en
+speed. The instability develops on characteristic time scales much shorter the
+age of a supernova remnant, thus its influence on the efficiency of dust
+destruction can be substantial: in the range of shock velocities 100 km
+s$^{-1}<v_s<300$ km s$^{-1}$ the destruction efficiency can be an order of
+magnitude lower that normally estimated.",1002.0223v1
+2010-02-15,On Barbs and Labels in Reactive Systems,"Reactive systems (RSs) represent a meta-framework aimed at deriving
+behavioral congruences for those computational formalisms whose operational
+semantics is provided by reduction rules. RSs proved a flexible specification
+device, yet so far most of the efforts dealing with their behavioural semantics
+focused on idem pushouts (IPOs) and saturated (also known as dynamic)
+bisimulations. In this paper we introduce a novel, intermediate behavioural
+equivalence: L-bisimilarity, which is able to recast both its IPO and saturated
+counterparts. The equivalence is parametric with respect to a set L of RSs
+labels, and it is shown that under mild conditions on L it is indeed a
+congruence. Furthermore, L-bisimilarity can also recast the notion of barbed
+semantics for RSs, proposed by the same authors in a previous paper. In order
+to provide a suitable test-bed, we instantiate our proposal by addressing the
+semantics of (asynchronous) CCS and of the calculus of mobile ambients.",1002.2869v1
+2010-03-02,Dynamical correlation functions of the mesoscopic pairing model,"We study the dynamical correlation functions of the Richardson pairing model
+(also known as the reduced or discrete-state BCS model) in the canonical
+ensemble. We use the Algebraic Bethe Ansatz formalism, which gives exact
+expressions for the form factors of the most important observables. By summing
+these form factors over a relevant set of states, we obtain very precise
+estimates of the correlation functions, as confirmed by global sum-rules
+(saturation above 99% in all cases considered). Unlike the case of many other
+Bethe Ansatz solvable theories, simple two-particle states are sufficient to
+achieve such saturations, even in the thermodynamic limit. We provide explicit
+results at half-filling, and discuss their finite-size scaling behavior.",1003.0582v1
+2010-03-17,"Comment on ""Measurement of x-ray absorption spectra of overdoped high-temperature cuprate superconductors: Inapplicability of the single-band Hubbard model""","In a recent Letter, Peets, et al. measured the x-ray intensity at the oxygen
+K-edge in overdoped La$_{2-x}$Sr$_x$CuO$_{4\pm\delta}$ (LSCO) and
+Tl$_2$Ba$_2$CuO$_{6+\delta}$. They claimed that, unlike the underdoped samples
+of LSCO and YBa$_2$Cu$_3$O$_x$ in which the integrated intensity increases at
+least linearly with doping, it saturates abruptly for a hole count exceeding
+$x\approx 0.23$. They interpreted the saturation as a breakdown of the 1-band
+Hubbard model in the cuprates. However, we show that their results are in
+quantitative agreement with the 1-band Hubbard model.",1003.3412v2
+2010-03-23,Dynamic Nuclear Polarization in Double Quantum Dots,"We theoretically investigate the controlled dynamic polarization of lattice
+nuclear spins in GaAs double quantum dots containing two electrons. Three
+regimes of long-term dynamics are identified, including the build up of a large
+difference in the Overhauser fields across the dots, the saturation of the
+nuclear polarization process associated with formation of so-called ""dark
+states,"" and the elimination of the difference field. We show that in the case
+of unequal dots, build up of difference fields generally accompanies the
+nuclear polarization process, whereas for nearly identical dots, build up of
+difference fields competes with polarization saturation in dark states. The
+elimination of the difference field does not, in general, correspond to a
+stable steady state of the polarization process.",1003.4508v2
+2010-04-19,Saturation field of frustrated chain cuprates: broad regions of predominant interchain coupling,"An efficient and precise thermodynamic method to extract the interchain
+coupling (IC) of spatially anisotropic 2D or 3D spin-1/2 systems from their
+empirical saturation field H_s (T=0) is proposed. Using density-matrix
+renormalization group, hard-core boson, and spin-wave theory we study how H_s
+is affected by an antiferromagnetic (AFM) IC between frustrated chains
+described in the J_1-J_2-spin model with ferromagnetic 1st and AFM 2nd neighbor
+in-chain exchange. A complex 3D-phase diagram has been found. For Li2CuO2 and
+Y2Ca2Cu5O10, we show that H_s is solely determined by the IC and predict H_s
+approx 61 T for the latter.Using H_s approx 55 T from our high-field pulsed
+measurements one reads out a weak IC for Li2CuO2 close to that from neutron
+scattering.",1004.3300v3
+2010-04-30,"Fluctuations, Saturation, and Diffractive Excitation in High Energy Collisions","Diffractive excitation is usually described by the Good--Walker formalism for
+low masses, and by the triple-Regge formalism for high masses. In the
+Good--Walker formalism the cross section is determined by the fluctuations in
+the interaction. In this paper we show that by taking the fluctuations in the
+BFKL ladder into account, it is possible to describe both low and high mass
+excitation by the Good--Walker mechanism. In high energy $pp$ collisions the
+fluctuations are strongly suppressed by saturation, which implies that pomeron
+exchange does not factorise between DIS and $pp$ collisions. The Dipole Cascade
+Model reproduces the expected triple-Regge form for the bare pomeron, and the
+triple-pomeron coupling is estimated.",1004.5502v2
+2010-05-04,Gluon saturation and inclusive hadron production at LHC,"In high density QCD the hadron production stems from decay of mini-jets that
+have the transverse momenta of the order of the saturation scale. It is shown
+in this paper that this idea is able to describe in a unique fashion both the
+inclusive hadron production for \sqrt{s} \geq 546 GeV including the first data
+from LHC and the deep inelastic scattering at HERA. Recently reported data from
+ALICE, CMS and ATLAS including inclusive charged-hadron transverse-momentum and
+multiplicity distribution in pp collisions are well described in our approach.
+We provide predictions for the upcoming LHC measurements.",1005.0631v2
+2010-05-06,Saturation spectra of low lying states of Nitrogen: reconciling experiment with theory,"The hyperfine constants of the levels 2p2(3P)3s 4P_J, 2p2(3P)3p 4Po_J and
+2p2(3P)3p 4Do_J, deduced by Jennerich et al. [Eur. Phys. J. D 40 (2006) 81]
+from the observed hyperfine structures of the transitions 2p2(3P)3s 4P_J -
+2p2(3P)3p 4Po_J' and 2p2(3P)3s 4P_J - 2p2(3P)3p 4Do_J' recorded by saturation
+spectroscopy in the near-infrared, strongly disagree with the ab initio values
+of J\""onsson et al. [J. Phys. B: At. Mol. Opt. Phys. 43 (2010) 115006]. We
+propose a new interpretation of the recorded weak spectral lines. If the latter
+are indeed reinterpreted as crossover signals, a new set of experimental
+hyperfine constants is deduced, in very good agreement with the ab initio
+predictions.",1005.0953v2
+2010-05-08,Mechanism for current saturation and energy dissipation in graphene transistors,"From a combination of careful and detailed theoretical and experimental
+studies, we demonstrate that the Boltzmann theory including all scattering
+mechanisms gives an excellent account, with no adjustable parameters, of high
+electric field transport in single as well as double-oxide graphene
+transistors. We further show unambiguously that scattering from the substrate
+and superstrate surface optical (SO) phonons governs the high field transport
+and heat dissipation over a wide range of experimentally relevant parameters.
+Models that neglect SO phonons altogether or treat them in a simple
+phenomenological manner are inadequate. We outline possible strategies for
+achieving higher current and complete saturation in graphene devices.",1005.1351v1
+2010-05-20,Large amplitude behavior of the bulk viscosity of dense matter,"We study the bulk viscosity of dense matter, taking into account non-linear
+effects which arise in the large amplitude ""supra-thermal"" region where the
+deviation $\mu_\Delta$ of the chemical potentials from chemical equilibrium
+fulfills $\mu_\Delta>T$. This regime is relevant to unstable modes such as
+r-modes, which grow in amplitude until saturated by non-linear effects. We
+study the damping due to direct and modified Urca processes in hadronic matter,
+and due to nonleptonic weak interactions in strange quark matter. We give
+general results valid for an arbitrary equation of state of dense matter and
+find that the viscosity can be strongly enhanced by supra-thermal effects. Our
+study confirms previous results on quark matter and shows that the non-linear
+enhancement is even stronger in the case of hadronic matter. Our results can be
+applied to calculations of the r-mode-induced spin-down of fast-rotating
+neutron stars, where the spin-down time will depend on the saturation amplitude
+of the r-mode",1005.3769v1
+2010-06-02,Single Phase Slip Limited Switching Current in 1-Dimensional Superconducting Al Nanowires,"An Aluminum nanowire switches from superconducting to normal as the current
+is increased in an upsweep. The switching current (I_s) averaged over upsweeps
+approximately follows the depairing critical current (I_c) but falls below it.
+Fluctuations in I_s exhibit three distinct regions of behaviors and are
+non-monotonic in temperature: saturation well below the critical temperature
+T_c, an increase as T^{2/3} at intermediate temperatures, and a rapid decrease
+close to T_c. Heat dissipation analysis indicates that a single phase slip is
+able to trigger switching at low and intermediate temperatures, whereby the
+T^{2/3} dependence arises from the thermal activation of a phase slip, while
+saturation at low temperatures provides striking evidence that the phase slips
+by macroscopic quantum tunneling.",1006.0420v2
+2010-06-02,Environmentally Activated Tunneling Events in a Hybrid Single-Electron Box,"We have measured individual tunneling events and Coulomb step shapes in
+single-electron boxes with opaque superconductor-normal metal tunnel junctions.
+We observe anomalous broadening of the Coulomb step with decreasing temperature
+in a manner that is consistent with activation of first-order tunneling events
+by an external dissipative electromagnetic environment. We demonstrate that the
+rates for energetically unfavourable tunneling events saturate to finite values
+at low temperatures, and that the saturation level can be suppressed by more
+than an order of magnitude by a capacitive shunt near the device. The findings
+are important in assessing the performance limits of any single-electronic
+device. In particular, master equation based simulations show that the
+electromagnetic environment realized in the capacitively shunted devices allows
+for a metrologically accurate charge pump based on hybrid tunnnel junctions.",1006.0479v3
+2010-06-22,"Saturation and Scaling of Multiplicity, Mean p_T and p_T Distributions from 200 GeV < sqrt{s} < 7 TeV","The multiplicity, average transverse momentum, and charged particle
+transverse momentum distributions have recently been measured in LHC
+experiments. The multiplicity and average transverse momentum grow with beam
+energy. Such growth is expected in the theory of the Color Glass Condensate, a
+theory that incorporates the physics of saturation into the evolution of the
+gluon distribution. We show that the energy dependence of the $p\overline{p}$
+data and the LHC data for $pp$ scattering at \sqrt{s} > 200 GeV may be simply
+described using a minimal amount of model input. Such a description uses
+parameters consistent with the Color Glass Condensate descriptions of HERA and
+RHIC experimental data.",1006.4293v2
+2010-07-26,Measurements of charge carrier mobilities and drift velocity saturation in bulk silicon of <111> and <100> crystal orientation at high electric fields,"The mobility of electrons and holes in silicon depends on many parameters.
+Two of them are the electric field and the temperature. It has been observed
+previously that the mobility in the transition region between ohmic transport
+and saturation velocities is a function of the orientation of the crystal
+lattice.
+  This paper presents a new set of parameters for the mobility as function of
+temperature and electric field for <111> and <100> crystal orientation. These
+parameters are derived from time of flight measurements of drifting charge
+carriers in planar p^+nn^+ diodes in the temperature range between -30{\deg}C
+and 50{\deg}C and electric fields of 2x10^3 V/cm to 2x10^4 V/cm.",1007.4432v2
+2010-08-06,High field transport in graphene,"In this work, high field carrier transport in two dimensional (2D) graphene
+is investigated. Analytical models are applied to estimate the saturation
+currents in graphene, based on the high scattering rate of optical phonon
+emission. Non-equilibrium (hot) phonon effect was studied by Monte Carlo (MC)
+simulations. MC simulation confirms that hot phonon effects play a dominant
+role in current saturation in graphene. Current degradation due to elastic
+scattering events is much smaller compared to the hot phonon effect. Transient
+phenomenon as such as velocity overshoot was also studied using MC simulation.
+The simulation results shows promising potential for graphene to be used in
+high speed electronic devices by shrinking the channel length below 100nm if
+electrostatic control can be exercised in the absence of a band gap.",1008.1161v2
+2010-08-11,Uncovering the Dominant Scatterer in Graphene Sheets on SiO2,"We have measured the impact of atomic hydrogen adsorption on the electronic
+transport properties of graphene sheets as a function of hydrogen coverage and
+initial, pre-hydrogenation field-effect mobility. Our results are compatible
+with hydrogen adsorbates inducing intervalley mixing by exerting a short-range
+scattering potential. The saturation coverages for different devices are found
+to be proportional to their initial mobility, indicating that the number of
+native scatterers is proportional to the saturation coverage of hydrogen. By
+extrapolating this proportionality, we show that the field-effect mobility can
+reach $1.5 \times 10^4$ cm$^2$/V sec in the absence of the hydrogen-adsorbing
+sites. This affinity to hydrogen is the signature of the most dominant type of
+native scatterers in graphene-based field-effect transistors on SiO$_2$.",1008.2007v1
+2010-08-18,Evolution of Holographic Entanglement Entropy after Thermal and Electromagnetic Quenches,"We study the evolution and scaling of the entanglement entropy after two
+types of quenches for a 2+1 field theory, using holographic techniques. We
+study a thermal quench, dual to the addition of a shell of uncharged matter to
+four dimensional Anti-de Sitter (AdS_4) spacetime, and study the subsequent
+formation of a Schwarzschild black hole. We also study an electromagnetic
+quench, dual to the addition of a shell of charged sources to AdS_4, following
+the subsequent formation of an extremal dyonic black hole. In these backgrounds
+we consider the entanglement entropy of two types of geometries, the infinite
+strip and the round disc, and find distinct behavior for each. Some of our
+findings naturally supply results analogous to observations made in the
+literature for lower dimensions, but we also uncover several new phenomena,
+such as (in some cases) a discontinuity in the time derivative of the
+entanglement entropy as it nears saturation, and for the electromagnetic
+quench, a logarithmic growth in the entanglement entropy with time for both the
+disc and strip, before settling to saturation.",1008.3027v2
+2010-08-23,Saturated fusion systems with parabolic families,"Let G be group; a finite p-subgroup S of G is a Sylow p-subgroup if every
+finite p-subgroup of G is conjugate to a subgroup of S. In this paper, we
+examine the relations between the fusion system over S which is given by
+conjugation in G and a certain chamber system C, on which G acts chamber
+transitively with chamber stabilizer N_G(S). Next, we introduce the notion of a
+fusion system with a parabolic family and we show that a chamber system can be
+associated to such a fusion system. We determine some conditions the chamber
+system has to fulfill in order to assure the saturation of the underlying
+fusion system. We give an application to fusion systems with parabolic families
+of classical type.",1008.3815v2
+2010-08-24,Two Particle Correlations at Forward Rapidity in STAR,"During the 2008 run RHIC provided high luminosity in both p+p and d+Au
+collisions at $\sqrt{s_{NN}}= 200$ GeV. Electromagnetic calorimeter acceptance
+in STAR was enhanced by the new Forward Meson Spectrometer (FMS), and is now
+almost contiguous from $-1<\eta<4$ over the full azimuth. This large acceptance
+provides sensitivity to the gluon density in the nucleus down to $x\approx
+10^{-3}$, as expected for $2\rightarrow 2$ parton scattering. Measurements of
+the azimuthal correlation between a forward $\pi^{0}$ and an associated
+particle at large rapidity are sensitive to the low-x gluon density. Data
+exhibit the qualitative features expected from gluon saturation. A comparison
+to calculations using the Color Glass Condensate (CGC) model is presented.",1008.3989v1
+2010-08-30,Initial Conditions and Global Event Properties from Color Glass Condensate,"Perturbative unitarization from non-linear effects is thought to deplete the
+gluon density for transverse momenta below the saturation scale. Such effects
+also modify the distribution of gluons produced in heavy-ion collisions in
+transverse impact parameter space. I discuss some of the consequences for the
+initial conditions for hydrodynamic models of heavy-ion collisions and for hard
+``tomographic'' probes. Also, I stress the importance of realistic modelling of
+the fluctuations of the valence sources for the small-x fields in the impact
+parameter plane. Such models can now be combined with solutions of
+running-coupling Balitsky-Kovchegov evolution to obtain controlled predictions
+for initial conditions at the LHC.",1008.5162v1
+2010-09-07,First-principles calculations of graphene nanoribbons in gaseous environments: Structural and electronic properties,"The stability of graphene nanoribbons in the presence of typical atmospheric
+molecules is systematically investigated by means of density functional theory.
+We calculate the edge formation free energy of five different edge
+configurations passivated by H, H$_2$, O, O$_2$, N$_2$, CO, CO$_2$, and H$_2$O,
+respectively. In addition to the well known hydrogen passivated armchair and
+zig-zag edges, we find the zig-zag edge saturated by oxygen atoms to be
+particularly stable under atmospheric conditions. Saturation by oxygen leads to
+the formation of metallic states strictly localized on the oxygen atoms.
+Finally, the vibrational spectrum of the hydrogen and oxygen passivated ribbons
+are calculated and compared.",1009.1242v2
+2010-09-15,"Symmetric quivers, invariant theory, and saturation theorems for the classical groups","Let G denote either a special orthogonal group or a symplectic group defined
+over the complex numbers. We prove the following saturation result for G: given
+dominant weights \lambda^1, ..., \lambda^r such that the tensor product
+V_{N\lambda^1} \otimes ... \otimes V_{N\lambda^r} contains nonzero G-invariants
+for some N \ge 1, we show that the tensor product V_{2\lambda^1} \otimes ...
+\otimes V_{2\lambda^r} also contains nonzero G-invariants. This extends results
+of Kapovich-Millson and Belkale-Kumar and complements similar results for the
+general linear group due to Knutson-Tao and Derksen-Weyman. Our techniques
+involve the invariant theory of quivers equipped with an involution and the
+generic representation theory of certain quivers with relations.",1009.3040v2
+2010-10-22,Surface Polar Phonon Dominated Electron Transport in Graphene,"The effects of surface polar phonons on electronic transport properties of
+monolayer graphene are studied by using a Monte Carlo simulation. Specifically,
+the low-field electron mobility and saturation velocity are examined for
+different substrates (SiC, SiO2, and HfO2) in comparison to the intrinsic case.
+While the results show that the low-field mobility can be substantially reduced
+by the introduction of surface polar phonon scattering, corresponding
+degradation of the saturation velocity is not observed for all three substrates
+at room temperature. It is also found that surface polar phonons can influence
+graphene electrical resistivity even at low temperature, leading potentially to
+inaccurate estimation of the acoustic phonon deformation potential constant.",1010.4772v1
+2010-11-03,Transitions to three-dimensional flows in a cylinder driven by oscillations of the sidewall,"The transition from two-dimensional to three-dimensional flows in a finite
+circular cylinder driven by an axially oscillating sidewall is explored in
+detail. The complete symmetry group of this flow, including a spatio-temporal
+symmetry related to the oscillating sidewall, is $Z_2\times O(2)$. Previous
+studies in flows with the same symmetries, such as symmetric bluff-body wakes
+and periodically forced rectangular cavities, were unable to obtain the
+theoretically predicted bifurcation to modulated traveling waves. In the
+simpler cylindrical geometry, where the azimuthal direction is physically
+periodic, we have found these predicted modulated traveling waves as stable
+fully saturated nonlinear solutions for the first time. A careful analysis of
+the base states and their linear stability identifies different parameter
+regimes where three-dimensional states that are either synchronous with the
+forcing or quasiperiodic, corresponding to different symmetry-breaking
+processes. These results are in good agreement with theoretical predictions and
+previous results in similar flows. These different regimes are separated by
+three codimension-two bifurcation points that are yet to be fully analyzed
+theoretically. Finally, the saturated nonlinear states and their properties in
+different parameter regimes are analyzed.",1011.1029v1
+2010-11-15,"Saturation and Scaling of Multiplicity, Mean p_T and p_T Distributions from 200 GeV < sqrt{s} < 7 TeV - Addendum","In the previous paper we have argued that the LHC data on multiplicity,
+average transverse momentum, and charged particle transverse momentum
+distributions are well described with minimal modeling in terms of a saturation
+scale Q_sat(s). As a consequence, the p_T spectra should exhibit geometric
+scaling. In this short note we show that recently released CMS data at
+sqrt{s}=0.9, 2.36 and 7 TeV fall on a universal curve when plotted in terms of
+suitably defined scaling variable \tau.",1011.3403v3
+2010-11-16,Forcibly driven coherent soft phonons in GeTe with intense THz-rate pump fields,"We propose an experimental technique to generate large amplitude coherent
+phonons with irradiation of THz-rate pump pulses and to study the dynamics of
+phase transition in GeTe ferroelectrics. When a single pump pulse irradiates
+the sample at various pump power densities, the frequency of the soft phonon
+decreases sub-linearly and saturates at higher pump powers. By contrast, when
+THz-rate pump pulse sequence irradiates the sample at matched time intervals to
+forcibly drive the oscillation, a large red-shift of the phonon frequency is
+observed without saturation effects. After excitation with a four pump pulse
+sequence, the coherent soft phonon becomes strongly damped leading to a near
+critical damping condition. This condition indicates that the lattice is driven
+to a precursor state of the phase transition.",1011.3624v2
+2010-11-18,Scalar field in nuclear matter: the roles of spontaneous chiral symmetry breaking and nucleon structure,"Chiral theories with spontaneous symmetry breaking such as the
+Nambu-Jona-Lasinio (NJL) model lead to the existence of a scalar mode. We
+present in a detailed manner how the corresponding low momentum effective
+lagrangian involving the scalar field can be constructed starting from the NJL
+model. We discuss the relevance of the scalar mode for the problem of the
+nuclear binding and saturation. We show that it depends on the nucleon mass
+origin with two extreme cases. If this origin is entirely due to confinement
+the coupling of this mode to the nucleons vanishes, making it irrelevant for
+the nuclear binding problem. If instead it is entirely due to spontaneous
+symmetry breaking it couples to the nucleons but nuclear matter collapses. It
+is only in the case of a mixed origin with spontaneous breaking that nuclear
+matter can be stable and reach saturation. We describe models of nucleon
+structure where this balance is achieved. We also show how chiral constraints
+and confinement modify the QCD sum rules for the mass evolution in nuclear
+matter.",1011.4280v1
+2010-11-21,Asymptotic analysis of stresses near a crack tip in a two dimensional colloidal packing saturated with liquid,"The consolidation of colloidal particles in drying colloidal dispersions is
+influenced by various factors such as particle size and shape, and
+inter-particle potential. The capillary pressure induced by the menisci, formed
+between the top layer of particles in the packed bed, compresses the bed of
+particles while the constraints enforced by the boundaries result in tensile
+stresses in the packing. Presence of flaws or defects in the bed determines its
+ultimate strength under such circumstances. In this study, we determine the
+asymptotic stress distribution around a flaw in a two dimensional colloidal
+packing saturated with liquid and compare the results with those obtained from
+the full numerical solution of the problem. Using the Griffith's criterion for
+equilibrium cracks, we relate the critical capillary pressure at equilibrium to
+the crack size and the mechanical properties of the packed bed. The analysis
+also gives the maximum allowable flaw size for obtaining a crack free packing.",1011.4626v2
+2010-11-23,Detection of saturated absorption spectroscopy at high sensitivity with displaced crossovers,"We present an experimental approach to detect the saturated absorption
+spectroscopy different from conventional scheme. Using this approach,
+crossovers are removed to avoid their overlap with other peaks in the spectrum
+and sensitivity of detection could be enhanced, so the spectrum could reflect
+energy structure of atoms more explicitly. On the other hand, without harmful
+influence from crossovers, locking range of the error signal is significantly
+increased and symmetry of the dispersion line shape is perfectly reserved, so
+reliability of frequency stabilization could be improved.",1011.5145v3
+2010-11-29,Topographic phase boundary shifts and saturation for anisotropic ion straggle during sputter etching,"Surfaces sputtered by ion beam bombardment have been known to exhibit
+patterns whose behavior is modeled with stochastic partial differential
+equations. A widely accepted model is the Cuerno-Barabasi model which is robust
+in its predictions of sputtered surface morphologies. An understanding of the
+factors responsible for such surface topographies can be achieved by using
+scaling arguments on the stochastic model. For such explanations, knowledge of
+the coefficients is crucial. The more so since these vary with different
+materials, the sputtering process itself generates non-equilibrium surfaces
+within some finite timescale, and the implication of recent results of surface
+topographies unexplained by the continuum theory. We calculate and study these
+coefficients as functions of the sputtering parameters for yet unreported cases
+of anisotropic ion energy distribution within the sputtered material.
+Consequently, we present phase diagrams for the significant case of anisotropic
+ion straggle. We observe shifts in the phase boundaries when the collision
+cascade geometry rotates, and we also found saturation behavior in the
+diagrams; in which case the boundaries become independent of the penetration
+depths. Our results indicate a possible origin of yet unexplained nanodot
+topographies arising from oblique incidence ion etching of amorphized surfaces.",1011.6234v1
+2010-12-19,Breakdown of kT-factorization and J/Psi production in dA collisions,"In spite of the sweeping coherence effects in high energy hadron and nuclei
+collisions, $k_T$-factorization can be recovered for the inclusive gluon
+production in $pA$ collisions at the leading logarithmic order. In open charm
+production at RHIC $k_T$-factorization holds numerically with about 10-20%
+accuracy. This allows to extrapolate the cold nuclear matter effect observed in
+light and charm meson production in $dA$ collisions to that in $AA$ ones.
+Unlike the open charm, the breakdown of factorization in $J/\psi$ production is
+severe. Indeed, already at the lowest order in gluon density the main
+contribution to the inclusive cross section is proportional to the square of
+gluon density in the nucleus. As a consequence, one cannot infer the cold
+nuclear matter effect on $J/\psi$ production in $AA$ collisions from that in
+$dA$. We present the calculation of $J/\psi$ multiplicity in the framework of
+the CGC (color glass condensate)/saturation and show that it agrees with the
+experimental data.",1012.4212v1
+2010-12-23,Near-field radiative heat transfer and van der Waals friction between closely spaced graphene and amorphous SiO$_2$,"We study the radiative heat transfer and the van der Waals friction between
+graphene and an amorphous SiO$_2$ substrate. We study the surface
+phonon-polaritons contribution to the low-field mobility as a function of
+temperature and of carrier density. We find that the electric current saturate
+at a high electric field, in agreement with experiment. The saturation current
+depends weakly on the temperature, which we attribute to the ""quantum"" friction
+between the graphene carriers and the substrate optical phonons. We calculate
+the frictional drag between two graphene sheets caused by van der Waals
+friction, and find that this drag can induce a high enough voltage which can be
+easily measured experimentally. We find that for nonsuspended graphene the
+near-field radiative heat transfer, and the heat transfer due to direct
+phononic coupling, are of the same order of magnitude at low electric field.
+The phononic contribution to the heat transfer dominates at high field. For
+large separation between graphene and the substrate the heat transfer is
+dominated by the near-field radiative heat transfer.",1012.5212v1
+2011-01-11,Diffractive hadron production in DIS off heavy nuclei and gluon saturation,"We calculate the cross section for diffractive hadron production in deep
+inelastic scattering off heavy nuclei in the framework of gluon
+saturation/color glass condensate. We analyze the kinematic region of the
+future Electron-Ion Collider. We argue that coherent and incoherent diffractive
+channels are very sensitive to the structure of the nuclear matter at low $x$.
+This expresses itself in a characteristic dependence of the cross sections on
+rapidity and transverse momentum of the produced hadron and on the nuclear
+weight. We also discuss dependence on the scattering angle and argue that both
+coherent and incoherent cross sections may be within experimental reach at EIC.",1101.2179v2
+2011-01-19,Constraints on the density dependence of the symmetry energy from heavy ion collisions,"Constraints on the Equation of State for symmetric matter (equal neutron and
+proton numbers) have been extracted from energetic collisions of heavy ions
+over a range of energies. Collisions of neutron-deficient and neutron-rich
+heavy ions now provide initial constraints on the EoS of neutron-rich matter at
+sub-saturation densities from isospin diffusions and neutron proton ratios.
+This article reviews the experimental constraints on the density dependence of
+Symmetry Energy at sub-saturation density.",1101.3648v1
+2011-01-21,Improvement of the crossed undulator design for effective circular polarization control in X-ray FELs,"The production of X-ray radiation with a high degree of circular polarization
+constitutes an important goal at XFEL facilities. A simple scheme to obtain
+circular polarization control with crossed undulators has been proposed so far.
+In its simplest configuration the crossed undulators consist of pair of short
+planar undulators in crossed position separated by an electromagnetic phase
+shifter. An advantage of this configuration is a fast helicity switching. A
+drawback is that a high degree of circular polarization (over 90%) can only be
+achieved for lengths of the insertion devices significantly shorter than the
+gain length, i.e. at output power significantly lower than the saturation power
+level. The obvious and technically possible extension considered in this paper,
+is to use a setup with two or more crossed undulators separated by phase
+shifters. This cascade crossed undulator scheme is distinguished, in
+performance, by a fast helicity switching, a high degree of circular
+polarization (over 95%) and a high output power level, comparable with the
+saturation power level in the baseline undulator at fundamental wavelength. We
+present feasibility study and exemplifications for the LCLS baseline in the
+soft X-ray regime.",1101.4085v1
+2011-02-01,A congestion model for cell migration,"This paper deals with a class of macroscopic models for cell migration in a
+saturated medium for two-species mixtures. Those species tend to achieve some
+motion according to a desired velocity, and congestion forces them to adapt
+their velocity. This adaptation is modelled by a correction velocity which is
+chosen minimal in a least-square sense. We are especially interested in two
+situations: a single active species moves in a passive matrix (cell migration)
+with a given desired velocity, and a closed-loop Keller-Segel type model, where
+the desired velocity is the gradient of a self-emitted chemoattractant. We
+propose a theoretical framework for the open-loop model (desired velocities are
+defined as gradients of given functions) based on a formulation in the form of
+a gradient flow in the Wasserstein space. We propose a numerical strategy to
+discretize the model, and illustrate its behaviour in the case of a prescribed
+velocity, and for the saturated Keller-Segel model.",1102.0147v1
+2011-02-02,Threshold Saturation on Channels with Memory via Spatial Coupling,"We consider spatially coupled code ensembles. A particular instance are
+convolutional LDPC ensembles. It was recently shown that, for transmission over
+the memoryless binary erasure channel, this coupling increases the belief
+propagation threshold of the ensemble to the maximum a-posteriori threshold of
+the underlying component ensemble. This paved the way for a new class of
+capacity achieving low-density parity check codes. It was also shown
+empirically that the same threshold saturation occurs when we consider
+transmission over general binary input memoryless channels.
+  In this work, we report on empirical evidence which suggests that the same
+phenomenon also occurs when transmission takes place over a class of channels
+with memory. This is confirmed both by simulations as well as by computing EXIT
+curves.",1102.0406v1
+2011-02-04,Two-particle azimuthal correlations at forward rapidity in STAR,"During the 2008 run the Relativistic Heavy Ion Collider (RHIC) at the
+Brookhaven Nation Laboratiory (BNL), NY, provided high luminosity in both p+p
+and d+Au collisions at $\sqrt{s_{NN}}=200\mathrm{\,GeV}$. Electromagnetic
+calorimeter acceptance in STAR was enhanced by the new Forward Meson
+Spectrometer (FMS), and is now almost contiguous from $-1<\eta\4$ over the full
+azimuth. This allows measurements of the azimuthal correlation between a
+forward neutral pion and a second particle in a very large rapidity range.
+Di-hadron azimuthal correlations provide sensitivity to the low longitudinal
+momentum fraction ($x$) component of the gluon density in the nuclear target.
+Initial state nonlinear effects are in fact expected to appear in d+Au
+collisions when the dense part of the nucleus is probed. The analysis in this
+thesis shows that such correlations and their dependence on rapidity,
+transverse momentum and collision centrality are qualitative consistent with
+the existence of gluon saturation effects in the relativistic nucleus.
+Theoretical expectations for azimuthal correlations between a dilute system
+(deuteron) and a saturated target (Gold nucleus) have been explored.",1102.0931v1
+2011-02-15,Saturation of front propagation in a reaction-diffusion process describing plasma damage in porous low-k materials,"We propose a three-component reaction-diffusion system yielding an asymptotic
+logarithmic time-dependence for a moving interface. This is naturally related
+to a Stefan-problem for which both one-sided Dirichlet-type and von
+Neumann-type boundary conditions are considered. We integrate the dependence of
+the interface motion on diffusion and reaction parameters and we observe a
+change from transport behavior and interface motion \sim t^1/2 to logarithmic
+behavior \sim ln t as a function of time. We apply our theoretical findings to
+the propagation of carbon depletion in porous dielectrics exposed to a low
+temperature plasma. This diffusion saturation is reached after about 1 minute
+in typical experimental situations of plasma damage in microelectronic
+fabrication. We predict the general dependencies on porosity and reaction
+rates.",1102.3084v2
+2011-02-16,Parallel Complexity of Random Boolean Circuits,"Random instances of feedforward Boolean circuits are studied both
+analytically and numerically. Evaluating these circuits is known to be a
+P-complete problem and thus, in the worst case, believed to be impossible to
+perform, even given a massively parallel computer, in time much less than the
+depth of the circuit. Nonetheless, it is found that for some ensembles of
+random circuits, saturation to a fixed truth value occurs rapidly so that
+evaluation of the circuit can be accomplished in much less parallel time than
+the depth of the circuit. For other ensembles saturation does not occur and
+circuit evaluation is apparently hard. In particular, for some random circuits
+composed of connectives with five or more inputs, the number of true outputs at
+each level is a chaotic sequence. Finally, while the average case complexity
+depends on the choice of ensemble, it is shown that for all ensembles it is
+possible to simultaneously construct a typical circuit together with its
+solution in polylogarithmic parallel time.",1102.3310v2
+2011-02-16,Quantum phenomena in the radial thermal expansion of bundles of single-walled carbon nanotubes doped with 3He. A giant isotope effect,"The radial thermal expansion {\alpha}r of bundles of single-walled carbon
+nanotubes saturated with 3He up to the molar concentration 9.4% has been
+investigated in the temperature interval 2.1-9.5 K by high-sensitivity
+capacitance dilatometry. In the interval 2.1-7 K a negative {\alpha}r was
+observed, with a magnitude which exceeded the largest negative {\alpha}r values
+of pure and 4He-saturated nanotubes by three and two orders of magnitude,
+respectively. The contributions of the two He isotope impurities to the
+negative thermal expansion of the nanotube bundles are most likely connected
+with the spatial redistribution of 4He and 3He atoms by tunneling at the
+surface and inside nanotube bundles. The isotope effect turned out to be huge,
+probably owing to the higher tunneling probability of 3He atoms.",1102.3334v1
+2011-02-26,The thermodynamic approach to multifractal analysis,"Most results in multifractal analysis are obtained using either a
+thermodynamic approach based on existence and uniqueness of equilibrium states
+or a saturation approach based on some version of the specification property. A
+general framework incorporating the most important multifractal spectra was
+introduced by Barreira and Saussol, who used the thermodynamic approach to
+establish the multifractal formalism in the uniformly hyperbolic setting,
+unifying many existing results. We extend this framework to apply to a broad
+class of non-uniformly hyperbolic systems, including examples with phase
+transitions. In the process, we compare this thermodynamic approach with the
+saturation approach and give a survey of many of the multifractal results in
+the literature.",1102.5427v2
+2011-03-15,Liquid-Droplet as a model for the rotation curve problem,"The dynamics of large scale gravitational structures like galaxies, local
+groups and clusters is studied based on the so-called {\it Liquid-Droplet}
+model describing the saturation property of the nuclear force. Using the
+assumption that the gravitational force is also saturated over large scale
+structures, it is argued that the Newtonian gravitational potential may be
+replaced by an effective {\it Machian} gravitational potential. Application of
+this new potential at these large scale structures may give the rotation curves
+in good agreement with observations. Then, the virial theorem for this kind of
+gravitational interaction is developed and also the Tully-Fisher relation is
+obtained. A physical explanation is given for the so-called {\it constant}
+acceleration in the MOND as the {\it effective} gravitational strength of these
+structures. Finally, a brief argument is given for comparison with dark matter
+models.",1103.3057v3
+2011-03-18,Weak turbulence theory of the non-linear evolution of the ion ring distribution,"The nonlinear evolution of an ion ring instability in a low-beta
+magnetospheric plasma is considered. The evolution of the two-dimensional ring
+distribution is essentially quasilinear. Ignoring nonlinear processes the
+time-scale for the quasilinear evolution is the same as for the linear
+instability 1/t_ql gamma_l. However, when nonlinear processes become important,
+a new time scale becomes relevant to the wave saturation mechanism. Induced
+nonlinear scattering of the lower-hybrid waves by plasma electrons is the
+dominant nonlinearity relevant for plasmas in the inner magnetosphere and
+typically occurs on the timescale 1/t_ql w(M/m)W/nT, where W is the wave energy
+density, nT is the thermal energy density of the background plasma, and M/m is
+the ion to electron mass ratio, which has the consequence that the wave
+amplitude saturates at a low level, and the timescale for quasilinear
+relaxation is extended by orders of magnitude.",1103.3715v1
+2011-03-23,Imprints of Nuclear Symmetry Energy on Properties of Neutron Stars,"Significant progress has been made in recent years in constraining the
+density dependence of nuclear symmetry energy using terrestrial nuclear
+laboratory data. Around and below the nuclear matter saturation density, the
+experimental constraints start to merge in a relatively narrow region. At
+supra-saturation densities, there are, however, still large uncertainties.
+After summarizing the latest experimental constraints on the density dependence
+of nuclear symmetry energy, we highlight a few recent studies examining
+imprints of nuclear symmetry energy on the binding energy, energy release
+during hadron-quark phase transitions as well as the $w$-mode frequency and
+damping time of gravitational wave emission of neutron stars.",1103.4652v1
+2011-03-29,Accumulation of beneficial mutations in one dimension,"When beneficial mutations are relatively common, competition between multiple
+unfixed mutations can reduce the rate of fixation in well-mixed asexual
+populations. We introduce a one dimensional model with a steady accumulation of
+beneficial mutations. We find a transition between periodic selection and
+multiple-mutation regimes. In the multiple-mutation regime, the increase of
+fitness along the lattice bears a striking similarity to surface growth
+phenomena, with power law growth and saturation of the interface width. We also
+find significant differences compared to the well-mixed model. In our lattice
+model, the transition between regimes happens at a much lower mutation rate due
+to slower fixation times in one dimension. Also the rate of fixation is reduced
+with increasing mutation rate due to the more intense competition, and it
+saturates with large population size.",1103.5685v2
+2011-04-01,Finite Pressure Corrections to Nucleon Structure Function Inside a Nuclear Medium,"Our model calculations performed in the frame of the Relativistic Mean Field
+(RMF) approach show how important are the modifications of nucleon Structure
+Function (SF) in Nuclear Matter (NM) above the saturation point. They
+originated from the conservation of a parton longitudinal momenta - essential
+in the explanation of the EMC effect at the saturation point of NM. For higher
+density the finite pressure corrections emerge from the Hugenholtz -van Hove
+(HH) theorem valid for NM and asks to modify the nucleon SF. The density
+evolution of the nuclear SF seems to be stronger for higher densities. Here we
+show that the course of Equation o State (EoS) in our modified Walecka model is
+very close to that obtained from extensive DBHF calculations with a Bonn A
+potential. The nuclear compressibility decreases. Our model - a nonlinear
+extension of nuclear RMF, has no additional parameters.",1104.0093v4
+2011-04-06,Quantum entanglement in SU(3) lattice Yang-Mills theory at zero and finite temperatures,"We examine the entanglement properties of the Yang-Mills theory by
+calculating $\alpha$ entanglement entropy with $\alpha=2$ using a SU(3)
+quenched lattice gauge simulation both in the confinement and the deconfinement
+phases. In the confinement phase, the derivative of the $\alpha$ entropy with
+respect to the size $l$ of the subregion, whose entanglement properties are
+interested in, scales as $1/l^3$, and a clear discontinuity cannot be found
+within our statistical errors. The $\alpha$ entropy in the deconfinement phase
+saturates at large $l$. The saturation value is comparable with the thermal
+entropy of the pure Yang-Mills theory, indicating that the $\alpha$ entropy
+obeys the volume law at large $l$ in the deconfinement phase.",1104.1011v1
+2011-05-03,The advection-condensation model and water vapour PDFs,"The statistically steady humidity distribution resulting from an interaction
+of advection, modeled as an uncorrelated random walk of moist parcels on an
+isentropic surface, and a vapour sink, modeled as immediate condensation
+whenever the specific humidity exceeds a specified saturation humidity, is
+explored with theory and simulation. A source supplies moisture at the
+deep-tropical southern boundary of the domain, and the saturation humidity is
+specified as a monotonically decreasing function of distance from the boundary.
+The boundary source balances the interior condensation sink, so that a
+stationary spatially inhomogeneous humidity distribution emerges. An exact
+solution of the Fokker-Planck equation delivers a simple expression for the
+resulting probability density function (PDF) of the water vapour field and also
+of the relative humidity. This solution agrees completely with a numerical
+simulation of the process, and the humidity PDF exhibits several features of
+interest, such as bimodality close to the source and unimodality further from
+the source. The PDFs of specific and relative humidity are broad and
+non-Gaussian. The domain averaged relative humidity PDF is bimodal with
+distinct moist and dry peaks, a feature which we show agrees with middleworld
+isentropic PDFs derived from the ERA interim dataset.",1105.0470v1
+2011-05-17,The Ridge from the BFKL evolution and beyond,"We show that the long-range rapidity correlations between the produced
+charged-hadron pairs from two BFKL parton showers generate considerable
+azimuthal angle correlations. These correlations have no 1/N_c suppression. The
+effect of gluon saturation on these correlations are discussed and we show that
+it is important. We show that a pronounced ridge-like structure emerges by
+going from the BFKL to the saturation region. We show that the ridge structure
+at high-energy proton-proton and nucleus-nucleus collisions has the same origin
+and its main feature can be understood due to initial-state effects. Although
+the effects of final-state interactions in the latter case can be
+non-negligible.",1105.3275v2
+2011-05-17,Jaynes Cummings treatment of superconducting resonators with dielectric loss due to two-level systems,"We perform a quantum mechanical analysis of superconducting resonators
+subject to dielectric loss arising from charged two-level systems. We present
+numerical and analytical descriptions of the dynamics of energy decay from the
+resonator within the Jaynes-Cummings model. Our analysis allows us to
+distinguish the strong and weak coupling regimes of the model and to describe
+within each regime cases where the two-level system is unsaturated or
+saturated. We find that the quantum theory agrees with the classical model for
+weak coupling. However, for strong coupling the quantum theory predicts lower
+loss than the classical theory in the unsaturated regime. Also, in contrast to
+the classical theory, the photon number at which saturation occurs in the
+strong coupling quantum theory is independent of the coupling between the
+resonator and the two-level system.",1105.3446v1
+2011-05-26,Calibration and performance of the photon-counting detectors for the Ultraviolet Imaging Telescopes (UVIT) of the Astrosat observatory,"We describe calibration data, and discuss performance of the photon-counting
+flight detectors for the Ultraviolet Imaging Telescopes on the Astrosat
+observatory. The paper describes dark current, flat field and light-spot images
+for FUV, NUV, and Visible band detectors at more than one wavelength setting
+for each. We also report on nominal gain and low-gain operations, full- and
+sub-window read rates, and non-photon-counting modes of operation, all expected
+to be used in flight. We derive corrections to the event centroids from the
+CMOS readout arrays, for different centroid algorithms. We derive spatial
+resolution values for each detector and plots of point-source signal saturation
+for different flux levels. We also discuss ways to correct for saturation in
+extended object images.",1105.5361v1
+2011-05-31,Universality for the Noisy Slepian-Wolf Problem Via Spatial Coupling,"We consider a noisy Slepian-Wolf problem where two correlated sources are
+separately encoded and transmitted over two independent binary memoryless
+symmetric channels. Each channel capacity is assumed to be characterized by a
+single parameter which is not known at the transmitter. The receiver has
+knowledge of both the source correlation and the channel parameters. We call a
+system universal if it retains near-capacity performance without channel
+knowledge at the transmitter. Kudekar et al. recently showed that terminated
+low-density parity-check (LDPC) convolutional codes (a.k.a. spatially-coupled
+LDPC ensembles) can have belief-propagation thresholds that approach their
+maximum a-posteriori thresholds. This was proven for binary erasure channels
+and shown empirically for binary memoryless symmetric channels. They also
+conjectured that the principle of spatial coupling is very general and the
+phenomenon of threshold saturation applies to a very broad class of graphical
+models. In this work, we derive an area theorem for the joint decoder and
+empirically show that threshold saturation occurs for this problem. As a
+result, we demonstrate near-universal performance for this problem using the
+proposed spatially-coupled coding system. A similar result is also discussed
+briefly for the 2-user multiple-access channel.",1105.6374v1
+2011-08-01,BPS Saturated String Amplitudes: K3 Elliptic Genus and Igusa Cusp Form,"We study BPS saturated one-loop amplitudes in type II string theory
+compactified on K3 x T^2. The classes of amplitudes we consider are only
+sensitive to the very basic topological data of the internal K3 manifold. As a
+consequence, the integrands of the former are related to the elliptic genus of
+K3, which can be decomposed into representations of the internal N=4
+superconformal algebra. Depending on the precise choice of external states
+these amplitudes capture either only the contribution of the short multiplets
+or the full series including intermediate multiplets. In the latter case we can
+define a generating functional for the whole class, which we show is given by
+the weight ten Igusa cusp form chi_{10} of Sp(4,Z). We speculate on possible
+algebraic implications of our result on the BPS states of the N=4 type II
+compactification.",1108.0323v2
+2011-08-02,Composition and stability of hybrid stars with hyperons and quark color-superconductivity,"The recent measurement of a $1.97\pm 0.04$ solar-mass pulsar places a
+stringent lower bound on the maximum mass of compact stars and therefore
+challenges the existence of any agents that soften the equation of state of
+ultra-dense matter. We investigate whether hyperons and/or quark matter can be
+accommodated in massive compact stars by constructing an equation of state
+based on a combination of phenomenological relativistic hyper-nuclear density
+functional and an effective model of quantum chromodynamics (the
+Nambu-Jona-Lasinio model). Stable configurations are obtained with $M \ge 1.97
+M_{\sun}$ featuring hyper-nuclear and quark matter in color superconducting
+state if the equation of state of nuclear matter is stiff above the saturation
+density, the transition to quark matter takes place at a few times the nuclear
+saturation density, and the repulsive vector interactions in quark matter are
+substantial.",1108.0559v2
+2011-08-08,On the small-x evolution of the color quadrupole and the Weizsäcker-Williams gluon distribution,"Color quadrupoles have been found to be important in the proper description
+of observables sensitive to the small-x regime in nuclei as well as in the
+operator definition of the Weizs\""acker-Williams gluon distribution. In this
+paper, we derive the small-x evolution equation of the quadrupole and the
+Weizs\""acker-Williams gluon distribution without taking large N_c limit and
+study the properties of the equation in both dilute and saturation regime. We
+find that the quadrupole evolution follows the BFKL evolution in the dilute
+regime and then saturates in the dense region due to nonlinear terms. This
+leads us to conclude that the Weizs\""acker-Williams gluon distribution should
+obey the same geometrical behavior as the dipole gluon distribution as found in
+the inclusive DIS measurement.",1108.1752v2
+2011-08-16,Heralded Single-Photon Emission from the Mollow Triplet Sidebands of a Quantum Dot,"Emission from a resonantly excited quantum emitter is a fascinating research
+topic within quantum optics and a useful source for different types of quantum
+light fields. The resonance spectrum consists of a single spectral line below
+saturation of a quantum emitter which develops into a triplet at powers above
+saturation of the emitter. The spectral properties of the triplet strongly
+depends on pump power and detuning of the excitation laser. The three closely
+spaced photon channels from the resonance fluorescence have different photon
+statistical signatures. We present a detailed photon-statistics analysis of the
+resonance fluorescence emission triplet from a solid state-based artificial
+atom, i.e. a semiconductor quantum dot. The photon correlation measurements
+demonstrate both 'single' and 'heralded' photon emission from the Mollow
+triplet sidebands. The ultra-bright and narrowband emission (5.9 MHz into the
+first lens) can be conveniently frequency-tuned by laser detuning over 15 times
+its linewidth ({\Delta \nu} \approx 1.0 GHz). These unique properties make the
+Mollow triplet sideband emission a valuable light source for, e.g.quantum light
+spectroscopy and quantum information applications.",1108.3225v1
+2011-08-29,Rayleigh-Benard convection with phase changes in a Galerkin model,"The transition to turbulence in Rayleigh-Benard convection with phase changes
+and the resulting convective patterns are studied in a three-dimensional
+Galerkin model. Our study is focused to the conditionally unstable regime of
+moist convection in which the stratification is stable for unsaturated air
+parcels and unstable for saturated parcels. We perform a comprehensive
+statistical analysis of the transition to convection that samples the
+dependence of attractors (or fixed points) in the phase space of the model on
+the dimensionless parameters. Conditionally unstable convection can be
+initiated either from a fully unsaturated linearly stable equilibrium or a
+fully saturated linearly unstable equilibrium. Highly localized moist
+convection can be found in steady state, in oscillating recharge-discharge
+regime or turbulent in dependence on the aspect ratio and the degree of stable
+stratification of the unsaturated air. Our phase space analysis predicts
+parameter ranges for which self-sustained convective regimes in the case of
+subcritical conditional instability can be observed. The observed regime
+transitions for moist convection bear some similarities to transitions to
+turbulence in simple shear flows.",1108.5611v1
+2011-08-31,Blending margins: The modal logic K has nullary unification type,"We investigate properties of the formula $p \to \Box p$ in the basic modal
+logic K. We show that K satisfies an infinitary weaker variant of the rule of
+margins $\phi \to \Box\phi / \phi, \neg\phi$, and as a consequence, we obtain
+various negative results about admissibility and unification in K. We describe
+a complete set of unifiers (i.e., substitutions making the formula provable) of
+$p \to \Box p$, and use it to establish that K has the worst possible
+unification type: nullary. In well-behaved transitive modal logics,
+admissibility and unification can be analyzed in terms of projective formulas,
+introduced by Ghilardi; in particular, projective formulas coincide for these
+logics with formulas that are admissibly saturated (i.e., derive all their
+multiple-conclusion admissible consequences) or exact (i.e., axiomatize a
+theory of a substitution). In contrast, we show that in K, the formula $p \to
+\Box p$ is admissibly saturated, but neither projective nor exact. All our
+results for K also apply to the basic description logic ALC.",1108.6240v2
+2011-09-02,On Angular Correlations and High Energy Evolution,"We address the question to what extent JIMWLK evolution is capable of taking
+into account angular correlations in a high energy hadronic wave function. Our
+conclusion is that angular (and indeed other) correlations in the wave function
+cannot be reliably calculated without taking into account Pomeron loops in the
+evolution. As an example we study numerically the energy evolution of angular
+correlations between dipole scattering amplitudes in the framework of the large
+$N_c$ approximation to JIMWLK evolution (the ""`projectile dipole model""').
+Target correlations are introduced via averaging over (isotropic) ensemble of
+anisotropic initial conditions. We find that correlations disappear very
+quickly with rapidity even inside the saturation radius. This is in accordance
+with our physical picture of JIMWLK evolution. The actual correlations inside
+the saturation radius in the target QCD wave function, on the other hand should
+remain sizable at any rapidity.",1109.0347v1
+2011-09-03,Small-${\it x}$ and Forward Measurements at STAR,"Measurements of azimuthal differences between forward di-pions are sensitive
+to the low-${\it x}$ gluon content of the proton and provide the best
+opportunity to probe for gluon saturation in nuclei. Previously reported
+analyses have shown that the gluon saturation regime may have been reached at
+STAR by looking at forward di-pions in d+Au collisions. Further insight into
+the uncorrelated pedestal below the near-side and away-side peaks in azimuthal
+correlations may be provided by differentiating between d+Au and p+Au
+collisions, by tagging on intact neutrons in the deuteron beam in d+Au
+collisions. Comparisons to recent theories indicate that multi-parton
+interactions play a more significant role in d+Au collisions than p+Au
+collisions and offer a unique opportunity to study correlations between leading
+partons inside nucleons. The general features found for the peaks in forward
+di-pion azimuthal correlations in d+Au collisions are also present in p+Au
+collisions.",1109.0649v1
+2011-09-06,Electron Transport Properties of Bilayer Graphene,"Electron transport in bilayer graphene is studied by using a first principles
+analysis and theMonte Carlo simulation under conditions relevant to potential
+applications. While the intrinsic properties are found to be much less
+desirable in bilayer than in monolayer graphene, with significantly reduced
+mobilities and saturation velocities, the calculation also reveals the dominant
+influence of extrinsic factors such as the substrate and impurities.
+Accordingly, the difference between two graphene forms are more muted in
+realistic settings although the velocity-field characteristics remain
+substantially lower in the bilayer. When bilayer graphene is subject to an
+interlayer bias, the resulting changes in the energy dispersion lead to
+stronger electron scattering at the bottom of the conduction band. The mobility
+decreases significantly with the size of the generated bandgap, whereas the
+saturation velocity remains largely unaffected.",1109.1035v1
+2011-09-06,Gluon saturation effects on the color singlet J/Psi production in high energy dA and AA collisions,"We derive the formulae for the cross section of J/Psi production in high
+energy pA and AA collisions taking into account the gluon saturation/color
+glass condensate effects. We then perform the numerical calculations of the
+corresponding nuclear modification factors and find a good agreement between
+our calculations and the experimental data on J/Psi production in dA
+collisions. We also observe that cold nuclear modification effects alone cannot
+describe the data on J/Psi production in AA collisions. Additional final state
+suppression (at RHIC) and enhancement (at LHC) mechanisms are required to
+explain the experimental observations.",1109.1250v1
+2011-09-16,Neon Insights from Old Solar X-rays: a Plasma Temperature Dependence of the Coronal Neon Content,"An analysis using modern atomic data of fluxes culled from the literature for
+O VIII and Ne IX lines observed in solar active regions by the P78 and Solar
+Maximum Mission satellites confirms that the coronal Ne/O abundance ratio
+varies by a factor of two or more, and finds an increase in Ne/O with
+increasing active region plasma temperature. The latter is reminiscent of
+evidence for increasing Ne/O with stellar activity in low-activity coronae that
+reaches a ""neon saturation"" in moderately active stars at approximately twice
+the historically accepted solar value of about 0.15 by number. We argue that
+neon saturation represents the underlying stellar photospheric compositions,
+and that low activity coronae, including that of the Sun, are generally
+depleted in neon. The implication would be that the solar Ne/O abundance ratio
+should be revised upward by a factor of about two to n(Ne)/n(O)~0.3. Diverse
+observations of neon in the local cosmos provide some support for such a
+revision. Neon would still be of some relevance for reconciling helioseismology
+with solar models computed using recently advocated chemical mixtures with
+lower metal content.",1109.3661v1
+2011-09-20,Molecular explanation for why talc surfaces can be both hydrophilic and hydrophobic,"While individual water molecules adsorb strongly on a talc surface
+(hydrophilic behavior), a droplet of water beads up on the same surface
+(hydrophobic behavior). To rationalize this dichotomy, we investigate the
+influence of the microscopic structure of the surface and the strength of
+adhesive (surface-water) interactions on surface hydrophobicity. We show that
+at low relative humidity, the competition between adhesion and the favorable
+entropy of being in the vapor phase determines the surface coverage. However,
+at saturation, it is the competition between adhesion and cohesion (water-water
+interactions) that determines surface hydrophobicity. The adhesive interactions
+in talc are strong enough to overcome the unfavorable entropy, and water
+adsorbs strongly on talc surfaces. However, they are too weak to overcome the
+cohesive interactions, and water thus beads up on talc surfaces. Surprisingly,
+even (talc-like) surfaces that are highly adhesive, do not fully wet at
+saturation. Instead, a water droplet forms on top of a strongly adsorbed
+monolayer of water. Our results imply that the interior of hydrophobic zeolites
+suspended in water may contain adsorbed water molecules at pressures much
+smaller than the intrusion pressure.",1109.4284v1
+2011-09-30,Quasi-compactons in inverted nonlinear photonic crystals,"We study large-amplitude one-dimensional solitary waves in photonic crystals
+featuring competition between linear and nonlinear lattices, with minima of the
+linear potential coinciding with maxima of the nonlinear pseudopotential, and
+vice versa (inverted nonlinear photonic crystals, INPhCs), in the case of the
+saturable self-focusing nonlinearity. Such crystals were recently fabricated
+using a mixture of SU-8 and Rhodamine-B optical materials. By means of
+numerical methods and analytical approximations, we find that large-amplitude
+solitons are broad sharply localized stable pulses (quasi-compactons, QCs).
+With the increase of the totalpower, P, the QC's centroid performs multiple
+switchings between minima and maxima of the linear potential. Unlike cubic
+INPhCs, the large-amplitude solitons are mobile in the medium with the
+saturable nonlinearity. The threshold value of the kick necessary to set the
+soliton in motion is found as a function of P. Collisions between moving QCs
+are considered too.",1110.0049v1
+2011-10-03,Universal Codes for the Gaussian MAC via Spatial Coupling,"We consider transmission of two independent and separately encoded sources
+over a two-user binary-input Gaussian multiple-access channel. The channel
+gains are assumed to be unknown at the transmitter and the goal is to design an
+encoder-decoder pair that achieves reliable communication for all channel gains
+where this is theoretically possible. We call such a system \emph{universal}
+with respect to the channel gains.
+  Kudekar et al. recently showed that terminated low-density parity-check
+convolutional codes (a.k.a. spatially-coupled low-density parity-check
+ensembles) have belief-propagation thresholds that approach their maximum
+a-posteriori thresholds. This was proven for binary erasure channels and shown
+empirically for binary memoryless symmetric channels. It was conjectured that
+the principle of spatial coupling is very general and the phenomenon of
+threshold saturation applies to a very broad class of graphical models. In this
+work, we derive an area theorem for the joint decoder and empirically show that
+threshold saturation occurs for this problem. As a result, we demonstrate
+near-universal performance for this problem using the proposed
+spatially-coupled coding system.",1110.0252v1
+2011-10-14,Optimization of the baseline and the parent muon energy for a low energy neutrino factory,"We discuss the optimal setup for a low energy neutrino factory in order to
+achieve a 5\sigma-discovery of a nonzero mixing angle \theta_{13}, a nonzero CP
+phase \delta_{CP}, and the mass hierarchy. We explore parent muon energies in
+the range 5--16 GeV, and baselines in the range 500--5000 km. We present the
+results in terms of the reach in sin^2\theta_{13}, emphasizing the dependence
+of the optimal baseline on the true value of \delta_{CP}. We show that the
+sensitivity of a given setup typically increases with parent muon energy,
+reaching saturation for higher energies. The saturation energy is larger for
+longer baselines; we present an estimate of this dependence. In the light of
+the recent indications of a large \theta_{13}, we also determine how these
+preferences would change if indeed a large \theta_{13} is confirmed. In such a
+case, the baselines ~2500 km (~1500 km) may be expected to lead to hierarchy
+determination (\delta_{CP} discovery) with the minimum exposure.",1110.3289v2
+2011-10-19,Evaluating the robustness of top coatings comprising plasma-deposited fluorocarbons in electrowetting systems,"Thin dielectric stacks comprising a main insulating layer and a hydrophobic
+top coating are commonly used in low voltage electrowetting systems. However,
+in most cases, thin dielectrics fail to endure persistent electrowetting
+testing at high voltages, namely beyond the saturation onset, as electrolysis
+indicates dielectric failure. Careful sample inspection via optical microscopy
+revealed possible local delamination of the top coating under high electric
+fields. Thus, improvement of the adhesion strength of the hydrophobic top
+coating to the main dielectric is attempted through a plasma-deposited
+fluorocarbon interlayer. Interestingly enough the proposed dielectric stack
+exhibited a) resistance to dielectric breakdown, b) higher contact angle
+modulation range, and c) electrowetting cycle reversibility. Appearance of
+electrolysis in the saturation regime is inhibited, suggesting the use of this
+hydrophobic dielectric stack for the design of more efficient electrowetting
+systems. The possible causes of the improved performance are investigated by
+nanoscratch characterization.",1110.4238v1
+2011-10-25,Allen-Cahn and Cahn-Hilliard-like equations for dissipative dynamics of saturated porous media,"We consider a saturated porous medium in the regime of solid-fluid
+segregation under an applied pressure on the solid constituent. We prove that,
+depending on the dissipation mechanism, the dynamics is described either by a
+Cahn-Hilliard or by an Allen-Cahn-like equation. More precisely, when the
+dissipation is modeled via the Darcy law we find that, for small deformation of
+the solid and small variations of the fluid density, the evolution equation is
+very similar to the Cahn-Hilliard equation. On the other hand, when only the
+Stokes dissipation term is considered, we find that the evolution is governed
+by an Allen-Cahn-like equation. We use this theory to describe the formation of
+interfaces inside porous media. We consider a recently developed model proposed
+to study the solid-liquid segregation in consolidation and we are able to fully
+describe the formation of an interface between the fluid-rich and the
+fluid-poor phase.",1110.5457v2
+2011-10-29,Comparative investigation of third and fifth harmonic generation in atomic and molecular gases driven by mid-infrared ultrafast laser pulses,"We report on the comparative experimental investigation on third and fifth
+harmonic generation (THG and FHG) in atomic and molecular gases driven by
+mid-infrared ultrafast laser pulses at a wavelength of ~1500 nm. We observe
+that the conversion efficiencies of both the THG and FHG processes saturate at
+similar peak intensities close to ~1.5\times1014 W/cm2 for argon, nitrogen, and
+air, whose ionization potentials are close to each other. Near the saturation
+intensity, the ratio of yields of the FHG and THG reaches ~10-1 for all the
+gases. Our results show that high-order Kerr effects do exist, whereas they are
+insufficient to balance the Kerr self-focusing without the assistance of plasma
+generation.",1110.6505v1
+2011-10-30,Gluon-decay cascade in AA collisions at the LHC and saturation,"We extract the energy-dependence of the gluon-jet decay cascade from e^+e^-
+annihilation data and show that this energy-dependence has power-low behavior
+for the average transverse momentum of jet bigger than 1 GeV. We show that the
+observed different power-law energy-dependence of hadron multiplicity in AA
+compared to pp collisions at the LHC is due to the enhanced gluon-decay effect
+before hadronization. This effect is more important for AA collisions where the
+saturation scale is larger than 1 GeV. Here we confront our published
+predictions in arXiv:1102.2385 for the rapidity distribution of the charged
+hadron production with the recently released data from the CMS collaboration in
+AA collisions and show that our predictions is in perfect agreement with the
+data.",1110.6642v1
+2011-11-09,Charged particle multiplicities in pA interactions at the LHC from the Color Glass Condensate,"The forthcoming LHC measurement of hadron multiplicity in proton-nucleus
+collisions is a crucial test of the k_t factorization and gluon saturation
+based models. Here, we provide quantitative predictions for the pseudorapidity
+distribution of charged particles produced in minimum bias proton-nucleus
+collisions at the LHC based on the idea of gluon saturation in the color-glass
+condensate framework. Our formulation gives good descriptions of the LHC and
+RHIC data for the charged-hadron multiplicities in both proton-proton and
+nucleus-nucleus collisions, and also the deep inelastic scattering at HERA at
+small Bjorken-x.",1111.2312v2
+2011-11-12,An effective-charge model for the trapping of impurities of fluids in channels with nanostructured walls,"We present model equations for the trapping and accumulation of particles in
+a short cylindrical channel with nanostructured inner walls when a fluid passes
+through, carrying a moderate load of impurities. The basic ingredient of the
+model is the introduction of a phenomenological ""effective-charge density"" of
+the walls, related to the electrical charges exposed in the nanotexture, and
+which is gradually reduced as the flow runs through the channel and the trapped
+impurities cover the internal walls. By solving the proposed equations, three
+regimes are predicted for the channel: a linear or clean-filter regime, a
+logarithmic or half-saturation regime, and the saturation limit. It is proposed
+that experimentally testing these regimes may help to understand the enhanced
+trapping capability observed in many diverse nanotextured channel structures.",1111.2920v3
+2011-11-13,Gluon saturation in $pA$ collisions at the LHC: KLN model predictions for hadron multiplicities,"The upcoming p+Pb run at the LHC will probe the nuclear gluon distribution at
+very small Bjorken x (from $x \sim 10^{-4}$ at mid-rapidity down to $x \sim
+10^{-6}$ in the proton fragmentation region) and will allow to test approaches
+based on parton saturation. Here, we present the predictions of the KLN model
+for hadron multiplicities and multiplicity distributions in p+Pb collisions at
+a center-of-mass energy of 4.4 TeV. We also compare the model to the existing
+pp, dA and AA data from RHIC and LHC.",1111.3031v2
+2011-11-14,Information storage capacity of discrete spin systems,"Understanding the limits imposed on information storage capacity of physical
+systems is a problem of fundamental and practical importance which bridges
+physics and information science. There is a well-known upper bound on the
+amount of information that can be stored reliably in a given volume of discrete
+spin systems which are supported by gapped local Hamiltonians. However, all the
+previously known systems were far below this theoretical bound, and it remained
+open whether there exists a gapped spin system that saturates this bound. Here,
+we present a construction of spin systems which saturate this theoretical limit
+asymptotically by borrowing an idea from fractal properties arising in the
+Sierpinski triangle. Our construction provides not only the best classical
+error-correcting code which is physically realizable as the energy ground space
+of gapped frustration-free Hamiltonians, but also a new research avenue for
+correlated spin phases with fractal spin configurations.",1111.3275v3
+2011-11-29,"Two solar-mass compact stars: structure, composition, and cooling","I discuss the structure and composition of massive (two solar-mass) neutron
+stars containing hypernuclear and deconfined quark matter in color
+superconducting states. Stable configurations featuring such matter are
+obtained if the equation of state of hadronic matter is stiff above the
+saturation density, the transition to quark matter takes place at a few times
+the nuclear saturation density, and the repulsive vector interactions in quark
+matter are substantial. I also discuss our recent progress in understanding the
+cooling of massive compact stars with color superconducting quark cores.",1111.6929v3
+2011-12-02,Geometric scaling in ultrahigh energy neutrinos and nonlinear perturbative QCD,"The ultrahigh energy neutrino cross section is a crucial ingredient in the
+calculation of the event rate in high energy neutrino telescopes. Currently
+there are several approaches which predict different behaviors for its
+magnitude for ultrahigh energies. In this contribution is presented a summary
+of current predictions based on the non-linear QCD evolution equations, the
+so-called perturbative saturation physics. In particular, predictions are shown
+based on the parton saturation approaches and the consequences of geometric
+scaling property at high energies are discussed. The scaling property allows an
+analytical computation of the neutrino scattering on nucleon/nucleus at high
+energies, providing a theoretical parameterization.",1112.0555v1
+2011-12-05,One-loop Factorization for Inclusive Hadron Production in $pA$ Collisions in the Saturation Formalism,"We demonstrate the QCD factorization for inclusive hadron production in $pA$
+collisions in the saturation formalism at one-loop order, with explicit
+calculation of both real and virtual gluon radiation diagrams. The collinear
+divergences associated with the incoming parton distribution of the nucleon and
+the outgoing fragmentation function of the final state hadron, as well as the
+rapidity divergence with small-$x$ dipole gluon distribution of the nucleus are
+factorized into the splittings of the associated parton distribution and
+fragmentation functions and the energy evolution of the dipole gluon
+distribution function. The hard coefficient function is evaluated at one-loop
+order, and contains no divergence.",1112.1061v1
+2011-12-16,Small-Signal Capacitance and Current Parameter Modeling in Large-Scale High-Frequency Graphene Field-Effect Transistors,"The analytical model of the small-signal current and capacitance
+characteristics of RF graphene FET is presented. The model is based on explicit
+distributions of chemical potential in graphene channels (including ambipolar
+conductivity at high source-drain bias) obtained in the framework of
+drift-diffusion current continuity equation solution. Small-signal
+transconductance and output conductance characteristics are modeled taking into
+account the two modes of drain current saturation including drift velocity
+saturation or electrostatic pinch-off. Analytical closed expression for the
+complex current gain and the cutoff frequency of high-frequency GFETs are
+obtained. The model allows describe an impact of parasitic resistances,
+capacitances, interface traps on extrinsic current gain and cut-off frequency.",1112.3856v1
+2011-12-17,A note on $\aleph_α$-saturated o-minimal expansions of real closed fields,"We give necessary and sufficient conditions for a polynomially bounded
+o-minimal expansion of a real closed field (in a language of arbitrary
+cardinality) to be $\aleph_{\alpha}$-saturated. The conditions are in terms of
+the value group, residue field, and pseudo- Cauchy sequences of the natural
+valuation on the real closed field. This is achieved by an analysis of types,
+leading to the trichotomy. Our characterization provides a construction method
+for saturated models, using fields of generalized power series.",1112.4078v3
+2011-12-18,Uncommon Suffix Tries,"Common assumptions on the source producing the words inserted in a suffix
+trie with $n$ leaves lead to a $\log n$ height and saturation level. We provide
+an example of a suffix trie whose height increases faster than a power of $n$
+and another one whose saturation level is negligible with respect to $\log n$.
+Both are built from VLMC (Variable Length Markov Chain) probabilistic sources;
+they are easily extended to families of sources having the same properties. The
+first example corresponds to a ""logarithmic infinite comb"" and enjoys a non
+uniform polynomial mixing. The second one corresponds to a ""factorial infinite
+comb"" for which mixing is uniform and exponential.",1112.4131v2
+2012-01-27,Calibration System with Optical Fibers for Calorimeters at Future Linear Collider Experiments,"We report on several versions of the calibration and monitoring system
+dedicated to scintillator tile calorimeters built within the CALICE
+collaboration and intended for future linear collider experiments. Whereas the
+first, a 1 m3 analogue hadron calorimeter prototype, was already built and
+tested in beam, second-technological prototype-is currently being developed.
+Both prototypes are based on scintillating tiles that are individually read out
+by new photodetectors, silicon photomultipliers (SiPMs). Since the SiPM
+response shows a strong dependence on the temperature and bias voltage and the
+SiPM saturates due to the limited number of pixels, it needs to be monitored.
+The monitoring system has to have sufficient flexibility to perform several
+different tasks. The self-calibration property of the SiPMs can be used for the
+gain monitoring using a low intensity of the LED light. A routine monitoring of
+all SiPMs during test beam operations is achieved with a fixed-intensity light
+pulse. The full SiPM response function is cross-checked by varying the light
+intensity from zero to the saturation level. We concentrate especially on the
+last aspect - the high dynamic range.",1201.5762v1
+2012-02-03,Dark lattice solitons in one-dimensional waveguide arrays with defocusing saturable nonlinearities and alternating couplings,"In the present work, we examine ""binary"" waveguide arrays, where the coupling
+between adjacent sites alternates between two distinct values $C_1$ and $C_2$
+and a saturable nonlinearity is present on each site. Motivated by experimental
+investigations of this type of system in fabricated LiNbO$_3$ arrays, we
+proceed to analyze the nonlinear wave excitations arising in the
+self-defocusing nonlinear regime, examining, in particular, dark solitons and
+bubbles. We find that such solutions may, in fact, possess a reasonably wide,
+experimentally relevant parametric interval of stability, while they may also
+feature both prototypical types of instabilities, namely exponential and
+oscillatory ones, for the same configuration. The spectral properties of the
+linearization around the solutions and the presence of two bands and associated
+mini-gaps are discussed and the nontrivial differences from the standard cubic
+discrete nonlinear Schr{\""o}dinger model are highlighted.",1202.0830v3
+2012-02-29,Fluctuating Glasma initial conditions and flow in heavy ion collisions,"We compute initial conditions in heavy-ion collisions within the Color Glass
+Condensate (CGC) framework by combining the impact parameter dependent
+saturation model (IP-Sat) with the classical Yang-Mills description of initial
+Glasma fields. In addition to fluctuations of nucleon positions, this IP-Glasma
+description includes quantum fluctuations of color charges on the length-scale
+determined by the inverse nuclear saturation scale Q_s. The model naturally
+produces initial energy fluctuations that are described by a negative binomial
+distribution. The ratio of triangularity to eccentricity is close to that in a
+model tuned to reproduce experimental flow data. We compare transverse momentum
+spectra and v_(2,3,4)(p_T) of pions from different models of initial conditions
+using relativistic viscous hydrodynamic evolution.",1202.6646v2
+2012-03-02,One-Loop BPS amplitudes as BPS-state sums,"Recently, we introduced a new procedure for computing a class of one-loop
+BPS-saturated amplitudes in String Theory, which expresses them as a sum of
+one-loop contributions of all perturbative BPS states in a manifestly T-duality
+invariant fashion. In this paper, we extend this procedure to all BPS-saturated
+amplitudes of the form \int_F \Gamma_{d+k,d} {\Phi}, with {\Phi} being a weak
+(almost) holomorphic modular form of weight -k/2. We use the fact that any such
+{\Phi} can be expressed as a linear combination of certain absolutely
+convergent Poincar\'e series, against which the fundamental domain F can be
+unfolded. The resulting BPS-state sum neatly exhibits the singularities of the
+amplitude at points of gauge symmetry enhancement, in a chamber-independent
+fashion. We illustrate our method with concrete examples of interest in
+heterotic string compactifications.",1203.0566v4
+2012-03-04,Properties of inclusive hadron production in Deep Inelastic Scattering on heavy nuclei at low x,"In this paper we present a comprehensive study of inclusive hadron production
+in DIS at low $x$. Properties of the hadron spectrum are different in different
+kinematic regions formed by three relevant momentum scales: photon virtuality
+$Q^2$, hadron transverse momentum $k_T$ and the saturation momentum $Q_s(x)$.
+We investigate each kinematic region and derive the corresponding asymptotic
+formulas for the cross section at the leading logarithmic order. We also
+analyze the next-leading-order (NLO) corrections to the BFKL kernel that are
+responsible for the momentum conservation. In particular, we establish the
+asymptotic behavior of the forward elastic dipole--nucleus scattering amplitude
+at high energies deeply in the saturation regime and a modification of the
+pomeron intercept. We study the nuclear effect on the inclusive cross section
+using the nuclear modification factor and its logarithmic derivative. We argue
+that the later is proportional to the difference between the anomalous
+dimension of the gluon distribution in nucleus and in proton and thus is a
+direct measure of the coherence effects. To augment our arguments and present
+quantitative results we performed numerical calculations in the kinematic
+region that may be accessible by the future DIS experiments.",1203.0775v1
+2012-03-27,High multiplicity pp events and J/ψ production at LHC,"We discuss the dependence of J/\psi\ production on the charged particle
+multiplicity in proton-proton collisions at LHC energies. We show that, in the
+framework of parton saturation or string interaction models, the hard J/\psi\
+production exhibits a significant growth with the multiplicity, which is
+stronger than linear in the high density domain. This departure from linearity,
+that should affect any hard observable, applies for high multiplicity
+proton-proton collisions in the central rapidity region and is a consequence of
+the parton saturation or the strong interaction among colour ropes that take
+place at LHC energies. Our assumption, the existence of coherence effects
+present in proton-proton collisions at high energy, can also be checked by
+studying the particular shape of the probability distribution associated to the
+J/\psi\ production.",1203.5936v1
+2012-03-28,Mendler-style Iso-(Co)inductive predicates: a strongly normalizing approach,"We present an extension of the second-order logic AF2 with iso-style
+inductive and coinductive definitions specifically designed to extract programs
+from proofs a la Krivine-Parigot by means of primitive (co)recursion
+principles. Our logic includes primitive constructors of least and greatest
+fixed points of predicate transformers, but contrary to the common approach, we
+do not restrict ourselves to positive operators to ensure monotonicity, instead
+we use the Mendler-style, motivated here by the concept of monotonization of an
+arbitrary operator on a complete lattice. We prove an adequacy theorem with
+respect to a realizability semantics based on saturated sets and
+saturated-valued functions and as a consequence we obtain the strong
+normalization property for the proof-term reduction, an important feature which
+is absent in previous related work.",1203.6158v1
+2012-03-31,Breakdown of chiral symmetry during saturation of the Tayler instability,"We study spontaneous breakdown of chiral symmetry during the nonlinear
+evolution of the Tayler instability. We start with an initial steady state of
+zero helicity. Within linearized perturbation calculations, helical
+perturbations of this initial state have the same growth rate for either sign
+of helicity. Direct numerical simulations (DNS) of the fully nonlinear
+equations, however, show that an infinitesimal excess of one sign of helicity
+in the initial perturbation gives rise to a saturated helical state. We further
+show that this symmetry breaking can be described by weakly nonlinear
+finite--amplitude equations with undetermined coefficients which can be deduced
+solely from symmetry consideration. By fitting solutions of the amplitude
+equations to data from DNS we further determine the coefficients of the
+amplitude equations.",1204.0081v2
+2012-03-31,A viscoplasticity model with an enhanced control of the yield surface distortion,"A new model of metal viscoplasticity, which takes combined isotropic,
+kinematic, and distortional hardening into account, is presented. The basic
+modeling assumptions are illustrated using a new two-dimensional rheological
+analogy. This demonstrative rheological model is used as a guideline for the
+construction of constitutive relations. The nonlinear kinematic hardening is
+captured using the well-known Armstrong-Frederick approach. The distortion of
+the yield surface is described with the help of a so-called distortional
+backstress. A distinctive feature of the model is that any smooth convex
+saturated form of the yield surface which is symmetric with respect to the
+loading direction can be captured. In particular, an arbitrary sharpening of
+the saturated yield locus in the loading direction combined with a flattening
+on the opposite side can be covered. Moreover, the yield locus evolves smoothly
+and its convexity is guaranteed at each hardening stage. A strict proof of the
+thermodynamic consistency is provided. Finally, the predictive capabilities of
+the material model are verified using the experimental data for a very high
+work hardening annealed aluminum alloy 1100 Al.",1204.0086v1
+2012-04-05,Prompt photon production and photon-hadron correlations at RHIC and the LHC from the Color Glass Condensate,"We investigate inclusive prompt photon and semi-inclusive prompt
+photon-hadron production in high energy proton-nucleus collisions using the
+Color Glass Condensate (CGC) formalism which incorporates non-linear dynamics
+of gluon saturation at small x via Balitsky-Kovchegov equation with running
+coupling. For inclusive prompt photon production, we rewrite the cross-section
+in terms of direct and fragmentation contributions and show that the direct
+photon (and isolated prompt photon) production is more sensitive to gluon
+saturation effects. We then analyze azimuthal correlations in photon-hadron
+production in high energy proton-nucleus collisions and obtain a strong
+suppression of the away-side peak in photon-hadron correlations at forward
+rapidities, similar to the observed mono-jet production in deuteron-gold
+collisions at forward rapidity at RHIC. We make predictions for the nuclear
+modification factor R_{p(d)A} and photon-hadron azimuthal correlations in
+proton(deuteron)-nucleus collisions at RHIC and the LHC at various rapidities.",1204.1319v2
+2012-04-17,Locality for quantum systems on graphs depends on the number field,"Adapting a definition of Aaronson and Ambainis [Theory Comput. 1 (2005),
+47--79], we call a quantum dynamics on a digraph ""saturated Z-local"" if the
+nonzero transition amplitudes specifying the unitary evolution are in exact
+correspondence with the directed edges (including loops) of the digraph. This
+idea appears recurrently in a variety of contexts including angular momentum,
+quantum chaos, and combinatorial matrix theory. Complete characterization of
+the digraph properties that allow such a process to exist is a long-standing
+open question that can also be formulated in terms of minimum rank problems. We
+prove that saturated Z-local dynamics involving complex amplitudes occur on a
+proper superset of the digraphs that allow restriction to the real numbers or,
+even further, the rationals. Consequently, among these fields, complex numbers
+guarantee the largest possible choice of topologies supporting a discrete
+quantum evolution. A similar construction separates complex numbers from the
+skew field of quaternions. The result proposes a concrete ground for
+distinguishing between complex and quaternionic quantum mechanics.",1204.3681v2
+2012-05-03,What ecological factors shape species-area curves in neutral models?,"Understanding factors that shape biodiversity and species coexistence across
+scales is of utmost importance in ecology, both theoretically and for
+conservation policies. Species-area relationships (SARs), measuring how the
+number of observed species increases upon enlarging the sampled area,
+constitute a convenient tool for quantifying the spatial structure of
+biodiversity. While general features of species-area curves are quite universal
+across ecosystems, some quantitative aspects can change significantly. Several
+attempts have been made to link these variations to ecological forces. Within
+the framework of spatially explicit neutral models, here we scrutinize the
+effect of varying the local population size (i.e. the number of individuals per
+site) and the level of habitat saturation (allowing for empty sites). We
+conclude that species-area curves become shallower when the local population
+size increases, while habitat saturation, unless strongly violated, plays a
+marginal role. Our findings provide a plausible explanation of why SARs for
+microorganisms are flatter than those for larger organisms.",1205.0665v1
+2012-05-14,Holographic Pomeron: Saturation and DIS,"We briefly review the approach to dipole-dipole scattering in holographic QCD
+developed in ARXIV:1202.0831. The Pomeron is modeled by exchanging closed
+strings between the dipoles and yields Regge behavior for the elastic
+amplitude. We calculate curvature corrections to this amplitude in both a
+conformal and confining background, identifying the holographic direction with
+the virtuality of the dipoles. The it wee-dipole density is related to the
+string tachyon diffusion in both virtuality and the transverse directions. We
+give an explicit derivation of the dipole saturation momentum both in the
+conformal and confining metric. Our holographic result for the dipole-dipole
+cross section and the it wee-dipole density in the conformal limit are shown to
+be identical in form to the BFKL pomeron result when the non-critical string
+transverse dimension is $D_\perp=3$. The total dipole-dipole cross section is
+compared to DIS data from HERA.",1205.3223v3
+2012-05-17,Heavy Sterile Neutrinos and Neutrinoless Double Beta Decay,"Sterile neutrinos of mass up to a few tens of TeV can saturate the present
+experimental bound of neutrinoless double beta decay process. Due to the
+updated nuclear matrix elements, the bound on mass and mixing angle is now
+improved by one order of magnitude. We have performed a detailed analysis of
+neutrinoless double beta decay for the minimal Type I seesaw scenario. We have
+shown that in spite of the naive expectation that the light neutrinos give the
+dominant contribution, sterile neutrinos can saturate the present experimental
+bound of neutrinoless double beta decay process. However, in order to be
+consistent with radiative stability of light neutrino masses, the mass scale of
+sterile neutrinos should be less than 10 GeV.",1205.3867v1
+2012-05-23,The Unique Pure Gaussian State Determined by the Partial Saturation of the Uncertainty Relations of a Mixed Gaussian State,"Let {\rho} the density matrix of a mixed Gaussian state. Assuming that one of
+the Robertson--Schr\""odinger uncertainty inequalities is saturated by {\rho},
+e.g.
+({\Delta}^{{\rho}}X_1)^2({\Delta}^{{\rho}}P_1)^2={\Delta}^{{\rho}}(X_1,P_1)^2+(1/4)\hbar^2,
+we show that there exists a unique pure Gaussian state whose Wigner
+distribution is dominated by that of {\rho} and having the same variances and
+covariance {\Delta}^{{\rho}}X_1,{\Delta}^{{\rho}}P_1, and
+{\Delta}^{{\rho}}(X_1,P_1) as {\rho}. This property can be viewed as an
+analytic version of Gromov's non-squeezing theorem in the linear case, which
+implies that the intersection of a symplectic ball by a single plane of
+conjugate coordinates determines the radius of this ball.",1205.5222v1
+2012-06-11,Analytic approach to the motion of cosmological phase transition fronts,"We consider the motion of planar phase-transition fronts in first-order phase
+transitions of the Universe. We find the steady state wall velocity as a
+function of a friction coefficient and thermodynamical parameters, taking into
+account the different hydrodynamic modes of propagation. We obtain analytical
+approximations for the velocity by using the thin wall approximation and the
+bag equation of state. We compare our results to those of numerical
+calculations and discuss the range of validity of the approximations. We
+analyze the structure of the stationary solutions. Multiple solutions may exist
+for a given set of parameters, even after discarding non-physical ones. We
+discuss which of these will be realized in the phase transition as the
+stationary wall velocity. Finally, we discuss on the saturation of the friction
+at ultra-relativistic velocities and the existence of runaway solutions.",1206.2339v2
+2012-06-30,Hypernclear in the improved quark mass density- dependent model,"The improved quark mass density- dependent model, which has been successfully
+used to describe the properties of both finite nuclei and bulk nuclear matter,
+is extended to include the strange quark. The parameters of the model are
+determined by the saturation properties of bulk matter. Then the given
+parameter set is employed to investigate both the properties of strange
+hadronic matter and those of $\Lambda$ hypernuclei. Bulk strange hadronic
+matter consisting of nucleons, $\Lambda$- hyperons and $\Xi$- hyperons is
+studied under mean-field approximation. Among others, density dependence of the
+effective baryon mass, saturation properties and stability of the physical
+system are discussed. For single-$\Lambda$ hypernuclei, single particle
+energies of $\Lambda$ hyperon is evaluated. In particular, it is found that the
+present model produces a small spin-orbit interaction, which is in agreement
+with the experimental observations. The above results show that the present
+model can consistently describe the properties of strange hadronic matter, as
+well as those of single $\Lambda$ hypernuclei within an uniform
+parameterization.",1207.0070v1
+2012-07-03,Robust Dequantized Compressive Sensing,"We consider the reconstruction problem in compressed sensing in which the
+observations are recorded in a finite number of bits. They may thus contain
+quantization errors (from being rounded to the nearest representable value) and
+saturation errors (from being outside the range of representable values). Our
+formulation has an objective of weighted $\ell_2$-$\ell_1$ type, along with
+constraints that account explicitly for quantization and saturation errors, and
+is solved with an augmented Lagrangian method. We prove a consistency result
+for the recovered solution, stronger than those that have appeared to date in
+the literature, showing in particular that asymptotic consistency can be
+obtained without oversampling. We present extensive computational comparisons
+with formulations proposed previously, and variants thereof.",1207.0577v2
+2012-07-31,Particle Production in pA Collisions and QCD Saturation,"The forthcoming LHC measurements in proton-nucleus (pA) collisions at forward
+rapidities can discriminate between the color glass condensate (CGC) and
+alternative approaches including standard collinear factorization one. We
+report some of our recent predictions based on gluon saturation/CGC formalism
+for pA collisions at the LHC including the charged hadron multiplicity
+distribution, the nuclear modification factor for single inclusive hadron and
+prompt photon production, and the azimuthal angle correlation of the
+semi-inclusive hadron-photon production.",1208.0026v2
+2012-09-12,Channel Length Scaling of MoS2 MOSFETs,"In this article, we investigate electrical transport properties in ultrathin
+body (UTB) MoS2 two-dimensional (2D) crystals with channel lengths ranging from
+2 {\mu}m down to 50 nm. We compare the short channel behavior of sets of
+MOSFETs with various channel thickness, and reveal the superior immunity to
+short channel effects of MoS2 transistors. We observe no obvious short channel
+effects on the device with 100 nm channel length (Lch) fabricated on a 5 nm
+thick MoS2 2D crystal even when using 300 nm thick SiO2 as gate dielectric, and
+has a current on/off ratio up to ~109. We also observe the on-current
+saturation at short channel devices with continuous scaling due to the carrier
+velocity saturation. Also, we reveal the performance limit of short channel
+MoS2 transistors is dominated by the large contact resistance from the Schottky
+barrier between Ni and MoS2 interface, where a fully transparent contact is
+needed to achieve a high-performance short channel device.",1209.2525v1
+2012-09-19,Single Dirac-cone on the Cs-covered topological insulator surface Sb2Te3(0001),"Using angle-resolved photoelectron spectroscopy we investigate the surface
+electronic structure of the three-dimensional topological insulator (TI)
+Sb2Te3(0001). Our data show the presence of a topological surface state in the
+bulk energy gap with the Dirac-point located above the Fermi level. The
+adsorption of Cs-atoms on Sb2Te3(0001) gives rise to a downward energy shift of
+the electronic valence band states which saturates at a value of ~200 meV. For
+the saturation coverage the Dirac-point of the linearly dispersive surface
+state resides in close proximity to the Fermi level. The electronic structure
+of the Cs/Sb2Te3 interface therefore considerably deviates from previously
+studied metal-TI interfaces based on the isostructural compound Bi2Se3 which
+points to the importance of atomic composition in these hetero systems.",1209.4263v1
+2012-09-23,A gauged baby Skyrme model and a novel BPS bound,"The baby Skyrme model is a well-known nonlinear field theory supporting
+topological solitons in two space dimensions. Its action functional consists of
+a potential term, a kinetic term quadratic in derivatives (the ""nonlinear sigma
+model term"") and the Skyrme term quartic in first derivatives. The limiting
+case of vanishing sigma model term (the so-called BPS baby Skyrme model) is
+known to support exact soliton solutions saturating a BPS bound which exists
+for this model. Further, the BPS model has infinitely many symmetries and
+conservation laws. Recently it was found that the gauged version of the BPS
+baby Skyrme model with gauge group U(1) and the usual Maxwell term, too, has a
+BPS bound and BPS solutions saturating this bound. This BPS bound is determined
+by a superpotential which has to obey a superpotential equation, in close
+analogy to the situation in supergravity. Further, the BPS bound and the
+corresponding BPS solitons only may exist for potentials such that the
+superpotential equation has a global solution. We also briefly describe some
+properties of soliton solutions.",1209.5103v1
+2012-10-18,Eigenvalues of Hermitian matrices and equivariant cohomology of Grassmannians,"The saturation theorem of [Knutson-Tao '99] concerns the nonvanishing of
+Littlewood-Richardson coefficients. In combination with work of [Klyachko '98],
+it implies [Horn '62]'s conjecture about eigenvalues of sums of Hermitian
+matrices. This eigenvalue problem has a generalization [Friedland '00] to
+majorized sums of Hermitian matrices.
+  We further illustrate the common features between these two eigenvalue
+problems and their connection to Schubert calculus of Grassmannians. Our main
+result gives a Schubert calculus interpretation of Friedland's problem, via
+equivariant cohomology of Grassmannians. In particular, we prove a saturation
+theorem for this setting. Our arguments employ the aformentioned work together
+with [Thomas-Yong '12].",1210.5003v2
+2012-11-04,Flame Acceleration in Channels with Obstacles in the Deflagration-to-Detonation Transition,"It was demonstrated recently in Bychkov et al., Phys. Rev. Lett. 101 (2008)
+164501, that the physical mechanism of flame acceleration in channels with
+obstacles is qualitatively different from the classical Shelkin mechanism. The
+new mechanism is much stronger, and is independent of the Reynolds number. The
+present study provides details of the theory and numerical modeling of the
+flame acceleration. It is shown theoretically and computationally that flame
+acceleration progresses noticeably faster in the axisymmetric cylindrical
+geometry as compared to the planar one, and that the acceleration rate reduces
+with increasing initial Mach number and thereby the gas compressibility.
+Furthermore, the velocity of the accelerating flame saturates to a constant
+value that is supersonic with respect to the wall. The saturation state can be
+correlated to the Chapman-Jouguet deflagration as well as the fast flames
+observed in experiments. The possibility of transition from deflagration to
+detonation in the obstructed channels is demonstrated.",1211.0655v1
+2012-11-12,Theory of self-organized traffic at light signal,"Based on numerical simulations of a three-phase traffic flow model, a
+probabilistic theory of traffic at the light signal is developed. We have found
+that very complex spatiotemporal self-organized phenomena determine features of
+city traffic. We have revealed that the breakdown of {\it green wave} in a city
+is initiated by the emergence of a moving synchronized flow pattern (MSP)
+within the green wave. It turns out that a sequence of
+F$\rightarrow$S$\rightarrow$J transitions (F -- free flow, S -- synchronized
+flow, J -- moving queue) lead to traffic breakdown at the light signal. Both
+spontaneous and induced breakdowns of the green wave have been found. From a
+study of a variety of scenarios for arrival traffic, we have found that there
+are the infinite number of capacities of traffic at the light signal, which are
+in a capacity range between a minimum capacity and maximum capacity; each of
+the capacities gives a flow rate at which under-saturated traffic is in a
+metastable state with respect to the transition to over-saturated traffic. The
+maximum capacity depends crucially on a time-dependence of the flow rate: The
+larger the number of vehicles that arrive the light signal during the green
+phase, the larger the maximum capacity.",1211.2535v1
+2012-11-13,Quarkonium at non-zero isospin density,"We calculate the energies of quarkonium bound states in the presence of a
+medium of nonzero isospin density using lattice QCD. The medium, created using
+a canonical (fixed isospin charge) approach, induces a reduction of the
+quarkonium energies. As the isospin density increases, the energy shifts first
+increase and then saturate. The saturation occurs at an isospin density close
+to that where previously a qualitative change in the behaviour of the energy
+density of the medium has been observed, which was conjectured to correspond to
+a transition from a pion gas to a Bose-Einstein condensed phase. The reduction
+of the quarkonium energies becomes more pronounced as the heavy-quark mass is
+decreased, similar to the behaviour seen in two-colour QCD at non-zero quark
+chemical potential. In the process of our analysis, the $\eta_b$-$\pi$ and
+$\Upsilon$-$\pi$ scattering phase shifts are determined at low momentum. An
+interpolation of the scattering lengths to the physical pion mass gives
+$a_{\eta_b,\pi} = 0.0025(8)(6)$ fm and $a_{\Upsilon,\pi} = 0.0030(9)(7)$ fm.",1211.3156v3
+2012-11-29,Polymer Welding: Strength Through Entanglements,"Large-scale simulations of thermal welding of polymers are performed to
+investigate the rise of mechanical strength at the polymer-polymer interface
+with the welding time. The welding process is in the core of integrating
+polymeric elements into devices as well as in thermal induced healing of
+polymers; processes that require development of interfacial strength equal to
+that of the bulk. Our simulations show that the interfacial strength saturates
+at the bulk shear strength much before polymers diffuse by their radius of
+gyration. Along with the strength increase, the dominant failure mode changes
+from chain pullout at the interface to chain scission as in the bulk. Formation
+of sufficient entanglements across the interface, which we track using a
+Primitive Path Analysis is required to arrest catastrophic chain pullout at the
+interface. The bulk response is not fully recovered until the density of
+entanglements at the interface reaches the bulk value. Moreover, the increase
+of interfacial strength before saturation is proportional to the number of
+interfacial entanglements between chains from opposite sides.",1211.6796v1
+2012-12-03,Recent progress on the determination of the symmetry Energy,"We summarize the current status on constraining the density dependence of the
+symmetry energy from terrestrial laboratory measurements and astrophysical
+observations. While the value $E_{sym}({\rho_{0}})$ and density slope $L$ of
+the symmetry energy at saturation density $\rho_{0}$ can vary largely depending
+on the data or methods, all the existing constraints are essentially consistent
+with $E_{sym}({\rho_{0}}) = 31 \pm 2$ MeV and $L = 50 \pm 20$ MeV. The
+determination of the supra-saturation density behavior of the symmetry energy
+remains a big challenge.",1212.0284v1
+2012-12-11,Spatial correlations of Rydberg excitations in optically driven atomic ensembles,"We study the emergence of many-body correlations in the stationary state of
+continuously-driven, strongly-interacting dissipative system. Specifically, we
+examine resonant optical excitations of Rydberg states of atoms interacting via
+long-range dipole-dipole and van der Waals potentials employing exact numerical
+solutions of the density matrix equations and Monte-Carlo simulations.
+Collection of atoms within a blockade distance form a ""superatom"" that can
+accommodate at most one Rydberg excitation. The superatom excitation
+probability saturates to 1/2 for coherently driven atoms, but is significantly
+higher for incoherent driving, approaching unity as the number of atoms
+increases. In the steady state of uniformly-driven, extended one-dimensional
+system, the saturation of superatoms leads to quasi-crystallization of Rydberg
+excitations whose correlations exhibit damped spatial oscillations. The
+behavior of the system under the van der Waals interaction potential can be
+approximated by an analytically soluble model based on a ""hard-rod"" interatomic
+potential.",1212.2423v1
+2012-12-12,Lifshitz field theories with SDiff symmetries,"We consider Lifshitz field theories with a dynamical critical exponent z
+equal to the dimension of space d and with a large group of base space
+symmetries, concretely space coordinate transformations with unit determinant
+(""Special Diffeomorphisms""). The field configurations of the theories
+considered may have the topology of skyrmions, vortices or monopoles, although
+we focus our detailed investigations on skyrmions. The resulting Lifshitz field
+theories have a BPS bound and exact soliton solutions saturating the bound, as
+well as time-dependent topological Q-ball solutions. Finally, we investigate
+the U(1) gauged versions of the Lifshitz field theories coupled to a
+Chern-Simons gauge field, where the BPS bound and soliton solutions saturating
+the bound continue to exist.",1212.2741v2
+2012-12-21,Inclusive hadron and photon production at LHC in dipole momentum space,"Using a momentum space model for the dipole scattering amplitude we present
+an analysis of the saturation effects at LHC energies, describing the data on
+proton-proton and proton-lead collisions. The model is based on the asymptotic
+solutions of the Balitsky-Kovchegov equation, being ideal in the saturation
+domain where the target wave function has a high occupation number. We also
+make predictions for the nuclear modification ratios on charged hadron and
+prompt photon production in the forward region, where the high parton density
+effects are important.",1212.5549v2
+2012-12-24,Interplay between the symmetry energy and the strangeness content of neutron stars,"The effect of the density dependence of the nucleonic equation of state and
+the hyperon meson couplings on the star properties, including strangeness
+content, mass and radius, are studied within a relativistic mean field
+formalism. It is shown that there is still lacking information on the nucleonic
+equation of state at supra-saturation densities and on the hyperon interactions
+in nuclear matter that will allow a clear answer to the question whether the
+mass of the pulsar J1614-2230 could rule out exotic degrees of freedom from the
+interior of compact stars. We show that some star properties are affected in a
+similar way by the density dependence of the symmetry energy and the hyperon
+content of the star. To disentangle these two effects it is essential to have a
+good knowledge of the equation of state at supra-saturation densities. A linear
+correlation between the radius and the strangeness content of a star with a
+fixed mass is obtained.",1212.5911v3
+2013-01-03,Strangeness-driven phase transition in (proto)- neutron star matter,"The phase diagram of a system constituted of neutrons, protons,
+$\Lambda$-hyperons and electrons is evaluated in the mean-field approximation
+in the complete three-dimensional space given by the baryon, lepton and strange
+charge. It is shown that the phase diagram at sub-saturation densities is
+strongly affected by the electromagnetic interaction, while it is almost
+independent of the electric charge at supra-saturation density. As a
+consequence, stellar matter under the condition of strangeness equilibrium is
+expected to experience a first as well as a second-order strangeness-driven
+phase transition at high density, while the liquid-gas phase transition is
+expected to be quenched. An RPA calculation indicates that the presence of this
+critical point might have sizable implications for the neutrino propagation in
+core-collapse supernovae.",1301.0390v2
+2013-01-08,High Frequency Geodesic Acoustic Modes in Electron Scale Turbulence,"In this work the finite $\beta$-effects of an electron branch of the geodesic
+acoustic mode (el-GAM) driven by electron temperature gradient (ETG) modes is
+presented. The work is based on a fluid description of the ETG mode retaining
+non-adiabatic ions and the dispersion relation for el-GAMs driven non-linearly
+by ETG modes is derived. The ETG growth rate from the fluid model is compared
+to the results found from gyrokinetic simulations with good agreement. A new
+saturation mechanism for ETG turbulence through the interaction with el-GAMs is
+found, resulting in a significantly enhanced ETG turbulence saturation level
+compared to the mixing length estimate. It is shown that the el-GAM may be
+stabilized by an increase in finite $\beta$ as well as by increasing
+non-adiabaticity. The decreased GAM growth rates is due to the inclusion of the
+Maxwell stress.",1301.1435v2
+2013-01-31,The Third Proof of Lovász's Cathedral Theorem,"A graph $G$ with a perfect matching is called saturated if $G+e$ has more
+perfect matchings than $G$ for any edge $e$ that is not in $G$. Lov\'asz gave a
+characterization of the saturated graphs called the cathedral theorem, with
+some applications to the enumeration problem of perfect matchings, and later
+Szigeti gave another proof. In this paper, we give a new proof with our
+preceding works which revealed canonical structures of general graphs with
+perfect matchings. Here, the cathedral theorem is derived in quite a natural
+way, providing more refined or generalized properties. Moreover, the new proof
+shows that it can be proved without using the Gallai-Edmonds structure theorem.",1301.7597v3
+2013-02-01,BFKL Pomeron calculus: solution to equations for nucleus-nucleus scattering in the saturation domain,"In this paper we solve the equation for nucleus-nucleus scattering in the
+BFKL Pomeron calculus, suggested by Braun. We find these solutions analytically
+at high energies as well as numerically in the entire region of energies inside
+the saturation region. The semi-classical approximation is used to select out
+the infinite set of the parasite solutions. The nucleus-nucleus cross sections
+at high energy are estimated and compared with the Glauber-Gribov approach. It
+turns out that the exact formula gives the estimates that are very close to the
+ones based on Glauber-Gribov formula which is important for the practical
+applications",1302.0128v1
+2013-02-01,Three-body force effect on off-shell mass operator and spectral functions in nuclear matter,"Within the framework of the Brueckner theory, the off-shell behaviors of the
+mass operator $M(k,\omega)=V(k,\omega)+iW(k,\omega)$, i.e., its dependence upon
+the momentum $k$ and upon the nucleon frequency $\omega$, are investigated by
+including nuclear three-body force (TBF). The first two terms of the hole-line
+expansion of the mass operator are taken into account. The TBF effects on their
+off-shell properties are discussed. A comparison is made between the on-shell
+and off-shell values of $M_{1}$. The nucleon spectral function and nucleon
+momentum distribution are also calculated, and the calculation shows that they
+are hardly affected by the TBF effect at the saturation density. At a high
+density two times greater than the saturation density, inclusion of the TBF may
+lead to a visible effect on the spectral function and may enhance the depletion
+of the hole states.",1302.0202v2
+2013-02-05,Scaling of Non-Saturating MR and quantum oscillations in pristine and ion-implanted HOPG,"A wide variety of resistive and field dependent behaviors have been
+previously observed in both doped and non-doped Highly Oriented Pyrolytic
+Graphite (HOPG). We find HOPG samples to vary significantly in their
+temperature dependent resistances, even between portions taken from the same
+sample, yet they exhibit consistent non-saturating magnetoresistance (MR). The
+scaling behavior of the MR is shown to be characteristic of a model based on
+the Hall effect in granular materials. In addition to the large, field-linear
+MR, all samples exhibit Shubnikov-de Haas (SdH) oscillations. Additional
+samples were doped via ion-implantation by boron and phosphorous, but show no
+signs of superconductivity nor any systematic change in their magnetoresistive
+behavior. Analysis of the SdH data gives a 2D carrier density in agreement with
+previous results, and a large mean-free path relative to crystallite size, even
+in samples with thin ion-implanted surface layers.",1302.1229v1
+2013-02-06,Nonequilbrium work by charge control in a Josephson junction,"We consider a single Josephson junction in the presence of time varying gate
+charge, and examine the nonequilibrium work done by the charge control in the
+framework of fluctuation theorems. We obtain the probability distribution
+functions of the works performed by forward protocol and by its time reversed
+protocol, which from the Crooks relation gives the estimation of the free
+energy changes \Delta F =0. The reliability of \Delta F estimated from the
+Jarzynksi equality is crucially dependent on protocol parameters, while
+Bennett's acceptance ratio method confirms consistently \Delta F=0. The error
+of the Jarzynski estimator either grows or becomes saturated as the duration of
+the work protocol increases, which depends on the protocol rapidity determining
+the existence of the oscillatory motion of the phase difference across the
+junction. The average of the work also shows similar behaviors and its
+saturation value is given by the relative weight of the oscillatory trajectory
+with respect to running trajectories with constant acceleration. We discuss
+non-negativity of the work average and its relation to heat and entropy
+production associated with the circuit control.",1302.1273v1
+2013-02-13,A Carbon Nanotube Immunosensor for Salmonella,"Antibody-functionalized carbon nanotube devices have been suggested for use
+as bacterial detectors for monitoring of food purity in transit from the farm
+to the kitchen. Here we report progress towards that goal by demonstrating
+specific detection of Salmonella in complex nutrient broth solutions using
+nanotube transistors functionalized with covalently-bound anti-Salmonella
+antibodies. The small size of the active device region makes them compatible
+with integration in large-scale arrays. We find that the on-state current of
+the transistor is sensitive specifically to the Salmonella concentration and
+saturates at low concentration (<1000 cfu/ml). In contrast, the carrier
+mobility is affected comparably by Salmonella and other bacteria types, with no
+sign of saturation even at much larger concentrations (10^8 cfu/ml).",1302.2959v1
+2013-02-15,Nonlinear effects and the behavior of total hadronic and photonic cross sections,"In this work we use an eikonalized minijet model where the effects of the
+first nonlinear corrections to the DGLAP equations are taken into account. The
+contributions coming from gluon recombination effects are included in the
+DGLAP+GLRMQ approach for the free proton in the context of saturation models.
+The parameters of the model are fixed to fit total $pp$ and $\bar p p$ cross
+sections, including the very recent data from LHC, HiRes and P. Auger
+Collaborations. Glauber and multiple scattering approximations are then used to
+describe the inclusive inelastic proton-Air cross section. Photoproduction
+cross sections, without change of parameters fixed before, are also obtained
+from the model using Vector Meson Dominance and the Additive Quark Model. We
+show and discuss our main results as well as the implications of saturation
+effects in the behavior of total hadronic and photonic cross sections at very
+high energies.",1302.3765v3
+2013-02-16,Effect of Temperature Wave on Diffusive Transport of Weakly-Soluble Substances in Liquid-Saturated Porous Media,"We study the effect of surface temperature oscillations on diffusive
+transport of solutes of weaklysoluble substances through liquid-saturated
+porous media. Temperature wave induced by these oscillations and decaying deep
+in the porous massif creates the solubility wave along with the corresponding
+solute diffusion flux wave. When the non-dissolved fraction is immobilized in
+pores---for gases the bubbles can be immobilized by the surface tension force,
+for solids (e.g., limestone, gas-hydrates) the immobilization of non-dissolved
+phase is obvious---the only remaining mechanisms of mass transport are related
+to solute flux through liquid in pores. We evaluate analytically the generated
+time-average mass flux for the case of medium everywhere littered with
+non-dissolved phase and reveal the significant effect of the temperature wave
+on the substance release from the massif and non-dissolved mass redistribution
+within the massif. Analytical theory is validated with numerical calculations.",1302.3966v3
+2013-02-18,Quantitative Study of Different Forms of Geometrical Scaling in Deep Inelastic Scattering at HERA,"We use recently proposed method of ratios to assess the quality of
+geometrical scaling in deep inelastic scattering for different forms of the
+saturation scale. We consider original form of geometrical scaling (motivated
+by the Balitski-Kovchegov (BK) equation with fixed coupling) studied in more
+detail in our previous paper, and four new hypotheses: phenomenologically
+motivated case with $Q^2$ dependent exponent $\lambda$ that governs small $x$
+dependence of the saturation scale, two versions of scaling (running coupling 1
+and 2) that follow from the BK equation with running coupling, and diffusive
+scaling suggested by the QCD evolution equation beyond mean field
+approximation. It turns out that more sophisticated scenarios: running coupling
+scaling and diffusive scaling are disfavored by the combined HERA data on
+$e^+p$ deep inelastic structure function $F_2$.",1302.4227v1
+2013-02-21,High-Field Electrical and Thermal Transport in Suspended Graphene,"We study the intrinsic transport properties of suspended graphene devices at
+high fields (>1 V/um) and high temperatures (>1000 K). Across 15 samples, we
+find peak (average) saturation velocity of 3.6x10^7 cm/s (1.7x10^7 cm/s), and
+peak (average) thermal conductivity of 530 W/m/K (310 W/m/K), at 1000 K. The
+saturation velocity is 2-4 times and the thermal conductivity 10-17 times
+greater than in silicon at such elevated temperatures. However, the thermal
+conductivity shows a steeper decrease at high temperature than in graphite,
+consistent with stronger effects of second-order three-phonon scattering. Our
+analysis of sample-to-sample variation suggests the behavior of ""cleaner""
+devices most closely approaches the intrinsic high-field properties of
+graphene. This study reveals key features of charge and heat flow in graphene
+up to device breakdown at ~2230 K in vacuum, highlighting remaining unknowns
+under extreme operating conditions.",1302.5440v2
+2013-02-28,Multiple light scattering on the F = 1 - F' = 0 transition in a cold and high density 87Rb vapor,"We report an experimental study of near resonance light scattering on the $F
+= 1 \rightarrow F' = 0$ component of the $D_2$ line in atomic $^{87}Rb$.
+Experiments are performed on spatially bi-Gaussian ultracold gas samples having
+peak densities ranging from about $5 \cdot 10^{12} - 5 \cdot 10^{13}$
+atoms/cm$^{3}$ and for a range of resonance saturation parameters and detunings
+from atomic resonance. Time resolution of the scattered light intensity reveals
+dynamics of multiple light scattering, optical pumping, and saturation effects.
+The experimental results in steady-state are compared qualitatively with
+theoretical models of the light scattering process. The steady-state line shape
+of the excitation spectrum is in good qualitative agreement with these models.",1303.0037v1
+2013-03-01,Performance of Spatially-Coupled LDPC Codes and Threshold Saturation over BICM Channels,"We study the performance of binary spatially-coupled low-density parity-check
+codes (SC-LDPC) when used with bit-interleaved coded-modulation (BICM) schemes.
+This paper considers the cases when transmission takes place over additive
+white Gaussian noise (AWGN)channels and Rayleigh fast-fading channels. The
+technique of upper bounding the maximum-a-posteriori (MAP) decoding performance
+of LDPC codes using an area theorem is extended for BICM schemes. The upper
+bound is computed for both the optimal MAP demapper and the suboptimal
+max-log-MAP (MLM) demapper. It is observed that this bound approaches the noise
+threshold of BICM channels for regular LDPC codes with large degrees. The rest
+of the paper extends these techniques to SC-LDPC codes and the phenomenon of
+threshold saturation is demonstrated numerically. Based on numerical evidence,
+we conjecture that the belief-propagation (BP) decoding threshold of SC-LDPC
+codes approaches the MAP decoding threshold of the underlying LDPC ensemble on
+BICM channels. Numerical results also show that SC-LDPC codes approach the BICM
+capacity over different channels and modulation schemes.",1303.0296v1
+2013-03-11,Interplay between localization and absorption in disordered waveguides,"This work presents results of ab-initio simulations of continuous wave
+transport in disordered absorbing waveguides. Wave interference effects cause
+deviations from diffusive picture of wave transport and make the diffusion
+coefficient position- and absorption-dependent. As a consequence, the true
+limit of a zero diffusion coefficient is never reached in an absorbing random
+medium of infinite size, instead, the diffusion coefficient saturates at some
+finite constant value. Transition to this absorption-limited diffusion exhibits
+a universality which can be captured within the framework of the
+self-consistent theory (SCT) of localization. The results of this work (i)
+justify use of SCT in analyses of experiments in localized regime, provided
+that absorption is not weak; (ii) open the possibility of diffusive description
+of wave transport in the saturation regime even when localization effects are
+strong.",1303.2717v1
+2013-03-14,Quantum Flutter: Signatures and Robustness,"We investigate the motion of an impurity particle injected with finite
+velocity into an interacting one-dimensional quantum gas. Using large-scale
+numerical simulations based on matrix product states, we observe and
+quantitatively analyze long-lived oscillations of the impurity momentum around
+a non-zero saturation value, called quantum flutter. We show that the quantum
+flutter frequency is equal to the energy difference between two branches of
+collective excitations of the model. We propose an explanation of the finite
+saturation momentum of the impurity based on the properties of the edge of the
+excitation spectrum. Our results indicate that quantum flutter exists away from
+integrability, and provide parameter regions in which it could be observed in
+experiments with ultracold atoms using currently available technology.",1303.3583v3
+2013-03-15,Polariton condensation with saturable molecules dressed by vibrational modes,"Polaritons, mixed light-matter quasiparticles, undergo a transition to a
+condensed, macroscopically coherent state at low temperatures or high
+densities. Recent experiments show that coupling light to organic molecules
+inside a microcavity allows condensation at room temperature. The molecules act
+as saturable absorbers with transitions dressed by molecular vibrational modes.
+Motivated by this we calculate the phase diagram and spectrum of a modified
+Tavis-Cummings model, describing vibrationally dressed two-level systems,
+coupled to a cavity mode. Coupling to vibrational modes can induce re-entrance,
+i.e. a normal-condensed-normal sequence with decreasing temperature and can
+drive the transition first order.",1303.3720v3
+2013-03-17,"Collisionless shock formation, spontaneous electromagnetic fluctuations and streaming instabilities","Collisionless shocks are ubiquitous in astrophysics and in the lab. Recent
+numerical simulations and experiments have shown how they can arise from the
+encounter of two collisionless plasma shells. When the shells interpenetrate,
+the overlapping region turns unstable, triggering the shock formation. As a
+first step towards a microscopic understanding of the process, we analyze here
+in detail the initial instability phase. On the one hand, 2D relativistic PIC
+simulations are performed where two symmetric initially cold pair plasmas
+collide. On the other hand, the instabilities at work are analyzed, as well as
+the field at saturation and the seed field which gets amplified. For mildly
+relativistic motions and onward, Weibel modes govern the linear phase. We
+derive an expression for the duration of the linear phase in good agreement
+with the simulations. This saturation time constitutes indeed a lower-bound for
+the shock formation time.",1303.4095v2
+2013-03-27,Transient Charge and Energy Balance in Graphene Induced by Ultrafast Photoexcitation,"Ultrafast optical pump-probe spectroscopy measurement on monolayer graphene
+observes significant optical nonlinearities. We show that strongly photoexcited
+graphene monolayers with 35 fs pulses quasi-instantaneously build up a
+broadband, inverted Dirac fermion population. Optical gain emerges and directly
+manifests itself via a negative conductivity at the near-infrared region for
+the first 200fs, where stimulated emission completely compensates absorption
+loss in the graphene layer. To quantitatively investigate this transient,
+extremely dense photoexcited Dirac-fermion state, we construct a
+two-chemical-potential model, in addition to a time-dependent transient carrier
+temperature above lattice temperature, to describe the population inverted
+electronic state metastable on the time scale of tens of femtoseconds generated
+by a strong exciting pulse. The calculated transient optical conductivity
+reveals a complete bleaching of absorption, which sets the saturation density
+during the pulse propagation. Particularly, the model calculation reproduces
+the negative optical conductivity at lower frequencies in the states close to
+saturation, corroborating the observed femtosecond stimulated emission and
+optical gain in the wide near-infrared window.",1303.6902v2
+2013-03-27,Local Superfluidity at the Nanoscale,"We have performed quantum Monte Carlo simulations measuring the finite size
+and temperature superfluid response of helium-4 to the linear and rotational
+motion of the walls of a nanopore. Within the two-fluid model, the portion of
+the normal liquid dragged along with the boundaries is dependent on the type of
+motion and the resulting anisotropic superfluid density saturates far below
+unity at T=0.5 K. The origin of the saturation is uncovered by computing the
+spatial distribution of superfluidity, with only the core of the nanopore
+exhibiting any evidence of phase coherence. The superfluid core displays
+scaling behavior consistent with Luttinger liquid theory, thereby providing an
+experimental test for the emergence of a one dimensional quantum liquid.",1303.6954v2
+2013-04-09,Over saturation behavior of SiPMs at high photon exposure,"Several types of Silicon Photomultipliers were exposed to short pulsed laser
+light (~ 30 ps FWHM) with its intensity varying from single photon to well
+above the number of microcells of the device. We observed a significant
+deviation of the output of SiPMs from the expected behavior although such
+response curve is considered to be rather trivial. We also noticed that the
+output exceeds the maximum expected pulse height, which should be defined as
+the total number of pixels times the single photon pulse height. At the highest
+light intensity (~ 500 times the number of pixels) that we tested, the signal
+output reached up to twice the maximum theoretical pulse height, and still did
+not fully saturate.",1304.2493v3
+2013-04-17,The search for Nanobubbles by using specular and off-specular Neutron Reflectometry,"We apply specular and off-specular neutron reflection at the hydrophobic
+silicon/water interface to check for evidence of nanoscopic air bubbles whose
+presence is claimed after an ad hoc procedure of solvent exchange. Nanobubbles
+and/or a depletion layer at the hydrophobic/water interface have long been
+discussed and generated a plethora of controversial scientific results. By
+combining neutron reflectometry (NR), off-specular reflectometry (OSS) and
+grazing incidence small angle neutron scattering (GISANS), we studied the
+interface between hydrophobized silicon and heavy water before and after
+saturation with nitrogen gas. Our specular reflectometry results can be
+interpreted by assuming a sub-molecular sized depletion layer and the
+off-specular measurements show no change with nitrogen super saturated water.
+This picture is consistent with the assumption that, following the solvent
+exchange, no additional nanobubbles are introduced at significant
+concentrations (if present at all). Furthermore, we discuss the results, in
+terms of the maximum surface coverage of nanobubbles that could be present on
+the hydrophobic surface compatibly with the sensitivity limit of these
+techniques.",1304.4809v2
+2013-04-28,"Hidden Fermi Liquid, Scattering Rate Saturation and Nernst Effect: a DMFT Perspective","We investigate the transport properties of a correlated metal within
+dynamical mean field theory. Canonical Fermi liquid behavior emerges only below
+a very low temperature scale $T_{FL}$. Surprisingly the quasiparticle
+scattering rate follows a quadratic temperature dependence up to much higher
+temperatures and crosses over to saturated behavior around a temperature scale
+$T_{sat}$. We identify these quasiparticles as constituents of the hidden Fermi
+liquid. The non-Fermi liquid transport above $T_{FL}$, in particular the
+linear-in-$T$ resistivity, is shown to be a result of a strongly temperature
+dependent band dispersion. We derive simple expressions for resistivity, Hall
+angle, thermoelectric power and Nernst coefficient in terms of a temperature
+dependent renormalized band structure and the quasiparticle scattering rate. We
+discuss possible tests of the DMFT picture of transport using ac measurements.",1304.7486v1
+2013-05-30,Maximum Palinstrophy Growth in 2D Incompressible Flows,"In this study we investigate vortex structures which lead to the maximum
+possible growth of palinstrophy in two-dimensional incompressible flows on a
+periodic domain. The issue of palinstrophy growth is related to a broader
+research program focusing on extreme amplification of vorticity-related
+quantities which may signal singularity formation in different flow models.
+Such extreme vortex flows are found systematically via numerical solution of
+suitable variational optimization problems. We identify several families of
+maximizing solutions parameterized by their palinstrophy, palinstrophy and
+energy and palinstrophy and enstrophy. Evidence is shown that some of these
+families saturate estimates for the instantaneous rate of growth of
+palinstrophy obtained using rigorous methods of mathematical analysis, thereby
+demonstrating that this analysis is in fact sharp. In the limit of small
+palinstrophies the optimal vortex structures are found analytically, whereas
+for large palinstrophies they exhibit a self-similar multipolar structure. It
+is also shown that the time evolution obtained using the instantaneously
+optimal states with fixed energy and palinstrophy as the initial data saturates
+the upper bound for the maximum growth of palinstrophy in finite time. Possible
+implications of this finding for the questions concerning extreme behavior of
+flows are discussed.",1305.7259v2
+2013-05-31,Drop-port study of microresonator frequency combs: power transfer and time-domain characterization,"We use a drop-port geometry to study power transfer in silicon nitride
+on-chip microresonator frequency comb generators. In sharp contrast with the
+traditional transmission geometry, we observe smooth output spectra with
+comparable powers in the pump and adjacent comb lines. An observation of
+saturation in the drop-port output power is explained semi-empirically by
+introducing pump saturation into a coupling of modes model. Autocorrelation
+measurements are performed on the drop-port output, without the need to filter
+out or suppress the strong pump line as is necessary in thru-port experiments.
+Passively mode-locked pulses are observed with a normal dispersion microcavity.",1305.7420v2
+2013-06-10,"Transverse Momentum of Protons, Pions and Kaons in High Multiplicity pp and pA Collisions: Evidence for the Color Glass Condensate?","The CMS experiment at the Large Hadron Collider has recently presented data
+on the average transverse momentum of protons, kaons and pions as a function of
+particle multiplicity. We relate the particle multiplicity to saturation
+momentum using recently published computations of the interaction radius
+determined from the theory of the Color Glass Condensate. We show that the pp
+and the pA experimental data scale in terms of these saturation momenta.
+Computing transverse momentum spectra for identified particles using
+Boltzmann-type distributions and relating different associated multiplicities
+using geometric scaling, these simple distributions reproduce the observed
+dependence of the mean transverse momentum on particle multiplicities seen in
+both pp and pA interactions for pions to good accuracy, and to fair agreement
+for protons and kaons.",1306.2350v1
+2013-06-20,Dynamical entanglement entropy with angular momentum and U(1) charge,"We consider time-dependent entanglement entropy (EE) for a 1+1 dimensional
+CFT in the presence of angular momentum and U(1) charge. The EE saturates,
+irrespective of the initial state, to the grand canonical entropy after a time
+large compared with the length of the entangling interval. We reproduce the CFT
+results from an AdS dual consisting of a spinning BTZ black hole and a flat
+U(1) connection. The apparent discrepancy that the holographic EE does not a
+priori depend on the U(1) charge while the CFT EE does, is resolved by the
+charge-dependent shift between the bulk and boundary stress tensors. We show
+that for small entangling intervals, the entanglement entropy obeys the first
+law of thermodynamics, as conjectured recently. The saturation of the EE in the
+field theory is shown to follow from a version of quantum ergodicity; the
+derivation indicates that it should hold for conformal as well as massive
+theories in any number of dimensions.",1306.4974v2
+2013-06-30,IP-Sat: Impact-Parameter dependent Saturation model; revised,"In this talk, we present a global analysis of available small-x data on
+inclusive DIS and exclusive diffractive processes, including the latest data
+from the combined HERA analysis on reduced cross sections within the
+Impact-Parameter dependent Saturation (IP-Sat) Model. The impact-parameter
+dependence of dipole amplitude is crucial in order to have a unified
+description of both inclusive and exclusive diffractive processes. With the
+parameters of model fixed via a fit to the high-precision reduced
+cross-section, we compare model predictions to data for the structure
+functions, the longitudinal structure function, the charm structure function,
+exclusive vector mesons production and Deeply Virtual Compton Scattering
+(DVCS). Excellent agreement is obtained for the processes considered at small x
+in a wide range of Q^2.",1307.0165v1
+2013-07-03,A new mechanism for saturating unstable r-modes in neutron stars,"We consider a new mechanism for damping the oscillations of a mature neutron
+star. The new dissipation channel arises if superfluid vortices are forced to
+cut through superconducting fluxtubes. This mechanism is interesting because
+the oscillation modes need to exceed a critical amplitude in order for it to
+operate. Once it acts the effect is very strong (and nonlinear) leading to
+efficient damping. The upshot of this is that modes are unlikely to ever evolve
+far beyond the critical amplitude. We consider the effect of this new
+dissipation channel on the r-modes, that may be driven unstable by the emission
+of gravitational waves. Our estimates show that the fluxtube cutting leads to a
+saturation threshold for the instability that can be smaller than that of other
+proposed mechanisms. This suggests that the idea may be of direct astrophysical
+relevance.",1307.0985v1
+2013-07-10,Electric dipole response of 208Pb from proton inelastic scattering: constraints on neutron skin thickness and symmetry energy,"The electric dipole (E1) response of 208Pb has been precisely determined by
+measuring Coulomb excitation induced by proton scattering at very forward
+angles. The electric dipole polarizability, defined as inverse energy-weighted
+sum rule of the E1 strength, has been extracted as 20.1+-0.6 fm^3. The data can
+be used to constrain the neutron skin thickness of 208Pb to
+0.168(+-0.009)_expt(+-0.013)_theo(+-0.021)_est fm, where the subscript ""expt""
+refers to the experimental uncertainty, ""theor"" to the theoretical confidence
+band and ""est"" to the uncertainty associated with the estimation of the
+symmetry energy at the saturation density. In addition, a constraint band has
+been extracted in the plane of the symmetry energy (J) and its slope parameter
+(L) at the saturation density.",1307.2706v2
+2013-07-26,Global Attractivity and Extinction for Lotka-Volterra systems with infinite delay and feedback controls,"The paper deals with a multiple species Lotka-Volterra model with infinite
+distributed delays and feedback controls, for which we assume a weak form of
+diagonal dominance of the instantaneous negative intra-specific terms over the
+infinite delay effect in both the population variables and controls. General
+sufficient conditions for the existence and attractivity of a saturated
+equilibrium are established. When the saturated equilibrium is on the boundary
+of $\R^n_+$, sharper criteria for the extinction of all or part of the
+populations are given. While the literature usually treats the case of
+competitive systems only, here no restrictions on the signs of the intra- and
+inter-specific delayed terms are imposed. Moreover, our technique does not
+require the construction of Lyapunov functionals.",1307.7039v1
+2013-08-02,Three jet production and gluon saturation effects in p-p and p-Pb collisions within high-energy factorization,"We analyze three jet production in the central-forward and forward rapidity
+regions in proton-proton and proton-lead collisions at LHC energies. Our
+calculation relies on high-energy factorization with a single off-shell gluon
+obeying small x evolution equation which includes saturation. The calculations
+are made using two independent Monte Carlo codes implementing tree-level gauge
+invariant off-shell matrix elements. We calculate differential cross sections
+for azimuthal decorrelations and unbalanced jet transverse momenta and discuss
+them in the context of differences in the evolution of the unintegrated gluon
+densities.",1308.0452v3
+2013-08-06,Heavy quark pair production in high energy pA collisions: Open heavy flavors,"We study open heavy flavor meson production in proton-nucleus (pA) collisions
+at RHIC and LHC energies within the Color Glass Condensate framework. We use
+the unintegrated gluon distribution at small Bjorken's x in the proton obtained
+by solving the Balitsky-Kovchegov equation with running coupling correction and
+constrained by global fitting of HERA data. We change the initial saturation
+scale of the gluon distribution for the heavy nucleus. The gluon distribution
+with McLerran-Venugopalan model initial condition is also used for comparison.
+We present transverse momentum spectra of single D and B productions in pA
+collisions, and the so-called nuclear modification factor. The azimuthal angle
+correlation of open heavy flavor meson pair is also computed to study the
+modification due to the gluon saturation in the heavy nucleus at the LHC.",1308.1258v1
+2013-09-03,The plasma oscillations in a two-dimensional electron-hole liquid under influence Rashba spin-orbit coupling,"The plasma oscillations of the two-dimensional electron-hole system in the
+presence of a Rashba spin-orbit coupling are studied. Only the intra-Landau
+level excitations are taken into account when the electrons and holes are
+situated on their lowest Landau levels, the filling factor $v^{2}$ being less
+than 1. The ground state of the two-dimensional electron-hole system is
+supposed to be the electron-hole liquid. The dispersion relations for the
+optical and acoustical plasmon modes were obtained. The acoustical plasmon
+branch has a linear dispersion law in the range of small wave vectors and
+monotonically increases with saturation at higher values of wave vectors. The
+optical plasmon branch has a quadratic dependence in the range of long
+wavelength and a monotonic increasing with saturation as in the case of
+acoustical branch.",1309.0716v1
+2013-09-05,Quantum Joule-Thomson Effect in a Saturated Homogeneous Bose Gas,"We study the thermodynamics of Bose-Einstein condensation in a weakly
+interacting quasi-homogeneous atomic gas, prepared in an optical-box trap. We
+characterise the critical point for condensation and observe saturation of the
+thermal component in a partially condensed cloud, in agreement with Einstein's
+textbook picture of a purely statistical phase transition. Finally, we observe
+the quantum Joule-Thomson effect, namely isoenthalpic cooling of an
+(essentially) ideal gas. In our experiments this cooling occurs spontaneously,
+due to energy-independent collisions with the background gas in the vacuum
+chamber. We extract a Joule-Thomson coefficient $\mu_{\rm JT} > 10^9$ K/bar,
+about ten orders of magnitude larger than observed in classical gases.",1309.1441v3
+2013-09-10,Spectral Sum Rules and Magneto-Roton as Emergent Graviton in Fractional Quantum Hall Effect,"We consider gapped fractional quantum Hall states on the lowest Landau level
+when the Coulomb energy is much smaller than the cyclotron energy. We introduce
+two spectral densities, \rho_T(\omega) and \bar \rho_T(\omega), which are
+proportional to the probabilities of absorption of circularly polarized
+gravitons by the quantum Hall system. We prove three sum rules relating these
+spectral densities with the shift S, the q^4 coefficient of the static
+structure factor S_4, and the high-frequency shear modulus of the ground state
+\mu_\infty, which is precisely defined. We confirm an inequality, first
+suggested by Haldane, that S_4 is bounded from below by |S-1|/8. The Laughlin
+wavefunction saturates this bound, which we argue to imply that systems with
+ground state wavefunctions close to Laughlin's absorb gravitons of
+predominantly one circular polarization. We consider a nonlinear model where
+the sum rules are saturated by a single magneto-roton mode. In this model, the
+magneto-roton arises from the mixing between oscillations of an internal metric
+and the hydrodynamic motion. Implications for experiments are briefly
+discussed.",1309.2638v1
+2013-09-13,Non-linear evolution of unintegrated gluon density at large values of coupling constant,"We propose an evolution equation for unintegrated gluon densities that is
+valid for large values of the QCD coupling constant $\bar{\alpha} _s$. Our
+approach is based on the linear resummation model introduced by Sta\'{s}to. We
+generalize the model including a non-linear term in the diffusive regime. The
+validity of the diffusive evolution at strong coupling is supported by the
+AdS/CFT consideration, as well as perturbative arguments. We solve the
+evolution equation numerically and extract the saturation scale, which we
+compare with the weak coupling counterpart.",1309.3450v3
+2013-09-23,Saturation of black hole lasers in Bose-Einstein condensates,"To obtain the end-point evolution of the so-called black hole laser
+instability, we study the set of stationary solutions of the Gross-Pitaevskii
+equation for piecewise constant potentials which admit a homogeneous solution
+with a supersonic flow in the central region between two discontinuities. When
+the distance between them is larger than a critical value, we recover that the
+homogeneous solution is unstable, and we identify the lowest energy state. We
+show that it can be viewed as determining the saturated value of the first
+(node-less) complex frequency mode which drives the instability. We also
+classify the set of stationary solutions and establish their relation both with
+the set of complex frequency modes and with known soliton solutions. Finally,
+we adopt a procedure \`a la Pitaevski-Baym-Pethick to construct the effective
+functional which governs the transition from the homogeneous to non-homogeneous
+solutions.",1309.5869v2
+2013-09-27,Planck's uncertainty principle and the saturation of Lorentz boosts by Planckian black holes,"A basic inconsistency arises when the Theory of Special Relativity meets with
+quantum phenomena at the Planck scale. Specifically, the Planck length is
+Lorentz invariant and should not be affected by a Lorentz boost. We argue that
+Planckian relativity must necessarily involve the effect of black hole
+formation. Recent proposals for resolving the noted inconsistency seem
+unsatisfactory in that they ignore the crucial role of gravity in the
+saturation of Lorentz boosts. Furthermore, an invariant length at he Planck
+scale amounts to a universal quantum of resolution in the fabric of spacetime.
+We argue, therefore, that the universal Planck length requires an extension of
+the Uncertainty Principle as well. Thus, the noted inconsistency lies at the
+core of Quantum Gravity. In this essay we reflect on a possible resolution of
+these outstanding problems.",1309.7186v1
+2013-10-08,"Ultrafast and widely tuneable vertical-external-cavity surface-emitting laser, mode-locked by a graphene-integrated distributed Bragg reflector","We report a versatile and cost-effective way of controlling the unsaturated
+loss, modulation depth and saturation fluence of graphene-based saturable
+absorbers (GSAs), by changing the thickness of a spacer between SLG and a
+high-reflection mirror. This allows us to modulate the electric field intensity
+enhancement at the GSA from 0 up to 400%, due to the interference of incident
+and reflected light at the mirror. The unsaturated loss of the
+SLG-mirror-assembly can be reduced to$\sim$0. We use this to mode-lock a VECSEL
+from 935 to 981nm. This approach can be applied to integrate SLG into various
+optical components, such as output coupler mirrors, dispersive mirrors,
+dielectric coatings on gain materials. Conversely, it can also be used to
+increase absorption (up to 10%) in various graphene based photonics and
+optoelectronics devices, such as photodetectors.",1310.2132v1
+2013-10-11,Fluid dynamics with saturated minijet initial conditions in ultrarelativistic heavy-ion collisions,"Using next-to-leading order perturbative QCD and a conjecture of saturation
+to suppress the production of low-energy partons, we calculate the initial
+energy densities and formation times for the dissipative fluid dynamical
+evolution of the quark-gluon plasma produced in ultrarelativistic heavy-ion
+collisions. We identify the framework uncertainties and demonstrate the
+predictive power of the approach by a good global agreement with the measured
+centrality dependence of charged particle multiplicities, transverse momentum
+spectra and elliptic flow simultaneously for the Pb+Pb collisions at the LHC
+and Au+Au at RHIC. In particular, the shear viscosity in the different phases
+of QCD matter is constrained in this new framework simultaneously by all these
+data.",1310.3105v1
+2013-10-17,Numerical Modeling of Nanoparticles Transport with Two-Phase Flow in Porous Media Using Iterative Implicit Method,"In this paper, we introduce a mathematical model to describe the
+nanoparticles transport carried by a two-phase flow in a porous medium
+including gravity, capillary forces and Brownian diffusion. Nonlinear iterative
+IMPES scheme is used to solve the flow equation, and saturation and pressure
+are calculated at the current iteration step and then the transport equation is
+soved implicitly. Therefore, once the nanoparticles concentration is computed,
+the two equations of volume of the nanoparticles available on the pore surfaces
+and the volume of the nanoparticles entrapped in pore throats are solved
+implicitly. The porosity and the permeability variations are updated at each
+time step after each iteration loop. Two numerical examples, namely, regular
+heterogeneous permeability and random permeability are considered. We monitor
+the changing of the fluid and solid properties due to adding the nanoparticles.
+Variation of water saturation, water pressure, nanoparticles concentration and
+porosity are presented graphically.",1310.4769v1
+2013-10-18,Sivers Function in the Quasi-Classical Approximation,"We calculate the Sivers function in semi-inclusive deep inelastic scattering
+(SIDIS) and in the Drell-Yan process (DY) by employing the quasi-classical
+Glauber-Mueller/ McLerran-Venugopalan approximation. Modeling the hadron as a
+large ""nucleus"" with non-zero orbital angular momentum (OAM), we find that its
+Sivers function receives two dominant contributions: one contribution is due to
+the OAM, while another one is due to the local Sivers function density in the
+nucleus. While the latter mechanism, being due to the ""lensing"" interactions,
+dominates at large transverse momentum of the produced hadron in SIDIS or of
+the di-lepton pair in DY, the former (OAM) mechanism is leading in saturation
+power counting and dominates when the above transverse momenta become of the
+order of the saturation scale. We show that the OAM channel allows for a
+particularly simple and intuitive interpretation of the celebrated sign flip
+between the Sivers functions in SIDIS and DY.",1310.5028v2
+2013-10-21,A family of steady two-phase generalized Forchheimer flows and their linear stability analysis,"We model multi-dimensional two-phase flows of incompressible fluids in porous
+media using generalized Forchheimer equations and the capillary pressure.
+Firstly, we find a family of steady state solutions whose saturation and
+pressure are radially symmetric and velocities are rotation-invariant. Their
+properties are investigated based on relations between the capillary pressure,
+each phase's relative permeability and Forchheimer polynomial. Secondly, we
+analyze the linear stability of those steady states.
+  The linearized system is derived and reduced to a parabolic equation for the
+saturation. This equation has a special structure depending on the steady
+states which we exploit to prove two new forms of the lemma of growth of
+Landis-type in both bounded and unbounded domains. Using these lemmas,
+qualitative properties of the solution of the linearized equation are studied
+in details. In bounded domains, we show that the solution decays exponentially
+in time. In unbounded domains, in addition to their stability, the solution
+decays to zero as the spatial variables tend to infinity. The Bernstein",1310.5723v1
+2013-10-22,Experimental effects on dynamics and thermodynamics in nuclear reactions on the symmetry energy as seen by the CHIMERA 4$π$ detector,"Heavy ion collisions have been widely used in the last decade to constraint
+the parameterizations of the symmetry energy term of nuclear equation of state
+(EOS) for asymmetric nuclear matter as a function of baryonic density. In the
+Fermi energy domain one is faced with variations of the density within a narrow
+range of values around the saturation density $\rho_0$=0.16 fm$^{-3}$ down
+towards sub-saturation densities. The experimental observables which are
+sensitive to the symmetry energy are constructed starting from the detected
+light particles, clusters and heavy fragments that, in heavy ion collisions,
+are generally produced by different emission mechanisms at different stages and
+time scales of the reaction. In this review the effects of dynamics and
+thermodynamics on the symmetry energy in nuclear reactions are discussed and
+characterized using an overview of the data taken so far with the CHIMERA
+multi-detector array.",1310.5836v1
+2013-10-28,Obtaining localization properties efficiently using the Kubo-Greenwood formalism,"We establish, through numerical calculations and comparisons with a recursive
+Green's function based implementation of the Landauer-B\""uttiker formalism, an
+efficient method for studying Anderson localization in quasi-one-dimensional
+and two-dimensional systems using the Kubo-Greenwood formalism. Although the
+recursive Green's function method can be used to obtain the localization length
+of a mesoscopic conductor, it is numerically very expensive for systems that
+contain a large number of atoms transverse to the transport direction. On the
+other hand, linear-scaling has been achieved with the Kubo-Greenwood method,
+enabling the study of effectively two-dimensional systems. While the
+propagating length of the charge carriers will eventually saturate to a finite
+value in the localized regime, the conductances given by the Kubo-Greenwood
+method and the recursive Green's function method agree before the saturation.
+The converged value of the propagating length is found to be directly
+proportional to the localization length obtained from the exponential decay of
+the conductance.",1310.7518v2
+2013-11-05,Exciton-exciton annihilation in MoSe2 monolayers,"We investigate the excitonic dynamics in MoSe2 monolayer and bulk samples by
+femtosecond transient absorption microscopy. Excitons are resonantly injected
+by a 750-nm and 100-fs laser pulse, and are detected by a probe pulse tuned in
+the range of 790 - 820 nm. We observe a strong density-dependent initial decay
+of the exciton population in monolayers, which can be well described by the
+exciton-exciton annihilation. Such a feature is not observed in the bulk under
+comparable conditions. We also observe the saturated absorption induced by
+exciton phase-space filling in both monolayers and the bulk, which indicates
+their potential applications as saturable absorbers.",1311.1079v1
+2013-11-06,"Steering, incompatibility, and Bell inequality violations in a class of probabilistic theories","We show that connections between a degree of incompatibility of pairs of
+observables and the strength of violations of Bell's inequality found in recent
+investigations can be extended to a general class of probabilistic physical
+models. It turns out that the property of universal uniform steering is
+sufficient for the saturation of a generalised Tsirelson bound, corresponding
+to maximal violations of Bell's inequality. It is also found that a limited
+form of steering is still available and sufficient for such saturation in some
+state spaces where universal uniform steering is not given. The techniques
+developed here are applied to the class of regular polygon state spaces, giving
+a strengthening of known results. However, we also find indications that the
+link between incompatibility and Bell violation may be more complex than
+originally envisaged.",1311.1462v2
+2013-11-06,Charm production in double parton scattering at the LHC,"We calculate $c\bar{c}c\bar{c}$ and $b\bar{b}b\bar{b}$ production cross
+section in Double Parton Scattering (DPS) processes at the energies of LHC. In
+our calculation we include saturation effects in the gluon distribution. For
+charm production, our results confirm the prediction of a previous work in
+which saturation effects were neglected, namely that at the energies of LHC
+charm production in DPS processes becomes comparable with charm production in
+SPS. We also estimate the production of $c\bar{c}b\bar{b}$ in DPS. Our results
+indicate that at $\sqrt{s}=14$ TeV half of the total amount of bottom produced
+in proton-proton collisions comes from this process.",1311.2473v1
+2013-11-14,Nuclear Entalpies,"In a compressed Nuclear Matter (NM) an increasing pressure between the
+nucleons starts to increase the ratio of a nucleon Fermi to average single
+particle energy and in accordance with the Hugenholtz-van Hove theorem the
+longitudinal Momentum Sum Rule (MSR) is broken in a Relativistic Mean Field
+(RMF) approach. We propose to benefit from the concept of enthalpy in order to
+show how to fulfill the MSR above a saturation density with pressure
+corrections. As a result a nucleon mass can decrease with density, making the
+Equation of State (EoS) softer. The course of the EoS in our modified RMF model
+is close to a semi-empirical estimate and to results obtained from extensive
+DBHF calculations with a Bonn A potential, which produce the EoS stiff enough
+to describe neutron star properties (mass-radius constraint), especially the
+most massive known neutron star. The presented model has proper saturation
+properties, including good values of a compressibility and a spin-orbit term.",1311.3591v2
+2013-11-25,Photoassociation of ultracold LiRb* molecules: observation of high efficiency and unitarity-limited rate saturation,"We report the production of ultracold heteronuclear 7Li85Rb molecules in
+excited electronic states by photoassociation (PA) of ultracold 7Li and 85Rb
+atoms. PA is performed in a dual-species 7Li-85Rb magneto-optical trap (MOT)
+and the PA resonances are detected using trap loss spectroscopy. We identify
+several strong PA resonances below the Li (2s 2S1/2) + Rb (5p 2P3/2) asymptote
+and experimentally determine the long range C6 dispersion coefficients. We find
+a molecule formation rate (P_LiRb) of 3.5x10^7 s^-1 and a PA rate coefficient
+(K_PA) of 1.3x10^-10 cm^3/s, the highest among heteronuclear bi-alkali
+molecules. At large PA laser intensity, we observe the saturation of the PA
+rate coefficient (K_PA) close to the theoretical value at the unitarity limit.",1311.6297v2
+2013-11-26,Coherent chirped pulse laser network in Mickelson phase conjugating configuration,"The mechanisms of nonlinear phase-locking of a large fiber amplifier array
+are analyzed. It is shown that Michelson phase conjugating configuration with
+double passage through array of fiber amplifiers have the definite advantages
+compared to one-way fiber array coupled in a Mach-Zehnder configuration.
+Regardless to amount of synchronized fiber amplifiers Michelson
+phase-conjugating interferometer is expected to do a perfect compensation of
+the phase-piston errors and collimation of backwardly amplified fiber beams on
+entrance/output beamsplitter. In both configurations the nonlinear
+transformation of the stretched pulse envelope due to gain saturation is
+capable to randomize the position of chirp inside envelope thus it may reduce
+the visibility of interference pattern at output beamsplitter. A certain
+advantages are inherent to the $sech$-form temporal envelope because of
+exponential precursor and self-similar propagation in gain medium. The Gaussian
+envelope is significantly compressed in a deep gain saturation regime and
+frequency chirp position inside pulse envelope is more deformed.",1311.6703v4
+2013-11-27,Analyzing the Dual Space of the Saturated Ideal of a Regular Set and the Local Multiplicities of its Zeros,"In this paper, we are concerned with the problem of counting the
+multiplicities of a zero-dimensional regular set's zeros. We generalize the
+squarefree decomposition of univariate polynomials to the so-called pseudo
+squarefree decomposition of multivariate polynomials, and then propose an
+algorithm for decomposing a regular set into a finite number of simple sets.
+From the output of this algorithm, the multiplicities of zeros could be
+directly read out, and the real solution isolation with multiplicity can also
+be easily produced. As a main theoretical result of this paper, we analyze the
+structure of dual space of the saturated ideal generated by a simple set as
+well as a regular set. Experiments with a preliminary implementation show the
+efficiency of our method.",1311.6897v2
+2013-12-14,Analysis of a class of degenerate parabolic equations with saturation mechanisms,"We analyze a family of degenerate parabolic equations with linear growth
+Lagrangian having the form $u_t=\div (\varphi(u)\psi(\nabla u/u))$. Here
+$|\psi|\le 1$ and saturates at infinity. We present a simple and natural set of
+assumptions on the functions $\psi,\varphi$, under which: 1) these equations
+fall in the framework provided by \cite{ACMEllipticFLDE, ACMMRelat} and hence
+they are well posed, 2) we can ensure finite propagation speed for these
+models, 3) a Rankine--Hugoniot analysis on traveling fronts is also performed.
+On the particular case of $\varphi(u)=u$ we get more detailed information on
+the spreading rate of compactly supported solutions and some interesting
+connections with optimal mass transportation theory.",1312.4034v5
+2013-12-22,A General Criterion for Liquefaction in Granular Layers with Heterogeneous Pore Pressure,"Fluid-saturated granular and porous layers can undergo liquefaction and lose
+their shear resistance when subjected to shear forcing. In geosystems, such a
+process can lead to severe natural hazards of soil liquefaction, accelerating
+slope failure, and large earthquakes. Terzaghi's principle of effective stress
+predicts that liquefaction occurs when the pore pressure within the layer
+becomes equal to the applied normal stress on the layer. However, under dynamic
+loading and when the internal permeability is relatively small the pore
+pressure is spatially heterogeneous and it is not clear what measurement of
+pore pressure should be used in Terzaghi's principle. Here, we show
+theoretically and demonstrate using numerical simulations a general criterion
+for liquefaction that applies also for the cases in which the pore pressure is
+spatially heterogeneous. The general criterion demands that the average pore
+pressure along a continuous surface within the fluid-saturated granular or
+porous layer is equal to the applied normal stress.",1312.6422v1
+2014-01-09,The equation of state and symmetry energy of low density nuclear matter,"The symmetry energy of nuclear matter is a fundamental ingredient in the
+investigation of exotic nuclei, heavy-ion collisions and astrophysical
+phenomena. A recently developed quantum statistical (QS) approach that takes
+the formation of clusters into account predicts low density symmetry energies
+far above the usually quoted mean field limits. A consistent description of the
+symmetry energy has been developed that joins the correct low-density limit
+with values calculated from quasi-particle approaches valid near the saturation
+density. The results are confronted with experimental values for free symmetry
+energies and internal symmetry energies, determined at sub-saturation densities
+and temperatures below 10 MeV using data from heavy-ion collisions. There is
+very good agreement between the experimental symmetry energy values and those
+calculated in the QS approach",1401.2074v1
+2014-01-10,GaAs Quantum Dot Thermometry Using Direct Transport and Charge Sensing,"We present measurements of the electron temperature using gate defined
+quantum dots formed in a GaAs 2D electron gas in both direct transport and
+charge sensing mode. Decent agreement with the refrigerator temperature was
+observed over a broad range of temperatures down to 10 mK. Upon cooling nuclear
+demagnetization stages integrated into the sample wires below 1 mK, the device
+electron temperature saturates, remaining close to 10 mK. The extreme
+sensitivity of the thermometer to its environment as well as electronic noise
+complicates temperature measurements but could potentially provide further
+insight into the device characteristics. We discuss thermal coupling
+mechanisms, address possible reasons for the temperature saturation and
+delineate the prospects of further reducing the device electron temperature.",1401.2330v1
+2014-01-20,All Superparticles are BPS,"The generic action for an N-extended superparticle in D-dimensional Minkowski
+spacetime is shown to have ""hidden"" supersymmetries (related by ""dualities"" to
+the manifest supersymmetries) such that the full supersymmetry algebra is
+BPS-saturated; the exceptions (which include, trivially, the massless case) are
+those for which the manifest supersymmetry algebra is already BPS-saturated.
+Moreover, it is shown that any ""non-BPS"" superparticle action is a gauge-fixed
+version of the ""BPS"" superparticle action for which all supersymmetries are
+manifest. An example is the N=1 massive D=10 superparticle, which actually has
+N=2 supersymmetry and is equivalent to the action for a D0-brane of IIA
+superstring theory.",1401.5116v2
+2014-01-23,Nonlinear Photoluminescence Properties of Trions in Hole-doped Single-walled Carbon Nanotubes,"We studied the excitation density dependence of photoluminescence (PL)
+spectra of excitons and trions (charged excitons) in hole-doped single-walled
+carbon nanotubes. We found that the PL intensity of trions exhibited a strong
+nonlinear saturation behavior as the excitation density increased, whereas that
+of excitons exhibited a weak sublinear behavior. The strong PL saturation of
+trions is attributed to depletion of doped holes that are captured by excitons
+in the formation processes. Moreover, the effective radiative lifetime of a
+trion was evaluated to be approximately 20 ns.",1401.5873v1
+2014-01-27,On Efficiency and Validity of Previous Homeplug MAC Performance Analysis,"The Medium Access Control protocol of Power Line Communication networks
+(defined in Homeplug and IEEE 1901 standards) has received relatively modest
+attention from the research community. As a consequence, there is only one
+analytic model that complies with the standardised MAC procedures and considers
+unsaturated conditions. We identify two important limitations of the existing
+analytic model: high computational expense and predicted results just prior to
+the predicted saturation point do not correspond to long-term network
+performance. In this work, we present a simplification of the previously
+defined analytic model of Homeplug MAC able to substantially reduce its
+complexity and demonstrate that the previous performance results just before
+predicted saturation correspond to a transitory phase. We determine that the
+causes of previous misprediction are common analytical assumptions and the
+potential occurrence of a transitory phase, that we show to be of extremely
+long duration under certain circumstances. We also provide techniques, both
+analytical and experimental, to correctly predict long-term behaviour and
+analyse the effect of specific Homeplug/IEEE 1901 features on the magnitude of
+misprediction errors.",1401.6803v2
+2014-01-27,Elliptic Flow and Shear Viscosity of the Shattered Color Glass Condensate,"In this talk, we report on our results about the computation of the elliptic
+flow of the quark-gluon-plasma produced in relativistic heavy ion collisions,
+simulating the expansion of the fireball by solving the relativistic Boltzmann
+equation for the parton distribution function tuned at a fixed shear viscosity
+to entropy density ratio $\eta/s$. We emphasize the role of saturation in the
+initial gluon spectrum modelling the shattering of the color glass condensate,
+causing the initial distribution to be out of equilibrium. We find that the
+saturation reduces the efficiency in building-up the elliptic flow, even if the
+thermalization process is quite fast $\tau_{therm} \approx 0.8 \,\rm fm/c$. and
+the pressure isotropization even faster $\tau_{isotr} \approx 0.3 \,\rm fm/c$.
+The impact of the initial non-equilibrium manifests for non-central collisions
+and can modify the estimate of the viscosity respect to the assumption of full
+thermalization in $p_T$-space.",1401.6903v1
+2014-01-28,A Two-Level Variant of Additive Schwarz Preconditioning for Use in Reservoir Simulation,"The computation time for reservoir simulation is dominated by the linear
+solver. The sets of linear equations which arise in reservoir simulation have
+two distinctive features: the problems are usually highly anisotropic, with a
+dominant vertical flow direction, and the commonly used fully implicit method
+requires a simultaneous solution for pressure and saturation or molar
+concentration variables. These variables behave quite differently, with the
+pressure feeling long-range effects while the saturations vary locally. In this
+paper we review preconditioned iterative methods used for solving the linear
+system equations in reservoir simulation and their parallelisation. We then
+propose a variant of the classical additive Schwarz preconditioner designed to
+achieve better results on a large number of processors and discuss some
+directions for future research.",1401.7227v3
+2014-02-07,"Qualitative behavior for flux-saturated mechanisms: Traveling waves, waiting time and smoothing effects","This paper is devoted to the analysis of qualitative properties of
+flux-saturated type operators in dimension one. Specifically, we study
+regularity properties and smoothing effects, discontinuous interfaces, the
+existence of traveling wave profiles, sub- and super-solutions and waiting time
+features. The aim of the paper is to better understand these kind of phenomena
+throughout two prototypic operators: The relativistic heat equation and the
+porous media flux-limited equation. As an important consequence of our results
+we deduce that solutions to the one-dimensional relativistic heat equation
+become smooth inside their support on the long time run.",1402.1679v2
+2014-02-18,Constraints on the skewness coefficient of symmetric nuclear matter within the nonlinear relativistic mean field model,"Within the nonlinear relativistic mean field (NL-RMF) model, we show that
+both the pressure of symmetric nuclear matter at supra-saturation densities and
+the maximum mass of neutron stars are sensitive to the skewness coefficient
+$J_0$ of symmetric nuclear matter. Using experimental constraints on the
+pressure of symmetric nuclear matter at supra-saturation densities from flow
+data in heavy ion collisions and the astrophysical observation of a large mass
+neutron star PSR J0348+0432, with the former favoring a smaller $J_0$ while the
+latter a larger $J_0$, we extract a constraint of $-494 \mathrm{MeV}\leq
+J_0\leq -10 \mathrm{MeV}$ based on the NL-RMF model. This constraint is
+compared with the results obtained in other analyses.",1402.4242v2
+2014-03-08,"Interactions of Airy beams, nonlinear accelerating beams, and induced solitons in Kerr and saturable nonlinear media","We investigate numerically interactions between two in-phase or out-of-phase
+Airy beams and nonlinear accelerating beams in Kerr and saturable nonlinear
+media in one transverse dimension. We discuss different cases in which the
+beams with different intensities are launched into the medium, but accelerate
+in opposite directions. Since both the Airy beams and nonlinear accelerating
+beams possess infinite oscillating tails, we discuss interactions between
+truncated beams, with finite energies. During interactions we see solitons and
+soliton pairs generated that are not accelerating. In general, the higher the
+intensities of interacting beams, the easier to form solitons; when the
+intensities are small enough, no solitons are generated. Upon adjusting the
+interval between the launched beams, their interaction exhibits different
+properties. If the interval is large relative to the width of the first lobes,
+the generated soliton pairs just propagate individually and do not interact
+much. However, if the interval is comparable to the widths of the maximum
+lobes, the pairs strongly interact and display varied behavior.",1403.1952v1
+2014-03-25,Coexistence of fast photodarkening and slow photobleaching in Ge19As21Se60 thin films,"We experimentally demonstrate the coexistence of two opposite photo-effects,
+viz. fast photodarkening (PD) and slow photobleaching (PB) in Ge19As21Se60 thin
+films, when illuminated with a laser of wavelength 671nm, PD appears to begin
+instantaneously upon light illumination and saturates in tens of seconds. By
+comparison, PB is a slower process that starts only after PD has saturated.
+Although we could observe the coexistence of PD/PB even at moderate, one order
+of magnitude lower intensity of 0.2 W/cm2, the kinetics of transformation is
+significantly slowed down. However, both PD and PB follow stretched exponetial
+dependence on time. Modeling of overall change as a linear sum of two
+contributions suggests that the changes in As and Ge parts of glass network
+respond to light indepndent of each other.",1403.6359v1
+2014-03-25,Multipacting saturation in parallel plate and micro-pulse electron gun,"A novel parallel plate model is proposed that divided the electron cloud into
+three parts at saturation, and it is studied in detail using both an analytical
+approach and PIC (Particle In Cell) code simulations. As one part of the
+electron cloud, ribbons modes are suggested by tracking the trajectory of
+individual particle, and the aim of this mode form is to simplify the progress
+of multipacting effect in the parallel plate so as to be eliminated by
+optimizing RF parameters. The micro-pulse electron gun (MPG) has demonstrated
+the potential to address the need for high peak and average current electron
+beams, hence studying the multipacting in MPG is essential. On the basis of
+multipacting studying in the parallel plate, it is clear that increasing the
+cavity voltage is of interest in yielding high quality beams in the gun.",1403.6360v2
+2014-03-31,Penetration depth scaling for impact into wet granular packings,"We present experimental measurements of penetration depths for the impact of
+spheres into wetted granular media. We observe that the penetration depth in
+the liquid saturated case scales with projectile density, size, and drop height
+in a fashion consistent with the scaling observed in the dry case, but that
+penetration depths into saturated packings tend to be smaller. This result
+suggests that, for the range of impact energies observed, the stopping force is
+set by static contact forces between grains within the bed, and that the
+presence of liquid serves, primarily, to enhance these contact forces. The
+enhancement to the stopping force has a complicated dependence on liquid
+fraction, accompanied by a change in the drop-height dependence, that must be
+the consequence of accompanying changes in the conformation of the liquid phase
+in the interstices.",1403.8124v4
+2014-04-01,The Search for Gluon Saturation in pA Collisions,"In this talk, I reviewed the recent theoretical progress towards the
+exploration of the gluon saturation phenomenon in $pA$ collisions at both RHIC
+and the LHC. Two important pillars of this exploration are the single inclusive
+forward hadron productions and forward dihadron correlations, which have both
+been computed up to one-loop order within the small-$x$ factorization
+formalism. Furthermore, detailed numerical study for the single inclusive
+hadron production at next-to-leading order provides us good description of the
+low transverse momentum data measured in $dAu$ collisions at RHIC with
+significantly reduced uncertainty. In addition, the one-loop calculation for
+dihadron productions in $pA$ collisions shows that there is a new type of large
+logarithm, which is known as the Sudakov factor, arising in the back-to-back
+correlation limit.",1404.0179v1
+2014-04-08,Fingerprints of Inelastic Transport at the Surface of the Topological Insulator Bi2Se3: Role of Electron-Phonon Coupling,"We report on electric-field and temperature dependent transport measurements
+in exfoliated thin crystals of Bi$_{2}$Se$_{3}$ topological insulator. At low
+temperatures ($< 50$ K) and when the chemical potential lies inside the bulk
+gap, the crystal resistivity is strongly temperature dependent, reflecting
+inelastic scattering due to the thermal activation of optical phonons. A linear
+increase of the current with voltage is obtained up to a threshold value at
+which current saturation takes place. We show that the activated behavior, the
+voltage threshold and the saturation current can all be quantitatively
+explained by considering a single optical phonon mode with energy $\hbar \Omega
+\approx 8$ meV. This phonon mode strongly interacts with the surface states of
+the material and represents the dominant source of scattering at the surface at
+high electric fields.",1404.2198v1
+2014-04-10,Existence of optimal ultrafilters and the fundamental complexity of simple theories,"In the first edition of Classification Theory, the second author
+characterized the stable theories in terms of saturation of ultrapowers. Prior
+to this theorem, stability had already been defined in terms of counting types,
+and the unstable formula theorem was known. A contribution of the ultrapower
+characterization was that it involved sorting out the global theory, and
+introducing nonforking, seminal for the development of stability theory. Prior
+to the present paper, there had been no such characterization of an unstable
+class. In the present paper, we first establish the existence of so-called
+optimal ultrafilters on Boolean algebras, which are to simple theories as
+Keisler's good ultrafilters are to all theories. Then, assuming a supercompact
+cardinal, we characterize the simple theories in terms of saturation of
+ultrapowers. To do so, we lay the groundwork for analyzing the global structure
+of simple theories, in ZFC, via complexity of certain amalgamation patterns.
+This brings into focus a fundamental complexity in simple unstable theories
+having no real analogue in stability.",1404.2919v2
+2014-04-18,Predictions for the Spatial Distribution of Gluons in the Initial Nuclear State,"We make predictions for the t-differential cross section of exclusive vector
+meson production (EVMP) in electron-ion collisions, with the aim of comparing
+DGLAP evolution to CGC models. In the current picture for the high-energy
+nucleus, nonlinear effects need to be understood in terms of low-$x$ gluon
+radiation and recombination as well as how this leads to saturation. EVMP
+grants experimental access to the edge region of the highly-boosted nuclear
+wavefunction, where the saturation scale for CGC calculations becomes
+inaccessible to pQCD. On the other hand, DGLAP evolution requires careful
+consideration of unitarity effects. The existing $J/{\psi}$ photoproduction
+data in ep collisions provides a baseline for these theoretical calculations.
+Under different small-$x$ frameworks we obtain a measurable distinction in both
+the shape and normalization of the differential cross section predictions.
+These considerations are relevant for heavy ion collisions because the initial
+state may be further constrained, thus aiding in quantitative study of the
+quark-gluon plasma.",1404.4743v1
+2014-05-20,Periodic and Hyperbolic Soliton Solutions of a Number of Nonlocal PT-Symmetric Nonlinear Equations,"For a number of nonlocal nonlinear equations such as nonlocal, nonlinear
+Schr\""odinger equation (NLSE), nonlocal Ablowitz-Ladik (AL), nonlocal,
+saturable discrete NLSE (DNLSE), coupled nonlocal NLSE, coupled nonlocal AL and
+coupled nonlocal, saturable DNLSE, we obtain periodic solutions in terms of
+Jacobi elliptic functions as well as the corresponding hyperbolic soliton
+solutions. Remarkably, in all the six cases, we find that unlike the
+corresponding local cases, all the nonlocal models simultaneously admit both
+the bright and the dark soliton solutions. Further, in all the six cases, not
+only $\dn(x,m)$ and $\cn(x,m)$ but even their linear superposition is shown to
+be an exact solution. Finally, we show that the coupled nonlocal NLSE not only
+admits solutions in terms of Lam\'e polynomials of order 1, but it also admits
+solutions in terms of Lam\'e polynomials of order 2, even though they are not
+the solutions of the uncoupled nonlocal problem. We also remark on the possible
+integrability in certain cases.",1405.5267v1
+2014-05-26,A numerical study of two-phase miscible flow through porous media with a Lagrangian model,"The multiphase flow mechanism in miscible displacement through porous media
+is an important topic in various applications, such as petroleum engineering,
+low Reynolds number suspension flows, dusty gas dynamics, and fluidized beds.
+To simulate such flows, volume averaging spatial operators are considered to
+incorporate pressure drag and skin friction experienced by a porous medium. In
+this work, a streamline-based Lagrangian methodology is extended for an
+efficient numerical approach to handle dispersion and diffusion of solvent
+saturation during a miscible flow. Overall pressure drag on the diffusion and
+dispersion of solvent saturation is investigated. Numerical results show
+excellent agreement with the results obtained from asymptotic analysis. The
+present numerical simulations indicate that the nonlinear effects due to skin
+friction and pressure drag cannot be accurately captured by Darcy's method if
+the contribution of the skin friction dominates over that of the pressure drag.
+Moreover, mass conservation law is investigated, which is an important feature
+for enhanced oil recovery, and the results help to guide a good agreement with
+theory. This investigation examines how the flow regime may be optimized for
+enhanced oil recovery methods.",1405.6449v2
+2014-06-10,Azimuthal quadrupole correlation from gluon interference in 200 GeV and 7 TeV p+p collisions,"The Balitskii-Fadin-Kuraev-Lipatov (BFKL) multi-Pomeron model of Levin and
+Rezaeian, with extension to the gluon saturation region, is applied to
+long-range pseudorapidity correlations on relative azimuth for low momentum
+final-state hadrons produced in $\sqrt{s}$ = 200~GeV and 7~TeV p+p collisions.
+The multi-Pomeron exchange probabilities in the model were estimated by fitting
+the minimum-bias p+p multiplicity frequency distributions. The multi-Pomeron
+model prediction for the amplitude of the minimum-bias average quadrupole
+correlation, proportional to $\cos 2(\phi_1 - \phi_2)$, is consistent with the
+200~GeV data when theoretically expected gluon saturation momentum scales are
+used. Correlation predictions for the high multiplicity 7~TeV p+p collision
+data are also consistent with the long-range pseudorapidity correlations at
+small relative azimuth observed in the data. The results presented here show
+that the present application of a multiple parton-shower, gluon interference
+mechanism for generating the long-range pseudorapidity, azimuthal quadrupole
+correlation is not excluded by the data.",1406.2736v2
+2014-06-26,Nonlinear Optimal Filter Technique For Analyzing Energy Depositions In TES Sensors Driven Into Saturation,"We present a detailed thermal and electrical model of superconducting
+transition edge sensors (TESs) connected to quasiparticle (qp) traps, such as
+the W TESs connected to Al qp traps used for CDMS (Cryogenic Dark Matter
+Search) Ge and Si detectors. We show that this improved model, together with a
+straightforward time-domain optimal filter, can be used to analyze pulses well
+into the nonlinear saturation region and reconstruct absorbed energies with
+optimal energy resolution.",1406.7030v1
+2014-07-01,Passive Mode-Locking and Tilted Waves in Broad-Area Vertical-Cavity Surface-Emitting Lasers,"We show experimentally and theoretically that an electrically biased
+$200\,\mu$m multi-transverse mode Vertical-Cavity Surface-Emitting Laser can be
+passively mode-locked using optical feedback from a distant Resonant Saturable
+Absorber Mirror. This is achieved when one cavity is placed at the Fourier
+plane of the other. Such non conventional optical feedback leads to the
+formation of two tilted plane waves traveling in the external cavity with
+opposite transverse components and alternating in time at every round-trip.
+Each of these plane waves gives birth to a train of mode-locked pulses
+separated by twice the external cavity round-trip, while the two trains are
+time shifted by a round-trip. A large portion of the transverse section of the
+device contributes to mode-locked emission leading to pulses of approximately 1
+W peak power and 10 ps width. We discuss how inhomogeneities in the transverse
+section of the saturable absorber select the emitted tilted waves, thus leading
+to tunable emission over 4 nm.",1407.0296v1
+2014-07-22,Proving Threshold Saturation for Nonbinary SC-LDPC Codes on the Binary Erasure Channel,"We analyze nonbinary spatially-coupled low-density parity-check (SC-LDPC)
+codes built on the general linear group for transmission over the binary
+erasure channel. We prove threshold saturation of the belief propagation
+decoding to the potential threshold, by generalizing the proof technique based
+on potential functions recently introduced by Yedla et al.. The existence of
+the potential function is also discussed for a vector sparse system in the
+general case, and some existence conditions are developed. We finally give
+density evolution and simulation results for several nonbinary SC-LDPC code
+ensembles.",1407.5783v1
+2014-07-24,Saturated Graphs of Prescribed Minimum Degree,"A graph $G$ is $H$-saturated if it contains no copy of $H$ as a subgraph but
+the addition of any new edge to $G$ creates a copy of $H$. In this paper we are
+interested in the function sat$_{t}(n,p)$, defined to be the minimum number of
+edges that a $K_{p}$-saturated graph on $n$ vertices can have if it has minimum
+degree at least $t$. We prove that sat$_{t}(n,p) = tn - O(1)$, where the limit
+is taken as $n$ tends to infinity. This confirms a conjecture of Bollob\'as
+when $p = 3$. We also present constructions for graphs that give new upper
+bounds for sat$_{t}(n,p)$ and discuss an analogous problem for saturated
+hypergraphs.",1407.6664v2
+2014-07-29,$^3$H/$^3$He ratio as a probe of the nuclear symmetry energy at sub-saturation densities,"Within the newly updated version of the Ultra-relativistic quantum molecular
+dynamics (UrQMD) model in which the Skyrme potential energy-density functional
+is introduced, the yield ratio between $^3$H and $^3$He clusters emitted from
+central $^{40}$Ca+$^{40}$Ca, $^{96}$Zr+$^{96}$Zr, $^{96}$Ru+$^{96}$Ru, and
+$^{197}$Au+$^{197}$Au collisions in the beam energy range from 0.12 to 1
+GeV$/$nucleon is studied. The recent FOPI data for the $^3$H$/$$^3$He ratio are
+compared with UrQMD calculations using 13 Skyrme interactions (all exhibiting
+similar values of iso-scalar incompressibility but very different density
+dependences of the symmetry energy). It is found that the $^3$H$/$$^3$He ratio
+is sensitive to the nuclear symmetry energy at sub-saturation densities. Model
+calculations with moderately soft to linear symmetry energies are in agreement
+with the experimental FOPI data. This result is in line with both, the recent
+constraints on the low-density symmetry energy available in the literature and
+our previous results for the high-density symmetry energy obtained with the
+elliptic flow of free nucleons and hydrogen isotopes as a sensitive probe.",1407.7625v1
+2014-07-30,Constraining the density slope of nuclear symmetry energy at subsaturation densities using electric dipole polarizability in $^{208}$Pb,"Nuclear structure observables usually most effectively probe the properties
+of nuclear matter at subsaturation densities rather than at saturation density.
+We demonstrate that the electric dipole polarizibility $\alpha _ {\text{D}}$ in
+$^{208}$Pb is sensitive to both the magnitude $E_{\text{sym}}(\rho_{\text{c}})$
+and density slope $L(\rho_{\text{c}})$ of the symmetry energy at a
+subsaturation cross density $\rho_{\text{c}} = 0.11$ fm$^{-3}$. Using the
+experimental data of $\alpha _ {\text{D}}$ in $^{208}$Pb from RCNP and the
+recent accurate constraint of $E_{\text{sym}}(\rho_{\text{c}})$ from the
+binding energy difference of heavy isotope pairs, we extract a value of
+$L(\rho_{\text{c}}) = 47.3 \pm 7.8$ MeV. The implication of the present
+constraint of $L(\rho_{\text{c}})$ to the symmetry energy at saturation
+density, the neutron skin thickness of $^{208}$Pb and the core-crust transition
+density in neutron stars is discussed.",1407.8054v2
+2014-07-31,Passive mode-locking under higher order effects,"The response of a passive mode-locking mechanism, where gain and spectral
+filtering are saturated with the energy and loss saturated with the power, is
+examined under the presence of higher order effects. These include third order
+dispersion, self-steepening and Raman gain. The locking mechanism is maintained
+even with these terms; mode-locking occurs for both the anomalous and normal
+regimes. In the anomalous regime, these perturbations are found to affect the
+speed but not the structure of the (locked) pulses. In fact, these pulses
+behave like solitons of a classical nonlinear Schrodinger equation and as such
+a soliton perturbation theory is used to verify the numerical observations. In
+the normal regime, the effect of the perturbations is small, in line with
+recent experimental observations. The results in the normal regime are verified
+mathematically using a WKB type asymptotic theory. Finally, bi-solitons are
+found to behave as dark solitons on top of a stable background and are
+significantly affected by these perturbations.",1408.0041v1
+2014-08-28,Channeling Effect in Polycrystalline Deuterium-Saturated CVD Diamond Target Bombarded by Deuterium Ion Beam,"At the ion accelerator HELIS at the LPI, the neutron yield is investigated in
+DD reactions within a polycrystalline deuterium-saturated CVD diamond, during
+an irradiation of its surface by a deuterium ion beam with the energy less than
+30 keV. The measurements of the neutron flux in the beam direction are
+performed in dependence on the target angle, \b{eta}, with respect to the beam
+axis. These measurements are performed using a multichannel detector based on
+He3 counters. A significant anisotropy in neutron yield is observed, it was
+higher by a factor of 3 at \b{eta}=0 compared to that at \b{eta} = +-45{\deg}.
+The possible reasons for the anisotropy, including ion channeling, are
+discussed.",1408.7109v2
+2014-09-11,Coherent inelastic backscattering of laser light from three isotropic atoms,"We study the impact of double and triple scattering contributions on coherent
+backscattering of laser light from saturated isotropic atoms, in the helicity
+preserving polarization channel. Using the recently proposed diagrammatic
+pump-probe approach, we analytically derive single-atom spectral responses to a
+classical polychromatic driving field, combine them self-consistently to double
+and triple scattering processes, and numerically deduce the corresponding
+elastic and inelastic spectra, as well as the total backscattered intensities.
+We find that account of the triple scattering contribution leads to a faster
+decay of phase-coherence with increasing saturation of the atomic transition as
+compared to double scattering alone, and to a better agreement with the
+experiment on strontium atoms.",1409.3597v2
+2014-09-12,The Direct and Converse Inequalities for Jackson-Type Operators on Spherical Cap,"Approximation on the spherical cap is different from that on the sphere which
+requires us to construct new operators. This paper discusses the approximation
+on the spherical cap. That is, so called Jackson-type operator
+$\{J_{k,s}^m\}_{k=1}^{\infty}$ is constructed to approximate the function
+defined on the spherical cap $D(x_0,\gamma)$. We thus establish the direct and
+inverse inequalities and obtain saturation theorems for
+$\{J_{k,s}^m\}_{k=1}^{\infty}$ on the cap $D(x_0,\gamma)$. Using methods of
+$K$-functional and multiplier, we obtain the inequality \begin{eqnarray*}
+C_1\:\| J_{k,s}^m(f)-f\|_{D,p}\leq \omega^2\left(f,\:k^{-1}\right)_{D,p} \leq
+C_2 \max_{v\geq k}\| J_{v,s}^m(f) - f\|_{D,p} \end{eqnarray*} and that the
+saturation order of these operators is $O(k^{-2})$, where
+$\omega^2\left(f,\:t\right)_{D,p}$ is the modulus of smoothness of degree 2,
+the constants $C_1$ and $C_2$ are independent of $k$ and $f$.",1409.3807v1
+2014-09-19,Quasi-Stable ideals and Borel-fixed ideals with a given Hilbert Polynomial,"The present paper investigates properties of quasi-stable ideals and of
+Borel-fixed ideals in a polynomial ring $k[x_0,\dots,x_n]$, in order to design
+two algorithms: the first one takes as input $n$ and an admissible Hilbert
+polynomial $P(z)$, and outputs the complete list of saturated quasi-stable
+ideals in the chosen polynomial ring with the given Hilbert polynomial. The
+second algorithm has an extra input, the characteristic of the field $k$, and
+outputs the complete list of saturated Borel-fixed ideals in $k[x_0,\dots,x_n]$
+with Hilbert polynomial $P(z)$. The key tool for the proof of both algorithms
+is the combinatorial structure of a quasi-stable ideal, in particular we use a
+special set of generators for the considered ideals, the Pommaret basis.",1409.5569v2
+2014-09-25,Nuclear Matter from Effective Quark-Quark Interaction,"We study neutron matter and symmetric nuclear matter with the quark-meson
+model for the two-nucleon interaction. The Bethe-Bruckner-Goldstone many-body
+theory is used to describe the correlations up to the three hole-line
+approximation with no extra parameters. At variance with other non-relativistic
+realistic interactions, the three hole-line contribution turns out to be
+non-negligible and to have a substantial saturation effect. The saturation
+point of nuclear matter, the compressibility, the symmetry energy and its slope
+are within the phenomenological constraints. Since the interaction also
+reproduces fairly well the properties of the three nucleon system, these
+results indicate that the explicit introduction of the quark degrees of freedom
+within the considered constituent quark model is expected to reduce the role of
+three-body forces.",1409.7206v2
+2014-09-30,Error-correction of linear codes via colon ideals,"We show that errors in data transmitted through linear codes can be thought
+of as codewords of minimum weight of new linear codes. To determine errors we
+can then use methods specific to finding such special codewords. One of these
+methods consists of finding the primary decomposition of the saturation of a
+certain homogeneous ideal. When good words (i.e. vectors with a unique nearest
+neighbor) are error-corrected, the saturated ideal is just the prime ideal of a
+point (so the primary decomposition is superfluously determined); we show that
+this ideal can be computed by coloning the original homogeneous ideal with a
+power of a certain variable. We then determine the smallest such power for any
+linear code.",1409.8387v2
+2014-10-07,Thermal properties of asymmetric nuclear matter with an improved isospin- and momentum-dependent interaction,"Thermal properties of asymmetric nuclear matter, including the temperature
+dependence of the symmetry energy, single-particle properties, and differential
+isospin fractionation, are investigated with different neutron-proton effective
+mass splittings using an improved isospin- and momentum-dependent interaction.
+In this improved interaction, the momentum-dependence of the isoscalar
+single-particle potential at saturation density is well fitted to that
+extracted from optical model analyses of proton-nucleus scattering data up to
+nucleon kinetic energy of 1 GeV, and the isovector properties, i.e., the slope
+of the nuclear symmetry energy, the momentum-dependence of the symmetry
+potential, and the symmetry energy at saturation density can be flexibly
+adjusted via three parameters $x$, $y$, and $z$, respectively. Our results
+indicate that the nucleon phase-space distribution in equilibrium, the
+temperature dependence of the symmetry energy, and the differential isospin
+fractionation can be significantly affected by the isospin splitting of nucleon
+effective mass.",1410.1604v2
+2014-10-08,Inverse semigroup actions on groupoids,"We define inverse semigroup actions on topological groupoids by partial
+equivalences. From such actions, we construct saturated Fell bundles over
+inverse semigroups and non-Hausdorff \'etale groupoids. We interpret these as
+actions on C*-algebras by Hilbert bimodules and describe the section algebras
+of these Fell bundles.
+  Our constructions give saturated Fell bundles over non-Hausdorff \'etale
+groupoids that model actions on locally Hausdorff spaces. We show that these
+Fell bundles are usually not Morita equivalent to an action by automorphisms.
+That is, the Packer-Raeburn Stabilisation Trick does not generalise to
+non-Hausdorff groupoids.",1410.2051v5
+2014-10-08,"Resonance dynamics in the coherent $η$ meson production in the $(p,p^\prime)$ reaction on the spin-isospin saturated nucleus","For the forward going proton and $\eta$ meson, the coherent $\eta$ meson
+production in the $(p,p^\prime)$ reaction on the spin-isospin saturated nucleus
+occurs only due to the $\eta$ meson exchange interaction between the beam
+proton and nucleus. In this process, the nucleon in the nucleus can be excited
+to resonances $N^*$ and the $\eta$ meson in the final state can arise due to
+$N^* \to N\eta$. We investigate the dynamics of resonances, including nucleon
+Born terms, and their interferences in the coherently added cross section of
+this reaction. We discuss the importance of $N(1520)$ resonance and show the
+sensitivity of the cross section to the hadron nucleus interaction.",1410.2062v1
+2014-10-20,Why mean $p_{\rm T}$ is interesting,"We discuss energy dependence of mean $p_{\rm T}$ correlation with $N_{\rm
+ch}$ basing on general features of high energy collisions such as saturation
+and geometrical scaling. We use Color Glass Condensate calculation of an
+effective interaction radius that scales as a third root of multiplicity, and
+then saturates. With this model input we construct scaling variable for $<
+p_{\rm T} > (N_{\rm ch})$ at different energies both for pp and pPb collisions,
+and show that recent ALICE data indeed does exhibit this scaling property. We
+discuss energy dependence of the interaction radius and argue that since the
+radius cannot grow too large, a universal behavior of $< p_{\rm T} >$ for large
+multiplicities is expected.",1410.5220v2
+2014-10-28,Dark counts initiated by macroscopic quantum tunneling in NbN superconducting photon detectors,"We perform measurements of the switching current distributions of three w =
+120 nm wide, 4 nm thick NbN superconducting strips which are used for
+single-photon detectors. These strips are much wider than the diameter the
+vortex cores, so they are classified as quasi-two-dimensional (quasi-2D). We
+discover evidence of macroscopic quantum tunneling by observing the saturation
+of the standard deviation of the switching distributions at temperatures around
+2 K. We analyze our results using the Kurkijarvi-Garg model and find that the
+escape temperature also saturates at low temperatures, confirming that at
+sufficiently low temperatures, macroscopic quantum tunneling is possible in
+quasi-2D strips and can contribute to dark counts observed in single photon
+detectors.",1410.7689v2
+2014-11-03,Equation of state of nuclear matter from empirical constraints,"From empirically determined values of some of the characteristic constants
+associated with homogeneous nuclear matter at saturation and sub-saturation
+densities, within the framework of a Skyrme-inspired energy density functional,
+we construct an equation of state (EoS) of nuclear matter.This EoS is then used
+to predict values of density slope parameters of symmetry energy $L(\rho)$,
+isoscalar incompressibility $K(\rho)$ and a few related quantities. The close
+consonance of our predicted values with the currently available ones for the
+density dependence of symmetry energy and incompressibility gleaned from
+diverse approaches offers the possibility that our method may help in settling
+their values in tighter bounds. Extrapolation of our EoS at supranormal
+densities shows that it is in good harmony with the one extracted from
+experimental data.",1411.0404v1
+2014-11-11,Cooperative quasi-Cherenkov radiation,"We study the features of cooperative parametric (quasi-Cherenkov) radiation
+arising when initially unmodulated electron (positron) bunches pass through a
+crystal (natural or artificial) under the conditions of dynamical diffraction
+of electromagnetic waves in the presence of shot noise. A detailed numerical
+analysis is given for cooperative THz radiation in artificial crystals. The
+radiation intensity above 200~MW$/$cm$^2$ is obtained in simulations.
+  In two- and three-wave diffraction cases, the peak intensity of cooperative
+radiation emitted at small and large angles to particle velocity is
+investigated as a function of the particle number in an electron bunch. The
+peak radiation intensity appeared to increase monotonically until saturation is
+achieved. At saturation, the shot noise causes strong fluctuations in the
+intensity of cooperative parametric radiation.
+  It is shown that the duration of radiation pulses can be much longer than the
+particle flight time through the crystal. This enables a thorough experimental
+investigation of the time structure of cooperative parametric radiation
+generated by electron bunches available with modern accelerators.
+  The complicated time structure of cooperative parametric (quasi-Cherenkov)
+radiation can be observed in artificial (electromagnetic, photonic) crystals in
+all spectral ranges (X-ray, optical, terahertz, and microwave).",1411.2960v1
+2014-11-19,Quantum enhanced precision in a collective measurement,"We explore the role of $\textit{collective measurements}$ on precision in
+estimation of a single parameter. Collective measurements are represented by
+observables which commute with all permutations of the probe particles. We show
+that with this constraint, quantum bits(qubits) outperform classical
+bits(non-superposable bits) in optimizing precision. Specifically, we prove
+that while precision in a collective measurement is loosely bounded by
+$O\left(\frac{1}{N}\right)$ for $N$ classical bits, using qubits it is tightly
+bounded by $O\left(\frac{1}{N^2}\right)$. This bound is consistent with quantum
+metrology protocols with the collective measurement requiring an entangled
+probe state to saturate. Finally, we construct a canonical measurement protocol
+that saturates this bound.",1411.5090v3
+2014-11-26,"Higher dimensional Frobenius problem: Maximal saturated cone, growth function and rigidity","We consider $m$ integral vectors $X_1,...,X_m \in \mathbb{Z}^s$ located in a
+half-space of $\mathbb{R}^s$ ($m\ge s\geq 1$) and study the structure of the
+additive semi-group $X_1 \mathbb{N} +... + X_m \mathbb{N}$. We introduce and
+study maximal saturated cone and directional growth function which describe
+some aspects of the structure of the semi-group. When the vectors $X_1, ...,
+X_m$ are located in a fixed hyperplane, we obtain an explicit formula for the
+directional growth function and we show that this function completely
+characterizes the defining data $(X_1, ..., X_m)$ of the semi-group. The last
+result will be applied to the study of Lipschitz equivalence of Cantor sets
+(see [H. Rao and Y. Zhang, Higher dimensional Frobenius problem and Lipschitz
+equivalence of Cantor sets, Preprint 2014]).",1411.7118v1
+2014-12-10,Wave-particle interactions with parallel whistler waves: nonlinear and time-dependent effects revealed by Particle-in-Cell simulations,"We present a self-consistent Particle-in-Cell simulation of the resonant
+interactions between anisotropic energetic electrons and a population of
+whistler waves, with parameters relevant to the Earths radiation belt. By
+tracking PIC particles, and comparing with test-particle simulations we
+emphasize the importance of including nonlinear effects and time evolution in
+the modeling of wave-particle interactions, which are excluded in the resonant
+limit of quasi- linear theory routinely used in radiation belt studies. In
+particular we show that pitch angle diffusion is enhanced during the linear
+growth phase, and it rapidly saturates well before a single bounce period. This
+calls into question the widely used bounce average performed in most radiation
+belt diffusion calculations. Furthermore we discuss how the saturation is
+related to the fact that the domain in which the,particles pitch angle diffuse
+is bounded, and to the well-known problem of $90^\circ$ diffusion barrier
+diffusion barrier.",1412.3229v2
+2014-12-16,Asymmetric Wave Propagation Through Saturable Nonlinear Oligomers,"In the present paper we consider nonlinear dimers and trimers (more
+generally, oligomers) embedded within a linear Schr{\""o}dinger lattice where
+the nonlinear sites are of saturable type. We examine the stationary states of
+such chains in the form of plane waves, and analytically compute their
+reflection and transmission coefficients through the nonlinear oligomer, as
+well as the corresponding rectification factors which clearly illustrate the
+asymmetry between left and right propagation in such systems. We examine not
+only the existence but also the dynamical stability of the plane wave states.
+Lastly, we generalize our numerical considerations to the more physically
+relevant case of Gaussian initial wavepackets and confirm that the asymmetry in
+the transmission properties also persists in the case of such wavepackets.",1412.4856v1
+2014-12-19,Iterated fractional Tikhonov regularization,"Fractional Tikhonov regularization methods have been recently proposed to
+reduce the oversmoothing property of the Tikhonov regularization in standard
+form, in order to preserve the details of the approximated solution. Their
+regularization and convergence properties have been previously investigated
+showing that they are of optimal order. This paper provides saturation and
+converse results on their convergence rates. Using the same iterative
+refinement strategy of iterated Tikhonov regularization, new iterated
+fractional Tikhonov regularization methods are introduced. We show that these
+iterated methods are of optimal order and overcome the previous saturation
+results. Furthermore, nonstationary iterated fractional Tikhonov regularization
+methods are investigated, establishing their convergence rate under general
+conditions on the iteration parameters. Numerical results confirm the
+effectiveness of the proposed regularization iterations.",1412.6540v1
+2015-02-02,Growing Probability of Additional Offspring with a Beneficial Reversal Allele in the Decoupled Continuous-time Mutation-selection Model,"The growing probabilities of additional offspring with the beneficial
+reversal allele for various population sizes, $N$, sequence lengths, $L$,
+selective advantages, $s$, fitness parameters, $k$, and measuring parameters,
+$C$, were calculated in an asymmetric sharply-peaked landscape using the
+decoupled continuous-time mutation-selection model. The growing probability in
+the stochastic region was inversely proportional to the measuring parameter
+when $C<1/Ns^*$, bent when $C\approx 1/Ns^*$ and became saturated when
+$C>1/Ns^*$, where $s^*$ is the effective selective advantage. The saturated
+growing probability in the stochastic region was approximately the effective
+selective advantage when $C\gg 1/Ns^*$ and $s^*\ll 1$. The present study
+suggests that the growing probability in the stochastic region in an asymmetric
+sharply-peaked landscape in the decoupled continuous-time mutation-selection
+model can be described using the theoretical formula for the growing
+probability in the Moran two-allele model. The selective advantage ratio, which
+represents the ratio of the effective selective advantage to the selective
+advantage, does not depend on the population size, selective advantage,
+measuring parameter, and fitness parameter; instead the selective advantage
+ratio decreases with increasing the sequence length.",1502.00415v1
+2015-02-08,LineSwitch: Efficiently Managing Switch Flow in Software-Defined Networking while Effectively Tackling DoS Attacks,"Software Defined Networking (SDN) is a new networking architecture which aims
+to provide better decoupling between network control (control plane) and data
+forwarding functionalities (data plane). This separation introduces several
+benefits, such as a directly programmable and (virtually) centralized network
+control. However, researchers showed that the required communication channel
+between the control and data plane of SDN creates a potential bottleneck in the
+system, introducing new vulnerabilities. Indeed, this behavior could be
+exploited to mount powerful attacks, such as the control plane saturation
+attack, that can severely hinder the performance of the whole network.
+  In this paper we present LineSwitch, an efficient and effective solution
+against control plane saturation attack. LineSwitch combines SYN proxy
+techniques and probabilistic blacklisting of network traffic. We implemented
+LineSwitch as an extension of OpenFlow, the current reference implementation of
+SDN, and evaluate our solution considering different traffic scenarios (with
+and without attack). The results of our preliminary experiments confirm that,
+compared to the state-of-the-art, LineSwitch reduces the time overhead up to
+30%, while ensuring the same level of protection.",1502.02234v1
+2015-02-11,Hydrogenation at low temperatures does not always lead to saturation: the case of HNCO,"Context. It is generally agreed that hydrogenation reactions dominate
+chemistry on grain surfaces in cold, dense molecular cores, saturating the
+molecules present in ice mantles. Aims. We present a study of the low
+temperature reactivity of solid phase isocyanic acid (HNCO) with hydrogen
+atoms, with the aim of elucidating its reaction network. Methods. Fourier
+transform infrared spectroscopy and mass spectrometry were employed to follow
+the evolution of pure HNCO ice during bombardment with H atoms. Both multilayer
+and monolayer regimes were investigated. Results. The hydrogenation of HNCO
+does not produce detectable amounts of formamide (NH2CHO) as the major product.
+Experiments using deuterium reveal that deuteration of solid HNCO occurs
+rapidly, probably via cyclic reaction paths regenerating HNCO. Chemical
+desorption during these reaction cycles leads to loss of HNCO from the surface.
+Conclusions. It is unlikely that significant quantities of NH2CHO form from
+HNCO. In dense regions, however, deuteration of HNCO will occur. HNCO and DNCO
+will be introduced into the gas phase, even at low temperatures, as a result of
+chemical desorption.",1502.03282v1
+2015-02-16,Coherence properties of the radiation from FLASH,"FLASH is the first free electron laser user facility operating in the vacuum
+ultraviolet and soft x-ray wavelength range. Many user experiments require
+knowledge of the spatial and temporal coherence properties of the radiation. In
+this paper we present an analysis of the coherence properties of the radiation
+for the fundamental and for the higher odd frequency harmonics. We show that
+temporal and spatial coherence reach maximum close to the FEL saturation but
+may degrade significantly in the post-saturation regime. We also find that the
+pointing stability of short FEL pulses is limited due to the fact that
+non-azimuthal FEL eigenmodes are not sufficiently suppressed. We discuss
+possible ways for improving the degree of transverse coherence and the pointing
+stability.",1502.04486v1
+2015-03-02,A Novel Image Steganographic Approach for Hiding Text in Color Images using HSI Color Model,"Image Steganography is the process of embedding text in images such that its
+existence cannot be detected by Human Visual System (HVS) and is known only to
+sender and receiver. This paper presents a novel approach for image
+steganography using Hue-Saturation-Intensity (HSI) color space based on Least
+Significant Bit (LSB). The proposed method transforms the image from RGB color
+space to Hue-Saturation-Intensity (HSI) color space and then embeds secret data
+inside the Intensity Plane (I-Plane) and transforms it back to RGB color model
+after embedding. The said technique is evaluated by both subjective and
+Objective Analysis. Experimentally it is found that the proposed method have
+larger Peak Signal-to Noise Ratio (PSNR) values, good imperceptibility and
+multiple security levels which shows its superiority as compared to several
+existing methods",1503.00388v1
+2015-03-02,Absorption Coefficients of the Methane-Nitrogen Binary Ice System: Implications for Pluto,"The methane-nitrogen phase diagram of Prokhvatilov and Yantsevich (1983)
+indicates that at temperatures relevant to the surfaces of icy dwarf planets
+like Pluto, two phases contribute to the methane absorptions: nitrogen
+saturated with methane $\bf{\bar{N_{2}}}$:CH$_{4}$ and methane saturated with
+nitrogen $\bf{\bar{CH_{4}}}$:N$_{2}$. No optical constants are available so far
+for the latter component limiting construction of a proper model, in compliance
+with thermodynamic equilibrium considerations. New optical constants for solid
+solutions of methane diluted in nitrogen (N$_{2}$:CH$_{4}$) and nitrogen
+diluted in methane (CH$_{4}$:N$_{2}$) are presented at temperatures between 40
+and 90 K, in the wavelength range 1.1-2.7 $\mu$m at different mixing ratios.
+These optical constants are derived from transmission measurements of crystals
+grown from the liquid phase in closed cells. A systematic study of the changes
+of methane and nitrogen solid mixtures spectral behavior with mixing ratio and
+temperature is presented.",1503.00703v1
+2015-03-05,Do We Need More Training Data?,"Datasets for training object recognition systems are steadily increasing in
+size. This paper investigates the question of whether existing detectors will
+continue to improve as data grows, or saturate in performance due to limited
+model complexity and the Bayes risk associated with the feature spaces in which
+they operate. We focus on the popular paradigm of discriminatively trained
+templates defined on oriented gradient features. We investigate the performance
+of mixtures of templates as the number of mixture components and the amount of
+training data grows. Surprisingly, even with proper treatment of regularization
+and ""outliers"", the performance of classic mixture models appears to saturate
+quickly ($\sim$10 templates and $\sim$100 positive training examples per
+template). This is not a limitation of the feature space as compositional
+mixtures that share template parameters via parts and that can synthesize new
+templates not encountered during training yield significantly better
+performance. Based on our analysis, we conjecture that the greatest gains in
+detection performance will continue to derive from improved representations and
+learning algorithms that can make efficient use of large datasets.",1503.01508v1
+2015-03-08,Direct Observationof DegenerateTwo-Photon Absorption and Its Saturation in WS2 and MoS2 Monolayer and Few-Layer Films,"The optical nonlinearity of WS2, MoS2 monolayer and few-layer films was
+investigated using the Z-scan technique with femtosecond pulses from the
+visible to the near infrared. The dependence of nonlinear absorption of the WS2
+and MoS2 films on layer number and excitation wavelength was studied
+systematically. WS2 with 1~3 layers exhibits a giant two-photon absorption
+(TPA) coefficient. Saturation of TPA for WS2 with 1~3 layers and MoS2 with
+25~27 layers was observed. The giant nonlinearity of WS2 and MoS2 is attributed
+to two dimensional confinement, a giant exciton effect and the band edge
+resonance of TPA.",1503.02258v2
+2015-03-31,Minimal energy solutions and infinitely many bifurcating branches for a class of saturated nonlinear Schrödinger systems,"We prove a conjecture which was recently formulated by Maia, Montefusco,
+Pellacci saying that minimal energy solutions of the saturated nonlinear
+Schr\""odinger system \begin{align*}
+  - \Delta u + \lambda_1 u &= \frac{\alpha u(\alpha u^2+\beta v^2)}{1+s(\alpha
+u^2+\beta v^2)}
+  \qquad\text{in }\mathbb{R}^n, \newline
+  - \Delta v + \lambda_2 v &= \frac{\beta v(\alpha u^2+\beta v^2)}{1+s(\alpha
+u^2+\beta v^2)}\qquad\text{in
+  }\mathbb{R}^n \end{align*} are necessarily semitrivial whenever
+$\alpha,\beta,\lambda_1,\lambda_2>0$ and
+$0<s<\max\{\frac{\alpha}{\lambda_1},\frac{\beta}{\lambda_2}\}$ except for the
+symmetric case $\lambda_1=\lambda_2,\alpha=\beta$. Moreover it is shown that
+for most parameter samples $\alpha,\beta,\lambda_1,\lambda_2$ there are
+infinitely many branches containing seminodal solutions which bifurcate from a
+semitrivial solution curve parametrized by $s$.",1503.08974v1
+2015-04-06,More on Heisenberg's model for high energy nucleon-nucleon scattering,"We revisit Heisenberg's model for nucleon-nucleon scattering which admits a
+saturation of the Froissart bound. We examine its uniqueness, and find that up
+to certain natural generalizations, it is the only action that saturates the
+bound. We find that we can extract also sub-leading behaviour for $\sigma_{\rm
+tot}(s)$ from it, though that requires a knowledge of the wavefunction solution
+that is hard to obtain, and a black-disk model allows the calculation of
+$\sigma_{elastic}(s)$ as well.
+  The wavefunction solution is analyzed perturbatively, and its source is
+interpreted. Generalizations to several mesons, addition of vector mesons, and
+curved space regimes are also found. We discuss the relations between
+Heisenberg's model and holographic models that are dual to QCD-like theories.",1504.01328v1
+2015-04-18,Black phosphorus a new saturable absorber material for ultrashort pulse generation,"Low-dimensional materials, due to their versatile properties are very
+interesting for numerous electronics and optoelectronics applications. Recently
+rediscovered black phosphorus, with a graphite-like structure can be exfoliated
+up to the single atomic layer. In contrary to graphene it possesses a direct
+band gap controllable by the number of stacked atomic layers. For those
+reasons, it is now intensively investigated. Here we demonstrate, that black
+phosphorus can serve as a broadband saturable absorber and can be used for
+ultrashort optical pulse generation. The mechanically exfoliated ~300 nm thick
+layers of black phosphorus were transferred onto the fiber core and under
+pulsed excitation at 1560 nm wavelength its transmission increases by 4.4%. It
+was used to generate 272 fs-short pulses at 1550 nm and 739 fs at 1910 nm. The
+obtained results shows that black phosphorus can be effectively used for
+ultrashort pulse generation and proves its great potential to future
+applications.",1504.04731v1
+2015-04-23,Modeling of dual-metal Schottky contacts based silicon micro and nano wire solar cells,"We study solar cell properties of single silicon wires connected at their
+ends to two dissimilar metals of different work functions. Effects of wire
+dimensions, the work functions of the metals, and minority carrier lifetimes on
+short circuit current as well as open circuit voltage are studied. The most
+efficient photovoltaic behavior is found to occur when one metal makes a
+Schottky contact with the wire, and the other makes an Ohmic contact. As wire
+length increases, both short circuit current and open circuit voltage increase
+before saturation occurs. Depending on the work function difference between the
+metals and the wire dimensions, the saturation length increases by
+approximately an order of magnitude with a two order magnitude increase in
+minority carrier length. However current per surface area exposed to light is
+found to decrease rapidly with increase in length. The use of a multi-contact
+interdigitated design for long wires is investigated to increase the
+photovoltaic response of the devices.",1504.06279v1
+2015-04-27,Full-duplex MAC Protocol Design and Analysis,"The idea of in-band full-duplex (FD) communications revives in recent years
+owing to the significant progress in the self-interference cancellation and
+hardware design techniques, offering the potential to double spectral
+efficiency. The adaptations in upper layers are highly demanded in the design
+of FD communication systems. In this letter, we propose a novel medium access
+control (MAC) using FD techniques that allows transmitters to monitor the
+channel usage while transmitting, and backoff as soon as collision happens.
+Analytical saturation throughput of the FD-MAC protocol is derived with the
+consideration of imperfect sensing brought by residual self- interference (RSI)
+in the PHY layer. Both analytical and simulation results indicate that the
+normalized saturation throughput of the proposed FD-MAC can significantly
+outperforms conventional CSMA/CA under various network conditions.",1504.06957v1
+2015-05-09,Stability analysis of the Biot/squirt models for wave propagation in saturated porous media,"This work is concerned with the Biot/squirt (BISQ) models for wave
+propagation in saturated porous media. We show that the models allow
+exponentially exploding solutions, as time goes to infinity, when the
+characteristic squirt-flow coefficient is negative or has a non-zero imaginary
+part. We also show that the squirt-flow coefficient does have non-zero
+imaginary parts for some experimental parameters. Because the models are
+linear, the existence of such exploding solutions indicates instability of the
+BISQ models. This result calls on a reconsideration of the widely used BISQ
+theory. Furthermore, we demonstrate that the 3D isotropic BISQ model is stable
+when the squirt-flow coefficient is positive. In particular, the original Biot
+model is unconditionally stable where the squirt-flow coefficient is 1.",1505.02283v1
+2015-05-12,Single-cell measurement of red blood cell oxygen affinity,"Oxygen is transported throughout the body by hemoglobin in red blood cells.
+While the oxygen affinity of blood is well understood and is routinely assessed
+in patients by pulse oximetry, variability at the single-cell level has not
+been previously measured. In contrast, single-cell measurements of red blood
+cell volume and hemoglobin concentration are taken millions of times per day by
+clinical hematology analyzers and are important factors in determining the
+health of the hematologic system. To better understand the variability and
+determinants of oxygen affinity on a cellular level, we have developed a system
+that quantifies the oxygen saturation, cell volume and hemoglobin concentration
+for individual red blood cells in high-throughput. We find that the variability
+in single-cell saturation peaks at an oxygen partial pressure of 2.5%, which
+corresponds to the maximum slope of the oxygen-hemoglobin dissociation curve.
+In addition, single-cell oxygen affinity is positively correlated with
+hemoglobin concentration, but independent of osmolarity, which suggests
+variation in the hemoglobin to 2-3 DPG ratio on a cellular level. By
+quantifying the functional behavior of a cellular population, our system adds a
+new dimension to blood cell analysis and other measurements of single-cell
+variability.",1505.04119v1
+2015-05-21,The lattice gluon propagator in renormalizable $ξ$ gauges,"We study the SU(3) gluon propagator in renormalizable $R_\xi$ gauges
+implemented on a symmetric lattice with a total volume of (3.25 fm)$^4$ for
+values of the guage fixing parameter up to $\xi=0.5$. As expected, the
+longitudinal gluon dressing function stays constant at its tree-level value
+$\xi$. Similar to the Landau gauge, the transverse $R_\xi$ gauge gluon
+propagator saturates at a non-vanishing value in the deep infrared for all
+values of $\xi$ studied. We compare with very recent continuum studies and
+perform a simple analysis of the found saturation with a dynamically generated
+effective gluon mass.",1505.05897v1
+2015-05-23,Mid-infrared ultra-short mode-locked fiber laser utilizing topological insulator Bi2Te3 nano-sheets as the saturable absorber,"The newly-emergent two-dimensional topological insulators (TIs) have shown
+their unique electronic and optical properties, such as good thermal
+management, high nonlinear refraction index and ultrafast relaxation time.
+Their narrow energy band gaps predict their optical absorption ability further
+into the mid-infrared region and their possibility to be very broadband light
+modulators ranging from the visible to the mid-infrared region. In this paper,
+a mid-infrared mode-locked fluoride fiber laser with TI Bi2Te3 nano-sheets as
+the saturable absorber is presented. Continuous wave lasing, Q-switched and
+continuous-wave mode-locking (CW-ML) operations of the laser are observed
+sequentially by increasing the pump power. The observed CW-ML pulse train has a
+pulse repetition rate of 10.4 MHz, a pulse width of ~6 ps, and a center
+wavelength of 2830 nm. The maximum achievable pulse energy is 8.6 nJ with
+average power up to 90 mW. This work forcefully demonstrates the promising
+applications of two-dimensional TIs for ultra-short laser operation and
+nonlinear optics in the mid-infrared region.",1505.06322v1
+2015-05-30,Layered posets and Kunen's universal collapse,"We develop the theory of layered posets, and use the notion of layering to
+prove a new iteration theorem (Theorem 6): if $\kappa$ is weakly compact then
+any universal Kunen iteration of $\kappa$-cc posets (each possibly of size
+$\kappa$) is $\kappa$-cc, as long as direct limits are used sufficiently often.
+This iteration theorem simplifies and generalizes the various chain condition
+arguments for universal Kunen iterations in the literature on saturated ideals,
+especially in situations where finite support iterations are not possible. We
+also provide two applications: (1) For any $n \ge 1$, a wide variety of
+$<\omega_{n-1}$-closed, $\omega_{n+1}$-cc posets of size $\omega_{n+1}$ can
+consistently be absorbed (as regular suborders) by quotients of saturated
+ideals on $\omega_n$ (see Theorem 7 and Corollary 8); and (2) For any $n \in
+\omega$, the Tree Property at $\omega_{n+3}$ is consistent with the Chang's
+Conjecture $(\omega_{n+3}, \omega_{n+1}) \twoheadrightarrow (\omega_{n+1},
+\omega_n)$ (Theorem 9).",1506.00158v5
+2015-06-08,Partite Saturation Problems,"We look at several saturation problems in complete balanced blow-ups of
+graphs. We let $H[n]$ denote the blow-up of $H$ onto parts of size $n$ and
+refer to a copy of $H$ in $H[n]$ as 'partite' if it has one vertex in each part
+of $H[n]$. We then ask how few edges a subgraph $G$ of $H[n]$ can have such
+that $G$ has no partite copy of $H$ but such that the addition of any new edge
+from $H[n]$ creates a partite $H$. When $H$ is a triangle this value was
+determined by Ferrara, Jacobson, Pfender, and Wenger. Our main result is to
+calculate this value for $H=K_4$ when $n$ is large. We also give exact results
+for paths and stars and show that for $2$-connected graphs the answer is linear
+in $n$ whilst for graphs which are not $2$-connected the answer is quadratic in
+$n$. We also investigate a similar problem where $G$ is permitted to contain
+partite copies of $H$ but we require that the addition of any new edge from
+$H[n]$ creates an extra partite copy of $H$. This problem turns out to be much
+simpler and we attain exact answers for all cliques and trees.",1506.02445v1
+2015-06-15,The Nuclear Symmetry Energy in Heavy Ion Collisions,"In this contribution I discuss the nuclear symmetry energy in the regime of
+hadronic degrees of freedom. The density dependence of the symmetry energy is
+important from very low densities in supernova explosions, to the structure of
+neutron-rich nuclei around saturation density, and to several times saturation
+density in neutron stars. Heavy ion collisions are the only means to study this
+density dependence in the laboratory. Numerical simulations of transport
+theories are used to extract the equation-of-state, and thus also the symmetry
+energy. I discuss some examples, which relate particularly to the high density
+symmetry energy, which is of particular interest today. I review the status and
+point out some open problems in the determination of the symmetry energy in
+heavy ion collisions.",1506.04687v1
+2015-06-18,Homaloidal nets and ideals of fat points I,"One considers plane Cremona maps with proper base points and the {\em base
+ideal} generated by the linear system of forms defining the map. The object of
+this work is the interweave between the algebraic properties of the base ideal
+and those of the ideal of these points fattened by the virtual multiplicities
+arising from the linear system. One reveals conditions which naturally regulate
+this association, with particular emphasis on the homological side. While most
+classical numerical inequalities concern the three highest virtual
+multiplicities, here one emphasizes also the role of one single highest
+multiplicity. In this vein one describes classes of Cremona maps for large and
+small value of the highest virtual multiplicity. One also deals with the
+delicate property as to when the base ideal is non-saturated and the structure
+of its saturation.",1506.05836v3
+2015-06-22,Neutron star structure in an in-medium modified chiral soliton model,"We study the internal structure of a static and spherically symmetric neutron
+star in the framework of an in-medium modified chiral soliton model. The
+Equations of State describing an infinite and asymmetric nuclear matter are
+obtained introducing the density dependent functions into the low energy free
+space Lagrangian of the model starting from the phenomenology of pionic atoms.
+The parametrizations of density dependent functions are related to the
+properties of isospin asymmetric nuclear systems at saturation density of
+symmetric nuclear matter $\rho_0\simeq 0.16$~fm$^{-3}$. Our results,
+corresponding to the compressibility of symmetric nuclear matter in the range
+$250\,\mbox{MeV}\le K_0\le 270\,\mbox{MeV}$ and the slop parameter value of
+symmetry energy in the range $30\,\mbox{MeV}\le L_S\le 50\,\mbox{MeV}$, are
+consistent with the results from other approaches and with the experimental
+indications. Using the modified Equations of State, near the saturation density
+of symmetric nuclear matter $\rho_0$, the extrapolations to the high density
+and highly isospin asymmetric regions have been performed. The calculations
+showed that the properties of $\sim 1.4M_\odot$ and $\sim 2M_\odot$ neutron
+stars can be well reproduced in the framework of present approach.",1506.06481v1
+2015-06-25,Experimental study of ultracold neutron production in pressurized superfluid helium,"We have investigated experimentally the pressure dependence of the production
+of ultracold neutrons (UCN) in superfluid helium in the range from saturated
+vapor pressure to 20bar. A neutron velocity selector allowed the separation of
+underlying single-phonon and multiphonon pro- cesses by varying the incident
+cold neutron (CN) wavelength in the range from 3.5 to 10{\AA}. The predicted
+pressure dependence of UCN production derived from inelastic neutron scattering
+data was confirmed for the single-phonon excitation. For multiphonon based UCN
+production we found no significant dependence on pressure whereas calculations
+from inelastic neutron scattering data predict an increase of 43(6)% at 20bar
+relative to saturated vapor pressure. From our data we conclude that applying
+pressure to superfluid helium does not increase the overall UCN production rate
+at a typical CN guide.",1506.07785v2
+2015-06-26,Shapes for maximal coverage for two-dimensional random sequential adsorption,"The random sequential adsorption of various particle shapes is studied in
+order to determine the influence of particle anisotropy on the saturated random
+packing. For all tested particles there is an optimal level of anisotropy which
+maximizes the saturated packing fraction. It is found that a concave shape
+derived from a dimer of disks gives a packing fraction of 0.5833, which is
+comparable to the maximum packing fraction of ellipsoids and spherocylinders
+and higher than any other studied shape. Discussion why this shape is so
+beneficial for random sequential adsorption is given.",1506.08164v2
+2015-06-26,Laser stabilization using saturated absorption in a cavity QED system,"We consider the phase stability of a local oscillator (or laser) locked to a
+cavity QED system comprised of atoms with an ultra-narrow optical transition.
+The atoms are cooled to millikelvin temperatures and then released into the
+optical cavity. Although the atomic motion introduces Doppler broadening, the
+standing wave nature of the cavity causes saturated absorption features to
+appear, which are much narrower than the Doppler width. These features can be
+used to achieve an extremely high degree of phase stabilization, competitive
+with the current state-of-the-art. Furthermore, the inhomogeneity introduced by
+finite atomic velocities can cause optical bistability to disappear, resulting
+in no regions of dynamic instability and thus enabling a new regime accessible
+to experiments where optimum stabilization may be achieved.",1506.08210v1
+2015-07-21,Analysis of an offloading scheme for data centers in the framework of fog computing,"In the context of fog computing, we consider a simple case when data centers
+are installed at the edge of the network and assume that if a request arrives
+at an overloaded data center, then it is forwarded to a neighboring data center
+with some probability. Data centers are assumed to have a large number of
+servers and that traffic at some of them is causing saturation. In this case
+the other data centers may help to cope with this saturation regime by
+accepting some of the rejected requests. Our aim is to qualitatively estimate
+the gain achieved via cooperation between neighboring data centers. After
+proving some convergence results, related to the scaling limits of loss
+systems, for the process describing the number of free servers at both data
+centers, we show that the performance of the system can be expressed in terms
+of the invariant distribution of a random walk in the quarter plane. By using
+and developing existing results in the technical literature, explicit formulas
+for the blocking rates of such a system are derived.",1507.05746v2
+2015-07-21,Fluctuations and the rapidity dependence of charged particles spectra in fixed centrality bins in p$A$ collisions,"We argue that large fluctuations in the saturation momentum are necessary to
+explain the ATLAS and ALICE data on pA collisions measured at the LHC. Using a
+form for the distribution of fluctuations motivated by theoretical studies of
+the non-linear evolution equations for the Color Glass Condensate, we find a
+remarkably good agreement between theory and the measured distributions. If the
+saturation momentum fluctuates, we argue that the cross section for a proton
+probe should also fluctuate, consistent with previous observations. Finally we
+discuss these results and their possible consistency with what is known about
+multiplicity fluctuations in such collisions, and attempts to describe the
+ridge effect from properties of the initial state.",1507.05976v2
+2015-07-27,Nuclear matter equation of state from a quark-model nucleon-nucleon interaction,"Starting from a realistic constituent quark model for the nucleon-nucleon
+interaction, we derive the equation of state (EOS) of nuclear matter within the
+Bethe-Brueckner-Goldstone approach up to three-hole-line level, without need to
+introduce three-nucleon forces. To estimate the uncertainty of the calculations
+both the gap and the continuous choices for the single-particle potential are
+considered and compared. The resultant EOS is compatible with the
+phenomenological analysis on the saturation point, the incompressibility, the
+symmetry energy at low density and its slope at saturation, together with the
+high-density pressure extracted from flow data on heavy ion collisions.
+Although the symmetry energy is appreciably larger in the gap choice in the
+high-density region, the maximum neutron star masses derived from the
+continuous-choice EOS and the gap-choice EOS are similar and close to two solar
+masses, which is again compatible with recent observational data. Comparison
+with other microscopic EOS is presented and discussed.",1507.07288v2
+2015-08-17,Universal scaling of the logarithmic negativity in massive quantum field theory,"We consider the logarithmic negativity, a measure of bipartite entanglement,
+in a general unitary 1+1-dimensional massive quantum field theory, not
+necessarily integrable. We compute the negativity between a finite region of
+length $r$ and an adjacent semi-infinite region, and that between two
+semi-infinite regions separated by a distance $r$. We show that the former
+saturates to a finite value, and that the latter tends to zero, as
+$r\rightarrow\infty$. We show that in both cases, the leading corrections are
+exponential decays in $r$ (described by modified Bessel functions) that are
+solely controlled by the mass spectrum of the model, independently of its
+scattering matrix. This implies that, like the entanglement entropy, the
+logarithmic negativity displays a very high level of universality, allowing one
+to extract information about the mass spectrum. Further, a study of sub-leading
+terms shows that, unlike the entanglement entropy, a large-$r$ analysis of the
+negativity allows for the detection of bound states.",1508.04026v2
+2015-08-18,CGC/saturation approach for soft interactions at high energy: long range rapidity correlations,"In this paper we continue our program to build a model for high energy soft
+interactions, that is based on the CGC/saturation approach.The main result of
+this paper is that we have discovered a mechanism that leads to large long
+range rapidity correlations, and results in large values of the correlation
+function $R\Lb y_1,y_2\Rb \,\geq \,1$, which is independent of $y_1$ and $
+y_2$. Such behaviour of the correlation function, provides strong support for
+the idea, that at high energies the system of partons that is produced, is not
+only dense, but also has strong attractive forces acting between the partons.",1508.04236v1
+2015-08-20,Exploring sd-shell nuclei from two- and three-nucleon interactions with realistic saturation properties,"We study ground- and excited-state properties of all sd-shell nuclei with
+neutron and proton numbers 8 <= N,Z <= 20, based on a set of low-resolution
+two- and three-nucleon interactions that predict realistic saturation
+properties of nuclear matter. We focus on estimating the theoretical
+uncertainties due to variation of the resolution scale, the low-energy
+couplings, as well as from the many-body method. The experimental two-neutron
+and two-proton separation energies are reasonably well reproduced, with an
+uncertainty range of about 5 MeV. The first excited 2+ energies also show
+overall agreement, with a more narrow uncertainty range of about 500 keV. In
+most cases, this range is dominated by the uncertainties in the Hamiltonian.",1508.05040v1
+2015-08-27,Density-Dependent Electron Transport and Precise Modeling of GaN HEMTs,"We report on the direct measurement of two-dimensional sheet charge density
+dependence of electron transport in AlGaN/GaN high electron mobility
+transistors. Pulsed IV measurements established increasing electron velocities
+with decreasing sheet charge densities, resulting in saturation velocity of 1.9
+x 10^7 cm/s at a low sheet charge density of 7.8 x 10^11 cm-2. A new optical
+phonon emission-based electron velocity model for GaN is also presented. It
+accommodates stimulated LO phonon emission which clamps the electron velocity
+with strong electron-phonon interaction and long LO phonon lifetime in GaN. A
+comparison with the measured density-dependent saturation velocity shows that
+it captures the dependence rather well. Finally, the experimental result is
+applied in TCAD-based device simulator to predict DC and small signal
+characteristics of a reported GaN HEMT. Good agreement between the simulated
+and reported experimental results validated the measurement presented in this
+report and established accurate modeling of GaN HEMTs.",1508.07050v1
+2015-09-10,Tunneling diodes under environmental effects,"We examine the robustness of single-molecule tunneling diodes to
+thermal-environmental effects. The diode comprises three fragments: two
+different conjugated chemical groups at the boundaries, and a saturated moiety
+in between, breaking conjugation. In this setup, molecular electronic levels
+localized on the conjugated groups independently shift with applied bias. While
+in the forward polarity a resonance condition is met, enhancing conductance, in
+the reversed direction molecular electronic states shift away from each other,
+resulting in small tunneling currents. In the absence of interactions with a
+thermal environment (consisting e.g. internal vibrations, solvent),
+rectification ratios reach three orders of magnitude. We introduce decoherence
+and inelastic-dissipative effects phenomenologically, by using the ""voltage
+probe"" approach. We find that when $\gamma_d \lesssim v$, with $\gamma_d$ the
+interaction energy of electrons with the environment and $v$ the tunneling
+energy across the saturated link, the diode is still highly effective, though
+rectification ratios are cut down by a factor of 2-4 compared to the coherent
+limit. To further enhance rectification ratios in molecular diodes we suggest a
+refined design involving four orbitals, with a pair of closely spaced states at
+each conjugated moiety.",1509.03006v1
+2015-09-13,High-Mobility Holes in Dual-Gated WSe$_2$ Field-Effect Transistors,"We demonstrate dual-gated $p$-type field-effect transistors (FETs) based on
+few-layer tungsten diselenide (WSe$_2$) using high work-function platinum
+source/drain contacts, and a hexagonal boron nitride top-gate dielectric. A
+device topology with contacts underneath the WSe$_2$ results in $p$-FETs with
+$I_{ON}$/$I_{OFF}$ ratios exceeding 10$^7$, and contacts that remain Ohmic down
+to cryogenic temperatures. The output characteristics show current saturation
+and gate tunable negative differential resistance. The devices show intrinsic
+hole mobilities around 140 cm$^2$/Vs at room temperature, and approaching 4,000
+cm$^2$/Vs at 2 K. Temperature-dependent transport measurements show a
+metal-insulator transition, with an insulating phase at low densities, and a
+metallic phase at high densities. The mobility shows a strong temperature
+dependence consistent with phonon scattering, and saturates at low
+temperatures, possibly limited by Coulomb scattering, or defects.",1509.03896v1
+2015-09-22,Black phosphorus mode-locked Er-doped ZBLAN fiber laser at 2.8 um wavelength,"Mid-infrared saturable absorber mirror is successfully fabricated by
+transferring the mechanically exfoliated black phosphorus onto the gold-coated
+mirror. With the as-prepared black phosphorus saturable absorber mirror, a
+continuous-wave passively mode-locked Er:ZBLAN fiber laser is demonstrated at
+the wavelength of 2.8 um, which delivers a maximum average output power of 613
+mW, a repetition rate of 24 MHz and a pulse duration of 42 ps. To the best of
+our knowledge, it is the first time to demonstrate black phosphorus mode-locked
+laser at 2.8 um wavelength. Our results demonstrate the feasibility of black
+phosphorus flake as a new two-dimensional material for application in
+mid-infrared ultrafast photonics.",1509.06479v1
+2015-09-22,Gauge fixing and the gluon propagator in renormalizable xi gauges,"Covariant $R_\xi$ gauge fixing is notoriously difficult for large lattice
+volumes, large $\xi$ and small $N_c$. We thoroughly test different convergence
+techniques, which allows the gauge fixing of lattice configurations with a
+total volume of (3.25 fm)$^4$, up to $\xi=0.5$. We are able to study the gluon
+propagator in the infrared region and its dependence on the gauge fixing
+parameter $\xi$. As expected, the longitudinal gluon dressing functions stay
+constant at their tree-level value $\xi$. Similar to the Landau gauge, the
+transverse $R_\xi$ gauge gluon propagators saturate at a non-vanishing value in
+the deep infrared for all values of $\xi$ studied. We compare with very recent
+continuum studies and perform a simple analysis of the found saturation with a
+dynamically generated effective gluon mass.",1509.06737v1
+2015-09-23,Building prime models in fully good abstract elementary classes,"We show how to build primes models in classes of saturated models of abstract
+elementary classes (AECs) having a well-behaved independence relation:
+  $\mathbf{Theorem.}$
+  Let $K$ be an almost fully good AEC that is categorical in $\text{LS} (K)$
+and has the $\text{LS} (K)$-existence property for domination triples. For any
+$\lambda > \text{LS} (K)$, the class of Galois saturated models of $K$ of size
+$\lambda$ has prime models over every set of the form $M \cup \{a\}$.
+  This generalizes an argument of Shelah, who proved the result when $\lambda$
+is a successor cardinal.",1509.07024v6
+2015-10-05,Sensitive Identification of Nearby Debris Disks via Precise Calibration of WISE Data,"Using data from the WISE All-Sky Survey, we have found >100 new infrared
+excess sources around main-sequence Hipparcos stars within 75pc. Our empirical
+calibration of WISE photospheric colors and removal of non-trivial
+false-positive sources are responsible for the high confidence (>99.5%) of
+detections, while our corrections to saturated W1 (3.4um) and W2 (4.6um)
+photometry have for the first time allowed us to search for new infrared excess
+sources around bright field stars in WISE. The careful calibration and
+filtering of the WISE data have allowed us to probe excess fluxes down to
+roughly 8% of the photospheric emission at 22um around saturated stars in WISE.
+We expect that the increased sensitivity of our survey will not only aid in
+understanding the evolution of debris disks, but will also benefit future
+studies using WISE.",1510.01327v1
+2015-10-12,Formulations of moist thermodynamics for atmospheric modelling,"Internal energy, enthalpy and entropy are the key quantities to study
+thermodynamic properties of the moist atmosphere, because they correspond to
+the First (internal energy and enthalpy) and Second (entropy) Laws of
+thermodynamics. The aim of this chapter is to search for analytical formulas
+for the specific values of enthalpy and entropy and for the moist-air mixture
+composing the atmosphere.
+  The Third Law of thermodynamics leads to the definition of absolute reference
+values for thermal enthalpies and entropies of all atmospheric species. It is
+shown in this Chapter 22 that it is possible to define and compute a general
+moist-air entropy potential temperature, which is really an equivalent of the
+moist-air specific entropy in all circumstances (saturated, or not saturated).
+Similarly, it is shown that it is possible to define and compute the moist-air
+specific enthalpy, which is different from the thermal part of what is called
+Moist-Static-Energy in atmospheric studies.",1510.03239v1
+2015-10-21,On the convective overstability in protoplanetary discs,"This paper explores the driving of low-level hydrodynamical activity in
+protoplanetary-disc dead zones. A small adverse radial entropy gradient,
+ordinarily stabilised by rotation, excites oscillatory convection (`convective
+overstability') when thermal diffusion, or cooling, is neither too strong nor
+too weak. I revisit the linear theory of the instability, discuss its
+prevalence in protoplanetary discs, and show that unstable modes are exact
+nonlinear solutions in the local Boussinesq limit. Overstable modes cannot grow
+indefinitely, however, as they are subject to a secondary parametric
+instability that limits their amplitudes to relatively low levels. If parasites
+set the saturation level of the ensuing turbulence then the convective
+overstability is probably too weak to drive significant angular momentum
+transport or to generate vortices. But I also discuss an alternative, and far
+more vigorous, saturation route that generates radial `layers' or `zonal flows'
+(witnessed also in semiconvection). Numerical simulations are required to
+determine which outcome is favoured in realistic discs, and consequently how
+important the instability is for disc dynamics.",1510.06247v1
+2015-10-25,CGC/saturation approach for soft interactions at high energy: survival probability of the central exclusive production,"We estimate the value of the survival probability for central exclusive
+production, in a model, which is based on the CGC/saturation approach. Hard and
+soft processes are described in the same framework. At LHC energies, we obtain
+a small value for the survival probability. The source of the small value, is
+the impact parameter dependence of the hard amplitude. Our model has
+successfully described a large body of soft data: elastic, inelastic and
+diffractive cross sections,inclusive production and rapidity correlations, as
+well as the $t$-dependence of deep inelastic diffractive production of vector
+mesons",1510.07249v2
+2015-10-30,Saturation in random graphs,"A graph $H$ is $K_s$-saturated if it is a maximal $K_s$-free graph, i.e., $H$
+contains no clique on $s$ vertices, but the addition of any missing edge
+creates one. The minimum number of edges in a $K_s$-saturated graph was
+determined over 50 years ago by Zykov and independently by Erd\H{o}s, Hajnal
+and Moon. In this paper, we study the random analog of this problem: minimizing
+the number of edges in a maximal $K_s$-free subgraph of the Erd\H{o}s-R\'enyi
+random graph $G(n,p)$. We give asymptotically tight estimates on this minimum,
+and also provide exact bounds for the related notion of weak saturation in
+random graphs. Our results reveal some surprising behavior of these parameters.",1510.09187v2
+2015-10-30,"Kato-Nakayama spaces, infinite root stacks, and the profinite homotopy type of log schemes","For a log scheme locally of finite type over $\mathbb{C}$, a natural
+candidate for its profinite homotopy type is the profinite completion of its
+Kato-Nakayama space. Alternatively, one may consider the profinite homotopy
+type of the underlying topological stack of its infinite root stack. Finally,
+for a log scheme not necessarily over $\mathbb{C}$, another natural candidate
+is the profinite \'etale homotopy type of its infinite root stack. We prove
+that, for a fine saturated log scheme locally of finite type over $\mathbb{C}$,
+these three notions agree. In particular, we construct a comparison map from
+the Kato-Nakayama space to the underlying topological stack of the infinite
+root stack, and prove that it induces an equivalence on profinite completions.
+In light of these results, we define the profinite homotopy type of a general
+fine saturated log scheme as the profinite \'etale homotopy type of its
+infinite root stack.",1511.00037v2
+2015-11-02,"Identify influential spreaders in complex networks, the role of neighborhood","Identifying the most influential spreaders is an important issue in
+controlling the spreading processes in complex networks. Centrality measures
+are used to rank node influence in a spreading dynamics. Here we propose a node
+influence measure based on the centrality of a node and its neighbors'
+centrality, which we call the neighborhood centrality. By simulating the
+spreading processes in six real-world networks, we find that the neighborhood
+centrality greatly outperforms the basic centrality of a node such as the
+degree and coreness in ranking node influence and identifying the most
+influential spreaders. Interestingly, we discover a saturation effect in
+considering the neighborhood of a node, which is not the case of the larger the
+better. Specifically speaking, considering the 2-step neighborhood of nodes is
+a good choice that balances the cost and performance. If further step of
+neighborhood is taken into consideration, there is no obvious improvement and
+even decrease in the ranking performance. The saturation effect may be
+informative for studies that make use of the local structure of a node to
+determine its importance in the network.",1511.00441v1
+2015-11-07,Thermodynamic law from the entanglement entropy bound,"From black hole thermodynamics, the Bekenstein bound has been proposed as a
+universal thermal entropy bound. It has been further generalized to an
+entanglement entropy bound which is valid even in a quantum system. In a
+quantumly entangled system, the non-negativity of the relative entropy leads to
+the entanglement entropy bound. When the entanglement entropy bound is
+saturated, a quantum system satisfies the thermodynamics-like law with an
+appropriately defined entanglement temperature. We show that the saturation of
+the entanglement entropy bound accounts for a universal feature of the
+entanglement temperature proportional to the inverse of the system size. In
+addition, we show that the deformed modular Hamiltonian under a global quench
+also satisfies the generalized entanglement entropy boundary after introducing
+a new quantity called the entanglement chemical potential.",1511.02288v2
+2015-11-11,Cluster expansions and chiral symmetry at large density in 2-color QCD,"$SU(N_c)$ lattice gauge theories with $N_f$ flavors of massless staggered
+fermions are considered at high quark chemical potential $\mu$ and any
+temperature $T$. In the strong coupling regime (sufficiently small $\beta$)
+they have been shown to possess a chiral phase of intact global $U(N_f)\times
+U(N_f)$ symmetry. The proof is by cluster expansions which converge in the
+infinite volume limit. Extension to weaker coupling does not appear feasible in
+the presence of complex fermion determinant. For theories with real
+determinant, however, such as 2-color QCD with fundamental fermions, or any
+$N_c$ with even $N_f$ and adjoint fermions, such large $\mu$ cluster expansions
+can be used to show chiral behavior of fermionic lattice observables at any
+gauge coupling. Unfortunately, this absence of color
+superfluidity/superconductivity at high $\mu$ appears to be a lattice artifact
+due to lattice saturation, a serious problem plaguing the standard finite
+density formalism on the lattice. Some possible ways of circumventing
+saturation are discussed.",1511.03733v1
+2015-11-16,Asymptotics of surface-plasmon redshift saturation at sub-nanometric separations,"Many promising nanophotonics endeavours hinge upon the unique plasmonic
+properties of nanometallic structures with narrow non-metallic gaps, which
+support super-concentrated bonding modes that singularly redshift with
+decreasing separations. In this letter, we present a descriptive physical
+picture, complemented by elementary asymptotic formulae, of a nonlocal
+mechanism for plasmon-redshift saturation at subnanometric gap widths. Thus, by
+considering the electron-charge and field distributions in the close vicinity
+of the metal-vacuum interface, we show that nonlocality is asymptotically
+manifested as an effective potential discontinuity. For bonding modes in the
+near-contact limit, the latter discontinuity is shown to be effectively
+equivalent to a widening of the gap. As a consequence, the resonance-frequency
+near-contact asymptotics are a renormalisation of the corresponding local ones.
+Specifically, the renormalisation furnishes an asymptotic plasmon-frequency
+lower bound that scales with the $1/4$-power of the Fermi wavelength. We
+demonstrate these remarkable features in the prototypical cases of nanowire and
+nanosphere dimers, showing agreement between our elementary expressions and
+previously reported numerical computations.",1511.04895v1
+2015-11-24,Leptons from heavy-quark semileptonic decay in pA collisions within the CGC framework,"We study single lepton production from semileptonic decays of heavy flavor
+hadrons ($D,B\rightarrow~l$) in pp and p$A$ collisions at RHIC and the LHC
+within the saturation/Color-Glass-Condensate (CGC) framework. Using the gluon
+distribution function obtained with the dipole amplitude, whose energy
+dependence is described by the Balitsky-Kovchegov equation with running
+coupling effect, we compute the transverse-momentum ($p_\perp$) spectra of the
+lepton yields at mid and forward rapidities. We find that a large fraction of
+leptons at low $p_\perp$ stems from the saturation regime of the incoming
+gluons in the target, especially in p$A$ collisions at the LHC. The resultant
+$p_\perp$ spectra is slightly harder than the data, but the nuclear
+modification factor seems consistent with the data within some uncertainty. We
+also update the nuclear modification factors for J/$\psi$ and $D$ meson at the
+LHC energy.",1511.07698v4
+2015-11-24,Signal Processing and Electronic Noise in LZ,"The electronics of the LUX-ZEPLIN (LZ) experiment, the 10-tonne dark matter
+detector to be installed at the Sanford Underground Research Facility (SURF),
+consists of low-noise dual-gain amplifiers and a 100-MHz, 14-bit data
+acquisition system for the TPC PMTs. Pre-prototypes of the analog amplifiers
+and the 32-channel digitizers were tested extensively with simulated pulses
+that are similar to the prompt scintillation light and the electroluminescence
+signals expected in LZ. These studies are used to characterize the noise and to
+measure the linearity of the system. By increasing the amplitude of the test
+signals, the effect of saturating the amplifier and the digitizers was studied.
+The RMS ADC noise of the digitizer channels was measured to be 1.19 $\pm$ 0.01
+ADCC. When a high-energy channel of the amplifier is connected to the
+digitizer, the measured noise remained virtually unchanged, while the noise
+added by a low-energy channel was estimated to be 0.38 $\pm$ 0.02 ADCC (46
+$\pm$ 2$\mu$V). A test facility is under construction to study saturation,
+mitigate noise and measure the performance of the LZ electronics and data
+acquisition chain.",1511.07752v1
+2015-11-29,Probing electronic lifetimes and phonon anharmonicities in high-quality chemical vapor deposited graphene by magneto-Raman spectroscopy,"We present a magneto-Raman study on high-quality single-layer graphene grown
+by chemical vapor deposition (CVD) that is fully encapsulated in hexagonal
+boron nitride by a dry transfer technique. By analyzing the Raman D, G, and 2D
+peaks, we find that the structural quality of the samples is comparable to
+state-of-the-art exfoliated graphene flakes. From B field dependent Raman
+measurements, we extract the broadening and associated lifetime of the G peak
+due to anharmonic effects. Furthermore, we determine the decay width and
+lifetime of Landau level (LL) transitions from magneto-phonon resonances as a
+function of laser power. At low laser power, we find a minimal decay width of
+140 1/cm highlighting the high electronic quality of the CVD-grown graphene. At
+higher laser power, we observe an increase of the LL decay width leading to a
+saturation with the corresponding lifetime saturating at a minimal value of 18
+fs.",1511.08984v1
+2015-12-13,Čerenkov free-electron laser in side-wall configuration,"In this paper, we have proposed a \v{C}erenkov free-electron laser (CFEL)
+with metallic side walls, which are used to confine an electromagnetic surface
+mode supported by a thin dielectric slab placed on top of a conducting surface.
+This leads to an enhancement in coupling between the optical mode and the
+co-propagating electron beam, and consequently, performance of the CFEL is
+improved. We set up coupled Maxwell-Lorentz equations for the system, in
+analogy with an undulator based conventional FEL, and obtain formulas for the
+small-signal gain and growth rate. It is shown that small signal gain and
+growth rate in this configuration are larger compared to the configuration
+without the side walls. In the nonlinear regime, we solve the coupled
+Maxwell-Lorentz equations numerically and study the saturation behaviour of the
+system. It is found that the \v{C}erenkov FEL with side walls saturates
+quickly, and produces powerful coherent terahertz radiation.",1512.04022v2
+2015-12-28,A convergent mass conservative numerical scheme based on mixed finite elements for two-phase flow in porous media,"In this work we present a mass conservative numerical scheme for two-phase
+flow in porous media. The model for flow consists on two fully coupled,
+non-linear equations: a degenerate parabolic equation and an elliptic equation.
+The proposed numerical scheme is based on backward Euler for the temporal
+discretization and mixed finite element method (MFEM) for the discretization in
+space. Continuous, semi-discrete (continuous in space) and fully discrete
+variational formulations are set up and the existence and uniqueness of
+solutions is discussed. Error estimates are presented to prove the convergence
+of the scheme. The non-linear systems within each time step are solved by a
+robust linearization method. This iterative method does not involve any
+regularization step. The convergence of the linearization scheme is rigorously
+proved under the assumption of a Lipschitz continuous saturation. The case of a
+H\""older continuous saturation is also discussed, a rigorous convergence proof
+being given for Richards' equation. Numerical results are presented to sustain
+the theoretical findings.",1512.08387v2
+2015-12-29,Extended anti-de Sitter Hypergravity in $2+1$ Dimensions and Hypersymmetry Bounds,"In a recent paper (JHEP {\bf 1508} (2015) 021), we have investigated
+hypersymmetry bounds in the context of simple anti-de Sitter hypergravity in
+$2+1$ dimensions. We showed that these bounds involved non linearly the
+spin-$2$ and spin-$4$ charges, and were saturated by a class of extremal black
+holes, which are $\frac14$-hypersymmetric. We continue the analysis here by
+considering $(M,N)$-extended anti-de Sitter hypergravity models, based on the
+superalgebra $osp(M \vert 4) \oplus osp(N \vert 4)$. The asymptotic symmetry
+superalgebra is then the direct sum of two-copies of a $W$-superalgebra that
+contains $so(M)$ (or $so(N)$) Kac-Moody currents of conformal weight $1$,
+fermionic generators of conformal weight $5/2$ and bosonic generators of
+conformal weight $4$ in addition to the Virasoro generators. The nonlinear
+hypersymmetry bounds on the conserved charges are derived and shown to be
+saturated by a class of extreme hypersymmetric black holes which we explicitly
+construct.",1512.08603v1
+2015-12-29,Characterization of the GEM foil materials,"Systematic studies on the GEM foil material are performed to measure the
+moisture diffusion rate and saturation level. These studies are important
+because the presence of this compound inside the detector's foil can possibly
+change its mechanical and electrical properties and, in such a way, the
+detector performance can be affected. To understand this phenomenon, a model is
+developed with COMSOL Multhiphysics v. 4.3, which described the adsorption and
+diffusion within the geometry of GEM foil, the concentration profiles and the
+time required to saturate the foil. The COMSOL model is verified by
+experimental observations on a GEM foil sample. This note will describe the
+model and its experimental verification results.",1512.08621v1
+2016-01-11,Terahertz Saturable Absorption in Superconducting Metamaterials,"We present a superconducting metamaterial saturable absorber at terahertz
+frequencies. The absorber consists of an array of split ring resonators (SRRs)
+etched from a 100nm YBaCu3O7 (YBCO) film. A polyimide spacer layer and gold
+ground plane are deposited above the SRRs, creating a reflecting perfect
+absorber. Increasing either the temperature or incident electric field (E)
+decreases the superconducting condensate density and corresponding kinetic
+inductance of the SRRs. This alters the impedance matching in the metamaterial,
+reducing the peak absorption. At low electric fields, the absorption was
+optimized near 80% at T=10K and decreased to 20% at T=70K. For E=40kV/cm and
+T=10K, the peak absorption was 70% decreasing to 40% at 200kV/cm, corresponding
+to a modulation of 43%.",1601.02496v2
+2016-01-17,Metallic ferromagnetism supported by a single band in a multi-band Hubbard model,"We construct a multi-band Hubbard model on the lattice obtained by
+""decorating"" a closely packed $d$-dimensional lattice $\mathcal{M}$ (such as
+the triangular lattice) where $d\ge2$. We take the limits in which the Coulomb
+interaction and the band gap become infinitely large. Then there remains only a
+single band with finite energy, on which electrons are supported. Let the
+electron number be $N_\mathrm{e}=|\mathcal{M}|-N_\mathrm{h}$, where
+$|\mathcal{M}|$ corresponds to the electron number which makes the lowest
+(finite energy) band half-filled, and $N_\mathrm{h}$ is the number of ""holes"".
+It is expected that the model exhibits metallic ferromagnetism if
+$N_\mathrm{h}/|\mathcal{M}|$ is nonvanishing but sufficiently small. We prove
+that the ground states exhibit saturated ferromagnetism if
+$N_\mathrm{h}\le(\text{const.})|\mathcal{M}|^{2/(d+2)}$, and exhibit (not
+necessarily saturated) ferromagnetism if
+$N_\mathrm{h}\le(\mathrm{const.})|\mathcal{M}|^{(d+1)/(d+2)}$. This may be
+regarded as a rigorous example of metallic ferromagnetism provided that the
+system size $|\mathcal{M}|$ is not too large.",1601.04265v2
+2016-01-21,Interference and dynamics of light from a distance-controlled atom pair in an optical cavity,"Interference is central to quantum physics and occurs when indistinguishable
+paths exist, like in a double-slit experiment. Replacing the two slits with two
+single atoms introduces optical non-linearities for which nontrivial
+interference phenomena are predicted. Their observation, however, has been
+hampered by difficulties in preparing the required atomic distribution,
+controlling the optical phases and detecting the faint light. Here we overcome
+all of these experimental challenges by combining an optical lattice for atom
+localisation, an imaging system with single-site resolution, and an optical
+resonator for light steering. We observe resonator-induced saturation of
+resonance fluorescence for constructive interference of the scattered light and
+nonzero emission with huge photon bunching for destructive interference. The
+latter is explained by atomic saturation and photon pair generation. Our
+experimental setting is scalable and allows one to realize the Tavis-Cummings
+model for any number of atoms and photons, explore fundamental aspects of
+light-matter interaction, and implement new quantum information processing
+protocols.",1601.05757v1
+2016-01-25,On the fractional cell kill law governing the lysis of solid tumors,"We present in silico simulations and mathematical analyses supporting several
+hypotheses that explain the saturation expressed in the fractional cell kill
+law that governs the lysis of tumor cells by cytotoxic CD8 + T cells (CTLs). In
+order to give insight into the significance of the parameters appearing in such
+law, a hybrid cellular automaton model describing the spatio-temporal evolution
+of tumor growth and its interaction with the cell-mediated immune response is
+used. When the CTLs eradicate efficiently the tumor cells, the model predicts a
+correlation between the morphology of the tumors and the rate at which they are
+lysed. As the effectiveness of the effector cells is decreased, the saturation
+gradually disappears. This limit is thoroughly discussed and a new fractional
+cell kill is proposed.",1601.07144v3
+2016-02-04,Noisy Metrology: A saturable lower bound on quantum Fisher information,"In order to provide a guaranteed precision and a more accurate judgement
+about the true value of the Cram\'{e}r-Rao bound and its scaling behavior, an
+upper bound (equivalently a lower bound on the quantum Fisher information) for
+precision of estimation is introduced. Unlike the bounds previously introduced
+in the literature, the upper bound is saturable and yields a practical
+instruction to estimate the parameter through preparing the optimal initial
+state and optimal measurement. The bound is based on the underling dynamics and
+its calculation is straightforward and requires only the matrix representation
+of the quantum maps responsible for encoding the parameter. This allows us to
+apply the bound to open quantum systems whose dynamics are described by either
+semigroup or non-semigroup maps. Reliability and efficiency of the method to
+predict the ultimate precision limit are demonstrated by {three} main examples.",1602.01691v5
+2016-02-04,Twist expansion of forward Drell-Yan process,"We present a twist expansion of differential cross-sections of the forward
+Drell-Yan process at the high energies. The expansion of all invariant
+form-factors is performed assuming GBW saturation model and the saturation
+scale plays the role of the hadronic scale of OPE. Some expilicit predictions
+for LHC experiments are given. It is shown also how the Lam-Tung relation is
+broken at twist 4 what provides a sensitive probe for searching of higher
+twists.",1602.01762v2
+2016-02-18,Spread of entanglement for small subsystems in holographic CFTs,"We develop an analytic perturbative expansion to study the propagation of
+entanglement entropy for small subsystems after a global quench, in the context
+of the AdS/CFT correspondence. Opposite to the large interval limit, in this
+case the evolution of the system takes place at timescales that are shorter in
+comparison to the local equilibration scale and thus, different physical
+mechanisms govern the dynamics and subsequent thermalization. In particular, we
+show that the heuristic picture in terms of a ""entanglement tsunami"" does not
+apply in this regime. We find two crucial differences. First, that the
+instantaneous rate of growth of the entanglement is not constrained by
+causality, but rather its time average. And second, that the approach to
+saturation is always continuous, regardless the shape of the entangling
+surface. Our analytic expansion also enables us to verify some previous
+numerical results, namely, that the saturation time is non-monotonic with
+respect to the chemical potential. All of our results are pertinent to CFTs
+with a classical gravity dual formulation.",1602.05934v2
+2016-02-29,Proof of Control of a UAV and a UGV Cooperating to Manipulate an Object,"This paper focuses on the control of a system composed of an Unmanned Aerial
+Vehicle (UAV) and an Unmanned Ground Vehicle (UGV) which cooperate to
+manipulate an object. The two units are subject to actuator saturations and
+cooperate to move the object to a desired pose, characterized by its position
+and inclination. The paper proposes a control strategy where the ground vehicle
+is tasked to deploy the object to a certain position, whereas the aerial
+vehicle adjusts its inclination. The ground vehicle is governed by a saturated
+proportional-derivative control law. The aerial vehicle is regulated by means
+of a cascade control specifically designed for this problem that is able to
+exploit the mechanical interconnection. The stability of the overall system is
+proved through Input-to-State Stability and Small Gain theorem arguments. To
+solve the problem of constraints satisfaction, a nonlinear Reference Governor
+scheme is implemented. Numerical simulations are provided to demonstrate the
+effectiveness of the proposed method.",1602.08987v2
+2016-03-06,Proof of Threshold Saturation for Spatially Coupled Sparse Superposition Codes,"Recently, a new class of codes, called sparse superposition or sparse
+regression codes, has been proposed for communication over the AWGN channel. It
+has been proven that they achieve capacity using power allocation and various
+forms of iterative decoding. Empirical evidence has also strongly suggested
+that the codes achieve capacity when spatial coupling and approximate message
+passing decoding are used, without need of power allocation. In this note we
+prove that state evolution (which tracks message passing) indeed saturates the
+potential threshold of the underlying code ensemble, which approaches in a
+proper limit the optimal threshold. Our proof uses ideas developed in the
+theory of low-density parity-check codes and compressive sensing.",1603.01817v1
+2016-03-07,Graph Theoretic Investigations on Inefficiencies in Network Models,"We consider network models where information items flow %are sent from a
+source to a sink node. We start with a model where routing is constrained by
+energy available on nodes in finite supply (like in Smartdust) and efficiency
+is related to energy consumption. We characterize graph topologies ensuring
+that every saturating flow under every energy-to-node assignment is maximum and
+provide a polynomial-time algorithm for checking this property. We then
+consider the standard flow networks with capacity on edges, where again
+efficiency is related to maximality of saturating flows, and a traffic model
+for selfish routing, where efficiency is related to latency at a Wardrop
+equilibrium. Finally, we show that all these forms of inefficiency yield
+different classes of graphs (apart from the acyclic case, where the last two
+forms generate the same class). Interestingly, in all cases inefficient graphs
+can be made efficient by removing edges; this resembles a well-known
+phenomenon, called Braess's paradox.",1603.01983v2
+2016-03-14,Saturation of repeated quantum measurements,"We study sequential measurement scenarios where the system is repeatedly
+subjected to the same measurement process. We first provide examples of such
+repeated measurements where further repetitions of the measurement do not
+increase our knowledge on the system after some finite number of measurement
+steps. We also prove, however, that repeating the L\""uders measurement of an
+unsharp two-outcome observable never saturates in this sense, and we
+characterize the observable measured in the limit of infinitely many
+repetitions. Our result implies that a repeated measurement can be used to
+correct the inherent noise of an unsharp observable.",1603.04271v2
+2016-03-15,Threshold Saturation of Spatially Coupled Sparse Superposition Codes for All Memoryless Channels,"We recently proved threshold saturation for spatially coupled sparse
+superposition codes on the additive white Gaussian noise channel. Here we
+generalize our analysis to a much broader setting. We show for any memoryless
+channel that spatial coupling allows generalized approximate message-passing
+(GAMP) decoding to reach the potential (or Bayes optimal) threshold of the code
+ensemble. Moreover in the large input alphabet size limit: i) the GAMP
+algorithmic threshold of the underlying (or uncoupled) code ensemble is simply
+expressed as a Fisher information; ii) the potential threshold tends to
+Shannon's capacity. Although we focus on coding for sake of coherence with our
+previous results, the framework and methods are very general and hold for a
+wide class of generalized estimation problems with random linear mixing.",1603.04591v1
+2016-03-19,Efficiency enhancement of a harmonic lasing free-electron laser,"The harmonic lasing free-electron laser amplifier, in which two wigglers is
+employed in order for the fundamental resonance of the second wiggler to
+coincide with the third harmonic of the first wiggler to generate ultraviolet
+radiation, is studied. A set of coupled nonlinear first-order differential
+equations describing the nonlinear evolution of the system, for a long electron
+bunch, is solved numerically by CYRUS code. Solutions for the non-averaged and
+averaged equations are compared. Remarkable agreement is found between the
+averaged and non-averaged simulation for the evolution of the third harmonic.
+Thermal effects in the form of longitudinal velocity spread are also
+investigated. For efficiency enhancement, the second wiggler field is set to
+decrease linearly and nonlinearly at the point where the radiation of the third
+harmonic saturates. The optimum starting point and the slope of the tapering of
+the amplitude of the wiggler are found by a successive run of the code. It is
+found that tapering can increase the saturated power of the third harmonic
+considerably. In order to reduce the length of the wiggler, the prebunched
+electron beam is considered.",1603.06031v1
+2016-03-21,Model-Independent Inference of Neutron Star Radii from Moment of Inertia Measurements,"A precise moment of inertia measurement for PSR J0737-3039A in the double
+pulsar system is expected within the next five years. We present here a new
+method of mapping the anticipated measurement of the moment of inertia directly
+into the neutron star structure. We determine the maximum and minimum values
+possible for the moment of inertia of a neutron star of a given radius based on
+physical stability arguments, assuming knowledge of the equation of state only
+at densities below the nuclear saturation density. If the equation of state is
+trusted up to the nuclear saturation density, we find that a measurement of the
+moment of inertia will place absolute bounds on the radius of PSR J0737-3039A
+to within $\pm$1 km. The resulting combination of moment of inertia, mass, and
+radius measurements for a single source will allow for new, stringent
+constraints on the dense-matter equation of state.",1603.06594v2
+2016-04-13,Quasi-geostrophic dynamics in the presence of moisture gradients,"The derivation of a quasi-geostrophic (QG) system from the rotating shallow
+water equations on a midlatitude beta-plane coupled with moisture is presented.
+Condensation is prescribed to occur whenever the moisture at a point exceeds a
+prescribed saturation value. It is seen that a slow condensation time scale is
+required to obtain a consistent set of equations at leading order. Further,
+since the advecting wind fields are geostrophic, changes in moisture (and
+hence, precipitation) occur only via non-divergent mechanisms. Following
+observations, a saturation profile with gradients in the zonal and meridional
+directions is prescribed. A purely meridional gradient has the effect of
+slowing down the dry Rossby waves, through a reduction in the ""equivalent
+gradient"" of the background potential vorticity. A large scale unstable moist
+mode results on the inclusion of a zonal gradient by itself, or in conjunction
+with a meridional moisture gradient. For gradients that are are representative
+of the atmosphere, the most unstable moist mode propagates zonally in the
+direction of increasing moisture, matures over an intraseasonal timescale and
+has small phase speed.",1604.03656v1
+2016-04-17,A numerical study of two-phase flow with dynamic capillary pressure using an adaptive moving mesh method,"Motivated by observations of saturation overshoot, this paper investigates
+numerical modeling of two-phase flow incorporating dynamic capillary pressure.
+The effects of the dynamic capillary coefficient, the infiltrating flux rate
+and the initial and boundary values are systematically studied using a
+travelling wave ansatz and efficient numerical methods. The travelling wave
+solutions may exhibit monotonic, non-monotonic or plateau-shaped behaviour.
+Special attention is paid to the non-monotonic profiles. The travelling wave
+results are confirmed by numerically solving the partial differential equation
+using an accurate adaptive moving mesh solver. Comparisons between the computed
+solutions using the Brooks-Corey model and the laboratory measurements of
+saturation overshoot verify the effectiveness of our approach.",1604.04863v1
+2016-04-23,Micro-mechanical Failure Analysis of Wet Granular Matter,"We employ a novel fluid-particle model to study the shearing behavior of
+granular soils under different saturation levels, ranging from the dry material
+via the capillary bridge regime to higher saturation levels with percolating
+clusters. The full complexity of possible liquid morphologies is taken into
+account, implying the formation of isolated arbitrary-sized liquid clusters
+with individual Laplace pressures that evolve by liquid exchange via films on
+the grain surface. Liquid clusters can grow in size, shrink, merge and split,
+depending on local conditions, changes of accessible liquid and the pore space
+morphology determined by the granular phase. This phase is represented by a
+discrete particle model based on Contact Dynamics, where capillary forces
+exerted from a liquid phase add to the motion of spherical particles. We study
+the macroscopic response of the system due to an external compression force at
+various liquid contents with the help of triaxial shear tests. Additionally,
+the change in liquid cluster distributions during the compression due to the
+deformation of the pore space is evaluated close to the critical load.",1604.06881v1
+2016-04-26,Saturation and solvability in abstract elementary classes with amalgamation,"$\mathbf{Theorem.}$
+  Let $K$ be an abstract elementary class (AEC) with amalgamation and no
+maximal models. Let $\lambda > \text{LS} (K)$. If $K$ is categorical in
+$\lambda$, then the model of cardinality $\lambda$ is Galois-saturated.
+  This answers a question asked independently by Baldwin and Shelah. We deduce
+several corollaries: $K$ has a unique limit model in each cardinal below
+$\lambda$, (when $\lambda$ is big-enough) $K$ is weakly tame below $\lambda$,
+and the thresholds of several existing categoricity transfers can be improved.
+  We also prove a downward transfer of solvability (a version of superstability
+introduced by Shelah):
+  $\mathbf{Corollary.}$
+  Let $K$ be an AEC with amalgamation and no maximal models. Let $\lambda > \mu
+> \text{LS} (K)$. If $K$ is solvable in $\lambda$, then $K$ is solvable in
+$\mu$.",1604.07743v3
+2016-05-10,Creation and counting of defects in a temperature quenched Bose-Einstein Condensate,"We study the spontaneous formation of defects in the order parameter of a
+trapped ultracold bosonic gas while crossing the critical temperature for
+Bose-Einstein Condensation (BEC) at different rates. The system has the shape
+of an elongated ellipsoid, whose transverse width can be varied to explore
+dimensionality effects. For slow enough temperature quenches we find a
+power-law scaling of the average defect number with the quench rate, as
+predicted by the Kibble-Zurek mechanism. A breakdown of such a scaling is found
+for fast quenches, leading to a saturation of the average defect number. We
+suggest an explanation for this saturation in terms of the mutual interactions
+among defects.",1605.02982v1
+2016-05-12,Effects of symmetry energy in $^{132}\rm {Sn}+^{124}\rm {Sn}$ reaction at 300 MeV/nucleon,"Based on the recently updated Isospin-dependent Boltzmann-Uehling-Uhlenbeck
+(IBUU) transport model, we studied the effects of symmetry energy on the
+neutron to proton n/p ratio and the $\pi^{-}/\pi^{+}$ ratio in central
+$^{132}\rm {Sn}+^{124}\rm {Sn}$ reaction at 300 MeV/nucleon. It is found that
+the n/p ratio and the $\pi^{-}/\pi^{+}$ ratio in central $^{132}\rm
+{Sn}+^{124}\rm {Sn}$ reaction at 300 MeV/nucleon mainly probe the symmetry
+energy in the density region 1-1.5 times saturation density. However, the
+$\pi^{-}/\pi^{+}$ ratio may be able to probe the density-dependent symmetry
+energy above 1.5 times saturation density by making some kinematic restrictions
+such as the azimuthal angle and kinetic energy cuts of emitting pions.",1605.03701v2
+2016-05-13,Bayesian $D$-optimal designs for error-in-variables models,"Bayesian optimality criteria provide a robust design strategy to parameter
+misspecification. We develop an approximate design theory for Bayesian
+$D$-optimality for non-linear regression models with covariates subject to
+measurement errors. Both maximum likelihood and least squares estimation are
+studied and explicit characterisations of the Bayesian $D$-optimal saturated
+designs for the Michaelis-Menten, Emax and exponential regression models are
+provided. Several data examples are considered for the case of no preference
+for specific parameter values, where Bayesian $D$-optimal saturated designs are
+calculated using the uniform prior and compared to several other designs,
+including the corresponding locally $D$-optimal designs, which are often used
+in practice.",1605.04055v1
+2016-05-14,Highly anisotropic electronic transport properties of monolayer and bilayer phosphorene from first principles,"The intrinsic carrier transport dynamics in phosphorene is theoretically
+examined. Utilizing a density functional theory treatment, the low-field
+mobility and the saturation velocity are characterized for both electrons and
+holes in the monolayer and bilayer structures. The analysis clearly elucidates
+the crystal orientation dependence manifested through the anisotropic band
+structure and the carrier-phonon scattering rates. In the monolayer, the hole
+mobility in the armchair direction is estimated to be approximately five times
+larger than in the zigzag direction at room temperature (460 cm$^2$/Vs vs. 90
+cm$^2$/Vs). The bilayer transport, on the other hand, exhibits a more modest
+anisotropy with substantially higher mobilities (1610 cm$^2$/Vs and 760
+cm$^2$/Vs, respectively). The calculations on the conduction-band electrons
+indicate a comparable dependence while the characteristic values are generally
+smaller by about a factor of two. The variation in the saturation velocity is
+found to be less pronounced. With the anticipated superior performance and the
+diminished anisotropy, few-layer phosphorene offers a promising opportunity
+particularly in p-type applications.",1605.04377v1
+2016-05-25,Extremal bootstrapping: go with the flow,"The extremal functional method determines approximate solutions to the
+constraints of crossing symmetry, which saturate bounds on the space of unitary
+CFTs. We show that such solutions are characterized by extremality conditions,
+which may be used to flow continuously along the boundaries of parameter space.
+Along the flow there is generically no further need for optimization, which
+dramatically reduces computational requirements, bringing calculations from the
+realm of computing clusters to laptops. Conceptually, extremality sheds light
+on possible ways to bootstrap without positivity, extending the method to
+non-unitary theories, and implies that theories saturating bounds, and
+especially those sitting at kinks, have unusually sparse spectra. We discuss
+several applications, including the first high-precision bootstrap of a
+non-unitary CFT.",1605.08087v1
+2016-05-30,Doppler-free spectroscopy on Cs D$_1$ line with a dual-frequency laser,"We report on Doppler-free laser spectroscopy in a Cs vapor cell using a
+dual-frequency laser system tuned on the Cs D$_1$ line. Using
+counter-propagating beams with crossed linear polarizations, an original
+sign-reversal of the usual saturated absorption dip and large increase in
+Doppler-free atomic absorption is observed. This phenomenon is explained by
+coherent population trapping (CPT) effects. The impact of laser intensity and
+light polarization on absorption profiles is reported in both single-frequency
+and dual-frequency regimes. In the latter, frequency stabilization of two diode
+lasers was performed, yielding a beat-note fractional frequency stability at
+the level of $3 \times 10^{-12}$ at 1 s averaging time. These performances are
+about an order of magnitude better than those obtained using a conventional
+single-frequency saturated absorption scheme.",1605.09245v1
+2016-04-28,A Mathematical Model of the Rainwater Flows in a Green Roof,"A model is presented for the gravity-driven flow of rainwater descending
+through the soil layer of a green roof, treated as a porous medium on a flat
+permeable surface representing an efficient drainage layer. A fully saturated
+zone is shown to occur. It is typically a thin layer, relative to the total
+soil thickness, and lies at the bottom of the soil layer. This provides a
+bottom boundary condition for the partially saturated upper zone. It is shown
+that after the onset of rainfall, well-defined fronts of water can descend
+through the soil layer. Also the rainwater flow is relatively quick compared
+with the moisture uptake by the roots of the plants in the roof. In separate
+models the exchanges of water are described between the (smaller-scale) porous
+granules of soil, the roots and the rainwater in the inter-granule pores.",1605.09727v1
+2016-05-31,Rigid ideals,"An ideal $I$ on a cardinal $\kappa$ is called \emph{rigid} if all
+automorphisms of $P(\kappa)/I$ are trivial. An ideal is called
+\emph{$\mu$-minimal} if whenever $G\subseteq P(\kappa)/I$ is generic and $X\in
+P(\mu)^{V[G]}\setminus V$, it follows that $V[X]=V[G]$. We prove that the
+existence of a rigid saturated $\mu$-minimal ideal on $\mu^+$, where $\mu$ is a
+regular cardinal, is consistent relative to the existence of large cardinals.
+The existence of such an ideal implies that GCH fails. However, we show that
+the existence of a rigid saturated ideal on $\mu^+$, where $\mu$ is an
+\emph{uncountable} regular cardinal, is consistent with GCH relative to the
+existence of an almost-huge cardinal. Addressing the case $\mu=\omega$, we show
+that the existence of a rigid \emph{presaturated} ideal on $\omega_1$ is
+consistent with CH relative to the existence of an almost-huge cardinal. The
+existence of a \emph{precipitous} rigid ideal on $\mu^+$ where $\mu$ is an
+uncountable regular cardinal is equiconsistent with the existence of a
+measurable cardinal.",1606.00040v2
+2016-06-02,Matrix Product Density Operators: Renormalization Fixed Points and Boundary Theories,"We consider the tensors generating matrix product states and density
+operators in a spin chain. For pure states, we revise the renormalization
+procedure introduced by F. Verstraete et al. in 2005 and characterize the
+tensors corresponding to the fixed points. We relate them to the states
+possessing zero correlation length, saturation of the area law, as well as to
+those which generate ground states of local and commuting Hamiltonians. For
+mixed states, we introduce the concept of renormalization fixed points and
+characterize the corresponding tensors. We also relate them to concepts like
+finite correlation length, saturation of the area law, as well as to those
+which generate Gibbs states of local and commuting Hamiltonians. One of the
+main result of this work is that the resulting fixed points can be associated
+to the boundary theories of two-dimensional topological states, through the
+bulk-boundary correspondence introduced by Cirac et al. in 2011.",1606.00608v3
+2016-06-14,Normal-metal quasiparticle traps for superconducting qubits,"The presence of quasiparticles in superconducting qubits emerges as an
+intrinsic constraint on their coherence. While it is difficult to prevent the
+generation of quasiparticles, keeping them away from active elements of the
+qubit provides a viable way of improving the device performance. Here we
+develop theoretically and validate experimentally a model for the effect of a
+single small trap on the dynamics of the excess quasiparticles injected in a
+transmon-type qubit. The model allows one to evaluate the time it takes to
+evacuate the injected quasiparticles from the transmon as a function of trap
+parameters. With the increase of the trap size, this time decreases
+monotonically, saturating at the level determined by the quasiparticles
+diffusion constant and the qubit geometry. We determine the characteristic trap
+size needed for the relaxation time to approach that saturation value.",1606.04591v1
+2016-06-29,New correlations between viscosity and surface tension for saturated normal fluids,"New correlations between viscosity and surface tension are proposed and
+checked for saturated normal fluids. The proposed correlations contain three or
+four adjustable coefficients for every fluid. They were obtained by fitting 200
+data points, ranging from the triple point to a point very near to the critical
+one. Forty substances were considered, including simple fluids (such as rare
+gases), simple hydrocarbons, refrigerants, and some other substances such as
+carbon dioxide and water. Two correlation models with three adjustable
+coefficients were checked, and the results showed that the one based on the
+modified Pelofsky expression gives the better overall results. A new
+4-coefficient correlation is then proposed which clearly improves the results,
+giving the lowest overall deviations for 32 out of the 40 substances considered
+and absolute average deviations below 10% for all of them.",1606.09105v1
+2016-06-29,Improved Correlation for Viscosity from Surface Tension Data for Saturated Normal Fluids,"Several correlations between viscosity and surface tension for saturated
+normal fluids have been proposed in the literature. Usually, they include three
+or four adjustable coefficients for every fluid and give generally good
+results. In this paper we propose a new and improved four-coefficient
+correlation which was obtained by fitting data ranging from the triple point to
+a point very near to the critical one. Fifty four substances were considered,
+including simple fluids (such as rare gases), simple hydrocarbons,
+refrigerants, and some other substances such as carbon dioxide, water or
+ethanol. The new correlation clearly improves the results obtained with those
+previously available since it gives absolute average deviations below1% for 40
+substances and below 2.1% for 10 substances more.",1606.09108v1
+2016-06-30,Does Your DNS Recursion Really Time Out as Intended? A Timeout Vulnerability of DNS Recursive Servers,"Parallelization is featured by DNS recursive servers to do time-consuming
+recursions on behalf on clients. As common DNS configurations, recursive
+servers should allow a reasonable timeout for each recursion which may take as
+long as several seconds. However, it is proposed in this paper that recursion
+parallelization may be exploited by attackers to compromise the recursion
+timeout mechanism for the purpose of DoS or DDoS attacks. Attackers can have
+recursive servers drop early existing recursions in service by saturating
+recursion parallelization. The key of the proposed attack model is to reliably
+prolong service times for any attacking queries. As means of prolong service
+times, serval techniques are proposed to effectively avoiding cache hit and
+prolonging overall latency of external DNS lookups respectively. The impacts of
+saturated recursion parallelization on timeout are analytically provided. The
+testing on BIND servers demonstrates that with carefully crafted queries, an
+attacker can use a low or moderate level of query load to successfully
+overwhelm a target recursive server from serving the legitimate clients.",1607.00269v2
+2016-07-08,Mass ordering of spectra from fragmentation of saturated gluon states in high multiplicity proton-proton collisions,"The mass ordering of mean transverse momentum $\left<p_T\right>$ and of the
+Fourier harmonic coefficient $v_2 (p_T)$ of azimuthally anisotropic particle
+distributions in high energy hadron collisions is often interpreted as evidence
+for the hydrodynamic flow of the matter produced. We investigate an alternative
+initial state interpretation of this pattern in high multiplicity proton-proton
+collisions at the LHC. The QCD Yang-Mills equations describing the dynamics of
+saturated gluons are solved numerically with initial conditions obtained from
+the Color Glass Condensate based IP-Glasma model. The gluons are subsequently
+fragmented into various hadron species employing the well established Lund
+string fragmentation algorithm of the PYTHIA event generator. We find that this
+ab initio initial state approach reproduces characteristic features of bulk
+spectra, in particular the particle mass dependence of $\left<p_T\right>$ and
+$v_2 (p_T)$.",1607.02496v2
+2016-07-11,Forward di-jet production in p+Pb collisions in the small-x improved TMD factorization framework,"We study the production of forward di-jets in proton-lead and proton-proton
+collisions at the Large Hadron Collider. Such configurations, with both jets
+produced in the forward direction, impose a dilute-dense asymmetry which allows
+to probe the gluon density of the lead or proton target at small longitudinal
+momentum fractions. Even though the jet momenta are always much bigger than the
+saturation scale of the target, $Q_s$, the transverse momentum imbalance of the
+di-jet system may be either also much larger than $Q_s$, or of the order $Q_s$,
+implying that the small-$x$ QCD dynamics involved is either linear or
+non-linear, respectively. The small-$x$ improved TMD factorization framework
+deals with both situation in the same formalism. In the latter case, which
+corresponds to nearly back-to-back jets, we find that saturation effects induce
+a significant suppression of the forward di-jet azimuthal correlations in
+proton-lead versus proton-proton collisions.",1607.03121v1
+2016-07-13,Comparison of Models of Fast Saturable Absorption in Passively Modelocked Lasers,"Fast saturable absorbers (FSAs) play a critical role in stabilizing many
+passively modelocked lasers. The most commonly used averaged model to study
+these lasers is the Haus modelocking equation (HME) that includes a third-order
+nonlinear FSA. However, it predicts a narrow region of stability that is
+inconsistent with experiments. To better replicate the laser physics, averaged
+laser models that include FSAs with higher-than-third-order nonlinearities have
+been introduced. Here, we compare three common FSA models to each other and to
+the HME using the recently-developed boundary tracking algorithms. The three
+FSA models are the cubic-quintic model, the sinusoidal model, and the algebraic
+model. We find that all three models predict the existence of a stable
+high-energy solution that is not present in the HME and have a much larger
+stable operating region. We also find that all three models predict
+qualitatively similar stability diagrams. We conclude that averaged laser
+models that include FSAs with higher-than-third-order nonlinearity should be
+used when studying the stability of passively modelocked lasers.",1607.03713v1
+2016-07-20,Nonlocal topological valley transport at large valley Hall angles,"Berry curvature hot spots in two-dimensional materials with broken inversion
+symmetry are responsible for the existence of transverse valley currents, which
+give rise to giant nonlocal dc voltages. Recent experiments in high-quality
+gapped graphene have highlighted a saturation of the nonlocal resistance as a
+function of the longitudinal charge resistivity $\rho_{{\rm c}, xx}$, when the
+system is driven deep into the insulating phase. The origin of this saturation
+is, to date, unclear. In this work we show that this behavior is fully
+compatible with bulk topological transport in the regime of large valley Hall
+angles (VHAs). We demonstrate that, for a fixed value of the valley diffusion
+length, the dependence of the nonlocal resistance on $\rho_{{\rm c}, xx}$
+weakens for increasing VHAs, transitioning from the standard $\rho^3_{{\rm c},
+xx}$ power-law to a result that is independent of $\rho_{{\rm c}, xx}$.",1607.05902v1
+2016-07-20,Characterization of qubit chains by Feynman probes,"We address the characterization of qubit chains and assess the performances
+of local measurements compared to those provided by Feynman probes, i.e.
+nonlocal measurements realized by coupling a single qubit regis- ter to the
+chain. We show that local measurements are suitable to estimate small values of
+the coupling and that a Bayesian strategy may be successfully exploited to
+achieve optimal precision. For larger values of the coupling Bayesian local
+strategies do not lead to a consistent estimate. In this regime, Feynman probes
+may be exploited to build a consistent Bayesian estimator that saturates the
+Cram\'er-Rao bound, thus providing an effective characterization of the chain.
+Finally, we show that ultimate bounds to precision, i.e. saturation of the
+quantum Cram\'er-Rao bound, may be achieved by a two-step scheme employing
+Feynman probes followed by local measurements.",1607.06124v2
+2016-07-28,Entanglement Entropy of Local Operators in Quantum Lifshitz Theory,"We study the growth of entanglement entropy(EE) of local operator excitation
+in the quantum Lifshitz model which has dynamic exponent z = 2. Specifically,
+we act a local vertex operator on the groundstate at a distance $l$ to the
+entanglement cut and calculate the EE as a function of time for the state's
+subsequent time evolution. We find that the excess EE compared with the
+groundstate is a monotonically increasing function which is vanishingly small
+before the onset at $t \sim l^2$ and eventually saturates to a constant
+proportional to the scaling dimension of the vertex operator. The
+quasi-particle picture can interpret the final saturation as the exhaustion of
+the quasi-particle pairs, while the diffusive nature of the time scale $t \sim
+l^2$ replaces the common causality constraint in CFT calculation. To further
+understand this property, we compute the excess EE of a small disk probe far
+from the excitation point and find chromatography pattern in EE generated by
+quasi-particles of different propagation speeds.",1607.08631v1
+2016-07-30,Environmental Instability and Degradation of Single- and Few-Layer WTe2 Nanosheets in Ambient Conditions,"Since the discovery of large, non-saturating magnetoresistance in bulk WTe2
+which allows microexfoliation, single- and few-layer WTe2 crystals have
+attracted increasing interests. However, as it mentioned in existing studies,
+WTe2 flakes appear to degrade in ambient conditions. Here we report
+experimental observations of saturating degradation in few-layer WTe2 through
+Raman spectroscopy characterization and careful monitoring of the degradation
+of single-, bi- and tri-layer (1L, 2L & 3L) WTe2 over long time. Raman peak
+intensity decreases during WTe2 degradation and 1L flakes degrade faster than
+2L and 3L flakes. The relatively faster degradation in 1L WTe2 could be
+attributed to low energy barrier of oxygen reaction with WTe2. We further
+investigate the degradation mechanisms of WTe2 using XPS and AES and find that
+oxidation of Te and W atoms is the main reason of WTe2 degradation. In
+addition, we observe oxidation occurs only in the depth of 0.5nm near the
+surface, and the oxidized WTe2 surface could help prevent inner layers from
+further degradation.",1608.00097v2
+2016-08-11,Modulation of sensory information processing by a neuroglobin in C. elegans,"Sensory receptor neurons match their dynamic range to ecologically relevant
+stimulus intensities. How this tuning is achieved is poorly understood in most
+receptors. We show that in the C. elegans URX O2 sensing neurons two putative
+molecular O2 sensors, a neuroglobin and O2-binding soluble guanylate cyclases,
+work antagonistically to sculpt a slowly sigmoidal O2 response curve tuned to
+approach saturation when O2 reaches 21%. glb-5 imposes this sigmoidal function
+by inhibiting O2-evoked Ca2+ responses in URX when O2 levels fall. Without
+GLB-5, the URX response curve approaches saturation at 15% O2. Behaviorally,
+GLB-5 signaling broadens the O2 preference of C. elegans while maintaining
+strong avoidance of 21% O2. Our computational aerotaxis model suggests that the
+relationship between GLB-5-modulated URX responses and reversal behavior is
+sufficient to broaden O2-preference. Thus, a neuroglobin can shift neural
+information coding leading to a change in perception and altered behavior.",1608.03477v2
+2016-08-26,Energy dependence of dissociative $\mathrm{J/}ψ$ photoproduction as a signature of gluon saturation at the LHC,"We have developed a model in which the quantum fluctuations of the proton
+structure are characterised by hot spots, whose number grows with decreasing
+Bjorken-$x$. Our model reproduces the $F_2(x,Q^2)$ data from HERA at the
+relevant scale, as well as the exclusive and dissociative $\mathrm{J/}\psi$
+photoproduction data from H1 and ALICE. Our model predicts that for
+$W_{\gamma\mathrm{p}} \approx 500$ GeV, the dissociative $\mathrm{J/}\psi$
+cross section reaches a maximum and then decreases steeply with energy, which
+is in qualitatively good agreement to a recent observation that the
+dissociative $\mathrm{J/}\psi$ background in the exclusive $\mathrm{J/}\psi$
+sample measured in photoproduction by ALICE decreases as energy increases. Our
+prediction provides a clear signature for gluon saturation at LHC energies.",1608.07559v2
+2016-08-27,Logic programming: laxness and saturation,"A propositional logic program $P$ may be identified with a $P_fP_f$-coalgebra
+on the set of atomic propositions in the program. The corresponding
+$C(P_fP_f)$-coalgebra, where $C(P_fP_f)$ is the cofree comonad on $P_fP_f$,
+describes derivations by resolution. That correspondence has been developed to
+model first-order programs in two ways, with lax semantics and saturated
+semantics, based on locally ordered categories and right Kan extensions
+respectively. We unify the two approaches, exhibiting them as complementary
+rather than competing, reflecting the theorem-proving and proof-search aspects
+of logic programming. While maintaining that unity, we further refine lax
+semantics to give finitary models of logic programs with existential variables,
+and to develop a precise semantic relationship between variables in logic
+programming and worlds in local state.",1608.07708v2
+2016-09-01,Rigidity of Free Boundary Surfaces in Compact 3-Manifolds with Strictly Convex Boundary,"In this paper we obtain an analogue of Toponogov theorem in dimension 3 for
+compact manifolds $M^3$ with nonnegative Ricci curvature and strictly convex
+boundary $\partial M$. Here we obtain a sharp upper bound for the length
+$L(\partial\Sigma)$ of the boundary $\partial\Sigma$ of a free boundary minimal
+surface $\Sigma^2$ in $M^3$ in terms of the genus of $\Sigma$ and the number of
+connected components of $\partial\Sigma$, assuming $\Sigma$ has index one.
+After, under a natural hypothesis on the geometry of $M$ along $\partial M$, we
+prove that if $L(\partial\Sigma)$ saturates the respective upper bound, then
+$M^3$ is isometric to the Euclidean 3-ball and $\Sigma^2$ is isometric to the
+Euclidean disk. In particular, we get a sharp upper bound for the area of
+$\Sigma$, when $M^3$ is a strictly convex body in $\mathbb R^3$, which is
+saturated only on the Euclidean 3-balls (by the Euclidean disks). We also
+consider similar results for stationary stable surfaces.",1609.00366v2
+2016-09-07,Role of acoustic phonons in frequency dependent thermal conductivity of graphene,"We study the effect of the electron-phonon interaction on the finite
+frequency dependent electronic thermal conductivity of two dimensional
+graphene. We calculate it for various acoustic phonons present in graphene and
+characterized by different dispersion relations using the memory function
+approach. It is found that the thermal conductivity $\kappa(T)$ in the zero
+frequency limit follows different power law for the longitudinal/transverse and
+the flexural acoustic phonons. For the longitudinal/transverse phonons,
+$\kappa(T) \sim T^{-1}$ at the low temperature and saturates at the high
+temperature. These signatures are qualitatively agree with the results
+predicted by the Boltzmann equation. Similarly, for the flexural phonons, we
+find that $\kappa(T)$ shows $T^{1/2}$ law at the low temperature and then
+saturates at the high temperature. In the finite frequency regime, we observe
+that the real part of the thermal conductivity, $\text{Re}[\kappa(\omega,T)]$
+follows $\omega^{-2}$ behavior at the low frequency and becomes frequency
+independent at the high frequency.",1609.01941v1
+2016-09-13,Nonlinear amplitude dynamics in flagellar beating,"The physical basis of flagellar and ciliary beating is a major problem in
+biology which is still far from completely understood. The fundamental
+cytoskeleton structure of cilia and flagella is the axoneme, a cylindrical
+array of microtubule doublets connected by passive crosslinkers and dynein
+motor proteins. The complex interplay of these elements leads to the generation
+of self-organized bending waves. Although many mathematical models have been
+proposed to understand this process, few attempts have been made to assess the
+role of dyneins on the nonlinear nature of the axoneme. Here, we investigate
+the nonlinear dynamics of flagella by considering an axonemal sliding control
+mechanism for dynein activity. This approach unveils the nonlinear selection of
+the oscillation amplitudes, which are typically either missed or prescribed in
+mathematical models. The explicit set of nonlinear equations are derived and
+solved numerically. Our analysis reveals the spatiotemporal dynamics of dynein
+populations and flagellum shape for different regimes of motor activity, medium
+viscosity and flagellum elasticity. Unstable modes saturate via the coupling of
+dynein kinetics and flagellum shape without the need of invoking a nonlinear
+axonemal response. Hence, our work reveals a novel mechanism for the saturation
+of unstable modes in axonemal beating.",1609.03837v2
+2016-09-16,CMOS-Memristor Dendrite Threshold Circuits,"Non-linear neuron models overcomes the limitations of linear binary models of
+neurons that have the inability to compute linearly non-separable functions
+such as XOR. While several biologically plausible models based on dendrite
+thresholds are reported in the previous studies, the hardware implementation of
+such non-linear neuron models remain as an open problem. In this paper, we
+propose a circuit design for implementing logical dendrite non-linearity
+response of dendrite spike and saturation types. The proposed dendrite cells
+are used to build XOR circuit and intensity detection circuit that consists of
+different combinations of dendrite cells with saturating and spiking responses.
+The dendrite cells are designed using a set of memristors, Zener diodes, and
+CMOS NOT gates. The circuits are designed, analyzed and verified on circuit
+boards.",1609.04921v1
+2016-09-25,Pro-aperiodic monoids via saturated models,"We apply Stone duality and model theory to study the structure theory of free
+pro-aperiodic monoids. Stone duality implies that elements of the free
+pro-aperiodic monoid may be viewed as elementary equivalence classes of
+pseudofinite words. Model theory provides us with saturated words in each such
+class, i.e., words in which all possible factorizations are realized. We give
+several applications of this new approach, including a solution to the word
+problem for $\omega$-terms that avoids using McCammond's normal forms, as well
+as new proofs and extensions of other structural results concerning free
+pro-aperiodic monoids.",1609.07736v2
+2016-09-29,Broadband frequency conversion via adiabatically tapered $χ^{(2)}$ waveguide in photonic integrated circuits,"We propose to use the integrated aluminum nitride waveguide with engineered
+width variation to achieve optical frequency conversion based on $\chi^{(2)}$
+nonlinear effect on a photonic chip. We show that in an adiabatically tapered
+waveguide, the frequency conversion has a much broader bandwidth and the
+efficiency within the bandwidth is almost constant, which is favorable for
+short pulses. We demonstrate both analytically and numerically an ""area law""
+for the frequency conversion, i.e. the product of bandwidth and efficiency is
+conserved as long as peak conversion efficiency does not saturate. The
+adiabatic structure shows higher saturation thresholds in pump power or
+interaction length, outperforming the conventional uniform waveguide design.
+With our approach, high-efficiency and wavefront-keeping conversion for short
+pulses is possible on a photonic chip, which will surely find applications for
+scalable on-chip information processing.",1609.09221v1
+2016-10-02,Alkali doping of graphene: the crucial role of high temperature annealing,"The doping efficiency of lithium deposited at cryogenic temperatures on
+epitaxial and CVD monolayer graphene has been investigated under ultra-high
+vacuum conditions. Change of charge carrier density was monitored by gate
+voltage shift of the Dirac point and by Hall measurements, in low and high
+doping regimes. It was found that pre-annealing the graphene greatly enhanced
+the maximum levels of doping that could be achieved: doping saturated at
+$\Delta n = 2\times 10^{13}$ e$^-$/cm$^2$ without annealing, independent of
+sample type or previous processing; after a 900 K anneal, the saturated doping
+rose one order of magnitude to $\Delta n = 2\times 10^{14}$ e$^-$/cm$^2$.",1610.00301v1
+2016-10-06,Correlations between critical parameters and bulk properties of nuclear matter,"The present work starts by providing a clear identification of correlations
+between critical parameters ($T_c$, $P_c$, $\rho_c$) and bulk quantities at
+zero temperature of relativistic mean-field models (RMF) presenting third and
+fourth order self-interactions in the scalar field $\sigma$. Motivated by the
+nonrelativistic version of this RMF model, we show that effective nucleon mass
+($M^*$) and incompressibility ($K_o$), at the saturation density, are
+correlated with $T_c$, $P_c$, and $\rho_c$, as well as, binding energy and
+saturation density itself. We verify agreement of results with previous
+theoretical ones regarding different hadronic models. Concerning recent
+experimental data of the symmetric nuclear matter critical parameters, our
+study allows a prediction of $T_c$, $P_c$ and $\rho_c$ compatible with such
+values, by combining them, through the correlations found, with previous
+constraints related to $M^*$ and $K_o$. An improved RMF parametrization, that
+better agrees with experimental values for $T_c$, is also indicated.",1610.01974v1
+2016-10-14,Modelling large-deforming fluid-saturated porous media using an Eulerian incremental formulation,"The paper deals with modelling fluid saturated porous media subject to large
+deformation. An Eulerian incremental formulation is derived using the problem
+imposed in the spatial configuration in terms of the equilibrium equation and
+the mass conservation. Perturbation of the hyperelastic porous medium is
+described by the Biot model which involves poroelastic coefficients and the
+permeability governing the Darcy flow. Using the material derivative with
+respect to a convection velocity field we obtain the rate formulation which
+allows for linearization of the residuum function. For a given time
+discretization with backward finite difference approximation of the time
+derivatives, two incremental problems are obtained which constitute the
+predictor and corrector steps of the implicit time-integration scheme.
+Conforming mixed finite element approximation in space is used. Validation of
+the numerical model implemented in the SfePy code is reported for an isotropic
+medium with a hyperelastic solid phase. The proposed linearization scheme is
+motivated by the two-scale homogenization which will provide the local material
+poroelastic coefficients involved in the incremental formulation.",1610.05103v2
+2016-10-17,Drell-Yan production at forward rapidities: a hybrid factorization approach,"We discuss the Drell-Yan production of dileptons at high energies in the
+forward rapidity region of proton-proton collisions in a hybrid high-energy
+approach. This approach uses unintegrated gluon distributions in one proton and
+collinear quark/antiquark distributions in the second proton.
+  We compute various distributions for the case of low-mass dilepton production
+and compare to the LHCb and ATLAS experimental data on dilepton mass
+distributions. In distinction to dipole approaches, we include four Drell-Yan
+structure functions as well as cuts at the level of lepton kinematics. The
+impact of the interference structure functions is rather small for typical
+experimental cuts. We find that both side contributions ($g q/\bar q$ and
+$q/\bar q g$) have to be included even for the LHCb rapidity coverage which is
+in contradiction with what is usually done in the dipole approach. We present
+results for different unintegrated gluon distributions from the literature.
+Some of them include saturation effects, but we see no clear hints of
+saturation even at small $M_{ll}$.",1610.05123v1
+2016-10-21,Scale-Dependent Pedotransfer Functions Reliability for Estimating Saturated Hydraulic Conductivity,"Saturated hydraulic conductivity Ksat is a fundamental characteristic in
+modeling flow and contaminant transport in soils and sediments. Therefore, many
+models have been developed to estimate Ksat from easily measureable parameters,
+such as textural properties, bulk density, etc. However, Ksat is not only
+affected by textural and structural characteristics, but also by scale e.g.,
+internal diameter and height. Using the UNSODA database and the contrast
+pattern aided regression (CPXR) method, we recently developed scale-dependent
+pedotransfer functions to estimate Ksat from textural data, bulk density, and
+sample dimensions. The main objectives of this study were evaluating the
+proposed pedotransfer functions using a larger database, and comparing them
+with seven other models. For this purpose, we selected more than nineteen
+thousands soil samples from all around the United States. Results showed that
+the scale-dependent pedotransfer functions estimated Ksat more accurately than
+seven other models frequently used in the literature.",1610.06958v1
+2016-10-28,Anharmonic particles: suppressing van der Waals forces by an external field,"We study the classical thermal component of Casimir, or van der Waals, forces
+between point particles with highly anharmonic dipole Hamiltonians when they
+are subjected to an external electric field. Using a model for which the
+individual dipole moments saturate in a strong field (a model that mimics the
+charges in a neutral, perfectly conducting sphere), we find that the resulting
+Casimir force depends strongly on the strength of the field, as demonstrated by
+analytical results. For a certain angle between external field and center to
+center axis, the fluctuation force can be tuned and suppressed to arbitrarily
+small values. We compare the forces between these anharmonic particles to those
+between harmonic ones, and also provide a simple formula for asymptotically
+large external fields, which we expect to be generally valid for the case of
+saturating dipole moments.",1610.09192v1
+2016-10-31,Homogeneous Atomic Fermi Gases,"We report on the creation of homogeneous Fermi gases of ultracold atoms in a
+uniform potential. In the momentum distribution of a spin-polarized gas, we
+observe the emergence of the Fermi surface and the saturated occupation of one
+particle per momentum state. This directly confirms Pauli blocking in momentum
+space. For the spin-balanced unitary Fermi gas, we observe spatially uniform
+pair condensates. For thermodynamic measurements, we introduce a hybrid
+potential that is harmonic in one dimension and uniform in the other two. The
+spatially resolved compressibility reveals the superfluid transition in a
+spin-balanced Fermi gas, saturation in a fully polarized Fermi gas, and strong
+attraction in the polaronic regime of a partially polarized Fermi gas.",1610.10100v1
+2016-11-01,Phenomenology of hard diffraction at high energies,"We present some of the topics covered in two lectures under the same title
+that were given at the ""Summer School on High Energy Physics at the LHC: New
+trends in HEP"" in Natal, Brazil. In this contribution we give a brief review on
+the application of perturbative QCD to the hard diffractive processes. Some
+examples of phenomenology for the diffractive production of $W/Z$, heavy
+$Q\bar{Q}$ and quarkonium in hadron-hadron reactions are presented. It is also
+discussed the exclusive diffractive processes in $ep$ interactions. They are in
+general driven by the gluon content of proton which is strongly subject to
+parton saturation effects in the very high energy limit. These saturation
+effects are well described within the color dipole formalism. We present some
+examples of corresponding phenomenology as the elastic vector meson production
+and the DVCS relying on the color dipole approach.",1611.00378v2
+2016-12-09,Analyzing the Synergy between Broadcast Polling and Piggybacking in WiMAX Networks,"In this work we present a model for analyzing the combined use of broadcast
+polling and piggybacking in Worldwide Interoperability for Microwave Access
+(WiMAX) networks. For an accurate analysis of piggybacking, the model focuses
+on the realistic case of limited up-link bandwidth and non-trivial queueing
+capability at the subscriber stations. We first model the activity of a
+subscriber station using a Markov chain and its queue as an M/G/1 system with
+vacations in order to facilitate the analysis of the piggyback mechanism. We
+then derive a set of fixed point equations that describe not only the
+contention process at the network level but also bandwidth allocation to
+contending and piggybacked requests. Our model uses a minimal set of
+assumptions and is generic in the sense that it is customizable through a set
+of parameters. It can also reproduce the system performance in both saturated
+and non-saturated conditions. After validating our analysis through extensive
+simulations, we shed light on the aspects of the synergy between broadcast
+polling and piggybacking and unveil the pros and cons of using the latter.",1612.03042v1
+2016-12-23,Note on the saturation of the norm inequalities between diamond and nuclear norm,"The diamond norm plays an important role in quantum information and operator
+theory. Recently, it has also been proposed as a regularizer for low-rank
+matrix recovery. The norm constants that bound the diamond norm in terms of the
+nuclear norm (also known as trace norm) are explicitly known. This note
+provides a simple characterization of all operators saturating the upper and
+the lower bound.",1612.07931v3
+2016-12-29,Effects of non-physiological blood pressure artefacts on measures of cerebral autoregulation,"Cerebral autoregulation refers to regulation mechanisms that aim to maintain
+cerebral blood flow approximately constant. It is often assessed by
+autoregulation index (ARI), which uses arterial blood pressure and cerebral
+blood flow velocity time series to produce a ten-scale index of autoregulation
+performance (0 denoting the absence of and 9 the strongest autoregulation).
+Unfortunately, data are rarely free from various artefacts. Here, we consider
+four of the most common non-physiological blood pressure artefacts (saturation,
+square wave, reduced pulse pressure and impulse) and study their effects on ARI
+for a range of different artefact sizes. We show that a sufficiently large
+saturation and square wave always result in ARI reaching the maximum value of
+9. The pulse pressure reduction and impulse artefact lead to a more diverse
+behaviour. Finally, we characterised the critical size of artefacts, defined as
+the minimum artefact size that, on average, leads to a 10\% deviation of ARI",1612.09486v1
+2017-01-04,Parton saturation scaling function for exclusive production of vector mesons and Deeply Virtual Compton Scattering,"We provide a universal expression of cross sections for the exclusive vector
+meson production and Deeply Virtual Compton Scattering (DVCS) in photon-proton
+and photon-nucleus interactions based on the geometric scaling phenomenon. The
+theoretical parameterization based on the scaling property depends only on the
+single variable $\tau_A = Q^2/Q_{\mathrm{sat}}^2$, where the saturation scale,
+$Q_{\mathrm{sat}}$, drives the energy dependence and the corresponding nuclear
+effects. This phenomenological result describes all available data from
+DESY-HERA for $\rho,\,\phi,\,J/\psi$ production and DVCS measurements. A
+discussion on the size of nuclear shadowing corrections on photon-nucleus
+interaction is also done.",1701.01141v3
+2017-01-25,NS saturated and $Δ_1$-definable,"We show that under the assumption of the existence of the canonical inner
+model with one Woodin cardinal $M_1$, there is a model of $\ZFC$ in which $\NS$
+is $\aleph_2$-saturated and $\Delta_1$-definable with $\omega_1$ as a parameter
+which answers a question of Sy-David Friedman and Liuzhen Wu. We also show that
+starting from an arbitrary universe with a Woodin cardinal, there is a model
+with $\NS$ saturated and $\Delta_1$-definable with a ladder system $\vec{C}$
+and a full Suslin tree $T$ as parameters. Both results rely on a new coding
+technique whose presentation is the main goal of this article.",1701.07230v5
+2017-01-30,Probing Nuclear PDF and Gluon Saturation At The LHC with Forward Direct Photons,"In relativistic nuclear collisions some of the important aspects to be
+addressed are the effects of the nuclear PDF and the gluon saturation. In the
+LHC the best way to address these questions is by means of pA collisions and in
+particular through the measurement of direct photon production in the forward
+direction. In order to achieve this measurement a new forward calorimeter
+(FoCal) is proposed as an upgrade to the ALICE experiment. The proposed
+detector will cover the range 3.5 < $\eta$ < 5, probing the gluon distributions
+at x$\sim$10$^{-5}$ and Q$\sim p_{\rm T}$ > 4 GeV. We will discuss performance
+studies and demonstrate that extremely high-granularity calorimetry is required
+for such measurement. We will also present a few results from R\&D for this
+project.",1701.08677v1
+2017-01-31,NIMROD Modeling of Quiescent H-mode: Reconstruction Considerations and Saturation Mechanism,"The extended-MHD NIMROD code [C.R. Sovinec and J.R. King, J. Comput. Phys.
+229, 5803 (2010)] models broadband-MHD activity from a reconstruction of a
+quiescent H-mode shot on the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614
+(2002)]. Computations with the reconstructed toroidal and poloidal ion flows
+exhibit low-n perturbations (n=1-5) that grow and saturate into a
+turbulent-like MHD state. The workflow used to project the reconstructed state
+onto the NIMROD basis functions re-solves the Grad-Shafranov equation and
+extrapolates profiles to include scrape-off-layer currents. Evaluation of the
+transport from the turbulent-like MHD state leads to a relaxation of the
+density and temperature profiles.",1702.00050v1
+2017-02-07,Calibrating High Intensity Absorption Imaging of Ultracold Atoms,"Absorption imaging of ultracold atoms is the foundation for quantitative
+extraction of information from experiments with ultracold atoms. Due to the
+limited exposure time available in these systems, the signal-to-noise ratio is
+largest for high intensity absorption imaging where the intensity of the
+imaging light is on the order of the saturation intensity. In this case, the
+absolute value of the intensity of the imaging light enters as an additional
+parameter making it more sensitive to systematic errors. Here, we present a
+novel and robust technique to determine the imaging intensity in units of the
+effective saturation intensity to better than 5%. We do this by measuring the
+momentum transferred to the atoms by the imaging light while varying its
+intensity. We further utilize the method to quantify the purity of the
+polarization of the imaging light and to determine the correct imaging
+detuning.",1702.01943v2
+2017-02-09,Equilibrium configurations of large nanostructures using the embedded saturated-fragments stochastic density functional theory,"An \emph{ab initio} Langevin dynamics approach is developed based on
+stochastic density functional theory (sDFT) within a new \emph{embedded
+saturated } \emph{fragment }formalism, applicable to covalently bonded systems.
+The forces on the nuclei generated by sDFT contain a random component natural
+to Langevin dynamics and its standard deviation is used to estimate the
+friction term on each atom by satisfying the fluctuation\textendash dissipation
+relation. The overall approach scales linearly with system size even if the
+density matrix is not local and is thus applicable to ordered as well as
+disordered extended systems. We implement the approach for a series of silicon
+nanocrystals (NCs) of varying size with a diameter of up to $3$nm corresponding
+to $N_{e}=3000$ electrons and generate a set of configurations that are
+distributed canonically at a fixed temperature, ranging from cryogenic to room
+temperature. We also analyze the structure properties of the NCs and discuss
+the reconstruction of the surface geometry.",1702.02714v2
+2017-01-30,Characterization of gas diffusion electrodes for metal-air batteries,"Gas diffusion electrodes are commonly used in high energy density metal-air
+batteries for the supply of oxygen. Hydrophobic binder materials ensure the
+coexistence of gas and liquid phase in the pore network. The phase distribution
+has a strong influence on transport processes and electrochemical reactions. In
+this article we present 2D and 3D Rothman-Keller type multiphase
+Lattice-Boltzmann models which take into account the heterogeneous wetting
+behavior of gas diffusion electrodes. The simulations are performed on FIB-SEM
+3D reconstructions of an Ag model electrode for predefined saturation of the
+pore space with the liquid phase. The resulting pressure-saturation
+characteristics and transport correlations are important input parameters for
+modeling approaches on the continuum scale and allow for an efficient
+development of improved gas diffusion electrodes.",1702.04670v1
+2017-02-16,A comparative study of fluid-particle coupling methods for fully resolved lattice Boltzmann simulations,"The direct numerical simulation of particulate systems offers a unique
+approach to study the dynamics of fluid-solid suspensions by fully resolving
+the submerged particles and without introducing empirical models. For the
+lattice Boltzmann method, different variants exist to incorporate the
+fluid-particle interaction into the simulation. This paper provides a detailed
+and systematic comparison of two different methods, namely the momentum
+exchange method and the partially saturated cells method by Noble and
+Torczynski. Three subvariants of each method are used in the benchmark scenario
+of a single heavy sphere settling in ambient fluid to study their
+characteristics and accuracy for particle Reynolds numbers from 185 up to 365.
+The sphere must be resolved with at least 24 computational cells per diameter
+to achieve velocity errors below 5%. The momentum exchange method is found to
+be more accurate in predicting the streamwise velocity component whereas the
+partially saturated cells method is more accurate in the spanwise components.
+The study reveals that the resolution should be chosen with respect to the
+coupling dynamics, and not only based on the flow properties, to avoid large
+errors in the fluid-particle interaction.",1702.04910v1
+2017-03-02,Rigidity of volume-minimizing hypersurfaces in Riemannian 5-manifolds,"In this paper we generalize the main result of [4] for manifolds that are not
+necessarily Einstein. In fact, we obtain an upper bound for the volume of a
+locally volume-minimizing closed hypersurface $\Sigma$ of a Riemannian
+5-manifold $M$ with scalar curvature bounded from below by a positive constant
+in terms of the total traceless Ricci curvature of $\Sigma$. Furthermore, if
+$\Sigma$ saturates the respective upper bound and $M$ has nonnegative Ricci
+curvature, then $\Sigma$ is isometric to $\mathbb{S}^4$ up to scaling and $M$
+splits in a neighborhood of $\Sigma$. Also, we obtain a rigidity result for the
+Riemannian cover of $M$ when $\Sigma$ minimizes the volume in its homotopy
+class and saturates the upper bound.",1703.00930v2
+2017-03-13,C-SHORe: Higher-Order Verification via Collapsible Pushdown System Saturation,"Higher-order recursion schemes (HORS) have received much attention as a
+useful abstraction of higher-order functional programs with a number of new
+verification techniques employing HORS model-checking as their centrepiece. We
+give an account of the C-SHORe tool, which contributed to the ongoing quest for
+a truly scalable model-checker for HORS by offering a different, automata
+theoretic perspective. C-SHORe implements the first practical model-checking
+algorithm that acts on a generalisation of pushdown automata equi-expressive
+with HORS called collapsible pushdown systems (CPDS). At its core is a
+backwards saturation algorithm for CPDS. Additionally, it is able to use
+information gathered from an approximate forward reachability analysis to guide
+its backward search. Moreover, it uses an algorithm that prunes the CPDS prior
+to model-checking and a method for extracting counter-examples in negative
+instances. We provide an up-to-date comparison of C-SHORe with the
+state-of-the-art verification tools for HORS. The tool and additional material
+are available from http://cshore.cs.rhul.ac.uk.",1703.04429v2
+2017-03-16,"Optical Thickness, Spin Temperature, and Correction Factor for Density of the Galactic HI Gas","A method to determine the spin temperature of the local (Vlsr=0 km/s) HI gas
+using saturated brightness temperature of the 21-cm line in the radial-velocity
+degenerate regions (VDR) is presented. The spin temperatures is determined to
+be Ts= 146.2 +/- 16.1 K by measuring saturated brightness in the VDR toward the
+Galactic Center, 146.8 +/- 10.7 K by chi^2 fitting of expected brightness
+distribution to observation around the VDR, and 144.4 +/- 6.8 K toward the
+local arm. Assuming Ts=146 K, a correction factor Gamma for the HI density,
+defined by the ratio of the true HI density for finite optical thickness to
+that calculated by assuming optically thin HI, was obtained to be Gamma~1.2
+(optical depth tau~0.3) in the local HI gas, ~1.8 (~1.3) toward the arm and
+anti-center, and as high as ~3.6 (~2.7) in the Galactic Center direction. It is
+suggested that the HI density and mass in the local arm could be ~2 times, and
+that in the inner Galaxy ~3.6 times, greater than the currently estimated
+values.",1703.05565v1
+2017-03-21,Reconstructing the topology of the elementary self-embedding monoids of countable saturated structures,"Every transformation monoid comes equipped with a canonical topology-the
+topology of pointwise convergence. For some structures, the topology of the
+endomorphism monoid can be reconstructed from its underlying abstract monoid.
+This phenomenon is called automatic homeomorphicity.
+  In this paper we show that whenever the automorphism group of a countable
+saturated structure has automatic homeomorphicity and a trivial center, then
+the monoid of elementary self-embeddings has automatic homeomorphicity, too.
+  As a second result we strengthen a result by Lascar by showing that whenever
+$\mathbf{A}$ is a countable $\aleph_0$-categorical $G$-finite structure whose
+automorphism group has a trivial center and if $\mathbf{B}$ is any other
+countable structure, then every isomorphism between the monoids of elementary
+self-embeddings is a homeomorphism.",1703.07429v1
+2017-04-02,J/$ψ$ production as a function of charged-particle pseudorapidity density in p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV,"We report measurements of the inclusive J/$\psi$ yield and average transverse
+momentum as a function of charged-particle pseudorapidity density ${\rm
+d}N_{\rm ch}/{\rm d}\eta$ in p-Pb collisions at $\sqrt{s_{\rm NN}}= 5.02$ TeV
+with ALICE at the LHC. The observables are normalised to their corresponding
+averages in non-single diffractive events. An increase of the normalised
+J/$\psi$ yield with normalised ${\rm d}N_{\rm ch}/{\rm d}\eta$, measured at
+mid-rapidity, is observed at mid-rapidity and backward rapidity. At forward
+rapidity, a saturation of the relative yield is observed for high
+charged-particle multiplicities. The normalised average transverse momentum at
+forward and backward rapidities increases with multiplicity at low
+multiplicities and saturates beyond moderate multiplicities. In addition, the
+forward-to-backward nuclear modification factor ratio is also reported, showing
+an increasing suppression of J/$\psi$ production at forward rapidity with
+respect to backward rapidity for increasing charged-particle multiplicity.",1704.00274v2
+2017-04-10,A Representation of Weyl-Heisenberg Lie Algebra in the Quaternionic Setting,"Using a left multiplication defined on a right quaternionic Hilbert space,
+linear self-adjoint momentum operators on a right quaternionic Hilbert space
+are defined in complete analogy with their complex counterpart. With the aid of
+the so-obtained position and momentum operators, we study the Heisenberg
+uncertainty principle on the whole set of quaternions and on a quaternionic
+slice, namely on a copy of the complex plane inside the quaternions. For the
+quaternionic harmonic oscillator, the uncertainty relation is shown to saturate
+on a neighborhood of the origin in the case we consider the whole set of
+quaternions, while it is saturated on the whole slice in the case we take the
+slice-wise approach. In analogy with the complex Weyl-Heisenberg Lie algebra,
+Lie algebraic structures are developed for the quaternionic case. Finally, we
+introduce a quaternionic displacement operator which is square integrable,
+irreducible and unitary, and we study its properties.",1704.02946v2
+2017-04-13,Poincaré series of Lie lattices and representation zeta functions of arithmetic groups,"We compute explicit formulae for Dirichlet generating functions enumerating
+finite-dimensional irreducible complex representations of potent and saturable
+principal congruence subgroups of $\mathrm{SL}_4^m(\mathfrak{o})$
+($m\in\mathbb{N}$) for $\mathfrak{o}$ a compact DVR of characteristic $0$ and
+odd residue field characteristic. In doing so we develop a novel method for
+computing Poincar\'e series associated with commutator matrices of
+$\mathfrak{o}$-Lie lattices with finite abelianization and whose rank-loci
+enjoy an additional smoothness property. We give explicit formulae for the
+abscissa of convergence of the representation zeta functions of potent and
+saturable FAb $p$-adic analytic groups whose associated Lie lattices satisfy
+the hypotheses of the aforementioned method. As a by-product of our
+computations we find that not all $4\times 4$ traceless matrices over a finite
+quotient of $\mathfrak{o}$ admit shadow-preserving lifts, thus disproving that
+smooth loci of constant centralizer dimension in $\mathfrak{sl}_4(\mathbb{C})$
+ensure presence of shadow-preserving lifts for almost all primes as suggested
+in a previous paper by Avni, Klopsch, Onn and Voll.",1704.04165v3
+2017-04-16,Superradiant Instability and Backreaction of Massive Vector Fields around Kerr Black Holes,"We study the growth and saturation of the superradiant instability of a
+complex, massive vector (Proca) field as it extracts energy and angular
+momentum from a spinning black hole, using numerical solutions of the full
+Einstein-Proca equations. We concentrate on a rapidly spinning black hole
+($a=0.99$) and the dominant $m=1$ azimuthal mode of the Proca field, with real
+and imaginary components of the field chosen to yield an axisymmetric
+stress-energy tensor and, hence, spacetime. We find that in excess of $9\%$ of
+the black hole's mass can be transferred into the field. In all cases studied,
+the superradiant instability smoothly saturates when the black hole's horizon
+frequency decreases to match the frequency of the Proca cloud that
+spontaneously forms around the black hole.",1704.04791v2
+2017-04-21,Imprint of Nucleon Radius on the Slowly Rotating Neutron Star Properties,"We have studied the effect of free space nucleon radius on the nuclear matter
+and slowly rotating neutron star properties within a relativistic mean field
+model with the inclusion of omega-rho mixing nonlinear term. We use the same
+density dependent radius as in our previous work. However, in the present work
+we utilize the parameter sets with more proper symmetric nuclear matter (SNM)
+predictions for a number of different nucleon radii. To this end, the isoscalar
+parameters in each parameter set and the cutoff parameter $\beta$ are adjusted
+by fitting the corresponding SNM properties at sub-saturation density to the
+prediction of IUFSU parameter set. We have obtained that the assumption of
+composite nucleons with free space radius $r \le 0.83$ fm is still compatible
+with the currently acceptable nuclear matter (NM) properties beyond the
+saturation density. We have also found that the effect of free space nucleon
+radius could be imprinted in the radius, moment of inertia, and crust
+properties of the slowly rotating neutron star.",1704.06545v1
+2017-04-21,Trapping in bottlenecks: interplay between microscopic dynamics and large scale effects,"We investigate the appearance of trapping states in pedestrian flows through
+bottlenecks as a result of the interplay between the geometry of the system and
+the microscopic stochastic dynamics. We model the flow trough a bottleneck via
+a Zero Range Process on a one dimensional periodic lattice. Particle are
+removed from the lattice sites with rates proportional to the local occupation
+numbers. The bottleneck is modelled by a particular site of the lattice where
+the updating rate saturates to a constant value as soon as the local occupation
+number exceeds a fixed threshold. We show that, for any finite value of such
+threshold, the stationary particle current saturates to the limiting bottleneck
+rate when the total particle density in the system exceeds the bottleneck rate
+itself.",1704.06592v1
+2017-04-25,"Universality of Confluent, Self-Loop Deterministic Partially Ordered NFAs is Hard","An automaton is partially ordered if the only cycles in its transition
+diagram are self-loops. The expressivity of partially ordered NFAs (poNFAs) can
+be characterized by the Straubing-Th\'erien hierarchy. Level 3/2 is recognized
+by poNFAs, level 1 by confluent, self-loop deterministic poNFAs as well as by
+confluent poDFAs, and level 1/2 by saturated poNFAs. We study the universality
+problem for confluent, self-loop deterministic poNFAs. It asks whether an
+automaton accepts all words over its alphabet. Universality for both NFAs and
+poNFAs is a PSpace-complete problem. For confluent, self-loop deterministic
+poNFAs, the complexity drops to coNP-complete if the alphabet is fixed but is
+open if the alphabet may grow. We solve this problem by showing that it is
+PSpace-complete if the alphabet may grow polynomially. Consequently, our result
+provides a lower-bound complexity for some other problems, including inclusion,
+equivalence, and $k$-piecewise testability. Since universality for saturated
+poNFAs is easy, confluent, self-loop deterministic poNFAs are the simplest and
+natural kind of NFAs characterizing a well-known class of languages, for which
+deciding universality is as difficult as for general NFAs.",1704.07860v1
+2017-04-28,Delayed feedback control of self-mobile cavity solitons in a wide-aperture laser with a saturable absorber,"We investigate the spatiotemporal dynamics of cavity solitons in a broad area
+vertical-cavity surface-emitting laser with saturable absorption subjected to
+time-delayed optical feedback. Using a combination of analytical, numerical and
+path continuation methods we analyze the bifurcation structure of stationary
+and moving cavity solitons and identify two different types of traveling
+localized solutions, corresponding to slow and fast motion. We show that the
+delay impacts both stationary and moving solutions either causing drifting and
+wiggling dynamics of initially stationary cavity solitons or leading to
+stabilization of intrinsically moving solutions. Finally, we demonstrate that
+the fast cavity solitons can be associated with a lateral mode-locking regime
+in a broad-area laser with a single longitudinal mode.",1704.08869v1
+2017-05-05,Bifurcation structure of cavity soliton dynamics in a VCSEL with saturable absorber and time-delayed feedback,"We consider a wide-aperture surface-emitting laser with a saturable absorber
+section subjected to time-delayed feedback. We adopt the mean-field approach
+assuming a single longitudinal mode operation of the solitary VCSEL. We
+investigate cavity soliton dynamics under the effect of time- delayed feedback
+in a self-imaging configuration where diffraction in the external cavity is
+negligible. Using bifurcation analysis, direct numerical simulations and
+numerical path continuation methods, we identify the possible bifurcations and
+map them in a plane of feedback parameters. We show that for both the
+homogeneous and localized stationary lasing solutions in one spatial dimension
+the time-delayed feedback induces complex spatiotemporal dynamics, in
+particular a period doubling route to chaos, quasiperiodic oscillations and
+multistability of the stationary solutions.",1705.02250v1
+2017-05-09,Mechanisms of near-surface structural evolution in nanocrystalline materials during sliding contact,"The wear-driven structural evolution of nanocrystalline Cu was simulated with
+molecular dynamics under constant normal loads, followed by a quantitative
+analysis. While the microstructure far away from the sliding contact remains
+unchanged, grain growth accompanied by partial dislocations and twin formation
+was observed near the contact surface, with more rapid coarsening promoted by
+higher applied normal loads. The structural evolution continues with increasing
+number of sliding cycles and eventually saturates to a stable distinct layer of
+coarsened grains, separated from the finer matrix by a steep gradient in grain
+size. The coarsening process is balanced by the rate of material removal when
+the normal load is high enough. The observed structural evolution leads to an
+increase in hardness and decrease in friction coefficient, which also saturate
+after a number of sliding cycles. This work provides important mechanistic
+understanding of nanocrystalline wear, while also introducing a methodology for
+atomistic simulations of cyclic wear damage under constant applied normal
+loads.",1705.03132v2
+2017-05-10,Optimal measurements for simultaneous quantum estimation of multiple phases,"A quantum theory of multiphase estimation is crucial for quantum-enhanced
+sensing and imaging and may link quantum metrology to more complex quantum
+computation and communication protocols. In this letter we tackle one of the
+key difficulties of multiphase estimation: obtaining a measurement which
+saturates the fundamental sensitivity bounds. We derive necessary and
+sufficient conditions for projective measurements acting on pure states to
+saturate the maximal theoretical bound on precision given by the quantum Fisher
+information matrix. We apply our theory to the specific example of
+interferometric phase estimation using photon number measurements, a convenient
+choice in the laboratory. Our results thus introduce concepts and methods
+relevant to the future theoretical and experimental development of
+multiparameter estimation.",1705.03687v1
+2017-05-17,"Parallel-in-Space-and-Time Simulation of the Three-Dimensional, Unsteady Navier-Stokes Equations for Incompressible Flow","In this paper we combine the Parareal parallel-in-time method together with
+spatial parallelization and investigate this space-time parallel scheme by
+means of solving the three-dimensional incompressible Navier-Stokes equations.
+Parallelization of time stepping provides a new direction of parallelization
+and allows to employ additional cores to further speed up simulations after
+spatial parallelization has saturated. We report on numerical experiments
+performed on a Cray XE6, simulating a driven cavity flow with and without
+obstacles. Distributed memory parallelization is used in both space and time,
+featuring up to 2,048 cores in total. It is confirmed that the
+space-time-parallel method can provide speedup beyond the saturation of the
+spatial parallelization.",1705.06149v1
+2017-05-18,Generation of forerunner electron beam during interaction of ion beam pulse with plasma,"The long-time evolution of the two-stream instability of a cold ion beam
+pulse propagating though the background plasma is investigated using a
+large-scale one-dimensional electrostatic kinetic simulation. The three stages
+of the instability are identified and investigated in detail. After the initial
+linear growth and saturation by the electron trapping, a portion of the
+initially trapped electrons becomes detrapped and moves ahead of the ion beam
+pulse forming a {forerunner} electron beam, which causes a secondary two-stream
+instability that preheats the upstream plasma electrons. Consequently, the
+self-consistent nonlinear-driven turbulent state is set up at the head of the
+ion beam pulse with the saturated plasma wave sustained by the influx of the
+cold electrons from the upstream of the beam that lasts until the final stage
+when the beam ions become trapped by the plasma wave. The beam ion trapping
+leads to the nonlinear heating of the beam ions that eventually extinguishes
+the instability.",1705.06806v1
+2017-05-22,Accretion Dynamics on Wet Granular Materials,"Wet granular aggregates are common precursors of construction materials,
+food, and health care products. The physical mechanisms involved in the mixing
+of dry grains with a wet substrate are not well understood and difficult to
+control. Here, we study experimentally the accretion of dry grains on a wet
+granular substrate by measuring the growth dynamics of the wet aggregate. We
+show that this aggregate is fully saturated and its cohesion is ensured by the
+capillary depression at the air-liquid interface. The growth dynamics is
+controlled by the liquid fraction at the surface of the aggregate and exhibits
+two regimes. In the viscous regime, the growth dynamics is limited by the
+capillary-driven flow of liquid through the granular packing to the surface of
+the aggregate. In the capture regime, the capture probability depends on the
+availability of the liquid at the saturated interface, which is controlled by
+the hydrostatic depression in the material. We propose a model that
+rationalizes our observations and captures both dynamics based on the evolution
+of the capture probability with the hydrostatic depression.",1705.07783v1
+2017-05-23,On Controllable Abundance Of Saturated-input Linear Discrete Systems,"Several theorems on the volume computing of the polyhedron spanned by a
+n-dimensional vector set with the finite-interval parameters are presented and
+proved firstly, and then are used in the analysis of the controllable regions
+of the linear discrete time-invariant systems with saturated inputs. A new
+concept and continuous measure on the control ability, control efficiency of
+the input variables, and the diversity of the control laws, named as the
+controllable abundance, is proposed based on the volume computing of the
+regions and is applied to the actuator placing and configuring problems, the
+optimizing problems of dynamics and kinematics of the controlled plants, etc..
+The numerical experiments show the effectiveness of the new concept and methods
+for investigating and optimizing the control ability and efficiency.",1705.08064v2
+2017-05-30,Can hail and rain nucleate cloud droplets?,"We present results from moist convection in a mixture of pressurized sulfur
+hexa-flouride (liquid and vapor) and helium (gas) to model the wet and dry
+components of the earth's atmosphere. To allow for homogeneous nucleation, we
+operate the experiment close to critical conditions. We report on the
+nucleation of microdroplets in the wake of large cold liquid drops falling
+through the supersaturated atmosphere and show that the homogeneous nucleation
+is caused by isobaric cooling of the saturated sulfur hexaflouride vapor. Our
+results carry over to atmospheric clouds: falling hail and cold rain drops may
+enhance the heterogeneous nucleation of microdroplets in their wake under
+supersaturated atmospheric conditions. We also observed that under appropriate
+conditions settling microdroplets form a rather stable horizontal cloud layer,
+which separates regions of super and sub critical saturation.",1705.10501v1
+2017-06-02,Dynamics and instabilities of Lasing Light Bullets in Passively Mode-Locked Semiconductor Lasers,"Recently, the existence of robust three-dimensional light bullets (LBs) was
+predicted theoretically in the output of a laser coupled to a distant saturable
+absorber. In this manuscript, we analyze the stability and the range of
+existence of these dissipative localized structures and provide guidelines and
+realistic parameter sets for their experimental observation. In order to reduce
+the complexity of the analysis, we first approximate the three-dimensional
+problem by a reduced equation governing the dynamics of the transverse profile.
+This effective theory provides an intuitive picture of the LB formation
+mechanism. Moreover, it allows us to perform a detailed multi-parameter
+bifurcation study and to identify the different mechanisms of instability. It
+is found that the LBs experience dominantly either homogeneous oscillation or
+symmetry breaking transversal waves radiation. In addition, our analysis
+reveals several non-intuitive scaling behaviors as functions of the linewidth
+enhancement factors and the saturation parameters. Our results are confirmed by
+direct numerical simulations of the full system.",1706.00630v1
+2017-06-03,Reduced work function of graphene by metal adatoms,"In this paper, the work function of graphene doped by different metal adatoms
+and at different concentrations is investigated. Density functional theory is
+used to maximize the reduction of the work function. In general, the work
+function drops significantly before reaching saturation. For example in the
+case of Cs doping, the work function saturates at 2.05 eV with a modest 8 %
+doping. The adsorption of different concentrations on metal adatoms on graphene
+is also studied. Our calculations show that the adatoms prefer to relax at
+hollow sites. The transfer of electron from metallic dopants to the graphene
+for all the studied systems shifts the Fermi energy levels above the
+Dirac-point and the doped graphenes become metallic. The value of Fermi energy
+shifts depends on the type of metallic dopants and its concentrations. A detail
+analysis of the electronic structure in terms of band structure and density of
+states, absorption energy, and charge transfer for each adatom-graphene system
+is presented.",1706.00913v1
+2017-06-16,Fusion systems and localities -- a dictionary,"Linking systems were introduced to provide algebraic models for $p$-completed
+classifying spaces of fusion systems. Every linking system over a saturated
+fusion system $\mathcal{F}$ corresponds to a group-like structure called a
+locality. Given such a locality $\mathcal{L}$, we prove that there is a
+one-to-one correspondence between the partial normal subgroups of $\mathcal{L}$
+and the normal subsystems of the fusion system $\mathcal{F}$. This is then used
+to obtain a kind of dictionary, which makes it possible to translate between
+various concepts in localities and corresponding concepts in fusion systems. As
+a byproduct, we obtain new proofs of many known theorems about fusion systems
+and also some new results. For example, we show in this paper that, in any
+saturated fusion system, there is a sensible notion of a product of normal
+subsystems.",1706.05343v4
+2017-06-22,Magneto-resistance oscillations induced by high-intensity terahertz radiation,"We report on observation of pronounced terahertz radiation-induced
+magneto-resistivity oscillations in AlGaAs/GaAs two-dimensional electron
+systems, the THz analog of the microwave induced resistivity oscillations
+(MIRO). Applying high power radiation of a pulsed molecular laser we
+demonstrate that MIRO, so far observed at low power only, are not destroyed
+even at very high intensities. Experiments with radiation intensity ranging
+over five orders of magnitude from $0.1$ W/cm$^2$ to $10^4$ W/cm$^2$ reveal
+high-power saturation of the MIRO amplitude, which is well described by an
+empirical fit function $I/(1 + I/I_s)^\beta$ with $\beta \sim 1$. The
+saturation intensity Is is of the order of tens of W/cm$^2$ and increases by
+six times by increasing the radiation frequency from $0.6$ to $1.1$ THz. The
+results are discussed in terms of microscopic mechanisms of MIRO and compared
+to nonlinear effects observed earlier at significantly lower excitation
+frequencies.",1706.07239v1
+2017-06-22,A method for rapid determination of oil and water content in geological formations,"A novel method utilizing Fast Neutron Resonance Transmission Radiography is
+proposed for rapid, non-destructive and quantitative determination of the
+weight fractions of oil and water in cores taken from subterranean or
+underwater geological formations. Its ability to distinguish water from oil
+stems from the unambiguously-specific energy-dependence of the neutron
+cross-sections for the principal elemental constituents. Furthermore, the fluid
+weight fractions permit determining core porosity and oil and water
+saturations. In this article we show results of experimental determination of
+oil and water weight fractions in 10 cm thick samples of Berea Sandstone and
+Indiana Limestone formations, followed by calculation of their porosity and
+fluid saturations. The technique may ultimately permit rapid, accurate and
+non-destructive evaluation of relevant petro-physical properties in thick
+intact cores. It is suitable for all types of formations including tight
+shales, clays and oil sands.",1706.07689v1
+2017-07-02,Rate-Splitting for Max-Min Fair Multigroup Multicast Beamforming in Overloaded Systems,"In this paper, we consider the problem of achieving max-min fairness amongst
+multiple co-channel multicast groups through transmit beamforming. We
+explicitly focus on overloaded scenarios in which the number of transmitting
+antennas is insufficient to neutralize all inter-group interference. Such
+scenarios are becoming increasingly relevant in the light of growing
+low-latency content delivery demands, and also commonly appear in multibeam
+satellite systems. We derive performance limits of classical beamforming
+strategies using DoF analysis unveiling their limitations; for example, rates
+saturate in overloaded scenarios due to inter-group interference. To tackle
+interference, we propose a strategy based on degraded beamforming and
+successive interference cancellation. While the degraded strategy resolves the
+rate-saturation issue, this comes at a price of sacrificing all spatial
+multiplexing gains. This motivates the development of a unifying strategy that
+combines the benefits of the two previous strategies. We propose a beamforming
+strategy based on rate-splitting (RS) which divides the messages intended to
+each group into a degraded part and a designated part, and transmits a
+superposition of both degraded and designated beamformed streams. The
+superiority of the proposed strategy is demonstrated through DoF analysis.
+Finally, we solve the RS beamforming design problem and demonstrate significant
+performance gains through simulations.",1707.00304v1
+2017-07-05,Robust Multi-Image HDR Reconstruction for the Modulo Camera,"Photographing scenes with high dynamic range (HDR) poses great challenges to
+consumer cameras with their limited sensor bit depth. To address this, Zhao et
+al. recently proposed a novel sensor concept - the modulo camera - which
+captures the least significant bits of the recorded scene instead of going into
+saturation. Similar to conventional pipelines, HDR images can be reconstructed
+from multiple exposures, but significantly fewer images are needed than with a
+typical saturating sensor. While the concept is appealing, we show that the
+original reconstruction approach assumes noise-free measurements and quickly
+breaks down otherwise. To address this, we propose a novel reconstruction
+algorithm that is robust to image noise and produces significantly fewer
+artifacts. We theoretically analyze correctness as well as limitations, and
+show that our approach significantly outperforms the baseline on real data.",1707.01317v1
+2017-07-10,Probing Saturation Physics in the Real Compton Scattering at Ultraperipheral $pPb$ Collisions,"The Real Compton Scattering in ultraperipheral $pPb$ collisions at RHIC and
+LHC energies is investigated and predictions for the squared transverse
+momentum ($t$) and rapidity ($Y$) distributions are presented. The scattering
+amplitude is assumed to be given by the sum of the Reggeon and Pomeron
+contributions and the Pomeron one is described by the Color Dipole formalism
+taking into account the non - linear (saturation) effects in the QCD dynamics.
+We demonstrate that the behaviour of the cross sections at large -- $t$ and/or
+$Y$ is dominated by the Pomeron contribution and is strongly affected by the
+non -- linear effects present in the QCD dynamics. These results indicate that
+a future experimental analysis of this process can be useful to probe the QCD
+dynamics at high energies.",1707.02806v2
+2017-07-13,Non-integrability and Chaos with Unquenched Flavor,"We study (non-)integrability and the presence of chaos in gravity dual
+backgrounds of strongly coupled gauge theories with unquenched flavor,
+specifically of the four-dimensional N=2 super Yang-Mills theory and the
+three-dimensional ABJM theory. By examining string motion on the geometries
+corresponding to backreacted D3/D7 and D2/D6 systems, we show that integrable
+theories with quenched flavor become non-integrable when the virtual quark
+loops are taken into account. For the string solutions in the backreacted D3/D7
+system, we compute the leading Lyapunov exponent which turns out to saturate to
+a positive value as the number of flavors increases. The exponent depends very
+weakly on the number of flavors when they approach the number of colors. This
+suggests that once a particular flavor number in the theory is reached, a
+further increase does not lead to more severe chaotic phenomena, implying
+certain saturation effects on chaos.",1707.04033v2
+2017-07-25,Non-Saturated Throughput Analysis of Coexistence of Wi-Fi and Cellular With Listen-Before-Talk in Unlicensed Spectrum,"This paper analyzes the coexistence performance of Wi-Fi and cellular
+networks conditioned on non-saturated traffic in the unlicensed spectrum. Under
+the condition, the time-domain behavior of a cellular small-cell base station
+(SCBS) with a listen-before-talk (LBT) procedure is modeled as a Markov chain,
+and it is combined with a Markov chain which describes the time-domain behavior
+of a Wi-Fi access point. Using the proposed model, this study finds the optimal
+contention window size of cellular SCBSs in which total throughput of both
+networks is maximized while satisfying the required throughput of each network,
+under the given traffic densities of both networks. This will serve as a
+guideline for cellular operators with respect to performing LBT at cellular
+SCBSs according to the changes of traffic volumes of both networks over time.",1707.07843v1
+2017-07-26,Ground-state properties of unitary bosons: from clusters to matter,"The properties of cold Bose gases at unitarity have been extensively
+investigated in the last few years both theoretically and experimentally. In
+this paper we use a family of interactions tuned to two-body unitarity and very
+weak three-body binding to demonstrate the universal properties of both
+clusters and matter. We determine the universal properties of finite clusters
+up to 60 particles and, for the first time, explicitly demonstrate the
+saturation of energy and density with particle number and compare with bulk
+properties. At saturation in the bulk we determine the energy, density, two-
+and three-body contacts and the condensate fraction. We find that uniform
+matter is more bound than three-body clusters by nearly two orders of
+magnitude, the two-body contact is very large in absolute terms, and yet the
+condensate fraction is also very large, greater than 90%. Equilibrium
+properties of these systems may be experimentally accessible through rapid
+quenching of weakly-interacting boson superfluids.",1707.08546v2
+2017-07-27,Nominal vs. actual supersaturation of solutions,"Following the formalism of the Classical Nucleation Theory beyond the dilute
+solution approximation, this paper considers a difference between the actual
+solute supersaturation (given by the present-to-saturated solute activity
+ratio) and the nominal supersaturation (given by the present-to-saturated
+solute concentration ratio) due to formation of subcritical transient solute
+clusters, called heterophase fluctuations. Based on their distribution
+function, we introduce an algebraic equation of supersaturation that couples
+the nominal supersaturation of a binary metastable solution with its actual
+supersaturation and a function of the specific interface energy and
+temperature. The applicability of this approach is validated by comparison to
+simulation data [E. Clouet et al., Phys. Rev. B \textbf{69}, 064109 (2004)] on
+nucleation of Al$_{3}$Zr and Al$_{3}$Sc in model binary Al alloys.",1707.08777v3
+2017-07-27,Delta isobars and nuclear saturation,"We construct a nuclear interaction in chiral effective field theory with
+explicit inclusion of the $\Delta$-isobar $\Delta(1232)$ degree of freedom at
+all orders up to next-to-next-to-leading order (NNLO). We use pion-nucleon
+($\pi N$) low-energy constants (LECs) from a Roy-Steiner analysis of $\pi N$
+scattering data, optimize the LECs in the contact potentials up to NNLO to
+reproduce low-energy nucleon-nucleon scattering phase shifts, and constrain the
+three-nucleon interaction at NNLO to reproduce the binding energy and
+point-proton radius of $^{4}$He. For heavier nuclei we use the coupled-cluster
+method to compute binding energies, radii, and neutron skins. We find that
+radii and binding energies are much improved for interactions with explicit
+inclusion of $\Delta(1232)$, while $\Delta$-less interactions produce nuclei
+that are not bound with respect to breakup into $\alpha$ particles. The
+saturation of nuclear matter is significantly improved, and its symmetry energy
+is consistent with empirical estimates.",1707.09028v2
+2017-08-06,Power-law citation distributions are not scale-free,"We analyze time evolution of statistical distributions of citations to
+scientific papers published in one year. While these distributions can be
+fitted by a power-law dependence we find that they are nonstationary and the
+exponent of the power law fit decreases with time and does not come to
+saturation. We attribute the nonstationarity of citation distributions to
+different longevity of the low-cited and highly-cited papers. By measuring
+citation trajectories of papers we found that citation careers of the low-cited
+papers come to saturation after 10-15 years while those of the highly-cited
+papers continue to increase indefinitely: the papers that exceed some citation
+threshold become runaways. Thus, we show that although citation distribution
+can look as a power-law, it is not scale-free and there is a hidden dynamic
+scale associated with the onset of runaways. We compare our measurements to our
+recently developed model of citation dynamics based on
+copying/redirection/triadic closure and find explanations to our empirical
+observations.",1708.01859v1
+2017-08-08,"Degree of dimerization, effective polarizability of molecules and heat capacity of the saturated water vapor","The work is devoted to the investigation of properties of water vapor. The
+main attention is focused on the physical nature of its effective
+polarizability and heat capacity at constant volume. We show that the specific
+temperature dependencies of these characteristics are mainly caused by thermal
+vibration excitations of water dimers. In connection with this we determine
+normal coordinates for the dimer vibrations. We investigate fluctuations of the
+dipole moments of dimers in details and consider their contributions to the
+dielectric permittivity of the water vapor. We also took into account the
+contribution of the interparticle interactions on the heat capacity. Analyzing
+the behavior of the effective polarizability and heat capacity we defined the
+temperature dependence of the dimer concentration on the coexistence
+vapor-liquid curve. The noticeable dimerization in the saturated water vapor
+takes place only for temperatures T/Tc > 0.8 (Tc is the critical temperature).
+It is important to note that the successful reproduction of the effective
+polarizability and heat capacity can serve good test for the correct
+description of the dimer concentration in different approaches.",1708.02483v1
+2017-08-10,A linear domain decomposition method for partially saturated flow in porous media,"The Richards equation is a nonlinear parabolic equation that is commonly used
+for modelling saturated/unsaturated flow in porous media. We assume that the
+medium occupies a bounded Lipschitz domain partitioned into two disjoint
+subdomains separated by a fixed interface $\Gamma$. This leads to two problems
+defined on the subdomains which are coupled through conditions expressing flux
+and pressure continuity at $\Gamma$. After an Euler implicit discretisation of
+the resulting nonlinear subproblems a linear iterative ($L$-type) domain
+decomposition scheme is proposed. The convergence of the scheme is proved
+rigorously. In the last part we present numerical results that are in line with
+the theoretical finding, in particular the unconditional convergence of the
+scheme. We further compare the scheme to other approaches not making use of a
+domain decomposition. Namely, we compare to a Newton and a Picard scheme. We
+show that the proposed scheme is more stable than the Newton scheme while
+remaining comparable in computational time, even if no parallelisation is being
+adopted. Finally we present a parametric study that can be used to optimize the
+proposed scheme.",1708.03224v1
+2017-06-26,Conservation laws and constitutive equations for an electro-active polymer,"Ionic electro-active polymer (Nafion for example) can be used as sensor or
+actuator. To this end, a thin film of the water-saturated material is
+sandwiched between two electrodes. Water saturation causes a quasi-complete
+dissociation of the polymer and the release of small cations. The application
+of an electric field across the thickness results in the bending of the strip.
+Conversely, a voltage can be detected between the two electrodes when the strip
+is bent. This phenomenon involves multiphysics couplings of
+electro-mechanical-chemical type. The system is modeled by a deformable porous
+medium in which flows an ionic solution and we use a continuous medium
+approach. Maxwell's equations and conservation laws of mass, linear momentum
+and energy are first written at the microscopic scale for each phase and
+interfaces, then for the complete material using an average technique.
+Thermodynamics of linear irreversible processes provides the constitutive
+equations : a Kelvin-Voigt stress-strain relation,generalized Fourier's and
+Darcy's laws and a Nernst-Planck equation.",1708.05056v1
+2017-08-24,Nuclear symmetry energy with mesonic cross-couplings in the effective chiral model,"The effective chiral model is extended by introducing the contributions from
+the cross-couplings between isovector and isoscalar mesons. These
+cross-couplings are found to be instrumental in improving the density content
+of the nuclear symmetry energy. The nuclear symmetry energy as well as its
+slope and curvature parameters at the saturation density are in harmony with
+those deduced from a diverse set of experimental data. The equation of state
+for pure neutron matter at sub-saturation densities is also in accordance with
+the ones obtained from different microscopic models. The maximum mass of
+neutron star is consistent with the measurement and the radius at the canonical
+mass of the neutron star is within the empirical bounds.",1708.07291v1
+2017-08-30,Fast scrambling in holographic Einstein-Podolsky-Rosen pair,"We demonstrate that a holographic model of the Einstein-Podolsky-Rosen pair
+exhibits fast scrambling. Strongly entangled quark and antiquark in
+$\mathcal{N}=4$ super Yang-Mills theory are considered. Their gravity dual is a
+fundamental string whose endpoints are uniformly accelerated in opposite
+direction. We slightly increase the acceleration of the endpoint and show that
+it quickly destroys the correlation between the quark and antiquark. The proper
+time scale of the destruction is $\tau_\ast\sim \beta \ln S$ where $\beta$ is
+the inverse Unruh temperature and $S$ is the entropy of the accelerating quark.
+We also evaluate the Lyapunov exponent from correlation function as
+$\lambda_L=2\pi/\beta$, which saturates the Lyapunov bound. Our results suggest
+that the fast scrambling or saturation of the Lyapunov bound do not directly
+imply the existence of an Einstein dual. When we slightly decrease the
+acceleration, the quark and antiquark are causally connected and an ""one-way
+traversable wormhole"" is created on the worldsheet. It causes the divergence of
+the correlation function between the quark and antiquark.",1708.09493v2
+2017-09-04,Entropy production and isotropization in Yang-Mills theory with use of quantum distribution function,"We investigate thermalization process in relativistic heavy ion collisions in
+terms of the Husimi-Wehrl (HW) entropy defined with the Husimi function, a
+quantum distribution function in a phase space. We calculate the semiclassical
+time evolution of the HW entropy in Yang-Mills field theory with the
+phenomenological initial field configuration known as the McLerran-Venugopalan
+model in a non-expanding geometry, which has instabilty triggered by initial
+field fluctuations. HW-entropy production implies the thermalization of the
+system and it reflects the underlying dynamics such as chaoticity and
+instability. By comparing the production rate with the Kolmogorov-Sina\""i rate,
+we find that the HW entropy production rate is significantly larger than that
+expected from chaoticity. We also show that the HW entropy is finally saturated
+when the system reaches a quasi-stationary state. The saturation time of the HW
+entropy is comparable with that of pressure isotropization, which is around $1$
+fm/c in the present calculation in the non-expanding geometry.",1709.00979v1
+2017-09-04,Chaotic strings in AdS/CFT,"Holographic theories with classical gravity duals are maximally chaotic;
+i.e., they saturate the universal bound on the rate of growth of chaos. It is
+interesting to ask whether this property is true only for leading large $N$
+correlators or if it can show up elsewhere. In this Letter we consider the
+simplest setup to tackle this question: a Brownian particle coupled to a
+thermal ensemble. We find that the four-point out-of-time-order correlator that
+diagnoses chaos initially grows at an exponential rate that saturates the chaos
+bound, i.e., with a Lyapunov exponent $\lambda_L=2\pi/\beta$. However, the
+scrambling time is parametrically smaller than for plasma excitations,
+$t_*\sim\beta \log \sqrt{\lambda}$ instead of $t_*\sim\beta \log N^2$. Our
+result shows that, at least in certain cases, maximal chaos can be attained in
+the probe sector without the explicit need of gravitational degrees of freedom.",1709.01052v3
+2017-09-04,"On ill-posedness concepts, stable solvability and saturation","We consider different concepts of well-posedness and ill-posedness and their
+relations for solving nonlinear and linear operator equations in Hilbert
+spaces. First, the concepts of Hadamard and Nashed are recalled which are
+appropriate for linear operator equations. For nonlinear operator equations,
+stable respective unstable solvability is considered, and the properties of
+local well-posedness and ill-posedness are investigated. Those two concepts
+consider stability in image space and solution space, respectively, and both
+seem to be appropriate concepts for nonlinear operators which are not onto
+and/or not, locally or globally, injective. Several example situations for
+nonlinear problems are considered, including the prominent autoconvolution
+problems and other quadratic equations in Hilbert spaces.
+  It turns out that for linear operator equations, well-posedness and
+ill-posedness are global properties valid for all possible solutions,
+respectively. The special role of the nullspace is pointed out in this case.
+  Finally, non-injectivity also causes differences in the saturation behavior
+of Tikhonov and Lavrentiev regularization of linear ill-posed equations. This
+is examined at the end of this study.",1709.01109v1
+2017-09-13,Mirror-assisted coherent backscattering from the Mollow sidebands,"In front of a mirror, the radiation of weakly driven large disordered clouds
+presents an interference fringe in the backward direction, on top of an
+incoherent background. Although strongly driven atoms usually present little
+coherent scattering, we here show that the mirror-assisted version can produce
+high contrast fringes, for arbitrarily high saturation parameters. The contrast
+of the fringes oscillates with the Rabi frequency of the atomic transition and
+the distance between the mirror and the atoms, due to the coherent interference
+between the carrier and the Mollow sidebands of the saturated resonant
+fluorescence spectrum emitted by the atoms. The setup thus represents a
+powerful platform to study the spectral properties of ensembles of correlated
+scatterers.",1709.04529v1
+2017-09-20,The Saturated and Supercritical Stirling Cycle Thermodynamic Heat Engine Cycle,"On the assumption that experimentally validated tabulated thermodynamic
+properties of saturated fluids published by the National Institute of Standards
+and Technology are accurate, a theoretical thermodynamic cycle can be
+demonstrated that produces a net-negative entropy generation to the universe.
+The experimental data on the internal energy can also be used to obtain a
+simple, empirical equation for the change in internal energy of a real fluid
+undergoing isothermal expansion and compression. This demonstration provides
+experimental evidence to the theory that temperature-dependent intermolecular
+attractive forces can be an entropic force that can enhance the thermodynamic
+efficiency of a real-fluid macroscopic heat engine to exceed that of the Carnot
+efficiency.",1709.06852v4
+2017-09-24,Regge phenomenology of photoproduction of $π^-Δ^{++}$ and scaling with saturation of trajectory,"In this work we investigate the reaction $\gamma p\to\pi^-\Delta^{++}$ in the
+Reggeized model for $\pi(138)+\rho(775)+a_2(1320)$ exchanges in the
+$t$-channel. For a convergence of the reaction cross section at high energies
+the minimal forms of proton and $\Delta^{++}$ exchanges are introduced in the
+direct and crossed channels for gauge invariance of $\pi$ Regge-pole exchange.
+The role of spin-2 tensor meson $a_2$ is found to be crucial to agree with
+existing data at high energies. Electromagnetic multipoles of $\Delta^{++}$
+baryon are analyzed in the $\Delta$ resonance region. Based on the constituents
+counting rule the scaled differential cross section at $E_\gamma=4$ GeV is
+reproduced with the Regge trajectory saturated at large momentum transfer $-t$.",1709.08175v2
+2017-09-25,Theoretical analysis of electrostatic energy harvester configured as Bennet's doubler based on Q-V cycles,"This paper presents theoretical analysis of a MEMS electrostatic energy
+harvester configured as the Bennet's doubler. Steady-state operation of the
+doubler circuit can be approximated by a right-angled trapezoid Q-V cycle. A
+similarity between voltage doubler and resistive-based charge-pump circuit is
+highlighted. By taking electromechanical coupling into account, the analytical
+solution of the saturation voltage is the first time derived, providing a
+greater comprehension of the system performance and multi-parameter effects.
+The theoretical approach is verified by results of circuit simulation for two
+cases of mathematically idealized diode and of Schottky diode. Development of
+the doubler/multiplier circuits that can further increase the saturation
+voltage is investigated.",1709.08754v1
+2017-10-13,Fermi-momentum dependence of relativistic effective mass below saturation from superscaling of quasielastic electron scattering,"The relativistic effective mass $M^*$, and Fermi momentum, $k_F$, are
+important ingredients in the determination of the nuclear equation of state,
+but they have rarely been extracted from experimental data below saturation
+density where translationally invariant nuclear matter becomes unstable against
+clusterization into the existing atomic nuclei. Using a novel kind of
+superscaling analysis of the quasielastic cross section electron scattering
+data involving a suitable selection criterion and $^{12}$C as a reference
+nucleus, the global scaling properties of the resulting set of data for 21
+nuclei ranging from $^2$H to $^{238}$U are then analyzed. We find that a subset
+of a third of the about $20000$ data approximately scales to an universal
+superscaling function with a more constrained uncertainty band than just the
+reference $^{12}$C case and provides $M^*$ as a function of $k_F$.",1710.04988v1
+2017-10-14,Gassmann Theory Applies to Nanoporous Media,"Recent progress in extraction of unconventional hydrocarbon resources has
+ignited the interest in the studies of nanoporous media. Since many
+thermodynamic and mechanical properties of nanoscale solids and fluids differ
+from the analogous bulk materials, it is not obvious whether wave propagation
+in nanoporous media can be described using the same framework as in macroporous
+media. Here we test the validity of Gassmann equation using two published sets
+of ultrasonic measurements for a model nanoporous medium, Vycor glass,
+saturated with two different fluids, argon and n-hexane. Predictions of the
+Gassmann theory depend on the bulk and shear moduli of the dry samples, which
+are known from ultrasonic measurements, and the bulk moduli of the solid and
+fluid constituents. The solid bulk modulus can be estimated from
+adsorption-induced deformation or from elastic effective medium theory. The
+fluid modulus can be calculated according to the Tait-Murnaghan equation at the
+solvation pressure in the pore. Substitution of these parameters into the
+Gassmann equation provides predictions consistent with measured data. Our
+findings set up a theoretical framework for investigation of fluid-saturated
+nanoporous media using ultrasonic elastic wave propagation.",1710.05216v2
+2017-10-20,Extremal problems on saturation for the family of $k$-edge-connected graphs,"Let $\mathcal{F}$ be a family of graphs. A graph $G$ is
+$\mathcal{F}$-saturated if $G$ contains no member of $\mathcal{F}$ as a
+subgraph but $G+e$ contains some member of $\mathcal{F}$ whenever $e\in
+E(\overline{G})$. The saturation number and extremal number of $\mathcal{F}$,
+denoted $sat(n,\mathcal{F})$ and $ex(n,\mathcal{F})$ respectively, are the
+minimum and maximum numbers of edges among $n$-vertex $\mathcal{F}$-saturated
+graphs. For $k\in\mathbb{N}$, let $\mathcal{F}_k$ and $\mathcal{F}'_k$ be the
+families of $k$-connected and $k$-edge-connected graphs, respectively. Wenger
+proved $sat(n,\mathcal{F}_k)=(k-1)n-{k\choose2}$, we prove
+$sat(n,\mathcal{F}'_k)=(k-1)(n-1)-\lfloor{\frac {n}{k+1}}\rfloor{k-1 \choose
+2}$. We also prove $ex(n,\mathcal{F}'_k)=(k-1)n-{k\choose2}$ and characterize
+when equality holds. Finally, we give a lower bound on the spectral radius for
+$\mathcal{F}_k$-saturated and $\mathcal{F}'_k$-saturated graphs.",1710.07432v2
+2017-10-23,Chiral interactions up to next-to-next-to-next-to-leading order and nuclear saturation,"We present an efficient Monte Carlo framework for perturbative calculations
+of infinite nuclear matter based on chiral two-, three-, and four-nucleon
+interactions. The method enables the incorporation of all many-body
+contributions in a straightforward and transparent way, and makes it possible
+to extract systematic uncertainty estimates by performing order-by-order
+calculations in the chiral expansion as well as the many-body expansion. The
+versatility of this new framework is demonstrated by applying it to chiral
+low-momentum interactions, exhibiting a very good many-body convergence up to
+fourth order. Following these benchmarks, we explore new chiral interactions up
+to next-to-next-to-next-to-leading order (N$^3$LO). Remarkably, simultaneous
+fits to the triton and to saturation properties can be achieved, while all
+three-nucleon low-energy couplings remain natural. The theoretical
+uncertainties of nuclear matter are significantly reduced when going from
+next-to-next-to-leading order to N$^3$LO.",1710.08220v3
+2017-10-26,Saturation of the Quantum Null Energy Condition in Far-From-Equilibrium Systems,"The Quantum Null Energy Condition (QNEC) is a new local energy condition that
+a general Quantum Field Theory (QFT) is believed to satisfy, relating the
+classical null energy condition (NEC) to the second functional derivative of
+the entanglement entropy in the corresponding null direction. We present the
+first series of explicit computations of QNEC in a strongly coupled QFT, using
+holography. We consider the vacuum, thermal equilibrium, a homogeneous
+far-from-equilibrium quench as well as a colliding system that violates NEC.
+For vacuum and the thermal phase QNEC is always weaker than NEC. While for the
+homogeneous quench QNEC is satisfied with a finite gap, we find the interesting
+result that the colliding system can saturate QNEC, depending on the null
+direction.",1710.09837v1
+2017-11-06,On classes of finite groups with simple non-abelian chief factors,"Let $\mathfrak{J}$ be a class of non-abelian simple groups and $\mathfrak{X}$
+be a class of groups. A chief factor $H/K$ of a group $G$ is called
+$\mathfrak{X}$-central in $G$ provided $(H/K)\rtimes
+G/C_G(H/K)\in\mathfrak{X}$. We say that $G$ is a
+$\mathfrak{J}cs$-$\mathfrak{X}$-\emph{group} if every chief
+$\mathfrak{X}$-factor of $G$ is $\mathfrak{X}$-central and other chief factors
+of $G$ are simple $\mathfrak{J}$-groups. We use $\mathfrak{X}_{\mathfrak{J}cs}$
+to denote the class of all $\mathfrak{J}cs$-$\mathfrak{X}$-groups. A subgroup
+$U$ of a group $G$ is called $\mathfrak{X}$-\emph{maximal} in $G$ provided that
+$(a)$ $U\in\mathfrak{X}$, and $(b)$ if $U\leq V \leq G$ and $V\in\mathfrak{X}$,
+then $U = V$. In this paper we described the structure of
+$\mathfrak{J}cs$-$\mathfrak{H}$-groups for a solubly saturated formation
+$\mathfrak{H}$ and all hereditary saturated formations $\mathfrak{F}$
+containing all nilpotent groups such that the
+$\mathfrak{F}_{\mathfrak{J}cs}$-hypercenter of $G$ coincides with the
+intersection of all $\mathfrak{F}_{\mathfrak{J}cs}$-maximal subgroups of $G$
+for every group $G$.",1711.01686v1
+2017-11-07,Dominant Kinetic Pathways of Graphene Growth in Chemical Vapor Deposition: The Role of Hydrogen,"The most popular way to produce graphene nowadays is chemical vapor
+deposition, where, surprisingly, H$_2$ gas is routinely supplied even though it
+is a byproduct itself. In this study, by identifying dominant growing pathways
+via multiscale simulations, we unambiguously reveal the central role hydrogen
+played in graphene growth. Hydrogen can saturate the edges of a growing
+graphene island to some extent, depending on the H$_2$ pressure. Although
+graphene etching by hydrogen has been observed in experiment, hydrogen
+saturation actually stabilizes graphene edges by reducing the detachment rates
+of carbon-contained species. Such a new picture well explains some puzzling
+experimental observations and is also instrumental in growth protocol
+optimization for two-dimensional atomic crystal van der Waals epitaxy.",1711.02244v1
+2017-12-11,Strangeness Production in low energy Heavy Ion Collisions via Hagedorn Resonances,"A novel, unorthodox picture of the dynamics of heavy ion collisions is
+developed using the concept of Hagedorn states. A prescription of the bootstrap
+of Hagedorn states respecting the conserved quantum numbers baryon number B,
+strangeness S, isospin I is implememted into the GiBUU transport model. Using a
+strangeness saturation suppression factor suitable for
+nucleon-nucleon-collisions, recent experimental data for the strangeness
+production by the HADES collaboration in Au+Au and Ar+KCl is reasonable well
+described. The experimental observed exponential slopes of the energy
+distributions are nicely reproduced. Thus, a dynamical model using Hagedorn
+resonance states, supplemented by a strangeness saturation suppression factor,
+is able to explain essential features (multiplicities, exponential slope) of
+experimental data for strangeness production in nucleus-nucleus collisions
+close to threshold.",1712.04018v2
+2017-12-13,Tensor Fermi liquid parameters in nuclear matter from chiral effective field theory,"We compute from chiral two- and three-body forces the complete quasiparticle
+interaction in symmetric nuclear matter up to twice nuclear matter saturation
+density. Second-order perturbative contributions that account for
+Pauli-blocking and medium polarization are included, allowing for an
+exploration of the full set of central and noncentral operator structures
+permitted by symmetries and the long-wavelength limit. At the Hartree-Fock
+level, the next-to-next-to-leading order three-nucleon force contributes to all
+noncentral interactions, and their strengths grow approximately linearly with
+the nucleon density up that of saturated nuclear matter. Three-body forces are
+shown to enhance the already strong proton-neutron effective tensor
+interaction, while the corresponding like-particle tensor force remains small.
+We also find a large isovector cross-vector interaction but small
+center-of-mass tensor interactions in the isoscalar and isovector channels. The
+convergence of the expansion of the noncentral quasiparticle interaction in
+Landau parameters and Legendre polynomials is studied in detail.",1712.05013v1
+2017-12-15,Predictions on three-particle azimuthal correlations in proton-proton collisions,"The ridge signal, which is long-ranged in rapidity, in the di-hadron
+correlations in high-multiplicity p-p and p-A collisions opened up a whole new
+research area in high-energy QCD. Although the ridge had been observed in A-A
+collisions and interpreted as a result of the radial flow of quark-gluon
+plasma, it had not appeared until recently in the data of small collision
+systems such as p-p and p-A, nor had it been predicted theoretically or seen in
+the event generators. There are two competing approaches that attempt to
+explain the systematics of the di-hadron ridge signal; hydrodynamics and gluon
+saturation physics (color glass condensate/glasma). In this work, we present
+predictions for the transverse momentum and rapidity dependence of the
+three-particle correlation function within the gluon saturation physics.
+Tri-hadron correlations can be measured, and the data can possibly rule out one
+of the two alternative approaches.",1712.05571v1
+2017-12-20,Influence of the nuclear matter equation of state on the r-mode instability using the finite-range simple effective interaction,"The characteristic physical properties of rotating neutron stars under the
+r-mode oscillation are evaluated using the finite-range simple effective
+interaction. Emphasis is given on examining the influence of the stiffness of
+both the symmetric and asymmetric parts of the nuclear equation of state on
+these properties. The amplitude of the r-mode at saturation is calculated using
+the data of particular neutron stars from the considerations of ""spin
+equilibrium"" and ""thermal equilibrium"". The upper limit of the r-mode
+saturation amplitude is found to lie in the range 10^{-8}-10^{-6}, in agreement
+with the predictions of earlier work.",1712.07273v1
+2017-12-31,Estimation of Gaussian quantum states,"We derive several expressions for the quantum Fisher information matrix
+(QFIM) for the multi-parameter estimation of multi-mode Gaussian quantum
+states, the corresponding symmetric logarithmic derivatives, and conditions for
+saturability of the quantum Cram\'{e}r-Rao bound. This bound determines the
+ultimate precision with which parameters encoded into quantum states can be
+estimated. We include expressions for mixed states, for the case when the
+Williamson decomposition of the covariance matrix is known, expressions in
+terms of infinite series, and expressions for pure states. We also discuss
+problematic behavior when some modes are pure, and present a method that allows
+the use of expressions that are defined only for mixed states, to compute QFIM
+for states with any number of pure modes.",1801.00299v4
+2018-01-06,Massive neutron star with strangeness in a relativistic mean-field model with a high-density cut-off,"The properties of strangeness neutron star are studied within relativistic
+mean-field (RMF) model via including a logarithmic interaction as a function of
+scalar meson field. This logarithmic interaction, named as the $\sigma$-cut
+potential, can largely reduce the attractive contributions of scalar meson
+field at high density without any influence on nuclear structure around normal
+saturation density. In this work, the TM1 parameter set is chosen as the RMF
+interaction, while the strengths of logarithmic interaction are constrained by
+the properties of finite nuclei so that we can obtain a reasonable effective
+nucleon-nucleon interaction. The hyperons, $\Lambda,~\Sigma$, and $\Xi$ are
+also considered in neutron stars within this framework, whose coupling
+constants with mesons are determined by the latest hyperon-nucleon and
+$\Lambda$-$\Lambda$ potentials extracted from the experimental data of
+hypernuclei. The maximum mass of neutron star can be larger than two solar mass
+with these hyperons. Furthermore, the nucleon mass at high density will be
+saturated due to this additional $\sigma$-cut potential, which is consistent
+with the conclusions from the microscopic calculations such as,
+Brueckner-Hartree-Fock theory and quark mean-field model.",1801.01984v1
+2018-01-09,Fake Colorized Image Detection,"Image forensics aims to detect the manipulation of digital images. Currently,
+splicing detection, copy-move detection and image retouching detection are
+drawing much attentions from researchers. However, image editing techniques
+develop with time goes by. One emerging image editing technique is
+colorization, which can colorize grayscale images with realistic colors.
+Unfortunately, this technique may also be intentionally applied to certain
+images to confound object recognition algorithms. To the best of our knowledge,
+no forensic technique has yet been invented to identify whether an image is
+colorized. We observed that, compared to natural images, colorized images,
+which are generated by three state-of-the-art methods, possess statistical
+differences for the hue and saturation channels. Besides, we also observe
+statistical inconsistencies in the dark and bright channels, because the
+colorization process will inevitably affect the dark and bright channel values.
+Based on our observations, i.e., potential traces in the hue, saturation, dark
+and bright channels, we propose two simple yet effective detection methods for
+fake colorized images: Histogram based Fake Colorized Image Detection
+(FCID-HIST) and Feature Encoding based Fake Colorized Image Detection
+(FCID-FE). Experimental results demonstrate that both proposed methods exhibit
+a decent performance against multiple state-of-the-art colorization approaches.",1801.02768v2
+2018-01-20,Boundary-based Image Forgery Detection by Fast Shallow CNN,"Image forgery detection is the task of detecting and localizing forged parts
+in tampered images. Previous works mostly focus on high resolution images using
+traces of resampling features, demosaicing features or sharpness of edges.
+However, a good detection method should also be applicable to low resolution
+images because compressed or resized images are common these days. To this end,
+we propose a Shallow Convolutional Neural Network(SCNN), capable of
+distinguishing the boundaries of forged regions from original edges in low
+resolution images. SCNN is designed to utilize the information of chroma and
+saturation. Based on SCNN, two approaches that are named Sliding Windows
+Detection (SWD) and Fast SCNN, respectively, are developed to detect and
+localize image forgery region. In this paper, we substantiate that Fast SCNN
+can detect drastic change of chroma and saturation. In image forgery detection
+experiments Our model is evaluated on the CASIA 2.0 dataset. The results show
+that Fast SCNN performs well on low resolution images and achieves significant
+improvements over the state-of-the-art.",1801.06732v2
+2018-01-23,Transport Dynamics of Parton Interactions in pp Collisions at LHC Energies,"We investigate the transport dynamics of partons in proton-proton collisions
+at the Large Hadron Collider using a Boltzmann transport approach, the parton
+cascade model. The calculations include semi-hard pQCD interaction of partons
+populating the nucleons and provide a space-time description of the collision
+in terms of cascading partons undergoing scatterings and fragmentations. Parton
+production and number of collisions rise rapidly with increase in center of
+mass energy of the collision. For a given center of mass energy, the number of
+parton interactions is seen to rise stronger than linear with decreasing impact
+parameter before saturating for very central collisions. The strangeness
+enhance factor $\gamma_s$ for the semi-hard processes is found to rise rapidly
+and saturate towards the highest collision energies. Overall, our study
+indicates a significant amount of partonic interactions in proton-proton
+collisions, which supports the observation of fluid-like behavior for high
+multiplicity proton-proton collisions observed in the experiments.",1801.07482v1
+2018-02-19,Complexity Growth with Lifshitz Scaling and Hyperscaling Violation,"Using complexity=action proposal we study the growth rate of holographic
+complexity for Lifshitz and hyperscaling violating geometries. We will consider
+both one and two sided black branes in an Einstein-Maxwell-Dilaton
+gravitational theory. We find that in either case Lloyd's bound is violated and
+the rate of growth of complexity saturates to a value which is greater than
+twice the mass of the corresponding black brane. This value reduces to the mass
+of the black brane in the isotropic case. We show that in two sided black brane
+the saturation happens from above while for one sided black brane it happens
+from below.",1802.06740v4
+2018-02-22,Shear strength of wet granular materials: macroscopic cohesion and effective stress,"Rheometric measurements on assemblies of wet polystyrene bead assemblies, in
+steady uniform quasistatic shear flow, for varying liquid content within the
+small saturation (pendular) range of isolated liquid bridges, are supplemented
+with a systematic study by discrete numerical simulations. Numerical results
+and experimental ones agree quantitatively is the intergranular friction
+coefficient is set to 0.09, suitable for the dry material. Shear resistance and
+solid fraction are recorded as functions of the reduced pressure p, comparing
+normal stress to capillary bridge tensile strength. The Mohr-Coulomb relation
+with p-independent cohesion c applies for p above 2. The assumption that
+contact force contributions to stress act as effective stresses predicts shear
+strength quite well throughout the numerically investigated range of
+parameters.. A generalized Mohr-Coulomb cohesion c is defined, which relates to
+the dry material internal friction, coordination numbers and capillary force
+network anisotropy. The Rumpf formula approximation, ignoring capillary shear
+stress is correct for the larger saturation range within the pendular regime,
+but fails to describe its decrease for small liquid contents.",1802.08172v1
+2018-02-22,Exponentially fast dynamics of chaotic many-body systems,"We demonstrate analytically and numerically that in isolated quantum systems
+of many interacting particles, the number of many-body states participating in
+the evolution after a quench increases exponentially in time, provided the
+eigenstates are delocalized in the energy shell. The rate of the exponential
+growth is defined by the width $\Gamma$ of the local density of states (LDOS)
+and is associated with the Kolmogorov-Sinai entropy for systems with a well
+defined classical limit. In a finite system, the exponential growth eventually
+saturates due to the finite volume of the energy shell. We estimate the time
+scale for the saturation and show that it is much larger than $\hbar/\Gamma$.
+Numerical data obtained for a two-body random interaction model of bosons and
+for a dynamical model of interacting spin-1/2 particles show excellent
+agreement with the analytical predictions.",1802.08265v2
+2018-02-26,An Energy Balance Based Method for Parameter Identification of a Free-Flying Robot Grasping An Unknown Object,"The estimation of inertial parameters of a robotic system is crucial for
+better trajectory tracking performance, specially when model-based controllers
+are used for carrying out precise tasks. In this paper, we consider the
+scenario of grasping an object of unknown properties by a free-flyer space
+robot with limited actuation. The problem is to find the inertial parameters of
+the complete system after grasping has been performed. Excitation is provided
+in inertial space, and the excitation trajectories are found by optimization.
+Truncated Fourier series are used to represent the reference as well as tracked
+trajectory. An approach based on the energy balance between the actuation work
+and the rate of change of kinetic energy is introduced to calculate the number
+of harmonics in the Fourier series used to represent the executed trajectory,
+while trying to find a balance between accounting for saturation effects and
+keeping out noise. The effect of input saturation on parameter estimation is
+also studied. Simulation results using the Space CoBot free-flyer robot are
+presented to show the feasibility of the approach.",1802.09338v2
+2018-02-27,"Hot and Dense Homogeneous Nucleonic Matter Constrained by Observations, Experiment, and Theory","We construct a new class of phenomenological equations of state for
+homogeneous matter for use in simulations of hot and dense matter in local
+thermodynamic equilibrium. We construct a functional form which respects
+experimental, observational and theoretical constraints on the nature of matter
+in various density and temperature regimes. Our equation of state matches (i)
+the virial coefficients expected from nucleon-nucleon scattering phase shifts,
+(ii) experimental measurements of nuclear masses and charge radii, (iii)
+observations of neutron star radii, (iv) theory results on the equation of
+state of neutron matter near the saturation density, and (v) theory results on
+the evolution of the EOS at finite temperatures near the saturation density.
+Our analytical model allows one to compute the variation in the thermodynamic
+quantities based on the uncertainties in the nature of the nucleon-nucleon
+interaction. Finally, we perform a correction to ensure the equation of state
+is causal at all densities, temperatures, and electron fractions.",1802.09710v1
+2018-03-06,Impact of the electron to ion mass ratio on unstable systems in particle-in-cell simulations,"The evolution of the Buneman and two-stream instabilities driven by a cold
+dilute mildly relativistic electron beam is studied as a function of the
+ion\'\s charge-to-mass ratio. The growth rates of both instabilities are
+comparable for the selected parameters if the charge-to-mass ratio of protons
+is used and the Buneman instability outgrows the two-stream instability for a
+larger ratio. Particle-in-cell (PIC) simulations show that both instabilities
+grow independently during their linear growth phase. The much lower saturation
+amplitude of the Buneman instability implies that it saturates first even if
+the linear growth rates of both instabilities are equal. The electron phase
+space holes it drives coalesce. Their spatial size increases in time and they
+start interacting with the two-stream mode, which triggers the onset of
+electrostatic turbulence. A reduced charge-to-mass ratio results in stronger
+turbulence and ion heating and in an increased energy loss of the relativistic
+electron beam compared to that in a simulation with the correct ratio.",1803.02190v2
+2018-03-07,Saturation and negative temperature coefficient of electrical resistivity in liquid iron-sulfur alloys at high densities from first principles calculations,"We report results on electronic transport properties of liquid Fe-S alloys at
+conditions of planetary cores, computed by first-principle techniques in the
+Kubo-Greenwood formalism. We describe a combined effect of resistivity
+saturation due to temperature, compression, and chemistry by comparing the
+electron mean free path from the Drude response of optical conductivity to the
+mean interatomic distance. At high compression and high sulfur concentration
+the Ioffe-Regel condition is satisfied, and the temperature coefficient of
+resistivity changes sign from positive to negative. We show that this happens
+due to a decrease of the $d$-density of states at the Fermi level in response
+to thermal broadening.",1803.02649v1
+2018-03-08,Learning Effective Binary Visual Representations with Deep Networks,"Although traditionally binary visual representations are mainly designed to
+reduce computational and storage costs in the image retrieval research, this
+paper argues that binary visual representations can be applied to large scale
+recognition and detection problems in addition to hashing in retrieval.
+Furthermore, the binary nature may make it generalize better than its
+real-valued counterparts. Existing binary hashing methods are either two-stage
+or hinging on loss term regularization or saturated functions, hence converge
+slowly and only emit soft binary values. This paper proposes Approximately
+Binary Clamping (ABC), which is non-saturating, end-to-end trainable, with fast
+convergence and can output true binary visual representations. ABC achieves
+comparable accuracy in ImageNet classification as its real-valued counterpart,
+and even generalizes better in object detection. On benchmark image retrieval
+datasets, ABC also outperforms existing hashing methods.",1803.03004v1
+2018-03-11,Bulk Matter and the Boundary Quantum Null Energy Condition,"We investigate the quantum null energy condition (QNEC) in holographic CFTs,
+focusing on half-spaces and particular classes of states. We present direct,
+and in certain cases nonperturbative, calculations for both the diagonal and
+off- diagonal variational derivatives of entanglement entropy. In d > 2, we
+find that the QNEC is saturated. We compute relations between the off-diagonal
+variation of entanglement, boundary relative entropy, and the bulk stress
+tensor. Strong subadditivity then leads to energy conditions in the bulk. In d
+= 2, we find that the QNEC is in general not saturated when the Ryu-Takayanagi
+surface intersects bulk matter. Moreover, when bulk matter is present the QNEC
+can imply new bulk energy conditions. For a simple class of states, we derive
+an example that is stronger than the bulk averaged null energy condition and
+reduces to it in certain limits.",1803.03997v1
+2018-03-22,Geometrical scaling description for the exclusive production of vector mesons and deeply virtual Compton scattering,"In this work, we investigate the exclusive production of particles in
+scattering processes in the so-called saturation region. Within this scheme the
+phenomenon of geometric scaling takes place: cross sections are functions only
+of a dimensionless combination of the relevant kinematic variables, which
+happens both in inclusive and diffractive cases, as in the production of vector
+mesons. In particular, the scaling variable is given in general by $\tau =
+Q^2/Q_s^2$, where $Q^2$ is the photon virtuality and $Q_s$ represents the
+saturation scale, which drives the energy dependence and the corresponding
+nuclear effects. Based on the scaling property, we are able to derive a
+universal expression for the cross sections for the exclusive vector meson
+production and deeply virtual Compton scattering (DVCS) in both photon-proton
+and photon-nucleus interactions. This phenomenological result describes all
+available data from DESY-HERA for $\rho$, $\phi$ and $J/\psi$ production and
+DVCS measurements. A discussion is also carried out on the size of nuclear
+shadowing corrections on photon-nucleus interaction.",1803.08442v2
+2018-03-25,Connectivity-Preserving Consensus of Multi-Agent Systems with Bounded Actuation,"This paper investigates the impact of bounded actuation on the
+connectivity-preserving consensus of two classes of multi-agent systems, with
+kinematic agents and with Euler- Lagrange agents. The investigation establishes
+that: (1) there exists a class of gradient-based controls which drive kinematic
+multi-agent systems to connectivity-preserving consensus even if they saturate;
+(2) actuator saturation restricts the initial states from which Euler-Lagrange
+multi-agent systems can be synchronized while preserving their local
+connectivity; (3) Euler-Lagrange multi-agent systems with unbounded actuation
+can achieve connectivity-preserving consensus without velocity measurements or
+exact system dynamics; and (4) a proposed indirect coupling control strategy
+drives Euler-Lagrange multi-agent systems with limited actuation and starting
+from rest to connectivitypreserving consensus without requiring velocity
+measurements and including in the presence of uncertain dynamics and
+timevarying delays.",1803.09309v1
+2018-03-31,Evolution of complexity following a quantum quench in free field theory,"Using a recent proposal of circuit complexity in quantum field theories
+introduced by Jefferson and Myers, we compute the time evolution of the
+complexity following a smooth mass quench characterized by a time scale $\delta
+t$ in a free scalar field theory. We show that the dynamics has two distinct
+phases, namely an early regime of approximately linear evolution followed by a
+saturation phase characterized by oscillations around a mean value. The
+behavior is similar to previous conjectures for the complexity growth in
+chaotic and holographic systems, although here we have found that the
+complexity may grow or decrease depending on whether the quench increases or
+decreases the mass, and also that the time scale for saturation of the
+complexity is of order $\delta t$ (not parametrically larger).",1804.00107v3
+2018-04-02,Joint Tx Power Allocation and Rx Power Splitting for SWIPT System with Multiple Nonlinear Energy Harvesting Circuits,"We study the joint transmit (Tx) power allocation and receive (Rx) power
+splitting for simultaneous wireless information and power transfer (SWIPT).
+Considering the practical scenario of nonlinear energy harvesting (EH), we
+adopt the realistic nonlinear EH model for analysis. To address the critical
+nonlinearity issue due to the saturation, we propose to use multiple EH
+circuits in parallel. An important problem is to maximize the achievable rate
+by jointly optimizing Tx power allocation and Rx power splitting, which is a
+nonconvex problem. In this paper, we first derive the optimal solution for any
+number of EH circuits. Then we study how the number of EH circuits required to
+avoid the saturation should be determined. From the obtained results, we draw
+useful and interesting insights into the SWIPT system with nonlinear EH.
+Numerical results demonstrate that employing multiple EH circuits substantially
+enhances the SWIPT performance with nonlinear EH.",1804.00387v1
+2018-03-16,Semantic Adversarial Examples,"Deep neural networks are known to be vulnerable to adversarial examples,
+i.e., images that are maliciously perturbed to fool the model. Generating
+adversarial examples has been mostly limited to finding small perturbations
+that maximize the model prediction error. Such images, however, contain
+artificial perturbations that make them somewhat distinguishable from natural
+images. This property is used by several defense methods to counter adversarial
+examples by applying denoising filters or training the model to be robust to
+small perturbations.
+  In this paper, we introduce a new class of adversarial examples, namely
+""Semantic Adversarial Examples,"" as images that are arbitrarily perturbed to
+fool the model, but in such a way that the modified image semantically
+represents the same object as the original image. We formulate the problem of
+generating such images as a constrained optimization problem and develop an
+adversarial transformation based on the shape bias property of human cognitive
+system. In our method, we generate adversarial images by first converting the
+RGB image into the HSV (Hue, Saturation and Value) color space and then
+randomly shifting the Hue and Saturation components, while keeping the Value
+component the same. Our experimental results on CIFAR10 dataset show that the
+accuracy of VGG16 network on adversarial color-shifted images is 5.7%.",1804.00499v1
+2018-04-03,Inhibition of the photoinduced structural phase transition in the excitonic insulator Ta$_2$NiSe$_5$,"Femtosecond time-resolved mid-infrared reflectivity is used to investigate
+the electron and phonon dynamics occurring at the direct band gap of the
+excitonic insulator Ta$_2$NiSe$_5$ below the critical temperature of its
+structural phase transition. We find that the phonon dynamics show a strong
+coupling to the excitation of free carriers at the \Gamma\ point of the
+Brillouin zone. The optical response saturates at a critical excitation fluence
+$F_C = 0.30~\pm~0.08$~mJ/cm$^2$ due to optical absorption saturation. This
+limits the optical excitation density in Ta$_2$NiSe$_5$ so that the system
+cannot be pumped sufficiently strongly to undergo the structural change to the
+high-temperature phase. We thereby demonstrate that Ta$_2$NiSe$_5$ exhibits a
+blocking mechanism when pumped in the near-infrared regime, preventing a
+nonthermal structural phase transition.",1804.00882v1
+2018-04-09,Exclusive vector meson production with leading neutrons in a saturation model for the dipole amplitude in mixed space,"We investigate $\rho$ vector meson production in $ep$ collisions at HERA with
+leading neutrons in the dipole formalism. The interaction of the dipole and the
+pion is described in a mixed-space approach, in which the dipole-pion
+scattering amplitude is given by the Marquet-Peschanski-Soyez saturation model,
+which is based on the travelling wave solutions of the nonlinear
+Balitsky-Kovchegov equation. We estimate the magnitude of the absorption
+effects and compare our results with a previous analysis of the same process in
+full coordinate space. In contrast with this approach, the present study leads
+to absorption $K$ factors in the range of those predicted by previous
+theoretical studies on semi-inclusive processes.",1804.03266v3
+2018-04-12,Controlling breath figure patterns on PDMS by concentration variation of ethanol-methanol binary vapors,"In this paper, the self-assembly of condensed droplets on smooth and
+constrained surfaces under saturated vapor atmosphere of ethanol and methanol
+binary system is reported. Hexagonally ordered array of pores are obtained on
+smooth surfaces with saturated vapors of binary liquids without the assistance
+of any additives. The results show that the addition of small amount of ethanol
+to methanol plays a role very similar to that of surface active agents in
+inducing the formation of regular droplet array. The effect of constraints on
+self-assembled droplet pattern such as movement of contact line and depinning
+of contact line is also investigated. It is observed that the pore size, pore
+shape, pore depth and ring diameter are influenced by the atmosphere of binary
+vapors in addition to the commonly held attribution to the surface tension of
+the solvent. Contact angle studies of the patterned substrates showed
+hydrophobicity with very high adhesiveness to water and Wenzel's state of
+wetting.",1804.04392v1
+2018-04-18,Duality between unprovability and provability in forward proof-search for Intuitionistic Propositional Logic,"The inverse method is a saturation based theorem proving technique; it relies
+on a forward proof-search strategy and can be applied to cut-free calculi
+enjoying the subformula property. Here we apply this method to derive the
+unprovability of a goal formula G in Intuitionistic Propositional Logic. To
+this aim we design a forward calculus FRJ(G) for Intuitionistic unprovability
+which is prone to constructively ascertain the unprovability of a formula G by
+providing a concise countermodel for it; in particular we prove that the
+generated countermodels have minimal height. Moreover, we clarify the role of
+the saturated database obtained as result of a failed proof-search in FRJ(G) by
+showing how to extract from such a database a derivation witnessing the
+Intuitionistic validity of the goal.",1804.06689v1
+2018-05-01,Nonlinear Saturation of Kinetic Ballooning Modes by Zonal fields in Toroidal Plasmas,"Kinetic ballooning modes (KBM) are widely believed to play a critical role in
+disruptive dynamics as well as turbulent transport in tokamaks. While the
+nonlinear evolution of ballooning modes has been proposed as a mechanism for
+detonation in tokamak plasmas, the role of kinetic effects in such nonlinear
+dynamics remains largely unexplored. In this work global gyrokinetic simulation
+results of KBM nonlinear behavior are presented. Instead of the finite-time
+singularity predicted by ideal MHD theory, the kinetic instability is shown to
+develop into an intermediate nonlinear regime of exponential growth, followed
+by a nonlinear saturation regulated by spontaneously generated zonal fields. In
+the intermediate nonlinear regime, rapid growth of localized current sheet is
+observed.",1805.00402v1
+2018-05-04,Homodyne-detector-blinding attack in continuous-variable quantum key distribution,"We propose an efficient strategy to attack a continuous-variable quantum key
+distribution (CV-QKD) system, that we call homodyne detector blinding. This
+attack strategy takes advantage of a generic vulnerability of homodyne
+receivers: a bright light pulse sent on the signal port can lead to a
+saturation of the detector electronics. While detector saturation has already
+been proposed to attack CV-QKD, the attack we study in this paper has the
+additional advantage of not requiring an eavesdropper to be phase locked with
+the homodyne receiver. We show that under certain conditions, an attacker can
+use a simple laser, incoherent with the homodyne receiver, to generate bright
+pulses and bias the excess noise to arbitrary small values, fully comprising
+CV-QKD security. These results highlight the feasibility and the impact of the
+detector blinding attack. We finally discuss how to design countermeasures in
+order to protect against this attack.",1805.01620v2
+2018-05-12,Quark mean-field model for nuclear matter with or without bag,"We propose the new quark mean-field bag (QMFB) model by incorporating the bag
+confinement mechanism in the original quark mean-field model. Nuclear matter
+and neutron star properties are studied with the QMFB model. For the study of
+the bag effect, we newly fit 12 parameter sets by reproducing the empirical
+saturation properties of nuclear matter. Quark confinement is found to be
+mainly demonstrated by the bag after it is included in the model, instead of
+the confining potential. For nuclear matter, the bag decreases the binding
+energy and increases the symmetry energy. For neutron star, the bag affects
+significantly the radius $R$ of a $1.4M_\odot$ star, with the maximum mass only
+slightly modified. The bag also has a large suppression effect on the
+well-accepted $R$ vs $L$ dependence, with $L$ the symmetry energy slope at the
+saturation density.",1805.04678v2
+2018-05-15,Forward di-hadron back-to-back correlations in $\boldsymbol{pA}$ collisions from rcBK evolution,"We study the disappearance of the away-side peak of the di-hadron correlation
+function in p+A vs p+p collisions at forward rapidities, when the scaterring
+process presents a manifest dilute-dense asymmetry. We improve the
+state-of-the-art description of this phenomenon in the framework of the Color
+Glass Condensate (CGC), for hadrons produced nearly back-to-back. In that case,
+the gluon content of the saturated nuclear target can be described with
+transverse-momentum-dependent gluon distributions, whose small-$x$ evolution we
+calculate numerically by solving the Balitsky-Kovchegov equation with running
+coupling corrections. We first show that our formalism provides a good
+description of the disappearance of the away-side azimuthal correlations in
+d+Au collisions observed at BNL Relativistic Heavy Ion Collider (RHIC)
+energies. Then, we predict the away-side peak of upcoming p+Au data at
+$~\sqrt[]{s}=200$ GeV to be suppressed by about a factor 2 with respect to p+p
+collisions, and we propose to study the rapidity dependence of that suppression
+as a complementary strong evidence of gluon saturation in experimental data.",1805.05711v1
+2018-05-15,A high dynamic range optical detector for measuring single photons and bright light,"Detecting light is fundamental to all optical experiments and applications.
+At the single photon level, the quantised nature of light requires specialised
+detectors, which typically saturate for more than one photon, rendering the
+measurement of bright light impossible. Saturation can be partially overcome by
+multiplexing single-photon-sensitive detectors, enabling measurement up to tens
+of photons. However, current approaches are still far from bridging the gap to
+bright light levels. Here, we report on a massively-multiplexed single-photon
+detector, which exhibits a dynamic range of 123 dB, from optical energies as
+low as $\mathbf{10^{-7}}$ photons per pulse to $\mathbf{\sim2.5\times10^{5}}$
+photons per pulse. This allows us to calibrate a single photon detector
+directly to a power meter. The use of a single-photon sensitive detector
+further allows us to characterise the nonclassical features of a variety of
+quantum states. This device will find application where high dynamic range and
+single-photon sensitivity are required.",1805.05881v2
+2018-05-15,Expanding cosmological civilizations on the back of an envelope,"We present a simplified description of expansionistic life in the standard
+relativistic cosmology. The resulting model is exactly integrable, yielding a
+simple set of predictive formulas. This allows one to quickly propose new
+scenarios for the life appearance rate and the dominant expansion speed and
+evaluate the observable consequences. These include the expected number and
+angular size of visible expanding domains, the total eclipsed fraction of the
+sky, and the life-saturated fraction of the universe. We also propose a simple
+anthropic bound on observable quantities, as a function of the dominant
+expansion velocity alone. The goal is to create a simple and intuition-building
+tool for use in the context of cosmology, extragalactic SETI, and futures
+studies. We discuss the general predictions of this framework, including
+conditions giving rise to an ""extragalactic Fermi paradox,"" in which zero
+civilizations are visible beyond the Milky Way. This can occur even if a
+substantial fraction of the universe is already saturated with ambitious life.",1805.06329v1
+2018-05-17,Saturated configuration interaction calculations for five-valent Ta and Db,"Accurate atomic structure calculations of complicated atoms with 4 or more
+valence electrons begin to push the memory and time limits of supercomputers.
+This paper presents a robust method of decreasing the size of \textit{ab
+initio} configuration interaction and many-body perturbation theory
+calculations without undermining the accuracy of the resulting atomic spectra.
+Our method makes it possible to saturate the CI matrix in atoms with many
+valence electrons. We test our method on the five-valence-electron atom
+tantalum and verify the convergence of the calculated energies. We then apply
+the method to calculate spectra and isotope shifts of tantalum's superheavy
+analogue dubnium. Isotope-shift calculations can be used to predict the spectra
+of superheavy isotopes which may be produced in astrophysical phenomena.",1805.06615v1
+2018-05-24,An Accurate Data Cleaning Procedure for Electron Cyclotron Emission Imaging on EAST Tokamak Based on Methodology of Machine Learning,"A new data cleaning procedure for electron cyclotron emission imaging (ECEI)
+of EAST tokamak is constructed. Machine learning techniques, including SVM and
+Decision tree, are applied to identifying saturated, zero, and weak signals of
+ECEI raw data, which not only reduces the effort of researchers for data
+analysis, but also improves the accuracy of data preprocessing. To enhance the
+reliability of the procedure, proper training sets are sampled based on massive
+raw data from the experiments of ECEI on EAST tokamak. Window size of temporal
+signal, kernel function, and other model parameters are obtained after model
+training. Consequently, the recognition rates of saturated, zero, and weak
+signals in raw data are 99.4%, 99.86%, and 99.9%, respectively, which proves
+the accuracy of this procedure.",1805.09540v1
+2018-05-28,The Nuclear Symmetry Energy at Sub-saturation Densities,"The density dependence of the nuclear symmetry energy governs important
+aspects of very neutron rich systems such as heavy nuclei and their collisions,
+neutron stars and their mergers. Many analyses of experimental data have
+generated constraints on the symmetry energy and its first derivative at
+saturation density, rho_0 ~ 2.7xE14 g/cm3.
+  We show that each analysis does not accurately constrain the symmetry energy
+at rho_0, but rather at a lower density, rho_s, that is most sensitively probed
+by that analysis. Using published constraints on the symmetry energy and its
+first derivative at rho_0, we constrain the symmetry energy within a density
+range of 0.25rho_0 to 0.75rho_0 that is relevant to the inner crusts of neutron
+stars and to the neutrino-sphere of core-collapse supernovae. With appropriate
+data, the symmetry energy can be similarly constrained over a wider density
+range.",1805.10757v1
+2018-05-29,Entangling power of time-evolution operators in integrable and nonintegrable many-body systems,"The entangling power and operator entanglement entropy are state independent
+measures of entanglement. Their growth and saturation is examined in the
+time-evolution operator of quantum many-body systems that can range from the
+integrable to the fully chaotic. An analytically solvable integrable model of
+the kicked transverse field Ising chain is shown to have ballistic growth of
+operator von Neumann entanglement entropy and exponentially fast saturation of
+the linear entropy with time. Surprisingly a fully chaotic model with
+longitudinal fields turned on shares the same growth phase, and is consistent
+with a random matrix model that is also exactly solvable for the linear entropy
+entanglements. However an examination of the entangling power shows that its
+largest value is significantly less than the nearly maximal value attained by
+the nonintegrable one. The importance of long-range spectral correlations, and
+not just the nearest neighbor spacing, is pointed out in determing the growth
+of entanglement in nonintegrable systems. Finally an interesting case that
+displays some features peculiar to both integrable and nonintegrable systems is
+briefly discussed.",1805.11632v1
+2018-06-11,Mechanism of slow equilibration of isolated quantum systems,"We discuss the approach toward equilibrium of an isolated quantum system. For
+a wide class of systems we argue that the time-averaged expectation value of a
+local operator in any initial state is bounded by the so-called deviation
+function, which characterizes maximal deviation from the equilibrium for all
+states with a given value of energy fluctuations. We provide numerical evidence
+that the bound is approximately saturated by the initial configurations with
+spatial inhomogeneities at macroscopic level. In this way the deviation
+function establishes an explicit connection between the macroscopically
+observed timescales associated with transport and properties of microscopic
+matrix elements. The form of the deviation function indicates that among the
+slowest states which saturate the bound there are also those with arbitrarily
+long equilibration times.",1806.04187v1
+2018-06-15,On the exact minimization of saturated loss functions for robust regression and subspace estimation,"This paper deals with robust regression and subspace estimation and more
+precisely with the problem of minimizing a saturated loss function. In
+particular, we focus on computational complexity issues and show that an exact
+algorithm with polynomial time-complexity with respect to the number of data
+can be devised for robust regression and subspace estimation. This result is
+obtained by adopting a classification point of view and relating the problems
+to the search for a linear model that can approximate the maximal number of
+points with a given error. Approximate variants of the algorithms based on
+ramdom sampling are also discussed and experiments show that it offers an
+accuracy gain over the traditional RANSAC for a similar algorithmic simplicity.",1806.05833v2
+2018-06-14,Coherent and incoherent production of vector mesons in ultraperipheral collisions of Xenon-ions within the QCD parton saturation approach,"In this paper we analyse the exclusive vector meson photoproduction in the
+recent run using Xenon-ions at energy of 5.44 TeV performed by the Large Hadron
+Collider. We focus on the ultraperipheral collisions and provide theoretical
+predictions for coherent and incoherent cross sections within the color dipole
+approach and gluon saturation framework. The rapidity distribution is
+investigated in both cases and comparison to other approaches available at
+literature is done. We show that the expected yields are enough to perform
+reliable cross section measurements for light mesons as $\rho^0$ and $\phi$.",1806.06701v1
+2018-06-18,Confronting impact parameter dependent JIMWLK evolution with HERA data,"The small-$x$ evolution of protons is determined from numerical solutions of
+the JIMWLK equations, starting from an initial condition at moderate $x$ for a
+finite size proton. The resulting dipole amplitude is used to calculate the
+total reduced cross section $\sigma_r$ and charm reduced cross section
+$\sigma_{rc}$, as well as diffractive vector meson production. We compare
+results to experimental data from HERA and discuss fundamental problems arising
+from the regime sensitive to non-perturbative physics. We emphasize that
+information on the gluonic content of the proton, gluon spatial distributions
+and correlations over wide ranges in $x$, which can in principle be constrained
+by our study, are essential ingredients for describing the initial state in
+proton-proton and proton-ion collisions. Future electron nucleus collisions at
+an electron-ion collider will provide important additional insight for heavier
+nuclei. We further demonstrate that it is not possible to probe gluon
+saturation in electron-proton collision at HERA energies and that
+electron-heavy ion collisions will be essential to access the saturation
+regime.",1806.06783v1
+2018-06-20,Three-dimensional particle-in-cell modeling of parametric instabilities near the quarter-critical density in plasmas,"The nonlinear regime of laser-plasma interaction including both
+two-plasmon--decay (TPD) and stimulated Raman scattering (SRS) instabilities
+has been studied in three-dimensional (3-D) particle-in-cell simulations with
+parameters relevant to the inertial confinement fusion (ICF) experiments. SRS
+and TPD develop in the same region in plasmas, and the generation of fast
+electrons can be described accurately with only the full model including both
+SRS and TPD. The growth of instabilities in the linear stage is found to be in
+good agreement with analytical theories. In the saturation stage the enhanced
+low-frequency density perturbations driven by the daughter waves of the SRS
+sidescattering can saturate the TPD and consequently inhibit the fast-electron
+generation. The fast-electron flux in 3-D modeling is up to an order of
+magnitude smaller than previously reported in 2-D TPD simulations, bringing it
+close to the results of ICF experiments.",1806.07510v2
+2018-07-04,Quantum correlations in two-level atomic system over Herring-Flicker coupling,"We study the thermal quantum correlations in tripartite atomic system under
+the existence of Herring-Flicker (HF) coupling among the atoms. We explore two
+topologically distinct configurations of three coupled two-level atoms, viz.,
+loop and line, differing in their coupling pattern. Further, the systems having
+asymmetric arrangement of atoms are quantum mechanically correlated more
+strongly than systems having symmetric arrangements. The variable nature of HF
+coupling leads to the increase of both concurrence and discord from zero to a
+saturation value from where they decrease to zero as a function of inter-atomic
+distance. Further separation leads to both the quantities attaining another
+saturation value. This controlled correlations play an important role in the
+design of quantum data buses that can transfer quantum states to establish
+quantum communication. The systems coupled via HF coupling will be efficient
+for this task as they are maximally entangled in parametrically controlled
+manner. Thus, these systems will be propitious for various quantum protocols
+such as secure communication, quantum cryptography, quantum key distribution
+etc.",1807.01805v4
+2018-07-06,Latest predictions from the EbyE NLO EKRT model,"We present the latest results from the NLO pQCD + saturation + viscous
+hydrodynamics (EbyE NLO EKRT) model. The parameters in the EKRT saturation
+model are fixed by the charged hadron multiplicity in the 0-5 \% 2.76 TeV Pb+Pb
+collisions. The $\sqrt{s}$, $A$ and centrality dependence of the initial
+particle production follows then from the QCD dynamics of the model. This
+allows us to predict the $\sqrt{s}$ and $A$ dependence of the particle
+production. We show that our results are in an excellent agreement with the
+low-$p_T$ data from 2.76 TeV and 5.02 TeV Pb+Pb collisions at the LHC as well
+as with the data from the 200 GeV Au+Au collisions at RHIC. In particular, we
+study the centrality dependences of hadronic multiplicities, flow coefficients,
+and various flow correlations. Furthermore, the nuclear mass number dependence
+of the initial particle production and hydrodynamic evolution can be tested in
+the 5.44 TeV Xe+Xe collisions at the LHC. To this end, we show our predictions
+for charged particle multiplicities, and in particular, show how the
+deformations of the Xe nuclei reflect into the flow coefficients.",1807.02378v1
+2018-07-08,CGC/saturation approach: re-visiting the problem of odd harmonics in angular correlations,"In this paper we demonstrate that the selection of events with different
+multiplicities of produced particles, leads to the violation of the azimuthal
+angular symmetry, $\phi \to \pi - \phi$. We find for LHC and lower energies,
+that this violation can be so large for the events with multiplicities $n \geq
+2 \bar{n}$, where $\bar{n}$ is the mean multiplicity, that it leads to almostno
+suppression of $v_n$, with odd $n$. However, this can only occur if the typical
+size of the dipole in DIS with a nuclear target is small, or $Q^2 \,>\,Q^2_s\Lb
+A, Y_{\rm min},b\Rb$, where $Q_s$ is the saturation momentum of the nucleus at
+$Y = Y_{\rm min}$. In the case of large sizes of dipoles, when $Q^2
+\,<\,Q^2_s\Lb A, Y_{\rm min},b\Rb$, we show that $v_n =0$ for odd $n$.
+Hadron-nucleus scattering is discussed.",1807.02783v1
+2018-07-10,Anode current saturation of ALD-coated Planacon MCP-PMTs,"We have measured and compared the characteristics of ALD-coated Planacon
+MCP-PMTs (XP85112/A1-Q-L) with their non-ALD counterparts (XP85012/A1-Q). While
+the later show excellent performance, the ALD-coated sensors have surprisingly
+low current saturation levels (~two orders of magnitude lower than expected)
+and extremely high gain recovery time (more than 7 orders of magnitude higher
+than expected). We suspect that these problems might be caused by the
+unexpected side-effects of the ALD process. To make a definite conclusion, more
+samples need to be tested, preferably from different production runs. If our
+observation were confirmed, it would mean a serious technological setback for
+ALD-coated MCP-PMTs.",1807.03804v2
+2018-07-13,Effects of $^4$He film on quartz tuning forks in $^3$He at ultra-low temperatures,"In pure superfluid $^3$He-B at ultra-low temperatures, quartz tuning fork
+oscillator response is expected to saturate when the dissipation caused by the
+superfluid medium becomes substantially smaller than the internal dissipation
+of the oscillator. However, even with small amount of $^4$He covering the
+surfaces, we have observed saturation already at significantly higher
+temperatures than anticipated, where we have other indicators to prove that the
+$^3$He liquid is still cooling. We found that this anomalous behavior has a
+rather strong pressure dependence, and it practically disappears above the
+crystallization pressure of $^4$He. We also observed a maximum in the fork
+resonance frequency at temperatures where the transition in quasiparticle flow
+from the hydrodynamic to the ballistic regime is expected. We suggest that such
+anomalous features derive from the superfluid $^4$He film on the oscillator
+surface.",1807.05084v2
+2018-07-17,Nuclear and neutron matter equations of state from high-quality potentials up to fifth order of the chiral expansion,"We present predictions for the equation of state of symmetric nuclear and
+pure neutron matter based on recent high-quality nucleon-nucleon potentials
+from leading order to fifth order in the chiral expansion. We include as well
+the next-to-next-to-leading order (N2LO) chiral three-nucleon force whose
+low-energy constants cD and cE are fitted to the binding energies of 3H and 3He
+as well as the \b{eta}-decay lifetime of 3H. The ground state energy per
+particle is computed in the particle- particle ladder approximation up to a few
+times saturation density. Due to the soft character of the interactions,
+uncertainties due to the convergence in many-body perturbation theory are
+small. We find that nuclear matter saturation is reproduced quantitatively at
+N3LO and N4LO, and therefore we encourage the application of these interactions
+in finite nuclei, where the description of ground- state energies and charge
+radii of medium-mass nuclei may be improved.",1807.06640v1
+2018-07-18,Linearity of Saturation for Berge Hypergraphs,"For a graph $F$, we say a hypergraph $H$ is Berge-$F$ if it can be obtained
+from $F$ be replacing each edge of $F$ with a hyperedge containing it. We say a
+hypergraph is Berge-$F$-saturated if it does not contain a Berge-$F$, but
+adding any hyperedge creates a copy of Berge-$F$. The $k$-uniform saturation
+number of Berge-$F$, $\mathrm{sat}_k(n,\text{Berge-}F)$ is the fewest number of
+edges in a Berge-$F$-saturated $k$-uniform hypergraph on $n$ vertices. We show
+that $\mathrm{sat}_k(n,\text{Berge-}F) = O(n)$ for all graphs $F$ and
+uniformities $3\leq k\leq 5$, partially answering a conjecture of English,
+Gordon, Graber, Methuku, and Sullivan. We also extend this conjecture to Berge
+copies of hypergraphs.",1807.06947v1
+2018-07-26,A Transition of Saturable and Reverse Saturable Absorption between Monolayer and Bilayer/Multilayer of TMDCs,"The nonlinear absorption of two-dimensional molybdenum disulfide was analyzed
+using the Z-scan technique. Sample size corresponding to a number of layer
+determines the band gap in the materials which play the key role for
+nonlinearity. Exciton dipole transition from ground state to excited state for
+monolayer and bilayer/multilayer is determined by the excitation source, ESA
+and GSA values. If the band gap is wider than the excitation source, two-photon
+excitation process is dominant which requires the larger ESA than GSA. For
+narrower bandgap, one-photon excitation is favorable because of the larger GSA
+than ESA. In addition, defects, the temperature may alter the band gap.
+Therefore, the transition from RSA to SA and vice versa is determined by the
+number of layers in materials, temperature, and defects for a given excitation
+energy.",1807.09945v2
+2018-08-09,Optical bistability and nonlinear dynamics by saturation of cold Yb atoms in a cavity,"We observed optical bistability as well as oscillations in the upper bistable
+branch when cold ytterbium atoms are dispersively coupled to a high finesse
+optical cavity. Comparable previous observations were explained by atomic
+density oscillations in case of a Bose-Einstein-Condensate or optical pumping
+in case of a cold cloud of cesium. Both explanations do not apply in our case
+of thermal atoms with only a single ground state. We propose a simple two-level
+model including saturation to describe our experimental results. This paper
+introduces the experimental setup, derives the mentioned model and compares it
+to our experimental data. Good quantitative agreement supports our model.",1808.03132v1
+2018-08-17,PT-symmetric potentials with imaginary asymptotic saturation,"We point out that PT-symmetric potentials $V_{PT}(x)$ having imaginary
+asymptotic saturation: $V_{PT}(x=\pm \infty) =\pm i V_1, V_1 \in \Re$ are
+devoid of scattering states and spectral singularity. We show the existence of
+real (positive and negative) discrete spectrum both with and without complex
+conjugate pair(s) of eigenvalues (CCPEs). If the states are arranged in the
+ascending order or real part of discrete eigenvalues, the initial states have
+few nodes but latter ones oscillate fast. Both real and imaginary parts of
+$\psi(x)$ vanish asymptotically, $|\psi(x)|$ for the CCPEs are asymmetric and
+for real energies these are symmetric about origin. For CCPEs $E_{\pm}$ the
+eigenstates $\psi_{\pm}$ follow an interesting property that $|\psi_+(x)|= N
+|\psi_-(-x)|, N \in \Re^+$. We remark that, the fast oscillating real discrete
+energy states discussed are likely to be confused with: reflectionless states,
+one dimensional version of von Neumann states of Hermitian and spectral
+singularity state of complex PT-symmetric potentials.",1808.05828v2
+2018-08-18,"Surface permeability, capillary transport and the Laplace-Beltrami problem","We have established previously, in a lead-in study, that the spreading of
+liquids in particulate porous media at low saturation levels,
+characteristically less than 10% of the void space, has very distinctive
+features in comparison to that at higher saturation levels. In particular, we
+have found that the dispersion process can be accurately described by a special
+class of partial differential equations, the super-fast non-linear diffusion
+equation. The results of mathematical modelling have demonstrated very good
+agreement with experimental observations. However, any enhancement of the
+accuracy and predictive power of the model, keeping in mind practical
+applications, requires the knowledge of the effective surface permeability of
+the constituent particles, which defines the global, macroscopic permeability
+of the particulate media. In the paper, we demonstrate how this quantity can be
+determined through the solution of the Laplace-Beltrami Dirichlet problem, we
+study this using the well-developed surface finite element method.",1808.06077v1
+2018-08-20,Influence of fluids on $V_\mathrm{P}/V_\mathrm{S}$ ratio: Increase or decrease?,"The evolution of $V_\mathrm{P}/V_\mathrm{S}$ with increasing fluid-saturated
+porosity is computed for isotropic rocks containing spheroidal pores.
+$V_\mathrm{P}/V_\mathrm{S}$ is shown to either decrease or increase with
+increasing porosity, depending on the aspect ratio $\alpha$ of the pores, fluid
+to solid bulk modulus ratio $\zeta$, and initial Poisson's ratio $\nu_0$ of the
+solid. A critical initial Poisson's ratio $\nu_\mathrm{0,crit}$ is computed,
+separating cases where $V_\mathrm{P}/V_\mathrm{S}$ increases (if
+$\nu_0<\nu_\mathrm{0,crit}$) or \emph{decreases} (if
+$\nu_0>\nu_\mathrm{0,crit}$) with increasing porosity. For thin cracks and
+highly compressible fluids, $\nu_\mathrm{0,crit}$ is approximated by
+$0.157\,\zeta/\alpha$, whereas for spherical pores $\nu_\mathrm{0,crit}$ is
+given by $0.2 + 0.8\zeta$. If $\nu_0$ is close to $\nu_\mathrm{0,crit}$, the
+evolution of $V_\mathrm{P}/V_\mathrm{S}$ with increasing fluid-saturated
+porosity is near neutral and depends on subtle changes in pore shape and fluid
+properties. This regime is found to be relevant to partially dehydrated
+serpentinites in subduction zone conditions (porosity of aspect ratio near 0.1
+and $\zeta$ in the range 0.01--0.1), and makes detection of these rocks and
+possibly elevated fluid pressures difficult from $V_\mathrm{P}/V_\mathrm{S}$
+only.",1808.06387v2
+2018-08-22,PT-symmetry breaking in multilayers with resonant loss and gain locks light propagation direction,"Using the Maxwell-Bloch equations for resonantly absorbing and amplifying
+media, we study the temporal dynamics of light propagation through the
+PT-symmetric structures with alternating loss and gain layers. This approach
+allows us to precisely describe the response of the structure near the
+exceptional points of PT-symmetry breaking phase transition and, in particular,
+take into account the nonlinear effect of loss and gain saturation in the
+PT-symmetry broken state. We reveal that in this latter state the multilayer
+system possesses a lasing-like behavior releasing the pumped energy in the form
+of powerful pulses. We predict locking of pulse direction due to the
+PT-symmetry breaking, as well as saturation-induced irreversibility of phase
+transition and nonreciprocal transmission.",1808.07477v1
+2018-08-18,A lattice Boltzmann model for two-phase flow in porous media,"In this paper, a lattice Boltzmann (LB) model with double distribution
+functions is proposed for two-phase flow in porous media where one distribution
+function is used for pressure governed by the Poisson equation, and the other
+is applied for saturation evolution described by the convection-diffusion
+equation with a source term. We first performed a Chapman-Enskog analysis, and
+show that the macroscopic nonlinear equations for pressure and saturation can
+be recovered correctly from present LB model. Then in the framework of LB
+method, we develop a local scheme for pressure gradient or equivalently
+velocity, which may be more efficient than the nonlocal second-order
+finite-difference schemes. We also perform some numerical simulations, and the
+results show that the developed LB model and local scheme for velocity are
+accurate and also have a second-order convergence rate in space. Finally,
+compared to the available pore-scale LB models for two-phase flow in porous
+media, the present LB model has more potential in the study of the large-scale
+problems.",1808.07554v1
+2018-08-23,Microscopic theory of capillary pressure hysteresis based on pore-space accessivity and radius-resolved saturation,"Continuum models of porous media use macroscopic parameters and state
+variables to capture essential features of pore-scale physics. We propose a
+macroscopic property ""accessivity"" ($\alpha$) to characterize the network
+connectivity of different sized pores in a porous medium, and macroscopic state
+descriptors ""radius-resolved saturations"" ($\psi_w(F),\psi_n(F)$) to
+characterize the distribution of fluid phases within. Small accessivity
+($\alpha\to0$) implies serial connections between different sized pores, while
+large accessivity ($\alpha\to1$) corresponds to more parallel arrangements, as
+the classical capillary bundle model implicitly assumes. Based on these
+concepts, we develop a statistical theory for quasistatic immiscible
+drainage-imbibition in arbitrary cycles, and arrive at simple algebraic
+formulae for updating $\psi_n(F)$ that naturally capture capillary pressure
+hysteresis, with $\alpha$ controlling the amount of hysteresis. These concepts
+may be used to interpret hysteretic data, upscale pore-scale observations, and
+formulate new constitutive laws by providing a simple conceptual framework for
+quantifying connectivity effects, and may have broader utility in continuum
+modeling of transport, reactions, and phase transformations in porous media.",1808.09804v2
+2018-09-10,Density decay and growth of correlations in the Game of Life,"We study the Game of Life as a statistical system on an $L\times L$ square
+lattice with periodic boundary conditions. Starting from a random initial
+configuration of density $\rho_{\rm in}=0.3$ we investigate the relaxation of
+the density as well as the growth with time of spatial correlations. The
+asymptotic density relaxation is exponential with a characteristic time
+$\tau_L$ whose system size dependence follows a power law $\tau_L\propto L^z$
+with $z=1.66\pm 0.05$ before saturating at large system sizes to a constant
+$\tau_\infty$. The correlation growth is characterized by a time dependent
+correlation length $\xi_t$ that follows a power law $\xi_t\propto
+t^{1/z^\prime}$ with $z^\prime$ close to $z$ before saturating at large times
+to a constant $\xi_\infty$. We discuss the difficulty of determining the
+correlation length $\xi_\infty$ in the final ""quiescent"" state of the system.
+The decay time $t_{\rm q}$ towards the quiescent state is a random variable, we
+present simulational evidence as well as a heuristic argument indicating that
+for large $L$ its distribution peaks at a value $t_{\rm q}^*(L) \simeq
+2\tau_\infty\log L$.",1809.03266v2
+2018-09-18,A Simple Approximation for a Hard Routing Problem,"We consider a routing problem which plays an important role in several
+applications, primarily in communication network planning and VLSI layout
+design. The original underlying graph algorithmic task is called Disjoint Paths
+problem. In most applications, one can encounter its capacitated
+generalization, which is known as the Unsplitting Flow problem. These
+algorithmic tasks are very hard in general, but various efficient
+(polynomial-time) approximate solutions are known. Nevertheless, the
+approximations tend to be rather complicated, often rendering them impractical
+in large, complex networks. Our goal is to present a solution that provides a
+simple, efficient algorithm for the unsplittable flow problem in large directed
+graphs. The simplicity is achieved by sacrificing a small part of the solution
+space. This also represents a novel paradigm of approximation: rather than
+giving up finding an exact solution, we restrict the solution space to its most
+important subset and exclude those that are marginal in some sense. Then we
+find the exact optimum efficiently within the subset. Specifically, the
+sacrificed parts (i.e., the marginal instances) only contain scenarios where
+some edges are very close to saturation. Therefore, the excluded part is not
+significant, since the excluded almost saturated solutions are typically
+undesired in practical applications, anyway.",1809.06562v1
+2018-09-28,Standing lattice solitons in the discrete NLS equation with saturation,"We consider standing lattice solitons for discrete nonlinear Schrodinger
+equation with saturation (NLSS), where so-called transparent points were
+recently discovered. These transparent points are the values of the governing
+parameter (e.g., the lattice spacing) for which the Peierls-Nabarro barrier
+vanishes. In order to explain the existence of transparent points, we study a
+solitary wave solution in the continuous NLSS and analyse the singularities of
+its analytic continuation in the complex plane. The existence of a quadruplet
+of logarithmic singularities nearest to the real axis is proven and applied to
+two settings: (i) the fourth-order differential equation arising as the
+next-order continuum approximation of the discrete NLSS and (ii) the
+advance-delay version of the discrete NLSS.",1809.10828v1
+2018-10-01,Few $T$ copies in $H$-saturated graphs,"A graph is $F$-saturated if it is $F$-free but the addition of any edge
+creates a copy of $F$. In this paper we study the quantity $\mathrm{sat}(n, H,
+F)$ which denotes the minimum number of copies of $H$ that an $F$-saturated
+graph on $n$ vertices may contain. This parameter is a natural saturation
+analogue of Alon and Shikhelman's generalized Tur\'an problem, and letting $H =
+K_2$ recovers the well-studied saturation function. We provide a first
+investigation into this general function focusing on the cases where the host
+graph is either $K_s$ or $C_k$-saturated. Some representative interesting
+behavior is:
+  (a) For any natural number $m$, there are graphs $H$ and $F$ such that
+$\mathrm{sat}(n, H, F) = \Theta(n^m)$.
+  (b) For many pairs $k$ and $l$, we show $\mathrm{sat}(n, C_l, C_k) = 0$. In
+particular, we prove that there exists a triangle-free $C_k$-saturated graph on
+$n$ vertices for any $k > 4$ and large enough $n$.
+  (c) $\mathrm{sat}(n, K_3, K_4) = n-2$, $\mathrm{sat}(n, C_4, K_4) \sim
+\frac{n^2}{2}$, and $\mathrm{sat}(n, C_6, K_5) \sim n^3$.
+  We discuss several intriguing problems which remain unsolved.",1810.00939v2
+2018-10-01,Exact stationary solutions of the Kolmogorov-Feller equation in a bounded domain,"We present the first detailed analysis of the statistical properties of jump
+processes bounded by a saturation function and driven by Poisson white noise,
+being a random sequence of delta pulses. The Kolmogorov-Feller equation for the
+probability density function (PDF) of such processes is derived and its
+stationary solutions are found analytically in the case of the symmetric
+uniform distribution of pulse sizes. Surprisingly, these solutions can exhibit
+very complex behavior arising from both the boundedness of pulses and
+processes. We show that all features of the stationary PDF (number of branches,
+their form, extreme values probability, etc.) are completely determined by the
+ratio of the saturation function width to the half-width of the pulse-size
+distribution. We verify all theoretical results by direct numerical
+simulations.",1810.00992v2
+2018-10-13,Confinement and crowding control the morphology and dynamics of a model bacterial chromosome,"Motivated by recent experiments probing shape, size and dynamics of bacterial
+chromosomes in growing cells, we consider a polymer model consisting of a
+circular backbone to which side-loops are attached, confined to a cylindrical
+cell. Such a model chromosome spontaneously adopts a helical shape, which is
+further compacted by molecular crowders to occupy a nucleoid-like subvolume of
+the cell. With increasing cell length, the longitudinal size of the chromosome
+increases in a non-linear fashion to finally saturate, its morphology gradually
+opening up while displaying a changing number of helical turns. For shorter
+cells, the chromosome extension varies non-monotonically with cell size, which
+we show is associated with a radial to longitudinal spatial reordering of the
+crowders. Confinement and crowders constrain chain dynamics leading to
+anomalous diffusion. While the scaling exponent for the mean squared
+displacement of center of mass grows and saturates with cell length, that of
+individual loci displays broad distribution with a sharp maximum.",1810.05869v1
+2018-09-04,Determination of water permeability for cementitious materials with minimized batch effect,"Values of water permeability for cementitious materials reported in the
+literature show a large scatter. This is partially attributed to the fact that
+materials used in different studies are different. To eliminate the effects of
+cements, specimen preparation, curing conditions and other batch effects, this
+study employs a long cylindrical cement paste to prepare all specimens for a
+variety of permeability determination methods, such as beam bending,
+sorptivity, Katz Thompson and Kozeny Carman equations. Permeabilities
+determined by these methods are then used in a moisture transport model.
+Compared with the measured mass loss curves, we found that permeability
+determined by the beam bending method provides much closer results to the
+measured ones than other methods. The difference results from that the
+saturated specimen is used in the beam bending method while specimens in other
+methods are dried (or rewetted). As already shown in the literature, the
+microstructure of the dried or rewetted specimens is altered and different to
+the original microstructure of the water saturated specimens.",1810.06463v1
+2018-10-17,A (Bounded) Bestiary of Feynman Integral Calabi-Yau Geometries,"We define the rigidity of a Feynman integral to be the smallest dimension
+over which it is non-polylogarithmic. We argue that massless Feynman integrals
+in four dimensions have a rigidity bounded by 2(L-1) at L loops, and we show
+that this bound may be saturated for integrals that we call marginal: those
+with (L+1)D/2 propagators in (even) D dimensions. We show that marginal Feynman
+integrals in D dimensions generically involve Calabi-Yau geometries, and we
+give examples of finite four-dimensional Feynman integrals in massless $\phi^4$
+theory that saturate our predicted bound in rigidity at all loop orders.",1810.07689v2
+2018-10-31,Enhanced Quasi-Maximum Likelihood Decoding of Short LDPC Codes based on Saturation,"In this paper, we propose an enhanced quasi-maximum likelihood (EQML) decoder
+for LDPC codes with short block lengths. After the failure of the conventional
+belief propagation (BP) decoding, the proposed EQML decoder selects unreliable
+variable nodes (VNs) and saturates their associated channel output values to
+generate a list of decoder input sequences. Each decoder input sequence in the
+list is then decoded by the conventional BP decoder to obtain the most likely
+codeword. To improve the accuracy of selecting unreliable VNs, we propose an
+edge-wise selection method based on the sign fluctuation of VNs' extrinsic
+messages. A partial pruning stopping (PPS) rule is also presented to reduce the
+decoding latency. Simulation results show that the proposed EQML decoder
+outperforms the conventional BP decoder and the augmented BP decoder for short
+LDPC codes. It even approaches the performance of ML decoding within 0.3 dB in
+terms of frame error rate. In addition, the proposed PPS rule achieves a lower
+decoding latency compared to the list decoding stopping rule.",1810.13111v2
+2018-11-12,Fully Implicit Multidimensional Hybrid Upwind Scheme for Coupled Flow and Transport,"Robust and accurate fully implicit finite-volume schemes applied to
+Darcy-scale multiphase flow and transport in porous media are highly desirable.
+Recently, a smooth approximation of the saturation-dependent flux coefficients
+based on Implicit Hybrid Upwinding (IHU) has been proposed to improve the
+nonlinear convergence in fully implicit simulations with buoyancy. Here, we
+design a truly multidimensional extension of this approach that retains the
+simplicity and robustness of IHU while reducing the sensitivity of the results
+to the orientation of the computational (Cartesian) grid. This is achieved with
+the introduction of an adaptive, local coupling between the fluxes that takes
+the flow pattern into account. We analyze the mathematical properties of the
+proposed methodology to show that the scheme is monotone in the presence of
+competing viscous and buoyancy forces and yields saturations remaining between
+physical bounds. Finally, we demonstrate the efficiency and accuracy of the
+scheme on challenging two-dimensional two-phase examples with buoyancy, with an
+emphasis on the reduction of the grid orientation effect.",1811.04830v3
+2018-11-22,Revised theoretical limit of subthreshold swing in field-effect transistors,"This letter reports a temperature-dependent limit for the subthreshold swing
+in MOSFETs that deviates from the Boltzmann limit at deep-cryogenic
+temperatures. Below a critical temperature, the derived limit saturates to a
+value that is independent of temperature and proportional to the extent of a
+band tail. Since the saturation is universally observed in different types of
+MOSFETs (regardless of dimension or semiconductor material), the band tail is
+attributed to the finite periodicity of the lattice in a semiconductor volume,
+and to a lesser extent to additional lattice perturbations such as defects or
+disorder.",1811.09146v3
+2018-11-30,Signature of quantum chaos in operator entanglement in 2d CFTs,"We study operator entanglement measures of the unitary evolution operators of
+(1+1)-dimensional conformal field theories (CFTs), aiming to uncover their
+scrambling and chaotic behaviors. In particular, we compute the bi-partite and
+tri-partite mutual information for various configurations of input and output
+subsystems, and as a function of time. We contrast three different CFTs: the
+free fermion theory, compactified free boson theory at various radii, and CFTs
+with holographic dual. We find that the bi-partite mutual information exhibits
+distinct behaviors for these different CFTs, reflecting the different
+information scrambling capabilities of these unitary operators; while a
+quasi-particle picture can describe well the case the free fermion and free
+boson CFTs, it completely fails for the case of holographic CFTs. Similarly,
+the tri-partite mutual information also distinguishes the unitary evolution
+operators of different CFTs. In particular, its late-time behaviors, when the
+output subsystems are semi-infinite, are quite distinct for these theories. We
+speculate that for holographic theories the late-time saturation value of the
+tri-partite mutual information takes the largest possible negative value and
+saturates the lower bound among quantum field theories.",1812.00013v1
+2018-12-10,The $φ^4$ model with the BPS preserving defect,"The $\phi^4$ model is coupled to an impurity in a way that preserves one-half
+of the BPS property. This means that the antikink-impurity bound state is still
+a BPS solution, i.e., a zero-pressure solution saturating the topological
+energy bound. The kink-impurity bound state, on the other hand, does not
+saturate the bound, in general. We found that, although the impurity breaks
+translational invariance, it is, in some sense, restored in the BPS sector
+where the energy of the antikink-impurity solution does not depend on their
+mutual distance. This is reflected in the existence of a generalised
+translational symmetry and a zero mode. We also investigate scattering
+processes. In particular, we compare the antikink-impurity interaction close to
+the BPS regime, which presents a rather smooth, elastic like nature, with other
+scattering processes. However, even in this case, after exciting a sufficiently
+large linear mode on the incoming antikink, we can depart from the close-to-BPS
+regime. This results, for example, in a backward scattering.",1812.04007v2
+2018-12-12,Upper bound of density for packing of congruent hyperballs in hyperbolic $3-$space,"In \cite{Sz17-2} we proved that to each saturated congruent hyperball packing
+exists a decomposition of $3$-dimensional hyperbolic space $\mathbb{H}^3$ into
+truncated tetrahedra. Therefore, in order to get a density upper bound for
+hyperball packings, it is sufficient to determine the density upper bound of
+hyperball packings in truncated simplices. In this paper we prove, using the
+above results and the results of papers \cite{M94} and \cite{Sz14}, that the
+density upper bound of the saturated congruent hyperball (hypersphere) packings
+related to the corresponding truncated tetrahedron cells is realized in a
+regular truncated tetrahedra with density $\approx 0.86338$. Furthermore, we
+prove that the density of locally optimal congruent hyperball arrangement in
+regular truncated tetrahedron is not a monotonically increasing function of the
+height (radius) of corresponding optimal hyperball, contrary to the ball
+(sphere) and horoball (horosphere) packings.",1812.06785v1
+2018-12-31,Microscopic 3D measurement of shiny surfaces based on a multi-frequency phase-shifting scheme,"Microscopic fringe projection profilometry is a powerful 3D measurement
+technique with a theoretical measurement accuracy better than one micron
+provided that the measured targets can be imaged with good fringe visibility.
+However, practically, the 3D shape of the measured surface can hardly be fully
+reconstructed due to the defocus of the dense fringes and complex surface
+reflexivity characteristics, which lead to low fringe quality and intensity
+saturation. To address this problem, we propose to calculate phases of these
+highlighted areas from a subset of the fringe sequence which is not subjected
+to the intensity saturation. By using the proposed multi-frequency
+phase-shifting scheme, the integrity of the 3D surface reconstruction can be
+significantly improved. The ultimate phase maps obtained from unsaturated
+intensities are used to achieve high-accuracy 3D recovering of shiny surfaces
+based on a phase stereo matching method. Experimental results on different
+metal surfaces show that our approach is able to retrieve the complete
+morphology of shiny surfaces with high accuracy and fidelity.",1901.00381v1
+2019-01-08,Constraint to chiral invariant masses of nucleons from GW170817 in an extended parity doublet model,"We construct nuclear matter based on an extended parity doublet model
+including four light nucleons $N(939)$, $N(1440)$, $N(1535)$, and $N(1650)$. We
+exclude some values of the chiral invariant masses by requiring the saturation
+properties of normal nuclear matter; saturation density, binding energy,
+incompressibility, and symmetry energy. We find further constraint to the
+chiral invariant masses from the tidal deformability determined by the
+observation of the gravitational waves from neutron star merger GW170817. Our
+result shows that the chiral invariant masses are larger than about $600\,$MeV.
+We also give some predictions on the symmetry energy and the slope parameters
+in the high density region, which will be measured in future experiments.",1901.02167v2
+2019-01-08,The semi-algebraic geometry of saturated optimal designs for the Bradley-Terry model,"Optimal design theory for nonlinear regression studies local optimality on a
+given design space. We identify designs for the Bradley--Terry paired
+comparison model with small undirected graphs and prove that every saturated
+D-optimal design is represented by a path. We discuss the case of four
+alternatives in detail and derive explicit polynomial inequality descriptions
+for optimality regions in parameter space. Using these regions, for each point
+in parameter space we can prescribe a D-optimal design.",1901.02375v3
+2019-01-09,Recovering saturated images for high dynamic Kernel-Phase analysis Application to the determination of dynamical masses for the system Gl 494AB,"Kernel-phase observables extracted from mid- to high-Strehl images are
+proving to be a powerful tool to probe within a few angular resolution elements
+of point sources. The attainable contrast is however limited by the dynamic
+range of the imaging sensors. The Fourier interpretation of images with pixels
+exposed beyond the saturation has so far been avoided. We show that in cases
+where the image is dominated by the light of a point source, we can use an
+interpolation to reconstruct the otherwise lost pixels with an accuracy
+sufficient to enable the extraction of kernel-phases from the patched image. We
+demonstrate the usability of our method by applying it to archive images of the
+Gl 494AB system, taken with the Hubble Space Telescope in 1997. Using this new
+data point along with other resolved observations and radial velocity
+measurements, we produce improved constraints on the orbital parameters of the
+system, and consequently the masses of its components.",1901.02824v2
+2018-12-30,Performance modelling of access control mechanisms for local and vehicular wireless networks,"Carrier sense multiple access collision avoidance (CSMA/CA) is the basic
+scheme upon which access to the shared medium is regulated in many wireless
+networks. With CSMA/CA a station willing to start a transmission has first to
+find the channel free for a given duration otherwise it will go into
+\emph{backoff}, i.e. refraining for transmitting for a randomly chosen delay.
+Performance analysis of a wireless network employing CSMA/CA regulation is not
+an easy task: except for simple network configuration analytical solution of
+key performance indicators (KPI) cannot be obtained hence one has to resort to
+formal modelling tools. In this paper we present a performance modelling study
+targeting different kind of CSMA/CA based wireless networks, namely: the IEEE
+802.11 Wireless Local Area Networks (WLANs) and the 802.11p Vehicular Ad Hoc
+Networks (VANETs), which extends 802.11 with priorities over packets. The
+modelling framework we introduce allows for considering: i) an arbitrarily
+large number of stations, ii) different traffic conditions
+(saturated/non-saturated), iii) different hypothesis concerning the shared
+channel (ideal/non-ideal). We apply statistical model checking to assess KPIs
+of different network configurations.",1901.04285v1
+2019-01-19,Towards a better understanding of the symmetry energy within neutron stars,"The LIGO-Virgo collaboration ground-breaking detection of the binary
+neutron-star merger event, GW170817, has expanded efforts to understand the
+Equation of State (EoS) of nuclear matter. These measurements provide new
+constraints on the overall pressure, but do not, by itself, elucidate its
+microscopic origins, including the pressure arising from the symmetry energy,
+that governs much of the internal structure of a neutron star. To correlate
+microscopic constraints from nuclear measurements to the GW170817 constraints,
+we calculate neutron star properties with more than 200 Skyrme energy density
+functionals that describe properties of nuclei. Calculated neutron-star radii
+(R) and the tidal deformabilities which show a strong correlation with pressure
+at twice saturation density. By combining the neutron star EoS extracted from
+the GW170817 event and the EoS of symmetric matter from nucleus-nucleus
+collision experiments, we extract the density dependence of the symmetry
+pressure from 1.2 to 4.5 times saturation density. While the uncertainties in
+the symmetry pressure are large, they can be reduced with new experimental and
+astrophysical results.",1901.07673v1
+2019-01-23,Quantum coherence across bosonic superconductor-anomalous metal-insulator transitions,"After decades of explorations, suffering from low critical temperature and
+subtle nature, whether a metallic ground state exists in a two-dimensional
+system beyond Anderson localization is still a mystery. Supremely, phase
+coherence could be the key that unlocks its intriguing nature. This work
+reveals how quantum phase coherence evolves across bosonic
+superconductor-metal-insulator transitions via magneto-conductance quantum
+oscillations in high-Tc superconducting films. A robust intervening anomalous
+metallic state characterized by both resistance and oscillation amplitude
+saturations in the low temperature regime is detected. By contrast, with
+decreasing temperature the oscillation amplitude monotonically grows on the
+superconducting side, but decreases at low temperatures on the insulating side.
+It suggests that the saturation of phase coherence plays a prominent role in
+the formation of this anomalous metallic state.",1901.07706v1
+2019-01-25,Evanescent Field Functional Cu3-xP Nanoparticles as Effective Saturable Absorbers with high Repeatability for Femtosecond Soliton Pulse generation,"Recently, a new emerging field about heavily-doped colloidal plasmonic
+nanocrystals (NCs) has attracted great attention due to their lower and
+expediently adjustable free carrier densities, lower and tunable LSPR band in
+the spectral range from NIR to MIR and higher optical nonlinearity. These new
+kinds of plasmonic materials will show huge potential and opportunities for
+nonlinear optical applications, such as ultrafast switching, nonlinear sensing
+and pulse laser generation. In this work, we demonstrate that high-quality
+mode-locking and Q-switching pulses at 1560 nm can both be generated by using
+controllable concentration of Cu3-xP NCs solution and fabricating evanescently
+interacted saturable absorbers. Furthermore, the plasmonic NCs material has
+good reproduction for fabricating SA devices and promising potential for
+large-scale industrial production. Our results may attract great attention for
+further investigations of heavily-doped plasmonic NCs as next generation, cheap
+and solution-processed element for fascinating applications in optoelectronic
+devices.",1901.08714v1
+2019-01-28,Calculated threshold of supratransmission phenomena in waveguide arrays with saturable nonlinearity,"In this work, we consider a semi-infinite discrete nonlinear Schr\""odinger
+equation with saturable nonlinearity driven at one edge by a driving force. The
+equation models the dynamics of coupled photorefractive waveguide arrays. It
+has been reported that when the frequency of the driving force is in the
+forbidden band, energy can be transmitted along the lattices provided that the
+driving amplitude is above a critical value. This nonlinear tunneling is called
+supratransmission. Here, we explain the source of supratransmission using
+geometric illustrations. Approximations to the critical amplitude for
+supratransmission are presented as well.",1901.09518v1
+2019-01-30,On the Theoretical Limits of Beam Steering in mmWave Massive MIMO Channels,"Analog Beamsteering (ABS) has emerged as a low complexity, power efficient
+solution for MillimeterWave (mmWave) massive Multiple Input Multiple Output
+(MIMO) systems. Moreover, driven by the low spatial correlation between the
+User Terminals (UTs) with high number of transmit antennas (massive MIMO) at
+the Base Station (BS), ABS can be used to support Multi User (MU) MIMO
+scenarios instead of digital or Hybrid Beamforming (HBF). However, we show in
+this paper, that even with high number of transmit antennas, the HBF can
+achieve better Spectral Efficiency (SE) compared to the MU ABS even in pure
+Line of Sight (LoS) channels. Moreover, we prove that the MU ABS saturates to a
+constant SE at high transmit Signal to Noise Ratio (SNR) and we theoretically
+derive an approximation to that saturation bound in this paper. On the other
+hand, we highlight that the HBF's SE scales with the transmit SNR even in high
+SNR regime. Finally, given the same power consumption and hardware complexity
+as the MU ABS case, we show that HBF asymptotically achieves the optimal SE
+(ideal non interference scenario) when increasing the number of transmit
+antennas.",1901.11404v1
+2019-01-16,Impact of Non-Linear High-Power Amplifiers on Cooperative Relaying Systems,"In this paper, we investigate the impact of the high-power amplifier
+non-linear distortion on multiple relay systems by introducing the soft
+envelope limiter, traveling wave tube amplifier, and solid-state power
+amplifier to the relays. The system employs amplify-and-forward either fixed or
+variable gain relaying and uses the opportunistic relay selection with outdated
+channel state information to select the best relay. The results show that the
+performance loss is small at low rates; however, it is significant for high
+rates. In particular, the outage probability and the bit error rate are
+saturated by an irreducible floor at high rates. The same analysis is pursued
+for the capacity and shows that it is saturated by a detrimental ceiling as the
+average signal-to-noise ratio becomes higher. This result contrasts the case of
+the ideal hardware where the capacity grows indefinitely. Moreover, the results
+show that the capacity ceiling is proportional to the impairment's parameter
+and for some special cases the impaired systems practically operate in
+acceptable conditions. Closed-forms and high SNR asymptotes of the outage
+probability, the bit error rate, and the capacity are derived. Finally,
+analytical expressions are validated by the Monte Carlo simulation.",1902.03176v1
+2019-02-14,A note on rainbow saturation number of paths,"For a fixed graph $F$ and an integer $t$, the \dfn{rainbow saturation number}
+of $F$, denoted by $sat_t(n,\mathfrak{R}(F))$, is defined as the minimum number
+of edges in a $t$-edge-colored graph on $n$ vertices which does not contain a
+\dfn{rainbow copy} of $F$, i.e., a copy of $F$ all of whose edges receive a
+different color, but the addition of any missing edge in any color from $[t]$
+creates such a rainbow copy. Barrus, Ferrara, Vardenbussche and Wenger prove
+that $sat_t(n,\mathfrak{R}(P_\ell))\ge n-1$ for $\ell\ge 4$ and
+$sat_t(n,\mathfrak{R}(P_\ell))\le \lceil \frac{n}{\ell-1} \rceil \cdot
+\binom{\ell-1}{2}$ for $t\ge \binom{\ell-1}{2}$, where $P_\ell$ is a path with
+$\ell$ edges. In this short note, we improve the upper bounds and show that
+$sat_t(n,\mathfrak{R}(P_\ell))\le \lceil \frac{n}{\ell} \rceil \cdot
+\left({{\ell-2}\choose {2}}+4\right)$ for $\ell\ge 5$ and $t\ge 2\ell-5$.",1902.05222v3
+2019-02-15,Measuring algorithmic complexity in chaotic lasers,"Thanks to the simplicity and robustness of its calculation methods,
+algorithmic (or Kolmogorov) complexity appears as a useful tool to reveal
+chaotic dynamics when experimental time series are too short and noisy to apply
+Takens' reconstruction theorem. We measure the complexity in chaotic regimes,
+with and without extreme events (sometimes called optical rogue waves), of
+three different all-solid-state lasers: Kerr lens mode locking femtosecond Ti:
+Sapphire (""fast"" saturable absorber), Nd:YVO4 + Cr:YAG (""slow"" saturable
+absorber) and Nd:YVO4 with modulated losses. We discuss how complexity
+characterizes the dynamics in an understandable way in all cases, and how it
+provides a correction factor to the horizon of predictability given by Lyapunov
+exponents. This approach may be especially convenient to implement schemes of
+chaos control in real time.",1902.05790v2
+2019-02-19,Thermal Emission from Semi-classical Dynamical Systems,"Recently the bound on the Lyapunov exponent $\lambda_L \le 2\pi T/ \hbar$ in
+thermal quantum systems was conjectured by Maldacena, Shenker, and Stanford. If
+we naively apply this bound to a system with a fixed Lyapunov exponent
+$\lambda_L$, it might predict the existence of the lower bound on temperature
+$T \ge \hbar \lambda_L/ 2\pi $. Particularly, it might mean that chaotic
+systems cannot be zero temperature quantum mechanically. Even classical
+dynamical systems, which are deterministic, might exhibit thermal behaviors
+once we turn on quantum corrections. We elaborate this possibility by
+investigating semi-classical particle motions near the hyperbolic fixed point
+and show that indeed quantum corrections may induce energy emission which obeys
+a Boltzmann distribution. We also argue that this emission is related to
+acoustic Hawking radiation in quantum fluid. Besides, we discuss when the bound
+is saturated and show that a particle motion in an inverse harmonic potential
+and $c=1$ matrix model may saturate the bound although they are integrable.",1902.06940v2
+2019-02-19,A Bound on Thermal Relativistic Correlators at Large Spacelike Momenta,"We consider thermal Wightman correlators in a relativistic quantum field
+theory in the limit where the spatial momenta of the insertions become large
+while their frequencies stay fixed. We show that, in this limit, the size of
+these correlators is bounded by $e^{-\beta R}$, where $R$ is the radius of the
+smallest sphere that contains the polygon formed by the momenta. We show that
+perturbative quantum field theories can saturate this bound through suitably
+high-order loop diagrams. We also consider holographic theories in
+$d$-spacetime dimensions, where we show that the leading two-point function of
+generalized free-fields saturates the bound in $d = 2$ and is below the bound
+for $d > 2$. We briefly discuss interactions in holographic theories and
+conclude with a discussion of several open problems.",1902.07203v1
+2019-02-25,Universal Hall coefficient correction in strongly coupled Cr-SiO$_2$ nanogranular metals,"The microstructure and electrical transport of Cr$_x$(SiO$_2$)$_{1-x}$
+nanogranular films with Cr volume faction $x$$\simeq$0.67 and 0.72 are
+systematically investigated. The transmission electron microscopy images and
+elemental mappings indicate that the films are quite inhomogeneous: some Cr
+granules directly connect to others while some Cr granules with size $\sim$1 to
+$\sim$3\,nm disperse in the SiO$_2$ dielectric matrix. For each film, the Hall
+coefficient $R_H$ varies linearly with the natural logarithm of temperature,
+i.e., $\Delta R_H$$\propto$$\ln T$, above $\sim$60\,K, saturates at
+$\sim$60\,K, and retains the saturating value below $\sim$60\,K. The
+temperature dependence of Hall coefficient can be explained by the recent
+theory in granular metals and originates from \emph{virtual diffusion} of
+electrons through the metallic granules. For the conductivity $\sigma$, a
+robust $\Delta \sigma$$\propto$$\sqrt{T}$ law is observed from $\sim$50 down to
+2\,K. The behavior of the conductivity stems from the ``Altshuler-Aronov""
+correction, whose influence on the Hall coefficient is not present in the
+films.",1902.09264v1
+2019-03-02,A complete Heyting algebra whose Scott space is non-sober,"We prove that (1) for any complete lattice $L$, the set $\mathcal{D}(L)$ of
+all nonempty saturated compact subsets of the Scott space of $L$ is a complete
+Heyting algebra (with the reverse inclusion order); and (2) if the Scott space
+of a complete lattice $L$ is non-sober, then the Scott space of
+$\mathcal{D}(L)$ is non-sober. Using these results and the Isbell's example of
+a non-sober complete lattice, we deduce that there is a complete Heyting
+algebra whose Scott space is non-sober, thus give a positive answer to a
+problem posed by Jung. We will also prove that a $T_0$ space is well-filtered
+iff its upper space (the set $\mathcal{D}(X)$ of all nonempty saturated compact
+subsets of $X$ equipped with the upper Vietoris topology) is well-filtered,
+which answers another open problem.",1903.00615v1
+2019-03-04,Mixed-Triggered Reliable Control for Singular Networked Cascade Control Systems with Randomly Occurring Cyber Attack,"In this paper, the issue of mixed-triggered reliable dissipative control is
+investigated for singular networked cascade control systems (NCCSs) with
+actuator saturation and randomly occurring cyber attacks. In order to utilize
+the limited communication resources effectively, a more general mixed-triggered
+scheme is established which includes both schemes namely time-triggered and
+event-triggered in a single framework. In particular, two main factors are
+incorporated to the proposed singular NCCS model namely, actuator saturation
+and randomly occurring cyber attack, which is an important role to damage the
+overall network security. By employing Lyapunov-Krasovskii stability theory, a
+new set of sufficient conditions in terms of linear matrix inequalities (LMIs)
+is derived to guarantee the singular NCCSs to be admissible and strictly
+(Q,S,R)-dissipative. Subsequently, a power plant boiler-turbine system based on
+a numerical example is provided to demonstrate the effectiveness of the
+proposed control scheme.",1903.01024v1
+2019-03-07,ENIGMA-NG: Efficient Neural and Gradient-Boosted Inference Guidance for E,"We describe an efficient implementation of clause guidance in
+saturation-based automated theorem provers extending the ENIGMA approach.
+Unlike in the first ENIGMA implementation where fast linear classifier is
+trained and used together with manually engineered features, we have started to
+experiment with more sophisticated state-of-the-art machine learning methods
+such as gradient boosted trees and recursive neural networks. In particular the
+latter approach poses challenges in terms of efficiency of clause evaluation,
+however, we show that deep integration of the neural evaluation with the ATP
+data-structures can largely amortize this cost and lead to competitive
+real-time results. Both methods are evaluated on a large dataset of theorem
+proving problems and compared with the previous approaches. The resulting
+methods improve on the manually designed clause guidance, providing the first
+practically convincing application of gradient-boosted and neural clause
+guidance in saturation-style automated theorem provers.",1903.03182v1
+2019-03-11,Observer-Based Drag-Tracking Guidance for Entry Vehicles Considering Input Saturation Constraint,"This paper studies the drag-tracking guidance design problem of uncertain
+entry vehicles. With employing a Nussbaum type function to deal with input
+saturation constraint, an output feedback guidance law (bank angle magnitude)
+with a high-gain observer is constructed that makes the drag-tracking error
+converge near zero in the presence of uncertainties. It is also worthy to claim
+that, in contrast to the existing results whose envelope of uncertainty merely
+depends on the drag error, the considered uncertainty is allowed to be not
+bigger than a function of drag error and integral term of drag error, which
+inevitably occurs in practice. The Monte Carlo simulation is done to illustrate
+the advantage of the developed method.",1903.04931v1
+2019-03-19,Quasilinear Approach of the Whistler Heat-Flux Instability in the Solar Wind,"The hot beaming (or strahl) electrons responsible for the main electron
+heat-flux in the solar wind are believed to be self-regulated by the
+electromagnetic beaming instabilities, also known as the heat-flux
+instabilities. Here we report the first quasi-linear theoretical approach of
+the whistler unstable branch able to characterize the long-term saturation of
+the instability as well as the relaxation of the electron velocity
+distributions. The instability saturation is not solely determined by the drift
+velocities, which undergo only a minor relaxation, but mainly from a concurrent
+interaction of electrons with whistlers that induces (opposite) temperature
+anisotropies of the core and beam populations and reduces the effective
+anisotropy. These results might be able to (i) explain the low intensity of the
+whistler heat-flux fluctuations in the solar wind (although other explanations
+remain possible and need further investigation), and (ii) confirm a reduced
+effectiveness of these fluctuations in the relaxation and isotropization of the
+electron strahl and in the regulation of the electron heat-flux.",1903.08005v1
+2019-04-01,Modulational stability of nonlinear saturated gravity waves,"Stationary gravity waves, such as mountain lee waves, are effectively
+described by Grimshaw's dissipative modulation equations even in high altitudes
+where they become nonlinear due to their large amplitudes. In this theoretical
+study, a wave-Reynolds number is introduced to characterize general solutions
+to these modulation equations. This non-dimensional number relates the vertical
+linear group velocity with wavenumber, pressure scale height and kinematic
+molecular/eddy viscosity. It is demonstrated by analytic and numerical methods
+that Lindzen-type waves in the saturation region, i.e. where the wave-Reynolds
+number is of order unity, destabilize by transient perturbations. It is
+proposed that this mechanism may be a generator for secondary waves due to
+direct wave-mean-flow interaction. By assumption the primary waves are exactly
+such that altitudinal amplitude growth and viscous damping are balanced and by
+that the amplitude is maximized. Implications of these results on the relation
+between mean-flow acceleration and wave breaking heights are discussed.",1904.00666v1
+2019-04-08,QCD evolution based evidence for the onset of gluon saturation in exclusive photo-production of vector mesons,"We investigate photo-production of vector mesons J/Psi and Upsilon measured
+both at HERA and LHC, using 2 particular fits of inclusive unintegrated gluon
+distributions, based on non-linear Balitsky-Kovchegov evolution (Kutak-Sapeta
+gluon; KS) and next-to-leading order Balitsky-Fadin-Kuraev-Lipatov evolution
+(Hentschinski-Sabio Vera-Salas gluon; HSS). We find that linear next-to-leading
+order evolution can only describe production at highest energies, if
+perturbative corrections are increased to unnaturally large values; rendering
+this corrections to a perturbative size, the growth with energy is too strong
+and the description fails. At the same time, the KS gluon, which we explore
+both with and without non-linear corrections, requires the latter to achieve an
+accurate description of the energy dependence of data. We interpret this
+observation as a clear signal for the presence of high gluon densities in the
+proton, characteristic for the onset of gluon saturation.",1904.04394v2
+2019-04-21,Oxidized silicon sulfide: stability and electronic properties of a novel two-dimensional material,"Isolated oxygen impurities and fully oxidized structures of four stable
+two-dimensional (2D) SiS structures are investigated by {\em ab initio} density
+functional calculations. Binding energies of oxygen impurities for all the four
+2D SiS structures are found larger than those for phosphorene, due to the lower
+electronegativity of Si atoms. The most stable configurations of isolated
+oxygen impurities for different 2D SiS structures are decided and the
+corresponding 2D structures with saturated oxidation (SiSO) are predicted.
+Among all the four fully oxidized structures, $\alpha$-SiSO is demonstrated to
+be stable by phonon spectra calculations and molecular dynamics (MD)
+simulations. Electronic structure calculations indicate that $\alpha$-SiSO
+monolayer is semiconducting with a direct band gap of ${\approx}2.28$~eV, which
+can be effectively tuned by in-layer strain. The value of band gap and
+thermodynamic stability are found depending sensitively on the saturation level
+of oxygen.",1904.09614v1
+2019-04-25,JPEG XT Image Compression with Hue Compensation for Two-Layer HDR Coding,"We propose a novel JPEG XT image compression with hue compensation for
+two-layer HDR coding. LDR images produced from JPEG XT bitstreams have some
+distortion in hue due to tone mapping operations. In order to suppress the
+color distortion, we apply a novel hue compensation method based on the
+maximally saturated colors. Moreover, the bitstreams generated by using the
+proposed method are fully compatible with the JPEG XT standard. In an
+experiment, the proposed method is demonstrated not only to produce images with
+small hue degradation but also to maintain well-mapped luminance, in terms of
+three kinds of criterion: TMQI, hue value in CIEDE2000, and the maximally
+saturated color on the constant-hue plane.",1904.11315v1
+2019-05-06,Insights on Skyrme parameters from GW170817,"The binary neutron-star merger event, GW170817, has cast a new light on
+nuclear physics research. Using a neutron-star model that includes a crust
+equation of state (EoS), we calculate the properties of a 1.4 solar-mass
+neutron star. The model incorporates more than 200 Skyrme energy density
+functionals, which describe nuclear matter properties, in the outer liquid core
+region of the neutron star. We find a power-law relation between the
+neutron-star tidal deformability, $\Lambda$, and the neutron-star radius, R.
+Without an explicit crust EoS, the model predicts smaller R and the difference
+becomes significant for stars with large radii. To connect the neutron star
+properties with nuclear matter properties, we confront the predicted values for
+$\Lambda$, against the Taylor expansion coefficients of the Skyrme
+interactions. There is no pronounced correlation between Skyrme parameters in
+symmetric nuclear matter and neutron star properties. However, we find the
+strongest correlation between $\Lambda$ and $K_{sym}$, the curvature of the
+density dependence of the symmetry energy at saturation density. At twice the
+saturation density, our calculations show a strong correlation between
+$\Lambda$ and total pressure providing guidance to laboratory nucleus-nucleus
+collision experiments.",1905.02601v1
+2019-05-15,Maximal Quantum Fisher Information for Mixed States,"We study quantum metrology for unitary dynamics. Analytic solutions are given
+for both the optimal unitary state preparation starting from an arbitrary mixed
+state and the corresponding optimal measurement precision. This represents a
+rigorous generalization of known results for optimal initial states and upper
+bounds on measurement precision which can only be saturated if pure states are
+available. In particular, we provide a generalization to mixed states of an
+upper bound on measurement precision for time-dependent Hamiltonians that can
+be saturated with optimal Hamiltonian control. These results make precise and
+reveal the full potential of mixed states for quantum metrology.",1905.06101v2
+2019-05-17,Pattern formation induced by intraspecific interactions in a predator-prey system,"Differential diffusion is a source of instability in population dynamics
+systems when species diffuse with different rates. Predator-prey systems show
+this instability only under certain specific conditions, usually requiring
+Holling-type functionals involved. Here we study the effects of intraspecific
+cooperation and competition on diffusion-driven instability in a predator-prey
+system with a different structure. We conduct the analysis on a generalized
+population dynamics that bounds intraspecific and interspecific interactions
+with Verhulst-type saturation terms instead of Holling-type functionals. We
+find that instability occurs due to the intraspecific saturation or
+intraspecific interactions, both cooperative and competitive. We present
+numerical simulations and show spatial patterns due to diffusion.",1905.07256v1
+2019-05-23,ENIGMAWatch: ProofWatch Meets ENIGMA,"In this work we describe a new learning-based proof guidance -- ENIGMAWatch
+-- for saturation-style first-order theorem provers. ENIGMAWatch combines two
+guiding approaches for the given-clause selection implemented for the E ATP
+system: ProofWatch and ENIGMA. ProofWatch is motivated by the watchlist (hints)
+method and based on symbolic matching of multiple related proofs, while ENIGMA
+is based on statistical machine learning. The two methods are combined by using
+the evolving information about symbolic proof matching as an additional
+information that characterizes the saturation-style proof search for the
+statistical learning methods. The new system is experimentally evaluated on a
+large set of problems from the Mizar Library. We show that the added
+proof-matching information is considered important by the statistical machine
+learners, and that it leads to improvements in E's Performance over ProofWatch
+and ENIGMA.",1905.09565v2
+2019-05-25,Subregion complexity in holographic thermalization with dS boundary,"We study the time evolution of holographic subregion complexity (HSC) in
+Vaidya spacetime with dS boundary. The subregion on the boundary is chosen to
+be a sphere within the cosmological horizon. It is found that the behaviour of
+HSC is similar to that in cases with flat boundary. The whole evolution can be
+divided into four stages: First, it grows almost linearly, then the growth
+slows down; After reaching a maximum it drops down quickly and gets to
+saturation finally. The linear growth rate in the first stage is found to
+depend almost only on the the mass parameter. As the subregion size approaches
+the cosmological horizon, this stage is expected to last forever with the
+subsequent three stages washed out. The saturation time $\tilde{t}_{sat}$
+depends almost only on the subregion size $\tilde{R}$ as $\tilde{t}_{sat} =
+\tanh^{-1} (\tilde{R})$ which is linear in $\tilde{R}$ when $\tilde{R}$ is
+small but logarithmically divergent as $\tilde{R}$ approaches the cosmological
+horizon.",1905.10605v3
+2019-05-26,Avoiding Scalability Collapse by Restricting Concurrency,"Saturated locks often degrade the performance of a multithreaded application,
+leading to a so-called scalability collapse problem. This problem arises when a
+growing number of threads circulating through a saturated lock causes the
+overall application performance to fade or even drop abruptly. This problem is
+particularly (but not solely) acute on oversubscribed systems (systems with
+more threads than available hardware cores). In this paper, we introduce GCR
+(generic concurrency restriction), a mechanism that aims to avoid the
+scalability collapse. GCR, designed as a generic, lock-agnostic wrapper,
+intercepts lock acquisition calls, and decides when threads would be allowed to
+proceed with the acquisition of the underlying lock. Furthermore, we present
+GCR-NUMA, a non-uniform memory access (NUMA)-aware extension of GCR, that
+strives to ensure that threads allowed to acquire the lock are those that run
+on the same socket. The extensive evaluation that includes more than two dozen
+locks, three machines and three benchmarks shows that GCR brings substantial
+speedup (in many cases, up to three orders of magnitude) in case of contention
+and growing thread counts, while introducing nearly negligible slowdown when
+the underlying lock is not contended. GCR-NUMA brings even larger performance
+gains starting at even lighter lock contention.",1905.10818v2
+2019-05-27,Skew key polynomials and a generalized Littlewood-Richardson rule,"Young's lattice is a partial order on integer partitions whose saturated
+chains correspond to standard Young tableaux, one type of combinatorial object
+that generates the Schur basis for symmetric functions. Generalizing Young's
+lattice, we introduce a new partial order on weak compositions that we call the
+key poset. Saturated chains in this poset correspond to standard key tableaux,
+the combinatorial objects that generate the key polynomials, a nonsymmetric
+polynomial generalization of the Schur basis. Generalizing skew Schur
+functions, we define skew key polynomials in terms of this new poset. Using
+weak dual equivalence, we give a nonnegative weak composition
+Littlewood-Richardson rule for the key expansion of skew key polynomials,
+generalizing the flagged Littlewood-Richardson rule of Reiner and Shimozono.",1905.11526v3
+2019-06-12,Outcoupling from a Bose-Einstein condensate in the strong-field limit,"Atoms can be extracted from a trapped Bose-Einstein condensate (BEC) by
+driving spin-flips to untrapped states. The coherence properties of the BEC are
+transfered to the released atoms, creating a coherent beam of matter refered to
+as an atom laser. In this work, the extraction of atoms from a BEC is
+investigated numerically by solving a coupled set of Gross-Pitaevskii equations
+in up to three dimensions. The result is compared to experimental data and a
+semiclassical rate model. In the weak-coupling regime, quantitative agreement
+is reached between theory and experiment and a semiclassical rate model. In the
+strong-coupling regime, the atom laser enters a trapped state that manifests
+itself in a saturation of the rate of out-coupled atoms observed in new
+experimental data. The semiclassical rate model fails, but the numerical
+descriptions yield qualitative agreement with experimental data at the onset of
+saturation.",1906.05196v1
+2019-06-15,Constraints on nonlocality in networks from no-signaling and independence,"Generalising the concept of Bell nonlocality to networks leads to novel forms
+of correlations, the characterization of which is however challenging. Here we
+investigate constraints on correlations in networks under the two natural
+assumptions of no-signaling and independence of the sources. We consider the
+``triangle network'', and derive strong constraints on correlations even though
+the parties receive no input, i.e. each party performs a fixed measurement. We
+show that some of these constraints are tight, by constructing explicit local
+models (i.e. where sources distribute classical variables) that can saturate
+them. However, we also observe that other constraints can apparently not be
+saturated by local models, which opens the possibility of having nonlocal (but
+non-signaling) correlations in the triangle network.",1906.06495v2
+2019-06-17,Doppler-free saturation of the cascade fluorescence that follows excitation of the $5s \to 6p $ transition in atomic rubidium,"We present an experimental scheme that produces Doppler-free spectra of the
+$5s \to 6p $ second resonance transition in atomic rubidium. The experiment
+uses the saturation of the cascade fluorescence that occurs when thermal
+rubidium atoms interact with two counterpropagating $420 $ nm laser beams of
+comparable intensity. Part of the excited atomic population goes through the
+$5p_{3/2}$ level which then decays by emission of $780$ nm photons. Narrow dips
+appear in this otherwise broad $780$ nm fluorescence, which allows resolution
+of the $6p_{3/2}$ hyperfine structure. A rate equation model is used to
+interpret the spectra. It is also shown that these narrow peaks can be used to
+lock the frequency of the $420 $ nm laser. Using a second beam modulated in
+frequency produces three sets of spectra with known frequency spacings that can
+be used to perform an all-optical measurement of the hyperfine splittings of
+the $6p_{3/2} $ manifold in rubidium.",1906.07114v1
+2019-06-16,Fronts in two-phase porous flow problems: effects of hysteresis and dynamic capillarity,"In this work, we study the behaviour of saturation fronts for two phase flow
+through a long homogeneous porous column. In particular, the model includes
+hysteresis and dynamic effects in the capillary pressure and hysteresis in the
+permeabilities. The analysis uses travelling wave approximation. Entropy
+solutions are derived for Riemann problems that are arising in this context.
+These solutions belong to a much broader class compared to the standard Oleinik
+solutions, where hysteresis and dynamic effects are neglected. The relevant
+cases are examined and the corresponding solutions are categorized. They
+include non-monotone profiles, multiple shocks and self-developing stable
+saturation plateaus. Numerical results are presented that illustrate the
+mathematical analysis. Finally, we compare experimental results with our
+theoretical findings.",1906.08134v2
+2019-06-19,Entropy Variations and Light Ray Operators from Replica Defects,"We study the defect operator product expansion (OPE) of displacement
+operators in free and interacting conformal field theories using replica
+methods. We show that as $n$ approaches $1$ a contact term can emerge when the
+OPE contains defect operators of twist $d-2$. For interacting theories and
+general states we give evidence that the only possibility is from the defect
+operator that becomes the stress tensor in the $n\to 1$ limit. This implies
+that the quantum null energy condition (QNEC) is always saturated for CFTs with
+a twist gap. As a check, we show independently that in a large class of near
+vacuum states, the second variation of the entanglement entropy is given by a
+simple correlation function of averaged null energy operators as studied by
+Hofman and Maldacena. This suggests that sub-leading terms in the the defect
+OPE are controlled by a defect version of the spin-3 non-local light ray
+operator and we speculate about the possible origin of such a defect operator.
+For free theories this contribution condenses to a contact term that leads to
+violations of QNEC saturation.",1906.08274v1
+2019-06-24,Burst behavior due to quasimode excited by stimulated Brillouin scattering in high-intensity laser-plasma interaction,"The strong-coupling mode, called quasimode, will be excited by stimulated
+Brillouin scattering (SBS) in high-intensity laser-plasma interaction. And SBS
+of quasimode will compete with SBS of fast mode (or slow mode) in multi-ion
+species plasmas, thus leading to a low-frequency burst behavior of SBS
+reflectivity. The competition of quasimode and ion-acoustic wave (IAW) is an
+important saturation mechanism of SBS in high-intensity laser-plasma
+interaction. These results give a clear explanation to the low-frequency
+periodic burst behavior of SBS and should be considered as a saturation
+mechanism of SBS in high-intensity laser-plasma interaction.",1906.11616v1
+2019-07-06,The saturation number of powers of graded ideals,"Let $S=K[x_1,\ldots,x_n]$ be the polynomial ring in $n$ variables over a
+field $K$ with maximal ideal $\frak{m}=(x_1,...,x_n)$, and let $I$ be a graded
+ideal of $S$. In this paper, we define the saturation number $\sat(I)$ of $I$
+to be the smallest non-negative integer $k$ such that $I:\mm^{k+1}= I:\mm^k$.
+We show that $f(k)$ is linearly bounded, and that $f(k)$ is a quasi-linear
+function for $k\gg 0$, if $I$ is a monomial ideal. Furthermore, we show that
+$\sat(I^k)=k$ if $I$ is a principal Borel ideal and prove that $\sat(I_{d,n}^k)
+=\max\{l\:\; (kd-l)/(k-l) \leq n\},$ where $I_{d,n}$ is the squarefree Veronese
+ideal generated in degree $d$. \end{abstract}",1907.03154v3
+2019-07-08,Matter-Geometry entanglement in quantum cosmology,"We present a study of the evolution of entanglement entropy of matter and
+geometry in quantum cosmology. For a variety of Gaussian initial states and
+their linear combinations, and with evolution defined with respect to a
+relational time, we show numerically that (i) entanglement entropy increases
+rapidly at very early times, and subsequently saturates to a constant non-zero
+value, and (ii) that the saturation value of this entropy is a linear function
+of the energy associated to the quantum state: $S_{\text{ent}}^\psi = \gamma
+\langle \hat{H} \rangle_\psi$. These results suggest a remnant of quantum
+entanglement in the macroscopic Universe from the era of the Big Bang,
+independent of the initial state parameters, and a ""First Law"" associated with
+matter-gravity entanglement entropy in quantum gravity.",1907.03776v3
+2019-07-10,Nonlinear evolution of the whistler heat flux instability,"We use the one-dimensional TRISTAN-MP particle-in-cell code to model the
+nonlinear evolution of the whistler heat flux instability that was proposed by
+Gary et al. (1999, 2000) to regulate the electron heat flux in the solar wind
+and astrophysical plasmas. The simulations are initialized with electron
+velocity distribution functions typical for the solar wind. We perform a set of
+simulations at various initial values of the electron heat flux and
+$\beta_{e}$. The simulations show that parallel whistler waves produced by the
+whistler heat flux instability saturate at amplitudes consistent with the
+spacecraft measurements. The simulations also reproduce the correlations of the
+saturated whistler wave amplitude with the electron heat flux and $\beta_{e}$
+revealed in the spacecraft measurements. The major result is that parallel
+whistler waves produced by the whistler heat flux instability do not
+significantly suppress the electron heat flux. The presented simulations
+indicate that coherent parallel whistler waves observed in the solar wind are
+unlikely to regulate the heat flux of solar wind electrons.",1907.04878v1
+2019-07-01,Direct Measurement of the Elastohydrodynamic Lift Force at the Nanoscale,"We present the first direct measurement of the elastohydrodynamic lift force
+acting on a sphere moving within a viscous liquid, near and along a soft
+substrate under nanometric confinement. Using atomic force microscopy, the lift
+force is probed as a function of the gap size, for various driving velocities,
+viscosities, and stiffnesses. The force increases as the gap is reduced and
+shows a saturation at small gap. The results are in excellent agreement with
+scaling arguments and a quantitative model developed from the soft lubrication
+theory, in linear elasticity, and for small compliances. For larger
+compliances, or equivalently for smaller confinement length scales, an
+empirical scaling law for the observed saturation of the lift force is given
+and discussed.",1907.05849v2
+2019-07-17,Unitarity Entropy Bound: Solitons and Instantons,"We show that non-perturbative entities such as solitons and instantons
+saturate bounds on entropy when the theory saturates unitarity. Simultaneously,
+the entropy becomes equal to the area of the soliton/instanton. This is
+strikingly similar to black hole entropy despite absence of gravity. We explain
+why this similarity is not an accident. We present a formulation that allows to
+apply the entropy bound to instantons. The new formulation also eliminates
+apparent violations of the Bekenstein entropy bound by some
+otherwise-consistent unitary systems. We observe that in QCD, an isolated
+instanton of fixed size and position violates the entropy bound for strong 't
+Hooft coupling. At critical 't Hooft coupling the instanton entropy is equal to
+its area.",1907.07332v1
+2019-07-23,Stability of Big Surface Bubbles: Impact of Evaporation and Bubbles Size,"Surface bubbles have attracted much interest in the past decades. In this
+article, we propose to explore the lifetime and thinning dynamics of
+centimetric surface bubbles. We study the impact of the bubbles size as well as
+that of the atmospheric humidity through a careful control and systematic
+variation of the relative humidity in the measuring chamber. We first adress
+the question of the drainage under saturated water vapor conditions and show
+that a model including both capillary and gravity driven drainage provides the
+best prediction for this process. Additionally, unprecedented statistics on the
+bubbles lifetimes confirm experimentally that this parameter is set by
+evaporation to leading order. We make use of a model based on the overall
+thinning dynamics of the thin film and assume a rupture thickness of the order
+10-100 nm to obtain a good representation of these data. For experiments
+conducted far from saturation, the convective evaporation of the bath is shown
+to dominate the overall mass loss in the cap film due to evaporation.",1907.09734v2
+2019-07-24,Inherent Limit to Coherent Phonon Generation under Non-Resonant Light Field Driving,"Coherent manipulation of quasi-particles is a crucial method to realize
+ultrafast switching of the relating macroscopic order. In this letter, we
+studied coherent phonon generation under strong light field which allows to
+induce non-perturbative nonlinear optical phenomena in solids. The efficiency
+of coherent phonon generation starts to saturate and deviate from the
+pronounced linear power dependence when the light intensity goes into the
+non-perturbative regime. We propose a novel theoretical model based on Floquet
+picture and show that the saturation is due to a limitation of the driving
+force inherent in non-resonant driving of the electronic system in the
+non-perturbative regime.",1907.10335v1
+2019-07-25,Capturing the shear and secondary compression wave: High frame rate ultrasound imaging in saturated foams,"We experimentally observe the shear and secondary compression wave inside
+soft porous water-saturated melamine foams by high frame rate ultrasound
+imaging. Both wave speeds are supported by the weak frame of the foam. The
+first and second compression waves show opposite polarity, as predicted by Biot
+theory. Our experiments have direct implications for medical imaging: Melamine
+foams exhibit a similar microstructure as lung tissue. In the future, combined
+shear wave and slow compression wave imaging might provide new means of
+distinguishing malignant and healthy pulmonary tissue.",1907.11276v2
+2019-07-27,Adaptive Flight Control in the Presence of Limits on Magnitude and Rate,"Input constraints as well as parametric uncertainties must be accounted for
+in the design of safe control systems. This paper presents an adaptive
+controller for multiple-input-multiple-output (MIMO) plants with input
+magnitude and rate saturation in the presence of parametric uncertainties. A
+filter is introduced in the control path to accommodate the presence of rate
+limits. An output feedback adaptive controller is designed to stabilize the
+closed loop system even in the presence of this filter. The overall control
+architecture includes adaptive laws that are modified to account for the
+magnitude and rate limits. Analytical guarantees of bounded solutions and
+satisfactory tracking are provided. Three flight control simulations with
+nonlinear models of the aircraft dynamics are provided to demonstrate the
+efficacy of the proposed adaptive controller for open loop stable and unstable
+systems in the presence of uncertainties in the dynamics as well as input
+magnitude and rate saturation.",1907.11913v1
+2019-07-31,Critical slowing down in the bistable regime of circuit quantum electrodynamics,"We investigate the dynamics of the bistable regime of the generalized
+Jaynes-Cummings Hamiltonian (GJC), realised by a circuit quantum
+electrodynamics (cQED) system consisting of a transmon qubit coupled to a
+microwave cavity. In this regime we observe critical slowing down in the
+approach to the steady state. By measuring the response of the cavity to a step
+function drive pulse we characterize this slowing down as a function of driving
+frequency and power. We find that the critical slowing down saturates as the
+driving power is increased. We compare these results with the predictions of
+analytical and numerical calculations both with and without the Duffing
+approximation. We find that the Duffing approximation incorrectly predicts that
+the critical slowing down timescale increases exponentially with the drive,
+whereas the GJC model accurately predicts the saturation seen in our data,
+suggesting a different process of quantum activation.",1907.13592v1
+2019-08-02,Realization of Ohmic-contact and velocity saturation in organic field-effect transistors by crystallized monolayer,"The contact resistance limits the down-scaling and operating range of OFETs.
+With the monolayer (1L) organic crystals and non-destructive
+metal/semiconductor interfaces, intrinsic mobility of 12.5 cm2V-1s-1 and Ohmic
+contact resistance of 40 ohm-cm were achieved. The on/off ratio maintained at
+10^3 even at a small VDS of -0.1 mV. High current density of 4.2 uA/um was
+achieved with the 1L-crystal as the active layer. At such high current density,
+the velocity saturation and channel self-heating effects are observed in OFETs
+for the first time. In addition to the low contact resistance and
+high-resolution lithography, we suggest the thermal management of the high
+mobility OFETs will be the next major challenge to achieve high-speed densely
+integrated flexible electronics.",1908.01032v1
+2019-08-15,Probabilistic Saturations and Alt's Problem,"Alt's problem, formulated in 1923, is to count the number of four-bar
+linkages whose coupler curve interpolates nine general points in the plane.
+This problem can be phrased as counting the number of solutions to a system of
+polynomial equations which was first solved numerically using homotopy
+continuation by Wampler, Morgan, and Sommese in 1992. Since there is still not
+a proof that all solutions were obtained, we consider upper bounds for Alt's
+problem by counting the number of solutions outside of the base locus to a
+system arising as the general linear combination of polynomials. In particular,
+we derive effective symbolic and numeric methods for studying such systems
+using probabilistic saturations that can be employed using both finite fields
+and floating-point computations. We give bounds on the size of finite field
+required to achieve a desired level of certainty. These methods can also be
+applied to many other problems where similar systems arise such as computing
+the volumes of Newton-Okounkov bodies and computing intersection theoretic
+invariants including Euler characteristics, Chern classes, and Segre classes.",1908.06020v1
+2019-08-18,State Synchronization for Homogeneous Networks of Non-introspective Agents in Presence of Input Saturation -A Scale-free Protocol Design,"This paper studies global and semi-global regulated state synchronization of
+homogeneous networks of non-introspective agents in presence of input
+saturation based on additional information exchange where the reference
+trajectory is given by a so-called exosystem which is assumed to be globally
+reachable. Our protocol design methodology does not need any knowledge of the
+directed network topology and the spectrum of the associated Laplacian matrix.
+Moreover, the proposed protocol is scalable and achieves synchronization for
+any arbitrary number of agents.",1908.06535v1
+2019-08-19,A hue-preserving tone mapping scheme based on constant-hue plane without gamut problem,"We propose a novel hue-preserving tone mapping scheme. Various tone mapping
+operations have been studied so far, but there are very few works on color
+distortion caused in image tone mapping. First, LDR images produced from HDR
+ones by using conventional tone mapping operators (TMOs) are pointed out to
+have some distortion in hue values due to clipping and rounding quantization
+processing. Next,we propose a novel method which allows LDR images to have the
+same maximally saturated color values as those of HDR ones. Generated LDR
+images by the proposed method have smaller hue degradation than LDR ones
+generated by conventional TMOs. Moreover, the proposed method is applicable to
+any TMOs. In an experiment, the proposed method is demonstrated not only to
+produce images with small hue degradation but also to maintain well-mapped
+luminance, in terms of three objective metrics: TMQI, hue value in CIEDE2000,
+and the maximally saturated color on the constant-hue plane in the RGB color
+space.",1908.06557v1
+2019-08-26,Robustness of interferometric complementarity under Decoherence,"Interferometric complementarity is known to be one of the most nonclassical
+manifestations of the quantum formalism. It is commonly known as wave-particle
+duality and has been studied presently from the perspective of quantum
+information theory where wave and particle nature of a quantum system, called
+quanton, are characterised by coherence and path distinguishability
+respectively. We here consider the effect of noisy detectors on the
+complementarity relation. We report that by suitably choosing the initial
+quanton and the detector states along with the proper interactions between the
+quanton and the detectors, one can reduce the in uence of noisy environment on
+complementarity, thereby pushing it towards saturation. To demonstrate this,
+three kinds of noise on detectors and their roles on the saturation of the
+complementarity relation are extensively studied. We also observe that for
+fixed values of parameters involved in the process, asymmetric quanton state
+posses low value of coherence while it can have a higher amount of
+distinguishability, and hence it has the potential to enhance the duality
+relation.",1908.09697v2
+2019-08-28,A physically based model for the electrical conductivity of water-saturated porous media,"Electrical conductivity is one of the most commonly used geophysical method
+for reservoir and environmental studies. Its main interest lies in its
+sensitivity to key properties of storage and transport in porous media. Its
+quantitative use therefore depends on the efficiency of the petrophysical
+relationship to link them. In this work, we develop a new physically based
+model for estimating electrical conductivity of saturated porous media. The
+model is derived assuming that the porous media is represented by a bundle of
+tortuous capillary tubes with a fractal pore-size distribution. The model is
+expressed in terms of the porosity, electrical conductivity of the pore liquid
+and the microstructural parameters of porous media. It takes into account the
+interface properties between minerals and pore water by introducing a surface
+conductivity. Expressions for the formation factor and hydraulic tortuosity are
+also obtained from the model derivation. The model is then successfully
+compared with published data and performs better than previous models. The
+proposed approach also permits to relate the electrical conductivity to other
+transport properties such as the hydraulic conductivity.",1908.10601v1
+2019-08-31,Effective modelling of adsorption monolayers built of complex molecules,"Random sequential adsorption algorithm is a popular tool for modelling
+structure of monolayers built in irreversible adsorption experiments. However,
+this algorithm becomes very inefficient when the density of molecules in a
+layer rises. This problem has already been solved for a very limited range of
+basic shapes. This study presents a solution that can be used for any molecule
+occupying the surface that can be modelled by any number of different disks.
+Additionally, the presented algorithm stops when there is no possibility to add
+another shape to the monolayer. This allows to study properties of fully
+saturated, two-dimensional random packings built of complex shapes. For
+instance, the presented algorithm has been used to determine the mean saturated
+packing fractions of monolayers built of dimers and fibrinogen.",1909.00289v2
+2019-09-02,Remarkable nuances of crystallization: From ordinary crystal nucleation to rival mechanisms of crystallite coalescence,"Crystal growth and crystal coalescence processes in supercooled systems
+strongly depend on the concentration of crystallization centers. We perform
+atomistic dynamics simulations of the crystallization process in the ultrathin
+metallic film at different supercooling levels corresponding to supercooled
+liquid and amorphous solid states. Scaled relations are applied to identify the
+characteristic regimes in the time-dependent crystalline nuclei concentration:
+steady-state nucleation regime, saturation regime and coalescence regime. We
+show that the crystal growth at the saturation regime appears due to mixing
+nucleation and coalescence processes. We find that the crystallite coalescence
+realizes mainly through the mechanism of restructurization/absorption of
+crystal nuclei, whereas the mechanism of oriented attachment is manifested only
+at low levels of supercooling.",1909.00771v1
+2019-09-09,Convergence of least squares estimators in the adaptive Wynn algorithm for a class of nonlinear regression models,"The paper continues the authors' work on the adaptive Wynn algorithm in a
+nonlinear regression model. In the present paper it is shown that if the mean
+response function satisfies a condition of `saturated identifiability', which
+was introduced by Pronzato \cite{Pronzato}, then the adaptive least squares
+estimators are strongly consistent. The condition states that the regression
+parameter is identifiable under any saturated design, i.e., the values of the
+mean response function at any $p$ distinct design points determine the
+parameter point uniquely where, typically, $p$ is the dimension of the
+regression parameter vector. Further essential assumptions are compactness of
+the experimental region and of the parameter space together with some natural
+continuity assumptions. If the true parameter point is an interior point of the
+parameter space then under some smoothness assumptions and asymptotic
+homoscedasticity of random errors the asymptotic normality of adaptive least
+squares estimators is obtained.",1909.03763v1
+2019-09-11,Momentum-space entanglement after a quench in one-dimensional disordered fermionic systems,"We numerically investigate the momentum-space entanglement entropy and
+entanglement spectrum of the random-dimer model and its generalizations, which
+circumvent Anderson localization, after a quench in the Hamiltonian parameters.
+The type of dynamics that occurs depends on whether or not the Fermi level of
+the initial state is near the energy of the delocalized states present in these
+models. If the Fermi level of the initial state is near the energy of the
+delocalized states, we observe an interesting slow logarithmic-like growth of
+the momentum-space entanglement entropy followed by an eventual saturation.
+Otherwise, the momentum-space entanglement entropy is found to rapidly
+saturate. We also find that the momentum-space entanglement spectrum reveals
+the presence of delocalized states in these models for long times after the
+quench and the many-body entanglement gap decays logarithmically in time when
+the Fermi level is near the energy of the delocalized states.",1909.05140v1
+2019-09-18,Probing parton saturation with forward $Z^0$-boson production at small transverse momentum in p+p and p+A collisions,"We calculate and compare the differential cross sections for forward
+$Z^0$-boson production at small transverse momentum, in proton-proton and
+proton-nucleus collisions, using both the collinear and dilute-dense
+factorization frameworks. In both cases, we implement a Sudakov resummation of
+the large logarithms generated by soft-gluon emissions, which is essential in
+order to describe the transverse momentum distribution of forward $Z^0$ bosons
+measured at the Tevatron and the LHC. We further compute the nuclear
+modification factor in the dilute-dense framework, hoping to single out signals
+of saturation effects at small values of $x$. Our predictions are compared with
+those obtained in the collinear factorization framework, using two different
+nuclear parton distribution functions.",1909.08572v2
+2019-09-19,Extremal rays of the embedded subgroup saturation cone,"We examine the extremal rays of the cone of dominant weights $(\mu,
+\widehat\mu)$ for groups $G\subseteq \widehat G$ for which there exists $N
+\gg0$ such that $$ \left(V(N\mu)\otimes V(N\widehat \mu)\right)^G\ne (0). $$ We
+exhibit formulas for a class of rays (""type I"") on any regular face of the
+cone. These rays are identified thanks to a generalization of Fulton's
+conjecture, which we prove along the way. We verify that the remaining rays
+(""type II"") on the face are the images of extremal rays for a smaller cone
+under a certain map, whose formula is given. A procedure is given for finding
+the rays of the cone not on any regular face. This is a generalization of the
+work of Belkale and Kiers on extremal rays for the saturated tensor cone; the
+specialization is given by $\widehat G = G\times G$ with the diagonal embedding
+of $G$. We include several examples to illustrate the formulas.",1909.09262v4
+2019-09-22,Model Reference Adaptive Control Allocation for Constrained Systems with Guaranteed Closed Loop Stability,"This paper proposes an adaptive control allocation approach for uncertain
+over-actuated systems with actuator saturation. The proposed method does not
+require uncertainty estimation or a persistent excitation assumption. Using the
+element-wise non-symmetric projection algorithm, the adaptive parameters are
+restricted to satisfy certain optimality conditions leading to overall closed
+loop system stability. Furthermore, a sliding mode controller with a
+time-varying sliding surface, working in tandem with the adaptive control
+allocation, is proposed to guarantee the outer loop stability and reference
+tracking in the presence of control allocation errors and disturbances.
+Simulation results are provided, where the Aerodata Model in Research
+Environment is used as an over-actuated system with actuator saturation, to
+demonstrate the effectiveness of the proposed method.",1909.10036v1
+2019-09-26,Synthesizing Structured CAD Models with Equality Saturation and Inverse Transformations,"Recent program synthesis techniques help users customize CAD models(e.g., for
+3D printing) by decompiling low-level triangle meshes to Constructive Solid
+Geometry (CSG) expressions. Without loops or functions, editing CSG can require
+many coordinated changes, and existing mesh decompilers use heuristics that can
+obfuscate high-level structure.
+  This paper proposes a second decompilation stage to robustly ""shrink""
+unstructured CSG expressions into more editable programs with map and fold
+operators. We present Szalinski, a tool that uses Equality Saturation with
+semantics-preserving CAD rewrites to efficiently search for smaller equivalent
+programs. Szalinski relies on inverse transformations, a novel way for solvers
+to speculatively add equivalences to an E-graph. We qualitatively evaluate
+Szalinski in case studies, show how it composes with an existing mesh
+decompiler, and demonstrate that Szalinski can shrink large models in seconds.",1909.12252v3
+2019-09-30,Multiplicity of the saturated special fiber ring of height three Gorenstein ideals,"Let $R$ be a polynomial ring over a field and $I \subset R$ be a Gorenstein
+ideal of height three that is minimally generated by homogeneous polynomials of
+the same degree. We compute the multiplicity of the saturated special fiber
+ring of $I$. The obtained formula depends only on the number of variables of
+$R$, the minimal number of generators of $I$, and the degree of the syzygies of
+$I$. Applying results from arXiv:1805.05180, we get a formula for the
+$j$-multiplicity of $I$ and an effective method to study a rational map
+determined by a minimal set of generators of $I$.",1909.13633v2
+2019-10-17,Entropic Bounds For Unitary Testers and Mutually Unbiased Unitary Bases,"We define the entropic bounds, i.e minimal uncertainty for pairs of unitary
+testers in distinguishing between unitary transformations not unlike the well
+known entropic bounds for observables. We show that in the case of specific
+sets of testers which pairwise saturate the trivial zero bound, the testers are
+all equivalent in the sense their statistics are the same. On the other hand,
+when maximal bounds are saturated by such sets of testers, the unitary
+operators would form unitary bases which are mutually unbiased. This resembles
+very much the role of mutually unbiased bases in maximizing the entropic bounds
+for observables. We show how such a bound can be useful in certain quantum
+cryptographic protocols.",1910.07665v3
+2019-10-21,Heavy quarkonium in saturated environment of high-multiplicity pp collisions,"High-multiplicity pp collisions exhibit features, traditionally associated
+with nuclear effects. Coherence motivates to treat high-multiplicity pp, pA and
+AA collisions on an equal footing. We rely on the phenomenological
+parametrization for mean multiplicities of light hadrons and J/psi, assuming
+their linear dependence on N_{coll} in pA collisions. The results of this
+approach underestimate the recently measured production rate of J/psi at very
+high hadronic multiplicities. The linear dependence of J/psi multiplicity on
+N_{coll} is subject to predicted nonlinear corrections, related to mutual
+boosting of the saturation scales in colliding dense parton clouds. A
+parameter-free calculation of the non-linear corrections allows to explain data
+for pT-integrated yield of J/psi at high hadronic multiplicities. Calculations
+are in a good accord with data binned in several pT-intervals as well. As was
+predicted, Upsilon and J/psi are equally suppressed at forward rapidities in pA
+collisions. Consequently, their fractional multiplicities at forward rapidities
+in pp collisions are equal as well, and their magnitude agrees with data.",1910.09682v2
+2019-10-25,Large impact parameter behaviour in the CGC/saturation approach: a new non-linear equation,"In this paper we propose a solution to the long standing problem in the
+CGC/saturation approach: the power-like fall off of the scattering amplitudes
+at large $b$. We propose a new non-linear equation, which takes into account
+random walks both in transverse momenta of the produced gluons and in their
+impact parameters. We demonstrate, that this equation is in accord with
+previous attempts to include the diffusion in impact parameters in the BFKL
+evolution equation. We show in the paper, that the solution to a new equation
+results in the exponential decrease of the scattering amplitude at large impact
+parameter, and in the restoration of the Froissart theorem.",1910.11662v2
+2019-10-28,Simple encoding of higher derivative gauge and gravity counterterms,"Invoking increasingly higher dimension operators to encode novel UV physics
+in effective gauge and gravity theories traditionally means working with
+increasingly more finicky and difficult expressions. We demonstrate that local
+higher derivative supersymmetric-compatible operators at four-points can be
+absorbed into simpler higher-derivative corrections to scalar theories, which
+generate the predictions of Yang-Mills and Gravity operators by suitable
+replacements of color-weights with color-dual kinematic weights as per
+Bern-Carrasco-Johansson double-copy. We exploit that Jacobi-satisfying
+representations can be composed out of other Jacobi-satisfying representations,
+and show that at four-points only a small number of building blocks are
+required to generate the predictions of higher-derivative operators. We find
+that this construction saturates the higher-derivative operators contributing
+to the four-point supersymmetric open and closed-string tree amplitudes,
+presenting a novel representation of the four-point supersymmetric open string
+making this structure manifest, as well as identifying the only four additional
+gauge-invariant building blocks required to saturate the four-point bosonic
+open string.",1910.12850v2
+2019-10-31,A Nonisothermal Thermodynamical Model Of Liquid-vapor Interaction With Metastability,"The paper concerns the construction of a compressible liquid-vapor relaxation
+model which is able to capture the metastable states of the non isothermal van
+der Waals model as well as saturation states. Starting from the Gibbs
+formalism, we propose a dynamical system which complies with the second law of
+thermodynamics. Numerical simulations illustrate the expected behaviour of
+metastable states: an initial metastable condition submitted to a certain
+perturbation may stay in the metastable state or reaches a saturation state.
+The dynamical system is then coupled to the dynamics of the compressible fluid
+using an Euler set of equations supplemented by convection equations on the
+fractions of volume, mass and energy of one of the phases.",1910.14525v1
+2019-11-16,A spatio-temporal multi-scale model for Geyer saturation point process: application to forest fire occurrences,"Because most natural phenomena exhibit dependence at multiple scales like
+locations of earthquakes or forest fire occurrences, spatio-temporal
+single-scale point process models are unrealistic in many applications. This
+motivates us to construct generalizations of classical Gibbs models. In this
+paper, we extend the Geyer saturation point process model to the
+spatio-temporal multi-scale framework. The simulation process is carried out
+through a birth-death Metropolis-Hastings algorithm. In a simulation study, we
+compare two common methods for statistical inference in Gibbs models: the
+pseudo-likelihood and logistic likelihood approaches that we tailor to this
+model. Finally, we illustrate this new model on forest fire occurrences
+modeling in Southern France.",1911.06999v2
+2019-11-18,Safe squeezing for antisparse coding,"Spreading the information over all coefficients of a representation is a
+desirable property in many applications such as digital communication or
+machine learning. This so-called antisparse representation can be obtained by
+solving a convex program involving an $\ell_\infty$-norm penalty combined with
+a quadratic discrepancy. In this paper, we propose a new methodology, dubbed
+safe squeezing, to accelerate the computation of antisparse representation. We
+describe a test that allows to detect saturated entries in the solution of the
+optimization problem. The contribution of these entries is compacted into a
+single vector, thus operating a form of dimensionality reduction. We propose
+two algorithms to solve the resulting lower dimensional problem. Numerical
+experiments show the effectiveness of the proposed method to detect the
+saturated components of the solution and illustrates the induced computational
+gains in the resolution of the antisparse problem.",1911.07508v2
+2019-11-30,Spatiotemporal mode-locking in lasers with large modal dispersion,"Dissipative nonlinear wave dynamics have been investigated extensively in
+mode-locked lasers with single transverse-mode, whereas there are few studies
+related to three-dimensional nonlinear dynamics within lasers. Recently,
+spatiotemporal mode-locking (STML) was proposed in lasers with small modal
+(i.e., transverse-mode) dispersion, which has been considered to be critical
+for achieving STML in those cavities because the small dispersion can be easily
+balanced. Here, we demonstrate that STML can also be achieved in multimode
+lasers with much larger modal dispersion, where we find that the intracavity
+saturable absorber plays an important role for counteracting the large modal
+dispersion. Furthermore, we observe a new STML phenomenon of passive nonlinear
+auto-selection of single-mode mode-locking, resulting from the interaction
+between spatiotemporal saturable absorption and spatial gain competition. Our
+work significantly broadens the design possibilities for useful STML lasers
+thus making them much more accessible for applications, and extends the
+explorable parameter space of the novel dissipative spatiotemporal nonlinear
+dynamics that can be achieved in these lasers.",1912.00161v2
+2019-12-03,Optimal management of impaired self-avoiding random walks for minimizing spatial coverage,"Self-avoidance is a common mechanism to improve the efficiency of a random
+walker for covering a spatial domain. However, how this efficiency decreases
+when self-avoidance is impaired or limited by other processes has remained
+largely unexplored. Here we use simulations to study the case when the
+self-avoiding signal left by a walker both (i) saturates after successive
+revisits to a site, and (ii) evaporates, or dissappears, after some
+characteristic time. We surprisingly reveal that the mean cover time becomes
+minimum for intermediate values of the evaporation time, leading to the
+existence of a nontrivial optimum management of the self-avoiding signal. We
+argue that this is a consequence of complex blocking effects caused by the
+interplay with the signal saturation and, remarkably, we show that the optimum
+becomes more and more significant as the domain size increases.",1912.04402v1
+2019-12-10,Feedback control of surface roughness in a one-dimensional KPZ growth process,"Control of generically scale-invariant systems, i.e., targeting specific
+cooperative features in non-linear stochastic interacting systems with many
+degrees of freedom subject to strong fluctuations and correlations that are
+characterized by power laws, remains an important open problem. We study the
+control of surface roughness during a growth process described by the
+Kardar--Parisi--Zhang (KPZ) equation in $(1+1)$ dimensions. We achieve the
+saturation of the mean surface roughness to a prescribed value using non-linear
+feedback control. Numerical integration is performed by means of the
+pseudospectral method, and the results are used to investigate the coupling
+effects of controlled (linear) and uncontrolled (non-linear) KPZ dynamics
+during the control process. While the intermediate time kinetics is governed by
+KPZ scaling, at later times a linear regime prevails, namely the relaxation
+towards the desired surface roughness. The temporal crossover region between
+these two distinct regimes displays intriguing scaling behavior that is
+characterized by non-trivial exponents and involves the number of controlled
+Fourier modes. Due to the control, the height probability distribution becomes
+negatively skewed, which affects the value of the saturation width.",1912.04789v1
+2019-12-10,Equilibria and Systemic Risk in Saturated Networks,"We undertake a fundamental study of network equilibria modeled as solutions
+of fixed point equations for monotone linear functions with saturation
+nonlinearities. The considered model extends one originally proposed to study
+systemic risk in networks of financial institutions interconnected by mutual
+obligations and is one of the simplest continuous models accounting for shock
+propagation phenomena and cascading failure effects. It also characterizes Nash
+equilibria of constrained quadratic network games with strategic
+complementarities. We first derive explicit expressions for network equilibria
+and prove necessary and sufficient conditions for their uniqueness encompassing
+and generalizing results available in the literature. Then, we study jump
+discontinuities of the network equilibria when the exogenous flows cross
+certain regions of measure 0 representable as graphs of continuous functions.
+Finally, we discuss some implications of our results in the two main motivating
+applications. In financial networks, this bifurcation phenomenon is responsible
+for how small shocks in the assets of a few nodes can trigger major aggregate
+losses to the system and cause the default of several agents. In constrained
+quadratic network games, it induces a blow-up behavior of the sensitivity of
+Nash equilibria with respect to the individual benefits.",1912.04815v2
+2019-12-11,Multi-gluon correlations and evidence of saturation from dijet measurements at an Electron Ion Collider,"We study inclusive and diffractive dijet production in electron-proton and
+electron-nucleus collisions within the Color Glass Condensate effective field
+theory. We compute dijet cross sections differentially in both mean dijet
+transverse momentum $\mathbf{P}$ and recoil momentum $\mathbf{\Delta}$, as well
+as the anisotropy in the relative angle between $\mathbf{P}$ and
+$\mathbf{\Delta}$. We use the nonlinear Gaussian approximation to compute
+multiparticle correlators for general small $x$ kinematics, employing running
+coupling Balitsky-Kovchegov evolution to determine the dipole amplitude at
+small $x$. Our results cover a much larger kinematic range than accessible in
+previous computations performed in the correlation limit approximation, where
+it is assumed that $|\mathbf{P}| \gg |\mathbf{\Delta}|$. We validate this
+approximation in its range of applicability and quantify its failure for
+$|\mathbf{P}| \lesssim |\mathbf{\Delta}|$. We also predict significant
+target-dependent deviations from the correlation limit approximation for
+$|\mathbf{P}| > |\mathbf{\Delta}|$ and $|\mathbf{P}| \lesssim Q_s$, which
+offers a straightforward test of gluon saturation and access to multi-gluon
+distributions at a future electron ion collider.",1912.05586v1
+2019-12-26,Exclusion Inside or at the Border of Conformal Bootstrap Continent,"How large can anomalous dimensions be in conformal field theories? What can
+we do to attain larger values? One attempt to obtain large anomalous dimensions
+efficiently is to use the Pauli exclusion principle. Certain operators
+constructed out of constituent fermions cannot form bound states without
+introducing non-trivial excitations. To assess the efficiency of this
+mechanism, we compare them with the numerical conformal bootstrap bound as well
+as with other interacting field theory examples. In two dimensions, it turns
+out to be the most efficient: it saturates the bound and is located at the
+(second) kink. In higher dimensions, it more or less saturates the bound but it
+may be slightly inside.",1912.11748v2
+2020-01-03,Fell bundles over quasi-lattice ordered groups and $\mathrm{C}^*$-algebras of compactly aligned product systems,"We define notions of semi-saturatedness and orthogonality for a Fell bundle
+over a quasi-lattice ordered group. We show that a compactly aligned product
+system of Hilbert bimodules can be naturally extended to a semi-saturated and
+orthogonal Fell bundle whenever it is simplifiable. Conversely, a
+semi-saturated and orthogonal Fell bundle is completely determined by the
+positive fibres and its cross sectional $\mathrm{C}^*$-algebra is isomorphic to
+a relative Cuntz--Pimsner algebra of a simplifiable product system of Hilbert
+bimodules. We show that this correspondence is part of an equivalence between
+bicategories and use this to generalise several results of Meyer and the author
+in the context of single correspondences. We apply functoriality for relative
+Cuntz--Pimsner algebras to study Morita equivalence between
+$\mathrm{C}^*$-algebras attached to compactly aligned product systems over
+Morita equivalent $\mathrm{C}^*$-algebras.",2001.00998v3
+2020-01-06,Stochastic Rounding: Algorithms and Hardware Accelerator,"Algorithms and a hardware accelerator for performing stochastic rounding (SR)
+are presented. The main goal is to augment the ARM M4F based multi-core
+processor SpiNNaker2 with a more flexible rounding functionality than is
+available in the ARM processor itself. The motivation of adding such an
+accelerator in hardware is based on our previous results showing improvements
+in numerical accuracy of ODE solvers in fixed-point arithmetic with SR,
+compared to standard round to nearest or bit truncation rounding modes.
+Furthermore, performing SR purely in software can be expensive, due to
+requirement of a pseudorandom number generator (PRNG), multiple masking and
+shifting instructions, and an addition operation. Also, saturation of the
+rounded values is included, since rounding is usually followed by saturation,
+which is especially important in fixed-point arithmetic due to a narrow dynamic
+range of representable values. The main intended use of the accelerator is to
+round fixed-point multiplier outputs, which are returned unrounded by the ARM
+processor in a wider fixed-point format than the arguments.",2001.01501v4
+2020-01-15,Ultrafast strong-field absorption in gapped graphene,"We study theoretically the strong-field absorption of an ultrafast optical
+pulse by a gapped graphene monolayer. At low field amplitudes, the absorbance
+in the pristine graphene is equal to the universal value of $2.3$ percent.
+Although the ultrafast optical absorption for low field amplitudes is
+independent of the polarization, linear or circular, of the applied optical
+pulse, for high field amplitudes, the absorption strongly depends on the pulse
+polarization. For a linearly polarized pulse, the optical absorbance is
+saturated at the value of $\approx 1.4$ percent for the pulse's amplitude of
+$\geq 0.4~\mathrm{V/\AA}$, but no such saturation is observed for a circularly
+polarized pulse. For the gapped graphene, the absorption of a linearly
+polarized pulse has a weak dependence on the bandgap, while for a circularly
+polarized pulse, the absorption is very sensitive to the bandgap. %Opening a
+bandgap in graphene by placing in on, for example, SiC substrate strongly
+modify the ultrafast absorption at small field amplitudes.",2001.05410v1
+2020-02-03,Chiral symmetry restoration and the thermal $f_0(500)$ state,"We analize the role played by the thermal $f_0(500)$ state or $\sigma$ in
+chiral symmetry restoration. The temperature corrections to the spectral
+properties of that state are included in order to provide a better description
+of the scalar susceptibility $\chi_S$ around the transition region. We use the
+Linear Sigma Model to establish the relation between $\chi_S$ and the $\sigma$
+propagator, which is used as a benchmark to test the approach where $\chi_S$ is
+saturated by the $f_0(500)$ inverse self-energy. Within such saturation
+approach, a peak for $\chi_S$ around the chiral transition is obtained when
+considering the $f_0(500)$ generated as a $\pi\pi$ scattering pole within
+Unitarized Chiral Perturbation Theory at finite temperature. That approach
+yields results complying with lattice data when the uncertainties of the
+low-energy constants are taken into account. Those uncertainties and the
+unitarization method are used to check the robustness of this approximation.
+Finally, we will discuss some recent results within the chiral lagrangian
+framework related to the topological susceptibility and its connection with
+chiral and $U_A(1)$ restoration.",2002.00796v1
+2020-02-06,Constraints and correlations of nuclear matter parameters from a density-dependent van der Waals model,"A recently proposed density-dependent van der Waals model, with only $4$ free
+parameters adjusted to fix binding energy, saturation density, symmetry energy,
+and incompressibility, is analyzed under symmetric and asymmetric nuclear
+matter constraints. In a previous paper, it was shown that this model is fully
+consistent with the constraints related to the binary neutron star merger event
+named GW170817 and reported by the LIGO and Virgo collaboration. Here, we show
+that it also describes satisfactorily the low and high-density regions of
+symmetric nuclear matter, with all the main constraints satisfied. We also
+found a linear correlation between the incompressibility and the skewness
+parameter, both at the saturation density and show how it relates to the
+crossing point presented in the incompressibility as a function of the density.
+In the asymmetric matter regime, other linear correlations are found, namely,
+the one between the symmetry energy ($J$) and its slope ($L_0$), and other one
+establishing the symmetry energy curvature as a function of the combination
+given by $3J-L_0$.",2002.02437v1
+2020-02-14,Limits of Transmit and Receive Array Gain in Massive MIMO,"In this paper, we consider the transmit and receive antenna array gain of
+massive MIMO systems. In particular, we look at their dependence on the number
+of antennas in the array, and the antenna spacing for uniform linear and
+uniform circular arrays. It is known that the transmit array gain saturates at
+a certain antenna spacing, but the receive array gain had not been considered.
+With our physically consistent analysis based on the Multiport Communication
+Theory, we show that the receive array gain does not saturate, but that there
+is a peak at a certain antenna spacing when there is no decoupling network at
+the receiver. As implementing a decoupling network for massive MIMO would be
+almost impossible, this is a reasonable assumption. Furthermore, we analyze how
+the array gain changes depending on the antenna spacing and the size of the
+antenna array and derive design recommendations.",2002.06107v2
+2020-02-24,Beyond Camera Motion Blur Removing: How to Handle Outliers in Deblurring,"Camera motion deblurring is an important low-level vision task for achieving
+better imaging quality. When a scene has outliers such as saturated pixels, the
+captured blurred image becomes more difficult to restore. In this paper, we
+propose a novel method to handle camera motion blur with outliers. We first
+propose an edge-aware scale-recurrent network (EASRN) to conduct deblurring.
+EASRN has a separate deblurring module that removes blur at multiple scales and
+an upsampling module that fuses different input scales. Then a salient edge
+detection network is proposed to supervise the training process and constraint
+the edges restoration. By simulating camera motion and adding various light
+sources, we can generate blurred images with saturation cutoff. Using the
+proposed data generation method, our network can learn to deal with outliers
+effectively. We evaluate our method on public test datasets including the GoPro
+dataset, Kohler's dataset and Lai's dataset. Both objective evaluation indexes
+and subjective visualization show that our method results in better deblurring
+quality than other state-of-the-art approaches.",2002.10201v3
+2020-02-24,Revised Estimates of Ocean Surface Drag in Strong Winds,"Air-sea drag governs the momentum transfer between the atmosphere and the
+ocean, and remains largely unknown in hurricane winds. We revisit the momentum
+budget and eddy-covariance methods to estimate the surface drag coefficient in
+the laboratory. Our drag estimates agree with field measurements in
+low-to-moderate winds, and previous laboratory measurements in hurricane-force
+winds. The drag coefficient saturates at $2.6 \times 10^{-3}$ and $U_{10}
+\approx 25\ m\ s^{-1}$, in agreement with previous laboratory results by
+Takagaki et al. (2012). During our analysis, we discovered an error in the
+original source code used by Donelan et al. (2004). We present the corrected
+data and describe the correction procedure. Although the correction to the data
+does not change the key finding of drag saturation in strong winds, its
+magnitude and wind speed threshold are significantly changed. Our findings
+emphasize the need for an updated and unified drag parameterization based on
+field and laboratory data.",2002.10590v2
+2020-02-26,Bandwidth-Optimized Parallel Algorithms for Sparse Matrix-Matrix Multiplication using Propagation Blocking,"Sparse matrix-matrix multiplication (SpGEMM) is a widely used kernel in
+various graph, scientific computing and machine learning algorithms. It is well
+known that SpGEMM is a memory-bound operation, and its peak performance is
+expected to be bound by the memory bandwidth. Yet, existing algorithms fail to
+saturate the memory bandwidth, resulting in suboptimal performance under the
+Roofline model. In this paper we characterize existing SpGEMM algorithms based
+on their memory access patterns and develop practical lower and upper bounds
+for SpGEMM performance. We then develop an SpGEMM algorithm based on outer
+product matrix multiplication. The newly developed algorithm called PB-SpGEMM
+saturates memory bandwidth by using the propagation blocking technique and by
+performing in-cache sorting and merging. For many practical matrices, PB-SpGEMM
+runs 20%-50% faster than the state-of-the-art heap and hash SpGEMM algorithms
+on modern multicore processors. Most importantly, PB-SpGEMM attains performance
+predicted by the Roofline model, and its performance remains stable with
+respect to matrix size and sparsity.",2002.11302v1
+2020-03-01,Anti-Windup Approximations of Oblique Projected Dynamics for Feedback-based Optimization,"In this paper we study how high-gain anti-windup schemes can be used to
+implement projected dynamical systems in control loops that are subject to
+saturation on a (possibly unknown) set of admissible inputs. This insight is
+especially useful for the design of autonomous optimization schemes that
+realize a closed-loop behavior which approximates a particular optimization
+algorithm (e.g., projected gradient or Newton descent) while requiring only
+limited model information. In our analysis we show that a saturated integral
+controller, augmented with an anti-windup scheme, gives rise to a perturbed
+projected dynamical system. This insight allows us to show uniform convergence
+and robust practical stability as the anti-windup gain goes to infinity.
+Moreover, for a special case encountered in autonomous optimization we show
+robust convergence, i.e., convergence to an optimal steady-state for finite
+gains. Apart from being particularly suited for online optimization of
+large-scale systems, such as power grids, these results are potentially useful
+for other control and optimization applications as they shed a new light on
+both anti-windup control and projected gradient systems.",2003.00478v1
+2020-03-01,Data analysis on Coronavirus spreading by macroscopic growth laws,"To evaluate the effectiveness of the containment on the epidemic spreading of
+the new Coronavirus disease 2019, we carry on an analysis of the time evolution
+of the infection in a selected number of different Countries, by considering
+well-known macroscopic growth laws, the Gompertz law, and the logistic law. We
+also propose here a generalization of Gompertz law. Our data analysis permits
+an evaluation of the maximum number of infected individuals. The daily data
+must be compared with the obtained fits, to verify if the spreading is under
+control. From our analysis it appears that the spreading reached saturation in
+China, due to the strong containment policy of the national government. In
+Singapore a large growth rate, recently observed, suggests the start of a new
+strong spreading. For South Korea and Italy, instead, the next data on new
+infections will be crucial to understand if the saturation will be reached for
+lower or higher numbers of infected individuals.",2003.00507v3
+2020-03-07,Efficient Nonnegative Tensor Factorization via Saturating Coordinate Descent,"With the advancements in computing technology and web-based applications,
+data is increasingly generated in multi-dimensional form. This data is usually
+sparse due to the presence of a large number of users and fewer user
+interactions. To deal with this, the Nonnegative Tensor Factorization (NTF)
+based methods have been widely used. However existing factorization algorithms
+are not suitable to process in all three conditions of size, density, and rank
+of the tensor. Consequently, their applicability becomes limited. In this
+paper, we propose a novel fast and efficient NTF algorithm using the element
+selection approach. We calculate the element importance using Lipschitz
+continuity and propose a saturation point based element selection method that
+chooses a set of elements column-wise for updating to solve the optimization
+problem. Empirical analysis reveals that the proposed algorithm is scalable in
+terms of tensor size, density, and rank in comparison to the relevant
+state-of-the-art algorithms.",2003.03572v1
+2020-03-09,How ice grows from premelting films and water droplets,"Close to the triple point, the surface of ice is covered by a thin liquid
+layer (so-called quasi-liquid layer) which crucially impacts growth and melting
+rates. Experimental probes cannot observe the growth processes below this
+layer, and classical models of growth by vapor deposition do not account for
+the formation of premelting films. Here, we develop a mesoscopic model of
+liquid-film mediated ice growth, and identify the various resulting growth
+regimes. At low saturation, freezing proceeds by terrace spreading, but the
+motion of the buried solid is conveyed through the liquid to the outer
+liquid-vapor interface. At higher saturations water droplets condense, a large
+crater forms below, and freezing proceeds undetectably beneath the droplet. Our
+approach is a general framework that naturally models freezing close to three
+phase coexistence and provides a first principle theory of ice growth and
+melting which may prove useful in the geosciences.",2003.04252v2
+2020-03-10,On the limit of a two-phase flow problem in thin porous media domains of Brinkman-type,"We study the process of two-phase flow in thin porous media domains of
+Brinkman-type. This is generally described by a model of coupled, mixed-type
+differential equations of fluids' saturation and pressure. To reduce the model
+complexity, different approaches that utilize the thin geometry of the domain
+have been suggested.
+  We focus on a reduced model that is formulated as a single nonlocal evolution
+equation of saturation. It is derived by applying standard asymptotic analysis
+to the dimensionless coupled model, however, a rigid mathematical derivation is
+still lacking. In this paper, we prove that the reduced model is the analytical
+limit of the coupled two-phase flow model as the geometrical parameter of
+domain's width--length ratio tends to zero. Precisely, we prove the convergence
+of weak solutions for the coupled model to a weak solution for the reduced
+model as the geometrical parameter approaches zero.",2003.04812v1
+2020-03-18,"Modeling Streaming Potential in Porous and Fractured Media, Description and Benefits of the Effective Excess Charge Density Approach","Self-potential signals can be generated by different sources and can be
+decomposed in various contributions. Streming potential is the contribution due
+to the water flux in the subsurface and is of particular interest in
+hydrogeophysics and reservoir characterization. Being able to estimate water
+fluxes in porous and fractured media using streaming potential data relies on
+our understanding of the electrokinetic coupling at the mineral-solution
+interface and our capacity to understand, model, and upscale this phenomenon.
+Two main approaches have been proposed to predict streaming potential
+generation in geological media. One of these approaches is based on determining
+the excess charge which is effectively dragged in the medium by water flow. In
+this chapter, we describe how to model the streaming potential by considering
+this effective excess charge density, how it can be defined, calculated and
+upscaled. We provide a short overview of the theoretical basis of this approach
+and we describe different applications to both water saturated and partially
+saturated soils and fractured media.",2003.08241v1
+2020-03-21,"Central exclusive $χ_{c,b}$ production at high energy colliders and gluon saturation approach","The central exclusive production of $\chi_{c}$ and $\chi_{b}$ at the LHC,
+RHIC and Tevatron energies is analyzed, using the recent unintegrated parton
+distribution (UGDs) functions available in the package TMDlib. Comparison with
+data is performed, which tests the underlying assumptions basing the
+theoretical approach and it can constrain the unintegrated gluon distribution
+function at the small-$x$ region. Predictions for LHC energies using recent
+UGDs based in CCFM formalism are provided. It is explored the underlying
+uncertainties on this production as the choice for the unintegrated gluon
+distribution and factorization scale is done. Moreover, based on the parton
+saturation model for the gluon distribution, analytical expressions for the
+rapidity distributions are proposed. The prompt production of $J/\psi+\gamma$
+and $\Upsilon+\gamma$ is computed for the first time for LHC energies within
+the very same formalism used for $\chi$ production.",2003.09552v2
+2020-03-26,Evaluation of radon adsorption efficiency values in xenon with activated carbon fibers,"The radioactive noble gas radon-222 ($\mathrm{^{222}Rn}$, or Rn) produced in
+the uranium series is a crucial background source in many underground
+experiments. We have estimated the adsorption property of Rn with Activated
+Carbon Fibers (ACFs) in air (Air), argon (Ar), and xenon (Xe) gas. In this
+study, we evaluated six ACFs, named A-7, A-10, A-15, A-20, A-25, and S-25,
+provided from UNITIKA Ltd. We measured intrinsic radioactivity of these ACF
+samples, and found A-20's radioactivity of the uranium series is
+$<5.5$~$\mathrm{mBq/kg}$ with $90\%$ confidence level. In Air and Ar gas, we
+found ACF A-15 has the adsorption efficiency of $1/10000$ reduction at maximum
+before saturation of Rn adsorption, and more than $97\%$ adsorption efficiency
+after the saturation. In Xe gas, we found ACF A-20 has the best Rn adsorption
+ability among tested ACFs. We also found S-25, A-25, and A-15 have similar Rn
+adsorption performance.",2003.11705v2
+2020-03-27,Characterization of the dissolution of water microdroplets in oil,"Water in oil emulsions have a wide range of applications from chemical
+technology to microfluidics, where the stability of water droplets is of
+paramount importance. Here using an accessible and easily reproducible
+experimental setup we describe and characterize the dissolution of water in
+oil, which renders nanoliter-sized droplets unstable, resulting in their
+shrinkage and disappearance in a time scale of hours. This process has
+applicability in creating miniature reactors for crystallization. We test
+multiple oils and their combinations with surfactants exhibiting widely
+different rates of dissolution. We derived simple analytical equations to
+determine the product of the diffusion coefficient and the relative saturation
+density of water in oil from the measured dissolution data. By measuring the
+moisture content of mineral and silicone oils with Karl Fischer titration
+before and after saturating them with water, we calculated the diffusion
+coefficient of water in these two oils",2003.12494v3
+2020-03-31,Investigating the diffractive gluon jet production in lepton-ion collisions,"We study the diffractive jet production in electron-ion collisions in the
+kinematical region where the mass $M_X$ of the diffractive final state is
+larger than $Q^2$. Based on parton saturation framework predictions are done
+for the kinematics of future or possible $eA$ machines as the EIC, LHeC,
+HE-LHeC and FCC-eA. We analyze the differential cross section as a function of
+jet (gluon) transverse momentum and from the experimental point of view this
+observable could be used to extract the saturation scale as a function of
+$x_{I\!\!P}$.",2003.13882v2
+2020-03-31,COVID-19 epidemic outcome predictions based on logistic fitting and estimation of its reliability,"Since the first outbreak of the COVID-19 epidemic at the end of 2019, data
+has been made available on the number of infections, deaths and recoveries for
+all countries of the World, and that data can be used for statistical analysis.
+The primary interest of this paper is how well the logistic equation can
+predict the outcome of COVID-19 epidemic in any regions of the World assuming
+that the methodology of the testing process, namely the data collection method
+and social behavior is not changing over the course of time. Besides the social
+relevance, this study has two scientific purposes: we investigate if a simple
+saturation model can describe the trend of the COVID-19 epidemic and if so, we
+would like to determine, from which point during the epidemic the fitting
+parameters provide reliable predictions. We also give estimations for the
+outcome of this epidemic in several countries based on the logistic model and
+the data available on 27 March, 2020. Based on the saturated cases in China, we
+have managed to find some criteria to judge the reliability of the predictions.",2003.14160v1
+2020-03-27,Saturation of the Infrared Absorption by Carbon Dioxide in the Atmosphere,"Based on new radiative transfer numerical evaluations, we reconsider an
+argument presented by Schack in 1972 that says that saturation of the
+absorption of infrared radiation by carbon dioxide in the atmosphere sets in as
+soon as the relative concentration of carbon dioxide exceeds a lower limit of
+approximately 300 ppm. We provide a concise brief and explicit representation
+of the greenhouse effect of the earth's atmosphere. We find an equilibrium
+climate sensitivity (temperature increase $\Delta T$ due to doubling of
+atmospheric $CO_2$ concentration) of $\Delta T \simeq 0.5 ^0C$. We elaborate on
+the consistency of these results on $\Delta T$ with results observationally
+obtained by satellite-based measurements of short-time radiation-flux versus
+surface-temperature changes.",2004.00708v2
+2020-04-02,Weak saturation numbers of complete bipartite graphs in the clique,"The notion of weak saturation was introduced by Bollob\'as in 1968. Let $F$
+and $H$ be graphs. A spanning subgraph $G \subseteq F$ is weakly
+$(F,H)$-saturated if it contains no copy of $H$ but there exists an ordering
+$e_1,\ldots,e_t$ of $E(F)\setminus E(G)$ such that for each $i \in [t]$, the
+graph $G \cup \{e_1,\ldots,e_i\}$ contains a copy $H'$ of $H$ such that $e_i
+\in H'$. Define $wsat(F,H)$ to be the minimum number of edges in a weakly
+$(F,H)$-saturated graph. In this paper, we prove for all $t \ge 2$ and $n \ge
+3t-3$, that $wsat(K_n,K_{t,t}) = (t-1)(n + 1 - t/2)$, and we determine the
+value of $wsat(K_n,K_{t-1,t})$ as well. For fixed $2 \le s < t$, we also obtain
+bounds on $wsat(K_n,K_{s,t})$ that are asymptotically tight.",2004.01289v2
+2020-04-08,Nuclear shadowing in deep inelastic scattering on nuclei at very small x,"Nuclear shadowing corrections to the structure functions of deep inelastic
+scattering on intermediate-mass nuclei are calculated at very small values of
+Bjorken x and small values of Q^2 (Q^2<5 Gev^2). The two-component approach
+developed in previous works of authors for a description of the nucleon
+structure functions of deep inelastic scattering is used. It is shown that the
+hard component of the nucleon structure functions that arises, in terms of the
+colour dipole model, from qq-pairs with a high transverse momentum, is almost
+not shadowed. It is shown that a change of the slope of the shadowing curve
+with a decrease of x depends, at small values of x, on the relative
+contribution of the hard component to the nucleon structure function (this
+contribution is a function of x and Q^2) and on a size of gluon saturation
+effects. It is shown that an accounting for saturation effects becomes
+essential for predictions of shadowing at x<10^-4, depending on a value of Q^2.
+Results of numerical calculations of nuclear shadowing for several nuclei are
+compared with available data of the E665 and the NMC collaborations.",2004.03843v1
+2020-04-15,Crossed products of dual operator spaces and a characterization of groups with the approximation property,"Let $ G $ be a locally compact group. We study the categories of $
+L^{\infty}(G) $-comodules and $ L(G) $-comodules in the setting of dual
+operator spaces and the associated crossed products. It is proved that every $
+L^{\infty}(G) $-comodule is non-degenerate and saturated, whereas every $ L(G)
+$-comodule is non-degenerate if and only if every $ L(G) $-comodule is
+saturated if and only if $ G $ has the approximation property in the sense of
+Haagerup and Kraus [14]. This allows us to extend known results from the
+duality theory of crossed products of von Neumann algebras (such as
+Takesaki-duality and the Digernes-Takesaki theorem) to the recent theory of
+crossed products of dual operator spaces. As applications, we obtain a
+characterization of groups with the approximation property in terms of the
+related crossed products improving a recent result of Crann and Neufang [9] and
+we generalize a theorem of Anoussis, Katavolos and Todorov [2] providing a less
+technical proof of it. Furthermore, this approach provides an answer to a
+question raised by the authors in [2].",2004.07169v1
+2020-04-20,S3Library: Automatically Eliminating C/C++ Buffer Overflow using Compatible Safer Libraries,"Annex K of C11, bounds-checking interfaces, recently introduced a set of
+alternative functions to mitigate buffer overflows, primarily those caused by
+string/memory functions. However, poor compatibility limits their adoption.
+Failure oblivious computing can eliminate the possibility that an attacker can
+exploit memory errors to corrupt the address space and significantly increase
+the availability of systems.
+  In this paper, we present S3Library (Saturation-Memory-Access Safer String
+Library), which is compatible with the standard C library in terms of function
+signature. Our technique automatically replaces unsafe deprecated memory/string
+functions with safer versions that perform bounds checking and eliminate buffer
+overflows via boundless memory. S3Library employs MinFat, a very compact
+pointer representation following the Less is More principle, to encode metadata
+into unused upper bits within pointers. In addition, S3Library utilizes
+Saturation Memory Access to eliminate illegal memory accesses into boundless
+padding area. Even if an out-of-bounds access is made, the fault program will
+not be interrupted. We implement our scheme within the LLVM framework on X86-64
+and evaluate our approach on correctness, security, runtime performance and
+availability.",2004.09062v1
+2020-04-25,Scale-free Linear Observer-based Protocol Design for Global Regulated State Synchronization of Homogeneous Multi-agent Systems with Non-introspective Agents Subject to Input Saturation,"This paper studies global regulated state synchronization of homogeneous
+networks of non-introspective agents in presence of input saturation. We
+identify three classes of agent models which are neutrally stable,
+double-integrator, and mixed of double-integrator, single-integrator and
+neutrally stable dynamics. A \textit{scale-free linear observer-based} protocol
+design methodology is developed based on localized information exchange among
+neighbors where the reference trajectory is given by a so-called exosystem
+which is assumed to be globally reachable. Our protocols do not need any
+knowledge about the communication network topology and the spectrum of
+associated Laplacian matrix. Moreover, the proposed protocol is scalable and is
+designed based on only knowledge of agent models and achieves synchronization
+for any communication graph with arbitrary number of agents.",2004.13479v1
+2020-04-28,Nuclear Symmetry Energy and Neutron Skin Thickness of $^{208}Pb $ using a finite range effective interaction,"We use a finite range simple effective interaction to construct nuclear
+equations of state for the study of the density dependence of the nuclear
+symmetry energy. The EoSs provide good descriptions of the nuclear symmetry
+energy at a subsaturation density $\rho_c=0.11$ fm$^{-3}$ and at a density
+around two times the saturation density $\rho_0$. We obtain a correlation
+between the neutron skin thickness in $^{208}$Pb and the density slope
+parameter at the subsaturation density. A linear relation is obtained between
+the neutron skin thickness and the parameter
+$\beta^{\prime}=\frac{L(\rho_c)}{3E_s(\rho_0)}$, where $E_s(\rho_0)$ and
+$L(\rho_c)$ are respectively the nuclear symmetry energy at saturation density
+and the density slope parameter at the subsaturation density.",2004.14205v2
+2020-05-03,BAlN alloy for enhanced two-dimensional electron gas characteristics of GaN-based high electron mobility transistor,"The emerging wide bandgap BAlN alloys have potentials for improved
+III-nitride power devices including high electron mobility transistor (HEMT).
+Yet few relevant studies have been carried. In this work, we have investigated
+the use of the B0.14Al0.86N alloy as part or entirety of the interlayer between
+the GaN buffer and the AlGaN barrier in the conventional GaN-based high
+electron mobility transistor (HEMT). The numerical results show considerable
+improvement of the two-dimensional electron gas (2DEG) concentration with small
+2DEG leakage into the ternary layer by replacing the conventional AlN
+interlayer by either the B0.14Al0.86N interlayer or the B0.14Al0.86N/AlN hybrid
+interlayer. Consequently, the transfer characteristics can be improved. The
+saturation current can be enhanced as well. For instance, the saturation
+currents for HEMTs with the 0.5 nm B0.14Al0.86N/0.5 nm AlN hybrid interlayer
+and the 1 nm B0.14Al0.86N interlayer are 5.8% and 2.2% higher than that for the
+AlN interlayer when VGS-Vth= +3 V.",2005.01161v1
+2020-05-05,Rayleigh-Bénard instability of an Ellis fluid saturating a porous medium,"Unlike the power-law model, the Ellis model describes the apparent viscosity
+of a shear-thinning fluid with no singularity in the limit of a vanishingly
+small shear stress. In particular, this model matches the Newtonian behaviour
+when the shear stresses are very small. The emergence of the Rayleigh-B\'enard
+instability is studied when a horizontal pressure gradient, yielding a basic
+throughflow, is prescribed in a horizontal porous layer. The threshold
+conditions for the linear instability of this system are obtained both
+analytically and numerically. In the case of a negligible flow rate, the onset
+of the instability occurs for the same parametric conditions reported in the
+literature for a Newtonian fluid saturating a porous medium. On the other hand,
+when high flow rates are considered, a negligibly small temperature difference
+imposed across the horizontal boundaries is sufficient to trigger the
+convective instability.",2005.02021v1
+2020-05-15,Investigating the inclusive transverse spectra in high-energy $pp$ collisions in the context of geometric scaling framework,"The presence of geometric scaling within the $p_T$ spectra of produced
+hadrons at high energy $pp$ collisions using small-$x$ $k_T$-factorization is
+investigated. It is proposed a phenomenological parameterization for the
+unintegrated gluon distribution in the scaling range which reproduces the
+features of the differential cross section both in the saturated and dilute
+perturbative QCD regimes. As the saturation scale acts as an effective
+regulator of the infrared region (IR), the extension of the model to quantities
+usually associated to soft physics is studied. The approach is applied to
+compute the average $p_T$ and the rapidity distribution of produced gluons at
+high energies.",2005.07760v2
+2020-05-21,The Rise of Cosmological Complexity: Saturation of Growth and Chaos,"We compute the circuit complexity of scalar curvature perturbations on FLRW
+cosmological backgrounds with fixed equation of state $w$ using the language of
+squeezed vacuum states. Backgrounds that are accelerating and expanding, or
+decelerating and contracting, exhibit features consistent with chaotic
+behavior, including linearly growing complexity. Remarkably, we uncover a bound
+on the growth of complexity for both expanding and contracting backgrounds
+$\lambda \leq \sqrt{2} \ |H|$, similar to other bounds proposed independently
+in the literature. The bound is saturated for expanding backgrounds with an
+equation of state more negative than $w = -5/3$, and for contracting
+backgrounds with an equation of state larger than $w = 1$. For expanding
+backgrounds that preserve the null energy condition, de Sitter space has the
+largest rate of growth of complexity (identified as the Lyapunov exponent), and
+we find a scrambling time that is similar to other estimates up to order one
+factors.",2005.10854v1
+2020-06-04,Diffusion and operator entanglement spreading,"Understanding the spreading of the operator space entanglement entropy
+($OSEE$) is key in order to explore out-of-equilibrium quantum many-body
+systems. Here we argue that for integrable models the dynamics of the $OSEE$ is
+related to the diffusion of the underlying quasiparticles. We derive the
+logarithmic bound $1/2\ln(t)$ for the $OSEE$ of some simple, i.e., low-rank,
+diagonal local operators. We numerically check that the bound is saturated in
+the rule $54$ chain, which is representative of interacting integrable systems.
+Remarkably, the same bound is saturated in the spin-1/2 Heisenberg $XXZ$ chain.
+Away from the isotropic point and from the free-fermion point, the $OSEE$ grows
+as $1/2\ln(t)$, irrespective of the chain anisotropy, suggesting universality.
+Finally, we discuss the effect of integrability breaking. We show that strong
+finite-time effects are present, which prevent from probing the asymptotic
+behavior of the $OSEE$.",2006.02788v2
+2020-06-11,Pore Scale Study of Gas Bubble Nucleation and Migration in Porous Media,"The behavior of gas bubbles in porous media includes bubble nucleation and
+growth, migration, coalescence, and trapping. These processes are significantly
+affected by the pore-scale characteristics and heterogeneity of the sediment.
+In this study, experiments are performed using a microfluidic chip in which
+different gas bubble behavior mechanisms are observed. Based on the microscale
+experiments, eight major gas bubble behavior mechanisms are identified. In
+addition, a mesoscale experiment is designed and performed to study the impacts
+of soil layering and heterogeneity on the formation and distribution of
+biogenic gas generation via denitrification. The results show that the
+pore-scale characteristics of soil significantly affect the distribution and
+migration pattern of biogenic gas bubbles. As a result, the water saturation
+may vary locally between fully saturated (in fine sand), to about 80% in zones
+where the gas is allowed to migrate freely (coarse sand), to even close to 0%
+in the zone where the gas gets trapped under layers with higher air entry
+value.",2006.06851v1
+2020-06-15,Analytic insights on the information content of new observables,"Uncertainty quantification has emerged as a rapidly growing field in nuclear
+science. Theoretical predictions of physical observables often involve
+extrapolations to regions that are poorly constrained by laboratory experiments
+and astrophysical observations. Without properly quantified theoretical errors,
+such model predictions are of limited value. Also, one often deals with
+theoretical constructs that involve fundamental quantities that are not
+accessible to experiment or observation. Particularly relevant in this context
+is the pressure of pure neutron matter. In this contribution we develop an
+analytic framework to answer the question of ""How can new data reduce
+uncertainties of current theoretical models?"" [P.-G. Reinhard and W.
+Nazarewicz, Phys. Rev. C81, 051303(R) (2010)]. Simple and insightful
+expressions are obtained to quantify the impact of one or two new observables
+on theoretical uncertainties in two critical quantities: the slope of the
+symmetry energy at saturation density and the pressure of pure neutron matter
+at twice nuclear matter saturation density.",2006.08405v1
+2020-06-18,Stability of Internal States in Recurrent Neural Networks Trained on Regular Languages,"We provide an empirical study of the stability of recurrent neural networks
+trained to recognize regular languages. When a small amount of noise is
+introduced into the activation function, the neurons in the recurrent layer
+tend to saturate in order to compensate the variability. In this saturated
+regime, analysis of the network activation shows a set of clusters that
+resemble discrete states in a finite state machine. We show that transitions
+between these states in response to input symbols are deterministic and stable.
+The networks display a stable behavior for arbitrarily long strings, and when
+random perturbations are applied to any of the states, they are able to recover
+and their evolution converges to the original clusters. This observation
+reinforces the interpretation of the networks as finite automata, with neurons
+or groups of neurons coding specific and meaningful input patterns.",2006.10828v1
+2020-06-25,Thermal radiation and inclusive production in the running coupling $k_T$ -- factorization approach,"The characteristics of the thermal radiation are investigated using a two -
+component model, with the hard component being described by the Color Glass
+Condensate formalism. The inclusive transverse momentum spectra of charged
+hadrons produced in proton - proton and proton - nucleus collisions at LHC
+energies and large - $p_T$ are estimated using the running coupling $k_T$ -
+factorization formula and the solution of the Balitsky - Kovchegov equation.
+Our results indicate that the thermal term is necessary to describe the
+experimental data and that the effective thermal temperature has an energy
+dependence similar to the saturation scale. We demonstrate that the enhancement
+of the thermal temperature in $pPb$ collisions is consistent with that
+predicted by the saturation scale.",2006.14335v1
+2020-06-25,Quantumized Microwave Detection Based on $Λ$-Type Three-level Superconducting System: HMM Modeling and Performance Prediction,"We adopt artificial $\Lambda$-type three-level system with superconducting
+devices for microwave signal detection, where the signal intensity reaches the
+level of discrete photons instead of continuous waveform. Based on the state
+transition principles of the three-level system, we propose a statistical model
+for microwave signal detection. Moreover, we investigate the achievable
+transmission rate and signal detection based on the statistical model. It is
+predicted that the proposed detection can achieve significantly higher
+sensitivity compared with the currently deployed 4G/5G communication system. We
+further characterize the received signal considering the saturation phonomenon,
+which reveals negligible performance degradation caused by saturation under
+weak received power regime.",2006.14497v3
+2020-06-28,Recursive Analytic Solution of Nonlinear Optimal Regulators,"The paper develops an optimal regulator for a general class of multi-input
+affine nonlinear systems minimizing a nonlinear cost functional with infinite
+horizon. The cost functional is general enough to enforce saturation limits on
+the control input if desired. An efficient algorithm utilizing tensor algebra
+is employed to compute the tensor coefficients of the Taylor series expansion
+of the value function (i.e., optimal cost-to-go). The tensor coefficients are
+found by solving a set of nonlinear matrix equations recursively generalizing
+the well-known linear quadratic solution. The resulting solution generates the
+optimal controller as a nonlinear function of the state vector up to a
+prescribed truncation order. Moreover, a complete convergence of the computed
+solution together with an estimation of its applicability domain are provided
+to further guide the user. The algorithm's computational complexity is shown to
+grow only polynomially with respect to the series order. Finally, several
+nonlinear examples including some with input saturation are presented to
+demonstrate the efficacy of the algorithm to generate high order Taylor series
+solution of the optimal controller.",2006.15685v1
+2020-06-29,Bright high-purity quantum emitters in aluminium nitride integrated photonics,"Solid-state quantum emitters (QEs) are fundamental in photonic-based quantum
+information processing. There is strong interest to develop high-quality QEs in
+III-nitride semiconductors because of their sophisticated manufacturing driven
+by large and growing applications in optoelectronics, high voltage power
+transistors, and microwave amplifiers. Here, we report the generation and
+direct integration of QEs in an aluminium nitride-based photonic integrated
+circuit platform. For individual waveguide-integrated QEs, we measure an
+off-chip count rate exceeding $6 \times 10^{4}$ counts per second (cps)
+(saturation rate > $8.6 \times 10^{4}$ cps). In an unpatterned thin-film
+sample, we measure antibunching with $g^{(2)}(0) \sim 0.05$ and photon count
+rates exceeding $8 \times 10^{5}$ cps (saturation rate > $1 \times 10^{6}$
+cps). Although spin and detailed optical linewidth measurements are left for
+future work, these results already show the potential for high-quality QEs
+monolithically integrated in a wide range of III-nitride device technologies
+that would enable new quantum device opportunities and industrial scalability.",2006.16276v1
+2020-07-09,Formation of dispersive shock waves in a saturable nonlinear medium,"We use the Gurevich-Pitaevskii approach based on the Whitham averaging method
+for studying the formation of dispersive shock waves in an intense light pulse
+propagating through a saturable nonlinear medium. Although the Whitham
+modulation equations cannot be diagonalized in this case, the main
+characteristics of the dispersive shock can be derived by means of an analysis
+of the properties of these equations at the boundaries of the shock. Our
+approach generalizes a previous analysis of step-like initial intensity
+distributions to a more realistic type of initial light pulse and makes it
+possible to determine, in a setting of experimental interest, the value of
+measurable quantities such as the wave-breaking time or the position and light
+intensity of the shock edges.",2007.05087v1
+2020-07-12,Verifying the upper bound on the speed of scrambling with the analogue Hawking radiation of trapped ions,"A general bound on the Lyapunov exponent of a quantum system is given by
+$\lambda_L\leq2\pi\,T/\hbar$, where $T$ is the system temperature, as
+established by Maldacena, Shenker, and Stanford (MSS). This upper bound is
+saturated when the system under consideration is the exact holographic dual of
+a black hole. It has also been shown that an inverted harmonic oscillator (IHO)
+may exhibit the behavior of thermal energy emission, in close analogy to the
+Hawking radiation emitted by black holes. We demonstrate that the Lyapunov
+exponent of the IHO indeed saturates the MSS bound, with an effective
+temperature equal to the analogue black hole radiation temperature, and propose
+using a trapped ion as a physical implementation of the IHO. We derive the
+corresponding out-of-time-ordered correlation function (OTOC) diagnosing
+quantum chaos, and theoretically show, for an experimentally realizable setup,
+that the effective temperature of the trapped-ion-IHO matches the upper MSS
+bound for the speed of scrambling.",2007.05949v1
+2020-07-13,Non-linear equation in the re-summed next-to-leading order of perturbative QCD: the leading twist approximation,"In this paper, we use the re-summation procedure, suggested in
+Refs.\cite{DIMST,SALAM,SALAM1,SALAM2}, to fix the BFKL kernel in the NLO.
+However, we suggest a different way to introduce th non-linear corrections in
+the saturation region, which is based on the leading twist non-linear equation.
+In the kinematic region:$\tau\,\equiv\,r^2 Q^2_s(Y)\,\leq\,1$ , where $r$
+denotes the size of the dipole, $Y$ its rapidity and $Q_s$ the saturation
+scale, we found that the re-summation contributes mostly to the leading twist
+of the BFKL equation. Assuming that the scattering amplitude is small, we
+suggest using the linear evolution equation in this region. For $\tau \,>\,1$
+we are dealing with the re-summation of $\Lb \bas \,\ln \tau\Rb^n$ and other
+corrections in NLO approximation for the leading twist.We find the BFKL kernel
+in this kinematic region and write the non-linear equation, which we solve
+analytically. We believe the new equation could be a basis for a consistent
+phenomenology based on the CGC approach.",2007.06214v2
+2020-07-18,Modeling lasers and saturable absorbers via multilevel atomic media in the Meep FDTD software: Theory and implementation,"This technical note describes the physical model, numerical implementation,
+and validation of multilevel atomic media for lasers and saturable absorbers in
+Meep: a free/open-source finite-difference time-domain (FDTD) software package
+for electromagnetics simulation. Simulating multilevel media in the time domain
+involves coupling rate equations for the populations of electronic energy
+levels with Maxwell's equations via a generalization of the Maxwell--Bloch
+equations. We describe the underlying equations and their implementation using
+a second-order discretization scheme, and also demonstrate their equivalence to
+a quantum density-matrix model. The Meep implementation is validated using a
+separate FDTD density-matrix model as well as a frequency-domain solver based
+on steady-state ab-initio laser theory (SALT).",2007.09329v3
+2020-07-19,"QHSL: a quantum hue, saturation, and lightness color model","Quantum image processing employs quantum computing to capture, manipulate,
+and recover images in various formats. This requires representations of encoded
+images using the quantum mechanical composition of any potential computing
+hardware. In this study, a quantum hue, saturation, and lightness (QHSL) color
+model is proposed to organize and conceptualize color-assignment attributes
+using the properties of quantum mechanics (i.e., entanglement and parallelism).
+The proposed color model is used to define representations of a two-dimensional
+QHSL image and investigate its data storage, chromatic transformation, and
+pseudocolor applications. The QHSL representation is introduced for the
+production of quantum images using triple perceptually relevant components. The
+efficient use of QHSL images is further explored for applications in the fields
+of computer vision and image analysis.",2007.09659v1
+2020-07-30,Maximally self-interacting dark matter: models and predictions,"We study self-interacting dark matter (SIDM) scenarios, where the $s$-wave
+self-scattering cross section almost saturates the Unitarity bound. Such
+self-scattering cross sections are singly parameterized by the dark matter
+mass, and are featured by strong velocity dependence in a wide range of
+velocities. They may be indicated by observations of dark matter halos in a
+wide range of masses, from Milky Way's dwarf spheroidal galaxies to galaxy
+clusters. We pin down the model parameters that saturates the Unitarity bound
+in well-motivated SIDM models: the gauged $L_{\mu} - L_{\tau}$ model and
+composite asymmetric dark matter model. We discuss implications and predictions
+of such model parameters for cosmology like the $H_{0}$ tension and dark-matter
+direct-detection experiments, and particle phenomenology like the beam-dump
+experiments.",2007.15522v2
+2020-08-04,Towards mitigation of apparent tension between nuclear physics and astrophysical observations by improved modeling of neutron star matter,"Observations of neutron stars (NSs) by the LIGO-Virgo and NICER
+collaborations have provided reasonably precise measurements of their various
+macroscopic properties. In this paper, we employ a Bayesian framework to
+combine them and place improved joint constraints on the properties of NS
+equation of state (EoS). We use a hybrid EoS formulation that employs a
+parabolic expansion-based nuclear empirical parameterization around the nuclear
+saturation density augmented by a generic 3-segment piecewise polytrope model
+at higher densities. Within the $90 \%$ credible level this parameterization
+predicts $R_{1.4} = 12.57_{-0.92}^{+0.73}$ km and $\Lambda_{1.4} =
+550_{-225}^{+223}$ for the radius and dimensionless tidal deformability,
+respectively, of a $1.4 M_{\odot}$ NS. Finally, we show how the construction of
+the full NS EoS based solely on the nuclear empirical parameters at saturation
+density leads to certain tension with the astrophysical data, and how the
+hybrid approach provides a resolution to it.",2008.01582v2
+2020-08-07,Fast Identification of Saturated Cut-sets using Graph Search Techniques,"When multiple outages occur in rapid succession, it is important to know
+quickly if the power transfer capability of different interconnections (or
+cut-sets) of the power network are limited. The algorithm developed in this
+paper identifies such limited cut-sets very fast, thereby enhancing the
+real-time situational awareness of power system operators. The significance of
+the proposed approach is described using the IEEE 39-bus test system, while its
+computational benefits are demonstrated using relatively large test-cases
+containing thousands of buses. The results indicate that the proposed network
+analysis can estimate the impact of an outage on any cut-set of the system and
+screen out the cut-set that gets saturated by the largest margin, very quickly.",2008.02951v1
+2020-08-05,Modeling of relative permeabilities including dynamic wettability transition zones,"Wettability is a pore-scale property that impacts the relative movement and
+distribution of fluids in a porous medium. There are reservoir fluids that
+provoke the surface within pores to undergo a wettability change. This
+wettability change, in turn, alters the dynamics of relative permeabilities at
+the Darcy scale. Thus, modeling the impact of wettability change in relative
+permeabilities is essential to understand fluids interaction in porous media.
+In this study, we include time-dependent wettability change into the relative
+permeability--saturation relation by modifying the existing relative
+permeability function. To do so, we assume the wettability change is
+represented by the sorption-based model that is exposure time and chemistry
+dependent. This pore-scale model is then coupled with a triangular
+bundle-of-tubes model to simulate exposure time-dependent relative
+permeabilities data. The simulated data is used to characterize and quantify
+the wettability dynamics in the relative permeability--saturation curves. This
+study further shows the importance of accurate prediction of the relative
+permeability in a dynamically altering porous medium.",2008.06572v1
+2020-08-17,Saturation of the inverse cascade in surface gravity wave turbulence,"We report on the observation of surface gravity wave turbulence at scales
+larger than the forcing ones in a large basin. In addition to the downscale
+transfer usually reported in gravity wave turbulence, an upscale transfer is
+observed, interpreted as the inverse cascade of weak turbulence theory. A
+steady state is achieved when the inverse cascade reaches a scale in between
+the forcing wavelength and the basin size, but far from the latter. This
+inverse cascade saturation, which depends on the wave steepness, is probably
+due to the emergence of nonlinear dissipative structures such as sharp-crested
+waves.",2008.08467v1
+2020-08-21,Enhanced Tensor Polarization in Solid-State Targets,"We report measurements of enhanced tensor polarization on solid-state
+targets. The results here represent an increase in tensor polarization over
+that previously achieved in high energy and nuclear scattering experiments that
+focused on the measurement of tensor polarized observables. Enhancement
+techniques are used which require RF produced close to the Larmor frequency of
+the target spins and use selective semi-saturation resulting from two sources
+of irradiation, microwave for the DNP process and the additional RF used to
+manipulate the population of the energy levels in the target material. The spin
+dynamics of the solid target are used to align the spins enhancing the ensemble
+average to improve the figure of merit of the scattering experiment. Target
+rotation at an optimized rate can lead to additional enhancement by applying
+selective semi-saturation in polycrystalline materials that possess a Pake
+doublet in their NMR signal.",2008.09515v1
+2020-08-26,"Quantum walks with quantum chaotic coins: Of the Loschmidt echo, classical limit and thermalization","Coined discrete-time quantum walks are studied using simple deterministic
+dynamical systems as coins whose classical limit can range from being
+integrable to chaotic. It is shown that a Loschmidt echo like fidelity plays a
+central role and when the coin is chaotic this is approximately the
+characteristic function of a classical random walker. Thus the classical
+binomial distribution arises as a limit of the quantum walk and the walker
+exhibits diffusive growth before eventually becoming ballistic. The coin-walker
+entanglement growth is shown to be logarithmic in time as in the case of
+many-body localization and coupled kicked rotors, and saturates to a value that
+depends on the relative coin and walker space dimensions. In a coin dominated
+scenario, the chaos can thermalize the quantum walk to typical random states
+such that the entanglement saturates at the Haar averaged Page value, unlike in
+a walker dominated case when atypical states seem to be produced.",2008.11318v4
+2020-08-31,A fractal model for the electrical conductivity of water-saturated porous media during mineral precipitation-dissolution processes,"Precipitation and dissolution are prime processes in carbonate rocks and
+being able to monitor them is of major importance for aquifer and reservoir
+exploitation or environmental studies. Electrical conductivity is a physical
+property sensitive both to transport phenomena of porous media and to
+dissolution and precipitation processes. However, its quantitative use depends
+on the effectiveness of the petrophysical relationship to relate the electrical
+conductivity to hydrological properties of interest. In this work, we develop a
+new physically-based model to estimate the electrical conductivity by upscaling
+a microstructural description of water-saturated fractal porous media. This
+model is successfully compared to published data from both unconsolidated and
+consolidated samples, or during precipitation and dissolution numerical
+experiments. For the latter, we show that the permeability can be linked to the
+predicted electrical conductivity.",2008.13673v1
+2020-09-02,Resonance overlap and non-linear features of the beam-plasma system,"The beam-plasma instability can be addressed as a reduced model in several
+contexts of plasma physics, from space to fusion plasma. In this paper, we
+review and refine some non-linear features of this model. Specifically, by
+analyzing the dependence of the non-linear velocity spread as a function of the
+linear growth rate, we discuss the effective size of the resonance in view of
+its role in the spectral overlap at saturation. The relevance of this
+characterization relies on the necessity of a quantitative determination of the
+overlap degree to discriminate among different transport regimes of the self
+consistent dynamics. The analysis is enriched with a study of the phase-space
+dynamics by means of the Lagrangian Coherent Structure technique, in order to
+define the transport barriers of the system describing the relevant features of
+the overlap process. Finally, we discuss relevant features related to the mode
+saturation levels.",2009.01629v1
+2020-09-07,Handling actuator magnitude and rate saturation in uncertain over-actuated systems: A modified projection algorithm approach,"This paper proposes a projection algorithm which can be employed to bound
+actuator signals, in terms of both magnitude and rate, for uncertain systems
+with redundant actuators. The investigated closed loop control system is
+assumed to contain an adaptive control allocator to distribute the total
+control input among actuators. Although conventional control allocation methods
+can handle actuator rate and magnitude constraints, they cannot consider
+actuator uncertainty. On the other hand, adaptive allocators manage uncertainty
+and actuator magnitude limits. The proposed projection algorithm enables
+adaptive control allocators to handle both magnitude and rate saturation
+constraints. A mathematically rigorous analysis is provided to show that with
+the help of the proposed projection algorithm, the performance of the adaptive
+control allocator can be guaranteed, in terms of error bounds. Simulation
+results are presented, where the Aero-Data Model In Research Environment
+(ADMIRE) is used as an over-actuated system, to demonstrate the effectiveness
+of the proposed method.",2009.03024v1
+2020-09-09,Guessing Numbers and Extremal Graph Theory,"For a given number of colors, $s$, the guessing number of a graph is the
+(base $s$) logarithm of the cardinality of the largest family of colorings of
+the vertex set of the graph such that the color of each vertex can be
+determined from the colors of the vertices in its neighborhood. This quantity
+is related to problems in network coding, circuit complexity and graph entropy.
+We study the guessing number of graphs as a graph property in the context of
+classic extremal questions, and its relationship to the forbidden subgraph
+property. We find the extremal number with respect to the property of having
+guessing number $\leq a$, for fixed $a$. Furthermore, we find an upper bound on
+the saturation number for this property, and a method to construct further
+saturated graphs that lie between these two extremes. We show that, for a fixed
+number of colors, bounding the guessing number is equivalent to forbidding a
+finite set of subgraphs.",2009.04529v1
+2020-09-10,Subradiance with saturated atoms: population enhancement of the long-lived states,"Dipole-dipole interactions are at the origin of long-lived collective atomic
+states, often called subradiant, which are explored for their potential use in
+novel photonic devices or in quantum protocols. Here, we study subradiance
+beyond linear optics and experimentally demonstrate a two hundred-fold increase
+in the population of these modes, as the saturation parameter of the driving
+field is increased. We attribute this enhancement to a mechanism similar to
+optical pumping through the well-coupled superradiant states. The lifetimes are
+unaffected by the pump strength, as the system is ultimately driven toward the
+single-excitation sector.",2009.05172v2
+2020-09-17,A generalisation of Schenkman's theorem,"Let $G$ be a finite group and let $\mathfrak{F}$ be a hereditary saturated
+formation. We denote by $\mathbf{Z}_{\mathfrak{F}}(G)$ the product of all
+normal subgroups $N$ of $G$ such that every chief factor $H/K$ of $G$ below $N$
+is $\mathfrak{F}$-central in $G$, that is, \[ (H/K) \rtimes
+(G/\mathbf{C}_{G}(H/K)) \in \mathfrak{F}. \]A subgroup $A \leq G$ is said to be
+$\mathfrak{F}$-subnormal in the sense of Kegel, or $K$-$\mathfrak{F}$-subnormal
+in $G$, if there is a subgroup chain \[ A = A_0 \leq A_1 \leq \ldots \leq A_n =
+G \] such that either $A_{i-1} \trianglelefteq A_{i}$ or $A_i / (A_{i-1})_{A_i}
+\in \mathfrak{F}$ for all $i = 1, \ldots , n$. In this paper, we prove the
+following generalisation of Schenkman's Theorem on the centraliser of the
+nilpotent residual of a subnormal subgroup: Let $\mathfrak{F}$ be a hereditary
+saturated formation and let $S$ be a $K$-$\mathfrak{F}$-subnormal subgroup of
+$G$. If $\mathbf{Z}_{\mathfrak{F}}(E) = 1$ for every subgroup $E$ of $G$ such
+that $S \leq E$ then $\mathbf{C}_{G}(D) \leq D$, where $D = S^{\mathfrak{F}}$
+is the $\mathfrak{F}$-residual of $S$.",2009.08145v1
+2020-09-28,An Analytical Solution of the Balitsky-Kovchegov Equation with the Homogeneous Balance Method,"Nonlinear QCD evolution equations are essential tools in understanding the
+saturation of partons at small Bjorken $x_{\rm B}$, as they are supposed to
+restore an upper bound of unitarity for the cross section of high energy
+scattering. In this paper, we present an analytical solution of
+Balitsky-Kovchegov (BK) equation using the homogeneous balance method. The
+obtained analytical solution is similar to the solution of a traveling wave. By
+matching the gluon distribution in the dilute region which is determined from
+the global analysis of experimental data (CT14 analysis), we get a definitive
+solution of the dipole-proton forward scattering amplitude in the momentum
+space. Based on the acquired scattering amplitude and the behavior of geometric
+scaling, we present also a new estimated saturation scale $Q_s^2(x)$.",2009.13325v2
+2020-10-16,Aging-Induced Dynamics for Statically Indeterminate System,"Statically indeterminate systems are experimentally demonstrated to be in
+fact dynamical at the microscopic scale. Take the classic ladder-wall problem,
+for instance. Depending on the Young's modulus of the wall, it may take up to
+twenty minutes before its weight saturates. This finding is shown to be shared
+by other statically indeterminate systems, such as a granule silo and a beam
+with three support points. We believe that the aging effect is responsible for
+this surprising phenomenon because it can be correlated with the evolution of
+microscopic contact area with the wall and floor. Finally, a heuristic and
+simple method is introduced that can uniquely determine and analytically solve
+the saturated weight without invoking detailed material properties.",2010.08289v2
+2020-10-20,Study of the structural defects on carbon nanotubes in metal matrix composites processed by severe plastic deformation,"Carbon nanotubes (CNT) have been recently proposed as stabilizers against
+grain growth that can happen even at low temperature inputs in nano-crystalline
+and ultrafine-grained materials obtained by severe plastic deformation. In this
+study, we analyzed the evolution of the structural defects on the nanotubes in
+CNT-reinforced nickel matrix composites with different reinforcement weight
+fractions. The composites were processed by high pressure torsion, and we used
+Raman spectroscopy as the main characterization technique. The results indicate
+that for CNT subjected to highly energetic processing, it is not sufficient to
+analyze only the ID/IG ratio (as proposed in the available literature), but it
+is also necessary to evaluate the shifting of the G band, which traces the
+amorphization trajectory undergone by the CNT. Furthermore, we observed that
+the deformation suffered by the CNT is related to the accumulated strain and
+varies with the partial CNT fractions of these composites. This is related to
+their capacity to withstand the plastic strain that occurs during deformation.
+In addition, the defective state reaches a saturation before achieving the
+saturation in the microstructural refinement. These results will help to
+efficiently optimize the processing of this type of engineering composites.",2010.10085v1
+2020-10-20,Analysis of the phase-locking dynamics of a III-V-on-silicon frequency comb laser,"We present the detailed characterization of the phase dynamics of a telecom
+hybrid III-V-on-silicon passively mode-locked laser with a ring cavity. We
+explore the various regimes of operation as a function of gain current and
+saturable absorber bias voltage. We use a stepped-heterodyne measurement to
+quantify the spectral chirp and reconstruct the pulse envelop. With this
+technique we are able to identify regimes of near-transform-limited operation
+and we assess the degradation of mode-locking in the comb phase relationship
+when saturable absorber bias voltage is changed. Finally, we present a
+preliminary study of the phase-locking in hybrid mode-locked operation and
+demonstrate transform-limited pulses.",2010.10362v1
+2020-10-22,Trajectory Tracking for Robotic Arms with Input Saturation and Only Position Measurements,"In this work, we propose a passivity-based control approach that addresses
+the trajectory tracking problem for a class of mechanical systems that
+comprises a broad range of robotic arms. The resulting controllers can be
+naturally saturated and do not require velocity measurements. Moreover, the
+proposed methodology does not require the implementation of observers, and the
+structure of the closed-loop system permits the identification of a Lyapunov
+function, which eases the convergence analysis. To corroborate the
+effectiveness of the methodology, we perform experiments with the Philips
+Experimental Robot Arm.",2010.11712v1
+2020-10-23,Investigating Saturation Effects in Integrated Gradients,"Integrated Gradients has become a popular method for post-hoc model
+interpretability. De-spite its popularity, the composition and relative impact
+of different regions of the integral path are not well understood. We explore
+these effects and find that gradients in saturated regions of this path, where
+model output changes minimally, contribute disproportionately to the computed
+attribution. We propose a variant of IntegratedGradients which primarily
+captures gradients in unsaturated regions and evaluate this method on ImageNet
+classification networks. We find that this attribution technique shows higher
+model faithfulness and lower sensitivity to noise com-pared with standard
+Integrated Gradients. A note-book illustrating our computations and results is
+available at https://github.com/vivekmig/captum-1/tree/ExpandedIG.",2010.12697v1
+2020-11-04,Universality in asymptotic bounds and its saturation in $2$D CFT,"We study asymptotics of three point coefficients (light-light-heavy) and two
+point correlators in heavy states in unitary, compact $2$D CFTs. We prove an
+upper and lower bound on such quantities using numerically assisted Tauberian
+techniques. We obtain an optimal upper bound on the spectrum of operators
+appearing with fixed spin from the OPE of two identical scalars. While all the
+CFTs obey this bound, rational CFTs come close to saturating it. This mimics
+the scenario of bounds on asymptotic density of states and thereby pronounces
+an universal feature in asymptotics of 2D CFTs. Next, we clarify the role of
+smearing in interpreting the asymptotic results pertaining to considerations of
+eigenstate thermalization in 2D CFTs. In the context of light-light-heavy three
+point coefficients, we find that the order one number in the bound is sensitive
+to how close the light operators are from the $\frac{c}{32}$ threshold. In
+context of two point correlator in heavy state, we find the presence of an
+enigmatic regime which separates the $AdS_3$ thermal physics and the BTZ black
+hole physics. Furthermore, we present some new numerical results on the
+behavior of spherical conformal block.",2011.02482v1
+2020-11-06,Estimating the nuclear saturation parameter via low-mass neutron star asteroseismology,"We examine the fundamental ($f$-) and the 1st pressure ($p_1$-) mode
+frequencies in gravitational waves from cold neutron stars constructed with
+various unified realistic equations of state. With the calculated frequencies,
+we derive the empirical formulae for the $f$- and $p_1$-mode frequencies, $f_f$
+and $f_{p_1}$, as a function of the square root of the stellar average density
+and the parameter ($\eta$), which is a combination of the nuclear saturation
+parameters. With our empirical formulae, we show that by simultaneously
+observing the $f$- and $p_1$-mode gravitational waves, when $1.5\lesssim
+f_{p_1}/f_f\lesssim 2.5$ (which corresponds to neutron star models with the
+mass of $\lesssim 0.9M_\odot$), one could estimate the value of $\eta$ within
+$\sim 10\%$ accuracy, which makes a strong constraint on the EOS for neutron
+star matter. In addition, we find that the maximum $f$-mode frequency is
+strongly associated with the minimum radius of neutron star. That is, if one
+would observe a larger frequency of the $f$-mode, one might constrain the upper
+limit of the minimum neutron star radius.",2011.03167v1
+2020-11-10,SWCNT@BNNT with 1D van der Waals Heterostructure with a High Optical Damage Threshold for Laser Mode-locking,"Single-walled carbon nanotube encapsulated in boron nitrite nanotube
+(SWCNT@BNNT) is a novel nanomaterial with a one-dimensional van der Waals
+(1D-vdW) heterostructure. In this paper, we demonstrated that the SWCNT@BNNT
+has an enhanced optical power tolerance compared to that of the pristine SWCNT
+while exhibiting an optical saturable absorption properties. Under optical
+power intensity of 13kW/cm2, the lifetime of the SWCNT@BNNT is found to be
+2,270 times longer than SWCNT for 1% degradation in absorbance. A short-cavity
+mode-locked laser with a high repetition rate of 1 GHz has been realized using
+the SWCNT@BNNT as the saturable absorber. We have shown that the technique of
+fabricating nanomaterial with a 1D-vdW heterostructure can modify and enhance
+the optical properties of the encapsulated nanomaterials.",2011.04647v1
+2020-11-12,Configurational Entropy of Optical Bright Similariton in Tapered Graded-Index Waveguide,"Configurational entropy (CE) consists of a family of entropic measures of
+information used to describe the shape complexity of spatially-localized
+functions with respect to a set of parameters. We obtain the Differential
+Configurational Entropy (DCE) for similariton waves traveling in tapered
+graded-index optical waveguides modeled by a generalized nonlinear
+Schr\""odinger equation. It is found that for similariton's widths lying within
+a certain range, DCE attains minimum saturation values as the nonlinear wave
+evolves along the effective propagation variable $\zeta(t)$. In particular,
+saturation is achieved earlier for lower values of the width, which we show
+correspond to global minima of the DCE. Such low entropic values lead to
+minimum dispersion of momentum modes as the similariton waves propagate along
+tapered graded-index waveguides, and should be of importance in guiding their
+design.",2011.06926v1
+2020-11-16,Note on entropy dynamics in the Brownian SYK model,"We study the time evolution of R\'enyi entropy in a system of two coupled
+Brownian SYK clusters evolving from an initial product state. The R\'enyi
+entropy of one cluster grows linearly and then saturates to the coarse grained
+entropy. This Page curve is obtained by two different methods, a path integral
+saddle point analysis and an operator dynamics analysis. Using the Brownian
+character of the dynamics, we derive a master equation which controls the
+operator dynamics and gives the Page curve for purity. Insight into the physics
+of this complicated master equation is provided by a complementary path
+integral method: replica diagonal and non-diagonal saddles are responsible for
+the linear growth and saturation of R\'enyi entropy, respectively.",2011.08158v2
+2020-11-18,Leading neutron production at the EIC and LHeC: estimating the impact of the absorptive corrections,"Leading neutron (LN) production in $ep$ collisions at high energies is
+investigated using the color dipole formalism and taking into account
+saturation effects. We update the treatment of absorptive effects and estimate
+the impact of these effects on LN spectra in the kinematical range that will be
+probed by the Electron Ion Collider (EIC) and by the Large Hadron electron
+Collider (LHeC). We demonstrate that Feynman scaling, associated to saturation,
+is not violated by the inclusion of absorptive effects. Moreover, our results
+indicate that the LN spectrum is strongly suppressed at small photon
+virtualities. These results suggest that absorptive effects cannot be
+disregarded in future measurements of the $\gamma \pi$ cross section to be
+extracted from data on leading neutron production.",2011.09515v1
+2020-12-02,Adaptive prescribed-time disturbance observer using nonsingular terminal sliding mode control: Extended Kalman filter and particle swarm optimization,"In this paper, adaptive prescribed finite time stabilization of uncertain
+single-input and single-output nonlinear systems is considered in the presence
+of unknown states, unknown parameters, external load disturbance, and
+non-symmetric input saturation. A prescribed finite time disturbance observer
+is designed to approximate the unmeasured external disturbance. Also, a
+nonsingular prescribed finite time terminal sliding mode control is proposed
+for the closed-loop control of the system with the non-symmetric input
+saturation. Extended Kalman filter algorithm is employed for the real-time
+estimations of the states and unknown parameters of the system. Moreover,
+particle swarm optimization algorithm is used to obtain the design parameters
+of the proposed disturbance observer and controller. To show the performance of
+designed control scheme, the proposed approach is employed to guarantee
+prescribed finite time stabilization of nonlinear vibration of a nonlocal
+strain gradient nanobeam. Finally, numerical simulations are performed to
+illustrate the effectiveness and performance of the developed adaptive control
+scheme for the vibration control of nanobeam in comparison to the conventional
+sliding mode control.",2012.01026v1
+2020-12-02,Homogenization of large deforming fluid-saturated porous structures,"The two-scale computational homogenization method is proposed for modelling
+of locally periodic fluid-saturated media subjected a to large deformation
+induced by quasistatic loading. The periodic heterogeneities are relevant to
+the mesoscopic scale at which a double porous medium constituted by
+hyperelastic skeleton and an incompressible viscous fluid is featured by large
+contrasts in the permeability. Within the Eulerian framework related to the
+current deformed configuration, the two-scale homogenization approach is
+applied to a linearized model discretized in time, being associated with an
+incremental formulation. For this, the equilibrium equation and the mass
+conservation expressed in the spatial configuration are differentiated using
+the material derivative with respect to a convection velocity field. The
+homogenization procedure of the linearized equations provides effective
+(homogenized) material properties are computed to constitute the incremental
+macroscopic problem. The coupled algorithm for the multiscale problem is
+implemented using the finite element method. Illustrative 2D numerical
+simulations of a poroelastic medium are presented including a simple validation
+test.",2012.03730v1
+2020-12-10,Global linear and nonlinear gyrokinetic modelling of Alfvén eigenmodes in ITER,"Linear and nonlinear modelling of Alfv\'enic instabilities, most notably
+toroidal Alfv\'en eigenmodes (TAEs), obtained by using the global nonlinear
+electromagnetic gyrokinetic model of the code ORB5 are presented for the 15 MA
+scenario of the ITER tokamak. Linear simulations show that elliptic Alfv\'en
+eigenmodes and odd-parity TAEs are only weakly damped but not excited by alpha
+particles, whose drive favours even-parity TAEs. Low mode number TAEs are found
+to be global, requiring global treatment. Nonlinearly, even with double the
+nominal EP density, single mode simulations lead to saturation with negligible
+EP transport however multi-mode simulations predict that with double the
+nominal EP density, enhanced saturation and significant EP redistribution will
+occur.",2012.05651v1
+2020-12-12,Heterochromatic nonlinear optical responses in upconversion nanoparticles for point spread function engineering,"Point spread function (PSF) engineering of the emitter can code higher
+spatial frequency information of an image to break diffraction limit but suffer
+from the complexed optical systems. Here we present a robust strategy to
+simultaneously achieve diverse PSFs from upconversion nanoparticles under a
+single doughnut-shape scanning beam. By saturating the four-photon state, the
+high-frequency information can be extracted through the doughnut emission PSF.
+In contrast, the complementary lower frequency information can be carried out
+by the Gaussian-like emission PSF, as a result of over-saturated at the
+two-photon state. With the Fourier domain heterochromatic fusion, we verify the
+capability of the synthesised PSF to cover both low and high-frequency
+information, yielding the overall enhanced image quality. We show a spatial
+resolution of 40 nm, 1/24th of the excitation wavelength. This work suggests a
+new scope for developing nonlinear multi-colour emitting probes to improve
+image quality and noise control in nanoscopy.",2012.06704v2
+2020-12-14,Saturation of Newton polytopes of type A and D cluster variables,"We study Newton polytopes for cluster variables in cluster algebras
+$\mathcal{A}(\Sigma)$ of types A and D. A famous property of cluster algebras
+is the Laurent phenomenon: each cluster variable can be written as a Laurent
+polynomial in the cluster variables of the initial seed $\Sigma$. The cluster
+variable Newton polytopes are the Newton polytopes of these Laurent
+polynomials. We show that if $\Sigma$ has principal coefficients or boundary
+frozen variables, then all cluster variable Newton polytopes are saturated. We
+also characterize when these Newton polytopes are \emph{empty}; that is, when
+they have no non-vertex lattice points.",2012.07500v2
+2020-12-17,"Topological structures on saturated sets, optimal orbits and equilibrium states","Pfister and Sullivan proved that if a topological dynamical system $(X,T)$
+satisfies almost product property and uniform separation property, then for
+each nonempty compact %convex subset $K$ of invariant measures, the entropy of
+saturated set $G_{K}$ satisfies \begin{equation}\label{Bowen's topological
+entropy}
+  h_{top}^{B}(T,G_{K})=\inf\{h(T,\mu):\mu\in K\}, \end{equation} where
+$h_{top}^{B}(T,G_{K})$ is Bowen's topological entropy of $T$ on $G_{K}$, and
+$h(T,\mu)$ is the Kolmogorov-Sinai entropy of $\mu$. In this paper, we
+investigate topological complexity of $G_{K}$ by replacing Bowen's topological
+entropy with upper capacity entropy and packing entropy and obtain the
+following formulas: \begin{equation*}
+  h_{top}^{UC}(T,G_{K})=h_{top}(T,X)\ \mathrm{and}\
+h_{top}^{P}(T,G_{K})=\sup\{h(T,\mu):\mu\in K\}, \end{equation*} where
+$h_{top}^{UC}(T,G_{K})$ is the upper capacity entropy of $T$ on $G_{K}$ and
+$h_{top}^{P}(T,G_{K})$ is the packing entropy of $T$ on $G_{K}.$ In the proof
+of these two formulas, uniform separation property is unnecessary.",2012.09482v2
+2020-12-18,Resonant Shattering Flares as Multimessenger Probes of the Nuclear Symmetry Energy,"The behaviour of the nuclear symmetry energy near saturation density is
+important for our understanding of dense nuclear matter. This density
+dependence can be parameterised by the nuclear symmetry energy and its
+derivatives evaluated at nuclear saturation density. In this work we show that
+the core-crust interface mode of a neutron star is sensitive to these
+parameters, through the (density-weighted) shear-speed within the crust, which
+is in turn dependent on the symmetry energy profile of dense matter. We
+calculate the frequency at which the neutron star quadrupole ($\ell = 2$)
+crust-core interface mode must be driven by the tidal field of its binary
+partner to trigger a Resonant Shattering Flare (RSF). We demonstrate that
+coincident multimessenger timing of an RSF and gravitational wave chirp from a
+neutron star merger would enable us to place constraints on the symmetry energy
+parameters that are competitive with those from current nuclear experiments.",2012.10322v2
+2020-12-28,Entanglement Monotones from Complementarity Relations,"Bohr's complementarity and Schr\""odinger's entanglement are two prominent
+physical characters of quantum systems. In this letter, we formally connect
+them. It is known that complementarity relations for wave-particle duality are
+saturated only for pure, single-quanton, quantum states. For mixed states, the
+wave-particle quantifiers never saturate a complementarity relation and can
+even reach zero for a maximally mixed state. To fully characterize a quanton,
+it is not enough to consider its wave-particle aspect; we have also to regard
+its quantum correlations with other systems. Here we prove that for any
+complete complementarity relation involving predictability and visibility
+measures that satisfy the criteria established in the literature, these
+corresponding quantum correlations are entanglement monotones.",2012.14471v4
+2020-12-30,Correcting thermal-emission-induced detector saturation in infrared reflection or transmission spectroscopy,"We found that temperature-dependent infrared spectroscopy measurements (i.e.,
+reflectance or transmittance) using a Fourier-transform spectrometer can have
+substantial errors, especially for elevated sample temperatures and collection
+using an objective lens (e.g., using an infrared microscope). These errors
+arise as a result of partial detector saturation due to thermal emission from
+the measured sample reaching the detector, resulting in nonphysical apparent
+reduction of reflectance or transmittance with increasing sample temperature.
+Here, we demonstrate that these temperature-dependent errors can be corrected
+by implementing several levels of optical attenuation that enable ""convergence
+testing"" of the measured reflectance or transmittance as the thermal-emission
+signal is reduced, or by applying correction factors that can be inferred by
+looking at the spectral regions where the sample is not expected to have a
+substantial temperature dependence.",2012.14987v2
+2021-01-01,Period-doubling bifurcation in spatiotemporal mode-locked lasers,"Period-doubling bifurcation is a universal dynamic of nonlinear systems,
+which has been extensively investigated in laser systems with a single
+transverse mode. This study presents an experimental observation and
+theoretical investigation of the period-doubling bifurcation in spatiotemporal
+mode-locked (STML) multimode fiber lasers. In the period-doubling state, it is
+observed that the pulse train modulation varies with the transverse-mode, and
+the output beam profile fluctuates rapidly and periodically. The numerical
+simulations conducted in this study are in good agreement with the experimental
+observations. Furthermore, a simple iterative model is proposed by considering
+the mode-dependent saturable absorption effect, and the experimental results
+can be qualitatively interpreted by this model. Based on these results,
+spatiotemporal saturable absorption is believed to be the key factor for the
+unique spatiotemporal characteristic of period-doubling bifurcation in
+multimode lasers. This study contributes to the understanding of the complex
+spatiotemporal dynamics in STML multimode lasers and to the discovery of novel
+dynamics in high-dimensional nonlinear systems.",2101.00149v1
+2021-01-05,Equality Saturation for Tensor Graph Superoptimization,"One of the major optimizations employed in deep learning frameworks is graph
+rewriting. Production frameworks rely on heuristics to decide if rewrite rules
+should be applied and in which order. Prior research has shown that one can
+discover more optimal tensor computation graphs if we search for a better
+sequence of substitutions instead of relying on heuristics. However, we observe
+that existing approaches for tensor graph superoptimization both in production
+and research frameworks apply substitutions in a sequential manner. Such
+sequential search methods are sensitive to the order in which the substitutions
+are applied and often only explore a small fragment of the exponential space of
+equivalent graphs. This paper presents a novel technique for tensor graph
+superoptimization that employs equality saturation to apply all possible
+substitutions at once. We show that our approach can find optimized graphs with
+up to 16% speedup over state-of-the-art, while spending on average 48x less
+time optimizing.",2101.01332v2
+2021-01-07,"Regression-based causal inference with factorial experiments: estimands, model specifications, and design-based properties","Factorial designs are widely used due to their ability to accommodate
+multiple factors simultaneously. The factor-based regression with main effects
+and some interactions is the dominant strategy for downstream data analysis,
+delivering point estimators and standard errors via one single regression.
+Justification of these convenient estimators from the design-based perspective
+requires quantifying their sampling properties under the assignment mechanism
+conditioning on the potential outcomes. To this end, we derive the sampling
+properties of the factor-based regression estimators from both saturated and
+unsaturated models, and demonstrate the appropriateness of the robust standard
+errors for the Wald-type inference. We then quantify the bias-variance
+trade-off between the saturated and unsaturated models from the design-based
+perspective, and establish a novel design-based Gauss--Markov theorem that
+ensures the latter's gain in efficiency when the nuisance effects omitted
+indeed do not exist. As a byproduct of the process, we unify the definitions of
+factorial effects in various literatures and propose a location-shift strategy
+for their direct estimation from factor-based regressions. Our theory and
+simulation suggest using factor-based inference for general factorial effects,
+preferably with parsimonious specifications in accordance with the prior
+knowledge of zero nuisance effects.",2101.02400v2
+2021-01-10,Tuning Dzyaloshinskii-Moriya Interaction in Ferrimagnetic GdCo: A First Principles Approach,"We present a systematic analysis of our ability to tune chiral
+Dzyaloshinskii-Moriya Interactions (DMI) in compensated ferrimagnetic
+Pt/GdCo/Pt1-xWx trilayers by cap layer composition. Using first principles
+calculations, we show that the DMI increases rapidly for only ~ 10% W and
+saturates thereafter, in agreement with experiments. The calculated DMI shows a
+spread in values around the experimental mean, depending on the atomic
+configuration of the cap layer interface. The saturation is attributed to the
+vanishing of spin orbit coupling energy at the cap layer and the simultaneous
+constancy at the bottom interface. Additionally, we predict the DMI in
+Pt/GdCo/X (X=Ta, W, Ir) and find that W in the cap layer favors a higher DMI
+than Ta and Ir that can be attributed to the difference in d-band alignment
+around the Fermi level. Our results open up exciting combinatorial
+possibilities for controlling the DMI in ferrimagnets towards nucleating and
+manipulating ultrasmall high-speed skyrmions.",2101.03449v1
+2021-01-11,"Generalized saturation problems for cliques, paths, and stars","A graph $G$ is $F$-saturated if it does not contain any copy of $F$, but the
+addition of any missing edge in $G$ creates at least one copy of $F$. Inspired
+by work of Alon and Shikhelman regarding a similar question for $F$-free
+graphs, Kritschgau, Methuku, Tait, and Timmons introduced the parameter of
+$\text{sat}_H(n,F)$ to denote the minimum number of copies of some subgraph $H$
+in an $F$-saturated graph on $n$ vertices. In this paper, we address this
+generalized saturation problem with special focus on $\text{sat}_{K_r}(n,S_t)$
+and $\text{sat}_{S_r}(n,S_t)$ This relates to recent work by Chakraborti and
+Loh regarding $\text{sat}_{K_r}(n,K_t)$ and by Ergemlidze, Methuku, Tait, and
+Timmons regarding $\text{sat}_{S_r}(n,K_t)$. We also provide some results
+regarding paths and arbitrary trees.",2101.04213v4
+2021-01-12,Fluid pressurisation and earthquake propagation in the Hikurangi subduction zone,"In subduction zones, seismic slip at shallow crustal depths can lead to the
+generation of tsunamis. Large slip displacements during tsunamogenic
+earthquakes are attributed to the low coseismic shear strength of the
+fluid-saturated and non-lithified clay-rich fault rocks. However, because of
+experimental challenges in confining these materials, the physical processes
+responsible of the coseismic reduction in fault shear strength are poorly
+understood. Using a novel experimental setup, we measured pore fluid pressure
+during simulated seismic slip in clay-rich materials sampled from the deep
+oceanic drilling of the P\=apaku thrust (Hikurangi subduction zone, New
+Zealand). Here we show that at seismic velocity, shear-induced dilatancy is
+followed by pressurisation of fluids. The thermal and mechanical pressurisation
+of fluids, enhanced by the low permeability of the fault, reduces the energy
+required to propagate earthquake rupture. We suggest that fluid-saturated
+clay-rich sediments, occurring at shallow depth in subduction zones, can
+promote earthquake rupture propagation and slip because of their low
+permeability and tendency to pressurise when sheared at seismic slip
+velocities.",2101.04336v2
+2021-01-13,Saturating PI control of stable nonlinear systems using singular perturbations,"This paper presents an anti-windup PI controller, using a saturating
+integrator, for a single-input single-output stable nonlinear plant, whose
+steady-state input-output map is increasing. We prove that, under reasonable
+assumptions, there exists an upper bound on the controller gain such that for
+any constant reference input, the corresponding equilibrium point of the
+closed-loop system is exponentially stable, with a ""large"" region of
+attraction. When the state of the closed-loop system converges to this
+equilibrium point, then the tracking error tends to zero. The closed-loop
+stability analysis employs Lyapunov methods in the framework of singular
+perturbations theory. Finally, we show that if the plant satisfies the
+asymptotic gain property, then the closed-loop system is globally
+asymptotically stable for any sufficiently small controller gain. The
+effectiveness of the proposed PI controller is proved by showing how it
+performs as part of the control algorithm of a synchronverter (a special type
+of DC to AC power converter).",2101.05122v2
+2021-01-23,Nonlinear plane waves in saturated porous media with incompressible constituents,"We consider the propagation of nonlinear plane waves in porous media within
+the framework of the Biot-Coussy biphasic mixture theory. The tortuosity effect
+is included in the model, and both constituents are assumed incompressible
+(Yeoh-type elastic skeleton, and saturating fluid). In this case, the linear
+dispersive waves governed by Biot's theory are either of compression or
+shear-wave type, and nonlinear waves can be classified in a similar way. In the
+special case of a neo-Hookean skeleton, we derive the explicit expressions for
+the characteristic wave speeds, leading to the hyperbolicity condition. The
+sound speeds for a Yeoh skeleton are estimated using a perturbation approach.
+Then we arrive at the evolution equation for the amplitude of acceleration
+waves. In general, it is governed by a Bernoulli equation. With the present
+constitutive assumptions, we find that longitudinal jump amplitudes follow a
+nonlinear evolution, while transverse jump amplitudes evolve in an almost
+linearly degenerate fashion.",2101.09507v3
+2021-01-27,Observation of photon recoil effects in single-beam absorption spectroscopy with an ultracold strontium gas,"We report on observing photon recoil effects in the absorption of a single
+monochromatic light at 689~nm through an ultracold $^{88}$Sr gas, where the
+recoil frequency is comparable to natural linewidth of the narrow-line
+transition $5\mathrm{s^2}\, ^1\textrm{S}_0 - 5\mathrm{s}5\mathrm{p}\,
+^3\textrm{P}_1$ in strontium. In the regime of high-saturation, the absorption
+profile becomes asymmetric due to the photon-recoil shift, which is of the same
+order as the natural linewidth. The lineshape is described by an extension of
+the optical Bloch equations including the momentum transfers to atoms during
+emission and absorption of photons. Our work reveals the photon recoil effects
+in a simplest single-beam absorption setting, which is of significant relevance
+to other applications such as saturation spectroscopy, Ramsey interferometry,
+and absorption imaging.",2101.11176v2
+2021-02-01,Temporal Cavity Solitons in a Laser-based Microcomb: A Path to a Self-Starting Pulsed Laser without Saturable Absorption,"We theoretically present a design of self-starting operation of microcombs
+based on laser-cavity solitons in a system composed of a micro-resonator nested
+in and coupled to an amplifying laser cavity. We demonstrate that it is
+possible to engineer the modulational-instability gain of the system's zero
+state to allow the start-up with a well-defined number of robust solitons. The
+approach can be implemented by using the system parameters, such as the cavity
+length mismatch and the gain shape, to control the number and repetition rate
+of the generated solitons. Because the setting does not require saturation of
+the gain, the results offer an alternative to standard techniques that provide
+laser mode-locking.",2102.01164v1
+2021-02-08,Curse of Dimensionality for TSK Fuzzy Neural Networks: Explanation and Solutions,"Takagi-Sugeno-Kang (TSK) fuzzy system with Gaussian membership functions
+(MFs) is one of the most widely used fuzzy systems in machine learning.
+However, it usually has difficulty handling high-dimensional datasets. This
+paper explores why TSK fuzzy systems with Gaussian MFs may fail on
+high-dimensional inputs. After transforming defuzzification to an equivalent
+form of softmax function, we find that the poor performance is due to the
+saturation of softmax. We show that two defuzzification operations, LogTSK and
+HTSK, the latter of which is first proposed in this paper, can avoid the
+saturation. Experimental results on datasets with various dimensionalities
+validated our analysis and demonstrated the effectiveness of LogTSK and HTSK.",2102.04271v1
+2021-02-15,Breaking Reciprocity in a non-Hermitian Photonic Coupler with Saturable Absorption,"We study the breaking of reciprocity in non-Hermitian coupled photonic
+waveguides by the simultaneous action of the nonlinear effect of saturable
+absorption, and the presence of exceptional points. The nonlinear response of
+such a system is studied in depth, giving physical insight into the operational
+principles and fundamental limitations, while producing analytical and
+semi-analytical results for the transmission and nonreciprocal intensity range.
+We numerically validate the theoretical results and assess important
+performance metrics for the nonreciprocal operation of such a device. This
+novel class of passive non-resonant devices can offer on-chip broadband
+nonreciprocal operation, making them potentially very important for high-speed
+applications.",2102.07483v1
+2021-02-20,High resolution imaging with anomalous saturated excitation,"The nonlinear fluorescence emission has been widely applied for the high
+spatial resolution optical imaging. Here, we studied the fluorescence anomalous
+saturating effect of the nitrogen vacancy defect in diamond. The fluorescence
+reduction was observed with high power laser excitation. It increased the
+nonlinearity of the fluorescence emission, and changed the spatial frequency
+distribution of the fluorescence image. We used a differential excitation
+protocol to extract the high spatial frequency information. By modulating the
+excitation laser's power, the spatial resolution of imaging was improved
+approximate 1.6 times in comparison with the confocal microscopy. Due to the
+simplicity of the experimental setup and data processing, we expect this method
+can be used for improving the spatial resolution of sensing and biological
+labeling with the defects in solids.",2102.10363v1
+2021-02-25,Supercontinuum Generation by Saturated Second-Order Nonlinear Interactions,"We propose a new approach to supercontinuum generation and
+carrier-envelope-offset detection based on saturated second-order nonlinear
+interactions in dispersion-engineered nanowaveguides. The technique developed
+here broadens the interacting harmonics by forming stable bifurcations of the
+pulse envelopes due to an interplay between phase-mismatch and pump depletion.
+We first present an intuitive heuristic model for spectral broadening by
+second-harmonic generation of femtosecond pulses, and show that this model
+agrees well with experiments. Then, having established strong agreement between
+theory and experiment, we develop scaling laws that determine the energy
+required to generate an octave of bandwidth as a function of input pulse
+duration, device length, and input pulse chirp. These scaling laws suggest that
+future realization based on this approach could enable supercontinuum
+generation with orders of magnitude less energy than current state-of-the-art
+devices.",2102.12856v5
+2021-02-25,Integration questions in separably good characteristics,"Let G be a reductive group over an algebraically closed field k of separably
+good characteristic p>0 for G. Under these assumptions a Springer isomorphism
+from the reduced nilpotent scheme of the Lie algebra of G to the reduced
+unipotent scheme of G always exists. This allows to integrate any p-nilpotent
+element of Lie(G) into a unipotent element of G. One should wonder whether such
+a punctual integration can lead to a systematic integration of p-nil
+subalgebras of Lie(G). We provide counterexamples of the existence of such an
+integration in general as well as criteria to integrate some p-nil subalgebras
+of Lie(G) (that are maximal in a certain sense). This requires to generalise
+the notion of infinitesimal saturation first introduced by P. Deligne and to
+extend one of his theorem on infinitesimally saturated subgroups of G to the
+previously mentioned framework.",2102.13077v6
+2021-02-26,A wavelength-tunable mode-locked Yb-doped fiber laser based on nonlinear Kerr beam clean-up effect,"We demonstrate a novel approach to achieve wavelength-tunable ultrashort
+pulses from an all-fiber mode-locked laser with a saturable absorber based on
+nonlinear Kerr beam clean-up effect. This saturable absorber was formed by a
+single-mode fiber spliced to a graded-index multimode fiber, and its tunable
+band-pass filter effect is studied by a numerical model. By adjusting the
+bending condition of graded-index multimode fiber, the laser could produce
+dissipative soliton pulses with their central wavelength tunable from1040 nm to
+1063 nm. The pulse width of output laser could be compressed externally to 791
+fs, and the signal to noise ratio of its radio frequency spectrum was measured
+to be 75.5 dB. This work provides a new idea for the design of
+wavelength-tunable mode-locked laser which can be used as an attractive light
+source in communication system.",2102.13428v3
+2021-03-02,Shortening X-ray Pulse Duration via Saturable Absorption,"To shorten the duration of x-ray pulses, we present a nonlinear optical
+technique using atoms with core-hole vacancies (core-hole atoms) generated by
+inner-shell photoionization. The weak Coulomb screening in the core-hole atoms
+results in decreased absorption at photon energies immediately above the
+absorption edge. By employing this phenomenon, referred to as saturable
+absorption, we successfully reduce the duration of x-ray free-electron laser
+pulses (photon energy: 9.000 keV, duration: 6-7 fs, fluence:
+2.0-3.5$\times$10$^5$ J/cm$^2$) by $\sim$35%. This finding that core-hole atoms
+are applicable to nonlinear x-ray optics is an essential stepping stone for
+extending nonlinear technologies commonplace at optical wavelengths to the hard
+x-ray region.",2103.01510v2
+2021-03-03,Critical Parameters for Scalable Distributed Learning with Large Batches and Asynchronous Updates,"It has been experimentally observed that the efficiency of distributed
+training with stochastic gradient (SGD) depends decisively on the batch size
+and -- in asynchronous implementations -- on the gradient staleness.
+Especially, it has been observed that the speedup saturates beyond a certain
+batch size and/or when the delays grow too large. We identify a data-dependent
+parameter that explains the speedup saturation in both these settings. Our
+comprehensive theoretical analysis, for strongly convex, convex and non-convex
+settings, unifies and generalized prior work directions that often focused on
+only one of these two aspects. In particular, our approach allows us to derive
+improved speedup results under frequently considered sparsity assumptions. Our
+insights give rise to theoretically based guidelines on how the learning rates
+can be adjusted in practice. We show that our results are tight and illustrate
+key findings in numerical experiments.",2103.02351v1
+2021-03-04,A vertex scheme for two-phase flow in heterogeneous media,"This paper presents the numerical solution of immiscible two-phase flows in
+porous media, obtained by a first-order finite element method equipped with
+mass-lumping and flux up-winding. The unknowns are the physical phase pressure
+and phase saturation. Our numerical experiments confirm that the method
+converges optimally for manufactured solutions. For both structured and
+unstructured meshes, we observe the high-accuracy wetting saturation profile
+that ensures minimal numerical diffusion at the front. Performing several
+examples of quarter-five spot problems in two and three dimensions, we show
+that the method can easily handle heterogeneities in the permeability field.
+Two distinct features that make the method appealing to reservoir simulators
+are: (i) maximum principle is satisfied, and (ii) mass balance is locally
+conserved.",2103.03285v2
+2021-03-07,"Assignments of the $X(4140)$, $X(4500)$, $X(4630)$ and $X(4685)$ based on the QCD sum rules","In this article, we take into account our previous calculations based on the
+QCD sum rules, and tentatively assign the $X(4630)$ as the
+$D_s^*\bar{D}_{s1}-D_{s1}\bar{D}_s^*$ tetraquark molecular state or
+$[cs]_P[\bar{c}\bar{s}]_A+[cs]_A[\bar{c}\bar{s}]_P$ tetraquark state with the
+$J^{PC}=1^{-+}$, and assign the $X(3915)$ and $X(4500)$ as the 1S and 2S
+$[cs]_A[\bar{c}\bar{s}]_A$ tetraquark states respectively with the
+$J^{PC}=0^{++}$. Then we extend our previous works to investigate the LHCb's
+new tetraquark candidate $X(4685)$ as the first radial excited state of the
+$X(4140)$ with the QCD sum rules, and obtain the mass
+$M_{X}=4.70\pm0.12\,\rm{GeV}$, which is in very good agreement with the
+experimental value $4684 \pm 7 {}^{+13}_{-16}\,\rm{MeV}$. Furthermore, we
+investigate the two-meson scattering state contributions in details, and
+observe that the two-meson scattering states alone cannot saturate the QCD sum
+rules, the contributions of the tetraquark states play an un-substitutable
+role, we can saturate the QCD sum rules with or without the two-meson
+scattering states.",2103.04236v3
+2021-03-09,Impact of intrinsic charm amount in the nucleon and saturation effects on the prompt atmospheric $ν_μ$ flux for IceCube,"The predictions for the atmospheric neutrino flux at high energies strongly
+depend on the contribution of prompt neutrinos, which are determined by the
+production of charmed meson in the atmosphere at very forward rapidities. In
+this paper we estimate the related cross sections taking into account the
+presence of an intrinsic charm (IC) component in the proton wave function and
+the QCD dynamics modified by the onset of saturation effects. The impact on the
+predictions for the prompt neutrino flux is investigated assuming different
+values for the probability to find the IC in the nucleon. Comparison with the
+IceCube data is performed and conclusions are drawn.",2103.05503v2
+2021-03-10,Effects of confinement on the dynamics and correlation scales in active fluids,"We study the influence of solid boundaries on dynamics and structure of
+active fluids as the height of the container, $z$, changes. Along the varying
+dimension, the geometry systematically increases, therefore, the confinement
+($z$) transits from ""strong confinement"", to ""intermediate confinement"" and to
+""weak confinement"" (close to ""unconfined""). In horizontal dimensions ($x,y$),
+the system remains ""unconfined"". Through tracking the tracers dispersed in the
+active fluids in three dimensions we observed that activity level,
+characterized by velocity fluctuations of flow tracers, increases as system
+size increases. Concomitantly, the velocity-velocity temporal correlation
+changes from weak correlation to strong positive correlation, indicating
+""memory"" in active flows. We estimate the characteristic size of the flow
+structure by integrating the velocity-velocity spatial correlation function.
+The integral increases as confinement becomes weaker and saturates at
+approximately 400 microns as the system becomes ""unconfined"". This saturation
+indicates an intrinsic length scale which, along with the small-scale isotropy,
+demonstrates the multi-scale nature of this kinesin-driven bundled microtubule
+system.",2103.06334v1
+2021-03-11,Quasi-static perforation of the ceramic foam core sandwich panels impregnated with Newtonian and non-Newtonian fluids,"In this research, Mechanical response and energy absorption of ceramic foam
+sandwich panels filled with Newtonian and non-Newtonian fluid subjected to
+quasi-static indentation loads were investigated experimentally. In addition,
+the effects of number of face-sheet layers (face-sheet thickness) and boundary
+conditions on the mechanical response and energy absorption of sandwich panels
+were discussed. Sandwich panels consisted of two glass/epoxy face-sheets with
+different thicknesses (4 and 8 layers) and an open cell ceramic foam core. This
+foam saturated with Newtonian (Glycerol) and non-Newtonian (mixture of Ethylene
+glycol and Aerosil) fluids. Sandwich panels were tested in two different kinds
+of supporting conditions, simply-supported and fully fixed (clamped). Results
+showed that damage area in neat composite and STF filled sandwich panels are
+much higher than the glycerol filled foam core sandwich panels. Also, STF
+saturated sandwich panels absorbed higher energy compared with two other type
+of sandwich panels during quasi-static punch shear test.",2103.06952v1
+2021-03-16,Prediction of three-phase relative permeabilities of Berea sandstone using lattice Boltzmann method,"Three-phase flows through a pore network of Berea sandstone are studied
+numerically under critical interfacial tension condition. Results show that the
+relative permeability of each fluid increases as its own saturation increases.
+The specific interfacial length between wetting and non-wetting fluids
+monotonously decreases with increasing the saturation of intermediate-wetting
+fluid, while the other two specific interfacial lengths exhibit a
+non-monotonous variation. As the wetting (non-wetting) fluid becomes less
+wetting (non-wetting), the relative permeability of wetting fluid monotonously
+increases, while the other two relative permeabilities show a non-monotonous
+trend. Due to the presence of spreading layer, the specific interfacial length
+between wetting and non-wetting fluids always stabilizes at a low level. As the
+viscosity ratio of wetting (non-wetting) to intermediate-wetting fluids
+increases, the relative permeability of wetting (non-wetting) fluid increases.
+With the viscosity ratio deviating from unity, the phase interfaces become
+increasingly unstable, leading to an increased specific interfacial length.",2103.08787v1
+2021-03-17,Nonlinear coupling of reversed shear Alfven eigenmode and toroidal Alfven eigenmode during current ramp,"Two novel nonlinear mode coupling processes for reversed shear Alfven
+eigenmode (RSAE) nonlinear saturation are proposed and investigated. In the
+first process, RSAE nonlinearly couples to a co-propagating toroidal Alfven
+eigenmode (TAE) with the same toroidal and poloidal mode numbers, and generates
+a geodesic acoustic mode (GAM). In the second process, RSAE couples to a
+counter-propagating TAE and generates an ion acoustic wave quasi-mode (IAW).
+The condition for the two processes to occur is favored during current ramp.
+Both processes contribute to effectively saturate the Alfvenic instabilities,
+as well as nonlinearly transfer of energy from energetic fusion alpha particles
+to fuel ions in burning plasmas.",2103.09446v1
+2021-03-24,Nuclear matter in relativistic Brueckner-Hartree-Fock theory with Bonn potential in the full Dirac space,"Starting from the Bonn potential, relativistic Brueckner-Hartree-Fock (RBHF)
+equations are solved for nuclear matter in the full Dirac space, which provides
+a unique way to determine the single-particle potentials and avoids the
+approximations applied in the RBHF calculations in the Dirac space with
+positive-energy states (PESs) only. The uncertainties of the RBHF calculations
+in the Dirac space with PESs only are investigated, and the importance of the
+RBHF calculations in the full Dirac space is demonstrated. In the RBHF
+calculations in the full Dirac space, the empirical saturation properties of
+symmetric nuclear matter are reproduced, and the obtained equation of state
+agrees with the results based on the relativistic Green's function approach up
+to the saturation density.",2103.12960v1
+2021-03-24,Ripple-Type Control for Enhancing Resilience of Networked Physical Systems,"Distributed control agents have been advocated as an effective means for
+improving the resiliency of our physical infrastructures under unexpected
+events. Purely local control has been shown to be insufficient, centralized
+optimal resource allocation approaches can be slow. In this context, we put
+forth a hybrid low-communication saturation-driven protocol for the
+coordination of control agents that are distributed over a physical system and
+are allowed to communicate with peers over a ""hotline"" communication network.
+According to this protocol, agents act on local readings unless their control
+resources have been depleted, in which case they send a beacon for assistance
+to peer agents. Our ripple-type scheme triggers communication locally only for
+the agents with saturated resources and it is proved to converge. Moreover,
+under a monotonicity assumption on the underlying physical law coupling control
+outputs to inputs, the devised control is proved to converge to a configuration
+satisfying safe operational constraints. The assumption is shown to hold for
+voltage control in electric power systems and pressure control in water
+distribution networks. Numerical tests corroborate the efficacy of the novel
+scheme.",2103.13505v1
+2021-04-08,"Comment on ""Unconventional enhancement of ferromagnetic interactions in Cd-doped GdFe2Zn20 single crystals studied by ESR and 57Fe Mossbauer spectroscopies""","In the recent publication, Phys. Rev. B 102, 144420 (2020), Cabrera-Baez et
+al. present a study of the effects of Cd-substitution for Zn in the
+ferromagnetic compound GdFe2Zn20. As part of this paper, they claim that for
+GdFe2Zn18.6Cd1.4 the effective moment of Gd is reduced by 25% and the saturated
+moment of Gd is reduced by over 40%. We regrew representative members of the
+GdFe2Zn(20-x)Cdx series and did not find any such reductions. In addition, we
+measured several crystals from the growth batch that was used by Cabrera-Baez
+et al. and did not see such reductions. Although there is a modest increase in
+TC with Cd substitution, there is no significant change in the Gd effective
+moment or the saturated moment associated with the low temperature
+ferromagnetic state.",2104.03770v1
+2021-04-12,A-FMI: Learning Attributions from Deep Networks via Feature Map Importance,"Gradient-based attribution methods can aid in the understanding of
+convolutional neural networks (CNNs). However, the redundancy of attribution
+features and the gradient saturation problem, which weaken the ability to
+identify significant features and cause an explanation focus shift, are
+challenges that attribution methods still face. In this work, we propose: 1) an
+essential characteristic, Strong Relevance, when selecting attribution
+features; 2) a new concept, feature map importance (FMI), to refine the
+contribution of each feature map, which is faithful to the CNN model; and 3) a
+novel attribution method via FMI, termed A-FMI, to address the gradient
+saturation problem, which couples the target image with a reference image, and
+assigns the FMI to the difference-from-reference at the granularity of feature
+map. Through visual inspections and qualitative evaluations on the ImageNet
+dataset, we show the compelling advantages of A-FMI on its faithfulness,
+insensitivity to the choice of reference, class discriminability, and superior
+explanation performance compared with popular attribution methods across
+varying CNN architectures.",2104.05527v1
+2021-04-15,Evolution of Anti-de Sitter black holes in Einstein-Maxwell-dilaton theory,"We study the nonlinear evolution of the spherical symmetric black holes under
+a small neutral scalar field perturbation in Einstein-Maxwell-dilaton theory
+with coupling function $f(\phi)=e^{-b\phi}$ in asymptotic anti-de Sitter
+spacetime. The non-minimal coupling between scalar and Maxwell fields allows
+the transmission of the energy from the Maxwell field to the scalar field, but
+also behaves as a repulsive force for the scalar. The scalar field oscillates
+with damping amplitude and converges to a final value by a power law. The
+irreducible mass of the black hole increases abruptly at initial times and then
+saturates to the final value exponentially. The saturating rate is twice the
+decaying rate of the dominant mode of the scalar. The effects of the black hole
+charge, the cosmological constant and the coupling parameter on the evolution
+are studied in detail. When the initial configuration is a naked singularity
+spacetime with a large charge to mass ratio, a horizon will form soon and hide
+the singularity.",2104.07281v1
+2021-04-15,Cross-beam energy transfer saturation by ion trapping-induced detuning,"The performance of direct-drive inertial confinement fusion implosions relies
+critically on the coupling of laser energy to the target plasma. Cross-beam
+energy transfer (CBET), the resonant exchange of energy between intersecting
+laser beams mediated by ponderomotively driven ion-acoustic waves (IAW),
+inhibits this coupling by scattering light into unwanted directions. The
+variety of beam intersection angles and varying plasma conditions in an
+implosion results in IAWs with a range of phase velocities. Here we show that
+CBET saturates through a resonance detuning that depends on the IAW phase
+velocity and that results from trapping-induced modifications to the ion
+distribution functions. For smaller phase velocities, the modifications to the
+distribution functions can rapidly thermalize in the presence of mid-Z ions,
+leading to a blueshift in the resonant frequency. For larger phase velocities,
+the modifications can persist, leading to a redshift in the resonant frequency.
+Ultimately, these results may reveal pathways towards CBET mitigation and
+inform reduced models for radiation hydrodynamics codes to improve their
+predictive capability.",2104.07725v1
+2021-04-14,Analysis of Screening Effects on Terahertz Photoconductive Devices using a Fully-Coupled Multiphysics Approach,"The terahertz current generated by a photoconductive device (PCD) saturates
+as the power of the input optical pump is increased. This behavior is induced
+by various screening effects that stem from the interactions between
+electromagnetic (EM) fields and semiconductor carriers. In this work, these
+screening effects are numerically analyzed for the first time using a
+fully-coupled multiphysics approach. Unlike the previously developed simulation
+frameworks, this approach rigorously models the nonlinear coupling between the
+EM fields and the carriers and therefore is capable of accounting for the
+screening effects. It is demonstrated that the results obtained using this
+multiphysics approach and actual experiments are in excellent agreement. The
+optical- and radiation-field screening effects are identified in the simulation
+results and the optical-field screening is found to play a more dominant role
+in the saturation of the PCD output under high optical pump power levels.",2105.00820v1
+2021-05-04,Advanced Phase-Change Materials for Enhanced Meta-Displays,"Structural colors generated due to light scattering from static
+all-dielectric metasurfaces have successfully enabled high-resolution,
+high-saturation and wide-gamut color printing applications. Despite recent
+advances, most demonstrations of these structure-dependent colors lack
+post-fabrication tunability that hinders their applicability for front-end
+dynamic display technologies. Phase-change materials (PCMs), with significant
+contrast of their optical properties between their amorphous and crystalline
+states, have demonstrated promising potentials in reconfigurable nanophotonics.
+Herein, we leverage a tunable all-dielectric reflective metasurface made of a
+newly emerged class of low-loss optical PCMs with superb characteristics, i.e.,
+antimony trisulphide (Sb$_2$S$_3$), antimony triselenide (Sb$_2$Se$_3$), and
+binary germanium-doped selenide (GeSe$_3$), to realize switchable,
+high-saturation, high-efficiency and high-resolution structural colors. Having
+polarization sensitive building blocks, the presented metasurface can generate
+two different colors when illuminated by two orthogonally polarized incident
+beams. Such degrees of freedom (i.e., structural state and polarization) enable
+a single reconfigurable metasurface with fixed geometrical parameters to
+generate four distinct wide-gamut colors suitable for a wide range of
+applications, including tunable full-color printing and displays, information
+encryption, and anti-counterfeiting.",2105.01313v1
+2021-05-11,Implicit and semi-implicit second-order time stepping methods for the Richards equation,"This study concerns numerical methods for efficiently solving the Richards
+equation where different weak formulations and computational techniques are
+analyzed. The spatial discretizations are based on standard or mixed finite
+element methods. Different implicit and semi-implicit temporal discretization
+techniques of second-order accuracy are studied. To obtain a linear system for
+the semi-implicit schemes, we propose second-order techniques using
+extrapolation formulas and/or semi-implicit Taylor approximations for the
+temporal discretization of nonlinear terms. A numerical convergence study and a
+series of numerical tests are performed to analyze efficiency and robustness of
+the different schemes. The developed scheme, based on the proposed temporal
+extrapolation techniques and the mixed formulation involving the saturation and
+pressure head and using the standard linear Lagrange element, performs better
+than other schemes based on the saturation and the flux and using the
+Raviart-Thomas elements. The proposed semi-implicit scheme is a good
+alternative when implicit schemes meet convergence issues.",2105.05224v1
+2021-05-20,Optimal Frobenius light cone in spin chains with power-law interactions,"In many-body quantum systems with spatially local interactions, quantum
+information propagates with a finite velocity, reminiscent of the ``light cone""
+of relativity. In systems with long-range interactions which decay with
+distance $r$ as $1/r^\alpha$, however, there are multiple light cones which
+control different information theoretic tasks. We show an optimal (up to
+logarithms) ``Frobenius light cone"" obeying $t\sim r^{\min(\alpha-1,1)}$ for
+$\alpha>1$ in one-dimensional power-law interacting systems with finite local
+dimension: this controls, among other physical properties, the butterfly
+velocity characterizing many-body chaos and operator growth. We construct an
+explicit random Hamiltonian protocol that saturates the bound and settles the
+optimal Frobenius light cone in one dimension. We partially extend our
+constraints on the Frobenius light cone to a several operator $p$-norms, and
+show that Lieb-Robinson bounds can be saturated in at most an exponentially
+small $e^{-\Omega(r)}$ fraction of the many-body Hilbert space.",2105.09960v2
+2021-05-25,Algorithms to generate saturated random sequential adsorption packings built of rounded polygons,"We present the algorithm for generating strictly saturated random sequential
+adsorption packings built of rounded polygons. It can be used to study various
+properties of such packings built of a wide variety of different shapes and in
+modelling monolayers obtained during the irreversible adsorption processes of
+complex molecules. Here, we apply the algorithm to study the densities of
+packings built of rounded regular polygons. Contrary to packings built of
+regular polygons, where packing fraction grows with an increasing number of
+polygon sides, the packing fraction reaches its maximum for packings built of
+rounded regular triangles. With a growing number of polygon sides and
+increasing rounding radius, the packing fractions tend to the limit given by a
+packing built of disks. However, they are still slightly denser, even for the
+rounded 25-gon, which is the highest-sided regular polygon studied here.",2105.11867v1
+2021-05-30,Mackey's obstruction map for discrete graded algebras,"G.W. Mackey's celebrated obstruction theory for projective representations of
+locally compact groups was remarkably generalized by J. M. G. Fell and R. S.
+Doran to the wide area of saturated Banach *-algebraic bundles.
+  Analogous obstruction is suggested here for discrete group graded algebras
+which are not necessarily saturated, i.e. strongly graded in the discrete
+context. The obstruction is a map assigning a certain second cohomology class
+to every equivariance class of absolutely simple graded modules.
+  The set of equivariance classes of such modules is equipped with an
+appropriate multiplication, namely a graded product, such that the obstruction
+map is a homomorphism of abelian monoids. Graded products, essentially arising
+as pull-backs of bundles, admit many nice properties, including a way to twist
+graded algebras and their graded modules.
+  The obstruction class turns out to determine the fine part that appears in
+the Bahturin-Zaicev-Sehgal decomposition, i.e. the graded Artin-Wedderburn
+theorem for graded simple algebras which are graded Artinian, in case where the
+base algebras (i.e. the unit fiber algebras) are finite-dimensional over
+algebraically closed fields.",2105.14585v2
+2021-06-01,Comparing Test Sets with Item Response Theory,"Recent years have seen numerous NLP datasets introduced to evaluate the
+performance of fine-tuned models on natural language understanding tasks.
+Recent results from large pretrained models, though, show that many of these
+datasets are largely saturated and unlikely to be able to detect further
+progress. What kind of datasets are still effective at discriminating among
+strong models, and what kind of datasets should we expect to be able to detect
+future improvements? To measure this uniformly across datasets, we draw on Item
+Response Theory and evaluate 29 datasets using predictions from 18 pretrained
+Transformer models on individual test examples. We find that Quoref, HellaSwag,
+and MC-TACO are best suited for distinguishing among state-of-the-art models,
+while SNLI, MNLI, and CommitmentBank seem to be saturated for current strong
+models. We also observe span selection task format, which is used for QA
+datasets like QAMR or SQuAD2.0, is effective in differentiating between strong
+and weak models.",2106.00840v1
+2021-06-14,Nonclassical states of light in a nonlinear Michelson interferometer,"Nonlinear quantum metrology schemes can lead to faster than Heisenberg
+limited scalings for the measurement uncertainty. We study a Michelson
+interferometer embedded in a Kerr medium [Luis and Rivas, Phys. Rev. A 92,
+022104 (2015)] that leads to non-linear, intensity dependent phase shifts
+corresponding to relative changes in the lengths of its two arms. The quantum
+Cramer-Rao bound on the minimum achievable measurement uncertainties is worked
+out and the requirements, in practice, to saturate the bound are investigated.
+The choice of input state of light into the interferometer and the read out
+strategy at the output end are discussed. The ideal, non-classical states of
+light that must be used to saturate the bound are found to be highly
+susceptible to photon loss noise. We identify optimal states at each noise
+level that are both resilient to noise and capable of giving the enhanced
+sensitivities and discuss practical implementations of the interferometry
+scheme using such states.",2106.07420v2
+2021-06-17,Exploring the Properties and Evolution of Neural Network Eigenspaces during Training,"In this work we explore the information processing inside neural networks
+using logistic regression probes \cite{probes} and the saturation metric
+\cite{featurespace_saturation}. We show that problem difficulty and neural
+network capacity affect the predictive performance in an antagonistic manner,
+opening the possibility of detecting over- and under-parameterization of neural
+networks for a given task. We further show that the observed effects are
+independent from previously reported pathological patterns like the ``tail
+pattern'' described in \cite{featurespace_saturation}. Finally we are able to
+show that saturation patterns converge early during training, allowing for a
+quicker cycle time during analysis",2106.09526v3
+2021-06-18,Decoding the Density Dependence of the Nuclear Symmetry Energy,"The large imbalance in the neutron and proton densities in very neutron rich
+systems increases the nuclear symmetry energy so that it governs many aspects
+of neutron stars and their mergers. Extracting the density dependence of the
+symmetry energy therefore constitutes an important scientific objective. Many
+analyses have been limited to extracting values for the symmetry energy, $S_0$,
+and its ``derivative'', $L$, at saturation density $\rho_0 \approx 2.6 \times
+10^{14}~\mathrm{g/cm^3}$ $\approx 0.16~\mathrm{nucleons/fm^{3}}$, resulting in
+constraints that appear contradictory. We show that most experimental
+observables actually probe the symmetry energy at densities far from $\rho_0$,
+making the extracted values of $S_0$ or $L$ imprecise. By focusing on the
+densities these observables actually probe, we obtain a detailed picture of the
+density dependence of the symmetry energy from $0.25\rho_0$ to $1.5\rho_0$.
+From this experimentally derived density functional, we extract
+$L_{01}=53.1\pm6.1 MeV$ at $\rho \approx 0.10~\mathrm{fm^{-3}}$, a neutron skin
+thickness for $^{208}Pb$ of $R_{np} =$ $0.23\pm0.04$ fm, a symmetry pressure at
+saturation density of $P_0=3.2\pm1.2 MeV/fm^3$ and suggests a radius for a 1.4
+solar mass neutron star of $13.1\pm0.6$ km.",2106.10119v1
+2021-06-23,"Thermodynamics of Wetting, Prewetting and Surface Phase Transitions with Surface Binding","In living cells, protein-rich condensates can wet the cell membrane and
+surfaces of membrane-bound organelles. Interestingly, many phase-separating
+proteins also bind to membranes leading to a molecular layer of bound
+molecules. Here we investigate how binding to membranes affects wetting,
+prewetting and surface phase transitions. We derive a thermodynamic theory for
+a three-dimensional bulk in the presence of a two-dimensional, flat membrane.
+At phase coexistence, we find that membrane binding facilitates complete
+wetting and thus lowers the wetting angle. Moreover, below the saturation
+concentration, binding facilitates the formation of a thick layer at the
+membrane and thereby shifts the prewetting phase transition far below the
+saturation concentration. The distinction between bound and unbound molecules
+near the surface leads to a large variety of surface states {and complex
+surface phase diagrams with a rich topology of phase transitions. Our work
+suggests that surface phase transitions combined with molecular binding
+represent a versatile mechanism to control the formation of protein-rich
+domains at intra-cellular surfaces.",2106.12565v3
+2021-06-26,Probing gluon number density with electron-dijet correlations at EIC,"We propose a novel way of studying the gluon number density (the so-called
+Weizs\""acker-Williams gluon distribution) using the planned Electron Ion
+Collider. Namely, with the help of the azimuthal correlations between the total
+transverse momentum of the dijet system and the scattered electron, we examine
+an interplay between the effect of the soft gluon emissions (the Sudakov form
+factor) and the gluon saturation effects. The kinematic cuts are chosen such
+that the dijet system is produced in the forward direction in the laboratory
+frame, which provides an upper bound on the probed longitudinal fractions of
+the hadron momentum carried by scattered gluons. Further cuts enable us to use
+the factorization formalism that directly involves the unpolarized
+Weizs\""acker-Williams gluon distribution. We find this observable to be very
+sensitive to the soft gluon emission and moderately sensitive to the gluon
+saturation.",2106.13964v2
+2021-06-27,Can a liquid drop on a substrate be in equilibrium with saturated vapor?,"It is well-known that liquid and saturated vapor, separated by a flat
+interface in an unbounded space, are in equilibrium. One would similarly expect
+a liquid drop, sitting on a flat substrate, to be in equilibrium with the vapor
+surrounding it. Yet, it is not: as shown in this work, the drop evaporates.
+Mathematically, this conclusion is deduced using the diffuse-interface model,
+but it can also be reformulated in terms of the maximum-entropy principle,
+suggesting model independence. Physically, evaporation of drops is due to the
+so-called Kelvin effect, which gives rise to a liquid-to-vapor mass flux in all
+cases where the boundary of the liquid phase is convex.",2106.14221v2
+2021-06-27,Capillary condensation of saturated vapor in a corner formed by two intersecting walls,"The dynamics of saturated vapor between two intersecting walls is examined.
+It is shown that, if the angle $\phi$ between the walls is sufficiently small,
+the vapor becomes unstable, and spontaneous condensation occurs in the corner,
+similar to the so-called capillary condensation of vapor into a porous medium.
+As a result, an ever-growing liquid meniscus develops near the corner. The
+diffuse-interface model and the lubrication approximation are used to
+demonstrate that the meniscus grows if and only if $\phi+2\theta<\pi$, where
+$\theta$ is the contact angle corresponding to the fluid/solid combination
+under consideration. This criterion has a simple physical explanation: if it
+holds, the meniscus surface is concave -- hence, the Kelvin effect causes
+condensation. Once the thickness of the condensate exceeds by an order of
+magnitude the characteristic interfacial thickness, the volume of the meniscus
+starts to grow linearly with time. If the near-vertex region of the corner is
+smoothed, the instability can be triggered off only by finite-size
+perturbations, such that include enough liquid to cover the smoothed aria by a
+microscopically-thin liquid film.",2106.14224v4
+2021-07-01,Some products in fusion systems and localities,"The theory of saturated fusion systems resembles in many parts the theory of
+finite groups. However, some concepts from finite group theory are difficult to
+translate to fusion systems. For example, products of normal subsystems with
+other subsystems are only defined in special cases. In this paper the theory of
+localities is used to prove the following result: Suppose $\mathcal{F}$ is a
+saturated fusion system over a $p$-group $S$. If $\mathcal{E}$ is a normal
+subsystem of $\mathcal{F}$ over $T\leq S$, and $\mathcal{D}$ is a subnormal
+subsystem of $N_{\mathcal{F}}(T)$ over $R\leq S$, then there is a subnormal
+subsystem $\mathcal{E}\mathcal{D}$ of $\mathcal{F}$ over $TR$, which plays the
+role of a product of $\mathcal{E}$ and $\mathcal{D}$ in $\mathcal{F}$. If
+$\mathcal{D}$ is normal in $N_{\mathcal{F}}(T)$, then $\mathcal{E}\mathcal{D}$
+is normal in $\mathcal{F}$. It is shown along the way that the subsystem
+$\mathcal{E}\mathcal{D}$ is closely related to a naturally arising product in
+certain localities attached to $\mathcal{F}$.",2107.00301v2
+2021-07-16,Using saturated count models for user-friendly synthesis of categorical data,"Over the past three decades, synthetic data methods for statistical
+disclosure control have continually evolved, but mainly within the domain of
+survey data sets. There are certain characteristics of administrative
+databases, such as their size, which present challenges from a synthesis
+perspective and require special attention. This paper, through the fitting of
+saturated count models, presents a synthesis method that is suitable for
+administrative databases that is tuned by two parameters. The method allows
+large categorical data sets to be synthesized quickly and allows risk and
+utility metrics to be satisfied a priori, that is, prior to synthetic data
+generation. The paper explores how the flexibility afforded by two-parameter
+count models (the negative binomial and Poisson-inverse Gaussian) can be
+utilised to protect respondents' - especially uniques' - privacy in synthetic
+data. Finally, an empirical example is carried out through the synthesis of a
+database which can be viewed as a good substitute to the English School Census.",2107.08062v2
+2021-07-18,Probing gluon density fluctuations at large momentum transfer $|t|$ at HERA,"The information on the gluonic structure and its fluctuations is captured by
+the differential $|t|$ spectrum in diffractive events. The incoherent
+cross-section is sensitive to the fluctuations in the target wavefunction in
+such events. We investigate the incoherent $ep$ cross-section in $J/\psi$
+photoproduction using the impact-parameter dependent dipole model. The spatial
+gluonic structure is modelled as hotspots of gluon density having substructure
+where this substructure is modelled as hotspots within hotspots. We find that
+three levels of the substructure provide a good description of all the data,
+available up to $|t|=30~$GeV$^2$. We investigate these fluctuations in both the
+saturated and non-saturated dipole models and compare our predictions with the
+HERA Data.",2107.08395v2
+2021-07-20,Logarithmic expansion of many-body wave packets in random potentials,"Anderson localization confines the wave function of a quantum particle in a
+one-dimensional random potential to a volume of the order of the localization
+length $\xi$. Nonlinear add-ons to the wave dynamics mimic many-body
+interactions on a mean field level, and result in escape from the Anderson cage
+and in unlimited subdiffusion of the interacting cloud. We address quantum
+corrections to that subdiffusion by (i) using the ultrafast unitary Floquet
+dynamics of discrete-time quantum walks, (ii) an interaction strength ramping
+to speed up the subdiffusion, and (iii) an action discretization of the
+nonlinear terms. We observe the saturation of the cloud expansion of $N$
+particles to a volume $\sim N\xi$. We predict and observe a universal
+intermediate logarithmic expansion regime which connects the mean-field
+diffusion with the final saturation regime and is entirely controlled by
+particle number $N$. The temporal window of that regime grows exponentially
+with the localization length $\xi$.",2107.09385v2
+2021-07-21,Bootstrapping 2d $φ^4$ Theory with Hamiltonian Truncation Data,"We combine the methods of Hamiltonian Truncation and the recently proposed
+generalisation of the S-matrix bootstrap that includes local operators to
+determine the two-particle scattering amplitude and the two-particle form
+factor of the stress tensor at $s>0$ in the 2d $\phi^4$ theory. We use the form
+factor of the stress tensor at $s\le 0$ and its spectral density computed using
+Lightcone Conformal Truncation (LCT), and inject them into the generalized
+S-matrix bootstrap set-up. The obtained results for the scattering amplitude
+and the form factor are fully reliable only in the elastic regime. We
+independently construct the ""pure"" S-matrix bootstrap bounds (bootstrap without
+including matrix elements of local operators), and find that the sinh-Gordon
+model and its analytic continuation the ""staircase model"" saturate these
+bounds. Surprisingly, the $\phi^4$ two-particle scattering amplitude also very
+nearly saturates these bounds, and moreover is extremely close to that of the
+sinh-Gordon/staircase model.",2107.10286v1
+2021-07-22,Bounds on Quantum Information Storage and Retrieval,"We present certain universal bounds on the capacity of quantum information
+storage and on the time scale of its retrieval for a generic quantum field
+theoretic system. The capacity, quantified by the microstate entropy, is
+bounded from above by the surface area of the object measured in units of a
+Goldstone decay constant. The Goldstone bosons are universally present due to
+the spontaneous breaking of Poincare and internal symmetries by the
+information-storing object. Applied to a black hole, the bound reproduces the
+Bekenstein-Hawking entropy. However, the relation goes beyond gravity. The
+minimal time-scale required for retrieving the quantum information from a
+system is equal to its volume measured in units of the same Goldstone scale.
+For a black hole this reproduces the Page time as well as the quantum
+break-time. The same expression for the information retrieval time is shared by
+non-gravitational saturated states in gauge theories, including QCD. The
+saturated objects exhibit some universal signatures such as the emission of
+ultra-soft radiation. Similar bounds apply to non-relativistic many-body
+systems.",2107.10616v1
+2021-08-09,A study of non-linear Langevin dynamics under non-Gaussian noise with quartic cumulant,"We consider a non-linear Langevin equation in presence of non-Gaussian noise
+originating from non-linear bath. We claim, the parameters in the Langevin
+equation are not physical. The physical parameters are obtained from a
+path-integral description of the system, where the Langevin parameters are
+related to the physical parameters by renormalisation flow equations. Then we
+compute both numerically and analytically the velocity two point function and
+show that it saturates to the bath temperature even in presence of
+non-linearity. We also find the velocity four point function numerically and
+show that it saturates to the analytically evaluated thermal velocity four
+point function when the non-linear FDR [1] is satisfied. When the non-linear
+FDR, which is a manifestation of time reversibility of thermal bath, is
+violated then the system does not seem to thermalise. Rather, its velocity four
+point function settles to a steady state.",2108.04284v3
+2021-08-19,"Logarithmic, noise-induced dynamics in the Anderson insulator","We study the dynamical behavior of the Anderson insulator in the presence of
+a local noise. We show that the noise induces logarithmically slow energy and
+entanglement growth, until the system reaches an infinite-temperature state,
+where both quantities saturate to extensive values. The saturation value of the
+entanglement entropy approaches the average entanglement entropy over all
+possible product states. At infinite temperature, we find that a density
+excitation spreads logarithmically with time, without any signs of asymptotic
+diffusive behavior. In addition, we provide a theoretical picture which
+qualitatively reproduces the phenomenology of particle transport.",2108.08861v2
+2021-08-20,2D optical rogue waves affected by transverse carrier diffusion in broad-area semiconductor lasers with a saturable absorber,"Statistics and dynamics of 2D rogue waves in a broad-area semiconductor laser
+with an intracavity saturable absorber are numerically investigated under the
+effect of transverse carrier diffusion. We show that lateral diffusion of
+carriers alters the statistics of rogue waves by enhancing their formation in
+smaller ratios of carrier lifetimes in the active and passive materials while
+suppressing them when the ratio is larger. Temporal dynamics of the emitted
+rogue waves is also studied and shown that finite nonzero transverse carrier
+diffusion coefficient gives them a longer duration. To further approach the
+realistic experimental situation, we also investigated statistics and dynamics
+of rogue waves by simulating a circular disk-shape pump which replaces the flat
+pump profile typically used in numerical simulations of broad-area lasers. We
+show that finite pump shape reduces the number emitted rogue waves per unit
+area for large carrier lifetime ratios and increases that for smaller values of
+the ratio in both below and above laser threshold. Temporal width of the
+emitted rogue waves is also shown to reduce as a consequence of removing the
+nonphysical effects of infinite flat pump on carrier dynamics.",2108.09254v1
+2021-08-26,In vivo functional and structural retina imaging using multimodal photoacoustic remote sensing microscopy and optical coherence tomography,"We have developed a multimodal photoacoustic remote sensing (PARS) microscope
+combined with swept source optical coherence tomography for in vivo,
+non-contact retinal imaging. Building on the proven strength of multiwavelength
+PARS imaging, the system is applied for estimating retinal oxygen saturation in
+the rat retina. The capability of the technology is demonstrated by imaging
+both microanatomy and the microvasculature of the retina in vivo. To our
+knowledge this is the first time a non-contact photoacoustic imaging technique
+is employed for in vivo oxygen saturation measurement in the retina.",2108.12279v1
+2021-08-28,Evaporation-driven density instabilities in saturated porous media,"Soil salinization is a major cause of soil degradation and hampers plant
+growth. For soils saturated with saline water, the evaporation of water induces
+accumulation of salt near the top of the soil. The remaining liquid gets an
+increasingly larger density due to the accumulation of salt, giving a
+gravitationally unstable situation, where instabilities in the form of fingers
+can form. These fingers can hence lead to a net downwards transport of salt. We
+here investigate the appearance of these fingers through a linear stability
+analysis and through numerical simulations. The linear stability analysis gives
+criteria for onset of instabilities for a large range of parameters.
+Simulations using a set of parameters give information also about the
+development of the fingers after onset. With this knowledge we can predict
+whether and when the instabilities occur, and their effect on the salt
+concentration development near the top boundary.",2108.12690v1
+2021-08-30,Predicting the Effect of European Air Traffic on Cirrus Cloud Cover,"The purpose of this study is to provide more insight into the role of
+anthropogenic cirrus formation through air traffic, by investigating the
+high-density European airspace over a period spanning several recent years
+including the start of the COVID-19 pandemic (2015-2020). Several data
+resources are combined, exploiting the strengths of each product within an
+all-encompassing framework on a high spatio-temporal resolution. Data from
+METEOSAT SEVIRI have been combined and validated with CALIPSO's CALIOP data to
+deduce temporal cirrus cloud cover variability over a rectangular region bound
+by (10 degrees W - 35 degrees N) and (40 degrees E - 60 degrees N). Cirrus
+clouds are correlated with air traffic. Meteorology was incorporated into the
+analysis as it is of major influence on the formation and lifetime of cirrus.
+Both a logistic regression model and a Random Forest model were built to assess
+cirrus cloud cover variability imposed by meteorology. The impact of aviation
+on cirrus cover in 1) super-saturated an 2) sub-saturated air have been
+evaluated separately. A description of all the datasets involved, including the
+main research methodology and main results, are presented.",2108.13364v1
+2021-09-08,Subleading Bounds on Chaos,"Chaos, in quantum systems, can be diagnosed by certain out-of-time-order
+correlators (OTOCs) that obey the chaos bound of Maldacena, Shenker, and
+Stanford (MSS). We begin by deriving a dispersion relation for this class of
+OTOCs, implying that they must satisfy many more constraints beyond the MSS
+bound. Motivated by this observation, we perform a systematic analysis
+obtaining an infinite set of constraints on the OTOC. This infinite set
+includes the MSS bound as the leading constraint. In addition, it also contains
+subleading bounds that are highly constraining, especially when the MSS bound
+is saturated by the leading term. These new bounds, among other things, imply
+that the MSS bound cannot be exactly saturated over any duration of time,
+however short. Furthermore, we derive a sharp bound on the Lyapunov exponent
+$\lambda_2 \le \frac{6\pi}{\beta}$ of the subleading correction to maximal
+chaos.",2109.03826v2
+2021-09-16,Stabilization of physical systems via saturated controllers with only partial state measurements,"This paper provides a constructive passivity-based control approach to solve
+the set-point regulation problem for input-affine continuous nonlinear systems
+while considering saturation in the inputs. As customarily in passivity-based
+control, the methodology consists of two steps: energy shaping and damping
+injection. In terms of applicability, the proposed controllers have two
+advantages concerning other passivity-based control techniques: (i) the energy
+shaping is carried out without solving partial differential equations, and (ii)
+the damping injection is performed without measuring the passive output. The
+proposed methodology is suitable to control a broad range of physical systems,
+e.g., mechanical, electrical, and electro-mechanical systems. We illustrate the
+applicability of the technique by designing controllers for systems in
+different physical domains, where we validate the analytical results via
+simulations and experiments.",2109.08111v2
+2021-09-17,Relaxation of saturated random sequential adsorption packings of discorectangles aligned on a line,"Relaxation of the packing of elongated particles (discorectangles) aligned on
+a line was studied numerically. The aspect ratio (length-to-width ratio) for
+the discorectangles was varied within the range $\varepsilon \in [1;50]$. The
+initial jamming (saturated) state was produced using the basic variant of the
+random sequential adsorption (RSA) model with random positions and orientations
+of particles. The relaxation was performed by allowing rotational and
+translational diffusion motions of the particles wile their centers remained
+located on the line. The effects of the aspect ratio $\varepsilon$ on the
+kinetics of relaxation, the orientation order parameter and the distribution
+function of the distances between nearest-neighbor discorectangles were
+analyzed. The transport properties of the resulting 1D systems were also
+analyzed by using the diffusion of a tracer particle (random walker) between
+the nearest-neighbor discorectangles. In the relaxed states the anomalous
+diffusion was observed having a hopping exponent $d_w>2$ dependent upon
+$\varepsilon$.",2109.08453v2
+2021-09-26,Multirate iterative scheme with multiphysics finite element method for a fluid-saturated poroelasticity,"In this paper, we propose a multirate iterative scheme with multiphysics
+finite element method for a fluid-saturated poroelasticity model. Firstly, we
+reformulate the original model into a fluid coupled problem to apply the
+multiphysics finite element method for the discretization of the space
+variables, and we design a multirate iterative scheme on the time scale which
+solve a generalized Stokes problem in the coarse time size and solve the
+diffusion problem in the finer time size according to the characteristics of
+the poroelasticity problem. Secondly, we prove that the multirate iterative
+scheme is stable and the numerical solution satisfies some energy conservation
+laws, which are important to ensure the uniqueness of solution to the decoupled
+computing problem. Also, we analyze the error estimates to prove that the
+proposed numerical method doesn't reduce the precision of numerical solution
+and greatly reduces the computational cost. Finally, we give the numerical
+tests to verify the theoretical results and draw a conclusion to summary the
+main results in this paper.",2109.12726v1
+2021-09-27,Towards Bootstrapping RG flows: Sine-Gordon in AdS,"The boundary correlation functions for a Quantum Field Theory (QFT) in an
+Anti-de Sitter (AdS) background can stay conformally covariant even if the bulk
+theory undergoes a renormalization group (RG) flow. Studying such correlation
+functions with the numerical conformal bootstrap leads to non-perturbative
+constraints that must hold along the entire flow. In this paper we carry out
+this analysis for the sine-Gordon RG flows in AdS$_2$, which start with a free
+(compact) scalar in the UV and end with well-known massive integrable theories
+that saturate many S-matrix bootstrap bounds. We numerically analyze the
+correlation functions of both breathers and kinks and provide a detailed
+comparison with perturbation theory near the UV fixed point. Our bounds are
+often saturated to one or two orders in perturbation theory, as well as in the
+flat-space limit, but not necessarily in between.",2109.13261v1
+2021-09-28,The Impact of Sub-Resolution Porosity on Numerical Simulations of Multiphase Flow,"Sub-resolution porosity (SRP) is an ubiquitous, yet often ignored, feature in
+Digital Rock Physics. It embodies the trade-off between image resolution and
+field-of-view, and it is a direct result of choosing an imaging resolution that
+is larger than the smallest pores in a heterogeneous rock sample. In this
+study, we investigate the impacts of SRP on multiphase flow in porous rocks. To
+do so, we use our newly developed Multiphase Micro-Continuum model to perform
+first-of-a-kind direct numerical simulations of two-phase flow in porous
+samples containing SRP. We show that SRP properties (porosity, permeability,
+wettability) can impact predicted absolute permeabilities, fluid breakthrough
+times, residual saturations, and relative permeabilities by factors of up to 2,
+1.5, 3, and 20, respectively. In particular, our results reveal that SRP can
+function as a persistent connector preventing the formation of isolated wetting
+fluid domains during drainage, thus dramatically increasing relative
+permeabilities to both fluids at low saturations. Overall, our study confirms
+previous evidence that the influence of SRP cannot be disregarded without
+incurring significant errors in numerical predictions or experimental analyses
+of multiphase flow in heterogeneous porous media.",2109.13903v1
+2021-10-03,Minimal Diamond-Saturated Families,"For a given fixed poset $\mathcal P$ we say that a family of subsets of $[n]$
+is $\mathcal P$-saturated if it does not contain an induced copy of $\mathcal
+P$, but whenever we add to it a new set, an induced copy of $\mathcal P$ is
+formed. The size of the smallest such family is denoted by $\text{sat}^*(n,
+\mathcal P)$. For the diamond poset $\mathcal D_2$ (the two-dimensional Boolean
+lattice), Martin, Smith and Walker proved that $\sqrt n\leq\text{sat}^*(n,
+\mathcal D_2)\leq n+1$. In this paper we prove that $\text{sat}^*(n, \mathcal
+D_2)\geq (2\sqrt2-o(1))\sqrt n$. We also explore the properties that a
+diamond-saturated family of size $c\sqrt n$, for a constant $c$, would have to
+have.",2110.01118v4
+2021-10-06,Regularized inverse Brascamp--Lieb inequalities,"Given any (forward) Brascamp--Lieb inequality on euclidean space, a famous
+theorem of Lieb guarantees that gaussian near-maximizers always exist.
+Recently, Barthe and Wolff used mass transportation techniques to establish a
+counterpart to Lieb's theorem for all non-degenerate cases of the inverse
+Brascamp--Lieb inequality. Here we build on work of Chen--Dafnis--Paouris and
+employ heat-flow techniques to understand the inverse Brascamp--Lieb inequality
+for certain regularized input functions, in particular extending the
+Barthe--Wolff theorem to such a setting. Inspiration arose from work of
+Bennett, Carbery, Christ and Tao for the forward inequality, as well as Wolff's
+surprising observation that the gaussian saturation property for the inverse
+Brascamp--Lieb inequality implies the gaussian saturation property for both the
+forward Brascamp--Lieb inequality and Barthe's reverse Brascamp--Lieb
+inequality.",2110.02841v1
+2021-10-14,Synchronization and Balancing around Simple Closed Polar Curves with Bounded Trajectories and Control Saturation,"The problem of synchronization and balancing around simple closed polar
+curves is addressed for unicycle-type multi-agent systems. Leveraging the
+concept of barrier Lyapunov function in conjunction with bounded Lyapunov-like
+curve-phase potential functions, we propose distributed feedback control laws
+and show that the agents asymptotically stabilize to the desired closed curve,
+their trajectories remain bounded within a compact set, and their turn-rates
+adhere to the saturation limits. We also characterize the explicit nature of
+the boundary of this trajectory-constraining set based on the magnitude of the
+safe distance of the exterior boundary from the desired curve. We further
+establish a connection between the perimeters and areas of the
+trajectory-constraining set with that of the desired curve. We obtain bounds on
+different quantities of interest in the post-design analysis and provide
+simulation results to illustrate the theoretical findings.",2110.07248v1
+2021-10-15,Bound-Preserving Finite-Volume Schemes for Systems of Continuity Equations with Saturation,"We propose finite-volume schemes for general continuity equations which
+preserve positivity and global bounds that arise from saturation effects in the
+mobility function. In the case of gradient flows, the schemes dissipate the
+free energy at the fully discrete level. Moreover, these schemes are
+generalised to coupled systems of non-linear continuity equations, such as
+multispecies models in mathematical physics or biology, preserving the bounds
+and the dissipation of the energy whenever applicable. These results are
+illustrated through extensive numerical simulations which explore known
+behaviours in biology and showcase new phenomena not yet described by the
+literature.",2110.08186v3
+2021-10-19,Scission configuration in the self-consistent calculations with neck constraint,"The calculations of the potential energy surface are essential in the
+theoretical description of the fission process. In the constrained
+self-consistent approach, the smooth evolution of nuclear shape is described
+from the ground state until a very elongated one with a narrow neck. In all
+microscopic calculations, the rupture of the neck at scission is associated
+with a substantial change of nuclear matter density distribution and rapid
+energy decrease. In this paper, we show that there is no discontinuity of the
+potential energy surface at scission when multi-constrained calculations are
+applied with the neck constraint. An early rupture of the neck at lower
+quadrupole and octupole moments is discussed as competitive with the
+conventional fission path. We discuss the neck properties in the scission
+configuration. We find that the neck radius in the asymmetric fission mode
+cannot decrease below 2 fm, and the nuclear matter density cannot decrease
+below the saturation density. In the compact fission mode, nuclear density may
+go down to half of the saturation density before the rupture of the neck.",2110.10028v1
+2021-10-19,Chaotic synchronization in optical frequency combs,"Using a discrete mode approach we investigate the intermodal dynamics in a
+frequency comb with nonlinear coupling due to four-wave mixing. In the presence
+of sufficient saturable absorption, phase space collapses into a single state,
+and all modes tightly lock with identical phase. In case of a purely reactive
+nonlinearity, a less constrained locking mechanism emerges, which keeps phase
+differences of neighboring modes loosely bounded and leads to the formation of
+quasi-periodic breathers. Analysis of the underlying nonlinear correlations
+identifies a chaotic synchronization process as the origin of this previously
+unreported locking mechanism. Despite their rather large Lyapunov exponent and
+correlation dimension, the highly chaotic dynamics may be easily overlooked by
+common diagnostic approaches for laser mode-locking. This finding may finally
+explain numerous unexplained reports on laser self mode-locking in the absence
+of an effective saturable absorber mechanism and the formation of
+self-frequency modulated combs in semiconductor lasers.",2110.10045v1
+2021-10-24,Quantitative absorption imaging of optically dense effective two-level systems,"Absorption imaging is a commonly adopted method to acquire, with high
+temporal resolution, spatial information on a partially transparent object. It
+relies on the interference between a probe beam and the coherent response of
+the object. In the low saturation regime, it is well described by a Beer
+Lambert attenuation. In this paper we theoretically derive the absorption of a
+$\sigma$ polarized laser probe by an ensemble of two-level systems in any
+saturation regime. We experimentally demonstrate that the absorption cross
+section in dense $^{87}$Rb cold atom ensembles is reduced, with respect to the
+single particle response, by a factor proportional to the optical density b of
+the medium. To explain this reduction, we developed a model that incorporates,
+in the single particle response, the incoherent electromagnetic background
+emitted by the surrounding ensemble. We show that it qualitatively reproduces
+the experimental results. Our calibration factor that has a universal
+dependence on optical density $b$ for $\sigma$ polarized light : $\alpha$ =
+1.17(9) + 0.255(2)b allows to obtain quantitative and absolute, in situ, images
+of dense quantum systems.",2110.12505v1
+2021-11-02,Supersensitivity of Kerr phase estimation with two-mode squeezed vacuum states,"We analytically investigate the sensitivity of Kerr nonlinear phase
+estimation in a Mach-Zehnder interferometer with two-mode squeezed vacuum
+states. We find that such a metrological scheme could access a sensitivity
+scaling over the Boixo \emph{et al.}'s generalized sensitivity limit [S. Boixo
+\emph{et al}., Phys. Rev. Lett. \textbf{98}, 090401 (2007)], which is saturable
+with celebrated NOON states. We also show that parity detection is a
+quasioptimal measurement which can nearly saturate the quantum Cram\'er-Rao
+bound in the aforementioned situation. Moreover, we further clarify the
+supersensitive performance observed in the above scheme is due to the
+restriction of Boixo \emph{et al}.'s generalized sensitivity limit (BGSL) to
+probe states with fixed photon numbers. To conquer this problem, we generalize
+the BGSL into the case with probe states of a fluctuating number of photons, to
+which our scheme belongs.",2111.01375v2
+2021-11-04,A Hofmann-Mislove theorem for approach spaces,"The Hofmann-Mislove theorem says that the ordered set of open filters of the
+open-set lattice of a sober topological space is isomorphic to the ordered set
+of compact saturated sets (ordered by reverse inclusion) of that space. This
+paper concerns a metric analogy of this result. To this end, the notion of
+compact functions of approach spaces is introduced. Such functions are an
+analog of compact subsets in the enriched context. It is shown that for a sober
+approach space $X$, the metric space of proper open $[0,\infty]$-filters of the
+metric space of upper regular functions of $X$ is isomorphic to the opposite of
+the metric space of inhabited and saturated compact functions of $X$,
+establishing a Hofmann-Mislove theorem for approach spaces.",2111.02665v2
+2021-11-05,Black-Hole-Like Saturons in Gross-Neveu,"It has been argued recently that objects of maximal microstate entropy
+permitted by unitarity, the so-called saturons, have properties similar to
+black holes. We demonstrate the existence of such objects in Gross-Neveu model.
+From the large-$N$ scaling of $S$-matrix, we deduce the connection between the
+entropy of the bound-state and the unitarity of scattering. We observe that
+upon saturation of unitarity, the bound state exhibits a remarkable
+correspondence with a black hole. The scaling of its entropy is identical to
+Bekenstein-Hawking entropy. The saturon decays via Hawking's thermal rate of
+temperature given by the inverse size. The information retrieval time from the
+Gross-Neveu saturon is isomorphic to Page's time. Our observations indicate
+that black hole properties are exhibited by saturated states in simple
+calculable models.",2111.03620v1
+2021-11-28,NoFADE: Analyzing Diminishing Returns on CO2 Investment,"Climate change continues to be a pressing issue that currently affects
+society at-large. It is important that we as a society, including the Computer
+Vision (CV) community take steps to limit our impact on the environment. In
+this paper, we (a) analyze the effect of diminishing returns on CV methods, and
+(b) propose a \textit{``NoFADE''}: a novel entropy-based metric to quantify
+model--dataset--complexity relationships. We show that some CV tasks are
+reaching saturation, while others are almost fully saturated. In this light,
+NoFADE allows the CV community to compare models and datasets on a similar
+basis, establishing an agnostic platform.",2111.14059v1
+2021-11-29,Non-standard entanglement structure of local unitary self-dual models as a saturated situation of repeatability in general probabilistic theories,"We study the entanglement structure, i.e., the structure of quantum composite
+system from operational aspects. The structure is not uniquely determined in
+General Probabilistic Theories (GPTs) even if we impose reasonable postulate
+about local systems. In this paper, we investigate the possibility that the
+standard entanglement structure can be determined uniquely by repeatability of
+measurement processing and its saturated situation called self-duality.
+Surprisingly, self-duality cannot determine the standard entanglement structure
+even if we additionally impose local unitary symmetry assumption. In this
+paper, we show the existence of infinite structures of quantum composite system
+such that it is self-dual with local unitary symmetry. Besides, we also show
+the existence of a structure of quantum composite system such that
+non-orthogonal states in the structure are perfectly distinguishable. In
+addition, as a byproduct, we derive an sufficient condition to achieve the
+detection of the entanglement property with a finite number of parameterized
+minimizations.",2111.15019v3
+2021-12-07,Complexity for Open Quantum System,"We study the complexity for an open quantum system. Our system is a harmonic
+oscillator coupled to a one-dimensional massless scalar field, which acts as
+the bath. Specifically, we consider the reduced density matrix by tracing out
+the bath degrees of freedom for both regular and inverted oscillator and
+computed the complexity of purification (COP) and complexity by using the
+operator-state mapping. We found that when the oscillator is regular the COP
+saturates quickly for both underdamped and overdamped oscillators.
+Interestingly, when the oscillator is underdamped, we discover a kink like
+behaviour for the saturation value of COP with varying damping coefficient. For
+the inverted oscillator, we found a linear growth of COP with time for all
+values of bath-system interaction. However, when the interaction is increased
+the slope of the linear growth decreases, implying that the unstable nature of
+the system can be regulated by the bath.",2112.03955v1
+2021-12-15,Nonlinear intensity dependence of photogalvanics and photoconductance induced by terahertz laser radiation in twisted bilayer graphene close to magic angle,"We report on the observation of the nonlinear intensity dependence of the
+bulk photogalvanic current and photoconductivity in the twisted graphene with
+small twist angles close to the second magical angle. We show that terahertz
+radiation results in the photoresponses, which is caused by indirect optical
+transitions (free carrier absorption), direct interband transitions and optical
+transitions between Moir\'e subbands. The relative contribution of these
+absorption channels depends on the Fermi level position with respect to the
+multiple Moir\'e subbands of the twisted graphene. The interplay of these
+absorption channels results in oscillations of the photoresponses with
+variation of the gate voltage. We show that the photoresponse saturates at high
+intensities. For different absorption channels it has different intensity
+dependencies and saturation intensities. The latter depends non-monotonically
+on the Fermi level position, which is controlled by the gate voltage.",2112.07971v1
+2021-12-15,Laser-lithographically written micron-wide superconducting nanowire single-photon detectors,"We demonstrate the fabrication of micron-wide tungsten silicide
+superconducting nanowire single-photon detectors on a silicon substrate using
+laser lithography. We show saturated internal detection efficiencies with wire
+widths from 0.59$\mu$m to 1.43$\mu$m under illumination at 1550nm. We
+demonstrate both straight wires, as well as meandered structures. Single-photon
+sensitivity is shown in devices up to 4mm in length. Laser-lithographically
+written devices allow for fast and easy structuring of large areas while
+maintaining a saturated internal efficiency for wire width around 1$\mu$m.",2112.07976v1
+2021-12-21,Generalized Few-Shot Semantic Segmentation: All You Need is Fine-Tuning,"Generalized few-shot semantic segmentation was introduced to move beyond only
+evaluating few-shot segmentation models on novel classes to include testing
+their ability to remember base classes. While the current state-of-the-art
+approach is based on meta-learning, it performs poorly and saturates in
+learning after observing only a few shots. We propose the first fine-tuning
+solution, and demonstrate that it addresses the saturation problem while
+achieving state-of-the-art results on two datasets, PASCAL-5i and COCO-20i. We
+also show that it outperforms existing methods, whether fine-tuning multiple
+final layers or only the final layer. Finally, we present a triplet loss
+regularization that shows how to redistribute the balance of performance
+between novel and base categories so that there is a smaller gap between them.",2112.10982v3
+2021-12-23,A formula for symbolic powers,"Let $S$ be a Cohen-Macaulay ring which is local or standard graded over a
+field, and let $I$ be an unmixed ideal that is also generically a complete
+intersection. Our goal in this paper is multi-fold. First, we give a
+multiplicity-based characterization of when an unmixed subideal $J \subseteq
+I^{(m)}$ equals the $m$-th symbolic power $I^{(m)}$ of $I$. Second, we provide
+a saturation-type formula to compute $I^{(m)}$ and employ it to deduce a
+theoretical criterion for when $I^{(m)}=I^m$. Third, we establish an explicit
+linear bound on the exponent that makes the saturation formula effective, and
+use it to obtain lower bounds for the initial degree of $I^{(m)}$. Along the
+way, we prove a conjecture (in fact, a generalized version of it) due to
+Eisenbud and Mazur about ${\rm ann}_S(I^{(m)}/I^m)$, and we propose a
+conjecture connecting the symbolic defect of an ideal to Jacobian ideals.",2112.12588v2
+2022-01-01,On structure theorems and non-saturated examples,"For any minimal system $(X,T)$ and $d\geq 1$ there is an associated minimal
+system $(N_{d}(X), \mathcal{G}_{d}(T))$, where $\mathcal{G}_{d}(T)$ is the
+group generated by $T\times\cdots\times T$ and $T\times T^2\times\cdots\times
+T^{d}$ and $N_{d}(X)$ is the orbit closure of the diagonal under
+$\mathcal{G}_{d}(T)$. It is known that the maximal $d$-step pro-nilfactor of
+$N_d(X)$ is $N_d(X_d)$, where $X_d$ is the maximal $d$-step pro-nilfactor of
+$X$.
+  In this paper, we further study the structure of $N_d(X)$. We show that the
+maximal distal factor of $N_d(X)$ is $N_d(X_{dis})$ with $X_{dis}$ being the
+maximal distal factor of $X$, and prove that as minimal systems $(N_{d}(X),
+\mathcal{G}_{d}(T))$ has the same structure theorem as $(X,T)$. In addition, a
+non-saturated metric example $(X,T)$ is constructed, which is not $T\times
+T^2$-saturated and is a Toeplitz minimal system.",2201.00152v1
+2022-01-24,Novel Nussbaum-Type Function based Safe Adaptive Distributed Consensus Control with Arbitrary Unknown Control Direction,"Existing Nussbaum function based methods on the consensus of multi-agent
+systems require (partial) identical unknown control directions of all agents
+and cause dangerous dramatic control shocks. This paper develops a novel
+saturated Nussbaum function to relax such limitations and proposes a Nussbaum
+function based control scheme for the consensus problem of multi-agent systems
+with arbitrary non-identical unknown control directions and safe control
+progress. First, a novel type of the Nussbaum function with different
+frequencies is proposed in the form of saturated time-elongation functions,
+which provides a more smooth and safer transient performance of the control
+progress. Furthermore, the novel Nussbaum function is employed to design
+distributed adaptive control algorithms for linearly parameterized multi-agent
+systems to achieve average consensus cooperatively without dramatic control
+shocks. Then, under the undirected connected communication topology, all the
+signals of the closed-loop systems are proved to be bounded and asymptotically
+convergent. Finally, two comparative numerical simulation examples are carried
+out to verify the effectiveness and the superiority of the proposed approach
+with smaller control shock amplitudes than traditional Nussbaum methods.",2201.09453v1
+2022-02-05,Saturated absorption spectroscopy of buffer-gas-cooled Barium monofluoride molecules,"We report an experimental investigation on the Doppler-free saturated
+absorption spectroscopy of buffer-gas-cooled Barium monofluoride (BaF)
+molecules in a 4~K cryogenic cell. The obtained spectra with a resolution of
+19~MHz, much smaller than previously observed in absorption spectroscopy,
+clearly resolve the hyperfine transitions. Moreover, we use these
+high-resolution spectra to fit the hyperfine splittings of excited $A(v=0)$
+state and find the hyperfine splitting of the laser-cooling-relevant
+$A^2\Pi_{1/2}(v=0, J=1/2, +)$ state is about 18 MHz, much higher than the
+previous theoretically predicted value. This provides important missing
+information for laser cooling of BaF molecules.",2202.02463v2
+2022-02-08,Using Genetic Programming to Predict and Optimize Protein Function,"Protein engineers conventionally use tools such as Directed Evolution to find
+new proteins with better functionalities and traits. More recently,
+computational techniques and especially machine learning approaches have been
+recruited to assist Directed Evolution, showing promising results. In this
+paper, we propose POET, a computational Genetic Programming tool based on
+evolutionary computation methods to enhance screening and mutagenesis in
+Directed Evolution and help protein engineers to find proteins that have better
+functionality. As a proof-of-concept we use peptides that generate MRI contrast
+detected by the Chemical Exchange Saturation Transfer contrast mechanism. The
+evolutionary methods used in POET are described, and the performance of POET in
+different epochs of our experiments with Chemical Exchange Saturation Transfer
+contrast are studied. Our results indicate that a computational modelling tool
+like POET can help to find peptides with 400% better functionality than used
+before.",2202.04039v2
+2022-02-11,Weight polytopes and saturation of Demazure characters,"For $G$ a reductive group and $T\subset B$ a maximal torus and Borel
+subgroup, Demazure modules are certain $B$-submodules, indexed by elements of
+the Weyl group, of the finite irreducible representations of $G$. In order to
+describe the $T$-weight spaces that appear in a Demazure module, we study the
+convex hull of these weights - the Demazure polytope. We characterize these
+polytopes both by vertices and by inequalities, and we use these results to
+prove that Demazure characters are saturated, in the case that $G$ is simple of
+classical Lie type. Specializing to $G=GL_n$, we recover results of Fink,
+M\'esz\'aros, and St. Dizier, and separately Fan and Guo, on key polynomials,
+originally conjectured by Monical, Tokcan, and Yong.",2202.05405v3
+2022-02-12,Scaling properties of exclusive vector meson production cross section from gluon saturation,"It is already known from phenomenological studies that in exclusive
+deep-inelastic scattering off nuclei there appears to be a scaling behavior of
+vector meson production cross section in both nuclear mass number, $A$, and
+photon virtuality, $Q^{2}$, which is strongly modified due to gluon saturation
+effects. In this work we continue those studies in a realistic setup based upon
+using the Monte Carlo event generator Sar{\em t}re. We make quantitative
+predictions for the kinematics of the Electron-Ion Collider, focusing on this
+$A$ and $Q^{2}$ scaling picture, along with establishing a small region of
+squared momentum transfer, $t$, where there are signs of this scaling that may
+potentially be observed at the EIC. Our results are represented as pseudo-data
+of vector meson production diffractive cross section and/or their ratios, which
+are obtained by parsing data collected by the event generator through smearing
+functions, emulating the proposed detector resolutions for the future EIC.",2202.05981v2
+2022-02-18,Self-Kerr effect across the yellow $\mathrm{Cu_2O}$ Rydberg series,"We investigate the nonlinear refraction induced by Rydberg excitons in
+$\mathrm{Cu_2O}$. Using a high-precision interferometry imaging technique that
+spatially resolves the nonlinear phase shift, we observe significant shifts at
+extremely low laser intensity near each exciton resonance. From this, we derive
+the nonlinear index $\mathrm{n_2}$, present the $\mathrm{n_2}$ spectrum for
+$n\geq 5$ and report large $\mathrm{n_2}$ values of order $10^{-3}$ mm$^2$/mW.
+Moreover, we observe a rapid saturation of the Kerr nonlinearity and find that
+the saturation intensity $\mathrm{I_{sat}}$ decreases as $n^{-7}$. We explain
+this with the Rydberg blockade mechanism, whereby giant Rydberg interactions
+limit the exciton density, resulting in a maximum phase shift of 0.5 rad in our
+setup.",2202.09239v1
+2022-02-27,New efficient algorithms for computing Gröbner bases of saturation ideals (F4SAT) and colon ideals (Sparse-FGLM-colon),"This paper is concerned with linear algebra based methods for solving exactly
+polynomial systems through so-called Gr\""obner bases, which allow one to
+compute modulo the polynomial ideal generated by the input equations. This is a
+topical issue in non-linear algebra and more broadly in computational
+mathematics because of its numerous applications in engineering and computing
+sciences. Such applications often require geometric computing features such as
+representing the closure of the set difference of two solution sets to given
+polynomial systems. Algebraically, this boils down to computing Gr\""obner bases
+of colon and/or saturation polynomial ideals. In this paper, we describe and
+analyze new Gr\""obner bases algorithms for this task and present
+implementations which are more efficient by several orders of magnitude than
+the state-of-the-art software.",2202.13387v2
+2022-03-03,Quantum Entanglement in the Sachdev-Ye-Kitaev Model and its Generalizations,"Entanglement is one of the most important concepts in quantum physics. We
+review recent progress in understanding the quantum entanglement in many-body
+systems using large-$N$ solvable models: the Sachdev-Ye-Kitaev (SYK) model and
+its generalizations. We present the study of entanglement entropy in the
+original SYK Model using three different approaches: the exact diagonalization,
+the eigenstate thermalization hypothesis, and the path-integral representation.
+For coupled SYK models, the entanglement entropy shows linear growth and
+saturation at the thermal value. The saturation is related to replica wormholes
+in gravity. Finally, we consider the steady-state entanglement entropy of
+quantum many-body systems under repeated measurements. The traditional symmetry
+breaking in the enlarged replica space leads to the measurement-induced
+entanglement phase transition.",2203.01513v1
+2022-03-16,Categoricity transfer for short AECs with amalgamation over sets,"Let ${\bf K}$ be an $\mathrm{LS}({\bf K})$-short abstract elementary class
+and assume more than the existence of a monster model (amalgamation over sets
+and arbitrarily large models). Suppose ${\bf K}$ is categorical in some
+$\mu>\mathrm{LS}({\bf K})$, then it is categorical in all $\mu'\geq\mu$. Our
+result removes the successor requirement of $\mu$ made by Grossberg-VanDieren,
+at the cost of using shortness instead of tameness; and of using amalgamation
+over sets instead of over models. It also removes the primes requirement by
+Vasey which assumes tameness and amalgamation over models. As a corollary, we
+obtain an alternative proof of the upward categoricity transfer for first-order
+theories by Morley and Shelah. In our construction, we simplify Vasey's results
+to build a weakly successful frame. This allows us to use Shelah-Vasey's
+argument to obtain primes for sufficiently saturated models. If we replace the
+categoricity assumption by $\mathrm{LS}({\bf K})$-superstability, ${\bf K}$ is
+already excellent for sufficiently saturated models. This sheds light on the
+investigation of the main gap theorem for uncountable first-order theories
+within ZFC.",2203.08956v1
+2022-04-05,Scalable global state synchronization of discrete-time double integrator multi-agent systems with input saturation via linear protocol (Completed Version),"This paper studies scalable global state synchronization of discrete-time
+double integrator multi-agent systems in presence of input saturation based on
+localized information exchange. A scale-free collaborative linear dynamic
+protocols design methodology is developed for discrete-time multi-agent systems
+with both full and partial-state couplings. And the protocol design methodology
+does not need any knowledge of the directed network topology and the spectrum
+of the associated Laplacian matrix. Meanwhile, the protocols are parametric
+based on a parameter set in which the designed protocols can guarantee the
+global synchronization result. Furthermore, the proposed protocol is scalable
+and achieves synchronization for any arbitrary number of agents.",2204.02129v2
+2022-04-10,Nonlinear Optical Limiting with Hybrid Nanostructures of NiCo2O4 and Multiwall Carbon Nanotubes,"Nonlinear optical (NLO) response in terms of reverse saturable absorption
+(RSA) has been exploited extensively for optical limiting. Here, we
+experimentally demonstrate that flower-like hybrid nanostructures of NiCo2O4
+and Multiwall Carbon Nanotubes (NCO@MWCNT) exhibit a strong non-linearity in
+their absorption, specifically an excited state absorption (ESA) induced RSA,
+when exposed to nanosecond laser pulses. We obtain strong nonlinear absorption
+coefficient (\b{eta}) and nonlinear refractive index (n2) in hybrid NCO@MWCNT,
+the values that are 2-times and 2-orders of magnitude higher, respectively
+compared to NCO or MWCNT alone. This offers straightforward application in
+optical limiting with optical limiting (FOL) and optical onset (FON) threshold
+ca. 2-10 times lower than benchmark NLO materials, e.g., graphene, family of
+2-D transition metal dichalcogenides (TMDC) materials and recently established
+NCO. Notably, for femtosecond pumping, NLO response of NCO@MWCNT is dominated
+by saturable absorption (SA) with a week contribution from two photon
+absorption (TPA), arising respectively from MWCNT and NCO. A remarkable sign
+reversal along with a larger amplitude is obtained for n2 thanks to the charge
+transfer from MWCNT to NCO.",2204.04751v1
+2022-04-15,Nuclear matter calculations with the phenomenological three-nucleon interaction,"Employing the concept of three-body radial distribution function and using
+the two-body correlation functions, calculated based on the lowest order
+constrained variational method, we investigated the effect of the three-body
+force (TBF) on the nuclear matter properties, for Argonne and Urbana
+$\it{v_{14}}$ potentials. As such, the results for nuclear matter density,
+incompressibility, energy per nucleon, and symmetry energy are presented at the
+saturation point. The inclusion of a phenomenological TBF resulted in closer
+values of the saturation density, incompressibility, and symmetry energy to the
+empirical ones for the symmetric nuclear matter. This is especially the case
+for the Urbana $\it{v_{14}}$ potential. In addition, an empirically-verified
+parabolic approximation of the interaction energy was utilized to perform an
+approximate study of the nuclear matter with neutron excess. Hence, at
+densities higher than about 0.3~fm$^{-3}$ and for proton-to-neutron density
+ratios close to the symmetric nuclear matter, the inclusion of TBF resulted in
+an extra attraction for the Argonne as compared to the Urbana $\it{v_{14}}$
+potential.",2204.07468v1
+2022-04-27,Theoretical Study of the Enhancement of Light Saturation Phenomena of Krypton at Critical Ionization Photon Energies,"By calculating the correlation between the total photoionization
+cross-section of the ground state of the Kr atom and photon energy, three
+particular photon energies close to the near inner orbital energy of 1.75 keV,
+1.90 keV, and 14.30 keV are determined in this work. The dynamical simulation
+under 17.50 keV photon energy in the experimental conditions is achieved by
+implementing the Monte Carlo method and optimizing the photon flux modeling
+parameters. As a result, our calculated data are more consistent with the
+experimental phenomena. The light saturation phenomenon of Kr at 1.75 keV, 1.90
+keV, 14.30 keV, and 17.50 keV energies is further calculated and researched
+using the optimized photon flux model theory. We statistically compare the main
+ionization paths under those four specific photon energies and calculate the
+population changes of various hollow atoms. The results demonstrate that the
+ratio of hollow atoms produced at the critical ionization photon energy is
+high. Furthermore, the change of position is smooth, showing the significant
+difference between the generation mode of ions with low photon energy and those
+with high photon energy, which has important reference significance for
+studying hollow atoms with medium and high charge states.",2204.12955v2
+2022-04-28,A geometric perspective: experimental evaluation of the quantum Cramer-Rao bound,"The power of quantum sensing rests on its ultimate precision limit,
+quantified by the quantum Cram\'er-Rao bound (QCRB), which can surpass
+classical bounds. In multi-parameter estimation, the QCRB is not always
+saturated as the quantum nature of associated observables may lead to their
+incompatibility. Here we explore the precision limits of multi-parameter
+estimation through the lens of quantum geometry, enabling us to experimentally
+evaluate the QCRB via quantum geometry measurements. Focusing on two- and
+three-parameter estimation, we elucidate how fundamental quantum uncertainty
+principles prevent the saturation of the bound. By linking a metric of
+""quantumness"" to the system geometric properties, we investigate and
+experimentally extract the attainable QCRB for three-parameter estimations.",2204.13777v1
+2022-05-05,Distinctive ionic transport of freshly excised human epileptogenic brain tissue,"Epileptogenic lesions have higher concentrations of sodium than does normal
+brain tissue. Such lesions are palpably recognized by a surgeon and then
+excised in order to eliminate epileptic seizures with their associated abnormal
+electrical behavior. Here we study the frequency-dependent electrical
+conductivities of lesion-laden tissues excised from the brains of epilepsy
+patients. The low-frequency (< 1000 Hz) conductivity of biological tissue
+primarily probes extracellular solvated sodium-cations traveling parallel to
+membranes within regions bounded by blockages. This conductivity rises
+monotonically toward saturation as the frequency surpasses the rate with which
+diffusing solvated sodium cations encounter blockages. We find that saturation
+occurs at dramatically higher frequencies in excised brain tissue containing
+epileptogenic lesions than it does in normal brain tissue. By contrast, such an
+effect is not reported for tumors embedded in other excised biological tissue.
+All told, epileptogenic lesions generate frequency-dependent conductivities
+that differ qualitatively from those of both normal brain tissues and tumors.",2205.02888v1
+2022-05-08,The saturated pairwise interaction Gibbs point process as a joint species distribution model,"In an effort to effectively model observed patterns in the spatial
+configuration of individuals of multiple species in nature, we introduce the
+saturated pairwise interaction Gibbs point process.
+  Its main strength lies in its ability to model both attraction and repulsion
+within and between species, over different scales.
+  As such, it is particularly well-suited to the study of associations in
+complex ecosystems.
+  Based on the existing literature, we provide an easy to implement fitting
+procedure as well as a technique to make inference for the model parameters.
+  We also prove that under certain hypotheses the point process is locally
+stable, which allows us to use the well-known `coupling from the past'
+algorithm to draw samples from the model.
+  Different numerical experiments show the robustness of the model.
+  We study three different ecological datasets, demonstrating in each one that
+our model helps disentangle competing ecological effects on species'
+distribution.",2205.03967v2
+2022-05-15,Saturation for Small Antichains,"For a given positive integer $k$ we say that a family of subsets of $[n]$ is
+$k$-antichain saturated if it does not contain $k$ pairwise incomparable sets,
+but whenever we add to it a new set, we do find $k$ such sets. The size of the
+smallest such family is denoted by $\text{sat}^*(n, \mathcal A_{k})$. Ferrara,
+Kay, Kramer, Martin, Reiniger, Smith and Sullivan conjectured that
+$\text{sat}^*(n, \mathcal A_{k})=(k-1)n(1+o(1))$, and proved this for $k\leq
+4$. In this paper we prove this conjecture for $k=5$ and $k=6$. Moreover, we
+give the exact value for $\text{sat}^*(n, \mathcal A_5)$ and $\text{sat}^*(n,
+\mathcal A_6)$. We also give some open problems inspired by our analysis.",2205.07392v2
+2022-05-16,Peridynamic modeling for impact failure of wet concrete considering the influence of saturation,"In this paper, a modified intermediately homogenized peridynamic (IH-PD)
+model for analyzing impact failure of wet concrete has been presented under the
+configuration of ordinary state-based peridynamic theory. The meso-structural
+properties of concrete are linked to the macroscopic mechanical behavior in the
+IH-PD model, where the heterogeneity of concrete is taken into account, and the
+calculation cost does not increase. Simultaneously, the porosity of concrete is
+considered, which is implemented by deleting the bond between two material
+points, as well as the influence of porosity on the mechanical properties of
+concrete. Moreover, the effective bulk and shear modulus of cement mortar in
+wet concrete (saturated and unsaturated concrete) are calculated respectively.
+The dynamic model for wet concrete is described from three aspects: strength,
+dynamic increase factor, and equation of state. Validation of the proposed
+model is established through analyzing some benchmark tests and comparing with
+the corresponding experiment and other available numerical results.",2205.07555v2
+2022-05-17,Design of saturated boundary control for hyperbolic systems with in-domain disturbances,"Boundary feedback control design is studied for 1D hyperbolic systems with an
+in-domain disturbance and a boundary feedback controller under the effect of
+actuator saturation. Nonlinear semigroup theory is used to prove well-posedness
+of mild solution pairs to the closed-loop system. Sufficient conditions in the
+form of dissipation functional inequalities are derived to establish global
+stability for the closed-loop system and $\mathcal{L}^2$-stability in presence
+of in-domain disturbances. The control design problem is then recast as an
+optimization problem over linear matrix inequality constraints. Numerical
+results are shown to validate the effectiveness of the proposed control design.",2205.08194v1
+2022-05-18,Degenerations and order of graphs realized by finite abelian groups,"Let G_1 and G_2 be two groups. If a group homomorphism \varphi : G_1
+\longrightarrow G_2 maps a \in G_1 into b \in G_2 such that \varphi(a) = b,
+then we say a degenerates to b and if every element of G_1 degenerates to
+elements in G_2, then we say G_1 degenerates to G_2. In this paper, we study
+degeneration in graphs and show that degeneration in groups is a particular
+case of degeneration in graphs. We exhibit some interesting properties of
+degeneration in graphs. We use this concept to present a pictorial
+representation of graphs realized by finite abelian groups. We discus some
+partial orders on the set T_p_1 \dots T_p_n of all graphs realized by finite
+abelian p_r-groups, where each p_r, 1 \leq r \leq n, is a prime number. We show
+that each finite abelian p_r-group of rank n can be identified with saturated
+chains of Young diagrams in the poset T_p_1 \dots T_p_n. We present a
+combinatorial formula which represents the degree of a projective
+representation of a symmetric group. This formula determines the number of
+different saturated chains in T_p_1 \cdots T_p_n and the number of finite
+abelian groups of different orders.",2205.08795v2
+2022-05-22,Moon and background removal algorithm for all-sky imager,"All-sky imagers (ASIs) are used to record auroral activities from the ground
+but are often contaminated by the moon. Here, we studied the THEMIS ASIs data
+and developed an algorithm to eliminate the moon which can be generalized to
+other types of ASIs. With our algorithm, the ASI pixels within the moon's
+surface are typically saturated and thus removed by the algorithm. The ASI
+pixels within the moon's glow are close to but not saturated and thus can be
+calibrated by the algorithm to recover auroral structures within the glow. For
+pixels far away from the moon or when there is no moon, the algorithm preserves
+typical auroral forms, from the transient features of auroral streamers and
+pulsating aurora to more stable features of pre-onset arcs. Note that the
+algorithm does not treat clouds, which is a known limitation.",2205.10882v1
+2022-06-08,Time-dependent and quasi-steady features of fast neutrino-flavor conversion,"Despite the theoretical indication that fast neutrino-flavor conversion (FFC)
+ubiquitously occurs in core-collapse supernova and binary neutron star merger,
+the lack of global simulations has been the greatest obstacle to study their
+astrophysical consequences. In this {\it Letter}, we present large-scale ($50
+{\rm km}$) simulations of FFC in spherical symmetry by using a novel approach.
+We effectively rescale the oscillation scale of FFC by reducing the number of
+injected neutrinos in the simulation box, and then extrapolate back to the case
+of the target density of neutrinos with a convergence study. We find that FFC
+in all models achieves quasi-steady state in the non-linear regime, and its
+saturation property of FFC is universal. We also find that temporal- and
+spatial variations of FFC are smeared out at large radii due to phase
+cancellation through neutrino self-interactions. Finally, we provide a new
+diagnostic quantity, ELN-XLN angular crossing, to assess the non-linear
+saturation of FFC.",2206.04097v3
+2022-06-06,Finite element method modeling of expansion of irradiated rocks: focusing on the minerals,"Finite element method (FEM) modeling of the volumetric expansion phenomenon
+associated with the accumulation of irradiation was performed on rocks in a
+concrete for nuclear power plant. The FEM mesh of sandstone, tuff, and granite
+was created based on microscopic images, and the volumetric expansion due to
+irradiation was calculated. The saturated value of the volume expansion due to
+irradiation accumulation was calculated, and it was shown that the saturated
+value of the volume expansion was well explained by the experimental value. In
+addition, the FEM analysis indicates that irradiation-induced degradation of
+rock propagates through a localized concentration of stress followed by
+fracture with cracks spreading throughout the rock.",2206.07140v1
+2022-06-18,"Absolute frequencies of H13C14N hydrogen cyanide transitions in 1,5 μm region with saturated spectroscopy and sub-kHz scanning laser","The wide span and high density of lines in its rovibrational spectrum render
+hydrogen cyanide a useful spectroscopic media for referencing absolute
+frequencies of lasers in optical communication and dimensional metrology. We
+determined, for the first time to the best of our knowledge, the molecular
+transitions' center frequencies of the H13C14N isotope in the range from 1526
+nm to 1566 nm with 1,3e-10 fractional uncertainty. We investigated the
+molecular transitions with a highly coherent and widely tunable scanning laser
+that was precisely referenced to a Hydrogen maser through an optical frequency
+comb. We demonstrated an approach to stabilize the operational conditions
+needed to maintain the constantly low pressure of the hydrogen cyanide to carry
+out the saturated spectroscopy with the third-harmonic synchronous
+demodulation. We demonstrated approximately a fourtyfold improvement in the
+line centers' resolution compared to the previous result.",2206.09232v2
+2022-06-25,Effects of MAC Parameters on the Performance of IEEE 802.11 DCF in NS-3,"This paper presents the design procedure of the NS-3 script for WLAN that is
+organized according to the hierarchical manner of TCP/IP model. We configure
+all layers by using NS-3 model objects and set and modify the values used by
+objects to investigate the effects of MAC parameters (access mechanism, CWmin,
+CWmax and retry limit) on the performance metrics viz. packet delivery ratio,
+packet lost ratio, aggregated throughput, and average delay. The simulation
+results show that RTS/CTS access mechanism outperforms basic access mechanism
+in saturated state, whereas the MAC parameters have no significant impact on
+network performance in non-saturated state. A higher value of CWmin improves
+the aggregated throughput in expense of average delay. The tradeoff
+relationships among the performance metrics are also observed in results for
+the optimal values of MAC parameters. Our design procedure represents a good
+guideline for new NS-3 users to design and modify script and results greatly
+benefit the network design and management.",2206.12615v1
+2022-06-26,Topological bulk solitons in a nonlinear photonic Chern insulator,"Nonlinearities in lattices with topological band structures can induce
+topological interfaces in the bulk of structures and give rise to bulk solitons
+in the topological bandgaps. Here we study a photonic Chern insulator with
+saturable nonlinearity and show the existence of topological bulk solitons. The
+fundamental bulk solitons exhibit as semi-vortex solitons, where only one
+pseudospin component has a nonzero vorticity. The bulk solitons have equal
+angular momentum at different valleys. This phenomenon is a direct outcome of
+the topology of the linear host lattice and the angular momentum can be changed
+by switching the sign of the nonlinearity. The bulk solitons bifurcate from the
+linear bulk band edge and terminate when their powers saturate. We find that
+these bulk solitons are stable within the whole spectrum range. Moreover, these
+bulk solitons are robust against lattice disorders both from on-site energies
+and hopping amplitudes. Our work extends the study of Chern insulators into the
+nonlinear regime and highlights the interplay between topology and
+nonlinearity.",2206.12865v2
+2022-06-30,Flow correlations from a hydrodynamics model with dynamical freeze-out and initial conditions based on perturbative QCD and saturation,"We extend the applicability of the hydrodynamics, perturbative QCD and
+saturation -based EKRT (Eskola-Kajantie-Ruuskanen-Tuominen) framework for
+ultrarelativistic heavy-ion collisions to peripheral collisions by introducing
+dynamical freeze-out conditions. As a new ingredient compared to the previous
+EKRT computations we also introduce a non-zero bulk viscosity. We compute
+various hadronic observables and flow correlations, including normalized
+symmetric cumulants, mixed harmonic cumulants and flow-transverse momentum
+correlations, and compare them against measurements from the BNL Relativistic
+Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). We
+demonstrate that the inclusion of the dynamical freeze-out and bulk viscosity
+allows a better description of the measured flow coefficients in peripheral
+collisions and enables the use of an extended centrality range when
+constraining the properties of QCD matter in the future.",2206.15207v3
+2022-07-04,Segmentation Guided Deep HDR Deghosting,"We present a motion segmentation guided convolutional neural network (CNN)
+approach for high dynamic range (HDR) image deghosting. First, we segment the
+moving regions in the input sequence using a CNN. Then, we merge static and
+moving regions separately with different fusion networks and combine fused
+features to generate the final ghost-free HDR image. Our motion segmentation
+guided HDR fusion approach offers significant advantages over existing HDR
+deghosting methods. First, by segmenting the input sequence into static and
+moving regions, our proposed approach learns effective fusion rules for various
+challenging saturation and motion types. Second, we introduce a novel memory
+network that accumulates the necessary features required to generate plausible
+details in the saturated regions. The proposed method outperforms nine existing
+state-of-the-art methods on two publicly available datasets and generates
+visually pleasing ghost-free HDR results. We also present a large-scale motion
+segmentation dataset of 3683 varying exposure images to benefit the research
+community.",2207.01229v1
+2022-07-04,Ground state bistability of cold atoms in a cavity,"We experimentally demonstrate an optical bistability between two hyperfine
+atomic ground states, using a single mode of an optical resonator in the
+collective strong coupling regime. Whereas in the familiar case, the bistable
+region is created through atomic saturation, we report an effect between states
+of high quantum purity, which is essential for future information storage. The
+nonlinearity of the transitions arise from cavity-assisted pumping between
+ground states of cold, trapped atoms and the stability depends on the intensity
+of two driving lasers. We interpret the phenomenon in terms of the recent
+paradigm of first-order, driven-dissipative phase transitions, where the
+transmitted and driving fields are understood as the order and control
+parameters, respectively. The saturation-induced bistability is recovered for
+infinite drive in one of the controls. The order of the transition is confirmed
+experimentally by hysteresis in the order parameter when either of the two
+control parameters is swept repeatedly across the bistability region and the
+underlying phase diagram is predicted in line with semiclassical mean-field
+theory.",2207.01724v1
+2022-07-06,Evidence of boron pairs in highly boron laser doped silicon,"Secondary Ions Mass Spectroscopy and Hall effect measurements were performed
+on boron doped silicon with concentration between 0.02 at.% and 12 at.%.
+Ultra-high boron doping was made by saturating the chemisorption sites of a Si
+wafer with BCl3, followed by nanosecond laser anneal (Gas Immersion Laser
+Doping). The boron concentration varies thus nearly linearly with the number of
+process repetitions. However, it is not the case for the hole concentration
+which tends to saturate at high boron concentration. The difference between
+boron and hole concentration increases as the square of boron concentration,
+pointing towards the formation of boron pairs as the dominant contribution to
+the increase of inactive boron.",2207.02520v1
+2022-07-07,Highlight Specular Reflection Separation based on Tensor Low-rank and Sparse Decomposition Using Polarimetric Cues,"This paper is concerned with specular reflection removal based on tensor
+low-rank decomposition framework with the help of polarization information. Our
+method is motivated by the observation that the specular highlight of an image
+is sparsely distributed while the remaining diffuse reflection can be well
+approximated by a linear combination of several distinct colors using a
+low-rank and sparse decomposition framework. Unlike current solutions, our
+tensor low-rank decomposition keeps the spatial structure of specular and
+diffuse information which enables us to recover the diffuse image under strong
+specular reflection or in saturated regions. We further define and impose a new
+polarization regularization term as constraint on color channels. This
+regularization boosts the performance of the method to recover an accurate
+diffuse image by handling the color distortion, a common problem of
+chromaticity-based methods, especially in case of strong specular reflection.
+Through comprehensive experiments on both synthetic and real polarization
+images, we demonstrate that our method is able to significantly improve the
+accuracy of highlight specular removal, and outperform the competitive methods
+to recover the diffuse image, especially in regions of strong specular
+reflection or in saturated areas.",2207.03543v1
+2022-07-08,Cubical models of higher categories without connections,"We prove that each of the model structures for ($n$-trivial, saturated)
+comical sets on the category of marked cubical sets having only faces and
+degeneracies (without connections) is Quillen equivalent to the corresponding
+model structure for ($n$-trivial, saturated) complicial sets on the category of
+marked simplicial sets, as well as to the corresponding comical model
+structures on cubical sets with connections. As a consequence, we show that the
+cubical Joyal model structure on cubical sets without connections is equivalent
+to its analogues on cubical sets with connections and to the Joyal model
+structure on simplicial sets. We also show that any comical set without
+connections may be equipped with connections via lifting, and that this can be
+done compatibly on the domain and codomain of any fibration or cofibration of
+comical sets.",2207.03636v2
+2022-07-22,Planar Laser Induced Fluorescence Mapping of a Carbon Laser Produced Plasma,"We present measurements of ion velocity distribution profiles obtained by
+laser induced fluorescence (LIF) on an explosive laser produced plasma (LPP).
+The spatio-temporal evolution of the resulting carbon ion velocity distribution
+was mapped by scanning through the Doppler-shifted absorption wavelengths using
+a tunable, diode-pumped laser. The acquisition of this data was facilitated by
+the high repetition rate capability of the ablation laser (1 Hz) which allowed
+the accumulation of thousand of laser shots in short experimental times. By
+varying the intensity of the LIF beam, we were able to explore the effects of
+fluorescence power against laser irradiance in the context of evaluating the
+saturation versus the non-saturation regime. The small beam size of the LIF
+beam led to high spatial resolution of the measurement compared to other ion
+velocity distribution measurement techniques, while the fast-gated operation
+mode of the camera detector enabled the measurement of the relevant electron
+transitions.",2207.10843v1
+2022-07-31,Symmetry Regularization and Saturating Nonlinearity for Robust Quantization,"Robust quantization improves the tolerance of networks for various
+implementations, allowing reliable output in different bit-widths or fragmented
+low-precision arithmetic. In this work, we perform extensive analyses to
+identify the sources of quantization error and present three insights to
+robustify a network against quantization: reduction of error propagation, range
+clamping for error minimization, and inherited robustness against quantization.
+Based on these insights, we propose two novel methods called symmetry
+regularization (SymReg) and saturating nonlinearity (SatNL). Applying the
+proposed methods during training can enhance the robustness of arbitrary neural
+networks against quantization on existing post-training quantization (PTQ) and
+quantization-aware training (QAT) algorithms and enables us to obtain a single
+weight flexible enough to maintain the output quality under various conditions.
+We conduct extensive studies on CIFAR and ImageNet datasets and validate the
+effectiveness of the proposed methods.",2208.00338v1
+2022-08-12,Direct Route to Thermodynamic Uncertainty Relations and Their Saturation,"Thermodynamic uncertainty relations (TURs) bound the dissipation in
+non-equilibrium systems from below by fluctuations of an observed current.
+Contrasting the elaborate techniques employed in existing proofs, we here prove
+TURs directly from the Langevin equation. This establishes the TUR as an
+inherent property of overdamped stochastic equations of motion. In addition, we
+extend the transient TUR to currents and densities with explicit
+time-dependence. By including current-density correlations we, moreover, derive
+a new sharpened TUR for transient dynamics. Our arguably simplest and most
+direct proof, together with the new generalizations, allows us to
+systematically determine conditions under which the different TURs saturate and
+thus allows for a more accurate thermodynamic inference. Finally we outline the
+direct proof also for Markov jump dynamics.",2208.06402v4
+2022-08-17,Direct calculation of the planar NaCl-aqueous solution interfacial free energy at the solubility limit,"Salty water is the most abundant electrolyte aqueous mixture on Earth,
+however, very little is known about the NaCl-saturated solution interfacial
+free energy. Here, we provide the first direct estimation of this magnitude for
+several NaCl crystallographic planes by means of the Mold Integration
+technique, a highly efficient computational method to evaluate interfacial free
+energies with anisotropic crystal resolution. Making use of the JC-SPC/E model,
+one of the most benchmarked force fields for NaCl/water solutions, we measure
+the interfacial free energy of four different planes, (100), (110), (111), and
+(11-2) with the saturated solution at normal conditions. We find high
+anisotropy between the different crystal orientations with values ranging from
+100 to 150 mJ/m2 and the average value of the distinct planes being 137(20)
+mJ/m2. This value for the coexistence interfacial free energy is in reasonable
+agreement with previous extrapolations from nucleation studies. Our work
+represents a milestone in the computational calculation of interfacial free
+energies between ionic crystals and aqueous solutions.",2208.08322v3
+2022-08-18,Ultra-Efficient DC-gated all-optical graphene switch,"The ultrafast response and broadband absorption of all-optical graphene
+switches are highly desirable features for on-chip photonic switching. However,
+because graphene is an atomically thin material, its absorption of guided
+optical modes is relatively low, resulting in high saturation thresholds and
+switching energies for these devices. To boost the absorption of graphene, we
+present a practical design of an electrically-biased all-optical graphene
+switch that is integrated into silicon slot waveguides, which strongly confine
+the optical mode in the slotted region and enhance its interaction with
+graphene. Moreover, the design incorporates a silicon slab layer and a hafnia
+dielectric layer to electrically tune the saturation threshold and the
+switching energy of the device by applying DC voltages of <0.5 V. Using this
+device, a high extinction ratio (ER) of 10.3dB, a low insertion loss (IL) of
+<0.7dB, and an ultra-efficient switching energy of 79fJ/bit at 0.23V bias are
+attainable for a 40um long switch. The reported performance metrics for this
+device are highly promising and are expected to serve the needs of
+next-generation photonic computing systems.",2208.08610v1
+2022-08-29,Dynamic RF Beam Codebook Reduction for Cost-Efficient mmWave Full-Duplex Systems,"The recent attempts to realize full-duplex (FD) communications in millimeter
+wave (mmWave) systems have garnered a significant amount of interest for its
+potential. In this paper, we present a cost-efficient design of mmWave FD
+systems, where the system dynamically reduces the RF beam codebook in a
+computationally efficient manner, so that it is comprised of the RF beams that
+will prevent the Rx receive chain from saturating due to the self-interference
+(SI). The analog beamformer will suppress the SI to the level that the residual
+SI can be completely removed with digital SI cancellation, allowing the digital
+beamformer to concentrate on the desired channel, free of the SI. To reduce the
+computation required for the proposed method, we propose two sufficient
+conditions that prevent the Rx side saturations, which are practically tight.
+Through performance valuations conducted in realistically modeled mmWave FD
+scenarios, we demonstrate that the proposed design achieves comparable
+performance with the ideal FD and other benchmarks with significantly lower
+costs.",2208.13547v1
+2022-08-30,Geometric scaling in leading neutron events at HERA,"This analysis provides new fits of the GBW model and the impact
+parameter-dependent saturation model (bSat or IP-Sat) to the leading neutron
+structure function HERA data in one pion exchange approximation. Both
+parametrizations of the dipole cross section provide good descriptions of the
+considered data. It is shown here for the first time that the experimental
+leading neutron production HERA data exhibits geometric scaling, which in this
+context means that the total $\gamma^* \pi^*$ cross section is a function of
+only one dimensionless variable $\tau = Q^2/Q_s^2(x)$. The geometric scaling
+region extends over a broad range of $Q^2$ and can be attributed to the
+presence of a saturation boundary which manifests at $Q^2\geq Q^2_s$. The
+scaling behaviour in leading neutron events is profoundly similar to what has
+been observed for the inclusive DIS events.",2208.14200v1
+2022-09-03,Understanding the Quality Factor of Mass-Loaded Tensioned Resonators,"Mechanical resonators featuring large tensile stress have enabled a range of
+experiments in quantum optomechanics and novel sensing. Many sensing
+applications require functionalizing tensioned resonators by appending
+additional mass to them. However, this may dramatically change the resonator
+mode quality factor, and hence its sensitivity. In this work, we investigate
+the effect of the crossover from no mass load to a large mass load on the mode
+shape and quality factor of a tensioned resonator. We show through an
+analytical model and finite element analysis that as the load mass increases,
+surprisingly, the resonator mode shape becomes independent of the exact load
+mass, and therefore, its quality factor saturates. We validate this saturation
+effect experimentally by measuring the quality factor of a silicon nitride
+trampoline resonator while varying the load mass in a controlled manner.",2209.01488v1
+2022-09-06,Massive neutron stars with small radii in relativistic mean-field models optimized to nuclear ground states,"We present an equation of state (EoS) for neutron stars using the
+relativistic mean-field model with isoscalar- and isovector-meson mixing.
+Taking into account the results of the neutron skin thickness, $R_{\rm skin}$,
+of $^{208}$Pb reported by the PREX collaboration, the dimensionless tidal
+deformability of a canonical neutron star observed from GW170817, and a $2.6$
+$M_{\odot}$ compact star implied by the secondary component of GW190814, a new
+effective interaction is constructed so as to reproduce the saturation
+condition of nuclear matter and the ground-state properties of finite,
+closed-shell nuclei. We find that the neutron star EoS exhibits the rapid
+stiffening around twice the nuclear saturation density, which is caused by the
+soft nuclear symmetry energy, $E_{\rm sym}$. It is also noticeable that the
+thick $R_{\rm skin}$ from the PREX-2 experiment can be achieved with the small
+slope parameter of $E_{\rm sym}$ stemming from the isoscalar-meson mixing.
+Thus, we speculate that the secondary component of GW190814 is the heaviest
+neutron star ever discovered.",2209.02861v1
+2022-09-15,Optimal control for maximally creating and maintaining a superposition state of a two-level system under the influence of Markovian decoherence,"Reducing decoherence is an essential step toward realizing general-purpose
+quantum computers beyond the present noisy intermediate-scale quantum (NISQ)
+computers. To this end, dynamical decoupling (DD) approaches in which external
+fields are applied to qubits are often adopted. We numerically study DD using a
+two-level model system (qubit) under the influence of Markovian decoherence by
+using quantum optimal control theory with slightly modified settings, in which
+the physical objective is to maximally create and maintain a specified
+superposition state in a specified control period. An optimal pulse is
+numerically designed while systematically varying the values of dephasing,
+population decay, pulse fluence, and control period as well as using two kinds
+of objective functionals. Although the decrease in purity due to the
+decoherence gives rise to the upper limit of the target expectation value,
+i.e., the saturated value, the optimally shaped pulse effectively deals with
+the decoherence by gradually creating the target superposition state to realize
+the saturated value as much as possible.",2209.07062v2
+2022-09-19,Transverse momentum broadening from NLL BFKL to all orders in pQCD,"We study, to all orders in perturbative QCD, the universal behavior of the
+saturation momentum $Q_s(L)$ controlling the transverse momentum distribution
+of a fast parton propagating through a dense QCD medium with large size $L$.
+Due to the double logarithmic nature of the quantum evolution of the saturation
+momentum, its large $L$ asymptotics is obtained by slightly departing from the
+double logarithmic limit of either next-to-leading log (NLL) BFKL or leading
+order DGLAP evolution equations. At fixed coupling, or in conformal
+$\mathcal{N}=4$ SYM theory, we derive the large $L$ expansion of $Q_s(L)$ up to
+order $\alpha_s^{3/2}$. In QCD with massless quarks, where conformal symmetry
+is broken by the running of the strong coupling constant, the one-loop QCD
+$\beta$-function fully accounts for the universal terms in the $Q_s(L)$
+expansion. Therefore, the universal coefficients of this series are known
+exactly to all orders in $\alpha_s$.",2209.08900v1
+2022-09-30,Quantum Discord and Logarithmic Negativity in the Generalized n-qubit Werner State,"Quantum Discord (QD) is a measure of the total quantum non-local correlations
+of a quantum system. The formalism of quantum discord has been applied to
+various two-qubit mixed states and it has been reported that there is a
+non-zero quantum discord even when the states are unentangled. To this end, we
+have calculated the Quantum Discord for higher than two qubit mixed state, that
+is, the generalized n-qubit Werner state with a bipartite split. We found that
+the QD saturates to a straight line with unit slope in the thermodynamic limit.
+Qualitative studies of entanglement between the two subsystems using
+logarithmic negativity revealed that the entanglement content between them
+increases non-uniformly with the number of qubits leading to its saturation. We
+have proved the above claims both analytically and numerically.",2210.00096v1
+2022-10-03,Data Budgeting for Machine Learning,"Data is the fuel powering AI and creates tremendous value for many domains.
+However, collecting datasets for AI is a time-consuming, expensive, and
+complicated endeavor. For practitioners, data investment remains to be a leap
+of faith in practice. In this work, we study the data budgeting problem and
+formulate it as two sub-problems: predicting (1) what is the saturating
+performance if given enough data, and (2) how many data points are needed to
+reach near the saturating performance. Different from traditional
+dataset-independent methods like PowerLaw, we proposed a learning method to
+solve data budgeting problems. To support and systematically evaluate the
+learning-based method for data budgeting, we curate a large collection of 383
+tabular ML datasets, along with their data vs performance curves. Our empirical
+evaluation shows that it is possible to perform data budgeting given a small
+pilot study dataset with as few as $50$ data points.",2210.00987v1
+2022-10-05,Spectral broadening from turbulence in multiscale lower hybrid current drive simulations,"The scattering of lower hybrid (LH) waves due to scrape-off layer (SOL)
+filaments is investigated. It is revealed that scattering can account for the
+LH spectral gap without any ad hoc modification to the wave-spectrum. This is
+shown using a multiscale simulation approach which allows, for the first time,
+the inclusion of full-wave scattering physics in ray-tracing/Fokker-Planck
+calculations. In this approach, full-wave scattering probabilities are
+calculated for a wave interacting with a statistical ensemble of filaments.
+These probabilities are coupled to ray-tracing equations using radiative
+transfer (RT) theory. This allows the modeling of scattering along the entire
+ray-trajectory, which can be important in the multi-pass regime. Simulations
+are conducted for lower hybrid current drive (LHCD) in Alcator C-Mod, resulting
+in excellent agreement with experimental current and hard X-ray (HXR) profiles.
+A region in filament parameter space is identified in which the impact of
+scattering on LHCD is saturated. Such a state coincides with experimental LHCD
+measurements, suggesting saturation indeed occurs in C-Mod, and therefore the
+exact statistical properties of the filaments are not important.",2210.02344v2
+2022-10-05,Structure of saturated RSA ellipse packings,"Motivated by the recent observation of liquid glass in suspensions of
+ellipsoidal colloids, we examine the structure of (asymptotically) saturated
+RSA ellipse packings. We determine the packing fractions $\phi_{\rm s}(\alpha)$
+to high precision, finding an empirical analytic formula that predicts
+$\phi_{\rm s}(\alpha)$ to within less than $0.1\%$ for all $\alpha \leq 10$.
+Then we explore how these packings' positional-orientational order varies with
+$\alpha$. We find a transition from tip/side- to side/side-contact-dominated
+structure at $\alpha = \alpha_{\rm TS} \simeq 2.4$. At this aspect ratio, the
+peak value $g_{\rm max}$ of packings' positional-orientational paircorrelation
+functions is minimal, and systems can be considered maximally locally
+disordered. For smaller (larger) $\alpha$, $g_{\rm max}$ increases
+exponentially with deceasing (increasing) $\alpha$. Local nematic order and
+structures comparable to the precursor domains observed in experiments
+gradually emerge as $\alpha$ increases beyond $3$. For $\alpha \gtrsim 5$,
+single-layer lamellae become more prominent, and long-wavelength density
+fluctuations increase with $\alpha$ as packings gradually approach the rod-like
+limit.",2210.02388v2
+2022-10-10,Intermodulation Distortion in a Josephson Traveling Wave Parametric Amplifier,"Josephson traveling wave parametric amplifiers enable the amplification of
+weak microwave signals close to the quantum limit with large bandwidth, which
+has a broad range of applications in superconducting quantum computing and in
+the operation of single-photon detectors. While the large bandwidth allows for
+their use in frequency-multiplexed detection architectures, an increased number
+of readout tones per amplifier puts more stringent requirements on the dynamic
+range to avoid saturation. Here, we characterize the undesired mixing processes
+between the different frequency-multiplexed tones applied to a Josephson
+traveling wave parametric amplifier, a phenomenon also known as intermodulation
+distortion. The effect becomes particularly significant when the amplifier is
+operated close to its saturation power. Furthermore, we demonstrate that
+intermodulation distortion can lead to significant crosstalk and reduction of
+fidelity for multiplexed readout of superconducting qubits. We suggest using
+large detunings between the pump and signal frequencies to mitigate crosstalk.
+Our work provides insights into the limitations of current Josephson traveling
+wave parametric amplifiers and highlights the importance of performing further
+research on these devices.",2210.04799v1
+2022-10-13,Self-Supervised Learning of Linear Precoders under Non-Linear PA Distortion for Energy-Efficient Massive MIMO Systems,"Massive multiple input multiple output (MIMO) systems are typically designed
+under the assumption of linear power amplifiers (PAs). However, PAs are
+typically most energy-efficient when operating close to their saturation point,
+where they cause non-linear distortion. Moreover, when using conventional
+precoders, this distortion coherently combines at the user locations, limiting
+performance. As such, when designing an energy-efficient massive MIMO system,
+this distortion has to be managed. In this work, we propose the use of a neural
+network (NN) to learn the mapping between the channel matrix and the precoding
+matrix, which maximizes the sum rate in the presence of this non-linear
+distortion. This is done for a third-order polynomial PA model for both the
+single and multi-user case. By learning this mapping a significant increase in
+energy efficiency is achieved as compared to conventional precoders and even as
+compared to perfect digital pre-distortion (DPD), in the saturation regime.",2210.07037v1
+2022-10-17,Scattering-induced splitting of solitons in the discrete NLS equation with saturable nonlinearity,"We study systematically the scattering of solitons on localized impurities in
+the discrete nonlinear Schr\""odinger (DNLS) equation with a saturable
+nonlinearity. We show that, apart from the generic scenario of the outcome of
+the scattering process, namely the emergence of a reflected and a transmitted
+soliton, other effects can occur. In particular, it is found that, in the case
+of an attractive impurity, a soliton trapped at the impurity can coexist with
+the reflected and transmitted ones. This effect, which resembles the behaviour
+of a quantum particle interacting with a narrow impurity, has not previously
+reported for discrete setting. Parameter regimes are explored for determining
+soliton splitting on the impurity with special attention to equal soliton
+splitting.",2210.09450v1
+2022-10-24,A Theory of Stable Market Segmentations,"We consider a monopolistic seller in a market that may be segmented. The
+surplus of each consumer in a segment depends on the price that the seller
+optimally charges, which depends on the set of consumers in the segment. We
+study which segmentations may result from the interaction among consumers and
+the seller. Instead of studying the interaction as a non-cooperative game, we
+take a reduced-form approach and introduce a notion of stability that any
+resulting segmentation must satisfy. A stable segmentation is one that, for any
+alternative segmentation, contains a segment of consumers that prefers the
+original segmentation to the alternative one. Our main result characterizes
+stable segmentations as efficient and saturated. A segmentation is saturated if
+no consumers can be shifted from a segment with a high price to a segment with
+a low price without the seller optimally increasing the low price. We use this
+characterization to constructively show that stable segmentations always exist.
+Even though stable segmentations are efficient, they need not maximize average
+consumer surplus, and segmentations that maximize average consumer surplus need
+not be stable. Finally, we relate our notion of stability to solution concepts
+from cooperative game theory and show that stable segmentations satisfy many of
+them.",2210.13194v1
+2022-11-09,The Mathematical Theory Of Diffusion In Solids: Time Dependent First Kind Boundary Conditions,"A new solution to the mono-dimensional diffusion equation for time-variable
+first kind boundary condition is presented where the time-variable function at
+the surface is derived proposing a surface saturation model. This solution may
+be helpful in the treatment of diffusion processes where the overall time of
+diffusion is comparable with the time taken by the surface of the solid body to
+saturate achieving a dynamical equilibrium between the diffusing elements
+supplied by the external source and the ones transferred internally through the
+diffusion kinetic mechanisms. Worked examples for constant diffusion
+coefficient are presented and discussed.",2211.05065v5
+2022-11-10,NLO computation of diffractive di-hadron production in a saturation framework,"The cross-sections of diffractive double hadron photo- or electroproduction
+with large $p_T$, on a nucleon or a nucleus, are calculated to NLO accuracy. A
+hybrid formalism mixing collinear factorization and high energy small-$x$
+factorization, more precisely the shockwave formalism for the latter, is used
+to derive the results. The cancellation of divergences is explicitly shown, and
+the finite parts of the NLO differential cross-sections are found. We work in
+arbitrary kinematics such that both photoproduction and leptoproduction are
+considered. The results are therefore usable, to detect saturation effects, at
+both the future EIC or already at LHC, using Ultra Peripheral Collisions.",2211.05774v2
+2022-11-15,On the sound velocity bound in neutron stars,"It has been suggested in the literature that the sound velocity of the
+nuclear matter $v_s$ violates the so-called sound velocity bound $v_s \le
+c/\sqrt{3}$ at high density, where $c$ is the speed of light. In this paper, we
+revisit this issue and confront the current measurements of mass, radius, and
+tidal deformability of neutron stars with $10^5$ different equations of state
+which are parametrized at low density and saturates the sound velocity bound
+beyond twice the saturation density where the equation of state has not been
+constrained yet, by which we can conservatively obtain the maximum mass of the
+neutron stars compatible both with the observed properties of neutron stars and
+the sound velocity bound. We find that majority of the models are eliminated by
+the incompatibility with the observations and, especially, the recently
+detected massive pulsar ($2.35\pm 0.17 M_\odot$) is hardly realized by our
+simulations. Our study strongly supports the violation of the sound velocity
+bound.",2211.07874v1
+2022-11-16,Absolute frequency measurement of the $6s^2~^1S_0 \to 6s6p~^3P_1$ $F=3/2\to F'=5/2$ $^{\text{201}}$Hg transition with background-free saturation spectroscopy,"We report the development of a method for eliminating background-induced
+systematic shifts affecting precise measurements of saturation absorption
+signals. With this technique, we measured the absolute frequency of the
+$6s^2~^1\text{S}_0 \to 6s6p~^3\text{P}_1$ transition in $^{201a}\text{Hg}$
+($F=3/2\to F'=5/2$) to be $1181541111051(83)$~kHz. The measurement was
+referenced with an optical frequency comb synchronized to the frequency of the
+local representation of the UTC. This specific atomic line is situated on the
+steep slope of the Doppler background at room temperature, which results in
+frequency systematic shift. We determined the dependence of this shift on the
+properties of both the spectral line and the background of the measured signal.",2211.09197v1
+2022-11-17,Measurement uncertainty relation for three observables,"In this work we establish rigorously a measurement uncertainty relation (MUR)
+for three unbiased qubit observables, which was previously shown to hold true
+under some presumptions. The triplet MUR states that the uncertainty, which is
+quantified by the total statistic distance between the target observables and
+the jointly implemented observables, is lower bounded by an incompatibility
+measure that reflects the joint measurement conditions. We derive a necessary
+and sufficient condition for the triplet MUR to be saturated and the
+corresponding optimal measurement. To facilitate experimental tests of MURs we
+propose a straightforward implementation of the optimal joint measurements. The
+exact values of incompatibility measure are analytically calculated for some
+symmetric triplets when the corresponding triplet MURs are not saturated. We
+anticipate that our work may enrich the understanding of quantum
+incompatibility in terms of MURs and inspire further applications in quantum
+information science. This work presents a complete theory relevant to a
+parallel work [Y.-L. Mao, et al., Testing Heisenberg's measurement uncertainty
+relation of three observables, arXiv:2211.09389] on experimental tests.",2211.09816v3
+2022-11-19,Robust mode-locking in a hybrid ultrafast laser based on nonlinear multimodal interference,"We experimentally demonstrate the realization of a
+half-polarization-maintaining (half-PM) fiber laser, in which mode-locking is
+provided by a reflective multimode-interference saturable absorber (SA). In the
+specially designed SA, linearly polarized light is coupled into a 15-cm-long
+graded-index multimode fiber (GIMF) through the PM fiber, and then reflected
+back to the PM structure through a mirror pigtailed with a single-mode fiber
+(SMF). The modulation depth and saturation peak power are measured to be 1.5%
+and 0.6 W, respectively. The proposed SA device is incorporated into a novel
+half-PM erbium-doped fiber oscillator, which generates soliton pulses with 409
+fs temporal duration at a 33.3 MHz repetition rate. The proposed fiber laser is
+compared with a conventional non-PM fiber laser mode-locked by nonlinear
+polarization evolution (NPE) in terms of optical properties such as spectral
+bandwidth, pulse duration, and stability performance. Short- and long-time
+stability tests and superior noise performance corroborate robust mode-locking
+in this setup.",2211.10600v1
+2022-11-20,"The weak saturation number of $\boldsymbol{K_{2, t}}$","For two graphs $G$ and $F$, we say that $G$ is weakly $F$-saturated if $G$
+contains no copy of $F$ as a subgraph and one could join all the nonadjacent
+pairs of vertices of $G$ in some order so that a new copy of $F$ is created at
+each step. The weak saturation number $\mathrm{wsat}(n, F)$ is the minimum
+number of edges of a weakly $F$-saturated graph on $n$ vertices. In this paper,
+we examine $\mathrm{wsat}(n, K_{s, t})$, where $K_{s, t}$ is the complete
+bipartite graph with parts of sizes $s$ and $ t $.
+  We determine $\mathrm{wsat}(n, K_{2, t})$, correcting a previous report in
+the literature. It is also shown that $\mathrm{wsat}(s+t,
+K_{s,t})=\binom{s+t-1}{2}$ if $\gcd(s, t)=1$ and $\mathrm{wsat}(s+t,
+K_{s,t})=\binom{s+t-1}{2}+1$, otherwise.",2211.10939v3
+2022-11-23,MPMICE: A hybrid MPM-CFD model for simulating coupled problems in porous media. Application to earthquake-induced submarine landslides,"In this paper, we describe a soil-fluid-structure interaction model that
+combines soil mechanics (saturated sediments), fluid mechanics (seawater or
+air), and solid mechanics (structures). The formulation combines the Material
+Point Method, which models large deformation of the porous media and the
+structure, with the Implicit Continuous-fluid Eulerian, which models complex
+fluid flows. We validate the model and simulate the whole process of
+earthquake-induced submarine landslides. We show that this model captures
+complex interactions between saturated sediment, seawater, and structure, so we
+can use the model to estimate the impact of potential submarine landslides on
+offshore structures.",2211.12761v1
+2022-11-25,Free volume theory explains the unusual behavior of viscosity in a non-confluent tissue during morphogenesis,"A recent experiment on zebrafish blastoderm morphogenesis showed that the
+viscosity ({\eta}) of a non-confluent embryonic tissue grows sharply until a
+critical cell packing fraction ({\phi}S). The increase in {\eta} up to {\phi}S
+is similar to the behavior observed in several glass-forming materials, which
+suggests that the cell dynamics is sluggish or glass-like. Surprisingly, {\eta}
+is a constant above {\phi}S. To determine the mechanism of this unusual
+dependence of {\eta} on {\phi}, we performed extensive simulations using an
+agent-based model of a dense non-confluent two-dimensional tissue. We show that
+polydispersity in the cell size, and the propensity of the cells to deform,
+results in the saturation of the available free area per cell beyond a critical
+packing fraction. Saturation in the free space not only explains the viscosity
+plateau above {\phi}S but also provides a relationship between equilibrium
+geometrical packing to the dramatic increase in the relaxation dynamics.",2211.14242v2
+2022-11-30,Computationally Efficient Reinforcement Learning: Targeted Exploration leveraging Simple Rules,"Model-free Reinforcement Learning (RL) generally suffers from poor sample
+complexity, mostly due to the need to exhaustively explore the state-action
+space to find well-performing policies. On the other hand, we postulate that
+expert knowledge of the system often allows us to design simple rules we expect
+good policies to follow at all times. In this work, we hence propose a simple
+yet effective modification of continuous actor-critic frameworks to incorporate
+such rules and avoid regions of the state-action space that are known to be
+suboptimal, thereby significantly accelerating the convergence of RL agents.
+Concretely, we saturate the actions chosen by the agent if they do not comply
+with our intuition and, critically, modify the gradient update step of the
+policy to ensure the learning process is not affected by the saturation step.
+On a room temperature control case study, it allows agents to converge to
+well-performing policies up to 6-7x faster than classical agents without
+computational overhead and while retaining good final performance.",2211.16691v3
+2022-10-15,Convolutional Long Short-Term Memory (convLSTM) for Spatio-Temporal Forecastings of Saturations and Pressure in the SACROC Field,"A machine learning architecture composed of convolutional long short-term
+memory (convLSTM) is developed to predict spatio-temporal parameters in the
+SACROC oil field, Texas, USA. The spatial parameters are recorded at the end of
+each month for 30 years (360 months), approximately 83% (300 months) of which
+is used for training and the rest 17% (60 months) is kept for testing. The
+samples for the convLSTM models are prepared by choosing ten consecutive frames
+as input and ten consecutive frames shifted forward by one frame as output.
+Individual models are trained for oil, gas, and water saturations, and pressure
+using the Nesterov accelerated adaptive moment estimation (Nadam) optimization
+algorithm. A workflow is provided to comprehend the entire process of data
+extraction, preprocessing, sample preparation, training, testing of machine
+learning models, and error analysis. Overall, the convLSTM for spatio-temporal
+prediction shows promising results in predicting spatio-temporal parameters in
+porous media.",2212.00796v1
+2022-12-04,Global stabilizability to trajectories for the Schlögl equation in a Sobolev norm,"The stabilizability to trajectories of the Schl\""ogl model is investigated in
+the norm of the natural state space for strong solutions, which is strictly
+contained in the standard pivot space of square integrable functions. As
+actuators a finite number of indicator functions are used and the control input
+is subject to a bound constraint. A stabilizing saturated explicit feedback
+control is proposed, where the set of actuators and the input bound are
+independent of the targeted trajectory. Further, the existence of open-loop
+optimal stabilizing constrained controls and related first-order optimality
+conditions are investigated. These conditions are then used to compute
+stabilizing receding horizon based controls. Results of numerical simulations
+are presented comparing their stabilizing performance with that of saturated
+explicit feedback controls.",2212.01888v1
+2022-12-14,Parameterizations of Immiscible Two-Phase Flow in Porous Media,"A fundamental variable characterizing immiscible two-phase flow in porous
+media is the wetting saturation, which is the ratio between the pore volume
+filled with wetting fluid and the total pore volume. More generally, this
+variable comes from a specific choice of coordinates on some underlying space,
+the domain of variables that can be used to express the volumetric flow rate.
+The underlying mathematical structure allows for the introduction of other
+variables containing the same information, but which are more convenient from a
+theoretical point of view. We introduce along these lines polar coordinates on
+this underlying space, where the angle plays a role similar to the wetting
+saturation. We derive relations between these new variables based on the Euler
+homogeneity theorem. We formulate these relations in a coordinate-free fashion
+using differential forms. Lastly, we discuss and interpret the co-moving
+velocity in terms of this coordinate-free representation.",2212.07285v1
+2022-12-16,Indiscernibles and satisfaction classes in arithmetic,"We investigate the theory PAI (Peano Arithmetic with Indiscernibles). Models
+of PAI are of the form (M, I), where M is a model of PA, I is an unbounded set
+of order indiscernibles over M, and (M, I) satisfies the extended induction
+scheme for formulae mentioning I. Our main results are Theorems A and B below.
+  Theorem A. Let M be a nonstandard model of PA of any cardinality. M has an
+expansion to a model of PAI iff M has an inductive partial satisfaction class.
+  Theorem A yields the following corollary, which provides a new
+characterization of countable recursively saturated models of PA:
+  Corollary. A countable model M of PA is recursively saturated iff M has an
+expansion to a model of PAI.
+  Theorem B. There is a sentence s in the language obtained by adding a unary
+predicate I(x) to the language of arithmetic such that given any nonstandard
+model M of PA of any cardinality, M has an expansion to a model of PAI + s iff
+M has a inductive full satisfaction class.",2212.08411v1
+2022-12-18,Scaling of out-of-time ordered correlators in a non-Hermitian kicked rotor model,"We investigate the dynamics of the out-of-time-ordered correlators (OTOCs)
+via a non-Hermitian extension of the quantum kicked rotor model, where the
+kicking potential satisfies $\mathcal{PT}$-symmetry. The spontaneous
+$\cal{PT}$-symmetry breaking emerges when the strength of the imaginary part of
+the kicking potential exceeds a threshold value. We find, both analytically and
+numerically, that in the broken phase of $\cal{PT}$ symmetry, the OTOCs rapidly
+saturate with time evolution. Interestingly, the late-time saturation value
+scales as a pow-law in the system size. The mechanism of such scaling law
+results from the interplay between the effects of nonlocal operator in OTOCs
+and the time reversal induced by non-Hermitian driven potential.",2212.09194v1
+2022-12-23,Control of Positive Systems with an Unknown State-Dependent Power Law Input Delay and Input Saturation,"This paper is motivated by a class of positive systems with an input that is
+subject to an unknown state-dependent power law delay as well as saturation.
+For example, biological networks have non-negative protein concentration
+states. Mass action kinetics in these systems result in power law behavior,
+while complex interactions cause signal propagation delays. Incomplete network
+characterization makes delay state-dependence unknown. Manipulating network
+activity via modulated protein concentrations to attain desired performance is
+restricted by upper-bounds on concentration actuator authority. Here, an
+innovative control law exploits system dynamics to compensate for control
+domain restrictions. A Lyapunov stability analysis establishes that the
+reference tracking error of the closed-loop system is uniformly ultimately
+bounded. Numerical simulations on a human coagulation model show controller
+efficacy and better performance compared to the relevant literature. This
+example application steps toward personalized, closed-loop treatments for
+trauma coagulopathy, which currently has 30% mortality with open-loop clinical
+approaches.",2212.12095v1
+2023-01-03,The dipole cross section by the unintegrated gluon distribution at small $x$,"We apply a previously developed scheme to consistently include the improved
+saturation model for the unintegrated gluon distribution (UGD) in order to
+evaluate, in the framework of $k_{t}$ factorization, at small $x$ at the
+next-to-leading order (NLO) in $\alpha_{s}$. We start the unintegrated gluon
+distribution with a parametrization of the deep inelastic structure function
+for electromagnetic scattering with protons, and then extract the color dipole
+cross section, which preserves its behavior success in a wide range of
+$k_{t}^{2}$ in comparisons with the UGD models (M. Hentschinski, A. Sabio Vera
+and C. Salas (HSS), I.P.Ivanov and N.N.Nikolaev (IN) and G. Watt, A.D. Martin
+and M.G. Ryskin (WMR)) . These results show that the geometric scaling holds
+for the improved saturation model in a wide kinematic region $rQ_{s}$, and are
+comparable with the Golec-Biernat-W$\ddot{\mathrm{u}}$sthoff (GBW) model. The
+unintegrated gluon distribution at low and high momentum transfer in a wide
+range of $x$ is considered.",2301.01083v4
+2023-01-04,Nucleon Energy Correlators for the Color Glass Condensate,"We demonstrate the recently proposed nucleon energy-energy correlator
+(nucleon EEC) $f_{\rm EEC}(x,\theta)$ can unveil the gluon saturation in the
+small-$x$ regime in $eA$ collisions. The novelty of this probe is that it is
+fully inclusive just like the deep-inelastic scattering (DIS), with no
+requirements of jets or hadrons, but still provides an evident portal to the
+small-$x$ dynamics through the shape of the $\theta$-distribution. We find that
+the saturation prediction is significantly different from the expectation of
+the collinear factorization.",2301.01788v2
+2023-01-04,A GOA-Based Fault-Tolerant Trajectory Tracking Control for an Underwater Vehicle of Multi-Thruster System without Actuator Saturation,"This paper proposes an intelligent fault-tolerant control (FTC) strategy to
+tackle the trajectory tracking problem of an underwater vehicle (UV) under
+thruster damage (power loss) cases and meanwhile resolve the actuator
+saturation brought by the vehicle's physical constraints. In the proposed
+control strategy, the trajectory tracking component is formed by a refined
+backstepping algorithm that controls the velocity variation and a sliding mode
+control deducts the torque/force outputs; the fault-tolerant component is
+established based on a Grasshopper Optimization Algorithm (GOA), which provides
+fast convergence speed as well as satisfactory accuracy of deducting optimized
+reallocation of the thruster forces to compensate for the power loss in
+different fault cases. Simulations with or without environmental perturbations
+under different fault cases and comparisons to other traditional FTCs are
+presented, thus verifying the effectiveness and robustness of the proposed
+GOA-based fault-tolerant trajectory tracking design.",2301.01827v1
+2023-01-08,Saturation Numbers for Berge Cliques,"Let $F$ be a graph and $\mathcal{H}$ be a hypergraph, both embedded on the
+same vertex set. We say $\mathcal{H}$ is a Berge-$F$ if there exists a
+bijection $\phi:E(F)\to E(\mathcal{H})$ such that $e\subseteq \phi(e)$ for all
+$e\in E(F)$. We say $\mathcal{H}$ is Berge-$F$-saturated if $\mathcal{H}$ does
+not contain any Berge-$F$, but adding any missing edge to $\mathcal{H}$ creates
+a copy of a Berge-$F$.
+  The saturation number $\mathrm{sat}_k(n,\text{Berge-}F)$ is the least number
+of edges in a Berge-$F$-saturated $k$-uniform hypergraph on $n$ vertices.
+  We show
+  \[
+  \mathrm{sat}_k(n,\text{Berge-}K_\ell)\sim \frac{\ell-2}{k-1}n,
+  \]
+  for all $k,\ell\geq 3$. Furthermore, we provide some sufficient conditions to
+imply that $\mathrm{sat}_k(n,\text{Berge-}F)=O(n)$ for general graphs $F$.",2301.02973v2
+2023-01-30,Exploring Inelasticity in the S-Matrix Bootstrap,"The modern S-Matrix Bootstrap provides non-perturbative bounds on low-energy
+aspects of scattering amplitudes, leveraging the constraints of unitarity,
+analyticity and crossing. Typically, the solutions saturating such bounds also
+saturate the unitarity constraint as much as possible, meaning that they are
+almost exclusively elastic. This is expected to be unphysical in $d>2$ because
+of Aks' theorem. We explore this issue by adding inelasticity as an additional
+input, both using a primal approach in general dimensions which extends the
+usual ansatz, and establishing a dual formulation in the 2d case. We then
+measure the effects on the low-energy observables where we observe stronger
+bounds than in the standard setup.",2301.13219v3
+2023-02-02,Studies of the equation-of-state of nuclear matter by heavy-ion collisions at intermediate energy in the multi-messenger era,"The study of the equation-of-state (EoS) describing the properties of nuclear
+matter away from the normal conditions is a relevant and intriguing topic of
+modern nuclear physics. The last decades have witnessed a substantial
+experimental progress in derivation of the symmetric matter term of the EoS and
+of the so-called symmetry energy for the asymmetric matter, especially at
+densities below the saturation point. But it is only in recent years that the
+opening of the multi-messenger astronomy era, triggered by detection of
+gravitational waves due to the neutron star mergers, has renewed and enlarged
+the interest in high-density EoS, being the main ingredient for determining the
+structure and properties of neutron stars. In this paper we review our
+knowledge obtained from heavy-ion collisions up to the 1 GeV/nucleon regime, on
+the EoS above nuclear saturation density. Special emphasis is given on the
+still few results on symmetry energy at high densities and their
+interconnections with multi-messenger astronomy findings.",2302.01453v1
+2023-02-18,Distributed Optimization for Reactive Power Sharing and Stability of Inverter-Based Resources Under Voltage Limits,"Reactive power sharing and containment of voltages within limits for
+inverter-based resources (IBRs) are two important, yet coupled objectives in ac
+networks. In this article, we propose a distributed control technique to
+simultaneously achieve these objectives. Our controller consists of two
+components: a purely local nonlinear integral controller which adjusts the IBR
+voltage setpoint, and a distributed primal-dual optimizer that coordinates
+reactive power sharing between the IBRs. The controller prioritizes the voltage
+containment objective over reactive power sharing at all points in time;
+excluding the IBRs with saturated voltages, it provides reactive power sharing
+among all the IBRs. Considering the voltage saturation and the coupling between
+voltage and angle dynamics, a formal closed-loop stability analysis based on
+singular perturbation theory is provided, yielding practical tuning guidance
+for the overall control system. To validate the effectiveness of the proposed
+controller for different case studies, we apply it to a low-voltage microgrid
+and a microgrid adapted from the CIGRE medium-voltage network benchmark, both
+simulated in the MATLAB/Simulink environment.",2302.09241v2
+2023-02-19,A robust multiplicity result in a generalized diffusive predator-prey model,"This paper analyzes the generalized spatially heterogeneous diffusive
+predator-prey model introduced by the authors in \cite{LGMH20}, whose
+interaction terms depend on a saturation coefficient $m(x)\gneq0$. As the
+amplitude of the saturation term, measured by $\|m\|_\infty$, blows up to
+infinity, the existence of, at least, two coexistence states, is established in
+the region of the parameters where the semitrivial positive solution is
+linearly stable, regardless the sizes and the shapes of the remaining function
+coefficients in the setting of the model. In some further special cases, an
+$S$-shaped component of coexistence states can be constructed, which causes the
+existence of, at least, three coexistence states, though this multiplicity
+occurs within the parameter regions where the semitrivial positive solution is
+linearly unstable. Therefore, these multiplicity results inherit a rather
+different nature.",2302.09684v1
+2023-02-27,Distributed Fixed-Time Consensus Control for Multiple AUV Systems with Input Saturations,"This study proposes a new distributed control method based on an adaptive
+fuzzy control for multiple collaborative autonomous underwater vehicles (AUVs)
+to track a desired formation shape within a fixed time. First, a formation
+control protocol based on a fixed-time backstepping sliding mode control is
+designed, in which the consensus cooperative tracking errors for each AUV will
+be formulated. Then, to compensate for the saturated control torques, an
+adaptive auxiliary variable is introduced. Finally, a fixed-time adaptive fuzzy
+logic control (FLC) is derived to approximate the unknown dynamics, in which
+the adaptive laws of the FLC is derived such that the adaptive signals and
+errors can be convergent within a fixed time. The fixed time convergence is
+desired in practice because it provides an exciting property that the global
+convergence of the whole system is independent with the initial states of the
+AUVs. The computer simulation results for a consensus formation control of four
+AUVs show that the proposed formation control can provide high tracking
+performance with lower and smoother control efforts",2302.14162v1
+2023-02-28,Confined-state physics and signs of fermionization of moiré excitons in WSe$_2$/MoSe$_2$ heterobilayers,"We revisit and extend the standard bosonic interpretation of interlayer
+excitons in the moir\'e potential of twisted heterostructures of
+transition-metal dichalcogenides. In our experiments, we probe a high quality
+MoSe$_2$/WSe$_2$ van der Waals bilayer heterostructure via density-dependent
+photoluminescence spectroscopy and reveal strongly developed, unconventional
+spectral shifts of the emergent moir\'e exciton resonances. The observation of
+saturating blueshifts of successive exciton resonances allow us to explain
+their physics in terms of a model utilizing fermionic saturable absorbers. This
+approach is strongly inspired by established quantum-dot models, which
+underlines the close analogy of interlayer excitons trapped in pockets of the
+moir\'e potential, and quantum emitters with discrete eigenstates.",2302.14489v2
+2023-03-14,The improved saturation model in nuclei,"We consider the nuclear shadowing in deep-inelastic scattering corresponding
+to kinematic regions accessible by future experiments at electron-ion
+colliders. The gluon distribution at low $x$ is obtained using an improved
+dipole model on the impact parameter for nuclei. The nuclear shadowing at small
+$x$ is defined within the color dipole formalism with respect to the mass
+number $A$. Its behavior is predicted for light nuclei in a wide range of the
+impact parameter $b$ and the transverse dipole size $r$. The nuclear saturation
+at large-$r$ is observable. The behavior of the nuclear ratio
+$\sigma^{A}_{\mathrm{dip}}/\sigma_{0}$ is similar to the
+Golec-Biernat-W$\ddot{\mathrm{u}}$sthoff (GBW) model in a wide range of $r$ and
+$A$ at small $x$. The results are compared with nCETQ15 parametrization group.",2303.07654v3
+2023-03-15,A Momentum Two-gradient Direction Algorithm with Variable Step Size Applied to Solve Practical Output Constraint Issue for Active Noise Control,"Active noise control (ANC) has been widely utilized to reduce unwanted
+environmental noise. The primary objective of ANC is to generate an anti-noise
+with the same amplitude but the opposite phase of the primary noise using the
+secondary source. However, the effectiveness of the ANC application is impacted
+by the speaker's output saturation. This paper proposes a two-gradient
+direction ANC algorithm with a momentum factor to solve the saturation with
+faster convergence. In order to make it implemented in real-time, a
+computation-effective variable step size approach is applied to further reduce
+the steady-state error brought on by the changing gradient directions. The time
+constant and step size bound for the momentum two-gradient direction algorithm
+is analyzed. Simulation results show that the proposed algorithm performs
+effectively in the time-unvaried and time-varied environment.",2303.08397v1
+2023-03-26,Constraining nuclear symmetry energy with the charge radii of mirror-pair nuclei,"The nuclear charge radius plays a vital role in determining the equation of
+state of isospin asymmetric nuclear matter.
+  Based on the correlation between the differences in charge radii of
+mirror-partner nuclei and the slope parameter ($L$) of symmetry energy at the
+nuclear saturation density, an analysis of the calibrated slope parameter $L$
+was performed in finite nuclei. In this study, relativistic and
+non-relativistic energy density functionals were employed to constrain the
+nuclear symmetry energy through the available databases of the mirror-pair
+nuclei $^{36}$Ca-$^{36}$S, $^{38}$Ca-$^{38}$Ar, and $^{54}$Ni-$^{54}$Fe. The
+deduced nuclear symmetry energy was located in the range 29.89-31.85 MeV, and
+$L$ of the symmetry energy essentially covered the range 22.50-51.55 MeV at the
+saturation density. Moreover, the extracted $L_s$ at the sensitivity density
+$\rho_{s}=0.10~\mathrm{fm}^{-3}$ was located in the interval range 30.52-39.76
+MeV.",2303.14667v2
+2023-03-27,$α$ + core structure described with an additional interaction in the nuclear matter saturation region,"In a phenomenological approach, the $\alpha$ + core structure is investigated
+in the $^{20}$Ne, $^{44}$Ti, $^{94}$Mo, $^{104}$Te, and $^{212}$Po nuclei
+through the local potential model using a double-folding nuclear potential with
+effective nucleon-nucleon interaction of M3Y + $c_{\mathrm{sat}}\delta(s)$
+type, where the term $c_{\mathrm{sat}}\delta(s)$ acts only between the
+saturation regions of $\alpha$-cluster and core. Properties such as energy
+levels, $\alpha$-widths, $B(E2)$ transition rates, and half-lives are
+calculated, and good level of agreement with experimental data is obtained in
+general. It is shown the inclusion of the term $c_{\mathrm{sat}}\delta(s)$ is
+determinant for a better description of the experimental energy levels compared
+to the ground state bands produced with the simple M3Y interaction. The
+properties calculated for $^{104}$Te reinforce the superallowed $\alpha$-decay
+feature for this nucleus, as indicated in previous studies.",2303.14927v1
+2023-03-31,Lamb dip of a Quadrupole Transition in H$_2$,"The saturated absorption spectrum of the hyperfine-less S(0) quadrupole line
+in the (2-0) band of H$_2$ is measured at $\lambda=1189$ nm, using the
+NICE-OHMS technique under cryogenic conditions (72~K). It is for the first time
+that a Lamb dip of a molecular quadrupole transition is recorded. At low
+(150-200 W) saturation powers a single narrow Lamb dip is observed, ruling out
+an underlying recoil doublet of 140 kHz. Studies of Doppler-detuned resonances
+show that the red-shifted recoil component can be made visible for low
+pressures and powers, and prove that the narrow Lamb dip must be interpreted as
+the blue recoil component. A transition frequency of 252\,016\,361\,164\,(8)
+kHz is extracted, which is off by -2.6 (1.6) MHz from molecular quantum
+electrodynamical calculations therewith providing a challenge to theory.",2303.17818v1
+2023-04-03,Constraints on the in-medium nuclear interaction from chiral symmetry and Lattice-QCD,"In this paper we discuss the combined effects on nuclear matter properties of
+the quark confinement mechanism in nucleon and of the chiral effective
+potential resulting from the spontaneous breaking of the chiral symmetry in
+nuclear matter. Based on the Nambu-Jona-Lasinio predictions, it is shown that
+the chiral potential acquires a specific scalar field cubic dependence, which
+contributes to the three-body interaction. We also discuss the constraints
+induced by Lattice-QCD on the model parameters governing the saturation
+properties. We introduce the term ""QCD-connected parameters"" for these
+quantities. We demonstrate that chiral symmetry and Lattice-QCD provide
+coherent constraints on the in-medium nuclear interaction, suggesting a
+fundamental origin of the saturation mechanism.",2304.01036v1
+2023-04-10,Better Together: Unifying Datalog and Equality Saturation,"We present egglog, a fixpoint reasoning system that unifies Datalog and
+equality saturation (EqSat). Like Datalog, it supports efficient incremental
+execution, cooperating analyses, and lattice-based reasoning. Like EqSat, it
+supports term rewriting, efficient congruence closure, and extraction of
+optimized terms.
+  We identify two recent applications--a unification-based pointer analysis in
+Datalog and an EqSat-based floating-point term rewriter--that have been
+hampered by features missing from Datalog but found in EqSat or vice-versa. We
+evaluate egglog by reimplementing those projects in egglog. The resulting
+systems in egglog are faster, simpler, and fix bugs found in the original
+systems.",2304.04332v4
+2023-04-10,Criticality versus uniformity in deep neural networks,"Deep feedforward networks initialized along the edge of chaos exhibit
+exponentially superior training ability as quantified by maximum trainable
+depth. In this work, we explore the effect of saturation of the tanh activation
+function along the edge of chaos. In particular, we determine the line of
+uniformity in phase space along which the post-activation distribution has
+maximum entropy. This line intersects the edge of chaos, and indicates the
+regime beyond which saturation of the activation function begins to impede
+training efficiency. Our results suggest that initialization along the edge of
+chaos is a necessary but not sufficient condition for optimal trainability.",2304.04784v1
+2023-04-21,The Effect of Particle Size and Concentration on Low-Frequency Terahertz Scattering in Granular Compacts,"Fundamental knowledge of scattering in granular compacts is essential to
+ensure accuracy of spectroscopic measurements and determine material
+characteristics such as size and shape of scattering objects. Terahertz
+time-domain spectroscopy (THz-TDS) was employed to investigate the effect of
+particle size and concentration on scattering in specially fabricated compacts
+consisting of borosilicate microspheres in a polytetrafluoroethylene (PTFE)
+matrix. As expected, increasing particle size leads to an increase in overall
+scattering contribution. At low concentrations, the scattering contribution
+increases linearly with concentration. Scattering increases linearly at low
+concentrations, saturates at higher concentrations with a maximum level
+depending on particle size, and that the onset of saturation is independent of
+particle size. The effective refractive index becomes sublinear at high
+particle concentrations and exceeds the linear model at maximum density, which
+can cause errors in calculations based on it, such as porosity. The observed
+phenomena are attributed to the change in the fraction of photons propagating
+ballistically versus being scattered. At low concentrations, photons travel
+predominately ballistically through the PTFE matrix. At high concentrations,
+the photons again propagate ballistically through adjacent glass microspheres.
+In the intermediate regime, photons are predominately scattered.",2304.10974v1
+2023-04-24,TextMesh: Generation of Realistic 3D Meshes From Text Prompts,"The ability to generate highly realistic 2D images from mere text prompts has
+recently made huge progress in terms of speed and quality, thanks to the advent
+of image diffusion models. Naturally, the question arises if this can be also
+achieved in the generation of 3D content from such text prompts. To this end, a
+new line of methods recently emerged trying to harness diffusion models,
+trained on 2D images, for supervision of 3D model generation using view
+dependent prompts. While achieving impressive results, these methods, however,
+have two major drawbacks. First, rather than commonly used 3D meshes, they
+instead generate neural radiance fields (NeRFs), making them impractical for
+most real applications. Second, these approaches tend to produce over-saturated
+models, giving the output a cartoonish looking effect. Therefore, in this work
+we propose a novel method for generation of highly realistic-looking 3D meshes.
+To this end, we extend NeRF to employ an SDF backbone, leading to improved 3D
+mesh extraction. In addition, we propose a novel way to finetune the mesh
+texture, removing the effect of high saturation and improving the details of
+the output 3D mesh.",2304.12439v1
+2023-04-28,Molecular charmed baryons and pentaquarks from light-meson exchange saturation,"The spectrum of the $c qq$ baryons contains a few states whose nature is not
+clearly a three-quark composite and which might have a sizable baryon-meson
+component. Examples include the $\Sigma_c(2800)$ or the $\Lambda_c(2940)$. Here
+we explore the spectrum of two-body systems composed of a light, octet baryon
+and a charmed meson (or antimeson) within a simple contact-range theory in
+which the couplings are saturated by light-meson exchanges. This results in the
+prediction of a series of composite anticharmed pentaquarks ($\bar{c} q qqq $)
+and singly-charmed baryons ($c \bar{q} qqq $). Among the later we find
+$J=\tfrac{1}{2}$ $\Xi D$ and $J=\tfrac{3}{2}$ $\Xi D^*$ bound states with
+masses matching those of the recently observed $\Omega_c(3185)$ and
+$\Omega_c(3327)$ baryons.",2304.14855v1
+2023-05-02,F2: Designing a Key-Value Store for Large Skewed Workloads,"Today's key-value stores are either disk-optimized, focusing on large data
+and saturating device IOPS, or memory-optimized, focusing on high throughput
+with linear thread scaling assuming plenty of main memory. However, many
+practical workloads demand high performance for read and write working sets
+that are much larger than main memory, over a total data size that is even
+larger. They require judicious use of memory and disk, and today's systems do
+not handle such workloads well. We present F2, a new key-value store design
+based on compartmentalization -- it consists of five key components that work
+together in well-defined ways to achieve high throughput -- saturating disk and
+memory bandwidths -- while incurring low disk read and write amplification. A
+key design characteristic of F2 is that it separates the management of hot and
+cold data, across the read and write domains, and adapts the use of memory to
+optimize each case. Through a sequence of new latch-free system constructs, F2
+solves the key challenge of maintaining high throughput with linear thread
+scalability in such a compartmentalized design. Detailed experiments on
+benchmark data validate our design's superiority, in terms of throughput, over
+state-of-the-art key-value stores, when the available memory resources are
+scarce.",2305.01516v1
+2023-05-08,Tweaking Spectral Topology and Exceptional Points by Nonlinearity in Non-Hermitian Polariton Systems,"Exceptional points (EPs) with their intriguing spectral topology have
+attracted considerable attention in a broad range of physical systems, with
+potential sensing applications driving much of the present research in this
+field. Here we theoretically demonstrate the realization of EPs in a system
+with significant nonlinearity, a non-equilibrium exciton-polariton condensate.
+With the possibility to control loss and gain and nonlinearity by optical
+means, this system allows for a comprehensive analysis of the interplay of
+nonlinearities (Kerr-type and saturable gain) and non-Hermiticity. Not only do
+we find that EPs can be intentionally shifted in parameter space by the
+saturable gain, we also observe intriguing rotations and intersections of
+Riemann surfaces, and find nonlinearity-enhanced sensing capabilities. Our
+results are quite general in nature and illustrate the potential of tailoring
+spectral topology and related phenomena in non-Hermitian systems by
+nonlinearity.",2305.04855v1
+2023-05-12,Saturated Non-Monotonic Activation Functions,"Activation functions are essential to deep learning networks. Popular and
+versatile activation functions are mostly monotonic functions, some
+non-monotonic activation functions are being explored and show promising
+performance. But by introducing non-monotonicity, they also alter the positive
+input, which is proved to be unnecessary by the success of ReLU and its
+variants. In this paper, we double down on the non-monotonic activation
+functions' development and propose the Saturated Gaussian Error Linear Units by
+combining the characteristics of ReLU and non-monotonic activation functions.
+We present three new activation functions built with our proposed method:
+SGELU, SSiLU, and SMish, which are composed of the negative portion of GELU,
+SiLU, and Mish, respectively, and ReLU's positive portion. The results of image
+classification experiments on CIFAR-100 indicate that our proposed activation
+functions are highly effective and outperform state-of-the-art baselines across
+multiple deep learning architectures.",2305.07537v2
+2023-05-17,Evolution of Coupled Weakly-Driven Waves in a Dissipative Plasma,"The nonlinear collisional dynamics of coupled driven plasma waves in the
+presence of background dissipation is studied analytically within kinetic
+theory. Sufficiently near marginal stability, phase space correlations are
+poorly preserved and time delays become unimportant. The system is then shown
+to be governed by two first-order coupled autonomous differential equations of
+cubic order for the wave amplitudes and two complementary first-order equations
+for the evolution of their phases. That system of equations can be decoupled
+and further simplified to a single second-order differential equation of
+Li\'enard's type for each amplitude. Numerical solutions for this equation are
+obtained in the general case while analytic solutions are obtained for special
+cases in terms of parameters related to the spacing of the resonances of the
+two waves in frequency space, e.g., wave lengths and oscillation frequencies.
+These parameters are further analyzed to find classes of quasi-steady
+saturation and pulsating scenarios. To classify equilibrium points, local
+stability analysis is applied, and bifurcation conditions are determined. When
+the two waves saturate at similar amplitude levels, their combined signal is
+shown to invariably exhibit amplitude beating and phase jumps of nearly $\pi$.
+The obtained analytical results can be used to benchmark simulations and to
+interpret eigenmode amplitude measurements in fusion experiments.",2305.10322v1
+2023-05-23,The covariety of saturated numerical semigroups with fixed Frobenius number,"In this work we will show that if $F$ is a positive integer, then
+${\mathrm{Sat}}(F)=\{S\mid S \mbox{ is a saturated numerical semigroup with
+Frobenius number } F\}$ is a covariety. As a consequence, we present two
+algorithms: one that computes ${\mathrm{Sat}}(F),$ and the other which computes
+all the elements of ${\mathrm{Sat}}(F)$ with a fixed genus.
+  If $X\subseteq S\backslash \Delta(F)$ for some $S\in {\mathrm{Sat}}(F),$ then
+we will see that there is the least element of ${\mathrm{Sat}}(F)$ containing a
+$X$. This element will denote by ${\mathrm{Sat}}(F)[X].$
+  If $S\in{\mathrm{Sat}}(F),$ then we define the ${\mathrm{Sat}}(F)$-rank of
+$S$ as the minimum of $\{\mbox{cardinality}(X)\mid S={\mathrm{Sat}}(F)[X]\}.$
+In this paper, also we present an algorithm to compute all the element of
+${\mathrm{Sat}}(F)$ with a given
+  ${\mathrm{Sat}}(F)$-rank.",2305.13881v1
+2023-05-24,A discrete-time Pontryagin maximum principle under rate constraints,"Limited bandwidth and limited saturation in actuators are practical concerns
+in control systems. Mathematically, these limitations manifest as constraints
+being imposed on the control actions, their rates of change, and more
+generally, the global behavior of their paths. While the problem of actuator
+saturation has been studied extensively, little attention has been devoted to
+the problem of actuators having limited bandwidth. While attempts have been
+made in the direction of incorporating frequency constraints on state-action
+trajectories before, rate constraints on the control at the design stage have
+not been studied extensively in the discrete-time regime. This article
+contributes toward filling this lacuna. In particular, we establish a new
+discrete-time Pontryagin maximum principle with rate constraints being imposed
+on the control trajectories, and derive first-order necessary conditions for
+optimality. A brief discussion on the existence of optimal control is included,
+and numerical examples are provided to illustrate the results.",2305.14940v1
+2023-05-24,Breaking the Curse of Quality Saturation with User-Centric Ranking,"A key puzzle in search, ads, and recommendation is that the ranking model can
+only utilize a small portion of the vastly available user interaction data. As
+a result, increasing data volume, model size, or computation FLOPs will quickly
+suffer from diminishing returns. We examined this problem and found that one of
+the root causes may lie in the so-called ``item-centric'' formulation, which
+has an unbounded vocabulary and thus uncontrolled model complexity. To mitigate
+quality saturation, we introduce an alternative formulation named
+``user-centric ranking'', which is based on a transposed view of the dyadic
+user-item interaction data. We show that this formulation has a promising
+scaling property, enabling us to train better-converged models on substantially
+larger data sets.",2305.15333v1
+2023-05-31,Composite Triggered Intermittent Control for Constrained Spacecraft Attitude Tracking,"This paper focuses on the spacecraft attitude control problem with
+intermittent actuator activation, taking into account the attitude rotation
+rate limitation and input saturation issue simultaneously. To address this
+problem, we first propose a composite event-trigger mechanism, which composed
+of two state-dependent trigger that governing the activation and deactivation
+of actuators. Subsequently, by introducing the cascaded decomposition of
+Backstepping control philosophy, the designed trigger mechanism is then applied
+to the decomposed dynamical subsystem, providing a layered intermittent
+stabilization strategy.
+  Further, the basic intermittent attitude controller is extended to a
+""constrained version"" by introducing a strictly bounded virtual control law and
+an input saturation compensation auxiliary system.
+  By analyzing the local boundedness of the system on each inter-event time
+interval, a uniformly, strictly decreasing upper boundary of the lumped system
+is further characterized, thereby completing the proof of the system's
+uniformly ultimately boundedness (UUB). Finally, numerical simulation results
+are illustrated to demonstrate the effectiveness of the proposed scheme.",2305.19644v1
+2023-06-07,Surface Saturation Current Densities of Perovskite Thin Films from Suns-Photoluminescence Quantum Yield Measurements,"We present a simple, yet powerful analysis of Suns-photoluminescence quantum
+yield measurements that can be used to determine the surface saturation current
+densities of thin film semiconductors. We apply the method to state-of-the-art
+polycrystalline perovskite thin films of varying absorber thickness. We show
+that the non-radiative bimolecular recombination in these samples originates
+from the surfaces. To the best of our knowledge, this is the first study to
+demonstrate and quantify non-linear (bimolecular) surface recombination in
+perovskite thin films.",2306.04194v1
+2023-06-07,Forward $γ$+jet production in proton-proton and proton-lead collisions at LHC within the FoCal calorimeter acceptance,"Using the small-$x$ Improved Transverse Momentum Dependent factorization
+(ITMD), which, for a general two-to-two massless scattering can be proved
+within the Color Glass Condensate (CGC) theory for transverse momenta of
+particles greater than the saturation scale, we provide predictions for
+isolated forward photon and jet production in proton-proton and proton-nucleus
+collisions within the planned ALICE FoCal detector acceptance. We study
+azimuthal correlations, $p_T$ spectra, as well as normalized ratios of
+proton-proton cross sections for different energies. The only TMD distribution
+needed for that process is the ""dipole"" TMD gluon distribution, which in our
+computations is based on HERA data and undergoes momentum space BK evolution
+equation with DGLAP corrections and Sudakov resummation. We conclude, that the
+process provides an excellent probe of the dipole TMD gluon distribution in
+saturation regime.",2306.04706v2
+2023-06-19,Frame potential of Brownian SYK model of Majorana and Dirac fermions,"We consider the Brownian SYK, i.e. a system of $N$ Majorana (Dirac) fermions
+with a white-noise $q$-body interaction term. We focus on the dynamics of the
+Frame potentials, a measure of the scrambling and chaos, given by the moments
+of the overlap between two independent realisations of the model. By means of a
+Keldysh path-integral formalism, we compute its early and late-time value. We
+show that, for $q>2$, the late time path integral saddle point correctly
+reproduces the saturation to the value of the Haar frame potential. On the
+contrary, for $q=2$, the model is quadratic and consistently we observe
+saturation to the Haar value in the restricted space of Gaussian states
+(Gaussian Haar). The latter is characterised by larger system size corrections
+that we correctly capture by counting the Goldstone modes of the Keldysh saddle
+point. Finally, in the case of Dirac fermions, we highlight and resolve the
+role of the global $U(1)$ symmetry.",2306.11160v3
+2023-06-21,Multiplicity distribution and entropy of produced gluons in deep inelastic scattering at high energies,"In this paper we found the multiplicity distribution of the produced gluons
+in deep inelastic scattering at large $z=\ln\LbQ^2_s/Q^2\Rb\,\,\gg\,\,1$ where
+$ Q_s $ is the saturation momentum and $Q^2$ is the photon virtuality. It turns
+out that this distribution at large $n > \bar{n}$ almost reproduces the KNO
+scaling behaviour with the average number of gluons $ \bar{n} \propto \exp\Lb
+z^2/2 \kappa\Rb$, where $\kappa = 4.88 $ in the leading order of perturbative
+QCD. TheKNO function $\Psi\Lb \frac{n}{\bar{n}}\Rb = \exp\Lb -\,n/\bar{n}\Rb$.
+For $n < \bar{n}$ we found that $\sigma_n \propto\Big( z - \sqrt{2
+\,\kappa\,\ln (n-1)}\Big)/(n-1)$. Such small $n$ determine the value of entropy
+of produced gluons $S_E = 0.3\, z^2/(2\,\kappa)$ at large $z$. The factor $0.3$
+stems from the non-perturbative corrections that provide the correct behaviour
+of the saturation momentum at large $b$.",2306.12055v1
+2023-06-21,Softening the UV without New Particles,"We explore an odd class of QFTs where a hierarchy problem is resolved with
+new dynamics as opposed to new particles. The essential element of our
+construction is a $U(1)$ pseudo-NG boson with symmetry breaking interactions
+all characterized by a large number $N$ of units of the fundamental charge. In
+the resulting effective theory, quantum corrections, like those to the
+effective potential and mass, which are normally power divergent and saturated
+at the UV cut-off, are instead saturated at a much lower scale. This critical
+scale, which does not involve any new particle, corresponds to the onset of
+unsuppressed multiparticle production in scattering processes. Remarkably this
+all happens within the tractable domain of weak coupling. Terms involving
+arbitrarily high powers of the Goldstone field must however be taken into
+account. In particular, a truncation to the renormalizable part of the
+effective Lagrangian would completely miss the physics.",2306.12489v2
+2023-06-26,Hot hole transport and noise phenomena in silicon at cryogenic temperatures from first principles,"The transport properties of hot holes in silicon at cryogenic temperatures
+exhibit several anomalous features, including the emergence of two distinct
+saturated drift velocity regimes and a non-monotonic trend of the current noise
+versus electric field at microwave frequencies. Despite prior investigations,
+these features lack generally accepted explanations. Here, we examine the
+microscopic origin of these phenomena by extending a recently developed
+ab-initio theory of high-field transport and noise in semiconductors. We find
+that the drift velocity anomaly may be attributed to scattering dominated by
+acoustic phonon emission, leading to an additional regime of drift velocity
+saturation at temperatures $\sim 40$ K for which the acoustic phonon occupation
+is negligible; while the non-monotonic trend in the current noise arises due to
+the decrease in momentum relaxation time with electric field. The former
+conclusion is consistent with the findings of prior work, but the latter
+distinctly differs from previous explanations. This work highlights the use of
+high-field transport and noise phenomena as sensitive probes of microscopic
+charge transport phenomena in semiconductors.",2306.14986v1
+2023-06-30,Analytical prediction of the temperature and the lifetime of an evaporating spherical droplet,"In this paper, we propose to predict analytically the temperature of an
+evaporating spherical droplet. To do so, we first review, from data in the
+literature, the effect of temperature on the physical parameters involved in
+cooling-induced evaporation, namely the saturating vapor pressure, the
+diffusion coefficient of vapor in air, the liquid density, the enthalpy of
+vaporization and the thermal conductivity of air. These data support a series
+of approximations that allows us to derive an implicit equation for the liquid
+temperature. We propose a quadratic approximation of the variation of the
+saturating vapor concentration with temperature to obtain an explicit
+prediction of the drop temperature. As a result, an analytical prediction of
+the droplet lifetime including the cooling effect is proposed.",2306.17534v1
+2023-07-10,Graph Convolutional Networks for Simulating Multi-phase Flow and Transport in Porous Media,"Numerical simulation of multi-phase fluid dynamics in porous media is
+critical for many subsurface applications. Data-driven surrogate modeling
+provides computationally inexpensive alternatives to high-fidelity numerical
+simulators. While the commonly used convolutional neural networks (CNNs) are
+powerful in approximating partial differential equation solutions, it remains
+challenging for CNNs to handle irregular and unstructured simulation meshes.
+However, subsurface simulation models often involve unstructured meshes with
+complex mesh geometries, which limits the application of CNNs. To address this
+challenge, here we construct surrogate models based on Graph Convolutional
+Networks (GCNs) to approximate the spatial-temporal solutions of multi-phase
+flow and transport processes. We propose a new GCN architecture suited to the
+hyperbolic character of the coupled PDE system, to better capture the
+saturation dynamics. Results of 2D heterogeneous test cases show that our
+surrogates predict the evolutions of the pressure and saturation states with
+high accuracy, and the predicted rollouts remain stable for multiple timesteps.
+Moreover, the GCN-based models generalize well to irregular domain geometries
+and unstructured meshes that are unseen in the training dataset.",2307.04449v1
+2023-07-11,Signatures of Ultralight Bosons in Compact Binary Inspiral and Outspiral,"Ultralight bosons are well-motivated particles from various physical and
+cosmological theories, and can be spontaneously produced during the
+superradiant process, forming a dense hydrogen-like cloud around the spinning
+black hole. After the growth saturates, the cloud slowly depletes its mass
+through gravitational-wave emission. In this work we study the orbit dynamics
+of a binary system containing such a gravitational atom saturated in various
+spin-0,1,2 superradiant states, taking into account both the effects of
+dynamical friction and the cloud mass depletion. We estimate the significance
+of mass depletion, finding that although dynamical friction could dominate the
+inspiral phase, it typically does not affect the outspiral phase driven by the
+mass depletion. Focusing on the large orbit radius, we investigate the
+condition to observe the outspiral, and the detectability of the cloud via
+pulsar-timing signal in the case of black hole-pulsar binary.",2307.05181v2
+2023-02-02,Reducing cartel recruitment is the only way to lower violence in Mexico,"Every year, Mexican cartels lose many members due to conflict with other
+cartels and arrests. Yet, despite their losses, cartels have managed to
+increase violence for years. We address this puzzle by leveraging data on the
+number of homicides, missing persons and arrests in Mexico for the past ten
+years, along with information on the interactions among cartels aiming to
+estimate the size of cartels' population. We model recruitment, incapacitation
+by the state, conflict and saturation as the reasons why cartels vary in size.
+Results show that by 2022 cartels have between 160,000 and 185,000 units,
+becoming one of the top employers in the country. Recruiting at least 350
+people per week is essential to avoid their collapse due to the aggregate
+effect of incapacitation, conflict and saturation. Furthermore, we test the
+effects of two policy scenarios aimed at decreasing cartel violence. We show
+that given the state of violence, increasing current levels of incapacitation
+leads to a rise in homicides and cartel members. Conversely, reducing
+recruitment provides substantial benefits in terms of violence reduction and
+decreasing cartel population, calling for structural investments in a proactive
+strategy that targets individuals at risk rather than a traditional reactive
+approach centred around incapacitation.",2307.06302v1
+2023-07-16,Seis2Rock: A Data-Driven Approach to Direct Petrophysical Inversion of Pre-Stack Seismic Data,"The inversion of petrophysical parameters from seismic data represents a
+fundamental step in the process of characterizing the subsurface. We propose a
+novel, data-driven approach named Seis2Rock that utilizes optimal basis
+functions learned from well log information to directly link band-limited
+petrophysical reflectivities to pre-stack seismic data. Seis2Rock is composed
+of two stages: training and inference. During training, a set of optimal basis
+functions are identified by performing singular value decomposition on one or
+more synthetic AVO gathers created from measured or rock-physics synthesized
+elastic well-logs. In inference, seismic pre-stack data are first projected
+into a set of band-limited petrophysical properties using the previously
+computed basis functions; this is followed by regularized post-stack seismic
+inversion of the individual properties. In this work, we apply the Seis2Rock
+methodology to a synthetic dataset based on the Smeaheia reservoir model and
+the open Volve field dataset. Numerical results reveal the ability of the
+proposed method in recovering accurate porosity, shale content, and water
+saturation models. Finally, the proposed methodology is applied in the context
+of reservoir monitoring to invert time-lapse, pre-stack seismic data for water
+saturation changes.",2307.07969v2
+2023-07-20,Practical Active Noise Control: Restriction of Maximum Output Power,"This paper presents some recent algorithms developed by the authors for
+real-time adaptive active noise (AANC) control systems. These algorithms
+address some of the common challenges faced by AANC systems, such as speaker
+saturation, system divergence, and disturbance rejection. Speaker saturation
+can introduce nonlinearity into the adaptive system and degrade the noise
+reduction performance. System divergence can occur when the secondary speaker
+units are over-amplified or when there is a disturbance other than the noise to
+be controlled. Disturbance rejection is important to prevent the adaptive
+system from adapting to unwanted signals. The paper provides guidelines for
+implementing and operating real-time AANC systems based on these algorithms.",2307.10913v1
+2023-08-01,Black Holes as Neutrino Factories,"Ultralight bosons near rotating black holes can grow significantly via
+superradiant energy extraction, potentially reaching field values close to the
+Planck scale, thereby turning black holes into effective transducers for these
+fields. The interaction between a boson field and fermions can initiate a
+parametric production of fermions, potentially halting the exponential growth
+and leading to a saturated state of the boson cloud. This dynamic offers a
+framework for establishing limits on boson-neutrino interactions, which have
+traditionally been restricted by neutrino self-interaction considerations. At
+the saturation phase, boson clouds have the capacity to propel neutrinos to
+TeV-scale energies, generating fluxes that surpass atmospheric neutrino fluxes
+from nearby black holes. This mechanism extends to dark sector fermions,
+leading to the generation of boosted dark matter. These fluxes open novel
+avenues for observation through high-energy neutrino detectors like IceCube, as
+well as through dark matter direct detection, by directing observational
+efforts towards targeted black holes.",2308.00741v2
+2023-08-08,Exceptional Point Degeneracy as Desirable Operation Point of Oscillator Array with Discrete Nonlinear Gain and Radiating Elements,"An oscillator array prefers to operate at an exceptional point of degeneracy
+(EPD) occurring in a waveguide periodically loaded with discrete nonlinear gain
+and radiating elements. The system maintains a steady-state degenerate mode of
+oscillation at a frequency of 3 GHz, even when the small-signal nonlinear gain
+values are nonuniform along the array. Contrarily to the original expectation
+of zero phase shift associated to the designed EPD using small-signal gain,
+after reaching saturation, the time domain signal in consecutive unit cells
+displays a $\pi$ phase shift. Hence, we demonstrate that the saturated system
+oscillates at a distinct EPD, associated to a $\pi$ phase shift between
+consecutive cells, than the one at which the system was originally designed
+using small-signal gain. This new EPD at which the nonlinear system is landing
+is associated to higher power efficiency. Finally, we demonstrate that the
+oscillation frequency is independent of the length of the array, contrarily to
+what happens ordinary oscillating systems based on one-dimensional cavity
+resonances. These findings may have a high impact on high-power radiating
+arrays with distributed active elements.",2308.04562v1
+2023-08-17,Improving Modular Bootstrap Bounds with Integrality,"We implement methods that efficiently impose integrality -- i.e., the
+condition that the coefficients of characters in the partition function must be
+integers -- into numerical modular bootstrap. We demonstrate the method with a
+number of examples where it can be used to strengthen modular bootstrap
+results. First, we show that, with a mild extra assumption, imposing
+integrality improves the bound on the maximal allowed gap in dimensions of
+operators in theories with a $U(1)^c$ symmetry at $c=3$, and reduces it to the
+value saturated by the $SU(4)_1$ WZW model point of $c=3$ Narain lattices
+moduli space. Second, we show that our method can be used to eliminate all but
+a discrete set of points saturating the bound from previous Virasoro modular
+bootstrap results. Finally, when central charge is close to $1$, we can
+slightly improve the upper bound on the scaling dimension gap.",2308.08725v1
+2023-08-24,Quantized distributed Nash equilibrium seeking under DoS attacks: A quantized consensus based approach,"This paper studies distributed Nash equilibrium (NE) seeking under
+Denial-of-Service (DoS) attacks and quantization. The players can only exchange
+information with their own direct neighbors. The transmitted information is
+subject to quantization and packet losses induced by malicious DoS attacks. We
+propose a quantized distributed NE seeking strategy based on the approach of
+dynamic quantized consensus. To solve the quantizer saturation problem caused
+by DoS attacks, the quantization mechanism is equipped to have zooming-in and
+holding capabilities, in which the holding capability is consistent with the
+results in quantized consensus under DoS. A sufficient condition on the number
+of quantizer levels is provided, under which the quantizers are free from
+saturation under DoS attacks. The proposed distributed quantized NE seeking
+strategy is shown to have the so-called maximum resilience to DoS attacks.
+Namely, if the bound characterizing the maximum resilience is violated, an
+attacker can deny all the transmissions and hence distributed NE seeking is
+impossible.",2308.12617v1
+2023-08-31,The nuclear liquid-gas transition in QCD,"We estimate the nuclear saturation density and the binding energy in a
+nuclear liquid from precision data on the coupling of the four-quark scattering
+vertex in the vector channel, computed within functional QCD. We show that this
+coupling is directly related to the density-density potential and the latter is
+used for the estimates. In a first qualitative computation we find a saturation
+density of 0.2 fm${}^{-3}$ and an upper bound for the binding energy of 21.5
+MeV, in agreement with the empirical values of 0.16 fm${}^{-3}$ and 16 MeV,
+respectively. We also use the scattering vertex for constructing an emergent
+low-energy effective theory for the liquid gas transition from QCD correlation
+function, whose coupling parameters can be determined within QCD. As a first
+consistency check of this construction we estimate the in-medium reduction of
+the nucleon pole mass.",2308.16594v1
+2023-08-31,Neutron Star vs Quark Star in the Multimessenger Era,"Neutron stars (NSs) which could contain exotic degrees of freedom in the core
+and the self-bound quark stars (QSs) made purely of absolutely stable
+deconfined quark matter are still two main candidates for the compact objects
+observed in pulsars and gravitational wave (GW) events in binary star mergers.
+We perform a Bayesian model-agnostic inference of the properties of NSs and QSs
+by combining multi-messenger data of GW170817, GW190425, PSR J0030+0451, PSR
+J0740+6620, PSR J1614-2230, PSR J0348+0432 as well as ab initio calculations
+from perturbative quantum chromodynamics and chiral effective field theory. We
+find the NS scenario is strongly favored against the QS scenario with a Bayes
+factor of NS over QS $\mathcal{B}^\text{NS}_\text{QS} = 11.5$. In addition, the
+peak of the squared sound velocity $c_s^2 \sim 0.5c^2$ around $3.5$ times
+nuclear saturation density $n_0$ observed in the NS case disappears in the QS
+case which suggests that the $c_s^2$ first increases and then saturates at
+$c_s^2 \sim 0.5c^2$ above $\sim 4n_0$. The sound velocity and trace anomaly are
+found to approach the conformal limit in the core of heavy NSs with mass $M
+\gtrsim 2M_{\odot}$, but not in the core of QSs.",2308.16783v1
+2023-09-05,Enumeration of saturated and unsaturated substituted N-heterocycles,"Mathematical and computational approaches in chemistry and biochemistry fill
+a gap in respect to the analysis of the physicochemical features of compounds
+and their functionality and provide an overview of known as well as yet
+unknown, but hypothetically possible structures. Nitrogen containing
+heterocycles such as aziridine, azetidine and pyrrolidine bear a high potential
+in pharmacology, biotechnology and synthetic biology. Here, we present a
+mathematical enumeration procedure for all possible azaheterocycles with at
+least one substituent depending on the number of atoms in the ring, in the
+sense of saturated and unsaturated congeners. One subgroup belonging to that
+substance class is constituted by ring-shaped amino acids with a secondary
+amino group such as proline. A recursion formula is derived, which results in a
+modified Lucas number series. Moreover, an explicit formula for determining the
+number of such substances based on the Golden Ratio is given and a second one,
+based on binomial coefficients, is newly derived. This enumeration is a helpful
+tool for construction or complementation of virtual compound databases and for
+computer-assisted chemical synthesis route planning.",2309.02343v1
+2023-09-06,Dynamic scaling relation in quantum many-body systems,"In delocalized systems, particle number fluctuations, also known as quantum
+surface roughness, and the mean-square displacement exhibit a temporal
+power-law growth followed by a saturation to a system-size-dependent value. We
+use simple scaling arguments to show that these quantities satisfy the
+Family-Vicsek scaling law and derive a dynamic scaling relation between the
+dynamical exponents, assuming that the saturation times of both quantities
+scale similarly with the system size. This relation clarifies the mechanism
+behind quantum surface roughness growth and suggests that diffusive quantum
+many-body systems belong to the Edwards-Wilkinson universality class. Moreover,
+it provides a convenient way to assess quantum transport in cold-atom
+experiments. We numerically verify our results by studying two non-interacting
+models and one interacting model having regimes with distinct dynamical
+exponents.",2309.03273v1
+2023-09-13,On Kostant's conjecture for components of $V(ρ)\otimes V(ρ)$,"For a complex simple Lie algebra $\mathfrak{g}$ or rank $r$, let $\rho$ be
+the half sum of positive roots and $P(2\rho)\subset \mathbb{R}^r$ be the convex
+hull of all dominant weights $\lambda$ of the form $\lambda=2\rho-\sum_{i=1}^r
+a_i\alpha_i$ with $a_i\in \mathbb{Z}_{\geq 0}$ for $1\leq i\leq r$.
+  We show that if $\lambda$ is a vertex of $P(2\rho)$, then $V(\lambda)$
+appears in $V(\rho) \otimes V(\rho)$ with multiplicity one, proving partially
+(for the vertices of $P(2\rho)$) a conjecture of Kostant describing components
+of $V(\rho)\otimes V(\rho)$. This result allows us to give an alternative proof
+for a weaker form of the conjecture (up to saturation factor) for any
+$\mathfrak{g}$. Further, using works of Knutson-Tau on the saturation property
+of $\mathfrak{sl_{r+1}}$, our results give an alternative proof of Kostant's
+conjecture in the particular case $\mathfrak{g}=\mathfrak{sl_{r+1}}$.",2309.06890v2
+2023-09-16,gym-saturation: Gymnasium environments for saturation provers (System description),"This work describes a new version of a previously published Python package -
+gym-saturation: a collection of OpenAI Gym environments for guiding
+saturation-style provers based on the given clause algorithm with reinforcement
+learning. We contribute usage examples with two different provers: Vampire and
+iProver. We also have decoupled the proof state representation from
+reinforcement learning per se and provided examples of using a known ast2vec
+Python code embedding model as a first-order logic representation. In addition,
+we demonstrate how environment wrappers can transform a prover into a problem
+similar to a multi-armed bandit. We applied two reinforcement learning
+algorithms (Thompson sampling and Proximal policy optimisation) implemented in
+Ray RLlib to show the ease of experimentation with the new release of our
+package.",2309.09022v1
+2023-10-02,"High-energy picosecond pulses with a single spatial mode from a passively mode-locked, broad-area semiconductor laser","We present a mode-locked semiconductor laser oscillator that emits few
+picosecond pulses (5-8ps at 379MHz repetition) with record peak power (112W)
+and pulse energy (0.5nJ) directly out of the oscillator (with no amplifier). To
+achieve this high power performance we employ a high-current broad-area,
+spatially multi-mode diode amplifier (0.3x5mm), placed in an external cavity
+that enforces oscillation in a single spatial mode. Consequently, the
+brightness of the beam is near-ideal ($M^2 = 1.3$). Mode locking is achieved by
+dividing the large diode chip (edge emitter) into two sections with independent
+electrical control: one large section for gain and another small section for a
+saturable absorber. Precise tuning of the reverse voltage on the absorber
+section allows to tune the saturation level and recovery time of the absorber,
+which provides a convenient control knob to optimize the mode-locking
+performance for various cavity conditions.",2310.01229v1
+2023-10-04,On extra dimensions and the cosmological constant problem,"We consider a massive scalar field with a coordinate-dependent mass in
+higher-dimensional spacetime. The field satisfies Dirichlet boundary conditions
+on a brane representing the four-dimensional world. Despite being massive, the
+theory is scale-invariant. We quantize the theory calculating the zero-point
+energy. We find the lower bound for the uncertainty product in the uncertainty
+principle. We show that the zero-point energy density could be small if large
+extra dimensions exist. Identifying the zero-point energy as a source of dark
+energy, we extract the four-dimensional cosmological constant from
+higher-dimensional theory, considering quantum fluctuations close to the brane
+surface. We examine numerically ten- and eleven-dimensional spaces. The
+resulting zero-point energy is parameterized by the number of extra dimensions
+and the additional dimensionless {\it saturation parameter}, expressing the
+deviation from perfect saturation of the uncertainty principle. Letting the
+parameter to be small and of order of the fine-structure constant, we reproduce
+the experimental value of the cosmological constant in four dimensions.",2310.02837v2
+2023-10-10,Silent White Light,"We investigate the intra-waveguide statistics manipulation of broadband light
+by combining semiconductor quantum dot physics with quantum optics. By cooling
+a quantum dot superluminescent diode to liquid nitrogen temperature of $77K$,
+Blazek et al. [Phys. Rev. A 84, 63840 (2011)] have demonstrated a
+temperature-dependent reduction of the second-order intensity correlation
+coefficient from two for thermal amplified spontaneous emission light to
+$g^{(2)}(T=190 K)\approx 1.33$. Here, we model the broadband photon statistics
+assuming amplified spontaneous emission radiation in a pumped, saturable
+quantum dot gain medium. We demonstrate that, by an intensity increase due to
+the quantum dot occupation dynamics via the temperature-tuned quasi Fermi
+levels, together with the saturation nonlinearity, a statistics manipulation
+from thermal Bose-Einstein statistics towards Poissonian statistics can be
+realized, thus producing ""silent white light"". Such intensity-noise reduced
+broadband radiation is relevant for many applications like optical coherence
+tomography, optical communication or optical tweezers.",2310.06834v1
+2023-10-14,Safe Region Multi-Agent Formation Control With Velocity Tracking,"This paper provides a solution to the problem of safe region formation
+control with reference velocity tracking for a second-order multi-agent system
+without velocity measurements. Safe region formation control is a control
+problem where the agents are expected to attain the desired formation while
+reaching the target region and simultaneously ensuring collision and obstacle
+avoidance. To tackle this control problem, we break it down into two distinct
+objectives: safety and region formation control, to provide a completely
+distributed algorithm. Region formation control is modeled as a high-level
+abstract objective, whereas safety and actuator saturation are modeled as a
+low-level objective designed independently, without any knowledge of the
+former, and being minimally invasive. Our approach incorporates connectivity
+preservation, actuator saturation, safety considerations, and lack of velocity
+measurement from other agents with second-order system dynamics which are
+important constraints in practical applications. Both internal safety for
+collision avoidance among agents and external safety for avoiding unsafe
+regions are ensured using exponential control barrier functions. We provide
+theoretical results for asymptotic convergence and numerical simulation to show
+the approach's effectiveness.",2310.09681v1
+2023-10-16,Performance Enhancement via XPM Suppression in a Linear all-PM NPE Mode-locked Fiber Oscillator,"We demonstrate strong performance enhancement of an all
+polarization-maintaining fiber oscillator mode-locked using NPE in a linear
+self-stabilized fiber interferometer via suppression of cross-phase modulation
+(XPM). Numerical simulations reveal that XPM significantly affects the
+saturable absorber dynamics resulting in distortions of mode-locked
+steady-states. In the experiment, we construct an oscillator with XPM
+suppression, employing an intra-cavity YVO4 crystal, and compare its
+characteristics with a reference oscillator in standard configuration. It is
+shown, that XPM suppression not only lowers the mode-locking threshold by more
+than 40%, but further results in improved spectral pulse quality at the output
+ports and reduced nonlinear loss of the artificial saturable absorber.",2310.10164v1
+2023-10-17,Diffractive single hadron production in a saturation framework at the NLO,"We calculate the cross-sections of diffractive single hadron photo- or
+electroproduction with large $p_T$, on a nucleon or a nucleus in the shockwave
+formalism. We use the hybrid formalism mixing collinear factorization with high
+energy small-$x$ factorization with the impact factors computed at
+next-to-leading order accuracy. We prove the cancellation of divergence and we
+determine the finite parts of the differential cross-sections. We work in
+general kinematics such that both photoproduction and leptoproduction are
+considered. The results can be used to detect saturation effects, at both the
+future EIC or already at LHC, using Ultra-Peripheral Collisions.",2310.11066v2
+2023-10-19,High Dynamic Range mmWave Massive MU-MIMO with Householder Reflections,"All-digital massive multiuser (MU) multiple-input multiple-output (MIMO) at
+millimeter-wave (mmWave) frequencies is a promising technology for
+next-generation wireless systems. Low-resolution analog-to-digital converters
+(ADCs) can be utilized to reduce the power consumption of all-digital
+basestation (BS) designs. However, simultaneously transmitting user equipments
+(UEs) with vastly different BS-side receive powers either drown weak UEs in
+quantization noise or saturate the ADCs. To address this issue, we propose high
+dynamic range (HDR) MIMO, a new paradigm that enables simultaneous reception of
+strong and weak UEs with low-resolution ADCs. HDR MIMO combines an adaptive
+analog spatial transform with digital equalization: The spatial transform
+focuses strong UEs on a subset of ADCs in order to mitigate quantization and
+saturation artifacts; digital equalization is then used for data detection. We
+demonstrate the efficacy of HDR MIMO in a massive MU-MIMO mmWave scenario that
+uses Householder reflections as spatial transform.",2310.12835v3
+2023-10-19,Eureka-Moments in Transformers: Multi-Step Tasks Reveal Softmax Induced Optimization Problems,"In this work, we study rapid, step-wise improvements of the loss in
+transformers when being confronted with multi-step decision tasks. We found
+that transformers struggle to learn the intermediate tasks, whereas CNNs have
+no such issue on the tasks we studied. When transformers learn the intermediate
+task, they do this rapidly and unexpectedly after both training and validation
+loss saturated for hundreds of epochs. We call these rapid improvements
+Eureka-moments, since the transformer appears to suddenly learn a previously
+incomprehensible task. Similar leaps in performance have become known as
+Grokking. In contrast to Grokking, for Eureka-moments, both the validation and
+the training loss saturate before rapidly improving. We trace the problem back
+to the Softmax function in the self-attention block of transformers and show
+ways to alleviate the problem. These fixes improve training speed. The improved
+models reach 95% of the baseline model in just 20% of training steps while
+having a much higher likelihood to learn the intermediate task, lead to higher
+final accuracy and are more robust to hyper-parameters.",2310.12956v1
+2023-10-20,Terahertz Saturable Absorption from Relativistic High-Temperature Thermodynamics in Black Phosphorus,"Thanks to its tunable infrared band-gap and to its anisotropic conduction
+properties, black phosphorus represents a very unique 2D material, whose
+potential in the engineering of new devices still needs to be fully explored.
+We investigate here the nonlinear terahertz (THz) electrodynamics of black
+phosphorus along the more conducting armchair direction. Similarly to the case
+of other 2D systems like graphene and topological insulators, the THz saturable
+absorption properties of black phosphorus can be understood within a
+thermodynamic model by assuming a fast thermalization of the electron bath.
+While black phosphorus does not display the presence of massless fermions at
+ambient pressure and temperature, our analysis shows that its anomalous THz
+nonlinear properties can be accounted for by a relativistic massive Dirac
+dispersion, provided the Fermi temperature is low enough. An optimal tuning of
+the Fermi level therefore represents a strategy to engineer strong THz
+nonlinear response in other massive Dirac materials as in transition metal
+dichalchogenides or high-temperature superconductors.",2310.13587v1
+2023-10-27,Nonadiabatic nonlinear non-Hermitian quantized pumping,"We analyze a quantized pumping in a nonlinear non-Hermitian photonic system
+with nonadiabatic driving. The photonic system is made of a waveguide array,
+where the distances between adjacent waveguides are modulated. It is described
+by the Su-Schrieffer-Heeger model together with a saturated nonlinear gain term
+and a linear loss term. A topological interface state between the topological
+and trivial phases is stabilized by the combination of a saturated nonlinear
+gain term and a linear loss term. We study the pumping of the topological
+interface state. We define the transfer-speed ratio $\omega /\Omega $ by the
+ratio of the pumping speed $% \omega $ of the center of mass of the wave packet
+to the driving speed $ \Omega $ of the topological interface. It is quantized
+as $\omega /\Omega =1$ in the adiabatic limit. It remains to be quantized for
+slow driving even in the nonadiabatic regime, which is a nonadiabatic quantized
+pump. On the other hand, there is almost no pump for fast driving. We find a
+transition in pumping as a function of the driving speed.",2310.17987v1
+2023-10-27,Entanglement entropy of proton and its relation to thermodynamics entropy,"I discuss the thermodynamics-based derivation of the formula for the
+entanglement entropy of a system of gluons. The derivation is based on
+\cite{Kutak:2011rb}, where saturation and the Unruh effect were used to obtain
+and discuss the entropy of gluons. The formula agrees, in the high-energy
+limit, up to a numerical factor, with more recent results by
+\cite{Kharzeev:2017qzs}, where arguments based on the density matrix and
+bipartition of the proton were used to obtain the formula. Furthermore, I
+present arguments based on the properties of evolution equations as to why the
+saturation-based approach, as well as the double leading logarithmic limit of
+BFKL, agree in the functional form of the expression for entanglement entropy.",2310.18510v2
+2023-10-30,"Scalar field, nucleon structure and relativistic chiral theory for nuclear matter","The work that Peter Schuck and I carried out during the nineties in
+collaboration with the Lyon and Darmstadt theory groups is summarized. I
+retrace how our theoretical developments combined with experimental results
+concerning the in-medium modification of the pion-pion interaction allowed a
+clarification of the chiral status of the sigma meson introduced in
+relativistic theories of nuclear matter. This enabled us to build a
+relativistic chiral theory, now called the chiral confining model of nuclear
+matter, which includes the effect of the nucleon substructure, namely the
+response of the nucleon to the nuclear scalar field generating an efficient and
+natural contribution to the saturation mechanism. Using parameters from a
+QCD-connected version of the chiral confining model, I describe the relative
+roles of the chiral scalar field and two-pion (or two-rho) exchange for the
+in-medium $NN$ attractive interaction and the associated sources of three-body
+interactions needed for the saturation mechanism.",2310.19532v1
+2023-11-20,Nonlinear Optical Trapping of Gold Nanoparticles,"This paper presents the most complete framework to date for understanding the
+nonlinear optical trapping of highly absorbing nanoparticles within the dipole
+regime. Highly absorbing and plasmonic particles garner considerable interest
+due to their enhanced optical interactions, yet traditional linear theory fails
+to predict their trapping behavior, particularly in the longitudinal direction.
+We introduce a more comprehensive theory that incorporates four-wave mixing and
+two-photon absorption, addressing significant gaps in the current literature.
+Our research shows TPA to be crucial for longitudinal trapping stability.
+Furthermore, our findings propose a novel phenomenon of multiple split traps in
+both saturable absorption and reverse saturable absorption regimes. Our
+framework extends beyond existing models by including factors such as
+self-induced back-action and scattering forces, aligning theoretical
+predictions with experimental observations, and laying a robust foundation for
+future nonlinear optical trapping and manipulation research.",2311.12135v1
+2023-11-27,Effects of hyperon potentials and symmetry energy in quark deconfinement,"In this letter we discuss how the results of recent nuclear experiments that
+correspond to measurements at low densities can affect the equation of state at
+large densities and temperatures, changing the particle composition and
+ultimately influencing deconfinement to quark matter. In particular, saturation
+values of the hyperon potentials affect the hyperon content, while the symmetry
+energy at saturation directly regulates how the stiffness of the equation of
+state changes with isospin. We make use of a chiral model that describes
+nucleons, hyperons, and quarks to show how astrophysical conditions, such as
+the ones in neutron stars, present the ideal ground to study the effects of
+these two quantities in dense matter. In this case, for small charge fraction/
+large isospin asymmetry, the couplings that reproduce different symmetry energy
+slopes can significantly modify deconfinement, with quantitative changes in the
+critical chemical potential depending on the deconfining potential. On the
+other hand, different values of the parameter that controls the hyperon
+potentials (kept within a range close to experimental data) do not affect
+deconfinement significantly.",2311.15968v3
+2023-12-06,Implications of Gamma Ray Burst GRB221009A for Extra Dimensions,"Anomalous high energy photons, known as GRB221009A, with 18 TeV and 251 TeV
+were observed by LHAASO and Carpet-2 recently. Such observation of high energy
+gamma-ray bursts from distant source causes a mystery since high energy photons
+suffer severe attenuation before reaching the earth. One possibility is the
+existence of axion-like particles (ALP), and high energy photons at the source
+can convert to these ALPs which travel intergalactically. In this paper, we
+study the effects of extra dimensions on the conversion probability between
+photon and ALPs. The conversion probability saturates and may reach almost
+$100\%$ for high energy photons. We show that the size of extra dimension
+affects the energy at which saturation occurs. The observations of high-energy
+photons may support the possibility of smaller extra dimension.",2312.03314v1
+2023-12-07,Energy dependent nuclear suppression from gluon saturation in exclusive vector meson production,"We calculate the exclusive $\mathrm{J}/\psi$ photoproduction cross section at
+high energies from the Color Glass Condensate approach. The results are
+compared to the center-of-mass energy dependent $\gamma+A\to\mathrm{J}/\psi+A$
+cross sections extracted from measurements in ultra peripheral heavy ion
+collisions at RHIC and LHC. We predict strong saturation-driven nuclear
+suppression at high energies, while LHC data prefers even stronger suppression.
+We explore the effect of nucleon shape fluctuations on the nuclear suppression
+in the coherent and incoherent cross sections, and show that the most recent
+measurement of the $|t|$-differential incoherent $\mathrm{J}/\psi$ cross
+section prefers large event-by-event fluctuations of the nucleon substructure
+in heavy nuclei, comparable to that found for a free proton.",2312.04194v1
+2023-12-11,Cryogenic RPWELL: a novel charge-readout element for dual-phase argon TPCs,"The first operation of a cryogenic Resistive Plate WELL (RPWELL) detector in
+the saturated vapor of liquid argon is reported. The RPWELL detector was
+composed of a Thick Gas Electron Multiplier (THGEM) electrode coupled to a
+metallic anode via Fe$_2$O$_3$/YSZ ceramics (Fe$_2$O$_3$ in weight equal to
+75$\%$), with tunable bulk resistivity in the range 10$^{9}$ - 10$^{12}$
+$\Omega\cdot$cm. The detector was operated at liquid argon temperature in
+saturated argon vapor (90~K, 1.2~bar) and characterized in terms of its
+effective charge gain and stability against discharges. Maximum stable gain of
+G$\approx$17 was obtained, without discharges. In addition, preliminary results
+from novel 3D-printed thermoplastic plates doped with carbon nanotubes are
+presented.",2312.06809v1
+2023-12-13,Mapping the influence of impurities with varying interaction strength on nucleation in the 2D Ising model,"We study nucleation of magnetisation reversal in the two dimensional Ising
+model at non-zero external field and in the presence of randomly placed static
+and dynamic impurities. Impurity-spin interaction strengths are varied fixing
+other interaction strengths. We observe a decrease in the nucleation rate when
+the total interaction strength with impurities is decreased in the case of
+static impurities. The nucleation rate saturates with respect to interaction
+strength when the impurity density is low. However the nucleation rate does not
+saturate for high impurity density. Similar behaviour is observed with dynamic
+impurities both at low and high densities. We explore a broad range of both
+spin-symmetric and spin-antisymmetric interaction strengths and map the regime
+for which the impurities act as a surfactant, decreasing the surface energy of
+the nucleating phase. We also characterise different nucleation regimes
+observed at different values of interaction strength. These include regimes
+where impurities are included or excluded from the nucleus, and a region in
+which we observe cross nucleation of impurity clusters at the nucleus boundary.",2312.08342v1
+2023-12-14,Anisotropic swelling due to hydration in fibrous biomaterials,"Naturally occurring protein fibres often undergo anisotropic swelling when
+hydrated. Within a tendon, a hydrated collagen fibril's radius expands by 40\%
+but its length only increases by 5\%. The same effect, with similar magnitude,
+is observed for keratin microfibrils within hair. Nevertheless, current
+explanations for swelling anisotropy are based on molecular details that are
+unique to each material. Here, we describe a coarse-grained liquid-crystalline
+elastomer model for biomaterial hydration that allows for anisotropic swelling.
+We show that our model is consistent with previously observed behavior for both
+hair fibers and collagen fibrils. Despite a non-linear relationship between
+water saturation and relative humidity, we find that the squared deformation in
+the axial and radial directions is approximately linear with water saturation.
+We further find that anisotropic swelling is linear with respect to volume and
+shape changes. Hair and collagen exhibit remarkably similar behavior under
+hydration. We suggest that our model may also be useful for other biomaterials
+that exhibit anisotropic swelling.",2312.08771v1
+2023-12-18,Krylov complexity for non-local spin chains,"Building upon recent research in spin systems with non-local interactions,
+this study investigates operator growth using the Krylov complexity in
+different non-local versions of the Ising model. We find that the non-locality
+results in a faster scrambling of the operator to all sites. While the
+saturation value of Krylov complexity of local integrable and local chaotic
+theories differ by a significant margin, this difference is much suppressed
+when non-local terms are introduced in both regimes. This results from the
+faster scrambling of information in the presence of non-locality. In addition,
+we investigate the behavior of level statistics and spectral form factor as
+probes of quantum chaos to study the integrability breaking due to non-local
+interactions. Our numerics indicate that in the non-local case, late time
+saturation of Krylov complexity distinguishes between different underlying
+theories, while the early time complexity growth distinguishes different
+degrees of non-locality.",2312.11677v2
+2023-12-19,Solvable entanglement dynamics in quantum circuits with generalized dual unitarity,"We study the non-equilibrium dynamics of kicked Ising models in $1+1$
+dimensions which have interactions alternating between odd and even bonds in
+time. These models give rise to time-evolution equivalent to quantum circuits
+having both the global property of tri-unitarity (three 'arrows of time') and
+also the local property of second-level dual-unitarity, which constrains the
+behavior of pairs of local gates underlying the circuit under a space-time
+rotation. We identify a broad class of initial product states wherein the
+effect of the environment on a small subsystem can be exactly represented by
+influence matrices with simple Markovian structures, resulting in the
+subsystem's full dynamics being efficiently computable. We further find
+additional conditions under which the dynamics of entanglement can be solved
+for all times, yielding rich phenomenology ranging from linear growth at half
+the maximal speed allowed by locality, followed by saturation to maximum
+entropy (i.e., thermalization to infinite temperature); to entanglement growth
+with saturation to extensive but sub-maximal entropy. Our findings extend our
+knowledge of interacting quantum systems whose thermalizing dynamics can be
+efficiently and analytically computed, going beyond the well-known examples of
+integrable models, Clifford circuits, and dual-unitary circuits.",2312.12239v1
+2023-12-19,The entanglement membrane in exactly solvable lattice models,"Entanglement membrane theory is an effective coarse-grained description of
+entanglement dynamics and operator growth in chaotic quantum many-body systems.
+The fundamental quantity characterizing the membrane is the entanglement line
+tension. However, determining the entanglement line tension for microscopic
+models is in general exponentially difficult. We compute the entanglement line
+tension in a recently introduced class of exactly solvable yet chaotic unitary
+circuits, so-called generalized dual-unitary circuits, obtaining a non-trivial
+form that gives rise to a hierarchy of velocity scales with $v_E<v_B$. We find
+that these circuits saturate certain bounds on entanglement growth that are
+also saturated in holographic models. Furthermore, we relate the entanglement
+line tension to temporal entanglement and correlation functions. We also find
+new methods of constructing generalized dual-unitary gates beyond qubits that
+display behavior unique to local dimension $\geq3$. Our results shed light on
+entanglement membrane theory in microscopic Floquet lattice models and enable
+us to perform non-trivial checks on the validity of its predictions by
+comparison to exact and numerical calculations.",2312.12509v1
+2023-12-19,"An integrated EOS, pore-crush, strength and damage model framework for near-field ground-shock","An integrated Equation of State (EOS) and strength/pore-crush/damage model
+framework is provided for modeling near to source (near-field) ground-shock
+response, where large deformations and pressures necessitate coupling EOS with
+pressure-dependent plastic yield and damage. Nonlinear pressure-dependence of
+strength up to high-pressures is combined with a Modified Cam-Clay-like
+cap-plasticity model in a way to allow degradation of strength from pore-crush
+damage, what we call the ""Yp-Cap"" model. Nonlinear hardening under compaction
+allows modeling the crush-out of pores in combination with a fully saturated
+EOS, i.e., for modeling partially saturated ground-shock response, where
+air-filled voids crush. Attention is given to algorithmic clarity and
+efficiency of the provided model, and the model is employed in example
+numerical simulations, including finite element simulations of underground
+explosions to exemplify its robustness and utility.",2312.12577v2
+2023-12-29,Latent Idiom Recognition for a Minimalist Functional Array Language using Equality Saturation,"Accelerating programs is typically done by recognizing code idioms matching
+high-performance libraries or hardware interfaces. However, recognizing such
+idioms automatically is challenging. The idiom recognition machinery is
+difficult to write and requires expert knowledge. In addition, slight
+variations in the input program might hide the idiom and defeat the recognizer.
+  This paper advocates for the use of a minimalist functional array language
+supporting a small, but expressive, set of operators. The minimalist design
+leads to a tiny sets of rewrite rules, which encode the language semantics.
+Crucially, the same minimalist language is also used to encode idioms. This
+removes the need for hand-crafted analysis passes, or for having to learn a
+complex domain-specific language to define the idioms.
+  Coupled with equality saturation, this approach is able to match the core
+functions from the BLAS and PyTorch libraries on a set of computational
+kernels. Compared to reference C kernel implementations, the approach produces
+a geometric mean speedup of 1.46x for C programs using BLAS, when generating
+such programs from the high-level minimalist language.",2312.17682v1
+2023-12-31,Improvement on the Linearity Response of PandaX-4T with new Photomultiplier Tubes Bases,"With the expanding reach of physics, xenon-based detectors such as PandaX-4T
+in the China Jinping Underground Laboratory aim to cover an energy range from
+sub-keV to multi-MeV. A linear response of the photomultiplier tubes (PMTs) is
+required for both scintillation and electroluminescence signals. Through a
+dedicated bench test, we investigated the cause of the non-linear response in
+the Hamamatsu R11410-23 PMTs used in PandaX-4T. The saturation and suppression
+of the PMT waveform observed during the commissioning of PandaX-4T were caused
+by the high-voltage divider base. The bench test data validated the
+de-saturation algorithm used in the PandaX-4T data analysis. We also confirmed
+the improvement in linearity of a new PMT base design, which will be used to
+upgrade the PMT readout system in PandaX-4T.",2401.00373v1
+2024-01-26,Newton polytopes of dual $k$-Schur polynomials,"Rado's theorem about permutahedra and dominance order on partitions reveals
+that each Schur polynomial is M-convex, or equivalently, it has a saturated
+Newton polytope and this polytope is a generalized permutahedron as well. In
+this paper we show that the support of each dual $k$-Schur polynomial indexed
+by a $k$-bounded partition coincides with that of the Schur polynomial indexed
+by the same partition, and hence the two polynomials share the same saturated
+Newton polytope. The main result is based on our recursive algorithm to
+generate a semistandard $k$-tableau for a given shape and $k$-weight. As
+consequences, we obtain the M-convexity of dual $k$-Schur polynomials, affine
+Stanley symmetric polynomials and cylindric skew Schur polynomials.",2401.14632v1
+2024-01-28,New exact analytical solution of the nonlinear Gribov-Levin-Ryskin-Mueller-Qiu equation,"The GLR-MQ equation is a nonlinear evolution equation that takes into account
+the shadowing effect, which tames the growth of the gluon at small-$x$. In this
+study, we analytically solve for the first time the nonlinear GLR-MQ equation
+using the homogeneous balance method. The definite solution of the GLR-MQ
+equation is obtained by fitting the MSTW2008LO gluon distribution data. We find
+that the geometric scaling is an intrinsic property of our analytical solution
+and the gluon distribution functions from our solution are able to reproduce
+the MSTW2008LO data. These results indicate that our analytical solution from
+the homogeneous balance method is valid to describe the gluon behavior at
+small-$x$. Moreover, the saturation scale $Q_s$ has been extracted from our
+analytical solution, we find that the energy-dependent saturation scale obeys
+the exponential law $Q_s^2\,\propto\,Q_0^2 e^{\lambda Y}$.",2401.15651v1
+2024-01-28,Improvements of readout signal integrity in mid-infrared superconducting nanowire single photon detectors,"Superconducting nanowire single-photon detectors (SNSPDs) with high timing
+resolution and low background counts in the mid infrared (MIR) have the
+potential to open up numerous opportunities in fields such as exoplanet
+searches, direct dark matter detection, physical chemistry, and remote sensing.
+One challenge in pushing SNSPD sensitivity to the MIR is a decrease in the
+signal-to-noise ratio (SNR) of the readout signal as the critical currents
+become increasingly smaller. We overcome this trade-off with a new device
+architecture that employs impedance matching tapers and superconducting
+nanowire avalanche photodetectors to demonstrate increased SNR while
+maintaining saturated internal detection efficiency at 7.4 {\mu}m and getting
+close to saturation at 10.6 {\mu}m. This work provides a novel platform for
+pushing SNSPD sensitivity to longer wavelengths while improving the scalability
+of the readout electronics.",2401.15764v1
+2024-01-29,A theory-independent bound saturated by quantum mechanics,"Tsirelson's original inequality for the precession protocol, first introduced
+for the harmonic oscillator but applicable to all uniformly-precessing systems,
+serves as a monopartite test of quantumness. Given that the system is
+undergoing a uniform precession, the signs of the positions of a classical
+oscillator must satisfy that inequality, which is violated by certain quantum
+states. We consider this inequality for measurements with finitely many
+outcomes in a theory-independent manner. We derive a general bound which
+depends only on the minimum positive and negative values of the spectrum of the
+observable. Given any such two values, we construct a quantum observable that
+saturates this bound. A notable example is the angular momentum of a spin-$3/2$
+particle. We also relate our findings to the recently-introduced notion of
+constrained conditional probabilities.",2401.16147v1
+2023-12-25,New characterizations for supersolvability of fusion system and $p$-nilpotency of finite groups,"Let $p$ be a prime, $S$ be a $p$-group and $\mathcal{F}$ be a saturated
+fusion system over $S$. Then $\mathcal{F}$ is said to be supersolvable, if
+there exists a series of $S$, namely $1 = S_0 \leq S_1 \leq \cdots \leq S_n =
+S$, such that $S_{i+1}/S_i$ is cyclic, $i=0,1,\cdots, n-1$, $S_i$ is strongly
+$\mathcal{F}$-closed, $i=0,1,\cdots,n$. In this paper, we investigate the
+characterizations for supersolvability of $\mathcal{F}_S (G)$ under the
+assumption that certain subgroups of $G$ satisfy different kinds of generalized
+normalities in section \ref{1003}. Moreover, we obtain the more advanced and
+remarkable result of characterizations for generalized saturated fusion system
+$\mathcal{F}$ in section \ref{Section 4}. Finally, we apply the results in
+section \ref{1003} and \ref{Section 4} and give characterizations for
+$p$-nilpotency of finite groups under the assumption that some subgroups of $G$
+satisfy different kinds of generalized normalities.",2402.01073v3
+2024-02-02,Confinement in the Transverse Field Ising model on the Heavy Hex lattice,"We study the emergence of confinement in the transverse field Ising model on
+a decorated hexagonal lattice. Using an infinite tensor network state optimised
+with belief propagation we show how a quench from a broken symmetry state leads
+to striking nonthermal behaviour underpinned by persistent oscillations and
+saturation of the entanglement entropy. We explain this phenomenon by
+constructing a minimal model based on the confinement of elementary
+excitations, which take the form of various flavors of hadronic quasiparticles
+due to the unique structure of the lattice. Our model is in excellent agreement
+with our numerical results. For quenches to larger values of the transverse
+field and/or from non-symmetry broken states, our numerical results displays
+the expected signatures of thermalisation: a linear growth of entanglement
+entropy in time, propagation of correlations and the saturation of observables
+to their thermal averages. These results provide a physical explanation for the
+unexpected simulability of a recent large scale quantum computation.",2402.01558v2
+2024-02-02,Efficiency of neural quantum states in light of the quantum geometric tensor,"Neural quantum state (NQS) ans\""atze have shown promise in variational Monte
+Carlo algorithms by their theoretical capability of representing any quantum
+state. However, the reason behind the practical improvement in their
+performance with an increase in the number of parameters is not fully
+understood. In this work, we systematically study the efficiency of restricted
+Boltzmann Machines (RBMs) to represent the ground states in different phases of
+the spin-1 bilinear-biquadratic model, as the hidden layer density $\alpha$
+increases. We train our ansatz by minimizing two different loss functions: 1)
+energy, and 2) infidelity of the NQS ansatz w.r.t. that of the exact ground
+state. We observe that the accuracy of our ansatz saturates with $\alpha$ in
+both cases. We demonstrate that this can be explained by looking at the
+spectrum of the quantum geometric tensor (QGT). We find that the rank of the
+QGT saturates beyond a certain $\alpha$, and we emphasize that it corresponds
+to the \textit{dimension of the relevant manifold} for an optimized NQS. This
+provides a useful diagnostics for the practical representation power of an NQS
+ansatz.",2402.01565v2
+2024-02-05,Nonlocal growth of quantum conditional mutual information under decoherence,"Local measurements cannot create entanglement, but they can convert
+short-range entanglement to long-range entanglement, as in quantum
+teleportation. This phenomenon of measurement-induced entanglement (MIE) has
+been widely discussed in recent work on measurement-induced entanglement phase
+transitions and related phenomena. Here, we situate MIE in a broader context of
+the growth of long-range conditional mutual information (CMI) under
+decoherence. We upper-bound the rate at which decoherence can generate
+long-range CMI, and derive a characterization of states that saturate this
+bound. We point out that the structure of states saturating the CMI upper bound
+can be very different under different decoherent dynamics and provide explicit
+examples. We additionally explore the dynamics of CMI in random quantum
+circuits subject to random local decoherence, as a function of circuit depth.
+We argue that the universality class of the finite-depth teleportation
+transition, as well as its lower critical dimension, are different for erasures
+than for measurements.",2402.03439v1
+2024-03-12,Predicting the Slowing of Stellar Differential Rotation by Instability-Driven Turbulence,"Differentially rotating stars and planets transport angular momentum
+internally due to turbulence at rates that have long been a challenge to
+predict reliably. We develop a self-consistent saturation theory, using a
+statistical closure approximation, for hydrodynamic turbulence driven by the
+axisymmetric Goldreich--Schubert--Fricke (GSF) instability at the stellar
+equator with radial differential rotation. This instability arises when fast
+thermal diffusion eliminates the stabilizing effects of buoyancy forces in a
+system where a stabilizing entropy gradient dominates over the destabilizing
+angular momentum gradient. Our turbulence closure invokes a dominant three-wave
+coupling between pairs of linearly unstable eigenmodes and a near-zero
+frequency, viscously damped eigenmode that features latitudinal jets. We derive
+turbulent transport rates of momentum and heat, and provide them in analytic
+forms. Such formulae, free of tunable model parameters, are tested against
+direct numerical simulations; the comparison shows good agreement. They improve
+upon prior quasi-linear or ``parasitic saturation"" models containing a free
+parameter. Given model correspondences, we also extend this theory to heat and
+compositional transport for axisymmetric thermohaline instability-driven
+turbulence in certain regimes.",2403.07395v1
+2024-03-12,Maxwell's Demon at Work: Efficient Pruning by Leveraging Saturation of Neurons,"When training deep neural networks, the phenomenon of $\textit{dying
+neurons}$ $\unicode{x2013}$units that become inactive or saturated, output zero
+during training$\unicode{x2013}$ has traditionally been viewed as undesirable,
+linked with optimization challenges, and contributing to plasticity loss in
+continual learning scenarios. In this paper, we reassess this phenomenon,
+focusing on sparsity and pruning. By systematically exploring the impact of
+various hyperparameter configurations on dying neurons, we unveil their
+potential to facilitate simple yet effective structured pruning algorithms. We
+introduce $\textit{Demon Pruning}$ (DemP), a method that controls the
+proliferation of dead neurons, dynamically leading to network sparsity.
+Achieved through a combination of noise injection on active units and a
+one-cycled schedule regularization strategy, DemP stands out for its simplicity
+and broad applicability. Experiments on CIFAR10 and ImageNet datasets
+demonstrate that DemP surpasses existing structured pruning techniques,
+showcasing superior accuracy-sparsity tradeoffs and training speedups. These
+findings suggest a novel perspective on dying neurons as a valuable resource
+for efficient model compression and optimization.",2403.07688v1
+2024-03-22,A Surface Hydrothermal Source of Nitriles and Isonitriles,"Giant impacts can generate transient hydrogen-rich atmospheres, reducing
+atmospheric carbon. The reduced carbon will form hazes that rain out onto the
+surface and can become incorporated into the crust. Once heated, a large
+fraction of the carbon would be converted into graphite. The result is that
+local regions of the Hadean crust were plausibly saturated with graphite. We
+explore the consequences of such a crust for a prebiotic surface hydrothermal
+vent scenario. We model a surface vent fed by nitrogen-rich volcanic gas from
+high-temperature magmas passing through graphite-saturated crust. We consider
+this occurring at pressures of 1-1000 bar and temperatures of 1500-1700 degC.
+The equilibrium with graphite purifies the left-over gas, resulting in
+substantial quantities of nitriles (0.1% HCN and 1 ppm HC3N) and isonitriles
+(0.01% HNC) relevant for prebiotic chemistry. We use these results to predict
+gas-phase concentrations of methyl isonitrile of ~ 1 ppm. Methyl isocyanide can
+participate in the non-enzymatic activation and ligation of the monomeric
+building blocks of life, and surface, or shallow, hydrothermal environments
+provide its only known equilibrium geochemical source.",2403.15135v2
+2024-03-31,There and Back Again: A Netlist's Tale with Much Egraphin',"EDA toolchains are notoriously unpredictable, incomplete, and error-prone;
+the generally-accepted remedy has been to re-imagine EDA tasks as compilation
+problems. However, any compiler framework we apply must be prepared to handle
+the wide range of EDA tasks, including not only compilation tasks like
+technology mapping and optimization (the ""there""} in our title), but also
+decompilation tasks like loop rerolling (the ""back again""). In this paper, we
+advocate for equality saturation -- a term rewriting framework -- as the
+framework of choice when building hardware toolchains. Through a series of case
+studies, we show how the needs of EDA tasks line up conspicuously well with the
+features equality saturation provides.",2404.00786v1
+2024-04-01,Universal Bound on Effective Central Charge and Its Saturation,"The effective central charge (denoted by $c_{\text{eff}}$) is a measure of
+entanglement through a conformal interface, while the transmission coefficient
+(encoded in the coefficient $c_{LR}$ of the two-point function of the
+energy-momentum tensor across the interface) is a measure of energy
+transmission through the interface. It has been pointed out that these two are
+generally different. In this article, we propose the inequalities, $0 \leq
+c_{LR} \leq c_{\text{eff}} \leq \min (c_L,c_R)$. They have the simple but
+important implication that the amount of energy transmission can never exceed
+the amount of information transmission. We verify them using the AdS/CFT
+correspondence and in examples beyond holography. We also show that these
+inequalities are sharp by constructing a class of interfaces that saturate
+them.",2404.01515v1
+2024-04-04,Nuclear Matter Equation of State in the Brueckner-Hartree-Fock Approach and Standard Skyrme Energy-Density Functionals,"The equation of state of asymmetric nuclear matter as well as the neutron and
+proton effective masses and their partial-wave and spin-isospin decomposition
+are analyzed within the Brueckner--Hartree--Fock approach. Theoretical
+uncertainties for all these quantities are estimated by using several
+phase-shift-equivalent nucleon-nucleon forces together with two types of
+three-nucleon forces, phenomenological and microscopic. It is shown that the
+choice of the three-nucleon force plays an important role above saturation
+density, leading to different density dependencies of the energy per particle.
+These results are compared to the standard form of the Skyrme energy-density
+functional and we find that it is not possible to reproduce the BHF predictions
+in the $(S,T)$ channels in symmetric and neutron matter above saturation
+density, already at the level of the two-body interaction, and even more
+including the three-body interaction.",2404.03583v1
+2003-05-06,How Spectral Shapes of Magnetic Energy and Magnetic Helicity Influence their Respective Decay Time Scales,"It is shown that in magnetohydrodynamics, the shapes of the magnetic energy
+and magnetic helicity spectra can influence whether the magnetic helicity
+resistive dissipation time scale is longer, equal to, or shorter than that of
+magnetic energy. The calculations highlight that magnetic helicity need not
+always dissipate significantly more slowly than magnetic energy. While this may
+be implicitly understood in detailed studies of magnetic helicity in plasma
+devices, it is not sufficiently emphasized in elementary discussions comparing
+magnetic helicity vs. magnetic energy evolution. Measuring magnetic energy and
+helicity decay times may provide a posteriori insight into the initial spectra.",0305069v2
+2000-04-26,Magnetic relaxation and magnetization field dependence measurements in La0.5Ca0.5MnO3,"We reported a systematic change in the average magnetic relaxation rate,
+after the application and removal of a 5 T magnetic field, in a polycrystalline
+sample of La0.5Ca0.5MnO3. Magnetic relaxation measurements and magnetization
+versus field curves were taken from 10 K to 160 K. The long time behavior of
+the relaxation curves was approximately logarithmic in all cases. Keywords:
+Charge Ordering, Relaxation, Magnetic measurements",0004460v2
+2004-08-30,Optical Studies of Zero-Field Magnetization of CdMnTe Quantum Dots: Influence of Average Size and Composition of Quantum Dots,"We show that through the resonant optical excitation of spin-polarized
+excitons into CdMnTe magnetic quantum dots, we can induce a macroscopic
+magnetization of the Mn impurities. We observe very broad (4 meV linewidth)
+emission lines of single dots, which are consistent with the formation of
+strongly confined exciton magnetic polarons. Therefore we attribute the
+optically induced magnetization of the magnetic dots results to the formation
+of spin-polarized exciton magnetic polarons. We find that the photo-induced
+magnetization of magnetic polarons is weaker for larger dots which emit at
+lower energies within the QD distribution. We also show that the photo-induced
+magnetization is stronger for quantum dots with lower Mn concentration, which
+we ascribe to weaker Mn-Mn interaction between the nearest neighbors within the
+dots. Due to particular stability of the exciton magnetic polarons in QDs,
+where the localization of the electrons and holes is comparable to the magnetic
+exchange interaction, this optically induced spin alignment persists to
+temperatures as high as 160 K.",0408658v1
+2005-04-23,New Method to Calculate the Sign and Relative Strength of Magnetic Interactions in Low-Dimensional Systems on the Basis of Structural Data,"The connection of strength of magnetic interactions and type ordering the
+magnetic moments with crystal chemical characteristics in low-dimensional
+magnets is investigated. The new method to calculate the sign and relative
+strength of magnetic interactions in low-dimensional systems on the basis of
+the structural data is proposed. This method allows to estimate magnetic
+interactions not only inside low-dimensional fragments but also between them,
+and also to predict the possibility of the occurrence of magnetic phase
+transitions and anomalies of the magnetic interactions. Moreover, it can be
+used for search of low-dimensional magnets among the compounds whose crystal
+structures are known. The possibilities of the method are illustrated in an
+example of research of magnetic interactions in familiar low-dimensional
+magnets SrCu2(BO3)2, CaCuGe2O6, CaV4O9, Cu2Te2O5Cl2, Cu2Te2O5Br2, BaCu2Si2O7,
+BaCu2Ge2O7, BaCuSi2O6, LiCu2O2, and NaCu2O2.",0504599v3
+2006-02-14,Semiclassical pseudodifferential calculus and the reconstruction of a magnetic field,"We give a procedure for reconstructing a magnetic field and electric
+potential from boundary measurements related to the magnetic Schroedinger
+operator in three and higher dimensions.",0602290v1
+1999-01-29,Gravimetric Measurement of Magnetic Field Gradient Spatial Distribution,"Magnetic interaction between a weighing sample and an external magnetic field
+allows to measure characteristics of magnetic field (a sample with known
+magnetic characteristics), as well as the magnetic properties of a sample (a
+known magnetic field). Measurement of materials magnetic permeability is a well
+known application of this method. In this paper we restrict ourselves to the
+measurement of magnetic field spatial distribution, which was achieved by
+scanning of samples from known materials along the vertical axis. Field
+measurements by Hall detector were done to calibrate obtained data. Such
+measurements are of great interest in some branches of physics, in particular,
+in accelerator physics, where the quality of magnetic system parts eventually
+determine the quality of accelerated bunches. Development of a simple and cheep
+device for measurement of magnetic field spatial distribution is an urgent
+problem. The developed system for gravimetric measurement of magnetic field
+gradients partially solves this problem.",9901058v1
+1999-05-06,A Brief Note on Jupiter's Magnetism,"A recent model which gives the contribution of the earth's solid core to geo
+magnetism is seen to explain Jupiter's magnetism also.",9905014v1
+2008-01-30,How to use magnetic field information for coronal loop identification?,"The structure of the solar corona is dominated by the magnetic field because
+the magnetic pressure is about four orders of magnitude higher than the plasma
+pressure. Due to the high conductivity the emitting coronal plasma (visible
+e.g. in SOHO/EIT) outlines the magnetic field lines. The gradient of the
+emitting plasma structures is significantly lower parallel to the magnetic
+field lines than in the perpendicular direction. Consequently information
+regarding the coronal magnetic field can be used for the interpretation of
+coronal plasma structures. We extrapolate the coronal magnetic field from
+photospheric magnetic field measurements into the corona. The extrapolation
+method depends on assumptions regarding coronal currents, e.g. potential fields
+(current free) or force-free fields (current parallel to magnetic field). As a
+next step we project the reconstructed 3D magnetic field lines on an EIT-image
+and compare with the emitting plasma structures. Coronal loops are identified
+as closed magnetic field lines with a high emissivity in EIT and a small
+gradient of the emissivity along the magnetic field.",0801.4573v1
+2011-02-23,Possibility of conversion of neutron star to quark star in presence of high magnetic field,"Recent results and data suggests that high magnetic field in neutron stars
+(NS) strongly affects the characteristic (radius, mass) of the star. They are
+even separated as a class known as magnetars, for whom the surface magnetic
+field are greater than $10^{14}$ G. In this work we discuss the effect of such
+high magnetic field on the phase transition of NS to quark star (QS). We study
+the effect of magnetic field on the transition from NS to QS including the
+magnetic field effect in equation of state (EoS). The inclusion of the magnetic
+field increases the range of baryon number density, for which the flow
+velocities of the matter in the respective phase are finite. The magnetic field
+helps in initiation of the conversion process. The velocity of the conversion
+front however decreases due to the presence of magnetic field, as the presence
+of magnetic field reduces the effective pressure (P). The magnetic field of the
+star gets decreased by the conversion process, and the resultant QS has lower
+magnetic field than that of the initial NS.",1102.4660v2
+2011-03-06,"The Influence of Magnetic Anisotropy on the Kondo Effect and Spin-Polarized Transport through Magnetic Molecules, Adatoms and Quantum Dots","Transport properties in the Kondo regime of a nanosystem displaying uniaxial
+magnetic anisotropy (such as a magnetic molecule, magnetic adatom or quantum
+dot coupled to a localized magnetic moment) are analyzed theoretically. In
+particular, the influence of spin-polarized transport through a local orbital
+of the system and exchange coupling of conduction electrons to the system's
+magnetic core on the Kondo effect is discussed. The numerical renormalization
+group method is applied to calculate the spectral functions and linear
+conductance in the case of the parallel and antiparallel configurations of the
+electrodes' magnetic moments. It is shown that both the magnetic anisotropy as
+well as the exchange coupling between electrons tunneling through the
+conducting orbital and magnetic core play an important role in formation of the
+Kondo resonance, leading generally to its suppression. Specific transport
+properties of such a system appear also as a nontrivial behavior of tunnel
+magnetoresistance. It is also shown that the Kondo effect can be restored by an
+external magnetic field in both the parallel and antiparallel magnetic
+configurations.",1103.1128v2
+2011-03-18,Study of the interplay between magnetic shear and resonances using Hamiltonian models for the magnetic field lines,"The issue of magnetic confinement in magnetic fusion devices is addressed
+within a purely magnetic approach. Using some Hamiltonian models for the
+magnetic field lines, the dual impact of low magnetic shear is shown in a
+unified way. Away from resonances, it induces a drastic enhancement of magnetic
+confinement that favors robust internal transport barriers (ITBs) and
+stochastic transport reduction. When low-shear occurs for values of the winding
+of the magnetic field lines close to low-order rationals, the amplitude
+thresholds of the resonant modes that break internal transport barriers by
+allowing a radial stochastic transport of the magnetic field lines may be quite
+low. The approach can be applied to assess the robustness versus magnetic
+perturbations of general (almost) integrable magnetic steady states, including
+non-axisymmetric ones such as the important single helicity steady states. This
+analysis puts a constraint on the tolerable mode amplitudes compatible with
+ITBs and may be proposed as a possible explanation of diverse experimental and
+numerical signatures of their collapses.",1103.3595v1
+2012-04-26,Axisymmetric and stationary structures of magnetized barotropic stars with extremely strong magnetic fields deep inside,"We have succeeded in obtaining magnetized star models that have extremely
+strong magnetic fields in the interior of the star. In our formulation,
+arbitrary functions of the magnetic flux function appear in the expression for
+the current density. By appropriately choosing the functional form for one of
+the arbitrary functions that corresponds to the distribution of the toroidal
+current density, we have obtained configurations with magnetic field
+distributions that are highly localized within the central part and near the
+magnetic axis region. The absolute values of the central magnetic fields are
+stronger than those of the surface region by two orders of magnitude. By
+applying our results to magnetars, the internal magnetic poloidal fields could
+be 10^17 G, although the surface magnetic fields are about 10^15 G in the case
+of magnetars. For white dwarfs, the internal magnetic poloidal fields could be
+10^12 G, when the surface magnetic fields are 10^9-10^10 G .",1204.5830v2
+2014-08-05,Tunable asymmetric magnetoimpedance effect in ferromagnetic NiFe/Cu/Co films,"We investigate the magnetization dynamics through the magnetoimpedance effect
+in ferromagnetic NiFe/Cu/Co films. We observe that the magnetoimpedance
+response is dependent on the thickness of the non-magnetic Cu spacer material,
+a fact associated to the kind of the magnetic interaction between the
+ferromagnetic layers. Thus, we present an experimental study on asymmetric
+magnetoimpedance in ferromagnetic films with biphase magnetic behavior and
+explore the possibility of tuning the linear region of the magnetoimpedance
+curves around zero magnetic field by varying the thickness of the non-magnetic
+spacer material, and probe current frequency. We discuss the experimental
+magnetoimpedance results in terms of the different mechanisms governing the
+magnetization dynamics at distinct frequency ranges, quasi-static magnetic
+properties, thickness of the non-magnetic spacer material, and the kind of the
+magnetic interaction between the ferromagnetic layers. The results place
+ferromagnetic films with biphase magnetic behavior exhibiting asymmetric
+magnetoimpedance effect as a very attractive candidate for application as probe
+element in the development of auto-biased linear magnetic field sensors.",1408.0992v1
+2014-10-10,Comparison of adjustable permanent magnetic field sources,"A permanent magnet assembly in which the flux density can be altered by a
+mechanical operation is often significantly smaller than comparable
+electromagnets and also requires no electrical power to operate. In this paper
+five permanent magnet designs in which the magnetic flux density can be altered
+are analyzed using numerical simulations, and compared based on the generated
+magnetic flux density in a sample volume and the amount of magnet material
+used. The designs are the concentric Halbach cylinder, the two half Halbach
+cylinders, the two linear Halbach arrays and the four and six rod mangle. The
+concentric Halbach cylinder design is found to be the best performing design,
+i.e. the design that provides the most magnetic flux density using the least
+amount of magnet material. A concentric Halbach cylinder has been constructed
+and the magnetic flux density, the homogeneity and the direction of the
+magnetic field are measured and compared with numerical simulation and a good
+agreement is found.",1410.2681v1
+2014-11-25,Computing with spins and magnets,"The possible use of spin and magnets in place of charge and capacitors to
+store and process information is well known. Magnetic tunnel junctions are
+being widely investigated and developed for magnetic random access memories.
+These are two terminal devices that change their resistance based on switchable
+magnetization of magnetic materials. They utilize the interaction between
+electron spin and magnets to read information from the magnets and write onto
+them. Such advances in memory devices could also translate into a new class of
+logic devices that offer the advantage of nonvolatile and reconfigurable
+information processing over transistors. Logic devices having a transistor-like
+gain and directionality could be used to build integrated circuits without the
+need for transistor-based amplifiers and clocks at every stage. We review
+device characteristics and basic logic gates that compute with spins and
+magnets from the mesoscopic to the atomic scale, as well as materials,
+integration, and fabrication challenges and methods.",1411.6960v1
+2015-02-27,RC-circuit-like dynamic characteristic of the magnetic domain wall in ferromagnetic nanowires,"We have investigated dynamic behaviors of the magnetic domain wall under
+perpendicular magnetic field pulses in ferromagnetic nanowires using
+micromagnetic simulations. It has been found that the perpendicular magnetic
+field pulse can trigger the magnetic domain wall motion, where all the field
+torques are kept to be on the plane of nanowire strip. The magnetic domain wall
+speed faster than several hundreds meters per second is predicted without the
+Walker breakdown for the perpendicular magnetic driving field stronger than
+$200~\mathrm{mT}$. Interestingly, the dynamic behavior of the moving magnetic
+domain wall driven by perpendicular magnetic field pulses is explained by
+charging- and discharging-like behaviors of an electrical RC-circuit model,
+where the charging and the discharging of ""magnetic charges"" on the nanowire
+planes are considered. The concept of the RC-model-like dynamic characteristic
+of the magnetic domain wall might be promising for spintronic functional device
+applications based on the magnetic domain wall motion.",1502.07807v1
+2015-03-30,Effects of non-radial magnetic field on measuring magnetic helicity transport across solar photosphere,"It is generally believed that the evolution of magnetic helicity has a close
+relationship with solar activity. Before the launch of SDO, earlier studies
+have mostly used MDI/SOHO line of sight magnetograms and assumed that magnetic
+fields are radial when calculating magnetic helicity injection rate from
+photospheric magnetograms. However, this assumption is not necessarily true.
+Here we use the vector magnetograms and line of sight magnetograms, both taken
+by HMI/SDO, to estimate the effects of non-radial magnetic field on measuring
+magnetic helicity injection rate. We find that: 1) The effect of non-radial
+magnetic field on estimating tangential velocity is relatively small; 2) On
+estimating magnetic helicity injection rate, the effect of non-radial magnetic
+field is strong when active regions are observed near the limb and is
+relatively small when active regions are close to disk center; 3) The effect of
+non-radial magnetic field becomes minor if the amount of accumulated magnetic
+helicity is the only concern.",1503.08563v1
+2015-08-18,A self-consistent study of magnetic field effects on hybrid stars,"In this work we study the effects of strong magnetic fields on hybrid stars
+by using a full general-relativity approach, solving the coupled
+Maxwell-Einstein equation in a self-consistent way. The magnetic field is
+assumed to be axi-symmetric and poloidal. We take into consideration the
+anisotropy of the energy-momentum tensor due to the magnetic field, magnetic
+field effects on equation of state, the interaction between matter and the
+magnetic field (magnetization), and the anomalous magnetic moment of the
+hadrons. The equation of state used is an extended hadronic and quark SU(3)
+non-linear realization of the sigma model that describes magnetized hybrid
+stars containing nucleons, hyperons and quarks. According to our results, the
+effects of the magnetization and the magnetic field on the EoS do not play an
+important role on global properties of these stars. On the other hand, the
+magnetic field causes the central density in these objects to be reduced,
+inducing major changes in the populated degrees of freedom and, potentially,
+converting a hybrid star into a hadronic star.",1508.04431v1
+2015-09-05,Magnetic and magnetocaloric properties of quasi-one-dimensional Ising spin chain CoV$_{2}$O$_{6}$,"We have investigated the magnetic and magnetocaloric properties of
+antiferromagnetic Ising spin chain CoV$_{2}$O$_{6}$ by magnetization and heat
+capacity measurements. Both monoclinic $\alpha$-CoV$_{2}$O$_{6}$ and triclinic
+$\gamma$-CoV$_{2}$O$_{6}$ exhibit field-induced metamagnetic transition from
+antiferromagnetic to ferromagnetic state via an intermediate ferrimagnetic
+state with 1/3 magnetization plateau. Due to this field-induced metamagnetic
+transition, these systems show large conventional as well as inverse
+magnetocaloric effects. In $\alpha$-CoV$_{2}$O$_{6}$, we observe field-induced
+complex magnetic phases and multiple magnetization plateaux at low temperature
+when the field is applied along $c$ axis. Several critical temperatures and
+fields have been identified from the temperature and field dependence of
+magnetization, magnetic entropy change and heat capacity to construct the
+$H$-$T$ phase diagram. As compared to $\alpha$-CoV$_{2}$O$_{6}$,
+$\gamma$-CoV$_{2}$O$_{6}$ displays a relatively simple magnetic phase diagram.
+Due to the large magnetic entropy change and adiabatic temperature change at
+low or moderate applied magnetic field, $\gamma$-CoV$_{2}$O$_{6}$ may be
+considered as a magnetic refrigerant in the low-temperature region.",1509.01690v2
+2015-11-16,Observation of Magnetic Superviscosity in Metglas 2605SA1,"A quasi time constant for magnetic domain relaxation of Metglas 20605SA1 has
+been measured to be 2.6 hours. The effective relative magnetic permeability has
+been measured to be 57,000 after relaxation.",1511.05127v1
+2017-01-12,Interplay of iron and rare-earth magnetic order in rare-earth iron pnictide superconductors under magnetic field,"The magnetic properties of iron pnictide superconductors with magnetic
+rare-earth ions under strong magnetic field are investigated based on the
+cluster self-consistent field method. Starting from an effective Heisenberg
+model, we present the evolution of magnetic structures on magnetic field in
+RFeAsO (R=Ce, Pr, Nd, Sm, Gd and Tb) and RFe2As2 (R=Eu) compounds. It is found
+that spin-flop transition occurs in both rare-earth and iron layers under
+magnetic field, in good agreement with the experimental results. The interplay
+between rare-earth and iron spins plays a key role in the magnetic-field-driven
+magnetic phase transition, which suggests that the rare-earth layers can
+modulate the magnetic behaviors of iron layers. In addition, the factors that
+affect the critical magnetic field for spin-flop transition are also discussed.",1701.03258v1
+2017-01-19,Linear Stability Analysis of a Levitated Nanomagnet in a Static Magnetic Field: Quantum Spin Stabilized Magnetic Levitation,"We theoretically study the levitation of a single magnetic domain nanosphere
+in an external static magnetic field. We show that apart from the stability
+provided by the mechanical rotation of the nanomagnet (as in the classical
+Levitron), the quantum spin origin of its magnetization provides two additional
+mechanisms to stably levitate the system. Despite of the Earnshaw theorem, such
+stable phases are present even in the absence of mechanical rotation. For large
+magnetic fields, the Larmor precession of the quantum magnetic moment
+stabilizes the system in full analogy with magnetic trapping of a neutral atom.
+For low magnetic fields, the magnetic anisotropy stabilizes the system via the
+Einstein-de Haas effect. These results are obtained with a linear stability
+analysis of a single magnetic domain rigid nanosphere with uniaxial anisotropy
+in a Ioffe-Pritchard magnetic field.",1701.05410v3
+2017-02-28,Chemical Responsive Single Crystal Organic Magnet,"Materials that change their magnetic properties in response to the external
+stimuli have long been of interest for their potential applicability in
+magnetic storage device, spintronics and smart magnetic materials. Organic
+materials are suitable candidates for such materials due to their chemical
+diversity, flexibility and designablity. However, most methods used for
+changing magnetism are inefficient or destructive to the magnetic material.
+Hence there is a need for innovation in this field. Here we report
+high-performance magnetic control of a gas-responsive single-molecule magnet
+(SMM). The results exhibit that the magnetic properties of the SMM can be
+significantly changed according to the gas environment it is in and some of the
+magnetic states can be reversibly transformed or coexistent in the SMM through
+artificial control. More importantly, the monocrystalline structure of the SMM
+remains unchanged during the transformation process except for slight change of
+the lattice constant. Thus, this work opens up new insights into the
+stimuli-responsive magnetic materials which have great prospects for
+application in artificial design magnetic network and also highlight their
+potential as smart materials.",1703.00006v2
+2017-09-13,Contactless and absolute linear displacement detection based upon 3D printed magnets combined with passive radio-frequency identification,"Within this work a passive and wireless magnetic sensor, to monitor linear
+displacements is proposed. We exploit recent advances in 3D printing and
+fabricate a polymer bonded magnet with a spatially linear magnetic field
+component corresponding to the length of the magnet. Regulating the magnetic
+compound fraction during printing allows specific shaping of the magnetic field
+distribution. A giant magnetoresistance magnetic field sensor is combined with
+a radio-frequency identification tag in order to passively monitor the exerted
+magnetic field of the printed magnet. Due to the tailored magnetic field, a
+displacement of the magnet with respect to the sensor can be detected within
+the sub-mm regime. The sensor design provides good flexibility by controlling
+the 3D printing process according to application needs. Absolute displacement
+detection using low cost components and providing passive operation, long term
+stability and longevity renders the proposed sensor system ideal for structural
+health monitoring applications.",1709.04220v1
+2018-02-14,Axisymmetric magnetic modes of neutron stars having mixed poloidal and toroidal magnetic fields,"We calculate axisymmetric magnetic modes of a neutron star possessing a mixed
+poloidal and toroidal magnetic field, where the toroidal field is assumed to be
+proportional to a dimensionless parameter $\zeta_0$. Here, we assume an
+isentropic structure for the neutron star and consider no effects of rotation.
+Ignoring the equilibrium deformation due to the magnetic field, we employ a
+polytrope of the index $n=1$ as the background model for our modal analyses.
+For the mixed poloidal and toroidal magnetic field with $\zeta_0\not=0$,
+axisymmetric spheroidal and toroidal modes are coupled. We compute axisymmetric
+spheroidal and toroidal magnetic modes as a function of the parameter $\zeta_0$
+from $0$ to $\sim 1$ for the surface field strengths $B_S=10^{14}$G and
+$10^{15}$G. We find that the frequency $\omega$ of the magnetic modes decreases
+with increasing $\zeta_0$. We also find that the frequency of the spheroidal
+magnetic modes is almost exactly proportional to $B_S$ for $\zeta_0\lesssim 1$
+but that this proportionality holds only when $\zeta_0\ll 1$ for the toroidal
+magnetic modes. The wave patterns of the spheroidal magnetic modes and toroidal
+magnetic modes are not strongly affected by the coupling so long as
+$\zeta_0\lesssim 1$. We find no unstable modes having $\omega^2<0$.",1802.04957v1
+2018-05-07,Single-shot multi-level all-optical magnetization switching mediated by spin-polarized hot electron transport,"All-optical ultrafast magnetization switching in magnetic material thin film
+without the assistance of an applied external magnetic field is being explored
+for future ultrafast and energy-efficient magnetic storage and memories. It has
+been shown that femto-second light pulses induce magnetization reversal in a
+large variety of magnetic materials. However, so far, only GdFeCo-based
+ferrimagnetic thin films exhibit magnetization switching via a single optical
+pulse. Here we demonstrate the single-pulse switching of Co/Pt multilayers
+within a magnetic spin-valve structure ([Co/Pt] / Cu / GdFeCo) and further show
+that the four possible magnetic configurations of the spin valve can be
+accessed using a sequence of single femto-second light pulses. Our experimental
+study reveals that the magnetization final state of the ferromagnetic [Co/Pt]
+layer is determined by spin-polarized hot electrons generated by the light
+pulse interactions with the GdFeCo layer. This work provides a new approach to
+deterministically switch ferromagnetic layers and a pathway to engineering
+materials for opto-magnetic multi-bit recording.",1805.02432v1
+2018-09-19,Effect of external magnetic field on nucleon mass in hot and dense medium : Inverse Magnetic Catalysis in Walecka Model,"Vacuum to nuclear matter phase transition has been studied in presence of
+constant external background magnetic field with the mean field approximation
+in Walecka model. The anomalous nucleon magnetic moment has been taken into
+account using the modified ""weak"" field expansion of the fermion propagator
+having non-trivial correction terms for charged as well as for neutral
+particles. The effect of nucleon magnetic moment is found to favour the
+magnetic catalysis effect at zero temperature and zero baryon density. However,
+extending the study to finite temperatures, it is observed that the anomalous
+nuclear magnetic moment plays a crucial role in characterizing the qualitative
+behaviour of vacuum to nuclear matter phase transition even in case of the weak
+external magnetic fields . The critical temperature corresponding to the vacuum
+to nuclear medium phase transition is observed to decrease with the external
+magnetic field which can be identified as the inverse magnetic catalysis in
+Walecka model whereas the opposite behaviour is obtained in case of vanishing
+magnetic moment indicating magnetic catalysis.",1809.07028v1
+2018-12-13,Measuring Earth's Magnetic Field Using a Smartphone Magnetometer,"I use the magnetometers of a smartphone to measure the magnitude of the
+earth's magnetic field. A method for eliminating bias due to internal magnetic
+fields in the phone is proposed.",1901.00857v1
+2019-10-17,Magnetic textures and dynamics in magnetic Weyl semimetals,"Recent theoretical and experimental attemps have been successful in finding
+magnetic Weyl semimetal phases, which show both nodal-point structure in the
+electronic bands and magnetic orders. Beyond uniform ferromagnetic or
+antiferromagnetic orders, nonuniform magnetic textures, such as domain walls
+and skyrmions, may even more enrich the properties of the Weyl electrons in
+such materials. This article gives a topical review on interplay between Weyl
+electrons and magnetic textures in those magnetic Weyl semimetals. The basics
+of magnetic textures in non-topological magnetic metals are reviewed first, and
+then the effect of magnetic textures in Weyl semimetals is discussed, regarding
+the recent theoretical and experimental progress therein. The idea of the
+fictitious ""axial gauge fields"" is pointed out, which effectively describes the
+effect of magnetic textures on the Weyl electrons and can well account for the
+properties of the electrons localized around magnetic domain walls.",1910.07774v1
+2019-12-03,Magnetic Force Microscopy Revealing Molecule Impact on Magnetic Tunnel Junction Based Molecular Devices at Room Temperature,"Commercially successful magnetic tunnel junction can harness the unmatched
+capabilities of molecular device elements by solving decade-old fabrication
+issues. Utilization of magnetic tunnel junction as a testbed for molecules also
+enables unprecedented magnetic studies of molecular spintronics devices. This
+paper utilizes magnetic force microscopy (MFM) to vividly show that
+organometallic molecules when bridged between two ferromagnetic electrodes
+along the magnetic tunnel junction edges, transformed the magnetic electrodes
+itself. Molecules impacted several hundred-micron areas of ferromagnetic
+electrodes at room temperature. Complementary, magnetic resonance and
+magnetometer studies supported the dramatic MFM results. Molecule induced
+changes in the magnetic electrodes impacted the transport of the magnetic
+tunnel junction and stabilized as much as six orders smaller current at room
+temperature. Magnetic tunnel junction based molecular devices can be a gateway
+to a vast range of commercially viable futuristic logic and memory devices that
+are controlled by the molecular quantum states near room temperature.",1912.01316v1
+2019-12-12,Potential analysis of holographic Schwinger effect in the magnetized background,"We study the holographic Schwinger effect with magnetic field at RHIC and LHC
+energies by using the AdS/CFT correspondence. We consider both weak and strong
+magnetic field cases with $B\ll T^2$ and $B\gg T^2$ solutions respectively.
+Firstly, we calculate separating length of the particle pairs at finite
+magnetic field. It is found that for both weak and strong magnetic field
+solutions the maximum value of separating length decreases with the increase of
+magnetic field , which can be inferred that the virtual electron-positron pairs
+become real particles more easily. We also find that the magnetic field reduces
+the potential barrier and the critical field for the weak magnetic field
+solution, thus favors the Schwinger effect. With strong magnetic field
+solution, the magnetic field enhances the Schwinger effect when the pairs are
+in perpendicular to the magnetic field although the magnetic field increases
+the critical electric field.",1912.05806v2
+2019-12-24,The origin and effect of hemispheric helicity imbalance in solar dynamo,"In this paper we study the effects of hemispheric imbalance of magnetic
+helicity density on breaking the equatorial reflection symmetry of the dynamo
+generated large-scale magnetic field. Our study employs the axisymmetric dynamo
+model which takes into account the nonlinear effect of magnetic helicity
+conservation. We find that the evolution of the net magnetic helicity density,
+in other words, the magnetic helicity imbalance, on the surface follows the
+evolution of the parity of the large-scale magnetic field. Random fluctuations
+of the $\alpha$-effect and the helicity fluxes can inverse the causal
+relationship, i.e., the magnetic helicity imbalance or the imbalance of
+magnetic helicity fluxes can drive the magnetic parity breaking. We also found
+that evolution of the net magnetic helicity of the small-scale fields follows
+the evolution of the net magnetic helicity of the large-scale fields with some
+time lag. We interpret this as an effect of the difference of the magnetic
+helicity fluxes out of the Sun from the large and small scales.",1912.11285v2
+2020-03-09,Magnetic Noise Enabled Biocompass,"The discovery of magnetic protein provides a new understanding of a
+biocompass at the molecular level. However, the mechanism by which magnetic
+protein enables a biocompass is still under debate, mainly because of the
+absence of permanent magnetism in the magnetic protein at room temperature.
+Here, based on a widely accepted radical pair model of a biocompass, we propose
+a microscopic mechanism that allows the biocompass to operate without a finite
+magnetization of the magnetic protein in a biological environment. With the
+structure of the magnetic protein, we show that the magnetic fluctuation,
+rather than the permanent magnetism, of the magnetic protein can enable
+geomagnetic field sensing. An analysis of the quantum dynamics of our
+microscopic model reveals the necessary conditions for optimal sensitivity. Our
+work clarifies the mechanism by which magnetic protein enables a biocompass.",2003.13816v2
+2020-04-25,Pulse-assisted magnetization switching in magnetic nanowires at picosecond and nanosecond timescales with low energy,"Detailed understanding of spin dynamics in magnetic nanomaterials is
+necessary for developing ultrafast, low-energy and high-density spintronic
+logic and memory. Here, we develop micromagnetic models and analytical
+solutions to elucidate the effect of increasing damping and uniaxial anisotropy
+on magnetic field pulse-assisted switching time, energy and field requirements
+of nanowires with perpendicular magnetic anisotropy and yttrium iron
+garnet-like spin transport properties. A nanowire is initially magnetized using
+an external magnetic field pulse (write) and self-relaxation. Next, magnetic
+moments exhibit deterministic switching upon receiving 2.5 ns-long external
+magnetic pulses in both vertical polarities. Favorable damping
+({\alpha}~0.1-0.5) and anisotropy energies (10^4-10^5 J m^-3) allow for as low
+as picosecond magnetization switching times. Magnetization reversal with fields
+below coercivity was observed using spin precession instabilities. A
+competition or a nanomagnetic trilemma arises among the switching rate, energy
+cost and external field required. Developing magnetic nanowires with optimized
+damping and effective anisotropy could reduce the switching energy barrier down
+to 3163kBT at room temperature. Thus, pulse-assisted picosecond and low energy
+switching in nanomagnets could enable ultrafast nanomagnetic logic and cellular
+automata.",2004.12243v1
+2020-05-02,Optically driven ultrafast magnetic order transitions in two-dimensional ferrimagnets,"Laser-induced switching and manipulation of the spins in magnetic materials
+are of great interest to revolutionize future magnetic storage technology and
+spintronics with fastest speed and least power dissipative. Inspired by the
+recent discovery of intrinsic two-dimensional (2D) magnets, which provide
+unique platform to explore the new phenomenon for light-control magnetism in
+the 2D limit, we propose to realize light can efficiently tune magnetic
+properties of 2D ferrimagnets in early time. Here, using the 2D ferrimagnetic
+MXenes as prototype systems, our real-time density functional theory (TDDFT)
+simulation show that laser pulses can directly induce ultrafast spin-selective
+charge transfer between two magnetic sublattices on a few femtoseconds, and
+further generate dramatic changes in the magnetic structure of these MXenes,
+including a magnetic order transition from ferrimagnetic (FiM) to transient
+ferromagnetic (FM). The microscopic mechanism underpinning this ultrafast
+switching of magnetic order in MXenes is governed by optically induced
+inter-site spin transfer (OISTR) effect, which theoretically enables the
+ultrafast direct optical manipulation of the magnetic state in MXenes-based
+materials. Our results open new opportunities to optically manipulate the spin
+in 2D magnets.",2005.00871v1
+2020-06-03,Structural and magnetic properties of small symmetrical and asymmetrical sized fullerene dimers,"Magnetism in carbon nanostructures is of high scientific interest, which
+could lead to novel magnetic materials. The magnetic properties of symmetrical
+and asymmetrical sized small fullerene dimers have been investigated using spin
+polarized density functional theory. The interaction energies depict that small
+fullerene cages form stable dimer structures and symmetrical sized fullerene
+dimers are found more stable than asymmetrical sized dimers. The dimerization
+of fullerene cages in different modes leads to change in their magnetic
+properties. The non-magnetic fullerene cages become magnetic after formation of
+dimer (C20-C20, C24-C24, C32-C32, C40-C40, C20-C24, C40-C44 and
+C44-C50),whereas the magnetism of magnetic fullerenes is enhanced or lowered
+after dimerization (C28-C28 C36-C36, C24-C28, C28-C32, C32-C36 and C36-C40).
+The individual cages of dimer structures show ferromagnetic interactions
+amongst them and resultant magnetic moment strongly depends on the type of
+inter-connecting bonds. The magnetism may also be explained based on distortion
+of carbon cages and change in the density of states (DOS) in dimer
+configuration. The calculations presented show strong possibility of
+experimental synthesis of small fullerene based magnetic dimers.",2006.02233v1
+2020-09-03,Coincidence inelastic neutron scattering for detection of two-spin magnetic correlations,"Inelastic neutron scattering (INS) is one powerful technique to study the
+low-energy single-spin dynamics of magnetic materials. A variety of quantum
+magnets show novel magnetic correlations such as quantum spin liquids. These
+novel magnetic correlations are beyond the direct detection of INS. In this
+paper we propose a coincidence technique, coincidence inelastic neutron
+scattering (cINS), which can detect the two-spin magnetic correlations of the
+magnetic materials. In cINS there are two neutron sources and two neutron
+detectors with an additional coincidence detector. Two neutrons from the two
+neutron sources are incident on the target magnetic material, and they are
+scattered by the electron spins of the magnetic material. The two scattered
+neutrons are detected by the two neutron detectors in coincidence with the
+coincidence probability described by a two-spin Bethe-Salpeter wave function.
+Since the two-spin Bethe-Salpeter wave function defines the momentum-resolved
+dynamical wave function with two spins excited, cINS can explicitly detect the
+two-spin magnetic correlations of the magnetic material. Thus, it can be
+introduced to study the various spin valence bond states of the quantum
+magnets.",2009.01680v2
+2020-10-19,Magnetic texture based magnonics,"The spontaneous magnetic orders arising in ferro-, ferri- and
+antiferromagnets stem from various magnetic interactions. Depending on the
+interplay and competition among the Heisenberg exchange interaction,
+Dzyaloshinskii-Moriya exchange interaction, magnetic dipolar interaction and
+crystal anisotropies, a great variety of magnetic textures may be stabilized,
+such as magnetic domain walls, vortices, Skyrmions and spiral helical
+structures. While each of these spin textures responds to external forces in a
+specific manner with characteristic resonance frequencies, they also interact
+with magnons, the fundamental collective excitation of the magnetic order,
+which can propagate in magnetic materials free of charge transport and
+therefore with low energy dissipation. Recent theories and experiments found
+that the interplay between spin waves and magnetic textures is particularly
+interesting and rich in physics. In this review, we introduce and discuss the
+theoretical framework of magnons living on a magnetic texture background, as
+well as recent experimental progress in the manipulation of magnons via
+magnetic textures. The flexibility and reconfigurability of magnetic textures
+are discussed regarding the potential for applications in information
+processing schemes based on magnons.",2010.09180v1
+2020-12-09,Optimization of a NdFeB permanent magnet configuration for in-vivo drug delivery experiments,"We propose a new concept of magnetic focusing for targeting and accumulation
+of functionalized superparamagnetic nanoparticles in living organs through
+composite configurations of different permanent magnets. The proposed setups
+fulfill two fundamental requirements for in vivo experiments: 1) reduced size
+of the magnets to best focusing on small areas representing the targeted organs
+of mice and rats and 2) maximization of the magnetic driving force acting on
+the magnetic nanoparticles dispersed in blood. To this aim, several
+configurations of permanent magnets organized with different degrees of
+symmetry have been tested. The product B*grad(B) proportional to the magnetic
+force has been experimentally measured, over a wide area (20x20 mm^2), at a
+distance corresponding to the hypothetical distance of the mouse organ from the
+magnets. A non-symmetric configuration of mixed shape permanent magnets
+resulted in particularly promising to achieve the best performances for further
+in vivo experiments.",2012.05059v1
+2021-01-15,Magnetized Rutherford scattering angle for electron-ion collision in plasma,"Rutherford scattering formula plays an important role in plasma classical
+transport. It is urgent to need a magnetized Rutherford scattering formula
+since the magnetic field increases significantly in different fusion areas
+(e.g. tokamak magnetic field, self-generated magnetic field, and compressed
+magnetic field). The electron-ion Coulomb collisions perpendicular to the
+external magnetic field are studied in this paper. The scattering angle is
+defined according to the electron trajectory and asymptotic line (without
+magnetic field). A magnetized Rutherford scattering formula is obtained
+analytically under the weak magnetic field approximation. It is found that the
+scattering angle decreases as external magnetic field increases. It is easy to
+find the scattering angle decreasing significantly as incident distance, and
+incident velocity increasing. It is shown that the theoretical results agree
+well with numerical calculation by checking the dependence of scattering angle
+on external magnetic field.",2101.05943v1
+2021-04-02,Highly Complex Magnetic Structures Resulting From Hierarchical Phase Separation in AlCo(Cr)FeNi High Entropy Alloys,"Magnetic high entropy alloys (HEAs) are a new category of high-performance
+magnetic materials, with multi-component concentrated compositions and complex
+multi-phase structures. Although there have been numerous reports of their
+interesting magnetic properties, there is very limited understanding about the
+interplay between their hierarchical multi-phase structures and their local
+magnetic structures. By employing high spatial resolution correlative magnetic,
+structural and chemical studies, we reveal the influence of a hierarchically
+decomposed B2 + A2 structure in an AlCo0.5Cr0.5FeNi HEA on the formation of
+magnetic vortex states within individual A2 (disordered BCC) precipitates,
+which are distributed in an ordered B2 matrix that is weakly ferromagnetic.
+Non-magnetic or weakly ferromagnetic B2 precipitates in large magnetic domains
+of the A2 phase, and strongly magnetic Fe-Co-rich interphase A2 regions, are
+also observed. These results provide important insight into the origin of
+coercivity in this HEA, which can be attributed to a complex magnetization
+process that includes the successive reversal of magnetic vortices.",2104.00943v1
+2021-06-28,Stability of a Magnetically Levitated Nanomagnet in Vacuum: Effects of Gas and Magnetization Damping,"In the absence of dissipation a non-rotating magnetic nanoparticle can be
+stably levitated in a static magnetic field as a consequence of the spin origin
+of its magnetization. Here we study the effects of dissipation on the stability
+of the system, considering the interaction with the background gas and the
+intrinsic Gilbert damping of magnetization dynamics. At large applied magnetic
+fields we identify magnetization switching induced by Gilbert damping as the
+key limiting factor for stable levitation. At low applied magnetic fields and
+for small particle dimensions magnetization switching is prevented due to the
+strong coupling of rotation and magnetization dynamics, and the stability is
+mainly limited by the gas-induced dissipation. In the latter case, high vacuum
+should be sufficient to extend stable levitation over experimentally relevant
+timescales. Our results demonstrate the possibility to experimentally observe
+the phenomenon of quantum spin stabilized magnetic levitation.",2106.14858v3
+2021-12-21,Tunable room temperature magnetic skyrmions in centrosymmetric kagome magnet Mn$_4$Ga$_2$Sn,"The successful realization of skyrmion-based spintronic devices depends on
+the easy manipulation of underlying magnetic interactions in the
+skyrmion-hosting materials. Although the mechanism of skyrmion formation in
+non-centrosymmetric magnets is comprehensively established, the stabilization
+process of different skyrmion-like magnetic textures in centrosymmetric magnets
+needs further investigation. Here, we utilize Lorentz transmission electron
+microscopy study to report the finding of a tunable skyrmion lattice up to room
+temperature in a centrosymmetric kagome ferromagnet Mn$_4$Ga$_2$Sn. We
+demonstrate that a controlled switching between the topological skyrmions and
+non-topological type-II magnetic bubbles can be realized at the optimal
+magnetic anisotropy. We find that the topological skyrmions are the
+energetically most stable magnetic objects in the centrosymmetric hexagonal
+magnets, whereas application of in-plane magnetic field stabilizes type-II
+magnetic bubbles as an excited state. The present study is a significant step
+towards understanding of the skyrmion stabilization mechanism in
+centrosymmetric materials for their future applications.",2112.11259v2
+2022-02-25,Magnetic-Field-Dependent Thermodynamic Properties of Square and Quadrupolar Artificial Spin Ice,"Applied magnetic fields are an important tuning parameter for artificial spin
+ice (ASI) systems, as they can drive phase transitions between different
+magnetic ground states, or tune through regimes with high populations of
+emergent magnetic excitations (e.g., monopole-like quasiparticles). Here, using
+simulations supported by experiments, we investigate the thermodynamic
+properties and magnetic phases of square and quadrupolar ASI as a function of
+applied in-plane magnetic fields. Monte Carlo simulations are used to generate
+field-dependent maps of the magnetization, the magnetic specific heat, the
+thermodynamic magnetization fluctuations, and the magnetic order parameters,
+all under equilibrium conditions. These maps reveal the diversity of magnetic
+orderings and the phase transitions that occur in different regions of the
+phase diagrams of these ASIs, and are experimentally supported by
+magneto-optical measurements of the equilibrium ""magnetization noise"" in
+thermally-active ASIs.",2202.12486v1
+2022-03-23,R&D works for Superconducting Magnet for Future Accelerator Applications in Japan,"KEK cryogenics science center is developing superconducting magnet technology
+for future accelerator science. Three major technological categories are
+focused; 1) high precision 3D magnetic field technology based on the g-2/EDM
+magnet developments, 2) rad-hard superconducting magnet technology based on the
+COMET magnet developments, and 3) high magnetic field superconducting magnet
+technology for future colliders based on the LHC MQXA and HL-LHC D1 magnet
+developments. Extensive studies including Nb3Sn conductor and magnet
+developments for high field magnets and HTS for rad-hard superconducting
+magnets are ongoing with various collaboration programs such as the US-Japan
+research collaboration.",2203.12118v1
+2022-04-26,Slow spin dynamics and quantum tunneling of magnetization in the dipolar antiferromagnet DyScO$_3$,"We present a comprehensive study of static and dynamic magnetic properties in
+the Ising-like dipolar antiferromagnet (AFM) DyScO$_3$\ by means of DC and AC
+magnetization measurements supported by classical Monte-Carlo calculations. Our
+AC-susceptibility data show that the magnetic dynamics exhibit a clear
+crossover from an Arrhenius-like regime to quantum tunneling of magnetization
+(QTM) at $T^* = 10$ K. Below $T_{\mathrm{N}} = 3.2$ K DyScO$_3$ orders in an
+antiferromagnetic $GxAy$-type magnetic structure and the magnetization dynamics
+slow down to the minute timescale. The low-temperature magnetization curves
+exhibit complex hysteretic behavior, which depends strongly on the magnetic
+field sweep rate. We demonstrate that the low-field anomalies on the
+magnetization curve are related to the metamagnetic transition, while the
+hysteresis at higher fields is induced by a strong magnetocaloric effect. Our
+theoretical calculations, which take into account dipolar interaction between
+Dy$^{3+}$ moments, reproduce essential features of the magnetic behavior of
+DyScO$_3$. We demonstrate that DyScO$_3$ represents a rare example of inorganic
+compound, which exhibits QTM at a single-ion level and magnetic order due to
+classical dipolar interaction.",2204.12398v1
+2022-05-08,Two-dimensional characterization of three-dimensional magnetic bubbles in Fe$_3$Sn$_2$ nanostructures,"We report differential phase contrast scanning transmission electron
+microscopy (TEM) of nanoscale magnetic objects in Kagome ferromagnet
+Fe$_3$Sn$_2$ nanostructures. This technique can directly detect the deflection
+angle of a focused electron beam, thus allowing clear identification of the
+real magnetic structures of two magnetic objects including three-ring and
+complex arch-shaped vortices in Fe$_3$Sn$_2$ by Lorentz transmission electron
+microscopy imaging. Numerical calculations based on real material-specific
+parameters well reproduced the experimental results, showing that the magnetic
+objects can be attributed to integral magnetizations of two types of complex
+three-dimensional (3D) magnetic skyrmion bubbles with depth-modulated spin
+twisting. Magnetic configurations obtained using the high-resolution TEM are
+generally considered as two-dimensional (2D) magnetic objects previously. Our
+results imply the importance of the integral magnetizations of underestimated
+3D magnetic structures in 2D TEM magnetic characterizations.",2205.03751v2
+2022-05-09,"Controlling magnetic exchange and anisotropy by non-magnetic ligand substitution in layered MPX3 (M = Ni, Mn; X = S, Se)","Recent discoveries in two-dimensional (2D) magnetism have intensified the
+investigation of van der Waals (vdW) magnetic materials and further improved
+our ability to tune their magnetic properties. Tunable magnetism has been
+widely studied in antiferromagnetic metal thiophosphates MPX3. Substitution of
+metal ions M has been adopted as an important technique to engineer the
+magnetism in MPX3. In this work, we have studied the previously unexplored
+chalcogen X substitutions in MPX3 (M = Mn/Ni; X = S/Se). We synthesized the
+single crystals of MnPS3-xSex (0 < x < 3) and NiPS3-xSex (0 < x < 1.3) and
+investigated the systematic evolution of the magnetism with varying x. Our
+study reveals the effective tuning of magnetic interactions and anisotropies in
+both MnPS3 and NiPS3 upon Se substitution. Such efficient engineering of the
+magnetism provides a suitable platform to understand the low-dimensional
+magnetism and develop future magnetic devices.",2205.04585v1
+2022-05-28,Finite element simulation for validation of multi-dipole line cusp magnetic field configuration for MPD,"A Multi-dipole line cusp configured Plasma Device (MPD) having six
+electromagnets with embedded Vacoflux-50 as a core material has been operated
+with a capability to experimentally control the field-free region, the radial
+profile of magnetic field, and pole magnetic field by changing magnet current.
+For the validation of multi-dipole line cusp magnetic field (MMF) configuration
+in a 3-D geometry, a finite element simulation has been performed using COMSOL
+software. This paper presents 3-D magnetic field simulation results of
+multi-pole line cusp magnetic field configuration performed over the 1.2m
+length and 40cm diameter chamber in the vacuum condition. The simulation
+results show good agreement with the experimentally measured magnetic field
+profile. The performed magnetic field simulation results clearly capture that
+this configuration has full control over a null region (nearly field-free
+region) as well is capable to change the magnetic field values and radial
+variation of the magnetic field. Moreover, the magnetic field profiles over the
+end cross-section of the device have been discussed.",2205.14381v1
+2022-05-20,A Sacrificial Magnet Concept for Field Dependent Surface Science Studies,"We demonstrate a straightforward approach to integrating a magnetic field
+into a low-temperature scanning tunneling microscope (STM) by adhering an NdFeB
+permanent magnet to a magnetizable sample plate. To render our magnet concept
+compatible with high-temperature sample cleaning procedures, we make the
+irreversible demagnetization of the magnet a central part of our preparation
+cycle. After sacrificing the magnet by heating it above its Curie temperature,
+we use a transfer tool to attach a new magnet in-situ prior to transferring the
+sample into the STM. We characterize the magnetic field created by the magnet
+using the Abrikosov vortex lattice of superconducting NbSe2. Excellent
+agreement between the distance dependent magnetic fields from experiments and
+simulations allows us to predict the magnitude and orientation of magnetic flux
+at any location with respect to the magnet and the sample plate. Our concept is
+an accessible solution for field-dependent surface science studies that require
+fields in the range of up to 400 mT and otherwise detrimental heating
+procedures.",2206.02529v1
+2022-07-14,Formation of Quiescent Prominence Magnetic Field by Supergranulations,"To understand the formation of quiescent solar prominences, the origin of
+their magnetic field structures, i.e., magnetic flux ropes (MFRs), must be
+revealed. We use three-dimensional magnetofriction simulations in a spherical
+subdomain to investigate the role of typical supergranular motions in the
+long-term formation of a prominence magnetic field. Time-dependant horizontal
+supergranular motions with and without the effect of Coriolis force are
+simulated on the solar surface via Voronoi tessellation. The vortical motions
+by the Coriolis effect at boundaries of supergranules inject magnetic helicity
+into the corona. The helicity is transferred and accumulated along the polarity
+inversion line (PIL) as strongly sheared magnetic field via helicity
+condensation. The diverging motions of supergranules converge opposite magnetic
+polarities at the PIL and drive the magnetic reconnection between footpoints of
+the sheared magnetic arcades to form an MFR. The magnetic network,
+negative-helicity MFR in the northern hemisphere, and fragmented-to-continuous
+formation process of magnetic dip regions are in agreement with observations.
+Although diverging supergranulations, differential rotation, and meridional
+flows are included, the simulation without the Coriolis effect can not produce
+an MFR or sheared arcades to host a prominence. Therefore Coriolis force is a
+key factor for helicity injection and the formation of magnetic structures of
+quiescent solar prominences.",2207.06598v1
+2022-11-28,Algorithms for magnetic symmetry operation search and identification of magnetic space group from magnetic crystal structure,"A crystal symmetry search is crucial for computational crystallography and
+materials science. Although algorithms and implementations for the crystal
+symmetry search have been developed, their extension to magnetic space groups
+(MSGs) remains limited. In this paper, algorithms for determining magnetic
+symmetry operations of magnetic crystal structures, identifying magnetic
+space-group types of given MSGs, searching for transformations to a BNS
+setting, and symmetrizing the magnetic crystal structures using the MSGs are
+presented. The determination of magnetic symmetry operations is numerically
+stable and is implemented with minimal modifications from the existing crystal
+symmetry search. Magnetic space-group types and transformations to the BNS
+setting are identified by a two-step approach combining space-group type
+identification and the use of affine normalizers. Point coordinates and
+magnetic moments of the magnetic crystal structures are symmetrized by
+projection operators for the MSGs. An implementation is distributed with a
+permissive free software license in spglib v2.0.2:
+https://github.com/spglib/spglib.",2211.15008v2
+2023-02-22,Controllable CVD-Growth of 2D Cr5Te8 Nanosheets with Thickness-Dependent Magnetic Domains,"As a typical 2D magnetic material with self-intercalated structure, Cr5Te8
+exhibits many fascinating magnetic properties. Although the ferromagnetism of
+2D Cr5Te8 has been reported, the study of its magnetic domain is still blank.
+Herein, we successfully fabricated 2D Cr5Te8 nanosheets with controlled
+thickness and lateral size by chemical vapor deposition (CVD). Then magnetic
+property measurement system suggested Cr5Te8 nanosheets possessing intense
+out-of-plane ferromagnetism with the Curie temperature of 179 K. Most
+importantly, we found magnetic bubbles and thickness-dependent maze-like
+magnetic domains by cryogenic magnetic force microscopy (MFM) for the first
+time. The domain width of the maze-like magnetic domains increases rapidly with
+decreasing sample thickness, while domain contrast decreases. This indicates
+dipolar interaction is the dominant role over exchange interaction and magnetic
+anisotropy. Our work not only paves a way for the controllable growth of 2D
+magnetic materials, but also suggests new directions for controlling magnetic
+phases and systematically adjusting domain properties.",2302.11422v2
+2023-03-11,Magnetic field imaging by cosmic-ray muons (Magic-$μ$) -- First feasibility simulation for strong magnetic fields,"We have proposed a novel application for cosmic-ray muography, called
+Magic-$\mu$, which is short for Magnetic field Imaging by Cosmic-ray Muons. The
+general goal of Magic-$\mu$ is to detect the presence of a magnetic field or
+magnetic flux density whose three-dimensional distribution is unknown.
+Depending on the application, Magic-$\mu$ can have three detection modes. The
+first is ""magnetic field imaging,"" which is detecting the presence of a
+magnetic field in specific voxels within a region of space. The other two
+modes, transmission and deflection, aim not only to detect the presence but
+also to measure the flux density of the magnetic field. We have performed a
+feasibility study using the PHITS Monte Carlo simulation code, for strong and
+weak magnetic fields. In this paper, we first give an overview of the concept
+and basic principles of magnetic field muography. Then, the results of the
+feasibility study on magnetic field imaging for a strong magnetic field (more
+than 500 mT) are presented.",2303.06290v3
+2023-05-30,Magnetic field regression using artificial neural networks for cold atom experiments,"Accurately measuring magnetic fields is essential for magnetic-field
+sensitive experiments in fields like atomic, molecular, and optical physics,
+condensed matter experiments, and other areas. However, since many experiments
+are conducted in an isolated vacuum environment that is inaccessible to
+experimentalists, it can be challenging to accurately determine the magnetic
+field. Here, we propose an efficient method for detecting magnetic fields with
+the assistance of an artificial neural network (NN). Instead of measuring the
+magnetic field directly at the desired location, we detect magnetic fields at
+several surrounding positions, and a trained NN can accurately predict the
+magnetic field at the target location. After training, we achieve a relative
+error of magnetic field magnitude (magnitude of error over the magnitude of
+magnetic field) below 0.3$\%$, and we successfully apply this method to our
+erbium quantum gas apparatus. This approach significantly simplifies the
+process of determining magnetic fields in isolated vacuum environments and can
+be applied to various research fields across a wide range of magnetic field
+magnitudes.",2305.18822v1
+2023-07-06,Plasmon-enhanced optical control of magnetism at the nanoscale via the inverse Faraday effect,"The relationship between magnetization and light has been the subject of
+intensive research for the past century, focusing on the impact of magnetic
+moments on light polarization. Conversely, the manipulation of magnetism
+through polarized light is being investigated to achieve all-optical control of
+magnetism in spintronics. While remarkable discoveries such as single pulse
+all-optical switching of the magnetization in thin films and sub-micrometer
+structures have been reported, the demonstration of local optical control of
+magnetism at the nanoscale has remained elusive. Here, we show that exciting
+gold nanodiscs with circularly polarized femtosecond laser pulses leads to the
+generation of sizeable local magnetic fields that enable ultrafast local
+control of the magnetization of an adjacent magnetic film. In addition, we find
+that the highest magnetic fields are generated when exciting the sample at a
+wavelength larger than that of the actual plasmonic resonance of the gold
+nanodiscs, so avoiding undesired heating effects due to absorption. Our study
+paves the way for light-driven control in nanoscale spintronic devices and
+provides important insights into the generation of magnetic fields in plasmonic
+nanostructures.",2307.03326v1
+2023-07-14,Parker Bounds on Monopoles with Arbitrary Charge from Galactic and Primordial Magnetic Fields,"We present a comprehensive study of Parker-type bounds on magnetic monopoles
+with arbitrary magnetic charge, including minicharged monopoles and magnetic
+black holes. We derive the bounds based on the survival of galactic magnetic
+fields, seed magnetic fields, as well as primordial magnetic fields. We find
+that monopoles with different magnetic charges are best constrained by
+different astrophysical systems: while monopoles with a Dirac charge are
+tightly constrained by seed galactic magnetic fields, minicharged monopoles are
+strongly constrained by primordial magnetic fields, and magnetic black holes by
+the density of dark matter. We also assess the viability of the various types
+of monopoles as dark matter, by studying whether they can cluster with galaxies
+hosting magnetic fields.",2307.07553v2
+2023-10-10,Skyrmions and magnetic bubbles in spin-orbit coupled metallic magnets,"Motivated by the observation of Skyrmion-like magnetic textures in 2D
+itinerant ferromagnets Fe$_n$GeTe$_2$ ($n \geq3$), we develop a microscopic
+model combining itinerant magnetism and spin-orbit coupling on a triangular
+lattice. The ground state of the model in the absence of magnetic field
+consists of filamentary magnetic domain walls revealing a striking similarity
+with our magnetic force microscopy experiments on Fe$_3$GeTe$_2$. In the
+presence of magnetic field, these filaments were found to break into large size
+magnetic bubbles in our experiments. We identify uniaxial magnetic anisotropy
+as an important parameter in the model that interpolates between magnetic
+Skyrmions and ferromagnetic bubbles. Consequently, our work uncovers new
+topological magnetic textures that merge properties of Skyrmions and
+ferromagnetic bubbles.",2310.06521v1
+2023-11-10,Exchange stiffness proportional to power of magnetization in permalloy co-doped with Mo and Cu,"The exchange stiffness of magnetic materials is one of the essential
+parameters governing magnetic texture and its dynamics in magnetic devices. The
+effect of single-element doping on exchange stiffness has been investigated for
+several doping elements for permalloy (NiFe alloy), a soft magnetic material
+whose soft magnetic properties can be controlled by doping. However, the impact
+of more practical multi-element doping on the exchange stiffness of permalloy
+is unknown. This study investigates the typical magnetic properties, including
+exchange stiffness, of permalloy systematically co-doped with Mo and Cu using
+broadband ferromagnetic resonance spectroscopy. We find that the exchange
+stiffness, which decreases with increasing doping levels, is proportional to a
+power of magnetization, which also decreases with increasing doping levels. The
+magnetization, $M_{\rm s}$, dependence of the exchange stiffness constant, $A$,
+of all the investigated samples, irrespective of the doping levels of each
+element, lies on a single curve expressed as $A\propto M_{\rm s}^n$ with
+exponent $n$ close to 2. This empirical power-law relationship provides a
+guideline for predicting unknown exchange stiffness in non-magnetic
+element-doped permalloy systems.",2311.05852v2
+2024-02-18,Deep learning methods for Hamiltonian parameter estimation and magnetic domain image generation in twisted van der Waals magnets,"The application of twist engineering in van der Waals magnets has opened new
+frontiers in the field of two-dimensional magnetism, yielding distinctive
+magnetic domain structures. Despite the introduction of numerous theoretical
+methods, limitations persist in terms of accuracy or efficiency due to the
+complex nature of the magnetic Hamiltonians pertinent to these systems. In this
+study, we introduce a deep-learning approach to tackle these challenges.
+Utilizing customized, fully connected networks, we develop two
+deep-neural-network kernels that facilitate efficient and reliable analysis of
+twisted van der Waals magnets. Our regression model is adept at estimating the
+magnetic Hamiltonian parameters of twisted bilayer CrI3 from its magnetic
+domain images generated through atomistic spin simulations. The generative
+model excels in producing precise magnetic domain images from the provided
+magnetic parameters. The trained networks for these models undergo thorough
+validation, including statistical error analysis and assessment of robustness
+against noisy injections. These advancements not only extend the applicability
+of deep-learning methods to twisted van der Waals magnets but also streamline
+future investigations into these captivating yet poorly understood systems.",2402.11434v1
+2001-08-29,Jet Collimation by Small-Scale Magnetic Fields,"A popular model for jet collimation is associated with the presence of a
+large-scale and predominantly toroidal magnetic field originating from the
+central engine (a star, a black hole, or an accretion disk). Besides the
+problem of how such a large-scale magnetic field is generated, in this model
+the jet suffers from the fatal long-wave mode kink magnetohydrodynamic
+instability. In this paper we explore an alternative model: jet collimation by
+small-scale magnetic fields. These magnetic fields are assumed to be local,
+chaotic, tangled, but are dominated by toroidal components. Just as in the case
+of a large-scale toroidal magnetic field, we show that the ``hoop stress'' of
+the tangled toroidal magnetic fields exerts an inward force which confines and
+collimates the jet. The magnetic ``hoop stress'' is balanced either by the gas
+pressure of the jet, or by the centrifugal force if the jet is spinning. Since
+the length-scale of the magnetic field is small (< the cross-sectional radius
+of the jet << the length of the jet), in this model the jet does not suffer
+from the long-wave mode kink instability. Many other problems associated with
+the large-scale magnetic field are also eliminated or alleviated for
+small-scale magnetic fields. Though it remains an open question how to generate
+and maintain the required small-scale magnetic fields in a jet, the scenario of
+jet collimation by small-scale magnetic fields is favored by the current study
+on disk dynamo which indicates that small-scale magnetic fields are much easier
+to generate than large-scale magnetic fields.",0108469v1
+2003-10-20,Cyclic evolution and reversal of the solar magnetic field. I. The large-scale magnetic fields,"On the base of the solar magnetic field measurements obtained in Stanford in
+1976--2003 the properties of the cyclic evolution of the large-scale magnetic
+field are investigated. Some regularities are found in longitudinal and
+latitudinal evolution of the magnetic field in cycles 21, 22 and 23. The cyclic
+development of the large-scale magnetic field can be divided into two main
+phases. The phase I, which includes a period approximately from two years
+before and until three years after the maximum of the solar cycle, is studied
+in detail. It is found that before the reversal of the large-scale magnetic
+field the neutral line of the magnetic field in antipodal longitudinal
+intervals shifts from the equator to opposite directions in cycles 21 and 22,
+but not in cycle 23. During the sign reversal of the large-scale magnetic field
+in cycles 21 and 22 in the antipodal longitudinal intervals the magnetic field
+of opposite polarity is observed in all latitudes, thereby forming an
+equatorial dipole. After the magnetic field reversal a longitudinal oscillation
+of the magnetic neutral line with regard to the equator takes place, which has
+a period about 2 years and damps to the minimum of the 11-year cycle. The
+intervening longitudinal intervals of the large-scale magnetic field correspond
+to positions of the active longitudes of sunspot activity, thus indicating a
+close connection of the large-scale and the local magnetic fields. In evolution
+of the large-scale magnetic field a periodicity with period $1.23\pm0.16$ year
+is revealed, which is close to the period found by helioseismological methods
+in variations of the solar rotation near the tachocline.",0310539v1
+2009-03-16,Relationship between photospheric currents and coronal magnetic helicity for force-free bipolar fields,"The origin and evolution of the magnetic helicity in the solar corona are not
+well understood. For instance, the magnetic helicity of an active region is
+often about $10^{42}$ Mx$^2$ ($10^{26}$ Wb$^{2}$), but the observed processes
+whereby it is thought to be injected into the corona do not yet provide an
+accurate estimate of the resulting magnetic helicity budget or time evolution.
+The variation in magnetic helicity is important for understanding the physics
+of flares, coronal mass ejections, and their associated magnetic clouds. To
+shed light on this topic, we investigate here the changes in magnetic helicity
+due to electric currents in the corona for a single twisted flux tube that may
+model characteristic coronal structures such as active region filaments,
+sigmoids, or coronal loops. For a bipolar photospheric magnetic field and
+several distributions of current, we extrapolated the coronal field as a
+nonlinear force-free field. We then computed the relative magnetic helicity, as
+well as the self and mutual helicities. Starting from a magnetic configuration
+with a moderate amount of current, the amount of magnetic helicity can increase
+by 2 orders of magnitude when the maximum current strength is increased by a
+factor of 2. The high sensitivity of magnetic helicity to the current density
+can partially explain discrepancies between measured values on the photosphere,
+in the corona, and in magnetic clouds. Our conclusion is that the magnetic
+helicity strongly depends on both the strength of the current density and also
+on its distribution. Only improved measurements of current density at the
+photospheric level will advance our knowledge of the magnetic helicity content
+in the solar atmosphere.",0903.2697v1
+2011-03-29,Relationship between vertical and horizontal magnetic fields in the quiet Sun,"Vertical magnetic fields have been known to exist in the internetwork region
+for decades, while the properties of horizontal magnetic fields have recently
+been extensively investigated with \textit{Hinode}. Vertical and horizontal
+magnetic fields in the internetwork region are considered to be separate
+entities and have thus far not been investigated in a unified way. We discover
+clear positional association between the vertical and horizontal magnetic
+fields in the internetwork region with \textit{Hinode}. Essentially all of the
+horizontal magnetic patches are associated with the vertical magnetic patches.
+Alternatively, half of the vertical magnetic patches accommodate the horizontal
+magnetic patches. These horizontal patches are located around the borders of
+the vertical patches. The intrinsic magnetic field strength as obtained with
+the Stokes $V$ line ratio inside the horizontal patches is weak, and is in
+sub-equipartition field regime ($B<700$ G), while the field strength outside
+the horizontal patches ranges from weak to strong (kG) fields. Vertical
+magnetic patches are known to be concentrated on mesogranular and supergranular
+boundaries, while the horizontal magnetic patches are found only on the
+mesogranular boundaries. These observations provide us with new information on
+the origin of the vertical and horizontal internetwork magnetic fields, in a
+unified way. We conjecture that internetwork magnetic fields are provided by
+emergence of small-scale flux tubes with bipolar footpoints, and the vertical
+magnetic fields of the footpoints are intensified to kG fields due to
+convective collapse. Resultant strong vertical fields are advected by the
+supergranular flow, and eventually form the network fields.",1103.5556v1
+2011-11-15,Spin waves in nanosized magnetic films,"We have studied spin excitations in nanosized magnetic films in the
+Heisenberg model with magnetic dipole and exchange interactions by the spin
+operator diagram technique. Dispersion relations of spin waves in thin magnetic
+films (in two-dimensional magnetic monolayers and in two-layer magnetic films)
+and the spin-wave resonance spectrum in N-layer structures are found. For thick
+magnetic films generalized Landau-Lifshitz equations are derived from first
+principles. Landau-Lifshitz equations have the integral (pseudodifferential)
+form, but not differential one. Spin excitations are determined by simultaneous
+solution of the Landau-Lifshitz equations and the equation for the
+magnetostatic potential. For normal magnetized ferromagnetic films the spin
+wave damping has been calculated in the one-loop approximation for a diagram
+expansion of the Green functions at low temperature. In thick magnetic films
+the magnetic dipole interaction makes a major contribution to the relaxation of
+long-wavelength spin waves. Thin films have a region of low relaxation of
+long-wavelength spin waves. In thin magnetic films four-spin-wave processes
+take place and the exchange interaction makes a major contribution to the
+damping. It is found that the damping of spin waves propagating in magnetic
+monolayer is proportional to the quadratic dependence on the temperature and is
+very low for spin waves with small wavevectors. Spin-wave devices on the base
+of nanosized magnetic films are proposed -- tunable narrow-band spin-wave
+filters with high quality at the microwave frequency range and field-effect
+transistor (FET) structures contained nanosized magnetic films under the gate
+electrode. Spin-wave resonances in nanosized magnetic films can be used to
+construct FET structures operating in Gigahertz and Terahertz frequency bands.",1111.3532v1
+2011-11-30,Relation of Astrophysical Turbulence and Magnetic Reconnection,"Astrophysical fluids are generically turbulent and this must be taken into
+account for most transport processes. We discuss how the preexisting turbulence
+modifies magnetic reconnection and how magnetic reconnection affects the MHD
+turbulent cascade. We show the intrinsic interdependence and interrelation of
+magnetic turbulence and magnetic reconnection, in particular, that strong
+magnetic turbulence in 3D requires reconnection and 3D magnetic turbulence
+entails fast reconnection. We follow the approach in Eyink, Lazarian & Vishniac
+2011 to show that the expressions of fast magnetic reconnection in Lazarian &
+Vishniac 1999 can be recovered if Richardson diffusion of turbulent flows is
+used instead of ordinary Ohmic diffusion. This does not revive, however, the
+concept of magnetic turbulent diffusion which assumes that magnetic fields can
+be mixed up in a passive way down to a very small dissipation scales. On the
+contrary, we are dealing the reconnection of dynamically important magnetic
+field bundles which strongly resist bending and have well defined mean
+direction weakly perturbed by turbulence. We argue that in the presence of
+turbulence the very concept of flux-freezing requires modification. The
+diffusion that arises from magnetic turbulence can be called reconnection
+diffusion as it based on reconnection of magnetic field lines. The reconnection
+diffusion has important implications for the continuous transport processes in
+magnetized plasmas and for star formation. In addition, fast magnetic
+reconnection in turbulent media induces the First order Fermi acceleration of
+energetic particles, can explain solar flares and gamma ray bursts. However,
+the most dramatic consequence of these developments is the fact that the
+standard flux freezing concept must be radically modified in the presence of
+turbulence.",1112.0022v1
+2012-10-13,Full-disk nonlinear force-free field extrapolation of SDO/HMI and SOLIS/VSM magnetograms,"Extrapolation codes in Cartesian geometry for modelling the magnetic field in
+the corona do not take the curvature of the Sun's surface into account and can
+only be applied to relatively small areas, e.g., a single active region. We
+compare the analysis of the photospheric magnetic field and subsequent
+force-free modeling based on full-disk vector maps from Helioseismic and
+Magnetic Imager (HMI) on board solar dynamics observatory (SDO) and Vector
+Spectromagnetograph (VSM) of the Synoptic Optical Long-term Investigations of
+the Sun (SOLIS). We use Helioseismic and Magnetic Imager and Vector
+Spectromagnetograph photospheric magnetic field measurements to model the
+force-free coronal field above multiple solar active regions, assuming magnetic
+forces to dominate. We solve the nonlinear force-free field equations by
+minimizing a functional in spherical coordinates over a full disk excluding the
+poles. After searching for the optimum modeling parameters for the particular
+data sets, we compare the resulting nonlinear force-free model fields. We
+compare quantities like the total magnetic energy content and free magnetic
+energy, the longitudinal distribution of the magnetic pressure and surface
+electric current density using our spherical geometry extrapolation code. The
+magnetic field lines obtained from nonlinear force-free extrapolation based on
+Helioseismic and Magnetic Imager and Vector Spectromagnetograph data have good
+agreement. However, the nonlinear force-free extrapolation based on
+Helioseismic and Magnetic Imager data have more contents of total magnetic
+energy, free magnetic energy, the longitudinal distribution of the magnetic
+pressure and surface electric current density compared to the one from Vector
+Spectromagnetograph data.",1210.3668v1
+2012-12-04,Evolution of Primordial Magnetic Fields from Phase Transitions,"We consider the evolution of primordial magnetic fields generated during
+cosmological, electroweak or QCD, phase transitions. We assume that the
+magnetic field generation can be described as an injection of magnetic energy
+to cosmological plasma at a given scale determined by the moment of magnetic
+field generation. A high Reynolds number ensures strong coupling between
+magnetic field and fluid motions. The subsequent evolution of the magnetic
+field is governed by decaying hydromagnetic turbulence. Both our numerical
+simulations and a phenomenological description allow us to recover ""universal""
+laws for the decay of magnetic energy and the growth of magnetic correlation
+length in the turbulent (low viscosity) regime. In particular, we show that
+during the radiation dominated epoch, energy and correlation length of
+non-helical magnetic fields scale as conformal time to the powers -1/2 and
++1/2, respectively. For helical magnetic fields, energy and correlation length
+scale as conformal time to the powers -1/3 and +2/3, respectively. The
+universal decay law of the magnetic field implies that the strength of magnetic
+field generated during the QCD phase transition could reach $\sim 10^{-9}$\,G
+with the present day correlation length $\sim 50$ kpc. The fields generated at
+the electroweak phase transition could be as strong as $\sim 10^{-10}$ G with
+correlation lengths reaching $\sim 0.3$\,kpc. These values of the magnetic
+fields are consistent with the lower bounds of the extragalactic magnetic
+fields.",1212.0596v2
+2014-06-21,Quark stars under strong magnetic fields,"Within the confined isospin- and density-dependent mass model, we study the
+properties of strange quark matter (SQM) and quark stars (QSs) under strong
+magnetic fields. The equation of state of SQM under a constant magnetic field
+is obtained self-consistently and the pressure perpendicular to the magnetic
+field is shown to be larger than that parallel to the magnetic field, implying
+that the properties of magnetized QSs generally depend on both the strength and
+the orientation of the magnetic fields distributed inside the stars. Using a
+density-dependent magnetic field profile which is introduced to mimic the
+magnetic field strength distribution in a star, we study the properties of
+static spherical QSs by assuming two extreme cases for the magnetic field
+orientation in the stars, i.e., the radial orientation in which the local
+magnetic fields are along the radial direction and the transverse orientation
+in which the local magnetic fields are randomly oriented but perpendicular to
+the radial direction. Our results indicate that including the magnetic fields
+with radial (transverse) orientation can significantly decrease (increase) the
+maximum mass of QSs, demonstrating the importance of the magnetic field
+orientation inside the magnetized compact stars.",1406.5610v2
+2014-12-10,Joint inverse cascade of magnetic energy and magnetic helicity in MHD turbulence,"We show that oppositely directed fluxes of energy and magnetic helicity
+coexist in the inertial range in fully developed magnetohydrodynamic (MHD)
+turbulence with small-scale sources of magnetic helicity. Using a helical shell
+model of MHD turbulence, we study the high Reynolds number magnetohydrodynamic
+turbulence for helicity injection at a scale that is much smaller than the
+scale of energy injection. In a short range of scales larger than the forcing
+scale of magnetic helicity, a bottleneck-like effect appears, which results in
+a local reduction of the spectral slope. The slope changes in a domain with a
+high level of relative magnetic helicity, which determines that part of the
+magnetic energy related to the helical modes at a given scale. If the relative
+helicity approaches unity, the spectral slope tends to $-3/2$. We show that
+this energy pileup is caused by an inverse cascade of magnetic energy
+associated with the magnetic helicity. This negative energy flux is the
+contribution of the pure magnetic-to-magnetic energy transfer, which vanishes
+in the non-helical limit. In the context of astrophysical dynamos, our results
+indicate that a large-scale dynamo can be affected by the magnetic helicity
+generated at small scales. The kinetic helicity, in particular, is not involved
+in the process at all. An interesting finding is that an inverse cascade of
+magnetic energy can be provided by a small-scale source of magnetic helicity
+fluctuations without a mean injection of magnetic helicity.",1412.3225v1
+2015-04-29,The formation of regular interarm magnetic fields in spiral galaxies,"Observations of regular magnetic fields in several nearby galaxies reveal
+magnetic arms situated between the material arms. The nature of these magnetic
+arms is a topic of active debate. Previously we found a hint that taking into
+account the effects of injections of small-scale magnetic fields generated,
+e.g., by turbulent dynamo action, into the large-scale galactic dynamo can
+result in magnetic arm formation. We now investigate the joint roles of an
+arm/interarm turbulent diffusivity contrast and injections of small-scale
+magnetic field on the formation of large-scale magnetic field (""magnetic arms"")
+in the interarm region. We use the relatively simple ""no-$z$"" model for the
+galactic dynamo. This involves projection on to the galactic equatorial plane
+of the azimuthal and radial magnetic field components; the field component
+orthogonal to the galactic plane is estimated from the solenoidality condition.
+We find that addition of diffusivity gradients to the effect of magnetic field
+injections makes the magnetic arms much more pronounced. In particular, the
+regular magnetic field component becomes larger in the interarm space compared
+to that within the material arms.The joint action of the turbulent diffusivity
+contrast and small-scale magnetic field injections (with the possible
+participation of other effects previously suggested) appears to be a plausible
+explanation for the phenomenon of magnetic arms.",1504.07824v3
+2016-06-08,Simulation and experiments of Stacks of High Temperature Superconducting Coated Conductors Magnetized by Pulsed Field Magnetization with Multi-Pulse Technique,"High temperature superconducting (HTS) bulks or stacks of coated conductors
+(CCs) can be magnetized to become trapped field magnets (TFMs). The magnetic
+fields of such TFMs can break the limitation of conventional magnets (<2 T), so
+they show potential for improving the performance of many electrical
+applications that use permanent magnets like rotating machines. Towards
+practical or commercial use of TFMs, effective in situ magnetization is one of
+the key issues. The pulsed field magnetization (PFM) is among the most
+promising magnetization methods in virtue of its compactness, mobility and low
+cost. However, due to the heat generation during the magnetization, the trapped
+field and flux acquired by PFM usually cannot achieve the full potential of a
+sample (acquired by the field cooling or zero field cooling method). The
+multi-pulse technique was found to effectively improve the trapped field by PFM
+in practice. In this work, a systematic study on the PFM with successive pulses
+is presented. A 2D electromagnetic-thermal coupled model with comprehensive
+temperature dependent parameters is used to simulate a stack of CCs magnetized
+by successive magnetic pulses. An overall picture is built to show how the
+trapped field and flux evolve with different pulse sequences and the evolution
+patterns are analyzed. Based on the discussion, an operable magnetization
+strategy of PFM with successive pulses is suggested to provide more trapped
+field and flux. Finally, experimental results of a stack of CCs magnetized by
+typical pulse sequences are presented for demonstration.",1606.07732v1
+2017-08-25,Statistics of magnetic field measurements and evolution of magnetic field of OBA stars,"We review the measurements of magnetic fields of OBA stars. Based on these
+data we confirm that magnetic fields are distributed according to a lognormal
+law with a mean log(B)=-0.5 (B in kG) with a standard deviation sigma=0.5. The
+shape of the magnetic field distribution is similar to that for neutron stars.
+This finding is in favor of the hypothesis that the magnetic field of a neutron
+star is determined mainly by the magnetic field of its predecessor, the massive
+OB star. Further, we model the evolution of an ensemble of magnetic massive
+stars in the Galaxy. We use our own population synthesis code to obtain the
+distribution of stellar radii, ages, masses, temperatures, effective magnetic
+fields and magnetic fluxes from the pre-main sequence (PMS) via zero age main
+sequence (ZAMS) up to the terminal age main sequence (TAMS) stages. A
+comparison of the obtained in our model magnetic field distribution (MFD) with
+that obtained from the recent measurements of the stellar magnetic field allows
+us to conclude that the evolution of magnetic fields of massive stars is slow
+if not absent. The shape of the real MFD shows no indications of the magnetic
+desert proposed previously. Based on this finding we argue that the observed
+fraction of magnetic stars is determined by physical conditions at the PMS
+stage of stellar evolution.",1708.07816v2
+2017-08-22,A pico-Tesla magnetic sensor with PZT bimorph and permanent magnet proof mass,"Ferromagnetic-ferroelectric composites have attracted interests in recent
+years for use as magnetic field sensors. The sensing is based on
+magneto-electric (ME) coupling between the electric and magnetic subsystems and
+is mediated by mechanical strain. Such sensors for AC magnetic fields require a
+bias magnetic field to achieve pT-sensitivity. Here we discuss measurements and
+theory for a novel passive, AC magnetic sensor that does not require a bias
+magnetic field and is based on a PZT bimorph with a permanent magnet proof
+mass. Mechanical strain on the PZT bimorph in this case is produced by
+interaction between the applied AC magnetic field and remnant magnetization of
+the permanent magnet, resulting in an induced voltage across PZT. Our studies
+have been performed on sensors with a bimorph of oppositely poled PZT platelets
+and a NdFeB permanent magnet proof mass. Magnetic floor noise N on the order of
+100 pT per sqrHz and 10 nT per sqrHz are measured at 1 Hz and 10 Hz,
+respectively. When the AC magnetic field is applied at the bending resonance of
+40 Hz for the bimorph, the measured N 700 pT per sqrHz. We also discuss a
+theory for the magneto-electro-mechanical coupling at low frequency and bending
+resonance in the sensor and theoretical estimates of ME voltage coefficients
+are in very good agreement with the data.",1709.01794v1
+2017-12-13,Studying the transfer of magnetic helicity in solar active regions with the connectivity-based helicity flux density method,"In the solar corona, magnetic helicity slowly and continuously accumulates in
+response to plasma flows tangential to the photosphere and magnetic flux
+emergence through it. Analyzing this transfer of magnetic helicity is key for
+identifying its role in the dynamics of active regions (ARs). The
+connectivity-based helicity flux density method was recently developed for
+studying the 2D and 3D transfer of magnetic helicity in ARs. The method takes
+into account the 3D nature of magnetic helicity by explicitly using knowledge
+of the magnetic field connectivity, which allows it to faithfully track the
+photospheric flux of magnetic helicity. Because the magnetic field is not
+measured in the solar corona, modeled 3D solutions obtained from force-free
+magnetic field extrapolations must be used to derive the magnetic connectivity.
+Different extrapolation methods can lead to markedly different 3D magnetic
+field connectivities, thus questioning the reliability of the
+connectivity-based approach in observational applications. We address these
+concerns by applying this method to the isolated and internally complex AR
+11158 with different magnetic field extrapolation models. We show that the
+connectivity-based calculations are robust to different extrapolation methods,
+in particular with regards to identifying regions of opposite magnetic helicity
+flux. We conclude that the connectivity-based approach can be reliably used in
+observational analyses and is a promising tool for studying the transfer of
+magnetic helicity in ARs and relate it to their flaring activity.",1712.04691v1
+2018-05-09,The Effects of Magnetic Field Strength on Properties of Wind Generated from Hot Accretion Flow,"Observations indicate that wind can be generated in hot accretion flow. By
+performing numerical simulations, Yuan et al. studied the detailed properties
+of wind generated from weakly magnetized accretion flow. However, properties of
+wind generated from strongly magnetized hot accretion flow have not been
+studied. In this paper, we study the properties of wind generated from both
+weakly and strongly magnetized accretion flow. We focus on how the magnetic
+field strength affects the wind properties. We solve time-steady
+two-dimensional magnetohydrodynamic (MHD) equations of black hole accretion in
+the presence of large-scale magnetic field. We assume self-similarity in radial
+direction. The magnetic field is assumed to be evenly symmetric with the
+equatorial plane. We find that wind exists in both weakly and strongly
+magnetized accretion flow. When magnetic field is weak (magnetic pressure is
+more than 2 orders of magnitude smaller than gas pressure), wind is driven by
+gas pressure gradient and centrifugal forces. When magnetic field is strong
+(magnetic pressure is slightly smaller than gas pressure), wind is driven by
+gas pressure gradient and magnetic pressure gradient forces. The power of wind
+in strongly magnetized case is just slightly larger than that in weakly
+magnetized case. The power of wind lies in a range $ P_W \sim 10^{-4}-10^{-3}
+\dot M_{\rm in} c^2 $, with $ \dot M_{\rm in} $ and $ c $ being mass inflow
+rate and speed of light, respectively. The possible role of wind in active
+galactic nuclei feedback is briefly discussed.",1805.03378v1
+2018-08-08,Magnetic Gradiometer for Detection of Zero- and Ultralow-Field Nuclear Magnetic Resonance,"Magnetic sensors are important for detecting nuclear magnetization signals in
+nuclear magnetic resonance (NMR). As a complementary analysis tool to
+conventional high-field NMR, zero- and ultralow-field (ZULF) NMR detects
+nuclear magnetization signals in the sub-microtesla regime. Current ZULF NMR
+systems are always equipped with high-quality magnetic shieldings to ensure
+that ambient magnetic field noise does not dwarf the magnetization signal. An
+alternative approach is to separate the magnetization signal from the noise
+based on their differing spatial profiles, as can be achieved using a magnetic
+gradiometer. Here, we present a gradiometric ZULF NMR spectrometer with a
+magnetic gradient noise of 17 fT_{rms}{cm}^{-1}{Hz}^{-1/2} in the frequency
+range of 100-400 Hz, based on a single vapor cell (0.7x0.7x1.0{cm}^3). With
+applied white magnetic-field noise, we show that the gradiometric spectrometer
+achieves 13-fold enhancement in the signal-to-noise ratio (SNR) compared to the
+single-channel configuration. By reducing the influence of common-mode magnetic
+noise, this work enables the use of compact and low-cost magnetic shields.
+Gradiometric detection may also prove to be beneficial for eliminating
+systematic errors in ZULF-NMR experiments searching for exotic spin-dependent
+interactions and molecular parity violation.",1808.02743v1
+2019-01-30,Comparative Study of the Surface Potential of Magnetic and Non-magnetic Spherical Objects in a Magnetized RF Discharge Plasma,"We report measurements of the time-averaged surface floating potential of
+magnetic and non-magnetic spherical probes (or large dust particles) immersed
+in a magnetized capacitively coupled discharge. In this study, the size of the
+spherical probes is taken greater than the Debye length. The surface potential
+of a spherical probe first increases, i.e. becomes more negative at low
+magnetic field (B $<$ 0.05 T), attains a maximum value and decreases with
+further increase of the magnetic field strength (B $>$ 0.05 T). The rate of
+change of the surface potential in the presence of a B-field mainly depends on
+the background plasma and types of material of the objects. The results show
+that the surface potential of the magnetic sphere is higher (more negative)
+compared to the non-magnetic spherical probe. Hence, the smaller magnetic
+sphere collects more negative charges on its surface than a bigger non-magnetic
+sphere in a magnetized plasma. The different sized spherical probes have nearly
+the same surface potential above a threshold magnetic field (B $>$ 0.03 T),
+implicating a smaller role of size dependence on the surface potential of
+spherical objects. The variation of the surface potential of the spherical
+probes is understood on the basis of a modification of the collection currents
+to their surface due to charge confinement and cross-field diffusion in the
+presence of an external magnetic field.",1901.10955v4
+2019-02-27,Relative magnetic field line helicity,"Context. Magnetic helicity is an important quantity in studies of magnetized
+plasmas as it provides a measure of the geometrical complexity of the magnetic
+field in a given volume. A more detailed description of the spatial
+distribution of magnetic helicity is given by the field line helicity that
+expresses the amount of helicity associated to individual field lines, rather
+than in the full analysed volume. Aims. Magnetic helicity is not a
+gauge-invariant quantity in general, unless it is computed with respect to a
+reference field, yielding the so called relative magnetic helicity. The field
+line helicity corresponding to the relative magnetic helicity has only been
+examined under specific conditions so far. This work aims to define the field
+line helicity corresponding to relative magnetic helicity in the most general
+way. In addition to its general form, we provide the expression for the
+relative magnetic field line helicity in a few commonly used gauges, and
+reproduce known results as a limit of our general formulation. Methods. By
+starting from the definition of relative magnetic helicity, we derive the
+corresponding field line helicity, and we note the assumptions it is based on.
+Results. We check that the developed quantity reproduces relative magnetic
+helicity by using three different numerical simulations. For these cases we
+also show the morphology of field line helicity in the volume, and on the
+photospheric plane. As an application to solar situations, we compare the
+morphology of field line helicity on the photosphere with that of the
+connectivity-based helicity flux density in two reconstructions of an active
+region's magnetic field. We discuss how the derived relative magnetic field
+line helicity has a wide range of applications, notably in solar physics and
+magnetic reconnection studies.",1902.10410v1
+2019-09-05,"The Magnetic Early B-type Stars III: A main sequence magnetic, rotational, and magnetospheric biography","Magnetic confinement of stellar winds leads to the formation of
+magnetospheres, which can be sculpted into Centrifugal Magnetospheres (CMs) by
+rotational support of the corotating plasma. The conditions required for the
+CMs of magnetic early B-type stars to yield detectable emission in H$\alpha$ --
+the principal diagnostic of these structures -- are poorly constrained. A key
+reason is that no detailed study of the magnetic and rotational evolution of
+this population has yet been performed. Using newly determined rotational
+periods, modern magnetic measurements, and atmospheric parameters determined
+via spectroscopic modelling, we have derived fundamental parameters, dipolar
+oblique rotator models, and magnetospheric parameters for 56 early B-type
+stars. Comparison to magnetic A- and O-type stars shows that the range of
+surface magnetic field strength is essentially constant with stellar mass, but
+that the unsigned surface magnetic flux increases with mass. Both the surface
+magnetic dipole strength and the total magnetic flux decrease with stellar age,
+with the rate of flux decay apparently increasing with stellar mass. We find
+tentative evidence that multipolar magnetic fields may decay more rapidly than
+dipoles. Rotational periods increase with stellar age, as expected for a
+magnetic braking scenario. Without exception, all stars with H$\alpha$ emission
+originating in a CM are 1) rapid rotators, 2) strongly magnetic, and 3) young,
+with the latter property consistent with the observation that magnetic fields
+and rotation both decrease over time.",1909.02530v1
+2020-04-24,Observation of magnetic domain and bubble structures in magnetoelectric Sr$_3$Co$_2$Fe$_{24}$O$_{41}$,"The magnetic domain and bubble structures in the Z-type hexaferrite
+Sr$_3$Co$_2$Fe$_{24}$O$_{41}$ were investigated using Lorentz microscopy. This
+hexaferrite exhibits a room-temperature magnetoelectric effect that is
+attributed to its transverse conical spin structure (TC phase). Upon heating,
+the TC phase transforms into a ferrimagnetic phase with magnetic moments in the
+hexagonal $ab$ plane between 410 and 480 K (FM2 phase) and into another
+ferrimagnetic phase with moments parallel to the $c$ axis between 490 and 680 K
+(FM1 phase). Accordingly, in this study, the magnetic domain structures in
+Sr$_3$Co$_2$Fe$_{24}$O$_{41}$ were observed to change dramatically with
+temperature. In the TC phase, irregular fine magnetic domains were observed
+after cooling the specimen from the FM2 to TC phase. In the FM1 phase, striped
+magnetic domain walls with pairs of bright and dark contrast were formed
+parallel to the $c$ axis. Upon applying an external magnetic field, the striped
+magnetic domain walls transformed into magnetic bubbles. The topology of the
+magnetic bubbles was dependent on the angle between the external magnetic field
+($H$) direction and the easy $c$ axis. Namely, magnetic bubbles with the
+topological number $N$ = 1 (type I) were created for $H//c$, whereas magnetic
+bubbles with $N$ = 0 (type II) were created when the magnetic field was tilted
+from the c axis by 5{\deg}. We attribute the high magnetocrystalline anisotropy
+of Sr$_3$Co$_2$Fe$_{24}$O$_{41}$ to the emergence of magnetic bubbles in the
+FM1 phase.",2004.11591v1
+2020-06-12,Odd-even layer-number effect and layer-dependent magnetic phase diagrams in MnBi2Te4,"The intrinsic magnetic layered topological insulator MnBi2Te4 with nontrivial
+topological properties and magnetic order has become a promising system for
+exploring exotic quantum phenomena such as quantum anomalous Hall effect.
+However, the layer-dependent magnetism of MnBi2Te4, which is fundamental and
+crucial for further exploration of quantum phenomena in this system, remains
+elusive. Here, we use polar reflective magnetic circular dichroism
+spectroscopy, combined with theoretical calculations, to obtain an in-depth
+understanding of the layer-dependent magnetic properties in MnBi2Te4. The
+magnetic behavior of MnBi2Te4 exhibits evident odd-even layer-number effect,
+i.e. the oscillations of the coercivity of the hysteresis loop (at {\mu}0Hc)
+and the spin-flop transition (at {\mu}0H1), concerning the Zeeman energy and
+magnetic anisotropy energy. In the even-number septuple layers, an anomalous
+magnetic hysteresis loop is observed, which is attributed to the
+thickness-independent surface-related magnetization. Through the linear-chain
+model, we can clarify the odd-even effect of the spin-flop field and determine
+the evolution of magnetic states under the external magnetic field. The
+mean-field method also allows us to trace the experimentally observed magnetic
+phase diagrams to the magnetic fields, layer numbers and especially,
+temperature. Overall, by harnessing the unusual layer-dependent magnetic
+properties, our work paves the way for further study of quantum properties of
+MnBi2Te4.",2006.07216v1
+2021-05-31,Theoretical development in the viscosity of ferrofluid,"The viscosity of ferrofluid has an important role in liquid sealing of the
+hard disk drives, biomedical applications as drug delivery, hyperthermia, and
+magnetic resonance imaging. In the absence of a magnetic field, the viscosity
+of ferrofluid depends on the volume concentration of magnetic nanoparticles
+including surfactant layers. However, under the influence of a stationary
+magnetic field, the viscosity of ferrofluid depends on the angle between the
+applied magnetic field and vorticity in the flow. If this angle is 90o, then
+there is a maximum increase in the viscosity. If the magnetic field and the
+vorticity in the flow are parallel to each other, then there is no change in
+the viscosity since the applied magnetic field does not change the speed of the
+rotation of magnetic nanoparticles in the fluid. The viscosity of ferrofluid in
+the presence of an alternating magnetic field demonstrates interesting
+behavior. When field frequency matches with the relaxation time, known as
+resonance condition, then there is no impact of an alternating magnetic field
+in the viscosity of ferrofluid. If the frequency of an alternating magnetic
+field is less than resonance frequency, then an alternating magnetic field
+increases the viscosity of ferrofluid. Using higher frequency than resonance
+condition reduces the viscosity of ferrofluid and researchers reported this
+incident as the negative viscosity effect. If the frequency of an alternating
+magnetic field tends to infinite, then ferrofluid ceases to feel a magnetic
+field. In this case, there is no impact of an alternating magnetic field on the
+viscosity of ferrofluid.",2105.14721v1
+2021-08-19,Quantized edge magnetizations and their symmetry protection in one-dimensional quantum spin systems,"The bulk electric polarization works as a nonlocal order parameter that
+characterizes topological quantum matters. Motivated by a recent paper [H.
+Watanabe \textit{et al.}, Phys. Rev. B {\bf 103}, 134430 (2021)], we discuss
+magnetic analogs of the bulk polarization in one-dimensional quantum spin
+systems, that is, quantized magnetizations on the edges of one-dimensional
+quantum spin systems.The edge magnetization shares the topological origin with
+the fractional edge state of the topological odd-spin Haldane phases. Despite
+this topological origin, the edge magnetization can also appear in
+topologically trivial quantum phases. We develop straightforward field
+theoretical arguments that explain the characteristic properties of the edge
+magnetization. The field theory shows that a U(1) spin-rotation symmetry and a
+site-centered or bond-centered inversion symmetry protect the quantization of
+the edge magnetization. We proceed to discussions that quantum phases on
+nonzero magnetization plateaus can also have the quantized edge magnetization
+that deviates from the magnetization density in bulk. We demonstrate that the
+quantized edge magnetization distinguishes two quantum phases on a
+magnetization plateau separated by a quantum critical point. The edge
+magnetization exhibits an abrupt stepwise change from zero to $1/2$ at the
+quantum critical point because the quantum phase transition occurs in the
+presence of the symmetries protecting the quantization of the edge
+magnetization. We also show that the quantized edge magnetization can result
+from the spontaneous ferrimagnetic order.",2108.08458v2
+2021-08-27,Effects of anisotropy on strongly magnetized neutron and strange quark stars in general relativity,"We investigate the properties of anisotropic, spherically symmetric compact
+stars, especially neutron stars and strange quark stars, made of strongly
+magnetized matter. The neutron stars are described by SLy equation of state,
+the strange quark stars by an equation of state based on the MIT Bag model. The
+stellar models are based on an a priori assumed density dependence of the
+magnetic field and thus anisotropy. Our study shows that not only the presence
+of a strong magnetic field and anisotropy, but also the orientation of the
+magnetic field itself, have an important influence on the physical properties
+of stars. Two possible magnetic field orientations are considered, a radial
+orientation, where the local magnetic fields point in the radial direction, and
+a transverse orientation, where the local magnetic fields are perpendicular to
+the radial direction. Interestingly, we find that for a transverse orientation
+of the magnetic field, the stars become more massive with increasing anisotropy
+and magnetic field strength and increase in size, since the repulsive,
+effective anisotropic force increases in this case. In the case of a radially
+orientated magnetic field, however, the masses and radii of the stars decrease
+with increasing magnetic field strength, because of the decreasing effective
+anisotropic force. Importantly, we also show that in order to achieve
+hydrostatic equilibrium configurations of magnetized matter, it is essential to
+account for both the local anisotropy effects as well as the anisotropy effects
+caused by a strong magnetic field. Otherwise, hydrostatic equilibrium is not
+achieved for magnetized stellar models.",2108.12436v1
+2021-11-03,Anisotropic magnetocaloric effect of CrI$_{3}$: A theoretical study,"CrI$_{3}$ is considered to be a promising candidate for spintronic devices
+and data storage. We derived the Heisenberg Hamiltonian for CrI$_{3}$ from
+density functional calculations using the Liechtenstein formula. Moreover, the
+Monte--Carlo simulations with the Sucksmith--Thompson method were performed to
+analyze the effect of magnetic anisotropy energy on the thermodynamic
+properties. Our method successfully reproduced the negative sign of isothermal
+magnetic entropy changes when a magnetic field was applied along the hard
+plane. We found that the temperature dependence of the magnetocrystalline
+anisotropy energy is not negligible at temperatures slightly above the Curie
+temperature. We clarified that the origin of this phenomenon is attributed to
+anisotropic magnetic susceptibility and magnetization anisotropy. The
+difference between the entropy change of the easy axis and the hard plane is
+proportional to the temperature dependence of the magnetic anisotropy energy,
+implying that the anisotropic entropy term is the main source of the
+temperature dependence of the free energy difference when magnetizing in a
+specific direction other than the easy axis. We also investigated the magnetic
+susceptibility that can be used for the characterization of the negative sign
+of the entropy change in the case of a hard plane. The competition of
+magnetocrystalline anisotropy energy and external magnetic field at low
+temperature and low magnetic field region causes a high magnetic susceptibility
+as the fluctuation of magnetization. Meanwhile, the anisotropy energy is
+suppressed at a sufficient magnetic field applied along the hard axis, the
+magnetization is fully rotated to the direction of the external magnetic field.",2111.02063v1
+2023-01-22,FCC structured ferromagnetic ultra-thin films with two spin layers described by fourth order perturbed Heisenberg Hamiltonian,"Fourth order perturbation was applied to study a small variation of the
+azimuthal angle of spin of fcc structured ferromagnetic thin films with two
+spin layers. The variation of magnetic energy and the orientation of magnetic
+easy axis with the fourth order magnetic anisotropy constant in two spin layers
+was investigated. When the second order magnetic anisotropy constant at the top
+spin layer is higher than that of bottom spin layer, the total magnetic energy
+is slightly higher. Some spikes appeared in the 2D plot of of magnetic energy
+versus azimuthal angle of spin. According to the 3D plots, the peak value of
+the magnetic energy gradually decreases with the increase of the stress induced
+anisotropy constant, and thereafter the peak value of the magnetic energy
+gradually increases with the increase of the stress induced anisotropy
+constant. The angle between magnetic easy and hard directions was not 90
+degrees. The magnetic easy and hard directions of the film with a higher second
+order magnetic anisotropy constant of top layer are different from the magnetic
+easy and hard directions of the film with a lower second order magnetic
+anisotropy constant of top layer. When the second order magnetic anisotropy
+constant of the bottom layer is increased, the total magnetic energy does not
+change.",2301.09137v1
+2005-01-25,Magnetic Fields in Diffuse H I and Molecular Clouds,"This book chapter reviews the current state of observations of magnetic
+fields in diffuse H I and in dense molecular clouds. It covers techniques for
+measuring magnetic fields, the analysis of the observations, and the role of
+magnetic fields in the physics of interstellar clouds and in the star formation
+process.",0501550v1
+1998-10-25,Orbital Magnetism in Disordered Mesoscopic Metals,"The theory of orbital magnetism in disordered metals is reviewed, and
+extended to include a broad range of temperatures and fields. Sample-to-sample
+fluctuations in the orbital magnetic susceptibility are studied. In a given
+sample these fluctuations manifest themselves in aperiodic sample-specific
+oscillations of susceptibility and magnetization, when the strength of the
+magnetic field is changed.",9810330v1
+2000-09-07,"Intermediate spin, Schrödinger cat states and nano-magnets","Quantum tunneling of nano-magnets finds a natural description in terms of
+intermediate spin. Periodic magnetic effects correspond to a change of flux by
+the flux quantum $\Phi_{0}$. Schr\""odinger cat states with different
+superpositions of the applied magnetic field occur. The molecular magnet
+Fe$_{8}$ is discussed and oscillations are predicted for Mn$_{12}$.",0009100v1
+2002-01-14,Polaron percolation in diluted magnetic semiconductors,"We theoretically study the development of spontaneous magnetization in
+diluted magnetic semiconductors as arising from a percolation of bound magnetic
+polarons. Within the framework of a generalized percolation theory we derive
+analytic expressions for the Curie temperature and the magnetization, obtaining
+excellent quantitative agreement with Monte Carlo simulation results and good
+qualitative agreement with experimental results.",0201229v1
+2003-07-11,Magnetic and transport percolation in diluted magnetic semiconductors,"The ferromagnetic transition in a diluted magnetic semiconductor with
+localized charge carriers is inevitably a percolation transition. In this work
+we theoretically study the correlation between this magnetic percolation and
+transport properties of the sample, including the possibility of a simultaneous
+transport percolation. We find nontrivial signatures of the percolating
+magnetic clusters in the transport properties of the system, including
+interesting non-monotonic temperature dependence of the system resistivity.",0307294v1
+2003-09-05,Reduction of Magnetic Noise in Magnetic Resonance Force Microscopy,"We study the opportunity to reduce a magnetic noise produced by a uniform
+cantilever with a ferromagnetic particle in magnetic resonance force microscopy
+(MRFM) applications. We demonstrate theoretically a significant reduction of
+magnetic noise and the corresponding increase of the MRFM relaxation time using
+a nonuniform cantilever.",0309158v1
+2003-09-24,Non conservation of the magnetization current across magnetic hetero-structures,"We show that when the magnetizations on opposite sides of a junction are not
+collinear, the magnetization current is not conserved as the junction is
+crossed. Thus the usual treatment of this problem needs to be modified. We
+argue that this is due to an implicit assumption of an external torque that is
+required to clamp the magnetization in place. The physical consequence of this
+is explored.",0309555v1
+2005-11-21,Magnetization reversal in the anisotropy-dominated regime using time-dependent magnetic fields,"We study magnetization reversal using various r.f. magnetic pulses. We show
+numerically that switching is possible with simple sinusoidal pulses; however
+the optimum approach is to use a frequency-swept (chirped) r.f. magnetic pulse,
+the shape of which can be derived analytically. Switching times of the order of
+nanoseconds can be achieved with relatively small r.f. fields, independent of
+the anisotropy's strength.",0511497v1
+2004-01-08,Coordinate noncommutativity in strong non-uniform magnetic fields,"Noncommuting spatial coordinates are studied in the context of a charged
+particle moving in a strong non-uniform magnetic field. We derive a relation
+involving the commutators of the coordinates, which generalizes the one
+realized in a strong constant magnetic field. As an application, we discuss the
+noncommutativity in the magnetic field present in a magnetic mirror.",0401048v2
+2007-11-07,Magnetic properties of bi-phase micro- and nanotubes,"The magnetic configurations of bi-phase micro- and nanotubes consisting of a
+ferromagnetic internal tube, an intermediate non-magnetic spacer, and an
+external magnetic shell are investigated as a function of their geometry. Based
+on a continuum approach we obtained analytical expressions for the energy which
+lead us to obtain phase diagrams giving the relative stability of
+characteristic internal magnetic configurations of the bi-phase tubes.",0711.1101v1
+2008-06-16,"The fraction of Bose-Einstein condensed triplons in TlCuCl3 from magnetization M(T,H)-data","In this study we calculate the fraction of condensed magnetic quasiparticles
+of TlCuCl3 from magnetization M(T,H)-data. It is independent of the direction
+of the magnetic field and slightly decreases with increasing magnetic field.",0806.2519v1
+2009-03-03,Remarks on eigenvalue estimates and semigroup domination,"We present an overview over recent results concerning semi-classical spectral
+estimates for magnetic Schroedinger operators. We discuss how the constants in
+magnetic and non-magnetic eigenvalue bounds are related and we prove, in an
+abstract setting, that any non-magnetic Lieb-Thirring-type inequality implies a
+magnetic Lieb-Thirring-type inequality with possibly a larger constant.",0903.0561v1
+2009-10-21,A Generalized Approach to Determination of Magnetic Shielding Factor for Physics Package of Rb Atomic Clock,"In this paper we report generalized approach to calculate magnetic shielding
+factor (MSF) of multi-layer mu metal concentric cylindrical shields for
+arbitrary length to radius ratios and different values of magnetic
+permeability. We report in this paper the generalized results on the magnetic
+shielding factor of multi-layered magnetic shields used in Rb atomic clocks",0910.4031v1
+2009-12-01,"Control of magnetic vortex wall chirality, polarity and position by a magnetic field","The seeding of vortex domain walls in V-shaped nanowires by a magnetic field
+has been investigated via simulations and Scanning Electron Microscopy with
+Polarization Analysis (SEMPA). It is found that the orientation of the magnetic
+field can be used to purposely tune the chirality, polarity and position of
+single vortex domain walls in soft magnetic nanowires.",0912.0178v1
+2010-01-19,Theory of the Anomalous Magnetic Moment of the Electron,"It is shown that it follows from our model of the electron that its magnetic
+moment has an anomalous part if the magnetic field energy is taken into
+account. That means that the magnetic moment of our model of the electron is
+1.0000565 times larger than the measured magnetic moment of the electron.",1001.3371v2
+2010-10-18,Induced plasma magnetization due to magnetic monopoles,"When magnetic monopoles are introduced in plasma equations, the propagation
+of electromagnetic waves is modified. In this work is shown that this
+modification leads to the emergence of a ponderomotive force which induces a
+magnetization of the plasma. As a result, a cyclotron frequency is induced in
+electrons. This frequency is proportional to the square of the magnetic charge.",1010.3462v1
+2011-07-11,Electrical conductivity of quark matter in magnetic field,"Fermion currents in dense quark matter embedded into magnetic field are under
+intense discussions motivated by Chiral Magnetic Effect. We argue that
+conductivity of quark matter may be independent of the magnetic field direction
+and not proportional to the magnetic field strength.",1107.1990v3
+2011-10-05,Quadratic helicities and the energy of magnetic fields,"Two non-local asymptotic invariants of magnetic fields for the ideal
+magnetohydrodynamics are introduced. The velocity of variation of the
+invariants for a non-ideal magnetohydrodynamics with a small magnetic
+dissipation is estimated. By means of the invariants the spectra of
+electromagnetic fields are investigated. A possible role of higher magnetic
+helicities during a relaxation of magnetic fields is discussed.",1110.0997v1
+2012-01-04,Magnetic dipole moment of a moving electric dipole,"The current density of a moving electric dipole is expressed as the sum of
+polarization and magnetization currents. The magnetic field due to the latter
+current is that of a magnetic dipole moment that is consistent with the
+relativistic transformations of the polarization and magnetization of
+macroscopic electrodynamics.",1201.0938v2
+2012-02-12,Entropy Maximization and Instability of Uniformly Magnetized Plasma,"A regime where a uniformly magnetized plasma could be unstable to a spatial
+perturbation in the magnetic field is explored. In this regime, a uniformly
+magnetized state does not maximize the entropy. The physical implication is
+discussed in the context of the current generation, the magnetic reconnection,
+and the dynamo effect.",1202.2583v2
+2012-03-26,Thermo-magneto coupling in a dipole plasma,"On a dipole plasma, we observe the generation of magnetic moment, as the
+movement of the levitating magnet-plasma compound, in response to
+electron-cyclotron heating and the increase of $\beta$ (magnetically-confined
+thermal energy). We formulate a thermodynamic model with interpreting heating
+as injection of microscopic magnetic moment; the corresponding chemical
+potential is the ambient magnetic field.",1203.5680v1
+2012-10-29,Phase deformed magnetic Berezin transforms on $\mathbb{C}^{n}$: A formula representing phase deformed magnetic Berezin transforms as functions of the magnetic Laplacian on $\mathbb{C}^{n}$,"We introduce a new class of a phase deformed magnetic berezin transforms and
+we give two formulae representing these transforms as a functions of the
+magnetic laplacian on $\mathbb{C}^{n}.$ As a consequence, we give an inequality
+of diamagnetic type.",1210.7734v1
+2012-12-20,Magnetic properties of the RbNd(WO4)2 single crystal,"The magnetic investigations as a function of temperature and magnetic field
+for the rubidium neodymium double tungstate RbNd(WO4)2 single crystal have been
+performed. The magnetization was measured in the temperature range from 4.2 to
+100 K and for the magnetic field up to 1.5 T. The crystal field and exchange
+parameters were found.",1212.4997v1
+2014-06-14,Computer Simulations on Barkhausen effects and Magnetizations in Fe Nano-Structure Systems,"The magnetization processes in Fe nano-systems are investigated using the
+numerical simulations based on classical magnetic dipole moment interactions.
+The domain energies are calculated from moment-moment interactions over whole
+systems using large scale computing resources. The results directly show most
+of basic magnetization phenomena. The Barkhausen effects are represented with
+jumps and terraces of magnetization steps induced from external field changes
+of {\Delta}H.",1406.3688v1
+2015-01-28,Experimental Characterization of Magnetic Materials for the Magnetic Shielding of Cryomodules in Particle Accelerators,"The magnetic properties of two important passive magnetic shielding materials
+(A4K and Amumetal) for accelerator applications, subjected to various
+processing and heat treatment conditions are studied comprehensively over a
+wide range of temperatures: from Cryogenic to room temperature. We analyze the
+effect of processing on the extent of degradation of the magnetic properties of
+both materials and investigate the possibility of restoring these properties by
+re-annealing.",1501.07312v1
+2015-08-11,Transport between metals and magnetic insulators,"We derive the Onsager response matrix of fluctuation-mediated spin-collinear
+transport through a ferromagnetic insulator and normal metal interface driven
+by a temperature difference, spin accumulation, or magnetic field. We predict
+magnon-squeezing spin currents, magnetic field-induced cooling (magnon Peltier
+effect), temperature induced magnetization (thermal magnetic field) as well as
+universal spin Seebeck/Peltier coefficients.",1508.02486v2
+2019-01-17,Observations of solar small-scale magnetic flux-sheet emergence,"Aims. Moreno-Insertis et al. (2018) recently discovered two types of flux
+emergence in their numerical simulations: magnetic loops and magnetic sheet
+emergence. Whereas magnetic loop emergence has been documented well in the last
+years, by utilising high-resolution full Stokes data from ground-based
+telescopes as well as satellites, magnetic sheet emergence is still an
+understudied process. We report here on the first clear observational evidence
+of a magnetic sheet emergence and characterise its development.
+  Methods. Full Stokes spectra from the Hinode spectropolarimeter were inverted
+with the SIR code to obtain solar atmospheric parameters such as temperature,
+line-of-sight velocities and full magnetic field vector information.
+  Results. We analyse a magnetic flux emergence event observed in the quiet-sun
+internetwork. After a large scale appearance of linear polarisation, a magnetic
+sheet with horizontal magnetic flux density of up to 194 Mx/cm$^{2}$ hovers in
+the low photosphere spanning a region of 2 to 3 arcsec. The magnetic field
+azimuth obtained through Stokes inversions clearly shows an organised structure
+of transversal magnetic flux density emerging. The granule below the magnetic
+flux-sheet tears the structure apart leaving the emerged flux to form several
+magnetic loops at the edges of the granule.
+  Conclusions. A large amount of flux with strong horizontal magnetic fields
+surfaces through the interplay of buried magnetic flux and convective motions.
+The magnetic flux emerges within 10 minutes and we find a longitudinal magnetic
+flux at the foot points of the order of $\sim$$10^{18}$ Mx. This is one to two
+orders of magnitude larger than what has been reported for small-scale magnetic
+loops. The convective flows feed the newly emerged flux into the pre-existing
+magnetic population on a granular scale.",1901.05870v1
+2019-02-06,Iron oxide nanoparticles for magnetic hyperthermia,"Assemblies of magnetic nanoparticles show a great potential for application
+in biomedicine, in particular, in magnetic hyperthermia. However, to achieve
+desired therapeutic effect in magnetic hyperthermia the assembly of
+nanoparticles should have a sufficiently high specific absorption rate in
+alternating magnetic field of moderate amplitude and frequency.",1902.02220v1
+2021-02-26,Magnetic Curves in $C$-manifolds,"In this paper, we study normal magnetic curves in $C$-manifolds. We prove
+that magnetic trajectories with respect to the contact magnetic fields are
+indeed $\theta_{\alpha }$-slant curves with certain curvature functions. Then,
+we give the parametrizations of normal magnetic curves in $\mathbb{R}^{2n+s}$
+with its structures as a $C$-manifold.",2102.13623v1
+2021-04-14,Non-resonant circles for strong magnetic fields on surfaces,"We study non-resonant circles for strong magnetic fields on a closed,
+connected, oriented surface and show how these can be used to prove the
+existence of trapping regions and of periodic magnetic geodesics with
+prescribed low speed. As a corollary, there exist infinitely many periodic
+magnetic geodesics for every low speed in the following cases: i) the surface
+is not the two-sphere, ii) the magnetic field vanishes somewhere.",2104.06733v1
+2022-01-19,Using the Standard Linear Ramps of the CMS Superconducting Magnet for Measuring the Magnetic Flux Density in the Steel Flux Return Yoke,"The principal difficulty in large magnetic systems having an extensive flux
+return yoke is to characterize the magnetic flux distribution in the yoke steel
+blocks. Continuous measurements of the magnetic flux density in the return yoke
+are not possible and the usual practice uses software modelling of the magnetic
+system with special 3D computer programs. The flux return yoke of the Compact
+Muon Solenoid (CMS) magnet encloses a 3.8 T superconducting solenoid with a
+6-m-diameter by 12.5-m-length free bore and consists of five dodecagonal
+three-layered barrel wheels around the coil and four endcap disks at each end.
+The yoke steel blocks serve as the absorber plates of the muon detection
+system. A TOSCA 3D model of the CMS magnet has been developed to describe the
+magnetic field outside of the solenoid volume, which was measured with a
+field-mapping machine. To verify the magnetic flux distribution calculated in
+the yoke steel blocks, direct measurements of the magnetic flux density with 22
+flux loops installed in selected regions of the yoke were performed during the
+CMS magnet test in 2006 when four ""fast"" discharges of the CMS coil were
+triggered manually to test the magnet protection system. No fast discharge of
+the CMS magnet from its operational current of 18.2 kA, which corresponds to a
+central magnetic flux density of 3.8 T, has been performed that time. For the
+first time, in this paper we present measurements of the magnetic flux density
+in the steel blocks of the return yoke based on the several standard linear
+discharges of the CMS magnet from the operational magnet current of 18.2 kA. To
+provide these measurements, the voltages induced in the flux loops have been
+measured with six 16-bit DAQ modules and integrated offline over time. The
+results of the measurements during magnet linear ramps performed with a current
+rate as low as 1-1.5 A/s are presented and discussed.",2201.07557v1
+2022-11-15,Eigenvalue estimates for the magnetic Hodge Laplacian on differential forms,"In this paper we introduce the magnetic Hodge Laplacian, which is a
+generalization of the magnetic Laplacian on functions to differential forms. We
+consider various spectral results, which are known for the magnetic Laplacian
+on functions or for the Hodge Laplacian on differential forms, and discuss
+similarities and differences of this new ``magnetic-type'' operator.",2211.08019v1
+2024-03-04,Development of a Static Magnetic Diode,"This report experimentally demonstrates the feasibility of applying an
+electrical current though a stationary graphene structure to induce magnetic
+non-reciprocity or, in other words, to create a static magnetic diode, and
+thereby validate the suggestion of Prat-Camps [1] et al. regarding the use of
+graphene for such a purpose. The described graphene-based static magnetic diode
+is assessed against the rotating copper magnetic diode of Prat-Camps and found
+to be comparable.",2403.02193v1
+1997-08-03,A Vorticity-Magnetic Field Dynamo Instability,"We generalize the mean field magnetic dynamo to include local evolution of
+the mean vorticity in addition to the mean magnetic field. The coupled
+equations exhibit a general mean field dynamo instability that enables the
+transfer of turbulent energy to the magnetic field and vorticity on larger
+scales. The growth of the vorticity and magnetic field both require helical
+turbulence which can be supplied by an underlying global rotation. The dynamo
+coefficients are derived including the backreaction from the mean magnetic
+field to lowest order. We find that a mean vorticity field can actually seed
+exponential growth of mean magnetic field from only a small scale seed magnetic
+field, without the need for a seed mean magnetic field. The equations decouple
+when the fluctuating velocity and magnetic field cross-correlations vanish,
+resulting in the separate mean field magnetic and mean field vorticity dynamo
+equations.",9708019v1
+2002-05-18,Magnetic Helicity Tensor for an Anisotropic Turbulence,"The evolution of the magnetic helicity tensor for a nonzero mean magnetic
+field and for large magnetic Reynolds numbers in an anisotropic turbulence is
+studied. It is shown that the isotropic and anisotropic parts of the magnetic
+helicity tensor have different characteristic times of evolution. The time of
+variation of the isotropic part of the magnetic helicity tensor is much larger
+than the correlation time of the turbulent velocity field. The anisotropic part
+of the magnetic helicity tensor changes for the correlation time of the
+turbulent velocity field. The mean turbulent flux of the magnetic helicity is
+calculated as well. It is shown that even a small anisotropy of turbulence
+strongly modifies the flux of the magnetic helicity. It is demonstrated that
+the tensor of the magnetic part of the alpha-effect for weakly inhomogeneous
+turbulence is determined only by the isotropic part of the magnetic helicity
+tensor. Astrophysical applications of the obtained results are discussed.",0205314v1
+2006-09-22,Buoyant magnetic flux ropes in a magnetized stellar envelope: Idealized numerical 2.5-D MHD simulations,"Context: The context of this paper is buoyant toroidal magnetic flux ropes,
+which is a part of flux tube dynamo theory and the framework of solar-like
+magnetic activity. Aims: The aim is to investigate how twisted magnetic flux
+ropes interact with a simple magnetized stellar model envelope--a magnetic
+""convection zone""--especially to examine how the twisted magnetic field
+component of a flux rope interacts with a poloidal magnetic field in the
+convection zone. Method: Both the flux ropes and the atmosphere are modelled as
+idealized 2.5-dimensional concepts using high resolution numerical
+magneto-hydrodynamic (MHD) simulations. Results: It is illustrated that twisted
+toroidal magnetic flux ropes can interact with a poloidal magnetic field in the
+atmosphere to cause a change in both the buoyant rise dynamics and the flux
+rope's geometrical shape. The details of these changes depend primarily on the
+polarity and strength of the atmospheric field relative to the field strength
+of the flux rope. It is suggested that the effects could be verified
+observationally.",0609630v1
+2000-07-03,Interaction of Mesoscopic Magnetic Textures with Superconductors,"We analyze magnetic textures in a thin magnetic film and screening currents
+induced by these textures in a superconducting film. The films are supposed to
+be parallel and close to each other, but interact only via magnetic fields. We
+consider also vortices inside superconducting film and their interaction with
+magnetic textures. As examples of magnetic textures we consider magnetic dot
+and magnetic vortex. We derive the condition at which spontaneous formation of
+a vortex or a coupled vortex-magnetic defect is energetically favorable. It is
+proven that the normal component of magnetic field generated by a magnetic dot
+changes sign in the presence of the superconducting vortex.",0007016v1
+2002-04-29,Electron Magnetic Resonance: The Modified Bloch Equation,"We find a modified Bloch equation for the electronic magnetic moment when the
+magnetic moment explicitly contains a diamagnetic contribution (a magnetic
+field induced magnetic moment arising from the electronic orbital angular
+momentum) in addition to the intrinsic magnetic moment of the electron. The
+modified Bloch is coupled to equations of motion for the position and momentum
+operators. In the presence of static and time varying magnetic field
+components, the magnetic moment oscillates out of phase with the magnetic field
+and power is absorbed by virtue of the magnetic field induced magnetic moment,
+even in the absence of coupling to the environment. We explicitly work out the
+spectrum and absorption for the case of a $p$ state electron.",0204604v1
+2002-11-21,Magnetic levitation force between a superconducting bulk magnet and a permanent magnet,"The current density in a disk-shaped superconducting bulk magnet and the
+magnetic levitation force exerted on the superconducting bulk magnet by a
+cylindrical permanent magnet are calculated from first principles. The effect
+of the superconducting parameters of the superconducting bulk is taken into
+account by assuming the voltage-current law and the material law. The magnetic
+levitation force is dominated by the remnant current density, which is induced
+by switching off the applied magnetizing field. High critical current density
+and flux creep exponent may increase the magnetic levitation force. Large
+volume and high aspect ratio of the superconducting bulk can enhance the
+magnetic levitation force further.",0211470v1
+2003-06-23,Magnetic-field and current-density distributions in thin-film superconducting rings and disks,"We show how to calculate the magnetic-field and sheet-current distributions
+for a thin-film superconducting annular ring (inner radius a, outer radius b,
+and thickness d<<a) when either the penetration depth obeys lambda < d/2 or, if
+lambda > d/2, the two-dimensional screening length obeys Lambda = 2 lambda^2/d
+<< a for the following cases: (a) magnetic flux trapped in the hole in the
+absence of an applied magnetic field, (b) zero magnetic flux in the hole when
+the ring is subjected to an applied magnetic field, and (c) focusing of
+magnetic flux into the hole when a magnetic field is applied but no net current
+flows around the ring. We use a similar method to calculate the magnetic-field
+and sheet-current distributions and magnetization loops for a thin,
+bulk-pinning-free superconducting disk (radius b) containing a dome of magnetic
+flux of radius a when flux entry is impeded by a geometrical barrier.",0306585v1
+2006-08-08,Anomalous Hall Resistivity of TbBaCo2O5.53 with Non-trivial Magnetic Structure,"To investigate the Hall resistivity rH of systems with non-trivial spin
+structures, transport and magnetic properties of the oxygen deficient
+perovskite system TbBaCo2O5.53 with non-trivial magnetic structures have been
+adopted. As has been already known, the system exhibits, with decreasing
+temperature T, a transition to a ferromagnetic (FM) phase with non-collinear
+magnetic structure at TC 280 K in zero magnetic field and with further
+decreasing T, the spontaneous magnetization begins to decrease at T1~260 K and
+becomes zero at TN 245 K, where an antiferromagnetic (AFM) phase with
+non-collinear magnetic structure is realized. The metamagnetic behavior is
+induced by the relatively small magnetic field H (< 5 T) in the T region
+between ~200 K and T1. In this T region, unusual H dependence of rH has been
+observed. By analyzing the observed rH and magnetization M, the H dependence of
+the anomalous Hall coefficients Rs has been obtained at various fixed
+temperatures. Based on the magnetic structure reported previously by our group,
+the possible relevance of the non-trivial magnetic structure to the observed
+unusual behavior of rH is pointed out.",0608185v1
+2006-12-04,Magnetic-dipole induced appearance of vortices in a bilayered superconductor/soft-magnet heterostructure,"The penetration of the magnetic field of an infinitesimal magnetic dipole
+into a bilayered type-II superconductor/soft-magnet heterostructure is studied
+on the basis of the classical London approach. The critical values of the
+dipole moment for the first appearance of a single magnetic vortex and,
+respectively, a magnetic vortex-antivortex pair in the superconductor
+constituent are obtained, when the magnetic dipole faces the superconductor or
+the soft-magnet constituent. This reveals that the soft-magnet constituent
+inhibits penetration of vortices into the superconductor constituent, when the
+dipole faces the soft-magnet constituent.",0612083v1
+2007-04-12,Rich magnetic phase diagram in the Kagome-staircase compound Mn3V2O8,"Mn3V2O8 is a magnetic system in which S = 5/2 Mn2+ is found in the kagome
+staircase lattice. Here we report the magnetic phase diagram for temperatures
+above 2 K and applied magnetic fields below 9 T, characterized by measurements
+of the magnetization and specific heat with field along the three unique
+lattice directions. At low applied magnetic fields, the system first orders
+magnetically below Tm1 ~ 21 K, and then shows a second magnetic phase
+transition at Tm2 ~ 15 K. In addition, a phase transition that is apparent in
+specific heat but not seen in magnetization is found for all three applied
+field orientations, converging towards Tm2 as H -> 0. The magnetic behavior is
+highly anisotropic, with critical fields for magnetic phase boundaries much
+higher when the field is applied perpendicular to the Kagome staircase plane
+than when applied in-plane. The field-temperature (H - T) phase diagrams are
+quite rich, with 7 distinct phases observed.",0704.1581v1
+2007-09-07,Frustration-driven successive metamagnetic transitions in TbB4,"Resonant magnetic x-ray diffraction experiments on the Shastry-Sutherland
+lattice TbB$_4$ were carried out under strong pulsed magnetic fields up to 30
+T. TbB$_4$ exhibits a multi-step magnetization process above 16 T when magnetic
+fields are applied along the c-axis. We examined the intensity of the 010
+magnetic reflection as a function of magnetic field and found that the
+magnetization plateau phases are accompanied by large XY components of magnetic
+moments, in contrast to normal fractional magnetization plateau phases. The
+magnetization was calculated using a simple spin model deduced from the above
+result. Finally we propose that frustration is the key to understanding the
+observed multi-step magnetization.",0709.0977v2
+2007-10-09,Fermion Production in Strong Magnetic Field and its Astrophysical Implications,"We calculate the effective potential of a strong magnetic field induced by
+fermions with anomalous magnetic moments which couple to the electromagnetic
+field in the form of the Pauli interaction. For a uniform magnetic field, we
+find the explicit form of the effective potential. It is found that the
+non-vanishing imaginary part develops for a magnetic field stronger than a
+critical field and has a quartic form which is quite different from the
+exponential form of the Schwinger process. We also consider a linear magnetic
+field configuration as an example of inhomogeneous magnetic fields. We find
+that the imaginary part of the effective potential is nonzero even below the
+critical field and shows an exponentially decreasing behavior with respect to
+the inverse of the magnetic field gradient, which is the non-perturbative
+characteristics analogous to the Schwinger process. These results imply the
+instability of the strong magnetic field to produce fermion pairs as a purely
+magnetic effect. The possible applications to the astrophysical phenomena with
+strong magnetic field are also discussed.",0710.1670v1
+2008-05-14,Phenomenological theory of magnetization reversal in nanosystems with competing anisotropies,"The interplay between intrinsic and surface/interface-induced magnetic
+anisotropies strongly in- fluences magnetization processes in nanomagnetic
+systems. We develop a micromagnetic theory to describe the field-driven
+reorientation in nanomagnets with cubic and uniaxial anisotropies. Spin
+configurations in competing phases and parameters of accompanying multidomain
+states are calculated as functions of the applied field and the magnetic
+anisotropies. The constructed magnetic phase diagrams allow to classify
+different types of the magnetization reversal and to provide detailed analysis
+of the switching processes in magnetic nanostructures. The calculated
+magnetization profiles of isolated domain walls show that the equilibrium
+parameters of such walls are extremely sensitive to applied magnetic field and
+values of the competing anisotropies and can vary in a broad range. For
+nanolayers with perpendicular anisotropy the geometrical parameters of stripe
+domains have been calculated as functions of a bias field. The results are
+applied to analyse the magnetization processes as observed in various
+nanosystems with competing anisotropies, mainly, in diluted magnetic
+semiconductor films (Ga,Mn)As.",0805.1984v2
+2010-05-27,High-Field Magnetization of CeRu2Al10,"The magnetization measurements of CexLa1-xRu2Al10 (x = 1, 0.75) under the
+high magnetic field were performed in order to obtain the information for the
+long-range order (LRO) in CeRu2Al10. We successfully obtained the magnetic
+phase diagram of these two compounds for the applied magnetic field along the
+a-axis which is the magnetization easy axis, and found that the LRO for x = 1
+disappears at ~50 T which is the critical field to the paramagnetic phase. For
+x = 0.75, the critical magnetic field decreases to ~37 T by La substitution.
+The magnetic phase diagram and magnetization curve are qualitatively consistent
+with the recent Hanzawa's mean field calculation results obtained by assuming
+the dimer of Ce ions whose crystalline electric field ground state has a large
+magnetic anisotropy. These results support the singlet pair formation scenario
+recently proposed by Tanida et al.. We also pointed out the possibility of the
+appearance of the field-induced magnetic phase between ~40 T and ~50 T for x =
+1.",1005.5079v1
+2010-10-15,Synthesis and magnetic properties of Mn12-based single molecular magnets with benzene and pentafluorobenzene carboxylate ligands,"We report on the synthesis and magnetic properties of Mn12-based single
+molecular magnets (SMMs) with benzene and pentafluorobenzene carboxylate
+ligands. The changes in ligand structure are shown to have a decisive effect on
+magnetic properties of produced complexes. The compound with benzene
+demonstrates unusual magnetic behaviour, namely, temperature dependencies of
+magnetization taken under the zero field cooled and field cooled conditions are
+split below 10 K and furthermore remnant magnetization and coercive force
+remain nonzero in this temperature range. In contrast, compound with
+pentafluorobenzene displays the customary signatures of a blocking temperature
+at 3K. The effect of ligand substitution was theoretically studied within local
+density approximation taking into account on-site Coloumb repulsion.
+Calculation results confirm that the electronic structure and the magnetic
+exchange interactions between different Mn atoms strongly depend on the type of
+ligands.",1010.3057v1
+2011-07-14,Magneto-sensitive elastomers in a homogeneous magnetic field: a regular rectangular lattice model,"A theory of mechanical behaviour of the magneto-sensitive elastomers is
+developed in the framework of a linear elasticity approach. Using a regular
+rectangular lattice model, different spatial distributions of magnetic
+particles within a polymer matrix are considered: isotropic, chain-like and
+plane-like. It is shown that interaction between the magnetic particles results
+in the contraction of an elastomer along the homogeneous magnetic field. With
+increasing magnetic field the shear modulus for the shear deformation
+perpendicular to the magnetic field increases for all spatial distributions of
+magnetic particles. At the same time, with increasing magnetic field the
+Young's modulus for tensile deformation along the magnetic field decreases for
+both chain-like and isotropic distributions of magnetic particles and increases
+for the plane-like distribution of magnetic particles.",1107.2768v1
+2011-11-27,A first-order magnetic phase transition near 15 K with novel magnetic-field-induced effects in Er5Si3,"We present magnetic characterization of a binary rare-earth intermetallic
+compound Er5Si3, crystallizing in Mn5Si3-type hexagonal structure, through
+magnetization, heat-capacity, electrical resistivity, and magnetoresistance
+measurements. Our investigations confirm that the compound exhibits two
+magnetic transitions with decreasing temperature, first one at 35 K and the
+second one at 15 K. The present results reveal that the second magnetic
+transition is a disorder-broadened first-order transition, as shown by thermal
+hysteresis in the measured data. Another important finding is that, below 15 K,
+there is a magnetic-field-induced transition with a hysteretic effect with the
+electrical resistance getting unusually enhanced at this transition and the
+magnetorsistance (MR) is found to exhibit intriguing magnetic-field dependence
+indicating novel magnetic phase-co-existence phenomenon. It thus appears that
+this compound is characterized by interesting magnetic anomalies in the
+temperature-magnetic-field phase diagram.",1111.6240v1
+2012-02-15,Ferroelectricity induced by interatomic magnetic exchange interaction,"Multiferroics, where two or more ferroic order parameters coexist, is one of
+the hottest fields in condensed matter physics and materials science[1-9].
+However, the coexistence of magnetism and conventional ferroelectricity is
+physically unfavoured[10]. Recently several remedies have been proposed, e.g.,
+improper ferroelectricity induced by specific magnetic[6] or charge orders[2].
+Guiding by these theories, currently most research is focused on frustrated
+magnets, which usually have complicated magnetic structure and low magnetic
+ordering temperature, consequently far from the practical application. Simple
+collinear magnets, which can have high magnetic transition temperature, have
+never been considered seriously as the candidates for multiferroics. Here, we
+argue that actually simple interatomic magnetic exchange interaction already
+contains a driving force for ferroelectricity, thus providing a new microscopic
+mechanism for the coexistence and strong coupling between ferroelectricity and
+magnetism. We demonstrate this mechanism by showing that even the simplest
+antiferromagnetic (AFM) insulator MnO, can display a magnetically induced
+ferroelectricity under a biaxial strain.",1202.3381v2
+2012-03-01,Observations of Cool-Star Magnetic Fields,"Cool stars like the Sun harbor convection zones capable of producing
+substantial surface magnetic fields leading to stellar magnetic activity. The
+influence of stellar parameters like rotation, radius, and age on cool-star
+magnetism, and the importance of the shear layer between a radiative core and
+the convective envelope for the generation of magnetic fields are keys for our
+understanding of low-mass stellar dynamos, the solar dynamo, and also for other
+large-scale and planetary dynamos. Our observational picture of cool-star
+magnetic fields has improved tremendously over the last years. Sophisticated
+methods were developed to search for the subtle effects of magnetism, which are
+difficult to detect particularly in cool stars. With an emphasis on the
+assumptions and capabilities of modern methods used to measure magnetism in
+cool stars, I review the different techniques available for magnetic field
+measurements. I collect the analyses on cool-star magnetic fields and try to
+compare results from different methods, and I review empirical evidence that
+led to our current picture of magnetic fields and their generation in cool
+stars and brown dwarfs.",1203.0241v1
+2012-06-02,Electric dipoles on magnetic monopoles in spin ice,"The close connection of electricity and magnetism is one of the cornerstones
+of modern physics. This connection plays crucial role from the fundamental
+point of view and in practical applications, including spintronics and
+multiferroic materials. A breakthrough was a recent proposal that in magnetic
+materials called spin ice the elementary excitations have a magnetic charge and
+behave as magnetic monopoles. I show that, besides magnetic charge, there
+should be an electric dipole attached to each magnetic monopole. This opens new
+possibilities to study and to control such monopoles by electric field. Thus
+the electric--magnetic analogy goes even further than usually assumed: whereas
+electrons have electric charge and magnetic dipole (spin), magnetic monopoles
+in spin ice, while having magnetic charge, also have electric dipole.",1206.0402v1
+2012-06-30,On conservation of the of crystal lattice symmetry in transition at Curie point in exchange magnets,"We show that symmetry of the crystal lattice of exchange magnets (containing
+only 3d magneto-active elements) does not change at the Curie point; only the
+magnetic symmetry of the crystal is decreasing in the transition point. In the
+non-exchange magnets (containing only rare-earth magneto-active elements), on
+the contrary, both the magnetic and crystal-chemical symmetry decrease at the
+Curie point. There is isotropic magnetic phase in exchange magnets; and their
+magnetic symmetry is described by color groups of magnetic symmetry of P-type.
+Non-exchange magnets do not have isotropic phase; their symmetry is described
+by color groups of magnetic symmetry of Q-type.",1207.0049v1
+2012-07-30,Magnetic energy harvesting and concentration at distance by transformation optics,"Magnetic energy is one the main agents powering our society: generating
+energy in power plants, keeping information in magnetic memories, moving our
+devices with motors. All of these applications require a certain spatial
+distribution of magnetic energy, for example concentrating it in a transformer
+core or in a magnetic sensor. We introduce in this work a way to collect
+magnetic energy and distribute it in space with unprecedented efficiency and
+flexibility, allowing very large concentration of magnetic energy in a free
+space region, an enhanced magnetic coupling between two magnetic sources, and
+the transfer of magnetic energy from a source to a given distant point
+separated by empty space. All these features are achieved with a single device,
+a magnetic shell designed by transformation optics.",1207.7030v1
+2012-11-30,Spontaneous magnetization and magnetic susceptibility of LaVO3,"Five characteristic temperatures of TM = 148 K, TN = 142 K, Tt = 138 K, Tf ~
+125 K and Tg ~ 50 K were found by the measurements of the magnetization curves
+at various temperature. The spontaneous magnetization appears below TM. It
+increases up to M_{S} simeq 2 times 10^{-4} mu_{B} at Tt and then decreases
+steeply below Tt, which qualitatively agrees with the temperature dependence of
+magnetization obtained under field-cooling (FC) condition. On the other hand,
+the slope of the magnetization curve, namely the magnetic susceptibility, drops
+below TN, which coincides with the temperature dependence of magnetization
+obtained under zero-FC condition, although the magnetization curves were
+obtained under FC condition. The temperature dependence of the spontaneous
+magnetization shows a minimum at Tf and a drop at Tg although there is no
+anomaly in the temperature dependence of FC or ZFC magnetization.",1211.7179v1
+2013-02-01,Frequency Adapted Phase Transition of Interacting Nano-Magnetic Ensemble,"Each single domain nano-magnet acts as a magnetic dipole in addition it
+oscillates its magnetization about the easy axis and rotates coherently
+depending upon temperature and anisotropy. In an ensemble of nano-magnets, the
+relaxation time of a nano-magnet tunes with the long range dipolar interaction
+which in turn is determined by the particle size, density and the number of
+nano-magnets present in the ensemble. Hence, the aggregation of interacting
+nano-magnetic dipoles, demonstrates both experimentally and theoretically as a
+model system to detect intriguing co-operative physical phenomena. Here we show
+a new variant of phase transition from paramagnetic to diamagnetic phase by
+changing the frequency of the applied sinusoidal magnetic field for a
+nano-magnetic ensemble. This phenomenon unravels a new insight of physics and
+it may be significant on the design and development of magnetic devices. The
+simulation of the system is well in agreement with the experimental results.",1302.0086v1
+2013-03-30,Defect-Induced Magnetism in Solids,"In the last years the number of nominally non-magnetic solids showing
+magnetic order induced by some kind of defects has increased continuously. From
+the single element material graphite to several covalently bonded non-magnetic
+compounds, the influence of defects like vacancies and/or non-magnetic ad-atoms
+on triggering magnetic order has attracted the interest of experimentalists and
+theoreticians. We review and discuss the main theoretical approach as well as
+recently obtained experimental evidence based on different experimental methods
+that supports the existence of defect-induced magnetism (DIM) in non-magnetic
+as well as in magnetic materials.",1304.0137v1
+2013-04-22,Chiral Disorder and Random Matrix Theory with Magnetism,"We revisit the concept of chiral disorder in QCD in the presence of a QED
+magnetic field |eH|. Weak magnetism corresponds to |eH| < 1/rho^2 with
+rho\approx (1/3) fm the vacuum instanton size, while strong magnetism the
+reverse. Asymptotics (ultra-strong magnetism) is in the realm of perturbative
+QCD. We analyze weak magnetism using the concept of the quark return
+probability in the diffusive regime of chiral disorder. The result is in
+agreement with expectations from chiral perturbation theory. We analyze strong
+and ultra-strong magnetism in the ergodic regime using random matrix theory
+including the effects of finite temperature. The strong magnetism results are
+in agreement with the currently reported lattice data in the presence of a
+small shift of the Polyakov line. The ultra-strong magnetism results are
+consistent with expectations from perturbative QCD. We suggest a chiral random
+matrix effective action with matter and magnetism to analyze the QCD phase
+diagram near the critical points under the influence of magnetism.",1304.6020v2
+2013-10-30,Passive Magnetic Shielding in Gradient Fields,"The effect of passive magnetic shielding on dc magnetic field gradients
+imposed by both external and internal sources is studied. It is found that for
+concentric cylindrical or spherical shells of high permeability material,
+higher order multipoles in the magnetic field are shielded progressively
+better, by a factor related to the order of the multipole. In regard to the
+design of internal coil systems for the generation of uniform internal fields,
+we show how one can take advantage of the coupling of the coils to the
+innermost magnetic shield to further optimize the uniformity of the field.
+These results demonstrate quantitatively a phenomenon that was previously
+well-known qualitatively: that the resultant magnetic field within a passively
+magnetically shielded region can be much more uniform than the applied magnetic
+field itself. Furthermore we provide formulae relevant to active magnetic
+compensation systems which attempt to stabilize the interior fields by sensing
+and cancelling the exterior fields close to the outermost magnetic shielding
+layer. Overall this work provides a comprehensive framework needed to analyze
+and optimize dc magnetic shields, serving as a theoretical and conceptual
+design guide as well as a starting point and benchmark for finite-element
+analysis.",1310.8242v1
+2013-11-12,Magnetic and Dielectric Properties in Multiferroic Cu3Mo2O9 under High Magnetic Fields,"The magnetic and dielectric properties under high magnetic fields are studied
+in the single crystal of Cu3Mo2O9. This multiferroic compound has distorted
+tetrahedral spin chains. The effects of the quasi-one dimensionality and the
+geometrical spin frustration are expected to appear simultaneously. We measure
+the magnetoelectric current and the differential magnetization under the pulsed
+magnetic field up to 74 T. We also measure the electric polarization versus the
+electric field curve/loop under the static field up to 23 T. Dielectric
+properties change at the magnetic fields where the magnetization jumps are
+observed in the magnetization curve. Moreover, the magnetization plateaus are
+found at high magnetic fields.",1311.2706v1
+2013-12-04,Quantum s = 1/2 Antiferromagnets on Archimedean Lattices: The Route from Semiclassical Magnetic Order to Nonmagnetic Quantum States,"We investigate ground states of $s$=1/2 Heisenberg antiferromagnets on the
+eleven two-dimensional (2D) Archimedian lattices by using the coupled cluster
+method. Magnetic interactions and quantum fluctuations play against each other
+subtly in 2D quantum magnets and the magnetic ordering is thus sensitive to the
+features of lattice topology. Archimedean lattices are those lattices that have
+2D arrangements of regular polygons and they often build the underlying
+magnetic lattices of insulating quasi-two-dimensional quantum magnetic
+materials. Hence they allow a systematic study of the relationship between
+lattice topology and magnetic ordering. We find that the Archimedian lattices
+fall into three groups: those with semiclassical magnetic ground-state
+long-range order, those with a magnetically disordered (cooperative quantum
+paramagnetic) ground state, and those with a fragile magnetic order. The most
+relevant parameters affecting the magnetic ordering are the coordination number
+and the degree of frustration present.",1312.1203v1
+2014-01-18,Evolution of the 2D antiferromagnetism with temperature and magnetic field in multiferroic Ba$_2$CoGe$_2$O$_7$,"We report on spherical neutron polarimetry and unpolarized neutron
+diffraction in zero magnetic field as well as flipping ratio and static
+magnetization measurements in high magnetic fields on the multiferroic square
+lattice antiferromagnet Ba$_2$CoGe$_2$O$_7$. We found that in zero magnetic
+field the magnetic space group is $Cm'm2'$ with sublattice magnetization
+parallel to the [100] axis of this orthorhombic setting. The spin canting has
+been found to be smaller than $0.2^\circ$ in the ground state. This assignment
+is in agreement with the field-induced changes of the magnetic domain structure
+below 40 mT as resolved by spherical neutron polarimetry. The magnitude of the
+ordered moment has been precisely determined. Above the magnetic ordering
+temperature short-range magnetic fluctuations are observed. Based on the
+high-field magnetization data, we refined the parameters of the recently
+proposed microscopic spin model describing the multiferroic phase of
+Ba$_2$CoGe$_2$O$_7$.",1401.4517v1
+2014-01-27,Topological magnetic crystalline insulators and co-representation theory,"Gapless surface states of time reversal invariant topological insulators are
+protected by the anti-unitary nature of the time reversal operation. Very
+recently, this idea was generalized to magnetic structures, in which time
+reversal symmetry is explicitly broken, but there is still an anti-unitary
+symmetry operation combining time reversal symmetry and crystalline symmetry.
+These topological phases in magnetic structures are dubbed ""topological
+magnetic crystalline insulators"". In this work, we present a general theory of
+topological magnetic crystalline insulators in different types of magnetic
+crystals based on the co-representation theory of magnetic crystalline symmetry
+groups. We construct two concrete tight-binding models of topological magnetic
+crystalline insulators, the $\hat{C}_4\Theta$ model and the $\hat{\bf
+\tau}\Theta$ model, in which topological surface states and topological
+invariants are calculated explicitly. Moreover, we check different types of
+anti-unitary operators in magnetic systems and find that the systems with
+$\hat{C}_4\Theta$, $\hat{C}_6\Theta$ and $\hat{\bf \tau}\Theta$ symmetry are
+able to protect gapless surface states. Our work will pave the way to search
+for topological magnetic crystalline insulators in realistic magnetic
+materials.",1401.6922v1
+2014-02-28,The role of magnetic fields in pre-main sequence stars,"Strong, kilo-Gauss, magnetic fields are required to explain a range of
+observational properties in young, accreting pre-main sequence (PMS) systems.
+We review the techniques used to detect magnetic fields in PMS stars. Key
+results from a long running campaign aimed at characterising the large scale
+magnetic fields in accreting T Tauri stars are presented. Maps of surface
+magnetic flux in these systems can be used to build 3-D models exploring the
+role of magnetic fields and the efficiency with which magnetic fields can
+channel accretion from circumstellar disks on to young stars. Long-term
+variability in T Tauri star magnetic fields strongly point to a dynamo origin
+of the magnetic fields. Studies are underway to quantify how changes in
+magnetic fields affect their accretion properties. We also present the first
+results from a new programme that investigates the evolution of magnetic fields
+in intermediate mass (1.5-3 Msun) pre-main sequence stars as they evolve from
+being convective T Tauri stars to fully radiative Herbig AeBe stars.",1402.7130v1
+2014-05-09,A Statistical Study on Property of Spatial Magnetic Field for Solar Active Region,"Magnetic fields dominate most solar activities, there exist direct relations
+between solar flare and the distributions of magnetic field, and also its
+corresponding magnetic energy. In this paper, the statistical results about the
+relationships between the spatial magnetic field and solar flare are given
+basing on vector magnetic field observed by the Solar Magnetic Field Telescope
+(SMFT) at Huairou Solar Observing Station (HSOS). The spatial magnetic fields
+are obtained by extrapolated photosphere vector magnetic field observed by
+SMFT. There are 23 active regions with flare eruption are chosen as data
+samples, which were observed from 1997 to 2007. The results are as follows: 1.
+Magnetic field lines become lower after flare for 16(69%) active regions; 2.
+The free energy are decreased after flare for 17 (74%) active regions. It can
+conclude that for most active regions the changes of magnetic field after solar
+flare are coincident with the previous observations and studies.",1405.2149v1
+2014-08-06,Permanent magnet with MgB2 bulk superconductor,"Superconductors with persistent zero-resistance currents serve as permanent
+magnets for high-field applications requiring a strong and stable magnetic
+field, such as magnetic resonance imaging (MRI). The recent global helium
+shortage has quickened research into high-temperature superconductors (HTSs)
+materials that can be used without conventional liquid-helium cooling to 4.2 K.
+Herein, we demonstrate that 40-K-class metallic HTS magnesium diboride (MgB2)
+makes an excellent permanent bulk magnet, maintaining 3 T at 20 K for 1 week
+with an extremely high stability (<0.1 ppm/h). The magnetic field trapped in
+this magnet is uniformly distributed, as for single-crystalline
+neodymium-iron-boron. Magnetic hysteresis loop of the MgB2 permanent bulk
+magnet was detrmined. Because MgB2 is a simple-binary-line compound that does
+not contain rare-earth metals, polycrystalline bulk material can be
+industrially fabricated at low cost and with high yield to serve as strong
+magnets that are compatible with conventional compact cryocoolers, making MgB2
+bulks promising for the next generation of Tesla-class permanent-magnet
+applications.",1408.1277v1
+2014-08-17,Creation of magnetic spots at the neutron star surface,"According to the partially screened gap scenario, an efficient
+electron-positron pair creation, a general precondition of radio-pulsar
+activity, relies on the existence of magnetic spots, i.e., local concentrations
+of strong and small scale magnetic field structures at the surface of neutron
+stars. They have a strong impact on the surface temperature, which is
+potentially observable. Here we reinforce the idea that such magnetic spots can
+be formed by extracting magnetic energy from the toroidal field that resides in
+deep crustal layers, via Hall drift. We study and discuss the magneto-thermal
+evolution of qualitatively different neutron star models and initial magnetic
+field configurations that lead to the creation of magnetic spots. We find that
+magnetic spots can be created on a timescale of $10^4$ years with magnetic
+field strengths $\gtrsim 5\times 10^{13}$ G, provided almost the whole magnetic
+energy is stored in its toroidal component, and that the conductivity in the
+inner crust is not too large. The lifetime of the magnetic spots is at least
+$\sim$one million of years, being longer if the initial field permeates both
+core and crust.",1408.3833v1
+2014-09-28,Surface and interface effects on a magnetic Chern insulator,"Effects of an open surface on a magnetic Chern insulator are investigated in
+comparison with those of an interface to a capping magnetic layer. In magnets,
+an open surface often perturbs the magnetic order by a reconstruction of the
+magnetic moment directions near the surface. On the other hand, in topological
+insulators, it leads to the formation of topologically protected surface
+states. These two contrasting effects may coexist in magnetic Chern insulators,
+which give rise to nontrivial surface reconstruction. For instance, the chiral
+edge current is largely enhanced by the edge reconstruction in a
+two-dimensional magnetic Chern insulator realized in a quarter-filled Kondo
+lattice model on a triangular lattice. We here show that the edge
+reconstruction can be described semiquantitatively by a simple junction model
+between the bulk topological magnetic state and a ferromagnetic capping layer.
+We further clarify how the chiral edge current is affected by the magnetic
+structure in the capping layer. Our results indicate that the topological edge
+state can be controlled magnetically through the junctions.",1409.7939v1
+2014-09-29,Validation of the magnetic energy vs. helicity scaling in solar magnetic structures,"We assess the validity of the free magnetic energy - relative magnetic
+helicity diagram for solar magnetic structures. We used two different methods
+of calculating the free magnetic energy and the relative magnetic helicity
+budgets: a classical, volume-calculation nonlinear force-free (NLFF) method
+applied to finite coronal magnetic structures and a surface-calculation NLFF
+derivation that relies on a single photospheric or chromospheric vector
+magnetogram. Both methods were applied to two different data sets, namely
+synthetic active-region cases obtained by three-dimensional
+magneto-hydrodynamic (MHD) simulations and observed active-region cases, which
+include both eruptive and noneruptive magnetic structures. The derived
+energy--helicity diagram shows a consistent monotonic scaling between relative
+helicity and free energy with a scaling index 0.84$\pm$0.05 for both data sets
+and calculation methods. It also confirms the segregation between noneruptive
+and eruptive active regions and the existence of thresholds in both free energy
+and relative helicity for active regions to enter eruptive territory. We
+consider the previously reported energy-helicity diagram of solar magnetic
+structures as adequately validated and envision a significant role of the
+uncovered scaling in future studies of solar magnetism.",1409.8117v1
+2014-12-29,Electrically Tunable Magnetism in Magnetic Topological Insulators,"The external controllability of the magnetic properties in topological
+insulators would be important both for fundamental and practical interests.
+Here we predict the electric-field control of ferromagnetism in a thin film of
+insulating magnetic topological insulators. The decrease of band inversion by
+the application of electric fields results in a reduction of magnetic
+susceptibility, and hence in the modification of magnetism. Remarkably, the
+electric field could even induce the magnetic quantum phase transition from
+ferromagnetism to paramagnetism. We further propose a topological transistor
+device in which the dissipationless charge transport of chiral edge states is
+controlled by an electric field. In particular, the field-controlled
+ferromagnetism in magnetic topological insulator can be used for voltage based
+writing of magnetic random access memories in magnetic tunnel junctions. The
+simultaneous electrical control of magnetic order and chiral edge transport in
+such devices may lead to electronic and spintronic applications for topological
+insulators.",1412.8237v5
+2014-12-29,Magnetic balltracking: Tracking the photospheric magnetic flux,"Context: One aspect of understanding the dynamics of the quiet Sun is to
+quantify the evolution of the flux within small-scale magnetic features. These
+features are routinely observed in the quiet photosphere and were given various
+names, such as pores, knots, magnetic patches. Aims: This work presents a new
+algorithm for tracking the evolution of the broad variety of small-scale
+magnetic features in the photosphere, with a precision equal to the
+instrumental resolution. Methods: We have developed a new technique to track
+the evolution of the individual magnetic features from magnetograms, called
+""magnetic balltracking"". It quantifies the flux of the tracked features, and it
+can track the footpoints of magnetic field lines inferred from magnetic field
+extrapolation. The algorithm can detect and quantify flux emergence, as well as
+flux cancellation. Results: The capabilities of magnetic balltracking are
+demonstrated with the detection and the tracking of two cases of magnetic flux
+emergence that lead to the brightening of X-ray loops. The maximum emerged flux
+ranges from 10^{18} Mx to 10^{19} Mx (unsigned flux) when the X-ray loops are
+observed.",1412.8294v1
+2015-01-27,Magnetic behavior of the metal organic framework solid: [(CH3)2NH2][Co(HCOO)3],"In this study we examine the phase transitions in single crystals of
+[(CH3)2NH2]Co(HCOO)3], using magnetization and specific heat measurements as a
+function of temperature and magnetic field. Magnetisation measurements indicate
+a transition at 15 K that is associated with an antiferromagnetic transition.
+The results of the isothermal magnetization versus magnetic field curves
+demonstrate the presence of a single-ion magnet phase, coexisting with
+antiferromagnetism. A peak in specific heat is seen at 15 K, corresponding to
+the magnetic transition. The enthalpy of the transition evaluated from the area
+under the specific heat peak decreases with the application of magnetic field
+of upto8 T. This is suggestive of long range antiferromagnetic magnetic order,
+giving way to single-ion magnetic behavior under external field. In experiments
+at high temperatures, corresponding to the well-known structural transition in
+this system, the specific heat measurements, shows a peak at ~155K, that is
+insensitive to applied magnetic field. The magnetisation in this temperature
+range, while it exhibits a paramagnetic behavior, shows a distinct jump that
+has been attributed to a spin-state transition of Co2+ associated with the
+structural transition.",1501.06651v1
+2015-03-27,Magnetized relativistic stellar models in Eddington-inspired Born-Infeld gravity,"We consider the structure of the magnetic fields inside the neutron stars in
+Eddington-inspired Born-Infeld (EiBI) gravity. In order to construct the
+magnetic fields, we derive the relativistic Grad-Shafranov equation in EiBI,
+and numerically determine the magnetic distribution in such a way that the
+interior magnetic fields should be connected to the exterior distribution.
+Then, we find that the magnetic distribution inside the neutron stars in EiBI
+is qualitatively similar to that in general relativity, where the deviation of
+magnetic distribution in EiBI from that in general relativity is almost
+comparable to uncertainty due to the equation of state (EOS) for the neutron
+star matter. However, we also find that the magnetic fields in the crust region
+are almost independent of the coupling constant in EiBI, which suggests a
+possibility to obtain the information about the crust EOS independently of the
+gravitational theory via the observations of the phenomena associated with the
+crust region. In any case, since the imprint of EiBI gravity on the magnetic
+fields is weak, the magnetic fields could be a poor probe of gravitational
+theories, considering many magnetic uncertainties.",1503.07942v2
+2015-05-24,Magnetic reversal modes in multisegmented nanowire arrays with long aspect ratio,"A detailed numerical analysis of the magnetization reversal processes in
+multisegmented nanowire arrays was developed. The nanowires have a long aspect
+ratio and are formed by magnetic and non-magnetic sections alternately arranged
+in such a way that the array resembles magnetic layers separated by
+non-magnetic layers. Attention has been focused on the influence of
+magnetostatic interaction in the magnetic pattern formation of these magnetic
+nanostructures. Results from a magnetic correlation function among layers show
+that three different reversal modes can be detected depending on the number and
+distance between the magnetic segments. As a consequence of the different
+reversal modes, a non-monotonic behavior of the annihilation field in function
+of the distance between the layers is evidenced. Thus, these results are
+important for the production of magnetic devices with multisegmented nanowire
+arrays.",1505.06491v2
+2015-06-03,Proximity-induced magnetism in transition-metal substituted graphene,"We investigate the interactions between two identical magnetic impurities
+substituted into a graphene superlattice. Using a first-principles approach, we
+calculate the electronic and magnetic properties for transition-metal
+substituted graphene systems with varying spatial separation. These
+calculations are compared for three different magnetic impurities, manganese,
+chromium, and vanadium. We determine the electronic band structure, density of
+states, and Millikan populations (magnetic moment) for each atom, as well as
+calculate the exchange parameter between the two magnetic atoms as a function
+of spatial separation. We find that the presence of magnetic impurities
+establishes a distinct magnetic moment in the graphene lattice, where the
+interactions are highly dependent on the spatial and magnetic characteristic
+between the magnetic atoms and the carbon atoms, which leads to either
+ferromagnetic or antiferromagnetic behavior. Furthermore, through an analysis
+of the calculated exchange energies and partial density of states, it is
+determined that interactions between the magnetic atoms can be classified as an
+RKKY interaction.",1506.01319v1
+2015-06-26,Non-axisymmetric magnetic modes of neutron stars with purely poloidal magnetic fields,"We calculate non-axisymmetric oscillations of neutron stars magnetized by
+purely poloidal magnetic fields. We use polytropes of index $n=1$ and 1.5 as a
+background model, where we ignore the equilibrium deformation due to the
+magnetic field. Since separation of variables is not possible for the
+oscillation of magnetized stars, we employ finite series expansions for the
+perturbations using spherical harmonic functions. Solving the oscillation
+equations as the boundary and eigenvalue problem, we find two kinds of discrete
+magnetic modes, that is, stable (oscillatory) magnetic modes and unstable
+(monotonically growing) magnetic modes. For isentropic models, the frequency or
+the growth rate of the magnetic modes is exactly proportional to $B_{\rm S}$,
+the strength of the field at the surface. The oscillation frequency and the
+growth rate are affected by the buoyant force in the interior, and the stable
+stratification tends to stabilize the unstable magnetic modes.",1507.00314v2
+2015-09-02,Dynamo model for the inverse transfer of magnetic energy in a nonhelical decaying magnetohydrodynamic turbulence,"The inverse cascade of magnetic energy occurs when helicity or rotational
+instability exists in the magnetohydrodynamic (MHD) system. This well known
+phenomenon has been considered as a basis for the large scale magnetic field in
+universe. However nonhelical magnetic energy in a decaying MHD system also
+migrates toward the large scale, which holds vital clues to the origin of large
+scale magnetic field in a quiescent astrophysical system. Zeldovich's rope
+dynamo model is considered as a basic and symbolistic model of magnetic field
+amplification. However, the rope model assuming specific external forces like
+buoyancy or Coriolis force is not appropriate for a decaying turbulent system
+without any external force. So we suggest a new dynamo model based on magnetic
+induction equation excluding a forcing source. This model shows the expansion
+and growth of magnetic field (flux) is basically the redistribution of energy
+in the system. The transfer of magnetic energy is in fact a successive
+induction of magnetic field resulted from the interaction between the fluid
+motion and seed magnetic field. We also discuss about an analytic theorem based
+on the scaling invariant MHD equation.",1509.00788v3
+2015-10-16,Enhanced orbital magnetic moments in magnetic heterostructures with interface perpendicular magnetic anisotropy,"We have studied the magnetic layer thickness dependence of the orbital
+magnetic moment in magnetic heterostructures to identify contributions from
+interfaces. Three different heterostructures, Ta/CoFeB/MgO, Pt/Co/AlO$_x$ and
+Pt/Co/Pt, which possess significant interface contribution to the perpendicular
+magnetic anisotropy, are studied as model systems. X-ray magnetic circular
+dichroism spectroscopy is used to evaluate the relative orbital moment, i.e.
+the ratio of the orbital to spin moments, of the magnetic elements constituting
+the heterostructures. We find that the relative orbital moment of Co in
+Pt/Co/Pt remains constant against its thickness whereas the moment increases
+with decreasing Co layer thickness for Pt/Co/AlO$_x$, suggesting that a
+non-zero interface orbital moment exists for the latter system. For
+Ta/CoFeB/MgO, a non-zero interface orbital moment is found only for Fe. X-ray
+absorption spectra shows that a particular oxidized Co state in Pt/Co/AlO$_x$,
+absent in other heterosturctures, may give rise to the interface orbital moment
+in this system. These results show element specific contributions to the
+interface orbital magnetic moments in ultrathin magnetic heterostructures.",1510.04756v1
+2015-11-23,Magnetic neutron scattering by magnetic vortices in thin submicron-sized soft ferromagnetic cylinders,"Using analytical expressions for the magnetization textures of thin
+submicron-sized magnetic cylinders in vortex state, we derive closed-form
+algebraic expressions for the ensuing small-angle neutron scattering (SANS)
+cross sections. Specifically, for the perpendicular and parallel scattering
+geometries, we have computed the magnetic SANS cross sections for the case of
+small vortex-center displacements without formation of magnetic charges on the
+side faces of the cylinder. The results represent a significant qualitative and
+quantitative step forward in SANS-data analysis on isolated magnetic
+nanoparticle systems, which are commonly assumed to be homogeneously or
+stepwise-homogeneously magnetized. We suggest a way to extract the fine details
+of the magnetic vortex structure during the magnetization process from the SANS
+measurements in order to help resolving the long standing question of the
+magnetic vortex displacement mode.",1511.07282v1
+2015-12-04,Numerical calculations of magnetic properties of nanostructures,"Magnetic force microscopy and scanning tunneling microscopy data could be
+used to test computer numerical models of magnetism. The elaborated numerical
+model of a face-centered lattice Ising spins is based on pixel distribution in
+the image of magnetic nanostructures obtained by using scanning microscope.
+Monte Carlo simulation of the magnetic structure model allowed defining the
+temperature dependence of magnetization; calculating magnetic hysteresis curves
+and distribution of magnetization on the surface of submonolayer and monolayer
+nanofilms of cobalt, depending on the experimental conditions. Our developed
+package of supercomputer parallel software destined for a numerical simulation
+of the magnetic-force experiments and allows obtaining the distribution of
+magnetization in one-dimensional arrays of nanodots and on their basis. There
+has been determined interpretation of magneto-force microscopy images of
+magnetic nanodots states. The results of supercomputer simulations and
+numerical calculations are in the good compliance with experimental data.",1512.01309v1
+2016-01-21,Vortex Dynamics-Mediated Low-Field Magnetization Switching in an Exchange-Coupled System,"A magnetic vortex has attracted significant attention since it is a
+topologically stable magnetic structure in a soft magnetic nanodisk. Many
+studies have been devoted to understanding the nature of magnetic vortex in
+isolated systems. Here we show a new aspect of a magnetic vortex the dynamics
+of which strongly affects the magnetic structures of environment. We exploit a
+nanodot of an exchange-coupled bilayer with a soft magnetic Ni81Fe19
+(permalloy; Py) having a magnetic vortex and a perpendicularly magnetized
+L10-FePt exhibiting a large switching field (Hsw). The vortex dynamics with
+azimuthal spin waves makes the excess energy accumulate in the Py, which
+triggers the reversed-domain nucleation in the L10-FePt at a low magnetic
+field. Our results shed light on the non-local mechanism of a reversed-domain
+nucleation, and provide with a route for efficient Hsw reduction that is needed
+for ultralow-power spintronic devices.",1601.05521v1
+2016-03-17,Trends in magnetism of free Rh clusters via relativistic ab-initio calculations,"A fully relativistic ab-initio study on free Rh clusters of 13-135 atoms is
+performed to identify general trends concerning their magnetism and to check
+whether concepts which proved to be useful in interpreting magnetism of 3d
+metals are applicable to magnetism of 4d systems. We found that there is no
+systematic relation between local magnetic moments and coordination numbers. On
+the other hand, the Stoner model appears well-suited both as a criterion for
+the onset of magnetism and as a guide for the dependence of local magnetic
+moments on the site-resolved density of states at the Fermi level. Large
+orbital magnetic moments antiparallel to spin magnetic moments were found for
+some sites. The intra-atomic magnetic dipole Tz term can be quite large at
+certain sites but as a whole it is unlikely to affect the interpretation of
+x-ray magnetic circular dichroism experiments based on the sum rules.",1603.05394v1
+2016-05-09,Magnetic phase diagram of TbMn$_{1-x}$Fe$_x$O$_3$ $(0 \leq x \leq 1)$ substitutional solid solution,"We present the magnetic phase diagram of TbMn1-xFexO3 substitutional solid
+solution in the whole concentration range 0 <= x <= 1 as determined from
+magnetization and specific heat measurements. We have found that the dominant
+magnetic ion in the concentration range 0 <= x < 0.3 is manganese, while iron
+ions do not create independent magnetic structure, but strongly affect magnetic
+properties of the parent compound by reducing transition to magnetically
+ordered state and transition into a cycloidal phase. The magnetism in the
+concentration range 0.3 < x <= 1 is driven by the Fe sublattice. The manganese
+ions again do not order in long range magnetic ordered state, but stabilize
+four different magnetic structures of Fe sublattice above 2 K. The magnetic
+ordering of Tb sublattice was observed only on parent compounds TbMnO3 and
+TbFeO3 and for doping level below 0.1, or over 0.9.",1605.02503v2
+2016-07-28,Effective penetration length and interstitial vortex pinning in superconducting films with regular arrays of defects,"In order to compare magnetic and non-magnetic pinning we have nanostructured
+two superconducting films with regular arrays of pinning centers: Cu
+(non-magnetic) dots in one case, and Py (magnetic) dots in the other. For low
+applied magnetic fields, when all the vortices are pinned in the artificial
+inclusions, magnetic dots prove to be better pinning centers, as has been
+generally accepted. Unexpectedly, when the magnetic field is increased and
+interstitial vortices appear, the results are very different: we show how the
+stray field generated by the magnetic dots can produce an effective reduction
+of the penetration length. This results in strong consequences in the transport
+properties, which, depending on the dot separation, can lead to an enhancement
+or worsening of the transport characteristics. Therefore, the election of the
+magnetic or non-magnetic character of the pinning sites for an effective
+reduction of dissipation will depend on the range of the applied magnetic
+field.",1607.08416v1
+2016-09-12,Induced magnetism at the interfaces of a Fe/V superlattice investigated by resonant magnetic x-ray scattering,"The induced magnetic moments in the V 3d electronic states of interface
+atomic layers in a Fe(6ML)/V(7ML) superlattice was investigated by x-ray
+resonant magnetic scattering. The first V atomic layer next to Fe was found to
+be strongly antiferromagnetically polarized relatively to Fe and the magnetic
+moments of the next few atomic layers in the interior V region decay
+exponentially with increasing distance from the interface, while the magnetic
+moments of the Fe atomic layers largely remain bulk-like. The induced V moments
+decay more rapidly as observed by x-ray magnetic scattering than in standard
+x-ray magnetic circular dichroism. The theoretical description of the induced
+magnetic atomic layer profile in V was found to strongly rely on the interface
+roughness within the superlattice period. These results provide new insight
+into interface magnetism by taking advantage of the enhanced depth sensitivity
+to the magnetic profile over a certain resonant energy bandwidth in the
+vicinity of the Bragg angles.",1609.03486v1
+2016-12-20,Magnetic fields in turbulent quark matter and magnetar bursts,"We analyze the magnetic field evolution in dense quark matter with unbroken
+chiral symmetry, which can be found inside quark and hybrid stars. The magnetic
+field evolves owing to the chiral magnetic effect in the presence of the
+electroweak interaction between quarks. In our study, we also take into account
+the magnetohydrodynamic turbulence effects in dense quark matter. We derive the
+kinetic equations for the spectra of the magnetic helicity density and the
+magnetic energy density as well as for the chiral imbalances. On the basis of
+the numerical solution of these equations, we find that turbulence effects are
+important for the behavior of small scale magnetic fields. It is revealed that,
+under certain initial conditions, these magnetic fields behave similarly to the
+electromagnetic flashes of some magnetars. We suggest that fluctuations of
+magnetic fields, described in frames of our model, which are created in the
+central regions of a magnetized compact star, can initiate magnetar bursts.",1612.06540v2
+2017-01-16,Dynamics of magnetic nano particles in a viscous fluid driven by rotating magnetic fields,"The rotational dynamics of magnetic nano particles in rotating magnetic
+fields in the presence of thermal noise is studied both theoretically and by
+performing numerical calculations. Kinetic equations for the dynamics of
+particles with uniaxial magnetic anisotropy are studied and the phase lag
+between the rotating magnetic moment and the driving field is obtained. It is
+shown that for large enough anisotropy energy the magnetic moment is locked to
+the anisotropy axis so that the particle behaves like a rotating magnetic
+dipole. The corresponding rigid dipole model is analyzed both numerically by
+solving the appropriate Fokker-Planck equation and analytically by applying an
+effective field method. In the special case of a rotating magnetic field
+applied analytic results are obtained in perfect agreement with numerical
+results based on the Fokker-Planck equation. The analytic formulas derived are
+not restricted to small magnetic fields or low frequencies and are therefore
+important for applications. The illustrative numerical calculations presented
+are performed for magnetic parameters typical for iron oxide.",1702.04673v1
+2017-07-04,Wigner function and kinetic phenomena for chiral plasma in a strong magnetic field,"By using the exact solutions of the Weyl equation in a constant magnetic
+field, the equal-time Wigner function for magnetized chiral plasma is derived.
+It is found that the dependence of the Wigner function on the component of
+momentum along the magnetic field is asymmetric and is correlated with the
+fermion chirality. Such a dependence is principal for reproducing the correct
+chiral magnetic and chiral separation effects. In the lowest Landau level
+approximation, the equation for the equal-time Wigner function in a strong
+magnetic field is derived. By making use of this equation, it is found that the
+longitudinal collective modes in a strong magnetic field are gapped plasmons
+whose gap is determined by the magnetic field. Unlike the ordinary magnetic
+field, an axial one allows for the dispersion law of the collective excitations
+asymmetric in the wave vector. The thermoelectric phenomena for chiral fermions
+in strong magnetic and axial magnetic fields are studied and the corresponding
+transport coefficients are calculated.",1707.01105v2
+2017-07-14,Insights into the orbital magnetism of noncollinear magnetic systems,"The orbital magnetic moment is usually associated with the relativistic
+spin-orbit interaction, but recently it has been shown that noncollinear
+magnetic structures can also be its driving force. This is important not only
+for magnetic skyrmions, but also for other noncollinear structures, either
+bulk-like or at the nanoscale, with consequences regarding their experimental
+detection. In this work we present a minimal model that contains the effects of
+both the relativistic spin-orbit interaction and of magnetic noncollinearity on
+the orbital magnetism. A hierarchy of models is discussed in a step-by-step
+fashion, highlighting the role of time-reversal symmetry breaking for
+translational and spin and orbital angular motions. Couplings of spin-orbit and
+orbit-orbit type are identified as arising from the magnetic noncollinearity.
+We recover the atomic contribution to the orbital magnetic moment, and a
+nonlocal one due to the presence of circulating bound currents, exploring
+different balances between the kinetic energy, the spin exchange interaction,
+and the relativistic spin-orbit interaction. The connection to the scalar spin
+chirality is examined. The orbital magnetism driven by magnetic noncollinearity
+is mostly unexplored, and the presented model contributes to laying its
+groundwork.",1707.04518v1
+2017-08-11,"Magnetic Charge and Photon Mass: Physical String Singularities, Dirac Condition, and Magnetic Confinement","We find exact, simple solutions to the Proca version of Maxwell's equations
+with magnetic sources. Several properties of these solutions differ from the
+usual case of magnetic charge with a massless photon: (i) the string
+singularities of the usual 3-vector potentials become real singularities in the
+magnetic fields; (ii) the different 3-vector potentials become gauge
+inequivalent and physically distinct solutions; (iii) the magnetic field
+depends on $r$ and $\theta$ and thus is no longer rotationally symmetric; (iv)
+a combined system of electric and magnetic charge carries a field angular
+momentum even when the electric and magnetic charges are located at the same
+place i.e. for dyons); (v) for these dyons one recovers the standard Dirac
+condition despite the photon being massive. We discuss the reason for this. We
+conclude by proposing that the string singularity in the magnetic field of an
+{\it isolated} magnetic charge suggests a confinement mechanism for magnetic
+charge, similar to the flux tube confinement of quarks in QCD.",1708.06229v2
+2017-09-06,Record High Magnetic Anisotropy in Chemically Engineered Iridium Dimer,"Exploring giant magnetic anisotropy in small magnetic nanostructures is of
+both fundamental interest and technological merit for information storage. To
+prevent spin flipping at room temperature due to thermal fluctuation, large
+magnetic anisotropy energy (MAE) over 50 meV in magnetic nanostructure is
+desired for practical applications. We chose one of the smallest magnetic
+nanostructures-Ir2 dimer, to investigate its magnetic properties and explore
+possible approach to engineer the magnetic anisotropy. Through systematic
+first-principles calculations, we found that the Ir2 dimer already possesses
+giant MAE of 77 meV. We proposed an effective way to enhance the MAE of the Ir2
+dimer to 223~294 meV by simply attaching a halogen atom at one end of the Ir-Ir
+bond. The underlying mechanism for the record high MAE is attributed to the
+modification of the energy diagram of the Ir2 dimer by the additional
+halogen-Ir bonding, which alters the spin-orbit coupling Hamiltonian and hence
+the magnetic anisotropy. Our strategy can be generalized to design other
+magnetic molecules or clusters with giant magnetic anisotropy.",1709.01878v1
+2018-01-08,The contribution of magnetic monopoles to ponderomotive forces in plasmas,"It is well--known that when magnetic monopoles are introduced in plasma
+equations the propagation of electromagnetic waves is modified. This occurs
+because of Maxwell equations acquire a symmetrical structure due to the
+existence of electric and magnetic charge current densities. In this work we
+study the nonlinear phenomena of ponderomotive forces associated to the
+presence of magnetic monopoles in a plasma. We generalize the Washimi-Karpman
+result for the ponderomotive force on electric charges to take into account the
+symmetrical form of Maxwell equations in the presence of magnetic charges. It
+is shown that the general ponderomotive force on this plasma depends
+non--trivially on the magnetic monopoles, through the slowly temporal and
+spatial variations of the electromagnetic field amplitudes. The magnetic
+charges introduce corrections even if the plasma is unmagnetized. This last
+force induces a magnetization of the plasma, and therefore a cyclotron
+frequency (proportional to the square of the magnetic charge) is induced for
+electrons. Finally, the magnetic monopoles also experience a ponderomotive
+force due to the electrons. This force accelerates the magnetic charges along
+the direction of propagation of the electromagnetic waves. The possible
+consequences for experimental detection are discussed.",1801.02570v2
+2018-01-17,Magnetic effect on dynamical tide in rapidly rotating astronomical objects,"By numerically solving the equations of rotating magnetohydrodynamics (MHD),
+the magnetic effect on dynamical tide is studied. It is found that magnetic
+field has a significant impact not only on the flow structure, i.e. the
+internal shear layers in rotating flow can be destroyed in the presence of a
+moderate or stronger magnetic field (in the sense that the Alfv\'en velocity is
+at least of the order of 0.1 of the surface rotational velocity), but also on
+the dispersion relation of waves excited by tidal force such that the range of
+tidal resonance is broadened by magnetic field. A major result is that the
+total tidal dissipation scales as square of the field strength, which can be
+used to estimate the strength of internal magnetic field in the astronomical
+object of a binary system. Moreover, with a moderate or stronger field the
+ratio of the magnetic dissipation to the viscous dissipation is almost
+inversely proportional to magnetic Prandtl number (i.e. the ratio of viscosity
+to magnetic diffusivity), and therefore in the astrophysical situation at small
+magnetic Prandtl number magnetic dissipation dominates over viscous dissipation
+with a moderate or stronger field.",1801.05552v2
+2018-02-01,An analytical computation of magnetic field generated from a cylinder ferromagnet,"An analytical formulation to compute a magnetic field generated from an
+uniformly magnetized cylinder ferromagnet is developed. Exact solutions of the
+magnetic field generated from the magnetization pointing in an arbitrary
+direction are derived, which are applicable both inside and outside the
+ferromagnet. The validities of the present formulas are confirmed by comparing
+them with demagnetization coefficients estimated in earlier works. The results
+will be useful for designing practical applications, such as high-density
+magnetic recording and microwave generators, where nanostructured ferromagnets
+are coupled to each other through the dipole interactions and show cooperative
+phenomena such as synchronization. As an example, the magnetic field generated
+from a spin torque oscillator for magnetic recording based on microwave
+assisted magnetization reversal is studied.",1802.00384v1
+2018-02-08,Manipulating Anomalous Hall Antiferromagnets with Magnetic Fields,"The symmetry considerations that imply a non-zero anomalous Hall effect (AHE)
+in certain non-collinear antiferromagnets also imply both non-zero orbital
+magnetization and a net spin magnetization. We have explicitly evaluated the
+orbital magnetizations of several anomalous Hall effect antiferromagnets and
+find that they tend to dominate over spin magnetizations, especially so when
+spin-orbit interactions are weak. Because of the greater relative importance of
+orbital magnetization the coupling between magnetic order and an external
+magnetic field is unusual. We explain how magnetic fields can be used to
+manipulate magnetic configurations in these systems, pointing in particular to
+the important role played by the response of orbital magnetization to the
+Zeeman-like spin exchange fields.",1802.03044v2
+2018-03-01,On Magnetic Inhibition Theory in Non-resistive Magnetohydrodynamic Fluids,"We investigate why the non-slip boundary condition for the velocity, imposed
+in the direction of impressed magnetic fields, can contribute to the magnetic
+inhibition effect based on the nonhomogeneous magnetic Rayleigh--Taylor (abbr.
+NMRT) problem in non-resistive magnetohydrodynamic (abbr. MHD) fluids.
+Exploiting an infinitesimal method in Lagrangian coordinates, the idea of
+(equivalent) magnetic tension, and the differential version of magnetic flux
+conservation, we give an explanation of physical mechanism for the magnetic
+inhibition phenomenon in a non-resistive MHD fluid. Moreover, we find that the
+magnetic energy in the non-resistive MHD fluid depends on the displacement of
+fluid particles, and thus can be regarded as elastic potential energy.
+Motivated by this observation, we further use the well-known minimum potential
+energy principle to explain the physical meaning of the stability/instability
+criteria in the NMRT problem. As a result of the analysis, we further extend
+the results on the NMRT problem to the stratified MHD fluid case. We point out
+that our magnetic inhibition theory can be used to explain the inhibition
+phenomenon of other instabilities, such as thermal instability, magnetic
+buoyancy instability, and so on, by impressed magnetic fields in non-resistive
+MHD fluids.",1803.00307v2
+2018-04-13,Standing wave approach in the theory of x-ray magnetic reflectivity,"We have developed the extension of the exact x-ray resonant magnetic
+reflectivity theory taking into account the small value of the magnetic terms
+in the x-ray susceptibility tensor. We have shown that squared standing waves
+(forth powder of the total electric field module) determine the output of the
+magnetic addition to the total reflectivity from a magnetic multilayer. The
+approach gives the easily understandable results especially for the
+reflectivity part with the rotated polarization and the obtained relationship
+can essentially speed up the calculation of the asymmetry ratio of the magnetic
+reflectivity relative the sign of the circular polarization in the incident
+radiation. The connection of the magnetic contribution with the standing wave
+structure in the magnetic multilayer means that the magnetic reflectivity with
+rotated polarization possesses higher sensitivity to the depth profiles of
+magnetization and magnetic elements depth distribution than the secondary
+radiation registration at the specular reflection condition.",1804.05104v1
+2018-04-27,Excitation and coherent control of magnetization dynamics in magnetic tunnel junctions using acoustic pulses,"We experimentally study magnetization dynamics in magnetic tunnel junctions
+driven by femtosecond-laser-induced surface acoustic waves. The acoustic pulses
+induce a magnetization precession in the free layer of the magnetic tunnel
+junction through magnetoelastic coupling. The frequency and amplitude of the
+precession shows a pronounced dependence on the applied magnetic field and the
+laser excitation position. Comparing the acoustic-wave-induced precession
+frequencies with precession induced by charge currents and with micromagnetic
+simulations we identify spatially non-uniform magnetization modes localized
+close the edge regions as being responsible for the optically induced
+magnetization dynamics. The experimental scheme even allows us to coherently
+control the magnetization precession using two acoustic pulses. This might
+prove important for future applications requiring ultrafast spin manipulation.
+Additionally, our results directly pinpoint the importance of acoustic pulses
+since they could be relevant when investigating optically-induced temperature
+effects in magnetic structures.",1804.10503v1
+2018-05-10,Magnetic field mediated conductance oscillation in graphene p-n junctions,"The electronic transport of graphene p-n junctions under perpendicular
+magnetic field is investigated in theory. Under low magnetic field, the
+transport is determined by the resonant tunneling of Landau levels and
+conductance versus magnetic field shows a Shubnikov-de Haas oscillation. At
+higher magnetic field, the p-n junction subjected to the quasi-classical regime
+and the formation of snake states results in periodical backscattering and
+transmission as magnetic field varies. The conductance oscillation pattern is
+mediated both by magnetic field and the carrier concentration on bipolar
+regions. For medium magnetic field between above two regimes, the combined
+contributions of resonant tunneling, snake states oscillation and Aharanov-Bohm
+interference induce irregular oscillation of conductance. At very high magnetic
+field, the system is subjected to quantum Hall regime. Under disorder, the
+quantum tunneling at low magnetic field is slightly affected and the
+oscillation of snake states at higher magnetic field is suppressed. In the
+quantum Hall regime, the conductance is a constant as predicted by the mixture
+rule.",1805.03859v1
+2018-05-30,Nonequilibrium Magnetic Oscillation with Cylindrical Vector Beams,"Magnetic oscillation is a generic property of electronic conductors under
+magnetic fields and widely appreciated as a useful probe of their electronic
+band structure, i.e., the Fermi surface geometry. However, the usage of the
+strong static magnetic field makes the measurement insensitive to the magnetic
+order of the target material. That is, the magnetic order is anyhow turned into
+a forced ferromagnetic one. Here we theoretically propose an experimental
+method of measuring the magnetic oscillation in a magnetic-order-resolved way
+by using the azimuthal cylindrical vector (CV) beam, an example of topological
+lightwaves. The azimuthal CV beam is unique in that when focused tightly, it
+develops a pure longitudinal magnetic field. We argue that this characteristic
+focusing property and the discrepancy in the relaxation timescale between
+conduction electrons and localized magnetic moments allow us to develop the
+nonequilibrium analog of the magnetic oscillation measurement. Our optical
+method would be also applicable to metals the under ultra-high pressure of
+diamond anvil cells.",1805.11831v2
+2018-06-15,The turbulent pressure of magnetoconvection for slow and rapid rotation,"Motivated by recent simulations of sunspot formation, we extend the theory of
+the pressure difference between magnetized and non-magnetized gas by Dicke to
+include rotating turbulence. While the (vertical) background field provides a
+positive-definite magnetic pressure difference between the magnetized and the
+unmagnetized gas, Reynolds stress and Maxwell stress of turbulence strongly
+modify this result. With the quasilinear approximation we demonstrate that the
+influence of the turbulence differs between the high-conductivity and the
+low-conductivity limits. Sufficiently small magnetic Reynolds numbers lead to
+magnetic pressure suppression where indeed the pressure excess can even assume
+negative values. Box simulations of magnetoconvection subject to a vertical
+magnetic field carried out with the Nirvana code confirm this overall picture.
+They also demonstrate how a global rotation {\em reduces} the negative magnetic
+pressure effect. For rapid rotation the total magnetic pressure difference
+caused by large-scale magnetic fields { and} turbulence even fully disappears
+for small field strengths. Magnetic fields of moderate strength thus neither
+reduce nor enhance the turbulence pressure of rapidly rotating convection.
+Consequences of this phenomenon for the star formation efficiency are shortly
+discussed.",1806.05877v1
+2018-08-22,Invariants of magnetic Laplacians on periodic graphs,"We consider a magnetic Laplacian with periodic magnetic potentials on
+periodic discrete graphs. Its spectrum consists of a finite number of bands,
+where degenerate bands are eigenvalues of infinite multiplicity. We obtain a
+specific decomposition of the magnetic Laplacian into a direct integral in
+terms of minimal forms. A minimal form is a periodic function defined on edges
+of the periodic graph with a minimal support on the period. It is crucial that
+fiber magnetic Laplacians (matrices) have the minimal number of coefficients
+depending on the quasimomentum and the minimal number of coefficients depending
+on the magnetic potential. We show that these numbers are invariants for the
+magnetic Laplacians on periodic graphs. Using this decomposition, we estimate
+the position of each band, the Lebesgue measure of the magnetic Laplacian
+spectrum and a variation of the spectrum under a perturbation by a magnetic
+field in terms of these invariants and minimal forms. In addition, we consider
+an inverse problem: we determine necessary and sufficient conditions for
+matrices depending on the quasimomentum on a finite graph to be fiber magnetic
+Laplacians. Moreover, similar results for magnetic Schr\""odinger operators with
+periodic potentials are obtained.",1808.07762v1
+2018-10-25,Magnetic force sensing using a self-assembled nanowire,"We present a scanning magnetic force sensor based on an individual
+magnet-tipped GaAs nanowire (NW) grown by molecular beam epitaxy. Its magnetic
+tip consists of a final segment of single-crystal MnAs formed by sequential
+crystallization of the liquid Ga catalyst droplet. We characterize the
+mechanical and magnetic properties of such NWs by measuring their flexural
+mechanical response in an applied magnetic field. Comparison with numerical
+simulations allows the identification of their equilibrium magnetization
+configurations, which in some cases include magnetic vortices. To determine a
+NW's performance as a magnetic scanning probe, we measure its response to the
+field profile of a lithographically patterned current-carrying wire. The NWs'
+tiny tips and their high force sensitivity make them promising for imaging weak
+magnetic field patterns on the nanometer-scale, as required for mapping
+mesoscopic transport and spin textures or in nanometer-scale magnetic
+resonance.",1810.10865v1
+2018-12-25,Magnetic Monopoles and Dark Matter,"Schwinger's idea about the magnetic world of the early Universe, in which
+magnetic charges (monopoles) and magnetic atoms (g$^{+}$g$^{-}$) could be
+formed, is developed. In the present-day Universe magnetic charges with
+energies in the GeV range can be formed in the magnetospheres of young pulsars
+in super strong magnetic fields. Spectroscopic features of magnetic atoms and
+possibilities for their observations are discussed. Relic magnetic atoms can
+contribute up to 18% to the dark matter density. The gamma-ray excess at our
+Galactic center could arise under two-photon annihilation of magnetic charges
+as a cooperative effect from neutron stars. A sharp physical difference of
+Schwinger's magnetic world from Dirac's present-day electric world is pointed
+out. Artificial magnetic monopoles are also mentioned briefly.",1901.02341v1
+2019-01-10,Ultrafast magnetization dynamics in uniaxial ferrimagnets with compensation point. GdFeCo,"We derive an effective Lagrangian in the quasi-antiferromagnetic
+approximation that allows to describe the magnetization dynamics for uniaxial
+f-d (rare-earth - transition metal) ferrimagnet near the magnetization
+compensation point in the presence of external magnetic field. We perform
+calculations for the parameters of GdFeCo, a metallic ferrimagnet with
+compensation point that is one of the most promising materials in ultrafast
+magnetism. Using the developed approach, we find the torque that acts on the
+magnetization due to ultrafast demagnetization pulse that can be caused either
+by ultrashort laser or electrical current pulse. We show that the torque is
+non-zero only in the non-collinear magnetic phase that can be acquired by
+applying external magnetic field to the material. The coherent response of
+magnetization dynamics amplitude and its timescale exhibits critical behavior
+near certain values of the magnetic field corresponding to a spin-flop like
+phase transition. Understanding the underlying mechanisms for these effects
+opens the way to efficient control of the amplitude and the timescales of the
+spin dynamics, which is one of the central problems in the field of ultrafast
+magnetism.",1901.03072v2
+2019-02-21,Self-induced Magnetic Flux Structure in the Magnetic Superconductor RbEuFe$_4$As$_4$,"We report an unusual enhancement of the magnetic induction in single crystals
+of the magnetic superconductor RbEuFe$_4$As$_4$ , highlighting the interplay
+between superconducting and magnetic subsystems in this material. Contrary to
+the conventional Meissner expulsion of magnetic flux below the superconducting
+transition temperature, we observe a substantial boost of the magnetic flux
+density upon approaching the magnetic transition temperature, Tm. Direct
+imaging of the flux evolution with a magneto-optical technique, shows that the
+magnetic subsystem serves as an internal magnetic flux pump, drawing Abrikosov
+vortices from the surface, while the superconducting subsystem controls their
+conveyance into the bulk of the magnetic superconductor via a peculiar
+self-organized critical state.",1902.08125v1
+2019-03-11,Spin-glass state and reversed magnetic anisotropy induced by Cr doping in the Kitaev magnet $α$-RuCl$_3$,"Magnetic properties of the substitution series Ru$_{1-x}$Cr$_x$Cl$_3$ were
+investigated to determine the evolution from the anisotropic Kitaev magnet
+$\alpha$-RuCl$_3$ with $J_{\rm eff} = 1/2$ magnetic Ru$^{3+}$ ions to the
+isotropic Heisenberg magnet CrCl$_3$ with $S = 3/2$ magnetic Cr$^{3+}$ ions.
+Magnetization measurements on single crystals revealed a reversal of the
+magnetic anisotropy under doping, which we argue to arise from the competition
+between anisotropic Kitaev and off-diagonal interactions on the Ru-Ru links and
+approximately isotropic Cr-Ru and isotropic Cr-Cr interactions. In addition,
+combined magnetization, ac susceptibility and specific-heat measurements
+clearly show the destabilization of the long-range magnetic order of
+$\alpha$-RuCl$_3$ in favor of a spin-glass state of Ru$_{1-x}$Cr$_x$Cl$_3$ for
+a low doping of $x\backsimeq0.1$. The corresponding freezing temperature as a
+function of Cr content shows a broad maximum around $x\backsimeq0.45$.",1903.04248v3
+2019-03-26,Dynamical evolution of magnetic fields in the intracluster medium,"We investigate the evolution of magnetic fields in galaxy clusters starting
+from constant primordial fields using highly resolved ($\approx \rm 4 ~kpc$)
+cosmological MHD simulations. The magnetic fields in our sample exhibit
+amplification via a small-scale dynamo and compression during structure
+formation. In particular, we study how the spectral properties of magnetic
+fields are affected by mergers, and we relate the measured magnetic energy
+spectra to the dynamical evolution of the intracluster medium. The magnetic
+energy grows by a factor of $\sim$ 40-50 in a time-span of $\sim 9$ Gyr and
+equipartition between kinetic and magnetic energy occurs on a range of scales
+($< 160 \rm ~kpc$ at all epochs) depending on the turbulence state of the
+system. We also find that, in general, the outer scale of the magnetic field
+and the MHD scale are not simply correlated in time. The effect of major
+mergers is to shift the peak magnetic spectra to it smaller scales, whereas the
+magnetic amplification only starts after $\lesssim$ 1 Gyr. In contrast,
+continuous minor mergers promote the steady growth of the magnetic field. We
+discuss the implications of these findings in the interpretation of future
+radio observations of galaxy clusters.",1903.11052v1
+2019-04-22,Strain-Induced Reversible Manipulation of Orbital Magnetic Moments in Ni/Cu Multilayers on Ferroelectric BaTiO3,"Controlling magnetic anisotropy by orbital magnetic moments related to
+interfacial strains has considerable potential for the development of future
+devices using spins and orbitals. For the fundamental physics, the relationship
+between strain and orbital magnetic moment is still unknown, because there are
+few tools to probe changes of orbital magnetic moment. In this study, we
+developed an electric-field- (E)-induced X-ray magnetic circular dichroism
+(EXMCD) technique to apply E to a ferroelectric BaTiO3 substrate. We reversibly
+tuned the interfacial lattice constants of Ni/Cu multilayers on BaTiO3 using
+this technique. As the domain structures in BaTiO3 are modulated by E, EXMCD
+measurements reveal that the changes in the magnetic anisotropy of Ni/Cu films
+are induced through the modulation of orbital magnetic moments in Ni with
+magneto-elastic contributions. The strained Ni layer that induces the
+perpendicular magnetic anisotropy without E is released at E = 8 kV/cm, and
+in-plane magnetization also occurs. We observed that EXMCD measurements
+clarified the origin of the reversible changes in perpendicular magnetic
+anisotropy and established the relationship between macroscopic inverse
+magnetostriction effects and microscopic orbital moment anisotropy.",1904.09719v1
+2019-04-25,Magnetic-field-induced quantized anomalous Hall effect in intrinsic magnetic topological insulator MnBi$_2$Te$_4$,"In a magnetic topological insulator, nontrivial band topology conspires with
+magnetic order to produce exotic states of matter that are best exemplified by
+quantum anomalous Hall (QAH) insulators and axion insulators. Up till now, such
+magnetic topological insulators are obtained by doping topological insulators
+with magnetic atoms. The random magnetic dopants, however, inevitably introduce
+disorders that hinder further exploration of quantum effects in the material.
+Here, we resolve this dilemma by probing quantum transport in MnBi$_2$Te$_4$
+thin flake - a topological insulator with intrinsic magnetic order. In this
+layered van der Waals crystal, the ferromagnetic layers couple anti-parallel to
+each other, so MnBi$_2$Te$_4$ is an antiferromagnet. A magnetic field, however,
+aligns all the layers and induces an interlayer ferromagnetic order; we show
+that a quantized anomalous Hall response emerges in atomically thin
+MnBi$_2$Te$_4$ under a moderate magnetic field. MnBi$_2$Te$_4$ therefore
+becomes the first intrinsic magnetic topological insulator exhibiting quantized
+anomalous Hall effect. The result establishes MnBi$_2$Te$_4$ as an ideal arena
+for further exploring various topological phenomena.",1904.11468v1
+2019-05-22,Reduced Exchange Interactions in Magnetic Tunnel Junction Free Layers with Insertion Layers,"Perpendicularly magnetized CoFeB layers with ultra-thin non-magnetic
+insertion layers are very widely used as the electrodes in magnetic tunnel
+junctions for spin transfer magnetic random access memory devices. Exchange
+interactions play a critical role in determining the thermal stability of
+magnetic states in such devices and their spin torque switching efficiency.
+Here the exchange constant of free layers incorporated in full magnetic tunnel
+junction layer stacks, specifically CoFeB free layers with W insertion layers
+is determined by magnetization measurements in a broad temperature range. A
+significant finding is that the exchange constant decreases significantly and
+abruptly with W insertion layer thickness. The perpendicular magnetic
+anisotropy shows the opposite trend; it initially increases with W insertion
+layer thickness and shows a broad maximum for approximately one monolayer (0.3
+nm) of W. These results highlight the interdependencies of magnetic
+characteristics required to optimize the performance of magnetic tunnel
+junction devices.",1905.09329v1
+2019-07-24,Electron doping induced magnetic glassy state in phase separated YBaCo$_2$O$_{5.5-δ}$,"The structural, magnetic and transport properties of the layered
+RBaCo$_2$O$_{5.5}$ cobaltites are sensitive to the oxygen stoichiometry. In
+this present study, we report the presence of a low-temperature magnetic glassy
+state in electron-doped polycrystalline YBaCo$_2$O$_{5.5}$ cobaltite. The ac
+magnetization studies show the absence of conventional spin glass features,
+while the various dc magnetization studies demonstrate the presence of
+non-equilibrium magnetic glassy state at low temperature. The magnetic glassy
+state of this sample results from the kinetic arrest of the first order ferro
+(or ferri) to antiferromagnetic transition. The role of electron doping in the
+occurrence of magnetic glassy phenomena is discussed in terms of magnetic phase
+separation involving the Co3+/Co2+ clusters of the ferrimagnetic phase in the
+Co3+/Co3+ antiferromagnetic matrix.",1907.10248v1
+2019-08-27,Effect of Magnetisation of Bulk Superconductors on Permanent Magnets for Reversible Braking Applications,"Magnetisation of superconductors are often measured under isothermal and
+uniform magnetic fields. Magnetisation measurements in an unrestricted
+thermodynamic state and in non uniform magnetic fields naturally emerge from
+permanent magnets in comparison with size of superconducting bulk are needed
+for practical applications. A stationary Type II superconductor bulk sample is
+magnetised (FC and ZFC) at liquid nitrogen temperatures in the presence of a
+stationary permanent magnet. Magnetic field produced by magnetised
+superconductor and permanent magnet as a function of distance are measured
+along a straight line, a supposed path of another moving permanent magnet. A
+moving magnet is introduced and moved along the same straight line. Force
+acting on moving magnet as a function of distance are measured due to
+magnetisation in superconductor and stationary magnet. Both field and force
+measurements are quasi static. These experimental results combined with
+simulation results show insight in to the transfer of energy stored in
+magnetisation to thermal energy and the effect of rate of this energy transfer
+in AC response of superconductors which are otherwise not possible with
+isothermal studies. A possible application of reversible braking with bulk
+superconductors for motors and generators is explored. Future similar
+measurements with Type I superconductor would provide more insights in to this
+study.",1908.10297v1
+2019-09-26,Coherent charge and magnetic ordering in Ho/Y superlattice revealed by element-selective x-ray scattering,"Magnetic rare-earth / non-magnetic metal superlattices are well-known to
+display chiral spin helices in the rare-earth layers that propagate coherently
+across the non-magnetic layers. However, the underlying mechanism that
+preserves the magnetic phase and chirality coherence across the non-magnetic
+layers has remained elusive. In this Letter, we use resonant and
+element-specific x-ray scattering to evidence directly the formation of two
+fundamentally different long-range modulations in a Holmium/Yttrium (Ho/Y)
+multilayer: the known Ho chiral spin helix with periodicity 25 {\AA}, and a
+newly observed charge density wave with periodicity 16 {\AA} that propagates
+through both the Ho and non-magnetic Y layer. With x-ray circular magnetic
+dichroism measurements ruling out the existence of a magnetic proximity effect
+induced moment in the non-magnetic Y layers, we propose that the charge density
+wave is also chiral, thus providing the means for the transmittance of magnetic
+chirality coherence between Ho layers.",1909.12372v2
+2019-11-05,Analysis of magnetization induced error field in superconducting magnets,"The field error due to magnetization of superconductors in a superconducting
+magnet can significantly compromise the field homogeneity which is extremely
+important for NMR magnets. This is especially true for high Tc superconducting
+magnets. In this paper, the error field induced by the magnetization of
+superconducting wires or tapes is analyzed using a magnetic dipole field model.
+It uses experimentally measured magnetization of superconducting wires, and
+eludes the need of assuming screening current and its distribution as in
+previous methods. The field error of a REBCO coil calculated by this model and
+by a screening current model shows complete agreement. A few cases of field
+error distribution along the coil axis are calculated. The results are in
+qualitative agreement with experiments in the literature. This model would be
+particularly useful for magnets wound by multifilamentary wires or tapes where
+the filament sizes vary and filament bridging may occur hence screening current
+distribution is unknown. This model can also be used as a base for numerical
+calculations of the field error of a large practical magnet.",1911.02139v1
+2019-11-18,Anisotropic magnetic properties of trigonal ErAl$_2$Ge$_2$ single crystal,"We report the anisotropic magnetic properties of the ternary compound
+ErAl$_2$Ge$_2$. Single crystals of this compound were grown by high temperature
+solution growth technique,using Al:Ge eutectic composition as flux. From the
+powder x-ray diffraction we confirmed that ErAl$_2$Ge$_2$ crystallizes in the
+trigonal CaAl$_2$Si$_2$-type crystal structure. The anisotropic magnetic
+properties of a single crystal were investigated by measuring the magnetic
+susceptibility, magnetization, heat capacity and electrical resistivity. A bulk
+magnetic ordering occurs around 4 K inferred from the magnetic susceptibility
+and the heat capacity. The magnetization measured along the $ab$-plane
+increases more rapidly than along the $c$-axis suggesting the basal $ab$-plane
+as the easy plane of magnetization. The magnetic susceptibility, magnetization
+and the $4f$-derived part of the heat capacity in the paramagnetic regime
+analysed based on the point charge model of the crystalline electric field
+(CEF) indicate a relatively low CEF energy level splitting.",1911.07589v1
+2019-12-03,Nanoscale Tantalum Layer Controlling the Magnetic Coupling between Two Ferromagnetic Electrodes via Insulator of a Magnetic Tunnel Junction,"Ability to tailor the nature of the magnetic coupling between two
+ferromagnetic electrodes can enable the realization of new spintronics device
+systems. This paper discusses our finding that deposition of an ultrathin
+tantalum (Ta) on the NiFe top electrode reversed the nature of
+inter-ferromagnetic electrode coupling. We observed that the deposition of ~ 5
+nm Ta on the top of a magnetic tunnel junction with Ta( 2 nm)/Co(5 nm)/NiFe (5
+nm)/AlOx( 2 nm)/NiFe (10-15 nm) configuration changed the magnetic coupling
+between two ferromagnetic electrodes from antiferromagnetic to ferromagnetic.
+We investigated Ta effect using multiple magnetic characterizations like
+ferromagnetic resonance, magnetometry, and polarized neutron reflectometry.
+Ferromagnetic resonance characterization was very sensitive for detecting the
+changes in magnetic coupling via the insulating spacer. This simple approach of
+adding Ta film to alter the magnetic coupling can impact the other burgeoning
+areas like molecular spintronics. We found that preexisting magnetic coupling
+between two ferromagnetic electrodes impacted the resultant magnetic properties
+of magnetic tunnel junctions based molecular spintronics devices.",1912.01331v1
+2019-12-16,3D printing of polymer-bonded anisotropic magnets in an external magnetic field and by a modified production process,"The possibility of producing polymer-bonded magnets with the aid of additive
+processes, such as 3D printing, opens up a multitude of new areas of
+application. Almost any structures and prototypes can be produced
+cost-effectively in small quantities. Extending the 3D printing process allows
+the manufacturing of anisotropic magnetic structures by aligning the magnetic
+easy axis of ferromagnetic particles inside a paste-like compound material
+along an external magnetic field. This is achieved by two different approaches:
+First, the magnetic field for aligning the particles is provided by a permanent
+magnet. Secondly, the 3D printing process itselfs generates an anisotropic
+behavior of the structures. An inexpensive and customizable end-user fused
+filament fabrication 3D printer is used to print the magnetic samples. The
+magnetical properties of different magnetic anisotropic Sr ferrite and SmFeN
+materials are investigated and discussed.",1912.07374v1
+2019-12-29,Stabilizing effect of magnetic helicity on magnetic cavities in the intergalactic medium,"We investigate the effect of magnetic helicity on the stability of buoyant
+magnetic cavities as found in the intergalactic medium. In these cavities, we
+insert helical magnetic fields and test whether or not helicity can increase
+their stability to shredding through the Kelvin-Helmholtz instability and, with
+that, their lifetime. This is compared to the case of an external vertical
+magnetic field which is known to reduce the growth rate of the Kelvin-Helmholtz
+instability. By comparing a low-helicity configuration with a high helicity one
+with the same magnetic energy we find that an internal helical magnetic field
+stabilizes the cavity. This effect increases as we increase the helicity
+content. Stabilizing the cavity with an external magnetic field requires
+instead a significantly stronger field at higher magnetic energy. We conclude
+that the presence of helical magnetic fields is a viable mechanism to explain
+the stability of intergalactic cavities on time scales longer than 100 Myr.",1912.12723v3
+2020-01-09,Two-dimensional magnetic nanoelectromechanical resonators,"Two-dimensional (2D) layered materials possess outstanding mechanical,
+electronic and optical properties, making them ideal materials for
+nanoelectromechanical applications. The recent discovery of 2D magnetic
+materials has promised a new class of magnetically active nanoelectromechanical
+systems (NEMS). Here we demonstrate resonators made of 2D CrI3, whose
+mechanical resonances depend on the magnetic state of the material. We quantify
+the underlining effects of exchange and anisotropy magnetostriction by
+measuring the field dependence of the resonance frequency under a magnetic
+field parallel and perpendicular to the easy axis, respectively. Furthermore,
+we show efficient strain tuning of magnetism in 2D CrI3 as a result of the
+inverse magnetostrictive effect using the NEMS platform. Our results establish
+the basis for mechanical detection of magnetism and magnetic phase transitions
+in 2D layered magnetic materials. The new magnetic NEMS may also find
+applications in magnetic actuation and sensing.",2001.03153v1
+2020-01-27,Non-exponential magnetic relaxation in magnetic nanoparticles for hyperthermia,"Magnetic nanoparticle based hyperthermia emerged as a potential tool for
+treating malignant tumours. The efficiency of the method relies on the
+knowledge of magnetic properties of the samples; in particular, knowledge of
+the frequency dependent complex magnetic susceptibility is vital to optimize
+the irradiation conditions and to provide feedback for material science
+developments. We study the frequency-dependent magnetic susceptibility of an
+aqueous ferrite suspension for the first time using non-resonant and resonant
+radiofrequency reflectometry. We identify the optimal measurement conditions
+using a standard solenoid coil, which is capable of providing the complex
+magnetic susceptibility up to 150 MHz. The result matches those obtained from a
+radiofrequency resonator for a few discrete frequencies. The agreement between
+the two different methods validates our approach. Surprisingly, the dynamic
+magnetic susceptibility cannot be explained by an exponential magnetic
+relaxation behavior even when we consider a particle size-dependent
+distribution of the relaxation parameter.",2001.09774v1
+2020-02-25,Noncollinear magnetic structure and magnetoelectric coupling in buckled honeycomb Co$_4$Nb$_2$O$_9$:A single crystal neutron diffraction study,"Through analysis of single crystal neutron diffraction data, we present the
+magnetic structures of magnetoelectric Co4Nb2O9 under various magnetic fields.
+In zero-field, neutron diffraction experiments below TN=27 K reveal that the
+Co2+ moments order primarily along the a* direction without any spin canting
+along the c axis, manifested by the magnetic symmetry C2/c'. The moments of
+nearest neighbor Co atoms order ferromagnetically with a small cant away from
+the next nearest neighbor Co moments along the c axis. In the applied magnetic
+field H//a, three magnetic domains were aligned with their major magnetic
+moments perpendicular to the magnetic field with no indication of magnetic
+phase transitions. The influences of magnetic fields on the magnetic structures
+associated with the observed magnetoelectric coupling are discussed.",2002.10599v1
+2020-03-18,Thermally induced generation and annihilation of magnetic chiral skyrmion bubbles and achiral bubbles in Mn-Ni-Ga Magnets,"Magnetic chiral skyrmion bubbles and achiral bubbles are two independent
+magnetic domain structures, in which the former with equivalent winding number
+to skyrmions offers great promise as information carriers for further
+spintronic devices. Here, in this work, we experimentally investigate the
+generation and annihilation of magnetic chiral skyrmion bubbles and achiral
+bubbles in the Mn-Ni-Ga thin plate by using the Lorentz transmission electron
+microscopy (L-TEM). The two independent magnetic domain structures can be
+directly controlled after the field cooling manipulation by varying the titled
+angles of external magnetic fields. By imaging the magnetization reversal with
+increasing temperature, we found an extraordinary annihilation mode of magnetic
+chiral skyrmion bubbles and a non-linear frequency for the winding number
+reversal. Quantitative analysis of such dynamics was performed by using L-TEM
+to directly determine the barrier energy for the magnetization reversal of
+magnetic chiral skyrmion bubbles.",2003.08035v1
+2020-03-22,Magnetization steps in the molecular magnet Ni$_4$Mo$_{12}$ revealed by complex exchange bridges,"We study the behavior of the magnetization and the magnetic susceptibility of
+molecular magnets with complex bridging structure. Our computations are based
+on a post-Hartree-Fock method accounting for the intricate network of
+interatomic bonds and an effective spin-like Hamiltonian that captures the
+essential magnetic features of magnetic molecules. The devised method and the
+constructed Hamiltonian are further employed to characterize the magnetic
+properties of the molecular magnet Ni$_4$Mo$_{12}$. The obtained results
+reproduce both quantitatively and qualitatively the main features of the
+magnetic spectrum. Furthermore, the computations for the magnetization and the
+low-field susceptibility are in very good agreement with their experimental
+counterparts. In this respect, they improve upon the results obtained with
+conventional Heisenberg models.",2003.12475v1
+2020-07-24,Can the dynamics of test particles around charged stringy black holes mimic the spin of Kerr black holes?,"We study the motion of electrically charged particles, magnetic monopoles,
+and magnetic dipoles around electrically and magnetically charged stringy black
+holes. From the analysis of the radius of the innermost stable circular orbit
+(ISCO) of electrically charged particles, we show that the electric charge $Q$
+of stringy black holes can mimic well the spin of Kerr black holes; the black
+hole magnetic charge $Q_m$ can mimic spins up to $a_* \simeq 0.85$ for magnetic
+dipoles; the magnetic charge parameter $g$ of a magnetic monopole can mimic
+spins up to $a_* \simeq 0.8$. This is due to the destructive character of the
+magnetic field and such a result excludes the existence of an appreciable black
+hole magnetic charge in astrophysical black holes from the observation of
+rapidly rotating objects with dimensionless spin up to $a_* \simeq 0.99$. We
+then consider the magnetar SGR (PSR) J1745-2900 as a magnetic dipole orbiting
+the supermassive black hole Sagittarius A* (Sgr A*). We show that Sgr A* may be
+interpreted as a stringy black hole with magnetic charge $Q_{\rm m}/M \leq
+0.4118$.",2007.12462v1
+2020-07-28,Magnetic bubbles in an M-type hexagonal ferrite observed by hollow-cone Foucault imaging and small-angle electron diffraction,"We report hollow-cone imaging and small-angle electron diffraction of
+nanoscale magnetic textures such as magnetic-striped domains and magnetic
+bubbles of M-type hexagonal ferrite
+BaFe$_{10.35}$Sc$_{1.6}$Mg$_{0.05}$O$_{19}$. The advantage of the hollow-cone
+Foucault method is that magnetic domains with various directions of
+magnetization can be visualized under an infocus condition. Moreover, the
+contrast of magnetic domain walls in magnetic bubbles depends on the
+inclination angle of the illumination beam. The combination of small-angle
+electron diffraction and hollow-cone Foucault imaging proves that magnetization
+at domain walls exhibits in-plane directions in the magnetic-striped domains
+and magnetic bubbles.",2007.13994v1
+2020-08-04,Magnetism and anomalous transport in the Weyl semimetal PrAlGe: Possible route to axial gauge fields,"In magnetic Weyl semimetals, where magnetism breaks time-reversal symmetry,
+large magnetically sensitive anomalous transport responses are anticipated that
+could be useful for topological spintronics. The identification of new magnetic
+Weyl semimetals is therefore in high demand, particularly since in these
+systems Weyl node configurations may be easily modified using magnetic fields.
+Here we explore experimentally the magnetic semimetal PrAlGe, and unveil a
+direct correspondence between easy-axis Pr ferromagnetism and anomalous Hall
+and Nernst effects. With sizes of both the anomalous Hall conductivity and
+Nernst effect in good quantitative agreement with first principles
+calculations, we identify PrAlGe as a system where magnetic fields can connect
+directly to Weyl nodes via the Pr magnetization. Furthermore, we find the
+predominantly easy-axis ferromagnetic ground state co-exists with a low density
+of nanoscale textured magnetic domain walls. We describe how such nanoscale
+magnetic textures could serve as a local platform for tunable axial gauge
+fields of Weyl fermions.",2008.01476v1
+2020-09-14,Calculation of permanent magnet arrangements for stellarators: A linear least-squares method,"A problem arising in several engineering areas is to design magnets outside a
+volume that produce a desired magnetic field inside it. One instance of this
+problem is stellarator design, where it has recently been shown that permanent
+magnets can provide the required shaping of the magnetic field. Here we
+demonstrate a robust and efficient algorithm REGCOIL_PM to calculate the
+spatial distribution of these permanent magnets. The procedure involves a small
+number of fixed-point iterations, with a linear least-squares problem solved at
+each step. The method exploits the Biot-Savart Law's exact linearity in
+magnetization density and approximate linearity in magnet size, for magnets far
+from the target region. No constraint is placed on the direction of
+magnetization, so Halbach solutions are found naturally, and the magnitude of
+the magnetization can be made uniformly equal to a target value.",2009.06535v1
+2020-09-24,Magnetic Field Induced Phase Transition in Spinel GeNi2O4,"Cubic spinel GeNi2O4 exhibits intriguing magnetic properties with two
+successive antiferromagnetic phase transitions (TN1 12.1 and TN2 11.4 K) with
+the absence of any structural transition. We have performed detailed heat
+capacity and magnetic measurements in different crystallographic orientations.
+A new magnetic phase in presence of magnetic field (H > 4 T) along the [111]
+direction is revealed, which is not observed when the magnetic field is applied
+along the [100] and [110] directions. High field neutron powder diffraction
+measurements confirm such a change in magnetic phase, which could be ascribed
+to a spin reorientation in the presence of magnetic field. A strong magnetic
+anisotropy and competing magnetic interactions play a crucial role on the
+complex magnetic behavior in this cubic system.",2009.11960v1
+2020-10-06,An ultra-stable 1.5 tesla permanent magnet assembly for qubit experiments at cryogenic temperatures,"Magnetic fields are a standard tool in the toolbox of every physicist, and
+are required for the characterization of materials, as well as the polarization
+of spins in nuclear magnetic resonance or electron paramagnetic resonance
+experiments. Quite often a static magnetic field of sufficiently large, but
+fixed magnitude is suitable for these tasks. Here we present a permanent magnet
+assembly that can achieve magnetic field strengths of up to 1.5T over an air
+gap length of 7mm. The assembly is based on a Halbach array of neodymium
+(NdFeB) magnets, with the inclusion of the soft magnetic material Supermendur
+to boost the magnetic field strength inside the air gap. We present the design,
+simulation and characterization of the permanent magnet assembly, measuring an
+outstanding magnetic field stability with a drift rate of |D| < 2.8 ppb/h. Our
+measurements demonstrate that this assembly can be used for spin qubit
+experiments inside a dilution refrigerator, successfully replacing the more
+expensive and bulky superconducting solenoids.",2010.02455v2
+2020-10-10,Dynamics of charged and magnetized particles around cylindrical black holes immersed in external magnetic field,"This paper investigates the motion and acceleration of a particle that is
+electrically and magnetically charged, which rotates around a cylindrical black
+hole in the presence of an external asymptotically uniform magnetic field
+parallel to the z axis. Basically, the work considers the circular orbits of
+particles rotating around the central object and studies the dependence of the
+most internal stable circular orbits (ISCO) on the so-called magnetic coupling
+parameters, which are responsible for the interaction between the external
+magnetic field and magnetized and charged particles. It is also shown that the
+ISCO radius decreases with increasing magnetized parameter. Therefore,
+collisions of magnetized particles around a cylindrical black hole immersed in
+an external magnetic field were also studied, and it was shown that the
+magnetic field can act as a particle accelerator around non-rotating
+cylindrical black holes.",2010.04969v1
+2020-10-30,Characterization of microscopic ferromagnetic defects in thin films using magnetic microscope based on Nitrogen-Vacancy centres,"In this work we present results acquired by applying magnetic field imaging
+technique based on Nitrogen-Vacancy centres in diamond crystal for
+characterization of magnetic thin films defects. We used the constructed
+wide-field magnetic microscope for measurements of two kinds of magnetic
+defects in thin films. One family of defects under study was a result of
+non-optimal thin film growth conditions. The magnetic field maps of several
+regions of the thin films created under very similar conditions to previously
+published research revealed microscopic impurity islands of ferromagnetic
+defects, that potentially could disturb the magnetic properties of the surface.
+The second part of the measurements was dedicated to defects created post
+deposition - mechanical defects introduced in ferromagnetic thin films. In both
+cases, the measurements identify the magnetic field amplitude and distribution
+of the magnetic defects. In addition, the magnetic field maps were correlated
+with the corresponding optical images. As this method has great potential for
+quality control of different stages of magnetic thin film manufacturing process
+and it can rival other widely used measurement techniques, we also propose
+solutions for the optimization of the device in the perspective of high
+throughput.",2010.16197v1
+2020-11-20,An Investigation of Commercial Iron Oxide Nanoparticles: Advanced Structural and Magnetic Properties Characterization,"Magnetic nanoparticles (MNPs) have been extensively used as tiny heating
+sources in magnetic hyperthermia therapy, contrast agents in magnetic resonance
+imaging (MRI), tracers in magnetic particle imaging (MPI), carriers for
+drug/gene delivery, etc. There have emerged many magnetic
+nanoparticle/microbeads suppliers since the last decade, such as Ocean
+NanoTech, Nanoprobes, US Research Nanomaterials, Miltenyi Biotec, micromod
+Partikeltechnologie GmbH, and nanoComposix, etc. In this paper, we report the
+physical and magnetic characterizations on iron oxide nanoparticle products
+from Ocean NanoTech. Standard characterization tools such as Vibrating-Sample
+Magnetometer (VSM), X-Ray Diffraction (XRD), Dynamic Light Scattering (DLS),
+Transmission Electron Microscopy (TEM), and Zeta Potential Analyzer are used to
+provide magnetic nanoparticle customers and researchers with an overview of
+these iron oxide nanoparticle products. In addition, the dynamic magnetic
+responses of these iron oxide nanoparticles in aqueous solutions are
+investigated under low and high frequency alternating magnetic fields, giving a
+standardized operating procedure for characterizing the MNPs from Ocean
+NanoTech, thereby yielding the best of magnetic nanoparticles for different
+applications.",2011.10215v1
+2021-01-26,Understanding Magnetism in Double Double Perovskites: A Complex Multiple Magnetic Sublattice System,"Understanding magnetism in multiple magnetic sublattice system, driven by the
+interplay of varied nature of magnetic exchanges, is on one hand challenging
+and on other hand intriguing. Motivated by the recent synthesis of AA'BB'O_6
+double double perovskites with multiple magnetic ions both at A- and B-sites,
+we investigate the mechanism of magnetic behavior in these interesting class of
+compounds. We find that the magnetism in such multiple sublattice compounds is
+governed by the interplay and delicate balance between two distinct mechanisms,
+a) kinetic energy-driven multiple sublattice double exchange mechanism and b)
+the conventional super-exchange mechanism. The derived spin Hamiltonian based
+on first-principles calculations is solved by the classical Monte Carlo
+technique which reproduces the observed magnetic properties. Finally, the
+influence of off-stoichiometry, as in experimental samples, is discussed. Some
+of these double double perovskite compounds are found to possess large total
+magnetic moment and also are found to be half-metallic, which raises the hope
+of future applications of these large magnetic moment half-metallic oxides in
+spintronics and memory devices.",2101.10822v1
+2021-03-16,Efficient field-free perpendicular magnetization switching by a magnetic spin Hall effect,"Current induced spin-orbit torques driven by the conventional spin Hall
+effect are widely used to manipulate the magnetization. This approach, however,
+is nondeterministic and inefficient for the switching of magnets with
+perpendicular magnetic anisotropy that are demanded by the high-density
+magnetic storage and memory devices. Here, we demonstrate that this limitation
+can be overcome by exploiting a magnetic spin Hall effect in noncollinear
+antiferromagnets, such as Mn3Sn. The magnetic group symmetry of Mn3Sn allows
+generation of the out-of-plane spin current carrying spin polarization induced
+by an in-plane charge current. This spin current drives an out-of-plane
+anti-damping torque providing deterministic switching of perpendicular
+magnetization of an adjacent Ni/Co multilayer. Compared to the conventional
+spin-orbit torque devices, the observed switching does not need any external
+magnetic field and requires much lower current density. Our results demonstrate
+great prospects of exploiting the magnetic spin Hall effect in noncollinear
+antiferromagnets for low-power spintronics.",2103.09011v1
+2021-05-09,"Degenerate magnetic ground state and metastable state on trihexagonal Co-sublattices in Co3Sn2(S,Se)2 single crystals","A trihexagonal lattice has been predicted to retain a degenerate magnetic
+state which enriches physical properties. Especially, Co3Sn2S2, possessing
+trihexagonal Co-sublattices, has been observed to own topological quantum
+properties. Experimentally, Co3Sn2S2 has been reported to have hidden magnetic
+phases due to magnetic anomalies. To clarify the hidden magnetic phase, we
+fabricated high-quality single crystals of Co3Sn2S2-xSex (x = 0, 0.26, & 0.86).
+The Se-substitution is intended to broaden the distance between Co atoms. For
+each Se-composition, magnetizations of single-crystalline Co3Sn2S2-xSex
+implicate that the magnetic ground state consists of the out-of-plane
+ferromagnetism and the in-plane antiferromagnetism: Being degenerate.
+Meanwhile, along out-of-plane, remanent magnetizations of Co3Sn2S2-xSex have a
+first-order phase transition, so Co3Sn2S2-xSex owns an excited magnetic state,
+denoted as the metastable state. Consequently, we have provided semiclassical
+magnetic structures of the degenerate ground state and the metastable state via
+both magnetic symmetries and experimental constraints. Moreover, we have
+discovered mechanisms raising degeneracy and metastability.",2105.03892v1
+2021-07-02,Off-axis gyration induces large-area circular motion of anisotropic microparticles in a dynamic magnetic trap,"Magnetic tweezers are crucial for single-molecule and atomic
+characterization, and biomedical isolation of microparticle carriers. The
+trapping component of magnetic tweezing can be relying on a magnetic potential
+well that can confine the relevant species to a localized region. Here, we
+report that magnetic microparticles with tailored anisotropy can transition
+from localized off-axis gyration to large-area locomotion in a rotating
+magnetic trap. The microparticles, consisting of assemblies of magnetic cores,
+are observed to either rotate about its structural geometric center or gyrate
+about one of the magnetic cores, the switching of which can be modulated by the
+external field. Raising the magnetic field strength above a threshold, the
+particles can go beyond the traditional synchronous-rotation and
+asynchronous-oscillation modes, and into a scenario of large-area circular
+motion. This results in peculiar retrograde locomotion related to the
+magnetization maxima of the microparticle. Our finding suggests the important
+role of the microparticle's magnetic morphology in the controlled transport of
+microparticles and developing smart micro-actuators and micro-robot devices.",2107.00869v1
+2021-07-27,Nonreciprocal magnon excitations by the Dzyaloshinskii-Moriya interaction on the basis of bond magnetic toroidal multipoles,"The microscopic conditions for the emergence of nonreciprocal magnon
+excitations in noncentrosymmetric magnets are theoretically investigated. We
+show that asymmetric magnon excitations appear when a bond magnetic toroidal
+dipole becomes active, which is defined as a parallel component between the
+Dzyaloshinskii-Moriya vector and the averaged spin moments at the ends of the
+bonds. Depending on magnetic structures accompanying the bond magnetic toroidal
+dipoles, the higher-rank magnetic toroidal multipoles can also be activated in
+a magnetic cluster, which describes various angle dependences of asymmetric
+magnon excitations. We demonstrate a variety of asymmetric magnon excitations
+for two magnetic systems in the noncentrosymmetric lattice structures; a
+one-dimensional breathing chain under a uniform crystalline electric field and
+a three-dimensional layered breathing kagome structure. We show that a bottom
+shift of magnon bands occurs by the magnetic toroidal dipole and a valley
+splitting occurs by the magnetic toroidal octupole under magnetic orderings.",2107.12743v1
+2021-07-27,Biermann Battery Magnetic Fields in ICF Capsules: Total Magnetic Flux Generation,"This paper focuses on the process of magnetic flux generation in ICF
+implosions. Hot-spots are shown to be dominated by fields generated during
+stagnation, when the temperature and density gradients are largest. A scaling
+of hot-spot magnetic flux is derived and compared with simulations, revealing
+that perturbations with both larger amplitudes and higher mode numbers generate
+more magnetic flux. The model allows for greater understanding of which target
+designs will be susceptible to MHD effects. For example, the model can be used
+to ascertain the time when most magnetic flux is generated. If generation is
+weighted more towards early times, then more high-mode magnetic field loops
+will be present. A hot-spot with no high-mode perturbations at time of peak
+neutron production can still contain significant magnetic flux on those scales.
+By assuming that magnetic flux is deposited at the hot-spot edge by Nernst
+advection, the model can be used to post-process radiation-hydrodynamics data
+to estimate magnetic field strengths and magnetizations.",2107.13036v1
+2021-09-23,Tuning magnetic antiskyrmion stability in tetragonal inverse Heusler alloys,"The identification of materials supporting complex, tunable magnetic order at
+ambient temperatures is foundational to the development of new magnetic device
+architectures. We report the design of Mn2XY tetragonal inverse Heusler alloys
+that are capable of hosting magnetic antiskyrmions whose stability is sensitive
+to elastic strain. We first construct a universal magnetic Hamiltonian
+capturing the short- and long- range magnetic order which can be expected in
+these materials. This model reveals critical combinations of magnetic
+interactions that are necessary to approach a magnetic phase boundary, where
+the magnetic structure is highly susceptible to small perturbations such as
+elastic strain. We then computationally search for quaternary Mn2(X1,X2)Y
+alloys where these critical interactions may be realized and which are likely
+to be synthesizable in the inverse Heusler structure. We identify the
+Mn2Pt(1-z)X(z)Ga family of materials with X=Au, Ir, Ni as an ideal system for
+accessing all possible magnetic phases, with several critical compositions
+where magnetic phase transitions may be actuated mechanically.",2109.11423v1
+2021-10-29,Two types of magnetic bubbles in MnNiGa observed via Lorentz microscopy,"Magnetic bubbles are remarkable spin structures that developed in uniaxial
+magnets with strong magnetocrystalline anisotropy. Several contradictory
+reports have been published concerning the magnetic bubble structure in a
+metallic magnet MnNiGa: Biskyrmions or type-II bubbles. Lorentz microscopy in
+polycrystalline MnNiGa was used to explain the magnetic bubble structure.
+Depending on the connection between the magnetic easy axis and the observation
+plane, two types of magnetic bubbles were formed. Magnetic bubbles with
+180{\deg} domains were formed if the easy axis was away from the direction
+perpendicular to the observation plane. The contrast of biskyrmion is
+reproduced by this form of a magnetic bubble. When the easy axis was
+approximately perpendicular to the observing plane, type-II bubbles were
+observed in the same specimen. The findings will fill a knowledge gap between
+prior reports on magnetic bubbles in MnNiGa.",2110.15507v1
+2021-12-02,Hamilton-Jacobi Equations of Nonholonomic Magnetic Hamiltonian Systems,"In order to describe the impact of different geometric structures and
+constraints for the dynamics of a Hamiltonian system, in this paper, for a
+magnetic Hamiltonian system defined by a magnetic symplectic form, we first
+drive precisely the geometric constraint conditions of magnetic symplectic form
+for the magnetic Hamiltonian vector field.which are called the Type I and Type
+II of Hamilton-Jacobi equation. Secondly, for the magnetic Hamiltonian system
+with nonholonomic constraint, we first define a distributional magnetic
+Hamiltonian system, then derive its two types of Hamilton-Jacobi equation.
+Moreover, we generalize the above results to nonholonomic reducible magnetic
+Hamiltonian system with symmetry. We define a nonholonomic reduced
+distributional magnetic Hamiltonian system, and prove two types of
+Hamilton-Jacobi theorem. These research work reveal the deeply internal
+relationships of the magnetic symplectic structure, nonholonomic constraint,
+the distributional two-form, and the dynamical vector field of the nonholonomic
+magnetic Hamiltonian system.",2112.00961v2
+2021-12-31,Tunable magnetic field source for magnetic field imaging microscopy,"In this work we present a novel, compact, power efficient magnetic field
+source design for magnetic field imaging microscopy. The device is based on a
+pair of diametrically magnetized permanent magnet cylinders with
+electro-mechanical rotation control and ferrite field concentrators. A Hall
+probe and NV centers in diamond are used to demonstrate a proof of concept of a
+proposed magnetic field setup and to characterise the homogeneity of the
+produced magnetic field on a micrometer scale. Numerical simulation results are
+compared with experimental results showing good agreement of the distribution
+of the magnetic field in the setup. As a result, a magnetic field source with a
+tunable field amplitude in the range from 1 mT to 222 mT is demonstrated,
+achieving a magnetic field homogeneity of 2 ppm/$\mu$m or 0.5 $\mu$T/$\mu$m at
+222 mT in a 25$\times$25 $\mu$m field of view.",2112.15359v1
+2022-01-01,"Nanomagnetism in porous amorphous palladium, a sequel. A possible light-weight magnet","Magnetism is a very relevant subject that permeates our everyday lives.
+However, magnetism keeps taking us from surprise to surprise which seems to
+indicate that it is a phenomenon not well understood. For example, we found
+that bulk amorphous palladium becomes magnetic; so, naturally one should ask,
+could defective palladium develop magnetism? In particular, would amorphous
+porous palladium become magnetic? Here we show that the answer to that question
+is affirmative, this defective topology of Pd is magnetic, with a magnetism
+that depends on the amount of sample porosity and on the topology of their
+structures. Clearly, if magnetism exists in porous amorphous palladium, this
+indicates the possibility of developing light-weight magnets, useful when a
+maximized magnetism/weight ratio is demanded, well suited for space and
+aeronautical applications.",2201.00086v1
+2022-02-19,Controlling degeneracy and magnetization switching in an artificial spin ice system of peanut-shaped nanomagnets,"Using extensive numerical simulations, we probe the magnetization switching
+in two-dimensional artificial spin ice (ASI) system consisting of peanut-shaped
+nanomagnets. We also investigated the effect of the external magnetic field on
+the degeneracy of the magnetic states in such a system. The switching field is
+found to be one order smaller in the proposed ASI system with peanut-shaped
+nanomagnets as compared to the conventionally used highly-anisotropic
+nanoisland such as elliptically shaped nanomagnets. The metastable 2-in/2-out
+(Type II) magnetic state is robust at the remanence. We are also able to access
+the other possible microstates corresponding to Type II magnetic configurations
+by carefully varying the external magnetic field. It implies that one can
+control the degeneracy of the magnetic state by the application of a suitable
+magnetic field. Interestingly, the magnetic charge neutrality breaks due to the
+defects induced by removing nanomagnets. In such a case, the system also
+appears to have a 1-out/3-in or 3-out/1-in (Type III) spin state, reminiscent
+of a magnetic monopole. We believe that our study is highly desirable in the
+context of developing the next-generation spintronics-based devices for future
+technologies.",2202.09536v1
+2022-05-10,Non-hermitian off-diagonal magnetic response of Dirac fermions,"We perform a comparative study for the magnetization dynamics within linear
+response theory of one and two dimensional massive Dirac electrons, after
+switching on either a real (hermitian) or an imaginary (non-hermitian) magnetic
+field. While hermitian dc magnetic fields polarize the spins in the direction
+of the external magnetic field, non-hermitian magnetic fields induce only off
+diagonal response. An imaginary dc magnetic field perpendicular to the mass
+term induces finite magnetization in the third direction only according to the
+right hand rule. This can be understood by analyzing the non-hermitian equation
+of motion of the spin, which becomes analogous to a classical particle in
+crossed electric and magnetic fields. Therein, the spin expectation value, the
+mass term and imaginary magnetic field play the role of the classical momentum,
+magnetic and electric field, respectively. The latter two create a drift
+velocity perpendicular to them, which gives rise to the off-diagonal component
+of the dc spin susceptibility, similarly to how the Hall effect develops in the
+classical description.",2205.04795v2
+2022-05-13,Interaction of in-plane magnetic skyrmions with 90$^\circ$ magnetic domain walls: micromagnetic simulations,"$90^\circ$ pinned magnetic domain walls can be observed in thin magnetic
+layers attached to a ferroelectric substrate. The main stabilization mechanism
+of the noncollinear magnetic texture is the strain transfer which is
+responsible for imprinting of the ferroelectic domains into the uniaxial
+anisotropy of the ferromagnet. Here, we investigate by means of micromagnetic
+simulations how the interfacial Dzyaloshinkii-Moriya interaction influences the
+$90^\circ$ domain wall structure. It is shown that Dzyaloshinskii-Moriya
+interaction induces a large out-of-plane magnetization component, strongly
+dependent on the domain wall type. In particular, it is shown that this
+out-of-plane magnetization component is crucial for the transport of the
+in-plane magnetic skyrmions, also known as bimerons, through the magnetic
+domain walls. Based on the results of micromagnetic simulations, a concept of
+in-plane magnetic skyrmion valve based on two $90^\circ$ pinned magnetic domain
+walls is introduced.",2205.06876v1
+2022-05-16,Magneto-Transport Properties of Kagome Magnet TmMn$_6$Sn$_6$,"Kagome magnet usually hosts nontrivial electronic or magnetic states drawing
+great interests in condensed matter physics. In this paper, we report a
+systematic study on transport properties of kagome magnet TmMn$_6$Sn$_6$. The
+prominent topological Hall effect (THE) has been observed in a wide temperature
+region spanning over several magnetic phases and exhibits strong temperature
+and field dependence. This novel phenomenon due to non-zero spin chirality
+indicates possible appearance of nontrival magnetic states accompanying with
+strong fluctuations. The planar applied field drives planar Hall effect(PHE)
+and anistropic magnetoresisitivity(PAMR) exhibiting sharp disconnections in
+angular dependent planar resistivity violating the empirical law. By using an
+effective field, we identify a magnetic transition separating the PAMR into two
+groups belonging to various magnetic states. We extended the empirical formula
+to scale the field and temperature dependent planar magnetoresistivity and
+provide the understandings for planar transport behaviors with the crossover
+between various magnetic states. Our results shed lights on the novel transport
+effects in presence of multiple nontrivial magnetic states for the kagome
+lattice with complicated magnetic structures.",2205.07806v2
+2022-06-14,Frustration and ordering in Ising chain in an external magnetic field with third-neighbor interactions,"In this paper, the frustration properties of the Ising model on a
+one-dimensional monoatomic equidistant lattice in an external magnetic field
+are investigated, taking into account the exchange interactions of atomic spins
+at the sites of the first, second, and third neighbors. Exact analytical
+expressions for the thermodynamic functions of the system are obtained by the
+Kramers--Wannier transfer-matrix method. A magnetic phase diagram of the ground
+state of such a spin system is constructed and studied thoroughly. The points
+and lines of frustrations of the system depending on the values and signs of
+exchange interactions and on an external magnetic field are found. The criteria
+for the occurrence of magnetic frustrations in the presence of competition
+between the energies of exchange interactions and an external magnetic field
+are formulated. The peculiar features are investigated and the values of
+entropy and magnetization of the ground state of this model are obtained in the
+frustration regime and beyond it. Various types of behavior of entropy,
+magnetization, and magnetic susceptibility depending on the model parameters
+are revealed.",2206.06753v1
+2022-10-06,Field and temperature tuning of magnetic diode in permalloy honeycomb lattice,"The observation of magnetic diode behavior with ultra-low forward voltage of
+5 mV renders new venue for energetically efficient spintronic device research
+in the unconventional system of two-dimensional permalloy honeycomb lattice.
+Detailed understanding of temperature and magnetic field tuning of diode
+behavior is imperative to any practical application. Here, we report a
+comprehensive study in this regard by performing electrical measurements on
+magnetic diode sample as functions of temperature and magnetic field. Magnetic
+diode is found to persist across the broad temperature range. Magnetic field
+application unveils a peculiar reentrant characteristic where diode behavior is
+suppressed in remnant field but reappears after warming to room temperature.
+Analysis of I-V data suggests a modest energy gap, 0.03-0.1 eV, which is
+comparable to magnetic Coulomb's interaction energy between emergent magnetic
+charges on honeycomb vertices in the reverse biased state. It affirms the role
+of magnetic charge correlation in unidirectional conduction in 2D honeycomb
+lattice. The experimental results are expected to pave way for the utilization
+of magnetic diode in next generation spintronic device applications.",2210.03184v1
+2022-12-05,Magnetic Field Experiments Using a Phone,"To make physics experiments more directly relevant to everyday life and help
+students realize how their smart phones or tablets can be used as sensors for
+scientific measurements, we designed two introductory physics experiments to
+measure vector magnetic fields. These experiments were initially developed for
+students working remotely in an online course setting. However, the experiments
+can also be used for in-person laboratory activities. The first activity uses
+the phone's three-dimensional sensors to determine the vector components and
+orientation of the background magnetic field at the students' locations. The
+resulting vector magnetic field is compared to the expected Earth's magnetic
+field for their location. The second experiment uses the phone sensors to
+measure the magnet field produced by the small magnet found in the speaker of
+common earbuds, or in-ear headphones. The students then carefully investigate
+the dependence of the magnitude of the field on the axial distance between the
+speaker magnet and the phone's sensors. Using a ring magnet approximation,
+advanced Excel curve-fitting methods are introduced to determine the radius of
+the magnet in the earbud and the distance between the magnet's location and the
+external surface of the earbud housing.",2212.02258v1
+2022-12-16,Strong toroidal magnetic fields sustained by the elastic crust in a neutron star,"We investigate new solutions for magnetized neutron stars with a barotropic
+core in magnetohydrodynamic (MHD) equilibrium and a magneto-elastic crust,
+which was neglected by previous studies concerning stars in MHD equilibrium.
+The Lorentz force of the barotropic star is purely irrotational and the
+structures of magnetic fields are constrained. By contrast, a solenoidal
+component of the Lorentz force exists in the elastic crust and the structures
+of the magnetic fields are less restricted. We find that the minor solenoidal
+component in the elastic crust is important for sustaining the strong magnetic
+field in the core. Unlike previous studies, the toroidal magnetic field exists
+in the entire region of the core, and we obtain equilibrium states with large
+toroidal magnetic fields, where the toroidal magnetic energy is larger than the
+poloidal magnetic energy. The elastic force of the crust sustains an order of
+$10^{15}~\mathrm{G}$ toroidal magnetic field in the core, and the maximum
+strength of the toroidal magnetic field is approximately proportional to the
+crust thickness.",2212.08309v1
+2023-02-27,Energy Partition of Thermal and Nonthermal Particles in Magnetic Reconnection,"Magnetic reconnection has long been known to be the most important mechanism
+as quick conversion of magnetic field energy into plasma kinetic energy. In
+addition, energy dissipation by reconnection has gained attention not only as a
+plasma heating mechanism, but also as a plasma mechanism for accelerating
+nonthermal particles. However, the energy partitioning of thermal and
+nonthermal plasmas during magnetic reconnection is not understood. Here, we
+studied energy partition as a function of plasma sheet temperature and guide
+magnetic field. In relativistic reconnection with anti-parallel magnetic field
+or weak guide magnetic field, it was found that the nonthermal energy density
+can occupy more than $90 \%$ of the total kinetic plasma energy density, but
+strengthening the guide magnetic field suppresses the efficiency of the
+nonthermal particle acceleration. In nonrelativistic reconnection for
+anti-parallel magnetic field, most dissipated magnetic field energy is
+converted into thermal plasma heating. For a weak guide magnetic field with a
+moderate value, however, the nonthermal particle acceleration efficiency was
+enhanced, but strengthening the guide-field beyond the moderate value
+suppresses the efficiency.",2302.13517v1
+2023-03-10,New Research Trends in Electrically Tunable 2D van der Waals Magnetic Materials,"The recent discovery of two-dimensional (2D) van der Waals (vdW) magnetic
+materials has provided new, unprecedented opportunities for both fundamental
+science and technological applications. Unlike three-dimensional (3D) magnetic
+systems, the electric manipulation of vdW magnetism (e.g., magnetization state,
+magnetic anisotropy, magnetic ordering temperature) down to the monolayer limit
+at ambient conditions enables high efficiency operation and low energy
+consumption, which has the potential to revolutionize the fields of
+spintronics, spin-caloritronics, and valleytronics. This article provides an
+in-depth analysis of the recent progress, emerging opportunities, and technical
+challenges in the electric manipulation of magnetic functionalities of a wide
+variety of 2D vdW magnetic systems ranging from metals to semiconductors and
+heterostructures. The state-of-the-art understanding of the mechanisms behind
+the electric modulation of magnetism in these 2D vdW magnetic systems will
+drive future research towards novel applications in spintronics,
+spin-caloritronics, valleytronics, and quantum computation.",2303.05748v1
+2023-03-20,Six-degree-of-freedom Localization Under Multiple Permanent Magnets Actuation,"Localization of magnetically actuated medical robots is essential for
+accurate actuation, closed loop control and delivery of functionality. Despite
+extensive progress in the use of magnetic field and inertial measurements for
+pose estimation, these have been either under single external permanent magnet
+actuation or coil systems. With the advent of new magnetic actuation systems
+comprised of multiple external permanent magnets for increased control and
+manipulability, new localization techniques are necessary to account for and
+leverage the additional magnetic field sources. In this letter, we introduce a
+novel magnetic localization technique in the Special Euclidean Group SE(3) for
+multiple external permanent magnetic field actuation and control systems. The
+method relies on a milli-meter scale three-dimensional accelerometer and a
+three-dimensional magnetic field sensor and is able to estimate the full 6
+degree-of-freedom pose without any prior pose information. We demonstrated the
+localization system with two external permanent magnets and achieved
+localization errors of 8.5 ? 2.4 mm in position norm and 3.7 ? 3.6? in
+orientation, across a cubic workspace with 20 cm length.",2303.11059v1
+2023-04-03,Bloch-type magnetic skyrmions in two-dimensional lattice,"Magnetic skyrmions in two-dimensional lattice are a prominent topic of
+condensed matter physics and material science. Current research efforts in this
+field are exclusively constrained to Neel-type and antiskyrmion, while
+Bloch-type magnetic skyrmions are rarely explored. Here, we report the
+discovery of Bloch-type magnetic skyrmions in two-dimensional lattice of
+MnInP2Te6, using firstprinciples calculations and Monte-Carlo simulations.
+Arising from the joint effect of broken inversion symmetry and strong
+spin-orbit coupling, monolayer MnInP2Te6 presents large Dzyaloshinskii-Moriya
+interaction. This, along with ferromagnetic exchange interaction and
+out-ofplane magnetic anisotropy, gives rise to skyrmion physics in monolayer
+MnInP2Te6, without needing magnetic field. Remarkably, different from all
+previous works on two-dimensional lattice,the resultant magnetic skyrmions
+feature Bloch-type, which is protected by D3 symmetry.Furthermore, the
+Bloch-type magnetic bimerons are also identified in monolayer MnTlP2Te6. The
+phase diagrams of these Bloch-type topological magnetisms under magnetic field,
+temperature and strain are mapped out. Our results greatly enrich the research
+on magnetic skyrmions in twodimensional lattice.",2304.00671v1
+2023-05-07,Numerical simulation of a rotating magnetic sail for space applications,"The Magnetic Sail is a space propulsion system that utilizes the interaction
+between solar wind particles and an artificial dipole magnetic field generated
+by a spacecraft's coil to produce thrust without the need for additional plasma
+or propellant. To reduce the size of the sail while improving the efficiency of
+capturing solar wind, a new type of rotating magnetic sail with an initial
+rotation speed is proposed. This study evaluates the thrust characteristics,
+attitude, and size design factors of a rotating magnetic sail using a 3-D
+single-component particle numerical simulation. The results show that an
+increase in rotational speed significantly increases the thrust of the rotating
+magnetic sail. The thrust is most significant when the magnetic moment of the
+sail is parallel to the direction of particle velocity. The study also found
+that the potential for the application of the rotating magnetic sail is
+greatest in orbits with high-density and low-speed space plasma environments.
+It suggests that a rotating magnetic sail with a magnetic moment (Mm) of
+10^3-10^4 Am^2 operating at an altitude of 400 km in Low Earth Orbit (LEO) can
+achieve a similar thrust level to that of a rotating magnetic sail operating at
+1 AU (astronomical unit) of 10^7-10^8 Am^2.",2305.04212v1
+2023-07-18,Field-induced magnetic structures in the chiral polar antiferromagnet Ni$_2$InSbO$_6$,"We have performed $^{115}$In-NMR spectroscopy for Ni$_{2}$InSbO$_6$ with
+corundum-related crystal structure to reveal magnetic structures that develop
+in high magnetic fields. At low fields Ni$_{2}$InSbO$_6$ shows a helical
+magnetic order with a long wavelength because of its chiral and polar crystal
+structure. The field-induced magnetic state was not investigated by microscopic
+experiment because an extremely high magnetic field is required to modify the
+antiferromagnetically coupled helical structure. From the analysis of our
+$^{115}$In-NMR spectra obtained at high magnetic fields, we confirm that the
+canted antiferromagnetic structure appears in fields applied in the $[110]$
+direction and the propagation vector of magnetic helix is rotated toward the
+field direction for fields in the $[001]$ direction. We discuss the effect of
+magnetic field that modifies the magnetic structure of an antiferromagnetic
+chiral magnet.",2307.09082v1
+2023-08-22,Magical or magnetic? Less commonly taught facts about real-world permanent magnets and their diverse interactions with objects,"Permanent magnets are fascinating. They generate magnetic field and act as
+the key component in compasses, motors, speakers for practical applications.
+They are also made into magnetic toys for entertainment and education with
+magical magnetic tricks. Some of these tricks fueled the recent upsurge for
+magnetic-responsive objects including but not limited to a LK-99 mixture. A
+lack of full consideration of the magnetic interactions seems to be the reason
+why some tricks like ""half levitation"" is misinterpreted, and the situation is
+not really rectified in the following replications and discussions. Here I
+would like to go through some less commonly taught facts about real-world
+permanent magnets starting from the nonuniformity to their combined effects
+with other factors. Based on these facts, I will also break down the situation
+of some examples of how permanent magnets diversely interact even with ordinary
+objects, as one may have seen from recent sources. I believe this discussion is
+useful both in an informative and educational way, helping those who want to
+think deeper about magnetic mechanism beyond a simple attract/repel
+terminology.",2308.11542v1
+2023-09-07,Magnetization reversal in Fe(001) films grown by magnetic field assisted molecular beam epitaxy,"We studied the influence of a magnetic field (MF) on epitaxial growth and
+magnetic properties of Fe(001) films deposited on MgO(001). Thanks to modular
+sample holders and a specialized manipulator in our multi-chamber ultrahigh
+vacuum system, the films could be deposited and annealed in an in-plane MF of
+100 mT. In situ scanning tunnelling microscopy showed that MF had a strong
+influence on the film morphology, and, in particular, on the structure of
+surface steps. The magnetic properties were studied ex situ using magneto-optic
+Kerr effect (MOKE) magnetometry and microscopy. We showed that the moderate
+in-plane magnetic field applied during growth has the visible impact on the
+magnetic properties. The observed angular dependence of the MOKE loops and
+domain structures were discussed based on a magnetization reversal model. In
+particular we found that magnetization reversal occurs via 90{\deg} domains and
+the reversal differs for the no-field and in-field grown samples, in
+correlation with the film morphology.",2309.03583v1
+2023-09-22,Electric control of optically-induced magnetization dynamics in a van der Waals ferromagnetic semiconductor,"Electric control of magnetization dynamics in two-dimensional (2D) magnetic
+materials is an essential step for the development of novel spintronic
+nanodevices. Electrostatic gating has been shown to greatly affect the static
+magnetic properties of some van der Waals magnets, but the control over their
+magnetization dynamics is still largely unexplored. Here we show that the
+optically-induced magnetization dynamics in the van der Waals ferromagnet
+Cr$_2$Ge$_2$Te$_6$ can be effectively controlled by electrostatic gates, with a
+one order of magnitude change in the precession amplitude and over 10% change
+in the internal effective field. In contrast to the purely thermally-induced
+mechanisms previously reported for 2D magnets, we find that coherent
+opto-magnetic phenomena play a major role in the excitation of magnetization
+dynamics in Cr$_2$Ge$_2$Te$_6$. Our work sets the first steps towards electric
+control over the magnetization dynamics in 2D ferromagnetic semiconductors,
+demonstrating their potential for applications in ultrafast opto-magnonic
+devices.",2309.12776v1
+2023-09-26,Soft X-ray phase nano-microscopy of micrometre-thick magnets,"Imaging of nanoscale magnetic textures within extended material systems is of
+critical importance both to fundamental research and technological
+applications. Whilst high resolution magnetic imaging of thin nanoscale samples
+is well-established with electron and soft X-ray microscopy, the extension to
+micrometer-thick systems with hard X-rays currently limits high resolution
+imaging to rare-earth magnets. Here we overcome this limitation by establishing
+soft X-ray magnetic imaging of micrometer-thick systems using the pre-edge
+phase X-ray Magnetic Circular Dichroism signal, thus making possible the study
+of a wide range of magnetic materials. By performing dichroic
+spectro-ptychography, we demonstrate high spatial resolution imaging of
+magnetic samples up to 1.7 {\mu}m thick, an order of magnitude higher than
+conventionally possible with absorption-based techniques. This new regime of
+magnetic imaging makes possible the study of extended non rare-earth systems
+that have until now been inaccessible, from magnetic textures for future
+spintronic applications to non-rare-earth permanent magnets.",2309.14969v1
+2023-10-03,Permanent Magnets Based on Hard Ferrite Ceramics,"Permanent magnets are integral components in many of the modern technologies
+that are critical for the transition to a sustainable society. However, most of
+the high-performance (BHmax > 100 kJ/m3) permanent magnets that are currently
+employed contain rare earth elements (REE), which have long been classified as
+critical materials with a high supply risk and concerns regarding pollution in
+their mining. Therefore, suitable REE-lean/free magnets must be developed in
+order to ensure the sustainability of clean energy generation and electric
+mobility. The REE-free hexagonal ferrites (or hexaferrites) are the most used
+permanent magnets across all applications, with an 85 wt.% pie of the permanent
+magnet market. They are the dominant lower-grade option (BHmax < 25 kJ/m3) due
+to their relatively good hard magnetic properties, high Curie temperature (>700
+K), low cost and good chemical stability. In recent years, the hexaferrites
+have also emerged as candidates for substituting REE-based permanent magnets in
+applications requiring intermediate magnetic performance (25-100 kJ/m3), due to
+considerable performance improvements achieved through chemical tuning,
+nanostructuring and compaction/sintering optimization. This chapter reviews the
+state-of-the-art sintering strategies being investigated with the aim of
+manufacturing hexaferrite magnets with optimized magnetic properties,
+identifying key challenges and highlighting the natural future steps to be
+followed.",2310.02106v1
+2023-10-25,Phase Change Induced Magnetic Switching through Metal-insulator Transition in VO2/TbFeCo Films,"The ability to manipulate spins in magnetic materials is essential in
+designing spintronics devices. One method for magnetic switching is through
+strain. In VO2 on TiO2 thin films, while VO2 remains rutile across the
+metal-insulator transition, the in-plane lattice area expands going from low
+temperature insulating phase to high temperature conducting phase. In a
+VO2/TbFeCo bilayer, the expansion of the VO2 lattice area exerts tension on the
+amorphous TbFeCo layer. Through the strain effect, magnetic properties,
+including the magnetic anisotropy and magnetization, of TbFeCo can be changed.
+In this work, the changes in magnetic properties of TbFeCo on VO2/TiO2(011) are
+demonstrated using anomalous Hall effect measurements. Across the
+metal-insulator transition, TbFeCo loses perpendicular magnetic anisotropy, and
+the magnetization in TbFeCo turns from out-of-plane to in-plane. Using
+atomistic simulations, we confirm these tunable magnetic properties originating
+from the metal-insulator transition of VO2. This study provides the groundwork
+for controlling magnetic properties through a phase transition.",2310.17045v1
+2023-12-05,THz-Driven Coherent Magnetization Dynamics in a Labyrinth Domain State,"Terahertz (THz) light pulses can be used for an ultrafast coherent
+manipulation of the magnetization. Driving the magnetization at THz frequencies
+is currently the fastest way of writing magnetic information in ferromagnets.
+Using time-resolved resonant magnetic scattering, we gain new insights to the
+THz-driven coherent magnetization dynamics on nanometer length scales. We
+observe ultrafast demagnetization and coherent magnetization oscillations that
+are governed by a time-dependent damping. This damping is determined by the
+interplay of lattice heating and magnetic anisotropy reduction revealing an
+upper speed limit for THz-induced magnetization switching. We show that in the
+presence of nanometer-sized magnetic domains, the ultrafast magnetization
+oscillations are associated with a correlated beating of the domain walls. The
+overall domain structure thereby remains largely unaffected which highlights
+the applicability of THz-induced switching on the nanoscale.",2312.02654v1
+2023-12-18,Doping-control of excitons and magnetism in few-layer CrSBr,"Magnetism in two-dimensional materials reveals phenomena distinct from bulk
+magnetic crystals, with sensitivity to charge doping and electric fields in
+monolayer and bilayer van der Waals magnet CrI3. Within the class of layered
+magnets, semiconducting CrSBr stands out by featuring stability under ambient
+conditions, correlating excitons with magnetic order and thus providing strong
+magnon-exciton coupling, and exhibiting peculiar magneto-optics of
+exciton-polaritons. Here, we demonstrate that both exciton and magnetic
+transitions in bilayer and trilayer CrSBr are sensitive to voltage-controlled
+field-effect charging, exhibiting bound exciton-charge complexes and
+doping-induced metamagnetic transitions. Moreover, we demonstrate how these
+unique properties enable optical probes of local magnetic order, visualizing
+magnetic domains of competing phases across metamagnetic transitions induced by
+magnetic field or electrostatic doping. Our work identifies few-layer CrSBr as
+a rich platform for exploring collaborative effects of charge, optical
+excitations, and magnetism.",2312.11041v1
+2023-12-18,Enhancing thermal stability of optimal magnetization reversal in nanoparticles,"Energy-efficient switching of nanoscale magnets requires the application of a
+time-varying magnetic field characterized by microwave frequency. At finite
+temperatures, even weak thermal fluctuations create perturbations in the
+magnetization that can accumulate in time, break the phase locking between the
+magnetization and the applied field, and eventually compromise magnetization
+switching. It is demonstrated here that the magnetization reversal is mostly
+disturbed by unstable perturbations arising in a certain domain of the
+configuration space of a nanomagnet. The instabilities can be suppressed and
+the probability of magnetization switching enhanced by applying an additional
+stimulus such as a weak longitudinal magnetic field that ensures bounded
+dynamics of the perturbations. Application of the stabilizing longitudinal
+field to a uniaxial nanomagnet makes it possible to reach a desired probability
+of magnetization switching even at elevated temperatures. The principle of
+suppressing instabilities provides a general approach to enhancing thermal
+stability of magnetization dynamics.",2312.11293v1
+2023-12-19,Pseudo-fermion functional renormalization group with magnetic fields,"The pseudo-fermion functional renormalization group is generalized to treat
+spin Hamiltonians with finite magnetic fields, enabling its application to
+arbitrary spin lattice models with linear and bilinear terms in the spin
+operators. We discuss in detail an efficient numerical implementation of this
+approach making use of the system's symmetries. Particularly, we demonstrate
+that the inclusion of small symmetry breaking magnetic seed fields regularizes
+divergences of the susceptibility at magnetic phase transitions. This allows
+the investigation of spin models within magnetically ordered phases at $T=0$ in
+the physical limit of vanishing renormalization group parameter $\Lambda$. We
+explore the capabilities and limitations of this method extension for
+Heisenberg models on the square, honeycomb and triangular lattices. While the
+zero-field magnetizations of these systems are systematically overestimated,
+the types of magnetic orders are correctly captured, even if the local
+orientations of the seed field are chosen differently than the spin
+orientations of the realized magnetic order. Furthermore, the magnetization
+curve of the square lattice Heisenberg antiferromagnet shows good agreement
+with error controlled methods. In the future, the inclusion of magnetic fields
+in the pseudo-fermion functional renormalization group, which is also possible
+in three dimensional spin systems, will enable a variety of additional
+interesting applications such as the investigation of magnetization plateaus.",2312.12097v1
+2024-01-02,Development of the CMS Magnetic Field Map,"This article focuses on pioneering work on the performance of the
+three-dimensional (3D) magnetic field map in the entire volume of the Compact
+Muon Solenoid (CMS) detector at the Large Hadron Collider at CERN. In the CMS
+heterogeneous magnetic system, the magnetic flux is created by a
+superconducting solenoid coil enclosed in a steel flux-return yoke. To describe
+the CMS magnetic flux distribution, a system of the primitive 3D volumes
+containing the values of the magnetic flux density measured inside the
+superconducting coil inner volume and modelled outside the coil across a
+special mesh of reference nodes was developed. This system, called the CMS
+magnetic field map, follows the geometric features of the yoke and allows the
+interpolation of the magnetic flux density between the nodes to obtain the
+magnetic field values at any spatial point inside a cylinder of 18 m in
+diameter and 48 m in length, where all the CMS sub-detectors are located. The
+geometry of the volumes is described inside one 30{\deg} azimuthal sector of
+the CMS magnet. To obtain the values of the magnetic flux density components
+across the entire azimuth angle of the CMS detector, rotational symmetry is
+applied.",2401.01913v1
+2024-01-15,Calculating Magnetic Properties of Two-Dimensional Materials for Memory Applications,"Calculating magnetic properties of two-dimensional materials is crucial for
+implementing memory devices (like USB drive, RAM, hard disk drive of computers)
+having reduced size. Two dimensional materials can be implemented as a thin
+film which can reduce the size of memory devices. These materials as well as
+devices made with magnetic two-dimensional materials are of current research
+interest in industry and academia. From the materials project database, crystal
+structure file of 30 two dimensional materials have been downloaded to
+calculate their magnetic properties. BURAI Quantum espresso software has been
+used to extract magnetic properties of 30 two dimensional (2D) materials. These
+30 materials have magnetic Fe, Ni, Co, Mn, and Cr atoms in their molecular
+structure. Magnetic materials play a key and vital role in today's modern-day
+technology. There are five different types of magnetic materials. The
+classification magnetic materials are diamagnetism, paramagnetic,
+ferromagnetism, ferrimagnetism, and anti-ferromagnetism. Total energy of
+different magnetic configurations has been calculated to find the most stable
+magnetic configurations of these materials.",2401.07980v1
+2024-01-25,Magnetic fields of protoplanetary disks,"We review the current status of studies on accretion and protoplanetary disks
+of young stars with large-scale magnetic fields. Observational data on magnetic
+fields of the disks are compiled and analysed. Modern analytical and numerical
+MHD models of protoplanetary disks are discussed. The mechanisms of angular
+momentum transport via turbulence, magnetic tensions and outflows are outlined.
+We consider the influence of Ohmic dissipation, magnetic ambipolar diffusion,
+magnetic buoyancy, and the Hall effect on the evolution of the magnetic flux in
+disks. Modern MHD models of accretion disks show that the magnetic field can
+influence the structure of protoplanetary disks. We argue that the available
+observational data on the magnetic fields in protoplanetary disks can be
+interpreted within the framework of fossil magnetic field theory. We summarize
+the problems of the modern theory of accretion and protoplanetary disks with
+magnetic fields and also outline the prospects for further research.",2401.14180v1
+2024-02-28,Magnetization fluctuations and magnetic aftereffect probed via the anomalous Hall effect,"Taking advantage of the anomalous Hall effect, we electrically probe
+low-frequency magnetization fluctuations at room temperature in a thin
+ferromagnetic Pt/Co/AlO$_x$ layer stack with perpendicular magnetic anisotropy.
+We observe a strong enhancement of the Hall voltage fluctuations within the
+hysteretic region of the magnetization loop. Analyzing both the temporal
+evolution of the anomalous Hall voltage and its frequency-dependent noise power
+density, we identify two types of magnetic noise: abrupt changes in the
+magnetic domain configuration, evident as Barkhausen-like steps in the Hall
+voltage time trace, yield a noise power density spectrum scaling with frequency
+as $1/f^{\beta}$ with $\beta\approx 1.9$. In contrast, quasi-stationary
+magnetization configurations are connected with a magnetic noise power density
+with an exponent $\beta\approx 0.9$. The observation of Barkausen steps and
+relaxation effects shows that the magnetic system is in a non-stationary state
+in the hysteresis region, such that the fluctuation-dissipation theorem cannot
+be expected to hold. However, the time-dependent change in the Hall voltage for
+constant magnetic field strength resembles the integrated noise power.",2402.18436v1
+2024-03-14,Chiral gauge field in fully-spin polarized Weyl semimetal with magnetic domain walls,"Modulation of magnetization in magnetic Weyl semimetals leads to the shift of
+Weyl points in momentum space, which effectively serves as the
+chirality-dependent gauge field for the Weyl fermions. Here, we theoretically
+study such a magnetization-induced chiral gauge field, in a fully
+spin-polarized Weyl ferromagnet $\rm{Co}_3\rm{Sn}_2\rm{S}_2$. From a
+tight-binding model of $\rm{Co}_3\rm{Sn}_2\rm{S}_2$ on stacked kagome lattice
+with magnetism, we calculate the magnetization-dependent evolution of the Weyl
+points in momentum space, resulting in the chiral gauge field. In the presence
+of the magnetic domain wall structure, we evaluate the chiral magnetic field
+arising from the spatial profile of the chiral gauge field. We find that a
+magnetic domain wall in $\rm{Co}_3\rm{Sn}_2\rm{S}_2$ gives rise to a giant
+chiral magnetic field for the Weyl fermions, which reaches the order of a few
+hundred tesla to induce the Landau quantization. Such a giant chiral magnetic
+field may also influence the novel transport phenomena, such as the charge
+pumping by the domain wall motion, compatible with the spin-motive force.",2403.09535v1
+2024-04-01,"Harnessing Interlayer Magnetic Coupling for Efficient, Field-Free Current-Induced Magnetization Switching in a Magnetic Insulator","Owing to the unique features of low Gilbert damping, long spin-diffusion
+lengths and zero Ohmic losses, magnetic insulators are promising candidate
+materials for next-generation spintronic applications. However, due to the
+localized magnetic moments and the complex metal-oxide interface between
+magnetic insulators and heavy metals, spin-functional Dzyaloshinskii-Moriya
+interactions or spin Hall and Edelstein effects are weak, which diminishes the
+performance of these typical building blocks for spintronic devices. Here, we
+exploit the exchange coupling between metallic and insulating magnets for
+efficient electrical manipulation of heavy metal/magnetic insulator
+heterostructures. By inserting a thin Co layer, we enhance the spin-orbit
+torque efficiency by more than 20 times, which significantly reduces the
+switching current density. Moreover, we demonstrate field-free current-induced
+magnetization switching caused by a symmetry-breaking non-collinear magnetic
+texture. Our work launches magnetic insulators as an alternative platform for
+low-power spintronic devices.",2404.00845v1
+2001-11-16,Astrophysical Polarimetric Signature Against TeV Fundamental Planck Scale,"I present the analysis of data of astrophysical polarimetric observations
+that gives the signature of the fundamental extra dimension Planck scale
+magnitude essentially higher than $~1TeV$. Magnetic conversion of photons into
+the fundamental particles (scalars, gravitons) is the probable mechanism that
+can produce noticeable amount of polarization of optical radiation of
+astrophysical objects, especially, of distant extragalactic sources. The
+results of magnetic conversion process of optical light of extragalactic
+sources are presented for a number of situations including: (a) intergalactic
+magnetic field, (b) galaxy cluster magnetic field, (c) magnetic conversion in
+the typical galaxy magnetic field, (d) magnetic conversion of CMB radiation.",0111316v1
+2003-02-24,Thermal Conduction in Magnetized Turbulent Gas,"Using numerical methods, we systematically study in the framework of ideal
+MHD the effect of magnetic fields on heat transfer within a turbulent gas. We
+measure the rates of passive scalar diffusion within magnetized fluids and make
+the comparisons a) between MHD and hydro simulations, b) between different MHD
+runs with different values of the external magnetic field (up to the energy
+equipartition value), c) between thermal conductivities parallel and
+perpendicular to magnetic field. We do not find apparent suppression of
+diffusion rates by the presence of magnetic fields, which implies that magnetic
+fields do not suppress heat diffusion by turbulent motions.",0302503v1
+2004-09-07,Spectropolarimetry and Infrared Photometry of Magnetic White Dwarfs: Vacuum Polarization Effect or Magnetic CIA?,"We present brief review of two probable physical mechanisms that can explain
+the results of photometric and spectropolarimetric observations of magnetic
+white dwarfs: vacuum polarization effect into a strong magnetic field and,
+so-called, magnetic collision induced absorption (magnetic CIA). Both
+mechanisms provide observed rotation of polarization ellipse and suppression of
+spectral energy distributions. The results of spectropolarimetric observations
+of magnetic white dwarfs made at Russian BTA-6m and the results of the near
+infrared photometric observations with Russian-Italian AZT-24 telescope located
+at Campo Imperatore are also presented.",0409152v1
+2006-06-28,A Universal Magnetic Helicity Integral,"A magnetic helicity integral is proposed which can be applied to domains
+which are not magnetically closed, i.e. have a non-vanishing normal component
+of the magnetic field on the boundary. In contrast to the relative helicity
+integral, which was previously suggested for magnetically open domains, it does
+not rely on a reference field and thus avoids all problems related to the
+choice of a particular reference field. Instead it uses a gauge condition on
+the vector potential, which corresponds to a particular topologically unique
+closure of the magnetic field in the external space. The integral has
+additional elegant properties and is easy to compute numerically in practice.
+For magnetically closed domains it reduces to the classical helicity integral.",0606694v1
+1996-07-30,Non-magnetic impurities in two- and three- dimensional Heisenberg antiferromagnets,"In this paper we study in a large-S expansion effects of substituting spins
+by non-magnetic impurities in two- and three- dimensional Heisenberg
+antiferromagnets in a weak magnetic field. In particular, we demonstrate a
+novel mechanism where magnetic moments are induced around non-magnetic
+impurities when magnetic field is present. As a result, Curie-type behaviour in
+magnetic susceptibility can be observed well below the Neel temperature, in
+agreement with what is being observed in $La_2Cu_{1-x}Zn_{x}O_4$ and
+$Sr(Cu_{1-x}Zn_x)_2O_3$ compounds.",9607213v1
+1998-12-31,Magnetic skyrmion lattices in heavy fermion superconductor UPt3,"Topological analysis of nearly SO(3)_{spin} symmetric Ginzburg--Landau
+theory, proposed for UPt$_{3}$ by Machida et al, shows that there exists a new
+class of solutions carrying two units of magnetic flux: the magnetic skyrmion.
+These solutions do not have singular core like Abrikosov vortices and at low
+magnetic fields they become lighter for strongly type II superconductors.
+Magnetic skyrmions repel each other as $1/r$ at distances much larger then the
+magnetic penetration depth $\lambda$, forming a relatively robust triangular
+lattice. The magnetic induction near $H_{c1}$ is found to increase as
+$(H-H_{c1})^{2}$. This behavior agrees well with experiments.",9812435v2
+1999-07-07,Exotic structures on magnetic multilayers,"To characterize the possible magnetic structures created on magnetic
+multilayers a model has been formulated and studied. The interlayer
+inhomogeneous structures found indicate either (i) a regular periodic, (ii) a
+quasiperiodic change in the magnetization or (iii) spatially chaotic glass
+states. The magnetic structures created depend mainly on the ratio of the
+magnetic anisotropy constant to the exchange constant.
+  With the increase of this ratio the periodic structures first transform into
+the quasiperiodic and then into the chaotic glass states. The same tendency
+arises with the depolarization of the magnetic moments of the first layer
+deposited on the substrate.",9907099v1
+2000-05-17,Conversion of free magnetic polaron into vortex lattice in diluted magnetic semiconductors in quantizing magnetic fields,"We show that in strong (quantizing) magnetic fields ""ordinary"" free magnetic
+polaron in diluted magnetic semiconductors (of type $A^2MeB^6$, where Me=Fe,
+Mn) exists in the form of vortex lattice quite similar to that in type II
+superconductors (Abricosov vortex lattice). The region of external parameters
+(like external magnetic field and temperature), where such lattice exists, is
+determined from the condition that lattice dimension is less or equal to
+polaron localization radius.",0005285v1
+2000-10-20,Properties of a magnetic superconductor with weak magnetization - application to $ErNi_2B_2C$,"Using a Ginsburg-Landau free energy functional, we study the $H-T$ phase
+diagram of a weak magnetic superconductor, where the magnetization from the
+magnetic component is marginal in supporting a spontaneous vortex phase in
+absence of external magnetic field. In particular, the competition between the
+spiral state and spontaneous vortex phase is analysed. Our theory is applied to
+understand the magnetic properties of $ErNi_2B_2C$.",0010307v1
+2000-10-26,Magnetic storage device with improved temporal stability,"The current efforts to fabricate non-volatile magnetic recording media with a
+high areal density is deteriorated by the increasing temporal instability of
+the stored information. If the stored energy per magnetic particle competes
+with the thermal energy, spontaneous magnetic reversal processes may occur.
+Deposition of the magnetic particles on top of an antiferromagnetic substrate
+will increase its energy barrier due to the exchange coupling between the two
+subsystems. For this the magnetic moments of the antiferromagnet in the
+vicinity of the magnetic particle have to deviate from their undisturbed
+arrangement. This disturbation vanishes within a few lattice constants. In the
+framework of a classical spin model we calculate the spin arrangements and the
+resulting energy barriers for typical systems.",0010420v1
+2000-12-15,Effective Interaction Hamiltonian of Polaron Pairs in Diluted Magnetic Semiconductors,"The magnetic interaction of a pair of bound magnetic polarons (BMP) in
+diluted magnetic semiconductors (DMS) is analyzed via a generalized
+Hubbard-type Hamiltonian for two carriers in the presence of effective magnetic
+fields arising from the magnetic polarization of their respective polarons. For
+the case where the magnetic fields at the two sites have equal magnitude but
+are allowed to have arbitrary directions, it is shown that the energy of the
+two polarons is minimized for a ferromagnetic configuration of the carrier
+spins (in contrast to the case of hydrogenic centers in nonmagnetic
+semiconductors) if polaron fields are strong enough. A modified Heisenberg-type
+Hamiltonian is constructed to describe the low energy states of the resulting
+system.",0012279v1
+2002-05-15,Magnetism in a lattice of spinor Bose condensates,"We study the ground state magnetic properties of ferromagnetic spinor
+Bose-Einstein condensates confined in a deep optical lattices. In the Mott
+insulator regime, the ``mini-condensates'' at each lattice site behave as
+mesoscopic spin magnets that can interact with neighboring sites through both
+the static magnetic dipolar interaction and the light-induced dipolar
+interaction. We show that such an array of spin magnets can undergo a
+ferromagnetic or anti-ferromagnetic phase transition under the magnetic dipolar
+interaction depending on the dimension of the confining optical lattice. The
+ground-state spin configurations and related magnetic properties are
+investigated in detail.",0205319v1
+2003-05-28,Magnetic light,"In this paper we report on the observation of novel and highly unusual
+magnetic state of light. It appears that in small holes light quanta behave as
+small magnets so that light propagation through such holes may be affected by
+magnetic field. When arrays of such holes are made, magnetic light of the
+individual holes forms novel and highly unusual two-dimensional magnetic light
+material. Magnetic light may soon become a great new tool for quantum
+communication and computing.",0305661v1
+2003-06-18,Evidence for the coexistence of low-dimensional magnetism and long-range order in Ca3CoRhO6,"We report the results of neutron powder diffraction studies on the spin-chain
+compound Ca3CoRhO6 in the temperature range 3 to 293 K. Bragg peaks due to
+magnetic ordering start appearing below about 100 K. The most interesting
+observation is that there is a diffuse magnetic peak superimposed over the
+strongest magnetic Bragg peak. The diffuse magnetic intensity is observed below
+as well above 100 K. This finding provides a new insight into the physics of
+this compound as though the low-dimensional magnetic interaction coexists with
+long range magnetic order - a novel situation among quasi one-dimensional
+oxides.",0306481v1
+2003-07-10,Tunable Magnetic Relaxation In Magnetic Nanoparticles,"We investigate the magnetization dynamics of a conducting magnetic
+nanoparticle weakly coupled to source and drain electrodes, under the
+assumption that all relaxation comes from exchange of electrons with the
+electrodes. The magnetization dynamics is characterized by a relaxation time
+$t_1$, which strongly depends on temperature, bias voltage, and gate voltage.
+While a direct measure of a nanoparticle magnetization might be difficult, we
+find that $t_1$ can be determined through a time resolved transport
+measurement. For a suitable choice of gate voltage and bias voltage, the
+magnetization performs a bias-driven Brownian motion regardless of the presence
+of anisotropy.",0307256v1
+2003-12-11,Current-Driven Switching in Magnetic Multilayer Nanopillars,"We summarize our recent findings on how the current-driven magnetization
+switching in nanofabricated magnetic multilayers is affected by an applied
+magnetic field, changes of temperature, magnetic coupling between the
+ferromagnetic layers, variations in the multilayer structure, and the relative
+rotation of the layers' magnetizations. We show how these results can be
+interpreted with a model describing current-driven excitations as an effective
+current-dependent magnetic temperature.",0312287v1
+2003-12-22,Microscopic origin of the adiabatic change of magnetization in molecular magnets,"A microscopic model of the molecular magnet V15 is used to study mechanisms
+for the adiabatic change of the magnetization in time-dependent magnetic
+fields. Effects of the Dzyaloshinskii-Moriya interaction, the most plausible
+source for the energy-level repulsions that lead to adiabatic changes of the
+magnetization, are studied in detail. We find that the energy-level repulsions
+that result from this interaction exhibit a strong dependence on the direction
+of the applied field. We also discuss the role of magnetic anisotropy in the
+molecule Mn12 -acetate.",0312581v1
+2004-07-01,Propagation of a magnetic domain wall in magnetic wires with asymmetric notches,"The propagation of a magnetic domain wall (DW) in a submicron magnetic wire
+consisting of a magnetic/nonmagnetic/magnetic trilayered structure with
+asymmetric notches was investigated by utilizing the giant magnetoresistance
+effect. The propagation direction of a DW was controlled by a pulsed local
+magnetic field, which nucleates the DW at one of the two ends of the wire. It
+was found that the depinning field of the DW from the notch depends on the
+propagation direction of the DW.",0407006v1
+2004-09-03,Manipulating Current-Induced Magnetization Switching,"We summarize our recent findings on how current-driven magnetization
+switching and magnetoresistance in nanofabricated magnetic multilayers are
+affected by varying the spin-scattering properties of the non-magnetic spacers,
+the relative orientations of the magnetic layers, and spin-dependent scattering
+properties of the interfaces and the bulk of the magnetic layers. We show how
+our data are explained in terms of current-dependent effective magnetic
+temperature.",0409085v1
+2004-12-14,Entry of magnetic flux into a magnetically shielded type-II superconductor filament,"In the framework of the London approximation the magnetic flux penetration
+into a type-II superconductor filament surrounded by a soft-magnet sheath and
+exposed to a transverse external magnetic field is studied. The lower
+transverse critical field as well as the critical field and the critical
+current of the first vortex nucleation at the superconductor/magnet interface
+are calculated on the basis of an exact solution for a vortex of arbitrary
+plane configuration. The Bean-Livingston barrier against the vortex nucleation
+is shown to strongly depend on the magnet sheath parameters.",0412350v1
+2004-12-15,"Magnetic behavior of the spin-chain compounds,Ca3CuIrO6 and Ca3CuRhO6","The spin-chain compounds, Ca3CuIrO6 and Ca3CuRhO6, crystallizing in a
+K4CdCl6-derived monoclinic structure, are investigated by ac and dc
+magnetization, isothermal remnant magnetization as well as heat capacity
+measurements. The results reveal the existence of a magnetic ordering in the
+vicinity of 15 K for both the compounds, but the transition appears to be of a
+complex nature. The existence of a spin-glass component is strongly indicated
+by the results. We propose that topological effects play a role on magnetism of
+these compounds. The magnetic properties for these two compounds are
+interestingly similar as though isoelectronic chemical substitution at the
+octahedral coordination site does not significantly interfere in the magnetic
+exchange process.",0412386v1
+2004-12-17,Hysteresis loops of magnetic thin films with perpendicular anisotropy,"We model the magnetization of quasi two-dimensional systems with easy
+perpendicular (z-)axis anisotropy upon change of external magnetic field along
+z. The model is derived from the Landau-Lifshitz-Gilbert equation for
+magnetization evolution, written in closed form in terms of the z component of
+the magnetization only. The model includes--in addition to the external
+field--magnetic exchange, dipolar interactions and structural disorder. The
+phase diagram in the disorder/interaction strength plane is presented, and the
+different qualitative regimes are analyzed. The results compare very well with
+observed experimental hysteresis loops and spatial magnetization patterns, as
+for instance for the case of Co-Pt multilayers.",0412461v1
+2005-01-19,Anisotropic magnetization of RuEu1.5Ce0.5Sr2Cu2O10 (Ru-1222) thin films,"A dc magnetic study is reported on c-axis oriented epitaxial thin films of
+EuSr2Eu1.5Ce0.5Cu2O10 (Ru-1222) on (100) SrTiO3 wafers. Magnetic measurements
+on 200 and 500 nm thick films were performed with the magnetic field either
+parallel or perpendicular to the wafer. We found that the films order
+magnetically at 180 K. The easy axis of the magnetization is in the basal plane
+and the Ru5+ ions are in their high-spin state, as deduced from the isothermal
+magnetization curves at low temperatures. The anisotropy ratio was found to be
+7.5. The observed results are compared to data of the Ru-1222 ceramic material.",0501454v1
+2005-03-31,Boundary conditions for magnetization in magnetic nano-elements,"We show that the dynamic magnetization at the edges of a thin magnetic
+element with finite lateral size can be described by new effective boundary
+conditions that take into account inhomogeneous demagnetizing fields near the
+element edges. These fields play a dominant role in the effective pinning of
+the dynamic magnetization at the boundaries of mesoscopic and nano-sized
+magnetic elements. The derived effective boundary conditions generalize
+well-known Rado-Weertman boundary conditions and are reduced to them in the
+limiting case of a very thin magnetic element.",0503745v1
+2005-03-31,Spectroscopy of Magnetic Excitations in Magnetic Superconductors Using Vortex Motion,"In magnetic superconductors a moving vortex lattice is accompanied by an ac
+magnetic field which leads to the generation of spin waves. At resonance
+conditions the dynamics of vortices in magnetic superconductors changes
+drastically, resulting in strong peaks in the dc I-V characteristics at
+voltages at which the washboard frequency of vortex lattice matches the spin
+wave frequency $\omega_s({\bf g})$, where ${\bf g}$ are the reciprocal vortex
+lattice vectors. We show that if washboard frequency lies above the magnetic
+gap, peaks in the I-V characteristics in borocarbides and cuprate layered
+magnetic superconductors are strong enough to be observed over the background
+determined by the quasiparticles.",0504006v1
+2005-06-20,Monte Carlo study of half-magnetization plateau and magnetic phase diagram in pyrochlore antiferromagnetic Heisenberg model,"The antiferromagnetic Heisenberg model on a pyrochlore lattice under external
+magnetic field is studied by classical Monte Carlo simulation. The model
+includes bilinear and biquadratic interactions; the latter effectively
+describes the coupling to lattice distortions. The magnetization process shows
+a half-magnetization plateau at low temperatures, accompanied with strong
+suppression of the magnetic susceptibility. Temperature dependence of the
+plateau behavior is clarified. Finite-temperature phase diagram under the
+magnetic field is determined. The results are compared with recent experimental
+results in chromium spinel oxides.",0506500v2
+2005-07-13,Novel Magnetic and Thermodynamic Properties of Thiospinel Compound CuCrZrS$_{4}$,"We have carried out dc magnetic susceptibility, magnetization and specific
+heat measurements on thiospinel CuCrZrS$_{4}$. Below $T_{\rm C}^{*} =$ 58 K, dc
+magnetic susceptibility and magnetization data show ferromagnetic behavior with
+a small spontaneous magnetization 0.27 $\mu_{\rm B}/$f. u..
+  In dc magnetic susceptibility, large and weak irreversibilities are observed
+below $T_{\rm f} =$ 6 K and in the range $T_{\rm f}< T < T_{\rm C}^{*}$
+respectively.
+  We found that there is no anomaly as a peak or step in the specific heat at
+$T_{\rm C}^{*}$.",0507314v1
+2005-08-26,Kinetic arrest of the first order ferromagnetic to antiferromagnetic transition in Ce(Fe$_{0.96}$Ru$_{0.04}$)$_2$ : formation of a magnetic-glass,"We present results of dc magnetization and magnetic relaxation study showing
+the kinetic arrest of a first order ferromagnetic to antiferromagnetic
+transition in Ce(Fe$_{0.96}$Ru$_{0.04}$)$_2$. This leads to the formation of a
+non-ergodic glass-like magnetic state. The onset of the magnetic-glass
+transformation is tracked through the slowing down of the magnetization
+dynamics. This glassy state is formed with the assistance of an external
+magnetic field and this is distinctly different from the well known
+'spin-glass' state.",0508625v1
+2005-09-26,Charge and Magnetization Inhomogeneities in Diluted Magnetic Semiconductors,"It is predicted that III-V diluted magnetic semiconductors can exhibit
+stripe-like modulations of magnetization and carrier concentration. This
+inhomogeneity results from the strong dependence of the magnetization on the
+carrier concentration. Within Landau theory, a characteristic temperature T*
+below the Curie temperature is found so that below T* the equilibrium
+magnetization shows modulations, which are strongly anharmonic. Wavelength and
+amplitude of the modulation rise for decreasing temperature, starting from zero
+at T*. Above T* the equilibrium state is homogeneous, but the coupling between
+charge and magnetization leads to the appearance of an electrically charged
+layer in domain walls.",0509653v2
+2005-11-05,Ratchet Effect in Magnetization Reversal of Stoner Particles,"A new strategy is proposed aimed at substantially reducing the minimal
+magnetization switching field for a Stoner particle. Unlike the normal method
+of applying a static magnetic field which must be larger than the magnetic
+anisotropy, a much weaker field, proportional to the damping constant in the
+weak damping regime, can be used to switch the magnetization from one state to
+another if the field is along the motion of the magnetization. The concept is
+to constantly supply energy to the particle from the time-dependent magnetic
+field to allow the particle to climb over the potential barrier between the
+initial and the target states.",0511135v1
+2006-01-17,Electric field control of magnetization dynamics in ZnMnSe/ZnBeSe diluted-magnetic-semiconductor heterostructures,"We show that the magnetization dynamics in diluted magnetic semiconductors
+can be controlled separately from the static magnetization by means of an
+electric field. The spin-lattice relaxation (SLR) time of magnetic Mn2+ ions
+was tuned by two orders of magnitude by a gate voltage applied to n-type
+modulation-doped (Zn,Mn)Se/(Zn,Be)Se quantum wells. The effect is based on
+providing an additional channel for SLR by a two-dimensional electron gas
+(2DEG). The static magnetization responsible for the giant Zeeman spin
+splitting of excitons was not influenced by the 2DEG density.",0601383v1
+2006-02-03,X-ray magnetic circular dichroism study of Re 5d magnetism in Sr2CrReO6,"We have measured Re 5d spin and orbital magnetic moments in the ferrimagnetic
+double perovskite Sr2CrReO6 by X-ray magnetic circular dichroism at the L_{2,3}
+edges. In fair agreement with recent band-structure calculations [Vaitheeswaran
+et. al., Ref 1], at the Re site a large 5d spin magnetic moment of -0.68 mu_B
+and a considerable orbital moment of +0.25 mu_B have been detected. We found
+that the Curie temperature of the double perovskites A2BB'O6 scales with the
+spin magnetic moment of the 'non-magnetic' B' ion.",0602071v1
+2006-04-24,Observation of a transverse magnetization in the ordered phases of the pyrochlore magnet Gd2Ti2O7,"We have performed a detailed transverse magnetization study of the pyrochlore
+antiferromagnet Gd2Ti2O7. A transverse magnetization of about 10^{-3}M_{sat} is
+observed in the low-temperature ordered phases. These measurements result in
+the refinement of the Gd2Ti2O7 phase diagrams. Observation of a transverse
+magnetization indicates loss of the cubic symmetry in some of the magnetic
+phases and provides new information for a better understanding of the
+complicated magnetic ordering of Gd2Ti2O7.",0604544v1
+2006-07-05,Instabilities of switching processes in synthetic antiferromagnets,"It is shown that magnetic states and field-driven reorientation transitions
+in synthetic antiferromagnets crucially depend on contributions of higher-order
+anisotropies. A phenomenological macrospin model is derived to describe the
+magnetic states of two antiferromagnetically coupled magnetic thin film
+elements. The calculated phase diagrams show that magnetic states with
+out-of-plane magnetization, symmetric escaped spin-flop phases, exist in a
+broad range of the applied magnetic field. Due to the formation of such states
+and concomitant multidomain patterns, the switching processes in toggle
+magnetic random access memory devices (MRAM) can radically deviate from
+predictions within oversimplified models.",0607124v1
+2006-09-21,High Temperature Superconductivity - Magnetic Mechanisms,"A brief history is offered concerning the relation of magnetism to
+superconductivity, and the possibility that magnetic correlations are
+responsible for certain types of superconductors. A central focus is on high
+temperature cuprate superconductivity and the important question of whether its
+d-wave pairing is caused by antiferromagnetic or singlet correlations.
+Connected with this question is the much debated relation of the pseudogap
+phase to the superconducting phase, and whether lattice degrees of freedom are
+relevant or not.",0609559v1
+2007-02-07,Vacuum fluctuations and the spin current in mesoscopic structures with collinear magnetic order,"We show that in magnetic nanostructures with a homogeneous magnetic order,
+the equilibrium spin current can be nonzero. For example, this is the case of a
+wide magnetic ring with the magnetization along the ring axis. The physical
+reason of this effect is a variation of the orientation of anisotropy axis
+inducing a spin torque acting on the magnetic ions. The mechanism of the spin
+current generation is related to the quantum vacuum fluctuations in the
+magnetic system.",0702168v2
+2007-02-28,Non-collinear coupling between magnetic adatoms in carbon nanotubes,"The long range character of the exchange coupling between localized magnetic
+moments indirectly mediated by the conduction electrons of metallic hosts often
+plays a significant role in determining the magnetic order of low-dimensional
+structures. In addition to this indirect coupling, here we show that the direct
+exchange interaction that arises when the moments are not too far apart may
+induce a non-collinear magnetic order that cannot be characterized by a
+Heisenberg-like interaction between the magnetic moments. We argue that this
+effect can be manipulated to control the magnetization alignment of magnetic
+dimers adsorbed to the walls of carbon nanotubes.",0703007v1
+1995-09-27,Does Magnetic Charge Imply a Massive Photon ?,"In Abelian theories of monopoles the magnetic charge is required to be
+enormous. Using the electric-magnetic duality of electromagnetism it is argued
+that the existence of such a large, non-perturbative magnetic coupling should
+lead to a phase transition where magnetic charge is permanently confined and
+the photon becomes massive. The apparent masslessness of the photon could then
+be used as an argument against the existence of such a large, non-perturbative
+magnetic charge. Finally it is shown that even in the presence of this
+dynamical mass generation the Cabbibo-Ferrari formulation of magnetic charge
+gives a consistent theory.",9509157v1
+1997-04-05,Can Magnetic Charge and Quantum Mechanics Co-exist ?,"It is proven that if more than a single magnetic charge exists it is
+impossible to define a proper quantum mechanical angular momentum operator for
+an electrically charged particle in the field of the magnetic charges. Assuming
+that quantum mechanics is correct we conclude that free magnetic charges (i.e.
+magnetic charges with a Coulomb-like magnetic field) can not exist. The only
+apparent way to avoid this conclusion is if magnetic charges do exist, they
+must be permanently confined in monopole anti-monopole pairs, much in the same
+way quarks are thought to be confined.",9704042v2
+2006-09-06,Magnetization-induced optical second-harmonic generation and local surface plasmons in magnetic $Co_x Ag_{1-x}$ nanogranular films,"Spectroscopy of magnetization-induced second-harmonic generation (MSHG) is
+studied in magnetic Co$_{x}$Ag$_{1-x}$ granular films containing Co
+nanoparticles. A strong resonance of the magnetic contrast of the
+second-harmonic generation (SHG) intensity is observed in the two-photon energy
+range from 3,8 eV to 4,5 eV. The local surface plasmons exited in magnetic Co
+nanogranules in this spectral range assist MSHG and are responsible for a
+significant enhancement of the SHG magnetic contrast due to the resonances of
+local optical fields.",0609010v1
+2005-01-26,Destroying the superfluid state of fermionic atoms by the magnetic field in Feshbach resonance experiments,"We show that the superfluid state (SF) of fermionic atoms exist only for the
+magnetic fields lesser than the critical magnetic field. This critical magnetic
+field is determined by the equality of the Zeeman energy splitting for atoms
+with different spin projections to the energy gap of fermionic atoms without a
+magnetic field. For magnetic fields usually using in Feshbach resonance
+experiments a SF state is lost because these fields are much more than the
+critical field. We show that the transition temperature $ T_c $ of the SF state
+decreases as the magnetic field increases.",0501137v1
+2006-05-03,Effect of Magnetization Inhomogeneity on Magnetic Microtraps for Atoms,"We report on the origin of fragmentation of ultracold atoms observed on a
+permanent magnetic film atom chip. A novel technique is used to characterize
+small spatial variations of the magnetic field near the film surface using
+radio frequency spectroscopy of the trapped atoms. Direct observations indicate
+the fragmentation is due to a corrugation of the magnetic potential caused by
+long range inhomogeneity in the film magnetization. A model which takes into
+account two-dimensional variations of the film magnetization is consistent with
+the observations.",0605028v2
+2006-08-03,Magnetization of rotating ferrofluids: the effect of polydispersity,"The influence of polydispersity on the magnetization is analyzed in a
+nonequilibrium situation where a cylindrical ferrofluid column is enforced to
+rotate with constant frequency like a rigid body in a homogeneous magnetic
+field that is applied perpendicular to the cylinder axis. Then, the
+magnetization and the internal magnetic field are not longer parallel to each
+other and their directions differ from that of the applied magnetic field.
+Experimental results on the transverse magnetization component perpendicular to
+the applied field are compared and analyzed as functions of rotation frequency
+and field strength with different polydisperse Debye models that take into
+account the polydispersity in different ways and to a varying degree.",0608033v1
+2007-07-02,Manipulating the magnetic structure by electric fields in multiferroic ErMn2O5,"Based on measurements of soft x-ray magnetic diffraction under in-situ
+applied electric field, wereport on significantly manipulation and exciting of
+commensurate magnetic order in multiferroic ErMn2O5. The induced magnetic
+scattering intensity arises at the commensurate magnetic Bragg position whereas
+the initial magnetic signal almost persists. We demonstrate the possibility to
+imprint a magnetic response function in ErMn2O5 by applying electric field.",0707.0180v2
+2007-10-02,Magnetic relaxation in the Bianchi-I universe,"Extended Einstein-Maxwell model and its application to the problem of
+evolution of magnetized Bianchi-I Universe are considered. The evolution of
+medium magnetization is governed by a relaxation type extended constitutive
+equation. The series of exact solutions to the extended master equations is
+obtained and discussed. The anisotropic expansion of the Bianchi-I Universe is
+shown to become non-monotonic (accelerated/decelerated) in both principal
+directions (along the magnetic field and orthogonal to it). A specific type of
+expansion, the so-called evolution with hidden magnetic field, is shown to
+appear when the magnetization effectively screens the magnetic field and the
+latter disappears from the equations for gravitational field.",0710.0615v1
+2007-10-19,Depressed Surface Magnetization in Thin La0.8MnO3 Films,"A systematic study the magnetization in La0.8.MnO3 films of thickness varying
+from ultra-thin to bulk-like has been conducted. The study reveals suppression
+of the bulk magnetization for films up to at least 1600 A. In addition, the
+surface (top 50 A) of all films exhibits depressed magnetization as observed by
+x-ray magnetic circular dichroism (XMCD). The reduced surface magnetization is
+attributed to the coexistence of magnetic and nonmagnetic components of the
+same chemical composition.",0710.3793v1
+2007-11-19,Room Temperature Magnetocaloric Effect in Ni-Mn-In,"We have studied the effect of magnetic field on a non-stoichiometric Heusler
+alloy Ni$_{50}$Mn$_{35}$In$_{15}$ that undergoes a martensitic as well as a
+magnetic transition near room temperature. Temperature dependent magnetization
+measurements demonstrate the influence of magnetic field on the structural
+phase transition temperature. From the study of magnetization as a function of
+applied field, we show the occurrence of inverse-magnetocaloric effect
+associated with this magneto-structural transition. The magnetic entropy change
+attains a value as high as 25 J/kg-K (at 5 T field) at room temperature as the
+alloy transforms from the austenitic to martensitic phase with a concomitant
+magnetic ordering.",0711.2896v1
+2008-03-26,The commensurate phase of multiferroic HoMn2O5 studied by X-ray magnetic scattering,"The commensurate phase of multiferroic HoMn2O5 was studied by X-ray magnetic
+scattering, both off resonance and in resonant conditions at the Ho-L3 edge.
+Below 40 K, magnetic ordering at the Ho sites is induced by the main Mn
+magnetic order parameter, and its temperature dependence is well accounted for
+by a simple Curie-Weiss susceptibility model. A lattice distortion of
+periodicity twice that of the magnetic order is also evidenced. Azimuthal scans
+confirm the model of the magnetic structure recently refined from neutron
+diffraction data for both Mn and Ho sites, indicating that the two sublattices
+interact via magnetic superexchange.",0803.3779v1
+2008-09-11,Ferromagnetic ordering in dilute magnetic dielectrics with and without free carriers,"The state of art in the theoretical and experimental studies of transition
+metal doped oxides (dilute magnetic dielectrics) is reviewed. The available
+data show that the generic non-equilibrium state of oxide films doped with
+magnetic impurities may either favor ferromagnetism with high Curie temperature
+or result in highly inhomogeneous state without long-range magnetic order. In
+both case concomitant defects (vacancies, interstitial ions play crucial part.",0809.2005v1
+2008-10-28,"Anomalous magnetization behavior in Ce(Fe,Si)2","We report the effect of Si doping on the magnetization behavior of CeFe2. It
+is found that Si stabilizes the dynamic antiferromagnetic state of CeFe2.
+Multi-step magnetization behavior, unusual relaxation effect, thermal and
+magnetic history dependence, which are signatures of martensitic scenario, are
+found to be present in this system. We also show that one can induce the
+magnetization steps with the help of appropriate measurement protocol. Detailed
+magnetization relaxation studies have been carried out to understand the
+dynamics of magnetic phase transition.",0810.5017v1
+2008-10-29,Contrasting the magnetic response between magnetic-glass and reentrant spin-glass,"Magnetic-glass is a recently identified phenomenon in various classes of
+magnetic systems undergoing a first order magnetic phase transition. We shall
+highlight here a few experimentally determined characteristics of
+magnetic-glass and the relevant set of experiments, which will enable to
+distinguish a magnetic-glass unequivocally from the well known phenomena of
+spin-glass and reentrant spin-glass.",0810.5215v2
+2009-01-13,Magnetic field observations of low-mass stars,"Direct measurements of magnetic fields in low-mass stars of spectral class M
+have become available during the last years. This contribution summarizes the
+data available on direct magnetic measurements in M dwarfs from Zeeman analysis
+in integrated and polarized light. Strong magnetic fields at kilo-Gauss
+strength are found throughout the whole M spectral range, and so far all field
+M dwarfs of spectral type M6 and later show strong magnetic fields. Zeeman
+Doppler images from polarized light find weaker fields, which may carry
+important information on magnetic field generation in partially and fully
+convective stars.",0901.1719v1
+2009-01-19,Toroidal moments as indicator for magneto-electric coupling: the case of BiFeO_3 versus FeTiO_3,"In this paper we present an analysis of the magnetic toroidal moment and its
+relation to the various structural modes in R3c-distorted perovskites with
+magnetic cations on either the perovskite A or B site. We evaluate the toroidal
+moment in the limit of localized magnetic moments and show that the full
+magnetic symmetry can be taken into account by considering small induced
+magnetic moments on the oxygen sites. Our results give a transparent picture of
+the possible coupling between magnetization, electric polarization, and
+toroidal moment, thereby highlighting the different roles played by the various
+structural distortions in multiferroic BiFeO_3 and in the recently discussed
+isostructural material FeTiO_3, which has been predicted to exhibit electric
+field-induced magnetization switching.",0901.2812v1
+2009-01-28,"Concurrent Magnetic and Metal-Insulator Transitions in (Eu,Sm)B_6 Single Crystals","The effects of magnetic doping on a EuB_6 single crystal were investigated
+based on magnetic and transport measurements. A modest 5% Sm substitution for
+Eu changes the magnetic and transport properties dramatically and gives rise to
+concurrent antiferromagnetic and metal-insulator transitions (MIT) from
+ferromagnetic MIT for EuB6. Magnetic doping simultaneously changes the
+itinerant carrier density and the magnetic interactions. We discuss the origin
+of the concurrent magnetic MIT in (Eu,Sm)B_6.",0901.4384v1
+2009-02-03,Tuning Magnetic Avalanches in Mn12-ac,"Using micron-sized Hall sensor arrays to obtain time-resolved measurements of
+the local magnetization, we report a systematic study in the molecular magnet
+Mn$_{12}$-acetate of magnetic avalanches controllably triggered in different
+fixed external magnetic fields and for different values of the initial
+magnetization. The speeds of propagation of the spin-reversal fronts are in
+good overall agreement with the theory of magnetic deflagration of Garanin and
+Chudnovsky \cite{Garanin}.",0902.0531v2
+2009-03-25,Two dimensional frustrated magnets in high magnetic field,"Frustrated magnets in high magnetic field have a long history of offering
+beautiful surprises to the patient investigator. Here we present the results of
+extensive classical Monte Carlo simulations of a variety of models of two
+dimensional magnets in magnetic field, together with complementary spin wave
+analysis. Striking results include (i) a massively enhanced magnetocaloric
+effect in antiferromagnets bordering on ferromagnetic order, (ii) a route to an
+$m=1/3$ magnetization plateau on a square lattice, and (iii) a cascade of phase
+transitions in a simple model of AgNiO$_2$.",0903.4370v1
+2009-04-07,Unconventional magnetism in small gold organic molecules,"We present a theoretical study of the magnetic properties of
+dicyclopentadienyl metallocene and phthalocyanine molecules, that contain the
+transition metal atoms M = Fe, Co, Ni, Cu, Zn, Ir, Pt and Au. Our most
+important prediction is that gold and copper molecules are magnetic. We find
+that the magnetism of these molecules is fairly unconventional: the gold atom
+itself is weakly magnetic or even non-magnetic. Its role is rather to induce
+magnetism in the surrounding carbon and nitrogen atoms, producing a sort of
+spin density wave.",0904.1138v1
+2009-05-02,Voltage-assisted Magnetization Switching in Ultrathin Fe80Co20 Alloy Layers,"Growing demands for the voltage-driven spintronic applications with
+ultralow-power consumption have led to new interest in exploring the
+voltage-induced magnetization switching in ferromagnetic metals. In this study,
+we observed a large perpendicular magnetic anisotropy change in Au(001) /
+ultrathin Fe80Co20(001) / MgO(001) / Polyimide / ITO junctions, and succeeded
+in realizing a clear switching of magnetic easy axis between in-plane and
+perpendicular directions. Furthermore, employing a perpendicularly magnetized
+film, voltage-induced magnetization switching in the perpendicular direction
+under the assistance of magnetic fields was demonstrated. These pioneering
+results may open a new window of electric-field controlled spintronics devices.",0905.0185v1
+2009-06-26,Relaxation Mechanism for Ordered Magnetic Materials,"We have formulated a relaxation mechanism for ferrites and ferromagnetic
+metals whereby the coupling between the magnetic motion and lattice is based
+purely on continuum arguments concerning magnetostriction. This theoretical
+approach contrasts with previous mechanisms based on microscopic formulations
+of spin-phonon interactions employing a discrete lattice. Our model explains
+for the first time the scaling of the intrinsic FMR linewidth with frequency,
+and 1/M temperature dependence and the anisotropic nature of magnetic
+relaxation in ordered magnetic materials, where M is the magnetization. Without
+introducing adjustable parameters our model is in reasonable quantitative
+agreement with experimental measurements of the intrinsic magnetic resonance
+linewidths of important class of ordered magnetic materials, insulator or
+metals.",0906.4979v1
+2009-07-10,Quantized magnetic confinement in quantum wires,"Ballistic quantum wires are exposed to longitudinal profiles of perpendicular
+magnetic fields composed of a spike (magnetic barrier) and a homogeneous part.
+An asymmetric magnetoconductance peak as a function of the homogeneous magnetic
+field is found, comprising quantized conductance steps in the interval where
+the homogeneous magnetic field and the magnetic barrier have identical
+polarities, and a characteristic shoulder with several resonances in the
+interval of opposite polarities. The observations are interpreted in terms of
+inhomogeneous diamagnetic shifts of the quantum wire modes leading to magnetic
+confinement.",0907.1802v1
+2009-07-28,Chiral Magnetic conductivity,"Gluon field configurations with nonzero topological charge generate
+chirality, inducing P- and CP-odd effects. When a magnetic field is applied to
+a system with nonzero chirality, an electromagnetic current is generated along
+the direction of the magnetic field. The induced current is equal to the Chiral
+Magnetic conductivity times the magnetic field. In this article we will compute
+the Chiral Magnetic conductivity of a high-temperature plasma for nonzero
+frequencies. This allows us to discuss the effects of time-dependent magnetic
+fields, such as produced in heavy ion collisions, on chirally asymmetric
+systems.",0907.5007v1
+2010-05-15,Thermodynamics of strongly frustrated magnet in a field: Ising antiferromagnet on triangular Husimi lattice,"Some strongly frustrated magnets such as the ""spin-ice"" compounds fail to
+produce any magnetic order at finite temperatures even in the presence of
+magnetic field. Still they have very unusual low-temperature thermodynamic
+properties related to the field-induced ground state transitions. Here we show
+that general qualitative picture of such peculiar thermodynamics can be
+obtained in the antiferromagnetic Ising model on the triangular Husimi lattice.
+The analytical results for this model show magnetic plateaus, entropy spikes,
+crossing points and peculiarities in magnetic susceptibility and specific heat
+behavior reflecting the existence of ground state transitions. These signatures
+of strong frustration may help in search of new frustrated magnets and in the
+interpretation of experimental data.",1005.2650v1
+2010-05-17,Quantization of edge currents along magnetic barriers and magnetic guides,"We investigate the edge conductance of particles submitted to an Iwatsuka
+magnetic field, playing the role of a purely magnetic barrier. We also consider
+magnetic guides generated by generalized Iwatsuka potentials. In both cases we
+prove quantization of the edge conductance. Next, we consider magnetic
+perturbations of such magnetic barriers or guides, and prove stability of the
+quantized value of the edge conductance. Further, we establish a sum rule for
+edge conductances. Regularization within the context of disordered systems is
+discussed as well.",1005.2788v1
+2010-07-02,Spin-polarizing properties of heterostructures with magnetic nano elements,"The problem of electron resonant and non-resonant scatterings on two
+magnetized barriers is studied in the one-dimension. The transfer-matrix is
+built up to exactly calculate the coefficient of the electron transmittance
+through the system of two magnetic barriers with non-collinear magnetizations.
+The polarization of the transmitted electron wave for resonance and
+non-resonance transmittances is calculated. The transmittance coefficient and
+spin polarization can be drastically enhanced and controlled by the angle
+between the barrier magnetizations",1007.0421v1
+2010-09-22,Direct Measurement of Effective Magnetic Diffusivity in Turbulent Flow of Liquid Sodium,"The first direct measurements of effective magnetic diffusivity in turbulent
+flow of electro-conductive fluids (the so-called beta-effect) under magnetic
+Reynolds number Rm >> 1 are reported. The measurements are performed in a
+nonstationary turbulent flow of liquid sodium, generated in a closed toroidal
+channel. The peak level of the Reynolds number reached Re \approx 3 10^6, which
+corresponds to the magnetic Reynolds number Rm \approx 30. The magnetic
+diffusivity of the liquid metal was determined by measuring the phase shift
+between the induced and the applied magnetic fields. The maximal deviation of
+magnetic diffusivity from its basic (laminar) value reaches about 50% .",1009.4333v1
+2010-11-03,Critical Magnetic Field Ratio of Anisotropic Magnetic Superconductors,"The upper critical field, the lower critical field and the critical magnetic
+field ratio of anisotropic magnetic superconductors are calculated by
+Ginzburg-Landau theory analytically. The effect of the Ginzburg-Landau
+parameter(\kappa_0), magnetic susceptibility(\chi) and magnetic-to- anisotropic
+parameter ratio(\theta) on the critical field ratio are considered. We find
+that the value of critical magnetic field ratio with \chi < 0, higher
+\kappa_0,and higher \theta case are shown the higher value. And, the
+diamagnetic superconductors with highly anisotropic and the ferromagnetic
+superconductors are shown the highest and the lowest, respectively.",1011.0783v1
+2010-11-18,Possibility of exchange switching ferromagnet - antiferromagnet junctions,"Current flowing is studied in magnetic junctions consisting of a
+ferromagnetic metal (FM), antiferromagnetic conductor (AFM) and a nonmagnetic
+metal closing the electric circuit. The FM layer with high anisotropy and
+pinned spins of the magnetic atoms in the lattice acts as a spin injector
+relative to the AFM layer. To obtain resulting magnetization in the AFM layer,
+magnetic field is applied, which may be varied to control the magnetization.
+The spin-polarized current from the FM layer creates a torque and makes it
+possible to switch the magnetization. A possibility is shown to lower the
+threshold current density by the orders of magnitude by means of the magnetic
+field.",1011.4303v1
+2010-12-03,Magnetic Field Structure near the Galactic Plane,"We bring the two color maps for the plane component magnetic field of our
+Galaxy in coordinates of (R;l) and (DM;l). It was shown that magnetic field has
+reversals of the direction in neighbor spiral arms, in agreement with known
+models for the Galactic magnetic field. For the Sagittarius spiral arm region
+there is, however, some disagreement with standard magnetic field models. The
+major discrepancy is the fact that in the Sagittarius arm region the magnetic
+field in Southern hemisphere of the Galaxy, have opposite direction to the
+field of the Northern hemisphere. We think that the Sagittarius spiral arm, at
+last the magnetic spiral arm in this region is not symmetric to the Galactic
+plane, and is located mainly in Northern hemisphere.",1012.0646v1
+2011-01-20,Controllable manipulation of superconductivity using magnetic vortices,"The magneto-transport of a superconducting/ferromagnetic hybrid structure
+consisting of a superconducting thin film in contact with an array of magnetic
+nanodots in the so-called ""magnetic vortex-state"" exhibits interesting
+properties. For certain magnetic states, the stray magnetic field from the
+vortex array is intense enough to drive the superconducting film into the
+normal state. In this fashion, the normal-to-superconducting phase transition
+can be controlled by the magnetic history. The strong coupling between
+superconducting and magnetic subsystems allows characteristically ferromagnetic
+properties, such as hysteresis and remanence, to be dramatically transferred
+into the transport properties of the superconductor.",1101.3846v1
+2011-03-09,"Specifications, quality control, manufacturing, and testing of accelerator magnets","The performance of the magnets plays an important role in the functioning of
+an accelerator. Most of the magnets are designed at the accelerator laboratory
+and built by industry. The link between the laboratory and the manufacturer is
+the contract containing the Technical Specifications of the magnets. For an
+overview of the contents of the Technical Specifications, the specifications
+for the magnets of ALBA (bending, quadrupole, and sextupole) are described in
+this paper. The basic rules of magnet design are reviewed in Appendix A.",1103.1815v1
+2011-06-12,Anomalies in the Multicritical Behavior of Staggered Magnetic and Direct Magnetic Susceptibilities of Iron Group Dihalides,"In this study, the temperature dependencies of magnetic response functions of
+the anhydrous dihalides of iron-group elements are examined in the neighborhood
+of multi-critical points (tricritical, critical end point, double critical end
+point) and first order transition temperatures within molecular field
+approximation. Our findings reveal the fact that metamagnetic Ising system
+exhibits anomalies in the temperature dependence of the magnetic response
+functions for r<0.3. In addition, we extensively investigated how an inter- and
+intra-layer exchange interaction ratio can influence magnetic response
+properties of these systems. Finally, a comparison is made with related works.",1106.2308v1
+2011-07-08,Ferromagnetism in lead graphite-pencils and magnetic composite with CoFe2O4 particles,"This work has been initiated with a curiosity to investigate the elemental
+composition and magnetic response of different grades of lead pencils (6B, 2B,
+HB, 2H, 5H) that people use in daily life. Interestingly, experimental results
+landed with a great achievement of observing soft magnetism in lead pencils,
+indicating a wide scope of magnetic tuning for room temperature applications. A
+novel magnetic composite has been synthesized by mixing different concentration
+of CoFe2O4 (CF) nanoparticles in 5H and 6B pencils for studying the magnetic
+tailoring aspects using pencils. Our results showed different possibilities of
+controlling disorder induced ferromagnetic parameters and a simple approach of
+producing sufficiently high coercive magnetic composite using pencils.",1107.1662v1
+2011-11-01,Measurement of magnetic permeability of steel laminations of Booster gradient magnets,"New experiments at Fermilab require higher beam intensities at Booster,
+resulting in higher influence of magnet steel on the beam. In order to
+carefully take these effects into account it is necessary to know geometric and
+material properties of magnets. This work is dedicated to the measurement of
+magnetic permeability of steel laminations of Booster gradient magnets as a
+complex function of frequency in the frequency range from several megahertz up
+to 1 GHz. The magnetic permeability is estimated by analyzing S-parameters of
+microstrip lines made up from laminated steel.",1111.0247v3
+2011-11-28,Magnetic stars from a FEROS cool Ap star survey,"New magnetic Ap stars with split Zeeman components are presented. These stars
+were discovered from observations with the FEROS spectrograph at the ESO 2.2-m
+telescope. Fifteen new magnetic stars are analysed here. Several stars with
+very strong magnetic fields were found, including HD\,70702 with a 15-kG, and
+HD\,168767 with a 16.5-kG magnetic field strength measured using split Zeeman
+components of spectral lines and by comparison with synthetic calculations. The
+physical parameters of the stars were estimated from photometric and
+spectroscopic data. Together with previously published results for stars with
+strong magnetic fields, the relationship between magnetic field strength and
+rotation period is discussed.",1111.6448v1
+2011-12-08,Spintronic devices on the base of magnetic nanostructures,"Two types of spintronic devices on the base of magnetic nanostructures
+containing silicon dioxide films with cobalt nanoparticles SiO2(Co) on GaAs
+substrate - magnetic sensors and field-effect transistor governed by applied
+magnetic field - are studied. Magnetic sensors are based on the injection
+magnetoresistance effect. This effect manifests itself in avalanche suppression
+by the magnetic field in GaAs near the SiO2(Co)/GaAs interface. Field-effect
+transistor contains the SiO2(Co) film under gate. It is found that the magnetic
+field action leads to great changes in electron mobility in the channel due to
+the interaction between spins of Co nanoparticles and electron spins.",1112.1798v1
+2012-01-10,Direct observation of magnetic phase coexistence and magnetization reversal in a Gd$_{0.67}$Ca$_{0.33}$MnO$_{3}$ thin film,"We have investigated the ferrimagnetic domain structure in a
+Gd$_{0.67}$Ca$_{0.33}$MnO$_{3}$ thin film using magnetic force microscopy. We
+observe clear signs of phase separation, with magnetic islands embedded in a
+non-magnetic matrix. We also directly visualize the reversal of magnetization
+of ferrimagnetic domains as a function of temperature and attribute it to a
+change in the balance of magnetization of anti-aligned Mn and Gd sublattices.",1201.2144v1
+2012-05-14,Effects of the randomly distributed magnetic field on the phase diagrams of the Ising Nanowire I: discrete distributions,"The effect of the random magnetic field distribution on the phase diagrams
+and ground state magnetizations of the Ising nanowire is investigated with
+effective field theory with correlations. Trimodal distribution chosen as a
+random magnetic field distribution. The variation of the phase diagrams with
+that distribution parameters obtained and some interesting results found such
+as reentrant behavior. Also for the trimodal distribution, ground state
+magnetizations for different distribution parameters determined which can be
+regarded as separate partially ordered phases of the system.",1205.3219v1
+2012-06-06,Magnetic field dependent impact ionization in InSb,"Carrier generation by impact ionization and subsequent recombination under
+the influence of magnetic field has been studied for InSb slab. A simple
+analytic expression for threshold electric field as a function of magnetic
+field is proposed. Impact ionization is suppressed by magnetic field. However,
+surface recombination is dependent on the polarity of magnetic field:
+strengthened in one direction and suppressed on the opposite direction. The
+former contributes quadratic increase to threshold electric field, and the
+latter gives additional linear dependence on magnetic field. Based on this
+study, electrical switching devices driven by magnetic field can be designed.",1206.1094v1
+2012-08-28,Thermodynamic investigations in the precursor region of FeGe,"High-resolution DC magnetization and AC-specific heat data of the cubic
+helimagnet FeGe have been measured as function of temperature and magnetic
+field. The magnetization data as well as the isothermal susceptibility data
+confirm the complexity of the magnetic phase diagram in the vicinity of the
+onset of long-rang magnetic order (Tc = 278.5 K) and the existence of a
+segmented A-phase region. Moreover, these data revealed independent and clear
+indications of phase boundaries and crossovers within the A-phase region.
+Together with the anomalies in the specific-heat data around Tc and at small
+magnetic fields (H < 600 Oe) a complex magnetic phase diagram of FeGe is
+obtained.",1208.5646v1
+2012-09-17,Size and polydispersity effect on the magnetization of densely packed magnetic nanoparticles,"The magnetic properties of densely packed magnetic nanoparticles (MNP)
+assemblies are investigated from Monte Carlo simulations. The case of iron
+oxide nanoparticles is considered as a typical example of MNP. The main focus
+is put on particle size and size polydispersity influences on the magnetization
+curve. The particles are modeled as uniformly magnetized spheres isolated one
+from each other by a non magnetic layer representing the organic coating. A
+comparison with recent experimental results on $\gamma-$Fe$_2$O$_3$ powder
+samples differing by their size is given.",1209.3566v1
+2012-11-02,Effect of Spin Torque on Magnetization Switching Speed Having Nonuniform Spin Distribution,"We study the influence of the spin torque, which depends on the space and
+time derivative of magnetization, on magnetization reversal time in a
+ferromagnetic fine particle. The spin torque operates to dissipate the angular
+momentum of the magnetization precession, and the torque increases in a spin
+vortex structure. We calculate the magnetization reversal time under a DC
+magnetic field using the Landau-Lifshitz-Gilbert equation containing a spin
+torque term. We found that the spin torque changes the magnetization switching
+speed significantly during the reversal process by maintaining a spin vortex in
+an intermediate state.",1211.0360v1
+2012-11-06,Spin Wave Scattering in Ferromagnetic Cross,"Spin wave scattering in the right angle ferromagnetic cross was measured.
+Shape anisotropy defined magnetization ground states at zero biasing magnetic
+fields. Scattering of the spin waves in the center of ferromagnetic cross is
+strongly dependent on the amplitude and angle of the biasing magnetic field.
+Micromagnetic simulations indicate that low in-plane biasing magnetic fields
+rotate the magnetization of the cross center while the arms stay axially
+magnetized due to the shape anisotropy. We discuss effect of biasing magnetic
+fields on the spin wave scattering and approaches to an effective spin wave
+switch based on the fabricated structure.",1211.1259v1
+2012-11-23,Non-reciprocal light diffraction by a vortex magnetic particle,"We report a theoretical study of light diffraction by a spherical magnetic
+particle with a vortex magnetization distribution. It is shown that the
+intensity of the diffracted light involves a non-reciprocal contribution. This
+contribution depends on the vorticity of particle magnetization. It appears due
+to the excitation of an electric quadrupole, magnetic dipole and the addition
+to the electric dipole moment in the particle, that depend on the particle
+magnetization vorticity. The estimation of the non-reciprocal contrbution for a
+cobalt particle and two linear polarizations of the incident light fits the
+data of recent experimental studies in the lattice of triangle magnetic
+particles by an order of magnitude.",1211.5459v1
+2012-12-05,"Influence of Magnetic Anisotropy on Laser-induced Precession of Magnetization in Ferromagnetic Semiconductor (Ga,Mn)As","The laser-induced precession of magnetization in (Ga,Mn)As samples with
+different magnetic anisotropy was studied by the time-resolved magneto-optical
+method. We observed that the dependence of the precession amplitude on the
+external magnetic field depends strongly on the magnetic anisotropy of
+(Ga,Mn)As and we explain this phenomenon in terms of competing cubic and
+uniaxial anisotropies. We also show that the corresponding anisotropy fields
+can be deduced from the magnetic field dependence of the precession frequency.",1212.0962v1
+2013-06-13,Temperature- and Magnetic-Field-Tuning of Magnetic Phases in Multiferroic NdFe3(BO3)4,"We report the low-temperature coexistence in NdFe3(BO3)4 of an incommensurate
+magnetic phase with a strained commensurate magnetic phase that is primarily at
+the surface of the crystal. Increasing the temperature or magnetic field
+decreases the incommensurability and stabilizes the commensurate magnetic phase
+above Tic ~14 K or Hic = 0.9 T. A comparison to published studies indicates the
+onset of longitudinal magnetostriction and electric polarization at the
+magnetic-field-induced transition, which may arise due to a basal plane
+spin-flop and canting of the moments along the field direction.",1306.3152v1
+2013-07-10,Spintronic Oscillator Based on Magnetic Field Feedback,"We present a circuit design of a spintronic oscillator based on magnetic
+tunnel junction. In this design, a dc current is passed through a magnetic
+tunnel junction which is connected to a feed-back wire below it. Any
+fluctuation in the magnetization direction of the free layer of MTJ, drives a
+fluctuating current through the feed-back wire, which exerts a magnetic field
+on the free layer. This in turn can amplify the magnetization fluctuations of
+the free layer. If the dc current passing through the MTJ is more than a
+critical value, continuous precessing states of the magnetization are possible.",1307.2744v1
+2013-07-19,X-ray diffraction by magnetic charges (monopoles),"Magnetic charges, or magnetic monopoles, may form in the electronic structure
+of magnetic materials where ions are deprived of symmetry with respect to
+spatial inversion. Predicted in 2009, the strange magnetic, pseudoscalars have
+recently been found different from zero in simulations of electronic structures
+of some magnetically ordered, orthorhombic, lithium orthophosphates (LiMPO4).
+We prove that magnetic charges in lithium orthophosphates diffract x-rays tuned
+in energy to an atomic resonance, and to guide future experiments we calculate
+appropriate unit-cell structure factors for monoclinic LiCoPO4 and orthorhombic
+LiNiPO4.",1307.5164v1
+2013-07-31,External magnetic fields and the chiral phase transition in QED at nonzero chemical potential,"Inspired by recent discussions of inverse magnetic catalysis in the
+literature, we examine the effects of a uniform external magnetic field on the
+chiral phase transition in quenched ladder QED at nonzero chemical potential.
+In particular, we study the behaviour of the effective potential as the
+strength of the magnetic field is varied while the chemical potential is held
+constant. For a certain range of the magnetic field, the effective potential
+develops a local maximum. Inverse magnetic catalysis is observed at this
+maximum, whereas the usual magnetic catalysis is observed at the true minimum
+of the effective potential.",1307.8222v1
+2013-09-24,Magnetic fields in A stars besides Ap stars,"I review ongoing efforts to understand the incidence of magnetism in
+intermediate-mass stars that are different from the magnetic Ap stars. This
+includes the search for magnetic fields in chemically peculiar stars of the Am
+and HgMn types as well as in normal A and late-B stars. I discuss different
+techniques for detection of weak stellar magnetic fields and present a critical
+evaluation of the recent magnetic detections in non-Ap stars. Special attention
+is given to the magnetic status of HgMn stars and to the discovery of weak
+polarization signatures in Sirius and Vega.",1309.6313v1
+2013-10-22,Magnetic Fields in Low-mass Stars: An Overview of Observational Biases,"Stellar magnetic dynamos are driven by rotation, rapidly rotating stars
+produce stronger magnetic fields than slowly rotating stars do. The Zeeman
+effect is the most important indicator of magnetic fields, but Zeeman
+broadening must be disentangled from other broadening mechanisms, mainly
+rotation. The relations between rotation and magnetic field generation, between
+Doppler and Zeeman line broadening, and between rotation, stellar radius, and
+angular momentum evolution introduce several observational biases that affect
+our picture of stellar magnetism. In this overview, a few of these relations
+are explicitly shown, and the currently known distribution of field
+measurements is presented.",1310.5820v1
+2013-11-01,Magnetic Generation due to Mass Difference between Charge Carriers,"The possibility of spontaneous magnetization due to the ""asymmetry in mass""
+of charge carriers in a system is investigated. Analysis shows that when the
+masses of positive and negative charge carriers are identical, no magnetization
+is predicted. However, if the masses of two species are different, spontaneous
+magnetic field would appear, either due to the equipartition of magnetic energy
+or due to fluctuations together with a feedback mechanism. The conditions for
+magnetization to occur are also obtained, in the form of n-T phase diagram. The
+theory proposed here, if confirmed by future observations and/or experiments,
+would provide a new insight on the origin of magnetic fields in the universe.",1311.0074v1
+2014-01-08,Increasing the magnetic sensitivity of liquid crystals by rod-like magnetic nanoparticles,"Magnetic Fr\'eedericksz transition was studied in ferronematics based on the
+nematic liquid crystal 4-(trans-4'-n-hexylcyclohexyl)-isothiocyanatobenzene
+(6CHBT). 6CHBT was doped with rod-like magnetic particles of different size and
+volume concentration. The volume concentrations of magnetic particles in the
+prepared ferronematics were $\phi_1$ = 10$^{-4}$ and $\phi_2$ = 10$^{-3}$. The
+structural changes were observed by capacitance measurements that demonstrate a
+significant influence of the concentration, the shape anisotropy, and/or the
+size of the magnetic particles on the magnetic response of these ferronematics.",1401.1695v1
+2014-01-16,"Quench protection analysis in accelerator magnets, a review of the tools","As accelerator magnets see the increase of their magnetic field and stored
+energy, quench protection becomes a critical part of the magnet design. Due to
+the complexity of the quench phenomenon interweaving magnetic, electrical and
+thermal analysis, the use of numerical codes is a key component of the process.
+In that respect, we propose here a review of several tools commonly used in the
+magnet design community.",1401.3934v1
+2014-02-25,Magnetic field control of ferroelectric polarization and magnetization of LiCu2O2 compound,"A spin model of LiCu2O2 compound with ground state of ellipsoidal helical
+structure has been adopted. Taking into account the interchain coupling and
+exchange anisotropy, we focus on the magnetoelectric properties in a rotating
+magnetic field and perform the Monte Carlo simulation on a two-dimensional
+lattice. A prominent anisotropic response is observed in the magnetization and
+polarization curves, qualitatively coinciding with the behaviors that detected
+in the experiment. In addition, the influences of the magnetic field with
+various magnitudes are also explored and analyzed in detail. As the magnetic
+field increases, a much smoother polarization of angle dependence is exhibited,
+indicating the strong correlation between the magnetic and ferroelectric
+orders.",1402.6648v1
+2014-04-19,High-precision description and new properties of a spin-1 particle in a magnetic field,"The exact Foldy-Wouthuysen Hamiltonian is derived for a pointlike spin-1
+particle with a normal magnetic moment in a nonuniform magnetic field. For a
+uniform magnetic field, it is exactly separated into terms linear and quadratic
+in spin. New unexpected properties of a particle with an anomalous magnetic
+moment are found. Spin projections of a particle moving in a uniform magnetic
+field are not integer and the tensor polarization is asymmetric in the plane
+orthogonal to the field. Previously described spin-tensor effects caused by the
+tensor magnetic polarizability exist not only for nuclei but also for pointlike
+particles.",1404.4953v2
+2014-05-16,Magnetoelectric surface acoustic wave resonator with ultrahigh magnetic field sensitivity,"A magnetoelectric surface acoustic wave (MESAW) type device based on
+piezoelectric/magnetostrictive heterostructure was proposed to use as weak
+magnetic field sensor. Unlike conventional magnetoelectric bulk laminates or
+film stacks collecting magnetic field induced electrical charge, the MESAW
+detects the shift of the center frequency, which highly depends on the magnetic
+field due to the giant delta E effect and the phase velocity dispersion. The
+magnetic field sensitivity can reach 10^(-11) Tesla in consideration of 100 Hz
+frequency accuracy. Additionally, the unique working mechanism of MESAW allows
+a broadband detection of weak magnetic field even with no bias magnetic field.",1405.4076v2
+2014-05-22,Magnetic phases of erbium orthochromite,"Erbium orthochromite, ErCrO3, is a distorted-perovskite which has
+antiferromagnetic ground state below 10 K while Cr3+ magnetic moments order at
+133 K. The temperature dependence of magnetization is studied across different
+magnetic phases for ErCrO3 and different magnetization isotherms are analyzed.
+In the presence of external magnetic field, polycrystalline ErCrO3 develops
+weak ferromagnetism from antiferromagnetic ground state. These magnetic phase
+transitions are observed to be of first order which is justified by thermal
+hysteresis and Arrott-plots.",1405.5636v1
+2014-06-18,Spin-lattice coupling induced weak dynamical magnetism in EuTiO_3 at high temperatures,"EuTiO_3, which is a G-type antiferromagnet below T_N = 5.5 K, has some
+fascinating properties at high temperatures, suggesting that macroscopically
+hidden dynamically fluctuating weak magnetism exists at high temperatures. This
+conjecture is substantiated by magnetic field dependent magnetization
+measurements, which exhibit pronounced anomalies below 200 K becoming more
+distinctive with increasing magnetic field strength. Additional results from
+muon spin rotation (${\mu}$SR) experiments provide evidence for weak
+fluctuating bulk magnetism induced by spin-lattice coupling which is strongly
+supported in increasing magnetic field.",1406.4915v1
+2014-09-17,Terahertz Magnetic Modulator based on Magnetically-Clustered Nanoparticles,"Random orientation of liquid-suspended magnetic nanoparticles (Ferrofluid)
+gives rise to zero net magnetic orientation. An external magnetic field tends
+to align them into clusters, leading to a strong linear dichroism on a
+propagating wave. Using 10 nm-sized Fe3O4, we experimentally realize a
+polarization-sensitive magnetic modulator operating at terahertz wavelengths.
+We reached a modulation depth of 66% using a field of 35 mT. The proposed
+concept offers a solution towards fundamental terahertz magnetic modulators.",1409.4963v1
+2015-03-27,Spin superradiance by magnetic nanomolecules and nanoclusters,"Spin dynamics of assemblies of magnetic nanomolecules and nanoclusters can be
+made coherent by inserting the sample into a coil of a resonant electric
+circuit. Coherence is organized through the arising feedback magnetic field of
+the coil. The coupling of a magnetic sample with a resonant circuit induces
+fast spin relaxation and coherent spin radiation, that is, superradiance. We
+consider spin dynamics described by a realistic Hamiltonian, typical of
+magnetic nanomolecules and nanoclusters. The role of magnetic anisotropy is
+studied. A special attention is paid to geometric effects related to the mutual
+orientation of the magnetic sample and resonator coil.",1503.08036v1
+2015-04-05,Magnetic states in multiply-connected flat nano-elements,"Flat magnetic nano-elements are an essential component of current and future
+spintronic devices. By shaping an element it is possible to select and
+stabilize chosen metastable magnetic states, control its magnetization
+dynamics. Here, using a recent significant development in mathematics of
+conformal mapping, complex variable based approach to the description of
+magnetic states in planar nano-elements is extended to the case when elements
+are multiply-connected (that is, contain holes or magnetic anti-dots). We show
+that presence of holes implies a certain restriction on the set of magnetic
+states of nano-element.",1504.01162v1
+2015-04-28,"""Switching"" of Magnetic Anisotropy in a fcc Antiferromagnet with Direction-Dependent Interactions","Direction-dependent anisotropic exchange is a common feature of magnetic
+systems with strong spin-orbit coupling. Here we study the effect of such
+exchange upon macroscopic magnetic anisotropy for a face-centered-cubic model.
+By several theoretical techniques, we show that, both in the paramagnetic and
+ordered phases, the magnetic anisotropy is induced by fluctuations. Moreover,
+the magnetic anisotropy differs in the paramagnetic and ordered phases: in the
+paramagnetic phase the susceptibility is maximum along the $\langle111\rangle$
+directions, while the magnetic moments orient along $\langle110\rangle$ or
+$\langle100\rangle$ in the ordered phase. We suggest that such ""anisotropy
+switching"" can be a common feature of strongly spin-orbit coupled magnets.",1504.07607v1
+2015-07-20,On the Unique Reconstruction of Induced Spherical Magnetizations,"Recovering spherical magnetizations $m$ from magnetic field data in the
+exterior is a highly non-unique problem. A spherical Hardy-Hodge decomposition
+supplies information on what contributions of the magnetization $m$ are
+recoverable but it does not supply geophysically suitable constraints on $m$
+that would guarantee uniqueness for the entire magnetization. In this paper, we
+focus on the case of induced spherical magnetizations and show that uniqueness
+is guaranteed if one assumes that the magnetization is compactly supported on
+the sphere. The results are based on ideas presented in Baratchart et al.
+(2013) for the planar setting.",1507.07570v3
+2015-10-27,Evidence for a re-entrant character of magnetism of sigma-phase Fe-Mo alloys: non-linear susceptibilities,"Non-linear ac magnetic susceptibility terms viz. quadratic, chi2, and cubic,
+chi3, were measured versus temperature and frequency for a series of the
+sigma-phase Fe(100-x)Mo(x) (47<x<53) compounds. Clear evidence was found that
+the ground magnetic state of the samples is mixed i.e. constituted by two
+phases: a spin glass (SG) and a ferromagnet (FM), hence the magnetism of the
+investigated samples can be regarded as re-entrant (RSG). Based on the present
+data, previously reported magnetic phase diagram has been upgraded [J.
+Przewoznik, S. M. Dubiel,J. Alloy. Comp., 630 (2015) 222].",1510.07811v1
+2015-11-12,Influence of intermolecular interactions on magnetic observables,"Very often it is an implied paradigm of molecular magnetism that magnetic
+molecules in a crystal interact so weakly that measurements of dc magnetic
+observables reflect ensemble properties of single molecules. But the number of
+cases where the assumption of virtually non-interacting molecules does not hold
+grows steadily. A deviation from the non-interacting case can especially
+clearly be seen in clusters with antiferromagnetic couplings, where steps of
+the low-temperature magnetization curve are smeared out with increasing
+intermolecular interaction. In this investigation we demonstrate with examples
+in one-, two, and three space dimensions how intermolecular interactions
+influence typical magnetic observables such as magnetization, susceptibility
+and specific heat.",1511.03856v1
+2015-11-12,Magnetization switching by microwaves initially rotating in opposite direction to precession,"A common understanding of magnetization switching in microwave-assisted
+magnetization reversal is that the rotation direction of the microwaves should
+be the same with the precession direction of the magnetization. In this letter
+however, we show that microwaves initially rotating opposite to the
+magnetization precession destabilize the magnetization at an equilibrium and
+induces the switching more efficiently, when the microwave frequency depends on
+time. This argument is analytically deduced from energy balance equation. We
+also establish a model satisfying this condition, and confirm magnetization
+switching solely by microwaves by using numerical simulation.",1511.04051v1
+2016-01-22,Phenomenological Magnetic Model in Tsai-Type Approximants,"Motivated by recent discovery of canted ferromagnetism in Tsai-type
+approximants Au-Si-RE (RE = Tb, Dy, Ho), we propose a phenomenological magnetic
+model reproducing their magnetic structure and thermodynamic quantities. In the
+model, cubic symmetry ($m\bar{3}$) of the approximately-regular icosahedra
+plays a key role in the peculiar magnetic structure determined by a neutron
+diffraction experiment. Our magnetic model does not only explain magnetic
+behaviors in the quasicrystal approximants, but also provides a good starting
+point for the possibility of coexistence between magnetic long-range order and
+aperiodicity in quasicrystals.",1601.05905v1
+2016-01-23,Nonlinear magnetization dynamics of antiferromagnetic spin resonance induced by intense terahertz magnetic field,"We report on the nonlinear magnetization dynamics of a HoFeO3 crystal induced
+by a strong terahertz magnetic field resonantly enhanced with a split ring
+resonator and measured with magneto-optical Kerr effect microscopy. The
+terahertz magnetic field induces a large change (~40%) in the spontaneous
+magnetization. The frequency of the antiferromagnetic resonance decreases in
+proportion to the square of the magnetization change. A modified
+Landau-Lifshitz-Gilbert equation with a phenomenological nonlinear damping term
+quantitatively reproduced the nonlinear dynamics.",1601.06213v1
+2016-03-29,Switching local magnetization by electric-field-induced domain wall motion,"Electric field effect on magnetism is an appealing technique for manipulating
+the magnetization at a low cost of energy. Here, we show that the local
+magnetization of the ultra-thin Co film can be switched by just applying a gate
+electric field without an assist of any external magnetic field or current
+flow. The local magnetization switching is explained by the nucleation and
+annihilation of the magnetic domain through the domain wall motion induced by
+the electric field. Our results lead to external field free and ultra-low
+energy spintronic applications.",1603.08688v1
+2016-06-30,Quantized chiral magnetic current from reconnections of magnetic flux,"We introduce a new mechanism for the chiral magnetic effect that does not
+require an initial chirality imbalance. The chiral magnetic current is
+generated by reconnections of magnetic flux that change the magnetic helicity
+of the system. The resulting current is entirely determined by the change of
+magnetic helicity, and it is quantized.",1606.09611v2
+2016-07-08,Third Order Perturbed Energy of Cobalt Ferrite Thick Films,"Magnetic properties and easy axis orientation of cobalt ferrite films with
+applied magnetic field and number of layers were studied. According to our
+theoretical studies explained in this manuscript, the magnetically easy and
+hard directions of cobalt ferrite films solely depend on in plane and out of
+plane magnetic fields. According to 3-D and 2-D plots, there are many easy and
+hard directions at one particular value of in plane or out of plane magnetic
+field. The magnetic properties were investigated for cobalt ferrite films with
+thickness up to 10,000 unit cells. The total magnetic energy was calculated for
+a unit spin of cobalt.",1607.02323v1
+2016-10-20,Dual atomic interferometer with a tunable point of minimum magnetic sensitivity,"Atomic interferometers are often affected by magnetic field fluctuations.
+Using the clock transition at zero magnetic field minimizes the effect of these
+fluctuations. There is another transition in rubidium that minimizes the
+magnetic sensitivity at 3.2 G.We combine the previous two transitions to obtain
+minimum magnetic sensitivity at a tunable magnetic field between 2.2 and 3.2 G.
+The two interferometers evolve independently from each other and we control the
+magnetic sensitivity by changing the population in both transitions with a
+microwave pulse.",1610.06271v2
+2016-12-10,Origin of Strong Magnetic Fields of Magnetars,"Since there is 3P2 neutron superfluid in neutron star interior, it can be
+treated as a system of magnetic dipoles. Under the presence of background
+magnetic field, the magnetic dipoles tend to align in the same direction. When
+the temperature is lower than 10**7K, the strong magnetic fields of the
+magnetars may originate from the induced magnetic moment of the 3P2 neutron
+Cooper pairs in the anisotropic neutron superfluid. And this gives a convenient
+explanation of the strong magnetic field of magnetars.",1612.04656v1
+2017-01-01,Electrical Transport of perpendicularly magnetized L10-MnGa and MnAl films,"Ferromagnetic films of L10-ordered MnGa and MnAl that exhibit giant
+perpendicular magnetic anisotropy and great controllability in the magnetism
+and structural disorders show promise not only in the applications in magnetic
+recording, permanent magnets and spintronics, but also in controllable studies
+of disorder-relevant electrical transport phenomena. In this article, we review
+the intriguing experimental observations of the orbital two-channel Kondo
+effect and anomalous Hall effect in L10-ordered MnGa and MnAl thin films with
+perpendicular magnetic anisotropy. We also give a perspective with regards to
+the future technological and fundamental applications of these perpendicularly
+magnetized Mn-based binary alloy films.",1701.00191v1
+2017-01-30,On slowly rotating magnetized white dwarfs,"Rotating magnetized white dwarfs are studied within the framework of general
+relativity using Hartle's formalism. Matter inside magnetized white dwarfs is
+described by an equation of state of particles under the action of a constant
+magnetic field which introduces anisotropic pressures. Our study is done for
+values of magnetic field below $10^{13}$ G -a threshold of the maximum magnetic
+field obtained by the cylindrical metric solution- and typical densities of
+WDs. The effects of the rotation and magnetic field combined are discussed, we
+compute relevant magnitudes such as the moment of inertia, quadrupole moment
+and eccentricity.",1701.08792v1
+2017-04-23,Controlling the Kelvin Force: Basic Strategies and Applications to Magnetic Drug Targeting,"Motivated by problems arising in magnetic drug targeting, we propose to
+generate an almost constant Kelvin (magnetic) force in a target subdomain,
+moving along a prescribed trajectory. This is carried out by solving a
+minimization problem with a tracking type cost functional. The magnetic sources
+are assumed to be dipoles and the control variables are the magnetic field
+intensity, the source location and the magnetic field direction. The resulting
+magnetic field is shown to effectively steer the drug concentration, governed
+by a drift-diffusion PDE, from an initial to a desired location with limited
+spreading.",1704.06872v1
+2017-06-05,Generalized magnetic mirrors,"We propose generalized magnetic mirrors that can be achieved by excitations
+of sole electric resonances. Conventional approaches to obtain magnetic mirrors
+rely heavily on exciting the fundamental magnetic dipoles, whereas here we
+reveal that besides magnetic resonances, electric resonances of higher orders
+can be also employed to obtain highly efficient magnetic mirrors. Based on the
+electromagnetic duality, it is also shown that electric mirrors can be achieved
+by exciting magnetic resonances. We provide direct demonstrations of the
+generalized mirrors proposed in a simple system of one-dimensional periodic
+array of all-dielectric wires, which may shed new light to many advanced fields
+of photonics related to resonant multipolar excitations and interferences.",1706.01398v2
+2018-01-16,Neutron Anomalous Magnetic Moment in Dense Magnetized Systems,"In this work, we calculate the neutron anomalous magnetic moment supposing
+that this value can depend on the density and magnetic field of system. We
+employ the lowest order constraint variation (LOCV) method and $AV_{18}$
+nuclear potential to calculate the medium dependency of the neutron anomalous
+magnetic moment. It is confirmed that the neutron anomalous magnetic moment
+increases by increasing the density, while it decreases as the magnetic field
+grows. The energy and equation of state for the system have also been
+investigated.",1801.05277v1
+2018-01-30,Possible relation between pulsar rotation and evolution of magnetic inclination,"The pulsar timing is observed to be different from predicted by a simple
+magnetic dipole radiation. We choose eight pulsars whose braking index was
+reliably determined. Assuming the smaller values of braking index are dominated
+by the secular evolution of the magnetic inclination, we calculate the
+increasing rate of the magnetic inclination for each pulsar. We find a possible
+relation between the rotation frequency of each pulsar and the inferred
+evolution of the magnetic inclination. Due to the model-dependent fit of the
+magnetic inclination and other effects, more observational indicators for the
+change rate of magnetic inclination are needed to test the relation.",1801.09915v1
+2018-02-22,Phase transition of vortex states in two-dimensional superconductors under a oscillating magnetic field from the chiral helimagnet,"We have investigated vortex states in two-dimensional superconductors under a
+oscillating magnetic field from a chiral helimagnet. We have solved the
+two-dimensional Ginzburg-Landau equations with finite element method. We have
+found that when the magnetic field from the chiral helimagnet increases,
+vortices appear all at once in all periodic regions. This transition is
+different from that under the uniform magnetic field. Under the composite
+magnetic field with the oscillating and uniform fields (down-vortices),
+vortices antiparallel to the uniform magnetic field disappear. Then, the small
+uniform magnetic field easily remove down-vortices.",1802.07937v1
+2018-03-19,Dynamics of a Magnetic Needle Magnetometer: Sensitivity to Landau-Lifshitz-Gilbert Damping,"An analysis of a single-domain magnetic needle in the presence of an external
+magnetic field ${\bf B}$ is carried out with the aim of achieving a high
+precision magnetometer. We determine the uncertainty $\Delta B$ of such a
+device due to Gilbert dissipation and the associated internal magnetic field
+fluctuations that gives rise to diffusion of the magnetic needle axis direction
+${\bf n}$ and the needle orbital angular momentum. The levitation of the
+magnetic needle in a magnetic trap and its stability are also analyzed.",1803.10064v2
+2018-12-20,Self-Organized Criticality of Domain Walls and Magnetization Curve,"We propose a kind of Ginzburg--Landau equation with quenched randomness.
+There is a pinning--depinning transition in the system when the external
+magnetic force is changed. The transition is self-organized when the external
+magnetic field is slowly changed under the demagnetizing effect. The total
+magnetization increases stepwise and the probability distribution of the
+increase in the total magnetization approximately obeys a power law. A
+hysteresis loop is obtained when the external magnetic field is changed
+reciprocally. In our model, the coercivity in the magnetization curve is
+expressed as the critical value for the pinning-depinning transition.",1812.08344v1
+2019-04-22,Problematic nature of plasmoid theory of magnetic reconnection,"Plasmoid theory uses two-coordinate models to explain fast magnetic
+reconnection, which occurs on an Alfv\'enic, not a resistive time scale, in
+plasmas that are evolving in the near-ideal limit. The primary application has
+been to three-dimensional naturally-occurring plasmas. A magnetic field
+representation that applies to all magnetic fields allows features of magnetic
+evolution in toroidal and natural plasmas to be compared. This comparison
+illustrates why plasmoid models of magnetic field evolution are not robust
+solutions to Maxwell's equations. Despite five-hundred papers on plasmoid
+models, they provide a problematic description of fast magnetic reconnection.",1904.09836v2
+2019-07-02,Stellarators with permanent magnets,"It is shown that the magnetic-field coils of a stellarator can, at least in
+principle, be substantially simplified by the use of permanent magnets. Such
+magnets cannot create toroidal magnetic flux but they can be used to shape the
+plasma and thus to create poloidal flux and rotational transform, thereby
+easing the requirements on the magnetic-field coils. As an example, a
+quasiaxisymmetric stellarator configuration is constructed with only 8 circular
+coils (all identical) and permanent magnets.",1907.01363v2
+2019-07-30,Graphical Magnetogranulometry of EMG909,"The magnetization curve of the ferrofluid EMG909 is measured. It can
+adequately be described by a superposition of four Langevin terms. The
+effective dipole strength of the magnetic particles in this fluid is
+subsequently obtained by a graphical rectification of the magnetization curve
+based on the inverse Langevin function. The method yields the arithmetic and
+the harmonic mean of the magnetic moment distribution function, and a guess for
+the geometric mean and the relative standard deviation. It has the advantage
+that it does not require a prejudiced guess of the distribution function of the
+poly-disperse suspension of magnetic particles.",1907.12779v2
+2020-01-17,Generation of focusing ion beams by magnetized electron sheath acceleration,"We present the first 3D particle-in-cell simulations of laser driven
+sheath-based ion acceleration in a kilotesla-level applied magnetic field. The
+applied magnetic field creates two distinct stages in the acceleration process
+associated with the time-evolving magnetization of the hot electron sheath and
+results in a focusing, magnetic field-directed ion source of multiple species
+with strongly enhanced energy and number. The benefits of adding the magnetic
+field are downplayed in 2D simulations, which strongly suggests the feasibility
+of observing magnetic field effects under experimentally relevant conditions.",2001.06117v1
+2020-02-17,Periodic Magnetic Geodesics on Heisenberg Manifolds,"We study the dynamics of magnetic flows on Heisenberg groups. Let $H$ denote
+the three-dimensional simply connected Heisenberg Lie group endowed with a
+left-invariant Riemannian metric and an exact, left-invariant magnetic field.
+Let $\Gamma$ be a lattice subgroup of $H,$ so that $\Gamma\backslash H$ is a
+closed nilmanifold. We first find an explicit description of magnetic geodesics
+on $H$, then determine all closed magnetic geodesics and their lengths for
+$\Gamma \backslash H$. We then consider two applications of these results: the
+density of periodic magnetic geodesics and marked magnetic length spectrum
+rigidity.",2002.06982v1
+2020-12-23,Magnetic Moment Tensor Potentials for collinear spin-polarized materials reproduce different magnetic states of bcc Fe,"We present the magnetic Moment Tensor Potentials (mMTPs), a class of
+machine-learning interatomic potentials, accurately reproducing both
+vibrational and magnetic degrees of freedom as provided, e.g., from
+first-principles calculations. The accuracy is achieved by a two-step
+minimization scheme that coarse-grains the atomic and the spin space. The
+performance of the mMTPs is demonstrated for the prototype magnetic system bcc
+iron, with applications to phonon calculations for different magnetic states,
+and molecular dynamics simulations with fluctuating magnetic moments.",2012.12763v2
+2021-07-08,Warm Magnets,"Warm magnets are magnets that function in normal ambient temperature
+conditions. These types are mostly using a soft steel yoke for field
+amplification and either Copper or Aluminium coils or permanent magnets to
+generate the field. Magnets powered with such normal-conducting coils are often
+also called classical, iron dominated or resistive magnets. Since decades these
+types of magnets are the workhorse for most linear and circular accelerators
+and beam transfer lines.",2107.03965v1
+2022-01-25,Design and Description of the CMS Magnetic System Model,"This review describes the composition of the Compact Muon Solenoid (CMS)
+detector and the methodology for modelling the heterogeneous CMS magnetic
+system, starting with the formulation of the magnetostatics problem for
+modelling the magnetic flux of the CMS superconducting solenoid enclosed in a
+steel flux-return yoke. The review includes a section on the magnetization
+curves of various types of steel used in the CMS magnet yoke. The evolution of
+the magnetic system model over 20 years is presented in the discussion section
+and is well illustrated by the CMS model layouts and the magnetic flux
+distribution.",2201.10478v1
+2022-03-22,Nanoscale magnetism probed in a matter-wave interferometer,"We explore a wide range of fundamental magnetic phenomena by measuring the
+dephasing of matter-wave interference fringes upon application of a variable
+magnetic gradient. The versatility of our interferometric Stern-Gerlach
+technique enables us to study alkali atoms, organic radicals and fullerenes in
+the same device, with magnetic moments ranging from a Bohr magneton to less
+than a nuclear magneton. We find evidence for magnetization of a supersonic
+beam of organic radicals and, most notably, observe a strong magnetic response
+of a thermal C$_{60}$ beam consistent with high-temperature atom-like
+deflection of rotational magnetic moments.",2203.11866v1
+2022-04-15,Energy Extraction via Magnetic Reconnection in the Ergosphere of a rotating non-Kerr Black Hole,"Magnetic reconnection process in the ergosphere is investigated for a
+relativistic plasma around a rotating non-Kerr black hole. For a rotating
+non-Kerr black hole immersed in magnetic field generated by an externally
+material, anti-parallel magnetic field line could form in the ergosphere due to
+the frame dragging. Therefore, magnetic reconnection could occur in the
+ergosphere. Such magnetic reconnection may generate negative energy at infinity
+by redistributing the angular momentum during the process. The results show
+that, with the effect of the deformed parameter, extraction of energy from a
+rotating non-Kerr black hole by magnetic reconnection could be enhanced in the
+presence of a positive deformed parameter.",2204.07338v1
+2022-06-21,Magnetic Forces in Paramagnetic Fluids,"An overview of the effect of a magnetic field gradient on fluids with linear
+magnetic susceptibilities is given. It is shown that two commonly encountered
+expressions, the magnetic field gradient force and the concentration gradient
+force for paramagnetic species in solution are equivalent for incompressible
+fluids. The magnetic field gradient and concentration gradient forces are
+approximations of the Kelvin force and Korteweg-Helmholtz force densities,
+respectively. The criterion for the appearance of magnetically induced
+convection is derived. Experimental work in which magnetically induced
+convection plays a role is reviewed.",2206.10529v4
+2022-09-09,Quantum Stoner-Wohlfarth model of two-dimensional single domain magnets,"The Stoner-Wohlfarth (SW) model is a classical model for magnetic hysteresis
+of single-domain particles. For two-dimensional magnets at finite temperature,
+the SW model must be extended to include intrinsic strong spin fluctuations. We
+predict several fundamentally different hysteresis properties between 2D and 3D
+magnets. The magnetization switching diagram known as the Asteroid figure in
+the conventional SW model becomes highly temperature dependent and asymmetric
+with respect to the transverse and longitudinal magnetic fields. Our results
+provide new insights for 2D magnetic materials based spintronics applications.",2209.04479v1
+2022-10-16,On the angular anisotropy of the randomly-averaged magnetic neutron scattering cross section of nanoparticles,"We calculate the magnetic SANS cross section of dilute ensembles of uniformly
+magnetized and randomly-oriented Stoner-Wohlfarth particles using the
+Landau-Lifshitz equation. The focus of our study is on the angular anisotropy
+of the magnetic SANS signal as it can be seen on a two-dimensional
+position-sensitive detector. Depending on the symmetry of the magnetic
+anisotropy of the particles (e.g. uniaxial, cubic), an anisotropic magnetic
+SANS pattern may result, even in the demagnetized state or at the coercive
+field. The case of inhomogeneously magnetized particles and the effects of a
+particle-size distribution and interparticle correlations are discussed.",2210.08406v1
+2022-10-23,An experimental analysis from the magnetic interactions in nanowire arrays,"We study the magnetic interactions experimentally in nanostructures of
+nanowire arrays. The intensity value obtained from the interactions provides
+information about its magnetic behavior. We observed two types of experimental
+magnetic behavior, i. e., demagnetized and magnetized. Our approach represents
+the first experimental way to analyze the magnetic behavior of a nanostructure
+considering its magnetic dependence, which is very important for applications
+in sensors, for example.",2210.12783v1
+2022-12-29,Magnetically enhanced thin film coarsening by a magnetic XPFC model allowing to decouple magnetic anisotropy and magnetostriction,"External magnetic fields provide a macroscopic control mechanism to influence
+the microstructure of polycrystalline materials. We model the influence of
+strong magnetic fields on grain growth in thin films with a magnetic extended
+phase field crystal (XPFC) model. The magneto-structural effects are
+incorporated into the correlation function in reciprocal space. With this
+approach magnetic anisotropy, magnetostriction and mobility of grain boundary
+can be controlled and a variety of geometrical and topological properties
+consistent with experimental results can be determined.",2212.14416v1
+2023-02-26,Low-temperature thermal Hall conductivity of Pr2Zr2O7 single crystal,"To probe the peculiar excitations spinons and magnetic monopoles in the
+quantum spin ice candidate Pr2Zr2O7, we studied the low-temperature thermal
+Hall conductivity (\k{appa}xy) and thermal conductivity (\k{appa}xx) of
+Pr2Zr2O7 single crystal with magnetic fields applied along the [111] axis. The
+magnetic field dependencies of \k{appa}xx suggest the roles of magnetic
+excitations in thermal conductivity, that is, the emergent magnetic monopoles
+can transport heat at T > 1.4 K and spinons mainly scatter phonons at lower
+temperatures. The finite \k{appa}xy was observed at low fields of several Tesla
+and was discussed to be related to the magnetic excitations, including magnetic
+monopoles as well as spinons.",2302.13300v1
+2023-04-27,Effective Tight-Binding Model of Compensated Ferrimagnetic Weyl Semimetal with Spontaneous Orbital Magnetization,"The effective tight-binding model with compensated ferrimagnetic
+inverse-Heusler lattice Ti$_{2}$MnAl, candidate material of magnetic Weyl
+semimetal, is proposed. The energy spectrum near the Fermi level, the
+configurations of the Weyl points, and the anomalous Hall conductivity are
+calculated. We found that the orbital magnetization is finite, while the total
+spin magnetization vanishes, at the energy of the Weyl points. The magnetic
+moments at each site are correlated with the orbital magnetization, and can be
+controlled by the external magnetic field.",2304.14009v1
+2023-07-02,Unveiling Stable One-dimensional Magnetic Solitons in Magnetic Bilayers,"We propose a novel model which efficiently describes the magnetization
+dynamics in a magnetic bilayer system. By applying a particular gauge
+transformation to the Landau-Lifshitz-Gilbert (LLG) equation, we successfully
+convert the model into an exactly integrable framework. Thus the obtained
+analytical solutions allows us to predict a 1D magnetic soliton pair existed by
+tunning the thickness of the spacing layer between the two ferrimagnetic
+layers. The decoupling-unlocking-locking transition of soliton motion is
+determined at various interaction intensitiy. Our results have implications for
+the manipulation of magnetic solitons and the design of magnetic soliton-based
+logic devices.",2307.00471v1
+2023-07-04,Phonon-induced magnetization dynamics in Co-doped iron garnets,"The developing field of strain-induced magnetization dynamics offers a
+promising path toward efficiently controlling spins and phase transitions.
+Understanding the underlying mechanisms is crucial in finding the optimal
+parameters supporting the phononic switching of magnetization. Here, we present
+an experimental and numerical study of time-resolved magnetization dynamics
+driven by the resonant excitation of an optical phonon mode in iron garnets.
+Upon pumping the latter with an infrared pulse obtained from a free-electron
+laser, we observe spatially-varying magnetization precession, with its phase
+depending on the direction of an external magnetic field. Our micromagnetic
+simulations effectively describe the magnetization precession and switching in
+terms of laser-induced changes in the crystal's magneto-elastic energy.",2307.01907v1
+2024-02-29,Magnetic catalysis and diamagnetism from pion fluctuations,"In the framework of Nambu--Jona-Lasinio model beyond mean field
+approximation, the effects of pion fluctuations on (inverse) magnetic catalysis
+and magnetic susceptibility are studied. The negative magnetic susceptibility
+at low temperature is observed when contributions from both neutral and charged
+pions are taken into account. In weak field approximation, it is observed that
+at finite temperature, the magnetic inhibition effect in the chiral limit,
+resulting from the difference between the transverse and longitudinal
+velocities of neutral pions, converts to weak magnetic catalysis when
+considering a non-zero current quark mass. Moreover, the magnetic catalysis is
+amplified by the charged pions.",2402.19193v1
+2007-03-08,3D Relativistic Magnetohydrodynamic Simulations of Magnetized Spine-Sheath Relativistic Jets,"Numerical simulations of weakly magnetized and strongly magnetized
+relativistic jets embedded in a weakly magnetized and strongly magnetized
+stationary or weakly relativistic (v = c/2) sheath have been performed. A
+magnetic field parallel to the flow is used in these simulations performed by
+the new GRMHD numerical code RAISHIN used in its RMHD configuration. In the
+numerical simulations the Lorentz factor $\gamma = 2.5$ jet is precessed to
+break the initial equilibrium configuration. In the simulations sound speeds
+are $\lesssim c/\sqrt 3$ in the weakly magnetized simulations and $\lesssim
+0.3c$ in the strongly magnetized simulations. The Alfven wave speed is
+$\lesssim 0.07c$ in the weakly magnetized simulations and $\lesssim 0.56c$ in
+the strongly magnetized simulations. The results of the numerical simulations
+are compared to theoretical predictions from a normal mode analysis of the
+linearized relativistic magnetohydrodynamic (RMHD) equations capable of
+describing a uniform axially magnetized cylindrical relativistic jet embedded
+in a uniform axially magnetized relativistically moving sheath. The theoretical
+dispersion relation allows investigation of effects associated with maximum
+possible sound speeds, Alfven wave speeds near light speed and relativistic
+sheath speeds. The prediction of increased stability of the weakly magnetized
+system resulting from c/2 sheath speeds and the stabilization of the strongly
+magnetized system resulting from c/2 sheath speeds is verified by the numerical
+simulation results.",0703190v1
+1999-11-03,Flux pinning by regular arrays of ferromagnetic dots,"The pinning of flux lines by two different types of regular arrays of
+submicron magnetic dots is studied in superconducting Pb films; rectangular Co
+dots with in-plane magnetization are used as pinning centers to investigate the
+influence of the magnetic stray field of the dots on the pinning phenomena,
+whereas multilayered Co/Pt dots with out-of-plane magnetization are used to
+study the magnetic interaction between the flux lines and the magnetic moment
+of the dots. For both types of pinning arrays, matching anomalies are observed
+in the magnetization curves versus perpendicular applied field at integer and
+rational multiples of the first matching field, which correspond to stable flux
+configurations in the artificially created pinning potential. By varying the
+magnetic domain structure of the Co dots with in-plane magnetization, a clear
+influence of the stray field of the dots on the pinning efficiency is found.
+For the Co/Pt dots with out-of-plane magnetization, a pronounced field
+asymmetry is observed in the magnetization curves when the dots are magnetized
+in a perpendicular field prior to the measurement. This asymmetry can be
+attributed to the interaction of the out-of-plane magnetic moment of the Co/Pt
+dots with the local field of the flux lines and indicates that flux pinning is
+stronger when the magnetic moment of the dot and the field of the flux line
+have the same polarity.",9911033v1
+2006-12-13,A Model for Predicting Magnetic Targeting of Multifunctional Particles in the Microvasculature,"A mathematical model is presented for predicting magnetic targeting of
+multifunctional carrier particles that are designed to deliver therapeutic
+agents to malignant tissue in vivo. These particles consist of a nonmagnetic
+core material that contains embedded magnetic nanoparticles and therapeutic
+agents such as photodynamic sensitizers. For in vivo therapy, the particles are
+injected into the vascular system upstream from malignant tissue, and captured
+at the tumor using an applied magnetic field. The applied field couples to the
+magnetic nanoparticles inside the carrier particle and produces a force that
+attracts the particle to the tumor. In noninvasive therapy the applied field is
+produced by a permanent magnet positioned outside the body. In this paper a
+mathematical model is developed for predicting noninvasive magnetic targeting
+of therapeutic carrier particles in the microvasculature. The model takes into
+account the dominant magnetic and fluidic forces on the particles and leads to
+an analytical expression for predicting their trajectory. An analytical
+expression is also derived for predicting the volume fraction of embedded
+magnetic nanoparticles required to ensure capture of the carrier particle at
+the tumor. The model enables rapid parametric analysis of magnetic targeting as
+a function of key variables including the size of the carrier particle, the
+properties and volume fraction of the embedded magnetic nanoparticles, the
+properties of the magnet, the microvessel, the hematocrit of the blood and its
+flow rate.",0612116v1
+2007-06-27,Magnetic Energy and Helicity Budgets in the Active-Region Solar Corona. I. Linear Force-Free Approximation,"We self-consistently derive the magnetic energy and relative magnetic
+helicity budgets of a three-dimensional linear force-free magnetic structure
+rooted in a lower boundary plane. For the potential magnetic energy we derive a
+general expression that gives results practically equivalent to those of the
+magnetic Virial theorem. All magnetic energy and helicity budgets are
+formulated in terms of surface integrals applied to the lower boundary, thus
+avoiding computationally intensive three-dimensional magnetic field
+extrapolations. We analytically and numerically connect our derivations with
+classical expressions for the magnetic energy and helicity, thus presenting a
+so-far lacking unified treatment of the energy/helicity budgets in the
+constant-alpha approximation. Applying our derivations to photospheric vector
+magnetograms of an eruptive and a noneruptive solar active regions, we find
+that the most profound quantitative difference between these regions lies in
+the estimated free magnetic energy and relative magnetic helicity budgets. If
+this result is verified with a large number of active regions, it will advance
+our understanding of solar eruptive phenomena. We also find that the
+constant-alpha approximation gives rise to large uncertainties in the
+calculation of the free magnetic energy and the relative magnetic helicity.
+Therefore, care must be exercised when this approximation is applied to
+photospheric magnetic field observations. Despite its shortcomings, the
+constant-alpha approximation is adopted here because this study will form the
+basis of a comprehensive nonlinear force-free description of the energetics and
+helicity in the active-region solar corona, which is our ultimate objective.",0706.4122v1
+2008-08-06,Cluster Magnetic Fields from Galactic Outflows,"We performed cosmological, magneto-hydrodynamical simulations to follow the
+evolution of magnetic fields in galaxy clusters, exploring the possibility that
+the origin of the magnetic seed fields are galactic outflows during the
+star-burst phase of galactic evolution. To do this we coupled a semi-analytical
+model for magnetized galactic winds as suggested by \citet{2006MNRAS.370..319B}
+to our cosmological simulation. We find that the strength and structure of
+magnetic fields observed in galaxy clusters are well reproduced for a wide
+range of model parameters for the magnetized, galactic winds and do only weakly
+depend on the exact magnetic structure within the assumed galactic outflows.
+Although the evolution of a primordial magnetic seed field shows no significant
+differences to that of galaxy clusters fields from previous studies, we find
+that the magnetic field pollution in the diffuse medium within filaments is
+below the level predicted by scenarios with pure primordial magnetic seed
+field. We therefore conclude that magnetized galactic outflows and their
+subsequent evolution within the intra-cluster medium can fully account for the
+observed magnetic fields in galaxy clusters. Our findings also suggest that
+measuring cosmological magnetic fields in low-density environments such as
+filaments is much more useful than observing cluster magnetic fields to infer
+their possible origin.",0808.0919v2
+2008-08-27,Magnetic phase evolution in the spinel compounds Zn$_{1-x}$Co$_x$Cr$_2$O$_4$,"We present the magnetic properties of complete solid solutions of
+ZnCr$_2$O$_4$ and CoCr$_2$O$_4$: two well-studied oxide spinels with very
+different magnetic ground states. ZnCr$_2$O$_4$, with non-magnetic $d^{10}$
+cations occupying the A site and magnetic $d^3$ cations on the B site, is a
+highly frustrated antiferromagnet. CoCr$_2$O$_4$, with magnetic $d^7$ cations
+(three unpaired electrons) on the A site as well, exhibits both N\'eel
+ferrimagnetism as well as commensurate and incommensurate non-collinear
+magnetic order. More recently, CoCr$_2$O$_4$ has been studied extensively for
+its polar behavior which arises from conical magnetic ordering. Gradually
+introducing magnetism on the A site of ZnCr$_2$O$_4$ results in a transition
+from frustrated antiferromagnetism to glassy magnetism at low concentrations of
+Co, and eventually to ferrimagnetic and conical ground states at higher
+concentrations. Real-space Monte-Carlo simulations of the magnetic
+susceptibility suggest that the first magnetic ordering transition and features
+of the susceptibility across $x$ are captured by near-neighbor self- and
+cross-couplings between the magnetic A and B atoms. We present as a part of
+this study, a method for displaying the temperature dependence of magnetic
+susceptibility in a manner which helps distinguish between compounds possessing
+purely antiferromagnetic interactions from compounds where other kinds of
+ordering are present.",0808.3789v3
+2010-07-28,A Theory about Electric Current and Heating in Plasma,"The traditional generalized Ohm's law in MHD do not explicitly present the
+relation of electric currents and electric fields in fully ionized plasma, and
+lead to some unexpected concepts, such as ""the magnetic frozen-in plasma"",
+magnetic reconnection etc. In the present paper, we solve the balance equation
+can give exact solution of the velocities of electrons and ions, and then
+derived the electric current in fully ionized plasma. In the case ignoring
+boundary condition, there is no electric current in the plane perpendicular to
+the magnetic field when external forces are ignored. The electric field in the
+plane perpendicular to magnetic field do not contribute to the electric
+currents, so do the induced electric field from the motion of the plasma across
+magnetic field. The lack of induced electric current will keep magnetic field
+in space unaffected. The velocity of the bulk velocity of the plasma
+perpendicular to magnetic field is not free, it is decided by electromagnetic
+field and the external forces. We conclude that the bulk velocity of the fully
+ionized plasma is not coupled with the magnetic field. The motion of the plasma
+do not change the magnetic field in space, but the plasma will be confined by
+magnetic field.
+  Due to the confinement of magnetic field, the plasma kinetic energy will be
+transformed into plasma thermal energy by the Lamor motion and collisions
+between the same species of particles inside plasma. Because the electric field
+perpendicular to magnetic field do not contribute electric current, the
+variation of magnetic field will transfer energy directly into the plasma
+thermal energy by induced electric field. The heating of plasma could be from
+the kinetic energy and the variation of magnetic field.",1007.4959v1
+2011-03-05,Physics and measurements of magnetic materials,"Magnetic materials, both hard and soft, are used extensively in several
+components of particle accelerators. Magnetically soft iron-nickel alloys are
+used as shields for the vacuum chambers of accelerator injection and extraction
+septa; Fe-based material is widely employed for cores of accelerator and
+experiment magnets; soft spinel ferrites are used in collimators to damp
+trapped modes; innovative materials such as amorphous or nanocrystalline core
+materials are envisaged in transformers for high-frequency polyphase resonant
+convertors for application to the International Linear Collider (ILC). In the
+field of fusion, for induction cores of the linac of heavy-ion inertial fusion
+energy accelerators, based on induction accelerators requiring some 107 kg of
+magnetic materials, nanocrystalline materials would show the best performance
+in terms of core losses for magnetization rates as high as 105 T/s to 107 T/s.
+After a review of the magnetic properties of materials and the different types
+of magnetic behaviour, this paper deals with metallurgical aspects of
+magnetism. The influence of the metallurgy and metalworking processes of
+materials on their microstructure and magnetic properties is studied for
+different categories of soft magnetic materials relevant for accelerator
+technology. Their metallurgy is extensively treated. Innovative materials such
+as iron powder core materials, amorphous and nanocrystalline materials are also
+studied. A section considers the measurement, both destructive and
+non-destructive, of magnetic properties. Finally, a section discusses magnetic
+lag effects.",1103.1069v1
+2011-11-30,Self-Similar Solutions for Viscous and Resistive ADAF,"In this paper, the self-similar solution of resistive advection dominated
+accretion flows (ADAF) in the presence of a pure azimuthal magnetic field is
+investigated. The mechanism of energy dissipation is assumed to be the
+viscosity and the magnetic diffusivity due to turbulence in the accretion flow.
+It is assumed that the magnetic diffusivity and the kinematic viscosity are not
+constant and vary by position and $\alpha$-prescription is used for them. In
+order to solve the integrated equations that govern the behavior of the
+accretion flow, a self-similar method is used. The solutions show that the
+structure of accretion flow depends on the magnetic field and the magnetic
+diffusivity. As, the radial infall velocity and the temperature of the flow
+increase, and the rotational velocity decreases. Also, the rotational velocity
+for all selected values of magnetic diffusivity and magnetic field is
+sub-Keplerian. The solutions show that there is a certain amount of magnetic
+field that the rotational velocity of the flow becomes zero. This amount of the
+magnetic field depends on the gas properties of the disc, such as adiabatic
+index and viscosity, magnetic diffusivity, and advection parameters. The
+solutions show the mass accretion rate increases by adding the magnetic
+diffusivity and in high magnetic pressure case, the ratio of the mass accretion
+rate to the Bondi accretion rate decreases as magnetic field increases. Also,
+the study of Lundquist and magnetic Reynolds numbers based on resistivity
+indicates that the linear growth of magnetorotational instability (MRI) of the
+flow decreases by resistivity. This property is qualitatively consistent with
+resistive magnetohydrodynamics (MHD) simulations.",1111.7302v1
+2012-03-01,Magnetic properties of carbon nanodisk and nanocone powders,"We have investigated the magnetic properties of carbon powders which consist
+of nanodisks, nanocones, and a small fraction of carbon-black particles.
+Magnetization measurements were carried out using a superconducting quantum
+interference device in magnetic fields $-5<\mu_{0}H<5\:\mathrm{T}$ for
+temperatures in the range $2\leq T<350\:\mathrm{K}$. Measurements of the
+magnetization $M$ versus temperature $T$ and magnetic field $\mu_{0}H$ for
+these carbon samples show diamagnetism and paramagetism with an additional
+ferromagnetic contribution. The ferromagnetic magnetization is in agreement
+with the calculated magnetization from Fe impurities as determined by the
+particle-induced x-ray emission method ($<75\:\mu\mathrm{g/g}$). Magnetization
+measurements in weak magnetic fields show thermal hysteresis, and for strong
+fields the magnetization $M$ decreases as $M\sim aT^{-\alpha}$ with $\alpha<1$,
+which is slower than the Curie law ($\alpha=1$), when the temperature
+increases. The magnetization $M$ versus magnetic field $\mu_{0}H$ shows
+paramagnetic free-spin $S=\frac{1}{2}$ and $\frac{3}{2}$ behaviors for
+temperatures $T=2\:\mathrm{K}$ and $15\leq T\leq50\:\mathrm{K}$, respectively.
+A tendency for localization of electrons was found by electron spin resonance
+when the temperature $T$ decreases ($2<T<40\:\mathrm{K}$). The magnetic
+properties in these carbon cone and disk powder samples are more complex than a
+free-spin model predicts, which is apparently valid only for the temperature
+$T=2\:\mathrm{K}$.",1203.0284v3
+2013-01-21,Increase of magnetic hyperthermia efficiency due to dipolar interactions in low anisotropy magnetic nanoparticles : theoretical and experimental results,"When magnetic nanoparticles (MNPs) are single-domain and magnetically
+independent, their magnetic properties and the conditions to optimize their
+efficiency in magnetic hyperthermia applications are now well-understood.
+However, the influence of magnetic interactions on magnetic hyperthermia
+properties is still unclear. Here, we report hyperthermia and high-frequency
+hysteresis loop measurements on a model system consisting of MNPs with the same
+size but a varying anisotropy, which is an interesting way to tune the relative
+strength of magnetic interactions. A clear correlation between the MNP
+anisotropy and the squareness of their hysteresis loop in colloidal solution is
+observed : the larger the anisotropy, the smaller the squareness. Since low
+anisotropy MNPs display a squareness higher than the one of magnetically
+independent nanoparticles, magnetic interactions enhance their heating power in
+this case. Hysteresis loop calculations of independent and coupled MNPs are
+compared to experimental results. It is shown that the observed features are a
+natural consequence of the formation of chains and columns of MNPs during
+hyperthermia experiments: in these structures, when the MNP magnetocristalline
+anisotropy is small enough to be dominated by magnetic interactions, the
+hysteresis loop shape tends to be rectangular, which enhance their efficiency.
+On the contrary, when MNPs do not form chains and columns, magnetic
+interactions reduces the hysteresis loop squareness and the efficiency of MNPs
+compared to independent ones. The present work should improve the understanding
+and interpretation of magnetic hyperthermia experiments.",1301.5590v1
+2013-01-25,Does Magnetic Field-Rotation Misalignment Solve the Magnetic Braking Catastrophe in Protostellar Disk Formation?,"Stars form in dense cores of molecular clouds that are observed to be
+significantly magnetized. In the simplest case of a laminar (non-turbulent)
+core with the magnetic field aligned with the rotation axis, both analytic
+considerations and numerical simulations have shown that the formation of a
+large, $10^2\au$-scale, rotationally supported protostellar disk is suppressed
+by magnetic braking in the ideal MHD limit for a realistic level of core
+magnetization. This theoretical difficulty in forming protostellar disks is
+termed ""magnetic braking catastrophe"". A possible resolution to this problem,
+proposed by \citeauthor{HennebelleCiardi2009} and \citeauthor{Joos+2012}, is
+that misalignment between the magnetic field and rotation axis may weaken the
+magnetic braking enough to enable disk formation. We evaluate this possibility
+quantitatively through numerical simulations. We confirm the basic result of
+\citeauthor{Joos+2012} that the misalignment is indeed conducive to disk
+formation. In relatively weakly magnetized cores with dimensionless
+mass-to-flux ratio $\gtrsim 5$, it enabled the formation of rotationally
+supported disks that would otherwise be suppressed if the magnetic field and
+rotation axis are aligned. For more strongly magnetized cores, disk formation
+remains suppressed, however, even for the maximum tilt angle of $90\degree$. If
+dense cores are as strongly magnetized as indicated by OH Zeeman observations
+(with a mean dimensionless mass-to-flux ratio $\sim 2$), it would be difficult
+for the misalignment alone to enable disk formation in the majority of them. We
+conclude that, while beneficial to disk formation, especially for the
+relatively weak field case, the misalignment does not completely solve the
+problem of catastrophic magnetic braking in general.",1301.6545v1
+2013-03-06,Fast Diffusion of Magnetic Field in Turbulence and Origin of Cosmic Magnetism,"Turbulence is believed to play important roles in the origin of cosmic
+magnetism. While it is well known that turbulence can efficiently amplify a
+uniform or spatially homogeneous seed magnetic field, it is not clear whether
+or not we can draw a similar conclusion for a localized seed magnetic field.
+The main uncertainty is the rate of magnetic field diffusion on scales larger
+than the outer scale of turbulence. To measure the diffusion rate of magnetic
+field on those large scales, we perform a numerical simulation in which the
+outer scale of turbulence is much smaller than the size of the system. We
+numerically compare diffusion of a localized seed magnetic field and a
+localized passive scalar. We find that diffusion of the magnetic field can be
+much faster than that of the passive scalar and that turbulence can efficiently
+amplify the localized seed magnetic field. Based on the simulation result, we
+construct a model for fast diffusion of magnetic field. Our model suggests that
+a localized seed magnetic field can fill the whole system in (L_sys/L) times
+the large-eddy turnover time and that growth of the magnetic field stops in
+max(15, L_sys/L) times the large-eddy turnover time, where L_sys is the size of
+the system and $L$ is the driving scale. Our finding implies that, regardless
+of the shape of the seed field, fast magnetization is possible in turbulent
+systems, such as large-scale structure of the universe or galaxies.",1303.1227v1
+2013-04-11,Field induced phase transitions and phase diagrams in BiFeO_3-like multiferroics,"The incommensurate magnetic structures and phase diagrams of multiferroics
+has been explored on the basis of accurate micromagnetic analysis taking into
+account the spin flexoelecric interaction (Lifshitz invariant). The objects of
+the study are BiFeO_3-like single crystals and epitaxial films grown on the
+<111> substrates. The main control parameters are the magnetic field, the
+magnetic anisotropy, and the epitaxial strain in the case of films. We predict
+novel quasi-cycloidal structures induced by external magnetic field or by
+epitaxial strain in the BiFeO_3-films. Phase diagrams representing the regions
+of homogeneous magnetic states and incommensurate structures stability are
+constructed for the two essential geometries of magnetic field (magnetic field
+oriented parallel to the principal crystal axis C_3 and perpendicular to this
+direction C_3). It is shown that the direction of applied magnetic field
+substantially affects a set of magnetic phases, properties of incommensurate
+structures, character of phase transitions. Novel conical type of cycloidal
+ordering is revealed during the transition from incommensurate cycloidal
+structure into homogeneous magnetic state. Elaborated phase diagrams allow
+estimate appropriate combination of control parameters (magnetic field,
+magnetic anisotropy, exchange stiffness) required to the destruction of
+cycloidal ordering corresponding to the transition into homogeneous structure.
+The results show that the magnitude of critical magnetic field suppressing
+cycloid is lowered in multiferroics films comparing to single crystals, it can
+be also lowered by the selection of orientation of magnetic field. Our results
+can be useful for strain engineering of new multiferroic functional materials
+on demand.",1304.3204v1
+2014-10-07,Origin of Magnetic Field in the Intracluster Medium: Primordial or Astrophysical?,"The origin of magnetic fields in clusters of galaxies is still an unsolved
+problem, which is largely due to our poor understanding of initial seed
+magnetic fields. If the seed magnetic fields have primordial origins, it is
+likely that large-scale pervasive magnetic fields were present before the
+formation of the large-scale structure. On the other hand, if they were ejected
+from astrophysical bodies, they were highly localized in space at the time of
+injection. In this paper, using turbulence dynamo models for high magnetic
+Prandtl number fluids, we find constraints on the seed magnetic fields. The
+hydrodynamic Reynolds number based on the Spitzer viscosity in the intracluster
+medium (ICM) is believed to be less than $O(10^2)$, while the magnetic Reynolds
+number can be much larger than that. In this case, if the seed magnetic fields
+have primordial origins, they should be stronger than $O(10^{-11})$G, which is
+very close to the upper limit of $O(10^{-9})$G set by the cosmic microwave
+background (CMB) observations. On the other hand, if the seed magnetic fields
+were ejected from astrophysical bodies, any seed magnetic fields stronger than
+$O(10^{-9})$G can safely magnetize the intracluster medium. Therefore, it is
+less likely that primordial magnetic fields are the direct origin of
+present-day magnetic fields in the ICM.",1410.1893v1
+2015-03-12,Successive magnetic phase transitions in $\bmα$-RuCl$_3$: XY-like frustrated magnet on the honeycomb lattice,"The layered compound $\alpha$-RuCl$_3$ is composed of a honeycomb lattice of
+magnetic Ru$^{3+}$ ions with the $4d^5$ electronic state. We have investigated
+the magnetic properties of $\alpha$-RuCl$_3$ via magnetization and specific
+heat measurements using single crystals. It was observed that $\alpha$-RuCl$_3$
+undergoes a structural phase transition at $T_{t}\,{\simeq}\,150$ K accompanied
+by fairly large hysteresis. This structural phase transition is expected to be
+similar to that observed in closely related CrCl$_3$. The magnetizations and
+magnetic susceptibilities are strongly anisotropic, which mainly arise from the
+anisotropic $g$-factors, i.e., $g_{ab}\,{\simeq}\,2.5$ and $g_c\,{\simeq}\,0.4$
+for magnetic fields parallel and perpendicular to the $ab$ plane, respectively.
+These $g$-factors and the obtained entropy indicate that the effective spin of
+Ru$^{3+}$ is one-half, which results from the low-spin state. Specific heat
+data show that magnetic ordering occurs in four steps at zero magnetic field.
+The successive magnetic phase transitions should be ascribed to the competition
+among exchange interactions. The magnetic phase diagram for
+$H\,{\parallel}\,ab$ is obtained. We discuss the strongly anisotropic
+$g$-factors in $\alpha$-RuCl$_3$ and deduce that the exchange interaction is
+strongly XY-like. $\alpha$-RuCl$_3$ is magnetically described as a
+three-dimensionally coupled XY-like frustrated magnet on a honeycomb lattice.",1503.03591v1
+2015-07-01,Coronal heating in multiple magnetic threads,"Context. Heating the solar corona to several million degrees requires the
+conversion of magnetic energy into thermal energy. In this paper, we
+investigate whether an unstable magnetic thread within a coronal loop can
+destabilise a neighbouring magnetic thread. Aims. By running a series of
+simulations, we aim to understand under what conditions the destabilisation of
+a single magnetic thread can also trigger a release of energy in a nearby
+thread. Methods. The 3D magnetohydrodynamics code, Lare3d, is used to simulate
+the temporal evolution of coronal magnetic fields during a kink instability and
+the subsequent relaxation process. We assume that a coronal magnetic loop
+consists of non-potential magnetic threads that are initially in an equilibrium
+state. Results. The non-linear kink instability in one magnetic thread forms a
+helical current sheet and initiates magnetic reconnection. The current sheet
+fragments, and magnetic energy is released throughout that thread. We find
+that, under certain conditions, this event can destabilise a nearby thread,
+which is a necessary requirement for starting an avalanche of energy release in
+magnetic threads. Conclusions. It is possible to initiate an energy release in
+a nearby, non-potential magnetic thread, because the energy released from one
+unstable magnetic thread can trigger energy release in nearby threads, provided
+that the nearby structures are close to marginal stability.",1507.00259v1
+2017-02-20,How Anomalous Resistivity Accelerates Magnetic Reconnection,"Whether turbulence induced anomalous resistivity (AR) can facilitate a fast
+magnetic reconnection in collisionless plasma is a subject of active debate for
+decades. Recent space observations suggest that the reconnection rate can be
+higher than the Hall-reconnection rate and turbulent dissipation is required.
+In this paper, using particle-in-cell simulations, we present a case study of
+how AR produced by Buneman instability accelerates magnetic reconnection. We
+first show that the AR/drag produced by Buneman instability in a thin electron
+current layer 1) can dissipate magnetic energy stored in the current layer
+through dissipation of the kinetic energy of electron beams; 2) The
+inhomogeneous drag caused by wave couplings spontaneously breaks the magnetic
+field lines and causes impulsive fast non-Hall magnetic reconnection on
+electron-scales with a mean rate reaching 0.6 $V_A$. We then show that a
+Buneman instability driven by intense electron beams around the x-point in a 3D
+magnetic reconnection significantly enhances the dissipation of the magnetic
+energy. Electron-scale magnetic reconnections driven by the inhomogeneous drag
+around the x-line enhances the reconnection electric field and the in-plane
+perpendicular magnetic field. About 40\% of the released magnetic energy is
+converted into the electron thermal energy by AR while 50\% is converted into
+the kinetic energy of the electron beams through the acceleration by the
+reconnection electric field. The enhanced magnetic energy dissipation is
+balanced by a net Poynting flux in-flow. About 10\% of the released magnetic
+energy is brought out by an enhanced Poynting flux out-flow. These results
+suggest that AR with sufficient intensity and electron-scale inhomogeneity can
+significantly accelerate magnetic reconnection.",1702.06109v2
+2017-06-19,Origin and Structures of Solar Eruptions II: Magnetic Modeling (Invited Review),"The topology and dynamics of the three-dimensional magnetic field in the
+solar atmosphere govern various solar eruptive phenomena and activities, such
+as flares, coronal mass ejections, and filaments/prominences. We have to
+observe and model the vector magnetic field to understand the structures and
+physical mechanisms of these solar activities. Vector magnetic fields on the
+photosphere are routinely observed via the polarized light, and inferred with
+the inversion of Stokes profiles. To analyze these vector magnetic fields, we
+need first to remove the 180$^\circ$ ambiguity of the transverse components and
+correct the projection effect. Then, the vector magnetic field can be served as
+the boundary conditions for a force-free field modeling after a proper
+preprocessing. The photospheric velocity field can also be derived from a time
+sequence of vector magnetic fields. Three-dimensional magnetic field could be
+derived and studied with theoretical force-free field models, numerical
+nonlinear force-free field models, magnetohydrostatic models, and
+magnetohydrodynamic models. Magnetic energy can be computed with
+three-dimensional magnetic field models or a time series of vector magnetic
+field. The magnetic topology is analyzed by pinpointing the positions of
+magnetic null points, bald patches, and quasi-separatrix layers. As a well
+conserved physical quantity, magnetic helicity can be computed with various
+methods, such as the finite volume method, discrete flux tube method, and
+helicity flux integration method. This quantity serves as a promising parameter
+characterizing the activity level of solar active regions.",1706.05769v1
+2017-07-20,Micrometer-scale Magnetic Imaging of Geological Samples Using a Quantum Diamond Microscope,"Remanent magnetization in geological samples may record the past intensity
+and direction of planetary magnetic fields. Traditionally, this magnetization
+is analyzed through measurements of the net magnetic moment of bulk millimeter
+to centimeter sized samples. However, geological samples are often
+mineralogically and texturally heterogeneous at submillimeter scales, with only
+a fraction of the ferromagnetic grains carrying the remanent magnetization of
+interest. Therefore, characterizing this magnetization in such cases requires a
+technique capable of imaging magnetic fields at fine spatial scales and with
+high sensitivity. To address this challenge, we developed a new instrument,
+based on nitrogen-vacancy centers in diamond, which enables direct imaging of
+magnetic fields due to both remanent and induced magnetization, as well as
+optical imaging, of room-temperature geological samples with spatial resolution
+approaching the optical diffraction limit. We describe the operating principles
+of this device, which we call the quantum diamond microscope (QDM), and report
+its optimized image-area-normalized magnetic field sensitivity (20
+uT.um/Hz^1/2), spatial resolution (5 um), and field of view (4 mm), as well as
+trade-offs between these parameters. We also perform an absolute magnetic field
+calibration for the device in different modes of operation, including
+three-axis (vector) and single-axis (projective) magnetic field imaging.
+Finally, we use the QDM to obtain magnetic images of several terrestrial and
+meteoritic rock samples, demonstrating its ability to resolve spatially
+distinct populations of ferromagnetic carriers.",1707.06714v1
+2017-12-20,Optical Manipulation of Magnetic Vortex Visualized in situ by 4D Electron Microscopy,"Understanding the fundamental dynamics of topological vortex and antivortex
+naturally formed in micro/nanoscale ferromagnetic building blocks under
+external perturbations is crucial to magnetic vortex based information
+processing and spintronic devices. All previous studies have focused on
+magnetic vortex-core switching via external magnetic fields, spin-polarized
+currents, or spin waves, which have largely prohibited the investigation of
+novel spin configurations that could emerge from the ground states in
+ferromagnetic disks and their underlying dynamics. Here, we report in situ
+visualization of femtosecond laser quenching induced magnetic vortex change in
+various symmetric ferromagnetic Permalloy disks by Lorentz phase imaging using
+4D electron microscopy. Besides the switching of magnetic vortex chirality and
+polarity, we observed with distinct occurrence frequencies a plenitude of
+complex magnetic structures that have never been observed by magnetic field or
+current assisted switching. These complex magnetic structures consist of a
+number of newly created topological magnetic defects (vortex and antivortex)
+strictly conserving the topological winding number, demonstrating the direct
+impact of topological invariant on the magnetization dynamics in ferromagnetic
+disks. Their spin configurations show mirror or rotation symmetry due to the
+geometrical confinement of the disks. Combined micromagnetic simulations with
+the experimental observations reveal the underlying magnetization dynamics and
+formation mechanism of the optical quenching induced complex magnetic
+structures. Their distinct occurrence rates are pertinent to their
+formation-growth energetics and pinning effects at the disk edge. Based on
+these findings, we propose a paradigm of optical-quenching-assisted fast
+switching of vortex cores for the control of magnetic vortex based information
+recording and spintronic devices.",1712.07280v1
+2018-02-05,Magnetized advective accretion flows: formation of magnetic barriers in Magnetically Arrested Discs,"We discuss the importance of large scale strong magnetic field in the removal
+of angular momentum outward, as well as the possible origin of different kinds
+of magnetic barrier in advective, geometrically thick, sub-Keplerian accretion
+flows around black holes. The origin of this large scale strong magnetic field
+near the event horizon is due to the advection of the magnetic flux by the
+accreting gas from the environment, say, the interstellar medium or a companion
+star, because of flux freezing. In this simplest vertically averaged,
+1.5-dimensional disc model, we choose the maximum upper limit of the magnetic
+field, which the disc around a black hole can sustain. In this so called
+magnetically arrested disc (MAD) model, the accreting gas either decelerates or
+faces the magnetic barrier near the event horizon by the accumulated magnetic
+field depending on the geometry. The magnetic barrier may knock the matter to
+infinity. We suggest that these types of flow are the building block to produce
+jets and outflows in the accreting system. We also find that in some cases,
+when matter is trying to go back to infinity after knocking the barrier, matter
+is prevented being escaped by the cumulative action of strong gravity and the
+magnetic tension, hence by another barrier. In this way, magnetic field can
+lock the matter in between these two barriers and it might be a possible
+explanation for the formation of episodic jet.",1802.01594v1
+2018-05-03,Influence of magnetic disorders on Quantum Anomalous Hall Effect in Magnetic Topological Insulator Films beyond the two-dimensional limit,"Quantum anomalous Hall effect (QAHE) has been experimentally realized in
+magnetic topological insulator (MTI) thin films fabricated on magnetically
+doped (Bi,Sb)2Te3. In a MTI thin film with the magnetic easy axis along the
+normal direction (z-direction), orientations of magnetic dopants are randomly
+distributed around the magnetic easy axis, acting as magnetic disorders. With
+the aid of the non-equilibrium Green's function and Landauer-Buttiker
+formalism, we numerically study the influence of magnetic disorders on QAHE in
+a MTI thin film modeled by a three-dimensional tight-binding Hamiltonian. It is
+found that, due to the existence of gapless side surface states, QAHE is
+protected even in the presence of magnetic disorders as long as the z-component
+of magnetic moment of all magnetic dopants are positive. More importantly, such
+magnetic disorders also suppress the dissipation of the chiral edge states and
+enhance the quality of QAHE in MTI films. In addition, the effect of magnetic
+disorders depends very much on the film thickness, and the optimal influence is
+achieved at certain thickness. These findings are new features for QAHE in
+three-dimensional systems, not present in two-dimensional systems.",1805.01126v1
+2018-05-16,The origin and early evolution of a bipolar magnetic region in the solar photosphere,"Finding the formation mechanisms for bipolar configurations of strong local
+magnetic field under control of the relatively weak global magnetic field of
+the Sun is a key problem of the physics of solar activity. This study is aimed
+at discriminating whether the magnetic field or fluid motion plays a primary,
+active role in this process. The very origin and early development stage of
+Active Region 12548 are investigated based on SDO/HMI observations of 2016 May
+20--25. Full-vector magnetic and velocity fields are analyzed in parallel. The
+leading and trailing magnetic polarities are found to grow asymmetrically in
+terms of their amplitude, magnetic flux, and the time variation of these
+quantities. The leading-polarity magnetic element originates as a compact
+feature against the background of a distributed trailing-polarity field, with
+an already existing trailing-polarity magnetic element. No signs of strong
+horizontal magnetic fields are detected between the two magnetic poles. No
+predominant upflow between their future locations precedes the origin of this
+bipolar magnetic region (BMR); instead, upflows and downflows are mixed, with
+some prevalence of downflows. Any signs of a large-scale horizontal divergent
+flow from the area where the BMR develops are missing; in contrast, a normal
+supergranulation and mesogranulation pattern is preserved. This scenario of
+early BMR evolution is in strong contradiction with the expectations based on
+the model of a rising $\Omega$-shaped loop of a flux tube of strong magnetic
+field, and an \emph{in situ} mechanism of magnetic-field amplification and
+structuring should operate in this case.",1805.06486v2
+2018-08-22,Analytic solution of a magnetized tori with magnetic polarization around Kerr black holes,"We present the first family of magnetically polarized equilibrium tori around
+a Kerr black hole. The models were obtained in the test fluid approximation by
+assuming that the tori is a linear media, making it is possible to characterize
+the magnetic polarization of the fluid through the magnetic susceptibility
+$\chi_{m}$. The magnetohydrodynamic (MHD) structure of the models was solved by
+following the Komissarov approach, but with the aim of including the magnetic
+polarization of the fluid, the integrability condition for the magnetic
+counterpart was modified. We build two kinds of magnetized tori depending on
+whether the magnetic susceptibility is constant in space or not. In the models
+with constant $\chi_{m}$, we find that the paramagnetic tori ($\chi_{m}>0$) are
+more dense and less magnetized than the diamagnetic ones ($\chi_{m}<0$) in the
+region between the inner edge, $r_{in}$, and the center of the disk, $r_{c}$;
+however, we find the opposite behavior for $r>r_{c}$. Now, in the models with
+non-constant $\chi_{m}$, the tori become more magnetized than the Komissarov
+solution in the region where $\partial\chi_{m}/\partial r<0$, and less
+magnetized when $\partial\chi_{m}/\partial r>0$. Nevertheless, it is worth
+mentioning that in all solutions presented in this paper the magnetic pressure
+is greater than the hydrodynamic pressure. These new equilibrium tori can be
+useful for studying the accretion of a magnetic media onto a rotating black
+hole.",1808.07400v1
+2018-11-21,"Exploring interfacial exchange coupling and sublattice effect in heavy metal/ferrimagnetic insulator heterostructures using Hall measurements, x-ray magnetic circular dichroism, and neutron reflectometry","We use temperature-dependent Hall measurements to identify contributions of
+spin Hall, magnetic proximity, and sublattice effects to the anomalous Hall
+signal in heavy metal/ferrimagnetic insulator heterostructures with
+perpendicular magnetic anisotropy. This approach enables detection of both the
+magnetic proximity effect onset temperature and the magnetization compensation
+temperature and provides essential information regarding the interfacial
+exchange coupling. Onset of a magnetic proximity effect yields a local extremum
+in the temperature-dependent anomalous Hall signal, which occurs at higher
+temperature as magnetic insulator thickness increases. This magnetic proximity
+effect onset occurs at much higher temperature in Pt than W. The magnetization
+compensation point is identified by a sharp anomalous Hall sign change and
+divergent coercive field. We directly probe the magnetic proximity effect using
+x-ray magnetic circular dichroism and polarized neutron reflectometry, which
+reveal an antiferromagnetic coupling between W and the magnetic insulator.
+Finally, we summarize the exchange-coupling configurations and the anomalous
+Hall-effect sign of the magnetized heavy metal in various heavy metal/magnetic
+insulator heterostructures.",1811.08574v2
+2019-01-07,Unconventional magnetization textures and domain-wall pinning in Sm-Co magnets,"The most powerful magnets for high temperature applications are Sm-Co-based
+alloys with a microstructure that combines magnetically soft and hard regions.
+The microstructure consists of a dense domain-wall-pinning network that endows
+the material with remarkable magnetic hardness. A precise understanding of the
+coupling between magnetism and microstructure is essential for enhancing the
+performance of Sm-Co magnets, but experiments and theory have not yet converged
+to a unified model. Here, we combine transmission electron microscopy, atom
+probe tomography, and nanometer-resolution off-axis electron holography with
+micromagnetic simulations to show that the magnetization processes in Sm-Co
+magnets result from an interplay between curling instabilities and pinning
+effects at the intersections between magnetically soft and hard regions. We
+also find that topologically non-trivial magnetic domains separated by a
+complex network of domain walls play a key role in the magnetic state. Our
+findings reveal a previously hidden aspect of magnetism and provide insight
+into the full potential of high-performance magnetic materials.",1901.01922v3
+2019-02-25,"The effects of surface fossil magnetic fields on massive star evolution: I. Magnetic field evolution, mass-loss quenching and magnetic braking","Surface magnetic fields have a strong impact on stellar mass loss and
+rotation and, as a consequence, on the evolution of massive stars. In this work
+we study the influence of an evolving dipolar surface fossil magnetic field
+with an initial field strength of 4 kG on the characteristics of 15 M$_{\odot}$
+solar metallicity models using the Geneva stellar evolution code. Non-rotating
+and rotating models considering two different scenarios for internal angular
+momentum transport are computed, including magnetic field evolution, mass-loss
+quenching, and magnetic braking. Magnetic field evolution results in weakening
+the initially strong magnetic field, however, in our models an observable
+magnetic field is still maintained as the star evolves towards the red
+supergiant phase. At the given initial mass of the models, mass-loss quenching
+is modest. Magnetic braking greatly enhances chemical element mixing if radial
+differential rotation is allowed for, on the other hand, the inclusion of
+surface magnetic fields yields a lower surface enrichment in the case of near
+solid-body rotation. Models including surface magnetic fields show notably
+different trends on the Hunter diagram (plotting nitrogen abundance vs $v \sin
+i$) compared to those that do not. The magnetic models agree qualitatively with
+the anomalous `Group 2 stars', showing slow surface rotation and high surface
+nitrogen enhancement on the main sequence.",1902.09333v1
+2019-09-29,Experimental identification of electric dipoles induced by magnetic monopoles in Tb2Ti2O7,"The fundamental principles of electrodynamics allow an electron carrying both
+electric monopole (charge) and magnetic dipole (spin) but prohibit its magnetic
+counterpart. Recently it was predicted that the magnetic ""monopoles"" carrying
+emergent magnetic charges in spin ice systems can induce electric dipoles. The
+inspiring prediction offers a novel way to study magnetic monopole excitations
+and magnetoelectric coupling. However, no clear example has been identified up
+to now. Here, we report the experimental evidence for electric dipoles induced
+by magnetic monopoles in spin frustrated Tb2Ti2O7. The magnetic field applied
+to pyrochlore Tb2Ti2O7 along [111] direction, brings out a ""3-in-1-out""
+magnetic monopole configuration, and then induces a subtle structural phase
+transition at Hc~2.3 T. The transition is evidenced by the non-linear phonon
+splitting under magnetic fields and the anomalous crystal-field excitations of
+Tb3+ ions. The observations consistently point to the displacement of the
+oxygen O"" anions along [111] axis which gives rise to the formation of electric
+dipoles. The finding demonstrates that the scenario of magnetic monopole having
+both magnetic charge and electric dipole is realized in Tb2Ti2O7 and sheds
+light into the coupling between electricity and magnetism of magnetic monopoles
+in spin frustrated systems.",1909.13199v1
+2019-11-14,Suspensions of magnetic nanogels at zero field: equilibrium structural properties,"Magnetic nanogels represent a cutting edge of magnetic soft matter research
+due to their numerous potential applications. Here, using Langevin dynamics
+simulations, we analyse the influence of magnetic nanogel concentration and
+embedded magnetic particle interactions on the self-assembly of magnetic
+nanogels at zero field. For this, we calculated radial distribution functions
+and structure factors for nanogels and magnetic particles within them. We found
+that, in comparison to suspensions of free magnetic nanoparticles, where the
+self-assembly is already observed if the interparticle interaction strength
+exceeds the thermal fluctuations by approximately a factor of three,
+self-assembly of magnetic nanogels only takes place by increasing such ratio
+above six. This magnetic nanogel self-assembly is realised by means of
+favourable close contacts between magnetic nanoparticles from different
+nanogels. It turns out that for high values of interparticle interactions,
+corresponding to the formation of internal rings in isolated nanogels, in their
+suspensions larger magnetic particle clusters with lower elastic penalty can be
+formed by involving different nanogels. Finally, we show that when the
+self-assembly of these nanogels takes place, it has a drastic effect on the
+structural properties even if the volume fraction of magnetic nanoparticles is
+low.",1911.06031v1
+2020-02-13,"A new family of disorder-free Rare-Earth-based kagomé lattice magnets: structure and magnetic characterizations of RE3BWO9 (RE=Pr, Nd, Gd-Ho) Boratotungstates","Exploration of rare-earth (RE)-based Kagome lattice magnets with spin-orbital
+entangled jeff=1/2 moments will provide new platform for investigating the
+exotic magnetic phases. Here, we report a new family of RE3BWO9
+(RE=Pr,Nd,Gd-Ho) boratotungstates with magnetic RE3+ ions arranged on Kagome
+lattice, and perform its structure and magnetic characterizations. This serial
+compounds crystallize in hexagonal coordinated structure with space group P63
+(No.173), where magnetic RE3+ ions have distorted Kagom\'e lattice connections
+within the ab plane and stacked in a AB-type fashion along c axis. The
+interlayer RE-RE separation is comparable with that of intralayer distance,
+forming 3-dimensional (3D) exchange coupled magnetic framework of RE3+ ions.
+The magnetic susceptibility data of RE3BWO9 (RE=Pr, Nd, Gd-Ho) reveal dominant
+antiferromagnetic interactions between magnetic RE3+ ions, but without visible
+magnetic ordering down to 2 K. The magnetization analyses for different RE3+
+ions show diverse anisotropic behaviors, make RE3BWO9 as an appealing
+Kagome-lattice antiferromagnet to explore exotic magnetic phases.",2002.05420v1
+2020-05-19,Numerical Analysis of the Screening Current-Induced Magnetic Field in the HTS Insert Dipole Magnet Feather-M2.1-2,"Screening currents are field-induced dynamic phenomena which occur in
+superconducting materials, leading to persistent magnetization. Such currents
+are of importance in ReBCO tapes, where the large size of the superconducting
+filaments gives rise to strong magnetization phenomena. In consequence,
+superconducting accelerator magnets based on ReBCO tapes might experience a
+relevant degradation of the magnetic field quality in the magnet aperture,
+eventually leading to particle beam instabilities. Thus, persistent
+magnetization phenomena need to be accurately evaluated. In this paper, the 2D
+finite element model of the Feather-M2.1-2 magnet is presented. The model is
+used to analyze the influence of the screening current-induced magnetic field
+on the field quality in the magnet aperture. The model relies on a coupled
+field formulation for eddy current problems in time-domain. The formulation is
+introduced and verified against theoretical references. Then, the numerical
+model of the Feather-M2.1-2 magnet is detailed, highlighting the key
+assumptions and simplifications. The numerical results are discussed and
+validated with available magnetic measurements. A satisfactory agreement is
+found, showing the capability of the numerical tool in providing accurate
+analysis of the dynamic behavior of the Feather-M2.1-2 magnet.",2005.09467v2
+2020-07-14,"Inverse energy transfer in decaying, three dimensional, nonhelical magnetic turbulence due to magnetic reconnection","It has been recently shown numerically that there exists an inverse transfer
+of magnetic energy in decaying, nonhelical, magnetically dominated,
+magnetohydrodynamic turbulence in 3-dimensions (3D). We suggest that magnetic
+reconnection is the underlying physical mechanism responsible for this inverse
+transfer. In the two-dimensional (2D) case, the inverse transfer is easily
+inferred to be due to smaller magnetic islands merging to form larger ones via
+reconnection. We find that the scaling behaviour is similar between the 2D and
+the 3D cases, i.e., the magnetic energy evolves as $t^{-1}$, and the magnetic
+power spectrum follows a slope of $k^{-2}$. We show that on normalizing time by
+the magnetic reconnection timescale, the evolution curves of the magnetic field
+in systems with different Lundquist numbers collapse onto one another.
+Furthermore, transfer function plots show signatures of magnetic reconnection
+driving the inverse transfer. We also discuss the conserved quantities in the
+system and show that the behaviour of these quantities is similar between the
+2D and 3D simulations, thus making the case that the dynamics in 3D could be
+approximately explained by what we understand in 2D. Lastly, we also conduct
+simulations where the magnetic field is subdominant to the flow. Here, too, we
+find an inverse transfer of magnetic energy in 3D. In these simulations, the
+magnetic energy evolves as $ t^{-1.4}$ and, interestingly, a dynamo effect is
+observed.",2007.07325v1
+2020-10-17,Creation and confirmation of Hopfions in magnetic multilayer systems,"Topological solitons have been studied for decades in classical field
+theories, and have started recently to impact condensed matter physics. Among
+those solitons, magnetic skyrmions are two-dimensional particle-like objects
+with a continuous winding of the magnetization, and magnetic Hopfions are
+three-dimensional topological solitons that can be formed from a closed loop of
+a twisted skyrmion string. Whereas intense research is underway with magnetic
+skyrmions towards a fundamental understanding and potential applications in
+advanced storage and logic devices, the experimental creation and confirmation
+of magnetic Hopfions has been elusive so far. Theoretical models suggest that
+Hopfions can be stabilized in frustrated or chiral magnetic systems, and that
+target skymions can be transformed into Hopfions by adapting their
+perpendicular magnetic anisotropy. Here, we present experimental evidence of
+magnetic Hopfions that were created in magnetic Ir/Co/Pt multilayers shaped
+into nanoscale disks, which are known to host target skyrmions. The
+three-dimensional spin texture, which distinguishes magnetic Hopfions from
+target skyrmions was confirmed by combining two advanced element-specific
+magnetic X-ray microscopy techniques with about 20-30nm lateral resolution,
+using X-ray magnetic circular dichroism effect as magnetic contrast mechanism
+in surface-sensitive X-ray photoemission electron microscopy and bulk-sensitive
+soft x-ray transmission microscopy. We anticipate that these results will
+stimulate further investigations of Hopfions with different topologies and
+their potential application in three-dimensional spintronics devices.",2010.08674v1
+2020-10-22,Chiral channel network from magnetization textures in 2D MnBi2Te4,"When atomically thin van der Waals (vdW) magnet forms long-period moir\'e
+pattern with a magnetic substrate, the sensitive dependence of interlayer
+magnetic coupling on the atomic registries can lead to moir\'e defined
+magnetization textures in the two-dimensional (2D) magnets. The recent
+discovery of 2D magnetic topological insulators such as MnBi2Te4 leads to the
+interesting possibility to explore the interplay of such magnetization textures
+with the topological surface states, which we explore here with a minimal model
+established for 2D MnBi2Te4. The sign flip of the exchange gap across a
+magnetization domain wall gives rise to a single in-gap chiral channel on each
+surface. In the periodic magnetization textures, such chiral spin channels at
+the domain walls couple to form a network and superlattice minibands emerge. We
+find that in magnetization textures with closed domain wall geometries, the
+formed superlattice miniband is a gapped Dirac cone featuring orbital
+magnetization from the current circulation in the close loops of chiral
+channels, while in magnetization textures with open domain wall geometries,
+gapless mini-Dirac cone is found instead. The miniband Bloch states feature a
+spatial texture of spin and local current density, which are clear
+manifestation of the spin-momentum locked chiral channels at the domain walls.
+The results suggest a new platform to engineer spin and current flows through
+the manipulation of magnetization domains for spintronic devices.",2010.11424v1
+2020-11-23,Unraveling the origin of magnetic fields in galaxies,"Despite their ubiquity, there are many open questions regarding galactic and
+cosmic magnetic fields. Specifically, current observational constraints cannot
+rule out if magnetic fields observed in galaxies were generated in the Early
+Universe or are of astrophysical nature. Motivated by this we use our magnetic
+tracers algorithm to investigate whether the signatures of primordial magnetic
+fields persist in galaxies throughout cosmic time. We simulate a Milky Way-like
+galaxy in four scenarios: magnetised solely by primordial magnetic fields,
+magnetised exclusively by SN-injected magnetic fields, and two combined
+primordial + SN magnetisation cases. We find that once primordial magnetic
+fields with a comoving strength $B_0 >10^{-12}$ G are considered, they remain
+the primary source of galaxy magnetisation. Our magnetic tracers show that,
+even combined with galactic sources of magnetisation, when primordial magnetic
+fields are strong, they source the large-scale fields in the warm metal-poor
+phase of the simulated galaxy. In this case, the circumgalactic and
+intergalactic medium can be used to probe $B_0$ without risk of pollution by
+magnetic fields originated in the galaxy. Furthermore, whether magnetic fields
+are primordial or astrophysically-sourced can be inferred by studying local gas
+metallicity. As a result, we predict that future state-of-the-art observational
+facilities of magnetic fields in galaxies will have the potential to unravel
+astrophysical and primordial magnetic components of our Universe.",2011.11648v2
+2021-02-06,Negative Turbulent Magnetic Diffusivity $β$ effect in a Magnetically Forced System,"We have studied the large scale dynamo process forced with helical magnetic
+energy. The magnetically driven dynamo is not so well studied as kinetically
+forced dynamo. It has been thought to represent the amplification of magnetic
+field in the stellar corona, accretion disk, or plasma lab. However, the
+interaction between the helical magnetic field and plasma is a more fundamental
+phenomenon that can be extended to the early Universe. The scale-invariant
+helical magnetic field not only explains the currently observed large scale
+astrophysical magnetic fields but also has information on the horizon scale in
+the early Universe.
+  The interaction between magnetic field and plasma is inherently non-linear,
+making its mechanism difficult to understand. But, if the plasma system is
+driven with helical field, the process can be linearized with alpha&betaand
+large scale magnetic field. Conventionally, alpha effect is thought to transfer
+magnetic field to the large scale regime, and betaeffect diffuses magnetic
+field. However, these conclusions are based on the incompletely derived
+alpha&beta. To get the exact profiles of evolving alpha&\b{eta}, we solved a
+coupled semi-analytic equation set and applied the result to simulation data
+for the large scale magnetic helicity and magnetic energy.
+  Our result shows that the averaged alpha effect decreases before making a
+significant contribution to the amplification of large scale B field. Rather,
+betaeffect, which keeps negative, de facto plays a key role in the
+amplification of large scale B field with Laplacian. And, this negative
+diffusivity accounts for the attenuation of plasma kinetic energy",2102.03500v4
+2021-05-02,Tunable Néel-Bloch magnetic twists in Fe3GeTe2 with van der Waals structure,"The advent of ferromagnetism in two-dimensional (2D) van der Waals (vdW)
+magnets has stimulated high interest in exploring topological magnetic
+textures, such as skyrmions for use in future skyrmion-based spintronic
+devices. To engineer skyrmions in vdW magnets by transforming Bloch-type
+magnetic bubbles into N\'eel-type skyrmions, the heterostructure of heavy
+metal/vdW magnetic thin film has been made to induce interfacial
+Dzyaloshinskii-Moriya interaction (DMI). However, the unambiguous
+identification of the magnetic textures inherent to vdW magnets, e.g., whether
+the magnetic twists (skyrmions/domain walls) are N\'eel- or Bloch-type, is
+unclear. Here we demonstrate that the N\'eel- or Bloch-type magnetic twists can
+be tuned in the vdW magnet Fe3GeTe2 (FGT) with/without interfacial DMI. We use
+an in-plane magnetic field to align the modulation wavevector q of the
+magnetizations in order to distinguish the N\'eel- or Bloch-type magnetic
+twists. We observe that q is perpendicular to the in-plane field in the
+heterostructure (Pt/oxidized-FGT/FGT/oxidized-FGT), while q aligns at a rotated
+angle with respect to the field direction in the thin plate by thinning bulk
+FGT. We find that the aligned domain wall twists hold fan-like modulations,
+coinciding qualitatively with our computational results.",2105.00468v1
+2021-05-10,Parameterization of magnetic vector potentials and fields for efficient multislice calculations of elastic electron scattering,"The multislice method, which simulates the propagation of the incident
+electron wavefunction through a crystal, is a well-established method for
+analyzing the multiple scattering effects that an electron beam may undergo.
+The inclusion of magnetic effects into this method proves crucial towards
+simulating magnetic differential phase contrast images at atomic resolution,
+enhanced magnetic interaction of vortex beams with magnetic materials,
+calculating magnetic Bragg spots, or searching for magnon signatures, to name a
+few examples. Inclusion of magnetism poses novel challenges to the efficiency
+of the multislice method for larger systems, especially regarding the
+consistent computation of magnetic vector potentials and magnetic fields over
+large supercells. We present in this work a tabulation of parameterized
+magnetic values for the first three rows of transition metal elements computed
+from atomic density functional theory calculations, allowing for the efficient
+computation of approximate magnetic vector fields across large crystals using
+only structural and magnetic moment size and direction information.
+Ferromagnetic bcc Fe and tetragonal FePt are chosen as examples in this work to
+showcase the performance of the parameterization versus directly obtaining
+magnetic vector fields from the unit cell spin density by density functional
+theory calculations, both for the quantities themselves and the resulting
+magnetic signal from their respective use in multislice calculations.",2105.04195v1
+2022-01-03,Exchange Bias and Interface-related Effects in Two-dimensional van der Waals Magnetic Heterostructures: Open Questions and Perspectives,"The exchange bias (EB) effect is known as a fundamentally and technologically
+important magnetic property of a magnetic bilayer film. It is manifested as a
+horizontal shift in a magnetic hysteresis loop of a film subject to cooling in
+the presence of a magnetic field. The EB effect in van der Waals (vdW)
+heterostructures offers a novel approach for tuning the magnetic properties of
+the newly discovered single-layer magnets, as well as adds a new impetus to
+magnetic vdW heterostructures. Indeed, intriguing EB effects have recently been
+reported in a variety of low-dimensional vdW magnetic systems ranging from a
+weakly interlayer-coupled vdW magnet (e.g., Fe3GeTe2) to a bilayer composed of
+two different magnetic vdW materials (e.g., Fe3GeTe2/CrCl3, Fe3GeTe2/FePS3,
+Fe3GeTe2/MnPS3), to bilayers of two different vdW defective magnets (e.g.,
+VSe2/MoS2), or to metallic ferromagnet/vdW defective magnet interfaces (e.g.,
+Fe/MoS2). Despite their huge potential in spintronic device applications, the
+physical origins of the observed EB effects have remained elusive to
+researchers. We present here a critical review of the EB effect and associated
+phenomena such as magnetic proximity (MP) in various vdW heterostructure
+systems and propose approaches to addressing some of the emerging fundamental
+questions.",2201.00479v1
+2022-02-15,The effect of inter-particle hydrodynamic and magnetic interactions in a magnetorheological fluid,"A magnetorheological fluid, which consists of magnetic particles suspended in
+a viscous fluid, flows freely with well-dispersed particles in a the absence of
+a magnetic field, but particle aggregation results in flow cessation when a
+field is applied. The mechanism of dynamical arrest is examined by analysing
+interactions between magnetic particles in a magnetic field subject to a shear
+flow. An isolated spherical magnetic particle undergoes a transition between a
+rotating state at low magnetic field and a static orientation at high magnetic
+field. The effect of interactions for spherical dipolar and polarisable
+particles with static orientation is examined for a dilute viscous suspension.
+There are magnetic interactions due to the magnetic field disturbance at one
+particle caused by the dipole moment of another, hydrodynamic interactions due
+to the antisymmetric force moment of a non-rotating particle in a shear flow,
+and a modification of the magnetic field due to the particle magnetic moment
+density. When there is a concentration variation, the torque balance condition
+results in a disturbance to the orientation of the particle magnetic moment.
+The net force and the drift velocity due to these disturbances is calculated,
+and the collective motion generated is equivalent to an anisotropic diffusion
+process. When the magnetic field is in the flow plane, the diffusion
+coefficients in the two directions perpendicular to the field direction are
+negative, implying that concentration fluctuations are unstable in these
+directions. This instability could initiate field-induced dynamical arrest in a
+magnetorheological fluid.",2202.07488v1
+2022-06-24,Quark anomalous magnetic moment leads to the inverse magnetic catalysis phenomena of chiral restoration and deconfinement phase transitions in $μ_B-T$ plane,"The effect of quark anomalous magnetic moment (AMM) to chiral restoration and
+deconfinement phase transitions in baryon chemical potential-temperature
+$(\mu_B-T)$ plane under magnetic fields is investigated in frame of a
+Pauli-Villars regularized PNJL model. It's found that the quark AMM plays the
+role of inverse catalysis to the phase transitions, and large quark AMM will
+change the magnetic catalysis phenomena of phase transitions to inverse
+magnetic catalysis in the whole $\mu_B-T$ plane. For a fixed magnetic field,
+the critical temperature $T_c$ and critical baryon chemical potential $\mu_B^c$
+decreases with quark AMM. The stronger the magnetic field is, the inverse
+catalysis effect of AMM becomes more important. For a small AMM
+$\kappa=\kappa_1$, it shows the magnetic catalysis effect for critical
+temperature $T_c$ at vanishing $\mu_B$ with increasing magnetic field, and
+(inverse) magnetic catalysis effect for critical baryon chemical potential
+$\mu_B^c$ at vanishing $T$ under (weak) strong magnetic field. At finite $T$
+and $\mu_B$, there exist some crossings of the phase transition lines with
+different magnetic field. For a large AMM $\kappa=\kappa_2$, we obtain the
+inverse magnetic catalysis effect in the whole $\mu_B-T$ plane, and no
+crossings of phase transition lines happen.",2206.12054v1
+2022-07-14,UI$_3$ -- 5f-electron magnetic van der Waals material,"We grew high-quality single crystals of the 5f electron van der Waals
+compound UI$_3$ and investigated them by measurements of specific heat and
+magnetization as functions of temperature and magnetic field. UI$_3$ behaves as
+an antiferromagnet with a first-order magnetic phase transition at the Ne\'el
+temperature $T_N$ = 2.65 K. It is characterized by a sharp symmetric
+specific-heat peak which is gradually shifted to lower temperatures by
+increasing magnetic field applied along either the a- or b-axis. The behavior
+in magnetic fields reveals orthorhombic magnetocrystalline anisotropy with the
+hard magnetization direction along the c-axis. The 2-K a- and b-axis
+magnetization curves exhibit a metamagnetic transition at the critical field
+$H_c$ = 3 T and 1.8 T, respectively. In higher fields, when the long-range
+antiferromagnetism is suppressed by a metamagnetic transition, signs of
+short-range magnetic ordering of antiferromagnetic correlations in the
+paramagnetic state show up both in specific heat and magnetization. The
+anomalous S-shape field dependence of a-axis magnetization well above $H_c$ can
+be understood as the crossover from the correlated paramagnetic regime to the
+high-field polarized paramagnet. The magnetic phase diagrams for the magnetic
+field applied along the a- and b-axis, respectively, designed using the
+mentioned experimental results are presented. We have also found that the
+UI$_3$ crystals are easily cleavable which predisposes this material for direct
+investigation of 5f electron magnetism in the 2D limit on exfoliated atomically
+thin samples.",2207.06880v1
+2022-07-27,Effective and asymptotic criticality of structurally disordered magnets,"Changes in magnetic critical behaviour of quenched structurally-disordered
+magnets are usually exemplified in experiments and in MC simulations by diluted
+systems consisting of magnetic and non-magnetic components. By our study we aim
+to show, that similar effects can be observed not only for diluted magnets with
+non-magnetic impurities, but may be implemented, e.g., by presence of two (and
+more) chemically different magnetic components as well. To this end, we
+consider a model of the structurally-disordered quenched magnet where all
+lattice sites are occupied by Ising-like spins of different length $L$. In such
+random spin length Ising model the length $L$ of each spin is a random variable
+governed by the distribution function $p(L)$. We show that this model belongs
+to the universality class of the site-diluted Ising model. This proves that
+both models are described by the same values of asymptotic critical exponents.
+However, their effective critical behaviour differs. As a case study we
+consider a quenched mixture of two different magnets, with values of elementary
+magnetic moments $L_1=1$ and $L_2=s$, and of concentration $c$ and $1-c$,
+correspondingly. We apply field-theoretical renormalization group approach to
+analyze the renormalization group flow for different initial conditions,
+triggered by $s$ and $c$, and to calculate effective critical exponents further
+away from the fixed points of the renormalization group transformation. We show
+how the effective exponents are governed by difference in properties of the
+magnetic components.",2207.13655v1
+2023-04-13,Chirality-Induced Magnetization of Magnetite by an RNA Precursor,"Life is homochiral and homochirality is a fundamental feature of living
+systems on Earth. While the exact mechanism that led to homochirality is still
+not fully understood, any realistic scenario on the origins of life needs to
+address the emergence of homochirality. In order to impose and maintain
+chirality in a prebiotic network, an environmental factor functioning as a
+chiral agent is demanded. Magnetized surfaces are prebiotically plausible
+chiral agents, shown to be effective in enantioseparation of
+ribose-aminooxazoline (RAO), a ribonucleic acid (RNA) precursor, due to the
+chiral-induced spin selectivity (CISS) effect. As such, mechanisms for breaking
+the magnetic symmetry of magnetic minerals are of the utmost importance. Here
+we report the avalanche magnetization of magnetite $(Fe_{3}O_{4})$ by the
+crystallization of enantiopure RAO. The observed breaking of the magnetic
+symmetry is induced by the chiral molecules due to the CISS effect and spreads
+out across the magnetic surface like an avalanche, providing a way to uniformly
+magnetize a magnetic surface without fully covering it. Considered together
+with our previous results on enantioseparation by crystallization on a magnetic
+surface, chirality-induced avalanche magnetization paves the way for a
+cooperative feedback between chiral molecules and magnetic surfaces. With this
+feedback, a weak natural bias in the net magnetization can be amplified and
+spin-selective processes can be accommodated on magnetic minerals on a
+persistent basis.",2304.09095v1
+2023-06-13,Imaging magnetism evolution of magnetite to megabar pressure range with quantum sensors in diamond anvil cell,"High-pressure diamond anvil cells have been widely used to create novel
+states of matter. Nevertheless, the lack of universal in-situ magnetic
+measurement techniques at megabar pressures makes it difficult to understand
+the underlying physics of materials' behavior at extreme conditions, such as
+high-temperature superconductivity of hydrides and the formation or destruction
+of the local magnetic moments in magnetic systems, etc. Here we break through
+the limitations of pressure on quantum sensors and develop the in-situ magnetic
+detection technique at megabar pressures with high sensitivity
+(~1{\mu}T/Hz^(1\2)) and sub-microscale spatial resolution. By directly imaging
+the magnetic field and the evolution of magnetic domains, we observe the
+macroscopic magnetic transition of Fe3O4 in the megabar pressure range from
+strong ferromagnetism ({\alpha}-Fe3O4) to weak ferromagnetism ({\beta}-Fe3O4)
+and finally to non-magnetism ({\gamma}-Fe3O4). The scenarios for magnetic
+changes in Fe3O4 characterized here shed light on the direct magnetic
+microstructure observation in bulk materials at high pressure and contribute to
+understanding the mechanism of magnetic moment suppression related to spin
+crossover. The presented method can potentially investigate the spin-orbital
+coupling and magnetism-superconductivity competition in magnetic systems.",2306.07840v1
+2023-09-19,Field Orientation Dependent Magnetic Phases In Weyl Semimetal Co3Sn2S2,"Magnetism plays a key role in the emergence of topological phenomena in the
+Weyl semimetal Co3Sn2S2, which exhibits a ferromagnetic (FM) interactions along
+the c-axis of the crystal and an antiferromagnetic (AFM) interactions within
+the ab plane. Extensive studies on the temperature dependence of the magnetism
+with the magnetic field along the c-axis have uncovered a number of magnetic
+phases. Currently, the nature and origins of the reported magnetic phases are
+under debate. Here we report on magnetic field orientation effects on the
+magnetism in Co3Sn2S2. The shape of the hysteresis loop of the Hall resistance
+at a fixed temperature is found to change from rectangular to bow-tie-like as
+the magnetic field is tilted from the c-axis towards the ab plane, resembling
+that reported for magnetic fields along the c-axis as the temperature
+approaches the Curie temperature from below. Unlike their temperature-dependent
+counterparts, the newly observed bow-tie-like hysteresis loops show exchange
+bias. Our results showcase the contribution of the in-plane AFM interactions to
+the magnetism in Co3Sn2S2 and demonstrate a new way to tune its magnetic
+phases. They also shed light on the temperature-dependent magnetic phases
+occurring in the magnetic field along the c-axis of the crystal.",2309.10221v1
+2023-11-16,Meridional Circulations of the Solar Magnetic Fields of Different Strength,"The meridional circulation of the solar magnetic fields in Solar Cycles 21-24
+was considered. Data from both ground-based and space observatories were used.
+Three types of time-latitude distributions of photospheric magnetic fields and
+their meridional circulations were identified depending on the magnetic field
+intensity. (i) low-strength magnetic fields. They were distributed evenly
+across latitude and weakly depended on the magnetic fields of active regions
+and their cycle variation; (ii) medium-strength magnetic fields. For these
+fields a wave-like, pole-to-pole, antiphase meridional circulation with a
+period of approximately 22 years was revealed. The velocities of meridional
+flows were slower at the minima of solar activity, when they were at high
+latitudes in the opposite hemispheres, and maximal at the solar maxima, when
+the positive- and negative-polarity waves crossed the equator. The meridional
+circulation of these fields reflects the solar global magnetic field dynamics
+and determines the solar polar field reversal; (iii) high-strength (active
+region) magnetic fields. They were distributed symmetrically in the Northern
+and Southern hemispheres. Magnetic fields of both leading and following sunspot
+polarity migrated from high to low latitudes. The meridional-flow velocities of
+high-strength magnetic fields were higher at the rising and maxima phases than
+at the minima. Some of the high-latitude active region magnetic fields were
+captured by the second type meridional circulation flows and transported along
+with them to the appropriate pole. But the magnetic fields of active regions
+are not the main ones in the solar polar field reversal. The results indicate
+that high-strength magnetic fields were not the main source of weak ones.",2311.09900v1
+2024-02-03,Drivers of Magnetic Field Amplification at Oblique Shocks: In-Situ Observations,"Collisionless shocks are ubiquitous structures throughout the universe. Shock
+waves in space and astrophysical plasmas convert the energy of a fast-flowing
+plasma to other forms of energy, including thermal and magnetic energies.
+Plasma turbulence and high-amplitude electric and magnetic fluctuations are
+necessary for effective energy conversion and particle acceleration. We survey
+and characterize in-situ observations of reflected ions and magnetic field
+amplification rates at quasi-perpendicular shocks under a wide range of
+upstream conditions. We report magnetic amplification factors as high as 25
+times the upstream magnetic field in our current dataset. Reflected ions
+interacting with the incoming plasma create magnetic perturbations which cause
+magnetic amplification in upstream and downstream regions of
+quasi-perpendicular shocks. Our observations show that in general magnetic
+amplification increases with the fraction of reflected ions, which itself
+increases with Mach number. Both parameters plateau once full reflection is
+reached. Magnetic amplification continuously increases with the inverse of the
+magnetization parameter of the upstream plasma. We find that the extended foot
+region upstream of shocks and nonlinear processes within that region are key
+factors for intense magnetic amplification. Our observations at
+non-relativistic shocks provide the first experimental evidence that below a
+certain magnetization threshold, the magnetic amplification efficiency at
+quasi-perpendicular shocks becomes comparable to that at the quasi-parallel
+shocks.",2402.02014v1
+2024-02-15,Understanding and tuning magnetism in layered Ising-type antiferromagnet FePSe3 for potential 2D magnet,"Recent development in two-dimensional (2D) magnetic materials have motivated
+the search for new van der Waals magnetic materials, especially Ising-type
+magnets with strong magnetic anisotropy. Fe-based MPX3 (M = transition metal, X
+= chalcogen) compounds such as FePS3 and FePSe3 both exhibit an Ising-type
+magnetic order, but FePSe3 receives much less attention compared to FePS3. This
+work focuses on establishing the strategy to engineer magnetic anisotropy and
+exchange interactions in this less-explored compound. Through chalcogen and
+metal substitutions, the magnetic anisotropy is found to be immune against S
+substitution for Se whereas tunable only with heavy Mn substitution for Fe. In
+particular, Mn substitution leads to a continuous rotation of magnetic moments
+from the out-of-plane direction towards in-plane. Furthermore, the magnetic
+ordering temperature displays non-monotonic doping dependence for both
+chalcogen and metal substitutions but due to different mechanisms. These
+findings provide deeper insight into the Ising-type magnetism in this important
+van der Waals material, shedding light on the study of other Ising-type
+magnetic systems as well as discovering novel 2D magnets for potential
+applications in spintronics.",2402.10155v1
+2024-03-24,Strongly asymmetric magnetization switching and programmable complete Boolean logic enabled by long-range intralayer Dzyaloshinskii-Moriya interaction,"Electrical switching of magnetization is central to spintronics. Despite the
+enormous efforts on the spin torques and the Dzyaloshinskii-Moriya interaction
+(DMI) effects, some fundamental physics for electrical switching of
+magnetization is still missing as indicated by a number of remarkable
+long-standing puzzles. Here, we report the discovery of the long-range
+intralayer DMI effect widely existing in magnetic heterostructure, which is
+distinct from the yet-known DMI effects as it describes the chiral coupling of
+two orthogonal magnetic domains within the same magnetic layer via the
+mediation of an adjacent heavy metal layer. The long-range intralayer DMI
+generates a strong perpendicular effective magnetic field (H_DMI^z) on the
+perpendicular magnetization. Characteristically, H_DMI^z varies with the
+sign/magnitude of the interfacial DMI constant, the applied in-plane magnetic
+fields, and the distribution of the perpendicular magnetic anisotropy. The
+long-range intralayer DMI results in striking consequences including the
+strongly asymmetric current/field switching of perpendicular magnetization,
+hysteresis loop shift of perpendicular magnetization in the absence of in-plane
+direct current, and sharp, complete switching of perpendicular magnetization
+purely by an in-plane magnetic field. Utilizing the long-range intralayer DMI
+effect, we demonstrate programable, complete Boolean logic operations (i.e.,
+AND, NAND, NOT, OR, and NOR) within a single spin-orbit torque device. These
+results will stimulate the investigation of the long-range intralayer DMI
+effect and its impacts on a variety of spintronic devices.",2403.16035v1
+2012-02-24,Magnetic field amplification in electron phase-space holes and related effects,"Three-dimensional electron phase space holes are shown to be positive charges
+on the plasma background which produce a radial electric field and force the
+trapped electron component into an azimuthal drift. In this way electron holes
+generate magnetic fields in the hole. We solve the cylindrical hole model
+exactly for the hole charge, electric potential and magnetic field. In electron
+holes, the magnetic field is amplified on the flux tube of the hole;
+equivalently, in ion holes the field would be decreased. The flux tube adjacent
+to the electron hole is magnetically depleted by the external hole dipole
+field. This causes magnetic filamentation. It is also shown that holes are
+massive objects, each carrying a finite magnetic moment. Binary magnetic dipole
+interaction of these moments will cause alignment of the holes into chains
+along the magnetic field or, in the three-dimensional case, produce a magnetic
+fabric in the volume of hole formation. Since holes, in addition to being
+carriers of charges and magnetic moments, also have finite masses, they behave
+like quasi-particles, performing ExB, magnetic field, and diamagnetic drifts.
+In an inhomogeneous magnetic field, their magnetic moments experience torque
+which causes nutation of the hole around the direction of the magnetic field
+presumably giving rise to low frequency magnetic modulations like pulsations. A
+gas of many such holes may allow for a kinetic description in which holes
+undergo binary dipole interactions. This resembles the polymeric behaviour.
+Both magnetic field generation and magnetic structure formation is of interest
+in auroral, solar coronal and shock physics, in particular in the problem of
+magnetic field filamentation in relativistic foreshocks and cosmic ray
+acceleration.",1202.5428v1
+1998-06-09,PG 0946+301: the Rosetta Stone of BALQSOs?,"We describe the motivation and features of a multiwavelength spectroscopic
+campaign on broad absorption line (BAL) QSO PG~0946+301. The main goal of this
+project is to determine the ionization equilibrium and abundances (IEA) in BAL
+outflows. Previous studies of IEA in BALQSOs were based on the assumption that
+the BALs are not saturated so that the column densities inferred from the
+apparent optical depths are realistic. This critical assumption is at odds with
+several recent observations and with analysis of existing data which indicate
+that the absorption troughs are heavily saturated even when they are not black.
+In addition, X-ray observations, which are important for constraining the
+ionizing continuum, were not available for those objects that had UV spectral
+data. Quantifying the level of saturation in the BALs necessitates UV
+spectroscopy with much higher S/N and broader spectral coverage than currently
+exist. After taking into account the capabilities of available observatories,
+our best hope for a substantial improvement in understanding the IEA in BALQSOs
+is to concentrate considerable observational resources on the most promising
+object. Our studies of available HST and ground-based spectra show that
+PG~0946+301 is by far the best candidate for such a program. This BALQSO is at
+least five times brighter, shortward of 1000 A rest frame, than any other
+object, and due to its low redshift it has an especially sparse Lya forest. At
+the same time PG~0946+301 is a typical BALQSO and therefore its IEA should be
+representative. To this effect we are developing a multiwavelength
+spectroscopic campaign (UV, FUV, X-ray and optical) on BALQSO PG 0946+301. We
+discuss the goals and feasibility of each observational component: HST, FUSE,
+ASCA and ground-based.",9806131v1
+2003-02-26,Multiwavelength studies of the Seyfert 1 galaxy NGC7469. I - Far UV observations with FUSE,"We obtained far-ultraviolet spectra of the Seyfert 1 galaxy NGC 7469 using
+the FUSE on 1999 December 6. Our spectra cover the wavelength range 990-1187 A
+with a resolution of 0.05 A. We see broad emission lines of CIII, NIII, OVI,
+and HeII as well as intrinsic absorption lines in the OVI 1032,1038 resonance
+doublet. The absorption arises in two distinct kinematic components at systemic
+velocities of -569 km/s and -1898 km/s. Both components are very highly
+ionized- no significant Ly beta absorption is present. The higher blueshift
+component is not quite saturated, and it has a total OVI column density of
+8e14/cm2. It covers more than 90% of the continuum and broad-line emission. The
+lower blue shift component is heavily saturated and covers only 50% of the
+continuum and broad-line emission. It too has a column density of 8e14/cm2, but
+this is less certain due to the high saturation. We set an upper limit of
+<1.5e18/cm2 on the OVI column density of this component. Its line depth is
+consistent with coverage of only the continuum, and thus this component may lie
+interior to the broad emission-line gas. The component at -569 km/s has a
+velocity comparable to the high-ionization X-ray absorption lines seen in the
+XMM-Newton grating spectrum of NGC 7469, and photoionization models show that
+the observed column densities of OVI and HI are compatible with their formation
+in the same gas as that causing the X-ray absorption. The gas at -1898 km/s has
+lower ionization and column density, and no significant X-ray absorption is
+associated with it.",0302552v1
+2005-03-03,How To Distinguish Neutron Star and Black Hole X-ray Binaries? Spectral index and Quasi-Periodic Oscillation Frequency Correlation,"Recent studies have revealed strong correlations between 1-10 Hz frequencies
+of quasiperiodic oscillations (QPOs) and the spectral power law index of
+several Black Hole (BH) candidate sources when seen in the low/hard state, the
+steep power-law (soft) state, and in transition between these states. In the
+soft state these index-QPO frequency correlations show a saturation of the
+photon index about 2.7 at high values of the low frequency. This saturation
+effect was previously identified as a black hole signature. In this paper we
+argue that this saturation does not occur, at least for one neutron star (NS)
+source 4U 1728-34, for which the index monotonically increases with the low
+frequency to the values of 6 and higher. We base this conclusion on our
+analysis about 1.5 Msec of RXTE archival data for 4U 1728-34. We reveal the
+spectral evolution of the Comptonized blackbody spectra when the source
+transitions from the hard to soft states. The hard state spectrum is a typical
+thermal Comptonization spectrum of the soft photons which originate in the disk
+and the NS outer photospheric layers. The hard state photon index is about 2.
+The soft state spectrum consists of two blackbody components which are only
+slightly Comptonized. Thus we can claim (as expected from theory) that in NS
+sources thermal equilibrium is established for the soft state. To the contrary
+in BH sources, the equilibrium is never established due to the presence of the
+BH horizon. The emergent BH spectrum, even in the high/soft state, has a power
+law component. We also show that the presence of Fe K_alpha emission-line
+strengths, QPOs, and the link between them does not depend on radio flux in 4U
+1728-34.",0503081v1
+2006-10-04,Correction of SOHO CELIAS/SEM EUV Measurements saturated by extreme solar flare events,"The solar irradiance in the Extreme Ultraviolet (EUV) spectral bands has been
+observed with a 15 sec cadence by the SOHO Solar EUV Monitor (SEM) since 1995.
+During remarkably intense solar flares the SEM EUV measurements are saturated
+in the central (zero) order channel (0.1 -- 50.0 nm) by the flare soft X-ray
+and EUV flux. The first order EUV channel (26 -- 34 nm) is not saturated by the
+flare flux because of its limited bandwidth, but it is sensitive to the arrival
+of Solar Energetic Particles (SEP). While both channels detect nearly equal SEP
+fluxes, their contributions to the count rate is sensibly negligible in the
+zero order channel but must be accounted for and removed from the first channel
+count rate. SEP contribution to the measured SEM signals usually follows the
+EUV peak for the gradual solar flare events. Correcting the extreme solar flare
+SEM EUV measurements may reveal currently unclear relations between the flare
+magnitude, dynamics observed in different EUV spectral bands, and the measured
+Earth atmosphere response. A simple and effective correction technique based on
+analysis of SEM count-rate profiles, GOES X-ray, and GOES proton data has been
+developed and used for correcting EUV measurements for the five extreme solar
+flare events of July 14, 2000, October 28, November 2, November 4, 2003, and
+January 20, 2005. Although none of the 2000 and 2003 flare peaks were
+contaminated by the presence of SEPs, the January 20, 2005 SEPs were unusually
+prompt and contaminated the peak. The estimated accuracy of the correction is
+about 7.5% for large X-class events.",0610123v1
+2007-01-31,Entropy of entanglement and correlations induced by a quench: Dynamics of a quantum phase transition in the quantum Ising model,"Quantum Ising model in one dimension is an exactly solvable example of a
+quantum phase transition. We investigate its behavior during a quench from a
+paramagnetic to ferromagnetic phase caused by a gradual turning off of the
+transverse field at a fixed rate characterized by the quench time $\tau_Q$. In
+agreement with Kibble-Zurek mechanism, quantum state of the system after the
+transition exhibits a characteristic correlation length $\hat\xi$ proportional
+to the square root of the quench time $\tau_Q$. The inverse of this correlation
+length determines average density of defects after the transition. In this
+paper, we show that $\hat\xi$ also controls the entropy of entanglement of a
+block of $L$ spins with the rest of the system. For large $L$, this entropy
+saturates at $\frac16\log_2\hat\xi$, as might have been expected from the
+Kibble-Zurek mechanism. Close to the critical point, the entropy saturates when
+the block size $L\approx\hat\xi$, but -- in the subsequent evolution in the
+ferromagnetic phase -- a somewhat larger length scale
+$l=\sqrt{\tau_Q}\ln\tau_Q$ develops as a result of quantum dephasing, and the
+entropy saturates when $L\approx l$. We also study the spin-spin correlation.
+We find that close to the critical point ferromagnetic correlations decay
+exponentially with the dynamical correlation length $\hat\xi$, but in the
+following evolution this correlation function becomes oscillatory at distances
+less than this scale. However, both the wavelength and the correlation length
+of these oscillations are still determined by $\hat\xi$. We also derive
+probability distribution for the number of kinks in a finite spin chain after
+the transition.",0701768v2
+2005-01-26,Inherently Global Nature of Topological Charge Fluctuations in QCD,"We have recently presented evidence that in configurations dominating the
+regularized pure-glue QCD path integral, the topological charge density
+constructed from overlap Dirac operator organizes into an ordered space-time
+structure. It was pointed out that, among other properties, this structure
+exhibits two important features: it is low-dimensional and geometrically
+global, i.e. consisting of connected sign-coherent regions with local
+dimensions 1<= d < 4, and spreading over arbitrarily large space--time
+distances. Here we show that the space-time structure that is responsible for
+the origin of topological susceptibility indeed exhibits global behavior. In
+particular, we show numerically that topological fluctuations are not saturated
+by localized concentrations of most intense topological charge density. To the
+contrary, the susceptibility saturates only after the space-time regions with
+most intense fields are included, such that geometrically global structure is
+already formed. We demonstrate this result both at the fundamental level (full
+topological density) and at low energy (effective density). The drastic
+mismatch between the point of fluctuation saturation (~ 50% of space-time at
+low energy) and that of global structure formation (<4% of space-time at low
+energy) indicates that the ordered space-time structure in topological charge
+is inherently global and that topological charge fluctuations in QCD cannot be
+understood in terms of individual localized pieces. Description in terms of
+global brane-like objects should be sought instead.",0501025v3
+2003-12-16,Chiral approach to nuclear matter: Role of explicit short-range NN-terms,"We extend a recent chiral approach to nuclear matter by including the most
+general (momentum-independent) NN-contact interaction. Iterating this
+two-parameter contact-vertex with itself and with one-pion exchange the
+emerging energy per particle exhausts all terms possible up-to-and-including
+fourth order in the small momentum expansion. The equation of state of pure
+neutron matter, $\bar E_n(k_n)$, can be reproduced very well up to quite high
+neutron densities of $\rho_n=0.5\fmd$ by adjusting the strength of a repulsive
+$nn$-contact interaction. Binding and saturation of isospin-symmetric nuclear
+matter is a generic feature of our perturbative calculation. Fixing the maximum
+binding energy per particle to $-\bar E(k_{f0})= 15.3 $MeV we find that any
+possible equilibrium density $\rho_0$ lies below $\rho_0^{\rm max}=0.191\fmd$.
+The additional constraint from the neutron matter equation of state leads
+however to a somewhat too low saturation density of $\rho_0 =0.134 \fmd$. We
+also investigate the effects of the NN-contact interaction on the complex
+single-particle potential $U(p,k_f)+i W(p,k_f)$. We find that the effective
+nucleon mass at the Fermi-surface is bounded from below by $M^*(k_{f0}) \geq
+1.4 M$. This property keeps the critical temperature of the liquid-gas phase
+transition at somewhat too high values $T_c \geq 21 $MeV. The downward bending
+of the asymmetry energy $A(k_f)$ above nuclear matter saturation density is a
+generic feature of the approximation to fourth order. Altogether, there is
+within this complete fourth-order calculation no ""magic"" set of adjustable
+short-range parameters with which one could reproduce simultaneously and
+accurately all semi-empirical properties of nuclear matter.",0312057v1
+2005-04-08,Hadron Production and Phase Changes in Relativistic Heavy Ion Collisions,"We study soft hadron production in relativistic heavy ion collisions in a
+wide range of reaction energy, 4.8 GeV <sqrt{s_ NN}<200 GeV, and make
+predictions about yields of particles using the statistical hadronization
+model. In fits to experimental data, we obtain both statistical parameters as
+well as physical properties of the hadron source. We identify the properties of
+the fireball at the critical energy threshold, 6.26 GeV < sqrt{s_NN}^cr} <7.61
+GeV, delineating for higher energies hadronization of an entropy rich phase. In
+terms of the chemical composition, one sees a phase which at low energy is
+chemically under-saturated, and which turns into a chemically over-saturated
+state persisting up to the maximum accessible energy. Assuming that there is no
+change in physical mechanisms in the energy range 15>sqrt{s_NN} \ge 200 GeV, we
+use continuity of particle yields and statistical parameters to predict the
+hadron production at sqrt{s_NN}=62.4 GeV, and obtain total yields of hadrons at
+sqrt{s_NN}=130 GeV. We consider, in depth, the pattern we uncover within the
+hadronization condition, and discuss possible mechanisms associated with the
+identified rapid change in system properties at sqrt{s_NN ^cr}. We propose that
+the chemically over-saturated 2+1 flavor hadron matter system undergoes a 1st
+order phase transition.",0504028v5
+2007-11-22,Constraining the Symmetry Energy: A Journey in the Isospin Physics from Coulomb Barrier to Deconfinement,"Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium
+nuclear interaction in regions away from saturation. In this work we present a
+selection of reaction observables in dissipative collisions particularly
+sensitive to the isovector part of the interaction, i.e. to the symmetry term
+of the nuclear Equation of State (EoS). At low energies the behavior of the
+symmetry energy around saturation influences dissipation and fragment
+production mechanisms. We will first discuss the recently observed Dynamical
+Dipole Radiation, due to a collective neutron-proton oscillation during the
+charge equilibration in fusion and deep-inelastic collisions. Important Iso-EOS
+effects are stressed. Reactions induced by unstable 132Sn beams appear to be
+very promising tools to test the sub-saturation Isovector EoS. New Isospin
+sensitive observables are also presented for deep-inelastic, fragmentation
+collisions and Isospin equilibration measurements (Imbalance Ratios). The high
+density symmetry term can be derived from isospin effects on heavy ion
+reactions at relativistic energies (few AGeV range), that can even allow a
+``direct'' study of the covariant structure of the isovector interaction in the
+hadron medium. Rather sensitive observables are proposed from collective flows
+and from pion/kaon production. The possibility of the transition to a mixed
+hadron-quark phase, at high baryon and isospin density, is finally suggested.
+Some signatures could come from an expected ``neutron trapping'' effect. The
+importance of studying violent collisions with radioactive beams from low to
+relativistic energies is finally stressed.",0711.3546v1
+2008-02-04,Coronal Structure and Abundances in Young Fast Rotators,"AB Dor, Speedy Mic and Rst137B are in their early post-T Tauri evolutionary
+phase (<100Myr), at the age of fastest rotation in the life of late-type stars.
+They straddle the coronal saturation-supersaturation boundary first defined by
+young stars in open clusters. High resolution Chandra X-ray spectra have been
+analysed to study their coronal properties as a function of coronal activity
+parameters Rossby number, $L_X/L_{bol}$ and a coronal temperature index. Plasma
+emission measure distributions as a function of temperature show broad peaks at
+T~10e7K. Differences between stars suggest that as supersaturation is reached
+the DEM slope below the temperature of peak DEM becomes shallower, while the
+DEM drop-off above this temperature becomes more pronounced. A larger sample
+comprising our three targets and 22 active stars studied in the recent
+literature reveals a general increase of plasma at T>10e7 toward the
+saturated-supersaturated boundary but a decline beyond this among
+supersaturated stars. All three of the stars studied in detail here show lower
+coronal abundances of the low FIP elements Mg, Si and Fe, relative to the high
+FIP elements S, O and Ne, as compared to the solar mixture. The coronal Fe
+abundances of the stellar sample are inversely correlated with Lx/Lbol,
+declining slowly with rising Lx/Lbol, but with a much more sharp decline at
+Lx/Lbol>3x10e-4. For dwarfs the Fe abundance is also well-correlated with
+Rossby number. The coronal O/Fe ratios for dwarfs show a clear increase with
+decreasing Rossby number, apparently reaching saturation at [O/Fe]=0.5 at the
+coronal supersaturation boundary. Similar increases in O/Fe with increasing
+coronal temperature and $L_X/L_{bol}$ are seen.",0802.0326v1
+2008-02-06,CO Isotopologues in the Perseus Molecular Cloud Complex: the X-Factor and Regional Variations,"We use the COMPLETE data to derive new calibrations of the X-factor and the
+13CO abundance within Perseus. We divide Perseus into six sub-regions. The
+standard X factor, X=N(H2)/W(12CO), is derived both for the whole Perseus
+Complex and for each of the six sub-regions with values consistent with
+previous estimates. The X factor is heavily affected by the saturation of the
+emission above AV~4 mag, and variations are found between regions. We derive
+linear fits to relate W(12CO) and AV using only points below 4 mag of
+extinction, this yields a better estimation of the AV than the X-factor. We
+derive linear relations of W(13CO), N(13CO) and W(C18O) with AV . The
+extinction threshold above which 13CO(1-0) and C18O(1-0) are detected is about
+1 mag larger than previous estimates. 12CO(1-0) and 13CO(1-0) lines saturate
+above 4 and 5 mag, respectively, whereas C18O(1-0) never saturates (up to 10
+mag). Approximately 60% of the positions with 12CO emission have sub-thermally
+excited lines, and almost all positions have 12CO excitation temperatures below
+the dust temperature. Using the Meudon PDR code we find that 12CO and 13CO
+emission can be explained by uniform slab models with densities ranging between
+about 10^3 and 10^4 cm-3. Local variations in the volume density and
+non-thermal motions (linked to different star formation activity) can explain
+the observations. Higher densities are needed to reproduce CO data toward
+active star forming sites, where the larger internal motions driven by the
+young protostars allow more photons from the embedded high density cores to
+escape the cloud. In the most quiescent region, the 12CO and 13CO emission
+appears to arise from an almost uniform thin layer of molecular material at
+densities around 10^4 cm-3.",0802.0708v1
+2008-11-21,Characterising the Gravitational Instability in Cooling Accretion Discs,"We perform numerical analyses of the structure induced by gravitational
+instabilities in cooling gaseous accretion discs. For low enough cooling rates
+a quasi-steady configuration is reached, with the instability saturating at a
+finite amplitude in a marginally stable disc. We find that the saturation
+amplitude scales with the inverse square root of the cooling parameter beta =
+t_cool / t_dyn, which indicates that the heating rate induced by the
+instability is proportional to the energy density of the induced density waves.
+We find that at saturation the energy dissipated per dynamical time by weak
+shocks due is of the order of 20 per cent of the wave energy. From Fourier
+analysis of the disc structure we find that while the azimuthal wavenumber is
+roughly constant with radius, the mean radial wavenumber increases with radius,
+with the dominant mode corresponding to the locally most unstable wavelength.
+We demonstrate that the density waves excited in relatively low mass discs are
+always close to co-rotation, deviating from it by approximately 10 per cent.
+This can be understood in terms of the flow Doppler-shifted phase Mach number
+-- the pattern speed self-adjusts so that the flow into spiral arms is always
+sonic. This has profound effects on the degree to which transport through
+self-gravity can be modelled as a viscous process. Our results thus provide (a)
+a detailed description of how the self-regulation mechanism is established for
+low cooling rates, (b) a clarification of the conditions required for
+describing the transport induced by self-gravity through an effective
+viscosity, (c) an estimate of the maximum amplitude of the density perturbation
+before fragmentation occurs, and (d) a simple recipe to estimate the density
+perturbation in different thermal regimes.",0811.3629v1
+2010-06-21,Keck ESI Observations of Metal-Poor Damped Lyman-α Systems,"We present the first results from a survey of SDSS quasars selected for
+strong H I damped Lyman-{\alpha} (DLA) absorption with corresponding low
+equivalent width absorption from strong low-ion transitions (e.g. C II
+{\lambda}1334 and Si II {\lambda}1260). These metal-poor DLA candidates were
+selected from the SDSS DR5 quasar spectroscopic database, and comprise a large
+new sample for probing low metallicity galaxies. Medium-resolution echellette
+spectra from the Keck ESI spectrograph for an initial sample of 35 systems were
+obtained to explore the metal-poor tail of the DLA distribution and to
+investigate the nucleosynthetic patterns at these metallicities. We have
+estimated saturation corrections for the moderately under-resolved spectra, and
+systems with very narrow Doppler parameter (b \le 5 km s-1) will likely have
+underestimated abundances. For those systems with Doppler parameters b > 5 km
+s-1, we have measured low metallicity DLA gas with [X/H] < -2.4 for at least
+one of C, O, Si, or Fe. Assuming non-saturated components, we estimate that
+several DLA systems have [X/H] < -2.8, including five DLA systems with both low
+equivalent widths and low metallicity in transitions of both C II and O I. All
+of the measured DLA metallicities, however, exceed or are consistent with a
+metallicity of at least 1/1000 of solar, regardless of the effects of
+saturation in our spectra. Our results indicate that the metal-poor tail of
+galaxies at z \sim 3 drops exponentially at [X/H]< -3. The observed ratio of
+[C/O] for values of [O/H] < -2.5 exceeds values seen in moderate metallicity
+DLA systems, and also exceeds theoretical nucleosynthesis predictions for
+higher mass Population III stars.",1006.4119v1